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106 total matches.
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McMaster University
1.
Tupper, Andrew.
Computational Modeling of RNA Replication in an RNA World.
Degree: PhD, 2020, McMaster University
URL: http://hdl.handle.net/11375/25836 
► The biology of modern life predicts the existence of an ancient RNA world. A phase of evolution in which organisms utilized RNA as a genetic…
(more)
▼ The biology of modern life predicts the existence of an ancient RNA world. A phase of evolution in which organisms utilized RNA as a genetic material and a catalyst. However, the existence of an RNA organism necessitates RNA’s ability to self-replicate, which has yet to be proven. In this thesis, we utilize computational modeling to address some of the problems facing RNA replication. In chapter 2, we consider a polymerase ribozyme replicating by the Qβ bacteriophage mechanism. When bound to a surface, limited diffusion allows for survival so long as the termination error rate is below an error threshold. In Chapter 3, we consider the replication of short oligomers through an abiotic mechanism proposed in prebiotic experiments. When limited by substrate availability, competition results in the emergence of uniform RNA polymers from a messy prebiotic soup containing nucleotides of different chirality and sugars. In chapter 4, we consider the possibility of an RNA world lacking cytosine. Without cytosine, the ability of RNA to fold to complex secondary structures is limited. Furthermore, G-U wobble base pairing hinders the transfer of information during replication. Nevertheless, we conclude that an RNA world lacking cytosine may be possible, but more difficult for the initial emergence of life. In chapter 5, we analyze abiotic and viral mechanisms of RNA replication using known kinetic and thermodynamic data. While most mechanisms fail under non-enzymatic conditions, rolling-circle replication appears possible. In chapter 6, we extend our analysis of the rolling-circle mechanism to consider the fidelity of replication. Due to the thermodynamic penalty of incorporating an error, rolling-circle replication appears to undergo error correction. This results in highly accurate replication and circumvents Eigen’s paradox. Rolling-circle replication therefore presents an appealing option for the emergence of RNA replication in an RNA world.
Thesis
Doctor of Philosophy (PhD)
Advisors/Committee Members: Higgs, Paul, Biochemistry.
Subjects/Keywords: RNA World; Origin of life
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APA (6th Edition):
Tupper, A. (2020). Computational Modeling of RNA Replication in an RNA World. (Doctoral Dissertation). McMaster University. Retrieved from http://hdl.handle.net/11375/25836
Chicago Manual of Style (16th Edition):
Tupper, Andrew. “Computational Modeling of RNA Replication in an RNA World.” 2020. Doctoral Dissertation, McMaster University. Accessed January 26, 2021.
http://hdl.handle.net/11375/25836.
MLA Handbook (7th Edition):
Tupper, Andrew. “Computational Modeling of RNA Replication in an RNA World.” 2020. Web. 26 Jan 2021.
Vancouver:
Tupper A. Computational Modeling of RNA Replication in an RNA World. [Internet] [Doctoral dissertation]. McMaster University; 2020. [cited 2021 Jan 26].
Available from: http://hdl.handle.net/11375/25836.
Council of Science Editors:
Tupper A. Computational Modeling of RNA Replication in an RNA World. [Doctoral Dissertation]. McMaster University; 2020. Available from: http://hdl.handle.net/11375/25836
University of Sydney
2.
Ben-Barak, Idan.
States of origin: influences on research into the origins of life
.
Degree: 2012, University of Sydney
URL: http://hdl.handle.net/2123/12227
► The twentieth century has seen a continuous process of redefinition of scientific understanding of the process by which life appeared on planet earth, and the…
(more)
▼ The twentieth century has seen a continuous process of redefinition of scientific understanding of the process by which life appeared on planet earth, and the emergence of a trans-disciplinary scientific field concerned with the question of the origin of life. The thesis explores the scientific, historical and conceptual issues relevant to this research field, and provides a novel analysis of the interrelated development of theories and experiments within it. The thesis will argue for a discovery-driven and technology-driven view of research into the origins of life, rather than a primarily hypothesis-driven endeavour. The thesis will also explore the influence exerted on research into the origin of life by its prime financial backer - the United States government’s National Aeronautics and Space Administration (NASA). Lastly, the theory will present research into the origin of life as an indicator of more general trends in the natural and life sciences.
Subjects/Keywords: Origin of life;
NASA
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APA (6th Edition):
Ben-Barak, I. (2012). States of origin: influences on research into the origins of life
. (Thesis). University of Sydney. Retrieved from http://hdl.handle.net/2123/12227
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Ben-Barak, Idan. “States of origin: influences on research into the origins of life
.” 2012. Thesis, University of Sydney. Accessed January 26, 2021.
http://hdl.handle.net/2123/12227.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Ben-Barak, Idan. “States of origin: influences on research into the origins of life
.” 2012. Web. 26 Jan 2021.
Vancouver:
Ben-Barak I. States of origin: influences on research into the origins of life
. [Internet] [Thesis]. University of Sydney; 2012. [cited 2021 Jan 26].
Available from: http://hdl.handle.net/2123/12227.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Ben-Barak I. States of origin: influences on research into the origins of life
. [Thesis]. University of Sydney; 2012. Available from: http://hdl.handle.net/2123/12227
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of California – Berkeley
3.
Mangiante, David Michael.
Metal and mineral catalyzed organic photochemistry in modern and prebiotic environments.
Degree: Earth & Planetary Science, 2016, University of California – Berkeley
URL: http://www.escholarship.org/uc/item/6jq7m95b
► Minerals and metals serve important roles in the organic geochemistry of natural environments. Mobility of organics, catalysis of degradation, and redox catalysis are among the…
(more)
▼ Minerals and metals serve important roles in the organic geochemistry of natural environments. Mobility of organics, catalysis of degradation, and redox catalysis are among the processes affected by minerals. With the addition of ultraviolet light a new suite of photo-induced redox reactions is possible including reductive and oxidative ligand-to-metal/mineral charge transfer. Such reactions allow for novel chemistry that has relevance to the modern Earth as well as the pre-biotic origin of life. This thesis describes processes by which electrons transfer between minerals/metals and organic ligands relevant to natural systems as well as the origins of life. I present evidence of ultrafast electron transfer and the production of radical intermediates essential to deducing redox reaction mechanisms. I also present methods for communicating understanding of interfacial chemistry to the public that promote engagement in science. This thesis is broadly applicable to those interested in mineral organic photochemistry, electron transfer, the origin of life, and science teaching methods.I probed the chemistry between organic molecules and minerals/metals, using pump/probe transient absorption (TA) spectroscopy to observe the dynamics of electrons and vibrational modes at timescales ranging from picoseconds to nanoseconds. This technique can be conducted in solution and can be highly sensitive to intermediate reaction products. I examined the photolysis of the metal carboloto, ferric oxalate, under UV irradiation using mid-infrared TA spectroscopy in both D2O and H2O. Ferric oxalate is a model molecule for natural systems and is used to measure photo flux due to its well-characterized quantum efficiency. However, the mechanism of its photolysis is debated. This was the first time the intermediates of ferric oxalate photolysis were observed using techniques sensitive to the vibrational states of organic molecules. I observed the rapid intramolecular charge transfer and the production of CO2 and tentatively CO2•–. Additionally, we observed intermediate states that we interpret to be CO2 disassociating from ferrous iron, a signature never before reported. Investigations of photo-induced electron transfer were expanded to ZnS nanoparticles and fumarate. Fumarate is an intermediate metabolite in the tricarboxilic acid (TCA) cycle, which is a part of core metabolism in modern organisms. It undergoes a two-electron reduction to form succinate. Reductive versions of the TCA cycle may have been important for the origin of prebiotic metabolism. I measured the effect of adsorbed fumarate on the electronic states of photo-excited ZnS and observed electron transfer both at short (<1 ps) and long (>1 ns) timescales. Additionally, I observed an electronic signature tentatively attributed to fumarate radical, which persisted for at least 8 nanoseconds. The appearance of a long-lived radical intermediate product and the rapid initial electron transfer from the mineral to the organic suggests that ZnS could be a viable catalyst for prebiotic…
Subjects/Keywords: Geochemistry; Origin of life; Photochemistry; Transient Spectroscopy
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APA (6th Edition):
Mangiante, D. M. (2016). Metal and mineral catalyzed organic photochemistry in modern and prebiotic environments. (Thesis). University of California – Berkeley. Retrieved from http://www.escholarship.org/uc/item/6jq7m95b
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Mangiante, David Michael. “Metal and mineral catalyzed organic photochemistry in modern and prebiotic environments.” 2016. Thesis, University of California – Berkeley. Accessed January 26, 2021.
http://www.escholarship.org/uc/item/6jq7m95b.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Mangiante, David Michael. “Metal and mineral catalyzed organic photochemistry in modern and prebiotic environments.” 2016. Web. 26 Jan 2021.
Vancouver:
Mangiante DM. Metal and mineral catalyzed organic photochemistry in modern and prebiotic environments. [Internet] [Thesis]. University of California – Berkeley; 2016. [cited 2021 Jan 26].
Available from: http://www.escholarship.org/uc/item/6jq7m95b.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Mangiante DM. Metal and mineral catalyzed organic photochemistry in modern and prebiotic environments. [Thesis]. University of California – Berkeley; 2016. Available from: http://www.escholarship.org/uc/item/6jq7m95b
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Bristol
4.
Avila Castro, Alberto.
Peptide Morse code : α/β-peptide β-sheets for information storage and transmission.
Degree: PhD, 2020, University of Bristol
URL: http://hdl.handle.net/1983/59019909-b6b2-4cc9-bef0-01223d3b9cfc
► The origin of life remains a most relevant scientific problem. It is clear that present-day life results from Darwinian evolution. However, in a prebiotic Earth,…
(more)
▼ The origin of life remains a most relevant scientific problem. It is clear that present-day life results from Darwinian evolution. However, in a prebiotic Earth, species (presumably molecules) capable of “informational self-replication” were necessary for evolution to be triggered. In this context, we propose a system based on α/β-peptide hybrid β-sheets. In these molecules, information can be encoded in the sequence of α- and β-amino acids. Aggregation into β-sheets should occur sequence-selectively and the aggregate can then act as a template for peptide self-replication. The use of long/short components to store and transfer information suggests the term “peptide Morse code” (PMC) for the system. To prove this concept, we took two approaches: First, to study the sequence-selectivity of β-sheet formation, we used a series of short decamer α/β-peptide hybrids containing a β-turn segment. It was shown through NMR and CD analyses that molecules with matching α/β-residues in their β-strands would fold into stable β-hairpins in organic media, due to the formation of an intramolecular β-sheet, whereas, there was structural evidence for the absence of such stable intramolecular β-sheets in molecules bearing strands with mismatching α/β-residues. Secondly, to evaluate sequence-selective self-replication in α/β-peptide hybrids, we built a water-soluble amphiphilic PMC variant of a literature replicator and an alternative hydrophobic system. Unfortunately, autocatalysis has remained elusive in both peptide systems. Alternatively, evidence for the intramolecular templation of new covalent bonds arising from α/β-sequence recognition in the strands of a β-hairpin was obtained. This work has provided the first evidence for both, the α/β-sequence-selective assembly of β-sheet structures and the template-directed formation of covalent bonds by these structures.
Subjects/Keywords: Origin of life; peptide secondary structure
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APA ·
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APA (6th Edition):
Avila Castro, A. (2020). Peptide Morse code : α/β-peptide β-sheets for information storage and transmission. (Doctoral Dissertation). University of Bristol. Retrieved from http://hdl.handle.net/1983/59019909-b6b2-4cc9-bef0-01223d3b9cfc
Chicago Manual of Style (16th Edition):
Avila Castro, Alberto. “Peptide Morse code : α/β-peptide β-sheets for information storage and transmission.” 2020. Doctoral Dissertation, University of Bristol. Accessed January 26, 2021.
http://hdl.handle.net/1983/59019909-b6b2-4cc9-bef0-01223d3b9cfc.
MLA Handbook (7th Edition):
Avila Castro, Alberto. “Peptide Morse code : α/β-peptide β-sheets for information storage and transmission.” 2020. Web. 26 Jan 2021.
Vancouver:
Avila Castro A. Peptide Morse code : α/β-peptide β-sheets for information storage and transmission. [Internet] [Doctoral dissertation]. University of Bristol; 2020. [cited 2021 Jan 26].
Available from: http://hdl.handle.net/1983/59019909-b6b2-4cc9-bef0-01223d3b9cfc.
Council of Science Editors:
Avila Castro A. Peptide Morse code : α/β-peptide β-sheets for information storage and transmission. [Doctoral Dissertation]. University of Bristol; 2020. Available from: http://hdl.handle.net/1983/59019909-b6b2-4cc9-bef0-01223d3b9cfc
University of Oxford
5.
Zhang, Yulin.
Substrate recognition by holocytochrome C synthase in cytochrome C biogenesis system III.
Degree: PhD, 2015, University of Oxford
URL: http://ora.ox.ac.uk/objects/uuid:47533f13-92c5-4349-8b70-02e659a00112
;
https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.711874
► C-type cytochromes are ubiquitous proteins with crucial functions in organisms, which include electron transfer and apoptotic signalling. In eukaryotic organisms, mitochondrial cytochrome c is located…
(more)
▼ C-type cytochromes are ubiquitous proteins with crucial functions in organisms, which include electron transfer and apoptotic signalling. In eukaryotic organisms, mitochondrial cytochrome c is located in the intermembrane space, and it is a component of the electron transport chain; it is responsible for transferring electrons from Complex III to Complex IV. The regulated release of cytochrome c from mitochondria results in the activation of a signal transduction pathway leading to controlled cell death, or apoptosis. In mitochondrial c-type cytochromes, the heme is bound to both cysteines of a CXXCH motif located near the N-terminus. The covalent heme attachment in c-type cytochromes, the final step in its biosynthesis, is achieved by different cytochrome c biogenesis systems in different organisms. Out of these systems, System III, found in many eukaryotes, has a single component - holocytochrome c synthase (HCCS) which is the enzyme responsible for the catalysis of heme binding to cytochrome c. HCCS recognises apocytochrome c as a substrate upon the import of the apocytochrome from the cytosolic space to the mitochondrial intermembrane space. The requirements of amino acid sequence for HCCS recognition had remained an intriguing question, despite the relatively long period since the discovery of the enzyme. Thus, HCCS in System III and its substrate recognition is the subject of this thesis. This thesis describes the experiments showing that the N-terminal region of the mitochondrial cytochrome c protein is important for substrate recognition, as well as further characterisation of this sequence by mutagenesis. Out of several highly conserved residues in the N-terminus, a phenylalanine residue in the N-terminus is identified to be critical for heme attachment by HCCS. The role of this phenylalanine residue in the interaction between the two proteins was probed by substituting it with a range of residues. Furthermore, the importance of the spacing between the key phenylalanine residue and the CXXCH motif was investigated. A single-cysteine variant of the mitochondrial cytochrome c with a single bond to the heme is produced by HCCS, but heme attachment only occurs if histidine is present as an axial ligand to the heme iron. Replacement of the histidine with other potential iron-ligating residues abolished heme attachment. These results bring insight into the critical features in amino acid sequence of cytochrome c for the substrate recognition specificity of HCCS. Sequence analysis on the N-terminal region of mitochondrial cytochromes c in a variety of organisms reveals evolutionary implications for cytochrome c biogenesis systems. It also attempts to explain the reason for negative results in previous chapters for the analysis of the N-terminal region of cytochrome c. An improved method for human HCCS production is also described in this thesis, for the exploitation of purification and characterisation in future studies of HCCS.
Subjects/Keywords: 572; Cytochromes; Life – Origin; Charge exchange
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Record Details
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Zhang, Y. (2015). Substrate recognition by holocytochrome C synthase in cytochrome C biogenesis system III. (Doctoral Dissertation). University of Oxford. Retrieved from http://ora.ox.ac.uk/objects/uuid:47533f13-92c5-4349-8b70-02e659a00112 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.711874
Chicago Manual of Style (16th Edition):
Zhang, Yulin. “Substrate recognition by holocytochrome C synthase in cytochrome C biogenesis system III.” 2015. Doctoral Dissertation, University of Oxford. Accessed January 26, 2021.
http://ora.ox.ac.uk/objects/uuid:47533f13-92c5-4349-8b70-02e659a00112 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.711874.
MLA Handbook (7th Edition):
Zhang, Yulin. “Substrate recognition by holocytochrome C synthase in cytochrome C biogenesis system III.” 2015. Web. 26 Jan 2021.
Vancouver:
Zhang Y. Substrate recognition by holocytochrome C synthase in cytochrome C biogenesis system III. [Internet] [Doctoral dissertation]. University of Oxford; 2015. [cited 2021 Jan 26].
Available from: http://ora.ox.ac.uk/objects/uuid:47533f13-92c5-4349-8b70-02e659a00112 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.711874.
Council of Science Editors:
Zhang Y. Substrate recognition by holocytochrome C synthase in cytochrome C biogenesis system III. [Doctoral Dissertation]. University of Oxford; 2015. Available from: http://ora.ox.ac.uk/objects/uuid:47533f13-92c5-4349-8b70-02e659a00112 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.711874
6.
Deuel, Edith E.
Biogenesis and its modern implications.
Degree: 2017, California State University – Sacramento
URL: http://hdl.handle.net/10211.3/194128
Part of a retrospective digitization project.
Advisors/Committee Members: Ludwig, Carl E..Subjects/Keywords: Life – Origin
…x29; mentioned in an article on the
origin of life that Pasteur himself was very cautious… …to formulate more precise hypotheses about the
origin of life on the eart's surface… …idea of life always depending
upon preceding life as an important concept.
You might de… …life emanating only from life was accepted, you may use the
historical development of this… …experiments are verified and applied in everyday life.
If
you could have them prepare some sterile…
Record Details
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Record Details
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APA ·
Chicago ·
MLA ·
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Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Deuel, E. E. (2017). Biogenesis and its modern implications. (Thesis). California State University – Sacramento. Retrieved from http://hdl.handle.net/10211.3/194128
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Deuel, Edith E. “Biogenesis and its modern implications.” 2017. Thesis, California State University – Sacramento. Accessed January 26, 2021.
http://hdl.handle.net/10211.3/194128.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Deuel, Edith E. “Biogenesis and its modern implications.” 2017. Web. 26 Jan 2021.
Vancouver:
Deuel EE. Biogenesis and its modern implications. [Internet] [Thesis]. California State University – Sacramento; 2017. [cited 2021 Jan 26].
Available from: http://hdl.handle.net/10211.3/194128.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Deuel EE. Biogenesis and its modern implications. [Thesis]. California State University – Sacramento; 2017. Available from: http://hdl.handle.net/10211.3/194128
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Bristol
7.
Avila Castro, Alberto.
Peptide Morse code : α/β-peptide β-sheets for information storage and transmission.
Degree: PhD, 2020, University of Bristol
URL: https://research-information.bris.ac.uk/en/studentTheses/59019909-b6b2-4cc9-bef0-01223d3b9cfc
;
https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.809899
► The origin of life remains a most relevant scientific problem. It is clear that present-day life results from Darwinian evolution. However, in a prebiotic Earth,…
(more)
▼ The origin of life remains a most relevant scientific problem. It is clear that present-day life results from Darwinian evolution. However, in a prebiotic Earth, species (presumably molecules) capable of “informational self-replication” were necessary for evolution to be triggered. In this context, we propose a system based on α/β-peptide hybrid β-sheets. In these molecules, information can be encoded in the sequence of α- and β-amino acids. Aggregation into β-sheets should occur sequence-selectively and the aggregate can then act as a template for peptide self-replication. The use of long/short components to store and transfer information suggests the term “peptide Morse code” (PMC) for the system. To prove this concept, we took two approaches: First, to study the sequence-selectivity of β-sheet formation, we used a series of short decamer α/β-peptide hybrids containing a β-turn segment. It was shown through NMR and CD analyses that molecules with matching α/β-residues in their β-strands would fold into stable β-hairpins in organic media, due to the formation of an intramolecular β-sheet, whereas, there was structural evidence for the absence of such stable intramolecular β-sheets in molecules bearing strands with mismatching α/β-residues. Secondly, to evaluate sequence-selective self-replication in α/β-peptide hybrids, we built a water-soluble amphiphilic PMC variant of a literature replicator and an alternative hydrophobic system. Unfortunately, autocatalysis has remained elusive in both peptide systems. Alternatively, evidence for the intramolecular templation of new covalent bonds arising from α/β-sequence recognition in the strands of a β-hairpin was obtained. This work has provided the first evidence for both, the α/β-sequence-selective assembly of β-sheet structures and the template-directed formation of covalent bonds by these structures.
Subjects/Keywords: Origin of life; peptide secondary structure
Record Details
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Record Details
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Avila Castro, A. (2020). Peptide Morse code : α/β-peptide β-sheets for information storage and transmission. (Doctoral Dissertation). University of Bristol. Retrieved from https://research-information.bris.ac.uk/en/studentTheses/59019909-b6b2-4cc9-bef0-01223d3b9cfc ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.809899
Chicago Manual of Style (16th Edition):
Avila Castro, Alberto. “Peptide Morse code : α/β-peptide β-sheets for information storage and transmission.” 2020. Doctoral Dissertation, University of Bristol. Accessed January 26, 2021.
https://research-information.bris.ac.uk/en/studentTheses/59019909-b6b2-4cc9-bef0-01223d3b9cfc ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.809899.
MLA Handbook (7th Edition):
Avila Castro, Alberto. “Peptide Morse code : α/β-peptide β-sheets for information storage and transmission.” 2020. Web. 26 Jan 2021.
Vancouver:
Avila Castro A. Peptide Morse code : α/β-peptide β-sheets for information storage and transmission. [Internet] [Doctoral dissertation]. University of Bristol; 2020. [cited 2021 Jan 26].
Available from: https://research-information.bris.ac.uk/en/studentTheses/59019909-b6b2-4cc9-bef0-01223d3b9cfc ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.809899.
Council of Science Editors:
Avila Castro A. Peptide Morse code : α/β-peptide β-sheets for information storage and transmission. [Doctoral Dissertation]. University of Bristol; 2020. Available from: https://research-information.bris.ac.uk/en/studentTheses/59019909-b6b2-4cc9-bef0-01223d3b9cfc ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.809899
McMaster University
8.
Shah, Vismay.
Comparing Protocell and Surface-Based Models of RNA Replicator Systems and Determining Favourable Conditions for Linkage of Functional Strands.
Degree: MSc, 2019, McMaster University
URL: http://hdl.handle.net/11375/24901
► In hypothesized RNA-World scenarios, replication of RNA strands is catalyzed by error-prone polymerase ribozymes. Incorrect replication leads to the creation of non-functional, parasitic strands which…
(more)
▼ In hypothesized RNA-World scenarios, replication of RNA strands is catalyzed by error-prone polymerase ribozymes. Incorrect replication leads to the creation of non-functional, parasitic strands which can invade systems of replicators and lead to their death. Studies have shown two solutions to this problem: spatial clustering of polymerases in models featuring elements to limit diffusion, and group selection in models featuring protocells. Making a quantitative comparison of the methods using results from the literature has proven difficult due to differences in model design. Here we develop computational models of replication of a system of polymerases, polymerase complements and parasites in both spatial models and protocell models with near identical dynamics to make meaningful comparison viable. We compare the models in terms of the maximum mutation rate survivable by the system (the error threshold) as well as the minimum replication rate constant required. We find that protocell models are capable of sustaining much higher maximum mutation rates, and survive under much lower minimum replication rates than equivalent surface models. We then consider cases where parasites are favoured in replication, and show that the advantage of protocell models is increased. Given that a system of RNA strands undergoing catalytic replication by a polymerase is fairly survivable in protocell models, we attempt to determine whether isolated strands can develop into genomes. We extend our protocell model to include additional functional strands varying in length (and thus replication rate) and allow for the linkage of strands to form proto-chromosomes. We determine that linkage is possible over a broad range of lengths, and is stable when considering the joining of short functional strands to the polymerase (and the same for the complementary sequences). Moreover, linkage of short functional strands to the polymerase assures more cells remain viable post division by ensuing a good quantity of polymerase equivalents are present in the parent cell prior to splitting.
Thesis
Master of Science (MSc)
Collections of RNA polymers are good candidates for the origin of life. RNA is able to store genetic information and act as polymerase ribozymes allowing RNA to replicate RNA. Polymerases have been experimentally developed in labs, however none are sufficiently general to work well in an origins of life setting. These polymerases are vulnerable to mistakes during copying, making survival of RNA systems difficult. Such systems have been studied by computer simulations, showing that the strands need to be kept together for survival, either on surfaces or in primitive cells. Differences in the details of the models has made comparing the surfaces to cells difficult. This work creates a unified model base allowing for comparison of these two environments. We find that the existence of primitive cells is very beneficial to systems of RNA polymers and thus it is likely such cells existed at the origin of life.
Advisors/Committee Members: Higgs, Paul, Physics and Astronomy.
Subjects/Keywords: Origin of Life; RNA World; Protocells; Surface; Computational Models; RNA Polymerase
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APA (6th Edition):
Shah, V. (2019). Comparing Protocell and Surface-Based Models of RNA Replicator Systems and Determining Favourable Conditions for Linkage of Functional Strands. (Masters Thesis). McMaster University. Retrieved from http://hdl.handle.net/11375/24901
Chicago Manual of Style (16th Edition):
Shah, Vismay. “Comparing Protocell and Surface-Based Models of RNA Replicator Systems and Determining Favourable Conditions for Linkage of Functional Strands.” 2019. Masters Thesis, McMaster University. Accessed January 26, 2021.
http://hdl.handle.net/11375/24901.
MLA Handbook (7th Edition):
Shah, Vismay. “Comparing Protocell and Surface-Based Models of RNA Replicator Systems and Determining Favourable Conditions for Linkage of Functional Strands.” 2019. Web. 26 Jan 2021.
Vancouver:
Shah V. Comparing Protocell and Surface-Based Models of RNA Replicator Systems and Determining Favourable Conditions for Linkage of Functional Strands. [Internet] [Masters thesis]. McMaster University; 2019. [cited 2021 Jan 26].
Available from: http://hdl.handle.net/11375/24901.
Council of Science Editors:
Shah V. Comparing Protocell and Surface-Based Models of RNA Replicator Systems and Determining Favourable Conditions for Linkage of Functional Strands. [Masters Thesis]. McMaster University; 2019. Available from: http://hdl.handle.net/11375/24901
Western Washington University
9.
Ernest, Samantha Elizabeth O'Keffe Neff.
Analysis of the role of RNA silencing protein 1 (Rsp1) in the biogenesis of ~23-24 nt sRNAs in Tetrahymena thermophila.
Degree: MS, Biology, 2020, Western Washington University
URL: https://cedar.wwu.edu/wwuet/951
► RNA interference (RNAi) pathways regulate a variety of biological processes, including normal cell growth and development, through the action of protein-RNA complexes containing small…
(more)
▼ RNA interference (RNAi) pathways regulate a variety of biological processes, including normal cell growth and development, through the action of protein-RNA complexes containing small RNAs (sRNAs). Our research focused an RNAi pathway in the ciliated unicellular eukaryote
Tetrahymena thermophila. This pathway produces ~23-24 nucleotide (nt) sRNAs through the action of RNA-dependent RNA polymerase (RdRP) complexes (complexes termed RdRCs) and their interaction with an RNA nuclease called Dicer 2 (Dcr2). The accumulation of sRNAs also requires a protein called RNA Silencing Protein 1 (Rsp1)
which associates with a subset of RdRC proteins. In this study, we first sought to learn more about the potential function and evolutionary conservation of Rsp1 by examining its sequence. Our results indicate Rsp1 may have structural similarity to RNA polymerases, including RdRPs, but lacks the conserved catalytic residues for RNA synthesis. We also identified Rsp1-like predicted proteins in other
Tetrahymena species, but no clear homologs in more distantly related organisms.
Second, we tested three hypotheses for why Rsp1 is required for sRNA accumulation: 1) Rsp1 stabilizes the precursor RNA transcripts that are later processed into sRNA, 2) Rsp1 is necessary for the accumulation of RdRC proteins, and 3) Rsp1 is necessary for correct assembly of RdRCs. Our experimental results indicate that Rsp1 does not appear to regulate sRNA biogenesis by regulating the levels of sRNA precursors or RdRC proteins levels. Instead, purification of RdRCs revealed that in strains lacking Rsp1, RdRCs cannot be recovered. This suggests that RdRCs are disrupted somehow in the absence of Rsp1.
Advisors/Committee Members: Lee, Suzanne R., Pillitteri, Lynn, Singh-Cundy, Anu.
Subjects/Keywords: Biology; Tetrahymena; RNA interference; Life – Origin; masters theses
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APA (6th Edition):
Ernest, S. E. O. N. (2020). Analysis of the role of RNA silencing protein 1 (Rsp1) in the biogenesis of ~23-24 nt sRNAs in Tetrahymena thermophila. (Masters Thesis). Western Washington University. Retrieved from https://cedar.wwu.edu/wwuet/951
Chicago Manual of Style (16th Edition):
Ernest, Samantha Elizabeth O'Keffe Neff. “Analysis of the role of RNA silencing protein 1 (Rsp1) in the biogenesis of ~23-24 nt sRNAs in Tetrahymena thermophila.” 2020. Masters Thesis, Western Washington University. Accessed January 26, 2021.
https://cedar.wwu.edu/wwuet/951.
MLA Handbook (7th Edition):
Ernest, Samantha Elizabeth O'Keffe Neff. “Analysis of the role of RNA silencing protein 1 (Rsp1) in the biogenesis of ~23-24 nt sRNAs in Tetrahymena thermophila.” 2020. Web. 26 Jan 2021.
Vancouver:
Ernest SEON. Analysis of the role of RNA silencing protein 1 (Rsp1) in the biogenesis of ~23-24 nt sRNAs in Tetrahymena thermophila. [Internet] [Masters thesis]. Western Washington University; 2020. [cited 2021 Jan 26].
Available from: https://cedar.wwu.edu/wwuet/951.
Council of Science Editors:
Ernest SEON. Analysis of the role of RNA silencing protein 1 (Rsp1) in the biogenesis of ~23-24 nt sRNAs in Tetrahymena thermophila. [Masters Thesis]. Western Washington University; 2020. Available from: https://cedar.wwu.edu/wwuet/951
University of Cambridge
10.
Attwater, James.
Ice as a medium for RNA-catalysed RNA synthesis and evolution.
Degree: PhD, 2011, University of Cambridge
URL: https://doi.org/10.17863/CAM.15946
;
https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609847
► A critical event in the origin of life is thought to have been the emergence of a molecule capable of self-replication and evolution. According to…
(more)
▼ A critical event in the origin of life is thought to have been the emergence of a molecule capable of self-replication and evolution. According to the RNA World hypothesis, this could have been an RNA polymerase ribozyme capable of generating copies of itself from simple nucleotide precursors. In vitro evolution experiments have provided modern examples of such ribozymes, such as the R18 RNA polymerase ribozyme, exhibiting basic levels of this crucial catalytic activity; R18’s activity, however, falls far short of that required of an RNA replicase, leaving unanswered the question of whether RNA can catalyse its self-replication. This thesis describes the development and use of a novel in vitro selection system, Compartmentalised Bead-Tagging (CBT), to isolate variants of the R18 ribozyme with improved sequence generality and extension capabilities. CBT evolution and engineering of polymerase ribozymes, together with RNA template evolution, allowed the synthesis of RNA molecules over 100 nucleotides long, as well as the RNA-catalysed transcription of a catalytic hammerhead ribozyme. This demonstrates the catalytic capabilities of ribozyme polymerases. The R18 ribozyme was also exploited as an analogue of a primordial replicase, to determine replicase behaviour in different reaction environments. Substantial ribozyme polymerisation occurred at −7˚C in the liquid eutectic phase of water-ice; increased ribozyme stability at these low temperatures allowed longer extension products to be generated than at ambient temperatures. The concentration effect of eutectic phase formation could also yield RNA synthesis from dilute solutions of substrates, and provide quasicellular compartmentalisation of ribozymes. These beneficial physicochemical features of ice make it a potential protocellular medium for the emergence of primordial replicases. Ice also could serve as a medium for CBT, allowing the isolation of a polymerase ribozyme adapted to the low temperatures in the ice phase, demonstrating the primordial potential and modern feasibility of ribozyme evolution in ice.
Subjects/Keywords: 610; RNA; Ribozyme; Origin of Life; RNA world; Ice
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APA (6th Edition):
Attwater, J. (2011). Ice as a medium for RNA-catalysed RNA synthesis and evolution. (Doctoral Dissertation). University of Cambridge. Retrieved from https://doi.org/10.17863/CAM.15946 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609847
Chicago Manual of Style (16th Edition):
Attwater, James. “Ice as a medium for RNA-catalysed RNA synthesis and evolution.” 2011. Doctoral Dissertation, University of Cambridge. Accessed January 26, 2021.
https://doi.org/10.17863/CAM.15946 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609847.
MLA Handbook (7th Edition):
Attwater, James. “Ice as a medium for RNA-catalysed RNA synthesis and evolution.” 2011. Web. 26 Jan 2021.
Vancouver:
Attwater J. Ice as a medium for RNA-catalysed RNA synthesis and evolution. [Internet] [Doctoral dissertation]. University of Cambridge; 2011. [cited 2021 Jan 26].
Available from: https://doi.org/10.17863/CAM.15946 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609847.
Council of Science Editors:
Attwater J. Ice as a medium for RNA-catalysed RNA synthesis and evolution. [Doctoral Dissertation]. University of Cambridge; 2011. Available from: https://doi.org/10.17863/CAM.15946 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.609847
University of Cambridge
11.
Attwater, James.
Ice as a medium for RNA-catalysed RNA synthesis and evolution.
Degree: PhD, 2011, University of Cambridge
URL: https://www.repository.cam.ac.uk/handle/1810/246525https://www.repository.cam.ac.uk/bitstream/1810/246525/2/license.txt
;
https://www.repository.cam.ac.uk/bitstream/1810/246525/3/license_rdf
;
https://www.repository.cam.ac.uk/bitstream/1810/246525/6/James%20Attwater%20Thesis.pdf.txt
;
https://www.repository.cam.ac.uk/bitstream/1810/246525/7/James%20Attwater%20Thesis.pdf.jpg
► A critical event in the origin of life is thought to have been the emergence of a molecule capable of self-replication and evolution. According to…
(more)
▼ A critical event in the origin of life is thought to have been the emergence of a molecule capable of self-replication and evolution. According to the RNA World hypothesis, this could have been an RNA polymerase ribozyme capable of generating copies of itself from simple nucleotide precursors. In vitro evolution experiments have provided modern examples of such ribozymes, such as the R18 RNA polymerase ribozyme, exhibiting basic levels of this crucial catalytic activity; R18’s activity, however, falls far short of that required of an RNA replicase, leaving unanswered the question of whether RNA can catalyse its self-replication.
This thesis describes the development and use of a novel in vitro selection system, Compartmentalised Bead-Tagging (CBT), to isolate variants of the R18 ribozyme with improved sequence generality and extension capabilities. CBT evolution and engineering of polymerase ribozymes, together with RNA template evolution, allowed the synthesis of RNA molecules over 100 nucleotides long, as well as the RNA-catalysed transcription of a catalytic hammerhead ribozyme. This demonstrates the catalytic capabilities of ribozyme polymerases.
The R18 ribozyme was also exploited as an analogue of a primordial replicase, to determine replicase behaviour in different reaction environments. Substantial ribozyme polymerisation occurred at −7˚C in the liquid eutectic phase of water-ice; increased ribozyme stability at these low temperatures allowed longer extension products to be generated than at ambient temperatures. The concentration effect of eutectic phase formation could also yield RNA synthesis from dilute solutions of substrates, and provide quasicellular compartmentalisation of ribozymes. These beneficial physicochemical features of ice make it a potential protocellular medium for the emergence of primordial replicases.
Ice also could serve as a medium for CBT, allowing the isolation of a polymerase ribozyme adapted to the low temperatures in the ice phase, demonstrating the primordial potential and modern feasibility of ribozyme evolution in ice.
Subjects/Keywords: RNA; Ribozyme; Origin of Life; RNA world; Ice
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APA ·
Chicago ·
MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Attwater, J. (2011). Ice as a medium for RNA-catalysed RNA synthesis and evolution. (Doctoral Dissertation). University of Cambridge. Retrieved from https://www.repository.cam.ac.uk/handle/1810/246525https://www.repository.cam.ac.uk/bitstream/1810/246525/2/license.txt ; https://www.repository.cam.ac.uk/bitstream/1810/246525/3/license_rdf ; https://www.repository.cam.ac.uk/bitstream/1810/246525/6/James%20Attwater%20Thesis.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/246525/7/James%20Attwater%20Thesis.pdf.jpg
Chicago Manual of Style (16th Edition):
Attwater, James. “Ice as a medium for RNA-catalysed RNA synthesis and evolution.” 2011. Doctoral Dissertation, University of Cambridge. Accessed January 26, 2021.
https://www.repository.cam.ac.uk/handle/1810/246525https://www.repository.cam.ac.uk/bitstream/1810/246525/2/license.txt ; https://www.repository.cam.ac.uk/bitstream/1810/246525/3/license_rdf ; https://www.repository.cam.ac.uk/bitstream/1810/246525/6/James%20Attwater%20Thesis.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/246525/7/James%20Attwater%20Thesis.pdf.jpg.
MLA Handbook (7th Edition):
Attwater, James. “Ice as a medium for RNA-catalysed RNA synthesis and evolution.” 2011. Web. 26 Jan 2021.
Vancouver:
Attwater J. Ice as a medium for RNA-catalysed RNA synthesis and evolution. [Internet] [Doctoral dissertation]. University of Cambridge; 2011. [cited 2021 Jan 26].
Available from: https://www.repository.cam.ac.uk/handle/1810/246525https://www.repository.cam.ac.uk/bitstream/1810/246525/2/license.txt ; https://www.repository.cam.ac.uk/bitstream/1810/246525/3/license_rdf ; https://www.repository.cam.ac.uk/bitstream/1810/246525/6/James%20Attwater%20Thesis.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/246525/7/James%20Attwater%20Thesis.pdf.jpg.
Council of Science Editors:
Attwater J. Ice as a medium for RNA-catalysed RNA synthesis and evolution. [Doctoral Dissertation]. University of Cambridge; 2011. Available from: https://www.repository.cam.ac.uk/handle/1810/246525https://www.repository.cam.ac.uk/bitstream/1810/246525/2/license.txt ; https://www.repository.cam.ac.uk/bitstream/1810/246525/3/license_rdf ; https://www.repository.cam.ac.uk/bitstream/1810/246525/6/James%20Attwater%20Thesis.pdf.txt ; https://www.repository.cam.ac.uk/bitstream/1810/246525/7/James%20Attwater%20Thesis.pdf.jpg
Boston University
12.
Goldford, Joshua Elliot.
Multi-scale metabolism: from the origin of life to microbial ecology.
Degree: PhD, Bioinformatics GRS, 2018, Boston University
URL: http://hdl.handle.net/2144/33239
► Metabolism is a key attribute of life on Earth at multiple spatial and temporal scales, involved in processes ranging from cellular reproduction to biogeochemical cycles.…
(more)
▼ Metabolism is a key attribute of
life on Earth at multiple spatial and temporal scales, involved in processes ranging from cellular reproduction to biogeochemical cycles. While metabolic network modeling approaches have enabled significant progress at the cellular-scale, extending these techniques to address questions at both the ecosystem and planetary-scales remains highly unexplored. In this thesis, I integrate various multi-scale metabolic network modeling approaches to address key questions with regard to both the long-term evolution of metabolism in the biosphere and the metabolic processes that take place in complex microbial communities.
The first portion of my thesis work, focused on the evolution of ancient metabolic networks, attempts to model the emergence of ecosystem-level metabolism from simple geochemical precursors. By integrating network-based algorithms, physiochemical constraints, and geochemical estimates of ancient Earth, I explored whether a complex metabolic network could have emerged without phosphate, a key molecular component in modern-day living systems, known to be poorly available at the onset of
life. We found that phosphate may have not been essential in early living systems, and that thioesters may have been the primitive energy currency in ancient metabolic networks. By generalizing this approach to explore the scope of geochemical scenarios that could have given rise to living systems, I found that other key biomolecules, including fixed nitrogen, may have not been required at the earliest stages in biochemical evolution. The second portion of my thesis deals with a different aspect of ecosystem-level metabolism, namely the role of metabolism in shaping the structure of microbial communities. I studied the relationship between metabolism and microbial community assembly using microbial communities grown in synthetic laboratory environments. We found that a generalized statistical consumer-resource model recapitulates the emergent phenomena observed in these experiments.
Future work could seek to better clarify the connection between the fundamental rules that led to life’s emergence over 4 billion years ago and the laws that shape microbial ecosystems today. An ecosystems-level metabolic perspective may aid in our understanding of both the emergence and maintenance of the biosphere.
Advisors/Committee Members: Segre, Daniel (advisor).
Subjects/Keywords: Bioinformatics; Metabolic modeling; Metabolism; Microbial ecology; Origin of life; Thermodynamics
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APA ·
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MLA ·
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Export
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APA (6th Edition):
Goldford, J. E. (2018). Multi-scale metabolism: from the origin of life to microbial ecology. (Doctoral Dissertation). Boston University. Retrieved from http://hdl.handle.net/2144/33239
Chicago Manual of Style (16th Edition):
Goldford, Joshua Elliot. “Multi-scale metabolism: from the origin of life to microbial ecology.” 2018. Doctoral Dissertation, Boston University. Accessed January 26, 2021.
http://hdl.handle.net/2144/33239.
MLA Handbook (7th Edition):
Goldford, Joshua Elliot. “Multi-scale metabolism: from the origin of life to microbial ecology.” 2018. Web. 26 Jan 2021.
Vancouver:
Goldford JE. Multi-scale metabolism: from the origin of life to microbial ecology. [Internet] [Doctoral dissertation]. Boston University; 2018. [cited 2021 Jan 26].
Available from: http://hdl.handle.net/2144/33239.
Council of Science Editors:
Goldford JE. Multi-scale metabolism: from the origin of life to microbial ecology. [Doctoral Dissertation]. Boston University; 2018. Available from: http://hdl.handle.net/2144/33239
Columbia University
13.
Chen, Jingjing.
A Bayesian Approach to the Understanding of Exoplanet Populations and the Origin of Life.
Degree: 2018, Columbia University
URL: https://doi.org/10.7916/D8QN7QPD
► The study of extrasolar planets, or exoplanets for short, has developed rapidly over the last decade. While we have spent much effort building both ground-based…
(more)
▼ The study of extrasolar planets, or exoplanets for short, has developed rapidly over the last decade. While we have spent much effort building both ground-based and space telescopes to search for exoplanets, it is even more important that we use the observational data wisely to understand them. Exoplanets are of great interest to both astronomers and the general public because they have shown varieties of characteristics that we couldn't have anticipated from planets within our Solar System. To properly analyze the exoplanet populations, we need the tools of statistics. Therefore, in Chapter 1, I describe the science background as well as the statistical methods which will be applied in this thesis. In Chapter 2, I discuss how to train a hierarchical Bayesian model in detail to fit the relationship between masses and radii of exoplanets and categorize exoplanets based on that. A natural application that comes with the model is to use it for future observations of mass/radius and predict the other measurement. Thus I will show two application cases in Chapter 3. Composition of an exoplanet is also very much constrained by its mass and radius. I will show an easy way to constrain the composition of exoplanets in Chapter 4 and discuss how more complicated methods can be applied in future works.
Of even greater interest is whether there is life elsewhere in the Universe. Although the future discovery of extraterrestrial life might be totally a fluke, a clear sketched plan always gives us some directions. Research in this area is still very preliminary. Fortunately, besides directly searching for extraterrestrial life, we can also apply statistical reasoning to first estimate the rate of abiogenesis, which will give us some clue on the question of whether there is extraterrestrial life in a probabilistic way. In Chapter 5, I will discuss how different methods can constrain the abiogenesis rate in an informatics perspective.
Finally I will give a brief summary in Chapter 6.
Subjects/Keywords: Astronomy; Extrasolar planets; Life – Origin; Statistics; Bayesian statistical decision theory
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APA ·
Chicago ·
MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Chen, J. (2018). A Bayesian Approach to the Understanding of Exoplanet Populations and the Origin of Life. (Doctoral Dissertation). Columbia University. Retrieved from https://doi.org/10.7916/D8QN7QPD
Chicago Manual of Style (16th Edition):
Chen, Jingjing. “A Bayesian Approach to the Understanding of Exoplanet Populations and the Origin of Life.” 2018. Doctoral Dissertation, Columbia University. Accessed January 26, 2021.
https://doi.org/10.7916/D8QN7QPD.
MLA Handbook (7th Edition):
Chen, Jingjing. “A Bayesian Approach to the Understanding of Exoplanet Populations and the Origin of Life.” 2018. Web. 26 Jan 2021.
Vancouver:
Chen J. A Bayesian Approach to the Understanding of Exoplanet Populations and the Origin of Life. [Internet] [Doctoral dissertation]. Columbia University; 2018. [cited 2021 Jan 26].
Available from: https://doi.org/10.7916/D8QN7QPD.
Council of Science Editors:
Chen J. A Bayesian Approach to the Understanding of Exoplanet Populations and the Origin of Life. [Doctoral Dissertation]. Columbia University; 2018. Available from: https://doi.org/10.7916/D8QN7QPD
University of Missouri – Columbia
14.
Novy, Ronald, 1965-.
Home aestheticus : species being and the struggle for existence.
Degree: PhD, 2007, University of Missouri – Columbia
URL: http://hdl.handle.net/10355/5946
► [ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] In this paper, I argue for the homo aestheticus thesis - the claim that…
(more)
▼ [ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] In this paper, I argue for the homo aestheticus thesis - the claim that our species nature is that of artistic producer and consumer; that this nature is a selected-for, biobehavioral trait; and that to be alienated is to be living apart from this basic nature. Marx regularly uses aesthetic language to distinguish human from animal labor; perversion of creative labor - the reduction of human to animal - is the root of alienation. I take Marx and Engels at their word when, they praise
Origin of Species for containing - the basis in natural history for our views.This claim turns on Darwin's use of the term - struggle for existence. In the West, Darwin's theory of natural selection has been understood through a Malthusian lens; it need not be. This - Darwin without Malthus - position was developed primarily by naturalists working in the Russian East and explicated most famously in Kropotkin's Mutual Aid; such an understanding of natural selection I suggest is what Marx and Engels have in mind. The claim then is that evolution has produced in us a species nature to modify the natural world through creative labor. It is this which separates us from the other biological creatures: our humanization of the environment requires the development of characteristics and tools necessary to meet these newly created needs. As social and historical creatures both producing and produced by this dialectic of need and creativity, human nature is simply not the sort of thing that is either wholly fixed or wholly plastic.
Advisors/Committee Members: Bien, Joseph, 1936- (advisor).
Subjects/Keywords: Life – Origin; Philosophy of nature
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APA ·
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Export
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APA (6th Edition):
Novy, Ronald, 1. (2007). Home aestheticus : species being and the struggle for existence. (Doctoral Dissertation). University of Missouri – Columbia. Retrieved from http://hdl.handle.net/10355/5946
Chicago Manual of Style (16th Edition):
Novy, Ronald, 1965-. “Home aestheticus : species being and the struggle for existence.” 2007. Doctoral Dissertation, University of Missouri – Columbia. Accessed January 26, 2021.
http://hdl.handle.net/10355/5946.
MLA Handbook (7th Edition):
Novy, Ronald, 1965-. “Home aestheticus : species being and the struggle for existence.” 2007. Web. 26 Jan 2021.
Vancouver:
Novy, Ronald 1. Home aestheticus : species being and the struggle for existence. [Internet] [Doctoral dissertation]. University of Missouri – Columbia; 2007. [cited 2021 Jan 26].
Available from: http://hdl.handle.net/10355/5946.
Council of Science Editors:
Novy, Ronald 1. Home aestheticus : species being and the struggle for existence. [Doctoral Dissertation]. University of Missouri – Columbia; 2007. Available from: http://hdl.handle.net/10355/5946
University of South Florida
15.
Szenay, Brian Craig.
Modeling Potential Chemical Environments: Implications for Astrobiology.
Degree: 2013, University of South Florida
URL: https://scholarcommons.usf.edu/etd/4847
► Modeling chemical environments is an important step to understanding the diversity of prebiotic systems that may have formed on the early earth or potentially can…
(more)
▼ Modeling chemical environments is an important step to understanding the diversity of prebiotic systems that may have formed on the early earth or potentially can occur on other worlds. By using the modern Earth as a test case, these models predict scenarios with systems more conducive to the formation of the organic molecules that are important to life. Here we use the equilibrium thermodynamic modeling program HSC Chem to investigate prebiotic environments. This program uses the raw material that the user inputs into the system in order to calculate the change in amounts of chemical species forming as a function of temperature and pressure using equilibrium (batch reactor) chemistry. Our results show that that ferrous ion (Fe2+), which may be important in the early formation of organic molecules on Earth, is most abundant in the aqueous phase where the atmosphere contains carbon dioxide as a major constituent. A pure methane atmosphere exhibits the lowest concentrations of this ion, and mixtures tend to end up in between the two extremes. Additionally, we have determined the pH of early oceans, which has implications for biomineralization, chemical reactions, and mineral chemistry. We see that the CO2 atmosphere, and to some extent, the mixtures and CH4 atmospheres, exhibit near neutral pHs. These results allow prediction of processes that might have taken place and could have impacted the development of life on the early earth.
Subjects/Keywords: early geochemistry; iron; origin of life; phosphorus; prebiotic evolution; Geochemistry
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APA ·
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Export
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APA (6th Edition):
Szenay, B. C. (2013). Modeling Potential Chemical Environments: Implications for Astrobiology. (Thesis). University of South Florida. Retrieved from https://scholarcommons.usf.edu/etd/4847
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Szenay, Brian Craig. “Modeling Potential Chemical Environments: Implications for Astrobiology.” 2013. Thesis, University of South Florida. Accessed January 26, 2021.
https://scholarcommons.usf.edu/etd/4847.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Szenay, Brian Craig. “Modeling Potential Chemical Environments: Implications for Astrobiology.” 2013. Web. 26 Jan 2021.
Vancouver:
Szenay BC. Modeling Potential Chemical Environments: Implications for Astrobiology. [Internet] [Thesis]. University of South Florida; 2013. [cited 2021 Jan 26].
Available from: https://scholarcommons.usf.edu/etd/4847.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Szenay BC. Modeling Potential Chemical Environments: Implications for Astrobiology. [Thesis]. University of South Florida; 2013. Available from: https://scholarcommons.usf.edu/etd/4847
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of New South Wales
16.
Lutherborrow, Mark Aaron.
Molecular events surrounding secretory granule biogenesis in transgenic hormone producing liver cell lines.
Degree: Medicine, 2007, University of New South Wales
URL: http://handle.unsw.edu.au/1959.4/33148
;
https://unsworks.unsw.edu.au/fapi/datastream/unsworks:1746/SOURCE02?view=true
► Secretory granule biogenesis describes the events leading up to the budding of a nascent granule from the trans Golgi network. Literature surrounding secretory granule biogenesis…
(more)
▼ Secretory granule biogenesis describes the events leading up to the budding of a nascent granule from the trans Golgi network. Literature surrounding secretory granule biogenesis is conflicting and has generated much debate. This thesis aims to address the important issues of this debate by utilizing the insulin-producing liver cell line HUH7-ins. This cell line has been shown to synthesize, store and secrete mature insulin in response to glucose via the possession of secretory granules. Using microarraytechnology the gene expression profile of HUH7-ins cells was compared with parental HUH7 cells, hoping to identify possible candidate genes contributing to secretory granule biogenesis. 164 genes were shown to be differentially expressed although no known granulogenic protein exhibited a change in expression. The data did suggest anervous system differentiation event and implicates myosin Vc in the regulated secretion of insulin. HUH7-ins cells express a number of granulogenic protein mRNAs and while chromogranin B (CgB) protein level remained constant upon insulin expression, a significant increase in the level of chromogranin A (CgA) was observed,though the significance of this increase in expression is unknown. The over-expression of CgA in a clone of HUH7-ins that did not possess the regulated secretory pathway was unable to rescue the regulated secretory pathway, suggesting that CgA expression alone is unable to form secretory granules in our model. To determine if the secretory granule biogenesis seen in HUH7-ins cells was specific to insulin, three prohormones of different neuroendocrine origin were over-expressed in HUH7 cells; amylin ( cell),pancreatic polypeptide (pancreatic islet) and proopiomelanocortin (pituitary). None of these prohormones were able to form structures in the cytoplasm that resembled secretory granules by immunofluorescent microscopy, nor did they induce the expression of CgA. No prohormone was detected in cell lysates or conditioned media, raising the possibility that these exogenous prohormone aggregates are trafficked to the lysosomal/endosomal system for degradation. This study provides significant information regarding the genome-wide expression changes induced upon secretory granule biogenesis in a liver cell line, describes the lack of effect of CgA in this eventand suggests that secretory granule biogenesis in this liver cell line is specific to insulin.
Subjects/Keywords: Hormones; Liver cells; Life – Origin
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APA (6th Edition):
Lutherborrow, M. A. (2007). Molecular events surrounding secretory granule biogenesis in transgenic hormone producing liver cell lines. (Doctoral Dissertation). University of New South Wales. Retrieved from http://handle.unsw.edu.au/1959.4/33148 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:1746/SOURCE02?view=true
Chicago Manual of Style (16th Edition):
Lutherborrow, Mark Aaron. “Molecular events surrounding secretory granule biogenesis in transgenic hormone producing liver cell lines.” 2007. Doctoral Dissertation, University of New South Wales. Accessed January 26, 2021.
http://handle.unsw.edu.au/1959.4/33148 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:1746/SOURCE02?view=true.
MLA Handbook (7th Edition):
Lutherborrow, Mark Aaron. “Molecular events surrounding secretory granule biogenesis in transgenic hormone producing liver cell lines.” 2007. Web. 26 Jan 2021.
Vancouver:
Lutherborrow MA. Molecular events surrounding secretory granule biogenesis in transgenic hormone producing liver cell lines. [Internet] [Doctoral dissertation]. University of New South Wales; 2007. [cited 2021 Jan 26].
Available from: http://handle.unsw.edu.au/1959.4/33148 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:1746/SOURCE02?view=true.
Council of Science Editors:
Lutherborrow MA. Molecular events surrounding secretory granule biogenesis in transgenic hormone producing liver cell lines. [Doctoral Dissertation]. University of New South Wales; 2007. Available from: http://handle.unsw.edu.au/1959.4/33148 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:1746/SOURCE02?view=true
Portland State University
17.
Vaidya, Nilesh.
Spontaneous Cooperative Assembly of Replicative Catalytic RNA Systems.
Degree: PhD, Chemistry, 2012, Portland State University
URL: https://pdxscholar.library.pdx.edu/open_access_etds/934
► The RNA World hypothesis proposes a period of time during the origins of life in which RNA molecules were the only source of both…
(more)
▼ The RNA World hypothesis proposes a period of time during the origins of
life in which RNA molecules were the only source of both genotypes and phenotypes. Although a vast amount of evidence has been obtained in support of this hypothesis, a few critical demonstrations are lacking. A most crucial one is a demonstration of self-replication of RNA molecule from prebiotic soup. Previously in the Lehman laboratory, it has been demonstrated that a 198-nucleotide molecule derived from the Azoarcus group I intron can self-assemble from up to four fragments of RNA via recombination. Furthermore, the covalent full-length molecules are catalytically active and can make copies of themselves from the remaining pieces in the solution leading to their autocatalytic growth. I was able to demonstrate how this recombination system can overcome different obstacles and evolve to be an efficient replicating system. I discovered the ability of a single RNA fragment to be multifunctional in a single reaction pathway during RNA recombination events that avoids the necessity of multiple genotypes. I also confirmed the capacity of self-replicating ribozymes to form cooperative catalytic cycles and networks that would potentially prevent informational decay. Finally, I have discovered a recycling phenomenon in the RNA recombination system that exploits dynamic covalent chemistry. Recycling provides the earliest replicating system with adequate concentrations of reagents and ability to explore sequence space. Together these findings have improved our understanding of RNA recombination and bolstered the plausibility of the RNA World.
Advisors/Committee Members: Niles Lehman.
Subjects/Keywords: Catalytic RNA; RNA – Research; Life – Origin; Biochemistry; Chemistry
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APA (6th Edition):
Vaidya, N. (2012). Spontaneous Cooperative Assembly of Replicative Catalytic RNA Systems. (Doctoral Dissertation). Portland State University. Retrieved from https://pdxscholar.library.pdx.edu/open_access_etds/934
Chicago Manual of Style (16th Edition):
Vaidya, Nilesh. “Spontaneous Cooperative Assembly of Replicative Catalytic RNA Systems.” 2012. Doctoral Dissertation, Portland State University. Accessed January 26, 2021.
https://pdxscholar.library.pdx.edu/open_access_etds/934.
MLA Handbook (7th Edition):
Vaidya, Nilesh. “Spontaneous Cooperative Assembly of Replicative Catalytic RNA Systems.” 2012. Web. 26 Jan 2021.
Vancouver:
Vaidya N. Spontaneous Cooperative Assembly of Replicative Catalytic RNA Systems. [Internet] [Doctoral dissertation]. Portland State University; 2012. [cited 2021 Jan 26].
Available from: https://pdxscholar.library.pdx.edu/open_access_etds/934.
Council of Science Editors:
Vaidya N. Spontaneous Cooperative Assembly of Replicative Catalytic RNA Systems. [Doctoral Dissertation]. Portland State University; 2012. Available from: https://pdxscholar.library.pdx.edu/open_access_etds/934
University of Cambridge
18.
Ding, Yang.
Self-assembled Precipitation Membranes and the Implications for Natural Sciences.
Degree: PhD, 2020, University of Cambridge
URL: https://www.repository.cam.ac.uk/handle/1810/308261
► Far from thermodynamic equilibrium, many precipitation reactions can generate complex membrane structures. Such membranes are of great research interest in fields ranging from chemical engineering…
(more)
▼ Far from thermodynamic equilibrium, many precipitation reactions can generate complex membrane structures. Such membranes are of great research interest in fields ranging from chemical engineering to geophysics, and even biology where they are thought to have played a vital role in the origin of life. Usually, the transport of chemicals by combined buoyancy, osmotic and diffusive mechanisms, support the precipitation reaction. In order to study these transport processes across a growing selective membrane, we use reactions forming chemical gardens. We focus on four studies: one in a micro-fluidic reactor where flow is forced by a pump and others in a Hele-Shaw cell where the flow is driven by the membrane itself. In the first, with externally forced flow, the growth of a wavy precipitate membrane is observed. We establish that its growth is controlled by transverse diffusion and dispersion of the ions in solution. We develop a precipitation model, taking into account diffusion of ions through the precipitate and through an adjacent gel layer. Results from our theory are in excellent agreement with the measurements and show that a wavy precipitate surface can enhance the transverse transport of ions by extracting energy from a longitudinal flow field. In the second study, the chemical gardens are formed in a horizontal Hele-Shaw cell. We examine the changes of the membrane morphology associated with the concentration of reactants. We also survey the growth rate of membrane, which is determined by the osmotic flow as well as by concentration effects. The motion of the fluid is visualized in order to understand the transport process. The pressure inside the membrane structure is measured and different patterns of pressure changes are identified. A pressure-concentration model is proposed to explain the harmonic pressure changes of this system. In our third study, we observe that a chemical garden confined to two dimensions is a clock reaction involving a phase change, so that after a reproducible and controllable induction period it explodes. The explosion of chemical garden is caused by the decreasing permeability of membrane, owing to the gradual blocking of its pores by the precipitate. A pressure-concentration-thickness model is developed to analyse the explosive system. In our final study, we return to a classic chemical garden where gravity force is of relevance. Oscillatory growth of tubes in the vertical direction is witnessed. The chemical gardens explode at a late phase of experiments, with longer life times than the corresponding horizontal cases. We also observe descending flow with a surrounding precipitation structure, which is controlled by gravity.
Subjects/Keywords: chemobrionics; chemical gardens; fluid dynamics; origin of life; clock reactions
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APA (6th Edition):
Ding, Y. (2020). Self-assembled Precipitation Membranes and the Implications for Natural Sciences. (Doctoral Dissertation). University of Cambridge. Retrieved from https://www.repository.cam.ac.uk/handle/1810/308261
Chicago Manual of Style (16th Edition):
Ding, Yang. “Self-assembled Precipitation Membranes and the Implications for Natural Sciences.” 2020. Doctoral Dissertation, University of Cambridge. Accessed January 26, 2021.
https://www.repository.cam.ac.uk/handle/1810/308261.
MLA Handbook (7th Edition):
Ding, Yang. “Self-assembled Precipitation Membranes and the Implications for Natural Sciences.” 2020. Web. 26 Jan 2021.
Vancouver:
Ding Y. Self-assembled Precipitation Membranes and the Implications for Natural Sciences. [Internet] [Doctoral dissertation]. University of Cambridge; 2020. [cited 2021 Jan 26].
Available from: https://www.repository.cam.ac.uk/handle/1810/308261.
Council of Science Editors:
Ding Y. Self-assembled Precipitation Membranes and the Implications for Natural Sciences. [Doctoral Dissertation]. University of Cambridge; 2020. Available from: https://www.repository.cam.ac.uk/handle/1810/308261
19.
Fryar, Randall Scott.
The Non-Ending Search for a Pre-DNA Replicator: Richard Dawkins and the Problem of Abiogenesis.
Degree: 2014, Southern Baptist Theological Seminary
URL: http://hdl.handle.net/10392/4613
► This dissertation provides a rebuttal to the claims of Richard Dawkins in explaining the origin of life. The bulk of the ensuing analysis challenges his…
(more)
▼ This dissertation provides a rebuttal to the claims of Richard Dawkins in explaining the
origin of
life. The bulk of the ensuing analysis challenges his philosophical assumptions as it notes his vacillation between several models over time. The study further details Dawkins's multifaceted approach to the problem as it points out a number of errors permeating his general methodology and reasoning.
Advisors/Committee Members: Cabal, Theodore J (advisor).
Subjects/Keywords: Dawkins, Richard, 1941-; Life – Origin.
…Life on Earth1
Though Oparin made this profound statement in regard to the origin of life in… …Oparin, The Origin of Life on the Earth (New York: Academic Press, 1957),
101. Early… …the origin of life a greater riddle than it was before: we have acquired new
and deeper… …Conferences including the 2012 event on the “origin of life.” This article was also
presented at the… …the Carnegie Institution of Washington.
9
Within origin of life research, the “top-down…
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APA (6th Edition):
Fryar, R. S. (2014). The Non-Ending Search for a Pre-DNA Replicator: Richard Dawkins and the Problem of Abiogenesis. (Thesis). Southern Baptist Theological Seminary. Retrieved from http://hdl.handle.net/10392/4613
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Fryar, Randall Scott. “The Non-Ending Search for a Pre-DNA Replicator: Richard Dawkins and the Problem of Abiogenesis.” 2014. Thesis, Southern Baptist Theological Seminary. Accessed January 26, 2021.
http://hdl.handle.net/10392/4613.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Fryar, Randall Scott. “The Non-Ending Search for a Pre-DNA Replicator: Richard Dawkins and the Problem of Abiogenesis.” 2014. Web. 26 Jan 2021.
Vancouver:
Fryar RS. The Non-Ending Search for a Pre-DNA Replicator: Richard Dawkins and the Problem of Abiogenesis. [Internet] [Thesis]. Southern Baptist Theological Seminary; 2014. [cited 2021 Jan 26].
Available from: http://hdl.handle.net/10392/4613.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Fryar RS. The Non-Ending Search for a Pre-DNA Replicator: Richard Dawkins and the Problem of Abiogenesis. [Thesis]. Southern Baptist Theological Seminary; 2014. Available from: http://hdl.handle.net/10392/4613
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of California – San Diego
20.
Martin, Eric Collin.
Examining life's origins : history and epistemic principles in the search for the origins of life.
Degree: 2010, University of California – San Diego
URL: http://www.escholarship.org/uc/item/09p75718
► My dissertation provides a novel philosophical and historical analysis of origins of life research, a scientific field that poses significant conceptual challenges to evolutionary theory,…
(more)
▼ My dissertation provides a novel philosophical and historical analysis of origins of life research, a scientific field that poses significant conceptual challenges to evolutionary theory, standard experimental methodology, and theory integration across disciplines. The origin of life is sometimes considered "the most fundamental problem in biology." Despite its theoretical significance, the field of study is fraught with fundamental disagreements over theories, methods and approaches. The origin of life presents a boundary problem for central biological processes, including natural selection, which presupposes the existence of an enormously complex physical system of replication that must have been absent in the emergence of life. Without natural selection, other forces must have driven the origin of life, and I illustrate which alternative explanations are may be involved in explaining life's origin. Such explanations have sometimes been associated with critical receptions of standard neo-Darwinian theory, so far from being independent of evolutionary principles, they have been connected with evolutionary theory in complex ways. I further investigate the heuristics used to evaluate the new discoveries in the origin of life. One of the most important such heuristics is continuity : an insistence that transformations in the path to life display no saltatory transitions. I use case studies to show how the principle of continuity is not used consistently across research groups in origin of life research, and how its invocation depends on background assumptions about the likelihood of success of alternative research programs. I conclude that the principle of continuity has been, in practice, either unhelpful or even positively harmful to research into life's origins. The topic of the origin of life underwent a remarkable transformation in the 20th century, from a question disparaged as speculative metaphysics to a legitimate field of scientific inquiry. Central to this transition was the British polymath J.B.S. Haldane. Haldane brought the question of life's origin into mainstream scientific investigation with his 1929 hypothesis of life's emergence from the "hot dilute soup" of Earth's early environment. This theory arose in the context of a protracted debate on holism and mechanism. I show how that philosophical debate figured in Haldane's philosophy and science, and what intellectual and social forces were acting on Haldane's novel chemical-evolutionary proposal for life's genesis
Subjects/Keywords: UCSD Dissertations, Academic Philosophy (Science studies) (Discipline); Life Origin; Creation; Continuity; Philosophy Science
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APA (6th Edition):
Martin, E. C. (2010). Examining life's origins : history and epistemic principles in the search for the origins of life. (Thesis). University of California – San Diego. Retrieved from http://www.escholarship.org/uc/item/09p75718
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Martin, Eric Collin. “Examining life's origins : history and epistemic principles in the search for the origins of life.” 2010. Thesis, University of California – San Diego. Accessed January 26, 2021.
http://www.escholarship.org/uc/item/09p75718.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Martin, Eric Collin. “Examining life's origins : history and epistemic principles in the search for the origins of life.” 2010. Web. 26 Jan 2021.
Vancouver:
Martin EC. Examining life's origins : history and epistemic principles in the search for the origins of life. [Internet] [Thesis]. University of California – San Diego; 2010. [cited 2021 Jan 26].
Available from: http://www.escholarship.org/uc/item/09p75718.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Martin EC. Examining life's origins : history and epistemic principles in the search for the origins of life. [Thesis]. University of California – San Diego; 2010. Available from: http://www.escholarship.org/uc/item/09p75718
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
21.
Roca, Flávio Oliveira.
Contribuição de conceitos químicos ao estudo da origem da vida na disciplina de biologia.
Degree: Mestrado, Educação, 2012, University of São Paulo
URL: http://www.teses.usp.br/teses/disponiveis/48/48134/tde-04072012-101801/
;
► Esta pesquisa apresenta os resultados de um levantamento empírico de livros didáticos de Biologia e Química aprovados no PNLEM 2007, no sentido de investigar as…
(more)
▼ Esta pesquisa apresenta os resultados de um levantamento empírico de livros didáticos de Biologia e Química aprovados no PNLEM 2007, no sentido de investigar as demandas de conceitos químicos no estudo de uma temática própria da disciplina de Biologia: a origem da vida. Adicionalmente, esta dissertação coteja essas demandas conceituais com os correspondentes saberes químicos sequenciados nos capítulos das coleções de Química e discute a potencial interlocução entre os conjuntos de saberes das duas disciplinas, visto que fazem parte da mesma área do conhecimento escolar. Considerando-se todas as obras divididas em três volumes um para cada ano do Ensino Médio e excetuando-se os volumes únicos, foram analisados os capítulos que tratam da origem da vida em quatro coleções de Biologia e todo o conteúdo programático de duas obras de Química. Reconhecendo a relevância do livro didático no cenário educacional brasileiro, o caráter notadamente disciplinar do currículo e as especificidades do ensino de Ciências, este trabalho reúne argumentos teóricos que fundamentam a necessidade de um olhar abrangente sobre a realidade, sempre complexa e multifacetada.
This research presents the results of an empirical survey from textbooks of Biology and Chemistry approved in PNLEM 2007, to investigate the demands of chemical concepts in the study of one the subjects in Biology: the origin of life. In addition to that, this dissertation collates these conceptual demands with the corresponding chemical knowledge sequenced in chapters of the chemical collections and discusses the potential dialogue between the sets of knowledge of those two disciplines, as part of the same area of school knowledge. Considering the works divided into three volumes one for each year of high school and except for the single volumes, were analyzed the chapters dealing with the origin of life in four collections of Biology and whole academic program in two works of Chemistry. Recognizing the relevance of the textbook in Brazilian educational scenario, the notably disciplinary character of the curriculum and the specificities of Natural Sciences who originated the school disciplines of Biology and Chemistry, this work gathers theoretical arguments that justify the need for a comprehensive look at the reality, always complex and multifaceted.
Advisors/Committee Members: Bizzo, Nelio Marco Vincenzo.
Subjects/Keywords: Ensino de ciências; Livro didático; Origem da vida; Origin of life; Science teaching; Textbook
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APA (6th Edition):
Roca, F. O. (2012). Contribuição de conceitos químicos ao estudo da origem da vida na disciplina de biologia. (Masters Thesis). University of São Paulo. Retrieved from http://www.teses.usp.br/teses/disponiveis/48/48134/tde-04072012-101801/ ;
Chicago Manual of Style (16th Edition):
Roca, Flávio Oliveira. “Contribuição de conceitos químicos ao estudo da origem da vida na disciplina de biologia.” 2012. Masters Thesis, University of São Paulo. Accessed January 26, 2021.
http://www.teses.usp.br/teses/disponiveis/48/48134/tde-04072012-101801/ ;.
MLA Handbook (7th Edition):
Roca, Flávio Oliveira. “Contribuição de conceitos químicos ao estudo da origem da vida na disciplina de biologia.” 2012. Web. 26 Jan 2021.
Vancouver:
Roca FO. Contribuição de conceitos químicos ao estudo da origem da vida na disciplina de biologia. [Internet] [Masters thesis]. University of São Paulo; 2012. [cited 2021 Jan 26].
Available from: http://www.teses.usp.br/teses/disponiveis/48/48134/tde-04072012-101801/ ;.
Council of Science Editors:
Roca FO. Contribuição de conceitos químicos ao estudo da origem da vida na disciplina de biologia. [Masters Thesis]. University of São Paulo; 2012. Available from: http://www.teses.usp.br/teses/disponiveis/48/48134/tde-04072012-101801/ ;
Harvard University
22.
Budin, Itay.
Physical Models for the Early Evolution of Cell Membranes.
Degree: PhD, Biochemistry, 2012, Harvard University
URL: http://nrs.harvard.edu/urn-3:HUL.InstRepos:9904006
► Cells use lipid membranes to organize and define their chemical environments. All cell membranes are based on a common structure: bilayers composed of phospholipids with…
(more)
▼ Cells use lipid membranes to organize and define their chemical environments. All cell membranes are based on a common structure: bilayers composed of phospholipids with two hydrocarbon chains. How did biology converge on this particular solution for cellular encapsulation? The first cell membranes are proposed to have assembled from simple, single-chain lipids, such as fatty acids and their derivatives, which would have been available in the prebiotic environment. Here we argue that the physical properties of fatty acid membranes would have made them well suited for a role as primitive cell membranes and predisposed their evolution to modern, phospholipid-based membranes. We first considered models for primitive membrane self-assembly, which faces significant concentration barriers due to the entropic cost of aggregation and the solubility of single-chain lipids. We therefore identified two physical mechanisms by which fatty acid membrane assembly can proceed from dilute solutions. Thermal diffusion columns, a proposed prebiotic concentration method, drive the formation of fatty acid vesicles by concentrating an initially isotropic solution past the critical concentration necessary for aggregation. Alternatively, mixtures of fatty acids with varying chain lengths, the expected products of abiotic lipid synthesis, intrinsically reduce the concentration barrier to aggregation through their polydispersity. These results motivated us to better understand the phase behavior of fatty acids in solutions. We found that the composition of fatty acid aggregates, whether vesicles or micelles, is also determined by concentration. Fatty acid vesicles feature significant amounts of coexisting micelles, whose abundance is enriched in low concentration solutions. We utilized this micelle-vesicle equilibrium to drive the growth of pre-existing fatty acid vesicles by changing amphiphile concentration. We next considered the evolution of phospholipid membranes, which was a critical and necessary step for the early evolution of cells. We found that the incorporation of even small amounts of phospholipids drives the growth of fatty acid vesicles by competition for monomers with neighboring vesicles lacking phospholipids. This competitive growth would have provided a strong selective advantage for primitive cells to evolve the catalytic machinery needed to synthesize phospholipids from their single-chain precursors. Growth is caused by any relative difference in phospholipid content, suggesting an evolutionary arms race among primitive cells for increasingly phospholipid membranes. What would have been the consequences for early cells of such a transition in membrane composition? We found that increasing phospholipid content inhibits the permeability of fatty acid membranes through changes in bilayer fluidity. For early heterotrophic cells, the emergence of increasingly phospholipid membranes would have therefore imposed new selective pressures for the evolution of membrane transport machinery and metabolism. Our model for early membrane…
Advisors/Committee Members: Szostak, Jack William (advisor), Berg, Howard (committee member), Guidotti, Guido (committee member), Miller, Chris (committee member).
Subjects/Keywords: biophysics; biochemistry; early evolution; fatty acids; membranes; origin of life; phospholipids; protocell
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APA (6th Edition):
Budin, I. (2012). Physical Models for the Early Evolution of Cell Membranes. (Doctoral Dissertation). Harvard University. Retrieved from http://nrs.harvard.edu/urn-3:HUL.InstRepos:9904006
Chicago Manual of Style (16th Edition):
Budin, Itay. “Physical Models for the Early Evolution of Cell Membranes.” 2012. Doctoral Dissertation, Harvard University. Accessed January 26, 2021.
http://nrs.harvard.edu/urn-3:HUL.InstRepos:9904006.
MLA Handbook (7th Edition):
Budin, Itay. “Physical Models for the Early Evolution of Cell Membranes.” 2012. Web. 26 Jan 2021.
Vancouver:
Budin I. Physical Models for the Early Evolution of Cell Membranes. [Internet] [Doctoral dissertation]. Harvard University; 2012. [cited 2021 Jan 26].
Available from: http://nrs.harvard.edu/urn-3:HUL.InstRepos:9904006.
Council of Science Editors:
Budin I. Physical Models for the Early Evolution of Cell Membranes. [Doctoral Dissertation]. Harvard University; 2012. Available from: http://nrs.harvard.edu/urn-3:HUL.InstRepos:9904006
Harvard University
23.
Blain, Jonathan Craig.
Non-Enzymatic Copying of Nucleic Acid Templates.
Degree: PhD, Biology: Medical Sciences, Division of, 2013, Harvard University
URL: http://nrs.harvard.edu/urn-3:HUL.InstRepos:11744416
► All known living cells contain a complex set of molecular machinery to support their growth and replication. However, the earliest cells must have been much…
(more)
▼ All known living cells contain a complex set of molecular machinery to support their growth and replication. However, the earliest cells must have been much simpler, consisting of a compartment and a genetic material to allow for Darwinian evolution. To study these intermediates, plausible model `protocells' must be synthesized in the laboratory since no fossils remain. Recent work has shown that fatty acids can self-assemble into vesicles that are able to grow and divide through simple mechanisms. However, a self-replicating protocell genome has not yet been developed. Here we discuss studies of systems that allow for the copying of nucleic acid templates without enzymes and how they could be developed into a genetic material.
Advisors/Committee Members: Szostak, Jack William (advisor), Ruvkun, Gary (committee member), Seed, Brian (committee member), Blower, Michael (committee member), McLaughlin, Larry (committee member), Liu, David (committee member), Walker, Suzanne (committee member).
Subjects/Keywords: Genetics; Biochemistry; Chemistry; Click chemistry; Origin of life; Protocell; Self replication; Synthetic biology
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APA (6th Edition):
Blain, J. C. (2013). Non-Enzymatic Copying of Nucleic Acid Templates. (Doctoral Dissertation). Harvard University. Retrieved from http://nrs.harvard.edu/urn-3:HUL.InstRepos:11744416
Chicago Manual of Style (16th Edition):
Blain, Jonathan Craig. “Non-Enzymatic Copying of Nucleic Acid Templates.” 2013. Doctoral Dissertation, Harvard University. Accessed January 26, 2021.
http://nrs.harvard.edu/urn-3:HUL.InstRepos:11744416.
MLA Handbook (7th Edition):
Blain, Jonathan Craig. “Non-Enzymatic Copying of Nucleic Acid Templates.” 2013. Web. 26 Jan 2021.
Vancouver:
Blain JC. Non-Enzymatic Copying of Nucleic Acid Templates. [Internet] [Doctoral dissertation]. Harvard University; 2013. [cited 2021 Jan 26].
Available from: http://nrs.harvard.edu/urn-3:HUL.InstRepos:11744416.
Council of Science Editors:
Blain JC. Non-Enzymatic Copying of Nucleic Acid Templates. [Doctoral Dissertation]. Harvard University; 2013. Available from: http://nrs.harvard.edu/urn-3:HUL.InstRepos:11744416
Texas Medical Center
24.
GADHIKAR, MAYUR ARVIND.
INVESTIGATING CHECKPOINT KINASES 1/2 AS NOVEL THERAPEUTIC TARGETS IN HEAD AND NECK SQUAMOUS CELL CARCINOMA.
Degree: PhD, 2014, Texas Medical Center
URL: https://digitalcommons.library.tmc.edu/utgsbs_dissertations/518
► Cisplatin, despite being the cornerstone chemotherapy for the treatment of head and neck squamous cell carcinoma (HNSCC), provides clinical benefits in just a subset…
(more)
▼ Cisplatin, despite being the cornerstone chemotherapy for the treatment of head and neck squamous cell carcinoma (HNSCC), provides clinical benefits in just a subset of patients. This together with the lack of biomarkers predicting therapeutic responses, have led to unacceptably high rate of treatment failures in HNSCC. TP53 is the most frequently mutated gene in HNSCC, and the effect of p53 loss or mutation on cisplatin responses in HNSCC is poorly understood. In the current study, we hypothesized that HNSCC cells respond to cisplatin in a p53 dependent manner and unambiguously show that presence of wild-type TP53 (wtp53) confers sensitivity to cisplatin treatment in HNSCC cells, whereas mutation or loss of TP53 imparts resistance to cisplatin treatment. Moreover, we report that senescence, but not apoptosis is the prominent cellular response to cisplatin in wtp53 HNSCC cells and that the cisplatin resistance in p53-null or -mutant TP53 cells is due to their inability to evoke senescence response. In an effort to find strategies of overcoming cisplatin resistance in p53-deficient HNSCC cells, we found that a synthetic lethal strategy through targeted inhibition of checkpoint kinases Chk1/2 leads to cisplatin sensitization of p53-deficient cells through induction of mitotic death. Serendipitously, we also found out that a significant subset (roughly 20%) of HNSCC cell lines are acutely sensitive to single agent checkpoint inhibitors and that Chk1, but not Chk2, mediates this sensitivity. Characterization of phenotypic and molecular responses to Chk1 inhibition in the Chk sensitive and resistant cells revealed induction of early S phase arrest and DNA damage/replication stress markers in the Chk sensitive, but not resistant cells. In addition, we also found that inhibition of Chk1 kinase led to aberrant increase in
origin of replication firings in the sensitive, but not resistant cells and that loss of cdk2 or treatment with Roscovitine rescues the lethal phenotype seen in the sensitive cells upon Chk1 inhibition. These results suggest that exquisite sensitivity to Chk1 inhibition in a subset of HNSCC cells could be due to these cells being in a pre-existing state of severe replication stress.
In summary, given the preponderance of p53 mutation in HNSCC and the widespread use of cisplatin in treating aggressive HNSCC, we provide preclinical evidence that cisplatin resistance of p53-deficient HNSCC cells can be overcome through inhibition of checkpoint kinases 1/2. These preclinical data suggest that Chk1/2 kinase is a promising therapeutic target in HNSCC and a precision approach using Chk inhibition in p53-mutant tumors may be feasible for the treatment of HNSCC. We also show that targeted inhibition of Chk1 alone imparts lethality in a significant subset of HNSCC cells by inducing an aberrant increase in
origin firings. These results suggest that targeting Chk1 alone could be therapeutically beneficial in a significant subset of HNSCC. Identifying those patients with HNSCC that are particularly sensitive…
Advisors/Committee Members: JEFFREY N. MYERS, MD, Ph.D., WALTER N. HITTELMAN, Ph.D., WILLIAM PLUNKETT, Ph.D..
Subjects/Keywords: Chk1; p53; Chk2; senescence; origin firings; Life Sciences; Medicine and Health Sciences
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APA (6th Edition):
GADHIKAR, M. A. (2014). INVESTIGATING CHECKPOINT KINASES 1/2 AS NOVEL THERAPEUTIC TARGETS IN HEAD AND NECK SQUAMOUS CELL CARCINOMA. (Doctoral Dissertation). Texas Medical Center. Retrieved from https://digitalcommons.library.tmc.edu/utgsbs_dissertations/518
Chicago Manual of Style (16th Edition):
GADHIKAR, MAYUR ARVIND. “INVESTIGATING CHECKPOINT KINASES 1/2 AS NOVEL THERAPEUTIC TARGETS IN HEAD AND NECK SQUAMOUS CELL CARCINOMA.” 2014. Doctoral Dissertation, Texas Medical Center. Accessed January 26, 2021.
https://digitalcommons.library.tmc.edu/utgsbs_dissertations/518.
MLA Handbook (7th Edition):
GADHIKAR, MAYUR ARVIND. “INVESTIGATING CHECKPOINT KINASES 1/2 AS NOVEL THERAPEUTIC TARGETS IN HEAD AND NECK SQUAMOUS CELL CARCINOMA.” 2014. Web. 26 Jan 2021.
Vancouver:
GADHIKAR MA. INVESTIGATING CHECKPOINT KINASES 1/2 AS NOVEL THERAPEUTIC TARGETS IN HEAD AND NECK SQUAMOUS CELL CARCINOMA. [Internet] [Doctoral dissertation]. Texas Medical Center; 2014. [cited 2021 Jan 26].
Available from: https://digitalcommons.library.tmc.edu/utgsbs_dissertations/518.
Council of Science Editors:
GADHIKAR MA. INVESTIGATING CHECKPOINT KINASES 1/2 AS NOVEL THERAPEUTIC TARGETS IN HEAD AND NECK SQUAMOUS CELL CARCINOMA. [Doctoral Dissertation]. Texas Medical Center; 2014. Available from: https://digitalcommons.library.tmc.edu/utgsbs_dissertations/518
25.
Franiatte, Michael.
Etude théorique et expérimentale de la biogenèse des systèmes hydrothermaux marins : une contribution à la recherche sur l'origine de la vie : Theorical and experimental study of submarine hydrothermal fluids Implications for origin of life.
Degree: Docteur es, Géosciences, 2011, Université Henri Poincaré – Nancy I
URL: http://www.theses.fr/2011NAN10054
► Les découvertes de systèmes hydrothermaux marins ont permis de dire qu'ils réunissaient les conditions favorables à l'apparition des premières formes de vie car des concentrations…
(more)
▼ Les découvertes de systèmes hydrothermaux marins ont permis de dire qu'ils réunissaient les conditions favorables à l'apparition des premières formes de vie car des concentrations appréciables en N2, CO2, H2S, CH4, C2H6 et C3H8 ainsi que des quantités détectables (10-9 mol) de n-alcanes de poids moléculaire élevé (C16-C29) ont été mesurées dans les fluides hydrothermaux de la ride médio-Atlantique. Les premières formes de vie étaient sans doute des êtres microbiens simples et unicellulaires qui ont pu trouver dans les composés organiques l'énergie nécessaire à leur évolution. Les systèmes hydrothermaux marins peuvent avoir constitués un environnement favorable à l'apparition de la vie car ces systèmes sont caractérisés par des fumeurs noirs et des fumeurs blancs avec un écosystème indépendant de l'énergie solaire où vivent les organismes les plus primitifs trouvés dans les environnements actuels, les hyperthermophiles. Ces arguments sont très importants en ce qui concerne les conditions qui régnaient à l'Archéen. Les systèmes hydrothermaux Archéens sont les seuls environnements où la vie primitive a pu être protégée des impacts des météorites et de la vaporisation partielle de l'océan. Ces systèmes sont compatibles avec l'origine et l'évolution de la vie. Les études expérimentales, sur la synthèse et la stabilité des composés prébiotiques dans des conditions hydrothermales sont couplées aux études théoriques en thermodynamique permises par les travaux de mesure expérimentales. L'origine abiogéniques des composés organiques azotés dans les conditions hydrothermales est primordiale dans l'histoire de la Terre
Hydrothermal Systems discovery involve it gather favorable conditions to act for the appearing of the first living shape, because significant concentrations in N2, CO2, H2S, CH4, C2H6 and C3H8 and detectable quantities (10-9 mol) of heavy weights n-alcanes (C19-C29) were measured in hydrothermal fluids of the mid-Atlantic ridge. The first living shape were without no doubt simple or unicellular microbes being which finding in organic compounds the satisfying energize for their evolution. Hydrothermal systems could have constitute a favorable environment for the appearing of life because these systems are characterized by black smokers and white smokers with an ecosystems independent of solar energize where the most primitives organisms live, found in actual environments, the hyperthermophiles. These arguments are very important concerning the conditions ruling in Archean. The hydrothermal systems of Archean were the only environment where the primitive life was protect of meteoritic impact and partial vaporization of the ocean. These systems are compatible with origin and evolution of life. The experimental study, on the synthesis and stability of prebiotic compounds in hydrothermal conditions are gathered with thermodynamic studies permit by the works of experimental measures. Abiogenic origin of nitrogen organic compounds in hydrothermal conditions is primordial in the history of the Earth
Advisors/Committee Members: Nguyen-Trung, Chinh (thesis director).
Subjects/Keywords: Fluides hydrothermaux; Archéen; Vie primitive; Origine; Thermodynamique; Hydrothermal fluids; Archean; Primitive life; Origin; Thermodynamic
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APA (6th Edition):
Franiatte, M. (2011). Etude théorique et expérimentale de la biogenèse des systèmes hydrothermaux marins : une contribution à la recherche sur l'origine de la vie : Theorical and experimental study of submarine hydrothermal fluids Implications for origin of life. (Doctoral Dissertation). Université Henri Poincaré – Nancy I. Retrieved from http://www.theses.fr/2011NAN10054
Chicago Manual of Style (16th Edition):
Franiatte, Michael. “Etude théorique et expérimentale de la biogenèse des systèmes hydrothermaux marins : une contribution à la recherche sur l'origine de la vie : Theorical and experimental study of submarine hydrothermal fluids Implications for origin of life.” 2011. Doctoral Dissertation, Université Henri Poincaré – Nancy I. Accessed January 26, 2021.
http://www.theses.fr/2011NAN10054.
MLA Handbook (7th Edition):
Franiatte, Michael. “Etude théorique et expérimentale de la biogenèse des systèmes hydrothermaux marins : une contribution à la recherche sur l'origine de la vie : Theorical and experimental study of submarine hydrothermal fluids Implications for origin of life.” 2011. Web. 26 Jan 2021.
Vancouver:
Franiatte M. Etude théorique et expérimentale de la biogenèse des systèmes hydrothermaux marins : une contribution à la recherche sur l'origine de la vie : Theorical and experimental study of submarine hydrothermal fluids Implications for origin of life. [Internet] [Doctoral dissertation]. Université Henri Poincaré – Nancy I; 2011. [cited 2021 Jan 26].
Available from: http://www.theses.fr/2011NAN10054.
Council of Science Editors:
Franiatte M. Etude théorique et expérimentale de la biogenèse des systèmes hydrothermaux marins : une contribution à la recherche sur l'origine de la vie : Theorical and experimental study of submarine hydrothermal fluids Implications for origin of life. [Doctoral Dissertation]. Université Henri Poincaré – Nancy I; 2011. Available from: http://www.theses.fr/2011NAN10054
Harvard University
26.
Ranjan, Sukrit.
The UV Environment for Prebiotic Chemistry: Connecting Origin-of-Life Scenarios to Planetary Environments.
Degree: PhD, 2017, Harvard University
URL: http://nrs.harvard.edu/urn-3:HUL.InstRepos:41142052
► Recent laboratory studies of prebiotic chemistry (chemistry relevant to the origin of life) are revolutionizing our understanding of the origin of life (abiogenesis) on Earth…
(more)
▼ Recent laboratory studies of prebiotic chemistry (chemistry relevant to the
origin of
life) are revolutionizing our understanding of the
origin of
life (abiogenesis) on Earth just as telescopes capable of searching for
life elsewhere are coming online. This thesis sits at the intersection of these revolutions. I examine prebiotic chemical pathways postulated to be relevant to the
origin of
life and identify the environmental conditions they require to function. I compare these environmental requirements to what was available on Earth and other planets, and use the comparison to 1) improve studies of the
origin of
life on Earth and 2) explore the implications for the inhabitability of other worlds.
Multiple lines of evidence suggest UV light may have played a critical role in the synthesis of molecules relevant to abiogenesis (prebiotic chemistry), such as RNA. I show that UV light interacts with prebiotic chemistry in ways that may be sensitive to the spectral shape and overall amplitude of irradiation. I use radiative transfer models to constrain the UV environment on early Earth (3.9 Ga). I find that the surface UV is insensitive to much of the considerable uncertainty in the atmospheric state, enabling me to constrain the UV environment for prebiotic chemistry on early Earth. Some authors have suggested Mars as a venue for prebiotic chemistry. Therefore, I explore plausible UV spectral fluences on Mars at 3.9 Ga. I find that the early Martian UV environment is comparable to Earth’s under conventional assumptions about the atmosphere. However, if the atmosphere was dusty or SO2 levels were high, UV fluence would have been strongly suppressed. Intriguingly, despite overall attenuation of UV fluence, SO2 preferentially attenuates destructive FUV radiation over prebiotically-useful NUV radiation, meaning high-SO2 epochs may have been more clement for the
origin of
life. Better measurements of the spectral dependence of prebiotic photoprocesses are required to constrain this hypothesis. Finally, I calculate the UV fluence on planets orbiting M-dwarfs. I find that UV irradiation on such planets is low compared to Earth. Laboratory studies are required to understand whether prebiotic processes that worked on Earth can function on low-UV M-dwarf planets.
In addition to UV light, the most promising pathways for the prebiotic synthesis of RNA require reduced sulfidic anions. I show that prebiotically-relevant levels of such anions derived from volcanically-outgassed SO2 should be robustly available on early Earth, and that episodes of high volcanism may be especially clement for these prebiotic pathways. However, H2S-derived anions are much less common, and prebiotic chemistry which invokes them must rely on alternate, localized sources.
My work 1) provides initial conditions for laboratory studies of prebiotic chemistry, 2) constrains the inhabitability of Mars and planets orbiting M-dwarfs, and 3) demonstrates the need for laboratory studies to characterize the sensitivity of putative prebiotic chemistry to environmental…
Advisors/Committee Members: Sasselov, Dimitar S. (advisor), Catling, David C. (committee member), Elvis, Martin S. (committee member), Szostak, Jack W. (committee member).
Subjects/Keywords: Radiative Transfer; Origin of Life; Planetary Environments; UV Radiation; Prebiotic Chemistry; Astrobiology; M-dwarfs; Sulfur
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APA (6th Edition):
Ranjan, S. (2017). The UV Environment for Prebiotic Chemistry: Connecting Origin-of-Life Scenarios to Planetary Environments. (Doctoral Dissertation). Harvard University. Retrieved from http://nrs.harvard.edu/urn-3:HUL.InstRepos:41142052
Chicago Manual of Style (16th Edition):
Ranjan, Sukrit. “The UV Environment for Prebiotic Chemistry: Connecting Origin-of-Life Scenarios to Planetary Environments.” 2017. Doctoral Dissertation, Harvard University. Accessed January 26, 2021.
http://nrs.harvard.edu/urn-3:HUL.InstRepos:41142052.
MLA Handbook (7th Edition):
Ranjan, Sukrit. “The UV Environment for Prebiotic Chemistry: Connecting Origin-of-Life Scenarios to Planetary Environments.” 2017. Web. 26 Jan 2021.
Vancouver:
Ranjan S. The UV Environment for Prebiotic Chemistry: Connecting Origin-of-Life Scenarios to Planetary Environments. [Internet] [Doctoral dissertation]. Harvard University; 2017. [cited 2021 Jan 26].
Available from: http://nrs.harvard.edu/urn-3:HUL.InstRepos:41142052.
Council of Science Editors:
Ranjan S. The UV Environment for Prebiotic Chemistry: Connecting Origin-of-Life Scenarios to Planetary Environments. [Doctoral Dissertation]. Harvard University; 2017. Available from: http://nrs.harvard.edu/urn-3:HUL.InstRepos:41142052
Brigham Young University
27.
Strait, James G.
The Relationship Between Attachment Related Family-of-Origin Experiences and Sexual Satisfaction in Married Couples.
Degree: MS, 2010, Brigham Young University
URL: https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=3268&context=etd
► This study of married couples examined the relationship between perceptions of attachment related family-of-origin experiences and sexual satisfaction directly and when mediated by marital quality.…
(more)
▼ This study of married couples examined the relationship between perceptions of attachment related family-of-origin experiences and sexual satisfaction directly and when mediated by marital quality. The sample consisted of 3,953 married couples who responded to the RELATionship Evaluation (RELATE). The nested model showed that more positive overall family-of-origin experiences and parent-child relationships were related to higher sexual satisfaction. When adding marital quality as a mediator, overall family-of-origin experience and the parent-child relationship were predictive of higher sexual satisfaction when mediated by marital quality but removed most direct effects to sexual satisfaction. There was a strong positive relationship between marital quality and sexual satisfaction. No major gender differences emerged and more than 50% of the variance in sexual satisfaction was explained by the full model for both males and females. Results suggest that family-of-origin experiences play an important role in the sexual satisfaction of married couples, especially when mediated by marital quality, and should be considered in treatment, education, and research.
Subjects/Keywords: family-of-origin; marital quality; sexual satisfaction; attachment; Family, Life Course, and Society
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APA (6th Edition):
Strait, J. G. (2010). The Relationship Between Attachment Related Family-of-Origin Experiences and Sexual Satisfaction in Married Couples. (Masters Thesis). Brigham Young University. Retrieved from https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=3268&context=etd
Chicago Manual of Style (16th Edition):
Strait, James G. “The Relationship Between Attachment Related Family-of-Origin Experiences and Sexual Satisfaction in Married Couples.” 2010. Masters Thesis, Brigham Young University. Accessed January 26, 2021.
https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=3268&context=etd.
MLA Handbook (7th Edition):
Strait, James G. “The Relationship Between Attachment Related Family-of-Origin Experiences and Sexual Satisfaction in Married Couples.” 2010. Web. 26 Jan 2021.
Vancouver:
Strait JG. The Relationship Between Attachment Related Family-of-Origin Experiences and Sexual Satisfaction in Married Couples. [Internet] [Masters thesis]. Brigham Young University; 2010. [cited 2021 Jan 26].
Available from: https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=3268&context=etd.
Council of Science Editors:
Strait JG. The Relationship Between Attachment Related Family-of-Origin Experiences and Sexual Satisfaction in Married Couples. [Masters Thesis]. Brigham Young University; 2010. Available from: https://scholarsarchive.byu.edu/cgi/viewcontent.cgi?article=3268&context=etd
Georgia Tech
28.
McKee, Aaron D.
Prebiotic chemistry on mineral surfaces: Proto-oligopeptide formation on silica and other substrates within depsipeptide forming systems.
Degree: PhD, Chemistry and Biochemistry, 2019, Georgia Tech
URL: http://hdl.handle.net/1853/62328
► The chemical origins of life on Earth and perhaps elsewhere in the universe is not utterly unknowable, though the subject is incredibly complex. To endeavor…
(more)
▼ The chemical origins of
life on Earth and perhaps elsewhere in the universe is not utterly unknowable, though the
subject is incredibly complex. To endeavor to understand what events brought about
life on early-Earth nearly 4 billion years ago,
life itself must be broken down into its major processes, which themselves are constructed from increasingly simple and ordinary sub-units, and eventually, examined to describe the building blocks of
life and how they might assemble. The presence of amino acids on extra-terrestrial bodies and in prebiotic simulation experiments suggests the plausibility of their existence on early Earth. In contrast to extant biological protein production, abiotic polypeptide formation presents several challenges, such as the thermodynamically disfavored condensation of non-activated amino acids in aqueous solution. Recent work has introduced α-hydroxy acids, a class of molecules found alongside amino acids in prebiotic contexts, into peptide forming systems. This has been shown as a robust route towards proto-polypeptides, producing long mixed-acid oligomers, referred to as depsipeptides. In pursuit of realistic model prebiotic environments, mineral-molecule interactions must be considered, and may facilitate new chemical pathways at interfacial regions. Presented in this thesis is a demonstration that the inclusion of silica and other minerals in hydroxy-acid/amino-acid and related reactions effects the composition of oligomers, resulting in amino acid enrichment relative to a substrate-absent controls. Evidence of surface ester formation suggests that the same ester aminolysis mechanism that proceeds in a homogeneous condition is also able to proceed on the substrate surface as silyl-ester aminolysis, indicating that silica is directly involved in the oligomer growth process and departs from previous studies of mineral catalyzed peptide formation on metal oxides. If depsipeptides are model proto-polypeptides, then surface functionalization of minerals with simple HAs might provide catalytic pathways useful for unraveling plausible routes to the production of complex molecules under early-Earth conditions or on extraterrestrial bodies.
Advisors/Committee Members: Orlando, Thomas M. (advisor), Hud, Nicholas V. (advisor), Liotta, Charles L. (advisor), Fernández, Facundo M. (advisor), Wray, James J. (advisor).
Subjects/Keywords: Chemical origin of life; Prebiotic chemistry; Silica; Amino acids; Depsipeptides; Oligopeptides; Astrobiology; Surface science; Glycine
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APA ·
Chicago ·
MLA ·
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CSE |
Export
to Zotero / EndNote / Reference
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APA (6th Edition):
McKee, A. D. (2019). Prebiotic chemistry on mineral surfaces: Proto-oligopeptide formation on silica and other substrates within depsipeptide forming systems. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/62328
Chicago Manual of Style (16th Edition):
McKee, Aaron D. “Prebiotic chemistry on mineral surfaces: Proto-oligopeptide formation on silica and other substrates within depsipeptide forming systems.” 2019. Doctoral Dissertation, Georgia Tech. Accessed January 26, 2021.
http://hdl.handle.net/1853/62328.
MLA Handbook (7th Edition):
McKee, Aaron D. “Prebiotic chemistry on mineral surfaces: Proto-oligopeptide formation on silica and other substrates within depsipeptide forming systems.” 2019. Web. 26 Jan 2021.
Vancouver:
McKee AD. Prebiotic chemistry on mineral surfaces: Proto-oligopeptide formation on silica and other substrates within depsipeptide forming systems. [Internet] [Doctoral dissertation]. Georgia Tech; 2019. [cited 2021 Jan 26].
Available from: http://hdl.handle.net/1853/62328.
Council of Science Editors:
McKee AD. Prebiotic chemistry on mineral surfaces: Proto-oligopeptide formation on silica and other substrates within depsipeptide forming systems. [Doctoral Dissertation]. Georgia Tech; 2019. Available from: http://hdl.handle.net/1853/62328
Arizona State University
29.
Mathis, Nicholas.
On the Origin of the Living State.
Degree: Physics, 2018, Arizona State University
URL: http://repository.asu.edu/items/50446
► The origin of Life on Earth is the greatest unsolved mystery in the history of science. In spite of progress in almost every scientific endeavor,…
(more)
▼ The origin of Life on Earth is the greatest unsolved
mystery in the history of science. In spite of progress in almost
every scientific endeavor, we still have no clear theory, model, or
framework to understand the processes that led to the emergence of
life on Earth. Understanding such a processes would provide key
insights into astrobiology, planetary science, geochemistry,
evolutionary biology, physics, and philosophy. To date, most
research on the origin of life has focused on characterizing and
synthesizing the molecular building blocks of living systems. This
bottom-up approach assumes that living systems are characterized by
their component parts, however many of the essential features of
life are system level properties which only manifest in the
collective behavior of many components. In order to make progress
towards solving the origin of life new modeling techniques are
needed. In this dissertation I review historical approaches to
modeling the origin of life. I proceed to elaborate on new
approaches to understanding biology that are derived from
statistical physics and prioritize the collective properties of
living systems rather than the component parts. In order to study
these collective properties of living systems, I develop
computational models of chemical systems. Using these computational
models I characterize several system level processes which have
important implications for understanding the origin of life on
Earth. First, I investigate a model of molecular replicators and
demonstrate the existence of a phase transition which occurs
dynamically in replicating systems. I characterize the properties
of the phase transition and argue that living systems can be
understood as a non-equilibrium state of matter with unique
dynamical properties. Then I develop a model of molecular assembly
based on a ribonucleic acid (RNA) system, which has been
characterized in laboratory experiments. Using this model I
demonstrate how the energetic properties of hydrogen bonding
dictate the population level dynamics of that RNA system. Finally I
return to a model of replication in which replicators are strongly
coupled to their environment. I demonstrate that this dynamic
coupling results in qualitatively different evolutionary dynamics
than those expected in static environments. A key difference is
that when environmental coupling is included, evolutionary
processes do not select a single replicating species but rather a
dynamically stable community which consists of many species.
Finally, I conclude with a discussion of how these computational
models can inform future research on the origins of
life.
Subjects/Keywords: Physics; Computational physics; Biology; Astrobiology; Complex Systems; Origin Of Life; Prebiotic Chemistry; Systems Chemistry
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APA (6th Edition):
Mathis, N. (2018). On the Origin of the Living State. (Doctoral Dissertation). Arizona State University. Retrieved from http://repository.asu.edu/items/50446
Chicago Manual of Style (16th Edition):
Mathis, Nicholas. “On the Origin of the Living State.” 2018. Doctoral Dissertation, Arizona State University. Accessed January 26, 2021.
http://repository.asu.edu/items/50446.
MLA Handbook (7th Edition):
Mathis, Nicholas. “On the Origin of the Living State.” 2018. Web. 26 Jan 2021.
Vancouver:
Mathis N. On the Origin of the Living State. [Internet] [Doctoral dissertation]. Arizona State University; 2018. [cited 2021 Jan 26].
Available from: http://repository.asu.edu/items/50446.
Council of Science Editors:
Mathis N. On the Origin of the Living State. [Doctoral Dissertation]. Arizona State University; 2018. Available from: http://repository.asu.edu/items/50446
University of Kentucky
30.
Shalash, Fatimah.
SIBLING CONFLICT RESOLUTION STYLES AND MARITAL CONFLICT RESOLUTION STYLES.
Degree: 2011, University of Kentucky
URL: https://uknowledge.uky.edu/gradschool_theses/109
► This study used qualitative methods to examine if there was a connection between conflict resolution styles used with siblings in adolescence and conflict resolution styles…
(more)
▼ This study used qualitative methods to examine if there was a connection between conflict resolution styles used with siblings in adolescence and conflict resolution styles utilized in current romantic committed relationships. The Conflict Resolution Behavior Questionnaire (Reese-Weber, & Bartle-Haring, 2003) and Gottman‟s (1994a, 1994b) couple-conflict types as adapted by Holman and Jarvis (2003) were administered to 144 participants through an online questionnaire. Analysis of the CRBQ using a multiple regression indicated participant‟s self-rating of compromise, attack, and avoidant conflict resolution styles used with siblings when an adolescent predicted current self-ratings of compromise, attack, and avoidant conflict resolution styles utilized in current romantic relationships.
Subjects/Keywords: Conflict resolution; siblings; marriage; social learning theory; family of origin; Family, Life Course, and Society
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APA ·
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APA (6th Edition):
Shalash, F. (2011). SIBLING CONFLICT RESOLUTION STYLES AND MARITAL CONFLICT RESOLUTION STYLES. (Masters Thesis). University of Kentucky. Retrieved from https://uknowledge.uky.edu/gradschool_theses/109
Chicago Manual of Style (16th Edition):
Shalash, Fatimah. “SIBLING CONFLICT RESOLUTION STYLES AND MARITAL CONFLICT RESOLUTION STYLES.” 2011. Masters Thesis, University of Kentucky. Accessed January 26, 2021.
https://uknowledge.uky.edu/gradschool_theses/109.
MLA Handbook (7th Edition):
Shalash, Fatimah. “SIBLING CONFLICT RESOLUTION STYLES AND MARITAL CONFLICT RESOLUTION STYLES.” 2011. Web. 26 Jan 2021.
Vancouver:
Shalash F. SIBLING CONFLICT RESOLUTION STYLES AND MARITAL CONFLICT RESOLUTION STYLES. [Internet] [Masters thesis]. University of Kentucky; 2011. [cited 2021 Jan 26].
Available from: https://uknowledge.uky.edu/gradschool_theses/109.
Council of Science Editors:
Shalash F. SIBLING CONFLICT RESOLUTION STYLES AND MARITAL CONFLICT RESOLUTION STYLES. [Masters Thesis]. University of Kentucky; 2011. Available from: https://uknowledge.uky.edu/gradschool_theses/109
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Open Access Theses and Dissertations
