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Full-Text Articles in Physical Sciences and Mathematics

A Realization Of Modernity: Case Studies In Connectivity And Time, Mari Gorman Sep 2017

A Realization Of Modernity: Case Studies In Connectivity And Time, Mari Gorman

Dissertations, Theses, and Capstone Projects

My stated goal in applying to The Graduate Center was to explore my previous research in diverse fields of study. This research, the result of a formal investigation of acting, was and still is centrally focused on the subject of relationship itself, relationships being what actors create. In pursuit of a greater understanding of the essential nature of relationship in practical terms, a self-organizing complex system that constitutes universal relationship was unexpectedly discovered. As such, this system has been shown to offer solutions to many outstanding problems in diverse areas of study. The Liberal Studies program track, Approaches to Modernity …


Computational Investigation Of The Pore Formation Mechanism Of Beta-Hairpin Antimicrobial Peptides, Richard Lipkin Sep 2017

Computational Investigation Of The Pore Formation Mechanism Of Beta-Hairpin Antimicrobial Peptides, Richard Lipkin

Dissertations, Theses, and Capstone Projects

β-hairpin antimicrobial peptides (AMPs) are small, usually cationic peptides that provide innate biological defenses against multiple agents. They have been proposed as the basis for novel antibiotics, but their pore formation has not been directly observed on a molecular level. We review previous computational studies of peptide-induced membrane pore formation and report several new molecular dynamics simulations of β-hairpin AMPs to elucidate their pore formation mechanism. We simulated β-barrels of various AMPs in anionic implicit membranes, finding that most of the AMPs’ β-barrels were not as stable as those of protegrin. We also performed an optimization study of protegrin β-barrels …


Lichen Conservation In Eastern North America: Population Genomics, Climate Change, And Translocations, Jessica Allen Jun 2017

Lichen Conservation In Eastern North America: Population Genomics, Climate Change, And Translocations, Jessica Allen

Dissertations, Theses, and Capstone Projects

Conservation biology is a scientific discipline that draws on methods from diverse fields to address specific conservation concerns and inform conservation actions. This field is overwhelmingly focused on charismatic animals and vascular plants, often ignoring other diverse and ecologically important groups. This trend is slowly changing in some ways; for example, increasing number of fungal species are being added to the IUCN Red-List. However, a strong taxonomic bias still exists. Here I contribute four research chapters to further the conservation of lichens, one group of frequently overlooked organisms. I address specific conservation concerns in eastern North America using modern methods. …


Naturally-Derived Molecular Ensembles In Medicine, Materials Science And Evolutionary Biology: An Interdisciplinary Study, Silvio Panettieri Jun 2017

Naturally-Derived Molecular Ensembles In Medicine, Materials Science And Evolutionary Biology: An Interdisciplinary Study, Silvio Panettieri

Dissertations, Theses, and Capstone Projects

The first chapter will introduce the work carried out in collaboration with the Govind laboratory at CCNY. Our quest was set forth to investigate the intimate relationship lying between chronic inflammation and tumor development. For at least the last fifteen years much research has been conducted on this topic; yet, the level of complexity arising from exceedingly interwoven biochemical pathways in mammals has resulted in slow advancements in this field. This is why we resorted to a simple yet powerful immunogenetic model organism, the fruit fly Drosophila melanogaster, in combination with the administration of the most common anti-inflammatory drug, …


Impact Of Urbanization On Temperature Variation In Big Cities: Measuring Health Risk While Targeting Vulnerable Population, Maryam E. Karimi Feb 2017

Impact Of Urbanization On Temperature Variation In Big Cities: Measuring Health Risk While Targeting Vulnerable Population, Maryam E. Karimi

Dissertations, Theses, and Capstone Projects

Densely populated cities are experiencing Urban Heat Island (UHI) effects and localized hotspots. Cities, such as New York can form heat islands all year round. This is primarily due to land surface modifications, radiative trapping in urban canyons and lack of cooling through evapotranspiration caused by displaced trees and vegetation. UHI refers to an increase in air and surface temperature in cities compared to surrounding suburban and rural areas. Large scale environmental forcing can cause subdivisions of UHI throughout a city. The combined of environmental forcing effects lead to the formation of hot pockets within the cities at micro-scale. The …


Enzymatically Active Microspheres For Self-Propelled Colloidal Engines, Jungeun Park Jan 2017

Enzymatically Active Microspheres For Self-Propelled Colloidal Engines, Jungeun Park

Dissertations and Theses

Micro- and nano-motors have attracted numerous attentions from various scientific areas due to their potential applications. Most studies on self-propelled colloidal engines have exploited catalytic decomposition of hydrogen peroxide to drive the motor. Since the hydrogen peroxide is caustic, it is not suitable to use in biological applications, encouraging people to develop “greener” fuels. The aim of this research is to study a new transduction mechanism for self-propulsion not tied to hydrogen peroxide, and which can in particular be used with biological molecules as fuels. In this study, we focus on making particles with enzymatic activity which can effectively decompose …


Flight Of The Freshwater Fish, Michael H. Wilson Dec 2016

Flight Of The Freshwater Fish, Michael H. Wilson

Capstones

Michael H. Wilson

Capstone Abstract

December 27, 2016

Flight of the Freshwater Fish

The Hudson River provides for millions of people as a path for commercial and private transportation, a source of food and energy, and perhaps most importantly for many living in the tri-state area as a destination for recreation and relaxation. The most overlooked feature of the river is how the wildlife shows clear signs of a changing climate and rapid environmental response to the impacts of global warming on the river.

Entire populations of fish species in the lower Hudson have been forced to leave the river …


Specific Binding Affinity Of The Non-Catalytic Domain Of Eukaryotic Like Type Ib Topoisomerase Of Vaccinia Virus, Benjamin R. Reed Sep 2016

Specific Binding Affinity Of The Non-Catalytic Domain Of Eukaryotic Like Type Ib Topoisomerase Of Vaccinia Virus, Benjamin R. Reed

Dissertations, Theses, and Capstone Projects

Topoisomerases are ubiquitous proteins that alter supercoiling in double stranded DNA (dsDNA) during transcription and replication and. vaccinia and the closely related poxvirus variola virus, at 314 amino acids in length, encode the smallest of the type I topoisomerases(TopIB). TopIB is a two domain protein that recognizes the sequence 5’-T/CCCTT, cleaves at the 3’-end and relaxes supercoiling through rotation. The C-terminal domain (CTD) alone contains the catalytic activity and specificity. Deletion of the N-terminal domain results in a greatly reduced rate of relaxation and rapid dissociation. Biochemical data suggests that the N-terminal domain (NTD) is important for pre-cleavage binding and …


Metabolic Profiling And Polymer Formation Of Gene Silenced Potato Periderms, Qing Cai Sep 2016

Metabolic Profiling And Polymer Formation Of Gene Silenced Potato Periderms, Qing Cai

Dissertations, Theses, and Capstone Projects

Suberin is a biopolyester constituent of specialized plant periderm tissues formed within the phellem cell walls. Suberin and waxes of the periderm layer act to prevent water diffusion, mechanical breakdown and pathogenic invasion in plants. Ferulic esters, ω-hydroxyacids and α,ω-fatty diacids are considered to be the most important linkage between aliphatic and aromatic suberin domains and also linked with cell-wall polysaccharides. The potato gene FHT (fatty ω- hydroxyacid/fatty alcohol hydroxycinnamoyl transferase) esterifies ferulic acid to suberin. Diminished levels of feruloyl transferase activity have been associated with lowered amounts of feruloyl esters of fatty acids in both suberin-associated waxes and suberin …


Computerized Classification Of Surface Spikes In Three-Dimensional Electron Microscopic Reconstructions Of Viruses, Younes Benkarroum Sep 2016

Computerized Classification Of Surface Spikes In Three-Dimensional Electron Microscopic Reconstructions Of Viruses, Younes Benkarroum

Dissertations, Theses, and Capstone Projects

The purpose of this research is to develop computer techniques for improved three-dimensional (3D) reconstruction of viruses from electron microscopic images of them and for the subsequent improved classification of the surface spikes in the resulting reconstruction. The broader impact of such work is the following.

Influenza is an infectious disease caused by rapidly-changing viruses that appear seasonally in the human population. New strains of influenza viruses appear every year, with the potential to cause a serious global pandemic. Two kinds of spikes – hemagglutinin (HA) and neuraminidase (NA) – decorate the surface of the virus particles and these proteins …


Metabolic Profiling Of Genetically Modified Potato Periderm Tissues, Liqing Jin Sep 2016

Metabolic Profiling Of Genetically Modified Potato Periderm Tissues, Liqing Jin

Dissertations, Theses, and Capstone Projects

Potato tubers are protected from dehydration and pathogens by a covering peel (periderm) impregnated with suberin, a complex cross-linked biopolymer that contains both polyaliphatic and lignin-like aromatic domains. Current models describing the macromolecular structure of suberin assume that ferulic acid cross-links both domains as it may form carboxyl ester bonds with aliphatic monomers and non-ester radical-coupled bonds with phenolics. Ferulic acid also links by ester bonds to glycans and acts in cross-linking polysaccharides and lignin. Fatty alcohol/ω-hydroxyacid hydroxycinnamoyl transferase (FHT) is a BADH acyltransferase responsible for the synthesis of akyl-ferulates that is necessary for suberin biosynthesis. Periderm from FHT-RNAi …


Interaction Of Spliceosomal U2 Snrnp Protein P14 With Its Branch Site Rna Target, William Perea Vargas Jun 2016

Interaction Of Spliceosomal U2 Snrnp Protein P14 With Its Branch Site Rna Target, William Perea Vargas

Dissertations, Theses, and Capstone Projects

Newly transcribed precursor messenger RNA (pre-mRNA) molecules contain coding sequences (exons) interspersed with non-coding intervening sequences (introns). These introns must be removed in order to generate a continuous coding sequence prior to translation of the message into protein. The mechanism through which these introns are removed is known as pre-mRNA splicing, a two-step reaction catalyzed be a large macromolecular machine, the spliceosome, located in the nucleus of eukaryotic cells. The spliceosome is a protein-directed ribozyme composed of small nuclear RNAs (snRNA) and hundreds of proteins that assemble in a very dynamic process. One of these snRNAs, the U2 snRNA, is …


Exploring Data Mining Techniques For Tree Species Classification Using Co-Registered Lidar And Hyperspectral Data, Julia K. Marrs May 2016

Exploring Data Mining Techniques For Tree Species Classification Using Co-Registered Lidar And Hyperspectral Data, Julia K. Marrs

Theses and Dissertations

NASA Goddard’s LiDAR, Hyperspectral, and Thermal imager provides co-registered remote sensing data on experimental forests. Data mining methods were used to achieve a final tree species classification accuracy of 68% using a combined LiDAR and hyperspectral dataset, and show promise for addressing deforestation and carbon sequestration on a species-specific level.


Revised Distributional Estimates For The Recently Discovered Olinguito (Bassaricyon Neblina), Using Museum And Science Records, Beth E. Gerstner Jan 2016

Revised Distributional Estimates For The Recently Discovered Olinguito (Bassaricyon Neblina), Using Museum And Science Records, Beth E. Gerstner

Dissertations and Theses

In the context of global change, a necessary first step for the conservation of species is gaining a good understanding of their distributional limits. This is especially important for biodiversity hotspots with high endemism such as the Northern Andes. The olinguito (Procyonidae: Bassaricyon neblina) is a recently described, medium-sized carnivoran found in Northern Andean cloud forests. A preliminary distributional model was published along with the original description, and I here provide revised distributional estimates using updated locality records and more current ENM methods. I build ecological niche models in Maxent using occurrence data (georeferenced museum records and citizen science-derived photo-vouchers) …


Biophysical Characterization Of A De Novo Elastin, Kelly Nicole Greenland Sep 2015

Biophysical Characterization Of A De Novo Elastin, Kelly Nicole Greenland

Dissertations, Theses, and Capstone Projects

Natural human elastin is found in tissue such as the lungs, arteries, and skin. This protein is formed at birth with no mechanism present to repair or supplement the initial quantity formed. As a result, the functionality and durability of elastin's elasticity is critically important. To date, the mechanics of this ability to stretch and recoil is not fully understood. This study utilizes de novo protein design to create a small library of simplistic versions of elastin-like proteins, demonstrate the elastin-like proteins, maintain elastin's functionality, and inquire into its structure using solution nuclear magnetic resonance (NMR).

Elastin is formed from …


Climate-Smart Agriculture: Farmer's Bane Or Boon?, Jeeva Mary Jacob May 2015

Climate-Smart Agriculture: Farmer's Bane Or Boon?, Jeeva Mary Jacob

Dissertations, Theses, and Capstone Projects

Climate-Smart Agriculture (CSA) is one of the solutions that simultaneously address the issues of food security, climate change and agricultural productivity. It has been gaining momentum in the last five years among policy circles and development organizations have prioritized CSA interventions in developing countries around the world. In this paper, CSA interventions are examined from the small farmer's perspective and the purpose of this paper is to find out whether Climate-Smart Agriculture truly empowers the farmer in the face of climate change. Such a study emerged from the fact that in the past, agricultural interventions like the Green Revolution promised …


De Novo Design And Engineering Of Functional Metal And Porphyrin-Binding Protein Domains, Bernard Howard Everson Feb 2015

De Novo Design And Engineering Of Functional Metal And Porphyrin-Binding Protein Domains, Bernard Howard Everson

Dissertations, Theses, and Capstone Projects

In this work, I describe an approach to the rational, iterative design and characterization of two functional cofactor-binding protein domains. First, a hybrid computational/experimental method was developed with the aim of algorithmically generating a suite of porphyrin-binding protein sequences with minimal mutual sequence information. This method was explored by generating libraries of sequences, which were then expressed and evaluated for function. One successful sequence is shown to bind a variety of porphyrin-like cofactors, and exhibits light- activated electron transfer in mixed hemin:chlorin e6 and hemin:Zn(II)-protoporphyrin IX complexes. These results imply that many sophisticated functions such as cofactor binding and electron …


Development Of Cell-Active Inhibitors And Activity-Based Probe Of Cysteine Cathepsins, Dibyendu Dana Oct 2014

Development Of Cell-Active Inhibitors And Activity-Based Probe Of Cysteine Cathepsins, Dibyendu Dana

Dissertations, Theses, and Capstone Projects

Cysteine cathepsins are an important class of enzymes that coordinate a variety of important cellular processes, and are implicated in various types of human diseases. Still however, many of their cellular function remain poorly understood. Chemical biology approaches employing small molecules can be utilized for this purpose. Unfortunately small molecule probes that are cell-permeable and non-peptidyl in nature are scarcely available.

In this work, first a library of sulfonyloxiranes is synthesized. From this library, 2-(2-ethylphenylsulfonyl)oxirane is identified as a selective inhibitor of cysteine cathepsins. Cell-based study reveals that 2-(2-ethylphenylsulfonyl)oxirane is a cell-permeable, covalent, and irreversible inhibitor of cathepsin B with …


Paleoecology Of Late Cretaceous Methane Cold-Seeps Of The Pierre Shale, South Dakota, Kimberly Cynthia Handle Oct 2014

Paleoecology Of Late Cretaceous Methane Cold-Seeps Of The Pierre Shale, South Dakota, Kimberly Cynthia Handle

Dissertations, Theses, and Capstone Projects

Most investigations of ancient methane seeps focus on either the geologic or paleontological aspects of these extreme environments. In contrast, this thesis encompasses both disciplines to evaluate the paleoecology of these systems with greater detail than previously published either within the Western Interior Basin or elsewhere. This thesis addresses the following questions: 1) Are the changes in mineralogy of a seep discernable and predictable as a seep shifts from a clay-based environment to a carbonate-based environment? 2) What are the foundation organism(s) of Late Cretaceous methane cold-seeps? 3) Is there a correlation to the mineralogic changes and shifts in community …


Component Trees For The Exploration Of Macromolecular Structures In Biology, Lucas Oliveira Oct 2014

Component Trees For The Exploration Of Macromolecular Structures In Biology, Lucas Oliveira

Dissertations, Theses, and Capstone Projects

Understanding the three-dimensional structure of a macromolecular complex is essential for understanding its function. A component tree is a topological and geometric image descriptor that captures information regarding the structure of an image based on the connected components determined by different grayness thresholds. This dissertation presents a novel interactive framework for visual exploration of component trees of the density maps of macromolecular complexes, with the purpose of improved understanding of their structure. The interactive exploration of component trees together with a robust simplification methodology provide new insights in the study of macromolecular structures. An underlying mathematical theory is introduced and …


Interactions Of Eukaryotic Translation Initiation Factors And 3' Untranslated Region Of Barley Yellow Dwarf Virus Mrna During Protein Synthesis: A Study Of Equilibrium Binding, Kinetics And Thermodynamics, Bidisha Banerjee Jun 2014

Interactions Of Eukaryotic Translation Initiation Factors And 3' Untranslated Region Of Barley Yellow Dwarf Virus Mrna During Protein Synthesis: A Study Of Equilibrium Binding, Kinetics And Thermodynamics, Bidisha Banerjee

Dissertations, Theses, and Capstone Projects

Eukaryotic initiation factor (eIF) 4F binding to mRNA is the first committed step in cap-dependent protein synthesis. Barley Yellow Dwarf Virus (BYDV) employs a cap-independent mechanism of translation initiation which is mediated by a structural element BTE (BYDV translation element) located in the 3’ UTR of its mRNA. eIF4F bound the BTE and a translational inactive mutant with high affinity; thus questioning the role of eIF4F in translation of BYDV. To examine the effects of eIF4F in BYDV translation initiation, BTE mutants with widely different in vitro translation efficiencies ranging from 5-164% compared to WT were studied. Using fluorescence anisotropy …


Variation In Habitat Thresholds: An Analysis Of Minimum Habitat Requirements Of North American Breeding Birds, Yntze Van Der Hoek Jun 2014

Variation In Habitat Thresholds: An Analysis Of Minimum Habitat Requirements Of North American Breeding Birds, Yntze Van Der Hoek

Dissertations, Theses, and Capstone Projects

Many species show dramatic changes in population extinction or persistence probability at particular habitat amounts. These `extinction thresholds' could be translated to conservation targets, under the condition that we can derive generalities. I investigated the level of variation in landscape-level habitat thresholds for a suite of North American, forest-associated, breeding birds. Records from Breeding Bird Atlases and the availability of remotely-sensed land cover data allowed me to compare habitat thresholds for 25 species across the states of Massachusetts, Michigan, New York, Ohio, Pennsylvania, and Vermont. I show that variation in thresholds is considerable (Chapter II, III), as thresholds range from …


Conformational Features Of The Human U2-U6 Snrna Complex, Ravichandra Bachu Feb 2014

Conformational Features Of The Human U2-U6 Snrna Complex, Ravichandra Bachu

Dissertations, Theses, and Capstone Projects

The splicing of precursor messenger (pre-m) RNA, during which noncoding intervening sequences are excised and flanking coding regions ligated, is an integral reaction of gene expression. In eukaryotes, it is carried out by a dynamic RNA-protein complex called the spliceosome, in which five small nuclear (sn) RNA components are actively involved in recognition and chemical aspects of the process. A complex formed between U2 and U6 snRNAs is implicated in the chemistry of pre-mRNA splicing. The catalytic activity of the U2-U6 snRNA complex is dependent on the presence of Mg2+ ions, and the complex has been shown to have several …


An Ethnobotanical, Ecological And Lc-Ms-Based Chemometric Investigation Of Phaleria Nisidai, A Traditional Adaptogen Containing Diterpene Esters From Palau, Micronesia, Daniel Kulakowski Feb 2014

An Ethnobotanical, Ecological And Lc-Ms-Based Chemometric Investigation Of Phaleria Nisidai, A Traditional Adaptogen Containing Diterpene Esters From Palau, Micronesia, Daniel Kulakowski

Dissertations, Theses, and Capstone Projects

An ethnobotanical, ecological and LC-MS-based chemometric investigation of Phaleria nisidai, a traditional adaptogen containing diterpene esters from Palau, Micronesia

Palau is a country with a rich heritage of traditional medicine still being practiced. One of the most popular and respected remedies in Palau is a tea made from fresh leaves of Phaleria nisidai Kaneh. (Thymelaeaceae). Interviews conducted to determine the use of this plant revealed that it is employed non-specifically to treat a variety of general health concerns. Its use as a prophylactic to keep away sickness, as a 'system cleaner', as well as for strength and energy indicate …


An Experimental Investigation Into The Mechanisms Of Bacterial Evolution, Zhenmao Wan Feb 2014

An Experimental Investigation Into The Mechanisms Of Bacterial Evolution, Zhenmao Wan

Dissertations, Theses, and Capstone Projects

This thesis studies the two fundamental mechanisms of bacterial evolution — horizontal gene transfer and spontaneous mutation, in the bacterium Escherichia coli through novel experimental assays and mathematical simulations. First, I will develop a growth assay utilizing the quantitative polymerase chain reaction (qPCR) to provide real-time enumeration of genetic marker abundance within bacterial populations. Second, I will focus on horizontal gene transfer in E. coli occurring through a process called conjugation. By fitting the qPCR data to a resource limited, logistic growth model, I will obtain estimated values of several key parameters governing the dynamics of DNA transfer through conjugation …


Long-Term Warming And The Size And Phenology Of Long Island Sound Plankton, Edward Rice Feb 2014

Long-Term Warming And The Size And Phenology Of Long Island Sound Plankton, Edward Rice

Dissertations, Theses, and Capstone Projects

In coastal ecosystems with decades of eutrophication and other anthropogenic stressors, the impact of climate change on planktonic communities can be difficult to detect. A time-series of monthly surface water temperatures in the Central Basin of Long Island Sound (LIS) from the late 1940s until 2012 indicates a warming rate of 0.03°C per year, with recent summer temperatures increasing most consistently. During this warming trend, the proportion of chlorophyll produced by smaller phytoplankton and flagellates appears to be higher during warmer summer and fall months, enabling an increase in annual chlorophyll despite static nutrient levels. The phenology of phytoplankton and …


Analysis Of Dna Motifs In The Human Genome, Yupu Liang Feb 2014

Analysis Of Dna Motifs In The Human Genome, Yupu Liang

Dissertations, Theses, and Capstone Projects

DNA motifs include repeat elements, promoter elements and gene regulator elements, and play a critical role in the human genome. This thesis describes a genome-wide computational study on two groups of motifs: tandem repeats and core promoter elements.

Tandem repeats in DNA sequences are extremely relevant in biological phenomena and diagnostic tools. Computational programs that discover tandem repeats generate a huge volume of data, which can be difficult to decipher without further organization. A new method is presented here to organize and rank detected tandem repeats through clustering and classification. Our work presents multiple ways of expressing tandem repeats using …


Phylogeny And Population Genetics Of The Endangered Dwarf Bear-Poppy, Arctomecon Humilis Coville (Papaveraceae) Using Microsatellite Markers, Joshua Simpson Feb 2014

Phylogeny And Population Genetics Of The Endangered Dwarf Bear-Poppy, Arctomecon Humilis Coville (Papaveraceae) Using Microsatellite Markers, Joshua Simpson

Dissertations, Theses, and Capstone Projects

The genus Arctomecon (Papaveraceae) is comprised of three narrowly endemic rare species that are largely restricted to gypsum soils of the eastern Mojave Desert. The small, remaining populations of these species have become increasingly isolated by urban development and habitat fragmentation. Arctomecon humilis is federally listed as endangered due to its limited distribution within a ~15 km radius of an actively expanding city. Organizations involved with land management and conservation have called for greater insight into the genetic variation and population structure of the remaining subpopulations as they make important decisions regarding where to focus their efforts and resources.

The …