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2020

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Articles 18271 - 18300 of 24216

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The Use Of Water-Soluble Phthalocyanines As Textile Dyes In Nylon/Elastane Fabric: Fastness And Antibacterial Effectiveness, Armağan Günsel, Ayşe Usluoğlu, Ahmet Turgut Bi̇lgi̇çli̇, Büşra Tosun, Gülnur Arabaci, Meryem Ni̇lüfer Yaraşir Jan 2020

The Use Of Water-Soluble Phthalocyanines As Textile Dyes In Nylon/Elastane Fabric: Fastness And Antibacterial Effectiveness, Armağan Günsel, Ayşe Usluoğlu, Ahmet Turgut Bi̇lgi̇çli̇, Büşra Tosun, Gülnur Arabaci, Meryem Ni̇lüfer Yaraşir

Turkish Journal of Chemistry

This work reports on dyeing of nylon/elastane fabric with water-soluble phthalocyanines (1-4) bearing quinoline 5-sulfonic acid substituents on the peripheral or nonperipheral positions and determining the antibacterial efficiency of the phthalocyanine compounds and the dyed nylon/elastane fabrics. The light, washing, water, perspiration, and rubbing fastness properties of nylon/elastane fabrics dyed with phthalocyanines were also determined. The results showed that all dyed fabrics showed very good wet fastness values. The lightfastness value of the nylon/elastane fabric dyed with phthalocyanine dye (1) showed a much better value than the others. Also, the antibacterial efficiencies of the dyed nylon fabrics and the dye …


Bis Benzothiophene Schiff Bases: Synthesis And In Silico-Guided Biological Activity Studies, Yasemi̇n Ünver, Di̇lek Ünlüer, Şahi̇n Di̇rekel, Serdar Durdaği Jan 2020

Bis Benzothiophene Schiff Bases: Synthesis And In Silico-Guided Biological Activity Studies, Yasemi̇n Ünver, Di̇lek Ünlüer, Şahi̇n Di̇rekel, Serdar Durdaği

Turkish Journal of Chemistry

Since benzo [$b$] thiophene scaffold is one of the privileged structures in drug discovery as this core exhibitsactivities for different biological problems, in this study bis (benzo[$b$]thiophene-2-yl) alkyl methanimine derivatives (1-9) were synthesized by reacting benzo[$b$]thiophene-2-carbaldehyde with diamines. All newly compounds were characterized by IR, $^{1}$H NMR and $^{13}$C NMR spectroscopic methods. Synthesized compounds were investigated using binary QSAR-based models on therapeutic activity prediction of synthesized compounds and they showed high predicted activities in following diseases: bacterial, angina, allergy, depression and obesity. Thus, they were then tested for their antimicrobial and antileishmanial activities as a result of this theoretical study. …


Effect Of Mg Doping On Morphology, Photocatalytic Activity And Related Biological Properties Of Zn$_{\Mathbf{1-X}}$ Mg$_{X}$ O Nanoparticles, Bestenur Yalçin, Doğan Akcan, İbrahi̇m Ertuğrul Yalçin, Mehmet Can Alphan, Kenan Şentürk, İbrahi̇m İlker Özyi̇ği̇t, Lütfi̇ Arda Jan 2020

Effect Of Mg Doping On Morphology, Photocatalytic Activity And Related Biological Properties Of Zn$_{\Mathbf{1-X}}$ Mg$_{X}$ O Nanoparticles, Bestenur Yalçin, Doğan Akcan, İbrahi̇m Ertuğrul Yalçin, Mehmet Can Alphan, Kenan Şentürk, İbrahi̇m İlker Özyi̇ği̇t, Lütfi̇ Arda

Turkish Journal of Chemistry

The objective of this study is to synthesize ZnO and Mg doped ZnO (Zn$_{1-x}$Mg$_{x}$O) nanoparticles via the sol-gel method, and characterize their structures and to investigate their biological properties such as antibacterial activity and hemolytic potential.Nanoparticles (NPs) were synthesized by the sol-gel method using zinc acetate dihydrate (Zn(CH$_{3}$COO)$_{2}$.2H$_{2}$O) and magnesium acetate tetrahydrate (Mg(CH$_{3}$COO)$_{2}$.4H$_{2}$O) as precursors. Methanol and monoethanolamine were used as solvent and sol stabilizer, respectively. Structural and morphological characterizations of Zn$_{1-x}$Mg$_{x}$O nanoparticles were studied by using XRD and SEM-EDX, respectively. Photocatalytic activities of ZnO and selected Mg-doped ZnO (Zn$_{1-x}$Mg$_{x}$O) nanoparticles were investigated by degradation of methylene blue (MeB). Results …


The Production Of Enantiomerically Pure 1-Phenylethanol By Enzymatic Kineticresolution Method Using Response Surface Methodology, Ayşe Bozan, Rahi̇me Songür, Ülkü Mehmetoğlu Jan 2020

The Production Of Enantiomerically Pure 1-Phenylethanol By Enzymatic Kineticresolution Method Using Response Surface Methodology, Ayşe Bozan, Rahi̇me Songür, Ülkü Mehmetoğlu

Turkish Journal of Chemistry

As the enantiomers of 1-phenylethanol are valuable intermediates in several industries, the lipase catalyzed kinetic resolution of (R,S) -1-phenylethanol is a relevant research topic. In this study, the goal was to determine the optimum reaction parameters to produce enantiomerically pure 1-phenylethanol by lipase (Novozyme 435) catalyzed kinetic resolution using response surface methodology (RSM). Reactions were performed with 40-400 mM (R,S)-1-phenylethanol, 120-1200 mM vinyl acetate and 2-22 mg/ mL biocatalyst concentrations (BC$_{L}$), at 20-60 °C and with a stirring rate of 50-400 rpm for 5-120 min. The samples were analyzed using high performance liquid chromatography (HPLC) with a Chiralcel OB column. …


Tuning The Mechanical Properties And Degradation Properties Of Polydioxanoneisothermal Annealing, Xiliang Liu, Shaomin Feng, Xin Wang, Jin Qi, Dong Lei, Yadong Li, Wei Bai Jan 2020

Tuning The Mechanical Properties And Degradation Properties Of Polydioxanoneisothermal Annealing, Xiliang Liu, Shaomin Feng, Xin Wang, Jin Qi, Dong Lei, Yadong Li, Wei Bai

Turkish Journal of Chemistry

Polydioxanone (PPDO) is synthesized by ring-opening polymerization of p-dioxanone, using stannous octoate as the catalyst. The polarized optical micrograph (POM) shows thes pherulite growth rate of PPDO decreases with an increase in the isothermal crystallization temperature. PPDO is compression-molded into bars, and PPDO bars are subjected to isothermal annealing at a range of temperatures (Ta = 50, 60, 70, 80, 90, and 100 °C), and correspond to three different annealing times (ta = 1h, 2h, 3h). The effect on PPDO is investigated by using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). With …


Characterization And Kinetics Analysis Of The Thermal Decomposition Of The Humic Substance From Hazelnut Husk, Fatma Kara, Duygu Adigüzel, Ufuk Atmaca, Murat Çeli̇k, Jale Nakti̇yok Jan 2020

Characterization And Kinetics Analysis Of The Thermal Decomposition Of The Humic Substance From Hazelnut Husk, Fatma Kara, Duygu Adigüzel, Ufuk Atmaca, Murat Çeli̇k, Jale Nakti̇yok

Turkish Journal of Chemistry

A humic substance was obtained from hazelnut husk using an alkali extraction. The chemical and morphological structure of the humic matter was characterized via elemental analysis, Fourier transform infrared spectrometry (FTIR), nuclear magnetic resonance, Brunauer-Emmet-Teller (BET) analysis, scanning electron microscopy (SEM), and thermogravimetric-FTIR (TG-FTIR). In addition, thermal analysis measurements TG analysis-differential thermogravimetry/differential scanning calorimetry (TGA-DTG/ DSC) were performed under dynamic air conditions to better determine the origin, physical and chemical structure, and decomposition process of the humic matter. The Kissinger-Akahira-Sunose (KAS) and Flynn-Wall-Ozawa (FWO) methods were used to calculate the kinetic parameters of the high-temperature decomposition process. It was observed …


Processing Impact On Tocopherols And Triglycerides Composition Of Soybean Oil And Its Deodorizer Distillate Evaluated By High-Performance Liquid Chromatography, Zahid Hussain Laghari, Syed Tufail Hussain Sherazi, Hami̇de Fi̇li̇z Ayyildiz, Mustafa Topkafa, Hüseyi̇n Kara, Sarfaraz Ahmed Mahesar, Siraj Uddin Jan 2020

Processing Impact On Tocopherols And Triglycerides Composition Of Soybean Oil And Its Deodorizer Distillate Evaluated By High-Performance Liquid Chromatography, Zahid Hussain Laghari, Syed Tufail Hussain Sherazi, Hami̇de Fi̇li̇z Ayyildiz, Mustafa Topkafa, Hüseyi̇n Kara, Sarfaraz Ahmed Mahesar, Siraj Uddin

Turkish Journal of Chemistry

In the present study, high-performance liquid chromatography (HPLC) was used for the separation of tocopherols and triglycerides of processed soybean oil and deodorizer distillate (DD). The results of normal and reversed-phase modes of HPLC revealed that concentrations of tocopherols and triglycerides content were decreased during the neutralization, bleaching, and deodorization processes. The loss of individual tocopherols ranged between 55.16% and 63.25%. During processing, triglycerides containing stearic-oleic-linoleic (SOL) moieties and palmitic-palmitic-linoleic (PPL) fragments showed greater reduction up to 38.14% and 37.69%, respectively. Among tocopherols and triglycerides; γ-tocopherol and oleic-oleic-oleic (OOO) were found to be in greater concentrations 5.53% and 19.78%, respectively …


Highly Luminescent Water-Dispersed Silicon Quantum Dots For Fluorometric Determination Of Oxytetracycline In Milk Samples, Hayri̇ye Eda Şatana Kara, Burak Demi̇rhan, Buket Er Demi̇rhan Jan 2020

Highly Luminescent Water-Dispersed Silicon Quantum Dots For Fluorometric Determination Of Oxytetracycline In Milk Samples, Hayri̇ye Eda Şatana Kara, Burak Demi̇rhan, Buket Er Demi̇rhan

Turkish Journal of Chemistry

A fluorescent probe based on silicon quantum dots (SiQDs) was developed for the selective and sensitive detection of oxytetracycline (OTC) via the inner filter effect (IFE). The water-soluble fluorescent SiQD was synthesized based on the reaction of 3-Aminopropyltriethoxysilane (APTES) and sodium citrate as precursors by the one-pot hydrothermal process. The strong fluorescence emission of quantum dots (QDs) was obtained at 440 nm when excited at 350 nm and OTC had a broad absorption band between 200 and 400 nm. The excitation spectrum of SiQDs was completely overlapped with the absorption spectrum of OTC. The light at an excitation wavelength of …


Synthesis, Antioxidant And Antimicrobial Properties Of Novel Pyridyl-Carbonyl Thiazoles As Dendrodoine Analogs, Zafer Şahi̇n, Sevde Nur Bi̇lteki̇n, Leyla Yurttaş, Şeref Demi̇rayak Jan 2020

Synthesis, Antioxidant And Antimicrobial Properties Of Novel Pyridyl-Carbonyl Thiazoles As Dendrodoine Analogs, Zafer Şahi̇n, Sevde Nur Bi̇lteki̇n, Leyla Yurttaş, Şeref Demi̇rayak

Turkish Journal of Chemistry

Marine compound dendrodoine was first obtained from tunicate species (Dendrodo grossularia). It has a five-membered ring, namely, it is a heterocycle thiadiazole, which is found rarely in natural sources. Following its biological activities, novel analogs have been investigated recently. Synthesis of the analogs for this study is realized with uncommon thiazole closure, including methylene-carbonyl condensation. Structures are elucidated by NMR (1H, 13C) and HRMS spectrums. As an alkaloid derivative, antioxidant properties were evaluated with DPPH and FRAP assays and antimicrobial effect with microdilution method. Among the series, 3bc-3cf showed higher antioxidant activity than those having 3 or 4-pyridyl substituents. There …


Graduate Level Distance Learning: Enhanced Student Experience, Significant Scalability Challenges: A Multiyear Case Study, Karen Thornton, Steven L. Schooner, Markus Speidel Jan 2020

Graduate Level Distance Learning: Enhanced Student Experience, Significant Scalability Challenges: A Multiyear Case Study, Karen Thornton, Steven L. Schooner, Markus Speidel

GW Law Faculty Publications & Other Works

This article describes our experiences and "lessons learned" providing degree-based distance (online) education to graduate students (studying business, law, and policy related to government contracts or public procurement). Temporal note: our pilot, and the five years of experience described in this case study, predate the 2020 Coronavirus Pandemic emergency distance teaching transition.

Among other things, we discuss our experiences with regard to fundamentally rethinking our pedagogical approach, "flipping the classroom," chunking, and scaffolded learning. We extol the benefits of working with, and being open to, advice from experienced instructional designers.

We conclude that embracing distance education, at least in a …


Sentenced To Surveillance: Fourth Amendment Limits On Electronic Monitoring, Kate Weisburd Jan 2020

Sentenced To Surveillance: Fourth Amendment Limits On Electronic Monitoring, Kate Weisburd

GW Law Faculty Publications & Other Works

As courts and legislatures increasingly recognize that “digital is different” and attempt to limit government surveillance of private data, one group is conspicuously excluded from this new privacy-protective discourse: the five million people in the United States on probation, parole, or other forms of community supervision. This Article is the first to explore how warrantless electronic surveillance is dramatically transforming community supervision and, as a result, amplifying a growing privacy-protection disparity: those in the criminal legal system are increasingly losing privacy protections even while those not in the system are increasingly gaining privacy protections. The quickly expanding use of GPS-equipped …


Brand Name Or Equal: Without "Equal," It's Not Competitive, Steven L. Schooner Jan 2020

Brand Name Or Equal: Without "Equal," It's Not Competitive, Steven L. Schooner

GW Law Faculty Publications & Other Works

One of the more common rules in federal government procurement is that the Government may describe its needs to the private sector by specifying a “brand name” product, as long as the Government adds the words “or equal” to the brand name and articulates the product’s salient physical, functional, or performance characteristics that are essential to the Government’s needs. This broadens the potential for competition and helps reduce the government's reliance on unduly restrictive specifications.
Two recent examples - one the subject of a GAO bid protest decision, the other a recently posted commercial-item procurement - suggest that, while some …


Great Powers And New Risks: What Businesses And Regulators Should Know About China’S Strategic Ambitions, F. Scott Kieff, Thomas D. Grant Jan 2020

Great Powers And New Risks: What Businesses And Regulators Should Know About China’S Strategic Ambitions, F. Scott Kieff, Thomas D. Grant

GW Law Faculty Publications & Other Works

China’s geopolitical ambitions give rise to risks that government agencies and the businesses they regulate need to address. In particular, Military-Civil Fusion (MCF), a whole-of-government legal and administrative machinery created by the Chinese Communist Party (CCP), aims to give China’s military, as well as China’s state championed companies, the technologies essential to strategic competitiveness in the decades ahead. In service of China’s effort to acquire technology, MCF breaks down barriers of professional responsibility and confidentiality that organizations and individuals in the West take for granted. Through both executive and legislative action, the United States has begun to address MCF. To …


‘Warming Up’ To Sustainable Procurement, Steven L. Schooner, Markus Speidel Jan 2020

‘Warming Up’ To Sustainable Procurement, Steven L. Schooner, Markus Speidel

GW Law Faculty Publications & Other Works

Procurement professionals will play a critical role in the belated but necessary effort to slow the pace of climate change. That critical, evolved role will lie in sustainable procurement, which, if effectively implemented, will dramatically alter markets and fundamentally change purchasing behaviors. To be effective, procurement professionals will need to rethink how we define our profession, assess our outcomes, and bring value to our government customers. Successfully establishing a sustainable procurement regime will require dramatic change, including, among other things, overcoming the persistent tyranny of low price, understanding and adopting lifecycle costing, considering externalities in the value proposition, and, of …


Differences In Blood-Derived Francisella Tularensis Type B Strains From Clinical Cases Of Tularemia, Marilyn A. Larson, Baha Abdalhamid, Bhanwar Lal Puniya, Tomáš Helikar, David W. Kelley, Peter C. Iwen Jan 2020

Differences In Blood-Derived Francisella Tularensis Type B Strains From Clinical Cases Of Tularemia, Marilyn A. Larson, Baha Abdalhamid, Bhanwar Lal Puniya, Tomáš Helikar, David W. Kelley, Peter C. Iwen

Department of Biochemistry: Faculty Publications

Francisella tularensis can cause the zoonotic disease tularemia and is partitioned into subspecies due to differences in chromosomal organization and virulence. The subspecies holarctica (type B) is generally considered more clonal than the other subpopulations with moderate virulence compared to the hypervirulent A.I clade. We performed whole genome sequencing (WGS) on six type B strains isolated from the blood of patients with tularemia within a one-year period from the same United States region, to better understand the associated pathogenicity. The WGS data were compared to the prototype strain for this subspecies, specifically FSC200, which was isolated from a patient with …


Systematic Age-, Organ-, And Diet-Associated Ionome Remodeling And The Development Of Ionomic Aging Clocks, Bohan Zhang, Dmitriy I. Podolskiy, Marco Mariotti, Javier Seravalli, Vadim N. Gladyshev Jan 2020

Systematic Age-, Organ-, And Diet-Associated Ionome Remodeling And The Development Of Ionomic Aging Clocks, Bohan Zhang, Dmitriy I. Podolskiy, Marco Mariotti, Javier Seravalli, Vadim N. Gladyshev

Department of Biochemistry: Faculty Publications

Aging involves coordinated yet distinct changes in organs and systems throughout life, including changes in essential trace elements. However, how aging affects tissue element composition (ionome) and how these changes lead to dysfunction and dis-ease remain unclear. Here, we quantified changes in the ionome across eight organs and 16 age groups of mice. This global profiling revealed novel interactions between elements at the level of tissue, age, and diet, and allowed us to achieve a broader, organismal view of the aging process. We found that while the entire ionome stead-ily transitions along the young-to-old trajectory, individual organs are characterized by …


Reactive Oxygen Species (Ros) Mediated Degradation Of Organophosphate T Pesticides By The Green Microalgae Coccomyxa Subellipsoidea☆, Timothy J Nicodemus, Concetta C. Dirusso, Mark A. Wilson, Paul N. Black Jan 2020

Reactive Oxygen Species (Ros) Mediated Degradation Of Organophosphate T Pesticides By The Green Microalgae Coccomyxa Subellipsoidea☆, Timothy J Nicodemus, Concetta C. Dirusso, Mark A. Wilson, Paul N. Black

Department of Biochemistry: Faculty Publications

The aim of this study was to define the mechanism allowing the green alga Coccomyxa subellipsoidea to break down organophosphates from agricultural run-off. This study found that metabolically active cultures of the microalga C. subellipsoidea breakdown organophosphates (paraoxon, malathion and diazinon) with differing structural conformations in freshwater through a mechanism that requires the formation of reactive oxygen species (ROS) with little to no toxic effects on the algae. Under these conditions, organophosphate levels were reduced to 0.1 mg/mL or less over the 8–10 day experimental period. These findings demonstrate a biological- based system can be tailored for the remediation of …


Sestrins Are Evolutionarily Conserved Mediators Of Exercise Benefits, Myungjin Kim, Alyson Sujkowski, Sim Namkoong, Bondong Gu, Tyler Cobb, Boyoung Kim, Allison H. Kowalsky, Chun-Seok Cho, Ian Semple, Seung-Hyun Ro, Carol Davis, Susan V. Brooks, Michael Karin, Robert J. Wessells, Jun Hee Lee Jan 2020

Sestrins Are Evolutionarily Conserved Mediators Of Exercise Benefits, Myungjin Kim, Alyson Sujkowski, Sim Namkoong, Bondong Gu, Tyler Cobb, Boyoung Kim, Allison H. Kowalsky, Chun-Seok Cho, Ian Semple, Seung-Hyun Ro, Carol Davis, Susan V. Brooks, Michael Karin, Robert J. Wessells, Jun Hee Lee

Department of Biochemistry: Faculty Publications

Exercise is among the most effective interventions for age-associated mobility decline and metabolic dysregulation. Although long-term endurance exercise promotes insulin sensitivity and expands respiratory capacity, genetic components and pathways mediating the meta- bolic benefits of exercise have remained elusive. Here, we show that Sestrins, a family of evolutionarily conserved exercise-inducible proteins, are critical mediators of exercise ben- efits. In both fly and mouse models, genetic ablation of Sestrins prevents organisms from acquiring metabolic benefits of exercise and improving their endurance through training. Conversely, Sestrin upregulation mimics both molecular and physiological effects of exercise, suggesting that it could be a major …


Photosynthetic Efficiency And Mesophyll Conductance Are Unaffected In Arabidopsis Thaliana Aquaporin Knock-Out Lines, Johannes Kromdijk, Katarzyna Głowacka, Stephen P. Long Jan 2020

Photosynthetic Efficiency And Mesophyll Conductance Are Unaffected In Arabidopsis Thaliana Aquaporin Knock-Out Lines, Johannes Kromdijk, Katarzyna Głowacka, Stephen P. Long

Department of Biochemistry: Faculty Publications

Improving photosynthetic efficiency is widely regarded as a major route to achieving much-needed yield gains in crop plants. In plants with C3 photosynthesis, increasing the diffusion conductance for CO2 transfer from substomatal cavity to chloroplast stroma (gm) could help to improve the efficiencies of CO2 assimilation and photosynthetic water use in parallel. The diffusion pathway from substomatal cavity to chloroplast traverses cell wall, plasma membrane, cytosol, chloroplast envelope membranes, and chloroplast stroma. Specific membrane intrinsic proteins of the aquaporin family can facilitate CO2 diffusion across membranes. Some of these aquaporins, such as PIP1;2 …


An Ortholog Of The Vasa Intronic Gene Is Required For Small Rna-Mediated Translation Repression In Chlamydomonas Reinhardtii, Xinrong Ma, Fadia Ibrahim, Eun-Jeong Kim, Scott Shaver, James Becker, Fareha Razvi, Ronald L. Cerny, Heriberto D. Cerutti Jan 2020

An Ortholog Of The Vasa Intronic Gene Is Required For Small Rna-Mediated Translation Repression In Chlamydomonas Reinhardtii, Xinrong Ma, Fadia Ibrahim, Eun-Jeong Kim, Scott Shaver, James Becker, Fareha Razvi, Ronald L. Cerny, Heriberto D. Cerutti

School of Biological Sciences: Faculty Publications

Small RNAs (sRNAs) associate with Argonaute (AGO) proteins in effector complexes, termed RNA-induced silencing complexes (RISCs), which regulate complementary transcripts by translation inhibition and/or RNA degradation. In the unicellular alga Chlamydomonas, several metazoans, and land plants, emerging evidence indicates that polyribosome-associated transcripts can be translationally repressed by RISCs without substantial messenger RNA (mRNA) destabilization. However, the mechanism of translation inhibition in a polyribosomal context is not understood. Here we show that Chlamydomonas VIG1, an ortholog of the Drosophila melanogaster Vasa intronic gene (VIG), is required for this process. VIG1 localizes predominantly in the cytosol and comigrates with monoribosomes and …


Mitochondrial Dna Repair In An Arabidopsis Thaliana Uracil N-Glycosylase Mutant, Emily L. Wynn, Emma Purfeerst, Alan Christensen Jan 2020

Mitochondrial Dna Repair In An Arabidopsis Thaliana Uracil N-Glycosylase Mutant, Emily L. Wynn, Emma Purfeerst, Alan Christensen

School of Biological Sciences: Faculty Publications

Substitution rates in plant mitochondrial genes are extremely low, indicating strong selective pressure as well as efficient repair. Plant mitochondria possess base excision repair pathways; however, many repair pathways such as nucleotide excision repair and mismatch repair appear to be absent. In the absence of these pathways, many DNA lesions must be repaired by a different mechanism. To test the hypothesis that double-strand break repair (DSBR) is that mechanism, we maintained independent self-crossing lineages of plants deficient in uracil-N-glycosylase (UNG) for 11 generations to determine the repair outcomes when that pathway is missing. Surprisingly, no single nucleotide polymorphisms (SNPs) were …


Temperature Alters The Shape Of Predator–Prey Cycles Through Effects On Underlying Mechanisms, John P. Delong, Shelby Lyon Jan 2020

Temperature Alters The Shape Of Predator–Prey Cycles Through Effects On Underlying Mechanisms, John P. Delong, Shelby Lyon

School of Biological Sciences: Faculty Publications

Background: Predicting the effects of climate warming on the dynamics of ecological systems requires understanding how temperature influences birth rates, death rates and the strength of species interactions. The temperature dependance of these processes—which are the underlying mechanisms of ecological dynamics—is often thought to be exponential or unimodal, generally supported by short-term experiments. However, ecological dynamics unfold over many generations. Our goal was to empirically document shifts in predator–prey cycles over the full range of temperatures that can possibly support a predator–prey system and then to uncover the effect of temperature on the underlying mechanisms driving those changes.

Methods: We …


Divergent Density Feedback Control Of Migratory Predator Recovery Following Sex-Biased Perturbations, Daisuke Goto, Martin J. Hamel, Mark A. Pegg, Jeremy J. Hammen, Matthew L. Rugg, Valery E. Forbes Jan 2020

Divergent Density Feedback Control Of Migratory Predator Recovery Following Sex-Biased Perturbations, Daisuke Goto, Martin J. Hamel, Mark A. Pegg, Jeremy J. Hammen, Matthew L. Rugg, Valery E. Forbes

School of Biological Sciences: Faculty Publications

Uncertainty in risks posed by emerging stressors such as synthetic hormones im-pedes conservation efforts for threatened vertebrate populations. Synthetic hor-mones often induce sex-biased perturbations in exposed animals by disrupting gonad development and early life-history stage transitions, potentially diminishing per capita reproductive output of depleted populations and, in turn, being manifest as Allee effects. We use a spatially explicit biophysical model to evaluate how sex-biased perturbation in life-history traits of individuals (maternal investment in egg production and male-skewed sex allocation in offspring) modulates density feedback control of year-class strength and recovery trajectories of a long-lived, migratory fish—shovelnose sturgeon (Scaphirhynchus platorynchus)—under spatially …


A High-Throughput Method To Quantify Feeding Rates In Aquatic Organisms: A Case Study With Daphnia, Jessica L. Hite, Alaina C. Pfenning-Butterworth, Rachel E. Vetter, Clayton E. Cressler Jan 2020

A High-Throughput Method To Quantify Feeding Rates In Aquatic Organisms: A Case Study With Daphnia, Jessica L. Hite, Alaina C. Pfenning-Butterworth, Rachel E. Vetter, Clayton E. Cressler

School of Biological Sciences: Faculty Publications

1. Food ingestion is one of the most basic features of all organisms. However, obtaining precise—and high-throughput—estimates of feeding rates remains challenging, particularly for small, aquatic herbivores such as zooplankton, snails, and tadpoles. These animals typically consume low volumes of food that are time-consuming to accurately measure.

2. We extend a standard high-throughput fluorometry technique, which uses a microplate reader and 96-well plates, as a practical tool for studies in ecology, evolution, and disease biology. We outline technical and methodological details to optimize quantification of individual feeding rates, improve accuracy, and minimize sampling error.

3. This high-throughput assay offers several …


Adaptations Of Interferon Regulatory Factor 3 With Transition From Terrestrial To Aquatic Life, Monica Angeletti, Wan-Ling Nicole Hsu, Nashaat Majo, Hideaki Moriyama, Etsuko Moriyama, Luwen Zhang Jan 2020

Adaptations Of Interferon Regulatory Factor 3 With Transition From Terrestrial To Aquatic Life, Monica Angeletti, Wan-Ling Nicole Hsu, Nashaat Majo, Hideaki Moriyama, Etsuko Moriyama, Luwen Zhang

School of Biological Sciences: Faculty Publications

Interferon regulatory factor 3 (IRF3) and IRF7 are closely related IRF members and the major factors for the induction of interferons, a key component in vertebrate innate immunity. However, there is limited knowledge regarding the evolution and adaptation of those IRFs to the environments. Two unique motifs in IRF3 and 7 were identified. One motif, GASSL, is highly conserved throughout the evolution of IRF3 and 7 and located in the signal response domain. Another motif, DPHK, is in the DNA-binding domain. The ancestral protein of IRF3 and 7 seemed to possess the DPHK motif. In the ray-finned fish lineage, while …


Functional Responses Are Maximized At Intermediate Temperatures, Stella F. Uiterwaal, John Delong Jan 2020

Functional Responses Are Maximized At Intermediate Temperatures, Stella F. Uiterwaal, John Delong

School of Biological Sciences: Faculty Publications

Functional responses describe how consumer foraging rates change with resource density. Despite extensive research looking at the factors underlying foraging interactions, there remains ongoing controversy about how temperature and body size control the functional response parameters space clearance (or attack) rate and handling time. Here, we investigate the effects of temperature, consumer mass, and resource mass using the largest compilation of functional responses yet assembled. This compilation contains 2,083 functional response curves covering a wide range of foragers and prey types, environmental conditions, and habitats. After accounting for experimental arena size, dimensionality of the foraging interaction, and consumer taxon, we …


Invited Commentaries On Shizuka & Johnson 2020, & Response From The Authors, Adriana A. Maldonado-Chaparro, Damien R. Farine, Amiyaal Ilany, Orr Spiegel, Noa Pinter-Wollman, Ipek G. Kulahci, Eric Vander Wal, Quinn M.R. Webber, Daniel I. Rudenstein, Daizaburo Shizuka, Allison E. Johnson Jan 2020

Invited Commentaries On Shizuka & Johnson 2020, & Response From The Authors, Adriana A. Maldonado-Chaparro, Damien R. Farine, Amiyaal Ilany, Orr Spiegel, Noa Pinter-Wollman, Ipek G. Kulahci, Eric Vander Wal, Quinn M.R. Webber, Daniel I. Rudenstein, Daizaburo Shizuka, Allison E. Johnson

School of Biological Sciences: Faculty Publications

Adriana A. Maldonado-Chaparro and Damien R. Farine, Demographic processes in animal networks are a question of time

Amiyaal Ilany, Complex societies, simple processes

Orr Spiegel and Noa Pinter-Wollman, Placing the effects of demography on networks in ecological context

Ipek G. Kulahci, Individual differences can affect how networks respond to demography

Eric Vander Wal and Quinn M.R. Webber, Density dependence and eco-evolutionary dynamics of animal social networks

Daniel I. Rubenstein, On assessing the importance of demographic change for social structure

Daizaburo Shizuka and Allison E. Johnson, The long view on demographic effects on social networks: A response to comments on Shizuka …


International Law And Theories Of Global Justice: Remarks, Steven R. Ratner, James Stewart, Jiewuh Song, Carmen Pavel Jan 2020

International Law And Theories Of Global Justice: Remarks, Steven R. Ratner, James Stewart, Jiewuh Song, Carmen Pavel

Articles

International law (IL) and political philosophy represent two rich disciplines for exploring issues of global justice. At their core, each seeks to build a better world based on some universally agreed norms, rules, and practices, backed by effective institutions. International lawyers, even the most positivist of them, have some underlying assumptions about a just world order that predisposes their interpretive methods; legal scholars have incorporated concepts of justice in their work even as their overall pragmatic orientation has limited the nature of their inquiries. Many philospophers, for their part, have engaged with IL to some extent—at a minimum recognizing that …


Investigating The Relationship Between Individual Differences And Island Sensitivity, Catherine Pham, Lauren Covey, Alison Gabriele, Saad Aldosari, Robert Fiorentino Jan 2020

Investigating The Relationship Between Individual Differences And Island Sensitivity, Catherine Pham, Lauren Covey, Alison Gabriele, Saad Aldosari, Robert Fiorentino

Department of Linguistics Faculty Scholarship and Creative Works

It is well-attested that native speakers tend to give low acceptability ratings to sentences that involve movement from within islands, yet the source of island effects remains an active debate. The grammatical account posits that island effects result from syntactic constraints on wh-movement, whereas the resource-limitation view posits that low ratings emerge due to processing-related constraints on the parser, such that islands themselves present processing bottlenecks. The current study addresses this debate by investigating the relationship between island sensitivity and individual differences in cognitive abilities, as it has been argued that the two views make distinct predictions regarding whether a …


Fichte And Schelling, Michael Vater Jan 2020

Fichte And Schelling, Michael Vater

Philosophy Faculty Research and Publications

No abstract provided.