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Articles 55951 - 55980 of 255936

Full-Text Articles in Life Sciences

Songbird Brain Organization And Its Molecular Convergence With Humans For Vocal Imitation Learning, Gregory Gedman Jan 2022

Songbird Brain Organization And Its Molecular Convergence With Humans For Vocal Imitation Learning, Gregory Gedman

Student Theses and Dissertations

The rich diversity of neural cell populations and their specialized connections give rise to a suite of complex behaviors across vertebrates. The presence of common neural cell types may be a product of either shared ancestry through homology or parallel evolution through convergence. However, the extent as to which these two processes are utilized by diverse nervous systems is poorly understood. Understanding the evolutionary relationships of these neural populations, both within and across vertebrate species, is critical for the study of complex trait evolution. Here, I investigate these two evolutionary processes within the adult avian brain and their impact on …

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Human Antibody Response To Flaviviruses And Sars-Coronavirus-2, Marianna Elizabeth Agudelo Jan 2022

Human Antibody Response To Flaviviruses And Sars-Coronavirus-2, Marianna Elizabeth Agudelo

Student Theses and Dissertations

The last decade has seen a number of viral epidemics and global pandemic. Increased global connectivity makes the likelihood of future mass outbreaks ever greater. Understanding the adaptive immune response to these pathogens will expand basic understanding of viral immunity mechanisms and can help inform vaccine and therapeutic development. This thesis describes the characterization of the human antibody response to several important viral pathogens, all of which are either emerging pathogens posing significant public health burdens or are already responsible for epidemic outbreaks. These include tick-borne encephalitis virus (TBEV), Powassan virus (POWV), Zika virus (ZIKV) and severe acute respiratory syndrome …

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Nonlinear Representation Of Auditory Stimuli Across The Auditory Cortex, Frank Tejera Leon Jan 2022

Nonlinear Representation Of Auditory Stimuli Across The Auditory Cortex, Frank Tejera Leon

Student Theses and Dissertations

The neural evoke activity to pure tones in primary auditory cortex has been systematically studied for many years, as has the spatial organization of these responses. Unlike pure tones, natural sounds possess complex spectro-temporal structures across frequencies. How simple tuning properties scale across ensembles of neurons to represent more complex sensory environments is still a question of active investigation and debate. To better understand the coding principles used to represent complex auditory sounds, we performed 2-photon calcium imaging of neural activity of the entire auditory cortex in awake mice, while playing sounds composed of single or multiple frequencies. While we …

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Building An Allocentric Traveling-Direction Signal Via Vector Computation, Cheng Lyu Jan 2022

Building An Allocentric Traveling-Direction Signal Via Vector Computation, Cheng Lyu

Student Theses and Dissertations

Many behavioral tasks require the manipulation of mathematical vectors, but, outside of computational models, it is not known how brains perform vector operations. Here we show how the Drosophila central complex, a region implicated in goal-directed navigation, performs vector arithmetic. First, we describe a neural signal in the fan-shaped body that explicitly tracks a fly's allocentric traveling angle, that is, the traveling angle in reference to external cues. Past work has identified neurons in Drosophila and mammals that track an animal's heading angle referenced to external cues (e.g., head-direction cells), but this new signal illuminates how the sense of space …

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Peptidergic Signaling Controls The Dynamics Of Sickness Behavior In Caenorhabditis Elegans, Javier Marquina-Solis Jan 2022

Peptidergic Signaling Controls The Dynamics Of Sickness Behavior In Caenorhabditis Elegans, Javier Marquina-Solis

Student Theses and Dissertations

Disease is accompanied by modifications to host behavior that promote recovery and survival. The neural and molecular mechanisms that rule the switch to a sickness behavioral state are an active area of research. One established model for sickness behavior is the interaction between Caenorhabditis elegans and the pathogenic bacteria Pseudomonas aeruginosa PA14. After a few hours of exposure to and infection by PA14, C. elegans develops a sickness-like behavior termed pathogen avoidance. Here I identify neuronal signals generated during the infection and associate them with antagonistic circuits that shape the host behavior. Using an unbiased cell-directed neuropeptide screen, I show …

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A Developmental Pathway For Epithelial-To-Motoneuron Transformation In C. Elegans, Alina Rashid Jan 2022

A Developmental Pathway For Epithelial-To-Motoneuron Transformation In C. Elegans, Alina Rashid

Student Theses and Dissertations

During animal development, neurons and neuron-like cells are generated from progenitor cells that often line tubes. For example, in the developing spinal cord, basal processes of radial glial stem cells line the fluid-filled spinal canal. Notch/Delta signaling is implicated in the differentiation of these cells into motoneurons through control of their proliferative state. Down-regulation of the Notch-dependent Hes1 and Hes5 transcriptional inhibitors in differentiating cells induces expression of the proneural bHLH transcription factors Olig2 and Ngn2, leading to adherens junction loss, delamination from the epithelium, cell migration, and neuronal maturation. A similar sequence of events characterizes formation of pancreatic insulin-secreting …

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Palbociclib Suppresses The Cancer Stem Cell Properties And Cell Proliferation Through Increased Levels Of Mir-506 Or Mir-150 In Panc-1 And Miapaca-2 Cells, Özge Rencüzoğullari, Eli̇f Damla Arisan Jan 2022

Palbociclib Suppresses The Cancer Stem Cell Properties And Cell Proliferation Through Increased Levels Of Mir-506 Or Mir-150 In Panc-1 And Miapaca-2 Cells, Özge Rencüzoğullari, Eli̇f Damla Arisan

Turkish Journal of Biology

The prognostic characteristics of pancreatic cancer (PC) are determined by the contributing factors from the tumor microenvironment. Leptin is a critical oncogenic factor released by adipocytes as an adipokine into the tumor microenvironment, where it promotes tumor development by activating cancer stem cell (CSC) molecular regulators Notch, Hedgehog, and Wnt/ß-catenin signaling. One of the downstream targets of these pathways is CDK4/6 and cyclin D which is controlled by P16 INK4A that is highly mutated in PC. Therefore, the purpose of this study was to determine the effect of a CDK4/6 inhibitor, palbociclib, on Leptin-induced PC cells and to target the …

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Epidemiology And Management Of Frogeye Leaf Spot Of Soybean: Damage Thresholds, Efficacy And Profitability Of Foliar Fungicides, Jhonatan Paulo Barro Jan 2022

Epidemiology And Management Of Frogeye Leaf Spot Of Soybean: Damage Thresholds, Efficacy And Profitability Of Foliar Fungicides, Jhonatan Paulo Barro

Theses and Dissertations--Plant Pathology

Frogeye leaf spot (FLS), caused by Cercospora sojina, is an economically important disease of soybean in many parts of the world where soybean is grown, including the United States. A meta-analytic approach was used to summarize a data set of 66 uniform field research trials conducted to evaluate fungicide efficacy against FLS on soybean. The dataset spanned 10 years (2012 to 2021) of experiments conducted across eight states in the U.S., including Alabama, Arkansas, Illinois, Iowa, Kentucky, Louisiana, Mississippi and Tennessee. First, the relationship between FLS severity and soybean yield was investigated. A significant negative slope obtained through random …

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Academy Presidents And Institutional Members, Academy Editors Jan 2022

Academy Presidents And Institutional Members, Academy Editors

Journal of the Arkansas Academy of Science

No abstract provided.

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Table Of Contents, Academy Editors Jan 2022

Table Of Contents, Academy Editors

Journal of the Arkansas Academy of Science

No abstract provided.

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Factors Affecting The Sex Ratio Of White-Tailed Deer (Odocoileus Virginianus) Fetuses In Arkansas, Jorista Garrie, Ralph Meeker Jan 2022

Factors Affecting The Sex Ratio Of White-Tailed Deer (Odocoileus Virginianus) Fetuses In Arkansas, Jorista Garrie, Ralph Meeker

Journal of the Arkansas Academy of Science

Health of the mother is known to affect the sex-ratio of the offspring in sexually dimorphic mammals. Both density-dependent and environmental factors (conditions at present, or seasonal conditions the year before) could impact the health of the mother. There are however two opposing hypotheses for whether a mother in good health should invest more in a strong son (that can father many offspring) or in a daughter (that can stay in the same area and use good resources). Fetuses from 1,208 female white-tailed deer (Odocoileus virginianus) were collected over a 10-year period (2002-2012), across 75 counties in Arkansas. …

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Seasonal Testicular Histology And Acystic Lobular Spermatogenesis In The Western Lesser Siren, Siren Intermedia Nettingi (Caudata: Sirenidae), Stanley E. Trauth Jan 2022

Seasonal Testicular Histology And Acystic Lobular Spermatogenesis In The Western Lesser Siren, Siren Intermedia Nettingi (Caudata: Sirenidae), Stanley E. Trauth

Journal of the Arkansas Academy of Science

I investigated the seasonal testicular histology and acystic lobular spermatogenesis in the Western Lesser Siren, Siren intermedia nettingi, from periodic sampling of this salamander over a span of 21 yr (1994-2015) in northeastern Arkansas. My results include the following general findings: 1) the largest testicular lobules occurred primarily in January-February during spermiogenesis and spermatozoa maturation; 2) lobular regression and spermatogenic cell recrudescence were underway by late March; 3) proliferation of secondary spermatogonia in lobules was prominent in May; 4) transformation of secondary spermatogonia into primary spermatocytes occurred by mid-July, and these cells became larger in diameter through increased nuclear …

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Distribution And Breeding Of The Black-Bellied Whistling-Duck (Dendrocygna Autumnalis) In Arkansas, With A Brief Chronology Of Distribution And Breeding In Southeastern United States, C. Renn Tumlison Jan 2022

Distribution And Breeding Of The Black-Bellied Whistling-Duck (Dendrocygna Autumnalis) In Arkansas, With A Brief Chronology Of Distribution And Breeding In Southeastern United States, C. Renn Tumlison

Journal of the Arkansas Academy of Science

The Black-Bellied Whistling-Duck (Dendrocygna autumnalis) was a rare bird first reported from Arkansas in 1982, when it was seen in Hempstead Co. in southwestern Arkansas. Observations surged in parts of the state about 2005, then again about 2016, and the bird is now fairly common seasonally in many parts of the state. By use of online sources for citizen science, we elucidate the history of occurrence and present analysis of seasonal distribution of this bird in Arkansas. Individuals occur in Arkansas throughout the year, but observations are most common and widely distributed from March-September, after which most individuals …

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Additional Distributional Records For A Rare Caddisfly In The Ozarks, Frenesia Missa (Milne) (Trichoptera: Limnephilidae), David Bowles Jan 2022

Additional Distributional Records For A Rare Caddisfly In The Ozarks, Frenesia Missa (Milne) (Trichoptera: Limnephilidae), David Bowles

Journal of the Arkansas Academy of Science

This paper describes the distribution for this rare species in the Ozarks of Arkansas and Missouri thus expanding its known range in the region. The species is considered vulnerable to anthropogenic stressors.

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Effects Of Clipping Of Flight Feathers On Resource Use In Gallus Gallus Domesticus, Renee Garant, Bret W. Tobalske, Neila Bensassi, Nienke Van Staaveren, Dan Tulpan, Tina Widowski, Donald R. Powers, Alexandra Harlander-Matauschek Jan 2022

Effects Of Clipping Of Flight Feathers On Resource Use In Gallus Gallus Domesticus, Renee Garant, Bret W. Tobalske, Neila Bensassi, Nienke Van Staaveren, Dan Tulpan, Tina Widowski, Donald R. Powers, Alexandra Harlander-Matauschek

Faculty Publications - Department of Biological & Molecular Science

Ground-dwelling species of birds, such as domestic chickens (Gallus gallus domesticus), experience difficulties sustaining flight due to high wing loading. This limited flight ability may be exacerbated by loss of flight feathers that is prevalent among egg-laying chickens. Despite this, chickens housed in aviary style systems need to use flight to access essential resources stacked in vertical tiers. To understand the impact of flight feather loss on chickens’ ability to access elevated resources, we clipped primary and secondary flight feathers for two hen strains (brown-feathered and white-feathered, n = 120), and recorded the time hens spent at elevated resources (feeders, …

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Capacity And Kinetics Of Light‑Induced Cytochrome Oxidation In Intact Cells Of Photosynthetic Bacteria, Mariann Kis, James L. Smart, Péter Maróti Jan 2022

Capacity And Kinetics Of Light‑Induced Cytochrome Oxidation In Intact Cells Of Photosynthetic Bacteria, Mariann Kis, James L. Smart, Péter Maróti

Faculty Publications - Department of Biological & Molecular Science

Light-induced oxidation of the reaction center dimer and periplasmic cytochromes was detected by fast kinetic difference absorption changes in intact cells of wild type and cytochrome mutants (cycA, cytC4 and pufC) of Rubrivivax gelatinosus and Rhodobacter sphaeroides. Constant illumination from a laser diode or trains of saturating flashes enabled the kinetic separation of acceptor and donor redox processes, and the electron contribution from the cyt bc1 complex via periplasmic cytochromes. Under continuous excitation, concentrations of oxidized cytochromes increased in three phases where light intensity, electron transfer rate and the number of reduced cytochromes were the rate liming steps, respectively. By …

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Comparing Trebouxia Diversity In Lichen Genera Sympatric With The Niebla Species Complex., Anthony Perugini, Louise A. Lewis, Zachary M. Muscavitch Jan 2022

Comparing Trebouxia Diversity In Lichen Genera Sympatric With The Niebla Species Complex., Anthony Perugini, Louise A. Lewis, Zachary M. Muscavitch

Undergraduate Papers

Lichens are one of the most successful mutualisms on Earth. The ecology and distribution of lichen symbionts likely influences their association and genetic structure . Two sister genera of lichenized fungi Niebla and Vermilicinia are endemic to the fog deserts on the west coast of North America. Species of Trebouxia, a genus of green algae found worldwide, are the associated photobiont partners to the Niebla/Vermilicinia species complex. Recent work demonstrated that Niebla and Vermilicinia are highly specific for only a few closely related Trebouxia molecular species (OTUs). This project examines the diversity and broad specificity of algae with lichen …

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Decapod Sentience: Broadening The Framework, Cecilia De Souza Valente Jan 2022

Decapod Sentience: Broadening The Framework, Cecilia De Souza Valente

Animal Sentience

A framework for studying sentience in decapods is of great value, but how high a cost (in suffering) to each individual decapod (or any animal) is warranted for collecting scientific evidence of sentience? The lack of evidence for some of the target article’s proposed criteria surely results from the fact that research is focused mainly on biomedical studies, ecotoxicology, and commercial production, with decapod sentience and welfare seen as only a secondary research topic. I draw attention also to the possibility of a wider framework that includes all felt experiences, from suffering to pleasure.

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Independence, Weight And Priority Of Evidence For Sentience, Elizabeth Irvine Jan 2022

Independence, Weight And Priority Of Evidence For Sentience, Elizabeth Irvine

Animal Sentience

This commentary maps out relationships of dependency between the criteria proposed in the target article (Crump et al. 2022), identifying the criteria that carry most of the weight of the evidence, and suggesting which criteria should have priority in research on sentience.

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Sentience In Decapods: Difficulties To Surmount, Michael L. Woodruff Jan 2022

Sentience In Decapods: Difficulties To Surmount, Michael L. Woodruff

Animal Sentience

In the target article Crump et al. present 8 criteria to assess whether decapods experience pain. Four of these -- sensory integration, motivational trade-offs, flexible self-protection, and associative learning -- could be used to assess sentience in general. In this commentary I discuss difficulties with using these criteria to provide evidence of sentience in decapods, particularly if this evidence is to change public opinion and policies. These difficulties are lack of evidence, the potential to eventually explain the neurobiological basis of the behaviors chosen as criteria, thereby eliminating any explanatory work for sentience, and the reluctance to bring animals that …

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Pain In Pleocyemata, But Not In Dendrobranchiata?, Gary Comstock Jan 2022

Pain In Pleocyemata, But Not In Dendrobranchiata?, Gary Comstock

Animal Sentience

Crump et al.’s contribution to assessing whether decapods feel pain raises an important question: Is pain distributed unevenly across the order? The case for pain appears stronger in Pleocyemata than in Dendrobranchiata. Some studies report pain avoidance behaviors in Dendrobranchiata (Penaeidae) shrimp, but further studies are needed to determine whether the chemicals used are acting as analgesics to relieve pain, or as soporifics to reduce overall alertness. If the latter, the most farmed shrimp species may not require the same level of protection as crabs, crayfish, and lobsters.

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Sentience As Part Of Emotional Lives, Frans B. M. De Waal Jan 2022

Sentience As Part Of Emotional Lives, Frans B. M. De Waal

Animal Sentience

It is high time to explore the sentience of invertebrate animals, but this topic cannot be discussed without also exploring their emotional lives, including positive emotions. Sentience probably evolved to allow the regulation of emotions by endowing them with feelings.

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Decapod Sentience: Promising Framework And Evidence, Jon Mallatt, Todd E. Feinberg Md Jan 2022

Decapod Sentience: Promising Framework And Evidence, Jon Mallatt, Todd E. Feinberg Md

Animal Sentience

Strong points of the target article by Crump et al. are that it offers clear criteria for judging whether decapods are sentient, an effective semi-quantitative grading system for this purpose, and an astute, critical review of the literature. It concludes plausibly that major subgroups of decapods are sentient. A minor problem is that it includes classical, Pavlovian learning as a marker of sentience along with the more valid marker of complex (e.g., operant) learning. Another minor problem is that it does not distinguish results that are negative because of likely absence of sentience from results that are negative because they …

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Extending The Null Hypothesis To Invertebrate Pain Sentience, Eva Kakrada, Michael Colombo Jan 2022

Extending The Null Hypothesis To Invertebrate Pain Sentience, Eva Kakrada, Michael Colombo

Animal Sentience

In 1985 Macphail proposed his Null Hypothesis that there were no qualitative differences in intelligence across vertebrate species. A recent review of the literature has found overwhelming support for his view. Studies also suggest that, with respect to cognition and the neural mechanisms that support it, the Null Hypothesis should be extended to invertebrates. We suggest, on the same premise, that the Null Hypothesis should be extended to pain sentience in invertebrates. Although few studies have been conducted, behavioural and neural evidence for pain sentience has been found in various representative invertebrate species.

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Decapods As Food, Companions And Research Animals: Legal Impact Of Ascribing Sentience, Jonathan J. Cooper, Ambrose Tinarwo, Beth A. Ventura Jan 2022

Decapods As Food, Companions And Research Animals: Legal Impact Of Ascribing Sentience, Jonathan J. Cooper, Ambrose Tinarwo, Beth A. Ventura

Animal Sentience

This commentary provides an overview of the practical implications of attributing sentience to protect decapods as food, companion and research animals in the UK context. Recognising their capacity to suffer has implications for humane slaughter in farming and fishing sectors. It should also place a greater duty of care on owners of captive decapods, considering their needs and avoiding unnecessary suffering. The recognition of decapod sentience should also have an impact on their protection as research animals, although research with a potential to cause suffering may be needed to better understand decapods’ capacity to suffer.

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A Framework For Evaluating Evidence Of Pain In Animals, Matilda Gibbons, Lars Chittka Jan 2022

A Framework For Evaluating Evidence Of Pain In Animals, Matilda Gibbons, Lars Chittka

Animal Sentience

Crump et al. define eight criteria indicating sentience in animals, with a focus on pain. Here, we point out the risk of false negative or false positive diagnoses of pain. Criteria of different levels of inclusivity are useful for using the precautionary principle in animal welfare considerations, and for more formal scientific evidence of pain. We suggest tightening the criteria -- from more general evidence of sentience to pain alone -- because crucial evidence for animal welfare decisions might otherwise be missed for animals subjected to invasive and injurious procedures.

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Pros And Cons Of A Framework For Evaluating Potential Pain In Decapods, Robert W. Elwood Jan 2022

Pros And Cons Of A Framework For Evaluating Potential Pain In Decapods, Robert W. Elwood

Animal Sentience

The rigorous framework for research into potential pain in decapods was successful in allowing legislators in the United Kingdom to evaluate a complex scientific issue. However, it might produce problems for research. I discuss doubts about the usefulness of the eight criteria. Some have yet to receive any investigation and others do not allow much inference about pain. In addition, some existing studies are not covered in the framework. Most worrying, however, is the potential for stifling future research of novel areas that are excluded from the framework.

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Integrating Evolution Into The Study Of Animal Sentience, Walter Veit Jan 2022

Integrating Evolution Into The Study Of Animal Sentience, Walter Veit

Animal Sentience

Like many others, I see Crump et al. (2022) as a milestone for improving upon previous guidelines and for extending their framework to decapod crustaceans. Their proposal would benefit from a firm evolutionary foundation by adding the comparative measurement of life-history complexity as a ninth criterion for attributing sentience to nonhuman animals.

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Animal Sentience Research: Synthesis And Proposals, Andrew Crump, Heather Browning, Alex Schnell, Charlotte Burn, Jonathan Birch Jan 2022

Animal Sentience Research: Synthesis And Proposals, Andrew Crump, Heather Browning, Alex Schnell, Charlotte Burn, Jonathan Birch

Animal Sentience

Most commentaries on our target article broadly support our approach to evaluating evidence of animal sentience. In this Response, we clarify the framework’s purpose and address criticisms of our criteria. A recurring theme is that a framework to synthesise current evidence of sentience is not the same as an agenda for future directions in animal sentience research. Although future directions are valuable, our framework aims to evaluate existing evidence and inform animal welfare legislation.

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Wa Insecticide Guide 2022 - Autumn Winter, Amber Balfour-Cunningham, Dusty Severtson Jan 2022

Wa Insecticide Guide 2022 - Autumn Winter, Amber Balfour-Cunningham, Dusty Severtson

PestFacts WA

Registered chemicals for autumn and winter insect pests in Western Australian broadacre crops 2022.

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