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2021

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Human Plcg2 Haploinsufficiency Results In A Novel Immunodeficiency, Joshua Brandon Alinger Dec 2021

Human Plcg2 Haploinsufficiency Results In A Novel Immunodeficiency, Joshua Brandon Alinger

Arts & Sciences Graduate Student Theses and Dissertations

NK cells are critical for the recognition and lysis of herpesvirus-infected cells. Patients with NK cell immunodeficiency may suffer from unusually severe and/or recurrent herpesvirus infections; however, the genetic cause is frequently unknown. PLCG2 encodes a signaling protein in NK cell and B cell receptor signaling, in which dominant-negative or gain-of-function mutations may cause cold urticaria, antibody deficiency, or autoinflammation. However, loss-of-function mutations and PLCG2 haploinsufficiency have never been reported in human disease. We examined 2 families with autosomal dominant NK cell immunodeficiency with dual high-dimensional techniques, mass cytometry and whole-exome sequencing, to identify the cause of disease. We identified …

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A Study On The Hormonal Regulation And Novel Role Of Na+ Leak Channel, Non-Selective (Nalcn) In Human Myometrial Smooth Muscle Cells, Chinwendu Amazu Dec 2021

A Study On The Hormonal Regulation And Novel Role Of Na+ Leak Channel, Non-Selective (Nalcn) In Human Myometrial Smooth Muscle Cells, Chinwendu Amazu

Arts & Sciences Graduate Student Theses and Dissertations

During pregnancy, the uterus transitions from a quiescent state to an excitable, highly contractile state to deliver the fetus. Two important contributors essential for this transition are progesterone (P4) and estrogen (E2), which promote quiescence or contraction, respectively, by acting on the myometrial smooth muscle cells (MSMCs). While these hormones regulate uterine contractions, it is unclear how they affect electrical activity of MSMCs, which underlies uterine contractile activity. Our lab recently identified Na+ leak channel, non-selective (NALCN) as a component of the leak current in human MSMCs and showed that mice lacking NALCN in the uterus have dysfunctional labor. In …

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Slo2.1 Channels: A New Molecular Mechanism To Regulate Uterine Excitability, Juan Jose Ferreira Dec 2021

Slo2.1 Channels: A New Molecular Mechanism To Regulate Uterine Excitability, Juan Jose Ferreira

Arts & Sciences Graduate Student Theses and Dissertations

At the end of pregnancy, the uterus transitions from a non-contractile state to a highly contractile state. Two processes primarily drive this transition. First, from the 28th week of pregnancy until labor, the resting membrane potential of uterine (myometrial) smooth muscle cells (MSMCs) gradually becomes more positive (depolarizes) (Parkington et al. 1999). Second, at the end of pregnancy, MSMCs express more oxytocin receptors and become more sensitive to oxytocin (Kimura et al. 1996). However, the detailed mechanisms by which these processes occur have not been determined. My central hypothesis was that the Na+-activated K+ channel SLO2.1 plays a key role …

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Quantitative Characterization Of Microbial Ecologies In Dysbiosis And Infection, Eric Keen Dec 2021

Quantitative Characterization Of Microbial Ecologies In Dysbiosis And Infection, Eric Keen

Arts & Sciences Graduate Student Theses and Dissertations

In 1973, Theodosius Dobzhansky famously wrote that nothing in biology makes sense except in the light of evolution. Today, nearly 50 years later, little in microbiology – or in biology, for that matter – makes sense except in the light of genomics. Microbial genomics populates the field with innumerable testable hypotheses for evaluation in vitro and in vivo, allows us to monitor microbial populations in real time and at a massive scale, and underpins our approach to entire domains of microbiology, including microbial evolution. In this Thesis, I present three studies from my graduate research united by their common theme …

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Cancer Epigenome Reprogramming, Jennifer Ann Karlow Dec 2021

Cancer Epigenome Reprogramming, Jennifer Ann Karlow

Arts & Sciences Graduate Student Theses and Dissertations

The identification of recurrent genetic mutations in cancer and their functionalcharacterization has provided a strong foundation for our understanding of tumorigenesis. The more recent observation of recurrent and specific epigenetic changes also present in cancer has widened this view, now establishing cancer as a disease of both genetic and epigenetic misregulation. Enhancers, genomic regions primarily responsible for tissue-specific gene expression, have been shown to be frequent targets of both genetic and epigenetic abnormalities. The observation that DNA methylation within regulatory regions has traditionally correlated with reduced gene expression, coupled with the known role of enhancers in regulating tissuespecific gene expression, …

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The Effects Of Molecular Chaperone Modulation On Protein Folding, Prion Formation, And Prion Propagation In Saccharomyces Cerevisiae, Leeran Blythe Dublin Ryan Dec 2021

The Effects Of Molecular Chaperone Modulation On Protein Folding, Prion Formation, And Prion Propagation In Saccharomyces Cerevisiae, Leeran Blythe Dublin Ryan

Arts & Sciences Graduate Student Theses and Dissertations

Proper and efficient protein folding is vital for cell survival. Many factors affect protein folding fidelity and prion formation, including molecular chaperone availability and activity. Research has shown that modulating chaperone availability and function can affect protein misfolding and aggregation, as well as de novo prion formation and propagation. However, the factors involved and underlying mechanisms influencing prion formation and protein folding are largely unknown. The following work aims to elucidate these areas. The Nascent Polypeptide-Associated Complex (NAC) is the first point of chaperone contact for nascent polypeptides. Previous work has shown that disruption of the NAC leads to improved …

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Developments In Proteomics, Trans-Splicing Technology And Endogenous Transcript Manipulation, Justin Alexander Melendez Dec 2021

Developments In Proteomics, Trans-Splicing Technology And Endogenous Transcript Manipulation, Justin Alexander Melendez

Arts & Sciences Graduate Student Theses and Dissertations

Technological innovation drives scientific discovery, unlocks new avenues of research, and allows us to ask questions in ways that were previously unavailable. With each technological advance, our ability to perturb and explore biological systems has grown in ways previously unimagined. The theme of my thesis is the development of new technologies in biology. To this end, I have worked on three technologies that contribute to the areas of protein sequencing, RNA barcoding for trans-splicing and single-cell applications, and a new method for transcriptional knockdown. In my first project, digital analysis of proteins by end sequencing (DAPES), we set out to …

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Regulatory Effects Of The E. Coli Recbcd Nuclease Domain On Dna Unwinding Kinetics, Nicole Fazio Dec 2021

Regulatory Effects Of The E. Coli Recbcd Nuclease Domain On Dna Unwinding Kinetics, Nicole Fazio

Arts & Sciences Graduate Student Theses and Dissertations

I have examined the effects of deleting the nuclease domain of the E. coli helicase RecBCD on the rates of ATP-independent DNA melting, single stranded (ss) DNA translocation, and double stranded (ds) DNA unwinding by RecBCD. The canonical role of the nuclease domain is DNA degradation, but the removal of this domain showed unexpected effects on other RecBCD activities including DNA binding, melting, and unwinding. This thesis presents a mechanistic study of DNA unwinding by RecBCD and a RecBCD variant with the nuclease domain deleted (RecBΔnucCD). I examined the rates of ssDNA translocation and dsDNA unwinding by RecBCD and RecBΔnucCD …

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Weedy Rice As A Model System For The Study Of Microevolutionary Interactions In Agricultural Contexts, Marshall Jon Wedger Dec 2021

Weedy Rice As A Model System For The Study Of Microevolutionary Interactions In Agricultural Contexts, Marshall Jon Wedger

Arts & Sciences Graduate Student Theses and Dissertations

Just under one-half of the global population relies on cultivated rice (Oryza sativa) astheir primary source of calories, making the optimization of rice agriculture immensely important. One of the primary constraints to rice agriculture is the de-domesticated (feral) form of rice known as ‘weedy rice’ that aggressively competes for space, soil nutrients, and light. Heavy infestation can reduce crop yields by as much as 80%. As a closely-related weedy descendant of cultivated rice, chemical control is difficult in rice fields, and physical weeding is labor intensive, time consuming, and largely ineffective due to early life-stage mimicry of the crop. Weedy …

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Genetic Risk Factors For Neurodevelopmental Disorders: Insights From Hipsc-Cerebral Organoids, Michelle L. Wegscheid Dec 2021

Genetic Risk Factors For Neurodevelopmental Disorders: Insights From Hipsc-Cerebral Organoids, Michelle L. Wegscheid

Arts & Sciences Graduate Student Theses and Dissertations

Neurofibromatosis type 1 (NF1) is a common neurodevelopmental disorder (NDD) characterized by remarkable phenotypic variability, where affected children manifest a spectrum of central nervous system (CNS) abnormalities, including brain tumors, impairments in attention, behavior, learning disabilities, and an increased incidence of autism spectrum disorder (ASD). A significant barrier to the implementation of precision medicine strategies for children with NF1 is a lack of prognostic risk factors to guide clinical management. However, emerging population-based genotype-phenotype association studies have suggested that the germline NF1 gene mutation may represent one clinically actionable risk factor for NF1-associated neurodevelopmental abnormalities. As a critical step in …

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Surveillance And Dynamics Of Bacteria And Resistance Genes In Humans And Hospitals, Alaric Wences D'Souza Dec 2021

Surveillance And Dynamics Of Bacteria And Resistance Genes In Humans And Hospitals, Alaric Wences D'Souza

Arts & Sciences Graduate Student Theses and Dissertations

Bacteria live in, on, and around us. These bacteria affect human health through beneficial commensal interactions that promote normal development and through harmful infections or perturbations leading to disease. Understanding the prevalence, spread, and resilience of these bacteria in humans and human environments is critical to clinical medicine and epidemiology. I investigated environmental and human resident bacteria to understand dynamics in bacterial communities and how these dynamics may impact human health.Hospitals are one critical location of human-bacterial interactions. Bacteria can contaminate hospital surfaces from patients or environmental sources and subsequently transmit from surfaces to vulnerable patients. I analyzed bacteria from …

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Dissecting The Molecular Mechanism Of Familial Cardiomyopathies, Sarah Ruth Clippinger Schulte Dec 2021

Dissecting The Molecular Mechanism Of Familial Cardiomyopathies, Sarah Ruth Clippinger Schulte

Arts & Sciences Graduate Student Theses and Dissertations

Familial cardiomyopathies, including hypertrophic (HCM), restrictive (RCM) and dilated cardiomyopathy (DCM), are the leading cause of sudden cardiac death in young people. These diseases, which are characterized by altered cardiac contractility and remodeling of the heart, can lead to heart failure. These diseases are primarily caused by point mutations in sarcomeric proteins that generate or regulate heart contraction, such as troponin T. In the heart, the troponin complex together with tropomyosin lie along the actin filament and regulate myosin’s ability to bind actin and produce force. Here I show how mutations in troponin T affect contractility at the molecular level …

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Influence Of Aging And Cerebrovascular Disease On Neuroimaging Measures Of Alzheimer Disease, Lauren Nicole Koenig Dec 2021

Influence Of Aging And Cerebrovascular Disease On Neuroimaging Measures Of Alzheimer Disease, Lauren Nicole Koenig

Arts & Sciences Graduate Student Theses and Dissertations

The overall goal of this dissertation is to gain a better understanding of how Alzheimer disease relates to normal aging and cerebrovascular disease to impact neuroimaging measures in a clinically meaningful way. Both aging and cerebrovascular disease are known to influence measures of Alzheimer disease, making it difficult to separate what changes are attributable specifically to Alzheimer disease. We hypothesize that a better understanding of these relationships will allow future studies to appropriately take these factors into account. In Chapters 2 and 3 we attempt to separate out the influences of normal aging and Alzheimer disease on measures of atrophy. …

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Identification Of Multi-Tissue Protein Quantitative Trait Loci And Causal Inference Of Protein Effects In Neurological And Other Complex Human Diseases Via Mendelian Randomization, Chengran Yang Dec 2021

Identification Of Multi-Tissue Protein Quantitative Trait Loci And Causal Inference Of Protein Effects In Neurological And Other Complex Human Diseases Via Mendelian Randomization, Chengran Yang

Arts & Sciences Graduate Student Theses and Dissertations

Alzheimer disease (AD) is the most common neurodegenerative disease, affecting 6.2 million people mostly aged 65 years or older in the United States as of early 2021. AD has been widely studied and characterized worldwide, but there is still no effective treatment or cure. Even the latest FDA-approved treatment, Aducanumab, cannot stop decline or improve cognition. To develop a truly effective treatments, researchers keep discovering genetic and molecular mechanisms underlying the disease. Protein biomarkers are keys to bridge the mechanisms to disease. Here, I first used a high-throughput proteomic dataset from three tissues (CSF, plasma, and brain) with array-based genotype …

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Iron And Manganese Oxidation By Oxyhalogen Species: Implications For Paleoenvironmental Reconstruction On Mars, Kaushik Mitra Dec 2021

Iron And Manganese Oxidation By Oxyhalogen Species: Implications For Paleoenvironmental Reconstruction On Mars, Kaushik Mitra

Arts & Sciences Graduate Student Theses and Dissertations

As the nearest planetary neighbor with potential earlier habitable conditions, Mars is replete with minerals that hold clues to its past chemistry and evolution of the aqueous systems. Oxidized iron (Fe) and manganese (Mn) minerals on Mars are geochemical markers of such environments in which they formed and record past pH, redox conditions, and intensity of water-rock interaction. Fe and Mn oxides can therefore be used to reconstruct past Martian environmental conditions from settings where aqueous fluids were active. Various processes that form Fe and Mn oxide minerals on Mars have been previously proposed, including chemical oxidation using molecular oxygen …

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On Arousal And The Internal Regulation Of Brain Function: Theory And Evidence Across Modalities And Species, Ryan Raut Dec 2021

On Arousal And The Internal Regulation Of Brain Function: Theory And Evidence Across Modalities And Species, Ryan Raut

Arts & Sciences Graduate Student Theses and Dissertations

The brain is an organ. It is subject to the same physiological regulatory processes that engage the rest of the body’s organs, sculpted over hundreds of millions of years to sustain life so effectively. The central message of this thesis is that the holistic functioning of the brain, rather than operating at some level above or independent from these systemic regulatory processes, is deeply related to them. In short, as our limited attention spans might suggest: brain function is internally regulated. I propose that this internal regulation is a primary function of intrinsic brain activity. Chapter 2 provides a theoretical …

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Multicenter Randomized Phase Ii Trial Of Atezolizumab With Or Without Cobimetinib In Biliary Tract Cancers, Mark Yarchoan, Andrea Wang-Gillam, Et Al Dec 2021

Multicenter Randomized Phase Ii Trial Of Atezolizumab With Or Without Cobimetinib In Biliary Tract Cancers, Mark Yarchoan, Andrea Wang-Gillam, Et Al

Open Access Publications

BACKGROUNDMEK inhibitors have limited activity in biliary tract cancers (BTCs) as monotherapy but are hypothesized to enhance responses to programmed death ligand 1 (PD-L1) inhibition.METHODSThis open-label phase II study randomized patients with BTC to atezolizumab (anti-PD-L1) as monotherapy or in combination with cobimetinib (MEK inhibitor). Eligible patients had unresectable BTC with 1 to 2 lines of prior therapy in the metastatic setting, measurable disease, and Eastern Cooperative Oncology Group (ECOG) performance status less than or equal to 1. The primary endpoint was progression-free survival (PFS).RESULTSSeventy-seven patients were randomized and received study therapy. The trial met its primary endpoint, with a …

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A Large West Antarctic Ice Sheet Explains Early Neogene Sea-Level Amplitude, J. W. Marschalek, L. Zurli, F. Talarico, De Flierdt T Van, P. Vermeesch, A. Carter, F Beny, V. Bout-Roumazeilles, F. Sangiorgi, S. R. Hemming, L. F. Pérez, F. Colleoni, J. G. Prebble, Peer Te Van, M. Perotti, A. E. Shevenell, I Browne, Dk Kulhanek, R. Levy, D Harwood, N. B. Sullivan, S. R. Meyers, E. M. Griffith, C. D. Hillenbrand, E. Gasson, M. J. Siegert, B Keisling, K. J. Licht, G. Kuhn, Jp Dodd, C. Boshuis, Santis L De, Rm Mckay, Jeanine Ash, F Beny, Im Browne, Giuseppe Cortese, Santis L De, Jp Dodd, Oliver M. Esper, Jenny A. Gales, Dm Harwood, Saki Ishino, Ba Keisling, S Kim, S Kim, Dk Kulhanek, Jan Sverre Laberg, R. Mark Leckie, Rm Mckay, J Müller, Mo Patterson, Bw Romans, Oe Romero, F. Sangiorgi, O Seki, Ae Shevenell, Sm Singh, De Sousa Im Cordeiro, St Sugisaki, T Van De Flierdt, Peer Te Van, W Xiao, Z Xiong Dec 2021

A Large West Antarctic Ice Sheet Explains Early Neogene Sea-Level Amplitude, J. W. Marschalek, L. Zurli, F. Talarico, De Flierdt T Van, P. Vermeesch, A. Carter, F Beny, V. Bout-Roumazeilles, F. Sangiorgi, S. R. Hemming, L. F. Pérez, F. Colleoni, J. G. Prebble, Peer Te Van, M. Perotti, A. E. Shevenell, I Browne, Dk Kulhanek, R. Levy, D Harwood, N. B. Sullivan, S. R. Meyers, E. M. Griffith, C. D. Hillenbrand, E. Gasson, M. J. Siegert, B Keisling, K. J. Licht, G. Kuhn, Jp Dodd, C. Boshuis, Santis L De, Rm Mckay, Jeanine Ash, F Beny, Im Browne, Giuseppe Cortese, Santis L De, Jp Dodd, Oliver M. Esper, Jenny A. Gales, Dm Harwood, Saki Ishino, Ba Keisling, S Kim, S Kim, Dk Kulhanek, Jan Sverre Laberg, R. Mark Leckie, Rm Mckay, J Müller, Mo Patterson, Bw Romans, Oe Romero, F. Sangiorgi, O Seki, Ae Shevenell, Sm Singh, De Sousa Im Cordeiro, St Sugisaki, T Van De Flierdt, Peer Te Van, W Xiao, Z Xiong

School of Biological and Marine Sciences

Early to Middle Miocene sea-level oscillations of approximately 40–60 m estimated from far-field records are interpreted to reflect the loss of virtually all East Antarctic ice during peak warmth2. This contrasts with ice-sheet model experiments suggesting most terrestrial ice in East Antarctica was retained even during the warmest intervals of the Middle Miocene. Data and model outputs can be reconciled if a large West Antarctic Ice Sheet (WAIS) existed and expanded across most of the outer continental shelf during the Early Miocene, accounting for maximum ice-sheet volumes. Here we provide the earliest geological evidence proving large WAIS expansions occurred during …

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On The Variability Of Flocculated Particle Characteristics In A Shallow Estuary, G Egan, G Chang, Aj Manning, Sg Monismith, Ob Fringer Dec 2021

On The Variability Of Flocculated Particle Characteristics In A Shallow Estuary, G Egan, G Chang, Aj Manning, Sg Monismith, Ob Fringer

School of Biological and Marine Sciences

No abstract provided.

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Transcriptional Reprogramming Differentiates Active From Inactive Esr1 Fusions In Endocrine Therapy-Refractory Metastatic Breast Cancer, Xuxu Gou, Shunqiang Li, Et Al. Dec 2021

Transcriptional Reprogramming Differentiates Active From Inactive Esr1 Fusions In Endocrine Therapy-Refractory Metastatic Breast Cancer, Xuxu Gou, Shunqiang Li, Et Al.

2020-Current year OA Pubs

Genomic analysis has recently identified multiple

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Regulation Of Metabolic Stress By The Snhg3 Locus, Arthur Curtis Sletten Dec 2021

Regulation Of Metabolic Stress By The Snhg3 Locus, Arthur Curtis Sletten

Arts & Sciences Graduate Student Theses and Dissertations

Dyslipidemia and lipotoxicity are pathologic signatures of the metabolic syndrome and type 2 diabetes. Excess lipid causes cell dysfunction and induces cell death through pleiotropic mechanisms that link to oxidative stress. However, pathways that regulate the response to metabolic stress are not fully understood. To identify novel genes involved in metabolic stress, our group performed an unbiased forward genetic screen for lipotoxicity resistance. My studies focused on characterizing one of the mutant cell lines isolated from this screen, in which promoter trap mutagenesis disrupted one allele of the small nucleolar RNA hosting gene 3 (Snhg3). I demonstrate that diminished expression …

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Structural Stability Of Short Latency Alfalfa-Based Pastures In The Humid Pampa, Argentina, R. O. Refi, B. Martín Dec 2021

Structural Stability Of Short Latency Alfalfa-Based Pastures In The Humid Pampa, Argentina, R. O. Refi, B. Martín

IGC Proceedings (1977-2023)

The aim of this study was to search the effects of grazing intensity and nitrogen fertilization on the structural stability of a mixed pasture composed by alfalfa (latency group 9), brome grass, tall fescue and white clover, sown in April 1997. Rotational grazing was carried out with dairy cattle with high intensity (HI: up to 3-4 cm) or moderate intensity (LI: up to 8-10 cm), whenever the alfalfa showed basal regrowth. According to a split-plot design, grazing intensities were subdivided to assign three levels of nitrogen fertilization: N0, without fertilization; N1 with 50 kg N/ha per year; and N2 with …

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Late Winter Dietary Overlap Among Greater Rheas And Domestic Herbivores On The Argentinean Flooding Pampa, G. Vacarezza, M. S. Cid, F. Milano Dec 2021

Late Winter Dietary Overlap Among Greater Rheas And Domestic Herbivores On The Argentinean Flooding Pampa, G. Vacarezza, M. S. Cid, F. Milano

IGC Proceedings (1977-2023)

This study evaluates the dietary overlap among greater rheas (Rhea americana L.) sheep and cattle in the Flooding Pampa, Buenos Aires, Argentina during late winter, when is observed the lowest forage availability. The work was carried out with the following forage classes (FC): warm and cool season grasses and forbs (legumes and no-legumes). Diet botanical composition was estimated by microanalysis of faeces. Principal Component Analysis and Kulcyznsky´s index of similarity were used for data analysis. Rhea populations selected diets with higher forb percentages. On the contrary, vegetation structure and their own morpho-physiology conditioned cattle to diets almost exclusively gramineous. …

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Beef Calf Production Using Year-Round Grazing On Tropical Grass Pasture In Summer Combined With Cool Temperate Grass Pasture In Winter, Y. Nakanishi, K. Shindou, S. Watanabe, K. Yamamoto, K. Hagino Dec 2021

Beef Calf Production Using Year-Round Grazing On Tropical Grass Pasture In Summer Combined With Cool Temperate Grass Pasture In Winter, Y. Nakanishi, K. Shindou, S. Watanabe, K. Yamamoto, K. Hagino

IGC Proceedings (1977-2023)

Bahiagrass (Paspalum notatum Fluegge) showed a poor quality with low crude protein in summer but blood biochemical levels of grazing beef cows were similar to drylot feeding cows except of concentration of urea nitrogen. Italian ryegrass (Lolium multiflorum Lam) showed very good quality with high crude protein (about 20 percentage) in winter. And so, suckler cows gained live weight in winter and suckling calves were showed very high growth rate (daily gain was about 1.0 kg). Total live weight gains of grazing cows were higher than those of drylot feeding cows. Postpartum reproductive performances of grazing cows were …

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Winter Grazing And Feeding Systems In Western Canada, Duane H. Mccartney, V. Baron, J. Basarab, E. Okine, G. Lastiwka, A. Depalme, D. Young Dec 2021

Winter Grazing And Feeding Systems In Western Canada, Duane H. Mccartney, V. Baron, J. Basarab, E. Okine, G. Lastiwka, A. Depalme, D. Young

IGC Proceedings (1977-2023)

Beef cow calf producers in Western Canada are looking for methods of extending the grazing season into the winter in order to lower winter feed costs. Dry beef cows were early or late weaned and grazed during the early months of winter on late seeded barley swaths (Hardlum vulgare L.) and compared to cows fed barley silage and free choice barley straw in a feeding yard. The swath grazed barley was late seeded in June and swathed in the silage stage in mid September. Cows successfully swath grazed for three winters from mid November until mid to late February …

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Forage Management For Extending The Grazing Season, David W. Koch, C. M. Lux, J. W. Flake Dec 2021

Forage Management For Extending The Grazing Season, David W. Koch, C. M. Lux, J. W. Flake

IGC Proceedings (1977-2023)

Studies were conducted to determine ways to extend grazing season with forages adequate to meet the needs of grazing animals and to reduce the cost of livestock production. Perennial grasses were swathed, windrowed and left in the field until they were winter-grazed with bred heifers. Corn (Zea mays L.) was stockpiled for winter grazing with lambs and ewes. Windrowed grasses increased in acid detergent fiber (ADF) and neutral detergent fiber (NDF) compared with stored hay, but crude protein content, heifer weight gain and body condition change was similar for both forages. An economic value of $218 ha-1 from …

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Molecular Cartography Of Residue Pesticides On Grape Surface In 3d By Ambient Ionization Tandem Mass Spectrometry, Hung Su, Tiao-Lai Huang, Cheng-Ting Chi, Yi-Tzu Cho, Chi-Wei Lee, Jingyueh Jeng, Jentaie Shiea Dec 2021

Molecular Cartography Of Residue Pesticides On Grape Surface In 3d By Ambient Ionization Tandem Mass Spectrometry, Hung Su, Tiao-Lai Huang, Cheng-Ting Chi, Yi-Tzu Cho, Chi-Wei Lee, Jingyueh Jeng, Jentaie Shiea

Journal of Food and Drug Analysis

Thermal desorption-electrospray ionization tandem mass spectrometry (TD-ESI/MS/MS) was used to characterize the residual pesticides that were collected from the surface of a grape with metallic sampling probes. Fungicides, insecticides, and miticides were detected, where results were validated by simple solvent extraction followed by gas chromatography tandem mass spectrometry and liquid chromatography tandem mass spectrometry analyses. To explore the distribution of pesticide residues on grape surfaces, 149 locations of a grape surface were collected and followed by TD-ESI/MS/MS analysis. The molecular cartography was then generated from analysis of residual pesticides on the grape surface in 3D.

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Variations In Bovine Milk Oligosaccharides After Calving Using P-Aminobenzoic Ethyl Ester Closed-Ring Labeling And Negative Ion Electrospray Lc/Ms/Ms, Han-Ju Chien, Yi-Chun Ma, Yi-Feng Zheng, Cheng-Yu Kuo, Wei-Chen Wang, Guor-Rong Her, Chien-Chen Lai Dec 2021

Variations In Bovine Milk Oligosaccharides After Calving Using P-Aminobenzoic Ethyl Ester Closed-Ring Labeling And Negative Ion Electrospray Lc/Ms/Ms, Han-Ju Chien, Yi-Chun Ma, Yi-Feng Zheng, Cheng-Yu Kuo, Wei-Chen Wang, Guor-Rong Her, Chien-Chen Lai

Journal of Food and Drug Analysis

A strategy was proposed to analyze bovine milk oligosaccharides using p-aminobenzoic ethyl ester (ABEE) closed-ring labeling and C18 capillary liquid chromatography negative ion electrospray tandem mass spectrometry. Linkage specific fragment ions were used to identify oligosaccharide isomers. By constructing the mass chromatograms using linkage specific fragment ions, isomers were differentiated based on m/z values as well as temporal separation provided by liquid chromatography. In addition to disialyllactose and the single isomer lacto-N-neohexaose, four pairs of linkage isomers including 3’/6’-sialyllactose (3’/6’-SL), 3’/6’-sialyllactosamine (3’/6’-SLN), 3’/6’-sialylgalactosyl-lactose (3’/6’-SGL), and lacto-N-tetraose/lacto-N-neotetraose (LNT/LNnT) in bovine milk were investigated. Variations of bovine milk oligosaccharides in a …

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Determination Of Quetiapine And Its Metabolites In Plasma By Field-Enhanced Sample Stacking, Tai-Ling Liu, Li-Shan Fang, Jing-Ru Liou, Jia-Shan Dai, Yen-Ling Chen Dec 2021

Determination Of Quetiapine And Its Metabolites In Plasma By Field-Enhanced Sample Stacking, Tai-Ling Liu, Li-Shan Fang, Jing-Ru Liou, Jia-Shan Dai, Yen-Ling Chen

Journal of Food and Drug Analysis

Quetiapine is an atypical antipsychotic drug that can be used to treat mental disorders, including schizophrenia, bipolar disorder and Alzheimer's disease. Quetiapine is mainly converted into the active metabolites of norquetiapine and 7-hydroxyquetiapine by the liver enzymes CYP3A4 and CYP2D6. In this study, liquid-liquid extraction (LLE) was used as a sample pretreatment method to eliminate interferences in plasma. tert-Butyl methyl ether was chosen as the extraction solvent. Field-enhanced sample injection (FESS), an online preconcentration technique, was used to analyze quetiapine and its metabolites norquetiapine and 7-hydroxyquetiapine in plasma. The optimal separation condition was 120 mM phosphate (pH 4.0) containing …

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Diagnostic Ions Guided 2d-Locating Strategy For Characterization Of Chemical Analogues In Complex Herbal Medicines Using Liquid Chromatography-Ion Mobility-Mass Spectrometry, Meng-Ning Li, Zi-Xuan Zhang, Hui-Ying Wang, Wen Gao, Ping Li, Hua Yang Dec 2021

Diagnostic Ions Guided 2d-Locating Strategy For Characterization Of Chemical Analogues In Complex Herbal Medicines Using Liquid Chromatography-Ion Mobility-Mass Spectrometry, Meng-Ning Li, Zi-Xuan Zhang, Hui-Ying Wang, Wen Gao, Ping Li, Hua Yang

Journal of Food and Drug Analysis

Rapid characterization of chemical analogues in potentially toxic complex matrix was essential for prevention of accidental poisoning. On the basis of the fragment ions possessed not only the same retention times (RT) but the same drift times (DT) on liquid chromatography-ion mobility-mass spectrometry (LC-IM-MS), an alternating frames (AF)-data independent acquisition (DIA) was utilized for simultaneous detection and rapid match of precursor/product ions with a fast switch of low/high collision energy (CE). A diagnostic ions guided 2D-locating strategy was developed for identification of chemical analogues in potentially toxic herbal medicines using LC-IM-MS. Firstly, the 2D-locations (RT, DT) of diagnostic ions were …

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