Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons™

Open Access. Powered by Scholars. Published by Universities.®

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 58531 - 58560 of 256037

Full-Text Articles in Life Sciences

Likely Community Transmission Of Covid-19 Infections Between Neighboring, Persistent Hotspots In Ontario, Canada, Ben C. Shirley, Eliseos J. Mucaki, Peter Rogan Dec 2021

Likely Community Transmission Of Covid-19 Infections Between Neighboring, Persistent Hotspots In Ontario, Canada, Ben C. Shirley, Eliseos J. Mucaki, Peter Rogan

Biochemistry Publications

Introduction: This study aimed to produce community-level geo-spatial mapping of confirmed COVID-19 cases in Ontario Canada in near real-time to support decision-making. This was accomplished by area-to-area geostatistical analysis, space-time integration, and spatial interpolation of COVID-19 positive individuals.
Methods: COVID-19 cases and locations were curated for geostatistical analyses from March 2020 through June 2021, corresponding to the first, second, and third waves of infections. Daily cases were aggregated according to designated forward sortation area (FSA), and postal codes (PC) in municipal regions Hamilton, Kitchener/Waterloo, London, Ottawa, Toronto, and Windsor/Essex county. Hotspots were identified with area-to-area tests including Getis-Ord Gi*, Global …


Influence Of Prolonged Serotonin And Ergovaline Pre-Exposure On Vasoconstriction Ex Vivo, Eriton E. L. Valente, David L. Harmon, James L. Klotz Dec 2021

Influence Of Prolonged Serotonin And Ergovaline Pre-Exposure On Vasoconstriction Ex Vivo, Eriton E. L. Valente, David L. Harmon, James L. Klotz

Animal and Food Sciences Faculty Publications

Ergot alkaloid mycotoxins interfere in many functions associated with serotonergic neurotransmitters. Therefore, the objective was to evaluate whether the association of serotonin (5-hydroxytryptamine, 5-HT) and ergot alkaloids during a 24 h pre-incubation could affect the vascular contractile response to ergot alkaloids. To evaluate the effects of 24 h exposure to 5-HT and ergot alkaloids (ergovaline, ERV), two assays were conducted. The first assay determined the half-maximal inhibitory concentration (IC50)following the 24 h pre-exposure period, while the second assay evaluated the effect of IC50 concentrations of 5-HT and ERV either individually or in combination. There was an interaction …


Affective Computing For Late-Life Mood And Cognitive Disorders, Erin Smith, Eric A. Storch, Ipsit Vahia, Stephen T.C. Wong, Helen Lavretsky, Jeffrey L. Cummings, Harris A. Eyre Dec 2021

Affective Computing For Late-Life Mood And Cognitive Disorders, Erin Smith, Eric A. Storch, Ipsit Vahia, Stephen T.C. Wong, Helen Lavretsky, Jeffrey L. Cummings, Harris A. Eyre

Brain Health Faculty Research

Affective computing (also referred to as artificial emotion intelligence or emotion AI) is the study and development of systems and devices that can recognize, interpret, process, and simulate emotion or other affective phenomena. With the rapid growth in the aging population around the world, affective computing has immense potential to benefit the treatment and care of late-life mood and cognitive disorders. For late-life depression, affective computing ranging from vocal biomarkers to facial expressions to social media behavioral analysis can be used to address inadequacies of current screening and diagnostic approaches, mitigate loneliness and isolation, provide more personalized treatment approaches, and …


Linguistic Variation From Cognitive Variability: The Case Of English 'Have', Muye Zhang Dec 2021

Linguistic Variation From Cognitive Variability: The Case Of English 'Have', Muye Zhang

Linguistics Graduate Dissertations

In this dissertation, I seek to construct a model of meaning variation built upon variability in linguistic structure, conceptual structure, and cognitive makeup, and in doing so, exemplify an approach to studying meaning that is both linguistically principled and neuropsychologically grounded. As my test case, I make use of the English lexical item ‘have' by proposing a novel analysis of its meaning based on its well-described variability in English and its embed- ding into crosslinguistically consistent patterns of variation and change.

I support this analysis by investigating its real-time comprehension patterns through behavioral, electropsychophysiological, and hemodynamic brain data, thereby incorporating …


Nutritional And Physiological Constraints Contributing To Limitations In Small Intestinal Starch Digestion And Glucose Absorption In Ruminants, Ronald J. Trotta, David L. Harmon, James C. Matthews, Kendall C. Swanson Dec 2021

Nutritional And Physiological Constraints Contributing To Limitations In Small Intestinal Starch Digestion And Glucose Absorption In Ruminants, Ronald J. Trotta, David L. Harmon, James C. Matthews, Kendall C. Swanson

Animal and Food Sciences Faculty Publications

Increased efficiency of nutrient utilization can potentially be gained with increased starch digestion in the small intestine in ruminants. However, ruminants have quantitative limits in the extent of starch disappearance in the small intestine. The objective is to explore the nutritional and physiological constraints that contribute to limitations of carbohydrate assimilation in the ruminant small intestine. Altered digesta composition and passage rate in the small intestine, insufficient pancreatic α-amylase and/or small intestinal carbohydrase activity, and reduced glucose absorption could all be potentially limiting factors of intestinal starch assimilation. The absence of intestinal sucrase activity in ruminants may be related to …


The Carrying Capacity Of Pure And Oversown Giant Star Grass (Cynodon Nlemfuensis Vanderyst) Under Different Stocking Rate In South-Western Islands Of Japan, Yasuhiro Kawamoto, T. Namihira, Y. Imura, M. Nagano Dec 2021

The Carrying Capacity Of Pure And Oversown Giant Star Grass (Cynodon Nlemfuensis Vanderyst) Under Different Stocking Rate In South-Western Islands Of Japan, Yasuhiro Kawamoto, T. Namihira, Y. Imura, M. Nagano

IGC Proceedings (1977-2023)

The objective of this study was firstly to know the potential carrying capacity, pasture production, pasture utilization of giant star grass under different stocking rates in intensive rotational grazing system, and to evaluate a carrying capacity of giant star grass (Cynodon nlemfuensis Vanderyst) pasture oversown with annual hybrid ryegrass (Lolium multiflorum X Lolium perenne) on short low productive winter pasture in South-western Islands of Japan. High herbage availability and good quality forage to bring about effective animal productions were produced by using relatively heavy stocking rates of 6 - 8 heads/ha, and achieved optimum pasture utilization of …


Residual Forage And Animal Performance From A Kikuyo Pasture Under Mixed Grazing And Supplementation, F. C. Gómez-Merino, Pedro A. Martínez-Hernández, J. Pérez-Pérez, Alfonso Hernández-Garay Dec 2021

Residual Forage And Animal Performance From A Kikuyo Pasture Under Mixed Grazing And Supplementation, F. C. Gómez-Merino, Pedro A. Martínez-Hernández, J. Pérez-Pérez, Alfonso Hernández-Garay

IGC Proceedings (1977-2023)

Five grazing strategies were compared: grazing by ewes only and mixed grazing (ewes + heifers), in mixed grazing heifers received no supplement or one of three supplements. Ruminal undegradable protein (RUP) varied among supplement: 4.25, 9.11 and 9.13%, the supplement with the highest RUP included protected methionine. All supplements were 21% crude protein and 3.0 Mcal/kg of metabolizable energy. Grazing was on kikuyu, ratio was 30 kg of ewe per 100 kg of heifer in the mixed grazing treatments. Experimental grazing lasted 84 days. Variables measured were residual forage, proline content in residual forage and liveweight gains per animal and …


Stubble Height Effects On Limpograss Pasture Characteristics And Performance Of Beef Heifers, Y. C. Newman, Lynn E. Sollenberger, W. E. Kunkle, D. B. Bates, C. G. Chambliss, A. M. Fox Dec 2021

Stubble Height Effects On Limpograss Pasture Characteristics And Performance Of Beef Heifers, Y. C. Newman, Lynn E. Sollenberger, W. E. Kunkle, D. B. Bates, C. G. Chambliss, A. M. Fox

IGC Proceedings (1977-2023)

Limpograss (Hemarthria altissima [Poir.] Stapf. & C.E. Hubb.) is a C4 species used in Florida beef production systems because of its cool-season growth, persistence on poorly drained soils, and high yield and digestibility. Animal performance on limpograss pastures, however, has been limited by low herbage crude protein (CP). This study evaluated the effect of canopy height of limpograss pastures and N supplementation of grazing cattle on sward characteristics and weight gain and blood urea N (BUN) concentration of yearling beef heifers. Under continuous stocking, six treatments were imposed that included all combinations of three stubble heights (20, 40, …


The Duration Of Regrowth Period And The Structural Traits In A Rotationally Grazed Panicum Maximum Sward, Carlos A. M. Gomide, J. A. Gomide Dec 2021

The Duration Of Regrowth Period And The Structural Traits In A Rotationally Grazed Panicum Maximum Sward, Carlos A. M. Gomide, J. A. Gomide

IGC Proceedings (1977-2023)

Panicum maximum 'cv'. Mombaça was rotationally grazed by steers. Three regrowth periods based on the number of expanded leaves per tiller: 2.5; 3.5 and 4.5, were compared. Three groups of seven tester steers, one for each treatment, grazed the replications of each experimental paddocks, the animals being removed from a paddock after 4 to 5 day grazing period when its sward leaf area index (LAI) was 1.5, on the average. Sward height and available biomass increased while tiller population density and leaf-stem ratio decreased with regrowth period. Overall averages observed for LAI and photosyntheticly active radiation interception by the end …


Effect Of Different Strategies Of Management Of Elephantgrass On Pasture Availability And Milk Yield Of Crossbred Holstein X Zebu Cows, Fermino Deresz Dec 2021

Effect Of Different Strategies Of Management Of Elephantgrass On Pasture Availability And Milk Yield Of Crossbred Holstein X Zebu Cows, Fermino Deresz

IGC Proceedings (1977-2023)

The trial was done to study different strategies of pasture management on milk production of cows grazing Elephantgrass (Pennisetum purpureum, Schum.). The treatments were: Elephantgrass with 30 days of resting and fertilized monthly (30MF), fertilized every two months (30BF). Elephantgrass with 45 days of resting and a stubble height of 90-100 cm (45HS) or a stubble height of 40-50 cm (45LS). The stubble height for treatments 30MF and 30BF was 90-100 cm. The study was done using six crossbred Holstein x Zebu cows/treatment, with 100 days of lactation, on average. The experimental design was a completely randomized block …


Status And Relative Abundance Of Alabama Shad, Alosa Alabamae, In Alabama, Steven J. Rider, Travis R. Powell, Jason E. Dattilo, Gregory T. Miles Dec 2021

Status And Relative Abundance Of Alabama Shad, Alosa Alabamae, In Alabama, Steven J. Rider, Travis R. Powell, Jason E. Dattilo, Gregory T. Miles

Southeastern Fishes Council Proceedings

Alabama Shad, Alosa alabamae, an anadromous fish found historically from the Mississippi River basin eastward to the Suwanee River, has experienced population declines and even extirpation in some States. In Alabama, A. alabamae have been found in rivers of the Mobile River basin and Conecuh, Yellow, and Choctawhatchee rivers in the coastal Gulf Plain. We report on our directed and targeted efforts to assess the current status and relative abundance of A. alabamae in Alabama and compare our results to past A. alabamae surveys in Alabama. We completed 52 sampling trips and expended 129.5 hours of boat-electrofishing effort targeting …


Evaluation Of Salmonella Biofilm Cell Transfer From Common Food Contact Surfaces To Beef Products, Rong Wong, David A. King, Norasak Kalchayanand Dec 2021

Evaluation Of Salmonella Biofilm Cell Transfer From Common Food Contact Surfaces To Beef Products, Rong Wong, David A. King, Norasak Kalchayanand

Roman L. Hruska U.S. Meat Animal Research Center: Reports

Meat contamination by Salmonella enterica is a serious public health concern. Available data have suggested that biofilm formation at processing plants and contaminated contact surfaces might contribute to meat contamination. Because transfer from contact surfaces to food products via direct contact has been deemed the most common bacteria transmission route that can lead to contamination, we evaluated the effect of Salmonella biofilm forming ability, contact surface material, and beef surface tissue type on Salmonella biofilm transfer from hard surfaces to beef products. Salmonella biofilms developed on the common contact surfaces stainless steel (SS) and polyvinylchloride (PVC) were transferred consecutively via …


A Comparison Of The Effects Of Heat Therapy And Exercise Training On Vascular Function During Passive And Active Exercise, Taysom Erica Wallace Dec 2021

A Comparison Of The Effects Of Heat Therapy And Exercise Training On Vascular Function During Passive And Active Exercise, Taysom Erica Wallace

Theses and Dissertations

Recent evidence suggests that heat, a major byproduct of exercise, may be the mediator for many vascular adaptations that come from exercise. Thus, heat therapy that increases muscle temperature in a comparable way to exercise may be an advantageous alternative for enhancing cardiovascular health in individuals where treatment with exercise is either not possible or undesired. PURPOSE: Compare the effects of exercise and heat training on resistance artery function at rest and during exercise. METHODS: Thirty-five (18 female) healthy, untrained subjects completed a 6-week training program utilizing either high intensity knee extension (KE) exercise (40 min), localized heat therapy (pulsed …


Evaluating Apoptosis, Autophagy, And Hormonal Effects On Oocyte Regulation And Cyst Breakdown, Jessica M. O'Connell Dec 2021

Evaluating Apoptosis, Autophagy, And Hormonal Effects On Oocyte Regulation And Cyst Breakdown, Jessica M. O'Connell

Theses - ALL

Infertility in women is caused by a depletion of eggs below the threshold for functional ovulation. Unlike men where sperm production is maintained throughout their reproductive lifespan, a women's proliferation of eggs ceases prior to birth. Interestingly during development, a fetus has up to 7 million eggs and two-thirds of these eggs die via apoptosis before they are born, further signifying the importance of the quantity control of eggs to maintain fertility. The remaining eggs break apart from each other and become enclosed individually by pre-granulosa cells together forming primordial follicles. Over time, the number of oocytes will continue to …


The Role Of Rab11 Or Rab8-Associated Membranes During Kupffer's Vesicle (Kv) Lumen Formation In Vivo, Eric Ingram Dec 2021

The Role Of Rab11 Or Rab8-Associated Membranes During Kupffer's Vesicle (Kv) Lumen Formation In Vivo, Eric Ingram

Theses - ALL

In early embryonic development, cells undergo a series of shape changes called tissue morphogenesis by which tissues develop into an organ. One mechanism that is potentially vital to tissue morphogenesis is abscission, the cleavage of the cytokinetic bridge. Our lab has proposed that abscission is required for tissue morphogenesis in vivo, specifically in the zebrafish left-right organizer, Kupffer's vesicle (KV). The Hehnly Lab's testable model for KV morphogenesis is that a population of cells, some in cytokinesis, group together in a pre-rosette structure and then self-assemble to form a rosette-structure where cells orient their cytokinetic bridges toward the rosette center. …


Cardiorespiratory Function In Young Adults With A History Of Covid-19 Infection, Danielle Arcidiacono Dec 2021

Cardiorespiratory Function In Young Adults With A History Of Covid-19 Infection, Danielle Arcidiacono

Theses - ALL

Objective. Respiratory complications may persist several months into the recovery period following COVID-19 infection. This study evaluated respiratory function and oxygen saturation variability between young adults with a history of COVID-19 infection and controls. Associations between cardiorespiratory function with potential biobehavioral correlates of COVID-19 infection were also explored.Methods. 57 adults ages 18 to 65 participated in this study (24 COVID+, 33 Control). Spirometry was used to assess pulmonary function volumes of forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), FEV1/FVC and peak expiratory flow (PEF). Exhaled nitric oxide (FeNO) was measured using the NiOX VERO, a handheld …


High-Resolution Cryo-Electron Microscopy Structure Of Photosystem Ii From The Mesophilic Cyanobacterium, Synechocystis Sp. Pcc 6803, Christopher J. Gisriel, Jimin Wang, Jinchan Liu, David A. Flesher, Krystle M. Reiss, Hao-Li Huang, Ke R. Yang, William H. Armstrong, M. R. Gunner, Victor S. Batista, Richard J. Debus, Gary W. Brudvig Dec 2021

High-Resolution Cryo-Electron Microscopy Structure Of Photosystem Ii From The Mesophilic Cyanobacterium, Synechocystis Sp. Pcc 6803, Christopher J. Gisriel, Jimin Wang, Jinchan Liu, David A. Flesher, Krystle M. Reiss, Hao-Li Huang, Ke R. Yang, William H. Armstrong, M. R. Gunner, Victor S. Batista, Richard J. Debus, Gary W. Brudvig

Publications and Research

Photosystem II (PSII) enables global-scale, light-driven water oxidation. Genetic manipulation of PSII from the mesophilic cyanobacterium Synechocystis sp. PCC 6803 has provided insights into the mechanism of water oxidation; however, the lack of a highresolution structure of oxygen-evolving PSII from this organism has limited the interpretation of biophysical data to models based on structures of thermophilic cyanobacterial PSII. Here, we report the cryo-electron microscopy structure of PSII from Synechocystis sp. PCC 6803 at 1.93-Å resolution. A number of differences are observed relative to thermophilic PSII structures, including the following: the extrinsic subunit PsbQ is maintained, the C terminus of the …


Predicting Drug-Induced Liver Injury With Artificial Intelligence, Ting Li Dec 2021

Predicting Drug-Induced Liver Injury With Artificial Intelligence, Ting Li

Theses and Dissertations

Drug-induced liver injury (DILI) is an undesirable side effect to the liver caused by the common use of drugs, which is of great concern to the patients, physicians, the pharmaceutical industry, and government regulators. The current animal testing models do not present reliable results on the human DILI risk prediction during the preclinical phase. Therefore, there is an urgent need to find alternative methods to improve the human DILI risk prediction during the early stage of development. Utilizing the accumulated high-throughput transcriptomics profiles from L1000, we constructed an 8-layer deep neural network for human DILI prediction based on the largest …


A Tale Of Three Resources: The Influence Of Multiple Resources On Plant-Herbivore Interactions, Neha Mohan Babu Dec 2021

A Tale Of Three Resources: The Influence Of Multiple Resources On Plant-Herbivore Interactions, Neha Mohan Babu

Dissertations - ALL

Although studies indicate that plant growth can be co-limited by multiple resources, particularly water, nitrogen (N), and phosphorus (P), the role of co-limiting resources in driving plant-herbivore interactions remains poorly understood. Evidence indicates that the resources that limit plant and herbivore growth may differ which likely influences trophic interactions. In this dissertation, I explored how multiple resource limitation of plants affects herbivore abundance, herbivore impact on plant biomass, and plant traits, using both theoretical and empirical methods. As none of the existing hypotheses account for the effects of multiple resource limitation, I developed a novel theoretical model to predict the …


The Phase Behavior Of Ubqln Proteins And Implications For Protein Quality Control, Yiran Yang Dec 2021

The Phase Behavior Of Ubqln Proteins And Implications For Protein Quality Control, Yiran Yang

Dissertations - ALL

The ubiquitin-proteasome system (UPS) and autophagy are essential pathways for maintaining protein quality control (PQC) in cells. Misfolded proteins and large aggregates are cleared by UPS and autophagy signaled by ubiquitin (Ub) or polyubiquitin (polyUb) chains. Shuttle proteins facilitate cargo transporting by interacting with both ubiquitin and degradation machineries. Previously, our lab discovered that the shuttle protein Ubiquilin-2 (UBQLN2) is recruited to stress granules in cells and undergoes liquid-liquid phase separation (LLPS) in vitro. LLPS is a biophysical process by which proteins separate themselves from the surrounding aqueous solution by forming protein-rich droplets. The overarching goals of this work are …


Direct Single Molecule Imaging Of Enhanced Diffusion For Enzymes And Enzyme-Conjugated Dna Origami, Mengqi Xu Dec 2021

Direct Single Molecule Imaging Of Enhanced Diffusion For Enzymes And Enzyme-Conjugated Dna Origami, Mengqi Xu

Dissertations - ALL

Enzymes have been shown to diffuse faster in the presence of their substrates. Recently, we revealed new insights into this process of enhanced diffusion using single-particle tracking (SPT) with total internal reflection fluorescence (TIRF) microscopy. We found that the mobility of individual enzymes was enhanced three-fold in the presence of the substrate, and the motion remained Brownian. We showed that the relative increase in diffusion is independent of the total enzyme concentrations; and the oligomerization state of enzymes did not change during the catalytic turnover. These experiments ruled out the possibility that the enhanced enzyme diffusion was caused by the …


Developing An Air Pollutant Emissions Database For Global Economic Analysis, Maksym Chepeliev Dec 2021

Developing An Air Pollutant Emissions Database For Global Economic Analysis, Maksym Chepeliev

Department of Agricultural Economics Faculty Publications

According to the Global Burden of Disease study (Cohen et al., 2017), in 2015 ambient air pollutant emissions caused 4.2 million deaths and a loss of 103.1 million disability-adjusted life-years, making it the fifth-ranked global risk factor. In terms of the welfare costs of mortality and illnesses associated with outdoor air pollutant emissions, global estimates for 2015 range between $2.7-3.2 trillion (Coady et al., 2015; OECD, 2016). Still, while greenhouse gas emissions are usually well represented in many global economic databases and models, air pollutant emission accounts in most cases are not included. In particular, this is the case for …


Bactericidal Effects And Stability Of Ll-37 And Cama In The Presence Of Human Lung Epithelial Cells, Regina Geitani, Carole Ayoub Moubareck, Floriane Costes, Léa Marti, Gabrielle Dupuis, Dolla Karam Sarkis, Lhousseine Touqui Dec 2021

Bactericidal Effects And Stability Of Ll-37 And Cama In The Presence Of Human Lung Epithelial Cells, Regina Geitani, Carole Ayoub Moubareck, Floriane Costes, Léa Marti, Gabrielle Dupuis, Dolla Karam Sarkis, Lhousseine Touqui

All Works

Cationic antimicrobial peptides (CAMPs) are important actors in host innate immunity and represent a promising alternative to combat antibiotic resistance. Here, the bactericidal activity of two CAMPs (LL-37, and CAMA) was evaluated against Pseudomonas aeruginosa (PA) in the presence of IB3-1 cells, a cell line derived from patients with cystic fibrosis. The two CAMPs exerted different effects on PA survival depending on the timing of their administration. We observed a greater bactericidal effect when IB3-1 cells were pretreated with sub-minimum bactericidal concentrations (Sub-MBCs) of the CAMPs prior to infection. These findings suggest that CAMPs induce the production of factors by …


Investigating The Behavioral And Social Context Of Sound In The Surface Foraging Strategies Of Humpback Whales (Megaptera Novaeangliae), Sarah Weiss Dec 2021

Investigating The Behavioral And Social Context Of Sound In The Surface Foraging Strategies Of Humpback Whales (Megaptera Novaeangliae), Sarah Weiss

Theses - ALL

Humpback whales are known for the plastic and variable nature of their acoustic communication, social interactions, and foraging behaviors. Distinct foraging strategies are used to capture different prey types at the surface and on the seafloor. Sounds produced during foraging are thought to facilitate intraspecific social communication. Previous studies have identified specific sound types produced by humpbacks associated exclusively with benthic foraging strategies, suggesting functions related to foraging behavior. In this study, we use suction cup acoustic tags (DTAGs) deployed on humpbacks in the western North Atlantic from 2006-2009 to investigate the social sound production associated with surface foraging ecology, …


Fine Scales, Broad Consequences: Drivers And Effects Of Microclimatic Variation In Great Smoky Mountains National Park, Jordan Rebecca Stark Dec 2021

Fine Scales, Broad Consequences: Drivers And Effects Of Microclimatic Variation In Great Smoky Mountains National Park, Jordan Rebecca Stark

Theses - ALL

Climate is highly variable at scales that are not captured by most weather and climate models due to local effects of topography and living systems. This variation in microclimate has been noted for many decades but has been difficult to incorporate into quantitative understanding of ecological systems and processes due to the large amount of data and complex models required to adequately describe fine-scale patterns across complex landscapes. In recent years, models of thermal microclimate variation have been developed using low-cost temperature sensors, but few of these models have been used to predict the effects of microclimatic variation on ecological …


Intralocus Sexual Conflict Over Optimal Nutrient Intake And The Evolution Of Sex Differences In Life Span And Reproduction, Michael Hawkes, Sarah M. Lane, Scott K. Sakaluk, John Hunt, Clarissa M. House, Kim Jensen, James Rapkin Dec 2021

Intralocus Sexual Conflict Over Optimal Nutrient Intake And The Evolution Of Sex Differences In Life Span And Reproduction, Michael Hawkes, Sarah M. Lane, Scott K. Sakaluk, John Hunt, Clarissa M. House, Kim Jensen, James Rapkin

Faculty Publications – Biological Sciences

  1. Despite widespread variation in life span across species, three clear patterns exist: sex differences in life span are ubiquitous, life span is commonly traded against reproduction, and nutrition has a major influence on these traits and how they trade-off. One process that potentially unites these patterns is intralocus sexual conflict over the optimal intake of nutrients for life span and reproduction. If nutrient intake has sex-specific effects on life span and reproduction but nutrient choice is genetically linked across the sexes, intralocus sexual conflict will occur and may prevent one or both sexes from feeding to their nutritional optima.
  2. Here …


Effects Of Nitrogen Fertilization On The Production Of Panicum Maximum Cv. Ipr 86 Under Grazing, S. M. B. Lugão, L. R. De A. Rodrigues, E. B. Malheiros, J. J. Dos S. Abrahão, A. De Morais Dec 2021

Effects Of Nitrogen Fertilization On The Production Of Panicum Maximum Cv. Ipr 86 Under Grazing, S. M. B. Lugão, L. R. De A. Rodrigues, E. B. Malheiros, J. J. Dos S. Abrahão, A. De Morais

IGC Proceedings (1977-2023)

The experiment was conducted at the Experimental Station of Paranavaí/IAPAR-PR-Brazil, from October 1998 to May 1999, to evaluate the effects of N fertilization on Panicum maximum cv. IPR 86 pastures. Four doses of N (0; 150; 300; and 450 kg.ha-1.year-1) were applied to pastures under rotational grazing with grazing cycles (GCs) of 40 days (5 days-grazing and 35 days-rest). It was used a randomized complete block design, with split-plots, and two replications per treatment, being the N-doses studied in the main plots and the GCs in the sub-plots. In all GCs the variables dry matter of …


Effects Of Management Strategies On Seed Production And Seedling Recruitment In Birdsfoot Trefoil-White Clover Mixtures, W. Ayalá, M. Carámbula, D. F. Risso, J. Hodgson, Peter D. Kemp Dec 2021

Effects Of Management Strategies On Seed Production And Seedling Recruitment In Birdsfoot Trefoil-White Clover Mixtures, W. Ayalá, M. Carámbula, D. F. Risso, J. Hodgson, Peter D. Kemp

IGC Proceedings (1977-2023)

The effects of grazing management on seed production, seed bank size and seedling emergence patterns of Trifolium repens cv. Zapicán (WC) and Lotus corniculatus cv. San Gabriel (BFT) oversown swards were evaluated. A complete randomized block design with 4 replicate blocks was used, in which 4 grazing strategies (grazing all year (SI), summer spelling for seed production (S2), winter rest plus summer spelling (S3) and autumn rest plus summer spelling (S4)), were combined with two defoliation severalties (4 and 10 cm height post-grazing residuals). Plots of 110 m2 were grazed monthly by sheep. Seed production, soil seed bank and …


Agricultural Support For The Old Colony Mennonites Of Belize: A Collaborative Effort Between North American Old Order Mennonites And A Cornell Extension Educator, Judson Reid Dec 2021

Agricultural Support For The Old Colony Mennonites Of Belize: A Collaborative Effort Between North American Old Order Mennonites And A Cornell Extension Educator, Judson Reid

Journal of Amish and Plain Anabaptist Studies

The Old Colony Mennonites of Belize practice a conservative form of Anabaptism where technology, dress and lifestyle choices are informed by church standards. Members live in a spatially contiguous Colony, which creates land pressure over time as population increases. The development of new Colonies is necessary for the Mennonites to participate in agricultural livelihoods. The Indian Creek Colony of Belize has experienced agricultural and economic hardships since its inception in the 1989 due to land costs, crop failures and debt structure. Old Order Mennonites of North America developed an outreach effort to assist with on-farm production of vegetable crops to …


Penn State Extension Services And Plain People: An Inside Perspective On A Trust-Based Relationship, Phillip Martin Dec 2021

Penn State Extension Services And Plain People: An Inside Perspective On A Trust-Based Relationship, Phillip Martin

Journal of Amish and Plain Anabaptist Studies

This perspective on Penn State Extension Services and plain people is based on my personal experiences as a plain person, in which I interacted with Extension Services first as a farmer, and then (while working on a doctorate) as a part of the Extension system. Penn State Extension started over a century ago and was deliberate in reaching out to plain (conservative Anabaptist) farmers since the beginning, which led to a history of trust-based cooperation. For all these successes there remain challenges to effective cooperation with certain plain individuals and subgroups. I suggest these challenges are broadly similar to those …