3,823 research outputs found

    Survival of eastern cottontail rabbits (Sylvilagus floridanus) within Missouri river bottomland agroforestry habitats [abstract]

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    Abstract only availableFaculty Mentor: Dr. Joshua J. Millspaugh, Fisheries and Wildlife SciencesEastern cottontail rabbit (Sylvilagus floridanus) herbivory has hindered reforestation efforts at agroforestry sites within the Missouri River floodplain. There is a great need to understand the rabbits' population dynamics and movements within these environments to aid oak reforestation activities. Previous rabbit studies at our study site indicated wide variability in survival of rabbits, which might have influenced the inconsistency we observed in overall herbivory rates. We used radiotelemetry data from January through May 2003 and 2004 and December through March 2004-2005 to investigate survival rates of rabbits within bottomland fields. Monthly survival rates were calculated among the three separate intervals. During 2003, 17 deaths were observed from 24 radio-collared rabbits and in 2004, 44 mortalities of 55 radio-collared rabbits were observed. Finally, in 2005, 20 mortalities were discovered from a total of 41 radio-collared rabbits. Of the 81 observed rabbit mortalities: 33 died from mammalian predation, 10 of avian predation, 1 from hunting and 37 died of unknown causes. These data were related to a variety of factors thought to influence survival. Weather was an important determinant of predation on rabbits; higher predation rates were observed when precipitation occurred previous to discovery of rabbit mortalities. We observed no differences in survival between rabbits' age and gender. Monthly survival rates over the three years show wide variability in amount over time. These data combined with previous works, further support the dominance of mammalian predation on cottontail rabbit populations and of a potential survival/predation latitudinal gradient within the United States.CAFNR On-Campus Research Internship Progra

    Increasing land and forage utilization by Missouri cow/calf operations using silvopasture practices

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    The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file.Title from title screen of research.pdf file (viewed on August 27, 2007)Includes bibliographical references.Thesis (M.S.) University of Missouri-Columbia 2006.Dissertations, Academic -- University of Missouri--Columbia -- Animal sciences.Although rotational grazing has improved pasture management significantly in recent years, the need continues to exist for beef producers to increase land utilization and maintain a high level of forage production during the entire growing season. Two experiments were conducted primarily focusing on methods which allow producers to improve the number of animal grazing days on their operations by implementing silvopastoral systems and increasing forage quality of pastures by applying legumes and warm season grasses. A silvopastoral system was placed under a two-year rotational grazing experiment to determine whether it would support grazing pressure in a shaded environment. Mature pregnant cows were rotated onto five one hectare pastures four times during the two-year period. It was determined that a silvopasture practice can in fact be productive under grazing pressure if managed correctly. Samples of cool season grasses, warm season grasses, and legumes were collected at similar maturities from multiple years and different locations across the state of Missouri. An in depth analysis was done on the forages to determine changes in nutritive value throughout the growing season. It was determined that wet chemistry analysis is a poor indicator of digestibility in some forage types, and in-vitro digestibility is a better indicator of cell wall digestibility

    HIV-Associated CD8 Encephalitis: A UK Case Series and Review of Histopathologically Confirmed Cases

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    HIV-associated CD8-encephalitis (HIV-CD8E) is a severe inflammatory disorder dominated by infiltration of the brain by CD8 T-lymphocytes. It occurs in people with HIV, typically when the virus is apparently well-controlled by antiretroviral treatment (ART). HIV-CD8E presents with symptoms and signs related to marked cerebral inflammation and swelling, and can lead to coma and death unless treated promptly with corticosteroids. Risk events such as intercurrent infection, antiretroviral therapy interruption, immune reconstitution inflammatory syndrome (IRIS) after starting ART, and concomitant associations such as cerebrospinal fluid (CSF) HIV viral escape have been identified, but the pathogenesis of the disorder is not known. We present the largest case series of HIV-CD8E to date (n = 23), representing histopathologically confirmed cases in the UK. We also summarize the global literature representing all previously published cases with histopathological confirmation (n = 30). A new variant of HIV-CD8E is described, occurring on a background of HIV encephalitis (HIVE).Together these series, totalling 53 patients, provide new insights. CSF HIV viral escape was a frequent finding in HIV-CD8E occurring in 68% of those with CSF available and tested; ART interruption and IRIS were important, both occurring in 27%. Black ethnicity appeared to be a key risk factor; all but two UK cases were African, as were the majority of the previously published cases in which ethnicity was stated. We discuss potential pathogenic mechanisms, but there is no unifying explanation over all the HIV-CD8E scenarios.

    The measurement of residual feed intake to determine feed efficiency of pregnant Hereford heifers

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    Abstract only availableThe large potential improvement in profitability is what makes feed efficiency such a studied and concerned topic in the beef industry today. Currently, no herd exists in the United States that has been selected solely for the purpose of measuring and improving feed efficiency. The objective of this study was to rank forty-two pregnant Hereford heifers based on their feed efficiencies, so that they may be mated to bulls of known efficiency. The long term goal of this project is to create both efficient and inefficient herds for future feed efficiency research. These heifers were acquired from various beef producers across the state to ensure genetic variation within the herd. The heifers were fed an alfalfa/grass hay to which they had ad libitum access. Their diet was 86% dry matter and contained 58% neutral detergent fiber, 38% acid detergent fiber, and 14% crude protein on a dry matter basis. The individual intake of each heifer was recorded by the GrowSafe® feed intake system. Expected feed intake was calculated as a regression of actual intake on average daily gain and metabolic mid-weight. Expected feed intake was subtracted from actual feed intake to calculate the residual feed intake value of each individual heifer. Residual feed intake was then used as a measure of feed efficiency. The average body weight at the start of the study was 488 kg. Heifers consumed on average 17.77 ± 5.24 kg/d, and the herd gained at a rate of 0.77 ± 0.32 kg/d. The most efficient heifer consumed 9.78 kg/d less than was expected, while the most inefficient heifer consumed 11.54 kg/d more than was expected. Calculating residual feed intake as a means of determining feed efficiency will enable us to establish both efficient and inefficient herds for further research.F.B. Miller Undergraduate Research Program in Animal Science

    Exposure to NO2, CO, and PM2.5 is linked to regional DNA methylation differences in asthma.

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    Background:DNA methylation of CpG sites on genetic loci has been linked to increased risk of asthma in children exposed to elevated ambient air pollutants (AAPs). Further identification of specific CpG sites and the pollutants that are associated with methylation of these CpG sites in immune cells could impact our understanding of asthma pathophysiology. In this study, we sought to identify some CpG sites in specific genes that could be associated with asthma regulation (Foxp3 and IL10) and to identify the different AAPs for which exposure prior to the blood draw is linked to methylation levels at these sites. We recruited subjects from Fresno, California, an area known for high levels of AAPs. Blood samples and responses to questionnaires were obtained (n = 188), and in a subset of subjects (n = 33), repeat samples were collected 2 years later. Average measures of AAPs were obtained for 1, 15, 30, 90, 180, and 365 days prior to each blood draw to estimate the short-term vs. long-term effects of the AAP exposures. Results:Asthma was significantly associated with higher differentially methylated regions (DMRs) of the Foxp3 promoter region (p = 0.030) and the IL10 intronic region (p = 0.026). Additionally, at the 90-day time period (90 days prior to the blood draw), Foxp3 methylation was positively associated with NO2, CO, and PM2.5 exposures (p = 0.001, p = 0.001, and p = 0.012, respectively). In the subset of subjects retested 2 years later (n = 33), a positive association between AAP exposure and methylation was sustained. There was also a negative correlation between the average Foxp3 methylation of the promoter region and activated Treg levels (p = 0.039) and a positive correlation between the average IL10 methylation of region 3 of intron 4 and IL10 cytokine expression (p = 0.030). Conclusions:Short-term and long-term exposures to high levels of CO, NO2, and PM2.5 were associated with alterations in differentially methylated regions of Foxp3. IL10 methylation showed a similar trend. For any given individual, these changes tend to be sustained over time. In addition, asthma was associated with higher differentially methylated regions of Foxp3 and IL10

    Methane storms as a driver of Titan's dune orientation

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    Titan's equatorial regions are covered by eastward propagating linear dunes. This direction is opposite to mean surface winds simulated by Global Climate Models (GCMs), which are oriented westward at these latitudes, similar to trade winds on Earth. Different hypotheses have been proposed to address this apparent contradiction, involving Saturn's gravitational tides, large scale topography or wind statistics, but none of them can explain a global eastward dune propagation in the equatorial band. Here we analyse the impact of equinoctial tropical methane storms developing in the superrotating atmosphere (i.e. the eastward winds at high altitude) on Titan's dune orientation. Using mesoscale simulations of convective methane clouds with a GCM wind profile featuring superrotation, we show that Titan's storms should produce fast eastward gust fronts above the surface. Such gusts dominate the aeolian transport, allowing dunes to extend eastward. This analysis therefore suggests a coupling between superrotation, tropical methane storms and dune formation on Titan. Furthermore, together with GCM predictions and analogies to some terrestrial dune fields, this work provides a general framework explaining several major features of Titan's dunes: linear shape, eastward propagation and poleward divergence, and implies an equatorial origin of Titan's dune sand.Comment: Published online on Nature Geoscience on 13 April 201

    Towards an embedding of Graph Transformation in Intuitionistic Linear Logic

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    Linear logics have been shown to be able to embed both rewriting-based approaches and process calculi in a single, declarative framework. In this paper we are exploring the embedding of double-pushout graph transformations into quantified linear logic, leading to a Curry-Howard style isomorphism between graphs and transformations on one hand, formulas and proof terms on the other. With linear implication representing rules and reachability of graphs, and the tensor modelling parallel composition of graphs and transformations, we obtain a language able to encode graph transformation systems and their computations as well as reason about their properties

    Resource-Bound Quantification for Graph Transformation

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    Graph transformation has been used to model concurrent systems in software engineering, as well as in biochemistry and life sciences. The application of a transformation rule can be characterised algebraically as construction of a double-pushout (DPO) diagram in the category of graphs. We show how intuitionistic linear logic can be extended with resource-bound quantification, allowing for an implicit handling of the DPO conditions, and how resource logic can be used to reason about graph transformation systems

    UGPS J194310+183851 : an Unusual Optical and X-ray Faint Cataclysmic Variable?

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    ©2022 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society. This is the final published pdf, which was originally published at https://doi.org/10.1093/mnras/stac1718 Funding Information: We acknowledge the use of public data from the Swift data archive. We also acknowledge the use of the WHT: the William Herschel Telescope and its service programme are operated on the island of La Palma by the Isaac Newton Group of Telescopes in the Spanish Observatorio del Roque de los Muchachos of the Instituto de Astrofísica de Canarias. We would like to thank the operations teams at both facilities for the quick and efficient observations. CM acknowledges support from the UK's Science and Technology Facilities Council (ST/S505419/1). NM and WJC are funded by University of Hertfordshire studentships; furthermore CM, PWL, NM, WJC, ZG, and JED recognize the computing infrastructure provided via STFC grant ST/R000905/1 at the University of Hertfordshire. JS acknowledges support from the P ackard F oundation and National Science Foundation grant AST-1714825. Portions of this work were performed while SJS held a NRC Research Associateship award at the Naval Research Laboratory. Work at the Naval Research Laboratory is supported by NASA DPR S-15633-Y. ZG acknowledges the financial support from ANID (CONICYT) through the FONDECYT project No. 3220029. Publisher Copyright: © 2022 The Author(s).The growing number of multi-epoch optical and infrared sky surveys are uncovering unprecedented numbers of new variable stars, of an increasing number of types. The short interval between observations in adjacent near-infrared filters in the UKIDSS Galactic Plane Survey (UGPS) allows for the discovery of variability on the time-scale of minutes. We report on the nature of one such object, through the use of optical spectroscopy, time series photometry, and targeted X-ray observations. We propose that UGPS J194310.32+183851.8 is a magnetic cataclysmic variable star of novel character, probably featuring a longer than average spin period and an orbital period likely to be shorter than the period gap (i.e. Porb < 2 h). We reason that the star is likely a member of the short-period intermediate-polar subclass that exists below this period boundary, but with the additional feature that system's spectral energy distribution is fainter and redder than other members of the group.Peer reviewe
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