3,180 research outputs found

    Submitting Specimens to the Veterinary Diagnostic Laboratory

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    The advances in diagnostic veterinary medicine are developing at an ever increasing rate. As new techniques are put into use, there are difficulties in informing the general practitioner of these procedures. This paper was compiled to aid you, the practitioner, in submitting specimens to the ISU Veterinary Diagnostic Laboratory. This section is centered in this issue so that removal is possible. In this listing, each disease will have comments on the specimen(s) to submit, the preservation of that specimen, and the procedures that will be performed by the laboratory

    Experimental Heat Transfer Supporting Simulated Water Well Performance on Mars

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    Favorable indications of massive quantities of water on Mars have initiated studies of potential changes to human Mars missions. Using a technique known as a Rodriguez Well to melt the ice, store the resulting water in a subsurface ice cavity until needed, and then pump water to the surface for use is one potential means to effect these changes. A computer simulation of the Rodriguez Well in a terrestrial environment is one of the engineering tools being used to characterize the performance of this type of well on Mars. An experiment at the NASA Johnson Space Center is gathering data for convective heat transfer and evaporation rates at Mars surface conditions so that this computer simulation can be properly modified to predict performance on Mars. While quantitative results await processing, tests have indicated that a pool of water can be maintained at 1C to 2 C while at Mars surface temperatures and pressures

    Impact of future climate change on water temperature and thermal habitat for keystone fishes in the Lower Saint John River, Canada

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    Water temperature is a key determinant of biological processes in rivers. Temperature in northern latitude rivers is expected to increase under climate change, with potentially adverse consequences for cold water-adapted species. In Canada, little is currently known about the timescales or magnitude of river temperature change, particularly in large (≥104 km2) watersheds. However, because Canadian watersheds are home to a large number of temperature-sensitive organisms, there is a pressing need to understand the potential impacts of climate change on thermal habitats. This paper presents the results of a study to simulate the effects of climate change on the thermal regime of the lower Saint John River (SJR), a large, heavily impounded, socio-economically important watershed in eastern Canada. The CEQUEAU hydrological-water temperature model was calibrated against river temperature observations and driven using meteorological projections from a series of regional climate models. Changes in water temperature were assessed for three future periods (2030–2034, 2070–2074 and 2095–2099). Results show that mean water temperature in the SJR will increase by approximately ~1 °C by 2070–2074 and a further ~1 °C by 2095–2099, with similar findings for the maximum, minimum and standard deviation. We calculated a range of temperature metrics pertaining to the Atlantic Salmon and Striped Bass, key species within the SJR. Results show that while the SJR will become increasingly thermally-limiting for Atlantic Salmon, the Striped Bass growth season may actually lengthen under climate change. These results provide an insight into how climate change may affect thermal habitats for fish in eastern Canadian rivers

    Systematic genetic array analysis links the Saccharomyces cerevisiae SAGA/SLIK and NuA4 component Tra1 to multiple cellular processes

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    <p>Abstract</p> <p>Background</p> <p>Tra1 is an essential 437-kDa component of the <it>Saccharomyces cerevisiae </it>SAGA/SLIK and NuA4 histone acetyltransferase complexes. It is a member of a group of key signaling molecules that share a carboxyl-terminal domain related to phosphatidylinositol-3-kinase but unlike many family members, it lacks kinase activity. To identify genetic interactions for <it>TRA1 </it>and provide insight into its function we have performed a systematic genetic array analysis (SGA) on <it>tra1</it><sub><it>SRR</it>3413</sub>, an allele that is defective in transcriptional regulation.</p> <p>Results</p> <p>The SGA analysis revealed 114 synthetic slow growth/lethal (SSL) interactions for <it>tra1</it><sub><it>SRR</it>3413</sub>. The interacting genes are involved in a range of cellular processes including gene expression, mitochondrial function, and membrane sorting/protein trafficking. In addition many of the genes have roles in the cellular response to stress. A hierarchal cluster analysis revealed that the pattern of SSL interactions for <it>tra1</it><sub><it>SRR</it>3413 </sub>most closely resembles deletions of a group of regulatory GTPases required for membrane sorting/protein trafficking. Consistent with a role for Tra1 in cellular stress, the <it>tra1</it><sub><it>SRR</it>3413 </sub>strain was sensitive to rapamycin. In addition, calcofluor white sensitivity of the strain was enhanced by the protein kinase inhibitor staurosporine, a phenotype shared with the Ada components of the SAGA/SLIK complex. Through analysis of a GFP-Tra1 fusion we show that Tra1 is principally localized to the nucleus.</p> <p>Conclusion</p> <p>We have demonstrated a genetic association of Tra1 with nuclear, mitochondrial and membrane processes. The identity of the SSL genes also connects Tra1 with cellular stress, a result confirmed by the sensitivity of the <it>tra1</it><sub><it>SRR</it>3413 </sub>strain to a variety of stress conditions. Based upon the nuclear localization of GFP-Tra1 and the finding that deletion of the Ada components of the SAGA complex result in similar phenotypes as <it>tra1</it><sub><it>SRR</it>3413</sub>, we suggest that the effects of <it>tra1</it><sub><it>SRR</it>3413 </sub>are mediated, at least in part, through its role in the SAGA complex.</p

    Simulated Water Well Performance on Mars

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    This paper describes improvements in our understanding of the nature and location of massive ice sheets on the surface of Mars as well as refinements made to a technical approach for extracting significant quantities of water from these ice sheets using a technique known as a Rodriguez Well. Recently published discoveries on Mars have reinforced the evidence for the existence and structure of these massive buried ice sheets. Using this improved understanding of the feedstock material, this paper describes estimates made regarding basic characteristics - mass, power, configuration, etc. - of a system that can access and extract water from these ice sheets. This paper then summarizes the basic operation of a Rodriguez Well and describes a computer simulation used to estimate the performance characteristics of this type of well. This simulation was built and used to predict the performance of similar wells operated in the Earth's Arctic and Antarctic regions. However, physical parameters (e.g., specific heat and gas constant for air, heat transfer between water and air and between ice and air, etc.) used in the simulation represent a terrestrial environment and must be adjusted for a Martian environment. A pair of experiments designed to determine the appropriate values for these parameters under Martian conditions is described. Until results from these experiments are available, published results from other sources are used in the simulation to gain an understanding of the effect that could be seen. These provisional results are discussed

    Concentration Dependence of Elastic and Viscoelastic Properties of Aqueous Solutions of Ficoll and Bovine Serum Albumin by Brillouin Light Scattering Spectroscopy

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    The cellular environment is crowded with macromolecules of different shapes and sizes. The effect of this macromolecular crowding has been studied in a variety of synthetic crowding environments: two popular examples are the compact colloid-like Ficoll macromolecule, and the globular protein bovine serum albumin (BSA). Recent studies have indicated a significant component of bound or surface-associated water in these crowders reduces the available free volume. In this work, Brillouin light scattering experiments were performed on aqueous solutions of Ficoll 70 and Ficoll 400 with concentrations ranging from 1 wt% to 35 wt% and BSA with concentrations of 1 wt% to 27 wt%. From the dependence of spectral peak parameters on polymer concentration, we determined fundamental solution properties: hypersound velocity, adiabatic bulk modulus and compressibility, apparent viscosity, and hypersound attenuation. Existing theory that ignores intermolecular interactions can only capture the observed linear trends in the frequency shift up to a threshold concentration, beyond which a quadratic term accounting for intermolecular interactions is necessary. This likely indicates a transition from the dilute to semi-dilute regime. In the Ficoll solutions (but not BSA) we see evidence for a central mode, with a characteristic relaxation time of 20 ps, that we attribute to exchange of the bound water.Comment: 10 pages, 4 figures, 4 table

    Mumps and rubella surveillance in Victoria, 1993 to 2000

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    Despite improving childhood coverage of the measles-mumps-rubella vaccine (MMR) in Victoria during the 1990s, mumps and rubella notifications in age groups eligible for vaccination persisted. This study reviewed the mumps and rubella surveillance data from 1993 to 2000 with a specific focus on method of diagnosis. There were 474 notifications of mumps over the seven-year period (annual median 61, range 40 to 77) and 3,544 notifications of rubella (annual median 297, range 66 to 1,165). The highest notifications rates for mumps were consistently among the 1-4 and 5-9 year age groups, whereas there was a marked change in the age distribution of rubella notifications during this interval. A large rubella outbreak occurred in 1995 with 1,165 notifications; the highest notification rates were males aged 15-24 years, infants under one year of age (males and females), and those aged 5-14 years (males and females), respectively. The susceptibility of 5-24 year olds reflects historical changes to the Australian Standard Vaccination Schedule. Rubella notifications returned to baseline levels in 1998 with the highest notification rates in infants aged under one year, and children aged 1-4 years. For both mumps and rubella, the majority of notifications for all age groups were clinically diagnosed, and were most common in children. Commun Dis Intell 2003;27:94-99

    Identification of a Core Amino Acid Motif within the α Subunit of GABAARs that Promotes Inhibitory Synaptogenesis and Resilience to Seizures

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    The fidelity of inhibitory neurotransmission is dependent on the accumulation of γ-aminobutyric acid type A receptors (GABAARs) at the appropriate synaptic sites. Synaptic GABAARs are constructed from α(1-3), β(1-3), and γ2 subunits, and neurons can target these subtypes to specific synapses. Here, we identify a 15-amino acid inhibitory synapse targeting motif (ISTM) within the α2 subunit that promotes the association between GABAARs and the inhibitory scaffold proteins collybistin and gephyrin. Using mice in which the ISTM has been introduced into the α1 subunit (Gabra1-2 mice), we show that the ISTM is critical for axo-axonic synapse formation, the efficacy of GABAergic neurotransmission, and seizure sensitivity. The Gabra1-2 mutation rescues seizure-induced lethality in Gabra2-1 mice, which lack axo-axonic synapses due to the deletion of the ISTM from the α2 subunit. Taken together, our data demonstrate that the ISTM plays a critical role in promoting inhibitory synapse formation, both in the axonic and somatodendritic compartments

    Characterization of VAR2CSA-deficient Plasmodium falciparum-infected erythrocytes selected for adhesion to the BeWo placental cell line

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    Background. Malaria in pregnancy is characterized by accumulation of infected erythrocytes (IE) in the placenta. The key ligand identified as mediating this process is a Plasmodium falciparum erythrocyte membrane protein 1 family member, termed VAR2CSA. VAR2CSA appears to be the main ligand responsible for adhesion to chondroitin sulphate A (CSA). Whether other PfEMP1 molecules can also mediate placental adhesion, independent of CSA binding, is unclear. Methods. The parasite line CS2 carrying a disrupted var2csa gene (CS2KO) was selected for adhesion to the BeWo choriocarcinoma cell line, which has been proposed as a model for placental malaria. The selected and control IE were tested for adhesion to placental sections and flow cytometry was used to measure recognition of IE by three serum sets from malaria-exposed men and women. Results. Wild-type CS2 adhere to BeWo and placental tissue via CSA. CS2KO IE were successfully selected for adhesion to BeWo, and adhered by a CSA-independent mechanism. They bound to immobilized ICAM-1 and CD36. BeWo-selected CS2KO bound at moderate levels to placental sections, but most binding was to placental villi rather than to the syncytiotrophoblast to which IE adherence occurs in vivo. This binding was inhibited by a blocking antibody to CD36 but not to ICAM-1. As expected, sera from malaria-exposed adults recognized CS2 IE in a gender and parity dependent manner. In one serum set, there was a similar but less pronounced pattern of antibody binding to selected CS2KO IE, but this was not seen in two others. One var gene, It4var19, was particularly abundant in the selected line and was detected as full length transcripts in BeWo-selected IE, but not unselected CS2KO. Conclusion. This study suggests that IE with characteristics similar to the CS2KO have a limited role in the pathogenesis of placental malaria. VAR2CSA appear to be the major ligand for placental adhesion, and could be the basis for a vaccine against pregnancy malaria

    The Structure of the Non-SUSY Baryonic Branch of Klebanov-Strassler

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    We study the two-dimensional space of supergravity solutions corresponding to non-supersymmetric deformations of the baryonic branch of Klebanov-Strassler. By combining analytical methods with a numerical survey of the parameter space, we find that this solution space includes as limits the softly-broken N=1 solutions of Gubser et al. and those of Dymarsky and Kuperstein. We also identify a one-dimensional family of solutions corresponding to a natural non-supersymmetric generalisation of Klebanov-Strassler, and one corresponding to the limit in which supersymmetry is completely absent, even in the far UV. For almost all of the parameter space we find indications that much of the structure of the supersymmetric baryonic branch survives.Comment: 29 pages plus appendices, 11 figure
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