39 research outputs found

    Bulletin No. 341 - Rambouillet and Columbia-Rambouillet Lambs on the Range and in the Feed Lot

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    Sheep of predominately Rambouillet breeding have been most popular on southern Utah ranges because of their hardiness and wool-producing ability. In the early years of sheep production in Utah a major portion of the income was derived from the sale of wool. This situation has gradually changed over the past years and now income from the sale of lambs is greater than that from fleeces. Rambouillet rams with improved mutton qualities have been used by some range operators to increase the mutton producing abilities of their ewes. Other operators have used Corriedale, Panama, Columbia, and other white faced crossbred-type rams to achieve more speedily the desired mutton qualities. Because of the interest of Utah sheepmen in the problem of improving their range ewes, the Utah Agricultural Experiment Station, in cooperation with the Branch Agricultural College at Cedar City, established a range sheep unit at Cedar City in 1943 and 1944. This unit has been used to conduct controlled breeding studies aimed at the determination of the type or breed of sheep most desirable for southern Utah range conditions. This bulletin reviews the initial results and gives attention particularly to the qualities of the lambs produced by mating Columbia rams to grade Rambouillet range ewes compared to those produced by mating Rambouillet rams to ewes similar to those bred to the Columbias

    Bulletin No. 307 - Skin Folds in Sheep

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    Sheep vary greatly, even within breeds, in the number and size of folds in the skin. At one time producers were emphasizing the importance of having a large number of skin folds in fine wool sheep such as the Merino and Rambouillet. This was based on the belief that skin folds were associated with high yields of grease wool and fineness of wool fibers. In recent years the trend has been toward a smoother bodied sheep with longer staple and less grease in the fleece. The objects of this bulletin are to present a review of the available information concerning the relative merits of sheep differing in the amount of skin folds, and to present information on the inheritance of this character and the value of early estimates of the amount of skin folds for predicting this character in yearlings. The applications of the findings in sheep breeding are discussed

    Finite size effects and the mixed quark-hadron phase in neutron stars

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    We demonstrate that the form and location (not the size or spacing) of the energetically preferred geometrical structure of the crystalline quark-hadron mixed phase in a neutron star is very sensitive to finite size terms beyond the surface term. We consider two independent approaches of including further finite size terms, namely the multiple reflection expansion of the bag model and an effective surface tension description. Thus care should be taken in any model requiring detailed knowledge of these crystalline structures.Comment: 8 pages, 5 figures, Revtex. (May 13, submitted to PRC

    Astrocytes convert network excitation to tonic inhibition of neurons

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    <p>Abstract</p> <p>Background</p> <p>Glutamate and γ-aminobutyric acid (GABA) transporters play important roles in balancing excitatory and inhibitory signals in the brain. Increasing evidence suggest that they may act concertedly to regulate extracellular levels of the neurotransmitters.</p> <p>Results</p> <p>Here we present evidence that glutamate uptake-induced release of GABA from astrocytes has a direct impact on the excitability of pyramidal neurons in the hippocampus. We demonstrate that GABA, synthesized from the polyamine putrescine, is released from astrocytes by the reverse action of glial GABA transporter (GAT) subtypes GAT-2 or GAT-3. GABA release can be prevented by blocking glutamate uptake with the non-transportable inhibitor DHK, confirming that it is the glutamate transporter activity that triggers the reversal of GABA transporters, conceivably by elevating the intracellular Na<sup>+ </sup>concentration in astrocytes. The released GABA significantly contributes to the tonic inhibition of neurons in a network activity-dependent manner. Blockade of the Glu/GABA exchange mechanism increases the duration of seizure-like events in the low-[Mg<sup>2+</sup>] <it>in vitro </it>model of epilepsy. Under <it>in vivo </it>conditions the increased GABA release modulates the power of gamma range oscillation in the CA1 region, suggesting that the Glu/GABA exchange mechanism is also functioning in the intact hippocampus under physiological conditions.</p> <p>Conclusions</p> <p>The results suggest the existence of a novel molecular mechanism by which astrocytes transform glutamat<it>ergic </it>excitation into GABA<it>ergic </it>inhibition providing an adjustable, <it>in situ </it>negative feedback on the excitability of neurons.</p

    Signal transduction-related responses to phytohormones and environmental challenges in sugarcane

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    BACKGROUND: Sugarcane is an increasingly economically and environmentally important C4 grass, used for the production of sugar and bioethanol, a low-carbon emission fuel. Sugarcane originated from crosses of Saccharum species and is noted for its unique capacity to accumulate high amounts of sucrose in its stems. Environmental stresses limit enormously sugarcane productivity worldwide. To investigate transcriptome changes in response to environmental inputs that alter yield we used cDNA microarrays to profile expression of 1,545 genes in plants submitted to drought, phosphate starvation, herbivory and N(2)-fixing endophytic bacteria. We also investigated the response to phytohormones (abscisic acid and methyl jasmonate). The arrayed elements correspond mostly to genes involved in signal transduction, hormone biosynthesis, transcription factors, novel genes and genes corresponding to unknown proteins. RESULTS: Adopting an outliers searching method 179 genes with strikingly different expression levels were identified as differentially expressed in at least one of the treatments analysed. Self Organizing Maps were used to cluster the expression profiles of 695 genes that showed a highly correlated expression pattern among replicates. The expression data for 22 genes was evaluated for 36 experimental data points by quantitative RT-PCR indicating a validation rate of 80.5% using three biological experimental replicates. The SUCAST Database was created that provides public access to the data described in this work, linked to tissue expression profiling and the SUCAST gene category and sequence analysis. The SUCAST database also includes a categorization of the sugarcane kinome based on a phylogenetic grouping that included 182 undefined kinases. CONCLUSION: An extensive study on the sugarcane transcriptome was performed. Sugarcane genes responsive to phytohormones and to challenges sugarcane commonly deals with in the field were identified. Additionally, the protein kinases were annotated based on a phylogenetic approach. The experimental design and statistical analysis applied proved robust to unravel genes associated with a diverse array of conditions attributing novel functions to previously unknown or undefined genes. The data consolidated in the SUCAST database resource can guide further studies and be useful for the development of improved sugarcane varieties

    Worldwide trends in underweight and obesity from 1990 to 2022: a pooled analysis of 3663 population-representative studies with 222 million children, adolescents, and adults

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    Background Underweight and obesity are associated with adverse health outcomes throughout the life course. We estimated the individual and combined prevalence of underweight or thinness and obesity, and their changes, from 1990 to 2022 for adults and school-aged children and adolescents in 200 countries and territories. Methods We used data from 3663 population-based studies with 222 million participants that measured height and weight in representative samples of the general population. We used a Bayesian hierarchical model to estimate trends in the prevalence of different BMI categories, separately for adults (age ≥20 years) and school-aged children and adolescents (age 5–19 years), from 1990 to 2022 for 200 countries and territories. For adults, we report the individual and combined prevalence of underweight (BMI &lt;18·5 kg/m2) and obesity (BMI ≥30 kg/m2). For school&#x2;aged children and adolescents, we report thinness (BMI &lt;2 SD below the median of the WHO growth reference) and obesity (BMI &gt;2 SD above the median). Findings From 1990 to 2022, the combined prevalence of underweight and obesity in adults decreased in 11 countries (6%) for women and 17 (9%) for men with a posterior probability of at least 0·80 that the observed changes were true decreases. The combined prevalence increased in 162 countries (81%) for women and 140 countries (70%) for men with a posterior probability of at least 0·80. In 2022, the combined prevalence of underweight and obesity was highest in island nations in the Caribbean and Polynesia and Micronesia, and countries in the Middle East and north Africa. Obesity prevalence was higher than underweight with posterior probability of at least 0·80 in 177 countries (89%) for women and 145 (73%) for men in 2022, whereas the converse was true in 16 countries (8%) for women, and 39 (20%) for men. From 1990 to 2022, the combined prevalence of thinness and obesity decreased among girls in five countries (3%) and among boys in 15 countries (8%) with a posterior probability of at least 0·80, and increased among girls in 140 countries (70%) and boys in 137 countries (69%) with a posterior probability of at least 0·80. The countries with highest combined prevalence of thinness and obesity in school-aged children and adolescents in 2022 were in Polynesia and Micronesia and the Caribbean for both sexes, and Chile and Qatar for boys. Combined prevalence was also high in some countries in south Asia, such as India and Pakistan, where thinness remained prevalent despite having declined. In 2022, obesity in school-aged children and adolescents was more prevalent than thinness with a posterior probability of at least 0·80 among girls in 133 countries (67%) and boys in 125 countries (63%), whereas the converse was true in 35 countries (18%) and 42 countries (21%), respectively. In almost all countries for both adults and school-aged children and adolescents, the increases in double burden were driven by increases in obesity, and decreases in double burden by declining underweight or thinness. Interpretation The combined burden of underweight and obesity has increased in most countries, driven by an increase in obesity, while underweight and thinness remain prevalent in south Asia and parts of Africa. A healthy nutrition transition that enhances access to nutritious foods is needed to address the remaining burden of underweight while curbing and reversing the increase in obesit

    Bulletin No. 298 - Wool Scouring Tests in Utah

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    Wool, as it is shorn from the sheep, is known as grease wool. The first step in the manufacturing of wool is scouring, or removal of all grease and foreign matter. Within any given grade, as determined by length of staple and fineness of fiber, the yield of clean wool is the primary factor in determining the value of the original grease wool. The price of scoured or clean wool is multiplied by the percentage yield of clean wool to determine the value of the grease wool

    Bulletin No. 292 - Effects of Feeding Ewe Lambs During Their First Winter

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    It has been observed that many ewes in Utah are somewhat under size when eighteen months old, the usual age for first breeding. It is a common experience for these ewes to produce much smaller lamb and wool crops than the older ewes

    Bulletin No. 295 - Comparison of Two Methods of Determining Wool Density

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    Density of the fleece is one of the primary factors determining the wool-producing capacity of the sheep. Sheepmen have attempted to evaluate density by handling the fleece. This method is not sufficiently refined for use in experimental work, and may be subject to errors and misinterpretations. For example, if two fleeces are alike in density and diameter of fibers, yet differ in length, the longer fleece will feel less dense. If, on this basis, the sheep with the fleece that appeared most dense were selected for breeding, selection would be away from the longer fleece. Any method that can be used to measure accurately the density of the fleece will be very useful in inheritance and wool production studies
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