4,047 research outputs found

    Variation in actual relationship among descendants of inbred individuals

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    In previous analyses, the variation in actual, or realized, relationship has been derived as a function of map length of chromosomes and type of relationship, the variation being greater the shorter the total chromosome length and the coefficient of variation being greater the more distant the relationship. Here, the results are extended to allow for the relatives' ancestor being inbred. Inbreeding of a parent reduces variation in actual relationship among its offspring, by an amount that depends on the inbreeding level and the type of mating that led to that level. For descendants of full-sibs, the variation is reduced in later generations, but for descendants of half-sibs, it is increased

    Highly syntenic and yet divergent: a tale of two Theilerias

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    The published genomic sequences of the two major host-transforming Theileria species of cattle represent a rich resource of information that has allowed novel bioinformatic and experimental studies into these important apicomplexan parasites. Since their publication in 2005, the genomes of T. annulata and T. parva have been utilised for a diverse range of applications, ranging from candidate antigen discovery to the identification of genetic markers for population analysis. This has led to advancements in the quest for a sub-unit vaccine, while providing a greater understanding of variation among parasite populations in the field. The unique ability of these Theileria species to induce host cell transformation is the subject of considerable scientific interest and the availability of full genomic sequences has provided new insights into this area of research. This article reviews the data underlying published comparative analyses, focussing on the general features of gene expression, the major Tpr/Tar multi-copy gene family and a re-examination of the predicted macroschizont secretome. Codon usage between the Theileria species is reviewed in detail, as this underpins ongoing comparative studies investigating selection at the intra- and inter-species level. The TashAT/TpshAT family of genes, conserved between T. annulata and T. parva, encodes products targeted to the host nucleus and has been implicated in contributing to the transformed bovine phenotype. Species-specific expansion and diversification at this critical locus is discussed with reference to the availability, in the near future, of genomic datasets which are based on non-transforming Theileria species

    Mineral Resources of the Phipps-Death Hollow Instant Study Area, Garfield County, Utah

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    During 1979 and 1980 the U.S. Geological Survey and the U.S. Bureau of Mines conducted field studies to evaluate the mineral-resource potential of the Phipps-Death Hollow Instant Study Area, Garfield County, Utah. Field studies included geological mapping (Weir and Beard, 1981), geochemical sampling, and a search for mines, prospects and mineralized areas

    Defect formation in superconducting rings: external fields and finite-size effects

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    Consistent with the predictions of Kibble and Zurek, scaling behaviour has been seen in the production of fluxoids during temperature quenches of superconducting rings. However, deviations from the canonical behaviour arise because of finite-size effects and stray external fields. Technical developments, including laser heating and the use of long Josephson tunnel junctions, have improved the quality of data that can be obtained. With new experiments in mind we perform large-scale 3D simulations of quenches of small, thin rings of various geometries with fully dynamical electromagnetic fields, at nonzero externally applied magnetic flux. We find that the outcomes are, in practice, indistinguishable from those of much simpler Gaussian analytical approximations in which the rings are treated as one-dimensional systems and the magnetic field fluctuation-free.Comment: 10 pages, 3 figures, presentation at QFS2012, to appear in JLT

    Wheat potential yield trials - 79KA17 D. Hall, Beaufort River - 79WH32 Wongan Hills Research Station

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    COMMENTS 1. No insect problems experienced and broadleaf weeds effectively controlled by spraying. Septoria· leaf spot incidence insufficient to affect yields. 2. Little effect of time of planting on either total dry matter or grain yield. Crop received about 70% of the average May-October rainfall with a very dry September-October. Perhaps the distribution of rainfall allowed a similar pattern of water use, and total water use by each planting time. 3. There is probably a significant effect of Nitrogen regime on grain yield. Osmocote (N3) consistently yielded more than either single (N1) or repeated (N2) dressings of Agran 34:0. The continuous source was most effective in increasing grain numbers/m2 but only reduced grain weights slightly ~ compared to N1. Repeated (N2) applications although increasing grain numbers above N1, led to much reduced grain weights. The single application (N1) although producing the lowest grain numbers had the highest grain weights. 4. Soil moisture levels were recorded throughout the trial and will be used with a water balance to attempt to explain the results

    Variation in actual relationship as a consequence of Mendelian sampling and linkage

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    Although the expected relationship or proportion of genome shared by pairs of relatives can be obtained from their pedigrees, the actual quantities deviate as a consequence of Mendelian sampling and depend on the number of chromosomes and map length. Formulae have been published previously for the variance of actual relationship for a number of specific types of relatives but no general formula for non-inbred individuals is available. We provide here a unified framework that enables the variances for distant relatives to be easily computed, showing, for example, how the variance of sharing for great grandparent–great grandchild, great uncle–great nephew, half uncle–nephew and first cousins differ, even though they have the same expected relationship. Results are extended in order to include differences in map length between sexes, no recombination in males and sex linkage. We derive the magnitude of skew in the proportion shared, showing the skew becomes increasingly large the more distant the relationship. The results obtained for variation in actual relationship apply directly to the variation in actual inbreeding as both are functions of genomic coancestry, and we show how to partition the variation in actual inbreeding between and within families. Although the variance of actual relationship falls as individuals become more distant, its coefficient of variation rises, and so, exacerbated by the skewness, it becomes increasingly difficult to distinguish different pedigree relationships from the actual fraction of the genome shared

    Infrared nonredundant mask imaging at Palomar

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    A program of high resolution infrared imaging at Palomar Observatory, is presented. The use of nonredundant masks both as an imaging technique and as a method of analyzing various aspects of the imaging system are investigated. In particular, the technique is applied to a bright star and binary system using a three-hole mask. The method is useful for understanding certain systematic biases in data, as well as in producing high quality images despite sparse UV coverage. The use of multi-r(o) apertures along with a large bandwidth does not significantly hamper image reconstruction, but provides significant extra coverage in the UV plane

    The Virtual International Stroke Trials Archive

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    BACKGROUND AND PURPOSE: Stroke has global importance and it causes an increasing amount of human suffering and economic burden, but its management is far from optimal. The unsuccessful outcome of several research programs highlights the need for reliable data on which to plan future clinical trials. The Virtual International Stroke Trials Archive aims to aid the planning of clinical trials by collating and providing access to a rich resource of patient data to perform exploratory analyses. METHODS: Data were contributed by the principal investigators of numerous trials from the past 16 years. These data have been centrally collated and are available for anonymized analysis and hypothesis testing. RESULTS: Currently, the Virtual International Stroke Trials Archive contains 21 trials. There are data on \u3e15,000 patients with both ischemic and hemorrhagic stroke. Ages range between 18 and 103 years, with a mean age of 69+/-12 years. Outcome measures include the Barthel Index, Scandinavian Stroke Scale, National Institutes of Health Stroke Scale, Orgogozo Scale, and modified Rankin Scale. Medical history and onset-to-treatment time are readily available, and computed tomography lesion data are available for selected trials. CONCLUSIONS: This resource has the potential to influence clinical trial design and implementation through data analyses that inform planning

    Using keystroke logging to understand writers’ processes on a reading-into-writing test

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    Background Integrated reading-into-writing tasks are increasingly used in large-scale language proficiency tests. Such tasks are said to possess higher authenticity as they reflect real-life writing conditions better than independent, writing-only tasks. However, to effectively define the reading-into-writing construct, more empirical evidence regarding how writers compose from sources both in real-life and under test conditions is urgently needed. Most previous process studies used think aloud or questionnaire to collect evidence. These methods rely on participants’ perceptions of their processes, as well as their ability to report them. Findings This paper reports on a small-scale experimental study to explore writers’ processes on a reading-into-writing test by employing keystroke logging. Two L2 postgraduates completed an argumentative essay on computer. Their text production processes were captured by a keystroke logging programme. Students were also interviewed to provide additional information. Keystroke logging like most computing tools provides a range of measures. The study examined the students’ reading-into-writing processes by analysing a selection of the keystroke logging measures in conjunction with students’ final texts and interview protocols. Conclusions The results suggest that the nature of the writers’ reading-into-writing processes might have a major influence on the writer’s final performance. Recommendations for future process studies are provided
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