6,700 research outputs found

    Calcitonin receptor-like receptor is expressed on gastrointestinal immune cells

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    Background/Aims: Pharmacological and morphological studies suggest that the gut mucosal immune system and local neuropeptide-containing neurones interact. We aimed to determine whether gut immune cells are targets for calcitonin gene-related peptide (CGRP), which has potent immune regulatory properties. Methods: Using density gradient centrifugation, rat lamina propria mononuclear cells (LP-MNCs) and intra-epithelial lymphocytes (IELs) were isolated. RT-PCR was employed for the detection of mRNA of rat calcitonin receptor-like receptor (CRLR), which is considered to represent the pharmacologically defined CGRP receptor-1 subtype, as well as mRNA of the receptor activity-modifying proteins, which are essential for CRLR function and determine ligand specificity. A radioreceptor assay was employed for the detection of specific CGRP binding sites. Results: RT-PCR and DNA sequencing showed that LP-MNCs and IELs express CRLR. Incubation of isolated LP-MNCs with radiolabelled alphaCGRP revealed the existence of specific binding sites for CGRP. Conclusion: These novel data indicate that mucosal immune cells of the rat gut are a target for CGRP and provide significant evidence that CGRP functions as an immune regulator in the gut mucosa. Copyright (C) 2002 S. Karger AG, Basel

    REPRESENTATION OF A CLASS OF STOCHASTIC Processes

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    Turbulent mixing layers in supersonic protostellar outflows, with application to DG Tauri

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    Turbulent entrainment processes may play an important role in the outflows from young stellar objects at all stages of their evolution. In particular, lateral entrainment of ambient material by high-velocity, well-collimated protostellar jets may be the cause of the multiple emission-line velocity components observed in the microjet-scale outflows driven by classical T Tauri stars. Intermediate-velocity outflow components may be emitted by a turbulent, shock- excited mixing layer along the boundaries of the jet. We present a formalism for describing such a mixing layer based on Reynolds decomposition of quantities measuring fundamental properties of the gas. In this model, the molecular wind from large disc radii provides a continual supply of material for entrainment. We calculate the total stress profile in the mixing layer, which allows us to estimate the dissipation of turbulent energy, and hence the luminosity of the layer. We utilize MAPPINGS IV shock models to determine the fraction of total emission that occurs in [Fe II] 1.644 {\mu}m line emission in order to facilitate comparison to previous observations of the young stellar object DG Tauri. Our model accurately estimates the luminosity and changes in mass outflow rate of the intermediate-velocity component of the DG Tau approaching outflow. Therefore, we propose that this component represents a turbulent mixing layer surrounding the well-collimated jet in this object. Finally, we compare and contrast our model to previous work in the field.Comment: 18 pages, 13 figures, accepted for publication in MNRA

    The radial evolution of solar wind speeds

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    The WSA-ENLIL model predicts significant evolution of the solar wind speed. Along a flux tube the solar wind speed at 1.0 AU and beyond is found to be significantly altered from the solar wind speed in the outer corona at 0.1 AU, with most of the change occurring within a few tenths of an AU from the Sun. The evolution of the solar wind speed is most pronounced during solar minimum for solar wind with observed speeds at 1.0 AU between 400 and 500 km/s, while the fastest and slowest solar wind experiences little acceleration or deceleration. Solar wind ionic charge state observations made near 1.0 AU during solar minimum are found to be consistent with a large fraction of the intermediate-speed solar wind having been accelerated or decelerated from slower or faster speeds. This paper sets the groundwork for understanding the evolution of wind speed with distance, which is critical for interpreting the solar wind composition observations near Earth and throughout the inner heliosphere. We show from composition observations that the intermediate-speed solar wind (400-500 km/s) represents a mix of what was originally fast and slow solar wind, which implies a more bimodal solar wind in the corona than observed at 1.0 AU

    Self-esteem outcomes over a summer camp for obese youth.

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    Variation in the existing literature on the psychosocial benefits of weight loss in obese youth results, in part, from methodological limitations and modest weight loss. Accordingly, this research assessed perceived self-competence and low self-esteem during an intensive weight loss programme in a large sample of obese youth and related these to starting weight, gender and weight loss.Over 4 years, 303 obese male and female adolescents (body mass index [BMI] 34.3 kg m(-2) , BMI standard deviation score 2.99; 14.7 years) attended a residential weight loss camp for a mean duration of 31 d. Outcome variables included dimensional self-esteem (Harter) and weight change over the camp.At the start of camp, obese youth scored highest on social acceptance and lowest on physical appearance and athletic competence. Global self-worth and most domains of self-competence improved significantly over the intervention. The proportion with low global self-worth reduced from 35% to 16%, but there was little change in the proportion reporting high self-competence (23%). Mean weight loss was -5.5 kg (BMI standard deviation scores -0.25) with boys and those heaviest at the start losing most. Weight loss was significantly correlated with improved physical appearance (r = 0.13) and athletic competence (r = 0.19), but not global self-worth.This intensive weight loss intervention yielded significant psychological benefit, especially in self-competence and among individuals achieving most weight loss. The weak association with weight loss suggests the influence of other contributing environmental or social features that should be the focus of further research

    Maximum Matching in Turnstile Streams

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    We consider the unweighted bipartite maximum matching problem in the one-pass turnstile streaming model where the input stream consists of edge insertions and deletions. In the insertion-only model, a one-pass 22-approximation streaming algorithm can be easily obtained with space O(nlogn)O(n \log n), where nn denotes the number of vertices of the input graph. We show that no such result is possible if edge deletions are allowed, even if space O(n3/2δ)O(n^{3/2-\delta}) is granted, for every δ>0\delta > 0. Specifically, for every 0ϵ10 \le \epsilon \le 1, we show that in the one-pass turnstile streaming model, in order to compute a O(nϵ)O(n^{\epsilon})-approximation, space Ω(n3/24ϵ)\Omega(n^{3/2 - 4\epsilon}) is required for constant error randomized algorithms, and, up to logarithmic factors, space O(n22ϵ)O( n^{2-2\epsilon} ) is sufficient. Our lower bound result is proved in the simultaneous message model of communication and may be of independent interest

    Linear Programming in the Semi-streaming Model with Application to the Maximum Matching Problem

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    In this paper, we study linear programming based approaches to the maximum matching problem in the semi-streaming model. The semi-streaming model has gained attention as a model for processing massive graphs as the importance of such graphs has increased. This is a model where edges are streamed-in in an adversarial order and we are allowed a space proportional to the number of vertices in a graph. In recent years, there has been several new results in this semi-streaming model. However broad techniques such as linear programming have not been adapted to this model. We present several techniques to adapt and optimize linear programming based approaches in the semi-streaming model with an application to the maximum matching problem. As a consequence, we improve (almost) all previous results on this problem, and also prove new results on interesting variants

    The development of reading tests for use in a regularly spelled language.

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    Data are presented on the development of tests of reading skill in rural Tanzanian primary school pupils. Instruction in these schools is in Kiswahili, a regularly spelt language. Using a translation of a standard reading test, children could read aloud all words once they had learnt sound-letter correspondences, regardless of comprehension. In addition, children can appear to pass traditional comprehension tasks by decoding only some of the words. Three graded tests were developed which allow testing of children who either have only some letter knowledge, can read single words, or are proficient readers. The tests require children to both decode and understand the reading material in order to achieve high scores. The tests correlated well with scores on other educational achievement tests, and showed age and school grade differences. It is suggested that these tests are useful measures of reading development in a regularly spelt language. Adaptation to English and validation against standardised instruments is planned

    Characterization of hexabundles: Initial results

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    New multi-core imaging fibre bundles -- hexabundles -- being developed at the University of Sydney will provide simultaneous integral field spectroscopy for hundreds of celestial sources across a wide angular field. These are a natural progression from the use of single fibres in existing galaxy surveys. Hexabundles will allow us to address fundamental questions in astronomy without the biases introduced by a fixed entrance aperture. We have begun to consider instrument concepts that exploit hundreds of hexabundles over the widest possible field of view. To this end, we have compared the performance of a 61-core fully-fused hexabundle and 5 lightly-fused bundles with 7 cores each. All fibres in the bundles have 100 micron cores. In the fully-fused bundle, the cores are distorted from a circular shape in order to achieve a higher fill fraction. The lightly-fused bundles have circular cores and five different cladding thicknesses which affect the fill fraction. We compare the optical performance of all 6 bundles and find that the advantage of smaller interstitial holes (higher fill fraction) is outweighed by the increase in modal coupling, cross-talk and the poor optical performance caused by the deformation of the fibre cores. Uniformly high throughput and low cross-talk are essential for imaging faint astronomical targets with sufficient resolution to disentangle the dynamical structure. Devices already under development will have between 100 and 200 lightly-fused cores, although larger formats are feasible. The light-weight packaging of hexabundles is sufficiently flexible to allow existing robotic positioners to make use of them.Comment: Accepted for publication in MNRAS. See also a complimentary paper on the development of hexabundles - Bland-Hawthorn et al. 2011, Optics Express, vol. 19, p. 2649 (http://www.opticsinfobase.org/abstract.cfm?URI=oe-19-3-2649

    Guide to some minerals and rocks in Indiana

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    Indiana Geological Survey Circular 4The study of minerals and rocks is an important part of the science of geology, which treats of the history of the earth and its life, especially as recorded in the rocks. Surprisingly many of us accept as commonplace many of nature's creations because they are so familiar. Actually, we can find the earth we live on a fascinating world if only we open our eyes to see it. Geologically, Indiana is an interesting state. It has many fascinating geologic and scenic prospects in its more rugged regions., and even its flat areas possess much interesting geologic phenomenan. At one time or another everyone probably has been curious about some particular rock or other object originating in the earth. But most of us who have been curious about these rocks or objects could not identify them, and thus our curiosity remained unsatisfied because we could find no explanation for their existence. This circular was prepared with the hope that it may satisfy, at least in part, the curiosity aroused by finding rocks or minerals. It is hoped that those who have discovered rocks and minerals will be encouraged to become further acquainted with their finds by using this guide. It is impossible to cover fully in this brief report all the characteristics and variations of each kind of rock and mineral found in Indiana. For detailed information regarding Indiana geology, the reader should consult the more detailed reports of the Geological Survey and its predecessors.Indiana Department of Conservatio
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