1,145 research outputs found
An Assessment of Extension Officers’ Self-Perceived Programming Competencies in Selected Caribbean Countries
Developing the human capacity of extension systems is a necessary part of improving services intended to meet the needs of small farmers. The purpose of this study was to determine the competencies for which professional development is needed in the area of programming for extension officers in selected Caribbean countries. A survey was conducted with all extension officers attending in-service trainings in Belize, Grenada, and Saint Lucia, using the Borich method to identify priority training needs. The greatest needs were most frequently observed in the areas of program planning and evaluation, although considerable variation existed across the group. The resulting challenge is to develop professional development resources that can be individualized by country while remaining cost-effective and accessibl
First Detection of HCO Absorption in the Magellanic System
We present the first detection of HCO absorption in the Magellanic
System. Using the Australia Telescope Compact Array (ATCA), we observed 9
extragalactic radio continuum sources behind the Magellanic System and detected
HCO absorption towards one source located behind the leading edge of the
Magellanic Bridge. The detection is located at LSR velocity of , with a full width at half maximum of and optical depth of .
Although there is abundant neutral hydrogen (HI) surrounding the sightline in
position-velocity space, at the exact location of the absorber the HI column
density is low, , and there is little evidence for dust
or CO emission from Planck observations. While the origin and survival of
molecules in such a diffuse environment remains unclear, dynamical events such
as HI flows and cloud collisions in this interacting system likely play an
important role.Comment: Accepted for publication in ApJ. 6 pages, 2 figures, 2 table
Optical fiber sensors and signal processing for intelligent structure monitoring
The analytic and experimental performance of optical fiber sensors for the control of vibration of large aerospace and other structures are investigated. In particular, model domain optical fiber sensor systems, are being studied due to their apparent potential as distributed, low mass sensors of vibration over appropriate ranges of both low frequency and low amplitude displacements. Progress during the past three months is outlined. Progress since September is divided into work in the areas of experimental hardware development, analytical analysis, control design and sensor development. During the next six months, tests of a prototype closed-loop control system for a beam are planned which will demonstrate the solution of several optical fiber instrumentation device problems, the performance of the control system theory which incorporates the model of the modal domain sensor, and the potential for distributed control which this sensor approach offers
The 21-SPONGE HI Absorption Survey I: Techniques and Initial Results
We present methods and results from "21-cm Spectral Line Observations of
Neutral Gas with the EVLA" (21-SPONGE), a large survey for Galactic neutral
hydrogen (HI) absorption with the Karl G. Jansky Very Large Array (VLA). With
the upgraded capabilities of the VLA, we reach median root-mean-square (RMS)
noise in optical depth of per
channel for the 31 sources presented here. Upon
completion, 21-SPONGE will be the largest HI absorption survey with this high
sensitivity. We discuss the observations and data reduction strategies, as well
as line fitting techniques. We prove that the VLA bandpass is stable enough to
detect broad, shallow lines associated with warm HI, and show that bandpass
observations can be combined in time to reduce spectral noise. In combination
with matching HI emission profiles from the Arecibo Observatory (
angular resolution), we estimate excitation (or spin) temperatures ()
and column densities for Gaussian components fitted to sightlines along which
we detect HI absorption (30/31). We measure temperatures up to for individual lines, showing that we can probe the
thermally unstable interstellar medium (ISM) directly. However, we detect fewer
of these thermally unstable components than expected from previous
observational studies. We probe a wide range in column density between
and for individual HI clouds. In addition,
we reproduce the trend between cold gas fraction and average found by
synthetic observations of a hydrodynamic ISM simulation by Kim et al. (2014).
Finally, we investigate methods for estimating HI and discuss their
biases.Comment: Accepted for publication in ApJ; 24 pages, 14 figure
Essential role for proteinase-activated receptor-2 in arthritis
Using physiological, pharmacological, and gene disruption approaches, we demonstrate that proteinase-activated receptor-2 (PAR-2) plays a pivotal role in mediating chronic inflammation. Using an adjuvant monoarthritis model of chronic inflammation, joint swelling was substantially inhibited in PAR-2-deficient mice, being reduced by more than fourfold compared with wild-type mice, with virtually no histological evidence of joint damage. Mice heterozygous for PAR-2 gene disruption showed an intermediate phenotype. PAR-2 expression, normally limited to endothelial cells in small arterioles, was substantially upregulated 2 weeks after induction of inflammation, both in synovium and in other periarticular tissues. PAR-2 agonists showed potent proinflammatory effects as intra-articular injection of ASKH95, a novel synthetic PAR-2 agonist, induced prolonged joint swelling and synovial hyperemia. Given the absence of the chronic inflammatory response in the PAR-2-deficient mice, our findings demonstrate a key role for PAR-2 in mediating chronic inflammation, thereby identifying a novel and important therapeutic target for the management of chronic inflammatory diseases such as rheumatoid arthritis
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