603 research outputs found

    A Hybrid Implementation-Effectiveness Study of a Community Health Worker-Delivered Intervention to Reduce Cardiovascular Disease Risk in a Rural, Underserved Non-Hispanic Black Population: The CHANGE Study

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    Purpose To evaluate the implementation and effectiveness of the Carolina Heart Alliance Networking for Greater Equity (CHANGE) Program, an adapted evidence-based cardiovascular disease risk reduction intervention delivered by Community Health Workers (CHW) to rural adults. Design Hybrid implementation-effectiveness study with a pre–post design. Setting North Carolina Federally Qualified Health Center and local health department in a rural, medically underserved area. Sample Participants (n = 255) included 87% Non-Hispanic Black with a mean age of 57 years; 84% had diagnosed hypertension, 55% had diabetes, and 65% had hypercholesterolemia. Intervention A CHW-delivered, low-intensity, 4-month behavioral lifestyle intervention promoting a southern-style Mediterranean dietary pattern and physical activity. Measures We measured number and representativeness of participants reached and retained, intervention delivery fidelity, weight, blood pressure, and self-reported dietary and physical activity behaviors. Analysis Pre–post changes at 4 months were analyzed using paired t-tests. Results Study participants completed 90% of planned intervention contacts; 87% were retained. Intervention delivery fidelity measures showed participants receiving a mean of 3.5 counseling visits, 2.7 booster calls, and on average completing 1.7 modules, setting 1.8 goals, and receiving 1.3 referrals per visit. There were significant mean reductions in systolic (−2.5 mmHg, P < .05) and diastolic blood pressure (−2.1 mmHg, P < .01); the proportion of participants with systolic blood pressure <130 increased by 7 % points (P = .05), and diastolic pressure <80 by 9 percentage points (P < .01). Dietary behaviors improved significantly with average weekly servings of nuts increased by .5 serving (P < .0001), and fruits and vegetables by .8 daily serving (P < .0001). Physical activity also increased on average by 45 min./week (P < .001). Weight did not change significantly. Conclusions The CHANGE program showed both implementation and program effectiveness and adds to the evidence supporting CHW-delivered lifestyle interventions to reduce CVD risk among rural, Non-Hispanic Black, and medically underserved populations

    Multi-Gigabit Wireless Link Development

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    CSIRO ICT Centre is developing millimetre wave point-to-point links suitable for multi-gigabit wireless connectivity. Suitable spectrum for this purpose is allocated at the 60 GHz band and above. This paper reports a new point-to-point link that will be installed at Marsfield site to demonstrate multi-gigabit operation and performance of its key components. The link will operate at the 81-86 GHz band incorporating CSIRO designed millimetre wave MMICs and multi-gigabit modems

    The UTMOST: A hybrid digital signal processor transforms the MOST

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    The Molonglo Observatory Synthesis Telescope (MOST) is an 18,000 square meter radio telescope situated some 40 km from the city of Canberra, Australia. Its operating band (820-850 MHz) is now partly allocated to mobile phone communications, making radio astronomy challenging. We describe how the deployment of new digital receivers (RX boxes), Field Programmable Gate Array (FPGA) based filterbanks and server-class computers equipped with 43 GPUs (Graphics Processing Units) has transformed MOST into a versatile new instrument (the UTMOST) for studying the dynamic radio sky on millisecond timescales, ideal for work on pulsars and Fast Radio Bursts (FRBs). The filterbanks, servers and their high-speed, low-latency network form part of a hybrid solution to the observatory's signal processing requirements. The emphasis on software and commodity off-the-shelf hardware has enabled rapid deployment through the re-use of proven 'software backends' for its signal processing. The new receivers have ten times the bandwidth of the original MOST and double the sampling of the line feed, which doubles the field of view. The UTMOST can simultaneously excise interference, make maps, coherently dedisperse pulsars, and perform real-time searches of coherent fan beams for dispersed single pulses. Although system performance is still sub-optimal, a pulsar timing and FRB search programme has commenced and the first UTMOST maps have been made. The telescope operates as a robotic facility, deciding how to efficiently target pulsars and how long to stay on source, via feedback from real-time pulsar folding. The regular timing of over 300 pulsars has resulted in the discovery of 7 pulsar glitches and 3 FRBs. The UTMOST demonstrates that if sufficient signal processing can be applied to the voltage streams it is possible to perform innovative radio science in hostile radio frequency environments.Comment: 12 pages, 6 figure

    A Giant Outburst at Millimeter Wavelengths in the Orion Nebula

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    BIMA observations of the Orion nebula discovered a giant flare from a young star previously undetected at millimeter wavelengths. The star briefly became the brightest compact object in the nebula at 86 GHz. Its flux density increased by more than a factor of 5 on a timescale of hours, to a peak of 160 mJy. This is one of the most luminous stellar radio flares ever observed. Remarkably, the Chandra X-ray observatory was in the midst of a deep integration of the Orion nebula at the time of the BIMA discovery; the source's X-ray flux increased by a factor of 10 approximately 2 days before the radio detection. Follow-up radio observations with the VLA and BIMA showed that the source decayed on a timescale of days, then flared again several times over the next 70 days, although never as brightly as during the discovery. Circular polarization was detected at 15, 22, and 43 GHz, indicating that the emission mechanism was cyclotron. VLBA observations 9 days after the initial flare yield a brightness temperature Tb > 5 x 10^7 K at 15 GHz. Infrared spectroscopy indicates the source is a K5V star with faint Br gamma emission, suggesting that it is a weak-line T Tauri object. Zeeman splitting measurements in the infrared spectrum find B ~ 2.6 +/- 1.0 kG. The flare is an extreme example of magnetic activity associated with a young stellar object. These data suggest that short observations obtained with ALMA will uncover hundreds of flaring young stellar objects in the Orion region.Comment: 29 pages, 7 figures, accepted for publication in Ap

    Pion mass dependence of the Kl3K_{l3} semileptonic scalar form factor within finite volume

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    We calculate the scalar semileptonic kaon decay in finite volume at the momentum transfer tm=(mKmπ)2t_{m} = (m_{K} - m_{\pi})^2, using chiral perturbation theory. At first we obtain the hadronic matrix element to be calculated in finite volume. We then evaluate the finite size effects for two volumes with L=1.83fmL = 1.83 fm and L=2.73fmL= 2.73 fm and find that the difference between the finite volume corrections of the two volumes are larger than the difference as quoted in \cite{Boyle2007a}. It appears then that the pion masses used for the scalar form factor in ChPT are large which result in large finite volume corrections. If appropriate values for pion mass are used, we believe that the finite size effects estimated in this paper can be useful for Lattice data to extrapolate at large lattice size.Comment: 19 pages, 5 figures, accepted for publication in EPJ

    A new layout optimization technique for interferometric arrays, applied to the MWA

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    Antenna layout is an important design consideration for radio interferometers because it determines the quality of the snapshot point spread function (PSF, or array beam). This is particularly true for experiments targeting the 21 cm Epoch of Reionization signal as the quality of the foreground subtraction depends directly on the spatial dynamic range and thus the smoothness of the baseline distribution. Nearly all sites have constraints on where antennas can be placed---even at the remote Australian location of the MWA (Murchison Widefield Array) there are rock outcrops, flood zones, heritages areas, emergency runways and trees. These exclusion areas can introduce spatial structure into the baseline distribution that enhance the PSF sidelobes and reduce the angular dynamic range. In this paper we present a new method of constrained antenna placement that reduces the spatial structure in the baseline distribution. This method not only outperforms random placement algorithms that avoid exclusion zones, but surprisingly outperforms random placement algorithms without constraints to provide what we believe are the smoothest constrained baseline distributions developed to date. We use our new algorithm to determine antenna placements for the originally planned MWA, and present the antenna locations, baseline distribution, and snapshot PSF for this array choice.Comment: 12 pages, 6 figures, 1 table. Accepted for publication in MNRA
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