158 research outputs found
Extension Cord: Powering adult education through Cooperative Extension programs
Cooperative Extension provides opportunities for adult learning in a variety of settings. The study identified perceptions of county agents related to their role in community development and adult education
The MeerKAT Galaxy Clusters Legacy Survey: star formation in massive clusters at 0.15 < z < 0.35
We investigate dust-unbiased star formation rates (SFR) as a function of the
environment in 20 massive clusters ()
between using radio luminosities () from the
recently released MeerKAT Galaxy Cluster Legacy Survey catalogue. We use
optical data from the Dark Energy Camera Legacy Survey to estimate photo-s
and assign cluster membership. We observe a steady decline in the fraction
() of star-forming galaxies from to the cluster centres
in our full cluster sample, but notice a significant difference in
gradients between clusters hosting large-scale extended radio emission in the
form of haloes and relics (associated with ongoing merger activity) and
non-radio-halo/relic hosting clusters. For star-forming galaxies within
, the in clusters hosting radio haloes and relics
() is higher than in non-radio-halo/relic hosting
clusters (). We observe a difference between the total
SFR normalised by cluster mass for non-radio-halo/relic hosting clusters
( Myr/M) and for clusters with
radio haloes and relics (
Myr/M). There is a decline
in the mass normalised total SFR of clusters for galaxies with SFR above the
luminous infrared galaxies (LIRGs) SFR limit at our redshift slice,
corresponding to 2 Gyr in look-back time. This is consistent with the rapid
decline in SF activity with decreasing redshift amongst cluster LIRGs seen by
previous studies using infrared-derived SFR.Comment: 13 pages, 9 figures. To be published in MNRA
The Polarization of Ambient Noise on Mars
Seismic noise recorded at the surface of Mars has been monitored since February 2019,
using the InSight seismometers. This noise can reach −200 dB. It is 500 times lower than on Earth at night and it increases of 30 dB during the day. We analyze its polarization as a function of time and frequency in the band 0.03–1 Hz. We use the degree of polarization to extract signals with stable polarization independent of their amplitude and type of polarization. We detect polarized signals at all frequencies and all times. Glitches correspond to linear polarized signals which are more abundant during the night. For signals with elliptical polarization, the ellipse is in the horizontal plane below 0.3 Hz. In the 0.3-1Hz high frequency band (HF) and except in the evening, the ellipse is in the vertical plane and the major axis is tilted. While polarization azimuths are different in the two frequency bands, they both vary as a function of local hour and season. They are also correlated with wind direction, particularly during the daytime. We investigate possible aseismic and seismic origins of the polarized signals. Lander or tether noise can be discarded. Pressure fluctuations transported by wind may explain part of the HF polarization but not the tilt of the ellipse. This tilt can be obtained if the source is an acoustic emission coming from high altitude at critical angle. Finally, in the evening when the wind is low, the measured polarized signals may correspond to the seismic wavefield of the Mars background noise
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Overview of first atmospheric results from InSight
The InSight spacecraft landed in the flat regions of Elysium Planitia on November 26th 2018. The instruments on board InSight make it capable of acting as a meteorological station at the surface of Mars. A pressure sensor (PS), two temperature and wind sensor booms (TWINS), along with the InSight FluxGate (IFG) magnetometer, form the Auxiliary Sensor Payload Suite (APSS). This is complemented by capabilities to measure surface brightness temperature by the radiometer in the Heat-Flow and Physical Properties Package (HP3) suite, to explore the impact of atmospheric processes on seismic measurements by SEIS, and to use InSight cameras to estimate atmospheric opacity (notably caused by suspended dust particles) and other atmospheric phenomena such as clouds and dust devils. We will discuss results drawn from atmospheric measurements on board InSight over the first two months of operation, highlighting new perspectives permitted by the high-frequency, continuous nature of the InSight acquisitions. Surface pressure measurements record global-to-local atmospheric phenomena: CO2 condensation (annual), dust cycle and storms (seasonal), baroclinic waves (weekly), thermal tides (daily), gravity waves (thousands of seconds), convective cells (hundreds of seconds), convective vortices (tens of seconds, leading to dust devils if dust particles are transported in the vortex). Two main large-scale wind regimes were expected from Global Climate Modeling at the InSight landing site during a typical year: towards the northwest in northern spring and summer, then in the opposite direction in southern summer. Existing in-situ measurements on Mars and Large-Eddy Simulations indicate that daytime convective vortices and cells not only impact pressure, but also temperature and winds; the nighttime atmosphere on Mars is comparatively much less turbulent and dominated by shear-driven turbulence, in contrast to the buoyancy-driven turbulence active in daytime. All such existing measurements and model predictions will be compared and challenged with InSight measurements. Seismic signatures associated with atmospheric phenomena will also be discussed, with a particular emphasis on the knowledge gained by the unprecedented measurements performed by InSight’s seismometers
How does study quality affect the results of a diagnostic meta-analysis?
Background: The use of systematic literature review to inform evidence based practice in diagnostics is rapidly expanding. Although the primary diagnostic literature is extensive, studies are often of low methodological quality or poorly reported. There has been no rigorously evaluated, evidence based tool to assess the methodological quality of diagnostic studies. The primary objective of this study was to determine the extent to which variations in the quality of primary studies impact the results of a diagnostic meta-analysis and whether this differs with diagnostic test type. A secondary objective was to contribute to the evaluation of QUADAS, an evidence-based tool for the assessment of quality in diagnostic accuracy studies. Methods: This study was conducted as part of large systematic review of tests used in the diagnosis and further investigation of urinary tract infection (UTI) in children. All studies included in this review were assessed using QUADAS, an evidence-based tool for the assessment of quality in systematic reviews of diagnostic accuracy studies. The impact of individual components of QUADAS on a summary measure of diagnostic accuracy was investigated using regression analysis. The review divided the diagnosis and further investigation of UTI into the following three clinical stages: diagnosis of UTI, localisation of infection, and further investigation of the UTI. Each stage used different types of diagnostic test, which were considered to involve different quality concerns. Results: Many of the studies included in our review were poorly reported. The proportion of QUADAS items fulfilled was similar for studies in different sections of the review. However, as might be expected, the individual items fulfilled differed between the three clinical stages. Regression analysis found that different items showed a strong association with test performance for the different tests evaluated. These differences were observed both within and between the three clinical stages assessed by the review. The results of regression analyses were also affected by whether or not a weighting (by sample size) was applied. Our analysis was severely limited by the completeness of reporting and the differences between the index tests evaluated and the reference standards used to confirm diagnoses in the primary studies. Few tests were evaluated by sufficient studies to allow meaningful use of meta-analytic pooling and investigation of heterogeneity. This meant that further analysis to investigate heterogeneity could only be undertaken using a subset of studies, and that the findings are open to various interpretations. Conclusion: Further work is needed to investigate the influence of methodological quality on the results of diagnostic meta-analyses. Large data sets of well-reported primary studies are needed to address this question. Without significant improvements in the completeness of reporting of primary studies, progress in this area will be limited
A multiwavelength dynamical state analysis of ACT-CL J0019.6+0336
In our study, we show a multiwavelength view of ACT-CL J0019.6+0336 (which hosts a radio halo), to investigate the cluster dynamics, morphology, and ICM. We use a combination of XMM-Newton images, Dark Energy Survey (DES) imaging and photometry, SDSS spectroscopic information, and 1.16 GHz MeerKAT data to study the cluster properties. Various X-ray and optical morphology parameters are calculated to investigate the level of disturbance. We find disturbances in two X-ray parameters and the optical density map shows elongated and axisymmetric structures with the main cluster component southeast of the cluster centre and another component northwest of the cluster centre. We also find a BCG offset of ~950 km/s from the mean velocity of the cluster, and a discrepancy between the SZ mass, X-ray mass, and dynamical mass (MX,500 and MSZ,500 lies > 3σ away from Mdyn,500), showing that J0019 is a merging cluster and probably in a post-merging phase
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First Atmospheric Results from InSight APSS
NASA’s Mars InSight Spacecraft landed on Nov 26, 2018 (Ls=295°) in Elysium Planitia (~4.5°N, 136°E). InSight’s main scientific purpose is to investigate the interior structure and heat flux from Mars, but it is also equipped with instrumentation that can serve as a very capable meteorological station. To remove unwanted environmental noise from the seis- mic signals, InSight carries a very precise pressure sensor (PS) and the first magnetometer (IFG) to the surface of Mars. Additionally, to aid in removing the atmospheric pressure-induced seismic noise, and to identify periods when wind-induced seismic noise may reduce sensitivity, InSight also carries a pair of Wind and Air temperature sensors (TWINS). These three sensors comprise the Auxiliary Payload Sensor Suite (APSS) [1]. Complementing this are a radiometer in the HP3 suite to measure surface radiance, the seismic measurements of SEIS which can record interesting atmospheric phenomena, and the InSight cameras to image clouds and dust devils and estimate atmospheric opacity from dust or clouds. The Lander also carried accelerometers that can be used to reconstruct the at- mospheric structure during descent. We will discuss results drawn from atmospheric measurements on board InSight from the first months of operation, high- lighting the new perspectives permitted by the novel high-frequency, and continuous nature of the InSight data acquisition. Details on pre-landing scientific perspectives for atmospheric science with InSight are found in [2]
How do informal information sources influence women’s decision-making for birth? A meta-synthesis of qualitative studies
Background: Women approach birth using various methods of preparation drawing from conventional healthcare providers alongside informal information sources (IIS) outside the professional healthcare context. An investigation of the forms in which these informal information sources are accessed and negotiated by women, and how these disconnected and often conflicting elements influence women’s decision-making process for birth have yet to be evaluated. The level of antenatal preparedness women feel can have significant and long lasting implications on their birth experience and transition into motherhood and beyond. The aim of this study was to provide a deeper understanding of how informal information sources influence women’s preparation for birth. Methods: Seven electronic databases were searched with predetermined search terms. No limitations were imposed for year of publication. English language studies using qualitative methods exploring women’s experiences of informal information sources and their impact upon women’s birth preparation were included, subject to a quality appraisal framework. Searches were initiated in February 2016 and completed by March 2016. Studies were synthesised using an interpretive meta-ethnographic approach. Results: Fourteen studies were included for the final synthesis from Great Britain, Australia, Canada and the United States. Four main themes were identified: Menu Birth; Information Heaven/Hell; Spheres of Support; and Trust. It is evident that women do not enter pregnancy as empty vessels devoid of a conceptual framework, but rather have a pre-constructed embodied knowledge base upon which other information is superimposed. Allied to this, it is clear that informal information was sought to mitigate against the widespread experience of discordant information provided by maternity professionals. Conclusion: Women’s access to the deluge of informal information sources in mainstream media during pregnancy have significant impact on decision making for birth. These informal sources redefine the power dynamic between women and maternal healthcare providers, simultaneously increasing levels of anxiety and challenging women’s pre- existing ideations and aspirations of personal birth processes. A lack of awareness by some professionals of women’s information seeking behaviours generates barriers to women-centred support, leaving an experience expectation mismatch unchecked
Voiding urosonography with ultrasound contrast agents for the diagnosis of vesicoureteric reflux in children: I. Procedure
Voiding urosonography (VUS) encompasses examination of the urinary tract with intravesical administration of US contrast agent (UCA) for diagnosis of vesicoureteric reflux (VUR). The real breakthrough for US examination of VUR came with the availability of stabilized UCAs in the mid-1990s. This article presents a comprehensive review of various procedural aspects of VUS. Different US modalities are available for detecting the echogenic microbubbles: fundamental mode, colour Doppler US, harmonic imaging and dedicated contrast imaging with multiple display options. The reflux is graded (1 to 5) in a similar manner to the system used in voiding cystourethrography (VCUG). The most commonly used UCA for VUS, Levovist, is galactose-based and contains air-filled microbubbles. The recommended concentration is 300 mg/ml at a dose of 5–10%, or less than 5%, of the bladder filling volume when using fundamental or harmonic imaging modes, respectively. There are preliminary reports of VUS using a second-generation UCA, SonoVue. Here the UCA volume is less than 1% of the bladder filling volume. There is no specific contraindication to intravesical administration of UCA. The safety profile of intravesical Levovist is very high with no reports of side effects over a decade of use in VUS
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