1,877 research outputs found

    Cluster Morphologies and Model-independent Y_(SZ) Estimates from Bolocam Sunyaev-Zel'dovich Images

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    We present initial results from our ongoing program to image the Sunyaev-Zel'dovich (SZ) effect in galaxy clusters at 143 GHz using Bolocam; five clusters and one blank field are described in this manuscript. The images have a resolution of 58 arcsec and a radius of ≃ 6-7 arcmin, which is approximately r_(500)-2r_(500) for these clusters. We effectively high-pass filter our data in order to subtract noise sourced by atmospheric fluctuations, but we are able to obtain unbiased images of the clusters by deconvolving the effects of this filter. The beam-smoothed rms is ≃ 10 ÎŒK_(CMB) in these images; with this sensitivity, we are able to detect the SZ signal to beyond r_(500) in binned radial profiles. We have fit our images to beta and Nagai models, fixing spherical symmetry or allowing for ellipticity in the plane of the sky, and we find that the best-fit parameter values are in general consistent with those obtained from other X-ray and SZ data. Our data show no clear preference for the Nagai model or the beta model due to the limited spatial dynamic range of our images. However, our data show a definitive preference for elliptical models over spherical models, quantified by an F ratio of ≃ 20 for the two models. The weighted mean ellipticity of the five clusters is Ï” = 0.27 ± 0.03, consistent with results from X-ray data. Additionally, we obtain model-independent estimates of Y_(500), the integrated SZ y-parameter over the cluster face to a radius of r_(500), with systematics-dominated uncertainties of ≃ 10%. Our Y_(500) values, which are free from the biases associated with model-derived Y_(500) values, scale with cluster mass in a way that is consistent with both self-similar predictions and expectations of a ≃ 10% intrinsic scatter

    Two novel approaches to the content analysis of school mathematics textbooks

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    The analysis of the content of school textbooks, particularly in a time of cross-cultural borrowing, is a growing field restricted by the tools currently available. In this paper, drawing on the analyses of three English year-one mathematics textbooks, we show how two approaches to the analysis of sequential data not only supplement conventional frequency analyses but highlight trends in the content of such textbooks hidden from frequency analyses alone. The first, moving averages, is conventionally used in science to eliminate noise and demonstrate trends in data. The second, Lorenz curves, is typically found in the social sciences to compare different forms of social phenomena. Both, as we show, extend the range of questions that can be meaningfully asked of textbooks. Finally, we speculate as to how both approaches can be used with other forms of ordered classroom data

    EXAFS study of nickel tetracarbonyl and nickel clusters in zeolite Y

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    Adsorption and thermal decomposition of Ni(CO)4 in the cage system of zeolite Y have been studied with EXAFS, electron microscopy and IR spectroscopy , Ni(CO)4 is adsorbed as an intact molecule in both cation - free zeolite Y and NaY. Symmetry changes of the molecule in NaY are assigned to the formation of Na—OC-IMi bridges. Thermal treatment of the Ni(CO)4/NaY adduct leads to loss of CO concomitant with the formation of a binodal Ni phase. A major part of the forms clusters with diameter between 0.5 and about 1.5 nm, in addition to larger crystallites (5-30 nm), sticking at the outer surface of the zeolite matrix., The Ni-Ni scattering amplitude indicates increasing average particle size with increasing temperature

    Sensitization of renal carcinoma cells to TRAIL-induced apoptosis by rocaglamide and analogs

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    Rocaglamide has been reported to sensitize several cell types to TRAIL-induced apoptosis. In recent years, advances in synthetic techniques have led to generation of novel rocaglamide analogs. However, these have not been extensively analyzed as TRAIL sensitizers, particularly in TRAIL-resistant renal cell carcinoma cells. Evaluation of rocaglamide and analogs identified 29 compounds that are able to sensitize TRAIL-resistant ACHN cells to TRAIL-induced, caspase-dependent apoptosis with sub-”M potency which correlated with their potency as protein synthesis inhibitors and with loss of cFLIP protein in the same cells. Rocaglamide alone induced cell cycle arrest, but not apoptosis. Rocaglates averaged 4–5-fold higher potency as TRAIL sensitizers than as protein synthesis inhibitors suggesting a potential window for maximizing TRAIL sensitization while minimizing effects of general protein synthesis inhibition. A wide range of other rocaglate effects (e.g. on JNK or RAF-MEK-ERK signaling, death receptor levels, ROS, ER stress, eIF4E phosphorylation) were assessed, but did not contribute to TRAIL sensitization. Other than a rapid loss of MCL-1, rocaglates had minimal effects on mitochondrial apoptotic pathway proteins. The identification of structurally diverse/mechanistically similar TRAIL sensitizing rocaglates provides insights into both rocaglate structure and function and potential further development for use in RCC-directed combination therapy.This project has been funded in whole or in part with Federal funds from the National Cancer Institute, National Institutes of Health, under Contract No. HHSN261200800001E. The content of this publication does not necessarily reflect the views or policies of the Department of Health and Human Services, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. Government. This research was supported [in part] by the Intramural Research Program of NIH, Frederick. National Lab, Center for Cancer Research. Research performed at Boston University was supported in part by NIH R35 GM118173. Work at the BU-CMD is supported by R24 GM111625. (HHSN261200800001E - National Cancer Institute, National Institutes of Health; Intramural Research Program of NIH, Frederick. National Lab, Center for Cancer Research; R35 GM118173 - NIH; R24 GM111625)Published versio

    Improving access to contraception through integration of family planning services into a multidrug-resistant tuberculosis treatment programme

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    Objectives: Multidrug-resistant tuberculosis (MDR-TB) is a global public health priority. The advent of the World Health Organisation’s Short Course regimen for MDR-TB, which halves treatment duration, has transformed outcomes and treatment acceptability for affected patients. Bedaquiline, a cornerstone of the Short Course regimen, has unknown teratogenicity and the WHO therefore recommends reliable contraception for all female MDR-TB patients in order to secure eligibility for bedaquiline. We were concerned that low contraceptive uptake among female patients in our rural South African MDR-TB treatment programme could jeopardise their access to bedaquiline. We therefore conducted a service delivery improvement project that aimed to audit contraceptive use in female MDR-TB patients, integrate family planning services into MDR-TB care, and increase the proportion of female patients eligible for bedaquiline therapy. Methods: Contraceptive use and pregnancy rates were audited in all female patients aged 13–50 years initiated on our MDR-TB treatment programme in 2016. We then implemented an intervention consisting of procurement of depot-medroxyprogesterone acetate (DMPA) for the MDR-TB unit and training of specialist MDR-TB nurses in administration of DMPA. The audit cycle was repeated for all female patients aged 13–50 years initiated on the programme in January–October 2017 (post-intervention). Results: The proportion of women on injectable contraceptives by the time of MDR-TB treatment initiation increased significantly in the post-intervention cohort (77.4% vs 23.9%, p<0.0001). Conclusion: By integrating contraceptive services into our MDR-TB programme we significantly increased contraceptive uptake, protecting women from the obstetric risks associated with pregnancy during MDR-TB treatment and maximising their eligibility for bedaquiline therapy

    Exploring gender differences within forest schools as a physical activity intervention

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    This study investigated whether children engaged in more physical activity (PA) on school days that included Forest School (FS) sessions than a regular school day or a school day with a Physical Education (PE) lesson. How FS sessions influenced children’s general levels of PA and wellbeing was also explored across gender. A mixed-methods study followed a sample of 59 child participants aged 7 to 9 years old, from four primary schools, whilst taking part in twelve weekly FS sessions. Measures included the PA Questionnaire for Older Children and accelerometry data together with an individual Write and Draw task to inform focus groups. Children had significantly greater levels of light PA on a FS day and a PE school day compared to a regular school day and children reported feeling both happier and relaxed as a consequence of the intervention. From the qualitative data, boys and girls reported different likes of the FS interventions, whereas their dislikes of FS were comparable. Findings from this research provide evidence for such outdoor, nature-based learning within the school curriculum contributing to daily PA in children

    A Search for Cosmic Microwave Background Anisotropies on Arcminute Scales with Bolocam

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    We have surveyed two science fields totaling one square degree with Bolocam at 2.1 mm to search for secondary CMB anisotropies caused by the Sunyaev- Zel'dovich effect (SZE). The fields are in the Lynx and Subaru/XMM SDS1 fields. Our survey is sensitive to angular scales with an effective angular multipole of l_eff = 5700 with FWHM_l = 2800 and has an angular resolution of 60 arcseconds FWHM. Our data provide no evidence for anisotropy. We are able to constrain the level of total astronomical anisotropy, modeled as a flat bandpower in C_l, with frequentist 68%, 90%, and 95% CL upper limits of 590, 760, and 830 uKCMB^2. We statistically subtract the known contribution from primary CMB anisotropy, including cosmic variance, to obtain constraints on the SZE anisotropy contribution. Now including flux calibration uncertainty, our frequentist 68%, 90% and 95% CL upper limits on a flat bandpower in C_l are 690, 960, and 1000 uKCMB^2. When we instead employ the analytic spectrum suggested by Komatsu and Seljak (2002), and account for the non-Gaussianity of the SZE anisotropy signal, we obtain upper limits on the average amplitude of their spectrum weighted by our transfer function of 790, 1060, and 1080 uKCMB^2. We obtain a 90% CL upper limit on sigma8, which normalizes the power spectrum of density fluctuations, of 1.57. These are the first constraints on anisotropy and sigma8 from survey data at these angular scales at frequencies near 150 GHz.Comment: 68 pages, 17 figures, 2 tables, accepted for publication in Ap

    High Spectral Resolution Measurement of the Sunyaev–Zel'dovich Effect Null with Z-Spec

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    The Sunyaev-Zel'dovich (SZ) effect spectrum crosses through a null where ΔT_CMB = 0 near Îœ_0 = 217 GHz. In a cluster of galaxies, Îœ0 can be shifted from the canonical thermal SZ effect value by corrections to the SZ effect scattering due to the properties of the inter-cluster medium. We have measured the SZ effect in the hot galaxy cluster RX J 1347.5 – 1145 with Z-Spec, an R ~ 300 grating spectrometer sensitive between 185 and 305 GHz. These data comprise a high spectral resolution measurement around the null of the SZ effect and clearly exhibit the transition from negative to positive ΔT_CMB over the Z-Spec band. The SZ null position is measured to be Îœ_0 = 225.8 ± 2.5(stat.) ± 1.2(sys.) GHz, which differs from the canonical null frequency by 3.0σ and is evidence for modifications to the canonical thermal SZ effect shape. Assuming the measured shift in Îœ0 is due only to relativistic corrections to the SZ spectrum, we place the limit kT_e = 17.1 ± 5.3 keV from the zero-point measurement alone. By simulating the response of the instrument to the sky, we are able to generate likelihood functions in {y_0, T_e, v_pec} space. For v_pec = 0 km s^(–1), we measure the best-fitting SZ model to be y_0 = 4.6^(+0.6)_(–0.9) × 10^(–4), T_e, 0 = 15.2^(+12)_(–7.4) keV. When v pec is allowed to vary, a most probable value of v_pec = + 450 ± 810 km s^(–1) is found
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