5,295 research outputs found

    Sensitivity of a Bolometric Interferometer to the CMB power spectrum

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    Context. The search for B-mode polarization fluctuations in the Cosmic Microwave Background is one of the main challenges of modern cosmology. The expected level of the B-mode signal is very low and therefore requires the development of highly sensitive instruments with low systematic errors. An appealing possibility is bolometric interferometry. Aims. We compare in this article the sensitivity on the CMB angular power spectrum achieved with direct imaging, heterodyne and bolometric interferometry. Methods. Using a simple power spectrum estimator, we calculate its variance leading to the counterpart for bolometric interferometry of the well known Knox formula for direct imaging. Results. We find that bolometric interferometry is less sensitive than direct imaging. However, as expected, it is finally more sensitive than heterodyne interferometry due to the low noise of the bolometers. It therefore appears as an alternative to direct imagers with different and possibly lower systematic errors, mainly due to the absence of an optical setup in front of the horns.Comment: 5 pages, 3 figures. This last version matches the published version (Astronomy and Astrophysics 491 3 (2008) 923-927). Sensitivity of Heterodyne Interferometers modified by a factor of tw

    The child attachment style interview (Child-ASI) and depression: preliminary findings

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    Background: Childhood familial trauma is a major contributor to psychological disorder. One of its key impacts is insecure attachment style, which impedes the development of close relationships. Trauma-related vulnerability is important to assess in primary school but there is a gap in age-appropriate measurement tools. This paper outlines the development of the Child Attachment Style Interview (Child-ASI) suitable for 6 to 11-year olds. This can be utilised on-site to identify damaging effects of trauma experience at an early stage. Method: The Child-ASI was developed from an existing adolescent/adult measure and tested on a sample of children in primary school (N=42) together with a subsample of those in care (N=20). A checklist of life events and the Mood and Feeling Questionnaire (MFQ) for depression was also administered. Results: Acceptable inter-rater reliability was found ([kappa]=0.84 for overall attachment style). A factor analysis of subscales produced the expected five factors for classification. Rates of insecure styles (38 per cent in school and 90 per cent in care) were consistent with other studies and related to separation from parent and depression. Logistic regression showed insecure attachment style and negative life events provided the best model for depression. Conclusion: Preliminary findings indicate the Child-ASI provides an effective way of assessing attachment style in children. Its use is for more intensive investigation of trauma-related interpersonal problems, administered by trained teachers. It is less intrusive than direct trauma assessments and fits with the policy need to identify vulnerability for mental health issues in schools

    Setting priorities to inform assessment of care homes’ readiness to participate in healthcare innovation: a systematic mapping review and consensus process

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    © 2020 The Author(s). This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly citedOrganisational context is known to impact on the successful implementation of healthcare initiatives in care homes. We undertook a systematic mapping review to examine whether researchers have considered organisational context when planning, conducting, and reporting the implementation of healthcare innovations in care homes. Review data were mapped against the Alberta Context Tool, which was designed to assess organizational context in care homes. The review included 56 papers. No studies involved a systematic assessment of organisational context prior to implementation, but many provided post hoc explanations of how organisational context affected the success or otherwise of the innovation. Factors identified to explain a lack of success included poor senior staff engagement, non-alignment with care home culture, limited staff capacity to engage, and low levels of participation from health professionals such as general practitioners (GPs). Thirty-five stakeholders participated in workshops to discuss findings and develop questions for assessing care home readiness to participate in innovations. Ten questions were developed to initiate conversations between innovators and care home staff to support research and implementation. This framework can help researchers initiate discussions about health-related innovation. This will begin to address the gap between implementation theory and practice.Peer reviewe

    Mobile Computing in Physics Analysis - An Indicator for eScience

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    This paper presents the design and implementation of a Grid-enabled physics analysis environment for handheld and other resource-limited computing devices as one example of the use of mobile devices in eScience. Handheld devices offer great potential because they provide ubiquitous access to data and round-the-clock connectivity over wireless links. Our solution aims to provide users of handheld devices the capability to launch heavy computational tasks on computational and data Grids, monitor the jobs status during execution, and retrieve results after job completion. Users carry their jobs on their handheld devices in the form of executables (and associated libraries). Users can transparently view the status of their jobs and get back their outputs without having to know where they are being executed. In this way, our system is able to act as a high-throughput computing environment where devices ranging from powerful desktop machines to small handhelds can employ the power of the Grid. The results shown in this paper are readily applicable to the wider eScience community.Comment: 8 pages, 7 figures. Presented at the 3rd Int Conf on Mobile Computing & Ubiquitous Networking (ICMU06. London October 200

    VLTI/MIDI 10 micron interferometry of the forming massive star W33A

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    We report on resolved interferometric observations with VLTI/MIDI of the massive young stellar object (MYSO) W33A. The MIDI observations deliver spectrally dispersed visibilities with values between 0.03 and 0.06, for a baseline of 45m over the wavelength range 8-13 micron. The visibilities indicate that W33A has a FWHM size of approximately 120AU (0.030'') at 8 micron which increases to 240AU at 13 micron, scales previously unexplored among MYSOs. This observed trend is consistent with the temperature falling off with distance. 1D dust radiative transfer models are simultaneously fit to the visibility spectrum, the strong silicate feature and the shape of the mid infrared spectral energy distribution (SED). For any powerlaw density distribution, we find that the sizes (as implied by the visibilities) and the stellar luminosity are incompatible. A reduction to a third of W33A's previously adopted luminosity is required to match the visibilities; such a reduction is consistent with new high resolution 70 micron data from Spitzer's MIPSGAL survey. We obtain best fits for models with shallow dust density distributions of r^(-0.5) and r^(-1.0) and for increased optical depth in the silicate feature produced by decreasing the ISM ratio of graphite to silicates and using optical grain properties by Ossenkopf et al. (1992).Comment: 4 pages, 4 figures. Accepted for ApJ letter

    Mosaicking with cosmic microwave background interferometers

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    Measurements of cosmic microwave background (CMB) anisotropies by interferometers offer several advantages over single-dish observations. The formalism for analyzing interferometer CMB data is well developed in the flat-sky approximation, valid for small fields of view. As the area of sky is increased to obtain finer spectral resolution, this approximation needs to be relaxed. We extend the formalism for CMB interferometry, including both temperature and polarization, to mosaics of observations covering arbitrarily large areas of the sky, with each individual pointing lying within the flat-sky approximation. We present a method for computing the correlation between visibilities with arbitrary pointing centers and baselines and illustrate the effects of sky curvature on the l-space resolution that can be obtained from a mosaic.Comment: 9 pages; submitted to Ap

    Systematic Errors in Cosmic Microwave Background Interferometry

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    Cosmic microwave background (CMB) polarization observations will require superb control of systematic errors in order to achieve their full scientific potential, particularly in the case of attempts to detect the B modes that may provide a window on inflation. Interferometry may be a promising way to achieve these goals. This paper presents a formalism for characterizing the effects of a variety of systematic errors on interferometric CMB polarization observations, with particular emphasis on estimates of the B-mode power spectrum. The most severe errors are those that couple the temperature anisotropy signal to polarization; such errors include cross-talk within detectors, misalignment of polarizers, and cross-polarization. In a B mode experiment, the next most serious category of errors are those that mix E and B modes, such as gain fluctuations, pointing errors, and beam shape errors. The paper also indicates which sources of error may cause circular polarization (e.g., from foregrounds) to contaminate the cosmologically interesting linear polarization channels, and conversely whether monitoring of the circular polarization channels may yield useful information about the errors themselves. For all the sources of error considered, estimates of the level of control that will be required for both E and B mode experiments are provided. Both experiments that interfere linear polarizations and those that interfere circular polarizations are considered. The fact that circular experiments simultaneously measure both linear polarization Stokes parameters in each baseline mitigates some sources of error.Comment: 19 pages, 9 figures, submitted to Phys. Rev.

    Does Gener Impact the Immune Response of Chicks?

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    Sequencing technology allows us tosee how the gene expression of each genechanges under different treatment conditions. In this study, chicks of two inbred lines were challenged with Newcastle Disease Virus (NDV), a pathogen with devastating impacts on poultry throughout the world. At each of the three time points post-infection, one-third of the chicks were sacraficed and their lungs were harvested. When comparing males and females infected with NDV, differences in gene expression that were predicted to impact growth and apoptosis were identified. Differences between the response of males and females to viral challenges could be useful information for production operations. The interaction between production traits and immune related traits require further study

    UC-432 CCSE Reservation Application

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    This CCSE Reservation Application project is focused on creating a unified web application to simplify the reservation process for inventory devices and room time slots for faculty and staff at Kennesaw State University. This initiative combines two separate reservation systems into a single solution, encompassing a database, backend, and frontend. The database will store relevant information, the backend will handle data communication, and the frontend will provide a user-friendly interface for making reservations. Administrators will have access to an admin view for managing requests. The project has faced challenges, including resource constraints and team coordination issues. While the integration of the university\u27s login system remains pending at the time of submission, the application is on track to deliver a functioning reservation system for devices and rooms
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