Calibrating Array Detectors

The development of sensitive large format imaging arrays for the infrared promises to provide revolutionary capabilities for space astronomy. For example, the Infrared Array Camera (IRAC) on SIRTF will use four 256 x 256 arrays to provide background limited high spatial resolution images of the sky in the 3 to 8 micron spectral region. In order to reach the performance limits possible with this generation of sensitive detectors, calibration procedures must be developed so that uncertainties in detector calibration will always be dominated by photon statistics from the dark sky as a major system noise source. In the near infrared, where the faint extragalactic sky is observed through the scattered and reemitted zodiacal light from our solar system, calibration is particularly important. Faint sources must be detected on this brighter local foreground. We present a procedure for calibrating imaging systems and analyzing such data. In our approach, by proper choice of observing strategy, information about detector parameters is encoded in the sky measurements. Proper analysis allows us to simultaneously solve for sky brightness and detector parameters, and provides accurate formal error estimates. This approach allows us to extract the calibration from the observations themselves; little or no additional information is necessary to allow full interpretation of the data. Further, this approach allows refinement and verification of detector parameters during the mission, and thus does not depend on a priori knowledge of the system or ground calibration for interpretation of images.Comment: Scheduled for ApJS, June 2000 (16 pages, 3 JPEG figures

ARCADE: Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission

The Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission (ARCADE) is a balloon-borne instrument designed to measure the temperature of the cosmic microwave background at centimeter wavelengths. ARCADE searches for deviations from a blackbody spectrum resulting from energy releases in the early universe. Long-wavelength distortions in the CMB spectrum are expected in all viable cosmological models. Detecting these distortions or showing that they do not exist is an important step for understanding the early universe. We describe the ARCADE instrument design, current status, and future plans.Comment: 12 pages, 6 figures. Proceedings of the Fundamental Physics With CMB workshop, UC Irvine, March 23-25, 2006, to be published in New Astronomy Review

What does successful social prescribing look like? Mapping meaningful outcomes

This study aimed to investigate and collate all the outcomes that are being experienced in link worker based social prescribing schemes. We found this reflects a large evidence gap where research money needs to be invested. Data from this study highlighted that VCSE organisations engaged with social prescribing are not receiving full attribution for their contribution to improving the health and wellbeing of people. Within the literature, there are a range of reports and research articles that support the use of community organisations and services. Little of this knowledge or impact, however, is contextualised within the terms of link worker based social prescribing schemes

ARCADE 2 Measurement of the Extra-Galactic Sky Temperature at 3-90 GHz

The ARCADE 2 instrument has measured the absolute temperature of the sky at frequencies 3, 8, 10, 30, and 90 GHz, using an open-aperture cryogenic instrument observing at balloon altitudes with no emissive windows between the beam-forming optics and the sky. An external blackbody calibrator provides an {\it in situ} reference. Systematic errors were greatly reduced by using differential radiometers and cooling all critical components to physical temperatures approximating the CMB temperature. A linear model is used to compare the output of each radiometer to a set of thermometers on the instrument. Small corrections are made for the residual emission from the flight train, balloon, atmosphere, and foreground Galactic emission. The ARCADE 2 data alone show an extragalactic rise of $50\pm7$ mK at 3.3 GHz in addition to a CMB temperature of $2.730\pm .004$ K. Combining the ARCADE 2 data with data from the literature shows a background power law spectrum of $T=1.26\pm 0.09$ [K] $(\nu/\nu_0)^{-2.60\pm 0.04}$ from 22 MHz to 10 GHz ($\nu_0=1$ GHz) in addition to a CMB temperature of $2.725\pm .001$ K.Comment: 11 pages 5 figures Submitted to Ap

Challenges and Approaches to Green Social Prescribing During and in the Aftermath of COVID-19: A Qualitative Study

he last decade has seen a surge of interest and investment in green social prescribing, however, both healthcare and social enterprise has been impacted by the COVID-19 crisis, along with restricted access to public green spaces. This study examines the challenges and opportunities of delivering green social prescribing during and in the aftermath of COVID-19, in the light of goals of green social prescribing to improve mental health outcomes and reduce health inequalities. Thirty-five one-to-one interviews were conducted between March 2020 and January 2022. Interviewees included Link Workers and other social prescribers, general practitioners (GPs), managers, researchers, and volunteers working in urban and rural Scotland and North East England. Interview transcripts were analyzed in stages, with an inductive approach to coding supported by NVivo. Findings revealed a complex social prescribing landscape, with schemes funded, structured, and delivered diversely. Stakeholders were in general agreement about the benefits of nature-based interventions, and GPs and volunteers pointed out numerous benefits to participating in schemes such as parkrun. Link Workers were more circumspect about suggesting outdoor activities, pointing out both psychological and practical obstacles, including health anxieties, mobility issues, and transport deficits. Exacerbated by the pandemic, there was a way to go before older and/multi-morbidity clients (their largest cohort) would feel comfortable and safe to socialize in open air spaces. Our findings support the premise that time spent in open green spaces can alleviate some of the negative mental health effects compounded by the pandemic. However, the creation of healthy environments is complex with population health intrinsically related to socioeconomic conditions. Social disadvantage, chronic ill health and health crises all limit easy access to green and blue spaces, while those in the most socially economically deprived areas receive the lowest quality of healthcare. Such health inequities need to be borne in mind in the planning of schemes and claims around the potential of future nature-based interventions to reduce health inequalities

Polarization Properties of A Multi-Moded Concentrator

We present the design and performance of a non-imaging concentrator for use in broad-band polarimetry at millimeter through submillimeter wavelengths. A rectangular geometry preserves the input polarization state as the concentrator couples f/2 incident optics to a 2 pi sr detector. Measurements of the co-polar and cross-polar beams in both the few-mode and highly over-moded limits agree with a simple model based on mode truncation. The measured co-polar beam pattern is nearly independent of frequency in both linear polarizations. The cross-polar beam pattern is dominated by a uniform term corresponding to polarization efficiency 94%. After correcting for efficiency, the remaining cross-polar response is -18 dB.Comment: 9 pages including 8 figures. Accepted for publication in the Journal of the Optical Society of America

Weathering the storm: A qualitative study of social prescribing in urban and rural Scotland during the COVID-19 pandemic

Objectives The non-clinical approach known as social prescribing aims to tackle multi-morbidity, reduce GP workload and promote wellbeing by directing patients to community services. Usual in-person modes of delivery of social prescribing have been virtually impossible under social distancing rules. Our study qualitatively examined and compared the responses of three social prescribing schemes in Scotland to the Covid-19 pandemic. Methods We interviewed a theoretical sample of 23 stakeholders of urban and rural social prescribing schemes at the start of Covid-19 pandemic. Follow up interviews with a representative sample were conducted around ten months later. Interviewees included social prescribing coordinators (SPCs) GPs, managers, researchers and representatives of third sector organizations. Interview transcripts were analysed in stages and an inductive approach to coding was supported by NVivo. Results Findings revealed a complex social prescribing landscape in Scotland with schemes funded, structured and delivering services, in diverse ways. Across all schemes, working effectively during the pandemic and shifting to online delivery had been challenging and demanding, however their priorities in response to the pandemic had differed. With GP time and services stretched to limits, GP practice-attached ‘Link Workers’ had taken on counselling and advocacy roles, sometimes for serious mental health cases. Community-based SPCs had mostly assumed a health education role, and those on the Western Isles of Scotland a digital support role. In both rural or urban areas, combatting loneliness and isolation- especially given social distancing- remained a pivotal aspect of the SPC role. Conclusions Our study highlights significant challenges and shifts in focus in social prescribing in response to the pandemic. Use of multiple digital technologies has assumed a central role in social prescribing and this situation seems likely to remain. With statutory and non-statutory services stretched to their limits, there is a danger of SPCs assuming new tasks without adequate training or support

Stopping relativistic Xe, Ho, Au and U nuclei in nuclear emulsions

Nuclei of Xe-54, Ho-67, Au-79 and U-92 accelerated at the Bevalac to energies between 1200 and 900 MeV/n were stopped in nuclear emulsions. The observed residual ranges were compared with those calculated from various models of energy loss and shown to be most consistent with a calculation that includes those higher order correction terms proposed previously to describe the energy loss of highly charged particles, for which the first Born approximation is not valid

Self-care and entrepreneurism: An ethnography of soft skills development for higher education staff

Despite the ubiquity of staff soft skills programmes, few studies have examined why and how academic and corporate services staff utilise these programmes for self-care/governance. This study reports on findings from an ethnography of soft-skills learning and development programmes (LDPs) in a UK university, focusing on interviews with programme participants and facilitators. Results suggest that, as social worlds with neoliberal directives, LDPs promote various self-governance activities in the form of entrepreneurism and novel, corporate versions of self-care. Time on LDPs was seen as a chance to, ‘put oneself first,’ examine career options and cultivate sought-after attributes, including self-confidence and assertiveness. Social networking and performance management also emerged as significant issues. Career development was important for all participants; however, perceptions of how to realise this differed. Based on our findings, we propose three types of work-related performance – ‘career nomad,’ ‘reluctant entrepreneur,’ and ‘course hopper’ – constituting a typology for understanding social worlds inhabited by contemporary university professionals. Our study suggests that self-care ‘technologies’ have multiple, competing functions in continuing professional education. While LDPs can help professionals navigate paths through increasingly turbulent organisations, their entrepreneurial ethos and content reflect the market interests they serve