285 research outputs found

    Design and characterization of the POLARBEAR-2b and POLARBEAR-2c cosmic microwave background cryogenic receivers

    Full text link
    The POLARBEAR-2/Simons Array Cosmic Microwave Background (CMB) polarization experiment is an upgrade and expansion of the existing POLARBEAR-1 (PB-1) experiment, located in the Atacama desert in Chile. Along with the CMB temperature and EE-mode polarization anisotropies, PB-1 and the Simons Array study the CMB BB-mode polarization anisotropies produced at large angular scales by inflationary gravitational waves, and at small angular scales by gravitational lensing. These measurements provide constraints on various cosmological and particle physics parameters, such as the tensor-to-scalar ratio rr, and the sum of the neutrino masses. The Simons Array consists of three 3.5 m diameter telescopes with upgraded POLARBEAR-2 (PB-2) cryogenic receivers, named PB-2a, -2b, and -2c. PB-2a and -2b will observe the CMB over multiple bands centered at 95 GHz and 150 GHz, while PB-2c will observe at 220 GHz and 270 GHz, which will enable enhanced foreground separation and de-lensing. Each Simons Array receiver consists of two cryostats which share the same vacuum space: an optics tube containing the cold reimaging lenses and Lyot stop, infrared-blocking filters, and cryogenic half-wave plate; and a backend which contains the focal plane detector array, cold readout components, and millikelvin refrigerator. Each PB-2 focal plane array is comprised of 7,588 dual-polarization, multi-chroic, lenslet- and antenna-coupled, Transition Edge Sensor (TES) bolometers which are cooled to 250 mK and read out using Superconducting Quantum Interference Devices (SQUIDs) through a digital frequency division multiplexing scheme with a multiplexing factor of 40. In this work we describe progress towards commissioning the PB-2b and -2c receivers including cryogenic design, characterization, and performance of both the PB-2b and -2c backend cryostats.Comment: 20 page

    Protocol for the process evaluation of the Promoting Activity, Independence and stability in early Dementia (PrAISED), following changes required by the COVID-19 pandemic

    Get PDF
    Introduction. The PrAISED Randomised Controlled Trial (RCT) is evaluating a home-based, face-to-face, individually tailored, activity and exercise programme for people living with dementia. Social distancing requirements following the COVID-19 pandemic necessitated rapid changes to intervention delivery. Methods and analysis. A mixed methods process evaluation will investigate how the changes were implemented and the impact that these have on participants’ experience. An implementation study will investigate how the intervention was delivered during the pandemic. A study on the mechanisms of impact and context will investigate how these changes were experienced by the PrAISED participants, their carers and the therapists delivering the intervention. The study will commence in May 2020. Ethics and dissemination. The PrAISED RCT and process evaluation have received ethical approval number 18/YH/0059. The ISRCTN Registration Number for PrAISED is 15320670. The PrAISED process evaluation will enable us to understand how distancing and isolation affected participants, their activity and exercise routines, and whether the therapy programme could be continued with remote support. This will be valuable both in explaining trial results, and also contribute to understanding and designing new ways of delivering home-based services and rehabilitation interventions for people with dementia and their carers

    The Impact of a Dementia-Friendly Exercise Class on People Living with Dementia: A Mixed-Methods Study

    Get PDF
    Exercise has multiple benefits for people living with dementia. A programme of group exercise classes for people with dementia and their family carers has been established in a University sports centre. This study aims to explore the impact of this programme on participants with dementia and their carers. A mixed-methods design including a prospective, repeated measures cohort study followed by focus groups was employed. Physiological and cognitive outcome measures were repeated at baseline and three months in a cohort of people with dementia attending a group exercise class. Focus groups on the participants’ experiences and their perceptions of the impact of the exercise class on their lives were then conducted. The results were analysed and mapped on a model, to illustrate the components that most likely promote participation. Sixteen participants (n = 8 with dementia, and n = 8 carers) were recruited, and completed both baseline and follow up assessments. Positive mean differences were found in physical activity (4.44), loneliness (1.75), mood (1.33) and cognition (1.13). Ten participants were included in the focus groups, which found that accessibility of the exercise venue, opportunities for socialisation and staff who were experienced working with people living with dementia were key to participants reporting benefits. The four key themes from the focus group data were synthesised to produce a model outlining the components that might generate a positive impact of the exercise classes and promote participation. Exercise classes for people with dementia can be delivered with success in novel environments such as University sports centres. There is some indication of improvement over a short period of time. The model derived from this study will inform strategies to promote attendance at dementia-friendly exercise classes

    Reducing the Social Gradient in Uptake of the NHS Colorectal Cancer Screening Programme Using a Narrative-Based Information Leaflet: A Cluster-Randomised Trial

    Get PDF
    Objective: To test the effectiveness of adding a narrative leaflet to the current information material delivered by the NHS English colorectal cancer (CRC) screening programme on reducing socioeconomic inequalities in uptake. / Participants: 150,417 adults (59-74 years) routinely invited to complete the guaiac Faecal Occult Blood test (gFOBt) in March 2013. / Design: A cluster randomised controlled trial (ISRCTN74121020) to compare uptake between two arms. The control arm received the standard NHS CRC screening information material (SI) and the intervention arm received the standard information plus a supplementary narrative leaflet, which had previously been shown to increase screening intentions (SI+N). Between group comparisons were made for uptake overall and across socioeconomic status (SES). Results: Uptake was 57.7% and did not differ significantly between the two trial arms (SI: 58.5%; SI+N: 56.7%; Odds Ratio = 0.93, 95% confidence interval: 0.81-1.06, p = 0.27). There was no interaction between group and SES quintile (p = 0.44). / Conclusions: Adding a narrative leaflet to existing information materials does not reduce the SES gradient in uptake. Despite the benefits of using a pragmatic trial design, the need to add to, rather than replace existing information may have limited the true value of an evidence-based intervention on behaviour

    The facilitators and barriers to improving functional activity and wellbeing in people with dementia: a qualitative study from the process evaluation of Promoting Activity, Independence and Stability in Early Dementia (PrAISED)

    Get PDF
    BACKGROUND: The PRomoting Activity, Independence and Stability in Early Dementia (PrAISED) study delivered an exercise and functional activity programme to participants living with dementia. A Randomised Controlled Trial showed no measurable benefits in activities of daily living, physical activity or quality of life. OBJECTIVE: To explore participants' responses to PrAISED and explain why an intervention that might be expected to have produced measurable health gains did not do so. METHODS: A process evaluation using qualitative methods, comprising interviews and researcher notes. SETTING: Data were collected in participants' homes or remotely by telephone or videoconferencing. SAMPLE: A total of 88 interviews were conducted with 44 participants living with dementia (n = 32 intervention group; n = 12 control group) and 39 caregivers. A total of 69 interviews were conducted with 26 therapists. RESULTS: Participants valued the intervention as proactively addressing health issues that were of concern to them, and as a source of social contact, interaction, information and advice. Facilitators to achieving positive outcomes included perceiving progress towards desired goals, positive expectations, therapists' skills and rapport with participants, and caregiver support. Barriers included: cognitive impairment, which prevented independent engagement and carry-over between sessions; chronic physical health problems and intercurrent acute illness and injury; 'tapering' (progressively infrequent supervision intended to help develop habits and independent activity); and the COVID-19 pandemic. CONCLUSIONS: Self-directed interventions may not be appropriate in the context of dementia, even in the mild stages of the condition. Dementia-specific factors affected outcomes including caregiver support, rapport with therapists, availability of supervision, motivational factors and the limitations of remote delivery. The effects of cognitive impairment, multimorbidity and frailty overwhelmed any positive impact of the intervention. Maintenance of functional ability is valued, but in the face of inevitable progression of disease, other less tangible outcomes become important, challenging how we frame 'health gain' and trial outcomes

    A critical role for endocytosis in Wnt signaling

    Get PDF
    BACKGROUND: The Wnt signaling pathway regulates many processes during embryonic development, including axis specification, organogenesis, angiogenesis, and stem cell proliferation. Wnt signaling has also been implicated in a number of cancers, bone density maintenance, and neurological conditions during adulthood. While numerous Wnts, their cognate receptors of the Frizzled and Arrow/LRP5/6 families and downstream pathway components have been identified, little is known about the initial events occurring directly after receptor activation. RESULTS: We show here that Wnt proteins are rapidly endocytosed by a clathrin- and dynamin-mediated process. While endocytosis has traditionally been considered a principal mechanism for receptor down-regulation and termination of signaling pathways, we demonstrate that interfering with clathrin-mediated endocytosis actually blocks Wnt signaling at the level of β-catenin accumulation and target gene expression. CONCLUSION: A necessary component of Wnt signaling occurs in a subcellular compartment distinct from the plasma membrane. Moreover, as internalized Wnts transit partially through the transferrin recycling pathway, it is possible that a "signaling endosome" serves as a nexus for activated Wnt pathway components

    Baby Boomers and the Lost Generation: On the discursive construction of generations at work

    Get PDF
    Generations, and generational categories, offer a means of organising our understandings of age and age-related issues. Particularly within practitioner-orientated debates, differences between generations are highlighted as creating tensions which organisations must address. In contrast, we offer a critical interrogation of generations and unpack the implications of particular constructions. Specifically we examine the discursive construction of generational issues in UK online news about age at work, focusing on baby boomers and the lost generation. We highlight the discursive work involved in constructing each generation as entitled to work and how responsibility for employment issues is variously positioned. These inter-related concerns develop into a debate about consequences, as different versions of the future are constructed. In contrast to essentialised understandings, our study shows how generations and generational categories are constructed and organise understandings of age at work. We further highlight how the constructions of generational differences and tensions become enrolled and legitimate age-related differences with regard to work. Such insights are essential to further our understandings of age-related issues in contemporary organising

    Tele-Rehabilitation for People with Dementia during the COVID-19 Pandemic: A Case-Study from England

    Get PDF
    ntroduction: The Promoting Activity, Independence and Stability in Early Dementia (PrAISED) is delivering an exercise programme for people with dementia. The Lincolnshire part�nership National Health Service (NHS) foundation Trust successfully delivered PrAISED through a video-calling platform during the Coronavirus Disease 2019 (COVID-19) pandemic. Methods: This qualitative case-study aimed to identify participants that video delivery worked for, to highlight its benefits and its challenges. Interviews were conducted between May and August 2020 with five participants with dementia and their caregivers (n = 10), as well as five therapists from the Lincolnshire partnership NHS foundation Trust. The interviews were analysed through thematic analysis. Results: Video delivery worked best when participants had a supporting caregiver and when therapists showed enthusiasm and had an established rapport with the client. Benefits included time efficiency of sessions, enhancing participants’ motivation, caregivers’ dementia awareness, and therapists’ creativity. Limitations included users’ poor IT skills and resources. Discussion: The COVID-19 pandemic required innovative ways of delivering rehabilitation. This study supports that people with dementia can use tele-rehabilitation, but success is reliant on having a caregiver and an enthusiastic and known therapis
    • …
    corecore