Decoherence induced by Smith-Purcell radiation

The interaction between charged particles and the vacuum fluctuations of the electromagnetic field induces decoherence, and therefore affects the contrast of fringes in an interference experiment. In this article we show that if a double slit experiment is performed near a conducting grating, the fringe visibility is reduced. We find that the reduction of contrast is proportional to the number of grooves in the conducting surface, and that for realistic values of the parameters it could be large enough to be observed. The effect can be understood in terms of the Smith-Purcell radiation produced by the surface currents induced in the conductor.Comment: 10 pages, 3 figures. Improved discussion on experimental perspectives. References added. Version to appear in Phys. Rev.

Analysis of the Socio-Environmental Impacts of the Proposed Transboundary Highway between Pucallpa, Peru and Cruzeiro do Sul, Brazil

As road building across the Amazon continues to be proposed by both Brazilian and Peruvian governments, it becomes increasingly important to consider the effects this infrastructure could have on diverse Amazonian cultures and ecosystems. One proposal being discussed is a 200 km road that would connect the cities of Pucallpa, Peru and Cruzeiro do Sul, Brazil. While promoted as economically beneficial, the road could infringe upon protected conservation areas and indigenous lands, bringing illegal activity with it as well. This research aims to evaluate the potential impacts the Pucallapa-Cruzeiro do Sul road project presents to the ecosystems, societies, and economies of the southwestern Amazon using a mixed methodology including geospatial analysis, remote sensing, and a literature review of previous studies on the impact of roads in tropical forests. These analyses will attempt to express the scale of the repercussions that road construction may bring to the bioculturally rich Amazon borderlands

Preparing for a Northwest Passage: A Workshop on the Role of New England in Navigating the New Arctic

Preparing for a Northwest Passage: A Workshop on the Role of New England in Navigating the New Arctic (March 25 - 27, 2018 -- The University of New Hampshire) paired two of NSF\u27s 10 Big Ideas: Navigating the New Arctic and Growing Convergence Research at NSF. During this event, participants assessed economic, environmental, and social impacts of Arctic change on New England and established convergence research initiatives to prepare for, adapt to, and respond to these effects. Shipping routes through an ice-free Northwest Passage in combination with modifications to ocean circulation and regional climate patterns linked to Arctic ice melt will affect trade, fisheries, tourism, coastal ecology, air and water quality, animal migration, and demographics not only in the Arctic but also in lower latitude coastal regions such as New England. With profound changes on the horizon, this is a critical opportunity for New England to prepare for uncertain yet inevitable economic and environmental impacts of Arctic change

Health services changes: is a run-in period necessary before evaluation in randomised clinical trials?

Background Most randomised clinical trials (RCTs) testing a new health service do not allow a run-in period of consolidation before evaluating the new approach. Consequently, health professionals involved may feel insufficiently familiar or confident, or that new processes or systems that are integral to the service are insufficiently embedded in routine care prior to definitive evaluation in a RCT. This study aimed to determine the optimal run-in period for a new physiotherapy-led telephone assessment and treatment service known as PhysioDirect and whether a run-in was needed prior to evaluating outcomes in an RCT. Methods The PhysioDirect trial assessed whether PhysioDirect was as effective as usual care. Prior to the main trial, a run-in of up to 12 weeks was permitted to facilitate physiotherapists to become confident in delivering the new service. Outcomes collected from the run-in and main trial were length of telephone calls within the PhysioDirect service and patients’ physical function (SF-36v2 questionnaire) and Measure Yourself Medical Outcome Profile v2 collected at baseline and six months. Joinpoint regression determined how long it had taken call times to stabilise. Analysis of covariance determined whether patients’ physical function at six months changed from the run-in to the main trial. Results Mean PhysioDirect call times (minutes) were higher in the run-in (31 (SD: 12.6)) than in the main trial (25 (SD: 11.6)). Each physiotherapist needed to answer 42 (95% CI: 20,56) calls for their mean call time to stabilise at 25 minutes per call; this took a minimum of seven weeks. For patients’ physical function, PhysioDirect was equally clinically effective as usual care during both the run-in (0.17 (95% CI: -0.91,1.24)) and main trial (-0.01 (95% CI: -0.80,0.79)). Conclusions A run-in was not needed in a large trial testing PhysioDirect services in terms of patient outcomes. A learning curve was evident in the process measure of telephone call length. This decreased during the run-in and stabilised prior to commencement of the main trial. Future trials should build in a run-in if it is anticipated that learning would have an effect on patient outcome

Optimising mothers’ health behaviour after hypertensive disorders of pregnancy: a qualitative study of a postnatal intervention

Background: Hypertensive disorders of pregnancy have longer-term implications, increasing women’s lifetime cardiovascular disease risk. The Blood Pressure Postpartum study is a multi-centre randomised three-arm trial of interventions, ranging in intensity and including education and lifestyle coaching, to support women to maintain or adopt healthy eating and physical activity during the first postpartum year. This qualitative sub-study nested within the main trial aimed to investigate whether and how women adopted healthy behaviours after a pregnancy complicated by a hypertensive disorder. Methods: Semi-structured telephone interviews were recorded, transcribed and analysed thematically, following Braun and Clarke principles. They explored behaviour change among new mothers following their hypertensive pregnancy, and the intervention’s effect on their capacity and motivation to pursue healthy lifestyles. Results: Thirty-four women from all three trial arms participated at 10–12 months postpartum. The three main themes were 1) Awareness of cardiovascular risk: some did not acknowledge the health risks, whereas others embraced this information. 2) Sources of motivation: while the majority were motivated to make a concerted effort to adapt their health behaviour, motivation often centred on their baby and family rather than their own needs. 3) Sustaining behaviour change with a new baby: women in the more intensive intervention arm demonstrated increased recognition of the importance of reducing cardiovascular health risks, with greater motivation and guidance to change their health behaviour. There was minimal evidence of crossover amongst groups, with women largely accepting their randomised level of intervention and not seeking additional help when randomised to minimal intervention. Conclusions: Among women participating in an early post-hypertensive disorders of pregnancy randomised controlled trial aimed at improving their cardiovascular disease risk profile, the majority recognised the future health risks and appeared motivated to improve their lifestyle, particularly women in the highest-intensity intervention group. This highlights the importance of structured support to assist women embrace healthy lifestyles especially during the challenges of new parenthood. Trial registration: The Blood Pressure Postpartum study was prospectively registered as a clinical trial with the Australian New Zealand Clinical Trials Registry (anzctr.org.au) on 13 December 2018 (registration number: ACTRN12618002004246)

Quitting patient care and career break intentions among general practitioners in South West England: findings of a census survey of general practitioners

Objective: Given recent concerns regarding general practitioner (GP) workforce capacity, we aimed to describe GPs’ career intentions, especially those which might impact on GP workforce availability over the next 5 years. Design: Census survey, conducted between April and June 2016 using postal and online responses , of all GPs on the National Health Service performers list and eligible to practise in primary care. Two reminders were used as necessary. Setting: South West England (population 3.5  million), a region with low overall socioeconomic deprivation. Participants: Eligible GPs were 2248 out of 3370 (67 % response rate). Main outcome measures: Reported likelihood of permanently leaving or reducing hours spent in direct patient care or of taking a career break within the next 5 years and present morale weighted for non-response. Results: Responders included 217 7 GPs engaged in patient care. Of these, 863 (37% weighted, 95%  CI 35 % to 39 %) reported a high likelihood of quitting direct patient care within the next 5 years. Overall, 1535 (70% weighted, 95%  CI 68 % to 72 %) respondents reported a career intention that would negatively impact GP workforce capacity over the next 5 years, through permanently leaving or reducing hours spent in direct patient care, or through taking a career break. GP age was an important predictor of career intentions; sharp increases in the proportion of GPs intending to quit patient care were evident from 52 years. Only 305 (14% weighted, 95%  CI 13 % to 16 %) reported high morale, while 1195 ( 54 % weighted, 95%  CI 52 % to 56 %) reported low morale. Low morale was particularly common among GP partners. Current morale strongly predicted GPs’ career intentions; those with very low morale were particularly likely to report intentions to quit patient care or to take a career break. Conclusions: A substantial majority of GPs in South West England report low morale. Many are considering career intentions which, if implemented, would adversely impact GP workforce capacity within a short time period. Study registration: NIHR HS&DR - 14/196/02, UKCRN ID 20700

A trick for passing degenerate points in Ashtekar formulation

We examine one of the advantages of Ashtekar's formulation of general relativity: a tractability of degenerate points from the point of view of following the dynamics of classical spacetime. Assuming that all dynamical variables are finite, we conclude that an essential trick for such a continuous evolution is in complexifying variables. In order to restrict the complex region locally, we propose some `reality recovering' conditions on spacetime. Using a degenerate solution derived by pull-back technique, and integrating the dynamical equations numerically, we show that this idea works in an actual dynamical problem. We also discuss some features of these applications.Comment: 9 pages by RevTeX or 16 pages by LaTeX, 3 eps figures and epsf-style file are include

Altered brain energetics induces mitochondrial fission arrest in Alzheimer's Disease.

Altered brain metabolism is associated with progression of Alzheimer's Disease (AD). Mitochondria respond to bioenergetic changes by continuous fission and fusion. To account for three dimensional architecture of the brain tissue and organelles, we applied 3-dimensional electron microscopy (3D EM) reconstruction to visualize mitochondrial structure in the brain tissue from patients and mouse models of AD. We identified a previously unknown mitochondrial fission arrest phenotype that results in elongated interconnected organelles, "mitochondria-on-a-string" (MOAS). Our data suggest that MOAS formation may occur at the final stages of fission process and was not associated with altered translocation of activated dynamin related protein 1 (Drp1) to mitochondria but with reduced GTPase activity. Since MOAS formation was also observed in the brain tissue of wild-type mice in response to hypoxia or during chronological aging, fission arrest may represent fundamental compensatory adaptation to bioenergetic stress providing protection against mitophagy that may preserve residual mitochondrial function. The discovery of novel mitochondrial phenotype that occurs in the brain tissue in response to energetic stress accurately detected only using 3D EM reconstruction argues for a major role of mitochondrial dynamics in regulating neuronal survival

Gender differences in experiences and expectations of haemodialysis in a frail and seriously unwell patient population

Introduction Surprisingly few studies have explored the experiences of seriously unwell people with kidney disease on haemodialysis therapy: we conducted a mixed-methods study to investigate gender differences in illness experience, symptom burden, treatment considerations or expectations in this cohort. Methods Seriously unwell people on haemodialysis (1-year mortality risk of >20%) at three hospital-based units were invited to take part in a structured interview or to complete the same questions independently via a questionnaire. 54 people took part (36 males, 18 females); data analysis was undertaken using a thematic approach. Results ‘Desire to keep living’ is the most important and basic thought process when starting dialysis. Fear also predominates influencing risk assessment and decision-making. Once fear is managed, there are physical, social, practical and emotional issues to rationalise, but choice only seems possible if shared decision-making is part of the consultation. Gender differences were seen in perceived hopes and expectations of treatment. Males were more likely to prioritise achievement of physical goals, with females prioritising a wish to feel well. Both genders reported significantly higher symptom scores than their healthcare provider perceived, however this difference was more marked in females. Dialysis regret existed in >50% of participants and 6/54 (11%) stated that they would have chosen no dialysis at all. Females were more likely to report feeling depressed (P=0.001). Conclusion Different genders approach treatment decisions and prioritise treatment expectations differently. Recognising this will allow personalised care plans to be developed and improve the experiences of seriously unwell people with kidney disease