Size and shape constancy in consumer virtual reality

With the increase in popularity of consumer virtual reality headsets, for research and other applications, it is important to understand the accuracy of 3D perception in VR. We investigated the perceptual accuracy of near-field virtual distances using a size and shape constancy task, in two commercially available devices. Participants wore either the HTC Vive or the Oculus Rift and adjusted the size of a virtual stimulus to match the geometric qualities (size and depth) of a physical stimulus they were able to refer to haptically. The judgments participants made allowed for an indirect measure of their perception of the egocentric, virtual distance to the stimuli. The data show under-constancy and are consistent with research from carefully calibrated psychophysical techniques. There was no difference in the degree of constancy found in the two headsets. We conclude that consumer virtual reality headsets provide a sufficiently high degree of accuracy in distance perception, to allow them to be used confidently in future experimental vision science, and other research applications in psychology

Quality of private and public ambulatory health care in low and middle income countries: systematic review of comparative studies

Paul Garner and colleagues conducted a systematic review of 80 studies to compare the quality of private versus public ambulatory health care in low- and middle-income countries

Brief of Corporate Law Professors as Amici Curie in Support of Respondents

The Supreme Court has looked to the rights of corporate shareholders in determining the rights of union members and non-members to control political spending, and vice versa. The Court sometimes assumes that if shareholders disapprove of corporate political expression, they can easily sell their shares or exercise control over corporate spending. This assumption is mistaken. Because of how capital is saved and invested, most individual shareholders cannot obtain full information about corporate political activities, even after the fact, nor can they prevent their savings from being used to speak in ways with which they disagree. Individual shareholders have no “opt out” rights or practical ability to avoid subsidizing corporate political expression with which they disagree. Nor do individuals have the practical option to refrain from putting their savings into equity investments, as doing so would impose damaging economic penalties and ignore conventional financial guidance for individual investors

A randomised feasibility study to investigate the impact of education and the addition of prompts on the sedentary behaviour of office workers

Abstract Background Office workers have been identified as being at risk of accumulating high amounts of sedentary time in prolonged events during work hours, which has been associated with increased risk of a number of long-term health conditions. There is some evidence that providing advice to stand at regular intervals during the working day, and using computer-based prompts, can reduce sedentary behaviour in office workers. However, evidence of effectiveness, feasibility and acceptability for these types of intervention is currently limited. Methods A 2-arm, parallel group, cluster-randomised feasibility trial to assess the acceptability of prompts to break up sedentary behaviour was conducted with office workers in a commercial bank (n = 21). Participants were assigned to an education only group (EG) or prompt and education group (PG). Both groups received education on reducing and breaking up sitting at work, and the PG also received hourly prompts, delivered by Microsoft Outlook over 10 weeks, reminding them to stand. Objective measurements of sedentary behaviour were made using activPAL monitors worn at three time points: baseline, in the last 2 weeks of the intervention period and 12 weeks after the intervention. Focus groups were conducted to explore the acceptability of the intervention and the motivations and barriers to changing sedentary behaviour. Results Randomly generated, customised prompts, delivered by Microsoft Outlook, with messages about breaking up sitting, proved to be a feasible and acceptable way of delivering prompts to office workers. Participants in both groups reduced their sitting, but changes were not maintained at follow-up. The education session seemed to increase outcome expectations of the benefits of changing sedentary behaviour and promote self-regulation of behaviour in some participants. However, low self-efficacy and a desire to conform to cultural norms were barriers to changing behaviour. Conclusions Prompts delivered by Microsoft Outlook were a feasible, low-cost way of prompting office workers to break up their sedentary behaviour, although further research is needed to determine whether this has an additional impact on sedentary behaviour, to education alone. The role of cultural norms, and promoting self-efficacy, should be considered in the design of future interventions. Trial registration This study was registered retrospectively as a clinical trial on ClinicalTrials.gov (ID no. NCT02609282 ) on 23 March 2015

STDP Allows Fast Rate-Modulated Coding with Poisson-Like Spike Trains

Spike timing-dependent plasticity (STDP) has been shown to enable single neurons to detect repeatedly presented spatiotemporal spike patterns. This holds even when such patterns are embedded in equally dense random spiking activity, that is, in the absence of external reference times such as a stimulus onset. Here we demonstrate, both analytically and numerically, that STDP can also learn repeating rate-modulated patterns, which have received more experimental evidence, for example, through post-stimulus time histograms (PSTHs). Each input spike train is generated from a rate function using a stochastic sampling mechanism, chosen to be an inhomogeneous Poisson process here. Learning is feasible provided significant covarying rate modulations occur within the typical timescale of STDP (∼10–20 ms) for sufficiently many inputs (∼100 among 1000 in our simulations), a condition that is met by many experimental PSTHs. Repeated pattern presentations induce spike-time correlations that are captured by STDP. Despite imprecise input spike times and even variable spike counts, a single trained neuron robustly detects the pattern just a few milliseconds after its presentation. Therefore, temporal imprecision and Poisson-like firing variability are not an obstacle to fast temporal coding. STDP provides an appealing mechanism to learn such rate patterns, which, beyond sensory processing, may also be involved in many cognitive tasks

A systematic review of frameworks for the interrelationships of mental health evidence and policy in low- and middle-income countries

Background: The interrelationships between research evidence and policy-making are complex. Different theoretical frameworks exist to explain general evidence–policy interactions. One largely unexplored element of these interrelationships is how evidence interrelates with, and influences, policy/political agenda-setting. This review aims to identify the elements and processes of theories, frameworks and models on interrelationships of research evidence and health policy-making, with a focus on actionability and agenda-setting in the context of mental health in low- and middle-income countries (LMICs). Methods: A systematic review of theories was conducted based on the BeHeMOTh search method, using a tested and refined search strategy. Nine electronic databases and other relevant sources were searched for peer-reviewed and grey literature. Two reviewers screened the abstracts, reviewed full-text articles, extracted data and performed quality assessments. Analysis was based on a thematic analysis. The included papers had to present an actionable theoretical framework/model on evidence and policy interrelationships, such as knowledge translation or evidence-based policy, specifically target the agenda-setting process, focus on mental health, be from LMICs and published in English. Results: From 236 publications included in the full text analysis, no studies fully complied with our inclusion criteria. Widening the focus by leaving out ‘agenda-setting’, we included ten studies, four of which had unique conceptual frameworks focusing on mental health and LMICs but not agenda-setting. The four analysed frameworks confirmed research gaps from LMICs and mental health, and a lack of focus on agenda-setting. Frameworks and models from other health and policy areas provide interesting conceptual approaches and lessons with regards to agenda-setting. Conclusion: Our systematic review identified frameworks on evidence and policy interrelations that differ in their elements and processes. No framework fulfilled all inclusion criteria. Four actionable frameworks are applicable to mental health and LMICs, but none specifically target agenda-setting. We have identified agenda-setting as a research theory gap in the context of mental health knowledge translation in LMICs. Frameworks from other health/policy areas could offer lessons on agenda-setting and new approaches for creating policy impact for mental health and to tackle the translational gap in LMICs

Application of the Occupational Sitting and Physical Activity Questionnaire (OSPAQ) to office based workers

Background The workplace is a setting where sedentary behaviour is highly prevalent. Accurately measuring physical activity and sedentary behaviour is crucial to assess the impact of behavioural change interventions. This study aimed to evaluate the reliability and criterion validity of the Occupational Sitting and Physical Activity Questionnaire (OSPAQ) and compare with data collected by accelerometers. Methods A test-retest study was undertaken on 99 participants using the OSPAQ. Data were then compared to accelerometer records of 41 participants. Reliability was assessed by paired t-test and intra-class correlations (ICC) via a two-way mixed model based on absolute agreement. Difference and agreement were measured by comparison of mean self-reported data with accelerometer data using the Pearson’s correlation coefficient and Bland-Altman plots. Results The ICCs for minutes spent sitting (0.66), standing (0.83) and walking (0.77) showed moderate to strong test-retest reliability. No significant differences were found between the repeated measurements taken seven days apart. Correlations with the accelerometer readings were moderate. The Bland-Altman plots showed moderate agreement for standing time and walking time but systematic variation for sedentary time. Conclusion The OSPAQ appears to have acceptable reliability and validity measurement properties for application in the office workplace setting

Barriers to prompt and effective malaria treatment among the poorest population in Kenya

<p>Abstract</p> <p>Background</p> <p>Prompt access to effective malaria treatment is central to the success of malaria control worldwide, but few fevers are treated with effective anti-malarials within 24 hours of symptoms onset. The last two decades saw an upsurge of initiatives to improve access to effective malaria treatment in many parts of sub-Saharan Africa. Evidence suggests that the poorest populations remain least likely to seek prompt and effective treatment, but the factors that prevent them from accessing interventions are not well understood. With plans under way to subsidize ACT heavily in Kenya and other parts of Africa, there is urgent need to identify policy actions to promote access among the poor. This paper explores access barriers to effective malaria treatment among the poorest population in four malaria endemic districts in Kenya.</p> <p>Methods</p> <p>The study was conducted in the poorest areas of four malaria endemic districts in Kenya. Multiple data collection methods were applied including: a cross-sectional survey (n = 708 households); 24 focus group discussions; semi-structured interviews with health workers (n = 34); and patient exit interviews (n = 359).</p> <p>Results</p> <p>Multiple factors related to affordability, acceptability and availability interact to influence access to prompt and effective treatment. Regarding affordability, about 40 percent of individuals who self-treated using shop-bought drugs and 42 percent who visited a formal health facility reported not having enough money to pay for treatment, and having to adopt coping strategies including borrowing money and getting treatment on credit in order to access care. Other factors influencing affordability were seasonality of illness and income sources, transport costs, and unofficial payments. Regarding acceptability, the major interrelated factors identified were provider patient relationship, patient expectations, beliefs on illness causation, perceived effectiveness of treatment, distrust in the quality of care and poor adherence to treatment regimes. Availability barriers identified were related to facility opening hours, organization of health care services, drug and staff shortages.</p> <p><b>Conclusions</b></p> <p>Ensuring that all individuals suffering from malaria have prompt access to effective treatment remains a challenge for resource constrained health systems. Policy actions to address the multiple barriers of access should be designed around access dimensions, and should include broad interventions to revitalize the public health care system. Unless additional efforts are directed towards addressing access barriers among the poor and vulnerable, malaria will remain a major cause of morbidity and mortality in sub-Saharan Africa.</p

Radiotherapy to the prostate for men with metastatic prostate cancer in the UK and Switzerland: Long-term results from the STAMPEDE randomised controlled trial.

BACKGROUND: STAMPEDE has previously reported that radiotherapy (RT) to the prostate improved overall survival (OS) for patients with newly diagnosed prostate cancer with low metastatic burden, but not those with high-burden disease. In this final analysis, we report long-term findings on the primary outcome measure of OS and on the secondary outcome measures of symptomatic local events, RT toxicity events, and quality of life (QoL). METHODS AND FINDINGS: Patients were randomised at secondary care sites in the United Kingdom and Switzerland between January 2013 and September 2016, with 1:1 stratified allocation: 1,029 to standard of care (SOC) and 1,032 to SOC+RT. No masking of the treatment allocation was employed. A total of 1,939 had metastatic burden classifiable, with 42% low burden and 58% high burden, balanced by treatment allocation. Intention-to-treat (ITT) analyses used Cox regression and flexible parametric models (FPMs), adjusted for stratification factors age, nodal involvement, the World Health Organization (WHO) performance status, regular aspirin or nonsteroidal anti-inflammatory drug (NSAID) use, and planned docetaxel use. QoL in the first 2 years on trial was assessed using prospectively collected patient responses to QLQ-30 questionnaire. Patients were followed for a median of 61.3 months. Prostate RT improved OS in patients with low, but not high, metastatic burden (respectively: 202 deaths in SOC versus 156 in SOC+RT, hazard ratio (HR) = 0·64, 95% CI 0.52, 0.79, p < 0.001; 375 SOC versus 386 SOC+RT, HR = 1.11, 95% CI 0.96, 1.28, p = 0·164; interaction p < 0.001). No evidence of difference in time to symptomatic local events was found. There was no evidence of difference in Global QoL or QLQ-30 Summary Score. Long-term urinary toxicity of grade 3 or worse was reported for 10 SOC and 10 SOC+RT; long-term bowel toxicity of grade 3 or worse was reported for 15 and 11, respectively. CONCLUSIONS: Prostate RT improves OS, without detriment in QoL, in men with low-burden, newly diagnosed, metastatic prostate cancer, indicating that it should be recommended as a SOC. TRIAL REGISTRATION: ClinicalTrials.gov NCT00268476, ISRCTN.com ISRCTN78818544

Remyelination after chronic spinal cord injury is associated with proliferation of endogenous adult progenitor cells after systemic administration of guanosine

Axonal demyelination is a consistent pathological sequel to chronic brain and spinal cord injuries and disorders that slows or disrupts impulse conduction, causing further functional loss. Since oligodendroglial progenitors are present in the demyelinated areas, failure of remyelination may be due to lack of sufficient proliferation and differentiation of oligodendroglial progenitors. Guanosine stimulates proliferation and differentiation of many types of cells in vitro and exerts neuroprotective effects in the central nervous system (CNS). Five weeks after chronic traumatic spinal cord injury (SCI), when there is no ongoing recovery of function, intraperitoneal administration of guanosine daily for 2 weeks enhanced functional improvement correlated with the increase in myelination in the injured cord. Emphasis was placed on analysis of oligodendrocytes and NG2-positive (NG2+) cells, an endogenous cell population that may be involved in oligodendrocyte replacement. There was an increase in cell proliferation (measured by bromodeoxyuridine staining) that was attributable to an intensification in progenitor cells (NG2+ cells) associated with an increase in mature oligodendrocytes (determined by Rip+ staining). The numbers of astroglia increased at all test times after administration of guanosine whereas microglia only increased in the later stages (14 days). Injected guanosine and its breakdown product guanine accumulated in the spinal cords; there was more guanine than guanosine detected. We conclude that functional improvement and remyelination after systemic administration of guanosine is due to the effect of guanosine/guanine on the proliferation of adult progenitor cells and their maturation into myelin-forming cells. This raises the possibility that administration of guanosine may be useful in the treatment of spinal cord injury or demyelinating diseases such as multiple sclerosis where quiescent oligodendroglial progenitors exist in demyelinated plaques