Mesoscopic Stern-Gerlach device to polarize spin currents

Spin preparation and spin detection are fundamental problems in spintronics and in several solid state proposals for quantum information processing. Here we propose the mesoscopic equivalent of an optical polarizing beam splitter (PBS). This interferometric device uses non-dispersive phases (Aharonov-Bohm and Rashba) in order to separate spin up and spin down carriers into distinct outputs and thus it is analogous to a Stern-Gerlach apparatus. It can be used both as a spin preparation device and as a spin measuring device by converting spin into charge (orbital) degrees of freedom. An important feature of the proposed spin polarizer is that no ferromagnetic contacts are used.Comment: Updated to the published versio

Consumptive Use of Water by Major Crops in the Southwestern United States

This publication identifies and clarifies aspects of water use by the most common field crops in the Southwestern United States. Estimates of consumptive use in the Salt River Valley of Arizona, as measured by soil moisture depletion, are reported. A method is described for using the reported data to develop consumptive use estimates for other irrigated areas. This USDA Conservation Research Report updates an earlier bulletin, "Consumptive Use of Water by Crops in Arizona," by Erie et al., including both additional crops and years of data

Applying a new concept of embedding qualitative research: An example from a quantitative study of carers of people in later stage dementia

BACKGROUND: Qualitative methods are increasingly included in larger studies to provide a richer understanding of people's experience. This paper explores the potential of using a novel approach to embedded qualitative design as part of an observational study examining the effectiveness of home support for people in later stage dementia in England. The method involved collecting and analysing unsolicited conversational comments made by participants as they completed standardised measures. An evaluation of the method is presented using the voices of participants to illustrate its potential. METHODS: The conversations of 17 carers recruited to an observational study were audio recorded to gather commentary made while completing a structured interview. Data were interrogated using thematic analysis to investigate the feasibility of conducting an embedded qualitative study, the potential richness of the material and participants' reactions to formal questioning and participating in research. RESULTS: The findings revealed that qualitative data were available from this approach. Analysis generated three themes from carers: conflicting carer emotions; the importance of maintaining normality and agency within day-to-day life; and tensions between these desires and making use of formal services. Important issues for carers were revealed establishing the benefit of using the method. The advantages of exploiting unsolicited conversation included enhancing understanding of people's lived experience, reducing participant burden in research and easing the process of data collection. In addition, it provided an opportunity to evaluate individuals' experience of the research process. CONCLUSIONS: The findings demonstrate how unsolicited comments during structured interviews may appear incidental but can reveal important aspects of living with dementia. The method also emphasised methodological challenges for research in dementia, including the influence and impact of the research context. Further research is required to evaluate the method with other groups including people with dementia themselves

Evaluation of absorbent materials for use as ad hoc dry decontaminants during mass casualty incidents as part of the UK’s Initial Operational Response (IOR)

Copyright: © 2017 Kassouf et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.The UK's Initial Operational Response (IOR) is a revised process for the medical management of mass casualties potentially contaminated with hazardous materials. A critical element of the IOR is the introduction of immediate, on-scene disrobing and decontamination of casualties to limit the adverse health effects of exposure. Ad hoc cleansing of the skin with dry absorbent materials has previously been identified as a potential means of facilitating emergency decontamination. The purpose of this study was to evaluate the in vitro oil and water absorbency of a range of materials commonly found in the domestic and clinical environments and to determine the effectiveness of a small, but representative selection of such materials in skin decontamination, using an established ex vivo model. Five contaminants were used in the study: methyl salicylate, parathion, diethyl malonate, phorate and potassium cyanide. In vitro measurements of water and oil absorbency did not correlate with ex vivo measurements of skin decontamination. When measured ex vivo, dry decontamination was consistently more effective than a standard wet decontamination method ("rinse-wipe-rinse") for removing liquid contaminants. However, dry decontamination was ineffective against particulate contamination. Collectively, these data confirm that absorbent materials such as wound dressings and tissue paper provide an effective, generic capability for emergency removal of liquid contaminants from the skin surface, but that wet decontamination should be used for non-liquid contaminants.Peer reviewedFinal Published versio

Sleep discrepancy and cognitive function in community-dwelling older adults

This was the first study to use cluster analysis to characterise sleep discrepancy (the discordance between self-reported and objective sleep) across multiple sleep parameters, in community-dwelling older adults. For sleep efficiency, negative discrepancy (the tendency to self-report worse sleep than objectively-measured) was associated with poorer memory, independent of insomnia severity, depressive symptoms and objective sleep. This suggests a unique role for sleep discrepancy as a possible risk factor for future cognitive decline, and warrants the need for further research

Nurse-Led Medicines' Monitoring for Patients with Dementia in Care Homes: A Pragmatic Cohort Stepped Wedge Cluster Randomised Trial

People with dementia are susceptible to adverse drug reactions (ADRs). However, they are not always closely monitored for potential problems relating to their medicines: structured nurse-led ADR Profiles have the potential to address this care gap. We aimed to assess the number and nature of clinical problems identified and addressed and changes in prescribing following introduction of nurse-led medicines' monitoring.Pragmatic cohort stepped-wedge cluster Randomised Controlled Trial (RCT) of structured nurse-led medicines' monitoring versus usual care.Five UK private sector care homes.41 service users, taking at least one antipsychotic, antidepressant or anti-epileptic medicine.Nurses completed the West Wales ADR (WWADR) Profile for Mental Health Medicines with each participant according to trial step.Problems addressed and changes in medicines prescribed.Information was collected from participants' notes before randomisation and after each of five monthly trial steps. The impact of the Profile on problems found, actions taken and reduction in mental health medicines was explored in multivariate analyses, accounting for data collection step and site.Five of 10 sites and 43 of 49 service users approached participated. Profile administration increased the number of problems addressed from a mean of 6.02 [SD 2.92] to 9.86 [4.48], effect size 3.84, 95% CI 2.57-4.11, P <0.001. For example, pain was more likely to be treated (adjusted Odds Ratio [aOR] 3.84, 1.78-8.30), and more patients attended dentists and opticians (aOR 52.76 [11.80-235.90] and 5.12 [1.45-18.03] respectively). Profile use was associated with reduction in mental health medicines (aOR 4.45, 1.15-17.22).The WWADR Profile for Mental Health Medicines can improve the quality and safety of care, and warrants further investigation as a strategy to mitigate the known adverse effects of prescribed medicines.ISRCTN 48133332

Dizziness and imbalance and their association with general and mental health in a community-based cross-sectional study of middle-aged individuals: the Busselton healthy ageing study

BACKGROUND: Dizziness and imbalance are common symptoms among patients visiting healthcare providers. Current knowledge about their prevalence, impact on daily life, and associated factors is primarily based on selected samples from individuals seeking medical help, particularly older individuals. This study aimed to estimate the prevalence, symptoms, and impact of dizziness or imbalance symptoms, and to assess the association between these symptoms and their characteristics with demographic, general health, and mental health factors in middle-aged men and women from a representative, general population sample. METHODS: Cross-sectional data were collected from participants aged 45 to 70 years in the Busselton Healthy Ageing Study (BHAS), recruited in the City of Busselton, Western Australia. The data included physical tests and health-related questionnaires covering demographics, medical history, general and mental health, including any dizziness and imbalance symptoms and their impact on daily life. Estimates were made of the prevalence, patterns, and impact of dizziness and imbalance symptoms. Logistic regression was employed to calculate the association between demographic, mental and general health (independent variables) and the presence of dizziness or imbalance symptoms (dependent variable). Adjustments were made for sex and age as confounding factors. RESULTS: Of the 5086 participants, 1216 (23.9%) reported imbalance or dizziness, with light-headedness the most common type (64.3%; 782 of 1216). For nearly half (565; 46.5%) the imbalance or dizziness occasionally effected daily life, while for some, the impact was frequent (n = 50, 4.1%) or constant (n = 15, 1.2%). Being female (adjusted OR 2.05, 95%CI 1.79-2.34) and older in age (in years; adjusted OR 1.02, 95%CI 1.00-1.03), having a history of general health issues, and experiencing mental health problems or mental health symptoms were significantly associated with dizziness or imbalance symptoms. CONCLUSIONS: Dizziness or imbalance are common symptoms among individuals aged 45 to 70 years and are associated with older age, being female, and poorer general and mental health. Given that approximately half of those affected reported occasional effects on daily life, with a few reporting frequent or constant effects, the outcomes of the study could help to raise awareness among healthcare providers about the prevalence, symptoms, and associated conditions

Sleep discrepancy and brain glucose metabolism in community-dwelling older adults

Sleep discrepancy (negative discrepancy reflects worse self-reported sleep than objective measures, such as actigraphy, and positive discrepancy the opposite) has been linked to adverse health outcomes. This study is first to investigate the relationship between sleep discrepancy and brain glucose metabolism (assessed globally and regionally via positron emission tomography), and to evaluate the contribution of insomnia severity and depressive symptoms to any associations. Using data from cognitively unimpaired community-dwelling older adults (N = 68), cluster analysis was used to characterise sleep discrepancy (for total sleep time (TST), wake after sleep onset (WASO), and sleep efficiency (SE)), and logistic regression was used to explore sleep discrepancy\u27s associations with brain glucose metabolism, while controlling for insomnia severity and depressive symptoms. Lower glucose metabolism across multiple brain regions was associated with negative discrepancy for WASO and SE, and positive discrepancy for WASO only (large effect sizes; β ≥ 0.5). Higher glucose metabolism in the superior parietal and posterior cingulate regions was associated with negative discrepancy for TST (large effect sizes; β ≥ 0.5). These associations remained when controlling for insomnia severity and depressive symptoms, suggesting a unique role of sleep discrepancy as a potential early behavioural marker of brain health

Suboptimal self-reported sleep efficiency and duration are associated with faster accumulation of brain amyloid beta in cognitively unimpaired older adults

INTRODUCTION: This study investigated whether self-reported sleep quality is associated with brain amyloid beta (AB) accumulation. METHODS: Linear mixed effect model analyses were conducted for 189 cognitively unimpaired (CU) older adults (mean ± standard deviation 74.0 ± 6.2; 53.2% female), with baseline self-reported sleep data, and positron emission tomography-determined brain AB measured over a minimum of three time points (range 33.3–72.7 months). Analyses included random slopes and intercepts, interaction for apolipoprotein E (APOE) 4 allele status, and time, adjusting for sex and baseline age. RESULTS: Sleep duration \u3c 6 hours, in APOE 4 carriers, and sleep efficiency \u3c 65%, in the whole sample and APOE 4 non-carriers, is associated with faster accumulation of brain AB. DISCUSSION: These findings suggest a role for self-reported suboptimal sleep efficiency and duration in the accumulation of Alzheimer\u27s disease (AD) neuropathology in CU individuals. Additionally, poor sleep efficiency represents a potential route via which individuals at lower genetic risk may progress to preclinical AD. Highlights: In cognitively unimpaired older adults self-report sleep is associated with brain amyloid beta (AB) accumulation. Across sleep characteristics, this relationship differs by apolipoprotein E (APOE) genotype. Sleep duration \u3c 6 hours is associated with faster brain AB accumulation in APOE 4 carriers. Sleep efficiency \u3c 65% is associated with faster brain AB accumulation in APOE 4 non-carriers. Personalized sleep interventions should be studied for potential to slow AB accumulation

Adaptation to Life in the High Andes: Nocturnal Oxyhemoglobin Saturation in Early Development

STUDY OBJECTIVES: Physiological adaptation to high altitude hypoxia may be impaired in Andeans with significant European ancestry. The respiratory 'burden' of sleep may challenge adaptation, leading to relative nocturnal hypoxia. Developmental aspects of sleep-related breathing in high-altitude native children have not previously been reported. We aimed to determine the influence of development on diurnal-nocturnal oxyhemoglobin differences in children living at high altitude. METHODS: This was a cross-sectional, observational study. Seventy-five healthy Bolivian children aged 6 mo to 17 y, native to low altitude (500 m), moderate high altitude (2,500 m), and high altitude (3700 m) were recruited. ABSTRACT: Daytime resting pulse oximetry was compared to overnight recordings using Masimo radical oximeters. Genetic ancestry was determined from DNA samples. RESULTS: Children had mixed European/Amerindian ancestry, with no significant differences between altitudes. Sixty-two participants had > 5 h of nocturnal, artifact-free data. As predicted, diurnal mean oxyhemoglobin saturation decreased across altitudes (infants and children, both P < 0.001), with lowest diurnal values at high altitude in infants. At high altitude, there was a greater drop in nocturnal mean oxyhemoglobin saturation (infants, P < 0.001; children, P = 0.039) and an increase in variability (all P ≤ 0.001) compared to low altitude. Importantly, diurnal to nocturnal altitude differences diminished (P = 0.036), from infancy to childhood, with no further change during adolescence. CONCLUSIONS: Physiological adaptation to high-altitude living in native Andeans is unlikely to compensate for the significant differences we observed between diurnal and nocturnal oxyhemoglobin saturation, most marked in infancy. This vulnerability to sleep-related hypoxia in early childhood has potential lifespan implications. Future studies should characterize the sleep- related respiratory physiology underpinning our observations