Processing of pine (Pinus sylvestris) and birch (Betula pubescens) leaf material in a small river system in the northern Cairngorms, Scotland

International audienceProcessing rates, and macroinvertebrate colonisation, of pine needles and birch leaves were studied at eight sites on the river Nethy, a small river system in the Cairngorm region of north-eastern Scotland. Throughout this river system, processing rates were slow for pine (k values 0.0015-0.0034 day-1) and medium to fast for birch (k values 0.0085-0.0331 day-1). Plecopteran shredders dominated both pine and birch leaf packs during the early part of the experiment while chironomids were more important in the latter stages. It is suggested that the slow processing rate of pine needles could adversely affect the productivity of streams, particularly where needles provide the major allochthonous energy source and retentive features are limited. Forest managers should consider this when creating new pinewoods in treeless areas as it will take many years for the trees to reach a size at which they can effectively contribute retentive features, in the form of woody debris, to streams. Keywords: leaf processing, pine needles, shredders, Pinus sylvestris, Betula pubescens, Scotland

Variation in compulsory psychiatric inpatient admission in England:a cross-sectional, multilevel analysis

Background: Rates of compulsory admission have increased in England in recent decades, and this trend is accelerating. Studying variation in rates between people and places can help identify modifiable causes. Objectives: To quantify and model variances in the rate of compulsory admission in England at different spatial levels and to assess the extent to which this was explained by characteristics of people and places. Design: Cross-sectional analysis using multilevel statistical modelling. Setting: England, including 98% of Census lower layer super output areas (LSOAs), 95% of primary care trusts (PCTs), 93% of general practices and all 69 NHS providers of specialist mental health services. Participants: 1,287,730 patients. Main outcome measure: The study outcome was compulsory admission, defined as time spent in an inpatient mental illness bed subject to the Mental Health Act (2007) in 2010/11. We excluded patients detained under sections applying to emergency assessment only (including those in places of safety), guardianship or supervision of community treatment. The control group comprised all other users of specialist mental health services during the same period. Data sources: The Mental Health Minimum Data Set (MHMDS). Data on explanatory variables, characterising each of the spatial levels in the data set, were obtained from a wide range of sources, and were linked using MHMDS identifiers. Results: A total of 3.5% of patients had at least one compulsory admission in 2010/11. Of (unexplained) variance in the null model, 84.5% occurred between individuals. Statistically significant variance occurred between LSOAs [6.7%, 95% confidence interval (CI) 6.2% to 7.2%] and provider trusts (6.9%, 95% CI 4.3% to 9.5%). Variances at these higher levels remained statistically significant even after adjusting for a large number of explanatory variables, which together explained only 10.2% of variance in the study outcome. The number of provider trusts whose observed rate of compulsory admission differed from the model average to a statistically significant extent fell from 45 in the null model to 20 in the fully adjusted model. We found statistically significant associations between compulsory admission and age, gender, ethnicity, local area deprivation and ethnic density. There was a small but statistically significant association between (higher) bed occupancy and compulsory admission, but this was subsequently confounded by other covariates. Adjusting for PCT investment in mental health services did not improve model fit in the fully adjusted models. Conclusions: This was the largest study of compulsory admissions in England. While 85% of the variance in this outcome occurred between individuals, statistically significant variance (around 7% each) occurred between places (LSOAs) and provider trusts. This higher-level variance in compulsory admission remained largely unchanged even after adjusting for a large number of explanatory variables. We were constrained by data available to us, and therefore our results must be interpreted with caution. We were also unable to consider many hypotheses suggested by the service users, carers and professionals who we consulted. There is an imperative to develop and evaluate interventions to reduce compulsory admission rates. This requires further research to extend our understanding of the reasons why these rates remain so high. Funding: The National Institute for Health Research Health Services and Delivery Research programme

Spontaneous DC Current Generation in a Resistively Shunted Semiconductor Superlattice Driven by a TeraHertz Field

We study a resistively shunted semiconductor superlattice subject to a high-frequency electric field. Using a balance equation approach that incorporates the influence of the electric circuit, we determine numerically a range of amplitude and frequency of the ac field for which a dc bias and current are generated spontaneously and show that this region is likely accessible to current experiments. Our simulations reveal that the Bloch frequency corresponding to the spontaneous dc bias is approximately an integer multiple of the ac field frequency.Comment: 8 pages, Revtex, 3 Postscript figure

S1×S2S^1 \times S^2 wormholes and topological charge

I investigate solutions to the Euclidean Einstein-matter field equations with topology $S^1 \times S^2 \times R$ in a theory with a massless periodic scalar field and electromagnetism. These solutions carry winding number of the periodic scalar as well as magnetic flux. They induce violations of a quasi-topological conservation law which conserves the product of magnetic flux and winding number on the background spacetime. I extend these solutions to a model with stable loops of superconducting cosmic string, and interpret them as contributing to the decay of such loops.Comment: 18 pages (includes 6 figs.), harvmac and epsf, CU-TP-62

The impact of assisted reproductive technology treatments on maternal and offspring outcomes in singleton pregnancies: A review of systematic reviews

Objectives: Assisted reproductive technology (ART) treatments are commonly used to aid conception in subfertile couples. We aimed to evaluate the risks of adverse maternal and offspring outcomes in singleton pregnancy conceived with different ART treatments and techniques. / Evidence review: We searched MEDLINE, EMBASE, CENTRAL and HTA until December 2020 for all systematic reviews evaluating adverse outcomes in pregnancies conceived with various ART techniques, autologous or donor gametes, and embryo development stages. We assessed review quality using the AMSTAR2 tool risk (RR) or odds ratio (OR) with 95% confidence intervals (CI) from the top quality reviews for each of the outcomes of interest across the identified ART treatments and population subgroups. / Results: We included 24 systematic reviews, most reported on observational studies. Compared to spontaneous conception, ART pregnancies had a higher risk of placenta previa (PP) (RR 3.71, 95%CI 2.67-5.16), antepartum haemorrhage (APH) (RR 2.11, 95%CI 1.86-2.38), preterm birth (PTB) (RR 1.71, 95%CI 1.59-1.83), very preterm birth (VPTB) (RR 2.12, 95%CI 1.73-2.59), small for gestational age (SGA) (RR 1.35, 95%CI 1.20-1.52), low birthweight (LBW) (RR 1.61, 95%CI 1.49-1.75) and very low birthweight (VLBW) (RR 2.12, 95%CI 1.84-2.43). Frozen vs fresh embryo transfer was associated with a lower risk for PTB (RR 0.90, 95%CI 0.84-0.97), SGA (RR 0.61, 95%CI 0.56-0.67), LBW (RR 0.72, 95%CI 0.67-0.77) and VLBW (RR 0.76, 95%CI 0.69–0.82). Embryo transfer at blastocyst vs cleavage showed higher risk for PTB (RR 1.10, 95%CI 1.01-1.20) and large for gestational age (LGA) (RR 1.12, 95%CI 1.03-1.21) with lower risk for SGA (RR 0.84, 95%CI 0.76-0.92). Using donor vs autologous oocytes increased the odds of PTB (OR 1.57, 95%CI 1.33-1.86), LBW (OR 1.94, 95%CI 1.10-3.41) and VLBW (OR 1.37, 95%CI 1.22–1.54) as well as maternal complications (postpartum haemorrhage OR 1.96, 95% CI 1.20-3.20, gestational diabetes OR 1.27 95%CI 1.03-1.56, hypertensive disorders of pregnancy OR 2.63, 95%CI 2.17-3.18, and caesarean section OR 2.28, 95%CI 2.14-2.42). / Conclusions: ART treatments are associated with increased risks of adverse maternal and offspring outcomes, especially with donor oocytes. The characteristics of ART treatment should be incorporated into prenatal care planning to mitigate those risks

Theory of Coherent Time-dependent Transport in One-dimensional Multiband Semiconductor Superlattices

We present an analytical study of one-dimensional semiconductor superlattices in external electric fields, which may be time-dependent. A number of general results for the (quasi)energies and eigenstates are derived. An equation of motion for the density matrix is obtained for a two-band model, and the properties of the solutions are analyzed. An expression for the current is obtained. Finally, Zener-tunneling in a two-band tight-binding model is considered. The present work gives the background and an extension of the theoretical framework underlying our recent Letter [J. Rotvig {\it et al.}, Phys. Rev. Lett. {\bf 74}, 1831 (1995)], where a set of numerical simulations were presented.Comment: 15 pages, Revtex 3.0, uses epsf, 2 ps figures attache

Naturalistic rapid deceleration data: Drivers aged 75 years and older.

The data presented in this article are related to the research manuscript "Predictors of older drivers' involvement in rapid deceleration events", which investigates potential predictors of older drivers' involvement in rapid deceleration events including measures of vision, cognitive function and driving confidence (A. Chevalier et al., 2016) [1]. In naturalistic driving studies such as this, when sample size is not large enough to allow crashes to be used to investigate driver safety, rapid deceleration events may be used as a surrogate safety measure. Naturalistic driving data were collected for up to 52 weeks from 182 volunteer drivers aged 75-94 years (median 80 years, 52% male) living in the suburban outskirts of Sydney. Driving data were collected using an in-vehicle monitoring device. Accelerometer data were recorded 32 times per second and Global Positioning System (GPS) data each second. To measure rapid deceleration behavior, rapid deceleration events (RDEs) were defined as having at least one data point at or above the deceleration threshold of 750 milli-g (7.35 m/s2). All events were constrained to a maximum 5 s duration. The dataset provided with this article contains 473 events, with a row per RDE. This article also contains information about data processing, treatment and quality control. The methods and data presented here may assist with planning and analysis of future studies into rapid deceleration behaviour using in-vehicle monitoring

Time Periodic Behavior of Multiband Superlattices in Static Electric Fields

We use an analytic perturbation expansion for the two-band system of tight binding electrons to discuss Bloch oscillations and Zener tunneling within this model. We make comparison with recent numerical results and predict analytically the frequency of radiation expected from Zener tunneling, including its disappearance, as a function of the system parameters.Comment: 12 pages, no figure include

Non-perturbative electron dynamics in crossed fields

Intense AC electric fields on semiconductor structures have been studied in photon-assisted tunneling experiments with magnetic field applied either parallel (B_par) or perpendicular (B_per) to the interfaces. We examine here the electron dynamics in a double quantum well when intense AC electric fields F, and tilted magnetic fields are applied simultaneously. The problem is treated non-perturbatively by a time-dependent Hamiltonian in the effective mass approximation, and using a Floquet-Fourier formalism. For B_par=0, the quasi-energy spectra show two types of crossings: those related to different Landau levels, and those associated to dynamic localization (DL), where the electron is confined to one of the wells, despite the non-negligible tunneling between wells. B_par couples parallel and in-plane motions producing anti-crossings in the spectrum. However, since our approach is non-perturbative, we are able to explore the entire frequency range. For high frequencies, we reproduce the well known results of perfect DL given by zeroes of a Bessel function. We find also that the system exhibits DL at the same values of the field F, even as B_par non-zero, suggesting a hidden dynamical symmetry in the system which we identify with different parity operations. The return times for the electron at various values of field exhibit interesting and complex behavior which is also studied in detail. We find that smaller frequencies shifts the DL points to lower field F, and more importantly, yields poorer localization by the field. We analyze the explicit time evolution of the system, monitoring the elapsed time to return to a given well for each Landau level, and find non-monotonic behavior for decreasing frequencies.Comment: REVTEX4 + 11 eps figs, submitted to Phys. Rev.

Cosmological and Wormhole Solutions in Low-Energy Effective String Theory

We derive and study a class of cosmological and wormhole solutions of low-energy effective string field theory. We consider a general four-dimensional string effective action where moduli of the compactified manifold and the electromagnetic field are present. The cosmological solutions of the two-dimensional effective theory obtained by dimensional reduction of the former are discussed. In particular we demonstrate that the two-dimensional theory possesses a scale-factor duality invariance. Euclidean four-dimensional instantons describing the nucleation of the baby universes are found and the probability amplitude for the nucleation process is given.Comment: 18 pages, Plain-Tex Report No: INFNCA-TH-94-11, SISSA 75/94/