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We present a broad study of linear, clustered, noble gas puffs irradiated with the frequency doubled (527 nm) Titan laser at Lawrence Livermore National Laboratory. Pure Ar, Kr, and Xe clustered gas puffs, as well as two mixed-gas puffs consisting of KrAr and XeKrAr gases, make up the targets. Characterization experiments to determine gas-puff density show that varying the experimental parameter gas-delay timing (the delay between gas puff initialization and laser-gas-puff interaction) provides a simple control over the gas-puff density. X-ray emission (>1.4 keV) is studied as a function of gas composition, density, and delay timing. Xe gas puffs produce the strongest peak radiation in the several keV spectral region. The emitted radiation was found to be anisotropic, with smaller X-ray flux observed in the direction perpendicular to both laser beam propagation and polarization directions. The degree of anisotropy is independent of gas target type but increases with photon energy. X-ray spectroscopic measurements estimate plasma parameters and highlight their difference with previous studies. Electron beams with energy in excess of 72 keV are present in the noble gas-puff plasmas and results indicate that Ar plays a key role in their production. A drastic increase in harder X-ray emissions (X-ray flash effect) and multi-MeV electron-beam generation from Xe gas-puff plasma occurred when the laser beam was focused on the front edge of the linear gas puff.
Cardiac surgery-associated acute kidney injury is common. In order to improve our understanding of acute kidney injury, we formed the multi-centre Neonatal and Pediatric Heart and Renal Outcomes Network. Our main goals are to describe neonatal kidney injury epidemiology, evaluate variability in diagnosis and management, identify risk factors, investigate the impact of fluid overload, and explore associations with outcomes.
The Neonatal and Pediatric Heart and Renal Outcomes Network collaborative includes representatives from paediatric cardiac critical care, cardiology, nephrology, and cardiac surgery. The collaborative sites and infrastructure are part of the Pediatric Cardiac Critical Care Consortium. An acute kidney injury module was developed and merged into the existing infrastructure. A total of twenty-two participating centres provided data on 100–150 consecutive neonates who underwent cardiac surgery within the first 30 post-natal days. Additional acute kidney injury variables were abstracted by chart review and merged with the corresponding record in the quality improvement database. Exclusion criteria included >1 operation in the 7-day study period, pre-operative renal replacement therapy, pre-operative serum creatinine >1.5 mg/dl, and need for extracorporeal support in the operating room or within 24 hours after the index operation.
A total of 2240 neonatal patients were enrolled across 22 centres. The incidence of acute kidney injury was 54% (stage 1 = 31%, stage 2 = 13%, and stage 3 = 9%).
Neonatal and Pediatric Heart and Renal Outcomes Network represents the largest multi-centre study of neonatal kidney injury. This new network will enhance our understanding of kidney injury and its complications.
A procedure using tube excited energy dispersive x-ray fluorescence analysis with interelement corrections has been developed for multielement analysis of major and trace elements and ash content of coal, coke, and fly ash. The procedure uses pressed pellets and an exponential correction for interelement effects. The average deviations ranged from about 0.0003% for V at an average concentration of about .003% to 0.1% for S at an average concentration of 4%. About 25 elements were measured and 100 second minimum detectable concentrations ranged from about one part per million for elements near arsenic to about one tenth of one percent for sodium.
A rapid multielement analysis procedure for cement and ceramic type materials has been developed which uses pelletized powders and an exponential correction to the observed x-ray intensities. Only the more significant interactions are considered in an iterative process requiring a minimum of standards. The interaction coefficients are determined by a nonlinear multiple least squares fit of the standards. Average deviations obtained for the analysis of light elements in cement ranged from a low of 0.006% for K2O to a high of 0.13% absolute for SiO2.
Major depressive disorder (MDD) is a highly heterogeneous condition in terms of symptom presentation and, likely, underlying pathophysiology. Accordingly, it is possible that only certain individuals with MDD are well-suited to antidepressants. A potentially fruitful approach to parsing this heterogeneity is to focus on promising endophenotypes of depression, such as neuroticism, anhedonia, and cognitive control deficits.
Within an 8-week multisite trial of sertraline v. placebo for depressed adults (n = 216), we examined whether the combination of machine learning with a Personalized Advantage Index (PAI) can generate individualized treatment recommendations on the basis of endophenotype profiles coupled with clinical and demographic characteristics.
Five pre-treatment variables moderated treatment response. Higher depression severity and neuroticism, older age, less impairment in cognitive control, and being employed were each associated with better outcomes to sertraline than placebo. Across 1000 iterations of a 10-fold cross-validation, the PAI model predicted that 31% of the sample would exhibit a clinically meaningful advantage [post-treatment Hamilton Rating Scale for Depression (HRSD) difference ⩾3] with sertraline relative to placebo. Although there were no overall outcome differences between treatment groups (d = 0.15), those identified as optimally suited to sertraline at pre-treatment had better week 8 HRSD scores if randomized to sertraline (10.7) than placebo (14.7) (d = 0.58).
A subset of MDD patients optimally suited to sertraline can be identified on the basis of pre-treatment characteristics. This model must be tested prospectively before it can be used to inform treatment selection. However, findings demonstrate the potential to improve individual outcomes through algorithm-guided treatment recommendations.
The depletion of neutral helium atoms has been studied in an unmagnetised spherical plasma created by DC discharge in a multidipole confinement field. Knowing the neutral density profile is critical to predicting the equilibrium flow of such plasmas. A model of the emissivity due to electron-impact excitation of neutral atoms in the plasma has been derived and used to fit radiance measurements of several neutral transitions to extract the radial profile of neutral density for plasmas of varying temperature and density. We report a depletion of the core neutral density varying between negligible levels to 80 % of the edge neutral density depending on the input power and fuelling. The corresponding ionisation fraction varies between 30–80 % in the plasma core. A simple neutral diffusion model is sufficient to describe the shape of neutral density profile implied by the radiance measurements. We have used the measurements to include a drag force due to neutral charge-exchange collisions in simulations of driven plasma flow. The simulation predicts a better fit to Mach probe flow measurements when this neutral drag is accounted for. This work shows that accounting for a realistic neutral profile is important to predict the plasma flow geometry and its magnetohydrodynamics (MHD) stability.
To understand increasing rates of hepatitis C virus (HCV) infection in Tennessee, we conducted testing, risk factor analysis and a nested case–control study among persons who use drugs. During June–October 2016, HCV testing with risk factor assessment was conducted in sexually transmitted disease clinics, family planning clinics and an addiction treatment facility in eastern Tennessee; data were analysed by using multivariable logistic regression. A nested case–control study was conducted to assess drug-using risks and behaviours among persons who reported intranasal or injection drug use (IDU). Of 4753 persons tested, 397 (8.4%) were HCV-antibody positive. HCV infection was significantly associated with a history of both intranasal and IDU (adjusted odds ratio (aOR) 35.4, 95% confidence interval (CI) 24.1–51.9), IDU alone (aOR 52.7, CI 25.3–109.9), intranasal drug use alone (aOR 2.6, CI 1.8–3.9) and incarceration (aOR 2.7, CI 2.0–3.8). By 4 October 2016, 574 persons with a reported history of drug use; 63 (11%) were interviewed further. Of 31 persons who used both intranasal and injection drugs, 26 (84%) reported previous intranasal drug use, occurring 1–18 years (median 5.5 years) before their first IDU. Our findings provide evidence that reported IDU, intranasal drug use and incarceration are independent indicators of risk for past or present HCV infection in the study population.
The healthcare environment is recognized as a source for healthcare-acquired infection. Because cleaning practices are often erratic and always intermittent, we hypothesize that continuously antimicrobial surfaces offer superior control of surface bioburden.
To evaluate the impact of a photocatalytic antimicrobial coating at near-patient, high-touch sites in a hospital ward.
The study took place in 2 acute-care wards in a large acute-care hospital.
A titanium dioxide-based photocatalytic coating was sprayed onto 6 surfaces in a 4-bed bay in a ward and compared under normal illumination against the same surfaces in an untreated ward: right and left bed rails, bed control, bedside locker, overbed table, and bed footboard. Using standardized methods, the overall microbial burden and presence of an indicator pathogen (Staphylococcus aureus) were assessed biweekly for 12 weeks.
Treated surfaces demonstrated significantly lower microbial burden than control sites, and the difference increased between treated and untreated surfaces during the study. Hygiene failures (>2.5 colony-forming units [CFU]/cm2) increased 2.6% per day for control surfaces (odds ratio [OR], 1.026; 95% confidence interval [CI], 1.009–1.043; P=.003) but declined 2.5% per day for treated surfaces (OR, 0.95; 95% CI, 0.925–0.977; P<.001). We detected no significant difference between coated and control surfaces regarding S. aureus contamination.
Photocatalytic coatings reduced the bioburden of high-risk surfaces in the healthcare environment. Treated surfaces became steadily cleaner, while untreated surfaces accumulated bioburden. This evaluation encourages a larger-scale investigation to ascertain whether the observed environmental amelioration has an effect on healthcare-acquired infection.
Unprotected n-3 PUFA supplements fed to ruminants are subject to lipolysis and biohydrogenation in the rumen (Wachira et al. 1998). Improving the n-3 PUFA content of ruminant products therefore requires some form of protection of dietary lipid from microbial activity in the rumen. The in-vitro incubation of PUFA sources offers the opportunity of rapidly determining the level of protection offered against ruminal biohydrogenation. The objectives of the current experiment were therefore to determine the biohydrogenation of a number of sources containing a-linolenic acid using the in-vitro gas production technique.
To determine the patterns and predictors of treatment response trajectories for veterans with post-traumatic stress disorder (PTSD).
Conditional latent growth mixture modelling was used to identify classes and predictors of class membership. In total, 2686 veterans treated for PTSD between 2002 and 2015 across 14 hospitals in Australia completed the PTSD Checklist at intake, discharge, and 3 and 9 months follow-up. Predictor variables included co-morbid mental health problems, relationship functioning, employment and compensation status.
Five distinct classes were found: those with the most severe PTSD at intake separated into a relatively large class (32.5%) with small change, and a small class (3%) with a large change. Those with slightly less severe PTSD separated into one class comprising 49.9% of the total sample with large change effects, and a second class comprising 7.9% with extremely large treatment effects. The final class (6.7%) with least severe PTSD at intake also showed a large treatment effect. Of the multiple predictor variables, depression and guilt were the only two found to predict differences in response trajectories.
These findings highlight the importance of assessing guilt and depression prior to treatment for PTSD, and for severe cases with co-morbid guilt and depression, considering an approach to trauma-focused therapy that specifically targets guilt and depression-related cognitions.
Treatment of medical patients with the inflammatory cytokine, interferon-α (IFN-α), is frequently associated with the development of clinical depressive symptomatology. Several important biological correlates of the effect of IFN-α on mood have been described, but the neuropsychological changes associated with IFN-α treatment are largely unexplored. The aim of the present preliminary study was to assess the effect of IFN-α on measures of emotional processing.
We measured changes in emotional processing over 6–8 weeks in 17 patients receiving IFN-α as part of their treatment for hepatitis C virus infection. Emotional processing tasks included those which have previously been shown to be sensitive to the effects of depression and antidepressant treatment, namely facial expression recognition, emotional categorisation and the dot probe attentional task.
Following IFN-α, patients were more accurate at detecting facial expressions of disgust; they also showed diminished attentional vigilance to happy faces. IFN-α produced the expected increases in scores on depression rating scales, but there was no correlation between these scores and the changes in emotional processing.
Our preliminary findings suggest that IFN-α treatment produces negative biases in emotional processing, and this effect is not simply a consequence of depression. It is possible that increased recognition of disgust may represent a neuropsychological marker of depressive disorders related to inflammation.
This paper describes the use of a neutron probe to measure detailed stratigraphy in ice and snow. The Wallingford neutron probe, developed for measurement of soil moisture, consists of an annular radioactive source of fast neutrons around the centre of a cylindrical detector for slow (thermal) neutrons. In snow and ice, the fast neutrons lose energy by scattering from hydrogen atoms, and the number of slow neutrons arriving at the detector (the count rate) is related to the density of the medium. Calibration equations for count rate as a function of snow density and borehole diameter have been derived. Snow-density profiles from boreholes obtained using the probe show that, despite the smoothing produced by the neutron-scattering process, annual variations in density can be resolved. The potential contribution of the neutron probe to improvements in mass-balance monitoring is discussed.
Annual proglacial solute fluxes and chemical weathering rates at a polythermal high-Arctic glacier are presented. Bulk meltwater chemistry and discharge were monitored continuously at gauging stations located at the eastern and western margins of the glacier terminus and at “the Outlet”, 2.5 km downstream where meltwaters discharge into the fjord. Fluxes of non-snowpack HCO3−, SO42−, Ca2+ and Mg2+ increase by 30–47% between the glacier terminus and the Outlet, indicating that meltwaters are able to access and chemically weather efflorescent sulphates, carbonates and sulphides in the proglacial zone. Smaller increases in the fluxes of non-snowpack-derived Na+, K+ and Si indicate that proglacial chemical weathering of silicates is less significant. En3hanced solute fluxes in the proglacial zone are mainly due to the chemical weathering of active-layer sediments. The PCO2 of active-layer ground-waters is above atmospheric pressure. This implies that solute acquisition in the active layer involves no drawdown of CO2. The annual proglacial chemical weathering rate in 1999 is calculated to be 2600 meqΣ+ m−2. This exceeds the chemical weathering rate for the glaciated part of the catchment (790 meqΣ+ m−2) by a factor of 3.3. Hence, the proglacial zone at Finster-walderbreen is identified as an area of high geochemical reactivity and a source of CO2.
The Square Kilometre Array will be an amazing instrument for pulsar astronomy. While the full SKA will be sensitive enough to detect all pulsars in the Galaxy visible from Earth, already with SKA1, pulsar searches will discover enough pulsars to increase the currently known population by a factor of four, no doubt including a range of amazing unknown sources. Real time processing is needed to deal with the 60 PB of pulsar search data collected per day, using a signal processing pipeline required to perform more than 10 POps. Here we present the suggested design of the pulsar search engine for the SKA and discuss challenges and solutions to the pulsar search venture.
The care received by people presenting to hospital following self-harm varies and it is unclear how different types of treatment affect risk of further self-harm.
Observational cohort data from the Manchester Self-Harm Project, UK, included 16 456 individuals presenting to an Emergency Department with self-harm between 2003 and 2011. Individuals were followed up for 12 months. We also used data from a smaller cohort of individuals presenting to 31 hospitals in England during a 3-month period in 2010/2011, followed up for 6 months. Propensity score (PS) methods were used to address observed confounding. Missing data were imputed using multiple imputation.
Following PS stratification, those who received a psychosocial assessment had a lower risk of repeat hospital attendance for self-harm than those who were not assessed [RR 0.87, 95% confidence interval (CI) 0.80–0.95]. The risk was reduced most among people less likely to be assessed. Following PS matching, we found no associations between risks of repeat self-harm and admission to a medical bed, referral to outpatient psychiatry or admission to a psychiatric bed. We did not find a relationship between psychosocial assessment and repeat self-harm in the 31 centre cohort.
This study shows the potential value of using novel statistical techniques in large mental health datasets to estimate treatment effects. We found that specialist psychosocial assessment may reduce the risk of repeat self-harm. This type of routine care should be provided for all individuals who present to hospital after self-harm, regardless of perceived risk.
A considerable body of evidence suggests that early caregiving may affect the short-term functioning and longer term development of the hypothalamic–pituitary–adrenocortical axis. Despite this, most research to date has been cross-sectional in nature or restricted to relatively short-term longitudinal follow-ups. More important, there is a paucity of research on the role of caregiving in low- and middle-income countries, where the protective effects of high-quality care in buffering the child's developing stress regulation systems may be crucial. In this paper, we report findings from a longitudinal study (N = 232) conducted in an impoverished periurban settlement in Cape Town, South Africa. We measured caregiving sensitivity and security of attachment in infancy and followed children up at age 13 years, when we conducted assessments of hypothalamus–pituitary–adrenocortical axis reactivity, as indexed by salivary cortisol during the Trier Social Stress Test. The findings indicated that insecure attachment was predictive of reduced cortisol responses to social stress, particularly in boys, and that attachment status moderated the impact of contextual adversity on stress responses: secure children in highly adverse circumstances did not show the blunted cortisol response shown by their insecure counterparts. Some evidence was found that sensitivity of care in infancy was also associated with cortisol reactivity, but in this case, insensitivity was associated with heightened cortisol reactivity, and only for girls. The discussion focuses on the potentially important role of caregiving in the long-term calibration of the stress system and the need to better understand the social and biological mechanisms shaping the stress response across development in low- and middle-income countries.
The amount of Arctic sea ice predicted by the Hadley Centre Global Cilimate
Model (GCM) is evaluated using 15 years of passive-microwave data. While the
Hadley model reproduces the seasonal cycle reasonably well, it
underestimates the total area of sea ice by more than 3 × 106
km2 for most of the year. In the winter months, most of the
underestimate in ice area results from the prediction of far too little ice
in Hudson Bay and the Sea of Okhotsk, leading to an excess of up to 0.2 PW
heat input to the atmosphere from Hudson Bay alone. The surface-energy
budget of Hudson Bay is investigated using a mixture of surface observations
(POLES), satellite data (ATSR, SSM/I and ISCCP) and output from the Goddard
Data Assimilation Office analysis. Flux adjustments of the order of 200
Wm−2, resulting from anomalously high sea-surface temperatures
in the Levitus (1982) climatology,
are found to be the cause of the model’s underestimation of sea ice in both
Hudson Bay and the Sea of Okhotsk. The fact that flux adjustments based on
an inaccurate climatology will produce errors, even if the model physics is
correct, underlines the need both for improved climatologies and for models
accurate enough not to require flux adjustment.
Forest ecosystems in South Africa are at risk from a variety of anthropogenic threats impacting the faunal species dependent on them. These impacts often differ depending on species-specific characteristics. Range data on forest dependent bird species from the South African Bird Atlas Project (SABAP1 and SABAP2) were analysed to determine links between deforestation, species characteristics and range declines. Half of the species studied were found to have declining ranges. Range change data for these species were correlated with data on changes in land cover from 1990 to 2014. To determine which land cover changes affect extinction, occupancy was modelled for 30 sites across South Africa which experienced a loss of more than 10 species. Most species lost were birds of prey or insectivores. Indigenous forest decreased in 17% (n = 5) sites, while plantations/woodlots decreased in 60% (n = 18) sites. Occupancy modelling showed extinction to be mitigated by plantations in 6/28 species, and forest expansion mitigated extinction in 7/28 species. Responses to deforestation did not appear to be related to particular species characteristics. Half of South Africa’s forest-dependent bird species have declining ranges, with the loss of these species most prominent in the Eastern Cape province. Four responses to changes in forest and plantation cover are discussed: direct effects, with forest loss causing species loss; matrix effects, where plantation loss resulted in species loss; degradation of indigenous forest; and the advent of new forest arising from woody thickening caused by carbon fertilisation, which may not result in optimal habitat for forest-dependent birds.