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The validity of any glaciological paleo proxy used to interpret climate records is based on the level of understanding of their transfer from the atmosphere into the ice sheet and their recording in the snowpack. Large spatial noise in snow properties is observed, as the wind constantly redistributes the deposited snow at the surface routed by the local topography. To increase the signal-to-noise ratio and getting a representative estimate of snow properties with respect to the high spatial variability, a large number of snow profiles is needed. However, the classical way of obtaining profiles via snow-pits is time and energy-consuming, and thus unfavourable for large surface sampling programs. In response, we present a dual-tube technique to sample the upper metre of the snowpack at a variable depth resolution with high efficiency. The developed device is robust and avoids contact with the samples by exhibiting two tubes attached alongside each other in order to (1) contain the snow core sample and (2) to access the bottom of the sample, respectively. We demonstrate the performance of the technique through two case studies in East Antarctica where we analysed the variability of water isotopes at a 100 m and 5 km spatial scales.
Antarctica's ice shelves modulate the grounded ice flow, and weakening of ice shelves due to climate forcing will decrease their ‘buttressing’ effect, causing a response in the grounded ice. While the processes governing ice-shelf weakening are complex, uncertainties in the response of the grounded ice sheet are also difficult to assess. The Antarctic BUttressing Model Intercomparison Project (ABUMIP) compares ice-sheet model responses to decrease in buttressing by investigating the ‘end-member’ scenario of total and sustained loss of ice shelves. Although unrealistic, this scenario enables gauging the sensitivity of an ensemble of 15 ice-sheet models to a total loss of buttressing, hence exhibiting the full potential of marine ice-sheet instability. All models predict that this scenario leads to multi-metre (1–12 m) sea-level rise over 500 years from present day. West Antarctic ice sheet collapse alone leads to a 1.91–5.08 m sea-level rise due to the marine ice-sheet instability. Mass loss rates are a strong function of the sliding/friction law, with plastic laws cause a further destabilization of the Aurora and Wilkes Subglacial Basins, East Antarctica. Improvements to marine ice-sheet models have greatly reduced variability between modelled ice-sheet responses to extreme ice-shelf loss, e.g. compared to the SeaRISE assessments.
Radiocarbon (14C) ages cannot provide absolutely dated chronologies for archaeological or paleoenvironmental studies directly but must be converted to calendar age equivalents using a calibration curve compensating for fluctuations in atmospheric 14C concentration. Although calibration curves are constructed from independently dated archives, they invariably require revision as new data become available and our understanding of the Earth system improves. In this volume the international 14C calibration curves for both the Northern and Southern Hemispheres, as well as for the ocean surface layer, have been updated to include a wealth of new data and extended to 55,000 cal BP. Based on tree rings, IntCal20 now extends as a fully atmospheric record to ca. 13,900 cal BP. For the older part of the timescale, IntCal20 comprises statistically integrated evidence from floating tree-ring chronologies, lacustrine and marine sediments, speleothems, and corals. We utilized improved evaluation of the timescales and location variable 14C offsets from the atmosphere (reservoir age, dead carbon fraction) for each dataset. New statistical methods have refined the structure of the calibration curves while maintaining a robust treatment of uncertainties in the 14C ages, the calendar ages and other corrections. The inclusion of modeled marine reservoir ages derived from a three-dimensional ocean circulation model has allowed us to apply more appropriate reservoir corrections to the marine 14C data rather than the previous use of constant regional offsets from the atmosphere. Here we provide an overview of the new and revised datasets and the associated methods used for the construction of the IntCal20 curve and explore potential regional offsets for tree-ring data. We discuss the main differences with respect to the previous calibration curve, IntCal13, and some of the implications for archaeology and geosciences ranging from the recent past to the time of the extinction of the Neanderthals.
We study the influence of finite-emittance electron bunches in the bubble regime of laser-driven wakefield acceleration onto the microscopic structure of the bunch itself. Using resilient backpropagation (Rprop) to find the equilibrium structure, we observe that for realistic and already observed emittances the previously found crystalline structures remain intact and are only widened marginally. Higher emittances lead to larger electron displacements within the crystal and finally its breaking.
We present a theory for describing the inner structure of the electron bunch in the bubble regime starting from a random distribution of electrons inside the bubble and subsequently minimizing the system's energy. Consequently, we find a filament-like structure in the direction of propagation that is surrounded by various shells consisting of further electrons. If we specify a two-dimensional (2D) initial structure, we observe a hexagonal structure for a high number of particles, corresponding to the close packing of spheres in two dimensions. The 2D structures are in agreement with the equilibrium slice model.
This paper presents data obtained in a one-day census investigation in five European countries (Austria, Hungary, Romania, Slovakia, Slovenia). The census forms were filled in for 4191 psychiatric inpatients. Concerning legal status, 11.2% were hospitalised against their will (committed) and 21.4% were treated in a ward with locked doors. There was only a small correlation between commitment and treatment in a locked ward. More frequent than treatment of committed patients in locked wards was treatment of committed patients in open wards (Austria, Hungary) and treatment of voluntary patients in closed wards (Slovakia, Slovenia). Concerning employment, 27.7% of patients aged 18–60 held a job before admission. The vast majority of patients (84.8%) had a length of stay of less than 3 months. A comparison of these data with the results of a study performed in 1996 and using the same method shows a decrease of rates of long-stay patients. In 1996 the rates of employment were significantly higher in Romania (39.3%) and Slovakia (42.5%) compared to Austria (30.7%). These differences disappeared in 1999 due to decreasing rates of employment in Romania and Slovakia. The numbers of mental health personnel varies between types of institution (university or non-university) and countries, being highest in Austria and lowest in Romania. A considerable increase in the numbers of staff was found in Slovakia.
Metabolic syndrome and impaired insulin sensitivity may occur as side effects of atypical antipsychotic drugs. However, studies of peripheral insulin resistance using the homeostatic model assessment of insulin resistance (HOMA-IR) or oral glucose tolerance tests (OGTT) suggest that abnormal glucose metabolism is already present in drug-naive first-episode schizophrenia (DNFES). We hypothesized impairments of neuronal insulin signaling in DNFES.
To gain insight into neuronal insulin-signaling in vivo, we analyzed peripheral blood extracellular vesicles enriched for neuronal origin (nEVs). Phosphorylated insulin signal transduction serine-threonine kinases pS312-IRS-1, pY-IRS-1, pS473-AKT, pS9-GSK3β, pS2448-mTOR, pT389-p70S6K and respective total protein levels were determined in plasma nEVs from 48 DNFES patients and healthy matched controls after overnight fasting.
Upstream pS312-IRS-1 was reduced at trend level (p = 0.071; this condition may amplify IRS-1 signaling). Exploratory omnibus analysis of downstream serine-threonine kinases (AKT, GSK3β, mTOR, p70S6K) revealed lower phosphorylated/total protein ratios in DNFES vs. controls (p = 0.013), confirming decreased pathway activation. Post-hoc-tests indicated in particular a reduced phosphorylation ratio of mTOR (p = 0.027). Phosphorylation ratios of p70S6K (p = 0.029), GSK3β (p = 0.039), and at trend level AKT (p = 0.061), showed diagnosis-dependent statistical interactions with insulin blood levels. The phosphorylation ratio of AKT correlated inversely with PANSS-G and PANSS-total scores, and other ratios showed similar trends.
These findings support the hypothesis of neuronal insulin resistance in DNFES, small sample sizes notwithstanding. The counterintuitive trend towards reduced pS312-IRS-1 in DNFES may result from adaptive feedback mechanisms. The observed changes in insulin signaling could be clinically meaningful as suggested by their association with higher PANSS scores.
Comparisons of antipsychotics with placebo can be biased by unblinding due to side effects. Therefore, this meta-analysis compared the efficacy of antipsychotics for acute schizophrenia in trials using barbiturates or benzodiazepines as active placebos.
Randomized controlled trials (RCTs) in acute schizophrenia with at least 3 weeks duration and comparing any antipsychotic with barbiturates or benzodiazepines were eligible. ClinicalTrials.gov, CENTRAL, EMBASE, MEDLINE, PsycINFO, PubMed, WHO-ICTRP as well as previous reviews were searched up to 9 January 2018. Two separate meta-analyses, one for barbiturates and one for benzodiazepines, were conducted using random-effects models. The primary outcome was response to treatment, and mean values of schizophrenia rating scales and dropouts were analyzed as secondary outcomes. This study is registered with PROSPERO (CRD42018086263).
Seven barbiturate-RCTs (number of participants n = 1736), and two benzodiazepine-RCTs (n = 76) were included in the analysis. The studies were published between 1960 and 1968 and involved mainly chronically ill patients. More patients on antipsychotics in comparison to barbiturates achieved a ‘good’ response (36.2% v. 16.8%; RR 2.15; 95% CI 1.36–3.41; I2 = 48.9) and ‘any’ response (57.4% v. 27.8%; RR 2.07; 95% CI 1.35–3.18; I2 = 68.2). In a single small trial (n = 60), there was no difference between antipsychotics and benzodiazepines on ‘any’ response (74.7% v. 65%; RR 1.15; 95% CI 0.82–1.62).
Antipsychotic drugs were more efficacious than barbiturates, based on a large sample size. Response ratios were similar to those observed in placebo-controlled trials. The results on benzodiazepines were inconclusive due to the small number of studies and participants.
Recent progress in video compression is seemingly reaching its limits making it very hard to improve coding efficiency significantly further. The adaptive loop filter (ALF) has been a topic of interest for many years. ALF reaches high coding gains and has motivated many researchers over the past years to further improve the state-of-the-art algorithms. The main idea of ALF is to apply a classification to partition the set of all sample locations into multiple classes. After that, Wiener filters are calculated and applied for each class. Therefore, the performance of ALF essentially relies on how its classification behaves. In this paper, we extensively analyze multiple feature-based classifications for ALF (MCALF) and extend the original MCALF by incorporating sample adaptive offset filtering. Furthermore, we derive new block-based classifications which can be applied in MCALF to reduce its complexity. Experimental results show that our extended MCALF can further improve compression efficiency compared to the original MCALF algorithm.
We report on the concept of an innovative source to produce polarized proton/deuteron beams of a kinetic energy up to several GeV from a laser-driven plasma accelerator. Spin effects have been implemented into the particle-in-cell (PIC) simulation code VLPL (Virtual Laser Plasma Lab) to make theoretical predictions about the behavior of proton spins in laser-induced plasmas. Simulations of spin-polarized targets show that the polarization is conserved during the acceleration process. For the experimental realization, a polarized HCl gas-jet target is under construction using the fundamental wavelength of a Nd:YAG laser system to align the HCl bonds and simultaneously circularly polarized light of the fifth harmonic to photo-dissociate, yielding nuclear polarized H atoms. Subsequently, their degree of polarization is measured with a Lamb-shift polarimeter. The final experiments, aiming at the first observation of a polarized particle beam from laser-generated plasmas, will be carried out at the 10 PW laser system SULF at SIOM, Shanghai.
The study of genocide and mass atrocity abounds with references to emotions: fear, anger, horror, shame and hatred. Yet we don't understand enough about how 'ordinary' emotions behave in such extreme contexts. Emotions are not merely subjective and interpersonal phenomena; they are also powerful social and political forces, deeply involved in the history of mass violence. Drawing on recent insights from philosophy, psychology, history, and the social sciences, this volume examines the emotions of perpetrators, victims, and bystanders. Editors Thomas Brudholm and Johannes Lang have brought together an interdisciplinary group of prominent scholars to provide an in-depth analysis of the nature, value, and role of emotions as they relate to the causes and dynamics of mass atrocities. The result is a new perspective on the social, political, and moral dimensions of emotions in the history of collective violence and its aftermath.