152 research outputs found
A new neutron study of the short range order inversion in FeCr
We have performed new neutron diffuse scattering measurements in
FeCr solid solutions, in a concentration range 0x0.15, where
the atomic distribution shows an inversion of the short range order. By
optimizing the signal-background ratio, we obtain an accurate determination of
the concentration of inversion x =0.110(5). We determine the near neighbor
atomic short range order parameters and pair potentials, which change sign at
x. The experimental results are compared with previous first principle
calculations and atomistic simulations.Comment: 6 pages; 6 figure
Shell-Model Effective Operators for Muon Capture in ^{20}Ne
It has been proposed that the discrepancy between the partially-conserved
axial-current prediction and the nuclear shell-model calculations of the ratio
in the muon-capture reactions can be solved in the case of ^{28}Si by
introducing effective transition operators. Recently there has been
experimental interest in measuring the needed angular correlations also in
^{20}Ne. Inspired by this, we have performed a shell-model analysis employing
effective transition operators in the shell-model formalism for the transition
. Comparison of
the calculated capture rates with existing data supports the use of effective
transition operators. Based on our calculations, as soon as the experimental
anisotropy data becomes available, the limits for the ratio can be
extracted.Comment: 9 pages, 3 figures include
Parameter-based evaluation of attentional impairments in schizophrenia and their modulation by prefrontal transcranial direct current stimulation
Background: Attentional dysfunctions constitute core cognitive symptoms in schizophrenia, but the precise underlying neurocognitive mechanisms remain to be elucidated.
Methods: In this randomized, double-blind, sham-controlled study, we applied, for the first time, a theoretically grounded modeling approach based on Bundesen’s Theory of Visual Attention (TVA) to (i) identify specific visual attentional parameters affected in schizophrenia and (ii) assess, as a proof of concept, the potential of single-dose anodal transcranial direct current stimulation (tDCS; 20 min, 2 mA) to the left dorsolateral prefrontal cortex to modulate these attentional parameters. To that end, attentional parameters were measured before (baseline), immediately after, and 24 h after the tDCS intervention in 20 schizophrenia patients and 20 healthy controls.
Results: At baseline, analyses revealed significantly reduced visual processing speed and visual short-term memory storage capacity in schizophrenia. A significant stimulation condition × time point interaction in the schizophrenia patient group indicated improved processing speed at the follow-up session only in the sham condition (a practice effect), whereas performance remained stable across the three time points in patients receiving verum stimulation. In healthy controls, anodal tDCS did not result in a significant change in attentional performance.
Conclusion: With regard to question (i) above, these findings are indicative of a processing speed and short-term memory deficit as primary sources of attentional deficits in schizophrenia. With regard to question (ii), the efficacy of single-dose anodal tDCS for improving (speed aspects of visual) cognition, it appears that prefrontal tDCS (at the settings used in the present study), rather than ameliorating the processing speed deficit in schizophrenia, actually may interfere with practice-dependent improvements in the rate of visual information uptake. Such potentially unexpected effects of tDCS ought to be taken into consideration when discussing its applicability in psychiatric populations. The study was registered at http://apps.who.int/trialsearch/Trial2.aspx?TrialID=DRKS00011665
Technical design and performance of the NEMO3 detector
The development of the NEMO3 detector, which is now running in the Frejus
Underground Laboratory (L.S.M. Laboratoire Souterrain de Modane), was begun
more than ten years ago. The NEMO3 detector uses a tracking-calorimeter
technique in order to investigate double beta decay processes for several
isotopes. The technical description of the detector is followed by the
presentation of its performance.Comment: Preprint submitted to Nucl. Instrum. Methods A Corresponding author:
Corinne Augier ([email protected]
Nurse managers' experience with ethical issues in six government hospitals in Malaysia: A cross-sectional study
<p>Abstract</p> <p>Background</p> <p>Nurse managers have the burden of experiencing frequent ethical issues related to both their managerial and nursing care duties, according to previous international studies. However, no such study was published in Malaysia. The purpose of this study was to explore nurse managers' experience with ethical issues in six government hospitals in Malaysia including learning about the way they dealt with the issues.</p> <p>Methods</p> <p>A cross-sectional study was conducted in August-September, 2010 involving 417 (69.2%) of total 603 nurse managers in the six Malaysian government hospitals. Data were collected using three-part self-administered questionnaire. Part I was regarding participants' demographics. Part II was about the frequency and areas of management where ethical issues were experienced, and scoring of the importance of 11 pre-identified ethical issues. Part III asked how they dealt with ethical issues in general; ways to deal with the 11 pre-identified ethical issues, and perceived stress level. Data were analyzed using descriptive statistics, cross-tabulations and Pearson's Chi-square.</p> <p>Results</p> <p>A total of 397 (95.2%) participants experienced ethical issues and 47.2% experienced them on weekly to daily basis. Experiencing ethical issues were not associated with areas of practice. Top area of management where ethical issues were encountered was "staff management", but "patient care" related ethical issues were rated as most important. Majority would "discuss with other nurses" in dealing generally with the issues. For pre-identified ethical issues regarding "patient care", "discuss with doctors" was preferred. Only 18.1% referred issues to "ethics committees" and 53.0% to the code of ethics.</p> <p>Conclusions</p> <p>Nurse managers, regardless of their areas of practice, frequently experienced ethical issues. For dealing with these, team-approach needs to be emphasized. Proper understanding of the code of ethics is needed to provide basis for reasoning.</p
Handbook on the Carpathian Convention
This volume describes, article by article, the Carpathian Convention: the principles of international environmental law beyond each article, giving uselful examples of best practices and a detailed overview of the international documents providing guidance to its implementation. It is targeted at policy makers and all stakeholders involved in the implementationof the Convention itself
Patterns in recent and Holocene pollen accumulation rates across Europe - the Pollen Monitoring Programme Database as a tool for vegetation reconstruction
The collection of modern, spatially extensive pollen data is important for the interpretation of fossil pollen assemblages and the reconstruction of past vegetation communities in space and time. Modern datasets are readily available for percentage data but lacking for pollen accumulation rates (PARs). Filling this gap has been the motivation of the pollen monitoring network, whose contributors monitored pollen deposition in modified Tauber traps for several years or decades across Europe. Here we present this monitoring dataset consisting of 351 trap locations with a total of 2742 annual samples covering the period from 1981 to 2017. This dataset shows that total PAR is influenced by forest cover and climate parameters, which determine pollen productivity and correlate with latitude. Treeless vegetation produced PAR values of at least 140 grains cm(-2) yr(-1). Tree PAR increased by at least 400 grains cm(-2) yr(-1) with each 10% increase in forest cover. Pollen traps situated beyond 200 km of the distribution of a given tree species still collect occasional pollen grains of that species. The threshold of this long-distance transport differs for individual species and is generally below 60 grains cm(-2) yr(-1). Comparisons between modern and fossil PAR from the same regions show similar values. For temperate taxa, modern analogues for fossil PARs are generally found downslope or southward of the fossil sites. While we do not find modern situations comparable to fossil PAR values of some taxa (e.g. Corylus), CO2 fertilization and land use may cause high modern PARs that are not documented in the fossil record. The modern data are now publicly available in the Neotoma Paleoecology Database and aid interpretations of fossil PAR data.Peer reviewe
Polydendrocytes Display Large Lineage Plasticity following Focal Cerebral Ischemia
Polydendrocytes (also known as NG2 glial cells) constitute a fourth major glial cell type in the adult mammalian central nervous system (CNS) that is distinct from other cell types. Although much evidence suggests that these cells are multipotent in vitro, their differentiation potential in vivo under physiological or pathophysiological conditions is still controversial
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