524 research outputs found
EAPC task force on education for psychologists in palliative care
It is argued that psychological aspects of care and psychosocial problems are essential components of palliative care. However, the provision of appropriate services remains somewhat arbitrary. Unlike medical and nursing care, which are clearly delivered by doctors and nurses respectively, psychological and psychosocial support in palliative care are not assigned exclusively to psychologists. It is generally expected that all professionals working in palliative care should have some knowledge of the psychological dynamics in terminal illness, as well as skills in communication and psychological risk assessment. On the one hand, palliative care education programmes for nurses and doctors comprise a considerable amount of psychological and psychosocial content. On the other hand, only a few palliative care associations provide explicit information on the role and tasks of psychologists in palliative care. Psychologists’ associations do not deal much with this issue either. If they refer to it at all, it is in the context of the care of the aged, end-of-life care or how to deal with grief
Wideband and on-chip excitation for dynamical spin injection into graphene
Graphene is an ideal material for spin transport as very long spin relaxation
times and lengths can be achieved even at room temperature. However, electrical
spin injection is challenging due to the conductivity mismatch problem. Spin
pumping driven by ferromagnetic resonance is a neat way to circumvent this
problem as it produces a pure spin current in the absence of a charge current.
Here, we show spin pumping into single layer graphene in micron scale devices.
A broadband on-chip RF current line is used to bring micron scale permalloy
(NiFe) pads to ferromagnetic resonance with a magnetic field
tunable resonance condition. At resonance, a spin current is emitted into
graphene, which is detected by the inverse spin hall voltage in a close-by
platinum electrode. Clear spin current signals are detected down to a power of
a few milliwatts over a frequency range of 2 GHz to 8 GHz. This compact device
scheme paves the way for more complex device structures and allows the
investigation of novel materials.Comment: 7 pages, 4 figure
A note on computing a maximal planar subgraph using PQ-trees
The problem of computing a maximal planar subgraph of a non planar graph has been deeply investigated over the last 20 years. Several attempts have been tried to solve the problem with the help of PQ-trees. The latest attempt has been reported by Jayakumar et al. [10]. In this paper we show that the algorithm presented by Jayakumar et al. is not correct. We show that it does not necessarily compute a maximal planar subgraph and we note that the same holds for a modified version of the algorithm presented by Kant [12]. Our conclusions most likely suggest not to use PQ-trees at all for this specific problem
Straight-line Drawability of a Planar Graph Plus an Edge
We investigate straight-line drawings of topological graphs that consist of a
planar graph plus one edge, also called almost-planar graphs. We present a
characterization of such graphs that admit a straight-line drawing. The
characterization enables a linear-time testing algorithm to determine whether
an almost-planar graph admits a straight-line drawing, and a linear-time
drawing algorithm that constructs such a drawing, if it exists. We also show
that some almost-planar graphs require exponential area for a straight-line
drawing
Untersuchung über die Fähigkeit zur Bildung von Mikrokolonien darmpathogener Escherichia coli auf abiotischen Oberflächen
Die Infektion mit Erregern wie Escherichia coli (E. coli) spielt eine immer größere Rolle in der Hygiene. Daher wurde die Fähigkeit von E. coli zur Biofilmbildung auf abiotischen Oberflächen untersucht. Des Weiteren ist die Biofilmbildung auf Oberflächen der Trinkwasserbereitung von großer Bedeutung. Grundlage der Biofilmbildung ist die Fähigkeit zur Bildung von Mikrokolonien. In dieser Untersuchung wurden anhand verschiedener abiotischer Materialien (Glas, PVC, Kupfer) untersucht, in welchem Umfang unterschiedliche darmpathogene E. coli Stämme zur Biofilmbildung auf diesen Materialien fähig sind. Die Ergebnisse wurden semiquantitativ per Licht- und Fluoreszenz-Mikroskopie verifiziert. Ergebnis der Untersuchungen war, dass spezifische pathogene E. coli Stämme (EAEC/EPEC) im Vergleich zum apathogenen Laborstamm vermehrt Mikrokolonie bilden können. Die Ergebnisse zeigen die Bedeutung der Materialabhängigkeit und die Pathovar-spezifische Variabilität der Mikrokoloniebildung von E. coli
Universality-class dependence of energy distributions in spin glasses
We study the probability distribution function of the ground-state energies
of the disordered one-dimensional Ising spin chain with power-law interactions
using a combination of parallel tempering Monte Carlo and branch, cut, and
price algorithms. By tuning the exponent of the power-law interactions we are
able to scan several universality classes. Our results suggest that mean-field
models have a non-Gaussian limiting distribution of the ground-state energies,
whereas non-mean-field models have a Gaussian limiting distribution. We compare
the results of the disordered one-dimensional Ising chain to results for a
disordered two-leg ladder, for which large system sizes can be studied, and
find a qualitative agreement between the disordered one-dimensional Ising chain
in the short-range universality class and the disordered two-leg ladder. We
show that the mean and the standard deviation of the ground-state energy
distributions scale with a power of the system size. In the mean-field
universality class the skewness does not follow a power-law behavior and
converges to a nonzero constant value. The data for the Sherrington-Kirkpatrick
model seem to be acceptably well fitted by a modified Gumbel distribution.
Finally, we discuss the distribution of the internal energy of the
Sherrington-Kirkpatrick model at finite temperatures and show that it behaves
similar to the ground-state energy of the system if the temperature is smaller
than the critical temperature.Comment: 15 pages, 20 figures, 1 tabl
Optimization by thermal cycling
Thermal cycling is an heuristic optimization algorithm which consists of
cyclically heating and quenching by Metropolis and local search procedures,
respectively, where the amplitude slowly decreases. In recent years, it has
been successfully applied to two combinatorial optimization tasks, the
traveling salesman problem and the search for low-energy states of the Coulomb
glass. In these cases, the algorithm is far more efficient than usual simulated
annealing. In its original form the algorithm was designed only for the case of
discrete variables. Its basic ideas are applicable also to a problem with
continuous variables, the search for low-energy states of Lennard-Jones
clusters.Comment: Submitted to Proceedings of the Workshop "Complexity, Metastability
and Nonextensivity", held in Erice 20-26 July 2004. Latex, 7 pages, 3 figure
Intermediate states in Andreev bound state fusion
Hybridization is a very fundamental quantum mechanical phenomenon, with the
text book example of binding two hydrogen atoms in a hydrogen molecule. In
semiconductor physics, a quantum dot (QD) can be considered as an artificial
atom, with two coupled QDs forming a molecular state, and two electrons on a
single QD the equivalent of a helium atom. Here we report tunnel spectroscopy
experiments illustrating the hybridization of another type of discrete quantum
states, namely of superconducting subgap states that form in segments of a
semiconducting nanowire in contact with superconducting reservoirs. We show and
explain a collection of intermediate states found in the process of merging
individual bound states, hybridizing with a central QD and eventually
coherently linking the reservoirs. These results may serve as a guide in future
Majorana fusion experiments and explain a large variety of recent bound state
experiments
Laboratory alcohol self-administration experiments do not increase subsequent real-life drinking in young adult social drinkers
BACKGROUND: While the utility of experimental free-access alcohol self-administration paradigms is well established, little data exist addressing the question of whether study participation influences subsequent natural alcohol consumption. We here present drinking reports of young adults before and after participation in intravenous alcohol self-administration studies.
METHODS: Timeline Follow-back drinking reports for the 6 weeks immediately preceding the first, and the 6 weeks after the last experimental alcohol challenge were examined from subjects completing 1 of 2 similar alcohol self-administration paradigms. In study 1, 18 social drinkers (9 females, mean age 24.1 years) participated in 3 alcohol self-infusion sessions up to a maximum blood alcohol concentration (BAC) of 160 mg%. Study 2 involved 60 participants (30 females, mean age 18.3 years) of the Dresden Longitudinal Study on Alcohol Use in Young Adults (D-LAYA), who participated in 2 sessions of alcohol self-infusion up to a maximum BAC of 120 mg%, and a nonexposed age-matched control group of 42 (28 females, mean age 18.4 years) subjects.
RESULTS: In study 1, participants reported (3.7%) fewer heavy drinking days as well as a decrease of 2.5 drinks per drinking day after study participation compared to prestudy levels (p < 0.05, respectively). In study 2, alcohol-exposed participants reported 7.1% and non-alcohol-exposed controls 6.5% fewer drinking days at poststudy measurement (p < 0.001), while percent heavy drinking days and drinks per drinking day did not differ.
CONCLUSIONS: These data suggest that participation in intravenous alcohol self-administration experiments does not increase subsequent real-life drinking of young adults
Highly symmetric and tunable tunnel couplings in InAs/InP nanowire heterostructure quantum dots
We present a comprehensive electrical characterization of an InAs/InP
nanowire heterostructure, comprising two InP barriers forming a quantum dot
(QD), two adjacent lead segments (LSs) and two metallic contacts, and
demonstrate how to extract valuable quantitative information of the QD. The QD
shows very regular Coulomb blockade (CB) resonances over a large gate voltage
range. By analyzing the resonance line shapes, we map the evolution of the
tunnel couplings from the few to the many electron regime, with electrically
tunable tunnel couplings from 600 eV, and a transition
from the temperature to the lifetime broadened regime. The InP segments form
tunnel barriers with almost fully symmetric tunnel couplings and a barrier
height of ~350 meV. All of these findings can be understood in great detail
based on the deterministic material composition and geometry. Our results
demonstrate that integrated InAs/InP QDs provide a promising platform for
electron tunneling spectroscopy in InAs nanowires, which can readily be
contacted by a variety of superconducting materials to investigate subgap
states in proximitized NW regions, or be used to characterize thermoelectric
nanoscale devices in the quantum regime.Comment: 8 pages, 4 figure
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