416 research outputs found
The Emission Structure of Formaldehyde MegaMasers
The formaldehyde MegaMaser emission has been mapped for the three host
galaxies IC\,860. IRAS\,151070724, and Arp\,220. Elongated emission
components are found at the nuclear centres of all galaxies with an extent
ranging between 30 to 100 pc. These components are superposed on the peaks of
the nuclear continuum. Additional isolated emission components are found
superposed in the outskirts of the radio continuum structure. The brightness
temperatures of the detected features ranges from 0.6 to 13.4
K, which confirms their masering nature. The masering scenario is interpreted
as amplification of the radio continuum by foreground molecular gas that is
pumped by far-infrared radiation fields in these starburst environments of the
host galaxies.Comment: Accepted MNRA
OpenCL Actors - Adding Data Parallelism to Actor-based Programming with CAF
The actor model of computation has been designed for a seamless support of
concurrency and distribution. However, it remains unspecific about data
parallel program flows, while available processing power of modern many core
hardware such as graphics processing units (GPUs) or coprocessors increases the
relevance of data parallelism for general-purpose computation.
In this work, we introduce OpenCL-enabled actors to the C++ Actor Framework
(CAF). This offers a high level interface for accessing any OpenCL device
without leaving the actor paradigm. The new type of actor is integrated into
the runtime environment of CAF and gives rise to transparent message passing in
distributed systems on heterogeneous hardware. Following the actor logic in
CAF, OpenCL kernels can be composed while encapsulated in C++ actors, hence
operate in a multi-stage fashion on data resident at the GPU. Developers are
thus enabled to build complex data parallel programs from primitives without
leaving the actor paradigm, nor sacrificing performance. Our evaluations on
commodity GPUs, an Nvidia TESLA, and an Intel PHI reveal the expected linear
scaling behavior when offloading larger workloads. For sub-second duties, the
efficiency of offloading was found to largely differ between devices. Moreover,
our findings indicate a negligible overhead over programming with the native
OpenCL API.Comment: 28 page
Sex differences in sleep and influence of the menstrual cycle on women’s sleep in junior endurance athletes
Previous research shows that female athletes sleep better according to objective parameters but report worse subjective sleep quality than male athletes. However, existing sleep studies did not investigate variations in sleep and sleep stages over longer periods and have, so far, not elucidated the role of the menstrual cycle in female athletes’ sleep. To address these methodological shortcomings, we investigated sex differences in sleep and sleep stages over 61 continuous days in 37 men and 19 women and examined the role of the menstrual cycle and its phases in 15 women. Sleep was measured by a non-contact radar, and menstrual bleeding was self-reported. Associations were investigated with multilevel modeling. Overall, women tended to report poorer subjective sleep quality (p = .057), but objective measurements showed that women obtained longer sleep duration (p < .001), more light (p = .013) and rapid eye movement sleep (REM; hours (h): p < .001, %: p = .007), shorter REM latency (p < .001), and higher sleep efficiency (p = .003) than men. R2 values showed that sleep duration, REM and REM latency were especially affected by sex. Among women, we found longer time in bed (p = .027) and deep sleep (h: p = .036), and shorter light sleep (%: p = .021) during menstrual bleeding vs. non-bleeding days; less light sleep (h: p = .040), deep sleep (%: p = .013) and shorter REM latency (p = .011) during the menstrual than pre-menstrual phase; and lower sleep efficiency (p = .042) and more deep sleep (%: p = .026) during the follicular than luteal phase. These findings indicate that the menstrual cycle may impact the need for physiological recovery, as evidenced by the sleep stage variations. Altogether, the observed sex differences in subjective and objective sleep parameters may be related to the female athletes’ menstrual cycle. The paper provides unique data of sex differences in sleep stages and novel insights into the role of the menstrual cycle in sleep among female athletes.publishedVersio
Is environmental behavior related to economic risk preferences? An exploratory case by case analysis
Do risk preferences play a role when deciding whether to act pro-environmentally? Looking at 28 different behaviors case by case – including recycling, waste reduction, energy and water conservation, consumer behavior, and environmental policy support – our data suggest no relation between most of the behaviors and economic risk preferences. However, economic risk preferences appear to have some relevance for travel mode choice and for specific consumer preferences (eco-friendly detergents, organic food, and single-use plastics), perhaps because people are better able to appreciate aspects of these behaviors related to risk (e.g., possibility of traffic accidents, health risks)
The OH Megamaser Emission in Arp\,220: the rest of the story
The OH Megamaser emission in the merging galaxy Arp220 has been re-observed
with the Multi-Element Radio Linked Interferometer Network (MERLIN) and the
European VLBI Network (EVN). Imaging results of the OH line emission at the two
nuclei are found to be consistent with earlier observations and confirm
additional extended emission structures surrounding the nuclei. Detailed
information about the distributed emission components around the two nuclei has
been obtained using a concatenated MERLIN and EVN database with intermediate
(40 mas) spatial resolution. Continuum imaging shows a relatively compact West
nucleus and a more extended East nucleus in addition to an extended continuum
ridge stretching below and beyond the two nuclei. Spectral line imaging show
extended emission regions at both nuclei together with compact components and
additional weaker components north and south of the West nucleus. Spectral line
analysis indicates that the dominant OH line emission originates in foreground
molecular material that is part of a large-scale molecular structure that
engulfs the whole nuclear region. Compact OH components are representative of
star formation regions within the two nearly edge-on nuclei and define the
systemic velocities of East and West as 5425 km/s and 5360 km/s.
The foreground material at East and West has a 100 km/s lower velocity at
5314 and 5254 km/s. These emission results confirm a maser amplification
scenario where the background continuum and the line emission of the star
formation regions are amplified by foreground masering material that is excited
by the FIR radiation field originating in the two nuclear regions.Comment: 17 pages, 18 figure
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The role of family functioning and self-esteem in the quality of life of adolescents referred for psychiatric services: a 3-year follow-up.
PurposeTo investigate, in adolescents referred for psychiatric services, the associations of initial self-esteem and family functioning with level and change of quality of life (QoL) over a 3-year period, over and above the effect of their emotional problems.MethodsOf 1648 eligible 13-18 years old patients attending the child and adolescent psychiatric clinic (CAP) at least once, 717 (54.8% females) were enrolled at baseline (a response rate of 43.5%). Self- and parent reports on the McMaster Family Assessment Device were obtained. Adolescents reported self-esteem on the Rosenberg Scale, and emotional problems on the Symptom Check List-5. Adolescents completed the Inventory of Life Quality in Children and Adolescents (ILC). After 3 years, 570 adolescents again completed the ILC, and for 418 adolescents parent information was available. The longitudinal analysis sample of 418 adolescents was representative of the baseline sample for age, gender, emotional problems, and QoL. We used modified growth-model analysis, adjusted for SES, age, gender and time of contact with CAP, where residual variances for ILC at baseline and follow-up were fixed to 0.ResultsA poorer family functioning at baseline, reported by parents, was significantly associated with worsening QoL during the 3 years follow-up period (p = 0.001).ConclusionsParents have important knowledge about their families that may reflect long-term influences on QoL development in adolescent psychiatric patients. Health care providers and policy makers should optimize treatment outcomes by addressing family functioning in adolescents with emotional problems
HDArray: Parallel Array Interface for Distributed Heterogeneous Devices
Heterogeneous clusters with nodes containing one or more accelerators, such as GPUs, have become common. While MPI provides a mechanism and management of interaddress space communication, and OpenCL provides a way to manage computation and communication within a process with access to heterogeneous computational resources, programmers are forced to write hybrid programs that manage the interaction of both of these systems. This paper describes an array programming interface that provides users with automatic or manual distributions of data and work. Using the distribution and information about what data is used and defined by kernels, communication among processes and among devices in a process is performed automatically. The interface provides a unified programming model to the user, thus simplifying program development
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