67,025 research outputs found
Evo-devo of human adolescence: beyond disease models of early puberty
Despite substantial heritability in pubertal development, much variation remains to be explained, leaving room for the influence of environmental factors to adjust its phenotypic trajectory in the service of fitness goals. Utilizing evolutionary development biology (evo-devo), we examine adolescence as an evolutionary life-history stage in its developmental context. We show that the transition from the preceding stage of juvenility entails adaptive plasticity in response to energy resources, other environmental cues, social needs of adolescence and maturation toward youth and adulthood. Using the evolutionary theory of socialization, we show that familial psychosocial stress fosters a fast life history and reproductive strategy rather than early maturation being just a risk factor for aggression and delinquency. Here we explore implications of an evolutionary-developmental-endocrinological-anthropological framework for theory building, while illuminating new directions for research
EbbRT: a framework for building per-application library operating systems
Efficient use of high speed hardware requires operating system components be customized to the application work- load. Our general purpose operating systems are ill-suited for this task. We present EbbRT, a framework for constructing per-application library operating systems for cloud applications. The primary objective of EbbRT is to enable high-performance in a tractable and maintainable fashion. This paper describes the design and implementation of EbbRT, and evaluates its ability to improve the performance of common cloud applications. The evaluation of the EbbRT prototype demonstrates memcached, run within a VM, can outperform memcached run on an unvirtualized Linux. The prototype evaluation also demonstrates an 14% performance improvement of a V8 JavaScript engine benchmark, and a node.js webserver that achieves a 50% reduction in 99th percentile latency compared to it run on Linux
On the GBM event seen 0.4 sec after GW 150914
In view of the recent report by Connaughton we analyse continuous TTE data of
Fermi-GBM around the time of the gravitational wave event GW 150914. We find
that after proper accounting for low count statistics, the GBM transient event
at 0.4 s after GW 150914 is likely not due to an astrophysical source, but
consistent with a background fluctuation, removing the tension between the
INTEGRAL/ACS non-detection and GBM. Additionally, reanalysis of other short
GRBs shows that without proper statistical modeling the fluence of faint events
is over-predicted, as verified for some joint GBM-ACS detections of short GRBs.
We detail the statistical procedure to correct these biases. As a result, faint
short GRBs, verified by ACS detections, with significances in the broad-band
light curve even smaller than that of the GBM-GW150914 event are recovered as
proper non-zero source, while the GBM-GW150914 event is consistent with zero
fluence.Comment: 13 pages, 12 figures, ApJL (acc.); subm. 2016 March 10, Apr 21 (1st
rev.), May 13 (2nd rev), Jun 1 (3rd rev), and editorial changes by Jun 2 (4th
rev), Jun 8 (5th rev): Our manuscript refers exclusively to
arXiv:1602.03920.v3 since we had no prior access to arXiv:1602.03920.v4/5
(2016 May 31). Note that JG and HFY are not co-authors on
arXiv:1602.03920.v4/
The Astro-WISE approach to quality control for astronomical data
We present a novel approach to quality control during the processing of
astronomical data. Quality control in the Astro-WISE Information System is
integral to all aspects of data handing and provides transparent access to
quality estimators for all stages of data reduction from the raw image to the
final catalog. The implementation of quality control mechanisms relies on the
core features in this Astro-WISE Environment (AWE): an object-oriented
framework, full data lineage, and both forward and backward chaining. Quality
control information can be accessed via the command-line awe-prompt and the
web-based Quality-WISE service. The quality control system is described and
qualified using archive data from the 8-CCD Wide Field Imager (WFI) instrument
(http://www.eso.org/lasilla/instruments/wfi/) on the 2.2-m MPG/ESO telescope at
La Silla and (pre-)survey data from the 32-CCD OmegaCAM instrument
(http://www.astro-wise.org/~omegacam/) on the VST telescope at Paranal.Comment: Accepted for publication in topical issue of Experimental Astronomy
on Astro-WISE information syste
Two-Dimensional Line Strength Maps in Three Well-studied Early-Type Galaxies
Integral field spectroscopy has been obtained for the nuclear regions of 3
large, well-studied, early-type galaxies. From these spectra we have obtained
line strength maps for about 20 absorption lines, mostly belonging to the Lick
system. An extensive comparison with multi-lenslet spectroscopy shows that
accurate kinematic maps can be obtained, and also reproducible line strength
maps. Comparison with long-slit spectroscopy also produces good agreement. We
show that Mg is enhanced with respect to Fe in the inner disk of one of the
three galaxies studied, the Sombrero. [Mg/Fe] there is larger than in the rest
of the bulge. The large values of Mg/Fe in the central disk are consistent with
the centres of other early-type galaxies, and not with large disks, like the
disk of our Galaxy, where [Mg/Fe] is approximately 0. We confirm with this
observation a recent result of Worthey (1998) that Mg/Fe is determined by the
central kinetic energy, or escape velocity, of the stars, only, and not by the
formation time scale of the stars. A stellar population analysis using the
models of Vazdekis et al. (1996) shows that our observed H gamma agrees well
with what is predicted based on the other lines. Using the line strength of the
Ca II IR triplet as an indicator of the abundance of Ca, we find that Ca
follows Fe, and not Mg, in these galaxies. This is peculiar, given the fact
that Ca is an alpha-element. Finally, by combining the results of this paper
with those of Vazdekis et al. (1997) we find that the line strength gradients
in the three galaxies are primarily caused by variations in metallicity.Comment: 23 pages, Latex, includes mn.sty, accepted for publication in Monthly
Notices of the Royal Astronomical Societ
Web-Based Visualization of Very Large Scientific Astronomy Imagery
Visualizing and navigating through large astronomy images from a remote
location with current astronomy display tools can be a frustrating experience
in terms of speed and ergonomics, especially on mobile devices. In this paper,
we present a high performance, versatile and robust client-server system for
remote visualization and analysis of extremely large scientific images.
Applications of this work include survey image quality control, interactive
data query and exploration, citizen science, as well as public outreach. The
proposed software is entirely open source and is designed to be generic and
applicable to a variety of datasets. It provides access to floating point data
at terabyte scales, with the ability to precisely adjust image settings in
real-time. The proposed clients are light-weight, platform-independent web
applications built on standard HTML5 web technologies and compatible with both
touch and mouse-based devices. We put the system to the test and assess the
performance of the system and show that a single server can comfortably handle
more than a hundred simultaneous users accessing full precision 32 bit
astronomy data.Comment: Published in Astronomy & Computing. IIPImage server available from
http://iipimage.sourceforge.net . Visiomatic code and demos available from
http://www.visiomatic.org
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