3,861 research outputs found
Some Like It Fat: Comparative Ultrastructure of the Embryo in Two Demosponges of the Genus Mycale (Order Poecilosclerida) from Antarctica and the Caribbean
0000-0002-7993-1523© 2015 Riesgo et al. This is an open access article distributed under the terms of the Creative Commons Attribution License [4.0], which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. The attached file is the published version of the article
Synthetic X-ray emission from white dwarf accreting planetary material
The emission of hard X-rays associated with white dwarfs (WD) can be
generated by the presence of a stellar companion either by the companion's
coronal emission or by an accretion disk formed by material stripped from the
companion. Recent studies have suggested that a Jupiter-like planet can also be
donor of material whose accretion onto the WD can generate hard X-rays. We use
the {\sc guacho} code to reproduce the conditions of this WD-planet scenario.
With the example of the hard X-ray WD KPD\,0005+5106, we explore different
terminal wind velocities and mass-loss rates of a donor planet for a future
network of simulations to investigate the luminosity and the spectral and
temporal properties of the hard X-ray emission in WD-planet systems. Our
simulations show that the material stripped from the planet forms a disk and
accretes onto the WD to reach temperatures high enough to generate hard X-rays
as usually seen in X-ray binaries with low-mass companions. For high terminal
wind velocities, the planet material does not form a disk, but it rather
accretes directly onto the WD surface. The simulations reproduce the X-ray
luminosity of another X-ray accreting WD (G\,2938), and only for some times
reaches the hard X-ray luminosity of KPD\,0005+5106. The X-ray variability is
stochastic and does not reproduce the period of KPD\,0005+5106, suggesting that
additional physical processes (e.g., hot spots resulting from magnetic
channelling of the accreting material) need to be explored.Comment: 16 pages, 13 figure
What does touch tell us about emotions in touchscreen-based gameplay?
This is the post-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2012 ACM. It is posted here by permission of ACM for your personal use. Not for redistribution.Nowadays, more and more people play games on touch-screen mobile phones. This phenomenon raises a very interesting question: does touch behaviour reflect the player’s emotional state? If possible, this would not only be a valuable evaluation indicator for game designers, but also for real-time personalization of the game experience. Psychology studies on acted touch behaviour show the existence of discriminative affective profiles. In this paper, finger-stroke features during gameplay on an iPod were extracted and their discriminative power analysed. Based on touch-behaviour, machine learning algorithms were used to build systems for automatically discriminating between four emotional states (Excited, Relaxed, Frustrated, Bored), two levels of arousal and two levels of valence. The results were very interesting reaching between 69% and 77% of correct discrimination between the four emotional states. Higher results (~89%) were obtained for discriminating between two levels of arousal and two levels of valence
Global Health Needs Modernized Containment Strategies to Prepare for the Next Pandemic
COVID-19 continues to be a public health crisis, while severely impacting global financial markets causing significant economic and social hardship. As with any emerging disease, pharmaceutical interventions required time, emphasizing the initial and continuing need for non-pharmaceutical interventions. We highlight the role of anthropological and historical perspectives to inform approaches to non-pharmaceutical interventions for future preparedness. The National Academy of Medicine, a not-for-profit, non-governmental US-based medical watchdog organization, published a key document early in the COVID-19 pandemic which points to inadequate quarantine and containment infrastructure as a significant obstacle to an effective pandemic response. In considering how to implement effective quarantine policies and infrastructure, we argue that it is essential to take a longitudinal approach to assess interventions that have been effective in past pandemics while simultaneously addressing and eliminating the negative socio-historical legacies of ineffective quarantine practices. Our overview reinforces the need for social equity and compassion when implementing containment
Large-scale Nonlinear Variable Selection via Kernel Random Features
We propose a new method for input variable selection in nonlinear regression.
The method is embedded into a kernel regression machine that can model general
nonlinear functions, not being a priori limited to additive models. This is the
first kernel-based variable selection method applicable to large datasets. It
sidesteps the typical poor scaling properties of kernel methods by mapping the
inputs into a relatively low-dimensional space of random features. The
algorithm discovers the variables relevant for the regression task together
with learning the prediction model through learning the appropriate nonlinear
random feature maps. We demonstrate the outstanding performance of our method
on a set of large-scale synthetic and real datasets.Comment: Final version for proceedings of ECML/PKDD 201
Establishing Best Practices for X-57 Maxwell CFD Database Generation
The X-57 Maxwell is NASAs latest electric airplane concept that has been simulated for aerodynamic performance using the structured overset and unstructured grid solvers within the Launch Ascent and Vehicle Aerodynamics (LAVA) solver framework as well as the unstructured polyhedral grid solver in Star-CCM+ for code-to-code comparison. In order to validate the predictions, comparisons were made between the CFD solutions and experimental data collected in the 12-foot Low-Speed Wind Tunnel at NASA Langley Research Center. The simulations are in preparation for the development of a comprehensive aerodynamic database which will assess aircraft performance at a variety of conditions. The findings from these simulations will establish the best practices for mesh resolution, numerical discretization, and turbulence modeling to be used for this database. Preliminary database results have shown that best-practices learned from the initial validation simulations will potentially reduce error in X-57 aerodynamic loads and moments relative to experiment by up to 14%
Examining the Relationship between Community Orientation and Hospital Financial Performance
A community orientation strategy may be a socially responsible way for hospitals to simultaneously improve financial performance and community health, in accordance with the Affordable Care Act. Using data from the AHA Annual Survey, AHRF, and CMS Cost Reports, this study examined the association between hospital community orientation and three measures of financial performance, and whether that relationship differs for some types of hospitals. The analysis revealed that hospital community orientation was positively associated with total margin and that not-for-profit hospitals engaging in higher levels of community orientation experienced lower operating margins, on average, relative to for-profit hospital
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