2,569 research outputs found
Astropy: A community Python package for astronomy
We present the first public version (v0.2) of the open-source and community-developed Python package, Astropy. This package provides core astronomy-related functionality to the community, including support for domain-specific file formats such as flexible image transport system (FITS) files, Virtual Observatory (VO) tables, and common ASCII table formats, unit and physical quantity conversions, physical constants specific to astronomy, celestial coordinate and time transformations, world coordinate system (WCS) support, generalized containers for representing gridded as well as tabular data, and a framework for cosmological transformations and conversions. Significant functionality is under active development, such as a model fitting framework, VO client and server tools, and aperture and point spread function (PSF) photometry tools. The core development team is actively making additions and enhancements to the current code base, and we encourage anyone interested to participate in the development of future Astropy versions
Rapid fabrication of 3D terahertz split ring resonator arrays by novel single-shot direct write focused proximity field nanopatterning
For the next generation of phoXonic, plasmonic, optomechanical
and microfluidic devices, the capability to create 3D
microstructures is highly desirable. Fabrication of such structures by
conventional top-down techniques generally requires multiple timeconsuming
steps and is limited in the ability to define features spanning
multiple layers at prescribed angles. 3D direct write lithography (3DDW)
has the capability to draw nearly arbitrary structures, but is an inherently
slow serial writing process. Here we present a method, denoted focused
proximity field nanopatterning (FPnP), that combines 3DDW with single or
multiphoton interference lithography (IL). By exposing a thick photoresist
layer having a phase mask pattern imprinted on its surface with a tightly
focused laser beam, we produce locally unique complex structures. The
morphology can be varied based on beam and mask parameters. Patterns
may be written rapidly in a single shot mode with arbitrary positions
defined by the direct write, thus exploiting the control of 3DDW with the
enhanced speed of phase mask IL. Here we show the ability for this
technique to rapidly produce arrays of “stand-up” far IR resonators
Adaptive and maladaptive consequences of “matching habitat choice:” lessons from a rapidly-evolving butterfly metapopulation
Relationships between biased dispersal and local adaptation are currently debated. Here, I show how prior work on wild butterflies casts a novel light on this topic. “Preference” is defined as the set of likelihoods of accepting particular resources after encountering them. So defined, butterfly oviposition preferences are heritable habitat adaptations distinct from both habitat preference and biased dispersal, but influencing both processes. When a butterfly emigrates after its oviposition preference begins to reduce realized fecundity, the resulting biased dispersal is analogous to that occurring when a fish emigrates after its morphological habitat adaptations reduce its feeding rate. I illustrate preference-biased dispersal with examples from metapopulations of Melitaea cinxia and Euphydryas editha. E. editha were feeding on a well-defended host, Pedicularis, when humans created patches in which Pedicularis was killed and a less-defended host, Collinsia, was rendered phenologically available. Patch-specific natural selection favoured oviposition on Collinsia in logged (“clearing”) patches and on Pedicularis in undisturbed open forest. Quantitative variation in post-alighting oviposition preference was heritable, and evolved to be consistently different between patch types. This difference was driven more by biased dispersal than by spatial variation of natural selection. Insects developing on Collinsia in clearings retained adaptations to Pedicularis in clutch size, geotaxis and oviposition preference, forcing them to choose between emigrating in search of forest habitats with Pedicularis or staying and failing to find their preferred host. Insects that stayed suffered reduction of realized fecundity after delayed oviposition on Collinsia. Those that emigrated suffered even greater fitness penalty from consistently low offspring survival on Pedicularis. Paradoxically, most emigrants reduced both their own fitness and that of the recipient populations by dispersing from a benign natal habitat to which they were maladapted into a more demanding habitat to which they were well-adapted. “Matching habitat choice” reduced fitness when evolutionary lag rendered traditional cues unreliable in a changing environment
Ariel - Volume 10 Number 3
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The effect of pre-shot routines on golf wedge shot performance
The objective of this study was to examine the effect of pre-performance routines among golfers of low skill and non-golfers on wedge golf shot performance. The intervention strategies involved a physical skill and cognitive-behavioral routine program, as well as a physical skills-only program. Performance was measured on a pre-intervention test, postintervention test, and following a period of time without treatment, and involved wedge shots being played from distances of 40, 50, and 60 m from a target. Participants in this study (N = 68) were assigned to either a golfer or non-golfer group. Participants in the treatment groups attended 2 practice sessions per week during the acquisition phase. A variable practice design was incorporated during the intervention phase. Non-golfers in both intervention groups improved performance following the acquisition phase and maintained these levels of performance in the retention test. Greater improvements in performance were found in the non-golfer physical skills and cognitive-behavioral routine group. The non-golfer physical skills and cognitive-behavioral routine group was the only group to realize significant improvements in performance when comparing initial test performance measures to post-intervention and retention test performance measures across all test distances. Although the golfer treatment groups had consistent improvement in performance measures following the intervention phase, these improvements did not reach statistical significance in the majority of cases
Composition of the L5 Mars Trojans: Neighbors, not Siblings
Mars is the only terrestrial planet known to have Tro jan (co-orbiting)
asteroids, with a confirmed population of at least 4 objects. The origin of
these objects is not known; while several have orbits that are stable on
solar-system timescales, work by Rivkin et al. (2003) showed they have
compositions that suggest separate origins from one another. We have obtained
infrared (0.8-2.5 micron) spectroscopy of the two largest L5 Mars Tro jans, and
confirm and extend the results of Rivkin et al. (2003). We suggest that the
differentiated angrite meteorites are good spectral analogs for 5261 Eureka,
the largest Mars Trojan. Meteorite analogs for 101429 1998 VF31 are more varied
and include primitive achondrites and mesosiderites.Comment: 14 manuscript pages, 1 table, 6 figures. To be published in Icarus.
See companion paper 0709.1921 by Trilling et a
Screening for alcoholism
Alcoholism is one of the largest public health problems of the nation and is a significant cofactor in such ubiquitous diseases as hypertension, developmental abnormalities, heart failure, liver failure, and many other conditions. The cost to the nation's health is immense. One strategy for reducing morbidity and cost has been to establish methods for screening in order to increase recognition rates leading to increased rates of therapeutic intervention. In this article, the rationale for two methods of alcohol screening, brief interviews and biological markers of excessive drinking, the relevant statistical issues bearing on this problem, and the current research on screening exams are reviewed and summarized. Finally, some of the newer approaches toward alcoholism screening as well as the consequences to the medical care system should alcohol screening eventuate on a large scale are briefly described.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27168/1/0000164.pd
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