1,578 research outputs found
Tabanidae of Mexico, Central America and the West Indies
http://deepblue.lib.umich.edu/bitstream/2027.42/56601/1/OP162.pd
Co-operative experiments made by the Ohio Agricultural Students' Union in 1896
Caption title.Mode of access: Internet
Opaque Service Virtualisation: A Practical Tool for Emulating Endpoint Systems
Large enterprise software systems make many complex interactions with other
services in their environment. Developing and testing for production-like
conditions is therefore a very challenging task. Current approaches include
emulation of dependent services using either explicit modelling or
record-and-replay approaches. Models require deep knowledge of the target
services while record-and-replay is limited in accuracy. Both face
developmental and scaling issues. We present a new technique that improves the
accuracy of record-and-replay approaches, without requiring prior knowledge of
the service protocols. The approach uses Multiple Sequence Alignment to derive
message prototypes from recorded system interactions and a scheme to match
incoming request messages against prototypes to generate response messages. We
use a modified Needleman-Wunsch algorithm for distance calculation during
message matching. Our approach has shown greater than 99% accuracy for four
evaluated enterprise system messaging protocols. The approach has been
successfully integrated into the CA Service Virtualization commercial product
to complement its existing techniques.Comment: In Proceedings of the 38th International Conference on Software
Engineering Companion (pp. 202-211). arXiv admin note: text overlap with
arXiv:1510.0142
Asteroid 1986 DA: Radar evidence for a metallic composition
Radar observations of the near-Earth asteroid 1986 DA were carried out at the Arecibo Observatory in April 1986, two months after its discovery. Radar results are consistent with the hypothesis that 1986 HA is a piece of NiFe metal derived from the interior of a much larger object that melted, differentiated, cooled and subsequently was disrupted in a catastrophic collision. This 2-km asteroid might be (or have been part of) the parent body of some iron meteorites. Or 1986 DA might share the parentage and/or part of the dynamical history of some meteorites without ever having contributed any of its own ejecta to our meteorite sample. Analysis of the samples returned from 1986 DA might ultimately involve economic considerations. Meteoritic metal is mostly iron with about 8 percent nickel, but also contains substantial concentrations of precious and strategic metals, including approx. 1 ppm of gold and approx. 10 ppm of platinum group elements. If these abundances apply to 1986 DA, it contains some 10(exp 16) g of iron, 10 (exp 15) g of nickel, 10(exp 11) g of platinum group metals, and 10(exp 10) g of gold
Clinical Toxicologic Studies on Freon R FE 1301
After conducting appropriate animal tests to ascertain safe levels, human subjects were exposed to concentrations of from 1.25% to 16.9% V/V of FE 1301. Assessment of judgement, alertness and neuromuscular skill indicated minimal but discernible effects at the lowest concentration in some individuals. At 10% V/V all subjects were effected. Stage I anesthesia occurred at 15% and Stage II would probably have occurred at 20%. A marked cardiac arrhythmia resulted in one subject exposed to 14%. There was complete recovery in all subjects within 20 minutes after exposure. No liver dysfunction occurred. The critical level for effective fire control is near 6%. This level would be acceptable on clinical toxicologic criteria
On the possible existence of short-period g-mode instabilities powered by nuclear burning shells in post-AGB H-deficient (PG1159-type) stars
We present a pulsational stability analysis of hot post-AGB H-deficient
pre-white dwarf stars with active He-burning shells. The stellar models
employed are state-of-the-art equilibrium structures representative of PG1159
stars derived from the complete evolution of the progenitor stars. On the basis
of fully nonadiabatic pulsation computations, we confirmed theoretical evidence
for the existence of a separate PG1159 instability strip in the diagram characterized by short-period -modes excited by the
-mechanism. This instability strip partially overlaps the already
known GW Vir instability strip of intermediate/long period -modes
destabilized by the classical -mechanism acting on the partial
ionization of C and/or O in the envelope of PG1159 stars. We found that PG1159
stars characterized by thick He-rich envelopes and located inside this
overlapping region could exhibit both short and intermediate/long periods
simultaneously. we study the particular case of VV 47, a pulsating planetary
nebula nucleus that has been reported to exhibit a series of unusually short
pulsation periods. We found that the long periods exhibited by VV 47 can be
readily explained by the classical -mechanism, while the observed
short-period branch below s could correspond to modes triggered
by the He-burning shell through the -mechanism, although more
observational work is needed to confirm the reality of these short-period
modes. Were the existence of short-period -modes in this star convincingly
confirmed by future observations, VV 47 could be the first known pulsating star
in which both the -mechanism and the -mechanism of mode
driving are simultaneously operating.Comment: 9 pages, 5 figures, 2 tables. To be published in The Astrophysical
Journa
The Wilderness Expedition: An effective life course intervention to improve young peoples well-being and connectedness to nature
It is well understood that wilderness expeditions improve well-being; however, there is little supporting quantitative data. The aim of this study was to measure the impact of wilderness expeditions on self-esteem (SE) and connectedness to nature (CN) and assess whether benefits varied according to participant and expedition characteristics. SE and CN were assessed pre– and post–wilderness expeditions in 130 adolescents using Rosenberg’s SE scale and the state CN scale. Two-way ANOVA revealed significant increases in SE and CN (p < .001) as a result of single expeditions. There was also an interaction effect of expedition and gender on SE (p < .05). Males had a higher SE at the start but female SE increased most. Linear regression revealed that living environment, gender, and the length and location of the expedition did not contribute to changes in SE and CN. Regular contact with natural environments will improve adolescent well-being, with the largest improvements in females
The elevated Curie temperature and half-metallicity in the ferromagnetic semiconductor LaEuO
Here we study the effect of La doping in EuO thin films using SQUID
magnetometry, muon spin rotation (SR), polarized neutron reflectivity
(PNR), and density functional theory (DFT). The SR data shows that the
LaEuO is homogeneously magnetically ordered up to its
elevated . It is concluded that bound magnetic polaron behavior does
not explain the increase in and an RKKY-like interaction is
consistent with the SR data. The estimation of the magnetic moment by DFT
simulations concurs with the results obtained by PNR, showing a reduction of
the magnetic moment per LaEuO for increasing lanthanum doping.
This reduction of the magnetic moment is explained by the reduction of the
number of Eu-4 electrons present in all the magnetic interactions in EuO
films. Finally, we show that an upwards shift of the Fermi energy with La or Gd
doping gives rise to half-metallicity for doping levels as high as 3.2 %.Comment: 7 pages, 11 figure
“It’s like my life but more, and better!” - Playing with the Cathaby Shark Girls: MMORPGs, young people and fantasy-based social play
This article is available open access through the publisher’s website at the link below. Copyright @ 2011 A B Academic Publishers.Digital technology has opened up a range of new on-line leisure spaces for young people. Despite their popularity, on-line games and Massive Multiplayer Online Role Playing Games in particular are still a comparatively under-researched area in the fields of both Education and more broadly Youth Studies. Drawing on a Five year ethnographic study, this paper considers the ways that young people use the virtual spaces offered by MMORPGs. This paper suggests that MMORPGs represent significant arenas within which young people act out a range of social narratives through gaming. It argues that MMORPG have become important fantasy spaces which offer young people possibilities to engage in what were formally material practices. Although this form of play is grounded in the everyday it also extends material practices and offers new and unique forms of symbolic experimentation, thus I argue that game-play narratives cannot be divorced from the everyday lives of their participants
Self-focused pulse propagation is mediated by spatiotemporal optical vortices
We show that the dynamics of high-intensity laser pulses undergoing
self-focused propagation in a nonlinear medium can be understood in terms of
the topological constraints imposed by the formation and evolution of
spatiotemporal optical vortices (STOVs). STOVs are born from point phase
defects on the sides of the pulse nucleated by spatiotemporal phase shear.
These defects grow into closed loops of spatiotemporal vorticity that initially
exclude the pulse propagation axis, but then reconnect to form a pair of
toroidal vortex rings that wrap around it. STOVs constrain the intrapulse flow
of electromagnetic energy, controlling the focusing-defocusing cycles and pulse
splitting inherent to nonlinear pulse propagation. We illustrate this in two
widely studied but very different regimes, relativistic self-focusing in plasma
and non-relativistic self-focusing in gas, demonstrating that STOVs mediate
nonlinear propagation irrespective of the detailed physics
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