761 research outputs found
Transmission measurement at 10.6 microns of Te2As3Se5 rib-waveguides on As2S3 substrate
The feasibility of chalcogenide rib waveguides working at lambda = 10.6
microns has been demonstrated. The waveguides comprised a several microns thick
Te2As3Se5 film deposited by thermal evaporation on a polished As2S3 glass
substrate and further etched by physical etching in Ar or CF4/O2 atmosphere.
Output images at 10.6 microns and some propagation losses roughly estimated at
10dB/cm proved that the obtained structures behaved as channel waveguides with
a good lateral confinement of the light. The work opens the doors to the
realisation of components able to work in the mid and thermal infrared up to 20
microns and even more.Comment: The following article appeared in Vigreux-Bercovici et al., Appl.
Phys. Lett. 90, 011110 (2007) and may be found at
http://link.aip.org/link/?apl/90/01111
Taking SPARQL 1.1 extensions into account in the SWIP system
International audienceThe SWIP system aims at hiding the complexity of expressing a query in a graph query language such as SPARQL. We propose a mechanism by which a query expressed in natural language is translated into a SPARQL query. Our system analyses the sentence in order to exhibit concepts, instances and relations. Then it generates a query in an internal format called the pivot language. Finally, it selects pre-written query patterns and instantiates them with regard to the keywords of the initial query. These queries are presented by means of explicative natural language sentences among which the user can select the query he/she is actually interested in. We are currently focusing on new kinds of queries which are handled by the new version of our system, which is now based on the 1.1 version of SPARQL
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Delivery of Family-Based Treatment for Adolescent Anorexia Nervosa in a Public Health Care Setting: Research Versus Non-Research Specialty Care.
Comparing evidence-based psychotherapy (EBP) to usual care typically demonstrates the superiority of EBPs, although this has not been studied for eating disorders EBPs such as family-based treatment (FBT). The current study set out to examine weight outcomes for adolescents with anorexia nervosa who received FBT through a randomized clinical research trial (RCT, n = 54) or non-research specialty care (n = 56) at the same specialist pediatric eating disorder service. Weight was recorded throughout outpatient treatment (up to 18 sessions over 6 months), as well as at 6- and 12-month follow-up. Survival curves were used to examine time to weight restoration [greater than 95% median body mass index (mBMI)] as predicted by type of care (RCT vs. non-research specialty care), baseline clinical and demographic characteristics, and their potential interaction. Results did not indicate a significant main effect for type of care, but there was a significant effect for baseline weight (p = .03), such that weight restoration was achieved faster across both treatment types for those with a higher initial %mBMI. These data suggest that weight restoration achieved in non-research specialty care FBT was largely similar to that achieved in a controlled research trial. Clinical Trial Registration:http://www.anzctr.org.au/, identifier ACTRN12610000216011
Monitoring the Bi-Directional Relativistic Jets of the Radio Galaxy 1946+708
We report on a multi-frequency, multi-epoch campaign of Very Long Baseline
Interferometry observations of the radio galaxy 1946+708 using the VLBA and a
Global VLBI array. From these high-resolution observations we deduce the
kinematic age of the radio source to be 4000 years, comparable with the
ages of other Compact Symmetric Objects (CSOs). Ejections of pairs of jet
components appears to take place on time scales of 10 years and these
components in the jet travel outward at intrinsic velocities between 0.6 and
0.9 c. From the constraint that jet components cannot have intrinsic velocities
faster than light, we derive H_0 > 57 km s^-1 Mpc^-1 from the fastest pair of
components launched from the core. We provide strong evidence for the ejection
of a new pair of components in ~1997. From the trajectories of the jet
components we deduce that the jet is most likely to be helically confined,
rather than purely ballistic in nature.Comment: 20 pages, 8 figures, accepted to Ap
Rings and rigidity transitions in network glasses
Three elastic phases of covalent networks, (I) floppy, (II) isostatically
rigid and (III) stressed-rigid have now been identified in glasses at specific
degrees of cross-linking (or chemical composition) both in theory and
experiments. Here we use size-increasing cluster combinatorics and constraint
counting algorithms to study analytically possible consequences of
self-organization. In the presence of small rings that can be locally I, II or
III, we obtain two transitions instead of the previously reported single
percolative transition at the mean coordination number , one from a
floppy to an isostatic rigid phase, and a second one from an isostatic to a
stressed rigid phase. The width of the intermediate phase and the
order of the phase transitions depend on the nature of medium range order
(relative ring fractions). We compare the results to the Group IV
chalcogenides, such as Ge-Se and Si-Se, for which evidence of an intermediate
phase has been obtained, and for which estimates of ring fractions can be made
from structures of high T crystalline phases.Comment: 29 pages, revtex, 7 eps figure
Modeling Trap-Awareness and Related Phenomena in Capture-Recapture Studies
Trap-awareness and related phenomena whereby successive capture events are not independent is a feature of the majority of capture-recapture studies. This phenomenon was up to now difficult to incorporate in open population models and most authors have chosen to neglect it although this may have damaging consequences. Focusing on the situation where animals exhibit a trap response at the occasion immediately following one where they have been trapped but revert to their original naïve state if they are missed once, we show that trap-dependence is more naturally viewed as a state transition and is amenable to the current models of capture-recapture. This approach has the potential to accommodate lasting or progressively waning trap effects
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