709 research outputs found
Nonuniversal Effects in the Homogeneous Bose Gas
Effective field theory predicts that the leading nonuniversal effects in the
homogeneous Bose gas arise from the effective range for S-wave scattering and
from an effective three-body contact interaction. We calculate the leading
nonuniversal contributions to the energy density and condensate fraction and
compare the predictions with results from diffusion Monte Carlo calculations by
Giorgini, Boronat, and Casulleras. We give a crude determination of the
strength of the three-body contact interaction for various model potentials.
Accurate determinations could be obtained from diffusion Monte Carlo
calculations of the energy density with higher statistics.Comment: 24 pages, RevTex, 5 ps figures, included with epsf.te
Combinaison de codeurs par algorithme génétique : Application à la vérification du locuteur
Le domaine de la vérification du locuteur regroupe les applications pour lesquelles on désire identifier l'identité d'une personne à partir de sa voix. Le champ d'application couvre de nombreux secteurs tels que l'accÚs sécurisé, les transactions téléphoniques, la surveillance, l'indexation audio ou encore l'expertise judiciaire. Notre étude porte sur l'étape d'extraction de caractéristiques du systÚme de reconnaissance du locuteur. Ce module a pour fonction d'extraire du signal de parole les informations pertinentes du point de vue de la discrimination inter-locuteur. Nous proposons dans cet article d'utiliser un algorithme génétique pour optimiser un systÚme d'extraction de caractéristiques adapté à la reconnaissance du locuteur. La méthode proposée permet d'obtenir une amélioration significative du taux de reconnaissance sur la base Nist SRE 2005
"The trauma of competition": the entry of Air Products Inc. into the industrial gases business in Britain and continental Europe 1947-1970
The British Oxygen Company (BOC) had a virtual monopoly on the supply of industrial gases (e.g. oxygen and acetylene) on the British market through the 1950s, when it was finally challenged by an American-based company, Air Products. Air Products Limited (APL) was able to undercut BOCs position, overcoming high barriers to entry to gain significant market share in this sector, which shares some features of network industries. Factors in this success included conditions imposed by the Board of Trade, APLâs innovations, BOCâs slow response, and favourable market conditions. APLâs success had implications for the internationalisation of the industrial gases industry
A computational study of grid erosion through ion impact
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77047/1/AIAA-2000-3664-398.pd
Evaluation of rK39 rapid diagnostic tests for canine visceral leishmaniasis : longitudinal study and meta-analysis
Canine visceral leishmaniasis is a vector-borne disease caused by the intracellular parasite Leishmania infantum. It is an important veterinary disease, and dogs are also the main animal reservoir for human infection. The disease is widespread in the Mediterranean area, and parts of Asia and South and Central America, and is potentially fatal in both dogs and humans unless treated. Diagnosis of canine infections requires serological or molecular tests. Detection of infection in dogs is important prior to treatment, and in epidemiological studies and control programmes, and a sensitive and specific rapid diagnostic test would be very useful. Rapid diagnostic tests (RDTs) have been developed, but their diagnostic performance has been reported to be variable. We evaluated the sensitivity of a RDT based on serological detection of the rK39 antigen in a cohort of naturally infected Brazilian dogs. The sensitivity of the test to detect infection was relatively low, but increased with time since infection and the severity of infection. We then carried out a meta-analysis of published studies of rK39 RDTs, evaluating the sensitivity to detect disease and infection. The results suggest that rK39 RDTs may be useful in a veterinary clinical setting, but the sensitivity to detect infection is too low for operational control programmes
An Investigation into the Mediating Influence of Customer Expertise on the Antecedents and Consequences of Affect within Professional Service Markets
This study examines the mediating influence of consumer expertise
on the antecedents and consequences of Affect within a professional services
market context. Whilst there is increasing evidence to suggest an empirical link
between Affect evoked and satisfaction within such contexts, previous research
has largely ignored the role of consumer expertise as a mediating influence.
Using a scenario based approach, the objective of the study was to test for multigroup
invariance among competing structural models based on the ability of
the respondents to form expectation and performance assessments about the
service they are receiving. The results indicate that it is important to examine
different levels of consumer expertise in detail to better understand how certain
characteristics such as experience and qualifications influence the priority and
functionality attached to service attributes when making satisfaction judgments
within a professional service context. This may in turn have broader implications
for our contextual understanding of services
Feeding spectra and activity of the freshwater crab Trichodactylus kensleyi (Decapoda: Brachyura: Trichodactylidae) at La Plata basin
Background: In inland water systems, it is important to characterize the trophic links in order to identify the âtrophic speciesâ and, from the studies of functional diversity, understand the dynamics of matter and energy in these environments. The aim of this study is to analyze the natural diet of Trichodactylus kensleyi of subtropical rainforest streams and corroborate the temporal variation in the trophic activity during day hours.
Results: A total of 15 major taxonomic groups were recognized in gut contents. The index of relative importance identified the following main prey items in decreasing order of importance: vegetal remains, oligochaetes, chironomid larvae, and algae. A significant difference was found in the amount of full stomachs during day hours showing a less trophic activity at midday and afternoon. The index of relative importance values evidenced the consumption of different prey according to day moments. Results of the gut content indicate that T. kensleyi is an omnivorous crab like other trichodactylid species. Opportunistic behavior is revealed by the ingestion of organisms abundant in streams such as oligochaetes and chironomid larvae. The consumption of allochthonous plant debris shows the importance of this crab as shredder in subtropical streams. However, the effective assimilation of plant matter is yet unknown in trichodactylid crabs.
Conclusions: This research provides knowledge that complements previous studies about trophic relationships of trichodactylid crabs and supported the importance of T. kensleyi in the transference of energy and matter from benthic community and riparian sources to superior trophic levels using both macro- and microfauna.Fil: Williner, VerĂłnica. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Santa Fe. Instituto Nacional de LimnologĂa. Universidad Nacional del Litoral. Instituto Nacional de LimnologĂa; Argentina. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias; ArgentinaFil: de Azevedo Carvalho, Debora. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Santa Fe. Instituto Nacional de LimnologĂa. Universidad Nacional del Litoral. Instituto Nacional de LimnologĂa; ArgentinaFil: Collins, Pablo Agustin. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Santa Fe. Instituto Nacional de LimnologĂa. Universidad Nacional del Litoral. Instituto Nacional de LimnologĂa; Argentina. Universidad Nacional del Litoral. Facultad de BioquĂmica y Ciencias BiolĂłgicas; Argentin
Nucleic Acids Res
Developmentally Regulated GTP-binding (DRG) proteins are highly conserved GTPases that associate with DRG Family Regulatory Proteins (DFRP). The resulting complexes have recently been shown to participate in eukaryotic translation. The structure of the Rbg1 GTPase, a yeast DRG protein, in complex with the C-terminal region of its DFRP partner, Tma46, was solved by X-ray diffraction. These data reveal that DRG proteins are multimodular factors with three additional domains, helix-turn-helix (HTH), S5D2L and TGS, packing against the GTPase platform. Surprisingly, the S5D2L domain is inserted in the middle of the GTPase sequence. In contrast, the region of Tma46 interacting with Rbg1 adopts an extended conformation typical of intrinsically unstructured proteins and contacts the GTPase and TGS domains. Functional analyses demonstrate that the various domains of Rbg1, as well as Tma46, modulate the GTPase activity of Rbg1 and contribute to the function of these proteins in vivo. Dissecting the role of the different domains revealed that the Rbg1 TGS domain is essential for the recruitment of this factor in polysomes, supporting further the implication of these conserved factors in translation
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