2,640 research outputs found
The role of recent experience and weight on hen's agonistic behaviour during dyadic conflict resolution.
Recent victory or defeat experiences and 2-hour familiarity with the meeting place were combined with size differences in order to better understand their effects on the behaviour leading to the establishment of dyadic dominance relationships between hens not previously acquainted with each other. Three kinds of encounters were videotaped: (i) a previous winner unfamiliar with the meeting place met a previous loser familiar for 2 hours with the meeting place (n = 12 dyads); (ii) as in (i) but both were unfamiliar with the meeting place (n=12); (iii) as in (i) but the previous winner was familiar with the meeting place while the previous loser was unfamiliar (n=13). The weight asymmetry was combined with these three types of encounters by selecting hens of various weight differences: in 29 dyads the recent loser was heavier than the recent winner and in 8 dyads it was the reverse. Recent experience had a major influence upon both agonistic behaviour and dominance outcome. Hens that were familiar with the meeting site initiated attacks more frequently than their unfamiliar opponent but did not win significantly more often. Recent experience and site familiarity could be used to identify 80% of future initiators. Once the first aggressive behaviour had been initiated, it led to victory of its initiator in 92% of cases. Weight was not found to influence agonistic behaviour nor dominance outcome. However, hens with superior comb and wattles areas won significantly more initial meetings than opponents with smaller ones. In the final encounters, victory also went more frequently to the bird showing larger comb and wattles, which happened also to be the previous dominant in a majority of cases. The use of higher-order partial correlations as an ex post facto control for comb and wattles indicates that they were not influential upon agonistic behaviour nor on dominance outcome, but were simply co-selected with the selection of victorious and defeated birds in the first phase of the experiment designed to let hens acquire recent victory/defeat experience
The role of hen's weight and recent experience on dyadic conflict outcome
This study simultaneously varied experiences of recent victory or defeat, 2-hour familiarity with the meeting place, and hen weight in order to understand their combined effects on the establishment of dyadic dominance relationships between hens not previously acquainted with each other. Three kinds of encounters were arranged: (i) a previous winner unfamiliar with the meeting place met a previous loser familiar with the meeting place (n =28 dyads); (ii) a previous winner met a previous loser, both unfamiliar with the meeting place (n=27); (iii) a previous winner familiar with the meeting place encountered a previous loser unfamiliar with the meeting place (n=28). The weight asymmetry was combined with these three types of encounters by selecting hens showing various weight differences, in favour of the recent loser in 54 dyads and of the recent winner in 29 dyads. Results indicate that recent victory or defeat experience significantly affected the outcome. Even an important weight asymmetry, or familiarity with the meeting place were not sufficient for a hen recently defeated to overcome an opponent that was previously victorious. A 2-hour period of familiarization with the meeting place did not provide any significant advantage over unfamiliarity. Although a significant relationship was found to exist between comb and wattles areas and the initial and final statuses, examination of partial correlations indicates that the influence was from initial status to final status, rather than from comb and wattles to final status. These results suggest that more importance should be attributed to recent social experience in comparison to intrinsic factors in determining dyadic dominance in the hen
Challenges in experimental data integration within genome-scale metabolic models
A report of the meeting "Challenges in experimental data integration within
genome-scale metabolic models", Institut Henri Poincar\'e, Paris, October 10-11
2009, organized by the CNRS-MPG joint program in Systems Biology.Comment: 5 page
The Cold and Hot Gas Content of Fine-Structure E and S0 Galaxies
We investigate trends of the cold and hot gas content of early-type galaxies
with the presence of optical morphological peculiarities, as measured by the
fine-structure index (Sigma). HI mapping observations from the literature are
used to track the cold-gas content, and archival ROSAT PSPC data are used to
quantify the hot-gas content. We find that E and S0 galaxies with a high
incidence of optical peculiarities are exclusively X-ray underluminous and,
therefore, deficient in hot gas. In contrast, more relaxed galaxies with little
or no signs of optical peculiarities span a wide range of X-ray luminosities.
That is, the X-ray excess anticorrelates with Sigma. There appears to be no
similar trend of cold-gas content with either fine-structure index or X-ray
content. The fact that only apparently relaxed E and S0 galaxies are strong
X-ray emitters is consistent with the hypothesis that after strong disturbances
such as a merger hot-gas halos build up over a time scale of several gigayears.
This is consistent with the expected mass loss from stars.Comment: 12 pages, latex, 5 figures. Accepted for publication in A
Master equation for collective spontaneous emission with quantized atomic motion
We derive a markovian master equation for the internal dynamics of an
ensemble of two-level atoms including all effects related to the quantization
of their motion. Our equation provides a unifying picture of the consequences
of recoil and indistinguishability of atoms beyond the Lamb-Dicke regime on
both their dissipative and conservative dynamics, and applies equally well to
distinguishable and indistinguishable atoms. We give general expressions for
the decay rates and the dipole-dipole shifts for any motional states, and we
find closed-form formulas for a number of relevant states (Gaussian states,
Fock states and thermal states). In particular, we show that dipole-dipole
interactions and cooperative photon emission can be modulated through the
external state of motion.Comment: 16 pages, 7 figures, minor correction
Abundance gradients in the Milky Way for alpha elements, Iron peak elements, Barium, Lanthanum and Europium
We model the abundance gradients in the disk of the Milky Way for several
chemical elements (O, Mg, Si, S, Ca, Sc, Ti, Co, V, Fe, Ni, Zn, Cu, Mn, Cr, Ba,
La and Eu), and compare our results with the most recent and homogeneous
observational data. We adopt a chemical evolution model able to well reproduce
the main properties of the solar vicinity. We compute, for the first time, the
abundance gradients for all the above mentioned elements in the galactocentric
distance range 4 - 22 kpc. The comparison with the observed data on Cepheids in
the galactocentric distance range 5-17 kpc gives a very good agreement for many
of the studied elements. In addition, we fit very well the data for the
evolution of Lanthanum in the solar vicinity for which we present results here
for the first time. We explore, also for the first time, the behaviour of the
abundance gradients at large galactocentric distances by comparing our results
with data relative to distant open clusters and red giants and select the best
chemical evolution model model on the basis of that. We find a very good fit to
the observed abundance gradients, as traced by Cepheids, for most of the
elements, thus confirming the validity of the inside-out scenario for the
formation of the Milky Way disk as well as the adopted nucleosynthesis
prescriptions.Comment: 11 pages, 9 figures, accepted for publication in A&
La sédimentation lacustre indicateur de changements des paléoenvironnements au cours des 30 000 dernières années (Carajas, Amazonie, Brésil)
Les résultats de l'analyse par spectrométrie infrarouge des échantillons de deux carottes prélevées dans deux dépressions marécageuses de la Serra Sul dos Carajas (Amazonie Orientale), mettent en évidence cinq grandes étapes paléohydrologiques au cours des 30 000 dernières années. La comparaison avec les résultats de la palynologie permet de mieux comprendre l'impact de changements climatiques brefs sur les paléoenvironnements. (Résumé d'auteur
Validation of Electronic Data Capture of the Irritable Bowel Syndrome—Quality of Life Measure, the Work Productivity and Activity Impairment Questionnaire for Irritable Bowel Syndrome and the EuroQol
ABSTRACTObjectivesTo assess the comparability, reliability, and subject acceptability of electronic data capture (EDC) versions of Irritable Bowel Syndrome—Quality of Life (IBS-QOL), EuroQoL (EQ-5D) and Work Productivity and Activity Impairment (WPAI:IBS) instruments.MethodsComparability of EDC and paper questionnaires was evaluated in 72 subjects with IBS who completed a baseline EDC or paper questionnaire, a crossover questionnaire 24 hours later, and a retest of the crossover version at 1 week. The EDC version was presented on a hand-held device. Comparability was assessed using paired t-test statistics, intraclass correlation coefficients (ICC) and tests for internal consistency (Cronbach's alpha).ResultsNo significant differences were found between scores obtained by paper questionnaire and EDC at the baseline and crossover assessments. ICCs between baseline and crossover assessments ranged from 0.83 to 0.96 for the IBS-QOL scores, 0.82 to 0.96 for the WPAI:IBS scores, and 0.77 to 0.82 for the EQ-5D. Internal consistency was comparable for the two data collection methods for the IBS-QOL overall score (0.96) and subscales and the EQ-5D Index (0.70 vs. 0.74). Retest statistics (ICC) were generally comparable between the EDC and paper versions for all scores. Ease of use was comparable for the two modes of administration, but more patients preferred EDC (47.2%) than the paper questionnaire (23.6%).ConclusionsEDC versions of the IBS-QOL, EQ-5D, and WPAI:IBS are comparable to paper questionnaires in internal consistency and test–retest reliability, and have greater patient acceptability
Evidence for validity and reliability of a french version of the FAAM
BACKGROUND: The Foot and Ankle Ability Measure (FAAM) is a self reported questionnaire for patients with foot and ankle disorders available in English, German, and Persian. This study plans to translate the FAAM from English to French (FAAM-F) and assess the validity and reliability of this new version.METHODS: The FAAM-F Activities of Daily Living (ADL) and sports subscales were completed by 105 French-speaking patients (average age 50.5 years) presenting various chronic foot and ankle disorders. Convergent and divergent validity was assessed by Pearson's correlation coefficients between the FAAM-F subscales and the SF-36 scales: Physical Functioning (PF), Physical Component Summary (PCS), Mental Health (MH) and Mental Component Summary (MCS). Internal consistency was calculated by Cronbach's Alpha (CA). To assess test re-test reliability, 22 patients filled out the questionnaire a second time to estimate minimal detectable changes (MDC) and intraclass correlation coefficients (ICC).RESULTS: Correlations for FAAM-F ADL subscale were 0.85 with PF, 0.81 with PCS, 0.26 with MH, 0.37 with MCS. Correlations for FAAM-F Sports subscale were 0.72 with PF, 0.72 with PCS, 0.21 with MH, 0.29 with MCS. CA estimates were 0.97 for both subscales. Respectively for the ADL and Sports subscales, ICC were 0.97 and 0.94, errors for a single measure were 8 and 10 points at 95% confidence and the MDC values at 95% confidence were 7 and 18 points.CONCLUSION: The FAAM-F is valid and reliable for the self-assessment of physical function in French-speaking patients with a wide range of chronic foot and ankle disorders
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