2,864 research outputs found

    Experimental measurement of photothermal effect in Fabry-Perot cavities

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    We report the experimental observation of the photothermal effect. The measurements are performed by modulating the laser power absorbed by the mirrors of two high-finesse Fabry-Perot cavities. The results are very well described by a recently proposed theoretical model [M. Cerdonio, L. Conti, A. Heidmann and M. Pinard, Phys. Rev. D 63 (2001) 082003], confirming the correctness of such calculations. Our observations and quantitative characterization of the photothermal effect demonstrate its critical importance for high sensitivity interferometric displacement measurements, as those necessary for gravitational wave detection.Comment: 4 pages, 3 figures, submitted to Phys. Rev. Let

    The Parental Concerns Questionnaire: A Brief Screening Instrument for Potentially Severe Behavior Problems in Infants and Toddlers At-Risk for Developmental Delays

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    The Parental Concerns Questionnaire (PCQ) was designed as a parent-interview screening instrument for young children with developmental concerns at risk for potentially severe behavior problems (SBDs). Parents of 262 young children (4 to 48 months) answered to the 15 dichotomous PCQ items interviewed by trained staff. Cluster analysis for items revealed three item clusters, which we labeled Developmental/Social (8 items), Biomedical (3 items), and Behavior Problems (3 items). This paper discussed primarily the Behavior Problems cluster, with items referring to self-injurious, aggressive, and destructive behaviors. Parents' concerns about behavior problems were high, with item-endorsements of the Behavior Problems cluster ranging from 41.8 % to 68.8 %. The Behavior Problems cluster was significantly correlated with all three subscales of the Behavior Problems Inventory (BPI-01), with select subscales of the Aberrant Behavior Checklist (ABC), and with the Repetitive Behavior Scale-Revised (RBS-R) providing some evidence for concurrent validity. Sensitivity and specificity data were computed for the three PCQ items as well as for the cluster score in comparison with the BPI-01, ABC, and RBS-R showing strong sensitivity. The PCQ Behavior Problems cluster is a useful screening checklist with high sensitivity for potential SBDs in young children at-risk for developmental delays

    Sex‐biased disease dynamics increase extinction risk by impairing population recovery

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    The periodicity of life‐cycle events (phenology) modulates host availability to pathogens in a repeatable pattern. The effects of sexual differences in host phenology have been little explored in wildlife epidemiological studies. A recent series of ranavirosis outbreaks led to serious declines of Boscas’ newt populations at Serra da Estrela (Portugal). The peculiar phenology of this species, in which a large number of females remain in the aquatic habitat after the breeding season, turns it into a suitable model to test how sex‐biased mortality can affect host population persistence in the context of infectious diseases. We investigated how the phenology of Bosca's newt (i.e. biased number of females) mediated the impact of Ranavirus. We then evaluated the risk of extinction of the population under different scenarios of sex‐biased mortality using a population viability analysis. Two newt populations (one subject to yearly outbreaks and a comparative site where outbreaks have not been recorded) were tracked for trends over time following emergence of ranaviral disease, allowing us to assess the differential impact of the disease on both sexes. In addition to a significant decline in abundance of adult newts, our data suggest that phenology can affect disease dynamics indirectly, leading to reduction in females and a reversal of the sex ratio of the breeding population. Our models suggest that female‐biased mortality does not exacerbate Ranavirus‐driven population declines in the short‐term, but is likely to have a deleterious impact during the recovery process once the lethal effect of disease is removed from the system

    Rheumatoid arthritis, item response theory, Blom transformation, and mixed models

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    We studied rheumatoid arthritis (RA) in the North American Rheumatoid Arthritis Consortium (NARAC) data (1499 subjects; 757 families). Identical methods were applied for studying RA in the Genetic Analysis Workshop 15 (GAW15) simulated data (with a prior knowledge of the simulation answers). Fifty replications of GAW15 simulated data had 3497 ± 20 subjects in 1500 nuclear families. Two new statistical methods were applied to transform the original phenotypes on these data, the item response theory (IRT) to create a latent variable from nine classifying predictors and a Blom transformation of the anti-CCP (anti-cyclic citrinullated protein) variable. We performed linear mixed-effects (LME) models to study the additive associations of 404 Illumina-genotyped single-nucleotide polymorphisms (SNPs) on the NARAC data, and of 17,820 SNPs of the GAW15 simulated data. In the GAW15 simulated data, the association with anti-CCP Blom transformation showed a 100% sensitivity for SNP1 located in the major histocompatibility complex gene. In contrast, the association of SNP1 with the IRT latent variable showed only 24% sensitivity. From the simulated data, we conclude that the Blom transformation of the anti-CCP variable produced more reliable results than the latent variable from the qualitative combination of a group of RA risk factors. In the NARAC data, the significant RA-SNPs associations found with both phenotype-transformation methods provided a trend that may point toward dynein and energy control genes. Finer genotyping in the NARAC data would grant more exact evidence for the contributions of chromosome 6 to RA

    Inclusive charged and neutral particle multiplicity distributions in <i>χcJ</i> and <i>J/ψ</i> decays

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    Using a sample of 106 million ψ(3686) decays, ψ(3686)→γχcJ(J=0,1,2) and ψ(3686)→γχcJ,χcJ→γJ/ψ(J=1,2) events are utilized to study inclusive χcJ→anything, χcJ→hadrons, and J/ψ→anything distributions, including distributions of the number of charged tracks, electromagnetic calorimeter showers, and π0s, and to compare them with distributions obtained from the BESIII Monte Carlo simulation. Information from each Monte Carlo simulated decay event is used to construct matrices connecting the detected distributions to the input predetection "produced"distributions. Assuming these matrices also apply to data, they are used to predict the analogous produced distributions of the decay events. Using these, the charged particle multiplicities are compared with results from MARK I. Further, comparison of the distributions of the number of photons in data with those in Monte Carlo simulation indicates that G-parity conservation should be taken into consideration in the simulation

    Observation of the <i>Y</i>(4220) and <i>Y</i>(4390) in the process <i>e<sup>+</sup>e<sup>−</sup> → ηJ/ψ</i>

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    The cross sections of the process e+e−→ηJ/ψ at center-of-mass energies (√s) between 3.81 and 4.60 GeV are measured with high precision by using data samples collected with the BESIII detector operating at the BEPCII storage ring. Three structures are observed by analyzing the line shape of the measured cross sections, and a maximum-likelihood fit including three resonances is performed by assuming the lowest lying structure is the ψ(4040). For the other resonances, we obtain masses of (4218.6±3.8±2.5) and (4382.0±13.3±1.7)  MeV/c2 with corresponding widths of (82.0±5.7±0.4) and (135.8±60.8±22.5)  MeV, respectively, where the first uncertainties are statistical and the second ones systematic. The measured resonant parameters are consistent with those of the Y(4220) and Y(4390) from previous measurements of different final states. For the first time, we observe the decays of the Y(4220) and Y(4390) into ηJ/ψ final states

    Cross section measurement of e<sup>+</sup>e<sup>−</sup> → pp¯η and e<sup>+</sup>e<sup>−</sup> → pp¯ω at center-of-mass energies between 3.773 GeV and 4.6 GeV

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    Based on 14.7 fb-1 of e+e- annihilation data collected with the BESIII detector at the BEPCII collider at 17 different center-of-mass energies between 3.7730 GeV and 4.5995 GeV, Born cross sections of the two processes e+e-→pp¯η and e+e-→pp¯ω are measured for the first time. No indication of resonant production through a vector state V is observed, and upper limits on the Born cross sections of e+e-→V→pp¯η and e+e-→V→pp¯ω at the 90% confidence level are calculated for a large parameter space in resonance masses and widths. For the current world average parameters of the ψ(4230) of m=4.2187 GeV/c2 and Γ=44 MeV, we find upper limits on resonant production of the pp¯η and pp¯ω final states of 7.5 pb and 10.4 pb at the 90% CL, respectively

    Search for the decay <i>J/ψ → γ+</i> invisible

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    We search for J/ψ radiative decays into a weakly interacting neutral particle, namely an invisible particle, using the J/ψ produced through the process ψ(3686)→π+π-J/ψ in a data sample of (448.1±2.9)×106 ψ(3686) decays collected by the BESIII detector at BEPCII. No significant signal is observed. Using a modified frequentist method, upper limits on the branching fractions are set under different assumptions of invisible particle masses up to 12 GeV/c2. The upper limit corresponding to an invisible particle with zero mass is 7.0×10-7 at the 90% confidence level

    Observation of a structure in <i>e<sup>+</sup>e<sup>−</sup> → ϕη′</i> at <i>√s</i> from 2.05 to 3.08 GeV

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    The process e+e-→φη′ has been studied for the first time in detail using data sample collected with the BESIII detector at the BEPCII collider at center of mass energies from 2.05 to 3.08 GeV. A resonance with quantum numbers JPC=1 - is observed with mass M=(2177.5±4.8(stat)±19.5(syst))MeV/c2 and width Γ=(149.0±15.6(stat)±8.9(syst)) MeV with a statistical significance larger than 10σ, including systematic uncertainties. If the observed structure is identified with the φ(2170), then the ratio of partial width between the φη′ by BESIII and φη by BABAR is (ℬφηRΓeeR)/(ℬφη′RΓeeR)=0.23±0.10(stat)±0.18(syst), which is smaller than the prediction of the ss¯g hybrid models by several orders of magnitude
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