3,251 research outputs found

    The complete non-spinning effective-one-body metric at linear order in the mass ratio

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    Using the main result of a companion paper, in which the binding energy of a circular-orbit non-spinning compact binary system is computed at leading-order beyond the test-particle approximation, the exact expression of the effective-one-body (EOB) metric component g^eff_tt is obtained through first order in the mass ratio. Combining these results with the recent gravitational self-force calculation of the periastron advance for circular orbits in the Schwarzschild geometry, the EOB metric component g^eff_rr is also determined at linear order in the mass ratio. These results assume that the mapping between the real and effective Hamiltonians at the second and third post-Newtonian (PN) orders holds at all PN orders. Our findings also confirm the advantage of resumming the PN dynamics around the test-particle limit if the goal is to obtain a flexible model that can smoothly connect the test-mass and equal-mass limits.Comment: 11 pages, 2 figures; appendix generalized to include the logarithmic contributions in the post-Newtonian Hamiltonian. Results unchanged. Matches version to be published in Phys. Rev.

    Preeminent role of the Van Hove singularity in the strong-coupling analysis of scanning tunneling spectroscopy for two-dimensional cuprates

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    In two dimensions the non-interacting density of states displays a Van Hove singularity (VHS) which introduces an intrinsic electron-hole asymmetry, absent in three dimensions. We show that due to this VHS the strong-coupling analysis of tunneling spectra in high-TcT_c superconductors must be reconsidered. Based on a microscopic model which reproduces the experimental data with great accuracy, we elucidate the peculiar role played by the VHS in shaping the tunneling spectra, and show that more conventional analyses of strong-coupling effects can lead to severe errors.Comment: 5 pages, 4 figure

    Substance-tailored testing strategies in toxicology : an in silico methodology based on QSAR modeling of toxicological thresholds and Monte Carlo simulations of toxicological testing

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    International audienceThe design of toxicological testing strategies aimed at identifying the toxic effects of chemicals without (or with a minimal) recourse to animal experimentation is an important issue for toxicological regulations and for industrial decision-making. This article describes an original approach which enables the design of substance-tailored testing strategies with a specified performance in terms of false-positive and false-negative rates. The outcome of toxicological testing is simulated in a different way than previously published articles on the topic. Indeed, toxicological outcomes are simulated not only as a function of the performance of toxicological tests but also as a function of the physico-chemical Properties of chemicals. The required inputs for Our approach are QSAR predictions for the LOAELs of the toxicological effect of interest and statistical distributions describing the relationship existing between in vivo LOAEL values and results from in vitro tests. Our methodology is able to correctly predict the performance of testing strategies designed to analyze the teratogenic effects of two chemicals: di(2-ethylhexyl)phthalate and Indomethacin. The proposed decision-support methodology can be adapted to any toxicological context as long as a Statistical Comparison between in vitro and in Vivo results is possible and QSAR models for the toxicological effect of interest can be developed

    Inequality at Work: The Effect of Peer Salaries on Job Satisfaction

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    We use a simple theoretical framework and a randomized manipulation of access to information on peers' wages to provide new evidence on the effects of relative pay on individual job satisfaction and job search intentions. A randomly chosen subset of employees of the University of California (UC) was informed about a new website listing the pay of University employees. All employees were then surveyed about their job satisfaction and job search intentions. Our information treatment doubles the fraction of employees using the website, with the vast majority of new users accessing data on the pay of colleagues in their own department. We find an asymmetric response to the information treatment: workers with salaries below the median for their pay unit and occupation report lower pay and job satisfaction, while those earning above the median report no higher satisfaction. Likewise, below-median earners report a significant increase in the likelihood of looking for a new job, while above-median earners are unaffected. Our findings suggest that job satisfaction depends directly on relative pay comparisons, and that this relationship is non-linear.

    Malignant Versus Benign Tumors of the Sinonasal Cavity: A Case-Control Study on Occupational Etiology

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    Case-control studies on malignant sinonasal tumors and occupational risk factors are generally weakened by non-occupational confounders and the selection of suitable controls. This study aimed to confirm the association between sinonasal malignant tumors and patients' occupations with consideration for sinonasal inverted papillomas (SNIPs) as a control group. Thirty-two patients affected by adenocarcinoma (ADC) and 21 non-adenocarcinoma epithelial tumors (NAETs) were compared to 65 patients diagnosed with SNIPs. All patients were recruited in the same clinical setting between 2004 and 2016. A questionnaire was used to collect information on non-occupational factors (age, sex, smoking, allergies, and chronic sinusitis) and occupations (wood- and leather-related occupations, textile industry, metal working). Odds ratios (OR) with 95% confidence intervals (CI) associated with selected occupations were obtained by a multinomial and exact logistic regression. Between the three groups of patients, SNIP patients were significantly younger than ADC patients (p = 0.026). The risk of NAET increased in woodworkers (OR = 9.42; CI = 1.94\u207b45.6) and metal workers (OR = 5.65; CI = 1.12\u207b28.6). The risk of ADC increased in wood (OR = 86.3; CI = 15.2\u207b488) and leather workers (OR = 119.4; CI = 11.3\u207b1258). On the exact logistic regression, the OR associated to the textile industry was 9.32 (95%CI = 1.10\u207bInf) for ADC, and 7.21 (95%CI = 0.55\u207bInf) for NAET. Comparing sinonasal malignant tumors with controls recruited from the same clinical setting allowed demonstrating an increased risk associated with multiple occupations. Well-matched samples of cases and controls reduced the confounding bias and increased the strength of the association

    Gravitational Self-Force Correction to the Binding Energy of Compact Binary Systems

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    Using the first law of binary black-hole mechanics, we compute the binding energy E and total angular momentum J of two non-spinning compact objects moving on circular orbits with frequency Omega, at leading order beyond the test-particle approximation. By minimizing E(Omega) we recover the exact frequency shift of the Schwarzschild innermost stable circular orbit induced by the conservative piece of the gravitational self-force. Comparing our results for the coordinate invariant relation E(J) to those recently obtained from numerical simulations of comparable-mass non-spinning black-hole binaries, we find a remarkably good agreement, even in the strong-field regime. Our findings confirm that the domain of validity of perturbative calculations may extend well beyond the extreme mass-ratio limit.Comment: 5 pages, 1 figure; matches the published versio

    Mapping layperson medical terminology into the Human Phenotype Ontology using neural machine translation models

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    Supplementary material related to this article can be found online at https://doi.org/10.1016/j.eswa.2022.117446.In the medical domain there exists a terminological gap between patients and caregivers and the healthcare professionals. This gap may hinder the success of the communication between healthcare consumers and professionals in the field, with negative emotional and clinical consequences. In this work, we build a machine learning-based tool for the automatic translation between the terminology used by laypeople and that of the Human Phenotype Ontology (HPO). HPO is a structured vocabulary of phenotypic abnormalities found in human disease. Our method uses a vector space to represent an HPO-specific embedding as the output space for a neural network model trained on vector representations of layperson versions and other textual descriptors of medical terms. We explored different output embeddings coupled to different neural network architectures for the machine translation stage. We compute a similarity measure to evaluate the ability of the model to assign an HPO term to a layperson input. The best-performing models resulted with a similarity higher than 0.7 for more than 80% of the terms, with a median between 0.98 and 1. The translator model is made available in a web application at this link: https://hpotranslator.b2slab.upc.edu.This work was supported by the Spanish Ministry of Economy and Competitiveness (www.mineco.gob.es) TEC2014-60337-R, DPI2017-89827-R, Networking Biomedical Research Centre in the subject area of Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), initiatives of Instituto de Investigación Carlos III (ISCIII), and Share4Rare project (Grant Agreement 780262). This work was partially funded by ACCIÓ (Innotec ACE014/20/000018). B2SLab is certified as 2017 SGR 952. The authors thank the NVIDIA Corporation for the donation of a Titan Xp GPU used to run the models presented in this article. J. Fonollosa acknowledges the support from the Serra Húnter program.Peer ReviewedPostprint (published version

    Particle Size Distribution in a Godbert-Greenwald Furnace: Experiments and Modelling

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    During a dust dispersion, the particle size distribution (PSD) depends on several factors such as the turbulence, the initial particle size and shape as well as the dust concentration. As a consequence, when determining safety parameters using standard procedures, its potential evolution should be considered. Different powders were chosen: glucose, starch, ascorbic acid, glass beads and cellulose. A Godbert-Greenwald furnace was used to disperse the powders and determine their minimum ignition temperature (MIT) according to ISO/IEC 80079-20-2:2016 standard. The PSD of each powder was determined in-situ at different locations using a laser diffraction sensor. Some powders showed clear signs of breakage, as for glucose whose mean diameter decreases from 166 to 76 µm during its dispersion. On the contrary, many samples tended to agglomerate, e.g. starch and cellulose. For instance, the d90 of starch can even be quadrupled under certain conditions. Agglomeration occurs especially for fine dusts due to strong inter-particles forces (e.g. starch) or for elongated fibres due to entanglement phenomenon (e.g. cellulose). During a powder dispersion in the Godbert-Greenwald furnace, the PSD evolves not only as a function of time but also along with its location. The impact of the glass elbow on PSD variation has notably been highlighted by placing the G-G furnace horizontally. For powders showing strong tendency to agglomeration or breakage, the influence of the dispersion pressure has also been studied. The role of such PSD modification on the MIT has been measured and, depending on the dispersion procedure, temperature differences of more than 50°C have been observed. The agglomerate strength was assessed using three models (from Rumpf, Weiler and Kendall works) and compare to the deagglomeration stress exerted on the powders. In the case of cohesive powders, fibres or brittle dusts, attention should be paid to the PSD evolution during MIT determination

    Intoxicação experimental por amônia em bovinos que receberam uréia extrusada ou granulada: achados clínicos

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    Doze garrotes Girolando, nunca alimentados com uréia, foram distribuídos em dois grupos de seis animais cada. Ambos os grupos receberam intraruminalmente dose única (0,5 g/kg PV) de uréia extrusada (G1) ou granulada (G2), para induzir quadro de intoxicação por amônia. O quadro clínico exibido pelos garrotes foi acompanhado durante 240 minutos. Além da constatação dos sinais clínicos clássicos ligados a essa intoxicação, o presente trabalho descreve a presença de três novos sinais: desidratação, hipotermia e vasos episclerais ingurgitados. Convulsão, considerada sinal definitivo, ocorreu em cinco de seis animais de cada grupo. Um garrote (G1) exibiu apenas fasciculações, enquanto outro (G2) desenvolveu quadro clínico típico, porém sem convulsão, e recuperou-se espontaneamente sem tratamento. Os surgimentos de tremores musculares, decúbito esternal e episódios convulsivos ocorreram em momentos similares em ambos os grupos, mas quando analisados conjuntamente verificou-se que foram mais tardios no G1 (p < 0,04). O 1º sinal clínico observado foi a fasciculação, seguida por apatia, hiperestesia, apoio em obstáculos, tremores musculares, atonia ruminal, incoordenação motora, decúbito esternal e lateral, desidratação leve ou severa, e convulsão. Maiores freqüências cardíacas foram detectadas na convulsão. Após a convulsão, quatro garrotes de cada grupo apresentaram hipotermia leve. Um garrote do G2 entrou em estado comatoso e sucumbiu subitamente antes que fosse iniciado o tratamento. Apesar da uréia extrusada adiar o surgimento do quadro clínico, os sinais evidenciados foram tão severos quanto os causados por uréia granulada. Ambas formas de uréia, oferecidas em altas doses são perigosas a bovinos que nunca foram alimentados com uréia.Twelve yearling Girolando, rumen-fistulated steers never fed with urea before, were distributed randomly in 2 groups of 6 animals each. Both groups were administered intraruminally a single dose (0.5 g/kg BW) of extruded (G1) or prilled (G2) urea to induce ammonia poisoning. The clinical picture was followed for the next 240 min. Besides the classic signs the present study found 3 new additional sign: dehydration, hypothermia and ingurgitated episcleral veins. Convulsion, considered the definite sign, was seen in 5 out of 6 animals from both groups. One steer (G1) had only fasciculation, while another (G2) developed typical clinical signs, but not convulsion, and recovered spontaneously without treatment. The appearance of clinical signs such as muscle tremors, sternal recumbency and convulsive episode occurred at similar times in both groups, but when analyzed altogether they took place later in G1 (p < 0.04). The 1st sign to show up was fasciculation, followed by apathy, hyperaesthesia, pushing against obstacles, muscle tremor, rumen stasis, incoordination, sternal and then lateral recumbency, mild or severe dehydration, and convulsion. Higher heart rate was detected at the convulsive episodes. After the convulsions, 4 animals from each group had mild hypothermia. One steer from G2 fell down in coma and died suddenly before the beginning of the treatment. Although the extruded urea postponed the clinical picture, the signs were as severe as exhibited by cattle administered prilled urea. Both forms of urea offered at high dose can be harmful to cattle never fed urea
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