1,597 research outputs found

    Exact Nonequilibrium Work Generating Function for a Small Classical System

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    We obtain the exact nonequilibrium work generating function (NEWGF), for a small system consisting of a massive Brownian particle connected to internal and external springs. The external work is provided to the system for a finite time interval. The Jarzynski equality (JE), obtained in this case directly from the NEWGF, is shown to be valid for the present model, in an exact way regardless of the rate of external work

    Ankyloglossia, Syndactyly and Polydactyly in the Pediatric Patient

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    Ankyloglossia is a congenital alteration in the development of the tongue characterized by the presence of a short or thick lingual frenulum, which leads to a limitation in its movements. There is an associative inconsistency between ankyloglossia and complications with breastfeeding, speech, swallowing, breathing, and the development of orofacial structures, and it is urgent to make more scientific research in this area. In the presence of polydactyly and syndactyly may be also present ankyloglossia. The purpose of this paper is to present two ankyloglossia cases with finger alterations, without a syndromic disease, and lead the medical team to research this topic and make an improved treatment plan for these cases.info:eu-repo/semantics/publishedVersio

    Ganho de fitomassa e acúmulo de N atmosférico em plantas de feijão-caupi inoculadas com rizóbio.

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    Este trabalho teve como objetivo verificar o ganho de matéria seca e o acúmulo de N na parte aérea de plantas de feijão-caupi [Vigna unguiculata (L.) Walp] inoculadas com estirpes de rizóbio específicas

    The impact of two-dimensional elastic disk

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    The impact of a two-dimensional elastic disk with a wall is numerically studied. It is clarified that the coefficient of restitution (COR) decreases with the impact velocity. The result is not consistent with the recent quasi-static theory of inelastic collisions even for very slow impact. The abrupt drop of COR is found due to the plastic deformation of the disk, which is assisted by the initial internal motion.(to be published in J. Phys. Soc. Jpn.)Comment: 6 Pages,2 figure

    Scaling properties of granular materials

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    Given an assembly of viscoelastic spheres with certain material properties, we raise the question how the macroscopic properties of the assembly will change if all lengths of the system, i.e. radii, container size etc., are scaled by a constant. The result leads to a method to scale down experiments to lab-size.Comment: 4 pages, 2 figure

    Avaliação do potencial de estirpes de rizóbio em fixar nitrogênio associadas ao feijão-caupi em Petrolina-PE.

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    O feijão-caupi é uma cultura leguminosa de grande importância para a alimentação humana, constituindo-se em uma fonte de proteína para a maioria da população rural. A eficiência de diferentes estirpes de rizóbio em fixar o nitrogênio atmosférico em associação com o feijão-caupi foi testada ao nível de campo na Estação Experimental da Caatinga, da Embrapa Semi-Árido, localizada no município de Petrolina-PE (09o23'S e 40o30'W, altitude: 350 m). O experimento foi implantado em condições de sequeiro, com delineamento de blocos ao acaso e seis repetições, constando de seis tratamentos, sendo quatro estirpes de rizóbio - BR 3267, BR 3299, BR 33o1 e BR 3302, uma dose de nitrogênio mineral - 50 kg ha-1 e uma testemunha. Aos trinta dias após o plantio, o número e peso seco de nódulos, peso de matéria seca e concentração de nitrogênio na parte aérea da planta foram determinados. Todas as estirpes superaram significativamente o tratamento testemunha, tanto em número como em peso seco de nódulos, denotando uma alta eficiência em nodular as raízes de feijão-caupi em relação às estirpes de rizóbio existentes no solo da área experimental

    On exact time-averages of a massive Poisson particle

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    In this work we study, under the Stratonovich definition, the problem of the damped oscillatory massive particle subject to a heterogeneous Poisson noise characterised by a rate of events, \lambda (t), and a magnitude, \Phi, following an exponential distribution. We tackle the problem by performing exact time-averages over the noise in a similar way to previous works analysing the problem of the Brownian particle. From this procedure we obtain the long-term equilibrium distributions of position and velocity as well as analytical asymptotic expressions for the injection and dissipation of energy terms. Considerations on the emergence of stochastic resonance in this type of system are also set forth.Comment: 21 pages, 5 figures. To be published in Journal of Statistical Mechanics: Theory and Experimen

    Prostaglandin E2-EP1 and EP2 receptor signaling promotes apical junctional complex disassembly of Caco-2 human colorectal cancer cells

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    <p>Abstract</p> <p>Background</p> <p>The apical junctional complex (AJC) is a dynamic structure responsible to maintain epithelial cell-cell adhesions and it plays important functions such as, polarity, mechanical integrity, and cell signaling. Alteration of this complex during pathological events leads to an impaired epithelial barrier by perturbation of the cell-cell adhesion system. Although clinical and experimental data indicate that prostaglandin E<sub>2 </sub>(PGE<sub>2</sub>) plays a critical function in promoting cell motility and cancer progression, little is known concerning its role in AJC disassembly, an event that takes place at the beginning of colorectal tumorigenesis. Using Caco-2 cells, a cell line derived from human colorectal cancer, we investigated the effects of prostaglandin E<sub>2 </sub>(PGE<sub>2</sub>) treatment on AJC assembly and function.</p> <p>Results</p> <p>Exposition of Caco-2 cells to PGE<sub>2 </sub>promoted differential alteration of AJC protein distribution, as evidenced by immunofluorescence and immunoblotting analysis and impairs the barrier function, as seen by a decrease in the transepithelial electric resistance and an increase in the permeability to ruthenium red marker. We demonstrated the involvement of EP1 and EP2 prostaglandin E<sub>2 </sub>receptor subtypes in the modulation of the AJC disassembly caused by prostanoid. Furthermore, pharmacological inhibition of protein kinase-C, but not PKA and p38MAPK significantly prevented the PGE<sub>2 </sub>effects on the AJC disassembly.</p> <p>Conclusion</p> <p>Our findings strongly suggest a central role of Prostaglandin E2-EP1 and EP2 receptor signaling to mediate AJC disassembly through a mechanism that involves PKC and claudin-1 as important target for the TJ-related effects in human colorectal cancer cells (Caco-2).</p

    Measuring labour mismatch in Europe

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    We calculate aggregate and comparable measures of mismatch in the labour market for 30 European countries. These indicators measure vertical mismatch (related to the level of education, e.g. overeducation, and undereducation) and horizontal mismatch (related to the field of education) and are comparable across countries and through time. In European countries, between 15 % to nearly 35 % of workers have a job for which they have more (or less) qualifications than the usual level. Approximately 20 % to nearly 50 % work in a job for which they do not have the usual field qualification. There is a great variability on mismatch across European labour markets. Undereducation affects more workers than overeducation in most European countries. Low correlations between mismatch and unemployment indicate that mismatch should be regarded as an additional informative variable, thus useful to characterize labour markets.info:eu-repo/semantics/acceptedVersio

    On Tackling the Limits of Resolution in SAT Solving

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    The practical success of Boolean Satisfiability (SAT) solvers stems from the CDCL (Conflict-Driven Clause Learning) approach to SAT solving. However, from a propositional proof complexity perspective, CDCL is no more powerful than the resolution proof system, for which many hard examples exist. This paper proposes a new problem transformation, which enables reducing the decision problem for formulas in conjunctive normal form (CNF) to the problem of solving maximum satisfiability over Horn formulas. Given the new transformation, the paper proves a polynomial bound on the number of MaxSAT resolution steps for pigeonhole formulas. This result is in clear contrast with earlier results on the length of proofs of MaxSAT resolution for pigeonhole formulas. The paper also establishes the same polynomial bound in the case of modern core-guided MaxSAT solvers. Experimental results, obtained on CNF formulas known to be hard for CDCL SAT solvers, show that these can be efficiently solved with modern MaxSAT solvers
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