369 research outputs found

    Which mechanism underlies the water-like anomalies in core-softened potentials?

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    Using molecular dynamics simulations we investigate the thermodynamic of particles interacting with a continuous and a discrete versions of a core-softened (CS) intermolecular potential composed by a repulsive shoulder. Dynamic and structural properties are also analyzed by the simulations. We show that in the continuous version of the CS potential the density at constant pressure has a maximum for a certain temperature. Similarly the diffusion constant, DD, at a constant temperature has a maximum at a density ρmax\rho_{\mathrm{max}} and a minimum at a density ρmin<ρmax\rho_{\mathrm{min}}<\rho_{\mathrm{max}}, and structural properties are also anomalous. For the discrete CS potential none of these anomalies are observed. The absence of anomalies in the discrete case and its presence in the continuous CS potential are discussed in the framework of the excess entropy.Comment: 8 page

    Genetic Distance Based On Ssr And Grain Yield Of Inter And Intrapopulational Maize Single Cross Hybrids

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    The objective of this work was to correlate the genetic distances between the progenitors obtained by microsatellite markers with the grain yield of inter and intrapopulational maize single cross hybrids. Three S 0 populations derived from commercial single cross hybrids were used to obtain 163 hybrids (110 interpopulational and 53 intrapopulational). The two best hybrids and two worst hybrids of each the inter- and intrapopulational crosses were selected and their progenitors maintained through self-pollination of the second ear of each S 0 plant, genotyped with 47 SSRs. The Modified Roger's Distance (MRD) between each pair of S 1 inbred lines, the number of alleles and the polymorphic information content (PIC) of each primer were estimated. The genetic distances between progenitors were correlated with the grain yield of the inter- and intrapopulational hybrids. The number of obtained alleles was 186, with a mean of 3.96 alleles. The PIC varied from 0.49 to 0.80, with a mean of 0.65. The mean genetic distance between all S 1 inbred lines was 0.75, varying from 0.40 to 0.89, indicating the existence of variability between the S 1 inbred lines. The correlation between MRD and grain yield was high and significant for the interpopulational crosses (r = 0.84, P ≤ 0.01) and low and not significant (r = 0.18, P ≥ 0.05) for intrapopulational crosses.5103/04/15507513Ajmone Marsan, P., Castiglioni, P., Fu Sari, F., Kuiper, M., Motto, M., Genetic diversity and its relationship to hybrid performance in maize as revealed by RFLP and AFLP markers (1998) Theor. Appl. Genet., 96, pp. 219-227Árcade, A., Faivre-Rampant, P., Le Guerroué, B., Paques, L.E., Prat, D., Heterozigosity and hybrid performance in larch (1996) Theor. Appl. Genet., 93, pp. 1274-1281Barbosa, A.M.M., Geraldi, I.O., Benchimol, L.L., Garcia, A.A.F., Souza Jr., C.L., Souza, A.P., Relationship of intra and interpopulation tropical maize single cross hybrid performance and genetic distances computed from AFLP and SSR markers (2003) Euphytica, 87, pp. 87-99Benchimol, L.L., Souza Jr., C.L., Garcia, A.A.F., Kono, P.M.S., Mangolin, C.A., Barbosa, A.M.M., Coelho, A.S.G., Souza, A.P., Genetic diversity in tropical maize inbred lines: Heterotic group assignment and hybrid performance determined by RFLP markers (2000) Plant Breed., 119, pp. 491-496Boppenmaier, J., Melchinger, A.E., Brunklaus-Junt, E., Geiger, H.H., Genetic diversity for RFLP in European maize inbreds: Relation to performance of flint x dent crosses for forage traits (1992) Crop Sci., 32, pp. 895-902Butstein, D., White, M., Sholnick, M., David, R.W., Construction of a genetic linkage map in man using restriction fragment length polymorphisms (1980) Am. J. Hum. Genet., 32, pp. 314-331Cheres, M.T., Miller, J.F., Crane, J.M., Knapp, S.J., Genetic distance as a predictor of heterosis and hybrid performance within and between heterotic groups in sunflower (2000) Theor. Appl. Genet., 100, pp. 889-894Cruz, C.D., Shuster, I., (2004) GQMOL: Aplicativo Computacional para Análise de Dados Moleculares e de Suas Associações Com Caracteres Quantitativos. Versão 2004.2.1, , Viçosa. MGDhillon, B.S., Boppenmaier, J., Pollmer, R.G., Hermann, R.G., Melchinger, A.E., Relationship of restriction length polymorphisms among european maize inbreds with ear dry matter yield of their hybrids (1993) Maydica, 38, pp. 245-248Drinic, S.M., Trifunovic, S., Drinic, G., Konstantinov, K., Genetic divergence and its correlation to heterosis in maize as revealed by SSR base markers (2002) Maydica, 47, pp. 1-8Goodman, M.M., Stuber, C.W., Races of maize: VI. Isozyme variation among races of maize in Bolivia (1983) Maydica, 28, pp. 169-187Hallauer, A.R., Miranda Filho, J.B., (1988) Quantitative Genetics in Maize Breeding, 468p. , Iowa State University Press, AmesKruskal, J.B., Multidimensional scaling by optimizing goodness of fit to a no metric hypothesis (1964) Psychometrika, 29, pp. 1-27Lanza, L.L.B., Souza Jr., C.L., Ottoboni, I.M.M., Vieira, M.L.C., Souza, A.P., Genetic distance of inbred lines and prediction of maize single-cross performance using RAPD markers (1997) Theor. Appl. Genet., 94, pp. 1023-1030Le Clerc, V., Bazante, F., Baril, C., Guiard, J., Zhang, D., Assessing temporal changes in genetic diversity of maize varieties using microsatellite markers (2005) Theor. Appl. Genet., 110, pp. 294-302Lee, M., Godshalk, E.B., Lamkey, K.R., Woodman, W.W., Association of restriction fragment length polymorphisms among maize inbreds with agronomic performance of their crosses (1989) Crop Sci., 29, pp. 1067-1071Lu, H., Bernardo, R., Molecular marker diversity among current and historical maize inbreds (2001) Theor. Appl. Genet., 103, pp. 613-617Malécot, G., (1948) Les Mathématiques de l'Hérédite, , Masson et Cie, ParisMantel, N., The detection of disease clustering and a generalized regression approach (1967) Cancer Res., 37, pp. 209-220Melchinger, A.E., Genetic diversity and heterosis (1999) The Genetics and Exploitation of Heterosis in Crops, pp. 99-118. , J.G. Coors, S. Pandey (Eds.), Am. Soc. Agron. Madison WIMenkir, A., Melake-Berhan, A., Ingelbrecht, A.T., Adepoju, A., Grouping of tropical mid-altitude maize inbred lines on the basis of yield data and molecular markers (2004) Theor. Appl. Genet., 108, pp. 1582-1590Mille, M., (1997) TFPGA: Toll for Population Genetic Analysis, Version 1.3, , Northern Arizona UniversityPejic, I., Ajmone Marsan, P., Morgante, M., Kozumplick, V., Castiglioni, P., Taramino, G., Motto, M., Comparative analysis of genetic similarity among maize inbred lines detected by RFLPs, RAPDs, SSRs, and AFLPs (1998) Theor. Appl. 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Ed., 633p. , New York: McGraw HillVaz Patto, M.C., Satovic, Z., Pêgo, S., Fevereiro, P., Assessing the genetic diversity of Portuguese maize germoplasm using microsatellite markers (2004) Euphytica, 137, pp. 63-72Xia, X.C., Reif, J.C., Hoisington, D.A., Melchinger, A.E., Frisch, M., Warburton, M.L., Genetic diversity among CIMMYT maize inbred lines investigated with SSR markers (2004) Crop Sci., 44, pp. 2230-2237Xu, S., Liu, J., Liu, G., The use of SSRs for predicting the hybrid yield and yield heterosis in 15 key inbred lines of Chinese maize (2004) Hereditas, 141, pp. 207-21

    Dynamically Driven Renormalization Group Applied to Sandpile Models

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    The general framework for the renormalization group analysis of self-organized critical sandpile models is formulated. The usual real space renormalization scheme for lattice models when applied to nonequilibrium dynamical models must be supplemented by feedback relations coming from the stationarity conditions. On the basis of these ideas the Dynamically Driven Renormalization Group is applied to describe the boundary and bulk critical behavior of sandpile models. A detailed description of the branching nature of sandpile avalanches is given in terms of the generating functions of the underlying branching process.Comment: 18 RevTeX pages, 5 figure

    Gravitational field around a time-like current-carrying screwed cosmic string in scalar-tensor theories

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    In this paper we obtain the space-time generated by a time-like current-carrying superconducting screwed cosmic string(TCSCS). This gravitational field is obtained in a modified scalar-tensor theory in the sense that torsion is taken into account. We show that this solution is comptible with a torsion field generated by the scalar field ϕ\phi . The analysis of gravitational effects of a TCSCS shows up that the torsion effects that appear in the physical frame of Jordan-Fierz can be described in a geometric form given by contorsion term plus a symmetric part which contains the scalar gradient. As an important application of this solution, we consider the linear perturbation method developed by Zel'dovich, investigate the accretion of cold dark matter due to the formation of wakes when a TCSCS moves with speed vv and discuss the role played by torsion. Our results are compared with those obtained for cosmic strings in the framework of scalar-tensor theories without taking torsion into account.Comment: 21 pages, no figures, Revised Version, presented at the "XXIV- Encontro Nacional de Fisica de Particulas e Campos ", Caxambu, MG, Brazil, to appear in Phys. Rev.

    Schistosomiasis Mansoni In Urban Northeast Brazil: Influence Of Rainfall Regime On The Population Dynamics Of Biomphalaria Sp

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    Introduction: Our objective was to evaluate the infl uence of rainfall regime on the population dynamics of Biomphalaria in a potential urban focus of schistosomiasis in Aracaju, Brazil, during 2009-2010. Methods: Snails were collected monthly and were counted, measured and identifi ed; the level of infection and fecal contamination at the sampling sites was determined; rainfall data were obtained. Results: High levels of fecal contamination were observed, and the abundance of Biomphalaria glabrata increased during the rainy and post-rainy seasons. The snails' size was variable, and infected snails were identifi ed independently of rainfall. Conclusions: These results provide evidence of anthropogenic and climate interference in an urban focus of schistosomiasis in the Aracaju metropolitan area.465654657Pordeus, L.C., Aguiar, L.R., Quinino, L.R.M., Barbosa, C.S.A., Ocorrência das formas aguda e crônica da esquistossomose mansônica no Brasil no período de 1997 a 2006: Uma revisão de literatura (2008) Epidemiol Serv Saude, 17, pp. 163-175Souza, M.A.A., Barbosa, V.S., Wanderlei, T.N.G., Barbosa, C.S., Criadouros de Biomphalaria, temporários e permanentes, em Jaboatão dos Guararapes, PE (2008) Rev Soc Bras Med Trop, 41, pp. 252-256Araújo, K.C.G.M., Resendes, A.P.C., Souza-Santos, R., Silveira Jr., J.C., Barbosa, C.S., Análise espacial dos focos de Biomphalaria glabrata (Say, 1818) e de casos humanos de esquistossomose mansônica em Porto de Galinhas, Pernambuco, Brasil, no ano 2000 (2007) Cad Saude Publica, 23, pp. 409-417Lima, L.C., Família Planorbidae (1995) Tópicos em Malacologia Médica., pp. 90-112. , In: Barbosa FS, editor. Rio de Janeiro: Fundação Oswaldo Cruz(2005) Resolução CONAMA no 357, , http://www.cetesb.sp.gov.br/Agua/praias/res_conama_357_05.pdf, Conselho Nacional do Meio Ambiente (CONAMA). de 17 de março de. [Cited 2011 February 23]. Available fromSouza, M.A.A., Barbosa, V.S., Albuquerque, J.O., Bocanegra, S., Souza-Santos, R., Paredes, H., Aspectos ecológicos e levantamento malacológico para identificação de áreas de risco para transmissão da esquistossomose mansoni no litoral norte de Pernambuco, Brasil (2010) Iheringia Serie Zoológica, 100, pp. 19-24Barbosa, F.S., Barbosa, C.S., The bioecology of snails vectors for schistosomiasis in Brazil (1994) Cad Saude Publica, 10, pp. 200-209Fernandez, M.A., Thiengo, S.C., Susceptibility of Biomphalaria straminea from Peixe Angical dam, Tocantins, Brazil to infection with three strains of Schistosoma mansoni (2010) Mem Inst Oswaldo Cruz, 105, pp. 488-491Barbosa, C.S., Domingues, A.L.C., Abath, F., Montenegro, S.M.L., Guida, U., Carneiro, J., Epidemia de esquistossomose aguda na praia de Porto de Galinhas, Pernambuco, Brasil (2001) Cad Saude Publica, 17, pp. 725-728Rollemberg, C.V.V., Santos, C.M.B., Silva, M.M.B.L., Souza, A.M.B., Silva, A.M., Almeida, J.A.P., Aspectos epidemiológicos e distribuição geográfica da esquistossomose e geo-helmintos, no Estado de Sergipe, de acordo com os dados do Programa de Controle da Esquistossomose (2011) Rev Soc Bras Med Trop, 44, pp. 91-96Barbosa, C.S., Montenegro, S.M.L., Abath, F.G., Domingues, A.L.C., Eventos epidemiológicos relacionados à transmissão da esquistossomose em áreas rurais e urbanas de Pernambuco (2002) Mem Inst Oswaldo Cruz, 96, pp. 169-172Departamento de Vigilância Epidemiológica (2008) Vigilância e controle de moluscos de importância epidemiológica: Diretrizes técnicas., , Ministério da Saúde. Programa de Vigilância e Controle da Esquistossomose (PCE). 2nded. Brasília: Ministério da Saúd

    Cholesterol-functionalized carvedilol-loaded PLGA nanoparticles: anti-inflammatory, antioxidant, and antitumor effects

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    The inflammation has been identified as factor of tumor progression, which has increased the interest and use of molecules with anti-inflammatory and antioxidant activities in the cancer treatment. In this study, the antioxidant, anti-inflammatory, and antitumor potentials of carvedilol was explored in a different approach. The cholesterol (CHO) was investigated as facilitated agent in the action of carvedilol-loaded nanoparticles. Different formulations exhibited spherical and stable nanoparticle with mean diameter size < 250 nm. The cholesterol changed the copolymer-drug interactions and the encapsulation efficiency. The in vitro cancer study was performed using murine colorectal cancer cell line (CT-26) to observe the cell viability and apoptosis on MTS assay and flow cytometry, respectively. The experiments have demonstrated that cholesterol improved the performance of drug-loaded nanoparticles, which was much better than free drug. The in vivo inflammation peritonitis model revealed that carvedilol-loaded nanoparticles increased the level of glutathione and leukocyte migration mainly when the functionalized drug-loaded nanoparticles were tested, in a lower dose than the free drug. As hypothesized, the experimental data suggest that cholesterol-functionalized carvedilol-loaded PLGA nanoparticles can be a novel and promising approach in the inflammation-induced cancer therapy since showed anti-inflammatory, antioxidant, and antitumor effects.Graphical abstractRadiolog

    New Upper Limit of Terrestrial Equivalence Principle Test for Rotating Extended Bodies

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    Improved terrestrial experiment to test the equivalence principle for rotating extended bodies is presented, and a new upper limit for the violation of the equivalence principle is obtained at the level of 1.610-7% \times 10^{\text{-7}}, which is limited by the friction of the rotating gyroscope. It means the spin-gravity interaction between the extended bodies has not been observed at this level.Comment: 4 page

    Sensor Surface Design with NanoMaterials: A New Platform in the Diagnosis of COVID-19

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    Mass testing for COVID-19 is essential to defining patient management strategies, choosing the best clinical management, and dimensioning strategies for controlling viral dissemination and immunization strategies. Thus, it is of utmost importance to search for devices that allow a quick and reliable diagnosis of low cost that can be transposed from the bench to the bedside, such as biosensors. These devices can help choose the correct clinical management to minimize factors that lead to infected patients developing more severe diseases. The use of nanomaterials to modify biosensors’ surfaces to increase these devices’ sensitivity and their biofunctionality enables high-quality nanotechnological platforms. In addition to the diagnostic benefits, nanotechnological platforms that facilitate the monitoring of anti-SARS-CoV-2 antibodies may be the key to determining loss of protective immune response after an episode of COVID-19, which leads to a possible chance of reinfection, as well as how they can be used to assess and monitor the success of immunization strategies, which are beginning to be administered on a large scale and that the extent and duration of their protection will need to be determined. Therefore, in this chapter, we will cover nanomaterials’ use and their functionalities in the surface design of sensors, thus generating nanotechnological platforms in the various facets of the diagnosis of COVID-19
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