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A Geostatistical Approach to the Seasonal Precipitation Effect on Boro Rice Production in Bangladesh
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作者 Avit Kumar Bhowmik Ana Cristina Costa 《International Journal of Geosciences》 2012年第3期443-462,共20页
Geographical assessments on the relationship between climate variability and crop production are important for planning adaptation programs to climate change impacts on Asian rice production. This paper analyses the s... Geographical assessments on the relationship between climate variability and crop production are important for planning adaptation programs to climate change impacts on Asian rice production. This paper analyses the seasonal precipitation consequences to irrigated crop yields, in opposition to the idea that irrigated crop yields are not affected by precipitation changes. Geostatistical methods are applied to assess changes in the patterns of seasonal precipitation and corresponding changes in the Boro crop production in Bangladesh. Surfaces depicting changes in the monsoon, non-monsoon and total precipitation from 2006 to 2007, and changes in three varieties of Boro crop yield and Total Boro yield from 2006-2007 to 2007-2008 crop year are generated through Splines, Inverse Distance Weighting and Ordinary Kriging methods. Performance evaluation of these models is also performed. The relationships between the surfaces of different precipitation seasons and the surfaces of different Boro yield seasons are then assessed. The results show that there is a significant correlation between seasonal precipitation changes and Boro yield changes with notable correlation coefficients and similarity in the patterns. A significant conformity of the high precipitation zones to the high Boro yielding zones is also depicted. 展开更多
关键词 CLIMATE CROP Production INTERPOLATION KRIGING MONSOON
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Statistical Estimation of Surface Heat Control and Exchange in Endotherms
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作者 Barbara Henning Benilton de Sá Carvalho +2 位作者 José Luiz Boldrini Sérgio Furtado dos Reis Denis Otávio Vieira de Andrade 《Open Journal of Statistics》 2018年第1期220-239,共20页
In this paper, we combine polynomial functions, Generalized Estimating Equations, and bootstrap-based model selection to test for signatures of linear or nonlinear relationships between body surface temperature and am... In this paper, we combine polynomial functions, Generalized Estimating Equations, and bootstrap-based model selection to test for signatures of linear or nonlinear relationships between body surface temperature and ambient temperature in endotherms. Linearity or nonlinearity is associated with the absence or presence of cutaneous vasodilation and vasoconstriction, respectively. We obtained experimental data on body surface temperature variation from a mammalian model organism as a function of ambient temperature using infrared thermal imaging. The statistical framework of model estimation and selection successfully detected linear and nonlinear relationships between body surface temperature and ambient temperature for different body regions of the model organism. These results demonstrate that our statistical approach is instrumental to assess the complexity of thermoregulation in endotherms. 展开更多
关键词 Gracilinanus microtarsus Infrared THERMOGRAPHY Thermal Window THERMOREGULATION in Homeothermic ENDOTHERMS VASOMOTOR Adjustment
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Challenges in Implementing DVI Best Practice Guidelines Due to the Brumadinho Disaster
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作者 Reinaldo Moreira Silva Bruno Diniz Sander Morais +11 位作者 Carlos Danilo Ruas Silva Elza Cristina Lopes de Oliveira Fernando Pereira Macedo Giovanni Vitral Pinto Guadalupe Dell’Arret Coutinho Higgor Gonçalves Dornelas João Luiz Silva Moreira Laila Evangelista de Almeida Fernandes Marcia Lobão Iannini Patrícia Siqueira Valéria Rosalina Dias e Santos Sordaini Maria Caligiorne 《Forensic Medicine and Anatomy Research》 2024年第1期1-12,共12页
The broke of a tailings dam from Vale S.A. destroyed a gigantic area killing 270 persons in Brumadinho/Brazil. Organizing activities after a mass disaster is a complex process that requires the involvement of many peo... The broke of a tailings dam from Vale S.A. destroyed a gigantic area killing 270 persons in Brumadinho/Brazil. Organizing activities after a mass disaster is a complex process that requires the involvement of many people and resources in the laboratory. To DNA identification of the victims, a daunting work had to be made by DNA laboratory staff in a collaborative effort with many partners. Efforts to implement good practice guidelines in Disaster Victim Identification (DVI) have revealed several important aspects that need to change in the forensic DNA laboratory. This article highlights the challenges of implementing DVI best practice guidelines in resource-poor settings, but with professionals from different sectors engaged in the same goal of briefly identifying victims and helping families and society. 展开更多
关键词 DISASTER VICTIM Identification DNA Brumadinho
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Designing Pair of Nonlinear Components of a Block Cipher over Gaussian Integers 被引量:1
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作者 Muhammad Sajjad Tariq Shah Robinson Julian Serna 《Computers, Materials & Continua》 SCIE EI 2023年第6期5287-5305,共19页
In block ciphers,the nonlinear components,also known as sub-stitution boxes(S-boxes),are used with the purpose of inducing confusion in cryptosystems.For the last decade,most of the work on designing S-boxes over the ... In block ciphers,the nonlinear components,also known as sub-stitution boxes(S-boxes),are used with the purpose of inducing confusion in cryptosystems.For the last decade,most of the work on designing S-boxes over the points of elliptic curves has been published.The main purpose of these studies is to hide data and improve the security levels of crypto algorithms.In this work,we design pair of nonlinear components of a block cipher over the residue class of Gaussian integers(GI).The fascinating features of this structure provide S-boxes pair at a time by fixing three parameters.But the prime field dependent on the Elliptic curve(EC)provides one S-box at a time by fixing three parameters a,b,and p.The newly designed pair of S-boxes are assessed by various tests like nonlinearity,bit independence criterion,strict avalanche criterion,linear approximation probability,and differential approximation probability. 展开更多
关键词 Gaussian integers residue class of gaussian integers block cipher S-boxes analysis of S-boxes
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Goodness-of-Fit Test for Non-Stationary and Strongly Dependent Samples
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作者 Carolina Crisci Gonzalo Perera Lia Sampognaro 《Advances in Pure Mathematics》 2023年第5期226-236,共11页
In this article we improve a goodness-of-fit test, of the Kolmogorov-Smirnov type, for equally distributed- but not stationary-strongly dependent data. The test is based on the asymptotic behavior of the empirical pro... In this article we improve a goodness-of-fit test, of the Kolmogorov-Smirnov type, for equally distributed- but not stationary-strongly dependent data. The test is based on the asymptotic behavior of the empirical process, which is much more complex than in the classical case. Applications to simulated data and discussion of the obtained results are provided. This is, to the best of our knowledge, the first result providing a general goodness of fit test for non-weakly dependent data. 展开更多
关键词 Kolmogorov-Smirnov Test Strongly Dependent Data Asymptotic Behavior of Empirical Processes
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Estimating the Components of a Mixture of Extremal Distributions under Strong Dependence
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作者 Carolina Crisci Gonzalo Perera Lia Sampognaro 《Advances in Pure Mathematics》 2023年第7期425-441,共17页
In this paper, we provide a method based on quantiles to estimate the parameters of a finite mixture of Fréchet distributions, for a large sample of strongly dependent data. This is a situation that appears when ... In this paper, we provide a method based on quantiles to estimate the parameters of a finite mixture of Fréchet distributions, for a large sample of strongly dependent data. This is a situation that appears when dealing with environmental data and there was a real need of such method. We validate our approach by means of estimation and goodness-of-fit testing over simulated data, showing an accurate performance. 展开更多
关键词 Mixture of Extremal Distributions Strongly Dependent Data
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Structural Analysis of TiC and TiC-C Core-Shell Nanostructures Produced by Pulsed-Laser Ablation
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作者 Luis Enrique Iniesta Piña Miguel Ángel Camacho López +2 位作者 Rafael Vilchis Néstor Víctor Hugo Castrejón Sánchez Delfino Reyes Contreras 《Journal of Materials Science and Chemical Engineering》 2023年第7期1-13,共13页
This paper reports on the ablation process of a pure Ti solid target immersed in a C-enriched acetone solution, leading to the production of titanium carbide (TiC) and Ti-C core-shell nanostructures. The used route of... This paper reports on the ablation process of a pure Ti solid target immersed in a C-enriched acetone solution, leading to the production of titanium carbide (TiC) and Ti-C core-shell nanostructures. The used route of synthesis is generally called pulsed laser ablation in liquid (PLAL). The presence of carbon structures in the solution contributed to the carbon content in the produced Ti-based nanomaterials. The atomic composition of the produced nanostructures was analyzed using SEM-EDS, while TEM micrographs revealed the formation of spherical TiC and core-shell nanostructures ranging from 40 to 100 nm. The identification of atomic planes by HRTEM confirmed a 10 nm diameter C-shell with a graphite structure surrounding the Ti-core. Raman spectroscopy allowed for the identification of D and G peaks for graphite and a Raman signal at 380 and 600 cm<sup>−1</sup>, assigned to TiC. The results contribute to the state-of-the-art production of TiC and Ti-C core-shell nanostructures using the PLAL route. 展开更多
关键词 Laser Ablation TIC NANOPARTICLES Core-Shell Nanoparticles Pulsed Laser
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Variational Calculus With Conformable Fractional Derivatives 被引量:4
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作者 Matheus J.Lazo Delfim F.M.Torres 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2017年第2期340-352,共13页
Invariant conditions for conformable fractional problems of the calculus of variations under the presence of external forces in the dynamics are studied. Depending on the type of transformations considered, different ... Invariant conditions for conformable fractional problems of the calculus of variations under the presence of external forces in the dynamics are studied. Depending on the type of transformations considered, different necessary conditions of invariance are obtained. As particular cases, we prove fractional versions of Noether's symmetry theorem. Invariant conditions for fractional optimal control problems, using the Hamiltonian formalism, are also investigated. As an example of potential application in Physics, we show that with conformable derivatives it is possible to formulate an Action Principle for particles under frictional forces that is far simpler than the one obtained with classical fractional derivatives. 展开更多
关键词 Conformable fractional derivative fractional calculus of variations fractional optimal control invariant variational conditions Noether’s theorem
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Immediate effect of high-intensity exercise on brain-derived neurotrophic factor in healthy young adults:A systematic review and meta-analysis 被引量:2
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作者 Rubén Fernández-Rodríguez CeliaÁlvarez-Bueno +3 位作者 Isabel A.Martínez-Ortega Vicente Martínez-Vizcaíno Arthur Eumann Mesas Blanca Notario-Pacheco 《Journal of Sport and Health Science》 SCIE 2022年第3期367-375,共9页
Background Although brain-derived neurotrophic factor(BDNF)has been identified as a molecular biomarker of the neurophysiological effects induced by exercise,the acute effects of high-intensity exercise(HIE)on BDNF le... Background Although brain-derived neurotrophic factor(BDNF)has been identified as a molecular biomarker of the neurophysiological effects induced by exercise,the acute effects of high-intensity exercise(HIE)on BDNF levels are inconclusive.This study aims to estimate the immediate effects of HIE on BDNF levels in healthy young adults.Methods A systematic search was conducted in the MEDLINE,Scopus,Cochrane CENTRAL,and SPORTDiscuss databases up to December 2020.Randomized controlled trials(RCTs)and non-RCTs reporting pre-post changes in serum or plasma BDNF after an acute intervention of HIE compared to a control condition were included.Pooled effect sizes(p-ESs)and 95%confidence intervals(95%CIs)were calculated for RCTs using a random effects model with Stata/SE(Version 15.0;StataCorp.,College Station,TX,USA).The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed.PROPERO registration number:CRD42020221047.Results A total of 22 studies with 552 individuals(age range:20-31 years;59.1%male)were included.The meta-analysis included 10 RCTs that reported valid outcome data.Higher BDNF levels were observed when HIE interventions were compared with non-exercise(p-ES=0.55,95%CI:0.12-0.98;I^(2)=25.7%;n=4 studies)and light-intensity exercise(p-ES=0.78,95%CI:0.15-1.40;I^(2)=52.4%;n=3 studies)but not moderate-intensity exercise(p-ES=0.93,95%CI:-0.16 to 2.02;I^(2)=88.5%;n=4 studies)conditions.Conclusion In comparison to non-exercise or light-intensity exercises,an immediate increase in BDNF levels may occur when young adults perform HIE.Given the benefits obtained maximizing circulating BDNF when performing HIE and its potential effects on brain health,our findings suggest that HIE could be recommended by clinicians as a useful exercise strategy to healthy adults. 展开更多
关键词 COGNITION EXERCISE NEUROGENESIS NEUROPLASTICITY
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压缩式驱动器主观音质评价方法的比较
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作者 José Martínez Joan Cruaes +2 位作者 Jorge Francés Monllor Jaime Ramis 钟波 《电声技术》 2011年第3期37-41,共5页
提出了一种基于感知模型的声辐射系统音质评价方法。采用此模型可应用Moore提出的参数以测试其是否适用于间接辐射扬声器的音质评价。对3种压缩式驱动器进行了测试,并且记录了它们在各种测试信号以及各种输入电压条件下的测试结果。基... 提出了一种基于感知模型的声辐射系统音质评价方法。采用此模型可应用Moore提出的参数以测试其是否适用于间接辐射扬声器的音质评价。对3种压缩式驱动器进行了测试,并且记录了它们在各种测试信号以及各种输入电压条件下的测试结果。基于上述实验结果,从不同的角度提出了解决该问题的方法:(a)考虑经典的音质评价参数,如粗糙度、尖锐度和音调;(b)应用由Moore建议的从感知模型获取的参数。此外,还进行了一项针对25人的心理声学实验,尽管实验结果只是初步的并极大依赖于参考信号,但仍然能够表明其与Rnonlin值的良好相关性。 展开更多
关键词 压缩式驱动器 主观评价 音质 感知模型
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Dynamic Modelling of Dengue Epidemics in Function of Available Enthalpy and Rainfall 被引量:2
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作者 Hugo Abi Karam Julio Cesar Barreto da Silva +1 位作者 Augusto José Pereira Filho José Luis Flores Rojas 《Open Journal of Epidemiology》 2016年第1期50-79,共30页
In this work, we present results of an investigation of environmental precursors of infectious epidemic of dengue fever in the Metropolitan Area of Rio de Janeiro, RJ, Brazil, obtained by a numerical model with repres... In this work, we present results of an investigation of environmental precursors of infectious epidemic of dengue fever in the Metropolitan Area of Rio de Janeiro, RJ, Brazil, obtained by a numerical model with representation of infection and reinfection of the population. The period considered extend between 2000 and 2011, in which it was possible to pair meteorological data and the reporting of dengue patients worsening. These data should also be considered in the numerical model, by assimilation, to obtain simulations of Dengue epidemics. The model contains compartments for the human population, for the vector Aedes aegypti and four virus serotypes. The results provide consistent evidence that worsening infection and disease outbreaks are due to the occurrence of environmental precursors, as the dynamics of the accumulation of water in the breeding and energy availability in the form of metabolic activation enthalpy during pre-epidemic periods. 展开更多
关键词 Modelling Dengue Epidemics Environmental Enthalpy Environmental Precursors of Dengue Epidemics
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Segmentation of MS lesions using entropy-based EM algorithm and Markov random fields 被引量:1
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作者 Ahmad Bijar Mahdi Mohamad Khanloo +1 位作者 Antonio Penalver Benavent Rasoul Khayati 《Journal of Biomedical Science and Engineering》 2011年第8期552-561,共10页
This paper presents an approach for fully automatic segmentation of MS lesions in fluid attenuated inversion recovery (FLAIR) Magnetic Resonance (MR) images. The proposed method estimates a gaussian mixture model with... This paper presents an approach for fully automatic segmentation of MS lesions in fluid attenuated inversion recovery (FLAIR) Magnetic Resonance (MR) images. The proposed method estimates a gaussian mixture model with three kernels as cerebrospinal fluid (CSF), normal tissue and Multiple Sclerosis lesions. To estimate this model, an automatic Entropy based EM algorithm is used to find the best estimated Model. Then, Markov random field (MRF) model and EM algorithm are utilized to obtain and upgrade the class conditional probability density function and the apriori probability of each class. After estimation of Model parameters and apriori probability, brain tissues are classified using bayesian classification. To evaluate the result of the proposed method, similarity criteria of different slices related to 20 MS patients are calculated and compared with other methods which include manual segmentation. Also, volume of segmented lesions are computed and compared with gold standard using correlation coefficient. The proposed method has better performance in comparison with previous works which are reported here. 展开更多
关键词 Gaussian Mixture Model EM ENTROPY Markov Random Field Multiple Sclerosis
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Oscillating Statistics of Transitive Dynamics
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作者 Eleonora Catsigeras 《Advances in Pure Mathematics》 2015年第9期534-543,共10页
We prove that topologically generic orbits of C0 , transitive and non-uniquely ergodic dynamical systems, exhibit an extremely oscillating asymptotical statistics. Precisely, the minimum weak* compact set of invariant... We prove that topologically generic orbits of C0 , transitive and non-uniquely ergodic dynamical systems, exhibit an extremely oscillating asymptotical statistics. Precisely, the minimum weak* compact set of invariant probabilities that describes the asymptotical statistics of each orbit of a residual set contains all the ergodic probabilities. If besides f is ergodic with respect to the Lebesgue measure, then also Lebesgue-almost all the orbits exhibit that kind of extremely oscillating statistics. 展开更多
关键词 Measure PRESERVING Maps Dynamical Systems ERGODIC Theory ASYMPTOTIC STATISTICS
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Breast Reconstruction: Does It Worth to Start If the Patient Is Not Sure to Take All the Process Along?
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作者 Jesús Ricardo García-Corral José Martínez-Lopez +16 位作者 Rodrigo Davila-Diaz Blanca Arambula-Sanchez Marco Cuervo-Vergara Fernando Barbosa-Villarreal Daniel De Luna Ana Priscila Campollo Lopez Fernando Isaac Recio Espana Alfredo Chama Naranjo Jaime García Alejandro Costa David Flores-Soto Selina Marioni-Manriquez Patricia Lopez-Medellin Erika Barlandas-Quintana Edgar Guillen-Martinez Steve Rodriguez-Alanis Cuahutemoc Marquez 《Journal of Biosciences and Medicines》 CAS 2022年第8期201-209,共9页
Introduction: Breast cancer is the most common cancer in women worldwide, representing a major public health problem. There is still little information comparing the satisfaction of the patients who finished their pro... Introduction: Breast cancer is the most common cancer in women worldwide, representing a major public health problem. There is still little information comparing the satisfaction of the patients who finished their process against the ones who start it but did not finish it. The aim of our retrospective study was to analyze the results in terms of satisfaction after one year of undergoing to complete breast reconstruction (CBR) vs incomplete breast reconstruction (IBR). Materials and Methods: Retrospective study of patients that underwent breast reconstruction (BR) surgery after mastectomy for breast cancer treatment. Performed at Hospital Central Sur de Alta Especialidad PEMEX in Mexico City, including patients from January 1, 2015 to January 01, 2020. Demographic baseline variables were included. BREAST-Q satisfaction questionnaires one year after the last reconstructive procedure were analyzed. Results: A total of 44 patients fulfilled the inclusion criteria. Of these 44 patients, 11 were included in the IBR group, and 33 patients in the CBR group. There were no statistically significant differences between the two groups in terms of age (IBR 56.09 vs CBR 53.06 years, p = 0.321);BMI (IBR 27.94 vs CBR 26.40, p = 0.253), time from mastectomy to first reconstructive procedure (IBR 22.8 vs CBR 31 months, p = 0.957), history of chemotherapy (IBR 27.3% vs CBR 33.3%, p = 0.709) and radiotherapy (IBR 54.5% vs CBR 42.4%, p = 0.484), additionally type of reconstruction, affected side or complication rate were not significantly different. Regarding postoperative satisfaction, only the second module of satisfaction with breasts displayed statistically significant differences, with a higher score in the CBR group (46.27 vs 52.27, p = 0.019). Other items explored didn’t show significant differences. Discussion: The data reported in this study suggest that regardless of whether the last stage of a BR is reached, the results in these settings can be very similar in terms of psychosocial well-being, sexual well-being, physical well-being regarding the chest area, with some degree of better perception of her breasts. Conclusion: This study suggests that the results in terms of satisfaction in BR after mastectomy for breast cancer are quite similar for patients who decide to take only the first reconstructive stage, compared with those that finished all the process along, this may be a valuable tool for decision making. 展开更多
关键词 BREAST-Q Breast Reconstruction Satisfaction Index Quality of Life Breast Cancer Patient’s Decision Making
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EXISTENCE OF SOLUTIONS OF nTH-ORDER NONLINEAR DIFFERENCE EQUATIONS WITH GENERAL BOUNDARY CONDITIONS
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作者 Alberto CABADA Nikolay DIMITROV 《Acta Mathematica Scientia》 SCIE CSCD 2020年第1期226-236,共11页
The aim of this paper is to prove the existence of one or multiple solutions of nonlinear difference equations coupled to a general set of boundary conditions.Before to do this,we construct a discrete operator whose f... The aim of this paper is to prove the existence of one or multiple solutions of nonlinear difference equations coupled to a general set of boundary conditions.Before to do this,we construct a discrete operator whose fixed points coincide with the solutions of the problem we are looking for.Moreover,we introduce a strong positiveness condition on the related Green's function that allows us to construct suitable cones where to apply adequate fixed point theorems.Once we have the general existence result,we deduce,as a particular case,the existence of solutions of a second order difference equation with nonlocal perturbed Dirichlet conditions. 展开更多
关键词 DIFFERENCE equation MULTIPLICITY of SOLUTIONS Green's function POSITIVE SOLUTIONS parameter DEPENDENCE
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ASYMPTOTIC HOMOGENIZATION IN A PARABOLIC SEMILINEAR PROBLEM WITH PERIODIC COEFFICIENTS AND INTEGRABLE INITIAL DATA
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作者 Rogerio Luiz Quintino de OLIVEIRA JUNIOR 《Acta Mathematica Scientia》 SCIE CSCD 2013年第5期1275-1292,共18页
In this paper, we study the large time behavior of solutions of the parabolic semilinear equation δtu-div(a(x)△↓u) = -|u|^αu in (0,∞) × R^N, where α 〉 0 is constant and a∈ Cb^1(R^N) is a symmetr... In this paper, we study the large time behavior of solutions of the parabolic semilinear equation δtu-div(a(x)△↓u) = -|u|^αu in (0,∞) × R^N, where α 〉 0 is constant and a∈ Cb^1(R^N) is a symmetric periodic matrix satisfying some ellipticity assumptions.Considering an integrable initial data u0 and α ∈ (2/N, 3/N), we prove that the large time behavior of solutions is given by the solution U(t, x) of the homogenized linear problem δtU-div(a^h△↓U)=0,U(0) = C, where a^h is the homogenized matrix of a(x), C is a positive constant and δ is the Dirac measure at 0. 展开更多
关键词 HOMOGENIZATION similinear parabolic equation integrable initial data matrix with periodic coefficient large time behavior
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Genetic Diversity of Great Dane Breed Using Ten Microsatellites: Impact of Breeding Control over the Breeding Line 被引量:1
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作者 Gino Noris Carla Santana +8 位作者 Mariana Herrán-Aguirre Marco Antonio Meraz-Ríos Mario Pérez-Martínez Carlos Esquivel-Lacroix Leonor C. Acosta-Saavedra Eduardo Rodríguez María de la Paz Juaréz Emma S. Calderón-Aranda Rocío Gómez 《Open Journal of Genetics》 2014年第2期78-86,共9页
The American Kennel Club and the Fédération Cynologique Internationale recognize two phenotypic variants of Great Dane breed denominated American and European varieties. Historically, these varieties have be... The American Kennel Club and the Fédération Cynologique Internationale recognize two phenotypic variants of Great Dane breed denominated American and European varieties. Historically, these varieties have been segregated according to morphological characteristics. In an attempt to obtain a better characterization, breeders have been interested in the genetic parameters that could evaluate the within-breed diversity. In this document, we studied the genetic structure of Great Dane breed with 10 STR markers in 88 dogs using capillary electrophoresis. Cluster analysis, population differentiation and phylogenetic analyses revealed that American and European varieties are genetically independent. Nevertheless, within the American variety a genetic stratification was found. Additionally, a high misclassification (28%) was detected, which could be due to wrong registration or false paternity. Our results support the importance to deem genetic markers as useful tools in breeding control. Similarly, these studies serve as an accurate reference to establish standards by dog breeding associations and for choosing among dogs for inter-breeding. Nevertheless, genetic tools are only a complement of morphological methods, since both are reshuffling the control over the breeding line. Notwithstanding, this database provides an overall and scape concerning the impact of genetic diversity within-breed. Unmistakably, more databases are needed to increase the quality of the breeding line as well as the number of STR in order to study, with more detail, the genetic structure in the Great Dane race. 展开更多
关键词 Genetic Structure GREAT Dane VARIETIES Microsatellites POPULATION Genetics POPULATION STRATIFICATION
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Identification of Global Gene Expression Shifts Using Microarray Data from Different Biological Conditions
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作者 José Rafael Tovar Cuevas +3 位作者 Liliana Ló pez Kleine José Alejandro Ordoñ ez 《Open Journal of Statistics》 2015年第5期360-372,共13页
Gene expression data have been very useful during the past two decades for the detection of differentially expressed genes when two (or more) biological conditions are compared. Studies seeking for differentially expr... Gene expression data have been very useful during the past two decades for the detection of differentially expressed genes when two (or more) biological conditions are compared. Studies seeking for differentially expressed genes are based on testing gene by gene for a mean differential expression between two conditions. Nevertheless, the global shift in gene expression when taking into account all genes present on a microarray experiment, has not yet been investigated and could provide different information on genes that could be affected by the condition under research. Such a global approach would help identifying a gene expression threshold, characteristic of a certain condition and therefore could be used for diagnosis together with the list of differentially expressed genes detected by classical methods. Moreover, characterizing genes below or above such a threshold could give new insights into the molecular mechanisms implicated functionally in each condition. Here, we present a simple methodology, based on heuristics, gene filtering, variable transformation and descriptive statistics in order to identify such global gene expression shifts and the characteristic threshold so the same can be applied by any professional that works with expression gene data and not only by statisticians. Our procedure is illustrated on a real gene expression data set comparing pathogen inoculated tomatoes with non-inoculated tomatoes. This methodology can be used for the identification of the threshold values when we have continuous variable data sets from two populations with overlapped distributional forms (histograms) in most of their percentiles. 展开更多
关键词 Gene Expression SHIFT FILTERING Transformation THRESHOLD BIOLOGICAL CONDITIONS
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An Epidemic Model for the Propagation of Leptospirosis Outbreaks
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作者 Ariel Félix Gualtieri Juan Pedro Hecht 《Journal of Health Science》 2019年第2期135-141,共7页
Leptospirosis is a disease of worldwide distribution caused by spirochetes of the genus Leptospira.Rodents have been recognized as the most important and most widely distributed reservoirs of leptospirosis.In differen... Leptospirosis is a disease of worldwide distribution caused by spirochetes of the genus Leptospira.Rodents have been recognized as the most important and most widely distributed reservoirs of leptospirosis.In different regions of the world,there are outbreaks of leptospirosis that have a seasonal distribution and coincide with the rainy months.One way to study the spread of epidemics is through mathematical models.In the present work,the objective of the authors was to develop and explore a model of leptospirosis outbreak,combining the dynamics of propagation in human population with the dynamics of transmission from rodent reservoirs to humans.The authors designed a deterministic model based on differential equations.The dynamics of the model were explored through computational simulations.The typical evolution of prevalence observed in the model,qualitatively coincides with the dynamics of actual leptospirosis outbreaks.In the model,the peak prevalence was reduced when the transmission parameter and the number of rodents decreased,and when the lepospira decay rate increased.These results coincide with what was expected.The present development could be considered as a starting point for the generation of a more complex design. 展开更多
关键词 LEPTOSPIROSIS EPIDEMIC model SIMULATION PUBLIC HEALTH
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Projecting Health Outcomes for Portuguese Ageing Population: Challenges and Opportunities
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作者 Maria do Rosário Oliveira Martins Inês Campos Rodrigues Teresa Ferreira Rodrigues 《Health》 2014年第14期1874-1882,共9页
Objectives: To project health outcomes for the period 2011-2031, in the Portuguese population aged 65 years and over, considering the expected changes in its demographic and educational structure. Methods: Demographic... Objectives: To project health outcomes for the period 2011-2031, in the Portuguese population aged 65 years and over, considering the expected changes in its demographic and educational structure. Methods: Demographic projections were produced using the multistate cohort component method. Logistic regression models were fitted to estimate current differences in health outcomes, using data from the Portuguese Health Survey. Such differences were applied to the projection results, in order to project the prevalence of “poor” self-reported health status, functional limitations and disability. Results: Our results point to a future improvement in the considered health outcomes. The prevalence of “poor” self-reported health status, functional limitations and disability will decrease in both genders, but will continue to be higher among women than men. Discussion: Beyond age and gender, other determinants of health, like education, should be considered when studying the possible evolution of health outcomes in an ageing population. 展开更多
关键词 Projections AGING EDUCATIONAL Level SELF-REPORTED Health Status Functional LIMITATIONS and DISABILITY
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