1,709 research outputs found
Spherical Collapse and the Halo Model in Braneworld Gravity
We present a detailed study of the collapse of a spherical perturbation in
DGP braneworld gravity for the purpose of modeling simulation results for the
halo mass function, bias and matter power spectrum. The presence of evolving
modifications to the gravitational force in form of the scalar brane-bending
mode lead to qualitative differences to the collapse in ordinary gravity. In
particular, differences in the energetics of the collapse necessitate a new,
generalized method for defining the virial radius which does not rely on strict
energy conservation. These differences and techniques apply to smooth dark
energy models with w unequal -1 as well. We also discuss the impact of the
exterior of the perturbation on collapse quantities due to the lack of a
Birkhoff theorem in DGP. The resulting predictions for the mass function, halo
bias and power spectrum are in good overall agreement with DGP N-body
simulations on both the self-accelerating and normal branch. In particular, the
impact of the Vainshtein mechanism as measured in the full simulations is
matched well. The model and techniques introduced here can serve as practical
tools for placing consistent constraints on braneworld models using
observations of large scale structure.Comment: 20 pages, 16 figures; v2: minor addition to appendix; matches
published version; v3: typos in Eqs. (20), (23) correcte
Testes de racionalidade para loterias no Brasil
The paper investigates the prevalence of rational expectations in the case of two Brazilian lotteries (Quina and Mega-Sena). The testing strategy relates to an orthogonality condition between the conditional forecast error and the information set. Specifically, the residual of a equation for net price of a lottery ticket should be uncorrelated with sales The results favoured the rational expectations hypothesis only in the case of the Mega-Sena that is subject to broad media coverage. Clearly the Quina lottery is associated with a diferent profile of betters.O artigo investiga a prevalência de expectativas racionais no caso de duas loterias brasileiras (Quina e Mega-Sena). A estratégia de teste se relaciona com uma condição de ortogonalidade entre o erro condicional de previsão e o conjunto de informação. Especificamente, o resíduo de uma equação para o preço líquido de um bilhete de loteria deveria ser não correlacionado com as vendas. Os resultados favoreceram a hipótese de expectativas racionais somente no caso da Mega-Sena que é sujeita a ampla cobertura da mídia. Claramente a Quina está associada a um perfil distinto de apostadores
Temporal and spatial trends of adult mortality in small areas of Brazil, 1980–2010
To determine the variations and spatial patterns of adult mortality across regions, over time, and by sex for 137 small areas in Brazil, we first apply TOPALS to estimate and smooth mortality rates and then use death distribution methods to evaluate the quality of the mortality data. Lastly, we employ spatial autocorrelation statistics and cluster analysis to identify the adult mortality trends and variations in these areas between 1980 and 2010. We find not only that regions in Brazil’s South and Southeast already had complete death registration systems prior to the study period, but that the completeness of death count coverage improved over time across the entire nation—most especially in lesser developed regions—probably because of public investment in health data collection. By also comparing adult mortality by sex and by region, we document a mortality sex differential in favor of women that remains high over the entire study period, most probably as a result of increased morbidity from external causes, especially among males. This increase also explains the concentration of high male mortality levels in some areas76CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES470866/2014-4; 454223/2014-5não te
Methods for evaluation of the antimicrobial activity and determination of Minimum Inhibitory Concentration (MIC) of plant extracts
Várias pesquisas vêm sendo desenvolvidas e direcionadas no descobrimento de novos agentes antimicrobianos provenientes de extratos de plantas e outros produtos naturais, para serem aplicados em produtos farmacêuticos e cosméticos. Atualmente, existem vários métodos para avaliar a atividade antibacteriana e antifúngica dos extratos vegetais. Os mais conhecidos incluem método de difusão em ágar, método de macrodiluição e microdiluição. A proposta dessa revisão é apresentar diferentes métodos comumente utilizados na pesquisa de novos agentes antimicrobianos, provenientes de extratos vegetais, e elucidar os principais fatores interferentes. Dessa maneira, contribuir como fonte de pesquisa para o desenvolvimento de futuros trabalhos relacionado ao estudo de atividade antimicrobiana de produtos naturais.Several researches have been developed to search for new antimicrobial agents from extracts of plants and other natural products to be used in pharmaceutical and cosmetic products. Nowadays there are many methods to evaluate the antibacterial and antifungal activity of the plant extracts. The most known assays have been based on diffusion in agar; and micro and macrodilution methods. The purpose of this review is to describe the different methods commonly used for the determination of new antimicrobial agents from the plants extracts and elucidate the main interference factors. Moreover, this contributes as research source for future development of investigations related to the study of antimicrobial activity from natural products.Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)CNP
Characterization of Fuji Apples from Different Harvest Dates and Storage Conditions from Measurements of Volatiles by Gas Chromatography and Electronic Nose
Volatile compounds in Fuji apples harvested at two different maturities were measured at harvest
and after 5 and 7 months of cold storage (1 °C) in four different atmospheres. When the samples
were characterized by both chromatographic measurements of volatiles and responses of an electronic
nose, the analyses showed a clear separation between fruits from different storage conditions (a
normal cold atmosphere and three controlled atmospheres). During poststorage, the apples were
left to ripen for 1, 5, and 10 days at 20 °C before analytical measurements were done involving
headspace-gas chromatography methods and electronic nose type quartz crystal microbalances.
Electronic nose responses registered by seven different sensors were used to classify the apples
using principal component analysis. It was possible to identify the samples from different storage
periods, days of shelf life, and harvest dates, but it was not possible to differentiate the fruits
corresponding to different cold storage atmospheres
Dengue Infection Increases the Locomotor Activity of Aedes aegypti Females
BACKGROUND: Aedes aegypti is the main vector of the virus causing Dengue fever, a disease that has increased dramatically in importance in recent decades, affecting many tropical and sub-tropical areas of the globe. It is known that viruses and other parasites can potentially alter vector behavior. We investigated whether infection with Dengue virus modifies the behavior of Aedes aegypti females with respect to their activity level. METHODS/PRINCIPAL FINDINGS: We carried out intrathoracic Dengue 2 virus (DENV-2) infections in Aedes aegypti females and recorded their locomotor activity behavior. We observed an increase of up to ∼50% in the activity of infected mosquitoes compared to the uninfected controls. CONCLUSIONS: Dengue infection alters mosquito locomotor activity behavior. We speculate that the higher levels of activity observed in infected Aedes aegypti females might involve the circadian clock. Further studies are needed to assess whether this behavioral change could have implications for the dynamics of Dengue virus transmission
Proceedings from the National Cancer Institute’s Second International Workshop on the Biology, Prevention, and Treatment of Relapse after Hematopoietic Stem Cell Transplantation: Part III. Prevention and treatment of relapse after allogeneic transplantation
AbstractIn the Second Annual National Cancer Institute’s Workshop on the Biology, Prevention, and Treatment of Relapse after Hematopoietic Stem Cell Transplantation, the Scientific/Educational Session on the Prevention and Treatment of Relapse after Allogeneic Transplantation highlighted progress in developing new therapeutic approaches since the first relapse workshop. Recent insights that might provide a basis for the development of novel, practical clinical trials were emphasized, including utilization of newer agents, optimization of donor lymphocyte infusion (DLI), and investigation of novel cellular therapies. Dr. de Lima discussed pre-emptive and maintenance strategies to prevent relapse after transplantation, for example, recent promising results suggestive of enhanced graft-versus-tumor activity with hypomethylating agents. Dr. Schmid provided an overview of adjunctive strategies to improve cell therapy for relapse, including cytoreduction before DLI, combination of targeted agents with DLI, and considerations in use of second transplantations. Dr. Porter addressed strategies to enhance T cell function, including ex vivo activated T cells and T cell engineering, and immunomodulatory approaches to enhance T cell function in vivo, including exogenous cytokines and modulation of costimulatory pathways
Dysregulation of T cell receptor N-glycosylation: A molecular mechanism involved in ulcerative colitis
The incidence of inflammatory bowel disease is increasing worldwide and the underlying molecular mechanisms are far from being fully elucidated. Herein, we evaluated the role of N-glycosylation dysregulation in T cells as a key mechanism in the ulcerative colitis (UC) pathogenesis. The evaluation of the branched N-glycosylation levelsandprofile of intestinalTcell receptor (TCR)wereassessedin colonic biopsies fromUCpatientsand healthy controls. Expression alterations of the glycosyltransferase gene MGAT5 were also evaluated. We demonstrated thatUCpatients exhibit a dysregulation ofTCRbranchedN-glycosylationonlamina propriaTlymphocytes. Patients with severe UC showed the most pronounced defect on N-glycan branching in T cells. Moreover, UC patients showed a significant reduction of MGAT5 gene transcription in T lymphocytes. In this study, we disclose for the first time that a deficiency in branched N-glycosylation on TCR due to a reduced MGAT5 gene expression is a new molecular mechanism underlying UC pathogenesis, being a potential novel biomarker with promising clinical and therapeutic applications.This work was supported by grants from the Portuguese Foundation for Science and Technology (FCT), project grants (PTDC/ CVT/111358/2009; PTDC/BBB-EBI/0786/2012; EXPL/ BIM-MEC/0149/2012), ‘financiados no âmbito do Programa Operacional Temático Factores de Competitividade (COMPETE) e comparticipado pelo fundo Comunitário Europeu FEDER’, e do Quadro de Referência Estratégia Nacio-nal QREN. This work was further supported by a portuguese grant from ‘Grupo de Estudo da Doenc¸a Inflamatória Intestinal’ (GEDII). S.S.P. (SFRH/BPD/63094/2009); S.C. (SFRH/BD/ 77386/2011) also acknowledge FCT. IPATIMUP is an Associate Laboratory of the Portuguese Ministry of Science, Technology and Higher Education, and is partially supported by FCT
Applications of fractional calculus in electrical and computer engineering
Fractional Calculus (FC) goes back to the beginning of the theory of differential calculus. Nevertheless, the application of FC just emerged in the last two decades, due to the progress in the area of chaos that revealed subtle relationships with the FC concepts. In the field of dynamical systems theory some work has been carried out but the proposed models and algorithms are still in a preliminary stage of establishment. Having these ideas in mind, the paper discusses a FC perspective in the study of the dynamics and control of several systems. This article illustrates several applications of fractional calculus in science and engineering. It has been recognized the advantageous use of this mathematical tool in the modeling and control of many dynamical systems. In this perspective, this paper investigates the use of FC in the fields of controller tuning, electrical systems, digital circuit synthesis, evolutionary computing, redundant robots, legged robots, robotic manipulators, nonlinear friction and financial modeling.N/
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