1,906 research outputs found
PRODUÇÃO CIENTÍFICA BRASILEIRA EM ADMINISTRAÇÃO NA DÉCADA DE 2000
Presentation at the forum: scientific production in Business Administration in the period 2000-2010 with reflections and ideas in the area. Presentation at the forum: scientific production in Business Administration in the period 2000-2010 with reflections and ideas in the area
An Improved Description of the Dielectric Breakdown in Oxides Based on a Generalized Weibull distribution
In this work, we address modal parameter fluctuations in statistical
distributions describing charge-to-breakdown and/or
time-to-breakdown during the dielectric breakdown regime of
ultra-thin oxides, which are of high interest for the advancement of electronic
technology. We reobtain a generalized Weibull distribution (-Weibull), which
properly describes data when oxide thickness fluctuations are
present, in order to improve reliability assessment of ultra-thin oxides by
time-to-breakdown extrapolation and area scaling. The incorporation
of fluctuations allows a physical interpretation of the -Weibull
distribution in connection with the Tsallis statistics. In support to our
results, we analyze data of SiO-based MOS devices obtained
experimentally and theoretically through a percolation model, demonstrating an
advantageous description of the dielectric breakdown by the -Weibull
distribution.Comment: 5 pages, 3 figure
BioWorkbench: A High-Performance Framework for Managing and Analyzing Bioinformatics Experiments
Advances in sequencing techniques have led to exponential growth in
biological data, demanding the development of large-scale bioinformatics
experiments. Because these experiments are computation- and data-intensive,
they require high-performance computing (HPC) techniques and can benefit from
specialized technologies such as Scientific Workflow Management Systems (SWfMS)
and databases. In this work, we present BioWorkbench, a framework for managing
and analyzing bioinformatics experiments. This framework automatically collects
provenance data, including both performance data from workflow execution and
data from the scientific domain of the workflow application. Provenance data
can be analyzed through a web application that abstracts a set of queries to
the provenance database, simplifying access to provenance information. We
evaluate BioWorkbench using three case studies: SwiftPhylo, a phylogenetic tree
assembly workflow; SwiftGECKO, a comparative genomics workflow; and RASflow, a
RASopathy analysis workflow. We analyze each workflow from both computational
and scientific domain perspectives, by using queries to a provenance and
annotation database. Some of these queries are available as a pre-built feature
of the BioWorkbench web application. Through the provenance data, we show that
the framework is scalable and achieves high-performance, reducing up to 98% of
the case studies execution time. We also show how the application of machine
learning techniques can enrich the analysis process
Indications for pediatric hematopoietic stem cell transplantation: consensus presented at the First Meeting on Brazilian Hematopoietic Stem Cell Transplantation Guidelines - Brazilian Society of Bone Marrow Transplantation, Rio de Janeiro, 2009
The Brazilian Bone Marrow Transplant Society (SBTMO) held its First Meeting on Bone Marrow Transplant Guidelines in 2009. A working group of hematologists and oncologists with experience in pediatrics was formed to review evidence-based indications for pediatric transplants. Scientific publications were carefully assessed and, for each disease, the evidence for recommendation (from A to C) and the quality of the evidence (from 1 to 3) were defined. The recommendations include malignant and non-malignant hematological diseases, solid tumors, immunodeficiency, and storage diseases treated with hematopoietic stem cell transplants: either autologous or allogeneic from matched sibling donors or unrelated donors (adults or umbilical cord blood). Guidelines for reduced-intensity transplants, manipulated grafts or partially compatible donors were not included as there are no uniformly accepted recommendations. All indications are based on the best current knowledge which may change over time. Thus, this review should not be directly applied to patient care without taking into account the disease, donor and patient characteristics. Additionally, this paper should not be used as a document to limit patient access to transplant if correctly indicated. In this review we also point out differences between transplantation in adults and children and make some specific recommendations for pediatric transplants.A Sociedade Brasileira de Transplante de Medula (SBTMO) promoveu o I Encontro de Diretrizes do Transplante de Medula Óssea em 2009. Para revisão das indicações de transplante em Pediatria baseadas em evidências foi constituído grupo de trabalho com oncologistas e hematologistas com experiência em pediatria. Os artigos científicos foram cuidadosamente avaliados e, para cada doença, foram definidas as evidências para recomendação dos transplantes (de A a C) e a qualidade destas evidências (de 1 a 3). As recomendações incluem doenças hematológicas malignas e não malignas, tumores sólidos, imunodeficiências e doenças de depósito tratadas com transplantes de células-tronco hematopoéticas, quer autólogos, alogênicos de irmão HLA compatível ou não aparentados (doadores adultos ou sangue de cordão umbilical). Como não existem recomendações uniformemente aceitas em pediatria, não foram incluídas recomendações para transplantes de intensidade reduzida, com manipulação do enxerto e nem parcialmente compatíveis. É importante ressaltar que todas as indicações são baseadas no conhecimento atual e podem modificar-se com o tempo. Assim, esta revisão não deve ser utilizada para aplicação direta no cuidado do paciente sem levar em conta características da doença, do doador e fatores de risco do próprio paciente. Este trabalho não deve ainda ser utilizado como documento que limite o acesso do paciente ao transplante adequadamente indicado. Ressaltamos ainda, nesta revisão, diferenças entre transplantes em crianças e em adultos, com algumas recomendações específicas para os transplantes em pediatria.UNIFESPUniversidade Federal do ParanáUFRGSHospital Amaral CarvalhoHospital de Clínicas de Porto AlegreUNIFESPSciEL
Alternative methodology for Scott-Knott test
The test proposed by Scott Knott (1974), a procedure of means grouping, is an effective alternative to performprocedures of multiple comparisons without ambiguity. This study aimed to propose a modification related to the partitioningand means grouping in the said procedure, to obtain results without ambiguity among treatments, organized in morehomogeneous groups. In the proposed methodology, treatments that did not participate in the initial group are joined for a newanalysis, which allows for a better group distribution. In a comparative study, four experiments were simulated in a randomizedcomplete block design. The first consisted of 10 and the other 3 of 100 treatments. All experiments were performed in threereplications at a significance level of 0.05 for the means grouping test. Only in the third experiment of those of 100 treatmentsthe groups formed by Scott-Knott did not differ from the methodology proposed here. The proposed methodology is consideredeffective, aiming at the identification of elite cultivar groups for recommendation
Activation profile of pro-inflammatory cytokines in acute cardiac overload
INTRODUCTION:Pro-inflammatory cytokines have been implicated in ventricular remodeling during heart failure progression. In the present study, we investigated the effects of acute volume and RV pressure overload on biventricular hemodynamics and myocardial gene expression of IL-6 and TNF-alpha.METHODS:Male Wistar rats (n = 45) instrumented with RV and LV tip micromanometers were randomly assigned to one of three protocols: i) acute RV pressure overload (PrOv) induced by pulmonary trunk banding in order to double RV peak systolic pressure, for 120 or 360 min; ii) acute volume overload (VolOv) induced by dextran40 infusion (5 ml/h), for 120 or 360 min; iii) Sham. Free wall samples from the RV and LV were collected for mRNA quantification.RESULTS:In the RV, acute overload induced IL-6 and TNF-alpha gene expression, higher in VolOv (IL-6: + 669.7 +/- 263.4%; TNF-alpha: + 5149.9 +/- 1099.0%; 360 min) than in PrOv (IL-6: + 64.9 +/- 44.2%; TNF-alpha: + 628.1 +/- 229.3%; 360 min). In PrOv, TNF-alpha mRNA levels in the LV were increased, in the absence of ventricular overload. IL-6 and TNF-alpha mRNA levels did not correlate in the LV, while in the RV a positive correlation was found (r = 0.574; p < 0.001).CONCLUSIONS:Acute cardiac overload induces overexpression of pro-inflammatory cytokines. This gene activation is not uniform, being higher in volume overload and involving both load-dependent and load-independent mechanisms
Intraocular pressure profile during the modified diurnal tension curve using Goldman applanation tonometry and dynamic contour tonometry
The aim of this study was to compare the intraocular pressure (IOP) profile during the modified diurnal tension curve (mDTC) using Goldman applanation tonometry (GAT) and dynamic contour tonometry (DCT) in treated glaucomatous eyes. Eligible subjects were submitted to the mDTC using GAT and DCT in this sequence. IOP measurements were performed at 8 a.m., 10 a.m., 2 p.m., and 4 p.m.. Central corneal thickness was measured using ultrasound pachymetry in the morning. Statistical analysis was performed using paired Student’s t test and Bland–Altman plot. The mean difference between DCT and GAT measurements was 0.9 mmHg. The mean ± SD IOP measurements during the mDTC were 19.68 ± 4.68, 17.63 ± 4.44, 17.25 ± 5.41, and 17.32 ± 4.25 mmHg using GAT and 19.97 ± 4.75, 18.79 ± 4.61, 19.53 ± 5.30, and 19.43 ± 5.45 mmHg using DCT. IOP measurements were higher in the morning (8 a.m.) and decreased throughout the day using both tonometers. The difference between IOP measurements using GAT and DCT was smaller in the morning and increased throughout the day. The IOP variability using GAT was higher than using DCT. Corneal biomechanical properties might help explain our findings
Studies of di-jet survival and surface emission bias in Au+Au collisions via angular correlations with respect to back-to-back leading hadrons
We report first results from an analysis based on a new multi-hadron
correlation technique, exploring jet-medium interactions and di-jet surface
emission bias at RHIC. Pairs of back-to-back high transverse momentum hadrons
are used for triggers to study associated hadron distributions. In contrast
with two- and three-particle correlations with a single trigger with similar
kinematic selections, the associated hadron distribution of both trigger sides
reveals no modification in either relative pseudo-rapidity or relative
azimuthal angle from d+Au to central Au+Au collisions. We determine associated
hadron yields and spectra as well as production rates for such correlated
back-to-back triggers to gain additional insights on medium properties.Comment: By the STAR Collaboration. 6 pages, 2 figure
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