485 research outputs found
Presence of the RHD pseudogene and the hybrid RHD-CE-Ds gene in Brazilians with the D-negative phenotype
The molecular basis for RHD pseudogene or RHDpsi is a 37-bp insertion in exon 4 of RHD. This insertion, found in two-thirds of D-negative Africans, appears to introduce a stop codon at position 210. The hybrid RHD-CE-Ds, where the 3' end of exon 3 and exons 4 to 8 are derived from RHCE, is associated with the VS+V- phenotype, and leads to a D-negative phenotype in people of African origin. We determined whether Brazilian blood donors of heterogeneous ethnic origin had RHDpsi and RHD-CE-Ds. DNA from 206 blood donors were tested for RHDpsi by a multiplex PCR that detects RHD, RHDpsi and the C and c alleles of RHCE. The RHD genotype was determined by comparison of size of amplified products associated with the RHD gene in both intron 4 and exon 10/3'-UTR. VS was determined by amplification of exon 5 of RHCE, and sequencing of PCR products was used to analyze C733G (Leu245Val). Twenty-two (11%) of the 206 D-negative Brazilians studied had the RHDpsi, 5 (2%) had the RHD-CE-Ds hybrid gene associated with the VS+V- phenotype, and 179 (87%) entirely lacked RHD. As expected, RHD was deleted in all the 50 individuals of Caucasian descent. Among the 156 individuals of African descent, 22 (14%) had inactive RHD and 3% had the RHD-CE-Ds hybrid gene. These data confirm that the inclusion of two different multiplex PCR for RHD is essential to test the D-negative Brazilian population in order to avoid false-positive typing of polytransfused patients and fetuses.76777
Efeitos da atividade física sobre densidade mineral óssea de mulheres saudáveis na pré-menopausa
Study Design: Sistematic review of literature.Aims: Physical activity is an important stimulus to increase bone mineral density (BMD). Whereby the resistance of the bone is associated with BMD, microstructure and material properties, improvements in bone mass are important to prevent osteoporosis in old ages. Despite many studies on the subject, there is no consensus on what is the best type of exercise, intensity and frequency for improvements in osteogenesis and promotion of BMD gain. This study aimed to investigate the types of physical activities that results in better osteogenic effects on increasing BMD in healthy premenopausal women.Methodology: We searched scientific articles in Pubmed and Science Direct databases published in the last ten years. We selected controlled studies which used high-impact activities or resistance training. We used systematic analysis of the selected articles.Results: Fifteen articles were included in this review, which were separated into two groups according to the type of exercise. We performed a comparative analysis of the methods used and the results achieved. There were more efficient protocols using high impact exercise even if it was a short-term program resulting in increased BMD in the proximal femur (femoral neck and intertrochanteric region).Conclusion: There were fewer studies observing increases in BMD at the lumbar spine when resistance exercise with load or high impact loads were used. Most experimental protocols performed in relatively short-term programs (6 months) demonstrated that exercise programs that were simple, easy to perform, and not using special devices are sufficient to promote bone remodeling at specific sites resulting in increased BMD.in increased BMD.Modelo de estudo: Revisão sistemática da literatura.Objetivo: A atividade física representa um importante estímulo ao aumento da densidade mineral óssea (DMO). Como a resistência dos ossos está associada tanto a DMO, quanto a microestrutura e propriedades do material, melhorias na massa óssea são importantes na prevenção de osteoporose na idade mais avançada. Apesar de muitos estudos sobre o tema, não existe consenso sobre qual seria o melhor tipo de atividade física, intensidade e frequência para melhorias na osteogênese e promoção do ganho de DMO. O objetivo deste estudo foi investigar os tipos de atividades físicas com melhor efeito osteogênico de aumento da DMO em mulheres saudáveis na pré-menopausa.Metodologia: Realizou-se levantamento bibliográfico de artigos científicos nas bases de dados Pubmed e Direct Science publicados nos últimos dez anos. Foram selecionados estudos controlados com exercícios de alto impacto e resistido. Utilizou-se análise sistematizada dos artigos selecionados.Resultados: Foram incluídos 15 artigos nesta revisão, os quais foram separados em dois grupos, conforme o tipo de exercício. Foi realizada análise comparativa de metodologias utilizadas e resultados alcançados. Constatou-se maior eficiência do protocolo de exercício de alto impacto, mesmo em curtoperíodo de execução para aumento da DMO do fêmur proximal (colo femoral e região intertrocantérica). Em menor frequência, foi observado aumento da DMO na coluna lombar quando exercícios resistidos ou de impactos maiores foram usados.Conclusões: A maioria dos artigos executou protocolo experimental em período relativamente curto (6 meses), demonstrando que programas de exercícios simples, de fácil execução, curto período de aplicação e sem uso de aparelhos específicos são suficientes para promover remodelação óssea emsítios específicos com aumento da DMO
Parental Expectations and Prosocial Behavior of Adolescents From Low-Income Backgrounds: A Cross-Cultural Comparison Between Three Countries¿Argentina, Colombia, and Spain
Parental expectations are influenced by cultural models, which in turn are subject to a great influence from historically fluctuating features of the socioeconomic background. Parental expectations seem to be linked to children¿s social and emotional development in terms of empathy and prosocial behavior. The current study aims to (a) compare low-income adolescents¿ perceptions of parental expectations of prosocial and antisocial behavior across three Latin countries (Argentina, Colombia, and Spain), (b) compare the empathy and prosocial behavior between the three countries, (c) compare the prosocial behavior between the three countries, and (d) study the effect of perceived parental expectations and empathy on the prosocial behavior of adolescents in all three of the countries studied in this research. The sample was made up of 446 Argentinean adolescents, 474 Colombian adolescents, and 632 Spanish adolescents. The Expected Parental Reactions Scale, Interpersonal Reactivity Index, and Prosocial Behavior Questionnaire were used to measure the variables included in this study. Results reveal considerable differences between children¿s perceptions of parental expectations in different countries. Results also show the existence of significant differences between male and female adolescents. In all three countries, girls score more highly than boys in prosocial behavior and empathy. Furthermore, we find that low-income Argentinean adolescents score more highly than Spanish and Colombian adolescents in prosocial behavior measures. Finally, expected parental reactions toward prosocial behavior and empathy seem to have an influence on the adolescents¿ development of prosocial behavior in all three countries
Study of the production of and hadrons in collisions and first measurement of the branching fraction
The product of the () differential production
cross-section and the branching fraction of the decay () is
measured as a function of the beauty hadron transverse momentum, ,
and rapidity, . The kinematic region of the measurements is and . The measurements use a data sample
corresponding to an integrated luminosity of collected by the
LHCb detector in collisions at centre-of-mass energies in 2011 and in 2012. Based on previous LHCb
results of the fragmentation fraction ratio, , the
branching fraction of the decay is
measured to be \begin{equation*} \mathcal{B}(\Lambda_b^0\rightarrow J/\psi
pK^-)= (3.17\pm0.04\pm0.07\pm0.34^{+0.45}_{-0.28})\times10^{-4},
\end{equation*} where the first uncertainty is statistical, the second is
systematic, the third is due to the uncertainty on the branching fraction of
the decay , and the
fourth is due to the knowledge of . The sum of the
asymmetries in the production and decay between and
is also measured as a function of and .
The previously published branching fraction of , relative to that of , is updated.
The branching fractions of are determined.Comment: 29 pages, 19figures. All figures and tables, along with any
supplementary material and additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-032.htm
Evidence for the strangeness-changing weak decay
Using a collision data sample corresponding to an integrated luminosity
of 3.0~fb, collected by the LHCb detector, we present the first search
for the strangeness-changing weak decay . No
hadron decay of this type has been seen before. A signal for this decay,
corresponding to a significance of 3.2 standard deviations, is reported. The
relative rate is measured to be
, where and
are the and fragmentation
fractions, and is the branching
fraction. Assuming is bounded between 0.1 and
0.3, the branching fraction would lie
in the range from to .Comment: 7 pages, 2 figures, All figures and tables, along with any
supplementary material and additional information, are available at
https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-047.htm
flavour tagging using charm decays at the LHCb experiment
An algorithm is described for tagging the flavour content at production of
neutral mesons in the LHCb experiment. The algorithm exploits the
correlation of the flavour of a meson with the charge of a reconstructed
secondary charm hadron from the decay of the other hadron produced in the
proton-proton collision. Charm hadron candidates are identified in a number of
fully or partially reconstructed Cabibbo-favoured decay modes. The algorithm is
calibrated on the self-tagged decay modes and using of data collected by the LHCb
experiment at centre-of-mass energies of and
. Its tagging power on these samples of
decays is .Comment: All figures and tables, along with any supplementary material and
additional information, are available at
http://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-027.htm
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