A model for the Delta(1600) resonance and gamma N -> Delta(1600) transition

A covariant spectator constituent quark model is applied to study the gamma N -> Delta(1600) transition. Two processes are important in the transition: a photon couples to the individual quarks of the Delta(1600) core (quark core), and a photon couples to the intermediate pion-baryon states (pion cloud). While the quark core contributions are estimated assuming Delta(1600) as the first radial excitation of Delta(1232), the pion cloud contributions are estimated based on an analogy with the gamma N -> Delta(1232) transition. To estimate the pion cloud contributions in the gamma N -> Delta(1600) transition, we include the relevant intermediate states, pi-N, pi-Delta, pi-N(1440) and pi-Delta(1600). Dependence on the four-momentum transfer squared, Q2, is predicted for the magnetic dipole transition form factor, GM*(Q2), as well as the helicity amplitudes, A_1/2(Q2) and A_3/2(Q2). The results at Q2=0 are compared with the existing data.Comment: To appear in Phys. Rev. D. Version with small modifications. 14 pages, 6 figures and 3 table

Energy metabolism in human pluripotent stem cells and their differentiated counterparts

Background: Human pluripotent stem cells have the ability to generate all cell types present in the adult organism, therefore harboring great potential for the in vitro study of differentiation and for the development of cell-based therapies. Nonetheless their use may prove challenging as incomplete differentiation of these cells might lead to tumoregenicity. Interestingly, many cancer types have been reported to display metabolic modifications with features that might be similar to stem cells. Understanding the metabolic properties of human pluripotent stem cells when compared to their differentiated counterparts can thus be of crucial importance. Furthermore recent data has stressed distinct features of different human pluripotent cells lines, namely when comparing embryo-derived human embryonic stem cells (hESCs) and induced pluripotent stem cells (IPSCs) reprogrammed from somatic cells. Methodology/Principal Findings: We compared the energy metabolism of hESCs, IPSCs, and their somatic counterparts. Focusing on mitochondria, we tracked organelle localization and morphology. Furthermore we performed gene expression analysis of several pathways related to the glucose metabolism, including glycolysis, the pentose phosphate pathway and the tricarboxylic acid (TCA) cycle. In addition we determined oxygen consumption rates (OCR) using a metabolic extracellular flux analyzer, as well as total intracellular ATP levels by high performance liquid chromatography (HPLC). Finally we explored the expression of key proteins involved in the regulation of glucose metabolism. Conclusions/Findings: Our results demonstrate that, although the metabolic signature of IPSCs is not identical to that of hESCs, nonetheless they cluster with hESCs rather than with their somatic counterparts. ATP levels, lactate production and OCR revealed that human pluripotent cells rely mostly on glycolysis to meet their energy demands. Furthermore, our work points to some of the strategies which human pluripotent stem cells may use to maintain high glycolytic rates, such as high levels of hexokinase II and inactive pyruvate dehydrogenase (PDH). © 2011 Varum et al

Phenotypic recurrent selection in the common bean ( Phaseolus vulgaris L) with carioca-type grains for resistance to the fungi Phaeoisariopsis griseola.

The efficiency of recurrent selection was assessed in obtaining common bean (Phaseolus vulgaris L) plant lines resistant to the phytopathogenic fungi Phaeoisariopsis griseola. The base bean population was obtained from the partial diallel between seven lines with carioca-type grains and 10 sources of resistance to P. griseola. The plants most resistant to the pathogen were selected in the F2 (S0) generation of the populations (C-0). The best S0:1 plants that presented carioca-type grains were intercrossed to obtain cycle I (C-I). The same procedure was adopted to obtain cycles C-II to C-V. In each recurrent selection cycle, S0:1 progenies selected were also assessed in experiments carried out in Lavras, Brazil, always using as check the Carioca MG (susceptible to P. griseola) and Pérola (tolerant) cultivars. The response to selection for resistance to the pathogen was estimated from the general mean of the S0:1 progenies from each selective cycle compared to the susceptible check Carioca MG. The estimated gain was 6.4% per cycle and the indirect response in grain yield by selection for resistance to the pathogen was 8.9% per cycle. The variability detected among the progenies in the last selective cycles enabled the prediction of additional responses to recurrent selection

Avaliação de progênies de um programa de seleção recorrente para feijoeiro de porte ereto.

O objetivo desse trabalho foi verificar se a seleção recorrente fenotípica foi eficiente para melhorar o porte e produtividade de grãos do feijoeiro

Implicações da severidade de mancha angular em experimentos de avaliação de linhagens elite de feijoeiro.

Para verificar se a avaliação por meio de uma escala de notas de severidade da mancha angular (Pseudocercospora griseola) contribui para explicar a variação entre linhagens de feijão com relação à produtividade de grãos, foi realizado o presente trabalho

Seleção de progênies de feijoeiro com plantas eretas e grãos tipo carioca.

Para confirmar se a população oriunda do cruzamento CVIII-8511 x BRS-Supremo, identificada em um cruzamento dialélico anteriormente realizado é realmente promissora para a seleção de plantas eretas e com boa produtividade de grãos foi realizado o presente trabalho

Controle genético do escurecimento do grão de feijão tipo carioca.

O presente trabalho teve como objetivo conhecer o controle genético do caráter da cor do fundo do grão, o que certamente auxiliará na escolha da melhor estratégia de melhoramento