Systematics of soft final state interactions in BB decay

By using very general and well established features of soft strong interactions we show, contrary to conventional expectations, that (i) soft final state interactions (FSI) do not disappear for large $m_B$, (ii) inelastic rescattering is expected to be the main source of soft FSI phases, and (iii) flavor off-diagonal FSI are suppressed by a power of $m_B$, but are quite likely to be significant at $m_B\simeq 5$~GeV. We briefly discuss the influence of these interactions on tests of CP-violation and on theoretical calculations of weak decays.Comment: 11 pages, REVTeX, no figure

Modulation of siderophore production by Pseudomonas fluorescens through the manipulation of the culture medium composition

Pseudomonas fluorescens has the ability to produce the siderophore pyoverdine, a biotechnologically significant iron chelator, which has a wide range of potential applications, such as in agriculture (iron fertilizers) and medicine (development of antibiotics). The present work aimed to evaluate the influence of culture medium composition on the production of siderophores by P. fluorescens DSM 50090, an industrial relevant strain. It was found that the bacterium grown in minimal medium succinate (MMS) had a higher siderophore production than in King B medium. The replacement of succinate by glycerol or dextrose, in minimal medium, originated lower siderophore production. The increase of succinate concentration, the addition of amino acids or the reduction of phosphate in the culture medium did not improve siderophore production by P. fluorescens. The results obtained strongly suggest that (i) MMS is more appropriate than King B for large-scale production of siderophores; (ii) the modification of the culture medium composition, particularly the type of carbon source, influences the level of siderophore secreted; (iii) the production of siderophore by P. fluorescens seems to be a tightly regulated process; once a maximum siderophore concentration has been reached in the culture medium, the bacterium seems to be unable to produce more compound.João M. Vindeirinho received the grant from the project PTDC-AGR-TEC/0458/2014—POCI-01-0145-FEDER-016681. This work is financed by the FEDER funds through the Operational Competitiveness Factors Program—COMPETE and by national funds through FCT—Foundation for Science and Technology within the scope of the project PTDC-AGR-TEC/0458/2014—POCI-01-0145-FEDER-016681.info:eu-repo/semantics/publishedVersio

Cronologia absoluta para o campaniforme da Estremadura e do sudoeste de Portugal

Separata de "O Arqueólogo Português"Mais de vinte datas de radiocarbono são actualmente conhecidas para contextos campaniformes na Estemadura e no Sul de Portugal. Por outro lado, escavações recentes isolaram contextos campaniformes bem definidos, que foram datados. Estes dados permitem novas interpretações para o fenómeno campaniforme, bem como o estabelecimento de uma cronologia mais precisa para o mesmo.At present twenty radiocarbon dates are knoun for bell beakers in Estremadura and the soutb of Portugal. 0n the other hand, recent archaeological digging allowed to isolate well defined bell beaker contexts, wbich were radiocarbono dated these new data allow new interpretations for the bell beaker phenomenon, as a more precise chronology for the different pottery styles

Combining exclusive semi-leptonic and hadronic B decays to measure |V_ub|

The Cabibbo-Kobayashi-Maskawa matrix element |V_ub| can be extracted from the rate for the semi-leptonic decay B -> pi + l + antineutrino_l, with little theoretical uncertainty, provided the hadronic form factor for the B -> pi transition can be measured from some other B decay. In here, we suggest using the decay B -> pi J\psi. This is a color suppressed decay, and it cannot be properly described within the usual factorization approximation; we use instead a simple and very general phenomenological model for the b d J\psi vertex. In order to relate the hadronic form factors in the B -> pi J\psi and B -> pi + l + antineutrino_l decays, we use form factor relations that hold for heavy-to-light transitions at large recoil.Comment: Latex, 7 pages, no figure

A duna consolidada de Oitavos, a Oeste de Cascais, região de Lisboa : a sua datação pelo método do radiocarbono

A duna consolidada de Oitavos, atribuída ao Quaternário, situa-se junto ao litoral, a oeste de Cascais. Apresenta-se o programa de datações pelo radiocarbono que permitiu a datação dessa duna e discute-se a fiabilidade das datas obtidas. Processaram-se amostras de Helix provenientes não só da duna de Oitavos, mas também da duna consolidada de Magoito, localizada cerca de 16 km para norte e já devidamente datada por aquele método de datação absoluta, e ainda amostras de um contexto arqueológico da Encosta de Sant'Ana (Baixa da cidade de Lisboa), com o objectivo de aferir a validade das datações de Oitavos sobre Helix. Também o paleossolo existente na base da duna de Oitavos foi objecto de datação. Determinou-se assim uma data de elevada fiabilidade para a geração da duna de Oitavos, indicando que esta se terá formado no intervalo 33-30 ka BP, provavelmente durante o interestadial que precede a fase final do OIS 3

Structural characterization of the Aspergillus niger citrate transporter CexA uncovers the role of key residues S75, R192 and Q196

Supplementary data associated with this article can be found in the online version at doi:10.1016/j.csbj.2023.04.025.The Aspergillus niger CexA transporter belongs to the DHA1 (Drug-H+ antiporter) family. CexA homologs are exclusively found in eukaryotic genomes, and CexA is the sole citrate exporter to have been functionally characterized in this family so far. In the present work, we expressed CexA in Saccharomyces cerevisiae, demonstrating its ability to bind isocitric acid, and import citrate at pH 5.5 with low affinity. Citrate uptake was independent of the proton motive force and compatible with a facilitated diffusion mechanism. To unravel the structural features of this transporter, we then targeted 21 CexA residues for site-directed mutagenesis. Residues were identified by a combination of amino acid residue conservation among the DHA1 family, 3D structure prediction, and substrate molecular docking analysis. S. cerevisiae cells expressing this library of CexA mutant alleles were evaluated for their capacity to grow on carboxylic acid-containing media and transport of radiolabeled citrate. We also determined protein subcellular localization by GFP tagging, with seven amino acid substitutions affecting CexA protein expression at the plasma membrane. The substitutions P200A, Y307A, S315A, and R461A displayed loss-of-function phenotypes. The majority of the substitutions affected citrate binding and translocation. The S75 residue had no impact on citrate export but affected its import, as the substitution for alanine increased the affinity of the transporter for citrate. Conversely, expression of CexA mutant alleles in the Yarrowia lipolytica cex1Δ strain revealed the involvement of R192 and Q196 residues in citrate export. Globally, we uncovered a set of relevant amino acid residues involved in CexA expression, export capacity and import affinity.This work was supported by the Strategic Programme UID/BIA/04050/2020 and the project LA/P/0069/2020 granted to the Associate Laboratory ARNET, both funded by Portuguese funds through the FCT-IP. J.A. acknowledges the FCT and the Doctoral Program in Applied and Environmental Microbiology for the PD/BD/150584/2020 PhD grant and a COST Action CA18113 Short-Term Scientific Mission grant (EuroMicropH). M.S.S. acknowledges the Norte2020 for the UMINHO/BD/25/2016 PhD grant with the re ference NORTE-08-5369-FSE-000060. I.S-S. was supported by the program contract FCTUMINHO/Norma transitória from the Legal Regime of Scientific Employment (RJEC)

Integração de métodos de modelação geométrica, elementos finitos e programação matemática no projecto estructural

A optimizacáo de forma de componentes estruturais, sujeitos a esforcos de membrana, é obtida recorrendo a um modelo numérico que integra modelacáo geométrica, análise por elementos finitos e programacáo matemática. Curvas paramétricas SEO utilizadas para definir a fronteira do domínio, sendo a posicáo dos seus nós assumida como variáveis de projecto. Para cada configuraciio, um gerador de malhaelíptico permite obter automáticamente a discretizacáo elíptico necessári a A solucáo por elementos finitos. As sensibilidades sáo calculadas pela técnica semi-analítica e pelo método directo, podendo ser visualizadas gráficamente.. O método da programacáo sequencial convexa é utilizado na fase de optimizacao. A implementacao é feita com enfase na utilizacáo de gráficos interactivos e em linguagens de programacáo normalizadas, de forma a permitir a portabilidade do sistema desenvolvido.Shape optimization of two dimensional elasticity problems is obtained with a numerical model which integrates geometric modelling, finite elements analysis and mathematical programming. Parametric curves are used to define the boundary of the domain, the position of their nodes is taken as design variables. For each configuration, an elliptic mesh generator obtains automatically the finite element discretization necessary to get the solution. Sensibilities are calculated by the semi-analiticat technique and by the direct method, and can be visualized graphicaly. The method of sequencial con'vex programming is used at the optimization phase. Implementation is made with emphasys on interactive graphics and in standard computer languages, allowing portability of the developed system.Peer Reviewe

Investment optimization in distribution network based on fuzzy outage parameters

This paper presents a methodology that aims to increase the probability of delivering power to any load point of the electrical distribution system by identifying new investments in distribution components. The methodology is based on statistical failure and repair data of the distribution power system components and it uses fuzzy-probabilistic modelling for system component outage parameters. Fuzzy membership functions of system component outage parameters are obtained by statistical records. A mixed integer non-linear optimization technique is developed to identify adequate investments in distribution networks components that allow increasing the availability level for any customer in the distribution system at minimum cost for the system operator. To illustrate the application of the proposed methodology, the paper includes a case study that considers a real distribution network

Integração de métodos de modelação geométrica, elementos finitos e programação matemática no projecto estructural

A optimizacáo de forma de componentes estruturais, sujeitos a esforcos de membrana, é obtida recorrendo a um modelo numérico que integra modelacáo geométrica, análise por elementos finitos e programacáo matemática. Curvas paramétricas SEO utilizadas para definir a fronteira do domínio, sendo a posicáo dos seus nós assumida como variáveis de projecto. Para cada configuraciio, um gerador de malhaelíptico permite obter automáticamente a discretizacáo elíptico necessári a A solucáo por elementos finitos. As sensibilidades sáo calculadas pela técnica semi-analítica e pelo método directo, podendo ser visualizadas gráficamente.. O método da programacáo sequencial convexa é utilizado na fase de optimizacao. A implementacao é feita com enfase na utilizacáo de gráficos interactivos e em linguagens de programacáo normalizadas, de forma a permitir a portabilidade do sistema desenvolvido.Shape optimization of two dimensional elasticity problems is obtained with a numerical model which integrates geometric modelling, finite elements analysis and mathematical programming. Parametric curves are used to define the boundary of the domain, the position of their nodes is taken as design variables. For each configuration, an elliptic mesh generator obtains automatically the finite element discretization necessary to get the solution. Sensibilities are calculated by the semi-analiticat technique and by the direct method, and can be visualized graphicaly. The method of sequencial con'vex programming is used at the optimization phase. Implementation is made with emphasys on interactive graphics and in standard computer languages, allowing portability of the developed system.Peer Reviewe