Ion backflow studies with a triple-GEM stack with increasing hole pitch

Gas Electron Multipliers have undergone a very consistent development since their invention in 1997. Their production procedures have been tuned in such a way that nowadays it is possible to produce foils with areas of the order of the square meter that can operate at a reasonable gain, uniform over large areas and with a good stability in what concerns electrical discharges. For the third run of LHC, they will be included in the CMS and ALICE experiments after significant upgrades of the detectors, confirming that these structures are suitable for very large experiments. In the special case of Time Projection Chambers, the ion backflow and the energy resolution are sensitive issues that must be addressed and the GEM has shown to be able to deal with both of them. In this work, a stack of three GEMs with different pitches has been studied as a possible future approach for ion-backflow suppression to be used in TPCs and other detection concepts. With this approach, an ion backflow of 1 % with an energy resolution of 12 % at 5.9 keV has been achieved with the detector operating in an Ar/CO2 (90/10) mixture at a gain of ~ 2000.Comment: 15 pages, 11 figure

Evidence for inter- and intra-species biofilm formation variability among a small group of coagulase-negative staphylococci

Coagulase-negative staphylococci (CoNS) are common bacterial colonisers of the human skin. They are often involved in nosocomial infections due to biofilm formation in indwelling medical devices. While biofilm formation has been extensively studied in Staphylococcus epidermidis, little is known regarding other CoNS species. Here, biofilms from six different CoNS species were characterised in terms of biofilm composition and architecture. Interestingly, the ability to form a thick biofilm was not associated with any particular species, and high variability on biofilm accumulation was found within the same species. Cell viability assays also revealed different proportions of live and dead cells within biofilms formed by different species, although this parameter was particularly similar at the intra-species level. On the other hand, biofilm disruption assays demonstrated important inter- and intra-species differences regarding extracellular matrix composition. Lastly, confocal laser scanning microscopy (CLSM) experiments confirmed this variability, highlighting important differences and common features of CoNS biofilms. We hypothesised that the biofilm formation heterogeneity observed was rather associated with biofilm matrix composition than with cells themselves. Additionally, our results indicate that polysaccharides, DNA and proteins are fundamental pieces in the process of CoNS biofilm formation.This work was co-funded by FCT Strategic Project PEst-OE/EQB/LA0023/2013, FCT project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and by QREN, FEDER, ON2 project NORTE-07-0124-FEDER-000027. NC is an Investigador FCT

Emergence of classicality in small number entangled systems

We show the transition from a fully quantized interaction to a semiclassical one in entangled small number quantum systems using the quantum trajectories approach. In particular, we simulate the microwave Ramsey zones used in Rydberg atom interferometry, filling in the gap between the strongly entangling Jaynes Cummings evolution and the semiclassical rotation of the atomic internal states. We also correlate the information flowing with leaking photons to the entanglement generation between cavity field and flying atom and detail the roles played by the strong dissipation and the external driving force in preserving atomic coherence through the interaction.Comment: 4 pages, 6 figure

Indicadores de viabilidade financeira e econômica do sistema de produção familiar de leite de cabra no Rio Grande do Norte.

Resumo - O trabalho objetivou identificar um modelo e exploração de leite de cabra por agricultores familiares, por meio de indicadores de viabilidade da exploração no Rio Grande Norte, para subsidiar os produtores em suas decisões de gerenciar e/ou investir na atividade. A seleÁ?o do Estado foi feita por ser o maior produtor nordestino de leite de cabra. O modelo adotado de estrutura de custos e receitas e medidas de resultados foi o do Instituto de Economia Agrícola de São Paulo. Utilizaram-se, também, metodologias de análise econômico-financeira para se conhecer a taxa interna de retorno (TIR), o valor presente lÌquido (VPL) e a relação Benefício/Custo sob as óticas financeira e econômica. Os resultados do modelo construído para gerar de três a quatro salários mínimos mensais foram: área de 100 ha, investimentos totais de R$55 mil, 50 matrizes em lactação, 50 litros de leite/dia, custo de produção de um litro de leite: R$ 0,76 e de venda: R$1,03, lucratividade de 24$ 1.276,00, TIR financeira 77% e econômica de 179%. O VPL econômico foi 16% superior ao financeiro e a relação Benefício/Custo foi de 1,57, sob a ótica financeira, e 1,79 na econômica. Os indicadores mostram a viabilidade do negócio, com destaque para a viabilidade econômica, que se traduz na contribução dos caprinocultores para com a sociedade, uma vez que geram um VPL de R$95,4 mil e apropriam-se de apenas R$ 82,3 mil. Abstract - This paper analyses through viability indicator a production of goat milk model used by familiar farmers in Rio Grande do Norte and can be used to subsidize the decision making about management and/or investment on activity. The used model of costs, revenues and results measure was the methodology utilized by Instituto de Economia AgrÌcola of S?o Paulo. Also, were utilized methodologies of analyses economic and financial to know the net present value, internal tax of return and the benefit/cost relation. The model was constructed to generate an average income of three to four minimum wages by month and the results were: area of 100 hectares, total investment of R$55,000.00, fifty does in lactation, fifty liters of milk by day, production cost of R$ 0.76 by liter of milk, selling price of R$1.03, profitability of 24$ 1,276.00, financial internal tax of return of 77% and economic internal tax of return of 179%. The economic net present value was 16% higher than the financial and the benefit/cost relation was 1.57 under the financial vision and 1.79 under the economic vision. The indicators show a viability of the business, emphasizing the economic viability where the producers of goat milk contribute to the society since that they produce a net present value of R$95,400.00 and only take possession of R$ 82,300.00

Avaliação in vitro de óleos essenciais e extrato de cravo da índia no crescimento micelial de Fusarium oxysporum.

Resumos

Produtividade de Laranjeira Pêra sob porta-enxertos híbridos de Trifoliata.

No Brasil, o principal porta-enxerto utilizado para laranjeira Pera [Citrus sinensis (L.) Osbeck] é o limoeiro Cravo (C. limonia Osbeck). Todavia, este apresenta suscetibilidade ao declínio e à morte súbita dos citros (MSC), além de conferir aos frutos qualidade inferior à relacionada a outros porta-enxertos, como a tangerineira Sunki [C. sunki (Hayata) hort. ex Tanaka]

Produtividade de 13 variedades de Laranjeira Doce no Litoral Norte da Bahia..

O Brasil é o maior produtor mundial de laranja doce [Citrus sinensis (L.) Osbeck], respondendo por metade do suco de laranja produzido globalmente. Objetivou-se com esse estudo avaliar a produtividade de 13 variedades de laranjeira doce no Litoral Norte da Bahia