An ``Improved" Lattice Study of Semi-leptonic Decays of D-Mesons

We present results of a lattice computation of the matrix elements of the vector and axial-vector currents which are relevant for the semi-leptonic decays $D \rightarrow K$ and $D \rightarrow K^*$. The computations are performed in the quenched approximation to lattice QCD on a $24^3 \times 48$ lattice at $\beta=6.2$, using an $O(a)$-improved fermionic action. In the limit of zero lepton masses the semi-leptonic decays $D \rightarrow K$ and $D \rightarrow K^*$ are described by four form factors: $f^{+}_K,V,A_1$ and $A_2$, which are functions of $q^2$, where $q^{\mu}$ is the four-momentum transferred in the process. Our results for these form factors at $q^2=0$ are: f^+_K(0)=0.67 \er{7}{8} , V(0)=1.01 \err{30}{13} , A_1(0)=0.70 \err{7}{10} , A_2(0)=0.66 \err{10}{15} , which are consistent with the most recent experimental world average values. We have also determined the $q^2$ dependence of the form factors, which we find to be reasonably well described by a simple pole-dominance model. Results for other form factors, including those relevant to the decays \dpi and \drho, are also given.Comment: 41 pages, uuencoded compressed postscript file containing 14 figures, LaTeX, Edinburgh Preprint 94/546 and Southampton Preprint SHEP 93/94-3

Colloid-stabilized emulsions: behaviour as the interfacial tension is reduced

We present confocal microscopy studies of novel particle-stabilized emulsions. The novelty arises because the immiscible fluids have an accessible upper critical solution temperature. The emulsions have been created by beginning with particles dispersed in the single-fluid phase. On cooling, regions of the minority phase nucleate. While coarsening these nuclei become coated with particles due to the associated reduction in interfacial energy. The resulting emulsion is arrested, and the particle-coated interfaces have intriguing properties. Having made use of the binary-fluid phase diagram to create the emulsion we then make use of it to study the properties of the interfaces. As the emulsion is re-heated toward the single-fluid phase the interfacial tension falls and the volume of the dispersed phase drops. Crumpling, fracture or coalescence can follow. The results show that the elasticity of the interfaces has a controlling influence over the emulsion behaviour.Comment: Submitted for the proceedings of the 6th Liquid Matter Conference, held in Utrecht (NL) in July 200

Influência da temperatura no comportamento alimentar e interação de filhotes de Kinosternon scorpioides em cativeiro.

O muçuã (Kinosternon scorpioides) é um cágado bastante apreciado em toda a região amazônica, sendo um quelônio com características zootécnicas promissoras na aquicultura. Contudo, há poucos estudos que abordem o comportamento alimentar desta espécie em cativeiro. Portanto, objetivou-se com o presente estudo avaliar a influencia da temperatura no comportamento alimentar e a interação de filhotes de muçuã (Kinosternon scopioides), mantidos em três diferentes temperaturas (29,5ºC, 31,5ºC e 33,5ºC). O experimento foi conduzido no Projeto Bio-Fauna/ISARH/UFRA, sediado em Belém, Pará. Um total de 84 filhotes de muçuãs foram subdivididos em seis lotes-berçário, distribuídos dois a dois em estufas mantidas sob diferentes temperaturas, 29,5ºC, 31,5ºC e 33,5ºC, durante os primeiros 90 dias de vida. Os animais foram alimentados com ração para peixe, na proporção de 2% do peso vivo/dia, distribuída em ofertas semanais. Quinzenalmente foram realizadas pesagens e medições individuais, para avaliação do desenvolvimento corpóreo e ajuste de alimentação. Constatou-se efeito significativo da temperatura em todos os parâmetros analisados. Durante o experimento foi notado uma diminuição na frequência alimentar em todos os tratamentos, porém os animais da temperatura mais alta do experimento (33,5ºC) apresentaram a maior diminuição no interesse pelo alimento durante o período de oferta/observação, portanto os mesmos tiveram o pior desempenho quando comparado aos demais lotes

Mitigating Air Delay: An analysis of the Collaborative Trajectory Options Program

Congestion is a problem at major airports in the world. Airports, especially high-traffic ones, tend to be the bottleneck in the air traffic control system. The problem that arises for the airspace planner is how to mitigate air congestion and its consequent delay, which causes increased cost for airlines and discomfort for passengers. Most congestion problems are fixed on the day of operations in a tactically manner using operational enhancements measures. Collaborative Trajectory Options Program (CTOP) aims to improve air traffic management (ATM) considering National Airspace System (NAS) users business goals, particularities faced by each flight and airspace restrictions, making this process more flexible and financially stable for those involved. In CTOP, airlines share their route preferences with the air control authority, combining delay and reroute. When CTOP is created, each airline might decide its strategy without knowledge of other airline’s flights. Current solutions for this problem are based on greedy methods and game theory. There is potential space to improve. This paper examines CTOP and identifies important strategic changes to ATM adopting this philosophy, particularly in Brazil. Document type: Articl

OTIMIZAÇÃO DE PORTFÓLIOS: ANÁLISE DE EFICIÊNCIA

This article aims to analyze the behavior of a portfolio of assets selected by Data Envelopment Analysis (DEA), optimized by the Sharpe approach, and compare it to portfolios of assets obtained only by DEA or the Sharpe approach. To do that, we used the DEA model to assess the efficiency of shares of the São Paulo Stock Exchange (Bovespa), employing return, variance and other indicators such as input and output variables. Also, we used the Sharpe approach to optimize the portfolio composition. In the comparison of portfolios, we noted that the resulting combination of both models performed better than the portfolios optimized by only one of the models

Comparison of RANS and LES turbulent flow models in a real stenosis

This study focuses on the performance of various turbulence models in predicting hemodynamic variables within a patient-specific geometry of the Brachiocephalic trunk exhibiting a severe stenosis. Numerical simulations employing Reynolds-averaged Navier-Stokes (RANS) and Large Eddy Simulation (LES) models were conducted, comparing four RANS with two LES models. Results indicated significant differences in turbulent structures between RANS and LES models, with the k-ω RANS model closely approximating LES throughout the cardiac cycle. The velocity and Turbulent Kinetic Energy (TKE) results were consistent in the stenosis region due to the proximity to the inlet and plug flow conditions. However, notable disparities were observed in bifurcation and outlet regions. Time-Averaged Wall Shear Stress (TAWSS) comparisons revealed that the k-ω-based models provided closer agreement with LES, particularly in atherosclerosis-prone areas. The study highlights the limitations and strengths of each turbulence model, emphasizing the importance of model selection in simulating complex cardiovascular conditions. While RANS models demonstrated computational efficiency, their accuracy varied across regions. The effectiveness of the k-ω model in capturing the intricacies of such a complex flow field suggests its potential as a reliable and accurate tool for simulating physiological conditions with strong curvature and advanced stenosis.This work was developed with the aim of the doctoral grant SFRH/BD/144431/2019 and the projects UIDB/04436/2020, UIDB/04077/ 2020, funded by the Portuguese Foundation for Science and Technology (FCT). This work was partially funded by Junta de Extremadura through grant IB20105 (partially financed by FEDER). We thank the Programa Propio - Universidad Polit´ecnica de Madrid, and the Ayuda Primeros Proyectos de Investigacion ´ ETSII-UPM. We also thank Programa de Excelencia para el Profesorado Universitario de la Comunidad de Madrid for its financial support

Genome-wide transcriptional profiling of appressorium development by the rice blast fungus Magnaporthe oryzae.

addresses: College of Life and Environmental Sciences, University of Exeter, Exeter, United Kingdom.notes: PMCID: PMC3276559The rice blast fungus Magnaporthe oryzae is one of the most significant pathogens affecting global food security. To cause rice blast disease the fungus elaborates a specialised infection structure called an appressorium. Here, we report genome wide transcriptional profile analysis of appressorium development using next generation sequencing (NGS). We performed both RNA-Seq and High-Throughput SuperSAGE analysis to compare the utility of these procedures for identifying differential gene expression in M. oryzae. We then analysed global patterns of gene expression during appressorium development. We show evidence for large-scale gene expression changes, highlighting the role of autophagy, lipid metabolism and melanin biosynthesis in appressorium differentiation. We reveal the role of the Pmk1 MAP kinase as a key global regulator of appressorium-associated gene expression. We also provide evidence for differential expression of transporter-encoding gene families and specific high level expression of genes involved in quinate uptake and utilization, consistent with pathogen-mediated perturbation of host metabolism during plant infection. When considered together, these data provide a comprehensive high-resolution analysis of gene expression changes associated with cellular differentiation that will provide a key resource for understanding the biology of rice blast disease

Antifungal activity of the isolated from caatinga actinobacteria in control of Pythium aphanidermatum.

The Caatinga is a biome located in a semiarid region of northeastern Brazil. It consists of various ecosystems, presented a unique environmental system of this country. Because it is an environment with unique characteristics, recent studies have revealed the private wealth of this biome in terms of microbial biodiversity. Microorganisms found in this habitat may present specific mechanisms to ensure their survival in this environment that provides extreme conditions, such as temperature changes, intense solar radiation and hydrous stress. Because of these different mechanisms used by different microorganisms, becomes an enabling environment to search for new enzymes and bioactive substances produced by these organisms can present different biotechnological applications. Among all microbial diversity, the group of actinobacteria is of great importance, because they are responsible for producing most of the known antibiotics and present as great producers of enzymes with various industrial applications. One possible application of compounds produced by this organism is the phytogenic fungi combat, such as rot caused in roots of plants by the fungus Pythium aphanidermatum. This study aimed to search actinobacteria from Caatinga biome with metabolic potential to work in the biological control of Pythium aphanidermatum fungus. With Caatinga soil samples, they were isolated actinomycetes differences in morphologies and subjected to extraction metabolites produced from solid culture medium. The extracts were tested on the P. aphanidermatum fungus diffused by drive test. From the isolation were recovered a total of 272 strains of actinomycetes, of this total 47% of the isolates showed in vitro activity against the pathogen Pythium aphanidermatum. The results showing the great potential that actinobacteria may present as control agents against root rot. However, more detailed studies are needed to prove such results

Advanced glycoxidation and lipoxidation end products (AGEs and ALEs): an overview of their mechanisms of formation

Advanced lipoxidation end products (ALEs) and advanced glycation end products (AGEs) have a pathogenetic role in the development and progression of different oxidative-based diseases including diabetes, atherosclerosis, and neurological disorders. AGEs and ALEs represent a quite complex class of compounds that are formed by different mechanisms, by heterogeneous precursors and that can be formed either exogenously or endogenously. There is a wide interest in AGEs and ALEs involving different aspects of research which are essentially focused on set-up and application of analytical strategies (1) to identify, characterize, and quantify AGEs and ALEs in different pathophysiological conditions ; (2) to elucidate the molecular basis of their biological effects ; and (3) to discover compounds able to inhibit AGEs/ALEs damaging effects not only as biological tools aimed at validating AGEs/ALEs as drug target, but also as promising drugs. All the above-mentioned research stages require a clear picture of the chemical formation of AGEs/ALEs but this is not simple, due to the complex and heterogeneous pathways, involving different precursors and mechanisms. In view of this intricate scenario, the aim of the present review is to group the main AGEs and ALEs and to describe, for each of them, the precursors and mechanisms of formation

Mineralogical attenuation for metallic remediation in a passive system for mine water treatment

Passive systems with constructed wetlands have been consistently used to treat mine water from abandoned mines. Long-term and cost-effective remediation is a crucial expectation for these water treatment facilities. To achieve that, a complex chain of physical, chemical, biological, and mineralogical mechanisms for pollutants removal must be designed to simulate natural attenuation processes. This paper aims to present geochemical and mineralogical data obtained in a recently constructed passive system (from an abandoned mine, Jales, Northern Portugal). It shows the role of different solid materials in the retention of metals and arsenic, observed during the start-up period of the treatment plant. The mineralogical study focused on two types of materials: (1) the ochre-precipitates, formed as waste products from the neutralization process, and (2) the fine-grained minerals contained in the soil of the wetlands. The ochre-precipitates demonstrated to be poorly ordered iron-rich material, which gave rise to hematite upon artificial heating. The heating experiments also provided mineralogical evidence for the presence of an associated amorphous arsenic-rich compound. Chemical analysis on the freshly ochre-precipitates revealed high concentrations of arsenic (51,867 ppm) and metals, such as zinc (1,213 ppm) and manganese (821 ppm), indicating strong enrichment factors relative to the water from which they precipitate. Mineralogical data obtained in the soil of the wetlands indicate that chlorite, illite, chlorite–vermiculite and mica–vermiculite mixedlayers, vermiculite, kaolinite and goethite are concentrated in the fine-grained fractions (<20 and <2 μm). The chemical analyses show that high levels of arsenic (up to 3%) and metals are also retained in these fractions, which may be enhanced by the low degree of order of the clay minerals as suggested by an XRD study. The obtained results suggest that, although the treatment plant has been receiving water only since 2006, future performance will be strongly dependent on these identified mineralogical pollutant hosts.Fundação para a Ciência e a Tecnologia (FCT