Variational calculations for K-few-nucleon systems

Deeply bound KNN, KNNN and KNNNN states are discussed. The effective force exerted by the K meson on the nucleons is calculated with static nucleons. Next the binding energies are obtained by solving the Schrodinger equation or by variational calculations. The dominant attraction comes from the S-wave Lambda(1405) and an additional contribution is due to Sigma(1385). The latter state is formed at the nuclear peripheries and absorbs a sizable piece of the binding energy. It also generates new branches of quasi-bound states. The lowest binding energies based on a phenomenological KN input fall into the 40-80 MeV range for KNN, 90-150 MeV for KNNN and 120-220 MeV for K-alpha systems. The uncertainties are due to unknown KN interactions in the distant subthreshold energy region.Comment: 19 pages, 1 figur

Epidemiologic studies on short-term effects of low levels of major ambient air pollution components.

Since the development of the World Health Organization (WHO) Air Quality Guidelines for Europe, a large number of epidemiologic studies have been published documenting effects of major air pollutants on health at concentrations below existing guidelines and standards. In this review, recent studies are discussed that permit some evaluation of short-term health effects observed at exposure levels lower than the current WHO Guidelines or U.S. Environmental Protection Agency (U.S. EPA) standards. Some studies have been conducted at concentration levels that never exceeded existing guidelines or standards. Other studies have been conducted at exposure levels sometimes exceeding current guidelines or standards. The published analyses of several of these studies permit evaluation of low-level health effects either because analyses were restricted to levels not exceeding the guidelines or graphic analyses were reported suggesting effects at these low levels. For ambient ozone, effects on lung function of subjects exercising outdoors have now been documented at 1-hr maximum levels not exceeding 120 micrograms/m3, i.e., half the current U.S. EPA standard. One study even suggests that such effects occur at levels below 100 micrograms/m3. Several studies are now available documenting effects of particulate air pollution on health in the virtual absence of SO2. Effects on mortality and hospital admissions for asthma have been documented at levels not exceeding 100 micrograms/m3, expressed as 24-hr average inhalable particles PM10 concentration. Effects on lung function, acute respiratory symptoms, and medication use have been found at 24-hr average PM10 levels not exceeding 115 micrograms/m3. When the WHO Air Quality Guidelines and the U.S. EPA standard for PM10 were developed, there were no studies available on health effects of PM10. In this review, we include nine studies documenting health effects of measured PM10 at low levels of exposure, indicating that there is now an entirely new epidemiologic database that can be evaluated in the process of revising current guidelines and standards. The low levels of exposure at which effects on health were seen underscore the urgent need for such reevaluations

Análise de lignina com diferentes massas de tegumento de soja utilizando método gravimétrico.

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Área do dano causado pelo percevejo marrom em sementes de soja com diferentes porcentagens de lignina.

A lignina no tegumento das sementes de soja reduz a incidência de danos mecânicos durante a colheita. Todavia, pouco se conhece sobre seu efeito na alimentação dos percevejos. O objetivo dos experimentos foi avaliar a área do dano causado pelo percevejo marrom, Euschistus heros, na fase adulta, em sementes de soja contendo diferentes porcentagens de lignina, em laboratório e em casa de vegetação. Em laboratório, foram usadas sementes de soja dos cultivares Doko (6,20% de lignina), BRS-255 RR (5,09%), BRS-284 (3,15%) e BRS-232 (1,65%) hidratadas por 16 h, e submetidas individualmente ao ataque do percevejo, em delineamento inteiramente casualizado com quatro repetições (50 sementes/repetição). A atividade dos insetos foi monitorada durante seis horas, para registro do tempo de alimentação e da quantidade de insetos que atacaram as sementes. As sementes atacadas foram submetidas ao teste de tetrazólio para a obtenção de imagens fotográficas do dano causado pelos percevejos, e posterior medição da área danificada no programa Photop (IAPAR). Em casa de vegetação, legumes de cada cultivar no estágio R5/R6 foram individualizados no interior de gaiolas contendo um percevejo. Foram utilizadas cinco plantas por cultivar, com cada planta contendo quatro gaiolas. As vagens ficaram disponíveis ao ataque dos insetos durante 48 horas. As sementes foram colhidas após a secagem natural das plantas, e submetidas ao teste de tetrazólio para obtenção de imagens fotográficas dos danos causados pelos percevejos em 30 sementes por cultivar, para medição das áreas dos danos. As sementes de cultivares com menor porcentagem de lignina no tegumento apresentaram áreas de danos significativamente maiores (Tukey, P?0,05) que as com maiores porcentagens de lignina

Application of Cellular Automata and Lattice Boltzmann Methods for modelling of Additive Layer Manufacturing

Purpose - The holistic numerical model based on cellular automata (CA) and Lattice Boltmann Methods (LBM) is being developed as part of an integrated modelling approach applied to study the interaction of different physical mechanisms in laser assisted additive layer manufacturing (ALM) of orthopaedic implants. Several physical events occuring in sequence or simultaneously are considered in the holistic model. They include a powder bed deposition, laser energy absorption and heating of the powder bed by the moving laser beam leading to powder melting or sintering, fluid flow in the melted pool, flow through partly or not melted material and solidification. Design/methodology/approach - The mentioned physical events are accompanied by heat transfer in solid and liquid phases including interface heat transfer at the boundaries. The sintering/melting model is being developed using LBM as an independent numerical method for hydrodynamic simulations originated from lattice-gas cellular automata (LGCA). It is going to be coupled with the CA based model of powder bed generation. Findings - The entire laser assisted ALM process has been analised and divided on several stages considering the relevant physical phenomema. The entire holistic model consisting of four interrelated submodels has currently been developed to a different extent. The submodels include the CA based model of powder bed generation, the LBM-CA based model of heat exchange and transfer, the thermal solid-liquid interface model and the mechanical solid-liquid interface model for continuous liquid flow. Practical implications – The results obtained can be used to explain the interaction of the different physical mechanisms in ALM, which is intensively developing field of advanced manufacturing of metal, non-metal and composite structural parts for instance in bio-engineering among others. The proposed holistic model is considered to be a part of the integrated modelling approach being developed as a numerical tool for investigation of the co-operative relashionships between multiphysical phenomena occurred in sequence or simultaneousely during heating of the power bed by the moving moving high energy heat source leading to selective powder sintering or melting, fluid flow in the melted pool and through partly (or not) melted material and also to solidification. The model is compatible with the earlier developed CA based model for generation of the powder bed allowing for decrease of the numerical noise. Originality/Value - The present results are original and new for the study of the complex relathionships between multifysical phenomena occurring during ALM process based on selective laser sintering or melting (SLS/SLM) including fluid flow and heat transfer among others identified as crucial for obtaining the desirable properties

Using a Robust and Sensitive GFP-Based cGMP Sensor for Real-Time Imaging in Intact Caenorhabditis elegans.

cGMP plays a role in sensory signaling and plasticity by regulating ion channels, phosphodiesterases, and kinases. Studies that primarily used genetic and biochemical tools suggest that cGMP is spatiotemporally regulated in multiple sensory modalities. FRET- and GFP-based cGMP sensors were developed to visualize cGMP in primary cell culture and Caenorhabditis elegans to corroborate these findings. While a FRET-based sensor has been used in an intact animal to visualize cGMP, the requirement of a multiple emission system limits its ability to be used on its own as well as with other fluorophores. Here, we demonstrate that a C. elegans codon-optimized version of the cpEGFP-based cGMP sensor FlincG3 can be used to visualize rapidly changing cGMP levels in living, behaving C. elegans We coexpressed FlincG3 with the blue-light-activated guanylyl cyclases BeCyclOp and bPGC in body wall muscles, and found that the rate of change in FlincG3 fluorescence correlated with the rate of cGMP production by each cyclase. Furthermore, we show that FlincG3 responds to cultivation temperature, NaCl concentration changes, and sodium dodecyl sulfate in the sensory neurons AFD, ASEL/R, and PHB, respectively. Intriguingly, FlincG3 fluorescence in ASEL and ASER decreased in response to a NaCl concentration upstep and downstep, respectively, which is opposite in sign to the coexpressed calcium sensor jRGECO1a and previously published calcium recordings. These results illustrate that FlincG3 can be used to report rapidly changing cGMP levels in an intact animal, and that the reporter can potentially reveal unexpected spatiotemporal landscapes of cGMP in response to stimuli