Aroma characterization of ripe date fruits (Phoemix dactylifera L.) from Algeria

The headspace of eight Algerian date varieties with low market value were analyzed for their aroma compounds using solid phase micro extraction and gas chromatography combined with mass spectrometry. In this study, 61 identified compounds were categorized in various chemical classes on the basis of their functional groups, alcohols, esters, aldehydes, terpenoids, ketones, hydrocarbons, and ethers. Twenty specific volatiles were found to be representative of a single variety and four shared molecules were exclusively observed in all the studied dates. Some dates such as Bent Qbala, Litima, and Timjouhart were statistically different from the other varieties which presented on the contrary a significant similarity between them. In the present study, forty eight new volatile compounds were identified which could be useful for the characterization of the Algerian date

Influence of maternal alimentation on outcome of pregnancy at Constantine (Algeria)

International audienc

Two-agent scheduling with agent specific batches on an unbounded serial batching machine

International audienc

Desenvolvimento de um modelo para o biospeckle na análise de sementes de feijão (Phaseolus vulgaris L.) Development of a model for the biospeckle applied to analise been seed (Phaseolus vulgaris L.)

O biospeckle é uma figura de interferência formada pela reflexão difusa da luz coerente espalhada ao interagir com um objeto que apresenta algum tipo de atividade, biológica ou não. O padrão de interferência se modifica ao longo do tempo devido às estruturas responsáveis pelo espalhamento estarem em atividade. Esse fenômeno tem sido estudado com o intuito de se desenvolver um método rápido e não destrutivo para avaliação de materiais biológicos. A obtenção de um modelo simples que descreva os aspectos essenciais do fenômeno é um importante passo para o domínio da técnica. Neste trabalho é apresentado um modelo para descrever a formação do biospeckle, desenvolvido a partir de hipóteses simples sobre como o tecido biológico difrata a luz coerente e qual o efeito da atividade biológica sobre a difração. Foram comparados os resultados da simulação do modelo com resultados experimentais obtidos de sementes. O modelo reproduz com sucesso algumas das características básicas do padrão dinâmico.<br>Biospeckle is an interference pattern phenomenon formed by the diffuse reflection of coherent light scattered by any type of activity, biological or not. The interference pattern changes in time due to the movement of the structures that scatter the light. This phenomenon has been studied with the goal of developing a fast and non-destructive method for evaluating biological material. Building a simple model that describes the essential aspects of the phenomenon is an important step towards the development of this technique. In this work is presented a model that describes the formation of the biospeckle, based on simple assumptions about the scattering of coherent light by the biological material and the nature of biological activity. We compare the results provided by the model with experimental biospeckle obtained from seeds. The model reproduces successfully some of the basic characteristics of the dynamical experimental pattern

Laser Doppler, speckle and related techniques for blood perfusion mapping and imaging

Laser Doppler velocimetry uses the frequency shift produced by the Doppler effect to measure velocity. It can be used to monitor blood flow or other tissue movement in the body. Laser speckle is a random interference effect that gives a grainy appearance to objects illuminated by laser light. If the object consists of individual moving scatterers (such as blood cells), the speckle pattern fluctuates. These fluctuations provide information about the velocity distribution of the scatterers. It can be shown that the speckle and Doppler approaches are different ways of looking at the same phenomenon. Both these techniques measure at a single point. If a map of the velocity distribution is required, some form of scanning must be introduced. This has been done for both time-varying speckle and laser Doppler. However, with the speckle technique it is also possible to devise a full-field technique that gives an instantaneous map of velocities in real time. This review article presents the theory and practice of these techniques using a tutorial approach and compares the relative merits of the scanning and full-field approaches to velocity map imaging. The article concludes with a review of reported applications of these techniques to blood perfusion mapping and imaging