264 research outputs found

    Enhancement in Electro-Optic Properties of Dynamic Scattering Systems through Addition of Dichroic Dyes

    Full text link
    Electro-optic properties of dynamic scattering in homeotropically aligned pure and dichroic dye-doped nematic liquid crystal samples are examined. The optical properties of the two systems are quantified using transmission properties of scattered and unscattered as a function of amplitude and frequency of an applied voltage. Auto-correlation of the scattered signal at different applied voltages is used to compare the decay times in the two systems. Lastly, the histogram of the scattered signal reveals a wavevector dependent large light scattering event. The dye-doped system shows a significant enhancement of light blocking property in both normal and off-axis light propagation. The characteristics of the system are compared to other scattering technologies. The results suggest that dye-doped system can overcome shortcomings in scattering based devices used for near-eye applications

    Consumer Perceptions of Labels and the Willingness to Pay for “Second Generation” Genetically Modified Products

    Get PDF
    Environmental and consumer groups have called for mandatory labeling of genetically modified (GM) food products in the United States, stating that consumers have the “right to know.” But evidence exists suggesting that consumers often cannot correctly interpret the meaning of scientific labels. Herein we use a nonhypothetical field experiment to examine how well consumers interpret GM labels, focusing on the solitary secondgeneration GM product currently on the U.S. market—GM cigarettes. Our results suggest that while consumers pay less for GM cigarettes when they are labeled as GM, these labels seem to be misinforming consumers. This evidence implies that consumers could be better off without mandatory GM labeling

    Estimation du sexe fœtal à partir de l’ilium

    Get PDF
    La détermination du sexe est une des problématiques les plus fréquemment rencontrées en anthropologie médico-légale. Chez l’adulte, cette détermination est essentiellement basée sur l’os iliaque et autorise un très fort taux de classification correcte, tandis que chez le fœtus, les études sont beaucoup moins nombreuses et conduisent à des résultats souvent contradictoires.Nous avons recherché sur 83 paires d’ilia fœtaux de la collection ostéologique hongroise de Fazekas et Kosa quels étaient les critères métriques qui décrivaient le mieux le dimorphisme sexuel, en évaluant les différentes méthodes proposées sur l’ilium fœtal et en adaptant certaines de celles proposées chez l’adulte. Nous avons pour cela établi et validé un protocole de prise de clichés photographiques et une méthode de mesure sur image numérisée à partir du logiciel Adobe Photoshop 6‚.Certains des paramètres retenus dans l’étude – principalement ceux qui ont été relevés sur l’échancrure ischiatique – présentant de fortes corrélations avec le sexe, nous avons établi une régression logistique estimant la probabilité d’appartenir à l’un ou l’autre des deux sexes. Le faible pourcentage de discrimination sexuelle obtenu avec cette formule nous a amené à tenir compte de l’âge : nous avons donc structuré notre échantillon en différents groupes d’âge et avons établi une formule permettant de déterminer correctement le sexe dans plus de 85 % des cas (sur l’échantillon qui a servi à l’établir) pour les fœtus dont l’âge est inférieur à 26 semaines d’aménorrhée.Sex estimation is one of the most frequently encountered issues in forensic medicine. While in the case of adults this determination is essentially based on iliac bones and provides a rather reliable classification, there are fewer studies conducted on fetuses and the results are often contradictory.Therefore, we examinated 83 pairs of fetal iliac bones in the Hungarian collection of Fazekas and Kosa and searched for metric criteria that can the best be applied for determining sexual dimorphism. During this research, we tested the different methods proposed for fetal iliac bones and adapted some others used particularly in the case of adults.For this reason, we set up and validated a protocol of taking photographs, as well as a measurement technique developed for numeric pictures with the help of a software program, Adobe Photoshop 6‚.During this study, we selected certain parameters, principally the ones taken on the great sciatic notch, which showed a strong correlation with sex, and we established a logistic regression for estimating the probability of belonging to one sex or the other.The weak percentage of sexual differentiation obtained by this formula led us to take into account age: we organised our sample in different age groups and established a formula that permits correct sex determination in more than 85% of cases (in our sample) for fetuses that are less than 24 gestational weeks old

    Rhodococcus opacus B4: a promising bacterium for production of biofuels and biobased chemicals

    Get PDF
    Bacterial lipids have relevant applications in the production of renewable fuels and biobased oleochemicals. The genus Rhodococcus is one of the most relevant lipid producers due to its capability to accumulate those compounds, mainly triacylglycerols (TAG), when cultivated on different defined substrates, namely sugars, organic acids and hydrocarbons but also on complex carbon sources present in industrial wastes. In this work, the production of storage lipids by Rhodococcus opacus B4 using glucose, acetate and hexadecane is reported for the first time and its productivity compared with Rhodococcus opacus PD630, the best TAG producer bacterium reported. Both strains accumulated mainly TAG from all carbon sources, being influenced by the carbon source itself and by the duration of the accumulation period. R. opacus B4 produced 0.09 and 0.14 g L1 at 24 and 72 h, with hexadecane as carbon source, which was 2 and 3.3 fold higher than the volumetric production obtained by R. opacus PD630. Both strains presented similar fatty acids (FA) profiles in intact cells while in TAG produced fraction, R. opacus B4 revealed a higher variability in fatty acid composition than R. opacus PD630, when both strains were cultivated on hexadecane. The obtained results open new perspectives for the use of R. opacus B4 to produce TAG, in particular using oily (alkane-contaminated) waste and wastewater as cheap raw-materials. Combining TAG production with hydrocarbons degradation is a promising strategy to achieve environmental remediation while producing added value compounds.This work was financially supported by the Portuguese Science Foundation (FCT) and European Social Fund (ESF, POPH-QREN) through the Grant given to A.R. Castro (SFRH/BD/64500/2009), the FCT Strategic Project of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462)

    Regional socioeconomic indicators and ethnicity as predictors of regional infant mortality rate in Slovakia

    Get PDF
    OBJECTIVE: Exploring the associations of regional differences in infant mortality with selected socioeconomic indicators and ethnicity could offer important clues for designing public health policy measures. METHODS: Data included perinatal and infant mortality in the 79 districts of the Slovak population in 2004. Linear regression was used to analyse the contribution of education, unemployment, income and proportion of Roma population on regional differences in perinatal and infant mortality rates. RESULTS: All the explored socioeconomic indicators and ethnicity individually contributed significantly to both perinatal and infant mortality, with the exception of income. In the model exploring the influence of all these variables together on perinatal and infant mortality, only the effect of the proportion of Roma population remained significant. This model explained 34.9% of the variance for perinatal and 36.4% of the variance for infant mortality. CONCLUSIONS: Living in Roma settlements indicates an accumulation of socioeconomic disadvantage. Health literacy, health-related behaviour and many other factors might contribute to the explanation of the differences in infant mortality, and a better understanding of these processes might help us to design tailored interventions
    corecore