162 research outputs found

    Investigating the effect of nanolime treatment on the drying kinetics of Clipsham limestone

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    Climate change poses an ever-increasing risk to our stone built heritage. Among conservation actions, the use of consolidant products is considered a possible response to this challenge, and the adoption of nanolimes has been widely studied showing promising results. However, while the effectiveness and method of application has been assessed, few studies have probed the changes in drying kinetics following treatment. In fact, a drastic alteration of the water transport might lead to further anomalies. This study investigates the influence of nanolimes dispersed in ethanol on the drying kinetics of Clipsham limestone using cavity ring-down spectroscopy. The degree of treatment was assessed by gravimetry, Raman spectroscopy, optical microscopy, colorimetry, optical profilometry and thin section analysis. Results showed an increase in the dry mass, observable colour changes and decrease in surface roughness. Small but reproducible increases were observed in the evaporation flux for phase I behaviour following treatment, however, no changes were observed in the total mass of water released or the phase II diffusivity. Determination of the activation energy associated with phase II drying was unchanged following treatment . These results indicate that following treatment there has been little-to-no change in the internal surfaces and structure of the stone to affect vapour transport

    Comprehensive analysis of Hox gene expression in the amphipod crustacean Parhyale hawaiensis.

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    Hox genes play crucial roles in establishing regional identity along the anterior-posterior axis in bilaterian animals, and have been implicated in generating morphological diversity throughout evolution. Here we report the identification, expression, and initial genomic characterization of the complete set of Hox genes from the amphipod crustacean Parhyale hawaiensis. Parhyale is an emerging model system that is amenable to experimental manipulations and evolutionary comparisons among the arthropods. Our analyses indicate that the Parhyale genome contains a single copy of each canonical Hox gene with the exception of fushi tarazu, and preliminary mapping suggests that at least some of these genes are clustered together in the genome. With few exceptions, Parhyale Hox genes exhibit both temporal and spatial colinearity, and expression boundaries correlate with morphological differences between segments and their associated appendages. This work represents the most comprehensive analysis of Hox gene expression in a crustacean to date, and provides a foundation for functional studies aimed at elucidating the role of Hox genes in arthropod development and evolution

    Follicular fluid high density lipoprotein-associated micronutrient levels are associated with embryo fragmentation during IVF

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    To investigate whether follicular fluid lipid-soluble micronutrients are associated with embryo morphology parameters during IVF. Follicle fluid and oocytes were obtained prospectively from 81 women. Embryo morphology parameters were used as surrogate markers of oocyte health. HDL lipids and lipid-soluble micronutrients were analyzed by high-pressure liquid chromatography. Non-parametric bi-variate analysis and multivariable ordinal logistic regression models were employed to examine associations between biochemical and embryo morphology parameters. Follicular fluid HDL cholesterol (r = −0.47, p < 0.01), α-tocopherol (r = −0.41, p < 0.01), δ-tocopherol (r = −0.38, p < 0.05) and β-cryptoxanthine (r = −0.42, p < 0.01) are negatively correlated with embryo fragmentation. Ordinal logistic regression models indicate that a 0.1 μmol/L increase in β-cryptoxanthine, adjusted for γ-tocopherol, is associated with a 75% decrease in the cumulative odds of higher embryo fragmentation (p = 0.010). Follicular fluid HDL micronutrients may play an important role in the development of the human oocyte as evident by embryo fragmentation during IVF
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