19 resultados para Man Ray, 1890-1976 -- Criticism and interpretation
em CentAUR: Central Archive University of Reading - UK
Resumo:
Using bis(3,5-dimethylpyrazol-1-yl) methane as the bidentate N donor ligand L, the yellow compound trans-[(RuL2)-L-III(OMe)(2)]ClO4 center dot CH2Cl2 is synthesized. It is a rare example of a mononuclear dialkoxo complex of Ru(III). It shows a quasireversible Ru(II/III) couple at -0.65 V versus NHE in acetonitrile at a Pt electrode. Its magnetic moment at room temperature corresponds to one unpaired electron. It displays a rhombic EPR spectrum in acetone at 77 K with g = 2.219, 2.062 and 1.855. (C) 2009 Elsevier B. V. All rights reserved.
Resumo:
The diagnosis of thalassaemia in archaeological populations has long been hindered by a lack of pathogonomic features, and the non-specific nature of cribra orbitalia and porotic hyperostosis. In fact, clinical research has highlighted more specific diagnostic criteria for thalassaemia major and intermedia based on changes to the thorax (‘rib-within-a-rib’ and costal osteomas). A recent re-examination of 364 child skeletons from Romano-British Poundbury Camp, Dorset revealed children with general ‘wasting’ of the bones and three children who demonstrated a variety of severe lesions (e.g. zygomatic bone and rib hypertrophy, porotic hyperostosis, rib lesions, osteopenia and pitted diaphyseal shafts) that are inconsistent with dietary deficiency alone, and more consistent with a diagnosis of genetic anaemia. Two of these children displayed rib lesions typical of those seen in modern cases of thalassaemia. The children of Poundbury Camp represent the first cases of genetic anaemia identified in a British archaeological population. As thalassaemia is a condition strongly linked to Mediterranean communities, the presence of this condition in a child from England, found within a mausoleum, suggests that they were born to wealthy immigrant parents living in this small Roman settlement in Dorset. This paper explores the diagnostic criteria for genetic anaemia in the archaeological literature and what its presence in ancient populations can contribute to our knowledge of past human migration.
Resumo:
The effects of nano-scale and micro-scale zerovalent iron (nZVI and mZVI) particles on general (dehydrogenase and hydrolase) and specific (ammonia oxidation potential, AOP) activities mediated by the microbial community in an uncontaminated soil were examined. nZVI (diameter 12.5 nm; 10 mg gÿ1 soil)apparently inhibited AOP and nZVI and mZVI apparently stimulated dehydrogenase activity but had minimal influence on hydrolase activity. Sterile experiments revealed that the apparent inhibition of AOP could not be interpreted as such due to the confounding action of the particles, whereas, the nZVIenhanced dehydrogenase activity could represent the genuine response of a stimulated microbial population or an artifact of ZVI reactivity. Overall, there was no evidence for negative effects of nZVI or mZVI on the processes studied. When examining the impact of redox active particles such as ZVI on microbial oxidation–reduction reactions, potential confounding effects of the test particles on assay conditions should be considered.
Resumo:
The wide angle X-ray scattering from glassy poly(2-hydroxyethyl methacrylate) (1) is presented together with that obtained from oriented and swollen samples. The scattering is compared with that previously reported for poly(methyl methacrylate) (PMMA) and the structure discussed in relation to this polymer. The chain conformation is similar to that of PMMA, although some measure of molecular interlocking appears to reduce the main interchain peak while correlated regions of inaccessible free volume between the substantial side groups are held responsible for the main peak at s = 1,25 Å−1.
Resumo:
In vitro fermentation techniques (IVFT) have been widely used to evaluate the nutritivevalue of feeds for ruminants and in the last decade to assess the effect of different nutritionalstrategies on methane (CH4) production. However, many technical factors may influencethe results obtained. The present review has been prepared by the ‘Global Network’ FACCE-JPI international research consortium to provide a critical evaluation of the main factorsthat need to be considered when designing, conducting and interpreting IVFT experimentsthat investigate nutritional strategies to mitigate CH4emission from ruminants. Given theincreasing and wide-scale use of IVFT, there is a need to critically review reports in the lit-erature and establish what criteria are essential to the establishment and implementationof in vitro techniques. Key aspects considered include: i) donor animal species and numberof animal used, ii) diet fed to donor animals, iii) collection and processing of rumen fluidas inoculum, iv) choice of substrate and incubation buffer, v) incubation procedures andCH4measurements, vi) headspace gas composition and vii) comparability of in vitro andin vivo measurements. Based on an evaluation of experimental evidence, a set of techni-cal recommendations are presented to harmonize IVFT for feed evaluation, assessment ofrumen function and CH4production.