Reflections on spirituality : English academic writing for non native students

研究ノート (Note

Expression patterns of chondrocyte genes cloned by differential display in tibial dyschondroplasia

AbstractTibial dyschondroplasia (TD) appears to involve a failure of the growth plate chondrocytes within growing long bones to differentiate fully to the hypertrophic stage, resulting in a mass of prehypertrophic chondrocytes which form the avascular TD lesion. Many biochemical and molecular markers of chondrocyte hypertrophy are absent from the lesion, or show reduced expression, but the cause of the disorder remains to be identified. As differentiation to the hypertrophic state is impaired in TD, we hypothesised that chondrocyte genes that are differentially expressed in the growth plate should show altered expression in TD. Using differential display, four genes, B-cadherin, EF2, HT7 and Ex-FABP were cloned from chondrocytes stimulated to differentiate to the hypertrophic stage in vitro, and their differential expression confirmed in vivo. Using semi-quantitative RT-PCR, the expression patterns of these genes were compared in chondrocytes from normal and TD growth plates. Surprisingly, none of these genes showed the pattern of expression that might be expected in TD lesion chondrocytes, and two of them, B-cadherin and Ex-FABP, were upregulated in the lesion. This indicates that the TD phenotype does not merely reflect the absence of hypertrophic marker genes, but may be influenced by more complex developmental mechanisms/defects than previously thought

Carbon isotope ratios of Sterkfontein fossils indicate a marked shift to open environments c.1.7 Myr ago

Sterkfontein straddles a period in the Plio-Pleistocene in which the effects of global-scale climate shifts on continental environments and biota are not yet well understood. Reconstructions based on faunal indicators have suggested incremental shifts from relatively closed, mesic landscapes to open, arid environments at this time. We examined environmental shifts from ~2.5 to 1.7 million years ago (Myr) using a C3 / C4 index derived from 13C / 12C data on bovid fossils from Sterkfontein. Data for Member 4 and the Member 5 East infill indicate persistence of a wooded to moderately wooded environment until about 2.0-1.8 Myr. Data indicating a marked shift to open environments are observed only for the younger Member 5 West infill. We conclude that the major shift to open environments occurred near 1.7 Myr rather than at c. 2.5 Myr

Oxidation of guanines in the iron-responsive element RNA: similar structures from chemical modification and recent NMR studies

AbstractBackground: The translation or stability of the mRNAs from ferritin, m-aconitase, erythroid aminoevulinate synthase and the transferrin receptor is controlled by the binding of two iron regulatory proteins to a family of hairpin-forming RNA sequences called iron-responsive elements (IREs). The determination of higher-solution nuclear magnetic resonance (NMR) structures of IRE variants suggests an unusual hexaloop structure, leading to an intra-loop G-C base pair and a highly exposed loop guanine, and a special internal loop/bulge in the ferritin IRE involving a shift in base pairing not predicted with standard algorithms.Results: Cleavage of synthetic 55- and 30-mer RNA oligonucleotides corresponding to the ferritin IRE with complexes based on oxoruthenium(IV) shows enhanced reactivity at a hexaloop guanine and at a guanine adjacent to the internal loop/bulge with strong protection at a guanine in the internal loop/bulge. These results are consistent with the recent NMR structures. The synthetic 55-mer RNA binds the iron-regulatory protein from rabbit reticulocyte lysates. The DNA analogs of the 55- and 30-mers do not show the same reactivity pattern.Conclusions: The chemical reactivity of the guanines in the ferritin IRE towards oxoruthenium(IV) supports the published NMR structures and the known oxidation chemistry of the metal complexes, The results constitute progress towards developing stand-alone chemical nucleases that reveal significant structural properties and provide results that can ultimately be used to constrain molecular modeling

Using scenarios to explore UK upland futures

Uplands around the world are facing significant social, economic and environmental changes, and decision-makers need to better understand what the future may hold if they are to adapt and maintain upland goods and services. This paper draws together all major research comprising eight studies that have used scenarios to describe possible futures for UK uplands. The paper evaluates which scenarios are perceived by stakeholders to be most likely and desirable, and assesses the benefits and drawbacks of the scenario methods used in UK uplands to date. Stakeholders agreed that the most desirable and likely scenario would be a continuation of hill farming (albeit at reduced levels) based on cross-compliance with environmental measures. The least desirable scenario is a withdrawal of government financial support for hill farming. Although this was deemed by stakeholders to be the least likely scenario, the loss of government support warrants close attention due to its potential implications for the local economy. Stakeholders noted that the environmental implications of this scenario are much less clear-cut. As such, there is an urgent need to understand the full implications of this scenario, so that upland stakeholders can adequately prepare, and policy-makers can better evaluate the likely implications of different policy options. The paper concludes that in future, upland scenario research needs to: (1) better integrate in-depth and representative participation from stakeholders during both scenario development and evaluation; and (2) make more effective use of visualisation techniques and simulation models