Laser ablation of Diamond and Genesis concentrator target material

UV laser ablations of CVD diamond using two wavelengths of radiation (266 nm and 213 nm) have been compared. The impetus for this work is the 2004 return of Genesis and extraction of solar-wind oxygen implanted in diamond

Surface enhancement of oxygen exchange and diffusion in the ionic conductor La2Mo2O9

Isotopic surface oxygen exchange and its subsequent diffusion have been measured using secondary ion mass spectrometry in the fast ionic conductor La2Mo2O9. A silver coating was applied to the sample surface to enhance the surface exchange process for dry oxygen. Contrary to previous studies performed using a wet atmosphere, no grain boundary diffusion tail was observed under these optimized dry exchange conditions. The activation energy for oxygen diffusion was found to be 0.66(+/- 0.09) eV at high temperature (>570 degrees C), and 1.25(+/- 0.01)eV at low temperature (<570 degrees C). Time-of-Flight secondary ion mass spectrometry was employed to investigate the correlation between the silver coating and the O-18 concentration on the sample surface. A close correlation between the presence of silver and oxygen incorporation on the surface was observed. (C) 2010 Elsevier B.V. All rights reserved

Elaboration, caractérisation et comportement à l’oxydation haute température des nanomatériaux Fe1-x Alx obtenus par mécanosynthèse

Actuellement, les recherches s'orientent vers la production de matériaux pour lesquels les futures propriétés pourraient être contrôlées par la maîtrise de la microstructure. A ce sujet, nous utiliserons dans ce travail le procédé d'élaboration par mécano synthèse. Nous avons choisi de synthétiser les composés intermétalliques du système Fe&lt;sub&gt;1-x&lt;/sub&gt; Al&lt;sub&gt;x&lt;/sub&gt; (x=20, 35, 50 %) et d‟étudier leur comportement à l‟oxydation haute température. Le broyage à haute énergie a permis d‟élaborer, à partir de métaux purs, des mélanges homogènes et nanostructurés. Les conditions de broyage utilisées conduisent à la formation d‟une phase homogène après 7h de broyage et cela quelle que soit la composition du mélange initial. La caractérisation des poudres a été réalisée par la microscopie électronique à balayage (MEB) et la diffraction des rayons X (DRX). Nous avons effectué des essais d‟oxydation à haute température sur trois alliages binaires FeAl à 1 000 °C, dans une atmosphère d'air de laboratoire et à pression atmosphérique. Les essais d‟oxydation menés à 1000 °C présentent deux stades : un premier stade transitoire avec une cinétique à croissance rapide liée à la présence des alumines métastables et un deuxième stade stationnaire associé à la croissance de l‟alumine. Le taux d‟oxydation diminue avec l‟augmentation de la teneur en Al.Mots clés: Alliage Fe -Al- Mécanosynthèse – Nanomatériaux - oxydation haute températur

Replacing sugary snacks with fruit, nuts and seeds at nurses’ stations within a uk oncology unit: A pilot intervention study

Aim-This real-world service intervention study evaluated NHS staff weight and subjective happiness over a three-month period, by replacing processed, sugary foodstuffs with fruit, nuts and seeds. Method-Forty four staff at the Primrose Oncology Unit, Bedford Hospital, volunteered to abstain from cakes, biscuits, sweets, sugary drinks and chocolates whilst at work between June 2019 and September 2019. Participants’ weight and subjective happiness scores were recorded at baseline, three months (completion) and five months (post-completion). Fresh and dried fruit, and bags of raw nuts and seeds were made available to all staff (including those not participating). Participants resumed their usual diet outside of working hours. One hundred consecutive patients attending the department during the intervention were asked whether removing sugary food from public view was a positive move and whether it would have a likely influence on their future eating habits. Results-At five months, twenty (46%) participants lost weight >1kg (average 3.01 kg), seven participants gained >1kg (average 2.23 kg), and 17 remained the same weight (T-test p1kg weight, average happiness score increased from 21.54 to 23.75 (+9.3%), p1 kg weight, average happiness score decreased from 22.28 to 21.43 (-3.8%), p1kg compared to those gaining >1kg in weight p< 0.001). 94 (94%) patients indicated that this initiative gave a good impression and ninety seven (97%) indicated that the initiative would encourage them to reduce sugar in their own diet. Conclusion-The results demonstrated a statistically significant reduction in weight loss and increase in mood in just under half of the participants. Whilst this level of weight loss was similar to the best designed weight loss programmes, a larger study is required to validate these results

Evolution in a Changing Environment

We propose a simple model for genetic adaptation to a changing environment, describing a fitness landscape characterized by two maxima. One is associated with “specialist” individuals that are adapted to the environment; this maximum moves over time as the environment changes. The other maximum is static, and represents “generalist” individuals not affected by environmental changes. The rest of the landscape is occupied by “maladapted” individuals. Our analysis considers the evolution of these three subpopulations. Our main result is that, in presence of a sufficiently stable environmental feature, as in the case of an unchanging aspect of a physical habitat, specialists can dominate the population. By contrast, rapidly changing environmental features, such as language or cultural habits, are a moving target for the genes; here, generalists dominate, because the best evolutionary strategy is to adopt neutral alleles not specialized for any specific environment. The model we propose is based on simple assumptions about evolutionary dynamics and describes all possible scenarios in a non-trivial phase diagram. The approach provides a general framework to address such fundamental issues as the Baldwin effect, the biological basis for language, or the ecological consequences of a rapid climate change

A decade of Australian Rural Clinical School graduates: Where are they and why?

Introduction: The Australian Rural Clinical School (RCS) initiative has been addressing the rural medical workforce shortage at the medical education level for over a decade. A major expectation of this initiative is that it will improve rural medical workforce recruitment and subsequent retention through a rurally based undergraduate clinical training experience. The longitudinal nature of these workforce initiatives means that definitive evidence of its impact on the shortage of rural doctors is yet to be provided; however, to date cross-sectional studies are accumulating a measure of efficacy for these initiatives by monitoring early career factors such as internship location choice and speciality choice of RCS graduates. This article reports on a study in one RCS that is monitoring the impact of rural undergraduate clinical training on trends in workforce participation patterns of its graduates as long as 9 years in the workforce. Career location and speciality choice are reported as well as perspectives on early career intentions and the reality of making career and life decisions as a doctor in the medical workforce

The biological origin of linguistic diversity

In contrast with animal communication systems, diversity is characteristic of almost every aspect of human language. Languages variously employ tones, clicks, or manual signs to signal differences in meaning; some languages lack the noun-verb distinction (e.g., Straits Salish), whereas others have a proliferation of fine-grained syntactic categories (e.g., Tzeltal); and some languages do without morphology (e.g., Mandarin), while others pack a whole sentence into a single word (e.g., Cayuga). A challenge for evolutionary biology is to reconcile the diversity of languages with the high degree of biological uniformity of their speakers. Here, we model processes of language change and geographical dispersion and find a consistent pressure for flexible learning, irrespective of the language being spoken. This pressure arises because flexible learners can best cope with the observed high rates of linguistic change associated with divergent cultural evolution following human migration. Thus, rather than genetic adaptations for specific aspects of language, such as recursion, the coevolution of genes and fast-changing linguistic structure provides the biological basis for linguistic diversity. Only biological adaptations for flexible learning combined with cultural evolution can explain how each child has the potential to learn any human language

Decreased glutathione biosynthesis contributes to EGFR T790M-driven erlotinib resistance in non-small cell lung cancer

Epidermal growth factor receptor (EGFR) inhibitors such as erlotinib are novel effective agents in the treatment of EGFR-driven lung cancer, but their clinical impact is often impaired by acquired drug resistance through the secondary T790M EGFR mutation. To overcome this problem, we analysed the metabonomic differences between two independent pairs of erlotinib-sensitive/resistant cells and discovered that glutathione (GSH) levels were significantly reduced in T790M EGFR cells. We also found that increasing GSH levels in erlotinib-resistant cells re-sensitised them, whereas reducing GSH levels in erlotinib-sensitive cells made them resistant. Decreased transcription of the GSH-synthesising enzymes (GCLC and GSS) due to the inhibition of NRF2 was responsible for low GSH levels in resistant cells that was directly linked to the T790M mutation. T790M EGFR clinical samples also showed decreased expression of these key enzymes; increasing intra-tumoural GSH levels with a small-molecule GST inhibitor re-sensitised resistant tumours to erlotinib in mice. Thus, we identified a new resistance pathway controlled by EGFR T790M and a therapeutic strategy to tackle this problem in the clinic

Sidechain control of porosity closure in multiple peptide-based porous materials by cooperative folding

Porous materials find application in separation, storage and catalysis. We report a crystalline porous solid formed by coordination of metal centres with a glycylserine dipeptide. We prove experimentally that the structure evolves from a solvated porous into a non-porous state as result of ordered displacive and conformational changes of the peptide that suppress the void space in response to environmental pressure. This cooperative closure, which recalls the folding of proteins, retains order in three-dimensions and is driven by the hydroxyl groups acting as H-bond donors in the peptide sequence through the serine residue. This ordered closure is also displayed by multipeptide solid solutions in which the combination of different sequences of amino acids controls their guest response in a non-linear way. This functional control can be compared to the effect of single point mutations in proteins, where the exchange of single amino acids can radically alter structure and functio