Evidence for K-rich terranes on Vesta from impact spherules

International audienceThe howardite-eucrite-diogenite (HED) clan is a group of meteorites that probably originate from the asteroid Vesta. Some of them are complex breccias that contain impact glasses whose compositions mirror that of their source regions. Some K-rich impact glasses (up to 2 wt% K2O) suggest that in addition to basalts and ultramafic cumulates, K-rich rocks are exposed on Vesta's surface. One K-rich glass (up to 6 wt% K2O), with a felsic composition, provides the first evidence of highly differentiated K-rich rocks on a large asteroid. They can be compared to the rare lunar granites and suggest that magmas generated in a large asteroid are more diverse than previously thought

A practical approach to estimate resting energy expenditure in frail elderly people

Objectives: Some prediction equations of resting energy expenditure (REE) are available and can be used in clinical wards to determine energy requirements of patients. The aim of the present study was to assess the accuracy of those equations in sick elderly patients, using the Bland & Altman methods with our database of 187 REE measurements.Design: The 3 equations tested were Harris & Benedict equation of 1919, WHO/FAO/UNU equation of 1985 and Fredrix et al. equation of 1990. In addition, three models developed from the present data were tested.Results: The present study shows that the Fredrix et al equation gave an accurate prediction of REE without significant bias along the whole range of REE. It also shows that under-weight sick elderly patients (BMI ≤ 21 kg/m2) had a greater weight-adjusted REE than their normal weight counterparts.Conclusion: A simple formula using a factor multiplying body weight, i.e. 22 kcal/kg/d in under-weight and 19 kcal/kg/d in normal weight sick elderly was accurate to predicting REE and bias was not influenced by the level of REE. This model included half of the group in the range of ±10% of the difference between predicted REE and measured REE, but the confidence interval of the bias was ±400 kcal/d. Conversely, the Harris & Benedict and WHO formulae did accurately predict REE

A Thousand Years of Lost Hunting Arrows: Wood Analysis of Ice Patch Remains in Northwestern Canada

Discussions of the development of past hunting equipment generally focus on lithic and bone projectile points and foreshafts, as these are often the only elements remaining in archaeological sites. In the last 15 years, the archaeology of alpine ice patches has provided a unique opportunity to analyze hunting equipment over time and gain knowledge of the wooden elements on which the points are hafted. This paper describes the wood and morphometrical analysis of a collection of 27 arrow shafts from two ice patch regions of the western Canadian Subarctic. In both regions, two main categories of arrow shafts show the selection of specific pieces of wood, spruce (Picea sp.) on the one hand and birch (Betula sp.) on the other, with associated morphometrical characteristics. These shafts also share some characteristics that are distinct from those of Arctic and coastal arrow shafts. Shafts of pine (Pinus sp. sec. ponderosa) and hemlock (Tsuga sp.) were also identified in the southwestern Yukon Territory. The absence of correlation between the arrow shaft types and 14C dating raises the question of the significance of the arrow types and the potential for function, trade, or travel to explain the variation.Les discussions sur le développement des armes de chasse se concentrent généralement sur les pointes de projectile et les préhampes en matières lithiques et osseuses car ce sont ces éléments qui sont les plus souvent retrouvés dans les sites archéologiques. Ces quinze dernières années, l’archéologie des névés alpins nous donne l’opportunité unique d’analyser des équipements de chasse sur le long terme et de documenter les éléments en bois au bout desquels les pointes sont emmanchées. Dans cet article, nous décrivons l’analyse d’une collection de vingt-sept hampes de flèche en bois végétal provenant de deux régions de névés du Subarctique canadien. Dans les deux régions, on définit deux catégories principales de hampes de flèche qui montrent une sélection spécifique de pièces de bois d’épicéa (Picea sp.) et de bouleau (Betula sp.) auxquelles correspondent des caractéristiques morphométriques propres. Ces hampes partagent aussi des caractéristiques qui les distinguent de celles plus nordiques des côtes de l’Arctique. Des hampes faites en bois de pin (Pinus sp. sec. ponderosa) et de pruche (Tsuga sp.) ont également été identifiées dans le Sud-ouest du Territoire du Yukon. L’absence de corrélation entre les types de hampe de flèche et les dates radiocarbone soulève la question du sens à donner à ces types de flèche. Des facteurs tels que la fonction, les échanges ou des déplacements de personne sont envisagés

Holocene geochemical footprint from Semiarid alpine wetlands in southern Spain

Here we provide the geochemical dataset that our research group has collected after 10 years of investigation in the Sierra Nevada National Park in southern Spain. These data come from Holocene sedimentary records from four alpine sites (ranging from ∼2500 to ∼3000 masl): two peatlands and two shallow lakes. Different kinds of organic and inorganic analyses have been conducted. The organic matter in the bulk sediment was characterised using elemental measurements and isotope-ratio mass spectrometry (EA-IRMS). Leaf waxes in the sediment were investigated by means of chromatography with flame-ionization detection and mass spectrometry (GC-FID, GC-MS). Major, minor and trace elements of the sediments were analysed with atomic absorption (AAS), inductively coupled plasma mass spectrometry (ICP-MS), as well as X-ray scanning fluorescence. These data can be reused by environmental researchers and soil and land managers of the Sierra Nevada National Park and similar regions to identify the effect of natural climate change, overprinted by human impact, as well as to project new management policies in similar protected areas.Universidad de Granada. Departamento de Estratigrafía y PaleontologíaJunta de Andalucía: Grupos de investigación RNM190 y RNM309Junta de Andalucía: Proyecto P11-RNM-7332España, Ministerio de Economía y Competitividad: Proyecto CGL2013-47038-RRamón y Cajal Fellowship: RYC-2015-18966Small Research Grant by the Carnegie Trust for the Universities of ScotlandMarie Curie Intra-European Fellowship of the 7th Framework Programme for Research, Technological Development and Demonstration of the European Commission: NAOSIPUK. Grant Number: PIEF-GA-2012-62302

Rigorous Multicomponent Reactive Separations Modelling : Complete Consideration of Reaction-Diffusion Phenomena

This paper gives the first step of the development of a rigorous multicomponent reactive separation model. Such a model is highly essential to further the optimization of acid gases removal plants (CO2 capture, gas treating, etc.) in terms of size and energy consumption, since chemical solvents are conventionally used.Firstly, two main modelling approaches are presented: the equilibrium-based and the rate-based approaches. Secondly, an extended rate-based model with rigorous modelling methodology for diffusion-reaction phenomena is proposed. The film theory and the generalized Maxwell-Stefan equations are used in order to characterize multicomponent interactions. The complete chain of chemical reactions is taken into account. The reactions can be kinetically controlled or at chemical equilibrium, and they are considered for both liquid film and liquid bulk. Thirdly, the method of numerical resolution is described. Coupling the generalized Maxwell-Stefan equations with chemical equilibrium equations leads to a highly non-linear Differential-Algebraic Equations system known as DAE index 3. The set of equations is discretized with finite-differences as its integration by Gear method is complex. The resulting algebraic system is resolved by the Newton- Raphson method. Finally, the present model and the associated methods of numerical resolution are validated for the example of esterification of methanol. This archetype non-electrolytic system permits an interesting analysis of reaction impact on mass transfer, especially near the phase interface. The numerical resolution of the model by Newton-Raphson method gives good results in terms of calculation time and convergence. The simulations show that the impact of reactions at chemical equilibrium and that of kinetically controlled reactions with high kinetics on mass transfer is relatively similar. Moreover, the Fick’s law is less adapted for multicomponent mixtures where some abnormalities such as counter-diffusion take place

Novel brain expressed RNA identified at the MIR137 schizophrenia-associated locus

AbstractGenome-wide association studies (GWAS) have identified a locus on chromosome 1p21.3 to be highly associated with schizophrenia. A microRNA, MIR137, within this locus has been proposed as the gene causally associated with schizophrenia, due to its known role as a regulator of neuronal development and function. However, the involvement of other genes within this region, including DPYD (dihydropyrimidine dehydrogenase), is also plausible. In this communication, we describe a previously uncharacterised, brain-expressed RNA, EU358092, within the schizophrenia-associated region at 1p21.3. As we observed for MIR137, EU358092 expression was modulated in response to psychoactive drug treatment in the human SH-SY5Y neuroblastoma cell line. Bioinformatic analysis of publically available CNS expression data indicates that MIR137 and EU358092 are often co-expressed in vivo. A potential regulatory domain for expression of EU358092 is identified by bioinformatic analysis and its regulatory function is confirmed by reporter gene assays. These data suggest a potentially important role for EU358092 in the aetiology of schizophrenia, either individually or in combination with other genes at this locus