Martian meso/micro-scale winds and surface energy budget

Regional, diurnal and seasonal variations of surface temperature are particularly large on Mars. This is mostly due to the Martian surface remaining close to radiative equilibrium. Contrary to most terrestrial locations, contributions of sensible heat flux (i.e. conduction/convection exchanges between atmosphere and surface) to the surface energy budget [hereinafter SEB] are negligible on Mars owing to lowatmospheric density and heat capacity (e.g. Figure 2 in Savijärvi and Kauhanen, 2008). This radiative control of surface temperature is a key characteristic of the Martian environment and has crucial consequences on the the Martian geology, meteorology, exobiology, etc. In order to identify the impact of this Martian peculiarity to near-surface regional-to-local atmospheric circulations, we employ our recently-built Martian limited-area meteorological model (Spiga and Forget, 2009). We use horizontal resolutions adapted to the dynamical phenomena we aim to resolve: from several tens of kilometers to compute regional winds (mesoscale simulations) to several tens of meters to compute atmospheric boundary-layer winds (microscale or turbulent-resolving simulations, also called Large-Eddy Simulations, LES)

Mars Climate Database version 5

The Mars Climate Database (MCD) is a database of meteorological fields derived from General Circulation Model (GCM) numerical simulations [2,4] of the Martian atmosphere and validated using available observational data. The MCD includes complementary post-processing schemes such as high spatial resolution interpolation of environmental data and means of reconstructing the variability thereof. The GCM is developed at LMD (Laboratoire de Météorologie Dynamique, Paris, France) in collaboration with several teams in Europe: LATMOS (Laboratoire Atmosphères, Milieux, Observations Spatiales, Paris, France), the Open University (UK), the Oxford University (UK) and the Instituto de Astrofisica de Andalucia (Spain) with support from the European Space Agency (ESA) and the Centre National d'Etudes Spatiales (CNES). The MCD is freely distributed and intended to be useful and used in the framework of engineering applications as well as in the context of scientific studies which require accurate knowledge of the state of the Martian atmosphere. The Mars Climate Database (MCD) has over the years been distributed to more than 150 teams around the world. With the many improvements implemented in the GCM over the last few years, a new series of reference simulations have been run and compiled in a new version (version 5) of the Mars Climate Database, released in the first half of 2012

Task-related default mode network modulation and inhibitory control in ADHD: effects of motivation and methylphenidate

Background: Deficits characteristic of Attention Deficit/Hyperactivity Disorder (ADHD), including poor attention and inhibitory control, are at least partially alleviated by factors that increase engagement of attention, suggesting a hypodopaminergic reward deficit. Lapses of attention are associated with attenuated deactivation of the Default Mode Network (DMN), a distributed brain system normally deactivated during tasks requiring attention to the external world. Task-related DMN deactivation has been shown to be attenuated in ADHD relative to controls. We hypothesised that motivational incentives to balance speed against restraint would increase task engagement during an inhibitory control task, enhancing DMN deactivation in ADHD. We also hypothesised that methylphenidate, an indirect dopamine agonist, would tend to normalise abnormal patterns of DMN deactivation. Method: We obtained functional magnetic resonance images from eighteen methylphenidate-responsive children with ADHD (DSM-IV combined subtype) and 18 pairwise-matched typically developing children aged 9-15 years while they performed a paced Go/No-go task. We manipulated motivational incentive to balance response speed against inhibitory control, and tested children with ADHD both on and off methylphenidate. Results: When children with ADHD were off-methylphenidate and task incentive was low, event-related DMN deactivation was significantly attenuated compared to controls, but the two groups did not differ under high motivational incentives. The modulation of DMN deactivation by incentive in the children with ADHD, off- methylphenidate, was statistically significant, and significantly greater than in typically developing children. When children with ADHD were on-methylphenidate, motivational modulation of event-related DMN deactivation was abolished, and no attenuation relative to their typically developing peers was apparent in either motivational condition. Conclusions: During an inhibitory control task, children with ADHD exhibit a raised motivational threshold at which task-relevant stimuli become sufficiently salient to deactivate the DMN. Treatment with methylphenidate normalises this threshold, rendering their pattern of task-related DMN deactivation indistinguishable from that of typically developing children

Is Gliese 581d habitable? Some constraints from radiative-convective climate modeling

The recently discovered exoplanet Gl581d is extremely close to the outer edge of its system's habitable zone, which has led to much speculation on its possible climate. We have performed a range of simulations to assess whether, given simple combinations of chemically stable greenhouse gases, the planet could sustain liquid water on its surface. For best estimates of the surface gravity, surface albedo and cloud coverage, we find that less than 10 bars of CO2 is sufficient to maintain a global mean temperature above the melting point of water. Furthermore, even with the most conservative choices of these parameters, we calculate temperatures above the water melting point for CO2 partial pressures greater than about 40 bar. However, we note that as Gl581d is probably in a tidally resonant orbit, further simulations in 3D are required to test whether such atmospheric conditions are stable against the collapse of CO2 on the surface.Comment: 9 pages, 11 figures. Accepted for publication in Astronomy & Astrophysic

Diquat Derivatives: Highly Active, Two-Dimensional Nonlinear Optical Chromophores with Potential Redox Switchability

In this article, we present a detailed study of structure−activity relationships in diquaternized 2,2′-bipyridyl (diquat) derivatives. Sixteen new chromophores have been synthesized, with variations in the amino electron donor substituents, π-conjugated bridge, and alkyl diquaternizing unit. Our aim is to combine very large, two-dimensional (2D) quadratic nonlinear optical (NLO) responses with reversible redox chemistry. The chromophores have been characterized as their PF_6^− salts by using various techniques including electronic absorption spectroscopy and cyclic voltammetry. Their visible absorption spectra are dominated by intense π → π^* intramolecular charge-transfer (ICT) bands, and all show two reversible diquat-based reductions. First hyperpolarizabilities β have been measured by using hyper-Rayleigh scattering with an 800 nm laser, and Stark spectroscopy of the ICT bands affords estimated static first hyperpolarizabilities β_0. The directly and indirectly derived β values are large and increase with the extent of π-conjugation and electron donor strength. Extending the quaternizing alkyl linkage always increases the ICT energy and decreases the E_(1/2) values for diquat reduction, but a compensating increase in the ICT intensity prevents significant decreases in Stark-based β_0 responses. Nine single-crystal X-ray structures have also been obtained. Time-dependent density functional theory clarifies the molecular electronic/optical properties, and finite field calculations agree with polarized HRS data in that the NLO responses of the disubstituted species are dominated by ‘off-diagonal’ β_(zyy) components. The most significant findings of these studies are: (i) β_0 values as much as 6 times that of the chromophore in the technologically important material (E)-4′-(dimethylamino)-N-methyl-4-stilbazolium tosylate; (ii) reversible electrochemistry that offers potential for redox-switching of optical properties over multiple states; (iii) strongly 2D NLO responses that may be exploited for novel practical applications; (iv) a new polar material, suitable for bulk NLO behavior

Die Agitpropbewegung als Teil der Arbeiterkultur der Weimarer Republik

The advent of next-generation sequencing has brought about an explosion of single nucleotide polymorphism (SNP) data in non-model organisms; however, profiling these SNPs across multiple natural populations still requires substantial time and resources. Results: Here, we introduce two cost-efficient quantitative High Resolution Melting (qHRM) methods for measuring allele frequencies at known SNP loci in pooled DNA samples: the "peaks" method, which can be applied to large numbers of SNPs, and the "curves" method, which is more labor intensive but also slightly more accurate. Using the reef-building coral Acropora millepora, we show that both qHRM methods can recover the allele proportions from mixtures prepared using two or more individuals of known genotype. We further demonstrate advantages of each method over previously published methods; specifically, the "peaks" method can be rapidly scaled to screen several hundred SNPs at once, whereas the "curves" method is better suited for smaller numbers of SNPs. Conclusions: Compared to genotyping individual samples, these methods can save considerable effort and genotyping costs when relatively few candidate SNPs must be profiled across a large number of populations. One of the main applications of this method could be validation of SNPs of interest identified in population genomic studies.Australian Institute of Marine ScienceNational Science Foundation DEB-1054766Cellular and Molecular Biolog

Modeling the martian atmosphere with the LMD global climate model

Introduction: For several years we have been developing a 3D Global Climate Model (GCM) for Mars derived from the models used on Earth for weather forecasting or climate changes studies [1]. The purpose of such a project is ambitious: we wish to build a 'Mars simulator' based only on physical equations, with no tailor-made forcing, but able to reproduce all the available observations of the Martian climate (temperatures, winds, but also clouds, dust, ices, chemical species, etc...). The GCM is constantly evolving, thanks to a contnuous collaboration between several teams based in France (LMD, SA), the UK (The Open University, University of Oxford) and Spain (Instituto de Astrofisica de Andalucia), and with the support of ESA and CNES. We are currently working on an improved version of the model. Several new parametrisation are included in the heart of the model (radiative transfer, surface and subsurface processes, dynamics) and the applications of the GCM are in contnuous development (Water, dust, CO2, radon cycles, photochemistry, thermosphere, ionosphere, etc...

Improving access to and engagement with mental health services among young people from refugee backgrounds: service user and provider perspectives

Limited research has been conducted worldwide on the experiences that children and young people from refugee backgrounds have with mental health services, despite evidence that they have significant vulnerability to the development of mental health problems and to suicidal behaviour and that those with mental ill-health typically underutilise services. The authors were particularly interested in barriers and facilitators to service access and engagement, and conducted two qualitative research projects to improve understanding of the issues – the first with service providers experienced in the refugee area and the second with young refugee service users. The aim of this project was to compare the perspectives of professionals and service users and to identify similarities and differences. The perspectives of the service users and providers were strikingly similar. The analysis identified 21 implications for policy makers, agencies and practitioners, which ranged from issues concerning cultural sensitivity, background matching and mental health literacy to accessibility, setting boundaries and expectations and implementing a holistic and outreach approach. There is a range of specific, practical measures that policy makers and service providers can introduce to enhance access to and engagement with mental health services for young people from refugee backgrounds

Створення та діяльність УПА в період Другої світової війни в світлі північноамериканської історіографії

У статті здійснено комплексний аналіз північноамериканської історіографії діяльності УПА. Виходячи з методологічних підходів, дослідницьких технік та світоглядних позицій було виокремлено три групи північноамериканських дослідників: емігрантську, діаспорну та американську. Автор зосереджується на детальному аналізі часу створення і чисельності УПА та Волинській трагедії.The article is dedicated to the complex analysis of the North-American historiography of the UPA activity. According to methodological approaches, investigation technique, and world outlook of the authors, the three groups of North-American researchers were singled out: the emigrant, the diaspora and the American one. The author analyzes in detailed the time of creation and number of the UPA troops as well as the Volynian tragedy

In situ detection of boron by ChemCam on Mars

We report the first in situ detection of boron on Mars. Boron has been detected in Gale crater at levels Curiosity rover ChemCam instrument in calcium-sulfate-filled fractures, which formed in a late-stage groundwater circulating mainly in phyllosilicate-rich bedrock interpreted as lacustrine in origin. We consider two main groundwater-driven hypotheses to explain the presence of boron in the veins: leaching of borates out of bedrock or the redistribution of borate by dissolution of borate-bearing evaporite deposits. Our results suggest that an evaporation mechanism is most likely, implying that Gale groundwaters were mildly alkaline. On Earth, boron may be a necessary component for the origin of life; on Mars, its presence suggests that subsurface groundwater conditions could have supported prebiotic chemical reactions if organics were also present and provides additional support for the past habitability of Gale crater