Structure and orientation of small particles of platinum deposited on NaCl and mica

The structure of small platinum particles condensed in vacuum onto NaCl (001), NaCl (111) and mica substrates was studied by electron diffraction and electron microscopy. Results show that above a certain substrate temperature decahedral or icosahedral particles are formed. These particles are practically absent with substrates cleaved in high vacuum. They are always much less numerous than in gold films prepared under the same conditions. Assumptions made to explain this phenomenon are: (1) the initial growth of an abnormal structure of the nuclei as opposed by the substrate; (2) the particles disappear before they attain a size which corresponds to the observations; and (3) the particles result from a coalescence mechanism leading to multiple twinned particles

Rule Extraction from Support Vector Machines: A Geometric Approach. Technical Report

This paper presents a new approach to rule extraction from Support Vector Machines. SVMs have been applied successfully in many areas with excellent generalization results; rule extraction can offer explanation capability to SVMs. We propose to approximate the SVM classification boundary through querying followed by clustering, searching and then to extract rules by solving an optimization problem. Theoretical proof and experimental results then indicate that the rules can be used to validate the SVM results, since maximum fidelity with high accuracy can be achieved

Electrodeposition of In2S3 buffer layer for Cu(In,Ga)Se2 solar cells

AbstractThe electrochemical deposition of In2S3 thin films was carried out from an aqueous solution of InCl3 and Na2S2O3. The effect of the potential of deposition was studied on the cell parameters of CIGSe based solar cells. The obtained films depending on the deposition potential and thickness exhibited complete substrate coverage or nanocolumnar layers. XPS measurements detected the presence of indium sulphide and hydroxide depending on the deposition parameters. Maximum photoelectric conversion efficiency of 10.2% was obtained, limited mainly by a low fill factor (56%). Further process optimization is expected to lead to efficiencies comparable to CdS buffer layers

The MIK2/SCOOP Signaling System Contributes to Arabidopsis Resistance Against Herbivory by Modulating Jasmonate and Indole Glucosinolate Biosynthesis.

Initiation of plant immune signaling requires recognition of conserved molecular patterns from microbes and herbivores by plasma membrane-localized pattern recognition receptors. Additionally, plants produce and secrete numerous small peptide hormones, termed phytocytokines, which act as secondary danger signals to modulate immunity. In Arabidopsis, the Brassicae-specific SERINE RICH ENDOGENOUS PEPTIDE (SCOOP) family consists of 14 members that are perceived by the leucine-rich repeat receptor kinase MALE DISCOVERER 1-INTERACTING RECEPTOR LIKE KINASE 2 (MIK2). Recognition of SCOOP peptides elicits generic early signaling responses but knowledge on how and if SCOOPs modulate specific downstream immune defenses is limited. We report here that depletion of MIK2 or the single PROSCOOP12 precursor results in decreased Arabidopsis resistance against the generalist herbivore Spodoptera littoralis but not the specialist Pieris brassicae. Increased performance of S. littoralis on mik2-1 and proscoop12 is accompanied by a diminished accumulation of jasmonic acid, jasmonate-isoleucine and indolic glucosinolates. Additionally, we show transcriptional activation of the PROSCOOP gene family in response to insect herbivory. Our data therefore indicate that perception of endogenous SCOOP peptides by MIK2 modulates the jasmonate pathway and thereby contributes to enhanced defense against a generalist herbivore

DIVERSITY OF THE SOUTHERN GREEN STINK BUG NEZARA VIRIDULA (L.) (HETEROPTERA: PENTATOMIDAE)

The southern green stink bug Nezara viridula (L.) (Heteroptera: Pentatomidae) is a global pest of considerable ecological, agricultural and economical interest. The ancestral home of this species is supposed to be Africa and/or Mediterranean and presumably it was spread worldwide during the last two centuries with human trade and agriculture. Bugs found today on different continents do not differ morphologically, however there are substantial differences in their mating behaviour. We used horizontal starch gel electrophoresis to determine the suitability of biochemical markers for assessment of genetic variation between geographically isolated populations of N. viridula. The initial survey of populations from Slovenia, France, French West Indies and Brazil resulted in the resolution of polymorphic banding patterns within the following enzyme systems: GPI, IDH, MDH, ME, MPI and PGM. Results indicate there are consistent differences among tested populations

Mouthiers-sur-Boëme, Chez les Rois

Chez les Rois est un gisement de référence de l'Aurignacien charentais et un des rares gisements aurignaciens européens à avoir livré des restes humains en place. Fouillé entre 1930 et 1939 par Potut et entre 1948 et 1952 par Mouton et Joffroy (1958), ce gisement a fait l'objet d'un sondage en 2005 et d'une fouille programmée entre 2006 et 2008 (d'Errico et Vanhaeren 2005, 2006, 2007, 2008). Cette opération de terrain a fait suite à la reprise de l'étude des restes humains et du matériel archéologique issus des fouilles Mouton et Joffroy ainsi qu'à sa datation (Ramirez Rozzi et al. sous presse). L'objectif des nouvelles fouilles était de préciser l'attribution culturelle des assemblages, la chronologie et nature de l'occupation aurignacienne ainsi que l'affiliation taxinomique des groupes humains qui ont fréquenté le site

Arabidopsis Roots and Shoots Show Distinct Temporal Adaptation Patterns toward Nitrogen Starvation

Nitrogen (N) is an essential macronutrient for plants. N levels in soil vary widely, and plants have developed strategies to cope with N deficiency. However, the regulation of these adaptive responses and the coordinating signals that underlie them are still poorly understood. The aim of this study was to characterize N starvation in adult Arabidopsis (Arabidopsis thaliana) plants in a spatiotemporal manner by an integrative, multilevel global approach analyzing growth, metabolites, enzyme activities, and transcript levels. We determined that the remobilization of N and carbon compounds to the growing roots occurred long before the internal N stores became depleted. A global metabolite analysis by gas chromatography-mass spectrometry revealed organ-specific differences in the metabolic adaptation to complete N starvation, for example, for several tricarboxylic acid cycle intermediates, but also for carbohydrates, secondary products, and phosphate. The activities of central N metabolism enzymes and the capacity for nitrate uptake adapted to N starvation by favoring N remobilization and by increasing the high-affinity nitrate uptake capacity after long-term starvation. Changes in the transcriptome confirmed earlier studies and added a new dimension by revealing specific spatiotemporal patterns and several unknown N starvation-regulated genes, including new predicted small RNA genes. No global correlation between metabolites, enzyme activities, and transcripts was evident. However, this multilevel spatiotemporal global study revealed numerous new patterns of adaptation mechanisms to N starvation. In the context of a sustainable agriculture, this work will give new insight for the production of crops with increased N use efficiency

The effect of carnitine on Arabidopsis development and recovery in salt stress conditions

Carnitine exists in all living organisms where it plays diverse roles. In animals and yeast, it is implicated in lipid metabolism and is also associated with oxidative stress tolerance. In bacteria, it is a major player in osmotic stress tolerance. We investigate the carnitine function in plants and our present work shows that carnitine enhances the development and recovery of Arabidopsis thaliana seedlings subjected to salt stress. Biological data show that exogenous carnitine supplies improve the germination and survival rates of seedlings grown on salt-enriched medium, in a manner comparable to proline. Both compounds are shown to improve seedling survival under oxidative constraint meaning that they may act on salt stress through antioxidant properties. A transcriptome analysis of seedlings treated with exogenous carnitine reveals that it modulates the expression of genes involved in water stress and abscisic acid responses. Analyses of the abscisic acid mutants, aba1-1 and abi1-1, indicate that carnitine and proline may act through a modulation of the ABA pathway

Greenhouse gas emission factors associated with rewetting of organic soils

Drained organic soils are a significant source of greenhouse gas (GHG) emissions to the atmosphere. Rewetting these soils may reduce GHG emissions and could also create suitable conditions for return of the carbon (C) sink function characteristic of undrained organic soils. In this article we expand on the work relating to rewetted organic soils that was carried out for the 2014 Intergovernmental Panel on Climate Change (IPCC) Wetlands Supplement. We describe the methods and scientific approach used to derive the Tier 1 emission factors (the rate of emission per unit of activity) for the full suite of GHG and waterborne C fluxes associated with rewetting of organic soils. We recorded a total of 352 GHG and waterborne annual flux data points from an extensive literature search and these were disaggregated by flux type (i.e. CO2, CH4, N2O and DOC), climate zone and nutrient status. Our results showed fundamental differences between the GHG dynamics of drained and rewetted organic soils and, based on the 100 year global warming potential of each gas, indicated that rewetting of drained organic soils leads to: net annual removals of CO2 in the majority of organic soil classes; an increase in annual CH4 emissions; a decrease in N2O and DOC losses; and a lowering of net GHG emissions. Data published since the Wetlands Supplement (n = 58) generally support our derivations. Significant data gaps exist, particularly with regard to tropical organic soils, DOC and N2O. We propose that the uncertainty associated with our derivations could be significantly reduced by the development of country specific emission factors that could in turn be disaggregated by factors such as vegetation composition, water table level, time since rewetting and previous land use history