Analyse de données de l'expérience VIRGO

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Cross-language Wikipedia Editing of Okinawa, Japan

This article analyzes users who edit Wikipedia articles about Okinawa, Japan, in English and Japanese. It finds these users are among the most active and dedicated users in their primary languages, where they make many large, high-quality edits. However, when these users edit in their non-primary languages, they tend to make edits of a different type that are overall smaller in size and more often restricted to the narrow set of articles that exist in both languages. Design changes to motivate wider contributions from users in their non-primary languages and to encourage multilingual users to transfer more information across language divides are presented.Comment: In Proceedings of the SIGCHI Conference on Human Factors in Computing Systems, CHI 2015. AC

Scanning Hyperspectral Imaging for In Situ Biogeochemical Analysis of Lake Sediment Cores: Review of Recent Developments

Hyperspectral imaging (HSI) in situ core scanning has emerged as a valuable and novel tool for rapid and non-destructive biogeochemical analysis of lake sediment cores. Variations in sediment composition can be assessed directly from fresh sediment surfaces at ultra-high-resolution (40–300 μm measurement resolution) based on spectral profiles of light reflected from sediments in visible, near infrared, and short-wave infrared wavelengths (400–2500 nm). Here, we review recent methodological developments in this new and growing field of research, as well as applications of this technique for paleoclimate and paleoenvironmental studies. Hyperspectral imaging of sediment cores has been demonstrated to effectively track variations in sedimentary pigments, organic matter, grain size, minerogenic components, and other sedimentary features. These biogeochemical variables record information about past climatic conditions, paleoproductivity, past hypolimnetic anoxia, aeolian input, volcanic eruptions, earthquake and flood frequencies, and other variables of environmental relevance. HSI has been applied to study seasonal and inter-annual environmental variability as recorded in individual varves (annually laminated sediments) or to study sedimentary records covering long glacial–interglacial time-scales (>10,000 years)

Linking the formation of varves in a eutrophic temperate lake to meteorological conditions and water column dynamics.

Despite varved sediments being widely used for paleolimnological studies, little information is available about how climate and meteorological signals are recorded in varves at sub-seasonal to annual scale. We investigate links between meteorological and limnological conditions and their influence on biochemical varve formation and preservation of sub-seasonal climate signals in the sediments. Our study site is postglacial Lake Żabińskie located in NE Poland, in which thick and complex varved sediments have been studied for the last decade. These sediments provide an excellent material for studying the influence of short-term weather conditions on geological records. For this, we use an almost decade-long (2012-2019) series of observational data (meteorological conditions, physicochemical water parameters, and modern sedimentation observations) to understand varve formation processes. Then we compare these results with a high-resolution biogeochemical proxy dataset based on μXRF and hyperspectral imaging (HSI) measurements of a varved sediment core spanning the same period. Here we show direct links between the meteorological and limnological conditions and varve formation processes This is particularly the case for air temperature which governs calcite laminae formation and primary production. We further show that calcite grain size is influenced by lake mixing intensity resulting from the wind activity, and that holomixis events lead to the formation of distinct manganese (Mn) peaks in the typically anoxic sediments. Our findings show that high-resolution non-destructive spectroscopy methods applied to complex biochemical varves, in combination with long observational limnological datasets, provide useful information for tracking meteorological and limnological processes in the past

Scanning reflectance spectroscopy (380-730nm): a novel method for quantitative high-resolution climate reconstructions from minerogenic lake sediments

High-resolution (annual to sub-decadal) quantitative reconstructions of climate variables are needed from a variety of paleoclimate archives across the world to place current climate change in the context of long-term natural climate variability. Rapid, high-resolution, non-destructive scanning techniques are required to produce such high-resolution records from lake sediments. In this study we explored the potential of scanning reflectance spectroscopy (VIS-RS; 380-730nm) to produce quantitative summer temperature reconstructions from minerogenic sediments of proglacial, annually laminated Lake Silvaplana, in the eastern Swiss Alps. The scanning resolution was 2mm, which corresponded to sediment deposition over 1-2years. We found correlations up to r=0.84 (p<0.05) for the calibration period 1864-1950, between six reflectance-dependent variables and summer (JJAS) temperature. These reflectance-dependent variables (e.g. slope of the reflectance 570/630nm, indicative of illite, biotite and chlorite; minimum reflectance at 690nm indicative of chlorite) indicate the mineralogical composition of the clastic sediments, which is, in turn, related to climate in the catchment of this particular proglacial lake. We used multiple linear regression (MLR) to establish a calibration model that explains 84% of the variance of summer (JJAS) temperature during the calibration period 1864-1950. We then applied the calibration model downcore to develop a quantitative summer temperature reconstruction extending back to AD 1177. This temperature reconstruction is in good agreement with two independent temperature reconstructions based on documentary data that extend back to AD 1500 and tree ring data that extend back to AD 1177. This study confirms the great potential of in situ scanning reflectance spectroscopy as a novel non-destructive technique to rapidly acquire high-resolution quantitative paleoclimate information from minerogenic lake sediment

Land-based, closed-cycle echiniculture of <i>Paracentrotus lividus</i> (Lamarck) (Echinoldea: Echinodermata): a long-term experiment at a pilot scale

Today, most sea urchins fisheries worldwide must deal with overexploitation. Better management of exploited field populations and/or aquaculture is increasingly considered necessary to sustain sea urchin production in the future. In this context, we evaluate the potential of land-based, closed-cycle echiniculture. A long-term experiment with the edible sea urchin Paracentrotus lividus has been done on a pilot scale. The process allows total independence from natural resources, because the entire biological cycle of the echinoids is under control (closed-cycle echiniculture), and all activities are performed on land. Furthermore, a method has been set up to control the reproductive cycle with the aim to produce marketable individuals all year long. Performances obtained on each stage of the rearing process are quantified and analyzed. Overall, the results of this experiment are promising; however, some problems remain to be solved before we can claim profitability. The most important finding is that land-based, closed-cycle echiniculture is a potential viable supplement to fisheries to sustain worldwide sea urchin roe production

Can vouchers reduce elite capture of local development projects? Experimental evidence from the Solomon Islands

External financing of local public goods can potentially create 'political resource curses' by reducing citizen oversight, exacerbating elite capture, and producing policy outcomes that are sub-optimal for the general population. This paper experimentally tests a novel mechanism that seeks to mitigate elite capture of local development projects. Control communities are provided with block grants to fund local public goods, while households in treatment communities are provided with vouchers that they may either contribute to a public good or redeem at a discount for a private capital good. We find that the use of vouchers as a mechanism for aid delivery increases community participation in local public decision-making, changes the nature of allocation outcomes, and improves community satisfaction with allocation outcomes

Consecutive episodes of heart and kidney failure in an "otherwise" healthy young man

Background: Acute renal failure is a rare occurrence in a patient with an unremarkable past medical history and should always lead to an in depth clinical study. The occurrence in the same healthy young subject, of consecutive episodes of heart failure and of acute renal failure is an even rarer event and should prompt diagnostic tests and restrict the diagnostic hypotheses. Case presentation: We present the case of a 28 year-old man who, while waiting to undergo assessment for a mild chronic kidney disease, was diagnosed with decompensated dilated cardiomyopathy and placed on diuretics and β-blockers. After few weeks he developed a non oligoanuric acute renal failure with a slight elevation of serum calcium. Renal biopsy proved suggestive for renal sarcoidosis; thus the hypothesis of systemic sarcoidosis with cardiac and renal involvement was possible avoiding further delay in initiation of therapy. Conclusions: Cardiac sarcoidosis is usually silent but the majority of cases are diagnosed when cardiac symptoms are present in a patient with systemic sarcoidosis. Renal involvement with granulomatous interstitial nephritis is also quite rare and can be an unexpected finding at kidney biopsy. This case highlights the need to evaluate thoroughly clinical problems that do not fit in a specific scenario and emphasizes the importance of performing a kidney biopsy in case of kidney failure of unknown etiology

PHARAO Laser Source Flight Model: Design and Performances

In this paper, we describe the design and the main performances of the PHARAO laser source flight model. PHARAO is a laser cooled cesium clock specially designed for operation in space and the laser source is one of the main sub-systems. The flight model presented in this work is the first remote-controlled laser system designed for spaceborne cold atom manipulation. The main challenges arise from mechanical compatibility with space constraints, which impose a high level of compactness, a low electric power consumption, a wide range of operating temperature and a vacuum environment. We describe the main functions of the laser source and give an overview of the main technologies developed for this instrument. We present some results of the qualification process. The characteristics of the laser source flight model, and their impact on the clock performances, have been verified in operational conditions.Comment: Accepted for publication in Review of Scientific Instrument

A rapid microwave-assisted procedure for easy access to Nx polydentate ligands for potential application in α-RIT

International audienceHeterocycles bearing a hydrazine moiety react with bisaldehydes or bisketones to afford new Nx polydentate ligands suitable for α-radioimmunotherapy. We developed a fast and efficient method using microwave-assisted technology to obtain chelators with variable size and number of coordination centres which were fully characterized. The complexation efficiency with astatine will be assessed