Image Slicer Performances from a Demonstrator for the SNAP/JDEM Mission - Part I: Wavelength Accuracy

A well-adapted visible and infrared spectrograph has been developed for the SNAP (SuperNova/Acceleration Probe) experiment proposed for JDEM. The instrument should have a high sensitivity to see faint supernovae but also a good redshift determination better than 0.003(1+z) and a precise spectrophotometry (2%). An instrument based on an integral field method with the powerful concept of imager slicing has been designed. A large prototyping effort has been performed in France which validates the concept. In particular a demonstrator reproducing the full optical configuration has been built and tested to prove the optical performances both in the visible and in the near infrared range. This paper is the first of two papers. The present paper focus on the wavelength measurement while the second one will present the spectrophotometric performances. We adress here the spectral accuracy expected both in the visible and in the near infrared range in such configuration and we demonstrate, in particular, that the image slicer enhances the instrumental performances in the spectral measurement precision by removing the slit effect. This work is supported in France by CNRS/INSU/IN2P3 and by the French spatial agency (CNES) and in US by the University of California.Comment: Submitted to PAS

What are the Visual Features Underlying Rapid Object Recognition?

Research progress in machine vision has been very significant in recent years. Robust face detection and identification algorithms are already readily available to consumers, and modern computer vision algorithms for generic object recognition are now coping with the richness and complexity of natural visual scenes. Unlike early vision models of object recognition that emphasized the role of figure-ground segmentation and spatial information between parts, recent successful approaches are based on the computation of loose collections of image features without prior segmentation or any explicit encoding of spatial relations. While these models remain simplistic models of visual processing, they suggest that, in principle, bottom-up activation of a loose collection of image features could support the rapid recognition of natural object categories and provide an initial coarse visual representation before more complex visual routines and attentional mechanisms take place. Focusing on biologically plausible computational models of (bottom-up) pre-attentive visual recognition, we review some of the key visual features that have been described in the literature. We discuss the consistency of these feature-based representations with classical theories from visual psychology and test their ability to account for human performance on a rapid object categorization task

Integration and Usage of an Industrial Network Management System in an Accelerator Controls Environment

In the last years the CERN accelerator networks infrastructure has been upgraded to contemporary industrial standards. A commercially available network management tool has been selected to monitor and optimise the usage of the infrastructure. HPOpenview Network Node Manager (NNM) provides concise and indepth views of network and devices connected with their operational status. It provides instant failure detection, can supply alarm information and gathers statistics to allow proactive maintenance thus reducing network congestion and downtime. The heterogeneous community of equipment as installed around CERN's PS, SPS and LEP accelerator complex can be monitored in a uniform manner from a single entry point. The integration of a network specialist tool into the accelerator operations environment required additional developments in information reduction and presentation to create intuitive graphical displays related to the accelerators geographical and functional situation. This report describes the integration of the most recent version of the HPOpenview NNM in the CERN Accelerator's Controls System and details the accelerator controls specific developments

European Economies in the First Epoch of Imperialism and Mercantilism. 1415-1846.

The costs and benefits of European Imperialism from the conquest of Ceuta, 1415, to the Treaty of Lusaka, 1974.Twelfth International Economic History Congress. Madrid, 1998.Patrick K. O'Brien and Leandro Prados de la Escosura (eds.)Editada en la Fundación Empresa PúblicaJorge M. Pedreira. «To Have and To Have not». The Economic Consequences of Empire: Portugal (1415-1822).-- Bartolomé Yun-Casalilla. The American Empire and the Spanish Economy: An Institutional and Regional Perspective.-- Pieter C. Emmer. The Economic Impact of the Dutch Expansion Overseas, 1570-1870.-- Paul Butel and François Crouzet. Empire and Economic Growth: the Case of 18th Century France.-- Stanley L. Engerman. British Imperialism in a Mercantilist Age, 1492-1849: Conceptual Issues and Empirical Problems.Publicad

Methodology to rapidly map and quantify whole-brain microvasculature in 3d

The role of microvasculature in the development of cerebral disorders remains ambiguous despite recent implications in ~45% of dementia cases (including Alzheimer’s) and ~20% of strokes.1 Our goal is to develop 3D, high resolution, whole-brain maps of the cerebral microvasculature. This will address the knowledge gap surrounding vasculature changes during disease progression and ultimately support the development of innovative treatment paradigms. This effort is complementary to the BRAIN Initiative’s emphasis on comprehensive neuronal mapping. To better understand the role of vasculature in the onset of cerebral pathologies, we have developed a protocol for capture, conversion and comparison of vascular structure and key characteristics in the intact mouse brain with quotidian programs. We created a novel pipeline for 3D whole-brain modeling using techniques of perfusion for vascular labeling, amendment of the iDISCO+ organ clearing protocol, light sheet microscopy (LSM), data handling and image processing. Our protocol relies on vascular labeling via retro-orbital perfusion of fluorescent Lectin-Dylight 649 (Vector Labs), which we have observed to label vasculature in a more comprehensive fashion than other dyes (i.e., lectin-FITC, DiI). It takes up to two days to achieve whole-brain clearing; whereas the iDISCO+ protocol requires the use of secondary antibodies and a timeline of weeks. In lieu of expensive software packages, such as the Filament Tracer feature in Imaris, we trace the vasculature using freeware packages that can be used for 3D reconstruction and manipulation from most personal computers (Figure 1B). Current work involves integration of our data with the Allen Brain Atlas, to merge our vascular computational data sets to an averaged frame of reference map for use by other groups. We anticipate that this approach can be used to study the relationship between microvascular structure and function with cerebral pathology and to fit mathematical models of hypoxia predictive of ischemic conditions in the brain. Please click Additional Files below to see the full abstract

Taste Quality Decoding Parallels Taste Sensations

SummaryIn most species, the sense of taste is key in the distinction of potentially nutritious and harmful food constituents and thereby in the acceptance (or rejection) of food. Taste quality is encoded by specialized receptors on the tongue, which detect chemicals corresponding to each of the basic tastes (sweet, salty, sour, bitter, and savory [1]), before taste quality information is transmitted via segregated neuronal fibers [2], distributed coding across neuronal fibers [3], or dynamic firing patterns [4] to the gustatory cortex in the insula. In rodents, both hardwired coding by labeled lines [2] and flexible, learning-dependent representations [5] and broadly tuned neurons [6] seem to coexist. It is currently unknown how, when, and where taste quality representations are established in the cortex and whether these representations are used for perceptual decisions. Here, we show that neuronal response patterns allow to decode which of four tastants (salty, sweet, sour, and bitter) participants tasted in a given trial by using time-resolved multivariate pattern analyses of large-scale electrophysiological brain responses. The onset of this prediction coincided with the earliest taste-evoked responses originating from the insula and opercular cortices, indicating that quality is among the first attributes of a taste represented in the central gustatory system. These response patterns correlated with perceptual decisions of taste quality: tastes that participants discriminated less accurately also evoked less discriminated brain response patterns. The results therefore provide the first evidence for a link between taste-related decision-making and the predictive value of these brain response patterns

ASTEP South: An Antarctic Search for Transiting ExoPlanets around the celestial South pole

ASTEP South is the first phase of the ASTEP project (Antarctic Search for Transiting ExoPlanets). The instrument is a fixed 10 cm refractor with a 4kx4k CCD camera in a thermalized box, pointing continuously a 3.88 degree x 3.88 degree field of view centered on the celestial South pole. ASTEP South became fully functional in June 2008 and obtained 1592 hours of data during the 2008 Antarctic winter. The data are of good quality but the analysis has to account for changes in the point spread function due to rapid ground seeing variations and instrumental effects. The pointing direction is stable within 10 arcseconds on a daily timescale and drifts by only 34 arcseconds in 50 days. A truly continuous photometry of bright stars is possible in June (the noon sky background peaks at a magnitude R=15 arcsec-2 on June 22), but becomes challenging in July (the noon sky background magnitude is R=12.5 arcsec?2 on July 20). The weather conditions are estimated from the number of stars detected in the field. For the 2008 winter, the statistics are between 56.3 % and 68.4 % of excellent weather, 17.9 % to 30 % of veiled weather and 13.7 % of bad weather. Using these results in a probabilistic analysis of transit detection, we show that the detection efficiency of transiting exoplanets in one given field is improved at Dome C compared to a temperate site such as La Silla. For example we estimate that a year-long campaign of 10 cm refractor could reach an efficiency of 69 % at Dome C versus 45 % at La Silla for detecting 2-day period giant planets around target stars from magnitude 10 to 15. This shows the high potential of Dome C for photometry and future planet discoveries. [Short abstract

Negative Effects of Copper Oxide Nanoparticles on Carbon and Nitrogen Cycle Microbial Activities in Contrasting Agricultural Soils and in Presence of Plants

Metal-oxide nanoparticles (NPs) such as copper oxide (CuO) NPs offer promising perspectives for the development of novel agro-chemical formulations of pesticides and fertilizers. However, their potential impact on agro-ecosystem functioning still remains to be investigated. Here, we assessed the impact of CuO-NPs (0.1, 1, and 100 mg/kg dry soil) on soil microbial activities involved in the carbon and nitrogen cycles in five contrasting agricultural soils in a microcosm experiment over 90 days. Additionally, in a pot experiment, we evaluated the influence of plant presence on the toxicity of CuO-NPs on soil microbial activities. CuO-NPs caused significant reductions of the three microbial activities measured (denitrification, nitrification, and soil respiration) at 100 mg/kg dry soil, but the low concentrations (0.1 and 1 mg/kg) had limited effects. We observed that denitrification was the most sensitive microbial activity to CuO-NPs in most soil types, while soil respiration and nitrification were mainly impacted in coarse soils with low organic matter content. Additionally, large decreases in heterotrophic microbial activities were observed in soils planted with wheat, even at 1 mg/kg for soil substrate-induced respiration, indicating that plant presence did not mitigate or compensate CuO-NP toxicity for microorganisms. These two experiments show that CuO-NPs can have detrimental effects on microbial activities in soils with contrasting physicochemical properties and previously exposed to various agricultural practices. Moreover, we observed that the negative effects of CuO-NPs increased over time, indicating that short-term studies (hours, days) may underestimate the risks posed by these contaminants in soils