Optimal Two-Step Prediction in Regression

High-dimensional prediction typically comprises two steps: variable selection and subsequent least-squares refitting on the selected variables. However, the standard variable selection procedures, such as the lasso, hinge on tuning parameters that need to be calibrated. Cross-validation, the most popular calibration scheme, is computationally costly and lacks finite sample guarantees. In this paper, we introduce an alternative scheme, easy to implement and both computationally and theoretically efficient

Mapping Expert Uncertainties or Confidence Level in Mining Risk Prevention Plans

Mining Risk Prevention Plans have been developed in France in order to deal with “Post-Mining” issues in a rapid and operational way. This inevitably implies that the final result of those risk analyses might contain a significant part of uncertainty. The study presented herein introduces a framework and some tools that allow experts to express the confidence they have in their evaluation and raise the main difficulties they face in their daily work

Treatment of old disused mine openings

International audienceAccording to French regulations, the main objectives for the treatment of old abandoned mines consist of : preventing collapses and dangerous subsidence, controlling mine gas emissions and closing old abandoned mine openings. In the Herault coal basin, underground exploitation started very early, in particular by the way of shallow adits dug in hillsides. Today more than 600 adits have been listed on old maps but a lot of them have not yet been precisely located. Charbonnages de France and INERIS have analyzed all risks generated by these old openings and have established a methodology able to determine the closure procedure which can guarantee the safety of the opening. This methodology can be adapted to an adit (size, state of...) and to the physical characteristics of the site (gas, water, location...). In order to limit the number of configurations, two of the above factors have been retained : the state and the location of the gallery. After analyzing all the possible configurations, closure principles have been determined for each of them. The paper : discusses geographical and historical background of the Herault basin exploitation, list the specific parameters which influence the choice of process able to secure the adits, present the general methodology used. Finally, the treatment of an adit located under inhabited areas is presented

The extraforaminal juxtafacet cyst as a rare cause of L5 radiculopathy: a case report.

STUDY DESIGN: This is a report of a case. OBJECTIVE: To document the clinical, radiographic, and histologic characteristics of a lumbar extraforaminal juxtafacet cyst. SUMMARY OF BACKGROUND DATA: Spinal juxtafacet cysts develop most frequently at the dorsal aspect of the zygapophysial joint, sometimes in the posterolateral area of the canal. In one case, they have been described in the foraminal and extraforaminal region. METHODS: Description of the case report. RESULT: The authors report one case of a strictly extraforaminal juxtafacet cyst responsible for L5 sciatica. CONCLUSIONS: Juxtafacet cysts of the spine represent an infrequent cause of sciatica, usually when they grow in the canal, or more exceptionally when they occupy the foraminal or extraforaminal areas

Neuropsychological analysis of gait disturbances during dual task in MCI patients

peer reviewedaudience: researcher, professional, studen

Background

PROCEEDINGS A rich internet application for remote visualization and collaborative annotation of digital slides in histology and cytolog

Hydrolysis of Ammonia-Borane over Ni/ZIF-8 Nanocatalyst: High Efficiency, Mechanism, and Controlled Hydrogen Release

Non-noble metal nanoparticles are notoriously difficult to prepare and stabilize with appropriate dispersion, which in turn severely limits their catalytic functions. Here, using zeolitic imidazolate framework (ZIF-8) as MOF template, catalytically remarkably efficient ligand-free first-row late transition-metal nanoparticles are prepared and compared. Upon scrutiny of the catalytic principles in the hydrolysis of ammonia-borane, the highest total turnover frequency among these first-row late transition metals is achieved for the templated Ni nanoparticles with 85.7 molH2 molcat -1 min-1 at room temperature, which overtakes performances of previous non-noble metal nanoparticles systems, and is even better than some noble metal nanoparticles systems. Mechanistic studies especially using kinetic isotope effects show that cleavage by oxidative addition of an O-H bond in H2O is the rate-determining step in this reaction. Inspired by these mechanistic studies, an attractive and effective "on-off" control of hydrogen production is further proposed.Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicada

Expression of FGF-2 in neural progenitor cells enhances their potential for cellular brain repair in the rodent cortex

Strategies to enhance the capacity of grafted stem/progenitors cells to generate multipotential, proliferative and migrating pools of cells in the postnatal brain could be crucial for structural repair after brain damage. We investigated whether the over-expression of basic fibroblast growth factor 2 (FGF-2) in neural progenitor cells (NPCs) could provide a robust source of migrating NPCs for tissue repair in the rat cerebral cortex. Using live imaging we provide direct evidence that FGF-2 over-expression significantly enhances the migratory capacity of grafted NPCs in complex 3D structures, such as cortical slices. Furthermore, we show that the migratory as well as proliferative properties of FGF-2 over-expressing NPCs are maintained after in vivo transplantation. Importantly, after transplantation into a neonatal ischaemic cortex, FGF-2 over-expressing NPCs efficiently invade the injured cortex and generate an increased pool of immature neurons available for brain repair. Differentiation of progenitor cells into immature neurons was correlated with a gradual down-regulation of the FGF-2 transgene. These results reveal an important role for FGF-2 in regulating NPCs functions when interacting with the host tissue and offer a potential strategy to generate a robust source of migrating and immature progenitors for repairing a neonatal ischaemic corte

The GTPase TcRjl of the human pathogen Trypanosoma cruzi is involved in the cell growth and differentiation

AbstractThe protozoan parasite Trypanosoma cruzi, the etiological agent of Chagas Disease, undergoes through a complex life cycle where rounds of cell division and differentiation occur initially in the gut of triatominae vectors and, after transmission, inside of infected cells in vertebrate hosts. Members of the Ras superfamily of GTPases are molecular switches which play pivotal regulatory functions in cell growth and differentiation. We have previously described a novel GTPase in T. cruzi, TcRjl, which belongs to the RJL family of Ras-related GTP binding proteins. Here we show that most of TcRjl protein is found bound to GTP nucleotides and may be locked in this stage. In addition, we show that TcRjl is located close to the kinetoplast, in a region corresponding possibly to flagellar pocket of the parasite and the expression of a dominant-negative TcRjl construct (TcRjlS37N) displays a significative growth phenotype in reduced serum medium. Remarkably, overexpression of TcRjl inhibits differentiation of epimastigotes to trypomastigote forms and promotes the accumulation of intermediate differentiation stages. Our data suggest that TcRjl might play a role in the control of the parasite growth and differentiation