400 ans d'exploration botanique en zone méditerranéenne algérienne Une histoire méconnue et inachevée

Cet article fait une mise au point quasi exhaustive de l'exploration botanique en Algérie. Exploration couronnée, en 1962, par la publication de la flore de Quézel et Santa, dont la révision reste toujours d'actualité

Les forêts d'Algérie, de Césarée la romaine à ce jour.

D'après de nombreux auteurs, les forêts d'Algérie furent jadis luxuriantes. L'état de déliquescence dans lequel elles se retrouvent aujourd'hui, pose la problématique de ce qu'elles ont subi durant les diverses époques de l'histoire de ce pays. Peu d'écrits existent sur le sujet a constitué et en fonction des convictions politiques ou religieuses des auteurs, chaque publication s'accorde à dire que c'est telle ou telle autre période de l'histoire fort tourmentée de ce pays, qui a été déterminante. La situation géographique de celui-ci, a fait qu'il a subi, de tout temps, des invasions, et que ce sera toujours la forêt qui payera le plus lourd tribut. Actuellement, la situation est encore plus complexe, du fait de la mondialisation

Halogen-free flame-retardant compounds. Thermal decomposition and flammability behavior for alternative polyethylene grades

The effect of six halogen-free flame retardant (FR) formulations was investigated on the thermal stability of two low-density polyethylenes (LDPE) and one linear low-density polyethylene (LLDPE), by means of thermogravimetric analysis (TGA) under nitrogen and air atmosphere. The relative data were combined with flammability properties and the overall performance of the FRs was correlated with the type of branching in the polyethylene grades and to their processing behavior. The thermal degradation kinetics was further determined based on the Kissinger and Coats-Redfern methods. In terms of flammability, the addition of a triazine derivative and ammonium polyphosphate at a loading of 35 wt. %. was found to be the most efficient, leading to UL 94 V0 ranking in the case of the LDPE grade produced in an autoclave reactor. - 2019 by the authors.Funding: This publication was made possible by the NPRP award [NPRP 9-161-1-030] from the Qatar National Research Fund (a member of The Qatar Foundation). The statements made herein are solely the responsibility of the author(s)

Welfare effects of unbundling under different regulatory regimes in natural gas markets

In this paper, we develop a theoretical model that enriches the literature on the pros and cons of ownership unbundling vis-a`-vis lighter unbundling frameworks in the natural gas markets. For each regulatory framework, we compute equilibrium outcomes when an incumbent firm and a new entrant compete a` la Cournot in the final gas market. We find that the entrant’s contracting conditions in the upstream market and the transmission tariff are key determinants of the market structure in the downstream gas market (both with ownership and with legal unbundling). We also study how the regulator must optimally set transmission tariffs in each of the two unbundling regimes. We conclude that welfare maximizing tariffs often require free access to the transmission network (in both regulatoy regimes). However, when the regulator aims at promoting the break-even of the regulated transmission system operator, the first-best tariff is unfeasible in both regimes. Hence, we study a more realistic set-up, in which the regulator’s action is constrained by the break-even of the regulated firm (the transmission system operator). In this set-up, we find that, for a given transmission tariff, final prices in the downstream market are always higher with ownership unbundling than with legal unbundling.info:eu-repo/semantics/publishedVersio

Metabarcoding analysis on European coastal samples reveals new molecular metazoan diversity

Although animals are among the best studied organisms, we still lack a full description of their diversity, especially for microscopic taxa. This is partly due to the time-consuming and costly nature of surveying animal diversity through morphological and molecular studies of individual taxa. A powerful alternative is the use of high-throughput environmental sequencing, providing molecular data from all organisms sampled. We here address the unknown diversity of animal phyla in marine environments using an extensive dataset designed to assess eukaryotic ribosomal diversity among European coastal locations. A multi-phylum assessment of marine animal diversity that includes water column and sediments, oxic and anoxic environments, and both DNA and RNA templates, revealed a high percentage of novel 18S rRNA sequences in most phyla, suggesting that marine environments have not yet been fully sampled at a molecular level. This novelty is especially high among Platyhelminthes, Acoelomorpha, and Nematoda, which are well studied from a morphological perspective and abundant in benthic environments. We also identified, based on molecular data, a potentially novel group of widespread tunicates. Moreover, we recovered a high number of reads for Ctenophora and Cnidaria in the smaller fractions suggesting their gametes might play a greater ecological role than previously suspected

Pharmacogenetic profiling and cetuximab outcome in patients with advanced colorectal cancer

<p>Abstract</p> <p>Background</p> <p>We analyzed the influence of 8 germinal polymorphisms of candidate genes potentially related to EGFR signalling (<it>EGFR</it>, <it>EGF</it>, <it>CCND1</it>) or antibody-directed cell cytotoxicity (<it>FCGR2A </it>and <it>FCGR3A</it>) on outcome of colorectal cancer (CRC) patients receiving cetuximab-based therapy.</p> <p>Methods</p> <p>Fifty-eight advanced CRC patients treated with cetuximab-irinotecan salvage therapy between 2001 and 2007 were analyzed (mean age 60; 50 PS 0-1). The following polymorphisms were analyzed on blood DNA: <it>EGFR </it>(CA repeats in intron 1, -216 G > T, -191C > A, R497K), <it>EGF </it>(A61G), <it>CCND1 </it>(A870G), <it>FCGR2A </it>(R131H), <it>FCGR3A </it>(F158V). Statistical analyses were conducted on the total population and on patients with wt KRas tumors. All SNPs were considered as ternary variables (wt/wt <it>vs </it>wt/mut <it>vs </it>mut/mut), with the exception of -191C > A <it>EGFR </it>polymorphism (AA patient merged with CA patients).</p> <p>Results</p> <p>Analysis of skin toxicity as a function of EGFR intron 1 polymorphism showed a tendency for higher toxicity in patients with a low number of CA-repeats (p = 0.058). <it>CCND1 </it>A870G polymorphism was significantly related to clinical response, both in the entire population and in KRas wt patients, with the G allele being associated with a lack of response. In wt KRas patients, time to progression (TTP) was significantly related to <it>EGFR </it>-191C > A polymorphism with a longer TTP in CC patients as compared to others, and to <it>CCND1 </it>A870G polymorphism with the G allele being associated with a shorter TTP; a multivariate analysis including these two polymorphisms only retained <it>CCND1 </it>polymorphism. Overall survival was significantly related to <it>CCND1 </it>polymorphism with a shorter survival in patients bearing the G allele, and to <it>FCGR3A </it>F158V polymorphism with a shorter survival in VV patients (in the entire population and in KRas wt patients). <it>FCGR3A </it>F158V and <it>CCND1 </it>A870G polymorphisms were significant independent predictors of overall survival.</p> <p>Conclusions</p> <p>Present original data obtained in wt KRas patients corresponding to the current cetuximab-treated population clearly suggest that <it>CCND1 </it>A870G polymorphism may be used as an additional marker for predicting cetuximab efficacy, TTP and overall survival. In addition, <it>FCGR3A </it>F158V polymorphism was a significant independent predictor of overall survival.</p

Phylogenetically Widespread Polyembryony in Cyclostome Bryozoans and the Protracted Asynchronous Release of Clonal Brood-Mates

The file attached is the Published/publisher’s pdf version of the articl

A comprehensive structural, biochemical and biological profiling of the human NUDIX hydrolase family

The NUDIX enzymes are involved in cellular metabolism and homeostasis, as well as mRNA processing. Although highly conserved throughout all organisms, their biological roles and biochemical redundancies remain largely unclear. To address this, we globally resolve their individual properties and inter-relationships. We purify 18 of the human NUDIX proteins and screen 52 substrates, providing a substrate redundancy map. Using crystal structures, we generate sequence alignment analyses revealing four major structural classes. To a certain extent, their substrate preference redundancies correlate with structural classes, thus linking structure and activity relationships. To elucidate interdependence among the NUDIX hydrolases, we pairwise deplete them generating an epistatic interaction map, evaluate cell cycle perturbations upon knockdown in normal and cancer cells, and analyse their protein and mRNA expression in normal and cancer tissues. Using a novel FUSION algorithm, we integrate all data creating a comprehensive NUDIX enzyme profile map, which will prove fundamental to understanding their biological functionality