184 research outputs found

    Effet du glyphosate sur les parametres physiologiques du latex et les proprietes technologiques du caoutchouc des heveas (gt 1, pb 217, pr 107) dans le cadre de la lutte contre les loranthaceae en Cote d’Ivoire

    Get PDF
    L’objectif de cette étude est d’évaluer l’effet du Glyphosate sur les paramètres physiologiques du latex et sur les propriétés  technologiques du caoutchouc dans le cadre de la lutte contre les Loranthaceae en hévéaculture. Pour ce faire, 10 ml d’une solution de Glyphosate 360 g/l ont été injectés à cinq plants d’hévéas des clones GT 1, PB 217 et PR 107 parasités par les Loranthaceae. Diverses méthodes appropriées ont été utilisées pour déterminer la proportion des paramètres physiologiques des latex et les propriétés technologues des caoutchoucs. L’effet du Glyphosate sur les paramètres physiologiques du latex des hévéas traités et sur les propriétés technologiques du caoutchouc a été évalué et comparé aux paramètres physiologiques et aux propriétés technologiques des caoutchoucs des hévéas témoins n’ayant pas reçus de matière active (Glyphosate). De plus, les valeurs obtenues ont été comparées aux valeurs de référence. Il ressort de cette étude que, dans la lutte contre les Loranthaceae en plantation hévéicole,  l’injection de 10 ml de Glyphosate (360 g/L) à l’hévéa n’affecte ni les paramètres physiologiques du latex, ni les propriétés technologiques du caoutchouc. Mots clés : Glyphosate, hévéa, Loranthaceae, paramètres physiologiques du latex, propriétés technologiques du caoutchouc   English Title: Effect of glyphosate on the physiological parameters of latex and the technological properties of rubber from rubber tree (GT 1, PB 217, PR 107) in the control of loranthaceae in Cote d’Ivoire The aim of this study is to evaluate the effects of Glyphosate on the physiological properties of the latex and on the technological properties of the rubber in the control of Loranthaceae in rubber trees cultivation. To do this, 10 ml of a 360 g/l solution of Glyphosate were injected into five rubber plants of clones GT 1, PB 217 and PR 107 parasitized by Loranthaceae. Various appropriate methods have been used in order to determine physiological parameters of latex and the technological properties of rubber. The effect of Glyphosate on the physiological parameters of latex and on the technological properties of rubber was evaluated and compared to the  physiological parameters of latex and technological properties of rubbers those did not receive any active ingredient (Glyphosate). The obtained values were also compared to reference values. It appears from this study that, in the control of Loranthaceae in rubber plantation, the injection of 10 ml of Glyphosate (360 g/L) into rubber trees does not affect either the physiological parameters of latex or the technological properties of rubber. Keywords : Glyphosate, rubber tree, Loranthaceae, physiological parameters of latex, rubber technological propertie

    Haemostatic Properties of Chrysophyllum Caïnito L. (Sapotaceae) in Wistar Rat

    Get PDF
    The measure of certain blood parameters makes it possible to detect certain pathologies such as the hemophilia and leukemia among patients. Indeed, the aggregating and antiaggreganting activity of certain substances are known. It is a question in this work of checking the effect of the aqueous extract of Chrysophyllum cainito (AECc) on blood. It is a comparative study between AECc and two products of synthesis known for purpose which are the dicynone and the aspirin in vivo in the rats wistar specie Rattus norvegicus. The time of bleeding (TB), the number of blood plates, the red blood corpuscle rate, of hemoglobin, the hematocrit and the sedimentation test (TS) were evaluated. During the first week, the evolution of the time of bleeding (TB) is not significant for all the animals. The second week and until the end of the treatment, the TB drops for the animals treated with EACc in an amount-dependant way. Thus the fall is of 4% for the amounts of 300 mg/kg b.w, 17.4% for the amounts of 500 mg/kg b.w and 30.43% for the amounts of 1000 mg/kg b.w at the end of the treatment. In the animals treated with the dicynone, the fall reaches 41.55% at the end of the thirty days of treatment. On the other hand, in the rats treated with the aspirin, the TB increases as from the second week and reached the rise of 17.40% at the end of the thirty days. On the blood plates, AECc varies their number of manner proportions dependant as of the first week on treatment. The number of blood plates increases by 07.69% and 15.38% for the amount of AECc of 300 mg/kg b.w, 15th and 30th day. The amount of 500 mg/kg b.w of AECc makes increase the number of plates of 09.89%, 21.97%, and 25.16%, respectively 5th, 15th and 30th day.The concentration of AECc of 1000 mg/kg b.w involves an increase in the plates of 22.31%, 27.36% and 33.07%, respectively with 5th, 15th and 30th day of treatment. The dicynone is managed with the rats with the amount of 500 mg/kg b.w the number of blood plates passes thus from 910±85.83 to 915±88.0, 918±87.0 then 920±92.0; 5th, 15th and 30th days of treatment is 0.55%, 0.88% and 1.09%. This variation is nonsignificant. On the other hand the aspirin managed with the rats with the amount of 500 mg/kg b.w cause a drop in the number of blood plates as of the 5th days with 900±88.2 then with 889±82.2 15th and 750±80.6 the 30th. These drops successive represent rates by -1%,-2.30% and -17.58%. The other factors such as the number of red blood corpuscles the rate of hemoglobin, the hematocrit and also the sedimentation test do not vary significantly before and during the treatment

    Transcriptional Infidelity Promotes Heritable Phenotypic Change in a Bistable Gene Network

    Get PDF
    Bistable epigenetic switches are fundamental for cell fate determination in unicellular and multicellular organisms. Regulatory proteins associated with bistable switches are often present in low numbers and subject to molecular noise. It is becoming clear that noise in gene expression can influence cell fate. Although the origins and consequences of noise have been studied, the stochastic and transient nature of RNA errors during transcription has not been considered in the origin or modeling of noise nor has the capacity for such transient errors in information transfer to generate heritable phenotypic change been discussed. We used a classic bistable memory module to monitor and capture transient RNA errors: the lac operon of Escherichia coli comprises an autocatalytic positive feedback loop producing a heritable all-or-none epigenetic switch that is sensitive to molecular noise. Using single-cell analysis, we show that the frequency of epigenetic switching from one expression state to the other is increased when the fidelity of RNA transcription is decreased due to error-prone RNA polymerases or to the absence of auxiliary RNA fidelity factors GreA and GreB (functional analogues of eukaryotic TFIIS). Therefore, transcription infidelity contributes to molecular noise and can effect heritable phenotypic change in genetically identical cells in the same environment. Whereas DNA errors allow genetic space to be explored, RNA errors may allow epigenetic or expression space to be sampled. Thus, RNA infidelity should also be considered in the heritable origin of altered or aberrant cell behaviour

    Integrated supply–demand energy management for optimal design of off-grid hybrid renewable energy systems for residential electrification in arid climates

    Get PDF
    The growing research interest in hybrid renewable energy systems (HRESs) has been regarded as a natural and yet critical response to address the challenge of rural electrification. Based on a Bibliometric analysis performed by authors, it was concluded that most studies simply adopted supply-side management techniques to perform the design optimization of such a renewable energy system. To further advance those studies, this paper presents a novel approach by integrating demand-supply management (DSM) with particle swarm optimization and applying it to optimally design an off-grid hybrid PV-solar-diesel-battery system for the electrification of residential buildings in arid environments, using a typical dwelling in Adrar, Algeria, as a case study. The proposed HRES is first modelled by an in-house MATLAB code based on a multi-agent system concept and then optimized by minimizing the total net present cost (TNPC), subject to reliability level and renewable energy penetration. After validation against the HOMER software, further techno-economic analyses including sensitivity study are undertaken, considering different battery technologies. By integrating the proposed DSM, the results have shown the following improvements: with RF = 100%, the energy demand and TNPC are reduced by 7% and 18%, respectively, compared to the case of using solely supply-side management. It is found that PV-Li-ion represents the best configuration, with TNPC of 23,427andcostofenergy(COE)of0.2323,427 and cost of energy (COE) of 0.23 /kWh. However, with lower RF values, the following reductions are achieved: energy consumption (19%) and fuel consumption or CO 2 emission (57%), respectively. In contrast, the RF is raised from 15% (without DSM) to 63% (with DSM). It is clear that the optimal configuration consists of wind-diesel, with COE of 0.21 $/kWh, smaller than that obtained with a stand-alone diesel generator system. The outcomes of this work can provide valuable insights into the successful design and deployment of HRES in Algeria and surrounding regions

    Matter manipulation with extreme terahertz light: Progress in the enabling THz technology

    Get PDF
    Terahertz (THz) light has proven to be a fine tool to probe and control quasi-particles and collective excitations in solids, to drive phase transitions and associated changes in material properties, and to study rotations and vibrations in molecular systems. In contrast to visible light, which usually carries excessive photon energy for collective excitations in condensed matter systems, THz light allows for direct coupling to low-energy (meV scale) excitations of interest, The development of light sources of strong-field few-cycle THz pulses in the 2000s opened the door to controlled manipulation of reactions and processes. Such THz pulses can drive new dynamic states of matter, in which materials exhibit properties entirely different from that of the equilibrium. In this review, we first systematically analyze known studies on matter manipulation with strong-field few-cycle THz light and outline some anticipated new results. We focus on how properties of materials can be manipulated by driving the dynamics of different excitations and how molecules and particles can be controlled in useful ways by extreme THz light. Around 200 studies are examined, most of which were done during the last five years. Secondly, we discuss available and proposed sources of strong-field few-cycle THz pulses and their state-of-the-art operation parameters. Finally, we review current approaches to guiding, focusing, reshaping and diagnostics of THz pulses. (C) 2019 The Author(s). Published by Elsevier B.V

    Pan-cancer analysis of whole genomes

    Get PDF
    Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale(1-3). Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4-5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter(4); identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation(5,6); analyses timings and patterns of tumour evolution(7); describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity(8,9); and evaluates a range of more-specialized features of cancer genomes(8,10-18).Peer reviewe
    corecore