Assessment of Groundwater Quality in the Dogger Aquifer of Poitiers, Poitou-Charentes Region, France

The Poitou-Charentes, located in the Center-West of France, is a region where economy is based mainly on agriculture. This region, made up of 4 Departments (Vienne, Charente, Charente Maritime, Deux-Sèvres), is supplied largely by groundwater exploitation, both for consumption and for irrigation. This resource is thus vital to the region and its preservation is a major issue. The objective of this study is the determination of the groundwater quality in the Dogger aquifer of Poitiers (Vienne Department), which is the main water resource for this area and to achieve a better understanding of the factors influencing groundwater mineralization. Sixty-six wells, distributed over the study area, were sampled and analyzed for major ions (Ca2+, Mg2+, Na+, K+, HCO3-, Cl-, SO42-, NO3-). Data were interpreted using graphical (Piper diagram, binary diagrams) and statistical methods (correlation matrix, principal components analysis). Saturation and chloro-alkaline indices were also computed. It is shown that the groundwater mineralization is mainly associated with Ca2+, K+, HCO3-, Cl-, SO42-, and NO3-. Hydrochemistry of groundwater is determined by both natural processes, and anthropogenic factors. Natural factors are dissolution of carbonate and dolomitic minerals, and cation exchanges with clays, while anthropogenic factors are contaminant infiltration with waste waters and agricultural fertilizers. Nitrate is the main contaminant found in the groundwater and makes this resource unsuitable for consumption at some places.

Air/CO2 cooling garment: Description and benefits of use for subjects exposed to a hot and humid climate during physical activities

The severity of the hot and humid conditions to which miners are exposed increases as the depth of the work site increases.This can cause heat stress that can greatly affect the health and safety of workers.To resolve this,a cooling garment has been developed that uses an atmospheric discharge of liquid CO2 to create a cool microclimate with an average temperature of 12.5(±0.4)℃ beneath the garment.To evaluate the garment's cooling efficiency,19 male subjects participated in an experimental procedure.The two modes,cooling on and off,were compared.Significant physiological differences were found between the two modes after minute 27(p<0.05)until the end of the recovery phase for the heart rate(maximum difference of 10 beats per minute)and the internal body temperature(maximum difference of 0.33℃).It was found that the modes also affected the subjects'perceptions.The ON-mode was associated with better well-being and thermal comfort,and reduced humidity sensation.Perceptions of exertion were lower in the ON-mode condition from minute 2.The findings provide strong evidence of the ability of this cooling garment to reduce heat stress in hot and humid conditions similar to those encountered in deep mines.

The strength model of self-control revisited:Linking acute and chronic effects of exercise on executive functions

Since the 1960＇s, hundreds of articles have been published on the effects of exercise on cognition and more recently on executive functions. A large variety of effects have been observed： acute or long-lasting, facilitating or debilitating. Several theoretical frameworks have been proposed to explain these effects with plausible mechanisms. However, as yet none of these models has succeeded in unifying all the observations in a single framework that subsumes all effects. The aim of the present review is to revisit the strength model of self-control initiated by Baumeister and his colleagues in the 1990＇s in order to extend its assumptions to exercise psychology. This model provides a heuristic framework that can explain and predict the effects of acute and chronic exercise on effortful tasks tapping self-regulation or executive functions. A reconsideration of exercise as a self-control task results from this perspective. A new avenue for future research is delineated besides more traditional approaches.

Template-free synthesis of three-dimensional NiFe-LDH hollow microsphere with enhanced OER performance in alkaline media

Flower-like hierarchical three-dimensional Ni Fe layered double hydroxides hollow microspheres(3D NiFe-LDH HMS),as one kind of novel non-noble metal electrocatalysts,have been fabricated in a templatefree route for water oxidation.Both of the concentration of ammonium fluoride and the reaction time are adjusted to obtain a series of Ni Fe-LDH microspheres,with different internal structures from massive to hollow generated during the hydrothermal treatment,which improve the electrocatalytic activity of the Ni Fe-LDH catalysts towards the evolution reaction of oxygen.The optimized Ni Fe-LDH-0.4M HMS show the excellent OER performance in alkaline electrolyte withη=290 mV@10 mA cm^-2,and a Tafel slope of 51 mV dec-1,which outperforms the benchmark RuO2 catalyst.The possible reason is attributed to the more exposure of active sites,and fast ion transport resulting from the hierarchical hollow structure.

Effects of two medicinal plants Psidium guajava L. (Myrtaceae) and Diospyros mespiliformis L. (Ebenaceae) leaf extracts on rat skeletal muscle cells in primary culture

Crude decoction, aqueous and ethanolic extracts of two medicinal plants （Psidiura guajava and Diospyros raespiliformis）, widely used in the central plateau of Burkina Faso to treat many diseases were evaluated for their antagonistic effects on caffeine induced calcium release from sarcoplasmic reticulum of rat skeletal muscle cells. These different extracts showed a decrease of caffeine induced calcium release in a dose dependent manner. Comparison of the results showed that Psidiura guajava leaf extracts are more active than extracts of Diospyros mespiliformis and that crude decoctions show better inhibitory activity. The observed results could explaine their use as antihypertensive and antidiarrhoeal agents in traditional medicine, by inhibiting intracellular calcium release.

Natural stilbenes effects in animal models of Alzheimer’s disease

Alzheimer’s disease is one of the most frequent neurodegenerative diseases.This pathology is characterized by protein aggregates,mainly constituted by amyloid peptide and tau,leading to neuronal death and cognitive impairments.Drugs currently proposed to treat this pathology do not prevent neurodegenerative processes and are mainly symptomatic therapies.However,stilbenes presenting multiple pharmacological effects could be good potential therapeutic candidates.The aim of this review is to gather the more significant papers among the broad literature on this topic,concerning the beneficial effects of stilbenes (resveratrol derivatives) in animal models of Alzheimer’s disease.Indeed,numerous studies focus on cellular models,but an in vivo approach remains of primary importance since in animals (mice or rats,generally),bioavailability and metabolism are taken into account,which is not the case in in vitro studies.Furthermore,examination of memory ability is feasible in animal models,which strengthens the relevance of a compound with a view to future therapy in humans.This paper is addressed to any researcher who needs to study untested natural stilbenes or who wants to experiment the most effective natural stilbenes in largest animals or in humans.This review shows that resveratrol,the reference polyphenol,is largely studied and seems to have interesting properties on amyloid plaques,and cognitive impairment.However,some resveratrol derivatives such as gnetin C,trans-piceid,or astringin have never been tested on animals.Furthermore,pterostilbene is of particular interest,by its improvement of cognitive disorders and its neuroprotective role.It could be relevant to evaluate this molecule in clinical trials.

Mesenchymal stromal cells' role in tumor microenvironment:involvement of signaling pathways

Mesenchymal stromal cells(MSCs) are adult multipotent stem cells residing as pericytes in various tissues and organs where they can differentiate into specialized cells to replace dying cells and damaged tissues. These cells are commonly found at injury sites and in tumors that are known to behave like "wounds that do not heal." In this article, we discuss the mechanisms of MSCs in migrating, homing, and repairing injured tissues. We also review a number of reports showing that tumor microenvironment triggers plasticity mechanisms in MSCs to induce malignant neoplastic tissue formation, maintenance, and chemoresistance, as well as tumor growth. The antitumor properties and therapeutic potential of MSCs are also discussed.

Hydrochemical and Isotopic Characteristics of the Basement Aquifer in the Wadi Fira Area, Eastern Chad

The Wadi-Fira region in eastern Chad is facing dramatic water supply problems, related to the climatic semi-arid context and the reception of refugees from the Darfour, which has increased the local population by 22% these last years. Expansion of agglomerations (temporary new towns), development of agricultural and pastoral practices together with the augmentation of the population have led to dramatic water needs. The basement aquifer of Wadi-Fira constitutes the main source of water supply. However, little is known about this system. Within this context, this work aims at better understanding and identifying hydrogeochemical processes and their relations to groundwater quality within this complex environment, and groundwater recharge mechanisms. 31 groundwater samples were collected at two sites, Am Zoer and Guereda-Iriba, from hand dug wells and deep wells. Major chemical elements were analyzed on all samples and stables isotopes (oxygen-18 and deuterium) on 17 samples. Various methods were used to interpret the hydrochemical data (descriptive and multivariate statistics, Piper and Schoeller diagrams, scatter plots, minerals saturation indices). The stable isotopes were interpreted using conventional IAEA methods. The results permitted to differentiate the laterite reservoir from the deep fractured reservoir. The main process controlling groundwater mineralization is water-rocks interaction and natural minerals dissolution. Ion exchanges, evaporation and anthropogenic activities have also a moderate impact on groundwater quality. Based on isotopes data, it is concluded that groundwater in the basement aquifer is related with modern rainfall. These results provide further insights into this basement aquifer, which is a vital resource for the region of Wadi-Fira.

Assessment of Groundwater Resources in a Complex Volcanic Reservoir with Limited Data Sets in a Semi-Arid Context Using a Novel Stochastic Approach. The Goda Volcanic Massif, Republic of Djibouti

This work focuses on the modeling and evaluation of water resources in complex aquifer systems and the use of scarce data. The modeling work is developed based on the GLUE (Generalized Likelihood Uncertainty Estimation) method. This method is still little used in hydrogeology, although its applications in other disciplines such as hydrology proved quite efficient. The study site, located in the Republic of Djibouti (Horn of Africa), is represented by the volcanic massif of Goda. The hydraulic properties of this massif are highly heterogeneous since they are associated with fracturing and weathering of the geological formations. The data are too few to enable a conventional modeling approach of this volcanic system. The implementation of the GLUE method in a numerical groundwater flow model allowed developing a stochastic analysis of the spatial distribution of the hydraulic conductivity and the recharge modalities of this complex volcanic system. The hydraulic conductivities range from 10-6 to 10-8 m·s-1 for the basalt and the rhyolite formations (values are yet generally lower for rhyolites) and are higher than 5 × 10-7 for the sedimentary formations. In addition, considering diffuse recharge as the main mechanism by which the precipitation reaches the aquifer results in more consistent groundwater head simulations than considering only indirect recharge. The average recharge amount estimated for the Goda aquifer system is 28 mm·yr-1. The results led to a numerical representation of this system, with the least uncertainty. This model was able to estimate the available water resources of this system. This result is important because the Goda system supplies water to the city of Tadjourah. Assessment of available resources is vital for the future development of this city. From a methodological point of view, the GLUE method proved very promising for water resources assessment in complex hydrogeological systems for which little data are available.

Hydrogeochemical Assessment of Groundwater in the Precambrian Rocks, South Eastern Desert, Egypt

This work refers to the characterization of the hydrochemistry of the southern part of the Eastern Desert in Egypt, on the basis of physico-chemical properties of groundwater occurring in the fractured Precambrian rocks inland and in sedimentary formations on the coastline of the Red Sea. Thirty-five groundwater samples have been collected from the study area for hydrochemical investigations to understand the sources of dissolved ions and assess the chemical quality of the groundwater. Several methods were used to interpret the hydrochemical data, i.e. graphical methods, principal components analysis, ions exchanges indices and saturation indices of various minerals. The results show that the major ionic relationships are Na+ > Ca2+ > Mg2+ and Cl- > > HCO3- and that groundwater chemical characteristics are controlled by natural geochemical processes but also, to a lesser extent, by anthropogenic activities. Natural minerals dissolution, ion exchanges and evaporation play a prominent role in the ion enrichment of groundwater. A comparison of groundwater quality in relation to WHO water quality standards proved that most of the water samples are not totally suitable for drinking water purpose.

Contribution to the Design of a Pottery Kiln Using as Fuel a Mixture of Cellulosic and Plastic Materials: Influence of the Proportion of Plastic on the Emissions of NO, CO₂, O₂

This paper concerns the study of the influence of the proportion of plastic from polyethylene, on the yields of gas emissions during the combustion of the mixture of “millet stalks and polyethylene plastic bags”, in a prototype of kiln of potters. During these investigations, we looked at the rate of residual oxygen (O2) and emissions of carbon dioxide (CO2) and nitrogen monoxide (NO), as a function of primary air flow (Q1) and secondary airflow (Q2). The potter’s kilns are considered those fueled by natural air flow. The primary air flows ranging from 45 to 85 Nm3?h 1 and secondary air flows from 20 to 60 Nm3?h 1. To conduct this numerical study, the model used is “reactor” based on the code CHEMKIN II. The modeled area is composed into a multitude of perfectly stirred reactors (PSR) and the kinetic model has 893 species and 113 reversible chemical reactions. The results show that in our test conditions, the increasing of the rate of plastic in the mixture produces a decrease of the residual oxygen content, due to higher oxygen consumption regardless of the airflow. The CO2 emissions are an increasing function of the rate of plastic (polyethylene) in the fuel mixture. Finally, NO emissions are increasing functions of the mass of plastic for a proportions less than or equal to 20%, and are essentially controlled by the temperature of the reactional medium.

Cross-Layer Energy Analysis and Proposal of a MAC Protocol for Wireless Sensor Networks Dedicated to Building Monitoring Systems

In a sustainable development context, the monitoring systems are essential to study the building energy performances. With the recent technology advances, these systems can be based on wireless sensor networks, where the energy efficiency is the main design challenge. To this end, most of the studies focus on low power Medium Access Control (MAC) protocols to reduce the overall energy consumption of a network. Nevertheless, the performances assessment of these protocols is generally not performed in a realistic way, and does not take into account the performances of the other layers of the OSI model. In this paper, we propose a cross-layer methodology to assess the real performances of a MAC protocol by taking into account the traffic volume, the synchronization losses and more particularly the physical layer performances through a Bit Error Rate (BER) criterion. The simulation results demonstrate clearly the physical layer impact on a sensor lifetime. Finally, the proposal of an energy efficient MAC protocol for a wireless sensor network dedicated to an application of building monitoring is proposed.

秦岭药用真菌区系研究

旨在积累秦岭山区药用真菌资源的基础资料,同时,也是该地区野生真菌资源的开发、利用和保护前提。此次研究采用野外踏查、室内查对标本和校对相关文献资料的方法对秦岭山区药用真菌种质资源及其区系特点进行了初步的研究和探讨。结果显示,秦岭共有药用真菌196种,其中隶属于39科90属,含10种以上的科有4科,共107种,占全部种数的54.59%,分别为多孔菌科、红菇科、口蘑科和马勃科;含5种及5以上的属有8属,共5 9种,占总种数的30.09%,依次为红菇属、乳菇属、栓菌属、木层孔菌属、鬼伞属、马勃属、粘盖牛肝菌属、秃马勃属;从属的区系地理成分上可划分为广布成分(67.78%)、泛热带成分(4.44%)、热带亚洲-热带非洲成分(1.59%)和北温带成分(26.67%)4个分布型,其中以广布成分为主,表现典型温带区系特征。从其药理作用上分析,主要有抗癌、抗菌消炎、舒筋活络、止血、调节免疫力、养胃、补益等作用。

Developmental pathways associated with cancer metastasis:Notch,Wnt,and Hedgehog

Master developmental pathways, such as Notch, Wnt, and Hedgehog, are signaling systems that control proliferation, cell death,motility, migration, and stemness. These systems are not only commonly activated in many solid tumors, where they drive or contribute to cancer initiation, but also in primary and metastatic tumor development. The reactivation of developmental pathways in cancer stroma favors the development of cancer stem cells and allows their maintenance, indicating these signaling pathways as particularly attractive targets for efficient anticancer therapies, especially in advanced primary tumors and metastatic cancers. Metastasis is the worst feature of cancer development. This feature results from a cascade of events emerging from the hijacking of epithelial-mesenchymal transition, angiogenesis, migration, and invasion by transforming cells and is associated with poor survival, drug resistance, and tumor relapse. In the present review, we summarize and discuss experimental data suggesting pivotal roles for developmental pathways in cancer development and metastasis, considering the therapeutic potential. Emerging targeted antimetastatic therapies based on Notch, Wnt, and Hedgehog pathways are also discussed.

The exercise-cognition relationship:A virtuous circle

Exercise and health psychology have generated 2 sets of empirical studies guided by separate theory-driven axes.The first axis focuses on the causal relationship between chronic exercise and cognition and,more particularly,high-level cognitive functions such as executive functions(EFs).The second axis examines factors influencing the adherence process to physical activity(PA).Research conducted during the past decade shows that these 2 topics are closely linked,with EFs and effortful control playing a pivotal role in the bidirectional relationship linking PA and mental/brain health.The present article supports the idea that an individual engaged in the regular practice of effortful PA initiates a virtuous circle linking PA and effortful control in a bidirectional way.On the one hand,chronic exercise leads to an improvement of EFs and effortful control.On the other hand,gains in EFs and effortful control effectiveness lead to a reciprocal facilitation of the maintenance of PA over time.Some limitations and perspectives to this effort hypothesis are proposed in the last part of the article.

Natural polyphenols effects on protein aggregates in Alzheimer＇s and Parkinson＇s prion-like diseases

Alzheimer＇s and Parkinson＇s diseases are the most common neurodegenerative diseases. They are characterized by protein aggregates and so can be considered as prion-like disease. The major components of these deposits are amyloid peptide and tau for Alzheimer＇s disease, α-synuclein and synphilin-1 for Parkinson＇s disease. Drugs currently proposed to treat these pathologies do not prevent neurodegenerative processes and are mainly symptomatic therapies. Molecules inducing inhibition of aggregation or disaggregation of these proteins could have beneficial effects, especially if they have other beneficial effects for these diseases. Thus, several natural polyphenols, which have antioxidative, anti-inflammatory and neuroprotective properties, have been largely studied, for their effects on protein aggregates found in these diseases, notably in vitro. In this article, we propose to review the significant papers concerning the role of polyphenols on aggregation and disaggregation of amyloid peptide, tau, α-synuclein, synphilin-1, suggesting that these compounds could be useful in the treatments in Alzheimer＇s and Parkinson＇s diseases.

Oxygen vacancies engineering by coordinating oxygen-buffering CeO_(2) with CoO_(x) nanorods as efficient bifunctional oxygen electrode electrocatalyst

CeO_(2)decorated CoOx rod-like hybrid,supported onto holey reduced graphene(CoOx/CeO_(2)/RGO)composite,was fabricated via a surfactant-assisted route.Its corresponding electrocatalytic performance towards oxygen reduction/evolution reactions(ORR and OER)was systematically investigated in alkaline electrolyte.Structural,morphological and compositional studies revealed changes in electronic and surface properties when CeO_(2)was introduced as an oxygen buffer material.The oxygen vacancies effectively enhanced the electrocatalytic activity,while the synergistic effect of co-catalyst CeO_(2),CoOx activecenters,and defective graphene with many voids facilitate the charge/mass transfer,making CoOx/CeO_(2)/RGO an efficient and stable bifunctional electrocatalyst for OER/ORR with△E=0.76 V(△E=E10mAcm.-2OER-E_(1/2).ORR).This parameter is 70 mV and 270 mV lower than CoOx/RGO and the benchmark Pt/C,respectively.In addition,the OER/ORR bifunctionality of CoOx/CeO_(2)/RGO composite outperforms that of Pt/C catalyst in a H2-O_(2)micro fuel cell platform.

Bifunctional oxygen electrode cobalt–nickel sulfides catalysts originated from intercalated LDH precursors

Bimetallic cobalt-nickel sulfide nanoparticles anchored on S-,N-codoped holey carbon nanosheets(CoNiS-T@NCFs)with a hydrangea-like morphology,were synthesized via a confinement synthesis route,in which an intercalated LDH precursor was subjected to the interlayer-confined carbonization and host-layer sulfurization.The phase transformation and structure evolution(e.g.,atom site occupancy,crystallite size,and cell volume)of the CoNi-S-T@NCFs electrocatalysts,as a function of sulfurization temperatures,were confirmed by X-ray diffraction and Rietveld analyses.The sulfur vacancies effectively enhance the electrocatalytic activity,while the synergistic effect of(Co,Ni)7 S8 alloy and S,N-codoped carbon matrix facilitates the electron transfer and accelerates reaction kinetics,making CoNi-S-900@NCFs an efficient and stable bifunctional electrocatalyst for oxygen reduction reaction(ORR).The rich highvalence Co(Ⅲ)and Ni(Ⅲ)of CoNi-S-900@NCFs facilitates the in-situ transformation of the metal(oxy)hydroxides intermediates with high catalytic activity for oxygen evolution reaction(OER).Thus,with a bifunctional parameter,ΔE,of 0.75 V(E_(j=10,OER)-E_(1/2,ORR)),this electrocatalyst slightly outperforms the state-of-the-art commercial Pt/C+RuO_(2)/C catalyst(ΔE=0.76 V)in alkaline medium.This work demonstrates the influence that the sulfurization temperature has on the relationship between the structure and electrocatalytic performance of bimetallic sulfides prepared by the synthesis strategy using the intercalated LDH precursor.This strategy can be extended to prepare other chalcogenides with binary or ternary transition metals.

纵向通风隧道内火灾烟气流动的控制(英文)

讨论了纵向通风隧道火灾和相关烟气形成现象。利用计算机流体动力模型模拟烟气流动,获得可以与试验数据进行比较的预测结果。在Richardson数字基础上,采用了不同参考稳定值,结果发现,直接利用火灾热释放速率所获得的温度值会产生最有用的结果。试验结果与数值预测结果的比较发现,两者吻合较好。笔者验证了利用容积测定火源模拟火灾的情况。结果的准确性很大程度上取决于对墙和屋顶的热传递。