Using Multiple Linear Regression and Artificial Neural Network Techniques for Predicting CCR5 Binding Affinity of Substituted 1-(3, 3-Diphenylpropyl)-Piperidinyl Amides and Ureas

Quantitative structure–activity relationship (QSAR) models were developed to predict for CCR5 binding affinity of substituted 1-(3, 3-diphenylpropyl)-piperidinyl amides and ureas using multiple linear regression (MLR) and artificial neural network (ANN) techniques. A model with four descriptors, including Hydrogen-bonding donors HBD(R7), the partition coefficient between n-octanol and water logP and logP(R1) and Molecular weight MW(R7), showed good statistics both in the regression and artificial neural network with a configuration of (4-3-1) by using Bayesian and Leven-berg-Marquardt Methods. Comparison of the descriptor’s contribution obtained in MLR and ANN analysis shows that the contribution of some of the descriptors to activity may be non-linear.

Development of new cowpea(Vigna unguiculata)mutant genotypes,analysis of their agromorphological variation,genetic diversity and population structure

Cowpea is one of the most important legume grains in the sub-Saharan region of Africa used for human consumption and animal feed,but its production is hampered by biotic and abiotic constraints raising the need to broaden its genetic basis.For this purpose,seeds of two cowpea varieties Melakh and Yacine were irradiated with 300 and 340 Gy of gamma-ray,respectively.The developed mutant populations were agromorphologically characterized from M5 to M7,while the genetic diversity of the latter was evaluated using 13 ISSR markers.Based on the agromorphological characterization,variation of flower color,pod length,seed coat color,and seed weight with 78.01,68.29,94.48,and 57.58%heritability,respectively,were recorded in the mutant lines.PCA analyses allowed to identify the elite mutants based on their agromorphological traits,while Pearson’s correlation results revealed a positive correlation between yield and yield component traits.Three subpopulations were identified through STRUCTURE analyses,but the assignment of the individuals in each group was improved using DAPC(Discriminant Analysis of Principal Components)analysis.Analysis of Molecular Variance revealed that the majority(85%)of the variance rather existed within groups than among(15%)groups.Finally,our study allowed us to select new promising mutant genotypes that could be tested for multi-locational trials to evaluate their agronomic performance.

Contribution of Electric Tomography, Chemical and Isotopic Tools to the Understanding of the Resilience and Salinization of Wetlands along the Northern Coast of the Cape-Verde Peninsula: The Case of the Retba Lake

On the northern coast of the Cape Verde peninsula, Lake Retba is one of the few depressions that have preserved its water body due to the drought that plagued the Sahel in the 1960s. The aim of this article is to understand the resilience of the lake to the drought. For this purpose, a deep knowledge of interactions between the different components of the hydro-system, namely: lake, dune tablecloth, ponds and ocean is necessary. The use of electrical resistivity tomography (ETR) and chemical and isotopic tools yielded conclusive results. Electrical tomography of resistivity (ETR) shows throughout the coastal dune a superposition between fresh and salt water, with even a predominance of salt water at the level of the old canal. The chemistry of the major ions and isotopes confirms this contact between the saltwater bison of the sea and the lake by showing a superposition of the fresh/brackish waters on the salty waters of the bevel, which, in turn, are found in the very salty waters influenced by the lake. This translates a feeding of the lake by the sea through the bevel. At the canal level, this feeding is done, on the surface, by means of ponds whose water characteristics show that they constitute an outcrop of the bevel. The freshwater body of the coastal dune that floats on salt water in the form of a lens also flows into the lake. The feeding of the lake, by the sea through the bevel and the ponds, and by the water table, is therefore effective and attested by all the methods used in this work. It allowed the resilience of the lake against the drought. This inflow of seawater into the lake is at the origin of its salinization and therefore of the salt that settles on the bottom. This study shows that the survival of the lake also depends on safeguarding the ponds located in the north of the lake.

Near-infrared reflectance spectroscopy reveals wide variation in major components of sesame seeds from Africa and Asia

Sesame is an important oilseed crop in Africa and Asia, owing to its high nutritional quality seed and market value. Variation in sesame seed components including oil, oleic acid,linoleic acid, and protein was investigated by near-infrared reflectance spectrometry in 139 samples collected from different countries. Oil and protein contents were between 40.8%and 60.3%(mean 53.0%) and 15.5% to 25.5%(mean 20.4%), respectively. Linoleic acid,ranging from 31.8% to 52.4%(mean 46%) was more abundant than oleic acid(31.8%–50.6%,mean 38.1%). Light-seeded samples displayed higher nutritional quality, as they were richer in oil, protein, and linoleic acid than dark seeds. Samples from Africa had higher oil and linoleic acid contents, while Asian samples had higher oleic content. The analysis revealed West African sesame cultivars containing especially high levels of seed components, which may command high market values. Two clusters of sesame samples grouped by seed composition were obtained, including one cluster with high oil and oleic acid content and the other with high protein and linoleic acid content. This study revealed that sesame samples from Africa and Asia harbor high variation for major seed components and also provided background information for breeding high-nutrition varieties according to the demands of sesame seed markets.

Adsorption recovery of Ag(Ⅰ) and Au(Ⅲ) from an electronics industry wastewater on a clay mineral composite

The aim of this work is to investigate the ability of an adsorbent of a clay mineral composite to remove and recover gold and silver ions from wastewater.The composite was prepared by mixing phosphogypsum(PG),obtained from an industrial waste,and a natural clay mineral.The materials were characterized before and after use in adsorption by several techniques.Batch adsorption experiments were carried out,and the effects of the contact time and the pH and temperature of solution on the removal processes were investigated.The optimum pH for the adsorption was found to be 4.The adsorption of these metal ions reached equilibrium after 2 h of contact.The pseudo-first-and the pseudo-second-order kinetic models,as well as the Freundlich and the Langmuir isotherm equations,were considered to describe the adsorption results.The maximum adsorbed amount of 85 mg·g^-1 Ag(I)and 108.3 mg·g?1 Au(III)was found.The recovery of the adsorbed gold and silver ions from the adsorbent was also analyzed.Strong acids appeared to be the best desorption agents to recover gold and silver ions.The use of aqua regia gave regeneration rates close to 95.3%and 94.3%for Ag(I)and Au(III),respectively.Finally,the removal of gold and silver ions from an industrial wastewater was tested in batch experiments,and percentage recoveries of 76.5%and 79.9%for Ag(I)and Au(III),respectively,were obtained.To carry out the industrial application of the proposed methodology,an economic viability study is required.

Effect of fluorinated additives or co-solvent on performances of graphite//LiMn2O4 cells cycled at high potential

Herein,a comprehensive study of electrochemical performances of the combined effect of fluorinated additives;fluoroethylene carbonate(FEC);and tris(2,2,2-trifluoroethyl) phosphite(TTFP) or the 2,2,2-trifluoroethyl methyl carbonate(TFEMC) as co-solvent,on Graphite//LiMn2O4 cells cycled at high potential is reported.On one side,each additive has a specific function,the FEC is dedicated to the negative electrode and the TTFP to the opposite one.The electrolyte mixture with(4% FEC+1% TTFP) additive has shown the best ability to reduce fading of the LiMn2O4 electrode,especially at high rates.On the other side,by studying the comparative thermal and transport properties of the formulated electrolytes with different proportions of TFEMC,we demonstrate that the difference in charge distribution of EMC and TFEMC molecules induced by the presence of fluorine atoms,modifies the solvation model of the Li+cation,and changes its behavior at the CEI interface and impact strongly the electrochemical performances.Finally,the EIS investigation of the LMO/electrolyte interfaces in the presence of TFEMC demonstrates that despite a spontaneous chemical reactivity of the TFEMC at the cathode interface over time,the conductive and good quality CEI is formed,which positively impact the cyclability.This study shows that against LMO surface phenomena,the combination in adequate proportions of fluorinated additives or solvent can be a solution not only to avoid the oxidative reactivity of LMO-cathode,but also to prevent its harmful consequences on the Li-metal or graphite-anode by controlling the solvation of lithium-ion.

Mesorif Gabbros(External Rif, North Morocco): Ophiolitic Suture Witness or a “Newly Discovered” Manifestation of the Central Atlantic Magmatic Province?

The Rif Mountain located in Northern Morocco represents the westernmost extremity of the Peri-Mediterranean Alpine orogenic system.This belt is classically subdivided into:1)Internal zones(or Internal Rif which is an allochthonous metamorphic domain known worldwide thanks to the presence of large peridotite outcrops);2)flysch zones(sediments corresponding to the original cover of the Maghrebian Tethys);and 3)External zones(or External Rif representing the North African margin remnants).The External Rif is itself subdivided into Prerif,Mesorif and Intrarif domains from the South to the North and is composed by Upper Triassic to Cenozoic sediments structured in a nappe stack.Mafic rock intrusions were reported in this External Rif since the preliminary geological studies even if they were wrongly mapped as"granites".Later careful fieldwork and mapping studies specified nevertheless their gabbroic nature.A more recent petrological and geochemical study of a few outcrops of those gabbroic intrusions conducted the corresponding authors,encouraged by the presence of ultramafic rocks(Beni Malek serpentines)in the eastern part of the External Rif to consider those gabbros as oceanic and so,associated to"an ophiolitic suture".Nevertheless,a recent and extended survey on the architecture and the rifting history of the Mesozoic margin of the Maghrebian Tethys focusing mainly on the Mesorif domain favor another interpretation.The detailed petrography of those mafic intrusions(mainly gabbros+dolerites and rarely extrusive rocks);their geochemical fingerprints and mainly their geochronological data(ages around 200 Ma based on U-Pb zircon LA-ICP dating)all together indicate clearly that those mafic intrusions are rather a"newly discovered"manifestation of the Central Atlantic Magmatic Province activity"CAMP"in the External Rif belt.The CAMP magmatism has been largely well described and characterized in all the other geological domains of Morocco(Anti-Atlas,High Atlas,Middle Atlas and Meseta)but never described until the date in the Rif belt which highlights the importance of the results reported here.

Evaluation of Performance and Emission Characteristics of Biodiesel Fuel Produced from Rapeseed Oil

The objective of the present study is to examine and compare the performance and emission characteristic of two biodiesel fuels produced from rapeseed oil via transesterification method.Tested biodiesel fuels(ROME(Rapeseed Oil Methyl Ester)and ROEE(Rapeseed Oil Ethyl Ester))were selected based on their properties obtained from an optimization of transesterification conditions.A Yanmar diesel engine has led to evaluating their performance parameters such as fuel consumption rate,exhaust gas temperature and emission characteristic corresponding to nitrogen oxides(NOx),carbone monoxide(CO)and carbon dioxide(CO2).A comparative analysis was carried out using normal diesel fuel tested in same experimental conditions.Fuel consumption rate was measured by observing the volumetric rate from the fuel tank of the engine supported by stopwatch.The exhaust gas temperature and emission characteristic were measured simultaneously by using a testo 350 flue gas analyzer.According to the results,biodiesel fuels showed a higher fuel consumption rate and exhaust gas temperature under an increase of engine speed.They also exhibited lower NOx emission with a slight rise in CO and CO2 emission compared to mineral diesel fuel.ROME exhibited low emission gas compared to ROEE and mineral diesel.It can be evaluated as a promising alternative fuel for diesel engine.

Production and Characterization of Biodiesel from Rapeseed Oil through Optimization of Transesterification Reaction Conditions

In this study,biodiesel fuel was produced from rapeseed oil via transesterification method.The optimum reaction conditions were determined by varying alcohol type and its concentration considering their influence on the yield and properties of produced biodiesel.Methanol and ethanol were alcohol used in the transesterification process.The density of biodiesel was measured at 15℃according to EN ISO 12185 test method and its viscosity was determined at 40℃by using a Brookfield digital viscometer(DV-II+Pro).Shimadzu Auto-Calculating Bomb calorimeter CA-4AJ was used to measure the high heating value.The optimum transesterification conditions found were alcohol:oil ratio of 18:1,1%of potassium hydroxide as catalyst,60 min of reaction time,60℃of reaction temperature and stirring speed of 650 rpm.Biodiesel properties under these conditions satisfied the regulatory standards and are slightly similar to those of mineral diesel tested in same conditions.Using methanol gives better results compared to ethanol.

Evaluation of the Opuntia dillenii as Natural Coagulant in Water Clarification:Case of Treatment of Highly Turbid Surface Water

This study was performed in laboratory scale and consisted of the using of aqueous Opuntia dillenii solution for the clarification of very turbid surface water (Turbidities varying between 186 NTU and 418 NTU). This plant from Cactaceae family was used as a natural coagulant for the different clarification tests. The preliminary phytochemical Screening of the powder of this plant showed that it contains tanins, saponins and mucilages. Flocculation and coagulation tests showed that Opuntia dillenii can be used in highly turbid water treatment. The removal efficiency varied from 89% to 93% for the turbidity and suspended solids, and from 4% to 15% for the obvious color in water when we used the optimum values of this natural coagulant (1 mL to 10 mL). The successive addition of this natural coagulant and the lime, gave a better elimination of turbidity and suspended solids, and a good reduction for the color. The removal efficiency of the turbidity and suspended solids became more than 95% and the one of the color between 67% and 94%.

Inflation Playing by John Lagrangian

Our goal is to reproduce inflation through the coupling between the non-minimal first derivative of the scalar field and the Einstein tensor in which we introduced a potential. We analyse the inflation by examining the equation of state, the expansion parameter and the scale factor. We have shown that when the potential is proportional to the field φ and proportional to the square of the field, inflation does not appear;but when the potential is an exponential function of the scalar field, this model brings up inflation. Inflation does not occur when the time t is near minus infinity but it is noticed a few units of Planck time.

LC-MS Identification and Preliminary Pharmacological Study of the Aqueous and Ethanol Extracts from Combretum glutinosum Perr ex DC.(Combretaceae)

Background:Combretum glutinosum is a plant whose leaves are consumed as a vegetable and used in traditional medicine for the treatment of microbial infections.Objective:The present study was designed to identify the compounds in C.glutinosum leaves extracts,and evaluate its antimicrobial activity,antioxidant ability and its toxicity in Artemia salina larvae in vitro.Methods:The aqueous and ethanol extracts obtained from the leaves of the plant as well as known compounds previously isolated and characterized from the leaves of C.glutinosum were tested on eleven different microbial strains.The antioxidant activity of the extracts was evaluated by the Ferric Reducing Antioxidant Power method and the larval toxicity on Artemia salina larvae was also detected.Phytochemical screening and HPLC-DAD-HRESI-MS analysis were performed on the extracts to characterize its chemical composition.Results:When tested at a concentration of 20 mg‧mL^(−1),the extracts of C.glutinosum leaves strongly inhibited the growth of the bacterial strains with an inhibition diameter ranging from 7.25 mm to 44 mm,superior to those of the positive controls(tetracycline at 30μg‧mL^(−1)and amikacin at 30μg‧mL^(−1)),inhibition diameters from 15 mm to 33 mm.The evaluated larval toxicity demonstrated that it had no harmful effects on Artemia salina larvae.The extracts present a good antioxidant activity at a concentration of 0.17 and 1.33 mmol ascorbic acid(per gram of extract)for the aqueous and ethanol extracts,respectively.However,none of the compounds tested at 500μg‧mL^(−1)were able to show good activity on the 11 reference strains.Phytochemical analysis revealed the presence of alkaloids,polyphenols,steroids,triterpenoids,reducing compounds,etc.in both extracts.The HPLC-DAD-HRESI-MS analyses revealed 18 compounds in the ethanol extract,from which 3 were identified,15 compounds in the aqueous extract from which 5 could be identified.Conclusion:The present work has shown that C.glutinosum extracts can be a good source of antimicrobial agents.They also possess the antioxidant property with absence of toxicity on A.salina larvae.A further bio-guided study could allow the identification and isolation of the active ingredients.

Phylogenetic analysis of avian infectious bronchitis virus isolates from Morocco:a retrospective study(1983 to 2014)

Dear Editor,Infectious bronchitis(IB),one of the most common and difficult poultry diseases,is caused by a gammacoronavirus named infectious bronchitis virus(IBV).IBV frequently causes respiratory and/or renal diseases in chickens and egg production losses in hens.IB has

Potassium sources, microorganisms and plant nutrition: Challenges and future research directions

Until recently,potassium(K)has not received considerable attention because of the general belief that soils contain ample amounts of this element.In addition,low rates of K fertilizer application in agriculture have led to rapid depletion of K in the rhizosphere soil in many underdeveloped countries.This results in various negative impacts,including preventing optimum utilization of applied nitrogen and phosphorus fertilizers.To compensate for these losses,massive use of K fertilizers in agriculture has been suggested.Potassium fertilizers are manufactured from rock minerals,particularly sylvite(KCl)and carnallite(KCl·MgCl2·6H2O).Unfortunately,to date,there is no cost-effective technology available for converting rock minerals into potassic fertilizers.Potassium-solubilizing microorganisms(KSMs)can release K from soil/minerals into plant-available forms,which could be a sustainable option.The possibility of using KSMs as efficient biofertilizers to improve crop production has been increasingly highlighted by researchers.In this review,the existing forms of K in soils and their availability and dynamic equilibrium are discussed.In addition,different K fertilizers and their advantages and disadvantages for crops are described.Furthermore,the microorganisms usually reported as K solubilizers,the research progress on KSMs,and future insights on the use of these KSMs in agriculture are reviewed.Screening and analyses of the published literature show that organic acid production is the common mechanism of K solubilization by bacteria and fungi.This review may serve as a proposal for the future research avenues identified here.

Combined effects of earthworms and biochar on PAHs-contaminated soil remediation:A review

Polycyclic aromatic hydrocarbons(PAHs)in soil pose a threat to the health of humans and other organisms due to their persistence.The remediation method of combined application of biochar and earthworms has received growing attention owing to its effectiveness in PAHs removal.However,the earthworm-biochar interaction and its influence on PAHs in soil has not been systematically reviewed.This review focuses on the effectiveness of combined application of earthworms and biochar in the remediation of PAHs-contaminated soils and the underlying mechanisms,including adsorption,bioaccumulation,and biodegradation.Earthworm-biochar interaction activates the functional microorganisms in soil and the PAHs-degrading microorganisms in earthworm guts,promoting PAHs biodegradation.This review provides a theoretical support for the combined application of biochar and earthworms in the remediation of PAHs-contaminated soils,points out the limitations of this remediation method,and finally shows the prospects for future research.

Grazing effects on vegetation dynamics in the savannah ecosystems of the Sahel

Background The savannah ecosystems of Sahel have experienced continuous and heavy grazing of livestock for centuries but still,their vegetation response to grazing pressure remains poorly understood.In this study,we analysed the herbaceous plant dynamics,measured by species diversity,composition,cover,and biomass in response to grazing pressure in the savannah ecosystems of Sahel.In Senegal,we selected four savannah sites represented with high,moderate,light and no grazing intensity levels.Transect survey methods were used for sampling the vegetation data within each of the sites.Species richness and composition were analysed using species accumulation curve and multivariate analyses.Furthermore,we used General Linear Models and a piecewise Structural Equation Model(pSEM)to examine the relationships between grazing intensity,vegetation cover,diversity and biomass.Results The herbaceous species diversity and composition varied significantly among the different grazing intensity levels(p<0.001).The plant species composition shifted from the dominance of grass cover to the dominance of forb cover with increasing grazing pressure.Moreover,the attributes of species diversity,herbaceous biomass,and ground cover were higher on sites with low grazing than sites with high and moderate grazing intensity.Across all sites,species diversity was positively related to total biomass.The pSEM explained 37%of the variance in total biomass and revealed that grazing intensity negatively influenced total biomass both directly and indirectly through its negative influence on species diversity.Conclusions Managing grazing intensity may lead to higher plant production and higher mixed forage establishment in the dryland savannah ecosystems.This information can be used to support land management strategies and promote sustainable grazing practices that balance the needs of livestock with the conservation of ecosystem health and biodiversity.

Morphological characterization and habitat suitability modeling of the goat population of Benin under climate change scenarios

Background:Insufficient knowledge of the genetic and phenotypic diversity in the local Beninese goat population combined with the lack of understanding of its adaptive capacity to ongoing environmental and societal changes hampers the development of strategies for better management and genetic improvement.The objective of this study was to establish the current geographical distribution of goats in Benin based on their morphology and model the potential habitat suitability of the three known main goat phenotypes(i.e.,Djallonkégoat or TypeⅠ,Sahelian goat or TypeⅡ,and their Crossbreeds or TypeⅢ)under climate change scenarios.Ten qualitative and 26 linear body measurements were taken on 2114 adult female goats sampled across the three vegetation zones of the country.Fifteen ratios were generated from the quantitative variables.The data were analyzed using generalized linear model procedures followed by multiple comparisons of least-squares means and multivariate analytical methods,including canonical discrimination analysis and hierarchical ascendant classification.Each goat was then assigned to one of the three aforementioned main goat phenotypes following its morphological characteristics and according to the a priori cluster membership defined in the previous step.The Maximum Entropy algorithm was used to model the current and future distribution of the three goat phenotypes under climate change scenario using the Representative Conservation Pathways 4.5 and 8.5.Results:All linear body measurements varied among vegetation zones.In the discriminant function analysis,71%of the measured individuals were correctly classified in their vegetation zone of origin by seven measured variables and three ratios.The cluster procedure analysis revealed two groups of goats subdivided into the three main phenotypes.The modeling results showed that the currently highly favorable habitats were distributed in the South for TypeⅠ,in the North for TypeⅡ,and both South and North for TypeⅢ.However,under climate change scenarios,the favorable habitats for TypeⅠdecreased while those of TypesⅡandⅢincreased.Conclusions:The results of this study confirm the spatial variation of the goat population in Benin.The habitat suitability model can be used to support decision-making toward better management of goat genetic diversity in Benin.

Malaria epidemiology in Kobeni department,southeastern Mauritania from 2015 to 2017

Background:Plasmodium falciparum malaria is endemic in the southern sahelian zone of Mauritania where intense internal and trans-border human and livestock movement occurs.The risk of importation and spread of drugresistant parasites need to be regularly assessed in this region.The objective of the study was to assess the recent malaria situation near the Mauritania-Mali border.Methods:Between February 2015 and December 2017,patients with fever or history of fever during the previous 48 h,presenting at the health centre of Kobeni city,were screened for malaria using a rapid diagnostic test(RDT)and microscopic examination of blood smears.The diagnosis was later confirmed by PCR.Cohen’s kappa statistics was used to estimate the degree of agreement between diagnostic methods.Fisher’s exact test was used to compare proportions.The odds ratio was calculated to measure the association between the use of bed nets and malaria infection.Results:A total of 2326 febrile patients(mean age,20.2 years)were screened for malaria.The presence of malaria parasites was detected by RDT and microscopy in 53.0%and 49.3%of febrile patients,respectively,and was confirmed by PCR in 59.7%(45 missing data).Of 1361 PCR-positive samples,1205(88.5%)were P.falciparum,47(3.5%)P.vivax,and 99(7.3%)P.falciparum-P.vivax mixed infection.Malaria transmission occurred mostly during and shortly after the rainy season.The annual rainfall was relatively low in 2016(267 mm)and 2017(274 mm),compared to 2015(448 mm),and coincided with a decline in malaria prevalence in 2016–2017.Although 71.8%of febrile patients reported to possess at least one bed net in the household in our questionnaire,its reported use was not protective against malaria infection(odds ratio:1.1,95%CI:0.91–1.32).Conclusions:Our study confirmed that P.falciparum is the dominant species in the sahelian zone and that malaria transmission is seasonal and associated with rainfall in this zone.The application of the current national policy based on rapid and reliable malaria diagnosis,case management with artemisinin-based combination therapy,intermittent preventive treatment for pregnant women,distribution and use of long-lasting insecticide impregnated bed nets,and the planned introduction of seasonal malaria chemoprevention for all children under 6 years old is expected to sustainably reduce malaria transmission in this zone.