Exploring groundwater quality in semi-arid areas of Algeria:Impacts on potable water supply and agricultural sustainability

Groundwater quality assessment is important to assure safe and durable water use.In semi-arid areas of Algeria,groundwater represents the main water resource for drinking water supply of the rural population as well as for irrigation of agricultural lands.Groundwater samples from wells and springs were collected from the Gargaat Tarf and Annk Djemel sub-watersheds of the Oum El Bouaghi,Algeria,and were analyzed and compared with the World Health Organization(WHO)standards.Results showed that most of the measured physical and chemical parameters exceeded the quality limits according to the WHO standards.Groundwater had a slightly alkaline water pH(7.00-7.79),electrical conductivity>1500μS/cm,chloride>500 mg/L,calcium>250 mg/L,and magnesium>155 mg/L.Water quality index(WQI)results showed that 68%of the area had excellent water quality,24%of the samples fell into good category,and only 8%were of poor quality and unsuitable for human consumption.Six wells in the area showed bacterial contamination.Total coliforms(453.9(±180.3)CFU(colony-forming units)/100 mL),fecal coliforms(243.2(±99.2)CFU/100 mL),and fecal streptococci(77.9(±32.0)CFU/100 mL)loads were above the standard limits set by the WHO.These results confirmed that water resources in the study area were strongly influenced by anthropogenic activities and were not recommended for consumption as drinking water.

Generating Sets of the Complete Semigroup of Binary Relations Defined by Semilattices of the Class Σ8(X, 5)

In this article, we study generating sets of the complete semigroups of binary relations defined by X-semilattices of unions of the class Σ8(X, 5). Found uniquely irreducible generating set for the given semigroups and when X is finite set formulas for calculating the number of elements in generating sets are derived.

Investigation of UV photosensor properties of Al-doped SnO_(2) thin films deposited by sol-gel dip-coating method

Transparent conducting aluminum doped tin oxide thin films were prepared by sol-gel dip coating method with differ-ent Al concentrations and characterized by X-ray diffraction (XRD), atomic force microscopy (AFM), UV-Vis spectrophotometry and photoconductivity study. The variation observed in the properties of the measured films agrees with a difference in the film's thickness, which decreases when Al concentration augments. X-ray diffraction analysis reveals that all films are polycrystal-line with tetragonal structure, (110) plane being the strongest diffraction peak. The crystallite size calculated by the Debye Scher-rer’s formula decreases from 11.92 to 8.54 nm when Al concentration increases from 0 to 5 wt.%. AFM images showed grains uni-formly distributed in the deposited films. An average transmittance greater than 80% was measured for the films and an en-ergy gap value of about 3.9 eV was deduced from the optical analysis. Finally, the photosensitivity properties like current-voltage characteristics, ION/IOFF ratio, growth and decay time are studied and reported. Also, we have calculated the trap depth energy using the decay portion of the rise and decay curve photocurrent.

Do aeolian deposits and sand encroachment intensity shape patterns of vegetation diversity and plant functional traits in desert pavements?

The effects of sand encroachment on composition,diversity,and functional patterns of vegetation in drylands are rarely studied,and yet addressing these aspects is important to deepen our understanding of the biodiversity conservation.This study aimed to investigate the effect of sand encroachment on plant functional biodiversity of desert pavements(gravel deserts)in the Sahara Desert of Algeria.Plants were sampled and analyzed in three desert pavements with different levels of sand encroachment(LSE)and quantity of aeolian deposits(low,LLSE;medium,MLSE;and high,HLSE).Within the sample-plot area(100 m^(2)),density of every plant species was identified and total vegetation cover was determined.Plant taxonomic and functional diversity were analyzed and compared between LSE.Result showed that 19 plant species in desert pavements were classified into 18 genera and 13 families.Asteraceae and Poaceae were the most important families.The species Anabasis articulata(Forssk)Moq.characterized LLSE desert pavements with 11 species,whereas Thymelaea microphylla Coss.&Durieu ex Meisn.and Calobota saharae(C&D)Boatwr.&van Wyk were dominant species of desert pavements with MLSE(14 species)and HLSE(10 species),respectively.The highest values of species richness and biodiversity were recorded in desert pavements with MLSE,while low values of these ecological parameters were obtained in desert pavements with HLSE.Desert pavements with LLSE were characterized with the highest values of species abundances.Plant communities were dominated by chamaephytes,anemochorous,arido-active,and competitive stress-tolerant plants.The increase in LSE along the gradient from LLSE to HLSE induced significant changes in plant community variables including decreases in plant density,plant rarity,lifeform composition,morphological type,and aridity adaptation.Desert pavements with HLSE favor the degradation of vegetation and trigger biodiversity erosion.

External Bacterial Flora and Antimicrobial Susceptibility Patterns of Staphylococcus spp. and Pseudomonas spp. Isolated from Two Household Cockroaches, Blattella germanica and Blatta orientalis

A study was performed to estimate the prevalence of the external bacterial flora of two domestic cockroaches （Blattella germanica and Blatta orientalis） collected from households in Tebessa （northeast AIgeria）.Three major bacterial groups were cultured （total aerobic, enterobacteria, and staphylococci） from 14 specimens of cockroaches, and antibiotic susceptibility was tested for both Staphylococcus and Pseudomonas isolates. Culturing showed that the total bacterial load of cockroaches from different households were comparable （P〈0.001） and enterobacteria were the predominant colonizers of the insect surface, with a bacterial load of （2.1×10^5 CFU/insect）, whereas the staphylococci group was the minority. Twenty-eight bacterial species were isolated, and susceptibility patterns showed that most of the staphylococci isolates were highly susceptible to chloramphenicol, gentamycin, pristinamycin, ofloxacin, clindamycin, and vancomycin; however, Pseudomonas strains exhibited resistance to amoxicillin/clavulanic acid, imipenem, and the second-generation antibiotic cephalosporin cefuroxime.

Stability of a Delayed SIQRS Model with Temporary Immunity

This paper addresses a time-delayed SIQRS model with a linear incidence rate. Immunity gained by experiencing the disease is temporary;whenever infected, the disease individuals will return to the susceptible class after a fixed period of time. First, the local and global stabilities of the infection-free equilibrium are analyzed, respectively. Second, the endemic equilibrium is formulated in terms of the incidence rate, and locally asymptotic stability. Finally we use the adomian decomposition method is applied to the system epidemiologic. This method yields an analytical solution in terms of convergent infinite power series.

Bacterial extracts and bioformulates as a promising control of fruit body rot and root rot in avocado cv. Hass

At least 20-40% of annual losses of avocado crops are caused by pathogenic fungi.The chemical treatments of these diseases are inefficient,cause environmental pollution and are increasingly restricted by international laws.This work aimed to assess the biocontrol capacity of a bacterial extract to protect avocado fruits and plants from pathogen infections.Extracts from the bacterial isolate Serratia sp.ARP5.1 were obtained from liquid fermentations in a biorreactor.A body rot postharvest infection model with Colletotrichum gloeosporioides on fruits was developed.Moreover,packaging conditions were simulated using the bacterial extract and the commercial fungicide prochloraz as a positive control.Additionally,seedlings infections with Phytophthora cinnamomi were performed on two types of avocado(West Indian race and cv.Hass).The Area Under Disease Progress Curve(AUDPC) was recorded using the bacterial extract and a commercial product with fosetyl-aluminium as treatments.The bacterial extract significantly reduced infections by C.gloeosporioides on injured avocado fruits at 31.1 μg mL^-1.Intact fruits were also protected against body rot infections at the same concentration and showed no significant differences with the commercial fungicide.On the other hand,AUDPC in the seedlings was significantly reduced with the extract treatment at 3 μg mL^-1 compared to the control.However,a possible phytotoxicity effect of the extract was evidenced in the seedlings and confirmed by pathogen recovery and tests on Raphanus sativus seedlings.Finally,formulations of the extracts(emulsion and emulsifiable concentrate) were prepared,and bioactive stability was assessed for 8 wk.The emulsion formulates demonstrated very stable bioactivity against P.cinnamomi.The extract and the emulsion formulate showed promising results for the control of avocado pathogens.New bioproducts based on this type of active principles could be developed for the benefit of avocado industry.

Optimization of Extraction Conditions of Some Phenolic Compounds from White Horehound (<i>Marrubium vulgare</i>L.) Leaves

This research was aimed to optimize the extraction conditions of three phenolic compounds: total phenolics, flavonoids and condensed tannins, from White Horehound’s leaves (Marrubium vulgare L.). Distilled water and different organic solvents such as: methanol, ethanol and acetone, were used, with various concentrations (20% - 80%, v/v), temperatures (20&deg;C - 60&deg;C) and extraction times (30 - 450 min). Results showed that the maximum total phenolics amounts (293.34 ± 14.60 mg gallic acid equivalent/g dry weigh), were obtained with 60% aqueous methanol at 25&deg;C for 180 min;total flavonoids (79.52 ± 0.55 mg catechin equivalent/g dry weigh) with 80% aqueous methanol at 20&deg;C for 450 min, and condensed tannins (28.15 ± 0.80 mg catechin equivalent/g dry weigh) with 60% aqueous acetone at 50&deg;C and for 180 min. ANOVA test showed the significant effect (***P < 0.001) of the extraction conditions tested on phenolic compounds. The Principal Component Analysis (PCA) exhibited the positive effect of low temperatures on total phenolics and flavonoids extraction, and the effect of high temperatures on the condensed tannins extraction. The Response Surface Methodology (RSM) provided predicted values of extraction conditions and maximum polyphenols amounts similar to those obtained experimentally.

Rapid increase in numbers and change of land-use in two expanding Columbidae species(Columba palumbus and Streptopelia decaocto)in Algeria

Background: Investigating population ecology of urban bird species,particularly the invasive and expending spe?cies,is the key for the success of urban management and planning strategies.Methods: Populations of two Columbidae species,the Woodpigeon(Columba palumbus) and the Eurasian Collared Dove(Streptopelia decaocto),were monitored from 1992 to 2010 in the Algiers Sahel,the Mitidja Plain and surround?ing areas(Northern Algeria).Monitoring of species densities was performed by the mapping?plot method.The foraging flight routes of Woodpigeon and the distribution of Eurasian Collared Dove were assessed by systematic observations.Results: The number of counted birds was statistically constant at first years of the survey,and then increased sig?nificantly,beginning from low numbers,their densities accelerated sharply between 2001 and 2006,then reached to an equilibrium state.The significant increase in Woodpigeon's population could be explained by the reduced hunt?ing pressure and by species adaptation to new food resources provided by nearby agriculture.Indeed,monitoring of flight directions of the species revealed the use of agricultural landscapes and habitats,which is a good indicator explaining adaptation and trophic niche of the species.The occurrence of the Eurasian Collared Dove in Algiers began in 2000.Its density experienced a rapid increase with similar trend pattern as that of Woodpigeon.Its distributional range is confined mainly in suburban environments of the Mitidja Plain.Conclusion: The modifications of habitats,urbanization increase and the lessening of hunting in the Mitidja Plain facilitated the rapid expansion of the Eurasian Collared Dove and Woodpigeon as well contributed to the increase in their numbers over time.

GLOBAL EXISTENCE AND ASYMPTOTIC BEHAVIOR OF SOLUTIONS FOR SOME COUPLED SYSTEMS VIA A LYAPUNOV FUNCTIONAL

The purpose of this work is to study the global existence and asymptotic behavior of solutions to a coupled reaction-diffusion system describing epidemiological or chemical situations. Our analytical proofs are based on the Lyapunov functional methods.

EXISTENCE AND BOUNDEDNESS OF SOLUTIONS FOR SYSTEMS OF QUASILINEAR ELLIPTIC EQUATIONS

This article sets forth results on the existence and boundedness of solutions for quasilinear elliptic systems involving p-Laplacian and q-Laplacian operators.The approach combines Schaefer's fixed point as well as Moser's iteration procedure.

Magnetic and Electronic Properties of Double Perovskite Ba2SmNbO6 without Octahedral Tilting by First Principle Calculations

The structural, magnetic and electronic properties of the double perovskite Ba2SmNbO6 （for the simple cubic structure where no octahedral tilting exists anymore） are studied using the density functional theory within the generalized gradient approximation as well as taking into account the on-site Coulomb repulsive interaction. The total energy, the spin magnetic moment, the band structure and the density of states are calculated. The optimization of the lattice constants is 8.5173 A, which is in good agreement with the experimental value 8.5180 A. The calculations reveal that Ba2SmNbO6 has a stable ferromagnetic ground state and the spin magnetic moment per molecule is 5.00μB/f.u. which comes mostly from the Sin3＋ ion only. By analysis of the band structure, the compound exhibits the direct band gap material and half-metallic ferromagnetic nature with 100% spin-up polarization, which implies potential applications of this new lanthanide compound in magneto-electronic and spintronic devices.

Model Identification and Control of Evapotranspiration for Irrigation Water Optimization

Water conservation starts from rationalizing irrigation,as it is the largest consumer of this vital source.Following the critical and urgent nature of this issue,several works have been proposed.The idea of most researchers is to develop irrigation management systems tomeet the water needs of plants with optimal use of this resource.In fact,irrigation water requirement is only the amount of water that must be applied to compensate the evapotranspiration loss.Penman-Monteith equation is the most common formula to evaluate reference evapotranspiration,but it requiresmany factors that cannot be available in many cases.This leads to a trend towards behavior model estimation.System identification with control is one of the most promising applications in this axis.The idea behind this proposal depends on three stages:First,the estimation of reference evapotranspiration(ET0)by a linear ARX model,where temperature,relative humidity,insolation duration and wind speed are used as inputs,and ET0 estimated by Penman-Monteith equation as output.The results show that the values estimated by thismethodwere in good agreement with the measured data.The second part of this paper is tomanage the quantity of water.For this purpose,two controllers are used for testing,lead-lag and PID.To adjust the first controller and optimize the choice of its parameters,Nelder-Mead algorithm is used.In the last part,a comparative study is done between the two used controllers.

Does melanin-based plumage coloration reflect health status of free-living birds in urban environments?

Background:Ecological functions and processes in urban ecosystems are governed by various human activities.City-adapted and city-exploiting animal species are expected to present certain specific behavioral and physiological traits in comparison to city-avoiders or conspecific individual frequenting less urbanized or rural environments.A trait of high importance,the plumage color polymorphism has been selected as the main study model and was correlated with different morphological and physiological parameters to highlight its importance in determining the possible health status of urban Feral Pigeons(Columba livia)in North African urban habitats.Methods:Different body morphometrics,hematological and hemoparasitic parameters were quantified on freeliving Feral Pigeons in urban environments of northern Algeria.Moreover,plumage melanin-based coloration(MBC)was measured and the data collected at the individual scale was correlated with the previous parameters using linear and non-linear modeling approaches.Results:Plumage MBC scores of the sampled Feral Pigeons ranged between 0.3%and 74.8%.Among the 12 morphological traits measured,body weight,tail length and total length were deemed to be positively correlated with MBC.Darker morphs appeared to have more hemoparasites compared to lighter pigeons.Quite the same observation goes with the immunity but with non-linear trends.The number of monocytes and granulocytes increased with the increase in MBC levels in lighter morphs,while pigeons with high MBC scores exhibited negative relationships between MBC levels and the number of white blood cells.Conclusions:Despite the existence of a number of studies demonstrating phenotypic directional selection,further studies are undoubtedly necessary to understand in detail the underlying mechanisms in species life-history strategies between differently colored individuals.Findings of this correlative study open exciting perspectives revealing that MBC can be considered a good indicator of and health status and adaptation strategies to changes in urban environments.

Validated Method for the Detection of Three Phthalates Derived from Marine Invertebrates

This study represents, detailly, the validated method for the extraction and quantification of widespread phthalic acid esters (PAEs) bis(2-ethylhexyl) phthalate (DEHP), di-n-butyl phthalate (DBP) and di-n-octyl phthalate (DnOP) from solitary ascidians collected from a marine environment. The extraction was based on a pressurized liquid extraction method, using n-hexane as the solvent to extract the target PAEs from dry biological tissues, and was performed in an accelerated solvent extraction instrument. The average recovery of 89.2% was obtained from samples subjected to a pressure of ~1500 psi and 120°C in two 10-min cycles. GC-MS was used for quantification, conducted in single-ion monitoring mode. Following careful and rigorous cleanup procedures to prevent cross-contamination from laboratory glassware, PAE standards showed signals with good specificity. The obtained limits of detection were 130, 122 and 89 ng/g for DEHP, DBP and DnOP, respectively. Accordingly, the calculated limits of quantification were 394, 370 and 270 ng/g for DEHP, DBP and DnOP, respectively. The obtained linearity ranged from 5.4 to 269 ng/ml (equivalent to 135 - 6725 ng/g dry weight), with R2 ≥ 0.998. Concentrations in the range of 200 to 9000 and 400 to 5000 ng/g sample dry weight, for DEHP and DBP, respectively, were obtained from the ascidians. No DnOP was detected in any of the samples. These results indicate that the method presented in this study is applicable for detection of low and trace concentrations of the target PAEs in samples collected from a marine organism, which can serve as a bioindicator of plastic contamination.

Concentration of Platinum Group Elements during the Early Earth Evolution: A Review

Numerous unique geological processes [1] took place during the early Earth evolution;several of them, especially those occurring in the Hadean—Early Archean and later, are reflected in the modern geological (geophysical, geochemical, etc.) pattern. One such significant enigmatic feature is the preservation of extremely dense and heavy platinum group elements (PGEs): Pt, Pd, Rh, Ru, Ir, Os. Concentration of PGEs during this period could have taken place in two ways: 1) presence of particular matter capable of preserving PGEs near the earth's surface, 2) transportation of PGEs by magma flows from deep lithospheric (asthenospheric) layers (slabs) to the subsurface. Clearly, much of the dense and heavy PGEs did not sink through to the Earth’s mantle (core) at the time of the magma-ocean, and occur near Earth’s surface in abundances for formation of ore deposits with PGE concentrations found to be 2 - 3 orders of magnitude greater than those in their host media. Their enrichments are associated in numerous cases with such enigmatic phenomena as formation of anorthosites and anorthosite-bearing layered magmatic intrusions. PGE deposits and mineralization zones are also found in associations with chromitites, dunites and serpentinites. In this review, problems related to the initial concentration and preservation of PGEs, their association with anorthosites, and formation of layered intrusions are discussed in detail. The main aim of this article is analysis of the requirements—initial concentration and preservation of PGE and PGM (Platinum Group Minerals) during the early Earth evolution, as well as examination of the distribution behavior of some PGEs in different ore deposits and meteorites. It is supposed that meteoritic bombardment of Earth has played a significant role in formation of PGEs deposits. Some conclusions made in this article may be useful for developing and enhancing strategies of prospecting for PGEs deposits.

Environmental Exposure to Glyphosate and Reproductive Health Impacts in Agricultural Population of Argentina

Argentina annually utilizes 240,000 tones of glyphosate in industrial agriculture and a change in the profile of morbidity is perceived for physicians of agricultural areas;now reproductive disorders seem to prevail. The objective of this study is to determine concurrence of glyphosate exposure and reproductive disorders in a typical argentine agricultural town (Monte Maíz). An ecological study was developed with an environmental analysis of pollution sources including measurements of glyphosate and other pesticides and a cross-sectional study of spontaneous abortions and congenital abnormalities prevalence. Glyphosate was detected in soil and grain dust and was found to be at an even higher concentration in the village soil than in the rural area;650 tonnes of glyphosate are used annually in the region and manipulated inner town contaminating the soil and dust in suspension of the town creating an burden of environmental exposure to glyphosate of 79 kg per person per year. We do not find other relevant sources of pollution. The spontaneous abortion and congenital abnormalities rates are three and two times higher than the national average reported by the national health (10% vs. 3% and 3% - 4.3% vs 1.4% respectively). Our study verified high environmental exposure to glyphosate in association with increased frequencies of reproductive disorders (spontaneous abortion and congenital abnormalities) in argentine agricultural village, but is unable to make assertions cause-effect. Further studies are required with designs for such purposes.

Solution of Partial Derivative Equations of Poisson and Klein-Gordon with Neumann Conditions as a Generalized Problem of Two-Dimensional Moments

It will be shown that finding solutions from the Poisson and Klein-Gordon equations under Neumann conditions are equivalent to solving an integral equation, which can be treated as a generalized two-dimensional moment problem over a domain that is considered rectangular. The method consists to solve the integral equation numerically using the two-dimensional inverse moments problem techniques. We illustrate the different cases with examples.