This study explores the thin-layer convective solar drying of Marrubium vulgare L.leaves under conditions typical of sun-rich semi-arid climates.Drying experiments were conducted at three inlet-air temperatures(40℃,5...This study explores the thin-layer convective solar drying of Marrubium vulgare L.leaves under conditions typical of sun-rich semi-arid climates.Drying experiments were conducted at three inlet-air temperatures(40℃,50℃,60℃)and two air velocities(1.5 and 2.5 m·s^(-1))using an indirect solar dryer with auxiliary temperature control.Moisture-ratio data were fitted with eight widely used thin-layer models and evaluated using correlation coefficient(r),root-mean-square error(RMSE),and Akaike information criterion(AIC).A complementary heattransfer analysis based on Reynolds and Prandtl numbers with appropriate Nusselt correlations was used to relate flow regime to drying performance,and an energy balance quantified the relative contributions of solar and auxiliary heat.The logarithmic model consistently achieved the lowest RMSE/AIC with r>0.99 across all conditions.Higher temperature and air velocity significantly reduced drying time during the decreasing-rate period,with no constantrate stage observed.On average,solar input supplied the large majority of the thermal demand,while the auxiliary heater compensated short irradiance drops to maintain setpoints.These findings provide a reproducible dataset and a modelling benchmark for M.vulgare leaves,and they support energy-aware design of hybrid solar dryers formedicinal plants in sun-rich regions.展开更多
The aim of this study is to design,build,and evaluate an indirect forced convection solar dryer adapted to semi-arid climate,such as that of Bechar situated in the west south region of Algeria.The tested drying system...The aim of this study is to design,build,and evaluate an indirect forced convection solar dryer adapted to semi-arid climate,such as that of Bechar situated in the west south region of Algeria.The tested drying system consists of a flat-plate solar collector,an insulated two-chamber drying unit,and an Arduino-controlled device that ensures uniformtemperature distribution and real-timemonitoring using DHT22 sensors.Drying testswere conducted on locally grown beet slices at air temperatures of 45℃,60℃,and 80℃,with a constant air velocity of 1.2 m/s and a mass flow rate of 0.0027 kg/s.The collector reached a maximum temperature of 65℃,with thermal efficiencies ranging from 20%to 35%.In these conditions,the drying times were cut down to 200–300 min,and the beet’s moisture content dropped to 0.47,0.27,and 0.24 g/g dry matter,respectively.The experimental data were fitted to several empirical models,including the logarithmic model.The modelled results showed strong agreement with the experimental ones(correlation coefficients r=0.9919–0.9989;standard errors SE=0.017–0.043;root-mean-square errors RMSE=0.016–0.027).The results demonstrate that the system operates efficiently and consistently,making it suitable for the sustainable drying of agricultural and medicinal products in arid climates.展开更多
Located in Southeastern Chad. The Iro lake offers a great opportunity for the study of Precambrian formations and their Phanerozoic cover. Pluton is a Cal-alkaline granite. Due to its geographical location and geologi...Located in Southeastern Chad. The Iro lake offers a great opportunity for the study of Precambrian formations and their Phanerozoic cover. Pluton is a Cal-alkaline granite. Due to its geographical location and geological features, it holds crucial information for understanding the evolution of the Saharan Meta craton (central Africa), which remains poorly studied. One of the objectives is to map the formations Precambrian age in Southeastern Chad. Based on the petrographic and geochemical results, we identified granitoids of pan-African age (biotite granite, aplite granite and pegmatite granite). This Precambrian basement is covered with sedimentary formations (clays, argillites, lateritic cuirasses, etc.). The mineral assemblage is characteristic of acid rocks. Geochemistry reveals rocks with a high SiO2 range (62% - 77%) giving sub-alkaline to calc-alkaline acid rocks with high k (4.62% to 6.39%). The granitoids are classified as S-type hyperaluminous granites. This classification is supported by the presence of peraluminous minerals (e.g., muscovite) within the Iro granitoids, which also have high (>1%). Geochemical variation within the granites is largely due to extensive crystal fractionation. The Pattern of REEs normalized to the primitive mantle shows a pronounced negative Eu anomaly, reflecting the crystallization process and fractional crystallization of plagioclase in the rock, and a positive Yb anomaly. The role of plagioclase fractionation was relatively major during the earlier intrusive stages (consistent with the presence of Eu anomalies) and slightly increased, together with biotite and K-feldspar fractionation, during the later (granitic) rock crystallization. The Pattern of the spider normalized to MORBs shows two pronounced negative anomalies in TiO2 and Cs and a slight negative anomaly in Ba. The loss of Ba, Ti and Cs may be caused by the plagioclase fractionation, apatite and ilmenite crystal. The Ba anomaly is also controlled by the presence of K-feldspar and mica. The observed Ti anomalies are due to the fractionation of magnetite indicating a subduction environment (or remelting of a source from a subduction environment).展开更多
The prosthesis is an artificial device that can replace an organ of a human body member to restore a compromised function. It is necessary following the removal of a human organ, which can occur as a result of an illn...The prosthesis is an artificial device that can replace an organ of a human body member to restore a compromised function. It is necessary following the removal of a human organ, which can occur as a result of an illness, trauma or congenital malformation. The trans-tibia prosthesis, in particular, allows the amputee patient to recover the impaired function and regain autonomy, while facilitating their daily social integration. The trans-tibia prosthesis consists of a socket, a sleeve, connecting elements and a prosthetic foot. Each of these components plays a very important role. Among these components, the prosthetic foot usually called “SACH foot” is very often replaced due to cracking and therefore has a fairly short lifespan. At the Center for Equipment and Rehabilitation of Kabalaye (CERK), the SACH foot made using polyurethane and wood is imported and is given to patients with reduced mobility. The aim of this article is twofold, on the one hand, to make a social and pathological study of trans-tibia amputees in relation to the use of the SACH foot prosthesis, on the other hand, to compare this foot with a new prosthetic foot proposed and which is manufactured using extruded polystyrene. The result of prosthetic tests carried out on twenty-four amputees showed that the foot manufactured using extruded polystyrene is better in terms of resistance, bulk and adaptability to active amputees.展开更多
This study focuses on the thermophysical characterizations of composite materials made from polypropylene reinforced with residues and fibers from Borassus wood from Chad. These properties are experimentally determine...This study focuses on the thermophysical characterizations of composite materials made from polypropylene reinforced with residues and fibers from Borassus wood from Chad. These properties are experimentally determined at different temperatures using the hot wire method of the “FP2C” machine, where the hot wire probe is inserted between two specimens. The values of the thermal conductivity in powdered Borassus wood range from 0.170 W/mK to 0.182 W/mK for female wood (FNTF) and from 0.169 W/mK to 0.173 W/mK for male wood. For the female and male fibers, the thermal conductivity values range from 0.137 W/mK to 0.157 W/mK for the female and from 0.138 W/mK to 0.168 W/mK for the male. The thermal effusivity of the residues and fibers of Borassus wood varies from: 509.6 Ws1/2/m2K to 543 Ws1/2/m2K for the powder of female wood and from 524.6 Ws1/2/m2K to 547 Ws1/2/m2K for the powder of male wood. For the fibers of Borassus wood, the values range from 410.6 Ws1/2/m2K to 523.6 Ws1/2/m2K for the female wood fibers and from 420.3 Ws1/2/m2K to 480.3 Ws1/2/m2K for the male wood fibers. These results are important for the applications of Borassus wood residues and fibers in construction works regarding the thermal insulation of habitats.展开更多
The authors regret that the declaration of Acknowledgement as below is missing in the paper:AcknowledgementWe are grateful to the Department of Biology and Postgraduate Sciences-Biology of the Universidad del Valle,Ca...The authors regret that the declaration of Acknowledgement as below is missing in the paper:AcknowledgementWe are grateful to the Department of Biology and Postgraduate Sciences-Biology of the Universidad del Valle,Cali-Colombia for their support of the project;to Wilmar Torres MSc.for his statistical advice;to the biologist Helen Burnham MSc.for the translation of the document;to Isabel Castro and all the members of the Ornithology and Animal Behaviour Laboratory-OYCA of Universidad del Valle for their invaluable support in the field.We sincerely thank the anonymous re-viewers for their invaluable feedback and contributions to our manuscript.展开更多
A total of fifty (50) samples of water from Lake Fitri (Chad), with 25 samples per island (Domoro and Maguite). The aim of this study was to analyze the bacteriological, biochemical and physico-chemical quality of the...A total of fifty (50) samples of water from Lake Fitri (Chad), with 25 samples per island (Domoro and Maguite). The aim of this study was to analyze the bacteriological, biochemical and physico-chemical quality of the water in Lake Fitri in Chad. Standard microbiology methods were used. Isolated strains of enterobacteria were characterized by API 20E and API Staph galleries and confirmed by API Web. Antibiotic resistance was performed according to the recommendations of the antibiogram committee (CA-SFM, 2019). Physico-chemical analysis of the water was carried out by (Rodier, 2009). The microbiological results revealed an abundance on the Domoro islands (5.37.106 ± 1.5.105 and 1.97.105 ± 4.94.104), successively for total aerobic mesophilic flora (FMAT), and thermotolerant coliform (E. coli) and on the Maguite Islands (4.71.106 ± 7.14.105 and 2.32.105 ± 2.86.104), alternately for total aerobic mesophilic flora (FMAT), and thermotolerant coliform (E. coli). The results obtained after incubation of the biochemical tests using the API 20E and API Staph galleries and their proposed numerical profile analyzed using Api software and confirmed by Api Web confirmed the contamination of the waters of Lake Fitri by pathogenic strains of E. coli, Staphylococcus and Salmonella spp. The results of the antibiogram carried out show the emergence of certain resistances to Tobramycin, Flucytosine and Teicoplanin. The average levels of BOD5, COD, SS, Nitrate (NO3) and Nitrite (NO2) for Domoro Island were 32.14 ± 2.37 mg/L, 423.86 ± 4.78 mg/L, 65.42 ± 2.27 mg/L, 0.04 ± 0.01 mg/L and 3.32 ± 1.48 mg/L respectively. The water from the islands of Lake Fitri must therefore be rigorously treated before consumption.展开更多
Carotenoid-based plumage coloration may signal individuals' overall body condition, influencing reproduction and survival of birds. In tropical species, little is known about the influence of color on social inter...Carotenoid-based plumage coloration may signal individuals' overall body condition, influencing reproduction and survival of birds. In tropical species, little is known about the influence of color on social interactions and mate attraction. We evaluated the chromatic variation of 136 adult Saffron Finches(Sicalis ffiaveola) in Cali and Jamundí, Colombia. Our aim was to determine whether plumage coloration in this social, abundant, and widely distributed species is a signal used in mate choice and establishment of hierarchies. We predicted that there was intrasexual chromatic variation in crown and throat, and that individuals with higher saturation, regardless of sex, would be preferred by opposite sex and they would be dominant in intrasexual aggressive interactions, reflecting better condition. We quantified the reflectance of the crown and throat with visible and ultraviolet light(300–700 nm) subsequent to the molecular sex determination of each individual. Our results suggest that the chromatic variation in the crown and throat is explained by the perception of medium and long wavelengths in both sexes. Additionally, saturation is the color characteristic that best explains the chromatic variation. We formed duos of individuals based on chromatic contrast and conducted 23 mate choice experiments and 21 dominance experiments. The analysis of spectra and experiments revealed that dominance in males was associated with less saturated crowns. Our results reveal that in the Saffron Finches the “negatively correlated handicap” is a plausible hypothesis. Crown color appears to mediate dominance interactions, with less saturated males potentially taking greater risks to gain access to resources.展开更多
The Rössler attractor model is an important model that provides valuable insights into the behavior of chaotic systems in real life and is applicable in understanding weather patterns,biological systems,and secur...The Rössler attractor model is an important model that provides valuable insights into the behavior of chaotic systems in real life and is applicable in understanding weather patterns,biological systems,and secure communications.So,this work aims to present the numerical performances of the nonlinear fractional Rössler attractor system under Caputo derivatives by designing the numerical framework based on Ultraspherical wavelets.The Caputo fractional Rössler attractor model is simulated into two categories,(i)Asymmetric and(ii)Symmetric.The Ultraspherical wavelets basis with suitable collocation grids is implemented for comprehensive error analysis in the solutions of the Caputo fractional Rössler attractor model,depicting each computation in graphs and tables to analyze how fractional order affects the model’s dynamics.Approximate solutions obtained through the proposed scheme for integer order are well comparable with the fourth-order Runge-Kutta method.Also,the stability analyses of the considered model are discussed for different equilibrium points.Various fractional orders are considered while performing numerical simulations for the Caputo fractional Rössler attractor model by using Mathematica.The suggested approach can solve another non-linear fractional model due to its straightforward implementation.展开更多
Essential oils(EOs)derived from medicinal plants are gaining recognition as sustainable alternatives to synthetic fungicides in the management of plant pathogens.This study investigates the chemical composition,chroma...Essential oils(EOs)derived from medicinal plants are gaining recognition as sustainable alternatives to synthetic fungicides in the management of plant pathogens.This study investigates the chemical composition,chromatographic profile,and antifungal of Mentha rotundifolia essential oil against Fusarium oxysporum f.sp.albedinis(Foa),the pathogen responsible for Bayoud disease in date palm.The oil was extracted through hydrodistillation and characterized using thin-layer chromatography(TLC)and gas chromatography–mass spectrometry(GC-MS),revealing multiple fractions corresponding to terpenoid constituents and 23 chemical constituents,predominantly oxygenated monoterpenes(68.51%),with piperitenone oxide as the major component(62.53%).The antifungal efficacy was evaluated against ten(10)isolates of F.o.a across seven(07)concentrations different concentrations.(0;0.25;0.5;0.75;1;1.25;1.5μL/mL).The results obtained show a progressive decrease in the diameters of the colonies of F.o.a isolates by increasing the doses of EOMR.The percentage of inhibition varies from 7.82 to 83.41%;However,the dose of 1.75μL/mL showed 100%inhibition for all F.o.a isolates tested.These outcomes demonstrate the potential of M.rotundifolia essential oil as a natural,environmentally friendly antifungal agent,supporting its application in sustainable management strategies for Bayoud disease in date palm.展开更多
Laser-induced graphene(LIG)has emerged as a versatile,sustainable material for advanced energy technologies,offering a scalable,catalyst-free,and programmable method to directly convert carbon-rich substrates into por...Laser-induced graphene(LIG)has emerged as a versatile,sustainable material for advanced energy technologies,offering a scalable,catalyst-free,and programmable method to directly convert carbon-rich substrates into porous,conductive graphene.This single-step laser writing approach enables flexible,patternable electrodes without complex post-processing.With its high conductivity,large surface area,and tunable chemistry,LIG is well-suited for diverse applications including batteries,supercapacitors,dyesensitized solar cells(DSSCs),dual cells,water-splitting electrocatalysis,and triboelectric nanogenerators(TENGs).In energy storage,LIG improves charge transport,buffer volume changes,and provides a robust framework,enhancing capacitance,cycling stability,and rate capability.Its catalytic activity is further boosted through heteroatom doping or transition-metal incorporation,achieving HER/OER performance comparable to noble metals.In DSSCs,LIG functions as a flexible,low-cost alternative to platinum counter electrodes,while in TENGs,its strong triboelectric response and mechanical durability enable integration into self-powered,wearable systems.Despite the immense recent progress in this field,challenges remain regarding the scalability,long-term operational stability,and interfacial engineering of LIGbased composites.Further exploration into multi-laser systems,substrate diversity,and synergistic composite architectures will be crucial to optimizing device performance and reliability.Nevertheless,the green,cost-efficient,rapid,and programmable synthesis of LIG poses it as a cornerstone potential building block material in the development of future sustainable and multifunctional energy systems.Throughout the review we compare fabrication strategies,summarize performance metrics against relevant benchmarks,and identifying common mechanistic advantages conferred by the laser writing process.Remaining challenges-such as scale-up,precursor diversity,long-term environmental stability,and integration into complex device architectures-are outlined alongside prospective research directions.Collectively,this review article provides an in-depth perspective on the multifunctional nature of LIG,underscoring its promise in next-generation energy storage,conversion,harvesting applications,and laying the groundwork for future research directions.展开更多
Magnetic Resonance Imaging(MRI)has a pivotal role in medical image analysis,for its ability in supporting disease detection and diagnosis.Fuzzy C-Means(FCM)clustering is widely used for MRI segmentation due to its abi...Magnetic Resonance Imaging(MRI)has a pivotal role in medical image analysis,for its ability in supporting disease detection and diagnosis.Fuzzy C-Means(FCM)clustering is widely used for MRI segmentation due to its ability to handle image uncertainty.However,the latter still has countless limitations,including sensitivity to initialization,susceptibility to local optima,and high computational cost.To address these limitations,this study integrates Grey Wolf Optimization(GWO)with FCM to enhance cluster center selection,improving segmentation accuracy and robustness.Moreover,to further refine optimization,Fuzzy Entropy Clustering was utilized for its distinctive features from other traditional objective functions.Fuzzy entropy effectively quantifies uncertainty,leading to more well-defined clusters,improved noise robustness,and better preservation of anatomical structures in MRI images.Despite these advantages,the iterative nature of GWO and FCM introduces significant computational overhead,which restricts their applicability to high-resolution medical images.To overcome this bottleneck,we propose a Parallelized-GWO-based FCM(P-GWO-FCM)approach using GPU acceleration,where both GWO optimization and FCM updates(centroid computation and membership matrix updates)are parallelized.By concurrently executing these processes,our approach efficiently distributes the computational workload,significantly reducing execution time while maintaining high segmentation accuracy.The proposed parallel method,P-GWO-FCM,was evaluated on both simulated and clinical brain MR images,focusing on segmenting white matter,gray matter,and cerebrospinal fluid regions.The results indicate significant improvements in segmentation accuracy,achieving a Jaccard Similarity(JS)of 0.92,a Partition Coefficient Index(PCI)of 0.91,a Partition Entropy Index(PEI)of 0.25,and a Davies-Bouldin Index(DBI)of 0.30.Experimental comparisons demonstrate that P-GWO-FCM outperforms existing methods in both segmentation accuracy and computational efficiency,making it a promising solution for real-time medical image segmentation.展开更多
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）.Thr...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.展开更多
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...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.展开更多
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 af...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.展开更多
In this paper we prove that the maximal operator I of dyadic derivative is not bounded from the Hardy space H p [0, 1] to the Hardy space H p [0, 1], when 0 〈 p ≤ 1.
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% ...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.展开更多
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 biodivers...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.展开更多
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 ...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°C - 60°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°C for 180 min;total flavonoids (79.52 ± 0.55 mg catechin equivalent/g dry weigh) with 80% aqueous methanol at 20°C for 450 min, and condensed tannins (28.15 ± 0.80 mg catechin equivalent/g dry weigh) with 60% aqueous acetone at 50°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.展开更多
Streptococcus agalactiae (GBS) is considered as the most important cause of invasive bacterial disease in infants. There are few current data from serotype IX of GBS worldwide. The present work has been done in order ...Streptococcus agalactiae (GBS) is considered as the most important cause of invasive bacterial disease in infants. There are few current data from serotype IX of GBS worldwide. The present work has been done in order to make a contribution to the knowledge of serotype IX through phenotypic and genotypic study of virulence and resistance. Of 200 strains tested, 5.5% were serotype IX and all were colonizing. In 63.6% of the strains the presence of the bac, bca and hylB genes was determined, and in 54.5% of lmb and rib. All strains were susceptible to Clindamycin and Erythromycin however five isolates showed the resistance genes: ermB, ermTR and/or mefA. The presence of serotype IX in Misiones, a province situated in the northeaster of Argentina, which limits with Paraguay and Brazil in South America, gives the region a particular situation. Currently, public health efforts are aimed at prevention and treatment, study of the virulence mechanisms, surveillance of resistance to antibiotics and the development of effective vaccines to prevent GBS infection.展开更多
文摘This study explores the thin-layer convective solar drying of Marrubium vulgare L.leaves under conditions typical of sun-rich semi-arid climates.Drying experiments were conducted at three inlet-air temperatures(40℃,50℃,60℃)and two air velocities(1.5 and 2.5 m·s^(-1))using an indirect solar dryer with auxiliary temperature control.Moisture-ratio data were fitted with eight widely used thin-layer models and evaluated using correlation coefficient(r),root-mean-square error(RMSE),and Akaike information criterion(AIC).A complementary heattransfer analysis based on Reynolds and Prandtl numbers with appropriate Nusselt correlations was used to relate flow regime to drying performance,and an energy balance quantified the relative contributions of solar and auxiliary heat.The logarithmic model consistently achieved the lowest RMSE/AIC with r>0.99 across all conditions.Higher temperature and air velocity significantly reduced drying time during the decreasing-rate period,with no constantrate stage observed.On average,solar input supplied the large majority of the thermal demand,while the auxiliary heater compensated short irradiance drops to maintain setpoints.These findings provide a reproducible dataset and a modelling benchmark for M.vulgare leaves,and they support energy-aware design of hybrid solar dryers formedicinal plants in sun-rich regions.
文摘The aim of this study is to design,build,and evaluate an indirect forced convection solar dryer adapted to semi-arid climate,such as that of Bechar situated in the west south region of Algeria.The tested drying system consists of a flat-plate solar collector,an insulated two-chamber drying unit,and an Arduino-controlled device that ensures uniformtemperature distribution and real-timemonitoring using DHT22 sensors.Drying testswere conducted on locally grown beet slices at air temperatures of 45℃,60℃,and 80℃,with a constant air velocity of 1.2 m/s and a mass flow rate of 0.0027 kg/s.The collector reached a maximum temperature of 65℃,with thermal efficiencies ranging from 20%to 35%.In these conditions,the drying times were cut down to 200–300 min,and the beet’s moisture content dropped to 0.47,0.27,and 0.24 g/g dry matter,respectively.The experimental data were fitted to several empirical models,including the logarithmic model.The modelled results showed strong agreement with the experimental ones(correlation coefficients r=0.9919–0.9989;standard errors SE=0.017–0.043;root-mean-square errors RMSE=0.016–0.027).The results demonstrate that the system operates efficiently and consistently,making it suitable for the sustainable drying of agricultural and medicinal products in arid climates.
文摘Located in Southeastern Chad. The Iro lake offers a great opportunity for the study of Precambrian formations and their Phanerozoic cover. Pluton is a Cal-alkaline granite. Due to its geographical location and geological features, it holds crucial information for understanding the evolution of the Saharan Meta craton (central Africa), which remains poorly studied. One of the objectives is to map the formations Precambrian age in Southeastern Chad. Based on the petrographic and geochemical results, we identified granitoids of pan-African age (biotite granite, aplite granite and pegmatite granite). This Precambrian basement is covered with sedimentary formations (clays, argillites, lateritic cuirasses, etc.). The mineral assemblage is characteristic of acid rocks. Geochemistry reveals rocks with a high SiO2 range (62% - 77%) giving sub-alkaline to calc-alkaline acid rocks with high k (4.62% to 6.39%). The granitoids are classified as S-type hyperaluminous granites. This classification is supported by the presence of peraluminous minerals (e.g., muscovite) within the Iro granitoids, which also have high (>1%). Geochemical variation within the granites is largely due to extensive crystal fractionation. The Pattern of REEs normalized to the primitive mantle shows a pronounced negative Eu anomaly, reflecting the crystallization process and fractional crystallization of plagioclase in the rock, and a positive Yb anomaly. The role of plagioclase fractionation was relatively major during the earlier intrusive stages (consistent with the presence of Eu anomalies) and slightly increased, together with biotite and K-feldspar fractionation, during the later (granitic) rock crystallization. The Pattern of the spider normalized to MORBs shows two pronounced negative anomalies in TiO2 and Cs and a slight negative anomaly in Ba. The loss of Ba, Ti and Cs may be caused by the plagioclase fractionation, apatite and ilmenite crystal. The Ba anomaly is also controlled by the presence of K-feldspar and mica. The observed Ti anomalies are due to the fractionation of magnetite indicating a subduction environment (or remelting of a source from a subduction environment).
文摘The prosthesis is an artificial device that can replace an organ of a human body member to restore a compromised function. It is necessary following the removal of a human organ, which can occur as a result of an illness, trauma or congenital malformation. The trans-tibia prosthesis, in particular, allows the amputee patient to recover the impaired function and regain autonomy, while facilitating their daily social integration. The trans-tibia prosthesis consists of a socket, a sleeve, connecting elements and a prosthetic foot. Each of these components plays a very important role. Among these components, the prosthetic foot usually called “SACH foot” is very often replaced due to cracking and therefore has a fairly short lifespan. At the Center for Equipment and Rehabilitation of Kabalaye (CERK), the SACH foot made using polyurethane and wood is imported and is given to patients with reduced mobility. The aim of this article is twofold, on the one hand, to make a social and pathological study of trans-tibia amputees in relation to the use of the SACH foot prosthesis, on the other hand, to compare this foot with a new prosthetic foot proposed and which is manufactured using extruded polystyrene. The result of prosthetic tests carried out on twenty-four amputees showed that the foot manufactured using extruded polystyrene is better in terms of resistance, bulk and adaptability to active amputees.
文摘This study focuses on the thermophysical characterizations of composite materials made from polypropylene reinforced with residues and fibers from Borassus wood from Chad. These properties are experimentally determined at different temperatures using the hot wire method of the “FP2C” machine, where the hot wire probe is inserted between two specimens. The values of the thermal conductivity in powdered Borassus wood range from 0.170 W/mK to 0.182 W/mK for female wood (FNTF) and from 0.169 W/mK to 0.173 W/mK for male wood. For the female and male fibers, the thermal conductivity values range from 0.137 W/mK to 0.157 W/mK for the female and from 0.138 W/mK to 0.168 W/mK for the male. The thermal effusivity of the residues and fibers of Borassus wood varies from: 509.6 Ws1/2/m2K to 543 Ws1/2/m2K for the powder of female wood and from 524.6 Ws1/2/m2K to 547 Ws1/2/m2K for the powder of male wood. For the fibers of Borassus wood, the values range from 410.6 Ws1/2/m2K to 523.6 Ws1/2/m2K for the female wood fibers and from 420.3 Ws1/2/m2K to 480.3 Ws1/2/m2K for the male wood fibers. These results are important for the applications of Borassus wood residues and fibers in construction works regarding the thermal insulation of habitats.
文摘The authors regret that the declaration of Acknowledgement as below is missing in the paper:AcknowledgementWe are grateful to the Department of Biology and Postgraduate Sciences-Biology of the Universidad del Valle,Cali-Colombia for their support of the project;to Wilmar Torres MSc.for his statistical advice;to the biologist Helen Burnham MSc.for the translation of the document;to Isabel Castro and all the members of the Ornithology and Animal Behaviour Laboratory-OYCA of Universidad del Valle for their invaluable support in the field.We sincerely thank the anonymous re-viewers for their invaluable feedback and contributions to our manuscript.
文摘A total of fifty (50) samples of water from Lake Fitri (Chad), with 25 samples per island (Domoro and Maguite). The aim of this study was to analyze the bacteriological, biochemical and physico-chemical quality of the water in Lake Fitri in Chad. Standard microbiology methods were used. Isolated strains of enterobacteria were characterized by API 20E and API Staph galleries and confirmed by API Web. Antibiotic resistance was performed according to the recommendations of the antibiogram committee (CA-SFM, 2019). Physico-chemical analysis of the water was carried out by (Rodier, 2009). The microbiological results revealed an abundance on the Domoro islands (5.37.106 ± 1.5.105 and 1.97.105 ± 4.94.104), successively for total aerobic mesophilic flora (FMAT), and thermotolerant coliform (E. coli) and on the Maguite Islands (4.71.106 ± 7.14.105 and 2.32.105 ± 2.86.104), alternately for total aerobic mesophilic flora (FMAT), and thermotolerant coliform (E. coli). The results obtained after incubation of the biochemical tests using the API 20E and API Staph galleries and their proposed numerical profile analyzed using Api software and confirmed by Api Web confirmed the contamination of the waters of Lake Fitri by pathogenic strains of E. coli, Staphylococcus and Salmonella spp. The results of the antibiogram carried out show the emergence of certain resistances to Tobramycin, Flucytosine and Teicoplanin. The average levels of BOD5, COD, SS, Nitrate (NO3) and Nitrite (NO2) for Domoro Island were 32.14 ± 2.37 mg/L, 423.86 ± 4.78 mg/L, 65.42 ± 2.27 mg/L, 0.04 ± 0.01 mg/L and 3.32 ± 1.48 mg/L respectively. The water from the islands of Lake Fitri must therefore be rigorously treated before consumption.
基金supported by the Universidad del Valle (Award Number:Research Vice-Rectory Grant:4-2016)。
文摘Carotenoid-based plumage coloration may signal individuals' overall body condition, influencing reproduction and survival of birds. In tropical species, little is known about the influence of color on social interactions and mate attraction. We evaluated the chromatic variation of 136 adult Saffron Finches(Sicalis ffiaveola) in Cali and Jamundí, Colombia. Our aim was to determine whether plumage coloration in this social, abundant, and widely distributed species is a signal used in mate choice and establishment of hierarchies. We predicted that there was intrasexual chromatic variation in crown and throat, and that individuals with higher saturation, regardless of sex, would be preferred by opposite sex and they would be dominant in intrasexual aggressive interactions, reflecting better condition. We quantified the reflectance of the crown and throat with visible and ultraviolet light(300–700 nm) subsequent to the molecular sex determination of each individual. Our results suggest that the chromatic variation in the crown and throat is explained by the perception of medium and long wavelengths in both sexes. Additionally, saturation is the color characteristic that best explains the chromatic variation. We formed duos of individuals based on chromatic contrast and conducted 23 mate choice experiments and 21 dominance experiments. The analysis of spectra and experiments revealed that dominance in males was associated with less saturated crowns. Our results reveal that in the Saffron Finches the “negatively correlated handicap” is a plausible hypothesis. Crown color appears to mediate dominance interactions, with less saturated males potentially taking greater risks to gain access to resources.
基金"La derivada fraccional generalizada,nuevos resultados y aplicaciones a desigualdades integrales"Cod UIO-077-2024supported via funding from Prince Sattam bin Abdulaziz University project number(PSAU/2025/R/1446).
文摘The Rössler attractor model is an important model that provides valuable insights into the behavior of chaotic systems in real life and is applicable in understanding weather patterns,biological systems,and secure communications.So,this work aims to present the numerical performances of the nonlinear fractional Rössler attractor system under Caputo derivatives by designing the numerical framework based on Ultraspherical wavelets.The Caputo fractional Rössler attractor model is simulated into two categories,(i)Asymmetric and(ii)Symmetric.The Ultraspherical wavelets basis with suitable collocation grids is implemented for comprehensive error analysis in the solutions of the Caputo fractional Rössler attractor model,depicting each computation in graphs and tables to analyze how fractional order affects the model’s dynamics.Approximate solutions obtained through the proposed scheme for integer order are well comparable with the fourth-order Runge-Kutta method.Also,the stability analyses of the considered model are discussed for different equilibrium points.Various fractional orders are considered while performing numerical simulations for the Caputo fractional Rössler attractor model by using Mathematica.The suggested approach can solve another non-linear fractional model due to its straightforward implementation.
文摘Essential oils(EOs)derived from medicinal plants are gaining recognition as sustainable alternatives to synthetic fungicides in the management of plant pathogens.This study investigates the chemical composition,chromatographic profile,and antifungal of Mentha rotundifolia essential oil against Fusarium oxysporum f.sp.albedinis(Foa),the pathogen responsible for Bayoud disease in date palm.The oil was extracted through hydrodistillation and characterized using thin-layer chromatography(TLC)and gas chromatography–mass spectrometry(GC-MS),revealing multiple fractions corresponding to terpenoid constituents and 23 chemical constituents,predominantly oxygenated monoterpenes(68.51%),with piperitenone oxide as the major component(62.53%).The antifungal efficacy was evaluated against ten(10)isolates of F.o.a across seven(07)concentrations different concentrations.(0;0.25;0.5;0.75;1;1.25;1.5μL/mL).The results obtained show a progressive decrease in the diameters of the colonies of F.o.a isolates by increasing the doses of EOMR.The percentage of inhibition varies from 7.82 to 83.41%;However,the dose of 1.75μL/mL showed 100%inhibition for all F.o.a isolates tested.These outcomes demonstrate the potential of M.rotundifolia essential oil as a natural,environmentally friendly antifungal agent,supporting its application in sustainable management strategies for Bayoud disease in date palm.
文摘Laser-induced graphene(LIG)has emerged as a versatile,sustainable material for advanced energy technologies,offering a scalable,catalyst-free,and programmable method to directly convert carbon-rich substrates into porous,conductive graphene.This single-step laser writing approach enables flexible,patternable electrodes without complex post-processing.With its high conductivity,large surface area,and tunable chemistry,LIG is well-suited for diverse applications including batteries,supercapacitors,dyesensitized solar cells(DSSCs),dual cells,water-splitting electrocatalysis,and triboelectric nanogenerators(TENGs).In energy storage,LIG improves charge transport,buffer volume changes,and provides a robust framework,enhancing capacitance,cycling stability,and rate capability.Its catalytic activity is further boosted through heteroatom doping or transition-metal incorporation,achieving HER/OER performance comparable to noble metals.In DSSCs,LIG functions as a flexible,low-cost alternative to platinum counter electrodes,while in TENGs,its strong triboelectric response and mechanical durability enable integration into self-powered,wearable systems.Despite the immense recent progress in this field,challenges remain regarding the scalability,long-term operational stability,and interfacial engineering of LIGbased composites.Further exploration into multi-laser systems,substrate diversity,and synergistic composite architectures will be crucial to optimizing device performance and reliability.Nevertheless,the green,cost-efficient,rapid,and programmable synthesis of LIG poses it as a cornerstone potential building block material in the development of future sustainable and multifunctional energy systems.Throughout the review we compare fabrication strategies,summarize performance metrics against relevant benchmarks,and identifying common mechanistic advantages conferred by the laser writing process.Remaining challenges-such as scale-up,precursor diversity,long-term environmental stability,and integration into complex device architectures-are outlined alongside prospective research directions.Collectively,this review article provides an in-depth perspective on the multifunctional nature of LIG,underscoring its promise in next-generation energy storage,conversion,harvesting applications,and laying the groundwork for future research directions.
文摘Magnetic Resonance Imaging(MRI)has a pivotal role in medical image analysis,for its ability in supporting disease detection and diagnosis.Fuzzy C-Means(FCM)clustering is widely used for MRI segmentation due to its ability to handle image uncertainty.However,the latter still has countless limitations,including sensitivity to initialization,susceptibility to local optima,and high computational cost.To address these limitations,this study integrates Grey Wolf Optimization(GWO)with FCM to enhance cluster center selection,improving segmentation accuracy and robustness.Moreover,to further refine optimization,Fuzzy Entropy Clustering was utilized for its distinctive features from other traditional objective functions.Fuzzy entropy effectively quantifies uncertainty,leading to more well-defined clusters,improved noise robustness,and better preservation of anatomical structures in MRI images.Despite these advantages,the iterative nature of GWO and FCM introduces significant computational overhead,which restricts their applicability to high-resolution medical images.To overcome this bottleneck,we propose a Parallelized-GWO-based FCM(P-GWO-FCM)approach using GPU acceleration,where both GWO optimization and FCM updates(centroid computation and membership matrix updates)are parallelized.By concurrently executing these processes,our approach efficiently distributes the computational workload,significantly reducing execution time while maintaining high segmentation accuracy.The proposed parallel method,P-GWO-FCM,was evaluated on both simulated and clinical brain MR images,focusing on segmenting white matter,gray matter,and cerebrospinal fluid regions.The results indicate significant improvements in segmentation accuracy,achieving a Jaccard Similarity(JS)of 0.92,a Partition Coefficient Index(PCI)of 0.91,a Partition Entropy Index(PEI)of 0.25,and a Davies-Bouldin Index(DBI)of 0.30.Experimental comparisons demonstrate that P-GWO-FCM outperforms existing methods in both segmentation accuracy and computational efficiency,making it a promising solution for real-time medical image segmentation.
文摘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.
基金the Faculty of Health Sciences from the Institution University Colegio Mayor de Antioquia and the General System of Royalties from Antioquia,Colombia,for funding this projectthe National University of Colombia and the Doctoral Fellowship Program(567)from Colciencias
文摘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.
文摘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.
文摘In this paper we prove that the maximal operator I of dyadic derivative is not bounded from the Hardy space H p [0, 1] to the Hardy space H p [0, 1], when 0 〈 p ≤ 1.
文摘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.
文摘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.
文摘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°C - 60°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°C for 180 min;total flavonoids (79.52 ± 0.55 mg catechin equivalent/g dry weigh) with 80% aqueous methanol at 20°C for 450 min, and condensed tannins (28.15 ± 0.80 mg catechin equivalent/g dry weigh) with 60% aqueous acetone at 50°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.
文摘Streptococcus agalactiae (GBS) is considered as the most important cause of invasive bacterial disease in infants. There are few current data from serotype IX of GBS worldwide. The present work has been done in order to make a contribution to the knowledge of serotype IX through phenotypic and genotypic study of virulence and resistance. Of 200 strains tested, 5.5% were serotype IX and all were colonizing. In 63.6% of the strains the presence of the bac, bca and hylB genes was determined, and in 54.5% of lmb and rib. All strains were susceptible to Clindamycin and Erythromycin however five isolates showed the resistance genes: ermB, ermTR and/or mefA. The presence of serotype IX in Misiones, a province situated in the northeaster of Argentina, which limits with Paraguay and Brazil in South America, gives the region a particular situation. Currently, public health efforts are aimed at prevention and treatment, study of the virulence mechanisms, surveillance of resistance to antibiotics and the development of effective vaccines to prevent GBS infection.
