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
The ramifications of global climate change and resource scarcities have made it imperative to re-examine the definition of sustainable energy-storage systems.It is crucial to recognize that not all renewable resources...The ramifications of global climate change and resource scarcities have made it imperative to re-examine the definition of sustainable energy-storage systems.It is crucial to recognize that not all renewable resources are inherently sustainable,and their full impact on the environment must be assessed.With the proliferation of invasive jellyfish species wreaking havoc on marine ecosystems and economies worldwide,utilizing overabundant jellyfish as a carbon source presents an opportunity to create energy-storage systems that are both financially beneficial and environmentally remediating.Accordingly,a comprehensive approach to sustainability also requires eco-friendly solutions throughout the entire lifecycle,from material sourcing to battery production,without compromising highperformance requirements.Currently,most electrode syntheses for lithium-ion batteries(LIBs) employed are energy-intensive,multiple-steps,complex,and additive-heavy.In response,this work pioneers the straightforward use of low-energy laser irradiation of a jellyfish biomass/silicon nanoparticle blend to encapsulate the silicon nanoparticles in-situ within the as-forming conductive carbonized matrix,creating sustainable and additive-free composite anodes.The self-standing anode is directly synthesized under ambient conditions and requires no post-processing.Here,a laser-synthesized conductive threedimensional porous carbon/silicon composite anode from raw jellyfish biomass for LIBs is presented,displaying outstanding cyclic stability(>1000 cycles),excellent capacity retention(>50% retention after1000 cycles),exceptional coulombic efficiency(>99%),superb reversible gravimetric capacity(>2000 mAh/g),and high rate performance capability(>1.6 A/g),paving a new path to future sustainable energy production.展开更多
Recent technological advancements,such as portable electronics and electric vehicles,have created a pressing need for more efficient energy storage solutions.Lithium-ion batteries(LIBs)have been the preferred choice f...Recent technological advancements,such as portable electronics and electric vehicles,have created a pressing need for more efficient energy storage solutions.Lithium-ion batteries(LIBs)have been the preferred choice for these applications,with graphite being the standard anode material due to its stability.However,graphite falls short of meeting the growing demand for higher energy density,possessing a theoretical capacity that lags behind.To address this,researchers are actively seeking alternative materials to replace graphite in commercial batteries.One promising avenue involves lithiumalloying materials like silicon and phosphorus,which offer high theoretical capacities.Carbon-silicon composites have emerged as a viable option,showing improved capacity and performance over traditional graphite or pure silicon anodes.Yet,the existing methods for synthesizing these composites remain complex,energy-intensive,and costly,preventing widespread adoption.A groundbreaking approach is presented here:the use of a laser writing strategy to rapidly transform common organic carbon precursors and silicon blends into efficient“graphenic silicon”composite thin films.These films exhibit exceptional structural and energy storage properties.The resulting three-dimensional porous composite anodes showcase impressive attributes,including ultrahigh silicon content,remarkable cyclic stability(over 4500 cycles with∼40%retention),rapid charging rates(up to 10 A g^(-1)),substantial areal capacity(>5.1 mAh cm^(-2)),and excellent gravimetric capacity(>2400 mAh g^(-1) at 0.2 A g^(-1)).This strategy marks a significant step toward the scalable production of high-performance LIB materials.Leveraging widely available,cost-effective precursors,the laser-printed“graphenic silicon”composites demonstrate unparalleled performance,potentially streamlining anode production while maintaining exceptional capabilities.This innovation not only paves the way for advanced LIBs but also sets a precedent for transforming various materials into high-performing electrodes,promising reduced complexity and cost in battery production.展开更多
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 a...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.展开更多
The aim of the present work is to assess the value of Detarium Senegalense by determining the content of total phenols, total flavonoids and total anthocyanins, and by evaluating the free radical scavenging activity o...The aim of the present work is to assess the value of Detarium Senegalense by determining the content of total phenols, total flavonoids and total anthocyanins, and by evaluating the free radical scavenging activity of Detarium Senegalense extracts. For this purpose, sequential extraction using solvents of increasing polarity was essential. The various extracts obtained underwent phytochemical and biochemical analyses. Phytochemical screening revealed the presence of flavonoids, alkaloids, tannins, polyphenols, anthocyanins and steroids/terpenes. Quantitative analysis of total polyphenols, total flavonoids and total anthocyanins yielded the following results: total flavonoids (0.803 ± 0029 mg EQ/100g P for acetone extract of roots and 0.871 ± 0.401 mg EQ/100g P for methanol extract of leaves);total polyphenols (23.298 ± 12.68 mg EAG/100g P for acetone extract of roots and 24.69 ± 0.49 401 mg EAG/100g P for methanol extract of leaves);total monomeric anthocyanins (44.697 ± 0.939 mg EC3G/100g P and 16.699 ± 0.193 mg EC3G/100g P respectively for acetone and methanol extracts of stem bark). DPPH free radical scavenging activity was 1.674 ± 0.023 mg/mL for the acetone extract and 0.934 ± 0.24 mg/mL for the methanol extract of roots. .展开更多
In this article, we study generating sets of the complete semigroups of binary relations defined by X-semilattices of unions of the class Σ<sub>8</sub>(X, 5). Found uniquely irreducible generating set for...In this article, we study generating sets of the complete semigroups of binary relations defined by X-semilattices of unions of the class Σ<sub>8</sub>(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.展开更多
The use of medicinal plants occupies an important place in traditional Chadian medicine, this study was carried out with the aim of listing the medicinal plants sold in the markets of the city of N’Djamena, and knowl...The use of medicinal plants occupies an important place in traditional Chadian medicine, this study was carried out with the aim of listing the medicinal plants sold in the markets of the city of N’Djamena, and knowledge of the medicinal flora Chad, such as the leaves of Guiera senegalensis in Arabic called Khibeche, the roots of Cassia occidentalis called Am kwala-Kinkéliba in Arabic;the bark of Khaya senegalensis (Desv) A. Juss called Muraї in Arabic and the seeds of Trigonella foenum-graecum called Helbé in Arabic in order to treat the most frequently cited diseases such as malaria, the common cold, mother and newborn care, and typhoid. Ethnobotanical surveys were conducted from September to December 2022, in three markets in the city of N’Djamena, based on individual interviews using a semi-structured questionnaire, with 30 herbalists and traditional practitioners. Phytochemical screening analyses of the organs of four plants were carried out in the chemistry and biology laboratory of the Faculty of Exact and Applied Sciences (FSEA) following a standard protocol established by [1] and slightly modified by [2] [3]. The results of the surveys identified 68 species divided into fifty-five (55) genera and twenty-seven (27) families, the most represented of which were Caesalpiniaceae (10 species), Mimosaceae (5 species) and Combretaceae (4 species). The leaves were the most commonly used parts (43%), with decoction (70%) the most frequently used method of preparation. The oral route was the most popular with 73% of recipes. The phytochemical study revealed a wealth of secondary metabolites such as Trapezoidal Sterols, Alkaloids, Tannins, Flavonoids, Free Quinones, Anthocyane, Anthraquinones, Saponosides and Heterosides. These results can be considered as a source of information for scientific research in the field of phytochemistry and pharmacology.展开更多
The problem of access to quality water is a major challenge, as it has a major impact on the socio-economic conditions of people in developing countries. The water from the islands of Lake Fitri is one of the main sou...The problem of access to quality water is a major challenge, as it has a major impact on the socio-economic conditions of people in developing countries. The water from the islands of Lake Fitri is one of the main sources of drinking water for the population. The aim of this study is to characterise and assess the quality of the water and sediment from the islands (Moudou and Birguime) of Lake Fitri, and to confirm the strains isolated using the PCR method. A total of fifty (50) samples of water and fifty (50) sediments from the islands of Lake Fitri were analyzed. Standard methods of microbiological and biochemical analysis of water and sediments were used. Isolated Enterobacteriaceae strains were characterized by API 20 E and API Staph galleries and Salmonella was confirmed by PCR method. Antibiotic resistance was determined using a technique recommended by the antibiogram committee of the French microbiology society (CA-SFM, 2019). The microbiological results for the water showed an abundance of total aerobic mesophilic flora (TAMF) (4.31 × 106 ± 8.05 × 105 and 5.29 × 106 ± 2.55 × 105) on the Birguime and Moudou islands successively. The microbiological results for the sediment from Birguime and Moudou islands showed an abundance of thermotolerant coliforms (E. coli) (2.05 × 105 ± 5.43 × 104 and 2.27 × 105 ± 3.49 × 104) alternately. The results obtained after incubation of the biochemical tests by the API 20E, API Staph gallery and their numerical profile proposed by the Api software confirmed the contamination. The antibiogram results showed the emergence of certain resistances to the antibiotics Tobramycin, Flucytosine, Amikacin and Teicoplani. The PCR results for Salmonella spp strains were confirmed. As a result, strict monitoring of the water on the various islands of Lake Fitri must be carried out throughout the annual cycle, by specialized personnel, to ensure proper bio-monitoring of these ecosystems.展开更多
The paper presents the results of the field and laboratory research carried out in the Chokheltkhevi river basin, according to which the sediment-forming solid mass accumulated in the bed of the Chokhelthkhevi river w...The paper presents the results of the field and laboratory research carried out in the Chokheltkhevi river basin, according to which the sediment-forming solid mass accumulated in the bed of the Chokhelthkhevi river was recorded and its granulometric and chemical composition, as well as physical-mechanical characteristics, were studied. Based on the results of the research, it can be said that in the debrisflow channel of the Chokheltkhevi River, coarse and sandy-clay soils are mainly accumulated, which represent an unstable mass for the expected debrisflow in the gorge, which, together with other geological, hydrological and climatic factors, helps to increase the scale of the expected ecological danger. According to the results of the laboratory research, it can be concluded that the soil accumulated in the drainage channel is low in ion concentration, and the humus content in it is minimal, which indicates the possibility of easy displacement of the solid mass accumulated in the drainage channel and, accordingly, the risk of a catastrophic debrisflow.展开更多
This study evaluates heavy metal pollution in soils from the Daniela oil sites located in the Kouno sub-prefecture, Loug-Chari Department. The primary objective is to determine the extent of heavy metal contamination ...This study evaluates heavy metal pollution in soils from the Daniela oil sites located in the Kouno sub-prefecture, Loug-Chari Department. The primary objective is to determine the extent of heavy metal contamination in the Daniela area. At the Raphia site, the metal concentration order is Cu > Mn > Fe > Cd > Pb, while at the Lanéa 1 and Lanéa 2 sites, it is Cu > Fe > Mn > Cd > Pb. Contamination factors (CF) for Mn, Fe, and Pb are very low (< 1), indicating no pollution from these metals. However, the contamination factors for Cd and Cu are significantly high according to the AFNOR standard. Additionally, the average contamination index across all three sites exceeds 2, confirming soil pollution by Cd and Cu at the sampled locations.展开更多
In this note, we estimate the maximum amplitude for the Solar Cycle 25. We use the curvature technique presented for earlier cycles by Verdes and coworkers. We further extrapolate the location of the solar maximum num...In this note, we estimate the maximum amplitude for the Solar Cycle 25. We use the curvature technique presented for earlier cycles by Verdes and coworkers. We further extrapolate the location of the solar maximum number of Sunspots, of which the prediction made is about 115 in the year 2025 and identify the arrival to the minimum in the year 2031, forecasting the main characteristics for the current Solar Cycle 25 and list a short comparison with a few other predictions.展开更多
Introduction: On the outskirts of Ndjamena, semi-industrial poultry farming and traditional poultry farming are practised informally on almost all poultry farms in Chad. This type of poultry farming is faced with real...Introduction: On the outskirts of Ndjamena, semi-industrial poultry farming and traditional poultry farming are practised informally on almost all poultry farms in Chad. This type of poultry farming is faced with real health problems attributable to a lack of monitoring of the vaccination schedule, inadequate compliance with biosecurity measures and poor application of the Ichikawa rule based on the 5 M’s. Objective: The aim of this article is to identify the microorganisms responsible for contamination of poultry farms in the study area. Method: The study was carried out from 28/04/2022 to 31/01/2023 on the basis of 300 samples taken from feed, drinking water, droppings and scrapings from poultry housing surfaces in the 30 farms that served as a framework for our research. Sampling was of the simple random type, and farms were selected on the basis of the farmers’ consent. The data were recorded on pre-established survey forms. Our study was cross-sectional, descriptive and prospective. Bacteria were isolated using the reference method NF EN ISO 6579 for Salmonella spp. and cultured on the specific medium eosin methylene blue (EMB) for Escherichia coli, Pseudomonas and Citrobacter freundii. Results: The following results emerged from this study: Escherichia coli (5.33%), Pseudomonas (1.33%), Citrobacter freundii (12%) and Salmonella paratyphi (21.68%). Conclusion: Of the 300 samples analysed, 121 (40.33%) were contaminated with pathogens. This high level of contamination is a health problem. The study shows that biosecurity is less satisfactory on the farms visited. Nevertheless, farms with a very satisfactory level of biosafety ensure food safety and variety for the population.展开更多
In this paper,the existence,uniqueness,asymptotic and global exponential stability of pseudo almost automorphic solution for a class of delayed Lasota-Wazewska model with impulsive effects are established by applying ...In this paper,the existence,uniqueness,asymptotic and global exponential stability of pseudo almost automorphic solution for a class of delayed Lasota-Wazewska model with impulsive effects are established by applying an appropriate fixed point theorem and Lyapunov functional method.Finally,a numerical example with simulation is given to illuminate our theoretical results.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
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The ramifications of global climate change and resource scarcities have made it imperative to re-examine the definition of sustainable energy-storage systems.It is crucial to recognize that not all renewable resources are inherently sustainable,and their full impact on the environment must be assessed.With the proliferation of invasive jellyfish species wreaking havoc on marine ecosystems and economies worldwide,utilizing overabundant jellyfish as a carbon source presents an opportunity to create energy-storage systems that are both financially beneficial and environmentally remediating.Accordingly,a comprehensive approach to sustainability also requires eco-friendly solutions throughout the entire lifecycle,from material sourcing to battery production,without compromising highperformance requirements.Currently,most electrode syntheses for lithium-ion batteries(LIBs) employed are energy-intensive,multiple-steps,complex,and additive-heavy.In response,this work pioneers the straightforward use of low-energy laser irradiation of a jellyfish biomass/silicon nanoparticle blend to encapsulate the silicon nanoparticles in-situ within the as-forming conductive carbonized matrix,creating sustainable and additive-free composite anodes.The self-standing anode is directly synthesized under ambient conditions and requires no post-processing.Here,a laser-synthesized conductive threedimensional porous carbon/silicon composite anode from raw jellyfish biomass for LIBs is presented,displaying outstanding cyclic stability(>1000 cycles),excellent capacity retention(>50% retention after1000 cycles),exceptional coulombic efficiency(>99%),superb reversible gravimetric capacity(>2000 mAh/g),and high rate performance capability(>1.6 A/g),paving a new path to future sustainable energy production.
文摘Recent technological advancements,such as portable electronics and electric vehicles,have created a pressing need for more efficient energy storage solutions.Lithium-ion batteries(LIBs)have been the preferred choice for these applications,with graphite being the standard anode material due to its stability.However,graphite falls short of meeting the growing demand for higher energy density,possessing a theoretical capacity that lags behind.To address this,researchers are actively seeking alternative materials to replace graphite in commercial batteries.One promising avenue involves lithiumalloying materials like silicon and phosphorus,which offer high theoretical capacities.Carbon-silicon composites have emerged as a viable option,showing improved capacity and performance over traditional graphite or pure silicon anodes.Yet,the existing methods for synthesizing these composites remain complex,energy-intensive,and costly,preventing widespread adoption.A groundbreaking approach is presented here:the use of a laser writing strategy to rapidly transform common organic carbon precursors and silicon blends into efficient“graphenic silicon”composite thin films.These films exhibit exceptional structural and energy storage properties.The resulting three-dimensional porous composite anodes showcase impressive attributes,including ultrahigh silicon content,remarkable cyclic stability(over 4500 cycles with∼40%retention),rapid charging rates(up to 10 A g^(-1)),substantial areal capacity(>5.1 mAh cm^(-2)),and excellent gravimetric capacity(>2400 mAh g^(-1) at 0.2 A g^(-1)).This strategy marks a significant step toward the scalable production of high-performance LIB materials.Leveraging widely available,cost-effective precursors,the laser-printed“graphenic silicon”composites demonstrate unparalleled performance,potentially streamlining anode production while maintaining exceptional capabilities.This innovation not only paves the way for advanced LIBs but also sets a precedent for transforming various materials into high-performing electrodes,promising reduced complexity and cost in battery production.
基金funding from the European Union’s Horizon 2020 Research&Innovation Programme(2211)under the Partnership for Research and Innovation in the Mediterranean Area(PRIMA)Project"SHARInG-MeD"from the Directorate-General for Scientific Research and Technological Development(DGRSDT)under the Projets de Recherche Formation-Universitaire(PRFU)Projects(D00L02UN120120230002,D01N01UN120120230005)。
文摘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.
文摘The aim of the present work is to assess the value of Detarium Senegalense by determining the content of total phenols, total flavonoids and total anthocyanins, and by evaluating the free radical scavenging activity of Detarium Senegalense extracts. For this purpose, sequential extraction using solvents of increasing polarity was essential. The various extracts obtained underwent phytochemical and biochemical analyses. Phytochemical screening revealed the presence of flavonoids, alkaloids, tannins, polyphenols, anthocyanins and steroids/terpenes. Quantitative analysis of total polyphenols, total flavonoids and total anthocyanins yielded the following results: total flavonoids (0.803 ± 0029 mg EQ/100g P for acetone extract of roots and 0.871 ± 0.401 mg EQ/100g P for methanol extract of leaves);total polyphenols (23.298 ± 12.68 mg EAG/100g P for acetone extract of roots and 24.69 ± 0.49 401 mg EAG/100g P for methanol extract of leaves);total monomeric anthocyanins (44.697 ± 0.939 mg EC3G/100g P and 16.699 ± 0.193 mg EC3G/100g P respectively for acetone and methanol extracts of stem bark). DPPH free radical scavenging activity was 1.674 ± 0.023 mg/mL for the acetone extract and 0.934 ± 0.24 mg/mL for the methanol extract of roots. .
文摘In this article, we study generating sets of the complete semigroups of binary relations defined by X-semilattices of unions of the class Σ<sub>8</sub>(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.
文摘The use of medicinal plants occupies an important place in traditional Chadian medicine, this study was carried out with the aim of listing the medicinal plants sold in the markets of the city of N’Djamena, and knowledge of the medicinal flora Chad, such as the leaves of Guiera senegalensis in Arabic called Khibeche, the roots of Cassia occidentalis called Am kwala-Kinkéliba in Arabic;the bark of Khaya senegalensis (Desv) A. Juss called Muraї in Arabic and the seeds of Trigonella foenum-graecum called Helbé in Arabic in order to treat the most frequently cited diseases such as malaria, the common cold, mother and newborn care, and typhoid. Ethnobotanical surveys were conducted from September to December 2022, in three markets in the city of N’Djamena, based on individual interviews using a semi-structured questionnaire, with 30 herbalists and traditional practitioners. Phytochemical screening analyses of the organs of four plants were carried out in the chemistry and biology laboratory of the Faculty of Exact and Applied Sciences (FSEA) following a standard protocol established by [1] and slightly modified by [2] [3]. The results of the surveys identified 68 species divided into fifty-five (55) genera and twenty-seven (27) families, the most represented of which were Caesalpiniaceae (10 species), Mimosaceae (5 species) and Combretaceae (4 species). The leaves were the most commonly used parts (43%), with decoction (70%) the most frequently used method of preparation. The oral route was the most popular with 73% of recipes. The phytochemical study revealed a wealth of secondary metabolites such as Trapezoidal Sterols, Alkaloids, Tannins, Flavonoids, Free Quinones, Anthocyane, Anthraquinones, Saponosides and Heterosides. These results can be considered as a source of information for scientific research in the field of phytochemistry and pharmacology.
文摘The problem of access to quality water is a major challenge, as it has a major impact on the socio-economic conditions of people in developing countries. The water from the islands of Lake Fitri is one of the main sources of drinking water for the population. The aim of this study is to characterise and assess the quality of the water and sediment from the islands (Moudou and Birguime) of Lake Fitri, and to confirm the strains isolated using the PCR method. A total of fifty (50) samples of water and fifty (50) sediments from the islands of Lake Fitri were analyzed. Standard methods of microbiological and biochemical analysis of water and sediments were used. Isolated Enterobacteriaceae strains were characterized by API 20 E and API Staph galleries and Salmonella was confirmed by PCR method. Antibiotic resistance was determined using a technique recommended by the antibiogram committee of the French microbiology society (CA-SFM, 2019). The microbiological results for the water showed an abundance of total aerobic mesophilic flora (TAMF) (4.31 × 106 ± 8.05 × 105 and 5.29 × 106 ± 2.55 × 105) on the Birguime and Moudou islands successively. The microbiological results for the sediment from Birguime and Moudou islands showed an abundance of thermotolerant coliforms (E. coli) (2.05 × 105 ± 5.43 × 104 and 2.27 × 105 ± 3.49 × 104) alternately. The results obtained after incubation of the biochemical tests by the API 20E, API Staph gallery and their numerical profile proposed by the Api software confirmed the contamination. The antibiogram results showed the emergence of certain resistances to the antibiotics Tobramycin, Flucytosine, Amikacin and Teicoplani. The PCR results for Salmonella spp strains were confirmed. As a result, strict monitoring of the water on the various islands of Lake Fitri must be carried out throughout the annual cycle, by specialized personnel, to ensure proper bio-monitoring of these ecosystems.
文摘The paper presents the results of the field and laboratory research carried out in the Chokheltkhevi river basin, according to which the sediment-forming solid mass accumulated in the bed of the Chokhelthkhevi river was recorded and its granulometric and chemical composition, as well as physical-mechanical characteristics, were studied. Based on the results of the research, it can be said that in the debrisflow channel of the Chokheltkhevi River, coarse and sandy-clay soils are mainly accumulated, which represent an unstable mass for the expected debrisflow in the gorge, which, together with other geological, hydrological and climatic factors, helps to increase the scale of the expected ecological danger. According to the results of the laboratory research, it can be concluded that the soil accumulated in the drainage channel is low in ion concentration, and the humus content in it is minimal, which indicates the possibility of easy displacement of the solid mass accumulated in the drainage channel and, accordingly, the risk of a catastrophic debrisflow.
文摘This study evaluates heavy metal pollution in soils from the Daniela oil sites located in the Kouno sub-prefecture, Loug-Chari Department. The primary objective is to determine the extent of heavy metal contamination in the Daniela area. At the Raphia site, the metal concentration order is Cu > Mn > Fe > Cd > Pb, while at the Lanéa 1 and Lanéa 2 sites, it is Cu > Fe > Mn > Cd > Pb. Contamination factors (CF) for Mn, Fe, and Pb are very low (< 1), indicating no pollution from these metals. However, the contamination factors for Cd and Cu are significantly high according to the AFNOR standard. Additionally, the average contamination index across all three sites exceeds 2, confirming soil pollution by Cd and Cu at the sampled locations.
文摘In this note, we estimate the maximum amplitude for the Solar Cycle 25. We use the curvature technique presented for earlier cycles by Verdes and coworkers. We further extrapolate the location of the solar maximum number of Sunspots, of which the prediction made is about 115 in the year 2025 and identify the arrival to the minimum in the year 2031, forecasting the main characteristics for the current Solar Cycle 25 and list a short comparison with a few other predictions.
文摘Introduction: On the outskirts of Ndjamena, semi-industrial poultry farming and traditional poultry farming are practised informally on almost all poultry farms in Chad. This type of poultry farming is faced with real health problems attributable to a lack of monitoring of the vaccination schedule, inadequate compliance with biosecurity measures and poor application of the Ichikawa rule based on the 5 M’s. Objective: The aim of this article is to identify the microorganisms responsible for contamination of poultry farms in the study area. Method: The study was carried out from 28/04/2022 to 31/01/2023 on the basis of 300 samples taken from feed, drinking water, droppings and scrapings from poultry housing surfaces in the 30 farms that served as a framework for our research. Sampling was of the simple random type, and farms were selected on the basis of the farmers’ consent. The data were recorded on pre-established survey forms. Our study was cross-sectional, descriptive and prospective. Bacteria were isolated using the reference method NF EN ISO 6579 for Salmonella spp. and cultured on the specific medium eosin methylene blue (EMB) for Escherichia coli, Pseudomonas and Citrobacter freundii. Results: The following results emerged from this study: Escherichia coli (5.33%), Pseudomonas (1.33%), Citrobacter freundii (12%) and Salmonella paratyphi (21.68%). Conclusion: Of the 300 samples analysed, 121 (40.33%) were contaminated with pathogens. This high level of contamination is a health problem. The study shows that biosecurity is less satisfactory on the farms visited. Nevertheless, farms with a very satisfactory level of biosafety ensure food safety and variety for the population.
文摘In this paper,the existence,uniqueness,asymptotic and global exponential stability of pseudo almost automorphic solution for a class of delayed Lasota-Wazewska model with impulsive effects are established by applying an appropriate fixed point theorem and Lyapunov functional method.Finally,a numerical example with simulation is given to illuminate our theoretical results.
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.
