During high-temperature periods in summer,formaldehyde(HCHO)levels increase due to secondary production.However,recent studies have also shown a rise in the HCHO concentration in winter,but the underlying cause remain...During high-temperature periods in summer,formaldehyde(HCHO)levels increase due to secondary production.However,recent studies have also shown a rise in the HCHO concentration in winter,but the underlying cause remains unclear.Here,HCHO observations in urban Beijing were conducted,the impact of meteorological differences between warm and cold seasons to HCHO concentrations was investigated.Additionally,the positive matrix factorization model was applied to the source apportionment of HCHO,with a focus on changes during pollution events.The results indicated that,during warm seasons,the secondary production of HCHO was driven by high temperature influenced by the low-pressure front,with the contribution of secondary production+background peaking at 85.9% in the afternoon,exhibiting a unimodal diurnal variation.Conversely,during cold seasons,the influence of a uniform pressure field,coupled with weak winds,low boundary layers and high humidity,led to HCHO accumulation from primary emissions,resulting in multiday highconcentration pollution.During the most severe pollution periods,anthropogenic primary emissions contributed up to 91.7%.Therefore,while the contribution of volatile organic compounds to HCHO levels through secondary production has been recognized,the significant impact of primary emissions during cold seasons cannot be overlooked.展开更多
Introduction: Infection disease is a real publique health problem. The rise of resistance for modern antibiotic in infections treatment imposed us order alternatives. The study objective was to contribute in the knowl...Introduction: Infection disease is a real publique health problem. The rise of resistance for modern antibiotic in infections treatment imposed us order alternatives. The study objective was to contribute in the knowledge of medicinal plants uses in urinary infections treatment in N’Djamena (Chad) in view for amelioration the traditional medicine in future. Methodology: The study was conducted in the city of N’Djamena in the Republic of Chad that interviewed 60 traditherapists on using 11 plants for urinary tract infections treatment. The methodology of this study consisted of the knowledge of medicinal plants that used by traditherapists, and the plants identification was done in the laboratory of IRED at Farcha. Results: A total of 60 traditherapists was interrogated on the plants used in the treatment of urinary tract infections among the population of N’Djamena. The majority of traditherapists interrogated in this study were male with the rate of 61.67% against female with the rate of 38.33%. The age range of traditherapists was between 20 to 80 years, 25 (41.67%) from the age range between 30 - 50 years and 35 (58.33%) in age range from 50 to 70 years. For the origin of their knowledge, the study showed that 72% of traditherapists inherited the knowledge from their family, while 15% inherited from the family and from training. The ethnic groups of the traditherapists were Sara (16%), Maraba (12%) and Massa (11%). According to the results, 18.33% were illiterates, 49% attended primary school and 33.34% the secondary school. Our study found that 11 species of plants belonging to 11 families were used in the treatment of urinary tract infection and the Ziziphus spina-christi was the most represented. According to traditherapists the Ziziphus spina-christi, Cassia obovata and Euphorbia hirta were the most frequent plants used in the urinary tract infections treatment. The parts of plants used in the treatment were leaves and bark, grained leaves and entire plants with the proportion of 50%, 16.67 and 15% respectively. Conclusion: This study revealed that the medicinal plants are variously used in the treatment of infection urinary tract in the city of N’Djamena.展开更多
The conservation of plant biodiversity has become one of the most important objectives in the sustainable management of Guinean-Congolese ecosystems. However, in the south-east zone of Cameroon, there is a lack of rig...The conservation of plant biodiversity has become one of the most important objectives in the sustainable management of Guinean-Congolese ecosystems. However, in the south-east zone of Cameroon, there is a lack of rigor in the management of these forests, which can result in the loss of species of high conservation value. The study was carried out in communal forests in the south-east zone of Cameroon. Its aim was to carry out a floristic inventory and then compare the list of species with the IUCN catalog. Twenty-four plots, each with a surface area of 0.2 ha, were set up in the Gari-Gombo communal forest. All timbers with a DBH ≥ 5 cm were systematically counted. A total of 176 species, belonging to 144 genera and 45 families, were surveyed. Fabaceae (42.08%), Malvaceae (39%), Euphorbiaceae (24.64%), Moraceae (20.92%), Apocynaceae (18.64%), Cecropiaceae (16.60%), Ulmaceae (14.76%), Meliaceae (14.61%), Violaceae (14.08%), Combretaceae (12.67%), Theobroma cacao (21.17%), Baphia leptobotrys (18.06%), Rinorea sp. (14.09%), Musanga cecropioides (12.18%), Terminalia superba (10.32%), Neosloetiopsis kamerunensis (10.14%), Celtis zenkeri (8.29%) and Alstonia boonei (7.77%) were the most important taxa. Nearly 90% of the species in this forest are Guinean species, with a dominance of Guinean-Congolese species (66%). Fourteen (14) threatened species have been identified in the FCGG. This study, which highlights the rich biodiversity of communal forests, is important for guiding biodiversity conservation policies in ecosystems used for production.展开更多
“Integration is a hallmark of our era's development and a magic key to solve epochal problems.”“Medicine originated from humanity's initial expression of suffering and the primary desire to alleviate that s...“Integration is a hallmark of our era's development and a magic key to solve epochal problems.”“Medicine originated from humanity's initial expression of suffering and the primary desire to alleviate that suffering.”展开更多
Highly weathered soils are distributed in the humid and wet-dry tropics, as well as in the humid subtropics. As a result of strong weathering, these soils are characterized by low activity clays, which develop variabl...Highly weathered soils are distributed in the humid and wet-dry tropics, as well as in the humid subtropics. As a result of strong weathering, these soils are characterized by low activity clays, which develop variable surface charge and related specific properties. Surface reactions regarding base exchange and soil acidification, heavy metal sorption and mobility, and phosphorus sorption and availability of the tropical highly weathered soils are reviewed in this paper.Factors controlling surface reactivity towards cations and anions, including ion exchange and specific adsorption processes, are discussed with consideration on practical implications for rational management of these soils. Organic matter content and pH value are major basic factors that should be controlled through appropriate agricultural practices, in order to optimise favorable effects of colloid surface properties on soil fertility and environmental quality.展开更多
This study was carried out in the forest reserve of Mbalmayo, Center Region of Cameroon, with the aim to analyze the dynamics of land use/land cover (LULC) changes over the past 30 years. The databases used were made ...This study was carried out in the forest reserve of Mbalmayo, Center Region of Cameroon, with the aim to analyze the dynamics of land use/land cover (LULC) changes over the past 30 years. The databases used were made up of 3 Landsat satellite images (5TM of 1990, 7ETM+ of 2005 and 8OLI of 2020). The satellite images were processed using ArcGIS and Erdas Imagine software. Ethnobotanical surveys were conducted to investigate the relationships between the local population and the forest reserve. The Mbalmayo forest reserve is consisted of seven main land cover namely: mature secondary forest, young secondary forest, savanna, fallows and crops, built, bare soil and water surface. The dynamics of the forest cover undergoes more significant changes between the years 1990-2005 with losses estimate at 4762 ha compared to the years 2005-2020 (2231 ha), with a marked decrease in the area of dense forests. This regression is much more important in dense forest vegetation. The forest cover lost 6993 ha (26.92%) of its surface, which corresponds to an average rate of deforestation of 233.1 ha/year. The survey revealed the need for NTFPs for the Mbalmayo reserve forest populations. Indeed, all respondents agreed that they use non-timber forest products from the forest, mainly for medication (37%), wood (34%) and food (24%). Therefore, it becomes urgent to redefine a management plan for the Mbalmayo forest reserve which will define how the forest must be managed in order to avoid the loss of large areas of forests disappearing each year under the human action, which exerts pressure on forest species, thus leading to their possible disappearance.展开更多
Sorghum bicolor is among main staple crops of Chad but it is commonly attacked by Striga hermonthica. Assessment of sorghum varieties for resistance to this weed was carried out during three cropping seasons （2005-2...Sorghum bicolor is among main staple crops of Chad but it is commonly attacked by Striga hermonthica. Assessment of sorghum varieties for resistance to this weed was carried out during three cropping seasons （2005-2008）, in controlled conditions; promising entries （those which fulfilled at least 75% of selection criteria） were evaluated in farmer field in 2008-2009 seasons. There were five sites （Bebedjia, Deli, Bekao, Koudoti and Ndaba）. The objective was to evaluate some sorghum entries for S. hermonthica resistance in farmer field. Sorghum test was composed of four entries in Fisher blocks as experimental designs, with five replications. Among different observed variables, there were striga plant count and weight of sorghum grains. One promising entry was selected at Bebedjia and Ndaba （53）, two at Deli and Koudoti （50 and 53）. No entry was selected at Bekao. Promising entries for the whole Southern zone of Chad were composed of 50 and 53. The best entry was 53 because it was promising in all sites except Bekao.展开更多
The purpose of the study was to establish the structure of monitored animal farms and determine reproductive parameters of Sahelian goats in the Guera Region, in Central Chad. Data were collected through longitudinal ...The purpose of the study was to establish the structure of monitored animal farms and determine reproductive parameters of Sahelian goats in the Guera Region, in Central Chad. Data were collected through longitudinal survey in 27 observatory farms during three years using goats identified by numbered ear tags. The herds were composed on average of about 71% of females. The age pyramid covering all years showed a significant number of males aged between 0 - 1 year and perceptible fall thereafter. However, some stability was observed in the class of the 2 - 8 years old among females. The frequencies of accumulated kiddings showed that 44% of births occurred in the rainy season against 28% respectively in the cool dry and hot dry seasons. Obtained reproduction parameters were: a sex ratio of 0.51 in favor of males, a kidding interval of 10.6 months with significant differences (P < 0.05) according to the rank of birth, an age at first kidding of 16.5 months for females born in monitoring and an age of 20.3 months for all first-kidding, giving an apparent fertility rate of 145%, a fecundity rate of 116% and an abortion rate of 2%. The composition and structure of herds have highlighted the importance of females to ensure the reproducibility of goat production systems. The determined reproduction parameters are references for actions to improve goat rearing in this area.展开更多
The effects of climate change have had a major impact on forage availability in the Sahel and Saharan regions of Chad in recent years. This has led to the migration of farmers in search of long-distance grazing, thus ...The effects of climate change have had a major impact on forage availability in the Sahel and Saharan regions of Chad in recent years. This has led to the migration of farmers in search of long-distance grazing, thus impacting the potential of the animals to produce good quality milk and meat. It is with this in mind that this study was conducted on the knowledge of feeding practices of animals in the provinces of Wadi-Fira and West-Ennedi (Chad) during the lean period. More specifically, it is a question of collecting some information on the plants consumed by the animals and the way in which the breeders formulate the food ration of their herds in times of deficit. It emerges from this investigation that the herds of animals in the province of Wadi-Fira faced with forage deficit and adapted by consuming the leaves, fruits and seeds of certain tropical plants such as Capparis decidua, Ziziphus mauritiana, Balanites aegyptiaca, Acacia tortilis, Boscia senegalensis, Salvadora percica and Tribulis terristris to compensate for food shortages. This same observation was made in the province of West-Ennedi, since this area is desert with annual precipitation of 150 mm. Natural pasture is only available around water points (ouadis and oasis) in a small area with a high number of herds. Thus, the herds also face a drastic lack of grazing during the deficit periods. However, they adapt by consuming the leaves, fruits and seeds of plants such as Bauhinia sp., Boscia senegalenis, Acacia tortilis, Tribulis terristris, Boscia angustifolia, Bicoma tomentosa, Blepharis linarifolia and Aristida funiculata during lean periods to meet their food requirements. The formulation of the feed ration for animals differs from one area to another. It is mainly based on residues from cereals such as millet (Panicum miliaceum) and sorghum (Sorghum bicolor).展开更多
This study is being carried out in the cross-border area of </span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-fam...This study is being carried out in the cross-border area of </span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">the tri-national Dja-Odzala-Minkébé (TRIDOM), subject of a cooperation agreement between Cameroon, Congo a</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">nd Gabon in 2005. The purpose of this study is to analyze the dynamics of changes in land use in the context of cross-border cooperation. Geographic information systems and remote sensing were used to produce the various land use maps. For this purpose, the MERIS satellite images for the periods 1992, 2005 and 2018 were used. The exploration of the different images and the field visits made it possible to identify the following six land use classes: dense forests, degraded/deforested forests, savannas, swamp forests, buildings and bare soils, water surfaces. It emerges that the TRIDOM landscape is mainly occupied by dense forests which represent 97.02%, 96.72% and 96.52% respectively in 1992, 2005 and 2018. Then, degraded/deforested forests and savannas which would correspond to cultivation areas and fallow land only represent respectively 1.06% and 0.68% of the landscape in 1992. This proportion in 2005 is respectively 1.22% and 0.77%, whereas in 2018, it is respectively 1.36% and 0.81% of the massif. The landscape of TRIDOM has not experienced any significant land use change during the period after the signing of the cooperation agreement. Historical rates of deforestation are low during the period under study. They are estimated at 0.042% and 0.030% respectively for the period 1992-2005 and the period 2005-2018. These low rates of deforestation seem to be due to the measures taken to secure and sustainably manage the massif taken by the three countries, the low population density in this area and the still difficult level of accessibility of a large part of the massif.展开更多
The eastern and southern regions of Cameroon, lower middle income country, need to increase their level of land use by the agricultural, forestry and mining sectors in order to develop. At the same time, Cameroon is c...The eastern and southern regions of Cameroon, lower middle income country, need to increase their level of land use by the agricultural, forestry and mining sectors in order to develop. At the same time, Cameroon is committed to managing its forests sustainably to meet the needs of present and future generations. This study assesses the compatibility of agricultural, forestry and mining policies with sustainable forest management in the East and South forest regions. Five analytical criteria were used and the analysis was carried out through surveys of key informants in the private sector, public administrations and civil society. The study showed that from 2013 to 2018, the contributions of the agricultural, forestry and mining sectors to GDP grew by about 74%, 65% and 60%, respectively. Agricultural, forestry and mining policies have an average compatibility rate of 45% with sustainable forest management, of which 52% for the forestry sector, 43% for the agricultural sector and 40% for the mining sector. Nonetheless, there are 21 causes of incompatibility, including 1) the non-involvement of all relevant public administrations in policy-making, 2) the low efficiency of the control system of exploitation activities, and 3) the poor coordination of actions in the three sectors. It was proposed to a) improve the legal and regulatory framework of the three sectors of activity and b) develop land-use planning tools among other measures to align existing policies with sustainable forest management.展开更多
Holistic integrative medicine,abbreviated as HIM,has been officially proposed since 2012.Its theoretical system has been continuously improved,and its practical methods have become increasingly diverse,becoming an ine...Holistic integrative medicine,abbreviated as HIM,has been officially proposed since 2012.Its theoretical system has been continuously improved,and its practical methods have become increasingly diverse,becoming an inevitable choice and path for the medical development in the new era.This article demonstrates ten major propositions for HIM,elaborating on the connotation and extension of HIM from the perspectives of epistemology and methodology,in order to achieve the transformation and adaptive evolution of modernmedicine.展开更多
This study quantified the regional damages resulting from temperature and sea level changes using the Regional Integrated of Climate and Economy(RICE)model,as well as the effects of enabling and disabling the climate ...This study quantified the regional damages resulting from temperature and sea level changes using the Regional Integrated of Climate and Economy(RICE)model,as well as the effects of enabling and disabling the climate impact module on future emission pathways.Results highlight varied damages depending on regional economic development and locations.Specifically,China and Africa could suffer the most serious comprehensive damages caused by temperature change and sea level rise,followed by India,other developing Asian countries(OthAsia),and other high-income countries(OHI).The comprehensive damage fractions for China and Africa are projected to be 15.1%and 12.5%of gross domestic product(GDP)in 2195,with corresponding cumulative damages of 124.0 trillion and 87.3 trillion United States dollars(USD)from 2005 to 2195,respectively.Meanwhile,the comprehensive damage fractions in Japan,Eurasia,and Russia are smaller and projected to be lower than 5.6%of GDP in 2195,with cumulative damages of 6.8 trillion,4.2 trillion,and 3.3 trillion USD,respectively.Additionally,coastal regions like Africa,the European Union(EU),and OHI show comparable damages for sea level rise and temperature change.In China,however,sea level-induced damages are projected to exceed those from temperature changes.Moreover,this study indicates that switching the damage modules on or off affects the regional and global emission trajectories,but the magnitude is relatively small.By 2195,global emissions under the experiments with all of the damage modules switched off,only the sea level damage module switched on,and only the temperature damage module switched on,were 3.5%,2.3%and 1.2%higher than those with all of the damage modules switched on,respectively.展开更多
Holistic integrative medicine,abbreviated as HIM,has been officially proposed since 2012.Its theoretical system has been continuously improved,and its practical methods have become increasingly diverse,becoming an ine...Holistic integrative medicine,abbreviated as HIM,has been officially proposed since 2012.Its theoretical system has been continuously improved,and its practical methods have become increasingly diverse,becoming an inevitable choice and path for the medical development in the new era.This article demonstrates ten major propositions for HIM,elaborating on the connotation and extension of HIM fromthe perspectives of epistemology and methodology,in order to achieve the transformation and adaptive evolution of modern medicine.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
The mass elevation effect(MEE)of the Tibetan Plateau(TP)has attracted the attention of geographers because of its significant influence on the Asian climate,snow line,timberline,and other important climate-ecological ...The mass elevation effect(MEE)of the Tibetan Plateau(TP)has attracted the attention of geographers because of its significant influence on the Asian climate,snow line,timberline,and other important climate-ecological boundaries of the plateau and on global ecological patterns.In recent years,much progress has been made in quantifying the MEE of TP.However,factors that affect the size of MEE have not been examined in depth,and the key factors still remain unclear.Based on quantification of MEE for each mountain basal elevation plot,this study identifies the factors that contribute significantly to MEE of the plateau.Seven factors are considered,including mountain basal elevation,distance from the core zone of MEE,thermal continentality,maximum elevation,height difference,area,and difference of underlying surface(with the yearly max"Normalized Difference Vegetation Index"(NDVI)serving as a quantitative indicator).We also used these seven factors as independent variables to develop a multiple linear regression model for MEE of the plateau.Results show that:(1)the determination coefficient(R2)of the model reaches as high as 0.877,and the contributions of mountain basal elevation,distance from the core zone of MEE,thermal continentality,maximum elevation,topographical height difference,area,and NDVI are 39.77%,23.02%,14.48%,5.78%,11.41%,2.92%,and 2.62%,respectively,with mountain basal elevation and the distance from the core of MEE as the most important factors;(2)thermal continentality and MEE are significantly correlated,and maximum elevation only has a coupling relationship with MEE,with height difference and NDVI contributing little to MEE.This study deepens our understanding of MEE and its forming factors in the Tibetan Plateau.展开更多
In operations management, the learning curve has been an effective tool in estimating operator performance. However, discontinuities in work disrupt the learning process and a phenomenon called remission or forgetting...In operations management, the learning curve has been an effective tool in estimating operator performance. However, discontinuities in work disrupt the learning process and a phenomenon called remission or forgetting occurs, resulting in increased time of performing the task upon resumption of work. The study aims to identify variables that significantly affect the remission rate of sewing operations in a manufacturing setting. Four variables--length of stint 1, percent Differenceat stint t, gender, and product family, were identified. Statistical analyses, such as paired t-test, correlation, regression, and analysis of variance （ANOVA） were conducted in order to observe the relationships between the dependent variable and independent variables. For the results of the first general regression, gender was found to be an insignificant variable in predicting remission rate, while product family, length of stint 1, and percent Differenceat stint I were statistically significant. Moreover, the final general regression, which excluded the insignificant gender variable and considered the （regrouped） product families, revealed that product family, length of stint 1, and percent Differenceat stint 1 were still statistically significant. Length of stint 1 had a moderately positive correlation with remission rate, while percent Differenceat stint i had a moderately negative correlation with remission rate. Also, percent Differenceat stint 1 was the largest contributor to the remission rate model. In terms of R2, the goodness-of-fit of the model is moderate. Finally, the model yielded an absolute error of 5.08%, indicating a high accuracy in predicting remission rate.展开更多
This study provides a harmonization framework for common capital flight policies in Africa.It builds on evidence of persistent extreme poverty in the continent to assess how common measures can be adopted by sampled c...This study provides a harmonization framework for common capital flight policies in Africa.It builds on evidence of persistent extreme poverty in the continent to assess how common measures can be adopted by sampled countries on one cause of extreme poverty:capital flight.The dataset is sub-divided into fundamental characteristics of African capital flight based on income levels,legal foundations,natural resources,political stability,regional proximity,and religious domination.The main finding shows that from a projection date of 2010,a feasible timeframe for harmonizing policies is between 2016 and 2023.This timeframe coincides with the beginning of the post-2015 agenda on sustainable development goals.展开更多
Rice genes OsDjA2 and OsERF104,encoding a chaperone protein and an APETELA2/ethylene-responsive factor,respectively,are strongly induced in a compatible interaction with blast fungus,and also have function in plant su...Rice genes OsDjA2 and OsERF104,encoding a chaperone protein and an APETELA2/ethylene-responsive factor,respectively,are strongly induced in a compatible interaction with blast fungus,and also have function in plant susceptibility validated through gene silencing.Here,we reported the CRISPR/Cas9 knockout of OsDjA2 and OsERF104 genes resulting in considerable improvement of blast resistance.A total of 15 OsDjA2(62.5%)and 17 OsERF104(70.8%)T_(0)transformed lines were identified from 24 regenerated plants for each target and used in downstream experiments.Phenotyping of homozygous T1 mutant lines revealed not only a significant decrease in the number of blast lesions but also a reduction in the percentage of diseased leaf area,compared with the infected control plants.Our results supported CRISPR/Cas9-mediated target mutation in rice susceptibility genes as a potential and alternative breeding strategy for building resistance to blast disease.展开更多
基金supported by the National Natural Science Foundation of China(Nos.42075097 and 42177081)the National Key R&D Program of China(No.2023YFC3706103)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0760200)Beijing Municipal Natural Science Foundation(No.8222075)the Youth Cross Team Scientific Research Project of the Chinese Academy of Sciences(No.JCTD-2021-10)。
文摘During high-temperature periods in summer,formaldehyde(HCHO)levels increase due to secondary production.However,recent studies have also shown a rise in the HCHO concentration in winter,but the underlying cause remains unclear.Here,HCHO observations in urban Beijing were conducted,the impact of meteorological differences between warm and cold seasons to HCHO concentrations was investigated.Additionally,the positive matrix factorization model was applied to the source apportionment of HCHO,with a focus on changes during pollution events.The results indicated that,during warm seasons,the secondary production of HCHO was driven by high temperature influenced by the low-pressure front,with the contribution of secondary production+background peaking at 85.9% in the afternoon,exhibiting a unimodal diurnal variation.Conversely,during cold seasons,the influence of a uniform pressure field,coupled with weak winds,low boundary layers and high humidity,led to HCHO accumulation from primary emissions,resulting in multiday highconcentration pollution.During the most severe pollution periods,anthropogenic primary emissions contributed up to 91.7%.Therefore,while the contribution of volatile organic compounds to HCHO levels through secondary production has been recognized,the significant impact of primary emissions during cold seasons cannot be overlooked.
文摘Introduction: Infection disease is a real publique health problem. The rise of resistance for modern antibiotic in infections treatment imposed us order alternatives. The study objective was to contribute in the knowledge of medicinal plants uses in urinary infections treatment in N’Djamena (Chad) in view for amelioration the traditional medicine in future. Methodology: The study was conducted in the city of N’Djamena in the Republic of Chad that interviewed 60 traditherapists on using 11 plants for urinary tract infections treatment. The methodology of this study consisted of the knowledge of medicinal plants that used by traditherapists, and the plants identification was done in the laboratory of IRED at Farcha. Results: A total of 60 traditherapists was interrogated on the plants used in the treatment of urinary tract infections among the population of N’Djamena. The majority of traditherapists interrogated in this study were male with the rate of 61.67% against female with the rate of 38.33%. The age range of traditherapists was between 20 to 80 years, 25 (41.67%) from the age range between 30 - 50 years and 35 (58.33%) in age range from 50 to 70 years. For the origin of their knowledge, the study showed that 72% of traditherapists inherited the knowledge from their family, while 15% inherited from the family and from training. The ethnic groups of the traditherapists were Sara (16%), Maraba (12%) and Massa (11%). According to the results, 18.33% were illiterates, 49% attended primary school and 33.34% the secondary school. Our study found that 11 species of plants belonging to 11 families were used in the treatment of urinary tract infection and the Ziziphus spina-christi was the most represented. According to traditherapists the Ziziphus spina-christi, Cassia obovata and Euphorbia hirta were the most frequent plants used in the urinary tract infections treatment. The parts of plants used in the treatment were leaves and bark, grained leaves and entire plants with the proportion of 50%, 16.67 and 15% respectively. Conclusion: This study revealed that the medicinal plants are variously used in the treatment of infection urinary tract in the city of N’Djamena.
文摘The conservation of plant biodiversity has become one of the most important objectives in the sustainable management of Guinean-Congolese ecosystems. However, in the south-east zone of Cameroon, there is a lack of rigor in the management of these forests, which can result in the loss of species of high conservation value. The study was carried out in communal forests in the south-east zone of Cameroon. Its aim was to carry out a floristic inventory and then compare the list of species with the IUCN catalog. Twenty-four plots, each with a surface area of 0.2 ha, were set up in the Gari-Gombo communal forest. All timbers with a DBH ≥ 5 cm were systematically counted. A total of 176 species, belonging to 144 genera and 45 families, were surveyed. Fabaceae (42.08%), Malvaceae (39%), Euphorbiaceae (24.64%), Moraceae (20.92%), Apocynaceae (18.64%), Cecropiaceae (16.60%), Ulmaceae (14.76%), Meliaceae (14.61%), Violaceae (14.08%), Combretaceae (12.67%), Theobroma cacao (21.17%), Baphia leptobotrys (18.06%), Rinorea sp. (14.09%), Musanga cecropioides (12.18%), Terminalia superba (10.32%), Neosloetiopsis kamerunensis (10.14%), Celtis zenkeri (8.29%) and Alstonia boonei (7.77%) were the most important taxa. Nearly 90% of the species in this forest are Guinean species, with a dominance of Guinean-Congolese species (66%). Fourteen (14) threatened species have been identified in the FCGG. This study, which highlights the rich biodiversity of communal forests, is important for guiding biodiversity conservation policies in ecosystems used for production.
基金released in Chengdu on June 22,2024,jointly signed and advocated by over 100 academicians from Chinese Academy of Sciences and Chinese Academy of Engineering,and more than 100 presidents from medical universities across China.
文摘“Integration is a hallmark of our era's development and a magic key to solve epochal problems.”“Medicine originated from humanity's initial expression of suffering and the primary desire to alleviate that suffering.”
文摘Highly weathered soils are distributed in the humid and wet-dry tropics, as well as in the humid subtropics. As a result of strong weathering, these soils are characterized by low activity clays, which develop variable surface charge and related specific properties. Surface reactions regarding base exchange and soil acidification, heavy metal sorption and mobility, and phosphorus sorption and availability of the tropical highly weathered soils are reviewed in this paper.Factors controlling surface reactivity towards cations and anions, including ion exchange and specific adsorption processes, are discussed with consideration on practical implications for rational management of these soils. Organic matter content and pH value are major basic factors that should be controlled through appropriate agricultural practices, in order to optimise favorable effects of colloid surface properties on soil fertility and environmental quality.
文摘This study was carried out in the forest reserve of Mbalmayo, Center Region of Cameroon, with the aim to analyze the dynamics of land use/land cover (LULC) changes over the past 30 years. The databases used were made up of 3 Landsat satellite images (5TM of 1990, 7ETM+ of 2005 and 8OLI of 2020). The satellite images were processed using ArcGIS and Erdas Imagine software. Ethnobotanical surveys were conducted to investigate the relationships between the local population and the forest reserve. The Mbalmayo forest reserve is consisted of seven main land cover namely: mature secondary forest, young secondary forest, savanna, fallows and crops, built, bare soil and water surface. The dynamics of the forest cover undergoes more significant changes between the years 1990-2005 with losses estimate at 4762 ha compared to the years 2005-2020 (2231 ha), with a marked decrease in the area of dense forests. This regression is much more important in dense forest vegetation. The forest cover lost 6993 ha (26.92%) of its surface, which corresponds to an average rate of deforestation of 233.1 ha/year. The survey revealed the need for NTFPs for the Mbalmayo reserve forest populations. Indeed, all respondents agreed that they use non-timber forest products from the forest, mainly for medication (37%), wood (34%) and food (24%). Therefore, it becomes urgent to redefine a management plan for the Mbalmayo forest reserve which will define how the forest must be managed in order to avoid the loss of large areas of forests disappearing each year under the human action, which exerts pressure on forest species, thus leading to their possible disappearance.
文摘Sorghum bicolor is among main staple crops of Chad but it is commonly attacked by Striga hermonthica. Assessment of sorghum varieties for resistance to this weed was carried out during three cropping seasons （2005-2008）, in controlled conditions; promising entries （those which fulfilled at least 75% of selection criteria） were evaluated in farmer field in 2008-2009 seasons. There were five sites （Bebedjia, Deli, Bekao, Koudoti and Ndaba）. The objective was to evaluate some sorghum entries for S. hermonthica resistance in farmer field. Sorghum test was composed of four entries in Fisher blocks as experimental designs, with five replications. Among different observed variables, there were striga plant count and weight of sorghum grains. One promising entry was selected at Bebedjia and Ndaba （53）, two at Deli and Koudoti （50 and 53）. No entry was selected at Bekao. Promising entries for the whole Southern zone of Chad were composed of 50 and 53. The best entry was 53 because it was promising in all sites except Bekao.
文摘The purpose of the study was to establish the structure of monitored animal farms and determine reproductive parameters of Sahelian goats in the Guera Region, in Central Chad. Data were collected through longitudinal survey in 27 observatory farms during three years using goats identified by numbered ear tags. The herds were composed on average of about 71% of females. The age pyramid covering all years showed a significant number of males aged between 0 - 1 year and perceptible fall thereafter. However, some stability was observed in the class of the 2 - 8 years old among females. The frequencies of accumulated kiddings showed that 44% of births occurred in the rainy season against 28% respectively in the cool dry and hot dry seasons. Obtained reproduction parameters were: a sex ratio of 0.51 in favor of males, a kidding interval of 10.6 months with significant differences (P < 0.05) according to the rank of birth, an age at first kidding of 16.5 months for females born in monitoring and an age of 20.3 months for all first-kidding, giving an apparent fertility rate of 145%, a fecundity rate of 116% and an abortion rate of 2%. The composition and structure of herds have highlighted the importance of females to ensure the reproducibility of goat production systems. The determined reproduction parameters are references for actions to improve goat rearing in this area.
文摘The effects of climate change have had a major impact on forage availability in the Sahel and Saharan regions of Chad in recent years. This has led to the migration of farmers in search of long-distance grazing, thus impacting the potential of the animals to produce good quality milk and meat. It is with this in mind that this study was conducted on the knowledge of feeding practices of animals in the provinces of Wadi-Fira and West-Ennedi (Chad) during the lean period. More specifically, it is a question of collecting some information on the plants consumed by the animals and the way in which the breeders formulate the food ration of their herds in times of deficit. It emerges from this investigation that the herds of animals in the province of Wadi-Fira faced with forage deficit and adapted by consuming the leaves, fruits and seeds of certain tropical plants such as Capparis decidua, Ziziphus mauritiana, Balanites aegyptiaca, Acacia tortilis, Boscia senegalensis, Salvadora percica and Tribulis terristris to compensate for food shortages. This same observation was made in the province of West-Ennedi, since this area is desert with annual precipitation of 150 mm. Natural pasture is only available around water points (ouadis and oasis) in a small area with a high number of herds. Thus, the herds also face a drastic lack of grazing during the deficit periods. However, they adapt by consuming the leaves, fruits and seeds of plants such as Bauhinia sp., Boscia senegalenis, Acacia tortilis, Tribulis terristris, Boscia angustifolia, Bicoma tomentosa, Blepharis linarifolia and Aristida funiculata during lean periods to meet their food requirements. The formulation of the feed ration for animals differs from one area to another. It is mainly based on residues from cereals such as millet (Panicum miliaceum) and sorghum (Sorghum bicolor).
文摘This study is being carried out in the cross-border area of </span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">the tri-national Dja-Odzala-Minkébé (TRIDOM), subject of a cooperation agreement between Cameroon, Congo a</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">nd Gabon in 2005. The purpose of this study is to analyze the dynamics of changes in land use in the context of cross-border cooperation. Geographic information systems and remote sensing were used to produce the various land use maps. For this purpose, the MERIS satellite images for the periods 1992, 2005 and 2018 were used. The exploration of the different images and the field visits made it possible to identify the following six land use classes: dense forests, degraded/deforested forests, savannas, swamp forests, buildings and bare soils, water surfaces. It emerges that the TRIDOM landscape is mainly occupied by dense forests which represent 97.02%, 96.72% and 96.52% respectively in 1992, 2005 and 2018. Then, degraded/deforested forests and savannas which would correspond to cultivation areas and fallow land only represent respectively 1.06% and 0.68% of the landscape in 1992. This proportion in 2005 is respectively 1.22% and 0.77%, whereas in 2018, it is respectively 1.36% and 0.81% of the massif. The landscape of TRIDOM has not experienced any significant land use change during the period after the signing of the cooperation agreement. Historical rates of deforestation are low during the period under study. They are estimated at 0.042% and 0.030% respectively for the period 1992-2005 and the period 2005-2018. These low rates of deforestation seem to be due to the measures taken to secure and sustainably manage the massif taken by the three countries, the low population density in this area and the still difficult level of accessibility of a large part of the massif.
文摘The eastern and southern regions of Cameroon, lower middle income country, need to increase their level of land use by the agricultural, forestry and mining sectors in order to develop. At the same time, Cameroon is committed to managing its forests sustainably to meet the needs of present and future generations. This study assesses the compatibility of agricultural, forestry and mining policies with sustainable forest management in the East and South forest regions. Five analytical criteria were used and the analysis was carried out through surveys of key informants in the private sector, public administrations and civil society. The study showed that from 2013 to 2018, the contributions of the agricultural, forestry and mining sectors to GDP grew by about 74%, 65% and 60%, respectively. Agricultural, forestry and mining policies have an average compatibility rate of 45% with sustainable forest management, of which 52% for the forestry sector, 43% for the agricultural sector and 40% for the mining sector. Nonetheless, there are 21 causes of incompatibility, including 1) the non-involvement of all relevant public administrations in policy-making, 2) the low efficiency of the control system of exploitation activities, and 3) the poor coordination of actions in the three sectors. It was proposed to a) improve the legal and regulatory framework of the three sectors of activity and b) develop land-use planning tools among other measures to align existing policies with sustainable forest management.
文摘Holistic integrative medicine,abbreviated as HIM,has been officially proposed since 2012.Its theoretical system has been continuously improved,and its practical methods have become increasingly diverse,becoming an inevitable choice and path for the medical development in the new era.This article demonstrates ten major propositions for HIM,elaborating on the connotation and extension of HIM from the perspectives of epistemology and methodology,in order to achieve the transformation and adaptive evolution of modernmedicine.
基金funded by the National Natu-ral Science Foundation of China(Grant No.42075044 and No.41975112)a project supported by the Innovation Group Project of the Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(Grant No.311022006).
文摘This study quantified the regional damages resulting from temperature and sea level changes using the Regional Integrated of Climate and Economy(RICE)model,as well as the effects of enabling and disabling the climate impact module on future emission pathways.Results highlight varied damages depending on regional economic development and locations.Specifically,China and Africa could suffer the most serious comprehensive damages caused by temperature change and sea level rise,followed by India,other developing Asian countries(OthAsia),and other high-income countries(OHI).The comprehensive damage fractions for China and Africa are projected to be 15.1%and 12.5%of gross domestic product(GDP)in 2195,with corresponding cumulative damages of 124.0 trillion and 87.3 trillion United States dollars(USD)from 2005 to 2195,respectively.Meanwhile,the comprehensive damage fractions in Japan,Eurasia,and Russia are smaller and projected to be lower than 5.6%of GDP in 2195,with cumulative damages of 6.8 trillion,4.2 trillion,and 3.3 trillion USD,respectively.Additionally,coastal regions like Africa,the European Union(EU),and OHI show comparable damages for sea level rise and temperature change.In China,however,sea level-induced damages are projected to exceed those from temperature changes.Moreover,this study indicates that switching the damage modules on or off affects the regional and global emission trajectories,but the magnitude is relatively small.By 2195,global emissions under the experiments with all of the damage modules switched off,only the sea level damage module switched on,and only the temperature damage module switched on,were 3.5%,2.3%and 1.2%higher than those with all of the damage modules switched on,respectively.
文摘Holistic integrative medicine,abbreviated as HIM,has been officially proposed since 2012.Its theoretical system has been continuously improved,and its practical methods have become increasingly diverse,becoming an inevitable choice and path for the medical development in the new era.This article demonstrates ten major propositions for HIM,elaborating on the connotation and extension of HIM fromthe perspectives of epistemology and methodology,in order to achieve the transformation and adaptive evolution of modern medicine.
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.
基金supported by the Natural Science Foundation of China(Grant No.41401111)the Independent Research Project of LREIS(CAS)the Shandong Agricultural Science and Technology Fund Project(Grant No.2019LY006)。
文摘The mass elevation effect(MEE)of the Tibetan Plateau(TP)has attracted the attention of geographers because of its significant influence on the Asian climate,snow line,timberline,and other important climate-ecological boundaries of the plateau and on global ecological patterns.In recent years,much progress has been made in quantifying the MEE of TP.However,factors that affect the size of MEE have not been examined in depth,and the key factors still remain unclear.Based on quantification of MEE for each mountain basal elevation plot,this study identifies the factors that contribute significantly to MEE of the plateau.Seven factors are considered,including mountain basal elevation,distance from the core zone of MEE,thermal continentality,maximum elevation,height difference,area,and difference of underlying surface(with the yearly max"Normalized Difference Vegetation Index"(NDVI)serving as a quantitative indicator).We also used these seven factors as independent variables to develop a multiple linear regression model for MEE of the plateau.Results show that:(1)the determination coefficient(R2)of the model reaches as high as 0.877,and the contributions of mountain basal elevation,distance from the core zone of MEE,thermal continentality,maximum elevation,topographical height difference,area,and NDVI are 39.77%,23.02%,14.48%,5.78%,11.41%,2.92%,and 2.62%,respectively,with mountain basal elevation and the distance from the core of MEE as the most important factors;(2)thermal continentality and MEE are significantly correlated,and maximum elevation only has a coupling relationship with MEE,with height difference and NDVI contributing little to MEE.This study deepens our understanding of MEE and its forming factors in the Tibetan Plateau.
文摘In operations management, the learning curve has been an effective tool in estimating operator performance. However, discontinuities in work disrupt the learning process and a phenomenon called remission or forgetting occurs, resulting in increased time of performing the task upon resumption of work. The study aims to identify variables that significantly affect the remission rate of sewing operations in a manufacturing setting. Four variables--length of stint 1, percent Differenceat stint t, gender, and product family, were identified. Statistical analyses, such as paired t-test, correlation, regression, and analysis of variance （ANOVA） were conducted in order to observe the relationships between the dependent variable and independent variables. For the results of the first general regression, gender was found to be an insignificant variable in predicting remission rate, while product family, length of stint 1, and percent Differenceat stint I were statistically significant. Moreover, the final general regression, which excluded the insignificant gender variable and considered the （regrouped） product families, revealed that product family, length of stint 1, and percent Differenceat stint 1 were still statistically significant. Length of stint 1 had a moderately positive correlation with remission rate, while percent Differenceat stint i had a moderately negative correlation with remission rate. Also, percent Differenceat stint 1 was the largest contributor to the remission rate model. In terms of R2, the goodness-of-fit of the model is moderate. Finally, the model yielded an absolute error of 5.08%, indicating a high accuracy in predicting remission rate.
文摘This study provides a harmonization framework for common capital flight policies in Africa.It builds on evidence of persistent extreme poverty in the continent to assess how common measures can be adopted by sampled countries on one cause of extreme poverty:capital flight.The dataset is sub-divided into fundamental characteristics of African capital flight based on income levels,legal foundations,natural resources,political stability,regional proximity,and religious domination.The main finding shows that from a projection date of 2010,a feasible timeframe for harmonizing policies is between 2016 and 2023.This timeframe coincides with the beginning of the post-2015 agenda on sustainable development goals.
基金financially supported by Brazilian Agricultural Research Corporation (Embrapa)-Coordination for the Improvement of Higher Education PersonnelNational Council for Scientific and Technological Development, Federal District Research Support FoundationFoundation for Scientific and Technological Development of Mato Grosso do Sul State
文摘Rice genes OsDjA2 and OsERF104,encoding a chaperone protein and an APETELA2/ethylene-responsive factor,respectively,are strongly induced in a compatible interaction with blast fungus,and also have function in plant susceptibility validated through gene silencing.Here,we reported the CRISPR/Cas9 knockout of OsDjA2 and OsERF104 genes resulting in considerable improvement of blast resistance.A total of 15 OsDjA2(62.5%)and 17 OsERF104(70.8%)T_(0)transformed lines were identified from 24 regenerated plants for each target and used in downstream experiments.Phenotyping of homozygous T1 mutant lines revealed not only a significant decrease in the number of blast lesions but also a reduction in the percentage of diseased leaf area,compared with the infected control plants.Our results supported CRISPR/Cas9-mediated target mutation in rice susceptibility genes as a potential and alternative breeding strategy for building resistance to blast disease.
