The reducing efficiencies of the commonly used heat treatment methods and fermentation processes on aflatoxin M1 (AFM1) in Nigeria were investigated. Seventy samples of fresh cow milk from both conventional and tradit...The reducing efficiencies of the commonly used heat treatment methods and fermentation processes on aflatoxin M1 (AFM1) in Nigeria were investigated. Seventy samples of fresh cow milk from both conventional and traditional dairy cattle herds were collected and analyzed for the determination of AFM1 using Cobra-cell incorporated high performance liquid chromatography. Of these analyzed samples, 56 (80.0%) tested positive for AFM1 out of which 3 milk samples with high AFM1 concentrations were selectively pooled and subjected to varied conditions of heat treatments and fermentation processes using both indigenized and exotic strains of lactic acid bacteria (Lactobacillus bulgaricus + Streptococcus thermophilus and L. rhamnosus and L. plantarum) as starter cultures respectively. Both processes used either singly or combined, demonstrated high degrees of reducing effects on AFM1 levels. Sterilization of the milk at 121?C and 80?C under the same condition of time (15 - 20) min showed significant reduction of up to 58.8% (p 0.05) in the level of AFM1 when compared with the initial mean AFM1 concentration of the untreated fresh milk. The situation was however different around the boiling temperature of 100?C at which point the level of AFM1 reduction was found to be inconsistent. The indigenized combined strains showed some slight margins of AFM1 reduction in the proportions of (20.5, 30.8 and 43.9)% over and above that of the exotic strains (17.4, 30.0 and 41.1)% in 12 h, 48 h and 72 h of fermentation respectively. Generally, fermentation alone showed lower reduction of AFM1 in milk from 24.5% to 43.9% compared with the reducing activities of (35.4 to 58.8)% when heat-treated milk samples were subsequently subjected to varied fermentation conditions.展开更多
This study designed an approach to derive land-cover in the South Africa with insufficient ground samples, and made a case demonstration in Nzhelele and Levhuvu catchments, South Africa. The method was developed based...This study designed an approach to derive land-cover in the South Africa with insufficient ground samples, and made a case demonstration in Nzhelele and Levhuvu catchments, South Africa. The method was developed based on an integration of Landsat 8, Sentinel-1, and Shuttle Radar Topography Mission(SRTM) Digital Elevation Model(DEM), and the Google Earth Engine(GEE) platform. Random forest classifier with 300 trees is employed as land-cover classification model. In order to overcome the defect of insufficient ground data, the stratified sampling method was used to generate the training and validation samples from the existing land-cover product. Likewise, in order to recognize different land-cover categories, the percentile and monthly median composites were employed to expand input metrics of random forest classifier. Results showed that the overall accuracy of the land-cover of Nzhelele and Levhuvu catchments, South Africa in 2017–2018 reached to 76.43%. Three important results can be drawn from our research. 1) The participation of Sentinel-1 data can slightly improve overall accuracy of land-cover while its contribution on land-cover classification varied with land types. 2) Under-fitting problem was observed in the training of non-dominant land-cover categories using the random sampling, the stratified sampling method is recommended to make sure the classification accuracy of non-dominant classes. 3) When related reflectance bands participated in the training process, individual Normalized Difference Vegetation index(NDVI), Enhanced Vegetation Index(EVI), Soil Adjusted Vegetation Index(SAVI), Normalized Difference Built-up Index(NDBI) have little effect on final land-cover classification result.展开更多
Rice crop growth and yield in the north Iran are affected by crop duration and phenology.The purpose of this study was to calibrate and validate the ORYZA2000 model under potential production based on experimental dat...Rice crop growth and yield in the north Iran are affected by crop duration and phenology.The purpose of this study was to calibrate and validate the ORYZA2000 model under potential production based on experimental data for simulating and quantifying the phenological development,crop duration and yield prediction of rice crop influenced by different seedling ages.In order to calibrate and validate the crop parameters of ORYZA2000 model,a two-year field experiment was conducted under potential growth condition for transplanted lowland rice during the 2008-2009 rice growing seasons,using three rice varieties with three seedling ages(17,24 and 33 days old).The results showed that the seedling age changed crop duration from 7 to 10 d.The ORYZA2000 model could predict well,but consistently underestimated the length of growing period.The range in normalized root mean square error(RMSEn) values for each phenological stage was between 4% and 6%.From our evaluation,we concluded that ORYZA2000 was sufficiently accurate in simulation of yield,leaf area index(LAI) and biomass of crop organs over time.On average,RMSEn values were 13%-15% for total biomass,18%-21% for green leaf biomass,17%-20% for stem biomass,16%-23% for panicle biomass and 24%-26% for LAI.The RMSEn values for final yield and biomass were 12%-16% and 6%-9%,respectively.Generally,the model simulated LAI,an exceeded measured value for younger seedlings,and best-fit was observed for older seedlings of short-duration varieties.The results revealed that the ORYZA2000 model can be applied as a supportive research tool for selecting the most appropriate strategies for rice yield improvement across the north Iran.展开更多
Biodiversity is considered a critical measure of the agricultural health of the world. Not only does increased biodiversity contribute to nutrient production and consumption, but it acts as a safeguard against food sh...Biodiversity is considered a critical measure of the agricultural health of the world. Not only does increased biodiversity contribute to nutrient production and consumption, but it acts as a safeguard against food shortages due to pests and diseases by spreading the risk. Biodiversity can improve dietary diversity in such a way to ultimately contribute to improved food and nutrition security. As a result biodiversity is often highlighted in global discussions related to food and nutrition security. Potatoes (Solanum tuberosum L.) are highly biodiverse food crops, with more than 4000 different cultivars grown globally. The crop is sometimes considered as part of the vegetable component of food baskets, but it is mainly added to meals as a starch because potatoes have a high starch content and are thus high in energy. However, significant differences in the nutritional content (including micronutrient composition) of different potato cultivars have been reported in many countries. It is therefore proposed that specific cultivars could potentially contribute more to critical nutrients required in the diet of countries at risk of malnutrition. The nutritional profile (macronutrients and minerals) of 11 potato cultivars cultivated in sub-Saharan Africa was determined and the contribution which these different potatoes could make to the diet, and consequently to food and nutrition security, is discussed. The results showed that significant differences are found in the nutritional content between the different cultivars. Significant differences (p < 0.001) were found in macronutrients such as protein and fat as well as micronutrients such as copper, phosphorus and potassium. These results indicate the potentially beneficial role which a biodiverse range of crops such as potatoes, could play in the food and nutrition security of developing countries.展开更多
Basic vegetative period(BVP) is an important trait for determining flowering time and adaptation to variable environments.A short BVP barley mutant is about 30 d shorter than its wild type.Genetic analysis using 557...Basic vegetative period(BVP) is an important trait for determining flowering time and adaptation to variable environments.A short BVP barley mutant is about 30 d shorter than its wild type.Genetic analysis using 557 F 2 individuals revealed that the short BVP is governed by a single recessive gene(BVP-1) and was further validated in 2 090 F 3 individuals.The BVP-1 gene was first mapped to barley chromosome 1H using SSR markers.Comparative genomic analysis demonstrated that the chromosome region of BVP-1 is syntenic to rice chromosome 5 and Brachypodium chromosome 2.Barley ESTs/genes were identified after comparison with candidate genes in rice and Brachypodium;seven new gene-specific markers were developed and mapped in the mapping populations.The BVP-1 gene co-segregated with the Mot1 and Ftsh4 genes and was flanked by the gene-specific markers AK252360(0.2 cM) and CA608558(0.5 cM).Further analysis demonstrated that barley and wheat share the same short BVP gene controlling early flowering.展开更多
An unsteady viscous fluid flow with Dufour and Soret effect,which results in heat and mass transfer due to upward and downward motion of flexible rotating disk,has been studied.The upward or downward motion of non rot...An unsteady viscous fluid flow with Dufour and Soret effect,which results in heat and mass transfer due to upward and downward motion of flexible rotating disk,has been studied.The upward or downward motion of non rotating disk results in two dimensional flow,while the vertical action and rotation of the disk results in three dimensional flow.By using an appropriate transformation the governing equations are transformed into the system of ordinary differential equations.The system of ordinary differential equations is further converted into first order differential equation by selecting suitable variables.Then,we generalize the model by using the Caputo derivative.The numerical result for the fractional model is presented and validated with Runge Kutta order 4 method for classical case.The compared results are presented in Table and Figures.It is concluded that the fractional model is more realistic than that of classical one,because it simulates the fluid behavior at each fractional value rather than the integral values.展开更多
To secure web applications from Man-In-The-Middle(MITM)and phishing attacks is a challenging task nowadays.For this purpose,authen-tication protocol plays a vital role in web communication which securely transfers dat...To secure web applications from Man-In-The-Middle(MITM)and phishing attacks is a challenging task nowadays.For this purpose,authen-tication protocol plays a vital role in web communication which securely transfers data from one party to another.This authentication works via OpenID,Kerberos,password authentication protocols,etc.However,there are still some limitations present in the reported security protocols.In this paper,the presented anticipated strategy secures both Web-based attacks by leveraging encoded emails and a novel password form pattern method.The proposed OpenID-based encrypted Email’s Authentication,Authorization,and Accounting(EAAA)protocol ensure security by relying on the email authenticity and a Special Secret Encrypted Alphanumeric String(SSEAS).This string is deployed on both the relying party and the email server,which is unique and trustworthy.The first authentication,OpenID Uniform Resource Locator(URL)identity,is performed on the identity provider side.A second authentication is carried out by the hidden Email’s server side and receives a third authentication link.This Email’s third SSEAS authentication link manages on the relying party(RP).Compared to existing cryptographic single sign-on protocols,the EAAA protocol ensures that an OpenID URL’s identity is secured from MITM and phishing attacks.This study manages two attacks such as MITM and phishing attacks and gives 339 ms response time which is higher than the already reported methods,such as Single Sign-On(SSO)and OpenID.The experimental sites were examined by 72 information technology(IT)specialists,who found that 88.89%of respondents successfully validated the user authorization provided to them via Email.The proposed EAAA protocol minimizes the higher-level risk of MITM and phishing attacks in an OpenID-based atmosphere.展开更多
The emergence and spread of drug-recalcitrant Plasmodium falciparum parasites threaten to reverse the gains made in the fight against malaria.Urgent measures need to be taken to curb this impending challenge.The highe...The emergence and spread of drug-recalcitrant Plasmodium falciparum parasites threaten to reverse the gains made in the fight against malaria.Urgent measures need to be taken to curb this impending challenge.The higher plant-derived sesquiterpene,quinoline alkaloids,and naphthoquinone natural product classes of compounds have previously served as phenomenal chemical scaffolds from which integral antimalarial drugs were developed.Historical successes serve as an inspiration for the continued investigation of plant-derived natural products compounds in search of novel molecular templates from which new antimalarial drugs could be developed.The aim of this study was to identify potential chemical scaffolds for malaria drug discovery following analysis of historical data on phytochemicals screened in vitro against P.falciparum.To identify these novel scaffolds,we queried an in-house manually curated database of plant-derived natural product compounds and their in vitro biological data.Natural products were assigned to different structural classes using NPClassifier.To identify the most promising chemical scaffolds,we then correlated natural compound class with bioactivity and other data,namely(i)potency,(ii)resistance index,(iii)selectivity index and(iv)physicochemical properties.We used an unbiased scoring system to rank the different natural product classes based on the assessment of their bioactivity data.From this analysis we identified the top-ranked natural product pathway as the alkaloids.The top three ranked super classes identified were(i)pseudoalkaloids,(ii)naphthalenes and(iii)tyrosine alkaloids and the top five ranked classes(i)quassinoids(of super class triterpenoids),(ii)steroidal alkaloids(of super class pseudoalkaloids)(iii)cycloeudesmane sesquiterpenoids(of super class triterpenoids)(iv)isoquinoline alkaloids(of super class tyrosine alkaloids)and(v)naphthoquinones(of super class naphthalenes).Launched chemical space of these identified classes of compounds was,by and large,distinct from that of‘legacy’antimalarial drugs.Our study was able to identify chemical scaffolds with acceptable biological properties that are structurally different from current and previously used antimalarial drugs.These molecules have the potential to be developed into new antimalarial drugs.展开更多
This study investigated the effects of various grazing systems, including continuous grazing, rotational grazing, and no-grazing systems, on the community biomass in the Stipa breviflora Griseb desert grassland during...This study investigated the effects of various grazing systems, including continuous grazing, rotational grazing, and no-grazing systems, on the community biomass in the Stipa breviflora Griseb desert grassland during the grazing seasons in 2005, 2006, and 2007, based on study sites established in 1999. We found that the seasonal dynamics of the aboveground biomass were quite similar among the three treatments, which reached peak values in period from August to September during each study year. The continuous grazing system reduced the aboveground biomass from 2005 to 2007 under drought conditions, and the rotational grazing and no-grazing systems maintained more aboveground biomass than the continuous grazing system did. The belowground biomass declined with the increase of soil depth among the three treatments, and in the surface 20-cm soil layer it accounted for more than 60% of the total biomass. The belowground biomass was found to be highly correlated with soil depth under rotational grazing. The total belowground biomass within the 0--100-cm soil layer for rotational grazing was sig- nificantly higher than for continuous grazing and no-grazing, and had 15,775 kg/ha more biomass. Our results demonstrate that conservative rotational grazing can alleviate grassland deterioration by reserving more aboveground and belowground biomass than the continuous grazing system does.展开更多
The present paper refers to some data regarding zoobenthic communities from one of northern lagoon of the Danube delta, known as Musura bay (ROSCI0065, coded as coastal lagoon * 1150). Faunal composition is influen...The present paper refers to some data regarding zoobenthic communities from one of northern lagoon of the Danube delta, known as Musura bay (ROSCI0065, coded as coastal lagoon * 1150). Faunal composition is influenced by the mixture of waters from the Danube and the marine coastal zone. According to monitored areas, there are dominant freshwater or marine invertebrates forming populations that live in the sediments. The aim of this paper is to offer a view of the endopsammic and endopelitic benthic communities from Musura bay, during two years of observations (2013 and 2014) and analyze the seasonal dynamics of invertebrates' populations. Based on quantitative samples collected from infralittoral zone, the paper presents the qualitative structure and a quantitative analyze (abundance, constancy--F%, dominance--D% and Wo%) of invertebrate populations from all taxa (belonging to Foraminifera, Nematoda, Gasteropoda, Oligochaeta, Polychaeta, Ostracoda, Copepoda, Cumacea, Amphipoda and Chironomidae etc.) found in the researched zones, in connection with variation of local ecological conditions. Some considerations regarding the role of invertebrates' populations as food resources for lagoon fishes are done,展开更多
Aspergillus species and aflatoxins production are more prevalent during times of high heat and drought. In South Africa, there is frequent occurrence of drought as a result of climate change. The aim of this study was...Aspergillus species and aflatoxins production are more prevalent during times of high heat and drought. In South Africa, there is frequent occurrence of drought as a result of climate change. The aim of this study was to investigate the biodiversity and distribution of Aspergillus species with their corresponding toxins in maize from main maize producing regions of South Africa;[Western Regions (WR) and Eastern Regions (ER)]. One hundred and twenty-three (64 from WR and 59 from ER) maize samples from the two agro-climatic regions in South Africa were analyzed using cultural, molecular and analytical methods. Across agro-climatic regions, Aspergillus species contaminated about 62% of the maize samples, while Aspergillus flavus was the most prevalent (47.15%) followed by Aspergillus fumigatus (4.69%) while the least was Aspergillus parasiticus (0.81%). The Western Regions showed a higher distribution of varieties of Aspergillus species compared to the Eastern Regions. Aflatoxins contaminated only 27.64% of the maize samples with a mean total aflatoxin concentration of 2.40 μg/kg which is below the South Africa’s set standard for total aflatoxin in food (5 μg/kg). About 10.57% of the samples produce aflatoxins above the 5 μg/kg permissible limit for total aflatoxin in foods. The ratio of toxigenic to atoxigenic strains of Aspergillus flavus was generally low in all the regions of South Africa. This study could aid policy makers to make informed decisions in developing remediation strategies for Aspergillus mycotoxins.展开更多
Barren ground caribou are one of the most important natural resources for northern aboriginal peoples in Canada, and their responsible management has been identified as a top priority by northern communities and gover...Barren ground caribou are one of the most important natural resources for northern aboriginal peoples in Canada, and their responsible management has been identified as a top priority by northern communities and governments. This study is aimed to assess the impacts of summer range forage availability and quality on Bathurst caribou’s productivity and abundance. Despite well documented effects of habitat nutrition on individual animal, few studies have been able to link nutrition and population demographics in a quantitative fashion, probably because caribou productivity and abundance could be potentially affected by many factors (e.g., habitat, harvest, predators, diseases/parasites, extreme weather, climate change, industrial development, and pollution), and yet long-term data for many of these factors are not available. By determining the upper envelope curve between summer range indicators and caribou productivity, this study made such assessment possible. Our results indicate that summer range indicators derived from long-term remote sensing time series and climate records can explain 59% of the variation in late-winter calf:cow ratio during 1985 and 2012. As a measure of caribounet productvitiy, the late-winter calf:cow ratio, together with the mortality rate, in turn determined population dynamics.展开更多
Excessive use of mineral fertilizers in maize farming negatively affects farmers’ income and impacts long-term soil health. This study aims to appreciate the effectiveness of biostimulant based on native Glomeraceae ...Excessive use of mineral fertilizers in maize farming negatively affects farmers’ income and impacts long-term soil health. This study aims to appreciate the effectiveness of biostimulant based on native Glomeraceae arbuscular mycorrhizal fungi on the production and uptake of phosphorus, nitrogen and potassium of maize (Zea mays L.) plants in central Benin. The trials were set up in a farming environment with thirty-four producers. The experimental design was composed of three treatments installed at 34 producers. Three growth parameters were evaluated on 60 ème days after sowing. Grain yield, nutritional status of maize plants and mycorrhization parameters were determined at harvest. The results showed that the Glomeraceae + 50% NPK (NPK: azote-phosphore-potassium)_Urea treatment improved the height, the crown diameter and the leaf area by 17.85%, 21.79% and 28.32% compared to the absolute control and by 0.41%, 1.11% and 1.46% compared to the 100% NPK_Urea treatment, respectively. Similarly, grain yield improved by 45.87% with the use of Glomeraceae + 50% NPK_Urea compared to the absolute control and by 3.96% compared to the 100% NPK_Urea treatment. The Glomeraceae + 50% NPK_Urea significantly improved the phosphorus and potassium uptake of maize plants. With respect to nitrogen uptake, no statistical difference was observed between treatments. The mycorrhizae strains used improved root infection in the maize plants. We recorded 66% frequency and 40.5% intensity of mycorrhization. The biostimulant based on indigenous Glomeraceae combined with 50% NPK_Urea can be used as a strategy to restore soil health and improve maize productivity in Benin.展开更多
This study deployed k-means clustering to formulate earthquake categories based on magnitude and consequence,using global earthquake data spanning from 1900 to 2021.Based on patterns within the historical data,numeric...This study deployed k-means clustering to formulate earthquake categories based on magnitude and consequence,using global earthquake data spanning from 1900 to 2021.Based on patterns within the historical data,numeric boundaries were extracted to categorize the magnitude,deaths,injuries,and damage caused by earthquakes into low,medium,and high classes.Following a future earthquake incident,the classification scheme can be utilized to assign earthquakes into appropriate categories by inputting the magnitude,number of fatalities and injuries,and monetary estimates of total damage.The resulting taxonomy provides a means of classifying future earthquake incidents,thereby guiding the allocation and deployment of disaster management resources in proportion to the specific characteristics of each incident.Furthermore,the scheme can serve as a reference tool for auditing the utilization of earthquake management resources.展开更多
A mathematical model is designed to investigate Tuberculosis(TB)disease under the vaccination,treatment,andenvironmental impact with real cases.First,we introduce the model formulation in non-integer order derivativea...A mathematical model is designed to investigate Tuberculosis(TB)disease under the vaccination,treatment,andenvironmental impact with real cases.First,we introduce the model formulation in non-integer order derivativeand then,extend the model into fractional order derivative.The fractional system’s existence,uniqueness,andother relevant properties are shown.Then,we study the stability analysis of the equilibrium points.The disease-free equilibrium(DFE)D_(0)is locally asymptotically stable(LAS)when R_(v)<1.Further,we show the globalasymptotical stability(GAS)of the endemic equilibrium(EE)D*for R_(v)>1 and D_(0)for R_(v)≤1.The existenceof bifurcation analysis in the model is investigated,and it is shown the system possesses the forward bifurcationphenomenon.Sensitivity analysis has been performed to determine the sensitive parameters that impact R_(v).Weconsider the real TB statistics from Khyber Pakhtunkhwa in Pakistan and parameterized the model.The computedbasic reproduction number obtained using the real cases is R0≈3.6615.Various numerical results regardingdisease elimination of the sensitive parameters are shown graphically.展开更多
MXenes,a two-dimensional transition metal carbide,nitride,and carbonitride family,have received a lot of interest in recent years due to their unique properties and diverse applications.This review presents a comprehe...MXenes,a two-dimensional transition metal carbide,nitride,and carbonitride family,have received a lot of interest in recent years due to their unique properties and diverse applications.This review presents a comprehensive analysis of the applications and electrochemical characteristics of MXenes,providing a nuanced viewpoint on their potential impact in variousfields.MXenes have a large surface area,high electrical conductivity,and variable surface chemistry,making them appealing candidates for energy storage,catalysis,sensing,and electronic device applications.The electrochemical characteristics of MXenes are fully investigated,including charge storage capacity and ion diffusion kinetics,highlighting their usefulness for supercapacitors,lithium-ion batteries,and other energy storage devices.Furthermore,this study digs into the interactions of MXenes with various electrolytes,offering insight into the obstacles and potential related to their practical application.The review also discusses the strategies employed to modify MXene properties and enhance their performance in surface chemistries across various energy storage devices and bio/sensor and clarify the correlations between their electrochemical properties and the required functions.Ultimately,this work provides a comprehensive outlook on the current state of MXene research,emphasizing the potentially transformative role of these materials in advancing technology across various domains.展开更多
To classify the Chinese wintersweet(Chimonanthus praecox) cultivars and to study their evolution based on pollen morphology.Pollens of 12 representative wintersweet cultivars were examined by scanning electron micro...To classify the Chinese wintersweet(Chimonanthus praecox) cultivars and to study their evolution based on pollen morphology.Pollens of 12 representative wintersweet cultivars were examined by scanning electron microscopy(SEM).Q-cluster analysis was carried out based on the observation results.Results are as follows:(1) The pollen grains were 2lobed circular in polar view,elliptic in equatorial view.The pollen shapes were spheroidal or super-spheroidal by P/E(polar axis length/equatorial axis length) criteria.(2) According to pollen exine ornamentation,it was indicated that white wintersweet is most original.Yellow floral group could be classified into three subgroups:purple-hearted,halo-hearted and yellow-hearted type.Their evolutionary relationship was purple-hearted halo-hearted yellow-hearted.(3) Different wintersweet cultivars showed a different exine sculpture.Palynological analysis could be used in the classification of wintersweet cultivars.The result of cluster analysis indicated that the cultivars could be classified into three groups with a similarity coefficient of 0.41.Each group had similar pollen exine sculpture.It was found that the palynological classification coincided well with morphological classification.Our results support the suggestion that purple streaks or patches of inner-petals should be served as the first-order criteria in wintersweet classification.展开更多
Climate change,urbanization,and population increase limit food availability.To sustain human existence,there is the need to increase food and agricultural production to mitigate the impact of these factors.Scientists ...Climate change,urbanization,and population increase limit food availability.To sustain human existence,there is the need to increase food and agricultural production to mitigate the impact of these factors.Scientists have been working for years on ways to increase food production.From plant breeding techniques to soil science,scientists have made tremendous progress.The rhizobiome has been proven to be important to crop production,and the impact of the rhizobiome on plant health cannot be overemphasized.Being rich in diverse complex microbial interactions,the rhizosphere has become a major force in recent plant growth promotion studies.The upsurge in next-generation sequencing applications with the various“omics”technologies is helping to unearth information relating to rhizosphere impact on plant growth.Explaining the complex interactions between and across microbial species present in the rhizosphere is important to further enhance our understanding of their mechanistic and mutualistic functions.Knowledge from this can be used in rhizosphere biome engineering for improved plant growth and yield in the face of the various biotic and abiotic challenges.展开更多
文摘The reducing efficiencies of the commonly used heat treatment methods and fermentation processes on aflatoxin M1 (AFM1) in Nigeria were investigated. Seventy samples of fresh cow milk from both conventional and traditional dairy cattle herds were collected and analyzed for the determination of AFM1 using Cobra-cell incorporated high performance liquid chromatography. Of these analyzed samples, 56 (80.0%) tested positive for AFM1 out of which 3 milk samples with high AFM1 concentrations were selectively pooled and subjected to varied conditions of heat treatments and fermentation processes using both indigenized and exotic strains of lactic acid bacteria (Lactobacillus bulgaricus + Streptococcus thermophilus and L. rhamnosus and L. plantarum) as starter cultures respectively. Both processes used either singly or combined, demonstrated high degrees of reducing effects on AFM1 levels. Sterilization of the milk at 121?C and 80?C under the same condition of time (15 - 20) min showed significant reduction of up to 58.8% (p 0.05) in the level of AFM1 when compared with the initial mean AFM1 concentration of the untreated fresh milk. The situation was however different around the boiling temperature of 100?C at which point the level of AFM1 reduction was found to be inconsistent. The indigenized combined strains showed some slight margins of AFM1 reduction in the proportions of (20.5, 30.8 and 43.9)% over and above that of the exotic strains (17.4, 30.0 and 41.1)% in 12 h, 48 h and 72 h of fermentation respectively. Generally, fermentation alone showed lower reduction of AFM1 in milk from 24.5% to 43.9% compared with the reducing activities of (35.4 to 58.8)% when heat-treated milk samples were subsequently subjected to varied fermentation conditions.
基金Under the auspices of National Natural Science Foundation of China(No.4171101213,41561144013,41991232)National Key R&D Program of China(No.2016YFC0503401,2016YFA0600304)International Partnership Program of Chinese Academy of Sciences(No.121311KYSB20170004)。
文摘This study designed an approach to derive land-cover in the South Africa with insufficient ground samples, and made a case demonstration in Nzhelele and Levhuvu catchments, South Africa. The method was developed based on an integration of Landsat 8, Sentinel-1, and Shuttle Radar Topography Mission(SRTM) Digital Elevation Model(DEM), and the Google Earth Engine(GEE) platform. Random forest classifier with 300 trees is employed as land-cover classification model. In order to overcome the defect of insufficient ground data, the stratified sampling method was used to generate the training and validation samples from the existing land-cover product. Likewise, in order to recognize different land-cover categories, the percentile and monthly median composites were employed to expand input metrics of random forest classifier. Results showed that the overall accuracy of the land-cover of Nzhelele and Levhuvu catchments, South Africa in 2017–2018 reached to 76.43%. Three important results can be drawn from our research. 1) The participation of Sentinel-1 data can slightly improve overall accuracy of land-cover while its contribution on land-cover classification varied with land types. 2) Under-fitting problem was observed in the training of non-dominant land-cover categories using the random sampling, the stratified sampling method is recommended to make sure the classification accuracy of non-dominant classes. 3) When related reflectance bands participated in the training process, individual Normalized Difference Vegetation index(NDVI), Enhanced Vegetation Index(EVI), Soil Adjusted Vegetation Index(SAVI), Normalized Difference Built-up Index(NDBI) have little effect on final land-cover classification result.
基金supported by HARAZ-Extension and Technology Development Center (HETDC) in Amol City,Iran
文摘Rice crop growth and yield in the north Iran are affected by crop duration and phenology.The purpose of this study was to calibrate and validate the ORYZA2000 model under potential production based on experimental data for simulating and quantifying the phenological development,crop duration and yield prediction of rice crop influenced by different seedling ages.In order to calibrate and validate the crop parameters of ORYZA2000 model,a two-year field experiment was conducted under potential growth condition for transplanted lowland rice during the 2008-2009 rice growing seasons,using three rice varieties with three seedling ages(17,24 and 33 days old).The results showed that the seedling age changed crop duration from 7 to 10 d.The ORYZA2000 model could predict well,but consistently underestimated the length of growing period.The range in normalized root mean square error(RMSEn) values for each phenological stage was between 4% and 6%.From our evaluation,we concluded that ORYZA2000 was sufficiently accurate in simulation of yield,leaf area index(LAI) and biomass of crop organs over time.On average,RMSEn values were 13%-15% for total biomass,18%-21% for green leaf biomass,17%-20% for stem biomass,16%-23% for panicle biomass and 24%-26% for LAI.The RMSEn values for final yield and biomass were 12%-16% and 6%-9%,respectively.Generally,the model simulated LAI,an exceeded measured value for younger seedlings,and best-fit was observed for older seedlings of short-duration varieties.The results revealed that the ORYZA2000 model can be applied as a supportive research tool for selecting the most appropriate strategies for rice yield improvement across the north Iran.
文摘Biodiversity is considered a critical measure of the agricultural health of the world. Not only does increased biodiversity contribute to nutrient production and consumption, but it acts as a safeguard against food shortages due to pests and diseases by spreading the risk. Biodiversity can improve dietary diversity in such a way to ultimately contribute to improved food and nutrition security. As a result biodiversity is often highlighted in global discussions related to food and nutrition security. Potatoes (Solanum tuberosum L.) are highly biodiverse food crops, with more than 4000 different cultivars grown globally. The crop is sometimes considered as part of the vegetable component of food baskets, but it is mainly added to meals as a starch because potatoes have a high starch content and are thus high in energy. However, significant differences in the nutritional content (including micronutrient composition) of different potato cultivars have been reported in many countries. It is therefore proposed that specific cultivars could potentially contribute more to critical nutrients required in the diet of countries at risk of malnutrition. The nutritional profile (macronutrients and minerals) of 11 potato cultivars cultivated in sub-Saharan Africa was determined and the contribution which these different potatoes could make to the diet, and consequently to food and nutrition security, is discussed. The results showed that significant differences are found in the nutritional content between the different cultivars. Significant differences (p < 0.001) were found in macronutrients such as protein and fat as well as micronutrients such as copper, phosphorus and potassium. These results indicate the potentially beneficial role which a biodiverse range of crops such as potatoes, could play in the food and nutrition security of developing countries.
基金supported by the Grain Research and Development Cooperation, Australia and the Chinese Scholarship Council
文摘Basic vegetative period(BVP) is an important trait for determining flowering time and adaptation to variable environments.A short BVP barley mutant is about 30 d shorter than its wild type.Genetic analysis using 557 F 2 individuals revealed that the short BVP is governed by a single recessive gene(BVP-1) and was further validated in 2 090 F 3 individuals.The BVP-1 gene was first mapped to barley chromosome 1H using SSR markers.Comparative genomic analysis demonstrated that the chromosome region of BVP-1 is syntenic to rice chromosome 5 and Brachypodium chromosome 2.Barley ESTs/genes were identified after comparison with candidate genes in rice and Brachypodium;seven new gene-specific markers were developed and mapped in the mapping populations.The BVP-1 gene co-segregated with the Mot1 and Ftsh4 genes and was flanked by the gene-specific markers AK252360(0.2 cM) and CA608558(0.5 cM).Further analysis demonstrated that barley and wheat share the same short BVP gene controlling early flowering.
文摘An unsteady viscous fluid flow with Dufour and Soret effect,which results in heat and mass transfer due to upward and downward motion of flexible rotating disk,has been studied.The upward or downward motion of non rotating disk results in two dimensional flow,while the vertical action and rotation of the disk results in three dimensional flow.By using an appropriate transformation the governing equations are transformed into the system of ordinary differential equations.The system of ordinary differential equations is further converted into first order differential equation by selecting suitable variables.Then,we generalize the model by using the Caputo derivative.The numerical result for the fractional model is presented and validated with Runge Kutta order 4 method for classical case.The compared results are presented in Table and Figures.It is concluded that the fractional model is more realistic than that of classical one,because it simulates the fluid behavior at each fractional value rather than the integral values.
文摘To secure web applications from Man-In-The-Middle(MITM)and phishing attacks is a challenging task nowadays.For this purpose,authen-tication protocol plays a vital role in web communication which securely transfers data from one party to another.This authentication works via OpenID,Kerberos,password authentication protocols,etc.However,there are still some limitations present in the reported security protocols.In this paper,the presented anticipated strategy secures both Web-based attacks by leveraging encoded emails and a novel password form pattern method.The proposed OpenID-based encrypted Email’s Authentication,Authorization,and Accounting(EAAA)protocol ensure security by relying on the email authenticity and a Special Secret Encrypted Alphanumeric String(SSEAS).This string is deployed on both the relying party and the email server,which is unique and trustworthy.The first authentication,OpenID Uniform Resource Locator(URL)identity,is performed on the identity provider side.A second authentication is carried out by the hidden Email’s server side and receives a third authentication link.This Email’s third SSEAS authentication link manages on the relying party(RP).Compared to existing cryptographic single sign-on protocols,the EAAA protocol ensures that an OpenID URL’s identity is secured from MITM and phishing attacks.This study manages two attacks such as MITM and phishing attacks and gives 339 ms response time which is higher than the already reported methods,such as Single Sign-On(SSO)and OpenID.The experimental sites were examined by 72 information technology(IT)specialists,who found that 88.89%of respondents successfully validated the user authorization provided to them via Email.The proposed EAAA protocol minimizes the higher-level risk of MITM and phishing attacks in an OpenID-based atmosphere.
文摘The emergence and spread of drug-recalcitrant Plasmodium falciparum parasites threaten to reverse the gains made in the fight against malaria.Urgent measures need to be taken to curb this impending challenge.The higher plant-derived sesquiterpene,quinoline alkaloids,and naphthoquinone natural product classes of compounds have previously served as phenomenal chemical scaffolds from which integral antimalarial drugs were developed.Historical successes serve as an inspiration for the continued investigation of plant-derived natural products compounds in search of novel molecular templates from which new antimalarial drugs could be developed.The aim of this study was to identify potential chemical scaffolds for malaria drug discovery following analysis of historical data on phytochemicals screened in vitro against P.falciparum.To identify these novel scaffolds,we queried an in-house manually curated database of plant-derived natural product compounds and their in vitro biological data.Natural products were assigned to different structural classes using NPClassifier.To identify the most promising chemical scaffolds,we then correlated natural compound class with bioactivity and other data,namely(i)potency,(ii)resistance index,(iii)selectivity index and(iv)physicochemical properties.We used an unbiased scoring system to rank the different natural product classes based on the assessment of their bioactivity data.From this analysis we identified the top-ranked natural product pathway as the alkaloids.The top three ranked super classes identified were(i)pseudoalkaloids,(ii)naphthalenes and(iii)tyrosine alkaloids and the top five ranked classes(i)quassinoids(of super class triterpenoids),(ii)steroidal alkaloids(of super class pseudoalkaloids)(iii)cycloeudesmane sesquiterpenoids(of super class triterpenoids)(iv)isoquinoline alkaloids(of super class tyrosine alkaloids)and(v)naphthoquinones(of super class naphthalenes).Launched chemical space of these identified classes of compounds was,by and large,distinct from that of‘legacy’antimalarial drugs.Our study was able to identify chemical scaffolds with acceptable biological properties that are structurally different from current and previously used antimalarial drugs.These molecules have the potential to be developed into new antimalarial drugs.
基金funded by basic special funding from the central public welfare scientific research institutes (No.202-21)public sector projects in the Ministry of Agriculture(Nos. 201003019,201003061)scientific and technological innovation and incentive funds of Inner Mongolia autonomous region and major state basic research development program of China (973 Program) (2010CB833502)
文摘This study investigated the effects of various grazing systems, including continuous grazing, rotational grazing, and no-grazing systems, on the community biomass in the Stipa breviflora Griseb desert grassland during the grazing seasons in 2005, 2006, and 2007, based on study sites established in 1999. We found that the seasonal dynamics of the aboveground biomass were quite similar among the three treatments, which reached peak values in period from August to September during each study year. The continuous grazing system reduced the aboveground biomass from 2005 to 2007 under drought conditions, and the rotational grazing and no-grazing systems maintained more aboveground biomass than the continuous grazing system did. The belowground biomass declined with the increase of soil depth among the three treatments, and in the surface 20-cm soil layer it accounted for more than 60% of the total biomass. The belowground biomass was found to be highly correlated with soil depth under rotational grazing. The total belowground biomass within the 0--100-cm soil layer for rotational grazing was sig- nificantly higher than for continuous grazing and no-grazing, and had 15,775 kg/ha more biomass. Our results demonstrate that conservative rotational grazing can alleviate grassland deterioration by reserving more aboveground and belowground biomass than the continuous grazing system does.
文摘The present paper refers to some data regarding zoobenthic communities from one of northern lagoon of the Danube delta, known as Musura bay (ROSCI0065, coded as coastal lagoon * 1150). Faunal composition is influenced by the mixture of waters from the Danube and the marine coastal zone. According to monitored areas, there are dominant freshwater or marine invertebrates forming populations that live in the sediments. The aim of this paper is to offer a view of the endopsammic and endopelitic benthic communities from Musura bay, during two years of observations (2013 and 2014) and analyze the seasonal dynamics of invertebrates' populations. Based on quantitative samples collected from infralittoral zone, the paper presents the qualitative structure and a quantitative analyze (abundance, constancy--F%, dominance--D% and Wo%) of invertebrate populations from all taxa (belonging to Foraminifera, Nematoda, Gasteropoda, Oligochaeta, Polychaeta, Ostracoda, Copepoda, Cumacea, Amphipoda and Chironomidae etc.) found in the researched zones, in connection with variation of local ecological conditions. Some considerations regarding the role of invertebrates' populations as food resources for lagoon fishes are done,
文摘Aspergillus species and aflatoxins production are more prevalent during times of high heat and drought. In South Africa, there is frequent occurrence of drought as a result of climate change. The aim of this study was to investigate the biodiversity and distribution of Aspergillus species with their corresponding toxins in maize from main maize producing regions of South Africa;[Western Regions (WR) and Eastern Regions (ER)]. One hundred and twenty-three (64 from WR and 59 from ER) maize samples from the two agro-climatic regions in South Africa were analyzed using cultural, molecular and analytical methods. Across agro-climatic regions, Aspergillus species contaminated about 62% of the maize samples, while Aspergillus flavus was the most prevalent (47.15%) followed by Aspergillus fumigatus (4.69%) while the least was Aspergillus parasiticus (0.81%). The Western Regions showed a higher distribution of varieties of Aspergillus species compared to the Eastern Regions. Aflatoxins contaminated only 27.64% of the maize samples with a mean total aflatoxin concentration of 2.40 μg/kg which is below the South Africa’s set standard for total aflatoxin in food (5 μg/kg). About 10.57% of the samples produce aflatoxins above the 5 μg/kg permissible limit for total aflatoxin in foods. The ratio of toxigenic to atoxigenic strains of Aspergillus flavus was generally low in all the regions of South Africa. This study could aid policy makers to make informed decisions in developing remediation strategies for Aspergillus mycotoxins.
文摘Barren ground caribou are one of the most important natural resources for northern aboriginal peoples in Canada, and their responsible management has been identified as a top priority by northern communities and governments. This study is aimed to assess the impacts of summer range forage availability and quality on Bathurst caribou’s productivity and abundance. Despite well documented effects of habitat nutrition on individual animal, few studies have been able to link nutrition and population demographics in a quantitative fashion, probably because caribou productivity and abundance could be potentially affected by many factors (e.g., habitat, harvest, predators, diseases/parasites, extreme weather, climate change, industrial development, and pollution), and yet long-term data for many of these factors are not available. By determining the upper envelope curve between summer range indicators and caribou productivity, this study made such assessment possible. Our results indicate that summer range indicators derived from long-term remote sensing time series and climate records can explain 59% of the variation in late-winter calf:cow ratio during 1985 and 2012. As a measure of caribounet productvitiy, the late-winter calf:cow ratio, together with the mortality rate, in turn determined population dynamics.
文摘Excessive use of mineral fertilizers in maize farming negatively affects farmers’ income and impacts long-term soil health. This study aims to appreciate the effectiveness of biostimulant based on native Glomeraceae arbuscular mycorrhizal fungi on the production and uptake of phosphorus, nitrogen and potassium of maize (Zea mays L.) plants in central Benin. The trials were set up in a farming environment with thirty-four producers. The experimental design was composed of three treatments installed at 34 producers. Three growth parameters were evaluated on 60 ème days after sowing. Grain yield, nutritional status of maize plants and mycorrhization parameters were determined at harvest. The results showed that the Glomeraceae + 50% NPK (NPK: azote-phosphore-potassium)_Urea treatment improved the height, the crown diameter and the leaf area by 17.85%, 21.79% and 28.32% compared to the absolute control and by 0.41%, 1.11% and 1.46% compared to the 100% NPK_Urea treatment, respectively. Similarly, grain yield improved by 45.87% with the use of Glomeraceae + 50% NPK_Urea compared to the absolute control and by 3.96% compared to the 100% NPK_Urea treatment. The Glomeraceae + 50% NPK_Urea significantly improved the phosphorus and potassium uptake of maize plants. With respect to nitrogen uptake, no statistical difference was observed between treatments. The mycorrhizae strains used improved root infection in the maize plants. We recorded 66% frequency and 40.5% intensity of mycorrhization. The biostimulant based on indigenous Glomeraceae combined with 50% NPK_Urea can be used as a strategy to restore soil health and improve maize productivity in Benin.
文摘This study deployed k-means clustering to formulate earthquake categories based on magnitude and consequence,using global earthquake data spanning from 1900 to 2021.Based on patterns within the historical data,numeric boundaries were extracted to categorize the magnitude,deaths,injuries,and damage caused by earthquakes into low,medium,and high classes.Following a future earthquake incident,the classification scheme can be utilized to assign earthquakes into appropriate categories by inputting the magnitude,number of fatalities and injuries,and monetary estimates of total damage.The resulting taxonomy provides a means of classifying future earthquake incidents,thereby guiding the allocation and deployment of disaster management resources in proportion to the specific characteristics of each incident.Furthermore,the scheme can serve as a reference tool for auditing the utilization of earthquake management resources.
基金supporting this work through the Large Research Group Project under Grant No.R.G.P.2/507/45.
文摘A mathematical model is designed to investigate Tuberculosis(TB)disease under the vaccination,treatment,andenvironmental impact with real cases.First,we introduce the model formulation in non-integer order derivativeand then,extend the model into fractional order derivative.The fractional system’s existence,uniqueness,andother relevant properties are shown.Then,we study the stability analysis of the equilibrium points.The disease-free equilibrium(DFE)D_(0)is locally asymptotically stable(LAS)when R_(v)<1.Further,we show the globalasymptotical stability(GAS)of the endemic equilibrium(EE)D*for R_(v)>1 and D_(0)for R_(v)≤1.The existenceof bifurcation analysis in the model is investigated,and it is shown the system possesses the forward bifurcationphenomenon.Sensitivity analysis has been performed to determine the sensitive parameters that impact R_(v).Weconsider the real TB statistics from Khyber Pakhtunkhwa in Pakistan and parameterized the model.The computedbasic reproduction number obtained using the real cases is R0≈3.6615.Various numerical results regardingdisease elimination of the sensitive parameters are shown graphically.
文摘MXenes,a two-dimensional transition metal carbide,nitride,and carbonitride family,have received a lot of interest in recent years due to their unique properties and diverse applications.This review presents a comprehensive analysis of the applications and electrochemical characteristics of MXenes,providing a nuanced viewpoint on their potential impact in variousfields.MXenes have a large surface area,high electrical conductivity,and variable surface chemistry,making them appealing candidates for energy storage,catalysis,sensing,and electronic device applications.The electrochemical characteristics of MXenes are fully investigated,including charge storage capacity and ion diffusion kinetics,highlighting their usefulness for supercapacitors,lithium-ion batteries,and other energy storage devices.Furthermore,this study digs into the interactions of MXenes with various electrolytes,offering insight into the obstacles and potential related to their practical application.The review also discusses the strategies employed to modify MXene properties and enhance their performance in surface chemistries across various energy storage devices and bio/sensor and clarify the correlations between their electrochemical properties and the required functions.Ultimately,this work provides a comprehensive outlook on the current state of MXene research,emphasizing the potentially transformative role of these materials in advancing technology across various domains.
基金the DUS Project (Guidelines for the Conduct of Tests for Distinctness,Uniformity and Stability for Wintersweet,2006002) for funding assistance
文摘To classify the Chinese wintersweet(Chimonanthus praecox) cultivars and to study their evolution based on pollen morphology.Pollens of 12 representative wintersweet cultivars were examined by scanning electron microscopy(SEM).Q-cluster analysis was carried out based on the observation results.Results are as follows:(1) The pollen grains were 2lobed circular in polar view,elliptic in equatorial view.The pollen shapes were spheroidal or super-spheroidal by P/E(polar axis length/equatorial axis length) criteria.(2) According to pollen exine ornamentation,it was indicated that white wintersweet is most original.Yellow floral group could be classified into three subgroups:purple-hearted,halo-hearted and yellow-hearted type.Their evolutionary relationship was purple-hearted halo-hearted yellow-hearted.(3) Different wintersweet cultivars showed a different exine sculpture.Palynological analysis could be used in the classification of wintersweet cultivars.The result of cluster analysis indicated that the cultivars could be classified into three groups with a similarity coefficient of 0.41.Each group had similar pollen exine sculpture.It was found that the palynological classification coincided well with morphological classification.Our results support the suggestion that purple streaks or patches of inner-petals should be served as the first-order criteria in wintersweet classification.
基金funded by the National Research Foundation(NRF)of South Africa(UID123634 and UID132595)which was granted to Olubukola O.Babalola。
文摘Climate change,urbanization,and population increase limit food availability.To sustain human existence,there is the need to increase food and agricultural production to mitigate the impact of these factors.Scientists have been working for years on ways to increase food production.From plant breeding techniques to soil science,scientists have made tremendous progress.The rhizobiome has been proven to be important to crop production,and the impact of the rhizobiome on plant health cannot be overemphasized.Being rich in diverse complex microbial interactions,the rhizosphere has become a major force in recent plant growth promotion studies.The upsurge in next-generation sequencing applications with the various“omics”technologies is helping to unearth information relating to rhizosphere impact on plant growth.Explaining the complex interactions between and across microbial species present in the rhizosphere is important to further enhance our understanding of their mechanistic and mutualistic functions.Knowledge from this can be used in rhizosphere biome engineering for improved plant growth and yield in the face of the various biotic and abiotic challenges.