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Reducing Efficiencies of the Commonly Used Heat Treatment Methods and Fermentation Processes on Aflatoxin M1 in Naturally Contaminated Fresh Cow Milk 被引量:1
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作者 G. K. Omeiza M. Mwanza +3 位作者 S. I. Enem E. Godwin M. A. Adeiza C. Okoli 《Open Journal of Veterinary Medicine》 2018年第8期134-145,共12页
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
关键词 FRESH MILK AFLATOXIN M1 Heat Treatment FERMENTATION Processes NIGERIA
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A Synthesizing Land-cover Classification Method Based on Google Earth Engine: A Case Study in Nzhelele and Levhuvu Catchments, South Africa 被引量:5
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作者 ZENG Hongwei WU Bingfang +5 位作者 WANG Shuai MUSAKWA Walter TIAN Fuyou MASHIMBYE Zama Eric POONA Nitesh SYNDEY Mavengahama 《Chinese Geographical Science》 SCIE CSCD 2020年第3期397-409,共13页
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
关键词 land-cover classification random forest percentile composite Landsat 8 Sentinel-1 Google Earth Engine(GEE)
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Simulating Phenology,Growth and Yield of Transplanted Rice at Different Seedling Ages in Northern Iran Using ORYZA2000 被引量:5
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作者 B.Amiri LARIJANI Z.T.SARVESTANI +2 位作者 Gh.NEMATZADEH A.M.MANSCHADI E.AMIRI 《Rice science》 SCIE 2011年第4期321-334,共14页
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
关键词 RICE crop model ORYZA2000 PHENOLOGY seedling age
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The Role of Biodiversity in Food Security and Nutrition: A Potato Cultivar Case Study 被引量:1
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作者 Carmen van Niekerk Hettie Schönfeldt +1 位作者 Nicolette Hall Beulah Pretorius 《Food and Nutrition Sciences》 2016年第5期371-382,共12页
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
关键词 POTATOES Solanum tuberosum Nutrient Content BIODIVERSITY Sub-Saharan Food and Nutrition Security
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Barley and Wheat Share the Same Gene Controlling the Short Basic Vegetative Period 被引量:1
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作者 Lü Rui-hua XU Yan-hao +5 位作者 Rodger Boyd ZHANG Xiao-qi Sue Broughton Michael Jones LI Cheng-dao CHEN Yao-feng 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2013年第10期1703-1711,共9页
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
关键词 basic vegetative period candidate genes Hordeum Triticum
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Fractional Analysis of Viscous Fluid Flow with Heat and Mass Transfer Over a Flexible Rotating Disk
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作者 Muhammad Shuaib Muhammad Bilal +1 位作者 Muhammad Altaf Khan Sharaf J.Malebary 《Computer Modeling in Engineering & Sciences》 SCIE EI 2020年第4期377-400,共24页
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
关键词 Caputo derivatives similarity transformation RK4 soret effect Dufour effect
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Assessing Secure OpenID-Based EAAA Protocol to Prevent MITM and Phishing Attacks in Web Apps
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作者 Muhammad Bilal Sandile C.Showngwe +1 位作者 Abid Bashir Yazeed Y.Ghadi 《Computers, Materials & Continua》 SCIE EI 2023年第6期4713-4733,共21页
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
关键词 SECURE user authentication SSO OPENID phishing attack MITM attack
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Prioritised identification of structural classes of natural products from higher plants in the expedition of antimalarial drug discovery
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作者 Phanankosi Moyo Luke Invernizzi +5 位作者 Sephora M.Mianda Wiehan Rudolph Andrew W.Andayi Mingxun Wang Neil R.Crouch Vinesh J.Maharaj 《Natural Products and Bioprospecting》 CSCD 2023年第1期348-367,共20页
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
关键词 Natural products Compound classes PHYTOCHEMICALS Plasmodium falciparum Antiplasmodial drug resistance MALARIA Drug development
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Influences of various grazing systems on community biomass of a desert grassland in Inner Mongolia,China
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作者 RuiRui Yan XiaoPing Xin +3 位作者 ZhiJun Wei ShiMin Liu Jing Yang GuiXia Yang 《Research in Cold and Arid Regions》 2012年第4期303-309,共7页
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
关键词 continuous grazing rotational grazing aboveground biomass belowground biomass Stipa breviJlora Griseb
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Data Regarding Qualitative and Quantitative Composition of Benthic Populations from Musura Bay-Danube Delta, Romania
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作者 Manuela Diana Samargiu Daciana Sava +1 位作者 Dorel Ureche Gabriela Mihaela Pamschiv 《Journal of Environmental Science and Engineering(B)》 2015年第11期569-573,共5页
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
关键词 Black sea Danube delta Musura bay zoobenthos.
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Biodiversity and Distribution of Aspergillus and Their Toxins in Maize from Western and Eastern Regions of South Africa
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作者 Ngum Queenta Nji Adetunji Modupeade Christianah +1 位作者 Ateba Collins Njie Mwanza Mulunda 《Advances in Microbiology》 2022年第3期121-149,共29页
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
关键词 Aspergillus Species AFLATOXINS MAIZE Aflatoxicity Agro-Climatic South Africa
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Assessing the Impacts of Summer Range on Bathurst Caribou’s Productivity and Abundance since 1985
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作者 Wenjun Chen Lori White +7 位作者 Jan Z. Adamczewski Bruno Croft Kerri Garner Jody S. Pellissey Karin Clark Ian Olthof Rasim Latifovic Greg L. Finstad 《Natural Resources》 2014年第4期130-145,共16页
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
关键词 Barren Ground CARIBOU Late-Winter Calf:Cow Ratio SUMMER RANGE Leaf Biomass PHENOLOGY Remote Sensing
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Use of the Biostimulant Based on the Mycorrhizae Consortium of the Glomeraceae Family in the Field to Improve the Production and Nutritional Status of Maize (Zea mays L.) Plants in Central Benin
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作者 Corentin Akpodé Sylvestre Abado Assogba +6 位作者 Sêmassa Mohamed Ismaël Hoteyi Mèvognon Ricardos Aguégué Nadège Adoukè Agbodjato Marcel Yévèdo Adoko Olaréwadjou Amogou Adolphe Adjanohoun Lamine Baba-Moussa 《Advances in Microbiology》 2023年第6期323-345,共23页
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
关键词 Ecological Resilience MICROORGANISM Plant Nutrition Sustainable Agriculture Zea mays L.
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A machine learning approach to formation of earthquake categories using hierarchies of magnitude and consequence to guide emergency management
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作者 Donald Douglas Atsa’am Terlumun Gbaden Ruth Wario 《Data Science and Management》 2023年第4期208-213,共6页
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
关键词 Earthquake categories Magnitude and consequence Earthquake classification Resource allocation K-means clustering
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五指山常见热带树种的丛枝菌根真菌多样性(英文) 被引量:10
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作者 石兆勇 王发园 陈应龙 《生态学报》 CAS CSCD 北大核心 2007年第7期2896-2903,共8页
采用野外调查的方法,分析了五指山不同海拔高度7个科10种常见热带树种形成丛枝菌根(Arbuscular Mycorrhizal,AM)的状况及其根际土壤中AM真菌的多样性。结果表明,所调查的10种热带常见树种都能形成AM共生体,其菌根侵染率随寄主植物的不同... 采用野外调查的方法,分析了五指山不同海拔高度7个科10种常见热带树种形成丛枝菌根(Arbuscular Mycorrhizal,AM)的状况及其根际土壤中AM真菌的多样性。结果表明,所调查的10种热带常见树种都能形成AM共生体,其菌根侵染率随寄主植物的不同,从21.8%~90.5%变化不等,同时,在10种常见植物的根系中也都观察到了AM真菌的典型结构——丛枝和泡囊。从10种植物的根际土壤中共分离到36种AM真菌,隶属于Acaulospora,Glomus,Gigaspora和Scutellospora4个属,其中,Glomus属的真菌是该地区的优势类群,其出现频度和相对多度分别为84%和56%。在所调查的10种热带常见树种中,Swietenia macrophylla根际AM真菌的孢子最丰富,密度高达7.32;Machilus namu根际的AM真菌种类则最为丰富,多样性指数达到1.6548。通过对不同海拔高度Swietenia macrophylla根际AM真菌分布的分析表明,海拔高度显著影响着AM真菌的分布,Gigaspora属的真菌随海拔高度的增加显著升高,Scutellospora属的真菌则显著降低。 展开更多
关键词 丛枝菌根真菌 多样性 热带雨林 五指山 海拔高度
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Modeling the Dynamics of Tuberculosis with Vaccination,Treatment,and Environmental Impact:Fractional Order Modeling
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作者 Muhammad Altaf Khan Mahmoud H.DarAssi +2 位作者 Irfan Ahmad Noha Mohammad Seyam Ebraheem Alzahrani 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第11期1365-1394,共30页
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
关键词 Tuberculosis real data stability analysis parameter estimations discussion
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Electrochemical properties of MXenes and applications
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作者 Mawethu Pascoe Bilibana 《Advanced Sensor and Energy Materials》 2023年第4期13-39,共27页
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
关键词 Mxene Elctrochemical Biosensor Aptasensor Battery MXene-based energy storage
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具有多层带隙结构的半导体pin结光谱探测性能的研究
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作者 李青 Omolola E.Fayemi +3 位作者 徐俊 吴琨 周建明 雷威 《光电子技术》 CAS 2023年第3期191-197,共7页
深入研究了宽谱入射光的吸收、光生载流子产生,以及光生载流子的输运和复合的物理过程,提出在pin半导体结中设置若干不同能量带隙的半导体层。通过这些不同能量带隙半导体层调节不同波长入射光的吸收区域,并利用偏置电压控制不同区域光... 深入研究了宽谱入射光的吸收、光生载流子产生,以及光生载流子的输运和复合的物理过程,提出在pin半导体结中设置若干不同能量带隙的半导体层。通过这些不同能量带隙半导体层调节不同波长入射光的吸收区域,并利用偏置电压控制不同区域光生载流子的传输和复合,进而改变探测器的光谱响应特性。根据研究结果,如果设置4层带隙梯度分布的本征层,不同偏置电压下探测器光谱响应曲线的Pearson相关系数从0.99下降到0.68,为后续的探测器光谱重构提供了有效的宽谱探测数据。 展开更多
关键词 波分复用算法 光谱重构 非线性相关 能量带隙
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Classification of Chinese Wintersweet (Chimonanthus praecox) Cultivars Supported by Pollen Morphology 被引量:5
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作者 FAN Li-kun LU Ying-min +1 位作者 YAN Gui-jun ZHANG Qi-xiang 《Agricultural Sciences in China》 CSCD 2010年第7期958-964,共7页
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
关键词 wintersweet cultivars pollen-morphological characteristics CLASSIFICATION
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The rhizosphere microbial complex in plant health:A review of interaction dynamics 被引量:1
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作者 Oluwaseyi Samuel OLANREWAJU Olubukola Oluranti BABALOLA 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2022年第8期2168-2182,共15页
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
关键词 below-ground interactions climate change plant growth promotion plant microbiome root exudation
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