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Impact of Nitrogen, Phosphorus and Potassium on Brown Planthopper and Tolerance of Its Host Rice Plants

Rice science 2016年第3期23卷 119-131页

作者： Md Mamunur RASHID Mahbuba JAHAN khandakar shariful islam Plant Physiology Division Bangladesh Rice Research Institute Department of Entomology Bangladesh Agricultural University

The brown planthopper(BPH),Nilaparvata lugens(St?l),appeared as a devastating pest of rice in Asia. Experiments were conducted to study the effects of three nutrients,nitrogen(N),phosphorus(P) and potassium(K),on BPH and its host rice plants. Biochemical constituents of BPH and rice plants with varying nutrient levels at different growth stages,and changes in relative water content(RWC) of rice plants were determined in the laboratory. Feeding of BPH and the tolerance of rice plants to BPH with different nutrient levels were determined in the nethouse. Concentrations of N and P were found much higher in the BPH body than in its host rice plants,and this elemental mismatch is an inherent constraint on meeting nutritional requirements of BPH. Nitrogen was found as a more limiting element for BPH than other nutrients in rice plants. Application of N fertilizers to the rice plants increased the N concentrations both in rice plants and BPH while application of P and K fertilizers increased their concentrations in plant tissues only but not in BPH. Nitrogen application also increased the level of soluble proteins and decreased silicon content in rice plants,which resulted in increased feeding of BPH with sharp reduction of RWC in rice plants ultimately caused susceptible to the pest. P fertilization increased the concentration of P in rice plant tissues but not changed N,K,Si,free sugar and soluble protein contents,which indicated little importance of P to the feeding of BPH and tolerance of plant against BPH. K fertilization increased K content but reduced N,Si,free sugar and soluble protein contents in the plant tissues which resulted in the minimum reduction of RWC in rice plants after BPH feeding,thereby contributed to higher tolerance of rice plants to brown planthopper.

关键词： Nilaparvata lugens relative water content host tolerance nitrogen phosphorus potassium rice nutrient subsidy

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Reduced tillage with residue retention improves soil labile carbon pools and carbon lability and management indices in a seven-year trial with wheat-mung bean-rice rotation

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Pedosphere 2022年第6期32卷 916-927页

作者： Rafeza BEGUM Mohammad M.R.JAHANGIR Mohammad JAHIRUDDIN Mohammad Rafiqul islam Shaikh M.BOKHTIAR khandakar R.islam Department of Soil Science Bangladesh Agricultural UniversityMymensingh 2202(Bangladesh) Soil Resource Development Institute Dhaka 1215(Bangladesh) South Asian Association for Regional Cooperation(SAARC)Agriculture Center Dhaka 1215(Bangladesh) The Ohio State University Columbus OH 43235(USA)

Soil total organic carbon(TOC)is a composite indicator of soil quality with implications for crop production and the regulation of soil ecosystem *** reports on the dynamics of TOC as a consequence of soil management practices in subtropical climatic conditions,where microbial carbon(C)loss is high,are very *** objective of our study was to evaluate the impact of seven years of continuous tillage and residue management on soil TOC dynamics(quantitative and qualitative)with respect to lability and stratification under an annual wheat-mung bean-rice cropping *** soil samples were collected at 0-15 and 15-30 cm depths from a three-replicate split-plot experiment with tillage treatment as the main plots and crop residue levels as the *** tillage treatments included conventional tillage(CT)and strip tillage(ST).Residue levels were high residue level(HR),30%of the plant height,and low residue level(LR),15%.In addition to TOC,soil samples were analyzed for particulate organic C(POC),permanganate oxidizable C(POXC),basal respiration(BR),specific maintenance respiration rate(qCO_(2)),microbial biomass C(MBC),potentially mineralizable C(PMC),and TOC lability and management *** ST treatment significantly increased the TOC and labile C pools at both depths compared with the CT treatment,with the effect being more pronounced in the surface *** HR treatment increased TOC and labile C pools compared with the LR *** ST+HR treatment showed significant increases in MBC,metabolic quotient(qR),C pool index(CPI),C lability index(CL_(I)),and C management index(CMI),indicating improved and efficient soil biological activities in such systems compared with the CT ***,the stratification values,a measure of soil quality improvement,for POC and MBC were>2,indicating improved soil quality in the ST+HR treatment compared with the CT *** ST+HR treatment not only significantly increased the contents o

关键词： basal respiration carbon management index carbon stratification particulate organic carbon permanganate oxidizable carbon total organic carbon

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Ecological fitness of brown planthopper, Nilaparvata lugens (Stål), to rice nutrient management

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Ecological Processes 2017年第1期6卷 149-158页

作者： Md.Mamunur Rashid Mahbuba Jahan khandakar S.islam Md.Abdul Latif Plant Physiology Division Bangladesh Rice Research Institute(BRRI)Gazipur 1701Bangladesh Department of Entomology Bangladesh Agricultural UniversityMymensingh 2202Bangladesh Plant Pathology Division Bangladesh Rice Research Institute(BRRI)Gazipur 1701Bangladesh

Introduction:The brown planthopper(BPH),Nilaparvata lugens(Stål)(Hemiptera:Delphacidae),is a notorious insect pest of *** supplementation can alter plant biochemical compositions which may indirectly affect on ecological fitness parameters of its insect ***,few findings are available on nutrient-induced ecological fitness of BPH and relationship of BPH fitness parameters with its host rice plant biochemical ***:We studied the main and interaction effects of nitrogen(N),phosphorus(P),and potassium(K)inputs on BPH fitness,as measured by the following variables:nymph survival,nymphal duration,adult body weight,and its *** planthopper fitness parameters were regressed as function of rice plant(Oryza sativa)biochemical composition.A completely randomized design with four replications in a factorial scheme was used considering N,P,and K levels as ***:Nitrogen application to the host rice plants provided greater survival and enhanced body weight of *** nymphal duration was found to decrease with N subsidy that caused shorter generation time of *** compounds N and soluble protein(SP),total free sugar(TFS),and silicon(Si)content in rice plant tissue correlated strongly with all fitness traits of ***,SP,and TFS associated positively with BPH survival and body weight,while negatively with nymphal *** contrast,Si had negative correlation with BPH survival and body weight,but positive with nymphal *** supplementation to host plant contributed to increase BPH body *** of P with all parameters of BPH were weak except body weight which was highly significant and *** between N and P inputs demonstrated significant effect on BPH body *** of K had no significant effect on BPH survival and *** analysis did not detect significant relationship of BPH fitness parameters with plant tissue content of ***:The res

关键词： Nilaparvata lugens Nutrient management Survival Nymphal duration Body weight

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Comparative investigation of the free radical scavenging potential and anticancer property of Diospyros blancoi(Ebenaceae)

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Asian Pacific Journal of Tropical Biomedicine 2016年第5期6卷 410-417页

作者： Muhammad Ali Khan Mahbubur Rahman Nazmul Sardar Saiful islam Arman Badrul islam Jahangir Alam khandakar Mamunur Rashid Golam Sadik AHM Khurshid Alam Department of Pharmacy Bangabandhu Sheikh Mujibur Rahman Science and Technology University Department of Pharmacy University of Rajshahi Drugs and Toxins Research Division Bangladesh Council of Scientific and Industrial Research Product Development and Validation Department Square Pharmaceutical Limited Laboratory of Genetics Graduate School of BiostudiesKyoto University

Objective: To investigate the comparative effects of Diospyros blancoi(Ebenaceae)leaves(DBL), root bark(DBRB) and stem bark(DBSB) on free radicals and ***: The polyphenol contents, antioxidant and free radical scavenging properties were determined using standard spectrophotometric methods. Cytotoxicity and anticancer activities were performed on brine shrimp nauplii and Ehrlich ascite carcinoma cells, ***: Among the extracts, DBSB showed the highest total antioxidant capacity and reducing capacity on ferrous ion. Based on 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radical scavenging activities, DBSB showed(95.760 ± 0.343)% and(67.460 ± 2.641)%scavenging with IC50of(3.10 ± 0.17) and(50.00 ± 3.11) mg/m L, respectively. The IC50 values of standard butylated hydroxytoluene and catechin(CA) for 1,1-diphenyl-2-picrylhydrazyl and hydroxyl radicals were(8.50 ± 0.25) and(75.00 ± 0.14) mg/m L,respectively suggesting that DBSB had a significant(P DBRB > CA > ***, the phenolic [(139.91 ± 3.924) mg gallic acid equivalent/g] and flavonoid contents[(412.00 ± 16.70) mg catechin equivalent/g)] of DBSB were higher than that of other extracts. In addition, the DBSB showed the moderate cytotoxic and anticancer ***: Our results indicate that Diospyros blancoi stem bark had the significant highest antioxidant and free radical scavenging properties as well as moderate anticancer ***, we assume that the anticancer activity of this plant can be, at least in part, attributed to its content in phenolic compounds as well as its significant free radical scavenging properties.

关键词： Diospyros blancoi Free radicals Polyphenols Antioxidant Cytotoxicity Anticancer

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Increased humic materials explain aggregate-protected carbon and nitrogen accumulation in biochar-amended tropical soils

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Pedosphere 2024年第6期34卷 1086-1099页

作者： Emmanuel AMOAKWAH Mohammad A.RAHMAN khandakar R.islam Kwame A.FRIMPONG Christian A.PHARES Louis SACKEY Isaac ASIRIFI Emmanuel ARTHUR Council for Scientific and Industrial Research-Soil Research Institute Accra Center Soil Water and Bioenergy Resources The Ohio State University South Centers Department of Soil Science College of Agriculture and Natural Sciences School of Agriculture University of Cape Coast Ruhr-Universit?t Bochum Geographic Institute Department of Soil Science and Soil Ecology Department of Agroecology Faculty of Technical Sciences Arhus University

Humic materials make important contributions to soil organic carbon（C） and nitrogen（N） ***,information on the correlation between humic substances and the accumulation of soil aggregate-protected C and N in response to biochar application under tropical agroecosystems is ***,a field trial was conducted to elucidate the effects of biochar on soil aggregate properties and humic materials and how these humic compounds affect aggregate-protected C and N in a humid tropical *** treatments included no-biochar control（CK）,15 Mg biochar ha-1（BC-15）,30Mg biochar ha-1（BC-30）,and 30 Mg biochar ha-1+phosphate fertilizer（BC-30+P）.The treatments BC-30 and BC-30+P significantly increased the contents of humic materials（humic and fulvic acids） as compared to *** was a significant increase in the mean-weight diameter of soil aggregates by3-and 4-fold in BC-30 and BC-30+P,***,BC-30 and BC-30+P led to significant increases in soil structural coefficient by 3-and 4-fold,re spectively,relative to *** increases in organic C and N accumulation were observed in the macroaggregates of the biochar-amended *** relationships between the degree of polymerization and aggregate-protected C and N were observed,implying that low-molecular-weight aliphatic compounds favor organic C and N accumulation with biochar *** important soil property that contributed to organic C and N accumulation in aggregates was fulvic acid content,which could be used as an early and sensitive indicator to notice early changes in aggregate-protected C and N accumulation in soils of the humid tropics.

关键词： degree of humification fulvic acid humic acid macroaggregates soil structural coefficients

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Elastic Optimization for Stragglers in Edge Federated Learning

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Big Data Mining and Analytics 2023年第4期6卷 404-420页

作者： Khadija Sultana khandakar Ahmed Bruce Gu Hua Wang Institute for Sustainable Industries and Liveable Cities(ISILC) Victoria UniversityMelbourne 3011Australia Intelligent Technology Innovation Lab(ITIL) Institute for Sustainable Industries and Liveable Cities(ISILC)Victoria UniversityMelbourne 3011Australia. Shandong Computer Science Center(National Supercomputer Center) Jinan 250101China

To fully exploit enormous data generated by intelligent devices in edge computing,edge federated learning(EFL)is envisioned as a promising *** distributed collaborative training in EFL deals with delay and privacy issues compared to traditional centralized model ***,the existence of straggling devices,responding slow to servers,degrades model *** consider data heterogeneity from two aspects:high dimensional data generated at edge devices where the number of features is greater than that of observations and the heterogeneity caused by partial device *** large number of features,computation overhead on the devices increases,causing edge devices to become *** incorporation of partial training results causes gradients to be diverged which further exaggerates when more training is performed to reach local *** this paper,we introduce elastic optimization methods for stragglers due to data heterogeneity in edge federated ***,we define the problem of stragglers in ***,we formulate an optimization problem to be solved at edge *** customize a benchmark algorithm,FedAvg,to obtain a new elastic optimization algorithm(FedEN)which is applied in local training of edge *** mitigates stragglers by having a balance between lasso and ridge penalization thereby generating sparse model updates and enforcing parameters as close as to local *** have evaluated the proposed model on MNIST and CIFAR-10 *** experiments demonstrate that our approach improves run time training performance by achieving average accuracy with less communication *** results confirm the improved performance of our approach over benchmark algorithms.

关键词： edge computing federated learning distributed machine learning regularization stragglers

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Efficient ECG classification based on Chi-square distance for arrhythmia detection

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Journal of Electronic Science and Technology 2024年第2期22卷 1-15页

作者： Dhiah Al-Shammary Mustafa Noaman Kadhim Ahmed M.Mahdi Ayman Ibaida khandakar Ahmedb College of Computer Science and Information Technology University of Al-QadisiyahAl Diwaniyah58001Iraq Intelligent Technology Innovation Lab Victoria UniversityMelbourne3011Australia

This study introduces a new classifier tailored to address the limitations inherent in conventional classifiers such as K-nearest neighbor(KNN),random forest(RF),decision tree(DT),and support vector machine(SVM)for arrhythmia *** proposed classifier leverages the Chi-square distance as a primary metric,providing a specialized and original approach for precise arrhythmia *** optimize feature selection and refine the classifier’s performance,particle swarm optimization(PSO)is integrated with the Chi-square distance as a fitness *** synergistic integration enhances the classifier’s capabilities,resulting in a substantial improvement in accuracy for arrhythmia *** results demonstrate the efficacy of the proposed method,achieving a noteworthy accuracy rate of 98% with PSO,higher than 89% achieved without any previous *** classifier outperforms machine learning(ML)and deep learning(DL)techniques,underscoring its reliability and superiority in the realm of arrhythmia *** promising results render it an effective method to support both academic and medical communities,offering an advanced and precise solution for arrhythmia detection in electrocardiogram(ECG)data.

关键词： Arrhythmia classification Chi-square distance Electrocardiogram(ECG)signal Particle swarm optimization(PSO)

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Recognition of Bangla Handwritten Number Using Combination of PCA and FIS with the Aid of DWT

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Journal of Computer and Communications 2020年第9期8卷 109-125页

作者： Samsunnahar khandakar Md. Imdadul islam Fahima Tabassum Risala T. Khan Department of Computer Science & Engineering Jahangirnagar University Dhaka Bangladesh Institute of Information Technology Jahangirnagar University Dhaka Bangladesh

The structure of any Bangla numerical character is more complex compared to English numerical character. Two pairs of numerical character in Bangla resembles to be closed and they are: “one and nine” and “five and six”. We found that, handwritten Bangla numerical character cannot be recognized using single machine learning algorithm or discrete wavelet transform (DWT). Above phenomenon motivated us to use combination of DWT, Fuzzy Inference System (FIS) and Principal Component Analysis (PCA) to recognize numerical characters of Bangla in handwritten format. The four lowest spectral components of a preprocessed image are taken using DWT, which is considered as the feature vector to recognize the digits in first phase. The feature vector is then applied to FIS and PCA separately. The combined method provides recognition accuracy of 95.8% whereas application of individual method gives less rate of accuracy. Instead of storing the images itself in a folder, if we can store the feature vector of images achieved from DWT in tabular form. The records of table can be applied in FIS, PCA or other object detection algorithm. Although the technique used in the paper can detect objects with moderate rate of accuracy but can save huge storage against a benchmark database of images. If a tradeoff is made between storage requirements and accuracy of recognition, the model of the paper is preferable compared to other present state-of-art. Another finding of the paper is that, the spectral components of images acquired by DWT only matched with FIS and PCA for classification but do not match properly with unsupervised (K-mean clustering) and supervised (support vector machine) learning.

关键词： Spectral Components Recognition Accuracy De-Noising Thinning Scheme Principal Components

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Effect of shifting cultivation on soil physical and chemical properties in Bandarban hill district, Bangladesh

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Journal of Forestry Research 2013年第4期24卷 791-795页

作者： khandakar Showkat Osman M.Jashimuddin S.M.Sirajul Haque Sohag Miah Institute of Forestry and Environmental Sciences University of Chittagong

This study reports the effects of shifting cultivation at slashing stage on soil physicochemical properties at Bandarban Sadar Upazila in Chittagong Hill Tracts of Bangladesh. At this initial stage of shifting cultivation no general trend was found for moisture content, maximum water holding capacity, field capacity, dry and moist bulk density, parti- cle density for some chemical properties between shifting cultivated land and forest having similar soil texture. Organic matter was significantly 0.05） lower in 1-year and 3-year shifting cultivated lands and higher in 2-year shifting cultivation than in adjacent natural forest. Significant differences were also found for total N, exchangeable Ca, Mg and K and in CEC as well as for available P. Slashed area showed higher soil pH. Deterioration in land quality starts from burning of slashing materials and continues through subsequent stages of shifting cultivation.

关键词： Chittagong Hill Tracts natural forest shifting cultivation soil properties

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Cover crops,crop rotation,and gypsum,as conservation practices,impact Mehlich-3 extractable plant nutrients and trace metals

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International Soil and Water Conservation Research 2024年第3期12卷 650-662页

作者： Javier M.Gonzalez Warren A.Dick khandakar R.islam Dexter B.Watts Norman R.Fausey Dennis C.Flanagan Marvin T.Batte Tara T.VanToai Randall C.Reeder Vinayak S.Shedekar National Soil Erosion Research Laboratory USDA-ARSWest LafayetteIN 47904USA School of Environment and Natural Resources The Ohio State UnivWoosterOH 44691USA CFAES-South Centers SoilWater&Bioenergy Resources ProgramThe Ohio State Univ.PiketonOH 45661USA National Soil Dynamics Laboratory USDA-ARSAuburnAL 36832USA Soil Drainage Research Unit USDA-ARSColumbusOH 43210USA Department of Agricultural Environmental and Development EconomicsThe Ohio State UnivColumbusOH 43210USA Department of Food Agricultural and Biological EngineeringThe Ohio State Univ.ColumbusOHUSA

Conservation practices are encouraged to improve soil health and sustain agronomic crop ***-3 is often used as a multi-nutrient extractant to determine soil fertility status.A study inves-tigated the impacts of the conservation practices of gypsum,cover crops,and crop rotation on 28 Mehlich-3 extractable elements,of which 11 were considered plant nutrients,from soil at three mid-western US *** was collected from 0 to 15 and 15-30 cm depths 5 years after implementing the conservation *** consisted of(1)with and without cereal rye(Secale cereale L.)winter cover,(2)continuous soybean[Glycine max(L.)Merr.]***-corn(Zea mays L.)rotation,and(3)annual gypsum application(0,1.1,and 2.2 Mg ha-1).Differences were observed by site,depth,and conservation practice depending on the element *** interactive effects were observed among *** most consistent effect was observed for crop rotation across *** only affected the site with the greatest clay content,where more Ca and S were retained,and Mg and Mn *** crop only affected elements at this high clay site,where different elements were positively or negatively *** suggest that not one practice fits all,and optimum conservation practices must be tailored for the site.

关键词： Gypsum Cover crops Crop rotation Mehlich-3 Plant nutrients Trace metals

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