检索结果-南通市图书馆

Differences in Seedling and Sapling Densities and Species Composition between Canopy Gaps and Forest Understories in a Subtropical Forest in Bangladesh

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Resources and Ecology 2025年第1期16卷 105-114页

作者： Tarit Kumar BAUL Anwarul Islam chowdhury Md Jamal UDDIN mohammad Kamrul HASAN Tapan Kumar NATH Lars Holger SCHMIDT Institute of Forestry and Environmental Sciences University of ChittagongChittagong 4331Bangladesh Faculty of Science Forestry and TechnologySchool of Forest SciencesUniversity of Eastern FinlandJoensuu 80101Finland Department of Agricultural and Forest Sciences and Engineering University of LleidaLleida 25001Spain Natural Resources Institute Finland(Luke) Helsinki 00790Finland Faculty of Science and Engineering University of Nottingham MalaysiaJalan Broga 43500Malaysia Department of Geoscience and Natural Resource Management University of CopenhagenFrederiksberg C 1958Denmark

Canopy openings have a vital role in forest structure,regeneration,and plant *** this study,we investigated and compared the species composition and densities of seedlings and saplings between canopy gaps(openings)and forest understories(in dense canopies)in a sub-tropical forest of *** objectively identified 42 canopy openings between transect lines and 42 main plots in dense canopies,sampled for regeneration and young tree *** the regeneration study,we placed 2 m×2 m four subplots in each canopy opening and the main plot of dense canopy,thus making a total of 336 *** species diversity of seedlings,saplings,and trees were significantly(P≤0.05)higher in the dense canopy than in the canopy ***,most dominant and frequent regenerating species such as Diospyros pilosula,Garcinia cowa,Brownlowia elata,and Lithocarpus polystachya were common in both dense canopy and openings,the canopy openings had the highest Importance Value Index,suggesting the significance of gap dynamics in the dominance of native floral *** dense canopy played an important role in forest compositions because 12 regenerating species,including Stereospermum suaveolens and Diospyros montana,were not found in the canopy openings,implying that rain forests must maintain a high canopy cover for regeneration.

关键词： canopy opening disturbance forest dynamics native flora seedling sapling

Acute and chronic toxicity of nickel to nitrifiers at different temperatures

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2019年第8期31卷 169-178页

作者： Xiaoguang Liu mohammad M.I.chowdhury Masuduz Zaman Mingu Kim George Nakhla Department of Civil and Environmental Engineering University of Western Ontario Department of Chemical and Biochemical Engineering University of Western Ontario

This study investigated the acute nickel toxicity on nitrification of low ammonia synthetic wastewater at 10, 23, and 35°C. The nickel inhibition half-velocity constants(K_(I,Ni)) for ammonia oxidizing bacteria(AOB) and nitrite oxidizing bacteria(NOB) based on Ni/MLSS ratio at 10, 23, and 35°C were 5.4 and 5.6 mg Ni/g MLSS, 4.6 and 3.5 mg Ni/g MLSS, and 9.1 and 2.7 mg Ni/g MLSS, respectively. In addition, chronic toxicity of nickel to nitrification of low ammonia synthetic wastewater was investigated at 10°C in two sequencing batch reactors(SBRs). Long-term SBRs operation and short-term batch tests were comparable with respect to the extent of inhibition and corresponding Ni/MLSS ratio. The μ_(max), b, and K_o of AOB were 0.16 day^(-1), 0.098 day^(-1) and 2.08 mg O_2/L after long-term acclimatization to nickel of 1 mg/L at 10°C, high dissolved oxygen(DO)(7 mg/L) and long solids retention time(SRT) of 63–70 days. Acute nickel toxicity of nitrifying bacteria was completely reversible.

关键词： Nickel inhibition Temperature Nitrifying culture Activated sludge Toxicity

Deposition behavior and tribological properties of diamond-like carbon coatings on stainless steels via chemical vapor deposition

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2018年第11期25卷 1335-1343页

作者： Labani Mustafi M.M.Rahman mohammad Nur E Alam Al Nasim mohammad Asaduzzaman chowdhury M.H.Monir School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China School of Engineering RMIT UniversityMelbourneVictoria 3001Australia Dhaka University of Engineering and Technology Gazipur 1707Bangladesh

A systematic investigation was carried out to observe the deposition rate of a diamond-like carbon(DLC) coating on two stainless steel substrates by chemical vapor deposition(CVD). The objective of this research is to study the deposition behavior of the DLC coating and its tribological properties in different combinations of methane(CH_4) and nitrogen, which were used as precursor gases. The results reveal that the deposition rate increases with increasing CH_4 content up to 50 vol%. The hardness of the DLC-deposited layer also increases while the friction coefficient decreases with increasing CH_4 gas content up to 50% in the precursor gas mixture.

关键词： diamond-like carbon chemical vapor deposition methane and nitrogen gas mixtures deposition rate hardness friction coefficient

In vitro antioxidant,cytotoxic,thrombolytic activities and phytochemical evaluation of methanol extract of the *** ***

在线全文

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Biomedicine 2013年第6期3卷 464-469页

作者： mohammad Sekendar Ali mohammad Ruhul Amin chowdhury mohammad Imtiaz Kamal mohammad Aslam Hossain Department of Pharmacy International Islamic University Chittagong Department of Pharmaceutical Chemistry Faculty of PharmacyUniversity of Dhaka

Objective:To study the leaves of Adiantum philippense *** their antioxidant,cytotoxicity and thrombolytic activities and to perform phytochemical ***:In-vitro antioxidant activity of extract was studied using DPPH radical scavenging,reducing power,total phenol and total flavonoid content determination *** cytotoxic activity was determined using brine shrimp lethality bioassay,thrombolytic activity by clot disruption and phytochemical potential by qualitative ***:The antioxidant activity of the extracts was found *** reducing power of this crude extract increase with the increase of concentration;IC_(50)values of DPPH scavenging activity was(140.00±0.86)μg/mL as compared to ascorbic acid[IC_(50)(130.00±0.76)μg/mL];Total phenol and total flavonoids content were(148.26±0.24)mg/mL and(163.06±0.56)mg/mL *** cytotoxicity assay the LC_(50)values of the sample was(106.41±0.78)μg/mL where as for standard vincristin sulphate was(08.50±0.24)μg/mL as a positive control and the extract shows(12.8611.02)%clot lytic whereas standard streptokinase shows(30.86+0.44%clot lytic activity in thrombolytic *** phytochemical evaluation indicates the presence of chemical constituents including carbohydrates,alkaloids,saponins,glycosides,***:This study shows that the methanol extract of leaves of Adiantum philippense *** bioactivitv but further compound isolation is necessary to confirm the activities of individual compounds.

关键词： Adiantum philippense L. Antioxidant Cytotoxicity Phytochemical evaluation

Variable selection strategies and its importance in clinical prediction modelling

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Family Medicine and Community Health 2020年第1期8卷 37-43页

作者： mohammad Ziaul Islam chowdhury Tanvir C Turin Department of Community Health Sciences Cumming School of MedicineUniversity of CalgaryCalgaryAlbertaCanada Department of Family Medicine Cumming School of MedicineUniversity of CalgaryCalgaryAlbertaCanada

Clinical prediction models are used frequently in clinical practice to identify patients who are at risk of developing an adverse outcome so that preventive measures can be initiated.A prediction model can be developed in a number of ways;however,an appropriate variable selection strategy needs to be followed in all *** purpose is to introduce readers to the concept of variable selection in prediction modelling,including the importance of variable selection and variable reduction *** will discuss the various variable selection techniques that can be applied during prediction model building(backward elimination,forward selection,stepwise selection and all possible subset selection),and the stopping rule/selection criteria in variable selection(p values,Akaike information criterion,Bayesian information criterion and Mallows’Cp statistic).This paper focuses on the importance of including appropriate variables,following the proper steps,and adopting the proper methods when selecting variables for prediction models.

关键词： criterion backward subset

Shadow banking:a bibliometric and content analysis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Financial Innovation 2021年第1期7卷 1586-1614页

作者： Ridoy Deb Nath mohammad Ashraful Ferdous chowdhury Department of Business Administration Shahjalal University of Science and TechnologySylhetBangladesh

This study reports on our systematic review of 2008–2021 literature on shadow *** present an overview of the shadow banking sector,wherein we discuss the definitions,evolution,functions,and specific activities that comprise *** conducted a bibliometric analysis using the VOSviewer bibliometric tool on articles collected from the Scopus database,after which we conducted content analysis on top articles from leading sources,and identified four major streams of shadow banking ***,we identified gaps in the literature and proposed seven research questions to be addressed in future studies to advance knowledge of the shadow banking *** findings of this review may serve as a robust reference for scholars researching various aspects of shadow banking to develop our understanding of this sector.

关键词： Shadow banking Review study Bibliometric analysis Content analysis VOSviewer

Enhancing Septic Shock Detection through Interpretable Machine Learning

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2024年第12期141卷 2501-2525页

作者： Md Mahfuzur Rahman Md Solaiman chowdhury mohammad Shorfuzzaman Lutful Karim Md Shafiullah Farag Azzedin Department of Information and Computer Science King Fahd University of Petroleum and MineralsDhahran31261Saudi Arabia Department of Electrical and Computer Engineering North South UniversityDhaka1229Bangladesh Department of Computer Science Taif UniversityTaif21974Saudi Arabia College of Applied Arts and Technology Seneca PolytechnicTorontoM2J 2X5Canada Department of Control&Instrumentation Engineering King Fahd University of Petroleum and MineralsDhahran31261Saudi Arabia

This article presents an innovative approach that leverages interpretable machine learning models and cloud computing to accelerate the detection of septic shock by analyzing electronic health *** traditional methods,which often lack transparency in decision-making,our approach focuses on early detection,offering a proactive strategy to mitigate the risks of *** integrating advanced machine learning algorithms with interpretability techniques,our method not only provides accurate predictions but also offers clear insights into the factors influencing the model’s ***,we introduce a preference-based matching algorithm to evaluate disease severity,enabling timely interventions guided by the analysis *** innovative integration significantly enhances the effectiveness of our *** leverage a clinical health dataset comprising 1,552,210 Electronic Health Records(EHR)to train our interpretable machine learning models within a cloud computing *** techniques like feature importance analysis and model-agnostic interpretability tools,we aim to clarify the crucial indicators contributing to septic shock *** transparency not only assists healthcare professionals in comprehending the model’s predictions but also facilitates the integration of our system into existing clinical *** validate the effectiveness of our interpretable models using the same dataset,achieving an impressive accuracy rate exceeding 98%through the application of oversampling *** findings of this study hold significant implications for the advancement of more effective and transparent diagnostic tools in the critical domain of sepsis management.

关键词： Sepsis prediction machine learning cloud computing

Allometric relationship for estimating above-ground biomass of Aegialitis rotundifolia Roxb. of Sundarbans mangrove forest, in Bangladesh

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Forestry Research 2012年第1期23卷 23-28页

作者： mohammad Raqibul Hasan Siddique Mahmood Hossain Md. Rezaul Karim chowdhury Forestry and Wood Technology Discipline Khulna University Khulna-9208 Bangladesh

Tree biomass plays a key role in sustainable management by providing different aspects of ecosystem. Estimation of above ground biomass by non-destructive means requires the dex;elopment of allometric equations. Most researchers used DBH （diameter at breast height） and TH （total height） to develop allometric equation for a tree. Very few spe- cies-specific allometric equations are currently available for shrubs to estimate of biomass from measured plant attributes. Therefore, we used some of readily measurable variables to develop allometric equations such as girth at collar-height （GcH） and height of girth measuring point （GMH） with total height （TH） for A. rotundifolia, a mangrove species of Sundarbans of Bangladesh, as it is too dwarf to take DBH and too ir- regular in base to take Girth at a fixed height. Linear, non-linear and logarithmic regression techniques were tried to determine the best re- gression model to estimate the above-ground biomass of stem, branch and leaf. A total of 186 regression equations were generated from the combination of independent variables. Best fit regression equations were determined by examining co-efficient of determination （R：）, co-efficient of variation （Cv）, mean-square of the error （Ms^r）, residual mean error （Rmax）, and F-value. Multiple linear regression models showed more efficient over other types of regression equation. The performance of regression equations was increased by inclusion of GMn as an independ- ent variable along with total height and GCH.

关键词： Aegialitis rotundifolia allometry biomass mangroves sundarbans

Management of early appendicular lump in children-laparoscopic technique versus open surgery:a comparative study in low-middle income country perspective

在线全文

学校读者我要写书评

暂无评论

World Journal of Pediatric Surgery 2020年第2期3卷 24-28页

作者： mohammad Zonaid chowdhury Md Abdullah Al Farooq M A Mushfiqur Rahman Tanvir Kabir chowdhury Department of Pediatric Surgery Chittagong Medical CollegeChattogramBangladesh

Background In the pediatric population,appendectomy is one of the most common emergency *** appendectomy(LA)is an accepted way of dealing with suspected uncomplicated appendicitis in *** role of laparoscopy in appendicular lump is more controversial and remains undefined and is not well practiced in low-middle income *** aim of this study was to determine a better surgical treatment plan for early appendicular lump in *** This prospective observational study was performed in Pediatric Surgery Department of Chittagong Medical College and Hospital for a period of 1 year from April 2018 to March *** children with appendicular lump selected consecutively as per eligibility criteria underwent either LA or open appendectomy(OA),that is,30 children per *** were followed up until hospital discharge to observe *** There were no differences in terms of patient’s age,sex,clinical presentation and laboratory findings between the two *** pain severity was significantly less in the LA group than that in the OA group(p<0.01).The incidence of wound infection was significantly lower in the LA group than that in the OA group(6.7%in LA and 46.7%in OA;p<0.01).Children in the LA group had a shorter duration of hospital stay in comparison to the OA group[median(IQR)was 8(5.75-11.25)days and 12(7.75-18.00)days,respectively,in LA and OA groups;p=0.01].Conclusion The study findings suggest that LA is feasible and should replace OA in cases of early appendicular lump in children.

关键词： Surgery wound income