检索结果-南通市图书馆

Ecological Consequences of Land Use Change: Forest Structure and Regeneration across the Forest-grassland Ecotone in Mountain Pastures in Nepal

引用

Journal of Mountain Science 2014年第4期11卷 838-849页

作者： lila nath sharma Ole Reidar VETAAS Ram Prasad CHAUDHARY Inger Elisabeth MREN Department of Geography University of Bergen Bergen 5020 Norway Research Centre for Applied Science and Technology and Central Department of Botany Tribhuvan UniversityKathmandu 977 Nepal

The ecotone, the spatial transition zone between two vegetation communities, is claimed to have more species than the adjoining communities. However, empirical studies do not always confirm higher richness at the ecotone. The ecotone position and structure are dynamic over time and space and it is driven by the changes in climate, land use or their interaction. In this context, we assessed the forest- grassland ecotone of temperate mountains in central Nepal by i） comparing species composition and richness across the ecotone, ii） analyzing if the forestgrassland ecotone is shifting towards the grassland center by colonizing them with trees, and iii） discussing the consequence of changed disturbance regime in the dynamics of this ecotone and the surrounding grasslands. We analyzed vegetation data sampled from belt transects laid across the forest- grassland ecotone in semi-natural grassland patches. Vegetation data consisting of species richness and composition, and size structure and regeneration of the two most dominant tree species, namely Rhododendron arboreum and Abies spectabilis, from the transects, were used to analyze the trend of the forest-grassland ecotone. Forest and grasslands were different in terms of floristic composition and diversity. Vascular plant speciesrichness linearly increased while moving from forest interior to grassland center. Spatial pattern of tree size structure and regeneration infers that forest boundary is advancing towards the grasslands at the expense of the grassland area, and tree establishment in the grasslands is part of a suceessional process. Temporally, tree establishment in grasslands started following the gradual decline in disturbance. We argue that local processes in terms of changed land use may best explain the phenomenon of ecotone shift and consequent forest expansion in these grasslands. We underpin the need for further research on the mechanism, rate and spatial extent of ecotone shift by using advaneed tools to

关键词： Ecotone shift Grasslands Forest Landuse change Rhododendron

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Random Amplification Polymorphic DNA and Agro-Morphological Traits-Based Fingerprinting for Detection of Genetic Divergence in Indian Black Rice

引用

Rice science 2024年第4期31卷 366-370,I0004-I0014页

作者： Manisha sharma Dhananjay RATURI Vijay Rani RAJPAL Manju CHAUDHARY Soom nath RAINA Apekshita SINGH Amity Institute of Biotechnology Amity University Uttar PradeshSector-125UP 201313India Department of Botany Hansraj CollegeUniversity of DelhiDelhi 110007India

In this study, 32 black rice genotypes spanning diverse geographies in India were evaluated at both phenotypic and DNA sequence levels to gain insights into their genetic makeup. Significant variations were observed f... 详细信息

关键词： Indian Morphological Traits

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Development and validation of analytical method for the estimation of lamivudine in rabbit plasma

引用

Journal of Pharmaceutical Analysis 2011年第4期1卷 251-257页

作者： Akhilesh Vikram Singh lila K.nath Nihar R.Pani Department of Pharmaceutical Sciences Dibrugarh UniversityDibrugarhAssamIndia Gayatri College of Pharmacy SambalpurOrissaIndia

Lamivudine has been widely used in the treatment of HIV disease. A reliable, sensitive reversed phase high performance liquid chromatography （RP-HPLC） method was developed and validated for lamivudine in rabbit plasma. The method was developed on Hypersil BDS C-18 column （250 mm ＊ 4.6 mm, 5 μm） using a mobile phase of 0.25% Triethylamine buffer （pH 3.0）： acetonitrile （70：30, v/v）. The efficient was monitored by UV detector at 256 nm. The total run time was 15 min with a flow rate of 1.0 mL/min. Calibration curve was linear over the concentration range of 25-2000 ng/mL. The retention times of lamivudine and internal standard （Nelfinavir） were 8.78 min and 10.86 min, respectively. The developed RP-HPLC method can be successfully applied for the quantitative pharmacokinetic parameters determination of lamivudine in rabbit model.

关键词： Lamivudine Rabbit plasma Pharmacoldnetics RP.HPLC

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

MicroRNAs:a new ray of hope for diabetes mellitus

引用

Protein & Cell 2012年第10期3卷 726-738页

作者： Munish Kumar Sayantan nath Himanshu K Prasad G D sharma Yong Li Department of Biotechnology Assam UniversitySilchar 788011 India 2 Department of Life Science and Bioinformatics Assam UniversitySilchar 788011 India 3 Department of Biochemistry and Molecular Biology University of LouisvilleKY 40292USA

Diabetes mellitus has become one of the most common chronic diseases,thereby posing a major challenge to global *** by high levels of blood glucose(hyperglycemia),diabetes usually results from a loss of insulin-producing β-cells in the pancreas,leading to a deficiency of insulin(type 1 diabetes),or loss of insulin sensitivity(type 2 diabetes).Both types of diabetes have serious secondary complications,such as microvascular abnormalities,cardiovascular dysfunction,and kidney *** complex factors,such as genetic and environmental factors,are associated with the pathophysiology of *** the past two decades,the role of small,single-stranded noncoding microRNAs in various metabolic disorders,especially diabetes mellitus and its complications,has gained widespread attention in the scientific *** first as an endogenous regulator of development in the nematode Caenorhabditis elegans,these small RNAs post-transcriptionally suppress mRNA target *** this review,we discuss the potential roles of different microRNAs in diabetes and diabetes-related complications.

关键词： diabetes diabetic complications dicer glucose insulin microRNA pancreas

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Purification, characterization and evaluation of insecticidal activity of trypsin inhibitor from Albizia lebbeck seeds

引用

Journal of Forestry Research 2012年第1期23卷 131-137页

作者： Pratima sharma Amarjit K nath Reena Kumari SV Bhardwaj Department of Biotechnology UHFNauniSolanIndia

A Bowman-Birk inhibitor with activity against gut proteases of Helicoverpa armigera was extracted in 0.I M sodium phosphate buffer from defatted seed flour of Albizia lebbeck. It was purified to 29.62 folds with 51.43% recovery using ammonium sulfate precipitation, gel filtration chromatography on Sephadex G-100 column and ion ex- change chromatography on DEAE-Sephadex As0. The purified protein had a molecular weight of 12,303 daltons as determined by SDS-PAGE. It was found to be heat stable up to 60~C and had two pH optima of 7.5 and 9.0. The inhibitor exhibited non-competitive pattern of inhibition with a low Ki value of 0.2 ~tM. The inhibitoi- was found to be susceptible to varying concentrations of reducing agents like DTT and 2- mercaptoethanol, thereby indicating the role of disulphide bridges in maintaining its three dimensional structure and stability. The purified inhibitor caused mortality and suppressed larval growth ofPieris brassi- cae larvae. It was also found to be effective against gut trypsin extracted from Spodoptera littoralis. The sequence of the genes encoding for such inhibitors can be determined and the genes expressing protease inhibitors can be used in vegetable crops to confer resistance against insect pests and other plant pathogens.

关键词： Albizia lebbeck trypsin inhibitor insecticidal activity purifi-cation Pieris brassicae

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Elevation, Slope Aspect and Integrated Nutrient Management Effects on Crop Productivity and Soil Quality in North-west Himalayas, India

引用

Journal of Mountain Science 2014年第5期11卷 1208-1217页

作者： Birendra nath GHOSH Narinder Kumar sharma Nurnabi Meherul ALAM Raman Jeet SINGH Gopal Prasad JUYAL Central Soil and Water Conservation Research and Training Institute 218 Kaulagarh Road Dehradun-248 195 Uttarakhand India

On farm bio-resource recycling has been given greater emphasis with the introduction of conservation agriculture specifically withclimate change scenarios in the mid-hills of the north-west Himalaya region（NWHR）. Under this changing scenario, elevation, slope aspect and integrated nutrient management（INM） may affect significantly soil quality and crop productivity. A study was conducted during 2009-2010 to 2010-2011 at the Ashti watershed of NWHR in a rainfed condition to examine the influence of elevation, slope aspect and integrated nutrient management（INM） on soil resource and crop productivity. Two years of farm demonstration trials indicated that crop productivity and soil quality is significantly affected by elevation, slope aspect and INM. Results showed that wheat equivalent yield（WEY） of improved technology increased crop productivity by -20%-37% compared to the conventional system. Intercropping of maize with cowpea and soybean enhanced yield by another 8%-17%. North aspect and higher elevation increased crop productivity by 15%-25% compared to south aspect and low elevation（except paddy）. Intercropping of maize with cowpea and soybean enhanced yield by another 8%-15%. Irrespective of slope, elevation and cropping system, the WEY increased by -30% in this region due to INMtechnology. The influence of elevation, slope aspect and INM significantly affected soil resources（SQI） and soil carbon change（SCC）. SCC is significantly correlated with SQI for conventional（R2 = 0.65＊）, INM technology（R2 = 0.81＊） and for both technologies（R2 = 0.73＊）. It is recommended that at higher elevation.（except for paddy soils） with a north facing slope, INM is recommended for higher crop productivity; conservation of soil resources is recommended for the mid hills of NWHR; and single values of SCC are appropriate as a SQI for this region.

关键词： Elevation Crop productivity Integrated nutrient management(INM) Slope aspect and soil quality

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Efficient Microorganism Compost Benefits Plant Growth and Improves Soil Health in Calendula and Marigold

引用

Horticultural Plant Journal 2017年第2期3卷 67-72页

作者： Anamika sharma Tarak nath Saha Anju Arora Raghubir Shah Lata Nain Division of Microbiology Indian Agricultural Research Institute Directorate of Floriculture Research Shivaji Nagar

Organic farming needs to be promoted as a means of sustaining soil health and reducing the cost of farming, especially for small *** present study deals with the effect of organic compost, prepared using Efficient Microorganism(EM) consortium and applied along with full or half of the recommended dose of chemical fertilizers, on the growth of Calendula and Marigold plants, soil physico-chemical parameters and soil enzyme activities. Soil enzyme activities were improved with the increase in the rate of EM compost application in both Calendula and Marigold. Carotenoid pigment increased by 46.11% and 12.19% with application of EM compost over the control in Calendula and Marigold flowers respectively. Soil humus, available nitrogen and organic carbon content also increased due to the supplementation of EM compost resulting in better soil fertility. For Calendula, treatment T5(Half dose NPK + EM compost 20 000 kg·hm^(-2)) was found to be the most promising in terms of acid phosphatase(82.63 μg p-Nitrophenyl Phosphate·g^(-1)·h^(-1)), dehydrogenase(10.46 μg Triphenyl Formazan·g^(-1)·d^(-1)) and β-glucosidase(0.30 IU·g^(-1)) activities. In Marigold, treatment C(Half dose NPK + EM compost 5 000 kg·hm^(-2)) was the most promising in terms of amendment in soil enzyme activities.

关键词： calendula marigold EM compost soil fertility plant growth soil enzyme activity soil physico-chemical parameter

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Underutilized Plant Species in Far West Nepal

引用

Journal of Mountain Science 2012年第5期9卷 589-600页

作者： Ripu M.KUNWAR Laxmi MAHAT lila N.sharma Keshab P.SHRESTHA Hiroo KOMINEE Rainer W.BUSSMANN Centre for Biological Conservation Kirtipur-3NayabazarKathmanduNepal GPO Box 19925 Kalanki-1444600KathmanduNepal Natural History Museum SwayambhuTribhuvan University Hatai Clinic KYG Iryoukai Medical Association2-47-22 Togo Iryou Building 1F NakachoTokyoJapan William L.Brown Center Missouri Botanical GardenSt.LouisMO 63110USA

Underutilized plant species help to alleviate common food insufficiencies by providing alternative food supply. They also complement primary health care, furnishing raw materials where the cultivation of staple cereal crops is least feasible and health care is pursued indigenously. Research and promotion of extraction, utilization, and conservation of underutilized species lead to exploration of new staple crops and motivate people to consume in a sustainable manner. The present study describes the current status, uses, and management of underutilized plant species in Far West Nepal. The relative importance of 49 underutilized plant species was computed employing a Relative Importance (RI) technique. The use-values assigned to the species fall into six use-categories: beverage, fodder, food & edible, medicinal, vegetable and veterinary. A total of 22 species appeared in multiple use-categories, while the rest were characterized by a single use-category. Based on relative importance and frequency, Ficus semicordata, Debregesia longifolia, Girardinea diversifolia, Hydrocotyle nepalensis, Garuga pinnata, Aloe vera and Pyrus pashia offer the most potential for future. Underutilized plants proved important to folk medicine and food. These species persist because they remain useful to local people as means of subsistence, production, and primary health care. The findings are important so far as they point up the role of underutilized plants in national food security policy and health care, spelling out their potentialities and cross cutting relationships.

关键词： Underutilized plants Relativeimportance (R/) Ethnoveterinary use Conservation Nepal

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

3-D Exact Vibration Analysis of a Generalized Thermoelastic Hollow Sphere with Matrix Frobenius Method

引用

World Journal of Mechanics 2012年第2期2卷 98-112页

作者： Jagan nath sharma N. sharma Department of Mathematics National Institute of Technology Hamirpur India

This paper presents exact free vibration analysis of stress free (or rigidly fixed), thermally insulated (or isothermal), transradially isotropic thermoelastic hollow sphere in context of generalized (non-classical) theory of thermoelasticity. The basic governing equations of linear generalized thermoelastic transradially isotropic hollow sphere have been uncoupled and simplified with the help of potential functions by using the Helmholtz decomposition theorem. Upon using it the coupled system of equations reduced to ordinary differential equations in radial coordinate. Matrix Frobenius method of extended series has been used to investigate the motion along the radial coordinate. The secular equations for the existence of possible modes of vibrations in the considered sphere are derived. The special cases of spheroidal (S-mode) and toroidal (T-mode) vibrations of a hollow sphere have also been deduced and discussed. The toroidal motion gets decoupled from the spheroidal one and remains independent of the both, thermal variations and thermal relaxation time. In order to illustrate the analytic results, the numerical solution of the secular equation which governs spheroidal motion (S-modes) is carried out to compute lowest frequencies of vibrational modes in case of classical (CT) and non-classical (LS, GL) theories of thermoelasticity with the help of MATLAB programming for the generalized hollow sphere of helium and magnesium materials. The computer simulated results have been presented graphically showing lowest frequency and dissipation factor. The analysis may find applications in engineering industries where spherical structures are in frequent use.

关键词： Thermal Relaxation Matrix Frobenius Method Toroidal Poloidal Hollow Sphere

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acousto-Diffusive Waves in a Piezoelectric-Semiconductor-Piezoelectric Sandwich Structure

引用

World Journal of Mechanics 2011年第5期1卷 247-255页

作者： Jagan nath sharma Kuldeep Kumar sharma Ashwani Kumar 不详

The propagation of acoustic waves in a homogeneous isotropic semiconducting layer sandwiched between two homogeneous transversely isotropic piezoelectric halfspaces has been investigated. The mathematical model of the problem is depicted by a set of partial differential equations of motion, Gauss equation in piezoelectric material and electron diffusion equation in semiconductor along with the boundary conditions to be satisfied at the piezoelectric-semiconductor interfaces. The secular equations describing the symmetric and asymmetric modes of wave propagation have been derived in compact form after obtaining the analytical expressions for various field quantities that govern the wave motion. The complex secular equation has been solved numerically using functional interaction method along with irreducible cardano method. The computer simulated results are obtained with the help of MATLAB software for 6 mm cadmium selenide (CdSe) piezoelectric material and n-type silicon (Si) semiconductor in respect of dispersion curve, attenuation and specific loss factor of energy dissipation for symmetric (sym) and asymmetric (asym) modes of wave propagation. The study may find applications in non-destructive testing, resonators, waveguides etc.

关键词： Acousto-Diffusive Sandwich Structure Halfspace Piezoelectricity

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：