检索结果-南通市图书馆

Variation in soil organic matter accumulation and metabolic activity along an elevation gradient in the Santa Rosa Mountains of Southern California, USA

在线全文

学校读者我要写书评

暂无评论

Journal of Arid Land 2015年第6期7卷 814-819页

作者： amitava chatterjee George D JENERETTE Department of Soil Science North Dakota State University Department of Botany and Plant Sciences University of California

Variations in soil organic matter accumulation across an elevation can be used to explain the control of substrate supply and variability on soil metabolic activity. We investigated geographic changes in soil organic matter and metabolic rates along an elevation gradient（289–2,489 m） in the Santa Rosa Mountains, California, USA from subalpine and montane pine forests through chaparral to desert. From base（289 m） to summit（2,489 m）, 24 sites were established for collecting soil samples under canopies and inter-canopy spaces, at 0–5 and 5–15 cm soil depths increments. Soil organic matter（SOM） content was determined using weight loss on ignition at 550°C and soil CO2 efflux（R） was measured at day 5（R5） and day 20（R20） of incubation. Changes in SOM content along the elevation gradient showed a significant relationship（P〈0.05） but R5 and R20 were not related to either elevation or SOM content. However, the ratio of R and SOM（R5/SOM） showed a strong relationship across the mountains at both soil depths. R5/SOM, as an indicator of carbon use efficiency, may be applicable to other semi-arid transects at larger scale modeling of soil metabolic processes.

关键词： elevation gradient soil organic matter CO2 efflux metabolic activity

Carbon Dioxide and Nitrous Oxide Emissions from Naturally Occurring Sulfate-Based Saline Soils at Different Moisture Contents

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2017年第5期27卷 868-876页

作者： Resham THAPA amitava chatterjee Abbey WICK Kirsten BUTCHER Department of Soil Sciences School of Natural Resources Management North Dakota State University

Soil salinization may negatively affect microbial processes related to carbon dioxide （CO2） and nitrous oxide （N20） emissions. A short-term laboratory incubation experiment was conducted to investigate the effects of soil electrical conductivity （EC） and moisture content on CO2 and N20 emissions from sulfate-based natural saline soils. Three separate 100-m long transects were established along the salinity gradient on a salt-affected agricultural field at Mooreton, North Dakota, USA. Surface soils were collected from four equally spaced sampling positions within each transect, at the depths of 0-15 and 15-30 cm. In the laboratory, artificial soil cores were formed combining soils from both the depths in each transect, and incubated at 60% and 90% water-filled pore space （WFPS） at 25 ~C. The measured depth-weighted EC of the saturated paste extract （ECe） across the sampling positions ranged from 0.43 to 4.65 dS m-1. Potential nitrogen （N） mineralization rate and CO2 emissions decreased with increasing soil ECe, but the relative decline in soil CO2 emissions with increasing ECe was smaller at 60% WFPS than at 90% WFPS. At 60% WFPS, soil N20 emissions decreased from 133 g N20-N kg-1 soil at ECe （ 0.50 dS m-1 to 72 μg N20-N kg-1 soil at ECe = 4.65 dS m-1. In contrast, at 90% WFPS, soil N20 emissions increased from 262 g N20-N kg-1 soil at ECe ： 0.81 dS m-1 to 849 g N20-N kg-1 soil at ECe ： 4.65 dS m-1, suggesting that N20 emissions were linked to both soil ECe and moisture content. Therefore, spatial variability in soil ECe and pattern of rainfall over the season need to be considered when up-scaling N20 and CO2 emissions from field to landscape scales.

关键词： electric conductivity C and N mineralization salinity sulfate salts soil salinization soil water-filled pore space

Saline-Sodic Soils:Potential Sources of Nitrous Oxide and Carbon Dioxide Emissions?

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2017年第1期27卷 65-75页

作者： Upasana GHOSH Resham THAPA Thomas DESUTTER HE Yangbo amitava chatterjee Department of Soil Science North Dakota State University Key Laboratory of Arable Land Conservation(Middle and Lower Reaches of the Yangtze River) Ministry of AgricultureHuazhong Agricultural University

Increasing salt-affected agricultural land due to low precipitation, high surface evaporation, irrigation with saline water, and poor cultural practices has triggered the interest to understand the influence of salt on nitrous oxide （N20） and carbon dioxide （CO2） emissions from soil. Three soils with varying electrical conductivity of saturated paste extract （ECe）（0.44-7.20 dS m-1） and sodium adsorption ratio of saturated paste extract （SARe）（1.1-27.7）, two saline-sodic soils （S2 and S3） and a non-saline, non-sodic soil （S1）, were incubated at moisture levels of 40%, 60%, and 80% water-filled pore space （WFPS） for 30 d, with or without nitrogen （N） fertilizer addition （urea at 525μg g-1 soil）. Evolving CO2 and N20 were estimated by analyzing the collected gas samples during the incubation period. Across all moisture and N levels, the cumulative N20 emissions increased significantly by 39.8% and 42.4% in S2 and S3, respectively, compared to S1. The cumulative CO2 emission from the three soils did not differ significantly as a result of the complex interactions of salinity and sodicity. Moisture had no significant effect oi1 N20 emissions, but cumulative CO2 emissions increased significantly with an increase in moisture. Addition of N significantly increased cumulative N20 and CO2 emissions. These showed that saline-sodic soils can be a significant contributor of N20 to the environment compared to non-saline, non-sodic soils. The application of N fertilizer, irrigation, and precipitation may potentially increase greenhouse gas （N20 and CO2） releases from saline-sodic soils.

关键词： CO2 electrical conductivity greenhouse gas emission moisture N fertilizer application N20 salinity sodicity sodiumadsorption ratio

Relationship among Different Soil Biochemical Methods to Determine Soil Health

在线全文

学校读者我要写书评

暂无评论

Open Journal of Soil Science 2018年第11期8卷 303-313页

作者： amitava chatterjee Umesh Acharya Department of Soil Science North Dakota State University Fargo USA

Numerous soil biochemical methods are used to determine the soil health status, but the relationships among these methods are not well understood. Relationships among soil biochemical tests, 1) chloroform fumigated microbial biomass C (CFMBC), 2) permanganate oxidizable C (POXC), 3) Solvita CO2-burst (Solvita), 4) Solvita labile amino nitrogen (SLAN), and short-term soil CO2 efflux during laboratory incubation using (v) Alkali-base trap (Alkali) and (vi) infrared gas analyzer (IRGA), were evaluated for nine agricultural soils collected across the Red River Valley of North Dakota and Minnesota, USA. Not a single test is comprehensive to relate with all soil biochemical tests. Coefficient of variation percentage for particular method varied with soil type. Among six tests, CFMBC is significantly (p < 0.05) related with Alkali (r = 0.37), Solvita (r = 0.57), SLAN (r = 0.52), and POXC (r = 0.68). Soil CFMBC correlates with most of soil biochemical tests and can be potential to determine soil biochemical condition.

关键词： Chloroform Fumigated Microbial Biomass Carbon Solvita CO2-Burst Soil Labile Amino Nitrogen (SLAN) Permanganate Oxidizable Carbon Infrared Gas Analyzer Soil Organic Carbon

Integrin Alpha-V Beta-3-Matrix Metalloproteinase-2 (MMP-2), Cross-Talk

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 Cancer Therapy 2015年第9期6卷 793-802页

作者： Hrishikesh Sil amitava chatterjee Department of Receptor Biology & Tumor Metastasis Chittaranjan National Cancer Institute Kolkata India Ramakrishna Mission Vivekananda University (IRDM) Narendrapur Kolkata India

The present study aimed to detect comparative expression of integrin αVβ3 and its involvement in expression and activation of matrix metalloproteinase-2 (MMP-2) in 25 malignant human breast tumor and adjacent normal breast tissues from different clinical TNM stages (DCIS to T4) of the disease and possible involvement of known regulating parameters of MMP-2 like TIMP-2, MT1-MMP and EMPRIN. Integrin αVβ3 was highly expressed in tumors than adjacent normal breast tissues. Pro-MMP-2(72-KD) was mainly expressed in adjacent normal tissues compared to tumors. The mature forms of MMP-2 (68 KD and 64 KD) were found only in tumors. Appreciable expression of TIMP-2 and induction of MT1-MMP and EMPRIN in T2-T4 stages suggested their possible role in MMP-2 activation. Over expression Integrin αVβ3 in tumors than adjacent normal breast tissues was an indication of cancer progression with involvement of integrin signaling. We conclude that, the co-precipitation of MMP-2 with αvβ3 by anti-αv antibody is a strong indication that integrin αvβ3 is a surface receptor for MMP-2 and αvβ3-MMP-2 complex on the surface of tumor cells may play a very important role in determining the invasive property and malignant behavior of tumor tissues. The positive expression of endogenous inhibitor of MMP-2, TIMP-2 may have an appreciable role in activation of this protease and risk of malignancy in advanced stage of the disease. The enhanced expression of MT1-MMP and EMPRIN suggested a role for these factors in gelatinase regulation. However the exact mechanism(s) remains to be investigated. Finally, evaluation of integrin αVβ3 associated MMP-2 expression and activity may add valuable information and can possibly be therapeutic target. The clinical exploitation of integrins will provide oncologists with novel therapeutic strategies for the treatment of malignancy in breast cancer.

关键词： Breast Cancer MMP-2 Alpha V Beta3 MT1-MMP TIMP-2 EMPRIN VEGF

Uncertainty Theory Based Novel Multi-Objective Optimization Technique Using Embedding Theorem with Application to R &D Project Portfolio Selection

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics 2010年第3期1卷 189-199页

作者： Rupak Bhattacharyya amitava chatterjee Samarjit Kar 不详

This paper introduces a novice solution methodology for multi-objective optimization problems having the coefficients in the form of uncertain variables. The embedding theorem, which establishes that the set of uncertain variables can be embedded into the Banach space C[0, 1] × C[0, 1] isometrically and isomorphically, is developed. Based on this embedding theorem, each objective with uncertain coefficients can be transformed into two objectives with crisp coefficients. The solution of the original m-objectives optimization problem with uncertain coefficients will be obtained by solving the corresponding 2 m-objectives crisp optimization problem. The R & D project portfolio decision deals with future events and opportunities, much of the information required to make portfolio decisions is uncertain. Here parameters like outcome, risk, and cost are considered as uncertain variables and an uncertain bi-objective optimization problem with some useful constraints is developed. The corresponding crisp tetra-objective optimization model is then developed by embedding theorem. The feasibility and effectiveness of the proposed method is verified by a real case study with the consideration that the uncertain variables are triangular in nature.

关键词： Uncertainty Theory Uncertain Variable Embedding Theorem α-Optimistic and α-Pessimistic Value R & D Project Portfolio Selection

MMP-2 Inhibitory Activity of PBS Extract of Guava Leaves

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

American Journal of Plant Sciences 2021年第12期12卷 1761-1767页

作者： Atanu Mondal Ramanuj Mukherjee Subhajit Mondal amitava chatterjee Ramakrishna Mission Vivekananda Educational & Research Institute Kolkata India R G Kar Medical College Kolkata India

PBS (Phosphate Buffed Saline), pH 7.4 extract of Guava leaves (Psidium guajava L.) inhibits the active MMP-2 like molecule both of plant origin as well as active MMP-2 of human (breast cancer patients’ saliva) origin. The zymogram and ELISA were developed of different samples following standard methods. The isolation and identification of the new MMP-2 inhibitor(s) for its molecular characterization is under investigation.

关键词： MMP-2 Inhibitor Guava Leaves Cancer

Salivary Active MMP-2 of Breast Cancer Patients Is Inhibited by Guava Leaves PBS Extract

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

American Journal of Plant Sciences 2022年第5期13卷 650-658页

作者： Ramanuj Mukherjee Syandan Sinha Ray Subhajit Mondal amitava chatterjee R G Kar Medical College Kolkata India Ramakrishna Mission Vivekananda Educational & Research Institute Kolkata India

Matrixmetalloproteinase-2 (MMP-2), also called gelatinase-A, is a 72 Kd protein present in chromosome 16 in human. It is a zinc binding protein, responsible for the degradation of Extra Cellular Matrix (ECM) in normal physiological as well as disease processes like arthritis and cancer. It has a specific role in the cancer development and angiogenesis. MMP-2 contributes to cell migration. MMPs are the key to normal development as well as in the pathology of cancer and other inflammatory diseases. The inhibitors of MMP-2 activity are very important in maintaining the normal activity of MMP-2 and have an important role in the management of cancer. Regulation of MMP-2 activity is done by inhibitors like, TIMPs. In this report, we are discussing about a possible inhibitor(s) present in the PBS extract of guava leaves, inhibiting the active MMP-2 present in the saliva of breast cancer patients.

关键词： MMP-2 Inhibitor Saliva Breast Cancer

Tile Drainage and Nitrogen Fertilizer Management Influences on Nitrogen Availability, Losses, and Crop Yields

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Soil Science 2015年第10期5卷 211-226页

作者： Rakesh Awale amitava chatterjee Hans Kandel Joel K. Ransom Soil Science North Dakota State University Fargo ND USA Plant Sciences North Dakota State University Fargo ND USA

Installing tile drainage facilitates early planting and field operations, and tiling has tremendously increased in the Red River Valley (RRV) due to recent wet cycles. This experiment studied tile drainage and N-fertilizer management effects on N availability, N losses, and yields of corn (Zea mays L.) and sugarbeet (Beta vulgaris L.) in a naturally poorly-drained Fargo soil during the 2012-2013 growing seasons. Regardless of drainage, applying 146 kg N ha-1 with nitrapyrin resulted similar soil N availability to 180 kg N ha-1 without nitrapyrin in sugarbeet in both years. In corn, application of nitrapyrin resulted either higher or similar soil N levels to split-N application. In 2013, application of urea alone increased soil N availability during the early corn growing season under the undrained condition, whereas nitrapyrin delayed N release in the tile-drained soils. Corn and sugarbeet yields averaged 7.4 and 47.0 Mg·ha-1 in 2012, and averaged 8.3 and 38.3 Mg·ha-1 in 2013, respectively, with no significant differences among N-sources. However, corn yield increased on an average by 27.6% with N-fertilizer application over unfertilized control in 2013. In 2012, sugarbeet root impurity (% sucrose loss to molasses) increased by 13.8% and 17.2% with 146 kg N ha-1 plus nitrapyrin and 180 kg N ha-1 treatments, respectively, compared to unfertilized control. Besides, higher N rates were usually associated with greater daily soil N2O emissions, with the maximum flux of 105 g N2O-N ha-1·d-1 recorded under corn. Addition of fertilizer-N increased NH3 volatilization losses up to 1.9% and 0.5% of the applied-N in corn and sugarbeet, respectively. Tile drainage influenced soil N availability more than crop yield during two years of study. Nitrogen management can have pronounced effects on N availability and losses. A long-term study is needed to investigate the fertilizer-N use efficiency of crops under tile drainage condition.

关键词： Subsurface Drainage Nitrogen Nitrous Oxide Ammonia Volatilization Nitrate Leaching