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Effect of inorganic arsenic in paddy soil on the migration and transformation of selenium species in rice plants

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Journal of Environmental Sciences 2024年第9期143卷 35-46页

作者： Ganga raj.pokhrel Kaiteng Wang Kaiyang Ying Yongchen Wu Ze Wang Xi Zhu Can Qu Hong Li Fengfu Fu Guidi Yang Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring Key Laboratory for Medicinal Plant Chemistry and Chemical BiologyCollege of JunCao Science and EcologyFujian Agriculture and Forestry UniversityFuzhou 350002China Department of Chemistry Birendra Multiple CampusTribhuvan UniversityChitwan 00977-44200BharatpurNepal Key Laboratory for Analytical Science of Food Safety and Biology of Ministry of Education Fujian Provincial Key Lab of Analysis and Detection for Food SafetyCollege of ChemistryFuzhou UniversityFuzhou 350116China

Selenium(Se)in paddy rice is one of the significant sources of human Se ***,the effect of arsenic(As)pollution in soil on the translocation of Se species in rice plants is *** this research,a pot experiment was designed to examine the effect of the addition of 50 mg As/kg soil as arsenite or arsenate on the migration of Se species from soil to indica Minghui 63 and *** results showed that the antagonism between inorganic As and Se was closely related to the rice cultivar and Se oxidation state in *** to the standalone selenate treatment,arsenite significantly(p<0.05)decreased the accumulation of selenocystine,selenomethionine and selenate in the roots,stems,sheaths,leaves,brans and kernels of both cultivars by 21.4%-100.0%,40.0%-100.0%,41.0%-100%,5.4%-96.3%,11.3%-100.0% and 26.2%-39.7% respectively,except for selenocystine in the kernels of indica Minghui 63 and selenomethionine in the leaves of indica Minghui 63 and the stems of indica *** also decreased(p<0.05)the accumulation of selenocystine,selenomethionine and selenate in the roots,stems,brans and kernels of both cultivars by 34.9%-100.0%,30.2%-100.0%,11.3%-100.0% and 5.6%-39.6%respectively,except for selenate in the stems of indica Minghui ***,relative to the standalone selenite treatment,arsenite and arsenate decreased(p<0.05)the accumulation of selenocystine,selenomethionine and selenite only in the roots of indica Minghui 63 by 45.5%-100.0%.Our results suggested that arsenite and arsenate had better antagonism toward Se species in selenate-added soil than that in selenite-added soil;moreover,arsenite had a higher inhibiting effect on the accumulation of Se species than arsenate.

关键词： Rice(Oryza sativa L.) Inorganic arsenic Selenium species Translocation Antagonistic effect

Cybersecurity: A Stochastic Predictive Model to Determine Overall Network Security Risk Using Markovian Process

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Journal of Information Security 2017年第2期8卷 91-105页

作者： nawa raj.pokhrel Chris P. Tsokos Department of Mathematics and Statistics University of South Florida Tampa USA

There are several security metrics developed to protect the computer networks. In general, common security metrics focus on qualitative and subjective aspects of networks lacking formal statistical models. In the present study, we propose a stochastic model to quantify the risk associated with the overall network using Markovian process in conjunction with Common Vulnerability Scoring System (CVSS) framework. The model we developed uses host access graph to represent the network environment. Utilizing the developed model, one can filter the large amount of information available by making a priority list of vulnerable nodes existing in the network. Once a priority list is prepared, network administrators can make software patch decisions. Gaining in depth understanding of the risk and priority level of each host helps individuals to implement decisions like deployment of security products and to design network topologies.

关键词： Vulnerability Attack Graph Markov Model Exploitability CVSS FIRST NVD IDS

Cybersecurity: Time Series Predictive Modeling of Vulnerabilities of Desktop Operating System Using Linear and Non-Linear Approach

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Journal of Information Security 2017年第4期8卷 362-382页

作者： nawa raj.pokhrel Hansapani Rodrigo Chris P. Tsokos Department of Mathematics and Statistics University of South Florida Tampa FL USA School of Mathematical and Statistical Sciences University of Rio Grande Valley Edinburg TX USA

Vulnerability forecasting models help us to predict the number of vulnerabilities that may occur in the future for a given Operating System (OS). There exist few models that focus on quantifying future vulnerabilities without consideration of trend, level, seasonality and non linear components of vulnerabilities. Unlike traditional ones, we propose a vulnerability analytic prediction model based on linear and non-linear approaches via time series analysis. We have developed the models based on Auto Regressive Moving Average (ARIMA), Artificial Neural Network (ANN), and Support Vector Machine (SVM) settings. The best model which provides the minimum error rate is selected for prediction of future vulnerabilities. Utilizing time series approach, this study has developed a predictive analytic model for three popular Desktop Operating Systems, namely, Windows 7, Mac OS X, and Linux Kernel by using their reported vulnerabilities on the National Vulnerability Database (NVD). Based on these reported vulnerabilities, we predict ahead their behavior so that the OS companies can make strategic and operational decisions like secure deployment of OS, facilitate backup provisioning, disaster recovery, diversity planning, maintenance scheduling, etc. Similarly, it also helps in assessing current security risks along with estimation of resources needed for handling potential security breaches and to foresee the future releases of security patches. The proposed non-linear analytic models produce very good prediction results in comparison to linear time series models.

关键词： ARIMA NVD ANN OS SVM CVE SMAPE

一种尼泊尔传统豆荚发酵食品Masyaura的感官、生化与营养特征(英文)

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食品科学 2006年第9期27卷 62-68页

作者： nawa raj Dahal 李崎顾国贤江南大学教育部工业生物技术重点实验室江苏无锡214036

Masyaura是尼泊尔出产的一种以豆荚为原料的发酵食品,可以采用传统日光自然干燥以及控制发酵、机械干燥的方法生产,通过感官、生化和营养特征进行评价。结果表明采用控制发酵、机械干燥方式生产的Masyaura,质地脆,密度低,感官评价优于... 详细信息

Masyaura是尼泊尔出产的一种以豆荚为原料的发酵食品,可以采用传统日光自然干燥以及控制发酵、机械干燥的方法生产,通过感官、生化和营养特征进行评价。结果表明采用控制发酵、机械干燥方式生产的Masyaura,质地脆,密度低,感官评价优于自然发酵的产品。对2种方式生产的产品进行了蛋白质和淀粉的体外消化试验,在自然干燥或控制发酵、机械干燥的Masyaura中,含硫氨基酸都是第一限制性氨基酸。

关键词： Masyaura 感官特征生化评价营养评价控制发酵日光干燥尼泊尔

Assessment of Heavy Metals in Deep Groundwater Resources of the Kathmandu Valley, Nepal

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Journal of Environmental Protection 2016年第4期7卷 516-531页

作者： Suman Man Shrestha Kedar Rijal Megh raj.pokhrel Central Department of Environmental Science Tribhuvan University Kirtipur Nepal Central Department of Chemistry Tribhuvan University Kirtipur Nepal

A study was carried out to address distribution of some heavy metals in deep groundwater resources of the Kathmandu Valley. Groundwater samples were analyzed for pH, ORP, EC, iron, manganese, zinc, and arsenic in 41 deep groundwater wells during pre monsoon and post monsoon seasons for two consecutive years. The study showed elevated concentrations of iron and manganese in the groundwater of the valley. The occurrence of elevated concentrations of arsenic was also exhibited and observed up to 0.160 mg/L. The spatial distribution patterns demonstrated elevated levels of EC, iron, manganese, zinc, and arsenic in central groundwater district (CGWD) of the valley. The monitored parameters except ORP are not significantly correlated with studied time series, inferring similar distribution of the metals. Correlation analysis and principal component analysis (PCA) were performed to find out relationships among examined parameters and metals. The ORP has strong negative correlations with iron, manganese, and arsenic, suggesting reductive mobilization mechanism of the metals in the groundwater. PCA results showed that iron and manganese with high positive loading factors were due to common natural source of origin of these metals in the groundwater, while negative loading factors of pH and ORP indicated that iron and manganese mobilization was favorable in low pH and reducing environment. Cluster analysis (CA) evidenced high mineralization in most of the wells in the CGWD.

关键词： Heavy Metals Deep Groundwater Principal Component Analysis Cluster Analysis Mineralization

Assessment of Arsenic Contamination in Deep Groundwater Resources of the Kathmandu Valley, Nepal

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Journal of Geoscience and Environment Protection 2015年第10期3卷 79-89页

作者： Suman Man Shrestha Kedar Rijal Megh raj.pokhrel Central Department of Environmental Science Tribhuvan University Kirtipur Kathmandu Nepal Central Department of Chemistry Tribhuvan University Kirtipur Kathmandu Nepal

This study was carried out to assess arsenic in deep groundwater resources in the Kathmandu Valley, Nepal and to predict arsenic mobilization process in relation to iron, manganese, pH and ORP. Forty-one deep groundwater samples were collected during pre monsoon and post monsoon in 2013. The depths of the wells were ranged from 84 to 304 m. In pre monsoon and post monsoon, arsenic concentration in 17% and 26% of examined groundwater wells, respectively exceeded permissible World Health Organization (WHO) guideline value of 0.010 mg/L for drinking water. The concentrations of arsenic were in the range between < 0.003 to 0.137 mg/L. The study demonstrated elevated concentrations of iron and manganese in the groundwater. Arsenic is highly correlated with iron and manganese. The strong negative correlation between arsenic and ORP indicates that arsenic mobilization occurs under reducing condition. These distinct relationships indicate that arsenic release is considered to be affected by the reductive dissolution of Fe/Mn oxides in the groundwater. Arsenic has very weak negative correlation with pH suggesting less effect of pH on arsenic mobilization. Arsenic is not significantly correlated with the season which infers similar distribution of arsenic in both seasons. Arsenic varies spatially in groundwater of the valley showing high concentrations in central groundwater district.

关键词： Arsenic Deep Groundwater Reductive Dissolution Kathmandu Valley

一种基于豆荚的尼泊尔传统发酵食品Masyaura的发酵和营养评价研究

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一种基于豆荚的尼泊尔传统发酵食品Masyaura的发酵和营养评价研究

作者： nawa raj Dahal 江南大学

学位级别：硕士

在全世界包括尼泊尔,传统食品在人们的生活中处于重要地位。Masyaura是尼泊尔的一种基于豆荚的、含蛋白质丰富的发酵食品。使用黑鹰嘴豆和芋头,通过传统的日光干燥制作Masyaura,目前正在研究用受控发酵和机械干燥技术进行代替。在制作Ma... 详细信息

在全世界包括尼泊尔,传统食品在人们的生活中处于重要地位。Masyaura是尼泊尔的一种基于豆荚的、含蛋白质丰富的发酵食品。使用黑鹰嘴豆和芋头,通过传统的日光干燥制作Masyaura,目前正在研究用受控发酵和机械干燥技术进行代替。在制作Masyaura中,也使用Pediococcus pentaseceous占主导的乳酸菌、酵母Saccharomyces cerevisiae和霉菌Aspergillus niger。在发酵过程评价生化、微生物和物理化学特征。各种不同的发酵方法生产Masyaura,也通过感官、营养和抗营养特征进行评价。也进行研究了Masyaura的有机酸、挥发性化合物、多酚和抗氧化特征。还进行黑鹰嘴豆含量和Masyaura的蛋白质和营养评价的关系的基础研究。在黑鹰嘴豆浸泡过程,生化参数如酸度、可溶性蛋白质、氨基酸、游离糖和还原糖增加而pH降低。在发酵中,酸度、可溶性蛋白质、氨基氮增加而糖明显降低。可能由于霉菌的活性,发酵时间较长造成酸度降低而pH升高。在这个过程中,微生物菌群中特别占优势的乳酸菌增加。比日光干燥Masyaura相比,受控发酵和机械干燥方法导致Masyaura口感更佳、营养更丰富。在制备Masyaura时,30℃/24h、相对湿度80-90%时,看来发酵条件更好,然后50℃干燥12-16h。和受控发酵Masyaura相比,日光干燥质地和密度要更好。和受控发酵Masyaura相比,在发酵过程接种Saccharomyces cerevisiae提高Masyaura的感官质量。接种Pediococcus pentaseceous没有影响感官质量。接种Aspergillus niger造成Masyaura的感官质量变的很差,难以接受。在灭菌底物上分别单独接种Saccharomyces cerevisiae和Pediococcus pentaseceous,并不提高感官特征。可以认为乳酸菌和酵母的混合培养是适当的发酵微生物。 Masyaura的蛋白质（21.4-22.4%）和动物蛋白质相当,糖（60.6-64.7%）和矿物质（4.9-5.2%）,特别是钾、钙、磷酸盐和镁的很好来源。主要的B族维生素是VB1、核黄素、VB6、VB2和VB12。发现全部B族维生素的质量比原料中要高。淀粉是主要的糖从46.5到56.1%,还有游离糖（5.3-6.8）和还原糖（0.8-1.9）。有机酸结果表明采用日光干燥技术生产Masyaura,乙酸是主要的有机酸。在受控发酵和机械干燥Masyaura中,乙酸比例要低,而同时乳酸和柠檬酸增加。采用不同方法制备的Masyaura,检测出很多种类（31-55）和数量（占总挥发酸23.4-65.3%）的烃。在Masyaura中,检测出醛（0.9-4.9%）、酯（2.1-2.3%）、酸（3.4-20.1%）、醇（1.1-6.1%）和吡嗪（0.3-10.2%）。发现Masyaura的总必需氨基酸占总氨基酸的31.7-38.3%。在Masyaura中,含硫氨基酸是限制性氨基酸。总游离氨基酸在5.1-13.1%。在发酵过程中,热稳定性反营养物质草酸盐和植酸盐降低。和原料相比,样品中钙和锌的生物利用度要高。和原材料相比,由于蛋白质和淀粉的消化性,Masyaura的营养质量提高。 Masyaura的总多酚含量在235.2-351.9mg/100g,其数值低于原料。芋头表明有较高的反营养活性。Masyaura也有反营养特征。和日光干燥相比,受控发酵的Masyaura脂肪吸收和重组特征要高。油煎降低重组能力。和原料一样,球蛋白和清蛋白是蛋白质的主要组分。清蛋白的营养质量要优于球蛋白。SDS-PAGE研究Masyaura的球蛋白和清蛋白表明,原料的主要蛋白质组分分解、分子量降低,也反映改善了蛋白质的消化性。这可能由于发酵时发生酶水解。总之,受控发酵和机械干燥Masyaura中,在物理性和感官上都要优于日光干燥的Masyaura,更卫生和保证质量。营养上可以和日光干燥的Masyaura媲美。乳酸菌和酵母是理想的微生物菌群。Masyaura的营养质量、矿物质的生物利用度和营养消化特征要优于原料。受控发酵和机械干燥方法可以商业化应用。从感官上进一步调查混合培养对的营养,Masyaura的生化和营养特征也值得推荐。

关键词：生化评价微生物评价营养评价反营养特征生物利用度消化性发酵食品尼泊尔

Surface Modification of the Biowaste for Purification of Wastewater Contaminated with Toxic Heavy Metals—Lead and Cadmium

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Advances in Chemical Engineering and Science 2013年第3期3卷 178-184页

作者： Bindra Shrestha Jagjit Kour Puspa Lal Homagai Megh raj.pokhrel Kedar Nath Ghimire Central Department of Chemistry Tribhuvan University Kathmandu Nepal

The surface of a biowaste was modified by introduction of amino group for the purification of wastewater contaminated with heavy metals. In this study waste tea leaf was used as a biowaste which was an economic and efficient bioadsorbent. The aminated tea leaves were characterized by spectral and elemental analysis. The adsorption capacity of the surface modified biosorbent was studied as the function of solution pH, concentration of metal ions and contact time of adsorption. The applicability of Langmuir isotherm was tested. The adsorption capacities were found to be 83.04 mg/g and 57 mg/g for Pb (II) and Cd (II), respectively. The biosorbent was regenerated by desorption of the metal loaded adsorbent with 0.1 M HNO3. These results showed that the aminated tea leaves may be an attractive alternative for treatment of wastewater contaminated with heavy metals.

关键词： Bioadsorbent Heavy Metals Wastewater Amination Langmuir Isotherm

Innovative Practices for the Promotion of Local/Indigenous Knowledge for Disaster Risk Reduction Management in Sudur Paschim Province,Nepal

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Journal of Geographical Research 2021年第3期4卷 1-11页

作者： Kabi Prasad pokhrel Shambhu Prasad Khatiwada Narayan Prasad Paudyal Keshav raj Dhakal Chhabi Lal Chidi Narayan Prasad Timilsena Dhana Krishna Mahat Central Department of Geography Education Tribhuvan UniversityKathmanduNepal Central Department of Geography Tribhuvan UniversityKathmanduNepal Central Department of Science Education Tribhuvan UniversityKathmanduNepal PhD Research Scholar of Geography Education Tribhuvan UniversityKathmanduNepal

This study is an attempt to point out the different types of natural hazards in Sudur Paschim province of Nepal where environmental degradation processes such as deforestation,desertification,biodiversity loss,soil crisp and watershed degradation are rising *** participatory method multi hazard prone areas were identified with type and *** criteria evaluation method was applied to prioritize replicable actions with location-specific innovative practices and their legitimization for integrating local and indigenous knowledge into mainstream education,science and policy with a view to incorporate local and indigenous knowledge as live science in disaster and climate change *** of the study reveal that varieties of natural hazards in combination with social factors such as poverty,conflict and inequality have resulted frequent disasters and social vulnerabilities in many parts of the ***,indigenous and local people have responded threats of multi hazards by using their traditional knowledge and skills which has evolved over generations,and continue to adapt to future *** traditional,often faith-based,beliefs and practices were found to use as the key to their resilience in the face of natural ***,many communities have been lost their knowledge as the elderly die without transferring it to younger *** this proper educational policy and strategic development plans have not been implemented to cope local/indigenous knowledge into *** of the study indicate that indigenous and local knowledge is a precious province resource that can support the process of disaster prevention,preparedness and response in cost-effective disaster risk ***,policy framework has to prime focus to integrate indigenous and local knowledge,wisdom and skills into mainstream educational programs in order to transfer science into policy and education(words)into practice.

关键词： Multihazard Indigenous knowledge Location-specific Innovative practice Indigenous communities Science to policy