Irrigation of paddy fields to arsenic (As) containing groundwater leads to As accumulation in rice grains and causes serious health risk to the people worldwide. To reduce As intake via consumption ...of contaminated rice grain, identification of the mechanisms for As accumulation and detoxification in rice is a prerequisite. Herein, we report involvement of a member of rice NRAMP (Natural Resistance‐Associated Macrophage Protein) transporter, OsNRAMP1, in As, in addition to cadmium (Cd), accumulation through expression in yeast and Arabidopsis. Expression of OsNRAMP1 in yeast mutant (fet3fet4) rescued iron (Fe) uptake and exhibited enhanced accumulation of As and Cd. Expression of OsNRAMP1 in Arabidopsis provided tolerance with enhanced As and Cd accumulation in root and shoot. Cellular localization revealed that OsNRAMP1 resides on plasma membrane of endodermis and pericycle cells and may assist in xylem loading for root to shoot mobilization. This is the first report demonstrating role of NRAMP in xylem mediated loading and enhanced accumulation of As and Cd in plants. We propose that genetic modification of OsNRAMP1 in rice might be helpful in developing rice with low As and Cd content in grain and minimize the risk of food chain contamination to these toxic metals.
Arsenic (As) is a highly toxic environmental pollutant which accumulates in rice grain and causes chronic and epidemic effects on human health. We report role of rice NRAMP (Natural Resistance‐Associated Macrophage Protein) transporter, OsNRAMP1, in As, in addition to cadmium (Cd), accumulation through expression in yeast and Arabidopsis. Cellular localization revealed that OsNRAMP1 resides on plasma membrane of endodermis and pericycle cells and may assist in xylem loading for root to shoot mobilization. This is the first report demonstrating role of NRAMP in xylem mediated loading and enhanced accumulation of As and Cd in plants.
•Microbial consortium of P. putida and C. vulgaris improved the growth and reduced arsenic induced oxidative stress in rice.•The consortium reduced the accumulation of arsenic and also improved the ...level of nutrient elements in rice.•Reduced arsenic in rice due to the consortium alleviated the requirement of thiols and antioxidant enzymes.
In the present study, arsenic (As) toxicity amelioration potential of a consortium of plant growth promoting rhizobacterium (Pseudomonas putida) and alga (Chlorella vulgaris) was evaluated during arsenate (AsV) exposure to rice (Oryza sativa) plants for 15 d. The consortium mediated amelioration of As toxicity was evident through improved growth of rice plants (root and shoot length and biomass) and reduced oxidative stress as level of superoxide radicals (O2−), hydrogen peroxide (H2O2) and membrane damage. The positive responses were attributable to a significant decline in As accumulation in root (94 mg kg−1 dw) and shoot (51 mg kg−1 dw) in consortium (P. putida + C. vulgaris) inoculated seedlings as compared to As alone exposed plants (156 and 98 mg kg−1 dw, respectively). There were also significant changes in the level of various nutrient elements (Mn, Fe, Co, Zn, Mo and Cu), thiols and in the activities of antioxidant and thiol metabolism enzymes in the consortium inoculated seedlings that allowed the plants to tolerate As stress effectively and achieve better growth. The study demonstrated that consortium of P. putida and C. vulgaris may alleviate As stress and improve growth of rice seedlings along with reduction in As levels.
With the emergence of the web, traditional learning has changed significantly. Hence, a huge number of ‘e-learning systems' with the advantages of time and space have been created. Currently, many ...e-learning systems are being used by a large number of academic institutions worldwide which allow different users of the system to perform various tasks based on their goals. However, most of these systems follow a ‘one size fits all' approach where same resources are offered to learners irrespective of their unique learning requirements. Therefore, personalization is required as a part of e-learning systems which offers resources to learners based on their profile. This research aims to perform cluster analyses in order to validate clusters created through a k-means algorithm. The clusters will be used to classify a new learner into its appropriate class and recommend relevant courses. Finally, the accuracy of the recommendation is evaluated using various evaluation metrics. The proposed recommendation system helps learners to improve their academic performance and hence overall learning process as well.
Arsenic (As) contamination in rice leads to yield decline and causes carcinogenic risk to human health. Although the role of nitric oxide (NO) in reducing As toxicity is known, NO-mediated genetic ...modulation in the plant during arsenic toxicity has not yet been established. We analyzed the key components of NO metabolism and the correlations between NO interaction and arsenic stress using rice as a relevant model plant. Illumina sequencing was used to investigate the NO-mediated genome-wide temporal transcriptomic modulation in rice root upon AsIII exposure during 12 days (d) of the growth period. Sodium nitroprusside (SNP) was used as NO donor. SNP supplementation resulted in marked decrease in ROS, cell death and As accumulation during AsIII stress. NO was found to modulate metal transporters particularly NIP, NRAMP, ABC and iron transporters, stress related genes such as CytP450, GSTs, GRXs, TFs, amino acid, hormone(s), signaling and secondary metabolism genes involved in As detoxification. We detected NO-mediated change in jasmonic acid (JA) content during AsIII stress. The study infers that NO reduces AsIII toxicity through modulating regulatory networks involved in As detoxification and JA biosynthesis.
Information retrieval (IR) is the science of identifying documents or sub-documents from a collection of information or database. The collection of information does not necessarily be available in ...only one language as information does not depend on languages. Monolingual IR is the process of retrieving information in query language whereas cross-lingual information retrieval (CLIR) is the process of retrieving information in a language that differs from query language. In current scenario, there is a strong demand of CLIR system because it allows the user to expand the international scope of searching a relevant document. As compared to monolingual IR, one of the biggest problems of CLIR is poor retrieval performance that occurs due to query mismatching, multiple representations of query terms and untranslated query terms. Query expansion (QE) is the process or technique of adding related terms to the original query for query reformulation. Purpose of QE is to improve the performance and quality of retrieved information in CLIR system. In this paper, QE has been explored for a Hindi-English CLIR in which Hindi queries are used to search English documents. We used Okapi BM25 for documents ranking, and then by using term selection value, translated queries have been expanded. All experiments have been performed using FIRE 2012 dataset. Our result shows that the relevancy of Hindi-English CLIR can be improved by adding the lowest frequency term.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Cross-lingual information retrieval (CLIR) is a challenging task that requires overcoming linguistic barriers to match user queries with relevant documents in different languages. One of the major ...challenges in CLIR is the lack of parallel corpora, which hinders the development of effective translation models. This challenge can be addressed using snippets as a dataset to train CLIR models. Snippets can be automatically extracted from various sources, such as search engine result pages and can provide a rich and diverse set of collections for cross-lingual information retrieval. This paper initially discusses the challenges in CLIR and then explores the use of snippets as a dataset which can lead towards the development or improvements in the techniques to improve the retrieval effectiveness and further discusses the advantages and limitations of using snippets dataset in CLIR.
Arsenic (As), a toxic metalloid, is finding its route to human through intake of As-contaminated water and consumption of food grown on contaminated soil. Rice is the most As-affected crop. Present ...study is aimed to assess the impact of stabilized orthosilicic acid (a proprietary formulation for plant-available silicon (Si) and earlier used as fertilizer for rice to enhance growth and yield) in reducing the accumulation of As in rice grains. Application of arsenic in the form of arsenate (As
V
) and arsenite (As
III
) significantly affected plant growth in a dose-dependent manner. Higher doses of As
V
and As
III
(50 and 25 mg L
−1
respectively) significantly decreased the yield attributes leading to lower yield. A significant accumulation of As in grain was observed in both As
V
- and As
III
-exposed plants in a dose-dependent manner. Arsenic exposure also increased the level of Si in rice grains. Application of Si, either in soil or on leaves (foliar), greatly reduced grain As accumulation (up to 67% in As
V
and 78% in As
III
) and enhanced the growth and yield of plants under As stress. The level of thiols and activities of antioxidant enzymes were also enhanced under Si application. Foliar Si application was more effective in increasing grain Si level and reducing grain As than soil Si. The level of other trace elements was also significantly enhanced by Si application irrespective of the presence or absence of As in comparison with control. Arsenic exposure constrained some of the trace elements, such as Zn and Co, which were restored by Si application. Results of the present study showed that the application of currently used Si formulation may effectively reduce grain As level even in highly As-contaminated soil and improve grain quality of rice.
One of the most important purposes of e-Governance is to increase the satisfaction level of citizens. A single window system often helps in great way to access various government services. However, ...many e-Governance portals lack in integration and interoperability. Often individual state/local governments use their own portal for providing various e- services to its citizens which at times require integration and coordination with similar portals of other states for the information sharing. Lack of this feature restricts the usages of services. The realization towards this came from our previous case studies of two such portals (namely SPST and Jansunwai) of the state of Uttar Pradesh to understand the issues therein. This paper presents a general framework and guidelines for e-Governance which may be considered for implementation to overcome the existing limitations identified during the period of this study and research. The roadmap shown can improve the services, scope and functionality of certain portals. Central to this skeleton is the interconnection and integration of similar e-services being offered by different government in the country.
Arsenic (As) contamination of water is a global concern and rice consumption is the biggest dietary exposure to human posing carcinogenic risks, predominantly in Asia. Sulfur (S) is involved in ...di-sulfide linkage in many proteins and plays crucial role in As detoxification. Present study explores role of variable S supply on rice leaf proteome, its inclination towards amino acids (AA) profile and non protein thiols under arsenite exposure. Analysis of 282 detected proteins on 2-DE gel revealed 113 differentially expressed proteins, out of which 80 were identified by MALDI-TOF-TOF. The identified proteins were mostly involved in glycolysis, TCA cycle, AA biosynthesis, photosynthesis, protein metabolism, stress and energy metabolism. Among these, glycolytic enzymes play a major role in AA biosynthesis that leads to change in AAs profiling. Proteins of glycolytic pathway, photosynthesis and energy metabolism were also validated by western blot analysis. Conclusively S supplementation reduced the As accumulation in shoot positively skewed thiol metabolism and glycolysis towards AA accumulation under AsIII stress.
Toxic metal(loid) contamination of soil and sediment poses long term risk to soil and human health through plant-human or plant-animal-human food chain pathways. Iron plaque (IP) formation is ...frequent in aquatic and wetland plant species and is responsible for the sequestration of various metal(loids). The presence of IP may act as a buffer or barrier and may thus enhance or reduce the uptake of potentially phytotoxic metals and metalloids by plants. If IP acts as a barrier, then low IP producing macrophytes/aquatic plants may be better accumulators of toxic metals and may find use in constructed wetlands for remediation of pollutants, while high IP forming edible plant species could be safer for human consumption. Conversely, if IP acts as a buffer for mineral nutrients and toxic elements then those cultivars may be rich in nutrients, but may also cause toxicity. However, an ecotoxicological risk is also inevitable if IP rich macrophyte roots containing heavy metals are consumed by herbivores. In this review, we summarize the current understanding about the role of IP in metal and metalloid sequestration, uptake, and transport. Furthermore, we will address the role of root IP in Oryza sativa for arsenic (As) sequestration leading to lower grain As translocation, reducing the risk of human exposure.
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