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1.
J Environ Manage ; 298: 113423, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34526286

RESUMO

The Yellow River, with a developmental and historical significance to China, is now facing several emerging pressures, which are degrading the river status and creating challenges for high-quality development in the basin. Numerous studies on such emerging pressures, present scattered outcomes, and trigger uncertainties and deficient assumptions on the river's problems. This review integrated such scattered information and investigated the emerging pressures, their drivers and integrated impacts at the basin level. The study intended to prioritize those pressures needing expeditious consideration, and carried a discussion on the alternative pathways to the solution. To determine the critical emerging pressures, a literature review was conducted and experts' opinion was sought. The outcome further led to a comprehensive review, data collection, and analysis of three groups of emerging pressures. The review recognized 'Water Stress' in the lower reach, primarily caused by an abated flow, as the most distressing emerging pressure inflicting social, ecological, and economic consequences. Such decline in flow was mostly induced by a recent increase in 'Anthropogenic activities', such as intensive water withdrawal for irrigation (≥27 BCM), and construction of check dams in the Loess Plateau region (trapping~5 BCM water). The increasing 'Pollution' in the river, besides threatening public health and ecology, also contributed to the water stress by rendering certain stretches of the river biologically dead and unsuitable for any use. The 'Climate Change', with its key negative effect on precipitation in the middle sub-basin, overall contributed small (8-11 %) to the observed reduction in river flow. With increasing challenges for the adopted engineering solutions tackling the water stress, the study suggested the use of a demand management approach, employing adaptive policy measures, as an alternative or supplementary solution to the current approach. In addition, the study highlights that regular reviewing and reforming the key decisions based on evidence and updated information, and taking a participatory approach, may offer a sustainable pathway to the environment as well as socio-economic goals.


Assuntos
Rios , Movimentos da Água , Mudança Climática , Ecologia , Água
2.
Ecotoxicol Environ Saf ; 196: 110498, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32247957

RESUMO

Two arsenic (As) hyper-tolerant bacterial strains NM01 Paracoccus versutus and NM04 Aeromonas caviae were isolated from As polluted site of West Bengal, India. The strains not only possess the potential to tolerate up to 20,000 mgl-1 As(V) and 10,000 mgl-1 As(III) but also possess plant growth promoting (PGP) traits like phosphate solubilization, siderophore production, IAA production. Greenhouse pot experiments were conducted to assess the effect of rhizospheric inoculation of both the strains individually and in consortia in As accumulation by Adiantum capillus-veneries. It was observed that the microbial inoculation significantly (p < 0.05) increased the synthesis of thiolic compounds and thus, enhanced As accumulation with translocation factor (TF) > 1. The strains regulated endogenous phytohormone up to 90% and 77.9% increase in auxin of consortia inoculated root and shoot, respectively. Interestingly, inoculation of the isolated strains augmented rhizospheric microbial diversity which was negatively affected by heavy metal. The results of high-throughput Illumina MiSeq sequencing technique to observe the composition of the bacterial community revealed 11,536 unique bacterial operational taxonomic units (OTUs) from As + S (non-inoculated), whereas 11,884 from Consortia As + S (inoculated) rhizospheric soil samples. Inoculated soil displayed higher bacterial diversity indices (ACE and Chao 1) with the dominant bacterial phyla Proteobacteria, Actinobacteria and Firmicutes. Our results highlight the innate PGP abilities of the strains and its potential to facilitate phytoextraction by enhancing As accumulation in the shoot.


Assuntos
Adiantum/metabolismo , Arsênio/metabolismo , Bactérias/metabolismo , Rizosfera , Poluentes do Solo/metabolismo , Adiantum/crescimento & desenvolvimento , Adiantum/microbiologia , Arsênio/análise , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Biodegradação Ambiental , Ácidos Indolacéticos/metabolismo , Microbiota/genética , Solo/química , Microbiologia do Solo , Poluentes do Solo/análise
3.
Environ Geochem Health ; 42(12): 4101-4111, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32060865

RESUMO

The presence of heavy metal in soil and water resources has serious impact on human health. The study was designed to examine the phytoremediation ability of plant species that are growing naturally on the Zn-contaminated site. For the study, six plant species and their rhizospheric soil as well as non-rhizospheric soil samples were collected from different parts of the industrial sites for chemical and biological characterization. Visual observations and highest importance value index (IVI) through biodiversity study revealed potential plants as effective ecological tools for the restoration of the contaminated site. Among the plants, almost all were the most efficient in accumulating Fe, Mn, Cu and Zn in its shoots and roots, while Cynodon dactylon, Chloris virgata and Desmostachya bipinnata were found to be stabilizing Cr, Pb and Cd (bioconcentration factor in root = 7.95, 6.28 and 1.98 as well as translocation factor = 0.48, 0.46 and 0.78), respectively. Thus, the results of this study showed that the naturally growing plant species have phytoremediation potential to remediate the electroplating wastewater-contaminated site. These plant species are successful phytoremediators with their efficient metal stabilizing and well-evolved tolerance to heavy metal toxicity.


Assuntos
Galvanoplastia , Metais Pesados/metabolismo , Plantas/metabolismo , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/metabolismo , Biodegradação Ambiental , Biodiversidade , Metais Pesados/análise , Raízes de Plantas/classificação , Raízes de Plantas/metabolismo , Plantas/classificação , Rizosfera , Poluentes do Solo/análise , Poluentes do Solo/metabolismo , Poluentes Químicos da Água/análise
4.
Ecotoxicol Environ Saf ; 182: 109462, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31351329

RESUMO

Wheat (W) and accumulators (A) were planted in plots (arsenic amended soil and without arsenic) designed with ecotoxicological concern for arsenic safe-grains. For the study sixteen plots of 2 × 2 × 0.5 m (l × b × h) size were prepared. Arsenic (As) in the form of sodium arsenate was applied at 50 mg/kg in plots. Out of these sixteen plots eight plots had arsenic amended soil and rest 8 without any arsenic (C). Accumulator's viz. Pteris vittata (PV), Phragmites australis (PA) and Vetiveria zizanioides (VZ) were planted along with wheat in combination (W + PV, W + PA and W + VZ) in twelve plots (6 AWAs plots and 6 AWC plots). In the rest 4 plots (2 WAs plots and 2 WC plots), only wheat was planted. The study was conducted for two cropping seasons, where accumulators were left in the plots between the cropping seasons except that before 2nd cropping accumulators were properly pruned and extra tillers were removed. The germination % of wheat in WAs in 1st and the 2nd cropping season was found to be 55 and 57%, while in AWAs and AWC plots it was between 86 and 92% (W + VZ, 56 and 73%). The physiological activity was found to be reduced in WAs plots compared to AWAs (except for vetiver combination) and AWC plots in both cropping seasons. The antioxidant activity was enhanced in WAs compared with AWAs. The arsenic concentration in grains of wheat was within the permissible limit set by WHO and GOI in AWAs plots while it exceeded the limit in W + VZ (in 1st cropping) and WAs in both cropings.


Assuntos
Antioxidantes/metabolismo , Arseniatos/análise , Poaceae/química , Pteris/química , Poluentes do Solo/análise , Triticum/química , Biodegradação Ambiental , Vetiveria/química , Vetiveria/crescimento & desenvolvimento , Poaceae/crescimento & desenvolvimento , Pteris/crescimento & desenvolvimento , Solo/química , Triticum/crescimento & desenvolvimento , Triticum/metabolismo
5.
J Environ Manage ; 231: 1211-1221, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30602246

RESUMO

Tree growth rate can complicate our understandings of plant belowground responses to elevated CO2 (eCO2) in tropical ecosystems. We studied the effects of eCO2 on plant growth parameters, and rhizospheric soil properties including soil organic carbon (SOC), glomalin related soil protein (GRSP), microbial biomass C (Cmic), CO2 efflux (Cefflux), and microbial extracellular enzyme activities under two tropical tree saplings of fast-growing Tectona grandis (Teak) and slow-growing Butea monosperma (Butea). We exposed these saplings to eCO2 (∼550 ppm) and ambient CO2 (aCO2; ∼395 ppm) in the Indo-Gangetic plain region, and further (after 10 and 46 months) measured the changes in their rhizospheric soil properties. With respect to aCO2 treatment, eCO2 significantly increased plant height, stem and shoot weight, and total plant biomass of Teak. However, these plant traits did not considerably differed between eCO2 and aCO2 treatments of Butea. The eCO2 induced greater extent of increase in rhizospheric soil properties including SOC fractions (particulate OC, non-particulate OC and total OC), GRSP fractions (easily extractable- GRSP, difficulty extractable- GRSP and total- GRSP), Cmic, Cefflux and extracellular enzyme activities (phosphatase, dehydrogenase, ß-glucosidase and fluorescein diacetate) were observed under Teak compared with Butea. Compared with aCO2 treatment, eCO2 slightly reduced soil available N and P under the Teak, but no changes were apparent between eCO2 and aCO2 treatments of the Butea. The greater extent of responses from soil variables observed after longer period (46 months) of CO2 exposure. The multivariate analysis confirmed that eCO2 treatment with Teak is more responsive compared with other treatments of Teak and Butea. This contrasting rhizospheric soil feedback to eCO2 between two tropical trees, suggesting fast-growing species will be more responsive to future climate. Such species will have a competitive advantage over coexisting less responsive species (e.g. Butea) under future eCO2 climate.


Assuntos
Solo , Árvores , Dióxido de Carbono , Ecossistema , Clima Tropical
6.
Clin Transplant ; 32(12): e13428, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30338873

RESUMO

Simultaneous liver-kidney allocation protocols allocate dual organs based on a sustained eGFR of 30 mL/min or less. A 2017-UNOS update includes CKD3 as dual organ candidates but only when the listing eGFR is <30 mL/min while recommending a "safety net" for prioritized kidney listing post-LT. We retrospectively reviewed adult LTs examine whether the UNOS proposal captured the LT population at highest risk for developing post-LT ESRD. Among 290 LT recipients, 67 had pre-LT CKD3, 141 had AKI, of whom 47 required dialysis (<4 weeks). During follow-up, 25 (8.62%) developed ESRD, while 70 (24.1%) died. In adjusted Cox models, CKD3 had an independent association with post-LT ESRD (adjusted HR 4.8; P = 0.001), independent of AKI. Interestingly, CKD3 with listing GFR >30 mL/min was still significantly associated with post-LT ESRD. AKI was associated with reduced post-LT survival (adjusted HR 1.9; P = 0.02), albeit only in the first-year post-LT. Severe AKI-D was associated with post-LT ESRD and mortality. The safety net would have captured only 60% of all post-LT ESRD cases in our cohort. Pre-LT CKD3 was associated with increased risk of post-LT ESRD above the recommended cutoff for listing GFR. These findings, if generalizable in larger cohorts have important implications for dual organ allocation.


Assuntos
Doença Hepática Terminal/mortalidade , Rejeição de Enxerto/mortalidade , Sobrevivência de Enxerto , Falência Renal Crônica/complicações , Transplante de Fígado/mortalidade , Complicações Pós-Operatórias/mortalidade , Insuficiência Renal/complicações , Idoso , Estudos de Casos e Controles , Doença Hepática Terminal/cirurgia , Feminino , Seguimentos , Taxa de Filtração Glomerular , Rejeição de Enxerto/etiologia , Rejeição de Enxerto/patologia , Humanos , Testes de Função Renal , Transplante de Fígado/efeitos adversos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/patologia , Prognóstico , Sistema de Registros , Estudos Retrospectivos , Fatores de Risco
7.
Int J Phytoremediation ; 19(5): 439-445, 2017 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-27739871

RESUMO

Disposal of red mud (RM) poses serious environmental problems such as wind erosion, air and water pollution. To overcome these problems, effective restoration of the disposal land through naturally growing vegetation is a sustainable and economical approach. The present study involved estimation of frequency (F), density (D), abundance (Ab), and important value index (IVI) of natural flora on abandoned RM sites in order to assess their metal toxicity tolerance capacity. Based on visual observations and highest IVI, S. Asper and S. punicea were identified as effective ecological tools for the restoration of barren RM sites. From the study, remarkable differences were observed between non-rhizospheric and rhizospheric RM of both species. These rhizospheric RM analyses confirm the ability of S. asper and S. punicea for enhancing the biological activities of abandoned RM. Translocation factor (TF) of iron was maximum (2.58) in S. asper, and bioconcentration factor (BCF) was found maximum (1.25) in S. punicea, but both TF (2.58) and BCF (1.35) were high in S. asper. Therefore, this plant could be reported as an iron hyperaccumulator plant. These results suggest that these plant species can be exploited for effective restoration of RM deposited land without any inputs or maintenance.


Assuntos
Recuperação e Remediação Ambiental , Metais Pesados/metabolismo , Sesbania/metabolismo , Poluentes do Solo/metabolismo , Sonchus/metabolismo , Biodegradação Ambiental , Índia , Resíduos Industriais/análise , Mineração , Sesbania/química , Sesbania/enzimologia , Sesbania/microbiologia , Solo/química , Sonchus/química , Sonchus/enzimologia , Sonchus/microbiologia
8.
J Environ Manage ; 192: 142-149, 2017 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-28160641

RESUMO

Glomalin related soil protein (GRSP) is a hydrophobic glycoprotein that is significant for soil organic carbon (SOC) persistence and sequestration, owing to its large contribution to SOC pool and long turnover time. However, the contribution of GRSP to dissolve OC (DOC) leach from soil is not yet comprehensively explored, though it could have implication in understanding SOC dynamics. We, therefore, aim to measure the contribution of GRSP to DOC, in a range of land uses and climatic seasons in the dry tropical ecosystem. Our results demonstrated that a significant proportion of GRSP (water soluble GRSP; WS-GRSP) leached with DOC (7.9-21.9 mg kg-1), which accounts for 0.2-0.23% of soils total GRSP (T-GRSP). Forest exhibited significantly higher WS-GRSP and DOC leaching than fallow and agriculture. WS-GRSP and DOC accumulations were higher in the dry season (summer and winter) than in rainy. The extent of seasonal variations was higher in forest than in other two land uses, indicating the role of vegetation and biological activity in soil dissolve organic matter (DOM) dynamics. The regression analysis among WS-GRSP, T-GRSP, DOC and SOC prove that the accumulations and leaching of GRSP and other soil OM (SOM) depend on similar factors. The ratio of WS-GRSP-C to DOC was higher in agriculture soil than in forest and fallow, likely a consequence of altered soil chemistry, and organic matter quantity and quality due to soil management practices. Multivariate analysis reflects a strong linkage among GRSP and SOC storage and leaching, soil nutrients (nitrogen and phosphorus) and other important soil properties (pH and bulk density), suggesting that improving GRSP and other SOM status is an urgent need for the both SOC sequestration and soil health in dry tropical agro-ecosystems.


Assuntos
Carbono/análise , Proteínas Fúngicas/análise , Glicoproteínas/análise , Agricultura , Sequestro de Carbono , Clima , Ecossistema , Florestas , Nitrogênio/análise , Fósforo/análise , Solo/química
9.
Ecotoxicol Environ Saf ; 125: 25-34, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26650422

RESUMO

Arsenic (As), a toxic metalloid adversely affects plant growth in polluted areas. In the present study, we investigated the possibility of improving phytostablization of arsenic through application of new isolated strain Brevundimonas diminuta (NBRI012) in rice plant [Oryza sativa (L.) Var. Sarju 52] at two different concentrations [10ppm (low toxic) and 50ppm (high toxic)] of As. The plant growth promoting traits of bacterial strains revealed the inherent ability of siderophores, phosphate solubilisation, indole acetic acid (IAA), 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase production which may be associated with increased biomass, chlorophyll and MDA content of rice and thereby promoting plant growth. The study also revealed the As accumulation property of NBRI012 strain which could play an important role in As removal from contaminated soil. Furthermore, NBRI012 inoculation significantly restored the hampered root epidermal and cortical cell growth of rice plant and root hair elimination. Altogether our study highlights the multifarious role of B. diminuta in mediating stress tolerance and modulating translocation of As in edible part of rice plant.


Assuntos
Arsênio/análise , Biodegradação Ambiental , Bactérias Gram-Negativas/metabolismo , Oryza/crescimento & desenvolvimento , Poluentes do Solo/análise , Aminoácidos Cíclicos , Arsênio/metabolismo , Clorofila/metabolismo , Bactérias Gram-Negativas/crescimento & desenvolvimento , Bactérias Gram-Negativas/fisiologia , Oryza/química , Oryza/efeitos dos fármacos , Raízes de Plantas/química , Raízes de Plantas/crescimento & desenvolvimento , Poluentes do Solo/metabolismo
10.
Ecotoxicology ; 25(7): 1327-37, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27300249

RESUMO

Application of endosulfan tolerant rhizospheric bacterial strain isolated from pesticide contaminated area, Ghaziabad in combination with V. zizanioides for the remediation of endosulfan is described herein. The dissipation of endosulfan from soil was considerably enhanced in the presence of bacterial strain and Vetiveria zizanioides together when compared to the dissipation in presence of either of them alone. Four strains- EAG-EC-12 (M1), EAG-EC-13(M2), EAG-EC-14(M3) and EAG-EC-15(M4) are used for this purpose. V. zizanioides was grown in garden soil spiked with 1500 µg g(-1) of endosulfan and inoculated with 100 ml of microbial culture of above motioned strains. Effect of microbial inoculation on plant growth, endosulfan uptake and endosulfan removal efficiency were analyzed. The microbial inoculation significantly enhances the growth of test plant and endosulfan dissipation from soil (p < 0.05). The addition of bacterial strain M1, M2, M3 and M4 in treated pots showed enhanced root length by 13, 33 35, 20.2 and 4.3 %, above ground plant length by 16.38, 35.56, 24.92 and 9.8 % and biomass by 33.69, 49.63, 39.24 and 17.09 % respectively when compared with endosulfan treated plants. After 135 days of exposure, a decline in endosulfan concentration by 59.12, 64.56, 62.69 and 56.39 % was obtained in the spiked soil inoculated with bacterial strains M1, M2, M3 and M4 respectively whereas, decrease in endosulfan concentration by 72.78, 85.25, 76.91 and 65.44 % in the vegetative spiked soil inoculated with same strains was observed during same exposure period. After 135 days of growth period, enhanced removal of endosulfan from experimental soil by 13.66, 20.69, 14.22 and 9.05 % was found in vegetative experiment inoculated with same strains when compared with non vegetative experiment. Result of the study showed that use of toletant plant and tolerant bacterial strains could be the better strategy for the remediation of endosulfan contaminated soil.


Assuntos
Vetiveria/fisiologia , Endossulfano/toxicidade , Rizosfera , Microbiologia do Solo , Poluentes do Solo/toxicidade , Biodegradação Ambiental
11.
J Environ Sci (China) ; 48: 112-119, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27745656

RESUMO

The arsenic tolerant bacterial strains Staphylococcus arlettae (NBRIEAG-6), Staphylococcus sp. (NBRIEAG-8) and Brevibacillus sp. (NBRIEAG-9) were tested for their roles in enhancing plant growth and induction of stress-related enzymes in rice (Oryza sativa L. cv. NDR-359) plants at two different concentrations, 30 and 15mg/kg of As(V) and As(III), respectively. An experiment was conducted to test the effect of these strains on plant growth promotion and arsenic uptake. We found 30%-40% reduction in total As uptake in bacteria-inoculated plants, with increased plant growth parameters compared to non-inoculated plants. Moreover, the bacteria-inoculated plants showed reduced activity of total glutathione (GSH) and glutathione reductase (GR) compared to their respective controls, which suggests the bacteria-mediated reduction of oxidative stress in plants. Thus, these strains were found to be beneficial in terms of the biochemical and physiological status of the plants under arsenic stress conditions. Furthermore, one-way ANOVA and principal component analysis (PCA) on enzymatic and non-enzymatic assays also revealed clear variations. The results support the distinction between control and treatments in both shoots and roots. Therefore, this study demonstrates the potential of rhizobacteria in alleviating arsenic stress in rice plants.


Assuntos
Arsênio/metabolismo , Poluentes do Solo/metabolismo , Adaptação Fisiológica , Arsênio/toxicidade , Bactérias , Biodegradação Ambiental , Brevibacillus/metabolismo , Brevibacillus/fisiologia , Glutationa/metabolismo , Oryza , Estresse Oxidativo , Rizosfera , Poluentes do Solo/toxicidade , Staphylococcus/fisiologia
12.
Int J Phytoremediation ; 17(9): 869-78, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25438026

RESUMO

A survey was undertaken, in arsenic (As) contaminated area of the Nadia district, West Bengal, India, to find native As accumulator plants. As was determined both in soil and plant parts. The results showed that the mean translocation factor of Pteris vittata L, Phragmites karka (Cav.) Trin. Ex. Steud and Christella dentata Forssk were higher than 1. It thus appeared that these plants can be efficient accumulators of As. Phytoremediation ability of C. dentata and P. karka was evaluated and compared with known As-hyperaccumulators -P. vittata and Adiantum capillus veneris L. Plants were grown in the As spiked soil (25, 50, 75 and 100 mg kg(-1)). As accumulation was found to be highest in P. vittata, 117.18 mg kg(-1) in leaf at 100 mg kg(-1) As treatment, followed by A. capillus veneris, P. karka and C. dentata being 74, 83.87 and 40.36 mg kg(-1), respectively. Lipid peroxidation increased after As exposure in all plants. However, the antioxidant enzyme activity and molecules concentration also increased which helped the plants to overcome As-induced oxidative stress. The study indicates that P. karka and C. dentata could be considered as As-accumulators and find application for As-phytoextraction in field conditions.


Assuntos
Arsênio/metabolismo , Recuperação e Remediação Ambiental , Gleiquênias/metabolismo , Poaceae/metabolismo , Poluentes do Solo/metabolismo , Antioxidantes/metabolismo , Biodegradação Ambiental , Estudos de Viabilidade , Gleiquênias/enzimologia , Índia , Poaceae/enzimologia
13.
Environ Monit Assess ; 187(8): 494, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26156315

RESUMO

The present study explores for the first time the possibility of modelling sediment concentration with artificial neural networks (ANNs) at Gangotri, the source of Bhagirathi River in the Himalaya. Discharge, rainfall and temperature have been considered as the main controlling factors of variations in sediment concentration in the dynamic glacial environment of Gangotri. Fourteen feed forward neural networks with error back propagation algorithm have been created, trained and tested for prediction of sediment concentration. Seven models (T1-T7) have been trained and tested in the non-updating mode whereas remaining seven models (T1a-T7a) have been trained in the updating mode. The non-updating mode refers to the scenario where antecedent time (previous time step) values are not used as input to the model. In case of the updating mode, antecedent time values are used as network inputs. The inputs applied in the models are either the variables mentioned above as individual factors (single input networks) or a combination of them (multi-input networks). The suitability of employing antecedent time-step values as network inputs has hence been checked by comparative analysis of model performance in the two modes. The simple feed forward network has been improvised with a series parallel non-linear autoregressive with exogenous input (NARX) architecture wherein true values of sediment concentration have been fed as input during training. In the glacial scenario of Gangotri, maximum sediment movement takes place during the melt period (May-October). Hence, daily data of discharge, rainfall, temperature and sediment concentration for five consecutive melt periods (May-October, 2000-2004) have been used for modelling. High Coefficient of determination values [0.77-0.88] have been obtained between observed and ANN-predicted values of sediment concentration. The study has brought out relationships between variables that are not reflected in normal statistical analysis. A strong rainfall: sediment concentration and temperature: sediment concentration relationship is shown by the models which are not reflected in statistical correlation. It has also been observed that usage of antecedent time-step values as network inputs does not necessarily lead to improvement in model performance.


Assuntos
Monitoramento Ambiental/métodos , Sedimentos Geológicos , Redes Neurais de Computação , Rios , Índia , Modelos Teóricos , Chuva , Temperatura
14.
Environ Monit Assess ; 187(4): 198, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25796519

RESUMO

A detailed field study was carried out to monitor (i) the arsenic contents in irrigation groundwater and paddy soil and (ii) the accumulation of arsenic in the roots and grains of different paddy varieties grown in the arsenic-contaminated middle Indo-Gangetic Plains of Northern India. Results showed the highest arsenic contamination in the irrigation groundwater (312 µg l(-1)) and in paddy soil (35 mg kg(-1)) values that were significantly exceeded the recommended threshold values of 100 µg l(-1) (EU) and 20 mg kg(-1) (FAO), respectively. The paddy soil arsenic content ranged from 3 to 35 mg kg(-1) with a mean value of 15 mg kg(-1). The soil arsenic content was found to be influenced by the soil texture, carbon, macronutrients, phosphorus, sulfur, hydrolases, and oxidoreductases properties of the paddy soils as revealed in the principal component analyses. Higher root accumulation (>10 mg kg(-1)) of arsenic was observed in 6 of the 17 paddy varieties grown in the study area. The range of arsenic content accumulated in the paddy roots was 4.1 to 16.2 mg kg(-1) dry weight (dw) and in the grains 0.179 to 0.932 mg kg(-1) dw. Out of 17 paddy varieties, eight had 0 > .55 mg kg(-1) grain arsenic content and were found unsafe for subsistence maximum daily tolerable dietary intake (MTDI) by human beings according to the regulatory standards.


Assuntos
Agricultura , Arsênio/análise , Monitoramento Ambiental/métodos , Oryza/fisiologia , Poluentes do Solo/análise , Poluentes Químicos da Água/análise , Poluição Ambiental , Contaminação de Alimentos , Água Subterrânea , Humanos , Índia , Raízes de Plantas/química , Solo
15.
Bull Environ Contam Toxicol ; 94(3): 308-13, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25666567

RESUMO

To investigate whether phytoremediation can remove arsenic from the contaminated area, a study was conducted for three consecutive years to determine the efficiency of Pteris vittata, Adiantum capillus veneris, Christella dentata and Phragmites karka, on arsenic removal from the arsenic contaminated soil. Arsenic concentrations in the soil samples were analysed after harvesting in 2009, 2010 and 2011 at an interval of 6 months. Frond arsenic concentrations were also estimated in all the successive harvests. Fronds resulted in the greatest amount of arsenic removal. Root arsenic concentrations were analysed in the last harvest. Approximately 70 % of arsenic was removed by P. vittata which was recorded as the highest among the four plant species. However, 60 % of arsenic was removed by A. capillus veneris, 55.1 % by C. dentata and 56.1 % by P. karka of arsenic was removed from the contaminated soil in 3 years.


Assuntos
Arsênio/metabolismo , Pteris/metabolismo , Poluentes do Solo/metabolismo , Arsênio/análise , Arsênio/química , Biodegradação Ambiental , Raízes de Plantas/química , Raízes de Plantas/metabolismo , Solo/química , Poluentes do Solo/análise , Poluentes do Solo/química
16.
Ecotoxicol Environ Saf ; 104: 189-93, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24681448

RESUMO

Endosulfan isomers (α+ß) and its main metabolite endosulfan sulfate were analyzed in naturally growing vegetation of pesticide contaminated area in Ghaziabad, India. Seven species of dominating plants were collected at different locations within the contaminated area. Endosulfan residues from plant parts and soil were extracted and determined by a gas chromatograph equipped with 63Ni electron capture detector (GC-ECD). Endosulfan isomers and endosulfan sulfate were present in almost all soil and plant samples. The concentration of total endosulfan in plant and soil samples analyzed ranged from 14 to 343ng g(-1) and 13 to 938ng g(-1) respectively. Out of seven plant species studied, Vetiveria zizanioides (Khus Khus) and Sphenoclea zeylamica (Chikenspike) showed the highest and lowest accumulation respectively, with a significant difference at p<0.01 level. Vetiveria zizanioides and Digitaria longiflora (Crab grass) could accumulate considerable levels of endosulfan isomers (α+ß) (343 and 163ng g(-1) respectively) and endosulfan sulfate (21 and 2ng g(-1), respectively). The outcomes of the study reflect the value of test species in monitoring purposes and their potential for remediation of contaminated sites.


Assuntos
Endossulfano/análogos & derivados , Monitoramento Ambiental , Plantas/metabolismo , Poluentes do Solo/metabolismo , Cromatografia Gasosa , Vetiveria/química , Vetiveria/metabolismo , Endossulfano/análise , Endossulfano/metabolismo , Índia , Isomerismo , Plantas/química , Solo/química , Poluentes do Solo/análise
17.
Ecotoxicol Environ Saf ; 109: 22-6, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25133347

RESUMO

Remediation and management of organochlorine pesticide (OCPs) contaminated soil is becoming a global priority as they are listed in the Stockholm list of persistent organic pollutants (POPs) for global elimination. Lindane is a OCPs candidate recently included in the Stockholm list. However, India has an exemption to produce lindane for malaria control. Because of its widespread use during the last few decades, lindane contaminated soils are found in almost all parts of India. Since phytoremediation is widely acknowledged as an innovative strategy for the clean-up of contaminated soils; the present study was aimed to evaluate the phytoextraction and dissipation of lindane by a leafy vegetable Spinacia oleracea L (Spinach). The test plant was grown in different concentrations of lindane (5, 10, 15 and 20 mg kg(-1)) and harvested at 10, 30 and 45 days. At 45 days, the concentrations of lindane in root and leaf of Spinach growing in four different concentrations were reached up to 3.5, 5.4, 7.6 and 12.3 mg kg(-1) and 1.8, 2.2, 3 and 4.9 mg kg(-1), respectively. There was a significant difference (p<0.01) in the dissipation of lindane in vegetated and non-vegetated soil. Moreover, the residual lindane in four experiments was reduced to 81, 76, 69 and 61 percent, respectively. The experimental results indicate that Spinach can be used for the phytoremediation of lindane. However, more studies are required to prevent the toxicity of harvested parts.


Assuntos
Hexaclorocicloexano/metabolismo , Praguicidas/metabolismo , Poluentes do Solo/metabolismo , Spinacia oleracea/metabolismo , Biodegradação Ambiental , Clorofila/química , Clorofila/metabolismo , Cromatografia Gasosa , Hexaclorocicloexano/análise , Praguicidas/análise , Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Poluentes do Solo/análise , Fatores de Tempo
18.
Biomacromolecules ; 14(5): 1287-98, 2013 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-23534615

RESUMO

Biomaterials that can stimulate stem cell differentiation without growth factor supplementation provide potent and cost-effective scaffolds for regenerative medicine. We hypothesize that a scaffold prepared from cellulose and silk blends can direct stem cell chondrogenic fate. We systematically prepared cellulose blends with silk at different compositions using an environmentally benign processing method based on ionic liquids as a common solvent. We tested the effect of blend compositions on the physical properties of the materials as well as on their ability to support mesenchymal stem cell (MSC) growth and chondrogenic differentiation. The stiffness and tensile strength of cellulose was significantly reduced by blending with silk. The characterized materials were tested using MSCs derived from four different patients. Growing MSCs on a specific blend combination of cellulose and silk in a 75:25 ratio significantly upregulated the chondrogenic marker genes SOX9, aggrecan, and type II collagen in the absence of specific growth factors. This chondrogenic effect was neither found with neat cellulose nor the cellulose/silk 50:50 blend composition. No adipogenic or osteogenic differentiation was detected on the blends, suggesting that the cellulose/silk 75:25 blend induced specific stem cell differentiation into the chondrogenic lineage without addition of the soluble growth factor TGF-ß. The cellulose/silk blend we identified can be used both for in vitro tissue engineering and as an implantable device for stimulating endogenous stem cells to initiate cartilage repair.


Assuntos
Materiais Biocompatíveis/farmacologia , Celulose/química , Condrócitos/efeitos dos fármacos , Condrogênese/efeitos dos fármacos , Células-Tronco Mesenquimais/efeitos dos fármacos , Seda/química , Engenharia Tecidual/métodos , Agrecanas/genética , Agrecanas/metabolismo , Materiais Biocompatíveis/química , Diferenciação Celular , Condrócitos/citologia , Condrócitos/metabolismo , Colágeno Tipo II/genética , Colágeno Tipo II/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Líquidos Iônicos , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Fatores de Transcrição SOX9/genética , Fatores de Transcrição SOX9/metabolismo , Resistência à Tração , Alicerces Teciduais
19.
Nat Genet ; 33(3): 339-41, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12577058

RESUMO

Random monoallelic expression and asynchronous replication define an unusual class of autosomal mammalian genes. We show that every cell has randomly chosen either the maternal or paternal copy of each given autosome pair, such that alleles of these genes scattered across the chosen chromosome replicate earlier than the alleles on the homologous chromosome. Thus, chromosome-pair non-equivalence, rather than being limited to X-chromosome inactivation, is a fundamental property of mouse chromosomes.


Assuntos
Replicação do DNA/genética , Alelos , Animais , Cromossomos/genética , Mecanismo Genético de Compensação de Dose , Feminino , Expressão Gênica , Impressão Genômica , Hibridização in Situ Fluorescente , Masculino , Camundongos , Receptores Odorantes/genética , Fatores de Tempo
20.
Biosensors (Basel) ; 13(2)2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36831931

RESUMO

Nanobiosensors are devices that utilize a very small probe and any form of electrical, optical, or magnetic technology to detect and analyze a biochemical or biological process. With an increasing population today, nanobiosensors have become the broadly used electroanalytical tools for the timely detection of many infectious (dengue, hepatitis, tuberculosis, leukemia, etc.) and other fatal diseases, such as prostate cancer, breast cancer, etc., at their early stage. Compared to classical or traditional analytical methods, nanobiosensors have significant benefits, including low detection limit, high selectivity and sensitivity, shorter analysis duration, easier portability, biocompatibility, and ease of miniaturization for on-site monitoring. Very similar to biosensors, nanobiosensors can also be classified in numerous ways, either depending on biological molecules, such as enzymes, antibodies, and aptamer, or by working principles, such as optical and electrochemical. Various nanobiosensors, such as cyclic voltametric, amperometric, impedimetric, etc., have been discussed for the timely monitoring of the infectious and fatal diseases at their early stage. Nanobiosensors performance and efficiency can be enhanced by using a variety of engineered nanostructures, which include nanotubes, nanoparticles, nanopores, self-adhesive monolayers, nanowires, and nanocomposites. Here, this mini review recaps the application of two-dimensional (2D) materials, especially graphitic carbon nitride (g-C3N4), graphene oxide, black phosphorous, and MXenes, for the construction of the nanobiosensors and their application for the diagnosis of various infectious diseases at very early stage.


Assuntos
Técnicas Biossensoriais , Doenças Transmissíveis , Nanocompostos , Nanopartículas , Nanoestruturas , Nanotubos , Humanos , Nanoestruturas/química , Nanotecnologia/métodos , Técnicas Biossensoriais/métodos
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