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1.
Sci Rep ; 14(1): 11743, 2024 05 23.
Artículo en Inglés | MEDLINE | ID: mdl-38778072

RESUMEN

Agricultural field experiments are costly and time-consuming, and often struggling to capture spatial and temporal variability. Mechanistic crop growth models offer a solution to understand intricate crop-soil-weather system, aiding farm-level management decisions throughout the growing season. The objective of this study was to calibrate and the Crop Environment Resource Synthesis CERES-Maize (DSSAT v 4.8) model to simulate crop growth, yield, and nitrogen dynamics in a long-term conservation agriculture (CA) based maize system. The model was also used to investigate the relationship between, temperature, nitrate and ammoniacal concentration in soil, and nitrogen uptake by the crop. Additionally, the study explored the impact of contrasting tillage practices and fertilizer nitrogen management options on maize yields. Using field data from 2019 and 2020, the DSSAT-CERES-Maize model was calibrated for plant growth stages, leaf area index-LAI, biomass, and yield. Data from 2021 were used to evaluate the model's performance. The treatments consisted of four nitrogen management options, viz., N0 (without nitrogen), N150 (150 kg N/ha through urea), GS (Green seeker-based urea application) and USG (urea super granules @150kg N/ha) in two contrasting tillage systems, i.e., CA-based zero tillage-ZT and conventional tillage-CT. The model accurately simulated maize cultivar's anthesis and physiological maturity, with observed value falling within 5% of the model's predictions range. LAI predictions by the model aligned well with measured values (RMSE 0.57 and nRMSE 10.33%), with a 14.6% prediction error at 60 days. The simulated grain yields generally matched with measured values (with prediction error ranging from 0 to 3%), except for plots without nitrogen application, where the model overestimated yields by 9-16%. The study also demonstrated the model's ability to accurately capture soil nitrate-N levels (RMSE 12.63 kg/ha and nRMSE 12.84%). The study concludes that the DSSAT-CERES-Maize model accurately assessed the impacts of tillage and nitrogen management practices on maize crop's growth, yield, and soil nitrogen dynamics. By providing reliable simulations during the growing season, this modelling approach can facilitate better planning and more efficient resource management. Future research should focus on expanding the model's capabilities and improving its predictions further.


Asunto(s)
Agricultura , Fertilizantes , Nitrógeno , Suelo , Zea mays , Zea mays/crecimiento & desarrollo , Zea mays/metabolismo , Nitrógeno/metabolismo , Agricultura/métodos , Suelo/química , Triticum/crecimiento & desarrollo , Triticum/metabolismo , Productos Agrícolas/crecimiento & desarrollo , Biomasa
2.
Mymensingh Med J ; 33(1): 183-191, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38163791

RESUMEN

This cross-sectional study was conducted to explore quinolone resistant Enterobacteriaceae followed by searching the prevalence of three groups of quinolone resistance genes (QnrA, QnrB and QnrS) from January 2015 to December 2015 at Dhaka Medical College hospital, Bangladesh. Then genes for ESBL and AmpC ß-lactamase were detected among Qnr positive strains for better understanding the role of these genes for multiple drug resistance. Total 340 urines, sputum, wound swab and blood samples were collected from DMCH. Total 270(79.41%) Enterobacteriaceae were isolated from 340 samples. Out of 270 Enterobacteriaceae, 225(83.33%) were quinolone (ciprofloxacin) resistant strains. Qnr genes were detected in 141(62.67%) of the 225 quinolone resistant Enterobacteriaceae. Total 187 Qnr genes [84(59.57%) QnrS, 70(49.64%) QnrB and 33(23.40%) QnrA] were detected from 141 quinolone resistant strains. Total 48(34.04%) ESBL producers were detected by DDS test and 47(33.33%) ESBL producers were positive by PCR among 141 Qnr positive strains. QnrA was co-existed with CTX-M-15. QnrB was co-existed with TEM, CTXM-15 and OXA-1. QnrS genes were also associated with TEM, CTX-M-15 and OXA-1. Among 52 cefoxitin resistant Qnr positive strains, 22(42.31%) AmpC ß-lactamase producers were detected by Modified three-dimensional test (MTDT) and 45(86.54%) AmpC ß-lactamase producers were detected by PCR. QnrA had been identified with DHA, ACC, EBC and CIT while QnrB had been identified with DHA, ACC, EBC and CIT. QnrS had also been co-existed with DHA, ACC, EBC and CIT. The results of this study provided insights into the high proportion of Qnr genes among isolated Enterobacteriaceae. Simultaneous presence of Qnr genes and genes for extended-spectrum ß-lactamase or AmpC ß-lactamase were observed in multidrug resistant Enterobacteriaceae.


Asunto(s)
Infecciones por Enterobacteriaceae , Quinolonas , Humanos , Enterobacteriaceae/genética , Quinolonas/farmacología , Bangladesh , Estudios Transversales , Antibacterianos/farmacología , Infecciones por Enterobacteriaceae/tratamiento farmacológico , Infecciones por Enterobacteriaceae/genética , Infecciones por Enterobacteriaceae/epidemiología , Farmacorresistencia Bacteriana/genética , beta-Lactamasas/genética , Pruebas de Sensibilidad Microbiana
3.
MethodsX ; 9: 101916, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36438857

RESUMEN

Canopy covers can be measured using destructive (visual) and non-destructive methods (spectral indices, photogrammetry, visual assessment, and quantum sensor). The precision of crop cover estimation, however, is dependent on the selection of appropriate methods. Studies were conducted at the Indian Grassland and Fodder Research Institute, Jhansi to compare the forage crops canopy cover estimated using photogrammetry software (Canopeo and SamplePoint) and visual assessments. Assessments were performed in three summer crops (corn, cowpea, and sorghum), two winter crops (Egyptian clover, and oats), and bare ground condition. For each plot, three nadir images (directly above the canopy) were captured using digital cameras from a height of 1.5 m above the soil surface between 10 AM to 2 PM on bright sunny days. The results indicated that the relationships between visual assessment and Canopeo (regression coefficient, (R2 = 0.96), visual assessment and SamplePoint (0.96), and Canopeo and SamplePoint (0.98) were linear when data were pooled across all the crops. SamplePoint and Canopeo is further, appropriate for cowpea (Pearson coefficient (R = 0.99 and 0.94), oats (0.92 and 0.97), and sorghum (0.46 and 0.51), respectively. SamplePoint and Canopeo are not suitable for berseem (-0.15) and corn (-0.61), respectively, due to dead residues after the first harvest in berseem and taller corn might have influenced the image quality. Therefore, the stage of the crop, the height of the crop, and dead residues around the plants can greatly influence the estimation of crop cover. In conclusion, the results indicated that this photogrammetry software can be used for non-destructive crop canopy measurement with the above-mentioned precautions in the forage crops tested. •Forage canopy cover is estimated generally by visual scoring, and the outcome varies widely from person to person.•Photogrammetry methods (Canopeo and SamplePoint) were positiviely correlated with visual scoring for cowpea, oats, and sorghum.•However, Canopeo and SamplePoint may not suitable for taller crops like corn and ratoon crops like berseem.

4.
Front Plant Sci ; 13: 975569, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36212325

RESUMEN

Photosynthesis, crop health and dry matter partitioning are among the most important factors influencing crop productivity and quality. Identifying variation in these parameters may help discover the plausible causes for crop productivity differences under various management practices and cropping systems. Thus, a 2-year (2019-2020) study was undertaken to investigate how far the integrated crop management (ICM) modules and cropping systems affect maize physiology, photosynthetic characteristics, crop vigour and productivity in a holistic manner. The treatments included nine main-plot ICM treatments [ICM1 to ICM4 - conventional tillage (CT)-based; ICM5 to ICM8 - conservation agriculture (CA)-based; ICM9 - organic agriculture (OA)-based] and two cropping systems, viz., maize-wheat and maize + blackgram-wheat in subplots. The CA-based ICM module, ICM7 resulted in significant (p < 0.05) improvements in the physiological parameters, viz., photosynthetic rate (42.56 µ mol CO2 m-2 sec-1), transpiration rate (9.88 m mol H2O m-2 sec-1) and net assimilation rate (NAR) (2.81 mg cm-2 day-1), crop vigour [NDVI (0.78), chlorophyll content (53.0)], dry matter partitioning toward grain and finally increased maize crop productivity (6.66 t ha-1) by 13.4-14.2 and 27.3-28.0% over CT- and OA-based modules. For maize equivalent grain yield (MEGY), the ICM modules followed the trend as ICM7 > ICM8 > ICM5 > ICM6 > ICM3 > ICM4 > ICM1 > ICM2 > ICM9. Multivariate and PCA analyses also revealed a positive correlation between physiological parameters, barring NAR and both grain and stover yields. Our study proposes an explanation for improved productivity of blackgram-intercropped maize under CA-based ICM management through significant improvements in physiological and photosynthetic characteristics and crop vigour. Overall, the CA-based ICM module ICM7 coupled with the maize + blackgram intercropping system could be suggested for wider adoption to enhance the maize production in semiarid regions of India and similar agroecologies across the globe.

5.
Pestic Biochem Physiol ; 182: 105026, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35249642

RESUMEN

In rice farming, the blast disease caused by Magnaporthe oryzae (T.T. Hebert) M.E. Barr. is one of the primary production constraints worldwide. The current blast management options such as blast-resistant varieties and spraying fungicides are neither durable nor commercially and environmentally compatible. In the present study, we investigated the antifungal and defense elicitor activity of potassium phosphite (Phi) against M. oryzae on elite rice cultivar BPT5204 (popularly known as Samba Mahsuri in India) and its transgenic rice variant (ptxD-OE) over-expressing a phosphite dehydrogenase enzyme. The Phi was evaluated both preventively and curatively on rice genotypes where the preventive spray of Phi outperformed the Phi curative application with significant reductions in both rice blast severity (35.67-60.49%) and incidence (22.27-53.25%). Moreover, the application of Phi increased the levels of photosynthetic pigments (Chlorophyll and Carotenoids) coupled with increased activity of defense enzymes (PAL, SOD, and APx). Besides, Phi application also induced the expression of defense-associated genes (OsCEBiP and OsPDF2.2) in the rice leaf. Furthermore, the Phi application reduced the reactive Malondialdehyde (lipid peroxidation) to minimize the cellular damage incited by Magnaporthe in rice. Overall, the present study showed the potential of Phi for blast suppression on rice as an alternative to the current excessive use of toxic fungicides.


Asunto(s)
Magnaporthe , Oryza , Antifúngicos , Oryza/genética , Oryza/microbiología , Fosfitos , Enfermedades de las Plantas/microbiología , Compuestos de Potasio
6.
Plant Sci ; 311: 111009, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34482912

RESUMEN

Weeds, pests, and pathogens are among the pre-harvest constraints in rice farming across rice-growing countries. For weed management, manual weeding and herbicides are widely practiced. Among the herbicides, glyphosate [N-(phosphonomethyl) glycine] is a broad-spectrum systemic chemical extensively used in agriculture. Being a competitive structural analog to phosphoenolpyruvate, it selectively inhibits the conserved 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) enzyme required for the biosynthesis of aromatic amino acids and essential metabolites in eukaryotes and prokaryotes. In the present study, we investigated the antifungal and defense elicitor activity of glyphosate against Magnaporthe oryzae on transgenic-rice overexpressing a glyphosate-resistance OsEPSPS gene (T173I + P177S; TIPS OsmEPSPS) for blast disease management. The glyphosate foliar spray on OsmEPSPS transgenic rice lines showed both prophylactic and curative suppression of blast disease comparable to a blasticide, tricyclazole. The glyphosate displayed direct antifungal activity on Magnaporthe oryzae as well as enhanced the levels of antioxidant enzymes and photosynthetic pigments in rice. However, the genes associated with phytohormones-mediated defense (OsPAD4, OsNPR1.3, and OsFMO) and innate immunity pathway (OsCEBiP and OsCERK1) were found repressed upon glyphosate spray. Altogether, the current study is the first report highlighting the overexpression of a crop-specific TIPS mutation in conjugation with glyphosate application showing potential for blast disease management in rice cultivation.


Asunto(s)
Antifúngicos/farmacología , Ascomicetos/patogenicidad , Resistencia a los Herbicidas/genética , Herbicidas/farmacocinética , Oryza/genética , Oryza/microbiología , Oryza/fisiología , Enfermedades de las Plantas/prevención & control , Ascomicetos/efectos de los fármacos , Productos Agrícolas/genética , Productos Agrícolas/microbiología , Productos Agrícolas/fisiología , Regulación de la Expresión Génica de las Plantas , Genes de Plantas , Variación Genética , Genotipo , Enfermedades de las Plantas/genética , Plantas Modificadas Genéticamente/genética
7.
Hum Exp Toxicol ; 37(11): 1199-1206, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29441828

RESUMEN

The susceptibility of the kidneys to fluoride toxicity can largely be attributed to its anatomy and function. As the filtrate moves along the complex tubular structure of each nephron, it is concentrated in the proximal and distal tubules and collecting duct. It has been frequently observed that the children suffering from renal impairments also have some symptoms of dental and skeletal fluorosis. The findings suggest that fluoride somehow interferes with renal anatomy and physiology, which may lead to renal pathogenesis. The aim of this study was to evaluate the fluoride-associated nephrotoxicity. A total of 156 patients with childhood nephrotic syndrome were screened and it was observed that 32 of them had significantly high levels ( p ≤ 0.05) of fluoride in urine (4.01 ± 1.83 ppm) and serum (0.1 ± 0.013 ppm). On the basis of urinary fluoride concentration, patients were divided into two groups, namely group 1 (G-1) ( n = 32) containing normal urine fluoride (0.61 ± 0.17 ppm) and group 2 (G-2) ( n = 32) having high urine fluoride concentration (4.01 ± 1.83 ppm). Age-matched healthy subjects ( n = 33) having normal levels of urinary fluoride (0.56 ± 0.15 ppm) were included in the study as control (group 0 (G-0)). Kidney biopsies were taken from G-1 and G-2 only, who were subjected to ultrastructural (transmission electron microscopy) and apoptotic (terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling) analysis. Various subcellular ultrastructural changes including nuclear disintegration, chromosome condensation, cytoplasmic ground substance lysis, and endoplasmic reticulum blebbing were observed. Increased levels of apoptosis were observed in high fluoride group (G-2) compared to normal fluoride group (G-1). Various degrees of fluoride-associated damages to the architecture of tubular epithelia, such as cell swelling and lysis, cytoplasmic vacuolation, nuclear condensation, apoptosis, and necrosis, were observed.


Asunto(s)
Apoptosis/efectos de los fármacos , Fluoruros/efectos adversos , Túbulos Renales/efectos de los fármacos , Síndrome Nefrótico/inducido químicamente , Contaminantes Químicos del Agua/efectos adversos , Biopsia , Estudios de Casos y Controles , Niño , Preescolar , Femenino , Fluoruros/sangre , Fluoruros/orina , Humanos , Etiquetado Corte-Fin in Situ , Túbulos Renales/ultraestructura , Masculino , Microscopía Electrónica de Transmisión , Síndrome Nefrótico/sangre , Síndrome Nefrótico/patología , Síndrome Nefrótico/orina , Proyectos Piloto , Contaminantes Químicos del Agua/sangre , Contaminantes Químicos del Agua/orina
8.
Environ Monit Assess ; 189(4): 198, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28361488

RESUMEN

Increasing nitrogen (N) immobilization and weed interference in the early phase of implementation of conservation agriculture (CA) affects crop yields. Yet, higher fertilizer and herbicide use to improve productivity influences greenhouse gase emissions and herbicide residues. These tradeoffs precipitated a need for adaptive N and integrated weed management in CA-based maize (Zea mays L.)-wheat [Triticum aestivum (L.) emend Fiori & Paol] cropping system in the Indo-Gangetic Plains (IGP) to optimize N availability and reduce weed proliferation. Adaptive N fertilization was based on soil test value and normalized difference vegetation index measurement (NDVM) by GreenSeeker™ technology, while integrated weed management included brown manuring (Sesbania aculeata L. co-culture, killed at 25 days after sowing), herbicide mixture, and weedy check (control, i.e., without weed management). Results indicated that the 'best-adaptive N rate' (i.e., 50% basal + 25% broadcast at 25 days after sowing + supplementary N guided by NDVM) increased maize and wheat grain yields by 20 and 14% (averaged for 2 years), respectively, compared with whole recommended N applied at sowing. Weed management by brown manuring (during maize) and herbicide mixture (during wheat) resulted in 10 and 21% higher grain yields (averaged for 2 years), respectively, over the weedy check. The NDVM in-season N fertilization and brown manuring affected N2O and CO2 emissions, but resulted in improved carbon storage efficiency, while herbicide residuals in soil were significantly lower in the maize season than in wheat cropping. This study concludes that adaptive N and integrated weed management enhance synergy between agronomic productivity, fertilizer and herbicide efficiency, and greenhouse gas mitigation.


Asunto(s)
Agricultura/métodos , Monitoreo del Ambiente/métodos , Nitrógeno/análisis , Malezas , Carbono/química , Grano Comestible/química , Fertilizantes/análisis , Herbicidas/análisis , Estiércol/análisis , Suelo/química , Triticum , Zea mays
9.
J Environ Sci Health B ; 52(6): 402-409, 2017 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-28272993

RESUMEN

Controlled release formulations of imazethapyr herbicide have been developed employing guar gum-g-cl-polyacrylate/bentonite clay hydrogel composite (GG-HG) and guar gum-g-cl-PNIPAm nano hydrogel (GG-NHG) as carriers, to assess the suitability of biopolymeric hydrogels as controlled herbicide release devices. The kinetics of imazethapyr release from the developed formulations was studied in water and it revealed that the developed formulations of imazethapyr behaved as slow release formulations as compared to commercial formulation. The calculated diffusion exponent (n) values showed that Fickian diffusion was the predominant mechanism of imazethapyr release from the developed formulations. Time for release of half of the loaded imazethapyr (t1/2) ranged between 0.06 and 4.8 days in case of GG-NHG and 4.4 and 12.6 days for the GG-HG formulations. Weed control index (WCI) of GG-HG and GG-NHG formulations was similar to that of the commercial formulation and the herbicidal effect was observed for relatively longer period. Guar gum-based biopolymeric hydrogels in both macro and nano particle size range can serve as potential carriers in developing slow release herbicide formulations.


Asunto(s)
Herbicidas/farmacocinética , Hidrogeles/química , Ácidos Nicotínicos/farmacocinética , Resinas Acrílicas , Silicatos de Aluminio/química , Bentonita/química , Arcilla , Difusión , Galactanos/química , Herbicidas/química , India , Cinética , Mananos/química , Nanocompuestos/química , Ácidos Nicotínicos/química , Tamaño de la Partícula , Gomas de Plantas/química
10.
Health Care Manag Sci ; 19(1): 1-19, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24710651

RESUMEN

Uncertainty of pandemic influenza viruses continue to cause major preparedness challenges for public health policymakers. Decisions to mitigate influenza outbreaks often involve tradeoff between the social costs of interventions (e.g., school closure) and the cost of uncontrolled spread of the virus. To achieve a balance, policymakers must assess the impact of mitigation strategies once an outbreak begins and the virus characteristics are known. Agent-based (AB) simulation is a useful tool for building highly granular disease spread models incorporating the epidemiological features of the virus as well as the demographic and social behavioral attributes of tens of millions of affected people. Such disease spread models provide excellent basis on which various mitigation strategies can be tested, before they are adopted and implemented by the policymakers. However, to serve as a testbed for the mitigation strategies, the AB simulation models must be operational. A critical requirement for operational AB models is that they are amenable for quick and simple calibration. The calibration process works as follows: the AB model accepts information available from the field and uses those to update its parameters such that some of its outputs in turn replicate the field data. In this paper, we present our epidemiological model based calibration methodology that has a low computational complexity and is easy to interpret. Our model accepts a field estimate of the basic reproduction number, and then uses it to update (calibrate) the infection probabilities in a way that its effect combined with the effects of the given virus epidemiology, demographics, and social behavior results in an infection pattern yielding a similar value of the basic reproduction number. We evaluate the accuracy of the calibration methodology by applying it for an AB simulation model mimicking a regional outbreak in the US. The calibrated model is shown to yield infection patterns closely replicating the input estimates of the basic reproduction number. The calibration method is also tested to replicate an initial infection incidence trend for a H1N1 outbreak like that of 2009.


Asunto(s)
Brotes de Enfermedades/estadística & datos numéricos , Métodos Epidemiológicos , Gripe Humana/epidemiología , Gripe Humana/transmisión , Modelos Teóricos , Algoritmos , Simulación por Computador , Conductas Relacionadas con la Salud , Humanos , Incidencia , Gripe Humana/prevención & control , Factores Socioeconómicos
11.
Environ Monit Assess ; 187(10): 610, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26341501

RESUMEN

Possible bioaccumulation of pesticides in crop produce may cause ill effects on animals and humans. Tribenuron-methyl is a new post-emergence herbicide and is highly efficient to control the broad-leaf weeds in cereals, pasture, and plantation crops. There are scarce studies on its bioefficacy, sensitivity to weeds, tolerance to wheat, and persistence in crop produce, which are important information required before recommending an herbicide for use by the farmers. Weed control efficiency of an herbicide is dose-sensitive and site/soil-specific. Tribenuron-methyl (75% DF) was applied at 22.5 and 45.0 g a.i./ha along with the surfactant 300.12 mL/ha as a tank mixes after 30 days of sowing in wheat as post-emergence herbicide. The samples of wheat foliage, soil, and grains at harvest were processed and analyzed for residues by high-performance liquid chromatography using a UV detector at 240 nm. The study revealed that there was a significant reduction in weed population and dry matter accumulation due to tribenuron-methyl application at a higher dose (45.0 g/ha) compared to a lower dose (of 22.5 g/ha). The weed density was found to be from 16.1 to 44.3 no/m(2) for application rate of 22.5 g/ha while at the 45.0 g/ha application, the weed density was 5.3-5.9 as compared to untreated control, where 184.3-120.5 no/m(2) was observed. The yield varied from 4.30 to 4.80 t/ha as compared to 2.25-3.55 t/ha in unweeded control with the LSD value being 21.5-16.3 to 0.27-0.19. Residues were below detectable level (BDL, <0.005 mg/kg) of tribenuron-methyl since they were detected in wheat grains at 22.5 g a.i./ha rates. However, 0.012 µg/g residues were detected in wheat foliage at an application rate of 45.0 g a.i./ha. It can be concluded that it is safe to use tribenuron-methyl at 22.5 g a.i./ha on wheat crop as post-emergence herbicide.


Asunto(s)
Arilsulfonatos/análisis , Ecosistema , Monitoreo del Ambiente/métodos , Herbicidas/análisis , Contaminantes del Suelo/análisis , Triticum/química , Agricultura/métodos , Cromatografía Líquida de Alta Presión , Humanos , India
12.
Curr Microbiol ; 71(5): 585-93, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26271295

RESUMEN

Gram-negative plant pathogenic bacteria regulate specific gene expression in a population density-dependent manner by sensing level of Acyl-Homoserine Lactone (HSL) molecules which they produce and liberate to the environment, called Quorum Sensing (QS). The production of virulence factors (extracellular enzyme viz. cellulase, pectinase, etc.) in Pectobacterium carotovorum subsp. carotovorum (Pcc) is under strong regulation of QS. The QS signal molecule, N-(3-oxohexanoyl)-L-Homoserine Lactone (OHHL) was found as the central regulatory system for the virulence factor production in Pcc and is also under strict regulation of external environmental temperature. Under seven different incubation temperatures (24, 26, 28, 30, 33, 35, and 37 °C) in laboratory condition, highest amount of OHHL (804 violacein unit) and highest (79 %) Disease Severity Index (DSI) were measured at 33 °C. The OHHL production kinetics showed accumulation of highest concentration of OHHL at late log phase of the growth but diminution in the concentration occurred during stationary phase onwards to death phase. At higher temperature (35 and 37 °C) exposure, OHHL was not at detectable range. The effect of temperature on virulence factor production is the concomitant effect of HSL production and degradation which justifies less disease severity index in cross-inoculated tomato fruits incubated at 35 and 37 °C. The nondetection of the OHHL in the elevated temperature may because of degradation as these signal molecules are quite sensitive and prone to get degraded under different physical factors. This result provides the rationale behind the highest disease severity up to certain elevated temperature and leaves opportunities for investigation on mutation, co-evolution of superior plant pathogen with more stable HSL signals-mediated pathogenesis under global warming context.


Asunto(s)
Interacciones Huésped-Patógeno , Interacciones Microbianas , Pectobacterium carotovorum/fisiología , Plantas/microbiología , Temperatura , 4-Butirolactona/análogos & derivados , 4-Butirolactona/biosíntesis , Fenotipo , Enfermedades de las Plantas/microbiología , Percepción de Quorum , Virulencia/genética
13.
Biomed Res Int ; 2014: 237898, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25276772

RESUMEN

With the advent of neuroimaging techniques, it becomes feasible to explore the structure-function relationships in the brain. When the brain is not involved in any cognitive task or stimulated by any external output, it preserves important activities which follow well-defined spatial distribution patterns. Understanding the self-organization of the brain from its anatomical structure, it has been recently suggested to model the observed functional pattern from the structure of white matter fiber bundles. Different models which study synchronization (e.g., the Kuramoto model) or global dynamics (e.g., the Ising model) have shown success in capturing fundamental properties of the brain. In particular, these models can explain the competition between modularity and specialization and the need for integration in the brain. Graphing the functional and structural brain organization supports the model and can also highlight the strategy used to process and organize large amount of information traveling between the different modules. How the flow of information can be prevented or partially destroyed in pathological states, like in severe brain injured patients with disorders of consciousness or by pharmacological induction like in anaesthesia, will also help us to better understand how global or integrated behavior can emerge from local and modular interactions.


Asunto(s)
Encéfalo/anatomía & histología , Encéfalo/fisiología , Modelos Neurológicos , Mapeo Encefálico , Simulación por Computador , Humanos , Red Nerviosa/fisiología
14.
Virchows Arch ; 465(5): 521-30, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25240724

RESUMEN

Abnormalities of transmembrane and cytoplasmic proteins of tight junctions (TJ) have been implicated in pathogenesis of both celiac (CeD) and Crohn's diseases (CD). Since disease pathogenesis in CeD and CD are different, we planned to study if there is any differential expression pattern of TJ marker proteins and ultrastructural changes, respectively, in duodenal villi vs crypts. Endoscopic duodenal biopsies from treatment naïve patients with CeD (n = 24), active CD (n = 28), and functional dyspepsia (as controls, n = 15), both at baseline and 6 months after treatment, were subjected to light microscopic analysis (modified Marsh grading); immune-histochemical staining and Western blot analysis to see the expression of key TJ proteins [trans-membrane proteins (claudin-2, claudin-3, claudin-4, occludin, and JAM) and cytoplasmic protein (ZO-1)]. Transmission electron microscopy and image analysis of the TJs were also performed. There was significant overexpression of claudin-2 (pore-forming) and occludin (protein maintaining cell polarity) with under-expression of claudin-3 and claudin-4 (pore-sealing proteins) in treatment naïve CeD and active CD with simultaneous alteration in ultrastructure of TJs such as loss of penta-laminar structure and TJ dilatation. Normalization of some of these TJ proteins was noted 6 months after treatment. These changes were not disease specific and were not different in duodenal villi and crypts. Overexpression of pore-forming and under-expression of pore-sealing TJ proteins lead to dilatation of TJ. These changes are neither disease specific nor site specific and the end result of mucosal inflammation.


Asunto(s)
Enfermedad Celíaca/patología , Enfermedad de Crohn/patología , Duodeno/ultraestructura , Uniones Estrechas/ultraestructura , Adolescente , Adulto , Biopsia , Enfermedad Celíaca/fisiopatología , Claudina-2/biosíntesis , Claudinas/biosíntesis , Enfermedad de Crohn/fisiopatología , Duodeno/patología , Células Epiteliales/patología , Femenino , Expresión Génica , Humanos , Mucosa Intestinal/metabolismo , Moléculas de Adhesión de Unión/biosíntesis , Masculino , Microscopía Electrónica de Transmisión , Ocludina/biosíntesis , Uniones Estrechas/metabolismo , Proteína de la Zonula Occludens-1/biosíntesis
15.
Oncogenesis ; 2: e69, 2013 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-24018644

RESUMEN

Centrosomal kinase Nek2 is overexpressed in different cancers, yet how it contributes toward tumorigenesis remains poorly understood. dNek2 overexpression in a Drosophila melanogaster model led to upregulation of Drosophila Wnt ortholog wingless (Wg), and alteration of cell migration markers-Rho1, Rac1 and E-cadherin (Ecad)-resulting in changes in cell shape and tissue morphogenesis. dNek2 overexpression cooperated with receptor tyrosine kinase and mitogen-activated protein kinase signaling to upregulate activated Akt, Diap1, Mmp1 and Wg protein to promote local invasion, distant seeding and metastasis. In tumor cell injection assays, dNek2 cooperated with Ras and Src signaling to promote aggressive colonization of tumors into different adult fly tissues. Inhibition of the PI3K pathway suppressed the cooperation of dNek2 with other growth pathways. Consistent with our fly studies, overexpression of human Nek2 in A549 lung adenocarcinoma and HEK293T cells led to activation of the Akt pathway and increase in ß-catenin protein levels. Our computational approach identified a class of Nek2-inhibitory compounds and a novel drug-like pharmacophore that reversed the Nek2 overexpression phenotypes in flies and human cells. Our finding posits a novel role for Nek2 in promoting metastasis in addition to its currently defined role in promoting chromosomal instability. It provides a rationale for the selective advantage of centrosome amplification in cancer.

16.
Ecotoxicol Environ Saf ; 97: 236-41, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23972318

RESUMEN

Field evaluation of two fly ashes (40t/ha) on persistence, mobility and bioactivity of metribuzin and metsulfuron-methyl was studied in soybean and wheat crops, respectively. Metribuzin was applied as pre-emergence at 0.5kg/ha, while metsulfuron-methyl was applied post-emergence at 8g/ha. Results suggested that metribuzin in surface (0-15cm) soil of fly ash unamended plots reached below detectable limit in 60 days, while herbicide persisted till 112 days in surface soil of fly ash amended plots. No metribuzin leached down to subsurface (15-30cm) soil in fly ash amended plots, while traces of metribuzin (0.6-1.2µg/kg) were recovered in subsurface soil of fly ash unamended plot. Metsulfuron-methyl in surface soil persisted till 15 days in control and 20 days in fly ash amended plots and no metsulfuron-methyl leached down to subsurface soil. Fly ash amendment had no adverse effect on the bioactivity of herbicides and yield of soybean and wheat. The study suggested that fly ash amendment to soil can be exploited to retain applied herbicides in surface soil.


Asunto(s)
Arilsulfonatos/química , Arilsulfonatos/toxicidad , Ceniza del Carbón/farmacología , Suelo/química , Triazinas/química , Triazinas/toxicidad , Arilsulfonatos/análisis , Ceniza del Carbón/química , Herbicidas/análisis , Herbicidas/química , Herbicidas/toxicidad , Contaminantes del Suelo/química , Contaminantes del Suelo/toxicidad , Glycine max/efectos de los fármacos , Factores de Tiempo , Triazinas/análisis , Triticum/efectos de los fármacos
17.
Oncogene ; 32(26): 3184-97, 2013 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-22890320

RESUMEN

Chromatin remodeling proteins regulate multiple aspects of cell homeostasis, making them ideal candidates for misregulation in transformed cells. Here, we explore Sin3A, a member of the Sin3 family of proteins linked to tumorigenesis that are thought to regulate gene expression through their role as histone deacetylases (HDACs). We identified Drosophila Sin3a as an important mediator of oncogenic Ret receptor in a fly model of Multiple Endocrine Neoplasia Type 2. Reducing Drosophila Sin3a activity led to metastasis-like behavior and, in the presence of Diap1, secondary tumors distant from the site of origin. Genetic and Chip-Seq analyses identified previously undescribed Sin3a targets including genes involved in cell motility and actin dynamics, as well as signaling pathways including Src, Jnk and Rho. A key Sin3a oncogenic target, PP1B, regulates stability of ß-Catenin/Armadillo: the outcome is to oppose T-cell factor (TCF) function and Wg/Wnt pathway signaling in both fly and mammalian cancer cells. Reducing Sin3A strongly increased the invasive behavior of A549 human lung adenocarcinoma cells. We show that Sin3A is downregulated in a variety of human tumors and that Src, JNK, RhoA and PP1B/ß-Catenin are regulated in a manner analogous to our Drosophila models. Our data suggest that Sin3A influences a specific step of tumorigenesis by regulating a module of genes involved in cell invasion. Tumor progression may commonly rely on such 'modules of invasion' under the control of broad transcriptional regulators.


Asunto(s)
Neoplasias Pulmonares/patología , Neoplasia Endocrina Múltiple Tipo 2a/patología , Proteínas Represoras/metabolismo , Animales , Línea Celular Tumoral , Movimiento Celular/genética , Transformación Celular Neoplásica , Drosophila , Proteínas de Drosophila/metabolismo , Regulación Neoplásica de la Expresión Génica , Humanos , Proteínas Inhibidoras de la Apoptosis/metabolismo , Proteínas Quinasas JNK Activadas por Mitógenos/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasia Endocrina Múltiple Tipo 2a/metabolismo , Invasividad Neoplásica , Proteínas Proto-Oncogénicas c-ret/metabolismo , Proteínas Represoras/genética , Transducción de Señal , Complejo Correpresor Histona Desacetilasa y Sin3 , Activación Transcripcional , Proteína Wnt1/metabolismo , beta Catenina/metabolismo , Proteína de Unión al GTP rhoA/metabolismo , Familia-src Quinasas/metabolismo
18.
Bull Environ Contam Toxicol ; 89(6): 1133-7, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23052575

RESUMEN

The aim of this study was to quantify the expression level of genes involved in antioxidant defenses during inorganic arsenic (iAs) exposure in the blood of goats and to evaluate the regulative activity on these genes of antioxidant vitamin E in the diet. Twenty-four crossbred lactating goats (Alpine × Beetal) were distributed randomly into four equal groups (Control, T(1), T(2) and T(3)) of six in each, on the basis of average body weight (36.10 ± 0.11 kg) and milk yield (1.61 ± 0.004 kg/day). The animals in T(1), T(2) and T(3) were given 50 mg/kg dry matter arsenic daily, while in T(2) and T(3), vitamin E @100 IU and 150 IU/kg dry matter, respectively, was also supplemented additionally for the period of 12 months. Blood was sampled at 0 day then at 3 months interval and analyzed for the expression level of superoxide dismutase (Cu/Zn SOD) and interleukin-2 (IL-2) using real-time PCR technique. Initially there was no difference (p > 0.05) in relative expression of the two genes. But, at 3 months, relative expression of Cu/Zn SOD increased (p < 0.05) in T(1) groups then, at 6 and 9 months expression was decreased (p < 0.05) in all the iAs treated groups whereas at 12 months, vitamin E supplementation increased (p < 0.05) the expression which is comparable to control groups. IL-2 mRNA expression was decreased (p < 0.05) at 6 months in all iAs treated groups, at 9 months there was decline trend but not significantly different whereas at 12 months decline trend was less (p < 0.05) in vitamin E supplemented groups. The result suggests that vitamin E may have a controlling effect on oxidative stress through modulation of SOD and IL-2 expression.


Asunto(s)
Antioxidantes/farmacología , Arsénico/toxicidad , Sustancias Peligrosas/toxicidad , Interleucina-2/genética , Leucocitos/metabolismo , ARN Mensajero/metabolismo , Superóxido Dismutasa/genética , Vitamina E/farmacología , Animales , Suplementos Dietéticos , Cabras , Interleucina-2/metabolismo , Superóxido Dismutasa/metabolismo
19.
Indian J Exp Biol ; 50(4): 300-7, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22611919

RESUMEN

The incidence pattern of cadmium tolerance and antibiotics resistance by Escherichia coli was examined periodically from the samples of water, sludge and intestine of fish raised in waste stabilization ponds in a sewage treatment plant. Samples of water and sludge were collected from all the selected ponds and were monitored for total counts of fecal coliform (FC), total coliform (TC) and the population of Escherichia coli, which was also obtained from the intestine of fishes. Total counts of both FC and TC as well as counts of E. coli were markedly reduced from the facultative pond to the last maturation pond. Tolerance limit to cadmium by E. coli tended to decline as the distance of the sewage effluent from the source increased; the effective lethal concentration of cadmium ranged from 0.1 mM in split chamber to 0.05 mM in first maturation pond. E. coli isolated from water, sludge and fish gut were sensitive to seven out of ten antibiotics tested. It appears that holistic functions mediated through the mutualistic growth of micro algae and heterotrophic bacteria in the waste stabilization ponds were responsible for the promotion of water quality and significant reduction of coliform along the sewage effluent gradient.


Asunto(s)
Adaptación Fisiológica , Cadmio/toxicidad , Escherichia coli/efectos de los fármacos , Microbiología del Agua , Recuento de Colonia Microbiana , Escherichia coli/fisiología
20.
Bull Environ Contam Toxicol ; 89(1): 61-6, 2012 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-22465959

RESUMEN

The present study was designed to assess whether supplementation of different levels of vitamin E to long-term arsenic exposed goats affords protection against the oxidative stress caused by the metalloid. Twenty-four crossbred lactating goats were distributed randomly into four groups (control, T(1), T(2) and T(3)) of six in each. The animals in T(1), T(2) and T(3) were given 50 mg/kg DM arsenic daily, while in T(2) and T(3), vitamin E @100 IU and 150 IU/kg DM, respectively, was also supplemented additionally for the period of 12 months. Compared to control, significant (p < 0.05) decline in SOD (45 %), CAT activities of erythrocytes (63 %), plasma total Ig (22 %) and total antioxidant activity (24 %) was observed in only arsenic treated groups and vitamin E supplementation in both doses produced partial mitigation effect against SOD (23 %, 20 %) and CAT (39 %, 48 %) while complete mitigation against total Ig (16 %, 7 %) and antioxidant activity (10 %, 8 %) was found. Average lymphocyte stimulation index at the end of experiment was (p < 0.05) lower in arsenic exposed groups (1.003 ± 0.01) and significant (p < 0.05) recovery was observed in response of vitamin E supplementation at higher doses (1.138 ± 0.03). So, vitamin E is helpful in reducing the burden of arsenic induced oxidative stress and activities of antioxidant enzymes in goats.


Asunto(s)
Antioxidantes/farmacología , Arsénico/toxicidad , Suplementos Dietéticos , Sustancias Peligrosas/toxicidad , Estrés Oxidativo/efectos de los fármacos , Vitamina E/farmacología , Animales , Catalasa/metabolismo , Femenino , Cabras , Inmunoglobulinas/sangre , Lactancia/efectos de los fármacos , Superóxido Dismutasa/metabolismo
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