537 research outputs found
Effect of drought stress on yield, proline and chlorophyll contents in three chickpea cultivars
Drought stress is one of the major abiotic stresses in agriculture worldwide. This study was carried out to investigate the effect of drought stress on proline content, chlorophyll content, photosynthesis and transpiration, stomatal conductance and yield characteristics in three varieties of chickpea (drought tolerant Bivaniej and ILC482 and drought sensitive Pirouz). A field experiment with four irrigation regimes was carried out in a randomized complete block design with three replications. Treatments included control (no drought),drought stress imposed during the vegetative phase, drought stress imposed during anthesis and drought stress during the vegetative phase and during anthesis. All physiological parameters were affected by drought stress. Drought stress imposed during vegetative growth or anthesis significantly decreased chlorophyll a, chlorophyll b and total chlorophyll content. Proline accumulation was higher in âILC482â than in âPirouzâ both under control and drought stress conditions. Photosynthesis, transpiration, stomatal conductance and yield were higher but sub-stomatal CO2 concentration was lower under drought stress conditions than under control conditions. The results showed that mesophyll resistance is the basic determinate of rate of phototosynthesis under drought stress conditions. Under drought conditions the drought tolerant variety âBivaniejâ gave the highest yield whereas the drought sensitive variety âPirouzâ gave the lowest yield. Drought stress at anthesis phase reduced seed yield more severe than that on vegetative stag
Effect of drought stress and subsequent recovery on protein, carbohydrate contents, catalase and peroxidase activities in three chickpea (Cicer arietinum) cultivars
Drought stress is one of the major abiotic stresses in agriculture worldwide. This study was carried out to investigate the effects of drought stress and subsequent recovery on protein, carbohydrate content, catalase (CAT), and peroxidase (POX) activities in three varieties of chickpea (drought tolerant Bivaniej and ILC482 and drought sensitive Pirouz). A field experiment with four irrigation regimes was carried out in a randomized complete block design with three replications. Treatments included control (well-watering), drought stress imposed during the vegetative phase, drought stress imposed during anthesis and drought stress during the vegetative phase and anthesis. Drought stress imposed during vegetative growth or anthesis significantly decreased soluble protein content and increased water soluble carbohydrate concentration. The tolerant variety accumulated more soluble carbohydrate than the sensitive one. Drought stress at flowering stage had significantly higher POX activity compared to than that at vegetative stage. Compared with the stress, there was significantly more soluble protein after exposure to recovery conditions but POX decreased in all three varieties. These results suggest that CAT and POX activities play an essential protective role against drought stress in chickpea. Antioxidants act as a major defense against radical mediated toxicity by protecting the damages caused by free radicals. An increase was observed in POX and CAT activity of three cultivars under stress conditions throughout the experiment. Results showed that POX acts as the major antioxidant enzyme in chickpea leaves under oxidative stress condition. So activity of this enzyme in stress condition can be used as an index for chickpea cultivars tolerance assessment
Effects of aflatoxin B1 on growth performance, health indices, phagocytic activity and histopathological alteration in Fenneropenaeus indicus
Mycotoxins contamination of feedstuff for aquatic animals is common in regions with humid tropical conditions. In this study Indian white shrimp, Fenneropenaeus indicus, (11.79 Âą 1.76 g) were fed with diets containing 0, 20, 50, 100, 200, 400, 800 and 1600 ppb levels of aflatoxin B1 (AFLB1) for 8 weeks. Final weight, aflatoxin B1 residue (2-week intervals), Total Hemocyte Count (THC), Total Plasma Protein (TPP), Phagocytic Activity (PA), Survival rate (4-week intervals) were determined. Histopathological alterations in hepatopancreas, midgut and muscle tissues were studied at the end of 4 and 8 weeks. Shrimps fed with the 1600, 800 and 400 ppb concentrations of AFLB1 exhibited slow growth, and more reddish discoloration disseminated over the body at 4th week. Growth parameters, survival rate and health indices (THC, TPP) of F. indicus, are affected by the different doses of AFLB1 in diets. At the end of 8th week, doses of AFLB1 in the diets showed negative correlation to final weight, survival rate, THC and TPP (r = - 0.312, -0.603, -0.237 and - 0.649 at P<0.001, respectively). Moreover, significant histopathological alterations in the hepatopancreas, midgut and muscle tissues of exposed shrimps to different levels of AFLB1 were observed and these alterations are obviously indicated by changes in the health indexes (THC and TPP)
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Evaluate the Safety Effects of Adopting a Stop-as-Yield Law for Cyclists in California
The escalating number of injuries and fatalities among cyclists is a pressing safety concern. In the United States, communities are actively seeking strategies to boost cyclist safety, with some states implementing bike-specific policies, such as stop-as-yield laws, to support cyclists. Stop-as-yield laws allow cyclists to treat stop signs as yield signs. The laws are not yet widely implemented, and their potential safety impact is a subject of debate among transportation experts and advocates. This study investigates how stop-as-yield laws can positively or negatively affect safety and provides insights and guidelines for California policymakers and safety practitioners if the law passes in California. We collected cyclist data from five states that have enacted stop-as-yield lawsâIdaho, Arkansas, Oregon, Washington and Delawareâand data from some of their contiguous states without such legislation. Using an observational before-after study with comparison groups at the state level, the research examined changes in cyclist crash frequencies after the laws were implemented. Additionally, a random-effects negative binomial regression model with panel data was employed to estimate a lawâs overall impact. The results did not indicate a significant change in cyclist crashes among the states with stop-as-yield laws
Intense physical activity is associated with cognitive performance in the elderly
Numerous studies have reported positive impacts of physical activity on cognitive function. However, the majority of these studies have utilised physical activity questionnaires or surveys, thus results may have been influenced by reporting biases. Through the objective measurement of routine levels of physical activity via actigraphy, we report a significant association between intensity, but not volume, of physical activity and cognitive functioning. A cohort of 217 participants (aged 60â89 years) wore an actigraphy unit for 7 consecutive days and underwent comprehensive neuropsychological assessment. The cohort was stratified into tertiles based on physical activity intensity. Compared with individuals in the lowest tertile of physical activity intensity, those in the highest tertile scored 9%, 9%, 6% and 21% higher on the digit span, digit symbol, Rey Complex Figure Test (RCFT) copy and Rey Figure Test 30-min recall test, respectively. Statistically, participants in the highest tertile of physical activity intensity performed significantly better on the following cognitive tasks: digit symbol, RCFT copy and verbal fluency test (all P<0.05). The results indicate that intensity rather than quantity of physical activity may be more important in the association between physical activity and cognitive function
Predicting the Readmission of Heart Failure Patients through Data Analytics
Reducing the costs and improving the quality of treatment in hospital systems as well as demands for better treatment from patients in order to keep them away from readmissions are two main issues healthcare systems have faced. In order to solve such challenges, predicting the occurrence of re-hospitalisation with data mining techniques would be so worthwhile. In this study, we are seeking to predict the occurrence of re-hospitalisation of the heart failure patients in two time-horizons (1-month and 3-month) via deployment of classification algorithms (i.e. decision trees, artificial neural networks, support vector machines and logistic regression). Two criterions (as main criterions) such as AUC (area under curve) and ACC (accuracy) have been calculated and assessed for classifying the prediction-power of the models in each time-horizon (outcome/target). We also have calculated some other criterions such as recall, precision and F1-Score. Then, we identified the importance and contribution of the variables for each outcome. Therefore, the variables whose contribution/importance changes over time are differentiated. It is noteworthy to say that this study is done under the scrutiny of an expert cardiologist. Trained nurses and expert cardiologist monitored the dataset every day, which was a hard and valuable measure to conduct. Finally, the dataset does not have missing values and noises. This research can be the basis for prospective medical studies and projects. ĂŠ 2019 World Scientific Publishing Co
Examining the potential clinical value of curcumin in the prevention and diagnosis of Alzheimer\u27s disease
Curcumin derived from turmeric is well documented for its anti-carcinogenic, antioxidant and anti-inflammatory properties. Recent studies show that curcumin also possesses neuroprotective and cognitive-enhancing properties that may help delay or prevent neurodegenerative diseases, including Alzheimerâs disease (AD). Currently, clinical diagnosis of AD is onerous, and it is primarily based on the exclusion of other causes of dementia. In addition, phase III clinical trials of potential treatments have mostly failed, leaving disease-modifying interventions elusive. AD can be characterised neuropathologically by the deposition of extracellular β amyloid (Aβ) plaques and intracellular accumulation of tau-containing neurofibrillary tangles. Disruptions in Aβ metabolism/clearance contribute to AD pathogenesis. In vitro studies have shown that Aβ metabolism is altered by curcumin, and animal studies report that curcumin may influence brain function and the development of dementia, because of its antioxidant and anti-inflammatory properties, as well as its ability to influence Aβ metabolism. However, clinical studies of curcumin have revealed limited effects to date, most likely because of curcuminâs relatively low solubility and bioavailability, and because of selection of cohorts with diagnosed AD, in whom there is already major neuropathology. However, the fresh approach of targeting early AD pathology (by treating healthy, pre-clinical and mild cognitive impairment-stage cohorts) combined with new curcumin formulations that increase bioavailability is renewing optimism concerning curcumin-based therapy. The aim of this paper is to review the current evidence supporting an association between curcumin and modulation of AD pathology, including in vitro and in vivo studies. We also review the use of curcumin in emerging retinal imaging technology, as a fluorochrome for AD diagnostics
The effect of magnesium on bioactivity, rheology and biology behaviors of injectable bioactive glass-gelatin-3-glycidyloxypropyl trimethoxysilane nanocomposite-paste for small bone defects repair
Injectable bioactive glass-based pastes represent promising biomaterials to fill small bone defects thus improving and speed up the self-healing process. Accordingly, injectable nanocomposite pastes based on bioactive glass-gelatin-3-glycidyloxypropyl trimethoxysilane (GPTMS) were here synthesized via two different glasses 64SiO2. 27CaO. 4MgO. 5P2O5 (mol.%) and 64SiO2.31CaO. 5P2O5 (mol.%). In particular, the effects of MgO on bioactivity, rheology, injectability, disintegration resistance, compressive strength and cellular behaviors were investigated. The results showed that the disintegration resistance and compressive strength of the composite were improved by the replacement of MgO; thus, leading to an increase in the amount of storage modulus (Gâ˛) from 26800 to 43400 Pa, equal to an increase in the viscosity of the paste from 136 Ă 103 to 219 Ă 103 Pa s. Since the release rate of ions became more controllable, the formation of calcite was decreased after immersion of the Mg bearing samples in the SBF solution. Specimensâ cytocompatibility was firstly verified towards human osteoblasts by metabolic assay as well as visually confirmed by the fluorescent live/dead staining; finally, the ability of human fibroblasts to penetrate within the pores of 3D composites was verified by a migration assay simulating the devices repopulation upon injection in the injured site
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