389 research outputs found
Correlation between sleep quality and blood pressure changes in Iranian children
Background: Hypertension has a growing trend all around the world among children. Evidences imply that inadequate sleep duration and its poor quality are related to hypertension. But there are only few studies to show this relationship in children. Objectives: The aim of this study was to investigate the correlation between sleep quality parameters and blood pressure (BP) changes in children. Patients and Methods: Eighty six patients aged 5-15 years old with the history of urinary tract infection were included in this study. They underwent 24-hour BP monitoring. In addition, the Pittsburg Sleep Quality index questionnaire was filled out and the data were compared with BP records. Results: After excluding duplicate cases and those with insufficient data, 76 children entered into study. Overall sleep quality was good in 48 and poor in 28 children. Mean diastolic BP load (P = 0.019), diastolic load Awake-Time (P = 0.045), mean systolic Sleep-Time (P = 0.022), Non-Dipper state (P = 0.009) were statistically different among groups. By dividing the children into two groups of good and poor sleeper, the parameters of BP were not different. In addition, there was no correlation between BP classifications and sleep latency, duration of sleep, sleep efficiency, sleep disturbance, day dysfunction due to sleepiness, and overall sleep quality score. Conclusions: Our study could not show any correlation between sleep quality and ambulatory BP monitoring parameters in children with abnormal BP. © 2015, Iranian Society of Pediatrics
Mechanical properties of dense mycelium-bound composites under accelerated tropical weathering conditions
Mycelium, as the root of fungi, is composed of filamentous strands of fine hyphae that bind discrete substrate particles into a block material. With advanced processing, dense mycelium-bound composites (DMCs) resembling commercial particleboards can be formed. However, their mechanical properties and performance under the working conditions of particleboards are unknown. Here, we show how weathering conditions affect the DMC stress and elastic modulus. DMC was made using Ganoderma lucidum mycelium grown on a substrate of sawdust and empty fruit bunch. The DMC was then subjected to weathering under tropical conditions over 35 days and tested under flexural, tensile, and compressive loading with reference to international standards. After exposure to specified weathering conditions, the maximum stress in flexure, tension, and compression decreased substantially. The addition of a protective coating improved the resistance of DMC to weathering conditions; however, the difference between coated and uncoated samples was only found to be statistically significant in tensile strength
The utilitarian aspect of the philosophy of ecology: The case of corporate social responsibility
This study aims to combine the philosophical perspective and the practical ethics of ecology in the everyday with a more pragmatic concept of corporate social responsibility. The importance of the latter is shown to be based in the abandonment of the distinction of subject and object and the development of personal as well as cultural ecological consciousness embedded in the notion of unity between man and nature. This philosophical shift in the consciousness is also reflected in terms of utility. Hence, the study examines whether the relationship between corporate social responsibility and firm’s sales growth is mediated by competitive advantage, and whether employees’ individual perception in the everyday and beliefs of social responsibility can play a moderating role on CSR-sales growth relationship. The analysis revealed that there is the link between CSR and sales growth and that there is a positive effect of CSR on sales growth which is positively moderated by employees’ individual beliefs of social responsibility which has been implied by the ecological consciousness
Resistance of 14 accessions/cultivars of Lycopersicon spp. to two-spotted spider mite, Tetranychus urticae (Acari: Tetranychidae), in laboratory and greenhouse
Fourteen accessions and cultivars of Lycopersicon spp. were studied to evaluate their resistance to two-spotted spider mite, Tetranychus urticae Koch, under laboratory and greenhouse conditions. In vitro studies were carried out using thumbtack and leaf disk bioassays. Lycopersicon hirsutum and L. pennellii accessions supported more mites on the tack. The highest number of eggs (5.15 ± 0.48 eggs / â / d) was recorded on L. pimpinellifolium LA2533 and the lowest number (0 egg / â / d) was recorded on L. hirsutum and L. pennellii accessions. The highest mite mortality and lowest damage score occurred on the leaf disks of L. pennellii and L. hirsutum accessions that were strikingly in contrast to our observations on L. esculentum varieties (Nandi and Sankranthi). The developmental time of the mite was longest (8.61 ± 0.18 days) on leaf disks of L. esculentum NDTVR-73 and shortest (7.18 ± 0.51 days) on L. pimpinellifolium LA2533. In the greenhouse, the mite was unable to establish on L. hirsutum and L. pennellii accessions. Amongst the rest, Nandi and Sankranthi accessions/cultivars supported the highest, while NDTVR-73 supported the lowest mite population. The highest and lowest density of type VI glandular trichomes were recorded on L. esculentum NDTVR-73 (67.33 ± 6.34 trichomes/mm²) and L. pennellii LA2963 (0.79 ± 0.15 trichomes/mm²), respectively. No relation was found between density of type VI trichomes and resistance to the mite. Type IV glandular trichomes were observed only on the foliages of L. hirsutum and L. pennellii. A positive relation exists between the density of type IV glandular trichomes and resistance to the mite
Application of exploratory factor analysis method in the evaluating the competitiveness of port services
This applied research has been conducted to evaluate the competitiveness of port services using exploratory factor analysis and importance- performance analysis methods. First, by studying the ports competiveness literatures, 53 indicators of competitiveness of port services has been identified, And to reduce the number of variables affecting the competitiveness of ports and the formation of a new structure for them (Based on the correlations between variables), exploratory factor analysis method was used. Based on the obtained results from 53 identified indicators, in the factor analysis, only 27 of indicator have loadings on the eight factors of Logistics Cost, Connectivity, Port facility, Port Service and Availability, Safety and security, Efficiency and Productivity, Reliability, Hinterland condition. The obtained results from confirmatory factor analysis in this study showed that, among the eight factors, factors of Logistics Cost and factors of Connectivity have greatest influence on the port competitiveness. And factors of Reliability and factors of Hinterland condition have least influence on the port competitiveness. And also the results of the importance and performance analysis showed that among of eight factors, respectively efficiency and productivity factor has the highest and Hinterland condition has the lowest the difference between the performance averages from importance average. And also the Position of each factor in the quarters of the importance and performance matrix indicates that other than the second factor (Connectivity) and fifth factor (Safety and Security) all other factors located in a quarter one. Thus it can be concluded that the services of studies port from the perspective of located factors in quarter one (logistics costs, port facilities, port services, productivity and efficiency, reliability and the Hinterland) has a low performance And needs performance improvement according to their importance
EBSD Study of Damage Mechanisms in a High-Strength Ferrite-Martensite Dual-Phase Steel
Electron backscattered diffraction (EBSD) analyses were performed on a fine-grained dual-phase (DP) sheet steel subjected to uniform tensile deformation and the preferred void nucleation sites as well as the micro-mechanisms of void formation were examined. EBSD study of grain average misorientation, grain orientation spread and kernel average misorientation of the deformed microstructure revealed that voids nucleation initially happened at ferrite-martensite interfaces neighboring rather large ferrite grains. This is believed to be mainly due to the higher shear deformation ability of the larger ferrite grains, the higher number of dislocation pile-ups at the martensite particles and the less uniform strain distribution within the larger ferrite grains compared to the smaller ones. The results demonstrated the impact of increasing uniform strain distribution within the DP microstructure on lowering the void nucleation probability.open111112sciescopu
Identification and ranking of causes of delay in container handling operation by TOPSIS method
This applied research has been conducted to identify and rank the causes of delay in container handling operation in two stages. In the first, having considered the daily census of container handling operation in the pertinent terminal of the port, As well, brain storming cessions attended by experts from the studied container terminals were held during which twenty seven numbers of causes of delay were detected. In the second stage, having considered the detected factors from the first stage, the probability of the causes occurrence, the extent of impact of causes on process after their occurrence and probability of causes detection before having effect on process have been determined by experts in form of a scale ranging from one to ten, Finally based on the obtained scores by each one of the causes, the decision matrix was formed and the mentioned causes were ranked by TOPSIS method. The abstained results showed that the causes of delays in loading and unloading operations in studied container terminals have significant different in the terms of probability of the causes occurrence, the extent of impact of causes on process after their occurrence and probability of causes detection before having effect on process. Finally to mitigation of these causes several strategies have been presented
A comparison between three conditioning factors dataset for landslide prediction in the sajadrood catchment of iran
This study investigates the effectiveness of three datasets for the prediction of landslides in the Sajadrood catchment (Babol County, Mazandaran Province, Iran). The three datasets (D1, D2 and D3) are constructed based on fourteen conditioning factors (CFs) obtained from Digital Elevation Model (DEM) derivatives, topography maps, land use maps and geological maps. Precisely, D1 consists of all 14 CFs namely altitude, slope, aspect, topographic wetness index (TWI), terrain roughness index (TRI), distance to fault, distance to stream, distance to road, total curvature, profile curvatures, plan curvature, land use, steam power index (SPI) and geology. D2, on the other hand, is a subset of D1, consisting of eight CFs. This reduction was achieved by exploiting the Variance Inflation Factor, Gini Importance Indices and Chi-Square factor optimization methods. Dataset D3 includes only selected factors derived from the DEM. Three supervised classification algorithms were trained for landslide prediction namely the Support Vector Machine (SVM), Logistic Regression (LR), and Artificial Neural Network (ANN). Experimental results indicate that D2 performed the best for landslide prediction with the SVM producing the best overall accuracy at 82.81%, followed by LR (81.71%) and ANN (80.18%). Extensive investigations on the results of factor optimization analysis indicate that the CFs distance to road, altitude, and geology were significant contributors to the prediction results. Land use map, slope, total-, plan-, and profile curvature and TRI, on the other hand, were deemed redundant. The analysis also revealed that sole reliance on Gini Indices could lead to inefficient optimization
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