190 research outputs found

    Climbing depth-bounded adjacent discrepancy search for solving hybrid flow shop scheduling problems with multiprocessor tasks

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    This paper considers multiprocessor task scheduling in a multistage hybrid flow-shop environment. The problem even in its simplest form is NP-hard in the strong sense. The great deal of interest for this problem, besides its theoretical complexity, is animated by needs of various manufacturing and computing systems. We propose a new approach based on limited discrepancy search to solve the problem. Our method is tested with reference to a proposed lower bound as well as the best-known solutions in literature. Computational results show that the developed approach is efficient in particular for large-size problems

    Surface-charge-induced freezing of colloidal suspensions

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    Using grand-canonical Monte Carlo simulations we investigate the impact of charged walls on the crystallization properties of charged colloidal suspensions confined between these walls. The investigations are based on an effective model focussing on the colloids alone. Our results demonstrate that the fluid-wall interaction stemming from charged walls has a crucial impact on the fluid's high-density behavior as compared to the case of uncharged walls. In particular, based on an analysis of in-plane bond order parameters we find surface-charge-induced freezing and melting transitions

    Investigation of antioxidant effects of rosmarinic acid on liver, lung and kidney in rats: a biochemical and histopathological study

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    Background: The aim of the study was to investigate the protective effects of rosmarinic acid in rats exposed to hepatic ischaemia/reperfusion (I/R) injury. Materials and methods: Thirty-two rats were randomly classified into four groups of 8 rats each: laparotomy without medication, rosmarinic acid (dose of 50 mg/kg via oral gavage) followed by laparotomy, laparotomy followed by hepatic I/R, and hepatic I/R with rosmarinic acid. Serum aspartate aminotransferase, alaninę aminotransferase, and malondialdehyde levels and total oxidant activity and total antioxidant capacity levels of the liver, lung, and kidney were assessed. The histopathologic assessment was also performed. Results: Rosmarinic acid significantly reduced liver function test parameters and decreased oxidative stress and abnormal histopathologic findings in the liver. The oxidative stress in the lung significantly increased in the I/R group but significantly decreased in the I/R + rosmarinic acid group due to the addition of rosmarinic acid. Rosmarinic acid led to no reduction in oxidative stress in kidney following hepatic I/R injury. There were no statistically significant differences among the groups regarding histopathologic changes in kidney and lung sections. Conclusions: Rosmarinic acid has antioxidant properties and is an effective hepatoprotective agent. However, although rosmarinic acid provides useful effects in the lung by increasing antioxidant capacity and reducing oxidative stress after I/R injury, it does not ameliorate histopathologic changes. These findings suggest that rosmarinic acid is likely to provide favourable outcomes in the treatment of hepatic I/R injury

    Comparison of local rosmarinic acid and topical dexpanthenol applications on wound healing in a rat experimental wound model

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    Background: The aim of the study was to compare the effects of rosmarinic acid and dexpanthenol in a rat experimental wound model.Materials and methods: Twenty-four Wistar albino rats weighing 200–250 g were randomly divided into three groups. After 2-cm full-thickness skin defects were created, the wounds were washed with sterile 0.9% NaCl solution. After washing, the control group was left untreated, the second group received 5% dexpanthenol cream, and the third group received 10% rosmarinic acid cream. Before excision, the skin was evaluated macroscopically by measuring the reduction in wound size; after excision, histological examination (epithelisation, inflammation, fibrosis, granulation) was performed.Results: Macroscopic comparison of the wound sizes showed that group 3 showed a statistically significant difference in wound size reduction compared to the other two groups. Histopathological examination showed that there was no statistically significant difference between the groups. We found that the rosmarinic acid group had greater wound size reduction than the other two groups. However, epithelialisation was detected in fewer cases.Conclusions: We believe that rosmarinic acid can be used as a topical cream for wound healing, as it leads to significant reduction in wound size, resulting in fewer scars

    Evaluation of the Possible Neurotoxic Effect of the Bone Cement on the Facial Nerve: An Experimental Study

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    Objectives To investigate neurotoxic effect of bone cement (BC) on facial nerve by using electrophysiological and histopathological methods. Methods This study included 20 male albino Wistar rats, divided into four equal groups. Group A was designed as the control group, while group B was sham group. In the group C, BC solution was dropped onto the facial nerve trunks of rats and washed with physiological saline after 5 seconds. In the group D, BC solution was dropped onto the facial nerve trunks of rats and after allowing 5 minutes to dry, wounds were closed. Pre- and postoperative (on 4th week) evoked electromyography (EMG) measurements were done. For histopathological assessments, the rats were euthanized and tissue samples of facial nerve and surrounding areas were collected. Results According to the wave amplitude levels of evoked EMG, postoperative amplitude levels of group D were significantly decreased, compared to preoperative amplitude levels (P=0.043). We found no statistically significant difference in inflammation among the groups. In none of the groups, foreign body reaction and granulation tissue were not detected in any of the groups. In addition, degeneration in axon, myelin, or perineural nets was not detected in any of the groups. Conclusion This study results suggest that BC has no direct toxicity on facial nerve, while it has indirect effects, by decreasing amplitude. Therefore, we conclude that direct contact of BC with nerve should be avoided, and the area should be cleaned by aspiration or washing with physiological saline in case of contact

    Energy Consumption, Carbon Emissions and Global Warming Potential of Wolfberry Production in Jingtai Oasis, Gansu Province, China

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    During the last decade, China's agro-food production has increased rapidly and been accompanied by the challenge of increasing greenhouse gas (GHG) emissions and other environmental pollutants from fertilizers, pesticides, and intensive energy use. Understanding the energy use and environmental impacts of crop production will help identify environmentally damaging hotspots of agro-production, allowing environmental impacts to be assessed and crop management strategies optimized. Conventional farming has been widely employed in wolfberry (Lycium barbarum) cultivation in China, which is an important cash tree crop not only for the rural economy but also from an ecological standpoint. Energy use and global warming potential (GWP) were investigated in a wolfberry production system in the Yellow River irrigated Jingtai region of Gansu. In total, 52 household farms were randomly selected to conduct the investigation using questionnaires. Total energy input and output were 321,800.73 and 166,888.80 MJ ha−1, respectively, in the production system. The highest share of energy inputs was found to be electricity consumption for lifting irrigation water, accounting for 68.52%, followed by chemical fertilizer application (11.37%). Energy use efficiency was 0.52 when considering both fruit and pruned wood. Nonrenewable energy use (88.52%) was far larger than the renewable energy input. The share of GWP of different inputs were 64.52% electricity, 27.72% nitrogen (N) fertilizer, 5.07% phosphate, 2.32% diesel, and 0.37% potassium, respectively. The highest share was related to electricity consumption for irrigation, followed by N fertilizer use. Total GWP in the wolfberry planting system was 26,018.64 kg CO2 eq ha−1 and the share of CO2, N2O, and CH4 were 99.47%, 0.48%, and negligible respectively with CO2 being dominant. Pathways for reducing energy use and GHG emission mitigation include: conversion to low carbon farming to establish a sustainable and cleaner production system with options of raising water use efficiency by adopting a seasonal gradient water pricing system and advanced irrigation techniques; reducing synthetic fertilizer use; and policy support: smallholder farmland transfer (concentration) for scale production, credit (small- and low-interest credit) and tax breaks

    Mimicking human neuronal pathways in silico: an emergent model on the effective connectivity

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    International audienceWe present a novel computational model that detects temporal configurations of a given human neuronal pathway and constructs its artificial replication. This poses a great challenge since direct recordings from individual neurons are impossible in the human central nervous system and therefore the underlying neuronal pathway has to be considered as a black box. For tackling this challenge, we used a branch of complex systems modeling called artificial self-organization in which large sets of software entities interacting locally give rise to bottom-up collective behaviors. The result is an emergent model where each software entity represents an integrate-and-fire neuron. We then applied the model to the reflex responses of single motor units obtained from conscious human subjects. Experimental results show that the model recovers functionality of real human neuronal pathways by comparing it to appropriate surrogate data. What makes the model promising is the fact that, to the best of our knowledge, it is the first realistic model to self-wire an artificial neuronal network by efficiently combining neuroscience with artificial self-organization. Although there is no evidence yet of the model's connectivity mapping onto the human connectivity, we anticipate this model will help neuroscientists to learn much more about human neuronal networks, and could also be used for predicting hypotheses to lead future experiments
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