A dynamic neighborhood learning-based gravitational search algorithm

Balancing exploration and exploitation according to evolutionary states is crucial to meta-heuristic search (M-HS) algorithms. Owing to its simplicity in theory and effectiveness in global optimization, gravitational search algorithm (GSA) has attracted increasing attention in recent years. However, the tradeoff between exploration and exploitation in GSA is achieved mainly by adjusting the size of an archive, named Kbest, which stores those superior agents after fitness sorting in each iteration. Since the global property of Kbest remains unchanged in the whole evolutionary process, GSA emphasizes exploitation over exploration and suffers from rapid loss of diversity and premature convergence. To address these problems, in this paper, we propose a dynamic neighborhood learning (DNL) strategy to replace the Kbest model and thereby present a DNL-based GSA (DNLGSA). The method incorporates the local and global neighborhood topologies for enhancing the exploration and obtaining adaptive balance between exploration and exploitation. The local neighborhoods are dynamically formed based on evolutionary states. To delineate the evolutionary states, two convergence criteria named limit value and population diversity, are introduced. Moreover, a mutation operator is designed for escaping from the local optima on the basis of evolutionary states. The proposed algorithm was evaluated on 27 benchmark problems with different characteristic and various difficulties. The results reveal that DNLGSA exhibits competitive performances when compared with a variety of state-of-the-art M-HS algorithms. Moreover, the incorporation of local neighborhood topology reduces the numbers of calculations of gravitational force and thus alleviates the high computational cost of GSA

The growing inequality between firms

Globalisation, technological progress and a range of policies and institutions are driving ‘Great Divergences’ in wages and productivity, write Giuseppe Berlingieri, Patrick Blanchenay and Chiara Criscuol

Influence of diabetes on cardiac resynchronization therapy in heart failure patients: a meta-analysis

BACKGROUND: Diabetes mellitus is an independent risk factor of increased morbidity and mortality in patients with heart failure. Cardiac resynchronization therapy (CRT), a pacemaker-based therapy for dyssynchronous heart failure, improves cardiac performance and quality of life, but its effect on mortality in patients with diabetes is uncertain. METHODS: We performed a meta-analysis of results from randomized controlled trials (RCTs) of the long-term outcome of cardiac resynchronization therapy for heart failure in diabetic and non-diabetic patients. Literature search of MEDLINE via Pubmed for reports of randomized controlled trials of Cardiac resynchronization for chronic symptomatic left-ventricular dysfunction in patients with and without diabetes mellitus, with death as the outcome. Relevant data were analyzed by use of a random-effects model. Reports published from 1994 to 2011 that described RCTs of CRT for treating chronic symptomatic left ventricular dysfunction in patients with and without diabetes, with all-cause mortality as an outcome. RESULTS: A total of 5 randomized controlled trials met the inclusion criteria, for 2,923 patients. The quality of studies was good to moderate. Cardiac resynchronization significantly reduced the mortality for heart failure patients with or without diabetes mellitus. Mortality was 24.3% for diabetic patients with heart failure and 20.4 % for non-diabetics (odds ratio 1.28, 95% confidence interval 1.06–1.55; P = 0.010). CONCLUSIONS: Cardiac resynchronization therapy (CRT) may reduce mortality from progressive heart failure in patients with or without diabetes mellitus, but mortality may be higher for patients with than without diabetes after CRT for heart failure

Detecting and Tracking Hair Impurities in Mushroom Semi-product Images

A new area operator was proposed to extract axes feature of hair impurity in mushroom semi-product images. This operator was based on the local intensity comparison, and it had two advantages: 1) its outputs reached local maxima at the hair axes; 2) the accurate direction information of the hair axes could be derived by it. After the axes feature of the hairs was extracted using the proposed operator, an extended Kalman filter was applied to track the hairs. The searching path was established when a cost function was minimized. Starting points of the tracking path were found using dyadic wavelet analysis. The proposed algorithm had good adaptivity for the arbitrary orientation of the hairs. The experiment results showed that hairs could be tracked accurately. DOI: http://dx.doi.org/10.11591/telkomnika.v11i11.354

Compositional and Functional Changes in Microbial Communities of Composts Due to the Composting-Related Factors and the Presence of \u3ci\u3eListeria monocytogenes\u3c/i\u3e

Listeria monocytogenes is a leading foodborne pathogen that can contaminate fresh produce in farm environment, resulting in deadly outbreaks. Composts contain a diversity of microorganisms, and some of them may be compost-adapted competitive exclusion microorganisms against L. monocytogenes. To understand interactions between compost microflora and the pathogen, both dairy- and poultry-wastes based composts (n = 12) were inoculated with L. monocytogenes, and then analyzed by next-generation sequencing approaches along with culturing methods. DNA extraction and enumeration of L. monocytogenes were performed at 0 and 72 h post-incubation at room temperature. The major bacterial phyla were identified as Firmicutes (23%), Proteobacteria (23%), Actinobacteria (19%), Chloroflexi (13%), Bacteroidetes (12%), Gemmatimonadetes (2%), and Acidobacteria (2%). The top three indicator genera enriched in different compost types were identified by LEfSe with LDA score . 2. The interactions between L. monocytogenes and indigenous microflora were limited as no significant changes in the dominant microbial members in compost ecosystem, but some discriminatory species such as Bacillus, Geobacillus, and Brevibacterium were identified by Random Forest analysis. Besides, changes in metabolic pathways and the increased abundance of bacteriocins category in the compost samples containing L. monocytogenes after 72 h postinoculation were revealed by metatranscriptomic sequencing. Taken together, the compost-related factors such as compost types, composting stages, and the collection farms are major drivers that affect compost microbial compositions, and the analysis of compost metagenome implied that interactions between L. monocytogenes and compost microflora may include competition for nutrients and the presence of antimicrobials

Baicalein administration protects against pentylenetetrazole-induced chronic epilepsy in rats

Purpose: To investigate the protective effect of baicalein against chronic seizures in pentylenetetrazole induced epilepsy in a rat model.Methods: A rat model of chronic epilepsy was prepared by administration of pentylenetetrazole at a dose of 35 mg/kg to Sprague-Dawley rats. The animals were divided into 6 groups (5 rats/group): normal control, model (untreated epilepsy) and four treatment groups that received separately, intraperitoneal injection of 20, 30, 40 and 50 mg/kg baicalein, respectively, on alternate days for 30 days. On each day following baicalein treatment, behavioural alterations in the  rats were assessed.Results: Analyses of behavioural changes revealed significant (p < 0.05) decrease in pentylenetetrazole-induced convulsions by baicalein treatment at a dose of 50 mg/kg. Immunohistochemical studies revealed that treatment with baicalein caused significant (p < 0.05) dosedependent reductions in the levels of inducible nitric oxide synthase (iNOS). Baicalein treatment inhibited alterations in cell morphology, and also inhibited pentylenetetrazole-induced increase in the proportion of glial fibrillary acidic protein (GFAP)-positive cells in a dose-dependent manner (p < 0.05). Real-time polymerase chain reaction (RT-PCR) analysis showed that baicalein significantly inhibited the expression of mRNA of NR1 subunit N methyl D aspartic acid (NMDA) receptor, without any effect on the expression of the NR2b (N-methyl D-aspartate receptor subtype 2B ) subunit mRNA (p < 0.05).Conclusion: These results indicate that baicalein inhibits pentylenetetrazole-induced chronic seizures in rats via reduction in astrocytes, inhibition of neuronal death and reduction of NR1 mRNA expression. Thus, baicalein has a potential for development into a new drug for the treatment of chronic epilepsy.Keywords: Pentylenetetrazole, Epilepsy, Baicalein, Convulsion, Inhibition, behavioural changes, Hippocampu