Cooperative effect of random and time-periodic coupling strength on synchronization transitions in one-way coupled neural system: mean field approach

The cooperative effect of random coupling strength and time-periodic coupling strengh on synchronization transitions in one-way coupled neural system has been investigated by mean field approach. Results show that cooperative coupling strength (CCS) plays an active role for the enhancement of synchronization transitions. There exist an optimal frequency of CCS which makes the system display the best CCS-induced synchronization transitions, a critical frequency of CCS which can not further affect the CCS-induced synchronization transitions, and a critical amplitude of CCS which can not occur the CCS-induced synchronization transitions. Meanwhile, noise intensity plays a negative role for the CCS-induced synchronization transitions. Furthermore, it is found that the novel CCS amplitude-induced synchronization transitions and CCS frequency-induced synchronization transitions are found.     

Comparative analysis of different dietary antioxidants on oxidative stress pathway genes in L6 myotubes under oxidative stress

Enhanced oxidative stress plays an important role in the progression and onset of diabetes and its complications. Strategies or efforts meant to reduce the oxidative stress are needed which may mitigate these pathogenic processes. The present study aims to investigate the in vitro ameliorative potential of nine antioxidant molecules in L6 myotubes under oxidative stress condition induced by 4-hydroxy-2-nonenal and also to comprehend the gene expression patterns of oxidative stress genes upon the supplementation of different antioxidants in induced stress condition. The study results demonstrated a marked increase in the level of malondialdehyde and protein carbonyl content with a subsequent increase in the free radicals that was reversed by the pretreatment of different dietary antioxidant. From the expression analysis of the oxidative stress genes, it is evident that the expression of these genes is modulated by the presence of antioxidants. The highest expression was found in the cells treated with Insulin in conjugation with an antioxidant. Resveratrol is the most potent modulator followed by Mangiferin, Estragole, and Capsaicin. This comparative analysis ascertains the potency of Resveratrol along with Insulin in scavenging the reactive oxygen species (ROS) generated under induced stress conditions through antioxidant defense mechanism against excessive ROS production, contributing to the prevention of oxidative damage in L6 myotubes.     

A Semiotic Interpretation of the Innate Releasing Mechanism Concept and Other Ethological Triadic Relations

This paper tries to link Ethology to Biosemiotics by analysing the similarities between some triadic relationships like biosemiotics’ Object—Representamen—Interpretant and the one established in Ethology between Sign-stimuli— Innate Releasing Mechanism—Modal Action Pattern, or the one potentially established in communication networks comprising Sender—Receiver—Eavesdropper. I argue here that a collaborative relationship is supported by the fact that the observational method used by Ethology is based on the triadic relationship Sender—Receiver—Eavesdropper (Interpreter). This method, by introducing the human observer at the Interpreter/Eavesdropper place, is not only applicable to the direct study of animal communication, but also to the interpretation of all other animal behaviour by assuming that behaviour is a sign/signal system on its own, for us to interpret and decode.     

Q&A: Friends (but sometimes foes) within: the complex evolutionary ecology of symbioses between host and microbes

Over the past decade, there has been a pronounced shift in the study of host–microbe associations, with recognition that many of these associations are beneficial, and often critical, for a diverse array of hosts. There may also be pronounced benefits for the microbes, though this is less well empirically understood. Significant progress has been made in understanding how ecology and evolution shape simple associations between hosts and one or a few microbial species, and this work can serve as a foundation to study the ecology and evolution of host associations with their often complex microbial communities (microbiomes).     

Retinol (Vitamin A) Increases α-Synuclein, β-Amyloid Peptide,Tau Phosphorylation and RAGE Content in Human SH-SY5Y Neuronal Cell Line

Retinoids (vitamin A and derivatives) are recognized as essential factors for central nervous system (CNS) development. Retinol (vitamin A) also was postulated to be a major antioxidant component of diet as it modulates reactive species (RS) production and oxidative stress in biological systems. Oxidative stress plays a major role either in pathogenesis or development of neurodegenerative diseases, or even in both. Here we investigate the role of retinol supplementation to human neuron-derived SH-SY5Y cells over RS production and biochemical markers associated to neurodegenerative diseases expressed at neuronal level in Parkinson’s disease and Alzheimer’s disease: α-synuclein, β-amyloid peptide, tau phosphorylation and RAGE. Retinol treatment (24 h) impaired cell viability and increased intracellular RS production at the highest concentrations (7 up to 20 µM). Antioxidant co-treatment (Trolox 100 µM) rescued cell viability and inhibited RS production. Furthermore, retinol (10 µM) increased the levels of α-synuclein, tau phosphorylation at Ser396, β-amyloid peptide and RAGE. Co-treatment with antioxidant Trolox inhibited the increased in RAGE, but not the effect of retinol on α-synuclein, tau phosphorylation and β-amyloid peptide accumulation. These data indicate that increased availability of retinol to neurons at levels above the cellular physiological concentrations may induce deleterious effects through diverse mechanisms, which include oxidative stress but also include RS-independent modulation of proteins associated to progression of neuronal cell death during the course of neurodegenerative diseases.     

Determination of glucose exchange rates and permeability of erythrocyte membrane in preeclampsia and subsequent oxidative stress-related protein damage using dynamic-<Superscript>19</Superscript>F-NMR

The cause of the pregnancy condition preeclampsia (PE) is thought to be endothelial dysfunction caused by oxidative stress. As abnormal glucose tolerance has also been associated with PE, we use a fluorinated-mimic of this metabolite to establish whether any oxidative damage to lipids and proteins in the erythrocyte membrane has increased cell membrane permeability. Data were acquired using ¹⁹F Dynamic-NMR (DNMR) to measure exchange of 3-fluoro-3-deoxyglucose (3-FDG) across the membrane of erythrocytes from 10 pregnant women (5 healthy control women, and 5 from women suffering from PE). Magnetisation transfer was measured using the 1D selective inversion and 2D EXSY pulse sequences, over a range of time delays. Integrated intensities from these experiments were used in matrix diagonalisation to estimate the values of the rate constants of exchange and membrane permeability. No significant differences were observed for the rate of exchange of 3-FDG and membrane permeability between healthy pregnant women and those suffering from PE, leading us to conclude that no oxidative damage had occurred at this carrier-protein site in the membrane.