Spectral variability in NGC 1042 ULX1

We report X-ray spectral variability in an ultraluminous X-ray source NGC 1042 ULX1, using archival XMM-Newton and recent NuSTAR observations. In long-term evolution, the source has shown a trend of variation in spectral hardness. The variability in different XMM-Newton observations is prominent above $\sim 1$ keV. Cool thermal disk component with a characteristic temperature of $\sim 0.2$ keV manifests that the spectral state of NGC 1042 ULX1 in all epochs is similar to that of the ultraluminous state sources. An apparent anti-correlation between luminosity and powerlaw index demonstrates that the source becomes spectrally harder when it is in a brighter state. That is conceivably related to variation in accretion rate, strength of comptonization, wind/outflow in the system or a manifestation of varying disk occultation. Typical hard ultraluminous type spectra indicate that NGC 1042 ULX1 is a low inclination system in general. Spectral properties suggest that, like many other ULXs which show spectral curvature around $\sim 6-10$ keV, NGC 1042 ULX1 could be another stellar-mass super-Eddington accretor.Comment: 9 pages, 5 figures, accepted for publication in MNRA

Genetics of asthma: current research paving the way for development of personalized drugs

Asthma is a complex genetic disorder involving the interplay between various environmental and genetic factors. In this review, efforts have been made to provide information on the recent advances in these areas and to discuss the future perspective of research in the area of developing personalized drugs using pharmacogenomic approach. Atopic asthma is found to be strongly familial, however the mode of inheritance is controversial. A large number of studies have been carried out and a number of candidate genes have been identified. In addition, a number of chromosomal regions have been identified using genome-wide scans, which might contain important unknown genes. It has been shown in studies carried out in different populations that the genetic predisposition varies with ethnicity. In other words, genes that are associated with asthma in one population may not be associated with asthma in another population. In addition to the involvement of multiple genes, gene-gene interactions play a significant role in asthma. The importance of environmental factors in asthma is beyond doubt. However, it remains controversial whether a cleaner environment or increased pollution is a trigger for asthma. Despite the increasing prevalence of the disorder, only a limited number of therapeutic modalities are available for the treatment. A number of novel therapeutic targets have been identified and drugs are being developed for better efficacy with less side-effects. With the rapid progress in the identification of genes involved in various ethnic populations combined with the availability in future of well-targeted drugs, it will be possible to have appropriate medicine as per the genetic make-up of an individual

Is Diabetes Pre-coded in the Brain? Role of Hypothalamus, Addiction Network and Social Cognition

The hypothalamus, the master regulator of circadian rhythm, in association with peripheral clocks, play crucial roles in glucose metabolism. Impairment in cerebral sensing, uptake and processing of glucose has been suggested in various animal and human diabetic models. Diabetes Mellitus has been largely superseded by the discovery of insulin and insulin resistance. Expanding horizons of knowledge of the roles of the hypothalamus in glucose metabolism and the overlapping neural pathways of sugar addictionwith other classically described substance and behavioral addictions networks have again thrown some light on the cerebral theory of DM pathogenesis

Investigation of ZnO nanoparticles for their applications in wastewater treatment and antimicrobial activity

The photocatalytic as well as the antimicrobial activity of the synthesized ZnO nanoparticles (ZnO-NPs) through solution based approach have been presented in this study. ZnO-NPs have been characterised by thermogravimetry/differential thermal analysis (TG/DTA), ultraviolet-visible (UV–Vis), Fourier transform infrared (FTIR) and Raman spectroscopy. Raman studies confirm that it has stable wurtzite structure. FTIR spectrum confirms the Zn–O band at ~460 cm-1. Optical studies reveal that the optical band gap value increases with increasing annealing temperature. The photocatalytic activity of the ZnO-NPs has been evaluated for removal of pollutants from wastewater by measuring COD and BOD. Results show that ZnO-NPs are capable of working efficiently for waste water treatment. ZnO-NPs also demonstrate antimicrobial activity against gram-positive and gram-negative bacterial strains

Fatty Acid Concentration and Phase Transitions Modulate Aβ Aggregation Pathways

Aggregation of amyloid β (Aβ) peptides is a significant event that underpins Alzheimer disease (AD) pathology. Aβ aggregates, especially the low-molecular weight oligomers, are the primary toxic agents in AD and hence, there is increasing interest in understanding their formation and behavior. Aggregation is a nucleation-dependent process in which the pre-nucleation events are dominated by Aβ homotypic interactions. Dynamic flux and stochasticity during pre-nucleation renders the reactions susceptible to perturbations by other molecules. In this context, we investigate the heterotypic interactions between Aβ and fatty acids (FAs) by two independent tool-sets such as reduced order modelling (ROM) and ensemble kinetic simulation (EKS). We observe that FAs influence Aβ dynamics distinctively in three broadly-defined FAconcentration regimes containing non-micellar, pseudo-micellar or micellar phases. While the non-micellar phase promotes on-pathway fibrils, pseudo-micellar and micellar phases promote predominantly off-pathway oligomers, albeit via subtly different mechanisms. Importantly off-pathway oligomers saturate within a limited molecular size, and likely with a different overall conformation than those formed along the on-pathway, suggesting the generation of distinct conformeric strains of Aβ, which may have profound phenotypic outcomes. Our results validate previous experimental observations and provide insights into potential influence of biological interfaces in modulating Aβ aggregation pathways

A Game-Theoretic Approach to Deciphering the Dynamics of Amyloid-Beta Aggregation Along Competing Pathways

Aggregation of amyloid-β (Aβ) peptides is a significant event that underpins Alzheimer\u27s disease (AD). Aβ aggregates, especially the low-molecular weight oligomers, are the primary toxic agents in AD pathogenesis. Therefore, there is increasing interest in understanding their formation and behaviour. In this paper, we use our previously established results on heterotypic interactions between Aβ and fatty acids (FAs) to investigate off-pathway aggregation under the control of FA concentrations to develop a mathematical framework that captures the mechanism. Our framework to define and simulate the competing on- and off-pathways of Aβ aggregation is based on the principles of game theory. Together with detailed simulations and biophysical experiments, our models describe the dynamics involved in the mechanisms of Aβ aggregation in the presence of FAs to adopt multiple pathways. Specifically, our reduced-order computations indicate that the emergence of off- or on-pathway aggregates are tightly controlled by a narrow set of rate constants, and one could alter such parameters to populate a particular oligomeric species. These models agree with the detailed simulations and experimental data on using FA as a heterotypic partner to modulate the temporal parameters. Predicting spatio-temporal landscape along competing pathways for a given heterotypic partner such as lipids is a first step towards simulating scenarios in which the generation of specific ‘conformer strains’ of Aβ could be predicted. This approach could be significant in deciphering the mechanisms of amyloid aggregation and strain generation, which are ubiquitously observed in many neurodegenerative diseases