Detection of Quinolone resistance Qnr genes and its association with Extended Spectrum β-lactamase and AmpC β-lactamase genes in Qnr Positive Enterobacteriaceae in Bangladesh

This cross-sectional study was conducted to explore quinolone resistant Enterobacteriaceae followed by searching the prevalence of three groups of quinolone resistance genes (QnrA, QnrB and QnrS) from January 2015 to December 2015 at Dhaka Medical College hospital, Bangladesh. Then genes for ESBL and AmpC β-lactamase were detected among Qnr positive strains for better understanding the role of these genes for multiple drug resistance. Total 340 urines, sputum, wound swab and blood samples were collected from DMCH. Total 270(79.41%) Enterobacteriaceae were isolated from 340 samples. Out of 270 Enterobacteriaceae, 225(83.33%) were quinolone (ciprofloxacin) resistant strains. Qnr genes were detected in 141(62.67%) of the 225 quinolone resistant Enterobacteriaceae. Total 187 Qnr genes [84(59.57%) QnrS, 70(49.64%) QnrB and 33(23.40%) QnrA] were detected from 141 quinolone resistant strains. Total 48(34.04%) ESBL producers were detected by DDS test and 47(33.33%) ESBL producers were positive by PCR among 141 Qnr positive strains. QnrA was co-existed with CTX-M-15. QnrB was co-existed with TEM, CTXM-15 and OXA-1. QnrS genes were also associated with TEM, CTX-M-15 and OXA-1. Among 52 cefoxitin resistant Qnr positive strains, 22(42.31%) AmpC β-lactamase producers were detected by Modified three-dimensional test (MTDT) and 45(86.54%) AmpC β-lactamase producers were detected by PCR. QnrA had been identified with DHA, ACC, EBC and CIT while QnrB had been identified with DHA, ACC, EBC and CIT. QnrS had also been co-existed with DHA, ACC, EBC and CIT. The results of this study provided insights into the high proportion of Qnr genes among isolated Enterobacteriaceae. Simultaneous presence of Qnr genes and genes for extended-spectrum β-lactamase or AmpC β-lactamase were observed in multidrug resistant Enterobacteriaceae.

Combining biophysical parameters with thermal and RGB indices using machine learning models for predicting yield in yellow rust affected wheat crop

Evaluating crop health and forecasting yields in the early stages are crucial for effective crop and market management during periods of biotic stress for both farmers and policymakers. Field experiments were conducted during 2017-18 and 2018-19 with objective to evaluate the effect of yellow rust on various biophysical parameters of 24 wheat cultivars, with varying levels of resistance to yellow rust and to develop machine learning (ML) models with improved accuracy for predicting yield by integrating thermal and RGB indices with crucial plant biophysical parameters. Results revealed that as the level of rust increased, so did the canopy temperature and there was a significant decrease in crop photosynthesis, transpiration, stomatal conductance, leaf area index, membrane stability index, relative leaf water content, and normalized difference vegetation index due to rust, and the reductions were directly correlated with levels of rust severity. The yield reduction in moderate resistant, low resistant and susceptible cultivars as compared to resistant cultivars, varied from 15.9-16.9%, 28.6-34.4% and 59-61.1%, respectively. The ML models were able to provide relatively accurate early yield estimates, with the accuracy increasing as the harvest approached. The yield prediction performance of the different ML models varied with the stage of the crop growth. Based on the validation output of different ML models, Cubist, PLS, and SpikeSlab models were found to be effective in predicting the wheat yield at an early stage (55-60 days after sowing) of crop growth. The KNN, Cubist, SLR, RF, SpikeSlab, XGB, GPR and PLS models were proved to be more useful in predicting the crop yield at the middle stage (70 days after sowing) of the crop, while RF, SpikeSlab, KNN, Cubist, ELNET, GPR, SLR, XGB and MARS models were found good to predict the crop yield at late stage (80 days after sowing). The study quantified the impact of different levels of rust severity on crop biophysical parameters and demonstrated the usefulness of remote sensing and biophysical parameters data integration using machine-learning models for early yield prediction under biotically stressed conditions.

Morphological and molecular characterization of Haemonchus contortus isolated from the small ruminants of south Gujarat, India

The successful design of strategic control measures against the blood-sucking gastrointestinal nematode, Haemonchus contortus in small ruminants can be facilitated by revealing its general features from morphology to the molecular level. In the south Gujarat region of India, a total of 2408 H. contortus were collected from 84 slaughtered sheep's abomasum, consisting of 347 males and 2061 females (1:6 ratio) (p<0.05). Furthermore, 726 H. contortus were collected from 61 goats, comprising 145 males and 581 females (1:4 ratio) (p<0.05). The male worms were approximately 12±0.06 mm long, while female worms were about 20±0.09 mm long. The vulvar morphotypes of the female worms were found to be 17.7% linguiform, 76.6 % knobbed/button (p<0.05), and 5.7 % smooth type, demonstrating common features of H. contortus. The nucleotide sequences of the Internal Transcribed Spacer 1 (ITS-1) of 165 bp or ITS-2 plus of 256 bp were aligned, and it was found that the genotypes of male and female specimens of either sheep or goat origin were identical, with a 100 % match. The present isolates shared >95 % and >94 % homology with published sequences of ITS-1 and ITS-2 plus of H. contortus, respectively, with more nucleotide transitions than transversions in the aligned sequences. The reconstructed phylogram of either ITS-1 or ITS-2 plus revealed two major clades, one for H. contortus and another for other nematodes, with Haemonchus placei showing its proximity with the clade of H. contortus. The study established the role of morphological and molecular features in identifying and differentiating H. contortus parasite at the local level.

Non-linear dose response of DNA double strand breaks in response to chronic low dose radiation in individuals from high level natural radiation areas of Kerala coast

BACKGROUND

The human population living in high level natural radiation areas (HLNRAs) of Kerala coast provide unique opportunities to study the biological effects of low dose and low dose rate ionizing radiation below 100 mGy. The level of radiation in this area varies from < 1.0 to 45 mGy/year. The areas with ≤ 1.50 mGy/year are considered as normal level natural radiation areas (NLNRA) and > 1.50 mGy/year, as high level natural radiation areas (HLNRA). The present study evaluated dose response relationship between DNA double strand breaks (DSBs) and background radiation dose in individuals residing in Kerala coast. Venous blood samples were collected from 200 individuals belonging to NLNRA (n = 50) and four dose groups of HLNRA; 1.51-5.0 mGy/year (n = 50), 5.01-10.0 mGy/year (n = 30), 10.01-15.0 mGy/year (n = 33), > 15.0 mGy/year (n = 37) with written informed consent. The mean dose of NLNRA and four HLNRA dose groups studied are 1.21 ± 0.21 (range: 0.57-1.49), 3.02 ± 0.95 (range: 1.57-4.93), 7.43 ± 1.48 (range: 5.01-9.75), 12.22 ± 1.47 (range: 10.21-14.99), 21.64 ± 6.28 (range: 15.26-39.88) mGy/year, respectively. DNA DSBs were quantified using γH2AX as a marker, where foci were counted per cell using fluorescence microscopy.

RESULTS

Our results revealed that the frequency of γH2AX foci per cell was 0.090 ± 0.051 and 0.096 ± 0.051, respectively in NLNRA and HLNRA individuals, which were not significantly different (t₁₉₈ = 0.33; P = 0.739). The frequency of γH2AX foci was observed to be 0.090 ± 0.051, 0.096 ± 0.051, 0.076 ± 0.036, 0.087 ± 0.042, 0.108 ± 0.046 per cell, respectively in different dose groups of ≤ 1.50, 1.51-5.0, 5.01-10.0, 10.01-15.0, > 15.0mGy/year (ANOVA, F_4,195 = 2.18, P = 0.072) and suggested non-linearity in dose response. The frequency of γH2AX foci was observed to be 0.098 ± 0.042, 0.078 ± 0.037, 0.084 ± 0.042, 0.099 ± 0.058, 0.097 ± 0.06 and 0.114 ± 0.033 per cell in the age groups of ≤ 29, 30-34, 35-39, 40-44, 45-49 and ≥ 50 years, respectively (ANOVA, F_5,194 = 2.17, P = 0.059), which suggested marginal influence of age on the baseline of DSBs. Personal habits such as smoking (No v/s Yes: 0.092 ± 0.047 v/s 0.093 ± 0.048, t₁₉₈ = 0.13; P = 0.895) and drinking alcohol (No v/s Yes: 0.096 ± 0.052 v/s 0.091 ± 0.045, t₁₉₈ = 0.62; P = 0.538) did not show any influence on DSBs in the population.

CONCLUSION

The present study did not show any increase in DSBs in different dose groups of HLNRA compared to NLNRA, however, it suggested a non-linear dose response between DNA DSBs and chronic low dose radiation.

Evaluation of natural chronic low dose radiation exposure on telomere length and transcriptional response of shelterin complex in individuals residing in Kerala coast, India

The high level natural radiation areas (HLNRA) of Kerala coast provide unique opportunity to study the biological effect of chronic low dose ionizing radiation (LDIR) on human population below 100 mSv. The radiation level in this area varies from < 1.0-45 mGy /year due to patchy distribution of monazite in the sand, which contains ²³²Th (8-10%), ²³⁸U (0.3%), and their decay products. Telomere length attrition has been correlated to DNA damage due to genotoxic agents. The objective of the present study is to evaluate the effect of natural chronic LDIR exposure on telomere length and transcriptional response of telomere specific and DNA damage repair genes in peripheral blood mononuclear cells (PBMCs) of individuals from normal level natural radiation areas (NLNRA) and HLNRA of Kerala coast, southwest India. Blood samples were collected from 71 random male donors (24-80 years) from NLNRA (≤1.50 mGy/year; N = 19) and two HLNRA dose groups [1.51-10 mGy/year (N = 17); > 10 mGy/year, (N = 35)]. Genomic DNA was isolated from PBMCs and relative telomere length (RTL) was determined using real time q-PCR. Radio-adaptive response (RAR) study was carried out in PBMCs of 40 random males from NLNRA (N = 20) and HLNRA (>10 mGy/year; N = 20), where PBMCs were given a challenged dose of 2.0 Gy gamma radiation at 4 h. Transcriptional profile of telomere specific (TRF1, TRF2, POT1, TIN2, TPP1, RAP1), DNA damage response (RAD17, ATM, CHEK1) and base excision repair pathway (BER) (OGG1, XRCC1, NTH1, NEIL1, MUTYH, MBD4) genes were analysed at basal level and after a challenge dose of 2.0 Gy at 4 h. Our results did not show any significant effect of chronic LDR on RTL among the individuals from NLNRA and two HLNRA groups (p = 0.195). However, influence of age on RTL was clearly evident among NLNRA and HLNRA individuals. At basal level, TRF1, TRF2, TIN2, MBD4, NEIL1 and RAD17 showed significant up-regulation, whereas XRCC1 was significantly down regulated in HLNRA individuals. After a challenge dose of 2.0 Gy, significant transcriptional up-regulation was observed at telomere specific (TRF2, POT1) and BER (MBD4, NEIL1) genes in HLNRA individuals as compared to NLNRA suggesting their role in RAR. In conclusion, elevated level of natural chronic LDR exposure did not have any adverse effect on telomere length in Kerala coast. Significant transcriptional response at TRF2, MBD4 and NEIL1 at basal level and with a challenge dose of 2.0 Gy suggested their active involvement in efficient repair and telomere maintenance in individuals from HLNRA of Kerala coast.

Factors Affecting School Performance in the Adolescents of USA- Youth Risk Behavior Surveillance System

Introduction

Poor academic performance has been linked to factors such as sleep, health, illicit drug use, physical fighting, social media use, cyber bullying, physical activity, homelessness, times spent in video games and television. It is difficult to get a sense of the interplay between and relative importance of different behaviours/factors on academic performance as only limited research has been aimed at quantifying these factors.

Objectives

To evaluate association of school performance and variables in five categories of the YRBSS: physical fighting, diet/lifestyle, electronic device usage, concurrent substance use, and violence/self-harm.

Methods

The CDC Youth Risk Behavior Surveillance System (YRBSS) data from 1991-2019 was used in study. Respondents were grouped by good and poor school performance and variables related to nutrition/lifestyle, electronic device use, concurrent substance use, mood/violence/self-harm were analyzed using chi-square test.

Results

A total of 41,235 student respondents.Nutrition/Lifestyle, electronic device use, concurrent substance use, mood/violence/self-harm are found to be significantly correlated with school performance.

	Poor Performance n(%)	Good Performance n(%)	Total n(%)	p-Value
Nutrition/Lifestyle
Daily breakfast	2,715(26)	11,429(38.22)	14,144(35.06)	<0.0001
Sodas ≥2/day	1,998(19.12)	2,710(9.03)	4,708(11.63)	<0.0001
Concurrent Substance Use
Alcohol use	3,544(37.55)	8,067(28.49)	11,611(30.75)	<0.0001
Cigarette smoking	1,616(15.74)	1,845(6.17)	3,461(8.61)	<0.0001
Mood/Violence/Self-Harm
Difficulty concentrating	4,188(46.34)	7,327(28.27)	11,516(32.94)	<0.0001
Felt sad or hopeless	4,373(41.06)	9,038(29.67)	13,410(32.62)	<0.0001
Considered suicide	2,567(24.14)	4,810(15.8)	7,377(17.96)	<0.0001

Conclusions

In national data, we found school performance is affected by nutrition, lifestyle, substance use, mood and exposure to surrounding violence, and self-harm. Further studies should be planned to evaluate benefits from the risk stratification to reduce this burden amongst US adolescents.

Disclosure

No significant relationships.

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Evaluation of risk due to chronic low dose ionizing radiation exposure on the birth prevalence of congenital heart diseases (CHD) among the newborns from high-level natural radiation areas of Kerala coast, India

Background

The human population residing in monazite bearing Kerala coast are exposed to chronic low dose and low dose rate external gamma radiation due to Th232 deposits in its beach sand. The radiation level in this area varies from < 1.0 to 45.0 mGy/year. This area serves as an ideal source for conducting large-scale epidemiological studies for assessing risk of low dose and low dose rate radiation exposure on human population. The areas with a dose level of ≤1.50 mGy/year are considered as normal level natural radiation areas (NLNRAs) and areas with > 1.50 mGy/year, as high level natural radiation areas (HLNRAs). HLNRAs were further stratified into three dose groups of 1.51-3.0 mGy/year, 3.01-6.00 mGy/year and > 6.0 mGy/year. The present study evaluates the effects of chronic low dose radiation (LDR) exposure on the birth prevalence of Congenital Heart Diseases (CHD) among the live newborns monitored in hospital based prospective study from NLNRAs and HLNRAs of Kerala coast, India.

Methodology

Consecutive newborns were monitored from two hospital units located in the study area for congenital malformations. Referred CHD cases among the newborns screened were confirmed by conducting investigations such as pulse oximetry, chest X-ray, electrocardiogram and echocardiogram etc.

Results

Among the newborns screened, 289 CHDs were identified with a frequency of 1.49‰ among 193,634 livebirths, which constituted 6.03% of overall malformations and 16.29% of major malformations. Multiple logistic regression analysis suggested that the risk of CHD among the newborns of mothers from HLNRAs with a dose group of 1.51-3.0 mGy/year was significantly lower as compared to NLNRA (OR = 0.72, 95% CI: 0.57-0.92), whereas it was similar in HLNRA dose groups of 3.01-6.00 mGy/year (OR = 0.55, 95% CI: 0.31-1.00) and ≥ 6.0 mGy/year (OR = 0.96, 95% CI: 0.50-1.85). The frequency of CHDs did not show any radiation dose related increasing trend. However, a significant (P = 0.005) reduction was observed in the birth prevalence of CHDs among the newborns from HLNRA (1.28‰) as compared to NLNRA (1.79‰).

Conclusion

Chronic LDR exposure did not show any increased risk on the birth prevalence of CHDs from high-level natural radiation areas of Kerala coast, India. No linear increasing trend was observed with respect to different background dose groups. The frequency of CHD was observed to be 1.49 per 1000 livebirths, which was similar to the frequency of severe CHD rate reported elsewhere in India and was much less than the reported frequency of 9 per thousand.

Enhanced superconductivity and ferroelectric quantum criticality in plastically deformed strontium titanate

The properties of quantum materials are commonly tuned using experimental variables such as pressure, magnetic field and doping. Here we explore a different approach using irreversible, plastic deformation of single crystals. We show that compressive plastic deformation induces low-dimensional superconductivity well above the superconducting transition temperature (T_c) of undeformed SrTiO₃, with evidence of possible superconducting correlations at temperatures two orders of magnitude above the bulk T_c. The enhanced superconductivity is correlated with the appearance of self-organized dislocation structures, as revealed by diffuse neutron and X-ray scattering. We also observe deformation-induced signatures of quantum-critical ferroelectric fluctuations and inhomogeneous ferroelectric order using Raman scattering. Our results suggest that strain surrounding the self-organized dislocation structures induces local ferroelectricity and quantum-critical dynamics that strongly influence T_c, consistent with a theory of superconductivity enhanced by soft polar fluctuations. Our results demonstrate the potential of plastic deformation and dislocation engineering for the manipulation of electronic properties of quantum materials.

Global DNA methylation profile at LINE-1 repeats and promoter methylation of genes involved in DNA damage response and repair pathways in human peripheral blood mononuclear cells in response to γ-radiation

DNA methylation is an epigenetic mechanism, which plays an important role in gene regulation. The present study evaluated DNA methylation profile of LINE1 repeats and promoter methylation of DNA damage response (DDR) and DNA repair (DR) genes (PARP1, ATM, BRCA1, MLH1, XPC, RAD23B, APC, TNFα, DNMT3A, MRE11A, MGMT, CDKN2A, MTHFR) in human peripheral blood mononuclear cells (PBMCs) of healthy donors in response to γ-radiation. Methylation level was correlated with gene expression profile of selected DDR and DR genes (APC, MLH1, PARP1, MRE11A, TNFα, MGMT) to understand their role in gene regulation. Blood samples were collected from 15 random healthy donors, PBMCs were isolated, exposed to 0.1 Gy (low) and 2.0 Gy (high) doses of γ-radiation and proliferated for 48 h and 72 h. Genomic DNA and total RNA were isolated from irradiated PBMCs along with un-irradiated control. Methylation profile was determined from bisulphite converted DNA and amplified by methylation sensitive high resolution melting (MS-HRM) method. Total RNA was converted to cDNA and relative expression was analysed using real time quantitative-PCR. Our results revealed that at 0.1 Gy, MRE11A and TNFα showed significant (P < 0.05) increase in methylation at 72 h. At 2.0 Gy, significant increase (P < 0.05) in methylation profile was observed at LINE1, MRE11A, PARP1, BRCA1, DNMT3A and RAD23B at 48 h and 72 h. PARP1 showed significant positive correlation of methylation status with gene expression. In conclusion, low and high doses of γ-radiation have significant influence on DNA methylation status of LINE1, DDR and DR genes suggesting their potential role as epigenetic signatures in human PBMCs, which can be further explored in human populations.

Practice variation in the diagnosis of acute rejection among pediatric heart transplant centers: An analysis of the pediatric heart transplant society (PHTS) registry

BACKGROUND

Freedom from rejection in pediatric heart transplant recipients is highly variable across centers. This study aimed to assess the center variation in methods used to diagnose rejection in the first-year post-transplant and determine the impact of this variation on patient outcomes.

METHODS

The PHTS registry was queried for all rejection episodes in the first-year post-transplant (2010-2019). The primary method for rejection diagnosis was determined for each event as surveillance biopsy, echo diagnosis, or clinical. The percentage of first-year rejection events diagnosed by surveillance biopsy was used to approximate the surveillance strategy across centers. Methods of rejection diagnosis were described and patient outcomes were assessed based on surveillance biopsy utilization among centers.

RESULTS

A total of 3985 patients from 56 centers were included. Of this group, 873 (22%) developed rejection within the first-year post-transplant. Surveillance biopsy was the most common method of rejection diagnosis (71.7%), but practices were highly variable across centers. The majority (73.6%) of first rejection events occurred within 3-months of transplantation. Diagnosis modality in the first-year was not independently associated with freedom from rejection, freedom from rejection with hemodynamic compromise, or overall graft survival.

CONCLUSIONS

Rejection in the first-year after pediatric heart transplant occurs in 22% of patients and most commonly in the first 3 months post-transplant. Significant variation exists across centers in the methods used to diagnose rejection in pediatric heart transplant recipients, however, these variable strategies are not independently associated with freedom from rejection, rejection with hemodynamic compromise, or overall graft survival.

A critical review of biogas production and usage with legislations framework across the globe

This review showcases a comprehensive analysis of studies that highlight the different conversion procedures attempted across the globe. The resources of biogas production along with treatment methods are presented. The effect of different governing parameters like feedstock types, pretreatment approaches, process development, and yield to enhance the biogas productivity is highlighted. Biogas applications, for example, in heating, electricity production, and transportation with their global share based on national and international statistics are emphasized. Reviewing the world research progress in the past 10 years shows an increase of ~ 90% in biogas industry (120 GW in 2019 compared to 65 GW in 2010). Europe (e.g., in 2017) contributed to over 70% of the world biogas generation representing 64 TWh. Finally, different regulations that manage the biogas market are presented. Management of biogas market includes the processes of exploration, production, treatment, and environmental impact assessment, till the marketing and safe disposal of wastes associated with biogas handling. A brief overview of some safety rules and proposed policy based on the world regulations is provided. The effect of these regulations and policies on marketing and promoting biogas is highlighted for different countries. The results from such studies show that Europe has the highest promotion rate, while nowadays in China and India the consumption rate is maximum as a result of applying up-to-date policies and procedures.

Radio-adaptive response and correlation of non-homologous end joining repair gene polymorphisms [XRRC5 (3R/2R/1R/0R), XRCC6(C/G) and XRCC7 (G/T)] in human peripheral blood mononuclear cells exposed to gamma radiation

BACKGROUND

Radio-adaptive response (RAR) is transient phenomena, where cells conditioned with a small dose (priming) of ionizing radiation shows significantly reduced DNA damage with a subsequent high challenging dose. The role of DNA double strand break repair gene polymorphism in RAR is not known. In the present study attempt was made to find out the influence of NHEJ repair gene polymorphisms [a VNTR; XRCC5 (3R/2R/1R/0R); two single nucleotide polymorphisms (SNPs); XRCC6 (C/G) and XRCC7 (G/T)] with DNA damage, repair and mRNA expression in human PBMCs in dose and adaptive response studies. Genomic DNA extracted from venous blood samples of 20 random healthy donors (16 adaptive and 4 non-adaptive) and genotyping of NHEJ repair genes was carried out using PCR amplified length polymorphism.

RESULTS

The dose response study revealed significant positive correlation of genotypes at XRRC5 (3R/2R/1R/0R), XRCC6(C/G) and XRCC7 (G/T) with DNA damage. Donors having genotypes with 2R allele at XRCC5 showed significant positive correlation with mRNA expression level (0R/2R: r = 0.846, P = 0.034; 1R/2R: r = 0.698, P = 0.0001 and 2R/2R: r = 0.831, P = 0.0001) for dose response. Genotypes C/C and C/G of XRCC6 showed a significant positive correlation (P = 0.0001), whereas, genotype T/T of XRCC7 showed significant negative correlation (r = - 0.376, P = 0.041) with mRNA expression.

CONCLUSION

Interestingly, adaptive donors having C/G genotype of XRCC6 showed significantly higher (P < 0.05) mRNA expression level in primed cells suggesting their role in RAR. In addition, NHEJ repair gene polymorphisms play crucial role with radio-sensitivity and RAR in human PBMCs.

Activation of TRPV4 by mechanical, osmotic or pharmaceutical stimulation is anti-inflammatory blocking IL-1β mediated articular cartilage matrix destruction

OBJECTIVE

Cartilage health is maintained in response to a range of mechanical stimuli including compressive, shear and tensile strains and associated alterations in osmolality. The osmotic-sensitive ion channel Transient Receptor Potential Vanilloid 4 (TRPV4) is required for mechanotransduction. Mechanical stimuli inhibit interleukin-1β (IL-1β) mediated inflammatory signalling, however the mechanism is unclear. This study aims to clarify the role of TRPV4 in this response.

DESIGN

TRPV4 activity was modulated glycogen synthase kinase (GSK205 antagonist or GSK1016790 A (GSK101) agonist) in articular chondrocytes and cartilage explants in the presence or absence of IL-1β, mechanical (10% cyclic tensile strain (CTS), 0.33 Hz, 24hrs) or osmotic loading (200mOsm, 24hrs). Nitric oxide (NO), prostaglandin E₂ (PGE₂) and sulphated glycosaminoglycan (sGAG) release and cartilage biomechanics were analysed. Alterations in post-translational tubulin modifications and primary cilia length regulation were examined.

RESULTS

In isolated chondrocytes, mechanical loading inhibited IL-1β mediated NO and PGE₂ release. This response was inhibited by GSK205. Similarly, osmotic loading was anti-inflammatory in cells and explants, this response was abrogated by TRPV4 inhibition. In explants, GSK101 inhibited IL-1β mediated NO release and prevented cartilage degradation and loss of mechanical properties. Upon activation, TRPV4 cilia localisation was increased resulting in histone deacetylase 6 (HDAC6)-dependent modulation of soluble tubulin and altered cilia length regulation.

CONCLUSION

Mechanical, osmotic or pharmaceutical activation of TRPV4 regulates HDAC6-dependent modulation of ciliary tubulin and is anti-inflammatory. This study reveals for the first time, the potential of TRPV4 manipulation as a novel therapeutic mechanism to supress pro-inflammatory signalling and cartilage degradation.

COMPARATIVE ANALYSIS OF CARBOXYMETHYL CELLULOSE AND PARTIALLY HYDROLYZED POLYACRYLAMIDE – LOW-SOLID NONDISPERSED DRILLING MUD WITH RESPECT TO PROPER-TY ENHANCEMENT AND SHALE INHIBITION

During drilling, different problems are encountered that can interfere with smooth drilling processes, including the accumulation of cuttings, reduced penetration rates, pipe sticking, loss of wellbore stability, and loss of circulation. These problems are generally encountered with conventional drilling mud, such as the bentonite–barite mud system. Formation damage is the most common problem encountered in bentonite mud systems with high solid content. In this work, we aimed to formulate two low-solid nondispersed (LSND) muds: carboxymethyl cellulose (CMC)–LSND mud and partially hydrolyzed polyacrylamide (PHPA)–LSND mud. A comparative analysis was performed to evaluate their property enhancements. LSND muds aid in maintaining hole stability and proper cutting removal. The results of this work show that the addition of both CMC and PHPA helps to improve drilling fluid properties; however, the PHPA–LSND mud was found to be superior. Shale swelling is a major concern in the petroleum industry, as it causes various other problems, such as pipe sticking, low penetration rates, and bit wear. The effect of these two LSND polymer muds in inhibiting shale swelling was analyzed using shale collected from the Champhai district of Mizoram, India.

Radio-adaptive response, individual radio-sensitivity and correlation of base excision repair gene polymorphism (hOGG1, APE1, XRCC1, and LIGASE1) in human peripheral blood mononuclear cells exposed to gamma radiation

Radio-adaptive response (RAR) is a biological mechanism, where cells primed with a low dose exhibit reduced DNA damage with a high challenging dose. Single nucleotide polymorphisms (SNPs) of DNA repair genes including base excision repair (BER) pathway are known to be associated with radio-sensitivity but involvement in RAR is not yet understood. In the present study, attempt was made to correlate genotype frequencies of four BER SNPs [hOGG1(Ser326Cys), XRCC1(Arg399Gln), APE1(Asp148Glu) and LIGASE1(A/C)] with DNA damage, repair and mRNA expression level among 20 healthy donors (12 adaptive and 8 nonadaptive). Our results revealed that LIGASE1 (p = .002) showed significant correlation with DNA damage and mRNA expression level with increasing dose. hOGG1 (Ser326Cys), XRCC1 (Arg399Gln) and LIGASE1(A/C) polymorphisms showed significant difference with DNA damage (%T) and mRNA expression profile in primed cells among adaptive donors. In conclusion, BER gene polymorphisms play important role in identifying donors with radio-sensitivity and RAR in human cells.

Evaluation of the influence of chronic low-dose radiation on DNA repair gene polymorphisms [XRCC1, XRCC3, PRKDC (XRCC7), LIG1, NEIL1] in individuals from normal and high level natural radiation areas of Kerala Coast

Background: Single Nucleotide Polymorphisms (SNPs) at DNA repair genes are considered as potential biomarkers of radio-sensitivity. The coastal belt of Kerala in south west India has a patchy distribution of monazite in its beach sand that contains Th-232 and its decay products. Thus, radiation levels in this area vary from <1.0mGy to 45.0mGy/year. The areas with external gamma radiation dose >1.5mGy/year are considered as High-Level Natural Radiation Areas (HLNRA) and ≤ 1.5mGy/year are Normal Level Natural Radiation Area (NLNRA).Objective: In the present study, an attempt was made to evaluate the influence of chronic low dose radiation exposure on DNA repair gene polymorphisms in NLNRA and HLNRA population of Kerala coast.Materials and methods: Genomic DNA was isolated from venous blood samples of 246 random, healthy individuals (NLNRA, N = 104; HLNRA, N = 142) and genotyping of five SNPs such as X-ray repair cross complementing 1(XRCC1 Arg399Gln), X-ray repair cross complementing 3 (XRCC3 Thr241Met], Protein kinase, DNA-activated, catalytic subunit (PRKDC) (X-ray repair cross-complementing group 7, XRCC7 G/T), nei like DNA glycosylase 1 (NEIL1 G/T) and DNA ligase 1 (LIG1 A/C) was carried out using PCR based restriction fragment length polymorphism (PCR-RFLP) followed by silver staining.Results: Our results showed no significant difference in genotype frequencies in HLNRA vs NLNRA at three of the five SNPs studied i.e. XRCC1 Arg399Gln (χ²₍₂₎ = 5.85, p = .054), XRCC3 Thr241Met (χ²₍₁₎ = 0.71, p = .339), PRKDC (XRCC7 G/T) (χ²₍₂₎ = 3.72, p = .156), whereas significant difference was observed at NEIL1 G/T (χ²₍₂₎ =8.71, p = .013) and LIG1 A/C (χ²₍₂₎ = 7.66, p = .022). The odds of heterozygote to homozygote genotypes in HLNRA relative to NLNRA at XRCC1 Arg399Gln (OR = 1.96, 95% CI: 1.13-3.40), XRCC3 Thr241Met (OR = 0.73, 95% CI: 0.41-1.31), PRKDC (XRCC7 G/T), (OR = 0.81; 95% CI: 0.48-1.38), NEIL1 G/T (OR = 0.54; 95% CI: 0.31-0.96) and LIG1 A/C (OR = 1.62; 95% CI: 0.97-2.69) was also not significantly different in HLNRA vs NLNRA, except at XRCC1 and NEIL1.Conclusion: The genotype frequencies at three of these SNPs i.e. XRCC1 Arg399Gln, XRCC3 Thr241Met and PRKDC (XRCC7 G/T) were similar, whereas NEIL1 G/T and LIG1 A/C showed significant difference between HLNRA and NLNRA population. However, further research using more number of SNPs in a larger cohort is required in this study area.

Premature chromosome condensation assay to study influence of high-level natural radiation on the initial DNA double strand break repair in human G0 lymphocytes

The inherent capacity of individuals to efficiently repair ionizing radiation induced DNA double strand breaks (DSBs) may be inherited, however, it is influenced by several epigenetic and environmental factors. A pilot study tested whether chronic low dose natural radiation exposure influences the rejoining of initial DNA DSBs induced by a 2 Gy γ-irradiation in 22 individuals from high (>1.5 mGy/year) and normal (≤1.5 mGy/year) level natural radiation areas (H&NLNRA) of Kerala. Rejoining of DSBs (during 1 h at 37 °C, immediately after irradiation) was evaluated at the chromosome level in the presence and absence of wortmannin (a potent inhibitor of DSB repair in normal human cells) using a cell fusion-induced premature chromosome condensation (PCC) assay. The PCC assay quantitates DSBs in the form of excess chromosome fragments in human G₀ lymphocytes without the requirement for cell division. A quantitative difference was observed in the early rejoining of DNA DSBs between individuals from HLNRA and NLNRA, with HLNRA individuals showing a higher (P = 0.05) mean initial repair ratio. The results indicate an influence of chronic low dose natural radiation on initial DNA DSB repair in inhabitants of HLNRA of the Kerala coast.

1D-2D hybrids as efficient optoelectronic materials: a study on graphitic carbon nitride nanosheets wrapped with zinc oxide rods

Zinc oxide (ZnO) nanorods (NRs) wrapped with graphitic carbon nitride (GCN) nanosheet (NS) hybrids have been synthesized by a simple chemical process. The as-prepared samples are characterized by X-ray diffraction, field emission scanning electron microscopy, high resolution transmission electron microscopy, Fourier transformed infrared spectroscopy, UV-Vis spectroscopy and photoluminescence spectroscopy. The images obtained from the transmission electron microscopic study and the existence of C-N stretching modes as observed from Fourier transform infrared spectroscopy confirm the successful attachment of GCN NSs onto the ZnO NRs. It is seen that hybrid samples show broad photoluminescence (PL) emission with enhanced defect related emission along with a quenching effect due to the charge transfer mechanism. The results have been explained by taking into consideration the three different types of electron transitions occurring within the type-II band structure of the hybrid samples. Moreover a study on the conductivity of the samples is carried out under dark conditions and also under ultraviolet (UV) light irradiation. It is observed that the hybrid samples show significantly improved conductivity under both dark and UV irradiated conditions. The absorbance of the samples in the UV range shows better conductivity under UV conditions as compared to dark conditions.

Frequency of chromosome aberrations among adult male individuals from high and normal level natural radiation areas of Kerala in the southwest coast of India

Chromosome aberration analysis was carried out in peripheral blood lymphocytes of adult male individuals from normal level natural radiation areas (NLNRA, ≤1.5 mGy/year, N = 27) and high level natural radiation areas (HLNRA, >1.5mGy/year, N = 70) of Kerala coast in southwest India. The mean age of individuals from NLNRA and HLNRA was 40.9 ± 9.4 and 43.7 ± 12.4 years, respectively, with an overall mean of 42.9 ± 11.6 (range: 18-80). Whole-blood cultures were set up and about 260 metaphases were scored per individual. The frequency of chromosome aberrations was calculated per 1000 cells. The overall basal frequency of unstable (dicentrics and rings), stable (translocations and inversions) and other (fragments and breaks) aberrations was 1.54 ± 0.25, 4.1 ± 0.40 and 6.66 ± 0.51, respectively. Individuals of NLNRA and HLNRA had statistically similar frequency of unstable (2.11 ± 0.64 v/s 1.39 ± 0.26; RR = 0.66; 95% CI: 0.33-1.33), stable (4.60 ± 0.94 v/s 3.97 ± 0.44; RR = 0.86; 95% CI: 0.55-1.36) and other (7.85 ± 1.23 v/s 6.36 ± 0.56; RR = 0.81; 95% CI: 0.57-1.15) chromosome aberrations. Frequencies of unstable, stable and other chromosome aberrations did not show any dose response after stratification of HLNRA samples into three dose groups (1.51-5.0 mGy/year, 5.01-10 mGy/year and >10.0 mGy/year). Smokers showed an increase in other chromosome aberrations (P < 0.001), but smoking was not associated with unstable and stable aberrations. Alcohol consumption and tobacco chewing had no significant association with any type of chromosome aberrations. In conclusion, chronic low dose radiation prevailing in Kerala coast did not show any significant effect on the basal frequency of chromosome aberrations among the adult population.

Foot-and-mouth disease virus transmission dynamics and persistence in a herd of vaccinated dairy cattle in India

Foot-and-mouth disease (FMD) is an important transboundary disease with substantial economic impacts. Although between-herd transmission of the disease has been well studied, studies focusing on within-herd transmission using farm-level outbreak data are rare. The aim of this study was to estimate parameters associated with within-herd transmission, host physiological factors and FMD virus (FMDV) persistence using data collected from an outbreak that occurred at a large, organized dairy farm in India. Of 1,836 regularly vaccinated, adult dairy cattle, 222 had clinical signs of FMD over a 39-day period. Assuming homogenous mixing, a frequency-dependent compartmental model of disease transmission was built. The transmission coefficient and basic reproductive number were estimated to be between 16.2-18.4 and 67-88, respectively. Non-pregnant animals were more likely to manifest clinical signs of FMD as compared to pregnant cattle. Based on oropharyngeal fluid (probang) sampling and FMDV-specific RT-PCR, four of 36 longitudinally sampled animals (14%) were persistently infected carriers 10.5 months post-outbreak. There was no statistical difference between subclinical and clinically infected animals in the duration of the carrier state. However, prevalence of NSP-ELISA antibodies differed significantly between subclinical and clinically infected animals 12 months after the outbreak with 83% seroprevalence amongst clinically infected cattle compared to 69% of subclinical animals. This study further elucidates within-herd FMD transmission dynamics during the acute-phase and characterizes duration of FMDV persistence and seroprevalence of FMD under natural conditions in an endemic setting.

Global transcriptome profile reveals abundance of DNA damage response and repair genes in individuals from high level natural radiation areas of Kerala coast

The high level natural radiation areas (HLNRA) of Kerala coast in south west India is unique for its wide variation in the background radiation dose (<1.0mGy to 45mGy/year) and vast population size. Several biological studies conducted in this area did not reveal any adverse effects of chronic low dose and low dose rate radiation on human population. In the present study, global transcriptome analysis was carried out in peripheral blood mono-nuclear cells of 36 individuals belonging to different background dose groups [NLNRA, (Group I, ≤1.50 mGy/year) and three groups of HLNRA; Group II, 1.51–5.0 mGy/year), Group III, 5.01-15mGy/year and Group IV, >15.0 mGy/year] to find out differentially expressed genes and their biological significance in response to chronic low dose radiation exposure. Our results revealed a dose dependent increase in the number of differentially expressed genes with respect to different background dose levels. Gene ontology analysis revealed majority of these differentially expressed genes are involved in DNA damage response (DDR) signaling, DNA repair, cell cycle arrest, apoptosis, histone/chromatin modification and immune response. In the present study, 64 background dose responsive genes have been identified as possible chronic low dose radiation signatures. Validation of 30 differentially expressed genes was carried out using fluorescent based universal probe library. Abundance of DDR and DNA repair genes along with pathways such as MAPK, p53 and JNK in higher background dose groups (> 5.0mGy/year) indicated a possible threshold dose for DDR signaling and are plausible reason of observing in vivo radio-adaptive response and non-carcinogenesis in HLNRA population. To our knowledge, this is the first study on molecular effect of chronic low dose radiation exposure on human population from high background radiation areas at transcriptome level using high throughput approach. These findings have tremendous implications in understanding low dose radiation biology especially, the effect of low dose radiation exposure in humans.

Radio-adaptive response in peripheral blood lymphocytes of individuals residing in high-level natural radiation areas of Kerala in the southwest coast of India

The present study investigates whether the chronic low-dose radiation exposure induces an in vivo radio-adaptive response in individuals from high-level natural radiation areas (HLNRA) of the Kerala coast. Peripheral blood samples from 54 adult male individuals aged between 26 and 65 years were collected for the study with written informed consent. Each of the whole blood sample was divided into three, one was sham irradiated, second and third was exposed to challenging doses of 1.0 and 2.0 Gy gamma radiation, respectively. Cytokinesis-block micronucleus (CBMN) assay was employed to study the radio-adaptive response. Seventeen individuals were from normal-level natural radiation area (NLNRA ≤1.5 mGy/year) and 37 from HLNRA (> 1.5 mGy/year). Based on the annual dose received, individuals from HLNRA were further classified into low-dose group (LDG, 1.51-5.0 mGy/year, N = 19) and high-dose group (HDG >5.0 mGy/year, N = 18). Basal frequency of micronucleus (MN) was comparable across the three dose groups (NLNRA, LDG and HDG, P = 0.64). Age of the individuals showed a significant effect on the frequency of MN after challenging dose exposures. The mean frequency of MN was significantly lower in elder (>40 years) individuals from HDG of HLNRA as compared to the young (≤40 years) individuals after 1.0 Gy (P < 0.001) and 2.0 Gy (P = 0.002) of challenging doses. However, young and elder individuals within NLNRA and LDG of HLNRA showed similar frequency of MN after the challenging dose exposures. Thus, increased level of chronic low-dose radiation (>5.0 mGy/year) seems to act as a priming dose resulting in the induction of an in vivo radio-adaptive response in elder individuals of the Kerala coast.

Family-led rehabilitation after stroke in India (ATTEND): a randomised controlled trial

BACKGROUND

Most people with stroke in India have no access to organised rehabilitation services. The effectiveness of training family members to provide stroke rehabilitation is uncertain. Our primary objective was to determine whether family-led stroke rehabilitation, initiated in hospital and continued at home, would be superior to usual care in a low-resource setting.

METHODS

The Family-led Rehabilitation after Stroke in India (ATTEND) trial was a prospectively randomised open trial with blinded endpoint done across 14 hospitals in India. Patients aged 18 years or older who had had a stroke within the past month, had residual disability and reasonable expectation of survival, and who had an informal family-nominated caregiver were randomly assigned to intervention or usual care by site coordinators using a secure web-based system with minimisation by site and stroke severity. The family members of participants in the intervention group received additional structured rehabilitation training-including information provision, joint goal setting, carer training, and task-specific training-that was started in hospital and continued at home for up to 2 months. The primary outcome was death or dependency at 6 months, defined by scores 3-6 on the modified Rankin scale (range, 0 [no symptoms] to 6 [death]) as assessed by masked observers. Analyses were by intention to treat. This trial is registered with Clinical Trials Registry-India (CTRI/2013/04/003557), Australian New Zealand Clinical Trials Registry (ACTRN12613000078752), and Universal Trial Number (U1111-1138-6707).

FINDINGS

Between Jan 13, 2014, and Feb 12, 2016, 1250 patients were randomly assigned to intervention (n=623) or control (n=627) groups. 33 patients were lost to follow-up (14 intervention, 19 control) and five patients withdrew (two intervention, three control). At 6 months, 285 (47%) of 607 patients in the intervention group and 287 (47%) of 605 controls were dead or dependent (odds ratio 0·98, 95% CI 0·78-1·23, p=0·87). 72 (12%) patients in the intervention group and 86 (14%) in the control group died (p=0·27), and we observed no difference in rehospitalisation (89 [14%]patients in the intervention group vs 82 [13%] in the control group; p=0·56). We also found no difference in total non-fatal events (112 events in 82 [13%] intervention patients vs 110 events in 79 [13%] control patients; p=0·80).

INTERPRETATION

Although task shifting is an attractive solution for health-care sustainability, our results do not support investment in new stroke rehabilitation services that shift tasks to family caregivers, unless new evidence emerges. A future avenue of research should be to investigate the effects of task shifting to health-care assistants or team-based community care.

FUNDING

The National Health and Medical Research Council of Australia.

Quantitative characteristics of the foot-and-mouth disease carrier state under natural conditions in India

The goal of this study was to characterize the properties and duration of the foot-and-mouth disease (FMD) carrier state and associated serological responses subsequent to vaccination and naturally occurring infection at two farms in northern India. Despite previous vaccination of cattle in these herds, clinical signs of FMD occurred in October 2013 within a subset of animals at the farms containing juvenile-yearling heifers and steers (Farm A) and adult dairy cattle (Farm B). Subsequent to the outbreak, FMD virus (FMDV) asymptomatic carriers were identified in both herds by seroreactivity to FMDV non-structural proteins and detection of FMDV genomic RNA in oropharyngeal fluid. Carriers' seroreactivity and FMDV genome detection status were subsequently monitored monthly for 23 months. The mean extinction time of the carrier state was 13.1 ± 0.2 months, with extinction having occurred significantly faster amongst adult dairy cattle at Farm B compared to younger animals at Farm A. The rate of decrease in the proportion of carrier animals was calculated to be 0.07 per month. Seroprevalence against FMDV non-structural proteins decreased over the course of the study period, but was found to increase transiently following repeated vaccinations. These data provide novel insights into viral and host factors associated with the FMDV carrier state under natural conditions. The findings reported herein may be relevant to field veterinarians and governmental regulatory entities engaged in FMD response and control measures.

An Assessment of the Primary Payer Variable among Breast and Colorectal Cancer Cases in the Massachusetts Cancer Registry, 2005-2009

The Massachusetts Cancer Registry (MCR) reviewed the medical charts of 5,348 randomly selected breast and colorectal cancer cases diagnosed from 2005 to 2009. The purpose of this study was to assess the reliability of primary payer at diagnosis in the MCR database and to examine primary payer and the first course of treatment of individual cancer patients. For the first period (2005-2006), private insurance (72.6% agreement) and Medicare (84.3% agreement) indicated strong agreement with kappa values of 0.62 and 0.72, respectively. Agreement for the later period was again stronger in the private insurance and Medicare categories (kappa= 0.63 and 0.74, respectively).

Fibroblast growth factor-23 levels in maintenance hemodialysis patients in India

Fibroblast growth factor-23 (FGF-23) levels start rising early in patients with chronic kidney disease and is implicated in cardiovascular and overall mortality of hemodialysis patients. We conducted a prospective observational cohort study in stable dialysis patients looking into the levels of FGF-23 in hemodialysis patients and its association with various demographic and biochemical variables and mortality. A total of 91 patients were enrolled in the study. The mean FGF-23 levels were very high (1152.7 pg/ml). FGF-23 levels were significantly associated with serum phosphorus and parathyroid hormone (PTH) levels in univariate and multivariate analysis. No significant association between FGF-23 and cardiovascular comorbidities and overall mortality was seen. FGF-23 levels rise exponentially in maintenance hemodialysis patients. There is a strong association between FGF-23 and phosphorus and PTH levels. No association between FGF-23 and mortality was noted in our patients.

What a difference a day makes: same-day vs. 2-day sputum smear microscopy for diagnosing tuberculosis

Setting: Nine district-level microscopy centres in Assam and Tripura, India. Objective: Same-day sputum microscopy is now recommended for tuberculosis (TB) diagnosis. We compared this method against the conventional 2-day approach in routine programmatic settings. Methods: During October-December 2012, all adult presumptive TB patients were requested to provide three sputum samples (one at the initial visit, the second 1 h after the first sample, and the third the next morning) for examination by Ziehl-Neelsen smear microscopy. Detection of acid-fast bacilli with any sample was diagnostic. The first and second spot sample comprised the same-day approach, and the first spot sample and next-day sample comprised the 2-day approach. Results: Of 2168 presumptive TB patients, 403 (18.6%) were smear-positive according to the same-day method compared to 427 (19.7%) by the 2-day method (McNemar's test, P < 0.001). Of the total 429 TB patients, 26 (6.1%) were missed by the same-day method and 2 (0.5%) by the 2-day method. Conclusion: Same-day specimen collection for microscopy missed more TB than 2-day collection. In India, missing cases by using same-day microscopy would translate into a considerable absolute number, hindering TB control efforts. We question the indiscriminate switch to same-day diagnosis in settings where patients reliably return for testing the next day.

Isolation and characterization of foot-and-mouth disease virus from Odisha, India

Foot-and-mouth disease (FMD) is a highly contagious and rapidly transmissible disease of cloven footed animals. Emergence of genetically divergent strains of FMD virus (FMDV) is a major concern globally. FMD is endemic in India and three serotypes (O, A and Asia 1) prevail. The study was undertaken to characterize the isolates from the state of Odisha, India both genetically and antigenically. FMDV was detected in 7 of the 17 clinical samples collected from FMD affected/suspected animals, in which serotype O and A were found in three and four samples, respectively. Serotype O field isolates clustered in an unnamed group (designated here as Eastern cluster) circulating mostly in the Eastern region of the country and had 10-12.7% divergence from the Ind2001 lineage circulating predominantly throughout the country. The serotype A isolates sequenced in this study was grouped within VP3⁵⁹-deletion group of genotype 18, precisely in clade 18c, having high genetic homology to the virus circulating in the neighboring states, suggesting interstate movement. Both the serotype O and A isolates showed good antigenic relationship value with the respective vaccine strains currently used in the country.

Lack of increased DNA double-strand breaks in peripheral blood mononuclear cells of individuals from high level natural radiation areas of Kerala coast in India

The high level natural radiation area (HLNRA) of Kerala is a 55km long and 0.5km wide strip in south west coast of India. The level of background radiation in this area varies from <1.0mGy/year to 45.0mGy/year. It offers unique opportunity to study the effect of chronic low dose/low dose-rate radiation directly on human population. Spontaneous level of DNA double strand breaks (DSBs) was quantified in peripheral blood mononuclear cells of 91 random individuals from HLNRA (N=61, mean age: 36.1±7.43years) and normal level natural radiation area (NLNRA) (N=30, mean age: 35.5±6.35years) using gamma-H2AX as a marker. The mean annual dose received by NLNRA and HLNRA individuals was 1.28±0.086mGy/year and 8.28±4.96mGy/year, respectively. The spontaneous frequency of DSBs in terms of gamma-H2AX foci among NLNRA and HLNRA individuals were 0.095±0.009 and 0.084±0.004 per cell (P=0.22). The individuals from HLNRA were further classified as low dose group (LDG, 1.51-5.0mGy/year, mean dose: 2.63±0.76mGy/year) and high dose group (HDG, >5.0mGy/year, mean dose: 11.04±3.57mGy/year). The spontaneous frequency of gamma-H2AX foci per cell in NLNRA, LDG and HDG was observed to be 0.095±0.009, 0.096±0.008 and 0.078±0.004 respectively. Individuals belonging to HDG of HLNRA showed marginally lower frequency of DSBs as compared to NLNRA and LDG of HLNRA. This could be suggestive of either lower induction or better repair of DSBs in individuals from HDG of HLNRA. The present study indicated that 5.0mGy/year could be a possible threshold dose for DSB induction at chronic low-dose radiation exposure in vivo. However, further studies on DNA damage induction and repair kinetics are required to draw firm conclusions.

Oxygen isotope in archaeological bioapatites from India: Implications to climate change and decline of Bronze Age Harappan civilization

The antiquity and decline of the Bronze Age Harappan civilization in the Indus-Ghaggar-Hakra river valleys is an enigma in archaeology. Weakening of the monsoon after ~5 ka BP (and droughts throughout the Asia) is a strong contender for the Harappan collapse, although controversy exists about the synchroneity of climate change and collapse of civilization. One reason for this controversy is lack of a continuous record of cultural levels and palaeomonsoon change in close proximity. We report a high resolution oxygen isotope (δ¹⁸O) record of animal teeth-bone phosphates from an archaeological trench itself at Bhirrana, NW India, preserving all cultural levels of this civilization. Bhirrana was part of a high concentration of settlements along the dried up mythical Vedic river valley ‘Saraswati’, an extension of Ghaggar river in the Thar desert. Isotope and archaeological data suggest that the pre-Harappans started inhabiting this area along the mighty Ghaggar-Hakra rivers fed by intensified monsoon from 9 to 7 ka BP. The monsoon monotonically declined after 7 ka yet the settlements continued to survive from early to mature Harappan time. Our study suggests that other cause like change in subsistence strategy by shifting crop patterns rather than climate change was responsible for Harappan collapse.