Preparation of Undoped and Phosphorus Doped μc-Si:H Films: Effect of Extended Period of Hydrogen Plasma Annealing in Interrupted Growth

Interrupted growth and H-plasma annealing of stacking layers of Si:H film resulted in a significant improvement in material properties towards microcrystallization. Increase of dark conductivity and reduction of optical absorption due to extended period of hydrogen plasma exposure was noted. An associated improvement in the network structure towards crystallinity was observed by Raman, TEM and XRD studies. Highly conducting ( σD ~ 6 × 10-3 s. cm-1) undoped mc-Si:H films have been prepared at significantly low thickness of 650 Å. P-doped mc-Si:H films having conductivity ~ 26.2 S.cm-1 were obtained from very low level of PH3 dilution. Large number of dopants introduce additional defects at the grain boundary and inhibits the crystallization process

Surat 2006 Floods: A Citizens’ Report

Surat is situated at the mouth of the river Tapi where it meets the Arabian Sea and has for centuries been a flood-affected area. The most recent floods however, were different because of the magnitude of their effect. Nearly 90 per cent of the households were affected; six of the seven wards of the city had water standing for days. It crippled the economy and affected people's coping abilities. In the wake of the floods the Department of Human Resource Development of the Veer Narmad South Gujarat University and the Centre for Social Studies conducted a study looking at how people coped with the disaster and the impact of the flood on their lives and the economy. It offers some pointers about how the impact can be mitigated in similar situations in the future

Surat 2006 Floods: A Citizens’ Report

Surat is situated at the mouth of the river Tapi where it meets the Arabian Sea and has for centuries been a flood-affected area. The most recent floods however, were different because of the magnitude of their effect. Nearly 90 per cent of the households were affected; six of the seven wards of the city had water standing for days. It crippled the economy and affected people's coping abilities. In the wake of the floods the Department of Human Resource Development of the Veer Narmad South Gujarat University and the Centre for Social Studies conducted a study looking at how people coped with the disaster and the impact of the flood on their lives and the economy. It offers some pointers about how the impact can be mitigated in similar situations in the future

HIV Infection and Host Genetic Mutation among Injecting Drug-users of Northeastern States of India

A community-based cross-sectional study was conducted among injecting drug-users (IDUs) of the northeastern states of India to understand the host genetic factors that confer resistance to HIV infection. The study aimed at assessing the existence and magnitude of genetic mutations of chemokine receptors, such as CCR2-64I, CCR-5 D-32, and SDF-1-3‘A, that are known to confer resistance to HIV infection and progression of disease in some set-ups. In total, 711 IDUs from Manipur, Mizoram, Nagaland, and Meghalaya were sampled for the study. The selected participants were interviewed to study their sociodemography, risk behaviours, and risk perceptions after obtaining their verbal informed consent. The interview was followed by collection of about 5 mL of blood samples by an unlinked anonymous method for studying genetic mutation and HIV infection. All the blood samples were transported to and processed at the clinical medicine laboratory of the National Institute of Cholera & Enteric Diseases, Kolkata, India. The genetic mutations were detected by polymerase chain reaction (PCR) and the restriction fragment length polymorphism (RFLP) assay techniques. The study revealed that 328 (46.1%) IDUs were aged 20–29 years, 305 (42.9%) were aged 30–39 years, and only two (0.3%) were aged above 49 years. The rate of HIV seropositivity varied widely among the IDUs living in different northeastern states that ranged from 4.5% to 61%. There was not a single IDU with CCR5 homozygous mutation. Mutated genes of CCR2-64I and SDF-1-3'A were detected in the frequencies of 49% and 23% respectively in them. The rate of HIV seropositivity in IDUs having CCR2 mutant gene was 27% (n=94) and without mutation was 27% (n=98). Similarly, HIV seropositivity in IDUs with and without SDF1 mutation was 28% (n=46) and 27% (n=146) respectively. Both the differences were not statistically significant. A CCR5 homozygous mutation is known to be the most prominent marker that confers resistance against HIV infection. The absence of CCR5 mutant gene in this population suggests that they do not have any additional protection against HIV infection. Analysis also revealed that, although mutation of CCR2 and SDF1 was present in this population, it did not confer any additional resistance against HIV. This indicates that the IDUs of northeastern India are not additionally protected against HIV infection through genetic mutation and are, therefore, vulnerable to acquire HIV infection due to high-risk behaviour and other related factors

Surat 2006 Floods: A Citizens’ Report

Surat is situated at the mouth of the river Tapi where it meets the Arabian Sea and has for centuries been a flood-affected area. The most recent floods however, were different because of the magnitude of their effect. Nearly 90 per cent of the households were affected; six of the seven wards of the city had water standing for days. It crippled the economy and affected people's coping abilities. In the wake of the floods the Department of Human Resource Development of the Veer Narmad South Gujarat University and the Centre for Social Studies conducted a study looking at how people coped with the disaster and the impact of the flood on their lives and the economy. It offers some pointers about how the impact can be mitigated in similar situations in the future.Surat flood; floods; SMC;

HIV Infection and Host Genetic Mutation among Injecting Drug-users of Northeastern States of India

A community-based cross-sectional study was conducted among injecting drug-users (IDUs) of the northeastern states of India to understand the host genetic factors that confer resistance to HIV infection. The study aimed at assessing the existence and magnitude of genetic mutations of chemokine receptors, such as CCR2-64I, CCR-5 D-32, and SDF-1-3`A, that are known to confer resistance to HIV infection and progression of disease in some set-ups. In total, 711 IDUs from Manipur, Mizoram, Nagaland, and Meghalaya were sampled for the study. The selected participants were interviewed to study their sociodemography, risk behaviours, and risk perceptions after obtaining their verbal informed consent. The interview was followed by collection of about 5 mL of blood samples by an unlinked anonymous method for studying genetic mutation and HIV infection. All the blood samples were transported to and processed at the clinical medicine laboratory of the National Institute of Cholera & Enteric Diseases, Kolkata, India. The genetic mutations were detected by polymerase chain reaction (PCR) and the restriction fragment length polymorphism (RFLP) assay techniques. The study revealed that 328 (46.1%) IDUs were aged 20-29 years, 305 (42.9%) were aged 30-39 years, and only two (0.3%) were aged above 49 years. The rate of HIV seropositivity varied widely among the IDUs living in different northeastern states that ranged from 4.5% to 61%. There was not a single IDU with CCR5 homozygous mutation. Mutated genes of CCR2-64I and SDF-1-3\u2019A were detected in the frequencies of 49% and 23% respectively in them. The rate of HIV seropositivity in IDUs having CCR2 mutant gene was 27% (n=94) and without mutation was 27% (n=98). Similarly, HIV seropositivity in IDUs with and without SDF1 mutation was 28% (n=46) and 27% (n=146) respectively. Both the differences were not statistically significant. A CCR5 homozygous mutation is known to be the most prominent marker that confers resistance against HIV infection. The absence of CCR5 mutant gene in this population suggests that they do not have any additional protection against HIV infection. Analysis also revealed that, although mutation of CCR2 and SDF1 was present in this population, it did not confer any additional resistance against HIV. This indicates that the IDUs of northeastern India are not additionally protected against HIV infection through genetic mutation and are, therefore, vulnerable to acquire HIV infection due to high-risk behaviour and other related factors

TDP1 deficiency sensitizes human cells to base damage via distinct topoisomerase I and PARP mechanisms with potential applications for cancer therapy

Base damage and topoisomerase I (Top1)-linked DNA breaks are abundant forms of endogenous DNA breakage, contributing to hereditary ataxia and underlying the cytotoxicity of a wide range of anti-cancer agents. Despite their frequency, the overlapping mechanisms that repair these forms of DNA breakage are largely unknown. Here, we report that depletion of Tyrosyl DNA phosphodiesterase 1 (TDP1) sensitizes human cells to alkylation damage and the additional depletion of apurinic/apyrimidinic endonuclease I (APE1) confers hypersensitivity above that observed for TDP1 or APE1 depletion alone. Quantification of DNA breaks and clonogenic survival assays confirm a role for TDP1 in response to base damage, independently of APE1. The hypersensitivity to alkylation damage is partly restored by depletion of Top1, illustrating that alkylating agents can trigger cytotoxic Top1-breaks. Although inhibition of PARP activity does not sensitize TDP1-deficient cells to Top1 poisons, it confers increased sensitivity to alkylation damage, highlighting partially overlapping roles for PARP and TDP1 in response to genotoxic challenge. Finally, we demonstrate that cancer cells in which TDP1 is inherently deficient are hypersensitive to alkylation damage and that TDP1 depletion sensitizes glioblastoma-resistant cancer cells to the alkylating agent temozolomide

X-ray tomography studies on porosity and particle size distribution in cast in-situ Al-Cu-TiB2 semi-solid forged composites

X-ray computed tomography (XCT) was used to characterise the internal microstructure and clustering behaviour of TiB2 particles in in-situ processed Al-Cu metal matrix composites prepared by casting method. Forging was used in semi-solid state to reduce the porosity and to uniformly disperse TiB2 particles in the composite. Quantification of porosity and clustering of TiB2 particles was evaluated for different forging reductions (30% and 50% reductions) and compared with an as- cast sample using XCT. Results show that the porosity content was decreased by about 40% due to semi-solid forging as compared to the as-cast condition. Further, XCT results show that the 30% forging reduction resulted in greater uniformity in distribution of TiB2 particles within the composite compared to as-cast and the 50% forge reduction in semi-solid state. These results show that the application of forging in semi-solid state enhances particle distribution and reduces porosity formation in cast in-situ Al-Cu-TiB2 metal matrix composites