Operational experience of electronic active personal dosemeter and comparison with CaSo4:Dy TL dosemeter in Indian PHWR.

Direct reading dosemeter has been used for day-to-day radiation exposure control and management for last four decades in Indian nuclear power plants (NPPs). Recently new real time, alarm and pre-alarm on equivalent dose/dose rate, storage of dose/dose rate and maximum dose rate, user-friendly electronic active personal dosemeter (APD) has been implemented into practice for the first time at Kaiga Atomic Power Station-3&4,  of Indian NPPs. The dosemeter showed tolerance level (L) 0.1085±0.0450 compared with 0.1869±0.0729 (average±SD) for CaSO4:Dy, TL dosemeter, having narrow range trumpet curve, nil electromagnetic interference. Records of >29 000 for APD and TL dosemeter were analysed for comparasion of the measurement of the individual dose. APD followed general acceptance rule of ±25 % for dose >1 mSv. Monthly Station collective dose by TL dosemeters and APD for normal reactor operation as well as outage are found in good agreement. Operational experiences and statistical analysis support that an APD dosemeter is reasonably equivalent to CaSO4:Dy TL dosemeter. The accuracy, reproducibility and repeatability of the measurement of radiation for (137)Cs are comparable with CaSO4:Dy, TL dosemeter. Operational experience of APD during the normal operation as well as outage showed as one of the best ALARA tool for occupational dose monitoring, control, management and future outage planning.

In vitro antimalarial activity and molecular docking analysis of 4-aminoquinoline-clubbed 1,3,5-triazine derivatives.

AIMS: Present report describes the in vitro antimalarial activity and docking analysis of seven 4-aminoquinoline-clubbed 1,3,5-triazine derivatives on pf-DHFR-TS. METHODS AND RESULTS: The antimalarial activity was evaluated in vitro against chloroquine-sensitive 3D7 strain of Plasmodium falciparum. Compounds were docked onto the active site of pf-DHFR-TS using docking server to explicate necessary structural requirements for antimalarial activity. CONCLUSION: Title molecules demonstrated considerable bioactivity against the malaria parasite. Docking analysis revealed deep engulfment of the molecules into the inner groove of pf-DHFR-TS active site by making stable ligand-receptor posses. Hydrophobic interaction was identified as the only major interacting force playing a role between ligand-receptor interaction and minor with hydrogen bonds. SIGNIfiCANCE AND IMPACT OF THE STUDY: The study provided the novel insight into the necessary structural requirement for rationale-based antimalarial drug discovery.

Quick management of accidental tritium exposure cases.

Removal half-life (RHL) of tritium is one of the best means for optimising medical treatment, reduction of committed effective dose (CED) and quick/easy handling of a large group of workers for medical treatment reference. The removal of tritium from the body depends on age, temperature, relative humidity and daily rainfall; so tritium removal rate, its follow-up and proper data analysis and recording are the best techniques for management of accidental acute tritium exposed cases. The decision of referring for medical treatment or medical intervention (MI) would be based on workers' tritium RHL history taken from their bodies at the facilities. The workers with tritium intake up to 1 ALI shall not be considered for medical treatment as it is a derived limit of annual total effective dose. The short-term MI may be considered for tritium intake of 1-10 ALI; however, if the results show intake ≥100 ALI, extended strong medical/therapeutic intervention may be recommended based on the severity of exposure for maximum CED reduction requirements and annual total effective dose limit. The methodology is very useful for pressurized heavy water reactors (PHWRs) which are mainly operated by Canada and India and future fusion reactor technologies. Proper management will optimise the cases for medical treatment and enhance public acceptance of nuclear fission and fusion reactor technologies.

Antifungal activity, SAR and physicochemical correlation of some thiazole-1,3,5-triazine derivatives.

OBJECTIVE: Present research communication was towards the investigation of antifungal minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) activity of some substituted clubbed thiazole-1,3,5-triazines derivatives and effect of physicochemical properties on bioactivity. MATERIAL AND METHODS: MIC and MFC were evaluated against Candida albicans, Candida glabrata, Cryptococcus neoformans and Aspergillus niger using modified microdilution method recommended by CLSI. Cytotoxicity was determinate on the viability of marine shrimp larvaes. SAR and physicochemical correlations were studied by Molinspiration software. RESULTS: The 5 and 9 derivatives showed an excellent antifungal activity with MIC lower than fluconazole and equivalent to amphotericin B specially against C. albicans and C. glabrata. The toxicity of these two derivatives was non-existent for 5 and moderate for 9 at the used concentration. SAR study around prototype molecule suggests that presence of di-hydrophobic fragment on 1,3,5-triazine is necessary for antifungal activity than halogen substituted aromatic amine. CONCLUSION: On the basis of selectivity, potency and non-toxicity, we have obtained two molecules (5 and 9) as prospective leads for further research work on 1,3,5-triazine as antifungal drug.

Estimation of biological half-life of tritium in coastal region of India.

The present study estimates biological half-life (BHL) of tritium by analysing routine bioassay samples of radiation workers. During 2007-2009 year, 72,100 urine bioassay samples of the workers were analysed by liquid scintillation counting technique for internal dose monitoring for tritium. Two hundred and two subjects were taken for study with minimum 3 µCiL(-1) tritium uptake in their body fluid. The BHL of tritium of subjects ranges from 1 to 16 d with an average of 8.19 d. Human data indicate that the biological retention time ranges from 4 to 18 d with an average of 10 d. The seasonal variations of the BHL of tritium are 3.09 ± 1.48, 6.87 ± 0.58 and 5.73 ± 0.76 d (mean ± SD) for summer, winter and rainy seasons, respectively, for free water tritium in the coastal region of Karnataka, India, which shows that the BHL in summer is twice that of the winter season. Also three subjects showed the BHL of 101.73-121.09 d, which reveals that organically bound tritium is present with low tritium uptake also. The BHL of tritium for all age group of workers is observed independent of age and is shorter during April to May. The distribution of cumulative probability vs. BHL of tritium shows lognormal distribution with a geometric mean of 9.11 d and geometric standard deviation of 1.77 d. The study of the subjects is fit for two-compartment model and also an average BHL of tritium is found similar to earlier studies.

Genetic consequences of polygyny and social structure in an Indian fruit bat, Cynopterus sphinx. I. Inbreeding, outbreeding, and population subdivision.

Population subdivision into behaviorally cohesive kin groups influences rates of inbreeding and genetic drift and has important implications for the evolution of social behavior. Here we report the results of a study designed to test the hypothesis that harem social structure promotes inbreeding and genetic subdivision in a population with overlapping generations. Genetic consequences of harem social structure were investigated in a natural population of a highly polygynous fruit bat, Cynopterus sphinx (Chiroptera: Pteropodidae), in western India. The partitioning of genetic variance within and among breeding groups was assessed using 10-locus microsatellite genotypes for 431 individually marked bats. Genetic analysis of the C. sphinx study population was integrated with field data on demography and social structure to determine the specific ways in which mating, dispersal, and new social group formation influenced population genetic structure. Microsatellite data revealed striking contrasts in genetic structure between consecutive offspring cohorts and between generations. Relative to the 1998 (dry-season) offspring cohort, the 1997 (wet-season) cohort was characterized by a more extensive degree of within-group heterozygote excess (F(IS) = -0.164 vs. -0.050), a greater degree of among-group subdivision (F(ST) = 0.123 vs. 0.008), and higher average within-group relatedness (r = 0.251 vs. 0.017). Differences in genetic structure between the two offspring cohorts were attributable to seasonal differences in the number and proportional representation of male parents. Relative to adult age-classes, offspring cohorts were characterized by more extensive departures from allelic and genotypic equilibria and a greater degree of genetic subdivision. Generational differences in F-statistics indicated that genetic structuring of offspring cohorts was randomized by natal dispersal prior to recruitment into the breeding population. Low relatedness among harem females (r = 0.002-0.005) was primarily attributable to high rates of natal dispersal and low rates of juvenile survivorship. Kin selection is therefore an unlikely explanation for the formation and maintenance of behaviorally cohesive breeding groups in this highly social mammal.

Genetic consequences of polygyny and social structure in an Indian fruit bat, Cynopterus sphinx. II. Variance in male mating success and effective population size.

Variance in reproductive success is a primary determinant of genetically effective population size (Ne), and thus has important implications for the role of genetic drift in the evolutionary dynamics of animal taxa characterized by polygynous mating systems. Here we report the results of a study designed to test the hypothesis that polygynous mating results in significantly reduced Ne in an age-structured population. This hypothesis was tested in a natural population of a harem-forming fruit bat, Cynopterus sphinx (Chiroptera: Pteropodidae), in western India. The influence of the mating system on the ratio of variance Ne to adult census number (N) was assessed using a mathematical model designed for age-structured populations that incorporated demographic and genetic data. Male mating success was assessed by means of direct and indirect paternity analysis using 10-locus microsatellite genotypes of adults and progeny from two consecutive breeding periods (n = 431 individually marked bats). Combined results from both analyses were used to infer the effective number of male parents in each breeding period. The relative proportion of successfully reproducing males and the size distribution of paternal sibships comprising each offspring cohort revealed an extremely high within-season variance in male mating success (up to 9.2 times higher than Poisson expectation). The resultant estimate of Ne/N for the C. sphinx study population was 0.42. As a result of polygynous mating, the predicted rate of drift (1/2Ne per generation) was 17.6% higher than expected from a Poisson distribution of male mating success. However, the estimated Ne/N was well within the 0.25-0.75 range expected for age-structured populations under normal demographic conditions. The life-history schedule of C. sphinx is characterized by a disproportionately short sexual maturation period scaled to adult life span. Consequently, the influence of polygynous mating on Ne/N is mitigated by the extensive overlap of generations. In C. sphinx, turnover of breeding males between seasons ensures a broader sampling of the adult male gamete pool than expected from the variance in mating success within a single breeding period.

Inheritance of oral susceptibility of Aedes aegypti to Chikungunya virus.

A colony of rosy eye mutants of Aedes aegypti was established. This strain was refractory to Chikungunya virus by oral route of infection when compared with the wild-type parent strain. The refractoriness of this strain seems to be due to a mesentronal barrier, since both the mosquito strains supported the multiplication of virus after intrathoracic inoculation. The rosy eye strain was also found to be refractory to Sagiyama virus (Alphaviridae: Getah virus subtype) when compared with wild-type parent strain, but no such difference in the oral susceptibility was found with dengue-2 (Flaviviridae) virus. The rosy eye mutant appears to be closely linked to the gene(s) for refractoriness to alpha viruses and may be useful in future studies in understanding the genetic basis of vector competence of Ae. aegypti to arboviruses.

Persistence of haemagglutination-inhibition antibodies to JE and WN viruses in naturally infected domestic pigs in Karnataka State, India.

Domestic pigs were used as sentinels to monitor the prevalence of Japanese encephalitis (JE) and West Nile (WN) viruses in Kolar District of Karnataka State, India. The study revealed that the pigs once seroconverted to JE and WN viruses, remained immune as long as they were available for observation, up to three years.

Isolation of Batai virus from sentinel domestic pig from Kolar district in Karnataka State, India.

Batai virus was isolated from the blood sample of one sentinel piglet out of 34 used to monitor the activity of the Japanese encephalitis (JE) virus at Madikere village in Kolar district, Karnataka State, India. This is the first report of the isolation of Batai virus from a mammal.

Studies on the mosquito vectors of Japanese encephalitis virus in Mandya District, Karnataka, India.

Entomological investigations were carried out in areas affected by Japanese encephalitis (JE) in Mandya District, Karnataka, India, from 1983 to 1988, to determine species composition and the density of mosquito vectors, in relation to the incidence of JE cases. JE cases occurred in two spells in a year, one during April-June (summer epidemic) and another during October-December (winter epidemic). There was very high incidence of JE cases in extensively irrigated areas and a low incidence in some of the taluks with less or no irrigation systems. Among culicines, Culex tritaeniorhynchus was the most predominant species (20.54%), followed by Cx. fuscocephala (16.94), Cx. vishnui (16.48%), Cx. gelidus (10.70%) and other species. The overall mosquito population showed two peaks in a year, one during the March-April, and another during September, usually preceding the human epidemics. Relative abundance of certain species varied in different years.

Monitoring Japanese encephalitis virus activity using domestic sentinel pigs in Mandya district, Karnataka state (India).

Domestic pigs were used as sentinels in Mandya district (Karnataka state) in India during 1984 to 1986 to monitor the activity of Japanese encephalitis (JE) virus in nature. Out of 213 sentinel pigs studied in 11 localities, 44 pigs placed at 5 localities showed seroconversion to Japanese encephalitis virus. A pig mosquito cycle, operating throughout the year appears to be one of the maintenance mechanisms of the virus in the study area in addition to the bird-mosquito cycle.

Preliminary observations on myiasis in leprosy patients.

Out of 3350 leprosy patients attending the surgical outpatient department for various ulcerative lesions, 18 patients had typical symptoms of myiasis. Maggots were collected in 5 cases from the nose, in 3 cases from ulcers of the hand and in 10 cases from ulcers of the foot. It was possible to rear the maggots into flies in 8 out of 18 cases. The flies were identified as Sarcophaga ruficornis and Chrysomyia bezziana.

Japanese encephalitis virus infection in mosquitoes reared from field-collected immatures and in wild-caught males.

Immature stages of mosquitoes collected in JE endemic areas of Karnataka, India between 1985 and 1987 were reared to adults and processed for the detection and isolation of Japanese encephalitis (JE) virus in an attempt to find naturally occurring vertical transmission of the virus. Males collected during 1985-1986 were also processed. A total of 15,785 adults reared from immatures and divided into 445 pools and 1,756 wild-collected males divided into 128 pools were processed using mosquito inoculation and immunofluorescence techniques. JE virus antigen was detected in 9 pools, 4 of which yielded JE virus. These were 2 pools of males and 1 pool of female Culex tritaeniorhynchus and 1 pool of male C. pseudovishnui, suggesting vertical transmission of JE virus in the mosquitoes.

Isolation of Japanese encephalitis virus from mosquitoes collected in Karnataka state, India from 1985 to 1987.

Detection and isolation of Japanese encephalitis (JE) virus using mosquito inoculation and immunofluorescence techniques were attempted from female mosquitoes collected in JE endemic areas of Kolar and Mandya districts of Karnataka state, India, from 1985 to 1987. 65,388 mosquitoes consisting of 19 species in 1541 pools were processed. Of these, 18 pools showed the presence of JE virus antigen. JE virus was isolated from 9 pools, 3 of Culex gelidus, 2 of C. tritaeniorhynchus, and one each of C. quinquefasciatus, C. fuscocephala, C. vishnui and Anopheles peditaeniatus. Isolation of JE virus from C. gelidus, C. fuscocephala, C. quinquefasciatus and An. peditaeniatus is reported for the first time in India.

The epizootics of Kyasanur Forest disease in wild monkeys during 1964 to 1973.

In the Kyasanur Forest disease area two species of wild monkeys, Presbytis entellus and Macaca radiata, succumb to the natural infection with Kyasanur Forest disease (KFD) virus (family Flaviviridae). Between October 1964 and September 1973, 1046 monkeys (860 P. entellus and 186 M. radiata) died. Of these, KFD virus was isolated from 118 P. entellus and 13 M. radiata. Maximum mortality of monkeys was reported during December through May coinciding with the season of activity of immature stages of Haemaphysalis ticks, incriminated vectors of KFD. The epizootic showed an initial spread of the disease to the areas contiguous with the original focus of infection. This was followed by the recognition of epizootics and epidemics in three new foci, removed from the original focus, by the end of 1973. It was also observed that, in certain localities in the original focus, KFD virus activity persisted over several years.