Dissociation dynamics of transient anion formed via electron attachment to sulfur dioxide

We report the molecular dynamics of dissociative electron attachment to sulfur dioxide (SO2) by measuring the momentum distribution of fragment anions using the velocity slice imaging technique in the electron energy range of 2–10 eV. The S- channel results from symmetric dissociation which exhibits competition between the stretch mode and bending mode of vibration in the excited parent anion. The asymmetric dissociation of parent anions leads to the production of O- and SO- channels where the corresponding neutral fragments are formed in their ground as well as excited electronic states. We also identify that internal excitation of SO- is responsible for its low yield at higher electron energies

Integrator Windup Protection-Techniques and a STOVL Aircraft Engine Controller Application

Integrators are included in the feedback loop of a control system to eliminate the steady state errors in the commanded variables. The integrator windup problem arises if the control actuators encounter operational limits before the steady state errors are driven to zero by the integrator. The typical effects of windup are large system oscillations, high steady state error, and a delayed system response following the windup. In this study, methods to prevent the integrator windup are examined to provide Integrator Windup Protection (IW) for an engine controller of a Short Take-Off and Vertical Landing (STOVL) aircraft. An unified performance index is defined to optimize the performance of the Conventional Anti-Windup (CAW) and the Modified Anti-Windup (MAW) methods. A modified Genetic Algorithm search procedure with stochastic parameter encoding is implemented to obtain the optimal parameters of the CAW scheme. The advantages and drawbacks of the CAW and MAW techniques are discussed and recommendations are made for the choice of the IWP scheme, given some characteristics of the system

X-ray photoemission study of NiS_{2-x}Se_x (x = 0.0 - 1.2)

Electronic structure of NiS_{2-x}Se_x system has been investigated for various compositions (x) using x-ray photoemission spectroscopy. An analysis of the core level as well as the valence band spectra of NiS_2 in conjunction with many-body cluster calculations provides a quantitative description of the electronic structure of this compound. With increasing Se content, the on-site Coulomb correlation strength (U) does not change, while the band width W of the system increases, driving the system from a covalent insulating state to a pd-metallic state.Comment: 19 pages, 6 figures, To appear in Phys. Rev. B, 200

Morbidity patterns in Kerala : levels and determinants

This paper examines the levels, patterns, and determinants of morbidity in Kerala. This study is based on a community survey conducted in 2004, in three districts of the state namely Thiruvananthapuram, Malappuram and Kannur. The survey covers 3320 households having 17071 individuals in all age groups. Reported morbidity was captured for a period of fifteen days prior to the data of survey. Life course analysis was performed to understand the risk of morbidity at various stages, like infancy, early childhood, late childhood, adolescence, reproductive ages and old age, in relation to the impact of socio-economic, demographic and regional factors. The level of morbidity is high in Kerala. Generally, higher levels of morbidity have been observed among females, schedule castes, and schedule tribes as compared to their counter parts. Socio-economic and demographic determinants of morbidity varies both region and across various stages of life course. Females are at greater risk of morbidity than males. The risk of morbidity is significantly higher for illiterates and non-formal literate than persons with higher education. Among the important socio-economic determinants, education and SES showed a negative relationship with morbidity. The risk of morbidity for females is lower than males till the age of 34 years and thereafter it reverse. Poor are at greater risk of morbidity than the rich. Disease specific prevalence rate are computed according to the classification manual of World Health Organization. Communicable diseases are coming down in the state. However, non-communicable diseases are mounting irrespective of socio-economic conditions. Major ten diseases with their co-existing ailments were analysed in detail. Most of the diseases prevalent in Kerala warrant constant medical attention and treatment and sustained medical treatment is beyond the wherewithal of the average households. The private health care system cannot be an answer because of the high average cost of treatment. This warrants greater and sustained efforts by the State in widening the scope of public action. Key words: Health Status, Morbidity, Levels and Determinants, life Course Perspective, Kerala JEL Classification: I10, I12

Indian summer monsoon precipitation climatology in a high-resolution regional climate model: Impacts of convective parameterization on systematic biases

In an attempt to develop a better simulation of the climatology of monsoon precipitation in climate models, this paper investigates the impacts of different convective closures on systematic biases of an Indian monsoon precipitation climatology in a high-resolution regional climate model. For this purpose, the Weather Research Forecast (WRF) model is run at 45- and 15-km (two-way nested) resolution with three convective parameterization schemes, namely the Grell-Devenyi (GD), the Betts-Miller-Janji (BMJ), and the Kain-Fritsch (KF), for the period 1 May-31 October 2001-07. The model is forced with the NCEP-NCAR reanalysis data as the initial and boundary conditions. The simulated June-September (JJAS) mean monsoon rainfall with the three convective schemes is compared with the observations. KF is found to have a high moist bias over the central and western coastal Indian region while GD shows the opposite. Among the three, BMJ is able to produce a reasonable mean monsoon pattern. In an attempt to get further insight into the seasonal bias and its evolution, the probability distribution function (PDF) of different rain-rate categories and their percentage contribution to the seasonal total are computed. BMJ and KF underestimate the observations for lighter rain rates and overestimate for rain-rate categories of more than 10 mm day -1. GD shows an overestimation for lighter rain and an underestimation of PDF for moderate categories. The seasonal patterns of evolution of PDF plots of three rain-rate categories are analyzed to determine whether the convective schemes show any systematic bias throughout the season or if they have problems during certain phases of the monsoon. This shows that the GD systematically overestimates the lighter rain rate and underestimates the moderate rain rate throughout the season, whereas BMJ and KF have problems in the initial stages. The heavy rain category is systematically overestimated by the KF compared to the other two. To further evaluate the proportionate contribution of each rain-rate bin to the total rain, the percentage contribution of each rain rate to the seasonal total is computed. Analyzing all the rain-rate simulations produced by the three schemes, it is found that KF has a moist bias and GD has a dry bias in the spatiotemporal distribution of the monsoon precipitation. Further, this paper investigates the causes behind the mean monsoon precipitation bias. It is shown that GD produces a model climate where the vertical velocity is less than that of the observations up to 500 hPa and the vertically integrated moist instability is also weaker. KF, on the other hand, shows a higher than the observed vertical velocity and a stronger moist instability. Along with this, the vertical profile of heating suggests a warmer middle level in the KF case and significantly reduced midlevel heating for GD. Thus, KF (GD) has produced a model atmosphere that has a stronger (weaker) convective instability to produce the observed bias in the model precipitation. BMJ is found to simulate a reasonable heating profile, along with the realistic moist instability and seasonal cycle of evaporation and condensation. Insight derived from the analysis is expected to help improve the convective parameterizations

Biomarkers of environmental contaminants in field population of green mussel (Perna viridis) from Karnataka-Kerala coast (South West coast of India)

The green mussel Perna viridis was sampled from relatively clean and contaminated sites along the Kartanata-Kerala coast (south west coast of India) to study the tissue concentration of trace metals and biological responses to stress (biomarkers) such as sister chromatid exchange (SCE), chromosomal aberration, micronucleus (MN) test, hemic neoplasia (HN), Chromotest (Ames test) and comet assay

Heavy metal distribution in the biotic and abiotic matrices along Karnataka coast, west coast of India

Sediment and soft tissue of bivalve samples collected from various sites of Karnataka coast were analysed for the estimation of the nanaal and anthropogenic heavy metal fluxes. Seasonal variations of heavy metals in sediment and bivalves collected from selected hot spots from Binage, Karwar and Thannirbavi, Mangalore were monitored. High concentrations of Hg was observed in the environment near' the vicinity of a caustic soda plant at Binage, Karwar, indicating Hg pollution. Total Hg concentration in the tissue of oysters sampled from a contaminated stream from the above site, exceeded the safe limit of 0.5 ilg g.1 wet weight. The base-line heavy metal concentrations in sediment and bivalves from selected sites of coastal Karnataka are presented

Accumulation of trace metals in green mussel Perna viridis in the shellfish harvesting environment along southern Karnataka coast

The levels of trace metals, Cd, Pb, Cu, Zn, Ni and Fe in seawater and their bioaccumulation in green mussel Perna viridis were examined in two shellfish harvesting environments, Someshwara and Surathkal, along the southern Karnataka coast. In seawater, the concentration of trace metals analysed were below the levels causing harmful effects on the larvae and adult mussels, set by the European Council Directive 79/923/EEC. The Fe, Ni, Cd and Zn levels in mussel tissue from Surathkal were relatively higher when compared to that of mussel tissue samples from Someshwara while Cu and Pb levels were lower. The mean tissue concentrations of trace metals in the soft tissue of P. viridis from shellfish waters were found to be safe and below the permissible concentrations for seafood (US FDA and WHO) as well as EU limits in marine products

Diagnostic circulating biomarkers to detect vision-threatening diabetic retinopathy: Potential screening tool of the future?

With the increasing prevalence of diabetes in developing and developed countries, the socio-economic burden of diabetic retinopathy (DR), the leading complication of diabetes, is growing. Diabetic retinopathy (DR) is currently one of the leading causes of blindness in working-age adults worldwide. Robust methodologies exist to detect and monitor DR; however, these rely on specialist imaging techniques and qualified practitioners. This makes detecting and monitoring DR expensive and time-consuming, which is particularly problematic in developing countries where many patients will be remote and have little contact with specialist medical centres. Diabetic retinopathy (DR) is largely asymptomatic until late in the pathology. Therefore, early identification and stratification of vision-threatening DR (VTDR) is highly desirable and will ameliorate the global impact of this disease. A simple, reliable and more cost-effective test would greatly assist in decreasing the burden of DR around the world. Here, we evaluate and review data on circulating protein biomarkers, which have been verified in the context of DR. We also discuss the challenges and developments necessary to translate these promising data into clinically useful assays, to detect VTDR, and their potential integration into simple point-of-care testing devices