HIV/Aids epidemic in India and predicting the impact of the national response: mathematical modeling and analysis

After two phases of AIDS control activities in India, the third phase of the National AIDS Control Programme (NACP III) was launched in July 2007. Our focus here is to predict the number of people living with HIV/AIDS (PLHA) in India so that the results can assist the NACP III planning team to determine appropriate targets to be activated during the project period (2007-2012). We have constructed a dynamical model that captures the mixing patterns between susceptibles and infectives in both low-risk and high-risk groups in the population. Our aim is to project the HIV estimates by taking into account general interventions for susceptibles and additional interventions, such as targeted interventions among high risk groups, provision of anti-retroviral therapy, and behavior change among HIV-positive individuals. Continuing the current level of interventions in NACP II, the model estimates there will be 5.06 million PLHA by the end of 2011. If 50 percent of the targets in NACP III are achieved by the end of the above period then about 0.8 million new infections will be averted in that year. The current status of the epidemic appears to be less severe compared to the trend observed in the late 1990s. The projections based on the second phase and the third phase of the NACP indicate prevention programmes which are directed towards the general and high-risk populations, and HIV-positive individuals will determine the decline or stabilization of the epidemic. Model based results are derived separately for the revised HIV estimates released in 2007. We perform a Monte Carlo procedure for sensitivity analysis of parameters and model validation. We also predict a positive role of implementation of anti-retroviral therapy treatment of 90 percent of the eligible people in the country. We present methods for obtaining disease progression parameters using convolution approaches. We also extend our models to age-structured populations

On joint Weibull probability density functions

AbstractTwo important results for the joint probability density function of the Weibull distribution are derived

Acute toxicity of metasystox to wedge clam, Donax cuneatus from west coast

96h acute toxicity tests were performed using commercial grade metasystox on the marine wedge clam, Donax cuneatus during summer 1985. The behaviour and mortality rates were recorded periodically. Most of the dams responded in opening the shell valves and extending the siphons quicker in low test concentrations (0.004-0.0052 p.p.m) but this was slow and late in high concentrations (0.0056-0.008 p.p.m). Mortality began to occur in 0.008 p.p.m. from 12 h, whereas, in 0.0052 p.p.m. from 60 h onwards. The observed LC sub(0) value was 0.004 p.p.m. and LC sub(50) 0.0064 p.p.m. The regression equation established was Y = 79.0891 + 33.4523 X. The rate of oxygen concentration increased at LC sub(0) and LC sub(50) values compared to control indicating the disturbed physiological adjustment. The results are correlated with physico-chemical parameters of seawater and discussed in the light of pesticide toxicity to the dam

Optical Limiting in Single-walled Carbon Nanotube Suspensions

Optical limiting behaviour of suspensions of single-walled carbon nanotubes in water, ethanol and ethylene glycol is reported. Experiments with 532 nm, 15 nsec duration laser pulses show that optical limiting occurs mainly due to nonlinear scattering. The observed host liquid dependence of optical limiting in different suspensions suggests that the scattering originates from microbubbles formed due to absorption-induced heating.Comment: 10 pages, 5 eps figures, to appear in Chem. Phys. Let

A Partition Theorem for a Randomly Selected Large Population

A theorem on the partitioning of a randomly selected large population into stationary and non-stationary components by using a property of the stationary population identity is stated and proved. The methods of partitioning demonstrated are original and these are helpful in real-world situations where age-wise data is available. Applications of this theorem for practical purposes are summarized at the end

A Study of the Gravitational Wave Pulsar Signal with orbital and spindown Effects

In this work we present analytic and numerical treatments of the gravitational wave signal from a pulsar which includes spindown. We consider phase corrections to a received monochromatic signal due to rotational and elliptical orbital motion of the Earth, as well as perturbations due to Jupiter and the Moon. We discuss the Fourier transform of such a signal, which is expressed in terms of well known special functions and lends itself to a tractable numerical analysis.Comment: 8 pages, 8 figures. Write-up of talk given at Theory Canada I, June 2005, University of British Columbi

Studies on Anatomical and Physico-Mechanical Properties of Candidate Plus Culms (CPCs) of Dendrocalamus strictus for Planting Stock Improvement Programme

Five candidate plus culms (CPCs) of about 2-year-old Dendrocalamus strictus (namely 16, 17, 21, 55 and 110) were collected from Sirsi, Karnataka, India, for investigations on anatomical, physical and mechanical properties. Various morphological (inter-nodal length, culm diameter and culm wall thickness), anatomical (fibre length, fibre diameter, fibre lumen diameter, fibre wall thickness and vascular bundles), physical (moisture content and specific gravity) and mechanical (fibre stress at elastic limit-FS at EL, modulus of rupture-MOR and modulus of elasticity-MOE) properties were evaluated for inter-comparison among the CPCs. Among all the CPCs, specific gravity was maximum in CPC 55 and minimum in CPC 17. A comparison of different properties was carried out at 2nd and 4th internode for all the five CPCs. The results indicate that the internodal length was lower in 2nd than 4th internodes with maximum and minimum values observed in CPC 55 and CPC 16 respectively. The culm diameter and culm wall thickness was higher in the 2nd internode than 4th internode. The maximum value of culm wall thickness was observed in CPC 110 and minimum in CPC 21 whereas culm diameter was maximum in CPC 16 and minimum in CPC 17. The fibre morphology did not show significant variation between 2nd and 4th internode among all the CPCs. However, the number of vascular bundles remained more in 4th internode of all the CPCs compared to 2nd internode. While FS at EL was maximum in CPC 55, the minimum corresponding values were found in CPC 110. Similarly, the MOR was maximum in CPC 55 and minimum in CPC 110. The maximum value of MOE was observed in CPC 55 while minimum values was in CPC 16. The data analysis shows that CPCs 55 having superior strength properties is comparatively more suitable for structural applications. CPCs 16 showed most of the anatomical parameters in the higher range and may be utilized for general applications including pulp and paper. The data generated on CPCs may be of use for bamboo improvement program and bamboo plantations which can produce quality product

Tropical fruit tree species and climate change

Tropical fruits – full of rich nutrients and health properties – are adapted to hot and humid environments. Many tropical fruit species might spread beyond their current geographical limit whereas some species might exhibit irregular bearing of fruit. In this context, there are some important questions that need answers: What are the key characteristics that allow farmers to choose a new crop that they are not used to growing? Are farmers already experiencing impacts of climate change? If so, what are their adaptation strategies? Are there new opportunities for capitalizing tropical fruit tree genetic resources that benefit human kind? The study provides a state of knowledge to overcome threats to agriculture and food security, exploring new ways of helping vulnerable rural communities adjust to global changes in climate

Variational and DMRG studies of the Frustrated Antiferromagnetic Heisenberg S=1 Quantum Spin Chain

We study a frustrated antiferromagnetic isotropic Heisenberg $S=1$ chain using a variational ansatz and the DMRG. At $\alpha_D=0.284(1)$, there is a disorder point of the second kind, marking the onset of incommensurate correlations in the chain. At $\alpha_L=0.3725(25)$ there is a Lifshitz point, at which the excitation spectrum develops a doubly degenerate structure. These points are the quantum remnants of the transition from antiferromagnetic to spiral order in the classical frustrated chain. At $\alpha_T=0.7444(6)$ there is a first order phase transition from an AKLT phase to a next-nearest neighbor generalization of the AKLT model. At the transition, the string order parameter shows a discontinuous jump of 0.085 to 0; the correlation length and the gap are both finite at the transition. The problem of edge states in open frustrated chains is discussed at length.Comment: 37 pages, 14 figures, submitted to Phys.Rev.