Search

We present a theory to quantify the formation of spatiotemporal macrostructures (or the non-homogeneous regions of high viscosity at moderate to high fluid inertia) for viscoelastic sub-diffusive flows, by introducing a mathematically consistent decomposition of the polymer conformation tensor, into the so-called structure tensor. Our approach bypasses an inherent problem in the standard arithmetic decomposition, namely, the fluctuating conformation tensor fields may not be positive definite and hence, do not retain their physical meaning. Using well-established results in matrix analysis, the space of positive definite matrices is transformed into a Riemannian manifold by defining and constructing a geodesic via the inner product on its tangent space. This geodesic is utilized to define three scalar invariants of the structure tensor, which do not suffer from the caveats of the regular invariants (such as trace and determinant) of the polymer conformation tensor. First, we consider the problem of formulating perturbative expansions of the structure tensor using the geodesic, which is consistent with the Riemannian manifold geometry. A constraint on the maximum time, during which the evolution of the perturbative solution can be well approximated by linear theory along the Euclidean manifold, is found. A comparison between the linear and the nonlinear dynamics, identifies the role of nonlinearities in initiating the symmetry breaking of the flow variables about the centerline. Finally, fully nonlinear simulations of the viscoelastic sub-diffusive channel flows, underscore the advantage of using these invariants in effectively quantifying the macrostructures. [ABSTRACT FROM AUTHOR]

Background/objectives: Multi-nutrient insufficiencies as a consequence of nutritional and economic factors are common in India and other developing countries. We have examined the impact of multi-nutrient insufficiency on markers of one carbon (1C) metabolism in the blood, and response to a methionine load in clinically healthy young women.Subjects/methods: Young women from Pune, India (n=10) and Cleveland, USA (n=13) were studied. Blood samples were obtained in the basal state and following an oral methionine load (50 mg/kg of body weight in orange juice). Plasma concentrations of vitamin B12, folate and B6 were measured in the basal state. The effect of methionine load on the levels of methionine, total homocysteine, cysteine, glutathione and amino acids was examined.Results: Indian women were significantly shorter and lighter compared with the American women and had lower plasma concentration of vitamins B12, folate and B6, essential amino acids and glutathione, but higher concentration of total homocysteine. The homocysteine response to methionine load was higher in Indian women. The plasma concentrations of glycine and serine increased in the Indian women after methionine (in juice) load. A significant negative correlation between plasma B6 and homocysteine (r= -0.70), and plasma folate and glycine and serine levels were observed in the Indian group (P<0.05) but not in the American group.Conclusions: Multi-nutrient insufficiency in the Indian women caused unique changes in markers of whole body protein and 1C metabolism. These data would be useful in developing nutrient intervention strategies. [ABSTRACT FROM AUTHOR]

Eleven populations of the tetraploid Oryza officinalis Wall ex Watt were collected from five forest ranges along the Western Ghats in Kerala, South India. Multivariate discriminant analysis using 15 morphological characters revealed a high degree of variation within the taxon. Such infra-specific taxonomic diversity points to the perpetuation of the polyploid segregants at different localities as a result of selection under varying micro ecosystems. [ABSTRACT FROM AUTHOR]

A year round study was conducted in Trivandrum city during the period of March 1984 to February 1985 to elucidate the relation between certain physico-chemical factors and seasonal density of Mansonia larvae (Culicidae: Diptera). Mansonia uniformis was found to be the predominant species during this period, whereas Mansonia annulifera was less than 10% of the total Mansonia collected. The period of high prevalence was found to be January-March. Out of the 6 physico-chemical factors studied Na, K, and pH showed statistically significant correlation with the larval density, while Ca, Mg and rainfall showed no significant relation. [ABSTRACT FROM AUTHOR]

A study relating to seasonal prevalence and host visitation of Mansonia mosquitoes in Trivandrum city was carried out between August 1984 and July 1985. The area chosen was the one which is a perennial breeding source for Mansonia mosquitoes. Only Mansonia uniformis and Mansonia annulifera were prevalent in this area of which the former was found to be the predominant species. Decrease in the number of Mansonia annulifera from the survey conducted during the previous year may be due to the disappearance of Pistia stratiotes and its replacement by Salvinia auriculata. Rainfall and temperature are the two important environmental factors which influence the number of Mansonia mosquitoes visiting the host. The maximum number of adults of Mansonia uniformis was collected during February to June 1985. No swarm of Mansonia uniformis was encountered during the present study, however, males were found to wait and mate with the resting as well as blood fed females in the vicinity of the host. Both sexes of Mansonia mosquitoes were parasitized by Arrenurus and limnesiid species of water mites. Maximum parasitization was seen during July 1985. [ABSTRACT FROM AUTHOR]

A patient with early onset of myotonic dystrophy, with associated neuropathy and epilepsy, is presented. It is postulated that his disorder was inherited through a recessive, pleomorphic gene. His differential diagnosis is discussed and the literature reviewed. The clinical variability of myotonic dystrophy is stressed and the diagnostic difficulties encountered in the younger age group. [ABSTRACT FROM AUTHOR]

Clinicopathological correlations are presented in a case of facial myokymia with facial palsy. The causative lesions were considered to be metastatic tumours to the pons and it was concluded that both the facial palsy and the myokymia were due to interruption of supranuclear pathways impinging on the facial nucleus. [ABSTRACT FROM PUBLISHER]