Effective Rheology of Bubbles Moving in a Capillary Tube

We calculate the average volumetric flux versus pressure drop of bubbles moving in a single capillary tube with varying diameter, finding a square-root relation from mapping the flow equations onto that of a driven overdamped pendulum. The calculation is based on a derivation of the equation of motion of a bubble train from considering the capillary forces and the entropy production associated with the viscous flow. We also calculate the configurational probability of the positions of the bubbles.Comment: 4 pages, 1 figur

What do we know about chronic kidney disease in India: first report of the Indian CKD registry

<p>Abstract</p> <p>Background</p> <p>There are no national data on the magnitude and pattern of chronic kidney disease (CKD) in India. The Indian CKD Registry documents the demographics, etiological spectrum, practice patterns, variations and special characteristics.</p> <p>Methods</p> <p>Data was collected for this cross-sectional study in a standardized format according to predetermined criteria. Of the 52,273 adult patients, 35.5%, 27.9%, 25.6% and 11% patients came from South, North, West and East zones respectively.</p> <p>Results</p> <p>The mean age was 50.1 ± 14.6 years, with M:F ratio of 70:30. Patients from North Zone were younger and those from the East Zone older. Diabetic nephropathy was the commonest cause (31%), followed by CKD of undetermined etiology (16%), chronic glomerulonephritis (14%) and hypertensive nephrosclerosis (13%). About 48% cases presented in Stage V; they were younger than those in Stages III-IV. Diabetic nephropathy patients were older, more likely to present in earlier stages of CKD and had a higher frequency of males; whereas those with CKD of unexplained etiology were younger, had more females and more frequently presented in Stage V. Patients in lower income groups had more advanced CKD at presentation. Patients presenting to public sector hospitals were poorer, younger, and more frequently had CKD of unknown etiology.</p> <p>Conclusions</p> <p>This report confirms the emergence of diabetic nephropathy as the pre-eminent cause in India. Patients with CKD of unknown etiology are younger, poorer and more likely to present with advanced CKD. There were some geographic variations.</p

Viscoelastic phenomenology based structure assignment for closed-loop vibration control of a beam with sensors and actuators

In this paper we incorporate a novel approach to synthesize a class of closed-loop feedback control, based on the variational structure assignment. Properties of a viscoelastic system are used to design an active feedback controller for an undamped structural system with distributed sensor, actuator and controller. Wave dispersion properties of onedimensional beam system have been studied. Efficiency of the chosen viscoelastic model in enhancing damping and stability properties of one-dimensional viscoelastic bar have been analyzed. The variational structure is projected on a solution space of a closed-loop system involving a weakly damped structure with distributed sensor and actuator with controller. These assign the phenomenology based internal strain rate damping parameter of a viscoelastic system to the usual elastic structure but with active control. In the formulation a model of cantilever beam with non-collocated actuator and sensor has been considered. The formulation leads to the matrix identification problem of two dynamic stiffness matrices. The method has been simplified to obtain control system gains for the free vibration control of a cantilever beam system with collocated actuator-sensor, using quadratic optimal control and pole-placement methods

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Not AvailableLeptin is supposed to play a crucial role in ovarian luteal dynamics. The present study was aimed to investigate the importance of leptin and its receptors in buffalo corpus luteum (CL) obtained from different stages of the estrous cycle. Real-time RT-PCR (qPCR), western blot and immunohistochemistry techniques were applied to investigate mRNA expression, protein expression and localization of examined factors. Additionally to assess the contribution of leptin in progesterone production the expression profiles of StAR, P450scc and HSD were also investigated. In general, we demonstrated presence of leptin and its receptors in buffalo CL during the estrous cycle. The mRNA levels of leptin and its receptors were significantly up regulated in (P<0.05) in all the stages and highest levels were observed in mid and late luteal stages consistent with in vivo luteinization of buffalo CL and declined coincidental to luteal regression. The expression of StAR, P450scc and HSD factors maintained low in early luteal phase, after that level of expression increased steadily to show a significant rise (P<0.05) in mid luteal phase followed by gradual decline in late luteal phase and regressed CL and this correlates well with the Ob and ObR receptor activity, verifying their key role in progesterone and other steroids production in functional CL. As revealed by immunohistochemistry, leptin protein was localized predominantly in large luteal cells however leptin receptor (Ob-R) was localized in large luteal cells as well as in endothelial cells. It can be concluded from our study that leptin via its autocrine/paracrine effects play a significant role in promoting angiogenesis, steroidogenesis and also acts as key survival factor in bubaline CL.Not Availabl