1,325 research outputs found
Spinodal decomposition in the inverse cascade of two-dimensional, binary-fluid turbulence
No full textWe study spinodal decomposition in the inverse-cascade regime of two dimensional turbulence in symmetric, binary fluid mixtures. We show that turbulence leads to break up of domains whose size, in the inverse cascade regime, is proportional to the Hinze scale. Even more strikingly, we show that the inverse cascade of energy is blocked by the formation of domains
Multifractal Droplet Dynamics in Two-Dimensional, binary-fluid turbulence
No full textWe present the most extensive direct numerical simulations, attempted so far, of statistically steady, homogeneous, isotropic turbulence in two-dimensional, binary-fluid mixtures with air-drag-induced friction. We model this mixture by using the Cahn-Hilliard-Navier-Stokes equations and choose parameters, e.g., the surface tension, such that we have a droplet of the minority phase moving inside a turbulent background of the majority phase. Our study reveals that a single droplet, whose mean radius lies in the inertial range of scales, (a) enhances the the forward-cascade part of the energy spectrum of two-dimensional turbulence and (b) stretches the tails of the PDF of the Okubo-Weiss parameter . We show that the dynamics of the droplet is affected significantly by the turbulence in the fluid. In particular, the PDFs of the components of the acceleration shows wide, non-Guassian tails. We characterize the time dependence of the deformation of the droplet and show that it exhibits multifractality
Utilizzo dell’anticorpo chimerico marcato con 124-I nella diagnosi pre-chirurgica del tumore renale a cellule chiare in pazienti con masse renali operabili.
No full textStructural Modelling Under Challenge
No full textOver the last two decades or so macroeconometric modelling which was in vogue over the sixties and the seventies has ceased to be high on the academic agenda. This has been for a number of developments in macroeconomic theory and in econometric methodology. At the same time it is by no means true that macroeconometric modelling in the Cowles Commission tradition has been given up. Like all healthy disciplines the subject has incorporated some of the new developments and rejected some. Structural models continue to be used for policy formulation and continue to be used for policy formulation and evaluation all over the world because no viable alternative has emerged so far. This paper is intended to take stock of the prevailing situation and to suggest the course that the subject is likely to take in the years to come.
PUBLIC INVESTMENT IN AGRICULTURAL AND GDP GROWTH-- ANOTHER LOOK AT THE INTER SECTORAL LINKAGES AND POLICY IMPLICATIONS
No full textDespite its reduced share in India’s GDP, agriculture continues to have a strategic importance in ensuring its overall growth and prosperity. As part of the new economic policy package introduced in the early nineties, there has been a reduction in the rate of public investment. While this may not be bad for the industrial sector, the impact of this policy on agriculture is a matter of concern, in sofar as it not only affects steady growth of agriculture but also influences the overall performance of the economy. This is more so because the agricultural sector public investment has also promoted private investment by way of what is termed as the crowding-in phenomenon. This phenomenon together with inter-sectoral linkages is used in this paper to examine the effect of higher public investment for agriculture on the stable growth of this sector as well as of the entire economy. Policy implications of this exercise are important for obvious reasons.Sectoral linkages, Public Investment, crowding-in
Mercury enrichment and Hg isotopes in Cretaceous-Paleogene boundary successions: Links to volcanism and palaeoenvironmental impacts
No full textWe investigate the use of Hg as a proxy for volcanism by studying four distal and two proximal sections in relation to the Deccan volcanic center, straddling the Cretaceous-Paleogene (KPg) boundary at (a) Højerup (Denmark), Bottaccione and Padriciano (Italy), (b) Meghalaya and Jhilmili (India), and (c) Bajada del Jagüel (Argentina). Hg sequestration by organic matter results in constant Hg/TOC ratio and linear correlation between Hg content of the sediments and total organic carbon (TOC).Elevated Hg concentrations that deviate from this linear relationship represent most likely true Hg anomalies and these notable Hg/TOC spikes (all TOC <1%) are found in the Meghalaya, Bottaccione and Højerup sections within the CF2 planktic foraminiferal biozone (spike I), at the KPg boundary (spike II), and within the P1a planktic foraminiferal subzone (spike III). Spike III occurs also in the Jhilmili section. No clear correlation between Hg/TOC and Al2O3 exists in any of the studied sections. The Hg anomalies probably result from strong volcanic episodes of the Deccan phase-2 (started 250 kyr before the KPg boundary and lasted for 750 kyr) that exhaled sulfuric aerosols, carbon dioxide and other toxic agents which reached a critical threshold, represented in true Hg enrichments in the paleoenvironments. The possibility that Hg enrichments resulted from anoxia scavenging on the seafloor and penetration downward into sediments is not supported in the stratigraphic record of Mo/Al ratios redox proxy.Hg isotopes were analyzed in samples from all KPg boundary sections in this study and from Bidart, France, the latter for comparison. Hg isotopes yielded δ202Hg values ranging from -1 to -2‰ and δ201Hg signatures from 0 to 0.05‰ (spike II in Højerup, Bottaccione and Meghalaya KPg boundary layers) consistent with volcanic emission of Hg (0 to -2‰). The δ202Hg in spike I in Meghalaya and Padriciano and spike III in Jhilmili is consistent with volcanic emission of Hg. Two samples from Bajada del Jagüel and four from Bidart, however, display isotope signals compatible with volcanic emission/chondrite Hg. The results of three other samples are characteristic for reworked sediment, soil and/or peat. Most of the data show small positive Δ201Hg, in favor of long-term atmospheric transport prior to deposition, supporting a volcanic origin for the Hg. The present study broadens, therefore, the potential use of Hg as stratigraphic marker and, moreover, confirms that in the critical KPg transition, Hg was enriched in paleoenvironments at three distinct stages during the Deccan phase-2.Fil: Sial, A. N.. Universidade Federal de Pernambuco; BrasilFil: Chen, Jiubin. Chinese Academy of Sciences; República de ChinaFil: Lacerda, L. D.. Universidade Federal do Ceará; BrasilFil: Frei, R.. Universidad de Copenhagen; DinamarcaFil: Tewari, V. C.. Sikkim University; IndiaFil: Pandit, M. K.. Rajasthan University; IndiaFil: Gaucher, C.. Universidad de la República. Facultad de Ciencias; UruguayFil: Ferreira, V. P.. Universidade Federal de Pernambuco; BrasilFil: Cirilli, S.. Università di Perugia; ItaliaFil: Peralta, Silvio Heriberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Centro de Investigaciones de la Geosfera y Biosfera. Universidad Nacional de San Juan. Facultad de Ciencias Exactas Físicas y Naturales. Centro de Investigaciones de la Geosfera y Biosfera; ArgentinaFil: Korte, C.. Universidad de Copenhagen; DinamarcaFil: Barbosa, J. A.. Universidade Federal de Pernambuco; BrasilFil: Pereira, N. S.. Universidade do Estado da Bahia; Brasi
Pilot study of iodine-124 labeled chimeric G250 (124I-cG250) in the presurgical diagnosis of clear cell-type renal carcinoma in patients with operable renal masses.
No full textEvaluation of multifunctional polysaccharide hydrogels with varying stiffness for bone tissue engineering
No full textThe use of hydrogels for bone regeneration has been limited due to their inherent low modulus to support cell adhesion and proliferation as well as their susceptibility to bacterial infections at the wound site. To overcome these limitations, we evaluated multifunctional polysaccharide hydrogels of varying stiffness to obtain the optimum stiffness at which the gels (1) induce proliferation of human dermal fibroblasts, human umbilical vascular endothelial cells (HUVECs), and murine preosteoblasts (MC3T3-E1), (2) induce osteoblast differentiation and mineralization, and (3) exhibit an antibacterial activity. Rheological studies demonstrated that the stiffness of hydrogels made of a polysaccharide blend of methylcellulose, chitosan, and agarose was increased by crosslinking the chitosan component to different extents with increasing amounts of genipin. The gelation time decreased (from 210 to 60 min) with increasing genipin concentrations. Proliferation of HUVECs decreased by 10.7 times with increasing gel stiffness, in contrast to fibroblasts and osteoblasts, where it increased with gel stiffness by 6.37 and 7.8 times, respectively. At day 14 up to day 24, osteoblast expression of differentiation markers - osteocalcin, osteopontin - and early mineralization marker - alkaline phosphatase, were significantly enhanced in the 0.5% (w/v) crosslinked gel, which also demonstrated enhanced mineralization by day 25. The antibacterial efficacy of the hydrogels decreased with the increasing degree of crosslinking as demonstrated by biofilm formation experiments, but gels crosslinked with 0.5% (w/v) genipin still demonstrated significant bacterial inhibition. Based on these results, gels crosslinked with 0.5% (w/v) genipin, where 33% of available groups on chitosan were crosslinked, exhibited a stiffness of 502±64.5 Pa and demonstrated the optimal characteristics to support bone regeneration. © Mary Ann Liebert, Inc
Altered excitation-contraction coupling in human chronic atrial fibrillation
No full textThis review focuses on the (mal)adaptive processes in atrial excitation-contraction coupling occurring in patients with chronic atrial fibrillation. Cellular remodeling includes shortening of the atrial action potential duration and effective refractory period, depressed intracellular Ca<sup>2+</sup> transient, and reduced myocyte contractility. Here we summarize the current knowledge of the ionic bases underlying these changes. Understanding the molecular mechanisms of excitation-contraction-coupling remodeling in the fibrillating human atria is important to identify new potential targets for AF therapy
Sustainable Economic Growth for India: An Exercise in Macroeconomic Scenario Building
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