Finite-size Scaling Study of Shear Viscosity Anomaly at Liquid-Liquid Criticality

We study equilibrium dynamics of a symmetrical binary Lennard-Jones fluid mixture near its consolute criticality. Molecular dynamics simulation results for shear viscosity, $\eta$, from microcanonical ensemble are compared with those from canonical ensemble with various thermostats. It is observed that Nos\'{e}-Hoover thermostat is a good candidate for this purpose and so, is adopted for the quantification of critical singularity of $\eta$, to avoid temperature fluctuation (or even drift) that is often encountered in microcanonical simulations. Via finite-size scaling analysis of our simulation data, thus obtained, we have been able to quantify even the weakest anomaly, of all transport properties, that shear viscosity exhibits and confirm the corresponding theoretical prediction.Comment: 6 pages, 6 figure

Study of Critical Dynamics in Fluid via Molecular Dynamics in Canonical Ensemble

With the objective of demonstrating usefulness of thermostats in the study of dynamic critical phenomena in fluids, we present results for transport properties in a binary Lennard-Jones fluid that exhibits liquid-liquid phase transition. Results from the molecular dynamics simulations in canonical ensemble, with various thermostats, are compared with those from microcanonical ensemble. It is observed that the Nos\'{e}-Hoover and dissipative particle dynamics thermostats are useful for the calculations of mutual diffusivity and shear viscosity. The Nos\'{e}-Hoover thermostat, however, appears inadequate for the study of bulk viscosity.Comment: 5 pages, 4 figures in European Physical Journal E 201

Some remarks on two-periodic modules over local rings

In this note, some properties of finitely generated two-periodic modules over commutative Noetherian local rings have been studied. We prove a weaker version of the Huneke-Wiegand conjecture for two-periodic modules -- under certain assumptions, a two-periodic module is necessarily free. Given a two-periodic module with finite rank over a one-dimensional local ring, it is shown that the tensor product of the module with its dual has non-zero torsion. Moreover, if the base ring is one-dimensional, we show that with certain assumptions on modules, the tensor product of a two-periodic module with another finitely generated module is torsion-free if and only if the pair of modules is Tor-independent. We also discuss Auslander's depth formula for a Tor-independent pair of modules in this setup. It is proved that such a formula holds for a Tor-independent pair of modules if one of the modules is two-periodic with finite Gorenstein dimension.Comment: 11 pages. Comments are welcom

Assessing the Need of Adaptive Changes for Emerging NORCs in Urban India

Due to population ageing, today’s high-rise apartments in Indian cities, which are currently mainly owned by young professionals, will turn into naturally occurring retirement communities (NORCs) in near future. Though many urban housing complexes of 1970s and 1980s are already serving as NORCs, the term is comparatively new to Indian housing research. This huge existing housing stock is inadequate for special gerontological needs of the elderly, who are fragile and socially vulnerable. Informal opinion of common people revealed that holistic requirement for elderly in housing is still grossly confused with vertical transport, i.e., elevators, and little attention is paid to other architectural features. As part of an ongoing doctoral study, a detailed literature review was undertaken on the vulnerability profile of Indian urban elderly in the context of special requirements of barrier-free housing. This article aims to establish the urgent need to assess the adaptive potential of existing housing communities serving as NORCs in Indian cities, such that new housing in the future can be planned with flexible approach

DESIGN OF DISSOLUTION STUDY PROTOCOL FOR PULMONARY DOSAGE FORMS: CRITERIA FOR SELECTION OF BIO-RELEVANT DISSOLUTION MEDIUM

Pulmonary dosage forms constitute an important route of drug delivery for systemic absorption of drugs in management of respiratory diseases as well as diseases such as diabetes, migraine, osteoporosis, and cancer. Performance of different pulmonary dosage forms is greatly influenced by aerodynamic particle size distribution of inhalable particles, spray pattern, fraction of dose actually deposited on pulmonary epithelium, dissolution of active pharmaceutical ingredient and ultimately absorption across pulmonary barriers. In vitro dissolution study should be designed to predict in vivo performance precisely, providing key information on bioavailability and establishing in vitro-in vivo correlation. To obtain meaningful data from dissolution study, focus should be on composition of dissolution medium, dissolution conditions and dissolution test apparatus. For pulmonary dosage forms, selection of physiologically relevant dissolution medium, mimicking lung fluid (LF) is a challenging task. Attempts are being made to develop bio-relevant dissolution medium to overcome the limitations associated with use of conventional media lacking lung surfactant proteins, or several salts normally present in pleural fluid. Use of simulated LFs can give a better understanding of the release mechanisms and possible in vivo behavior of pulmonary dosage forms thereby enhancing the predictive capability of the dissolution testing. In the review, efforts have been taken to provide comprehensive information on composition, physicochemical characteristics and functions of physiological LF, challenges associated with the design and development of dissolution study protocol for pulmonary dosage forms, criteria for selection of an appropriate bio-relevant dissolution medium, comparative study on various reported bio-relevant dissolution media and dissolution apparatuses employed for in vitro characterization of performance of pulmonary dosage forms

Expression of Mn-Superoxide Dismutase Gene in Nontumorigenic and Tumorigenic Human Mammary Epithelial Cells

Manganese superoxide dismutase (Mn-SOD), localized at the mitochondrial matrix, has the ability to protect cells against oxidative damage. It has been reported that low levels of Mn-SOD gene expression cause the development of certain kind of tumors. On the other hand, overexpression of Mn-SOD gene may play an important role in the development of cancer. In our study, we find that Mn-SOD activity was higher in nonaggressive (MCF-7) and aggressive (BT-549 and 11-9-14) breast cancer cell lines compared to that of nontumorigenic (MCF-12A and MCF-12F) mammary epithelial cell lines. We also observed an increased expression of Mn-SOD gene in cancerous cell lines. The elevated level of SOD activity in nonaggressive and aggressive breast epithelial cell lines was associated with some changes in nucleotide sequence

MGNREGA And Water Management: Sustainability Issues Of Built Forms In Rural India

Compared to urban sustainability, rural sustainability has traditionally received inadequate attention, especially in developing countries such as India. Because of their symbiotic relation with the local climate and landforms, vernacular structures of rural India are said to be inherently sustainable. However, since 2005, substantial amounts of intervention brought about by the Mahatma Gandhi National Rural Employment Generation Act (MGNREGA) have changed this situation. India's rural landscape is now intersected with numerous built forms, such as road networks, water management systems, and land development. Unfortunately, the MGNREGA's goal of addressing the substantial void that characterised rural areas and bringing about a sustainable future through the generation of the multiplier effect have not been achieved in most cases. This study was conducted to investigate the reasons for this unexpected outcome. Water management, constituting the major thrust of the MGNREGA, was examined for two purposively selected areas with distinctively different physio-climatological variations at the micro level from the state of West Bengal. The data from the MGNREGA website and from field investigations show a short-term benefit, whereas sustainability issues on a long-term basis remain a concern. Straightjacketed norms for scheme implementation ignoring physical heterogeneity across the country appear to be a major cause. Reframing and customisation of construction specifications are recommended as a solution