Fundamentals of Large Sensor Networks: Connectivity, Capacity, Clocks and Computation

Sensor networks potentially feature large numbers of nodes that can sense their environment over time, communicate with each other over a wireless network, and process information. They differ from data networks in that the network as a whole may be designed for a specific application. We study the theoretical foundations of such large scale sensor networks, addressing four fundamental issues- connectivity, capacity, clocks and function computation. To begin with, a sensor network must be connected so that information can indeed be exchanged between nodes. The connectivity graph of an ad-hoc network is modeled as a random graph and the critical range for asymptotic connectivity is determined, as well as the critical number of neighbors that a node needs to connect to. Next, given connectivity, we address the issue of how much data can be transported over the sensor network. We present fundamental bounds on capacity under several models, as well as architectural implications for how wireless communication should be organized. Temporal information is important both for the applications of sensor networks as well as their operation.We present fundamental bounds on the synchronizability of clocks in networks, and also present and analyze algorithms for clock synchronization. Finally we turn to the issue of gathering relevant information, that sensor networks are designed to do. One needs to study optimal strategies for in-network aggregation of data, in order to reliably compute a composite function of sensor measurements, as well as the complexity of doing so. We address the issue of how such computation can be performed efficiently in a sensor network and the algorithms for doing so, for some classes of functions.Comment: 10 pages, 3 figures, Submitted to the Proceedings of the IEE

A study of the correlation of serum vitamin D levels to Child-Pugh and MELD-Na scoring system in cirrhosis of the liver

Background: Vitamin D is a hormone with known effect on calcium homeostasis, but recently there is increasing recognition that it also is involved in cell proliferation and differentiation, has immunomodulatory and anti-inflammatory properties. These effect may explain its importance in the liver diseases. Vitamin D deficiency has been reported highly prevalent in Chronic liver disease (CLD) and there is an emerging interest to explore the relationship of vitamin D deficiency and severity of CLD. The aim of the study was to evaluate the correlation of serum vitamin D levels to the Child Pugh and MELD-Na scoring system in liver cirrhosis and to establish its relationship with the severity of the disease.Methods: Serum vitamin D levels were measured in 100 patients of CLD and 100 healthy controls. The degree of liver dysfunction was estimated by Child-Pugh and MELD-Na scores.Results: 91% of the CLD patients had subnormal vitamin-D levels. The mean vitamin D level in CLD patients was lower (15.97±7.45) than controls (30.12±6.60) with statistical significance (p= 0.0001). On linear regression vitamin D level showed significant negative correlation with Child Pugh score (r= –0.446, p<0.001) and MELD score (r= –0.395, p<0.001). Low vitamin D level was associated with poor outcome (mean vitamin D level 9.61±3.01 who died versus 16.52±7.47 who survived and discharged).Conclusions: CLD is associated with a significantly low level of vitamin D. The lower level of vitamin D is associated with severity of CLD, mortality and increased risk for complications. Awareness of serum vitamin D level in CLD patients is important to improve outcome

A partner monoclonal antibody to Moab 730 kills 100% of DU145 and PC3 androgen-independent cancer cells

A number of therapeutic options are available for patients with prostate carcinoma till the time that the tumour is hormone dependent. However, no fully effective therapy is available for the treatment of androgen-independent prostate carcinomas. Antibodies directed at epitopes unique to or overexpressed on the cancer cells could be of therapeutic utility. A monoclonal antibody (Moab) 2C4 has been generated, which binds with cells of two androgenin-dependent prostate cancers, DU145 and PC3, and does not bind to peripheral blood leukocytes (PBLs) of healthy donors. This antibody, along with the previously developed Moab 730, kills 100% of both DU145 and PC3 cells in the presence of complement and does not have a deleterious effect on PBLs of healthy males. The anti-tumour action of the two antibodies prevents the establishment of DU145 cell tumour in nude mice in vivo. Moab 2C4 in combination with 730 has potential for use as therapy for androgen-independent cancers

QUALITY CHARACTERIZATION OF MADHUYASHTI GHRITA

Madhuyashti Ghrita, is an Ayurvedic medicated ghee preparation containing Yashtimadhu. It is used for treating external ulcers and wounds in vital points of the body. However, there is no quality monograph available for Madhuyashti Ghrita. Hence, the present work was carried out to characterize this Ghrita to confirm its identity, quality and purity. This work reported various pharmacognostic and physicochemical parameters of Madhuyashti Ghrita along with its TLC based rapid fingerprinting as per the present standards of Ayurvedic Pharmacopoeia of India. Moreover, the presence of toxic contaminants like heavy metals, and microbial load were also evaluated. In organoleptic evaluation, the Ghrita was found to be semi–solid and dark yellow in colour, sweet and bitter in taste with a characteristic and pleasant odour. The values of the physicochemical parameters such as acid value, saponification value, peroxide value, refractive index, rancidity and pH value of the Ghrita were also assed. In the microscopical analysis of the rhizomes of Yashtimadhu, the presence of pitted vessels, fibres, prismatic crystals and starch grains were noted as a confirmation characteristic for the genuinely of this raw material in Madhuyashti Ghrita. The amount of heavy metals such arsenic, lead, mercury, cadmium, nickel, zinc, copper and chromium as well as total bacterial count and total fungal count were found to be much below their API limits. The TLC showed different characteristic spots indicating the presence of Yashtimadhu in this product. The parameters of Madhuyashti Ghrita presented in this paper may be utilized for preparing a quality monograph for this product