On Products and Line Graphs of Signed Graphs, their Eigenvalues and Energy

In this article we examine the adjacency and Laplacian matrices and their eigenvalues and energies of the general product (non-complete extended $p$-sum, or NEPS) of signed graphs. We express the adjacency matrix of the product in terms of the Kronecker matrix product and the eigenvalues and energy of the product in terms of those of the factor signed graphs. For the Cartesian product we characterize balance and compute expressions for the Laplacian eigenvalues and Laplacian energy. We give exact results for those signed planar, cylindrical and toroidal grids which are Cartesian products of signed paths and cycles. We also treat the eigenvalues and energy of the line graphs of signed graphs, and the Laplacian eigenvalues and Laplacian energy in the regular case, with application to the line graphs of signed grids that are Cartesian products and to the line graphs of all-positive and all-negative complete graphs.Comment: 30 page

CYTOTOXICITY OF PUNARNAVA (BOERHAAVIA DIFFUSA L.) IN BREAST CELL LINE

The incidence of cancer especially breast cancer is increasing alarmingly worldwide with a high percentage of death especially in developing countries. The Ayurvedic system treasures a host of medicinal formulations that have been shown to possess cytotoxic effects on tumor cell lines. Recently herbal medicines are coming to play a more vital role in the reduction and prevention of cancer. Boerhaavia diffusa L. (Punarnava), an annual herb has been used for managing wide range of diseases including cancer. This herb was also screened for various pharmacological activities like anti-inflammatory, anti-oxidant, immunomodulatory, anti-angiogenic, anti-metastatic activities and others. The decoction of root of Boerhaavia diffusa L. (Punarnava) was not scientifically evaluated for cytotoxicity. So the current study investigates the In vitro Cytotoxicity of root of decoction of Punarnava (Boerhaavia diffusa L.) in breast cell line (MCF-7). The five different concentrations of decoction of Punarnava (Boerhaavia diffusa Linn.) were used for In vitro Cytotoxicity by MTT assay at 24 hours and 48 hours. The test sample exhibits cytotoxicity of about 65.1±1.2at 800 µg/ ml concentration (48 hours) of incubation in MCF-7 breast cell line. The results were also analyzed statistically. It showed that there is highly significant difference in the percentage of inhibition of test sample in concentration from 50µg/ml -800µg/ml. The findings of this investigation concluded that the study drug Boerhaavia diffusa L. (Punarnava) has anti-cancer activity in MCF-7 breast cell line

Vector Valued Switching in Signed Graphs

A signed graph is a graph with edges marked positive and negative; it is unbalanced if some cycle has negative sign product. We introduce the concept of vector valued switching function in signed graphs, which extends the concept of switching to higher dimensions. Using this concept, we define balancing dimension and strong balancing dimension for a signed graph, which can be used for a new classification of degree of imbalance of unbalanced signed graphs. We provide bounds for the balancing and strong balancing dimensions, and calculate these dimensions for some classes of signed graphs.Comment: 15 pp., 5 figs. V2 12 pp., 4 figs., more data, slightly shorte

A note on an unusual occurrence of Horse Mackerel Megalaspis Cordyla (Linnaeus) in the Kovalam Bay, Madras

A report on an unusual landing of Horse Mackerel Megalaspis cordyla, observed in the shore-seine catches from the Kovalam bay on 4th February, 1986

A Review on Transport Modeling Of VOCs In Subsoil

ABSTRACT: Volatile Organic Compounds (VOCs) are the most common subsurface environment contaminants usually in the form of Non-Aqueous Phase Liquids (NAPL) through Leaking Underground Storage Tanks (LUSTs) and pipelines, accidental spills, land disposal sites, and industrial waste impoundments. VOCs are toxic, mutagenic and carcinogenic. Hence, VOCs in subsoil pose a serious threat of groundwater contamination. Organic compounds, owing to their persistence and volatility, present unique environmental problems in the vadose zone of soils. The uncertainty in transport mechanisms and subsoil environment pose a serious challenge in developing transport model for VOC compounds. Apart from advection and dispersion, VOC also undergo several complex chemical reactions such as adsorption, degradation, volatilization and ionic exchange. The transport mechanisms and transport modeling studies for VOCs are largely based on extensive field studies and relevant laboratory experiments. The focus here is to review the role of transport mechanisms and modeling aspects of organic compounds in petroleum fuels and other such liquids and liquid wastes that have the potential to migrate through subsoil to groundwater and also to atmosphere by vapor diffusion

Incidence of pseudohermaphroditism in the spiny lobster Panulirus homarus (linnaeus)

Specimens of the spiny lobster, Panulirus homarus ranging in size from 22.3 - 97.5 mm carapace length (67 - 245 mm total length) with well developed male genital system, but with biramous pleojxxls (as in females) were recorded in 1987,1988 and 1989 from trammel net catches off Kovalam, near Madras. The probable factors responsible for this sexual abnormality have been discussed