Understanding Gravity: Some Extra Dimensional Perspectives

Gravity is one of the most inexplicable forces of nature, controlling everything, from the expansion of the Universe to the ebb and flow of ocean tides. The search for the laws of motion and gravitation began more than two thousand years ago but still we do not have the complete picture of it. In this article, we have outlined how our understanding of gravity is changing drastically with time and how the previous explanations have shaped the most recent developments in the field like superstrings and braneworlds.Comment: 21 page

Plasmon Annihilation into Kaluza-Klein Graviton: New Astrophysical Constraints on Large Extra Dimensions

In large extra dimensional Kaluza-Klein (KK) scenario, where the usual Standard Model (SM) matter is confined to a 3+1-dimensional hypersurface called the 3-brane and gravity can propagate to the bulk (D=4+d, d being the number of extra spatial dimensions), the light graviton KK modes can be produced inside the supernova core due to the usual nucleon-nucleon bremstrahlung, electron-positron and photon-photon annihilations. This photon inside the supernova becomes plasmon due to the plasma effect. In this paper, we study the energy-loss rate of SN 1987A due to the KK gravitons produced from the plasmon-plasmon annihilation. We find that the SN 1987A cooling rate leads to the conservative bound $M\_D$ > 22.9 TeV and 1.38 TeV for the case of two and three space-like extra dimensions.Comment: 13 pages, 1 ps figure, text is modified a little bit, conclusion unchanged, new references are added, version accepted for publication in PR

First Record of Regular Sea Urchin Salmacis virgulata (L. Agassiz and Desor 1846) from the Pondicherry Coast, India

The paper reported the first record of Regular sea urchin Salmacis virgulata (L. Agassiz and Desor 1846) in the Pondicherry coast, India. Three adult specimens were found in Kalapet region of Pondicherry coast, India in May 2010. It is a characteristic organism of the Echinoderm fauna of the Bay of Bengal and the description of the organism are provide

Mangrove vegetation and community structure of brachyuran crabs as ecological indicators of Pondicherry coast, South east coast of India

Baseline ecological studies of Pondicherry mangroves are important for monitoring, management and conservation of mangrove ecosystems. A brachyuran crab faunal assemblage at four stations of Pondicherry mangroves is described and monthly samplings were made during September 2008 – August 2009. Totally 22 species of brachyuran crabs belonging to 12 genera and 5 families were recorded; crabs belonging to the family Portunidae and Ocipodidae are most dominant group represented by total of 16 species. Six species considered are as a commercially important and out of which, on three species Scylla serrata, Thalamitta crenata and Portunus sanguinolentus are catch large quantities from stations 1 and 2. Portunus pelagicus, P. sanguinolentus and T. crenata were totally absent in stations 3 and 4. Population densities of brachyuran fauna ranged from 29 -71 ind. m2, the diversity ranged from 0.96 -2.18 bit. ind -1, the richness varied from 0.42 -0.74, and the evenness varied from 0.41 -.072. Maximum diversity values were recorded during post monsoon. The crab community recorded was analyzed by univariate and multivariate statistical techniques. Crab community structure was correlated with vegetation structure, and environmental factors were positively correlated with surface water pH, salinity, tree dominance, tree diversity and tidal inundation and negatively correlated with sulphide, organic matter, senescent leaves and decaying leaves, suggesting that the mangrove vegetation is important to the crab fauna as a habitat and food supply

Influence of Environmental Parameters on the Distribution and Diversity of Molluscan Composition in Pondicherry Mangroves, Southeast Coast of India

Seasonal variation in the distribution of mollusks in relation to environmental parameters was studied at four mangrove stations on the Pondicherry coast during September 2008-August 2009. A total of 37 species of molluscs were recorded, among them 16 species of bivalves belonging to 7 families and 12 Genera, and 21 species of gastropods belonging to 14 families and 19 Genera, with the Cereithedia cingulata being the dominant group. An increase of species density and diversity in the Post monsoon season was observed, with the highest values for both indexes at stations 1 and 2, and the lowest at stations 3 and 4 fine where the sand assemblage was dominated by a few gastropods. Pollution indicator species Cassidula nucleus, Melampus ceylonicus, Sphaerassiminea minuta were found only in highly polluted regions near stations 3 and 4; they were totally absent in moderately polluted areas near stations 1 and 2. From a stepwise multivariate analysis of the different environmental parameters regarding molluscan density, it was found that in all 10 parameters govern the density variation of benthic mollusks in Pondicherry mangroves and that the organic matter of sediment and sulphide, DO, and salinity were the highly significant ones

Ground Water Quality Assessment in Paper Mill Effluent Irrigated Area - Using Multivariate Statistical Analysis

Paper mill effluent while flowing, percolates through soil and slowly mixes with ground water bodies (Open well), water samples were collected from three stations (S1, S2 and S3) in and around paper mill. This paper represents the characteristics of ground water quality and the effect of paper mill effluent, which is using recycled water for irrigation and domestic purpose. Cluster analysis (CA), principal component analysis (PCA) and multidimensional scale plot (MDS) appear were employed to evaluate the tropic status of water quality for three monitoring stations. High pollution load was observed in the ground water bodies due to continuous flow of effluent near the ground water sources. Effluent water consists of 3400 mg/l suspended solids. However, pH varied from 5.5-7.6. The biochemical oxygen demand and chemical oxygen demand ranged from 2-780 and 60 - 1520 mg/l respectively. SAR, RSC and SSP level was high from S2 and S3, both were unsuitable for both domestic and irrigation purposes. An elevated coliform bacterial count indicates that these water samples S2 and S3 were not suitable for domestic purpose. The dendrogram of the effluent water quality parameters evidently indicate that Maruthi Paper mill does not meet nominal National standard set by central pollution control board to discharge in agricultural fiel

Identification of mangrove water quality by multivariate statistical analysis methods in Pondicherry coast, India

Different multivariate statistical analysis such as, cluster analysis, principal component analysis, and multidimensional scale plot were employed to evaluate the trophic status of water quality for four monitoring stations. The present study was carried out to determine the physicochemical parameters of water and sediment characteristics of Pondicherry mangroves— southeast coast of India, during September 2008– December 2010. Seasonal variations of different parameters investigated were as follows: salinity (10.26–35.20 psu), dissolved oxygen (3.71–5.33 mg/L), pH (7.05– 8.36), electrical conductivity (26.41–41.33 ms−1), sulfide (1.98–40.43 mg/L), sediment texture sand (39.54– 87.31%), silt (9.89–32.97%), clay (3.06–31.20%), and organic matter (0.94–4.64%). pH, temperature, salinity, sand, silt, clay, and organic matter indicated a correlation at P<0.01

Haematology and biochemical parameters of different feeding behaviour of teleost fishes from Vellar estuary, India

Haematological parameters have been recognized as valuable tools for monitoring fish health. Haematological and serum biochemical parameters were studied and compared different feeding behaviour of teleost fishes. Three marine teleost fishes, Lates calcarifer (carnivores), Mugil cephalus (omnivores) and Chanos chanos (herbivores), were carried out in order to find out a normal range of blood parameters which would serve as baseline data for assessment of the health status of the fish as well as reference point for future comparative surveys. Blood parameters such as red blood cell count (RBC) and white blood cells count (WBC), haemoglobin, haematocrit, mean cell haemoglobin concentration (MCHC), mean cell volume (MCV), mean cell haemoglobin, glucose, protein, cholesterol and urea were estimated from teleost fishes of different trophic level. Statistical analysis revealed that differences in haematological parameters between marine fish were significant (P<0.01)

Conservation of mangrove forest covers in Kochi coast

Mangroves are salt-tolerant plants of tropical and subtropical intertidal regions of the world. The specific regions where these plants occur are called mangrove ecosystems. They are breeding, feeding and nursery grounds for many estuarine and marine organisms, including finfish and shell fish. India has only 2.66% of the world’s mangroves, covering an estimated area of 4,827 sq. k

Comparative study of hematological and blood chemistry of Indian and Italian Grey Mullet (Mugil cephalus Linneaus 1758)

Blood hematological and serum biochemistry parameters are often used to assess the health status and as stress indicators in fishes. In the present study was undertaken to comparative study of hematological and blood chemistry of Indian and Italian Grey Mullet (Mugil cephalus) to establish baseline values. Fifteen sexually immature and disease-free Indian wild fish (26.25 ± 0.23 cm total length, 347.55±14.27 g weight) and 15 Italian fish (31.53 ± 1.08 cm total length, 416.5 ± 14.56 g weight) were examined