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

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

Puducherry mangroves under sewage pollution threat need conservation

Indian mangroves have a rich diversity of soil-dwelling organisms which include micro, meio and macro forms. Mangrove ecosystem provides an ideal nursery and breeding ground for most of the marine and brackish water fish and shellfish. India has only 2.66% of the world’s mangroves1, covering an estimated area of 4827 sq. km. The present study area lies within the margins of lat. 11°90′107″– 11°90′703″N and long. 79°80′547″– 79°81′851″E. Mangrove exists as fringing vegetation over 168 ha distributed along the sides of Ariankuppam estuary, which empties into the Bay of Bengal (Coromandal coast) at Veerampatinam on the southeastern coast of Indi

Checklist and Spatial Distribution of Molluscan Fauna in Minicoy Island, Lakshadweep, India

Among the various animal groups represented in the macrobenthic fauna of Minicoy lagoon studied, mollusks were the dominant group. Molluscan fauna were investigated from six selected stations in the sea grass beds and mangroves of the Minicoy lagoon, Lakshadweep during 1999-2001. A total of 70 species of mollusk (52 gastropods, 12 bivalves) and an additionally 7 soft mollusks are reported in the present study. The total density of molluscan fauna varied from 137-604 (no. 0.25m2), while the highest biomass was obtained during postmonsoon season at southern seagrass bed and the least was observed during premonsoon season at northern seagrass bed. Among these Gafrarium divarticatum, Terebralia palustris are found the most dominant species of Minicoy Island, India

New Polychaete Records from Seagrass Beds at Minicoy Island, Lakshadweep, India

Species composition, distribution and taxonomic description of polychaete fauna in the seagrass beds of the Minicoy lagoon, Lakshadweep, India were studied during 1999 - 2001. In 4 stations, 27 species of polychaetes belonging to 14 genera were identified. Of these 27 species, 10 species of polychaetes, belonging to 8 genera under 6 families, comprise new distributional records from Minicoy Island, and the descriptions of these species are provided. Among these, Glycera lancadivae, G. tesselata, and Eurythoe matthaii are found to be the most dominant species

Antioxidant and anti-proliferative activity of different solvent extracts of Casuarina equisetifolia needles

The context and purpose of the study: Plants that have been used for traditional medicines are very good sources of phyotochemicals. There are many plants like Casuarina equisetifolia, which are still unexplored for their medicinal properties. In the present study, we have elucidated the in vitro antioxidant and antiproliferative activity of different solvent extracts (both polar and non polar) of C. equisetifolia needles.Main findings: In vitro antioxidant activity of different solvent extracts of C. equisetifolia needles was studied by analyzing the total polyphenols, flavonoids, total antioxidant capacity and free radical scavenging activity. The polar solvent extracts showed significantly high amount total polyphenols, flavonoids, antioxidants and free radical scavenging activity compared to the non polar solvent extracts. The cytotoxic and apoptosis inducing activity of the different solvent extracts were analyzed on MCF-7 cells by MTT assay, acridine orange/ethidium bromide staining, DAPI staining and caspase-3 release. The polar solvent extracts did not show any growth inhibition in MCF-7 cancer cells. But the non polar solvent extracts are very good in inducing cell death by inducing apoptosis which involves DNA fragmentation and release of caspase 3. Using silica gel fractionation and RP-HPLC analysis the active component present in non-polar solvent extracts was identified as ascorbic acid.Brief summary and potential implications: Our results indicated that the needles of C. equisetifolia are rich sources of antioxidants and also contain potential anticancer agents. Detailed study on the mechanism of action of purified compound on inhibition of cancer cell growth may provide some potential anticancer molecule from natural source

Soil temperature prediction based on ensemble tree bagger machine learning algorithm for agricultural decision making

This study focuses on predicting surface soil temperature (ST) at a 5 cm depth, which significantly influences agricultural decisions such as sowing time, irrigation management and soil-plant-atmosphere dynamics. Machine learning (ML) algorithms were used to predict ST using above-ground weather variables viz., air temperature (T), relative humidity (RH), wind velocity (WV) and sunshine duration (SS) measured at 15-min intervals. Six regression-based ML models (Ensemble, Gaussian Process Regression, Support Vector Machine, Tree, Neural Network and Kernel) were trained and tested for predictive accuracy. The Ensemble Bagging Tree model showed the highest precision, with RMSE values of 2.04 and 1.9 for validation and testing, respectively. Various combinations of the weather variables were tested and the model performed best when using above mentioned variables. Among the predictors, T had the greatest impact on ST prediction, as indicated by mean absolute Shapley values. The Shapley values of the variables revealed that T had a critical role in the model output, with time, SS, RH and WV following in importance. Additionally, as a model explainable artificial intelligence (xAI) metrics, SHapley Additive exPlanations (SHAP) were analysed and found that SHAP dependency had a defined relationship between the predictors and ST at a 5 cm depth. This study highlights the effectiveness of machine learning in predicting soil temperature and emphasizes the role of weather variables in agricultural decision-making. decision-making

Human milk banking: One year experience from a tertiary care centre

Introduction: A human milk bank (HMB) systematically collects, screens, processes, and dispenses excess milk donated by healthy nursing mothers. First HMB of Asia was established in the year 1989 in Mumbai, but there are still insufficient milk banks in India. Objective: This study aimed to provide our experience in the past 1 year. Methods: This retrospective descriptive study was conducted in the HMB of a tertiary care institution. The data were collected from donor forms and other milk bank records in the milk bank. All the demographic details and bacteriological data were collected. Results: There were 1168 donors with no extramural donors. Of these, 882 donors had term babies and 286 had preterm babies. The mean age of the donor population was 23.53±3.27 years. On the analysis of the volume of milk donated, the mean volume was 77.62±51.26 ml. A total of 90,660 ml of human milk was collected during the study period of 1 year. The bacteriological culture of the donor milk showed growth in 42 (3.6%) samples and was discarded. Klebsiella (2.39%) was the most common organism followed by Escherichia coli (0.44%) and Staphylococcus (0.35%). There were 1424 recipients and about 74% of them, were preterm babies. There were no extramural recipients. Conclusion: For a large number of preterm babies and the neonates without breast milk in India, pasteurized donor human milk will be the best source of nutrition. Hence, number of HMBs will improve the neonatal survival and reduce the morbidity