46 research outputs found

    Coastal Vulnerability Assessment for Eastern Coast of India, Andhra Pradesh by Using Geo-Spatial Technique

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    The study mainly deals with the physical vulnerability of eastern coast India, Andhra Pradesh. It is one of the Indian states which have a very vast coastal line. Andhra Pradesh is very important to the whole economy, Vishakhapatnam is a major port situated in the eastern coast of India. Andhra Pradesh coastal line about 972 Km long, is affected by Storm surge, Cyclone, Sea Level Rise and Tsunami, etc. The method adopted for identifying the coastal vulnerability mapping was Coastal Vulnerability Index (CVI). Seven parameters were used for identifying Costal Vulnerability mapping which are Historical Shoreline changes, Mean Sea Level Rice, Significance of Wave Height, Mean Tide Range, Coastal Regional Elevation, Coastal Slope and Geomorphology. The final results of this study are in the form of a coastal vulnerability map which shows the environmentally vulnerable areas. This map will give general idea about the probability of an area to undergo coastal hazards due to coastal erosion or sea level rise. According to this study about 16% area of the coast of Andhra Pradesh is identified to have high vulnerability which can harm the environment. The map prepared of the Andhra coast under this study can be used by the state and district administration involved in the disaster mitigation and management plan

    Coastal Multi-hazard vulnerability mapping: A case study along the coast of Nellore District, East Coast of India

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    The study area coastal zone of Nellore district is experiencing frequent inundation by natural disasters. The current study is focused on generating Multi-hazard vulnerability map using the parameters historical storm surge heights, future sea level, future shoreline and high resolution coastal topography. The area is experiencing the severe coastal erosion up to 7 m/y along some stretches poses a threat. An area totaling 1708.36 sq. km. is found to fall under the multi-hazard zone and the coastal population are under threat due to future storms, erosion, accelerated sea level rise, etc. The image enhancement, interpretation and GIS overlay techniques along with data used here are effective to produce Multi-hazard vulnerability maps. These Maps are become vital tools for the coastal disaster management during an event and to take suitable decision on the future developments

    The admissible tsunamigenic source region of 24 September 2013 land-based earthquake application of backward ray tracing technique

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    A minor tsunami of about 50 cm was generated along the coast of Qurayat near Makran subduction zone in the Arabian Sea due to the 24 September 2013 Pakistan earthquake of magnitude 7.6 Mw(mB),although its source was ~200 km far inland of the Makran trench. The real time sea level observation network in the Arabian Sea recorded minor tsunami arrivals. In an attempt to explain the mechanism of this unusual tsunami, we use backward ray tracing technique to map the admissible region of tsunamigenic source. Basically, in this technique the ray equations are integrated starting from the specific locations of tsunami observations, in all possible directions. The known travel time of the initial waves to the respective tide gauges and tsunami buoys is used in this method. Backward wave front is constructed by joining all endpoints of the rays from each of the locations. The region where the envelope of all backward wave fronts converges is considered as the source of the tsunami, which is ~470 km from the earthquake epicentre with the location at 24.8 N and 61.5E. The admissible region identified is an undersea section between Chabahar and Gwadar, where a mud island had appeared subsequent to this earthquake. Convergence of the tsunami source zone and location of the mud island suggest that the sudden uplift must have caused the tsunam

    Comparative Skull Morphology of Uropeltid Snakes (Alethinophidia: Uropeltidae) with Special Reference to Disarticulated Elements and Variation

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    Uropeltids form a diverse clade of highly derived, fossorial snakes that, because of their phylogenetic position among other alethinophidian lineages, may play a key role in understanding the early evolution of cranial morphology in snakes. We include detailed osteological descriptions of crania and mandibles for eight uropeltid species from three nominal genera (Uropeltis, Rhinophis, and Brachyophidium) and emphasize disarticulated elements and the impact of intraspecific variation on previously proposed morphological characters used for phylogenetic analysis. Preliminary analysis of phylogenetic relationships strongly supports a clade composed exclusively of species of Plectrurus, Uropeltis, and Rhinophis. However, monophyly of each of those genera and Melanophidium is not upheld. There is moderate support that Sri Lankan species (e.g., Rhinophis and Uropeltis melanogaster) are monophyletic with respect to Indian uropeltids. Previously proposed characters that are phylogenetically informative include the shape of the nasals, length of the occipital condyle, level of development of the posteroventral process of the dentary, and participation of the parietal in the optic foramen. Additionally, thirty new features that may be systematically informative are identified and described, but were not verified for their utility. Such verification must await availability of additional disarticulated cranial material from a larger sample of taxa. All characters require further testing through increased focus on sources and patterns of intraspecific variation, inclusion of broader taxonomic samples in comparative studies, and exploration of skeletal development, sexual dimorphism, and biogeographic patterns. Additionally, trends in the relative enlargement of the sensory capsules, reduction in cranial ossification and dentition, fusion of elements, and the appearance of novel morphological conditions, such as the structure and location of the suspensorium, may be related to fossoriality and miniaturization in some uropeltid taxa, and may complicate analysis of relationships within Uropeltidae and among alethinophidian snakes

    Identification by Automated Screening of a Small Molecule that Selectively Eliminates Neural Stem Cells Derived from hESCs but Not Dopamine Neurons

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    BACKGROUND:We have previously described fundamental differences in the biology of stem cells as compared to other dividing cell populations. We reasoned therefore that a differential screen using US Food and Drug Administration (FDA)-approved compounds may identify either selective survival factors or specific toxins and may be useful for the therapeutically-driven manufacturing of cells in vitro and possibly in vivo. METHODOLOGY/PRINCIPAL FINDINGS:In this study we report on optimized methods for feeder-free culture of hESCs and hESC-derived neural stem cells (NSCs) to facilitate automated screening. We show that we are able to measure ATP as an indicator of metabolic activity in an automated screening assay. With this optimized platform we screened a collection of FDA-approved drugs to identify compounds that have differential toxicity to hESCs and their neural derivatives. Nine compounds were identified to be specifically toxic for NSCs to a greater extent than for hESCs. Six of these initial hits were retested and verified by large-scale cell culture to determine dose-responsive NSC toxicity. One of the compounds retested, amiodarone HCL, was further tested for possible effects on postmitotic neurons, a likely target for transplant therapy. Amiodarone HCL was found to be selectively toxic to NSCs but not to differentiated neurons or glial cells. Treated and untreated NSCs and neurons were then interrogated with global gene expression analysis to explore the mechanisms of action of amiodarone HCl. The gene expression analysis suggests that activation of cell-type specific cationic channels may underlie the toxicity of the drug. CONCLUSIONS/SIGNIFICANCE:In conclusion, we have developed a screening strategy that allows us to rapidly identify clinically approved drugs for use in a Chemistry, Manufacture and Control protocol that can be safely used to deplete unwanted contaminating precursor cells from a differentiated cell product. Our results also suggest that such a strategy is rich in the potential of identifying lineage specific reagents and provides additional evidence for the utility of stem cells in screening and discovery paradigms

    Increased expression of inducible co-stimulator on CD4+ T-cells in the peripheral blood and synovial fluid of patients with failed hip arthroplasties

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    OBJECTIVES: T-cells are considered to play an important role in the inflammatory response causing arthroplasty failure. The study objectives were to investigate the composition and distribution of CD4+ T-cell phenotypes in the peripheral blood (PB) and synovial fluid (SF) of patients undergoing revision surgery for failed metal-on-metal (MoM) and metal-on-polyethylene (MoP) hip arthroplasties, and in patients awaiting total hip arthroplasty. METHODS: In this prospective case-control study, PB and SF were obtained from 22 patients (23 hips) undergoing revision of MoM (n = 14) and MoP (n = 9) hip arthroplasties, with eight controls provided from primary hip osteoarthritis cases awaiting arthroplasty. Lymphocyte subtypes in samples were analysed using flow cytometry. RESULTS: The percentages of CD4+ T-cell subtypes in PB were not different between groups. The CD4+ T-cells in the SF of MoM hips showed a completely different distribution of phenotypes compared with that found in the PB in the same patients, including significantly decreased CD4+ T-central memory cells (p < 0.05) and increased T-effector memory cells (p < 0.0001) in the SF. Inducible co-stimulator (ICOS) was the only co-stimulatory molecule with different expression on CD4+ CD28+ cells between groups. In PB, ICOS expression was increased in MoM (p < 0.001) and MoP (p < 0.05) cases compared with the controls. In SF, ICOS expression was increased in MoM hips compared with MoP hips (p < 0.05). CONCLUSIONS: Increased expression of ICOS on CD4+ T-cells in PB and SF of patients with failed arthroplasties suggests that these cells are activated and involved in generating immune responses. Variations in ICOS expression between MoM and MoP hips may indicate different modes of arthroplasty failure. Cite this article: Professor P. A. Revell. Increased expression of inducible co-stimulator on CD4+ T-cells in the peripheral blood and synovial fluid of patients with failed hip arthroplasties. Bone Joint Res 2016;5:52–60. DOI: 10.1302/2046-3758.52.200057

    Geospatial assessment of coral and mangrove environs of the Andaman Islands

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    An archipelago island system of Andaman is consisting of several hundreds of islands. The coastal environs of these islands are rich in bio-diversity. Most of the islands rimed with fringing corals and healthy mangroves observed near the creeks/streams in the coastal zones. The Sumatra Earthquake occurred on December 26, 2004 recorded a 9.3 Mw not only generated devastating tsunami, but also created lot of tectonic disturbances in the Andaman region. As result of this, northwestern parts of the land got uplifted above a meter from the earlier position. This resulted in the lot of spatial disturbances in the coastal environment. The shallow depth corals were exposed and degraded permanently. Moreover, the mangroves in the up streams were also degraded. A case study from the Interview Island in the northern Andaman was selected to assess the changes. The study was carried out using the Landsat Enhanced Thematic Mapper (ETM) and Indian Remote Sensing (IRS) Linear Imaging Self Scanning Sensor (LISS)-III data were used to infer the spatial changes in the coral and mangrove environments. The assessment was carried out using the Remote Sensing and GIS techniques. The results of the study reveal that the total coral reef area of 17. 82 km2 degraded. The mangrove also showed the same tendency of degradation of total 4.48 km2 area. The techniques and the data were used in the study were given useful insight. The results help in understanding the spatial extent and the distribution of the damage caused due to this natural calamity on the coral and mangrove environment

    Assessment of Tsunami Hazard Vulnerability along the coastal environs of Andaman Islands

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    The December 2004 Sumatra-Andaman earthquake emphasized consistent and comprehensive assessment of areas that are prone to the hazard of Tsunami. It also focused attention on the hazards that could be posed by large subduction zone earthquakes and the Tsunamis that could be further generated. Due to the extremely high vulnerability in the Andaman Islands in South East India, it is essential for planners to develop a comprehensive a priori information database in order to minimize the impact of these destructive situations. A similar effort has been done in this study wherein the entire Andaman Islands have been assessed to target "Tsunami Hazard Vulnerable areas" in accordance with the maximum wave run-up heights and topography. These areas have been extracted from the total area keeping in mind the run-up wave heights on the very day of the Sumatra-Andaman earthquake, i.e., on December 26, 2004. Also, the topographic variations in the region have been studied to establish a relation between the vulnerability of an area and its topography. The hazard of Tsunami puts at threat, the lives of approximately 314,084 people over an area of 5,833.1 km2 in the Andaman Islands. Out of the total area, 708.8 km2 is the hazardous portion which is 12.1 . The islands have experienced a total of 386 earthquakes (above 5.0 magnitude) from the time of Sumatra-Andaman Tsunami till the end of 2009. These statistics clearly indicate the need for hazard preparedness and planning in order to minimize impact during unfortunate circumstances. This study thus aims at the preparation of Tsunami Hazard Vulnerability Map for the Andaman Islands which can be further used by administrative and disaster mitigation organizations as and when required

    Coastal vulnerability assessment for Orissa State, East Coast of India

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    Coastal areas of Orissa State in the northeastern part of the Indian peninsula are potentially vulnerable to accelerated erosion hazard. Along the 480-km coastline, most of the coastal areas, including tourist resorts, hotels, fishing villages, and towns, are already threatened by recurring storm flood events and severe coastal erosion. The coastal habitats, namely the largest rookeries in the world for olive Ridley sea turtles (the extensive sandy beaches of Gahirmatha and Rushikulya), Asia's largest brackish water lagoon (the "Chilika"), extensive mangrove cover of Bhitarkanika (the wildlife sanctuary), the estuarine systems, and deltaic plains are no exception. .The present study therefore is an attempt to develop a coastal vulnerability index (CVI) for the maritime state of Orissa using eight relative risk variables. Most of these parameters are dynamic in nature and require a large amount of data from different sources. In some cases, the base data is from remote sensing satellites; for others it is either from long-term in situ measurements or from numerical models. Zones of vulnerability to coastal natural hazards of different magnitude (high, medium, and low) are identified and shown on a map. In earlier studies, tidal range was assumed to include both permanent and episodic inundation hazards. However, the mean of the long-term tidal records tends to dampen the effect of episodic inundation hazards such as tsunamis. For this reason, in the present study, tsunami run-up has been considered as an additional physical process parameter to calculate the CVI. Coastal regional elevation has also been considered as an additional important variable. This is the first such study that has been undertaken for a part of the Indian coastline The map prepared for the Orissa coast under this study can be used by the state and district administration involved in the disaster mitigation and management plan

    Algal species dynamics in North Arabian Sea using long term ocean colour satellite data

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    North Arabian Sea experiences massive proliferation of variable algal species. The study presents variability of Noctiluca and its association with hydrographic parameters such as sea surface temperature (SST) and water column stability using ten years of satellite data. The area was categorized into three regions, North (23 to 26°N and 56 to 70°E), West (18 to 23°N and 56 to 62°E) and East (18 to 23°N and 62 to 74°E). The Noctiluca dominated area was extracted following approach of Dwivedi et. al. (2015) based on slope of Remote Sensing Reflectance (Rrs) between 488 to 443nm and 488 to 531nm. The data used in the present study depicted two distinct clusters based on regression between difference of Rrs(488) and Rrs(443) with Rrs(488) and Rrs(531). The major clusters representing Noctiluca falls within the range of 0.0004 to 0.0015 (Rrs488-Rrs443) and -0.0012 to -0.0004 (Rrs488-Rrs531). The occurrence of Noctiluca showed bi-modal distribution at an annual scale with the dominance in the northern region during winter monsoon (February- March). In western and eastern region higher frequency of Nuctiluca was during post monsoon having lag of one month from western (September) to eastern (October) region. The periodicity of Noctiluca, carried out using Fourier analysis, showed predominance at annual scale in Northern and semi-annual scale in Western and Eastern region. This indicates that the Noctiluca bloom in the northern region is primarily triggered by winter mixing whereas in western and eastern part of northern Arabian Sea it has combined effect of summer upwelling as well as winter mixing
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