Effect of ozone oxidative preconditioning in preventing early radiation-induced lung injury in rats

Ionizing radiation causes its biological effects mainly through oxidative damage induced by reactive oxygen species. Previous studies showed that ozone oxidative preconditioning attenuated pathophysiological events mediated by reactive oxygen species. As inhalation of ozone induces lung injury, the aim of this study was to examine whether ozone oxidative preconditioning potentiates or attenuates the effects of irradiation on the lung. Rats were subjected to total body irradiation, with or without treatment with ozone oxidative preconditioning (0.72 mg/kg). Serum proinflammatory cytokine levels, oxidative damage markers, and histopathological analysis were compared at 6 and 72 h after total body irradiation. Irradiation significantly increased lung malondialdehyde levels as an end-product of lipoperoxidation. Irradiation also significantly decreased lung superoxide dismutase activity, which is an indicator of the generation of oxidative stress and an early protective response to oxidative damage. Ozone oxidative preconditioning plus irradiation significantly decreased malondialdehyde levels and increased the activity of superoxide dismutase, which might indicate protection of the lung from radiation-induced lung injury. Serum tumor necrosis factor alpha and interleukin-1 beta levels, which increased significantly following total body irradiation, were decreased with ozone oxidative preconditioning. Moreover, ozone oxidative preconditioning was able to ameliorate radiation-induced lung injury assessed by histopathological evaluation. In conclusion, ozone oxidative preconditioning, repeated low-dose intraperitoneal administration of ozone, did not exacerbate radiation-induced lung injury, and, on the contrary, it provided protection against radiation-induced lung damage.

Bioindication of ozone using milkweed plants in Southern Ontario

Ambient (03) ozone concentrations were compared to ozone damage on milkweed plants to determine if there was a correlation. Eight survey sites of at least 100 plants each were located within 5 kilometers of Air Quality Index (AQI) stations in southern Ontario. Sites were visited nine times from June-September (2007) and milkweed leaves from 75 plants were assessed using methods pioneered in the United States. Ambient 0 3 results were calculated into SUM65, seasonal cumulative 0 3, and total 03. The 0 3 exposure indices SUM65 and cumulative 0 3 were tested statistically to determine which index is biologically relevant to milkweed as an 0 3 damage indicator species. The milkweed damage indices were incidence of leaves damaged per plant, incidence of plants damaged per site, and total 0 3• The incidence of plants injured per site was the best damage parameter with an F(1,28)=17.37, p=0.0003 for SUM65 and F(1,28)=7.5, p=O.0106 for cumulative 03 .. Milkweed plants showed quantifiable ozone damage with minimal spatial differences in damage and thus have potential use as a biomonitor species in southern Ontario.

Micromorphology of Last Glacial Maximum Grounding line sediments around the Antarctic Peninsula

Sediments recovered from seven Last Glacial Maximum grounding lines sites, around the Antarctic Peninsula, were analyzed using micromorphology. This is the first evidence that grounding line sediments from around the Antarctic Peninsula have complex deformational histories and subglacial origins. It was determined that grounding zone wedge contain multiple units, or diamicton layers, with homogenized boundaries. The multiple diamicton units / layers are due to the accretionary formation of a grounding line wedge. All the sediments were deposited via deformation, and continual reincorporation, homogenization of lower diamicton layers by upper diamicton layers produced what macroscopically appeared to be a single massive diamicton unit. The morainal ridge that was sampled, alternatively, is composed of a single unit, or diamicton layer, that was subglacial in origin and believed to have been pushed out to form a ridge that was subsequently deformed via glacial push.

Taxonomy, Bionomics and Biofouling of Bryozoans from the Coasts of India and the Antarctic Waters

The study of bryozoans, an important group of coelomates in the marine environment is an integral part of faunistic investigations. Bryozones are an ancient, aberrant phylum of microscopic but fascinating and often beautiful animals that build intricate colonies sometimes resembling minicolonies. In this study taxonomy, bionomics and biofouling of bryozoans from the coasts of India and the Antarctic waters. The marine biofouling is found to be hazardous. Bryozoans are microscopic , sessile,colonical coelomates that are permanently fastened in exoskeletal cases or gelatinous material of their own secretion.It is hoped that this work would help the future researchers to devote attention on microbenthos of the continental shelf of India when samples are made available through collections conducted by any ocean going vessel. In the present work an extensive study on the bryozoan foulers that occur at five selected sites of the cochin estury had to be examined and since the hydrographic parameters such as salinity, temperature, pH and dissolved oxygen in the estury,vary greatly from that in the open ocean, a frequent monitoring of these parameters was essential.

New oligomer-bound antioxidants for improved flex crack resistance and ozone resistance

New oligomer-bound antioxidants have been prepared by condensation reaction. The efficiency and permanence of these oligomer- bound paraphenylene diamines as antioxidants has been compared with conventional amine type antioxidants in NR, SBR, IIR and NBR and in elastomer blends like NR/BR and NR/SBR. The oligomer-bound antioxidants are found to impart improved ozone, flex resistance and mechanical properties to the vulcanizates of NR, SBR, IIR and NBR and to blends of NR/BR and NR/ SBR in comparison with those containing conventional antioxidants.

INDIAN AND ANTARCTIC BRYOZOANS - TAXONOMY AND OBSERVATIONS ON TOXICOLOGY

This thesis embodies findings on a taxonomical investigation of a group of lower marine invertebrates belonging to the category coelomata. Bryozoans are well known both in fossil and recent taxonomical history. They comprise of about 5,000 living and 16000 fossil species. Bryozoans are well known for their taxonomic abundance and structural diversity,representing the various ecological niches ranging from the intertidal to the abyssal benthic. At a time when global marine biological diversity has become a concern of not only to the scientists but also to the policy makers,an understanding of species diversity and abundance are cardinal aspects of biological studies. Geological time scales which is known that by Pre-Cambrian, marine invertebrate diversity reach the maximum and this diversity has become more comprehensive as time advanced. Taxonomists a vanishing species of scientists have become more concerned in discerning patterns of species diversity. The basic tool for this is identification fo animals. with this idea in mind a detailed study of taxonomy of bryozoan was undertaken . The major part of this thesis is devoted to describe various species of bryozoans with detailed description and ecotypical variations.The pattern of distribution and abundance which are important aspects of animal groups have also been documented. Possible effects of heavy metal contamination on the tolerance and growth of bryozoans, a few species of which have been eliminated from the chronically polluted areas of Cochin backwaters have also been documented.

Geochemistry of core sediment from antarctic region

Southern Ocean (SO) is the fourth largest Ocean comprising the southern portions of the Atlantic Ocean, Indian Ocean and Pacific Ocean. Sediment core sample (660 34’S and 580 40’E)was collected onboard O.R.V Sagar Nidhi from January to March 2010 in the Fourth Southern Ocean expedition cruise launched by the National Centre for Antarctic and Ocean Research, Goa . Sedimentary records from this area reveal the sensitivity and climatic variability’s of the region over a large time scale. Organic matter (OM) and textural behaviour of the samples were analyzed and processed concurrently. Distribution of OM, Total Organic Carbon (TOC), Protein, Lipid and Carbohydrate along with the trace metal was highlighted. Textural variation was in the array of Sand >Clay >Silt. Sand content ranges from 30.29% to 80.11%. The order of relative distribution of OM was Lipid >Protein > TOC > Carbohydrate. The average concentrations of TOC, Protein, Lipid and Carbohydrate were 2.2 mg/g, 1.2 mg/g, 3.3 mg/g and 1.1mg/g respectively. Protein to carbohydrate ratio and lipid to carbohydrate ratio were also encountered to understand the respective freshness and nutritional quality of the sediments. Trace metal distribution showed the average concentration was maximum for Mn and minimum for Co.

Processes influencing ozone levels in Alaskan forest fire plumes during long-range transport over the North Atlantic

A case of long-range transport of a biomass burning plume from Alaska to Europe is analyzed using a Lagrangian approach. This plume was sampled several times in the free troposphere over North America, the North Atlantic and Europe by three different aircraft during the IGAC Lagrangian 2K4 experiment which was part of the ICARTT/ITOP measurement intensive in summer 2004. Measurements in the plume showed enhanced values of CO, VOCs and NOy, mainly in form of PAN. Observed O3 levels increased by 17 ppbv over 5 days. A photochemical trajectory model, CiTTyCAT, was used to examine processes responsible for the chemical evolution of the plume. The model was initialized with upwind data and compared with downwind measurements. The influence of high aerosol loading on photolysis rates in the plume was investigated using in situ aerosol measurements in the plume and lidar retrievals of optical depth as input into a photolysis code (Fast-J), run in the model. Significant impacts on photochemistry are found with a decrease of 18% in O3 production and 24% in O3 destruction over 5 days when including aerosols. The plume is found to be chemically active with large O3 increases attributed primarily to PAN decomposition during descent of the plume toward Europe. The predicted O3 changes are very dependent on temperature changes during transport and also on water vapor levels in the lower troposphere which can lead to O3 destruction. Simulation of mixing/dilution was necessary to reproduce observed pollutant levels in the plume. Mixing was simulated using background concentrations from measurements in air masses in close proximity to the plume, and mixing timescales (averaging 6.25 days) were derived from CO changes. Observed and simulated O3/CO correlations in the plume were also compared in order to evaluate the photochemistry in the model. Observed slopes change from negative to positive over 5 days. This change, which can be attributed largely to photochemistry, is well reproduced by multiple model runs even if slope values are slightly underestimated suggesting a small underestimation in modeled photochemical O3 production. The possible impact of this biomass burning plume on O3 levels in the European boundary layer was also examined by running the model for a further 5 days and comparing with data collected at surface sites, such as Jungfraujoch, which showed small O3 increases and elevated CO levels. The model predicts significant changes in O3 over the entire 10 day period due to photochemistry but the signal is largely lost because of the effects of dilution. However, measurements in several other BB plumes over Europe show that O3 impact of Alaskan fires can be potentially significant over Europe.

Alkyl nitrates in outflow from North America over the North Atlantic during Intercontinental Transport of Ozone and Precursors 2004

This paper is based on alkyl nitrate measurements made over the North Atlantic as part of the International Consortium for Research on Atmospheric Transport and Transformation (ICARTT). The focus is on the analysis of air samples collected on the UK BAe-146 aircraft during the Intercontinental Transport of Ozone and Precursors (ITOP) project, but air samples collected on board the NASA DC-8 and NOAA WP-3D aircraft as part of a Lagrangian experiment are also used. The ratios between the alkyl nitrates and their parent hydrocarbons are compared with those expected from chemical theory. Further, a box model is run to investigate the temporal evolution of the alkyl nitrates in three Lagrangian case studies and compared to observations. The air samples collected during ITOP do not appear to be strongly influenced by oceanic sources, but rather are influenced by emissions from the N.E. United States and from Alaskan fires. There also appears to be a widespread common source of ethyl nitrate and 1-propyl nitrate other than from their parent hydrocarbons. The general agreement between the alkyl nitrate data and photochemical theory suggests that during the first few days of transport from the source region, photochemical production of alkyl nitrates, and thus ozone, had taken place. The observations in the more photochemically processed air masses are consistent with the alkyl nitrate production reactions no longer dominating the peroxy radical self/cross reactions. Further, the results also suggest that the rates of photochemical processing in the Alaskan smoke plumes were small.

Four-dimensional variational assimilation of ozone profiles from the Microwave Limb Sounder on the Aura satellite

Ozone profiles from the Microwave Limb Sounder (MLS) onboard the Aura satellite of the NASA's Earth Observing System (EOS) were experimentally added to the European Centre for Medium-range Weather Forecasts (ECMWF) four-dimensional variational (4D-var) data assimilation system of version CY30R1, in which total ozone columns from Scanning Imaging Absorption Spectrometer for Atmospheric CHartographY (SCIAMACHY) onboard the Envisat satellite and partial profiles from the Solar Backscatter Ultraviolet (SBUV/2) instrument onboard the NOAA-16 satellite have been operationally assimilated. As shown by results for the autumn of 2005, additional constraints from MLS data significantly improved the agreement of the analyzed ozone fields with independent observations throughout most of the stratosphere, owing to the daily near-global coverage and good vertical resolution of MLS observations. The largest impacts were seen in the middle and lower stratosphere, where model deficiencies could not be effectively corrected by the operational observations without the additional information on the ozone vertical distribution provided by MLS. Even in the upper stratosphere, where ozone concentrations are mainly determined by rapid chemical processes, dense and vertically resolved MLS data helped reduce the biases related to model deficiencies. These improvements resulted in a more realistic and consistent description of spatial and temporal variations in stratospheric ozone, as demonstrated by cases in the dynamically and chemically active regions. However, combined assimilation of the often discrepant ozone observations might lead to underestimation of tropospheric ozone. In addition, model deficiencies induced large biases in the upper stratosphere in the medium-range (5-day) ozone forecasts.