लक्षद्दीप समूह जीववैविधता और व्यवस्था

कृपया पूरा लेख पढे

dosimetric studies of mixed energy intensity modulated radiation therapy for prostate cancer treatments

Dosimetric studies of mixed field photon beam intensity modulated radiation therapy (IMRT) for prostate cancer using pencil beam (PB) and collapsed cone convolution (CCC) algorithms using Oncentra MasterPlan treatment planning system (v. 4.3) are investigated in this study. Three different plans were generated using 6 MV, 15 MV, and mixed beam (both 6 and 15 MV). Fifteen patients with two sets of plans were generated: one by using PB and the other by using CCC for the same planning parameters and constraints except the beam energy. For each patient's plan of high energy photons, one set of photoneutron measurements using solid state neutron track detector (SSNTD) was taken for this study. Mean percentage ofV66 Gyin the rectum is18.55±2.8,14.58±2.1, and16.77±4.7for 6 MV, 15 MV, and mixed-energy plans, respectively. Mean percentage ofV66 Gyin bladder is16.54±2.1,17.42±2.1,and16.94±41.9for 6 MV, 15 MV, and mixed-energy plans, respectively. Mixed fields neutron contribution at the beam entrance surface is 45.62% less than at 15 MV photon beam. Our result shows that, with negligible neutron contributions, mixed field IMRT has considerable dosimetric advantage

Productivity of the coral reef alga Halimeda gracilis Harv. ex. J.Ag. Minicoy island, Lakshadweep

The present investigation deals with the morphology and productivity of Halimeda gracilis from 3 locations of Minicoy Island. The estimated percentage cover of H. Gracilis were 32.6% on the reef, 10.9% on the shore reef and 17.3% on the seagrass beds. Halimeda in scagrass beds had the highest biomass of 1339.2 g/m2 followed by the shore reef with 1256.0 g/m2 and the lowest biomass at the reef (420.8 g/m2). The length of Halimeda gracilis varied between 4.5 cm at the reef and 8.5 cm in scagrass beds but the weight showed only slight variation. Length weight reintionship of Halimeda gracilis indicated least variable morphology at reef and lagoon. Plants collected from seagrass beds in the lagoon showed highest productivity of 0.64 g C/m2 / day while the lowest production of 0.08 gC/m2/day was recorded from the shore reef. Environmental parameters such as temperature salinity dissolved oxygen and nutrients were monitored at the three stations

Domestic waste and its impact on production of Caulerpa racemosa (Forssk.) Weber v. Bosse at Minicoy Island, Lakshadweep

The present study deals with the impact of domestic waste on Caulerpa recemosa collected from a densely populated village of Minicoy Island. Length of erect foliar portion of C. racemosa collected from the polluted site was only 2.15 cm while at control site it was 6.16 cm. Similarly weight of the plant was also low (0.26 g) when compared to unpolluted site (0.95 g). Length – weight relationship indicated wider variability in the size of the plant at polluted site with lower values. Net primary production values showed 7.2 fold more production at control site than that of polluted site. Environmental parameters such as temperature, salinity, turbidity and nutrients were monitored

Distribution and abundance of seaweeds on a coral reef at Minicoy Island, Lakshadweep

Macroalgal distribution and abundance in different regions of a coral reef was studied for a period of one year in 1998 at Minicoy Island, Lakshadweep. The biomass distribution of algac on the seaward side of the reef varied from 620.2 g wet wt/m2 in September to a maximum of 2800.6 g wet wt/m2 in August. Reef flat had a minimum in July (251 g wet wt/m2) and a maximum in December (2074.9 g wet wt/m2). Significant seasonal differences were noticed in the three regions with maximum biomass during monsoon on the seaward side and in the postmonsoon at reef flat and lagoon side of the reef. Laurencia ceylanica ornate (32.0%) were major algae of he reef flat and lagoon side of the reef. Minor algae observed on the reef were Gelidiella acerasa. Bocrgesenia forbesil, Sargassum duplicatum and Cladophoropsis zollingeri. Hydrographical parameters such as water temperature, salinity, nutrients, rainfall and hours of exposure of algac were monitored

FLUKA Monte Carlo for Basic Dosimetric Studies of Dual Energy Medical Linear Accelerator

General purpose Monte Carlo code for simulation of particle transport is used to study the basic dosimetric parameters like percentage depth dose and dose profiles and compared with the experimental measurements from commercial dual energy medical linear accelerator. Varian Clinac iX medical linear accelerator with dual energy photon beams (6 and 15 MV) is simulated using FLUKA. FLAIR is used to visualize and edit the geometry. Experimental measurements are taken for 100 cm source-to-surface (SSD) in 50 × 50 × 50 cm3PTW water phantom using 0.12 cc cylindrical ionization chamber. Percentage depth dose for standard square field sizes and dose profiles for various depths are studied in detail. The analysis was carried out using ROOT (a DATA analysis frame work developed at CERN) system. Simulation result shows good agreement in percentage depth dose and beam profiles with the experimental measurements for Varian Clinac iX dual energy medical linear accelerator

FLUKA Monte Carlo for Basic Dosimetric Studies of Dual Energy Medical Linear Accelerator

General purpose Monte Carlo code for simulation of particle transport is used to study the basic dosimetric parameters like percentage depth dose and dose profiles and compared with the experimental measurements from commercial dual energy medical linear accelerator. Varian Clinac iX medical linear accelerator with dual energy photon beams (6 and 15 MV) is simulated using FLUKA. FLAIR is used to visualize and edit the geometry. Experimental measurements are taken for 100 cm source-to-surface (SSD) in 50 × 50 × 50 cm3 PTW water phantom using 0.12 cc cylindrical ionization chamber. Percentage depth dose for standard square field sizes and dose profiles for various depths are studied in detail. The analysis was carried out using ROOT (a DATA analysis frame work developed at CERN) system. Simulation result shows good agreement in percentage depth dose and beam profiles with the experimental measurements for Varian Clinac iX dual energy medical linear accelerator

Not Available

Not AvailableA green turtle was washed ashore on 10-8-98 about 1 km south of the Lakshadweep Harbour Works at Minicoy Information on the landings and bleaching of turtles from Lakshadweep are rare. Out of the four species of turtles found in Lakshadweep, Chelonia mydas is common. At Minicoy this species is reported to have nested in thousands in the past. Presently the nesting area has been reduced due to human inhabitation.Not Availabl

On a green turtle Chelonia mydas washed ashore at Minicoy Island,Lakshadweep

A green turtle was washed ashore on 10-8-98 about 1 km south of the Lakshadweep Harbour Works at Minicoy Information on the landings and bleaching of turtles from Lakshadweep are rare. Out of the four species of turtles found in Lakshadweep, Chelonia mydas is common. At Minicoy this species is reported to have nested in thousands in the past. Presently the nesting area has been reduced due to human inhabitation

Not Available

Not AvailableA green turtle was washed ashore on 10-8-98 about 1 km south of the Lakshadweep Harbour Works at Minicoy Information on the landings and bleaching of turtles from Lakshadweep are rare. Out of the four species of turtles found in Lakshadweep, Chelonia mydas is common. At Minicoy this species is reported to have nested in thousands in the past. Presently the nesting area has been reduced due to human inhabitation.Not Availabl