Annotated record of the detailed examination of Mn deposits from ARA Islas Orcadas Cruise 7 core stations

The purpose of this volume, the seventh in a series of similar publications (Goodell, 1964, 1965, 1968; Frakes 1971, 1973 ; Cassidy et al., 1977), is to continue a presentation to the research community of sediment core descriptions and attendant data of cored and otherwise obtained sediments retrieved in waters of the Southern Ocean aboard the research vessel, ARA Islas Orcadas (formerly, USNS Eltanin), as a part of the circumpolar survey begun by Eltanin in 1962 (see issue of Antarctic Journal of the United States, Vol. 8, No. 3, 1973). The data presented herein are concerned with the results of coring activities aboard cruise 0775 of Islas Orcadas, the second marine geology coring cruise of this vessel under the terms of the present United States-Argentine agreement. The core descriptions are organised as follows: 1) a brief summary of the coring objectives of the cruise, together with a discussion of core recovery; 2) a table and map of station location data for materials retrieved; 3) a table of tentative age-dates for each piston core; 4) an explanation of the laboratory procedures and descriptive criteria used in the description of the sediments, and 5) lithologic descriptions of the piston and trigger cores, and the piston and trigger core bag samples.

Biogeochemistry of the Eastern Weddell Gyre

The Southern Ocean (SO) plays a key role in modulating atmospheric CO2 via physical and biological processes. However, over much of the SO, biological activity is iron-limited. New in situ data from the Antarctic zone south of Africa in a region centered at -20°E - 25°E reveal a previously overlooked region of high primary production, comparable in size to the northwest African upwelling region. Here, sea ice together with enclosed icebergs is channeled by prevailing winds to the eastern boundary of the Weddell Gyre, where a sharp transition to warmer waters causes melting. This cumulative melting provides a steady source of iron, fuelling an intense phytoplankton bloom that is not fully captured by monthly satellite production estimates. These findings imply that future changes in sea-ice cover and dynamics could have a significant effect on carbon sequestration in the SO.

Particle size of Saharan dust in the Atlantic Ocean, from October 2012 to November 2013

Mineral dust has a large impact on regional and global climate, depending on its particle size. Especially in the Atlantic Ocean downwind of the Sahara, the largest dust source on earth, the effects can be substantial but are poorly understood. This study focuses on seasonal and spatial variations in particle size of Saharan dust deposition across the Atlantic Ocean, using an array of submarine sediment traps moored along a transect at 12° N. We show that the particle size decreases downwind with increased distance from the Saharan source, due to higher gravitational settling velocities of coarse particles in the atmosphere. Modal grain sizes vary between 4 and 33 µm throughout the different seasons and at five locations along the transect. This is much coarser than previously suggested and incorporated into climate models. In addition, seasonal changes are prominent, with coarser dust in summer, and finer dust in winter and spring. Such seasonal changes are caused by transport at higher altitudes and at greater wind velocities during summer than in winter. Also the latitudinal migration of the dust cloud, associated with the Intertropical Convergence Zone, causes seasonal differences in deposition as the summer dust cloud is located more to the north, and more directly above the sampled transect. Furthermore, increased precipitation and more frequent dust storms in summer coincide with coarser dust deposition. Our findings contribute to understanding Saharan dust transport and deposition relevant for the interpretation of sedimentary records for climate reconstructions, as well as for global and regional models for improved prediction of future climate.

Annotated record of the detailed examination of Mn deposits from ARA Islas Orcadas Cruise 16 core stations

The purpose of this volume, the seventh in a series of similar publications (Goodell, 1964, 1965, 1968; Frakes 1971, 1973 ; Cassidy et al., 1977), is to continue a presentation to the research community of sediment core descriptions and attendant data of cored and otherwise obtained sediments retrieved in waters of the Southern Ocean aboard the research vessel, ARA Islas Orcadas (formerly, USNS Eltanin), as a part of the circumpolar survey begun by Eltanin in 1962 (see issue of Antarctic Journal of the United States, Vol. 8, No. 3, 1973). The data presented herein are concerned with the results of coring activities aboard cruise 1678 of Islas Orcadas, the fith and final marine geology coring cruise of this vessel under the terms of the present United States-Argentine agreement. The core descriptions are organised as follows: 1) a brief summary of the coring objectives of the cruise, together with a discussion of core recovery; 2) a table and map of station location data for materials retrieved; 3) a table of tentative age-dates for each piston core; 4) an explanation of the laboratory procedures and descriptive criteria used in the description of the sediments, and 5) lithologic descriptions of the piston and trigger cores, and the piston and trigger core bag samples.

Randomized trial of 8 Gy in 1 versus 20 Gy in 5 fractions of radiotherapy for neuropathic pain due to bone metastases (Trans-Tasman Radiation Oncology Group, TROG 96.05)

Background and purpose: Despite numerous randomized trials investigating radiotherapy (RT) fractionation schedules for painful bone metastases, there are very few data on RT for bone metastases causing pain with a neuropathic component. The Trans-Tasman Radiation Oncology Group undertook a randomized trial comparing the efficacy of a single 8 Gy (8/1) with 20 Gy in 5 fractions (20/5) for this type of pain. Materials and methods: Eligible patients had radiological evidence of bone metastases from a known malignancy with no change in systemic therapy within 6 weeks before or anticipated within 4 weeks after RT, no other metastases along the distribution of the neuropathic pain and no clinical or radiological evidence of cord/cauda equina compression. All patients gave written informed consent. Primary endpoints were pain response within 2 months of commencement of RT and time to treatment failure (TTF). The hypothesis was that 8/1 is at least as effective as 20/5 and the planned sample size was 270 patients. Results: Between February 1996 and December 2002, 272 patients were randomized (8/1:20/5 = 137:135) from 15 centres (Australia 11, New Zealand 3, UK 1). The commonest primary cancers were lung (31%), prostate (29%) and breast (8%); index sites were spine (89%), rib (9%), other (2%); 72% of patients were males and the median age was 67 (range 2989). The median overall survival (95% CI) for all randomized patients was 4.8 mo (4.2-5.7 mo). The intention-to-treat overall response rates (95% Cl) for 8/1 vs 20/5 were 53% (45-62%) vs 61% (53-70%), P = 0.18. Corresponding figures for complete response were 26% (18-34%) vs 27% (19-35%), P = 0.89. The estimated median TTFs (95% CI) were 2.4 mo (2.0-3.3 mo) vs 3.7 mo (3.1-5.9 mo) respectively. The hazard ratio (95% Cl) for the comparison of TTF curves was 1.35 (0.99-1.85), log-rank P = 0.056. There were no statistically significant differences in the rates of re-treatment, cord compression or pathological fracture by arm. Conclusions: 8/1 was not shown to be as effective as 20/5, nor was it statistically significantly worse. Outcomes were generally poorer for 8/1, although the quantitative differences were relatively small. (c) 2004 Elsevier Ireland Ltd. All rights reserved.

Food intake and risk of squamous cell carcinoma of the skin in a community: The Nambour skin cancer cohort study

There is some evidence that dietary factors may modify the risk of squamous cell carcinoma (SCC) of the skin, but the association between food intake and SCC has not been evaluated prospectively. We examined the association between food intake and SCC incidence among 1,056 randomly selected adults living in an Australian sub-tropical community. Measurement-error corrected estimates of intake in 15 food groups were defined from a validated food frequency questionnaire in 1992. Associations with SCC risk were assessed using Poisson and negative binomial regression to the persons affected and tumour counts, respectively, based on incident, histologically confirmed tumours occurring between 1992 and 2002. After multivariable adjustment, none of the food groups was significantly associated with SCC risk. Stratified analysis in participants with a past history of skin cancer showed a decreased risk of SCC tumours for high intakes of green leafy vegetables (RR = 0.45, 95% CI = 0.22-0.91; p for trend = 0.02) and an increased risk for high intake of unmodified dairy products (RR = 2.53, 95% CI: 1.15-5.54; p for trend = 0.03). Food intake was not associated with SCC risk in persons who had no past history of skin cancer. These findings suggest that consumption of green leafy vegetables may help prevent development of subsequent SCCs of the skin among people with previous skin cancer and that consumption of unmodified dairy products, such as whole milk, cheese and yoghurt, may increase SCC risk in susceptible persons.

SCOTROC 2A: Carboplatin followed by docetaxel or docetaxel gemcitabine as first-line chemotherapy for ovarian cancer

The feasibility of sequential carboplatin followed by docetaxel-based therapy for untreated ovarian cancer was determined. Patients received four q3w cycles of carboplatin AUC 7, then four q3w cycles of either docetaxel 100 mg m(-2) (day 1) (arm A); docetaxel 75 mg m(-2) (day 8) and gemcitabine 1250 mg m(-2) (days 1,8) (arm B) or docetaxel 25 mg m(-2) and gemcitabine 800 mg m(-2) (both given weekly (days 1,8,15)) (arm C). A total of 44 patients were randomised to each treatment arm. None of the arms demonstrated an eight cycle completion rate (70.5/72.7/45.5% in arms A/B/C, respectively), which was statistically greater than 60% (P = 0.102, P = 0.056, P = 0.982) which was our formal feasibility criteria, although only the completion rate in arm C was clearly worse than this level. The overall response rate (ORR) after carboplatin was 65.7% in 70 evaluable patients. In evaluable patients, ORRs after docetaxel-based cycles were: arm A 84.0% (21 out of 25); arm B 77.3% (17 out of 22); arm C 69.6% (16 out of 23). At follow-up (median 30 months), median progression-free survival times were: arm A 15.5 months (95% Cl: 10.5 - 20.6); arm B 18.1 months (95% Cl: 15.9 - 20.3); arm C, 13.7 months (95% Cl: 12.8 - 14.6). Neutropenia was the predominant grade 3 - 4 haematological toxicity: 77.8/85.7/54.4% in arms A/B/C, respectively. Dyspnoea was markedly increased in both gemcitabine-containing arms (P = 0.001) but was worse in arm C. Although just failing to rule out eight cycle completion rates less than 60%, within the statistical limitations of these small cohorts, the overall results for arms A and B are encouraging. Larger phase III studies are required to test these combinations.

Проблеми на обучението по програмиране

Доклад по покана, поместен в сборника на Националната конференция "Образованието в информационното общество", Пловдив, октомври, 2006 г.

Compilation of downward flux observations from sediment trap deployments in the Atlantic Ocean - Contribution to EURO-BASIN's Data integration

We provide a compilation of downward fluxes (total mass, POC, PON, BSiO2, CaCO3, PIC and lithogenic/terrigenous fluxes) from over 6000 sediment trap measurements distributed in the Atlantic Ocean, from 30 degree North to 49 degree South, and covering the period 1982-2011. Data from the Mediterranean Sea are also included. Data were compiled from different sources: data repositories (BCO-DMO, PANGAEA), time series sites (BATS, CARIACO), published scientific papers and/or personal communications from PI's. All sources are specifed in the data set. Data from the World Ocean Atlas 2009 were extracted to provide each flux observation with contextual environmental data, such as temperature, salinity, oxygen (concentration, AOU and percentage saturation), nitrate, phosphate and silicate.

Global compilation of benthic data sets I

Approaches to quantify the organic carbon accumulation on a global scale generally do not consider the small-scale variability of sedimentary and oceanographic boundary conditions along continental margins. In this study, we present a new approach to regionalize the total organic carbon (TOC) content in surface sediments (<5 cm sediment depth). It is based on a compilation of more than 5500 single measurements from various sources. Global TOC distribution was determined by the application of a combined qualitative and quantitative-geostatistical method. Overall, 33 benthic TOC-based provinces were defined and used to process the global distribution pattern of the TOC content in surface sediments in a 1°x1° grid resolution. Regional dependencies of data points within each single province are expressed by modeled semi-variograms. Measured and estimated TOC values show good correlation, emphasizing the reasonable applicability of the method. The accumulation of organic carbon in marine surface sediments is a key parameter in the control of mineralization processes and the material exchange between the sediment and the ocean water. Our approach will help to improve global budgets of nutrient and carbon cycles.

Sedimentation rates and geochemical analysis of surface sediments from the South Atlantic

Extensive investigations of sedimentary barium were performed in the southern South Atlantic in order to assess the reliability of the barium signal in Antarctic sediments as a proxy for paleoproductivity. Maximum accumulation rates of excess barium were calculated for the Antarctic zone south of the polar front where silica accumulates at high rates. The correspondence between barium and opal supports the applicability of barium as a proxy for productivity. Within the Antarctic zone north of today's average sea ice maximum, interglacial vertical rain rates of excess barium are high, with a maximum occurring during the last deglaciation and early Holocene and during oxygen isotope chronozone 5.5. During these periods, the maximum silica accumulation was supposedly located south of the polar front. Glacial paleoproductivity, instead, was low within the Antarctic zone. North of the polar front, significantly higher barium accumulation occurs during glacial times. The vertical rain rates, however, are as high as in the glacial Antarctic zone. Therefore there was no evidence for an increased productivity in the glacial Southern Ocean.