Physical oceanography during POLARSTERN cruise ARK-XVIII/1a

In spite of the lack of bottom reaching convection in the Greenland Sea since the 1980s, convection continues to ventilate the Greenland Gyre down to intermediate depth. The variability of this ventilation activity is determined here annually for eight winters according to a multiple criteria catalogue, applied to annual summer conductivity-temperature-depth transects along 75°N. The comparison of the ventilation depths with the meteorological forcing, the ice cover, and the stratification of the water column shows the decisive influence of the hydrographic structure in the upper and intermediate layers. Ice, on the other hand, is not necessary for convection to occur. Ice formation does not even lead to particularly deep convection. A stability maximum, which currently dominates the vertical structure of the water column at medium depth, limits the ventilation depths effectively.

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.

Effect of smoke inhalation on viscoelastic properties and ventilation distribution in sheep

Smoke inhalation injuries are the leading cause of mortality from burn injury. Airway obstruction due to mucus plugging and bronchoconstriction can cause severe ventilation inhomogeneity and worsen hypoxia. Studies describing changes of viscoelastic characteristics of the lung after smoke inhalation are missing. We present results of a new smoke inhalation device in sheep and describe pathophysiological changes after smoke exposure. Fifteen female Merino ewes were anesthetized and intubated. Baseline data using electrical impedance tomography and multiple-breath inert-gas washout were obtained by measuring ventilation distribution, functional residual capacity, lung clearance index, dynamic compliance, and stress index. Ten sheep were exposed to standardized cotton smoke insufflations and five sheep to sham smoke insufflations. Measured carboxyhemoglobin before inhalation was 3.87 +/- 0.28% and 5 min after smoke was 61.5 +/- 2.1%, range 50-69.4% ( P < 0.001). Two hours after smoke functional residual capacity decreased from 1,773 +/- 226 to 1,006 +/- 129 ml and lung clearance index increased from 10.4 +/- 0.4 to 14.2 +/- 0.9. Dynamic compliance decreased from 56.6 +/- 5.5 to 32.8 +/- 3.2 ml/ cmH(2)O. Stress index increased from 0.994 +/- 0.009 to 1.081 +/- 0.011 ( P < 0.01) ( all means +/- SE, P < 0.05). Electrical impedance tomography showed a shift of ventilation from the dependent to the independent lung after smoke exposure. No significant change was seen in the sham group. Smoke inhalation caused immediate onset in pulmonary dysfunction and significant ventilation inhomogeneity. The smoke inhalation device as presented may be useful for interventional studies.

Dietary selectivity for the toxic cyanobacterium Lyngbya majuscula and resultant growth rates in two species of opisthobranch mollusc

Trophodynamics of blooms of the toxic marine cyanobacterium Lyngkya majuscula were investigated to determine dietary specificity in two putative grazers: the opisthobranch molluscs, Stylocheilus striatus and Bursatella leachii. S. striatus is associated with L. majuscula blooms and is known to sequester L. majuscula metabolites. The dietary specificity and toxicodynamics of B. leachii in relation to L. majuscula is less well documented. In this study we found diet history had no significant effect upon dietary selectivity of S. striatus when offered a range of plant species. However, L. majuscula chemotype may alter S. striatus' selectivity for this cyanobacterium. Daily biomass increases between small and large size groups of both species were recorded in no-choice consumption trials using L. majuscula. Both S. striatus and B. leachii preferentially consumed L. majuscula containing lyngbyatoxin-a. Increase in mass over a 10-day period in B. leachii (915%) was significantly greater than S. striatus (150%), yet S. striatus consumed greater quantities of L. majuscula (g day(-1)) and thus had a lower conversion efficiency (0.038) than B. leachii (0.081) based on sea hare weight per gram of L. majuscula consumed day(-1). Our findings suggest that growth rates and conversion efficiencies may be influenced by sea hare maximum growth potential, acquisition of secondary metabolites or diet type. (C) 2005 Elsevier B.V. All rights reserved.

GOVERNANÇA CORPORATIVA E ÍNDICE DE SUSTENTABILIDADE EMPRESARIAL: UMA ANÁLISE DO VALOR DAS AÇÕES

A Governança Corporativa, que surge com uma superação ao conflito de agência, exige dentre seus princípios que as organizações adotem uma estrutura que proteja os direitos dos acionistas e assegure a divulgação e a transparência de fatos relevantes e suas demonstrações contábeis. No Brasil, em 2000, a BM&FBOVESPA criou níveis diferenciados de Governança Corporativa a fim de estimular o interesse de investidores e auxiliar na valorização das empresas que podem aderir voluntariamente a um dos segmentos. Juntamente à preocupação quanto às boas práticas de governança, existe outra questão altamente importante e preocupante que se refere à sustentabilidade. Cada vez mais investidores buscam empresas que atuam sob os princípios do Triple Bottom Line, o qual abrange elementos das esferas ambientais, sociais e econômicas, como uma forma de segurança para seus investimentos. Em 2005, foi criado o Índice de Sustentabilidade Empresarial (ISE), pela BM&FBOVESPA, como uma referência nas boas práticas de sustentabilidade e comprometimento das empresas com a sustentabilidade empresarial. Neste contexto, este estudo visa verificar se existem diferenças entre as médias dos retornos mensais das ações, no período de cinco anos antes e após a sua adesão à Governança Corporativa e ao Índice de Sustentabilidade Empresarial. O método utilizado para testar as hipóteses das três amostras selecionadas foi o Paired-Samples T Test, por meio do software SPSS, versão 18.0. Os resultados obtidos demonstraram que, no caso das amostras do ISE (p= 0,006 < 0,05) e GC_ISE (p= 0,030 < 0,05) a hipótese nula é rejeitada, pois existe diferença significativa entre as médias dos retornos mensais e no caso da amostra de GC (p= 0,081 > 0,05) a hipótese nula não é rejeitada, pois não existe diferença significativa entre estas médias. Analisando os valores das médias é possível perceber que a maioria delas sofre queda no segundo momento de análise, apesar disso não é possível generalizar afirmando que a Governança Corporativa e o Índice de Sustentabilidade Empresarial não agregam valor às empresas e aos acionistas. Isto porque o momento econômico analisado coincide com a crise financeira do subprime, que atingiu as principais bolsas de valores do mundo e influenciou fortemente as ações na BM&FBovespa, principalmente em 2008.

Operator-induced errors in Hartmann-Shack wavefront sensing:model eye study

Purpose: To evaluate the effects of instrument realignment and angular misalignment during the clinical determination of wavefront aberrations by simulation in model eyes. Setting: Aston Academy of Life Sciences, Aston University, Birmingham, United Kingdom. Methods: Six model eyes were examined with wavefront-aberration-supported cornea ablation (WASCA) (Carl Zeiss Meditec) in 4 sessions of 10 measurements each: sessions 1 and 2, consecutive repeated measures without realignment; session 3, realignment of the instrument between readings; session 4, measurements without realignment but with the model eye shifted 6 degrees angularly. Intersession repeatability and the effects of realignment and misalignment were obtained by comparing the measurements in the various sessions for coma, spherical aberration, and higher-order aberrations (HOAs). Results: The mean differences between the 2 sessions without realignment of the instrument were 0.020 μm ± 0.076 (SD) for Z3 - 1(P = .551), 0.009 ± 0.139 μm for Z3 1(P = .877), 0.004 ± 0.037 μm for Z4 0 (P = .820), and 0.005 ± 0.01 μm for HO root mean square (RMS) (P = .301). Differences between the nonrealigned and realigned instruments were -0.017 ± 0.026 μm for Z3 - 1(P = .159), 0.009 ± 0.028 μm for Z3 1 (P = .475), 0.007 ± 0.014 μm for Z4 0(P = .296), and 0.002 ± 0.007 μm for HO RMS (P = 0.529; differences between centered and misaligned instruments were -0.355 ± 0.149 μm for Z3 - 1 (P = .002), 0.007 ± 0.034 μm for Z3 1(P = .620), -0.005 ± 0.081 μm for Z4 0(P = .885), and 0.012 ± 0.020 μm for HO RMS (P = .195). Realignment increased the standard deviation by a factor of 3 compared with the first session without realignment. Conclusions: Repeatability of the WASCA was excellent in all situations tested. Realignment substantially increased the variance of the measurements. Angular misalignment can result in significant errors, particularly in the determination of coma. These findings are important when assessing highly aberrated eyes during follow-up or before surgery. © 2007 ASCRS and ESCRS.

Regionalism, globalisation and international order:Europe and Southeast Asia

New regionalism and globalization have been prominent themes in academic and political debates since the beginning of the 1990s. Despite the considerable amount of scholarly attention that the new regionalism has received in recent years, its full empirical and theoretical potential has yet to be fully investigated. This illuminating study provides an overview of new avenues in theorizing regionalism and proposes a consolidated framework for analysis and comparison. Offering a comparative historical perspective of European and Southeast Asian regionalism, it presents new and imaginative insights into the theory and practice of regionalism and the links between regional developments, globalization and international order. Contents: Introduction; Regionalism and integration theory the first wave: traditional approaches; New regionalism the second wave: towards a framework for comparative regionalism; Regionalism in the EU and ASEAN during the Cold War: the first wave; Second-wave regionalism: the post-Cold War period; Identifying regions: emerging regional identities in Europe and East Asia; Conclusion; Appendix; Bibliography; Index.

Cloud базирана система за събиране, съхраняване и анализ на логови съобщения

Доклад, поместен в сборника на Националната конференция "Образованието в информационното общество", Пловдив, май, 2012 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.

Compilation of planktonic foraminiferal census counts from the Southern Hemisphere Oceans

We present an improved database of planktonic foraminiferal census counts from the Southern Hemisphere Oceans (SHO) from 15°S to 64°S. The SHO database combines 3 existing databases. Using this SHO database, we investigated dissolution biases that might affect faunal census counts. We suggest a depth/[DCO3]2- threshold of ~3800 m/[DCO3]2- = ~-10 to -5 µmol/kg for the Pacific and Indian Oceans, and ~4000 m/[DCO3]2- = ~0 to 10 µmol/kg for the Atlantic Ocean, under which core-top assemblages can be affected by dissolution and are less reliable for paleo-sea surface temperature (SST) reconstructions. We removed all core-tops beyond these thresholds from the SHO database. This database has 598 core-tops and is able to reconstruct past SST variations from 2° to 25.5°C, with a root mean square error of 1.00°C, for annual temperatures. To inspect dissolution affects SST reconstruction quality, we tested the data base with two "leave-one-out" tests, with and without the deep core-tops. We used this database to reconstruct Summer SST (SSST) over the last 20 ka, using the Modern Analog Technique method, on the Southeast Pacific core MD07-3100. This was compared to the SSST reconstructed using the 3 databases used to compile the SHO database. Thus showing that the reconstruction using the SHO database is more reliable, as its dissimilarity values are the lowest. The most important aspect here is the importance of a bias-free, geographic-rich, database. We leave this dataset open-ended to future additions; the new core-tops must be carefully selected, with their chronological frameworks, and evidence of dissolution assessed.

Foraminiferal faunal estimates of paleotemperature: Circumventing the no-analog problem yields cool ice age tropics

The sensitivity of the tropics to climate change, particularly the amplitude of glacial-to-interglacial changes in sea surface temperature (SST), is one of the great controversies in paleoclimatology. Here we reassess faunal estimates of ice age SSTs, focusing on the problem of no-analog planktonic foraminiferal assemblages in the equatorial oceans that confounds both classical transfer function and modern analog methods. A new calibration strategy developed here, which uses past variability of species to define robust faunal assemblages, solves the no-analog problem and reveals ice age cooling of 5° to 6°C in the equatorial current systems of the Atlantic and eastern Pacific Oceans. Classical transfer functions underestimated temperature changes in some areas of the tropical oceans because core-top assemblages misrepresented the ice age faunal assemblages. Our finding is consistent with some geochemical estimates and model predictions of greater ice age cooling in the tropics than was inferred by Climate: Long-Range Investigation, Mapping, and Prediction (CLIMAP) [1981] and thus may help to resolve a long-standing controversy. Our new foraminiferal transfer function suggests that such cooling was limited to the equatorial current systems, however, and supports CLIMAP's inference of stability of the subtropical gyre centers.

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.