Occurence of legacy and emerging persistent organic pollutants at the Ross Sea and circumpolar deep water convergence (Antarctica)

Persistent organic pollutants (POPs) have attracted the attention of scientists and policy makers in recent decades due to their extreme persistence, semi-volatility, capacity to bio-accumulate in the food chain, and toxic properties. Despite its geographical isolation, extreme meteorological conditions and an almost total absence of local point sources, the Antarctic continent is vulnerable to contamination by POPs, due to the ability of these chemicals to undergo long range atmospheric transport (LRAT) and deposition in the open sea. In a few cases and for limited areas, POPs may be also introduced into the Antarctic ecosystem by human activities (scientific stations, fishing, tourism, accidental oil pills, waste incineration and sewage). Even if various studiesi.e.1,2,3,4,5 have revealed the presence of POPs in air, seawater, sediments and biota in Antarctica, more investigations are needed to implement the number of observations, integrate the data series and meet the indications of the Stockholm Convention and the UNECE protocol in terms of improving knowledge of the temporal and spatial trends of POPs in biotic and abiotic environmental compartments. In this study we present POP concentrations in water samples collected along vertical water columns from seven oceanographic stations located in the Ross Sea and close to the Circumpolar Convergence (see Figure 1). Moreover, the occurrence of emerging and legacy POPs, including polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated naphthalenes (PCNs), organochlorine pesticides (OCPs) and polybrominated diphenylethers (PBDEs) were investigated in order to evaluate their possible sources and relationship with physical and biological processes taking place in the water column. The Ross sea is the formation site of two shelf waters which constitute an important part of the Antarctic Bottom Water (AABWs): the High Salinity Shelf Water (HSSW), which is relatively cold and generated inside the Ross Sea basin and the Ice Shelf Water (ISW). The Ross sea is influenced by only one water mass of external origin, the Circumpolar Deep Water (CDW), which is the largest circulation feature of the Southern Ocean, manly responsible for possible exchange processes between the Antarctic seas and the outer oceans, and thus a possible source of persistent organic pollutants (POPs)2 . The CDW is a relatively warm, salty and nutrient rich water mass carried around Antarctica by the Antarctic Circumpolar Current (ACC)6. Associated with the ACC is the Antarctic Convergence where the cold Antarctic waters meet the warmer waters of the subantarctic creating a zone of upwelling nutrients. Moreover, the Drygalski Glacie Tongue plays an important role in the Polynya development in the Terra Nova Bay, in the Ross sea. An important environmental concern is the accelerated glacier and snow melting that represent a massive release of both naturally occurring chemical substances and organic/inorganic pollutants of anthropogenic origin, which are stored in the deeper layers of the ice and may be delivered to surrounding ecosystems

Enrichment, isolation and biodegradation potential of psychrotolerant polychlorinated-​biphenyl degrading bacteria from the Kongsfjorden (Svalbard Islands, High Arctic Norway)

Persistent organic pollutants (POPs), such as polychlorinated biphenyls (PCBs), have been detected in abiotic Arctic matrices: surface sediments and seawater from coastal areas in the Kongsfjorden were collected and analyzed. Levels of PCBs varied depending on the sampling site. Total PCB concentrations were between 11.63 (site C2W) and 27.69 pg l− 1 (site AW). These levels were comparable to those reported previously in lake sediments from the northern Svalbard. The occurrence and biodegradation potential of cold-adapted PCB-oxidizing bacteria in seawater and sediment along the fjord was also evaluated. After enrichment with biphenyl, 246 isolates were obtained with 45 of them that were able to grow in the presence of the PCB mixture Aroclor 1242, as the sole carbon source. The catabolic gene bphA was harbored by 17 isolates with affiliates to the genera Algoriphagus, Devosia and Salinibacterium that have been never reported as able to utilize PCBs, thus deserving further investigation. The total removal of Aroclor 1242 and selected PCB congeners was evaluated at 4 and 15 °C for eight bphA-harboring isolates and Gelidibacter sp. DS-10. With few exceptions, tested strains showed greater efficiency at 15 than at 4 °C. Isolates were able to reduce most chromatographic peaks by > 50%, with some di- and trichlorobiphenyls that were quite totally removed (> 90%)

Innovative Thermal Management Concepts and Material Solutions for Future Space Vehicles

When entering a planetary atmosphere, space vehicles are exposed to extreme thermal loads. To protect the vehicle’s interior, a thermal protection system is required. Future aerospace transportation demands solutions that exceed the performance of current systems and up-to-date material limits. Therefore, new and disruptive solutions must be envisaged to meet those extreme conditions. In the search of new solutions for sharp leading edges of future hypersonic reentry or transport vehicles, the THOR project, composed of eight European organizations (industries, research centers, and universities) and one Japanese Agency (Japan Aerospace Exploration Agency), is actively working on definition, design, implementation, and simulation of new passive and active thermal management solutions and their verification in relevant environments (high-enthalpy facilities). This paper provides an overview of the recent developments on the four concepts that are targeted in the project, applying different physical methodologies: 1) passive cooling using highly conductive carbon-based fibers, 2) passive cooling with intensive internal radiative exchange, 3) active cooling based on convection heat transfer using a ceramic sandwich/thermal protection system with ceramic foams/lattices, and 4) active transpiration cooling of external surfaces. Details on these thermal management concepts, requirements from end users, and test configurations, as well as results from experimental and numerical verification, are given

Utilidade do coágulo sangüíneo para o isolamento de Sporothrix schenckii de gatos naturalmente infectados

The diagnosis of disseminated sporotrichosis is usually obtained by necropsy and the isolation of Sporothrix schenckii from blood is rare. Fungemia was shown in vivo through the isolation of S. schenckii from peripheral blood of 13 (n=38, 34.2%) cats with naturally acquired sporotrichosis. The coinfection with FIV and with FeLV found, respectively, in 6 (n=34, 17.6%) cases and 1 (n=34, 2.9%), apparently did not alter the frequency of the isolation of S. schenckii from peripheral blood. There was agreement of 84.2% comparing these results to the blood culture results simultaneously achieved. In this way, we propose the clot culture as a practical alternative method, efficient and cheap for the diagnosis of disseminated sporotrichosis in cats in vivo.O diagnóstico de esporotricose disseminada costuma ser obtido através da necrópsia e o isolamento de Sporothrix schenckii do sangue é raro. Fungemia foi demonstrada in vivo através do isolamento do S. schenckii do sangue periférico de 13 (n=38; 34,2%) gatos com esporotricose naturalmente adquirida. A coinfecção com FIV e com FeLV encontradas, respectivamente, em 6 (n=34; 17,6%) casos e 1 (n=34; 2,9%), aparentemente não alterou a freqüência do isolamento de S. schenckii do sangue periférico. Comparando estes resultados aos dos hemocultivos realizados simultaneamente houve concordância de 84,2%. Assim, propomos o cultivo do coágulo como um método alternativo prático, eficiente e econômico para o diagnóstico de esporotricose disseminada em gatos in vivo

Suprapectoral biceps tenodesis: A biomechanical comparison of a new "soft anchor" tenodesis technique versus interference screw biceps tendon fixation

Background The interference screw technique is commonly used in tenodesis of the long head of the biceps for its well-documented robust fixation strength. Some complications may occur after tenodesis with interference screw such as persistent pain, bone fracture and cyst formation. A new technique using a small "soft anchor" has been proposed to avoid the risk of occurrence of the above-mentioned complications associated with the use of the interference screw. However, the proposed technique must provide adequate fixation strength. This study investigated the mechanical performance of the new technique and compared it with interference screw fixation. Methods Fourteen human humeri and proximal biceps were tested after tenodesis using the two techniques. The fixation constructs were cycled 500 times between 20 N and 100 N at 1 Hz to simulate some level of post-operative physical activity. Then, a tensile test to failure was performed to determine the strength of the two tenodesis constructs. Findings The ultimate strength was 238 N (SD 96 N) and 172 N (SD 58 N) for the "soft anchor" and the interference screw, respectively (P = 0.14). In two out of seven repetitions in both groups, failure occurred at low load level due to inaccuracies in performing tenodesis. Considering these cases as outliers, the strength values increased up to 290 N (SD 40 N) and 202 N (SD 32 N) for the "soft anchor" and the interference screw, respectively (P = 0.02). Interpretation The "soft anchor" technique provides a fixation strength comparable with the interference screw, but without using a screw. It could be considered as an alternative for suprapectoral biceps tenodesis