45 research outputs found

    On the type species of Aubignyna and a description of A. hamblensis, a new microforaminifer from temperate shallow waters

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    The genus Aubignyna Margerel, 1970 (type A. mariei) was originally described from the upper Pliocene of NW France. Examination and re-illustration of topotypes of A. mariei Margerel, 1970, the holotype of Buccella planidorso Atkinson, 1969 (from the Recent of Cardigan Bay, Wales) and syntypes of Rotalia perlucida Heron-Allen and Earland, 1913 (from the Clare Island Survey, western Ireland) shows them to be conspecific. Consequently, the type-species of Aubignyna becomes R. perlucida, for which a lectotype is chosen. A new species of microforaminifera formally described here is assigned to Aubignyna and shown to occur in a wide range of intertidal - shallow subtidal, brackish - normal marine estuaries and lagoons in Europe and North America

    Opportunistic features of the foraminifer Stainforthia fusiformis (Williamson): evidence from Frierfjord, Norway

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    Frierfjord is the innermost part of a fjord system which connects with the open sea via Grenlandsfjord. Sills between fjords restrict bottom water circulation and in Frierfjord (sill depth: 23 m, max. water depth: 100 m) efficient deep water renewals at depths greater than about 50 m occur once every one to three years (Rygg et al., 1987). For several centuries waste products (primarily bark and wood fibres), initially from saw mills and later from pulp and paper industries, have been deposited in Frierfjord. Additionally, the fjord has received substantial amounts of organic material and nutrients from domestic sewage. In summary, this led to more or less permanent anoxic deep bottom water conditions. However, slight improvements have occurred over the last decade in response to reduced pollution input (Alve, in prep.). Investigations of short sediment cores (50 m) show that Stainforthia fusiformis exhibits typical opportunistic features. The oxygen concentration of the bottom water immediately above the sediment–water interface was > 1 ml I1at all stations at the time of collection, but the surface sediments reflected recent anoxic conditions. This was especially evident at >70 m where the sediments had a soupy appearance and black colour, with brownish faecal pellets and sometimes light grey, fluffy sediment aggregates in the topmost veneer. The total organic carbon content of the surface sediments is typically between 4 and 6%

    Spatial and temporal organic carbon burial along a fjord to coast transect: A case study from Western Norway

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    We investigated spatial and temporal changes in accumulation rate and source of organic carbon on a gradient along the Lysefjord and the more coastal Høgsfjord, Western Norway. This was achieved through analysis of total organic carbon and nitrogen content of sediment cores, which were radiometrically dated to the early 19th and 20th centuries for the Høgsfjord and Lysefjord, respectively. Benthic foraminifera (protists) were utilized to determine changes in organic carbon supply and Ecological Quality Status (EcoQS) by their accumulation rate (benthic foraminiferal accumulation rate (BFAR)), assemblage composition, species diversity, individual species responses and the composition of stable carbon isotopes of the tests (shells) of Cassidulina laevigata, Hyalinea balthica and Melonis barleeanus. Organic carbon accumulation rates were greatest closest to the river Lyse at the head of the Lysefjord (83–171 g C m−2 yr−1). The organic carbon at the head of the fjord is mainly terrestrial in origin, and this terrestrial influence becomes progressively less seaward. The δ13C in H. balthica tests as well as the benthic foraminiferal assemblage composition also showed a clear fjord to coast gradient. Organic carbon accumulation rates were lower and less variable at the seaward study sites (13–61 g C m−2 yr−1). We observe no temporal trend in organic carbon, carbon isotopes, EcoQS or foraminiferal assemblage composition in the Lysefjord. In contrast, in the Høgsfjord, there seems to have been an increase in organic carbon accumulation rates during the 1940s. Subsequent accumulation rates are stable. The foraminiferal assemblages in the surface sediments reflect a recent transition from good/moderate to moderate/bad EcoQS.publishedVersio

    Professional thinking in Individual Plan processes

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    This article explores the kind of critical and reflective thinking taht influences the social and health care professionals in the Individual Plan process. An inter-professional group of six healthcare and social researchers collected the data, which consisted of indepth interviews with 12 service providers who were the clients´ coordinators and one day centre leader. By focusing on reflective thinking in a critical perspective, it is concluded that coordinators are guided by different philosophical and theoretical perspectives in this process; a mixture of reasoning strategies, caring as a relational concept and a mixture of philosophical frameworks. To improve critical thinking in Individual Plan processes, coordinators need to be conscious about their way of thinking in action

    Drivers of organic carbon distribution and accumulation in the northern Barents Sea

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    Sedimentary properties and accumulation rates on the continental shelf and in the deep sea reflect temporal oceanographic, biological and chemical processes occurring in the water column and the sediment surface. We used the radionuclides 210Pb, 226Ra, and 137Cs activities to estimate sedimentation rates during the last century at nine stations in the northern Barents Sea region. Elemental (C, N) and stable isotopic composition (δ13C, δ15N) were also analysed from the nine stations sampled in August 2018, and, for five other stations sampled in August and December 2019, and in March and May 2021. Sediment accumulation rates varied between 130 and 1 410 g m−2 y−1. The < 63 μm normalized total organic carbon (TOC63) and the total nitrogen from the sediment surface varied between 0.90–2.56 % and 0.13–0.33 %, respectively. Ice-free shelf stations had higher TOC63 and possibly fresher organic matter (high δ13C, low δ15N) than ice-covered more northern stations. The opposite trend was observed for total inorganic carbon. We found that these trends in biogeochemical parameters were spatially structured by the winter sea ice concentration and biological production differences, and exhibited a south-north separation of the Polar Front region. The low and stable organic carbon accumulation rate (1.7–13.4 g Corg m-2 y−1; ARtoc) is a function of slow sedimentation rates, and high degradation and residence time in the water column and at the sediment–water interface. Overall, the ARtoc has been stable for the past 100 years, with a slight increase from the early 1970s to the present at the shelf and slope stations. Our results highlight that spatial scales of variability of the studied sedimentary parameters are linked to spatial patterns of important environmental variables (e.g., chlorophyll-a, sea ice concentration) in the region. In contrast, no seasonal differences were observed in the sediment parameters of revisited stations, and the dated sediment geochemical profiles did not exhibit substantial longer-term variation. This means that climate-induced changes in variables that modify the sedimentary geochemistry of the environment may affect benthic community activity and structure before leaving a record in ARtoc

    Stainforthia: portrait

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    Esta foraminifera foi encontrada em uma amostra coletada em Hamble Estuary, Hampshire, Inglaterra. As espécies não foram identificadasComponente Curricular::Educação Superior::Ciências Biológicas::Microbiologi
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