2,881 research outputs found

    Den fria leken – Kvalitativ intervjustudie om pedagogers syn på fri lek i förskoleverksamheten

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    Sammanfattning: Syftet med vårt arbete var att synliggöra pedagogers sätt att se på den fria leken och vilken, om det finns någon, roll de själva anser sig ha i denna. Vår frågeställning i studien är: Vad är pedagogernas syn på den fria leken och sin egen roll i denna? Vi genomförde en kvalitativ intervjuundersökning i form av en respondentundersökning. Undersökningen bestod av samtalsintervjuer med tio pedagoger som valdes ut med hjälp av ett s.k. bekvämlighetsurval. Frågorna var förberedda men ändrades något utefter hur dialogen med respektive pedagog fortskred. I vårt intervjuresultat går det att utläsa hur majoriteten av respondenterna ansåg den fria leken vara den som skapas och formas av barnen mellan de planerade aktiviteterna i förskoleverksamheten, medan vissa ansåg att all lek är fri lek. Vidare menade respondenterna att deras roll i den fria leken främst innebär att finnas tillhands vid behov och annars till mesta del vara en passiv observatör. Genom att vara uppmärksamma på barnens intressen i leken kan de sedan möta dessa i verksamheten. Den övergripande lärdomen för verksamma lärare av vår studie och den teoretiska litteratur denna bygger på är att vad de menar är fri lek och vilken, om någon, roll de själva har i denna. Detta får konsekvenser för vad barnen erbjuds för lärande- och utvecklingsmöjligheter i verksamheten. Det är därför en angelägen uppgift att som pedagog själv reflektera över sitt sätt att se på dessa två frågor.

    ‘I had a lump in my stomach’: Swedish gay and lesbian students' experiences of their time in school

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    Objectives: Gay and lesbian youth can experience ignorance and a lack of acknowledgement surrounding their sexual orientation during their time in school. This qualitative interview study describes how Swedish gay and lesbian students experience their secondary school years on the basis that society has heteronormative values. Methods: The data is based on eight telephone interviews with gay and lesbian young adults, aged 18–25 and was analysed using a qualitative narrative approach. Findings: The findings presented four themes: not fitting into the norm of heterosexuality, lacking confirmation of their own homosexuality, finding courage, seeing the school as a supportive or a non-supportive environment. Conclusions: A way to normalise homosexuality can be to discuss sexual development and attraction from a health-promoting perspective. Professionals working in school need to feel comfortable with issues such as sexuality in order to create a situation of confidence for the student

    Effects of climate, fire and vegetation development on Holocene changes in total organic carbon concentration in three boreal forest lakes in northern Sweden

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    International audienceNear infrared spectroscopy (NIRS), diatoms, pollen, charcoal, loss-on-ignition (LOI), and nutrient elements in lake sediments were used to assess important factors controlling Holocene changes in the total organic carbon (TOC) concentration, pCO2, color and pH of lake water in three boreal forest lakes in northern Sweden. The results suggest that mire formation, fire frequency and humidity are the most important forcing factors on millennial timescales. Mires produce humic acids that become available to the lakes, whereas fires may reduce the pool of carbon in the catchments, and humidity controls the transportation of allochthonous carbon into the lakes. Vegetation development and temperature as sole factors are of minor importance for the TOC concentrations in these lakes on a millennial timescale. Two of the sites indicate that liming and possibly fish introduction and rotenone treatment in recent time has led to increased TOC, color and pH in the lake water, and changed the diatom community composition to an assemblage that has never been present before. Given the predicted climate change scenario that suggests a more humid climate, expanding mires and less frequent fires, our paleolimnological data suggest that TOC concentrations can be expected to increase in boreal forest lakes in the future. Since super-saturation and emission of CO2 from lakes is correlated to the TOC concentration of lake water, higher TOC concentrations may lead to increased emission of CO2 from lakes to the atmosphere

    Program for the feasibility of developing a high pressure acoustic levitator

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    This is the final report for the program for the feasibility of developing a high-pressure acoustic levitator (HPAL). It includes work performed during the period from February 15, 1987 to October 26, 1987. The program was conducted for NASA under contract number NAS3-25115. The HPAL would be used for containerless processing of materials in the 1-g Earth environment. Results show that the use of increased gas pressure produces higher sound pressure levels. The harmonics produced by the acoustic source are also reduced. This provides an improvement in the capabilities of acoustic levitation in 1-g. The reported processing capabilities are directly limited by the design of the Medium Pressure Acoustic Levitator used for this study. Data show that sufficient acoustic intensities can be obtained to levitate and process a specimen of density 5 g/cu cm at 1500 C. However, it is recommended that a working engineering model of the HPAL be developed. The model would be used to establish the maximum operating parameters of furnace temperature and sample density

    South Atlantic island record reveals a South Atlantic response to the 8.2 kyr event

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    International audienceOne of the most distinct climate fluctuations during the Holocene is the short and rapid event centred around 8200 years ago, the 8.2 kyr event, which was most likely triggered by glacial melt-water forcing from the receding Laurentide ice-sheet. Evidence for this cooling has primarily been reported from sites around the North Atlantic, but an increasing number of observations imply a more wide-spread occurrence. Palaeoclimate archives from the Southern Hemisphere have hitherto failed to uncover a distinct climatic anomaly associated with the 8.2 kyr event. Here we present a lake sediment record from Nightingale Island in the central South Atlantic showing enhanced precipitation between 8275 and 8025 cal. yrs BP, most likely as a consequence of increased sea surface temperature (SST). We show that this is consistent with climate model projections of a warming of the South Atlantic in response to reduced north-ward energy transport during the 8.2 kyr event

    Forcing mechanisms behind variations in TOC concentration of lake waters Forcing mechanisms behind variations in total organic carbon (TOC) concentration of lake waters during the past eight centuries – palaeolimnological evidence from southern Sweden Forcing mechanisms behind variations in TOC concentration of lake waters

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    International audienceDecadal-scale variations in total organic carbon (TOC) concentration in lake water since AD 1200 in two small lakes in southern Sweden were reconstructed based on visible-near infrared spectroscopy (VNIRS) of their recent sediment successions. In order to assess the impacts of local land-use changes and regional variations in 5 sulphur deposition and climate on the inferred changes in TOC concentration, the same sediment records were subjected to multi-proxy palaeolimnological analyses. Changes in lake-water pH were inferred from diatom analysis, whereas pollen-based land-use reconstructions (Landscape Reconstruction Algorithm) together with geo-chemical records provided information on catchment-scale environmental changes, 10 and comparisons were made with available records of climate and population density. Our long-term reconstructions reveal that TOC concentrations were generally high prior to AD 1900, with second-order variations coupled mainly to changes in agricultural land-use intensity. The last century showed significant changes, and unusually low TOC concentrations were recorded in 1930–1990, followed by a recent increase. Vari-15 ations in sulphur emissions, with an increase in the early 1900s to a peak around AD 1980 and a subsequent decrease, were most likely the main driver of these dynamics, although processes related to the introduction of modern forestry and recent increases in precipitation and temperature may have contributed. The increase in lake-water TOC concentration from around AD 1980 may therefore reflect a recovery process. Given 20 that the effects of sulphate deposition now subside, other forcing mechanisms related to land management and climate change will possibly become the main drivers of TOC concentration changes in boreal lake waters in the future

    Historical TOC concentration minima during peak sulfur deposition in two Swedish lakes

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    International audienceDecadal-scale variations in total organic carbon (TOC) concentration in lake water since AD 1200 in two small lakes in southern Sweden were reconstructed based on visible–near-infrared spectroscopy (VNIRS) of their recent sediment successions. In order to assess the impacts of local land-use changes, regional variations in sulfur, and nitrogen deposition and climate variations on the inferred changes in TOC concentration, the same sediment records were subjected to multi-proxy palaeolimnological analyses. Changes in lake-water pH were inferred from diatom analysis , whereas pollen-based land-use reconstructions (Landscape Reconstruction Algorithm) together with geochemical records provided information on catchment-scale environmental changes, and comparisons were made with available records of climate and population density. Our long-term reconstructions reveal that inferred lake-water TOC concentrations were generally high prior to AD 1900, with additional variability coupled mainly to changes in forest cover and agricultural land-use intensity. The last century showed significant changes, and unusually low TOC concentrations were inferred at AD 1930–1990, followed by a recent increase , largely consistent with monitoring data. Variations in sulfur emissions, with an increase in the early 1900s to a peak around AD 1980 and a subsequent decrease, were identified as an important driver of these dynamics at both sites, while processes related to the introduction of modern forestry and recent increases in precipitation and temperature may have contributed, but the effects differed between the sites. The increase in lake-water TOC concentration from around AD 1980 may therefore reflect a recovery process. Given that the effects of sulfur deposition now subside and that the recovery of lake-water TOC concentrations has reached pre-industrial levels, other forcing mechanisms related to land management and climate change may become the main drivers of TOC concentration changes in boreal lake waters in the future

    Delayed maximum northern European summer temperatures during the Last Interglacial as a result of Greenland Ice Sheet melt

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    This is the author accepted manuscript. The final version is available from the Geological Society of America via the DOI in this record.Here we report a new quantitative mean July temperature reconstruction using non-biting midges (chironomids) from the Danish Last Interglacial (LIG) site Hollerup (spanning 127–116 ka). We find that peak mean July temperatures of 17.5 °C, similar to those of the present day (1961–1990 CE), were reached shortly before the onset of the regional Carpinus pollen zone. Through comparison to terrestrial and marine sequences we demonstrate that peak summer warmth took place some three millennia after the onset of LIG warming in Europe, a marked delay in line with records from the North Atlantic. Crucially, the warmest northern European summer temperatures appear to follow maximum Greenland Ice Sheet mass loss, implying that meltwater substantially reduced Atlantic Meridional Overturning Circulation and depressed European temperatures during the early part of the interglacial.Turney and Fogwill thank the Australian Research Council (grants FL100100195, FT120100004, LP120200724). Thanks to Bjørn Buchardt for providing the C:N data, Angela Self for help with statistical analysis, David Campbell and Alan Bedford for laboratory work, and three reviewers for their constructive comments

    DIP-2 suppresses ectopic neurite sprouting and axonal regeneration in mature neurons.

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    Neuronal morphology and circuitry established during early development must often be maintained over the entirety of animal lifespans. Compared with neuronal development, the mechanisms that maintain mature neuronal structures and architecture are little understood. The conserved disco-interacting protein 2 (DIP2) consists of a DMAP1-binding domain and two adenylate-forming domains (AFDs). We show that the Caenorhabditis elegans DIP-2 maintains morphology of mature neurons. dip-2 loss-of-function mutants display a progressive increase in ectopic neurite sprouting and branching during late larval and adult life. In adults, dip-2 also inhibits initial stages of axon regeneration cell autonomously and acts in parallel to DLK-1 MAP kinase and EFA-6 pathways. The function of DIP-2 in maintenance of neuron morphology and in axon regrowth requires its AFD domains and is independent of its DMAP1-binding domain. Our findings reveal a new conserved regulator of neuronal morphology maintenance and axon regrowth after injury
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