1,424 research outputs found

    Simultaneous determination of indium and nitrogen contents of InGaAsN quantum wells by optical in situ monitoring

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    In situ monitoring of metal-organic vapor phase epitaxialgrowth of InGaAsN∕GaAs multiquantum wells is studied. The complex refractive index of InGaAsN is determined for several indium and nitrogen contents based on the fits to the reflectance curve. Taking advantage of the different effects caused by the incorporation of indium and nitrogen on the complex refractive index of InGaAsN, the InGaAsN quantum well nitrogen and indium contents are simultaneously determined in situ.Peer reviewe

    The spectral energy distribution of the scattered light from dark clouds

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    A dark cloud is exposed to the ambient radiation field of integrated starlight in the Galaxy. Scattering of starlight by the dust particles gives rise to a diffuse surface brightness of the dark nebula. The intensity and the spectrum of this diffuse radiation can be used to investigate, e.g., the scattering parameters of the dust, the optical thickness of the cloud, and as a probe of the ambient radiation field at the location of the cloud. An understanding of the scattering process is also a prerequisite for the isolation of broad spectral features due to fluorescence or to any other non-scattering origin of the diffuse light. Model calculations are presented for multiple scattering in a spherical cloud. These calculations show that the different spectral shapes of the observed diffuse light can be reproduced with standard dust parameters. The possibility to use the observed spectrum as a diagnostic tool for analyzing the thickness of the cloud and the dust particle is discussed

    In situ determination of InGaAs and GaAsN composition in multiquantum-well structures

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    Metal-organic vapor phase epitaxialgrowth of InGaAs/GaAs and GaAsN/GaAs multiquantum-well (MQW) structures was monitored by in situ reflectometry at 635 nm using a normal incidence reflectance setup. The reflectance signal is found to change significantly during both quantum-well (QW) and barrier growth regions. A matrix method is used to calculate the theoretical reflectance curve and comparing the theoretical curves to the measured ones the complex refractive index of the ternary alloys are derived. Consequently, when the behavior of the complex refractive indices of InGaAs and GaAsN is known as a function of composition, the composition of all the QWs in the MQW strucure can be determined in situ.Peer reviewe

    Occupational injuries and diseases among commercial fishers in Finland 1996–2015

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    Background: Commercial fishing is recognised as one of the most hazardous professions worldwide. In Finland, commercial fishing has some special characteristics, including fishing on ice during frozen waters, and pluriactivity of the fisher family to gain additional income. The goal of this study was to describe injury characteristics among commercial fishers in Finland during the years 1996–2015. With this information, we wish to promote creation of effective safety campaigns and interventions. Materials and methods: The data for this study was acquired from The Farmers’ Social Insurance Institution, who handles the mandatory pension and occupational injury insurance of Finnish commercial fishers. Descriptive statistics was used to categorise and analyse the data that comprised the anonymized insurance history of 1954 insured fishers and reports on 1135 compensated injuries, 11 fatalities, and 53 occupational disease cases. Results: The results show, that the injury rate of Finnish commercial fishers is high. Forty per cent of the fishing-related injuries occur aboard or when entering or leaving the vessel, while 37% happened ashore, and 11% on sea or lake ice. The most common type of incident is preceded by a slip, trip, or sway followed by a fall to lower level. The injuries result in a median disability length of 21 days. An elevated risk for Finnish (vs. Swedish) speaking, as well as for male fishers was found. The occupational diseases of the studied population were for the most part results of manual, repetitive and/or physically straining work due to e.g. hauling in fishing equipment. Due to small numbers and lack of case data, it is not possible to make any further analysis of the 11 fatalities, which were all drownings. Conclusions: Based on our findings, injury prevention should be targeted, besides preventing fatalities because of drowning, at mitigating the risks for slips, trips, and falls both aboard and ashore

    Mechanism and biological role of profilin-Srv2/CAP interaction

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    Profilin and cyclase-associated protein (CAP, known in yeast as Srv2) are ubiquitous and abundant actin monomer- binding proteins. Profilin catalyses the nucleotide exchange on actin monomers and promotes their addition to filament barbed ends. Srv2/CAP recycles newly depolymerized actin monomers from ADF/cofilin for subsequent rounds of polymerization. Srv2/CAP also harbors two proline- rich motifs and has been suggested to interact with profilin. However, the mechanism and biological role of the possible profilin-Srv2/CAP interaction has not been investigated. Here, we show that Saccharomyces cerevisiae Srv2 and profilin interact directly (K-D similar to 1.3 mu M) and demonstrate that a specific proline-rich motif in Srv2 mediates this interaction in vitro and in vivo. ADP- actin monomers and profilin do not interfere with each other's binding to Srv2, suggesting that these three proteins can form a ternary complex. Genetic and cell biological analyses on an Srv2 allele (srv2-201) defective in binding profilin reveals that a direct interaction with profilin is not essential for Srv2 cellular function. However, srv2-201 causes a moderate increase in cell size and partially suppresses the cell growth and actin organization defects of an actin binding mutant profilin (pfy1-4). Together these data suggest that Srv2 is an important physiological interaction partner of profilin

    In situ determination of nitrogen content in InGaAsN quantum wells

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    The growth of InGaAsN/GaAs multiple quantum well structures by metal-organic vapor phase epitaxy is monitored by in situ reflectometry. The nitrogen incorporation is found to depend superlinearly on the precursor flow and a threshold value for the flow is observed. By in situmeasurements of the InGaAsN quantum well samples with a fixed indium content, the change in the reflectance during the quantum wellgrowth is found to be linearly dependent on the quantum well nitrogen content. A model to determine the nitrogen content already during the growth is developed. Moreover, the field of application of in situ reflectance monitoring is extended from thick layers to thin layers, including quantum wells.Peer reviewe

    Hyvinvoinnin turvaamisen rajat : Näköaloja talouskriisiin ja hyvinvointivaltion kehitykseen Suomessa

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    Miten syksyllä 2008 alkanut globaali talouskriisi vaikuttaa pitkällä aikavälillä suomalaiseen hyvinvointivaltioon? Jos olisimme antiikin Kreikassa, voisimme mennä Delfoin oraakkelin luo Apollonin temppeliin ja esittää tämän kysymyksen ennuspapittarelle. Eräänä lokakuun päivänä 2009 Kelan tiloihin kokoontui joukko suomalaisia hyvinvointivaltion huippuasiantuntijoita. He kertoivat julkisen talouden, kansalaisten toimeentulon ja terveyden näkökulmista kolmelle ”professori-oraakkelille” eli tanskalaiselle Nina Smithille, ruotsalaiselle Johan Fritzellille ja saksalaisille Karl Hinrichsille Suomen kokemuksista edellisestä, 1990-luvun alun lamasta, sen jälkeisestä kehityksestä sekä omista tulevaisuuden arvioistaan. Seuraavana päivänä oraakkelit lausuivat ennustuksensa, joka paljastetaan tässä raportissa.10,00 euro

    Predictors for occupational injuries and diseases among commercial fishers in Finland 1996–2015

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    Fishing is a hazardous occupation worldwide. Commercial fishers in Finland are an aging and diminishing population with a high injury rate. Insurance claims data for self-employed Finnish commercial fishers during the years 1996 through 2015 (n = 1951) were analysed to assess predictors for occupational injuries and diseases. Out of the available variables, fishery location, career length, and participation in the voluntary occupational health service programme were not significant predictors. Male gender (OR 2.02; 95% CI 1.37–2.99), Finnish mother tongue vs. Swedish (OR 1.98, 95% CI 1.53–2.55), and higher income levels from fishing (four income categories, OR range: 1.71–3.53) were associated with higher odds for a compensated occupational injury or disease claim among commercial fishers in the final multivariate model. The identified risk groups could be targeted for interventions, and the content of the occupational health service programme should be developed to gain protective effect
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