136 research outputs found

    Electronic properties of H on vicinal Pt surfaces: A first-principles study

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    In this work, we use the first-principle density-functional approach to study the electronic structure of a H atom adsorbed on the ideal Pt(111) and vicinal Pt(211) and Pt(331) surfaces. Full three-dimensional potential-energy surfaces (3D PES's) as well as local electronic density of states on various adsorption sites are obtained. The results show that the steps modify the PES considerably. The effect is nonlocal and extends into the region of the (111) terraces. We also find that different type of steps have different kind of influence on the PES when compared to the one of the ideal Pt(111) surface. The full 3D PES's calculated in this work provide a starting point for the theoretical study of vibrational and diffusive dynamics of H adatoms adsorbed on these vicinal surfaces.Comment: 8 pages with 5 figures and 3 tables. In version 2, there have been made some minor changes and a bigger one in Section III.A.1 where the results of the test calculations dealt with the accuracy of the present results have been adde

    Structure and magnetic properties of adatoms on carbon nanotubes

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    We use ab initio methods to calculate the physical and electronic properties of carbon adatoms on different characteristic carbon nanotubes. We found that for every tube the energetically favored adsorption geometry is a “bridgelike” structure between two surface carbons, perpendicular to the long axis of the tube. For adsorption perpendicular or parallel to the axis, the calculations show that the adatom is spin polarized, although the magnitude of the magnetic moment depends mainly on the electronic structure of the nanotube itself.Peer reviewe

    Up to seven-fold inter-hospital differences in obstetric anal sphincter injury rates- A birth register-based study in Finland

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    <p>Abstract</p> <p>Background</p> <p>The occurrence of obstetric anal sphincter injuries (OASIS) - which may have serious, long-term effects on affected women, including faecal incontinence, despite primary repair - varies widely between countries and have been chosen one of the indicators for patient safety in Organisation for Economic Cooperation and Development (OECD) countries and in Nordic countries.</p> <p>Findings</p> <p>The aim of the study was to assess risks of OASIS among five university teaching hospitals and 14 non-university central hospitals with more than 1,000 deliveries annually during 1997-2007 in Finland. Women with singleton vaginal deliveries divided into two populations consisting of all 168,637 women from five university hospitals and all 255,660 women from non-university hospitals, respectively, derived from population-based register. Primiparous and multiparous women with OASIS (n = 2,448) were compared in terms of possible risk factors to primiparous and multiparous women without OASIS, respectively, using stepwise logistic regression analysis. The occurrences of OASIS varied from 0.7% to 2.1% in primiparous and from 0.1% to 0.3% in multiparous women among the university hospitals. Three-fold inter-hospital differences in OASIS rates did not significantly change after adjustment for patient mix or the use of interventions. In non-university hospitals OASIS rates varied from 0.2% to 1.4% in primiparous and from 0.02% to 0.4% in multiparous women, and the results remained virtually unchanged after adjustment for known risks.</p> <p>Conclusions</p> <p>Up to 3.2-fold inter-hospital differences in OASIS risk demonstrates significant differences in the quality of Finnish obstetric care.</p

    Mind the gap between ICES nations' future seafood consumption and aquaculture production

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    As the human population grows and climate change threatens the stability of seafood sources, we face the key question of how we will meet increasing demand, and do so sustainably. Many of the 20 International Council for the Exploration of the Sea (ICES) member nations have been global leaders in the protection and management of wild fisheries, but to date, most of these nations have not developed robust aquaculture industries. Using existing data and documentation of aquaculture targets from government and industry, we compiled and analysed past trends in farmed and wild seafood production and consumption in ICES nations, as well as the potential and need to increase aquaculture production by 2050. We found that the majority of ICES nations lacks long-term strategies for aquaculture growth, with an increasing gap between future domestic production and consumption—resulting in a potential 7 million tonne domestic seafood deficit by 2050, which would be supplemented by imports from other countries (e.g. China). We also found recognition of climate change as a concern for aquaculture growth, but little on what that means for meeting production goals. Our findings highlight the need to prioritize aquaculture policy to set more ambitious domestic production goals and/or improve sustainable sourcing of seafood from other parts of the world, with explicit recognition and strategic planning for climate change affecting such decisions. In short, there is a need for greater concerted effort by ICES member nations to address aquaculture’s long-term future prospects

    A case study on risk and return implications of emissions trading in power generation investments

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    This paper explores quantitative implications of the European Union Emissions Trading Scheme (EU ETS) on power capacity investment appraisal in a deregulated market. Risk and return of three different types of power plants, a gas-fired condensing power plant; a hydro power plant with a reservoir; and an off-shore wind power farm, are studied and compared in the regulatory environment of Finland. A single-firm exogenous and stochastic price model is used to simulate possible market outcomes. The model runs suggest that emissions trading increases the expected return of all three power plant technologies. The increase in risk is significant only in the case of the gas-fired power plant. Keywords

    Reframing gender and feminist knowledge construction in marketing and consumer research: missing feminisms and the case of men and masculinities

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    Gender has been theorised and studied in many ways and across different disciplines. Although a number of these theorisations have been recognised and adopted in marketing and consumer research, the significance of feminism in knowledge construction has largely remained what we would call ‘unfinished’. Based on a critical reframing of gender research in marketing and consumer research, in dialogue with feminist theory, this article offers theoretical and practical suggestions for how to reinvigorate these research efforts. The analysis highlights dominant theorisations of gender, relating to gender as variable, difference and role; as fundamental difference and structuring; and as cultural and identity constructions. This reframing emphasises various neglected or ‘missing feminisms’, including queer theory; critical race, intersectional and transnational feminisms; material-discursive feminism; and critical studies on men and masculinities. A more detailed discussion of the latter, as a relatively new, growing and politically contentious area, is further developed to highlight more specifically which feminist and gender theories are mainly in use in marketing and consumer research and which are little or not used. In the light of this, it is argued that marketing and related disciplines have thus far largely neglected several key contemporary gender and feminist theorisations, particularly those that centre on gender power relations. The potential impact of these theoretical frames on transdisciplinary studies in marketing and consumer research and research agenda(s) is discussed

    Genetics of Microenvironmental Sensitivity of Body Weight in Rainbow Trout (Oncorhynchus mykiss) Selected for Improved Growth

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    Microenvironmental sensitivity of a genotype refers to the ability to buffer against non-specific environmental factors, and it can be quantified by the amount of residual variation in a trait expressed by the genotype’s offspring within a (macro)environment. Due to the high degree of polymorphism in behavioral, growth and life-history traits, both farmed and wild salmonids are highly susceptible to microenvironmental variation, yet the heritable basis of this characteristic remains unknown. We estimated the genetic (co)variance of body weight and its residual variation in 2-year-old rainbow trout (Oncorhynchus mykiss) using a multigenerational data of 45,900 individuals from the Finnish national breeding programme. We also tested whether or not microenvironmental sensitivity has been changed as a correlated genetic response when genetic improvement for growth has been practiced over five generations. The animal model analysis revealed the presence of genetic heterogeneity both in body weight and its residual variation. Heritability of residual variation was remarkably lower (0.02) than that for body weight (0.35). However, genetic coefficient of variation was notable in both body weight (14%) and its residual variation (37%), suggesting a substantial potential for selection responses in both traits. Furthermore, a significant negative genetic correlation (−0.16) was found between body weight and its residual variation, i.e., rapidly growing genotypes are also more tolerant to perturbations in microenvironment. The genetic trends showed that fish growth was successfully increased by selective breeding (an average of 6% per generation), whereas no genetic change occurred in residual variation during the same period. The results imply that genetic improvement for body weight does not cause a concomitant increase in microenvironmental sensitivity. For commercial production, however, there may be high potential to simultaneously improve weight gain and increase its uniformity if both criteria are included in a selection index
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