1,240 research outputs found
Charge density study with the Maximum Entropy Method on model data of silicon. A search for non-nuclear attractors
1990 Sakata and Sato applied the maximum entropy method (MEM) to a set of structure factors measured earlier by Saka and Kato with the Pendellösung method. They found the presence of non-nuclear attractors, i.e., maxima in the density between two bonded atoms. We applied the MEM to a limited set of Fourier data calculated from a known electron density distribution (EDD) of silicon. The EDD of silicon was calculated with the program ADF-BAND. This program performs electronic structure calculations, including periodicity, based on the density functional theory of Hohenberg and Kohn. No non-nuclear attractor between two bonded silicon atoms was observed in this density. Structure factors were calculated from this density and the same set of structure factors that was measured by Saka and Kato was used in the MEM analysis. The EDD obtained with the MEM shows the same non-nuclear attractors that were later obtained by Sakata and Sato. This means that the non-nuclear attractors in silicon are really an artefact of the MEM
Time to pregnancy and occupational exposure to pesticides in fruit growers in The Netherlands.
Minimally invasive pediatric surgery: Increasing implementation in daily practice and residentâs training
Background: In 1998, the one-year experience in minimally invasive abdominal surgery in children at a pediatric training center was assessed. Seven years later, we determined the current status of pediatric minimally invasive surgery in daily practice and surgical training. Methods: A retrospective review was undertaken of all children with intra-abdominal operations performed between 1 January 2005 and 31 December 2005. Results: The type of operations performed ranged from common interventions to demanding laparoscopic procedures. 81% of all abdominal procedures were performed laparoscopically, with a complication rate stable at 6.9%, and conversion rate decreasing from 10% to 7.4%, compared to 1998. There were six new advanced laparoscopic procedures performed in 2005 as compared to 1998. The children in the open operated group were significantly smaller and younger than in the laparoscopic group (p < 0.001 and p = 0.001, respectively). The majority (64.2%) of the laparoscopic procedures were performed by a trainee. There was no difference in the operating times of open versus laparoscopic surgery, or of procedures performed by trainees versus staff surgeons. Laparoscopy by trainees did not have a negative impact on complication or conversion rates. Conclusions: Laparoscopy is an established approach in abdominal procedures in children, and does not hamper surgical training
Micro-level economic factors and incentives in Children's energy balance related behaviours findings from the ENERGY European cross-section questionnaire survey
<p>Abstract</p> <p>Background</p> <p>To date, most research on obesogenic environments facing school children has focused on physical and socio-cultural environments. The role of economic factors has been investigated to a much lesser extent. Our objective was to explore the association of micro-level economic factors and incentives with sports activities and intake of soft drinks and fruit juice in 10-12âyear-old school children across Europe, and to explore price sensitivity in childrenâs soft drink consumption and correlates of this price sensitivity.</p> <p>Methods</p> <p>Data for the study originate from a cross-sectional survey undertaken in seven European countries (Belgium, Greece, Hungary, Netherlands, Norway, Slovenia and Spain) in 2010 among 10-12âyear-old school children and their parents. In total, 7234 child questionnaires and 6002 parent questionnaires were completed. The child questionnaire included questions addressing self-reported weekly intake of soft drinks and fruit juices and time spent on sports activities, perception of parental support for sports activities, use of pocket money for soft drinks and perceived price responsiveness. Parent questionnaires included questions addressing the role of budget and price considerations in decisions regarding childrenâs sports activities, soft drink consumption, home practices and rules and socio-demographic background variables. Data were analysed using multiple linear regression and discrete-choice (ordered probit) modelling.</p> <p>Results</p> <p>Economic factors were found to be associated with childrenâs sports participation and sugary drink consumption, explaining 27% of the variation in time for sports activities, and 27% and 12% of the variation in the childrenâs soft drink and juice consumption, respectively. Parentsâ financial support was found to be an important correlate (Beta =0.419) of childrenâs sports activities. Childrenâs pocket money was a strong correlate (Beta =21.034) of soft drink consumption. The majority of the responding children reported to expect that significantly higher prices of soft drinks would lead them to buy less soft drinks with their own pocket money, but a majority of parents did not expect higher soft drink prices to reduce their childrenâs soft drink consumption.</p> <p>Conclusions</p> <p>We conclude that economic factors, especially parentsâ financial support and amount of pocket money, appear to be of importance for childrenâs sports participation and soft drink consumption, respectively.</p
Foreign Direct Investments in Business Services: Transforming the VisegrĂĄd Four Region into a Knowledge-based Economy?
Foreign direct investments (FDIs) in the service sector are widely attributed an important role in bringing more skill-intensive activities into the Visegrad Four (V4). This regionâcomprising Poland, the Czech Republic, Hungary and Slovakiaârelied heavily on FDIs in manufacturing, which was often found to generate activities with limited skill content. This contribution deconstructs the chaotic concept of âbusiness servicesâ by analysing the actual nature of service sector activities outsourced and offshored to the V4. Using the knowledge-based economy (KBE) as a benchmark, the paper assesses the potential of service sector outsourcing in contributing to regional competitiveness by increasing the innovative capacity. It also discusses the role of state policies towards service sector FDI (SFDI). The analysis combines data obtained from case studies undertaken in service sector outsourcing projects in V4 countries. Moreover, it draws on interviews with senior employees of investment promotion agencies and publicly available data and statistics on activities within the service sector in the region. It argues that the recent inward investments in business services in the V4 mainly utilize existing local human capital resources, and their contribution to the development of the KBE is limited to employment creation and demand for skilled labour
Ab initio simulations of liquid NaSn alloys: Zintl anions and network formation
Using the Car-Parrinello technique, ab initio molecular dynamics simulations
are performed for liquid NaSn alloys in five different compositions (20, 40,
50, 57 and 80 % sodium). The obtained structure factors agree well with the
data from neutron scattering experiments. The measured prepeak in the structure
factor is reproduced qualitatively for most compositions. The calculated and
measured positions of all peaks show the same trend as function of the
composition.\\ The dynamic simulations also yield information about the
formation and stability of Sn clusters (Zintl anions) in the liquid. In our
simulations of compositions with 50 and 57 % sodium we observe the formation of
networks of tin atoms. Thus, isolated tin clusters are not stable in such
liquids. For the composition with 20 % tin only isolated atoms or dimers of tin
appear, ``octet compounds'' of one Sn atom surrounded by 4 Na atoms are not
observed.Comment: 12 pages, Latex, 3 Figures on reques
Locating regional health policy: Institutions, politics, and practices
Poverty reduction and health became central in the agendas of Southern regional organisations in the last two decades. Yet, little is known about how these organisations address poverty, inclusion and social inequality, and how Southern regional formations are engaging in power constellations, institutions, processes, interests and ideological positions within different spheres of governance. This article reviews academic literatures spanning global social policy, regional studies and diplomacy studies, and the state of knowledge and understanding of the âplaceâ of regional actors in health governance as a global political practice therein. It identifies theoretical and thematic points of connection between disparate literatures and how these can be bridged through research focusing on the social policies of regional organisations and regional integration processes. This framework hence locates the contributions of each of the research articles of this Special Issue of Global Social Policy on the regional dimension of health policy and diplomacy in relation to Southern Africa and South America. It also highlights the ways in which the articles bring new evidence about how social relations of welfare are being (re)made over larger scales and how regional actors may initiate new norms to improve health rights in international arenas engaging in new forms of âregionalâ diplomacy
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