1,086 research outputs found
Recommended from our members
The partial oxidation of methane over Pd/Al2O3 catalyst nanoparticles studied in-situ by near ambient-pressure x-ray photoelectron spectroscopy
Near ambient-pressure X-ray photoelectron spectroscopy (NAP-XPS) is used to study the chemical state of methane oxidation catalysts in-situ. Al2O3{supported Pd catalysts are prepared with different particle sizes ranging from 4 nm to 10 nm. These catalysts were exposed to conditions similar to those used in the partial oxidation of methane (POM) to syn-gas and simultaneously monitored by NAP-XPS and mass spectrometry. NAP-XPS data show changes in the oxidation state of the palladium as the temperature in-
creases, from metallic Pd0 to PdO, and back to Pd0.
Mass spectrometry shows an increase in CO production whilst the Pd is in the oxide phase, and the metal is reduced back under presence of newly formed H2. A particle size effect is observed, such that CH4 conversion starts at lower temperatures with larger sized
particles from 6 nm to 10 nm. We find that all nanoparticles begin CH4 conversion at lower temperatures than polycrystalline Pd foil
Cross-species amplification of 36 cyprinid microsatellite loci in Phoxinus phoxinus (L.) and Scardinius erythrophthalmus (L.)
<p>Abstract</p> <p>Background</p> <p>To conduct phylogeographic or population genetic studies, an adequate number of DNA markers for the focal species are required. Due to severe unavailability of genotype markers of any kind for the species Eurasian minnow (<it>Phoxinus phoxinus </it>L.) and rudd (<it>Scardinius erythrophthalmus </it>L.), we set out to attempt cross-amplification of a set of microsatellite loci from related species.</p> <p>Findings</p> <p>We tested 36 cyprinid microsatellite loci for cross-species amplification in minnow and rudd. Fifteen species-locus combinations produced amplifications in minnow, seven being polymorphic, while 18 combinations amplified in rudd, nine of these being polymorphic.</p> <p>Conclusions</p> <p>The positive cross-species amplifications present potential contributions to the establishment of genetic marker sets for population genetics studies of the two focal species.</p
Gender differences in health care use among the elderly population in areas of Norway and Finland. A cross-sectional analysis based on the HUNT study and the FINRISK Senior Survey
Background: The aim of the study was to examine gender differences in the self-reported use of
health care services by the elderly in rural and metropolitan areas of two Nordic countries with
slightly different health care systems: Finland and Norway.
Methods: Population based, cross-sectional surveys conducted in Nord-Tröndelag Norway
(1995–97) and in rural and metropolitan areas of Finland (1997) were employed. In the Norwegian
data, a total of 7,919 individuals, aged 65–74 years old were included, and the Finnish data included
1,500 individuals. The outcome variables comprised whether participants had visited a general
practitioner or a specialist, or had received hospital care or physiotherapy during the past 12
months. Gender differences in the use of health care services were analysed by multiple logistic
regression, controlling for health status and socio-demographic characteristics.
Results: In Norway, elderly women visited a specialist or were hospitalised less often than men.
In Finland, elderly women used all health care services except hospital care more often than men.
In Norway, less frequent use of specialist care by women was not associated with self-reported
health or chronic diseases.
Conclusion: The findings revealed differences in self-reported use of secondary care among
different genders in areas of Norway and Finland.© 2006 Suominen-Taipale et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
A review of fatigue in fishermen: a complicated and underprioritised area of research
Background: Fatigue in fishing has been a highly underprioritised area of research, even though fatigue has been found to be the largest single contributing factor in accidents.Aim: The aim of this article/paper is to provide an overview of the research conducted on fatigue in fishermen up to date, in order to establish a starting point for further research in this area.Materials and methods: The review is mainly based on journal articles from PubMed, Google Scholar, International Maritime Health, Science Direct and some relevant articles links were also followed.Results: The research revealed that only 5 articles have been published concerning fatigue in fishermen.The articles all confirmed that fatigue is a serious health and safety issue among fishermen, and that further research therefore is warranted.Conclusions: Only 2 of the 5 studies of fishermen’s fatigue used objective measures and in one of these, the sample size was small (n = 19), effectively limiting the statistical analysis and its application. Further research using larger samples is needed, preferably with a mix of objective and subjective measures, where of some of the questions should be scenario based and some should be from standardised questionnaires. Greater understanding is also needed to assess how much of the variance in fatigue is attributable to e.g. length of trip, hours of work without rest, and type of job and specific tasks. A greater understanding of the similarities and differences between acute and long-term fatigue is also needed
Exome-wide association analysis reveals novel coding sequence variants associated with lipid traits in Chinese
published_or_final_versio
Technician components and requirements model for the formation and management of cooperation networks among civil construction companies
A indústria da Construção Civil possui um modo de operação semelhante ao das organizações virtuais, mas de forma não estruturada, deixando de proporcionar vantagens competitivas. Para tanto, o artigo propõe um Modelo de Requisitos e Componentes Técnicos, baseado na metodologia EKD (Enterprise Knwoledge Development), para auxiliar a formação e gerência de redes entre empresas da construção civil. Para a elaboração do modelo proposto, foi conduzida uma análise dos projetos internacionais mais relevantes no setor da construção além de estudo de casos contendo sete obras a fim de detectar seus objetivos e pontos falhos a serem reestruturados e adaptados para a indústria da construção civil brasileira. Não obstante, o modelo proposto baseou-se em uma adaptação das melhores práticas de uma arquitetura de referência para redes. Como resultado, a proposição viabiliza uma visão clara dos requisitos necessários, explora a necessidade de intensa comunicação e troca de informações, além de contribuir com pesquisas futuras no que tange a um futuro desenvolvimento de sistema de informação direcionado para este segmento econômico.The operational method of civil construction can be analyzed by the outlook of virtual organizations, however not yet structuralized, hence not providing competitive advantages. Thus, this article considers a Technical Components and Requirements Model, based on EKD methodology (Enterprise Knowledge Development), to assist in the formation and management of networks in civil construction companies. For the elaboration of the considered model, an analysis of the most important international construction projects was conducted, in addition to a case study from seven construction projects in order to detect their goals and defective points, to then be reorganized and adapted to the Brazilian civil construction industry. Moreover, the considered model was also based on an adaptation of reference architecture for civil construction networks. As a result, the proposal makes possible, to the stakeholders, a clear view of the necessary requirements, exploring the necessity of intense communication and exchange of information, besides contributing to future research works regarding a future development of an information system directed for this economic segment
Tight-binding parameters for charge transfer along DNA
We systematically examine all the tight-binding parameters pertinent to
charge transfer along DNA. The molecular structure of the four DNA bases
(adenine, thymine, cytosine, and guanine) is investigated by using the linear
combination of atomic orbitals method with a recently introduced
parametrization. The HOMO and LUMO wavefunctions and energies of DNA bases are
discussed and then used for calculating the corresponding wavefunctions of the
two B-DNA base-pairs (adenine-thymine and guanine-cytosine). The obtained HOMO
and LUMO energies of the bases are in good agreement with available
experimental values. Our results are then used for estimating the complete set
of charge transfer parameters between neighboring bases and also between
successive base-pairs, considering all possible combinations between them, for
both electrons and holes. The calculated microscopic quantities can be used in
mesoscopic theoretical models of electron or hole transfer along the DNA double
helix, as they provide the necessary parameters for a tight-binding
phenomenological description based on the molecular overlap. We find that
usually the hopping parameters for holes are higher in magnitude compared to
the ones for electrons, which probably indicates that hole transport along DNA
is more favorable than electron transport. Our findings are also compared with
existing calculations from first principles.Comment: 15 pages, 3 figures, 7 table
Disease mapping of early- and late-stage cancer to monitor inequalities in early detection: a study of cutaneous malignant melanoma
We consider disease mapping of early- and late-stage cancer, in order to identify and monitor inequalities in early detection. Our method is demonstrated by mapping cancer incidence at high geographical resolution using data on 10,302 cutaneous malignant melanoma (CMM) cases within the 3.7 million population of South-West Sweden. The cases were geocoded into small-areas, each with a population size between 600 and 2600 and accessible socio-demographic data. Using the disease mapping application Rapid Inquiry Facility (RIF) 4.0, we produced regional maps to visualise spatial variations in stage I, II and III–IV CMM incidences, complemented by local maps to explore the variations within two urban areas. Pronounced spatial disparities in stage I CMM incidence were revealed by the regional and local maps. Stage I CMM incidence was markedly higher in wealthier small-areas, in particular within each urban area. A twofold higher stage I incidence was observed, on average, in the wealthiest small-areas (upper quintile) than in the poorest small-areas (lower quintile). We identified in the regional map of stage III–IV CMM two clusters of higher or lower than expected late-stage incidences which were quite distinct from those identified for stage I. In conclusion, our analysis of CMM incidences supported the use of this method of cancer stage incidence mapping for revealing geographical and socio-demographic disparities in cancer detection
Suicidal ideation in relation to disordered eating, body size and weight perception: a cross-sectional study of a Norwegian adolescent population: the HUNT study
Objective We conducted a population-based study on a sample of more than 7000 adolescents where we examined the associations between suicidal ideation (SI) and disordered eating (DE) and its related traits.
Design Cross-sectional.
Settings Data were derived from two Norwegian population-based cohorts, the Young-HUNT1 (1995–1997) and Young-HUNT3 (2006–2008) from the county of Nord-Trøndelag, Norway.
Participants A total of 7268 adolescents (15–19 years) who had completed self-reported questionnaires including items on SI, DE, body size and weight perception were included.
Primary outcome measures ORs for SI given DE, body size or weight perception. Analyses were performed in multivariate logistic regression models.
Results The prevalence of SI was 23.1% in total population. Both girls and boys who reported DE, evaluated their body size as not ‘about the same as others’ or were ‘unhappy about their weight’ had between twofold to fivefold increase in odds for SI; these incremental risks were observed independent of sex, age, body mass index and socioeconomic status. We observed higher odds for SI among boys.
Conclusions Our findings suggest a clear association between SI and DE and its associated traits, in both genders but especially in males. Special attention should be paid on early detection of DE traits among adolescents.publishedVersio
- …