541 research outputs found
Electronic and structural properties of vacancies on and below the GaP(110) surface
We have performed total-energy density-functional calculations using
first-principles pseudopotentials to determine the atomic and electronic
structure of neutral surface and subsurface vacancies at the GaP(110) surface.
The cation as well as the anion surface vacancy show a pronounced inward
relaxation of the three nearest neighbor atoms towards the vacancy while the
surface point-group symmetry is maintained. For both types of vacancies we find
a singly occupied level at mid gap. Subsurface vacancies below the second layer
display essentially the same properties as bulk defects. Our results for
vacancies in the second layer show features not observed for either surface or
bulk vacancies: Large relaxations occur and both defects are unstable against
the formation of antisite vacancy complexes. Simulating scanning tunneling
microscope pictures of the different vacancies we find excellent agreement with
experimental data for the surface vacancies and predict the signatures of
subsurface vacancies.Comment: 10 pages, 6 figures, Submitted to Phys. Rev. B, Other related
publications can be found at http://www.rz-berlin.mpg.de/th/paper.htm
Direct Determination of MCPD Fatty Acid Esters and Glycidyl Fatty Acid Esters in Vegetable Oils by LCâTOFMS
Analysis of MCPD esters and glycidyl esters in vegetable oils using the indirect method proposed by the DGF gave inconsistent results when salting out conditions were varied. Subsequent investigation showed that the method was destroying and reforming MCPD during the analysis. An LC time of flight MS method was developed for direct analysis of both MCPD esters and glycidyl esters in vegetable oils. The results of the LCâTOFMS method were compared with the DGF method. The DGF method consistently gave results that were greater than the LCâTOFMS method. The levels of MCPD esters and glycidyl esters found in a variety of vegetable oils are reported. MCPD monoesters were not found in any oil samples. MCPD diesters were found only in samples containing palm oil, and were not present in all palm oil samples. Glycidyl esters were found in a wide variety of oils. Some processing conditions that influence the concentration of MCPD esters and glycidyl esters are discussed
Zur Quantifizierung der RisikoprÀmien deutscher Versicherungsaktien im Kontext eines Multifaktorenmodells
Vorgestellt wird eine empirische Studie, welche den Zusammenhang zwischen Rendite und Risiko fĂŒr ein Sample deutscher Versicherungsaktien im Zeitraum 1975-1998 untersucht. Als Methode wurde ein Multifaktorenmodell mit makroökonomischen Faktoren verwendet. Je nach Untersuchungszeitraum belĂ€uft sich der Anteil der erklĂ€rten Varianz auf 9,29% bis 13,62%. Es konnte eine signifikanter negativer EinfluĂ zwischen der VerĂ€nderung des allgemeinen Zinsniveaus und den RisikoprĂ€mien von Versicherungsaktien identifiziert werden. Weiterhin ist Wechselkurses der DM zum US-Dollar signifikant
Between a rock and a hard place: Associations between Mentzos' âdilemmaâ, selfâreported interpersonal problems, and psychosocial functioning in individuals with nonâaffective psychoses
Primary aim of this study was to determine the extent and type of self-reported interpersonal problems in patients with non-affective psychoses and their impact on psychosocial functioning. Furthermore, we aimed to explore potential links with the psychodynamic construct of Stavros Mentzos' "psychotic dilemma", which describes an insufferable inner tension caused by an individual's struggle of being torn between "self-oriented" and "object-oriented" tendencies. In a cross-sectional study among 129 patients with non-affective psychoses, measures of cognition, symptom load and social functioning as well as a tentative, psychodynamic assessment of Mentzos' "dilemma" were obtained during a clinical research visit. Self-report data on interpersonal problems were gathered using the Inventory of Interpersonal Problems (IIP-64D) and compared with a German representative standard sample. Second, IIP-64D scores were compared between groups with or without Mentzos' "dilemma". Hierarchical regression analyses were performed to test for the impact of interpersonal problems on psychosocial functioning, while controlling for cognitive deficits and psychopathology. Results showed that IIP-64D scores differed significantly from healthy controls, except for "self-centred" and "intrusive" interpersonal styles. Participants with a potential "psychotic dilemma" scored significantly higher on the subscales: "domineering", "self-centred", "cold", and "socially avoidant" than the group without a "psychotic dilemma". The total amount of interpersonal problems, and particularly high scores on the IIP-64D "socially avoidant" subscale, predicted psychosocial dysfunction, whereas a "cold" interpersonal style had an opposite effect. In conclusion, specific interpersonal problems may predict psychotherapeutic outcome measures like psychosocial functioning and are partly compatible with the psychodynamic construct of Stavros Mentzos' "psychotic dilemma"
The reliability of product-specific eco-labels as an agrobiodiversity management instrument
This paper seeks to understand why multinationals prefer to launch a label specific to their own product and examines how
reliable these product-specific eco-labels are. A new methodology is applied to assess the extent to which eco-labels live
up to claims about their contribution to conservation and the sustainable use of agricultural biodiversity. Product-specific
eco-labels are considered as industry self-regulation and all three regulatory stages are studied: the planning, implementation
and outcome stage. There are major differences between the product specific eco-labels in the degree in which agrobiodiversity
management is part of the normative labeling schemes. Although there are some problems of reliability, such as transparency
in the implementation stage and the monitoring in the outcome stage, the degree of reliability of product-specific labels
is comparable with eco-labels of international labeling families. The conclusion is that only one of the product-specific
eco-labels examined here is reliable when examined in the light of all three stages. The main reason why multinationals establish
a product-specific eco-label instead of adopting one from an existing labeling family is that they want to profile themselves
as distinct from other companies. The unique character of a product-specific label creates a market opportunity for them
Adaptive plasticity of killifish (Fundulus heteroclitus) embryos: dehydration-stimulated development and differential aquaporin-3 expression
13 pages, 7 figures, 3 tablesEmbryos of the marine killifish Fundulus heteroclitus are adapted to survive aerially. However, it is unknown if they are able to control development under dehydration conditions. Here, we show that air-exposed blastula embryos under saturated relative humidity were able to stimulate development, and hence the time of hatching was advanced with respect to embryos continuously immersed in seawater. Embryos exposed to air at later developmental stages did not hatch until water was added, while development was not arrested. Air-exposed embryos avoided dehydration probably because of their thickened egg envelope, although it suffered significant evaporative water loss. The potential role of aquaporins as part of the embryo response to dehydration was investigated by cloning the aquaporin-0 (FhAqp0), -1a (FhAqp1a), and -3 (FhAqp3) cDNAs. Functional expression in Xenopus laevis oocytes showed that FhaAqp1a was a water-selective channel, whereas FhAqp3 was permeable to water, glycerol, and urea. Expression of fhaqp0 and fhaqp1a was prominent during organogenesis, and their mRNA levels were similar between water- and air-incubated embryos. However, fhaqp3 transcripts were highly and transiently accumulated during gastrulation, and the protein product was localized in the basolateral membrane of the enveloping epithelial cell layer and in the membrane of ingressing and migrating blastomers. Interestingly, both fhaqp3 transcripts and FhAqp3 polypeptides were downregulated in air-exposed embryos. These data demonstrate that killifish embryos respond adaptively to environmental desiccation by accelerating development and that embryos are able to transduce dehydration conditions into molecular responses. The reduced synthesis of FhAqp3 may be one of these mechanisms to regulate water and/or solute transport in the embryo.This study was supported by the European Commission New and Emerging
Science and Technologies (NEST) program (contract no. 012674-2 Sleeping
Beauty) and by a grant from the Spanish Ministry of Education and Science
(MEC; AGL2004-00316/ACU) to J. Cerda`. Participation of C. Zapater and F.
ChauvigneÂŽ was financed by a predoctoral fellowship from MEC (Spain) and by
the European Commission [Marie Curie Research Training Network Aqua
(glycero)porins, MRTN-CT-2006-035995], respectively.Peer reviewe
Transport emissions in Beijing: A scenario planning approach
This paper explores and analyses how to reduce smog-related air pollutants and carbon dioxide emissions generated by passenger transport systems in Beijing. In-depth surveys with experts and practitioners in China are used to examine the current business-as-usual projection for emissions in Beijing, the drivers and trends affecting current projections, and to develop alternative scenarios that might help reduce projected emissions significantly. These are based around different variants of population and migration growth and environmental stewardship. Current levels of smog caused by transport emissions are much higher in Beijing than internationally accepted safety standards, partly because of high levels of motorised traffic. Carbon dioxide emissions always tend to be overlooked because economic growth is prioritised. The sustainable model represents one of the best models for Beijing to follow; however, Beijing faces major challenges in becoming more environmentally sustainable over the next few years, mainly due to population growth and increased migration, even if there is powerful top-down government environmental stewardship. The aspiration to reduce smog-related air pollutants and carbon dioxide emissions in Beijing by implementing sustainable transport mitigation measures seems very ambitious; however, it is perhaps in this context that the real innovations in transport planning will emerge
The effectiveness of the Austrian disease management programme for type 2 diabetes: a cluster-randomised controlled trial
<p>Abstract</p> <p>Background</p> <p>Disease management programmes (DMPs) are costly and impose additional work load on general practitioners (GPs). Data on their effectiveness are inconclusive. We therefore conducted a cluster-randomised controlled trial to evaluate the effectiveness of the Austrian DMP for diabetes mellitus type 2 on HbA1c and quality of care for adult patients in primary care.</p> <p>Methods</p> <p>All GPs of Salzburg-province were invited to participate. After cluster-randomisation by district, all patients with diabetes type 2 were recruited consecutively from 7-11/2007. The DMP, consisting mainly of physician and patient education, standardised documentation and agreement on therapeutic goals, was implemented in the intervention group while the control group received usual care. We aimed to show superiority of the intervention regarding metabolic control and process quality. The primary outcome measure was a change in HbA1c after one year. Secondary outcomes were days in the hospital, blood pressure, lipids, body mass index (BMI), enrolment in patient education and regular guideline-adherent examination. Blinding was not possible.</p> <p>Results</p> <p>92 physicians recruited 1489 patients (649 intervention, 840 control). After 401 ± 47 days, 590 intervention-patients and 754 controls had complete data. In the intention to treat analysis (ITT) of all 1489 patients, HbA1c decreased 0.41% in the intervention group and 0.28% in controls. The difference of -0.13% (95% CI -0.24; -0.02) was significant at p = 0.026. Significance was lost in mixed models adjusted for baseline value and cluster-effects (adjusted mean difference -0.03 (95% CI -0.15; 0.09, p = 0.607). Of the secondary outcome measures, BMI and cholesterol were significantly reduced in the intervention group compared to controls in ITT after adjustments (-0.53 kg/mÂČ; 95% CI -1.03;-0.02; p = 0.014 and -0.10 mmol/l; 95% CI -0.21; -0.003; p = 0.043). Additionally, more patients received patient education (49.5% vs. 20.1%, p < 0.0001), eye- (71.0% vs. 51.2%, p < 0.0001), foot examinations (73.8% vs. 45.1%, p < 0.0001), and regular HbA1c checks (44.1% vs. 36.0%, p < 0.01) in the intervention group.</p> <p>Conclusion</p> <p>The Austrian DMP implemented by statutory health insurance improves process quality and enhances weight reduction, but does not significantly improve metabolic control for patients with type 2 diabetes mellitus. Whether the small benefit seen in secondary outcome measures leads to better patient outcomes, remains unclear.</p> <p>Trial Registration</p> <p>Current Controlled trials Ltd., ISRCTN27414162.</p
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