210 research outputs found
Defining the business ecosystem of peer-to-peer electricity trading
Purpose: The purpose of this paper is to introduce the value proposition and structure of the business ecosystem of peer-to-peer electricity trading through a future oriented approach. Design/Methodology/Approach: This study follows a qualitative approach. It conducts conceptual analyses by utilizing previously validated tools in similar contexts. First, different views on business ecosystems are introduced and an argument is made to justify an ecosystem perspective for peerto-peer electricity trading. Second, the value proposition of the peer-to-peer electricity trading ecosystem is identified by utilising a meta-model which consists of four elements: end customer value, business value (shareholder value), collaborative value (business value to the supply chain) and societal value (value creation in the supply chain and control of negative externalities). Third, based on the structural view of business ecosystems, the study identifies actors, positions, links, and activities in the traditional electricity trading. And last, (structural) changes of the ecosystem for peer-to-peer electricity trading are discussed. Findings: This paper elaborates the business ecosystem of peer-to-peer electricity trading and highlights the structural changes it imposes to the status quo. Practical and social implications: The ecosystem construct adds insights into actors’ ecosystem strategy regarding their business models for peer-to-peer electricity trading as well as into the governance of this type of trading. It provides a comprehensive view for policy makers. It enhances the research designs in detailed aspects of the peer-to-peer electricity trading by providing a wide lense. Originality/Value: The identified business ecosystem of peer-to-peer electricity trading provides a comprehensive, multi-stakeholder perspective to incorporate complexities and include externalities
Assessment of bovine tuberculosis risk factors based on nationwide molecular epidemiology
This assessment aimed to elaborate a statistical nationwide model for analyzing the space-time dynamics of bovine tuberculosis in search of potential risk factors that could be used to better target surveillance measures. A database comprising Mycobacterium bovis molecular profiles from all isolates obtained from Belgian outbreaks during the 1995-to-2006 period (n = 415) allowed the identification of a predominant spoligotype (SB0162). Various databases compiling 49 parameters to be tested were queried using a multiple stepwise logistic regression to assess bovine tuberculosis risk factors. Two isolate datasets were analyzed: the first included all Mycobacterium bovis isolates, while the second included only data related to the SB0162 type strain. When all Mycobacterium bovis isolates were included in the model, several risk factors were identified: history of bovine tuberculosis in the herd (P < 0.001), proximity of an outbreak (P < 0.001), cattle density (P < 0.001), and annual amplitude of mean middle-infrared temperature (P < 0.001). The approach restricted to the predominant SB0162 type strain additionally highlighted the proportion of movements from an infected area during the current year as a main risk factor (P = 0.009). This study identified several risk factors for bovine tuberculosis in cattle, highlighted the usefulness of molecular typing in the study of bovine tuberculosis epidemiology, and suggests a difference of behavior for the predominant type strain. It also emphasizes the role of animals' movements in the transmission of the disease and supports the importance of controlling trade movements
MLVA-16 typing of 295 marine mammal <i>Brucella</i> isolates from different animal and geographic origins identifies 7 major groups within <i>Brucella ceti</i> and <i>Brucella pinnipedialis</i>
BackgroundSince 1994, Brucella strains have been isolated from a wide range of marine mammals. They are currently recognized as two new Brucella species, B. pinnipedialis for the pinniped isolates and B. ceti for the cetacean isolates in agreement with host preference and specific phenotypic and molecular markers. In order to investigate the genetic relationships within the marine mammal Brucella isolates and with reference to terrestrial mammal Brucella isolates, we applied in this study the Multiple Loci VNTR (Variable Number of Tandem Repeats) Analysis (MLVA) approach. A previously published assay comprising 16 loci (MLVA-16) that has been shown to be highly relevant and efficient for typing and clustering Brucella strains from animal and human origin was used.Results294 marine mammal Brucella strains collected in European waters from 173 animals and a human isolate from New Zealand presumably from marine origin were investigated by MLVA-16. Marine mammal Brucella isolates were shown to be different from the recognized terrestrial mammal Brucella species and biovars and corresponded to 3 major related groups, one specific of the B. ceti strains, one of the B. pinnipedialis strains and the last composed of the human isolate. In the B. ceti group, 3 subclusters were identified, distinguishing a cluster of dolphin, minke whale and porpoise isolates and two clusters mostly composed of dolphin isolates. These results were in accordance with published analyses using other phenotypic or molecular approaches, or different panels of VNTR loci. The B. pinnipedialis group could be similarly subdivided in 3 subclusters, one composed exclusively of isolates from hooded seals (Cystophora cristata) and the two others comprising other seal species isolates.ConclusionThe clustering analysis of a large collection of marine mammal Brucella isolates from European waters significantly strengthens the current view of the population structure of these two species, and their relative position with respect to the rest of the Brucella genus. MLVA-16 is confirmed as being a rapid, highly discriminatory and reproducible method to classify Brucella strains including the marine mammal isolates. The Brucella2009 MLVA-16 genotyping database available at http://mlva.u-psud.fr is providing a detailed coverage of all 9 currently recognized Brucella species
The Relationship between Zinc Intake and Serum/Plasma Zinc Concentration in Children: A Systematic Review and Dose-Response Meta-Analysis
Recommendations for zinc intake during childhood vary widely across Europe. The EURRECA project attempts to consolidate the basis for the definition of micronutrient requirements, taking into account relationships among intake, status and health outcomes, in order to harmonise these recommendations. Data on zinc intake and biomarkers of zinc status reported in randomised controlled trials (RCTs) can provide estimates of dose-response relationships which may be used for underpinning zinc reference values. This systematic review included all RCTs of apparently healthy children aged 1–17 years published by February 2010 which provided data on zinc intake and biomarkers of zinc status. An intake-status regression coefficient was calculated for each individual study and calculated the overall pooled and SE using random effects meta-analysis on a double log scale. The pooled dose-response relationship between zinc intake and zinc status indicated that a doubling of the zinc intake increased the serum/plasma zinc status by 9%. This evidence can be utilised, together with currently used balance studies and repletion/depletion studies, when setting zinc recommendations as a basis for nutrition policies
Scheepsramp <i>Herald of Free Entreprise</i> dd. 6.3.1987: Monitoringresultaten van het gemeenschappelijk urgentieprogramma "Visserij"
Precursor reaction kinetics control compositional grading and size of CdSe1-xSx nanocrystal heterostructures
We report a method to control the composition and microstructure of CdSe1-xSx nanocrystals by the simultaneous injection of sulfide and selenide precursors into a solution of cadmium oleate and oleic acid at 240 degrees C. Pairs of substituted thio- and selenoureas were selected from a library of compounds with conversion reaction reactivity exponents (k(E)) spanning 1.3 x 10(-5) s(-1) to 2.0 x 10(-1) s(-1). Depending on the relative reactivity (k(Se)/k(S)), core/shell and alloyed architectures were obtained. Growth of a thick outer CdS shell using a syringe pump method provides gram quantities of brightly photoluminescent quantum dots (PLQY = 67 to 90%) in a single reaction vessel. Kinetics simulations predict that relative precursor reactivity ratios of less than 10 result in alloyed compositions, while larger reactivity differences lead to abrupt interfaces. CdSe1-xSx alloys (k(Se)/k(S) = 2.4) display two longitudinal optical phonon modes with composition dependent frequencies characteristic of the alloy microstructure. When one precursor is more reactive than the other, its conversion reactivity and mole fraction control the number of nuclei, the final nanocrystal size at full conversion, and the elemental composition. The utility of controlled reactivity for adjusting alloy microstructure is discussed
Small business economics: A perspective from The Netherlands
In the analysis of economic phenomena either within or across industries there is room for integrating the role of small business. This contribution can be made by aggregation or generalization of the findings at the meso level, which again are partly based upon analyses at the micro level.
The Netherlands has a long history in macro model building. A recent discussion among Dutch macro-economists considered the future of econometric model building at the macro level, and considered how best to improve this model building. The explicit integration of scale effects, however, was not mentioned. I am convinced that improvements in this respect are possible. In particular, I have in mind the role which small businesses play in certain areas such as wage structure, employment or investments. The dissection of macro prognoses into a small business component and a remaining component is a traditional practice in The Netherlands.1
Finally, there is much concern in The Netherlands for the calculation of regulatory effects, decomposed into effects for small and large businesses. If anywhere in the world there is a solid foundation for studying scale effects in both macro and sectoral models, it most certainly has been in The Netherlands. There is a strong tradition of macro-econometric model building; groups of econometricians specialized in small business research exist; Dutch policymakers show concern and the required research apparatus is available
Clinical Pharmacokinetics and Dose Recommendations for Posaconazole in Infants and Children.
OBJECTIVES: The objectives of this study were to investigate the population pharmacokinetics of posaconazole in immunocompromised children, evaluate the influence of patient characteristics on posaconazole exposure and perform simulations to recommend optimal starting doses. METHODS: Posaconazole plasma concentrations from paediatric patients undergoing therapeutic drug monitoring were extracted from a tertiary paediatric hospital database. These were merged with covariates collected from electronic sources and case-note reviews. An allometrically scaled population-pharmacokinetic model was developed to investigate the effect of tablet and suspension relative bioavailability, nonlinear bioavailability of suspension, followed by a step-wise covariate model building exercise to identify other important sources of variability. RESULTS: A total of 338 posaconazole plasma concentrations samples were taken from 117 children aged 5Â months to 18Â years. A one-compartment model was used, with tablet apparent clearance standardised to a 70-kg individual of 15Â L/h. Suspension was found to have decreasing bioavailability with increasing dose; the estimated suspension dose to yield half the tablet bioavailability was 99Â mg/m2. Diarrhoea and proton pump inhibitors were also associated with reduced suspension bioavailability. CONCLUSIONS: In the largest population-pharmacokinetic study to date in children, we have found similar covariate effects to those seen in adults, but low bioavailability of suspension in patients with diarrhoea or those taking concurrent proton pump inhibitors, which may in particular limit the use of posaconazole in these patients
Evaluation of a multiplex PCR assay (Bruce-ladder) for molecular typing of all <i>Brucella</i> species, including the vaccine strains
An evaluation of a multiplex PCR assay (Bruce-ladder) was performed in seven laboratories using 625 Brucella strains from different animal and geographical origins. This robust test can differentiate in a single step all of the classical Brucella species, including those found in marine mammals and the S19, RB51, and Rev.1 vaccine strains
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