201 research outputs found

    Benefits of a marketing cooperative in transition agriculture: Mórakert purchasing and service co-operative

    Get PDF
    The paper analyses the potential benefits of marketing cooperatives in Hungary, employing a transaction cost economics framework. We found that the purchased quantity, the existence of contracts, flexibility and trust are the most important factors farmers consider when selling their products via a cooperative. The most striking result is that diversification has positive influences on the share of cooperatives in farmers’ sale. Furthermore, farmers with larger bargaining power have less willingness to sell their product to the cooperative. Surprisingly, asset specificity has rather negative effects on the share of cooperatives in members’ sales

    Current Status of Clinical Magnetic Resonance Imaging for Plaque Characterisation in Patients with Carotid Artery Stenosis

    Get PDF
    AbstractObjectiveThe article aims to provide an overview of the literature that assessed the agreement between magnetic resonance imaging (MRI) and histology for specific carotid plaque characteristics associated with vulnerability in terms of sensitivity and specificity.MethodsA systematic search strategy was conducted in MEDLINE and EMBASE databases resulting in 1084 articles. Finally, we included 17 papers. Due to variation in presentation, especially in MRI and histology methods, a pooled analysis could not be performed.ResultsTwo studies were performed on a 3.0-T MRI scanner; all other studies were performed on a 1.5-T scanner. Most performed sequences were two-dimensional (2D) and three-dimensional (3D) T1-weighted and all histology protocols varied slightly. Our results indicate that calcification, fibrous cap, intraplaque haemorrhage and lipid-rich necrotic cores can be identified with moderate-to-good sensitivity and specificity.ConclusionsBased on current literature, it appears premature for routine application of MRI as an imaging modality to assess carotid plaque characteristics associated with plaque vulnerability. Although MRI still holds promise, clinical application for plaque characterisation would require consensus regarding MRI settings and confirmation by histology. Predefined protocols for histology and MR imaging need to be established

    99mTc-sestamibi is a substrate for P-glycoprotein and the multidrug resistance-associated protein.

    Get PDF
    99mTc-sestamibi (99mTc-MIBI) is a substrate for the P-glycoprotein (P-gp) pump but it is not known whether it is a substrate for the multidrug resistance-associated protein (MRP) pump. Therefore, 99mTc-MIBI was evaluated in the GLC4 cell line and its doxorubicin-resistant MRP-, but not P-gp-, overexpressing GLC4/ADR sublines as well as in the S1 cell line and its MRP-transfected subline S1-MRP. 99mTc-MIBI concentration decreased in the GLC4/ADR sublines with increasing MRP overexpression and was lower in S1-MRP than in S1. 99mTc-MIBI plus vincristine increased 99mTc-MIBI concentration in GLC4 lines compared with 99mTc-MIBI alone. 99mTc-MIBI efflux raised with increasing MRP expression in the GLC4 lines. Glutathione depletion elevated 99mTc-MIBI concentration in GLC4/ADR150x. Cross resistance for 99Tc-MIBI, used to test cytotoxicity of the Tc compound, was observed in GLC4/ADR150x vs GLC4. 99Tc-MIBI induced a synergistic effect on vincristine cytotoxicity in GLC4/ADR150x. These results show that 99mTc-MIBI is involved in MRP-mediated efflux. The fact that 99mTc-MIBI efflux is influenced by MDR1 and MRP expression must be taken into account when this gamma-rays-emitting complex is tested for tumour efflux measurements

    Selection of workers and firm heterogeneity

    Get PDF
    A model based on differences between workers regarding their preferences for wage and leisure drives the heterogeneity of firms result. The more industrious workers are driven to small firms due to free riding in large firms. An industry consisting of small and large firms turns out to produce more output than an industry consisting of only large firms. Some comparative statics results are derived with respect to the size of large firms, the productivity difference between firms, and monitoring capabilities

    Renormalisation-theoretic analysis of non-equilibrium phase transitions I: The Becker-Doring equations with power law rate coefficients

    Full text link
    We study in detail the application of renormalisation theory to models of cluster aggregation and fragmentation of relevance to nucleation and growth processes. We investigate the Becker-Dorging equations, originally formulated to describe and analyse non-equilibrium phase transitions, and more recently generalised to describe a wide range of physicochemical problems. In the present paper we analyse how the systematic coarse-graining renormalisation of the \BD system of equations affects the aggregation and fragmentation rate coefficients. We consider the case of power-law size-dependent cluster rate coefficients which we show lead to only three classes of system that require analysis: coagulation-dominated systems, fragmentation-dominated systems and those where coagulation and fragmentation are exactly balanced. We analyse the late-time asymptotics associated with each class.Comment: 18 pages, to appear in J Phys A Math Ge

    Adverse prognosis of glioblastoma contacting the subventricular zone: Biological correlates

    Full text link
    INTRODUCTION: The subventricular zone (SVZ) in the brain is associated with gliomagenesis and resistance to treatment in glioblastoma. In this study, we investigate the prognostic role and biological characteristics of subventricular zone (SVZ) involvement in glioblastoma. METHODS: We analyzed T1-weighted, gadolinium-enhanced MR images of a retrospective cohort of 647 primary glioblastoma patients diagnosed between 2005-2013, and performed a multivariable Cox regression analysis to adjust the prognostic effect of SVZ involvement for clinical patient- and tumor-related factors. Protein expression patterns of a.o. markers of neural stem cellness (CD133 and GFAP-δ) and (epithelial-) mesenchymal transition (NF-κB, C/EBP-β and STAT3) were determined with immunohistochemistry on tissue microarrays containing 220 of the tumors. Molecular classification and mRNA expression-based gene set enrichment analyses, miRNA expression and SNP copy number analyses were performed on fresh frozen tissue obtained from 76 tumors. Confirmatory analyses were performed on glioblastoma TCGA/TCIA data. RESULTS: Involvement of the SVZ was a significant adverse prognostic factor in glioblastoma, independent of age, KPS, surgery type and postoperative treatment. Tumor volume and postoperative complications did not explain this prognostic effect. SVZ contact was associated with increased nuclear expression of the (epithelial-) mesenchymal transition markers C/EBP-β and phospho-STAT3. SVZ contact was not associated with molecular subtype, distinct gene expression patterns, or markers of stem cellness. Our main findings were confirmed in a cohort of 229 TCGA/TCIA glioblastomas. CONCLUSION: In conclusion, involvement of the SVZ is an independent prognostic factor in glioblastoma, and associates with increased expression of key markers of (epithelial-) mesenchymal transformation, but does not correlate with stem cellness, molecular subtype, or specific (mi)RNA expression patterns

    The emerging structure of the Extended Evolutionary Synthesis: where does Evo-Devo fit in?

    Get PDF
    The Extended Evolutionary Synthesis (EES) debate is gaining ground in contemporary evolutionary biology. In parallel, a number of philosophical standpoints have emerged in an attempt to clarify what exactly is represented by the EES. For Massimo Pigliucci, we are in the wake of the newest instantiation of a persisting Kuhnian paradigm; in contrast, Telmo Pievani has contended that the transition to an EES could be best represented as a progressive reformation of a prior Lakatosian scientific research program, with the extension of its Neo-Darwinian core and the addition of a brand-new protective belt of assumptions and auxiliary hypotheses. Here, we argue that those philosophical vantage points are not the only ways to interpret what current proposals to ‘extend’ the Modern Synthesis-derived ‘standard evolutionary theory’ (SET) entail in terms of theoretical change in evolutionary biology. We specifically propose the image of the emergent EES as a vast network of models and interweaved representations that, instantiated in diverse practices, are connected and related in multiple ways. Under that assumption, the EES could be articulated around a paraconsistent network of evolutionary theories (including some elements of the SET), as well as models, practices and representation systems of contemporary evolutionary biology, with edges and nodes that change their position and centrality as a consequence of the co-construction and stabilization of facts and historical discussions revolving around the epistemic goals of this area of the life sciences. We then critically examine the purported structure of the EES—published by Laland and collaborators in 2015—in light of our own network-based proposal. Finally, we consider which epistemic units of Evo-Devo are present or still missing from the EES, in preparation for further analyses of the topic of explanatory integration in this conceptual framework
    corecore