361 research outputs found

    Using cost benefit analysis as a learning process: identifying interventions for improving communication and trust

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    Integrated transportation plans require assessment approaches that can adequately support their multi-dimensional, context-specific needs. The suitability of cost benefit analysis (CBA) for answering this need has been studied in recent research: an analysis of participant perceptions in the Netherlands showed several problematic process issues when assessing integrated transportation plans with CBA (Beukers et al., 2012). CBA was perceived by the participants as a final test, in contrast to the desired outcome of using CBA as a learning tool to optimize the plans. Furthermore, the two main groups of participants (plan owners and evaluators) appeared to hold different and sometimes clashing rationales. This clash was expressed through lack of communication and mutual trust. Using a literature review of the fields of deliberative planning and organizational learning to explore how to improve communication and build trust, this paper provides a deeper understanding of the process issues at hand and contends that strong communication and trust between plan owners and evaluators are crucial conditions for employing CBA as a learning tool. Finally, based on these theoretical insights, this paper proposes an approach for supporting the practical use of CBA as a learning tool

    Percepties op het MKBA proces

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    Dit artikel richt zich op het MKBA proces en de problemen die daarin worden ervaren. Door onderzoek naar het proces kan de kennisleemte daarover worden verkleind. In diepte interviews en focusgroep sessies zijn verschillende MKBA betrokkenen gevraagd naar hun percepties op het proces. Daaruit volgt dat de ervaringen van betrokkenen zeer verschillend zijn. Of iets als een probleem wordt ervaren, hangt samen met de rol in het proces. De overkoepelende problemen worden gevonden in de ervaringen van een oordelend gebruik van de MKBA waarvoor het instrument niet bedoeld en niet toegerust is. Ook blijkt het proces gekenmerkt te worden door ervaringen van gebrekkige communicatie en wantrouwen, zowel onderling als naar het instrument en of het te analyseren plan. De grondige analyse van het MKBA proces biedt handreikingen voor verbetering en vervolgonderzoek

    Some remarks on the visible points of a lattice

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    We comment on the set of visible points of a lattice and its Fourier transform, thus continuing and generalizing previous work by Schroeder and Mosseri. A closed formula in terms of Dirichlet series is obtained for the Bragg part of the Fourier transform. We compare this calculation with the outcome of an optical Fourier transform of the visible points of the 2D square lattice.Comment: 9 pages, 3 eps-figures, 1 jpeg-figure; updated version; another article (by M. Baake, R. V. Moody and P. A. B. Pleasants) with the complete solution of the spectral problem will follow soon (see math.MG/9906132

    MEN-2 Syndrome: The Value of Screening and Central Registration; A Study of Six Kindreds in The Netherlands

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    Since 1975, six families with the MEN-2A syndrome including 66 patients have been identified in The Netherlands. All these patients underwent thyroidectomy for C-cell hyperplasia and/or medullary thyroid carcinoma (MTC); eight were symptomatic (Group A), 51 were relatives of patients found to be affected (Group B), and seven had had a negative screening test that became positive (Group C). To assess the effect of screening, we compared these groups with respect to the occurrence of metastatic MTC at thyroidectomy and the results of the postoperative calcitonin (CT) tests. We found that 87% of Group A, 37% of Group B; and none of Group C had metastatic disease at surgery. The cure rates in these three groups with MEN-2A, as determined by stimulated CT measurement, was 0%, 51%, and 100%, respectively. From these results it may be concluded that screening can lead to the detection of MTC at an earlier stage which in turn could permit curative treatment and improvement of both prognosis and life expectancy. The need for supervision of affected families by central registration to guarantee the continuity of screening is stressed

    A novel chemogenomics analysis of G protein-coupled receptors (GPCRs) and their ligands: a potential strategy for receptor de-orphanization.

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    BACKGROUND: G protein-coupled receptors (GPCRs) represent a family of well-characterized drug targets with significant therapeutic value. Phylogenetic classifications may help to understand the characteristics of individual GPCRs and their subtypes. Previous phylogenetic classifications were all based on the sequences of receptors, adding only minor information about the ligand binding properties of the receptors. In this work, we compare a sequence-based classification of receptors to a ligand-based classification of the same group of receptors, and evaluate the potential to use sequence relatedness as a predictor for ligand interactions thus aiding the quest for ligands of orphan receptors. RESULTS: We present a classification of GPCRs that is purely based on their ligands, complementing sequence-based phylogenetic classifications of these receptors. Targets were hierarchically classified into phylogenetic trees, for both sequence space and ligand (substructure) space. The overall organization of the sequence-based tree and substructure-based tree was similar; in particular, the adenosine receptors cluster together as well as most peptide receptor subtypes (e.g. opioid, somatostatin) and adrenoceptor subtypes. In ligand space, the prostanoid and cannabinoid receptors are more distant from the other targets, whereas the tachykinin receptors, the oxytocin receptor, and serotonin receptors are closer to the other targets, which is indicative for ligand promiscuity. In 93% of the receptors studied, de-orphanization of a simulated orphan receptor using the ligands of related receptors performed better than random (AUC > 0.5) and for 35% of receptors de-orphanization performance was good (AUC > 0.7). CONCLUSIONS: We constructed a phylogenetic classification of GPCRs that is solely based on the ligands of these receptors. The similarities and differences with traditional sequence-based classifications were investigated: our ligand-based classification uncovers relationships among GPCRs that are not apparent from the sequence-based classification. This will shed light on potential cross-reactivity of GPCR ligands and will aid the design of new ligands with the desired activity profiles. In addition, we linked the ligand-based classification with a ligand-focused sequence-based classification described in literature and proved the potential of this method for de-orphanization of GPCRs.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

    Super congruences and Euler numbers

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    Let p>3p>3 be a prime. We prove that k=0p1(2kk)/2k=(1)(p1)/2p2Ep3(modp3),\sum_{k=0}^{p-1}\binom{2k}{k}/2^k=(-1)^{(p-1)/2}-p^2E_{p-3} (mod p^3), k=1(p1)/2(2kk)/k=(1)(p+1)/28/3pEp3(modp2),\sum_{k=1}^{(p-1)/2}\binom{2k}{k}/k=(-1)^{(p+1)/2}8/3*pE_{p-3} (mod p^2), k=0(p1)/2(2kk)2/16k=(1)(p1)/2+p2Ep3(modp3)\sum_{k=0}^{(p-1)/2}\binom{2k}{k}^2/16^k=(-1)^{(p-1)/2}+p^2E_{p-3} (mod p^3), where E_0,E_1,E_2,... are Euler numbers. Our new approach is of combinatorial nature. We also formulate many conjectures concerning super congruences and relate most of them to Euler numbers or Bernoulli numbers. Motivated by our investigation of super congruences, we also raise a conjecture on 7 new series for π2\pi^2, π2\pi^{-2} and the constant K:=k>0(k/3)/k2K:=\sum_{k>0}(k/3)/k^2 (with (-) the Jacobi symbol), two of which are k=1(10k3)8k/(k3(2kk)2(3kk))=π2/2\sum_{k=1}^\infty(10k-3)8^k/(k^3\binom{2k}{k}^2\binom{3k}{k})=\pi^2/2 and \sum_{k>0}(15k-4)(-27)^{k-1}/(k^3\binom{2k}{k}^2\binom{3k}k)=K.$

    Controlling supercurrents and their spatial distribution in ferromagnets

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    Quantum Matter and Optic

    On the Completeness of the Set of Classical W-Algebras Obtained from DS Reductions

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    We clarify the notion of the DS --- generalized Drinfeld-Sokolov --- reduction approach to classical W{\cal W}-algebras. We first strengthen an earlier theorem which showed that an sl(2)sl(2) embedding SG{\cal S}\subset {\cal G} can be associated to every DS reduction. We then use the fact that a \W-algebra must have a quasi-primary basis to derive severe restrictions on the possible reductions corresponding to a given sl(2)sl(2) embedding. In the known DS reductions found to date, for which the \W-algebras are denoted by WSG{\cal W}_{\cal S}^{\cal G}-algebras and are called canonical, the quasi-primary basis corresponds to the highest weights of the sl(2)sl(2). Here we find some examples of noncanonical DS reductions leading to \W-algebras which are direct products of WSG{\cal W}_{\cal S}^{\cal G}-algebras and `free field' algebras with conformal weights Δ{0,12,1}\Delta \in \{0, {1\over 2}, 1\}. We also show that if the conformal weights of the generators of a W{\cal W}-algebra obtained from DS reduction are nonnegative Δ0\Delta \geq 0 (which isComment: 48 pages, plain TeX, BONN-HE-93-14, DIAS-STP-93-0

    Pontine capillary telangiectasia as visualized on MR imaging causing a clinical picture resembling basilar-type migraine: a case report

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    A case of presumed pontine capillary telangiectasia in an 18-year-old woman with a clinical diagnosis of basilar-type migraine is reported. Since both are very rare diagnoses, this case provides some evidence to suggest that pontine capillary telangiectasia might cause a clinical picture resembling basilar-type migraine
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