247 research outputs found

    Besturen in commissie

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    Nederland bestuurt in commissie. Bepaald niet iedereen is daar gelukkig mee. Regelmatig klinkt de roep om het mes te zetten in het aantal commissies (zie bijvoorbeeld Duyvendak en Van de Koppel 2005).1 Commissies zouden vooral dienen als werkverschaffing voor bestuurders van weleer. Ze worden opgevat als synoniem voor alles wat stroperig is, geen resultaat oplevert en afbreuk doet aan het politieke primaat. In dat licht verzocht de Tweede Kamer al eerder per motie het aantal onderzoeks- en adviescommissies te beperken.2 De minister van Bestuurlijke Vernieuwing uit het vorige kabinet, Alexander Pechtold, liet weten ‘gek te worden van adviescommissies’ toen hij een bundel met opstellen over het verschijnsel kreeg aangeboden.3 Diverse ministers uit eerdere kabinetten hebben hun tanden er al op stukgebeten, maar een beroep doen op commissies lijkt onuitroeibaar als fenomeen. Dat vraagt om een nader onderzoek naar ‘besturen in commissie’. Want wat weten we er eigenlijk precies vanaf? Hoeveel commissies worden er ingesteld? Waarom worden ze ingesteld? Wie wil afrekenen met de veelheid aan commissies die Nederland kent, doet er goed aan zich eerst te verdiepen in de redenen die er zijn om keer op keer toch weer van hun diensten gebruik te maken

    Structure of 10Be from the 12C 12C,14O 10Be reaction

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    The 12C 12C,14O two proton pick up reaction has been measured at 211.4 MeV incident energy to study the structure of states of 10Be up to excitation energies of 12 MeV. The measured partial angular distributions show pronounced oscillatory shapes, which were described by coupled reaction channels calculations. Spin parity assignments could be derived from these characteristic shapes and two definite assignments have been made. The state at 11.8 MeV has been identified as the 4 member of the ground state band, and the state at 10.55 MeV is assigned J pi 3 . At 5.96 MeV only the 1 1 member of the known 2 2 1 1 doublet is populated. The angular distribution of the peak at 9.50 MeV, which consists of several unresolved states, has been unfolded using contributions from known states at 9.56 MeV, 2 , and 9.27 MeV, 4 . The inclusion of a state at 9.4 MeV reported by Daito it et al. from the 10B t,3He 10Be reaction and tentatively assigned 3 improved the fit considerably. A K 2 band is formed with the 2 2 state as the band head and the 3 state as the second member. The structures of the K pi 0 1, 2 2, and 1 1 bands are discusse

    Particle-gamma coincidences and coplanarity in the 32S+24Mg^{32}S+^{24}Mg binary reaction

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    The reaction 32S (165.4 MeV) + 24Mg is studied using the binary reaction spec- trometer (BRS) coupled to the Euroball germanium array. Particle-particle-gamma and particle-gamma-gamma coincidences have been examined. The Z-identification, position and energy information for binary reaction products are shown together with the Doppler-shift corrected gamma-rays emitted from the fragments. Recent reports of evi- dence for hyper-deformation from angular correlations in similar data are also in- vestigated. Analogous out-of-plane angular correlations are observed but attributed to reactions with the target contaminants 16O and 12C

    Role of Medium- and Short-Chain L-3-Hydroxyacyl-CoA Dehydrogenase in the Regulation of Body Weight and Thermogenesis

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    Dysregulation of fatty acid oxidation plays a pivotal role in the pathophysiology of obesity and insulin resistance. Medium- and short-chain-3-hydroxyacyl-coenzyme A (CoA) dehydrogenase (SCHAD) (gene name, hadh) catalyze the third reaction of the mitochondrial β-oxidation cascade, the oxidation of 3-hydroxyacyl-CoA to 3-ketoacyl-CoA, for medium- and short-chain fatty acids. We identified hadh as a putative obesity gene by comparison of two genome-wide scans, a quantitative trait locus analysis previously performed in the polygenic obese New Zealand obese mouse and an earlier described small interfering RNA-mediated mutagenesis in Caenorhabditis elegans. In the present study, we show that mice lacking SCHAD (hadh(−/−)) displayed a lower body weight and a reduced fat mass in comparison with hadh(+/+) mice under high-fat diet conditions, presumably due to an impaired fuel efficiency, the loss of acylcarnitines via the urine, and increased body temperature. Food intake, total energy expenditure, and locomotor activity were not altered in knockout mice. Hadh(−/−) mice exhibited normal fat tolerance at 20 C. However, during cold exposure, knockout mice were unable to clear triglycerides from the plasma and to maintain their normal body temperature, indicating that SCHAD plays an important role in adaptive thermogenesis. Blood glucose concentrations in the fasted and postprandial state were significantly lower in hadh(−/−) mice, whereas insulin levels were elevated. Accordingly, insulin secretion in response to glucose and glucose plus palmitate was elevated in isolated islets of knockout mice. Therefore, our data indicate that SCHAD is involved in thermogenesis, in the maintenance of body weight, and in the regulation of nutrient-stimulated insulin secretion

    A Monte Carlo Study of Correlations in Quantum Spin Ladders

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    We study antiferromagnetic spin--1/2 Heisenberg ladders, comprised of ncn_c chains (2≤nc≤62 \leq n_c \leq 6) with ratio J⊥/J∥J_{\bot}/J_{\|} of inter-- to intra--chain couplings. From measurements of the correlation function we deduce the correlation length ξ(T)\xi(T). For even ncn_c, the static structure factor exhibits a peak at a temperature below the corresponding spin gap. Results for isotropically coupled ladders (J⊥/J∥=1J_{\bot}/J_{\|} = 1) are compared to those for the single chain and the square lattice. For J⊥/J∥≤0.5J_{\bot}/J_{\|} \leq 0.5, the correlation function of the two--chain ladder is in excellent agreement with analytic results from conformal field theory, and ξ(T)\xi(T) exhibits simple scaling behavior.Comment: 4 pages, 5 EPS figures, submitted to Phys. Rev. Let

    Dynamical spin correlations in Heisenberg ladder under magnetic field and correlation functions in SO(5) ladder

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    The zero-temperature dynamical spin-spin correlation functions are calculated for the spin-1/2 two-leg Heisenberg ladder in a magnetic field above the lower critical field Hc1. The dynamical structure factors are calculated which exhibit both massless and massive excitations. These modes appear in different sectors characterized by the parity in the rung direction and by the momentum in the direction of the chains. The structure factors have power-law singularities at the lower edges of their support. The results are also applicable to spin-1 Heisenberg chain. The implications are briefly discussed for various correlation functions and the pi-resonance in the SO(5) symmetric ladder model.Comment: 15 pages, 6 figures, added references; final version to appear in Phys. Rev.

    Coplanar ternary decay of hyper-deformed 56^{56}Ni

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    Ternary fission events from the decay of 56^{56}Ni compound nuclei, formed in the 32^{32}S + 24^{24}Mg reaction at Elab(32S)E_{lab}(^{32}S) = 163.5 MeV, have been measured in a unique set-up consisting of two large area position sensitive (x,y) gas detector telescopes. Very narrow out-of-plane correlations are observed for two fragments emitted in either purely binary events or in events with a missing mass consisting of 2 and 3 α\alpha-particles. These correlations are interpreted as ternary fission decay from compound nuclei at high angular momenta through an elongated (hyper-deformed) shape with very large moments of inertia, where the lighter mass in the neck region remains at rest

    Coplanar Ternary Cluster Decay of Hyper-deformed 56^{56}Ni

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    Coincidences between two heavy fragments have been measured from fission of 56Ni compound nuclei, formed in the 32S + 24Mg reaction at Elab(32S) = 163.5 MeV. A unique experimental set-up consisting of two large area position sensitive (x, y) gas-detector telescopes has been used allowing the complete determination of the observed fragments, and their momentum vectors. In addition to binary fission events with subsequent particle evaporation, narrow out-of-plane correlations are observed for two fragments emitted in purely binary events and in events with a missing mass consisting of 2α\alpha and 3α\alpha particles(12C). These events are interpreted as ternary cluster decay from 56Ni-nuclei at high angular momenta through hyper-deformed shape
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