50 research outputs found

    Quantitative analysis of suture lines in Carboniferous ammonoids

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    Two morphometric methods are applied and compared for the analysis of suture lines in Early Carboniferous ammonoids of the superfamilies Pericycloidea, Girtyoceratoidea and Goniatitoidea. We analysed (1) classic metric data (proportions of the width and depths or heights of lobes and saddles) using multivariate statistic methods and (2) outline data of the external lobe and the ventrolateral saddle of the same ammonoid taxa using the elliptic Fourier analysis. Both methods lead to similar results and simultaneously demonstrate ontogenetic and phylogenetic trends of these ammonoids. Our results are consistent with three previously suggested evolutionary patterns: (1) a general decrease of the amplitude of lobes and saddles, (2) a proportional widening of the external lobe and (3) a heightening of the median saddle.</p

    4f-spin dynamics in La(2-x-y)Sr(x)Nd(y)CuO(4)

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    We have performed inelastic magnetic neutron scattering experiments on La(2-x-y)Sr(x)Nd(y)CuO(4) in order to study the Nd 4f-spin dynamics at low energies. In all samples we find at high temperatures a quasielastic line (Lorentzian) with a line width which decreases on lowering the temperature. The temperature dependence of the quasielastic line width Gamma/2(T) can be explained with an Orbach-process, i.e. a relaxation via the coupling between crystal field excitations and phonons. At low temperatures the Nd-4f magnetic response S(Q,omega) correlates with the electronic properties of the CuO(2)-layers. In the insulator La(2-y)Nd(y)CuO(4) the quasielastic line vanishes below 80 K and an inelastic excitation occurs. This directly indicates the splitting of the Nd3+ ground state Kramers doublet due to the static antiferromagnetic order of the Cu moments. In La(1.7-x)Sr(x)Nd(0.3)CuO(4) with x = 0.12, 0.15 and La(1.4-x)Sr(x)Nd(0.6)CuO(4) with x = 0.1, 0.12, 0.15, 0.18 superconductivity is strongly suppressed. In these compounds we observe a temperature independent broad quasielastic line of Gaussian shape below T about 30 K. This suggests a distribution of various internal fields on different Nd sites and is interpreted in the frame of the stripe model. In La(1.8-y)Sr(0.2)Nd(y)CuO(4) (y = 0.3, 0.6) such a quasielastic broadening is not observed even at lowest temperature.Comment: 8 pages, 10 figures included, to appear in Phys. Rev.

    Impatto del moisture buffering sul clima interno di uffici ventilati meccanicamente

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    The aim of this work is to demonstrate the reliability of measured hygroscopic properties of materials in predicting the RH variation inside a room taking into account the material’s buffering effect. An analysis of reliability of the measured hygroscopic properties and their influence on numerical simulation is carried out. The influence of an important room factor as ventilation on the moisture buffer is taken into account for different scenarios

    Impact of moisture buffering on indoor climate for mechanically ventilated offices.

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    The aim of this work is to demonstrate the reliability of a simplified model in predicting the RH variation inside a room, taking into account the indoor material buffering effect. Starting from the characterization of the main hygroscopic properties of wood fiber an analysis of reliability of measured data for vapour permeability and sorption isotherm and their influence on numerical simulation is carried out. The determination of measured Moisture Buffer Value for the wood fiber is carried out through the simulation of the MBV test for uncoated elements. The results are compared to those from literature. The ventilation influence as room factor is taken into account for the whole room hygroscopic performance. More scenarios for different mechanical ventilation rates are foreseen considering a demand controlled and a fixed volume airflow. Simulations are carried out considering Turin weather data

    Scanning `Star Trek: The Next Generation'

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    SIGLEAvailable from British Library Document Supply Centre- DSC:95/34006 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

    Spinal inhibitory synaptic transmission in the glycine receptor mouse mutant spastic

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    Inhibitory glycine receptor (GlyR) and GABA(A) receptor (GABA(A)R)-mediated synaptic transmission was examined in two strains of the GlyR mutant mouse spastic and the respective wild types. The mutants display a mild and a severe neurological phenotype. Electrically evoked postsynaptic whole-cell currents were recorded from alpha-motoneurons in lumbar spinal cord slices. Amplitudes of GlyR-mediated IPSCs were significantly reduced in the severe phenotype in comparison to the respective wild type and the mild phenotype mutants. Surprisingly, amplitudes of GABA(A)R-mediated IPSCs were also significantly reduced in both mutants. Fast time constants of the decay phase of IPSCs were slightly reduced for the GlyR-mediated IPSCs and significantly larger for the GABA(A)R-mediated IPSCs in both mutant strains

    Delta III reverse shoulder arthroplasty in the treatment of complex 3- and 4-part fractures of the proximal humerus: 6 to 42 months of follow up

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    Background: There is a growing tendency for complex proximal humerus fractures (PHF) in osteoporotic patients to be treated with reverse shoulder arthroplasty (RSA). It has been proposed that RSA has more benefits than other treatment options. The aim of our study was to investigate preoperative characteristics as well as clinical and radiological outcomes in patients with complex 3- or 4-part PHF who had undergone primary RSA. Methods. Patients with a minimum follow-up of 6 months who had undergone a primary RSA after 3- or 4-part PHF in the period between 2008 and 2011 were eligible for the study. Clinical records, X-rays and CT-scans were investigated and a clinical examination was performed. Disabilities of the Arm, Shoulder and Hand (DASH) score and Constant-Murley score (CMS) were calculated. Sixteen patients were examined as part of the study. The mean follow-up was 20 months (range 6-42 months). According to Codman-Hertel classification we encountered 15 Hertel "12" and 1 Hertel "8" type fractures. Results: Thirty-two patients (27 female - 84.4%) with a mean age of 72 years underwent operations to treat complex 3- and 4-part fractures of the proximal humerus. Sixteen patients were reexamined. In 14 cases the dominant upper extremity was on the right, in 2 cases it was on the left, in 6 cases the right side was affected and in 10 cases the left side was affected. The mean CMS was 54.8 (range 18-95) and the mean DASH was 37.5 (range 2.9-81). A trend was established between the CMS and dominance of the affected shoulder. The CMS was better if the affected shoulder was on the non-dominant side (p-value 0.051). No statistical difference was noted between age and clinical outcome. Conclusions: Our mid-term follow-up shows satisfying results in terms of the treatment of severe displaced fractures in elderly patients with RSA. RSA can provide immediate relief and good shoulder function in elderly patients. Nevertheless, the question of longevity of these implants remains to be observed. © 2013 Mattiassich et al.; licensee BioMed Central Ltd
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