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Censoring distances based on labeled cortical distance maps in cortical morphometry
No full textIt has been demonstrated that shape differences in cortical structures may be manifested in neuropsychiatric disorders. Such morphometric differences can be measured by labeled cortical distance mapping (LCDM) which characterizes the morphometry of the laminar cortical mantle of cortical structures. LCDM data consist of signed/labeled distances of gray matter (GM) voxels with respect to GM/white matter (VW) surface. Volumes and other summary measures for each subject and the pooled distances can help determine the morphometric differences between diagnostic groups, however they do not reveal all the morphometric information contained in LCDM distances. To extract more information from LCDM data, censoring of the pooled distances is introduced for each diagnostic group where the range of LCDM distances is partitioned at a fixed increment size; and at each censoring step, the distances not exceeding the censoring distance are kept. Censored LCDM distances inherit the advantages of the pooled distances but also provide information about the location of morphometric differences which cannot be obtained from the pooled distances. However, at each step, the censored distances aggregate, which might confound the results. The influence of data aggregation is investigated with an extensive Monte Carlo simulation analysis and it is demonstrated that this influence is negligible. As an illustrative example, GM of ventral medial prefrontal cortices (VMPFCs) of subjects with major depressive disorder (MDD), subjects at high risk (HR) of MDD, and healthy control (Ctrl) subjects are used. A significant reduction in laminar thickness of the VMPFC in MDD and HR subjects is observed compared to Ctrl subjects. Moreover, the GM LCDM distances (i.e., locations with respect to the GM/WM surface) for which these differences start to occur are determined. The methodology is also applicable to LCDM-based morphometric measures of other cortical structures affected by disease
Low vitamin D status associated with dilated cardiomyopathy
No full textIn recent years, a growing body of evidence supports that vitamin D plays a crucial role in various cardiovascular diseases. Cardiac muscle cells have vitamin D receptors as well as calcitriol-dependent Ca2+ binding protein. Therefore, the vitamin D may have an effect on cardiac function. In this research, we investigated the association between vitamin D status and dilated cardiomyopathy (DCMP). We compared serum 25-hydroxy-vitamin D3 (25OHD3) concentrations in 39 patients (mean age 50.4 +/- 11.7 years, 15 women) with DCMP and in 35 healthy controls (mean age 54.6 +/- 13.2 years, 17 women). Parathyroid hormone (PTH), calcium (Ca++), phosphorus, lipid profile, albumin and echocardiographic parameters (left-ventricular (LV) ejection fraction, LV fractional shortening, LV-end-diastolic and end-systolic dimensions) were measured in all study participants. The mean serum 25OHD3 concentrations in patients with the DCMP were significantly lower in compared to healthy controls (24.1 +/- 10.4 ng/mL versus 41.4 +/- 20.9 ng/mL, P < 0.0001). PTH concentrations were significantly higher in patients with DCMP in comparison with healthy controls (90.6 +/- 29.8 pg/mL versus 49.1 +/- 18 pg/mL, P < 0.0001). Additionally, we observed a significant negative correlation between 25OHD3 concentrations and PTH concentrations, LV end-diastolic dimensions, LV end-systolic dimensions (r = -0.66; P < 0.0001, r = -0.49; P < 0.0001, r = -0.50; P < 0.0001, respectively). Moreover, 25OHD3 was positively correlated with LV ejection fraction, LV fractional shortening, stroke volume, cardiac output, cardiac index (r = 0.46; P < 0.001, r = 0.44; P < 0.001, r = 0.25; P = 0.03, r = 0.37; P < 0.001, r = 0.25; P = 0.03; respectively). Our findings support that vitamin D has a potential role both in the development of DCMP and LV remodeling
A place of burning: hero or ancestor cult at troy
No full textThis article presents the evidence for Early Archaic ritual activity on the site of a Late Bronze Age cemetery a short distance outside the walls of Troy, at a spot known to excavators as "A Place of Burning." Here, as at the West Sanctuary adjacent to the citadel, the evidence follows a pattern similar to that found in hero and ancestor cults at other sites. Growing population in the region may have led the inhabitants of Troy to use associations with Bronze Age remains as a way of strengthening territorial claims and bolstering the power of the local elite
Offline force control and feedrate scheduling for complex free form surfaces in 5-Axis milling
No full textAn enhanced Force model based Feedrate Scheduling (FFS) technique for rough cutting of parts with complex free form surfaces in 5-axis machining is presented. In order to estimate the cutting forces in complex 5-axis machining an enhanced solid modeler kernel based model is developed to find the complicated engagement between cutter and workpiece for each cutter location. In this paper, cutter-workpiece engagement model is presented using the commercial Parasolid solid modeler kernel, and then cutting forces are estimated based on the developed model. In this approach, the resultant cutting forces are kept constant on a user defined threshold. The feedrate will be adjusted to keep the resultant cutting forces constant all along the tool path. Therefore, it is shown that this approach allows decreasing the cycling time drastically. The scheduled feedrate in each cutter location is carried out in NC blocks using an off-line postprocessor that can be used in commercial CAM software. Eventually, the proposed FFS technique is experimentally tested on rough machining of an impeller with free form surfaces and force validations are presented in this article
Synthesis and characterization of mesoporous zirconium oxide thin films
No full textZirconium oxide (ZrO2) has generated wide interest because of its potential in applications such as solid oxide fuel cells, catalysts and optical devices. In these applications, it is important to control the grain size of the material and increase the surface area by introducing porosity with tailored pore size. This paper presents a synthesis route for the preparation of mesoporous zirconia using spin-coating method combined with block copolymer templating evaporation induced self assembly (EISA). The hybrid mesophase was formed by zirconium oxychloride precursor ZrOCl2 center dot 8H(2)O and Brij 700 poly-ethylene oxide based block copolymer template C18H37(OCH2CH2). FT-IR and Raman measurements of the hybrid mesophase provided information on the possible intermolecular interactions between the precursor and the copolymer template. The results indicate a weak ion-dipole interaction between the inorganic precursor and the organic template after the solvent evaporation, possibly directly between the zirconium and the oxygen of the poly-ethylene oxide chain. The removal of the organic block copolymer by heat treatment resulted in mesoporous zirconia with pore size of similar to 4-8 nm and crystalline grain size of similar to 10-17 nm. The morphology in thin films depended significantly on the solvent quality and the block copolymer concentration. Tailoring the surface morphology and the grain size resulted in super-hydrophilic mesoporous zirconia thin films in contrast to water contact angle of 50 degrees on conventional tetragonal zirconium oxide
Silicon photonics with microspheres
No full textSilicon microspheres coupled to optical fibers have been used for optical channel dropping in the near-IR. The observed morphology dependent resonances had quality factors of 100000. These optical resonances provide the necessary narrow linewidths, that are needed for high resolution optical filtering applications in the near-IR. In addition to filtering, detection, and switching applications of this photonic system is studied in the near-IR as well as far-IR. The silicon microsphere shows promise as a building block for silicon photonics in the near-IR as well as, mid-IR, and far-IR
Bosonic helium droplets with cationic impurities: onset of electrostriction and snowball effects from quantum calculations
No full textVariational Monte Carlo and diffusion Monte Carlo calculations have been carried out for cations such as Li(+), Na(+), and K(+) as dopants of small helium clusters over a range of cluster sizes up to about 12 solvent atoms. The interaction has been modeled through a sum-of-potential picture that disregards higher order effects beyond atom-atom and atom-ion contributions. The latter were obtained from highly correlated ab initio calculations over a broad range of interatomic distances. This study focuses on two of the most striking features of the microsolvation in a quantum solvent of a cationic dopant: electrostriction and snowball effects. They are discussed here in detail and in relation with the nanoscopic properties of the interaction forces at play within a fully quantum picture of the cluster features
Finite difference modeling of coherent wave amplification in the Earth's radiation belts
No full textModeling of gyroresonant wave-particle interactions in the radiation belts requires solving the Vlasov-Maxwell system of equations in an inhomogenous background geomagnetic field. Previous works have employed particle-in-cell methods or Eulerian solvers (such as the Vlasov Hybrid Simulation code) to provide numerical solutions to the problem. In this report, we provide an alternative numerical approach by utilizing a first order finite difference upwind scheme. When coupled to the narrowband Maxwell's equations, the model reproduces linear as well as nonlinear wave growth of coherent signals. Wave growth is nonlinear growth when the wave amplitude exceeds the minimum value for phase trapping of counterstreaming particles and is linear otherwise. The model also demonstrates free-running frequency variation for a case with a high linear growth rate. In addition, the model confirms the theoretical prediction of a stable phase-space hole during the nonlinear growth process. The plasma parameters and L shell used in this study are typical of those associated with the Siple Station wave injection experiment
Macroscopic quantum tunnelling of magnetization in spinor Bose-Einstein condensates
No full textWe investigate macroscopic quantum tunneling of magnetization in a a spinor Bose- Einstein condensate trapped in a double-well potential. Using the mean field theory applicable for large condensates, and employing the single spatial mode approximation we derive dynamical equations for magnetization, independent from density mode, for certain initial conditions. We show that they can be reduced to standard Josephson junction dynamics equations under certain conditions
Changing life styles - changing competencies: Turkish migrant youth in Europe
No full text"Veranderte Lebensstile - Veranderte Kompetenzen: Turkische Migrationsjugendliche in Europa". This paper examines the plight of Turkish migrant youth in Europe particularly as migration involves social change in terms of changing life styles which require changing competencies. For the migrant youth to be assets, rather than problems, for the receiving society, their full integration into society should be ensured. This requires the enhancement of their cognitive competence and psycho-social development involving the autonomous-related self. Drawing parallels between rural to urban migration and international migration with regard to the experienced social change, the Turkish Early Enrichment Project (TEEP) is taken up as a case in point. TEEP showed that early childhood enrichment through supporting the mothers among rural to urban migrants in Istanbul, Turkey was beneficial for both the cognitive competence and the psycho-social development of their children. The gains were found to be sustained into young adulthood. Similar programs of intervention and support would be highly beneficial for ethnic migrants in Europe, particularly for Turkish-German youth, given the fact that they tend to do poorly in school. Immigrants' positive youth development, involving the enhancement of autonomous-related self, cognitive competence, psychological and socio-cultural adaptation, promises to provide far reaching benefits to the receiving societies, as well