Search results for "Extern"

Mutations of mitochondrial DNA and human death.

1990

In the skeletal muscle of patients with mitochondrial myopathies (Kearns-Sayre syndrome and chronic progressive external ophthalmoplegia) and in the heart and skeletal muscle of healthy persons cells lacking cytochrome c oxidase are found. The respiratory-defective cells have the following features in common: onset of the defect at juvenile or adult age; progressive character of the defect with increasing age; and focal pattern of respiratory-deficient cells (fibers). A statistic mutation of mtDNA in affected cells is suggested to cause the defect of mitochondrial function. It is postulated that the continuous accumulation of respiratory-deficient cells, mainly in the human heart with incre…

CBCT assessment of radicular volume loss after rapid maxillary expansion : a systematic review

2018

Background The present systematic review analyzed the current literature to investigate whether rapid maxillary expansion (RME) causes radicular resorption, assessed by cone-beam computed tomography (CBCT). Material and methods Eighteen electronic databases and reference lists of studies were searched up to November 2017. Grey literature was also screened. To be included, articles must be human studies on growing subjects with transversal maxillary deficiency treated with maxillary expansion protocol and with 3-D radiographic assessment of radicular volume by CBCT images. Two authors independently performed study selection, data extraction, and risk of bias assessment. Study characteristics…

Validation of the Five-Factor Self-Concept Questionnaire AF5 in Brazil: Testing factor structure and measurement invariance across language (Brazilia…

2018

Self-concept is widely conceptualized as multidimensional (Shavelson et al., 1976). The Five-Factor Self-Concept Questionnaire (AF5, Garcia and Musitu, 2009) assesses five specific dimensions (i.e., academic, social, emotional, family, and physical). It is a psychometrically sound questionnaire, developed, and normed in Spain, which is widely used with Spanish-speaking samples. The validation of the AF5 in Brazil would expand its potential, and would facilitate cross-cultural research. To validate the Brazilian version of the AF5, the present study apply confirmatory factor analysis and multi-sample invariance analysis across sex (women vs. men), age (11-18 years old), and language (Brazili…

Looking Across Instead of Back and Forth: How the Simultaneous Presentation of Multiple Animation Episodes Facilitates Learning

2017

Many learning tasks require students to induce higher-order relationships from the learning material. Compare and contrast processes play a pivotal role in solving such inductive tasks. Different presentations of animation episodes offer affordances to students that can either impede or facilitate compare and contrast processes. While conventional behaviorally realistic animations typically present multiple episodes one after the other, i.e. sequentially, simultaneous presentation offers a feasible alternative. We investigated how the sequential and simultaneous presentation of multiple animation episodes affects students’ perceptual interrogation of the animation as well as their learning …

Single cigar-shaped nanopores functionalized with amphoteric amino acid chains: experimental and theoretical characterization.

2012

We present an experimental and theoretical characterization of single cigar-shaped nanopores with pH-responsive carboxylic acid and lysine chains functionalized on the pore surface. The nanopore characterization includes (i) optical images of the nanostructure obtained by FESEM; (ii) different chemical procedures for the nanopore preparation (etching time and functionalizations; pH and electrolyte concentration of the external solution) allowing externally tunable nanopore responses monitored by the current-voltage (I-V) curves; and (iii) transport simulations obtained with a multilayer nanopore model. We show that a single, approximately symmetric nanopore can be operated as a reconfigurab…

Polarization Switching in Heterophase Nanostructures: PLZT Relaxor Ceramics

2005

The polarization switching is experimentally investigated in hot-pressed PLZT-x/65/35 ceramics with a lanthanum content from 5 to 12 at. %. The specific features in the temperature dependence of the polarization switching in a heterophase state are interpreted by analyzing the change in the switched charge measured over wide ranges of fields and temperatures. Particular emphasis is placed on the role of depolarization fields induced by interphase boundaries. A model of the evolution of polydomain nanostructures with a change in the temperature and in the response to an external field is considered. It is assumed that the low-temperature dielectric anomaly and the temperature hysteresis are …

Positive/negative symptomatology and experimental measures of attention in schizophrenic patients.

1993

In a search for an external validation of the negative syndrome construct and the attentional impairment item on Andreasen's scale, 49 unmedicated schizophrenic patients were administered the Span of Apprehension Test and a Continuous Performance Test with two levels of difficulty. This schizophrenic sample performed significantly more poorly on the attentional tests than a comparable group of 27 healthy control subjects. Depending on the difficulty of the test we found a number of significant correlations between the SANS composite score and the pertaining attentional impairment item on the one hand and experimental indices of attentional functioning on the other hand, which might corrobor…

Sur les Terminaisons Nerveuses Sensitives du Clitoris chez la Truie (Sus scrofa domesticus)

1991

Summary On the Sensory Nerve-Endings in the Porcine Clitoris Neural receptors of the porcine clitoris were examined using light and electron microscopy. Perfusion with ink allowed study of the unique vascular arrangement associated with the genital corpuscles. Sensory nerve-endings were generally rounded and formed a morphologically and structurally characteristic unit. They were composed of a network of primarily non-myelinated nerve fibers and flat cells. Between these structures, isolated small blood vessels were embedded amongst collagen fibers and amorphous material. An external capsule of variable thickness always surrounded the structures. A complex arrangement of vessels in the cent…

Nonlinear Analysis of Reinforced Concrete Frames: Safety Evaluation and Retrofitting Techniques

A new beamline for energy-dispersive high-resolution PIXE analysis using polycapillary optics

2019

Abstract A new beamline for high energy resolution PIXE measurements is presented. This new setup includes options for both in-air and vacuum measurements. For the high energy resolution transition-edge sensor array, a polycapillary lens is used for detecting low-energy X-rays down to 0.5 keV and to increase the effective solid angle. X-ray transmission of the polycapillary lens was characterized using two calibration standards. The gain obtained by adding a polycapillary lens was 1.6–2.3 at energies between 2.1 keV and 4.5 keV. From 1.04 to 1.74 keV the gain is increased to 2.1–3.0, and at energies 4.9–8.0 keV the gain is between 1.6 and 0.65. The measured gain agreed well with theoretical…