X-Ray Quantitative Evaluation of Multi-Layered Objects from Few Projections: A Multiresolution Technique

In this paper, we present the results of a study[1] motivated by the radiographic inspection of solder joints on double-sided printed circuits. Our goal was to obtain quantitative information about the structures in these planar objects, taking into account the acquisition geometry and time constraints. On one hand, we must limit the acquisition angle for projections at a value of ± 50 degrees with respect to the normal to the object plane, in order to limit the attenuation of the material crossed by X-rays. On the other hand, we must limit the number of projections in order to reduce as far as possible the acquisition and processing times

The Alperin Weight Conjecture and the Glauberman correspondence via character triples

Recently, G. Navarro introduced a new conjecture that unifies the Alperin Weight Conjecture and the Glauberman correspondence into a single statement. In this paper, we reduce this problem to simple groups and prove it for several classes of groups and blocks. Our reduction can be divided into two steps. First, we show that assuming the so-called Inductive (Blockwise) Alperin Weight Condition for finite simple groups, we obtain an analogous statement for arbitrary finite groups, that is, an automorphism-equivariant version of the Alperin Weight Conjecture inducing isomorphisms of modular character triples. Then, we show that the latter implies Navarro's conjecture for each finite group

Compact cryogenic Kerr microscope for time-resolved studies of electron spin transport in microstructures

A compact cryogenic Kerr microscope for operation in the small volume of high-field magnets is described. It is suited for measurements both in Voigt and Faraday configuration. Coupled with a pulsed laser source, the microscope is used to measure the time-resolved Kerr rotation response of semiconductor microstructures with ~1 micron spatial resolution. The microscope was designed to study spin transport, a critical issue in the field of spintronics. It is thus possible to generate spin polarization at a given location on a microstructure and probe it at a different location. The operation of the microscope is demonstrated by time-resolved measurements of micrometer distance diffusion of spin polarized electrons in a GaAs/AlGaAs heterojunction quantum well at 4.2 K and 7 Tesla

Temperature-Staged Thermal Energy Storage Enabling Low Thermal Exergy Loss Reflux Boiling in Full Spectrum Solar Energy Systems

The efficiency of solar power collection is increased by adding a thermal energy storage stage to a sunlight concentrator and thermodynamic power generator system. The thermal energy storage includes tubes or capsules made of a phase change material that stores thermal energy in different temperature stages through a working fluid. The stored thermal energy is directed to the thermodynamic generator during off-sun periods

Suppressed spin dephasing for 2D and bulk electrons in GaAs wires due to engineered cancellation of spin-orbit interaction terms

We report a study of suppressed spin dephasing for quasi-one-dimensional electron ensembles in wires etched into a GaAs/AlGaAs heterojunction system. Time-resolved Kerr-rotation measurements show a suppression that is most pronounced for wires along the [110] crystal direction. This is the fingerprint of a suppression that is enhanced due to a strong anisotropy in spin-orbit fields that can occur when the Rashba and Dresselhaus contributions are engineered to cancel each other. A surprising observation is that this mechanisms for suppressing spin dephasing is not only effective for electrons in the heterojunction quantum well, but also for electrons in a deeper bulk layer.Comment: 5 pages, 3 figure

The N-terminal domains of syntaxin 7 and vti1b form three-helix bundles that differ in their ability to regulate SNARE complex assembly

The SNAREs syntaxin 7, syntaxin 8, vti1b, and endobrevin/VAMP8 function in the fusion of late endosomes. Although the core complex formed by these SNAREs is very similar to the neuronal SNARE complex, it differs from the neuronal complex in that three of the four SNAREs contain extended N-terminal regions of unknown structure and function. Here we show that the N- terminal regions of syntaxin 7, syntaxin 8, and vti1b contain well folded a-helical domains. Multidimensional NAIR spectroscopy revealed that in syntaxin 7 and vti1b, the domains form three-helix bundles resembling those of syntaxin 1, Sso1p, and Vam3p. The three-helix bundle domain of vti1b is the first of its kind identified in a SNARE outside the syntaxin family. Only syntaxin 7 adopts a closed conformation, whereas in vti1b and syntaxin 8, the N-terminal domains do not interact with the adjacent SNARE motifs. Accordingly, the rate of SNARE complex assembly is retarded about 7-fold when syntaxin 7 contains its N-terminal domain, whereas the N-terminal domains of vti1b and syntaxin 8 have no influence on assembly kinetics. We conclude that three-helix bundles represent a common fold for SNARE N- terminal domains, not restricted to the syntaxin family. However, they differ in their ability to adopt closed conformations and thus to regulate the assembly of SNARE complexes

Metodología para la evaluación de la sostenibilidad en autopistas: cálculo del balance energético de la infraestructura.

El trabajo aborda el desarrollo de un procedimiento para la evaluación de la eficiencia energética en infraestructuras lineales desde el punto de vista constructivo. El procedimiento permite calcular, tanto globalmente como de forma independizada, el balance energético de las diferentes fases del ciclo de vida de la infraestructura: construcción, operación y desmantelamiento o deconstrucción

Growth Trait Heredity in Two Cavy Sublines Native to the Ecuadoran Mountain Range

Background: No studies have been published on South American cavy preservation and breeding programs; therefore, the aim of this article was to analyze the genotypic and environmental factors that act upon the growth traits of a South American native cavy line found in the Ecuadoran Mountain Range. Methods: The study took place on Irquis experimental farm, from the Faculty of Agricultural Sciences, University of Cuenca, using two native cavy sublines from rural breeders in provinces Azuay and Cañar. Weight per age and daily weight gain (g) were analyzed by a mixed variance analysis of litter size (5), season (semester), sex, and parturition number of the mother as fixed effects, using software R 3.4.4. The random effects were made by sub-lines Azuay (1) and Cañar (2), and their male parents. The basic statistical values were determined. Results: Birth weight, weaning weight, and weight at 90 days in grams, were 110.2 ± 1.81, 117.0 ± 1.44; 212.2 ± 4.30 and 221.13 ± 3.38; 540.7 ± 12.01, and 659.1 ± 9.44, respectively. The heredity values for these traits were 0.09 ± 0.101, 0.34 ± 0.201, and 0.11 ± 0.111. Besides, weight was analyzed at 30, 45, 60, 75, and 90 days after birth, which included gains at every age. The BLUP predictors for the parents of the two sub-lines were determined. Variation and heritability allowed for selection of weight at weaning and at 90 days. Conclusions: This line showed low growth levels, though the variations observed were adequate. Their heredity might lead to the expected favorable results, provided a selection program is implemented in the mid-term.Background: No studies have been published on South American cavy preservation and breeding programs; therefore, the aim of this article was to analyze the genotypic and environmental factors that act upon the growth traits of a South American native cavy line found in the Ecuadoran Mountain Range. Methods: The study took place on Irquis experimental farm, from the Faculty of Agricultural Sciences, University of Cuenca, using two native cavy sublines from rural breeders in provinces Azuay and Cañar. Weight per age and daily weight gain (g) were analyzed by a mixed variance analysis of litter size (5), season (semester), sex, and parturition number of the mother as fixed effects, using software R 3.4.4. The random effects were made by sub-lines Azuay (1) and Cañar (2), and their male parents. The basic statistical values were determined. Results: Birth weight, weaning weight, and weight at 90 days in grams, were 110.2 ± 1.81, 117.0 ± 1.44; 212.2 ± 4.30 and 221.13 ± 3.38; 540.7 ± 12.01, and 659.1 ± 9.44, respectively. The heredity values for these traits were 0.09 ± 0.101, 0.34 ± 0.201, and 0.11 ± 0.111. Besides, weight was analyzed at 30, 45, 60, 75, and 90 days after birth, which included gains at every age. The BLUP predictors for the parents of the two sub-lines were determined. Variation and heritability allowed for selection of weight at weaning and at 90 days. Conclusions: This line showed low growth levels, though the variations observed were adequate. Their heredity might lead to the expected favorable results, provided a selection program is implemented in the mid-term

A systematic review of conceptualizations and operationalizations of youth polyvictimization

Violence against youth is a global issue impacting millions each year. Increasingly, research has focused on studying those impacted by multiple forms of violence, or polyvictims. Evidence strongly suggests that polyvictimized youth tend to have worse physical and mental health outcomes than those who have experienced single forms of violence. Moreover, minoritized youth (i.e., racial and/or sexual minority youth, youth with disabilities) are more likely to experience polyvictimization, making this a social justice and equity concern. To date, there is no universal consensus on what exactly constitutes polyvictimization. This systematic review aims to examine the ways in which polyvictimization is being studied to inform both research and practice. As such, relevant databases were searched to amass the extant literature related to youth polyvictimization internationally. Empirical studies published since 2006 that focused on youth (under age 18) polyvictimization were included. After the review process, 264 studies met eligibility criteria, however 55 studies employed person-centered/finite mixture analyses and were removed for a separate review, resulting in 209 featured in the current systematic review. Results demonstrate that researchers are defining and operationalizing polyvictimization in different ways: (a) using individual victimization event counts; (b) employing domain-based counts; and (c) taking a “highest-victimized” percentage of their sample. The most used measurement tool was the Juvenile Victimization Questionnaire, though other validated tools and researcher-constructed questions were frequently utilized. Research on polyvictimization is burgeoning worldwide; however, this research is being conducted in disparate ways, making it difficult to compare findings and further advance the field.</p