Analysis of ultrasonic transducers with fractal architecture

Ultrasonic transducers composed of a periodic piezoelectric composite are generally accepted as the design of choice in many applications. Their architecture is normally very regular and this is due to manufacturing constraints rather than performance optimisation. Many of these manufacturing restrictions no longer hold due to new production methods such as computer controlled, laser cutting, and so there is now freedom to investigate new types of geometry. In this paper, the plane wave expansion model is utilised to investigate the behaviour of a transducer with a self-similar architecture. The Cantor set is utilised to design a 2-2 conguration, and a 1-3 conguration is investigated with a Sierpinski Carpet geometry

Introducing a New Grade 8 Curriculum in Children's Rights

Existing research indicates that the effective implementation of new curricula depends on several variables including teachers' agreement with the goals of a new program, its impact on workload, and opportunities for professional development. The purpose of this research was to assess how far 31 grade 8 teachers implemented a new children s rights curriculum, whether the implementation of the curriculum changed their and their students' attitudes about children's rights, and to identify factors that encouraged implementation. Major findings were as follows: Workload, defined in terms of years of experience and class size, was predictive of curriculum use. The more teachers used the curriculum, the higher they rated it and the more they expressed attitudes supportive of children's rights. Students' support for the rights of adults, including ethnocultural minorities and those with disabilities, was positively related to their teachers' support for children's rights.La recherche indique que la mise en œuvre réussie d'un nouveau curriculum dépend de plusieurs variables dont l'accord de renseignant quant aux buts du nouveau programme, son impact sur la charge de travail et les occasions de développement professionnel que l'on présente. Cette recherche avait trois buts : évaluer dans quelle mesure 31 enseignants de la 8e année ont mis en application un nouveau curriculum sur les droits des enfants, déterminer si la mise en vigueur a changé l'attitude des enseignants et des élèves face aux droits des enfants, et identifier les facteurs qui facilitent la mise en application. Les résultats indiquent que la charge de travail, définie en fonction des années d'expérience et de la taille de la classe, constituait une valeur prédictive quant à l'emploi que ferait un enseignant du nouveau curriculum. Plus les enseignants utilisaient le curriculum, plus ils l'appréciaient et plus leur attitude face aux droits des enfants était positive. Une corrélation positive a également été établie entre l'appui que manifestaient les élèves face aux droits des adultes, y compris ceux des minorités ethnoculturelles et des personnes ayant une déficience, et l'appui des enseignants pour les droits des enfants

Nuclear alpha-clustering, superdeformation, and molecular resonances

Nuclear alpha-clustering has been the subject of intense study since the advent of heavy-ion accelerators. Looking back for more than 40 years we are able today to see the connection between quasimolecular resonances in heavy-ion collisions and extremely deformed states in light nuclei. For example superdeformed bands have been recently discovered in light N=Z nuclei such as $^{36}$Ar, $^{40}$Ca, $^{48}$Cr, and $^{56}$Ni by $\gamma$-ray spectroscopy. The search for strongly deformed shapes in N=Z nuclei is also the domain of charged-particle spectroscopy, and our experimental group at IReS Strasbourg has studied a number of these nuclei with the charged particle multidetector array {\sc Icare} at the {\sc Vivitron} Tandem facility in a systematical manner. Recently the search for $\gamma$-decays in $^{24}$Mg has been undertaken in a range of excitation energies where previously nuclear molecular resonances were found in $^{12}$C+$^{12}$C collisions. The breakup reaction $^{24}$Mg$+^{12}$C has been investigated at E$_{lab}$($^{24}$Mg) = 130 MeV, an energy which corresponds to the appropriate excitation energy in $^{24}$Mg for which the $^{12}$C+$^{12}$C resonance could be related to the breakup resonance. Very exclusive data were collected with the Binary Reaction Spectrometer in coincidence with {\sc Euroball IV} installed at the {\sc Vivitron}.Comment: 10 pages, 4 eps figures included. Invited Talk 10th Nuclear Physics Workshop Marie and Pierre Curie, Kazimierz Dolny Poland, Sep. 24-28, 2003; To be published in International Journal of Modern Physics

Longitudinal stability of genetic and environmental influences on the association between diurnal preference and sleep quality in young adult twins and siblings

Overlapping genetic influences have been implicated in diurnal preference and subjective sleep quality. Our overall aim was to examine overlapping concurrent and longitudinal genetic and environmental effects on diurnal preference and sleep quality over ~5 years. Behavioural genetic analyses were performed on data from the longitudinal British G1219 study of young adult twins and non-twin siblings. 1556 twins and siblings provided data on diurnal preference (Morningness-Eveningness Questionnaire) and sleep quality (Pittsburgh Sleep Quality Index) at time 1 (mean age=20.30 years, SD=1.76; 62% female); and 862 participated at time 2 (mean age=25.30 years, SD=1.81; 66% female). Preference for eveningness was associated with poorer sleep quality at both time-points (r=.25[95% confidence intervals, (CI)=.20-.30], and r=.21[CI=.15-.28]). There was substantial overlap in the genetic influences on diurnal preference and sleep quality individually, across time (genetic correlations [rA’s]: .64[95% CI = .59-.67] and .48[95% CI = .42-.53]). There were moderate genetic correlations between diurnal preference and sleep quality concurrently and longitudinally (rAs=.29-.60). Non-shared environmental overlap was substantially smaller for all cross-phenotype associations (non-shared environmental correlations [rE’s]=-.02-.08). All concurrent and longitudinal associations within and between phenotypes were largely accounted for by genetic factors (explaining between 60%-100% of the associations). All shared environmental effects were non-significant. Non-shared environmental influences played a smaller role on the associations between phenotypes (explaining between -.06%-40% of the associations). These results suggest that to some extent similar genes contribute to the stability of diurnal preference and sleep quality throughout young adulthood, but also that different genes play a part over this relatively short time-frame. While there was evidence of genetic overlap between phenotypes concurrently and longitudinally, the possible emergence of new genetic factors (or decline of previously associated factors) suggests that molecular genetic studies focussing on young adults should consider more tightly specified age-groups, given that genetic effects may be time-specific

La exploración de las categorizaciones de la tipología de los varones violentos en la pareja: un estudio metodológico

Intimate partner violence (IPV) perpetrators were categorized based on whether they were generally violent (GV) or family only violent (FO) using self-report or arrest records. Classification criteria to assess recidivism in perpetrators of IPV were evaluated herein to determine the incremental validity of using a perpetrator’s criminal history in addition to their self-report information for categorization purposes. The concordance rates for categorizing subtypes of male perpetrators were compared for two methods, namely, self-report versus criminal history data. Categorizations were made based on self-reported history of violence and federal criminal records separately. Between measures consistency was defined as whether or not the self-report categorizations matched federal criminal record categorizations. It was hypothesized that self-report would not be sufficient as the sole method of categorizing male perpetrators, and the use of criminal history data would add to the validity of the categorization system. Self-reports of aggression were higher than criminal records of aggression. Using data sources together may yield the best outcomes for offenders and society. Implications are discussed.Se clasificaron los varones que ejercen violencia en las relaciones de pareja (VP) en función de si eran violentos en general (VG) o solo en el entorno familiar (VF), empleando registros de autoinformes o de arrestos. Se analizaron los criterios de clasificación para evaluar la reincidencia de los infractores de VP con el fin de determinar la validez incremental del uso de los antecedentes penales del infractor, además de la información procedente de su autoinforme para la clasificación. Se compararon los índices de concordancia para categorizar los subtipos de infractores masculinos para dos métodos: los datos procedentes de autoinforme y los de antecedentes penales. La categorización se basó en la historia de violencia autoinformada y en los antecedentes penales por separado. La congruencia entre medidas se definió como la coincidencia o discrepancia de la categorización de autoinforme con la categorización de antecedentes penales. Se planteó la hipótesis de que el autoinforme no bastaba como único método para clasificar a los infractores masculinos y que el uso de datos procedentes de antecedentes penales aumentaba la validez del sistema de categorización. Hubo más autoinformes sobre agresión que antecedentes penales de agresión. El uso conjunto de ambos podría tener mejores resultados, tanto para los delincuentes como para la sociedad. Se discuten las implicaciones de estos resultados.S

Bayesian Classification and Regression Trees for Predicting Incidence of Cryptosporidiosis

Background Classification and regression tree (CART) models are tree-based exploratory data analysis methods which have been shown to be very useful in identifying and estimating complex hierarchical relationships in ecological and medical contexts. In this paper, a Bayesian CART model is described and applied to the problem of modelling the cryptosporidiosis infection in Queensland, Australia. Methodology/Principal Findings We compared the results of a Bayesian CART model with those obtained using a Bayesian spatial conditional autoregressive (CAR) model. Overall, the analyses indicated that the nature and magnitude of the effect estimates were similar for the two methods in this study, but the CART model more easily accommodated higher order interaction effects. Conclusions/Significance A Bayesian CART model for identification and estimation of the spatial distribution of disease risk is useful in monitoring and assessment of infectious diseases prevention and control

Tart Cherry Concentrate Does Not Alter the Gut Microbiome, Glycaemic Control or Systemic Inflammation in a Middle-Aged Population.

This is the final version. available from MDPI via the DOI in this recordLimited evidence suggests that the consumption of polyphenols may improve glycaemic control and insulin sensitivity. The gut microbiome produces phenolic metabolites and increases their bioavailability. A handful of studies have suggested that polyphenol consumption alters gut microbiome composition. There are no data available investigating such effects in polyphenol-rich Montmorency cherry (MC) supplementation. A total of 28 participants (aged 40-60 years) were randomized to receive daily MC or glucose and energy-matched placebo supplementation for 4 wk. Faecal and blood samples were obtained at baseline and at 4 wk. There was no clear effect of supplementation on glucose handling (Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) and Gutt indices), although the Matsuda index decreased significantly in the MC group post-supplementation, reflecting an increase in serum insulin concentration. Contrastingly, placebo, but not MC supplementation induced a 6% increase in the Oral Glucose Insulin Sensitivity (OGIS) estimate of glucose clearance. Serum IL-6 and C reactive protein were unaltered by either supplement. The faecal bacterial microbiome was sequenced; species richness and diversity were unchanged by MC or placebo and no significant correlation existed between changes in Bacteroides and Faecalibacterium abundance and any index of insulin sensitivity. Therefore, 4 weeks of MC supplementation did not alter the gut microbiome, glycaemic control or systemic concentrations of IL-6 and CRP in a middle-aged population.The Cherry Marketing Institut

The Race Between Stars and Quasars in Reionizing Cosmic Hydrogen

The cosmological background of ionizing radiation has been dominated by quasars once the Universe aged by ~2 billion years. At earlier times (redshifts z>3), the observed abundance of bright quasars declined sharply, implying that cosmic hydrogen was reionized by stars instead. Here, we explain the physical origin of the transition between the dominance of stars and quasars as a generic feature of structure formation in the concordance LCDM cosmology. At early times, the fraction of baryons in galaxies grows faster than the maximum (Eddington-limited) growth rate possible for quasars. As a result, quasars were not able to catch up with the rapid early growth of stellar mass in their host galaxies.Comment: 5 pages, 1 figure, Accepted for publication in JCA