Edge strength of core drilled and waterjet cut holes in architectural glass

In structural glass design, an often-applied connection is a bolted connection subjected to in-plane tensile loads. Traditionally, the hole in the glass pane is manufactured by core drilling and conical edge finishing. An alternative method is by waterjet cutting the holes, resulting in cylindrically shaped holes. This research compares the edge strength of core drilled and waterjet cut holes. It focuses on in-plane tensile tests and consists of an experimental part in combination with a numerical part. In the in-plane tensile tests, peak stresses occur perpendicular to the load direction. These stresses are found to be higher for waterjet cut holes (+ 13%) compared to core drilled holes. As a result, the characteristic ultimate load is lower for waterjet cut holes (− 16%). Furthermore, the influence of thermally toughening the glass is found to be more favourable for the characteristic ultimate load of specimens containing core drilled holes than it is for waterjet cut holes. Next to that, it was found that the ultimate load linearly increases with the panel thickness. Eccentric loading, caused by insufficient bushing material or rotation of the bolt, only slightly decreases the ultimate load, provided that no hard contact between bolt and glass occurs. In addition, coaxial double ring tests were performed in the hole area, showing that waterjet cut holes result in larger stresses near the hole edge than core drilled holes. Furthermore, waterjet cut holes are found not to be perfectly round, while drilled holes are. This un-roundness negatively influences the ultimate load and the stresses in the glass; the larger the extent of un-roundness, the higher the stresses and the lower the ultimate load. Also, the orientation of the un-round hole is of influence on the stresses and ultimate load for the tensile test. It is concluded that waterjet cut holes result in lower characteristic ultimate loads and higher stresses. Due to the different edge finishing, the ultimate load still is lower compared to core drilled holes, even if the waterjet cut holes are perfectly round

Support for the global feasibility of the Ages and Stages Questionnaire as developmental screener

Objective: To investigate the psychometric properties of the Dutch version of the 48 months Ages and Stages Questionnaire (D_ASQ_48). Design: Prospective cohort study of a community-based sample of children born in 2002 and 2003 whose parents filled out the D_ASQ_48 and a questionnaire on school status at 60 months. The ASQ was translated into Dutch and back-translated into English by three independent translators. Setting: Well Child Centers covering 25% of the Netherlands. Participants: Parents of 1510 preterm and 562 term children born in 2002-2003 attending routine Well Child visits at age 45-50 months. Main outcome measures: Reliability, validity and mean population scores for D_ASQ_48 compared to other countries. Results: Mean population scores for the D_ASQ_48 were mostly similar to those in the USA, Norway and Korea. Exceptions (effect sizes of difference >0.5) were problem solving (USA) and fine motor (Korea). Reliability was good for the total score (Cronbach alpha 0.79) and acceptable for all domains (0.61-0.74). As expected, infants born at gestational age Conclusions: The good psychometric properties of the Dutch ASQ_48 and the small differences when compared to other countries support its usefulness in the early detection of developmental problems amongst children worldwide. (C) 2009 Elsevier Ireland Ltd. All rights reserved

Een verkenning van de betekenis van het Handvest van de Grondrechten van de Europese Unie voor het privaatrecht. Deel 2: De verhouding van het Handvest tot het EVRM en de meerwaarde van het Handvest

The Legitimacy and Effectiveness of Law & Governance in a World of Multilevel Jurisdiction

Photoperiodic response in the formation of gametangia of the long-day plant Sphacelaria rigidula (Phaeophyceae)

The effect of daylength and irradiance on the formation of gametangia in the male gametophyte of Sphacelaria rigidula Kutz (= S. furcigera Kutz [Prud'homme van Reine 19821) was investigated. Formation of gametangia was restricted to long-day conditions: In light-dark regimes with 12 h of light per day or less, no gametangia were formed. In long-day regimes high irradiances caused a suboptimal response, especially near the critical daylength. Interruption of a long dark period with a light break promoted gametangia formation. Light breaks were most effective when given at about the 6th hour of darkness. Nine inductive long-day cycles were required to induce the formation of gametangia, which appeared after ca. 15 d. The plants remained in the induced state only for a very short time. In regimes with very long days and at high irradiance the number of fertile plants decreased after some time, when vigorous vegetative growth started without any further formation of gametangia

Antigen-Specific B Cells Reactivate an Effective Cytotoxic T Cell Response against Phagocytosed Salmonella through Cross-Presentation

Background: The eradication of facultative intracellular bacterial pathogens, like Salmonella typhi, requires the concerted action of both the humoral immune response and the cytotoxic CD8 + T cell response. Dendritic cells (DCs) are considered to orchestrate the cytotoxic CD8 + T cell response via cross-presentation of bacterial antigens onto MHC class I molecules. Cross-presentation of Salmonella by DCs however, is accompanied by the induction of apoptosis in the DCs. Besides antibody production, B cells are required to clear Salmonella infection for other unknown reasons. Methodology/Principal Findings: Here we show that Salmonella-specific B cells that phagocytose Salmonella upon BCRligation reactivate human memory CD8 + T cells via cross-presentation yielding a Salmonella-specific cytotoxic T cell response. The reactivation of CD8 + T cells is dependent on CD4 + T cell help. Unlike the DCs, B cell-mediated crosspresentation of Salmonella does not coincide with apoptosis. Conclusions/Significance: B cells form a new player in the activation of the cytotoxic effector arm of the immune respons

Alpha, Betti and the Megaparsec Universe: on the Topology of the Cosmic Web

We study the topology of the Megaparsec Cosmic Web in terms of the scale-dependent Betti numbers, which formalize the topological information content of the cosmic mass distribution. While the Betti numbers do not fully quantify topology, they extend the information beyond conventional cosmological studies of topology in terms of genus and Euler characteristic. The richer information content of Betti numbers goes along the availability of fast algorithms to compute them. For continuous density fields, we determine the scale-dependence of Betti numbers by invoking the cosmologically familiar filtration of sublevel or superlevel sets defined by density thresholds. For the discrete galaxy distribution, however, the analysis is based on the alpha shapes of the particles. These simplicial complexes constitute an ordered sequence of nested subsets of the Delaunay tessellation, a filtration defined by the scale parameter, $\alpha$. As they are homotopy equivalent to the sublevel sets of the distance field, they are an excellent tool for assessing the topological structure of a discrete point distribution. In order to develop an intuitive understanding for the behavior of Betti numbers as a function of $\alpha$, and their relation to the morphological patterns in the Cosmic Web, we first study them within the context of simple heuristic Voronoi clustering models. Subsequently, we address the topology of structures emerging in the standard LCDM scenario and in cosmological scenarios with alternative dark energy content. The evolution and scale-dependence of the Betti numbers is shown to reflect the hierarchical evolution of the Cosmic Web and yields a promising measure of cosmological parameters. We also discuss the expected Betti numbers as a function of the density threshold for superlevel sets of a Gaussian random field.Comment: 42 pages, 14 figure

Growth of Preterm and Full-Term Children Aged 0-4 Years:Integrating Median Growth and Variability in Growth Charts

Objectives To assess the distribution of height, weight, and head circumference (HC) in preterm infants for ages 0-4 years, by gestational age (GA) and sex, and to construct growth reference charts for preterm-born children, again by GA and sex, for monitoring growth in clinical practice. Study design The community-based cohort study covered a quarter of The Netherlands. 1690 preterm infants (GA, 25-35(+6) weeks) and a random sample of 634 full-term control infants (GA 38-41(+6)), who were followed from birth to 4 years of age. Height, weight, and HC were regularly assessed during routine well-child visits and data were retrospectively collected. Results At all ages, the median height and weight of preterm children were lower compared with full-term children. Growth depended on the child's GA. Increase in HC showed an early catch-up and was similar to full-term children by the age of 1. Height, weight, and HC were more variable in boys, particularly in the very preterm children. Conclusions At 0 to 4 years, the growth of preterm children differed from that of full-term children and depended on their GA. The greater variability of growth in boys suggests that they are more vulnerable to the complications of preterm birth that influence growth. These growth charts are the most precise tools currently available for monitoring growth in preterm children. (J Pediatr 2012;161:460-5)

Developmental Delay in Moderately Preterm-Born Children at School Entry

Objective To determine the prevalence and nature of developmental delay at preschool age in infants born moderately preterm compared with those born full-term and early preterm. Study design Parents of 927 moderate preterm infants (32-35+6 weeks gestation), 512 early preterm infants (<32 weeks gestation) and 544 full-term infants (38-41+6 weeks gestation) completed the Ages and Stages Questionnaire (ASQ) when the child was aged 43-49 months. We analyzed rates of abnormal ASQ scores and odds ratios for abnormal ASQ scores in both preterm groups compared with the full-term group. We repeated the analyses after adjustment for socioeconomic status, sex, being part of a multiple birth, and small for gestational age status. Results Abnormal (ie, >2 SDs below the mean) ASQ total scores were noted in 8.3% of moderate preterm infants, in 4.2% of full-term infants, and in 14.9% of early preterm infants. ORs of abnormal ASQ total scores were 2.1 (95% CI, 1.3-3.4) for moderate preterm infants and 4.0 (95% CI, 2.4-6.5) for early preterm infants. Both moderate and early preterm infants had more frequent problems with fine motor, communication, and personal-social functioning compared with full-term infants. Compared with full-term infants, moderate preterm infants did not have a greater prevalence of problems with gross motor functioning and problem solving, whereas early preterms did. Socioeconomic status, small for gestational age status, and sex were associated with abnormal ASQ scores in moderate preterm infants. Conclusions At preschool age, the prevalence of developmental delay in moderate preterm infants was 2-fold of that in full-term infants and one-half of that in early preterm infants