Charged particle display

An optical shutter based on charged particles is presented. The output light intensity of the proposed device has an intrinsic dependence on the interparticle spacing between charged particles, which can be controlled by varying voltages applied to the control electrodes. The interparticle spacing between charged particles can be varied continuously and this opens up the possibility of particle based displays with continuous grayscale.Comment: typographic errors corrected in Eqs (37) and (39); published in Journal of Applied Physics; doi:10.1063/1.317648

Orchestration at the beginning: mitosis in sea urchin embryo

Development of multicellular organisms is driven by a series of mitotic divisions after fertilization. Total cytoplasmic volume does not increase during this process, resulting in an increasing number of smaller daughter cells. Cell divisions are initially synchronous in an early embryo, but this ends at the 16-cell stage in the sea urchin. Orchesterated mitosis does, however, continue in subpopulations via the coordination of two different processes: karyokinesis and cytokinesis. Part of this asynchrony is due to the differentiation of lineages.Fil: Abruzzese, Giselle Adriana. University of Chicago; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Tanpradit, Nae. University of Chicago; Estados UnidosFil: Tavares, Renata S.. University of Chicago; Estados Unido

Gun model classification based on fired cartridge case head images with siamese networks

The identification of the firearm model that triggered the firing of a bullet is an important forensic information that, historically, has been done by trained examiners through visual inspection using microscopes. This is an extensive and very time-consuming process that requires the examiners to be trained to identify and compare the fired cartridges. This paper proposes an automated objective method for binary classifying pairs of fired cartridge head images as belonging to the same or different classes, using siamese neural networks (SNNs). With this technique, an accuracy of up to 70% was reached by using firing pin mark images as the input of the SNN. For the training and optimization of the network this paper also analyses and presents different image preprocessing approaches.info:eu-repo/semantics/acceptedVersio

The Challenge of Educating Engineers for a Close, Crowded and Creative World

The world that is emerging based on the development and everyday use of new technologies is a world that can be described as close, crowded and creative. Studies have highlighted that traditional curricula and pedagogical methods for engineering education are deficient in terms of developing and nurturing key skills required by engineers to succeed in this world. The challenge for the engineering academic leaders of today is to begin with the end in mind: to begin with a description of the competences that the engineer of the future should have in order to succeed in their aspirations as an engineer, and then to reverse engineer both the curriculum and pedagogical approaches to enable the desired outcome. This chapter describes what is meant by a close, crowded and creative world: the world in which engineering graduates must learn to practice. It then proposes three different possible scenarios for the world of 2030 and discusses the key skills that engineers in 2030 should possess in order to succeed as engineers. The chapter concludes with recommendations on how to address the challenges of educating engineers for a close, crowded and creative world

Effets du calcium alimentaire sur les paramètres de reproduction de l’escargot Limicolaria flammea (Müller, 1774), en élevage hors-sol

De jeunes escargots Limicolaria flammea âgés de deux semaines, avec un poids vif moyen de 0,07 ± 0,01 g et une longueur moyenne de coquille de 7,50 ± 0,03 mm ont été soumis à cinq (5) régimes alimentaires dont deux à base de fourrages verts (R1: constitué par un mélange de feuilles de Lactuca sativa (Asteraceae) et de Palisota hirsuta (Commelinaceae) et R2: composé de feuilles de Carica papaya (Caricaceae) et de Phaulopsis falcisepala (Acanthaceae) et trois régimes concentrés sous forme de farine (R3, R4 et R5), de teneurs en calcium variables (6,82 %, 12,02 % et 16,01 % respectivement) en vue de déterminer le taux de calcium susceptible d’induire de meilleures performances de croissance. La reproduction de l’escargot L. flammea est fortement influencée par les teneurs en calcium des aliments qu’il consomme. Les régimes concentrés réduisent la durée du cycle sexuel, en ce sens que la maturité sexuelle qui est tardive (7 mois) avec les aliments végétaux (R1 et R2) a été rendue précoce (5 mois) avec ces aliments (R4 et R5). La teneur en calcium alimentaire influence le nombre total de pontes, la durée d’incubation et le taux d’éclosion des oeufs, alors qu’elle n’a pas d’effet sur le poids et les dimensions de l’oeuf. Le taux optimal de calcium induisant une meilleure reproduction varie de 12,02 % à 16,01 %. En outre, les animaux qui ont été nourris à ces régimes ont eu une relative longévité, un nombre élevé de pontes, une durée d’incubation réduite et un taux élevé d’éclosion des oeufs, contrairement aux régimes à base de fourrages verts qui donnent des résultats peu prometteurs.Mots-clés: calcium, escargot, Limicolaria flammea (Müller, 1774), reproduction. Effects of dietary calcium on the reproduction parameters of the snail Limicolaria flammea (Müller, 1774), under indoor rearing Some young snails of Limicolaria flammea species of two weeks old, with an average live weight of 0,07 ± 0,002 g and an average shell length of 7,5 ± 0,03 mm were subjected to five (5) diets including two containing green fodder (R1: constituted by a mixture of leaves of Lactuca sativa (Asteraceae) and Palisota hirsuta (Commelinaceae) and R2:composed by leaves of Carica papaya (Caricaceae) and Phaulopsis falcisepala (Acanthaceae) and three concentrated diets in the form of flour (R3, R4 and R5), of variable calcium contents (6,82 %, 12,02 % and 16,01 % respectively) in order to determine the calcium rate suitable for induce better growth performances.The study shows that the reproduction of the snail L flammea is strongly influenced by the calcium contents of the food which it consumes. The concentrated diets reduce the duration of the sexual cycle, in the sense that the sexual maturity which is late (7 months) with vegetable foods (R1 and R2) was made early (5 months) with these food (R4 and R5).The dietary calcium content influences the total number of clutches, the duration of incubation and the hatching rate, while it has no effect on the weight and dimensions of eggs. The optimal calcium levels inducing a better reproduction varies from 12,02 % to 16,01 %. Moreover, the animals which were nourished with these diets had a relative longevity, a high number of clutches, reduced incubation time and a high rate of hatching, contrary to the diets containing green fodder which give not very promising results.Keywords: calcium, Limicolaria flammea (Müller, 1774), reproduction, snail

Innovative learning at The University of Edinburgh

The activities available to civil engineering students during the University of Edinburgh's innovative learning week in 2012 were examined. The academic staff proposed a wide range of possible activities and student participation was optional. Popular activities were those with a ‘hands-on’ element: making or doing something. The practical activities offered included designing and building trebuchets, relaying railway permanent way on a heritage railway, practical workshops on engineering in international development and learning to juggle. These activities suggested that heuristic learning by trial and error was likely to enhance the visualisation skills that contribute to good engineering design. Further, the linking of achievement to purposeful practice rather than innate talent could inform teaching methods in the future. They also showed that in some cases safety culture messages were still not fully assimilated by students

Childhood Development after Cochlear Implantation (CDaCI) study: Design and baseline characteristics

Children with severe to profound sensorineural hearing loss face communication challenges that influence language, psychosocial and scholastic performance. Clinical studies over the past 20 years have supported wider application of cochlear implants in children. The Childhood Development after Cochlear Implantation (CDaCI) study is the first longitudinal multicentre, national cohort study to evaluate systematically early cochlear implant (CI) outcomes in children. The objective of the study was to compare children who have undergone cochlear implantation, with similarly aged hearing peers across multiple domains, including oral language development, auditory performance, psychosocial and behavioural functioning, and quality of life. The CDaCI study is a multicentre national cohort study of CI children and normal hearing (NH) peers. Eligibility criteria include informed consent, age less than 5 years, pre- or post-lingually deaf, developmental criteria met, commitment to educate the child in English and bilateral cochlear implants. All children had a standardised baseline assessment that included demographics, hearing and medical history, communication history, language measures, cognitive tests, speech recognition, an audiological exam, psychosocial assessment including parent-child videotapes and parent reported quality of life. Follow-up visits are scheduled at six-month intervals and include a standardised assessment of the full battery of measures. Quality assurance activities were incorporated into the design of the study. A total of 188 CI children and 97 NH peers were enrolled between November 2002 and December 2004. The mean age, gender and race of the CI and NH children are comparable. With regard to parental demographics, the CI and NH children's families are statistically different. The parents of CI children are younger, and not as well educated, with 49% of CI parents reporting college graduation vs. 84% of the NH parents. The income of the CI parents is also lower than the NH parents. Assessments of cognition suggest that there may be baseline differences between the CI and NH children; however the scores were high enough to suggest language learning potential. The observed group differences identified these baseline characteristics as potential confounders which may require adjustment in analyses of outcomes. This longitudinal cohort study addresses questions related to high variability in language outcomes. Identifying sources of that variance requires research designs that: characterise potential predictors with accuracy, use samples that adequately power a study, and employ controls and approaches to analysis that limit bias and error. The CDaCI study was designed to generate a more complete picture of the interactive processes of language learning after implantation. Copyright © 2007 John Wiley & Sons, Ltd.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/56091/1/333_ftp.pd