629 research outputs found
The visualisation on Pangolin scales using gelatine lifters
Recent media reports document the plight of the Pangolin and its current position as “the most trafficked mammal in the world”. They are described by some as scaly anteaters as all species are covered in hard keratinous tissue in the form of overlapping scales acting as a “flexible dermal armour”. It is estimated that between 2011 and 2013, 117,000 to 234,000 pangolins were slaughtered, but the seizures may only represent as little as 10% of the true volume of pangolins being illegally traded. In this paper, methods to visualise fingermarks on Pangolin scales using gelatine lifters is presented. The gelatine lifters provide an easy to use, inexpensive but effective method to help wildlife crime rangers across Africa and Asia to disrupt the trafficking. The gelatine lifting process visualised marks producing clear ridge detail on 52% of the Pangolin scales examined, with a further 30% showing the impression of a finger with limited ridge detail. The paper builds on an initial sociotechnical approach to establishing requirement, then it focuses on the methods and outcomes lifting
fingermarks off Pangolin scales using gelatine lifters, providing an evaluation of the viability of using the lifters in practice
The big picture? Video and the representation of interaction
Researchers who use video to record interactions usually need to translate the video data into another medium at some stage in order to facilitate its analysis and dissemination. This article considers some methodological issues that arise in this process by examining transcripts, diagrams and pictures as examples of different techniques for representing interaction. These examples are used to identify some general principles for the representation of data where video is the source material. The article presents an outline of guided interaction and this is used as a case for illustrating these principles in the context of young children, technology and adults in pre-school settings. Although the article focuses on a specific study and solution, the principles are applicable in all cases where video is used as a source of data for the representation of interaction, whether or not it is technologically mediated
Supporting learning with 3D interactive applications in early years
Early years education is an key element for the introduction of children in the education system. In order to improve this process, the aim of this study was to explore how guided interaction with 3D apps can fit into a preschool setting, how it can help children learn through playing and how it can improve their learning outcomes. A study was conducted with six classes of 87 students aged between 3 years to 6 years, over a 12-week period. Children used 10 inch Android tablets with a series of apps developed by our research team, about houses of the world, the skeleton & five senses and, animals. A quasi-experimental design based on a nonequivalent groups pretest and posttest de-sign revealed that an active behavior and better learning outcomes are obtained by children participating in the experimental groupCascales Martínez, A.; Martínez Segura, MJ.; Laguna- Segobia, M.; Pérez Lopez, DC.; Contero, M. (2014). Supporting learning with 3D interactive applications in early years. Lecture Notes in Computer Science. 8524:11-22. doi:10.1007/978-3-319-07485-6_2S11228524Plowman, L., Stephen, C.: Children, Play and Computers in Preschool Education. British Journal of Educational Technology 36(2), 145–157 (2005)Tootell, H., Plumb, M., Hadfield, C., Dawson, L.: Gestural Interface Technology in early childhood education: A framework for fully-engaged communication. In: Proceedings of the Annual Hawaii International Conference on System Sciences, art. no. 6479836, pp. 13–20 (2013)Marco, J., Cerezo, E.: Bringing Tabletop Technologies to Kindergarten Children. In: HCI 2009 International Conference on Human-Computer Interaction–Celebrating People and Technology, pp. 103–111. Springer, Heidelberg (2009)Heft, T.M., Swaminathan, S.: Using Computers in Early Childhood Classrooms: Teachers’ Attitudes, Skills and Practices. Journal of Early Childhood Research 6(4), 169–188 (2006)Wang, X.C., Ching, C.C.: Social Construction of Computer Experience in a First-Grade Classroom: Social Processes and Mediating Artifacts. Early Education and Development 14(3), 335–361 (2003)Couse, L.J., Chen, D.W.: A Tablet Computer for Young Children? Exploring Its Viability for Early Childhood Education. Journal of Research on Technology in Education 43(1), 75–98 (2012)Kearney, J.: Educating Young Children - Learning and Teaching in the Early Childhood Years. Early Childhood Teachers’ Association (ECTA Inc.) 3(18) (2012)Rankothge, W.H., Sendanayake, S.V., Sudarshana, R.G.P., Balasooriya, B.G.G.H., Alahapperuma, D.R., Mallawarachchi, Y.: Technology Assisted Tool for Learning Skills Development in Early Childhood. In: Proc. of 2012 International Conference on Advances in ICT for Emerging Regions (ICTer), pp. 165–168 (2012)Sandvik, M., Smørdal, O., Østerud, S.: Exploring iPads in Practitioners’ Repertoires for Language Learning and Literacy Practices In Kindergarten. Nordic Journal of Digital Literacy 3(7), 204–221 (2012)Priyankara, K.W.T.G.T., Mahawaththa, D.C., Nawinna, D.P., Jayasundara, J.M.A., Tharuka, K.D.N., Rajapaksha, S.K.: Android Based e-Learning Solution for Early Childhood Education in Sri Lanka. In: Proceedings of the 8th International Conference on Computer Science & Education (ICCSE), pp. 715–718 (2013)Zanchi, C., Presser, A.L., Vahey, P.: Next Generation Preschool Math Demo: Tablet Games for Preschool Classrooms. In: Proceedings of the 12th International Conference on Interaction Design and Children, IDC 2013, pp. 527–530 (2013)Meyer, B.: Game-based Language Learning for Pre-School Children: A Design Perspective. Electronic Journal of e-Learning 11(1), 39–48 (2013)Straub, D.W.: Validating Instruments in MIS Research. MIS Quarterly 13(2), 147–169 (1989)Cook, T.D., Campbell, D.T., Day, A.: Quasi-experimentation: Design and Analysis Issues for Field Settings, pp. 19–21. Houghton Mifflin, Boston (1979)Buendía, L., Y Berrocal, E.: La Ética de la Investigación Educativa. Ágora Digital 1 (2011)Tojar, J., Serrano, J.: Ética e Investigación Educativa. RELIEVE 6(2) (2000)Cascales, A., Laguna, I., Pérez-López, D., Perona, P., Contero, M.: 3D Interactive Applications on Tablets for Preschoolers: Exploring the Human Skeleton and the Senses. In: Hernández-Leo, D., Ley, T., Klamma, R., Harrer, A. (eds.) EC-TEL 2013. LNCS, vol. 8095, pp. 71–83. Springer, Heidelberg (2013
Evaluation of CyberKnife ® fiducial tracking limitations to assist targeting accuracy: A phantom study with fiducial displacement
Introduction The underlying assumptions of the CyberKnife® (Accuray, Sunnyvale, CA, US) fiducial tracking system are: i) fiducial positions are accurately detected; ii) inter-fiducial geometry remains consistent (rigid); iii) inter-fiducial geometric array changes are detected and either accommodated with corrections or treatment is interrupted. However: i) soft-tissue targets are deformable & fiducial migration is possible; ii) the accuracy of the tracking system has not previously been examined with fiducial displacement; iii) treatment interruptions may occur due to inter-fiducial geometric changes, but there is little information available to assist subsequent troubleshooting. The purpose of this study was to emulate a clinical target defined with a two, three, or four-fiducial array where one fiducial is displaced to mimic a target deformation or fiducial migration scenario. The objectives: evaluate the fiducial positioning accuracy, array interpretation, & corresponding corrections of the CyberKnife system, with the aim of assisting troubleshooting following fiducial displacement. Methods A novel solid-water phantom was constructed with three fixed fiducials (F1,F2,F3) & one moveable fiducial (F4), arranged as if placed to track an imaginary clinical target. Using either two fiducials (F1,F4), different combinations of three fiducials (F1,F2,F4; F1,F3,F4; F2,F3,F4) or four fiducials (F1,F2,F3,F4), repeat experiments were conducted where F4 was displaced inferiorly at 2-mm intervals from 0-16 mm. Data were acquired at each position of F4, including rigid body errors (RBE), fiducial x, y, & z coordinate displacements, six degrees of freedom (DOF) corrections, & robot center-of-mass (COM) translation corrections. Results Maximum positioning difference (mean±SD) between the reference and live x, y, & z coordinates for the three fixed fiducials was 0.08±0.30 mm, confirming good accuracy for fixed fiducial registration. For two fiducials (F1,F4), F4 registration was accurate to 14-mm displacement and the F4 x-axis coordinate change was 2.0±0.12 mm with each 2 mm inferior displacement validating the phantom for tracking evaluation. RBE was >5 mm (system threshold) at 6-14 mm F4 displacement: however, F1 was misidentified as the RBE main contributor. Further, F1/F4 false-lock occurred at 16 mm F4 displacement with corresponding RBE 13 mm. For combinations of three fiducials, F4 registration was accurate to 10-mm displacement. RBE was >5 mm at 6-16 mm F4 displacement: however, F4 false-lock occurred at 12-16 mm with RBE 5-6 mm. For four fiducials, F4 registration was accurate to 4 mm displacement: however, F4 false-lock occurred at 6-16 mm displacement with concerning RBE <2 & <5 at 6 & 8-mm F4 displacement, respectively. False-locks were easily identified in the phantom but frequently uncorrectable. Conclusions Results indicate fiducial positioning accuracy and system output following fiducial displacement depends on the number of fiducials correlated, displacement distance, and clinical thresholds applied. Displacements ≤4 mm were accurately located, but some displacements 6-16 mm were misrepresented, either by erroneous main contributor (two-fiducial array only) or by false-locks and misleading RBE, which underestimated displacement. Operator vigilance and implementation of our practical guidelines based on the study findings may help reduce targeting error and assist troubleshooting in clinical situations
An ecological exploration of the Internet of Toys in early childhood everyday life
Throughout this chapter, the focus is on the importance of children’s agency in their use of Internet of Toys (IoToys). We think about children’s capabilities as part of digitally mediated eco-communities. Informed by the socio-ecological model, children’s, practitioners’ and parents’ dispositions helped contextualise the factors that shape children’s use of IoToys. We provide the following key messages throughout the chapter: 1.A discussion of passivity or empowerment as part of children’s digital lives with IoToys, in line with Craft’s (2013) work. 2.A reanalysis of perceptions of childhood in the digital age, linking to the sociological models of childhood and the role of children as competent and agentic. 3.An account of socio-ecological influences on digital lives, likened to Rogoff’s (2008) three planes relating to individual, interpersonal and community alongside a discussion of how the interpersonal plane can be reimagined to include interactions between child and machine. 4.A note of caution against the passive child agenda and recurrent moral panic
Probing seed black holes using future gravitational-wave detectors
Identifying the properties of the first generation of seeds of massive black
holes is key to understanding the merger history and growth of galaxies.
Mergers between ~100 solar mass seed black holes generate gravitational waves
in the 0.1-10Hz band that lies between the sensitivity bands of existing
ground-based detectors and the planned space-based gravitational wave detector,
the Laser Interferometer Space Antenna (LISA). However, there are proposals for
more advanced detectors that will bridge this gap, including the third
generation ground-based Einstein Telescope and the space-based detector DECIGO.
In this paper we demonstrate that such future detectors should be able to
detect gravitational waves produced by the coalescence of the first generation
of light seed black-hole binaries and provide information on the evolution of
structure in that era. These observations will be complementary to those that
LISA will make of subsequent mergers between more massive black holes. We
compute the sensitivity of various future detectors to seed black-hole mergers,
and use this to explore the number and properties of the events that each
detector might see in three years of observation. For this calculation, we make
use of galaxy merger trees and two different seed black hole mass distributions
in order to construct the astrophysical population of events. We also consider
the accuracy with which networks of future ground-based detectors will be able
to measure the parameters of seed black hole mergers, in particular the
luminosity distance to the source. We show that distance precisions of ~30% are
achievable, which should be sufficient for us to say with confidence that the
sources are at high redshift.Comment: 14 pages, 6 figures, 2 tables, accepted for proceedings of 13th GWDAW
meetin
Orbital effects of a monochromatic plane gravitational wave with ultra-low frequency incident on a gravitationally bound two-body system
We analytically compute the long-term orbital variations of a test particle
orbiting a central body acted upon by an incident monochromatic plane
gravitational wave. We assume that the characteristic size of the perturbed
two-body system is much smaller than the wavelength of the wave. Moreover, we
also suppose that the wave's frequency is much smaller than the particle's
orbital one. We make neither a priori assumptions about the direction of the
wavevector nor on the orbital geometry of the planet. We find that, while the
semi-major axis is left unaffected, the eccentricity, the inclination, the
longitude of the ascending node, the longitude of pericenter and the mean
anomaly undergo non-vanishing long-term changes. They are not secular trends
because of the slow modulation introduced by the tidal matrix coefficients and
by the orbital elements themselves. They could be useful to indepenedently
constrain the ultra-low frequency waves which may have been indirectly detected
in the BICEP2 experiment. Our calculation holds, in general, for any
gravitationally bound two-body system whose characteristic frequency is much
larger than the frequency of the external wave. It is also valid for a generic
perturbation of tidal type with constant coefficients over timescales of the
order of the orbital period of the perturbed particle.Comment: LaTex2e, 24 pages, no figures, no tables. Changes suggested by the
referees include
Epidermal growth factor mediates spermatogonial proliferation in newt testis
The complex processes of spermatogenesis are regulated by various factors. The aim of the current study is to determine the effect of epidermal growth factor (EGF) on spermatogonial proliferation and clarify the mechanism causing the proliferation in newt testis. In the organ culture, EGF stimulated spermatogonial proliferation, but not their differentiation into spermatocytes. cDNA cloning identified 3 members of the EGF receptors, ErbB1, ErbB2, and ErbB4, in the testis. RT-PCR showed that all the receptors cloned were expressed in both Sertoli and germ cells at the spermatogonial stage. In the organ cultures with inhibitors for the EGF receptors, mitogen-activated protein kinase (MAPK), and phosphoinositide 3-kinase (PI3K), the EGF-induced spermatogonial proliferation was suppressed. Furthermore, when the organ culture was exposed to EGF, the expressions of stem cell factor (SCF), immunoglobulin-like domain containing neuregulin1 (Ig-NRG1), and ErbB4 mRNA were increased. These results suggested that, since the spermatogonia are sequestered within cysts by the blood-testis barrier consisted of Sertoli cells, EGF possibly mediates spermatogonial proliferation in an endocrine manner through the receptors including ErbB1, ErbB2, and ErbB4 expressed on Sertoli cells via activation of MAPK cascade or/and PI3K cascade by elevating the expressions of SCF, Ig-NRG1, and ErbB4
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