Online etude center

Cyprus International Conference on Educational Research (CY-ICER-2012) North Cyprus, US08-10 February, 2012In this paper, we describe a system called Online Etude Center based on the subject, using technology in educational life. The system that we developed is a desktop application that can be used via tablet pc or mobile devices. By this study, it is expected to benefit from technological products so that we could achieve an educational life which is more entertaining and flexible. Through Online Etude Center, we believe in that teachers and students will easily communicate with each other. The application is developed using Microsoft C# as programming language and SQL Server as database. In addition, it can be used in portable devices such as tablet pc (with Windows 7 OS) and mobile devices (with Windows Mobile OS). This study mainly focuses to benefit from the advantages of technology in education and aims increasing the rate of technology usage in education system

Nanobodies as novel tools to study morphogen function "in vivo"

Nanobodies are small, monomeric antibody mimetic proteins produced by members of the camelid family (camels and llamas), that can be engineered by fusion to proteins carrying a specific function. These “functionalized” protein binders emerge as novel tools for protein manipulation in vivo. During my PhD studies I have generated scaffold-bound nanobodies (SBNs) specific to EGFP in order to interfere with gradient formation of a EGFP-tagged version of the Decapentaplegic (EGFP::Dpp) morphogen. Morphogens are secreted signaling molecules forming concentration gradients and controlling organ patterning and growth during animal development. Drosophila Decapentaplegic (Dpp) is one of the best studied morphogens, but it remains unclear how its concentration gradient is established and how it and controls patterning and growth of the Drosophila wing imaginal disc. In this PhD Thesis I summarize the development and characterization of SBNs and their applications in studying the formation and function of the Decapentaplegic morphogen gradient in the Drosophila melanogaster wing imaginal disc. In the first part of this Thesis, I will discuss how SBNs allowed us to investigate the importance of the Dpp gradient on proliferation and growth control of the wing imaginal disc. Using morphotrap, a SBN that localizes to the outer cell surface, we could completely block gradient formation and study the effect of a loss of the Dpp gradient on patterning and growth. We find that induction of Dpp target genes, and hence patterning, directly depends on the spreading of Dpp. Furthermore, we show that the Dpp gradient is crucial for growth and size control of the medial wing disc region. Moreover, we find that the Dpp gradient is not necessary for proliferation and size control of the lateral region of the wing disc. This data challenges previously published growth models, in which growth control solely depends on the signaling dynamics of Dpp. In the second part of this Thesis I investigate the mechanism of Dpp gradient formation in the wing disc. The wing disc is a complex three-dimensional structure, consisting of two contiguous epithelial layers. How the long-range Dpp gradient is established in the wing disc remains controversial. I have created different SBNs that localize to specific subcellular regions along the apicobasal axis. These SBNs allow us to reduce or block the dispersal of specific gradient subfractions and assess their contribution to wing development. We find that EGFP::Dpp disperses along three main routes: within the epithelial plane of the wing disc, in the luminal cavity between the two epithelial layers and along the basal lamina. Preliminary results suggest that these subfractions encode for different functions of Dpp. While we find that the patterning function of Dpp is encoded by the basolateral subfractions, the growth function of Dpp seems to be influenced by all three subfraction. Further experiments will investigate how target cells perceive and integrate Dpp input from these different subfractions

Myosin II is not required for Drosophila tracheal branch elongation and cell intercalation

The Drosophila tracheal system consists of an interconnected network of monolayered epithelial tubes that ensures oxygen transport in the larval and adult body. During tracheal dorsal branch (DB) development, individual DBs elongate as a cluster of cells, led by tip cells at the front and trailing cells in the rear. Branch elongation is accompanied by extensive cell intercalation and cell lengthening of the trailing stalk cells. Although cell intercalation is governed by Myosin II (MyoII)-dependent forces during tissue elongation in the Drosophila embryo that lead to germ-band extension, it remained unclear whether MyoII plays a similar active role during tracheal branch elongation and intercalation. Here, we have used a nanobody-based approach to selectively knock down MyoII in tracheal cells. Our data show that, despite the depletion of MyoII function, tip cell migration and stalk cell intercalation (SCI) proceed at a normal rate. This confirms a model in which DB elongation and SCI in the trachea occur as a consequence of tip cell migration, which produces the necessary forces for the branching process

TurbEFA: an interdisciplinary effort to investigate the turbulent flow across a forest clearing

the atmosphere within turbulence closure models is mainly limited by a realistic three-dimensional (3D) representation of the vegetation architecture. Within this contribution we present a method to record the 3D vegetation structure and to use this information to derive model parameters that are suitable for numerical flow models. A mixed conifer forest stand around a clearing was scanned and represented by a dense 3D point cloud applying a terrestrial laser scanner. Thus, the plant area density (PAD) with a resolution of one cubic meter was provided for analysis and for numerical simulations. Multi-level high-frequency wind velocity measurements were recorded simultaneously by 27 ultrasonic anemometers on 4 towers for a period of one year. The relationship between wind speed, Reynolds stress and PAD was investigated and a parametrization of the drag coefficient CD by the PAD is suggested. The derived 3D vegetation model and a simpler model (based on classical forest assessments of the site) were applied in a boundary layer model (BLM) and in large-eddy simulations (LES). The spatial development of the turbulent flow over the clearing is further demonstrated by the results of a wind tunnel experiment. The project showed, that the simulation results were improved significantly by the usage of realistic vegetation models. 3D simulations are necessary to depict the influence of heterogeneous canopies on the turbulent flow. Whereas we found limits for the mapping of the vegetation structure within the wind tunnel, there is a considerable potential for numerical simulations. The field measurements and the LES gave new insight into the turbulent flow in the vicinity and across the clearing. The results show that the zones of intensive turbulence development can not be restricted to the locations found in previous studies with more idealized canopies

Formation of polarized contractile interfaces by self-organized Toll-8/Cirl GPCR asymmetry

International audienc

TurbEFA: Ein interdisziplinärer Ansatz zur Untersuchung der turbulenten Strömung an einer Waldlichtung

Waldökosysteme spielen eine bedeutende Rolle in der Interaktion zwischen Landoberfläche und Atmosphäre. Ein besseres Verständnis der Austauschprozesse ist unter anderem notwendig für eine Einschätzung der Absorption und Emission von Spurenstoffen (z.B. CO2) und der Risiken von Waldschäden durch Wind, Frost und Dürre. Heutige Studien zur Rolle von terrestrischen Ökosystemen im Wasser- und Kohlenstoffkreislauf basieren auf langfristigen Messungen des Energie- und Massenaustausches zwischen Vegetation und Atmosphäre durch die Eddy-Kovarianz Methode (Goulden et al. 1996). Mehr als 500 Standorte weltweit sind derzeit in FLUXNET organisiert, einem internationalen Netzwerk (Baldocchi et al. 2001) zur kontinuierliche Messungen des Stoff- und Energieaustausches nach standardisierten Methoden (Aubinet et al. 2000). Der Austausch von Waldökosystemen wird dabei an einem Messturm durch eine Punktmessung über dem Bestand bestimmt, die eine bestimmte häufig komplexe Quellfläche repräsentiert. Mehr als drei Dekaden der Forschung in Feldexperimenten und Modellierung haben gezeigt, dass verbleibende Unsicherheiten vor allem durch räumliche Inhomogenität des Austausches begründet sind. Insbesondere fehlen Ansätze für eine geeignete Parametrisierung dieser Inhomogenitäten in numerischen Modellen

Forward and feedback control mechanisms of developmental tissue growth

International audienc