Assessing and monitoring student progress in e-learning environments

E-learning has emerged as a form of pedagogy and as a delivery system with broad implications for meeting personnel needs nationally in special education. At present, it is important to make investments in research and development to ensure that this new pedagogy becomes fully developed and is appropriately applied. Assessment and monitoring of student progress in e-learning environments is an important element of this new form of pedagogy that requires research attention to maximize the effectiveness of e-learning when applied to teacher education. The authors draw upon their personal online teaching experience in addressing strategies for assessing student performance and using electronic portfolios in e-learning environments, both presented as integral aspects of e-learning instructional process. Perspectives from the literature and lessons learned from the authors’ own experience are shared.peerreviewe

Arteries are formed by vein-derived endothelial tip cells

Tissue vascularization entails the formation of a blood vessel plexus, which remodels into arteries and veins. Here we show, by using time-lapse imaging of zebrafish fin regeneration and genetic lineage tracing of endothelial cells in the mouse retina, that vein-derived endothelial tip cells contribute to emerging arteries. Our movies uncover that arterial-fated tip cells change migration direction and migrate backwards within the expanding vascular plexus. This behaviour critically depends on chemokine receptor cxcr4a function. We show that the relevant Cxcr4a ligand Cxcl12a selectively accumulates in newly forming bone tissue even when ubiquitously overexpressed, pointing towards a tissue-intrinsic mode of chemokine gradient formation. Furthermore, we find that cxcr4a mutant cells can contribute to developing arteries when in association with wild-type cells, suggesting collective migration of endothelial cells. Together, our findings reveal specific cell migratory behaviours in the developing blood vessel plexus and uncover a conserved mode of artery formation.Supramolecular & Biomaterials Chemistr

Foliar Morphology And Anatomy Of The Gigantopterid Plant Delnortea Abbottiae, From The Lower Permian Of West Texas

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142005/1/ajb214202.pd

Über Bülow-Cummerow: Preußen, seine Verfassung, seine Verwaltung, sein Verhältniß zu Deutschland

von E. MeyenAbdr. aus: Eisenbahn. 5. 1842, No 33, 34 u. 3

Standardization of Solar Mirror Reflectance Measurements - Round Robin Test: Preprint

Within the SolarPaces Task III standardization activities, DLR, CIEMAT, and NREL have concentrated on optimizing the procedure to measure the reflectance of solar mirrors. From this work, the laboratories have developed a clear definition of the method and requirements needed of commercial instruments for reliable reflectance results. A round robin test was performed between the three laboratories with samples that represent all of the commercial solar mirrors currently available for concentrating solar power (CSP) applications. The results show surprisingly large differences in hemispherical reflectance (sh) of 0.007 and specular reflectance (ss) of 0.004 between the laboratories. These differences indicate the importance of minimum instrument requirements and standardized procedures. Based on these results, the optimal procedure will be formulated and validated with a new round robin test in which a better accuracy is expected. Improved instruments and reference standards are needed to reach the necessary accuracy for cost and efficiency calculations

Evidence for the presence of Legionella bacteriophages in environmental water samples.

&lt;p&gt;The existence and preliminary characterization of bacteriophages active against the Gram-negative human pathogen Legionella pneumophila, the causative agent of a very severe form of pneumonia, are reported. Four phages belonging to the family of the Myoviridae were isolated from various fresh water environments, and preliminary characterization showed that these crude preparations infect exclusively bacteria belonging to the genus Legionella. Standard phage amplification, purification, and characterization procedures were, however, not efficiently applicable making more research into these novel phages and their mechanism of infection necessary. The existence of Legionella bacteriophages is very promising for future applications such as the development of novel molecular tools, the design of new detection and typing methods, and the bioremediation of this environmental pathogen.&lt;/p&gt;</p

Führen viele Wege nach Rom? Berufssituation und Karrierestrategien des promovierten wissenschaftlichen Nachwuchses in der Kommunikations- und Medienwissenschaft

Im Fach Kommunikations- und Medienwissenschaft liegen bislang kaum empirische Daten zur Situation des promovierten wissenschaftlichen Nachwuchses vor. Diese Studie gibt Aufschluss über Beschäftigungssituation, Berufszufriedenheit, Betreuung sowie Karrierevorstellungen und -strategien der Post-Doktorandinnen und-Doktoranden des Faches. Die Ergebnisse einer Befragung im deutschsprachigen Raum zeigen, dass die Postdocs mit ihrer beruflichen Situation, vor allem mit den Arbeitsinhalten und der Flexibilität der Arbeitszeiten zufrieden sind und eine akademische Karriere anstreben. Die Konkurrenz und die Hürden auf dem Karriereweg werden allerdings als groß wahrgenommen. Zudem scheinen die als vielversprechend eingeschätzten Karrierestrategien wie das Publizieren in internationalen Fachzeitschriften nur schwer umsetzbar zu sein. Einzig jene Postdocs, die von ihrer/m vorgesetzten Professor/in beim Publizieren und beim Aufbau eines Netzwerks unterstützt und betreut werden, schaffen es, viel zu publizieren und international in Erscheinung zu treten. Hingegen sind zwei andere Gruppen weniger erfolgreich in der Umsetzung der eigenen Ziele bzw. verfolgen mit der Habilitation eher traditionelle Karrierestrategien