Improving classroom learning by collaboratively observing human tutoring videos while problem solving.

Collaboratively observing tutoring is a promising method for observational learning (also referred to as vicarious learning). This method was tested in the Pittsburgh Science of Learning Center’s Physics LearnLab, where students were introduced to physics topics by observing videos while problem solving in Andes, a physics tutoring system. Students were randomly assigned to three groups: (a) pairs collaboratively observing videos of an expert human tutoring session, (b) pairs observing videos of expert problem solving, or (c) individuals observing expert problem solving. Immediate learning measures did not display group differences; however, long-term retention and transfer measures showed consistent differences favoring collaboratively observing tutoring. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Incorporating in-cylinder pressure data to predict NOx emissions from spark-ignition engines fueled with landfill gas/hydrogen mixtures

A 0.745 L 2-cylinder spark-ignition engine was operated with compressed natural gas and with simulated landfill gas (60% CH₄ and 40% CO₂ by volume) containing hydrogen concentrations of 0, 30%, 40%, and 50% (by volume of the CH₄ in the fuel) at constant rpm. This empirical data was compared with predictions from three existing semi-empirical engine models, using a first-law-based finite heat release model to correlate measured in-cylinder pressure data and burn rate for each fuel mixture. Of the three models only a two zone model incorporating thermal and prompt NO_x came within 25% of predicting the measured NO_x emissions.     

Towards cognitive evaluation of computer-drawn sketches

This paper seeks to raise visual comparisons beyond subjective opinions into evidence-based visual reasoning. It provides an informal deductive analysis of the marks in sketches derived with two competing line-filtering algorithms. This prompted the novel speculation that the visual system might be placing some types of anomalies in the foreground of mental 3D space, where they can be ignored. A brief survey is provided to encourage informed debate. Although the proposed cognitive computation was not automated, it justified the rejection of the Douglas–Peucker algorithm in favour of Visvalingam's algorithm in subsequent research within the Cartographic Information Systems Research Group (CISRG).     

Institut für Maschinelles Sehen und Darstellen

Sciencenews10-Jahr-Feier

Institut für Maschinelles Sehen und Darstellen     

The min K channel underlies the cardiac potassium current IKs and mediates species-specific responses to protein kinase C

A clone encoding the guinea pig (gp) min K potassium channel was isolated and expressed in Xenopus oocytes. The currents, gpIsK, exhibit many of the electrophysiological and pharmacological properties characteristic of gpIKs, the slow component of the delayed rectifier potassium conductance in guinea pig cardiac myocytes. Depolarizing commands evoke outward potassium currents that activate slowly, with time constants on the order of seconds. The currents are blocked by the class III antiarrhythmic compound clofilium but not by the sotalol derivative E4031 or low concentrations of lanthanum. Like IKs in guinea pig myocytes, gpIsK is modulated by stimulation of protein kinase A and protein kinase C (PKC). In contrast to rat and mouse IsK, which are decreased upon stimulation of PKC, myocyte IK and gpIsK in oocytes are increased after PKC stimulation. Substitution of an asparagine residue at position 102 by serine (N102S), the residue found in the analogous position of the mouse and rat min K proteins, results in decreased gpIsK in response to PKC stimulation. These results support the hypothesis that the min K protein underlies the slow component of the delayed rectifier potassium current in ventricular myocytes and account for the species-specific responses to stimulation of PKC.     

Zur Frage der Entstehung von Nitrosaminen bei der Reaktion von Monosacchariden mit Aminos?uren (Maillard-Reaktion)

Zusammeufassung Zur Überprüfung des Auftretens von Nitrosaminen [2] im Rahmen der Maillard-Reaktion wurden die flüchtigen Produkte verschiedener Glucose-Aminosäure-Modell-gemische durch Kombination von Gaschromatographie and Massenspektrometrie, Polarographie und Dünnschicht-Chromatographie untersucht. Das Auftreten von Nitrosaminen kann durch die Ergebnisse eindeutig ausgeschlossen werden.

---

The problem of formation of nitrosamines by reacting monosaccharides with aminoacids (maillard-reaction)

Summary For proving the formation of nitrosamines applying maillardconditions [2] we tested the volatile reaction products of various glucose-aminoacid mixtures by coupling gas chromatography and mass spectrometry, polarography and thin-layer chromatography. The appearence of nitrosamines could undoubtedly be excluded according to the results.

     

Kinematisch bedingte Auswanderungserscheinungen bei periodisch schwingenden Waagen

Zusammenfassung W?gungen auf Hebelwaagen sind statische Messungen. Der Schwerkraft der zu w?genden Masse wird von der Waage eine konstante Me?kraft entgegengesetzt. Da sich jedoch innerhalb des selbstanzeigenden Bereichs die Me?kraft unter ?nderung des Ausschlags der Hebelkette selbst?ndig einstellt, bilden Waagen schwingungsf?hige Systeme, und zwar im allgemeinen nichtlineare Schwinger mit entsprechenden Eigenschaften. Unter diesen nimmt das Auswandern der Anzeige eine besondere Stellung ein, weil sich dabei die Mittellage der Schwingung gegenüber der statischen Gleichgewichtslage verschiebt. Diese Verschiebung kann von einem W?ger oder einem Me?wertgeber grunds?tzlich nicht erkannt werden und geht voll als Fehler in die W?gung ein.     

Particle emission by fission

We have investigated the sputtering by fission fragments of Cu, Al and Nb doped with 0.1 at % ²³⁵U and bombarded with thermal neutrons. This was primarily a search for micron-size particles emitted from the surfaces of the doped sources. Kaminsky et al. have observed large particles (several microns in size) emitted from the surface of samples bombarded by 14 MeV neutrons, with a maximum knock-on energy of 600 keV in Nb. The fission energy deposition of 200 MeV should be more than adequate to yield any observable effects that might be present at 600 keV. The concentration of fission events was 10 times the concentration of primary knock-ons in the Kaminsky experiments. With scanning electron microscope and energy dispersive X-ray analyses of our sputtering collectors both before and after irradiation, we found no sputtered particles larger than our detection limit of 0.1 μm.