Zur Konzeption und Entwicklung interdisziplinärer Lern- programme am Beispiel eines Lernmoduls zur Psycholinguistik

Der folgende Beitrag beschäftigt sich mit fachbezogener Fachsprachenvermittlung unter dem Aspekt der Entwicklung, Nutzung und Evaluation neuer Technologien. Hierzu wurde ein Modul zur Vermittlung der Fachsprache der Psycholinguistik entwickelt und auf die Akzeptanz der Inhalte des entwickelten Mediums durch die Zielgruppe getestet und evaluiert. Das Ziel dieser deskriptiv-explorativen Pilot-Studie ist, die computer- gestützte Lernumgebung der Fachsprache der Psycholinguistik im Speziellen und in Verbindung mit unter- schiedlichen Fächerbezügen zu testen und zu evaluieren. Die gewonnenen Ergebnisse sollen in die Fertigstellung des Lernmoduls einfließen. Im Sinne eines neueren Evaluations- und Entwicklungsmodells wird durch die formative Evaluation versucht, die theoretischen Annahmen der Programmentwicklung sowie des Vermittlungsansatzes zu überprüfen und modifizieren. Für den empirischen Teil der Studie wurden 15 ausländische Studierende der Psycholinguistik an der Ludwig-Maximilians-Universität in München rekrutiert. Das Testen und die persönliche Befragung der Testpersonen wurde innerhalb eines Zeitraums von drei Wochen realisiert. Die Untersuchung zeigt, dass sowohl die inhaltliche als auch die technische Programmkonzeption positive Akzeptanz erfuhr und der lerntheoretische Rahmen der Lernprogrammkonzeption sowie der didaktische Rahmen der Lernzielvermittlung tendenziell den Lerner-dispositionen entgegenkommt. Daraus lassen sich Hinweise und Konsequenzen für die weitere Entwicklung des Online-Programms http://www.uni-deutsch.de/ erschließen

West-Nile virus replicon particles infect 293T cells expressing DC-SIGNR

West-Nile virus (WNV) is an arbovirus usually transmitted to humans via a mosquito vector. Infections commonly result in febrile symptoms while rare severe neuroinvasive cases may result in encephalitis or meningitis. Studies have shown that WNV infection efficiency is enhanced by expression of DC-SIGNR on target cells, which normally do not express DC-SIGNR. To investigate WNV tropism, we established 293T kidney epithelial cell lines that stably express vector, DC-SIGNR and mutants of DC-SIGNR that lack the entire carbohydrate-recognition domain (CRD) or lack the C-terminal half of the CRD. We demonstrate successful surface expression of DC-SIGNR and its mutants from stablytransfected 293T cells, but not vector-transfected 293T cells. Further, we show that monoclonal antibody 120604 which binds specifically to the DC-SIGNR CRD binds to DCSIGNR expressing 293T cells, but not to vector nor any of the DC-SIGNR mutants expressing cells. Virus replicon particles (VRPs), replication-incompetent viral particles containing necessary structural proteins for infection and a viral plasmid including a GFP reporter are used to safely and conveniently study viral entry. Entry assays using WNV (NY99) VRPs as well as a variant of WNV (NY99) which contains the beta-lactamase enzyme show significant entry into DC-SIGNR expressing cell lines, but not in controls that do not express DC-SIGNR. Additionally, we show that WNV VRPs do not enter DC-SIGNR expressing cells that lack the CRD or the C-terminal half of the CRD suggesting that the Cterminal half of the CRD is required for successful entry of WNV via DC-SIGNR. Future experiments may be able to shed light on which amino acids are required for entryhttps://openriver.winona.edu/urc2018/1057/thumbnail.jp

Register Allocation Via Coloring of Chordal Graphs

Abstract. We present a simple algorithm for register allocation which is competitive with the iterated register coalescing algorithm of George and Appel. We base our algorithm on the observation that 95 % of the methods in the Java 1.5 library have chordal interference graphs when compiled with the JoeQ compiler. A greedy algorithm can optimally color a chordal graph in time linear in the number of edges, and we can eas-ily add powerful heuristics for spilling and coalescing. Our experiments show that the new algorithm produces better results than iterated regis-ter coalescing for settings with few registers and comparable results for settings with many registers.

Register Allocation After Classical SSA Elimination is NP-Complete

Abstract. Chaitin proved that register allocation is equivalent to graph coloring and hence NP-complete. Recently, Bouchez, Brisk, and Hack have proved independently that the interference graph of a program in static single assignment (SSA) form is chordal and therefore colorable in linear time. Can we use the result of Bouchez et al. to do register allocation in polynomial time by first transforming the program to SSA form, then performing register allocation, and finally doing the classical SSA elimination that replaces φ-functions with copy instructions? In this paper we show that the answer is no, unless P = NP: register allocation after classical SSA elimination is NP-complete. Chaitin’s proof technique does not work for programs after classical SSA elimination; instead we use a reduction from the graph coloring problem for circular arc graphs.

Written Feedback in English - Teachers' Practices and Cognition

This study deals with written feedback on pupils’ written texts and teachers’ assessment practices and cognition. Providing effective, written feedback is a complex process that requires knowledge of the competency goal and development of methods for reducing the gap between pupil’s current status and pupil’s preferred state. Effective feedback is feedback that enhances pupils’ learning. In order to enhance learning feedback should contain information related to the following questions: “Where am I going?”; “How am I going?”; “Where to next?” The answers to these questions provide feed up, feed back and feed forward. The three questions must be connected in order to result in pupils’ greater achievement. The data in this study consists of written feedback collected from teachers at an upper secondary school. The main objective of the study was to examine what kind of written feedback teachers provide to help their pupils further. The feedback texts were analyzed according to Kronholm-Cederberg’s Response Triangle, divided into global and local text levels, and the terms defined above. Eight semi-standardized interviews were also conducted in order to examine teachers’ assessment practices and cognition. It is my experience that teachers’ responses contained elements at both the local and global text levels with the exception of context at the global level. In terms of the three questions mentioned above, most responses contained clear information about feed back and feed forward, however, there is a lack of feed up (goals) in most of the written feedback texts. This is unfortunate since feed up must be clear in order for pupils to develop further and increase their learning. This study also showed that teachers in general know much about assessment. However, there seems to be a tension between teachers’ knowledge and their practices. Teachers do not always tend to do what they know and believe

Compiling Java for high performance and the Internet

Java is the first widely accepted language that addresses heterogeneous resources, security, and portability problems, making it attractive for scientific computation. It also encourages programmers to use object-oriented techniques in programming. Unfortunately, such object-oriented programs also incur unacceptable performance penalties. For example, using a polymorphic number hierarchy in a linear algebra package resulted in a code that is four times shorter, more extensible and less bug-prone than the equivalent Fortran-style code, but also many times slower. To address the poor performance problem, this dissertation introduces several new compilation techniques that can improve the performance of scientific Java programs written in a polymorphic, object oriented style to within a factor of two of the equivalent hand-coded Fortran-style programs. These techniques also maintain an acceptable level of Java byte-code portability and flexibility, thus rewarding, rather than penalizing, good object-oriented programming practice. This dissertation first discards the typical one-class-at-a-time Java compilation model for a whole-program model. It then introduces two novel whole-program optimizations, class specialization and object inlining, which improve the performance of high-level, object-oriented, scientific Java programs by up to two orders of magnitude, effectively eliminating the penalty of object-oriented design. Next, this dissertation introduces a new Almost-whole-program compilation model. This model improves the flexibility of the generated code, while still permitting whole-program optimizations and incurring only modest performance penalties. It enables the programmer balance performance and flexibility of the program after the development phase, instead of compromising the design for performance. Furthermore, this dissertation reduces the restrictions that Java imposes upon classical optimization techniques by introducing exception hiding and SSA conversion algorithms. Exception hiding transforms the code to create exception-free zones, in which code motion transformations can move the code without restraint. The new, nearly linear-time SSA-to-CFG conversion algorithm considerably reduces the number of copies inserted in the conversion process, improving the effectiveness of classical optimizations. Finally, this dissertation lays the groundwork for further research, particularly for fast register allocation, precise type analysis, coordinated compilation, and exception recovery