Casting a Wider Net: Deepening Scholarship by Changing Theories

Research questions are shaped, explicitly or implicitly, by the theories we bring to bear upon our scholarship. Broadening our theoretical perspectives allows us to frame richer, deeper questions about the teaching and learning happening in our classrooms. This paper explicates the research implications of three broad theories of learning (constructivist, socio-cultural, and complexivist), exploring what scholarship framed by each theory might look like and some of the strengths and limitations of each framework. The authors use their experience engaging in research on teaching and learning in an undergraduate interdisciplinary science program to illustrate the argument that changing theories can help improve the scholarship and practice of teaching and learning in higher education

Processing and Structure of the Lantibiotic Peptide Nso From the Human Gut Bacterium Blautia obeum A2-162 analysed by Mass Spectrometry

A previously reported gene cluster encoding four nisin-like peptides, three with the same sequence (NsoA1-3) and the unique NsoA4, produced antimicrobial activity in the presence of trypsin after heterologous expression in Lactococcus lactis. Protein extracts were separated by SDS gel electrophoresis or immunoprecipitation using an antibody to the NsoA2 leader. Tryptic peptides observed by LC-MS/MS covered the complete sequence of preNsoA1-3 and part of the leader sequence of preNsoA4 and confirmed the expression and the predicted sequences of the preNsoA peptides. Further, the data revealed that the preNsoA1-3 peptides were partly modified with dehydrations and formation of lanthionine rings. A certain amount of fully modified preNsoA1-3 was observed. Details of modifications of the core peptide and the C-terminal tryptic peptide TATCGCHITGK covering rings D and E indicated that 22% of these preNsoA1-3 peptides were completely modified. A lower amount of ring formation is estimated for rings A-C. Intact masses of immunoprecipitation-derived peptides determined by LC-MS accurately matched the expected preNsoA precursor peptides. The most abundant peptides detected were preNsoA2-3-8H2O followed by preNsoA1-8H2O and other states of dehydration. The results confirm incomplete processing of preNsoA peptides in the heterologous system, with the formation of a certain amount of fully modified peptides

Scaling Behaviour of Si-alloyed Steel Slabs under Reheating Conditions

Reheating of steel slabs for further processing such as hot rolling usually takes place in gas-fired pusher furnaces. Temperatures well above 1000°C, combined with an atmosphere containing H2O, CO2, and O2, lead to substantial oxidation of most steel grades. Newly developed advanced steels often contain significant amounts of Si. This element plays a dominant role in the scaling behaviour near the steel-scale-interface, since fayalite (Fe2SiO4) forms a eutectic with wuestite (Fe1–xO) that melts as low as 1177°C.To better understand the high temperature oxidation behaviour, lab-scale trials were performed with different steel grades containing up to 3 wt.% Si. Possible interactions of Si with other alloying elements present in the samples such as Cr, Mn and Al were also of interest. The atmosphere contained 20% H2O, 7% CO2, and 3% O2, resembling reheating conditions in pusher furnaces, and temperatures ranged from 1100 to 1240°C. For metallographic investigation, the oxidised samples were cold mounted under vacuum using taper section angles. After preparation, the sections were examined through light microscopy, SEM/EDS, XRD, and TEM. The local distribution of the alloying elements could be mapped efficiently, and phase identification was successful in most parts. Under the applied experimental conditions, the elements of interest were present in their oxidic form either as pure or as mixed oxides. Higher Si-contents led to an increased build-up of eutectic melting phase at the steel-scale-interface at temperatures above 1177°C, which in turn further accelerated the oxidation

Experiments with a Decision-Theoretic Scheduler*

Abstract This paper describes DTS, a decisiontheoretic scheduler designed to employ stateof-the-art probabilistic inference technology to speed the search for efficient solutions to constraint-satisfaction problems. Our approach involves assessing the performance of heuristic control strategies that are normally hard-coded into scheduling systems, and using probabilistic inference to aggregate this information in light of features of a given problem. BPS, the Bayesian Problem-Solver [2], introduced a similar approach to solving singleagent and adversarial graph search problems, yielding orders-of-magnitude improvement over traditional techniques. Initial efforts suggest that similar improvements will be realizable when applied to typical constraint-satisfaction scheduling problems. Background Scheduling problems arise in schools, in factories, in military operations and in scientific laboratories. Although many algorithms have been proposed, scheduling remains among the most difficult of optimization problems. Because of the problem's ubiquity and complexity, small improvements to the state-of-the-art in scheduling are greeted with enormous interest by practitioners and theoreticians alike. A large class of scheduling problems can be represented as constraint-satisfaction problems (CSPs), representing attributes of tasks and resources as variables. Task attributes include the scheduled time for the task (start and end time) and its resource requirements. A schedule is constructed by assigning times and resources to tasks, while obeying the constraints *This research was supported by the National Aeronautics and Space Administration under contract NAS2-13340. of the problem. Constraints capture logical requirements (a typical resource can be used by only one task at a time) and problem requirements (task T~ requires N units of time, must be completed before task Tv, and must be completed before a specified date). One common approach to finding an assignment for the variables employs a preprocessing stage which tightens the constraints (e.g., by composing two constraints to form a third), followed by a backtrack search to find a satisfying assignment

Globalisierung und regionale Integration: Ökonomische Entwicklungen, Perspektiven und Grenzen

Eine zentrale vertretende These der Ökonomie lautet: Die Aufhebung von Beschränkungen im Handel und Kapitalverkehr weltweit vermehrt die Wohlfahrt. Internationale Abkommen und Zollunionen verfolgen das Ziel des Freihandels. Auch das europäische Integrationsprojekt basiert mit dem Binnenmarktprogramm und den vertraglich abgesicherten vier Freiheiten, für Handel, Kapital, Personen und Dienstleistungen, auf dieser Grundidee. Im Rahmen der EU wird dies noch durch die Währungsunion ergänzt. Aber an der These der wohlfahrtssteigernden Wirkung des Freihandels gibt es vermehrt Kritik. Die Finanz- und Eurokrisen haben zusätzlich die Debatten über die Erweiterung und Vertiefung der EU einschließlich der Europäischen Währungsunion verstärkt. Auch wirft das geplante transatlantische Freihandelsabkommen grundsätzliche Fragen von Grenzen der ökonomischen Integration auf. Zu diesen Themen fand vom 10. bis 12. Juli 2015 eine wissenschaftliche Tagung unter der Leitung von Wolfgang Quaisser in der Akademie für Politische Bildung Tutzing statt. Einige der dort vorgestellten Vorträge werden hier veröffentlicht