Ecology in a walled city: researching urban wildlife in post-war Berlin

The division of Berlin in the aftermath of World War II and the erection of the Wall in 1961 were not only of tremendous political, social and cultural significance, but also had implications for the way in which science was undertaken in this city. For ecologists living and working in the enclosed city part of West Berlin, the lack of accessible countryside motivated them to focus their fieldwork increasingly on urban sites and, thereby, to engage themselves in one of the most significant attempts to develop an ecology of the city.     

Knowledge transfer by sharing task templates: two approaches and their psychological requirements

This paper considers two paradigms of process-aware information systems (PAIS) that are used to share knowledge about planning and executing tasks. The case-based task management (CBTM) system is based on the transduction of execution protocols, so-called cases; and the pattern-based task management (PBTM) system is based on task patterns that are derived from cases but yield more abstract information. As user motivation to contribute to a collaborative task management system is a crucial factor for its success, we consider the different motivational requirements of CBTM and PBTM from a psychological point of view. Based on experimental findings about different factors that have been shown to enhance people's motivation to contribute their knowledge to a shared pool, we compare the two approaches and assess which one is more appropriate with respect to motivation.     

Mathematics Instruction in Safe Space: Prospective Elementary Teachers' Views of Mathematics Education

This article discusses findings from an investigation into 42 prospective elementary teachers' views of mathematics teaching and learning. The focus is on how the participants saw the roles of teachers, pupils,and mathematics in mathematics classes as they communicated their views in journals written during the study. I argue that some prospective teachers express a tendency to protect and relieve their future pupils from mathematics. I show how this tendency affects a shift from school being the place where teachers teach pupils toward a conception of a safe space where the teachers predominantly care for the children. This revised version was published online in September 2006 with corrections to the Cover Date.     

Physical and metabolic demands of training and match-play in the elite football player

In soccer, the players perform intermittent work. Despite the players performing low-intensity activities for more than 70% of the game, heart rate and body temperature measurements suggest that the average oxygen uptake for elite soccer players is around 70% of maximum (VO(2max). This may be partly explained by the 150 - 250 brief intense actions a top-class player performs during a game, which also indicates that the rates of creatine phosphate (CP) utilization and glycolysis are frequently high during a game. Muscle glycogen is probably the most important substrate for energy production, and fatigue towards the end of a game may be related to depletion of glycogen in some muscle fibres. Blood free-fatty acids (FFAs) increase progressively during a game, partly compensating for the progressive lowering of muscle glycogen. Fatigue also occurs temporarily during matches, but it is still unclear what causes the reduced ability to perform maximally. There are major individual differences in the physical demands of players during a game related to physical capacity and tactical role in the team. These differences should be taken into account when planning the training and nutritional strategies of top-class players, who require a significant energy intake during a week.     

Kollektionsunterstützung für SQL:1999

Zusammenfassung. Kollektionen wie Mengen, Listen und Felder spielen in objektorientierten Anwendungen und Datenbanken eine wichtige Rolle. Dementsprechend sollten sie zusammen mit anderen objektrelationalen Konzepten auch in die aktuelle Datenbanknorm SQL:1999 eingebracht werden. Aus Aufwands- und Zeitgründen wurden jedoch vom Normungsgremium, zu dem auch die Vertreter wichtiger Hersteller kommerzieller (objekt-)relationaler Datenbankmanagementsysteme gehören, zunächst nur Felder (Arrays) berücksichtigt; andere Kollektionsarten sollen erst später folgen. Auch in wichtigen DBMS-Produkten werden Kollektionen bislang nur unzureichend und auf heterogene Art und Weise unterstützt. Dieser Beitrag beschäftigt sich mit den Möglichkeiten einer Ergänzung von SQL:1999 um wichtige Kollektionsarten. Basierend auf dem aktuellen Stand von Norm und Produkten werden prinzipielle Fragen der Integration in SQL diskutiert und die Grundlagen einer adäquaten Unterstützung von Kollektionen erörtert. Der formale Sprachvorschlag auf Basis von SQL:1999 kann hier aus Platzgründen nicht näher vorgestellt werden, einige Beispiele sollen aber die Anwendung der neuen Modellierungsmöglichkeiten verdeutlichen. Eingegangen am 15. Februar 2002/Angenommen am 10. September 2002CR Subject Classification H.2.1, H.2.3, H.2.4, D.3.3     

Loneliness and physical activity: A systematic review

This article aims to provide an overview of the current state of research on the relationship between loneliness and physical activity (PA). A systematic literature search was conducted to identify all empirical studies assessing this relationship. A total of 37 studies stemming from 36 publications met the inclusion criteria. Study analyses comprised an individual consideration of each study and a systematic summarization of the studies. The majority of eligible studies focused on adolescent or elderly populations. Direct negative associations between PA and loneliness were found in half of the 24 cross-sectional studies. Of the seven identified longitudinal studies, one found a direct negative influence of PA on loneliness. Four longitudinal studies found evidence for a reverse influence, namely of loneliness on PA. Five intervention studies found PA to reduce loneliness. Two of the cross-sectional studies and one of the intervention studies found social support and social competence to moderate or to mediate the relationship between PA and loneliness. The findings indicate that PA can contribute to a decrease in loneliness. However, studies also indicate that any beneficial effect is dependent upon the quality of relationships present during physical activity. Additionally, loneliness itself might reduce the probability of being physically active.     

The elitism dispositif: hierarchization,discourses of excellence and organizational change in European economics

From the 1990s onwards, economics departments in Europe have changed toward a culture of “excellence.” Strong academic hierarchies and new forms of academic organization replace “institutes” and “colleges” by fully equipped “economics departments.” This article seeks to demonstrate how and why hierarchization, discourses of excellence and organizational change takes place in European economics departments. The concept of “elitism dispositif” will be developed in order to understand these changes as a discursive as well as power-related phenomenon based on rankings, on the formation of new academic classes as well as on the construction of an elite myth. An elitism dispositif is defined as a discursive power apparatus that transforms symbolic differences among researchers, constructed by rankings, into material inequalities, based on an unequal distribution of academic capital between departments and researchers. Based on an empirical study, the article will focus on a selection of economics departments in Germany and in the UK, in order to study the emergence of an “elite class” as well as the functioning of an “excellence culture” that is based on discourses of power and inequality.     

Renal lactate elimination is maintained during moderate exercise in humans

Reduced hepatic lactate elimination initiates blood lactate accumulation during incremental exercise. In this study, we wished to determine whether renal lactate elimination contributes to the initiation of blood lactate accumulation. The renal arterial-to-venous (a-v) lactate difference was determined in nine men during sodium lactate infusion to enhance the evaluation (0.5 mol x L(-1) at 16 ± 1 mL x min(-1); mean ± s) both at rest and during cycling exercise (heart rate 139 ± 5 beats x min(-1)). The renal release of erythropoietin was used to detect kidney tissue ischaemia. At rest, the a-v O(2) (CaO(2)-CvO(2)) and lactate concentration differences were 0.8 ± 0.2 and 0.02 ± 0.02 mmol x L(-1), respectively. During exercise, arterial lactate and CaO(2)-CvO(2) increased to 7.1 ± 1.1 and 2.6 ± 0.8 mmol x L(-1), respectively (P < 0.05), indicating a -70% reduction of renal blood flow with no significant change in the renal venous erythropoietin concentration (0.8 ± 1.4 U x L(-1)). The a-v lactate concentration difference increased to 0.5 ± 0.8 mmol x L(-1), indicating similar lactate elimination as at rest. In conclusion, a -70% reduction in renal blood flow does not provoke critical renal ischaemia, and renal lactate elimination is maintained. Thus, kidney lactate elimination is unlikely to contribute to the initial blood lactate accumulation during progressive exercise.