Das Projekt "Virtuelle Universität Mathematikunterricht" : eine HTML-basierte Lernumgebung zu neuen Medien für den Mathematikunterricht im Rahmen einer integrativen Medienpädagogik

Das Projekt "Virtuelle Universität Mathematikunterricht" ist Teil des geplanten umfassenderen Projekts "Virtuelle Universität Neue Medien 21", das sich grundsätzlich auf alle Unterrichtsfächer im allgemeinbildenden Schulwesen beziehen soll (http://vum21.de). Die Neuen Medien sind hierbei nicht nur Unterrichtsmittel, also Medium der durch sie dargestellten Inhalte, sondern sie werden darüber hinaus auch zum Unterrichtsinhalt. Damit wird zugleich das wesentliche Anliegen dessen skizziert, was Integrative Medienpädagogik bedeutet: Die pädagogische Dimension der Neuen Medien in dieser doppelten Rolle, und zwar einerseits bezüglich der zu integrierenden Aspekte Mediendidaktik, Medienkunde und Medienerziehung und andererseits als Bildungsaufgabe für grundsätzlich alle Unterrichtsfächer (in integrativer Zusammenarbeit). Die Entwicklung startet mit Beispielen für den Mathematikunterricht. Hierzu wurden zunächst im letzten Jahr zwei virtuelle Praktika zur öffentlichen Erprobung freigeschaltet: je eines für Bewegliche Geometrie und für Taschencomputer (http://mathematikunterricht.info/VirtKurs/softprakt.htm). Ein weiteres virtuelles Praktikum für Computeralgebrasysteme befindet sich in Entwicklung. Kennzeichnend für das gesamte Projekt ist der Verzicht auf die Verwendung professioneller Lernplattformen. Stattdessen findet die Programmierung nur in HTML unter Einsatz wissenschaftlicher und studentischer Hilfskräfte statt, die darin von der Projektleitung eingewiesen wurden bzw. werden und dann die Projektentwicklung in ihrem Bereich selbstständig durchführen

Acute and Chronic Effects of Smoking on Inflammation Markers in Exhaled Breath Condensate in Current Smokers

Background: Long-term cigarette smoking is associated with pulmonary inflammation, but the acute effects of smoking have been less well studied. Analysis of the exhaled breath condensate (EBC) can provide noninvasive markers that might be indicative of inflammation. Objectives: The aim of the study was to determine whether the pH, electrical conductivity and the levels of ammonium and interleukin 8 (IL-8) of EBC were altered in smokers and whether they changed after smoking a single cigarette. Methods: We included 19 healthy nonsmokers (controls), 29 asymptomatic smokers, 10 patients with stable chronic obstructive pulmonary disease (COPD) {[}Global Initiative for Chronic Obstructive Lung Disease stages (GOLD) stages II-III], and 10 patients with exacerbated COPD. In 13 smokers, EBC was also analyzed before and after smoking. EBC was obtained during 10 min tidal breathing with a cooled RTube (TM). pH was determined after deaeration with argon. Results: Acute smoking did not alter the pH or ammonium and IL-8 levels, but raised conductivity. As in COPD patients, the pH was significantly decreased in chronic smokers with a history of at least 10 pack-years compared to controls. Conclusions: EBC can be used to detect the acute and chronic effects of smoking. The increased conductivity of EBC after smoking suggests acute inflammatory effects. The reduced pH in chronic smokers shows cigarette-induced inflammation. Copyright (C) 2009 S. Karger AG, Base

Desalinization of running waters III. Changes in the structure of diatom assemblages caused by a decreasing salt load and changing ion spectra in the river Wipper (Thuringia, Germany)

AbstractSalt-loaded effluents were introduced into the river Wipper during the mining period for almost a century. Beginning with the year 1990, the waste water load was strongly reduced due to the termination of the potash industry. Prior to 1990, monthly means of the chloride concentrations at times exceeded 6,000 mg l−1 in the strongly polluted sections. Maximum concentrations reached twice these values. Up to 1998, mean annual chloride concentrations decreased to values below 2,000 mg l−1. This led to more balanced fluctuations in salinity which had been pronounced before, depending on discharge and short-term changes in production. Similarly, the physiologically adverse ion conditions improved due to decrasing potassium and increasing calcium proportions.In 1963/64, 1986 and 1998, samples of epilithic, epiphytic and epipsammic diatoms were taken at locations of different salinities along the river and examined for the effects of the salinization on the structure of the diatom assemblages. These structures changed in dependence on salinity. Increasing salt concentrations coincided with decreasing oligohalophilic and increasing mesohalophilic and polyhalophilic species numbers. Above a chloride concentration of about 3,000 mg l−1, the proportion of the latter exceed that of the former (halobion index > 50). Corresponding to different conditions of salinization along the river, characteristic diatom assemblages occur differring from each other and which are specific for the river section. Spring and autumn aspects of the diatom assemblages show also salt-dependent differences. The assemblages found in 1998 after decrease of salinization have changed markedly in comparison to those from 1963/64 and 1986. Halobiontic species predominating formerly occurred only occasionally or not at all. They were replaced by oligohalobic-indifferent forms.An ecological assessment of the changes was performed based on the halobion index calculated from all the samples. For the strongly salinized section of the river Wipper, a shift from α-mesohalobic/polyhalobic conditions in 1963/64 and 1986 to α-oligohalobic/β-mesohalobic conditions in 1998 was found. However, constant α-oligohalobic conditions are still not given. With regard to the transition from α-oligohalobic (limnetic) to β-mesohalobic (brackish) conditions, a maximum chloride concentration of 600 mg l−1 was found. To guarantee α-oligohalobic conditions, a maximum chloride concentration of 400 mg l−1 should not be exceeded

Gene synteny comparisons between different vertebrates provide new insights into breakage and fusion events during mammalian karyotype evolution

<p>Abstract</p> <p>Background</p> <p>Genome comparisons have made possible the reconstruction of the eutherian ancestral karyotype but also have the potential to provide new insights into the evolutionary inter-relationship of the different eutherian orders within the mammalian phylogenetic tree. Such comparisons can additionally reveal (i) the nature of the DNA sequences present within the evolutionary breakpoint regions and (ii) whether or not the evolutionary breakpoints occur randomly across the genome. Gene synteny analysis (E-painting) not only greatly reduces the complexity of comparative genome sequence analysis but also extends its evolutionary reach.</p> <p>Results</p> <p>E-painting was used to compare the genome sequences of six different mammalian species and chicken. A total of 526 evolutionary breakpoint intervals were identified and these were mapped to a median resolution of 120 kb, the highest level of resolution so far obtained. A marked correlation was noted between evolutionary breakpoint frequency and gene density. This correlation was significant not only at the chromosomal level but also sub-chromosomally when comparing genome intervals of lengths as short as 40 kb. Contrary to previous findings, a comparison of evolutionary breakpoint locations with the chromosomal positions of well mapped common fragile sites and cancer-associated breakpoints failed to reveal any evidence for significant co-location. Primate-specific chromosomal rearrangements were however found to occur preferentially in regions containing segmental duplications and copy number variants.</p> <p>Conclusion</p> <p>Specific chromosomal regions appear to be prone to recurring rearrangement in different mammalian lineages ('breakpoint reuse') even if the breakpoints themselves are likely to be non-identical. The putative ancestral eutherian genome, reconstructed on the basis of the synteny analysis of 7 vertebrate genome sequences, not only confirmed the results of previous molecular cytogenetic studies but also increased the definition of the inferred structure of ancestral eutherian chromosomes. For the first time in such an analysis, the opossum was included as an outgroup species. This served to confirm our previous model of the ancestral eutherian genome since all ancestral syntenic segment associations were also noted in this marsupial.</p

Measurement of complex fragments and clues to the entropy production from 42-137-MeV/nucleon Ar + Au

Intermediate-rapidity fragments with A=1-14 emitted from 42-137-MeV/nucleon Ar + Au have been measured. Evidence is presented that these fragments arise from a common moving source. Entropy values are extracted from the mass distributions by use of quantum statistical and Hauser-Feshbach theories. The extracted entropy values of S/A&#8776;2-2.4 are much smaller than the values expected from measured deuteron-to-proton ratios, but are still considerably higher than theoretically predicted values

Light particle spectra from 35 MeV/nucleon 12C-induced reactions on 197Au

Energy spectra for p, d, t, 3He, 4He, and 6He from the reaction 12C+197Au at 35 MeV/nucleon are presented. A common intermediate rapidity source is identified using a moving source fit to the spectra that yields cross sections which are compared to analogous data at other bombarding energies and to several different models. The excitation function of the composite to proton ratios is compared with quantum statistical, hydrodynamic, and thermal models