114 research outputs found
Nachdenken über Biologie – Theorieperspektiven für eine Reflexion von Naturbedeutung und -beziehung
Nachdenken über Biologie – Theorieperspektiven
für eine Reflexion von Naturbedeutung und -beziehun
"Wenn wir keine Blumen hätten ...": empirische Vignetten zum ästhetischen Verhältnis von Kindern zur Natur
Es wird der Frage nachgegangen, welche Rolle die Ästhetik in der kindlichen Naturwahrnehmung spielt. Zunächst wird ein kurzer Überblick über ein Modell der Entwicklung des ästhetischen Urteils und über prominente naturästhetische Positionen gegeben. Beide Zugangsweisen können nicht einfach auf die Naturwahrnehmung von Kindern übertragen werden, weil sich Modelle der ästhetischen Entwicklung nicht auf Natur beziehen und naturästhetische Positionen keine entwicklungsbezogenen Aussagen machen. Ob diese Ansätze auch im Hinblick auf die kindliche Naturwahrnehmung von Bedeutung sind, stellt somit eine empirische Frage dar, die anhand der Interpretation von Kinderaussagen, die in Kindergruppendiskussionen zu naturethischen Dilemmata gewonnen wurden, zu beantworten versucht werden. Die Ergebnisse zeigen, welche Bedeutung die Naturästhetik für Kinder in den Kategorien "Naturschönheit", "Ästhetisierung als Moralisierung", "Natur als Lebensbereicherung" und "Natur als Atmosphäre" hat. Darüber hinaus geben sie Hinweise für die theoretische Weiterführung des Konzepts der Natur als Lebensbereicherung sowie für Fragen nach der Entwicklung des ästhetischen Urteils in Bezug auf Natur.The study presented deals with the question of which role aesthetics play in the child’s perception of nature. Initially we give a brief overview about a model of the development of aesthetic judgment and some prominent theoretical positions of the aesthetics of nature. Both perspectives cannot easily be used for the child's perception of nature because models of aesthetic development do not refer to nature and theoretical positions of the aesthetics of nature do not refer to developmental questions, respectively. Therefore the usefulness of these positions for the child’s perception of nature is an empirical question which we try to answer by interpreting statements from children in group discussions about ethical dilemmas concerning nature. The results show the importance of the aesthetics of nature for the children in the categories "beauty of nature", "aesthetics as a basis for moralizing nature", "nature as enrichment of life" and "nature as atmosphere". Over and above this the results give us some guidelines for the theoretical framework in the area of nature as enrichment of life and for the question of the development of the aesthetic judgment with respect to nature
A New Way of Sensing: Need-Based Activation of Antibiotic Resistance by a Flux-Sensing Mechanism
Sensing of and responding to environmental changes are of vital importance for microbial cells. Consequently, bacteria have evolved a plethora of signaling systems that usually sense biochemical cues either via direct ligand binding, thereby acting as "concentration sensors," or by responding to downstream effects on bacterial physiology, such as structural damage to the cell. Here, we describe a novel, alternative signaling mechanism that effectively implements a " flux sensor" to regulate antibiotic resistance. It relies on a sensory complex consisting of a histidine kinase and an ABC transporter, in which the transporter fulfills the dual role of both the sensor of the antibiotic and the mediator of resistance against it. Combining systems biological modeling with in vivo experimentation, we show that these systems in fact respond to changes in activity of individual resistance transporters rather than to changes in the antibiotic concentration. Our model shows that the cell thereby adjusts the rate of de novo transporter synthesis to precisely the level needed for protection. Such a flux-sensing mechanism may serve as a cost-efficient produce-to-demand strategy, controlling a widely conserved class of antibiotic resistance systems. IMPORTANCE Bacteria have to be able to accurately perceive their environment to allow adaptation to changing conditions. This is usually accomplished by sensing the concentrations of beneficial or harmful substances or by measuring the effect of the prevailing conditions on the cell. Here we show the existence of a new way of sensing the environment, where the bacteria monitor the activity of an antibiotic resistance transporter. Such a "flux-sensing" mechanism allows the cell to detect its current capacity to deal with the antibiotic challenge and thus precisely respond to the need for more transporters. We propose that this is a cost-efficient way of regulating antibiotic resistance on demand
Natur in der Schule
Die Idee des Forschungs- und Entwicklungsprojektes „Natur in der Schule“ fußt sowohl auf den langjährigen naturpädagogischen Erfahrungen der Laborschule Bielefeld und des Oberstufen-Kollegs als auch auf den intensiven Auseinandersetzungen mit dieser Thematik von Ulrich Gebhard und seiner Forschungsgruppe.
Das Projekt hat das Ziel, die Bedeutung von Naturerfahrungen während der Schulzeit zu erforschen. Dabei sind sowohl die Wirkungen auf fachliche und überfachliche Lern- und Bildungsprozesse von Interesse als auch die Rolle von Natur als wichtiger Entwicklungsraum für Kinder und Jugendliche.
Neben diesem zu erforschenden positiven Einfluss von Naturerfahrungen auf Lern-, Bildungs- und Entwicklungsprozesse werden ebenso die wohltuende Wirkung von Natur, der Einfluss auf soziale Beziehungen und Kompetenzen sowie die Bedeutung bzgl. der Ausbildung eines Nachhaltigkeitsbewusstseins in den Blick genommen. Den Ausgangspunkt der schulischen Naturbegegnungen stellen dabei die naturpädagogischen Prinzipien dar, welche auf theoretischen Grundlagen, pädagogischem Erfahrungswissen und empirischen Erkenntnissen basieren. Das Forschungsfeld sind die Bielefelder Versuchsschulen, in denen auch schon vor dem Vorhaben regelmäßige Naturzeiten zum Schulalltag gehörten. Derzeit werden diese hinsichtlich des Erkenntnisinteresses begleitet und beforscht. Die ersten Ergebnisse werden mit Spannung erwartet
Ex Vivo Pulmonary Oedema after In Vivo Blast-Induced Rat Lung Injury: Time Dependency, Blast Intensity and Beta-2 Adrenergic Receptor Role.
Objective: Current treatments for blast-induced lung injury are limited to supportive procedures including mechanical ventilation. The study aimed to investigate the role of post-trauma-induced oedema generation in the function of time and trauma intensity and the probable role of beta 2-adrenergic receptors (β2-ARs) agonists on pulmonary oedema. The study is conducted using an ex vivo model after an experimental in vivo blast-induced thorax trauma in rats. Methods: Rats were randomised and divided into two groups, blast and sham. The blast group were anaesthetised and exposed to the blast wave (3.16 ± 0.43 bar) at a distance of 3.5 cm from the thorax level. The rats were sacrificed 10 min after the blast, the lungs explanted and treated with terbutaline, formoterol, propranolol or amiloride to assess the involvement of sodium transport. Other groups of rats were exposed to distances of 5 and 7 cm from the thorax to reduce the intensity of the injury. Further, one group of rats was studied after 180 min and one after 360 min after a 3.5 cm blast injury. Sham controls were exposed to identical procedures except for receiving blast overpressure. Results: Lung injury and oedema generation depended on time after injury and injury intensity. Perfusion with amiloride resulted in a further increase in oedema formation as indicated by weight gain (p < 0.001), diminished tidal volume (Tv) (p < 0.001), and increased airway resistance (p < 0.001). Formoterol caused a significant increase in the Tv (p < 0.001) and a significant decrease in the airway resistance (p < 0.01), while the lung weight was not influenced. Trauma-related oedema was significantly reduced by terbutaline in terms of lung weight gain (p < 0.01), Tv (p < 0.001), and airway resistance (p < 0.01) compared to control blast-injured lungs. Terbutaline-induced effects were completely blocked by the β-receptor antagonist propranolol (p < 0.05). Similarly, amiloride, which was added to terbutaline perfusion, reversed terbutaline-induced weight gain reduction (p < 0.05). Conclusions: β2-adrenoceptor stimulation had a beneficial impact by amiloride-dependent sodium and therefore, fluid transport mechanisms on the short-term ex vivo oedema generation in a trauma-induced in vivo lung injury of rats
Ex Vivo Pulmonary Oedema after In Vivo Blast-Induced Rat Lung Injury: Time Dependency, Blast Intensity and Beta-2 Adrenergic Receptor Role
Objective: Current treatments for blast-induced lung injury are limited to supportive procedures including mechanical ventilation. The study aimed to investigate the role of post-trauma-induced oedema generation in the function of time and trauma intensity and the probable role of beta 2-adrenergic receptors (β-ARs) agonists on pulmonary oedema. The study is conducted using an ex vivo model after an experimental in vivo blast-induced thorax trauma in rats. Methods: Rats were randomised and divided into two groups, blast and sham. The blast group were anaesthetised and exposed to the blast wave (3.16 ± 0.43 bar) at a distance of 3.5 cm from the thorax level. The rats were sacrificed 10 min after the blast, the lungs explanted and treated with terbutaline, formoterol, propranolol or amiloride to assess the involvement of sodium transport. Other groups of rats were exposed to distances of 5 and 7 cm from the thorax to reduce the intensity of the injury. Further, one group of rats was studied after 180 min and one after 360 min after a 3.5 cm blast injury. Sham controls were exposed to identical procedures except for receiving blast overpressure. Results: Lung injury and oedema generation depended on time after injury and injury intensity. Perfusion with amiloride resulted in a further increase in oedema formation as indicated by weight gain (p < 0.001), diminished tidal volume (Tv) (p < 0.001), and increased airway resistance (p < 0.001). Formoterol caused a significant increase in the Tv (p < 0.001) and a significant decrease in the airway resistance (p < 0.01), while the lung weight was not influenced. Trauma-related oedema was significantly reduced by terbutaline in terms of lung weight gain (p < 0.01), Tv (p < 0.001), and airway resistance (p < 0.01) compared to control blast-injured lungs. Terbutaline-induced effects were completely blocked by the β-receptor antagonist propranolol (p < 0.05). Similarly, amiloride, which was added to terbutaline perfusion, reversed terbutaline-induced weight gain reduction (p < 0.05). Conclusions: β-adrenoceptor stimulation had a beneficial impact by amiloride-dependent sodium and therefore, fluid transport mechanisms on the short-term ex vivo oedema generation in a trauma-induced in vivo lung injury of rats
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Highly resolved observations of trace gases in the lowermost stratosphere and upper troposphere from the Spurt project: an overview
During SPURT (Spurenstofftransport in der Tropopausenregion, trace gas transport in the tropopause region) we performed measurements of a wide range of trace gases with different lifetimes and sink/source characteristics in the northern hemispheric upper troposphere (UT) and lowermost stratosphere (LMS). A large number of in-situ instruments were deployed on board a Learjet 35A, flying at altitudes up to 13.7 km, at times reaching to nearly 380 K potential temperature. Eight measurement campaigns (consisting of a total of 36 flights), distributed over all seasons and typically covering latitudes between 35° N and 75° N in the European longitude sector (10° W–20° E), were performed. Here we present an overview of the project, describing the instrumentation, the encountered meteorological situations during the campaigns and the data set available from SPURT. Measurements were obtained for N2O, CH4, CO, CO2, CFC12, H2, SF6, NO, NOy, O3 and H2O. We illustrate the strength of this new data set by showing mean distributions of the mixing ratios of selected trace gases, using a potential temperature – equivalent latitude coordinate system. The observations reveal that the LMS is most stratospheric in character during spring, with the highest mixing ratios of O3 and NOy and the lowest mixing ratios of N2O and SF6. The lowest mixing ratios of NOy and O3 are observed during autumn, together with the highest mixing ratios of N2O and SF6 indicating a strong tropospheric influence. For H2O, however, the maximum concentrations in the LMS are found during summer, suggesting unique (temperature- and convection-controlled) conditions for this molecule during transport across the tropopause. The SPURT data set is presently the most accurate and complete data set for many trace species in the LMS, and its main value is the simultaneous measurement of a suite of trace gases having different lifetimes and physical-chemical histories. It is thus very well suited for studies of atmospheric transport, for model validation, and for investigations of seasonal changes in the UT/LMS, as demonstrated in accompanying and elsewhere published studies
Highly resolved observations of trace gases in the lowermost stratosphere and upper troposphere from the Spurt project: an overview
During SPURT (Spurenstofftransport in der Tropopausenregion, trace gas transport in the tropopause region) we performed measurements of a wide range of trace gases with different lifetimes and sink/source characteristics in the northern hemispheric upper troposphere (UT) and lowermost stratosphere (LMS). A large number of in-situ instruments were deployed on board a Learjet 35A, flying at altitudes up to 13.7 km, at times reaching to nearly 380 K potential temperature. Eight measurement campaigns (consisting of a total of 36 flights), distributed over all seasons and typically covering latitudes between 35° N and 75° N in the European longitude sector (10° W–20° E), were performed. Here we present an overview of the project, describing the instrumentation, the encountered meteorological situations during the campaigns and the data set available from SPURT. Measurements were obtained for N2O, CH4, CO, CO2, CFC12, H2, SF6, NO, NOy, O3 and H2O. We illustrate the strength of this new data set by showing mean distributions of the mixing ratios of selected trace gases, using a potential temperature – equivalent latitude coordinate system. The observations reveal that the LMS is most stratospheric in character during spring, with the highest mixing ratios of O3 and NOy and the lowest mixing ratios of N2O and SF6. The lowest mixing ratios of NOy and O3 are observed during autumn, together with the highest mixing ratios of N2O and SF6 indicating a strong tropospheric influence. For H2O, however, the maximum concentrations in the LMS are found during summer, suggesting unique (temperature- and convection-controlled) conditions for this molecule during transport across the tropopause. The SPURT data set is presently the most accurate and complete data set for many trace species in the LMS, and its main value is the simultaneous measurement of a suite of trace gases having different lifetimes and physical-chemical histories. It is thus very well suited for studies of atmospheric transport, for model validation, and for investigations of seasonal changes in the UT/LMS, as demonstrated in accompanying and elsewhere published studies
I-BEAT: New ultrasonic method for single bunch measurement of ion energy distribution
The shape of a wave carries all information about the spatial and temporal
structure of its source, given that the medium and its properties are known.
Most modern imaging methods seek to utilize this nature of waves originating
from Huygens' principle. We discuss the retrieval of the complete kinetic
energy distribution from the acoustic trace that is recorded when a short ion
bunch deposits its energy in water. This novel method, which we refer to as
Ion-Bunch Energy Acoustic Tracing (I-BEAT), is a generalization of the
ionoacoustic approach. Featuring compactness, simple operation,
indestructibility and high dynamic ranges in energy and intensity, I-BEAT is a
promising approach to meet the needs of petawatt-class laser-based ion
accelerators. With its capability of completely monitoring a single, focused
proton bunch with prompt readout it, is expected to have particular impact for
experiments and applications using ultrashort ion bunches in high flux regimes.
We demonstrate its functionality using it with two laser-driven ion sources for
quantitative determination of the kinetic energy distribution of single,
focused proton bunches.Comment: Paper: 17 Pages, 3 figures Supplementary Material 16 pages, 7 figure
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