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Three-dimensional model study of the arctic ozone loss in 2002/2003 and comparison with 1999/2000 and 2003/2004 (2004)

Wuhu Feng Martyn P. Chipperfield Stewart Davies Bhaswar Sen Geoffrey C. Toon Jean-François Blavier Christopher R. Webster C.-Michael Volk Alexey Ulanovsky Fabrizio Ravegnani Peter von der Gathen Hans-Jürg Jost Erik C. Richard Hans Claude

We have used the SLIMCAT 3-D off-line chemical transport model (CTM) to quantify the Arctic chemical ozone loss in the year 2002/2003 and compare it with similar calculations for the winters 1999/2000 and 2003/2004. Recent changes to the CTM have improved the model's ability to reproduce polar chemical and dynamical processes. The updated CTM uses σ-θ as a vertical coordinate which allows it to extend down to the surface. The CTM has a detailed stratospheric chemistry scheme and now includes a simple NAT-based denitrification scheme in the stratosphere. In the model runs presented here the model was forced by ECMWF ERA40 and operational analyses. The model used 24 levels extending from the surface to ~55 km and a horizontal resolution of either 7.5°×7.5° or 2.8°×2.8°. Two different radiation schemes, MIDRAD and the CCM scheme, were used to diagnose the vertical motion in the stratosphere. Based on tracer observations from balloons and aircraft, the more sophisticated CCM scheme gives a better representation of the vertical transport in this model which includes the troposphere. The higher resolution model generally produces larger chemical O3 depletion, which agrees better with observations. The CTM results show that very early chemical ozone loss occurred in December 2002 due to extremely low temperatures and early chlorine activation in the lower stratosphere. Thus, chemical loss in this winter started earlier than in the other two winters studied here. In 2002/2003 the local polar ozone loss in the lower stratosphere was ~40% before the stratospheric final warming. Larger ozone loss occurred in the cold year 1999/2000 which had a persistently cold and stable vortex during most of the winter. For this winter the current model, at a resolution of 2.8°×2.8°, can reproduce the observed loss of over 70% locally. In the warm and more disturbed winter 2003/2004 the chemical O3 loss was generally much smaller, except above 620 K where large losses occurred due to a period of very low minimum temperatures at these altitudes.

Isolation and X-ray crystal structure of tetrahydroisoquinoline alkaloids from Calycotome villosa Subsp. intermedias (2004)

Ali El Antri Ibtissam Messouri Mohamed Bouktaib Rachid El Alami Michael Bolte Brahim El Bali Mohammed Lachkar

Two tetrahydroisoquinoline alkaloids were extracted from the alkaloid fraction of a methanol extract of the seeds of Calycotome Villosa Subsp. intermedia. Their structures were established as (R)-1-hydroxymethyl-7-8-dimethoxy-1,2,3,4-tetrahydro- isoquinoline (1) and (S)-7-hydroxymethyl-2-3-dimethoxy-7,8,9,10-tetrahydroisoquinoline chloride (2) by spectroscopic techniques and X-ray diffraction analysis.

Models of chronic obstructive pulmonary disease (2004)

Jan David Alexander Groneberg K Fan Chung

Chronic obstructive pulmonary disease (COPD) is a major global health problem and is predicted to become the third most common cause of death by 2020. Apart from the important preventive steps of smoking cessation, there are no other specific treatments for COPD that are as effective in reversing the condition, and therefore there is a need to understand the pathophysiological mechanisms that could lead to new therapeutic strategies. The development of experimental models will help to dissect these mechanisms at the cellular and molecular level. COPD is a disease characterized by progressive airflow obstruction of the peripheral airways, associated with lung inflammation, emphysema and mucus hypersecretion. Different approaches to mimic COPD have been developed but are limited in comparison to models of allergic asthma. COPD models usually do not mimic the major features of human COPD and are commonly based on the induction of COPD-like lesions in the lungs and airways using noxious inhalants such as tobacco smoke, nitrogen dioxide, or sulfur dioxide. Depending on the duration and intensity of exposure, these noxious stimuli induce signs of chronic inflammation and airway remodelling. Emphysema can be achieved by combining such exposure with instillation of tissue-degrading enzymes. Other approaches are based on genetically-targeted mice which develop COPD-like lesions with emphysema, and such mice provide deep insights into pathophysiological mechanisms. Future approaches should aim to mimic irreversible airflow obstruction, associated with cough and sputum production, with the possibility of inducing exacerbations.

Treffen der deutschsprachigen Arachnologen und 3. Mitgliederversammlung der Arachnologischen Gesellschaft e.V. vom 1.-3. Oktober in Bern (CH) (2004)

Angelo Bolzern

Am Naturhistorischen Museum der Burgergemeinde Bern wurde im Herbst 2004 das Treffen der deutschsprachigen Arachnologen durchgeführt. Ein interessantes Programm mit 15 Vorträgen, Postern und einer Filmvorführung bot sich den 39 angemeldeten Teilnehmern.

Kant : autonomia ou estética compromissada? (2004)

Michael Korfmann

A "beleza livre" e a arte não-figurativa (2004)

Luiz Costa Lima

Sublimidad estética y ascetismo burgués : A propósito de la "Analytik des Erhabenen" (2004)

Miguel Vedda

O pétreo : Notas sobre a teoria do sublime a partir do olhar do "mais alheio ao homem" (2004)

Hartmut Böhme

Gewänder als Parerga : Zu Herders "Plastik" (2004)

Natalie Binczek

Der Essay analysiert den Aufsatz über die Plastik von J. G. Herder im Hinblick auf das Verhältnis von Sehen und Fühlen, Außen und Innen, Oberfläche und Körper, Malerei und Skulptur in der ästhetischen Theorie der zweiten Hälfte des 18. Jahrhunderts. Herders Intention ist die Begründung einer autonomen Bildhauerkunst aus der Physiologie des Tastsinnes, der jedoch nicht in Form des Berührens realisiert wird, sondern im visuellen Nachvollzug beim Betrachten der Statue. Charakteristikum der Plastik wäre demzufolge nicht nur die Kompaktheit des Körpers, sondern die damit in ein Spannungsverhältnis tretende Gegliedertheit, das Beiwerk. In dieser Spannung zwischen Haupt- und Beiwerk, Erga und Parerga bilden die Kleider von Statuen an sich einen toten, die Wirkung des "lebenden" Körpers störenden Zusatz. Die "nassen" Gewänder der griechischen Statuen allerdings seien als Parerga gerade so "transparent", dass sie wie eine zweite Haut erscheinen. Parerga dieser Art bilden jedoch keinen überflüssigen, störenden, sondern vielmehr notwendigen Bestandteil der plastischen Kunst, indem sie das organische Innere, das auf den Tod verweist, bedecken, ohne es völlig zu verleugnen.

"Vielleicht Hoffnung" : Noch ein Versuch über Paul Celans Sprachgitter (2004)

Juliana P. Perez

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