126 research outputs found
Efficiency of shape-adaptive 2-D transforms for coding of arbitrarily shaped image segments
No full textS.254-258We introduce a formula to compute an optimum 2-D shape-adaptive Karhunen-Loeve transform (KLT) suitable for coding pels in arbitrarily-shaped image segments. The efficiency of the KLT on a 2-D AR(1) process is used to benchmark two other shape-adaptive transforms described in literature. It is shown that the optimum KLT significantly outperforms the well known shape-adaptive DCT method introduced by Gilge et al. (1989) for coding Segments of arbitrary shape in intraframe coding mode. A statistical transform gain close to the Gilge-method can be achieved with a shape-adaptive DCT algorithm introduced by Sikora and Makai (see Proc. Workshop Image Anal. Image Coding, Berlin, FRG, Nov. 1993) which is implemented with much lower complexity.5Nr.
Ozone profiles over the Atlantic Ocean between 36 S and 52 N north in March/April 1987 and September/October 1988
No full textVertical ozone soundings were performed during two scientific shipcruises, ANT-V/5 and ANT-VII/1, of the research vessel "Polarstern" over the Atlantic Ocean between 30 °S and 52 °N in March/April 1987 and September/October 1988, respectively. Vertical profiles of ozone and meteorological parameters like pressure, temperature and relative humidity were measured at different latitudes to obtain meridional distributions of tropospheric/lower stratospheric ozone and water vapor during two different seasons. In this volume we will report the results of the individual soundings and the derived meridional distributions of ozone and water vapor measured during the two cruises
Low complexity shape-adaptive DCT for coding of arbitrarily shaped image segments
No full textS.381-95A low complexity shape-adaptive DCT transform algorithm for coding pels in arbitrarily shaped image segments is presented. The proposed algorithm is compared to the well established generalized shape-adaptive transform method introduced by Gilge et al. (1989) in terms of transform efficiency and computational complexity. Results obtained under both theoretical and experimental conditions show that the new algorithm achieves a transform efficiency close to that of the Gilge method with considerably reduced computational complexity. The proposed shape-adaptive DCT algorithm was implemented into a standard MPEG-1 coder to provide object or segment based coding of images and video with additional content-based functionality. The extended MPEG-1 object based coding scheme can handle generic input sequences and can readily provide MPEG-1 backward compatibility if no contour data is transmitted for a given video sequence. Results for INTRA coding of images indicate that the algorithm allows efficient coding over a wide range of coding parameters-thus pro7Nr.4-
Strong daytime production of OH from HNO2 at a rural mountain site
No full textNitrous acid and OH were measured concurrently with a number of other atmospheric components and relevant photolysis frequencies during two campaigns at the Meteorological Observatory Hohenpeissenberg (980ma.s.l.) in summer 2002 and 2004. On most of the 26 measurement days the HNO2 concentration surprisingly showed a broad maximum around noon (on average 100 pptv) and much lower concentrations during the night (similar to 30 pptv). The results indicate a strong unknown daytime source of HNO2 with a production rate on the order of 2-4 x 10(6) cm(-3) s(-1). The data demonstrate an important contribution of HNO2 to local HOx levels over the entire day, comparable with the photolysis of O-3 and HCHO. On average during the 2004 campaign, 42% of integrated photolytic HOx formation is attributable to HNO2 photolysis. Citation: Acker, K., D. Moller, W. Wieprecht, F. X. Meixner, B. Bohn, S. Gilge, C. Plass-Dulmer, and H. Berresheim (2006), Strong daytime production of OH from HNO2 at a rural mountain site, Geophys. Res. Lett., 33, L02809, doi:10.1029/2005GL024643
Die Universität als lernende Organisation?: Eine systemtheoretische Perspektive auf die Leitbildentwicklung
No full textDer anhaltende Misserfolg des politikgetriebenen Reformstakkatos verstärkt seit einer Dekade die Tendenz zu einem Reformmodus, der Universitäten höhere Autonomie zuspricht und auf deren Selbstorganisation gegen die teilweise dramatisch diskutierte Entfremdung von der Gesellschaft setzt. Mit Experimentierklauseln oder gar Hochschulfreiheitsgesetzen wird die Möglichkeit zur Selbstreferenz geschaffen – die Universität ist fortan für sich selbst verantwortlich. Diese Möglichkeit ist gleichwohl nur eine der notwendigen Bedingungen für erfolgreiche Selbstreferenz. Die Fähigkeit dazu liefert die „Entfesselung“ nicht. Dazu muss sich die Universität eingebettet in die sie umfassenden Zusammenhänge begreifen und mögliche Wechselwirkungen zwischen Organisation und Umwelt berücksichtigen können. Diesen voraussetzungsvollen Fall, dass eine Organisation die Auswirkungen ihrer Operationen auf ihre Umwelt sowie daraus entstehende Rückwirkungen auf sich selbst reflektiert, kann mit LUHMANN (1984, S.617) rationale Selbstreflexion genannt werden. Die Arbeit widmet sich dem Managementinstrument der Leitbildentwicklung und untersucht, wie es zur rationalen Selbstreflexion der Universität beitragen kann. Mit der Perspektive der Theorie sozialer Systeme werden drei Bedingungen herausgearbeitet, die im Prozess der Leitbildentwicklung zu berücksichtigen sind, um das orientierende und koordinierende Nutzenpotential dieses Managementinstruments zu entfalten.Due to the persisting failure of ever continuing reforms driven by politics a new mode of reform has been established during the last decade: Universities are granted higher autonomie with respect to decisionmaking aiming at strengthening their capability of self-organisation. With flexible clauses in new higher education laws the possibility for self-reference has been created - Universities are responsible for themselves. This possibility is nevertheless just one of the required conditions for sucessful self-reference. The second required condition, the ability for self-reference, is not fulfilled automatically by just "loosening the chains". In order to develop this ability Universities have to recognize themselves as embedded in a tight network of relationships and they have to be able to incorporate reciprocal effects between themselves and its environment into their decisionmaking. This case of an organisation being able to reflect on its impact on its environment as well as on the backlashes created by that, can be termed "rational reflexivity" with LUHMANN (1984, p.617). This paper adresses the management instrument of creating mission statements and analyses, how this instrument can contribute to the rational reflexivity of Universities. Using the theory of social systems three conditions are suggested that should be accounted for when aiming to unreveal the potential of the orienting and coordinating management instrument mission statements
Die Universität als lernende Organisation?: Eine systemtheoretische Perspektive auf die Leitbildentwicklung
No full textDer anhaltende Misserfolg des politikgetriebenen Reformstakkatos verstärkt seit einer Dekade die Tendenz zu einem Reformmodus, der Universitäten höhere Autonomie zuspricht und auf deren Selbstorganisation gegen die teilweise dramatisch diskutierte Entfremdung von der Gesellschaft setzt. Mit Experimentierklauseln oder gar Hochschulfreiheitsgesetzen wird die Möglichkeit zur Selbstreferenz geschaffen – die Universität ist fortan für sich selbst verantwortlich. Diese Möglichkeit ist gleichwohl nur eine der notwendigen Bedingungen für erfolgreiche Selbstreferenz. Die Fähigkeit dazu liefert die „Entfesselung“ nicht. Dazu muss sich die Universität eingebettet in die sie umfassenden Zusammenhänge begreifen und mögliche Wechselwirkungen zwischen Organisation und Umwelt berücksichtigen können. Diesen voraussetzungsvollen Fall, dass eine Organisation die Auswirkungen ihrer Operationen auf ihre Umwelt sowie daraus entstehende Rückwirkungen auf sich selbst reflektiert, kann mit LUHMANN (1984, S.617) rationale Selbstreflexion genannt werden. Die Arbeit widmet sich dem Managementinstrument der Leitbildentwicklung und untersucht, wie es zur rationalen Selbstreflexion der Universität beitragen kann. Mit der Perspektive der Theorie sozialer Systeme werden drei Bedingungen herausgearbeitet, die im Prozess der Leitbildentwicklung zu berücksichtigen sind, um das orientierende und koordinierende Nutzenpotential dieses Managementinstruments zu entfalten.Due to the persisting failure of ever continuing reforms driven by politics a new mode of reform has been established during the last decade: Universities are granted higher autonomie with respect to decisionmaking aiming at strengthening their capability of self-organisation. With flexible clauses in new higher education laws the possibility for self-reference has been created - Universities are responsible for themselves. This possibility is nevertheless just one of the required conditions for sucessful self-reference. The second required condition, the ability for self-reference, is not fulfilled automatically by just "loosening the chains". In order to develop this ability Universities have to recognize themselves as embedded in a tight network of relationships and they have to be able to incorporate reciprocal effects between themselves and its environment into their decisionmaking. This case of an organisation being able to reflect on its impact on its environment as well as on the backlashes created by that, can be termed "rational reflexivity" with LUHMANN (1984, p.617). This paper adresses the management instrument of creating mission statements and analyses, how this instrument can contribute to the rational reflexivity of Universities. Using the theory of social systems three conditions are suggested that should be accounted for when aiming to unreveal the potential of the orienting and coordinating management instrument mission statements
Die Universität als lernende Organisation?: Eine systemtheoretische Perspektive auf die Leitbildentwicklung
No full textDer anhaltende Misserfolg des politikgetriebenen Reformstakkatos verstärkt seit einer Dekade die Tendenz zu einem Reformmodus, der Universitäten höhere Autonomie zuspricht und auf deren Selbstorganisation gegen die teilweise dramatisch diskutierte Entfremdung von der Gesellschaft setzt. Mit Experimentierklauseln oder gar Hochschulfreiheitsgesetzen wird die Möglichkeit zur Selbstreferenz geschaffen – die Universität ist fortan für sich selbst verantwortlich. Diese Möglichkeit ist gleichwohl nur eine der notwendigen Bedingungen für erfolgreiche Selbstreferenz. Die Fähigkeit dazu liefert die „Entfesselung“ nicht. Dazu muss sich die Universität eingebettet in die sie umfassenden Zusammenhänge begreifen und mögliche Wechselwirkungen zwischen Organisation und Umwelt berücksichtigen können. Diesen voraussetzungsvollen Fall, dass eine Organisation die Auswirkungen ihrer Operationen auf ihre Umwelt sowie daraus entstehende Rückwirkungen auf sich selbst reflektiert, kann mit LUHMANN (1984, S.617) rationale Selbstreflexion genannt werden. Die Arbeit widmet sich dem Managementinstrument der Leitbildentwicklung und untersucht, wie es zur rationalen Selbstreflexion der Universität beitragen kann. Mit der Perspektive der Theorie sozialer Systeme werden drei Bedingungen herausgearbeitet, die im Prozess der Leitbildentwicklung zu berücksichtigen sind, um das orientierende und koordinierende Nutzenpotential dieses Managementinstruments zu entfalten.Due to the persisting failure of ever continuing reforms driven by politics a new mode of reform has been established during the last decade: Universities are granted higher autonomie with respect to decisionmaking aiming at strengthening their capability of self-organisation. With flexible clauses in new higher education laws the possibility for self-reference has been created - Universities are responsible for themselves. This possibility is nevertheless just one of the required conditions for sucessful self-reference. The second required condition, the ability for self-reference, is not fulfilled automatically by just "loosening the chains". In order to develop this ability Universities have to recognize themselves as embedded in a tight network of relationships and they have to be able to incorporate reciprocal effects between themselves and its environment into their decisionmaking. This case of an organisation being able to reflect on its impact on its environment as well as on the backlashes created by that, can be termed "rational reflexivity" with LUHMANN (1984, p.617). This paper adresses the management instrument of creating mission statements and analyses, how this instrument can contribute to the rational reflexivity of Universities. Using the theory of social systems three conditions are suggested that should be accounted for when aiming to unreveal the potential of the orienting and coordinating management instrument mission statements
Protein S-glutathionylation in HEK 293 cells.
No full text<p>(A) The pattern of overall S-glutathionylated proteins is shown in a time course experiment with 0.5 mM diamide or 0.5 mM hydrogen peroxide-treated HEK 293 cells. Equal amount of cell lysates were loaded and separated by a 12% SDS gel under non-reducing condition. S-glutathionylated proteins were detected by Western blot using anti-glutathione monoclonal antibody. Some predominately modified proteins are indicated by arrows. (B) The same amount of lysates from 1(A) were separated in a SDS-gel under reducing condition (50 mM DTT) and the membrane was blotted and stained the same way as in 1(A). The loss of signals indicated the anti-glutathione monoclonal antibody was selectively detecting glutathione moiety on proteins.</p
The effect of oxidant and the non-oxidant alteration of cellular thiol concentration on the formation of protein mixed-disulfides in HEK 293 cells.
No full textCellular molecules possess various mechanisms in responding to oxidant stress. In terms of protein responses, protein S-glutathionylation is a unique post-translational modification of protein reactive cysteines forming disulfides with glutathione molecules. This modification has been proposed to play roles in antioxidant, regulatory and signaling in cells under oxidant stress. Recently, the increased level of protein S-glutathionylation has been linked with the development of diseases. In this report, specific S-glutathionylated proteins were demonstrated in human embryonic kidney 293 cells treated with two different oxidative reagents: diamide and hydrogen peroxide. Diamide is a chemical oxidizing agent whereas hydrogen peroxide is a physiological oxidant. Under the experimental conditions, these two oxidants decreased glutathione concentration without toxicity. S-glutathionylated proteins were detected by immunoblotting and glutathione concentrations were determined by high performance liquid chromatography. We further show the effect of alteration of the cellular thiol pool on the amount of protein S-glutathionylation in oxidant-treated cells. Cellular thiol concentrations were altered either by a specific way using buthionine sulfoximine, a specific inhibitor of glutathione biosynthesis or by a non-specific way, incubating cells in cystine-methionine deficient media. Cells only treated with either buthionine sulfoximine or cystine-methionine deficient media did not induce protein S-glutathionylation, even though both conditions decreased 65% of cellular glutathione. Moreover, the amount of protein S-glutathionylation under both conditions in the presence of oxidants was not altered when compared to the amount observed in regular media with oxidants present. Protein S-glutathionylation is a dynamic reaction which depends on the rate of adding and removing glutathione. Phenylarsine oxide, which specifically forms a covalent adduct with vicinal thiols, was used to determine the possible role of vicinal thiols in the amount of glutathionylation. Our data shows phenylarsine oxide did not change glutathione concentrations, but it did enhance the amount of glutathionylation in oxidant-treated cells
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