250 research outputs found
Rasterionenleitwertmikroskopie
No full textDonnermeyer A. Scanning ion-conductance microscopy. Bielefeld (Germany): Bielefeld University; 2007.In the present work, the development of a combined specialized scanning ion-conductance microscope (SICM) and fluorescence microscope for non-invasive topographical and optical studies on soft samples immersed in electrolyte solution is reported. In SICM, the scanning probe is an electrolyte-filled glass-nanopipette with a tip aperture diameter of about 50 nanometers. Conductivity of an ionic current through the tip, driven by electrodes inside and outside of the pipette, depends on the distance between tip and sample surface (topographical mapping) and on the sample's chemical properties (chemical mapping). For enhancing the sensitivity of the microscope, it is operated in alternating current mode by applying an oscillation to the probe and using a lock-in detection of the modulated current as feedback signal. The presented combination of scanning ion-conductance and fluorescence microscopy demonstrates parallel acquisition of correlated topographical and chemical or optical information. Characterization of the microscope's properties is presented with a detailed analysis of the interaction of all essential elements participating in its operation. Conceptual design and implementation of the control-software that operates on the instrument's specialized real-time hardware is described. Successful employment of the SICM at a resolution beyond the Rayleigh criterion combined with fluorescence-optical studies is presented, demonstrating the manifold capabilities of this instrument for applications in the interacting fields of physics, biology, and chemistry
About the relationship between science and policy. Why a difference exists between the (educational) sience and the trade union of education and science
No full textDer Beitrag ist eine Antwort auf einen vorherigen Artikel von Dieter Wunder, dem ehemaligen Vorsitzenden der Gewerkschaft Erziehung und Wissenschaft (GEW). "In Heft 2/06 hatte Dieter Wunder die Deutung zurückgewiesen, die Achim Leschinsky in der Zeitschrift für Pädagogik für \u27das Scheitern des Deutschen Bildungsrates\u27 formuliert hatte. In seiner Replik erläutert Leschinsky seine Position, dass zwischen Wissenschaft und Politik eine Differenz besteht, die nicht ignoriert werden darf." (DIPF/Orig./So)In number 2/06 of this journal Dieter Wunder rejected the interpretation which Achim Leschinsky (in Zeitschrift für Pädagogik) had formulated concerning the "failure" of the German educational council. In his reply the author explains his position that between science and policy a difference exists which must not be ignored. (DIPF/Orig.
Multicolor single-molecule spectroscopy with alternating laser excitation for the investigation of interactions and dynamics
No full textRoss J, Buschkamp P, Fetting D, Donnermeyer A, Roth CM, Tinnefeld P. Multicolor single-molecule spectroscopy with alternating laser excitation for the investigation of interactions and dynamics. Journal of Physical Chemistry B. 2007;111(2):321-326.We have developed confocal multicolor single-molecule spectroscopy with optimized detection sensitivity on three spectrally distinct channels for the study of biomolecular interactions and FRET between more than two molecules. Using programmable acousto-optical devices as beamsplitter and excitation filter, we overcome some of the limitations of conventional multichroic beamsplitters and implement rapid alternation between three laser lines. This enables to visualize the synthesis of DNA three-way junctions on a single-molecule basis and to resolve seven stoichiometric subpopulations as well as to quantify FRET in the presence of competing energy transfer pathways. Furthermore, the ability to study correlated molecular movements by monitoring several distances within a biomolecular complex simultaneously is demonstrated
Fair Use
No full textZum Ausgleich des Interessenkonfliktes zwischen Urheberrechtsinhaber und Werknutzer haben sich im internationalen Vergleich zwei grundlegend unterschiedliche Regelungstechniken entwickelt. Das eine Modell – dessen prominentester und wirtschaftlich bedeutendster Vertreter die Vereinigten Staaten von Amerika sind – versucht den Interessenausgleich dadurch zu erreichen, dass einem umfassend gewährten Urheberrecht eine ebenso offene Schrankengeneralklausel gegenübergestellt wird. Der zweite, traditionell in den kontinentaleuropäischen Rechtsordnungen vorzufindende und auch in das deutsche Urheberrechtsgesetz übernommene Typus sieht dagegen einen abschließenden Katalog von Einzelausnahmen vor. Achim Förster widmet sich den Rechtssetzungsmöglichkeiten bei der Ausgestaltung urheberrechtlicher Schranken und stellt hierzu die Fair Use-Doktrin des US-amerikanischen Copyright Act (17 U.S.C. § 107) dem Schrankenkatalog des deutschen Urheberrechtsgesetzes (§§ 44a ff. UrhG) gegenüber. Er vergleicht Herkunft, Funktion und Handhabung der Schrankensysteme und untersucht deren Verwurzelung im Verfassungsrecht und in der Urheberrechtstheorie. Aus inter- und supranationaler Sicht stellt er die Frage, welche konkreten Vorgaben sich aus dem Völker- und Europarecht für die Ausgestaltung der nationalen Urheberrechtsschranken ableiten lassen. Der Autor wendet die so gewonnenen Erkenntnisse auf die aktuelle Diskussion zur Flexibilisierung des Schrankenkataloges an und bewertet die rechtspolitischen Optionen des deutschen Gesetzgebers.Addressing the different legislative approaches to copyright limitations, Achim Förster compares the wide scope of the U.S. fair use doctrine (17 U.S.C. § 107) with the German set of explicitly enumerated statutory exceptions. He assesses the major criteria for deciding whether or not certain uses are permitted under U.S. or German copyright law and addresses the question of why these criteria have emerged as a characteristic feature of each system. In addition, the author deals with the influence of international and European law on national copyright legislation and in conclusion makes a contribution to the German discussion on copyright reform
The performance of Bulgarian food markets during reform
No full textFood policy often depends on markets and markets depend on institutions. But how good do institutions have to be before reforms can be launched? Relying on well timed surveys of agricultural prices and a joint study by the Government of Bulgaria and the World Bank on agricultural market institutions, this paper presents evidence that performance in food markets improved following significant policy reforms in Bulgaria, although public institutions remained weak. This suggests that even though strong institutions are preferred to weak ones, it can be costly and impractical to delay policy reforms until work on strengthening institutions is finished. Still, measured performance varied by place and by commodity, suggesting that markets developed at different tempos and that the distribution of benefits from improved markets was uneven. This points to the need to address the costs of adjustment as policies change. The paper introduces a new approach to measure market performance based on composite-error techniques.Markets and Market Access,Transport Economics Policy&Planning,Economic Theory&Research,Access to Markets,Agribusiness
Engineering of cartilage tissue constructs in a 3-dimensional perfusion bioreactor culture system under controlled oxygen tension
No full textThe most relevant results generated in this thesis can be summarized as follow:
· Adult human articular chondrocytes (AHAC) from elderly individuals expanded in culture
medium supplemented with the growth factors TGFβ-1, FGF-2 and PDGF and subsequently
cultured in 3-d pellets had an enhanced chondrogenic capacity when exposed to more
physiological (i.e. 5%) oxygen levels.
· In correlation with the enhanced tissue forming capacity of AHAC from elderly donors under
low oxygen tension, the mRNA expression levels of selective matrix degrading enzymes
were reduced as compared to conventional in vitro oxygen culture condition.
· We developed an integrated bioreactor system, which streamlines within a single device the
phases of perfusion cell seeding and prolonged perfusion culture of cell seeded scaffolds in
vitro.
· The culturing of uniformly seeded adult human articular chondrocytes under direct perfusion,
where cells are continuously exposed to a normoxic range of oxygen levels, can maintain a
uniform distribution of viable cells throughout thick porous scaffolds as compared to
statically cultured constructs.
· The culturing of constructs uniformly seeded with adult human articular chondrocytes under
a more physiological range of oxygen resulted in a higher chondrogenic differentiation as
compared to culture under normoxic levels. Anyhow, this effect was less pronounced as
compared to statically cultured cell constructs or micromass cell pellets, possibly due to the
flow induced shear forces.
· Reduced perfusion flow rates applied to chondrocytes on porous scaffolds significantly
induced more cartilaginous tissue in the presents of low vs. high oxygen levels. However the
effects of low oxygen were not as marked as in pellet culture
Komische Geschichte(n): Der ironische Historismus in Achim von Arnims Roman Die Kronenwaechter
No full textThis thesis presents a new evaluation of Achim von Arnim\u27s principal work by focusing on the role of historical change, irony, the comical and the grotesque as the major constituents of the text. Employing some concepts of Neo-Historicism and poststructural textual analysis, the discourse of the novel is shown in its exchange with the prevailing discourses of the time in the areas of literary criticism, philosophical reflection, natural sciences, and political theory. Discontinuity and disjunction appear as the basic operating mechanisms of a text characterized by an inundating diversity of themes and motifs. The text is seen as open ended in that it refuses to provide the answers to the questions it raises by neither subjecting itself to the triadic philosophical concepts of German Idealism nor proposing any solutions to the political instability of the period depicted in the novel. This reflects the author\u27s uncertainty regarding the historical situation of his own time. The text mechanisms develop from an ironic mode of writing which applies itself as destructive humor exploding into comic particularization. The turn toward the grotesque destroys the desire of the text to create meaning and reveals the specific historicism of Arnim as essentially ironic. The analysis of the interrelatonship between discontinuity of form and plurality of motif patterns is a significant factor to be considered by future thematic studies
Good and Bad Prayers, before Albertus Pictor: Prolegomena to the history of a late medieval image
No full textKeywords: allegory, mural paining, Albertus Pictor, prayer, material culture, crucifixion, church reformSummary:The article represents the first comprehensive examination of the late medieval image of the Good and Bad Prayer, a complex and rare visual allegory of the treasures of Heaven and the treasures of earth (Matthew 6:19–21, 24) created sometime during the first half of the fourteenth century and still in use during the second half of the sixteenth. Focusing on the early history of the image, from its likely inception in a monastic milieu to its wider dissemination by itinerant muralists in Denmark and Sweden during the 1470s – 1490s – the workshop of Albertus Pictor being a chief case in point – the analysis is embedded in a wider discussion of late medieval pictorial didacticism, of attitudes toward materialism and conspicuous consumption, and of the later fourteenth- and fifteenth-centuryculture of lay prayer. A preliminary catalogue of the forty or soknown examples of the Good and Bad Prayer concludes this investigation.CV :Achim Timmermann is Associate Professor at the Department of the History of Art at the University of Michigan, Ann Arbor, where he teaches medieval and northern Renaissance art and architecture. His current research interests include the pictorial and architectural stage- management of the body of Christ, the role of public monuments in medieval civic and rural life, and late medieval allegory. He is author of Real Presence: Sacrament Houses and the Body of Christ, c. 1270–1600 (2009), of the forthcoming monograph Representation and Redemption: Sacred Landscape and the Late Medieval Public Monument, and of over thirty articles on various aspects of medieval and Renaissance visual and architectural culture
Lanelet2 for nuScenes: Map Dataset
No full textLanelet2 maps for the nuScenes dataset, which enable the usage of diverse map-based anchor paths and spatial semantic information. For details see our paper and project page. We also provide a pip package to facilitate the usage.
The maps were generated automatically and subsequently manually refined.
If you use this resource for scientific research, please consider citing
@InProceedings{naumannHertleinLanelet2NuScenes2023,
author = {Naumann, Alexander and Hertlein, Felix and Grimm, Daniel and Zipfl, Maximilian and Thoma, Steffen and Rettinger, Achim and Halilaj, Lavdim and Luettin, Juergen and Schmid, Stefan and Caesar, Holger},
title = {Lanelet2 for nuScenes: Enabling Spatial Semantic Relationships and Diverse Map-Based Anchor Paths},
booktitle = {Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR) Workshops},
month = {June},
year = {2023},
pages = {3247-3256}
ILAS LAGLOBAL Seminar Series: Talking about Objects of Knowledge
No full textLondon : 7 October 2020 17h30-19h30 : Seminar - Venue Online : Professor Miruna Achim (Universidad Autonoma Metropolitana, Mexico City), author of From Idols to Antiquity : Forging the National Museum of Mexico (Nebraska, 2017). Convenor : Professor Mark Thurner (ILAS) Read more : https://ilas.sas.ac.uk/events/event/2281
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