711 research outputs found
On-board multi-objective mission planning for unmanned aerial vehicles
No full textA system for automated mission planning is presented with a view to operate Unmanned Aerial Vehicles (UAVs) in the National Airspace System (NAS). This paper describes methods for modelling decision variables, for enroute flight planning under Visual Flight Rules (VFR). For demonstration purposes, the task of delivering a medical package to a remote location was chosen. Decision variables include fuel consumption, flight time, wind and weather conditions, terrain elevation, airspace classification and the flight trajectories of other aircraft. The decision variables are transformed, using a Multi-Criteria Decision Making (MCDM) cost function, into a single cost value for a grid-based search algorithm (e.g. A*). It is shown that the proposed system provides a means for fast, autonomous generation of near-optimal flight plans, which in turn are a key enabler in the operation of UAVs in the NAS
Untersuchung der biologischen Aktivität von Nanopartikeln in Tumorschnittkulturen
No full textDie Entdeckung der RNA‐Interferenz (RNA‐i) als ein natürlicher Prozess der Genregulation sorgte auf Grund des möglichen Einsatzes für therapeutische Zwecke für großes Interesse. Probleme beim Transport der RNA‐i‐induzierenden kleinen RNA‐Moleküle (siRNAs) traten vor allem hinsichtlich Ladungsverhältnissen, Instabilität und Molekulargewicht auf. Um diese Probleme zu lösen, wurden zunehmend Transportsysteme aus Nanopartikeln untersucht. Die verwendeten Polyethylenimine (PEIs) sind positiv geladene, verzweigt oder linear aufgebaute Polymere, welche mit RNAs (siRNA, miRNA) Komplexe bilden. Modifikationen der PEI‐Kom‐ plexe können zu einem effektiveren Transport der RNA, zu veränderten pharmakokinetischen Eigenschaften und zu einer verbesserten Biokompatibilität führen. Der Erfolg dieser therapeu‐ tischen Nanopartikel ist insbesondere von der effizienten zellulären Aufnahme, der Fähigkeit der Gewebepenetration und vom Erreichen der Zielzellen abhängig. Der Großteil der bisheri‐ gen Untersuchungen von PEIs wurde an Zellkulturen durchgeführt. Die hier erzielten Ergeb‐ nisse lassen sich jedoch nur schwer auf komplexe in‐vivo‐Systeme übertragen.
Aus diesem Grund wurde in der vorliegenden Arbeit die Anwendung der PEIs an Tumorschnitt‐ kulturen untersucht. Dafür wurde zuerst die Kultivierung von 350 μm durchmessenden Dünn‐ schicht‐Präparaten von Xenotransplantat‐Tumoren aus PC3 und U87 Zelllinien etabliert. Eine erfolgreiche Kultivierung konnte über 14 Tage durchgeführt werden. An bestimmten Zeit‐ punkten nach Kultivierungsbeginn (Tag 1, 3, 5, 7 und 14) wurden die Morphologie und die Vitalität (Apoptose, Proliferation) durch eine HE‐ oder immunhistochemische Färbung be‐ stimmt. Es konnte gezeigt werden, dass die Morphologie der Tumorzellen sowie die Prolifera‐ tion und Apoptose über den gesamten Kultivierungszeitraum erhalten blieben.
Im nächsten Schritt wurde sowohl der Transport der siRNA von nicht‐modifizierten und modi‐ fizierten PEIs als auch der Transport durch deren Lipopolyplex‐Derivate (PEI‐siRNA‐Komplexe mit Liposomenhülle) analysiert. Für die Visualisierung der Komplexe wurde fluoreszenzmar‐ kierte siRNA verwendet. Die PEI‐siRNA‐Komplexe wurden auf die Schnittkulturen gegeben und über 24 Stunden kultiviert. In der mikroskopischen Analyse und ihrer Quantifizierung erfolgte die erste Einschätzung der Gewebepenetration. Es zeigten sich Unterschiede in der Gewebe‐ penetration der verschiedenen Nanopartikel, abhängig von deren Oberflächenladung.
Um die biologische Aktivität der Nanopartikel in lebenden Zellen besser evaluieren zu können, wurde im dritten Schritt der Knockdown eines endogenen Genproduktes untersucht. Zielgen war hier das Onkogen Survivin, welches ein wichtiger endogener Überlebensfaktor der Tu‐ morzellen darstellt. Es gelang der Nachweis eines durch PEI‐siRNA‐Komplexe vermittelten Knockdowns des Survivin‐Gens.
Insgesamt konnten somit Gewebeschnittkulturen als Grundlage für die ex‐vivo Untersuchung von Nanopartikeln etabliert werden. Es konnten nicht nur Aussagen über die Gewebepenet‐ ration der Nanopartikel, sondern auch über ihre biologischen Aktivitäten in einer intakten Ge‐ webestruktur getroffen werden.:Bibliographische Beschreibung 3
1 Einleitung 5
1.1 Der Einsatz der RNA-Interferenz (RNA-i) und von Nanopartikeln in der Medizin 5
1.2 Die RNA-Interferenz 6
1.2.1 Der Prozess der RNA-Interferenz 6
1.2.2 Vor- und Nachteile der RNA-Interferenz 9
1.3 Nanopartikel als Transportsysteme der siRNA: Polyethylenimine 10
1.4 Die Transportfähigkeit von Polyethyleniminen und ihre Optimierung 12
1.5 Anwendung der Polyethylenimine in in-vivo-Systemen 14
1.6 Präklinische Tumormodelle 15
1.6.1 Zellkulturen 15
1.6.2 Xenograft-Modelle und Gewebeschnittkulturen 16
2 Fragestellung 18
3 Literatur 19
4 Publikationen 24
5 Anlagen 32
6 Zusammenfassung und Ausblick 33
7 Erklärung über die eigenständige Abfassung der Arbeit 36
8 Lebenslauf 37
9 Danksagung 40
10 Erklärung über den wissenschaftlichen Beitrag 41
11 Teilnahmebestätigung: Vorlesung zur „Guten Wissenschaftlichen Praxis“ 4
Entwicklung einer schnellen Pulsformanalyse für asymmetrische AGATA-Germanium-Detektoren
No full textOnTEAM metadata: GDSID: DOC-2007-May-32; Attribute ID: LIBRARY-thesis_diss-2007-005; Title: [GSI Diss 2007-05] Entwicklung einer schnellen Pulsformanalyse für asymmetrische AGATA-Germanium-Detektoren; Author(s): Beck, Torsten; Corporate author(s): ; Publication date: 20070501; Creator: manton; Creation date: 15.05.2007 16:02:12; Change date: 29.10.2008 16:29:34; Access: nur berechtigte Gruppen; Attribute type: Text.Thesis.Diss; Directory path: ['GSI Publications', 'GSI as Publisher']; Attribute path: ['Infrastructure', 'Library and Documentation', 'thesis_diss', 'Added in 2007']; File name(s): ['DOC-2007-May-32-1.pdf']; File title(s): ['']; File access: ['nur berechtigte Gruppen'
Manifolds, sheaves, and cohomology
No full textThis book explains techniques that are essential in almost all branches of modern geometry such as algebraic geometry, complex geometry, or non-archimedian geometry. It uses the most accessible case, real and complex manifolds, as a model. The author especially emphasizes the difference between local and global questions. Cohomology theory of sheaves is introduced and its usage is illustrated by many examples. Content Topological Preliminaries - Algebraic Topological Preliminaries - Sheaves - Manifolds - Local Theory of Manifolds - Lie Groups - Torsors and Non-abelian Cech Cohomology - Bundles - Soft Sheaves - Cohomology of Complexes of Sheaves - Cohomology of Sheaves of Locally Constant Functions - Appendix: Basic Topology, The Language of Categories, Basic Algebra, Homological Algebra, Local Analysis Readership Graduate Students in Mathematics / Master of Science in Mathematics About the Author Prof. Dr. Torsten Wedhorn, Department of Mathematics, Technische Universität Darmstadt, Germany
James Watson, Maclyn McCarty, and Torsten Wiesel
No full textTorsten Wiesel (right) with Professor Emeritus Maclyn McCarty (center), co-author of the paper with Oswald Avery and Colin MacLeod, and James D. Watson, director of Cold Spring Harbor Laboratory, 1994
Photo by Leif Carlsson
To commemorate the fiftieth anniversary of the discovery at The Rockefeller University that genes are made of DNA - considered by many to be the single most important biological discovery of the twentieth century - the university has kicked off a year-long series of events that were running through May 1994. The celebration was formally inaugurated in November 1993 with a lecture by Nobel laureate James D. Watson, best known for discovering the double-helical structure of DNA.
See also Search Winter 1994, vol. 4, no. 1https://digitalcommons.rockefeller.edu/group-portraits/1013/thumbnail.jp
Seltsame Schauspiele. Torsten Fogelqvists Deutschlandreise 1934
No full textIn 1934 Torsten Fogelqvist, a prominent member of the Swedish Academy and a well-known journalist and intellectual, visits Nazi Germany. He writes about his visit to the Third Reich in 17 articles published in the Stockholm daily newspaper Dagens Nyheter. The author, highly critical of the Hitler regime, scrutinizes several aspects of the nazified German society such as the attempts to re-educate the German citizen in accordance with the ideology of the new regime, the hero cult in the Nazi movement, and the relationship between the German state and the churches. In order to further an understanding of political and social developments in Germany Fogelqvist uses a specific strategy. He “translates” them into an imaginary Swedish context. This paper compares his views with those of other Swedish visitors
PISM glacial cycle sensitivity experiments of the Antarctic Ice Sheet
No full textThis dataset contains PISM simulation results (http://www.pism-docs.org) of the Antarctic Ice Sheet based on code release v1.0-paleo-ensemble (https://doi.org/10.5281/zenodo.3574033). PISM is the open-source Parallel Ice Sheet Model developed mainly at UAF, USA and PIK, Germany.
With the help of added python scripts, all figures can be reproduced as in the journal publication:
- Albrecht et al., 2020, doi:10.5194/tc-14-599-2020.
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Data:
Find PISM results as netCDF data. See 'README.md' for a list of all performed experiment.
All forcing input data for the experiments and plots can be downloaded and remapped via https://github.com/pism/pism-ais. Some of the original input data files are freely available, for others please contact the author or the corresponding data publisher.
Figure plotting scripts (jupyter notebook based on python, see https://jupyter.org) in 'plot_scripts' access the uploaded PISM results in 'model_data' and save the plots to 'final_figures'. Jupyter notebook can be run in the browser and shared, see https://nbviewer.jupyter.org/url/www.pik-potsdam.de/~albrecht/notebooks/paleo_paper/paleo_paper_final.ipynb.
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Contact:
Albrecht, Torsten ([email protected]) ; Potsdam-Institute for Climate Impact Research (PIK), Potsdam, German
Development of an autonomous helicopter for aerial powerline inspections
No full textAutonomous mini-helicopters have been seen as a viable option for aerial-based powerline inspections, however there are numerous research and engineering challenges in developing a system capable of achieving this task in a dependable manner. We have developed an autonomous helicopter as a research platform which will allow us to demonstrate proof-of-concept capabilities for powerline inspections. Through numerous development cycles and from flight test experience we have gained insights into the key challenges in this area. We discuss these insights, describe the helicopter platform and present our research progress in the area of obstacle avoidance for mini-helicopters
Die Erfolgsfaktoren für unternehmerisches E-Mail-Marketing nach Dr. Torsten Schwarz am Praxisbeispiel ERGOTOPIA GmbH
No full textThis scientific document reveals the results of an empirical examination within the realm of entrepreneurial e-mail-marketing which is based on a literature review by technical author Dr. Torsten Schwarz. Using the start-up company ERGOTOPIA as a practical example, the author of the master thesis investigates whether the explanations of Dr. Schwarz match with the practical implementation of ERGOTOPIA.
Precisely, the scientific paper focuses on the examination of the four aspects lead generation, newsletter-design, software-requirements and performance measurement through monitoring with regard to successful realization of e-mail-marketing campaigns. The empirical part of this examination is made of the introduction as well as the analysis of two conducted so called split-tests that compare specific aspects of the newsletter-design and measure data-driven results to show which kind of aspect produced the more successful campaign.
This way the author proves whether the recommendations by Dr. Schwarz are practically relevant for the company ERGOTOPIA
Invitation to Dialogue - A Progress Report
No full textFragmentation of knowledge and life milieux, so often associated with specialization in science and planning, provided the broad challenge in science and planning, provided the broad challenge for a DIALOGUE PROJECT initiated by Torsten Hägerstrand and Anne Buttimer in Sweden during the Academic Years 1977-1979. The initial incentive for confronting such a wide-ranging set of issues arose from a paper on Values in Geography (Buttimer, 1974), after which the author was invited as a Fulbright lecturer to offer a series of seminars in Lund on problems of knowledge and experience. More than forty participants from ten widely different disciplines took part in this seminar, and foundations were laid for an experientially-grounded approach to the problems of communication across disciplines. The present project was initiated when Anne Buttimer was invited to accept a full time position in Sweden by the Humanistisk-Samhällsvetenskapliga Forskningsrådet (Council for Humanities and Social Science) in 1977. Financial support for this pilot phase of the Dialogue Project was granted by the Swedish Committee for Future Oriented Research and the Bank of Sweden Tercentenary Foundation. The geography department at the University of Lund continues to provide material and administrative help, with Torsten Hägerstrand as Co-Director
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