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Sample records for hdr schneller und

  1. Neodadjuvante und adjuvante Kurzzeit-Hormontherapie in Kombination mit konformaler HDR-Brachytherapie beim Prostatakarzinom

    Directory of Open Access Journals (Sweden)

    Martin T

    2004-01-01

    Full Text Available Zielsetzung: Auswertung der Behandlungsergebnisse der neoadjuvanten und adjuvanten Kurzzeit-Hormontherapie kombiniert mit konformaler HDR-Brachytherapie und externer Radiotherapie beim Prostatakarzinom. Patienten und Methoden: Von 01/97 bis 09/99 behandelten wir 102 Patienten mit Prostatakarzinomen im Stadium T1–3 N0 M0. Im Stadium T1–2 befanden sich 71, im Stadium T3 31 Patienten. Der mediane prätherapeutische PSA-Wert betrug 15,3 ng/ml. Nach ultraschallgesteuerter transrektaler Implantation von vier Afterloadingnadeln erfolgte die CT-gestützte 3D-Brachytherapie- Planung. Alle Patienten erhielten vier HDR-Implantate mit einer Referenzdosis von 5 Gy oder 7 Gy pro Implantat. Die Zeit zwischen jedem Implantat betrug jeweils 14 Tage. Nach der Brachytherapie folgte die externe Radiotherapie bis 39,6 Gy oder 45,0 Gy. Alle Patienten erhielten eine neoadjuvante und adjuvante Kurzzeit-Hormontherapie, die 2–19 Monate vor der Brachytherapie eingeleitet und 3 Monate nach Abschluß der externen Radiotherapie abgesetzt wurde (mediane Dauer: 9 Monate. Ergebnisse: Die mediane Nachbeobachtungszeit war 2,6 Jahre (range: 2,0–4,1 Jahre. Die biochemische Kontrollrate betrug 82 % nach 3 Jahren. Bei 14/102 Patienten registrierten wir ein biochemisches Rezidiv, bei 5/102 Patienten ein klinisches Rezidiv. Das Gesamtüberleben betrug 90 %, das krankheitsspezifische Überleben 98,0 % nach 3 Jahren. Ein Patient entwickelte eine prostato-urethro-rektale Fistel als späte Grad 4-Toxizität. Akute Grad-3 Toxizitäten traten bei 4 %, späte Grad-3 Toxizitäten bei 5 % der Patienten auf. Schlußfolgerung: Die neoadjuvante und adjuvante Kurzzeit-Hormontherapie kombiniert mit konformaler HDR-Brachytherapie und externer Radiotherapie erweist sich als sichere und wirksame Behandlungsmodalität beim Prostatakarzinom mit minimalen behandlungsbedingten Toxizitäten und einer vielversprechenden biochemischen Kontrollrate nach medianer Nachbeobachtungszeit von 2,6 Jahren.

  2. Determination of left ventricular heart volume by fast MRI in breath-hold technique: how different are quantitative ventricular angiography, quantitative MRI, and visual echocardiography?; Linksventrikulaere Herzvoluminabestimmung mittels schneller MRT in Atemanhaltetechnik: Wie unterschiedlich sind quantitativer Herzkatheter, quantitativer MRT und visuelle Echokardiographie?

    Energy Technology Data Exchange (ETDEWEB)

    Rominger, M.B.; Bachmann, G.F. [Giessen Univ. (Germany). Diagnostische Radiologie; Kerckhoff-Klinik GmbH, Bad Nauheim (Germany). Projektgruppe Magnetresonanztomographie; Pabst, W. [Giessen Univ. (Germany). Inst. fuer Medizinische Informatik; Ricken, W.W. [Kerckhoff-Klinik GmbH, Bad Nauheim (Germany). Projektgruppe Magnetresonanztomographie; Dinkel, H.P.; Rau, W.S. [Giessen Univ. (Germany). Diagnostische Radiologie

    2000-01-01

    Goal: Comparison of fast MRI, echocardiography (Echo), and ventricular angiography (Cath) in the assessment of left ventricular global function. Methods: Fast MRI in short axis plane, biplane Cath, and 2D Echo were performed in 62 patients [35 coronary artery diseases, 16 acquired valvular diseases (VD), 9 dilated cardiomyopathies (DCM), 1 congenital heart disease and 1 heart transplantation]. Enddiastolic (EDV), endsystolic (ESV), stroke volumes (SV), cardiac output (CO), and ejection fraction (EF) were compared in MRI and Cath. EF was visually estimated in 2D Echo by an experienced observer. Results: In comparison to MRI, Cath overestimated EF by 8.4%, and Echo underestimated EF by 5.6%. The limits of agreement between MRI and Cath in EF were {+-}23.8%, between MRI and Echo {+-}18%, and between Echo and Cath {+-}19.4%. Significant differences were found between Cath and MRI in EDV, SV, and CO, but not for ESV. The best agreement in EF was found in the group with DCM, the worst in the group with VD. Conclusion: Important systemic and random errors were found in the comparison of MRI, Echo, and Cath. For therapy decision and follow-up, the methods should not be exchanged unscrupulously. (orig.) [German] Ziel: Methodenvergleich von schneller Magnetresonanztomographie (MRT), Echokardiographie (Echo) und Herzkatheter (HK) in der Bestimmung linksventrikulaerer globaler Funktionsparameter. Material und Methoden: Bei 62 Patienten (35 koronare Herzerkrankungen, 16 Herzklappenvitien (KV), 9 idiopathische dilatative Kardiomyopathien (DCM), 1 kongenitale Herzerkrankung und 1 Herzktransplantation) wurde ein Methodenvergleich zwischen schneller Cine MRT im Kurzachsenschnitt, biplanarem HK und 2D Echo durchgefuehrt. Verglichen wurden in MRT und HK linksventrikulaeres enddiastolisches (EDV) und endsystolisches Volumen (ESV), Schlagvolumen (SV), Herzzeitvolumen (HZV) und Ejektionsfraktion (EF). In der Echo wurde die EF visuell durch einen erfahrenen Untersucher bestimmt

  3. Observation and simulation of non-laminar flow phenomena at the HDR site near Soulth-sous-forets; Beobachtung und Simulation von nicht-laminarem Fliessverhalten am HDR-Standort Soultz

    Energy Technology Data Exchange (ETDEWEB)

    Kohl, T [ETH Hoenggerberg, Zuerich (Switzerland). Inst. fuer Geophysik; Evans, K F; Hopkirk, R J [Polydynamics Engineering, Maennedorf (Switzerland); Jung, R [Bundesanstalt fuer Geowissenschaften und Rohstoffe, Hannover (Germany); Rybach, L [ETH Hoenggerberg, Zuerich (Switzerland). Inst. fuer Geophysik und Radiometrie

    1997-12-01

    Three independent multi-rate flow experiments were conducted in 1994 and 1995 in the open hole depth interval of a wellbore at the Hot-Dry-Rocks (HDR) test site Soultz. The steady state and transient dowmhole pressure records gave clear indications of non-Darcian flow. A numerical model has been set-up to evaluate these two measurements. An excellent fit of the transient pressure responses of all three flow tests could be achieved by assuming a simple model geometry. The models predict fluid transport along a conduit with substantial surface area in which fully-turbulent flow is occurring. The parameters required by our best-fit simulation all fall into a physically reasonable range. Sensitivity analysis demonstrates a non-Darcian flow regime along highly conductive features. The existence of high capacity far-field faults as postulated in our model confirms earlier characterisations of the Soultz test site. (orig.) [Deutsch] In den Jahren 1994 und 1995 wurden drei unabhaengige Druck- bzw. Fliessratentests in den Bohrungen GPK1 und GPK2 des HDR Standortes Soultz durchgefuehrt. Sowohl die stationaeren wie auch die instationaeren Druckaufzeichnungen gaben bereits klare Hinweise auf nichtlaminare, turbulent-aehnliche Stroemungsverhaeltnisse. Zur genaueren Interpretation dieser Daten wurde das numerische Programm FRACTure erweitert. Unter der Annahme eines geometrisch einfachen Modells konnten die instationaeren Druckantworten sehr gut angepasst werden. Es gelang sogar, die beiden in GPK1 durchgefuehrten Tests durch dieselben Modelle zu erklaeren. Die hierfuer benoetigten Modellparameter liegen in einem physikalisch sinnvollem Rahmen und bestaetigen z.T. fruehere Untersuchungen. Die Existenz grosser Stoerungszonen, welche von den Modellen vorausgesetzt werden, bestaetigt ebenfalls fruehere Charakterisierungen des HDR Standortes Soultz als ein teilweise offenes hydraulisches System. (orig.)

  4. Faster, deeper and safer drilling with tailor-made ``designer tools`` - a new approach in borehole technology; Schneller, weiter und sicherer Bohren mit massgeschneiderten ``Designer Garnituren`` - Ein neuer Ansatz in der Bohrtechnologie

    Energy Technology Data Exchange (ETDEWEB)

    Reich, M. [Technical Services Baker Hughes INTEQ, Celle (Germany)

    1998-12-31

    In the past few years, progress has been made in all deep drilling components, but a systemic approach tends to be neglected. Combinations of optimized components alone will not ensure maximum heading rates, long life and economic efficiency. Since about two years ago, research is being made into ``designer tool combinations``. The contribution describes a typical example along with the software used to select the components. (orig.) [Deutsch] In den vergangenen Jahren sind deutliche Fortschritte bei der Entwicklung aller fuer Tiefbohrungen erforderlicher Komponenten erzielt worden. Vermisst wird aber ein Ansatz zum Systemdenken, da leider haeufig das Zusammenspiel dieser Komponenten im praktischen Einsatz nicht beruecksichtigt wird. Die Kombination optimierter Einzelkomponenten allein fuehrt weder zu maximalem Bohrfortschritt noch zu hoechster Lebensdauer oder einem wirtschaftlichen Optimum. Beste Ergebnisse sind vielmehr von Bohrgarnituren zu erwarten, die nach mechanischen und hydraulischen Gesetzmaessigkeiten fuer eine maximale Leistung des Gesamtsystems zusammengestellt werden. Diese relativ einfache Erkenntnis wird erst seit kurzem systematisch in die Praxis umgesetzt. In den letzten zwei Jahren wurden mehrere umfassende Programme zur Optimierung von Bohrgarnituren durchgefuehrt. Die Ergebnisse, die mit diesen `Designer-Bohrgarnituren` erzielt wurden, demonstrieren in eindrucksvoller Weise das Verbesserungspotential. Nachfolgend werden die typischen Komponenten einer `Designer-Garnitur` beschrieben und ein Einblick in die Software gegeben, die zur Optimierung eingesetzt wird. Die erreichten Verbesserungen gegenueber den zuvor benutzten konventionellen Garnituren werden mit Fallbeispielen belegt. (orig.)

  5. Herausforderungen kleiner und mittlerer Unternehmen

    Science.gov (United States)

    Bergmann, Lars; Crespo, Isabel

    Vielfältige externe Herausforderungen, hervorgerufen durch die Dynamik, mit der sich die wirtschaftliche, technologische, soziokulturelle sowie politische Umwelt wandelt, muss jedes Unternehmen im Laufe der Zeit bestehen (Zäpfel 2000). Diese Herausforderungen werden heute insbesondere durch eine Globalisierung der Wettbewerbssowie Nachfragestrukturen verstärkt. Immer schnellere Prozessund Produktinnovationen, kürzere Produktlebenszyklen und Entwicklungszeiten, eine rasant steigende Variantenvielfalt, Nachfrageschwankungen sowie rasante Entwicklungen der Informations- und Kommunikationstechnologien sind einige der sich schnell verändernden Rahmenbedingungen. Zudem müssen sich Unternehmen an neue Gesetze und rechtliche Rahmenbedingungen anpassen. Im Bereich der Roh- und Einsatzstoffe sind Veränderungen insbesondere durch sich verknappende Rohstoffe und Primärenergieträger und in Folge dessen durch drastische Preissteigerungen für Materialien, Hilfsstoffe, Werkzeuge etc. geprägt.

  6. Europeanization of the Hospital Markets - Opportunities and Risks for German Hospitals (Europaeisierung des Krankenhausmarkets - Chancen und Risiken fuer deutsche Krankenhaeuser)

    Science.gov (United States)

    2004-07-06

    Information Services Institut (3M HIS Institut) hat u.a. mit der Entwicklung eines Werkzeugs zur Pflege und Weiterentwicklung des deutschen DRG-Systems ftir... Pflege (Krankenhauspflege) a. die Kosten wachsen schneller als allgerneine Inflation b. praktisch stabile Krankenversicherungsentnahme c. es existieren 9...Krankenkassen d. die Pflege ist von der Krankenversicherung voll (theoretisch) vergUltet e. Missverhlitnis zwischen Versicherungsentnuhrne und

  7. Der Fliegende Wildretter in Aktion: DLR und BJV nutzen ferngesteuerte Flugplattform zur Rehkitzrettung

    OpenAIRE

    Wimmer, Tilman; Israel, Martin; Haschberger, Peter; Weimann, Anita

    2013-01-01

    Der Fliegende Wildretter des Deutschen Zentrums für Luft- und Raumfahrt ist als prototypische Kleinserie seit dem Jahr 2010 erfolgreich in Deutschland und Österreich im Einsatz, um aus der Luft Wildtiere während der Wiesenmahd aufzuspüren und diese so vor dem Tod durch das Mähwerk zu retten. Der Prototyp basiert auf einem ferngesteuerten Multikopter, der mit mehreren Kameras ausgestattet ist und damit im Flug zuverlässiger und wesentlich schneller Wildtiere erkennen kann, als dies mit bish...

  8. Hydrogen dressings HDR

    International Nuclear Information System (INIS)

    Rosiak, J.M.

    1990-01-01

    Within the past several years new developments in biomaterials have enabled a significant progress in the healing of different kinds of wounds. One of such biomaterials is synthetic hydrogels. They can be formed by means of radiation technology which gives some advantages over chemical methods. Hydrogel dressings HDR have the shape of transparent foil, 3-4 mm thick, which contain over 90% water. They can be used for healing exuding wounds and especially burns, ulcers, bedsores and skin grafts. HDR dressings are sterile, transparent and mechanically resistant

  9. Additional androgen deprivation makes the difference. Biochemical recurrence-free survival in prostate cancer patients after HDR brachytherapy and external beam radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Schiffmann, Jonas; Tennstedt, Pierre; Beyer, Burkhard; Boehm, Katharina; Tilki, Derya; Salomon, Georg; Graefen, Markus [University Medical Center Hamburg-Eppendorf, Martini-Clinic Prostate Cancer Center, Hamburg (Germany); Lesmana, Hans; Platz, Volker; Petersen, Cordula; Kruell, Andreas; Schwarz, Rudolf [University Medical Center Hamburg-Eppendorf, Department of Radiation oncology, Hamburg (Germany)

    2015-04-01

    The role of additional androgen deprivation therapy (ADT) in prostate cancer (PCa) patients treated with combined HDR brachytherapy (HDR-BT) and external beam radiotherapy (EBRT) is still unknown. Consecutive PCa patients classified as D'Amico intermediate and high-risk who underwent HDR-BT and EBRT treatment ± ADT at our institution between January 1999 and February 2009 were assessed. Multivariable Cox regression models predicting biochemical recurrence (BCR) were performed. BCR-free survival was assessed with Kaplan-Meier analyses. Overall, 392 patients were assessable. Of these, 221 (56.4 %) underwent trimodality (HDR-BT and EBRT and ADT) and 171 (43.6 %) bimodality (HDR-BT and EBRT) treatment. Additional ADT administration reduced the risk of BCR (HR: 0.4, 95 % CI: 0.3-0.7, p < 0.001). D'Amico high-risk patients had superior BCR-free survival when additional ADT was administered (log-rank p < 0.001). No significant difference for BCR-free survival was recorded when additional ADT was administered to D'Amico intermediate-risk patients (log-rank p = 0.2). Additional ADT administration improves biochemical control in D'Amico high-risk patients when HDR-BT and EBRT are combined. Physicians should consider the oncological benefit of ADT administration for these patients during the decision-making process. (orig.) [German] Der Nutzen einer zusaetzlichen Hormonentzugstherapie (ADT, ''androgen deprivation therapy'') fuer Patienten mit Prostatakarzinom (PCa), welche mit einer Kombination aus HDR-Brachytherapie (HDR-BT) und perkutaner Bestrahlung (EBRT) behandelt werden, ist weiterhin ungeklaert. Fuer diese Studie wurden konsekutive, nach der D'Amico-Risikoklassifizierung in ''intermediate'' und ''high-risk'' eingeteilte Patienten ausgewaehlt, die zwischen Januar 1999 und Februar 2009 in unserem Institut eine kombinierte Therapie aus HDR-BT, EBRT ± ADT erhalten haben. Eine

  10. HDR Efex Pro After the Shoot

    CERN Document Server

    Sholik, Stan

    2011-01-01

    A concise, on-the-go guide to the new HDR Efex Pro imaging toolkit for photographers Now that you've gone mobile and HDR, you want to be able to download and enhance your favorite photos on the run, without having to return to the mother ship (i.e., your desktop computer). This book shows you just how to do that using the amazing HDR Efex Pro, the image editing toolset from Nik Software. In brilliant color and using plenty of show-stopping examples, this practical guide explains all tools and features. Follow numbered steps and you'll soon be handling things like alignment, ghosting control, h

  11. HDR ühest kaadrist? / Janno Loide

    Index Scriptorium Estoniae

    Loide, Janno

    2008-01-01

    HDR-töötluse (High dynamic range - pildi kõrge dünaamiline ulatus) ja toonide kohandamise (tone mapping) meetodite kasutamisest pildi digitaalsel salvestusel ning sobiva hele-tumeduse leidmisel loodusfotode parema kvaliteedi saamiseks

  12. HDR-Aggregate Read Service (ARS)

    Data.gov (United States)

    Department of Veterans Affairs — ARS is a SOAP web service exposed over HTTPS that provides an aggregated (report) view of HTH Survey, DMP and Census data stored in the HDR DB. ARS is deployed in...

  13. HDR-Clinical Data Service (CDS)

    Data.gov (United States)

    Department of Veterans Affairs — CDS is a SOAP/REST web service interface that supports Create, Retrieve, Update, and Delete (CRUD) operations against HDR data stores over secure Hypertext Transfer...

  14. Von Zetteln und Apparaten. Subjektivierung in bundesdeutschen und britischen Arbeitsämtern der 1970er- und 1980er-Jahre

    Directory of Open Access Journals (Sweden)

    Wiebke Wiede

    2016-11-01

    Full Text Available The article examines the governance of unemployment by employment offices inthe Federal Republic of Germany and the United Kingdom in the 1970s and 1980s, which were times of persisting mass unemployment in both countries, focusing on social meanings encoded into the social space of employment offices. Applying concepts from actor-network theory, the article investigates the agency of things in the administration of unemployment, e.g. folders of files, queue numbers or vacancy notices. In particular, the article considers the mechanisation and increasing use of machines and IT systems in German and British employment offices. With regard to processes of subjectivisation, it investigates how the unemployed experienced things and objects in employment offices. While the newly designed British Jobcentre offered jobs as part of a self-service concept, the German employment offices remained in the bureaucratic tradition whereby the unemployed primarily waited for employment counselling and placement. Der Beitrag untersucht Arbeitsämter in der Bundesrepublik Deutschland und Großbritannien während der 1970er- und 1980er-Jahre, einer Zeit deutlich gestiegener Arbeitslosenzahlen. Im Fokus stehen die Verwaltungsvorgänge, begriffen als soziale Praktiken und Mensch-Ding-Verhältnisse. Mit der Akteur-Netzwerk-Theorie fragt der Aufsatz nach der Agency der Verwaltungsdinge im Arbeitsamt: den Bürogestaltungen, Aktenordnern, Wartenummern oder Stellenaushängen. Problematisiert wird besonders die in den 1970er- und 1980er-Jahren durchgesetzte Technisierung der administrativen Vorgänge, also der vermehrte Einsatz von Apparaten und EDV-Systemen in bundesdeutschen und britischen Arbeitsverwaltungen. In beiden Ländern wurde »Selbstbedienung« zu einem neuen Verhaltensdispositiv, das sich in den neu eingerichteten britischen Jobcentres jedoch schneller durchsetzte als im traditionellen deutschen Arbeitsamt, wo das passive Warten weiterhin eine vorherrschende

  15. Modulare und durchgängige Produktmodelle als Erfolgsfaktor zur Bedienung einer Omni-Channel-Architektur - PLM 4.0

    Science.gov (United States)

    Golovatchev, Julius; Felsmann, Marcus

    Mit der Transformation der Wertschöpfungsstrukturen von Utility 1.0 zu Utility 4.0 erfolgt offensichtlich auch eine Veränderung des Produkts. Vor dem Hintergrund disruptiver Technologien (IoT, Big Data, Cloud, Robotics etc.) und auch gesellschaftlicher Veränderungen entstehen ständig neue Geschäftsmodelle und Produkte, die über die reine Versorgungsdienstleistung (z. B. Strom) hinausgehen. Dabei muss der wertvolle Rohstoff Produktdaten für smarte Produkte durchgängiger und schneller nutzbar gemacht werden. Die modularen und durchgängigen Produktstrukturen leisten einen Beitrag zur Beherrschung von Komplexität und stellen somit einen wesentlichen Hebel für erfolgreiche Produktentwicklung und -management dar. In diesem Beitrag werden Ansätze beschrieben, wie es den vor der Herausforderung Utility 4.0 stehenden Unternehmen gelingen kann, Smart-Energy-Produkte so zu modellieren, dass sie die Interoperabilität der einzelnen Produktionsmodule sicherstellt und ein Ende-zu-Ende-Management ermöglicht.

  16. Exploration of joint systems and major horizontal stress direction in HDR drillholes of the Soultz site (Alsace, France)

    Energy Technology Data Exchange (ETDEWEB)

    Genter, A [BRGM/GIG, Orleans (France); Tenzer, H [Stadtwerke Bad Urach (Germany)

    1997-12-01

    Borehole imaging logs enable continuous recording of natural and artificial planar discontinuities on the drillhole wall and data of the drillhole geometry to be made. Efforts were made to resolve the orientation and characterization of the natural joint system, the active fault pattern, the alteration zones, the orientation of microcracks and the direction of maximum horizontal stress. Intense logging operations and measurements were carried out in the HDR drillholes GPK1 and EPS1 between 1000 and 3600 m depth in the Muschelkalk, Bunter and Granite at Soultz sous Forets. With the help of investigations on subvertical fractures the orientation of the maximum horizontal stress direction was determined as N175 E{+-}17 . These results are consistent with previous investigations performed in the horeholes GPK-1 and EPS-1. (orig./AKF) [Deutsch] Bohrlochmessungen mit dem akustschen Borehole Televiewer und elektrischen Formation MicroScanner (Imager) sowie dem Azimuthal Resistivity Imager und verschiedenen Sonic-Sonden ermoeglichen eine kontinuierliche Aufnahme sowohl von natuerlichen und kuenstlich erzeugten planaren Diskontinuitaeten an der Bohrlochwand als auch der Bohrlochgeometrie. Es wurden die Orientierung und Charakterisierung des natuerlichen Kluftsystems, das aktive Stoerungsmuster, die Alterationszonen, die Orientierung von Mikrorissen und die Orientierung der maximalen horizontalen Hauptspannungsrichtung ermittelt. Die Verfuegbarkeit von Strukturdaten aus Bohrloechern durch Bohrlochmessungen und hydraulischen Testen ermoeglicht die Bestimmung von hydraulisch aktiven Klueften und deren Beziehung zum regionalen Spannungsfeld. Mit Hilfe spezieller Bohrloch-Logs wurden die Orientierung und Haeufigkeit planarer Diskontinuitaeten und ihre scheinbare Oeffnungsweite sowie die Vorzugsrichtung der verschiedenen scheinbaren Weiten bestimmt. Innerhalb des gemeinsamen europaeischen Hot-Dry-Rock-Geothermal-Forschungsprogramms wurden vielfaeltige Bohrlochmessungen in den

  17. Viewpoint adaptive display of HDR images

    DEFF Research Database (Denmark)

    Forchhammer, Søren; Mantel, Claire

    2017-01-01

    In this paper viewpoint adaptive display of HDR images incorporating the effects of ambient light is presented and evaluated. LED backlight displays may render HDR images, but while at a global scale a high dynamic range may be achieved, locally the contrast is limited by the leakage of light...... through the LC elements of the display. To render high quality images, the display with backlight dimming can compute the values of the LED backlight and LC elements based on the input image, information about the viewpoint of the observer(s) and information of the ambient light. The goal is to achieve...... the best perceptual reproduction of the specified target image derived from the HDR input image in the specific viewing situation including multiple viewers, possibly having different preferences. An optimization based approach is presented. Some tests with reproduced images are also evaluated subjectively...

  18. Stripping scattering of fast atoms on surfaces of metal-oxide crystals and ultrathin films; Streifende Streuung schneller Atome an Oberflaechen von Metalloxid-Kristallen und ultraduennen Filmen

    Energy Technology Data Exchange (ETDEWEB)

    Blauth, David

    2010-03-11

    In the framework of the present dissertation the interactions of fast atoms with surfaces of bulk oxides, metals and thin films on metals were studied. The experiments were performed in the regime of grazing incidence of atoms with energies of some keV. The advantage of this scattering geometry is the high surface sensibility and thus the possibility to determine the crystallographic and electronic characteristics of the topmost surface layer. In addition to these experiments, the energy loss and the electron emission induced by scattered projectiles was investigated. The energy for electron emission and exciton excitation on Alumina/NiAl(110) and SiO{sub 2}/Mo(112) are determined. By detection of the number of projectile induced emitted electrons as function of azimuthal angle for the rotation of the target surface, the geometrical structure of atoms forming the topmost layer of different adsorbate films on metal surfaces where determined via ion beam triangulation. (orig.)

  19. What are the costs of an accelerated installation of new onshore wind power and photovoltaic plants?; Was kostet ein schnellerer Ausbau von Wind an Land und Photovoltaik?

    Energy Technology Data Exchange (ETDEWEB)

    Nestle, Uwe [EnKliP Energie- und KlimaPolitik - Beratung, Kiel (Germany)

    2015-01-15

    The most recent amendment of the Renewable Energy Law (EEG), enacted in August 2014, was the first to set limits to the further expansion of renewable energy. However, the continued growth of production capacity from onshore wind and photovoltaic energy would actually only have a low impact on the level of the EEG surcharge. The costs that would be incurred instead through the installation of new natural gas power stations are practically the same. If production capacities from onshore wind and photovoltaic plants grow faster than envisaged by the EEG, it will bring the federal government faster towards its goal of lowering the average remuneration to below 12 cents per kWh.

  20. Evaluation of water-mimicking solid phantom materials for use in HDR and LDR brachytherapy dosimetry

    Science.gov (United States)

    Schoenfeld, Andreas A.; Thieben, Maike; Harder, Dietrich; Poppe, Björn; Chofor, Ndimofor

    2017-12-01

    In modern HDR or LDR brachytherapy with photon emitters, fast checks of the dose profiles generated in water or a water-equivalent phantom have to be available in the interest of patient safety. However, the commercially available brachytherapy photon sources cover a wide range of photon emission spectra, and the range of the in-phantom photon spectrum is further widened by Compton scattering, so that the achievement of water-mimicking properties of such phantoms involves high requirements on their atomic composition. In order to classify the degree of water equivalence of the numerous commercially available solid water-mimicking phantom materials and the energy ranges of their applicability, the radial profiles of the absorbed dose to water, D w, have been calculated using Monte Carlo simulations in these materials and in water phantoms of the same dimensions. This study includes the HDR therapy sources Nucletron Flexisource Co-60 HDR (60Co), Eckert und Ziegler BEBIG GmbH CSM-11 (137Cs), Implant Sciences Corporation HDR Yb-169 Source 4140 (169Yb) as well as the LDR therapy sources IsoRay Inc. Proxcelan CS-1 (131Cs), IsoAid Advantage I-125 IAI-125A (125I), and IsoAid Advantage Pd-103 IAPd-103A (103Pd). Thereby our previous comparison between phantom materials and water surrounding a Varian GammaMed Plus HDR therapy 192Ir source (Schoenfeld et al 2015) has been complemented. Simulations were performed in cylindrical phantoms consisting of either water or the materials RW1, RW3, Solid Water, HE Solid Water, Virtual Water, Plastic Water DT, Plastic Water LR, Original Plastic Water (2015), Plastic Water (1995), Blue Water, polyethylene, polystyrene and PMMA. While for 192Ir, 137Cs and 60Co most phantom materials can be regarded as water equivalent, for 169Yb the materials Plastic Water LR, Plastic Water DT and RW1 appear as water equivalent. For the low-energy sources 106Pd, 131Cs and 125I, only Plastic Water LR can be classified as water equivalent.

  1. Guidelines for optimization of planar HDR implants

    International Nuclear Information System (INIS)

    Zwicker, R.D.; Schmidt-Ullrich, R.

    1996-01-01

    Purpose: Conventional low dose rate (LDR) planar Ir-192 implants are typically carried out using at most a few different source strengths. Remote afterloading offers a much higher degree of flexibility with individually programmable dwell times. Dedicated software is available to generate individual dwell times producing isodose surfaces which contour as closely as possible the target volume. The success of these algorithms in enclosing the target volume while sparing normal tissues is dependent on the positioning of the source guides which constrain the dwell points. In this work we provide source placement guidelines for optimal coverage and dose uniformity in planar high dose rate (HDR) implants. The resulting distributions are compared with LDR treatments in terms of dose uniformity and early and late tissue effects. Materials and methods: Computer studies were undertaken to determine source positions and dwell times for optimal dose uniformity in planar HDR implants, and the results were compared to those obtained using corresponding LDR implant geometries. The improvements in the dose distributions achieved with the remote after loader are expected to help offset the increased late tissue effects which can occur when LDR irradiation is replaced with a few large HDR fractions. Equivalent differential volume-dose (DVD) curves for early and late effects were calculated for different numbers of HDR fractions using a linear-quadratic model and compared to the corresponding curves for the LDR regime. Results: Tables of source placement parameters were generated as guidelines for achieving highly homogeneous planar HDR dose distributions. Differential volume-dose data generated inside the target volume provide a quantitative measure of the improvement in real dose homogeneity obtained with remote afterloading. The net result is a shift of the peak in the DVD curve toward lower doses relative to the LDR implant. The equivalent DVD curves for late effects obtained

  2. Magnetic resonance imaging of pulmonary perfusion. Technical requirements and diagnostic impact; MRT der Lungenperfusion. Technische Voraussetzungen und diagnostischer Stellenwert

    Energy Technology Data Exchange (ETDEWEB)

    Attenberger, U.I.; Buesing, K.; Schoenberg, S.O.; Fink, C. [Klinikum Mannheim der Universitaet Heidelberg, Institut fuer Klinische Radiologie und Nuklearmedizin, Universitaetsmedizin Mannheim, Mannheim (Germany); Ingrisch, M.; Reiser, M. [Klinikum der Ludwig-Maximilians-Universitaet Muenchen, Institut fuer Klinische Radiologie, Campus Grosshadern, Muenchen (Germany)

    2009-08-15

    With technical improvements in gradient hardware and the implementation of innovative k-space sampling techniques, such as parallel imaging, the feasibility of pulmonary perfusion MRI could be demonstrated in several studies. Dynamic contrast-enhanced 3D gradient echo sequences as used for time-resolved MR angiography have been established as the preferred pulse sequences for lung perfusion MRI. With these techniques perfusion of the entire lung can be visualized with a sufficiently high temporal and spatial resolution. In several trials in patients with acute pulmonary embolism, pulmonary hypertension and airway diseases, the clinical benefit and good correlation with perfusion scintigraphy have been demonstrated. The following review article describes the technical prerequisites, current post-processing techniques and the clinical indications for MR pulmonary perfusion imaging using MRI. (orig.) [German] Mit der Verfuegbarkeit leistungsfaehiger Gradientensysteme und schneller k-Raum-Akquisitionstechniken wie der parallelen Bildgebung konnten verschiedene Studien die Machbarkeit der Lungenperfusionsbildgebung in der MRT zeigen. In der Praxis haben sich dynamische kontrastverstaerkte 3D-Gradientenechosequenzen, wie sie fuer zeitaufgeloeste MR-Angiographien verwendet werden, fuer die Bildgebung der Lungenperfusion etabliert. Hiermit ist es moeglich, die Perfusion der gesamten Lunge mit ausreichend hoher zeitlicher und raeumlicher Aufloesung zu visualisieren. In mehren klinischen Studien konnte bei Patienten mit Lungenembolie, pulmonaler Hypertonie sowie Erkrankungen der Atemwege und des Lungenparenchyms der klinische Nutzen der Lungenperfusions-MRT und die gute Uebereinstimmung mit der Lungenperfusionsszintigraphie nachgewiesen werden. Der folgende Uebersichtsartikel beschreibt die technische Durchfuehrung, Bildnachverarbeitung und die klinischen Anwendungsgebiete der MRT zur Untersuchung der Lungenperfusion. (orig.)

  3. A JPEG backward-compatible HDR image compression

    Science.gov (United States)

    Korshunov, Pavel; Ebrahimi, Touradj

    2012-10-01

    High Dynamic Range (HDR) imaging is expected to become one of the technologies that could shape next generation of consumer digital photography. Manufacturers are rolling out cameras and displays capable of capturing and rendering HDR images. The popularity and full public adoption of HDR content is however hindered by the lack of standards in evaluation of quality, file formats, and compression, as well as large legacy base of Low Dynamic Range (LDR) displays that are unable to render HDR. To facilitate wide spread of HDR usage, the backward compatibility of HDR technology with commonly used legacy image storage, rendering, and compression is necessary. Although many tone-mapping algorithms were developed for generating viewable LDR images from HDR content, there is no consensus on which algorithm to use and under which conditions. This paper, via a series of subjective evaluations, demonstrates the dependency of perceived quality of the tone-mapped LDR images on environmental parameters and image content. Based on the results of subjective tests, it proposes to extend JPEG file format, as the most popular image format, in a backward compatible manner to also deal with HDR pictures. To this end, the paper provides an architecture to achieve such backward compatibility with JPEG and demonstrates efficiency of a simple implementation of this framework when compared to the state of the art HDR image compression.

  4. Wirksamkeit und Sicherheit von Fumarsäureestern in Kombination mit Phototherapie bei Patienten mit moderater bis schwerer Plaque-Psoriasis (FAST).

    Science.gov (United States)

    Weisenseel, Peter; Reich, Kristian; Griemberg, Wiebke; Merten, Katharina; Gröschel, Christine; Gomez, Natalie Nunez; Taipale, Kirsi; Bräu, Beate; Zschocke, Ina

    2017-02-01

    Die Behandlung von Psoriasis-Patienten mit einer Kombination aus Fumarsäureestern (FSE, Fumaderm ® ) und Phototherapie (UV) ist verbreitet, wurde aber im Rahmen von Studien wenig untersucht. Bisher liegen lediglich Daten aus einer kleinen Pilotstudie vor. Intention dieser Studie war, eine FSE/UV-Kombinationsbehandlung an einem größeren Patientenkollektiv mit mittelschwerer bis schwerer Psoriasis zu untersuchen. In dieser prospektiven, multizentrischen, nichtinterventionellen Studie wurden Daten von Patienten mit FSE/UV-Kombinationstherapie hinsichtlich der Wirksamkeit (PGA' PASI, DLQI, EQ-5D), Sicherheit und Dosierung über einen Zeitraum von zwölf Monaten erfasst und mit Daten einer retrospektiven Studie mit FSE-Monotherapie verglichen. Es wurden Daten von 363 Patienten ausgewertet. Unter der Kombinationstherapie verbesserten sich alle Wirksamkeitsparameter deutlich. Im Vergleich zur Monotherapie mit FSE konnte durch die Kombination mit UV ein schnellerer Wirkeintritt erzielt werden, wobei nach zwölf Monaten kein Unterschied in der Wirksamkeit bestand. Die Dauer und Art der Phototherapie zeigte keinen Einfluss auf die Wirksamkeitsparameter. Allgemein wurde die Kombinationstherapie gut vertragen. Unerwünschte Ereignisse wurden bei 7 % der Patienten berichtet. Die FSE/UV Kombinationstherapie zeigt eine gute Wirksamkeit und Verträglichkeit und kann zu einem schnelleren Wirkeintritt führen. Eine Kombinationstherapie erscheint vor allem in den ersten drei Monaten der FSE Behandlung sinnvoll. © 2017 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

  5. MO-B-BRC-02: Ultrasound Based Prostate HDR

    International Nuclear Information System (INIS)

    Chang, Z.

    2016-01-01

    Brachytherapy has proven to be an effective treatment option for prostate cancer. Initially, prostate brachytherapy was delivered through permanently implanted low dose rate (LDR) radioactive sources; however, high dose rate (HDR) temporary brachytherapy for prostate cancer is gaining popularity. Needle insertion during prostate brachytherapy is most commonly performed under ultrasound (U/S) guidance; however, treatment planning may be performed utilizing several imaging modalities either in an intra- or post-operative setting. During intra-operative prostate HDR, the needles are imaged during implantation, and planning may be performed in real time. At present, the most common imaging modality utilized for intra-operative prostate HDR is U/S. Alternatively, in the post-operative setting, following needle implantation, patients may be simulated with computed tomography (CT) or magnetic resonance imaging (MRI). Each imaging modality and workflow provides its share of benefits and limitations. Prostate HDR has been adopted in a number of cancer centers across the nation. In this educational session, we will explore the role of U/S, CT, and MRI in HDR prostate brachytherapy. Example workflows and operational details will be shared, and we will discuss how to establish a prostate HDR program in a clinical setting. Learning Objectives: Review prostate HDR techniques based on the imaging modality Discuss the challenges and pitfalls introduced by the three imagebased options for prostate HDR brachytherapy Review the QA process and learn about the development of clinical workflows for these imaging options at different institutions

  6. MO-B-BRC-02: Ultrasound Based Prostate HDR

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Z. [Duke University Medical Center (United States)

    2016-06-15

    Brachytherapy has proven to be an effective treatment option for prostate cancer. Initially, prostate brachytherapy was delivered through permanently implanted low dose rate (LDR) radioactive sources; however, high dose rate (HDR) temporary brachytherapy for prostate cancer is gaining popularity. Needle insertion during prostate brachytherapy is most commonly performed under ultrasound (U/S) guidance; however, treatment planning may be performed utilizing several imaging modalities either in an intra- or post-operative setting. During intra-operative prostate HDR, the needles are imaged during implantation, and planning may be performed in real time. At present, the most common imaging modality utilized for intra-operative prostate HDR is U/S. Alternatively, in the post-operative setting, following needle implantation, patients may be simulated with computed tomography (CT) or magnetic resonance imaging (MRI). Each imaging modality and workflow provides its share of benefits and limitations. Prostate HDR has been adopted in a number of cancer centers across the nation. In this educational session, we will explore the role of U/S, CT, and MRI in HDR prostate brachytherapy. Example workflows and operational details will be shared, and we will discuss how to establish a prostate HDR program in a clinical setting. Learning Objectives: Review prostate HDR techniques based on the imaging modality Discuss the challenges and pitfalls introduced by the three imagebased options for prostate HDR brachytherapy Review the QA process and learn about the development of clinical workflows for these imaging options at different institutions.

  7. MO-B-BRC-04: MRI-Based Prostate HDR

    International Nuclear Information System (INIS)

    Mourtada, F.

    2016-01-01

    Brachytherapy has proven to be an effective treatment option for prostate cancer. Initially, prostate brachytherapy was delivered through permanently implanted low dose rate (LDR) radioactive sources; however, high dose rate (HDR) temporary brachytherapy for prostate cancer is gaining popularity. Needle insertion during prostate brachytherapy is most commonly performed under ultrasound (U/S) guidance; however, treatment planning may be performed utilizing several imaging modalities either in an intra- or post-operative setting. During intra-operative prostate HDR, the needles are imaged during implantation, and planning may be performed in real time. At present, the most common imaging modality utilized for intra-operative prostate HDR is U/S. Alternatively, in the post-operative setting, following needle implantation, patients may be simulated with computed tomography (CT) or magnetic resonance imaging (MRI). Each imaging modality and workflow provides its share of benefits and limitations. Prostate HDR has been adopted in a number of cancer centers across the nation. In this educational session, we will explore the role of U/S, CT, and MRI in HDR prostate brachytherapy. Example workflows and operational details will be shared, and we will discuss how to establish a prostate HDR program in a clinical setting. Learning Objectives: Review prostate HDR techniques based on the imaging modality Discuss the challenges and pitfalls introduced by the three imagebased options for prostate HDR brachytherapy Review the QA process and learn about the development of clinical workflows for these imaging options at different institutions

  8. MO-B-BRC-03: CT-Based Prostate HDR

    International Nuclear Information System (INIS)

    Zoberi, J.

    2016-01-01

    Brachytherapy has proven to be an effective treatment option for prostate cancer. Initially, prostate brachytherapy was delivered through permanently implanted low dose rate (LDR) radioactive sources; however, high dose rate (HDR) temporary brachytherapy for prostate cancer is gaining popularity. Needle insertion during prostate brachytherapy is most commonly performed under ultrasound (U/S) guidance; however, treatment planning may be performed utilizing several imaging modalities either in an intra- or post-operative setting. During intra-operative prostate HDR, the needles are imaged during implantation, and planning may be performed in real time. At present, the most common imaging modality utilized for intra-operative prostate HDR is U/S. Alternatively, in the post-operative setting, following needle implantation, patients may be simulated with computed tomography (CT) or magnetic resonance imaging (MRI). Each imaging modality and workflow provides its share of benefits and limitations. Prostate HDR has been adopted in a number of cancer centers across the nation. In this educational session, we will explore the role of U/S, CT, and MRI in HDR prostate brachytherapy. Example workflows and operational details will be shared, and we will discuss how to establish a prostate HDR program in a clinical setting. Learning Objectives: Review prostate HDR techniques based on the imaging modality Discuss the challenges and pitfalls introduced by the three imagebased options for prostate HDR brachytherapy Review the QA process and learn about the development of clinical workflows for these imaging options at different institutions

  9. MO-B-BRC-04: MRI-Based Prostate HDR

    Energy Technology Data Exchange (ETDEWEB)

    Mourtada, F. [Christiana Care Hospital (United States)

    2016-06-15

    Brachytherapy has proven to be an effective treatment option for prostate cancer. Initially, prostate brachytherapy was delivered through permanently implanted low dose rate (LDR) radioactive sources; however, high dose rate (HDR) temporary brachytherapy for prostate cancer is gaining popularity. Needle insertion during prostate brachytherapy is most commonly performed under ultrasound (U/S) guidance; however, treatment planning may be performed utilizing several imaging modalities either in an intra- or post-operative setting. During intra-operative prostate HDR, the needles are imaged during implantation, and planning may be performed in real time. At present, the most common imaging modality utilized for intra-operative prostate HDR is U/S. Alternatively, in the post-operative setting, following needle implantation, patients may be simulated with computed tomography (CT) or magnetic resonance imaging (MRI). Each imaging modality and workflow provides its share of benefits and limitations. Prostate HDR has been adopted in a number of cancer centers across the nation. In this educational session, we will explore the role of U/S, CT, and MRI in HDR prostate brachytherapy. Example workflows and operational details will be shared, and we will discuss how to establish a prostate HDR program in a clinical setting. Learning Objectives: Review prostate HDR techniques based on the imaging modality Discuss the challenges and pitfalls introduced by the three imagebased options for prostate HDR brachytherapy Review the QA process and learn about the development of clinical workflows for these imaging options at different institutions.

  10. MO-B-BRC-03: CT-Based Prostate HDR

    Energy Technology Data Exchange (ETDEWEB)

    Zoberi, J. [Washington University School of Medicine (United States)

    2016-06-15

    Brachytherapy has proven to be an effective treatment option for prostate cancer. Initially, prostate brachytherapy was delivered through permanently implanted low dose rate (LDR) radioactive sources; however, high dose rate (HDR) temporary brachytherapy for prostate cancer is gaining popularity. Needle insertion during prostate brachytherapy is most commonly performed under ultrasound (U/S) guidance; however, treatment planning may be performed utilizing several imaging modalities either in an intra- or post-operative setting. During intra-operative prostate HDR, the needles are imaged during implantation, and planning may be performed in real time. At present, the most common imaging modality utilized for intra-operative prostate HDR is U/S. Alternatively, in the post-operative setting, following needle implantation, patients may be simulated with computed tomography (CT) or magnetic resonance imaging (MRI). Each imaging modality and workflow provides its share of benefits and limitations. Prostate HDR has been adopted in a number of cancer centers across the nation. In this educational session, we will explore the role of U/S, CT, and MRI in HDR prostate brachytherapy. Example workflows and operational details will be shared, and we will discuss how to establish a prostate HDR program in a clinical setting. Learning Objectives: Review prostate HDR techniques based on the imaging modality Discuss the challenges and pitfalls introduced by the three imagebased options for prostate HDR brachytherapy Review the QA process and learn about the development of clinical workflows for these imaging options at different institutions.

  11. A review of the HDR research programme

    International Nuclear Information System (INIS)

    Talja, H.; Koski, K.; Rintamaa, R.; Keskinen, R.

    1995-10-01

    In the German HDR (Heissdampfreaktor, hot steam reactor) reactor safety programme, experiments and simulating numerical analyses have been undertaken since 1976 to study the integrity and safety of light water reactors under operational and faulted conditions. The last experiments of the programme were conducted in 1991. The post test analyses have been finished by March 1994 and the last final reports were obtained a few months later. The report aims to inform the utilities and the regulatory body of Finland about the contents of the lokset HDR research programme and to consider the applicability of the results to safety analyses of Finnish nuclear power plants. The report centers around the thermal shock and piping component experiments within the last or third phase of the HDR programme. Investigations into severe reactor accidents, fire safety and non-destructive testing, also conducted during the third phase, are not considered. The report presents a review of the following experiment groups: E21 (crack growth under corrosive conditions, loading due to thermal stratification), E22 (leak rate and leak detection experiments of through-cracked piping), E23 (thermal transient and stratification experiments for a pipe nozzle), E31 (vibration of cracked piping due to blow down and closure of isolation valve), E32 (seismically induced vibrations of cracked piping), E33 (condensation phenomena in horizontal piping during emergency cooling). A comprehensive list of reference reports, received by VTT and containing a VTT more detailed description, is given for each experiment group. The review is focused on the loading conditions and their theoretical modelling. A comparison of theoretical and experimental results is presented for each experiment group. The safety margins are finally assessed with special reference to leak-before-break, a well known principle for assuring the integrity of primary circuit piping of nuclear power plants. (orig.) (71 figs., 5 tabs.)

  12. HDR economy with special reference to conditions in Europe

    International Nuclear Information System (INIS)

    Smolka, K.; Kappelmeyer, O.

    1992-01-01

    A cost benefit model for the economic evaluation of HDR energy production cost was developed. It can be used for systematic cost analyses of different components of a HDR plant. This relates to natural subsurface conditions (i.e., geothermal gradient, tectonic stress) as well as technical components (i.e., boreholes, heat/power conversion system). The model provides the limiting conditions for an economic HDR energy production. The economic model was applied for an evaluation of the natural parameters in the subsurface of Germany regarding their HDR-suitability. Within a site selection program in Europe the model is part of feasibility studies for the conceptual design of a HDR demonstration plant at three candidate sites: Bad Urach (Germany); Soultz-sous-Forets (France) and Cornwall (UK)

  13. HDR Image Quality Enhancement Based on Spatially Variant Retinal Response

    Directory of Open Access Journals (Sweden)

    Horiuchi Takahiko

    2010-01-01

    Full Text Available There is a growing demand for being able to display high dynamic range (HDR images on low dynamic range (LDR devices. Tone mapping is a process for enhancing HDR image quality on an LDR device by converting the tonal values of the original image from HDR to LDR. This paper proposes a new tone mapping algorithm for enhancing image quality by deriving a spatially-variant operator for imitating S-potential response in human retina, which efficiently improves local contrasts while conserving good global appearance. The proposed tone mapping operator is studied from a system construction point of view. It is found that the operator is regarded as a natural extension of the Retinex algorithm by adding a global adaptation process to the local adaptation. The feasibility of the proposed algorithm is examined in detail on experiments using standard HDR images and real HDR scene images, comparing with conventional tone mapping algorithms.

  14. Sport und soziale Integration

    OpenAIRE

    Turan, Günes

    2012-01-01

    Sport und soziale Integration : Chancen, Probleme und Perspektiven für Städte und Kommunen ; Tagungsband der gleichnamigen Tagung am 28. und 29. Juni 2011 in Augsburg / Helmut Altenberger ... (Hrsg.). - Hamburg : Feldhaus, Ed. Czwalina, 2012. - 104 S. - (Sportwissenschaft und Sportpraxis ; 161)

  15. Imaging techniques and investigation protocols in pediatric emergency imaging; Aufnahmetechnik und Untersuchungsprotokolle beim paediatrischen Notfall

    Energy Technology Data Exchange (ETDEWEB)

    Scharitzer, M.; Hoermann, M.; Puig, S.; Prokop, M. [Universitaetsklinik fuer Radiodiagnostik, Wien (Austria)

    2002-03-01

    Multislice-CT ermoeglichen eine Verkuerzung der Untersuchungsdauer und eine exaktere Anpassung der Expositionsparameter (Pitchfaktor, mAs-Produkt) mit deutlicher Senkung der Strahlenbelastung. Die MRT wird trotz schneller Sequenzen vorwiegend bei neurologischen und spinalen Notfaellen eingesetzt. Die Aufgabe des Radiologen liegt darin, in Abhaengigkeit von den erwarteten paediatrischen Differenzialdiagnosen die korrekte Untersuchungsmodalitaet zu waehlen und die Untersuchungstechnik individuell anzupassen. (orig.)

  16. Color sensitivity of the multi-exposure HDR imaging process

    Science.gov (United States)

    Lenseigne, Boris; Jacobs, Valéry Ann; Withouck, Martijn; Hanselaer, Peter; Jonker, Pieter P.

    2013-04-01

    Multi-exposure high dynamic range(HDR) imaging builds HDR radiance maps by stitching together different views of a same scene with varying exposures. Practically, this process involves converting raw sensor data into low dynamic range (LDR) images, estimate the camera response curves, and use them in order to recover the irradiance for every pixel. During the export, applying white balance settings and image stitching, which both have an influence on the color balance in the final image. In this paper, we use a calibrated quasi-monochromatic light source, an integrating sphere, and a spectrograph in order to evaluate and compare the average spectral response of the image sensor. We finally draw some conclusion about the color consistency of HDR imaging and the additional steps necessary to use multi-exposure HDR imaging as a tool to measure the physical quantities such as radiance and luminance.

  17. Performance evaluation of objective quality metrics for HDR image compression

    Science.gov (United States)

    Valenzise, Giuseppe; De Simone, Francesca; Lauga, Paul; Dufaux, Frederic

    2014-09-01

    Due to the much larger luminance and contrast characteristics of high dynamic range (HDR) images, well-known objective quality metrics, widely used for the assessment of low dynamic range (LDR) content, cannot be directly applied to HDR images in order to predict their perceptual fidelity. To overcome this limitation, advanced fidelity metrics, such as the HDR-VDP, have been proposed to accurately predict visually significant differences. However, their complex calibration may make them difficult to use in practice. A simpler approach consists in computing arithmetic or structural fidelity metrics, such as PSNR and SSIM, on perceptually encoded luminance values but the performance of quality prediction in this case has not been clearly studied. In this paper, we aim at providing a better comprehension of the limits and the potentialities of this approach, by means of a subjective study. We compare the performance of HDR-VDP to that of PSNR and SSIM computed on perceptually encoded luminance values, when considering compressed HDR images. Our results show that these simpler metrics can be effectively employed to assess image fidelity for applications such as HDR image compression.

  18. HDR video synthesis for vision systems in dynamic scenes

    Science.gov (United States)

    Shopovska, Ivana; Jovanov, Ljubomir; Goossens, Bart; Philips, Wilfried

    2016-09-01

    High dynamic range (HDR) image generation from a number of differently exposed low dynamic range (LDR) images has been extensively explored in the past few decades, and as a result of these efforts a large number of HDR synthesis methods have been proposed. Since HDR images are synthesized by combining well-exposed regions of the input images, one of the main challenges is dealing with camera or object motion. In this paper we propose a method for the synthesis of HDR video from a single camera using multiple, differently exposed video frames, with circularly alternating exposure times. One of the potential applications of the system is in driver assistance systems and autonomous vehicles, involving significant camera and object movement, non- uniform and temporally varying illumination, and the requirement of real-time performance. To achieve these goals simultaneously, we propose a HDR synthesis approach based on weighted averaging of aligned radiance maps. The computational complexity of high-quality optical flow methods for motion compensation is still pro- hibitively high for real-time applications. Instead, we rely on more efficient global projective transformations to solve camera movement, while moving objects are detected by thresholding the differences between the trans- formed and brightness adapted images in the set. To attain temporal consistency of the camera motion in the consecutive HDR frames, the parameters of the perspective transformation are stabilized over time by means of computationally efficient temporal filtering. We evaluated our results on several reference HDR videos, on synthetic scenes, and using 14-bit raw images taken with a standard camera.

  19. Radiotherapy for solitary plasmacytoma and multiple myeloma; Strahlentherapie bei solitaerem Plasmozytom und multiplem Myelom

    Energy Technology Data Exchange (ETDEWEB)

    Schmaus, M.C. [Universitaetsklinikum Heidelberg, Klinik fuer Radioonkologie und Strahlentherapie, Heidelberg (Germany); Neuhof, D. [MVZ Strahlentherapie und Nuklearmedizin Weinheim, Weinheim (Germany)

    2014-06-15

    Solitary plasmacytoma and multiple myeloma require a differentiated radiotherapy. The irradiation for plasmacytoma with an adequate total dose (medullary 40-50 Gy or extramedullary 50-60 Gy) leads to a high degree of local control with a low rate of side effects. In cases of multiple myeloma radiotherapy will achieve effective palliation, both in terms of recalcification as well as reduction of neurological symptoms and analgesia. In terms of analgesia the rule is the higher the single dose fraction the faster the reduction of pain. As part of a conditioning treatment prior to stem cell transplantation radiotherapy contributes to the establishment of a graft versus myeloma effect (GVM). (orig.) [German] Das solitaere Plasmozytom und das multiple Myelom fordern eine differenzierte Strahlenbehandlung. Bei Plasmozytomen fuehrt eine Bestrahlung mit ausreichender Gesamtdosis (medullaer 40-50 Gy oder extramedullaer 50-60 Gy) zu einer hohen Lokalkontrolle mit einer geringen Rate an Nebenwirkungen. Beim multiplen Myelom kann die Strahlentherapie eine effektive Palliation sowohl hinsichtlich Rekalzifikation als auch Reduktion neurologischer Symptomatik und Analgesie erzielen. Hinsichtlich der Analgesie gilt: Je hoeher die Einzeldosis, desto schneller der Wirkeintritt. Im Rahmen einer Konditionierungstherapie vor Stammzelltransplantation traegt die Strahlentherapie zur Etablierung eines Graft-versus-Myelom-Effekts (GvM) bei. (orig.)

  20. Interstitial prostate brachytherapy. LDR-PDR-HDR

    International Nuclear Information System (INIS)

    Kovacs, Gyoergy; Hoskin, Peter

    2013-01-01

    The first comprehensive overview of interstitial brachytherapy for the management of local or locally advanced prostate cancer. Written by an interdisciplinary team who have been responsible for the successful GEC-ESTRO/EAU Teaching Course. Discusses in detail patient selection, the results of different methods, the role of imaging, and medical physics issues. Prostate brachytherapy has been the subject of heated debate among surgeons and the proponents of the various brachytherapy methods. This very first interdisciplinary book on the subject provides a comprehensive overview of innovations in low dose rate (LDR), high dose rate (HDR), and pulsed dose rate (PDR) interstitial brachytherapy for the management of local or locally advanced prostate cancer. In addition to detailed chapters on patient selection and the use of imaging in diagnostics, treatment guidance, and implantation control, background chapters are included on related medical physics issues such as treatment planning and quality assurance. The results obtained with the different treatment options and the difficult task of salvage treatment are fully discussed. All chapters have been written by internationally recognized experts in their fields who for more than a decade have formed the teaching staff responsible for the successful GEC-ESTRO/EAU Prostate Brachytherapy Teaching Course. This book will be invaluable in informing residents and others of the scientific background and potential of modern prostate brachytherapy. It will also prove a useful source of up-to-date information for those who specialize in prostate brachytherapy or intend to start an interstitial brachytherapy service.

  1. TU-C-201-02: Clinical Implementation of HDR: Afterloader and Applicator Selection

    Energy Technology Data Exchange (ETDEWEB)

    Esthappan, J. [Washington University School of Medicine (United States)

    2015-06-15

    Recent use of HDR has increased while planning has become more complex often necessitating 3D image-based planning. While many guidelines for the use of HDR exist, they have not kept pace with the increased complexity of 3D image-based planning. Furthermore, no comprehensive document exists to describe the wide variety of current HDR clinical indications. This educational session aims to summarize existing national and international guidelines for the safe implementation of an HDR program. A summary of HDR afterloaders available on the market and their existing applicators will be provided, with guidance on how to select the best fit for each institution’s needs. Finally, the use of checklists will be discussed as a means to implement a safe and efficient HDR program and as a method by which to verify the quality of an existing HDR program. This session will provide the perspective of expert HDR physicists as well as the perspective of a new HDR user. Learning Objectives: Summarize national and international safety and staffing guidelines for HDR implementation Discuss the process of afterloader and applicator selection for gynecologic, prostate, breast, interstitial, surface treatments Learn about the use of an audit checklist tool to measure of quality control of a new or existing HDR program Describe the evolving use of checklists within an HDR program.

  2. TU-C-201-00: Clinical Implementation of HDR Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2015-06-15

    Recent use of HDR has increased while planning has become more complex often necessitating 3D image-based planning. While many guidelines for the use of HDR exist, they have not kept pace with the increased complexity of 3D image-based planning. Furthermore, no comprehensive document exists to describe the wide variety of current HDR clinical indications. This educational session aims to summarize existing national and international guidelines for the safe implementation of an HDR program. A summary of HDR afterloaders available on the market and their existing applicators will be provided, with guidance on how to select the best fit for each institution’s needs. Finally, the use of checklists will be discussed as a means to implement a safe and efficient HDR program and as a method by which to verify the quality of an existing HDR program. This session will provide the perspective of expert HDR physicists as well as the perspective of a new HDR user. Learning Objectives: Summarize national and international safety and staffing guidelines for HDR implementation Discuss the process of afterloader and applicator selection for gynecologic, prostate, breast, interstitial, surface treatments Learn about the use of an audit checklist tool to measure of quality control of a new or existing HDR program Describe the evolving use of checklists within an HDR program.

  3. Traceable calibration of hospital 192Ir HDR sources

    International Nuclear Information System (INIS)

    Govinda Rajan, K.N.; Sharma, S.D.; Palaniselvam, T.; Vandana, S.; Bhatt, B.C.; Vinatha, S.; Patki, V.S.; Pendse, A.M.; Kannan, V.

    2004-01-01

    A HDR 1000 PLUS well type ionization chamber, procured from Standard Imaging, USA, and maintained by medical Physics and Safety Section (MPSS), Bhabha Atomic Research Centre (BARC), India, as a reference well chamber 1 (RWCH1), was traceably calibrated against the primary standard established by Radiological Standards Laboratory (RSL), BARC for 192 Ir HDR source, in terms of air kerma strength (AKS). An indigenously developed well-type ionization chamber, reference well chamber 2 (RWCH2) and electrometer system, fabricated by CD High Tech (CDHT) Instruments Private Ltd., Bangalore, India, was in turn calibrated against RWCH1. The CDHT system (i.e. RWCH2 and CDHT electrometer system) was taken to several hospitals, in different regions of the country, to check the calibration status of 192 Ir HDR sources. The result of this calibration audit work is reported here. (author)

  4. Evaluating HDR photos using Web 2.0 technology

    Science.gov (United States)

    Qiu, Guoping; Mei, Yujie; Duan, Jiang

    2011-01-01

    High dynamic range (HDR) photography is an emerging technology that has the potential to dramatically enhance the visual quality and realism of digital photos. One of the key technical challenges of HDR photography is displaying HDR photos on conventional devices through tone mapping or dynamic range compression. Although many different tone mapping techniques have been developed in recent years, evaluating tone mapping operators prove to be extremely difficult. Web2.0, social media and crowd-sourcing are emerging Internet technologies which can be harnessed to harvest the brain power of the mass to solve difficult problems in science, engineering and businesses. Paired comparison is used in the scientific study of preferences and attitudes and has been shown to be capable of obtaining an interval-scale ordering of items along a psychometric dimension such as preference or importance. In this paper, we exploit these technologies for evaluating HDR tone mapping algorithms. We have developed a Web2.0 style system that enables Internet users from anywhere to evaluate tone mapped HDR photos at any time. We adopt a simple paired comparison protocol, Internet users are presented a pair of tone mapped images and are simply asked to select the one that they think is better or click a "no difference" button. These user inputs are collected in the web server and analyzed by a rank aggregation algorithm which ranks the tone mapped photos according to the votes they received. We present experimental results which demonstrate that the emerging Internet technologies can be exploited as a new paradigm for evaluating HDR tone mapping algorithms. The advantages of this approach include the potential of collecting large user inputs under a variety of viewing environments rather than limited user participation under controlled laboratory environments thus enabling more robust and reliable quality assessment. We also present data analysis to correlate user generated qualitative

  5. Experience of the first application of HDR brachytherapy in nasopharynx

    International Nuclear Information System (INIS)

    Vega Hernandez, Manuel I.; Alfonso Laguardia, Rodolfo; Silvestre Patallo, Ileana; Roca Muchuli, Carlos; Garcia Heredia, Gilda

    2006-01-01

    A research was made by applying boost on the area of the nasopharynx relapse with high dose rate (HDR) in a diagnosis of nasopharynx carcinoma previously treated with telecobalt therapy, at a dose of 70 Gy. There was persistence of the injury. Three sessions were planned, with consecutive fractions of 6.5 Gy in 15 days, with optimization, using a personal mould of autopolymerizable acrylic. The successful possibility to apply the high rate modern brachytherapy was reaffirmed, as a treatment complementary to teletherapy in case of persistence or relapse. A Micro Selectron HDR equipment was used

  6. Distribution of hydrogen within the HDR-containment under severe accident conditions. OECD standard problem. Final comparison report

    International Nuclear Information System (INIS)

    Karwat, H.

    1992-08-01

    The present report summarizes the results of the International Standard Problem Exercise ISP-29, based on the HDR Hydrogen Distribution Experiment E11.2. Post-test analyses are compared to experimentally measured parameters, well-known to the analysis. This report has been prepared by the Institute for Reactor Dynamics and Reactor Safety of the Technical University Munich under contract with the Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) which received funding for this activity from the German Ministry for Research and Technology (BMFT) under the research contract RS 792. The HDR experiment E11.2 has been performed by the Kernforschungszentrum Karlsruhe (KfK) in the frame of the project 'Projekt HDR-Sicherheitsprogramm' sponsored by the BMFT. Ten institutions from eight countries participated in the post-test analysis exercise which was focussing on the long-lasting gas distribution processes expected inside a PWR containment under severe accident conditions. The gas release experiment was coupled to a long-lasting steam release into the containment typical for an unmitigated small break loss-of-coolant accident. In lieu of pure hydrogen a gas mixture consisting of 15% hydrogen and 85% helium has been applied in order to avoid reaching flammability during the experiment. Of central importance are common overlay plots comparing calculated transients with measurements of the global pressure, the local temperature-, steam- and gas concentration distributions throughout the entire HDR containment. The comparisons indicate relatively large margins between most calculations and the experiment. Having in mind that this exercise was specified as an 'open post-test' analysis of well-known measured data the reasons for discrepancies between measurements and simulations were extensively discussed during a final workshop. It was concluded that analytical shortcomings as well as some uncertainties of experimental boundary conditions may be responsible for deviations

  7. Distribution of hydrogen within the HDR-containment under severe accident conditions. OECD standard problem. Final comparison report

    Energy Technology Data Exchange (ETDEWEB)

    Karwat, H

    1992-08-15

    The present report summarizes the results of the International Standard Problem Exercise ISP-29, based on the HDR Hydrogen Distribution Experiment E11.2. Post-test analyses are compared to experimentally measured parameters, well-known to the analysis. This report has been prepared by the Institute for Reactor Dynamics and Reactor Safety of the Technical University Munich under contract with the Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) which received funding for this activity from the German Ministry for Research and Technology (BMFT) under the research contract RS 792. The HDR experiment E11.2 has been performed by the Kernforschungszentrum Karlsruhe (KfK) in the frame of the project 'Projekt HDR-Sicherheitsprogramm' sponsored by the BMFT. Ten institutions from eight countries participated in the post-test analysis exercise which was focussing on the long-lasting gas distribution processes expected inside a PWR containment under severe accident conditions. The gas release experiment was coupled to a long-lasting steam release into the containment typical for an unmitigated small break loss-of-coolant accident. In lieu of pure hydrogen a gas mixture consisting of 15% hydrogen and 85% helium has been applied in order to avoid reaching flammability during the experiment. Of central importance are common overlay plots comparing calculated transients with measurements of the global pressure, the local temperature-, steam- and gas concentration distributions throughout the entire HDR containment. The comparisons indicate relatively large margins between most calculations and the experiment. Having in mind that this exercise was specified as an 'open post-test' analysis of well-known measured data the reasons for discrepancies between measurements and simulations were extensively discussed during a final workshop. It was concluded that analytical shortcomings as well as some uncertainties of experimental boundary conditions may be responsible for deviations

  8. Formation of vanadium carbide precipitations at the surface of alloys: Thermodynamics and kinetics aspects; Bildung von Vanadiumcarbid-Ausscheidungen auf Legierungsoberflaechen: Thermodynamische und kinetische Aspekte

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, A.; Uebing, C. [Max-Planck-Institut fuer Eisenforschung GmbH, Duesseldorf (Germany)

    1998-12-31

    The paper describes the formation of vanadium carbides on the surface layers of Fe-3%V-C(100) alloys. The phase diagram calculated for this alloyed material using the ThermoCalc program package reveals a co-existence of ferritic matrix and V{sub 3}C{sub 2} at temperatures of T{<=}650 C. This carbide is instable at elevated temperatures, leading to co-existence of ferrite and the cubic VC{sub 1-x}. Experimental analyses revealed the formation of a 2D VC compound in the top layers of the surface of Fe-3%V-C(100) alloys, induced by equilibrium segregation. The paper explains the usefulness of thermodynamic and kinetic calculations for interpretation of precipitation phenomena in steels. Mathematically derived and experimental results of analyses for the case of non-equilibrium segregation showed excellent agreement in the determination of carbide thickness (nanometer scale) and time dependence of segregation under fast cooling conditions. (orig./CB) [Deutsch] In der vorliegenden Arbeit wurde die Bildung von Vanadiumcarbiden auf Fe-3%V-C(100)-Legierungsoberflaechen beschrieben. Das anhand des ThermoCalc-Programmpakets fuer diese Legierungszusammensetzung berechnete Phasendiagramm zeigt bei niedrigen Temperaturen T{<=}650 C die Koexistenz von ferritischer Matrix und V{sub 3}C{sub 2}. Bei hoeheren Temperaturen ist dieses Carbid instabil und es liegt Koexistenz von Ferrit und dem kubischen VC{sub 1-x} vor. Die experimentellen Untersuchungen zeigen die Ausbildung einer zweidimensionalen VC-Oberflaechenverbindung auf Fe-3%V-C(100)-Legierungsoberflaechen durch Gleichgewichtssegregation. Diese Arbeit zeigt, dass thermodynamische und kinetische Rechnungen bei der Deutung von Ausscheidungsphaenomenen in Staehlen sinnvoll eingesetzt werden koennen. Bei der Nichtgleichgewichtssegregation wurde bezueglich Carbiddicke (im Nanometerbereich) und Zeitabhaengigkeit der Ausscheidung bei schneller Abkuehlung eine hervorragende Uebereinstimmung zwischen Simulation und Experiment gefunden

  9. Development of optimized dosimetric models for HDR brachytherapy

    International Nuclear Information System (INIS)

    Thayalan, K.; Jagadeesan, M.

    2003-01-01

    High dose rate brachytherapy (HDRB) systems are in clinical use for more than four decades particularly in cervical cancer. Optimization is the method to produce dose distribution which assures that doses are not compromised at the treatment sites whilst reducing the risk of overdosing critical organs. Hence HDRB optimization begins with the desired dose distribution and requires the calculations of the relative weighting factors for each dwell position with out changing the source activity. The optimization for Ca. uterine cervix treatment is simply duplication of the dose distribution used for Low dose rate (LDR) applications. In the present work, two optimized dosimetric models were proposed and studied thoroughly, to suit the local clinical conditions. These models are named as HDR-C and HDR-D, where C and D represent configuration and distance respectively. These models duplicate exactly the LDR pear shaped dose distribution, which is a golden standard. The validity of these models is tested in different clinical situations and in actual patients (n=92). These models: HDR-C and HDR-D reduce bladder dose by 11.11% and 10% and rectal dose by 8% and 7% respectively. The treatment time is also reduced by 12-14%. In a busy hospital setup, these models find a place to cater large number of patients, while addressing individual patients geometry. (author)

  10. Coexistence Mechanism for Colocated HDR/LDR WPANs Air Interfaces

    Directory of Open Access Journals (Sweden)

    Prasad Ramjee

    2010-01-01

    Full Text Available This paper addresses the issues of interference management among Low Data Rate (LDR and High Data Rate (HDR WPAN air interfaces that are located in close-proximity (up to 10 cm and eventually on the same multimode device. After showing the noticeable performance degradation in terms of Bit Error Rate (BER and goodput due to the out-of-band interference of an HDR air interface over an LDR air interface, the paper presents a novel coexistence mechanism, named Alternating Wireless Activity (AWA, which is shown to greatly improve the performance in terms of goodput of the most interference vulnerable air interface (i.e., the LDR air interface. The main difference of the proposed mechanism with respect to other collaborative mechanisms based on time-scheduling is that it synchronizes the transmission of the LDR and HDR WPANs at the superframe level instead of packet level. Advantages and limitations of this choice are presented in the paper. Furthermore the functionalities of the AWA mechanism are positioned in a common protocol layer over the Medium Access Control (MAC sublayers of the HDR and LDR devices and it can be used with any standard whose MAC is based on a superframe structure.

  11. Radiobiological considerations in gynaecological HDR and LDR brachytherapy

    International Nuclear Information System (INIS)

    Bauer, M.; Schulz-Wendtland, R.

    1989-01-01

    In brachytherapy the advantages of high dose rate over low dose rate afterloading therapy were obvious. Out-patient treatment becomes possible, the position of the sources is reproducible and can be observed during the treatment and the patients have to be immobilised for only a short time, giving less psychological stress and a decreased risk of thrombosis and embolism. When changing from LDR to HDR afterloading therapy we are not yet able to evaluate its biological impact. Radiobiological considerations and our experimental data, however, give us the following clinical consequences by using HDR brachytherapy: There is a need for about 15 fractions or more and each increase in dose rate requires higher fractioning. Due to the steep dose rate decline and the inhomogeneous dose distribution, multiple equivalence factors are necessary when fractioning is not sufficiently high. Correction factors to reduce the dose close to the source are low, with increasing distance from the source they increase. If HDR radiation therapy is used, the percutaneous dose in the pelvic wall region should be reduced. The reduction of the dose in HDR brachytherapy is a compromise to limit the side effects caused by the radiation. The drawback is a small therapeutic range and reduced therapeutic effectivity at the tumour. (orig.) [de

  12. Digitalisierung und Selbstbestimmung

    Directory of Open Access Journals (Sweden)

    Bezemek, Christoph

    2017-12-01

    Full Text Available Der vorliegende Beitrag skizziert das Zusammenspiel von Digitalisierung und individueller Selbstbestimmung, stellt die Frage, welche Herausforderungen dieses Zusammenspiel birgt und diskutiert, wie ihnen begegnet werden kann.

  13. Emotion, Motivation und Volition

    OpenAIRE

    Ulich, Dieter

    1996-01-01

    Emotion, Motivation und Volition / D. Ulich ; V. Brandstätter ; P. M. Gollwitzer. - In: Psychologie / hrsg. von Dietrich Dörner ... - 2., überarb. und erw. Aufl. - Stuttgart u.a. : Kohlhammer, 1996. - S. 115-135

  14. Informationskompetenz und Information Literacy

    OpenAIRE

    Ingold, Marianne

    2012-01-01

    Informationskompetenz ist heute als Begriff , Konzept und praktisches Tätigkeitsfeld von Bibliotheken weltweit etabliert. Entstehung, Verbreitung und Entwicklung von „Informationskompetenz“ im deutschsprachigen Raum stehen in engem Zusammenhang mit dem in den USA und international seit den 1980er Jahren diskutierten und praktisch umgesetzten Konzept der „Information Literacy“. Auch wenn die beiden Begriffe in der Regel gleichbedeutend verwendet werden, zeigt ein Vergleich der vorwiegend aus e...

  15. Breeder development and breeder strategies worldwide; Brueterentwicklung und Brueterstrategien weltweit

    Energy Technology Data Exchange (ETDEWEB)

    Marth, W. [Stabsabteilung Finanzen/Controlling, Bereich Stillegung Nuklearer Anlagen, Forschungszentrum Karlsruhe GmbH (Germany)

    1997-05-01

    Fast breeders are currently operated in six countries. In addition, a breeder power plant is under construction in China. The largest plant in operation is the 1250 MWe Superphenix in France. After considerable commissioning problems, it has meanwhile attained a good availability. However, its operating license was revoked on legal grounds; one of the main reasons for that decision was the absence of a public inquiry. The operation of several fast breeders in Russia and Kazakhstan has been almost entirely devoid of problems for years. In contrast, the situation in Japan is somewhat confused at the moment, as the Japanese prototype breeder, MONJU, suffered a sodium leakage accident in 1995 and has since been down. The Indian FBTR experimental breeder is troubled by many technical problems in its commissioning phase. The American FFTR fast reactor has been kept in a hot, but non-nuclear, state for years because the politicians cannot agree on its destiny. The fate of the German SNR-300 prototype breeder is well known: For six years, no operating permit was granted to the Kalkar Nuclear Power Station. After the plant had been decommissioned in 1991 for political reasons, it was dismantled in part and has recently been converted into a fun park. (orig.) [Deutsch] In sechs Laendern werden derzeit Schnelle Brueter betrieben; in China ist darueber hinaus ein Brueterkraftwerk im Bau. Die groesste betriebene Anlage ist der 1250-MWe-Superphenix in Frankreich. Nach betraechtlichen Inbetriebsnahmeproblemen hat er inzwischen eine gute Verfuegbarkeit erreicht; aus juristischen Gruenden wurde im jedoch die Betriebsgenehmigung entzogen, wobei das Fehlen einer oeffentlichen Anhoerung die wesentliche Rolle spielt. Ziemlich problemlos ist seit Jahren der Betrieb mehrerer Schneller Brueter in Russland und Kasachstan. Demgegenueber ist die Situation in Japan derzeit etwas verworren: Der dortige Prototyp Monju erlitt 1995 einen Natriumleckagestoerfall und ist seitdem abgeschaltet. Der

  16. Romanistik und gender studies

    Directory of Open Access Journals (Sweden)

    Susanne Schlünder

    2000-11-01

    Full Text Available Die beiden Bände bieten ein breites Spektrum von Beiträgen zur französischen, italienischen und spanischen Literaturwissenschaft. Gedankliche Grundlage der im einzelnen unterschiedlichen Ansätze und Zielsetzungen ist ein im Anschluß an Judith Butler gender-reflektierendes, diskursives Konzept von Geschlecht, dessen wissenschaftsgeschichtliche Herleitung und Perspektiven Renate Kroll einleitend darlegt. Die einzelnen Artikel beschäftigen sich zum einen mit literarischen Strategien, die Schriftstellerinnen vom Mittelalter bis zur Gegenwart erprobt haben, und hinterfragen dabei die Rolle weiblicher Autoren in Literaturgeschichte und Literaturgeschichtsschreibung. Zum anderen widmen sie sich den literarischen Inszenierungs- und Repräsentationsformen von Weiblichkeit und stellen darüber einen Bezug zur Lebenswelt der behandelten Autorinnen her.

  17. In a hurdle race to the energy transition. From transformations, reforms and innovations; Im Huerdenlauf zur Energiewende. Von Transformationen, Reformen und Innovationen

    Energy Technology Data Exchange (ETDEWEB)

    Brunnengraeber, Achim; Di Nucci, Maria Rosaria (eds.) [Freie Univ. Berlin (Germany)

    2014-07-01

    The term of the energy transition will not be translated as it travels around the world. He points to the urgency of the conversion of the energy supply for electricity, heat and mobility through renewable energies. Faster than many had expected the energy revolution has reached a pace of expansion, especially in the electricity sector, which many did not expect. However, it is not a voluntary measure, but is forced by the proneness of unsustainable production methods and lifestyles. It is also not a foregone conclusion. The many new initiatives, policies and programs are in competition with an old, fossil and nuclear energy system. From the hurdles that have already been taken in this race, the pace of expansion, innovation as well as the necessary reforms and diverse challenges of the energy transition, this book is dealing. [German] Der Begriff der Energiewende wird bei seinem Lauf um die Welt nicht uebersetzt. Er weist auf die Dringlichkeit der Umstellung der Energieversorgung bei Strom, Waerme und Mobilitaet durch erneuerbare Energien hin. Schneller als von vielen erwartet hat die Energiewende vor allem im Strombereich ein Ausbautempo erreicht, mit dem viele nicht gerechnet hatten. Sie ist allerdings keine freiwillige Massnahme, sondern wird durch die Krisenhaftigkeit von nicht nachhaltigen Produktions- und Lebensweisen erzwungen. Sie ist auch kein Selbstlaeufer. Die vielfaeltigen neuen Initiativen, Massnahmen und Programme befinden sich im Wettbewerb mit einem alten, fossilen und nuklearen Energiesystem. Von den Huerden, die in diesem Wettlauf bereits genommen wurden, vom Tempo des Ausbaus, von Innovationen sowie von den notwendigen Reformen und vielfaeltigen Herausforderungen der Energiewende handelt dieses Buch.

  18. Occurrence Prospect of HDR and Target Site Selection Study in Southeastern of China

    Science.gov (United States)

    Lin, W.; Gan, H.

    2017-12-01

    Hot dry rock (HDR) geothermal resource is one of the most important clean energy in future. Site selection a HDR resource is a fundamental work to explore the HDR resources. This paper compiled all the HDR development projects domestic and abroad, and summarized the location of HDR geothermal geological index. After comparing the geological background of HDR in the southeast coastal area of China, Yangjiang Xinzhou in Guangdong province, Leizhou Peninsula area, Lingshui in Hainan province and Huangshadong in Guangzhou were selected from some key potential target area along the southeast coast of China. Deep geothermal field model of the study area is established based on the comprehensive analysis of the target area of deep geothermal geological background and deep thermal anomalies. This paper also compared the hot dry rock resources target locations, and proposed suggestions for the priority exploration target area and exploration scheme.

  19. Investigation of superstructure damping identification for the HDR containment building

    International Nuclear Information System (INIS)

    Hsieh, B.J.; Kot, C.A.; Srinivasan, M.G.

    1985-01-01

    A method for the estimation of first mode structural damping, developed by other investigators, was applied to shaker test data of the HDR containment building. Due to inadequate precision in the experimental phase measurements no valid results could be obtained. Based on modal analysis it was also noted that for systems such as the HDR building, contributions of higher modes are not negligible as was assumed in the original approach. Therefore, the procedure for the determination of superstructure damping using experimental data was extended to include the effects of higher modes. The extended method does not lead to any higher order nonlinear equations than the first mode approximation and was found to be as simple to apply as the original approach

  20. Intraoperative HDR implant boost for breast cancer (preliminary results)

    International Nuclear Information System (INIS)

    Rodriguez, I.; Torre, M. de la; Gonzalez, E.; Bourel, V.

    1996-01-01

    Introduction: In spite of the fact that it is been discussed whether or not a boost is necessary for all conservative treated breast cancer patients, it is a generalized radiotherapy practice. Since september 1993 we developed a breast conservative protocol for early stage breast cancer (T1-T2) with intraoperative HDR implant boost. Side effects, cosmetic results and recurrence rates are reviewed. Method and Material: From September 1993 we treated 55 patients with intraoperative HDR implant boost to the lumpectomy site for clinical T1 or T2 invasive breast cancer, followed by external megavoltage radiotherapy to the entire breast. We used the Nucletron microselectron HDR remote afterloading system with flexible implant tubes. The geometric distribution of the tubes was performed according to the 'Paris' configuration. Each implant was evaluated by calculating the dose-volume natural histograms. The HDR fractionation schedule consists of three fractions of 4.5Gy each given at least 48 hs apart, and starting between 48-72hs from surgical procedure. The external radiotherapy to the entire breast started one week after the completion of brachytherapy, using conventional fractionation of 5 fractions per week, 1,8Gy per fraction up to 45-50Gy. Results: So far there is not any local recurrence, but medium follow up is only 18 months. We did not observe any acute damage and the cosmetic outcome was 60% excellent, 30% good and 10% acceptable. Two patients developed localized fibrosis, in both the implant involved the submamary fold. Conclusion: The intraoperative implant is the most accurate way to localize the lumpectomy site, to define the target volume, decrease the total treatment time and avoid a second anesthetic procedure without delaying the inpatient time or the initial wound healing process

  1. The use of nomograms in LDR-HDR prostate brachytherapy.

    Science.gov (United States)

    Pujades, Ma Carmen; Camacho, Cristina; Perez-Calatayud, Jose; Richart, José; Gimeno, Jose; Lliso, Françoise; Carmona, Vicente; Ballester, Facundo; Crispín, Vicente; Rodríguez, Silvia; Tormo, Alejandro

    2011-09-01

    The common use of nomograms in Low Dose Rate (LDR) permanent prostate brachytherapy (BT) allows to estimate the number of seeds required for an implant. Independent dosimetry verification is recommended for each clinical dosimetry in BT. Also, nomograms can be useful for dose calculation quality assurance and they could be adapted to High Dose Rate (HDR). This work sets nomograms for LDR and HDR prostate-BT implants, which are applied to three different institutions that use different implant techniques. Patients treated throughout 2010 till April 2011 were considered for this study. This example was chosen to be the representative of the latest implant techniques and to ensure consistency in the planning. A sufficient number of cases for both BT modalities, prescription dose and different work methodology (depending on the institution) were taken into account. The specific nomograms were built using the correlation between the prostate volume and some characteristic parameters of each BT modality, such as the source Air Kerma Strength, number of implanted seeds in LDR or total radiation time in HDR. For each institution and BT modality, nomograms normalized to the prescribed dose were obtained and fitted to a linear function. The parameters of the adjustment show a good agreement between data and the fitting. It should be noted that for each institution these linear function parameters are different, indicating that each centre should construct its own nomograms. Nomograms for LDR and HDR prostate brachytherapy are simple quality assurance tools, specific for each institution. Nevertheless, their use should be complementary to the necessary independent verification.

  2. The use of nomograms in LDR-HDR prostate brachytherapy

    Directory of Open Access Journals (Sweden)

    Ma Carmen Pujades

    2011-09-01

    Full Text Available Purpose: The common use of nomograms in Low Dose Rate (LDR permanent prostate brachytherapy (BT allowsto estimate the number of seeds required for an implant. Independent dosimetry verification is recommended for eachclinical dosimetry in BT. Also, nomograms can be useful for dose calculation quality assurance and they could be adaptedto High Dose Rate (HDR. This work sets nomograms for LDR and HDR prostate-BT implants, which are applied tothree different institutions that use different implant techniques. Material and methods: Patients treated throughout 2010 till April 2011 were considered for this study. This examplewas chosen to be the representative of the latest implant techniques and to ensure consistency in the planning. A sufficientnumber of cases for both BT modalities, prescription dose and different work methodology (depending on theinstitution were taken into account. The specific nomograms were built using the correlation between the prostatevo lume and some characteristic parameters of each BT modality, such as the source Air Kerma Strength, numberof implanted seeds in LDR or total radiation time in HDR. Results: For each institution and BT modality, nomograms normalized to the prescribed dose were obtained andfitted to a linear function. The parameters of the adjustment show a good agreement between data and the fitting.It should be noted that for each institution these linear function parameters are different, indicating that each centreshould construct its own nomograms. Conclusions: Nomograms for LDR and HDR prostate brachytherapy are simple quality assurance tools, specific foreach institution. Nevertheless, their use should be complementary to the necessary independent verification.

  3. Progress report on research and development activities of the Institut fuer Neutronenphysik und Reaktortechnik in 1980

    International Nuclear Information System (INIS)

    1981-02-01

    The Institut fuer Neutronenphysik und Reaktortechnik carries out research in nuclear enginering especially in the context of the development of sodium-cooled fast breeder reactors. The institute does theoretical and experimental work in equal shares. Most of the work is done in cooperation with other institutes and industrial groups. In the framework of the Projekt Schneller Brueter , the institute investigates the layout and safety problems, from a reactor physics point of view of large fast breeder cores. Problems concerning the effects of LWR accidents on population and environment are investigated in the Projekt Nukleare Sicherheit . To the Projekt Wiederaufarbeitung , the institute is contributing work on fuel cycle physics and the development of a suitable instrumentation. In the field of nuclear safeguards, the implementation of monitoring systems is being investigated. Research outside projects is being done on technical and physical problems of fusion by inertial confinement and application of nuclear power on the transportation sector with hydrogen as an energy source. The main results obtained in 1980 in the various projects are presented. (orig./RW) [de

  4. Traceable calibration of hospital 192Ir HDR sources

    International Nuclear Information System (INIS)

    Govinda Rajan, K.N.; Bhatt, B.C.; Pendse, A.M.; Kannan, V.

    2002-01-01

    Presently, no primary standard exists for the standardization of remote afterloading 192 Ir HDR sources. These sources are, therefore, being standardized by a few Secondary Standard Dosimetry Laboratories (SSDLs), in terms of Air Kerma Strength (AKS) or Reference Air Kerma Rate (RAKR) using a 0.6 cc Farmer type chamber, set up as an Interim Standard. These SSDLs offer calibration to well type of ionization chambers that are normally used by the hospitals for calibrating the 192 lr HDR source. Presently, in many countries, including India, well chambers are not commercially available. Nor do these countries offer any calibration service for 192 lr HDR source. With the result users make use of well chambers imported from different countries with their calibration traceable to the country of origin. Since no intercomparisons between these countries have been reported, the measurement consistency between hospitals becomes questionable. The problem is compounded by the fact that these chambers are used for several years without re-calibration since no calibration service is locally available. For instance, in India, the chambers have been in use in hospitals, since 1994, without a second calibration. Not all hospitals use the well chamber for the calibration of the 192 lr HDR source. Many hospitals make use of 0.6 cc chambers, in air, at short source to chamber distances, for measuring the AKS of the source. The latter method is prone to much larger inaccuracy due to the use of very short source to chamber distances without proper calibration jigs, use of 60 Co calibration factor for 192 Ir HDR source calibrations, neglecting correction factors for room scatter, fluence non-uniformity, use of arbitrary buildup factors for the buildup cap of the chamber etc. A comparison of the procedures used at hospitals revealed that various arbitrary methods are in use at hospitals. An indigenously developed well chamber was calibrated against a Reference Standard traceable to the

  5. Rendering of HDR content on LDR displays: an objective approach

    Science.gov (United States)

    Krasula, Lukáš; Narwaria, Manish; Fliegel, Karel; Le Callet, Patrick

    2015-09-01

    Dynamic range compression (or tone mapping) of HDR content is an essential step towards rendering it on traditional LDR displays in a meaningful way. This is however non-trivial and one of the reasons is that tone mapping operators (TMOs) usually need content-specific parameters to achieve the said goal. While subjective TMO parameter adjustment is the most accurate, it may not be easily deployable in many practical applications. Its subjective nature can also influence the comparison of different operators. Thus, there is a need for objective TMO parameter selection to automate the rendering process. To that end, we investigate into a new objective method for TMO parameters optimization. Our method is based on quantification of contrast reversal and naturalness. As an important advantage, it does not require any prior knowledge about the input HDR image and works independently on the used TMO. Experimental results using a variety of HDR images and several popular TMOs demonstrate the value of our method in comparison to default TMO parameter settings.

  6. Vibrational experiments at the HDR [Heissdampfreaktor] German/US cooperation

    International Nuclear Information System (INIS)

    Kot, C.A.; Malcher, L.; Costello, J.F.

    1987-04-01

    As part of an overall effort on the validation of seismic calculational methods, the US NRC/RES is collaborating with the Kernforschungszentrum Karlsruhe, FRG, in the vibrational/earthquake experiments conducted at the HDR (Heissdampfreaktor) Test Facility in Kahl/Main, FRG. In the most recent experiments (SHAG), high level excitations were produced in the HDR by means of an eccentric-mass coastdown shaker capable of developing 1000 tons of force. The purpose of the experiments was to investigate full-scale structural response, soil-structure interaction, and piping and equipment response. Data obtained in the tests serve to evaluate analysis methods. In the SHAG experiments, loadings of the HDR soil-structure system approached incipient failure levels as evidenced by high peak accelerations and displacements, local damage, nonlinear behavior, soil subsidence, and wall strains which exceeded estimated limit values. Also, the performance of different pipe hanger configurations for the VKL piping system was compared in these tests under high excitation levels. The support configurations ranged from very rigid systems (strut/snubbers) to very flexible configurations (spring and constant force supports). Pretest and post-test analyses for the building/soil and piping response were performed and are being validated with the test data

  7. CFD simulation of a particle loaded coolant flow in the sump and in the condensation chamber; Entwicklung von CFD-Modellen fuer Wandsieden und Entwicklung hchaufloesender, schneller Roentgentomographie fuer die Analyse von Zweiphasenstroemungen in Brennstabbuendeln

    Energy Technology Data Exchange (ETDEWEB)

    Krepper, Eckhard; Rzehak, Roland; Barthel, Frank; Franz, Ronald; Hampel, Uwe

    2013-07-01

    A collaborative project funded by the BMBF in the framework of the R and D program ''Energie 2020+'' by 4 Universities, 2 Research Centres and ANSYS was coordinated by Helmholtz- Zentrum Dresden-Rossendorf (HZDR). The present report describes the contributions of HZDR done from September 2009 to January 2013. The project was directed towards the development and validation of CFD models of boiling processes in PWR in the range from subcooled nucleate boiling up to the critical heat flux. The report describes the developed and used models. Main achievements were a comprehensive study of the boiling process itself and a better description of the interfacial area by coupling of wall boiling with a population balance model. The model extensions are validated and the present capabilities of CFD for wall boiling are investigated. By means of rod bundle experiments was shown that the measured cross sectional averaged values can be reproduced well with a single set of calibrated model parameters for different tests cases. For the reproduction of patterns of void distribution cross sections attention has to be focussed on the modelling of turbulence in the narrow channel. The experimental work was focussed on the investigation of the flow in a rod bundle. Using a rod bundle test rig the turbulent single phase flow field (PIV) and the average gas volume fraction (gamma densitometry) are measured. The timely and spatial resolved gas fraction was measured applying the ''High speed x-ray tomography'', developed in Rossendorf.

  8. WE-F-BRD-01: HDR Brachytherapy II: Integrating Imaging with HDR

    Energy Technology Data Exchange (ETDEWEB)

    Craciunescu, O [Duke University Medical Center, Durham, NC (United States); Todor, D [Virginia Commonwealth University, Richmond, VA (United States); Leeuw, A de

    2014-06-15

    In recent years, with the advent of high/pulsed dose rate afterloading technology, advanced treatment planning systems, CT/MRI compatible applicators, and advanced imaging platforms, image-guided adaptive brachytherapy treatments (IGABT) have started to play an ever increasing role in modern radiation therapy. The most accurate way to approach IGABT treatment is to provide the infrastructure that combines in a single setting an appropriate imaging device, a treatment planning system, and a treatment unit. The Brachytherapy Suite is not a new concept, yet the modern suites are incorporating state-of-the-art imaging (MRI, CBCT equipped simulators, CT, and /or US) that require correct integration with each other and with the treatment planning and delivery systems. Arguably, an MRI-equipped Brachytherapy Suite is the ideal setup for real-time adaptive brachytherapy treatments. The main impediment to MRI-IGABT adoption is access to MRI scanners. Very few radiation oncology departments currently house MRI scanners, and even fewer in a dedicated Brachytherapy Suite. CBCT equipped simulators are increasingly offered by manufacturers as part of a Brachytherapy Suite installation. If optimized, images acquired can be used for treatment planning, or can be registered with other imaging modalities. This infrastructure is relevant for all forms of brachytherapy, especially those utilizing multi-fractionated courses of treatment such as prostate and cervix. Moreover, for prostate brachytherapy, US imaging systems can be part of the suite to allow for real-time HDR/LDR treatments. Learning Objectives: Understand the adaptive workflow of MR-based IGBT for cervical cancer. Familiarize with commissioning aspects of a CBCT equipped simulator with emphasis on brachytherapy applications Learn about the current status and future developments in US-based prostate brachytherapy.

  9. WE-F-BRD-01: HDR Brachytherapy II: Integrating Imaging with HDR

    International Nuclear Information System (INIS)

    Craciunescu, O; Todor, D; Leeuw, A de

    2014-01-01

    In recent years, with the advent of high/pulsed dose rate afterloading technology, advanced treatment planning systems, CT/MRI compatible applicators, and advanced imaging platforms, image-guided adaptive brachytherapy treatments (IGABT) have started to play an ever increasing role in modern radiation therapy. The most accurate way to approach IGABT treatment is to provide the infrastructure that combines in a single setting an appropriate imaging device, a treatment planning system, and a treatment unit. The Brachytherapy Suite is not a new concept, yet the modern suites are incorporating state-of-the-art imaging (MRI, CBCT equipped simulators, CT, and /or US) that require correct integration with each other and with the treatment planning and delivery systems. Arguably, an MRI-equipped Brachytherapy Suite is the ideal setup for real-time adaptive brachytherapy treatments. The main impediment to MRI-IGABT adoption is access to MRI scanners. Very few radiation oncology departments currently house MRI scanners, and even fewer in a dedicated Brachytherapy Suite. CBCT equipped simulators are increasingly offered by manufacturers as part of a Brachytherapy Suite installation. If optimized, images acquired can be used for treatment planning, or can be registered with other imaging modalities. This infrastructure is relevant for all forms of brachytherapy, especially those utilizing multi-fractionated courses of treatment such as prostate and cervix. Moreover, for prostate brachytherapy, US imaging systems can be part of the suite to allow for real-time HDR/LDR treatments. Learning Objectives: Understand the adaptive workflow of MR-based IGBT for cervical cancer. Familiarize with commissioning aspects of a CBCT equipped simulator with emphasis on brachytherapy applications Learn about the current status and future developments in US-based prostate brachytherapy

  10. Independent technique of verifying high-dose rate (HDR) brachytherapy treatment plans

    International Nuclear Information System (INIS)

    Saw, Cheng B.; Korb, Leroy J.; Darnell, Brenda; Krishna, K. V.; Ulewicz, Dennis

    1998-01-01

    Purpose: An independent technique for verifying high-dose rate (HDR) brachytherapy treatment plans has been formulated and validated clinically. Methods and Materials: In HDR brachytherapy, dwell times at respective dwell positions are computed, using an optimization algorithm in a HDR treatment-planning system to deliver a specified dose to many target points simultaneously. Because of the variability of dwell times, concerns have been expressed regarding the ability of the algorithm to compute the correct dose. To address this concern, a commercially available low-dose rate (LDR) algorithm was used to compute the doses at defined distances, based on the dwell times obtained from the HDR treatment plans. The percent deviation between doses computed using the HDR and LDR algorithms were reviewed for HDR procedures performed over the last year. Results: In this retrospective study, the difference between computed doses using the HDR and LDR algorithms was found to be within 5% for about 80% of the HDR procedures. All of the reviewed procedures have dose differences of less than 10%. Conclusion: An independent technique for verifying HDR brachytherapy treatment plans has been validated based on clinical data. Provided both systems are available, this technique is universal in its applications and not limited to either a particular implant applicator, implant site, or implant type

  11. Simultaneous radiochemotherapy and endoluminal HDR brachytherapy in esophageal cancer; Simultane Radiochemotherapie mit intraluminaler HDR-Brachytherapie des Oesophaguskarzinoms

    Energy Technology Data Exchange (ETDEWEB)

    Patonay, P.; Naszaly, A.; Mayer, A. [Hauptstaedtisches Zentrum fuer Radioonkologie und Strahlentherapie, Budapest (Hungary)

    2007-02-15

    Purpose: to study efficacy and toxicity of radiochemotherapy in esophageal cancer including initial endoluminal high-dose-rate brachytherapy (HDR-BT). Patients and methods: between 01/1995 and 06/2005, 61 patients with esophageal cancer were treated preoperatively with definitive and palliative intent. Treatment started with intraluminal HDR-BT for recanalization of the esophagus (single fraction size of 8 Gy in 0.5 cm depth, three times, q7d) followed by external-beam radiation therapy (50 Gy total dose, 5 x 2 Gy/week, 25 fractions in 5 weeks). Chemotherapy was started simultaneously with external irradiation (three courses of cisplatin and 5-fluorouracil, q21d). Results: swallowing function improved in 55/61 patients (dysphagia classification according to the RTOG), and worsened in 6/61 patients, respectively. Median duration of symptomatic improvement was 11 months, median follow-up 12 months (range 3-68 months). Following simultaneous radiochemotherapy, tumor resectability was achieved in 7/25 patients of the neoadjuvant group, and the histological specimen showed complete remission in 6/7 patients. Conclusion: these results indicate a favorable effect of simultaneous radiochemotherapy starting with endoluminal HDR-after-loading-(AL-)BT in esophageal cancer. (orig.)

  12. Fotografie und atomare Katastrophe

    OpenAIRE

    Bürkner, Daniel

    2015-01-01

    Die Dissertation setzt sich mit den fotografischen Repräsentationen der Atombombenabwürfe auf Hiroshima und Nagasaki sowie der Havarie des Kernkraftwerks Tschernobyl auseinander. Dabei werden künstlerische, dokumentarische und touristische Bilder analysiert, die sich der jeweiligen Strahlenkatastrophe oftmals erst Jahre nach dem Ereignis annehmen und ikonografische oder medial-materielle Bezüge zu ihr aufweisen. Es zeigen sich zentrale Strategien, atomare Katastrophen, seien sie militäri...

  13. Versicherung und volkswirtschaftlicher Kreislauf

    OpenAIRE

    Lampert, Heinz

    1982-01-01

    Versicherung und volkswirtschaftlicher Kreislauf : zur Behandlung d. Privatversicherung in d. volkswirtschaftl. Gesamtrechnung. - In: Zeitschrift für die gesamte Versicherungswissenschaft. 71. 1982. S. 189-210

  14. SU-E-T-124: Dosimetric Comparison of HDR Brachytherapy and Intensity Modulated Proton Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Wu, J [Purdue University, West Lafayette, IN (United States); Wu, H [IUPUI, Indianapolis, IN (United States); Das, I [Indiana University- School of Medicine, Indianapolis, IN (United States)

    2014-06-01

    Purpose: Brachytherapy is known to be able to deliver more radiation dose to tumor while minimizing radiation dose to surrounding normal tissues. Proton therapy also provides superior dose distribution due to Bragg peak. Since both HDR and Intensity Modulated Proton Therapy (IMPT) are beneficial for their quick dose drop off, our goal in this study is to compare the pace of dose gradient drop-off between HDR and IMPT plans based on the same CT image data-set. In addition, normal tissues sparing were also compared among HDR, IMPT and SBRT. Methods: Five cervical cancer cases treated with EBRT + HDR boost combination with Tandem and Ovoid applicator were used for comparison purpose. Original HDR plans with prescribed dose of 5.5 Gy x 5 fractions were generated and optimized. The 100% isodose line of HDR plans was converted to a dose volume, and treated as CTV for IMPT and SBRT planning. The same HDR CT scans were also used for IMPT plan and SBRT plan for direct comparison. The philosophy of the IMPT and SBRT planning was to create the same CTV coverage as HDR plans. All three modalities treatment plans were compared to each other with a set of predetermined criteria. Results: With similar target volume coverage in cervix cancer boost treatment, HDR provides a slightly sharper dose drop-off from 100% to 50% isodose line, averagely in all directions compared to IMPT. However, IMPT demonstrated more dose gradient drop-off at the junction of the target and normal tissues by providing more normal tissue sparing and superior capability to reduce integral dose. Conclusion: IMPT is capable of providing comparable dose drop-off as HDR. IMPT can be explored as replacement for HDR brachytherapy in various applications.

  15. Milch, Milchprodukte, Analoge und Speiseeis

    Science.gov (United States)

    Coors, Ursula

    Die Produktpalette Milch und Erzeugnisse aus Milch beinhaltet Konsummilch, die aus Milch oder Bestandteilen der Milch hergestellten Milcherzeugnisse wie Sauermilch-, Joghurt-, Kefir-, Buttermilch-, Sahne-, Kondensmilch-, Trockenmilch- und Molkenerzeugnisse, Milchmisch- und Molkenmischprodukte (Produkte mit beigegebenen Lebensmitteln), Milchzucker, Milcheiweißerzeugnisse, Milchfette und Käse.

  16. Übergewicht und Adipositas in Kindheit und Jugend

    OpenAIRE

    Nitzko, Sina

    2010-01-01

    Einführend wird auf wesentliche Entwicklungsaspekte der interessierenden Lebensphasen Kindheit und Jugend eingegangen. Im Anschluss daran werden verschiedene Aspekte von Übergewicht und Adipositas in Kindheit und Jugend thematisiert. Neben der Definition und Diagnostik, wird auf Möglichkeiten der Klassifikation sowie die Epidemiologie eingegangen. Dargestellt werden darüber hinaus körperliche und psychische Folgestörungen, welche mit Adipositas assoziiert sein können. Basierend auf der...

  17. MO-B-BRC-00: Prostate HDR Treatment Planning - Considering Different Imaging Modalities

    International Nuclear Information System (INIS)

    2016-01-01

    Brachytherapy has proven to be an effective treatment option for prostate cancer. Initially, prostate brachytherapy was delivered through permanently implanted low dose rate (LDR) radioactive sources; however, high dose rate (HDR) temporary brachytherapy for prostate cancer is gaining popularity. Needle insertion during prostate brachytherapy is most commonly performed under ultrasound (U/S) guidance; however, treatment planning may be performed utilizing several imaging modalities either in an intra- or post-operative setting. During intra-operative prostate HDR, the needles are imaged during implantation, and planning may be performed in real time. At present, the most common imaging modality utilized for intra-operative prostate HDR is U/S. Alternatively, in the post-operative setting, following needle implantation, patients may be simulated with computed tomography (CT) or magnetic resonance imaging (MRI). Each imaging modality and workflow provides its share of benefits and limitations. Prostate HDR has been adopted in a number of cancer centers across the nation. In this educational session, we will explore the role of U/S, CT, and MRI in HDR prostate brachytherapy. Example workflows and operational details will be shared, and we will discuss how to establish a prostate HDR program in a clinical setting. Learning Objectives: Review prostate HDR techniques based on the imaging modality Discuss the challenges and pitfalls introduced by the three imagebased options for prostate HDR brachytherapy Review the QA process and learn about the development of clinical workflows for these imaging options at different institutions

  18. MO-B-BRC-00: Prostate HDR Treatment Planning - Considering Different Imaging Modalities

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2016-06-15

    Brachytherapy has proven to be an effective treatment option for prostate cancer. Initially, prostate brachytherapy was delivered through permanently implanted low dose rate (LDR) radioactive sources; however, high dose rate (HDR) temporary brachytherapy for prostate cancer is gaining popularity. Needle insertion during prostate brachytherapy is most commonly performed under ultrasound (U/S) guidance; however, treatment planning may be performed utilizing several imaging modalities either in an intra- or post-operative setting. During intra-operative prostate HDR, the needles are imaged during implantation, and planning may be performed in real time. At present, the most common imaging modality utilized for intra-operative prostate HDR is U/S. Alternatively, in the post-operative setting, following needle implantation, patients may be simulated with computed tomography (CT) or magnetic resonance imaging (MRI). Each imaging modality and workflow provides its share of benefits and limitations. Prostate HDR has been adopted in a number of cancer centers across the nation. In this educational session, we will explore the role of U/S, CT, and MRI in HDR prostate brachytherapy. Example workflows and operational details will be shared, and we will discuss how to establish a prostate HDR program in a clinical setting. Learning Objectives: Review prostate HDR techniques based on the imaging modality Discuss the challenges and pitfalls introduced by the three imagebased options for prostate HDR brachytherapy Review the QA process and learn about the development of clinical workflows for these imaging options at different institutions.

  19. Characteristics of hearing loss in HDR (hypoparathyroidism, sensorineural deafness, renal dysplasia) syndrome

    NARCIS (Netherlands)

    van Looij, Marjolein A. J.; Meijers-Heijboer, Hanne; Beetz, Rolf; Thakker, Rajesh V.; Christie, Paul T.; Feenstra, Lou W.; van Zanten, Bert G. A.

    2006-01-01

    Haploinsufficiency of the zinc finger transcription factor GATA3 causes the triad of hypoparathyroidism, deafness and renal dysplasia, known by its acronym HDR syndrome. The purpose of the current study was to describe in detail the auditory phenotype in human HDR patients and compare these to

  20. TU-C-201-01: Clinical Implementation of HDR: A New User’s Perspective

    Energy Technology Data Exchange (ETDEWEB)

    Al-Hallaq, H. [The University of Chicago (United States)

    2015-06-15

    Recent use of HDR has increased while planning has become more complex often necessitating 3D image-based planning. While many guidelines for the use of HDR exist, they have not kept pace with the increased complexity of 3D image-based planning. Furthermore, no comprehensive document exists to describe the wide variety of current HDR clinical indications. This educational session aims to summarize existing national and international guidelines for the safe implementation of an HDR program. A summary of HDR afterloaders available on the market and their existing applicators will be provided, with guidance on how to select the best fit for each institution’s needs. Finally, the use of checklists will be discussed as a means to implement a safe and efficient HDR program and as a method by which to verify the quality of an existing HDR program. This session will provide the perspective of expert HDR physicists as well as the perspective of a new HDR user. Learning Objectives: Summarize national and international safety and staffing guidelines for HDR implementation Discuss the process of afterloader and applicator selection for gynecologic, prostate, breast, interstitial, surface treatments Learn about the use of an audit checklist tool to measure of quality control of a new or existing HDR program Describe the evolving use of checklists within an HDR program.

  1. Thermodynamik grundlagen und technische anwendungen

    CERN Document Server

    Baehr, Hans Dieter

    2009-01-01

    Für die aktualisierte 14. Auflage des bewährten Lehrbuchs der Technischen Thermodynamik wurde das Kapitel über Wärmekraftanlagen gründlich bearbeitet und durch einen Abschnitt zur Energiewandlung ergänzt: Die Energiebedarfsstruktur von Deutschland wird erläutert, und die möglichen Energiewandlungspfade werden diskutiert. Schwerpunkt des Buches ist die ausführliche und auch dem Anfänger verständliche Darstellung der Grundlagen der Thermodynamik mit der sorgfältigen Einführung der thermodynamischen Begriffe und den fundamentalen Bilanzgleichungen für Energie, Entropie und Exergie. Die thermodynamischen Eigenschaften reiner Fluide und fluider Gemische werden eingehend erläutert. Darauf aufbauend wird die Thermodynamik der Gemische und der chemischen Reaktionen entwickelt. Auch die thermodynamischen Aspekte wichtiger energie- und verfahrenstechnischer Anwendungen werden praxisnah behandelt: - Strömungs- und Arbeitsprozesse, - thermische Stofftrennverfahren, - Verbrennungsprozesse und Verbrennungsk...

  2. : Light Steering Projection Systems and Attributes for HDR Displays

    KAUST Repository

    Damberg, Gerwin

    2017-06-02

    New light steering projectors in cinema form images by moving light away from dark regions into bright areas of an image. In these systems, the peak luminance of small features can far exceed full screen white luminance. In traditional projectors where light is filtered or blocked in order to give shades of gray (or colors), the peak luminance is fixed. The luminance of chromatic features benefit in the same way as white features, and chromatic image details can be reproduced at high brightness leading to a much wider overall color gamut coverage than previously possible. Projectors of this capability are desired by the creative community to aid in and enhance storytelling. Furthermore, reduced light source power requirements of light steering projectors provide additional economic and environmental benefits. While the dependency of peak luminance level on (bright) image feature size is new in the digital cinema space, display technologies with identical characteristics such as OLED, LED LCD and Plasma TVs are well established in the home. Similarly, direct view LED walls are popular in events, advertising and architectural markets. To enable consistent color reproduction across devices in today’s content production pipelines, models that describe modern projectors and display attributes need to evolve together with HDR standards and available metadata. This paper is a first step towards rethinking legacy display descriptors such as contrast, peak luminance and color primaries in light of new display technology. We first summarize recent progress in the field of light steering projectors in cinema and then, based on new projector and existing display characteristics propose the inclusion of two simple display attributes: Maximum Average Luminance and Peak (Color) Primary Luminance. We show that the proposed attributes allow a better prediction of content reproducibility on HDR displays. To validate this assertion, we test professional content on a commercial HDR

  3. Realistic camera noise modeling with application to improved HDR synthesis

    Science.gov (United States)

    Goossens, Bart; Luong, Hiêp; Aelterman, Jan; Pižurica, Aleksandra; Philips, Wilfried

    2012-12-01

    Due to the ongoing miniaturization of digital camera sensors and the steady increase of the "number of megapixels", individual sensor elements of the camera become more sensitive to noise, even deteriorating the final image quality. To go around this problem, sophisticated processing algorithms in the devices, can help to maximally exploit the knowledge on the sensor characteristics (e.g., in terms of noise), and offer a better image reconstruction. Although a lot of research focuses on rather simplistic noise models, such as stationary additive white Gaussian noise, only limited attention has gone to more realistic digital camera noise models. In this article, we first present a digital camera noise model that takes several processing steps in the camera into account, such as sensor signal amplification, clipping, post-processing,.. We then apply this noise model to the reconstruction problem of high dynamic range (HDR) images from a small set of low dynamic range (LDR) exposures of a static scene. In literature, HDR reconstruction is mostly performed by computing a weighted average, in which the weights are directly related to the observer pixel intensities of the LDR image. In this work, we derive a Bayesian probabilistic formulation of a weighting function that is near-optimal in the MSE sense (or SNR sense) of the reconstructed HDR image, by assuming exponentially distributed irradiance values. We define the weighting function as the probability that the observed pixel intensity is approximately unbiased. The weighting function can be directly computed based on the noise model parameters, which gives rise to different symmetric and asymmetric shapes when electronic noise or photon noise is dominant. We also explain how to deal with the case that some of the noise model parameters are unknown and explain how the camera response function can be estimated using the presented noise model. Finally, experimental results are provided to support our findings.

  4. HDR brachytherapy for superficial non-melanoma skin cancers

    International Nuclear Information System (INIS)

    Gauden, Ruth; Pracy, Martin; Avery, Anne-Marie; Hodgetts, Ian; Gauden, Stan

    2013-01-01

    Our initial experience using recommended high dose per fraction skin brachytherapy (BT) treatment schedules, resulted in poor cosmesis. This study aimed to assess in a prospective group of patients the use of Leipzig surface applicators for High Dose Rate (HDR) brachytherapy, for the treatment of small non-melanoma skin cancers (NMSC) using a protracted treatment schedule. Treatment was delivered by HDR brachytherapy with Leipzig applicators. 36Gy, prescribed to between 3 to 4mm, was given in daily 3Gy fractions. Acute skin toxicity was evaluated weekly during irradiation using the Radiation Therapy Oncology Group criteria. Local response, late skin effects and cosmetic results were monitored at periodic intervals after treatment completion. From March 2002, 200 patients with 236 lesions were treated. Median follow-up was 66 months (range 25–121 months). A total of 162 lesions were macroscopic, while in 74 cases, BT was given after resection because of positive microscopic margins. There were 121 lesions that were basal cell carcinomas, and 115 were squamous cell carcinomas. Lesions were located on the head and neck (198), the extremities (26) and trunk (12). Local control was 232/236 (98%). Four patients required further surgery to treat recurrence. Grade 1 acute skin toxicity was detected in 168 treated lesions (71%) and grade 2 in 81 (34%). Cosmesis was good or excellent in 208 cases (88%). Late skin hypopigmentation changes were observed in 13 cases (5.5%). Delivering 36Gy over 2 weeks to superficial NMSC using HDR brachytherapy is well tolerated and provides a high local control rate without significant toxicity.

  5. Steuern und Governance

    Directory of Open Access Journals (Sweden)

    Eduard Müller

    2014-05-01

    Full Text Available ENGLISH: Taxation, in the modern state, has long been a mass phenomenon with an interdisciplinary outlook. On the macro level of the state, a new generation of administrative reforms has crystallized under the label “good public governance”. These reforms seek to resolve regulatory interdependence of state and non - state actors by way of cooperation and interaction. In parallel, on the micro level of businesses, “corporate governance” – voluntary compliance with legal and ethical standards – has become an increasingly important issue. With a view to tax law and tax collection, these developments open up new possibilities to raise tax compliance by means of consensual and cooperative instruments and, accordingly, address taxation as a mass phenomenon. DEUTSCH: Besteuerung ist im modernen Staat ein Massenphänomen und längst interdisziplinär ausgerichtet. Auf der Makro-Ebene des Staates hat sich unter dem Begriff Good Public Governance eine neue Generation von Staats- und Verwaltungsreformen herausgebildet, die Regelungsbeziehungen von staatlichen und nichtstaatlichen Akteuren durch Kooperationen und Interaktionen zu lösen versucht. Parallel dazu hat auf der Mikro-Ebene der Unternehmen mit dem Thema Corporate Governance die freiwillige Einhaltung von rechtlichen und ethischen Regeln an Bedeutung gewonnen. Für das Steuerrecht und den Steuervollzug resultieren aus diesen Entwicklungen neue Möglichkeiten, durch Nutzung konsens- und kooperationsorientierter Instrumente die Tax Compliance zu erhöhen und so dem Massenphänomen Besteuerung gerecht zu werden.

  6. Osteoporose und Laktoseintoleranz

    Directory of Open Access Journals (Sweden)

    Obermayer-Pietsch B

    2008-01-01

    Full Text Available Laktosemalabsorption oder Laktoseintoleranz ist eine symptomatische Unverträglichkeit von Milchzucker (Laktose, zumeist aufgrund einer autosomal rezessiv erblichen, irreversiblen Abnahme des Enzyms Laktase im Jugendalter, die bei etwa der Hälfte der Weltbevölkerung auftritt. Die Betroffenen meiden oft instinktiv Milch und Milchprodukte wegen der damit verbundenen Malabsorptions-Symptome. Damit scheiden diese Nahrungsmittel aber auch als Kalziumlieferanten aus und es kann zu einer Mangelversorgung des Knochens mit Kalzium und damit zu Osteoporose kommen. Da in Österreich etwa 20–25 % der Bevölkerung betroffen sind, ist diese Stoffwechselveränderung nicht zu vernachlässigen. Diagnostische und begleitende ernährungsmedizinische Maßnahmen und gegebenenfalls eine osteotrope Therapie sollten zum Erhalt der Knochenmasse eingesetzt werden.

  7. Neuausrichtung und Konsolidierung

    Science.gov (United States)

    Grohmann, Heinz

    Mit der Wahl von Wolfgang Wetzel zum Vorsitzenden der Deutschen Statistischen Gesellschaft im Jahre 1972 begann eine 32jährige Ära, in der die praktische und die theoretische Statistik in einem ausgewogenen Verhältnis gepflegt wurden. Ein regelmäßiger vierjähriger Wechsel im Vorsitz stärkte die Gemeinschaft und die praktische wie die wissenschaftliche Arbeit gleichermaßen. Die jährlichen Hauptversammlungen behandelten gesellschaftlich aktuelle wie zukunftsorientierte Themen, und die Ausschüsse sowie weitere Veranstaltungen gaben Gelegenheit zur Förderung und Pflege einer Vielzahl von Arbeitsgebieten der Statistik. Darüber wird nicht nur in diesem Kapitel, sondern auch in den Teilen II und III des Bandes berichtet.

  8. Cost modelling of electricity-producing hot dry rock (HDR) geothermal systems in the United Kingdom

    International Nuclear Information System (INIS)

    Doherty, P.; Harrison, R.

    1995-01-01

    A detailed and comprehensive cost model for Hot Dry Rock (HDR) electricity producing systems has been developed in this study. The model takes account of the major aspects of the HDR system, parameterized in terms of the main physical and cost parameters of the resource and the utilization system. A doublet configuration is assumed, and the conceptual HDR system which is defined in the study is based upon the UK Department of Energy (DEn) HDR geothermal R and D programme. The model has been used to calculate the costs of HDR electricity for a UK defined base case which represents a consensus view of what might be achieved in Cornwall in the long term. At 14.2 p/kWh (1988 costs) this cost appears to be unacceptably high. A wide-ranging sensitivity study has also been carried out on the main resource, geometrical, and operational parameters of the HDR system centred around the UK base case. The sensitivity study shows the most important parameters to be thermal gradient and depth. The geometrical arrangement and the shape of the reservoir constitute major uncertainties in HDR systems. Their effect on temperature has a major influence on system performance, and therefore a range of theoretically possible geometries have been studied and the importance of geometrical effects on HDR electricity costs assessed. The most cost effective HDR arrangement in terms of optimized volumes and flow rates has been investigated for a world-wide range of thermal settings. The main conclusions from this study suggests that for HDR electricity to be economic, thermal gradients of 55 o C/km and above, well depths of 5 km or less, and production fluid temperatures of 210 o C and above are required. (UK)

  9. Mathematical simulation of biologically equivalent doses for LDR-HDR

    International Nuclear Information System (INIS)

    Slosarek, K.; Zajusz, A.

    1996-01-01

    Based on the LQ model examples of biologically equivalent doses LDR, HDR and external beams were calculated. The biologically equivalent doses for LDR were calculated by appending to the LQ model the corrector for the time of repair of radiation sublethal damages. For radiation continuously delivered at a low dose rate the influence of sublethal damage repair time changes on biologically equivalent doses were analysed. For fractionated treatment with high dose rate the biologically equivalent doses were calculated by adding to the LQ model the formula of accelerated repopulation. For total biologically equivalent dose calculation for combine LDR-HDR-Tele irradiation examples are presented with the use of different parameters of the time of repair of sublethal damages and accelerated repopulation. The calculations performed show, that the same biologically equivalent doses can be obtained for different parameters of cell kinetics changes during radiation treatment. It also shows, that during biologically equivalent dose calculations for different radiotherapy schedules, ignorance of cell kinetics parameters can lead to relevant errors

  10. HDR IMAGING FOR FEATURE DETECTION ON DETAILED ARCHITECTURAL SCENES

    Directory of Open Access Journals (Sweden)

    G. Kontogianni

    2015-02-01

    Full Text Available 3D reconstruction relies on accurate detection, extraction, description and matching of image features. This is even truer for complex architectural scenes that pose needs for 3D models of high quality, without any loss of detail in geometry or color. Illumination conditions influence the radiometric quality of images, as standard sensors cannot depict properly a wide range of intensities in the same scene. Indeed, overexposed or underexposed pixels cause irreplaceable information loss and degrade digital representation. Images taken under extreme lighting environments may be thus prohibitive for feature detection/extraction and consequently for matching and 3D reconstruction. High Dynamic Range (HDR images could be helpful for these operators because they broaden the limits of illumination range that Standard or Low Dynamic Range (SDR/LDR images can capture and increase in this way the amount of details contained in the image. Experimental results of this study prove this assumption as they examine state of the art feature detectors applied both on standard dynamic range and HDR images.

  11. Fast exposure time decision in multi-exposure HDR imaging

    Science.gov (United States)

    Piao, Yongjie; Jin, Guang

    2012-10-01

    Currently available imaging and display system exists the problem of insufficient dynamic range, and the system cannot restore all the information for an high dynamic range (HDR) scene. The number of low dynamic range(LDR) image samples and fastness of exposure time decision impacts the real-time performance of the system dramatically. In order to realize a real-time HDR video acquisition system, this paper proposed a fast and robust method for exposure time selection in under and over exposure area which is based on system response function. The method utilized the monotony of the imaging system. According to this characteristic the exposure time is adjusted to an initial value to make the median value of the image equals to the middle value of the system output range; then adjust the exposure time to make the pixel value on two sides of histogram be the middle value of the system output range. Thus three low dynamic range images are acquired. Experiments show that the proposed method for adjusting the initial exposure time can converge in two iterations which is more fast and stable than average gray control method. As to the exposure time adjusting in under and over exposed area, the proposed method can use the dynamic range of the system more efficiently than fixed exposure time method.

  12. Fricke gel-layer dosimetry in HDR brachytherapy

    International Nuclear Information System (INIS)

    Gambarini, G.; Negri, A.; Carrara, M.; Marchesini, R.

    2008-01-01

    Full text: In the last decade, technological improvements in radiotherapy have been significant and consequently the use and importance of radiotherapy in cancer treatment have increased greatly. In brachytherapy, new possibilities have been opened by the impressive progresses in 3D imaging, by the development of sophisticated techniques for modern afterloaders and by the constantly increasing speed and capacity of computers. However, these methodological improvements require corresponding improvements in the dosimetry methods, in order to ensure that the values calculated with computer treatment planning systems, adopted in the clinical praxis, agree with the delivered dose distributions. Fricke gel-layer dosimeters (FGLD) are under study by our group as a reliable alternative to films, semiconductors arrays or thermoluminescent dosimeters (TLDs). In the last years, we have significantly improved this technique by defining the FGLD best chemical composition, by optimizing the image acquisition assessment and by developing a dedicated software for image analysis. In this study, experimental measurements of planar dose distributions of a clinical 192 Ir source (Microselectron HDR, Nucletron) obtained by irradiating a series of piled-up FGL dosimeters in a tissue-equivalent phantom are presented. The obtained results were in accordance to TLD measurements and to treatment planning system (Plato, Nucletron) calculations. FGLD have proven to be a reliable tool to achieve HDR brachytherapy dose distribution measurements

  13. High Brightness HDR Projection Using Dynamic Freeform Lensing

    KAUST Repository

    Damberg, Gerwin

    2016-05-03

    Cinema projectors need to compete with home theater displays in terms of image quality. High frame rate and spatial resolution as well as stereoscopic 3D are common features today, but even the most advanced cinema projectors lack in-scene contrast and, more important, high peak luminance, both of which are essential perceptual attributes of images appearing realistic. At the same time, HDR image statistics suggest that the average image intensity in a controlled ambient viewing environment such as the cinema can be as low as 1% for cinematic HDR content and not often higher than 18%, middle gray in photography. Traditional projection systems form images and colors by blocking the source light from a lamp, therefore attenuating between 99% and 82% of light, on average. This inefficient use of light poses significant challenges for achieving higher peak brightness levels. In this work, we propose a new projector architecture built around commercially available components, in which light can be steered to form images. The gain in system efficiency significantly reduces the total cost of ownership of a projector (fewer components and lower operating cost), and at the same time increases peak luminance and improves black level beyond what is practically achievable with incumbent projector technologies. At the heart of this computational display technology is a new projector hardware design using phase modulation in combination with a new optimization algorithm that is capable of on-the-fly computation of freeform lens surfaces. © 2016 ACM.

  14. Seismic investigations of the HDR Safety Program. Summary report

    International Nuclear Information System (INIS)

    Malcher, L.; Schrammel, D.; Steinhilber, H.; Kot, C.A.

    1994-08-01

    The primary objective of the seismic investigations, performed at the HDR facility in Kahl/Main, FRG was to validate calculational methods for the seismic evaluation of nuclear-reactor systems, using experimental data from an actual nuclear plant. Using eccentric mass shaker excitation the HDR soil/structure system was tested to incipient failure, exhibiting highly nonlinear response and demonstrating that structures not seismically designed can sustain loads equivalent to a design basin earthquake (DBE). Load transmission from the structure to piping/equipment indicated significant response amplifications and shifts to higher frequencies, while the response of tanks/vessels depended mainly on their support conditions. The evaluation of various piping support configurations demonstrated that proper system design (for a given spectrum) rather than number of supports or system stiffness is important to limiting pipe greens. Piping at loads exceeding the DBE eightfold still had significant margins and failure is improbable inspite of multiple support failures. The mean value for pipe damping, even under extreme loads, was found to be about 4%. Comparison of linear and nonlinear computational results with piping response measurements showed that predictions have a wide scatter and do not necessarily yield conservative responses underpredicting, in particular, peak support forces. For the soil/structure system the quality of the predictions did not depend so much on the complexity of the modeling, but rather on whether the model captured the salient features and nonlinearities of the system

  15. Prostate HDR brachytherapy catheter displacement between planning and treatment delivery

    International Nuclear Information System (INIS)

    Whitaker, May; Hruby, George; Lovett, Aimee; Patanjali, Nitya

    2011-01-01

    Background and purpose: HDR brachytherapy is used as a conformal boost for treating prostate cancer. Given the large doses delivered, it is critical that the volume treated matches that planned. Our outpatient protocol comprises two 9 Gy fractions, two weeks apart. We prospectively assessed catheter displacement between CT planning and treatment delivery. Materials and methods: Three fiducial markers and the catheters were implanted under transrectal ultrasound guidance. Metal marker wires were inserted into 4 reference catheters before CT; marker positions relative to each other and to the marker wires were measured from the CT scout. Measurements were repeated immediately prior to treatment delivery using pelvic X-ray with marker wires in the same reference catheters. Measurements from CT scout and film were compared. For displacements of 5 mm or more, indexer positions were adjusted prior to treatment delivery. Results: Results are based on 48 implants, in 25 patients. Median time from planning CT to treatment delivery was 254 min (range 81–367 min). Median catheter displacement was 7.5 mm (range −2.9–23.9 mm), 67% of implants had displacement of 5 mm or greater. Displacements were predominantly caudal. Conclusions: Catheter displacement can occur in the 1–3 h between the planning CT scan and treatment. It is recommended that departments performing HDR prostate brachytherapy verify catheter positions immediately prior to treatment delivery.

  16. Teilchendetektoren Grundlagen und Anwendungen

    CERN Document Server

    Kolanoski, Hermann

    2016-01-01

    In diesem Buch werden die experimentellen Grundlagen von Teilchendetektoren und ihre Anwendung in Experimenten beschrieben. Die Entwicklung von Detektoren ist ein wichtiger Bestandteil der Teilchen-, Astroteilchen- und Kernphysik und gehört daher zum Handwerk des Experimentalphysikers in diesen Gebieten. Dieses umfassende Werk beinhaltet den kompletten Stoff für entsprechende Master-Module in der experimentellen Teilchenphysik, geht aber im Inhalt auch darüber hinaus. Zielgruppe sind Studierende, die sich in die Materie vertiefen möchten, aber auch Lehrende und Wissenschaftler, die das Buch zum Einstieg in das wissenschaftliche Arbeiten an Detektorentwicklungen verwenden können. Zielrichtung des Buches ist, die physikalischen Grundlagen für die Detektoren und ihrer verschiedenen Ausführungen so klar wie möglich und so tiefgehend wie nötig darzustellen. Die Breite des für die Detektorentwicklung nötigen Wissens umfasst viele Bereiche der Physik und Technik, von den Wechselwirkun...

  17. Mediendidaktik und Wissensmanagement

    Directory of Open Access Journals (Sweden)

    Gabi Reinmann-Rothmeier

    2002-10-01

    Full Text Available Mediendidaktik und Wissensmanagement – das ist auf den ersten Blick ein ungleiches Paar: Die Mediendidaktik ist eine Teildisziplin der (Medien- Pädagogik, während Wissensmanagement ein genuin wirtschaftliches Thema mit betriebswirtschaftlichen Akzenten ist. Annäherungen zwischen der Mediendidaktik und Wissensmanagement gibt es zum einen durch den sog. E-Learning-Trend seitens der Wirtschaft, der mediendidaktisches Wissen und Können auf den Plan ruft, zum anderen durch wachsendes Interesse am Thema Wissensmanagement seitens der Pädagogik. Der Beitrag beschreibt sowohl für das E-Learning als auch für das Wissensmanagement aus pädagogisch-psychologischer Sicht jeweils ein Orientierungsmodell; beide Modelle machen die Berührungspunkte zwischen Mediendidaktik und Wissensmanagement deutlich. Neben einem Überblick über wirtschaftliche Argumente für eine Verschmelzung von E-Learning und Wissensmanagement werden aufbauend auf den beiden Orientierungsmodellen theoretische und praktische Verbindungslinien zwischen E-Learning und Wissensmanagement sowie die Rolle der Mediendidaktik in dem daraus entstehenden Wechselverhältnis herausgearbeitet.

  18. Image fusion of MRI and fMRI with intraoperative MRI data: methods and clinical relevance for neurosurgical interventions; Fusion von MRT-, fMRT- und intraoperativen MRT-Daten. Methode und klinische Bedeutung am Beispiel neurochirurgischer Interventionen

    Energy Technology Data Exchange (ETDEWEB)

    Moche, M.; Busse, H.; Dannenberg, C.; Schulz, T.; Schmidt, F.; Kahn, T. [Universitaetsklinikum Leipzig (Germany). Klinik und Poliklinik fuer Diagnostische Radiologie; Schmitgen, A. [GMD Forschungszentrum Informationstechnik GmbH-FIT, Sankt Augustin (Germany); Trantakis, C.; Winkler, D. [Klinik und Poliklinik fuer Neurochirurgie, Universitaetsklinikum Leipzig (Germany)

    2001-11-01

    mit Bilddatenfusion (rund 15-minuetiger Zusatzaufwand). Das erweiterte Navigationssystem zeichnet sich im Vergleich zur systemeigenen Navigation auf der Basis kontinuierlich akquirierbarer Real-time-Bilder durch eine schnellere Bildwiederholung und eine hoehere Bildqualitaet aus. Der Vergleich beider Navigationsbilder erlaubt das fruehzeitige Erkennen von Patienten-bzw. Gewebeverlagerungen. Die multimodale Bildfusion erlaubte eine differenziertere Navigationsplanung, insbesondere bei der Resektion tief liegender Hirntumoren oder bei Laesionen in enger Nachbarschaft zu eloquenten Arealen. Die erweiterte intraoperative Orientierung bzw. Instrumentenfuehrung erhoeht die Sicherheit und Genauigkeit neurochirurgischer Interventionen. (orig.)

  19. Lessing und der Islam

    OpenAIRE

    Muslim, Zahim Mohammed

    2010-01-01

    „Lessing und der Islam“ beschäftigt sich unparteiisch mit Lessings Auseinandersetzung mit dem Islam. Die Arbeit setzt sich das Ziel, den Leser und den Literaturkennern sowie der deutschen Bibliothek der Germanistik etwas von Lessings Auseinandersetzung mit dem Islam in die Hand zu geben, die bis heute als großes Modell für die interkulturelle und interreligiöse Menschheitstoleranzdebatte im Gedächtnis der deutschen Literatur vorhanden ist. Im ersten Teil widmet sich die vorliegende Arbeit de...

  20. Trauma und Terror

    OpenAIRE

    Szyszkowitz, T. (Tessa)

    2007-01-01

    1. Einleitung Ausgehend von der Fragestellung, warum gerade bei Tschetschenen und Palästinensern der Selbstmordterrorismus in den letzten Jahren so populär geworden ist, analysiert die Autorin die Geschichte dieser beiden Völker. Einer der Gründe ist bisher wenig beachtet worden. Der Einfluss eines kollektiven Traumas, das als solches nicht anerkannt, behandelt und auch nicht einer politischen Lösung zugeführt wurde. 2. Geschichte der Palästinenser und Tschetschenen Im Zuge der Err...

  1. A dosimetric selectivity intercomparison of HDR brachytherapy, IMRT and helical tomotherapy in prostate cancer radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Hermesse, Johanne; Biver, Sylvie; Jansen, Nicolas; Coucke, Philippe [Dept. of Radiation Oncology, Liege Univ. Hospital (Belgium); Lenaerts, Eric [Dept. of Medical Physics, Liege Univ. Hospital (Belgium); De Patoul, Nathalie; Vynckier, Stefaan [Dept. of Medical Physics, St Luc Univ. Hospital, Brussels (Belgium); Scalliet, Pierre [Dept. of Radiation Oncology, St Luc Univ. Hospital, Brussels (Belgium); Nickers, Philippe [Dept. of Radiation Oncology, Oscar Lambret Center, Lille (France)

    2009-11-15

    Background and purpose: dose escalation in order to improve the biochemical control in prostate cancer requires the application of irradiation techniques with high conformality. The dosimetric selectivity of three radiation modalities is compared: high-dose-rate brachytherapy (HDR-BT), intensity-modulated radiation radiotherapy (IMRT), and helical tomotherapy (HT). Patients and methods: ten patients with prostate adenocarcinoma treated by a 10-Gy HDR-BT boost after external-beam radiotherapy were investigated. For each patient, HDR-BT, IMRT and HT theoretical treatment plans were realized using common contour sets. A 10-Gy dose was prescribed to the planning target volume (PTV). The PTVs and critical organs' dose-volume histograms obtained were compared using Student's t-test. Results: HDR-BT delivers spontaneously higher mean doses to the PTV with smaller cold spots compared to IMRT and HT. 33% of the rectal volume received a mean HDR-BT dose of 3.86 {+-} 0.3 Gy in comparison with a mean IMRT dose of 6.57 {+-} 0.68 Gy and a mean HT dose of 5.58 {+-} 0.71 Gy (p < 0.0001). HDR-BT also enables to better spare the bladder. The hot spots inside the urethra are greater with HDR-BT. The volume of healthy tissue receiving 10% of the prescribed dose is reduced at least by a factor of 8 with HDR-BT (p < 0.0001). Conclusion: HDR-BT offers better conformality in comparison with HT and IMRT and reduces the volume of healthy tissue receiving a low dose. (orig.)

  2. Investigations of the boundary conditions of acicular ferrite formation in fast-quenched welded materials. Final report; Untersuchungen der Randbedingungen fuer die Bildung von 'acicular ferrite' in Schweissguetern bei schneller Abkuehlung. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Dilthey, U.; Biesenbach, M.

    2000-06-19

    The authors investigated the boundary conditions in which a fine-grained ferritic needle structure with sufficient low-temperature toughness is obtained in conditions of extreme heating and cooling. Alloy compositions and welding boundary conditions were investigated for laser welding, electron beam welding in a vacuum and electron beam welding at atmospheric pressure. [German] Im Rahmen dieser Arbeit soll untersucht werden, welche Randbedingungen erfuellt sein muessen, damit sich unter extremen Aufheiz- und Abkuehlbedingungen, wie sie bei den Strahlschweissverfahren vorliegen, ein feinkoerniges nadelferritisches Gefuege mit ausreichend hoher Tieftemperaturzaehigkeit bildet. Diesbezueglich ist fuer die Strahlschweissverfahren Laserstrahlschweissen, Elektronenstrahlschweissen im Vakuum und Elektronenstrahlschweissen unter Atmosphaerendruck zu ermitteln, welche Legierungszusammensetzungen diese Voraussetzungen erfuellen und wie sie unter realen Schweissbedingungen verwirklicht werden koennen. (orig.)

  3. Robust Estimation of HDR in fMRI using H-infinity Filters

    DEFF Research Database (Denmark)

    Puthusserypady, Sadasivan; Jue, R.; Ratnarajah, T.

    2010-01-01

    Estimation and detection of the hemodynamic response (HDR) are of great importance in functional MRI (fMRI) data analysis. In this paper, we propose the use of three H-infinity adaptive filters (finite memory, exponentially weighted, and timevarying) for accurate estimation and detection of the HDR......-1487]. Performances of the proposed techniques are compared to the conventional t-test method as well as the well-known LMSs and recursive least squares algorithms. Extensive numerical simulations show that the proposed methods result in better HDR estimations and activation detections....

  4. Relocation of a nucletron microselectron-HDR brachytherapy system

    Energy Technology Data Exchange (ETDEWEB)

    Bartrum, T; Tran, T; Freeman, N; Morales, J [St Vincents Hospital, Darlinghurst, NSW (Australia)

    2004-12-15

    Full text: For a period of four weeks, our clinical Nucletron microSelectron high dose rate (HDR) brachytherapy system was pulled out of clinical use and relocated to a new building. During this period decommission tests, de-wiring of the treatment unit and its associated safety system (such as radiation detector, emergency off circuits and door interlocks), transportation of all equipment, re-wiring of this equipment in the new location and recommission tests were carried out. The decommission and recommission test program was designed upon consultation with the manufacturer's (Nucletron) acceptance test procedures and work carried out by others. The ACPSEM tolerances for remote afterloaders was used as a guideline. In addition to mandatory dosimetry, positional, workstation database and safety tests, two Australian Standard compliance tests were carried out. The compliance tests involved one for remote afterloaders and another for treatment room design. This testing program was designed and implemented with the aim of ensuring ongoing safe delivery of brachytherapy doses to the patient. The testing program consisted of two parts. The first involved a series of decommissioning tests that consisted of dosimetry tests such as source and check cable positional accuracy and source calibration tests. In addition to these tests an inventory of standard plans, patient records and system configuration information was catalogued. The second part involved a series of recommission tests and involved carrying out dosimetry tests on the brachytherapy system (positional accuracy and calibration tests), simulating common treatment scenarios (prostate, cervical, vaginal and bile duct) and checking standard plans; patient records and system configuration had remained unchanged. During this period, other tests were carried out. These included Nucletron acceptance and preventative maintenance tests, Australian Standards compliance testing and integrity of network transfer of

  5. Relocation of a nucletron microselectron-HDR brachytherapy system

    International Nuclear Information System (INIS)

    Bartrum, T.; Tran, T.; Freeman, N.; Morales, J.

    2004-01-01

    Full text: For a period of four weeks, our clinical Nucletron microSelectron high dose rate (HDR) brachytherapy system was pulled out of clinical use and relocated to a new building. During this period decommission tests, de-wiring of the treatment unit and its associated safety system (such as radiation detector, emergency off circuits and door interlocks), transportation of all equipment, re-wiring of this equipment in the new location and recommission tests were carried out. The decommission and recommission test program was designed upon consultation with the manufacturer's (Nucletron) acceptance test procedures and work carried out by others. The ACPSEM tolerances for remote afterloaders was used as a guideline. In addition to mandatory dosimetry, positional, workstation database and safety tests, two Australian Standard compliance tests were carried out. The compliance tests involved one for remote afterloaders and another for treatment room design. This testing program was designed and implemented with the aim of ensuring ongoing safe delivery of brachytherapy doses to the patient. The testing program consisted of two parts. The first involved a series of decommissioning tests that consisted of dosimetry tests such as source and check cable positional accuracy and source calibration tests. In addition to these tests an inventory of standard plans, patient records and system configuration information was catalogued. The second part involved a series of recommission tests and involved carrying out dosimetry tests on the brachytherapy system (positional accuracy and calibration tests), simulating common treatment scenarios (prostate, cervical, vaginal and bile duct) and checking standard plans; patient records and system configuration had remained unchanged. During this period, other tests were carried out. These included Nucletron acceptance and preventative maintenance tests, Australian Standards compliance testing and integrity of network transfer of

  6. Commissioning and clinical implementation of HDR brachytherapy in El Salvador

    International Nuclear Information System (INIS)

    Morales Lopez, Jorge Luis; Castillo, Luis Frank; Castillo Bahi, Ramon del

    2009-01-01

    The Gynecologic Cancer is one of the best known malignancies in different countries of the world, with a high incidence in developing countries. In the treatment of this disease have been used multiple treatment arms among which is the high rate brachytherapy (HDR). The IAEA has put much emphasis on supporting all programs to treat this disease and in this context within the project 'Human Resource Development and Nuclear Technology Support', collaborated with the dispatch of experts on mission ELS0006 01 'Assistance to the ICES in HDR brachytherapy initiating Treatments at the Cancer Institute of El Salvador 'Dr. Narciso Diaz Bazan' in San Salvador, El Salvador. The process of commissioning and implementing clinical service Brachytherapy High Dose Rate (HDR BT) is a relatively complex process that begins with the formation of functional and technical service, based on flow patients to be treated, availability of local technological capability to install, and culminates with the preparation and implementation of protocols. Experts involved in the implementation of this service divided this task in stages organized chronologically: 1st. Study of existing infrastructure and level of training of technical personnel available, 2nd. Proposal and application of amendments in order to adapt the facility to the planned patient flow and optimal use of technological infrastructure, 3rd. Establishment of the process of securing the disposable waste materials and not required, 4th. Performance of tests of physical commissioning clinical dosimetry and instrumentation unit, surgical and therapeutic, 5th. Training of technical personnel, 6th. Preparation of clinical protocol and 7th. Initiation and development of treatment for patients. All these steps are carried out with the integration and consensus of the entire multidisciplinary team that makes up the service and with the support of the administration as a prerequisite. Within two weeks the service was modified according to

  7. Integration, Informationslogistik und Architektur

    OpenAIRE

    Turowski, Klaus

    2006-01-01

    Integration, Informationslogistik und Architektur : DW2006 ; 21./22.09.2006 in Friedrichshafen, Germany / Klaus Turowski ... (Hrsg.). - Bonn : Ges. für Informatik, 2006. - 490 S. - (GI-Edition / Proceedings ; 90)

  8. Supraleitung Grundlagen und Anwendungen

    CERN Document Server

    Buckel, Werner

    2004-01-01

    Seit nunmehr drei Jahrzehnten ist der "Buckel" das Referenzwerk in deutscher Sprache zum Thema Supraleitung. Immer wieder aktualisiert, hat das Lehrbuch Generationen von Studenten begleitet. In der 6., vollständig überarbeiteten Auflage wird das bewährte didaktische Konzept beibehalten, inhaltlich wurde der Band dem aktuellen Stand von Forschung und Technik angepasst. Das Autorenteam um Prof. Kleiner verzichtet auf komplizierte mathematische Herleitungen. Es baut ganz auf das bewährte Step-by-Step-Prinzip: Der Schwierigkeitsgrad wird von Kapitel zu Kapitel gesteigert. So können auch Einsteiger ohne einschlägige Vorkenntnisse dem Stoff bequem folgen. Dank seiner klaren Sprache und zahlreicher Abbildungen eignet sich der Band hervorragend als einführendes Lehrbuch - und zwar nicht nur für Physik-Studenten, sondern auch für Studierende angrenzender Natur- und Ingenieurwissenschaften. Grundlegende Eigenschaften, supraleitende Elemente, Cooper-Paarung, Thermodynamik, kritische Ströme, Josephsonkontakte...

  9. Ausbildung und Erwartungshaltung

    Science.gov (United States)

    Knoke, Holger

    1997-09-01

    werden Geologiestudenten zeitgemäß ausgebildet? Wird in der Angewandten Geologie das gelehrt, was in Wirtschaftsunternehmen an Wissen von einem Geologen erwartet wird? Erfolgt die spezielle Ausbildung zum Hydrogeologen fundiert und umfassend? Eine Antwort auf diese Fragen kann sicherlich nicht allumfassend gegeben werden, da sie von der jeweiligen Sichtweise abhängig ist. Ein Geologieprofessor wird die Ausbildung seiner Studenten im Großen und Ganzen als zeitgemäß einstufen, eventuell hier und da Verbesserungen für möglich halten. Auffällig ist die hohe Anzahl der in den letzten Jahren bereits geänderten oder zur Änderung anstehenden Studienordnungen. Es zeigt, daß die Straffung des Studiums sowie eine zumindest teilweise neue Wichtung der Schwerpunkte notwendig war bzw. ist, wobei im allgemeinen eine höhere Stundenzahl in den Grundlagenfächern Mathematik, Physik und Chemie angesetzt wird. Betrachtet man die Gesamtstundenzahlen der alten und der reformierten Studienordnungen, kann jedoch von einer Kürzung der Pflichtstunden in den meisten Fällen nicht die Rede sein. Eine grundlegende Reform des Geologiestudiums ist zur Zeit nicht zu erkennen, eher eine Verschulung des Studienganges. Die Entwicklung scheint zur Zeit weg von der freien Kurswahl und hin zu Modulangeboten mit vorgegebenen Kursen und Reihenfolgen zu gehen. Für die Hydrogeologie-Professoren ist es sicherlich nicht einfach zu entscheiden und in ihrem Kollegenkreis durchzusetzen, was aus dem generellen geowissenschaftlichen Kursangebot für einen Hydrogeologen notwendig oder aber entbehrlich ist. Genügen die Grundlagen der Paläontologie und der Mineralogie? Kann man ganz darauf verzichten? Was erwarten Behörden und Wirtschaftsunternehmen an allgemeinen und Spezialkenntnissen? Geologische Landesämter z. B. wollen, pauschal betrachtet, Geologen alten Stils. Ist ausdrücklich ein Angewandter Geologe oder speziell ein Hydrogeologe erwünscht, soll dieser die Spezialkenntnisse zus

  10. Nationale und transnationale Vernetzung polnischer Städte und Regionen: Auf dem Weg zu einer nachhaltigen Stadt- und Regionalentwicklung

    OpenAIRE

    Dorsch, Pamela

    2003-01-01

    "Die Studie 'Nationale und transnationale Vernetzung polnischer Städte und Regionen - Bedeutung für eine nachhaltige Stadt- und Regionalentwicklung' liefert einen Überblick über die Einbindung polnischer Kommunen und Wojewodschaften in allgemeine und politikfeldspezifische Netzwerke auf nationaler und transnationaler Ebene. Besondere Berücksichtigung findet hierbei die Vernetzung in Fragen von Nachhaltigkeit und des Umweltschutzes. Einführend zeigt die Studie den Prozess zunehmender Dezentral...

  11. Quality assurance of Vari-source high dose rate (HDR) brachytherapy- remote after loader and cost effectiveness of Vari-source HDR- brachytherapy: NORI, Islamabad experience

    International Nuclear Information System (INIS)

    Ahmad, N.; Mahmood, H.; Jafri, S.R.A.

    2004-01-01

    A quality control of Vari-Source high dose rate (HDR) remote after loading brachytherapy machine was carried out and the cost effectiveness of HDR brachytherapy machine was also evaluated considering the cost of ten Iridium-192 wire sources at Nuclear Medicine, Oncology and Radiotherapy Institute (NORI), Islamabad, Pakistan. A total number of 253 intracavitary insertions were done in 98 patients from October 1996 to May 2001. The results of the quality control tests performed during 1996 to 2001 were within the acceptable limits. The cost effectiveness of Vari-Source HDR brachytherapy machine was also evaluated. The average cost per patient was calculated as US$ 491. Small number of patients was treated as the machine was used for gynecologic malignancies only. The objective was to assess the quality control status of HDR brachytherapy machine on patient treatment day, source exchange day and periodic day (monthly basis). It was found that the cost per patient can be minimized if other type of cancer patients are also treated on Vari-Source HDR machine. (author)

  12. Zwischen Freakout und Normcore

    Directory of Open Access Journals (Sweden)

    Beate Großegger

    2017-06-01

    Full Text Available Bis Ende des 20. Jahrhunderts war Rebellion jugendkulturell ein großes Thema. Heute hat die Jugend das so genannte Establishment aus den Augen verloren; die breite Mehrheit gibt sich postheroisch, setzt auf individualitätsbezogene Werte und träumt, eingeschlossen in ihre bunten Lifestyleblasen, von einem perfekten Leben. Bezugnehmend auf aktuelle Befunde der Jugend- und Generationenforschung gibt Beate Großegger in ihrem Beitrag einen Überblick über die wichtigsten Werte- und Lifestyletrends im frühen 21. Jahrhundert und zeigt dabei, wie sehr die heutige Jugend Kind ihrer Zeit und Produkt gesellschaftlicher Rahmenbedingungen ist. Until the late 20th century rebellion was an important aspect of various youth subcultures. But today’s youth has a different mindset. The majority acts post-heroically, i.e. they rather focus on their individual, their private lifestyle than opposing against the establishment. Wrapped in their lifestyle filterbubbles, they dream of a perfect life. Based on recent youth und generation studies Beate Großegger gives an overview of the most important youth cultural trends in the fields of values and lifestyles and introduces today’s youth as a child of our times.

  13. HDR flood-water storage-tank modal vibration tests

    International Nuclear Information System (INIS)

    Gorman, V.W.; Thinnes, G.L.

    1983-01-01

    Modal vibration tests were conducted by EG and G Idaho on two vessels located at West Germany's Heissdampfreaktor (HDR) facility which is 25 kilometers east of Frankfurt. The tests were performed during May and June 1982 for the US Nuclear Regulatory Commission (NRC) as part of their cooperative effort with Kernforschungszentrum Karlsruhe (KfK) of West Germany. The primary purpose for performing this task was to determine modal properties (frequencies, mode shapes and associated damping ratios) in order to eventually provide guidelines for standards development by the NRC in modeling similar vessels. One of the vessels tested was a flood water storage tank (FWST) for empty, half full and full water conditions. The FWST was excited randomly with an electromagnetic shaker and by impulsive hammer blows. Excitation or input forces together with measured vessel responses were processed by a digital modal analyzer and stored on magnetic disks for subsequent evaluation

  14. Remote Afterloading High Dose Rate (HDR) Endobronchial Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Hyesook; Choi, Eun Kyung; Yi, Byong Yong; Kim, Won Dong; Kim, Woo Sung; Koh, Youn Suck [Ulsan University College of Medicine, Seoul (Korea, Republic of)

    1991-12-15

    Authors described the remote afterloading endobronchial brachytherapy (EBBT) technique using the microSelectron HDR Ir-192 and the Asan Medical Center experience. Total 28 EBBT in 9 patients were performed since November 1989 and 24 EBBT in 8 patients were employed for palliation and 3 EBBT in 1 patient was treated curatively. Authors observed a significant relief of obstructive symptom with tumor regression in 7 patients out of 8 who were treated palliatively but one of them died of pulmonary congestion in 3 weeks after EBBT. One patient with prior therapy of extensive electrocautery expired within 1 day after 2nd EBBT procedure with massive hemorrhage from the lesion. EBBT procedure has been tolerable and can be performed as an outpatient.

  15. Remote Afterloading High Dose Rate (HDR) Endobronchial Brachytherapy

    International Nuclear Information System (INIS)

    Chang, Hyesook; Choi, Eun Kyung; Yi, Byong Yong; Kim, Won Dong; Kim, Woo Sung; Koh, Youn Suck

    1991-01-01

    Authors described the remote afterloading endobronchial brachytherapy (EBBT) technique using the microSelectron HDR Ir-192 and the Asan Medical Center experience. Total 28 EBBT in 9 patients were performed since November 1989 and 24 EBBT in 8 patients were employed for palliation and 3 EBBT in 1 patient was treated curatively. Authors observed a significant relief of obstructive symptom with tumor regression in 7 patients out of 8 who were treated palliatively but one of them died of pulmonary congestion in 3 weeks after EBBT. One patient with prior therapy of extensive electrocautery expired within 1 day after 2nd EBBT procedure with massive hemorrhage from the lesion. EBBT procedure has been tolerable and can be performed as an outpatient

  16. 192Ir high dose rate (HDR) interstitial brain implant: optimisation

    International Nuclear Information System (INIS)

    Tyagi, Anuj; Singh, Dinesh; Chitra, S.; Gupta, J.P.

    2001-01-01

    The new modality of stepping source dosimetry system (SSDs) illustrates a remarkable improvement in attaining the uniform and homogeneous dose distribution within the target volume. The technique enables the physicist to correct for a certain amount of misplacement or curvature of implant geometry. The short course of brachytherapy provides good palliation in terms of functional improvements with low and acceptable toxicity in high-grade glioma. With continual refinements of the technique, brachytherapy performed by a skilled brachytherapy team offers an opportunity to improve patient survival and quality of life. Since 1997, micro selectron HDR 192 Ir treatments are done including gynecological, oesophageal, breast, surface mould, soft tissue sarcoma (STS) and brain in our hospital. In this paper, procedure of interstitial brain implant in glioma as implant technique, simulation and treatment planning will be discussed

  17. Hybridization and control of a mobile direct methanol fuel cell system; Hybridisierung und Regelung eines mobilen Direktmethanol-Brennstoffzellen-Systems

    Energy Technology Data Exchange (ETDEWEB)

    Wilhelm, Joerg Christoph

    2010-07-01

    for the dimensioning of the fuel cell as well as of the energy storage unit. Variation of parameters results in a minimum required fuel cell power of 1.3 kW as well as a minimum energy density of 66 Wh/l or a minimum power density of 355 W/l for the energy storage unit, respectively. The high energy density required and the fact that the energy storage unit must always be operated at a partial state of charge leads to faster aging, particularly of lead-acid batteries, so that a lithium battery is eventually chosen as an energy storage unit. (orig.) [German] Direktmethanol-Brennstoffzellen (DMFCs) zeichnen sich dadurch aus, dass sie die chemische Energie des fluessig zugefuehrten Brennstoffs Methanol direkt in elektrische Energie umwandeln. Methanol hat eine hohe Energiedichte und laesst sich vergleichsweise einfach speichern. Aufgrund dieser Vorteile eignen sich Direktmethanol-Brennstoffzellen- Systeme z. B. als Batterieersatz fuer den Bereich leichte Traktion in der kW-Klasse. Da das Nachtanken im Vergleich zum Laden einer Batterie viel schneller realisierbar ist, folgt hieraus ein nahezu unterbrechungsfreier Betrieb. Das Ziel der vorliegenden Arbeit ist es daher ein Direktmethanol-Brennstoffzellen-System fuer den Bereich leichte Traktion zu entwickeln. Die systemtechnische Entwicklung und Charakterisierung eines mobilen Direktmethanol-Brennstoffzellen-Systems erfolgt zuerst allgemein und anschliessend angewandt auf das Beispiel Horizontalkommissionierer aus der Klasse der Flurfoerderfahrzeuge. Hierfuer soll sowohl ein Hybridisierungs- als auch ein Regelungskonzept entwickelt werden. Die gewaehlte Vorgehensweise gliedert sich in die Charakterisierung der Anwendung, die theoretische Konzeptentwicklung und eine abschliessende Systemanalyse mithilfe von Untersuchungen am Teststand und Simulationen. Aus der Charakterisierung folgt der charakteristische Fahrzyklus der Anwendung. Die Eckdaten, wie maximale Peakleistungen beim Beschleunigen und Bremsen sowie die

  18. Neue Laser und Strahlquellen - alte und neue Risiken?

    DEFF Research Database (Denmark)

    Paasch, Uwe; Schwandt, Antje; Seeber, Nikolaus

    2017-01-01

    Die Entwicklungen im Bereich dermatologischer Laser, hochenergetischer Blitzlampen, LED und neuer Energie- und Strahlquellen der letzten Jahre haben gezeigt, dass mit neuen Wellenlängen, Konzepten und Kombinationen zusätzliche, zum Teil über den ästhetischen Bereich hinaus gehende therapeutische ...

  19. Führung und Machiavellismus

    NARCIS (Netherlands)

    Belschak, F.D.; den Hartog, D.N.; Felfe, J.

    2015-01-01

    In diesem Beitrag wird der Zusammenhang zwischen Führung und Machiavellismus aus zwei verschiedenen Perspektiven betrachtet. Zum einen werden neuere Forschungsergebnisse referiert, wie machiavellistische Mitarbeiter auf verschiedene Führungsstile ihres Vorgestzten reagieren und so mit Hinblick auf

  20. Netzformen und VDE-Bestimmungen

    Science.gov (United States)

    Bernstein, Herbert

    Der Verband Deutscher Elektrotechniker (VDE) hat eine Reihe von Vorschriften ausgearbeitet, die dem Schutz von Leben und Sachen beim Umgang mit elektrischer Energie dienen. Besonders wichtig sind die in den VDE-Bestimmungen 0100 und 0411 festgelegten Vorschriften.

  1. Delegation und Kooperation im Gesundheitswesen

    OpenAIRE

    Rosenau, Henning

    2010-01-01

    Delegation und Kooperation im Gesundheitswesen. - In: Tıpta işbirliği ve hukuksal sorunlar = Delegation und Kooperation im Gesundheitswesen / ed.: Hakan Hakeri ... - Samsun : Adalet, 2010. - S. 7-18

  2. Risiko Video- und Computerspiele? Eine Studie über Video- und Computerspielnutzung und Aggression bei 12- und 16- jährigen Jugendlichen

    OpenAIRE

    Schiller, Eva-Maria; Strohmeier, Dagmar; Spiel, Christiane

    2009-01-01

    Video -und Computerspielen ist heutzutage eine beliebte Freizeitaktivität von Kindern und Jugendlichen, besonders von Jungen. Trotz der großen Vielfalt der angebotenen Video- und Computerspiele für Kinder und Jugendliche, konzentriert sich die Forschung vorwiegend auf negative Einflüsse von gewalthaltigen Video- und Computerspielen. Da nicht alle Kinder und Jugendliche ausschließlich gewalthaltige Video- und Computerspiele spielen, betrachten wir diesen Fokus in der Wissenschaft als zu eng ge...

  3. Transition from LDR to HDR brachytherapy for cervical cancer: Evaluation of tumor control, survival, and toxicity.

    Science.gov (United States)

    Romano, K D; Pugh, K J; Trifiletti, D M; Libby, B; Showalter, T N

    In 2012, our institution transitioned from low-dose-rate (LDR) brachytherapy to high dose-rate (HDR) brachytherapy. We report clinical outcomes after brachytherapy for cervical cancer at our institution over a continuous 10-year period. From 2004 to 2014, 258 women (184 LDR and 74 HDR) were treated with tandem and ovoid brachytherapy in the multidisciplinary management of International Federation of Gynecology and Obstetrics Stages IA-IVB cervical cancer. Clinical and treatment-related prognostic factors including age, stage, smoking status, relevant doses, and toxicity data were recorded. Median followup for the LDR and HDR groups was 46 months and 12 months, respectively. The majority of patients (92%) received external beam radiotherapy as well as concurrent chemotherapy (83%) before the start of brachytherapy. For all stages, the 1-year local control and overall survival (OS) rates were comparable between the LDR and HDR groups (87% vs. 81%, p = 0.12; and 75% vs. 85%, p = 0.16), respectively. Factors associated with OS on multivariate analysis include age, stage, and nodal involvement. On multivariate analysis, severe toxicity (acute or chronic) was higher with HDR than LDR (24% vs. 10%, p = 0.04). Additional prognostic factors associated with increased severe toxicity include former/current smokers and total dose to lymph nodes. This comparative retrospective analysis of a large cohort of women treated with brachytherapy demonstrates no significant difference in OS or local control between the LDR and HDR. Acute and chronic toxicity increased shortly after the implementation of HDR, highlighting the importance of continued refinement of HDR methods, including integrating advanced imaging. Copyright © 2016 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  4. Evaluation and development of soil values for the pathway 'soil to plant'. Transfer factors soil to plant; Ueberpruefung und Fortentwicklung der Bodenwerte fuer den Boden-Pflanze-Pfad. Teilbericht 1: Transferfaktoren Boden-Pflanze

    Energy Technology Data Exchange (ETDEWEB)

    Trapp, S.; Matthies, M.; Reiter, B.; Gaeth, S.

    2001-10-01

    . Aufnahme aus der Bodenloesung und Translokation mit den Pflanzensaeften spielt - ausser fuer Phenanthren - kaum eine Rolle. Bei den untersuchten Moehren und Kartoffeln ist vorwiegend die Schale kontaminiert. Die Transferfaktoren der PCB sind durchweg hoeher als die der PAK. Es wird vermutet, dass dafuer der photolytische Abbau von PAK auf Blattoberflaechen verantwortlich ist. Des Weiteren gibt es Hinweise darauf, dass die Metabolisierung von PAK in Pflanzen schneller ablaeuft als die der PCB. (orig.)

  5. Ellbogen- und Handgelenksendoprothetik beim Rheumatiker - Richtlinien und Rehabilitation

    Directory of Open Access Journals (Sweden)

    Chochole M

    2008-01-01

    Full Text Available Die Endoprothetik an Ellbogen und Handgelenk ist seit etwa drei Jahrzehnten etabliert. An beiden Gelenken haben sich einzelne Implantate oder Designs durchgesetzt. Operationstechniken und Nachuntersuchungsergebnisse sind publiziert. Wenig ist jedoch zum Thema Nachbehandlung und Nachsorge veröffentlicht. Diese Arbeit beschäftigt sich detailliert mit der ärztlichen und therapeutischen Betreuung nach Implantation einer Ellbogen- oder Handgelenksendoprothese beim Patienten mit rheumatischer Arthritis unter Aufgliederung in Krankenhausaufenthalt, ambulanter Nachsorge sowie stationärer Rehabilitation. Dabei werden Zeitrahmen, Therapieziele und Behandlungen gesondert angeführt.

  6. Cost modelling of electricity producing hot dry rock (HDR) geothermal systems in the UK

    International Nuclear Information System (INIS)

    Doherty, P.S.

    1992-03-01

    A detailed and comprehensive cost model for Hot Dry Rock (HDR) electricity producing systems has been developed in this study. The model takes account of the major aspects of the HDR system, parameterized in terms of the main physical and cost parameters of the resource and the utilization system. A doublet configuration is assumed, and the conceptual HDR system which is defined in the study is based upon the UK Department of Energy (DEn) HDR geothermal R and D programme. The model has been used to calculate the costs of HDR electricity for a UK defined base case which represents a consensus view of what might be achieved in Cornwall in the long term. At 14.2 p/kWh (1988 costs) this cost appears to be unacceptably high. A wide-ranging sensitivity study has also been carried out on the main resource, geometrical, and operational parameters of the HDR system centred around the UK base case. The sensitivity study shows the most important parameters to be thermal gradient and depth. (Author)

  7. Altautoverwertung zwischen Staat und Markt: Bedingungen und Potentiale zur Modernisierung von Lagerhaltung und Marketing gebrauchter Autoteile

    OpenAIRE

    Lucas, Rainer

    2000-01-01

    Das Arbeitspapier diskutiert vor dem Hintergrund veränderter gesetzlicher Rahmen-und Wettbewerbsbedingungen in der Autoverwertung Ziele und Maßnahmen zurStärkung kleiner und mittelständischer Verwertungsbetriebe. Der Bereich GebrauchteAutoteile wird im Rahmen eines regionalen Fallbeispiels einer tiefergehenden Analyseunterzogen. Hieraus werden Vorschläge zur regionalen Netzwerkbildung innerhalb derBranche und neue Dienstleistungsperspektiven abgeleitet. Ein wesentliches Koope-rationsfeld ist ...

  8. Rosetta und Yella

    Directory of Open Access Journals (Sweden)

    Urs Urban

    2009-11-01

    Full Text Available L’apparition de l’homo oeconomicus marque la fin des grands récits et par là de l’ensemble social que ceux-ci avaient légitimé. En même temps cependant il entre dans les récits littéraires – et filmiques, par exemple dans Rosetta (1999 des frères Dardenne et Yella (2007 de Christian Petzold. L’article se propose de montrer comment ces derniers réussissent à mettre en scène les apories existentielles d’un sujet produit par le dispositif économique en appliquant des procédés narratifs permettant de problématiser la narration elle-même.Mit dem Auftauchen des homo oeconomicus scheint das Ende der großen Erzählungen und des von diesen legitimierten sozialen Zusammenhangs besiegelt. Genau in diesem Moment indes beginnen sich die kleinen, die literarischen und filmischen Erzählformen für den ökonomischen Menschen zu interessieren. In dem Artikel geht es darum zu zeigen, wie die Brüder Dardenne und Christian Petzold die Aporien eines vom ökonomischen Dispositiv produzierten Subjekts in ihren Filmen Rosetta (1999 und Yella (2007 erzählerisch umsetzen und dabei genau diese erzählerische Umsetzbarkeit in Frage stellen.

  9. Supraleitung Grundlagen und Anwendungen

    CERN Document Server

    Buckel, Werner

    2013-01-01

    Grundlegende Konzepte und Eigenschaften von Supraleitern, die Herstellung und Entwicklung von neuen supraleitenden Materialien sowie moderne Anwendungsbereiche sind die Schwerpunktthemen des Buches. Das größte Potential zur Nutzung der Supraleitung liegt in der Energietechnik. Fast unbemerkt trägt die Einführung von Kabeln, Magneten, Transformatoren oder Lagern aus supraleitenden Materialien bei zur Effizienzsteigerung bei der Stromübertragung oder in Motoren. Durch seiner klare Sprache und zahlreiche erläuternde Abbildungen eignet sich der Band hervorragend als einführendes Lehrbuch. Der Schwierigkeitsgrad wird von Kapitel zu Kapitel gesteigert. So können auch Einsteiger ohne einschlägige Vorkenntnisse dem Stoff folgen. Dank der über 350 Literaturhinweise bekommt der Leser außerdem einen Überblick über die wichtigsten Publikationen zum Thema. Ein unverzichtbares Lehrbuch also für Physik-Studenten und Studierende der Ingenieurwissenschaften. Fachleuten in Forschung und Praxis leistet das Buch au...

  10. Schneller befördert werden

    DEFF Research Database (Denmark)

    Claussen, Jörg; Grohsjean, Thorsten; Luger, Johannes

    2015-01-01

    Karriere: Manager, die in ihrem Unternehmen aufsteigen wollen, stehen häufig vor einem Dilemma: Einerseits sollen sie Teamspieler sein, andererseits aus der Masse hervorstechen. Eine Studie zeigt, wie sich dieser Widerspruch auflösen lässt....

  11. The relative efficacy of HDR and LDR interstitial brachytherapy in squamous cell carcinoma of vagina

    International Nuclear Information System (INIS)

    Demanes, D. J.; Hsu, I-C.; Lin, S.; Ewing, T.; Rodriguez, R.

    1996-01-01

    Introduction: Beginning in 1982 we performed low dose rate (LDR) interstitial template brachytherapy (ISTB) for carcinoma of the vagina. High dose rate (HDR) remote afterloading has been used exclusively since 1991. We compare the results LDR and HDR brachytherapy. Material and Methods: Between 1982 and 1994, 30 patients with primary squamous cell carcinoma of vagina received external beam radiotherapy (EBRT) and brachytherapy. The AJCC stage distribution was 3 stage I, 25 stage II, and 2 stage III. The average central pelvic EBRT dose was 35 Gy. Pelvic side wall EBRT doses ranged from 45 to 50.4 Gy. Nineteen patients had LDR treatment; 3 intracavitary brachytherapy (ICB) and 16 ISTB. Eleven patients had HDR treatment; 2 ICB and 9 ISB. The average dose delivered by LDR was 41.2 Gy usually in 2 fractions, and by HDR 32.5 Gy in 6 fractions of 500-550 cGy. Local failures were confirmed pathologically. The absolute survival (AS) and relapse-free survival (RFS) were calculated using Kaplan-Meier method and compared with logrank statistics. Results: The mean follow-up was 77 months for LDR and 23 months for HDR. Local and regional control was achieved in 90% (27/30) of the patients. Three year AS was 84% and RFS was 87%. There was no significant difference between LDR and HDR in AS, RFS or local-regional control, (log rank p=0.85, p=0.12 and p=0.35 respectively). The single HDR local failure presented in a patient with extensive stage II disease who declined ISTB. There were fewer complications following HDR. The 1 case of extensive vaginal necrosis and the 3 cases of rectovaginal fistula that required surgery occurred only with LDR brachytherapy. Discussion: Excellent local and regional control of carcinoma of the vagina can be achieved by administering limited doses of external radiation and brachytherapy. Interstitial template implants are the best means of encompassing paravaginal disease while sparing the adjacent uninvolved normal tissues from high doses of

  12. Der Nahostkonflikt und die Medien

    Directory of Open Access Journals (Sweden)

    Carola Richter

    2014-06-01

    Full Text Available Diese Einführung in eine Themenausgabe zu den vielfältigen Rollen der Medien im Nahostkonflikt skizziert die Probleme, die sich für Medien und Journalisten als Akteure im Konflikt, Adressaten der Konfliktparteien und Anlass für Konflikt durch ihre Berichterstattung ergeben. Das Konfliktgebiet Israel und Palästina ist sowohl für Forschung über Auslandsbericht-erstattung, über transnationale Agenda Building- und Public Diplomacy-Prozesse als auch über mediensystemische Entwicklungen in Besatzer- und Besatzungsgebieten interessant. Der Artikel gibt einen Überblick über das Feld und führt dabei in die in der Themenausgabe präsentierten empirischen Studien zum Nahostkonflikt und den Medien ein.

  13. Die biene und ihre produkte in der kunst und im alltagsleben (Fruhchristliche und byzantinische Zeit

    Directory of Open Access Journals (Sweden)

    Liveri Angeliki

    2010-01-01

    Full Text Available Die vorliegende Arbeit ist in zwei Teile geteilt: den kunst- und kulturhistorischen Teil. Im ersten Teil werden Darstellungen uber Bienen Bienenzucht, Honig und Wachs seit der fruhchristlichen bis zur spatbyzantinischen Zeit vorgefuhrt. Daher ist es als Beitrag in der "Ikonographie" der Biene wahrend dieser Zeit zu verstehen. Im kulturhistorischen Teil werden Informationen uber die Bienenzucht, den Handel mit Honig und Wachs sowie ihre vielfaltige Anwendung von der byzantinischen Gesellschaft an Hand der primaren Quellen, des Standes der Forschung und der archaologischen Funden erwahnt. Damit ist erwunscht ein moglichst gutes Bild der byzantinischen Bienenzucht wieder zu geben und die Nutzung der Bienenprodukte in Byzanz anschaulich zu machen.

  14. Digitalisierung und Selbstbestimmung

    Directory of Open Access Journals (Sweden)

    Eisenberger, Iris

    2017-12-01

    Full Text Available Kurztext: Der Beitrag beleuchtet das Verhältnis von Digitalisierung und Recht. Am Beispiel der Blockchain-Technologie wird aufgezeigt, wie neue Formen und Räume der Selbstbestimmung geschaffen werden können. In distribuierten Systemen ist die Tendenz erkennbar, dass sich die rechtliche hin zu einer technologischen Steuerung verlagert. Wenn Funktionen, die für gewöhnlich der demokratisch legitimierte Gesetzgeber wahrnimmt, auf andere Systeme übergehen, führt dies zu Herausforderungen für rechtsstaatliche Demokratien. Fundamentale Fragen von Kontrolle und Machtbeschränkung iZm Digitalisierung stehen im Fokus. Der Beitrag plädiert schließlich für „legal foresight“-Forschung im Bereich neuer Technologien.

  15. Comparison of radiation shielding requirements for HDR brachytherapy using 169Yb and 192Ir sources

    International Nuclear Information System (INIS)

    Lymperopoulou, G.; Papagiannis, P.; Sakelliou, L.; Georgiou, E.; Hourdakis, C. J.; Baltas, D.

    2006-01-01

    169 Yb has received a renewed focus lately as an alternative to 192 Ir sources for high dose rate (HDR) brachytherapy. Following the results of a recent work by our group which proved 169 Yb to be a good candidate for HDR prostate brachytherapy, this work seeks to quantify the radiation shielding requirements for 169 Yb HDR brachytherapy applications in comparison to the corresponding requirements for the current 192 Ir HDR brachytherapy standard. Monte Carlo simulation (MC) is used to obtain 169 Yb and 192 Ir broad beam transmission data through lead and concrete. Results are fitted to an analytical equation which can be used to readily calculate the barrier thickness required to achieve a given dose rate reduction. Shielding requirements for a HDR brachytherapy treatment room facility are presented as a function of distance, occupancy, dose limit, and facility workload, using analytical calculations for both 169 Yb and 192 Ir HDR sources. The barrier thickness required for 169 Yb is lower than that for 192 Ir by a factor of 4-5 for lead and 1.5-2 for concrete. Regarding 169 Yb HDR brachytherapy applications, the lead shielding requirements do not exceed 15 mm, even in highly conservative case scenarios. This allows for the construction of a lead door in most cases, thus avoiding the construction of a space consuming, specially designed maze. The effects of source structure, attenuation by the patient, and scatter conditions within an actual treatment room on the above-noted findings are also discussed using corresponding MC simulation results

  16. Preliminary results of study comparing HDR with LDR brachytherapy for IIIb cervical cancer

    International Nuclear Information System (INIS)

    Trippe, N.; Pellizzon, A.C.A.; Novaes, P.; Salvajoli, J.V.; Fogaroli, R.; Maia, M.A.C.; Baraldi, H.; Ferrigno, R.

    1996-01-01

    Since 1992 we have been using a Micro-Selectron HDR device, working with Iridium 192 to treat the cervical cancer and some others pathologies. With a minimum follow up of 24 months, 59 patients with cervical cancer were randomizated for one of the following schedule of treatment: EBRT - 45Gy - fx 1,8Gy plus Brachytherapy 1-HDR - 36 (61%) - 4 weekly insertions of 6,0Gy at point A 2-LDR - 29 (39%) - two insertions fifteen days apart of 17,5Gy at point A EBRT was performed with a Linac 4MV, in box arrangement and parametrial complementation of dose with AP-PA fields. For Brachytherapy Fletcher Colpostats are used in association with intrauterine tamdens, in both arms. Brachyterapy starts in HDR group after ten days of the beginning of the treatment. The total time of treatment is shortened here in two weeks. LDR brachytherapy starts only after the end of EBRT. Results - local control was 61% in 12 months and 50% in 24 months for HDR group, versus 52,6% and 47,8% for LDR group. Local failures of 39% and 50% in 12 and 24 months for HDR and 47,8% and 52,8% for LDR groups respectively. Complications were restricted to rectites and cistites - 8,3% for HDR and 13% for LDR. Conclusions - HDR brachytherapy has an equivalent local control when compared to LDR, can treat a larger number of patients in a shorter period, has possibilities of dose optimizations and decrease the radiation exposure to the staff

  17. MR-based source localization for MR-guided HDR brachytherapy

    Science.gov (United States)

    Beld, E.; Moerland, M. A.; Zijlstra, F.; Viergever, M. A.; Lagendijk, J. J. W.; Seevinck, P. R.

    2018-04-01

    For the purpose of MR-guided high-dose-rate (HDR) brachytherapy, a method for real-time localization of an HDR brachytherapy source was developed, which requires high spatial and temporal resolutions. MR-based localization of an HDR source serves two main aims. First, it enables real-time treatment verification by determination of the HDR source positions during treatment. Second, when using a dummy source, MR-based source localization provides an automatic detection of the source dwell positions after catheter insertion, allowing elimination of the catheter reconstruction procedure. Localization of the HDR source was conducted by simulation of the MR artifacts, followed by a phase correlation localization algorithm applied to the MR images and the simulated images, to determine the position of the HDR source in the MR images. To increase the temporal resolution of the MR acquisition, the spatial resolution was decreased, and a subpixel localization operation was introduced. Furthermore, parallel imaging (sensitivity encoding) was applied to further decrease the MR scan time. The localization method was validated by a comparison with CT, and the accuracy and precision were investigated. The results demonstrated that the described method could be used to determine the HDR source position with a high accuracy (0.4–0.6 mm) and a high precision (⩽0.1 mm), at high temporal resolutions (0.15–1.2 s per slice). This would enable real-time treatment verification as well as an automatic detection of the source dwell positions.

  18. SU-F-BRA-04: Prostate HDR Brachytherapy with Multichannel Robotic System

    International Nuclear Information System (INIS)

    Joseph, F Maria; Podder, T; Yu, Y

    2015-01-01

    Purpose: High-dose-rate (HDR) brachytherapy is gradually becoming popular in treating patients with prostate cancers. However, placement of the HDR needles at desired locations into the patient is challenging. Application of robotic system may improve the accuracy of the clinical procedure. This experimental study is to evaluate the feasibility of using a multichannel robotic system for prostate HDR brachytherapy. Methods: In this experimental study, the robotic system employed was a 6-DOF Multichannel Image-guided Robotic Assistant for Brachytherapy (MIRAB), which was designed and fabricated for prostate seed implantation. The MIRAB has the provision of rotating 16 needles while inserting them. Ten prostate HDR brachytherapy needles were simultaneously inserted using MIRAB into a commercially available prostate phantom. After inserting the needles into the prostate phantom at desired locations, 2mm thick CT slices were obtained for dosimetric planning. HDR plan was generated using Oncetra planning system with a total prescription dose of 34Gy in 4 fractions. Plan quality was evaluated considering dose coverage to prostate and planning target volume (PTV), with 3mm margin around prostate, as well as the dose limit to the organs at risk (OARs) following the American Brachytherapy Society (ABS) guidelines. Results: From the CT scan, it is observed that the needles were inserted straight into the desired locations and they were adequately spaced and distributed for a clinically acceptable HDR plan. Coverage to PTV and prostate were about 91% (V100= 91%) and 96% (V100=96%), respectively. Dose to 1cc of urethra, rectum, and bladder were within the ABS specified limits. Conclusion: The MIRAB was able to insert multiple needles simultaneously into the prostate precisely. By controlling the MIRAB to insert all the ten utilized needles into the prostate phantom, we could achieve the robotic HDR brachytherapy successfully. Further study for assessing the system

  19. "Deutsche Kultur" und Werbung

    OpenAIRE

    Schug, Alexander

    2010-01-01

    Die Arbeit präsentiert die Geschichte der modernen Wirtschaftswerbung in der ersten Hälfte des 20. Jahrhunderts und zeigt, dass Werbung trotz kultureller Barrieren die Alltagswelten der Deutschen kolonialisierte und Einfluss auf die „deutsche Kultur“ nahm. Die Arbeit zeigt, dass das Konstrukt der „deutschen Kultur“ nicht ausschließlich durch die bürgerliche Hochkultur definiert wurde, sondern zunehmend auch durch Einflüsse der Konsumkultur bestimmt war. Die Bilderwelten der Werbung prägten na...

  20. Work-Life-Balance und Frauenbiographien

    OpenAIRE

    Macha, Hildegard

    2006-01-01

    Work-Life-Balance und Frauenbiographien. - In: Bildungs- und Karrierewege von Frauen / Anne Schlüter (Hrsg.). - Opladen : Budrich, 2006. - S. 17-32. - (Reihe: Frauen- und Geschlechterforschung in der Erziehungswissenschaft ; 2)

  1. Nutzerorientiertes Management von materiellen und immateriellen Informationsobjekten

    OpenAIRE

    Hübsch, Chris

    2001-01-01

    Schaffung einer stabilen, erweiterbaren und skalierbaren Infrastruktur für die Bereitstellung von Diensten im Umfeld von Bibliotheken und ähnlichen wissensanbietenden Einrichtungen unter Verwendung von XML-RPC und Python.

  2. Requirements tests for QC of microSelectron-HDR

    International Nuclear Information System (INIS)

    Gesheva-Atanasova, N.; Gogova, A.; Peycheva, S.; Constantinov, B.; Ganchev, M.

    2000-01-01

    The Quality Control (QC) considers checks and measurements with the purpose of reconstruction, maintaining and increasing the quality of medical procedures and equipment. The QC tests for micro Selectron HDR afterloading machine with 192 Ir which allows more precise calculation and realisation of the tumour's dose have been created and introduced regularly in National Oncological Centre, Sofia. This paper has been cover the machine and software performance, source positioning, application equipment and radiation safety. A list of tests, their frequency, tolerance and action levels, as well as the tests' procedures have been worked out. The used methods are based on establishment of QC protocols. The documents have achieved for a certain period of time and they are available at any time. The experience shows drastically reduction of failures during medical treatment, ensuring the reliability of the used equipment and confidence that all the patients have treated adequate. Where some parameter is above the tolerance is it possible to do proper corrections measures immediately. This QA protocols give assurance that specific objectives being successfully met

  3. Das IHS und die Rolle der Forschungsinstitute

    OpenAIRE

    Keuschnigg, Christian

    2014-01-01

    Das Institut für Höhere Studien und wissenschaftliche Forschung (IHS) ist ein unabhängiges Forschungsinstitut und leistet Forschung und Ausbildung auf Spitzenniveau für Politik, Wirtschaft und Gesellschaft. Im Wettbewerb zwischen Universitäten und angewandten Forschungsinstituten ist das IHS einzigartig, weil es unter einem Dach Grundlagenforschung und forschungsnahe Lehre mit angewandter Forschung für die wissenschaftliche Politikberatung verbindet. Mit den drei Disziplinen Ökonomie, Soziolo...

  4. LDR vs. HDR brachytherapy for localized prostate cancer: the view from radiobiological models.

    Science.gov (United States)

    King, Christopher R

    2002-01-01

    Permanent LDR brachytherapy and temporary HDR brachytherapy are competitive techniques for clinically localized prostate radiotherapy. Although a randomized trial will likely never be conducted comparing these two forms of brachytherapy, a comparative radiobiological modeling analysis proves useful in understanding some of their intrinsic differences, several of which could be exploited to improve outcomes. Radiobiological models based upon the linear quadratic equations are presented for fractionated external beam, fractionated (192)Ir HDR brachytherapy, and (125)I and (103)Pd LDR brachytherapy. These models incorporate the dose heterogeneities present in brachytherapy based upon patient-derived dose volume histograms (DVH) as well as tumor doubling times and repair kinetics. Radiobiological parameters are normalized to correspond to three accepted clinical risk factors based upon T-stage, PSA, and Gleason score to compare models with clinical series. Tumor control probabilities (TCP) for LDR and HDR brachytherapy (as monotherapy or combined with external beam) are compared with clinical bNED survival rates. Predictions are made for dose escalation with HDR brachytherapy regimens. Model predictions for dose escalation with external beam agree with clinical data and validate the models and their underlying assumptions. Both LDR and HDR brachytherapy achieve superior tumor control when compared with external beam at conventional doses (LDR brachytherapy as boost achieves superior tumor control than when used as monotherapy. Stage for stage, both LDR and current HDR regimens achieve similar tumor control rates, in agreement with current clinical data. HDR monotherapy with large-dose fraction sizes might achieve superior tumor control compared with LDR, especially if prostate cancer possesses a high sensitivity to dose fractionation (i.e., if the alpha/beta ratio is low). Radiobiological models support the current clinical evidence for equivalent outcomes in localized

  5. Dose rate considerations in brachytherapy: biological equivalence of LDR and HDR

    International Nuclear Information System (INIS)

    Orton, C.G.

    1994-01-01

    The linear-quadratic model for cell survival and bioeffect doses is discussed and equations for low dose rate (LDR), high dose rate (HDR) and intermediate situations are presented. The model, when used to define LDR and single fractions of HDR, shows, that these correspond to irradiations lasting longer than about 14 hours or shorter than about 0.7 hours, respectively. It is shown that, for HDR to be as safe and effective as LDR, the dose-rate effect of LDR has to be replaced by the fractionation-effect of HDR. This is necessary in order to take advantage of the differential repair characteristics between late-reacting normal tissue and tumor cells at low doses and low dose rates. Using the linear-quadratic model to simulate repair mathematically, it is shown that the number of fractions required is highly dependent upon what parameters are assumed for normal tissues and tumor, as well as whether or not there is any physical advantage gained by conversion from LDR to HDR. (author). 20 refs., 7 figs

  6. Evaluation of a HDR image sensor with logarithmic response for mobile video-based applications

    Science.gov (United States)

    Tektonidis, Marco; Pietrzak, Mateusz; Monnin, David

    2017-10-01

    The performance of mobile video-based applications using conventional LDR (Low Dynamic Range) image sensors highly depends on the illumination conditions. As an alternative, HDR (High Dynamic Range) image sensors with logarithmic response are capable to acquire illumination-invariant HDR images in a single shot. We have implemented a complete image processing framework for a HDR sensor, including preprocessing methods (nonuniformity correction (NUC), cross-talk correction (CTC), and demosaicing) as well as tone mapping (TM). We have evaluated the HDR sensor for video-based applications w.r.t. the display of images and w.r.t. image analysis techniques. Regarding the display we have investigated the image intensity statistics over time, and regarding image analysis we assessed the number of feature correspondences between consecutive frames of temporal image sequences. For the evaluation we used HDR image data recorded from a vehicle on outdoor or combined outdoor/indoor itineraries, and we performed a comparison with corresponding conventional LDR image data.

  7. Highly efficient CRISPR/HDR-mediated knock-in for mouse embryonic stem cells and zygotes.

    Science.gov (United States)

    Wang, Bangmei; Li, Kunyu; Wang, Amy; Reiser, Michelle; Saunders, Thom; Lockey, Richard F; Wang, Jia-Wang

    2015-10-01

    The clustered regularly interspaced short palindromic repeat (CRISPR) gene editing technique, based on the non-homologous end-joining (NHEJ) repair pathway, has been used to generate gene knock-outs with variable sizes of small insertion/deletions with high efficiency. More precise genome editing, either the insertion or deletion of a desired fragment, can be done by combining the homology-directed-repair (HDR) pathway with CRISPR cleavage. However, HDR-mediated gene knock-in experiments are typically inefficient, and there have been no reports of successful gene knock-in with DNA fragments larger than 4 kb. Here, we describe the targeted insertion of large DNA fragments (7.4 and 5.8 kb) into the genomes of mouse embryonic stem (ES) cells and zygotes, respectively, using the CRISPR/HDR technique without NHEJ inhibitors. Our data show that CRISPR/HDR without NHEJ inhibitors can result in highly efficient gene knock-in, equivalent to CRISPR/HDR with NHEJ inhibitors. Although NHEJ is the dominant repair pathway associated with CRISPR-mediated double-strand breaks (DSBs), and biallelic gene knock-ins are common, NHEJ and biallelic gene knock-ins were not detected. Our results demonstrate that efficient targeted insertion of large DNA fragments without NHEJ inhibitors is possible, a result that should stimulate interest in understanding the mechanisms of high efficiency CRISPR targeting in general.

  8. A Survey on the Acceptance and the Use of HDR Photography Among Croatian Photographers

    Directory of Open Access Journals (Sweden)

    Maja Strgar Kurecic

    2013-04-01

    Full Text Available The emerging field of high dynamic range (HDR imaging is directly linked to diverse existing disciplines such as radiometry, photometry, colorimetry and colour appearance - each dealing with specific aspects of light and its perception by humans. Although the idea is not new, it has not been widely used until just a few years ago when digital cameras gained popularity and the computers processing power increased significantly. Now this photographic technique is widely spread and used, but even more often – misused. A research was conducted by means of a questionnaire in order to get some actual information about how Croatian photographers see the HDR photography and how they employ it. The results of the survey proved that indeed a great interest exists in the technique, but that many photographers are scared away from the HDR photography because of the misconception that the artificial look is an unavoidable side effect of the HDR processing. The fact is, however, that the final HDR image is a result of the tone mapping process and post-corrections and adjustments, entirely dependent on the photographer’s intent and vision, as well as his understanding of various adjustments available. The results of the questionnaire have also pointed out to other widely spread misconceptions which are discussed in this paper.

  9. Diagrammatik und Wissensorganisation

    Directory of Open Access Journals (Sweden)

    Sascha Freyberg

    2012-11-01

    Full Text Available EinleitungDie Formen des „Sichtbarmachens“ in der Wissenschaft reichen von „Abbildungen“ über „Modelle“ bis hin zu „Simulationen“. Sie können u.a. gezeichnet, fotografiert, geometrisch konstruiert oder durch Sensorik vermittelt, digital prozessiert werden. Ihre Funktionen erstrecken sich von der Orientierung bis hin zur (hypothetischen Voraussage und somit auch vom Überblick bis zur Evidenzsuggestion. Generell handelt es sich um vereinfachte (und vereinfachende Darstellungen von (teilweise sehr komplexen Sachverhalten, zu deren Verständnis sie beitragen sollen; daher können sie bei Lernprozessen, d.h. in der Vermittlung und auch bei der Organisation von Wissen eine wichtige Rolle spielen. Diese kommt ihnen nun nicht nur zu, weil sie – wie in den mittelalterlichen Mnemotechniken – als Gedächtnisstützen für bekannte Sachverhalte dienen. Sondern resultiert auch aus ihrem Potenzial für die Entdeckung von neuen Zusammenhängen. Der folgende Artikel diskutiert die Darstellungsform des Diagramms. Es wird hier mit dem Gedanken gespielt, dass die in der universalen Zeichentheorie von C.S. Peirce entwickelte Diagrammatik wichtige Impulse für eine Untersuchung des Zusammenhangs von Wissen und Bildlichkeit geben kann.

  10. Arbeitsgestaltung und Mitarbeiterqualifizierung

    Science.gov (United States)

    Weiss-Oberdorfer, Werner; Hörner, Barbara; Holm, Ruth; Pirner, Evelin

    Die Wertkette gliedert ein Unternehmen in strategisch relevante Tätigkeiten, um dadurch Kostenverhalten sowie vorhandene und potenzielle Differenzierungsquellen zu verstehen. Wenn ein Unternehmen diese strategisch wichtigen Aktivitäten billiger oder besser als seine Konkurrenten erledigt, verschafft es sich einen Wettbewerbsvorteil." Michael Porter, 1985

  11. Substanzbegriff und systematik

    NARCIS (Netherlands)

    Lütjeharms, W.J.

    1934-01-01

    Bei der Einteilung der Organismen, welche in dieser Arbeit mir von botanischem Gesichtspunkt betrachtet wird, ist die Frage nach „wesentlichen” Merkmalen oder Einteilungsgründen von grosser Wichtigkeit. Es ist die Frage nach der Substanz (Essenz) und den akzidentellen Merkmalen. Der Substanzbegriff

  12. Stenting und technische Stentumgebung

    Science.gov (United States)

    Hoffstetter, Marc; Pfeifer, Stefan; Schratzenstaller, Thomas; Wintermantel, Erich

    In hoch entwickelten Industrieländern stehen laut Weltgesundheitsorganisation (WHO) Herz-Kreislauf-Erkrankungen und speziell die Koronare Herzkrankheit (KHK) an erster Stelle der Todesursachen. In Deutschland betrug die Zahl der erfassten, an KHK erkrankten Personen ohne Berücksichtigung der Dunkelziffer allein im Jahre 2001 über 473.000. Die KHK war im Jahre 2003 mit 92.673 erfassten Todesfällen immer noch die häufigste Todesursache, obgleich in Deutschland die Häufigkeit der Koronarinterventionen zur Behandlung der KHK zwischen 1984 und 2003 um fast das 80fache von 2.809 auf 221.867 Eingriffe pro Jahr gestiegen ist [1]. Neben der hohen Zahl an Todesfällen haben die betroffenen Personen durch chronische Schmerzen und eingeschränkte körperliche Leistungsfähigkeit zusätzlich eine starke Beeinträchtigung der Lebensqualität [2].In Folge dessen wird die erkrankte Person häufig zum Pflegefall was neben den gesundheitlichen Aspekten auch eine sozioökonomische Komponente in Form der fehlenden Arbeitskraft und den auftretenden Pflegekosten nach sich zieht. Die Kosten für die Behandlung der KHK in Deutschland beliefen sich im Jahre 2002 laut Statistischem Bundesamt auf rund 6,9 Mrd. €. Verglichen mit ähnlichen Zahlen der USA dürfte sich der entstandene Schaden für die deutsche Volkswirtschaft im zwei- bis dreistelligen Milliardenbereich bewegen [3].

  13. Towards real-time 3D ultrasound planning and personalized 3D printing for breast HDR brachytherapy treatment

    International Nuclear Information System (INIS)

    Poulin, Eric; Gardi, Lori; Fenster, Aaron; Pouliot, Jean; Beaulieu, Luc

    2015-01-01

    Two different end-to-end procedures were tested for real-time planning in breast HDR brachytherapy treatment. Both methods are using a 3D ultrasound (3DUS) system and a freehand catheter optimization algorithm. They were found fast and efficient. We demonstrated a proof-of-concept approach for personalized real-time guidance and planning to breast HDR brachytherapy treatments

  14. HDR imaging and color constancy: two sides of the same coin?

    Science.gov (United States)

    McCann, John J.

    2011-01-01

    At first, we think that High Dynamic Range (HDR) imaging is a technique for improved recordings of scene radiances. Many of us think that human color constancy is a variation of a camera's automatic white balance algorithm. However, on closer inspection, glare limits the range of light we can detect in cameras and on retinas. All scene regions below middle gray are influenced, more or less, by the glare from the bright scene segments. Instead of accurate radiance reproduction, HDR imaging works well because it preserves the details in the scene's spatial contrast. Similarly, on closer inspection, human color constancy depends on spatial comparisons that synthesize appearances from all the scene segments. Can spatial image processing play similar principle roles in both HDR imaging and color constancy?

  15. WE-G-BRC-02: Risk Assessment for HDR Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Mayadev, J. [UC Davis Comprehensive Cancer Center (United States)

    2016-06-15

    Failure Mode and Effects Analysis (FMEA) originated as an industrial engineering technique used for risk management and safety improvement of complex processes. In the context of radiotherapy, the AAPM Task Group 100 advocates FMEA as the framework of choice for establishing clinical quality management protocols. However, there is concern that widespread adoption of FMEA in radiation oncology will be hampered by the perception that implementation of the tool will have a steep learning curve, be extremely time consuming and labor intensive, and require additional resources. To overcome these preconceptions and facilitate the introduction of the tool into clinical practice, the medical physics community must be educated in the use of this tool and the ease in which it can be implemented. Organizations with experience in FMEA should share their knowledge with others in order to increase the implementation, effectiveness and productivity of the tool. This session will include a brief, general introduction to FMEA followed by a focus on practical aspects of implementing FMEA for specific clinical procedures including HDR brachytherapy, physics plan review and radiosurgery. A description of common equipment and devices used in these procedures and how to characterize new devices for safe use in patient treatments will be presented. This will be followed by a discussion of how to customize FMEA techniques and templates to one’s own clinic. Finally, cases of common failure modes for specific procedures (described previously) will be shown and recommended intervention methodologies and outcomes reviewed. Learning Objectives: Understand the general concept of failure mode and effect analysis Learn how to characterize new equipment for safety Be able to identify potential failure modes for specific procedures and learn mitigation techniques Be able to customize FMEA examples and templates for use in any clinic.

  16. Transillumination and HDR Imaging for Proximal Caries Detection.

    Science.gov (United States)

    Lederer, A; Kunzelmann, K H; Hickel, R; Litzenburger, F

    2018-02-01

    The purpose was to develop an in vitro model for the validation of near-infrared transillumination (NIRT) for proximal caries detection, to enhance NIRT with high-dynamic-range imaging (HDRI), and to compare both methods, using micro-computed tomography (µCT) as a reference standard. Both proximal surfaces of 53 healthy or decayed permanent human teeth were examined using the Diagnocam (DC) (KaVo) and NIRT with HDRI (NIRT-HDRI). NIRT was combined with HDRI to improve the diagnostic performance by reducing under- and overexposed image areas. For NIRT-HDRI, an exposure series was captured and merged into a single HDR image. A classification was applied according to lesion depth. All surfaces were assessed twice by 2 trained examiners, and additionally with µCT for validation. The Kappa statistic was used to calculate inter-rater reliability and agreement between DC and NIRT-HDRI. Inter-rater reliability (weighted Kappa, wκ) showed very good agreement for the DC (0.90) and NIRT-HDRI (0.96). The overall agreement (wκ) was almost perfect (0.85). In the individual categories (0 to 4), the agreement (simple Kappa) ranged from almost perfect (category 4) to moderate (1 and 2) to substantial (categories 0 and 3). Sensitivity and specificity of sound surfaces, enamel, and dentin caries ranged from 0.57 to 0.99 and were similar for both methods in the different categories. NIRT-HDRI had a higher sensitivity for sound surfaces and enamel caries, as well as a higher specificity for dentin caries. Regarding the obtained images, HDRI allowed for the detection of caries within a greater range of luminance levels, resulting in a more detailed visualization of structures without under- or overexposure. However, HDRI this did not improve the diagnostics significantly. Distinguishing between a processed demineralized enamel and dentin lesions appears to be a problem specific to NIRT and cannot be balanced using HDRI.

  17. Acceptance testing and commissioning of a new model HDR afterloader

    International Nuclear Information System (INIS)

    McDermott, Patrick N.; Somnay, Archana R.; Alecu, Rodica

    1996-01-01

    We have recently performed acceptance testing procedures and have commissioned a new model HDR afterloader, the Varian VariSource with ''Intelligent Drive.'' Our site was one of the first installations worldwide. It is our intent to describe our tests and the results of the tests particularly as they may differ from other afterloaders. The Ir-192 source is unique among afterloaders marketed in the US in that it is very slender (OD of source wire is 0.59 mm) and relatively long (two 0.5 cm sources for a total active length of 1.0 cm). A check of source homogeneity by autoradiograph as urged by the US Nuclear Regulatory Commission demonstrates no detectable source inhomogeneity. Reentrant well ionization chambers are calibrated in the US with a 3.5 mm long source at Accredited Dosimetry Calibration Laboratories. Therefore calibration needs to be considered with some care. Calibration of the first delivered source with a well ionization chamber indicated agreement with the manufacturer's stated activity to within 0.5%. Source positioning is checked with a device called a 'cam scale'. Tests have been carried out on this system and it has been found to accurately indicate source position to within ±0.5 mm. Timer accuracy has been found to be better than 0.1% for dwell times of several hundred seconds. The intelligent drive system and the small source diameter allow the source wire to negotiate paths with small radius of curvature. A series of tests have been made in which the source is forced to negotiate 'U' turns of decreasing radius of curvature. A 4.7 F, 100 cm long catheter was used for these tests and the 'U' turn was positioned at approximately 90 cm. Under these conditions, the VariSource was consistently able to traverse a 1.25 cm radius of curvature, which is better than the manufacturer's stated limit of 1.5 cm

  18. WE-G-BRC-02: Risk Assessment for HDR Brachytherapy

    International Nuclear Information System (INIS)

    Mayadev, J.

    2016-01-01

    Failure Mode and Effects Analysis (FMEA) originated as an industrial engineering technique used for risk management and safety improvement of complex processes. In the context of radiotherapy, the AAPM Task Group 100 advocates FMEA as the framework of choice for establishing clinical quality management protocols. However, there is concern that widespread adoption of FMEA in radiation oncology will be hampered by the perception that implementation of the tool will have a steep learning curve, be extremely time consuming and labor intensive, and require additional resources. To overcome these preconceptions and facilitate the introduction of the tool into clinical practice, the medical physics community must be educated in the use of this tool and the ease in which it can be implemented. Organizations with experience in FMEA should share their knowledge with others in order to increase the implementation, effectiveness and productivity of the tool. This session will include a brief, general introduction to FMEA followed by a focus on practical aspects of implementing FMEA for specific clinical procedures including HDR brachytherapy, physics plan review and radiosurgery. A description of common equipment and devices used in these procedures and how to characterize new devices for safe use in patient treatments will be presented. This will be followed by a discussion of how to customize FMEA techniques and templates to one’s own clinic. Finally, cases of common failure modes for specific procedures (described previously) will be shown and recommended intervention methodologies and outcomes reviewed. Learning Objectives: Understand the general concept of failure mode and effect analysis Learn how to characterize new equipment for safety Be able to identify potential failure modes for specific procedures and learn mitigation techniques Be able to customize FMEA examples and templates for use in any clinic

  19. Quality assurance of HDR prostate plans: program implementation at a community hospital.

    Science.gov (United States)

    Rush, Jennifer B; Thomas, Michael D

    2005-01-01

    Adenocarcinoma of the prostate is currently the most commonly diagnosed cancer in men in the United States, and the second leading cause of cancer mortality. The utilization of radiation therapy is regarded as the definitive local therapy of choice for intermediate- and high-risk disease, in which there is increased risk for extracapsular extension, seminal vesicle invasion, or regional node involvement. High-dose-rate (HDR) brachytherapy is a logical treatment modality to deliver the boost dose to an external beam radiation therapy (EBRT) treatment to increase local control rates. From a treatment perspective, the utilization of a complicated treatment delivery system, the compressed time frame in which the procedure is performed, and the small number of large dose fractions make the implementation of a comprehensive quality assurance (QA) program imperative. One aspect of this program is the QA of the HDR treatment plan. Review of regulatory and medical physics professional publications shows that substantial general guidance is available. We provide some insight to the implementation of an HDR prostate plan program at a community hospital. One aspect addressed is the utilization of the low-dose-rate (LDR) planning system and the use of existing ultrasound image sets to familiarize the radiation therapy team with respect to acceptable HDR implant geometries. Additionally, the use of the LDR treatment planning system provided a means to prospectively determine the relationship between the treated isodose volume and the product of activity and time for the department's planning protocol prior to the first HDR implant. For the first 12 HDR prostate implants, the root-mean-square (RMS) deviation was 3.05% between the predicted product of activity and time vs. the actual plan values. Retrospective re-evaluation of the actual implant data reduced the RMS deviation to 2.36%.

  20. Quality assurance of HDR prostate plans: Program implementation at a community hospital

    International Nuclear Information System (INIS)

    Rush, Jennifer B.; Thomas, Michael D.

    2005-01-01

    Adenocarcinoma of the prostate is currently the most commonly diagnosed cancer in men in the United States, and the second leading cause of cancer mortality. The utilization of radiation therapy is regarded as the definitive local therapy of choice for intermediate- and high-risk disease, in which there is increased risk for extracapsular extension, seminal vesicle invasion, or regional node involvement. High-dose-rate (HDR) brachytherapy is a logical treatment modality to deliver the boost dose to an external beam radiation therapy (EBRT) treatment to increase local control rates. From a treatment perspective, the utilization of a complicated treatment delivery system, the compressed time frame in which the procedure is performed, and the small number of large dose fractions make the implementation of a comprehensive quality assurance (QA) program imperative. One aspect of this program is the QA of the HDR treatment plan. Review of regulatory and medical physics professional publications shows that substantial general guidance is available. We provide some insight to the implementation of an HDR prostate plan program at a community hospital. One aspect addressed is the utilization of the low-dose-rate (LDR) planning system and the use of existing ultrasound image sets to familiarize the radiation therapy team with respect to acceptable HDR implant geometries. Additionally, the use of the LDR treatment planning system provided a means to prospectively determine the relationship between the treated isodose volume and the product of activity and time for the department's planning protocol prior to the first HDR implant. For the first 12 HDR prostate implants, the root-mean-square (RMS) deviation was 3.05% between the predicted product of activity and time vs. the actual plan values. Retrospective re-evaluation of the actual implant data reduced the RMS deviation to 2.36%

  1. Sorption und Verbreitung per- und polyfluorierter Chemikalien (PFAS) in Wasser und Boden

    OpenAIRE

    Gellrich, Vanessa

    2014-01-01

    PFAS (= Perfluoroalkyl and Polyfluoroalkyl Substances) sind persistente organische Spurenstoffe, die weltweit in verschiedenen Umweltkompartimenten nachgewiesen werden konnten. Im Rahmen dieser Dissertation sollte die Frage geklärt werden, wie die physikalisch-chemischen Eigenschaften der PFAS - besonders ihre Sorption am Boden - ihr Verhalten und ihre Verbreitung in der Umwelt beeinflussen. Dazu wurde zunächst eine Messmethode entwickelt, optimiert und validiert, mit der 17 per- und polyf...

  2. SU-D-19A-07: Dosimetric Comparison of HDR Plesiotherapy and Electron Beam Therapy for Superficial Lesions

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, A; Jacob, D; Andreou, K; Raben, A; Chen, H; Koprowski, C; Mourtada, F [Christiana Care Hospital, Newark, DE (United States)

    2014-06-01

    Purpose: Large superficial (skin, soft tissue sarcoma) lesions located on curved areas are hard to treat with electrons. The Freiburg Flap (Nucletron, Netherlands) is a flexible mesh style surface which can be easily shaped to fit curved surfaces for reproducible HDR fraction delivery. To understand the fundamental dosimetric differences, a dosimetric comparison was made between HDR plesiotherapy (Freiburg applicator for lesions over 4cm) and external electron beam radiotherapy over cases with varying target curvature (both stylized and clinical cases). Methods: Four stylized cases with variable complexity were created using artificial DICOM axial CT slices and RT structures (a square and three curved structures on a 4.5cm radius cylinder). They were planned using Oncentra v4.3 and exported to Pinnacle v9.6 for electrons planning. The HDR source dwell positions were optimized for the best coverage of the targets using graphical optimization. Electron treatment plans were created in Pinnacle using the same CT and RT structures of three HDR cases with surface lesions previously treated with the Freiburg flap. The En face electron plans used 6-12 MeV electrons and 0.5–1 cm bolus was added to increase surface dose. The electron plans were prescribed to an isodose line to conform to the target. Results: For all lesions, the average target dose coverage was similar (D90ave of 100% for HDR vs 101% for electrons). For lesions with high curvature, the HDR coverage was better (D90 102% vs D90 97% for electron). For all cases, adjacent structures high dose region was lower for HDR than electrons (D1cc 100% for HDR vs D1cc 111% for electrons). Conclusion: HDR plesiotherapy offers excellent target conformity for superficial targets similar to electrons. However, for lesions with complex curved surfaces, HDR has the advantage to achieve better dose distributions using graphical optimization to spare adjacent normal tissue while maximizing target coverage.

  3. Time to PSA rise differentiates the PSA bounce after HDR and LDR brachytherapy of prostate cancer.

    Science.gov (United States)

    Burchardt, Wojciech; Skowronek, Janusz

    2018-02-01

    To investigate the differences in prostate-specific antigen (PSA) bounce (PB) after high-dose-rate (HDR-BT) or low-dose-rate (LDR-BT) brachytherapy alone in prostate cancer patients. Ninety-four patients with localized prostate cancer (T1-T2cN0), age ranged 50-81 years, were treated with brachytherapy alone between 2008 and 2010. Patients were diagnosed with adenocarcinoma, Gleason score ≤ 7. The LDR-BT total dose was 144-145 Gy, in HDR-BT - 3 fractions of 10.5 or 15 Gy. The initial PSA level (iPSA) was assessed before treatment, then PSA was rated every 3 months over the first 2 years, and every 6 months during the next 3 years. Median follow-up was 3.0 years. Mean iPSA was 7.8 ng/ml. In 58 cases, PSA decreased gradually without PB or biochemical failure (BF). In 24% of patients, PB was observed. In 23 cases (24%), PB was observed using 0.2 ng/ml definition; in 10 cases (11%), BF was diagnosed using nadir + 2 ng/ml definition. The HDR-BT and LDR-BT techniques were not associated with higher level of PB (26 vs. 22%, p = 0.497). Time to the first PSA rise finished with PB was significantly shorter after HDR-BT then after LDR-BT (median, 10.5 vs. 18.0 months) during follow-up. Predictors for PB were observed only after HDR-BT. Androgen deprivation therapy (ADT) and higher Gleason score decreased the risk of PB (HR = 0.11, p = 0.03; HR = 0.51, p = 0.01). The higher PSA nadir and longer time to PSA nadir increased the risk of PB (HR 3.46, p = 0.02; HR 1.04, p = 0.04). There was no predictors for PB after LDR-BT. HDR-BT and LDR-BT for low and intermediate risk prostate cancer had similar PB rate. The PB occurred earlier after HDR-BT than after LDR-BT. ADT and higher Gleason score decreased, and higher PSA nadir and longer time to PSA nadir increased the risk of PB after HDR-BT.

  4. A rectum shield for the circular applicator system of a selectron unit (HDR and LDR afterloading)

    International Nuclear Information System (INIS)

    Hetzel, H.; McCoy, M.; Kamleitner, H.; Frommhold, H.

    1987-01-01

    In order to decrease the morbidity rate after combined radiotherapy of the cervix carcinoma, a tungsten shield 3 and 5 mm thick for the rectum has been developed by the authors which is applied with the ring and pin applicator of the selectron unit (LDR and HDR afterloading). The isodose curves were measured in a plexiglas phantom, and the radiation dose at the reference points was determined by means of a ionization dosemeter. The phantom measurements were performed with the same arrangement of sources as applied in radiotherapy. The measurements showed a dose reduction at point Rmax of 33% (HDR) and 44% (LDR) with the tungsten shield 5 mm thick. (orig.) [de

  5. Plazentaanatomie und -physiologie mit uteroplazentarem Kreislauf

    NARCIS (Netherlands)

    Engel, N.; Schreiber, J. U.; Kranke, Peter

    2017-01-01

    Die Plazenta besteht neben der Nabelschnur aus parenchymatösem Gewebe, der sog. Eihaut (Amnion) und der Zottenhaut (Chorion). Sie fungiert als Schnittstelle zwischen Mutter und Fetus und ermöglicht den physiologischen Transfer von Gasen, Nährstoffen und Metaboliten. Die Funktion der Plazenta ist als

  6. Management of a HDR brachytherapy system in the Hospital Juarez of Mexico; Gestion de un sistema de braquiterapia HDR een el Hospital Juarez de Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Serrano F, A.G.; Ramirez R, G.; Gil G, R. [Hospital Juarez de Mexico, Av. l.P.N. 5160, Col. Magdalena de las Salinas, 07760 Mexico D.F. (Mexico); Azorin N, J. [UAM-I, 09340 Mexico D.F. (Mexico); Rivera M, T. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Unidad Legaria del IPN, Av. Legaria 694, Col. Irrigacion, 11500 Mexico D.F. (Mexico)

    2007-07-01

    Full text: In the Hospital Juarez of Mexico, it is carried out a project to implement a Brachytherapy system with high dose rate (HDR) through a Management quality program. In our work center this treatment modality in patients with cervicouterine cancer is used (CaCu), and constantly it is necessary to carry out improvements in the procedures, with the purpose of optimizing them and in consequence to complete the principles of the Radiological Protection, guaranteeing this way, an attention with the quality and safety, such that allow to diminish the risks to the patients and to assure that the received dose in critical organs it finds inside the permitted therapeutic limits, without commit the radiosensitive response of healthy organs. In this work an analysis of the implementation of this system is presented, detailing the procedures so much in the technological infrastructure like human and indicating the necessary technical and operative requirements to reach an adequate practice in HDR brachytherapy. (Author)

  7. Hegel und Gorgias

    DEFF Research Database (Denmark)

    Huggler, Jørgen

    Hegel und Gorgias /Jørgen Huggler (University of Aarhus, Denmark) (huggler(at)dpu.dk) Hegels Verständnis des Sophist Gorgias von Leontinoi in den Vorlesungen über die Geschichte der Philosophie gründet auf seine eigene Interpretation der Eleaten, insbesondere Zenon. Aufgrund eigener philosophischer...... „Gründen“, einen echten Beitrag zu dieser Entwicklung des griechischen Denkens geliefert. Vor allen scheint Gorgias die dialektischen Bemühungen der Eleaten fortgesetzt zu haben. Hegels Auslegung des Gorgias kann den lauwarmen Empfang der Sophisten in den deutschen Beiträgen zur Geschichte der Philosophie...... des späten 18. Jahrhunderts (Meiners, Tiedemann, Stäudlin, Buhle und Tennemann) gegenübergestellt werden. In der Tat ist Hegels philosophisches Verständnis ausreichend, um positive Kommentare zu allen Teilen der Diskussion in Gorgias Argument „Über das Nicht-Seiende, oder Über der Natur“ zu geben...

  8. Rudolf Streinz. Meinungs- und Informationsfreiheit zwischen Ost und West / Henn-Jüri Uibopuu

    Index Scriptorium Estoniae

    Uibopuu, Henn-Jüri, 1929-2012

    1983-01-01

    Tutvustus: Streinz, Rudolf. Meinungs- und Informationsfreiheit zwischen Ost und West : Möglichkeiten und Grenzen intersystemarer völkerrechtlicher Garantien in einem systemkonstituierenden Bereich. Ebelsbach : Rolf Gremer, 1981

  9. Zur historischen Aufarbeitung und medialen Vermittlung der Shoah in Italien und Deutschland

    Directory of Open Access Journals (Sweden)

    Peter Kuon

    2016-03-01

    Full Text Available Claudia Müller, Patrick Ostermann und Karl-Siegbert Rehberg, Hrsg., Die Shoah in Geschichte und Erinnerung: Perspektiven medialer Vermittlung in Italien und Deutschland (Bielefeld: transcript, 2015.

  10. Ethik und Sicherheitstechnik. Eine Handreichung

    NARCIS (Netherlands)

    Ammicht-Quinn, Regina; Nagenborg, Michael Herbert; Rampp, Benjamin; Wolkenstein, Andreas F.X.; Ammicht-Quinn, Regina

    2013-01-01

    Mit dem Programm „Forschung für die zivile Sicherheit“ fördert die Bundesregierung im Rahmen der „Hightech-Strategie für Deutschland“ erstmals unmittelbar die Entwicklung von Techniken, die der Schaffung und Bewahrung von ziviler Sicherheit dienen. Bei der Erforschung und Entwicklung von

  11. Emergency rescue in accidents with HDR afterloading units

    International Nuclear Information System (INIS)

    Kaulich, T.W.; Nuesslin, F.; Becker, G.; Lamprecht, U.; Bamberg, M.

    1999-01-01

    Problem: HDR brachyradiotherapy has minimized the exposure to radiation of the personnel working in this field. Nonetheless there are periodically reported troubles with afterloading units concerning the retraction of sources that require immediate action for the limitation of possible damage. Legal Principles according to the German Regulation Concerning Protection against Radiation (Strahlenschutzverordnung=StrlSchV): If in afterloading brachyradiotherapy the radiation source remains extended through malfunction we deal with an emergency according to the StrlSchV. The rescue personnel should be chosen in accordance with Paragraph 50 StrlSchV. Organization of the Rescue of the Patient: The quickest possible rescue of a patient in an emergency demands an unequivocal definition of responsibilities. Our recommendations in this instance: The physicist is responsible for the organization of the emergency rescue. The radiation oncologist in charge informs himself about the necessary emergency measures before starting the treatment and carries out the emergency rescue. If the physicist diagnoses a failure in the retraction of the source he tries to remove the failure. If he doesn't succeed in retracting the source the radiation oncologist carries out the rescue of the patient. The organizational structure of the clinic allowing, the emergency physician should invariably be the physician who placed the applicator. In the emergency rescue the radiation oncologist should be protected by a lead barrier and use manipulators. Dose Assessment in Personnel and Patient: The radiation exposure of the rescue personnel is calculated from the photon-equivalence dose H x with the help of the dose-rate constant of 192 Ir. According to the same procedure there can be evaluated the local radiation exposure of the patient concerned. Conclusions: Generally speaking, all considerations regarding the topic of emergency rescue should always start out from a worst-case scenario. Of all the

  12. Bildanalyse in Medizin und Biologie

    Science.gov (United States)

    Athelogou, Maria; Schönmeyer, Ralf; Schmidt, Günther; Schäpe, Arno; Baatz, Martin; Binnig, Gerd

    Heutzutage sind bildgebende Verfahren aus medizinischen Untersuchungen nicht mehr wegzudenken. Diverse Methoden - basierend auf dem Einsatz von Ultraschallwellen, Röntgenstrahlung, Magnetfeldern oder Lichtstrahlen - werden dabei spezifisch eingesetzt und liefern umfangreiches Datenmaterial über den Körper und sein Inneres. Anhand von Mikroskopieaufnahmen aus Biopsien können darüber hinaus Daten über die morphologische Eigenschaften von Körpergeweben gewonnen werden. Aus der Analyse all dieser unterschiedlichen Arten von Informationen und unter Konsultation weiterer klinischer Untersuchungen aus diversen medizinischen Disziplinen kann unter Berücksichtigung von Anamnesedaten ein "Gesamtbild“ des Gesundheitszustands eines Patienten erstellt werden. Durch die Flut der erzeugten Bilddaten kommt der Bildverarbeitung im Allgemeinen und der Bildanalyse im Besonderen eine immer wichtigere Rolle zu. Gerade im Bereich der Diagnoseunterstützung, der Therapieplanung und der bildgeführten Chirurgie bilden sie Schlüsseltechnologien, die den Forschritt nicht nur auf diesen Gebieten maßgeblich vorantreiben.

  13. [Die baltischen Lande im Zeitalter der Reformation und Konfessionalisierung. Livland, Estland, Ösel, Ingermanland, Kurland und Letgallen. Stadt, Land und Konfession 1500-1721. 2. und 3. Teil] / Anti Selart

    Index Scriptorium Estoniae

    Selart, Anti, 1973-

    2012-01-01

    Arvustus: Die baltischen Lande im Zeitalter der Reformation und Konfessionalisierung. Livland, Estland, Ösel, Ingermanland, Kurland und Letgallen. Stadt, Land und Konfession 1500-1721. Hrsg. von Matthias Asche, Werner Buchholz, Anton Schindling. 2. und 3. Teil.

  14. Determinación de la distribución de dosis en tratamientos de cáncer de mama con fuentes de 192 Ir HDR / Determination of doses distributions on breast cancer treatments with 192 Ir HDR sources

    OpenAIRE

    Beltrán Gómez, Cristian Camilo

    2010-01-01

    La Braquiterapia de alta tasa de dosis HDR es una moderna técnica de tratamiento que ha venido teniendo un rápido crecimiento en su uso clínico, reemplazando a la braquiterapia de baja tasa de dosis LDR. La braquiterapia HDR se caracteriza por utilizar fuentes radiactivas con tasas de dosis mayores a 12 Gy/h, por tanto con propósitos de protección radiológica debe ser realizada con equipos de carga remota, es común en los tratamientos de braquiterapia HDR depositar altas dosis por fracción, c...

  15. Presumed atypical HDR syndrome associated with Band Keratopathy and pigmentary retinopathy.

    Science.gov (United States)

    Kim, Cinoo; Cheong, Hae Il; Kim, Jeong Hun; Yu, Young Suk; Kwon, Ji Won

    2011-01-01

    This report describes presumed atypical hypoparathyroidism, deafness, and renal dysplasia (HDR) syndrome associated with unexpected ocular findings. The patient had exotropia, bilateral band keratopathy, and pigmentary retinopathy, including attenuated retinal vessels and atrophy of the retinal pigment epithelium. Even though the calcific plaques were successfully removed, visual acuity in both eyes gradually decreased and electroretinography was extinguished. Copyright 2009, SLACK Incorporated.

  16. A gEUD-based inverse planning technique for HDR prostate brachytherapy: Feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Giantsoudi, D. [Department of Radiological Sciences, University of Texas Health Sciences Center, San Antonio, Texas 78229 (United States); Department of Radiation Oncology, Francis H. Burr Proton Therapy Center, Boston, Massachusetts 02114 (United States); Baltas, D. [Department of Medical Physics and Engineering, Strahlenklinik, Klinikum Offenbach GmbH, 63069 Offenbach (Germany); Nuclear and Particle Physics Section, Physics Department, University of Athens, 15701 Athens (Greece); Karabis, A. [Pi-Medical Ltd., Athens 10676 (Greece); Mavroidis, P. [Department of Radiological Sciences, University of Texas Health Sciences Center, San Antonio, Texas 78299 and Department of Medical Radiation Physics, Karolinska Institutet and Stockholm University, 17176 (Sweden); Zamboglou, N.; Tselis, N. [Strahlenklinik, Klinikum Offenbach GmbH, 63069 Offenbach (Germany); Shi, C. [St. Vincent' s Medical Center, 2800 Main Street, Bridgeport, Connecticut 06606 (United States); Papanikolaou, N. [Department of Radiological Sciences, University of Texas Health Sciences Center, San Antonio, Texas 78299 (United States)

    2013-04-15

    Purpose: The purpose of this work was to study the feasibility of a new inverse planning technique based on the generalized equivalent uniform dose for image-guided high dose rate (HDR) prostate cancer brachytherapy in comparison to conventional dose-volume based optimization. Methods: The quality of 12 clinical HDR brachytherapy implants for prostate utilizing HIPO (Hybrid Inverse Planning Optimization) is compared with alternative plans, which were produced through inverse planning using the generalized equivalent uniform dose (gEUD). All the common dose-volume indices for the prostate and the organs at risk were considered together with radiobiological measures. The clinical effectiveness of the different dose distributions was investigated by comparing dose volume histogram and gEUD evaluators. Results: Our results demonstrate the feasibility of gEUD-based inverse planning in HDR brachytherapy implants for prostate. A statistically significant decrease in D{sub 10} or/and final gEUD values for the organs at risk (urethra, bladder, and rectum) was found while improving dose homogeneity or dose conformity of the target volume. Conclusions: Following the promising results of gEUD-based optimization in intensity modulated radiation therapy treatment optimization, as reported in the literature, the implementation of a similar model in HDR brachytherapy treatment plan optimization is suggested by this study. The potential of improved sparing of organs at risk was shown for various gEUD-based optimization parameter protocols, which indicates the ability of this method to adapt to the user's preferences.

  17. Determination of the dose of traffic in HDR brachytherapy with ALANINE/R PE technique

    International Nuclear Information System (INIS)

    Guzman Calcina, C. S.; Chen, F.; Almeida, A. de; Baffa, O.

    2001-01-01

    It determines, experimentally, the dose of traffic in brachytherapy for High Dose Rate (HDR), using for the first-time the Electronic Paramagnetic Resonance (EPR) technique with alanine detectors. The value obtained is the published next to obtained using lithium fluoride thermoluminescent dosimeters [es

  18. Prediction of HDR quality by combining perceptually transformed display measurements with machine learning

    Science.gov (United States)

    Choudhury, Anustup; Farrell, Suzanne; Atkins, Robin; Daly, Scott

    2017-09-01

    We present an approach to predict overall HDR display quality as a function of key HDR display parameters. We first performed subjective experiments on a high quality HDR display that explored five key HDR display parameters: maximum luminance, minimum luminance, color gamut, bit-depth and local contrast. Subjects rated overall quality for different combinations of these display parameters. We explored two models | a physical model solely based on physically measured display characteristics and a perceptual model that transforms physical parameters using human vision system models. For the perceptual model, we use a family of metrics based on a recently published color volume model (ICT-CP), which consists of the PQ luminance non-linearity (ST2084) and LMS-based opponent color, as well as an estimate of the display point spread function. To predict overall visual quality, we apply linear regression and machine learning techniques such as Multilayer Perceptron, RBF and SVM networks. We use RMSE and Pearson/Spearman correlation coefficients to quantify performance. We found that the perceptual model is better at predicting subjective quality than the physical model and that SVM is better at prediction than linear regression. The significance and contribution of each display parameter was investigated. In addition, we found that combined parameters such as contrast do not improve prediction. Traditional perceptual models were also evaluated and we found that models based on the PQ non-linearity performed better.

  19. Comparing subjective and objective quality assessment of HDR images compressed with JPEG-XT

    DEFF Research Database (Denmark)

    Mantel, Claire; Ferchiu, Stefan Catalin; Forchhammer, Søren

    2014-01-01

    In this paper a subjective test in which participants evaluate the quality of JPEG-XT compressed HDR images is presented. Results show that for the selected test images and display, the subjective quality reached its saturation point starting around 3bpp. Objective evaluations are obtained...

  20. Quality assurance of HDR 192Ir sources using a Fricke dosimeter.

    Science.gov (United States)

    Austerlitz, C; Mota, H; Almeida, C E; Allison, R; Sibata, C

    2007-04-01

    A prototype of a Fricke dosimetry system consisting of a 15 x 15 x 15 cm3 water phantom made of Plexiglas and a 11.3-ml Pyrex balloon fitted with a 0.2 cm thick Pyrex sleeve in its center was created to assess source strength and treatment planning algorithms for use in high dose rate (HDR) 192Ir afterloading units. In routine operation, the radioactive source is positioned at the end of a sleeve, which coincides with the center of the spherical balloon that is filled with Fricke solution, so that the solution is nearly isotropically irradiated. The Fricke system was calibrated in terms of source strength against a reference well-type ionization chamber, and in terms of radial dose by means of an existing algorithm from the HDR's treatment planning system. Because the system is based on the Fricke dosimeter itself, for a given type and model of 192Ir source, the system needs initial calibration but no recalibration. The results from measurements made over a 10 month period, including source decay and source substitutions, have shown the feasibility of using such a system for quality control (QC) of HDR afterloading equipment, including both the source activity and treatment planning parameters. The benefit of a large scale production and the use of this device for clinical HDR QC audits via mail are also discussed.

  1. Photometric and Colorimeric Comparison of HDR and Spctrally Resolved Rendering Images

    DEFF Research Database (Denmark)

    Amdemeskel, Mekbib Wubishet; Soreze, Thierry Silvio Claude; Thorseth, Anders

    2017-01-01

    In this paper, we will demonstrate a comparison between measured colorimetric images, and simulated images from a physics based rendering engine. The colorimetric images are high dynamic range (HDR) and taken with a luminance and colour camera mounted on a goniometer. For the comparison, we have ...

  2. Quality control and performance evaluation of microselectron HDR machine over 30 months

    International Nuclear Information System (INIS)

    Balasubramanian, N.; Annex, E.H.; Sunderam, N.; Patel, N.P.; Kaushal, V.

    2008-01-01

    To assess the performance evaluation of Microselectron HDR machine the standard quality control and quality assurance checks were carried out after each loading of new 192 Ir brachytherapy source In the machine. Total 9 loadings were done over a period of 30 months

  3. Implementation of the technique of partial irradiation accelerated the breast with high doses (HDR) brachytherapy

    International Nuclear Information System (INIS)

    Molina Lopez, M. Y.; Pardo Perez, E.; Castro Novais, J.; Martinez Ortega, J.; Ruiz Maqueda, S.; Cerro Penalver, E. del

    2013-01-01

    The objective of this work is presents procedure carried out in our Centre for the implementation of the accelerated partial breast irradiation (APBI, accelerated partial-breast irradiation) with high-rate brachytherapy (HDR), using plastic tubes as applicators. Carried out measures, the evaluation of the dosimetric parameters analyzing and presenting the results. (Author)

  4. HDR brachytherapy in carcinoma of cervix: initial experience at AWARE hospitals

    International Nuclear Information System (INIS)

    Rajendran, M.; Reddy, K.D.; Reddy, R.M.; Reddy, J.M.; Reddy, B.V.N.; Kiran Kumar; Gopi, S.; Dharaniraj; Janardhanan

    2002-01-01

    High dose rate (HDR) brachytherapy is well established in the management of gynaecological malignancies. A report on the initial results of one and half year experience with a consistent dose/fractionation schedule and procedure of planning with delivery of treatment schedule is presented

  5. Mixed integer programming improves comprehensibility and plan quality in inverse optimization of prostate HDR Brachytherapy

    NARCIS (Netherlands)

    Gorissen, B.L.; den Hertog, D.; Hoffmann, A.L.

    2013-01-01

    Current inverse treatment planning methods that optimize both catheter positions and dwell times in prostate HDR brachytherapy use surrogate linear or quadratic objective functions that have no direct interpretation in terms of dose-volume histogram (DVH) criteria, do not result in an optimum or

  6. Needle displacement during HDR brachytherapy in the treatment of prostate cancer

    International Nuclear Information System (INIS)

    Damore, Steven J.; Syed, A.M. Nisar; Puthawala, Ajmel A.; Sharma, Anil

    2000-01-01

    Purpose: We used clinical patient data to examine implant displacement between high dose rate (HDR) brachytherapy fractions for prostate cancer to determine its impact on treatment delivery. Materials and Methods: We analyzed the verification films taken prior to each fraction for 96 consecutive patients treated with HDR brachytherapy boosts as part of their radiation therapy for definitive treatment of organ-confined prostate cancer at our institution. Patients were treated with 18-24 Gy in 4 fractions of HDR delivered in 40 hours followed by 36-39.6 Gy external beam radiation to the prostate. We determined the mean and maximum displacement distances of marker seeds placed in the prostate and of the implanted needles between HDR fractions. Results: Mean and maximum displacement distances between fractions were documented up to 7.6 mm and 28.5 mm, respectively, for the implant needles and 3.6 mm and 11.4 mm, respectively, for the gold marker seeds. All displacement of implant needles occurred in the caudal direction. At least 1 cm caudal displacement of needles occurred prior to 15.5% all fractions. Manual adjustment of needles was required prior to 15% of fractions, and adjustment of the CLP only was required in 24%. Most of the displacement for both the marker seeds and needles occurred between the first and second fractions. Conclusions: There is significant caudal displacement of interstitial implant needles between HDR fractions in our prostate cancer patients. Obtaining verification films and making adjustments in the treatment volume prior to each fraction is necessary to avoid significant inaccuracies in treatment delivery

  7. SU-E-T-574: Fessiblity of Using the Calypso System for HDR Interstitial Catheter Reconstruction

    International Nuclear Information System (INIS)

    Li, J S; Ma, C

    2014-01-01

    Purpose: It is always a challenge to reconstruct the interstitial catheter for high dose rate (HDR) brachytherapy on patient CT or MR images. This work aims to investigate the feasibility of using the Calypso system (Varian Medical, CA) for HDR catheter reconstruction utilizing its accuracy on tracking the electromagnetic transponder location. Methods: Experiment was done with a phantom that has a HDR interstitial catheter embedded inside. CT scan with a slice thickness of 1.25 mm was taken for this phantom with two Calypso beacon transponders in the catheter. The two transponders were connected with a wire. The Calypso system was used to record the beacon transponders’ location in real time when they were gently pulled out with the wire. The initial locations of the beacon transponders were used for registration with the CT image and the detected transponder locations were used for the catheter path reconstruction. The reconstructed catheter path was validated on the CT image. Results: The HDR interstitial catheter was successfully reconstructed based on the transponders’ coordinates recorded by the Calypso system in real time when the transponders were pulled in the catheter. After registration with the CT image, the shape and location of the reconstructed catheter are evaluated against the CT image and the result shows an accuracy of 2 mm anywhere in the Calypso detectable region which is within a 10 cm X 10 cm X 10 cm cubic box for the current system. Conclusion: It is feasible to use the Calypso system for HDR interstitial catheter reconstruction. The obstacle for its clinical usage is the size of the beacon transponder whose diameter is bigger than most of the interstitial catheters used in clinic. Developing smaller transponders and supporting software and hardware for this application is necessary before it can be adopted for clinical use

  8. Effectiveness of two different HDR brachytherapy regimens with the same BED value in cervical cancer

    Directory of Open Access Journals (Sweden)

    Rajesh Vashistha

    2010-07-01

    Full Text Available Purpose: To analyze the effectiveness of biologically effective dose (BED in two different regimens of HDR brachytherapy keeping the same total BED to point A and to compare the relationship of overall treatment time in terms of local control and bladder and rectal complications.Material and methods: The study included two groups comprising a total of 90 cervical cancer patients who underwent external beam radiotherapy (EBRT followed by HDR intracavitary brachytherapy (ICBT. EBRT treatment was delivered by a Co-60 teletherapy unit to a prescribed dose of 45 Gy with 1.8 Gy per fraction in 25 fractions over a period of five weeks. Parallel opposed anterior–posterior (AP/PA fields with no central shielding were used, followed by the HDR ICBT dose, to point A, of either two fractions of 9.5 Gy with a gap of 10 days, or three fractions of 7.5 Gy with a gap of 7 days between the fractions. Gemcitabine (dose of 150 mg/m2 was given weekly to all the patients as a radiosensitizer. The calculate BED3 to point A was almost the same in both groups to keep the same late complication rates. The doses, and BED10 and BED3, were calculated at different bladder and rectal point as well as at the lymphatictrapezoid points. During and after treatment patients were evaluated for local control and complications for 24 months.Results and Conclusions: Doses and BEDs at different bladder, rectal and lymphatic trapezoid points, local control, and complications in both HDR ICBT groups did not have statistically significant differences (p > 0.05. Both HDR ICBT schedules are well tolerable and equally effective.

  9. Perioperative high dose rate (HDR brachytherapy in unresectable locally advanced pancreatic tumors

    Directory of Open Access Journals (Sweden)

    Brygida Białas

    2011-07-01

    Full Text Available Purpose: The aim of the study was to present an original technique of catheter implantation for perioperative HDR-Ir192 brachytherapy in patients after palliative operations of unresectable locally advanced pancreatic tumors and to estimate the influence of perioperative HDR-Ir192 brachytherapy on pain relief in terminal pancreatic cancer patients. Material and methods: Eight patients with pancreatic tumors located in the head of pancreas underwent palliative operations with the use of HDR-Ir192 brachytherapy. All patients qualified for surgery reported pain of high intensity and had received narcotic painkillers prior to operation. During the last phase of the surgery, the Nucletron® catheters were implanted in patients to prepare them for later perioperative brachytherapy. Since the 6th day after surgery HDR brachytherapy was performed. Before each brachytherapy fraction the location of implants were checked using fluoroscopy. A fractional dose was 5 Gy and a total dose was 20 Gy in the area of radiation. A comparative study of two groups of patients (with and without brachytherapy with stage III pancreatic cancer according to the TNM scale was taken in consideration. Results and Conclusions: The authors claim that the modification of catheter implantation using specially designed cannula, facilitates the process of inserting the catheter into the tumor, shortens the time needed for the procedure, and reduces the risk of complications. Mean survival time was 5.7 months. In the group of performed brachytherapy, the mean survival time was 6.7 months, while in the group of no brachytherapy performed – 4.4 months. In the group of brachytherapy, only one patient increased the dose of painkillers in the last month of his life. Remaining patients took constant doses of medicines. Perioperative HDR-Ir192 brachytherapy could be considered as a practical application of adjuvant therapy for pain relief in patients with an advanced pancreatic cancer.

  10. Synthese und Charakterisierung wasserfreier Seltenerdmetall-Nitrate, -Acetate und -Oxyacetate

    OpenAIRE

    Heinrichs, Christina

    2013-01-01

    Durch thermische Entwässerung der Seltenerdmetall(SE)-Nitrat-Hydrate und der SE-Acetat-Hydrate im Argon-Strom/Vakuum konnten wasserfreie SE-Nitrate und SE-Nitrat-Monohydrate bzw. wasserfreie SE-Acetate erhalten werden. Es gelang zudem, SE-Oxyacetate durch thermische Zersetzung der SE-Acetate darzustellen. Des Weiteren wurde beim Erhitzen von Praseodym-Carbonat-Hydrat ein Pr-Carbonat-Hydroxid erhalten. Die Verbindungen wurden mittels Röntgenpulverdiffraktometrie und an ausgewählten Beispielen ...

  11. Editorial: Informationstechnische Bildung und Medienerziehung

    Directory of Open Access Journals (Sweden)

    Annemarie Hauf-Tulodziecki

    2001-10-01

    Full Text Available Die schulische Medienerziehung bzw. die Medienbildung hat ihre derzeit hohe öffentliche Aufmerksamkeit nicht zuletzt der Tatsache zu verdanken, dass gerade die so genannten «Neuen Medien» - heute oft mit den Schlagworten «Multimedia» oder «Internet» abgekürzt - wichtige Erziehungs- und Bildungsmassnahmen erforderlich machen. In der öffentlichen Diskussion gehören inhaltliche Kurzschlüsse zur Tagesordnung: Wenn von «Medienkompetenz» die Rede ist, verbirgt sich dahinter häufig nur ein «Internetführerschein». Diese Beobachtung ärgert nicht nur Medienpädagogen, sondern auch Vertreter einer Informationstechnischen Bildung (1, da berechtigte pädagogische Ansprüche beider Gruppen wenig Beachtung finden. Mittlerweile gibt es eine Reihe von Empfehlungen von BLK und KMK zu diesem Thema, in denen zudem deutlich auf die wechselseitigen Bezüge hingewiesen werden. Die wachsende Bedeutung des Mediums Computer und die weiter zunehmende Digitalisierung traditioneller Medien erfordert sowohl für die Medienerziehung als auch für die Informatische Bildung eine Weiterentwicklung ihrer Ziele und Inhalte. Die Gesellschaft für Informatik e.V. hat 1999 in ihrer Empfehlung «Informatische Bildung und Medienerziehung» aus ihrer Perspektive dargestellt, welche Aufgaben auf die Medienerziehung zukommen, wenn auch die Informations- und Kommunikationstechnologien bzw. die computerbasierten Medien in einer angemessenen Form thematisiert werden sollen. Erste praktische Ansätze, Inhalte aus beiden Bereichen bewusst zusammenzuführen, auch unter einer gemeinsamen Fach- oder Kursbezeichnung, sind häufig additiv und orientieren sich – trotz vorhandener Überschneidungen – an den etablierten medienpädagogischen oder an den informatischen Unterrichtsprinzipien. In dem vorliegenden Themenheft wird aus einer übergeordneten, medienpädagogischen Perspektive die Frage gestellt, wie eine konsistente Weiterentwicklung der Medienerziehung unter angemessener

  12. DRUCKFLAMM - Investigation on combustion and hot gas cleanup in pulverized coal combustion systems. Final report; DRUCKFLAMM - Untersuchungen zur Verbrennung und Heissgasreinigung bei der Druckkohlenstaubfeuerung. Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Hein, K.R.G.; Benoehr, A.; Schuermann, H.; Stroehle, J.; Klaiber, C.; Kuhn, R.; Maier, J.; Schnell, U.; Unterberger, S.

    2001-07-01

    facility of the Technical University of Aachen. (orig.) [German] Die Bestrebungen einer effizienten und schadstoffarmen Energieversorgung fuehrten bei der Kohleverbrennung zur Entwicklung von kohlebasierten Kombikraftwerken, die im Vergleich zum konventionellen Kondensationskraftwerk eine deutliche Anhebung des Nettowirkungsgrades erlauben. Eines der Kombikraftwerkskonzepte auf Kohlebasis stellt die Druckkohlenstaubfeuerung dar, die gegenueber den anderen Konzepten das hoechste Wirkungsgradpotential aufweist. Das Ziel dieses Forschungsvorhabens war die Gewinnung gesicherter Erkenntnisse hinsichtlich des Feuerungsverhaltens von Kohle in einer Druckkohlenstaubfeuerung. Es wurden an einem Druckflugstromreaktor detaillierte Untersuchungen zur Brennstoffumsetzung und zum Partikelverhalten, zur Schadstoffbildung und zum Werkstoffverhalten unter Bedingungen der Druckkohlenstaubfeuerung durchgefuehrt. Im Laufe des Forschungsvorhabens wurden einige neue Messtechniken eingesetzt und teilweise auch angeschafft, wie zum Beispiel ein Zwei- Farb-Pyrometer zur simultanen Erfassung von Partikeloberflaechentemperatur und Partikeldurchmesser von brennenden Brennstoffpartikeln. Parallel zu den experimentellen Untersuchungen wurde an der Erarbeitung neuer Berechnungsmodelle gearbeitet, um eine spaetere Feuerraumsimulation fuer ein verbessertes Scale-Up zu ermoeglichen. Die am Druckflugstromreaktor gewonnenen Ergebnisse zeigen, dass der erhoehte Systemdruck sich auf sehr viele Verbrennungsmechanismen stark auswirkt, so konnte eine schnellere Brennstoffumsetzung und gleichzeitig verminderte Stickoxid- und Alkaligasemission nachgewiesen werden. Die Werkstoffuntersuchungen zeigten, dass die aufgrund der sehr hohen Verbrennungstemperaturen benoetigten Keramikwerkstoffe sehr empfindlich gegenueber Verschlackung und schnellen Temperaturwechseln sind, weshalb hinsichtlich der benoetigten Standzeiten in einer zu realisierenden Druckbrennkammer noch erheblicher Entwicklungsbedarf besteht. Hinsichtlich

  13. GROSSSPRENGUN UND MIKROSEISMIK

    Directory of Open Access Journals (Sweden)

    E. HARDTWIG

    1956-06-01

    Full Text Available Uéber die bei Sprengungen entstelienden Periodenspektren ist noch
    wenig bekannt, trotzdem in jedem Jahre Tausende von Sprengungen
    registriert werden. Die wenigen Arbeiten, die zu diesem Gegenstand erscliienen
    sind, stellen nur erste Versuche dar, den Aufbau der Spektren
    zu erklaren. Wàhrend etwa George Morris (* vorwiegend die bei
    Sprengungen si eh abspielenden Detonationsvorgànge zum Ausgangspunkt
    der Untersuchung macht, ist es bei IT. Menzel (2 die Interferenz von
    Primàrwelle und reflektierter Welle, deren Einfluss auf die Gestalt
    des Spektrums untersucht wird.

  14. Enterprise Portals und Enterprise Application Integration - Begriffsbestimmung und Integrationskonzeptionen

    OpenAIRE

    Schelp, Joachim; Winter, Robert

    2002-01-01

    Unter den Stichworten »Enterprise Portals« und »Enterprise Application Integration« werden neue Herausforderungen an die Applikationsarchitektur der Unternehmungen gestellt. Bei beiden spielt die Integration vorhandener und das Einfügen neuer Applikationen eine große Rolle. Beiden Themen ist gemein, dass sie die Diskussion bestimmter technischer Konzepte aus den vergangenen Jahren fortsetzen: Portale stellen das moderne Frontend dar, über das die verschiedenen E-Business-Konzepte umgesetzt we...

  15. Dosimetry experience of 192IR sources used In HDR brachytherapy for cervical cancer

    International Nuclear Information System (INIS)

    Daci, Lulzime; Myrku, Rodina Cela

    2013-01-01

    Purpose/Objective: The 192IR Sources are the most commonly used in radiotherapy treatments HDR worldwide. According to international recommendations on quality assurance in HDR brachytherapy, an acceptance test based on the determination of the source strength of any new source shall be carried out before first application to verify the manufacturer’s calibration data. The present paper gives the experimental determination of the source strength for our brachytherapy sources used until now in brachytherapy treatments. Materials/Methods: At Mother Teresa University Hospital we have a cost-effective gynecological brachytherapy unit from Eckert & Ziegler BEBIG named GyneSource® that is a five channel HDR after loader equipped with an 192IR source. The software used is HDR plus™ 2.5 that delivers an optimized treatment plan and makes the process especially fast and we use intracavitary BEBIG applicators. From April 2009 up to December 2012, we have imported nine HDR 192IR Sources. The exchange of the source and acceptance test is done by the physicist of the clinic once the source is imported. The measurements are done with a Well-type ionization chamber HDR1000 Plus and the electrometer used is MAX4000. Only seven sources are compared as we miss the dosimetry data of the first source, and the forth source was not measured and not used because the machine was not working in that time. Results/Conclusions: Eight sources were accepted for clinically use as the measurement were within the tolerance. The source number four with e deviation of -1.92% has been double checked compared with a free in-air measurement with farmer type chamber that gave a deviation to source certificate of 4% that is still inside the tolerance to accept a source for clinical use. The deviations of measured Air Kerma rate to the value of the sources certificates of all our used 192IR sources are less than 2%, which are within the tolerance. The checked value of updated source strength in

  16. Cyberbullying und Empathie : affektive, kognitive und medienbasierte Empathie im Kontext von Cyberbullying im Kindes- und Jugendalter

    OpenAIRE

    Pfetsch, Jan; Müller, Christin R.; Ittel, Angela

    2014-01-01

    "Bei medial vermittelter Kommunikation sinkt sowohl die Hemmschwelle für aggressive Verhaltensweisen wie Cyberbullying als auch die Wahrscheinlichkeit empathischer Reaktionen. Im Fokus der vorliegenden Studie mit 979 Schülerinnen und Schülern der 4.-8. Klassen (M=12.01, SD=1.68 Jahre, 55% weiblich) stand die Frage, ob Cyberbullies geringere Ausprägungen für affektive, kognitive und medienbasierte Empathie aufweisen als Unbeteiligte. Empathie wurde im Selbst- und Peerbericht erhoben. Hypothese...

  17. The Oryza sativa Regulator HDR1 Associates with the Kinase OsK4 to Control Photoperiodic Flowering.

    Directory of Open Access Journals (Sweden)

    Xuehui Sun

    2016-03-01

    Full Text Available Rice is a facultative short-day plant (SDP, and the regulatory pathways for flowering time are conserved, but functionally modified, in Arabidopsis and rice. Heading date 1 (Hd1, an ortholog of Arabidopsis CONSTANS (CO, is a key regulator that suppresses flowering under long-day conditions (LDs, but promotes flowering under short-day conditions (SDs by influencing the expression of the florigen gene Heading date 3a (Hd3a. Another key regulator, Early heading date 1 (Ehd1, is an evolutionarily unique gene with no orthologs in Arabidopsis, which acts as a flowering activator under both SD and LD by promoting the rice florigen genes Hd3a and RICE FLOWERING LOCUST 1 (RFT1. Here, we report the isolation and characterization of the flowering regulator Heading Date Repressor1 (HDR1 in rice. The hdr1 mutant exhibits an early flowering phenotype under natural LD in a paddy field in Beijing, China (39°54'N, 116°23'E, as well as under LD but not SD in a growth chamber, indicating that HDR1 may functionally regulate flowering time via the photoperiod-dependent pathway. HDR1 encodes a nuclear protein that is most active in leaves and floral organs and exhibits a typical diurnal expression pattern. We determined that HDR1 is a novel suppressor of flowering that upregulates Hd1 and downregulates Ehd1, leading to the downregulation of Hd3a and RFT1 under LDs. We have further identified an HDR1-interacting kinase, OsK4, another suppressor of rice flowering under LDs. OsK4 acts similarly to HDR1, suppressing flowering by upregulating Hd1 and downregulating Ehd1 under LDs, and OsK4 can phosphorylate HD1 with HDR1 presents. These results collectively reveal the transcriptional regulators of Hd1 for the day-length-dependent control of flowering time in rice.

  18. A segmentation and point-matching enhanced efficient deformable image registration method for dose accumulation between HDR CT images

    International Nuclear Information System (INIS)

    Zhen, Xin; Chen, Haibin; Zhou, Linghong; Yan, Hao; Jiang, Steve; Jia, Xun; Gu, Xuejun; Mell, Loren K; Yashar, Catheryn M; Cervino, Laura

    2015-01-01

    Deformable image registration (DIR) of fractional high-dose-rate (HDR) CT images is challenging due to the presence of applicators in the brachytherapy image. Point-to-point correspondence fails because of the undesired deformation vector fields (DVF) propagated from the applicator region (AR) to the surrounding tissues, which can potentially introduce significant DIR errors in dose mapping. This paper proposes a novel segmentation and point-matching enhanced efficient DIR (named SPEED) scheme to facilitate dose accumulation among HDR treatment fractions. In SPEED, a semi-automatic seed point generation approach is developed to obtain the incremented fore/background point sets to feed the random walks algorithm, which is used to segment and remove the AR, leaving empty AR cavities in the HDR CT images. A feature-based ‘thin-plate-spline robust point matching’ algorithm is then employed for AR cavity surface points matching. With the resulting mapping, a DVF defining on each voxel is estimated by B-spline approximation, which serves as the initial DVF for the subsequent Demons-based DIR between the AR-free HDR CT images. The calculated DVF via Demons combined with the initial one serve as the final DVF to map doses between HDR fractions. The segmentation and registration accuracy are quantitatively assessed by nine clinical HDR cases from three gynecological cancer patients. The quantitative analysis and visual inspection of the DIR results indicate that SPEED can suppress the impact of applicator on DIR, and accurately register HDR CT images as well as deform and add interfractional HDR doses. (paper)

  19. A segmentation and point-matching enhanced efficient deformable image registration method for dose accumulation between HDR CT images

    Science.gov (United States)

    Zhen, Xin; Chen, Haibin; Yan, Hao; Zhou, Linghong; Mell, Loren K.; Yashar, Catheryn M.; Jiang, Steve; Jia, Xun; Gu, Xuejun; Cervino, Laura

    2015-04-01

    Deformable image registration (DIR) of fractional high-dose-rate (HDR) CT images is challenging due to the presence of applicators in the brachytherapy image. Point-to-point correspondence fails because of the undesired deformation vector fields (DVF) propagated from the applicator region (AR) to the surrounding tissues, which can potentially introduce significant DIR errors in dose mapping. This paper proposes a novel segmentation and point-matching enhanced efficient DIR (named SPEED) scheme to facilitate dose accumulation among HDR treatment fractions. In SPEED, a semi-automatic seed point generation approach is developed to obtain the incremented fore/background point sets to feed the random walks algorithm, which is used to segment and remove the AR, leaving empty AR cavities in the HDR CT images. A feature-based ‘thin-plate-spline robust point matching’ algorithm is then employed for AR cavity surface points matching. With the resulting mapping, a DVF defining on each voxel is estimated by B-spline approximation, which serves as the initial DVF for the subsequent Demons-based DIR between the AR-free HDR CT images. The calculated DVF via Demons combined with the initial one serve as the final DVF to map doses between HDR fractions. The segmentation and registration accuracy are quantitatively assessed by nine clinical HDR cases from three gynecological cancer patients. The quantitative analysis and visual inspection of the DIR results indicate that SPEED can suppress the impact of applicator on DIR, and accurately register HDR CT images as well as deform and add interfractional HDR doses.

  20. Evaluation of the Kerma at the entrance of the labyrin thin in facilities with Co-60 HDR brachytherapy

    International Nuclear Information System (INIS)

    Pujades, M. C.; Granero, D.; Ballester, F.; Perez-Calatayud, J.; Vijande, J.

    2013-01-01

    The purpose of this study is to evaluate the kerma's collision at the entrance of the labyrinth adapting the methodology of the NCRP-151 to a bunker of brachytherapy with Co-60, similar to the one carried out in a previous work with HDR Ir-192. To validate the result is simulated using techniques Monte Carlo (MC) two typical designs of HDR with Co-60 bunker. (Author)

  1. Jung und Alt im Dialog

    Directory of Open Access Journals (Sweden)

    Caroline Baetge

    2012-04-01

    Full Text Available Rezension zu: Kupser, Thomas, und Ida Pöttinger, Hrsg. 2011. Mediale Brücken: Generationen im Dialog durch aktive Medienarbeit. Gesellschaft - Altern - Medien 3. München: kopaed.

  2. Frauen in Philosophie und Wissenschaft

    Directory of Open Access Journals (Sweden)

    Regina Harzer

    2006-03-01

    Full Text Available Der von Brigitte Doetsch herausgegebene Band präsentiert die aktuelle Feministische Philosophie und sammelt Beiträge, die Einblick geben in den gegenwärtigen Forschungsstand, wie ihn „Philosophinnen im dritten Jahrtausend“ erreicht haben. Insgesamt neun, zum Teil interdisziplinär ausgerichtete Arbeiten werden vorgestellt. Das Themenspektrum ist weit: Geschichte der Philosophie; Politische Philosophie und Naturphilosophie; Epistemologie; Biopolitik und Bioethik als Bereiche praktischer Philosophie; Forschung über Geschlechterverhältnisse. Alle Beiträge gehen zurück auf eine Vortragsreihe des Braunschweiger Zentrums für Gender Studies (www.genderzentrum.de. Leser/-innen erhalten einen guten Überblick über die aktuelle Frauenforschung aus der Sicht theoretischer und praktischer Philosophie.

  3. Gesundheit und Pflege im Alter

    OpenAIRE

    Pfaff, Martin

    1989-01-01

    Gesundheit und Pflege im Alter : d. Gesundheitsreformgesetz (GRG) ; Möglichkeiten, Grenzen u. weitere Vorschläge / Martin Pfaff ; Klaus Deimer. - In: Expertengespräch "Pflege in der Familie". - Augsburg, 1989. - Getr. Zählung

  4. Editorial: Computerspiele und Videogames in formellen und informellen Bildungskontexten

    Directory of Open Access Journals (Sweden)

    Johannes Fromme

    2008-01-01

    Full Text Available Computer- und Videospiele sind heute ein selbstverständlicher Bestandteil der Lebenswelt vieler Kinder und Jugendlicher, aber auch von (jüngeren Erwachsenen, die mit diesen neuen Medien aufgewachsen sind. Lange Zeit haben elektronische Bildschirmspiele allenfalls sporadische Beachtung gefunden. Weder in der Medienforschung oder Medienpädagogik noch in der breiteren Öffentlichkeit waren sie ein Gegenstand von breiterem Interesse.* In den letzten knapp zehn Jahren sind Video- und Computerspiele allerdings zunehmend in den Fokus der Aufmerksamkeit gerückt. Dabei sind in der massenmedial vermittelten Öffentlichkeit vor allem Amokläufe in Schulen in einen direkten Zusammenhang mit den Vorlieben (der Täter für bestimmte Computerspiele gebracht worden. Die auch von prominenten Politikern aufgegriffene These lautete, dass gewalthaltige Spiele wie der First Person Shooter «Counterstrike» ein virtuelles Trainingsprogramm für das Töten und daher als wesentliche Ursache solcher Schulmassaker anzusehen seien. Auf der Basis dieser kausalen Wirkungsannahmen bzw. der unterstellten negativen Lern- und Trainingseffekte werden seither immer wieder Forderungen nach einem Verbot solcher «Killerspiele» oder gar nach der Verbannung aller Bildschirmmedien aus den Kinderzimmern abgeleitet. Neben solcher skandalisierter Thematisierung ist aber zunehmend auch eine nüchterne wissenschaftliche Auseinandersetzung zu konstatieren. So haben sich seit Beginn des neuen Jahrtausends die «digital game studies» als interdisziplinäres Forschungsfeld etabliert. Im Jahr 2000 wurde innerhalb der Gesellschaft für Medienwissenschaft z.B. die AG Games gebildet, die sich zu einem wichtigen deutschsprachigen Forum für die wissenschaftliche Beschäftigung mit Computerspielen entwickelt hat, und im Jahr 2002 entstand die internationale Digital Games Research Association (DiGRA, die im September 2009 ihre vierte grosse Konferenz nach 2003, 2005 und 2007 durchgeführt hat

  5. Surface dose characterisation of the Varian Ir-192 HDR conical surface applicator set with a vertically orientated source

    Energy Technology Data Exchange (ETDEWEB)

    Buchauer, Konrad; Henke, Guido; Schiefer, Hans; Plasswilm, Ludwig [Kantonsspital St. Gallen, Department of Radiation Oncology, St. Gallen (Switzerland)

    2014-12-15

    etabliertes Mittel um mit Ir-192 HDR-Brachytherapie nichtmelanomatoese Hautkrebserkrankungen mit hohen Tumorkontrollraten zu behandeln. In dieser Arbeit wird eine hochaufloesende Analyse der Oberflaechendosis eines Varian-Varisource-GammaMed+ IX-Afterloader-Konus-Applikatorsatzes des vertikalen Typs dargestellt. Analyse der Oberflaechendosisverteilung des Applikatorsatzes im Hinblick auf Unregelmaessigkeiten, die fuer aehnliche Applikatoren bereits berichtet wurden. Weiterhin wird untersucht, ob Applikatoren des vertikalen Typs zusaetzliche Verfahren als Ergaenzung der aktuell vorgeschlagenen Methoden zur Verifikation des Dosisoutputs von konischen Oberflaechenapplikatoren benoetigen. Die Verifikation der absoluten Dosis wird nach Herstellerangaben durchgefuehrt. Die Dosisverteilung an der Oberflaeche wird zusaetzlich mit Gafchromic-EBT3-Filmdosimetrie bestimmt. Der Begriff ''therapeutische Dosis'' ist in dieser Arbeit mit 85 % der verschriebenen Dosis definiert. Zehn ausgewertete Applikatoren zeigen Unterdosierungen in der Applikatormitte, mit einer mittlere Groesse von 2,0 mm x 3,6 mm (± 0,6 mm), dosimetrisch deutlich unter 85 % der verschriebenen Dosis. Die Unterdosierung liegt 2,2 mm (1,4-2,7 mm) seitlich der Zentralachse und verursacht eine generelle Asymmetrie in der Dosisverteilung. Ein Schiefstand von 8 (± 1 ) wurde fuer die verwendete Quelle bestimmt. Eine um mehr als 15 % reduzierte Dosis in der Applikatormitte wurde bei Oberflaechenapplikatoren bislang nicht berichtet. Quellenschiefstand wurde als Parameter identifiziert, der die Handhabung dieser Oberflaechenapplikatoren und moeglicherweise den Therapieerfolg beeinflussen kann. Das beschriebene kleinraeumige Dosisartefakt kann systematischen Einfluss auf kammerbasierte Dosisverifikationsverfahren haben. Wir empfehlen daher bei der Applikatorkommissionierung eine zusaetzliche Absicherung mit Filmdosimetrie. (orig.)

  6. Professionalisierung und Doping im Sport

    OpenAIRE

    Wüterich, Christoph

    2004-01-01

    Der Beitrag untersucht Zusammenhänge zwischen der zunehmenden Professionalisierung des Sports und dem Anstieg von Dopingvergehen. Er zeigt, dass im historischen Vergleich beide Phänomene nicht neu sind, dass sich die Probleme aufgrund der steigenden Bedeutung des Leistungssports aber zugespitzt haben. Ausgehend von einer juristischen und sozioökonomischen Analyse der Anreize zu Doping werden Lösungsvorschläge entwickelt. The author analyzes the interdependencies between a growing commercia...

  7. Pepsi und Coca ewige Rivallen

    OpenAIRE

    POLJAKOW ANDREJ; POLJAKOW WLADIMIR

    2016-01-01

    Fast jeder kennt Pepsi und Coca. Man kann sie treffen praktisch in jedem Geschaeft. Dennoch nicht alle wissen, dass diese Firmen Erzrivallen sind und das ihre Rivallitaet sich seit Ewigkeit dauert. In meinem Artikel, welches ich in der Zusammenarbeit mit meinem Vater schrieb versuchte ich den Weg beider Firmen von der Gruendung bis heutigen Tagen zu beschreiben. Auf diesem Weg trafen sich technologische Aenderungen, Gerichtsverhandlungen, sowie geschickte Tricks. Wichtige Rolle spielt auch Ma...

  8. Tax Shield, Insolvenz und Zinsschranke

    OpenAIRE

    Arnold, Sven; Lahmann, Alexander; Schwetzler, Bernhard

    2010-01-01

    Dieser Beitrag analysiert den Wertbeitrag fremdfinanzierungsbedingter Steuervorteile (Tax Shield) unter realistischen Bedingungen (keine Negativsteuer; mögliche Insolvenz) für unterschiedliche Finanzierungspolitiken. Zusätzlich wird der Effekt der sogenannten Zinsschranke auf den Wert des Tax Shield ermittelt. Die Bewertung des Tax Shield mit und ohne Zinsschranke findet im einperiodigen Fall auf der Basis von Optionspreismodellen und im mehrperiodigen Fall auf der Basis von Monte Carlo Simul...

  9. Neue Shandite und Parkerite. Darstellung und röntgenographische Charakterisierung

    OpenAIRE

    Anusca, Irina

    2009-01-01

    Das Ziel dieser Arbeit war es, neue Verbindungen mit Shandit- und Parkeritstruktur zu darstellen und mittels röntgenographischen Methoden (Pulverdiffraktometrie und Einkristallanalyse), das thermische Verhalten durch DTA / DSC - Messungen und Elektronenmikroskopische Untersuchungen (REM, EDX) zu charakterisieren. Die vorliegende Arbeit ist wie folgt im zwei Themen gegliedert: Shandite und Parkerite. Der ersten Teil dieser Arbeit befaßt sich mit metallreichen ternären Chalkogeniden M3A2X2, ...

  10. Molekulargenetische Studie zur Verbreitung und Interaktion von PCV-2 bei Haus- und Wildschweinen

    OpenAIRE

    Bronnert, Bastian Balthasar Marcel

    2014-01-01

    Im Rahmen der vorliegenden Arbeit wurden Wild- und Hausschweingewebeproben aus den Jahren 2005 bis 2008 mittels nested PCR auf das Vorkommen von PCV-2 untersucht und die positiv getesteten Proben mittels Realtime PCR quantifiziert. Zusätzlich wurden die Proben im Institut für Pathologie der Justus-Liebig-Universität histologisch und immunhistologisch untersucht (Dissertation Hohloch). Ziel war es das Vorkommen von PCV-2 und die Häufigkeit von PCV-2 assoziierter Erkankungen bei Haus- und Wilds...

  11. Vom Stabilitäts- und Wachstumsgesetz zum Wohlstands- und Nachhaltigkeitsgesetz

    OpenAIRE

    Koll, Willi

    2016-01-01

    Das Stabilitäts- und Wachstumsgesetz wird bald 50 Jahre alt. Neue Herausforderungen erfordern eine Wirtschaftspolitik, die weit über die Ziele des Gesetzes hinausweist. Sie muss wirtschaftliches Wachstum und Stabilität mit den Zielen fiskalischer, sozialer und ökologischer Nachhaltigkeit auf nationaler und europäischer Ebene verbinden. Der Autor gibt einen Über blick über solche umfassenden Zielsysteme und leitet daraus ab, wie eine derart erweiterte wirtschaftspolitische Agenda in ein Wohlst...

  12. Interconnectedness und digitale Texte

    Directory of Open Access Journals (Sweden)

    Detlev Doherr

    2013-04-01

    Full Text Available Zusammenfassung Die multimedialen Informationsdienste im Internet werden immer umfangreicher und umfassender, wobei auch die nur in gedruckter Form vorliegenden Dokumente von den Bibliotheken digitalisiert und ins Netz gestellt werden. Über Online-Dokumentenverwaltungen oder Suchmaschinen können diese Dokumente gefunden und dann in gängigen Formaten wie z.B. PDF bereitgestellt werden. Dieser Artikel beleuchtet die Funktionsweise der Humboldt Digital Library, die seit mehr als zehn Jahren Dokumente von Alexander von Humboldt in englischer Übersetzung im Web als HDL (Humboldt Digital Library kostenfrei zur Verfügung stellt. Anders als eine digitale Bibliothek werden dabei allerdings nicht nur digitalisierte Dokumente als Scan oder PDF bereitgestellt, sondern der Text als solcher und in vernetzter Form verfügbar gemacht. Das System gleicht damit eher einem Informationssystem als einer digitalen Bibliothek, was sich auch in den verfügbaren Funktionen zur Auffindung von Texten in unterschiedlichen Versionen und Übersetzungen, Vergleichen von Absätzen verschiedener Dokumente oder der Darstellung von Bilden in ihrem Kontext widerspiegelt. Die Entwicklung von dynamischen Hyperlinks auf der Basis der einzelnen Textabsätze der Humboldt‘schen Werke in Form von Media Assets ermöglicht eine Nutzung der Programmierschnittstelle von Google Maps zur geographischen wie auch textinhaltlichen Navigation. Über den Service einer digitalen Bibliothek hinausgehend, bietet die HDL den Prototypen eines mehrdimensionalen Informationssystems, das mit dynamischen Strukturen arbeitet und umfangreiche thematische Auswertungen und Vergleiche ermöglicht. Summary The multimedia information services on Internet are becoming more and more comprehensive, even the printed documents are digitized and republished as digital Web documents by the libraries. Those digital files can be found by search engines or management tools and provided as files in usual formats as

  13. Management of a HDR brachytherapy system in the Hospital Juarez of Mexico

    International Nuclear Information System (INIS)

    Serrano F, A.G.; Ramirez R, G.; Gil G, R.; Azorin N, J.; Rivera M, T.

    2007-01-01

    Full text: In the Hospital Juarez of Mexico, it is carried out a project to implement a Brachytherapy system with high dose rate (HDR) through a Management quality program. In our work center this treatment modality in patients with cervicouterine cancer is used (CaCu), and constantly it is necessary to carry out improvements in the procedures, with the purpose of optimizing them and in consequence to complete the principles of the Radiological Protection, guaranteeing this way, an attention with the quality and safety, such that allow to diminish the risks to the patients and to assure that the received dose in critical organs it finds inside the permitted therapeutic limits, without commit the radiosensitive response of healthy organs. In this work an analysis of the implementation of this system is presented, detailing the procedures so much in the technological infrastructure like human and indicating the necessary technical and operative requirements to reach an adequate practice in HDR brachytherapy. (Author)

  14. Essential results of analyses accompanying the leak rate experiments E22 at HDR

    International Nuclear Information System (INIS)

    Grebner, H.; Hoefler, A.; Hunger, H.

    1994-01-01

    Under the E22 test group of phase III of the HDR safety programme, experiments were performed on the crack opening and leak rate behaviour of pipe components of smaller nominal bores. The experiments were complemented by computations, in particular verifications, to qualify the computation models as one of the main aims of the HDR safety programme. Most of the analyses to determine crack openings were performed by means of the finite-element method, including elastic-plastic materials behaviour and, complementarily, assessing engineering methods. The leak rate was calculated by means of separate 2-phase computation models. Altogether, it may be concluded from the structural and fracture mechanical experiments with pipes, elbows and branch pieces, that crack openings and incipient cracks at loading with internal pressure or bending moment can be described with good accuracy by means of the finite-element programme ADINA and the developed FE-models. (orig.) [de

  15. Dosimetric study of surface applicators of HDR brachytherapy GammaMed Plus equipment

    International Nuclear Information System (INIS)

    Reyes-Rivera, E.; Sosa, M.; Reyes, U.; Jesús Bernal-Alvarado, José de; Córdova, T.; Gil-Villegas, A.; Monzón, E.

    2014-01-01

    The cone type surface applicators used in HDR brachytherapy for treatment of small skin lesions are an alternative to be used with both electron beams and orthovoltage X-ray equipment. For a good treatment planning is necessary to know the dose distribution of these applicators, which can be obtained by experimental measurement and Monte Carlo simulation as well. In this study the dose distribution of surface applicators of 3 and 3.5 cm diameter, respectively of HDR brachytherapy GammaMed Plus equipment has been estimated using the Monte Carlo method, MCNP code. The applicators simulated were placed on the surface of a water phantom of 20 × 20 × 20 cm and the dose was calculated at depths from 0 to 3 cm with increments of 0.25 mm. The dose profiles obtained at depth show the expected gradients for surface therapy

  16. HDR Pathological Image Enhancement Based on Improved Bias Field Correction and Guided Image Filter

    Directory of Open Access Journals (Sweden)

    Qingjiao Sun

    2016-01-01

    Full Text Available Pathological image enhancement is a significant topic in the field of pathological image processing. This paper proposes a high dynamic range (HDR pathological image enhancement method based on improved bias field correction and guided image filter (GIF. Firstly, a preprocessing including stain normalization and wavelet denoising is performed for Haematoxylin and Eosin (H and E stained pathological image. Then, an improved bias field correction model is developed to enhance the influence of light for high-frequency part in image and correct the intensity inhomogeneity and detail discontinuity of image. Next, HDR pathological image is generated based on least square method using low dynamic range (LDR image, H and E channel images. Finally, the fine enhanced image is acquired after the detail enhancement process. Experiments with 140 pathological images demonstrate the performance advantages of our proposed method as compared with related work.

  17. Dosimetric study of surface applicators of HDR brachytherapy GammaMed Plus equipment

    Energy Technology Data Exchange (ETDEWEB)

    Reyes-Rivera, E., E-mail: eric-1985@fisica.ugto.mx, E-mail: modesto@fisica.ugto.mx, E-mail: uvaldoreyes@fisica.ugto.mx; Sosa, M., E-mail: eric-1985@fisica.ugto.mx, E-mail: modesto@fisica.ugto.mx, E-mail: uvaldoreyes@fisica.ugto.mx; Reyes, U., E-mail: eric-1985@fisica.ugto.mx, E-mail: modesto@fisica.ugto.mx, E-mail: uvaldoreyes@fisica.ugto.mx; Jesús Bernal-Alvarado, José de, E-mail: bernal@fisica.ugto.mx, E-mail: theo@fisica.ugto.mx, E-mail: gil@fisica.ugto.mx; Córdova, T., E-mail: bernal@fisica.ugto.mx, E-mail: theo@fisica.ugto.mx, E-mail: gil@fisica.ugto.mx; Gil-Villegas, A., E-mail: bernal@fisica.ugto.mx, E-mail: theo@fisica.ugto.mx, E-mail: gil@fisica.ugto.mx [División de Ciencias e Ingenierías, Universidad de Guanajuato, 37150 León, Gto. (Mexico); Monzón, E., E-mail: emonzon@imss.gob.mx [Unidad de Alta Especialidad No.1, Instituto Mexicano del Seguro Social, Léon, Gto. (Mexico)

    2014-11-07

    The cone type surface applicators used in HDR brachytherapy for treatment of small skin lesions are an alternative to be used with both electron beams and orthovoltage X-ray equipment. For a good treatment planning is necessary to know the dose distribution of these applicators, which can be obtained by experimental measurement and Monte Carlo simulation as well. In this study the dose distribution of surface applicators of 3 and 3.5 cm diameter, respectively of HDR brachytherapy GammaMed Plus equipment has been estimated using the Monte Carlo method, MCNP code. The applicators simulated were placed on the surface of a water phantom of 20 × 20 × 20 cm and the dose was calculated at depths from 0 to 3 cm with increments of 0.25 mm. The dose profiles obtained at depth show the expected gradients for surface therapy.

  18. Use of CT or MR dosimetry in high dose rate (HDR) brachytherapy for prostate cancer

    International Nuclear Information System (INIS)

    Liu, C.; Das, R.; See, A.; Duchesne, G.M.; Van Dyk, S.; Tai, K.H.

    2003-01-01

    Brachytherapy (BT) has, in recent years, become a well-utilised treatment option for prostate cancer. Tumour control probability relies on accurate dosimetry, which in turn relies on the accurate definition of the prostate gland. In external beam radiotherapy and BT, MRI has been shown to be a superior imaging modality when delineating the prostate gland especially at the apex. To date, data on MRI planning in prostate BT has focussed mainly on permanent interstitial implants. No data currently exists comparing MRI vs CT planning in HDR BT and its subsequent impact on prostate dosimetry. To determine the effects of MRI vs CT in HDR BT with respect to prostatic volumes and normal tissue doses, with the evaluations made using dose-volume histograms (DVH). Dosimetry parameters derived using CT and MRI (T2 weighted) scans of 11 patients who had received TRUS guided implants for HDR BT, were compared using the PlatoTM computer planning system. Treatment plans were generated on volumes marked by the same radiation oncologist for each patient. Comparison was made of the treatment plans (dosimetry) between: 1. CT generated plans; 2. CT generated plans assessed using MRI marked volumes and 3. MRI generated plans. We confirm the previously reported results that CT scans can overestimate prostatic volumes compared with MRI. Variations were noted in CT and MRI based plans that may allow improved sparing of the rectum and urethra when using MRI planning. The main disadvantages of using MRI scans are access to facilities as well as identifying a dummy source to adequately define the tips of our catheters. It is feasible to utilise MRI scans for HDR BT planning. The clearer definition of anatomical structures has added advantages when contouring the prostate

  19. IPIP: A new approach to inverse planning for HDR brachytherapy by directly optimizing dosimetric indices

    International Nuclear Information System (INIS)

    Siauw, Timmy; Cunha, Adam; Atamtuerk, Alper; Hsu, I-Chow; Pouliot, Jean; Goldberg, Ken

    2011-01-01

    Purpose: Many planning methods for high dose rate (HDR) brachytherapy require an iterative approach. A set of computational parameters are hypothesized that will give a dose plan that meets dosimetric criteria. A dose plan is computed using these parameters, and if any dosimetric criteria are not met, the process is iterated until a suitable dose plan is found. In this way, the dose distribution is controlled by abstract parameters. The purpose of this study is to develop a new approach for HDR brachytherapy by directly optimizing the dose distribution based on dosimetric criteria. Methods: The authors developed inverse planning by integer program (IPIP), an optimization model for computing HDR brachytherapy dose plans and a fast heuristic for it. They used their heuristic to compute dose plans for 20 anonymized prostate cancer image data sets from patients previously treated at their clinic database. Dosimetry was evaluated and compared to dosimetric criteria. Results: Dose plans computed from IPIP satisfied all given dosimetric criteria for the target and healthy tissue after a single iteration. The average target coverage was 95%. The average computation time for IPIP was 30.1 s on an Intel(R) Core TM 2 Duo CPU 1.67 GHz processor with 3 Gib RAM. Conclusions: IPIP is an HDR brachytherapy planning system that directly incorporates dosimetric criteria. The authors have demonstrated that IPIP has clinically acceptable performance for the prostate cases and dosimetric criteria used in this study, in both dosimetry and runtime. Further study is required to determine if IPIP performs well for a more general group of patients and dosimetric criteria, including other cancer sites such as GYN.

  20. 3-D conformal HDR brachytherapy as monotherapy for localized prostate cancer. A pilot study

    International Nuclear Information System (INIS)

    Martin, T.; Baltas, D.; Kurek, R.; Roeddiger, S.; Kontova, M.; Anagnostopoulos, G.; Skazikis, G.; Zamboglou, N.; Dannenberg, T.; Buhleier, T.; Tunn, U.

    2004-01-01

    Purpose: pilot study to evaluate feasibility, acute toxicity and conformal quality of three-dimensional (3-D) conformal high-dose-rate (HDR) brachytherapy as monotherapy for localized prostate cancer using intraoperative real-time planning. Patients and methods: between 05/2002 and 05/2003, 52 patients with prostate cancer, prostate-specific antigen (PSA) ≤ 10 ng/ml, Gleason score ≤ 7 and clinical stage ≤ T2a were treated. Median PSA was 6.4 ng/ml and median Gleason score 5. 24/52 patients had stage T1c and 28/52 stage T2a. For transrectal ultrasound-(TRUS-)guided transperineal implantation of flexible plastic needles into the prostate, the real-time HDR planning system SWIFT trademark was used. After implantation, CT-based 3-D postplanning was performed. All patients received one implant for four fractions of HDR brachytherapy in 48 h using a reference dose (D ref ) of 9.5 Gy to a total dose of 38.0 Gy. Dose-volume histograms (DVHs) were analyzed to evaluate the conformal quality of each implant using D 90 , D 10 urethra, and D 10 rectum. Acute toxicity was evaluated using the CTC (common toxicity criteria) scales. Results: median D 90 was 106% of D ref (range: 93-115%), median D 10 urethra 159% of D ref (range: 127-192%), and median D 10 rectum 55% of D ref (range: 35-68%). Median follow-up is currently 8 months. In 2/52 patients acute grade 3 genitourinary toxicity was observed. No gastrointestinal toxicity > grade 1 occurred. Conclusion: 3-D conformal HDR brachytherapy as monotherapy using intraoperative real-time planning is a feasible and highly conformal treatment for localized prostate cancer associated with minimal acute toxicity. Longer follow-up is needed to evaluate late toxicity and biochemical control. (orig.)

  1. Is there any place for LDR brachytherapy for head and neck carcinomas in HDR era?

    OpenAIRE

    Fijuth, Jacek

    2009-01-01

    In Poland, the classical LDR brachytherapy for head and neck carcinomas with Ir-192 wires or hairpins has completely disappeared some time ago after 30 years of successful clinical use. Can this technique be fully and safely replaced by HDR or PDR application? This option seems attractive because of new possibilities of 3D reconstruction and computer real-time treatment planning and optimization. However, in my opinion, long time is needed to get a clinical and scientific experience that has ...

  2. SU-E-J-270: Study of PET Response to HDR Brachytherapy of Rectal Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, R; Le, Y; Armour, E; Efron, J; Azad, N; Wahl, R; Gearhart, S; Herman, J [Johns Hopkins University, Baltimore, MD (United States)

    2014-06-01

    Purpose: Dose-response studies in radiation therapy are typically using single response values for tumors across ensembles of tumors. Using the high dose rate (HDR) treatment plan dose grid and pre- and post-therapy FDG-PET images, we look for correlations between voxelized dose and FDG uptake response in individual tumors. Methods: Fifteen patients were treated for localized rectal cancer using 192Ir HDR brachytherapy in conjunction with surgery. FDG-PET images were acquired before HDR therapy and 6–8 weeks after treatment (prior to surgery). Treatment planning was done on a commercial workstation and the dose grid was calculated. The two PETs and the treatment dose grid were registered to each other using non-rigid registration. The difference in PET SUV values before and after HDR was plotted versus absorbed radiation dose for each voxel. The voxels were then separated into bins for every 400 cGy of absorbed dose and the bin average values plotted similarly. Results: Individual voxel doses did not correlate with PET response; however, when group into tumor subregions corresponding to dose bins, eighty percent of the patients showed a significant positive correlation (R2 > 0) between PET uptake difference in the targeted region and the absorbed dose. Conclusion: By considering larger ensembles of voxels, such as organ average absorbed dose or the dose bins considered here, valuable information may be obtained. The dose-response correlations as measured by FDG-PET difference potentially underlines the importance of FDG-PET as a measure of response, as well as the value of voxelized information.

  3. Gosvig und das Problem der Geschichte

    DEFF Research Database (Denmark)

    Wentzer, Thomas Schwarz

    2016-01-01

    Der Essay geht der Frage nach, wieso so viele philosophische Bücher, insbesondere innerhalb der sogenannten 'kontinentalen' Philosophie des 20. Jhs, einen Titel tragen, der durch die Struktur 'x und y' gekennzeichnet ist. Hat Heideggers 'Sein und Zeit' auch hier Schule gemacht? Wenn ja, wie so? U...... These, dass die Iteration des 'und' tatsächlich und in Kontrast zur Genetivkonstruktion der Idealisten ('Phänomenologie des Geistes') die Geschichtlichkeit im Zeitalter postsubjektivistischen Denkens reflektiert....

  4. Application of the Monte Carlo integration method in calculations of dose distributions in HDR-Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Baltas, D; Geramani, K N; Ioannidis, G T; Kolotas, C; Zamboglou, N [Strahlenklinik, Stadtische Kliniken Offenbach, Offenbach (Germany); Giannouli, S [Department of Electrical and Computer Engineering, National Technical University of Athens, Athens (Greece)

    1999-12-31

    Source anisotropy is a very important factor in brachytherapy quality assurance of high dose rate HDR Ir 192 afterloading stepping sources. If anisotropy is not taken into account then doses received by a brachytherapy patient in certain directions can be in error by a clinically significant amount. Experimental measurements of anisotropy are very labour intensive. We have shown that within acceptable limits of accuracy, Monte Carlo integration (MCI) of a modified Sievert integral (3D generalisation) can provide the necessary data within a much shorter time scale than can experiments. Hence MCI can be used for routine quality assurance schedules whenever a new design of HDR or PDR Ir 192 is used for brachytherapy afterloading. Our MCI calculation results are comparable with published experimental data and Monte Carlo simulation data for microSelectron and VariSource Ir 192 sources. We have shown not only that MCI offers advantages over alternative numerical integration methods, but also that treating filtration coefficients as radial distance-dependent functions improves Sievert integral accuracy at low energies. This paper also provides anisotropy data for three new Ir 192 sources, one for microSelectron-HDR and two for the microSelectron-PDR, for which data currently is not available. The information we have obtained in this study can be incorporated into clinical practice.

  5. The high dynamic range pixel array detector (HDR-PAD): Concept and design

    Energy Technology Data Exchange (ETDEWEB)

    Shanks, Katherine S.; Philipp, Hugh T.; Weiss, Joel T.; Becker, Julian; Tate, Mark W. [Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY 14853 (United States); Gruner, Sol M., E-mail: smg26@cornell.edu [Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY 14853 (United States); Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, NY 14853 (United States)

    2016-07-27

    Experiments at storage ring light sources as well as at next-generation light sources increasingly require detectors capable of high dynamic range operation, combining low-noise detection of single photons with large pixel well depth. XFEL sources in particular provide pulse intensities sufficiently high that a purely photon-counting approach is impractical. The High Dynamic Range Pixel Array Detector (HDR-PAD) project aims to provide a dynamic range extending from single-photon sensitivity to 10{sup 6} photons/pixel in a single XFEL pulse while maintaining the ability to tolerate a sustained flux of 10{sup 11} ph/s/pixel at a storage ring source. Achieving these goals involves the development of fast pixel front-end electronics as well as, in the XFEL case, leveraging the delayed charge collection due to plasma effects in the sensor. A first prototype of essential electronic components of the HDR-PAD readout ASIC, exploring different options for the pixel front-end, has been fabricated. Here, the HDR-PAD concept and preliminary design will be described.

  6. The Ansel Adams zone system: HDR capture and range compression by chemical processing

    Science.gov (United States)

    McCann, John J.

    2010-02-01

    We tend to think of digital imaging and the tools of PhotoshopTM as a new phenomenon in imaging. We are also familiar with multiple-exposure HDR techniques intended to capture a wider range of scene information, than conventional film photography. We know about tone-scale adjustments to make better pictures. We tend to think of everyday, consumer, silver-halide photography as a fixed window of scene capture with a limited, standard range of response. This description of photography is certainly true, between 1950 and 2000, for instant films and negatives processed at the drugstore. These systems had fixed dynamic range and fixed tone-scale response to light. All pixels in the film have the same response to light, so the same light exposure from different pixels was rendered as the same film density. Ansel Adams, along with Fred Archer, formulated the Zone System, staring in 1940. It was earlier than the trillions of consumer photos in the second half of the 20th century, yet it was much more sophisticated than today's digital techniques. This talk will describe the chemical mechanisms of the zone system in the parlance of digital image processing. It will describe the Zone System's chemical techniques for image synthesis. It also discusses dodging and burning techniques to fit the HDR scene into the LDR print. Although current HDR imaging shares some of the Zone System's achievements, it usually does not achieve all of them.

  7. Vibrational experiments at the HDR [Heissdampfreaktor]: SHAG results and planning for SHAM

    International Nuclear Information System (INIS)

    Kot, C.A.; Malcher, L.; Steinhilber, H.

    1987-01-01

    As part of the second phase of vibrational/earthquake investigations at the HDR (Heissdampfreaktor) Test Facility in Kahl/Main, FRG, high-level shaker tests (SHAG) were performed during June and July 1986 using a coast-down shaker capable of generating 1000 tons of force. The purpose of these experiments was to investigate full-scale structural response, soil/structure interaction, and piping and equipment response under strong excitation conditions. While global safety considerations imposed load limitations, the HDR soil/structure system was nevertheless tested to incipient failure. The performance of pipe support systems in as many as seven different multiple support pipe hanger configurations, ranging from flexible to stiff systems, was evaluated in the tests. Data obtained in the tests are used to validate analysis methods. The vibrational/earthquake investigations at the HDR are continuing with the SHAM experiments, planned for the spring of 1988. In these experiments the VKL piping loop will be subjected to direct multiple-point excitation at extremely high levels. The objective is to investigate different pipe support configurations at extreme loading, to establish seismic margins for piping, and to investigate possible failure/plastification modes in an in situ piping system

  8. Interactive multiobjective optimization for anatomy-based three-dimensional HDR brachytherapy

    Science.gov (United States)

    Ruotsalainen, Henri; Miettinen, Kaisa; Palmgren, Jan-Erik; Lahtinen, Tapani

    2010-08-01

    In this paper, we present an anatomy-based three-dimensional dose optimization approach for HDR brachytherapy using interactive multiobjective optimization (IMOO). In brachytherapy, the goals are to irradiate a tumor without causing damage to healthy tissue. These goals are often conflicting, i.e. when one target is optimized the other will suffer, and the solution is a compromise between them. IMOO is capable of handling multiple and strongly conflicting objectives in a convenient way. With the IMOO approach, a treatment planner's knowledge is used to direct the optimization process. Thus, the weaknesses of widely used optimization techniques (e.g. defining weights, computational burden and trial-and-error planning) can be avoided, planning times can be shortened and the number of solutions to be calculated is small. Further, plan quality can be improved by finding advantageous trade-offs between the solutions. In addition, our approach offers an easy way to navigate among the obtained Pareto optimal solutions (i.e. different treatment plans). When considering a simulation model of clinical 3D HDR brachytherapy, the number of variables is significantly smaller compared to IMRT, for example. Thus, when solving the model, the CPU time is relatively short. This makes it possible to exploit IMOO to solve a 3D HDR brachytherapy optimization problem. To demonstrate the advantages of IMOO, two clinical examples of optimizing a gynecologic cervix cancer treatment plan are presented.

  9. Interactive multiobjective optimization for anatomy-based three-dimensional HDR brachytherapy

    International Nuclear Information System (INIS)

    Ruotsalainen, Henri; Miettinen, Kaisa; Palmgren, Jan-Erik; Lahtinen, Tapani

    2010-01-01

    In this paper, we present an anatomy-based three-dimensional dose optimization approach for HDR brachytherapy using interactive multiobjective optimization (IMOO). In brachytherapy, the goals are to irradiate a tumor without causing damage to healthy tissue. These goals are often conflicting, i.e. when one target is optimized the other will suffer, and the solution is a compromise between them. IMOO is capable of handling multiple and strongly conflicting objectives in a convenient way. With the IMOO approach, a treatment planner's knowledge is used to direct the optimization process. Thus, the weaknesses of widely used optimization techniques (e.g. defining weights, computational burden and trial-and-error planning) can be avoided, planning times can be shortened and the number of solutions to be calculated is small. Further, plan quality can be improved by finding advantageous trade-offs between the solutions. In addition, our approach offers an easy way to navigate among the obtained Pareto optimal solutions (i.e. different treatment plans). When considering a simulation model of clinical 3D HDR brachytherapy, the number of variables is significantly smaller compared to IMRT, for example. Thus, when solving the model, the CPU time is relatively short. This makes it possible to exploit IMOO to solve a 3D HDR brachytherapy optimization problem. To demonstrate the advantages of IMOO, two clinical examples of optimizing a gynecologic cervix cancer treatment plan are presented.

  10. Clinical implementation of a new HDR brachytherapy device for partial breast irradiation

    International Nuclear Information System (INIS)

    Scanderbeg, Daniel J.; Yashar, Catheryn; Rice, Roger; Pawlicki, Todd

    2009-01-01

    Purpose: To present the clinical implementation of a new HDR device for partial breast irradiation, the Strut-Adjusted Volume Implant (SAVI), at the University of California, San Diego. Methods and materials: The SAVI device has multiple peripheral struts that can be differentially loaded with the HDR source. Planning criteria used for evaluation of the treatment plans included the following dose volume histogram (DVH) criteria: V90 >90%, V150 <50 cc and V200 <20 cc. Results: SAVI has been used on 20 patients to date at UC San Diego. In each case, the dose was modulated according to patient-specific anatomy to cover the tumor bed, while sparing normal tissues. The dosimetric data show that we can achieve greater than 90% coverage with respect to V90 (median of 95.3%) and also keep a low V150 and V200 dose at 24.5 and 11.2 cc, respectively. Complete treatment can be done within a 30-min time slot, which includes implant verification, setup, and irradiation time as well as wound dressing. Conclusion: SAVI has been implemented at UC San Diego for accelerated partial breast irradiation with excellent tumor bed conformance and minimal normal tissue exposure. Patient positioning is the key to identifying any inter-fraction device motion. Device asymmetry or tissue conformance has been shown to resolve itself 24 h after the device implantation. The device can be implemented into an existing HDR program with minimal effort

  11. Near constant-time optimal piecewise LDR to HDR inverse tone mapping

    Science.gov (United States)

    Chen, Qian; Su, Guan-Ming; Yin, Peng

    2015-02-01

    In a backward compatible HDR image/video compression, it is a general approach to reconstruct HDR from compressed LDR as a prediction to original HDR, which is referred to as inverse tone mapping. Experimental results show that 2- piecewise 2nd order polynomial has the best mapping accuracy than 1 piece high order or 2-piecewise linear, but it is also the most time-consuming method because to find the optimal pivot point to split LDR range to 2 pieces requires exhaustive search. In this paper, we propose a fast algorithm that completes optimal 2-piecewise 2nd order polynomial inverse tone mapping in near constant time without quality degradation. We observe that in least square solution, each entry in the intermediate matrix can be written as the sum of some basic terms, which can be pre-calculated into look-up tables. Since solving the matrix becomes looking up values in tables, computation time barely differs regardless of the number of points searched. Hence, we can carry out the most thorough pivot point search to find the optimal pivot that minimizes MSE in near constant time. Experiment shows that our proposed method achieves the same PSNR performance while saving 60 times computation time compared to the traditional exhaustive search in 2-piecewise 2nd order polynomial inverse tone mapping with continuous constraint.

  12. NOTE: Monte Carlo evaluation of kerma in an HDR brachytherapy bunker

    Science.gov (United States)

    Pérez-Calatayud, J.; Granero, D.; Ballester, F.; Casal, E.; Crispin, V.; Puchades, V.; León, A.; Verdú, G.

    2004-12-01

    In recent years, the use of high dose rate (HDR) after-loader machines has greatly increased due to the shift from traditional Cs-137/Ir-192 low dose rate (LDR) to HDR brachytherapy. The method used to calculate the required concrete and, where appropriate, lead shielding in the door is based on analytical methods provided by documents published by the ICRP, the IAEA and the NCRP. The purpose of this study is to perform a more realistic kerma evaluation at the entrance maze door of an HDR bunker using the Monte Carlo code GEANT4. The Monte Carlo results were validated experimentally. The spectrum at the maze entrance door, obtained with Monte Carlo, has an average energy of about 110 keV, maintaining a similar value along the length of the maze. The comparison of results from the aforementioned values with the Monte Carlo ones shows that results obtained using the albedo coefficient from the ICRP document more closely match those given by the Monte Carlo method, although the maximum value given by MC calculations is 30% greater.

  13. Characterization of HDR Ir-192 source for 3D planning system

    International Nuclear Information System (INIS)

    Fonseca, Gabriel P.; Yoriyaz, Helio; Antunes, Paula C.G.; Siqueira, Paulo T.D.; Rubo, Rodrigo; Ferreira, Louise A.

    2011-01-01

    Brachytherapy treatment involves surgical or cavitary insertion of radioactive sources for diseases treatments, such as: lung, gynecologic or prostate cancer. This technique has great ability to administer high doses to the tumor, with adjacent normal tissue preservation equal or better than external beam radiation therapy. Several innovations have been incorporated in this treatment technique, such as, 3D treatment planning system and computer guided sources. In detriment to scientific advances there are no protocols that relate dose with tumor volume, organs or A point, established by ICRU38 and used to prescribe dose in treatment planning system. Several international studies, like as EMBRACE, the multicentre international study, has been trying to correlate the dose volume using 3D planning systems and medical images, as those obtained by CT or MRI, to establish treatment protocols. With the objective of analyzing the 3D dose distribution, a micro Selectron-HDR remote afterloading device for high dose-rate (HDR) was characterized in the present work. Through the data provided by the manufacturer the source was simulated, using the MCNP5 code to calculate American Association of Physicists in Medicine Task Group No. 43 report (AAPM TG43) specified parameters. The simulations have shown great agreement when compared to the ONCENTRA planning system results and those provided by literature. The micro Selectron-HDR remote afterloading device will be utilized to simulate 3D dose distribution through CT images processed by an auxiliary software which process DICOM images. (author)

  14. Comparative Analysis between LDR and HDR Images for Automatic Fruit Recognition and Counting

    Directory of Open Access Journals (Sweden)

    Tatiana M. Pinho

    2017-01-01

    Full Text Available Precision agriculture is gaining an increasing interest in the current farming paradigm. This new production concept relies on the use of information technology (IT to provide a control and supervising structure that can lead to better management policies. In this framework, imaging techniques that provide visual information over the farming area play an important role in production status monitoring. As such, accurate representation of the gathered production images is a major concern, especially if those images are used in detection and classification tasks. Real scenes, observed in natural environment, present high dynamic ranges that cannot be represented by the common LDR (Low Dynamic Range devices. However, this issue can be handled by High Dynamic Range (HDR images since they have the ability to store luminance information similarly to the human visual system. In order to prove their advantage in image processing, a comparative analysis between LDR and HDR images, for fruits detection and counting, was carried out. The obtained results show that the use of HDR images improves the detection performance to more than 30% when compared to LDR.

  15. Characterization of HDR Ir-192 source for 3D planning system

    Energy Technology Data Exchange (ETDEWEB)

    Fonseca, Gabriel P.; Yoriyaz, Helio; Antunes, Paula C.G.; Siqueira, Paulo T.D., E-mail: gabriel.fonseca@usp.b, E-mail: hyoriyaz@ipen.b, E-mail: ptsiquei@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Rubo, Rodrigo [Universidade de Sao Paulo (HC/FMUSP), Sao Paulo, SP (Brazil). Hospital das Clinicas. Servico de Radioterapia; Minamisawa, Renato A., E-mail: renato.minamisawa@psi.c [Paul Scherrer Institut (PSI), Villigen (Switzerland); Ferreira, Louise A. [Universidade Estadual de Maringa (UEM), PR (Brazil). Fac. de Medicina

    2011-07-01

    Brachytherapy treatment involves surgical or cavitary insertion of radioactive sources for diseases treatments, such as: lung, gynecologic or prostate cancer. This technique has great ability to administer high doses to the tumor, with adjacent normal tissue preservation equal or better than external beam radiation therapy. Several innovations have been incorporated in this treatment technique, such as, 3D treatment planning system and computer guided sources. In detriment to scientific advances there are no protocols that relate dose with tumor volume, organs or A point, established by ICRU38 and used to prescribe dose in treatment planning system. Several international studies, like as EMBRACE, the multicentre international study, has been trying to correlate the dose volume using 3D planning systems and medical images, as those obtained by CT or MRI, to establish treatment protocols. With the objective of analyzing the 3D dose distribution, a micro Selectron-HDR remote afterloading device for high dose-rate (HDR) was characterized in the present work. Through the data provided by the manufacturer the source was simulated, using the MCNP5 code to calculate American Association of Physicists in Medicine Task Group No. 43 report (AAPM TG43) specified parameters. The simulations have shown great agreement when compared to the ONCENTRA planning system results and those provided by literature. The micro Selectron-HDR remote afterloading device will be utilized to simulate 3D dose distribution through CT images processed by an auxiliary software which process DICOM images. (author)

  16. The effect of split pixel HDR image sensor technology on MTF measurements

    Science.gov (United States)

    Deegan, Brian M.

    2014-03-01

    Split-pixel HDR sensor technology is particularly advantageous in automotive applications, because the images are captured simultaneously rather than sequentially, thereby reducing motion blur. However, split pixel technology introduces artifacts in MTF measurement. To achieve a HDR image, raw images are captured from both large and small sub-pixels, and combined to make the HDR output. In some cases, a large sub-pixel is used for long exposure captures, and a small sub-pixel for short exposures, to extend the dynamic range. The relative size of the photosensitive area of the pixel (fill factor) plays a very significant role in the output MTF measurement. Given an identical scene, the MTF will be significantly different, depending on whether you use the large or small sub-pixels i.e. a smaller fill factor (e.g. in the short exposure sub-pixel) will result in higher MTF scores, but significantly greater aliasing. Simulations of split-pixel sensors revealed that, when raw images from both sub-pixels are combined, there is a significant difference in rising edge (i.e. black-to-white transition) and falling edge (white-to-black) reproduction. Experimental results showed a difference of ~50% in measured MTF50 between the falling and rising edges of a slanted edge test chart.

  17. Independent verification of the delivered dose in High-Dose Rate (HDR) brachytherapy

    International Nuclear Information System (INIS)

    Portillo, P.; Feld, D.; Kessler, J.

    2009-01-01

    An important aspect of a Quality Assurance program in Clinical Dosimetry is an independent verification of the dosimetric calculation done by the Treatment Planning System for each radiation treatment. The present paper is aimed at creating a spreadsheet for the verification of the dose recorded at a point of an implant with radioactive sources and HDR in gynecological injuries. An 192 Ir source automatic differed loading equipment, GammaMedplus model, Varian Medical System with HDR installed at the Angel H. Roffo Oncology Institute has been used. The planning system implemented for getting the dose distribution is the BraquiVision. The sources coordinates as well as those of the calculation point (Rectum) are entered into the Excel-devised verification program by assuming the existence of a point source in each one of the applicators' positions. Such calculation point has been selected as the rectum is an organ at risk, therefore determining the treatment planning. The dose verification is performed at points standing at a sources distance having at least twice the active length of such sources, so they may be regarded as point sources. Most of the sources used in HDR brachytherapy with 192 Ir have a 5 mm active length for all equipment brands. Consequently, the dose verification distance must be at least of 10 mm. (author)

  18. An experimental MOSFET approach to characterize (192)Ir HDR source anisotropy.

    Science.gov (United States)

    Toye, W C; Das, K R; Todd, S P; Kenny, M B; Franich, R D; Johnston, P N

    2007-09-07

    The dose anisotropy around a (192)Ir HDR source in a water phantom has been measured using MOSFETs as relative dosimeters. In addition, modeling using the EGSnrc code has been performed to provide a complete dose distribution consistent with the MOSFET measurements. Doses around the Nucletron 'classic' (192)Ir HDR source were measured for a range of radial distances from 5 to 30 mm within a 40 x 30 x 30 cm(3) water phantom, using a TN-RD-50 MOSFET dosimetry system with an active area of 0.2 mm by 0.2 mm. For each successive measurement a linear stepper capable of movement in intervals of 0.0125 mm re-positioned the MOSFET at the required radial distance, while a rotational stepper enabled angular displacement of the source at intervals of 0.9 degrees . The source-dosimeter arrangement within the water phantom was modeled using the standardized cylindrical geometry of the DOSRZnrc user code. In general, the measured relative anisotropy at each radial distance from 5 mm to 30 mm is in good agreement with the EGSnrc simulations, benchmark Monte Carlo simulation and TLD measurements where they exist. The experimental approach employing a MOSFET detection system of small size, high spatial resolution and fast read out capability allowed a practical approach to the determination of dose anisotropy around a HDR source.

  19. Impact of using linear optimization models in dose planning for HDR brachytherapy

    International Nuclear Information System (INIS)

    Holm, Aasa; Larsson, Torbjoern; Carlsson Tedgren, Aasa

    2012-01-01

    Purpose: Dose plans generated with optimization models hitherto used in high-dose-rate (HDR) brachytherapy have shown a tendency to yield longer dwell times than manually optimized plans. Concern has been raised for the corresponding undesired hot spots, and various methods to mitigate these have been developed. The hypotheses upon this work is based are (a) that one cause for the long dwell times is the use of objective functions comprising simple linear penalties and (b) that alternative penalties, as these are piecewise linear, would lead to reduced length of individual dwell times. Methods: The characteristics of the linear penalties and the piecewise linear penalties are analyzed mathematically. Experimental comparisons between the two types of penalties are carried out retrospectively for a set of prostate cancer patients. Results: When the two types of penalties are compared, significant changes can be seen in the dwell times, while most dose-volume parameters do not differ significantly. On average, total dwell times were reduced by 4.2%, with a reduction of maximum dwell times by 25%, when the alternative penalties were used. Conclusions: The use of linear penalties in optimization models for HDR brachytherapy is one cause for the undesired long dwell times that arise in mathematically optimized plans. By introducing alternative penalties, a significant reduction in dwell times can be achieved for HDR brachytherapy dose plans. Although various measures for mitigating the long dwell times are already available, the observation that linear penalties contribute to their appearance is of fundamental interest.

  20. Prostate CT segmentation method based on nonrigid registration in ultrasound-guided CT-based HDR prostate brachytherapy

    Science.gov (United States)

    Yang, Xiaofeng; Rossi, Peter; Ogunleye, Tomi; Marcus, David M.; Jani, Ashesh B.; Mao, Hui; Curran, Walter J.; Liu, Tian

    2014-01-01

    Purpose: The technological advances in real-time ultrasound image guidance for high-dose-rate (HDR) prostate brachytherapy have placed this treatment modality at the forefront of innovation in cancer radiotherapy. Prostate HDR treatment often involves placing the HDR catheters (needles) into the prostate gland under the transrectal ultrasound (TRUS) guidance, then generating a radiation treatment plan based on CT prostate images, and subsequently delivering high dose of radiation through these catheters. The main challenge for this HDR procedure is to accurately segment the prostate volume in the CT images for the radiation treatment planning. In this study, the authors propose a novel approach that integrates the prostate volume from 3D TRUS images into the treatment planning CT images to provide an accurate prostate delineation for prostate HDR treatment. Methods: The authors’ approach requires acquisition of 3D TRUS prostate images in the operating room right after the HDR catheters are inserted, which takes 1–3 min. These TRUS images are used to create prostate contours. The HDR catheters are reconstructed from the intraoperative TRUS and postoperative CT images, and subsequently used as landmarks for the TRUS–CT image fusion. After TRUS–CT fusion, the TRUS-based prostate volume is deformed to the CT images for treatment planning. This method was first validated with a prostate-phantom study. In addition, a pilot study of ten patients undergoing HDR prostate brachytherapy was conducted to test its clinical feasibility. The accuracy of their approach was assessed through the locations of three implanted fiducial (gold) markers, as well as T2-weighted MR prostate images of patients. Results: For the phantom study, the target registration error (TRE) of gold-markers was 0.41 ± 0.11 mm. For the ten patients, the TRE of gold markers was 1.18 ± 0.26 mm; the prostate volume difference between the authors’ approach and the MRI-based volume was 7.28% ± 0

  1. Prostate CT segmentation method based on nonrigid registration in ultrasound-guided CT-based HDR prostate brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xiaofeng, E-mail: xyang43@emory.edu; Rossi, Peter; Ogunleye, Tomi; Marcus, David M.; Jani, Ashesh B.; Curran, Walter J.; Liu, Tian [Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, Georgia 30322 (United States); Mao, Hui [Department of Radiology and Imaging Sciences, Emory University, Atlanta, Georgia 30322 (United States)

    2014-11-01

    Purpose: The technological advances in real-time ultrasound image guidance for high-dose-rate (HDR) prostate brachytherapy have placed this treatment modality at the forefront of innovation in cancer radiotherapy. Prostate HDR treatment often involves placing the HDR catheters (needles) into the prostate gland under the transrectal ultrasound (TRUS) guidance, then generating a radiation treatment plan based on CT prostate images, and subsequently delivering high dose of radiation through these catheters. The main challenge for this HDR procedure is to accurately segment the prostate volume in the CT images for the radiation treatment planning. In this study, the authors propose a novel approach that integrates the prostate volume from 3D TRUS images into the treatment planning CT images to provide an accurate prostate delineation for prostate HDR treatment. Methods: The authors’ approach requires acquisition of 3D TRUS prostate images in the operating room right after the HDR catheters are inserted, which takes 1–3 min. These TRUS images are used to create prostate contours. The HDR catheters are reconstructed from the intraoperative TRUS and postoperative CT images, and subsequently used as landmarks for the TRUS–CT image fusion. After TRUS–CT fusion, the TRUS-based prostate volume is deformed to the CT images for treatment planning. This method was first validated with a prostate-phantom study. In addition, a pilot study of ten patients undergoing HDR prostate brachytherapy was conducted to test its clinical feasibility. The accuracy of their approach was assessed through the locations of three implanted fiducial (gold) markers, as well as T2-weighted MR prostate images of patients. Results: For the phantom study, the target registration error (TRE) of gold-markers was 0.41 ± 0.11 mm. For the ten patients, the TRE of gold markers was 1.18 ± 0.26 mm; the prostate volume difference between the authors’ approach and the MRI-based volume was 7.28% ± 0

  2. Mensch und Maschine in Übersetzungsprozessen

    DEFF Research Database (Denmark)

    Hansen, Gyde

    2014-01-01

    gebrauchstauglich sein. In meinem empirischen Projekt zur Erforschung notwendiger Kompetenzen, zum Übersetzen, Revidieren und zum Pre- und Post-Editing, TraREdit, arbeite ich mit den Sprachen Deutsch, Dänisch und Englisch. Trotz offensichtlicher Mängel von Maschinenübersetzungen muss man erkennen, dass diese besser...

  3. Sprachvermittlung und Spracherwerb in Afrika. Deutsch nach ...

    African Journals Online (AJOL)

    erlernende Fremdsprache richtig und auf hohem Niveau sprechen zu lernen. Lehrende sollten alles daransetzen zu verhindern, dass die Lernenden in dieser Vereinfachungsphase stehen bleiben und ihre Sprache fossilieren. Die Bewusstmachung der Ähnlichkeiten von Zulu und. Deutsch kann dazu beitragen, indem man ...

  4. Zustand und Perspektiven der Kapitalmarktfinanzierung in Deutschland

    DEFF Research Database (Denmark)

    Beck, Thorsten; Kaserer, Christoph; Rapp, Marc Steffen

    2016-01-01

    Die Autoren haben sich im Rahmen des durch das Bundesministerium für Wirtschaft und Energie (BMWi) in Auftrag gegebenen Forschungsprojekts „Beteiligungs- und Kapitalmarktfinanzierung im deutschen Finanzsystem: Zustand und Entwicklungsperspektiven“ (Dienstleistungsprojekt I C 4 -27/14) mit dem Zus...

  5. Data Science und Analytics in Bibliotheken

    Directory of Open Access Journals (Sweden)

    José Luis Preza

    2017-09-01

    Full Text Available Bibliotheken sind in einer priviligierten Situation: Sie verwalten riesige Mengen von Daten und Informationen. Data Science und Analytics-Methoden ermöglichen es Bibliotheken, den Inhalt, den sie verwalten, voll auszunutzen, um den Nutzern bessere Informationen, Suche und Empfehlungen zu bieten.

  6. Genitourinary Toxicity After High-Dose-Rate (HDR) Brachytherapy Combined With Hypofractionated External Beam Radiotherapy for Localized Prostate Cancer: An Analysis to Determine the Correlation Between Dose-Volume Histogram Parameters in HDR Brachytherapy and Severity of Toxicity

    International Nuclear Information System (INIS)

    Ishiyama, Hiromichi; Kitano, Masashi; Satoh, Takefumi; Kotani, Shouko; Uemae, Mineko; Matsumoto, Kazumasa; Okusa, Hiroshi; Tabata, Ken-ichi; Baba, Shiro; Hayakawa, Kazushige

    2009-01-01

    Purpose: To evaluate the severity of genitourinary (GU) toxicity in high-dose-rate (HDR) brachytherapy combined with hypofractionated external beam radiotherapy (EBRT) for prostate cancer and to explore factors that might affect the severity of GU toxicity. Methods and Materials: A total of 100 Japanese men with prostate cancer underwent 192 Ir HDR brachytherapy combined with hypofractionated EBRT. Mean (SD) dose to 90% of the planning target volume was 6.3 (0.7) Gy per fraction of HDR. After 5 fractions of HDR treatment, EBRT with 10 fractions of 3 Gy was administrated. The urethral volume receiving 1-15 Gy per fraction in HDR brachytherapy (V1-V15) and the dose to at least 5-100% of urethral volume in HDR brachytherapy (D5-D100) were compared between patients with Grade 3 toxicity and those with Grade 0-2 toxicity. Prostate volume, patient age, and International Prostate Symptom Score were also compared between the two groups. Results: Of the 100 patients, 6 displayed Grade 3 acute GU toxicity, and 12 displayed Grade 3 late GU toxicity. Regarding acute GU toxicity, values of V1, V2, V3, and V4 were significantly higher in patients with Grade 3 toxicity than in those with Grade 0-2 toxicity. Regarding late GU toxicity, values of D70, D80, V12, and V13 were significantly higher in patients with Grade 3 toxicity than in those with Grade 0-2 toxicity. Conclusions: The severity of GU toxicity in HDR brachytherapy combined with hypofractionated EBRT for prostate cancer was relatively high. The volume of prostatic urethra was associated with grade of acute GU toxicity, and urethral dose was associated with grade of late GU toxicity.

  7. Marktkonstitution und Regulierung der unabhängigen Film- und Fernsehproduktion : Staat, Verbände und Gewerkschaften im deutsch-britischen Vergleich

    OpenAIRE

    Elbing, Sabine; Voelzkow, Helmut

    2006-01-01

    "In einem internationalen Vergleich von Deutschland und Großbritannien wird untersucht, welche Beiträge die staatliche Politik und die Wirtschafts- und Sozialpartner (Wirtschafts- und Arbeitgeberverbände sowie Gewerkschaften) zur Förderung der unabhängigen Film- und Fernsehproduktion leisten. Es wird gezeigt, dass die britische Medienpolitik die Position der unabhängigen Film- und Fernsehproduktion gegenüber den Fernsehsendern gestärkt hat. In Deutschland hat die Medienpolitik darauf verzicht...

  8. SU-F-T-55: Reproducibility of Interstitial HDR Brachytherapy Plans

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S; Ellis, R; Traughber, B; Podder, T [University Hospitals Case Medical Center, Cleveland, OH (United States)

    2016-06-15

    Purpose: Treating gynecological cancers with interstitial high-dose-rate (HDR) brachytherapy requires precise reconstruction of catheter positions to obtain accurate dosimetric plans. In this study, we investigated the degree of reproducibility of dosimetric plans for Syed HDR brachytherapy. Methods: We randomly selected five patients having cervix-vaginal cancer who were recently treated in our clinic with interstitial HDR brachytherapy with a prescription dose of 25–30 Gy in five fractions. Interstitial needles/catheters were placed under fluoroscopic guidance and intra-operative 3T MRI scan was performed to confirm the desired catheter placement for adequate target volume coverage. A CT scan was performed and fused with the MRI for delineating high-risk CTV (HR-CTV), intermediate-risk CTV (IR-CTV) and OARs. HDR treatment plans were generated using Oncentra planning software. A single plan was used for all five fractions of treatment for each patient. For this study, we took the original clinical plan and removed all the reconstructed catheters from the plan keeping the original contours unchanged. Then, we manually reconstructed all the catheters and entered the same dwell time from the first original clinical plan. The dosimetric parameters studied were: D90 for HR-CTV and IR-CV, and D2cc for bladder, rectum, sigmoid and bowel. Results: The mean of absolute differences in dosimetric coverage (D90) were (range): 1.3% (1.0–2.0%) and 2.0% (0.9–3.6%) for HR-CTV and IR-CTV, respectively. In case of OARs, the mean of absolute variations in D2cc were (range): 4.7% (0.7–8.9%) for bladder, 1.60% (0.3–3.2%) for rectum, 1.6% (0–3.9%) for sigmoid, and 1.8% (0–5.1%) for bowel. Conclusion: Overall, the reproducibility of interstitial HDR plans was within clinically acceptable limit. Observed maximum variation in D2cc for bladder. If number of catchers and dwell points were relatively low or any one catheter was heavily loaded, then reproducibility of the plan

  9. Anatomy-based inverse planning dose optimization in HDR prostate implant: A toxicity study

    International Nuclear Information System (INIS)

    Mahmoudieh, Alireza; Tremblay, Christine; Beaulieu, Luc; Lachance, Bernard; Harel, Francois; Lessard, Etienne; Pouliot, Jean; Vigneault, Eric

    2005-01-01

    Background and purpose: The aim of this study is to evaluate the acute and late complications in patients who have received HDR implant boost using inverse planning, and to determine dose volume correlations. Patients and methods: Between September 1999 and October 2002, 44 patients with locally advanced prostate cancer (PSA ≥10 ng/ml, and/or Gleason score ≥7, and/or Stage T2c or higher) were treated with 40-45 Gy external pelvic field followed by 2-3 fraction of inverse-planned HDR implant boost (6-9.5 Gy /fraction). Median follow-up time was 1.7 years with 81.8% of patients who had at least 12 months of follow up (range 8.6-42.5. Acute and late morbidity data were collected and graded according to RTOG criteria. Questionnaires were used to collect prostate related measures of quality of life, and international prostate symptom score (IPSS) before and after treatment. Dose-volume histograms for prostate, urethra, bladder, penis bulb and rectum were analyzed. Results: The median patient age was 64 years. Of these, 32% were in the high risk group, and 61% in the intermediate risk group. 3 patients (7%) had no adverse prognostic factors. A single grade 3 GU acute toxicity was reported but no grade 3-4 acute GI toxicity. No grade 3-4 late GU or GI toxicity was reported. Acute (late) grade 2 urinary and rectal symptoms were reported in 31.8 (11.4%) and 4.6% (4.6%) of patients, respectively. A trend for predicting acute GU toxicity is seen for total HDR dose of more than 18 Gy (OR=3.6, 95%CI=[0.96-13.5], P=0.058). The evolution of toxicity is presented for acute and late GU/GI toxicity. Erectile dysfunction occurs in approximately 27% of patients who were not on hormonal deprivation, but may be taking sildenafil. The IPSS peaked on averaged 6 weeks post-implant and returned to the baseline at a median of 6 months. Conclusions: Inverse-planned HDR brachytherapy is a viable option to deliver higher dose to the prostate as a boost without increasing GU or rectal

  10. Developing A Directional High-Dose Rate (d-HDR) Brachytherapy Source

    Science.gov (United States)

    Heredia, Athena Yvonne

    Conventional sources used in brachytherapy provide nearly isotropic or radially symmetric dose distributions. Optimizations of dose distributions have been limited to varied dwell times at specified locations within a given treatment volume, or manipulations in source position for seed implantation techniques. In years past, intensity modulated brachytherapy (IMBT) has been used to reduce the amount of radiation to surrounding sensitive structures in select intracavitary cases by adding space or partial shields. Previous work done by Lin et al., at the University of Wisconsin-Madison, has shown potential improvements in conformality for brachytherapy treatments using a directionally shielded low dose rate (LDR) source for treatments in breast and prostate. Directional brachytherapy sources irradiate approximately half of the radial angles around the source, and adequately shield a quarter of the radial angles on the opposite side, with sharp gradient zones between the treated half and shielded quarter. With internally shielded sources, the radiation can be preferentially emitted in such a way as to reduce toxicities in surrounding critical organs. The objective of this work is to present findings obtained in the development of a new directional high dose rate (d-HDR) source. To this goal, 103Pd (Z = 46) is reintroduced as a potential radionuclide for use in HDR brachytherapy. 103Pd has a low average photon energy (21 keV) and relatively short half -life (17 days), which is why it has historically been used in low dose rate applications and implantation techniques. Pd-103 has a carrier-free specific activity of 75000 Ci/g. Using cyclotron produced 103Pd, near carrier-free specific activities can be achieved, providing suitability for high dose rate applications. The evolution of the d-HDR source using Monte Carlo simulations is presented, along with dosimetric parameters used to fully characterize the source. In addition, a discussion on how to obtain elemental

  11. High dynamic range adaptive real-time smart camera: an overview of the HDR-ARTiST project

    Science.gov (United States)

    Lapray, Pierre-Jean; Heyrman, Barthélémy; Ginhac, Dominique

    2015-04-01

    Standard cameras capture only a fraction of the information that is visible to the human visual system. This is specifically true for natural scenes including areas of low and high illumination due to transitions between sunlit and shaded areas. When capturing such a scene, many cameras are unable to store the full Dynamic Range (DR) resulting in low quality video where details are concealed in shadows or washed out by sunlight. The imaging technique that can overcome this problem is called HDR (High Dynamic Range) imaging. This paper describes a complete smart camera built around a standard off-the-shelf LDR (Low Dynamic Range) sensor and a Virtex-6 FPGA board. This smart camera called HDR-ARtiSt (High Dynamic Range Adaptive Real-time Smart camera) is able to produce a real-time HDR live video color stream by recording and combining multiple acquisitions of the same scene while varying the exposure time. This technique appears as one of the most appropriate and cheapest solution to enhance the dynamic range of real-life environments. HDR-ARtiSt embeds real-time multiple captures, HDR processing, data display and transfer of a HDR color video for a full sensor resolution (1280 1024 pixels) at 60 frames per second. The main contributions of this work are: (1) Multiple Exposure Control (MEC) dedicated to the smart image capture with alternating three exposure times that are dynamically evaluated from frame to frame, (2) Multi-streaming Memory Management Unit (MMMU) dedicated to the memory read/write operations of the three parallel video streams, corresponding to the different exposure times, (3) HRD creating by combining the video streams using a specific hardware version of the Devebecs technique, and (4) Global Tone Mapping (GTM) of the HDR scene for display on a standard LCD monitor.

  12. [Die baltischen Lande im Zeitalter der Reformation und Konfessionalisierung : Livland, Estland, Ösel, Ingermanland, Kurland und Lettgallen : Stadt, Land und Konfession 1500-1721. Teil 4. Hrsg. von Matthias Asche, Werner Buchholtz und Anton Schindlin

    Index Scriptorium Estoniae

    Maasing, Madis, 1984-

    2013-01-01

    Arvustus: Die baltischen Lande im Zeitalter der Reformation und Konfessionalisierung : Livland, Estland, Ösel, Ingermanland, Kurland und Lettgallen : Stadt, Land und Konfession 1500-1721. Teil 4. (Katholisches Leben und Kirchenreform im Zeitalter der Glaubensspaltung, 72). Hrsg. von Matthias Asche, Werner Buchholtz und Anton Schindling. Verlag Aschendorff. Münster 2012

  13. GIS und Fernerkundung für Landschaftsmonitoring und Landschaftsplanung

    Science.gov (United States)

    Blaschke, Thomas

    2002-09-01

    Der Beitrag beleuchtet die Rolle der Geographischen Informationsverarbeitung hinsichtlich der Aufgaben in der Umweltüberwachung. Dabei wird über etablierte "sektorale" Umweltbeobachtungssysteme (Boden, Wasser, Luft) hinaus zunehmend der Bedarf an einer integrativen Betrachtung der Landschaft deutlich, insbesondere in mittleren bis kleinen Maßstäben. Wie verändern sich ganze Landschaften in Deutschland, in Europa? Welches sind Bereiche kritischer Abnahme landschaftlicher Diversität? Wie können landschaftliche Vielfalt und Eigenart erhalten beziehungsweise deren Erhalt überwacht werden? Diese und weitere Fragen drängen sich vor allem bei der Erstellung langfristiger Szenarien der Veränderung ganzer Landschaften und in der Nachhaltigkeitsdiskussion auf.

  14. Ethik, Recht und Theologie. Reproduktionstechnologien in Polen

    Directory of Open Access Journals (Sweden)

    Susanne Lettow

    2006-03-01

    Full Text Available Die bisherigen Debatten um Stammzellforschung, Klonen und Reproduktionstechnologien wurden in Deutschland weitgehend im nationalstaatlichen Rahmen und mit Blick auf Entwicklungen im angelsächsischen Raum geführt. Dabei sind diese Forschungsrichtungen und Technologien kein genuin „westliches“ Phänomen – immerhin wurde das erste Retortenkind in Polen bereits 1987 geboren. Heidi Hofmann lässt in ihrem Band polnische Philosoph/-innen, Jurist/-innen und Politikerinnen zu Wort kommen und öffnet den Blick dafür, dass die Art und Weise, in der Reproduktionstechnologien gesellschaftlich problematisiert werden, in Polen durch ganz andere politische, kulturelle und historische Konstellationen geprägt ist als in Deutschland.

  15. Restaurierung von Seen und Renaturierung von Seeufern

    Science.gov (United States)

    Grüneberg, Björn; Ostendorp, Wolfgang; Leßmann, Dieter; Wauer, Gerlinde; Nixdorf, Brigitte

    Süßwasserseen haben als ökosysteme und Lebensraum für Pflanzen und Tiere eine herausragende Bedeutung für die Artenvielfalt auf der Erde und prägen als Landschaftselemente unsere natürliche Umwelt. Seen fungieren als natürliche Stoffsenken, vor allem für Kohlenstoff und Nährstoffe, aber auch als Senken für in ihren Einzugsgebieten emittierte gelöste und feste Schadstoffe. Darüber hinaus ist Wasser eine wichtige Naturressource. Süßwasserseen stellen in den meisten Regionen der Erde lebenswichtige Quellen für die Versorgung mit Trinkwasser und tierischem Eiweiß (Fischfang) dar. Sie dienen als Wasserspeicher für die landwirtschaftliche und industrielle Nutzung. Auch für Erholungsaktivitäten des Menschen kommt ihnen eine große Bedeutung zu.

  16. E-Government und E-Banking: Aktueller Stand, Evaluation und Erfolgsfaktoren

    OpenAIRE

    Bayer, Tobias

    2002-01-01

    Zu Max Webers Zeiten entsprach die Bürokratie noch ganz dem Vorbild des preussischen Militärs " klare Hierarchien und klare Aufgabenbereiche schlugen sich nieder in Effizienz und Effektivität. Heute ist das Bild getrübt und Worte wie "Erstarrung", "Überreglementierung" und "Verwaltungskultur" machen die Runde. Neben den gestiegenen Erwartungen der Bürger, die sich in Zeiten des E-Banking und E-Commerce nicht mehr in lange Warteschlangen einreihen wollen und auf die rigiden Öffnungszeiten der ...

  17. A comparison of HDR brachytherapy and IMRT techniques for dose escalation in prostate cancer: A radiobiological modeling study

    Energy Technology Data Exchange (ETDEWEB)

    Fatyga, M.; Williamson, J. F.; Dogan, N.; Todor, D.; Siebers, J. V.; George, R.; Barani, I.; Hagan, M. [Department of Radiation Oncology, Virginia Commonwealth University Medical Center, 401 College Street, Richmond, Virginia 23298 (United States)

    2009-09-15

    A course of one to three large fractions of high dose rate (HDR) interstitial brachytherapy is an attractive alternative to intensity modulated radiation therapy (IMRT) for delivering boost doses to the prostate in combination with additional external beam irradiation for intermediate risk disease. The purpose of this work is to quantitatively compare single-fraction HDR boosts to biologically equivalent fractionated IMRT boosts, assuming idealized image guided delivery (igIMRT) and conventional delivery (cIMRT). For nine prostate patients, both seven-field IMRT and HDR boosts were planned. The linear-quadratic model was used to compute biologically equivalent dose prescriptions. The cIMRT plan was evaluated as a static plan and with simulated random and setup errors. The authors conclude that HDR delivery produces a therapeutic ratio which is significantly better than the conventional IMRT and comparable to or better than the igIMRT delivery. For the HDR, the rectal gBEUD analysis is strongly influenced by high dose DVH tails. A saturation BED, beyond which no further injury can occur, must be assumed. Modeling of organ motion uncertainties yields mean outcomes similar to static plan outcomes.

  18. A novel GATA3 nonsense mutation in a newly diagnosed adult patient of hypoparathyroidism, deafness, and renal dysplasia (HDR) syndrome.

    Science.gov (United States)

    Nanba, Kazutaka; Usui, Takeshi; Nakamura, Michikazu; Toyota, Yuko; Hirota, Keisho; Tamanaha, Tamiko; Kawashima, Sachiko-Tsukamoto; Nakao, Kanako; Yuno, Akiko; Tagami, Tetsuya; Naruse, Mitsuhide; Shimatsu, Akira

    2013-01-01

    Hypoparathyroidism, deafness, and renal dysplasia (HDR) syndrome is an autosomal dominant disorder caused by a GATA3 gene mutation. Here we report a novel mutation of GATA3 in a patient diagnosed with HDR syndrome at the age of 58 with extensive intracranial calcification. A 58-year-old Japanese man showed severe hypocalcemia and marked calcification in the basal ganglia, cerebellum, deep white matter, and gray-white junction on computed tomography (CT). The serum intact parathyroid hormone level was relatively low against low serum calcium concentration. The patient had been diagnosed with bilateral sensorineural deafness in childhood and had a family history of hearing disorders. Imaging studies revealed no renal anomalies. The patient was diagnosed with HDR syndrome, and genetic testing was performed. Genetic analysis of GATA3 showed a novel nonsense mutation at codon 198 (S198X) in exon 3. The S198X mutation leads to a loss of two zinc finger deoxyribonucleic acid (DNA) binding domains and is considered to be responsible for HDR syndrome. We identified a novel nonsense mutation of GATA3 in an adult patient with HDR syndrome who showed extensive intracranial calcification.

  19. Personen- und Güterverkehr

    Science.gov (United States)

    Flämig, Heike; Gertz, Carsten; Mühlhausen, Thorsten

    Im Jahr 2010 war in Deutschland der Verkehrssektor für fast 20 % der energiebedingten Treibhausgase verantwortlich. Das Klima hat sich bereits so weit verändert, dass zur Sicherung der Funktion der Verkehrssysteme auch Anpassungsmaßnahmen notwendig sind. Diese Maßnahmen müssen durch verkehrsreduzierende bzw. -beeinflussende Maßnahmen ergänzt werden. Ausgehend von den Emissionen im Verkehrssektor und möglichen Minderungen schlägt das Kapitel den Bogen zu Optionen der Anpassung an den Klimawandel, die ausführlich und konkret dargestellt werden. Besonders betrachtet werden die mannigfaltigen Gefahren der Rückkopplung sowie die vielfältigen Wechselwirungen mit anderen Themengebieten und Sektoren.

  20. Osteoporose und Genetik des Knochenstoffwechsels

    Directory of Open Access Journals (Sweden)

    Obermayer-Pietsch B

    2002-01-01

    Full Text Available Osteoporose ist in hohem Maß genetisch determiniert. Neue Wege der molekularbiologischen Forschung haben sich in den letzten Jahren auf diesem Gebiet etabliert. "Gene mapping" mit polymorphen genetischen Markern auf der Suche nach Phänotyp-assoziierten Genen ist ein aufwendiges, aber vielversprechendes Verfahren und wird durch die Erkenntnisse des Human Genome Projects beschleunigt. So wurde jüngst u. a. das Low-density Lipoprotein 5-Gen als wichtig für den Knochenstoffwechsel identifiziert. Kandidaten-gene wie Hormonrezeptor-, Cytokin- oder Kollagen-Gene werden hinsichtlich ihrer Gen-Gen- und Gen-Umwelt- Interaktionen untersucht und erlauben neue funktionelle Einsichten in Erkrankungen des Knochenstoffwechsels. Mutationen der Kollagen-Gene sind bei einigen seltenen Erkrankungen, wie dem Osteoporose-Pseudogliom-Syndrom oder der Osteogenesis imperfecta gefunden worden, könnten aber auch für häufige Varianten von Bindegewebsstörungen wie der congenitalen Hüftdysplasie verantwortlich sein, die etwa 10 % der weiblichen kaukasischen Bevölkerung in unterschiedlichem Ausmaß betrifft. Osteoporose am Schenkelhals und erhöhte Gelenkslaxizität sowie andere generalisierte Veränderungen des Knochen- und Kollagenstoffwechsels können hier möglicherweise ebenfalls durch Störungen des Kollagen I alpha 1-Gens erklärt werden. In Summe können wir zahlreiche neue Einsichten in die Pathophysiologie des Skelettsystems erwarten, die uns auch neue Zugangswege für Diagnostik und Therapie unserer Patienten ermöglichen werden.

  1. CLILiG und Musikunterricht

    Directory of Open Access Journals (Sweden)

    Merle Jung

    2015-10-01

    Full Text Available Der Einsatz von Musik und Liedern im Sprachunterricht ist seit der Entwicklung der kommunikativen Methoden ein beliebtes Thema in der Fremdsprachendidaktik. Musik und Sprache haben Ähnlichkeiten bei den kognitiven Verarbeitungsprozessen und der gedächtnisstützende Einfluss der Musik und ihr Nutzen für das Sprachenlernen sind allgemein bekannt. Dieser Nutzen wird aber meistens nur aus der (fremdsprachlichen Perspektive gezogen, die musikalische Erziehung der Lernenden bleibt im Hintergrund. Dabei bietet der bilinguale Musikunterricht mit der klaren Ausrichtung auf die musikalischen Ziele eine gute Möglichkeit, diese zwei Bereiche – Musik und Sprache – gleichwertig miteinander zu verbinden. Das Ziel des vorliegenden Beitrags ist es, die Vorteile des bilingualen Musikunterrichts zu erörtern und an einem Beispielmodul zum Thema Wetter im Herbst zu verdeutlichen. The use of music and songs in language teaching has been a popular topic in foreign language didactics since the development of communicative methods. Music and language have similarities in cognitive processing and the memory supporting influence of music and its beneficial effect on language learning are generally known. However, this benefit will usually be drawn only from the (foreign language perspective, the musical education of the learners remains in the background. Yet bilingual music education with a clear focus on the musical goals provides a great opportunity to connect these two areas - music and language - equally to each other. The aim of this paper is to discuss the advantages of bilingual music education and to present an example based on the bilingual module Weather in Autumn.

  2. Water quality and management - the use of models for the estimation of the hazard potential for groundwater by organic pollutants in solid waste; Gewaesserguete und Wasserwirtschaft - Anwendung von Modellen zur Abschaetzung der Grundwassergefaehrdung durch organische Stoffe aus Reststoffen

    Energy Technology Data Exchange (ETDEWEB)

    Klein, M.

    2000-08-31

    In this study the deterministic leaching model PELMO was extended in order to consider two additional transport processes (fast transport via the macro porous flow system without equilibrium conditions with respect to sorption, and transport of pollutants in the soil water bound to humic substances). The extended model was implemented into the stochastic estimation model MCPELMO 2.0. The new development has built in 22 leaching scenarios based on a combination of the German soil regions map (12 soil regions) and 9 representative weather stations. As daily temperature and precipitation data over a period of 30 years were available the influence of climatic fluctuations on the percaloate concentrations could be considered. In parallel to the model development nomograms were calculated based on the algorithms of MCPELMO 2.0 making it possible to estimate concentrations in leachate also graphically. The results of the MCPELMO 2.0 simulations were compared with comprehensive simulations over a period of 1000 years performed with the computer model PELMO. The analysis showed that the screening model MCPELMO 2.0 that was orders of magnitude faster than PELMO was nevertheless able to estimate concentrations close to PELMO for most of the substances. It was additionally concluded that the results of the estimation model behave conservative compared to the comprehensive simulations: MCPELMO is often slightly overestimating pollutant concentrations in the percolate. Only for pollutants having KOC values above 5000 L/kg and DT50 numbers above 2000 days MCPELMO was estimating lower concentrations in the percolate than PELMO. (orig.) [German] In diesem Vorhaben wurde das deterministische Versickerungsmodell PELMO um zwei zusaetzliche Transportprozesse erweitert (schneller Stofftransport ueber das Makroporensystem ohne Einstellung von Sorptionsgleichgewichten, sowie Transport von Stoffen im Bodenwasser gebunden an Huminsaeuren) und das erweiterte Modell in das stochastische

  3. Strategische Beschaffung: Grundlagen, Planung und Umsetzung eines integrierten Supply Management

    NARCIS (Netherlands)

    van Weele, A.J.; Eßig, M.

    2017-01-01

    Dieses Buch bietet – erstmalig in deutscher Übersetzung – eine umfassende und sehr anschauliche Darstellung zu Grundlagen, Planung und Umsetzung einer modernen Beschaffungsfunktion. Beschaffung und Supply Management werden dabei als wesentliches Bindeglied innerhalb des Managementsystems eines

  4. Theoriebedingte Wörterbuchform- probleme und wörterbuch ...

    African Journals Online (AJOL)

    zunehmend mehr neue Elemente der Wörterbuchform im Vorspann, im Wörterverzeichnis und im. Nachspann ...... tur und -architektur aufweisen und sich nur quantitativ bei den überdachten ...... modernen Printwörterbüchern. Lexikos 18: ...

  5. Emil Fahrenkamp : Bauten und Projekte für Berlin

    NARCIS (Netherlands)

    Jacob, B.

    2006-01-01

    Thema der vorliegenden Arbeit ist die umfassende Aufarbeitung und Dokumentation der Bauten und Projekte Emil Fahrenkamps (*1885, 1966) in Berlin und Potsdam-Babelsberg sowie die kritische Einordnung seiner Arbeiten in den Kontext der Baugeschichte des 20. Jahrhunderts. Den zentralen

  6. [Preussen und Livland im Zeichen der Reformation] / Anti Selart

    Index Scriptorium Estoniae

    Selart, Anti, 1973-

    2015-01-01

    Arvustus: Preussen und Livland im Zeichen der Reformation. Hrsg. von Arno Mentzel-Reuters und Klaus Neitmann. (Tagungsberichte der Historischen Kommission für ost- und westpreussische Landesforschung, 28). Fibre Verlag. Osnabrück 2014

  7. [Geisteswissenschaft und Publizistik im Baltikum des 19. und frühen 20. Jahrhunderts] / Manfred von Boetticher

    Index Scriptorium Estoniae

    Boetticher, Manfred von, 1947-

    2012-01-01

    Arvustus: Geisteswissenschaft und Publizistik im Baltikum des 19. und frühen 20. Jahrhunderts (Schriften der Baltischen Historischen Kommission, 17; Baltische Biographische Forschungen, 1). Hrsg. von Norbert Angermann, Wilhelm Lenz und Konrad Maier. (Berlin: LIT-Varlag, 2011)

  8. Entwicklung und Anwendung neuer NMR-Methoden: Orientierungsmedien zur Strukturbestimmung mit anisotropen Parametern und Metabonomics

    OpenAIRE

    Büchler, Silke

    2014-01-01

    Das Ziel dieser Arbeit war die Entwicklung und Anwendung neuer Orientierungsmedien zur Strukturbestimmung mit anisotropen Parametern, sowie die Etablierung von Metabonomics-Studien an Flüssigzellkulturen und Reispflanzen.

  9. On-line conformal HDR dose escalation trial in prostate cancer

    International Nuclear Information System (INIS)

    Martinez, Alvaro; Stromberg, Jannifer; Edmundson, Gregory; Gustafson, Gary; Vicini, Frank; Brabbins, Donald

    1996-01-01

    Purpose: To improve treatment results on prostatic adenocarcinoma, we began the first prospective Phase I/II dose-escalating clinical trial of conformal brachytherapy (CB) and concurrent external beam irradiation. Methods and Materials: Fifty-four patients with T2b-T3c prostatic adenocarcinoma received 172 transperineal conformal high-dose rate (HDR) boost implants. All patients received concomitant external beam pelvic irradiation. Dose escalation of the three HDR fractions were: 5.5 Gy (18 patients), 6 Gy (15 patients), and 6.5 Gy (21 patients). The urethra, anterior rectal wall, and prostate boundaries were identified individually and outlined at 5 mm intervals from the base to the apex of the gland. The CB using real-time ultrasound guidance with interactive online isodose distributions was performed on an outpatient basis. As needles were placed into the prostate, corrections for prostate displacement were recorded and the isodose distributions were recalculated to represent the new relationship between the needles, prostate, and normal structures. Results: Craniocaudal motion of the gland ranged from 0.5-2.0 cm (mean=1.0 cm), whereas lateral displacement was 0.1-0.4 cm. With the interactive online planning system, organ motion was immediately detected, accounted for, and corrected prior to each HDR treatment. The rectal dose has ranged from 45 to 87%, and the urethral dose from 97 to 112% of the prostate dose. Negative prostatic biopsies at 18 months were seen in (30(32)) patients. Biochemical (PSA <1.5 ng/ml) control at 36 months is is 89%. It is significant that operator dependence has been completely removed because the interactive online planning system uniformly guides the physicians. Conclusions: With ultrasound guidance and the interactive online dosimetry system, organ motion is insignificant because it can be corrected during the procedure. Common pitfalls of brachytherapy, including operator dependence and difficulty with reproducibility, have been

  10. SU-E-T-149: Brachytherapy Patient Specific Quality Assurance for a HDR Vaginal Cylinder Case

    Energy Technology Data Exchange (ETDEWEB)

    Barbiere, J; Napoli, J; Ndlovu, A [Hackensack Univ Medical Center, Hackensack, NJ (United States)

    2015-06-15

    Purpose: Commonly Ir-192 HDR treatment planning system commissioning is only based on a single absolute measurement of source activity supplemented by tabulated parameters for multiple factors without independent verification that the planned distribution corresponds to the actual delivered dose. The purpose on this work is to present a methodology using Gafchromic film with a statistically valid calibration curve that can be used to validate clinical HDR vaginal cylinder cases by comparing the calculated plan dose distribution in a plane with the corresponding measured planar dose. Methods: A vaginal cylinder plan was created with Oncentra treatment planning system. The 3D dose matrix was exported to a Varian Eclipse work station for convenient extraction of a 2D coronal dose plane corresponding to the film position. The plan was delivered with a sheet of Gafchromic EBT3 film positioned 1mm from the catheter using an Ir-192 Nucletron HDR source. The film was then digitized with an Epson 10000 XL color scanner. Film analysis is performed with MatLab imaging toolbox. A density to dose calibration curve was created using TG43 formalism for a single dwell position exposure at over 100 points for statistical accuracy. The plan and measured film dose planes were registered using a known dwell position relative to four film marks. The plan delivered 500 cGy to points 2 cm from the sources. Results: The distance to agreement of the 500 cGy isodose between the plan and film measurement laterally was 0.5 mm but can be as much as 1.5 mm superior and inferior. The difference between the computed plan dose and film measurement was calculated per pixel. The greatest errors up to 50 cGy are near the apex. Conclusion: The methodology presented will be useful to implement more comprehensive quality assurance to verify patient-specific dose distributions.

  11. SU-E-T-169: Characterization of Pacemaker/ICD Dose in SAVI HDR Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kalavagunta, C; Lasio, G; Yi, B; Zhou, J; Lin, M [Univ. of Maryland School Of Medicine, Baltimore, MD (United States)

    2015-06-15

    Purpose: It is important to estimate dose to pacemaker (PM)/Implantable Cardioverter Defibrillator (ICD) before undertaking Accelerated Partial Breast Treatment using High Dose Rate (HDR) brachytherapy. Kim et al. have reported HDR PM/ICD dose using a single-source balloon applicator. To the authors knowledge, there have so far not been any published PM/ICD dosimetry literature for the Strut Adjusted Volume Implant (SAVI, Cianna Medical, Aliso Viejo, CA). This study aims to fill this gap by generating a dose look up table (LUT) to predict maximum dose to the PM/ICD in SAVI HDR brachytherapy. Methods: CT scans for 3D dosimetric planning were acquired for four SAVI applicators (6−1-mini, 6−1, 8−1 and 10−1) expanded to their maximum diameter in air. The CT datasets were imported into the Elekta Oncentra TPS for planning and each applicator was digitized in a multiplanar reconstruction window. A dose of 340 cGy was prescribed to the surface of a 1 cm expansion of the SAVI applicator cavity. Cartesian coordinates of the digitized applicator were determined in the treatment leading to the generation of a dose distribution and corresponding distance-dose prediction look up table (LUT) for distances from 2 to 15 cm (6-mini) and 2 to 20 cm (10–1).The deviation between the LUT doses and the dose to the cardiac device in a clinical case was evaluated. Results: Distance-dose look up table were compared to clinical SAVI plan and the discrepancy between the max dose predicted by the LUT and the clinical plan was found to be in the range (−0.44%, 0.74%) of the prescription dose. Conclusion: The distance-dose look up tables for SAVI applicators can be used to estimate the maximum dose to the ICD/PM, with a potential usefulness for quick assessment of dose to the cardiac device prior to applicator placement.

  12. Palliative interstitial HDR brachytherapy for recurrent rectal cancer. Implantation techniques and results

    International Nuclear Information System (INIS)

    Kolotas, C.; Roeddiger, S.; Martin, T.; Tselis, N.; Baltas, D.; Zamboglou, N.; Strassmann, G.; Aebersold, D.M.

    2003-01-01

    Purpose: To report the methods and clinical results of CT-based interstitial high-dose-rate (HDR) brachytherapy procedures for the palliative treatment of recurrent rectal cancer. Patients and Methods: A total of 44 brachytherapy implants were performed in 38 patients. CT-guided catheter implants were performed in 34 patients under local anesthesia and sedation, and four patients were implanted intraoperatively. Of 40 CT-guided implants, 20 were done using metallic needles introduced via the sacrum and 20 were transperineal implants of plastic tubes in the presacral region. Postimplant CT scans were used for three-dimensional (3-D) conformal brachytherapy planning. Patients implanted with metallic needles were given a single fraction of 10-15 Gy using HDR 192 Ir, and those who received transperineal implants of plastic catheters were given fractionated brachytherapy, 5 Gy twice daily to a total dose of 30-40 Gy. The median tumor volume was 225 cm 3 with a range of 41-2,103 cm 3 . Results: After a median follow-up of 23.4 months, a total of 13/38 patients were alive. The median postbrachytherapy survival was 15 months with 18 of the 25 deaths due to distant metastases. Tumor response was as follows: 6/38 partial remission, 28/38 stable disease, and 4/38 local progression. A planning target volume (PTV) coverage > 85% was achieved in 42/44 implants. The treatment was well tolerated, and no acute complications were observed. One patient developed a fistula after 8 months. Pain relief was recorded in 34 patients (89.5%), and the median duration of this palliative effect was 5 months with a range of 1-13 months. Conclusions: Interstitial HDR brachytherapy is a valuable tool for the delivery of high doses and achieves effective palliation in recurrent rectal carcinoma. (orig.)

  13. Palliative interstitial HDR brachytherapy for recurrent rectal cancer. Implantation techniques and results

    Energy Technology Data Exchange (ETDEWEB)

    Kolotas, C. [Dept. of Radiation Oncology, Offenbach Hospital, Offenbach (Germany); Dept. of Radio-Oncology, Univ. of Bern, Inselspital, Bern (Switzerland); Roeddiger, S.; Martin, T.; Tselis, N.; Baltas, D.; Zamboglou, N. [Dept. of Radiation Oncology, Offenbach Hospital, Offenbach (Germany); Strassmann, G. [Dept. of Radiotherapy, Univ. Hospital, Philipps Univ., Marburg (Germany); Aebersold, D.M. [Dept. of Radio-Oncology, Univ. of Bern, Inselspital, Bern (Switzerland)

    2003-07-01

    Purpose: To report the methods and clinical results of CT-based interstitial high-dose-rate (HDR) brachytherapy procedures for the palliative treatment of recurrent rectal cancer. Patients and Methods: A total of 44 brachytherapy implants were performed in 38 patients. CT-guided catheter implants were performed in 34 patients under local anesthesia and sedation, and four patients were implanted intraoperatively. Of 40 CT-guided implants, 20 were done using metallic needles introduced via the sacrum and 20 were transperineal implants of plastic tubes in the presacral region. Postimplant CT scans were used for three-dimensional (3-D) conformal brachytherapy planning. Patients implanted with metallic needles were given a single fraction of 10-15 Gy using HDR {sup 192}Ir, and those who received transperineal implants of plastic catheters were given fractionated brachytherapy, 5 Gy twice daily to a total dose of 30-40 Gy. The median tumor volume was 225 cm{sup 3} with a range of 41-2,103 cm{sup 3}. Results: After a median follow-up of 23.4 months, a total of 13/38 patients were alive. The median postbrachytherapy survival was 15 months with 18 of the 25 deaths due to distant metastases. Tumor response was as follows: 6/38 partial remission, 28/38 stable disease, and 4/38 local progression. A planning target volume (PTV) coverage > 85% was achieved in 42/44 implants. The treatment was well tolerated, and no acute complications were observed. One patient developed a fistula after 8 months. Pain relief was recorded in 34 patients (89.5%), and the median duration of this palliative effect was 5 months with a range of 1-13 months. Conclusions: Interstitial HDR brachytherapy is a valuable tool for the delivery of high doses and achieves effective palliation in recurrent rectal carcinoma. (orig.)

  14. Implementation of microsource high dose rate (mHDR) brachytherapy in developing countries

    International Nuclear Information System (INIS)

    2001-11-01

    Brachytherapy using remote afterloading of a single high dose rate 192 Ir microsource was developed in the 1970s. After its introduction to clinics, this system has spread rapidly among developed Member States and has become a highly desirable modality in cancer treatment. This technique is now gradually being introduced to the developing Member States. The 192 Ir sources are produced with a high specific activity. This results in a high dose rate (HDR) to the tumour and shorter treatment times. The high specific activity simultaneously results in a much smaller source (so-called micro source, around I mm in diameter) which may be easily inserted into tissue through a thin delivery tube, the so-called interstitial treatment, as well as easily inserted into body cavities, the so-called intracavitary or endoluminal treatment. Another advantage is the ability to change dwell time (the time a source remains in one position) of the stepping source which allows dose distribution to match the target volume more closely. The purpose of this TECDOC is to advise radiation oncologists, medical physicists and hospital administrators in hospitals which are planning to introduce 192 Ir microsource HDR (mHDR) remote afterloading systems. The document supplements IAEA-TECDOC-1040, Design and Implementation of a Radiotherapy Programme: Clinical, Medical Physics, Radiation Protection and Safety Aspects, and will facilitate implementation of this new brachytherapy technology, especially in developing countries. The operation of the system, 'how to use the system', is not within the scope of this document. This TECDOC is based on the recommendations of an Advisory Group meeting held in Vienna in April 1999

  15. Westinghouse-GOTHIC distributed parameter modelling for HDR test E11.2

    International Nuclear Information System (INIS)

    Narula, J.S.; Woodcock, J.

    1994-01-01

    The Westinghouse-GOTHIC (WGOTHIC) code is a sophisticated mathematical computer code designed specifically for the thermal hydraulic analysis of nuclear power plant containment and auxiliary buildings. The code is capable of sophisticated flow analysis via the solution of mass, momentum, and energy conservation equations. Westinghouse has investigated the use of subdivided noding to model the flow patterns of hydrogen following its release into a containment atmosphere. For the investigation, several simple models were constructed to represent a scale similar to the German HDR containment. The calculational models were simplified to test the basic capability of the plume modeling methods to predict stratification while minimizing the number of parameters. A large empty volume was modeled, with the same volume and height as HDR. A scenario was selected that would be expected to stably stratify, and the effects of noding on the prediction of stratification was studied. A single phase hot gas was injected into the volume at a height similar to that of HDR test E11.2, and there were no heat sinks modeled. Helium was released into the calculational models, and the resulting flow patterns were judged relative to the expected results. For each model, only the number of subdivisions within the containment volume was varied. The results of the investigation of noding schemes has provided evidence of the capability of subdivided (distributed parameter) noding. The results also showed that highly inaccurate flow patterns could be obtained by using an insufficient number of subdivided nodes. This presents a significant challenge to the containment analyst, who must weigh the benefits of increased noding with the penalties the noding may incur on computational efficiency. Clearly, however, an incorrect noding choice may yield erroneous results even if great care has been taken in modeling accurately all other characteristics of containments. (author). 9 refs., 9 figs

  16. SU-F-T-63: Dosimetric Relevance of the Valencia and Leipzig HDR Applicators Plastic Cap

    Energy Technology Data Exchange (ETDEWEB)

    Granero, D [ERESA-Hospital General Universitario, Valencia (Spain); Candela-Juan, C [National Dosimetry Centre (CND), Valencia (Spain); Vijande, J; Ballester, F [University of Valencia, Burjassot (Spain); Perez-Calatayud, J [Hospital La Fe, Valencia (Spain); Jacob, D; Mourtada, F [Helen F. Graham Cancer Center, Christiana Care Health System, Newark, DE (United States)

    2016-06-15

    Purpose: Utilization of HDR brachytherapy treatment of skin lesions using collimated applicators, such as the Valencia or Leipzig is increasing. These applicators are made of cup-shaped tungsten material in order to focalize the radiation into the lesion and to protect nearby tissues. These applicators have an attachable plastic cap that removes secondary electrons generated in the applicator and flattens the treatment surface. The purpose of this study is to examine the dosimetric impact of this cap, and the effect if the cap is not placed during the HDR fraction delivery. Methods: Monte Carlo simulations have been done using the code Geant4 for the Valencia and Leipzig applicators. Dose rate distributions have been obtained for the applicators with and without the plastic cap. An experimental study using EBT3 radiochromic film has been realized in order to verify the Monte Carlo results. Results: The Monte Carlo simulations show that absorbed dose in the first millimeter of skin can increase up to 180% for the Valencia applicator if the plastic cap is absent and up to 1500% for the Leipzig applicators. At deeper distances the increase of dose is smaller being about 10–15%. Conclusion: Important differences have been found if the plastic cap of the applicators is absent in the treatment producing an overdosage in the skin. The user should have a checklist to remind him check always before HDR fraction delivery to insure the plastic cap is placed on the applicator. This work was supported in part by Generalitat Valenciana under Project PROMETEOII/2013/010, by the Spanish Government under Project No. FIS2013-42156, and by a research agreement with Elekta Brachytherapy, Veenendaal, The Netherlands.

  17. Salvage prostate HDR brachytherapy combined with interstitial hyperthermia for local recurrence after radiation therapy failure

    Energy Technology Data Exchange (ETDEWEB)

    Kukielka, A.M.; Hetnal, M.; Dabrowski, T.; Walasek, T.; Brandys, P.; Reinfuss, M. [Centre of Oncology, M. Sklodowska - Curie Institute, Krakow Branch, Department of Radiotherapy, Krakow (Poland); Nahajowski, D.; Kudzia, R.; Dybek, D. [Centre of Oncology, M. Sklodowska - Curie Institute, Krakow Branch, Department of Medical Physics, Department of Radiotherapy, Krakow (Poland)

    2014-02-15

    The aim of the present retrospective study is to evaluate toxicity and early clinical outcomes of interstitial hyperthermia (IHT) combined with high-dose rate (HDR) brachytherapy as a salvage treatment in patients with biopsy-confirmed local recurrence of prostate cancer after previous external beam radiotherapy. Between September 2008 and March 2013, 25 patients with local recurrence of previously irradiated prostate cancer were treated. The main eligibility criteria for salvage prostate HDR brachytherapy combined with interstitial hyperthermia were biopsy confirmed local recurrence and absence of nodal and distant metastases. All patients were treated with a dose of 30 Gy in 3 fractions at 21-day intervals. We performed 62 hyperthermia procedures out of 75 planned (83 %). The aim of the hyperthermia treatment was to heat the prostate to 41-43 C for 60 min. Toxicity for the organs of the genitourinary system and rectum was assessed according to the Common Terminology Criteria for Adverse Events (CTCAE, v. 4.03). Determination of subsequent biochemical failure was based on the Phoenix definition (nadir + 2 ng/ml). The median age was 71 years (range 62-83 years), the median initial PSA level was 16.3 ng/ml (range 6.37-64 ng/ml), and the median salvage PSA level was 2.8 ng/ml (1.044-25.346 ng/ml). The median follow-up was 13 months (range 4-48 months). The combination of HDR brachytherapy and IHT was well tolerated. The most frequent complications were nocturia, weak urine stream, urinary frequency, hematuria, and urgency. Grade 2 rectal hemorrhage was observed in 1 patient. No grade 3 or higher complications were observed. The 2-year Kaplan-Meier estimate of biochemical control after salvage treatment was 74 %. The PSA in 20 patients decreased below the presalvage level, while 11 patients achieved a PSA nadir < 0.5 ng/ml. All patients are still alive. Of the 7 patients who experienced biochemical failure, bone metastases were found in 2 patients. IHT in combination

  18. Is there any place for LDR brachytherapy for head and neck carcinomas in HDR era?

    Science.gov (United States)

    Fijuth, Jacek

    2009-03-01

    In Poland, the classical LDR brachytherapy for head and neck carcinomas with Ir-192 wires or hairpins has completely disappeared some time ago after 30 years of successful clinical use. Can this technique be fully and safely replaced by HDR or PDR application? This option seems attractive because of new possibilities of 3D reconstruction and computer real-time treatment planning and optimization. However, in my opinion, long time is needed to get a clinical and scientific experience that has been accumulated for decades with the use of LDR technique.

  19. Speedup of optimization-based approach to local backlight dimming of HDR displays

    DEFF Research Database (Denmark)

    Burini, Nino; Nadernejad, Ehsan; Korhonen, Jari

    2012-01-01

    Local backlight dimming in Liquid Crystal Displays (LCD) is a technique for reducing power consumption and simultaneously increasing contrast ratio to provide a High Dynamic Range (HDR) image reproduction. Several backlight dimming algorithms exist with focus on reducing power consumption, while...... other algorithms aim at enhancing contrast, with power savings as a side effect. In our earlier work, we have modeled backlight dimming as a linear programming problem, where the target is to minimize the cost function measuring the distance between ideal and actual output. In this paper, we propose...

  20. Klimaanpassung in Land- und Forstwirtschaft: Ergebnisse eines Workshops der Ressortforschungsinstitute FLI, JKI und Thünen-Institut

    OpenAIRE

    Schimmelpfennig, Sonja; Heidecke, Claudia; Beer, Holger; Bittner, Florian; Klages, Susanne; Krengel, Sandra; Lange, Stefan

    2018-01-01

    Das Working Paper stellt die Ergebnisse einer Umfrage und eines Workshops zusammen, die von Wissenschaftlern und Wissenschaftlerinnen der Ressortforschungsinstitute Thünen-Institut, Julius Kühn-Institut (JKI) und Friedrich-Loeffler-Institut (FLI) im Herbst 2016 zusammengetragen und diskutiert worden sind. Ziel des Workshops und der Umfrage war, den Stand des Wissens zu Klimaanpassungsthemen in der Ressortforschung des BMEL und die zukünftigen Herausforderungen einer Anpassung an den Klimawand...

  1. Geschmackspapillendichte und Geschmackswahrnehmung bei Jugendlichen mit Essstörungen und einer gesunden Kontrollgruppe

    OpenAIRE

    Kaltenhofer, Alice

    2009-01-01

    Fragestellung Die Schmeckwahrnehmung wird u.a. über Lernprozesse, kognitive Vorgänge, genetische und biochemische Faktoren reguliert. Ess- und Diätverhalten werden durch sie beeinflusst. Den anatomisch und physiologisch ersten Abschnitt der Schmeckwahrnehmung bilden die fungiformen Geschmackspapillen. In den Geschmackspapillen liegen die Geschmacksknopsen, mit deren Hilfe die Schmeckstoffe aufgenommen und in Form von Aktionspotentialen zum Thalamus, dem limbischen System,dem Gyrus postzentral...

  2. Kontrolle des Verwaltungsrates : eine Untersuchung der internen und externen Kontrollinstitutionen, -instrumente und -mechanismen

    OpenAIRE

    Reust, Dominik

    2014-01-01

    Eine wichtige Erkenntnis dieser Arbeit ist, dass eine effiziente und effektive Kontrolle des Verwaltungsrates nur über das Zusammenspiel der internen körperschaftlichen Kontrollinstitutionen und -instrumente mit den externen Kontrollinstitutionen und Kontrollmechanismen des Marktes erreicht wird. Die Vorschriften der VegüV betreffend transparente Entschädigungspolitik und unabhängige Stimmrechtsvertreter sowie die in der Aktienrechtsrevision angestrebte Stärkung der Informations-, Mitwirk...

  3. Recht und Rechtssystem als globale Struktur und Medium der Verhaltensorientierung / Raul Narits

    Index Scriptorium Estoniae

    Narits, Raul, 1952-

    2008-01-01

    Äratr.: Multiple Modernität, Globalisierung der Rechtsordnung und Kommunikationsstruktur der Rechtssysteme : Internationales Symposium zur Theorie der Rechtskommunikation an der Universität Tartu im April 2006 ; II. Sonderheft Estland. Berlin, 2008, lk. 219-238. - (Rechtstheorie : Zeitschrift für Logik und Juristische Methodenlehre, Rechtsinformatik, Kommunikationsforschung, Normen- und Handlungstheorie, Soziologie und Philosophie des Rechts ; Bd. 38, 2007, H. 2/3)

  4. Das Sabbatjahr für Lehrerinnen und Lehrer: Wer profitiert und in welcher Form?

    OpenAIRE

    Rothland, Martin

    2013-01-01

    Das Sabbatjahr für Lehrerinnen und Lehrer wird programmatisch als Maßnahme der Belastungsreduktion, der Regeneration sowie der Ressourcenstärkung diskutiert. Empirische Belege für die erwarteten Effekte finden sich jedoch kaum. Im Rahmen einer Längsschnittstudie mit drei Erhebungszeitpunkten vor, während und nach dem Sabbatjahr werden die Entwicklung der Belastungswahrnehmung, des Gesundheitszustands und allgemeiner sowie arbeitsbezogener Emotionen (Berufs- und Lebenszufriedenheit) auf der Ba...

  5. Referenzmodelle im Mobile Business: Analyse und Entwicklung neuer Rollen, Szenarien und Geschäftsmodelle

    OpenAIRE

    Hufenbach, Yvonne

    2016-01-01

    Das digitale Zeitalter ist charakterisiert durch sich stetig wandelnde Märkte, Techniken und wirtschaftliche Voraussetzungen. Klassische Wertschöpfungsketten brechen auf und wandeln sich zu Wertschöpfungsnetzen. Dabei findet eine Neuzuordnung zwischen Wertschöpfungstätigkeiten und Marktteilnehmern statt. Diese digitale Welt ist zudem durch hohe Interdependenzen wirtschaftlicher, informationstechnischer und rechtlicher Fragestellungen gekennzeichnet. Vor diesem Hintergrund verfolgt die Arb...

  6. Arbeitszeitflexibilisierung in der westdeutschen Metall- und Elektroindustrie und die Verbandsstrategien - Eine vergleichende Analyse der arbeitszeitpolitischen Strategien des Arbeitgeberverbandes Gesamtmetall und der Industriegewerkschaft Metall

    OpenAIRE

    Altun, Ufuk

    2005-01-01

    Arbeitszeitpolitik und Arbeitszeitgestaltung haben seit dem Tarifkompromiss im Jahre 1984 in der Metall-, und Elektroindustrie in der politischen und wissenschaftlichen Diskussion einen immensen Bedeutungszuwachs erfahren. Die Forderungen nach einer flexibleren Arbeitszeitgestaltung haben zeitgleich sowohl aus der Globalisierungsdiskussion und der Debatte um die Wettbewerbsfähigkeit des "Wirtschaftsstandorts Deutschland" heraus wie auch aus beschäftigungspolitischen Gründen neuen Auftrieb bek...

  7. MO-C-17A-11: A Segmentation and Point Matching Enhanced Deformable Image Registration Method for Dose Accumulation Between HDR CT Images

    International Nuclear Information System (INIS)

    Zhen, X; Chen, H; Zhou, L; Yan, H; Jiang, S; Jia, X; Gu, X; Mell, L; Yashar, C; Cervino, L

    2014-01-01

    Purpose: To propose and validate a novel and accurate deformable image registration (DIR) scheme to facilitate dose accumulation among treatment fractions of high-dose-rate (HDR) gynecological brachytherapy. Method: We have developed a method to adapt DIR algorithms to gynecologic anatomies with HDR applicators by incorporating a segmentation step and a point-matching step into an existing DIR framework. In the segmentation step, random walks algorithm is used to accurately segment and remove the applicator region (AR) in the HDR CT image. A semi-automatic seed point generation approach is developed to obtain the incremented foreground and background point sets to feed the random walks algorithm. In the subsequent point-matching step, a feature-based thin-plate spline-robust point matching (TPS-RPM) algorithm is employed for AR surface point matching. With the resulting mapping, a DVF characteristic of the deformation between the two AR surfaces is generated by B-spline approximation, which serves as the initial DVF for the following Demons DIR between the two AR-free HDR CT images. Finally, the calculated DVF via Demons combined with the initial one serve as the final DVF to map doses between HDR fractions. Results: The segmentation and registration accuracy are quantitatively assessed by nine clinical HDR cases from three gynecological cancer patients. The quantitative results as well as the visual inspection of the DIR indicate that our proposed method can suppress the interference of the applicator with the DIR algorithm, and accurately register HDR CT images as well as deform and add interfractional HDR doses. Conclusions: We have developed a novel and robust DIR scheme that can perform registration between HDR gynecological CT images and yield accurate registration results. This new DIR scheme has potential for accurate interfractional HDR dose accumulation. This work is supported in part by the National Natural ScienceFoundation of China (no 30970866 and no

  8. Osteopetrose - aktuelle Diagnostik und Therapie

    Directory of Open Access Journals (Sweden)

    Schulz AS

    2008-01-01

    Full Text Available Unter dem Begriff Osteopetrose wird eine heterogene Gruppe von Krankheiten zusammengefasst, die durch eine pathologisch vermehrte Knochenmasse charakterisiert ist. Diese Osteosklerose basiert in den meisten Fällen auf einem Defekt in der Knochenresorption durch Osteoklasten. Beim Menschen können mehrere Typen unterschieden und nach dem Vererbungsmodus, dem Manifestationsalter, der Schwere der klinischen Symptomatik und nach assoziierten Symptomen klassifiziert werden. Hauptformen sind die infantile "maligne" autosomal rezessive Osteopetrose (ARO, intermediäre autosomal rezessive Formen (IARO und milder verlaufende autosomal dominante Subtypen (ADO. In den letzten Jahren konnten mehrere zur Osteopetrose führende Genveränderungen identifiziert werden. Alle diese Genveränderungen bei humaner Osteopetrose betreffen Proteine, die an der Differenzierung oder Funktion der Osteoklasten beteiligt sind. Da die Osteoklasten sich aus der hämatopoietischen Stammzelle differenzieren, ist die hämatopoietische Stammzelltransplantation eine kurative Therapieoption bei schweren Osteopetroseformen. Allerdings ist diese Therapie mit erheblichen Risiken verbunden. Darüber hinaus sind bestimmte Subtypen der Osteopetrose mit schweren neurologischen Veränderungen assoziiert, die durch eine Stammzelltransplantation nicht positiv beeinflusst werden können. Ein genaues Verständnis der Pathogenese der humanen Osteopetrose ist daher wichtig für die Wahl der richtigen Therapie und gewährt darüber hinaus einen tieferen Einblick in die Physiologie and andere Pathologien des Knochens.

  9. Natur und Moderne um 1900

    DEFF Research Database (Denmark)

    , nordeuropäischen Vergleich widmen sich die Beiträge den medialen Repräsentationen von Natur (in Literatur, Philosophie, Film, Foto) ebenso wie der Kolonisierung des Raumes (in Tourismus, Reisen, Sport, Natur- und Heimatschutz). Der Band bietet damit auch Impulse für die neuen theoretisch-methodischen Ansätze der...

  10. Experimental work and know-how transfer in the framework of the individual project 'Earthquake investigations on the HDR reactor'

    International Nuclear Information System (INIS)

    Corvin, P.; Metz, K.

    1976-03-01

    In the framework of investigations to determine the earthquake resistance of nuclear power plant, carried out by the Applied Nucleonics Company on the HDR reactor in Grosswelzheim/Main, theoretical fundamentals and experimental test procedures in the sense of know-how transfer were elaborated. This enables the corresponding German institutions to carry out similar investigations on their own. In addition ANC carried out safety control measures during the investigations in order to prevent structural damage to the HDR reactor and neighbouring buildings. (orig.) 891 HP [de

  11. Evaluation of radiation doses on critical organs in the treatment of cancer of the cervix using HDR-brachytherapy

    International Nuclear Information System (INIS)

    Soares, Taciana; Jansem, Teresa

    2000-01-01

    High dose-rate (HDR) brachytherapy is one type of treatment of the cervix carcinoma. During the planning for this therapy, especial attention is given to proximal normal organs such as bladder and rectum. In fact, due to their radiosensibility and localization, bladder and rectum are considered as critical organs. In this work we have studied the influence of the positioning of patient legs in the dose delivered to these critical organs in the treatment of cancer of the cervix using HDR-brachytherapy. (author)

  12. In vitro-Permeationsstudien von hydrophilen und lipophilen Arzneistoffen an okularen Geweben und Zellkulturen

    OpenAIRE

    Scholz, Martina

    2003-01-01

    Da die Arzneistoffpermeation durch okulare Gewebe einen entscheidenden Einfluss auf die Heilung vieler Augenleiden hat, wurde die in vitro-Permeation hydrophiler und lipophiler Arzneistoffe durch okulare Gewebe und Zellkulturen in dieser Arbeit untersucht. Die Dissertation befasst sich vorrangig mit der Permeation des hydrophilen Modellarzneistoffs Pilocarpinhydrochlorid (P-HCl) durch isolierte Schweinecornea (SC), Schweinesklera, Kaninchenkonjunktiva und corneale bzw. konjunktivale Kan...

  13. Philologie im Horizont der Geschichtlichkeit von Sprache und Text: zum Tagungsband von Wulf Oesterreicher und Maria Selig

    Directory of Open Access Journals (Sweden)

    Olaf Müller

    2016-03-01

    Full Text Available Wulf Oesterreicher und Maria Selig, Hrsg., Geschichtlichkeit von Sprache und Text: Philologien – Disziplingenese – Wissenschaftshistoriographie (Paderborn: Wilhelm Fink, 2014, 332 S.

  14. Zoophilie in Zoologie und Roman: Sex und Liebe zwischen Mensch und Tier bei Plutarch, Plinius dem Älteren, Aelian und Apuleius

    Directory of Open Access Journals (Sweden)

    Judith Hindermann

    2011-09-01

    Full Text Available Die Bedeutung von Zoophilie in der antiken Literatur wurde bislang – mit Ausnahme des Mythos – kaum untersucht. Überblickt man die überlieferten literarischen Texte, fällt auf, dass Zoophilie ausserhalb des Mythos vor allem in zwei literarischen Gattungen auftritt : Einerseits in den zoologischen Schriften von Plutarch, Plinius dem Älteren und Aelian, andererseits im antiken Roman, d.h. in den Metamorphosen des Apuleius und im pseudo-lukianischen Onos. In diesem Beitrag soll untersucht werden, welche Funktion Zoophilie in den beiden literarischen Gattungen hat und wie die Autoren die sexuelle Praktik bewerten, die weder nach griechischem noch römischen Recht strafbar war. Da Vorstellungen über Tiere eng mit Gender und Geschlechterhierarchien verbunden sind, soll insbesondere die Frage berücksichtigt werden, inwiefern männliche und weibliche Verhaltens- und Rollenzuschreibungen bei der Darstellung zoophiler Akte wirksam werden.

  15. Recht und soziales Kapital im Wohlfahrtsstaat

    OpenAIRE

    Karstedt, Susanne

    1997-01-01

    'Das Konzept des sozialen Kapitals spielt eine zentrale Rolle in der Diskussion um den Um- und Abbau des Wohlfahrtsstaates. Zerstört der Wohlfahrtsstaat soziales Kapital? Können staatliche Sozialleistungen durch das soziale Kapital in Familien, Nachbarschaften und Gemeinden umstandslos ersetzt werden, und individuelle Rechtsansprüche als Forderungen an diese sozialen Netzwerke zurückverwiesen werden? Kann die angestrebte 'Verantwortungsgesellschaft' (Etzioni) die Leistungen übernehmen, mit de...

  16. Variationen und ihre Kompensation in CMOS Digitalschaltungen

    OpenAIRE

    Baumann, Thomas

    2010-01-01

    Variationen bei der Herstellung und während des Betriebs von CMOS Schaltungen beeinflussen deren Geschwindigkeit und erschweren die Verifikation der in der Spezifikation zugesicherten Eigenschaften. In dieser Arbeit wird eine abstraktionsebenenübergreifende Vorgehensweise zur Abschätzung des Einflusses von Prozess- und betriebsbedingten Umgebungsvariationen auf die Geschwindigkeit einer Schaltung vorgestellt. Neben Untersuchungen der Laufzeitsensitivität in low-power CMOS Technologien von...

  17. Von Medien, Übertragungen und Automaten

    Directory of Open Access Journals (Sweden)

    Alessandro Barberi

    2013-12-01

    Full Text Available Im Zuge der Debatten zum Medialen Habitus wurde vielfach betont, dass die >Theorie der Praxispraxeologischen Medientheorie< des Medialen Habitus avant la lettre gesprochen werden kann. Dieser Artikel untersucht – ausgehend von den Debatten zur "Medienkompetenz" – wie Bourdieu Sprache, Sprechen und Diskurs, sowie Akteure, Felder und Habitus als Medien begreift und betont dabei die Nützlichkeit der Bourdieuschen Bildungssoziologie im Rahmen einer sozialwissenschaftlichen Grundlegung der Medienpädagogik.

  18. Verletzungen und Fehlbeanspruchungen im leistungsorientierten Rudersport

    OpenAIRE

    Bussian, Marc Robert

    2004-01-01

    Die Stellung der Breitensportart Rudern als gesundheitsfördernde Sportform ist in der Literatur gleichlautend positiv beschrieben. Im leistungsorientierten Rudersport müssen neben den Verletzungen und Fehlbeanspruchungen der eigentlichen Sportart die unabdingbaren Nebentrainingsformen berücksichtigt werden. In den neunziger Jahren vollzog sich ein trainingsmethodischer Wandel, die Einführung eines erschwinglichen Rudersimulators und eine technische Weiterentwicklung im Boots- und Ruderbau. Ei...

  19. Pflege und Beruf: ungleiche Chancen der Vereinbarkeit

    OpenAIRE

    Keck, Wolfgang

    2011-01-01

    Die Vereinbarkeit von Beruf und Pflege wird in der Öffentlichkeit zu wenig thematisiert. Pflegende in einkommensschwachen Familien können sich keine zusätzlichen Pflegedienste leisten und müssen häufiger Einschnitte im Beruf in Kauf nehmen. Beschäftigte in unteren Hierarchieebenen können Beruf und Pflege nur schwer vereinbaren, da sie flexible Arbeitszeitregelungen seltener nutzen können.

  20. Polnische qualitative Soziologie: Entwicklung und Hauptthemen

    OpenAIRE

    Konecki, Krzysztof T.; Kacperczyk, Anna M.; Marciniak, Lukasz T.

    2005-01-01

    In dem vorliegenden Beitrag wird die Entwicklung der qualitativen Soziologie in Polen rekonstruiert, indem deren wesentliche intellektuelle Wurzeln und einige Hauptthemen der polnischen Soziologie vorgestellt werden. Romantizismus und die induktive Methode sind essenzielle Elemente für die Entwicklung der Disziplin in Polen gewesen und Charakteristika ihrer Besonderheit. Die Bedeutung von Florian ZNANIECKI für die Entstehung der polnischen qualitativen Soziologie wird gewürdigt. URN: urn:n...

  1. Bedeutung von Umwelt- und Organismusfaktoren bei Autoaggressionen

    OpenAIRE

    Rohmann, Ulrich H.; Elbing, Ulrich; Hartmann, Hellmut

    1988-01-01

    In der vorliegenden Arbeit werden übergeordnete Hypothesen zu autoaggressiven Verhaltensweisen formuliert, wobei prozeßhafte Abläufe von umweltbezogenen und organischen Variablen angenommen werden. Eine solche dynamische Beziehung hat ihre Bedeutung sowohl für verursachende als auch aufrechterhaltende Faktoren. In einer Querschnittuntersuchung lassen sich Korrelationen von Tageszeit- und Tätigkeitscharakteristiken (umweltbezogene Variablen) zur Autoaggressionshäufigkeit und Pulsfrequenz (Orga...

  2. Lehre 2.0 - Wie werden Social Media und Web 2.0 in die medizinische Ausbildung eingebunden? Ein systematischer Literaturüberblick [Education 2.0 - How has social media and Web 2.0 been integrated into medical education? A systematical literature review

    Directory of Open Access Journals (Sweden)

    Ückert, Frank

    2013-02-01

    Full Text Available [english] Objective: Present-day students have grown up with considerable knowledge concerning multi-media. The communication modes they use are faster, more spontaneous, and independent of place and time. These new web-based forms of information and communication are used by students, educators, and patients in various ways. Universities which have already used these tools report many positive effects on the learning behaviour of the students. In a systematic literature review, we summarized the manner in which the integration of Social Media and Web 2.0 into education has taken place. Method: A systematic literature search covering the last 5 years using MeSH terms was carried out via PubMed.Result: Among the 20 chosen publications, there was only one German publication. Most of the publications are from the US and Great Britain. The latest publications report on the concrete usage of the tools in education, including social networking, podcasts, blogs, wikis, YouTube, Twitter and Skype.Conclusion: The integration of Web 2.0 and Social Media is the modern form of self-determined learning. It stimulates reflection and actively integrates the students in the construction of their knowledge. With these new tools, the students acquire skills which they need in both their social and professional lives. [german] Zielsetzung: Die Studierenden sind mit einem hohen multimedialen Bezug aufgewachsen. Die von ihnen genutzten Kommunikationswege sind schneller, spontaner und unabhängig von Ort und Zeit geworden. Diese neuen webbasierten Informations- und Kommunikationswege werden von Studierenden, Lehrenden und Patienten in vielfältigen Weisen genutzt. Universitäten, die diese Tools in der Lehre einsetzten, berichten über viele positive Auswirkungen auf das Lernverhalten der Studierenden. In einer systematischen Literaturübersicht wird zusammengestellt, für welche Lehr- und Lernformen Social Media und Web 2.0 Tools in der derzeitigen medizinischen

  3. A multicentre ‘end to end’ dosimetry audit for cervix HDR brachytherapy treatment

    International Nuclear Information System (INIS)

    Palmer, Antony L.; Diez, Patricia; Gandon, Laura; Wynn-Jones, Andrea; Bownes, Peter; Lee, Chris; Aird, Edwin; Bidmead, Margaret; Lowe, Gerry; Bradley, David; Nisbet, Andrew

    2015-01-01

    Purpose: To undertake the first multicentre fully ‘end to end’ dosimetry audit for HDR cervix brachytherapy, comparing planned and delivered dose distributions around clinical treatment applicators, with review of local procedures. Materials and methods: A film-dosimetry audit was performed at 46 centres, including imaging, applicator reconstruction, treatment planning and delivery. Film dose maps were calculated using triple-channel dosimetry and compared to RTDose data from treatment planning systems. Deviations between plan and measurement were quantified at prescription Point A and using gamma analysis. Local procedures were also discussed. Results: The mean difference between planned and measured dose at Point A was −0.6% for plastic applicators and −3.0% for metal applicators, at standard uncertainty 3.0% (k = 1). Isodose distributions agreed within 1 mm over a dose range 2–16 Gy. Mean gamma passing rates exceeded 97% for plastic and metal applicators at 3% (local) 2 mm criteria. Two errors were found: one dose normalisation error and one applicator library misaligned with the imaged applicator. Suggestions for quality improvement were also made. Conclusions: The concept of ‘end to end’ dosimetry audit for HDR brachytherapy has been successfully implemented in a multicentre environment, providing evidence that a high level of accuracy in brachytherapy dosimetry can be achieved

  4. Verification of experimental modal modeling using HDR (Heissdampfreaktor) dynamic test data

    International Nuclear Information System (INIS)

    Srinivasan, M.G.; Kot, C.A.; Hsieh, B.J.

    1983-01-01

    Experimental modal modeling involves the determination of the modal parameters of the model of a structure from recorded input-output data from dynamic tests. Though commercial modal analysis algorithms are being widely used in many industries their ability to identify a set of reliable modal parameters of an as-built nuclear power plant structure has not been systematically verified. This paper describes the effort to verify MODAL-PLUS, a widely used modal analysis code, using recorded data from the dynamic tests performed on the reactor building of the Heissdampfreaktor, situated near Frankfurt, Federal Republic of Germany. In the series of dynamic tests on HDR in 1979, the reactor building was subjected to forced vibrations from different types and levels of dynamic excitations. Two sets of HDR containment building input-output data were chosen for MODAL-PLUS analyses. To reduce the influence of nonlinear behavior on the results, these sets were chosen so that the levels of excitation are relatively low and about the same in the two sets. The attempted verification was only partially successful in that only one modal model, with a limited range of validity, could be synthesized and in that the goodness of fit could be verified only in this limited range

  5. Quality control of the breast cancer treatments on Hdr brachytherapy with TLD-100

    Energy Technology Data Exchange (ETDEWEB)

    Torres H, F. [Universidad de Cordoba, Materials and Applied Physics Group, 230002 Monteria, Cordoba (Colombia); De la Espriella V, N. [Universidad de Cordoba, Grupo Avanzado de Materiales y Sistemas Complejos, 230002 Monteria, Cordoba (Colombia); Sanchez C, A., E-mail: franciscotorreshoyos@yahoo.com [Universidad de Cordoba, Departamento de Enfermeria, 230002 Monteria, Cordoba (Colombia)

    2014-07-01

    An anthropomorphic Phantom, a female trunk, was built with a natural bone structure and experimental material coated, glycerin and water-based material called JJT to build soft tissue equivalent to the muscle of human tissue, and a polymer (styrofoam) to build the lung as critical organ to simulate the treatment of breast cancer, with high dose rate brachytherapy (Hdr) and sources of Ir-192. The treatments were planned and calculated for the critical organ: Lung, and injury of 2 cm in diameter in breast with Micro Selectron Hdr system and the software Plato Brachytherapy V 14.1 of the Nucletron (Netherlands) which uses the standard protocol of radiotherapy for brachytherapy treatments. The dose experimentally measured with dosimeters TLD-100 LiF: Mg; Ti, which were previously calibrated, were placed in the same positions and bodies mentioned above, with less than 5% uncertainty. The reading dosimeters was carried out in a Harshaw TLD 4500. The results obtained for calculated treatments, using the standard simulator, and the experimental with TLD-100, show a high concordance, as they are on average a ± 1.1% making process becomes in a quality control of this type of treatments. (Author)

  6. Essential results of analyses accompanying the leak rate experiments E22 at HDR

    International Nuclear Information System (INIS)

    Grebner, H.; Hoefler, A.; Hunger, H.

    1997-01-01

    During phase III of the HDR Safety Programme (HDR: decommissioned overheated steam reactor in Karlstein, Germany), experiments were performed in test group E22 on small-bore austenitic straight piping and on pipe elbows and branches containing through-wall cracks. The main aim was the determination of crack opening and leak rate behaviour for the cracked components under almost operational pressure and temperature loading conditions, especially including transient bending moments. In addition to machined slits, naturally grown fatigue cracks were also considered to cover the leakage behaviour. The experiments were accompanied by calculations, mainly performed by GRS. The paper describes the most important aspects and the essential results of the calculations and analysis. The main outcome was that the crack opening and initiation of crack growth can be described with the finite element techniques applied with sufficient accuracy. However, the qualification of the leak rate models could not be completed successfully, and therefore more sophisticated experiments of this kind are needed. (orig.)

  7. Seismic tests at the HDR facility using explosives and solid propellant rockets

    International Nuclear Information System (INIS)

    Corvin, P.; Steinhilber, H.

    1981-01-01

    In blast tests the HDR reactor building and its mechanical equipment were subjected to earthquake-type excitations through the soil and the foundation. A series of six tests was carried out, two tests being made with HDR facility under operating conditions (BWR conditions, 285 0 C, 70 bar). The charges were placed in boreholes at a depth of 4 to 10 m and a distance of 16 to 25 m from the reactor building. The tests with solid propellant rockets were made in order to try a new excitation technique. The rockets used in these tests were of compact design and had a short combustion period (500 ms) at high constant thrust (100 kN per combustion chamber). These rockets were fixed to the concrete dome of the building in such a way that the thrust generated during the combustion of the propellant resulted in an impulsive load acting on the building. This type of excitation was selected with a view to investigating the global effects of the load case 'aircraft impact' on the building and the mechanical equipment. In the four tests made so far, up to four rockets were ignited simultaneously, so that the maximum impulse was 2 x 10 5 Ns. The excitation level can be markedly increased by adding further rockets. This excitation technique was characterised by excellent reproducibility of the load parameters. (orig./HP)

  8. Variability of Marker-Based Rectal Dose Evaluation in HDR Cervical Brachytherapy

    International Nuclear Information System (INIS)

    Wang Zhou; Jaggernauth, Wainwright; Malhotra, Harish K.; Podgorsak, Matthew B.

    2010-01-01

    In film-based intracavitary brachytherapy for cervical cancer, position of the rectal markers may not accurately represent the anterior rectal wall. This study was aimed at analyzing the variability of rectal dose estimation as a result of interfractional variation of marker placement. A cohort of five patients treated with multiple-fraction tandem and ovoid high-dose-rate (HDR) brachytherapy was studied. The cervical os point and the orientation of the applicators were matched among all fractional plans for each patient. Rectal points obtained from all fractions were then input into each clinical treated plan. New fractional rectal doses were obtained and a new cumulative rectal dose for each patient was calculated. The maximum interfractional variation of distances between rectal dose points and the closest source positions was 1.1 cm. The corresponding maximum variability of fractional rectal dose was 65.5%. The percentage difference in cumulative rectal dose estimation for each patient was 5.4%, 19.6%, 34.6%, 23.4%, and 13.9%, respectively. In conclusion, care should be taken when using rectal markers as reference points for estimating rectal dose in HDR cervical brachytherapy. The best estimate of true rectal dose for each fraction should be determined by the most anterior point among all fractions.

  9. Interactive, multi-modality image registrations for combined MRI/MRSI-planned HDR prostate brachytherapy

    Directory of Open Access Journals (Sweden)

    Galen Reed

    2011-03-01

    Full Text Available Purpose: This study presents the steps and criteria involved in the series of image registrations used clinically during the planning and dose delivery of focal high dose-rate (HDR brachytherapy of the prostate. Material and methods: Three imaging modalities – Magnetic Resonance Imaging (MRI, Magnetic Resonance Spectroscopic Imaging (MRSI, and Computed Tomography (CT – were used at different steps during the process. MRSI is used for identification of dominant intraprosatic lesions (DIL. A series of rigid and nonrigid transformations were applied to the data to correct for endorectal-coil-induced deformations and for alignment with the planning CT. Mutual information was calculated as a morphing metric. An inverse planning optimization algorithm was applied to boost dose to the DIL while providing protection to the urethra, penile bulb, rectum, and bladder. Six prostate cancer patients were treated using this protocol. Results: The morphing algorithm successfully modeled the probe-induced prostatic distortion. Mutual information calculated between the morphed images and images acquired without the endorectal probe showed a significant (p = 0.0071 increase to that calculated between the unmorphed images and images acquired without the endorectal probe. Both mutual information and visual inspection serve as effective diagnostics of image morphing. The entire procedure adds less than thirty minutes to the treatment planning. Conclusion: This work demonstrates the utility of image transformations and registrations to HDR brachytherapy of prostate cancer.

  10. Rechtspopulistische Einstellungen in Ost- und Westdeutschland

    Directory of Open Access Journals (Sweden)

    Beate Küpper

    2017-12-01

    Full Text Available Während sich die Mehrheit der Deutschen für Demokratie, Vielfalt und Gleichwertigkeit positioniert, sind zugleich rechtspopulistische Einstellungen lauter geworden. Der Beitrag berichtet über Befunde der Mitte-Studie der Friedrich-Ebert-Stiftung 2016 zu der Verbreitung rechtspopulistischer und rechtsextreme Einstellungen, wirft einen besonderen Blick auf potentielle Wähler_innen der AfD und diskutiert am Ende mögliche Erklärungen für die gefundenen Unterschiede zwischen Ost- und Westdeutschen.

  11. Implementation of the technique of partial irradiation accelerated the breast with high doses (HDR) brachytherapy; Puesta en marcha de la tecnica de irradiacion parcial acelerada de la mama con braquterapia de alta tasa de dosis (HDR)

    Energy Technology Data Exchange (ETDEWEB)

    Molina Lopez, M. Y.; Pardo Perez, E.; Castro Novais, J.; Martinez Ortega, J.; Ruiz Maqueda, S.; Cerro Penalver, E. del

    2013-07-01

    The objective of this work is presents procedure carried out in our Centre for the implementation of the accelerated partial breast irradiation (APBI, accelerated partial-breast irradiation) with high-rate brachytherapy (HDR), using plastic tubes as applicators. Carried out measures, the evaluation of the dosimetric parameters analyzing and presenting the results. (Author)

  12. A study of optimization techniques in HDR brachytherapy for the prostate

    Science.gov (United States)

    Pokharel, Ghana Shyam

    Several studies carried out thus far are in favor of dose escalation to the prostate gland to have better local control of the disease. But optimal way of delivery of higher doses of radiation therapy to the prostate without hurting neighboring critical structures is still debatable. In this study, we proposed that real time high dose rate (HDR) brachytherapy with highly efficient and effective optimization could be an alternative means of precise delivery of such higher doses. This approach of delivery eliminates the critical issues such as treatment setup uncertainties and target localization as in external beam radiation therapy. Likewise, dosimetry in HDR brachytherapy is not influenced by organ edema and potential source migration as in permanent interstitial implants. Moreover, the recent report of radiobiological parameters further strengthen the argument of using hypofractionated HDR brachytherapy for the management of prostate cancer. Firstly, we studied the essential features and requirements of real time HDR brachytherapy treatment planning system. Automating catheter reconstruction with fast editing tools, fast yet accurate dose engine, robust and fast optimization and evaluation engine are some of the essential requirements for such procedures. Moreover, in most of the cases we performed, treatment plan optimization took significant amount of time of overall procedure. So, making treatment plan optimization automatic or semi-automatic with sufficient speed and accuracy was the goal of the remaining part of the project. Secondly, we studied the role of optimization function and constraints in overall quality of optimized plan. We have studied the gradient based deterministic algorithm with dose volume histogram (DVH) and more conventional variance based objective functions for optimization. In this optimization strategy, the relative weight of particular objective in aggregate objective function signifies its importance with respect to other objectives

  13. Editorial 01/2013 Normen und Normierungen

    Directory of Open Access Journals (Sweden)

    Christian Swertz

    2013-03-01

    Full Text Available Auf unterschiedlichsten Ebenen werden die Diskussionen und Forschungen der Medienpädagogik von normativ aufgeladenen Begriffen durchzogen: so, wenn es um Standards in der Medienbildung geht, wenn beispielsweise diskutiert wird, welche Inhalte in welcher Form vermittelt werden sollen; so auch wenn zur Debatte steht, wie Medienpädagogik institutionalisiert werden sollte und welche Voraussetzungen gegeben sein müssen, um einen geplanten Bildungsprozess zu lenken oder anzuleiten.Derartige Norm(ierungen wurden bereits mit der Konzeptualisierung des Begriffs Medienkompetenz und im Blick auf die Emanzipation des Menschen kritisch beleuchtet, womit auch Kritik an gesellschaftlichen Herrschafts- und Machtstrukturen verbunden war. Die Orientierung an der sozialwissenschaftlich verstandenen Emanzipation des Menschen ist allerdings in anderen pädagogischen Disziplinen durchaus umstritten. Gleichzeitig ist zu beobachten, dass die gesellschaftskritische Perspektive im medienpädagogischen Diskurs über die Orientierung von Medienkompetenz und Medienbildung eine immer geringere Rolle spielt. Deshalb hat sich die Redaktion der MEDIENIMPULSE entschlossen, dem Thema Normen und Normierungen eine eigene Ausgabe zu widmen.Dabei sollten folgende Fragen behandelt werden:Wie sieht es mit Norm(ierungen im Bereich der Mediendidaktik aus? Wie sind die mit aktuellen Medienkompetenz- und Medienbildungsbegriffen verbundenen Normen epistemologisch und (medientheoretisch abgestützt? Wie lassen sich – nur scheinbar paradox formuliert – wissenschaftlich begründbare medienpädagogische Normen finden, die sich den genannten Normierungen widersetzen und entziehen? Inwiefern führt die Einführung von Laptopklassen oder Smartboards im schulischen Bereich oder die Gestaltung von Videospielprojekten in der außerschulischen Medienbildung zu einer unreflektierten Sozialdisziplinierung, die als illegitime Form(atierung des Menschen verstanden werden kann? Der Schwerpunktteil

  14. Medienpädagogik und die Digitale Gesellschaft im Spannungsfeld von Regulierung und Teilhabe

    Directory of Open Access Journals (Sweden)

    Stefan Iske

    2014-12-01

    Full Text Available Vor 25 Jahren stellte Tim Berners-Lee sein Konzept eines World Wide Web (WWW vor und legte damit einen der bedeutendsten Grundsteine der digitalen Vernetzung. Was ursprünglich zum Austausch von Informationen und Daten unter Forschenden entworfen wurde, hat sich zu einem umfassenden Kultur- und Bildungsraum entwickelt und ist ein universaler und zentraler Dienst des Internet geworden. Dieser gegenwärtige Status des Internet und des World Wide Web ist der vorläufige Zwischenstand einer historischen Entwicklung, der sowohl Transformationen und Veränderungen als auch Konstanten zugrunde liegen. Nicht erst zum diesjährigen Geburtstag des World Wide Web wird deutlich, dass durch digitale und vernetzte Technologien zentrale Kategorien wie Bildung, Erziehung und Sozialisation berührt werden. Beispielhaft kann auf die aktuellen Debatten über Regulierungsmechanismen im Internet wie auch auf die Enthüllungen Edward Snowdens hingewiesen werden. Aus dem Vorangehenden lassen sich medienpädagogische Fragestellungen ableiten, die zum Beispiel die Handlungsautonomie von Subjekten sowie Möglichkeitsräume der Mitgestaltung von und Teilhabe an Gesellschaft (Winter 2012, Swertz 2014 thematisieren. Zudem sind es Fragen der Mediensozialisation und der Konstruktion von Identität in digital vernetzten Räumen (Jörissen/Marotzki 2008, die sowohl bei der Theoriebildung als auch im Rahmen medienpädagogischer Praxis eine hohe Relevanz besitzen.

  15. Steueroasen und Regulierungsoasen – Auswirkungen auf die Stabilität des Finanzmarkts und politische Implikationen

    Directory of Open Access Journals (Sweden)

    Michaela Schmidt

    2012-12-01

    Full Text Available In diesem Beitrag wird dargelegt, dass Steuer- und Regulierungsoasen nicht nur Steuerausfälle und Kapitalflucht ermöglichen, sondern auch eine Hauptursache für die Finanzkrise 2007/2008 waren und weiterhin die Stabilität des Finanzmarkts gefährden. Sie haben den Boden bereitet für das Aufkommen nicht regulierter Finanzinstitutionen, sogenannter Schattenbanken. Regulierungsoasen ermöglichen Finanzmarktakteuren eine Umgehung von Regulierungs- und Aufsichtsvorschriften und heizen den Wettbewerb um niedrige Regulierungsvorschriften maßgeblich an. Jeder Schritt zu einer finanzpolitischen Re-Regulierung von Steuer- und Regulierungsoasen sowie Schattenbanken ist ein aktiver Schritt zur Krisenvorbeugung und damit zum Schutz der ArbeitnehmerInnen vor den gewaltigen volkswirtschaftlichen Kosten von Finanzkrisen.

  16. Pre- and post-calculations for crack opening and leak rate experiments on piping components within the HDR-program

    International Nuclear Information System (INIS)

    Grebner, H.; Hoefler, A.; Hunger, H.

    1991-01-01

    In this paper calculations to experiments on leak opening and leak rates of piping components are presented. The experiments are performed at the HDR-facility at Karlstein/Germany and up to now straight pipes and pipe branches were considered. Numerical and experimental results are compared. (author)

  17. Erfahrungen an der Schnittstelle von Medienarbeit und Praxisforschung

    Directory of Open Access Journals (Sweden)

    Peter Holzwarth

    2007-11-01

    Full Text Available Der Beitrag reflektiert die Verbindung von praktischer Medienarbeit und Forschung am Beispiel eines internationalen EU-Forschungsprojekts zum Thema Medien und Migration. Neben didaktischen Prinzipien und Konzepten für die aktive Medienarbeit im Forschungskontext geht es um die Kooperation von medienpädagogischer Begleitung (MB und wissenschaftlicher Begleitung (WB sowie um deren spezifische Kompetenzen.

  18. Leitung und Kooperation in wissenschaftlichen Bibliotheken Berlins - eine empirische Untersuchung

    OpenAIRE

    Paul, Gerhard

    1998-01-01

    Die vorliegende Arbeit greift ein im bibliotheks- und IuK-wissenschaftlichen sowie im fachprofessionellen Diskurs bisher weitgehend vernachlässigtes, aber immer bedeutsameres Thema auf: das vertikale soziale Geschehen in der Arbeitsorganisation ?wissenschaftliche Bibliothek". Die Absicht der Untersuchung lag darin, einen Zusammenhang zwischen dem Interaktionsverhalten der Leitungspersonen einerseits und der Mobilisierung von Leistungs- und Innovationspotentialen bei den Mitarbeiterinnen und M...

  19. [Sascha Möbius. Das Gedähtnis der Reichsstadt. Unruhen und Kriege in der lübeckischen Chronistik und Kriege und Erinnerungskultur des späten mittelalters und der frühen Neuzeit

    Index Scriptorium Estoniae

    Hormuth, Dennis

    2012-01-01

    Arvustus: Sascha Möbius. Das Gedähtnis der Reichsstadt. Unruhen und Kriege in der lübeckischen Chronistik und Kriege und Erinnerungskultur des späten mittelalters und der frühen Neuzeit. (Göttingen, 2011)

  20. Balloon-based adjuvant radiotherapy in breast cancer: comparison between {sup 99m}Tc and HDR {sup 192}Ir

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Tarcisio Passos Ribeiro de; Lima, Carla Flavia de; Cuperschmid, Ethel Mizrahy, E-mail: tprcampos@pq.cnpq.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)

    2016-03-15

    Objective: To perform a comparative dosimetric analysis, based on computer simulations, of temporary balloon implants with {sup 99m}Tc and balloon brachytherapy with high-dose-rate (HDR) {sup 192}Ir, as boosts to radiotherapy. We hypothesized that the two techniques would produce equivalent doses under pre-established conditions of activity and exposure time. Materials and methods: simulations of implants with {sup 99m}Tc-filled and HDR {sup 192}Ir-filled balloons were performed with the Siscodes/MCNP5, modeling in voxels a magnetic resonance imaging set related to a young female. Spatial dose rate distributions were determined. In the dosimetric analysis of the protocols, the exposure time and the level of activity required were specified. Results: the {sup 99m}Tc balloon presented a weighted dose rate in the tumor bed of 0.428 cGy.h{sup -1}.mCi{sup -1} and 0.190 cGyh{sup -1} at the balloon surface and at 8-10 mm from the surface, respectively, compared with 0.499 and 0.150 cGyh{sup -1}.mCi{sup -1}, respectively, for the HDR {sup 192}Ir balloon. An exposure time of 24 hours was required for the {sup 99m}Tc balloon to produce a boost of 10.14 Gy with 1.0 Ci, whereas only 24 minutes with 10.0 Ci segments were required for the HDR {sup 192}Ir balloon to produce a boost of 5.14 Gy at the same reference point, or 10.28 Gy in two 24-minutes fractions. Conclusion: temporary {sup 99m}Tc balloon implantation is an attractive option for adjuvant radiotherapy in breast cancer, because of its availability, economic viability, and similar dosimetry in comparison with the use of HDR {sup 192}Ir balloon implantation, which is the current standard in clinical practice. (author)

  1. Effect and toxicity of endoluminal high-dose-rate (HDR) brachytherapy in centrally located tumors of the upper respiratory tract

    International Nuclear Information System (INIS)

    Harms, W.; Wannenmacher, M.; Becker, H.; Herth, F.; Fritz, P.

    2000-01-01

    Aim: To assess effect an toxicity of high-dose-rate afterloading (HDR) alone or in combination with external beam radiotherapy (EBRT) in centrally located tumors of the upper respiratory tract. Patients and Methods: From 1987 to 1996, 55 patients were treated. Twenty-one patients (group A1: 17 non-small-cell lung cancer [NSCLC], A2: 4 metastases from other malignancies) were treated using HDR alone due to a relapse after external beam irradiation. In 34 previously untreated and inoperable patients (group B1: 27 NSCLC, B2: 7 metastases from other malignancies) HDR was given as a boost after EBRT (30 to 60 Gy, median 50). HDR was carried out with a 192 Ir source (370 GBq). The brachytherapy dose (group A: 5 to 27 Gy, median 20; B: 10 to 20 Gy, median 15) was prescribed to 1 cm distance from the source axis. A distanciable applicator was used in 39/55 patients. Results: In group A1, a response rate (CR, PR) of 53% (group B1: 77%) was reached. The median survival (Kaplan-Meier) was 5 months in group A1 (B1: 20 months). The 1-, 3- and 5-year local progression free survival rates (Kaplan-Meier) were 66% (15%), 52% (0%), and 37% (0%) in group B1 (group A1). Prognostic favorable factors in group B1 were a tumor diameter 70. Grade-1 or 2 toxicity (RTOG/EORTC) occurred in 0% in group A and in 6% in group B. We observed no Grad-3 or 4 toxicity. Complications caused by persistent or progressive local disease occurred in 3 patients in goup A (fatal hemorrhage, tracheomediastinal fistula, hemoptysis) and in 2 patients in group B (fatal hemorrhage, hemoptysis). Conclusions: HDR brachytherapy is an effective treatment with moderate side effects. In combination with external beam irradiation long-term remissions can be reached in one third of the patients. (orig.) [de

  2. Balloon-based adjuvant radiotherapy in breast cancer: comparison between 99mTc and HDR 192Ir

    Directory of Open Access Journals (Sweden)

    Tarcísio Passos Ribeiro de Campos

    2016-04-01

    Full Text Available Abstract Objective: To perform a comparative dosimetric analysis, based on computer simulations, of temporary balloon implants with 99mTc and balloon brachytherapy with high-dose-rate (HDR 192Ir, as boosts to radiotherapy. We hypothesized that the two techniques would produce equivalent doses under pre-established conditions of activity and exposure time. Materials and Methods: Simulations of implants with 99mTc-filled and HDR 192Ir-filled balloons were performed with the Siscodes/MCNP5, modeling in voxels a magnetic resonance imaging set related to a young female. Spatial dose rate distributions were determined. In the dosimetric analysis of the protocols, the exposure time and the level of activity required were specified. Results: The 99mTc balloon presented a weighted dose rate in the tumor bed of 0.428 cGy.h-1.mCi-1 and 0.190 cGyh-1.mCi-1 at the balloon surface and at 8-10 mm from the surface, respectively, compared with 0.499 and 0.150 cGyh-1.mCi-1, respectively, for the HDR 192Ir balloon. An exposure time of 24 hours was required for the 99mTc balloon to produce a boost of 10.14 Gy with 1.0 Ci, whereas only 24 minutes with 10.0 Ci segments were required for the HDR 192Ir balloon to produce a boost of 5.14 Gy at the same reference point, or 10.28 Gy in two 24-minutes fractions. Conclusion: Temporary 99mTc balloon implantation is an attractive option for adjuvant radiotherapy in breast cancer, because of its availability, economic viability, and similar dosimetry in comparison with the use of HDR 192Ir balloon implantation, which is the current standard in clinical practice.

  3. Dosimetric intercomparison of permanent Ho-166 seed's implants and HDR Ir-192 brachytherapy in breast cancer.

    Science.gov (United States)

    de Campos, Tarcisio Passos Ribeiro; Nogueira, Luciana Batista; Trindade, Bruno; Cuperschmid, Ethel Mizrahy

    2016-01-01

    To provide a comparative dosimetric analysis of permanent implants of Ho(166)-seeds and temporary HDR Ir(192)-brachytherapy through computational simulation. Brachytherapy with Ir(192)-HDR or LDR based on temporary wires or permanent radioactive seed implants can be used as dose reinforcement for breast radiation therapy. Permanent breast implants have not been a practical clinical routine; although, I(125) and Pd(103)-seeds have already been reported. Biodegradable Ho(166)-ceramic-seeds have been addressed recently. Simulations of implants of nine Ho(166)-seeds and equivalent with HDR Ir(192)-brachytherapy were elaborated in MCNP5, shaped in a computational multivoxel simulator which reproduced a female thorax phantom. Spatial dose rate distributions and dose-volume histograms were generated. Protocol's analysis involving exposure time, seed's activities and dose were performed. Permanent Ho(166)-seed implants presented a maximum dose rate per unit of contained activity (MDR) of 1.1601 μGy h(-1) Bq(-1); and, a normalized MDR in standard points (8 mm, equidistant to 03-seeds - SP1, 10 mm - SP2) of 1.0% (SP1) and 0.5% (SP2), respectively. Ir(192)-brachytherapy presented MDR of 4.3945 × 10(-3) μGy h(-1) Bq(-1); and, 30% (SP1), and 20% (SP2). Therefore, seed's implant activities of 333 MBq (Ho(166)) and 259 GBq (Ir(192)) produced prescribed doses of 58 Gy (SP1; 5d) and 56 Gy (SP1, 5 fractions, 6 min), respectively. Breast Ho(166)-implants of 37-111 MBq are attractive due to the high dose rate near 6-10 mm from seeds, equivalent to Ir(192)-brachytherapy of 259 GBq (3 fractions, 6 min) providing similar dose in standard points at a week; however, with spatial dose distribution better confined. The seed positioning can be adjusted for controlling the breast tumor, in stages I and II, in flat and deep tumors, without any breast volumetric limitation.

  4. Source position verification and dosimetry in HDR brachytherapy using an EPID

    International Nuclear Information System (INIS)

    Smith, R. L.; Taylor, M. L.; McDermott, L. N.; Franich, R. D.; Haworth, A.; Millar, J. L.

    2013-01-01

    Purpose: Accurate treatment delivery in high dose rate (HDR) brachytherapy requires correct source dwell positions and dwell times to be administered relative to each other and to the surrounding anatomy. Treatment delivery inaccuracies predominantly occur for two reasons: (i) anatomical movement or (ii) as a result of human errors that are usually related to incorrect implementation of the planned treatment. Electronic portal imaging devices (EPIDs) were originally developed for patient position verification in external beam radiotherapy and their application has been extended to provide dosimetric information. The authors have characterized the response of an EPID for use with an 192 Ir brachytherapy source to demonstrate its use as a verification device, providing both source position and dosimetric information.Methods: Characterization of the EPID response using an 192 Ir brachytherapy source included investigations of reproducibility, linearity with dose rate, photon energy dependence, and charge build-up effects associated with exposure time and image acquisition time. Source position resolution in three dimensions was determined. To illustrate treatment verification, a simple treatment plan was delivered to a phantom and the measured EPID dose distribution compared with the planned dose.Results: The mean absolute source position error in the plane parallel to the EPID, for dwells measured at 50, 100, and 150 mm source to detector distances (SDD), was determined to be 0.26 mm. The resolution of the z coordinate (perpendicular distance from detector plane) is SDD dependent with 95% confidence intervals of ±0.1, ±0.5, and ±2.0 mm at SDDs of 50, 100, and 150 mm, respectively. The response of the EPID is highly linear to dose rate. The EPID exhibits an over-response to low energy incident photons and this nonlinearity is incorporated into the dose calibration procedure. A distance (spectral) dependent dose rate calibration procedure has been developed. The

  5. Comparison of air-kerma strength determinations for HDR {sup 192}Ir sources

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, Brian E.; Davis, Stephen D.; Schmidt, Cal R.; Micka, John A.; DeWerd, Larry A. [Department of Medical Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

    2011-12-15

    Purpose: To perform a comparison of the interim air-kerma strength standard for high dose rate (HDR) {sup 192}Ir brachytherapy sources maintained by University of Wisconsin Accredited Dosimetry Calibration Laboratory (UWADCL) with measurements of the various source models using modified techniques from the literature. The current interim standard was established by Goetsch et al. in 1991 and has remained unchanged to date. Methods: The improved, laser-aligned seven-distance apparatus of University of Wisconsin Medical Radiation Research Center (UWMRRC) was used to perform air-kerma strength measurements of five different HDR {sup 192}Ir source models. The results of these measurements were compared with those from well chambers traceable to the original standard. Alternative methodologies for interpolating the {sup 192}Ir air-kerma calibration coefficient from the NIST air-kerma standards at {sup 137}Cs and 250 kVp x rays (M250) were investigated and intercompared. As part of the interpolation method comparison, the Monte Carlo code EGSnrc was used to calculate updated values of A{sub wall} for the Exradin A3 chamber used for air-kerma strength measurements. The effects of air attenuation and scatter, room scatter, as well as the solution method were investigated in detail. Results: The average measurements when using the inverse N{sub K} interpolation method for the Classic Nucletron, Nucletron microSelectron, VariSource VS2000, GammaMed Plus, and Flexisource were found to be 0.47%, -0.10%, -1.13%, -0.20%, and 0.89% different than the existing standard, respectively. A further investigation of the differences observed between the sources was performed using MCNP5 Monte Carlo simulations of each source model inside a full model of an HDR 1000 Plus well chamber. Conclusions: Although the differences between the source models were found to be statistically significant, the equally weighted average difference between the seven-distance measurements and the well

  6. Comparison of air-kerma strength determinations for HDR 192Ir sources

    International Nuclear Information System (INIS)

    Rasmussen, Brian E.; Davis, Stephen D.; Schmidt, Cal R.; Micka, John A.; DeWerd, Larry A.

    2011-01-01

    Purpose: To perform a comparison of the interim air-kerma strength standard for high dose rate (HDR) 192 Ir brachytherapy sources maintained by University of Wisconsin Accredited Dosimetry Calibration Laboratory (UWADCL) with measurements of the various source models using modified techniques from the literature. The current interim standard was established by Goetsch et al. in 1991 and has remained unchanged to date. Methods: The improved, laser-aligned seven-distance apparatus of University of Wisconsin Medical Radiation Research Center (UWMRRC) was used to perform air-kerma strength measurements of five different HDR 192 Ir source models. The results of these measurements were compared with those from well chambers traceable to the original standard. Alternative methodologies for interpolating the 192 Ir air-kerma calibration coefficient from the NIST air-kerma standards at 137 Cs and 250 kVp x rays (M250) were investigated and intercompared. As part of the interpolation method comparison, the Monte Carlo code EGSnrc was used to calculate updated values of A wall for the Exradin A3 chamber used for air-kerma strength measurements. The effects of air attenuation and scatter, room scatter, as well as the solution method were investigated in detail. Results: The average measurements when using the inverse N K interpolation method for the Classic Nucletron, Nucletron microSelectron, VariSource VS2000, GammaMed Plus, and Flexisource were found to be 0.47%, -0.10%, -1.13%, -0.20%, and 0.89% different than the existing standard, respectively. A further investigation of the differences observed between the sources was performed using MCNP5 Monte Carlo simulations of each source model inside a full model of an HDR 1000 Plus well chamber. Conclusions: Although the differences between the source models were found to be statistically significant, the equally weighted average difference between the seven-distance measurements and the well chambers was 0.01%, confirming that

  7. Comparison of air-kerma strength determinations for HDR (192)Ir sources.

    Science.gov (United States)

    Rasmussen, Brian E; Davis, Stephen D; Schmidt, Cal R; Micka, John A; Dewerd, Larry A

    2011-12-01

    To perform a comparison of the interim air-kerma strength standard for high dose rate (HDR) (192)Ir brachytherapy sources maintained by the University of Wisconsin Accredited Dosimetry Calibration Laboratory (UWADCL) with measurements of the various source models using modified techniques from the literature. The current interim standard was established by Goetsch et al. in 1991 and has remained unchanged to date. The improved, laser-aligned seven-distance apparatus of the University of Wisconsin Medical Radiation Research Center (UWMRRC) was used to perform air-kerma strength measurements of five different HDR (192)Ir source models. The results of these measurements were compared with those from well chambers traceable to the original standard. Alternative methodologies for interpolating the (192)Ir air-kerma calibration coefficient from the NIST air-kerma standards at (137)Cs and 250 kVp x rays (M250) were investigated and intercompared. As part of the interpolation method comparison, the Monte Carlo code EGSnrc was used to calculate updated values of A(wall) for the Exradin A3 chamber used for air-kerma strength measurements. The effects of air attenuation and scatter, room scatter, as well as the solution method were investigated in detail. The average measurements when using the inverse N(K) interpolation method for the Classic Nucletron, Nucletron microSelectron, VariSource VS2000, GammaMed Plus, and Flexisource were found to be 0.47%, -0.10%, -1.13%, -0.20%, and 0.89% different than the existing standard, respectively. A further investigation of the differences observed between the sources was performed using MCNP5 Monte Carlo simulations of each source model inside a full model of an HDR 1000 Plus well chamber. Although the differences between the source models were found to be statistically significant, the equally weighted average difference between the seven-distance measurements and the well chambers was 0.01%, confirming that it is not necessary to

  8. Nachhaltiger Lebensmittelkonsum gestern, heute und morgen

    DEFF Research Database (Denmark)

    Aschemann-Witzel, Jessica

    2013-01-01

    Die Weltgemeinschaft sieht sich mit steigendem Bevölkerungswachstum und Zielkonflikten der Nutzung von Land und Agrarrohstoffen konfrontiert. Dies wirft die Frage auf, wie nachhaltiger Lebensmittelkonsum in der Zukunft auszusehen hat. Der Beitrag diskutiert die Frage aus Sicht der Konsumverhaltens...

  9. Ruhende Flüssigkeiten und Gase

    Science.gov (United States)

    Heintze, Joachim

    Das mechanische Verhalten von Flüssigkeiten und Gasen ist dadurch gekennzeichnet, dass sie keine statische Schubfestigkeit besitzen, andernfalls würden sie nicht beginnen, zu fließen. In ruhenden Flüssigkeiten und Gasen können daher keine Schubspannungen bestehen:

  10. Handlung und Kommunikation als Grundbegriffe der Soziologie

    NARCIS (Netherlands)

    Martens, W.P.M.; Albert, H.; Greshoff, R.; Schützeichel, R.

    2010-01-01

    Handlung und Kommunikation gelten in der Soziologie manchmal als alternative, konkurrierende Grundbegriffe für die Beschreibung und Erklärung sozialer Zusammenhänge (siehe u.a. Luhmann 1984; 1990; Schneider 1994; Stichweh 2000; Greshoff 1999; Schwinn 2001; Albert et. al. 2003). Eine Soziologie,

  11. Die Gestalten und das Gestalten der Welt

    NARCIS (Netherlands)

    Ierna, Carlo; Höfer, Ulf; Valent, Juta

    2017-01-01

    In seiner Kosmogonie bespricht Ehrenfels den Ursprung, die Entwicklung, und das endgültige Schicksal des Universums: die Gestalt der Welt. Einerseits ist sie ein Kosmos, ein Geschöpf des Ordnungsprinzips, andererseits ein Chaos, als Resultat des Prinzips des Zufalls und der Entropie. Diese beiden

  12. Systeme im Einsatz. Lernmanagement, Kompetenzmanagement und PLE

    NARCIS (Netherlands)

    Kalz, Marco; Schön, Sandra; Lindner, Martin; Roth, Detlev; Baumgartner, Peter

    2011-01-01

    Kalz, M., Schön, S., Lindner, M., Roth, D., & Baumgartner, P. (2011). Systeme im Einsatz. Lernmanagement, Kompetenzmanagement und PLE. In M. Ebner, & S. Schön (Eds.), L3T - Lerhbuch für Lernen und Lehren mit Technologie (pp. 111-118). Graz, Austria: Uni Graz. Available at

  13. Schaulust und Horror Soziokulturelle - Perspektiven auf PEEPING TOM

    Directory of Open Access Journals (Sweden)

    Thomas Ballhausen

    2010-09-01

    Full Text Available Die Geschichte des Kinos und des Films ist mindestens ebenso sehr eine Geschichte des Schreckens (und der damit verbundenen Schaulust wie sie eine Geschichte des Dokumentarischen zu sein scheint. Es sind die außergewöhnlichen Körper und deren Bewegungen, die das Publikum zu allen Zeiten faszinierten, schockierten und zum Schauen und Sehen lockten. Besonders das Genre des Horrorfilms ist mit diesem zentralen Aspekt des Kinos besonders deutlich verbunden.

  14. Quantitative Analyse und Visualisierung der Herzfunktionen

    Science.gov (United States)

    Sauer, Anne; Schwarz, Tobias; Engel, Nicole; Seitel, Mathias; Kenngott, Hannes; Mohrhardt, Carsten; Loßnitzer, Dirk; Giannitsis, Evangelos; Katus, Hugo A.; Meinzer, Hans-Peter

    Die computergestützte bildbasierte Analyse der Herzfunktionen ist mittlerweile Standard in der Kardiologie. Die verfügbaren Produkte erfordern meist ein hohes Maß an Benutzerinteraktion und somit einen erhöhten Zeitaufwand. In dieser Arbeit wird ein Ansatz vorgestellt, der dem Kardiologen eine größtenteils automatische Analyse der Herzfunktionen mittels MRT-Bilddaten ermöglicht und damit Zeitersparnis schafft. Hierbei werden alle relevanten herzphysiologsichen Parameter berechnet und mithilfe von Diagrammen und Graphen visualisiert. Diese Berechnungen werden evaluiert, indem die ermittelten Werte mit manuell vermessenen verglichen werden. Der hierbei berechnete mittlere Fehler liegt mit 2,85 mm für die Wanddicke und 1,61 mm für die Wanddickenzunahme immer noch im Bereich einer Pixelgrösse der verwendeten Bilder.

  15. Sowjetunion und Völkerrecht 1962-1973 / Henn-Jüri Uibopuu

    Index Scriptorium Estoniae

    Uibopuu, Henn-Jüri, 1929-2012

    1980-01-01

    Tutvustus: Sowjetunion und Völkerrecht 1962-1973 : Bibliographie und analyse / hrsg. Boris Meissner, Dietrich Frenzke und Erika Chilicki. Köln : Wissenschaft und Politik, 1979 [t.p. incorrectly: 1977

  16. Bewegung bei Vorschulkindern: Empfehlungen und Wirklichkeit

    Directory of Open Access Journals (Sweden)

    Graf C

    2011-01-01

    Full Text Available Bewegung und körperliche Aktivität spielen insbesondere in der ganzheitlichen Entwicklung von Kindern eine wichtige Rolle. Heutzutage ist der kindliche Lebensstil allerdings von Bewegungsarmut und der Nutzung audiovisueller Medien geprägt. Bereits Kindergartenkinder sind überwiegend inaktiv bzw. verbringen viel Zeit mit Fernsehen. Eine mögliche Folge von mangelnder Bewegung können motorische Defizite darstellen. In eigenen Kollektiven schneiden mindestens 45 % der Kinder unterdurchschnittlich in den motorischen Hauptbeanspruchungsformen Koordination, Kraft und Schnelligkeit ab. Inwiefern sich dies langfristig auf die gesunde körperliche, aber auch geistige und emotionale Entwicklung der Kinder auswirkt, kann derzeit noch nicht beantwortet werden. Sicherlich unterstützen aber motorische Defizite ein Meidungsverhalten und den weiteren Rückzug aus der Bewegung sowie die Entwicklung von Übergewicht und Adipositas. Allgemein wird für Kinder in dieser Altersgruppe mindestens 2 Stunden tägliche Bewegungszeit sowie eine Reduktion der Fernsehzeit auf maximal 30 Min. empfohlen. Um diese Ziele zu erreichen bzw. zu unterstützen, sind effektive präventive Programme in den verschiedenen Lebensräumen der Kinder, Kindergärten, aber auch pädiatrischen Praxen etc. vonnöten. Bislang ist kein gesundheitsförderlicher/ präventiver „Königsweg“ bekannt, insbesondere nicht für Risikofamilien mit einem geringen sozioökonomischen Status und/oder Migrationshintergrund. Wichtig erscheinen aber die Förderung der intersektoralen Zusammenarbeit und ein Schwerpunkt in der Planung und Umsetzung auf Qualitätssicherung und Projektmanagement, um auch nachhaltig die Gesundheit der Kinder zu unterstützen.

  17. Experimental and theoretical investigations of soil-structure interaction effect at HDR-reactor-building

    International Nuclear Information System (INIS)

    Wassermann, K.

    1983-01-01

    Full-scale dynamic testing on intermediate and high levels was performed at the Heissdampfreaktor (HDR) in 1979. Various types of dynamic forces were applied and response of the reactor containment structure and internal components was measured. Precalculations of dynamic behaviour and response of the structure were made through different mathematical models for the structure and the underlying soil. Soil-Structure Interaction effects are investigated and different theoretical models are compared with experimental results. In each model, the soil is represented by springs attached to the structural model. Stiffnesses of springs are calculated by different finite-element idealizations and half-space approximations. Eigenfrequencies and damping values related to interaction effects (translation, rocking, torsion) are identified from test results. The comparisons of dynamic characteristic of the soil-structure system between precalculations and test results show good agreement in general. (orig.)

  18. SW England seismic monitoring for the HDR geothermal programme in Cornwall 1989 to September 1991

    International Nuclear Information System (INIS)

    Walker, A.B.

    1992-01-01

    The potential for earthquakes to be triggered by fluid injected into boreholes has been recognised for 25 years and natural earthquakes in Cornwall have been reported for over 250 years. As a result, the Geothermal Steering Committee advising the Hot Dry Rock project recommended that background seismic monitoring be undertaken around the HDR experimental site at Rosemanowes. A network of seismographs was established for this purpose by the British Geological Survey (BGS) in late 1980 and has been operated continuously through September 1991. The primary aim of the network has been to provide an independent, continuous assessment of all vibrational transients in order to discriminate between those caused by the Hot Dry Rock experiments and those of natural origin or from other man-made sources. In this respect, the work provides an insurance against claims that extraneous seismic activity is related to those experiments. (author)

  19. Structural safety of HDR reactor building during large scale vibration tests

    International Nuclear Information System (INIS)

    Stangenberg, F.; Zinn, R.

    1985-01-01

    In the second phase of the HDR investigations, a high shaker excitation of the building is planned using a large shaker which will be located on the operating floor and will be brought up to speed in a balanced condition and then unbalanced and decoupled from the drive system. With decreasing speed the shaker comes in resonance with the building frequencies and its energy is transferred to the building. In this paper the structural safety of the reactor building during the projected shaker tests is analysed. Dynamic response calculations with coupling between building and shaker by simultaneously integrating the equilibrium equations of both building and shaker are presented. The resulting building stresses, soil pressures etc. are compared with allowable values. (orig.)

  20. Comparison of leak opening and leak rate calculations to HDR experimental results

    International Nuclear Information System (INIS)

    Grebner, H.; Hoefler, A.; Hunger, H.

    1993-01-01

    During the last years a number of calculations of leak opening and leak rate for through cracks in piping components have been performed. Analyses are pre- or mostly post-calculations to experiments performed at the HDR facility under PWR operating conditions. Piping components under consideration were small diameter straight pipes with circumferential cracks, pipe bends with longitudinal or circumferential cracks and pipe branches with weldment cracks. The components were loaded by internal pressure and opening as well as closing bending moment. The finite element method and two-phase flow leak rate programs were used for the calculations. Results of the analyses are presented as J-integral values, crack opening displacements and areas and leak rates as well as comparisons to the experimental results

  1. Accurate assessment of the distortions produced by the transit dose in HDR brachytherapy

    International Nuclear Information System (INIS)

    Nani, E.K.; Kyere, A.W.K.; Tetteh, K.

    2001-01-01

    Current polynomial methods used in the modelling of the dose distributions in HDR brachytherapy have been reformulated to improve accuracy. An example is provided to show the effects of the transit dose on the output. The transit dose, which is neglected by current computer software for calculating doses, can result in significant dosimetric errors. These additional unrecognised doses imply over-dosing and distortions in the dose distributions within the irradiated volume. Assessment of dose to critical and radiosensitive organs is therefore inaccurate. These could increase late tissue complications as predicted by the Linear Quadratic Model. Our model works very well for straight catheters and is highly recommended for the evaluation of the transit dose around such catheters. (author)

  2. Heissdampfreaktor (HDR) steel-containment-vessel and floodwater-storage-tank structural-dynamics tests

    International Nuclear Information System (INIS)

    Arendts, J.G.

    1982-01-01

    Inertance (vibration) testing of two significant vessels at the Heissdampfreaktor (HDR) facility, located near Kahl, West Germany, was recently completed. Transfer functions were obtained for determination of the modal properties (frequencies, mode shapes and damping) of the vessels using two different test methods for comparative purposes. One of the vessels tested was the steel containment vessel (SCV). The SCV is approximately 180 feet high and 65 feet in diameter with a 1.2-inch wall thickness. The other vessel, called the floodwater storage tank (FWST), is a vertically standing vessel approximately 40 feet high and 10 feet in diameter with a 1/2-inch wall thickness. The FWST support skirt is square (in plan views) with its corners intersecting the ellipsoidal bottom head near the knuckle region

  3. Video Enhancement and Dynamic Range Control of HDR Sequences for Automotive Applications

    Directory of Open Access Journals (Sweden)

    Giovanni Ramponi

    2007-01-01

    Full Text Available CMOS video cameras with high dynamic range (HDR output are particularly suitable for driving assistance applications, where lighting conditions can strongly vary, going from direct sunlight to dark areas in tunnels. However, common visualization devices can only handle a low dynamic range, and thus a dynamic range reduction is needed. Many algorithms have been proposed in the literature to reduce the dynamic range of still pictures. Anyway, extending the available methods to video is not straightforward, due to the peculiar nature of video data. We propose an algorithm for both reducing the dynamic range of video sequences and enhancing its appearance, thus improving visual quality and reducing temporal artifacts. We also provide an optimized version of our algorithm for a viable hardware implementation on an FPGA. The feasibility of this implementation is demonstrated by means of a case study.

  4. Computed versus measured response of HDR reactor building in large scale shaking tests

    International Nuclear Information System (INIS)

    Werkle, H.; Waas, G.

    1987-01-01

    The earthquake resistant design of NPP structures and their installations is commonly based on linear analysis methods. Nonlinear effects, which may occur during strong earthquakes, are approximately accounted for in the analysis by adjusting the structural damping values. Experimental investigations of nonlinear effects were performed with an extremely heavy shaker at the decommissioned HDR reactor building in West Germany. The tests were directed by KfK (Nuclear Research Center Karlsruhe, West Germany) and supported by several companies and institutes from West Germany, Switzerland and the USA. The objective was the dynamic repsonse behaviour of the structure, piping and components to strong earthquake-like shaking including nonlinear effects. This paper presents some results of safety analyses and measurements, which were performed prior and during the test series. It was intended to shake the building up to a level where only a marginal safety against global structural failure was left

  5. HDR Brachytherapy in the Management of High-Risk Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Susan Masson

    2012-01-01

    Full Text Available High-dose-rate (HDR brachytherapy is used with increasing frequency for the treatment of prostate cancer. It is a technique which allows delivery of large individual fractions to the prostate without exposing adjacent normal tissues to unacceptable toxicity. This approach is particularly favourable in prostate cancer where tumours are highly sensitive to dose escalation and to increases in radiotherapy fraction size, due to the unique radiobiological behaviour of prostate cancers in contrast with other malignancies. In this paper we discuss the rationale and the increasing body of clinical evidence for the use of this technique in patients with high-risk prostate cancer, where it is combined with external beam radiotherapy. We highlight practical aspects of delivering treatment and discuss toxicity and limitations, with particular reference to current practice in the United Kingdom.

  6. Der Einfluss von sozialer Ungleichheit und kulturellen Unterschieden auf die Wahrnehmung von finanziellen und Arbeitsplatzrisiken: Überlegungen zur Risikogesellschaft

    OpenAIRE

    Abbott, David; Quilgars, Deborah; Jones, Anwen

    2006-01-01

    Der vorliegende Artikel beruht auf Daten einer Studie, die sich mit der Frage beschäftigt, wie verschiedene soziale und kulturelle Gruppen die Risiken von Einkommens- und Arbeitsplatzverlust wahrnehmen und darauf reagieren. Autoren wie LASH, DOUGLAS und LUPTON betonten die Bedeutung von Gruppenzugehörigkeit und sozialen Kategorien für die Strukturierung der Reaktionsweisen auf verschiedene Risikoarten. Sie sprechen daher lieber von Risikokulturen als von der Risikogesellschaft. Trotzdem erken...

  7. Dosimetric comparison between the microSelectron HDR 192Ir v2 source and the BEBIG 60Co source for HDR brachytherapy using the EGSnrc Monte Carlo transport code

    International Nuclear Information System (INIS)

    Anwarul Islam, M.; Akramuzzaman, M.M.; Zakaria, G.A.

    2012-01-01

    Manufacturing of miniaturized high activity 192 Ir sources have been made a market preference in modern brachytherapy. The smaller dimensions of the sources are flexible for smaller diameter of the applicators and it is also suitable for interstitial implants. Presently, miniaturized 60 Co HDR sources have been made available with identical dimensions to those of 192 Ir sources. 60 Co sources have an advantage of longer half life while comparing with 192 Ir source. High dose rate brachytherapy sources with longer half life are logically pragmatic solution for developing country in economic point of view. This study is aimed to compare the TG-43U1 dosimetric parameters for new BEBIG 60 Co HDR and new microSelectron 192 Ir HDR sources. Dosimetric parameters are calculated using EGSnrc-based Monte Carlo simulation code accordance with the AAPM TG-43 formalism for microSelectron HDR 192 Ir v2 and new BEBIG 60 Co HDR sources. Air-kerma strength per unit source activity, calculated in dry air are 9.698x10 -8 ± 0.55% U Bq -1 and 3.039x10 -7 ± 0.41% U Bq -1 for the above mentioned two sources, respectively. The calculated dose rate constants per unit air-kerma strength in water medium are 1.116±0.12% cGy h -1 U -1 and 1.097±0.12% cGy h -1 U -1 , respectively, for the two sources. The values of radial dose function for distances up to 1 cm and more than 22 cm for BEBIG 60 Co HDR source are higher than that of other source. The anisotropic values are sharply increased to the longitudinal sides of the BEBIG 60 Co source and the rise is comparatively sharper than that of the other source. Tissue dependence of the absorbed dose has been investigated with vacuum phantom for breast, compact bone, blood, lung, thyroid, soft tissue, testis, and muscle. No significant variation is noted at 5 cm of radial distance in this regard while comparing the two sources except for lung tissues. The true dose rates are calculated with considering photon as well as electron transport using

  8. Preliminary results of intersticial HDR brachytherapy in association with conservative surgery for soft tissue sarcomas

    International Nuclear Information System (INIS)

    Pellizzon, A.C.A; Ferrigno, R.; Trippe, N.; Novaes, P.; Salvajoli, J.V.; Fogareli, R.; Maja, M.A.C.; Baraldi, H.

    1996-01-01

    From january 1994 to january 1995 seven patients were treated with conservative surgery in association to postoperative HDR brachytherapy through Micro-Selectron HDR. Four patients were male and three female, the ages ranged from 20 to 60 years old and the main site of the tumor were at the extremities and just one had a perineal lesion. The follow up ranged from 4 to 24 months. Most of the implants were done through single plane technic. Definition of the treatment volume was based on CT scans and metallic clips inserted during the surgery. The prescribed dose was at 10mm from the implant plane. The patient with perineal lesion had a volumetric implant and the dose prescription was based on Paris System, in which the total volume of the tumor bed must be included in a 85% isodose curve. The number of catheters used ranged from 6 to 14 and the active length from 20 to 150mm, placed intraoperatively. The volumetric implant was performed through perineal template to guide the needles in number of nine and an active length of 60mm. The prescribed dose ranged from 20 to 25Gy when associated with EBRT and 30 to 35Gy when brachytherapy alone was used. Results: All patients had local control. Acute complications were observed only in the skin, limited to mild erytema and dry descanation. Conclusions: Although the number of the patients is small, this procedure has been shown to be effective in local control when associated to conservative surgery, can be easily and safely done and gives the possibilities of dose optimization

  9. SU-F-T-11: Scintillator Based Quality Assurance Device for HDR Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Jozsef, G [New York University Medical Center, New York, NY (United States)

    2016-06-15

    Purpose: To build a test device for HDR afterloaders capable of checking source positions, times at positions and estimate the activity of the source. Methods: A catheter is taped on a plastic scintillation sheet. When a source travels through the catheter, the scintillator sheet lights up around the source. The sheet is monitored with a video camera, and records the movement of the light spot. The center of the spot on each image on the video provides the source location, and the time stamps of the images can provide the dwell time the source spend in each location. Finally, the brightness of the light spot is related to the activity of the source. A code was developed for noise removal, calibrate the scale of the image to centimeters, eliminate the distortion caused by the oblique view angle, identifying the boundaries of the light spot, transforming the image into binary and detect and calculate the source motion, positions and times. The images are much less noisy if the camera is shielded. That requires that the light spot is monitored in a mirror, rather than directly. The whole assembly is covered from external light and has a size of approximately 17×35×25cm (H×L×W) Results: A cheap camera in BW mode proved to be sufficient with a plastic scintillator sheet. The best images were resulted by a 3mm thick sheet with ZnS:Ag surface coating. The shielding of the camera decreased the noise, but could not eliminate it. A test run even in noisy condition resulted in approximately 1 mm and 1 sec difference from the planned positions and dwell times. Activity tests are in progress. Conclusion: The proposed method is feasible. It might simplify the monthly QA process of HDR Brachytherapy units.

  10. Dosimetric analysis at ICRU reference points in HDR-brachytherapy of cervical carcinoma.

    Science.gov (United States)

    Eich, H T; Haverkamp, U; Micke, O; Prott, F J; Müller, R P

    2000-01-01

    In vivo dosimetry in bladder and rectum as well as determining doses on suggested reference points following the ICRU report 38 contribute to quality assurance in HDR-brachytherapy of cervical carcinoma, especially to minimize side effects. In order to gain information regarding the radiation exposure at ICRU reference points in rectum, bladder, ureter and regional lymph nodes those were calculated (digitalisation) by means of orthogonal radiographs of 11 applications in patients with cervical carcinoma, who received primary radiotherapy. In addition, the doses at the ICRU rectum reference point was compared to the results of in vivo measurements in the rectum. The in vivo measurements were by factor 1.5 below the doses determined for the ICRU rectum reference point (4.05 +/- 0.68 Gy versus 6.11 +/- 1.63 Gy). Reasons for this were: calibration errors, non-orthogonal radiographs, movement of applicator and probe in the time span between X-ray and application, missing connection of probe and anterior rectal wall. The standard deviation of calculations at ICRU reference points was on average +/- 30%. Possible reasons for the relatively large standard deviation were difficulties in defining the points, identifying them on radiographs and the different locations of the applicators. Although 3 D CT, US or MR based treatment planning using dose volume histogram analysis is more and more established, this simple procedure of marking and digitising the ICRU reference points lengthened treatment planning only by 5 to 10 minutes. The advantages of in vivo dosimetry are easy practicability and the possibility to determine rectum doses during radiation. The advantages of computer-aided planning at ICRU reference points are that calculations are available before radiation and that they can still be taken into account for treatment planning. Both methods should be applied in HDR-brachytherapy of cervical carcinoma.

  11. Exclusive radiation therapy of endometrial carcinoma using HDR Co-60 and Cf-252 sources

    International Nuclear Information System (INIS)

    Inciura, A.; Janulionis, E.; Atkocius, V.

    2000-01-01

    Although the main treatment of endometrial cancer is surgery, the gross spread of carcinoma in pelvis, elderly age of the patients and serious therapeutical diseases do not allow to operate 20% of the patients. For these patients only radical treatment decision is the combined radiation therapy. However, using various modalities of combined radiotherapy, the treatment results are not satisfying: only 52% of patients survive 5 years. There was implemented a new method of combined radiotherapy, using a three-channel applicator with two-positional locating of HDR Co-60 radioactive sources (group I). A new method of brachytherapy for endometrial carcinoma using a HDR Cf 252 sources (group II) was implemented too. For group I the medium total dose of the point A was 77.6 Gy, point I - 69.6 Gy. point 2 - 84.2 Gy, point B - 52.6 Gy, For group II the medium total dose the points A, 3 and 4 was 50 iGy. For group I 1 year overaII survival rate was 85%, 3 year - 73%. The 3 year survival rate for stage I was 79%, for stage II - 89%, for stage III - 33%. 3 year survival for highly virulent tumours - 56% and for low virulent (adenocarcinoma) - 82% was statistically different. The loss of tumour differentiation correlated with the worse prognosis: 3 year survival for G1 and G2 tumours was 92%, for G3 - 45%. Low hemoglobin level was also associated with low survival rate: 2 year survival for Hb≥120g/l was 85% and Hb<120g/l - 23%. 1 year survival rate was 87%, 3 year - 66%, 5 year - 58% for group II, treated with Cf-252. Radiation complications occurred for 13.8% of the patients for group I and 6.2% for group II. Good survival rates and a small number of complications sufficiently proofed treatment method. (author)

  12. Ir-192 HDR transit dose and radial dose function determination using alanine/EPR dosimetry

    International Nuclear Information System (INIS)

    Calcina, Carmen S Guzman; Almeida, Adelaide de; Rocha, Jose R Oliveira; Abrego, Felipe Chen; Baffa, Oswaldo

    2005-01-01

    Source positioning close to the tumour in high dose rate (HDR) brachytherapy is not instantaneous. An increment of dose will be delivered during the movement of the source in the trajectory to its static position. This increment is the transit dose, often not taken into account in brachytherapeutic treatment planning. The transit dose depends on the prescribed dose, number of treatment fractions, velocity and activity of the source. Combining all these factors, the transit dose can be 5% higher than the prescribed absorbed dose value (Sang-Hyun and Muller-Runkel, 1994 Phys. Med. Biol. 39 1181-8, Nath et al 1995 Med. Phys. 22 209-34). However, it cannot exceed this percentage (Nath et al 1995). In this work, we use the alanine-EPR (electron paramagnetic resonance) dosimetric system using analysis of the first derivative of the signal. The transit dose was evaluated for an HDR system and is consistent with that already presented for TLD dosimeters (Bastin et al 1993 Int. J. Radiat. Oncol. Biol. Phys. 26 695-702). Also using the same dosimetric system, the radial dose function, used to evaluate the geometric dose degradation around the source, was determined and its behaviour agrees better with those obtained by Monte Carlo simulations (Nath et al 1995, Williamson and Nath 1991 Med. Phys. 18 434-48, Ballester et al 1997 Med. Phys. 24 1221-8, Ballester et al 2001 Phys. Med. Biol. 46 N79-90) than with TLD measurements (Nath et al 1990 Med. Phys. 17 1032-40)

  13. Poster - Thur Eve - 03: LDR to HDR: RADPOS applications in brachytherapy.

    Science.gov (United States)

    Cherpak, A J; Cygler, J E; Kertzscher, G; E, C; Perry, G

    2012-07-01

    The RADPOS in vivo dosimetry system combines an electromagnetic positioning sensor and either one or five MOSFET dosimeters. The feasibility of using the system for quality control has been explored for a range of radiotherapy treatment techniques including most recently transperineal interstitial permanent prostate brachytherapy and high dose rate (HDR) treatments. Dose and position information was collected by a RADPOS array detector inside a Foley catheter within patients' urethra during permanent seed implantation. Ten patients were studied, and average displacement during implantation was Δr = (1.4-5.1) mm, with movements up to 9.7 mm due to the removal of the transrectal ultrasound probe. Maximum integral dose in the prostatic urethra ranged from 110-195 Gy, and it was found that the dose can change up to 63 cGy (62.0%) depending on whether the rectal probe is in place. For HDR, a RADPOS detector was first calibrated with an Ir-192 source. A treatment was then simulated using a total of 50 dwell positions in 5 catheters in an acrylic phantom. Dwell positions ranged from 1 to 10 cm away from the RADPOS detector and dose was measured for each source position. An average calibration coefficient of 0.74±0.11 cGy/mV was calculated for the detector and the average absolute difference between measured values and expected dose was 0.7±5.4 cGy (5±20%). The demonstrated accuracy of RADPOS dose measurements along with its ability to simultaneously measure displacement makes it a powerful tool for brachytherapy treatments, where high dose gradients can present unique in vivo dosimetry challenges. © 2012 American Association of Physicists in Medicine.

  14. Dwell time modulation restrictions do not necessarily improve treatment plan quality for prostate HDR brachytherapy

    International Nuclear Information System (INIS)

    Balvert, Marleen; Gorissen, Bram L; Den Hertog, Dick; Hoffmann, Aswin L

    2015-01-01

    Inverse planning algorithms for dwell time optimisation in interstitial high-dose-rate (HDR) brachytherapy may produce solutions with large dwell time variations within catheters, which may result in undesirable selective high-dose subvolumes. Extending the dwell time optimisation model with a dwell time modulation restriction (DTMR) that limits dwell time differences between neighboring dwell positions has been suggested to eliminate this problem. DTMRs may additionally reduce the sensitivity for uncertainties in dwell positions that inevitably result from catheter reconstruction errors and afterloader source positioning inaccuracies. This study quantifies the reduction of high-dose subvolumes and the robustness against these uncertainties by applying a DTMR to template-based prostate HDR brachytherapy implants. Three different DTMRs were consecutively applied to a linear dose-based penalty model (LD) and a dose-volume based model (LDV), both obtained from literature. The models were solved with DTMR levels ranging from no restriction to uniform dwell times within catheters in discrete steps. Uncertainties were simulated on clinical cases using in-house developed software, and dose-volume metrics were calculated in each simulation. For the assessment of high-dose subvolumes, the dose homogeneity index (DHI) and the contiguous dose volume histogram were analysed. Robustness was measured by the improvement of the lowest D 90% of the planning target volume (PTV) observed in the simulations. For (LD), a DTMR yields an increase in DHI of approximately 30% and reduces the size of the largest high-dose volume by 2–5 cc. However, this comes at a cost of a reduction in D 90% of the PTV of 10%, which often implies that it drops below the desired minimum of 100%. For (LDV), none of the DTMRs were able to improve high-dose volume measures. DTMRs were not capable of improving robustness of PTV D 90% against uncertainty in dwell positions for both models. (paper)

  15. An automated optimization tool for high-dose-rate (HDR) prostate brachytherapy with divergent needle pattern

    Science.gov (United States)

    Borot de Battisti, M.; Maenhout, M.; de Senneville, B. Denis; Hautvast, G.; Binnekamp, D.; Lagendijk, J. J. W.; van Vulpen, M.; Moerland, M. A.

    2015-10-01

    Focal high-dose-rate (HDR) for prostate cancer has gained increasing interest as an alternative to whole gland therapy as it may contribute to the reduction of treatment related toxicity. For focal treatment, optimal needle guidance and placement is warranted. This can be achieved under MR guidance. However, MR-guided needle placement is currently not possible due to space restrictions in the closed MR bore. To overcome this problem, a MR-compatible, single-divergent needle-implant robotic device is under development at the University Medical Centre, Utrecht: placed between the legs of the patient inside the MR bore, this robot will tap the needle in a divergent pattern from a single rotation point into the tissue. This rotation point is just beneath the perineal skin to have access to the focal prostate tumor lesion. Currently, there is no treatment planning system commercially available which allows optimization of the dose distribution with such needle arrangement. The aim of this work is to develop an automatic inverse dose planning optimization tool for focal HDR prostate brachytherapy with needle insertions in a divergent configuration. A complete optimizer workflow is proposed which includes the determination of (1) the position of the center of rotation, (2) the needle angulations and (3) the dwell times. Unlike most currently used optimizers, no prior selection or adjustment of input parameters such as minimum or maximum dose or weight coefficients for treatment region and organs at risk is required. To test this optimizer, a planning study was performed on ten patients (treatment volumes ranged from 8.5 cm3to 23.3 cm3) by using 2-14 needle insertions. The total computation time of the optimizer workflow was below 20 min and a clinically acceptable plan was reached on average using only four needle insertions.

  16. TU-D-201-06: HDR Plan Prechecks Using Eclipse Scripting API

    Energy Technology Data Exchange (ETDEWEB)

    Palaniswaamy, G; Morrow, A; Kim, S; Rangaraj, D [Baylor Scott & White Health, Temple, TX (United States)

    2016-06-15

    Purpose: Automate brachytherapy treatment plan quality check using Eclipse v13.6 scripting API based on pre-configured rules to minimize human error and maximize efficiency. Methods: The HDR Precheck system is developed based on a rules-driven approach using Eclipse scripting API. This system checks for critical plan parameters like channel length, first source position, source step size and channel mapping. The planned treatment time is verified independently based on analytical methods. For interstitial or SAVI APBI treatment plans, a Patterson-Parker system calculation is performed to verify the planned treatment time. For endobronchial treatments, an analytical formula from TG-59 is used. Acceptable tolerances were defined based on clinical experiences in our department. The system was designed to show PASS/FAIL status levels. Additional information, if necessary, is indicated appropriately in a separate comments field in the user interface. Results: The HDR Precheck system has been developed and tested to verify the treatment plan parameters that are routinely checked by the clinical physicist. The report also serves as a reminder or checklist for the planner to perform any additional critical checks such as applicator digitization or scenarios where the channel mapping was intentionally changed. It is expected to reduce the current manual plan check time from 15 minutes to <1 minute. Conclusion: Automating brachytherapy plan prechecks significantly reduces treatment plan precheck time and reduces human errors. When fully developed, this system will be able to perform TG-43 based second check of the treatment planning system’s dose calculation using random points in the target and critical structures. A histogram will be generated along with tabulated mean and standard deviation values for each structure. A knowledge database will also be developed for Brachyvision plans which will then be used for knowledge-based plan quality checks to further reduce

  17. Ein überfälliger Dialog. Wie Frauen- und Geschlechterforschung und Soziologie miteinander ins Gespräch kommen können

    Directory of Open Access Journals (Sweden)

    Heike Kahlert

    2007-03-01

    Full Text Available Die Monographie von Brigitte Aulenbacher zum Zusammenhang von Rationalisierung, Geschlecht und Gesellschaft ist in gegenstandsbezogener und methodologischer Hinsicht ambitioniert, überzeugend und lesenswert. Die Studie stellt eine solide, manchmal auch etwas zu weitschweifige und detailreiche Grundlage für weiterführende Diskussionen zwischen der (sozialwissenschaftlichen Frauen- und Geschlechterforschung und der Soziologie, genauer der Gesellschaftstheorie in zeitdiagnostischer Perspektive, Arbeits-, Industrie-, Organisations- und Techniksoziologie, dar.

  18. Virtual HDR CyberKnife SBRT for Localized Prostatic Carcinoma: 5-year Disease-free Survival and Toxicity Observations

    Directory of Open Access Journals (Sweden)

    Donald Blake Fuller

    2014-11-01

    Full Text Available PURPOSEProstate stereotactic body radiotherapy (SBRT may substantially recapitulate the dose distribution of high-dose-rate (HDR brachytherapy, representing an externally delivered Virtual HDR treatment method. Herein we present 5-year outcomes from a cohort of consecutively treated Virtual HDR SBRT prostate cancer patients.METHODSSeventy-nine patients were treated from 2006 - 2009, 40 low-risk and 39 intermediate-risk, under IRB-approved clinical trial, to 38 Gy in 4 fractions. The planning target volume (PTV included prostate plus a 2-mm volume expansion in all directions, with selective use of a 5-mm prostate-to-PTV expansion and proximal seminal vesicle coverage in intermediate-risk patients, to better cover potential extraprostatic disease; rectal PTV margin reduced to zero in all cases. The prescription dose covered > 95% of the PTV (V100 >= 95%, with a minimum 150% PTV dose escalation to create HDR-like PTV dose distribution.RESULTSMedian pre-SBRT PSA level of 5.6 ng/mL decreased to 0.05 ng/mL 5 years out and 0.02 ng/mL 6 years out. At least one PSA bounce was seen in 55 patients (70% but only 3 of them subsequently relapsed, Biochemical-relapse-free survival was 100% and 92% for low-risk and intermediate-risk patients, respectively, by ASTRO definition (98% and 92% by Phoenix definition. Local relapse did not occur, distant metastasis-free survival was 100% and 95% by risk-group, and disease-specific survival was 100%. Acute and late grade 2 GU toxicity incidence was 10% and 9%, respectively; with 6% late grade 3 GU toxicity. Acute urinary retention did not occur. Acute and late grade 2 GI toxicity was 0% and 1%, respectively, with no grade 3 or higher toxicity. Of patients potent pre-SBRT, 65% remained so at 5 years.CONCLUSIONSVirtual HDR prostate SBRT creates a very low PSA nadir, a high rate of 5-year disease-free survival and an acceptable toxicity incidence, with results closely resembling those reported post-HDR brachytherapy.

  19. Bakteriochlorophyllvorstufen und Pigment-Protein-Komplexe in Rhodospirillum rubrum ST3 und GN11

    OpenAIRE

    Hammel, Jörg U.

    2006-01-01

    In der vorliegenden Arbeit wurden zwei Mutanten des Alpha-Proteobakteriums Rhodospirillum rubrum untersucht, die im Bakteriochlorophyll-Biosyntheseweg unterbrochen sind, um einen Beitrag zum genaueren Verständnis der Biosynthese dieser Moleküle und der einzelnen daran beteiligten Schritte zu liefern. Von den beiden Stämmen ST3 und GN11 wurden die ins Kulturmedium ausgeschiedenen Pigmente aufgereinigt und spektroskopisch analysiert. Ebenfalls wurden sowohl von ST3, als auch von GN11 die in int...

  20. Computerspielgewalt und Aggression: Längsschnittliche Untersuchung von Selektions- und Wirkungseffekten

    OpenAIRE

    Staude-Müller, Frithjof

    2011-01-01

    Auf Grundlage sozialkognitiver Aggressionsmodelle wurde die Beziehung zwischen Computerspielgewohnheiten und der Aggressionsneigung sowie Verzerrungen in der sozialen Informationsverarbeitung untersucht. Dazu wurden 499 Schüler/innen weiterführender Schulen (6.-8. Kl. Gymnasium, Haupt- und Realschule) in zwei Erhebungen mit einem Intervall von einem Jahr befragt. Mit hierarchischen Regressionsanalysen wurden Wirkungs- und Selektionseffekte geprüft, wobei relevante Drittvariablen (Monitoring u...

  1. Zu den Grundlagen der visuellen Soziologie: Wahrnehmen und Sehen, Beobachten und Betrachten

    OpenAIRE

    Bachleitner, Reinhard; Weichbold, Martin

    2015-01-01

    In diesem Beitrag werden die visuellen Modi des Wahrnehmens – das Sehen, Beobachten und Betrachten – in ihrem Wesen skizziert, und die doppelte Theorieabhängigkeit von Wahrnehmungsprozessen wird thematisiert. Dabei zeigt sich, dass mehrere offene methodologische und erkenntnistheoretische Fragen durch die Differenzierung des Wahrnehmungsvorgangs in drei Stufen (reines Sehen, kognitive Repräsentation, Transformation des Perzepts in Worte) sowie die Differenzierung der Wahrnehmungsmodi in jewei...

  2. Intermediale Synchronisation zwischen Volltext und Film und ihre Realisierung in Hybrideditionen

    OpenAIRE

    Bülow, Gilles

    2017-01-01

    Diese Arbeit behandelt die theoretische Erfassung und prototypische Erzeugung komplexer Musterdokumente mit synchronisiertem »Volltext« und »Bewegtbild«. Dabei werden wesentliche Randbedingungen für die Dokumentengliederung ermittelt. Diese Randbedingungen erlauben es dann, unterhalb der Plattformebene (des »reinen« Buchs und des »reinen« Films) neue multimediale Hybrideditionen auf Basis elektronischer Publikationsformate als Ausgabeplattform »sinnvoll« zu generieren. Empirisch wird der F...

  3. Additional androgen deprivation makes the difference. Biochemical recurrence-free survival in prostate cancer patients after HDR brachytherapy and external beam radiotherapy

    International Nuclear Information System (INIS)

    Schiffmann, Jonas; Tennstedt, Pierre; Beyer, Burkhard; Boehm, Katharina; Tilki, Derya; Salomon, Georg; Graefen, Markus; Lesmana, Hans; Platz, Volker; Petersen, Cordula; Kruell, Andreas; Schwarz, Rudolf

    2015-01-01

    The role of additional androgen deprivation therapy (ADT) in prostate cancer (PCa) patients treated with combined HDR brachytherapy (HDR-BT) and external beam radiotherapy (EBRT) is still unknown. Consecutive PCa patients classified as D'Amico intermediate and high-risk who underwent HDR-BT and EBRT treatment ± ADT at our institution between January 1999 and February 2009 were assessed. Multivariable Cox regression models predicting biochemical recurrence (BCR) were performed. BCR-free survival was assessed with Kaplan-Meier analyses. Overall, 392 patients were assessable. Of these, 221 (56.4 %) underwent trimodality (HDR-BT and EBRT and ADT) and 171 (43.6 %) bimodality (HDR-BT and EBRT) treatment. Additional ADT administration reduced the risk of BCR (HR: 0.4, 95 % CI: 0.3-0.7, p < 0.001). D'Amico high-risk patients had superior BCR-free survival when additional ADT was administered (log-rank p < 0.001). No significant difference for BCR-free survival was recorded when additional ADT was administered to D'Amico intermediate-risk patients (log-rank p = 0.2). Additional ADT administration improves biochemical control in D'Amico high-risk patients when HDR-BT and EBRT are combined. Physicians should consider the oncological benefit of ADT administration for these patients during the decision-making process. (orig.) [de

  4. Die Kunst des Intavolierens: Gebundenheit und Freiheit

    Directory of Open Access Journals (Sweden)

    Ring, Johannes

    2003-12-01

    Full Text Available A big part of 16th century keyboard repertory was intabulated vocal music; arrangements of motets, sets of masses and chansons. Marcant and sometimes little known examples show the different functions of intabulations: repertoire for the organists (liturgical function, music of delight and pedagogical functions. As a part of Ars Organistum intabulations were the basis of professional musical studies, learning to improvise organ music and to compose music. Masters like H. Scheidemann, the both Gabrielis, J. de Lublin, P. Philips, the both Cabezóns, some English and French anonym composers demonstrate that intabulations are much more than keyboard reductions - artful arrangements with their own life and character on the way to artful paraphrases. The intentions of the composers / arrangers in connection with the possibilities of the keyboard instruments definite the character and the step of transforming a vocal set in a (new piece of keyboard music.

    [de] Ein großer Teil des Musikrepertoires für Tasteninstrumente im 16. Jahrhundert bestand aus intavolierter Vokalmusik - Bearbeitungen von Motetten, Messsätzen und Chansons. Markante und teilweise wenig bekannte Beispiele zeigen verschiedene Funktionen der Intavolierungen. Zu nennen sind das Organistenrepertoire (liturgisches Umfeld, die Musik zur Erbauung und Unterhaltung und die pädagogische Funktion. Als Bestandteil der Ars Organistum waren Intavolierungen wichtig um professionell das Improvisieren von Musik und das Komponieren zu erlernen. Exemplarisch dokumentieren besonders H. Scheidemann, die beiden Gabrielis, J. de Lublin, P. Philips, die beiden Cabezóns und einige anonyme Komponisten aus England und Frankreich, dass ihre Kunst des Intavolierens weit über den Übertragungsmodus hinausgeht, bis hin zum virtuosen Arrangement und zur kunstvollen Paraphrase. Die Intentionen der Komponisten in Verbindung mit den Möglichkeiten der Tasteninstrumente pr

  5. Kommunikation und Lernen in partizipativen kulturellen und medialen Räumen

    Directory of Open Access Journals (Sweden)

    Elke Zobl

    2012-12-01

    Full Text Available Eine der interessantesten Transformationen in der Jugendkultur seit den 1990er-Jahren ist die steigende Zahl vor allem an Mädchen und jungen Frauen, die zu aktiven kulturellen Produzentinnen wurden. In diesem Artikel wird argumentiert, dass sie mit ihren eigenen kulturellen Produktionen und Netzwerken neue soziale und mediale Räume öffnen, die durch eine partizipative Kultur, selbst-organisiertes Lernen in informellen Kontexten und lokale, transnationale und virtuelle Vernetzung und Kommunikation geprägt sind. Ziel dieses Artikels ist es, das Kommunizieren und Lernen in partizipativen kulturellen (bzw. sozialen und medialen Räumen am Beispiel queer-feministischer Festivals – sogenannter „Ladyfeste“ – darzustellen und ihre Bedeutung in (medien-pädagogischen Kontexten zu diskutieren.One of the most interesting transformations in youth culture since the 1990s is the growing number of girls and young women as active cultural producers. By creating their own cultural productions and networks, this article argues, that they open up new cultural (i. e. social and media spaces which are characterized by a participatory culture, self-organised learning and local, transnational and virtual networks and communication. Taking the example of queer-feminist festivals (so called “Ladyfests”, the aim of this article is to discuss communication and learning in participatory cultural and media spaces and their meaning in the context of (media-pedagogy.

  6. PHP und MySQL der Web-Baukasten fur Einsteiger und Individualisten

    CERN Document Server

    Damaschke, Giesbert

    2015-01-01

    Sie haben schon eigene Webseiten gebaut und mochten diese nun mit Funktionen ausstatten, fur die Sie PHP und MySQL benotigen? Giesbert Damaschke zeigt Ihnen in diesem Buch, wie Sie das schaffen. Schritt fur Schritt erlernen Sie die benotigten Programmier- und Datenbankgrundlagen - immer im Rahmen von typischen dynamischen Anwendungen. So erheben und speichern Sie zum Beispiel mit Formularen Kontaktdaten, prufen Benutzereingaben, erstellen Menus, richten einen Besucherzahler ein, verschicken E-Mails mit PHP oder entwickeln sogar einen eigenen Blog. Alle Codebeispiele werden ausfuhrlich erklart,

  7. Wirkungen eines Bifidojoghurts mit Laktulose und eines konventionellen Joghurts auf Darmphysiologie und bakterielle Metaboliten als Risikomodulatoren der Kolonkarzinogenese sowie Darmflora und Blutlipide bei gesunden Erwachsenen

    OpenAIRE

    Gerlach, Stefanie

    2007-01-01

    Hintergrund: Probiotische und synbiotische Milchprodukte zählen zu den "funktionellen Lebensmitteln", denen im Vergleich zu herkömmlichen Produkten ein gesundheitsfördernder Zusatznutzen zugeschrieben wird. Dabei wird diskutiert, ob die Gesundheit bereits gesunder Personen noch optimierbar ist, ob und in welcher Weise die Darmflora gezielt "günstig" modifiziert werden kann und/oder ob diese Manipulation zu messbaren gesundheitsfördernden Veränderungen metabolischer und systemischer Biomarker ...

  8. Editorial: Theoriebildung in Mediendidaktik und Wissensmanagement

    Directory of Open Access Journals (Sweden)

    Michael Kerres

    2002-10-01

    Full Text Available Das Internet trägt massgeblich zur Entstehung einer neuen Lern- und Wissenskultur bei und ist mittlerweile Gegenstand einer ganzen Reihe von Projekten in der Erziehungswissenschaft. So wird zum Beispiel der Frage nachgegangen, welche Möglichkeiten der Strukturierung und Gestaltung von Lernmaterialien am besten geeignet sind, um Lernprozesse anzuregen, wie die interpersonale Kommunikation im Internet durch didaktische Gestaltungsmassnahmen gefördert werden können oder wie die entfernte Betreuung von Lernenden über das Netz funktioniert. Zunehmend wird dabei auch der Übergang bedeutsam zwischen didaktisch aufbereiteten Lernangeboten, wie sie die Mediendidaktik traditionell beschäftigt, und dem Austausch von nicht didaktisch aufbereiteten Informationen in Organisationen, wie es im Bereich des Wissensmanagements diskutiert wird. In diesen Projekten werden vielfach Detailfragen behandelt, und isoliert, ohne Bezug zu grundlegenden Theoriefragen untersucht. Es mangelt an einer genuin mediendidaktischen Theoriediskussion, die einen übergreifenden Bezugsrahmen aus erziehungswissenschaftlicher Perspektive liefert. In der Vergangenheit ist die Mediendidaktik von Seiten einer «kritischen» Medienpädagogik zeitweise skeptisch beäugt und in ihrer Existenz grundlegend infrage gestellt worden. In der aktuellen Diskussion wird gerne auf lerntheoretische Ansätze zurückgegriffen, die Lernen als aktiven Vorgang der individuellen und kooperativen Wissenskonstruktion begreifen. Doch Wissens- und Lerntheorien ersetzen keine mediendidaktische Modell- und Theoriebildung, die Perspektiven für eine Gestaltung zukünftiger Lernwelten liefert und dabei zum Beispiel sowohl bildungstheoretische Überlegungen als auch Konzepte des instructional design einbezieht. In dem ersten Teil dieser Ausgabe geht es um theoretische Perspektiven der Mediendidaktik. So diskutiert der Artikel von Michael Kerres und Claudia de Witt den Beitrag der Positionen von Behaviorismus

  9. Symmetriebrechung und Emergenz in der Kosmologie.

    Science.gov (United States)

    Mainzer, K.

    Seit der Antike wird der Aufbau des Universums mit einfachen und regulären (symmetrischen) Grundstrukturen verbunden. Diese Annahme liegt selbst noch den Standardmodellen der relativistischen Kosmologie zugrunde. Demgegenüber läßt sich die Emergenz neuer Strukturen von den Elementarteilchen über Moleküle bis zu den komplexen Systemen des Lebens als Symmetriebrechung verstehen. Symmetriebrechung und strukturelle Komplexität bestimmen die kosmische Evolution. Damit zeichnet sich ein fachübergreifendes Forschungsprogramm von Physik, Chemie und Biologie ab, in dem die Evolution des Universums untersucht werden kann.

  10. Die Ware Buch und die Philologie

    Directory of Open Access Journals (Sweden)

    Bernhard Hurch

    2017-10-01

    Full Text Available Die im 19. Jahrhundert sich verändernden Produktionsbedingungen für Druckwerke (Buchdruck, Satz, Papier, Bindung wirkten katalysierend auf die Fachkonstitution und Institutionalisierung der Philologien. Hier steht der tatsächliche Buchmarkt im Vordergrund der Darstellung, das Käuferpublikum und die Voraussetzungen des Vertriebs. Dazu gehören auch die Rezension als entstehende Textsorte und die rasch arbeitenden Rezensionsorgane. F.-R. Hausmann wurde in den letzten Jahren unentbehrlicher Mitarbeiter dieses im Rahmen des Grazer Schuchardt-Projekts "Netzwerk des Wissens" angesiedelten Ansatzes.

  11. Fluchen und Flamen, um ein Mann zu sein? Die Verknüpfung von Geschlecht und Sprache durch Vorurteile

    Directory of Open Access Journals (Sweden)

    Nicola Döring

    2001-11-01

    Full Text Available Die hier besprochene Monographie der Linguistin Anja Gottburgsen beschäftigt sich theoretisch und empirisch mit sprachbezogenen Geschlechterstereotypen, also mit unseren Vorstellungen darüber, ob und wie Männer und Frauen jeweils in spezifischer und distinkter Weise sprachlich kommunizieren. Im Theorieteil der Arbeit wird der aktuelle Stand der soziolinguistischen und sozialpsychologischen Diskussion zu Geschlecht, Sprachverhalten und Stereotypisierung kritisch referiert und die Bedeutung von sprachbezogenen Geschlechterstereotypen erläutert. Im empirischen Teil berichtet die Autorin die Ergebnisse von drei Fragebogen-Studien mit deutschsprachigen Studierenden. Es zeigt sich, dass bei Studierenden unabhängig von Geschlecht und Geschlechtsrollenorientierung stereotype Vorstellungen über das sprachliche Verhalten von Männern und Frauen verbreitet sind.

  12. [Das Bild und die Wahrnehmung der Stadt und der städtischen Gesellschaft im Hanseraum im Mittelalter und in der frühen Neuzeit] / Juhan Kreem

    Index Scriptorium Estoniae

    Kreem, Juhan

    2009-01-01

    Arvustus: Das Bild und die Wahrnehmung der Stadt und der städtischen Gesellschaft im Hanseraum im Mittelalter und in der frühen Neuzeit. hrsg. v. Roman Czaja. Torun, 2004. Torunis 2002. aastal toimunud konverentsi materjalid. Projekti "Pilt ja linn" raames ilmunud publikatsioonide loendit saab näha aadressil http://www.historiaurbium.org/english/attivita_images_en.html.

  13. HDR and LDR Brachytherapy in the Treatment of Lip Cancer: the Experience of the Catalan Institute of Oncology.

    Science.gov (United States)

    Ayerra, Arrate Querejeta; Mena, Estefanía Palacios; Fabregas, Joan Pera; Miguelez, Cristina Gutiérrez; Guedea, Ferran

    2010-03-01

    Lip cancer can be treated by surgery, external radiotherapy, and/or brachytherapy (BT). In recent years, BT has become increasingly favored for this type of cancer. The aim of the present study was to analyze local control and survival of patients treated at our institution between July 1989 and June 2008. We performed a retrospective study of 121 patients (109 males and 12 females) who underwent lip cancer brachytherapy from July 1989 to June 2008. Median age was 67 years and median follow-up was 31.8 months (range 20-188 months). Out of 121 patients, 100 (82.6%) were treated with low dose rate (LDR) BT while the remaining 21 patients (17.4%) received high dose rate (HDR) BT. The most common cell type was squamous cell carcinoma (115 cases; 95%) and most tumors were located on the lower lip (107 patients; 88.4%). Most cases were either stage T1 (62 patients; 51.2%), or T2 (44 cases; 36.4%). After 15 years of follow-up, overall survival was 89.5%, cause-specific survival 97.8%, and disease-free survival 86.6%. Local, regional, and distant control at 15 years were 90%, 92%, and 98.8%, respectively. Grade 3 mucosal toxicity was observed in 23% of patients treated with LDR compared to 33% of HDR patients, and grade 4 mucosal toxicity in 9% versus 0% in the HDR group. Our findings confirm that brachytherapy is an effective treatment for lip cancer. The results from our series are in line with those published elsewhere. Based on our limited data, HDR appears to be equally as good as LDR, although this needs to be confirmed by further studies.

  14. 13. status report of the project HDR safety program of Kernforschungszentrum Karlsruhe. Working report 05.46/89

    International Nuclear Information System (INIS)

    Katzenmeier, G.

    1989-01-01

    The programme phase III, which extends to the end of 1991, is divided into the part projects containment behaviour in extreme accidents, long-term damage and monitoring the components in operation, behaviour of damaged components in dynamic accidents and large fires of actual materials. The main aims, state of the HDR safety programme, main points of the programme for 1990 and 8 technical reports on phase II and III are documented. There is a survey of costs. (DG) [de

  15. Energy-dispersive study of the interaction of fast neutrons with matter. Common final report of the DFG projects GR 1674/2 and FR 575/5 together with the institute for nuclear and particle physics, technical university Dresden; Energiedispersive Untersuchung der Wechselwirkung schneller Neutronen mit Materie. Gemeinsamer Abschlussbericht der DFG Projekte GR 1674/2 und FR 575/5, zusammen mit dem Institut fuer Kern- und Teilchenphysik, Technische Universitaet Dresden

    Energy Technology Data Exchange (ETDEWEB)

    Altstadt, E.; Beckert, C. [Forschungszentrum Rossendorf e.V. (FZR) (Germany). Inst. fuer Sicherheitsforschung; Beyer, R. [Forschungszentrum Rossendorf e.V. (FZR), Dresden (DE). Inst. fuer Kern- und Hadronenphysik] [and others

    2005-04-01

    In this final report on the research project ''Energy-dispersive study of the interaction of fast neutrons with matter, especially materials for fusion and materials from fission reactors the status reached after three years promotion is described. The aim of this project is the construction and first usage of a very complex time-of-flight system for the study of the interaction of fast neutrons with construction materials for fusion and fission reactors as well as with long-lived radioisotopes. Furthermore astrophysically relevant experiments on problems of the element synthesis shall be performed. The whole project is devided into two sections: 1. Development, construction and test of a pulsed photoneutron source at the ELBE accelerator of the FZ Rossendorf, 2. Application of the photoneutron sources for measurements of cross sections induced by fast, energy-selected neutrons.

  16. Diagnostik und Therapie der kutanen Androgenisierung im klimakterischen Übergang sowie in der Peri- und Postmenopause: Hirsutismus und Alopezie

    Directory of Open Access Journals (Sweden)

    Geisthövel F

    2012-01-01

    Full Text Available Die weibliche Androgenisierung umfasst ein weites Spektrum an heterogenen Dysfunktionen und Erkrankungen. Um die Therapieprinzipien des Hirsutismus sowie der Alopecia androgenetica während des klimakterischen Übergangs („menopausal transition“ [MT] und der Peri-/Postmenopause zu erfassen, ist es sinnvoll, sich auf eine Gruppe von androgenisierten Patientinnen zu beschränken, bei der die Haut pathogenetisch im Fokus liegt. Solch eine klar definierte Patientengruppe, die „funktionell kutane Androgenisierung“ (FCA, kann meist schon über die Diagnostikebene 1 (Screening-Ebene unseres Klassifikations-Algorithmus diagnostiziert werden. Der Ferriman-Gallwey-Index bzw. eine modifizierte Sinclair-Scale dienen zur Gradeinteilung von Hirsutismus bzw. Alopezie. Die ausgeprägte endokrine Dynamik während der MT ist hormondiagnostisch zu beachten. Wachsepilation und Lasertherapie sind vielfältig eingesetzte topischmechanische bzw. -physikalische Therapieverfahren. Eine topische Behandlung des Hirsutismus kann auch mit Eflornithin-Creme durchgeführt werden, die den Effekt einer Lasertherapie unterstützt. Minoxidil-Lösung gilt als Mittel der ersten Wahl bei der topischen Therapie der Alopecia androgenetica. Steroidale Präparate, welche aus der kontrazeptiven Kombination von Ethinylestradiol und antiandrogenen Gestagenen (AA bestehen, sind therapeutische Prinzipien bei androgenisierten Patientinnen in der MT, sie sind hingegen in der Postmenopause kontraindiziert. Die orale Einnahme von Spironolacton und/oder Finasterid, beides nicht-steroidale Antiandrogene, ist während der MT unter sicherer Kontrazeption und jene von Spironolacton für die Alopezie in der Postmenopause gut geeignet. Die Einnahme von Kombinationsprapäraten, welche die nicht-kontrazeptiven natürlichen Östrogene und AA enthalten, sind für die Behandlung der FCA bei Patientinnen indiziert, die zusätzlich unter klimakterischen und peri-/postmenopausalen Störungen leiden

  17. Struktur und Dynamik in der Netzwerkanalyse

    NARCIS (Netherlands)

    Trier, M.; Stegbauer, C.; Häußling, R.

    2010-01-01

    Die Methodik der sozialen Netzwerkanalyse (SNA) ist auf die quantitative Untersuchung von strukturellen Mustern in Graphen ausgerichtet. Die Analyse arbeitet gegenwärtig meist mit Daten aus einer einmaligen und kumulierten Erhebung der Netzwerkstruktur zu einem bestimmten Zeitpunkt. Diese

  18. Satellitenbewegung, band III: Natiirliche und gesteuerte bewegung.

    Science.gov (United States)

    Jochim, E. F.

    2014-12-01

    Im dritten Band der Satellitenbewegung werden in fortlaufender Nummerierung einige für Untersuchungen der Bewegung der künstlichen Satelliten wichtige Grundlagen der Astrodynamik mit ausführlichen mathematischen Formelsystemen behandelt. Dazu zählen die unterschiedlichen Aspekte der Bewegung der natürlichen Himmelskörper, die Steuerung und Kontrolle von künstlichen Objekten, und insbesondere die für eine Satellitenbahnanalyse wichtigen physikalischen Beeinflussungen einer Satellitenbewegung. Mathematisch entscheidend ist die Wahl geeigneter Bahnparameter, die ein bestimmtes Bewegungsproblem widerspruchsfrei und singularitätenfrei zu behandeln gestatten. Für die Behandlung routinemäßiger Aufgabenstellungen der Satellitenbewegung, in erster Linie einer präzisen Bahnbestimmung und Bahnverbesserung, kann auf eine Fülle von lehrbuchartigen Monographien verwiesen werden, so dass diese Problematik in der vorliegenden Arbeit nur angedeutet werden soll.

  19. Riots ‒ Anmerkungen zu Begriff und Konzept

    Directory of Open Access Journals (Sweden)

    Dieter Rucht

    2016-05-01

    Full Text Available Ausgehend von sozialwissenschaftlichen Befunden werden zunächst ältere massenpsychologische Deutungen von riots zurückgewiesen. Die überwiegende Mehrzahl der im riot Aufbegehrenden entspricht nicht dem Typus entfremdeter und verängstigter Einzeltäter_innen. Zweitens benennt der Beitrag eine Reihe von Bedingungen für das Zustandekommen von riots. Drittens wird der Begriff ‚riot‘ in formaler Hinsicht näher bestimmt und einerseits von moderateren Formen des Protests, andererseits von geplanter und organisierter Gewalt (z. B. Terrorismus abgegrenzt. Abschließend wird die Frage des politischen Gehalts von riots und deren normativen Grundlagen erörtert.

  20. Acute genitourinary toxicity after high-dose-rate (HDR) brachytherapy combined with hypofractionated external-beam radiation therapy for localized prostate cancer: Correlation between the urethral dose in HDR brachytherapy and the severity of acute genitourinary toxicity

    International Nuclear Information System (INIS)

    Akimoto, Tetsuo; Ito, Kazuto; Saitoh, Jun-ichi; Noda, Shin-ei; Harashima, Koichi; Sakurai, Hideyuki; Nakayama, Yuko; Yamamoto, Takumi; Suzuki, Kazuhiro; Nakano, Takashi; Niibe, Hideo

    2005-01-01

    Purpose: Several investigations have revealed that the α/β ratio for prostate cancer is atypically low, and that hypofractionation or high-dose-rate (HDR) brachytherapy regimens using appropriate radiation doses may be expected to yield tumor control and late sequelae rates that are better or at least as favorable as those achieved with conventional radiation therapy. In this setting, we attempted treating localized prostate cancer patients with HDR brachytherapy combined with hypofractionated external beam radiation therapy (EBRT). The purpose of this study was to evaluate the feasibility of using this approach, with special emphasis on the relationship between the severity of acute genitourinary (GU) toxicity and the urethral dose calculated from the dose-volume histogram (DVH) of HDR brachytherapy. Methods and Materials: Between September 2000 and December 2003, 70 patients with localized prostate cancer were treated by iridium-192 HDR brachytherapy combined with hypofractionated EBRT at the Gunma University Hospital. Hypofractionated EBRT was administered in fraction doses of 3 Gy, three times per week; a total dose of 51 Gy was delivered to the prostate gland and the seminal vesicles using the four-field technique. No elective pelvic irradiation was performed. After the completion of EBRT, all the patients additionally received transrectal ultrasonography (TRUS)-guided HDR brachytherapy. The fraction size and the number of fractions in HDR brachytherapy were prospectively changed, whereas the total radiation dose for EBRT was fixed at 51 Gy. The fractionation in HDR brachytherapy was as follows: 5 Gy x 5, 7 Gy x 3, 9 Gy x 2, administered twice per day, although the biologic effective dose (BED) for HDR brachytherapy combined with EBRT, assuming that the α/β ratio is 3, was almost equal to 138 in each fractionation group. The planning target volume was defined as the prostate gland with 5-mm margin all around, and the planning was conducted based on

  1. Dosimetric measurements of an 192Ir HDR source with a diamond detector

    International Nuclear Information System (INIS)

    Rustgi, Surendra N.

    1996-01-01

    Purpose: To study the feasibility of using a diamond detector for the dosimetry of a high dose rate (HDR) 192 Ir source and to compare the measurement results with published data and calculations from a commercial treatment planning system. Materials and methods: The sensitive volume of the diamond detector consists of a disk of 0.26 mm thickness and 3 mm diameter. The detector was applied an external bias of +100 V and was preirradiated to a dose of 500 cGy to stabilize its response. The 192 Ir source from the Nucletron microSelectron unit has an active diameter of 0.6 mm and a length of 3.5 mm. Photon fluence anisotropy factors in air were measured at distances of 5 and 10 cm from two sources and compared with TLD measurements. Dose profiles and isodose distributions were measured at several distances from the source and compared with calculations from a Nucletron treatment planning system. These dose calculations in water use a point source approximation with the anisotropy factors independent of the radial distance from the source. Results: The photon fluence around the 192 Ir HDR source, measured with a diamond detector at distances of 5 and 10 cm from the source, is very anisotropic. Compared to the source transverse direction, the photon fluence intensity along the source axis reduces to approximately 60%. Measurements performed on two sources indicate that the photon anisotropy does not change with distance in air. Within experimental uncertainty, similar results were obtained with TLD rods and are in excellent agreement with published anisotropy factors 1 . Dose profiles, measured with the diamond detector in a water phantom, at distances of 1,2,3 and 5 cm from the source, are found to be in excellent agreement with the Nucletron planning system calculations. Similar excellent agreement is observed between the measured and calculated isodose curves in planes parallel to the source plane. Conclusion: The diamond detector has been demonstrated to be suitable

  2. NPIP: A skew line needle configuration optimization system for HDR brachytherapy

    International Nuclear Information System (INIS)

    Siauw, Timmy; Cunha, Adam; Berenson, Dmitry; Atamtürk, Alper; Hsu, I-Chow; Goldberg, Ken; Pouliot, Jean

    2012-01-01

    Purpose: In this study, the authors introduce skew line needle configurations for high dose rate (HDR) brachytherapy and needle planning by integer program (NPIP), a computational method for generating these configurations. NPIP generates needle configurations that are specific to the anatomy of the patient, avoid critical structures near the penile bulb and other healthy structures, and avoid needle collisions inside the body. Methods: NPIP consisted of three major components: a method for generating a set of candidate needles, a needle selection component that chose a candidate needle subset to be inserted, and a dose planner for verifying that the final needle configuration could meet dose objectives. NPIP was used to compute needle configurations for prostate cancer data sets from patients previously treated at our clinic. NPIP took two user-parameters: a number of candidate needles, and needle coverage radius, δ. The candidate needle set consisted of 5000 needles, and a range of δ values was used to compute different needle configurations for each patient. Dose plans were computed for each needle configuration. The number of needles generated and dosimetry were analyzed and compared to the physician implant. Results: NPIP computed at least one needle configuration for every patient that met dose objectives, avoided healthy structures and needle collisions, and used as many or fewer needles than standard practice. These needle configurations corresponded to a narrow range of δ values, which could be used as default values if this system is used in practice. The average end-to-end runtime for this implementation of NPIP was 286 s, but there was a wide variation from case to case. Conclusions: The authors have shown that NPIP can automatically generate skew line needle configurations with the aforementioned properties, and that given the correct input parameters, NPIP can generate needle configurations which meet dose objectives and use as many or fewer

  3. Fast, automatic, and accurate catheter reconstruction in HDR brachytherapy using an electromagnetic 3D tracking system

    Energy Technology Data Exchange (ETDEWEB)

    Poulin, Eric; Racine, Emmanuel; Beaulieu, Luc, E-mail: Luc.Beaulieu@phy.ulaval.ca [Département de physique, de génie physique et d’optique et Centre de recherche sur le cancer de l’Université Laval, Université Laval, Québec, Québec G1V 0A6, Canada and Département de radio-oncologie et Axe Oncologie du Centre de recherche du CHU de Québec, CHU de Québec, 11 Côte du Palais, Québec, Québec G1R 2J6 (Canada); Binnekamp, Dirk [Integrated Clinical Solutions and Marketing, Philips Healthcare, Veenpluis 4-6, Best 5680 DA (Netherlands)

    2015-03-15

    Purpose: In high dose rate brachytherapy (HDR-B), current catheter reconstruction protocols are relatively slow and error prone. The purpose of this technical note is to evaluate the accuracy and the robustness of an electromagnetic (EM) tracking system for automated and real-time catheter reconstruction. Methods: For this preclinical study, a total of ten catheters were inserted in gelatin phantoms with different trajectories. Catheters were reconstructed using a 18G biopsy needle, used as an EM stylet and equipped with a miniaturized sensor, and the second generation Aurora{sup ®} Planar Field Generator from Northern Digital Inc. The Aurora EM system provides position and orientation value with precisions of 0.7 mm and 0.2°, respectively. Phantoms were also scanned using a μCT (GE Healthcare) and Philips Big Bore clinical computed tomography (CT) system with a spatial resolution of 89 μm and 2 mm, respectively. Reconstructions using the EM stylet were compared to μCT and CT. To assess the robustness of the EM reconstruction, five catheters were reconstructed twice and compared. Results: Reconstruction time for one catheter was 10 s, leading to a total reconstruction time inferior to 3 min for a typical 17-catheter implant. When compared to the μCT, the mean EM tip identification error was 0.69 ± 0.29 mm while the CT error was 1.08 ± 0.67 mm. The mean 3D distance error was found to be 0.66 ± 0.33 mm and 1.08 ± 0.72 mm for the EM and CT, respectively. EM 3D catheter trajectories were found to be more accurate. A maximum difference of less than 0.6 mm was found between successive EM reconstructions. Conclusions: The EM reconstruction was found to be more accurate and precise than the conventional methods used for catheter reconstruction in HDR-B. This approach can be applied to any type of catheters and applicators.

  4. Fast, automatic, and accurate catheter reconstruction in HDR brachytherapy using an electromagnetic 3D tracking system

    International Nuclear Information System (INIS)

    Poulin, Eric; Racine, Emmanuel; Beaulieu, Luc; Binnekamp, Dirk

    2015-01-01

    Purpose: In high dose rate brachytherapy (HDR-B), current catheter reconstruction protocols are relatively slow and error prone. The purpose of this technical note is to evaluate the accuracy and the robustness of an electromagnetic (EM) tracking system for automated and real-time catheter reconstruction. Methods: For this preclinical study, a total of ten catheters were inserted in gelatin phantoms with different trajectories. Catheters were reconstructed using a 18G biopsy needle, used as an EM stylet and equipped with a miniaturized sensor, and the second generation Aurora ® Planar Field Generator from Northern Digital Inc. The Aurora EM system provides position and orientation value with precisions of 0.7 mm and 0.2°, respectively. Phantoms were also scanned using a μCT (GE Healthcare) and Philips Big Bore clinical computed tomography (CT) system with a spatial resolution of 89 μm and 2 mm, respectively. Reconstructions using the EM stylet were compared to μCT and CT. To assess the robustness of the EM reconstruction, five catheters were reconstructed twice and compared. Results: Reconstruction time for one catheter was 10 s, leading to a total reconstruction time inferior to 3 min for a typical 17-catheter implant. When compared to the μCT, the mean EM tip identification error was 0.69 ± 0.29 mm while the CT error was 1.08 ± 0.67 mm. The mean 3D distance error was found to be 0.66 ± 0.33 mm and 1.08 ± 0.72 mm for the EM and CT, respectively. EM 3D catheter trajectories were found to be more accurate. A maximum difference of less than 0.6 mm was found between successive EM reconstructions. Conclusions: The EM reconstruction was found to be more accurate and precise than the conventional methods used for catheter reconstruction in HDR-B. This approach can be applied to any type of catheters and applicators

  5. [Die baltischen Lande im Zeitalter der Reformation und Konfessionalisierung : Livland, Estland, Ösel, Ingermanland, Kurland und Lettgallen. Stadt, Land und Konfession 1500-1721. Teil 1.] / Jürgen Beyer

    Index Scriptorium Estoniae

    Beyer, Jürgen, 1965-

    2010-01-01

    Arvustus: Die baltischen Lande im Zeitalter der Reformation und Konfessionalisierung. Livland, Estland, Ösel, Ingermanland, Kurland und Lettgallen. Stadt, Land und Konfession 1500-1721. Teil 1. (Münster : Aschendorff, 2009)

  6. Matthias Asche, Werner Buchholz, Anton Schindling (Hrsg.): Die baltischen Lande im Zeitalter der Reformation und Konfessionalisierung. Livland, Estland, Ösel, Ingermanland, Kurland und Lettgallen. Stadt, Land und Konfession 1500-1721. Tl. 2, Münste

    Index Scriptorium Estoniae

    Wittram, Heinrich, 1931-

    2011-01-01

    Arvustus: Die baltischen Lande im Zeitalter der Reformation und Konfessionalisierung : Livland, Estland, Ösel, Ingermanland, Kurland und Lettgallen : Stadt, Land und Konfession 1500-1721. Teil 2. Münster, 2010

  7. Benjamin Ortmeyer: Mythos und Pathos statt Logos und Ethos, Zu den Publikationen führender Erziehungswissenschaftler in der NS-Zeit: Eduard Spranger, Herman Nohl, Erich Weniger und Peter Petersen, Weinheim / Basel: Beltz 2009 [Rezension

    OpenAIRE

    Zimmer, Hasko

    2010-01-01

    Rezension von: Benjamin Ortmeyer: Mythos und Pathos statt Logos und Ethos, Zu den Publikationen führender Erziehungswissenschaftler in der NS-Zeit: Eduard Spranger, Herman Nohl, Erich Weniger und Peter Petersen, Weinheim / Basel: Beltz 2009, 606 S.

  8. The humanities and innovation; Geisteswissenschaften und Innovationen

    Energy Technology Data Exchange (ETDEWEB)

    Meyer-Krahmer, F.; Lange, S. [eds.] [Fraunhofer-Institut fuer Systemtechnik und Innovationsforschung (ISI), Karlsruhe (Germany)

    1999-07-01

    The book discusses the concept and process of innovation from the perspective of linguistics, historical sciences, and philosophy. Inter-disciplinary relations become evident when it comes to research into human consciousness and behaviour, dealing with language and texts, or the growing significance of the historical sciences with respect to topical developments in technology and the economy. The cross-disciplinary discourse between the various disciplines of the humanities, natural sciences, technology and the social sciences, and between science, industry and public administration has revealed a new playing field for cross-disciplinary dialogue and cooperative action that may be rewarding. The book discusses aspects such as the innovative potential of the humanities, or their possible contributions to innovation, their capabilities to generate innovative changes in the way of thinking, to prepare the ground for innovation, strengthen innovative abilities, and on the other hand to hold aloof and keep a watchful eye on innovation. (orig./CB) [German] Das Buch beschaeftigt sich mit Innovationen aus sprachwissenschaftlicher, historischer und philosophischer Sicht. Querbezuege werden deutlich, wenn es um die Erforschung von Bewusstsein und Verhalten, dem Umgang mit Sprache und Texten oder die wachsende Bedeutung der historischen Wissenschaften fuer die aktuelle technologische und wirtschaftliche Entwicklung geht. Das Gespraech ueber Fachgrenzen hinweg zwischen den verschiedenen Disziplinen der Geisteswissenschaften, der Natur-, Technik- und Sozialwissenschaften und zwischen Wissenschaft, Industrie und oeffentlicher Verwaltung hat Aufgaben deutlich gemacht, die die Zusammenarbeit lohnen. In diesem Band wird diskutiert, welches Innovationspotential die Geisteswissenschaften bieten, wie diese zu Innovationen beitragen, Innovationen im Denken hervorbringen, Vorarbeiten fuer Innovationen leisten, die Innovationsfaehigkeit staerken und die kritische Distanz zu Innovationen

  9. Neue Technologien und Erziehung/Bildung

    Directory of Open Access Journals (Sweden)

    Norbert Meder

    2015-03-01

    Full Text Available Es wird gezeigt, dass Computertechnologie zur pädagogischen Aufgabe wird, weil es sich um eine Kulturtechnik handelt. Ausgehend vom Begriff der Bildung als Ausbildung eines Verhältnisses zu mir selbst, zu anderen und zur Welt wird Computertechnologie als Problemlösungsautomat, Sprachentwicklungsmaschine, Simulationsmaschine, Kommunikationsmaschine, Bildschirmgestaltungsmaschine, Schlüsselloch und Superzeichenmaschine analysiert. Die Analyse zeigt, daß Computertechnologie ein neues Bildungsideal erforderlich macht: Den Sprachspieler. Der Sprachspieler kennt sein doppelt reflexives Verhältnis zu sich selbst, zu anderen und zur Welt und beherrscht so das Spiel mit der Sprache zur Ausübung von Macht und Gewalt in der Informationsgesellschaft. Der Text geht in folgenden Schritten vor: Zunächst werden mit den Begriffen "Kulturtechnik" und "Bildung" die Prinzipien der Analyse bestimmt. Anschließend wird eine Sachanalyse der Computertechnologie durchgeführt und die gefundenen Eigenschaften jeweils in Relation zum Kulturtechnik- und Bildungsbegriff gesetzt. Computer technology becomes a challenge for education if it is understood as a cultural technology. Starting with the term bildung as the formation of relations to my self, to others and the world, computer technology is analysed as problem solving machine, language development machine, simulation machine, communication machine, screen design machine, keyhole, and super sign machine. It is shown, that computertechnology reqiures a new ideal for bildung: the language player. The language player knows his double reflective relation to his self, to others and the world and thus rules the game with language that is used to excercise power and force in the information society. The text argues in the following steps: At first the principles of the analyses are defined with the terms cultural technology and bildung. Susequently, computer technology is analysed. The identified qualities are finally

  10. Medien als Lernform und die Trimediale Redaktion

    Directory of Open Access Journals (Sweden)

    Wolf Hilzensauer

    2015-01-01

    Full Text Available Der vorliegende Artikel beschreibt ein Konzept für eine handlungsorientierte Medienpädagogik im Bildungsbereich. Im Mittelpunkt steht dabei die SO!-Campusredaktion, die als Methode für expansives Lernen die Möglichkeit bietet, unabhängig von Thema oder Medium die Verantwortung für den Lernprozess in die Hände der Lernenden zu legen. Der Dokumentation von Reflexion über den Lernprozess wird dabei eine besondere Bedeutung zugesprochen. Gleichzeitig werden unterschiedliche mediale Gestaltungsmöglichkeiten (Audio/Radio, Video/Fernsehen und Zeitung – sowohl als Print- als auch als Onlinemedium vorgestellt, die durch das Konzept BYOD – bring your own device – auch einfach und niederschwellig im Bildungskontext umsetzbar sind. Dadurch ergeben sich innovative Möglichkeiten, einen Lernprozess sichtbar zu machen und gleichzeitig eine Grundlage für eine alternative Leistungsbeurteilung anzubieten. Die SO!-Campusredaktion wird derzeit an der Pädagogischen Hochschule Salzburg in Kooperation mit dem Communitysender FS1 und der Radiofabrik entwickelt und erprobt. Community Medien nehmen als MedienpartnerInnen eine bedeutende Stellung ein: Durch ihren offenen Zugang zu Know How und Equipment sowie durch die Möglichkeit, Medienproduktionen über die verfügbaren Distibutionskanäle (Radiofrequenz oder Sendeplatz einer breiten Bevölkerung zugänglich zu machen, gewinnt die Medienpädagogik einen wichtigen Mehrwert in ihrer schulischen und außerschulischen Arbeit. (Dieser Artikel knüpft an den Artikel "BYOD, Smartphonefilme und webbasierte Videoschnittprogramme" der Medienimpulse, Ausgabe 2/2014, an.

  11. Polen, Deutschland, die EU und Russland

    OpenAIRE

    Wilkiewicz, Zbigniew

    2009-01-01

    Besonders seit dem EU-Beitritt Polens ist es um die deutsch-polnischen Beziehungen nicht besonders gut bestellt. In den vergangenen Jahren hat man sich in erster Linie an bilateralen Konflikten abgearbeitet und keine gemeinsame Europapolitik betrieben. Im Beitrag wird diese Entwicklung rekonstruiert und danach gefragt, ob es angesichts einer solchen Entwicklung Aussichten auf die Wiederherstellung der deutsch-polnischen Interessengemeinschaft gibt oder die Interessen beider Staaten so stark d...

  12. Professionelle Literaturrecherche und -verwaltung im Web [Praxisbericht

    OpenAIRE

    Schaffert, Sandra

    2007-01-01

    In diesem Beitrag werden Hinweise für eine professionelle Literaturrecherche und -verwaltung im World Wide Web gegeben. Dazu werden für die pädagogische Ausbildung und Forschung einschlägige Literaturdatenbanken genannt, insbesondere solche, die kostenlos zu nutzen sind. Außerdem werden Tipps für clevere Recherchen sowie eine kurze Übersicht über Web-Werkzeuge zur Verwaltung von bibliografischen Angaben gegeben. (DIPF/Orig.)

  13. Ontologische und epistemologische Grundlagen qualitative Forschung

    OpenAIRE

    Vasilachis de Gialdino, Irene

    2009-01-01

    Dieser Beitrag zielt auf das Herzstück qualitativer Forschung, indem gezeigt wird, dass es – aus der Perspektive einer Epistemologie des "gewussten" Subjekts – erforderlich ist, zunächst deren ontologische und dann deren epistemologische Grundlagen neu zu überdenken. Hierzu zeichne ich in einem ersten Schritt den Weg von einer Epistemologie des "bewussten" Subjekts hin zu einer Epistemologie des "gewussten" Subjekts nach, die ich als neuen (und nicht exklusiven) Weg des Wissens vorschlage. Da...

  14. Generation Y: Arbeitsbezogene Erwartungen und affektives Commitment

    OpenAIRE

    Giry, Nathalie

    2016-01-01

    Die Erwartungen der Generation Y zu kennen, ist wichtig für Unternehmen, die Leistungsträger aus dieser Generation langfristig binden wollen. Die affektive Bindung der Generation Y gegenüber einer Organisation, der Zusammenhang zwischen der Erfüllung arbeitsbezogener Erwartungen und affektivem Commitment sowie der Fluktuationsneigung der Generation Y werden empirisch überprüft. Die Generation Y hat hohe Erwartungen an Unternehmenswerte und Unternehmenskultur. Es wurden Zusammenhänge zwischen ...

  15. Climate and transportation; Klima und Verkehr

    Energy Technology Data Exchange (ETDEWEB)

    Fabian, P. [Muenchen Univ. (Germany). Lehrstuhl fuer Bioklimatologie und Immissionsforschung

    1996-06-01

    This short contribution discusses emissions of the transportation sector, i.e. the global problem of carbon dioxide emissions and the regional ecological problem of nitric oxide, VOC and CO photosmog emissions. Reduction strategies are discussed. (RHM) [Deutsch] Im vorliegenden, kurzen Beitrag wird auf die Emissionen des Verkehrs, die Emissionen von CO{sub 2} - ein globales Klimaproblem - sowie die Emission von NO{sub x}, VOCs und CO-Photosmog als regionals Umwelt- und Klimaproblem eingegangen. Abschliessend werden Reduktionsstrategien dieskutiert. (RHM)

  16. Entscheidungsprozesse und Partizipation in der Stadtentwicklung Dresdens

    OpenAIRE

    Schmidt-Lerm, Susanne

    2010-01-01

    Untersucht wurde die Auseinandersetzung um das Autobahnbauvorhaben A 17 Dresden - Prag zwischen 1990 und 1995 als ein Beispiel der Stadtentwicklung Dresdens. Seit 1935 als Reichsautobahn ins Sudetenland geplant, sollte dieses Verkehrsprojekt nach 1990 als „Lückenschluß im europäischen Autobahnnetz“ umgesetzt werden. Angesichts des hohen Konfliktpotentials erlangte der Fall überregionale Aufmerksamkeit und Beispielcharakter für die neuen Bundesländer. Die Kontroverse gipfelte im ersten Bürgere...

  17. Kolloide in externen elektrischen und magnetischen Feldern

    OpenAIRE

    Zhao, Jinyu

    2011-01-01

    Kolloide spielen eine wichtige Rolle in der Forschung. In vielen Anwendungsgebieten, beispielsweise Optik, Mikro- und Nanoelektronik, Mikrofluidik, Automobilindustrie, Mineralölindustrie, dienen sie sowohl als Testsubstanzen als auch "Werkzeug", um grundlegende Vorgänge zu erforschen. In der Grundlagenforschung dienen kolloidale Suspensionen als Modelle für atomare und molekulare Systeme. In der vorliegenden Arbeit habe ich Suspensionen aus festen Kolloiden (auch als Partikel bezeichnet) in e...

  18. Kurz zum Klima: Schiefergas und Fracking

    OpenAIRE

    Triebswetter, Ursula; Lippelt, Jana

    2012-01-01

    Das Verfahren zur Gewinnung von Erdgas aus wenig durchlässigem Gestein, das in den USA erfundene und dort bereits weit verbreitete »Hydraulic Fracturing«, kurz Fracking, ist aus Umweltgründen umstritten. Der Beitrag skizziert zunächst die Technologie des Fracking, umreißt dann die weltweiten Lagerstätten und beschreibt die umweltpolitische Problematik. Abschließend wird die aktuelle Situation in Deutschland dargestellt.

  19. RANK und RANKL - Vom Knochen zum Mammakarzinom

    Directory of Open Access Journals (Sweden)

    Sigl V

    2012-01-01

    Full Text Available RANK („Receptor Activator of NF-κB“ und sein Ligand RANKL sind Schlüsselmoleküle im Knochenmetabolismus und spielen eine essenzielle Rolle in der Entstehung von pathologischen Knochenveränderungen. Die Deregulation des RANK/RANKL-Systems ist zum Beispiel ein Hauptgrund für das Auftreten von postmenopausaler Osteoporose bei Frauen. Eine weitere wesentliche Funktion von RANK und RANKL liegt in der Entwicklung von milchsekretierenden Drüsen während der Schwangerschaft. Dabei regulieren Sexualhormone, wie zum Beispiel Progesteron, die Expression von RANKL und induzieren dadurch die Proliferation von epithelialen Zellen der Brust. Seit Längerem war schon bekannt, dass RANK und RANKL in der Metastasenbildung von Brustkrebszellen im Knochengewebe beteiligt sind. Wir konnten nun das RANK/RANKLSystem auch als essenziellen Mechanismus in der Entstehung von hormonellem Brustkrebs identifizieren. In diesem Beitrag werden wir daher den neuesten Erkenntnissen besondere Aufmerksamkeit schenken und diese kritisch in Bezug auf Brustkrebsentwicklung betrachten.

  20. Finanzkrise, Sozialkrise und ungleiche Entwicklung in Südkorea und Thailand

    DEFF Research Database (Denmark)

    Schmidt, Johannes Dragsbæk

    2008-01-01

    Zehn Jahre ist es inzwischen her, dass die Finanzkrisen in Südostasien, Russland und Lateinamerika die Weltwirtschaft erschütterten. Angesichts dieses "Jubiläums" und der aktuellen US-Finanzkrise ist es Zeit für eine Bestandsaufnahme: Lektionen gelernt? Drei Fragestellungen stehen im Mittelpunkt...

  1. Methoden der Kommunikations- und Mediengeschichte: die Wechselwirkung unterschiedlicher Verfahren als Spezifikum der Kommunikations- und Mediengeschichte

    NARCIS (Netherlands)

    Hemels, J.; Averbeck-Lietz, S.; Klein, P.; Meyen, M.

    2009-01-01

    Dieser Beitrag verfolgt zwei Ziele: Einerseits wird beabsichtigt, nicht his-torisch geschulte Kommunikationswissenschaftler mit Grundlagen und Praxis kommunikationswissenschaftlicher Forschung vertraut zu ma-chen. Andererseits wird für ein Zusammenspiel zwischen führenden For-schungsansätzen und

  2. Alexander Kratochvil. Aufbruch und Rückkehr: Ukrainische und tschechische Prosa im Zeichen der Postmoderne.

    Directory of Open Access Journals (Sweden)

    Marko Pavlyshyn

    2015-01-01

    Full Text Available Alexander Kratochvil. Aufbruch und Rückkehr: Ukrainische und tschechische Prosa im Zeichen der Postmoderne. [Venturing Forth and Coming Back: Ukrainian and Czech Prose in the Context of Postmodernity.] Berlin: Kulturverlag Kadmos, 2013. 311 pp. Bibliography. Index. Paper.

  3. A comprehensive study on HDR brachytherapy treatments of cervical cancers: using the first Co-60 BEBIG Multisource Unit in Bangladesh

    Directory of Open Access Journals (Sweden)

    Naheed Rukhsana

    2011-07-01

    Full Text Available Purpose: The report presents an extraordinary synthesis of customer acceptance procedures (CAP, quality assurance tests (QA in the treatment of cervical cancer patients, using the first Co-60 Multisource Unit® in Bangladesh. The QA and commissioning required measurements and emergency tests verifying the functional limits of parameters acceptable for the new HDR afterloader. Acceptable limits were: 1 the deviation between specified and measured source strength: ± 3%; 2 the positional accuracy and uniformity: ± 1 mm; 3 the temporal accuracy (i.e. timer error and linearity and end error: ± 1% or 30 sec.; 4 treatment planning system (digitizer and localization software: ± 3% or 1 mm; 5 the distance from line to first dwell position and all the others: 5 mm and 10 mm (± 1 mm. Material and methods: Till February 2011, 47 patients were treated with HDR with more than 140 insertions applied. Amongst them, 12 patients were in stage IIB and IIIB, 22 were postoperative (IA and IB while the remaining 13 patients were with unknown stage. All the cases with stage IIB and IIIB received concurrent chemo-radiation and brachytherapy. Postoperative patients received EBRT (50 Gy and HDR according to the institutional protocol. CT scans were completed before HDR-plus planning with a good reproducibility (± 2% and were documented in repeating the plan for the same set up of a patient. Absorbed dose (Gy to a point P, at a distance of “r” in centimeters from a source of the Reference Air Kerma Rate (RAKR has been utilized for the QA of the source, where source strength measurement was accomplished. Results: All methods and analysis applicable to the QA and commissioning of Co-60 have been investigated and systematically analyzed, measured and documented before the treatment of a patient. Studies and safety requirements of this HDR remote afterloader were carried out. Acceptance and the QA were imperative to justify functionality and dependability in

  4. A multicentre audit of HDR/PDR brachytherapy absolute dosimetry in association with the INTERLACE trial (NCT015662405)

    Science.gov (United States)

    Díez, P.; Aird, E. G. A.; Sander, T.; Gouldstone, C. A.; Sharpe, P. H. G.; Lee, C. D.; Lowe, G.; Thomas, R. A. S.; Simnor, T.; Bownes, P.; Bidmead, M.; Gandon, L.; Eaton, D.; Palmer, A. L.

    2017-12-01

    A UK multicentre audit to evaluate HDR and PDR brachytherapy has been performed using alanine absolute dosimetry. This is the first national UK audit performing an absolute dose measurement at a clinically relevant distance (20 mm) from the source. It was performed in both INTERLACE (a phase III multicentre trial in cervical cancer) and non-INTERLACE brachytherapy centres treating gynaecological tumours. Forty-seven UK centres (including the National Physical Laboratory) were visited. A simulated line source was generated within each centre’s treatment planning system and dwell times calculated to deliver 10 Gy at 20 mm from the midpoint of the central dwell (representative of Point A of the Manchester system). The line source was delivered in a water-equivalent plastic phantom (Barts Solid Water) encased in blocks of PMMA (polymethyl methacrylate) and charge measured with an ion chamber at 3 positions (120° apart, 20 mm from the source). Absorbed dose was then measured with alanine at the same positions and averaged to reduce source positional uncertainties. Charge was also measured at 50 mm from the source (representative of Point B of the Manchester system). Source types included 46 HDR and PDR 192Ir sources, (7 Flexisource, 24 mHDR-v2, 12 GammaMed HDR Plus, 2 GammaMed PDR Plus, 1 VS2000) and 1 HDR 60Co source, (Co0.A86). Alanine measurements when compared to the centres’ calculated dose showed a mean difference (±SD) of  +1.1% (±1.4%) at 20 mm. Differences were also observed between source types and dose calculation algorithm. Ion chamber measurements demonstrated significant discrepancies between the three holes mainly due to positional variation of the source within the catheter (0.4%-4.9% maximum difference between two holes). This comprehensive audit of absolute dose to water from a simulated line source showed all centres could deliver the prescribed dose to within 5% maximum difference between measurement and calculation.

  5. A comprehensive study on HDR brachytherapy treatments of cervical cancers: using the first Co-60 BEBIG Multisource Unit in Bangladesh.

    Science.gov (United States)

    Malik, Sadiq R; Banu, Parvin A; Rukhsana, Naheed

    2011-06-01

    The report presents an extraordinary synthesis of customer acceptance procedures (CAP), quality assurance tests (QA) in the treatment of cervical cancer patients, using the first Co-60 Multisource Unit ® in Bangladesh. The QA and commissioning required measurements and emergency tests verifying the functional limits of parameters acceptable for the new HDR afterloader. Acceptable limits were: 1) the deviation between specified and measured source strength: ± 3%; 2) the positional accuracy and uniformity: ± 1 mm; 3) the temporal accuracy (i.e. timer error and linearity and end error): ± 1% or 30 sec.; 4) treatment planning system (digitizer and localization software): ± 3% or 1 mm; 5) the distance from line to first dwell position and all the others: 5 mm and 10 mm (± 1 mm). Till February 2011, 47 patients were treated with HDR with more than 140 insertions applied. Amongst them, 12 patients were in stage IIB and IIIB, 22 were postoperative (IA and IB) while the remaining 13 patients were with unknown stage. All the cases with stage IIB and IIIB received concurrent chemo-radiation and brachytherapy. Postoperative patients received EBRT (50 Gy and HDR) according to the institutional protocol. CT scans were completed before HDR-plus planning with a good reproducibility (± 2%) and were documented in repeating the plan for the same set up of a patient. Absorbed dose (Gy) to a point P, at a distance of "r" in centimeters from a source of the Reference Air Kerma Rate (RAKR) has been utilized for the QA of the source, where source strength measurement was accomplished. All methods and analysis applicable to the QA and commissioning of Co-60 have been investigated and systematically analyzed, measured and documented before the treatment of a patient. Studies and safety requirements of this HDR remote afterloader were carried out. Acceptance and the QA were imperative to justify functionality and dependability in delivering the treatment. Implications of these studies

  6. Review: Michael Kerres & Reinhard Keil-Slawik (Hrsg.) (2005). Hochschulen im digitalen Zeitalter: Innovationspotenziale und Strukturwandel

    OpenAIRE

    Hoidn, Sabine

    2008-01-01

    In dem vorliegenden Kongressband setzen sich fünfunddreißig internationale Expertinnen und Experten aus Wissenschaft und Praxis mit Möglichkeiten und Rahmenbedingungen des Einsatzes von Informations- und Kommunikationstechnologien in Hochschulen auseinander. Die Beiträge adressieren aktuelle und zukünftige Herausforderungen, denen sich Hochschulen zu stellen haben, und präsentieren einen bunten Strauß an (bisher) erfolgreichen Projekten und Praxiserfahrungen. Infolge knapper werdender Ressour...

  7. Aussteigen aus dem Rechtsextremismus: Foto-Praxis, bildwissenschaftliche Analyse und Ausstellungsarbeit als Methoden individueller Reflexion und des wissenschaftlichen und (sozialpädagogischen Kompetenzerwerbs

    Directory of Open Access Journals (Sweden)

    Ulrike Pilarczyk

    2013-06-01

    Full Text Available Der Beitrag zeigt die medienpädagogischen und bildwissenschaftlichen Dimensionen eines zeitlich und thematisch gestaffelten Projektes auf. Ausgangspunkt war das in den Jahren 2009/10 von der Organisation EXIT-Deutschland in Berlin mit Aussteigern/-innen aus der rechtsextremen Szene initiierte Fotoprojekt «Lebensbilder». Die im Rahmen biografisch orientierter, medien- und sozialpädagogischer Fallarbeit entstandenen Fotos wurden als Prozess individueller Bilderzeugung und als Mittel zur Reflexion der jeweiligen Lebenssituation der Aussteiger(innen verstanden und eingesetzt. Eine Ausstellung schloss diese erste Phase des hier beschriebenen Projektes ab. Dem Wunsch folgend, die praktischen Erfahrungen aus der Arbeit mit Fotos wissenschaftlich überprüfen zu lassen, wurden in den Jahren 2011 und 2012 mit Studierenden am erziehungswissenschaftlichen Institut der TU Braunschweig die «Lebensbilder» zunächst einer wissenschaftlichen Bildanalyse unterzogen und anschliessend in einem gestalterisch-interpretativen Projekt durch die Studierenden zu einer Ausstellung weiterentwickelt.

  8. Die Werte der Wertvermittler - Berufliches Rollenselbstverständnis und Weltanschauung von Journalistinnen und Journalisten

    Directory of Open Access Journals (Sweden)

    Andy Kaltenbrunner

    2010-09-01

    Full Text Available Der Beitrag analysiert professionelles Selbstverständnis, Weltanschauungen und ethische Überzeugungen von Journalistinnen und Journalisten in Österreich. Auf Basis aktueller Befragungen und Studien wird die Grundstruktur des journalistischen Wertesystems skizziert und der Zusammenhang mit täglicher Berichterstattung. Der Beitrag diskutiert mögliche Konsequenzen für Zukunft des Journalismus und Qualität der Öffentlichkeit. The article focuses on the professional values, political views and ethical beliefs of Austrian journalists. Based on recent surveys we outline the basic structure of the journalistic value system in Austria and the interdependence of these values and actual reporting and we discuss possible consequences for the future of journalism as a profession and for the quality of the public sphere.

  9. Hinkelbeinchen und "little chicken's leg": deutsche und amerikanische Idiome als kommunikative Textsorten-Problematik

    Directory of Open Access Journals (Sweden)

    Martin Wierschin

    1998-12-01

    Full Text Available Als Marin Luther 1522 seine Übersetzung des Neuen Testaments nach der griechischen Edition des Erasmus von Rotterdam abschloß, hatte er dabei zwar mit größtem Sprachgefühl nicht nur dem deutschen, sondem auch dem idiomatischen 'logos' des Griechischen "auf das Maul" gesehen. Aber er mußte in seinem "Sendbrief vom Dolmetschen" 1530 dennoch zugeben, daß selbst er - zusammen mit seinen beiden Assistenten Melanchthon und Aurogallus - sehr oft zwei bis vier Wochen lang nach einem einzigen idiomatisch treffenden Wort zu suchen hatte. Damit wird von einem eminenten Kronzeugen, nämlich vom Schöpfer des protestantischen 'Hausbuches' Lutherbibel und vom eigentlichen Begründer einer einheitlichen deutschen Schrift­ sprache, samt ihrer sprach- und literargeschichtlich wirkungsmächtigen Idiomatik, die Schwierigkeit und Problematik idiomatischer Äquivalenzen und Transferenzen zwischen den Einzelsprachen verbürgt.

  10. Neue Medien in der Lehrerausbildung. Zu angemessenen (und unangemessenen Zielen und Inhalten des Lehramtsstudiums

    Directory of Open Access Journals (Sweden)

    Sigrid Blömeke

    2003-01-01

    Full Text Available In vier Schritten wird dem Verhältnis von Lehrerausbildung und neuen Medien nachgegangen. Zunächst werden grundsätzliche medienpädagogische Aufgaben der Lehrerausbildung herausgearbeitet, bevor das Ausbildungsprofil ihrer ersten und zweiten Phase in den Blick genommen wird. Ausgangspunkt der Theoriebildung sind professions- und institutionentheoretische Ansätze, die auf die neuen Medien bezogen werden; Konkretisierungen erfolgen an Beispielen aus der Germanistik, der Anglistik, der Geschichte und der Mathematik. Anschliessend wird der Erwerb medienpädagogischer Kompetenz durch zukünftige Lehrerinnen und Lehrer von dem Erwerb basaler Medienkompetenz als eines Elements von Allgemeinbildung abgegrenzt. Zum Schluss werden Konsequenzen für die strukturelle Gestaltung der Lehrerausbildung gezogen.

  11. HDR-investigations of check valve closure and resultant water hammer effects

    International Nuclear Information System (INIS)

    Scholl, K.D.

    1983-01-01

    The presented investigations are based on the Loss of Coolant Accident (LOCA). They concentrate on the first blowdown phase after pipe break of a feedwater line. The effect of such a break is moderated by quick closing check valves, by which the loss of coolant water is reduced and optimal post accident conditions are obtained. Unfortunately the closure of the valve can cause high pressure peaks (water hammer effects) in the feedwater system which potentially could produce safety relevant secondary damage. The system loading by these effects has been analysed. The HDR-Investigation-results led to an improvement of the feedwater system safety by verifying damping measures of quick closing check valves. Pressure peaks obtained with undamped valves in the range of 300 bars, are reduced to zero or a few bars above the normal operation pressure in feedwater systems. For the analytical simulation of valve closure the following dominant acting forces are identified: the blowdown flow resistance of the valve cone and the damping pistong force. The analytical description and quantification of the forces depends on blowdown flow and valve friction parameters. These have been evaluated and are presented for practical use. (orig.)

  12. A summary of the Fire Testing Program at the German HDR Test Facility

    International Nuclear Information System (INIS)

    Nowlen, S.P.

    1995-11-01

    This report provides an overview of the fire safety experiments performed under the sponsorship of the German government in the containment building of the decommissioned pilot nuclear power plant known as HDR. This structure is a highly complex, multi-compartment, multi-level building which has been used as the test bed for a wide range of nuclear power plant operation safety experiments. These experiments have included numerous fire tests. Test fire fuel sources have included gas burners, wood cribs, oil pools, nozzle release oil fires, and cable in cable trays. A wide range of ventilation conditions including full natural ventilation, full forced ventilation, and combined natural and forced ventilation have been evaluated. During most of the tests, the fire products mixed freely with the full containment volume. Macro-scale building circulation patterns which were very sensitive to such factors as ventilation configuration were observed and characterized. Testing also included the evaluation of selective area pressurization schemes as a means of smoke control for emergency access and evacuation stairwells

  13. Commissioning and quality assurance procedures for the HDR Valencia skin applicators

    Directory of Open Access Journals (Sweden)

    Domingo Granero

    2016-11-01

    Full Text Available The Valencia applicators (Nucletron, an Elekta company, Elekta AB, Stockholm, Sweden are cup-shaped tungsten applicators with a flattening filter used to collimate the radiation produced by a high-dose-rate (HDR 192 Ir source, and provide a homogeneous absorbed dose at a given depth. This beam quality provides a good option for the treatment of skin lesions at shallow depth (3-4 mm. The user must perform commissioning and periodic testing of these applicators to guarantee the proper and safe delivery of the intended absorbed dose, as recommended in the standards in radiation oncology. In this study, based on AAPM and GEC-ESTRO guidelines for brachytherapy units and our experience, a set of tests for the commissioning and periodic testing of the Valencia applicators is proposed. These include general considerations, verification of the manufacturer documentation and physical integrity, evaluation of the source-to-indexer distance and reproducibility, setting the library plan in the treatment planning system, evaluation of flatness and symmetry, absolute output and percentage depth dose verification, independent calculation of the treatment time, and visual inspection of the applicator before each treatment. For each test, the proposed methodology, equipment, frequency, expected results, and tolerance levels (when applicable are provided.

  14. Monte Carlo characterization of the Gamma-Med Hdr plus Ir-192 brachytherapy source

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, E.; Sosa, M. A.; Gil V, A. [Universidad de Guanajuato, Division de Ciencias e Ingenierias, Av. Insurgentes 2354, 37150 Leon, Guanajuato (Mexico); Monzon, E., E-mail: eric_1985@fisica.ugto.mx [IMSS, Unidad Medica de Alta Especialidad No. 1, Av. Adolfo Lopez Mateos 1813, 37340 Leon, Guanajuato (Mexico)

    2015-10-15

    Full text: The MCNP4C Monte Carlo code was used to simulate the dosimetry around the Gamma-Med Hdr Plus iridium-192 brachytherapy source in both air/vacuum and water environments. Dosimetry data in water was calculated and are presented into an away-along table. All dosimetric quantities recommended by the AAPM Task Group 43 report have been also calculated. These quantities are air kerma strength, dose rate constant, radial dose function and anisotropy function. The obtained data are compared to this source reference data, finding results in good agreement with them. In this study, recommendations of the AAPM TG-43U1 report have been followed and comply with the most recent AAPM and ESTRO physics committee recommendations about Monte Carlo techniques. The data in the present study complement published data and can be used as input in the Tps or as benchmark data to verify the results of the treatment planning systems as well as a means of comparison with other datasets from this source. (Author)

  15. Monte Carlo characterization of the Gamma-Med Hdr plus Ir-192 brachytherapy source

    International Nuclear Information System (INIS)

    Reyes, E.; Sosa, M. A.; Gil V, A.; Monzon, E.

    2015-10-01

    Full text: The MCNP4C Monte Carlo code was used to simulate the dosimetry around the Gamma-Med Hdr Plus iridium-192 brachytherapy source in both air/vacuum and water environments. Dosimetry data in water was calculated and are presented into an away-along table. All dosimetric quantities recommended by the AAPM Task Group 43 report have been also calculated. These quantities are air kerma strength, dose rate constant, radial dose function and anisotropy function. The obtained data are compared to this source reference data, finding results in good agreement with them. In this study, recommendations of the AAPM TG-43U1 report have been followed and comply with the most recent AAPM and ESTRO physics committee recommendations about Monte Carlo techniques. The data in the present study complement published data and can be used as input in the Tps or as benchmark data to verify the results of the treatment planning systems as well as a means of comparison with other datasets from this source. (Author)

  16. An in vivo investigative protocol for HDR prostate brachytherapy using urethral and rectal thermoluminescence dosimetry

    International Nuclear Information System (INIS)

    Toye, Warren; Das, Ram; Kron, Tomas; Franich, Rick; Johnston, Peter; Duchesne, Gillian

    2009-01-01

    Purpose: To develop an in vivo dosimetry based investigative action level relevant for a corrective protocol for HDR brachytherapy boost treatment. Methods and materials: The dose delivered to points within the urethra and rectum was measured using TLD in vivo dosimetry in 56 patients. Comparisons between the urethral and rectal measurements and TPS calculations showed differences, which are related to the relative position of the implant and TLD trains, and allowed shifts of implant position relative to the prostate to be estimated. Results and conclusions: Analysis of rectal dose measurements is consistent with implant movement, which was previously only identified with the urethral data. Shift corrected doses were compared with results from the TPS. Comparison of peak doses to the urethra and rectum has been assessed against the proposed corrective protocol to limit overdosing these critical structures. An initial investigative level of 20% difference between measured and TPS peak dose was established, which corresponds to 1/3 of patients which was practical for the caseload. These patients were assessed resulting in corrective action being applied for one patient. Multiple triggering for selective investigative action is outlined. The use of a single in vivo measurement in the first fraction optimizes patient benefit at acceptable cost.

  17. Intraoperative HDR brachytherapy for rectal cancer using a flexible intraoperative template: standard plans versus individual planning

    International Nuclear Information System (INIS)

    Kolkman-Deurloo, Inger-Karine K.; Nuyttens, Joost J.; Hanssens, Patrick E.J.; Levendag, Peter C.

    2004-01-01

    HDR intraoperative brachytherapy (IOBT) is applied to locally advanced rectal tumors using a 5 mm thick flexible intraoperative template (FIT). To reduce the procedure time, treatment planning is performed using standard plans that neglect the curvature of the FIT. We have calculated the individual treatment plan, based on the real geometry of the FIT, and the dose at clips placed during surgery. A mean treatment dose of 9.55±0.21 Gy was found for the individual plan, compared to the prescribed 10 Gy (P<0.0001). The mean central dose was 10.03±0.10 Gy in the standard plan and 9.20±0.32 Gy in the individual plan (P<0.0001). The mean dose at the corners of the FIT was 10.3 Gy in the standard plan and ranged between 10.3 and 10.5 Gy in the individual plan. In 63% of the clips, the dose was larger than 15.0 Gy, which is equivalent to a gap between the FIT and the target smaller than 5 mm. In 18% of the clips, the dose was smaller than 13.0 Gy indicating that locally the gap was larger than 5 mm. Clinical practice will have to prove if these small dose deviations influence the clinical outcome

  18. SHAM: High-level seismic tests of piping at the HDR

    International Nuclear Information System (INIS)

    Kot, C.A.; Srinivasan, M.G.; Hsieh, B.J.; Malcher, L.; Schrammel, D.; Steinhilber, H.; Costello, J.F.

    1988-01-01

    As part of the second phase of vibrational/earthquake investigations at the HDR (Heissdampfreaktor) Test Facility in Kahl/Main, FRG, high-level simulated seismic tests (SHAM) were performed during April--May 1988 on the VKL (Versuchskreislauf) in-plant piping system with two servohydraulic actuators, each capable of generating 40 tons of force. The purpose of these experiments was to study the behavior of piping subjected to seismic excitation levels that exceed design levels manifold and may result in failure/plastification of pipe supports and pipe elements, and to establish seismic margins for piping and pipe supports. The performance of six different dynamic pipe support systems was compared in these tests and the response, operability, and fragility of dynamic supports and of a typical US gate valve were investigated. Data obtained in the tests are used to validate analysis methods. Very preliminary evaluations lead to the observation that, in general, failures of dynamic supports (in particular snubbers) occur only at load levels that substantially exceed the design capacity. Pipe strains at load levels exceeding the design level threefold are quite small, and even when exceeding the design level eightfold are quite tolerable. Hence, under seismic loading, even at extreme levels and in spite of multiple support failures, pipe failure is unlikely. 5 refs., 16 figs

  19. Multiobjective anatomy-based dose optimization for HDR-brachytherapy with constraint free deterministic algorithms

    International Nuclear Information System (INIS)

    Milickovic, N.; Lahanas, M.; Papagiannopoulou, M.; Zamboglou, N.; Baltas, D.

    2002-01-01

    In high dose rate (HDR) brachytherapy, conventional dose optimization algorithms consider multiple objectives in the form of an aggregate function that transforms the multiobjective problem into a single-objective problem. As a result, there is a loss of information on the available alternative possible solutions. This method assumes that the treatment planner exactly understands the correlation between competing objectives and knows the physical constraints. This knowledge is provided by the Pareto trade-off set obtained by single-objective optimization algorithms with a repeated optimization with different importance vectors. A mapping technique avoids non-feasible solutions with negative dwell weights and allows the use of constraint free gradient-based deterministic algorithms. We compare various such algorithms and methods which could improve their performance. This finally allows us to generate a large number of solutions in a few minutes. We use objectives expressed in terms of dose variances obtained from a few hundred sampling points in the planning target volume (PTV) and in organs at risk (OAR). We compare two- to four-dimensional Pareto fronts obtained with the deterministic algorithms and with a fast-simulated annealing algorithm. For PTV-based objectives, due to the convex objective functions, the obtained solutions are global optimal. If OARs are included, then the solutions found are also global optimal, although local minima may be present as suggested. (author)

  20. Observing and characterizing avalanche activity in the Khumbu Himal, Nepal, using Pleiades and airborne HDR imagery

    Science.gov (United States)

    Thompson, Sarah; Nicholson, Lindsey; Klug, Christoph; Rieg, Lorenzo; Sailer, Rudolf; Bucher, Tilman; Brauchle, Jörg

    2017-04-01

    In the high, steep terrain of the Khumbu Himal, Nepal, snow avalanches play an important role in glacier mass balance, and rockfall supplies much of the rock material that forms the extensive debris covers on glaciers in the region. Information on the frequency and size of gravitational mass movements is helpful for understanding current and future glacier behaviour but currently lacking. In this study we use a combination of high resolution Pleiades optical satellite imagery in conjunction with airborne HDR imagery of slopes in deep shadow or overexposed snow slopes, provided by the German Aerospace Center (DLR) MACS system (see Brauchle et al., MM3.2/GI2.12/GMPV6.4/HS11.13/NH8.9/SSS12.24), to undertake a qualitative observational study of the gravitational processes evident in these sets of imagery. We classify the features found and discuss their likely frequency in the context of previously published research findings. Terrain analysis based upon digital terrain models derived from the same Pleiades imagery is used to investigate the slope angle, degree of confinement, curvature and aspect of observed avalanche and rock fall tracks. This work presents a first overview of the types of gravitational slides affecting glaciers of the Khumbu Himal. Subsequent research efforts will focus on attempting to quantify volumes of mass movement using repeat satellite imagery.

  1. Air-kerma evaluation at the maze entrance of HDR brachytherapy facilities

    International Nuclear Information System (INIS)

    Pujades, M C; Granero, D; Vijande, J; Ballester, F; Perez-Calatayud, J; Papagiannis, P; Siebert, F A

    2014-01-01

    In the absence of procedures for evaluating the design of brachytherapy (BT) facilities for radiation protection purposes, the methodology used for external beam radiotherapy facilities is often adapted. The purpose of this study is to adapt the NCRP 151 methodology for estimating the air-kerma rate at the door in BT facilities. Such methodology was checked against Monte Carlo (MC) techniques using the code Geant4. Five different facility designs were studied for 192 Ir and 60 Co HDR applications to account for several different bunker layouts. For the estimation of the lead thickness needed at the door, the use of transmission data for the real spectra at the door instead of the ones emitted by 192 Ir and 60 Co will reduce the lead thickness by a factor of five for 192 Ir and ten for 60 Co. This will significantly lighten the door and hence simplify construction and operating requirements for all bunkers. The adaptation proposed in this study to estimate the air-kerma rate at the door depends on the complexity of the maze: it provides good results for bunkers with a maze (i.e. similar to those used for linacs for which the NCRP 151 methodology was developed) but fails for less conventional designs. For those facilities, a specific Monte Carlo study is in order for reasons of safety and cost-effectiveness. (paper)

  2. Air-kerma evaluation at the maze entrance of HDR brachytherapy facilities.

    Science.gov (United States)

    Pujades, M C; Granero, D; Vijande, J; Ballester, F; Perez-Calatayud, J; Papagiannis, P; Siebert, F A

    2014-12-01

    In the absence of procedures for evaluating the design of brachytherapy (BT) facilities for radiation protection purposes, the methodology used for external beam radiotherapy facilities is often adapted. The purpose of this study is to adapt the NCRP 151 methodology for estimating the air-kerma rate at the door in BT facilities. Such methodology was checked against Monte Carlo (MC) techniques using the code Geant4. Five different facility designs were studied for (192)Ir and (60)Co HDR applications to account for several different bunker layouts.For the estimation of the lead thickness needed at the door, the use of transmission data for the real spectra at the door instead of the ones emitted by (192)Ir and (60)Co will reduce the lead thickness by a factor of five for (192)Ir and ten for (60)Co. This will significantly lighten the door and hence simplify construction and operating requirements for all bunkers.The adaptation proposed in this study to estimate the air-kerma rate at the door depends on the complexity of the maze: it provides good results for bunkers with a maze (i.e. similar to those used for linacs for which the NCRP 151 methodology was developed) but fails for less conventional designs. For those facilities, a specific Monte Carlo study is in order for reasons of safety and cost-effectiveness.

  3. Characterization of commercial MOSFET detectors and their feasibility for in-vivo HDR brachytherapy.

    Science.gov (United States)

    Phurailatpam, Reena; Upreti, Rituraj; Nojin Paul, Siji; Jamema, Swamidas V; Deshpande, Deepak D

    2016-01-01

    The present study was to investigate the use of MOSFET as an vivo dosimeter for the application of Ir-192 HDR brachytherapy treatments. MOSFET was characterized for dose linearity in the range of 50-1000 cGy, depth dose dependence from 2 to 7 cm, angular dependence. Signal fading was checked for two weeks. Dose linearity was found to be within 2% in the dose range (50-1000 cGy). The response varied within 8.07% for detector-source distance of 2-7 cm. The response of MOSFET with the epoxy side facing the source (0 degree) is the highest and the lowest response was observed at 90 and 270 degrees. Signal was stable during the study period. The detector showed high dose linearity and insignificant fading. But due to angular and depth dependence, care should be taken and corrections must be applied for clinical dosimetry. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  4. Clinical implementation of a quality assurance program in HDR brachytherapy by in vivo dosimetry with diodes

    International Nuclear Information System (INIS)

    Alecu, R.; Feldmeier, J.J.; Court, W.S.; Alecu, M.; Orton, C.G.

    1996-01-01

    Despite the possibilities of in vivo dosimetry with diodes (e.g. control of dose to organs at risk, recorded confirmational measurements of the dose actually delivered, check of the whole treatment chain, avoidance of misadministrations, etc.) and the fact that it has proven to be very useful as part of a departmental QA program in external beam therapy, few attempts to implement it for HDR brachytherapy procedures have been reported. The reason for this is probably that there are significant technical challenges that must be met prior to its clinical use. The purpose of this study is to investigate the practicability and usefulness of dose measurements for brachytherapy patients in daily clinical practice. In our clinic a high precision patient dosimetry method has been developed, based on the use of silicon diodes. First, calibration factors have been determined under 'reference' irradiation conditions. Secondly, correction factors have been evaluated for situations deviating from the reference conditions, i.e. for different distances from the implanted sources, tissue heterogeneities, presence of different type of applicators, etc. For certain intracavitary, interstitial and surface mold applications this procedure has proven to be sufficiently accurate to allow dose determinations with diodes to be in good agreement with the expected values, i.e. calculated by the treatment planning system (VariSource unit) and checked by ion chamber measurements. The results of in vivo measurements are discussed along with the possibilities and limitations of the employed techniques

  5. High-level seismic tests of piping at the HDR [Heissdampfreaktor

    International Nuclear Information System (INIS)

    Kot, C.A.; Srinivasan, M.G.; Hsieh, B.J.; Costello, J.F.

    1989-01-01

    As part of the second-phase testing at the Heissdampfreaktor (HDR) Test Facility in Kahl/Main, Federal Republic of Germany (FRG), high-level seismic experiments, designated SHAM, were performed on an in-plant piping system during the period of 19 April to 27 May 1988. The objectives of the SHAM experiments were to (1) study the response of piping subjected to seismic excitation levels that exceed design levels manifold and which may result in failure/plastification of pipe supports and pipe elements; (2) provide data for the validation of linear and nonlinear pipe response analyses; (3) compare and evaluate, under identical loading conditions, the performance of various dynamic support system, ranging from very flexible to very stiff support configurations; (4) establish seismic margins for piping, dynamic pipe supports, and pipe anchorages; and (5) investigate the response, operability, and fragility of dynamic supports and of a typical US gate valve under extreme levels of seismic excitation. A brief description of the SHAM tests is provided, followed by highlights of the test results that are given primarily in the form of maximum response values. Also presented are very limited comparisons of experimental data and pretest analytical predictions. 6 refs., 8 figs

  6. Full-scale HDR blowdown experiments as a tool for investigating dynamic fluid-structural coupling

    International Nuclear Information System (INIS)

    Krieg, R.; Schlechtendahl, E.G.; Scholl, K.-H.; Schumann, U.

    1977-01-01

    As an answer to rigorous safety requirements in reactor technology an experimental-theoretical program has been established to investigate safety-relevant mechanical aspects of LWR-blowdown accidents. Part of the program are several full-scale blowdown experiments which will be performed in the former HDR-reactor. As the conceptional study confirms, the primary goal is to find out, how big the safety margins of present LWR's in the case of a blowdown actually are, rather than simply to show that essential parts of the reactor will withstand such an accident. However, to determine the safety margins, the physical phenomena involved in the blowdown process must be understood and appropriate wave of description must be found. Therefore the experimental program is accompanied by the development of theoretical models and computer codes. A survey is given over existing methods for coupled fluid structural dynamics. The following approaches are used: - Specific finite difference-code for integrated treatment of both fluid and structure in 3D-geometry using the fast cyclic reduction scheme for solving Poisson's equation. - Modification of mass and stiffness matrices of FEM-models for shell dynamics by reducing the 3D incompressible fluid problem to 2D with the boundary integral equation method. This presently developed method has the capacity to deal with general problems in fluid-structural coupling. (Auth.)

  7. Large scale fire experiments in the HDR containment as a basis for fire code development

    International Nuclear Information System (INIS)

    Hosser, D.; Dobbernack, R.

    1993-01-01

    Between 1984 and 1991 7 different series of large scale fire experiments and related numerical and theoretical investigations have been performed in the containment of a high pressure reactor in Germany (known as HDR plant). The experimental part included: gas burner tests for checking the containment behaviour; naturally ventilated fires with wood cribs; naturally and forced ventilated oil pool fires; naturally and forced ventilated cable fires. Many results of the oil pool and cable fires can directly be applied to predict the impact of real fires at different locations in a containment on mechanical or structural components as well as on plant personnel. But the main advantage of the measurements and observations was to serve as a basis for fire code development and validation. Different types of fire codes have been used to predict in advance or evaluate afterwards the test results: zone models for single room and multiple room configurations; system codes for multiple room configurations; field models for complex single room configurations. Finally, there exist codes of varying degree of specialization which have proven their power and sufficient exactness to predict fire effects as a basis for optimum fire protection design. (author)

  8. Studie: Die Generation Y und deren organisatorische Implikationen

    OpenAIRE

    Klein, Helmut

    2016-01-01

    Die vorliegende Studie betrifft die Gen. Y und ihre spezifischen Anforderungen an die Unternehmensorganisation. Im Ergebnis einer durchgeführten Befragung ist festzuhalten, dass die Gen. Y die Kernkompetenzen eines Managers verstärkt einfordert und eine hohe Betreuungsintensität verlangt. Dies hat Auswirkungen auf die Führungsspanne, Planung und Kontrolle von Aufgaben, die Gestaltung der vertikalen und horizontalen Prozesse sowie die Zusammensetzung von Teamarbeitsformen. Projektarbeit sowie ...

  9. Beginn und Dosisanpassung einer intensivierten konventionellen Insulintherapie (ICT beim Erwachsenen

    Directory of Open Access Journals (Sweden)

    Lohr R

    2012-01-01

    Full Text Available Eine intensivierte Insulintherapie (ICT ist die Behandlung der Wahl bei Diabetes mellitus Typ 1 und auch bei vielen Menschen mit insulinpflichtigem Typ-2-Diabetes. Bei Therapiebeginn müssen individuell Insuline ausgewählt und die richtige Dosierung festgelegt werden. Im weiteren Verlauf ist dann die Anpassung der Insulintherapie an besondere Alltagssituationen wie Sport oder akute Erkrankungen vorrangig. Eine gute Patientenschulung und eine gute Zusammenarbeit zwischen Betroffenem und Behandlerteam sind entscheidend, um diese komplizierte Therapie erfolgreich umzusetzen.

  10. Informationsdesign von Bildungsportalen : Struktur und Aufbau netzbasierter Bildungsressourcen

    OpenAIRE

    Panke, Stefanie

    2009-01-01

    Sowohl Unternehmen als auch Bildungseinrichtungen, Verlage, politische Organisationen, Verbände, Interessengruppen und Privatpersonen nutzen das Internet, um Informationen zu verbreiten. Die Varianz an Akteuren, Adressaten und Botschaften spiegelt sich wider in einem wachsenden Spektrum an Web-Genres: Suchmaschine, E-Commerce-Auftritt und Online-Zeitung teilen sich die Aufmerksamkeit der Leser unter anderem mit privaten Weblogs und kollaborativen Wissenssammlungen wie der Enzyklopädie Wikiped...

  11. Molekulare Systematik und Evolution der Spezies der Familie Arthrodermataceae (Dermatophyten)

    OpenAIRE

    Gräser, Yvonne

    2002-01-01

    Dermatophyten sind keratinophile Pilze, d.h. sie besiedeln und infizieren die Haut und ihre Anhangsgebilde (Haare, Nägel) bei Mensch und Tier. Die derzeit häufigsten durch Dermatophyten hervorgerufenen Infektionen sind die Onychomykose, Tinea pedis, Tinea capitis und Tinea corporis. Da Antimykotika nicht bei alle Erregern von Dermatophytosen gleich wirksam sind, sollte im Vordergrund einer Behandlung zunächst die korrekte Erregerdifferenzierung stehen. Konventionell erfolgt diese Differenzier...

  12. Spurenstoffuntersuchungen zur Bildung und Ausbreitung von Wassermassen im subpolaren Nordatlantik

    OpenAIRE

    Hildebrandt, Hauke

    2001-01-01

    In der vorliegenden Arbeit wurde ein umfangreicher Spurenstoffdatensatz aus dem subpolaren Nordatlantik erstellt und ausgewertet, der Tritium-, Helium- und Neon- sowie O-18-Messungen umfaßt. Das Hauptaugenmerk galt dabei der Bildung und Ausbreitung der tiefen Wassermassen und deren Variabilität auf Zeitskalen von einigen Jahren. Anhand von Tracermittelwerten, die mit Hilfe eines optimierten Interpolationsverfahrens gewonnen wurden, konnte gezeigt werden, daß die konvektive Neubildung de...

  13. Aufgabenbezogene Differenzierung und Entwicklung des verbalen Selbstkonzepts im Anfangsunterricht

    OpenAIRE

    Lipowsky, Frank; Kastens, Claudia; Lotz, Miriam; Faust, Gabriele

    2011-01-01

    Die vorliegende Studie untersucht, wie sich aufgabenbezogene Differenzierung im Deutschunterricht auf die Entwicklung des verbalen Selbstkonzepts von Erst- und Zweitklässlern (Lesen und Schreiben) auswirkt. Die untersuchte Stichprobe setzt sich aus 735 Schülern des ersten Schuljahres zusammen, die 38 Klassen an staatlichen und privaten Grundschulen besuchen und die bis zum Ende des zweiten Schuljahres in ihrer Entwicklung untersucht wurden. Die Ergebnisse zeigen sowohl einen indirekten als au...

  14. Märkte und Macht der Internetkonzerne: Konzentration - Konkurrenz - Innovationsstrategien

    OpenAIRE

    Dolata, Ulrich

    2014-01-01

    In diesem Aufsatz, der auf einer systematischen Auswertung von Geschäftsberichten, Dokumenten, verfügbarem empirischem Material, Literatur und Presseberichten basiert, werden die Konzentrationsprozesse auf den wesentlichen Internetmärkten so- wie die Expansions- und Innovationsstrategien der fünf führenden Konzerne Google, Facebook, Apple, Amazon und Microsoft analysiert. Die Befunde, die der Text vorstellt, sind von einer Dezentralisierung der Markt- und Demokratisierung der Innovationsproze...

  15. Arbeitszeiten von Professorinnen und Professoren in Deutschland 2016

    OpenAIRE

    Weihs, Claus; Hernández Rodríguez, Tanja; Doeckel, Maximilian; Marty, Christoph; Wormer, Holger

    2018-01-01

    In dieser Studie werden belastbare Prognoseintervalle der wöchentlichen Gesamtarbeitszeit von Universitätsprofessorinnen und -professoren aus Daten einer Umfrage aus dem Jahre 2016 und a-priori Informationen aus früheren Studien bestimmt. Neben der Gesamtarbeitszeit werden auch Teilarbeitszeiten zum Beispiel für Lehre und Forschung ermittelt. Die Ergebnisse von frequentistischer und Bayesianischer Analyse werden verglichen. Aus den gültigen Fragebögen von aktiven Vollzeit arbeitenden Universi...

  16. Umfrageforschung: Entscheidungsgrundlage für Politik und Wissenschaft

    OpenAIRE

    2011-01-01

    "Der vorliegende Tagungsband dokumentiert die Beiträge der wissenschaftlichen Tagung 'Umfrageforschung - Entscheidungsgrundlage für Politik und Wissenschaft', die am 30. Juni und 1. Juli 2011 gemeinsam vom Statistischen Bundesamt, dem ADM Arbeitskreis Deutscher Markt- und Sozialforschungsinstitute e.V. und der Arbeitsgemeinschaft Sozialwissenschaftlicher Institute e.V. (ASI) in Wiesbaden durchgeführt wurde." (Autorenreferat). Inhaltsverzeichnis: Christian König, Matthias Stahl, Erich Wiegand:...

  17. Reputationsorientiertes Themen- und Issues-Management : Konzeption, Regelbetrieb, Weiterentwicklung

    OpenAIRE

    Fahrenbach, Christian

    2011-01-01

    Die Dissertation untersucht, wie Organisationen ein reputationsorientiertes Themen- und Issues-Management aufbauen, betreiben und weiterentwickeln können. Dazu wird das operative Modell des Issues Managements mit dem strategischen Zielkonstrukt Reputation verbunden. Zu Beginn der Arbeit beschreiben zwei Theorie-Kapitel ausführlich Relevanz und die Steuerung von Reputation und im Issues Management. Auf dieser Basis wird ein praxisorientiertes integriertes Modell entwickelt. Es beschreibt da...

  18. Die Landschaft in der Geschichte, in der Kultur, in der Kunts und in der Stadtplanung: theoretische Annahmen und Erfahrungen

    Directory of Open Access Journals (Sweden)

    Mario Coletta

    2013-01-01

    Full Text Available Das vorgeschlagene Thema hat das Ziel, dem Konzept der Landschaft eine neue Definition zu geben. Sie soll nicht nur als Umhuellung des staedtischen und laendlichen Territoriums gesehen werden, das besiedelt und produktiv ist, zivilisiet und natuerlich belassen, sondern wie ein lebender Koerper, wenn auch nicht bei bester Gesundheit, der trotz seines Altes noch den vielen Veraenderungen standhaelt. Veraenderungen durch Naturkatatrophen herforgerufen, und besonders durch die vielen Wunden die das Werk der Menschen ihm zugefuegt hat. Als lebendes Wesen leidet die Landschaft und freut sich in guten Zeiten, kleidert sich lieber arm, aber schicklich, als reich und anmassend: Zeuge guter und schlechter Haushaltsfuehrung, jedoch Erbe einer Geschichte die sie erhebt, die Geschichte, Literatur, Ausdruecke der Kunts, kreative Planung beseelt hat. All das ist zusammengefasst in dem Wort "Kultur", die es verdient hat, erworben zu werden, vertieft und den naeschsten Generationen weitergegeben, moeglicherweise noch bereichert von dem, das die heutige Kultur ausarbeiten kann, auch auf dem Weg der Stadtplanung.

  19. Game-Review: Trilogie Mass Effect 1, 2 und 3

    Directory of Open Access Journals (Sweden)

    Karl H. Stingeder

    2013-03-01

    Full Text Available Karl Stingeder hat als Spieletester die Science Fiction Trilogie Mass Effect (1,2 und 3 rezensiert. Er berichtet von der inneren Vielfalt und dem spannenden Gameplay. Tauchen Sie ein in eine Welt, die ihnen eine lange Spielzeit garantiert und genießen Sie die Pracht dieser Kunstwerke.

  20. Klare Regeln - effiziente und effektive FMEA-Anwendung

    OpenAIRE

    Schloske, Alexander

    2014-01-01

    Der Vortrag beschreibt klare Regeln zur effizienten und effektiven FMEA-Anwendung. - Denkmodelle für die verschiedenen FMEA-Arten (System-FMEA, Konstruktions-FMEA, Prozess-FMEA) - Anwendungsbereiche und FMEA-Planung - Strukturierung von FMEAs - Funktionen, Produktmerkmale und Prozessmerkmale - Risikoanalyse - Maßnahmendefinition - Risikobewertung - Präsentation von FMEAs - FMEA als "lebendes Dokument".

  1. Der Heilige Geist und die Realisierung des Glaubens in der ...

    African Journals Online (AJOL)

    29. Juli 2016 ... der Sprache bis hin zu den kulturellen und religiösen. Zeichensystemen, muss von dem Einzelnen empfangen und angeeignet werden. Kommunikation, auch die religiöse, verwirklicht sich ausschließlich in der Spannung von geschichtlicher Abhängigkeit und Transformation der überlieferten Gehalte im ...

  2. Die Inquisition und ihre Wahrnehmung im Alten Reich

    Directory of Open Access Journals (Sweden)

    Alexandra Kohlhöfer

    2013-01-01

    Full Text Available Rezension von: Tribunal der Barbaren? Deutschland und die Inquisition in der Frühen Neuzeit, hg. von Albrecht Burckhardt und Gerd Schwerhoff unter Mitwirkung von Dieter R. Bauer (Konflikte und Kultur – Historische Perspektiven 25, Konstanz, München: UVK-Verl.-Ges. 2012, 450 S., ISBN 978-3-86764-371-9

  3. Biologisch-dynamische Forschung zwischen "wissenschaftlicher Weltsicht" und "Ideologie"

    OpenAIRE

    Eysel, Georg

    2002-01-01

    Der Beitrag zeigt den Konflikt zwischen "wertefreier" Wissenschaft und "ganzheitlicher" Forschung auf. Ein Zusammenspiel bio-dynamischer Forschung und der Anthroposophie mit anderen Disziplinen könnte einen Beitrag zu einem neuen Wissenschaftsbegriff mit umfassender Weltanschauung leisten. Dialog, Verständnis, Toleranz, Offenheit, kritisches Hinterfragen und Mut zur sinnvollen Anpassung sind dafür notwendige Schritte.

  4. Anmerkungen zur Methode einer theologischen Wirtschafts- und Sozialethik

    OpenAIRE

    Mack, Elke

    2002-01-01

    "Moderne theologische Wirtschafts- und Sozialethik sollte im Rahmen der wissenschaftstheoretischen Schritte 'Analyse, Synthese, Operationalisierung' erfolgen. Die christliche Wirtschafts- und Sozialethik erfüllt bei diesem Zuschnitt den Anspruch einer modernen theologischen Gerechtigkeitstheorie, die erstens ihr hermeneutisches Vorverständnis hinreichend klärt und analytisch an Problemstellungen herangeht, die zweitens auf der Basis eines hypothetischen Konsenses aller Betroffener zu normativ...

  5. Die Verbesserung von Tiergesundheit und Wohlergehen der Tiere in Maststierbetrieben

    DEFF Research Database (Denmark)

    Kirchner, Marlene

    2015-01-01

    europäisches Forschungsprojekt, das die Integration des Tierwohlergehens in die Nahrungsqualitätskette zum Thema hatte. Das Projekt trug den Bedenken der Gesellschaft und Wünschen des Marktes Rechnung und entwickelte zuverlässige Systeme für die Kontrolle landwirtschaftlicher Betriebe und die...

  6. Konflikt und Kooperation bei der Wassernutzung in Mittelasien

    NARCIS (Netherlands)

    Wegerich, K.

    2009-01-01

    In Mittelasien sind Mensch, Natur und Wirtschaft auf das Wasser zweier Flusssysteme angewiesen: des Syr Darja im Norden und des Amu Darja im Süden. Beide Ströme sind in hohem Maße zur Stromgewinnung und landwirtschaftlichen Bewässerung erschlossen. Die Nutzung des Wassers birgt erhebliches Potential

  7. Blogs und Journalismus – Konkurrenz oder Ergänzung? – Das Verhältnis von Blogs und Journalismus in Deutschland

    Directory of Open Access Journals (Sweden)

    Saskia Leidinger

    2015-12-01

    Full Text Available Mit der Frage, ob „Blogs und Journalismus - Konkurrenz oder Ergänzung“ sind, beschäftigt sich Saskia Leidinger in dem gleichnamigen Essay über „das Verhältnis von Blogs und Journalismus in Deutschland“. In vergleichender Perspektive richtet die Autorin ihr Hauptaugenmerk auf die Arbeitsweise sowie die Eigen- und Fremdwahrnehmung von Bloggern und Journalisten, um Gemeinsamkeiten und Unterschiede herauszustellen und ihre je spezifische Funktion innerhalb der der heutigen Informationsgesellschaft einzugrenzen.

  8. Rasterelektronenmikroskopische und immunhistochemische Untersuchungen am Eileiter vom Schwein während Zyklus und Trächtigkeit

    OpenAIRE

    Mayer, Judith

    2008-01-01

    In der vorliegenden Arbeit wurden zum einen mit Hilfe des Rasterelektronenmikroskops die morphologischen Veränderungen des Eileiterepithels und zum anderen die Expression hypophysärer wachstums- und proliferationsfördernder Hormone und ihrer Rezeptoren immunhistochemisch und mit der Reverse Transkriptase (RT)-PCR sowohl im Verlauf des Zyklus als auch der Trächtigkeit analysiert. Hierfür wurden, von 24 Schweinen der Deutschen Landrasse, die drei Abschnitte des Eileiters (Infundibulum, Ampulle,...

  9. Krieg und Literatur War and Literature

    Directory of Open Access Journals (Sweden)

    Elfi N. Theis

    2007-03-01

    Full Text Available Schreiben gegen Krieg und Gewalt heißt der Band 19 der Schriften-Reihe des Erich-Maria-Remarque-Archivs, in dem es um Ingeborg Bachmann und die deutschsprachige Literatur 1945-1980 geht. Der Band enthält die Beiträge zu einem Symposion, das am 14.-15. Januar 2005 an der Universität Nottingham stattgefunden hat. Im Mittelpunkt stand die Frage, welche Strategien im Umgang mit Nationalsozialismus, Holocaust, zweitem Weltkrieg, Kaltem Krieg oder Vietnamkrieg und auch dem deutschen Kolonialismus bei Bachmann und anderen deutschsprachigen Autoren zu finden sind. Anlass zur Tagung war die in Wien und Salzburg konzipierte Ausstellung Schreiben gegen den Krieg: Ingeborg Bachmann, 1926-1973. In insgesamt dreizehn Beiträgen wird im vorliegenden Band die literarische Auseinandersetzung mit dem Thema Gewalt und Krieg beleuchtet.Volume 19 of the series published by the Erich-Maria-Remarque Archive is entitled “Writing against War and Violence” (“Schreiben gegen Krieg und Gewalt” and approaches Ingeborg Bachmann and German language literature from 1945 to 1980. The volume contains contributions based on a symposium that took place at the University of Nottingham on January 14-15, 2005. Central to the symposium was the question as to which strategies Bachmann and other German language authors utilized in their approach to National Socialism, the Holocaust, the Second World War, the Cold War, or the Vietnam War, as well as German colonialism. The impetus for the conference was the exhibition Writing Against the War: Ingeborg Bachmann, 1926-1973 conceived in Vienna and Salzburg. In the volume at hand, thirteen contributions in total illuminate literary confrontations with the themes of war and violence.

  10. [Geisteswissenschaften und Publizistik im Baltikum des 19. und frühen 20. Jahrhunderts] / Gert von Pistohlkors

    Index Scriptorium Estoniae

    Pistohlkors, Gert von, 1935-

    2013-01-01

    Arvustus: Geisteswissenschaften und Publizistik im Baltikum des 19. und frühen 20. Jahrhunderts. Hrsg. von Norbert Angermann, Wilhelm Lenz und Konrad Maier. (Schriften der Baltischen Historischen Kommission, Bd. 17; Baltische Biographische Forschungen, Bd. 1.) Lit. Münster 2011

  11. Kommunikationsprobleme zwischen deutschen Expatriates und Chinesen in der wirtschaftlichen Zusammenarbeit -- Empirische Erfahrungen und Analyse der Einflußfaktoren

    OpenAIRE

    Shi, Hongxia

    2003-01-01

    Die vorliegende Arbeit untersucht die empirischen Erfahrungen und die Einflußfaktoren der Kommunikationsprobleme der deutschen Expatriates und Chinesen in der wirtschaftlichen Zusammenarbeit. Die Untersuchung basiert auf einem Datenmaterial, das aus 86 Interviewgesprächen mit Betroffenen besteht. Zentrale Fragestellungen der vorliegenden Arbeit sind: 1. Mit welchen Kommunikationsproblemen werden die befragten deutschen Expatriates und Chinesen in ihrer interkulturellen Kommunikation miteinand...

  12. [Glanz und Elend - Mythos und Wirklichkeit der Herrenhäuser im Baltikum] / Karsten Brüggemann

    Index Scriptorium Estoniae

    Brüggemann, Karsten, 1965-

    2014-01-01

    Arvustus: Glanz und Elend - Mythos und Wirklichkeit der Herrenhäuser im Baltikum. Hrsg. von Ilse von zur Mühlen im Auftrag der Carl-Schirren-Gesellschaft e.V. und des Ostpreußischen Landesmuseums Lüneburg. Kunstverlag Josef Fink. Lindenberg im Allgäu 2012

  13. Wie schneiden Sie ab?: Studie über Kontroll- und Prüfungsaktivitäten bei mittelgrossen Unternehmen, Spitälern und Hochschulen in der Schweiz

    OpenAIRE

    Ruud, T F; Isufi, S; Friebe, P; Stebler, W; Seheri, F; Emmenegger, M

    2008-01-01

    Kontroll- und Prüfungsaktivitäten unterstützen den Verwaltungsrat und die Geschäftsleitung bei der Steuerung und Kontrolle des Unternehmens. Bei mittelgrossen Unternehmen ist aufgrund der begrenzten personellen und finanziellen Ressourcen ein effektiver und effizienter Einsatz dieser Aktivitäten unerlässlich. Auch bei Spitälern und Hochschulen gewinnen Kontroll- und Prüfungsaktivitäten infolge erhöhter Wettbewerbsintensität und steigenden Kostendrucks sowie zunehmender Unabhängigkeit diese...

  14. Bewältigungsstrategien der Oberwalliser Primarlehrpersonen und Massnahmen der Gesundheitsförderung an Oberwalliser Primarschulen bei Stress und Burnout

    OpenAIRE

    Imhof, Barbara; Mattig, Astrid

    2009-01-01

    Die vorliegende Studie befasst sich mit der Gesundheitsförderung bei Stress und Burnout an den Oberwalliser Primarschulen und der Bewältigungsstrategien der Oberwalliser Primarlehrpersonen bei Stress und Burnout. Der theoretische Teil befasst sich mit Stress und Burnout und der Bewältigung von Stress und Burnout. Verschiedene Aspekte des Lehrerberufs werden näher angeschaut und es werden mögliche Massnahmen der Gesundheitsförderung bei Stress und Burnout aufgeführt. Die Untersuchung zeigt, da...

  15. Soziologische Wissenskulturen zwischen individualisierter Inspiration und prozeduraler Legitimation. Zur Entwicklung qualitativer und interpretativer Sozialforschung in der deutschen und französischen Soziologie seit den 1960er Jahren

    Directory of Open Access Journals (Sweden)

    Reiner Keller

    2016-01-01

    Full Text Available Wie wissen Soziologinnen und Soziologen, was sie wissen? Trotz der Internationalisierung der Soziologie bestehen nach wie vor starke sprachräumliche Unterschiede in der soziologischen Wissensproduktion, in eingesetzten Theorien, Methoden und Fragestellungen. Der nachfolgende Beitrag erläutert die Entwicklung und Ausprägung der Unterschiedlichkeit soziologischer Wissenskulturen im Hinblick auf den Einsatz qualitativer bzw. interpretativer Ansätze seit den 1960er Jahren in Deutschland und Frankreich. Er stützt sich auf ein von uns 2012-2014 geleitetes Forschungsprojekt und dessen empirische Grundlagen: Dokumentenanalysen und Interviews. Wissenskulturen werden als die Arten und Weisen der Produktion und Legitimation von (hier: soziologischem Wissen verstanden. Diesbezüglich lässt sich von der Erkenntnisproduktion als dem zentralen Handlungsproblem soziologischen Forschens sprechen. Während für die französischsprachige Soziologie diagnostisch von einer Lösung dieses Erkenntnisproblems durch die den Forschenden zugeschriebenen Kompetenzen und Inspirationen ausgegangen werden kann, schiebt sich im deutschsprachigen Raume eine prozedurale Legitimation durch Verfahren in den Vordergrund. Der Beitrag rekonstruiert exemplarisch die Ausgangssituation dieser Entwicklungen um die Wende zu den 1960er Jahren und bettet sie in die weitere Entfaltung der jeweiligen Soziologien ein. Er will damit zur gegenwärtigen Entwicklung einer reflexiven Soziologie beitragen. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1601145

  16. "Tabula Sinvs Venetici" von W. Barents und ihre Geschichtilische und Geographische Bedeutung

    Directory of Open Access Journals (Sweden)

    Mithad Kozličić

    1999-06-01

    Full Text Available In der wissenschaftlichen Literatur sind zwei Varianten der Seekarte der Adria vom niederländischen Seefahrer und Polarforscher Willem Barents (1550-1597 bekannt. Die erste, in diesem Aufsatz als K-1 bezeichnete Karte, wurde in Amsterdam 1595 hergestellt und gedruckt. Sie hatte anfänglich eine praktisch-navigatorische Funktion. Die zweite, K-2, ins Jahr 1595 datierte (1637-1662 Karte, wurde als geostrategische Karte der Adria und der südlichen Teile Europas ausgenützt. An den adriatischen Nordküsten, besonders in ihrem Hinterland, geschahen mit dem Durchbruch der Türken seit der Hälfte des 16. Jahrhunderts wichtige militärische und politische Änderungen. In den “Atlanten” des Niederländers Jan (Johann; Joannes Janssonius (1588-1664 fehlte gerade solch eine Karte, die auch mehrmals in Amsterdam gedruckt wurde, aber zwischen 1637 und 1662. Die K-1 von Barents, deren Druckplatte Janssonius zur Verfügung hatte, konnte diese Funktion befriedigen. Deswegen machte Janssonius nur die nötigen dem darstellenden Standard der ersten Hälfte des 17. Jahrhunderts entsprechenden Änderungen, und als solche wurde sie gedruckt. Die K-2 verlor ihre ursprüngliche praktisch-navigatorische Funktion und wurde eine Karte von geostrategischer Bedeutung. Mit diesen Grundfragen befaßt sich dieser Aufsatz.

  17. [Vilis Kolms. Das Rigaer Gesangbuch und die kirchenordnung von 1530]/ Dennis Hortmuth

    Index Scriptorium Estoniae

    Hormuth, Dennis

    2012-01-01

    Arvustus: .Vilis Kolms. Das Rigaer Gesangbuch und die kirchenordnung von 1530. In: Die baltischen Lande im Zeitalter der Reformation und Konfessionaliesierung. Livland, Estland, Ösel, Ingermanland, Kurland und Lettgallen. Stadt, Land und Konfession 1500-1721. Teil 2 (=Katholisches Leben und Kirchenreform im Zeitalter der Glaubensspaltung 70). Münster, 2010. S. 175-190

  18. Diffuser Haarausfall und klinische Endokrinologie: Neue Erkenntnisse

    Directory of Open Access Journals (Sweden)

    Liptak J

    2013-01-01

    Full Text Available Diffuser Haarausfall ist ein häufiges Krankheitsbild in der täglichen Praxis, dessen Diagnostik allerdings oft eine Herausforderung darstellt. In den vergangenen 10 Jahren wurden große Fortschritte in der Erforschung der Effekte diverser Hormone erzielt. In murinen Haarfollikeln wird Corticoliberin (Corticotropin-releasing Hormone [CRH] mit einem Peak in der Anagenphase (Wachstumsphase exprimiert. Ein stressinduziert erhöhter CRH-Spiegel kann durch Aktivierung von Mastzellen zu erhöhtem Haarverlust führen. Melatonin wird ebenfalls im Haarfollikel exprimiert und wirkt dort auf unterschiedliche Rezeptoren. Besonders der nukleäre Retinoic Acid Receptor-(RAR- Related Orphan-Receptor alpha (RORα scheint regulatorisch auf haarzyklusabhängige Prozesse zu wirken und wird auch abhängig vom Haarzyklus exprimiert. Melatonin greift zudem in androgen- und östrogenvermittelte Signaltransduktionswege ein. Eine topische Anwendung von Melatonin kann zu einer Zunahme der Anagenhaare führen. Auch Leptin wird im Haarfollikel exprimiert und beeinflusst Haarwachstum und Hautregeneration durch Aktivierung von STAT3. Bei Mäusen konnte durch Leptin die Anagenphase induziert werden. Über den Zusammenhang zwischen androgenetischer Alopezie und Metabolischem Syndrom wurden zahlreiche widersprüchliche Daten veröffentlicht. Zuletzt wies eine große koreanische Studie eine positive Assoziation der Krankheitsbilder bei Frauen nach, jedoch nicht bei Männern. Prolaktin induziert den verfrühten Übergang zur Katagenphase, senkt die Proliferationsrate der Keratinozyten im Haarfollikel und steigert deren Apoptoserate. Eine zu Haarausfall führende Hyperprolaktinämie kann unter anderem durch diverse Medikamente, insbesondere typische und atypische Neuroleptika, hervorgerufen werden. Zahlreiche Studien an Mäusen konnten belegen, dass der Vitamin-D-Rezeptor (VDR eng mit dem Haarwachstum assoziiert ist. Dieser scheint den Haarzyklus unabhängig von seinen Liganden

  19. Big Data in kleinen und mittleren Unternehmen: Eine empirische Bestandsaufnahme

    OpenAIRE

    Vossen, Gottfried; Lechtenbörger, Jens; Fekete, David

    2015-01-01

    Dieser Bericht untersucht das Potential von Big Data in und für kleine und mittlere Unternehmen (KMU). Dafür werden mittels einer Umfrage, Fokus-Interviews und zusätzlichen Recherchen die Potentiale und Herausforderungen bei Big Data untersucht, welche für KMU zu Tragen kommen. Der Begriff Big Data selbst wird genauer betrachtet und es wird erklärt, welche Dimensionen abseits schierer Größe ebenfalls dazu zählen, wie etwa Vielfalt oder Schnelligkeit der Daten. Weiter wird mit eingängigen Prax...

  20. Von Nischen und Infrastrukturen - Herausforderungen und neue Ansätze politischer Technologien

    Directory of Open Access Journals (Sweden)

    Felix Stalder

    2011-06-01

    Full Text Available Neue Technologien aus dem aktivistischen Umfeld bieten radikale Alternativen zu kultureller Nischenbildung und zentralisierten Web 2.0-Infrastrukturen. Die sozialen und politischen Realitäten der Digitalisierung und Vernetzung sind heute von zwei konstitutiven, aber grundsätzlich unterschiedlichen, ja teilweise sogar entgegengesetzten Dynamiken geprägt. Beide stellen den Medienaktivismus vor neue Herausforderungen. Zum einen können wir ein Aufblühen neuer kultureller Nischen und horizontaler Organisationsformen beobachten. Zum anderen erleben wir gleichzeitig eine enorme Zentralisierung und Konzentration auf der Ebene der Plattformen, welche einen grossen Teil der infrastrukturellen Grundlage des Wachstum der Nischen und neuen Kooperationsmuster darstellen. Nachdem der Aufbau alternativer Infrastrukturen – Zeitschriften, TV Kanäle und Internetplattformen – in den ersten 30 Jahren medienaktivistischer Projekte eine grosse Rolle gespielt hat (Stalder 2008 sind diese Fragen in den letzten 10 Jahren etwas in den Hintergrund getreten. Denn die Komplexität der Infrastrukturen nahm stetig zu, was es immer aufwendiger machte, sie zu betreiben und die neuen, offene Plattformen, wie sie für Web 2.0 typisch sind, stellten allen - scheinbar ohne Einschränkungen - mächtige Werkzeuge zu Verfügung. Warum eine eigene Plattform betreiben, wenn grosse professionelle Anbieter das besser, sicherer und kostenfrei anbieten? Heute sind die Probleme dieser Entwicklungen aber deutlich zu erkennen. Im Folgenden werden die Herausforderungen dieser Nischenbildung, die dunkle Seite der zentralisierten Infrastrukturen sowie die darauf reagierenden, neue Entwürfe für de-zentrale Infrastrukturen skizziert.

  1. Boltzmann und das Ende des mechanistischen Weltbildes

    CERN Document Server

    Renn, Jürgen

    2007-01-01

    Der Wissenschaftshistoriker und Physiker Jürgen Renn untersucht die Rolle des österreichischen Physikers und Philosophen Ludwig Boltzmann (18441906) bei der Entwicklung der modernen Physik. Boltzmann war einer der letzen Vertreter des mechanistischen Weltbildes und stand somit am Ende eines Zeitalters. Renn porträtiert den Wissenschaftler aber als einen Pionier der modernen Physik, dessen Beschäftigung mit den inneren Spannungen der klassischen Physik ihn visionär zukünftige Fragestellungen aufgreifen ließ. So befasste sich Boltzmann etwa mit den Grenzproblemen zwischen Mechanik und Thermodynamik, die ihn zur Entwicklung immer raffinierterer Instrumente der statistischen Physik antrieb, die schließlich zu Schlüsselinstrumenten der modernen Physik wurden. Boltzmanns Werk steht somit am Übergang vom mechanistischen Weltbild zur Relativitäts- und Quantentheorie. Der Aussage des viel bekannteren Physikers Albert Einstein, dass Fantasie wichtiger sei als Wissen, hält Jürgen Renn im Hinblick auf Leben ...

  2. Kontinuierliche Wanddickenbestimmung und Visualisierung des linken Herzventrikels

    Science.gov (United States)

    Dornheim, Lars; Hahn, Peter; Oeltze, Steffen; Preim, Bernhard; Tönnies, Klaus D.

    Zur Bestimmung von Defekten in der Herztätigkeit kann die Veränderung der Wanddicke des linken Ventrikels in zeitlichen MRTAufnahmesequenzen gemessen werden. Derzeit werden für diese Bestimmung im allgemeinen nur die aufwändig manuell erstellte Segmentierungen der Endsystole und Enddiastole benutzt. Wir stellen ein bis auf die Startpunktinitialisierung automatisches Verfahren zur Bestimmung der Wanddicke des linken Ventrikels und ihrer Veränderung vor, das auf einer vollständigen Segmentierung der Herzwand in allen Zeitschritten durch ein dynamisches dreidimensionales Formmodell (Stabiles Feder-Masse-Modell) basiert. Dieses Modell nutzt bei der Segmentierung neben der Grauwertinformation eines Zeitschrittes auch die Segmentierungen der anderen Zeitschritte und ist so aufgebaut, dass die Wanddicken direkt gemessen und visualisiert werden können. Auf diese Weise werden die lokalen Wanddickenextrema über den gesamten Aufnahmezeitraum detektiert, auch wenn sie nicht in die Endsystole bzw. -diastole fallen. Das Verfahren wurde auf sechs 4D-Kardio-MRT-Datensätzen evaluiert und stellte sich als sehr robust bzgl. der einzig nötigen Interaktion heraus.

  3. Schule und Bildung im Prozess der Globalisierung

    Directory of Open Access Journals (Sweden)

    Jürgen Oelkers

    2000-05-01

    Full Text Available Der Autor erörtert die Auswirkungen der Globalisierung auf Schulen, Lern- und Lehrarrangements sowie die künftige Rolle der Bildung innerhalb der vernetzten, entgrenzten Lebensräume. Dabei geht er der Frage nach, welche Rolle die Schule als traditionell ortsgebundene Einrichtung hinsichtlich der Vorbereitung auf einen globalem Arbeitsmarkt mit seinen Unsicherheiten einnehmen kann. Zunächst beschreibt er allgemeine Tendenzen der Individualisierung und Flexiblisierung von Arbeitsbedingungen, um Konsequenzen für die Kindheit abzuleiten (Zeit der Eltern als knappes Gut, Kommerzialisierung. In einem zweiten Schritt verdeutlicht er, welche Auswirkungen die neuen Medien Internet und Computer für das Lernen haben (Ungebundenheit hinsichtlich Ort, Zeit, damit verknüpft die Unverlässlichkeit von Quellen. In einem letzten Schritt charakterisiert er die Konsequenzen der Globalisierung für die Bildung und die Schule (internationale Standards in den drei großen Wirtschaftsräumen, Notwendigkeit der Vermittlung von Wissen zur Strukturierung und Bewertung von Informationen.

  4. Nudges, Recht und Politik: Institutionelle Implikationen

    Directory of Open Access Journals (Sweden)

    Lepenies Robert

    2016-07-01

    Full Text Available In diesem Beitrag argumentieren wir, dass eine umfassende Implementierung sogenannter Nudges weitreichende Auswirkungen für rechtliche und politische Institutionen hat. Die wissenschaftliche Diskussion zu Nudges ist derzeit hauptsächlich von philosophischen Theorien geprägt, die im Kern einen individualistischen Ansatz vertreten. Unsere Analyse bezieht sich auf die Art und Weise, in der sich Anhänger des Nudging neuster Erkenntnisse aus den Verhaltenswissenschaften bedienen – immer in der Absicht, diese für effektives Regieren einzusetzen. Wir unterstreichen, dass die meisten Nudges, die derzeit entweder diskutiert werden oder bereits implementiert sind, nicht Teil eines Rechtssystems sind und keinen normativen Charakter haben. Dazu unterscheiden wir zwischen zwei Idealtypen, um menschliches Verhalten zu beeinflussen, die wir als normativ bzw. instrumentell bezeichnen. Diese Idealtypen stehen für verschiedene Weisen, in denen öffentliche Regeln strukturiert werden können; sie erlauben uns, die institutionellen Implikationen von Nudges zu verstehen und zu bewerten. Hier betonen wir den Wert des Rechts als Absicherung gegenüber den möglichen schädlichen Konsequenzen von in der Politik und Regierungsführung eingesetzten Nudges. Unser Beitrag schließt mit Reaktionen auf einige Einwände, die unsere Vorschläge bereits erhalten haben.

  5. Kunst und Revolution.John Berger und der sowjetische Bildhauer Ernst Neiswestni

    OpenAIRE

    Artinger, Kai

    2011-01-01

    John Berger war einer der einflussreichsten Kunstkritiker der Linken in den 1950er Jahren in Großbritannien. Er spielte eine zentrale Rolle in den Diskursen über die Situation der Kunst und ihre Zukunft. Bezeichnend für sein Kunstverständnis war es, ausgetretene Pfade zu verlassen und den herrschenden Kanon zu ignorieren. Daher erfasste sein Blick auch die osteuropäische Kunst. Seit 1953 besucht er mehrfach die UdSSR und die DDR. Als unabhängiger Marxist lehnte sich Berger an den Strategien...

  6. Lew Kopelew - der Schriftsteller und Wissenschaftler, der Freund der Menschen und Verfechter ihrer Grundrechte

    OpenAIRE

    Keller, Werner

    2010-01-01

    Unsere Erwartung war anders als sonst – freudig, doch nicht frei von Erregung und leiser Furcht: Wird man im Kreml das gegebene Wort halten und nach einem Jahr die Rückkehr in die russische Heimat erlauben? Als Gast Heinrich Bölls kam Lew Kopelew im November 1980 nach Deutschland. In der Bonner Wohnung des Slawisten Wolfgang Kasack konnte ich mich ihm wenige Tage später vorstellen: Er war groß, von beeindruckender Physiognomie – nicht nur durch den Prophetenbart –, allerdings fast bleich und ...

  7. Gedenken, Geschichte und Versöhnung in Südafrika und Zimbabwe

    OpenAIRE

    Marx, Christoph

    2006-01-01

    'Die Gesellschaft Südafrikas hat sich nach der Überwindung der Apartheid mit der Einrichtung einer Wahrheits- und Versöhnungskommission auf eine wichtige öffentliche Debatte über ihre Vergangenheit eingelassen. Der Kontext dieser Debatte und die Vorgabe, dass die Beschäftigung mit der Vergangenheit in die Bildung einer neuen Nation münden solle, führten indes dazu, dass sich neue Formen von Inklusion und Exklusion entwickelten. Da Identität nur über die Betonung von Differenz möglich ist, läs...

  8. Poster - 07: Investigations of the Advanced Collapsed-cone Engine for HDR Brachytherapy Scalp Treatments

    Energy Technology Data Exchange (ETDEWEB)

    Cawston-Grant, Brie; Morrison, Hali; Sloboda, Ron; Menon, Geetha [Cross Cancer Institute, University of Alberta, Edmonton (Canada)

    2016-08-15

    Purpose: To present an investigation of the Advanced Collapsed-cone Engine (ACE) in Oncentraê Brachy (OcB) v4.5 using a tissue equivalent phantom modeling scalp brachytherapy (BT) treatments. Methods: A slab phantom modeling the skin, skull, brain and mold was used. A dose of 400cGy was prescribed to just above the skull layer using TG-43 and was delivered using an HDR afterloader. Measurements were made using Gafchromic™ EBT3 film at four depths within the phantom. The TG-43 planned and film measured doses were compared to the standard (sACE) and high (hACE) accuracy ACE options in OcB between the surface and below the skull. Results: The average difference between the TG-43 calculated and film measured doses was −11.25±3.38% when there was no air gap between the mold and skin; sACE and hACE doses were on average lower than TG-43 calculated doses by 3.41±0.03% and 2.45±0.03%, respectively. With a 3mm air gap between the mold and skin, the difference between the TG-43 calculated and measured doses was −8.28±5.76%; sACE and hACE calculations yielded average doses 1.87±0.03% and 1.78±0.04% greater than TG-43, respectively. Conclusions: TG-43, sACE, and hACE were found to overestimate doses below the skull layer compared to film. With a 3mm air gap between the mold and skin, sACE and hACE more accurately predicted the film dose to the skin surface than TG-43. More clinical variations and their implications are currently being investigated.

  9. Accuracy Evaluation of Oncentra™ TPS in HDR Brachytherapy of Nasopharynx Cancer Using EGSnrc Monte Carlo Code

    Science.gov (United States)

    Hadad, K.; Zohrevand, M.; Faghihi, R.; Sedighi Pashaki, A.

    2015-01-01

    Background HDR brachytherapy is one of the commonest methods of nasopharyngeal cancer treatment. In this method, depending on how advanced one tumor is, 2 to 6 Gy dose as intracavitary brachytherapy is prescribed. Due to high dose rate and tumor location, accuracy evaluation of treatment planning system (TPS) is particularly important. Common methods used in TPS dosimetry are based on computations in a homogeneous phantom. Heterogeneous phantoms, especially patient-specific voxel phantoms can increase dosimetric accuracy. Materials and Methods In this study, using CT images taken from a patient and ctcreate-which is a part of the DOSXYZnrc computational code, patient-specific phantom was made. Dose distribution was plotted by DOSXYZnrc and compared with TPS one. Also, by extracting the voxels absorbed dose in treatment volume, dose-volume histograms (DVH) was plotted and compared with Oncentra™ TPS DVHs. Results The results from calculations were compared with data from Oncentra™ treatment planning system and it was observed that TPS calculation predicts lower dose in areas near the source, and higher dose in areas far from the source relative to MC code. Absorbed dose values in the voxels also showed that TPS reports D90 value is 40% higher than the Monte Carlo method. Conclusion Today, most treatment planning systems use TG-43 protocol. This protocol may results in errors such as neglecting tissue heterogeneity, scattered radiation as well as applicator attenuation. Due to these errors, AAPM emphasized departing from TG-43 protocol and approaching new brachytherapy protocol TG-186 in which patient-specific phantom is used and heterogeneities are affected in dosimetry. PMID:25973408

  10. HDR 192Ir source speed measurements using a high speed video camera

    International Nuclear Information System (INIS)

    Fonseca, Gabriel P.; Viana, Rodrigo S. S.; Yoriyaz, Hélio; Podesta, Mark; Rubo, Rodrigo A.; Sales, Camila P. de; Reniers, Brigitte; Verhaegen, Frank

    2015-01-01

    Purpose: The dose delivered with a HDR 192 Ir afterloader can be separated into a dwell component, and a transit component resulting from the source movement. The transit component is directly dependent on the source speed profile and it is the goal of this study to measure accurate source speed profiles. Methods: A high speed video camera was used to record the movement of a 192 Ir source (Nucletron, an Elekta company, Stockholm, Sweden) for interdwell distances of 0.25–5 cm with dwell times of 0.1, 1, and 2 s. Transit dose distributions were calculated using a Monte Carlo code simulating the source movement. Results: The source stops at each dwell position oscillating around the desired position for a duration up to (0.026 ± 0.005) s. The source speed profile shows variations between 0 and 81 cm/s with average speed of ∼33 cm/s for most of the interdwell distances. The source stops for up to (0.005 ± 0.001) s at nonprogrammed positions in between two programmed dwell positions. The dwell time correction applied by the manufacturer compensates the transit dose between the dwell positions leading to a maximum overdose of 41 mGy for the considered cases and assuming an air-kerma strength of 48 000 U. The transit dose component is not uniformly distributed leading to over and underdoses, which is within 1.4% for commonly prescribed doses (3–10 Gy). Conclusions: The source maintains its speed even for the short interdwell distances. Dose variations due to the transit dose component are much lower than the prescribed treatment doses for brachytherapy, although transit dose component should be evaluated individually for clinical cases

  11. Poster - 07: Investigations of the Advanced Collapsed-cone Engine for HDR Brachytherapy Scalp Treatments

    International Nuclear Information System (INIS)

    Cawston-Grant, Brie; Morrison, Hali; Sloboda, Ron; Menon, Geetha

    2016-01-01

    Purpose: To present an investigation of the Advanced Collapsed-cone Engine (ACE) in Oncentraê Brachy (OcB) v4.5 using a tissue equivalent phantom modeling scalp brachytherapy (BT) treatments. Methods: A slab phantom modeling the skin, skull, brain and mold was used. A dose of 400cGy was prescribed to just above the skull layer using TG-43 and was delivered using an HDR afterloader. Measurements were made using Gafchromic™ EBT3 film at four depths within the phantom. The TG-43 planned and film measured doses were compared to the standard (sACE) and high (hACE) accuracy ACE options in OcB between the surface and below the skull. Results: The average difference between the TG-43 calculated and film measured doses was −11.25±3.38% when there was no air gap between the mold and skin; sACE and hACE doses were on average lower than TG-43 calculated doses by 3.41±0.03% and 2.45±0.03%, respectively. With a 3mm air gap between the mold and skin, the difference between the TG-43 calculated and measured doses was −8.28±5.76%; sACE and hACE calculations yielded average doses 1.87±0.03% and 1.78±0.04% greater than TG-43, respectively. Conclusions: TG-43, sACE, and hACE were found to overestimate doses below the skull layer compared to film. With a 3mm air gap between the mold and skin, sACE and hACE more accurately predicted the film dose to the skin surface than TG-43. More clinical variations and their implications are currently being investigated.

  12. Estimation of distance error by fuzzy set theory required for strength determination of HDR (192)Ir brachytherapy sources.

    Science.gov (United States)

    Kumar, Sudhir; Datta, D; Sharma, S D; Chourasiya, G; Babu, D A R; Sharma, D N

    2014-04-01

    Verification of the strength of high dose rate (HDR) (192)Ir brachytherapy sources on receipt from the vendor is an important component of institutional quality assurance program. Either reference air-kerma rate (RAKR) or air-kerma strength (AKS) is the recommended quantity to specify the strength of gamma-emitting brachytherapy sources. The use of Farmer-type cylindrical ionization chamber of sensitive volume 0.6 cm(3) is one of the recommended methods for measuring RAKR of HDR (192)Ir brachytherapy sources. While using the cylindrical chamber method, it is required to determine the positioning error of the ionization chamber with respect to the source which is called the distance error. An attempt has been made to apply the fuzzy set theory to estimate the subjective uncertainty associated with the distance error. A simplified approach of applying this fuzzy set theory has been proposed in the quantification of uncertainty associated with the distance error. In order to express the uncertainty in the framework of fuzzy sets, the uncertainty index was estimated and was found to be within 2.5%, which further indicates that the possibility of error in measuring such distance may be of this order. It is observed that the relative distance li estimated by analytical method and fuzzy set theoretic approach are consistent with each other. The crisp values of li estimated using analytical method lie within the bounds computed using fuzzy set theory. This indicates that li values estimated using analytical methods are within 2.5% uncertainty. This value of uncertainty in distance measurement should be incorporated in the uncertainty budget, while estimating the expanded uncertainty in HDR (192)Ir source strength measurement.

  13. Commissioning of a well type chamber for HDR and LDR brachytherapy applications: a review of methodology and outcomes.

    Science.gov (United States)

    Mukwada, Godfrey; Neveri, Gabor; Alkhatib, Zaid; Waterhouse, David K; Ebert, Martin

    2016-03-01

    For safe and accurate dose delivery in brachytherapy, associated equipment is subject to commissioning and ongoing quality assurance (QA). Many centres depend on the use of a well-type chamber ('well chamber') for performing brachytherapy dosimetry. Documentation of well chamber commissioning is scarce despite the important role the chamber plays in the whole brachytherapy QA process. An extensive and structured commissioning of the HDR 1000 plus well chamber (Standard Imaging Inc, Middleton WI) for HDR and LDR dosimetry was undertaken at Sir Charles Gairdner Hospital. The methodology and outcomes of this commissioning is documented and presented as a guideline to others involved in brachytherapy. The commissioning tests described include mechanical integrity, leakage current, directional dependence, response, length of uniform response, the influence of insert holders, ion collection efficiency, polarity effect, accuracy of measured air kerma strength (S(K)) or reference air kerma rate (K(R)) and baseline setting (for ongoing constancy checks). For the HDR 1000 plus well chamber, some of the insert holders modify the response curve. The measured sweet length was 2.5 cm which is within 0.5% of that specified by the manufacturer. Correction for polarity was negligible (0.9999) and ion recombination was small (0.9994). Directional dependence was small (less than 0.2%) and leakage current was negligible. The measured K(R) for (192)Ir agreed within 0.11% compared with a second well chamber of similar model and was within 0.5% of that determined via a free-in-air measurement method. Routine constancy checks over a year agreed with the baseline within 0.4%.

  14. SU-C-202-02: A Comprehensive Evaluation of Adaptive Daily Planning for Cervical Cancer HDR Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Meerschaert, R; Paul, A; Zhuang, L [Department of Oncology, Radiation Oncology Division, Wayne State University School of Medicine, Detroit, MI (United States); Nalichowski, A [Department of Oncology, Radiation Oncology Division, Karmanos Cancer Institute, Detroit, MI (United States); Burmeister, J; Miller, A [Department of Oncology, Radiation Oncology Division, Wayne State University School of Medicine, Detroit, MI (United States); Department of Oncology, Radiation Oncology Division, Karmanos Cancer Institute, Detroit, MI (United States)

    2016-06-15

    Purpose: To evaluate adaptive daily planning for cervical cancer patients who underwent high-dose-rate intra-cavitary brachytherapy (HDR-ICBT). Methods: This study included 22 cervical cancer patients who underwent 5 fractions of HDR ICBT. Regions of interest (ROIs) including high-risk clinical tumor volume (HR-CTV) and organs-at-risk (OARs) were manually contoured on daily CT images. All patients were treated with adaptive daily plans, which involved ROI delineation and dose optimization at each treatment fraction. Single treatment plans were retrospectively generated by applying the first treatment fraction’s dwell times adjusted for decay and dwell positions of the applicator to subsequent treatment fractions. Various existing similarity metrics were calculated for the ROIs to quantify interfractional organ variations. A novel similarity score (JRARM) was established, which combined both volumetric overlap metrics (DSC, JSC, and RVD) and distance metrics (ASD, MSD, and RMSD). Linear regression was performed to determine a relationship between inter-fractional organ variations of various similarity metrics and D2cc variations from both plans. Wilcoxon Signed Rank Tests were used to assess adaptive daily plans and single plans by comparing EQD2 D2cc (α/β=3) for OARs. Results: For inter-fractional organ variations, the sigmoid demonstrated the greatest variations based on the JRARM and DSC similarity metrics. Comparisons between paired ROIs showed differences in JRARM scores and DSCs at each treatment fraction. RVD, MSD, and RMSD were found to be significantly correlated to D2cc variations for bladder and sigmoid. The comparison between plans found that adaptive daily planning provided lower EQD2 D2cc of OARs than single planning, specifically for the sigmoid (p=0.015). Conclusion: Substantial inter-fractional organ motion can occur during HDR-BT, which may significantly affect D2cc of OARs. Adaptive daily planning provides improved dose sparing for OARs

  15. An Eight-Year Experience of HDR Brachytherapy Boost for Localized Prostate Cancer: Biopsy and PSA Outcome

    International Nuclear Information System (INIS)

    Bachand, Francois; Martin, Andre-Guy; Beaulieu, Luc; Harel, Francois M.Sc.; Vigneault, Eric

    2009-01-01

    Purpose: To evaluate the biochemical recurrence-free survival (bRFS), the 2-year biopsy outcome and the prostate-specific antigen (PSA) bounce in patients with localized prostate cancer treated with an inversely planned high-dose-rate (HDR) brachytherapy boost. Materials and methods: Data were collected from 153 patients treated between 1999 and 2006 with external beam pelvic radiation followed by an HDR Ir-192 prostate boost. These patients were given a boost of 18 to 20 Gy using inverse-planning with simulated annealing (IPSA).We reviewed and analyzed all prostate-specific antigen levels and control biopsies. Results: The median follow-up was 44 months (18-95 months). When categorized by risk of progression, 74.5% of patients presented an intermediate risk and 14.4% a high one. Prostate biopsies at 2 years posttreatment were negative in 86 of 94 patients (91.5%), whereas two biopsies were inconclusive. Biochemical control at 60 months was at 96% according to the American Society for Therapeutic Radiology and Oncology and the Phoenix consensus definitions. A PSA bounce (PSA values of 2 ng/mL or more above nadir) was observed in 15 patients of 123 (9.8%). The median time to bounce was 15.2 months (interquartile range, 11.0-17.7) and the median bounce duration 18.7 months (interquartile range, 12.1-29). The estimate of overall survival at 60 months was 97.1% (95% CI, 91.6-103%). Conclusions: Considering that inverse planned HDR brachytherapy prostate boosts led to an excellent biochemical response, with a 2-year negative biopsy rate, we recommend a conservative approach in face of a PSA bounce even though it was observed in 10% of patients

  16. The influence of the dwell time deviation constraint (DTDC) parameter on dosimetry with IPSA optimisation for HDR prostate brachytherapy

    International Nuclear Information System (INIS)

    Smith, Ryan L.; Millar, Jeremy L.; Panettieri, Vanessa; Mason, Natasha; Lancaster, Craig; Francih, Rick D.

    2015-01-01

    To investigate how the dwell time deviation constraint (DTDC) parameter, applied to inverse planning by simulated annealing (IPSA) optimisation limits large dwell times from occurring in each catheter and to characterise the effect on the resulting dosimetry for prostate high dose rate (HDR) brachytherapy treatment plans. An unconstrained IPSA optimised treatment plan, using the Oncentra Brachytherapy treatment planning system (version 4.3, Nucletron an Elekta company, Elekta AB, Stockholm, Sweden), was generated for 20 consecutive HDR prostate brachytherapy patients, with the DTDC set to zero. Successive constrained optimisation plans were also created for each patient by increasing the DTDC parameter by 0.2, up to a maximum value of 1.0. We defined a “plan modulation index”, to characterise the change of dwell time modulation as the DTDC parameter was increased. We calculated the dose volume histogram indices for the PTV (D90, V100, V150, V200%) and urethra (D10%) to characterise the effect on the resulting dosimetry. The average PTV D90% decreases as the DTDC is applied, on average by only 1.5 %, for a DTDC = 0.4. The measures of high dose regions in the PTV, V150 and V200%, increase on average by less than 5 and 2 % respectively. The net effect of DTDC on the modulation of dwell times has been characterised by the introduction of the plan modulation index. DTDC applied during IPSA optimisation of HDR prostate brachytherapy plans reduce the occurrence of large isolated dwell times within individual catheters. The mechanism by which DTDC works has been described and its effect on the modulation of dwell times has been characterised. The authors recommend using a DTDC parameter no greater than 0.4 to obtain a plan with dwell time modulation comparable to a geometric optimised plan. This yielded on average a 1.5 % decrease in PTV coverage and an acceptable increase in V150%, without compromising the urethral dose.

  17. Aggregation und Management von Metadaten im Kontext von Europeana

    Directory of Open Access Journals (Sweden)

    Gerda Koch

    2017-09-01

    Full Text Available Mit dem In-Beziehung-Setzen und Verlinken von Daten im Internet wird der Weg zur Umsetzung des semantischen Webs geebnet. Erst die semantische Verbindung von heterogenen Datenbeständen ermöglicht übergreifende Suchvorgänge und späteres „Machine Learning“. Im Artikel werden die Aktivitäten der Europäischen Digitalen Bibliothek im Bereich des Metadatenmanagements und der semantischen Verlinkung von Daten skizziert. Dabei wird einerseits ein kurzer Überblick zu aktuellen Forschungsschwerpunkten und Umsetzungsstrategien gegeben, und darüber hinaus werden einzelne Projekte und maßgeschneiderte Serviceangebote für naturhistorische Daten, regionale Kultureinrichtungen und Audiosammlungen beschrieben.

  18. Islam, Migration und Integration: Konflikte jugendlicher Migranten mit islamischem Hintergrund

    Directory of Open Access Journals (Sweden)

    Ilhan Kizilhan

    2008-04-01

    Full Text Available Der Islam mit seinen verschiedenen Verhaltensweisen und Verboten spielt direkt oder indirekt immer noch eine wichtige Rolle im alltäglichen Leben vieler Migranten. Religiöse Vorschriften zeichnen sich dadurch aus, dass ihrer Achtung nicht juristisch, sondern durch sozialen Druck Nachdruck verliehen wird (Verwandtschaft, religiöse Lehrer, islamische Gemeinde, religiöse Vereine etc. und dass ihre Missachtung mit Folgen in Form von Ausgrenzung, Missachtung und Diskriminierung einhergeht. Die kulturellen Vorstellungen der ersten Generation unterscheiden sich auf Grund der unterschiedlichen Biografien von denen der zweiten und dritten durch den Grad der Verwurzelung in der kulturellen Identität und der Verbundenheit mit traditionellen Wertvorstellungen. Fehlende Integrationskonzepte, Ausgrenzung im Migrationsland auf der einen und weltweite staatliche und halbstaatliche Konflikte im Namen des Islams bis hin zum Terrorismus auf der anderen Seite haben einen erheblichen Einfluss auf den Integrationsgrad von jugendlichen Migranten im Aufnahmeland.

  19. Geschichtsbezogene und rechtspolitische Polonica im Bücherbestand Gottfried Lengnichs

    Directory of Open Access Journals (Sweden)

    Iwona Imańska

    2017-11-01

    Full Text Available Gottfried Lengnich, der Historiker und Syndikus der Stadt Danzig aus dem 18. Jahrhundert, hinterließ eine Büchersammlung mit über viertausend Büchern, die nach seinem Tode in zwei Auktionen im Juli und November 1774 versteigert werden sollten. Die Auktionskataloge befinden sich in der Staatsbibliothek zu Berlin – Stiftung Preußischer Kulturbesitz und sind auch online zugänglich. Wegen wissenschaftlicher Interessen Lengnichs befanden sich in seiner Bibliothek ca. 600 Polonica-Drucke, die meisten davon waren Abhandlungen im Themenfeld Geschichte, Recht und Politik. Die Analyse dieses Fragments des Bücherbestands Lengnichs bewies, dass der Syndikus eine perfekte Arbeitswerkstatt für sich schuf, indem er die Werke der meisten wichtigsten polnischen und fremden Autoren, die über die Geschichte und die Gesetzgebung Polens und Preußens schrieben, sammelte.

  20. Results of combined photodynamic therapy (PDT) and high dose rate brachytherapy (HDR) in treatment of obstructive endobronchial non-small cell lung cancer

    Science.gov (United States)

    Weinberg, Benjamin D.; Allison, Ron R.; Sibata, Claudio; Parent, Teresa; Downie, Gordon

    2009-06-01

    We reviewed the outcome of combined photodynamic therapy (PDT) and high dose rate brachytherapy (HDR) for patients with symptomatic obstruction from endobronchial non-small cell lung cancer. Methods: Nine patients who received combined PDT and HDR for endobronchial cancers were identified and their charts reviewed. The patients were eight males and one female aged 52-73 at diagnosis, initially presenting with various stages of disease: stage IA (N=1), stage IIA (N=1), stage III (N=6), and stage IV (N=1). Intervention was with HDR (500 cGy to 5 mm once weekly for 3 weeks) and PDT (2 mg/kg Photofrin, followed by 200 J/cm2 illumination 48 hours post infusion). Treatment group 1 (TG-1, N=7) received HDR first; Treatment group 2 (TG-2, N=2) received PDT first. Patients were followed by regular bronchoscopies. Results: Treatments were well tolerated, all patients completed therapy, and none were lost to follow-up. In TG-1, local tumor control was achieved in six of seven patients for: 3 months (until death), 15 months, 2+ years (until death), 2+ years (ongoing), and 5+ years (ongoing, N=2). In TG-2, local control was achieved in only one patient, for 84 days. Morbidities included: stenosis and/or other reversible benign local tissue reactions (N=8); photosensitivity reaction (N=2), and self-limited pleural effusion (N=2). Conclusions: Combined HDR/PDT treatment for endobronchial tumors is well tolerated and can achieve prolonged local control with acceptable morbidity when PDT follows HDR and when the spacing between treatments is one month or less. This treatment regimen should be studied in a larger patient population.

  1. SU-E-T-380: Evaluation of BEBIG HDR 60Co System for AccuBoost Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Zehtabian, M; Sina, S [Shiraz University, Shiraz, Fars (Iran, Islamic Republic of); Rivard, M [Tufts University School of Medicine, Boston, MA (United States); Meigooni, A Soleimani [Comprehensive Cancer Center of Nevada, Las Vegas, Nevada (United States)

    2015-06-15

    Purpose: In this project, the possibility of utilizing the BEBIG 60Co HDR system for AccuBoostTM treatment has been evaluated. Methods: Dose distributions in various breast sizes have been calculated for both Co-60 and Ir-192 sources using the MCNP5 code. These calculations were performed in breast tissues with thicknesses of 4cm, 6cm, and 8cm. The initial calculations were performed with the same applicator dimensions as the existing applicators used with the HDR Ir-192 system. The activity of the Co-60 source was selected such that the dose at the breast center was the same as the values from 192Ir. Then, the applicator thicknesses were increased to twice of those used with HDR Ir-192 system, for reducing skin and chest doses by Co-60 system. Dose to breast skin and chest wall were compared for both applicators types, with and without inclusion of a focusing cone at the applicator center. Results: The results showed that loading HDR Co-60 source inside the thin applicators impose higher doses to breast skin and chest wall compared to the 192Ir source. The area of the chest wall covered by 10Gy when treated by Co-60 with the thin and thick applicators, or treated by Ir-192 with thin applicator are 79cm2, 39cm2, and 3.8cm2, respectively. These values are reduced to 34cm2, 0cm2, and 0cm2 by using the focusing cone. It is worth noting that the breast skin areas covered by the 60Gy isodose line are 9.9cm2 and 7.8cm2 for Co-60 with the thin and thick applicators, respectively, while it is 20cm2 for Ir-192 when no focusing cone is present. These values are 0cm2, 0cm2, and 11cm2 in the presence of the focusing cone. Conclusion: The results indicate that using Co-60 with the thicker applicators is beneficial because of the higher half-life of Co-60, and the reduced maximum skin dose when compared with Ir-192.

  2. Einleitung: Jahrbuch Medienpädagogik 5. Evaluation und Analyse

    Directory of Open Access Journals (Sweden)

    Ben Bachmair

    2017-09-01

    Full Text Available Evaluationsmethoden für E-Learning, Forschungsmethoden zur Mediennutzung und zur Analyse von Medienkulturen sind Gegenstand dieses Jahrbuchs Medienpädagogik. Dabei reicht das Spektrum der Medien von Fernsehen über Video bis zum Internet. Die Auswahl dieses Themenschwerpunkts kommt dabei nicht von ungefähr. Zum einen hat wissenschaftliche Medienforschung bereits eine lange Tradition und ist in vielen Disziplinen etabliert. Forschungsmethoden lieferten der medienpädagogischen Praxis empirisch fundierte Ergebnisse und Instrumente. Forschungsdesigns und Methodologien wurden entwickelt, um Mediennutzungsverhalten und Medienwirkungen zu erklären, Evaluationsmethoden eingesetzt, um Lernprozesse zu beurteilen. Zum anderen gewinnen Qualitätssicherung und Leistungsmessungen im Bildungssystem generell immer mehr an Bedeutung. In den Ergebnissen aktueller Evaluationen zeigen sich Bestrebungen nach Qualität von Bildungs- und Lernprozessen. Empirische Forschung kommt die Aufgabe zu medienpädagogische Wirkungsgrade und Zielerreichung zu überprüfen und zu kontrollieren. Quantitative Forschungsmethoden ermöglichen es Mediennutzungsverhalten bestimmter Zielgruppen in Wechselwirkung mit Programmstrukturen und -inhalten zu ermitteln. Nutzungsmuster von Medienangeboten – vor allem bei Kindern und Jugendlichen – sind auch bei der Entwicklung medienpädagogischer Ansätze wichtig. Qualitative Medienforschung dient als Planungsinstrument für medienpädagogische Konzeptionen sowie für medienpädagogische Praxis und hilft bei der Entwicklung neuer, mehr als bisher an inhaltlichen Kriterien orientierter Angebote eingesetzt werden. Eine der zentralen Fragestellungen war und ist dabei, mit welchen kognitiven und ästhetischen Vermittlungsformen die Inhalte einer Sendung am besten kommuniziert werden können. Dies ist zugleich eine der Grundfragen im Hinblick auf den Medieneinsatz in pädagogisch orientierten Lernprozessen (vgl. Dichanz 1998.

  3. Climate protection and competition; Klimaschutz und Wettbewerb

    Energy Technology Data Exchange (ETDEWEB)

    Diekmann, M. [Stadtwerke Braunschweig GmbH (Germany)

    1998-06-01

    Discussions on energy-related matters have recently been dominated above all by the two issues climate protection and the introduction of competition. The public utility Stadtwerke Braunschweig GmbH and its subsidiaries Braunschweiger Versorgungs-AG and Braunschweiger Verkehrs-AG have committed themselves to the cause of climate protection. The ongoing implementation of the utility`s energy supply concept is making a substantial contribution to energy conservation and air pollution control. [Deutsch] Die Diskussionen zum Thema Energie werden in der letzten Zeit im wesentlichen von zwei Themen beherrscht: Klimaschutz und Einfuehrung von Wettbewerb. Die Stadtwerke Braunschweig GmbH mit ihren Tochtergesellschaften Braunschweiger Versorgungs-AG und Braunschweiger Verkehrs-AG engagieren sich im Klimaschutz. Die fortlaufende Umsetzung des Energieversorgungskonzepts der Stadtwerke traegt wesentlich zur Energieeinsparung und zur Reduzierung von Schadstoff-Emissionen bei. (orig./MSK)

  4. Grundlage und Bedeutung der operativen Endometriosetherapie

    Directory of Open Access Journals (Sweden)

    Schweppe KW

    2009-01-01

    Full Text Available Die Endometriose wird invasiv durch Laparoskopie und bioptische Sicherung diagnostiziert, sodass es nahe liegt, dass sich die chirurgische Therapie in gleicher Narkose anschließt. Unterschiedliche Wachstumsformen der Endometriose einerseits (kleinherdig-peritoneal, zystisch-ovariell oder tief infiltrierend und unterschiedliche Therapieziele andererseits (Schmerzfreiheit, Tumorbeseitigung, Schwangerschaft erfordern einen individuellen Behandlungsplan, der auch das Alter der Patientin mitberücksichtigt. Medikamentöse Therapieoptionen spielen additiv zum primär operativen Vorgehen eine Rolle, wobei oft symptomatische Maßnahmen bei dieser chronischen, rezidivierenden Krankheit ausreichen. Endoskopische Operationstechniken sind heute Standard. Unterschiede in Erfolgs- und Rezidivraten sind bisher für die verschiedenen Techniken nicht durch randomisierte Studien belegt.

  5. [Die baltischen Lande im Zeitalter der Reformation und Konfessionalisierung. Livland, Estland, Ösel, Ingermanland, Kurland und Lettgallen. Stadt, Land und Konfession 1500-1721. Teil I] / Heinrich Wittram

    Index Scriptorium Estoniae

    Wittram, Heinrich, 1931-

    2011-01-01

    Arvustus : Die baltischen Lande im Zeitalter der Reformation und Konfessionalisierung. Livland, Estland, Ösel, Ingermanland, Kurland und Lettgallen. Stadt, Land und Konfession 1500-1721. Teil I. Münster : Aschendorff, 2009. (Katholisches Leben und Kirchenreform im Zeitalter der Glaubensspaltung, 69)

  6. [Christofer Herrmann. Kloster und Burg - die architektur des Deutschens Ordens im Pressen und Livland. In : Glaube, Macht und Pracht. GeistlicheGemeinschaften des Ostseeraums im Zeitalter der Backsteingotik] / Dennis Hortmuth

    Index Scriptorium Estoniae

    Hortmuth, Dennis

    2011-01-01

    Arvustus: Christofer Herrmann. Kloster und Burg - die Architektur des Deutschen Ordens in Preussen und Livland. In : Glaube, Macht und Pracht. GeistlicheGemeinschaften des Ostseeraums im Zeitalter der Backsteingotik (=Archäologie und Geschichte im Ostseeraum; Archaeology and History of the Baltic 6) Rahden : Verlag Marie Leidorf, 2009. S. 209-219. Saksa Ordu arhitektuurist Preisi- ja Liivimaal

  7. [St. Petersburg und Livland - und die Entwicklung der estnischen Literatur : Anton Schiefner (1817-1879) und Friedrich R. Kreutzwald (1803-1882) im Briefwechsel (1853-1879)] / Felix Köther

    Index Scriptorium Estoniae

    Köther, Felix

    2015-01-01

    Arvustus: St. Petersburg und Livland - und die Entwicklung der estnischen Literatur : Anton Schiefner (1817-1879) und Friedrich R. Kreutzwald (1803-1882) im Briefwechsel (1853-1879) / bearbeitet von Hartmut Walravens. Wiesbaden : Harrassowitz, 2013. (Orientalistik-Bibliographien und Dokumentationen ; Bd. 22)

  8. CAPM und Behavioral Finance - Versuch einer Synthese

    OpenAIRE

    Hackl, Harald

    2013-01-01

    Seit Etablierung der ersten Börsen als Marktplatz für fungible Güter sind Marktteilnehmer und die Wissenschaft bemüht, Erklärungen für das Zustandekommen von Marktpreisen zu finden. Im Laufe der Zeit wurden diverse Modelle entwickelt. Allen voran ist das neoklassische Capital Asset Pricing Modell (CAPM) zu nennen. Die Neoklassik sieht den Akteur an den Finanzmärkten als emotionslosen und streng rationalen Entscheider, dem sog. homo oeconomicus. Psychologische Einflussfaktoren bei der Preisbil...

  9. Gõtter, Grãber und Gelehrte

    Directory of Open Access Journals (Sweden)

    Pedro Moacyr Campos

    1953-09-01

    Full Text Available CERAM, (C. W.. — Gõtter, Grãber und Gelehrte, Rowohlt Verlag, Hamburg.,  1951, 494 págs. (Primeiro Parágrafo do Artigo Bem merecido foi o sucesso encontrado pelo livro de Ceram, Gotter, Graber und Gelehrte, ("Deuses, túmulos e eruditos", que alcançou a cifra de 106.000 exemplares entre novembro de 1949 e março de 1951, continuando a ser reimpresso após esta data.

  10. Industrie 4.0-Strategien und Reifegrad

    OpenAIRE

    Hofmann, Erik; Oettmeier, Katrin

    2017-01-01

    Industrie 4.0 ist in aller Munde. Ermöglicht wird diese «vierte industrielle Revolution» durch die flexible digitale Vernetzung von Objekten (z.B. Produkten oder Maschinen) über das Internet und andere Netzwerkdienste. Im Rahmen der Fokusstudie «SCM 4.0: Supply Chain Management und digitale Vernetzung» wird der aktuelle Stand der Implementierung von Industrie 4.0 bei Schweizer Unternehmen analysiert. Anhand einer grosszahligen Erhebung wird dabei neben dem derzeitigen Reifegrad auch die vo...

  11. Zeitarbeit in Deutschland: Trends und Perspektiven

    OpenAIRE

    Burda, Michael C.; Kvasnicka, Michael

    2004-01-01

    Die Zeitarbeit bietet sowohl hochregulierten als auch unregulierten Arbeitsmärkten ein zusätzliches Mittel zur betriebswirtschaftlichen Anpassung der Arbeitsnachfrage. Auch eröffnet sie für Berufsanfänger und vormalig Beschäftigte einen Weg in den Arbeitsmarkt. Der vorliegende Aufsatz analysiert die wirtschaftliche Bedeutung, die wechselnden gesetzlichen Rahmenbedingungen und die ökonomische Entwicklung der Zeitarbeit am deutschen Arbeitsmarkt. Hohe Aufschläge für Zeitarbeitseinsätze trotz fa...

  12. Semiokapitalismus und imperiale Kontrollgesellschaft Zur Digitalisierung der Produktion am Beginn des 21. Jahrhunderts

    Directory of Open Access Journals (Sweden)

    Wolfgang Neurath

    2014-12-01

    Full Text Available Wolfgang Neurath analysiert angesichts des kybernetischen Semiokapitalismus und des durch ihn entstandenen "Kognitariats" in welcher Art und Weise digitale Produktions- und Wertschöpfungsprozesse am Beginn des 21. Jahrhunderts zur Kontrolle eingesetzt werden ...

  13. Medien – Wissen – Bildung 2011: Kulturen und Ethiken des Teilens

    Directory of Open Access Journals (Sweden)

    Valentin Dander

    2011-12-01

    Full Text Available Die Tagung Medien – Wissen – Bildung 2011 bot Forschern, Künstlern und Interessierten verschiedener Disziplinen ein Forum, die kulturellen und ethischen Grundlagen und Bedeutungen des Teilens in digitalisierten Gesellschaften in seinen zahlreichen Dimensionen zu diskutieren.

  14. Zwischenberichterstattung nach Börsenrecht, DRS, IAS und US-GAAP

    OpenAIRE

    Alvarez von Zerboni di Sposetti, Manuel

    2003-01-01

    Zwischenberichterstattung nach Börsenrecht, DRS, IAS und US-GAAP / von Manuel Alvarez und Stefan Wotschofsky. - 2., neubearb. und erw. Aufl. - Berlin : Erich Schmidt, 2003. - XX, 219 S. [1. Aufl. 2000

  15. [Leonid Arbusow (1882-1951) und die Erforschung des mittelalterlichen Livland] / Dennis Hormuth

    Index Scriptorium Estoniae

    Hormuth, Dennis, 1979-

    2015-01-01

    Arvustus: Leonid Arbusow (1882-1951) und die Erforschung des mittelalterlichen Livland / Ilgvars Misāns und Klaus Neitmann (Hg.). Köln [etc.] : Böhlau, 2014. (Quellen und Studien zur baltischen Geschichte ; Bd. 24)

  16. Editorial zum Tagungsband: Spannungsfelder und blinde Flecken. Medienpädagogik zwischen Emanzipationsanspruch und Diskursvermeidung

    Directory of Open Access Journals (Sweden)

    Sven Kommer

    2017-10-01

    Full Text Available Die erziehungswissenschaftliche Auseinandersetzung mit Medien hat in Deutschland eine lange und vielfältige Tradition. In den letzten Jahrzehnten hat sich die Medienpädagogik zu einer eigenständigen akademischen (Teil-Disziplin entwickelt, die in der (Fach-Öffentlichkeit wahrgenommen wird und sich aktiv in aktuelle gesellschaftliche Diskurse einbringt. Sichtbar wird die Etablierung als Fach u. a. daran, dass an einer Reihe von Hochschulen Professuren geschaffen wurden, die für medienpädagogische Studienelemente oder -gänge und/oder Zusatzausbildungen verantwortlich sind. Der gestiegene Stellenwert der Disziplin zeigt sich auch an ihrer Rolle in der Deutschen Gesellschaft für Erziehungswissenschaft, innerhalb derer sie sich von einer «Arbeitsgemeinschaft auf Zeit» (Mitte der 1990er-Jahre zu einer eigenständigen Sektion (seit 2010 entwickelt hat. Angesichts der gegenwärtig zu beobachtenden Entwicklungen im Medienbereich (u. a. Digitalisierung, Globalisierung, Algorithmisierung, deren Folgen für gesellschaftliche und pädagogische Prozesse und Bereiche kaum zu unterschätzen sind, erstaunt es, dass die Medienpädagogik bis heute dazu neigt, Rechtfertigungsstrategien für die eigenen Existenz zu generieren. Bei einer kritischen Betrachtung (z. B. der universitären Stellenpolitik ist aber zu konstatieren, dass sich die Medienpädagogik auch 40 Jahre nach dem Erscheinen von Dieter Baackes wegweisender Schrift Kommunikation und Kompetenz ihrer Anerkennung und festen Verankerung im akademischen Feld tatsächlich noch immer nicht sicher sein kann. Eine Ursache hierfür liegt möglicherweise in der noch immer grossen (und oftmals geradezu zelebrierten Heterogenität des Faches. So sind die unterschiedlichen Traditionslinien des pädagogischen Umgangs mit Medien, die mitunter nur bedingt miteinander vereinbar sind, bis heute zu beobachten und wirkmächtig. Zu unterscheiden ist hierbei bspw. eine auf Emanzipation, kommunikative Kompetenz

  17. Neuro-Enhancement — klinische, soziale und ethische Dimensionen: Kognitive Leistungssteigerung in Kindheit und Jugend

    NARCIS (Netherlands)

    Nagel, S.K.; Nagel, Saskia Kathi

    2015-01-01

    Der als Neuro-Enhancement bezeichnete Einsatz meist verschreibungspflichtiger Medikamente oder Technologien zur Steigerung kognitiver Leistungen und Verbesserung affektiver Zustände bei Gesunden findet in den letzten Jahren vermehrt Anwendung. Skeptiker befürchten allerdings eine zunehmende

  18. Editorial: Nachhaltigkeit und fachdidaktische Herausforderungen

    Directory of Open Access Journals (Sweden)

    Andreas Fischer

    2009-08-01

    Full Text Available Obwohl sich der Diskurs über Nachhaltigkeit in den letzten Jahren intensiviert hat, ist das Thema wirtschaftsdidaktisch „unterbelichtet“. Im Beitrag werden – ohne einen Anspruch auf Vollständigkeit – Forschungszugänge für (Gestaltungs- Kompetenzen, Curricula, fachdidaktische Konzepte, Lehr-Lern-Arrangements, die Leistungserfassung und die lehrenden Akteure skizziert. Eröffnet werden einige wirtschaftsdidaktische Forschungskorridore, die für eine Bildung für nachhaltige Entwicklung in der ökonomischen Bildung von Interesse sein könnten. Ausgangspunkt ist die Überlegung, dass die ökonomische Bildung erst durch die Auseinandersetzung mit Nachhaltigkeit ihren Bildungsauftrag erfüllt.Although the discourse about sustainability has intensified over the last few years, this topic still does not get sufficient attention from the point of view of economical didactics. In this article, the writer outlines different research approaches for competences of organization, curricula, concepts of technical didactics, classroom arrangements that involve teaching and learning, the assessment of performances and the learning individuals. This contribution is not exhausting and therefore might be subject to amendments in the future. The writer presents a number of research approaches that seem to be promising for gains within the field of education for sustainable development and vocational education. As a starting point, the writer deems important that economical education can only fulfill its mission goals through an intense discourse about sustainability.

  19. Übergewicht und Adipositas, Gesundheit und Krankheit : Diskussionsbeiträge aus philosophischer Sicht

    OpenAIRE

    Gottschalk-Mazouz, Niels; Ertelt, Susanne; Radinkovic, Zeljko

    2010-01-01

    Der vorliegende Band vereint Studien, die im Rahmen des Philosophie-Teilprojekts des Forschungsverbunds "Übergewicht und Adipositas bei Kindern, Jugendlichen und jungen Erwachsenen als systemisches Risiko" entstanden sind. Dieser Verbund wurde vom BMBF von 2006-2009 im Rahmen der sozial-ökologischen Forschung im Themenbereich: Strategien zum Umgang mit systemischen Risiken gefördert. In diesem Verbund wurden unter der Leitung des Risikosoziologen Ortwin Renn die Perspektiven von Epidemiologie...

  20. Die Sprache des Marketings und ihre Übersetzung: Morphologische und semantische Aspekte der Terminologie

    OpenAIRE

    Konovalova, Anastasia; Ruiz Yepes, Guadalupe

    2016-01-01

    This article is the English version of “Die Sprache des Marketings und ihre Übersetzung: Morphologische und semantische Aspekte der Terminologie” by Anastasia Konovalova & Guadalupe Ruiz Yepes. It was not published on the print version of MonTI for reasons of space. The online version of MonTI does not suffer from these limitations, and this is our way of promoting plurilingualism. The importance of languages for special purposes in multinational companies grows with each passing day. Simu...