Der Einfluss der Digitalisierung auf die Organisation eines Unternehmens

NASA Astrophysics Data System (ADS)

Walter, Wolfram M.

Die Digitalisierung schreitet mit großen Schritten voran. Dies wirkt sich nicht nur auf die Gesellschaft im Grundsatz, sondern auch auf das Verhalten der Kunden aus. Neue Kommunikationswege beschleunigen die Interaktion zwischen Unternehmen und Verbraucher. Im Vergleich mit großen Internetfirmen werden etablierte Dienstleistungsunternehmen - vom Energieversorger bis zu Versicherungen - stark unter Druck gesetzt, sich noch intensiver mit dem Kundenservice auseinanderzusetzen. Dies wird nur möglich sein, wenn sich die Organisationen entsprechend positionieren und sich frühzeitig auf die Veränderungen einstellen. Hieraus ergeben sich mehr Chancen als Risiken, zumal es nicht nur neue Prozesse, sondern auch neue Berufsbilder geben wird.

Kundenfokus: Startpunkt für die digitale Transformation bei Stadtwerken

NASA Astrophysics Data System (ADS)

Fett, Perry; Küller, Philipp

Big Data, Internet der Dinge, Mobile Computing und soziale Medien - die modernen Informationstechnologien durchdringen den Alltag der meisten Menschen und lösen hierdurch eine digitale Transformation aus. Im Unternehmenskontext manifestiert sich die Digitalisierung durch eine neue Qualität der wissensbasierten Entscheidungsunterstützung und der Automatisierung bzw. Autonomisierung der Geschäftsprozesse. Für Stadtwerke gilt es nun, die Chancen der Digitalisierung zu ihren Gunsten zu nutzen. Ein Startpunkt könnte hierbei sein, wie Stadtwerke zukünftig mit ihren Kunden interagieren. Ausgelöst durch die Liberalisierung der Märkte rückt der Kunde heute stärker in den Mittelpunkt - die Energiewirtschaft steht nun vor der Herausforderung, dem Wettbewerb einen Schritt voraus zu sein und dem Kunden ein absolut positives Kundenerlebnis (Customer Experience) sowohl als Maßnahme zur Kundenbindung als auch zum Kundenaufbau zu bieten. Das vorliegende Kapitel zeigt hierfür die Erfolgskriterien für die gelungene Etablierung des Kundenfokus im eigenen Unternehmen auf. Mit dem Customer-Focus-Cycle-Modell von Fujitsu, angelehnt an den Deming-Kreislauf, wird ein allgemeingültiger Ansatz für ein mögliches Vorgehen beim Aufbau des Kundenfokus vorgestellt. Die sechs Phasen werden dabei anhand praktischer Beispiele erläutert und geben zudem Hinweise zu Methoden und Tools. Aus dem vorgestellten "Werkzeugkasten" wird ferner die Customer-Journey-Methode im Detail erläutert. Weiter soll das präsentierte Reifegradmodell Unternehmen dabei unterstützen, den eigenen Status quo festzustellen und die persönlichen Ziele auf dem Weg zur kundenzentrierten Organisation festzulegen.

25 Jahre - Institut fuer Geodaesie, Teil 3: Aus dem Leben des Instituts (25 Years - Institute of Geodesy, Part 3: The Life of the Institute)

DTIC Science & Technology

2000-01-01

Kraftwerk Qinshan, VR China 0 1984 bis 1987 Studiumn des Markscheidewesens am Shandong Institute of Mining and Technology, VR China * 1984 bis 1993...die zur Wasserversorgung eines Kraftwerkes der ALCAN dienen sollte. Verbunden mit dem Tunnelprojekt war auch der Bau einer 80 km langen Hoch...spannungsleitung durch unverdorbene Wildnis vom Kraftwerk zur Aluminium-Schmelze in Ki- timat. Zu dieser Zeit war es das gr66Bte hydro-elektrische Projekt, das

Von Donuts und Zucker: Mit Neutronen biologische Makromoleküle erforschen

NASA Astrophysics Data System (ADS)

May, Roland P.

2003-05-01

Für die Erforschung von Biomolekülen bieten Neutronen einzigartige Eigenschaften. Vor allem ihre unterschiedliche Wechselwirkung mit dem natürlichen Wasserstoff und seinem schweren Isotop Deuterium ermöglicht tiefe Einblicke in Struktur, Funktion und Dynamik von Proteinen, Nukleinsäuren und Biomembranen. Bei vielen Fragestellungen zur Strukturaufklärung gibt es kaum oder keine Alternative zum Neutron. Das Institut Laue-Langevin trägt Bahnbrechendes zum Erfolg der Neutronen-Methoden in der Biologie bei.

Grundlagen der Nachrichtenübertragung

NASA Astrophysics Data System (ADS)

Plaßmann, Wilfried

Die Nachrichtentechnik hat die Aufgabe, Nachrichten auszutauschen. Nachrichten sind z. B. Fragen, Beobachtungen und Befehle. Unter dem Begriff Nachrichtenübertragung wird hier die elektrische Nachrichtenübertragung verstanden, denn zur Übermittlung von Nachrichten werden Spannungen und Ströme sowie elektrische und magnetische Felder eingesetzt. Die Übertragung beginnt mit der Nachrichtenquelle, die die Nachrichten aussendet, und endet mit der Nachrichtensenke, die sie empfängt. Zwischen beiden liegt das elektrische Nachrichtenübertragungssystem, dessen Funktionseinheiten dargestellt sind und erläutert werden.

Die Grundlagen der Fernsehtechnik: Systemtheorie und Technik der Bildübertragung

NASA Astrophysics Data System (ADS)

Mahler, Gerhard

Umfassende Einführung in die Grundlagen der Bewegtbild-Übertragung von den Anfängen bis zum heutigen Stand des digitalen Fernsehens mit einer aus der Praxis entstandenen systemtheoretischen Analyse. Die kompakte und anschaulich bebilderte Darstellung mit elementaren mathematischen Beschreibungen macht es dem Leser leicht, sich in die Bildübertragungstechnik einzuarbeiten. Thematische Einheiten erweitern den Wissensstoff - u.a. zu den Themen visuelle Wahrnehmung, mehrdimensionale Signaldarstellung, Farbmetrik, Digitalisierung, Elektronenoptik - und zeigen deren Anwendung auf die elektronische Bildübertragung.

Qualität auf dem Prüfstand

NASA Astrophysics Data System (ADS)

Michaelis, Michael

An einem Wochenende im Dezember 2009 beendete der chinesische Eisenbahn-Vizeminister Hu Yadong in Begleitung einer hochrangigen Delegation aus Experten des Department of Safety seines Ministeriums eine mehrtägige Europareise mit einem Besuch in der Konzernzentrale des weltweit führenden Herstellers von Bremssystemen für Schienen- und Nutzfahrzeuge in München. Schon in wenigen Jahren wird China über die weltweit größte Flotte an Hochgeschwindigkeitszügen verfügen und dabei sind Sicherheit und Qualität vorrangige Anforderungen. Knorr-Bremse liefert 100% der Bremsanlagen dieser Züge und hat vor kurzem mit rund 500 Millionen Euro den größten Auftrag in der Firmengeschichte erhalten. Das Unternehmen wird zusammen mit seinen chinesischen Partnern insgesamt 2.720 neue Wagen des chinesischen Hochgeschwindigkeitszuges CRH3 mit Brems- und Türsystemen ausrüsten.

[Hepatitis E - More than a Rare Travel-Associated Infectious Disease!

PubMed

Wedemeyer, Heiner

2017-06-01

Übertragungswege  In Deutschland infizieren sich jedes Jahr wahrscheinlich mehr als 300 000 Menschen mit dem Hepatitis-E-Virus (HEV). Die Hepatitis E ist in Mitteleuropa in der Regel eine durch den zoonotischen HEV-Genotyp-3-verursachte autochthone, d. h. lokal erworbene Infektionskrankheit. Der Verzehr von nicht ausreichend erhitztem Schweine- oder Wildfleisch ist ein Hauptrisikofaktor für HEV-Infektionen, Übertragungen des Virus durch Bluttransfusionen sind aber auch möglich. Diagnostik  Bei Immunkompetenten kann die Diagnose einer akuten Hepatitis E mit dem Nachweis von anti-HEV-IgM gestellt werden. Serologische Tests können bei Immunsupprimierten aber falsch-negativ sein, weshalb in diesen Fällen eine HEV-Infektion nur durch den direkten Nachweis des Erregers mittels PCR im Blut oder Stuhl erfolgen sollte. Natürlicher Verlauf  Eine akute Hepatitis E kann bei Patienten mit anderen chronischen Lebererkrankungen zu einem Leberversagen führen. Chronische Verläufe, definiert durch eine Virämie von mind. 3 Monaten, sind bei Organtransplantierten mit immunsuppressiver Medikation beschrieben, können aber auch bei anderen Immundefizienzen auftreten. Eine chronische Hepatitis E kann innerhalb von Monaten zu einer fortgeschrittenen Leberfibrose oder zur Zirrhose führen. Extrahepatische Manifestationen  Extrahepatische Manifestationen können während und nach einer HEV-Infektion auftreten. Insbesondere Guillain-Barré-Syndrome und die neuralgische Schulteramyotrophie sind mit einer Hepatitis E assoziiert worden. Therapie  Ribavirin hat eine antivirale Wirksamkeit gegen HEV. Bei chronischer Hepatitis E sollte die Behandlung für 3 – 6 Monate durchgeführt werden. Therapieversagen und Rückfälle nach Beendigung einer Behandlung sind möglich. Ein Impfstoff gegen HEV ist bisher nur in China zugelassen.

Kanban - der Weg ist das Ziel

NASA Astrophysics Data System (ADS)

Aull, Florian; Berlak, Joachim; Dickmann, Eva; Dickmann, Philipp; Fischäder, Holm; Gerlach, Joachim; Henneberg, Jens; Kapalla, Klaus; Kress, Oliver; Kuttler, Robert; Schneider, Herfried M.; Schürle, Philipp; Stellpflug, Franz-Josef; Wannenwetsch, Ralph; Wulz, Johannes; Zäh, Michael F.

Wenn man aktuell Produktionsbereiche in Deutschland und Europa besucht, fallen im Zusammenhang mit modernen Produktionsmethoden immer öfter die Begriffe Kanban (jap. Karte, Signal) und Pull-Produktion, und dies nicht ohne Stolz, da diese mit dem schillernden Vorbild des Toyota Produktionssystems in Zusammenhang stehen. Tatsächlich ist Kanban ein integraler Bestandteil moderner Produktionssysteme. Blickt man aber im Rahmen von Prozessanalysen hinter die Fassaden", d. h. in die tägliche Praxis der Arbeitsprozesse, wird man schnell desillusioniert - die viel gepriesenen klassischen Kanban-Regeln werden im Tagesgeschäft nicht eingehalten.

Computerunterstütztes Modellieren mit Musiknetzen

NASA Astrophysics Data System (ADS)

Levens, Ulla

In der folgenden Ausführung geht es um eine Anwendung von Petri-Netzen im Bereich Musik. Ausgehend von der Implementierung einer speziellen Anwendung, dem Programmsystem ScoreSynth, wird das zugrundeliegende Konzept erläutert und anschließend an einem kleinen Beispiel veranschaulicht. Dieser Beitrag ist ein Auszug aus [Lev95b].

Geschichtlicher Überblick

NASA Astrophysics Data System (ADS)

Bölke, Klaus-Peter

Die Nachweise einer schadlosen Ableitung von Abwässern lassen sich bis weit in die Vergangenheit zurückverfolgen. Sie waren bereits zur damaligen Zeit eine Forderung zur Pflege der öffentlichen Reinlichkeit. Der Kanalisationsbau ist auch immer ein Ausdruck der Kultur eines Volkes gewesen. So kann festgestellt werden, dass im Zusammenhang mit der Hochkultur eines Volkes auch der Kanalbau ein vorherrschendes Thema war. Der Kanalbau steht auch in einem engen Zusammenhang mit dem Wasserleitungsbau. Es ist nur logisch, dass dort wo Wasser teilweise aus großer Entfernung herangeführt worden ist, dieses dann nach Gebrauch auch wieder schadlos beseitigt werden musste.

Ökophysik: Plaudereien über das Leben auf dem Land, im Wasser und in der Luft

NASA Astrophysics Data System (ADS)

Nachtigall, W.

Prof. em. Dr. rer. nat. Werner Nachtigall, geb. 1934, war als Zoophysiologe und Biophysiker Leiter des Zoologischen Instituts der Universität des Saarlandes in Saarbrücken. In Forschung und Ausbildung hat er sich insbesondere mit Aspekten der Technischen Biologie und Bionik befasst und mit seinen Forschergruppen viele Basisdaten insbesondere zur Ökologie, Physiologie und Physik des Fliegens und Schwimmens aber auch zur Stabilität beispielsweise der Gräser erarbeitet. Lebewesen überraschen immer wieder durch ihre "Biodiversität", ihre hochspezifischen Ausgestaltungen und Anpassungen.

Unfälle mit Kleintransportern

NASA Astrophysics Data System (ADS)

Tschirschwitz, Christian

Auf einer außerörtlichen Bundesstraße geriet ein mit vier Personen besetzter Pkw Toyota Corolla aus letztlich nicht vollständig geklärten Gründen ins Schleudern. Nachdem sich das Fahrzeug beträchtlich entgegen dem Uhrzeigersinn ausgedreht hatte, prallte ein entgegenkommender Kleintransporter VW T4 frontal an die rechte Flanke des Toyota. Der Transporter wurde gedreht, ausgehoben und durch einen Pkw Ford Escort unterfahren. Alle Fahrzeuge kamen in Kollisionsortnähe zum Endstand. Die vier Toyota-Insassen wurden getötet. Aus den anderen Fahrzeugen wurden sechs Personen überwiegend schwer verletzt. Unbeteiligte Zeugen waren nicht vorhanden.

Windkraftanlagen

NASA Astrophysics Data System (ADS)

Surek, Dominik

Windturbinenanlagen nutzen die kinetische Energie des Windes bei Geschwindigkeiten von c=4 m/s bis 25 m/s in Nabenhöhe des Windrades zur Stromerzeugung. Die oben genannten Windgeschwindigkeiten liegen im Grenzschichtbereich der ebenen Strömung (Abb. 67.1), die bei Höhen von h=100 m bis 1000 m liegen und in Großstädten mit Skylines bis 2000 m. Die größten Windturbinentürme erreichen gegenwärtig Nabenhöhen von h=160 m und Windraddurchmesser von d=130 m, d. h. mit Flügellängen von L=65 m. Die Windturbinen werden vorrangig mit 3 Schaufeln ausgeführt. Windturbinen mit einer und zwei Schaufeln waren Versuchsgeräte. Die Drehzahl von Windturbinen für Leistungen von P_{T}=2 MW betragen n=12 bis 20 min{}^{-1}. Das Windrad entzieht dem Wind mit der Anströmgeschwindigkeit c 1 nach Betz die Geschwindigkeitsdifferenz c2=(2/3) c1. Der Rest der Windgeschwindigkeit wird für die Abströmung des Windes im Leebereich c3=c1/3 benötigt. Durch den Entzug der Geschwindigkeit im Laufrad bläht sich der Abströmdurchmesser auf d3> d1 auf, der bei der Installation von Windturbinen zu beachten ist (Abb. 67.2) [Gasch und Twele(2013)]. Um die Windturbinen bei starkem Wind von c {}1> 25 m/s zu schützen, werden die Laufschaufeln durch Pitch- oder Stall-Anlagen aus dem Wind gedreht, so dass die Strömung an den Schaufeln abreißt und das Windrad in die Ruhestellung gelangt. Bei der Windgeschwindigkeit c1=25 m/s bis 34 m/s wird der Windrotor abgeschaltet. Die zulässige Maximalgeschwindigkeit liegt aus Festigkeitsgründen etwa bei . Die aktive Blattverdrehung (Pitchregelung) stellt eine Blattwinkelregelung dar, wobei die Profilnase in die Anströmung gedreht wird. Sie benötigen für die Drehzahlreduzierung keine mechanische Bremse.

Kompressionstherapie - Versorgungspraxis: Informationsstand von Patienten mit Ulcus cruris venosum.

PubMed

Protz, Kerstin; Heyer, Kristina; Dissemond, Joachim; Temme, Barbara; Münter, Karl-Christian; Verheyen-Cronau, Ida; Klose, Katharina; Hampel-Kalthoff, Carsten; Augustin, Matthias

2016-12-01

Eine Säule der kausalen Therapie bei Patienten mit Ulcus cruris venosum ist die Kompressionstherapie. Sie unterstützt die Abheilung, reduziert Schmerzen und Rezidive und steigert die Lebensqualität. Bislang existieren kaum wissenschaftliche Daten zu dem Versorgungsstand und fachspezifischem Wissen von Patienten mit Ulcus cruris venosum. Standardisierte Fragebögen wurden bundesweit in 55 Pflegediensten, 32 Arztpraxen, vier Wundzentren und -sprechstunden sowie einem Pflegetherapiestützpunkt von Patienten mit Ulcus cruris venosum bei Erstvorstellung anonym ausgefüllt. Insgesamt nahmen 177 Patienten (Durchschnittsalter 69,4 Jahre; 75,1 % Frauen) teil. Ein florides Ulcus cruris venosum bestand im Mittel 17 Monate. 31,1 % hatten keine Kompressionstherapie, 40,1 % Binden und 28,8 % Strümpfe. Bei der Bestrumpfung hatten 13,7 % Kompressionsklasse III, 64,7 % Kompressionsklasse II und 19,6 % Kompressionsklasse I. 70,6 % legten die Strümpfe nach dem Aufstehen an, 21,1 % trugen sie Tag und Nacht. 39,2 % bereiteten die Strümpfe Beschwerden. Lediglich 11,7 % hatten eine An- und Ausziehhilfe. Die Binden wurden im Mittel 40,7 Wochen getragen und bei 69 % nicht unterpolstert. Bei 2,8 % wurde der Knöchel- und Waden-Umfang zur Erfolgskontrolle gemessen. Venensport machten 45,9 %. Ein Drittel hatte keine Kompressionsversorgung, obwohl diese eine Basismaßnahme der Therapie des Ulcus cruris venosum ist. Zudem ist deren korrekte Auswahl und Anwendung angesichts der langen Bestandsdauer der Ulzerationen zu hinterfragen. Weiterführende Fachkenntnisse bei Anwendern und Verordnern sowie Patientenschulungen sind erforderlich. © 2016 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

Der Einfluss von Alitretinoin auf die Lebensqualität bei Patienten mit schwerem chronischen Handekzem: FUGETTA - Beobachtungsstudie unter Praxisbedingungen.

PubMed

Augustin, Matthias; Thaçi, Diamant; Kamps, Anja

2016-12-01

Alitretinoin ist die einzige zugelassene Behandlung für schweres chronisches Handekzem (CHE), das refraktär gegenüber potenten topischen Corticosteroiden ist. Bei dieser Studie (FUGETTA) wurde die Wirksamkeit von leitliniengerecht angewendetem oralem Alitretinoin sowie dessen Einfluss auf die Lebensqualität (LQ) bei Patienten mit schwerem refraktärem CHE beurteilt. Multizentrische, offene, nichtinterventionelle Beobachtungsstudie, durchgeführt in Deutschland. Die Patienten wurden nach Ermessen ihres behandelnden Arztes mit Alitretinoin 10 mg oder 30 mg einmal täglich über maximal 24 Wochen behandelt. Die Wirksamkeit wurde anhand des Physician Global Assessment (PGA) und des Dermatology Life Quality Index (DLQI) bewertet. Zudem wurden unerwünschte Ereignisse (UE) erfasst. Die Studienpopulation bestand aus 658 Patienten (30 mg: n = 581; 10 mg: n = 77). Bei Beobachtungsbeginn litten die meisten Patienten (83 %) gemäß PGA an einem schweren CHE. Bei Beobachtungsende war das Handekzem bei 48 % der Patienten gemäß PGA vollständig oder fast vollständig abgeheilt (30 mg: 49 %; 10 mg: 43 %). Die mittlere Verbesserung des DLQI-Scores in Woche 24 betrug 58 % (30 mg: mittlere [SD] Veränderung gegenüber dem Ausgangswert -10,4 [8,04]) und 70 % (10 mg: mittlere [SD] Veränderung gegenüber dem Ausgangswert -10,8 [7,29]). Die Gesamtinzidenz von NW war niedrig und in den beiden Gruppen ähnlich. Alitretinoin führte zu einer schnellen, deutlichen Verbesserung der LQ bei Patienten mit schwerem CHE. © 2016 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

Degradable Implantate: Entwicklungsbeispiele

NASA Astrophysics Data System (ADS)

Ruffieux, Kurt; Wintermantel, Erich

Resorbierbare Implantate werden seit mehreren Jahrzehnten in der Implantologie eingesetzt. Bekannt wurden diese Biomaterialien mit dem Aufkommen von sich selbst auflösenden Nahtfäden auf der Basis von synthetisch hergestellten Polylactiden und Polyglycoliden in den 70er Jahren. In einem nächsten Schritt wurden Implantate wie Platten und Schrauben zur Gewebefixation aus den gleichen Biomaterialien hergestellt.

Eine 200-μm-Kamera zur unvollständigen Himmelsdurchmusterung mit dem ISO-Satelliten.

NASA Astrophysics Data System (ADS)

Burgdorf, M.

The C200 camera designed for the wavelength range >160 μm is composed of the detector elements and their preamplifiers. The limiting sensitivity to be reached is estimated. In building the infrared satellite experiment ISOPHOT the detector arrays and selecting electronics are of key importance.

Smart Meter Rollout: Intelligente Messsysteme als Schnittstelle zum Kunden im Smart Grid und Smart Market

NASA Astrophysics Data System (ADS)

Vortanz, Karsten; Zayer, Peter

Das Gesetz zur Digitalisierung der Energiewende ist verabschiedet. Ab 2017 sind moderne Messeinrichtungen (mME) und intelligente Messsysteme (iMSys) zu verbauen und zu betreiben. Der "deutsche Weg" für die Einführung von Smart Metern sieht einen stufenweisen Rollout sowie ein Höchstmaß an Informations- und Datensicherheit vor. Dabei spielen iMSys und mME eine wichtige Rolle bei der Neugestaltung der intelligenten Netze (Smart Grids) und des neuen Marktmodells (Smart Market). Dieser Beitrag beschäftigt sich mit den neuen Gesetzen, den Marktrollen und ihren Aufgaben, Datenschutz und Datensicherheit, dem iMSys als sichere Lösung, dem sicheren Betrieb von Smart Meter Gateways, Smart Grid - Smart Market, dem Zusammenspiel zwischen reguliertem Bereich und Markt, den Einsatzbereichen der iMSys sowie den Auswirkungen auf Prozesse und Systeme und gibt Handlungsempfehlungen.

Intelligente Messsysteme - Mehrwert für unterschiedliche Stufen der Wertschöpfung

NASA Astrophysics Data System (ADS)

Deppe, Benjamin

Die Veränderung der Energiewirtschaft schreitet kontinuierlich voran - und wird mit Gesetz zur Digitalisierung der Energiewende nicht abgeschlossen sein. Vielmehr steigen die Innovationsgeschwindigkeit und die Erwartungshaltung der Kunden. Dieses Kapitel beschreibt, wie intelligente Messsysteme die Basis für neue Möglichkeiten schaffen und wie sich diese Veränderungen auf die Wertschöpfung auswirken. Der Fokus liegt dabei auf dem Wandel der einzelnen Wertschöpfungsstufen im Verlauf der Liberalisierung des Messwesens und dem seit dem 02.09.2016 verbindlichen Messstellenbetriebsgesetzes. Der Beitrag zeigt auf, wie sich bisher getrennte Wertschöpfungsstufen nunmehr direkt berühren und miteinander interagieren. Deutlich wird dadurch, wie Informationen zu Mehrwert führen können - aber auch, welche Fragen noch zu beantworten sind und welche Hürden es zu überwinden gilt.

[Leben im Eismeer - Tauchuntersuchungen zur Biologie arktischer Meerespflanzen und Meerestiere

PubMed

Lippert; Karsten; Wiencke

2000-01-01

Die Maske wird nochmals auf Dichtigkeit überprüft, der Knoten der Sicherungsleine mit zwei halben Schlägen fixiert, dann rutscht die Taucherin von der Eiskante in das kalte Wasser. Eine halbe Stunde vergeht, bevor ihr Kopf wieder aus dem Eisloch auftaucht und sie ein großes Sammelnetz nach oben reicht, gefüllt mit verschiedenen Arten von Makroalgen. Obwohl noch große Flächen des Kongsfjordes im arktischen Spitzbergen zugefroren sind und das Festland von einer dicken Schneedecke bedeckt ist, hat unter Wasser in den Algenwäldern bereits der Sommer und damit die Saison der Meeresbiologen begonnen.

Grundlagen der zeichnerischen Darstellung

NASA Astrophysics Data System (ADS)

Döring, Peter

Eine Technische Zeichnung muss nach DIN 6774 Teil 1 in der Weise angefertigt werden, dass sie übersichtlich, unmissverständlich, auch in verkleinertem Maßstab lesbar bleibt, kostengünstig reproduzierbar und dauerhaft archivierbar ist. Zu dem Zweck benötigt man entsprechendes Papier und angepasstes Zeichengerät. Heute ist die Anfertigung mit entsprechenden Rechnerprogrammen möglich.

Tokamak und Stellarator - zwei Wege zur Fusionsenergie: Fusionsforschung

NASA Astrophysics Data System (ADS)

Milch, Isabella

2006-07-01

Im Laufe der Fusionsforschung haben sich zwei Bautypen für ein zukünftiges Kraftwerk als besonders aussichtsreich erwiesen: Tokamak und Stellarator. Mit dem geplanten Tokamak-Experimentalreaktor ITER steht die internationale Fusionsforschung vor der Demonstration eines Energie liefernden Plasmas. Parallel soll die in Greifswald entstehende Forschungsanlage Wendelstein 7-X die Kraftwerkstauglichkeit des alternativen Bauprinzips der Stellaratoren zeigen.

B-Zell-Lymphome der Haut - Pathogenese, Diagnostik und Therapie.

PubMed

Nicolay, Jan P; Wobser, Marion

2016-12-01

Primär kutane B-Zell-Lymphome (PCBCL) beschreiben reifzellige lymphoproliferative Erkrankungen der B-Zell-Reihe, die primär die Haut betreffen. Die Biologie und der klinische Verlauf der einzelnen PCBCL-Subtypen variieren untereinander stark und unterscheiden sich grundsätzlich von primär nodalen und systemischen B-Zell-Lymphomen. Primär kutane Marginalzonenlymphome (PCMZL) und primäre kutane follikuläre Keimzentrumslymphome (PCFCL) werden auf Grund ihres unkomplizierten Verlaufs und ihrer exzellenten Prognose zu den indolenten PCBCL gezählt. Demgegenüber stellen die diffus großzelligen B-Zell-Lymphome, hauptsächlich vom Beintyp (DLBCL, LT) die aggressiveren PCBCL-Varianten mit schlechterer Prognose dar. Für die Ausbreitungsdiagnostik und die Therapieentscheidung sind eine genaue histologische und immunhistochemische Klassifizierung sowie der Ausschluss einer systemischen Beteiligung in Abgrenzung zu nodalen oder systemischen Lymphomen notwendig. Die Diagnostik sollte dabei durch molekularbiologische Untersuchungen unterstützt werden. Therapeutisch stehen für die indolenten PCBCL primär operative und radioonkologische Maßnahmen im Vordergrund sowie eine Systemtherapie mit dem CD20-Antikörper Rituximab bei disseminiertem Befall. Die aggressiveren Varianten sollten in erster Linie mit Kombinationen aus Rituximab und Polychemotherapieschemata wie z. B. dem CHOP-Schema oder Modifikationen davon behandelt werden. Auf Grund der in allen seinen Einzelheiten noch nicht vollständig verstandenen Pathogenese und Biologie sowie des begrenzten Therapiespektrums der PCBCL besteht hier, speziell beim DLBCL, LT, noch erheblicher Forschungsbedarf. © 2016 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

Sicherung mathematischer Grundkompetenzen am Beispiel des österreichischen Zentralabiturs

NASA Astrophysics Data System (ADS)

Peschek, Werner

Der österreichische Nationalrat (Parlament) hat im Sommer 2009 eine Neugestaltung der Reifeprüfung (Abitur) beschlossen; die wesentlichste Änderung besteht darin, dass die Aufgabenstellungen der für alle Schülerinnen und Schüler verbindlichen schriftlichen Reifeprüfung (sRP) in den Fächern Deutsch, Mathematik und einer lebenden Fremdsprache zentral und nicht wie bisher durch die jeweilige Klassenlehrerin bzw. den Klassenlehrer erfolgen. Für die Allgemeinbildenden Höheren Schulen ("Gymnasien") soll diese neue Regelung ab dem Schuljahr 2013/14 gelten, für die Berufsbildenden Höheren Schulen (u. a. höhere technische oder kaufmännische Schulen mit Abitur) ab dem Schuljahr 2014/15.

Digitalisierung des Bösen: Energiewirtschaft als Cyberopfer

NASA Astrophysics Data System (ADS)

Bartsch, Michael; Frey, Stefanie

Die Energieversorgung ist eine kritische Infrastruktur, da alle anderen Sektoren von der Stromversorgung abhängig sind und eine Störung katastrophale Auswirkungen mit unvorhersehbaren Kaskadeneffekten mit sich bringen würde. Das oberste Ziel der Betreiber ist daher sicherzustellen, dass Maßnahmen für eine störungsfreie Stromversorgung ergriffen werden. Cyberangriffe stellen ein hohes Risiko für die Energieversorgung dar. Dabei kann die Energiewirtschaft von Massenphänomenen wie Cybercrime betroffen sein, aber auch Gegenstand von technisch komplexer Cybersabotage werden, wie bei dem Angriff Ende 2015 auf einen ukrainischen Energieversorger. Die Stromversorgung fiel für mehrere Stunden aus und hatte weitreichende Auswirkungen für die Bevölkerung und Unternehmen.

Turbulenzübergang in der Rohrströmung: Die Lösung eines alten Rätsels

NASA Astrophysics Data System (ADS)

Eckhardt, Bruno; Hof, Björn; Faisst, Holger

2006-09-01

Die Strömung von Flüssigkeiten und Gasen durch eine Röhre kann zwei Zustände annehmen. Einer ist laminar, also gleichmäßig geordnet, einer ist zeitlich-räumlich verwirbelt und turbulent. Mit dem Übergang zur Turbulenz nimmt der Strömungswiderstand drastisch zu. Vor etwa 120 Jahren beschrieb Osborne Reynolds bereits das Verhalten der Rohrströmung sehr genau. Er beobachtete, dass der Turbulenzübergang sehr empfindlich von äußeren Störungen abhängt, was bislang rätselhaft blieb. Dieses Rätsel konnte nun mit einer Kombination aus Computerstudien, Konzepten aus der nichtlinearen Dynamik und speziell entwickelten Experimenten gelöst werden.

Quantitative Analyse und Visualisierung der Herzfunktionen

NASA Astrophysics Data System (ADS)

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.

Der deutsche Röntgensatellit ABRIXAS: Mission und wissenschaftliche Zielsetzung.

NASA Astrophysics Data System (ADS)

Predehl, P.

ABRIXAS (A BRoad band Imaging X-ray All-sky Survey) ist ein Röntgensatellit mit sieben 27-fach genesteten Wolterteleskopen, die sich in ihren Brennpunkten eine pn-CCD Kamera teilen. ABRIXAS soll im Frühjahr 1999 auf einer russischen Cosmos-Rakete gestartet werden und die erste abbildende Himmelsdurchmusterung oberhalb von 2.4 keV durchführen. Man erwartet während der dreijährigen Mission wenigstens 10.000 neue Röntgenquellen zu entdecken. Dies sind vor allem solche Quellen, die durch vorgelagerte Staub- und Gasschichten für den ABRIXAS-Vorgänger ROSAT unsichtbar blieben. Darüber hinaus wird ABRIXAS hervorragend geeignet sein, ausgedehnte, diffuse Quellen spektroskopisch zu studieren und Intensitätsvariationen von Röntgenquellen auf sehr unterschiedlichen Zeitskalen zu untersuchen. Das Projekt ist eine wissenschaftliche Zusammenarbeit zwischen dem Astrophysikalischen Institut Potsdam (AIP), dem Institut für Astronomie und Astrophysik der Universität Tübingen (IAAT) und dem Max-Planck-Institut für extraterrestrische Physik (MPE).

Ein Kredit für Weihnachtsbaumkugeln

NASA Astrophysics Data System (ADS)

Tutsch, Sina

Eine Mathematikerin aus dem DFG-Forschungszentrum Matheon arbeitet an Methoden zur dreidimensionalen Visualisierung. Sie hat die Geschäftsidee, Weihnachtsbaumkugeln mit bewegten Hologrammen herzustellen, die sich individuell gestalten lassen, und plant eine Existenzgründung. Aus einem öffentlichen Förderprogramm erhält sie ein günstiges Darlehen in Höhe von 50 000 Euro. Für die Startphase ihres Unternehmens benötigt sie jedoch den vierfachen Betrag.

Experimente ueber den Einflusse von Metaboliten und Antimetaboliten am Modell von Trichomonas Vaginalis. I. Mitteilung Experimente mit dem Vitamin B2-Komplex (Experiments on the Influence of Metabolites and Antimetabolites on the Model of Trichomonas vaginalis. I. Communication: Experiments with the Vitamin-B2-Complex),

DTIC Science & Technology

pathogenic protozoa Trichomonas vaginalis have been studied. Material and methods are described in the paper. The efficacy of the individual admixtures from the vitamin-B2-complex is subsequently discussed. (Author)

Zufällige Signale

NASA Astrophysics Data System (ADS)

Plaßmann, Wilfried

Die hier betrachteten Signale werden auch als stochastische Signale bezeichnet. Sie sind zufällig, d. h. ihr Augenblickswert ist nicht vorhersagbar. Abb. 118.1 zeigt eine Unterteilung nach den Signaleigenschaften. Über die nichtstationären Signale lässt sich keinerlei Aussage machen, und sie werden hier deshalb auch nicht weiter betrachtet. Für die stationären Signale gilt, dass ihr Momentanwert zwar auch nicht vorhergesagt werden kann, dass sie aber trotzdem gewisse auswertbare Eigenschaften besitzen, die allerdings statistischer Art sind und deshalb nur mit den Gesetzen der Wahrscheinlichkeitstheorie erfasst werden können. Zwar sind - theoretisch - für die Anwendung der Wahrscheinlichkeitstheorie unendlich viele Probenwerte zu nehmen, in der Praxis hat sich aber gezeigt, dass man auch mit einer endlichen Anzahl dem gesuchten Wert schon ausreichend nahe kommen kann.

Die nuklearen Anlagen von Hanford (1943-1987) Eine Fallstudie über die Schnittstellen von Physik, Biologie und die US-amerikanische Gesellschaft zur Zeit des Kalten Krieges

NASA Astrophysics Data System (ADS)

Macuglia, Daniele

Die Geschichte des Kalten Krieges eröffnet viele Möglichkeiten, sich näher mit den Schnittstellen von Physik und Biologie während des 20. Jahrhunderts zu befassen. Nicht nur das Unglück in Tschernobyl aus dem Jahr 1986, auch das Beispiel der nuklearen Anlagen in Hanford in den Vereinigten Staaten zeigt die biologischen Folgen von nuklearer Physik.

Kombinierte Hoch-/Niedrig-Dosis-Therapie mit systemischen Glukokor-tikoiden bei schweren Verlaufsformen der Alopecia areata im Kindesalter.

PubMed

Jahn-Bassler, Karin; Bauer, Wolfgang Michael; Karlhofer, Franz; Vossen, Matthias G; Stingl, Georg

2017-01-01

Schwere Verlaufsformen der Alopecia areata (AA) im Kindesalter sind aufgrund limitierter Optionen therapeutisch herausfordernd. Systemische, hochdosierte Glukokortikoide weisen die schnellste Ansprechrate auf, nach dem Absetzen kommt es allerdings zu Rezidiven. Eine längerfristige Hochdosis-Anwendung ist aufgrund der zu erwartenden Nebenwirkungen nicht empfehlenswert. Eine dauerhafte Steroiderhaltungstherapie unterhalb der Cushing-Schwellen-Dosis nach Bolustherapie könnte die Krankheitsaktivität ohne Nebenwirkungen längerfristig unterdrücken. Im Rahmen einer offenen Anwendungsbeobachtung wurden 13 Kinder mit schweren Formen der AA in diese Studie eingeschlossen. Bei sieben Kindern lag eine AA totalis/universalis vor, bei sechs eine multifokale AA mit Befall von mehr als 50 % der Kopfhaut. Das Therapieregime sah eine initiale Prednisolon-Dosierung von 2 mg/kg Körpergeweicht (KG) vor und wurde innerhalb von neun Wochen auf eine Erhaltungsdosierung unter der individuellen Cushing-Schwelle reduziert. Der Nachbeobachtungszeitraum betrug ein bis drei Jahre. Wir beobachteten in 62 % aller Fälle ein komplettes Nachwachsen der Haare. Die mittlere Dauer bis zum Ansprechen lag bei 6,6 Wochen und konnte mit der Erhaltungstherapie über den gesamten Beobachtungszeitraum aufrechterhalten werden. An Nebenwirkungen wurden ausschließlich eine Gewichtszunahme (1-3 kg) bei allen Behandelten sowie eine milde Steroidakne in 23 % der Fälle beobachtet. Die kombinierte Hoch-/Niedrig-Dosis-Therapie mit systemischen Glukokortikoiden mittels Prednisolon zeigte eine hohe, dauerhafte Ansprechrate ohne signifikante Nebenwirkungen. © 2017 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

Statistik in Naturwissenschaft und Technik

NASA Astrophysics Data System (ADS)

Wilrich, Peter-Theodor

Mit dem Aufschwung von Naturwissenschaft und Technik zu Beginn des 19. Jahrhunderts entstand die mathematische Statistik, angeregt aus der Geodäsie (wie die Methode der kleinsten Quadrate) und der Anthropologie (wie die statistische Analyse mehrdimensionaler Beobachtungen und ihrer stochastischen Abhängigkeiten). Im Gegensatz zu den Wirtschafts- und Sozialwissenschaften, in denen Daten vorwiegend aus Beobachtungsstudien gewonnen werden, stehen in den Naturwissenschaften Experimente im Vordergrund. Daher gehört die statistische Versuchsplanung zu den insbesondere in Naturwissenschaft und Technik angewendeten statistischen Methoden, aber auch die Extremwertstatistik und Lebensdaueranalysen sowie die Methoden der räumlichen Statistik (insbesondere in der Umweltforschung). Im 20. Jahrhundert wurden Stichprobenpläne und Regelkarten (Kontrollkarten) zur Prozessregelung als Hilfsmittel der statistischen Qualitätssicherung entwickelt. Diese Methodenbündel, mit denen sich der Ausschuss Statistik in Naturwissenschaft und Technik immer wieder befasst, werden im Folgenden vorgestellt.

Individuelle Templates für Rekonstruktionen des linken Herzventrikels

NASA Astrophysics Data System (ADS)

Feder, Stefan; Falk, Volkmar; Gutberiet, Matthias; Bartz, Dirk

Bei krankhaften Vergrößerungen des linken Herzventrikels kann eine chirurgische Ventrikelrekonstruktion zur Verbesserung der Herzleistung beitragen. Die dabei erstellte Ventrikelgeometrie ist von entscheidender Bedeutung. Diese Studie befasst sich mit der computerbasierten Planung von individuellen Schablonen (Templates) für Ventrikelrekonstruktionen. Ziel ist es aus Cardio-CT-Daten, präoperativ, patientenindividuelle 3D-Modelle für Ventrikeltemplates zu erstellen. Hierfür wird aus CT-Daten der linksventrikuläre Blutpool segmentiert und daraus das Ventrikeltemplate modelliert. Dies geschieht anhand von zwei Kriterien: dem physiologischen Ventrikelfüllungsvolumen und der hämodynamisch günstigen ellipsoiden Form. Es konnten 20 3D-Templatemodelle mit einem durchschnittlichen Volumen von 144 ml erstellt werden. Die ellipsoide Form konnte durch manuelle Modellierung erreicht werden. Der Nachweis verbesserter Operationsergebnisse muss in nachfolgenden klinischen Studien erbracht werden.

Himmelsfotografie MIT Schmidt-Teleskopen

NASA Astrophysics Data System (ADS)

Marx, Siegfried; Pfau, Werner

Auf dem Höhepunkt der Verbreitung und astronomischen Anwendung von Schmidt-Teleskopen legen S. Marx und W. Pfau einen reich illustrierten Bildband zu diesem Fernrohrtyp vor. Der thematische Bogen reicht von der Teleskoptechnik und ihrer Geschichte über das Leben von Berhard Schmidt bis zu den schönsten, hier in hervorragender Qualität wiedergegebenen Himmelsaufnahmen und ihrer wissenschaftlichen Interpretation. Praktische Hinweise zu eigener fotografischer Tätigkeit und ein Glossar machen das Buch nützlich für jeden Liebhaber der Himmelskunde.

Mathematisches Bewusstsein

NASA Astrophysics Data System (ADS)

Kaenders, Rainer; Kvasz, Ladislav

Wenn jemand sagt, dass ein Bus um 9 Uhr abfährt - weiß man es dann? Angenommen, man ist darüber unterrichtet, dass die Busse unter der Woche immer zur vollen Stunde abfahren - von 7 Uhr morgens bis 7 Uhr abends, weiß man es dann mit dem Wissen um diese allgemeine Regel besser, dass der Bus um 9 Uhr abfährt? Macht es einen Unterschied, ob man den Fahrplan erstellt, den Bus lenkt oder nur mitfährt, um sich dieser Tatsache bewusst zu sein?

Anbindung des SISIS-SunRise-Bibliothekssystems an das zentrale Identitätsmanagement

NASA Astrophysics Data System (ADS)

Ebner, Ralf; Pretz, Edwin

Wir berichten über Konzepte und Implementierungen zur Datenprovisionierung aus den Personenverwaltungssystemen der Technischen Universität München (TUM) über das zentrale Metadirectory am Leibniz-Rechenzentrum (LRZ) in das SISIS-SunRise-Bibliothekssystem der Universitätsbibliothek der TUM (TUB). Es werden drei Implementierungsvarianten diskutiert, angefangen von der Generierung und Übertragung einfacher CSV-Dateien über ein OpenLDAP-basiertes Konzept als Backend für die SISIS-Datenbank bis zur endgültigen Implementierung mit dem OCLC IDM Connector.

STF Optimierung von single-bit CT ΣΔ Modulatoren basierend auf skalierten Filterkoeffizienten

NASA Astrophysics Data System (ADS)

Widemann, C.; Zorn, C.; Brückner, T.; Ortmanns, M.; Mathis, W.

2012-09-01

Die vorliegende Arbeit beschäftigt sich mit dem Signalübertragungsverhalten von single-bit continuous-time (CT) ΣΔ Modulatoren. Dabei liegt der Fokus der Untersuchung auf dem Peaking der Signaltransferfunktion (STF). Dieser Effekt kann die Performance und die Stabilität des Gesamtsystems negativ beeinflussen, da bei auftretendem STF-Peaking Signale außerhalb des Signalbands verstärkt werden. In dieser Arbeit wird ein neuer Ansatz zur Reduktion des Peakings vorgestellt, der auf der Optimierung der Systemdynamik basiert. Dabei werden die Filterkoeffizienten des Modulators systematisch angepasst. Anhand eines Beispielsystems wird gezeigt, dass der Ansatz genutzt werden kann, um das Übertragungsverhalten des Modulators abhängig vom Ausgangssystem zu verändern. So kann entweder die Systemsperformance verbessert werden, ohne Peaking in der STF zu erzeugen, oder das STF-Peaking reduziert werden, ohne die Systemperformance stark zu beeinflussen.

Veränderungsmanagement: Utility 4.0

NASA Astrophysics Data System (ADS)

Hofstetter, Norbert

Finden Sie das rechte Maß für Ihre energiewirtschaftlichen Veränderungsvorhaben in "Utility 4.0". Mal was Gutes für Ältere: "Alter Dachs schlägt jungen Hasen". Beim Veränderungsmanagement ist Erfahrung gefragt. Die Bausteine der Veränderung reichen von wie sie mit ihrer Veränderungsgeschichte überzeugen bis wie sie die emotionale Achterbahn der Gefühle auf der individuellen Veränderungskurve bewältigen und wie Veränderungsprojekte auf Gesamtunternehmensebene ablaufen bis zur Frage, wie sie Ihre Macht-/Fachpromotoren und Multiplikatoren in Stellung bringen. Möglicherweise haben Sie die Veränderung in Form eines Start-up-ähnlichen Organisational Slack schon in Ihrem Haus. Nur wissen Sie es noch nicht. Und last but not least: Beschäftigen sie sich mit dem Thema Komplexitätshandhabung. Seien Sie es sich selbst Wert. Seien sie aufmerksam zu sich und ihrer Gesundheit!

Analyse der pharmazeutischen Versorgungssituation von Patienten mit Psoriasis-Arthritis auf Basis von Routinedaten der Gesetzlichen Krankenversicherung.

PubMed

Sondermann, Wiebke; Ventzke, Julia; Matusiewicz, David; Körber, Andreas

2018-03-01

Die Psoriasis-Arthritis (PsA) gehört zu den chronisch entzündlichen Gelenkerkrankungen. Trotz zahlreicher versorgungswissenschaftlicher Studien in Deutschland liegen zur pharmazeutischen Versorgungssituation von PsA-Patienten bisher kaum aktuelle Ergebnisse vor. Mit Hilfe einer systematischen Literaturrecherche sowie anhand von Routinedaten der Allgemeinen Ortskrankenkasse (AOK) Rheinland/Hamburg wird ein aktueller Überblick über die pharmazeutische Versorgung von PsA-Patienten in Deutschland gegeben. Selektiert wurden Versicherte aus dem ambulanten und stationären Bereich, die im 1. und 2. Quartal des Jahres 2014 die gesicherte Abrechnungsdiagnose Psoriasis-Arthritis L40.5+ aufwiesen. Anschließend wurden auf Basis dieser "vorab definierten" Kohorte die Arzneimitteldaten für 5 Jahre (01.01.2010-31.12.2014) abgerufen. Es konnten insgesamt n  =  3205 Versicherte (45 % männlich, 55 % weiblich) der AOK Rheinland/Hamburg mit einer gesicherten PsA-Diagnose selektiert werden. Das Durchschnittsalter betrug 58,9 Jahre. 53,7 % der PsA-Patienten wurden mit systemischen PsA-relevanten Arzneimitteln versorgt. Nichtsteroidale Antirheumatika (NSAR) wurden am häufigsten verordnet, gefolgt von systemischen Glucocorticoiden. Von den selektierten PsA-Patienten, die eine Systemtherapie erhielten, wurden 72,1 % mittels einer Disease-modifying-antirheumatic-Drug (DMARD)-Monotherapie behandelt, gefolgt von der Kombinationstherapie aus DMARDs und Biologika (20,9 %). Die pharmakologische Therapie der PsA muss eine Gewährleistung zwischen adäquater Versorgung der PsA mit Verhinderung der Krankheitsprogression und ökonomischer Verantwortung darstellen. © 2018 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

Sentinel-Lymphknoten-Biopsie des Melanoms mittels Indocyaningrün und "FOVIS"-System.

PubMed

Göppner, Daniela; Nekwasil, Stephan; Jellestad, Anne; Sachse, Alexander; Schönborn, Karl-Heinz; Gollnick, Harald

2017-02-01

Der Nachweis metastatischer Infiltrate im Sentinel-Lymphkoten (SLN) gilt als wesentlicher prognostischer Faktor des Melanoms. Alternativ zur Farbstoffmethode mit Patentblau zum Goldstandard der SLN-Biopsie (SLNB) mittels Radiokolloid wird die fluoreszenzoptische Darstellung mit Hilfe von Indocyaningrün (ICG) und Nahinfrarot (NIR)-Kamerasystem kommuniziert. Im Vergleich zur konventionellen Methode wurde die Wertigkeit des ICG-/NIR-Verfahrens in Abhängigkeit vom Body-Mass-Index (BMI) des Patienten und der Konzentration von ICG bezüglich der Visualisierung des Lymphabstroms und des SLNs untersucht. An zehn Patienten wurde die SLNB mittels Technetium-99m, Patentblau und ICG durchgeführt. Die Fluoreszenz-Darstellung von Lymphbahnen und SLN erfolgte in Echtzeit mittels der NIR-Kameratechnik "FOVIS". Je nach erzielter Bildqualität wurde ICG in einer Dosis von 0,25 mg bis 2,5 mg intrakutan appliziert. Neun der zehn SLN wurden fluoreszenzoptisch identifiziert (90 %), alle zehn radioaktiv (100 %), nur acht (80 %) mittels ICG-Grünfärbung bzw. Patenblau-Markierung. Transdermal wurde ein SLN dargestellt (10 %). In Korrelation zum BMI waren höhere ICG-Mengen, bis zu 2,5 mg intrakutan absolut, in der Darstellung der Lymphbahnen von Vorteil. Die SLN-Fluoreszenzmarkierung mit dem ICG/NIR-Kamera-System "FOVIS" stellt eine sichere Alternative zur Farbstoffmethode mit Patentblau ergänzend zur Radiokolloidmethode mit Technetium-99m dar. Weitere Studien zur optimalen Dosierung von ICG und transdermalen Bildgebung in Relation zum BMI sind notwendig. © 2017 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

Grundlegende Steuerungsverfahren im heterogenen Logistiknetz mit Kanban

NASA Astrophysics Data System (ADS)

Dickmann, Eva; Dickmann, Philipp; Lödding, Hermann; Möller, Niklas; Rücker, Thomas; Schneider, Herfried M.; Zäh, Michael F.

In vielen Unternehmen werden heterogene (verschiedene) Steuerungen in einem abgestimmten Konzept kombiniert. Je nach Anwendungsfall und Rahmenbedingungen werden Kombinationen allgemein bekannter Steuerungen oder Steuerungsvarianten gemischt eingesetzt, um eine optimale Steuerung für unterschiedliche Fälle zu erreichen. Hierbei stehen neben den bekannten und weit verbreiteten Methoden, wie Material Requirements Planning (MRP) oder Kanban, auch weniger bekannte oder neue Methoden zur Auswahl, wie die Produktionssteuerung mit dezentraler, bestandsorientierter Fertigungsregelung (DBF). Kanban ist ein simples und effizientes Steuerungskonzept, das in der klassischen Form für spezifische einfache Anwendungsfälle umsetzbar ist. Hochentwickelte Steuerungsalgorithmen können helfen, komplexe Abläufe optimal abzubilden. Mit einer grundlegenden Vereinfachung der Abläufe kann allerdings in vielen Fällen ein wesentlich stärkerer und umfassender Verbesserungseffekt erzielt werden. Die wesentliche Fragestellung sollte folglich lauten: Warum ist der Ablauf nicht mit einer einfachen Steuerung wie Kanban abzubilden? Um die Vorteile des Konzepts auch in untypischen Bereichen anwenden zu können, sind jedoch verschiedene Varianten oder Kanban-ähnliche Steuerungsmethoden entstanden. Darüber hinaus sind in der Praxis hybride Steuerungen im Einsatz, welche so kombiniert werden, dass die Zusammensetzung anspruchsvolle Eigenschaftsbilder noch exakt abbildet. In der Praxis basieren die Steuerungsentscheidungen nur zu einem kleinen Teil auf den eigentlichen Steuerungsalgorithmen, wie sie uns das MRP-System zur Verfügung stellt. Moderne Steuerungswelten" schließen alle relevanten Informationsquellen in eine heterogene Entscheidungsmatrix mit ein. Letztlich zählt nicht, ob die Entscheidung auf den Informationen aus dem MRP-System oder auf Softfacts basierend getroffen wurde, sondern nur, ob die Entscheidung erfolgreich war.

PubMed

Wildner, Manfred

2018-06-01

„Ich habe doch nur mit dem Finger gedroht“, sagte der Angeklagte, und unterließ es unfairerweise darauf hinzuweisen, dass dieser am Abzug einer Pistole gelegen hatte. Der Bezug dieses Bonmots zum Gesundheitswesen soll im Folgenden weniger auf die konkreten gesundheitlichen Risiken durch Schusswaffen gelegt werden, sondern vielmehr auf die nicht weniger bedeutsame Rolle des Kontextes für Gesundheit, Krankheit und Wohlbefinden. Dass der „Kontext“, verstanden als System- und Sinnzusammenhang, sowohl das objektive Auftreten von Krankheiten in ihrer Häufigkeit und Schwere als auch das subjektive Erleben von Gesundheitszuständen beeinflusst, ist hinreichend bekannt.

Symmetriebrechung und Emergenz in der Kosmologie.

NASA Astrophysics Data System (ADS)

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.

[Homöopathisch-phytotherapeutische Behandlung des Reizdarmsyndroms mit Magen-Darm-Entoxin N®: Eine Anwendungsbeobachtung].

PubMed

Märtens, Diane; Range, Natasha; Günnewich, Nils; Gruber, Nicola; Schmidt, Stefan

Hintergrund: In dieser Anwendungsbeobachtung wird zum ersten Mal die Behandlung des Reizdarmsyndroms (RDS) mit einem homöopathisch-phytotherapeutischen Komplexpräparat beschrieben. Methodik: Ziel der 6-wöchigen Therapie mit dem Magen-Darm-Entoxin N® war die Reduzierung der RDS-Symptomatik sowie die Verbesserung der Lebensqualität. Zielkriterien waren die Veränderungen in der Irritable Bowel Syndrome - Severity Scoring System (IBS-SSS) und der Irritable Bowel Syndrome - Quality-of-Life Scale (IBS-QoL). Die Patient/innen (N = 41; Alter 44,0 ± 15,74 Jahre) wurden zu gleichen Teilen in einer Hausarztpraxis (N = 20) und einer Heilpraktikerpraxis (N = 21) rekrutiert. Ergebnisse: Der IBS-QoL-Score verringerte sich signifikant (prä: 35,9 ± 16,3; post: 20,1 ± 13,4; t = 8,504; p < 0,001). Die Effektstärke betrug 1,34 (Cohens d). Der IBS-SSS-Score verringerte sich ebenfalls signifikant (prä: 239,4 ± 83,4; post: 123,7 ± 80,9; t = 7,825; p < 0,001) mit einer Effektstärke von d = 1,24. Die Neben- und Wechselwirkungen waren minimal und signifikante Unterschiede zwischen beiden Praxen wurden nicht gefunden. Schlussfolgerungen: Magen-Darm-Entoxin N® ist eine sichere und sinnvolle Therapieoption bei der Behandlung des RDS. Allerdings sollten randomisierte kontrollierte Studien folgen, um die Spezifizität der Ergebnisse dieser Anwendungsbeobachtung zu stützen. © 2017 S. Karger GmbH, Freiburg.

Sternbilder und ihre Mythen

NASA Astrophysics Data System (ADS)

Fasching, Gerhard

Die Sternbilder, die seit alters her die Menschen in ihren Bann gezogen haben, und die damit verbundenen Mythen werden in zweifacher Weise vorgestellt. Erstens ist es die Absicht, dem Leser zu helfen, sich am Sternenhimmel zurechtzufinden, und zweitens will es ihm die Vielfalt der Bilder vermitteln, die damit verbunden sind. Am Anfang des Buches stehen die prächtigen Erzählungen aus Ovids Metamorphosen. Dann ist vom Sternenhimmel im Jahreskreis die Rede, um den Leser anzuregen, diesen fast unendlichen Bilderreichtum sich selbst durch eigene Beobachtungen zu erschließen. Ein umfangreicher Abschnitt behandelt die einzelnen Sternbilder und das hierzu überlieferte Wissen. Sternkarten und alte Kupferstiche aus dem Bestand der Österreichischen Nationalbibliothek zeigen, wie man sich in früheren Jahrhunderten den Sternenhimmel vorgestellt hat. Sternsagen und Mythen werden erzählt und auch das ptolemäische und das kopernikanische Weltsystem werden einander gegenübergestellt. Ausführliche Sachverzeichnisse mit über 3000 Suchbegriffen erleichtern den Zugang zu Stern- und Sternbildnamen und zur Mythologie.

Meilensteine in der Erforschung der kompakten Objekte

NASA Astrophysics Data System (ADS)

Camenzind, Max

Kompakte Objekte besitzen zum einen eine sehr hohe Dichte, und zum anderen sind sie durch die Tatsache charakterisiert, dass keine nuklearen Reaktionen mehr in ihrem Inneren stattfinden können. Aus diesem Grund können sie im Unterschied zu gewöhnlichen Sternen der Gravitation nicht mehr mit dem Druck des thermischen Gases widerstehen. In den Weißen Zwergen bzw. Neutronensternen wird der Gravitation der Quantendruck eines Elektronengases bzw. einer Neutronenflüssigkeit entgegengesetzt. Ein solches Gas besteht aus Elektronen bzw. Neutronen, die auf ihr niedrigstes Energieniveau zusammengepresst wurden. Durch die daraus resultierende hohe Bewegungsenergie der Fermionen wird der sogenannte Quantendruck erzeugt.

Sternbilder und ihre Mythen

NASA Astrophysics Data System (ADS)

Fasching, Gerhard

Die Sternbilder und die damit verbundenen Mythen helfen, sich am Sternenhimmel zurechtzufinden und vermitteln die Vielfalt der Bilder der Mythologie und der Sternsagen. Sternkarten und alte Kupferstiche aus dem Bestand der Österreichischen Nationalbibliothek zeigen, wie man sich in früheren Jahrhunderten den Sternenhimmel vorgestellt hat. Ausführliche Sachverzeichnisse mit über 3000 Suchbegriffen erleichtern den Zugang zu Stern- und Sternbildnamen und zur Mythologie. Die dritte, erweiterte Auflage gibt für die kommenden Jahrzehnte darüber Auskunft, wo und wann die Planeten aber auch Sternhaufen, Gasnebel und Galaxien am Himmel mühelos aufgefunden werden können.

Neue Laser und Strahlquellen - alte und neue Risiken?

PubMed

Paasch, Uwe; Schwandt, Antje; Seeber, Nikolaus; Kautz, Gerd; Grunewald, Sonja; Haedersdal, Merete

2017-05-01

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 Optionen für den Dermatologen erschlossen werden konnten. Wurden bisher zum Beispiel mit fraktionalen Lasern Falten behandelt, sind eben diese Systeme heute in Kombination mit Medikamenten wichtige Werkzeuge bei der Behandlung von Narben, bei Feldkanzerisierung und epithelialen Tumoren. Die Anforderungen an den die Indikation stellenden und vorzugsweise therapierenden Arzt steigen mit der immer komplexer werdenden Technik und den zunehmenden Komorbiditäten und Komedikationen einer älter werdenden Patientenklientel. Parallel etabliert wurden, zunächst für einige wenige Indikationen, Geräte für die Heimanwendung, die sich durch geringe Leistung und spezielle Sicherheitsvorkehrungen zur Vermeidung von Unfällen, Risiken und Nebenwirkungen auszeichnen. Trotz der reduzierten Effizienz solcher Selbstbehandlungsmaßnahmen steigt die Wahrscheinlichkeit einer Fehlanwendung, da die Grundvoraussetzung für eine korrekte Therapie, nämlich die exakte Diagnose und Indikationsstellung, nicht vorausgesetzt werden kann. Bei einer Haarentfernung können so Pigmenttumoren, bei einer Faltentherapie neoplastische Hautveränderungen adressiert und zu erwartende, unvorhergesehene und neue Nebenwirkungen und Komplikationen induziert werden. In diesem Szenario ist es wichtig, alle potenziellen Anwender dieser neuen Technologien vor deren Einsatz so zu qualifizieren, dass den Therapierten maximale Therapiesicherheit bei höchster Effizienz unter dem Leitbild diagnosis certa - ullae therapiae fundamentum garantiert wird. © 2017 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

[Kombinierte Anwendung von Strahlentherapie und adjuvanter Therapie mit einem Mistelextrakt (Viscum album L.) zur Behandlung des oralen malignen Melanoms beim Hund: Eine retrospektive Studie].

PubMed

von Bodungen, Uta; Ruess, Katja; Reif, Marcus; Biegel, Ulrike

2017-01-01

Hintergrund: Orale maligne Melanome (OMM) des Hundes zeichnen sich durch schnelles Wachstum, lokale Invasion und hohe Metastasierungsraten aus. Extrakte auf Basis von Viscum album L. (VAE) werden zunehmend in der Krebstherapie sowohl in der Human- als auch in der Veterinärmedizin eingesetzt. Ziel unserer Studie war es zu untersuchen, inwieweit die adjuvante Therapie mit VAE eine therapeutische Option zur Behandlung von OMM ist. Besonderes Augenmerk galt dabei der Überlebenszeit und möglichen Nebenwirkungen. Tiere und Methoden: 26 Hunde mit OMM, die in einem der größten veterinäronkologischen Zentren der Schweiz allesamt eine Strahlentherapie erhielten (teilweise nach operativer Tumorresektion) wurden in die retrospektive Studie eingeschlossen: 18 Hunde wurden mit VAE behandelt (1 ml VAE (Iscador®) in ansteigenden Konzentrationen von 0,1 bis 20 mg/ml subkutan 3-mal pro Woche (VAE-Gruppe), 8 erhielten keine adjuvante Behandlung (Vergleichsgruppe). Wir verglichen die Größenentwicklung der OMM sowie die Überlebenszeit. Ergebnisse: Patienten mit Bestrahlung und adjuvanter VAE-Therapie zeigten mit 236 Tagen eine signifikant längere mediane Überlebenszeit im Vergleich zu Patienten mit Bestrahlung, aber ohne adjuvante VAE-Therapie (49 Tage; Log-Rank-Test: p = 0,0047). Die VAE-Therapie verlängerte die Überlebenszeit um mehr als zwei Drittel (Hazard Ratio (HR) = 0,30, 95%-Konfidenzintervall (KI) 0,11-0,86; p = 0,024), während ein höheres Tumorstadium gemäß UICC (Union internationale contre le cancer) einen statistischen Trend zur Verdopplung des Sterberisikos zeigte (UICC-Stadium III/IV vs. I/II: HR = 2,12, 95%-KI 0,88-5,12; p = 0,095). Zwei Patienten zeigten milde Nebenwirkungen während der VAE-Behandlung. Einer der beiden zeigte 1 Tag lang ein selbstlimitiertes Fieber, bei dem anderen Patienten reduzierten wir die Dosis von einem konzentrierteren zu einem weniger konzentrierten VAE (Serie 0) aufgrund von Müdigkeit, die daraufhin verschwand. Schlussfolgerungen: VAE ist eine sichere, nebenwirkungsarme Behandlung und scheint sich positiv auf die Überlebenszeit von Hunden mit OMM auszuwirken. Somit ist dieser therapeutische Ansatz es wert, vermehrt bei der adjuvant zur Strahlentherapie eingesetzten Behandlung des OMM in Betracht gezogen zu werden. Die verglichenen Gruppen waren jedoch klein, divers und nicht konsistent hinsichtlich aller prognostischen Parameter. Eine prospektive Studie mit einer größeren Studienpopulation wäre daher von Interesse. © 2017 S. Karger GmbH, Freiburg.

Plattenepithelkarzinom in Verbindung mit einer roten Tätowierung.

PubMed

Schmitz, Inge; Prymak, Oleg; Epple, Matthias; Ernert, Carsten; Tannapfel, Andrea

2016-06-01

Obwohl Tätowierungen in den letzten Jahren außerordentlich beliebt geworden sind, wurde in der Literatur bisher nur über wenige Fälle schwerer Reaktionen berichtet, die zu einer malignen Transformation führten. Dies steht im Kontrast zu der praktisch unüberschaubaren Zahl an Tätowierungen weltweit. Die Zusammensetzung der für Tätowierungen verwendeten Farbstoffe variiert stark, und selbst gleiche Farbtöne können unterschiedliche Komponenten enthalten. Das Ziel unserer Studie war es zu untersuchen, auf welche Weise Tätowierungen möglicherweise Hautkrebs auslösen können. Wir berichten über den seltenen Fall einer 24-jährigen Frau, bei der sich sieben Monate nachdem sie eine Tätowierung auf dem Fußrücken erhalten hatte in unmittelbarer Nähe des verwendeten roten Farbstoffs ein Plattenepithelkarzinom entwickelte. Die Komplikationen begannen mit einer unspezifischen Schwellung. Die Läsion wurde histologisch untersucht. Die Zusammensetzung des inkorporierten Farbstoffs wurde mittels Rasterelektronenmikroskopie in Kombination mit energiedispersiver Elementanalyse analysiert. Zur weiteren Charakterisierung wurden Thermogravimetrie und Pulverdiffraktometrie eingesetzt. Der Tätowierungsfarbstoff enthielt hauptsächlich Bariumsulfat; Spuren von Al, S, Ti, P, Mg und Cl ließen sich ebenfalls nachweisen. Bei der Analyse zeigten sich Pigmentgranula unterschiedlicher Größe. In seltenen Fällen kann Tätowierungstinte karzinogene Effekte haben, die multifaktoriell zu sein scheinen. © 2016 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

Betriebsführung multimodaler Energiesysteme

NASA Astrophysics Data System (ADS)

Mackensen, Reinhard

Die Transformation des Energiesystems von einer zentral geprägten, unidirektional orientierten und in unterschiedliche Sektoren separierten Struktur hin zu einer umfassenden, multimodalen, dezentralen und flexiblen Erzeuger- und Verbraucherlandschaft findet auf verschiedenen Ebenen statt. Randbedingung bei dieser Umwälzung ist immer die Einhaltung der Teilziele Versorgungssicherheit, Wirtschaftlichkeit und Effizienz. Im Einzelnen schlägt sich diese Transformation in einer Diversifizierung der Akteurslandschaft durch die Mechanismen des Unbundling nieder. Weiterhin finden eine Dezentralisierung der Erzeugerlandschaft und damit eine Substitution von mehrheitlich fossil betriebener Großkraftwerkstechnologie durch eine Vielzahl dezentraler Erzeuger mit zumeist regenerativem Charakter statt. Dieser Wandel hat im Wesentlichen zwei Hauptkonsequenzen. Zum einen ergeben sich durch dezentrale, flächige Verteilung der Erzeuger neue Anforderungen an den Energieaustausch, bspw. aus der Erweiterung der Stromnetze für einen bidirektionalen Energieaustausch, zum anderen werden Abstimmungsmechanismen erforderlich, welche die fluktuierende Einspeisung derart mit dem Verbrauch in Waage hält, dass sowohl elektrische Netzrestriktionen, die Qualität der Versorgung und Aspekte der Energieeffizienz und damit der Wirtschaftlichkeit berücksichtigt werden. Mögliche Antworten auf die mit dieser Betrachtung einhergehenden Fragen liegen in der Konzeption eines multimodalen Energiesystems, also in der Gesamtbetrachtung der Sektoren Strom, Wärme und Verkehr. Dieses Kapitel soll Mechanismen darlegen und Wege aufzeigen, wie eine solche Konzeption gestaltet werden kann und wie solche komplexen Systeme in der Praxis betrieben werden können.

Haptische Modellierung und Deformation einer Kugelzelle

NASA Astrophysics Data System (ADS)

Schippritt, Darius; Wiemann, Martin; Lipinski, Hans-Gerd

Haptische Simulationsmodelle dienen in der Medizin in erster Linie dem Training operativer Eingriffe. Sie basieren zumeist auf physikalischen Gewebemodellen, welche eine sehr genaue Simulation der biomechanischen Eigenschaften des betreffenden Gewebes erlauben, aber gleichzeitig sehr rechenintensiv und damit zeitaufwändig in der Ausführung sind. Die menschliche Wahrnehmung kann allerdings auch eine ungenaue haptische Modellierung psychooptisch ausgleichen. Daher kann es sinnvoll sein, haptische Simulationen auch mit nicht vollständig physikalisch definierten Deformationsmodellen durchzuführen. Am Beispiel der haptischer Simulation einer in-vitro Fertilisation wird gezeigt, dass durch die Anwendung eines geometrischen Deformationsmodells eine künstliche Befruchtung unter realistischen experimentellen Bedingungen in Echtzeit haptisch simuliert und damit trainiert werden kann.

Segmentierung von Aortenaneurysmen in CTA-Bildern mit dem statistischen Verfahren der Active Appearance Models

NASA Astrophysics Data System (ADS)

Greiner, Katharina; Egger, Jan; Großkopf, Stefan; Kaftan, Jens N.; Dörner, Ralf; Freisleben, Bernd

In diesem Beitrag werden Active Appearance Models (AAMs) zur Segmentierung der äußeren Kontur von Aortenaneurysmen eingesetzt. Diese Aufgabe ist wegen des geringen Kontrastes zum umliegenden Gewebe und des Aufbaus der teils thrombotisierten oder kalzifizierten Gefäßwände im Bereich eines Aneurysmas so komplex, dass sie aufgrund der Vielgestalt der Kontur in CT-Angiographie-Bildern die Verwendung eines statistischen Modells für Form und eingeschlossene Textur rechtfertigt. Für die Evaluation des Verfahrens wurden verschiedene statistische Modelle aus Schichten von neun CTA-Datensätzen trainiert und die Segmentierung anhand von Leave-One-Out-Tests überprüft.

Einfluss des Internets auf das Informations-, Einkaufs- und Verkehrsverhalten

NASA Astrophysics Data System (ADS)

Nerlich, Mark R.; Schiffner, Felix; Vogt, Walter

Mit Daten aus eigenen Erhebungen können das einkaufsbezogene Informations- und Einkaufsverhalten im Zusammenhang mit den verkehrlichen Aspekten (Distanzen, Verkehrsmittel, Wegekopplungen) dargestellt werden. Die Differenzierung in die drei Produktkategorien des täglichen, mittelfristigen und des langfristigen Bedarfs berücksichtigt in erster Linie die Wertigkeit eines Gutes, die seine Erwerbshäufigkeit unmittelbar bestimmt. Der Einsatz moderner IKT wie das Internet eröffnet dem Endverbraucher neue Möglichkeiten bei Information und Einkauf. Die verkehrliche Relevanz von Online-Shopping wird deutlich, wenn man berücksichtigt, dass im Mittel rund 17% aller Online-Einkäufe, die die Probanden durchgeführt haben, Einkäufe in Ladengeschäften ersetzen. Dies gilt in verstärktem Maße für Online-Informationen: etwa die Hälfte hätte alternativ im stationären Einzelhandel stattgefunden. Da der Erwerb von Gütern des täglichen Bedarfs häufig nahräumlich und in relevantem Anteil nicht-motorisiert erfolgen kann, sind in diesem Segment - im Gegensatz zum mittel- und langfristigen Bedarf - nur geringe Substitutionseffekte zu beobachten.

Effects of anisotropy in permeability on the two-phase flow and heat transfer in a porous cavity

NASA Astrophysics Data System (ADS)

Zhang, X. L.; Nguyen, T. Hung; Kahawita, R.

Zusammenfassung In der Arbeit wird über die Ergebnisse einer numerischen Studie, betreffend die stationäre Konvektionsströmung und den stationären Wärmeübergang in einer rechteckigen, mit einem porösen, phasenveränderlichen Medium (PCM) verfüllten Kavität, berichtet. Den zwei vertikalen Berandungen der Kavität sind zwei, den Schmelzpunkt des PCM einschließende Temperaturen aufgeprägt, während die beiden horizontalen Berandungen adiabat gehalten werden. Das poröse Medium ist durch einen anisotropen Permeabilitätstensor charakterisiert, dessen Hauptachsen bezüglich des Gravitationsvektors beliebig orientiert sein können. Das Problem ist durch das Seitenverhältnis A, die Rayleigh-Zahl Ra, das Anisotropienverhältnis R und den Orientierungswinkel Θ des Permeabilitätstensor bestimmt. Hauptaugenmerk gilt dem Einfluß der anisotropen Permeabilität auf das Strömungsverhalten und den Wärme-übergang beim Phasenwechselprozeß flüssig/fest. Die Lösungsmethode basiert auf dem Kontrollvolumenprinzip in Verbindung mit der Landau-Transformation über welche das irreguläre Strömungsgebiet in ein rechteckiges abgebildet wird. Ergebnisse bezüglich Strömungsfeld, Temperaturverteilung, Phasengrenzenort und Wärmeübergang werden fürA=2,5Ra=40 0<=Θ<=π 0,25<=R<=4 mitgeteilt. Es zeigte sich, daß der Gleichgewichtszustand des Phasenwechselsprozesses fest/flüssig sowohl durch das Anisotropieverhältnis R als auch durch den Orientierungswinkel Θ des Permeabilitätstensors wesentlich beeinflußt werden kann. Zum einen existiert bei festgehaltenen ParameternA, Ra undR eine optimale Orientierung Θmax, bei der die Stromstärke, das Flüssigkeitsvolumen und der Wärmestrom Maximalwerte erreichen, während für Θmin=Θmax+π/2 Minimalwerte resultieren. Ist das anisotrope Medium entlang der Optimalrichtung Θmax orientiert, so ergibt sich zum anderen, daß eine Vergrößerung der in diese Richtung fallenden Permeabilitätskomponente die Stromstärke und den Wärmestrom in gleichem Maße erhöht, während eine Vergrößerung der anderen Permeabilitätskomponente nur vernachlässigbaren Einfluß hat. In den untersuchten Parameterbereichen lag die Optimalrichtung zwischen dem Gravitationsvektor und der Hauptstromrichtung.

A Multilevel Shape Fit Analysis of Neutron Transmission Data

NASA Astrophysics Data System (ADS)

Naguib, K.; Sallam, O. H.; Adib, M.; Ashry, A.

A multilevel shape fit analysis of neutron transmission data is presented. A multilevel computer code SHAPE is used to analyse clean transmission data obtained from time-of-flight (TOF) measurements. The shape analysis deduces the parameters of the observed resonances in the energy region considered in the measurements. The shape code is based upon a least square fit of a multilevel Briet-Wigner formula and includes both instrumental resolution and Doppler broadenings. Operating the SHAPE code on a test example of a measured transmission data of 151Eu, 153Eu and natural Eu in the energy range 0.025-1 eV accquired a good result for the used technique of analysis.Translated AbstractAnalyse von Neutronentransmissionsdaten mittels einer VielniveauformanpassungNeutronentransmissionsdaten werden in einer Vielniveauformanpassung analysiert. Dazu werden bereinigte Daten aus Flugzeitmessungen mit dem Rechnerprogramm SHAPE bearbeitet. Man erhält die Parameter der beobachteten Resonanzen im gemessenen Energiebereich. Die Formanpassung benutzt eine Briet-Wignerformel und berücksichtigt Linienverbreiterungen infolge sowohl der Meßeinrichtung als auch des Dopplereffekts. Als praktisches Beispiel werden 151Eu, 153Eu und natürliches Eu im Energiebereich 0.025 bis 1 eV mit guter Übereinstimmung theoretischer und experimenteller Werte behandelt.

Biologie statt Philosophie? Evolutionäre Kulturerklärungen und ihre Grenzen

NASA Astrophysics Data System (ADS)

Illies, Christian

Vor über siebzig Jahren fand man in einer Höhle nahe Hohlenstein-Stadel, im heutigen Baden-Württemberg, eine Frau, die keiner bekannten Spezies und nicht einmal eindeutig den Hominiden zugeordnet werden konnte. Wegen ihres Aussehens wurde sie schon bald als "Löwenfrau“ bekannt (unterdessen wird sie als "Löwenmensch“ bezeichnet, da die in solchen Fragen Klarheit schaffenden Geschlechtsteile bei der Figur fehlen und in Zeiten von gender mainstreaming derartige Festlegungen gerne vermieden werden), denn sie hatte eine menschlich-aufrechte, unbehaarte Gestalt mit weiblichen Rundungen, aber zugleich eine Mähne, sowie Augen, Ohren und Schnauze eines Löwen. Eine sehr weitläufige Verwandte des Minotaurus, so schien es, und doch wesentlich älter als alle Bewohner des Olymps, denn vermutlich wurde die knapp 30 cm große Skulptur bereits in der Altsteinzeit vor etwa 32.000 Jahren aus Mammut-Elfenbein geschnitzt. Wir wissen nicht, ob sie kultischen Zwecken diente oder ein Kind mit ihr spielte, ob sie als Glücksbringer für die Jagd oder als Schamanin mit Löwenmaske verehrt und gefürchtet wurde. Aber die Löwenfrau legt nahe, dass der Mensch schon im Morgendämmern seiner Kultur über die eigene Nähe, aber auch Distanz zum Tier nachgedacht haben muss. Die Frage nach der menschlichen Selbstverortung begegnet uns in dieser Figur, und sie bestimmt viele Zeugnisse menschlichen Nachdenkens, welche uns die Altertumswissenschaften vorlegen. Mit dem Begriff "animal rationale“, wie er unter Bezug auf Aristoteles geprägt wurde, findet sie schließlich ihre klassische, für das Abendland lange Zeit maßgebliche Antwort: Der Mensch als Tier, dessen spezifisches Merkmal die Vernunftbegabtheit ist, die ihn zugleich von allen anderen Tieren abgrenzt und über sie stellt. Aber wo genau verläuft die Grenze? Und wie kann der Mensch beides zugleich sein? Die aristotelische Definition beantwortet diese Fragen nach der Doppelnatur nicht, sondern erhebt das offene Rätsel gleichsam zur Wesensbestimmung des Menschen.

Schreibende Messgeräte

NASA Astrophysics Data System (ADS)

Plaßmann, Wilfried

Die schreibenden Messgeräte werden hauptsächlich eingesetzt, um Vorgänge aufzuzeichnen und zu dokumentieren, die sich im Minuten- und Stunden-Bereich abspielen. Sie sind weitgehend durch Oszilloskope oder elektronische Geräte ähnlich einem Oszilloskop ersetzt worden, die entsprechend für Langzeitaufnahmen ausgelegt sind. Der Vorteil dieser Geräte gegenüber den schreibenden Messgeräten ist der, dass die Daten dauerhaft gespeichert sind, einschließlich der notwendigen Kenngrößen wie Zeitmaßstab, Amplitude, Datum, Aufzeichnungsgerät usw., und sich in dieser Form beliebig oft ausdrucken und vor allem direkt weiterverarbeiten lassen. Weiterhin entfallen die Probleme mit der Mechanik, dem Papier und den Schreibstiften. Deshalb folgt hier eine nur kurze Darstellung der Geräte.

b.i.t. Bremerhaven: Thin Clients entlasten Schulen

NASA Astrophysics Data System (ADS)

Das Schulamt Bremerhaven zentralisiert die Verwaltungs-IT und schafft dadurch Freiräume für pädagogische und organisatorische Herausforderungen. Pflege und Support der neuen Infrastruktur übernimmt der Dienstleister b.i.t. Bremerhaven, die Thin Clients kommen vom Bremer Hersteller IGEL Technology. Ganztagsschulen, das 12-jährige Abitur, PISA, der Wegfall der Orientierungsstufe - deutsche Schulen müssen derzeit zahlreiche organisatorische und pädagogische Herausforderungen bewältigen. Um die neuen Strukturen umsetzen zu können, werden zusätzliche Ressourcen benötigt. Das Schulamt Bremerhaven hat gemeinsam mit dem Dienstleister b.i.t. Bremerhaven (Betrieb für Informationstechnologie) eine intelligente Lösung gefunden, wie sich die benötigten finanziellen Freiräume schaffen lassen.

Encounters with neighbours : current developments of concepts based on recurrence plots and their applications

NASA Astrophysics Data System (ADS)

Marwan, Norbert

2003-09-01

In this work, different aspects and applications of the recurrence plot analysis are presented. First, a comprehensive overview of recurrence plots and their quantification possibilities is given. New measures of complexity are defined by using geometrical structures of recurrence plots. These measures are capable to find chaos-chaos transitions in processes. Furthermore, a bivariate extension to cross recurrence plots is studied. Cross recurrence plots exhibit characteristic structures which can be used for the study of differences between two processes or for the alignment and search for matching sequences of two data series. The selected applications of the introduced techniques to various kind of data demonstrate their ability. Analysis of recurrence plots can be adopted to the specific problem and thus opens a wide field of potential applications. Regarding the quantification of recurrence plots, chaos-chaos transitions can be found in heart rate variability data before the onset of life threatening cardiac arrhythmias. This may be of importance for the therapy of such cardiac arrhythmias. The quantification of recurrence plots allows to study transitions in brain during cognitive experiments on the base of single trials. Traditionally, for the finding of these transitions the averaging of a collection of single trials is needed. Using cross recurrence plots, the existence of an El Niño/Southern Oscillation-like oscillation is traced in northwestern Argentina 34,000 yrs. ago. In further applications to geological data, cross recurrence plots are used for time scale alignment of different borehole data and for dating a geological profile with a reference data set. Additional examples from molecular biology and speech recognition emphasize the suitability of cross recurrence plots. Diese Arbeit beschäftigt sich mit verschiedenen Aspekten und Anwendungen von Recurrence Plots. Nach einer Übersicht über Methoden, die auf Recurrence Plots basieren, werden neue Komplexitätsmaße eingeführt, die geometrische Strukturen in den Recurrence Plots beschreiben. Diese neuen Maße erlauben die Identifikation von Chaos-Chaos-Übergängen in dynamischen Prozessen. In einem weiteren Schritt werden Cross Recurrence Plots eingeführt, mit denen zwei verschiedene Prozesse untersucht werden. Diese bivariate Analyse ermöglicht die Bewertung von Unterschieden zwischen zwei Prozessen oder das Anpassen der Zeitskalen von zwei Zeitreihen. Diese Technik kann auch genutzt werden, um ähnliche Abschnitte in zwei verschiedenen Datenreihen zu finden. Im Anschluß werden diese neuen Entwicklungen auf Daten verschiedener Art angewendet. Methoden, die auf Recurrence Plots basieren, können an die speziellen Probleme angepaßt werden, so daß viele weitere Anwendungen möglich sind. Durch die Anwendung der neu eingeführten Komplexitätsmaße können Chaos-Chaos-Übergänge in Herzschlagdaten vor dem Auftreten einer lebensbedrohlichen Herzrhythmusstörung festgestellt werden, was für die Entwicklung neuer Therapien dieser Herzrhythmusstörungen von Bedeutung sein könnte. In einem weiteren Beispiel, in dem EEG-Daten aus einem kognitiv orientierten Experiment untersucht werden, ermöglichen diese Komplexitätsmaße das Erkennen von spezifischen Reaktionen im Gehirn bereits in Einzeltests. Normalerweise können diese Reaktionen erst durch die Auswertung von vielen Einzeltests erkannt werden. Mit der Hilfe von Cross Recurrence Plots wird die Existenz einer klimatischen Zirkulation, die der heutigen El Niño/ Southern Oscillation sehr ähnlich ist, im Nordwesten Argentiniens vor etwa 34000 Jahren nachgewiesen. Außerdem können mit Cross Recurrence Plots die Zeitskalen verschiedener Bohrlochdaten aufeinander abgeglichen werden. Diese Methode kann auch dazu genutzt werden, ein geologisches Profil mit Hilfe eines Referenzprofiles mit bekannter Zeitskala zu datieren. Weitere Beispiele aus den Gebieten der Molekularbiologie und der Spracherkennung unterstreichen das Potential dieser Methode.

Retrospektive Analyse von Zufallsbefunden, die bei Patienten mit kutanem malignen Malignom durch (18) F-Fluordeoxyglucose-PET/CT erhoben wurden.

PubMed

Conrad, Franziska; Winkens, Thomas; Kaatz, Martin; Goetze, Steven; Freesmeyer, Martin

2016-08-01

Bei der (18) F-Fluordeoxyglucose-Positronenemissionstomographie/Computertomographie (FDG-PET/CT) ergeben sich häufig Zufallsbefunde. In der vorliegenden Studie konzentrierten wir uns auf mittels FDG-PET/CT erhaltene Zufallsbefunde bei Patienten mit kutanem Melanom und überprüften deren Relevanz hinsichtlich weiterer diagnostischer Maßnahmen und Interventionen. Die Krankenakten von 181 konsekutiven Melanom-Patienten wurden retrospektiv ausgewertet, um das Management von Zufallsbefunden zu dokumentieren. Der Schwerpunkt lag dabei auf den histologischen Befunden. Bei 33 von 181 (18 %) Patienten lagen 39 relevante Zufallsbefunde vor, und zwar im Kolorektalbereich (n = 15 Patienten), in der Schilddrüse (n = 8), der Prostata (n = 2), dem Bewegungsapparat (n = 2), in Lymphknoten (n = 2), der Parotis (n = 1), den Mandeln (n = 1), den Nieren (n = 1) und der Gallenblase (n = 1). Bei 25 Patienten schlossen sich weitere diagnostische Verfahren an, wobei in 21 Fällen ein klinisches Korrelat nachgewiesen wurde. Bei 16 von 21 Patienten ergab sich eine Neoplasie, darunter fünf maligne Läsionen (vier Kolonkarzinome und ein Prostatakarzinom). Die Malignome wurden frühzeitig diagnostiziert und in der Mehrzahl der Fälle erfolgreich entfernt. Der Einsatz der FDG-PET/CT als Routine-Diagnostik wird in den Leitlinien empfohlen und ist indiziert bei malignem Melanom ab Stadium IIC. In dieser Studie wurden auf effektive Weise ansonsten nicht erkannte Krebserkrankungen, insbesondere Kolonkarzinome, detektiert. In den meisten Fällen war eine frühe Intervention möglich. Zufallsbefunde durch FDG-PET/CT sollten, unter Berücksichtigung des Zustands und der Wünsche des Patienten, mit den geeigneten diagnostischen Maßnahmen abgeklärt werden. © 2016 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

Niederschlag

NASA Astrophysics Data System (ADS)

Kunz, Michael; Mohr, Susanna; Werner, Peter C.

Niederschlag kann in flüssiger Form als Niesel oder Regen oder in gefrorener, fester Form als Graupel, Hagel oder Schnee fallen. Durch die globale Erwärmung intensiviert sich der Wasserkreislauf, was zu einer Veränderung der Niederschlagsmuster führt. Außerdem ist zu erwarten, dass sich im Zuge des Klimawandels auch die Häufigkeit bestimmter Wetterlagen ändern wird, die das Niederschlagsgeschehen grundsätzlich bestimmen. Bereits heute ist in Deutschland eine Änderung der Niederschlagsaktivität zu beobachten. Das Kapitel beschäftigt sich neben den sommerlichen und winterlichen Starkniederschlagsereignissen auch mit Hagelereignissen und dem Schneefall. Neben einer Zusammenfassung der bereits beobachteten Änderungen dieser Niederschlagsformen in der Vergangenheit wird auch der Frage nachgegangen, inwieweit man für diese Ereignisse belastbare Aussagen für die Zukunft treffen kann.

[Not Available].

PubMed

Hainschitz, I; Rieger, K; Siegl, H

2002-06-01

In Austria an index of 3 μg/kg of Ochratoxin A for coffee, 0,3 μg/kg for fruit juices and 0,2 μg/kg for beer is discussed. The laboratory of the food inspection authority of the state of Vorarlberg investigated the contribution of selected foodstuffs to the daily OTA intake and compared it with the recommendation of the scientific food committee of the EC. The focal point of this study was on beverages (coffee, coffee substitutes, beer and fruit juices) and their ingredients.ZUSAMMENFASSUNG: Die Untersuchungsergebnisse von Bier, Fruchtsaft und Kaffee [Diagramm 1] zeigen, dass die Mehrzahl der Proben nur sehr schwach bis gar nicht belastet waren. Die OTA-Belastung lag bei der Mehrzahl der Proben unter der Nachweisgrenze von 0,3 μg/kg bzw. 0,01μg/1. Einzelne Proben waren aber erheblich belastet, sodass bei starkem Konsum (Fruchtsaft im Sommer) eine überschreitung der vom SCF vorgeschlagenen Höchstmenge nicht auszuschließen ist. Die Ergebnisse der Kaffeemitteluntersuchung [Diagramm 2] belegen eine höhere OTA-Belastung bei mehr als der Hälfte der Proben. Wenn die vom SCF vorgeschlagene Höchstaufnahme von 5 ng pro Tag und kg Körpergewicht zu Grunde gelegt wird, resultiert für eine 60 kg schwere Person ein Wert von 0,3 μg/Tag. Das bedeutet bei einem mit 100 μg/kg OTA kontaminierten Kaffeeersatz und dem Konsum nur einer Tasse (5 - 7 g Pulver), dass alleine aus dieser Quelle diese Höchstaufnahme deutlich überschritten wird. Der Eintrag über die restliche Nahrung wie Cerealien, die für etwa die Hälfte der OTA-Aufnahme verantwortlich sind, bleibt hier unberücksichtigt. Die Untersuchungen belegen, dass die Einhaltung der in österreich vorgeschlagenen Richtwerte bei Bier, Fruchtsäften und Kaffee keine Schwierigkeiten bereitet. Für Kaffeemittel und andere Trockenfrüchte als Weintrauben [3] wurde allerdings noch kein Richtwert vorgeschlagen. Die Ergebnisse belegen aber, dass gerade für Kaffemittel und verschiedene Trockenfrüchte vor dem Hintergrund fehlender Höchstwerte ein Richtwert in der Größenordnung von 3 μg/kg bzw. 10 μg/kg hilfreich wäre, bis die Festlegung der gemeinschaftsrechtlicher Höchstgehalte erfolgt. Mit Hinblick auf die in der Einleitung beschriebene toxische Wirkung von OTA ist es im Sinne eines vorbeugenden Verbraucherschutzes wichtig, diese hochbelasteten Chargen zu erkennen und aus dem Verkehr zu nehmen. Ursache für die OTA-Kontamination ist vor allem eine mangelhafte Produktionshygiene in den Erzeugerländern. Dort liegt auch das größte Potential für eine Verringerung der OTA-Belastung. Die überprüfung der Lebensmittel auf Ochratoxin A durch die amtliche Lebensmittelkontrolle ist ein notwendiger Beitrag zum Schutz der öffentlichen Gesundheit und zur weiteren Reduktion der Aufnahme.

Die Digitalisierung der Energiewirtschaft: Potenziale und Herausforderungen der IKT-Branche für Utility 4.0

NASA Astrophysics Data System (ADS)

Aichele, Christian; Schönberger, Marius

Energieunternehmen haben auf dem Weg zur digitalen Transformation noch viele Herausforderungen zu bewältigen. Ein besonderer Schwerpunkt liegt derzeit auf der Modernisierung der IT-Systeme. Ausgangspunkt hierzu ist, dass sich bei den Endkonsumenten Mobile Applikationen, Smartphones, Tablet-PCs oder Smart TVs einer immensen Beliebtheit erfreuen. Durch diese Technologien wird die physische und virtuelle Welt in immer weiter zunehmendem Maße miteinander verknüpft. Mobile Applikation können einen wahren Hype hervorrufen und Verhaltensweisen auch nachhaltig verändern (ein Beispiel hierfür ist Pokémon Go, eine App die ein virtuelles Spiel mit der realen Umgebung kombiniert und die erstmalig auch eingefleischte Zocker aus der Anonymität ihrer häuslichen Umgebung hervorlocken konnte und für analoge Bewegung im Freien sorgte).

Auf dem Weg zur digitalen Fakultät - moderne IT Infrastruktur am Beispiel des Physik-Departments der TU München

NASA Astrophysics Data System (ADS)

Homolka, Josef

Der Geschäftsbetrieb einer Universität ist durch zunehmende Digitalisierung und Nutzung elektronischer Medien gekennzeichnet. Die Einführung immer leistungsfähigerer zentraler IT-Systeme führt zu einer komplexen Vielfalt heterogener Benutzer- und Administrationsschnittstellen. Zur Schaffung einer umfassenden benutzerfreundlichen und nahtlosen IT-Infrastruktur ist die Beteiligung aller organisatorischen Einheiten und Ebenen erforderlich. Am Physik-Departement der Technischen Universität München wurden unter Integration eigener Ressourcen mit zentralen Ressourcen, die im Rahmen des IntegraTUM Projektes entwickelt und bereitgestellt wurden, existierende Dienste weiterentwickelt und neue Angebote aufgebaut. Das System, bestehend aus den Komponenten Netzwerk, Arbeitsplatzrechner, Serverinfrastruktur, E-Mail-Service, WWWDienst, Datenhaltung und Software wurde für die Nutzerkreise Studenten und Mitarbeiter im Hinblick auf Anwenderfreundlichkeit und nahtlosen Zugriff optimiert.

Virtuelle Kraftwerke für Smart Markets

NASA Astrophysics Data System (ADS)

Dürr, Thomas; Heyne, Jean-Christoph

In den zurückliegenden Jahren haben insbesondere zwei Trends die Stromversorgung bestimmt: der starke Anstieg der dezentralen und der Ausbau der regenerativen Stromerzeugung, die vor allem in den Verteilnetzen stattfinden. Angesichts dieser Entwicklung gewinnen virtuelle Kraftwerke (VK) immer mehr an Bedeutung. In der frühen Phase waren VK insbesondere eine Möglichkeit, kleine dezentrale Erzeuger zu einer größeren Einheit zu bündeln und sie so marktfähig zu machen. Heute werden sie - überwacht und gesteuert über ein Dezentrales Energie-Management-System (DEMS) - gemeinsam mit Demand Response betrieben, also dem Reagieren eines Energieabnehmers auf Marktpreise. Das Demand Side Management soll zur Flexibilisierung der Industrie beitragen. Da der Ausbau der Übertragungsnetze nur schleppend vorankommt, kann die Nutzung von lastseitiger Flexibilität einen wichtigen Beitrag zur Versorgungssicherheit leisten. Im zweiten Teil des Beitrags geht es um die Entwicklung der Märkte. Großes Interesse besteht immer noch an der Regelenergie, zumal der Bedarf bis 2050 deutlich steigen wird. Die Spotmärkte Intraday und Day-Ahead wachsen kontinuierlich, deshalb werden sie für VK immer wichtiger. Am Ende gibt der Beitrag einen Ausblick auf die künftige Entwicklung, in der Regelenergie- und Spotmärkte noch eine Rolle spielen, aber andere Geschäftsmodelle wichtiger werden. Darüber hinaus geht es um langfristige Entwicklungen, die z. B. zusätzliche Serviceleistungen durch VK betreffen.

Digitalisierung als Inkubator für die Energieversorgung von morgen

NASA Astrophysics Data System (ADS)

Arnold, Christian; Postina, Matthias

Neue Treiber der Digitalisierung bestimmen die Geschicke der etablierten Unternehmen im Energiebereich, dabei haben diese in vielen Fällen noch nicht einmal adäquat auf die altbekannten Treiber der Energiewende reagiert. Eine ganze Branche ist im Umbruch, alte Erlösmodelle brechen ein und Einigkeit scheint bei den Verantwortlichen nur in der Frage zu herrschen, wie in Zukunft noch Geld verdient werden kann. Dieser Beitrag erklärt die prägenden Treiber der Veränderung, analysiert die Ausgangslage und nennt Herausforderungen der Branche. Darüber hinaus legt er den Fokus auf die Betrachtung der neuen digitalen Wertschöpfung. Dazu wird ein Modell eingeführt, welches von der klassischen Wertschöpfungskette über datenbasierte Geschäftsmodelle im Energiesystem bis hin zum Internet of Smart Services reicht. Mit dem Modell geben die Autoren gleichsam Einblick in das geplante Energiewendeprojekt enera.

Supply Chain Management (SCM) mit Kanban

NASA Astrophysics Data System (ADS)

Beer, Anja; Dickmann, Eva; Dickmann, Philipp; Gerth, Wolf-Michael; Graßy, Mario; Herron, Colin; Schmidt, Peter; Seidl, Florian; Wittmann, Claus-Eduard

Nach Schätzungen von Mercer Management Consulting und dem Fraunhofer Institut wird der Wertschöpfungsanteil in der Automobilindustrie von durchschnittlich 35 % im Jahr 2002 auf 23 % im Jahr 2015 sinken [Merc 04]. Der Trend, die Produktionstiefe oder allgemeiner, die Wertschöpfungstiefe, zu reduzieren, hat zur Folge, dass die Kaufteile den größeren Teil der Wertschöpfung einnehmen. Die Optimierungspotentiale und der Einfluss auf die Kosten wandern immer mehr zu den Lieferanten, vor allem bei größeren Unternehmen oder Konzernen. Lieferanten-Philosophien, die auf oberflächlichen Verbindungen zu Lieferanten aufbauen, um immer optimal und schnell den günstigsten Teilepreis zu erhalten, haben sich in vielen Sparten oder Produktbereichen, z. B. im Maschinenbau, im besten Fall als kurzfristig erfolgreich erwiesen. Kooperative und nachhaltige Strategien sind der erfolgversprechendere Weg, zumindest mittelbis langfristig. In der Realität wird sehr wenig in Supply Chain-Konzepte investiert und die Umsetzungen sind daher vielmals oberflächlich.

Zu einer inhaltsorientierten Theorie des Lernens und Lehrens der biologischen Evolution

NASA Astrophysics Data System (ADS)

Wallin, Anita

Der Zweck dieser Studie (zwecks Überblick siehe dazu Abb. 9.1) war zu untersuchen, wie die Schüler der Sekundarstufe II ein Verständnis von der Theorie der biologischen Evolution entwickeln. Vom Ausgangspunkt "Vorurteile der Schüler“ ausgehend wurden Unterrichtssequenzen entwickelt und drei verschiedene Lernexperimente in einem zyklischen Prozess durchgeführt. Das Wissen der Schüler wurde vor, während und nach den Unterrichtssequenzen mit Hilfe von schriftlichen Tests, Interviews und Diskussionsrunden in kleinen Gruppen abgefragt. Etwa 80 % der Schüler hatten vor dem Unterricht alternative Vorstellungen von Evolution, und in dem Nachfolgetest erreichten circa 75 % ein wissenschaftliches Niveau. Die Argumentation der Schüler in den verschiedenen Tests wurde sorgfältig unter Rücksichtnahme auf Vorurteile, der konzeptionellen Struktur der Theorie der Evolution und den Zielen des Unterrichts analysiert. Daraus konnten Einsichten in solche Anforderungen an Lehren und Lernen gewonnen werden, die Herausforderungen an Schüler und Lehrer darstellen, wenn sie anfangen, evolutionäre Biologie zu lernen oder zu lehren. Ein wichtiges Ergebnis war, dass das Verständnis existierender Variation in einer Population der Schlüssel zum Verständnis von natürlicher Selektion ist. Die Ergebnisse sind in einer inhaltsorientierten Theorie zusammengefasst, welche aus drei verschiedenen Aspekten besteht: 1) den inhaltsspezifischen Aspekten, die einzigartig für jedes wissenschaftliche Feld sind; 2) den Aspekten, die die Natur der Wissenschaft betreffen; und 3) den allgemeinen Aspekten. Diese Theorie kann in neuen Experimenten getestet und weiter entwickelt werden.

Neue biosensorische Prinzipien für die Hämoglobin-A1c Bestimmung

NASA Astrophysics Data System (ADS)

Stöllner, Daniela

2002-06-01

Hämoglobin-A1c (HbA1c) ist ein Hämoglobin (Hb)-Subtypus, der durch nicht-enzymatische Glykierung des N-terminalen Valinrestes der Hämoglobin-beta-Kette entsteht. Das gemessene Verhältnis von HbA1c zum Gesamt-Hämoglobin (5-20 % bei Diabetikern) repräsentiert den Mittelwert der Blutglucosekonzentration über einen zweimonatigen Zeitraum und stellt zur Beurteilung der diabetischen Stoffwechsellage eine Ergänzung zur Akutkontrolle der Glukosekonzentration dar. Ziel der vorliegenden Arbeit war es, einen amperometrischen Biosensor für die Bestimmung des medizinisch relevanten Parameters HbA1c zu entwickeln. Durch Selektion geeigneter Bioerkennungselemente und deren Immobilisierung unter Erhalt der Bindungsfunktion für die Zielmoleküle Hämoglobin bzw. HbA1c wurden spezifische, hochaffine und regenerationsstabile Sensoroberflächen geschaffen. Für die Entwicklung des HbA1c-Biosensors wurden zwei Konzepte - Enzymsensor und Immunosensor - miteinander verglichen. Die enzymatische Umsetzung von HbA1c erfolgte mit der Fructosylamin Oxidase (FAO) aus Pichia pastoris N 1-1 unter Freisetzung von H2O2, welches sowohl optisch über eine Indikatorreaktion als auch elektrochemisch nach Einschluss der FAO in PVA-SbQ und Fixierung des Immobilisats vor einer H2O2-Elektrode nachgewiesen wurde. Die Kalibration des Enzymsensors mit der HbA1c-Modellsubstanz Fructosyl-Valin ergab Nachweisgrenzen, die ausserhalb des physiologisch relevanten HbA1c-Konzentrationsbereich lagen. Aus der Umsetzung von glykierten Peptiden mit einer nicht HbA1c analogen Aminosäurensequenz, z.B. Fructosyl-Valin-Glycin wurde zudem eine geringe HbA1c-Spezifität abgeleitet. Für den Immunosensor wurden zwei heterogene Immunoassay-Formate unter Verwendung von hochaffinen und spezifischen Antikörpern in Kombination mit Glucose Oxidase (GOD) als Markerenzym zum Nachweis von HbA1c untersucht. Beim indirekt-kompetitiven Immunoassay wurde anstelle des kompletten HbA1c-Moleküls das glykierte Pentapeptid Fructosyl-Valin-Histidin-Leucin-Threonin-Prolin (glkPP) als Kompetitor und Affinitätsligand immobilisiert und so eine regenerierfähige Oberfläche geschaffen. Beim Sandwich-Immunoassay wurde im ersten Schritt Gesamt-Hämoglobin an die mit Haptoglobin (Hp) modifizierte Festphase angereichert und im zweiten Schritt der gebundene HbA1c-Anteil nachgewiesen. Für die Konstruktion des HbA1c-Immunosensors wurden Affinitätsmatrizen durch Modifizierung von Cellulose-Dialysemembranen mit glkPP bzw. Hp hergestellt. Grundlegend studiert wurde die Aktivierung der Cellulose-Membranen mit 1,1'-Carbonyldiimidazol (CDI) und 1-Cyano-4-dimethylaminopyridintetrafluoroborat (CDAP) als Aktivierungsagenzien. Eine gerichtete Immobilisierung der Liganden wurde realisiert, indem glkPP über dessen C-Terminus (einzige Carboxylatgruppe) und Hp über dessen periodat-oxidiertem Kohlenhydratrest an die amino- oder hydrazidfunktionalisierte Membranen kovalent gekoppelt wurden. Mit dem Einsatz der glkPP- und Hp-modifizierten Membranen in der elektrochemischen Messzelle war erstmalig der biosensorische Nachweis von HbA1c möglich. Als Transduktor diente eine Pt-Elektrode, an der das von der GOD generierte H2O2 umgesetzt und ein mit der HbA1c-Konzentration korrelierendes Stromsignal erzeugt wurde. Die Immunosensoren zeigten Ansprechzeiten von 3 s. Mit dem Immunosensor auf Basis des indirekt-kompetitiven Testprinzips wurde eine Kalibrationskurve für HbA1c im Bereich von 0,25-30 µg/ml (3,9-465 nM, CV 3-9 %) mit Assayzeiten von 60 min und mit dem Immunosensor im Sandwich-Format eine Kalibrationskurve im Bereich von 0,5-5 µg/ml (7,8-78 nM; 5-50 % HbA1c vom Gesamt-Hb, CV 6-10 %, 3 h) aufgenommen. Hemoglobin-A1c (HbA1c) is a hemoglobin subtype formed by non-enzymatic reaction of glucose with the N-terminus of the beta-polypeptide chains. As it reflects the glycemic status of diabetics over the preceding 8-12 weeks, the determination of HbA1c has become an established procedure in the management of diabetes mellitus. It is measured as the percentage of total hemoglobin. Up to 5 % HbA1c are considered as normal whereas in diabetic subjects it could be elevated from 5-20 %. In addition to amperometric biosensors for glucose self monitoring which have been successfully applied in diabetes management, biosensors for HbA1c would be an useful supplement for a comprehensive diabetes control. Objective of this work was to develop and compare amperometric biosensors for determination of HbA1c based on enzymatic and immunochemical methods. For the enzyme based HbA1c assay a novel fructosamine oxidase (FAO) derived from marine yeast Pichia pastoris, strain N1-1 was utilized. It recognizes and oxidatively degrades fructosyl-valine (FV) which corresponds to the glycated N-terminus of the beta-chain of HbA1c and therefore is regarded as a model compound for HbA1c. Hydrogen peroxide which is liberated by the FAO during FV conversion was indicated optically in a horseradish peroxidase (POD) coupled reaction and electrochemically. For the biosensor the FAO was embedded in polyvinyl alcohol-stylbazole (PVA-SbQ) and fixed it in front of a Pt-electrode. So far, the measuring range of FV did not cover the clinically relevant range of HbA1c. Low specificity was assumed since enzyme activity also was obtained with glycated peptides, e.g. fructosyl-valine-glycine, not corresponding to the glycated N-terminus of the hemoglobin-beta-chain. For the immunosensor two immunoassays formats - heterogeneous sandwich and heterogeneous competitive - were tested. The assays were designed as follows: The competitive immunoassay was based on the immobilized synthetic glycated pentapeptide fructosyl-valine-histidine-leucine-threonine-proline (glkPP) utilized as HbA1c analogue. The peptide has an amino acid sequence corresponding to the N-terminus of the hemoglobin beta-chains and is capable for competition together with the HbA1c of the sample for the amount of a glucose oxidase (GOD)-labelled anti-HbA1c antibody. In the sandwich-type assay haptoglobin (Hp), a natural hemoglobin binding molecule with antibody characteristic properties, was used as bioreceptor for enrichment of total hemoglobin onto the surface. In a subsequent step the HbA1c fraction was quantified by a GOD-labelled HbA1c specific antibody. Cellulose dialysis membrane was used as the solid support for immobilization of Hp and glkPP near the sensor surface. For activation of the membrane two reagents, 1,1‧-carbonyldiimidazole (CDI) and 1-cyano-4-dimethylamino pyridinium tetrafluoroborate (CDAP), were compared with respect to the degree of activation and coupling efficiency. Site-directed immobilization of Hp and glkPP was achieved by coupling Hp via its carbohydrate residue and glkPP via its C-terminus to the activated membrane using a bis-amine or bis-hydrazide spacer. The affinity membranes were placed in front of a modified Clark-type hydrogen peroxide electrode in an electrochemical measuring cell and HbA1c analysis was carried out within the stirred cell. Detection of the bound GOD-label was achieved by measurement of the electrocatalytic oxidation of hydrogen peroxide at +600 mV vs. Ag/AgCl. The indication was done in only 3 s. For the competitive principle a typical inhibition curve with a linear range between 0,25-30 µg/ml (3,9-465 nM, CV 3-9 %, 60 min per sample) HbA1c was obtained. Due to the high functional stability of the peptide multiple regeneration of the affinity surface was possible without loss of binding capacity. With the sandwich assay configuration the clinically relevant range could easily be covered (calibration curve: 5-50 % HbA1c corresponding to 7,8-78 nM, CV 6-10 %, 3 h per sample).

Entwicklung von umwelt- und naturschutzgerechten Verfahren der landwirtschaftlichen Landnutzung für das Biosphärenreservat Schorfheide-Chorin

NASA Astrophysics Data System (ADS)

Meyer-Aurich, Andreas

1999-11-01

Mit der vorliegenden Arbeit werden exemplarisch Chancen und Grenzen der Integration von Umwelt- und Naturschutz in Verfahren der ackerbaulichen Landnutzung aufgezeigt. Die Umsetzung von Zielen des Umwelt- und Naturschutzes in Verfahren der Landnutzung ist mit verschiedenen Schwierigkeiten verbunden. Diese liegen zum einen in der Konkretisierung der Ziele, um diese umsetzen zu können, zum anderen in vielfach unzulänglichem Wissen über den Zusammenhang zwischen unterschiedlichen Formen der Landnutzung und insbesondere den biotischen Naturschutzzielen. Zunächst wird die Problematik der Zielfestlegung und Konkretisierung erörtert. Das Umweltqualitätszielkonzept von Fürst et al. (1992) stellt einen Versuch dar, Ziele des Umwelt- und Naturschutzes zu konkretisieren. Dieses Konzept haben Heidt et al. (1997) auf einen Landschaftsausschnitt von ca. 6000 ha im Biosphärenreservat Schorfheide-Chorin im Nordosten Brandenburgs angewendet. Eine Auswahl der von Heidt et al. (1997) formulierten Umweltqualitätsziele bildet die Basis dieser Arbeit. Für die ausgewählten Umweltqualitätsziele wurden wesentliche Einflussfaktoren der Landnutzung identifiziert und ein Bewertungssystem entwickelt, mit dem die Auswirkungen von landwirtschaftlichen Anbauverfahren auf diese Umweltqualitätsziele abgebildet werden können. Die praktizierte Landnutzung von 20 Betrieben im Biosphärenreservat Schorfheide-Chorin wurde von 1994 bis 1997 hinsichtlich ihrer Auswirkungen auf die Umweltqualitätsziele analysiert. Die Analyse ergab ein sehr differenziertes Bild, das zum Teil Unterschiede in der Auswirkung auf die Umweltqualitätsziele für den Anbau einzelner Kulturen oder für bestimmte Betriebstypen zeigte. Es zeigte sich aber auch, dass es bei der Gestaltung des Anbaus einzelner Kulturarten große Unterschiede gab, die für Umweltqualitätsziele Bedeutung haben. Neben der Analyse der Landnutzung im Biosphärenreservat Schorfheide-Chorin wurde ein System entwickelt, mit dem die modellhafte Abbildung von Verfahren der Landnutzung möglich ist. Die Modellverfahren wurden in eine umfangreiche Datenbank eingebunden. Sie wurden mit Hilfe eines Fuzzy- Regelsystems hinsichtlich ihrer Auswirkungen auf die Umweltqualitätsziele bewertet. Die systematisch bewerteten Verfahren wurden in ein Betriebsmodell integriert, womit eine weitergehende Analyse der Zielbeziehungen und die Berechnung von Szenarien mit unterschiedlichen Rahmenbedingungen ermöglicht wurde. Die Analyse der Beziehung verschiedener Ziele zueinander (Zieldivergenz, Zielkonvergenz) zeigte, dass sich mit der Verfolgung vieler Umweltqualitätsziele auch positive Effekte für andere Umweltqualitätsziele ergaben. Teilweise konnte allerdings auch eine Zieldivergenz festgestellt werden, die auf mögliche Zielkonflikte hinweist. Bei der Analyse der Szenarienergebnisse zeigte sich, dass die vorgeschlagenen Veränderungen von Rahmenbedingungen vielfach eine Verschlechterung für verschiedene Umweltqualitätsziele mit sich bringen. Eine Ursache dafür liegt darin, dass bei der Definition der Szenarien die Bedeutung der Stilllegungen unterschätzt wurde. The objective of this research was to show the opportunities and limitations associated with integrating of environmental goals into agricultural land use management. For this purpose, the impact of agricultural land uses on six environmental quality goals was analysed for an approximately 16.000 ha study region within the biosphere reserve Schorfheide-Chorin in north-eastern Brandenburg (Germany). The environmental quality goals considered were protection of ground water, preservation of groundwater recharge, protection of the soil against wind and water erosion and preservation of animal species typical of the agricultural landscape, in particular partridge, amphibians and cranes. For each environmental quality goal, an evaluation framework is presented which enables an assessment of the impact of agricultural land uses on the environmental quality goals. The evaluation framework was applied to assess the impact of land uses of twenty farms in the study area from 1994 to 1997. It was demonstrated that the impact of agricultural land uses on the environmental quality of the region is very complex, and - although some crops did significantly impact certain aspects, one factor did not overwhelmingly contribute to the overall environmental quality. The evaluation framework was integrated further into a system of modelled cropping practices for optimisation calculations. For this purpose, a model framework was established based on a MS Access database. In the database, cropping practices for 17 crops are stored. Inputs and yields are adapted to the site-specific yield potential. In addition to the cropping practices, the model framework is comprised of an evaluation module and optimisation module. Hence, the impact of the cropping practices can be assessed for each site. This model framework provides the basis for optimisation calculations to forecast various land uses under different conditions. A step-wise integration of the environmental quality goals into the optimisation algorithm of a model farm allows for showing trade-offs between economic and ecological goals. The results of the trade-offs show that an improvement of ecological goal achievement is possible with little impact on the gross margin, as long as the improvement is less than 30% of the starting situation. If improvements greater than 30% are desired, very high losses of gross margin must be taken into consideration. Another result of the calculations shows that high achievements of environmental quality goals often correlate with the percentage of set-aside land within the total area.

Hardware-Abbildung eines videobasierten Verfahrens zur echtzeitfähigen Auswertung von Winkelhistogrammen auf eine modulare Coprozessor-Architektur

NASA Astrophysics Data System (ADS)

Flatt, H.; Tarnowsky, A.; Blume, H.; Pirsch, P.

2010-10-01

Dieser Beitrag behandelt die Abbildung eines videobasierten Verfahrens zur echtzeitfähigen Auswertung von Winkelhistogrammen auf eine modulare Coprozessor-Architektur. Die Architektur besteht aus mehreren dedizierten Recheneinheiten zur parallelen Verarbeitung rechenintensiver Bildverarbeitungsverfahren und ist mit einem RISC-Prozessor verbunden. Eine konfigurierbare Architekturerweiterung um eine Recheneinheit zur Auswertung von Winkelhistogrammen von Objekten ermöglicht in Verbindung mit dem RISC eine echtzeitfähige Klassifikation. Je nach Konfiguration sind für die Architekturerweiterung auf einem Xilinx Virtex-5-FPGA zwischen 3300 und 12 000 Lookup-Tables erforderlich. Bei einer Taktfrequenz von 100 MHz können unabhängig von der Bildauflösung pro Einzelbild in einem 25-Hz-Videodatenstrom bis zu 100 Objekte der Größe 256×256 Pixel analysiert werden. This paper presents the mapping of a video-based approach for real-time evaluation of angular histograms on a modular coprocessor architecture. The architecture comprises several dedicated processing elements for parallel processing of computation-intensive image processing tasks and is coupled with a RISC processor. A configurable architecture extension, especially a processing element for evaluating angular histograms of objects in conjunction with a RISC processor, provides a real-time classification. Depending on the configuration of the architecture extension, 3 300 to 12 000 look-up tables are required for a Xilinx Virtex-5 FPGA implementation. Running at a clock frequency of 100 MHz and independently of the image resolution per frame, 100 objects of size 256×256 pixels are analyzed in a 25 Hz video stream by the architecture.

Deutsches "Nationales Krebshilfe-Monitoring" 2015-2019 - Studienprotokoll und erste Ergebnisse.

PubMed

Schneider, Sven; Görig, Tatiana; Schilling, Laura; Breitbart, Eckhard W; Greinert, Rüdiger; Diehl, Katharina

2017-09-01

Das Projekt "Nationales Krebshilfe-Monitoring zur Solariennutzung" (National Cancer Aid Monitoring of Tanning Bed Use, NCAM) ist eine deutsche Großstudie mit dem Ziel, die wichtigsten Risikofaktoren für Hautkrebs zu beobachten: natürliches Sonnenlicht und künstliche UV-Strahlung. NCAM ist eine bundesweite Querschnittstudie mit zunächst vier Runden der Datenerfassung (sogenannten Wellen) zwischen 2015 und 2018. Jedes Jahr wird eine bundesweit repräsentative Stichprobe aus 3.000 Personen im Alter von 14 bis 45 Jahren befragt. Die Querschnittsbefragung wird durch eine Kohorte von n = 450 aktuellen Solariennutzern ergänzt. Die erste Welle im Jahr 2015 ergab eine Gesamtprävalenz der Solariennutzung von 29,5 %. Elf Prozent aller Teilnehmer hatten in den vergangenen zwölf Monaten ein Solarium genutzt. Zu den Determinanten der aktuellen Solariennutzung gehörten jüngeres Alter, weibliches Geschlecht und Vollzeit-/Teilzeitbeschäftigung. Die hauptsächlichen Beweggründe, die für die Nutzung eines Solariums genannt wurden, waren Entspannung und Attraktivitätssteigerung. NCAM ist weltweit die erste Studie zur Überwachung der Risikofaktoren für Hautkrebs in jährlichen Intervallen anhand einer großen, landesweit repräsentativen Stichprobe. Erste Ergebnisse deuten darauf hin, dass Millionen Deutsche trotz Warnungen der WHO Solarien nutzen, und dass viele dieser Nutzer Jugendliche sind - trotz gesetzlicher Beschränkungen, die das Ziel haben, die Nutzung von Solarien durch Minderjährige zu verhindern. © 2017 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

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

NASA Astrophysics Data System (ADS)

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.

Magnetic jets from accretion disks : field structure and X-ray emission

NASA Astrophysics Data System (ADS)

Memola, Elisabetta

2002-06-01

Jets are highly collimated flows of matter. They are present in a large variety of astrophysical sources: young stars, stellar mass black holes (microquasars), galaxies with an active nucleus (AGN) and presumably also intense flashes of gamma-rays. In particular, the jets of microquasars, powered by accretion disks, are probably small-scale versions of the outflows from AGN. Beside observations of astrophysical jet sources, also theoretical considerations have shown that magnetic fields play an important role in jet formation, acceleration and collimation. Collimated jets seem to be systematically associated with the presence of an accretion disk around a star or a collapsed object. If the central object is a black hole, the surrounding accretion disk is the only possible location for a magnetic field generation. We are interested in the formation process of highly relativistic jets as observed from microquasars and AGN. We theoretically investigate the jet collimation region, whose physical dimensions are extremely tiny even compared to radio telescopes spatial resolution. Thus, for most of the jet sources, global theoretical models are, at the moment, the only possibility to gain information about the physical processes in the innermost jet region. For the first time, we determine the global two-dimensional field structure of stationary, axisymmetric, relativistic, strongly magnetized (force-free) jets collimating into an asymptotically cylindrical jet (taken as boundary condition) and anchored into a differentially rotating accretion disk. This approach allows for a direct connection between the accretion disk and the asymptotic collimated jet. Therefore, assuming that the foot points of the field lines are rotating with Keplerian speed, we are able to achieve a direct scaling of the jet magnetosphere in terms of the size of the central object. We find a close compatibility between the results of our model and radio observations of the M87 galaxy innermost jet. We also calculate the X-ray emission in the energy range 0.2--10.1,keV from a microquasar relativistic jet close to its source of 5 solar masses. In order to do it, we apply the jet flow parameters (densities, velocities, temperatures of each volume element along the collimating jet) derived in the literature from the relativistic magnetohydrodynamic equations. We obtain theoretical thermal X-ray spectra of the innermost jet as composition of the spectral contributions of the single volume elements along the jet. Since relativistic effects as Doppler shift and Doppler boosting due to the motion of jets toward us might be important, we investigate how the spectra are affected by them considering different inclinations of the line of sight to the jet axis. Emission lines of highly ionized iron are clearly visible in our spectra, probably also observed in the Galactic microquasars GRS 1915+105 and XTE J1748-288. The Doppler shift of the emission lines is always evident. Due to the chosen geometry of the magnetohydrodynamic jet, the inner X-ray emitting part is not yet collimated. Ergo, depending on the viewing angle, the Doppler boosting does not play a major role in the total spectra. This is the first time that X-ray spectra have been calculated from the numerical solution of a magnetohydrodynamic jet. Astrophysikalische Jets sind stark kollimierte Materieströmungen hoher Geschwindigkeit. Sie stehen im Zusammenhang mit einer Fülle verschiedener astrophysikalischer Objekte wie jungen Sternen, stellaren schwarzen Löchern ('Mikro-Quasare'), Galaxien mit aktivem Kern (AGN) und wahrscheinlich auch mit dem beobachteten intensiven Aufblitzen von Gamma-Strahlung (Gamma Ray Bursts). Insbesondere hat sich gezeigt, dass die Jets der Mikro-Quasare wahrscheinlich als kleinskalige Version der Jets der AGN anzusehen sind. Neben den Beobachtungen haben vor allem auch theoretische Überlegungen gezeigt, dass Magnetfelder bei der Jetentstehung, -beschleunigung und -kollimation eine wichtige Rolle spielen. Weiterhin scheinen Jets systematisch verknüpft zu sein mit dem Vorhandensein einer Akkretionsscheibe um das zentrale Objekt. Insbesondere wenn ein schwarzes Loch den Zentralkörper darstellt, ist die umgebende Akkretionsscheibe der einzig mögliche Ort um Magnetfeld erzeugen zu können. Wir sind speziell interessiert am Entstehungsprozess hoch relativistischer Jets wie sie bei Mikro-Quasaren und AGN beobachtet werden. Insbesondere untersuchen wir die Region, in der der Jet kollimiert, eine Region, deren räumliche Ausdehnung extrem klein ist selbst im Vergleich zur Auflösung der Radioteleskope. Dies ist ein Grund, wieso zum heutigen Zeitpunkt für die meisten Quellen die theoretische Modellierung die einzige Möglichkeit darstellt, um Information über die physikalischen Prozesse in der innersten Region der Jetentstehung zu erhalten. Uns ist es zum ersten Mal gelungen, die globale zwei-dimensionale Magnetfeldstruktur stationärer, axialsymmetrischer, relativistischer und stark magnetisierter (kräfte-freier) Jets zu berechnen, die zum einen asymptotisch in einen zylindrischen Jet kollimieren, zum anderen aber in einer differential rotierenden Akkretionsscheibe verankert sind. Damit erlaubt dieser Ansatz eine physikalische Verkn¨upfung zwischen Akkretionsscheibe und dem asymptotischen Jet. Nimmt man also an, dass die Fupunkte der Magnetfeldlinien mit Keplergeschwindigkeit rotieren, so kann man eine direkte Skalierung der Jetmagnetosphere mit der Gröe des Zentralobjektes erhalten. Unsere Resultate zeigen eine gute Übereinstimmung zwischen unserem Modell und Beobachtungen des Jets von M87. Für das Beispiel eines relativistischen Mikroquasarjets haben wir die Röntgenemission im Bereich von 0.2-10.1 keV berechnet. Dafür haben wir in der Literatur aus den relativistischen magnetohydrodynamischen Gleichungen berechnete Jetgröen (Dichte-, Geschwindigkeits-, und Temperaturprofil) verwendet und das Spektrum für jeden Punkt entlang der Jetströmung abgeleitet. Das theoretische thermische Röntgenspektrum des innersten, heien Teils des Jets erhalten wir zusammengesetzt aus den spektralen Anteilen der einzelnen Volumenelemente entlang des Jets. Um relativistische Effekte wie Dopplerverschiebung und -verstärkung (boosting) aufgrund der Jetbewegung zu untersuchen, haben wir für verschiedene Inklinationswinkel des Jets zur Sichtlinie berechnet, wie die erhaltenen Spektren davon beeinflusst werden. Unsere Spektren zeigen deutlich die hochionisierten Eisen-Emissionslinien, die in den galaktischen Mikroquasaren GRS 1915+105 und XTE J1748-288 andeutungsweise beobachtet wurden. Eine Dopplerverschiebung dieser Linien ist in unseren Spektren deutlichzu sehen. Da die innerste, Röntgenstrahlung emittierende Region des magnetohydrodynamischen Jets allerdings noch unkollimiert ist, spielt Dopplerboosting in unseren Spektren, abhängig vom Sichtwinkel, keine groe Rolle. Mit unseren Resultaten konnte zum ersten Mal ein Röntgenspektrum gewonnen werden, das auf der numerischen Lösung eines magnetohydrodynamischen Jets beruht.

FORS am Very Large Telescope der Europäischen Südsternwarte

NASA Astrophysics Data System (ADS)

1998-09-01

Erstes wissenschaftliches Beobachtungsinstrument liefert eindrucksvolle Bilder Entsprechend dem straffen Zeitplan wird das ESO Very Large Teleskop Projekt (VLT-Projekt) auf dem Cerro Paranal in Nord-Chile verwirklicht: die volle Betriebsbereitschaft des ersten der vier 8,2m-Einzelteleskope wird Anfang des nächsten Jahres erreicht sein. Am 15. September 1998 wurde ein weiterer wichtiger Meilenstein erfolgreich, rechtzeitig und innerhalb des Kostenplans erreicht. Nur wenige Tage nach seiner Montage am ersten 8,2m-Einzelteleskop des VLT (UT1) konnte FORS1 ( FO cal R educer and S pectrograph) als erstes einer Gruppe leistungsfähiger und komplexer wissenschaftlicher Instrumente seine Beobachtungstätigkeit beginnen. Von Anfang an konnte es eine Reihe exzellenter astronomischer Bilder aufnehmen. Dieses bedeutende Ereignis eröffnet eine Fülle neuer Möglichkeiten für die europäische Astronomie. FORS - ein Höhepunkt an Komplexität FORS1 und das zukünftige Zwillingsinstrument (FORS2) sind das Ergebnis einer der eingehendsten und fortschrittlichsten technologischen Studien, die je für ein Instrument der bodengebundenen Astronomie durchgeführt wurden. Dieses einzigartige Instrument ist nun im Cassegrain-Fokus installiert und verschwindet beinahe, trotz seiner Dimensionen von 3 x 1.5m (Gewicht 2.3t), unterhalb des riesigen 53 m 2 großen Zerodurspiegels. Um die große Spiegelfläche und die hervorragende Bildqualität von UT1 optimal auszunützen, wurde FORS speziell so konstruiert, daß es die lichtschwächsten und entferntesten Objekte im Weltall untersuchen kann. Bald wird dieses komplexe VLT-Instrument den europäischen Astronomen erlauben, die derzeitigen Beobachtungshorizonte entscheidend zu erweitern. Die beiden FORS-Instrumente sind Vielzweck-Beobachtungsinstrumente, die in mehreren unterschiedlichen Beobachtungsarten eingesetzt werden können. Beispielsweise können Bilder mit zwei verschiedenen Abbildungsmaßstäben (Vergrößerungen) sowie Spektren mit unterschiedlicher spektraler Auflösung von einzelnen oder mehreren Objekten aufgenommen werden. Dabei erlaubt der schnelle Wechsel zwischen den unterschiedlichen Beobachtungsarten z.B. zunächst die Aufnahme und direkt anschließend die Spektroskopie weit entfernter Galaxien. Damit kann dann u.a. die stellare Zusammensetzung und die Entfernung bestimmt werden. Als eines der leistungsfähigsten astronomischen Instrumente seiner Art wird FORS1 ein wahres Arbeitspferd für die Untersuchung des fernen Universums darstellen. Der Bau von FORS Das FORS-Projekt wird unter ESO-Kontrakt von einem Konsortium dreier deutscher astronomischer Institute durchgeführt, der Landessternwarte Heidelberg und den Universitäts-Sternwarten von Göttingen and München. Bis zur Beendigung des Projekts werden die beteiligten Institute Arbeit im Umfang von ca. 180 Mann-Jahren eingebracht haben. Bei der Landessternwarte Heidelberg lag die Leitung des Projekts. Hier wurde außerdem das gesamte optische System konstruiert, die Beschaffung der Komponenten der abbildenden Optik und der Zusatzoptiken für Spektroskopie und Polarimetrie durchgeführt und die spezielle Computersoftware geschrieben, mit der die von FORS gelieferten Daten verarbeitet und ausgewertet werden. Darüber hinaus wurde in der Werkstatt der Sternwarte ein Teleskopsimulator gebaut, mit dem alle wesentlichen Funktionen von FORS in Europa getestet werden konnten, bevor das Instrument zum Paranal (Chile) transportiert wurde. An der Universitäts-Sternwarte Göttingen wurden Konstruktion, Herstellung und Zusammenbau der gesamten Mechanik von FORS durchgeführt. Der größte Teil der Präzisionsteile, insbesondere der Multispalteinheit, wurde in der feinmechanischen Werkstatt der Sternwarte hergestellt. Die Beschaffung der großen Instrumentengehäuse und Flansche, die Computeranalysen für mechanische und thermische Stabilität des empfindlichen Spektrographen und die Herstellung der speziellen Werkzeuge für Handhabung, Wartung und Justierung lag ebenso in der Verantwortung dieser Sternwarte wie die Tests der zahlreichen opto- und elektromechanischen Funktionen. Die Universitäts-Sternwarte München war verantwortlich für das Projektmanagement, Integration und Test des gesamten Instruments im Labor, für Planung und Einbau aller Elektronik und Elektromechanik, sowie für Entwicklung und Test der gesamten Software, die FORS in allen Teilen vollständig per Computer steuert (z.B. Filter- und Grismräder, Verschlüsse, Spalteinheit für die Vielspaltspektroskopie, Masken, alle optischen Komponenten, Elektromotoren, Encoder usw.). Zusätzlich wurde Computersoftware geschrieben, mit der die komplexen astronomischen Beobachtungen mit FORS vorbereitet werden und das Verhalten des Instruments durch eine ständige Kontrolle der gesammelten wissenschaftlichen Daten überwacht wird. Als Gegenleistung für den Bau von FORS erhalten die Astronomen der drei beteiligten Institute des FORS-Konsortiums eine gewisse Anzahl von Nächten an "garantierter Beobachtungszeit" am VLT. In dieser Beobachtungszeit werden verschiedene Forschungsprojekte durchgeführt, deren Themen unter anderem von kleinen Körpern im äußeren Sonnensystem über Untersuchungen von Sternen im Endstadium und den von ihnen abgestoßenen Gaswolken bis zur Erforschung ferner Galaxien und Quasare reichen, die Aufschluß über die frühen Zeiten unseres Universums geben. Erste Tests von FORS1 am VLT-UT1: ein großartiger Erfolg Nach sorgfältiger Vorbereitung hat das FORS-Konsortium nun mit der Inbetriebnahme ("Commissioning") des Instruments begonnen. Dazu gehören ein eingehender Nachweis der spezifizierten Leistungsfähigkeit am Teleskop, die Überprüfung der korrekten Funktionsweise unter Softwaresteuerung vom Kontrollraum auf Paranal, und am Ende dieses Prozesses eine Demonstration, daß das Instrument seinen angestrebten wissenschaftlichen Zweck erfüllt. Während der Durchführung dieser Tests gelangen dem Commissioning-Team auf Paranal eine Reihe von Aufnahmen verschiedener astronomischer Objekte, von denen einige hier wiedergegeben sind. Sie wurden alle mit FORS in der Standardauflösung gewonnen (Bildfeldgröße 6.8 x 6.8 Bogenminuten, Pixelgröße 0.20 Bogensekunden) und zeigen einige der eindrucksvollen Möglichkeiten, die das neue Instrument bietet. Spiralgalaxie NGC 1288 ESO PR Photo 37a/98 ESO PR Photo 37a/98 [Preview - JPEG: 800 x 908 pix - 224k] [High-Res - JPEG: 3000 x 3406 pix - 1.5Mb] Farbaufnahme der Spiralgalaxie NGC 1288, aufgenommen in der ersten Beobachtungsnacht von FORS ("Nacht des ersten Lichts"). Das erste Photo zeigt eine Dreifarbenaufnahme der schönen Spiralgalaxie NGC 1288 im südlichen Sternbild Fornax. PR Photo 37a/98 umfaßt das gesamte Feld, das mit der 2048 x 2048 Pixel großen CCD-Kamera abgebildet wurde. Es wurde aus drei CCD-Aufnahmen zusammengesetzt, die bei gutem Seeing in verschiedenen Farben in der "Nacht des ersten Lichts" (15. September 1998) aufgenommen wurden. Diese Galaxie mit einem Durchmesser von rund 200000 Lichtjahren ist etwa 300 Millionen Lichtjahre entfernt, ihre Fluchtgeschwindigkeit beträgt 4500 km/sec. Technische Informationen : Photo 37a/98 ist ein Komposit von drei Aufnahmen in den drei Filtern B (420nm, 6 Minuten belichtet), V (530nm, 3 Minuten) und I (800nm, 3 Minuten) während einer Periode mit 0.7 Bogensekunden Seeing. Das gezeigte Feld ist 6.8 x 6.8 Bogenminuten groß. Norden ist links, Osten unten. Entfernter Galaxienhaufen ESO PR Photo 37b/98 ESO PR Photo 37b/98 [Preview - JPEG: 657 x 800 pix - 248k] [High-Res - JPEG: 2465 x 3000 pix - 1.9Mb] Ein ungewöhnlicher Galaxienhaufen in der Umgebung des Quasars PB5763 . ESO PR Photo 37c/98 ESO PR Photo 37c/98 [Preview - JPEG: 670 x 800 pix - 272k] [High-Res - JPEG: 2512 x 3000 pix - 1.9Mb] Vergrößerung von PR Photo 37b/98; sie zeigt mehr Einzelheiten des ungewöhnlichen Galaxienhaufens. Die nächsten Photos wurden von einer 5-minütigen Aufnahme im Nahen Infrarot reproduziert, die ebenfalls in der "Nacht des ersten Lichts" von FORS1 (15. September 1998) gewonnen wurde. PR Photo 37b/98 zeigt einen Himmelsausschnitt in der Nähe des Quasars PB5763, in dem auch ein ungewöhnlicher, sehr weit entfernter Haufen von Galaxien zu sehen ist. Er besteht aus einer großen Zahl lichtschwacher Galaxien, die bisher noch nicht eingehend untersucht wurden. Dieser Haufen ist ein gutes Beispiel für die Art von Objekten, auf die viel Beobachtungszeit mit FORS verwendet werden wird, sobald der reguläre Beobachtungsbetrieb begonnen hat. Eine Vergrößerung des gleichen Feldes ist in PR Photo 37c/98 wiedergegeben. Sie zeigt die einzelnen Mitglieder dieses Galaxienhaufens im Detail. Man beachte besonders die interessante spindelförmige Galaxie, die anscheinend einen äquatorialen Ring aufweist. Neben einer schönen Spiralgalaxie sind auch noch viele weitere lichtschwache Galaxien zu erkennen. Sie sind entweder Zwerggalaxien und Mitglieder des Haufens oder befinden sich sehr viel weiter entfernt im Hintergrund des Haufens. Technische Informationen : PR Photos 37b/98 (als Negativ reproduziert) und 37c/98 (Positiv) stammen von einer Aufnahme, die bei 0.8 Bogensekunden Seeing durch ein I-Filter (nahes Infrarot, 800nm) gewonnen wurde. Die Belichtungszeit betrug 5 Minuten, und es wurde eine Flatfield-Korrektur durchgeführt. Das gezeigte Feld ist 6.8 x 6.8 Bogenminuten bzw. 2.5 x 2.3 Bogenminuten groß. Norden ist links oben, Osten links unten. Spiralgalaxie NGC 1232 ESO PR Photo 37d/98 ESO PR Photo 37d/98 [Preview - JPEG: 800 x 912 pix - 760k] [High-Res - JPEG: 3000 x 3420 pix - 5.7Mb] Ein Farbbild der Spiralgalaxie NGC 1232, aufgenommen am 21. September 1998. ESO PR Photo 37e/98 ESO PR Photo 37e/98 [Preview - JPEG: 800 x 961 pix - 480k] [High-Res - JPEG: 3000 x 3602 pix - 3.5Mb] Vergrößerung des Zentrums von PR Photo 37d/98. Dieses spektakuläre Bild der großen Spiralgalaxie NGC 1232 (Photo 37d/98) wurde am 21. September 1998 unter guten Beobachtungsbedingungen erhalten. Es wurde aus drei Einzelaufnahmen im ultravioletten, blauen und roten Licht zusammengesetzt. Die Farben der verschiedenen Regionen sind deutlich sichtbar: Das Zentralgebiet enthält ältere, rötlich leuchtende Sterne (Photo 37e/98), während die Spiralarme von jungen, bläulichen Sternen und roten Sternentstehungsgebieten bevölkert sind. Man beachte die gestörte Begleitgalaxie am linken Rand (Photo 37d/98), die wie der griechische Buchstabe "Theta" aussieht. NGC 1232 liegt 20 Grad südlich des Himmelsäquators im Sternbild Eridanus. Obwohl die Entfernung dieser Galaxie ungefähr 100 Millionen Lichtjahre beträgt, kann man auf Grund der exzellenten Bildqualität einen unglaublichen Reichtum an Details erkennen. Bei dieser Entfernung entspricht die Kantenlänge des Bildfeldes etwa 200000 Lichtjahren oder etwa der doppelten Größe unserer Milchstraße. Technische Informationen : Photos 37d/98 und 37e/98 sind ein Komposit von drei Aufnahmen in den drei Filtern U (360nm, 10 Minuten belichtet), B (420nm, 6 Minuten) und R (600nm, 2 Minuten 30 Sekunden) während einer Periode mit 0.7 Bogensekunden Seeing. Das gezeigte Feld ist 6.8 x 6.8 Bogenminuten bzw. 1.6 x 1.8 Bogenminuten groß. Norden ist oben, Osten links. Note: [1] Diese Pressemitteilung wird gemeinsam (auf Englisch und Deutsch) von der Europäischen Südsternwarte, der Landessternwarte Heidelberg und den Universitäts-Sternwarten Göttingen und München herausgegeben. An English Version of this Press Release is also available. Zugang zu ESO Presseinformationen ESO Presseinformationen werden im World Wide Web zur Verfügung gestellt (URL: http://www.eso.org/outreach/press-rel/). ESO Pressephotos dürfen veröffentlicht werden, wenn die Europäische Südsternwarte als Urheber genannt wird.

Ein statistisches Modell zum Einfluß der thermischen Bewegung auf NMR-Festkörperspektren

NASA Astrophysics Data System (ADS)

Ploss, W.; Freude, D.; Pfeifer, H.; Schmiedel, H.

Es wird ein statistisches Modell zum Einfluß der thermischen Bewegung auf die NMR-Linienform vorgestellt, das die Verschmälerung von Festkörper-Spektren bei wachsender Temperatur beschreibt. Das Modell geht von der Annahme aus, daß nach einer Ortsveränderung eines Kerns infolge thermischer Bewegung jede beliebige Kernresonanzfrequenz mit der durch das Festkörperspektrum vorgegebenen Wahrscheinlichkeit angenommen werden kann. Am Beispiel der Festkörper-Gaußlinie wird der Unterschied zu dem bekannten Modell von ANDERSON und WEISS verdeutlicht.Translated AbstractA Statistical Model for the Influence of Thermal Motion on N. M. R. Spectra in SolidsA theory is proposed which allows to describe the narrowing of n. m. r.-line width in the presence of thermal motions of the spins. The model is based on the assumption, that the local resonance frequency of a given spin immediately after the jump is distributed according to the n. m. r.-line shape of the rigid lattice. The difference to the well-known ANDERSON-WEISS-model of spectral narrowing is demonstrated for a gaussian line shape.

Assessing the quality of digital elevation models obtained from mini unmanned aerial vehicles for overland flow modelling in urban areas

NASA Astrophysics Data System (ADS)

Leitão, João P.; Moy de Vitry, Matthew; Scheidegger, Andreas; Rieckermann, Jörg

2016-04-01

Precise and detailed digital elevation models (DEMs) are essential to accurately predict overland flow in urban areas. Unfortunately, traditional sources of DEM, such as airplane light detection and ranging (lidar) DEMs and point and contour maps, remain a bottleneck for detailed and reliable overland flow models, because the resulting DEMs are too coarse to provide DEMs of sufficient detail to inform urban overland flows. Interestingly, technological developments of unmanned aerial vehicles (UAVs) suggest that they have matured enough to be a competitive alternative to satellites or airplanes. However, this has not been tested so far. In this study we therefore evaluated whether DEMs generated from UAV imagery are suitable for urban drainage overland flow modelling. Specifically, 14 UAV flights were conducted to assess the influence of four different flight parameters on the quality of generated DEMs: (i) flight altitude, (ii) image overlapping, (iii) camera pitch, and (iv) weather conditions. In addition, we compared the best-quality UAV DEM to a conventional lidar-based DEM. To evaluate both the quality of the UAV DEMs and the comparison to lidar-based DEMs, we performed regression analysis on several qualitative and quantitative metrics, such as elevation accuracy, quality of object representation (e.g. buildings, walls and trees) in the DEM, which were specifically tailored to assess overland flow modelling performance, using the flight parameters as explanatory variables. Our results suggested that, first, as expected, flight altitude influenced the DEM quality most, where lower flights produce better DEMs; in a similar fashion, overcast weather conditions are preferable, but weather conditions and other factors influence DEM quality much less. Second, we found that for urban overland flow modelling, the UAV DEMs performed competitively in comparison to a traditional lidar-based DEM. An important advantage of using UAVs to generate DEMs in urban areas is their flexibility that enables more frequent, local, and affordable elevation data updates, allowing, for example, to capture different tree foliage conditions.

The Importance of Precise Digital Elevation Models (DEM) in Modelling Floods

NASA Astrophysics Data System (ADS)

Demir, Gokben; Akyurek, Zuhal

2016-04-01

Digital elevation Models (DEM) are important inputs for topography for the accurate modelling of floodplain hydrodynamics. Floodplains have a key role as natural retarding pools which attenuate flood waves and suppress flood peaks. GPS, LIDAR and bathymetric surveys are well known surveying methods to acquire topographic data. It is not only time consuming and expensive to obtain topographic data through surveying but also sometimes impossible for remote areas. In this study it is aimed to present the importance of accurate modelling of topography for flood modelling. The flood modelling for Samsun-Terme in Blacksea region of Turkey is done. One of the DEM is obtained from the point observations retrieved from 1/5000 scaled orthophotos and 1/1000 scaled point elevation data from field surveys at x-sections. The river banks are corrected by using the orthophotos and elevation values. This DEM is named as scaled DEM. The other DEM is obtained from bathymetric surveys. 296 538 number of points and the left/right bank slopes were used to construct the DEM having 1 m spatial resolution and this DEM is named as base DEM. Two DEMs were compared by using 27 x-sections. The maximum difference at thalweg of the river bed is 2m and the minimum difference is 20 cm between two DEMs. The channel conveyance capacity in base DEM is larger than the one in scaled DEM and floodplain is modelled in detail in base DEM. MIKE21 with flexible grid is used in 2- dimensional shallow water flow modelling. The model by using two DEMs were calibrated for a flood event (July 9, 2012). The roughness is considered as the calibration parameter. From comparison of input hydrograph at the upstream of the river and output hydrograph at the downstream of the river, the attenuation is obtained as 91% and 84% for the base DEM and scaled DEM, respectively. The time lag in hydrographs does not show any difference for two DEMs and it is obtained as 3 hours. Maximum flood extents differ for the two DEMs, larger flooded area is simulated from scaled DEM. The main difference is observed for the braided and meandering parts of the river. For the meandering part of the river, additional 1.82 106 m3 water (5% of the total volume) is calculated as the flooded volume simulated by using the scaled DEM. For the braided stream part 0.187 106 m3 more water is simulated as the flooded volume by the scaled DEM. The flood extent around the braided part of the river is 27.6 ha larger in the simulated flood map obtained from scaled DEM compared to the one obtained from base DEM. Around the meandering part of the river scaled DEM gave 59.8 ha more flooded area. The importance of correct topography of the braided and meandering part of the river in flood modelling and the uncertainty it brings to modelling are discussed in detail.

Generation of a precise DEM by interactive synthesis of multi-temporal elevation datasets: a case study of Schirmacher Oasis, East Antarctica

NASA Astrophysics Data System (ADS)

Jawak, Shridhar D.; Luis, Alvarinho J.

2016-05-01

Digital elevation model (DEM) is indispensable for analysis such as topographic feature extraction, ice sheet melting, slope stability analysis, landscape analysis and so on. Such analysis requires a highly accurate DEM. Available DEMs of Antarctic region compiled by using radar altimetry and the Antarctic digital database indicate elevation variations of up to hundreds of meters, which necessitates the generation of local improved DEM. An improved DEM of the Schirmacher Oasis, East Antarctica has been generated by synergistically fusing satellite-derived laser altimetry data from Geoscience Laser Altimetry System (GLAS), Radarsat Antarctic Mapping Project (RAMP) elevation data and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) global elevation data (GDEM). This is a characteristic attempt to generate a DEM of any part of Antarctica by fusing multiple elevation datasets, which is essential to model the ice elevation change and address the ice mass balance. We analyzed a suite of interpolation techniques for constructing a DEM from GLAS, RAMP and ASTER DEM-based point elevation datasets, in order to determine the level of confidence with which the interpolation techniques can generate a better interpolated continuous surface, and eventually improve the elevation accuracy of DEM from synergistically fused RAMP, GLAS and ASTER point elevation datasets. The DEM presented in this work has a vertical accuracy (≈ 23 m) better than RAMP DEM (≈ 57 m) and ASTER DEM (≈ 64 m) individually. The RAMP DEM and ASTER DEM elevations were corrected using differential GPS elevations as ground reference data, and the accuracy obtained after fusing multitemporal datasets is found to be improved than that of existing DEMs constructed by using RAMP or ASTER alone. This is our second attempt of fusing multitemporal, multisensory and multisource elevation data to generate a DEM of Antarctica, in order to address the ice elevation change and address the ice mass balance. Our approach focuses on the strengths of each elevation data source to produce an accurate elevation model.

Hydraulic correction method (HCM) to enhance the efficiency of SRTM DEM in flood modeling

NASA Astrophysics Data System (ADS)

Chen, Huili; Liang, Qiuhua; Liu, Yong; Xie, Shuguang

2018-04-01

Digital Elevation Model (DEM) is one of the most important controlling factors determining the simulation accuracy of hydraulic models. However, the currently available global topographic data is confronted with limitations for application in 2-D hydraulic modeling, mainly due to the existence of vegetation bias, random errors and insufficient spatial resolution. A hydraulic correction method (HCM) for the SRTM DEM is proposed in this study to improve modeling accuracy. Firstly, we employ the global vegetation corrected DEM (i.e. Bare-Earth DEM), developed from the SRTM DEM to include both vegetation height and SRTM vegetation signal. Then, a newly released DEM, removing both vegetation bias and random errors (i.e. Multi-Error Removed DEM), is employed to overcome the limitation of height errors. Last, an approach to correct the Multi-Error Removed DEM is presented to account for the insufficiency of spatial resolution, ensuring flow connectivity of the river networks. The approach involves: (a) extracting river networks from the Multi-Error Removed DEM using an automated algorithm in ArcGIS; (b) correcting the location and layout of extracted streams with the aid of Google Earth platform and Remote Sensing imagery; and (c) removing the positive biases of the raised segment in the river networks based on bed slope to generate the hydraulically corrected DEM. The proposed HCM utilizes easily available data and tools to improve the flow connectivity of river networks without manual adjustment. To demonstrate the advantages of HCM, an extreme flood event in Huifa River Basin (China) is simulated on the original DEM, Bare-Earth DEM, Multi-Error removed DEM, and hydraulically corrected DEM using an integrated hydrologic-hydraulic model. A comparative analysis is subsequently performed to assess the simulation accuracy and performance of four different DEMs and favorable results have been obtained on the corrected DEM.

Validation of digital elevation models (DEMs) and comparison of geomorphic metrics on the southern Central Andean Plateau

NASA Astrophysics Data System (ADS)

Purinton, Benjamin; Bookhagen, Bodo

2017-04-01

In this study, we validate and compare elevation accuracy and geomorphic metrics of satellite-derived digital elevation models (DEMs) on the southern Central Andean Plateau. The plateau has an average elevation of 3.7 km and is characterized by diverse topography and relief, lack of vegetation, and clear skies that create ideal conditions for remote sensing. At 30 m resolution, SRTM-C, ASTER GDEM2, stacked ASTER L1A stereopair DEM, ALOS World 3D, and TanDEM-X have been analyzed. The higher-resolution datasets include 12 m TanDEM-X, 10 m single-CoSSC TerraSAR-X/TanDEM-X DEMs, and 5 m ALOS World 3D. These DEMs are state of the art for optical (ASTER and ALOS) and radar (SRTM-C and TanDEM-X) spaceborne sensors. We assessed vertical accuracy by comparing standard deviations of the DEM elevation versus 307 509 differential GPS measurements across 4000 m of elevation. For the 30 m DEMs, the ASTER datasets had the highest vertical standard deviation at > 6.5 m, whereas the SRTM-C, ALOS World 3D, and TanDEM-X were all < 3.5 m. Higher-resolution DEMs generally had lower uncertainty, with both the 12 m TanDEM-X and 5 m ALOS World 3D having < 2 m vertical standard deviation. Analysis of vertical uncertainty with respect to terrain elevation, slope, and aspect revealed the low uncertainty across these attributes for SRTM-C (30 m), TanDEM-X (12-30 m), and ALOS World 3D (5-30 m). Single-CoSSC TerraSAR-X/TanDEM-X 10 m DEMs and the 30 m ASTER GDEM2 displayed slight aspect biases, which were removed in their stacked counterparts (TanDEM-X and ASTER Stack). Based on low vertical standard deviations and visual inspection alongside optical satellite data, we selected the 30 m SRTM-C, 12-30 m TanDEM-X, 10 m single-CoSSC TerraSAR-X/TanDEM-X, and 5 m ALOS World 3D for geomorphic metric comparison in a 66 km2 catchment with a distinct river knickpoint. Consistent m/n values were found using chi plot channel profile analysis, regardless of DEM type and spatial resolution. Slope, curvature, and drainage area were calculated and plotting schemes were used to assess basin-wide differences in the hillslope-to-valley transition related to the knickpoint. While slope and hillslope length measurements vary little between datasets, curvature displays higher magnitude measurements with fining resolution. This is especially true for the optical 5 m ALOS World 3D DEM, which demonstrated high-frequency noise in 2-8 pixel steps through a Fourier frequency analysis. The improvements in accurate space-radar DEMs (e.g., TanDEM-X) for geomorphometry are promising, but airborne or terrestrial data are still necessary for meter-scale analysis.

Urban DEM generation, analysis and enhancements using TanDEM-X

NASA Astrophysics Data System (ADS)

Rossi, Cristian; Gernhardt, Stefan

2013-11-01

This paper analyzes the potential of the TanDEM-X mission for the generation of urban Digital Elevation Models (DEMs). The high resolution of the sensors and the absence of temporal decorrelation are exploited. The interferometric chain and the problems encountered for correct mapping of urban areas are analyzed first. The operational Integrated TanDEM-X Processor (ITP) algorithms are taken as reference. The ITP main product is called the raw DEM. Whereas the ITP coregistration stage is demonstrated to be robust enough, large improvements in the raw DEM such as fewer percentages of phase unwrapping errors, can be obtained by using adaptive fringe filters instead of the conventional ones in the interferogram generation stage. The shape of the raw DEM in the layover area is also shown and determined to be regular for buildings with vertical walls. Generally, in the presence of layover, the raw DEM exhibits a height ramp, resulting in a height underestimation for the affected structure. Examples provided confirm the theoretical background. The focus is centered on high resolution DEMs produced using spotlight acquisitions. In particular, a raw DEM over Berlin (Germany) with a 2.5 m raster is generated and validated. For this purpose, ITP is modified in its interferogram generation stage by adopting the Intensity Driven Adaptive Neighbourhood (IDAN) algorithm. The height Root Mean Square Error (RMSE) between the raw DEM and a reference is about 8 m for the two classes defining the urban DEM: structures and non-structures. The result can be further improved for the structure class using a DEM generated with Persistent Scatterer Interferometry. A DEM fusion is thus proposed and a drop of about 20% in the RMSE is reported.

Elevation validation and geomorphic metric comparison with focus on ASTER GDEM2, SRTM- C, ALOS World 3D, and TanDEM-X

NASA Astrophysics Data System (ADS)

Purinton, Benjamin; Bookhagen, Bodo

2017-04-01

Geomorphologists use digital elevation models (DEMs) to quantify changes in topography - often without rigorous accuracy assessments. In this study we validate and compare elevation accuracy and derived geomorphic metrics from the current generation of satellite-derived DEMs on the southern Central Andean Plateau. The average elevation of 3.7 km, diverse topography and relief, lack of vegetation, and clear skies create ideal conditions for remote sensing in this study area. DEMs at resolutions of 5-30 m are sourced from open-access, research agreement, and commercial outlets, with a focus on the 30 m SRTM-C, 30 m ASTER GDEM2, 12 m TanDEM-X, and 5 m ALOS World 3D data. In addition to these edited products, manually generated DEMs included 10 m single-CoSSC TerraSAR-X / TanDEM-X DEMs and a 30 m stacked ASTER L1A stereopair DEM. We assessed vertical accuracy by comparing standard deviations (SD) of the DEM elevation versus 307,509 differential GPS (dGPS) measurements with < 0.5 m vertical accuracy, acquired across 4,000 m of elevation. Vertical SD was 3.33 m, 9.48 m, 6.93 m, 1.97 m, 2.02-3.83 m, and 1.64 m for the 30 m SRTM-C, 30 m ASTER GDEM2, 30 m stacked ASTER, 12 m TanDEM-X, 10 m single-CoSSC TerraSAR-X / TanDEM-X DEMs, and 5 m ALOS World 3D, respectively. Analysis of vertical uncertainty with respect to terrain elevation, slope, and aspect revealed the high performance across these attributes of the 30 m SRTM-C, 12 m TanDEM-X, and 5 m ALOS World 3D DEMs. The 10 m single-CoSSC TerraSAR-X / TanDEM-X DEMs and the 30 m ASTER GDEM2 displayed slight aspect biases, which were removed in their stacked counterparts (TanDEM-X and the stacked ASTER DEMs). We selected the high quality 30 m SRTM-C, 12 m TanDEM-X, and 5 m ALOS World 3D for geomorphic metric comparison in a 66 sqkm catchment with a clear river knickpoint. For trunk channel profiles analyzed with chi plots, consistent m/n values of 0.49-0.57 were found regardless of DEM resolution or SD. Hillslopes were analyzed upstream and downstream of the knickpoint by calculating slope and curvature distributions and plotting slope, curvature, and drainage area to assess the hillslope-to-valley transition. While slope and hillslope length measurements vary little between datasets, curvature displays higher magnitude measurements with fining resolution. To assess DEM noise and periodicity in the landscape we employed a Fourier analysis to identify DEM frequencies and their spectral power. The optical 5 m ALOS World 3D DEM shows high-frequency noise in 2-8 pixel steps, with no corresponding landscape features in this highly diffusive, vegetation-free environment. Finally, we explore the geomorphometric potential of the higher-quality 12 m TanDEM-X DEM through a hillslope length and surface roughness assessment across steep environmental, climatic and topographic gradients in the Quebrada del Toro catchment, west of Salta, Argentina.

A comparative appraisal of hydrological behavior of SRTM DEM at catchment level

NASA Astrophysics Data System (ADS)

Sharma, Arabinda; Tiwari, K. N.

2014-11-01

The Shuttle Radar Topography Mission (SRTM) data has emerged as a global elevation data in the past one decade because of its free availability, homogeneity and consistent accuracy compared to other global elevation dataset. The present study explores the consistency in hydrological behavior of the SRTM digital elevation model (DEM) with reference to easily available regional 20 m contour interpolated DEM (TOPO DEM). Analysis ranging from simple vertical accuracy assessment to hydrological simulation of the studied Maithon catchment, using empirical USLE model and semidistributed, physical SWAT model, were carried out. Moreover, terrain analysis involving hydrological indices was performed for comparative assessment of the SRTM DEM with respect to TOPO DEM. Results reveal that the vertical accuracy of SRTM DEM (±27.58 m) in the region is less than the specified standard (±16 m). Statistical analysis of hydrological indices such as topographic wetness index (TWI), stream power index (SPI), slope length factor (SLF) and geometry number (GN) shows a significant differences in hydrological properties of the two studied DEMs. Estimation of soil erosion potentials of the catchment and conservation priorities of microwatersheds of the catchment using SRTM DEM and TOPO DEM produce considerably different results. Prediction of soil erosion potential using SRTM DEM is far higher than that obtained using TOPO DEM. Similarly, conservation priorities determined using the two DEMs are found to be agreed for only 34% of microwatersheds of the catchment. ArcSWAT simulation reveals that runoff predictions are less sensitive to selection of the two DEMs as compared to sediment yield prediction. The results obtained in the present study are vital to hydrological analysis as it helps understanding the hydrological behavior of the DEM without being influenced by the model structural as well as parameter uncertainty. It also reemphasized that SRTM DEM can be a valuable dataset for hydrological analysis provided any error/uncertainty therein is being properly evaluated and characterized.

Assessment of Reference Height Models on Quality of Tandem-X dem

NASA Astrophysics Data System (ADS)

Mirzaee, S.; Motagh, M.; Arefi, H.

2015-12-01

The aim of this study is to investigate the effect of various Global Digital Elevation Models (GDEMs) in producing high-resolution topography model using TanDEM-X (TDX) Coregistered Single Look Slant Range Complex (CoSSC) images. We selected an image acquired on Jun 12th, 2012 over Doroud region in Lorestan, west of Iran and used 4 external digital elevation models in our processing including DLR/ASI X-SAR DEM (SRTM-X, 30m resolution), ASTER GDEM Version 2 (ASTER-GDEMV2, 30m resolution), NASA SRTM Version 4 (SRTM-V4, 90m resolution), and a local photogrammetry-based DEM prepared by National Cartographic Center (NCC DEM, 10m resolution) of Iran. InSAR procedure for DEM generation was repeated four times with each of the four external height references. The quality of each external DEM was initially assessed using ICESat filtered points. Then, the quality of, each TDX-based DEM was assessed using the more precise external DEM selected in the previous step. Results showed that both local (NCC) DEM and SRTM X-band performed the best (RMSE< 9m) for TDX-DEM generation. In contrast, ASTER GDEM v2 and SRTM C-band v4 showed poorer quality.

Effect of DEM mesh size on AnnAGNPS simulation and slope correction.

PubMed

Wang, Xiaoyan; Lin, Q

2011-08-01

The objective of this paper is to study the impact of the mesh size of the digital elevation model (DEM) on terrain attributes within an Annualized AGricultural NonPoint Source pollution (AnnAGNPS) Model simulation at watershed scale and provide a correction of slope gradient for low resolution DEMs. The effect of different grid sizes of DEMs on terrain attributes was examined by comparing eight DEMs (30, 40, 50, 60, 70, 80, 90, and 100 m). The accuracy of the AnnAGNPS stimulation on runoff, sediments, and nutrient loads is evaluated. The results are as follows: (1) Rnoff does not vary much with decrease of DEM resolution whereas soil erosion and total nitrogen (TN) load change prominently. There is little effect on runoff simulation of AnnAGNPS modeling by the amended slope using an adjusted 50 m DEM. (2) A decrease of sediment yield and TN load is observed with an increase of DEM mesh size from 30 to 60 m; a slight decrease of sediment and TN load with the DEM mesh size bigger than 60 m. There is similar trend for total phosphorus (TP) variation, but with less range of variation, the simulation of sediment, TN, and TP increase, in which sediment increase up to 1.75 times compared to the model using unadjusted 50 m DEM. In all, the amended simulation still has a large difference relative to the results using 30 m DEM. AnnAGNPS is less reliable for sediment loading prediction in a small hilly watershed. (3) Resolution of DEM has significant impact on slope gradient. The average, minimum, maximum of slope from the various DEMs reduced obviously with the decrease of DEM precision. For the grade of 0∼15°, the slopes at lower resolution DEM are generally bigger than those at higher resolution DEM. But for the grade bigger than 15°, the slopes at lower resolution DEM are generally smaller than those at higher resolution DEM. So it is necessary to adjust the slope with a fitting equation. A cubic model is used for correction of slope gradient from lower resolution to that from higher resolution. Results for Dage watershed showed that fine meshes are desired to avoid large underestimates of sediment and total nitrogen loads and moderate underestimates of total phosphorus loads even with the slopes for the 50 m DEM adjusted to be more similar to the slopes from the 30 m DEM. Decreasing the mesh size beyond this threshold does not substantially affect the computed runoff flux but generated prediction errors for nitrogen and sediment yields. So the appropriate DEM will control error and make simulation at acceptable level.

Nanomedical strategy to prolong survival period, heighten cure rate, and lower systemic toxicity of S180 mice treated with MTX/MIT.

PubMed

Song, Ning; Zhao, Ming; Wang, Yuji; Hu, Xi; Wu, Jianhui; Jiang, Xueyun; Li, Shan; Cui, Chunying; Peng, Shiqi

2016-01-01

In spite of the usual combination form of methotrexate (MTX)/mitoxantrone (MIT) and various complex combination regimens of MTX/MIT with other anticancer drugs, the survival period, cure rate, and systemic toxicity still need to be improved. For this purpose, a nanostructured amino group-modified mesoporous silica nanoparticles (MSNN)-MTX/MIT was designed. In the preparation, the surface of mesoporous silica nanoparticles (MSNs) was modified with amino groups to form MSNN. The covalent modification of the amino groups on the surface of MSNN with MTX resulted in MSNN-MTX. The loading of MIT into the surface pores of MSNN-MTX produced nanostructured MSNN-MTX/MIT. Compared with the usual combination form (MTX/MIT), nanostructured MSNN-MTX/MIT increased the survival period greatly, heightened the cure rate to a great extent, and lowered the systemic toxicity of the treated S180 mice, significantly. These superior in vivo properties of nanostructured MSNN-MTX/MIT over the usual combination form (MTX/MIT) were correlated with the former selectively releasing MTX and MIT in tumor tissue and inside cancer cells in vitro. The chemical structure and the nanostructure of MSNN-MTX/MIT were characterized using infrared and differential scanning calorimeter spectra as well as transmission electron microscope images, respectively.

Nanomedical strategy to prolong survival period, heighten cure rate, and lower systemic toxicity of S180 mice treated with MTX/MIT

PubMed Central

Song, Ning; Zhao, Ming; Wang, Yuji; Hu, Xi; Wu, Jianhui; Jiang, Xueyun; Li, Shan; Cui, Chunying; Peng, Shiqi

2016-01-01

In spite of the usual combination form of methotrexate (MTX)/mitoxantrone (MIT) and various complex combination regimens of MTX/MIT with other anticancer drugs, the survival period, cure rate, and systemic toxicity still need to be improved. For this purpose, a nanostructured amino group-modified mesoporous silica nanoparticles (MSNN)−MTX/MIT was designed. In the preparation, the surface of mesoporous silica nanoparticles (MSNs) was modified with amino groups to form MSNN. The covalent modification of the amino groups on the surface of MSNN with MTX resulted in MSNN−MTX. The loading of MIT into the surface pores of MSNN−MTX produced nanostructured MSNN−MTX/MIT. Compared with the usual combination form (MTX/MIT), nanostructured MSNN−MTX/MIT increased the survival period greatly, heightened the cure rate to a great extent, and lowered the systemic toxicity of the treated S180 mice, significantly. These superior in vivo properties of nanostructured MSNN−MTX/MIT over the usual combination form (MTX/MIT) were correlated with the former selectively releasing MTX and MIT in tumor tissue and inside cancer cells in vitro. The chemical structure and the nanostructure of MSNN−MTX/MIT were characterized using infrared and differential scanning calorimeter spectra as well as transmission electron microscope images, respectively. PMID:27621591

Evaluation of TanDEM-X elevation data for geomorphological mapping and interpretation in high mountain environments - A case study from SE Tibet, China

NASA Astrophysics Data System (ADS)

Pipaud, Isabel; Loibl, David; Lehmkuhl, Frank

2015-10-01

Digital elevation models (DEMs) are a prerequisite for many different applications in the field of geomorphology. In this context, the two near-global medium resolution DEMs originating from the SRTM and ASTER missions are widely used. For detailed geomorphological studies, particularly in high mountain environments, these datasets are, however, known to have substantial disadvantages beyond their posting, i.e., data gaps and miscellaneous artifacts. The upcoming TanDEM-X DEM is a promising candidate to improve this situation by application of state-of-the-art radar technology, exhibiting a posting of 12 m and less proneness to errors. In this study, we present a DEM processed from a single TanDEM-X CoSSC scene, covering a study area in the extreme relief of the eastern Nyainqêntanglha Range, southeastern Tibet. The potential of the resulting experimental TanDEM-X DEM for geomorphological applications was evaluated by geomorphometric analyses and an assessment of landform cognoscibility and artifacts in comparison to the ASTER GDEM and the recently released SRTM 1″ DEM. Detailed geomorphological mapping was conducted for four selected core study areas in a manual approach, based exclusively on the TanDEM-X DEM and its basic derivates. The results show that the self-processed TanDEM-X DEM yields a detailed and widely consistent landscape representation. It thus fosters geomorphological analysis by visual and quantitative means, allowing delineation of landforms down to footprints of 30 m. Even in this premature state, the TanDEM-X elevation data are widely superior to the ASTER and SRTM datasets, primarily owing to its significantly higher resolution and its lower susceptibility to artifacts that hamper landform interpretation. Conversely, challenges toward interferometric DEM generation were identified, including (i) triangulation facets and missing topographic information resulting from radar layover on steep slopes facing toward the radar sensor, (ii) low coherence values on leeward slopes, (iii) decorrelation effects over water bodies, and (iv) challenges for phase unwrapping in settings of strong topographic contrasts. There is, however, a high probability that these drawbacks can be overcome by applying multiple interferograms exhibiting different perpendicular baselines as planned for the generation of the final TanDEM-X DEM product.

Towards the Optimal Pixel Size of dem for Automatic Mapping of Landslide Areas

NASA Astrophysics Data System (ADS)

Pawłuszek, K.; Borkowski, A.; Tarolli, P.

2017-05-01

Determining appropriate spatial resolution of digital elevation model (DEM) is a key step for effective landslide analysis based on remote sensing data. Several studies demonstrated that choosing the finest DEM resolution is not always the best solution. Various DEM resolutions can be applicable for diverse landslide applications. Thus, this study aims to assess the influence of special resolution on automatic landslide mapping. Pixel-based approach using parametric and non-parametric classification methods, namely feed forward neural network (FFNN) and maximum likelihood classification (ML), were applied in this study. Additionally, this allowed to determine the impact of used classification method for selection of DEM resolution. Landslide affected areas were mapped based on four DEMs generated at 1 m, 2 m, 5 m and 10 m spatial resolution from airborne laser scanning (ALS) data. The performance of the landslide mapping was then evaluated by applying landslide inventory map and computation of confusion matrix. The results of this study suggests that the finest scale of DEM is not always the best fit, however working at 1 m DEM resolution on micro-topography scale, can show different results. The best performance was found at 5 m DEM-resolution for FFNN and 1 m DEM resolution for results. The best performance was found to be using 5 m DEM-resolution for FFNN and 1 m DEM resolution for ML classification.

Design of multifunctional magnetic iron oxide nanoparticles/mitoxantrone-loaded liposomes for both magnetic resonance imaging and targeted cancer therapy.

PubMed

He, Yingna; Zhang, Linhua; Zhu, Dunwan; Song, Cunxian

2014-01-01

Tumor-targeting multifunctional liposomes simultaneously loaded with magnetic iron oxide nanoparticles (MIONs) as a magnetic resonance imaging (MRI) contrast agent and anticancer drug, mitoxantrone (Mit), were developed for targeted cancer therapy and ultrasensitive MRI. The gonadorelin-functionalized MION/Mit-loaded liposome (Mit-GML) showed significantly increased uptake in luteinizing hormone-releasing hormone (LHRH) receptor overexpressing MCF-7 (Michigan Cancer Foundation-7) breast cancer cells over a gonadorelin-free MION/Mit-loaded liposome (Mit-ML) control, as well as in an LHRH receptor low-expressing Sloan-Kettering HER2 3+ Ovarian Cancer (SK-OV-3) cell control, thereby leading to high cytotoxicity against the MCF-7 human breast tumor cell line. The Mit-GML formulation was more effective and less toxic than equimolar doses of free Mit or Mit-ML in the treatment of LHRH receptors overexpressing MCF-7 breast cancer xenografts in mice. Furthermore, the Mit-GML demonstrated much higher T2 enhancement than did Mit-ML controls in vivo. Collectively, the study indicates that the integrated diagnostic and therapeutic design of Mit-GML nanomedicine potentially allows for the image-guided, target-specific treatment of cancer.

Design of multifunctional magnetic iron oxide nanoparticles/mitoxantrone-loaded liposomes for both magnetic resonance imaging and targeted cancer therapy

PubMed Central

He, Yingna; Zhang, Linhua; Zhu, Dunwan; Song, Cunxian

2014-01-01

Tumor-targeting multifunctional liposomes simultaneously loaded with magnetic iron oxide nanoparticles (MIONs) as a magnetic resonance imaging (MRI) contrast agent and anticancer drug, mitoxantrone (Mit), were developed for targeted cancer therapy and ultrasensitive MRI. The gonadorelin-functionalized MION/Mit-loaded liposome (Mit-GML) showed significantly increased uptake in luteinizing hormone–releasing hormone (LHRH) receptor overexpressing MCF-7 (Michigan Cancer Foundation-7) breast cancer cells over a gonadorelin-free MION/Mit-loaded liposome (Mit-ML) control, as well as in an LHRH receptor low-expressing Sloan-Kettering HER2 3+ Ovarian Cancer (SK-OV-3) cell control, thereby leading to high cytotoxicity against the MCF-7 human breast tumor cell line. The Mit-GML formulation was more effective and less toxic than equimolar doses of free Mit or Mit-ML in the treatment of LHRH receptors overexpressing MCF-7 breast cancer xenografts in mice. Furthermore, the Mit-GML demonstrated much higher T2 enhancement than did Mit-ML controls in vivo. Collectively, the study indicates that the integrated diagnostic and therapeutic design of Mit-GML nanomedicine potentially allows for the image-guided, target-specific treatment of cancer. PMID:25187709

Research on a dem Coregistration Method Based on the SAR Imaging Geometry

NASA Astrophysics Data System (ADS)

Niu, Y.; Zhao, C.; Zhang, J.; Wang, L.; Li, B.; Fan, L.

2018-04-01

Due to the systematic error, especially the horizontal deviation that exists in the multi-source, multi-temporal DEMs (Digital Elevation Models), a method for high precision coregistration is needed. This paper presents a new fast DEM coregistration method based on a given SAR (Synthetic Aperture Radar) imaging geometry to overcome the divergence and time-consuming problem of the conventional DEM coregistration method. First, intensity images are simulated for two DEMs under the given SAR imaging geometry. 2D (Two-dimensional) offsets are estimated in the frequency domain using the intensity cross-correlation operation in the FFT (Fast Fourier Transform) tool, which can greatly accelerate the calculation process. Next, the transformation function between two DEMs is achieved via the robust least-square fitting of 2D polynomial operation. Accordingly, two DEMs can be precisely coregistered. Last, two DEMs, i.e., one high-resolution LiDAR (Light Detection and Ranging) DEM and one low-resolution SRTM (Shutter Radar Topography Mission) DEM, covering the Yangjiao landslide region of Chongqing are taken as an example to test the new method. The results indicate that, in most cases, this new method can achieve not only a result as much as 80 times faster than the minimum elevation difference (Least Z-difference, LZD) DEM registration method, but also more accurate and more reliable results.

MERIT DEM: A new high-accuracy global digital elevation model and its merit to global hydrodynamic modeling

NASA Astrophysics Data System (ADS)

Yamazaki, D.; Ikeshima, D.; Neal, J. C.; O'Loughlin, F.; Sampson, C. C.; Kanae, S.; Bates, P. D.

2017-12-01

Digital Elevation Models (DEM) are fundamental data for flood modelling. While precise airborne DEMs are available in developed regions, most parts of the world rely on spaceborne DEMs which include non-negligible height errors. Here we show the most accurate global DEM to date at 90m resolution by eliminating major error components from the SRTM and AW3D DEMs. Using multiple satellite data and multiple filtering techniques, we addressed absolute bias, stripe noise, speckle noise and tree height bias from spaceborne DEMs. After the error removal, significant improvements were found in flat regions where height errors were larger than topography variability, and landscapes features such as river networks and hill-valley structures became clearly represented. We found the topography slope of the previous DEMs was largely distorted in most of world major floodplains (e.g. Ganges, Nile, Niger, Mekong) and swamp forests (e.g. Amazon, Congo, Vasyugan). The developed DEM will largely reduce the uncertainty in both global and regional flood modelling.

Multifunctional nanosheets based on hyaluronic acid modified graphene oxide for tumor-targeting chemo-photothermal therapy

NASA Astrophysics Data System (ADS)

Hou, Lin; Feng, Qianhua; Wang, Yating; Zhang, Huijuan; Jiang, Guixiang; Yang, Xiaomin; Ren, Junxiao; Zhu, Xiali; Shi, Yuyang; Zhang, Zhenzhong

2015-03-01

Graphene oxide (GO) with strong optical absorption in the near-infrared (NIR) region has shown great potential both in photothermal therapy and drug delivery. In this work, hyaluronic acid (HA)-functionalized GO (HA-GO) was successfully synthesized and controlled loading of mitoxantrone (MIT) onto HA-GO via π- π stacking interaction was investigated. The results revealed that drug-loaded nanosheets with high loading efficiency of 45 wt% exhibited pH-sensitive responses to tumor environment. Owing to the receptor-mediated endocytosis, cellular uptake analysis of HA-GO showed enhanced internalization. In vivo optical imaging test demonstrated that HA-GO nanosheets could enhance the targeting ability and residence time in tumor site. Moreover, the anti-tumor activity of free MIT, MIT/GO, and MIT/HA-GO in combination with NIR laser was investigated using human MCF-7 cells. In vitro cytotoxicity study revealed that HA-GO could stand as a biocompatible nanocarrier and MIT/HA-GO demonstrated remarkably higher toxicity than free MIT and MIT/GO, with IC50 of 0.79 µg ml-1. Tumor cell-killing potency was enhanced when MIT/HA-GO were combined with NIR irradiation, and the IC50 of MIT/HA-GO plus laser irradiation was 0.38 µg ml-1. In vivo, MIT/HA-GO plus NIR laser irradiation with the tumor growth inhibition of 93.52 % displayed greater anti-tumor effect compared with free MIT and MIT/GO with or without laser irradiation. Therefore, the MIT/HA-GO nanosheets may potentially be useful for further development of synergistic cancer therapy.

Vom Urknall zum Durchknall

NASA Astrophysics Data System (ADS)

Unzicker, Alexander

Lautstarker Applaus erhob sich im Salon III/IV des Marriott-Hotels von Crystal City im amerikanischen Bundesstaat Virginia. In dem überfüllten Konferenzraum starrten alle wie gebannt auf die Leinwand, wo nicht mehr zu sehen war als ein nüchternes Diagramm aus zahlreichen Punkten und einer geschwungenen Kurve. Nureine eigenartige Personengruppe konnte sich davon zu Emotionen hinreißen lassen - Physiker auf der Jahrestagung der Astronomischen Gesellschaft, die ihren Begeisterungssturm noch minutenlang fortsetzten. Was war geschehen? Die im Diagramm aufgetragenen Daten bestätigten mit einer nie da gewesenen Genauigkeit ein fundamentales Naturgesetz zur Wärmeabstrahlung von heißen Körpern. 1900 von Max Planck entdeckt, leuchtete es nun in geradezu mathematischer Reinheit auf. Noch sensationeller war der Ursprung der Daten - Mikrowellensignale verschiedener Frequenzen, die nicht aus einem irdischen Labor stammten, sondern von einem heißen Urzustand des Universums! Ein Feuerball aus Wasserstoff und Helium, noch ohne jegliche Strukturen, die irgendwann Leben ermöglichen sollten, ließ damals seinem Licht freien Lauf. Mehr als zehn Milliarden Jahre war es bis zu den Detektoren des vom Menschen gebauten Satelliten COBE unterwegs, der wenige Tage zuvor die Daten übertragen hatte. Wenn ich das alles wie einen Film in meiner Vorstellung ablaufen lasse, bekomme ich immer eine Gänsehaut, als würde ich die inzwischen extrem abgekühlte Strahlung tatsächlich spüren. Ihre Gleichverteilung im Raum macht uns auch deutlich, dass wir uns nicht einbilden dürfen, an einem besonderen Ort im Universum zu leben - intelligente Aliens könnten sich seitdem überall entwickelt haben! Sollten sie - was nicht wahrscheinlich ist - uns wirklich von Zeit zu Zeit über die Schulter schauen, dann hätten sie an jenem Nachmittag des 13. Januar 1990, als der Vortrag stattfand, bestimmt anerkennend mit ihrem großen Kopf genickt.

Multifunctional hyaluronic acid modified graphene oxide loaded with mitoxantrone for overcoming drug resistance in cancer

NASA Astrophysics Data System (ADS)

Hou, Lin; Feng, Qianhua; Wang, Yating; Yang, Xiaomin; Ren, Junxiao; Shi, Yuyang; Shan, Xiaoning; Yuan, Yujie; Wang, Yongchao; Zhang, Zhenzhong

2016-01-01

Multifunctional nanosheets (HA-GO/Pluronic) with targeted chemo-photothermal properties were successfully developed for controlled delivery of mitoxantrone (MIT) to overcome multidrug resistance (MDR). In vitro release profiles displayed that both an acidic environment and a NIR laser could trigger and accelerate the release of a drug, which ensured nanosheets were stable in blood circulation and released MIT within tumor cells under laser irradiation. HA-GO/Pluronic nanosheets were taken up into MCF-7/ADR cells via receptor-mediated endocytosis, which further facilitated escapement of P-gp efflux. Compared with MIT solution, MIT/HA-GO/Pluronic showed greater cytotoxicity and increase in cellular MIT accumulation in MCF-7/ADR cells. Cell apoptosis and cell cycle arrest studies also revealed that MIT/HA-GO/Pluronic was more potent than MIT/GO/Pluronic and MIT solution. The anticancer efficacy in vivo was evaluated in MCF-7 and MCF-7/ADR-bearing mice, and inhibition of tumors by MIT/HA-GO/Pluronic with NIR laser irradiation was the most effective among all MIT formulations. In summary, the MIT/HA-GO/Pluronic system had striking functions such as P-gp reversible inhibitor and anticancer efficacy, and could present a promising platform for drug-resistant cancer treatment.

Dynamic Energy Management System for a Smart Microgrid.

PubMed

Venayagamoorthy, Ganesh Kumar; Sharma, Ratnesh K; Gautam, Prajwal K; Ahmadi, Afshin

2016-08-01

This paper presents the development of an intelligent dynamic energy management system (I-DEMS) for a smart microgrid. An evolutionary adaptive dynamic programming and reinforcement learning framework is introduced for evolving the I-DEMS online. The I-DEMS is an optimal or near-optimal DEMS capable of performing grid-connected and islanded microgrid operations. The primary sources of energy are sustainable, green, and environmentally friendly renewable energy systems (RESs), e.g., wind and solar; however, these forms of energy are uncertain and nondispatchable. Backup battery energy storage and thermal generation were used to overcome these challenges. Using the I-DEMS to schedule dispatches allowed the RESs and energy storage devices to be utilized to their maximum in order to supply the critical load at all times. Based on the microgrid's system states, the I-DEMS generates energy dispatch control signals, while a forward-looking network evaluates the dispatched control signals over time. Typical results are presented for varying generation and load profiles, and the performance of I-DEMS is compared with that of a decision tree approach-based DEMS (D-DEMS). The robust performance of the I-DEMS was illustrated by examining microgrid operations under different battery energy storage conditions.

Importance of Grid Center Arrangement

NASA Astrophysics Data System (ADS)

Pasaogullari, O.; Usul, N.

2012-12-01

In Digital Elevation Modeling, grid size is accepted to be the most important parameter. Despite the point density and/or scale of the source data, it is freely decided by the user. Most of the time, arrangement of the grid centers are ignored, even most GIS packages omit the choice of grid center coordinate selection. In our study; importance of the arrangement of grid centers is investigated. Using the analogy between "Raster Grid DEM" and "Bitmap Image", importance of placement of grid centers in DEMs are measured. The study has been conducted on four different grid DEMs obtained from a half ellipsoid. These grid DEMs are obtained in such a way that they are half grid size apart from each other. Resulting grid DEMs are investigated through similarity measures. Image processing scientists use different measures to investigate the dis/similarity between the images and the amount of different information they carry. Grid DEMs are projected to a finer grid in order to co-center. Similarity measures are then applied to each grid DEM pairs. These similarity measures are adapted to DEM with band reduction and real number operation. One of the measures gives function graph and the others give measure matrices. Application of similarity measures to six grid DEM pairs shows interesting results. These four different grid DEMs are created with the same method for the same area, surprisingly; thirteen out of 14 measures state that, the half grid size apart grid DEMs are different from each other. The results indicated that although grid DEMs carry mutual information, they have also additional individual information. In other words, half grid size apart constructed grid DEMs have non-redundant information.; Joint Probability Distributions Function Graphs

MIT domain of Vps4 is a Ca2+-dependent phosphoinositide-binding domain.

PubMed

Iwaya, Naoko; Takasu, Hirotoshi; Goda, Natsuko; Shirakawa, Masahiro; Tanaka, Toshiki; Hamada, Daizo; Hiroaki, Hidekazu

2013-05-01

The microtubule interacting and trafficking (MIT) domain is a small protein module that is conserved in proteins of diverged function, such as Vps4, spastin and sorting nexin 15 (SNX15). The molecular function of the MIT domain is protein-protein interaction, in which the domain recognizes peptides containing MIT-interacting motifs. Recently, we identified an evolutionarily related domain, 'variant' MIT domain at the N-terminal region of the microtubule severing enzyme katanin p60. We found that the domain was responsible for binding to microtubules and Ca(2+). Here, we have examined whether the authentic MIT domains also bind Ca(2+). We found that the loop between the first and second α-helices of the MIT domain binds a Ca(2+) ion. Furthermore, the MIT domains derived from Vps4b and SNX15a showed phosphoinositide-binding activities in a Ca(2+)-dependent manner. We propose that the MIT domain is a novel membrane-associating domain involved in endosomal trafficking.

Vergleich von rekombinanten Vaccinia- und DNA-Vektoren zur Tumorimmuntherapie im C57BL/6-Mausmodell

NASA Astrophysics Data System (ADS)

Johnen, Heiko

2002-10-01

In der vorliegenden Arbeit wurden Tumorimpfstoffe auf der Basis des Plasmid-Vektors pCI, modified vaccinia virus Ankara (MVA) und MVA-infizierten dendritischen Zellen entwickelt und durch Sequenzierung, Western blotting und durchflußzytometrische Analyse überprüft. Die in vivo Wirksamkeit der Vakzinen wurde in verschiedenen Tumormodellen in C57BL/6 Mäusen verglichen. Die auf dem eukaryotischen Expressionsvektor pCI basierende DNA-Vakzinierung induzierte einen sehr wirksamen, antigenspezifischen und langfristigen Schutz vor Muzin, CEA oder beta-Galactosidase exprimierenden Tumoren. Eine MVA-Vakzinierung bietet in den in dieser Arbeit durchgeführten Tumormodellen keinen signifikanten Schutz vor Muzin oder beta-Galactosidase exprimierenden Tumoren. Sowohl humane, als auch murine in vitro generierte dendritische Zellen lassen sich mit MVA – im Vergleich zu anderen viralen Vektoren – sehr gut infizieren. Die Expressionsrate der eingefügten Gene ist aber gering im Vergleich zur Expression in permissiven Wirtszellen des Virus (embryonale Hühnerfibroblasten). Es konnte gezeigt werden, daß eine MVA-Infektion dendritischer Zellen ähnliche Auswirkungen auf den Reifezustand humaner und muriner dendritischer Zellen hat, wie eine Infektion mit replikationskompetenten Vakzinia-Stämmen, und außerdem die Hochregulation von CD40 während der terminalen Reifung von murinen dendritischen Zellen inhibiert wird. Die während der langfristigen in vitro Kultur auf CEF-Zellen entstandenen Deletionen im MVA Genom führten zu einer starken Attenuierung und dem Verlust einiger Gene, die immunmodulatorische Proteine kodieren, jedoch nicht zu einer Verminderung des zytopathischen Effekts in dendritischen Zellen. Die geringe Expressionsrate und die beobachtete Inhibition der Expression kostimulatorischer Moleküle auf dendritischen Zellen kann für eine wenig effektive Induktion einer Immunantwort in MVA vakzinierten Tieren durch cross priming oder die direkte Infektion antigenpräsentierender Zellen verantwortlich sein. Durch die Modifikation einer Methode zur intrazellulären IFN-gamma Färbung konnten in vakzinierten Mäusen tumorantigenspezifische CTL sensitiv und quantitativ detektiert werden. Die so bestimmte CTL-Frequenz, nicht jedoch die humorale Antwort, korrelierte mit der in vivo Wirksamkeit der verschiedenen Vakzinen: DNA vakzinierte Tiere entwickeln starke tumorantigenspezifische CTL-Antworten, wohingegen in MVA-vakzinierten Tieren überwiegend gegen virale Epitope gerichtete CD4 und CD8-T-Zellen detektiert wurden. Die Wirksamkeit der pCI-DNA-Vakzine spricht für die Weiterentwicklung in weiteren präklinischen Mausmodellen, beispielsweise unter Verwendung von MUC1 oder HLA-A2 transgenen Mäusen. Die Methoden zur Detektion Tumorantigen-spezifischer CTL in 96-Loch-Mikrotiterplatten können dabei zur systematischen Suche nach im Menschen immundominanten T-Zell-Epitopen im Muzin-Molekül genutzt werden. Der durchgeführte Vergleich der auf den Vektoren pCI und MVA basierenden Vakzinen und die Analyse neuerer Publikationen führen zu dem Ergebniss, daß vor allem DNA-Vakzinen in Zukunft eine wichtige Rolle bei der Entwicklung von aktiven Tumorimpfstoffen spielen werden. Rekombinante MVA-Viren, eventuell in Kombination mit DNA- oder anderen Vektoren, haben sich dagegen in zahlreichen Studien als wirksame Impfstoffe zur Kontrolle von durch Pathogene hervorgerufenen Infektionserkrankungen erwiesen. In this study, tumor vaccines based on the plasmid pCI, the attenuated vaccinia virus strain modified vaccinia virus Ankara (MVA) and MVA-infected dendritic cells were constructed and characterized by sequencing, Western blot and flow cytometric analysis. The efficiency to induce tumor immunity in vivo was compared in several C57BL/6 mouse tumor models. Naked DNA Vaccination based on the eukaryotic expression vector pCI did induce very effective, antigen-specific and long-term protection against tumor cell lines expressing mucin, CEA or beta-Gal whereas MVA vaccination did not elicit protective immunity against Mucin or beta-Gal expressing tumors. MVA does infect human or murine in vitro generated dendritic cells very efficiently compared to other viral vectors, however expression levels of the inserted antigens in dendritic cells are significantly lower than in permissive host cells (chicken embryo fibroblasts). It could be shown that the effect of MVA infection on the maturation status of dendritic cells is similar to the effects described for dendritic cells infected with replication competent vaccinia strains. In addition it was shown that the upregulation of the important costimulatory molecule CD40 through LPS stimulation is strongly inhibited in MVA infected cells. During passage in tissue culture, MVA has accumulated a number of large deletions, including a number of immunomodulatory molecules and resulting in a strong attenuation. However the strong cytopathic effect on dendritic cells is maintained. The low level of expression and the effect on dendritic cell maturation may be responsible for the failure of MVA to induce tumor immunity through either cross presentation or direct infection of antigen presenting cells. To detect and quantify tumor-antigen-specific CTL a method based on intracellular IFN-gamma staining was modified and it could be shown that the cellular – but not the humoral – response does correlate with in vivo protection: DNA but not MVA vaccines do induce high levels of tumorantigen-specific CTL whereas MVA-vaccines do induce strong and long lasting CD4 and CD8-T-cell responses against vaccinia antigens. The excellent protection induced by pCI-DNA-vaccination in different tumor models does encourage us to further investigate the elicitation of tumor immunity in MUC1 or HLA-A2 transgenic mice. In mice transgenic for human MHC-I, the IFN-gamma staining protocol could be used to systematically screen for mucin T-cell epitopes that are relevant in humans.

Helicobacter sp. MIT 01-6451 infection during fetal and neonatal life in laboratory mice.

PubMed

Yamanaka, Hitoki; Nakanishi, Tai; Takagi, Toshikazu; Ohsawa, Makiko; Kubo, Noriaki; Yamamoto, Naoto; Takemoto, Takahira; Ohsawa, Kazutaka

2015-01-01

Helicobacter sp. MIT 01-6451 has been detected in SPF mice kept in Japan. To characterize strain MIT 01-6451, its infection route during fetal and neonatal life and effects on pregnancy were investigated using immunocompetent and immunodeficient mouse strains (BALB/c, C57BL/6, and SCID). MIT 01-6451 was detected in the uterus, vagina, and mammary glands of 50% of infected SCID mice, whereas these tissues were all negative in immunocompetent mice. No fetal infections with MIT 01-6451 were detected at 16-18 days after pregnancy in any mouse strain. In newborn mice, MIT 01-6451 was detected in intestinal tissue of C57BL/6 and SCID mice at 9-11 days after birth, but not in BALB/c mice. The IgA and IgG titers to MIT 01-6451 in sera of C57BL/6 female mice were significantly lower than those of BALB/c mice. Although no significant differences in the number of newborns per litter were observed between MIT 01-6451-infected and MIT 01-6451-free dams, the birth rate was lower in infected SCID mice than in control SCID mice. The present results indicated that MIT 01-6451 infects newborn mice after birth rather than by vertical transmission to the fetus via the placenta and that MIT 01-6451 infection shows opportunistically negative effects on the birth rate. In addition, the maternal immune response may affect infection of newborn mice with MIT 01-6451 through breast milk.

Vitamin E succinate-conjugated F68 micelles for mitoxantrone delivery in enhancing anticancer activity

PubMed Central

Liu, Yuling; Xu, Yingqi; Wu, Minghui; Fan, Lijiao; He, Chengwei; Wan, Jian-Bo; Li, Peng; Chen, Meiwan; Li, Hui

2016-01-01

Mitoxantrone (MIT) is a chemotherapeutic agent with promising anticancer efficacy. In this study, Pluronic F68-vitamine E succinate (F68-VES) amphiphilic polymer micelles were developed for delivering MIT and enhancing its anticancer activity. MIT-loaded F68–VES (F68–VES/MIT) micelles were prepared via the solvent evaporation method with self-assembly under aqueous conditions. F68–VES/MIT micelles were found to be of optimal particle size with the narrow size distribution. Transmission electron microscopy images of F68–VES/MIT micelles showed homogeneous spherical shapes and smooth surfaces. F68–VES micelles had a low critical micelle concentration value of 3.311 mg/L, as well as high encapsulation efficiency and drug loading. Moreover, F68–VES/MIT micelles were stable in the presence of fetal bovine serum for 24 hours and maintained sustained drug release in vitro. Remarkably, the half maximal inhibitory concentration (IC50) value of F68–VES/MIT micelles was lower than that of free MIT in both MDA-MB-231 and MCF-7 cells (two human breast cancer cell lines). In addition, compared with free MIT, there was an increased trend of apoptosis and cellular uptake of F68–VES/MIT micelles in MDA-MB-231 cells. Taken together, these results indicated that F68–VES polymer micelles were able to effectively deliver MIT and largely improve its potency in cancer therapy. PMID:27471384

Bathymetric survey of water reservoirs in north-eastern Brazil based on TanDEM-X satellite data.

PubMed

Zhang, Shuping; Foerster, Saskia; Medeiros, Pedro; de Araújo, José Carlos; Motagh, Mahdi; Waske, Bjoern

2016-11-15

Water scarcity in the dry season is a vital problem in dryland regions such as northeastern Brazil. Water supplies in these areas often come from numerous reservoirs of various sizes. However, inventory data for these reservoirs is often limited due to the expense and time required for their acquisition via field surveys, particularly in remote areas. Remote sensing techniques provide a valuable alternative to conventional reservoir bathymetric surveys for water resource management. In this study single pass TanDEM-X data acquired in bistatic mode were used to generate digital elevation models (DEMs) in the Madalena catchment, northeastern Brazil. Validation with differential global positioning system (DGPS) data from field measurements indicated an absolute elevation accuracy of approximately 1m for the TanDEM-X derived DEMs (TDX DEMs). The DEMs derived from TanDEM-X data acquired at low water levels show significant advantages over bathymetric maps derived from field survey, particularly with regard to coverage, evenly distributed measurements and replication of reservoir shape. Furthermore, by mapping the dry reservoir bottoms with TanDEM-X data, TDX DEMs are free of emergent and submerged macrophytes, independent of water depth (e.g. >10m), water quality and even weather conditions. Thus, the method is superior to other existing bathymetric mapping approaches, particularly for inland water bodies. The proposed approach relies on (nearly) dry reservoir conditions at times of image acquisition and is thus restricted to areas that show considerable water levels variations. However, comparisons between TDX DEM and the bathymetric map derived from field surveys show that the amount of water retained during the dry phase has only marginal impact on the total water volume derivation from TDX DEM. Overall, DEMs generated from bistatic TanDEM-X data acquired in low water periods constitute a useful and efficient data source for deriving reservoir bathymetry and show great potential in large scale application. Copyright © 2016 Elsevier B.V. All rights reserved.

Merging of an EET CInSAR DEM with the SRTM DEM

NASA Astrophysics Data System (ADS)

Wegmuller, Urs; Wiesmann, Andreas; Santoro, Maurizio

2010-03-01

Cross-interferometry (CInSAR) using ERS-2 and ENVISAT ASAR SAR data acquired in the ERS like mode IS2 at VV-polarization with perpendicular baselines of approximately 2 kilometers permits generation of digital elevation models (DEMs). Thanks to the long perpendicular baselines CInSAR has a good potential to generate accurate DEMs over relatively flat terrain. Over sloped terrain the topographic phase gradients get very high and the signals decorrelate if the carrier frequency difference and the baseline effects do not compensate any more. As a result phase unwrapping gets very difficult so that often no reliable solution is obtained for hilly terrain, resulting in DEMs with significant spatial gaps.Spatial gaps in ERS-2 ENVISAT Tandem (EET) CInSAR DEMs over hilly terrain are clearly an important limitation to the utility of these DEMs. On the other hand the high quality achieved over relatively flat terrain is of high interest. As an attempt to significantly improve the utility of the "good information" contained in the CInSAR DEM we developed a methodology to merge a CInSAR DEM with another available DEM, e.g. the SRTM DEM.The methodology was applied to an area in California, USA, including relatively flat terrain belonging to the Mohave desert as well as hilly to mountainous terrain of the San Gabriel and Tehachapi Mountains.

Uncertainty Assessment and Weight Map Generation for Efficient Fusion of Tandem-X and CARTOSAT-1 Dems

NASA Astrophysics Data System (ADS)

Bagheri, H.; Schmitt, M.; Zhu, X. X.

2017-05-01

Recently, with InSAR data provided by the German TanDEM-X mission, a new global, high-resolution Digital Elevation Model (DEM) has been produced by the German Aerospace Center (DLR) with unprecedented height accuracy. However, due to SAR-inherent sensor specifics, its quality decreases over urban areas, making additional improvement necessary. On the other hand, DEMs derived from optical remote sensing imagery, such as Cartosat-1 data, have an apparently greater resolution in urban areas, making their fusion with TanDEM-X elevation data a promising perspective. The objective of this paper is two-fold: First, the height accuracies of TanDEM-X and Cartosat-1 elevation data over different land types are empirically evaluated in order to analyze the potential of TanDEM-XCartosat- 1 DEM data fusion. After the quality assessment, urban DEM fusion using weighted averaging is investigated. In this experiment, both weight maps derived from the height error maps delivered with the DEM data, as well as more sophisticated weight maps predicted by a procedure based on artificial neural networks (ANNs) are compared. The ANN framework employs several features that can describe the height residual performance to predict the weights used in the subsequent fusion step. The results demonstrate that especially the ANN-based framework is able to improve the quality of the final DEM through data fusion.

Representation

DTIC Science & Technology

2006-09-01

two weeks to arrive. Source: http://beergame.mit.edu/ Permission Granted – MIT Supply Chain Forum 2005 Professor Sterman –Sloan School of...Management - MITSource: http://web.mit.edu/jsterman/www/ SDG /beergame.html Rules of Engagement The MIT Beer Game Simulation 04-04 Slide Number 10 Professor...Sterman –Sloan School of Management - MITSource: http://web.mit.edu/jsterman/www/ SDG /beergame.html What is the Significance of Representation

Stochastic Downscaling of Digital Elevation Models

NASA Astrophysics Data System (ADS)

Rasera, Luiz Gustavo; Mariethoz, Gregoire; Lane, Stuart N.

2016-04-01

High-resolution digital elevation models (HR-DEMs) are extremely important for the understanding of small-scale geomorphic processes in Alpine environments. In the last decade, remote sensing techniques have experienced a major technological evolution, enabling fast and precise acquisition of HR-DEMs. However, sensors designed to measure elevation data still feature different spatial resolution and coverage capabilities. Terrestrial altimetry allows the acquisition of HR-DEMs with centimeter to millimeter-level precision, but only within small spatial extents and often with dead ground problems. Conversely, satellite radiometric sensors are able to gather elevation measurements over large areas but with limited spatial resolution. In the present study, we propose an algorithm to downscale low-resolution satellite-based DEMs using topographic patterns extracted from HR-DEMs derived for example from ground-based and airborne altimetry. The method consists of a multiple-point geostatistical simulation technique able to generate high-resolution elevation data from low-resolution digital elevation models (LR-DEMs). Initially, two collocated DEMs with different spatial resolutions serve as an input to construct a database of topographic patterns, which is also used to infer the statistical relationships between the two scales. High-resolution elevation patterns are then retrieved from the database to downscale a LR-DEM through a stochastic simulation process. The output of the simulations are multiple equally probable DEMs with higher spatial resolution that also depict the large-scale geomorphic structures present in the original LR-DEM. As these multiple models reflect the uncertainty related to the downscaling, they can be employed to quantify the uncertainty of phenomena that are dependent on fine topography, such as catchment hydrological processes. The proposed methodology is illustrated for a case study in the Swiss Alps. A swissALTI3D HR-DEM (with 5 m resolution) and a SRTM-derived LR-DEM from the Western Alps are used to downscale a SRTM-based LR-DEM from the eastern part of the Alps. The results show that the method is capable of generating multiple high-resolution synthetic DEMs that reproduce the spatial structure and statistics of the original DEM.

Evaluation of TanDEM-X DEMs on selected Brazilian sites: Comparison with SRTM, ASTER GDEM and ALOS AW3D30

NASA Astrophysics Data System (ADS)

Grohmann, Carlos H.

2018-06-01

A first assessment of the TanDEM-X DEMs over Brazilian territory is presented through a comparison with SRTM, ASTER GDEM and ALOS AW3D30 DEMs in seven study areas with distinct geomorphological contexts, vegetation coverage and land use. Visual analysis and elevation histograms point to a finer effective spatial resolution of TanDEM-X compared to SRTM and ASTER GDEM. In areas of open vegetation, TanDEM-X lower elevations indicate a better penetration of the radar signal. DEMs of differences (DoDs) allowed the identification of issues inherent to the production methods of the analyzed DEMs, such as mast oscillations in SRTM data and mismatch between adjacent scenes in ASTER GDEM and ALOS AW3D30. A systematic difference in elevations between TanDEM-X 12m, TanDEM-X 30m and SRTM was observed in the steep slopes of the coastal ranges, related to the moving-window process used to resample the 12m data to a 30m pixel size. Due its simplicity, it is strongly recommended to produce a DoD with SRTM before using ASTER GDEM or ALOS AW3D30 in any analysis, to evaluate if the area of interest is affected by these problems. The DoDs also highlighted changes in land use in the time span between the acquisition of SRTM (2000) and TanDEM-X (2013) data, whether by natural causes or by human interference in the environment.

Small catchments DEM creation using Unmanned Aerial Vehicles

NASA Astrophysics Data System (ADS)

Gafurov, A. M.

2018-01-01

Digital elevation models (DEM) are an important source of information on the terrain, allowing researchers to evaluate various exogenous processes. The higher the accuracy of DEM the better the level of the work possible. An important source of data for the construction of DEMs are point clouds obtained with terrestrial laser scanning (TLS) and unmanned aerial vehicles (UAV). In this paper, we present the results of constructing a DEM on small catchments using UAVs. Estimation of the UAV DEM showed comparable accuracy with the TLS if real time kinematic Global Positioning System (RTK-GPS) ground control points (GCPs) and check points (CPs) were used. In this case, the main source of errors in the construction of DEMs are the errors in the referencing of survey results.

a Method of Generating dem from Dsm Based on Airborne Insar Data

NASA Astrophysics Data System (ADS)

Lu, W.; Zhang, J.; Xue, G.; Wang, C.

2018-04-01

Traditional methods of terrestrial survey to acquire DEM cannot meet the requirement of acquiring large quantities of data in real time, but the DSM can be quickly obtained by using the dual antenna synthetic aperture radar interferometry and the DEM generated by the DSM is more fast and accurate. Therefore it is most important to acquire DEM from DSM based on airborne InSAR data. This paper aims to the method that generate DEM from DSM accurately. Two steps in this paper are applied to acquire accurate DEM. First of all, when the DSM is generated by interferometry, unavoidable factors such as overlay and shadow will produce gross errors to affect the data accuracy, so the adaptive threshold segmentation method is adopted to remove the gross errors and the threshold is selected according to the coherence of the interferometry. Secondly DEM will be generated by the progressive triangulated irregular network densification filtering algorithm. Finally, experimental results are compared with the existing high-precision DEM results. The results show that this method can effectively filter out buildings, vegetation and other objects to obtain the high-precision DEM.

Mithramycin-loaded mPEG-PLGA nanoparticles exert potent antitumor efficacy against pancreatic carcinoma

PubMed Central

Liu, Xu-Jie; Li, Liang; Liu, Xiu-Jun; Li, Yi; Zhao, Chun-Yan; Wang, Rui-Qi; Zhen, Yong-Su

2017-01-01

Previous studies have shown that mithramycin A (MIT) is a promising candidate for the treatment of pancreatic carcinoma through inhibiting transcription factor Sp1. However, systemic toxicities may limit its clinical application. Here, we report a rationally designed formulation of MIT-loaded nanoparticles (MIT-NPs) with a small size and sustained release for improved passive targeting and enhanced therapeutic efficacy. Nearly spherical MIT-NPs with a mean particle size of 25.0±4.6 nm were prepared by encapsulating MIT into methoxy poly(ethylene glycol)-block-poly(d,l-lactic-co-glycolic acid) (mPEG-PLGA) nanoparticles (NPs) with drug loading of 2.11%±0.51%. The in vitro release of the MIT-NPs lasted for >48 h with a sustained-release pattern. The cytotoxicity of MIT-NPs to human pancreatic cancer BxPC-3 and MIA Paca-2 cells was comparable to that of free MIT. Determined by flow cytometry and confocal microscopy, the NPs internalized into the cells quickly and efficiently, reaching the peak level at 1–2 h. In vivo fluorescence imaging showed that the prepared NPs were gradually accumulated in BxPC-3 and MIA Paca-2 xenografts and retained for 168 h. The fluorescence intensity in both BxPC-3 and MIA Paca-2 tumors was much stronger than that of various tested organs. Therapeutic efficacy was evaluated with the poorly permeable BxPC-3 pancreatic carcinoma xenograft model. At a well-tolerated dose of 2 mg/kg, MIT-NPs suppressed BxPC-3 tumor growth by 96%. Compared at an equivalent dose, MIT-NPs exerted significantly higher therapeutic effect than free MIT (86% versus 51%, P<0.01). Moreover, the treatment of MIT and MIT-NPs reduced the expression level of oncogene c-Myc regulated by Sp1, and notably, both of them decreased the protein level of CD47. In summary, the novel formulation of MIT-NPs shows highly therapeutic efficacy against pancreatic carcinoma xenograft. In addition, MIT-NPs can downregulate CD47 expression, implying that it might play a positive role in cancer immunotherapy. PMID:28769562

High-resolution digital elevation models from single-pass TanDEM-X interferometry over mountainous regions: A case study of Inylchek Glacier, Central Asia

NASA Astrophysics Data System (ADS)

Neelmeijer, Julia; Motagh, Mahdi; Bookhagen, Bodo

2017-08-01

This study demonstrates the potential of using single-pass TanDEM-X (TDX) radar imagery to analyse inter- and intra-annual glacier changes in mountainous terrain. Based on SAR images acquired in February 2012, March 2013 and November 2013 over the Inylchek Glacier, Kyrgyzstan, we discuss in detail the processing steps required to generate three reliable digital elevation models (DEMs) with a spatial resolution of 10 m that can be used for glacial mass balance studies. We describe the interferometric processing steps and the influence of a priori elevation information that is required to model long-wavelength topographic effects. We also focus on DEM alignment to allow optimal DEM comparisons and on the effects of radar signal penetration on ice and snow surface elevations. We finally compare glacier elevation changes between the three TDX DEMs and the C-band shuttle radar topography mission (SRTM) DEM from February 2000. We introduce a new approach for glacier elevation change calculations that depends on the elevation and slope of the terrain. We highlight the superior quality of the TDX DEMs compared to the SRTM DEM, describe remaining DEM uncertainties and discuss the limitations that arise due to the side-looking nature of the radar sensor.

Helicobacter sp. MIT 01-6451 infection during fetal and neonatal life in laboratory mice

PubMed Central

Yamanaka, Hitoki; Nakanishi, Tai; Takagi, Toshikazu; Ohsawa, Makiko; Kubo, Noriaki; Yamamoto, Naoto; Takemoto, Takahira; Ohsawa, Kazutaka

2015-01-01

Helicobacter sp. MIT 01-6451 has been detected in SPF mice kept in Japan. To characterize strain MIT 01-6451, its infection route during fetal and neonatal life and effects on pregnancy were investigated using immunocompetent and immunodeficient mouse strains (BALB/c, C57BL/6, and SCID). MIT 01-6451 was detected in the uterus, vagina, and mammary glands of 50% of infected SCID mice, whereas these tissues were all negative in immunocompetent mice. No fetal infections with MIT 01-6451 were detected at 16–18 days after pregnancy in any mouse strain. In newborn mice, MIT 01-6451 was detected in intestinal tissue of C57BL/6 and SCID mice at 9–11 days after birth, but not in BALB/c mice. The IgA and IgG titers to MIT 01-6451 in sera of C57BL/6 female mice were significantly lower than those of BALB/c mice. Although no significant differences in the number of newborns per litter were observed between MIT 01-6451-infected and MIT 01-6451-free dams, the birth rate was lower in infected SCID mice than in control SCID mice. The present results indicated that MIT 01-6451 infects newborn mice after birth rather than by vertical transmission to the fetus via the placenta and that MIT 01-6451 infection shows opportunistically negative effects on the birth rate. In addition, the maternal immune response may affect infection of newborn mice with MIT 01-6451 through breast milk. PMID:26134357

Shuttle radar DEM hydrological correction for erosion modelling in small catchments

NASA Astrophysics Data System (ADS)

Jarihani, Ben; Sidle, Roy; Bartley, Rebecca

2016-04-01

Digital Elevation Models (DEMs) that accurately replicate both landscape form and processes are critical to support modelling of environmental processes. Catchment and hillslope scale runoff and sediment processes (i.e., patterns of overland flow, infiltration, subsurface stormflow and erosion) are all topographically mediated. In remote and data-scarce regions, high resolution DEMs (LiDAR) are often not available, and moderate to course resolution digital elevation models (e.g., SRTM) have difficulty replicating detailed hydrological patterns, especially in relatively flat landscapes. Several surface reconditioning algorithms (e.g., Smoothing) and "Stream burning" techniques (e.g., Agree or ANUDEM), in conjunction with representation of the known stream networks, have been used to improve DEM performance in replicating known hydrology. Detailed stream network data are not available at regional and national scales, but can be derived at local scales from remotely-sensed data. This research explores the implication of high resolution stream network data derived from Google Earth images for DEM hydrological correction, instead of using course resolution stream networks derived from topographic maps. The accuracy of implemented method in producing hydrological-efficient DEMs were assessed by comparing the hydrological parameters derived from modified DEMs and limited high-resolution airborne LiDAR DEMs. The degree of modification is dominated by the method used and availability of the stream network data. Although stream burning techniques improve DEMs hydrologically, these techniques alter DEM characteristics that may affect catchment boundaries, stream position and length, as well as secondary terrain derivatives (e.g., slope, aspect). Modification of a DEM to better reflect known hydrology can be useful, however, knowledge of the magnitude and spatial pattern of the changes are required before using a DEM for subsequent analyses.

The effect of averaging adjacent planes for artifact reduction in matrix inversion tomosynthesis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Godfrey, Devon J.; Page McAdams, H.; Dobbins, James T. III

2013-02-15

Purpose: Matrix inversion tomosynthesis (MITS) uses linear systems theory and knowledge of the imaging geometry to remove tomographic blur that is present in conventional backprojection tomosynthesis reconstructions, leaving in-plane detail rendered clearly. The use of partial-pixel interpolation during the backprojection process introduces imprecision in the MITS modeling of tomographic blur, and creates low-contrast artifacts in some MITS planes. This paper examines the use of MITS slabs, created by averaging several adjacent MITS planes, as a method for suppressing partial-pixel artifacts. Methods: Human chest tomosynthesis projection data, acquired as part of an IRB-approved pilot study, were used to generate MITS planes,more » three-plane MITS slabs (MITSa3), five-plane MITS slabs (MITSa5), and seven-plane MITS slabs (MITSa7). These were qualitatively examined for partial-pixel artifacts and the visibility of normal and abnormal anatomy. Additionally, small (5 mm) subtle pulmonary nodules were simulated and digitally superimposed upon human chest tomosynthesis projection images, and their visibility was qualitatively assessed in the different reconstruction techniques. Simulated images of a thin wire were used to generate modulation transfer function (MTF) and slice-sensitivity profile curves for the different MITS and MITS slab techniques, and these were examined for indications of partial-pixel artifacts and frequency response uniformity. Finally, mean-subtracted, exposure-normalized noise power spectra (ENNPS) estimates were computed and compared for MITS and MITS slab reconstructions, generated from 10 sets of tomosynthesis projection data of an acrylic slab. The simulated in-plane MTF response of each technique was also combined with the square root of the ENNPS estimate to yield stochastic signal-to-noise ratio (SNR) information about the different reconstruction techniques. Results: For scan angles of 20 Degree-Sign and 5 mm plane separation, seven MITS planes must be averaged to sufficiently remove partial-pixel artifacts. MITSa7 does appear to subtly reduce the contrast of high-frequency 'edge' information, but the removal of partial-pixel artifacts makes the appearance of low-contrast, fine-detail anatomy even more conspicuous in MITSa7 slices. MITSa7 also appears to render simulated subtle 5 mm pulmonary nodules with greater visibility than MITS alone, in both the open lung and regions overlying the mediastinum. Finally, the MITSa7 technique reduces stochastic image variance, though the in-plane stochastic SNR (for very thin objects which do not span multiple MITS planes) is only improved at spatial frequencies between 0.05 and 0.20 cycles/mm. Conclusions: The MITSa7 method is an improvement over traditional single-plane MITS for thoracic imaging and the pulmonary nodule detection task, and thus the authors plan to use the MITSa7 approach for all future MITS research at the authors' institution.« less

The effect of averaging adjacent planes for artifact reduction in matrix inversion tomosynthesis.

PubMed

Godfrey, Devon J; McAdams, H Page; Dobbins, James T

2013-02-01

Matrix inversion tomosynthesis (MITS) uses linear systems theory and knowledge of the imaging geometry to remove tomographic blur that is present in conventional backprojection tomosynthesis reconstructions, leaving in-plane detail rendered clearly. The use of partial-pixel interpolation during the backprojection process introduces imprecision in the MITS modeling of tomographic blur, and creates low-contrast artifacts in some MITS planes. This paper examines the use of MITS slabs, created by averaging several adjacent MITS planes, as a method for suppressing partial-pixel artifacts. Human chest tomosynthesis projection data, acquired as part of an IRB-approved pilot study, were used to generate MITS planes, three-plane MITS slabs (MITSa3), five-plane MITS slabs (MITSa5), and seven-plane MITS slabs (MITSa7). These were qualitatively examined for partial-pixel artifacts and the visibility of normal and abnormal anatomy. Additionally, small (5 mm) subtle pulmonary nodules were simulated and digitally superimposed upon human chest tomosynthesis projection images, and their visibility was qualitatively assessed in the different reconstruction techniques. Simulated images of a thin wire were used to generate modulation transfer function (MTF) and slice-sensitivity profile curves for the different MITS and MITS slab techniques, and these were examined for indications of partial-pixel artifacts and frequency response uniformity. Finally, mean-subtracted, exposure-normalized noise power spectra (ENNPS) estimates were computed and compared for MITS and MITS slab reconstructions, generated from 10 sets of tomosynthesis projection data of an acrylic slab. The simulated in-plane MTF response of each technique was also combined with the square root of the ENNPS estimate to yield stochastic signal-to-noise ratio (SNR) information about the different reconstruction techniques. For scan angles of 20° and 5 mm plane separation, seven MITS planes must be averaged to sufficiently remove partial-pixel artifacts. MITSa7 does appear to subtly reduce the contrast of high-frequency "edge" information, but the removal of partial-pixel artifacts makes the appearance of low-contrast, fine-detail anatomy even more conspicuous in MITSa7 slices. MITSa7 also appears to render simulated subtle 5 mm pulmonary nodules with greater visibility than MITS alone, in both the open lung and regions overlying the mediastinum. Finally, the MITSa7 technique reduces stochastic image variance, though the in-plane stochastic SNR (for very thin objects which do not span multiple MITS planes) is only improved at spatial frequencies between 0.05 and 0.20 cycles∕mm. The MITSa7 method is an improvement over traditional single-plane MITS for thoracic imaging and the pulmonary nodule detection task, and thus the authors plan to use the MITSa7 approach for all future MITS research at the authors' institution.

Arctic Digital Elevation Models (DEMs) generated by Surface Extraction from TIN-Based Searchspace Minimization (SETSM) algorithm from RPCs-based Imagery

NASA Astrophysics Data System (ADS)

Noh, M. J.; Howat, I. M.; Porter, C. C.; Willis, M. J.; Morin, P. J.

2016-12-01

The Arctic is undergoing rapid change associated with climate warming. Digital Elevation Models (DEMs) provide critical information for change measurement and infrastructure planning in this vulnerable region, yet the existing quality and coverage of DEMs in the Arctic is poor. Low contrast and repeatedly-textured surfaces, such as snow and glacial ice and mountain shadows, all common in the Arctic, challenge existing stereo-photogrammetric techniques. Submeter resolution, stereoscopic satellite imagery with high geometric and radiometric quality, and wide spatial coverage are becoming increasingly accessible to the scientific community. To utilize these imagery for extracting DEMs at a large scale over glaciated and high latitude regions we developed the Surface Extraction from TIN-based Searchspace Minimization (SETSM) algorithm. SETSM is fully automatic (i.e. no search parameter settings are needed) and uses only the satellite rational polynomial coefficients (RPCs). Using SETSM, we have generated a large number of DEMs (> 100,000 scene pair) from WorldView, GeoEye and QuickBird stereo images collected by DigitalGlobe Inc. and archived by the Polar Geospatial Center (PGC) at the University of Minnesota through an academic licensing program maintained by the US National Geospatial-Intelligence Agency (NGA). SETSM is the primary DEM generation software for the US National Science Foundation's ArcticDEM program, with the objective of generating high resolution (2-8m) topography for the entire Arctic landmass, including seamless DEM mosaics and repeat DEM strips for change detection. ArcticDEM is collaboration between multiple US universities, governmental agencies and private companies, as well as international partners assisting with quality control and registration. ArcticDEM is being produced using the petascale Blue Waters supercomputer at the National Center for Supercomputer Applications at the University of Illinois. In this paper, we introduce the SETSM algorithm and the processing system used for the ArcticDEM project, as well as provide notable examples of ArcticDEM products.

What is the effect of LiDAR-derived DEM resolution on large-scale watershed model results?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ping Yang; Daniel B. Ames; Andre Fonseca

This paper examines the effect of raster cell size on hydrographic feature extraction and hydrological modeling using LiDAR derived DEMs. LiDAR datasets for three experimental watersheds were converted to DEMs at various cell sizes. Watershed boundaries and stream networks were delineated from each DEM and were compared to reference data. Hydrological simulations were conducted and the outputs were compared. Smaller cell size DEMs consistently resulted in less difference between DEM-delineated features and reference data. However, minor differences been found between streamflow simulations resulted for a lumped watershed model run at daily simulations aggregated at an annual average. These findings indicatemore » that while higher resolution DEM grids may result in more accurate representation of terrain characteristics, such variations do not necessarily improve watershed scale simulation modeling. Hence the additional expense of generating high resolution DEM's for the purpose of watershed modeling at daily or longer time steps may not be warranted.« less

Which DEM is best for analyzing fluvial landscape development in mountainous terrains?

NASA Astrophysics Data System (ADS)

Boulton, Sarah J.; Stokes, Martin

2018-06-01

Regional studies of fluvial landforms and long-term (Quaternary) landscape development in remote mountain landscapes routinely use satellite-derived DEM data sets. The SRTM and ASTER DEMs are the most commonly utilised because of their longer availability, free cost, and ease of access. However, rapid technological developments mean that newer and higher resolution DEM data sets such as ALOS World 3D (AW3D) and TanDEM-X are being released to the scientific community. Geomorphologists are thus faced with an increasingly problematic challenge of selecting an appropriate DEM for their landscape analyses. Here, we test the application of four medium resolution DEM products (30 m = SRTM, ASTER, AW3D; 12 m = TanDEM-X) for qualitative and quantitative analysis of a fluvial mountain landscape using the Dades River catchment (High Atlas Mountains, Morocco). This landscape comprises significant DEM remote sensing challenges, notably a high mountain relief, steep slopes, and a deeply incised high sinuosity drainage network with narrow canyon/gorge reaches. Our goal was to see which DEM produced the most representative best fit drainage network and meaningful quantification. To achieve this, we used ArcGIS and Stream Profiler platforms to generate catchment hillshade and slope rasters and to extract drainage network, channel long profile and channel slope, and area data. TanDEM-X produces the clearest landscape representation but with channel routing errors in localised high relief areas. Thirty-metre DEMs are smoother and less detailed, but the AW3D shows the closest fit to the real drainage network configuration. The TanDEM-X elevation values are the closest to field-derived GPS measurements. Long profiles exhibit similar shapes but with minor differences in length, elevation, and the degree of noise/smoothing, with AW3D producing the best representation. Slope-area plots display similarly positioned slope-break knickpoints with modest differences in steepness and concavity indices, but again best represented by AW3D. Collectively, our study shows that despite the higher effective resolution of TanDEM-X (12 m), the AW3D (30 m) data performs strongly across all analyses suggesting that it currently offers the greatest potential for regional mountain geomorphological analyses.

ArcticDEM Validation and Accuracy Assessment

NASA Astrophysics Data System (ADS)

Candela, S. G.; Howat, I.; Noh, M. J.; Porter, C. C.; Morin, P. J.

2017-12-01

ArcticDEM comprises a growing inventory Digital Elevation Models (DEMs) covering all land above 60°N. As of August, 2017, ArcticDEM had openly released 2-m resolution, individual DEM covering over 51 million km2, which includes areas of repeat coverage for change detection, as well as over 15 million km2 of 5-m resolution seamless mosaics. By the end of the project, over 80 million km2 of 2-m DEMs will be produced, averaging four repeats of the 20 million km2 Arctic landmass. ArcticDEM is produced from sub-meter resolution, stereoscopic imagery using open source software (SETSM) on the NCSA Blue Waters supercomputer. These DEMs have known biases of several meters due to errors in the sensor models generated from satellite positioning. These systematic errors are removed through three-dimensional registration to high-precision Lidar or other control datasets. ArcticDEM is registered to seasonally-subsetted ICESat elevations due its global coverage and high report accuracy ( 10 cm). The vertical accuracy of ArcticDEM is then obtained from the statistics of the fit to the ICESat point cloud, which averages -0.01 m ± 0.07 m. ICESat, however, has a relatively coarse measurement footprint ( 70 m) which may impact the precision of the registration. Further, the ICESat data predates the ArcticDEM imagery by a decade, so that temporal changes in the surface may also impact the registration. Finally, biases may exist between different the different sensors in the ArcticDEM constellation. Here we assess the accuracy of ArcticDEM and the ICESat registration through comparison to multiple high-resolution airborne lidar datasets that were acquired within one year of the imagery used in ArcticDEM. We find the ICESat dataset is performing as anticipated, introducing no systematic bias during the coregistration process, and reducing vertical errors to within the uncertainty of the airborne Lidars. Preliminary sensor comparisons show no significant difference post coregistration, suggesting that there is no sensor bias between platforms, and all data is suitable for analysis without further correction. Here we will present accuracy assessments, observations and comparisons over diverse terrain in parts of Alaska and Greenland.

DEM generation from contours and a low-resolution DEM

NASA Astrophysics Data System (ADS)

Li, Xinghua; Shen, Huanfeng; Feng, Ruitao; Li, Jie; Zhang, Liangpei

2017-12-01

A digital elevation model (DEM) is a virtual representation of topography, where the terrain is established by the three-dimensional co-ordinates. In the framework of sparse representation, this paper investigates DEM generation from contours. Since contours are usually sparsely distributed and closely related in space, sparse spatial regularization (SSR) is enforced on them. In order to make up for the lack of spatial information, another lower spatial resolution DEM from the same geographical area is introduced. In this way, the sparse representation implements the spatial constraints in the contours and extracts the complementary information from the auxiliary DEM. Furthermore, the proposed method integrates the advantage of the unbiased estimation of kriging. For brevity, the proposed method is called the kriging and sparse spatial regularization (KSSR) method. The performance of the proposed KSSR method is demonstrated by experiments in Shuttle Radar Topography Mission (SRTM) 30 m DEM and Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) 30 m global digital elevation model (GDEM) generation from the corresponding contours and a 90 m DEM. The experiments confirm that the proposed KSSR method outperforms the traditional kriging and SSR methods, and it can be successfully used for DEM generation from contours.

TanDEM-X calibrated Raw DEM generation

NASA Astrophysics Data System (ADS)

Rossi, Cristian; Rodriguez Gonzalez, Fernando; Fritz, Thomas; Yague-Martinez, Nestor; Eineder, Michael

2012-09-01

The TanDEM-X mission successfully started on June 21st 2010 with the launch of the German radar satellite TDX, placed in orbit in close formation with the TerraSAR-X (TSX) satellite, and establishing the first spaceborne bistatic interferometer. The processing of SAR raw data to the Raw DEM is performed by one single processor, the Integrated TanDEM-X Processor (ITP). The quality of the Raw DEM is a fundamental parameter for the mission planning. In this paper, a novel quality indicator is derived. It is based on the comparison of the interferometric measure, the unwrapped phase, and the stereo-radargrammetric measure, the geometrical shifts computed in the coregistration stage. By stating the accuracy of the unwrapped phase, it constitutes a useful parameter for the determination of problematic scenes, which will be resubmitted to the dual baseline phase unwrapping processing chain for the mitigation of phase unwrapping errors. The stereo-radargrammetric measure is also operationally used for the Raw DEM absolute calibration through an accurate estimation of the absolute phase offset. This paper examines the interferometric algorithms implemented for the operational TanDEM-X Raw DEM generation, focusing particularly on its quality assessment and its calibration.

Evaluating DEM conditioning techniques, elevation source data, and grid resolution for field-scale hydrological parameter extraction

NASA Astrophysics Data System (ADS)

Woodrow, Kathryn; Lindsay, John B.; Berg, Aaron A.

2016-09-01

Although digital elevation models (DEMs) prove useful for a number of hydrological applications, they are often the end result of numerous processing steps that each contains uncertainty. These uncertainties have the potential to greatly influence DEM quality and to further propagate to DEM-derived attributes including derived surface and near-surface drainage patterns. This research examines the impacts of DEM grid resolution, elevation source data, and conditioning techniques on the spatial and statistical distribution of field-scale hydrological attributes for a 12,000 ha watershed of an agricultural area within southwestern Ontario, Canada. Three conditioning techniques, including depression filling (DF), depression breaching (DB), and stream burning (SB), were examined. The catchments draining to each boundary of 7933 agricultural fields were delineated using the surface drainage patterns modeled from LiDAR data, interpolated to a 1 m, 5 m, and 10 m resolution DEMs, and from a 10 m resolution photogrammetric DEM. The results showed that variation in DEM grid resolution resulted in significant differences in the spatial and statistical distributions of contributing areas and the distributions of downslope flowpath length. Degrading the grid resolution of the LiDAR data from 1 m to 10 m resulted in a disagreement in mapped contributing areas of between 29.4% and 37.3% of the study area, depending on the DEM conditioning technique. The disagreements among the field-scale contributing areas mapped from the 10 m LiDAR DEM and photogrammetric DEM were large, with nearly half of the study area draining to alternate field boundaries. Differences in derived contributing areas and flowpaths among various conditioning techniques increased substantially at finer grid resolutions, with the largest disagreement among mapped contributing areas occurring between the 1 m resolution DB DEM and the SB DEM (37% disagreement) and the DB-DF comparison (36.5% disagreement in mapped areas). These results demonstrate that the decision to use one DEM conditioning technique over another, and the constraints of available DEM data resolution and source, can greatly impact the modeled surface drainage patterns at the scale of individual fields. This work has significance for applications that attempt to optimize best-management practices (BMPs) for reducing soil erosion and runoff contamination within agricultural watersheds.

Tolerance and resistance characteristics of microalgae Scenedesmus sp. LX1 to methylisothiazolinone.

PubMed

Wang, Xiao-Xiong; Zhang, Tian-Yuan; Dao, Guo-Hua; Hu, Hong-Ying

2018-05-25

Methylisothiazolinone (MIT) has been widely used to control bacterial growth in reverse osmosis (RO) systems. However, MIT's toxicity on microalgae should be determined because residual MIT is concentrated into RO concentrate (ROC) and might have a severe impact on microalgae-based ROC treatment. This study investigated the tolerance of Scenedesmus sp. LX1 to MIT and revealed the mechanism of algal growth inhibition and toxicity resistance. Scenedesmus sp. LX1 was inhibited by MIT with a half-maximal effective concentration at 72 h (72 h-EC 50 ) of 1.00 mg/L, but the strain recovered from the inhibition when its growth was not completely inhibited. It was observed that this inhibition's effect on subsequent growth was weak, and the removal of MIT was the primary reason for the recovery. Properly increasing the initial algal density significantly shortened the adaptation time for accelerated recovery in a MIT-containing culture. Photosynthesis damage by MIT was one of the primary reasons for growth inhibition, but microalgal cell respiration and adenosine triphosphate (ATP) synthesis were not completely inhibited, and the algae were still alive even when growth was completely inhibited, which was notably different from observations made with bacteria and fungi. The algae synthesized more chlorophyll, antioxidant enzymes of superoxide dismutase (SOD) and catalase (CAT), and small molecules, such as reduced glutathione (GSH), to resist MIT poisoning. The microalgae-based process could treat the MIT-containing ROC, since MIT was added for only several hours a week in municipal wastewater reclamation RO processes, and the MIT average concentration was considerably lower than the maximum concentration that algae could tolerate. Copyright © 2018. Published by Elsevier Ltd.

Elevation-Based Sea-Level Rise Vulnerability Assessment of Mindanao, Philippines: are Freely-Available 30-M Dems Good Enough?

NASA Astrophysics Data System (ADS)

Santillan, J. R.; Makinano-Santillan, M.

2017-09-01

We assessed the vertical accuracies and uncertainties of three freely-available global DEMs as inputs to elevation-based sea-level rise vulnerability assessment of Mindanao, Philippines - an area where above average SLR of 14.7 mm/year was recently found. These DEMs are the Shuttle Radar Topography Mission (SRTM) DEM, ASTER Global DEM (GDEM Version 2), and ALOS World 3D-30 (AW3D30). Using 2,076 ground control points, we computed each DEM's vertical accuracies and uncertainties, and from these we determined the smallest increment of sea-level rise (SLRImin) that should be considered when using the DEMs for SLR impact assessment, as well as the Minimum Planning Timeline (TLmin) for an elevation-based SLR assessment. Results of vertical accuracy assessment revealed Root Mean Square Errors of 9.80 m for ASTER GDEM V2, 5.16 m for SRTM DEM, and 4.32 m for AW3D30. Vertical uncertainties in terms of the Linear Error at 95 % Confidence (LE95) were found to be as follows: 19.21 m for ASTER GDEM V2, 10.12 m for SRTM DEM, and 8.47 m for AW3D30. From these, we found that ASTER GDEM2 is suitable to model SLR increments of at least 38.41 m and it will take 2,613 years for the cumulative water level increase of 14.7 mm/year to reach the minimum SLR increment afforded by this DEM. For the SRTM DEM, SLRImin and TLmin were computed as 20.24 m and 1,377 years, respectively. For the AW3D30, SLRImin and TLmin were computed as 16.92 m and 1,151 years, respectively. These results suggest that the readily available global DEMs' suitability for mapping coastal inundations due to SLR in our study area is limited by their low vertical accuracies and high uncertainties. All the three DEMs do not have the necessary accuracy and minimum uncertainties that will make them suitable for mapping inundations of Mindanao at smaller increments of SLR (e.g., SLR ≤ 5 m). Hence, users who apply any of these DEMs for SLR impact assessment at SLRIs lower than the DEM's SLRImin must be cautious in reporting the areas of SLR vulnerable zones. Reporting the inundated areas as a range instead of a singular value for a given SLR scenario can highlight the inherent accuracy and uncertainty of the DEM used in the assessment.

Sensitivity of Particle Size in Discrete Element Method to Particle Gas Method (DEM_PGM) Coupling in Underbody Blast Simulations

DTIC Science & Technology

2016-06-12

Particle Size in Discrete Element Method to Particle Gas Method (DEM_PGM) Coupling in Underbody Blast Simulations Venkatesh Babu, Kumar Kulkarni, Sanjay...buried in soil viz., (1) coupled discrete element & particle gas methods (DEM-PGM) and (2) Arbitrary Lagrangian-Eulerian (ALE), are investigated. The...DEM_PGM and identify the limitations/strengths compared to the ALE method. Discrete Element Method (DEM) can model individual particle directly, and

A combined multi-interferogram algorithm for high resolution DEM reconstruction over deformed regions with TerraSAR-X data

NASA Astrophysics Data System (ADS)

Zhao, Chaoying; Qu, Feifei; Zhang, Qin; Zhu, Wu

2012-10-01

The accuracy of DEM generated with interferometric synthetic aperture radar (InSAR) technique mostly depends on phase unwrapping errors, atmospheric effects, baseline errors and phase noise. The first term is more serious if the high-resolution TerraSAR-X data over urban regions and mountainous regions are applied. In addition, the deformation effect cannot be neglected if the study regions are suffering from surface deformation within the SAR acquisition dates. In this paper, several measures have been taken to generate high resolution DEM over urban regions and mountainous regions with TerraSAR data. The SAR interferometric pairs are divided into two subsets: (a) DEM subsets and (b) deformation subsets. These two interferometric sets serve to generate DEM and deformation, respectively. The external DEM is applied to assist the phase unwrapping with "remove-restore" procedure. The deformation phase is re-scaled and subtracted from each DEM observations. Lastly, the stochastic errors including atmospheric effects and phase noise are suppressed by averaging heights from several interferograms with weights. Six TerraSAR-X data are applied to generate a 6-m-resolution DEM over Xi'an, China using these procedures. Both discrete GPS heights and local high resolution and high precision DEM data are applied to calibrate the DEM generated with our algorithm, and around 4.1 m precision is achieved.

TerraSAR-X/TanDEM-X data for natural hazards research in mountainous regions of Uzbekistan

NASA Astrophysics Data System (ADS)

Semakova, Eleonora; Bühler, Yves

2017-07-01

Accurate and up-to-date digital elevation models (DEMs) are important tools for studying mountain hazards. We considered natural hazards related to glacier retreat, debris flows, and snow avalanches in two study areas of the Western Tien-Shan mountains, Uzbekistan. High-resolution DEMs were generated using single TerraSAR-X/TanDEM-X datasets. The high quality and actuality of the DEMs were proved through a comparison with Shuttle Radar Topography Mission, Advanced Spaceborne Emission and Reflection Radiometer, and Topo DEMs, using Ice, Cloud, and Land Elevation Satellite data as the reference dataset. For the first study area, which had high levels of economic activity, we applied the generated TanDEM-X DEM to an avalanche dynamics simulation using RAMMS software. Verification of the output results showed good agreement with field observations. For the second study area, with a wide spatial distribution of glaciers, we applied the TanDEM-X DEM to an assessment of glacier surface elevation changes. The results can be used to calculate the local mass balance in glacier ablation zones in other areas. Models were applied to estimate the probability of moraine-dammed lake formation and the affected area of a possible debris flow resulting from glacial lake outburst. The natural hazard research methods considered here will minimize costly ground observations in poorly accessible mountains and mitigate the impacts of hazards on the environment of Uzbekistan.

The development of form two mathematics i-Think module (Mi-T2)

NASA Astrophysics Data System (ADS)

Yao, Foo Jing; Abdullah, Mohd Faizal Nizam Lee; Tien, Lee Tien

2017-05-01

This study aims to develop a training module i-THINK Mathematics Form Two (Mi-T2) to increase the higher-order thinking skills of students. The Mi-T2 training module was built based on the Sidek Module Development Model (2001). Constructivist learning theory, cognitive learning theory, i-THINK map and higher order thinking skills were the building blocks of the module development. In this study, researcher determined the validity and reliability of Mi-T2 module. The design being used in this study was descriptive study. To determine the needs of Mi-T2 module, questionnaires and literature review were used to collect data. When the need of the module was determined, the module was built and a pilot study was conducted to test the reliability of the Mi-T2 module. The pilot study was conducted at a secondary school in North Kinta, Perak. A Form Two class was selected to be the sample study through clustered random sampling. The pilot study was conducted for two months and one topic had been studied. The Mi-T2 module was evaluated by five expert panels to determine the content validity of the module. The instruments being used in the study were questionnaires about the necessity of the Mi-T2 module for guidance, questionnaires about the validity of the module and questionnaires concerning the reliability of the module. Statistical analysis was conducted to determine the validity and reliability coefficients of the Mi-T2 module. The content validity of Mi-T2 module was determined by Cohen's Kappa's (1968) agreement coefficient and the reliability of Mi-T2 module was determined by Cronbach Alpha's value scale. The content validity of Mi-T2 module was 0.89 and the Cronbach Alpha's value of Mi-T2 module was 0.911.

DEM generation in cloudy-rainy mountainous area with multi-baseline SAR interferometry

NASA Astrophysics Data System (ADS)

Wu, Hong'an; Zhang, Yonghong; Jiang, Decai; Kang, Yonghui

2018-03-01

Conventional singe baseline InSAR is easily affected by atmospheric artifacts, making it difficult to generate highprecision DEM. To solve this problem, in this paper, a multi-baseline interferometric phase accumulation method with weights fixed by coherence is proposed to generate higher accuracy DEM. The mountainous area in Kunming, Yunnan Province, China is selected as study area, which is characterized by cloudy weather, rugged terrain and dense vegetation. The multi-baseline InSAR experiments are carried out by use of four ALOS-2 PALSAR-2 images. The generated DEM is evaluated by Chinese Digital Products of Fundamental Geographic Information 1:50000 DEM. The results demonstrate that: 1) the proposed method can reduce atmospheric artifacts significantly; 2) the accuracy of InSAR DEM generated by six interferograms satisfies the standard of 1:50000 DEM Level Three and American DTED-1.

Methylisothiazolinone toxicity and inhibition of wound healing and regeneration in planaria.

PubMed

Van Huizen, Alanna V; Tseng, Ai-Sun; Beane, Wendy S

2017-10-01

Methylisothiazolinone (MIT) is a common biocide used in cosmetic and industrial settings. Studies have demonstrated that MIT is a human sensitizer, to the extent that in 2013 MIT was named allergen of the year. Recently, we showed that MIT exposure in Xenopus laevis (the African clawed frog) inhibits wound healing and tail regeneration. However, it is unknown whether MIT affects these processes in other animals. Here, we investigated the effects of MIT exposure in planaria-non-parasitic freshwater flatworms able to regenerate all tissues after injury. Using a common research strain of Dugesia japonica, we determined that intact planarians exposed to 15μM MIT displayed both neuromuscular and epithelial-integrity defects. Furthermore, regenerating (head and tail) fragments exposed to 15μM MIT failed to close wounds or had significantly delayed wound healing. Planarian wounds normally close within 1h after injury. However, most MIT-exposed animals retained open wounds at 24h and subsequently died, and those few animals that were able to undergo delayed wound healing without dying exhibited abnormal regeneration. For instance, head regeneration was severely delayed or inhibited, with anterior structures such as eyes failing to form in newly produced tissues. These data suggest that MIT directly affects both wound healing and regeneration in planarians. Next, we investigated the ability of thiol-containing antioxidants to rescue planarian wound closure during MIT exposure. The data reveal both n-acetyl cysteine and glutathione were each able to fully rescue MIT inhibition of wound healing. Lastly, we established MIT toxicity levels by determining the LC 50 of 5 different planarian species: D. japonica, Schmidtea mediterranea, Girardia tigrina, Girardia dorotocephala, and Phagocata gracilis. Our LC 50 data revealed that concentrations as low as 39μM (4.5ppm) are lethal to planarians, with concentrations of just 5μM inhibiting wound healing, and suggest that phylogeny is predictive of species toxicity levels. Together these results indicate MIT may have broad wound healing effects on aquatic species in general and are not limited to X. laevis alone. Future studies should investigate the impact of MIT on wound healing in other organisms, including non-aquatic organisms and mammals. Copyright © 2017 Elsevier B.V. All rights reserved.

Mit1 Transcription Factor Mediates Methanol Signaling and Regulates the Alcohol Oxidase 1 (AOX1) Promoter in Pichia pastoris.

PubMed

Wang, Xiaolong; Wang, Qi; Wang, Jinjia; Bai, Peng; Shi, Lei; Shen, Wei; Zhou, Mian; Zhou, Xiangshan; Zhang, Yuanxing; Cai, Menghao

2016-03-18

The alcohol oxidase 1 (AOX1) promoter (P AOX1) of Pichia pastoris is the most powerful and commonly used promoter for driving protein expression. However, mechanisms regulating its transcriptional activity are unclear. Here, we identified a Zn(II)2Cys6-type methanol-induced transcription factor 1 (Mit1) and elucidated its roles in regulating PAOX1 activity in response to glycerol and methanol. Mit1 regulated the expression of many genes involved in methanol utilization pathway, including AOX1, but did not participate in peroxisome proliferation and transportation of peroxisomal proteins during methanol metabolism. Structural analysis of Mit1 by performing domain deletions confirmed its specific and critical role in the strict repression of P AOX1 in glycerol medium. Importantly, Mit1, Mxr1, and Prm1, which positively regulated P AOX1 in response to methanol, were bound to P AOX1 at different sites and did not interact with each other. However, these factors cooperatively activated P AOX1 through a cascade. Mxr1 mainly functioned during carbon derepression, whereas Mit1 and Prm1 functioned during methanol induction, with Prm1 transmitting methanol signal to Mit1 by binding to the MIT1 promoter (P MIT1), thus increasingly expressing Mit1 and subsequently activating P AOX1. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Insight into the adsorption profiles of the Saprolegnia monoica chitin synthase MIT domain on POPA and POPC membranes by molecular dynamics simulation studies.

PubMed

Kuang, Guanglin; Liang, Lijun; Brown, Christian; Wang, Qi; Bulone, Vincent; Tu, Yaoquan

2016-02-21

The critical role of chitin synthases in oomycete hyphal tip growth has been established. A microtubule interacting and trafficking (MIT) domain was discovered in the chitin synthases of the oomycete model organism, Saprolegnia monoica. MIT domains have been identified in diverse proteins and may play a role in intracellular trafficking. The structure of the Saprolegnia monoica chitin synthase 1 (SmChs1) MIT domain has been recently determined by our group. However, although our in vitro assay identified increased strength in interactions between the MIT domain and phosphatidic acid (PA) relative to other phospholipids including phosphatidylcholine (PC), the mechanism used by the MIT domain remains unknown. In this work, the adsorption behavior of the SmChs1 MIT domain on POPA and POPC membranes was systematically investigated by molecular dynamics simulations. Our results indicate that the MIT domain can adsorb onto the tested membranes in varying orientations. Interestingly, due to the specific interactions between MIT residues and lipid molecules, the binding affinity to the POPA membrane is much higher than that to the POPC membrane. A binding hotspot, which is critical for the adsorption of the MIT domain onto the POPA membrane, was also identified. The lower binding affinity to the POPC membrane can be attributed to the self-saturated membrane surface, which is unfavorable for hydrogen-bond and electrostatic interactions. The present study provides insight into the adsorption profile of SmChs1 and additionally has the potential to improve our understanding of other proteins containing MIT domains.

Deletion of PdMit1, a homolog of yeast Csg1, affects growth and Ca(2+) sensitivity of the fungus Penicillium digitatum, but does not alter virulence.

PubMed

Zhu, Congyi; Wang, Weili; Wang, Mingshuang; Ruan, Ruoxin; Sun, Xuepeng; He, Meixian; Mao, Cungui; Li, Hongye

2015-04-01

GDP-mannose:inositol-phosphorylceramide (MIPC) and its derivatives are important for Ca(2+) sensitization of Saccharomyces cerevisiae and for the virulence of Candida albicans, but its role in the virulence of plant fungal pathogens remains unclear. In this study, we report the identification and functional characterization of PdMit1, the gene encoding MIPC synthase in Penicillium digitatum, one of the most important pathogens of postharvest citrus fruits. To understand the function of PdMit1, a PdMit1 deletion mutant was generated. Compared to its wild-type control, the PdMit1 deletion mutant exhibited slow radial growth, decreased conidia production and delayed conidial germination, suggesting that PdMit1 is important for the growth of mycelium, sporulation and conidial germination. The PdMit1 deletion mutant also showed hypersensitivity to Ca(2+). Treatment with 250 mmol/l Ca(2+) induced vacuole fusion in the wild-type strain, but not in the PdMit1 deletion mutant. Treatment with 250mmol/lCaCl2 upregulated three Ca(2+)-ATPase genes in the wild-type strain, and this was significantly inhibited in the PdMit1 deletion mutant. These results suggest that PdMit1 may have a role in regulating vacuole fusion and expression of Ca(2+)-ATPase genes by controlling biosynthesis of MIPC, and thereby imparts P. digitatum Ca(2+) tolerance. However, we found that PdMit1 is dispensable for virulence of P. digitatum. Copyright © 2015 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Digital elevation model generation from satellite interferometric synthetic aperture radar: Chapter 5

USGS Publications Warehouse

Lu, Zhong; Dzurisin, Daniel; Jung, Hyung-Sup; Zhang, Lei; Lee, Wonjin; Lee, Chang-Wook

2012-01-01

An accurate digital elevation model (DEM) is a critical data set for characterizing the natural landscape, monitoring natural hazards, and georeferencing satellite imagery. The ideal interferometric synthetic aperture radar (InSAR) configuration for DEM production is a single-pass two-antenna system. Repeat-pass single-antenna satellite InSAR imagery, however, also can be used to produce useful DEMs. DEM generation from InSAR is advantageous in remote areas where the photogrammetric approach to DEM generation is hindered by inclement weather conditions. There are many sources of errors in DEM generation from repeat-pass InSAR imagery, for example, inaccurate determination of the InSAR baseline, atmospheric delay anomalies, and possible surface deformation because of tectonic, volcanic, or other sources during the time interval spanned by the images. This chapter presents practical solutions to identify and remove various artifacts in repeat-pass satellite InSAR images to generate a high-quality DEM.

Quality Test Various Existing dem in Indonesia Toward 10 Meter National dem

NASA Astrophysics Data System (ADS)

Amhar, Fahmi

2016-06-01

Indonesia has various DEM from many sources and various acquisition date spreaded in the past two decades. There are DEM from spaceborne system (Radarsat, TerraSAR-X, ALOS, ASTER-GDEM, SRTM), airborne system (IFSAR, Lidar, aerial photos) and also terrestrial one. The research objective is the quality test and how to extract best DEM in particular area. The method is using differential GPS levelling using geodetic GPS equipment on places which is ensured not changed during past 20 years. The result has shown that DEM from TerraSAR-X and SRTM30 have the best quality (rmse 3.1 m and 3.5 m respectively). Based on this research, it was inferred that these parameters are still positively correlated with the basic concept, namely that the lower and the higher the spatial resolution of a DEM data, the more imprecise the resulting vertical height.

The Coordinate Transformation Method of High Resolution dem Data

NASA Astrophysics Data System (ADS)

Yan, Chaode; Guo, Wang; Li, Aimin

2018-04-01

Coordinate transformation methods of DEM data can be divided into two categories. One reconstruct based on original vector elevation data. The other transforms DEM data blocks by transforming parameters. But the former doesn't work in the absence of original vector data, and the later may cause errors at joint places between adjoining blocks of high resolution DEM data. In view of this problem, a method dealing with high resolution DEM data coordinate transformation is proposed. The method transforms DEM data into discrete vector elevation points, and then adjusts positions of points by bi-linear interpolation respectively. Finally, a TIN is generated by transformed points, and the new DEM data in target coordinate system is reconstructed based on TIN. An algorithm which can find blocks and transform automatically is given in this paper. The method is tested in different terrains and proved to be feasible and valid.

A high resolution InSAR topographic reconstruction research in urban area based on TerraSAR-X data

NASA Astrophysics Data System (ADS)

Qu, Feifei; Qin, Zhang; Zhao, Chaoying; Zhu, Wu

2011-10-01

Aiming at the problems of difficult unwrapping and phase noise in InSAR DEM reconstruction, especially for the high-resolution TerraSAR-X data, this paper improved the height reconstruction algorithm in view of "remove-restore" based on external coarse DEM and multi-interferogram processing, proposed a height calibration method based on CR+GPS data. Several measures have been taken for urban high resolution DEM reconstruction with TerraSAR data. The SAR interferometric pairs with long spatial and short temporal baselines are served for the DEM. The external low resolution and low accuracy DEM is applied for the "remove-restore" concept to ease the phase unwrapping. The stochastic errors including atmospheric effects and phase noise are suppressed by weighted averaging of DEM phases. Six TerraSAR-X data are applied to create the twelve-meter's resolution DEM over Xian, China with the newly-proposed method. The heights in discrete GPS benchmarks are used to calibrate the result, and the RMS of 3.29 meter is achieved by comparing with 1:50000 DEM.

Generation and performance assessment of the global TanDEM-X digital elevation model

NASA Astrophysics Data System (ADS)

Rizzoli, Paola; Martone, Michele; Gonzalez, Carolina; Wecklich, Christopher; Borla Tridon, Daniela; Bräutigam, Benjamin; Bachmann, Markus; Schulze, Daniel; Fritz, Thomas; Huber, Martin; Wessel, Birgit; Krieger, Gerhard; Zink, Manfred; Moreira, Alberto

2017-10-01

The primary objective of the TanDEM-X mission is the generation of a global, consistent, and high-resolution digital elevation model (DEM) with unprecedented global accuracy. The goal is achieved by exploiting the interferometric capabilities of the two twin SAR satellites TerraSAR-X and TanDEM-X, which fly in a close orbit formation, acting as an X-band single-pass interferometer. Between December 2010 and early 2015 all land surfaces have been acquired at least twice, difficult terrain up to seven or eight times. The acquisition strategy, data processing, and DEM calibration and mosaicking have been systematically monitored and optimized throughout the entire mission duration, in order to fulfill the specification. The processing of all data has finally been completed in September 2016 and this paper reports on the final performance of the TanDEM-X global DEM and presents the acquisition and processing strategy which allowed to obtain the final DEM quality. The results confirm the outstanding global accuracy of the delivered product, which can be now utilized for both scientific and commercial applications.

Cross Validation on the Equality of Uav-Based and Contour-Based Dems

NASA Astrophysics Data System (ADS)

Ma, R.; Xu, Z.; Wu, L.; Liu, S.

2018-04-01

Unmanned Aerial Vehicles (UAV) have been widely used for Digital Elevation Model (DEM) generation in geographic applications. This paper proposes a novel framework of generating DEM from UAV images. It starts with the generation of the point clouds by image matching, where the flight control data are used as reference for searching for the corresponding images, leading to a significant time saving. Besides, a set of ground control points (GCP) obtained from field surveying are used to transform the point clouds to the user's coordinate system. Following that, we use a multi-feature based supervised classification method for discriminating non-ground points from ground ones. In the end, we generate DEM by constructing triangular irregular networks and rasterization. The experiments are conducted in the east of Jilin province in China, which has been suffered from soil erosion for several years. The quality of UAV based DEM (UAV-DEM) is compared with that generated from contour interpolation (Contour-DEM). The comparison shows a higher resolution, as well as higher accuracy of UAV-DEMs, which contains more geographic information. In addition, the RMSE errors of the UAV-DEMs generated from point clouds with and without GCPs are ±0.5 m and ±20 m, respectively.

High-Accuracy Tidal Flat Digital Elevation Model Construction Using TanDEM-X Science Phase Data

NASA Technical Reports Server (NTRS)

Lee, Seung-Kuk; Ryu, Joo-Hyung

2017-01-01

This study explored the feasibility of using TanDEM-X (TDX) interferometric observations of tidal flats for digital elevation model (DEM) construction. Our goal was to generate high-precision DEMs in tidal flat areas, because accurate intertidal zone data are essential for monitoring coastal environment sand erosion processes. To monitor dynamic coastal changes caused by waves, currents, and tides, very accurate DEMs with high spatial resolution are required. The bi- and monostatic modes of the TDX interferometer employed during the TDX science phase provided a great opportunity for highly accurate intertidal DEM construction using radar interferometry with no time lag (bistatic mode) or an approximately 10-s temporal baseline (monostatic mode) between the master and slave synthetic aperture radar image acquisitions. In this study, DEM construction in tidal flat areas was first optimized based on the TDX system parameters used in various TDX modes. We successfully generated intertidal zone DEMs with 57-m spatial resolutions and interferometric height accuracies better than 0.15 m for three representative tidal flats on the west coast of the Korean Peninsula. Finally, we validated these TDX DEMs against real-time kinematic-GPS measurements acquired in two tidal flat areas; the correlation coefficient was 0.97 with a root mean square error of 0.20 m.

DDN (Defense Data Network) Protocol Handbook. Volume 3. Supplement

DTIC Science & Technology

1985-12-01

the physical configuration which results from this arrangement, Michael Padlipsky has described this as the " milking machine" approach to computer...NEIRJS-3 74 NETRJS-4 75 77 79 FINGER 81 HOSTS2-NS 83 MIT-ML-DEV 85 MIT-ML-DEV 87 89 SU-MIT-TG 91 MIT-DOV 93 DCP 95 SUPDUP 97 SWIFT- RVF ...PUP QUOTE RDP RJE RLP RTELNET RVD SAT-EXPAK SAT-MON SFTT? SMTP ST SU-MIT-TG SUNRPC SUPDUP SUR-MEAS SWIFT- RVF TACACS-DS TACNEWS

A New DEM Generalization Method Based on Watershed and Tree Structure

PubMed Central

Chen, Yonggang; Ma, Tianwu; Chen, Xiaoyin; Chen, Zhende; Yang, Chunju; Lin, Chenzhi; Shan, Ligang

2016-01-01

The DEM generalization is the basis of multi-dimensional observation, the basis of expressing and analyzing the terrain. DEM is also the core of building the Multi-Scale Geographic Database. Thus, many researchers have studied both the theory and the method of DEM generalization. This paper proposed a new method of generalizing terrain, which extracts feature points based on the tree model construction which considering the nested relationship of watershed characteristics. The paper used the 5 m resolution DEM of the Jiuyuan gully watersheds in the Loess Plateau as the original data and extracted the feature points in every single watershed to reconstruct the DEM. The paper has achieved generalization from 1:10000 DEM to 1:50000 DEM by computing the best threshold. The best threshold is 0.06. In the last part of the paper, the height accuracy of the generalized DEM is analyzed by comparing it with some other classic methods, such as aggregation, resample, and VIP based on the original 1:50000 DEM. The outcome shows that the method performed well. The method can choose the best threshold according to the target generalization scale to decide the density of the feature points in the watershed. Meanwhile, this method can reserve the skeleton of the terrain, which can meet the needs of different levels of generalization. Additionally, through overlapped contour contrast, elevation statistical parameters and slope and aspect analysis, we found out that the W8D algorithm performed well and effectively in terrain representation. PMID:27517296

Towards the optimal fusion of high-resolution Digital Elevation Models for detailed urban flood assessment

NASA Astrophysics Data System (ADS)

Leitão, J. P.; de Sousa, L. M.

2018-06-01

Newly available, more detailed and accurate elevation data sets, such as Digital Elevation Models (DEMs) generated on the basis of imagery from terrestrial LiDAR (Light Detection and Ranging) systems or Unmanned Aerial Vehicles (UAVs), can be used to improve flood-model input data and consequently increase the accuracy of the flood modelling results. This paper presents the first application of the MBlend merging method and assesses the impact of combining different DEMs on flood modelling results. It was demonstrated that different raster merging methods can have different and substantial impacts on these results. In addition to the influence associated with the method used to merge the original DEMs, the magnitude of the impact also depends on (i) the systematic horizontal and vertical differences of the DEMs, and (ii) the orientation between the DEM boundary and the terrain slope. The greater water depth and flow velocity differences between the flood modelling results obtained using the reference DEM and the merged DEMs ranged from -9.845 to 0.002 m, and from 0.003 to 0.024 m s-1 respectively; these differences can have a significant impact on flood hazard estimates. In most of the cases investigated in this study, the differences from the reference DEM results were smaller for the MBlend method than for the results of the two conventional methods. This study highlighted the importance of DEM merging when conducting flood modelling and provided hints on the best DEM merging methods to use.

Accuracy assessment of the global TanDEM-X Digital Elevation Model with GPS data

NASA Astrophysics Data System (ADS)

Wessel, Birgit; Huber, Martin; Wohlfart, Christian; Marschalk, Ursula; Kosmann, Detlev; Roth, Achim

2018-05-01

The primary goal of the German TanDEM-X mission is the generation of a highly accurate and global Digital Elevation Model (DEM) with global accuracies of at least 10 m absolute height error (linear 90% error). The global TanDEM-X DEM acquired with single-pass SAR interferometry was finished in September 2016. This paper provides a unique accuracy assessment of the final TanDEM-X global DEM using two different GPS point reference data sets, which are distributed across all continents, to fully characterize the absolute height error. Firstly, the absolute vertical accuracy is examined by about three million globally distributed kinematic GPS (KGPS) points derived from 19 KGPS tracks covering a total length of about 66,000 km. Secondly, a comparison is performed with more than 23,000 "GPS on Bench Marks" (GPS-on-BM) points provided by the US National Geodetic Survey (NGS) scattered across 14 different land cover types of the US National Land Cover Data base (NLCD). Both GPS comparisons prove an absolute vertical mean error of TanDEM-X DEM smaller than ±0.20 m, a Root Means Square Error (RMSE) smaller than 1.4 m and an excellent absolute 90% linear height error below 2 m. The RMSE values are sensitive to land cover types. For low vegetation the RMSE is ±1.1 m, whereas it is slightly higher for developed areas (±1.4 m) and for forests (±1.8 m). This validation confirms an outstanding absolute height error at 90% confidence level of the global TanDEM-X DEM outperforming the requirement by a factor of five. Due to its extensive and globally distributed reference data sets, this study is of considerable interests for scientific and commercial applications.

Open-Source Digital Elevation Model (DEMs) Evaluation with GPS and LiDAR Data

NASA Astrophysics Data System (ADS)

Khalid, N. F.; Din, A. H. M.; Omar, K. M.; Khanan, M. F. A.; Omar, A. H.; Hamid, A. I. A.; Pa'suya, M. F.

2016-09-01

Advanced Spaceborne Thermal Emission and Reflection Radiometer-Global Digital Elevation Model (ASTER GDEM), Shuttle Radar Topography Mission (SRTM), and Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010) are freely available Digital Elevation Model (DEM) datasets for environmental modeling and studies. The quality of spatial resolution and vertical accuracy of the DEM data source has a great influence particularly on the accuracy specifically for inundation mapping. Most of the coastal inundation risk studies used the publicly available DEM to estimated the coastal inundation and associated damaged especially to human population based on the increment of sea level. In this study, the comparison between ground truth data from Global Positioning System (GPS) observation and DEM is done to evaluate the accuracy of each DEM. The vertical accuracy of SRTM shows better result against ASTER and GMTED10 with an RMSE of 6.054 m. On top of the accuracy, the correlation of DEM is identified with the high determination of coefficient of 0.912 for SRTM. For coastal zone area, DEMs based on airborne light detection and ranging (LiDAR) dataset was used as ground truth data relating to terrain height. In this case, the LiDAR DEM is compared against the new SRTM DEM after applying the scale factor. From the findings, the accuracy of the new DEM model from SRTM can be improved by applying scale factor. The result clearly shows that the value of RMSE exhibit slightly different when it reached 0.503 m. Hence, this new model is the most suitable and meets the accuracy requirement for coastal inundation risk assessment using open source data. The suitability of these datasets for further analysis on coastal management studies is vital to assess the potentially vulnerable areas caused by coastal inundation.

An Interferometric Processing Method to Maintain both Accuracy and Resolution of dem Using GAOFEN-3 SAR Data

NASA Astrophysics Data System (ADS)

Li, T.; Tang, X.; Gao, X.; Chen, Q.; Zhang, X.; Guo, L.

2018-04-01

Gaofen-3 (GF-3) is the only in-orbit SAR satellite of China civilian fields. It is designed especially for ocean observation but not for interferometric applications. However, during the past one and a half years, the orbits of the satellite were adjusted for several times to ensure that the perpendicular baseline is short enough to provide interferograms. In this paper, we used the multi-look iteration algorithm to analyze the DEM obtained from InSAR. We first provide the theory of the method by considering the relationship between multi-look factor and the interferometric phase gradient. Then the GF-3 data as well as TanDEM-X data covering Songshan Mountain are taken for experiments. We use both the GCP data as well as the SRTM DEM for reference. The root-mean-square (RMS) values of TanDEM-X DEM assessed using GCP are 9.4 m, 9.3 m and 8.3 m with reference to ML factors of 8 × 8, 4 × 4 and 2 × 2, respectively. If we assess using SRTM, the corresponding RMS are 1.7 m, 5.4 m and 5.4 m. The result is opposite to that obtained using GCP given that the grid size of SRTM DEM is 90 m. The larger the ML factor, the more similar the calculated DEM to SRTM. RMS of GF-3 DEM compared to GCP is 10.2 m, 13.0 m and 13.8 m with reference to ML factors of 8 × 8, 4 × 4 and 2 × 2, respectively. While that compared to SRTM is 4.6 m, 15.1 m and 23.7 m. The accuracy is low compared to TanDEM-X DEM. Results show that the GF-3 data is potential in providing DEM data. However, the operational applications using GF-3 as interferometric data source would be challenging because of the instability of baseline coherence as well as the temporal coherence.

Feasibility Analysis of DEM Differential Method on Tree Height Assessment wit Terra-SAR/TanDEM-X Data

NASA Astrophysics Data System (ADS)

Zhang, Wangfei; Chen, Erxue; Li, Zengyuan; Feng, Qi; Zhao, Lei

2016-08-01

DEM Differential Method is an effective and efficient way for forest tree height assessment with Polarimetric and interferometric technology, however, the assessment accuracy of it is based on the accuracy of interferometric results and DEM. Terra-SAR/TanDEM-X, which established the first spaceborne bistatic interferometer, can provide highly accurate cross-track interferometric images in the whole global without inherent accuracy limitations like temporal decorrelation and atmospheric disturbance. These characters of Terra-SAR/TandDEM-X give great potential for global or regional tree height assessment, which have been constraint by the temporal decorrelation in traditional repeat-pass interferometry. Currently, in China, it will be costly to collect high accurate DEM with Lidar. At the same time, it is also difficult to get truly representative ground survey samples to test and verify the assessment results. In this paper, we analyzed the feasibility of using TerraSAR/TanDEM-X data to assess forest tree height with current free DEM data like ASTER-GDEM and archived ground in-suit data like forest management inventory data (FMI). At first, the accuracy and of ASTER-GDEM and forest management inventory data had been assessment according to the DEM and canopy height model (CHM) extracted from Lidar data. The results show the average elevation RMSE between ASTER-GEDM and Lidar-DEM is about 13 meters, but they have high correlation with the correlation coefficient of 0.96. With a linear regression model, we can compensate ASTER-GDEM and improve its accuracy nearly to the Lidar-DEM with same scale. The correlation coefficient between FMI and CHM is 0.40. its accuracy is able to be improved by a linear regression model withinconfidence intervals of 95%. After compensation of ASTER-GDEM and FMI, we calculated the tree height in Mengla test site with DEM Differential Method. The results showed that the corrected ASTER-GDEM can effectively improve the assessment accuracy. The average assessment accuracy before and after corrected is 0.73 and 0.76, the RMSE is 5.5 and 4.4, respectively.

Scenario-Based Validation of Moderate Resolution DEMs Freely Available for Complex Himalayan Terrain

NASA Astrophysics Data System (ADS)

Singh, Mritunjay Kumar; Gupta, R. D.; Snehmani; Bhardwaj, Anshuman; Ganju, Ashwagosha

2016-02-01

Accuracy of the Digital Elevation Model (DEM) affects the accuracy of various geoscience and environmental modelling results. This study evaluates accuracies of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) Global DEM Version-2 (GDEM V2), the Shuttle Radar Topography Mission (SRTM) X-band DEM and the NRSC Cartosat-1 DEM V1 (CartoDEM). A high resolution (1 m) photogrammetric DEM (ADS80 DEM), having a high absolute accuracy [1.60 m linear error at 90 % confidence (LE90)], resampled at 30 m cell size was used as reference. The overall root mean square error (RMSE) in vertical accuracy was 23, 73, and 166 m and the LE90 was 36, 75, and 256 m for ASTER GDEM V2, SRTM X-band DEM and CartoDEM, respectively. A detailed error analysis was performed for individual as well as combinations of different classes of aspect, slope, land-cover and elevation zones for the study area. For the ASTER GDEM V2, forest areas with North facing slopes (0°-5°) in the 4th elevation zone (3773-4369 m) showed minimum LE90 of 0.99 m, and barren with East facing slopes (>60°) falling under the 2nd elevation zone (2581-3177 m) showed maximum LE90 of 166 m. For the SRTM DEM, pixels with South-East facing slopes of 0°-5° in the 4th elevation zone covered with forest showed least LE90 of 0.33 m and maximum LE90 of 521 m was observed in the barren area with North-East facing slope (>60°) in the 4th elevation zone. In case of the CartoDEM, the snow pixels in the 2nd elevation zone with South-East facing slopes of 5°-15° showed least LE90 of 0.71 m and maximum LE90 of 1266 m was observed for the snow pixels in the 3rd elevation zone (3177-3773 m) within the South facing slope of 45°-60°. These results can be highly useful for the researchers using DEM products in various modelling exercises.

NASA Chief Technologist on Panel at Massachusetts Institute of Technology

NASA Image and Video Library

2018-02-15

During MIT's "Better MIT Innovation Week 2018," a group of experts discussed innovation as a critical component to and professional accomplishment. From left: Rebecca Chui, founder, RootsStudio; Reinaldo Normand, entrepreneur in residence, MIT; Douglas Terrier, NASA chief technologist; Linda Foster, chief technologist, Lockheed Martin. (Photo: Damian Barabonkov/MIT Technique)

MIT: Shaping the Future.

ERIC Educational Resources Information Center

Manning, Kenneth R., Ed.

This book provides 16 essays by faculty and staff of the Massachusetts Institute of Technology (MIT) concerning what MIT is like today and offering a guide to its possible future. Emphasis is placed on local, national, and global issues, providing a current sampling of the state of concerns and opinions around MIT. Topics include the question of…

Description of the Main Ionospheric Trough by the SM-MIT Model. European Longitudinal Sector

NASA Astrophysics Data System (ADS)

Leshchinskaya, T. Yu.; Pustovalova, L. V.

2018-05-01

Due to the selection of exsisting ionospheric models for incorporation into the created System of Ionospheric Monotoring and Prediction of the Russian Federation, the model of the main ionospheric trough (SM-MIT) is tested with the data from ground-based ionospheric observations in the European longitudinal sector. It is shown that the SM-MIT model does not give an increase in accuracy in comparison to the foF2 monthly median upon a description of the equatorial wall of the MIT. The model describes the foF2 values in the MIT minimum with higher accuracy than the foF2 monthly median or the median IRI model; however, at the same time, the deviations of the model foF2 values from the observed values are high enough: 20-30%. In the MIT minimum, the decrease in the model foF2 values relative to the median values is on average only 10%, which is substantially less than the observed depth of MIT in the evening sector. The verification results have shown that the available SM-MIT model must be completed for practical use.

Evaluation of the MIT RMID 1000 system for the identification of Listeria species.

PubMed

Ricardi, John; Haavig, David; Cruz, Lasaunta; Paoli, George; Gehring, Andrew

2010-01-01

The Micro Imaging Technology (MIT) 1000 Rapid Microbial Identification (RMID) System is a device that uses the principles of light scattering coupled with proprietary algorithms to identify bacteria after being cultured and placed in a vial of filtered water. This specific method is for pure culture identification of Listeria spp. A total of 81 microorganisms (55 isolates) were tested by the MIT 1000 System, of which 25 were Listeria spp. and 30 a variety of other bacterial species. In addition, a total of 406 tests over seven different ruggedness parameters were tested by the MIT 1000 System to determine its flexibility to the specifications stated in the MIT 1000 System User Guide in areas where they might be deviated by a user to shorten the test cycle. Overall, MIT concluded that the MIT 1000 System had an accuracy performance that should certify this Performance Test Method for the identification of Listeria spp. This report discusses the tests performed, results achieved, and conclusions, along with several reference documents to enable a higher understanding of the technology used by the MIT 1000 System.

First-order metal-insulator transition not accompanied by the structural phase transition observed in VO2-based devices

NASA Astrophysics Data System (ADS)

Kim, Hyun-Tak; Chae, Byung-Gyu; Kim, Bong-Jun; Lee, Yong-Wook; Yun, Sun-Jin; Kang, Kwang-Yong

2006-03-01

An abrupt first-order metal-insulator transition (MIT) is observed during the application of a switching pulse voltage to VO2-based two-terminal devices. When the abrupt MIT occurs, the structural phase transition (SPT) is investigated by a micro- Raman spectroscopy and a micro-XRD. The result shows that the MIT is not accompanied with the structural phase transition (SPT); the abrupt MIT is prior to the SPT. Moreover, any switching pulse over a threshold voltage of 7.1 V for the MIT enabled the device material to transform efficiently from an insulator to a metal. The measured delay time from the source switching pulse to an induced MIT pulse is an order of 20 nsec which is much less than a delay time of about one msec deduced by thermal model. This indicates that the first-order MIT does not occur due to thermal. We think this MIT is the Mott transition. (Reference: New J. Phys. 6 (1994) 52 (www.njp.org), Appl. Phys. Lett. 86 (2005) 242101, Physica B 369 (2005. December) xxxx)

Creating Catalytic Collaborations between Theater Artists, Scientists, and Research Institutions

NASA Astrophysics Data System (ADS)

Wise, Debra

2012-02-01

Catalyst Collaborative@MIT (CC@MIT) is a collaboration between MIT and Underground Railway Theater (URT), a company with 30 years experience creating theater through interdisciplinary inquiry and engaging community. CC@MIT is dedicated to creating and presenting plays that deepen public understanding about science, while simultaneously providing artistic and emotional experiences not available in other forms of dialogue about science. CC@MIT engages audiences in thinking about themes in science of social and ethical concern; provides insight into the culture of science and the impact of that culture on society; and examines the human condition through the lens of science that intersects our lives and the lives of scientists. Original productions range from Einstein's Dreams to From Orchids to Octopi -- an evolutionary love story; classics re-framed include The Life of Galileo and Breaking the Code (about Alan Turing). CC@MIT commissions playwrights and scientists to create plays; engages audiences with scientists; performs at MIT and a professional venue near the campus; collaborates with the Cambridge Science Festival and MIT Museum; engages MIT students, as well as youth and children. Artistic Director Debra Wise will address how the collaboration developed, what opportunities are provided by collaborations between theaters and scientific research institutions, and lessons learned of value to the field.

Mit1 Transcription Factor Mediates Methanol Signaling and Regulates the Alcohol Oxidase 1 (AOX1) Promoter in Pichia pastoris*

PubMed Central

Wang, Xiaolong; Wang, Qi; Wang, Jinjia; Bai, Peng; Shi, Lei; Shen, Wei; Zhou, Mian; Zhou, Xiangshan; Zhang, Yuanxing; Cai, Menghao

2016-01-01

The alcohol oxidase 1 (AOX1) promoter (PAOX1) of Pichia pastoris is the most powerful and commonly used promoter for driving protein expression. However, mechanisms regulating its transcriptional activity are unclear. Here, we identified a Zn(II)2Cys6-type methanol-induced transcription factor 1 (Mit1) and elucidated its roles in regulating PAOX1 activity in response to glycerol and methanol. Mit1 regulated the expression of many genes involved in methanol utilization pathway, including AOX1, but did not participate in peroxisome proliferation and transportation of peroxisomal proteins during methanol metabolism. Structural analysis of Mit1 by performing domain deletions confirmed its specific and critical role in the strict repression of PAOX1 in glycerol medium. Importantly, Mit1, Mxr1, and Prm1, which positively regulated PAOX1 in response to methanol, were bound to PAOX1 at different sites and did not interact with each other. However, these factors cooperatively activated PAOX1 through a cascade. Mxr1 mainly functioned during carbon derepression, whereas Mit1 and Prm1 functioned during methanol induction, with Prm1 transmitting methanol signal to Mit1 by binding to the MIT1 promoter (PMIT1), thus increasingly expressing Mit1 and subsequently activating PAOX1. PMID:26828066

Evaluation of lidar-derived DEMs through terrain analysis and field comparison

Treesearch

Cody P. Gillin; Scott W. Bailey; Kevin J. McGuire; Stephen P. Prisley

2015-01-01

Topographic analysis of watershed-scale soil and hydrological processes using digital elevation models (DEMs) is commonplace, but most studies have used DEMs of 10 m resolution or coarser. Availability of higher-resolution DEMs created from light detection and ranging (lidar) data is increasing but their suitability for such applications has received little critical...

The Efficacy and Timing of Melodic Intonation Therapy in Subacute Aphasia.

PubMed

van der Meulen, Ineke; van de Sandt-Koenderman, W Mieke E; Heijenbrok-Kal, Majanka H; Visch-Brink, Evy G; Ribbers, Gerard M

2014-07-01

Background Little is known about the efficacy of language production treatment in subacute severe nonfluent aphasia. Although Melodic Intonation Therapy (MIT) is a language production treatment for this disorder, until now MIT effect studies have focused on chronic aphasia. Purpose This study examines whether language production treatment with MIT is effective in subacute severe nonfluent aphasia. Methods A multicenter, randomized controlled trial was conducted in a waiting-list control design: patients were randomly allocated to the experimental group (MIT) or the control group (control intervention followed by delayed MIT). In both groups, therapy started at 2 to 3 months poststroke and was given intensively (5 h/wk) during 6 weeks. In a second therapy period, the control group received 6 weeks of intensive MIT. The experimental group resumed their regular treatment. Assessment was done at baseline (T1), after the first intervention period (T2), and after the second intervention period (T3). Efficacy was evaluated at T2. The impact of delaying MIT on therapy outcome was also examined. Results A total of 27 participants were included: n = 16 in the experimental group and n = 11 in the control group. A significant effect in favor of MIT on language repetition was observed for trained items, with mixed results for untrained items. After MIT there was a significant improvement in verbal communication but not after the control intervention. Finally, delaying MIT was related to less improvement in the repetition of trained material. Conclusions In these patients with subacute severe nonfluent aphasia, language production treatment with MIT was effective. Earlier treatment may lead to greater improvement. © The Author(s) 2014.

High-resolution linkage map in the proximity of the host resistance locus Cmv1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Depatie, C.; Muise, E.; Gros, P.

1997-01-15

The mouse chromosome 6 locus Cmv1 controls replication of mouse Cytomegalovirus (MCMV) in the spleen of the infected host. In our effort to clone Cmv1, we have constructed a high-resolution genetic linkage map in the proximity of the gene. For this, a total of 45 DNA markers corresponding to either cloned genes or microsatellites were mapped within a 7.9-cM interval overlapping the Cmv1 region. We have followed the cosegregation of these markers with respect to Cmv1 in a total of 2248 backcross mice from a preexisting interspecific backcross panel of 281 (Mus spretus X C57BL/6J)F1 X C57BL/6J and 2 novelmore » panels of 989 (A/J X C57BL6)F1 X A/J and 978 (BALB/c X C57BL/6J)F1 X BALB/c segregating Cmv1. Combined pedigree analysis allowed us to determine the following gene order and intergene distances (in cM) on the distal region of mouse chromosome 6: D6Mit216-(1.9)-D6Mit336-(2.2)-D6Mit218-(1.0)-D6Mit52-(0.5)-D6Mit194-(0.2)-Nkrp1/D6Mit61/135/257/289/338-(0.4)-Cmv1/Ly49A/D6Mit370-(0.3)-Prp/Kap/D6Mit13/111/219-(0.3)-Tel/D6Mit374/290/220/196/195/110-(1.1)-D6Mit25. Therefore, the minimal genetic interval for Cmv1 of 0.7 cM is defined by 13 tightly linked markers including 2 markers, Ly49A and D6Mit370, that did not show recombination with Cmv1 in 1967 meioses analyzed; the proximal limit of the Cmv1 domain was defined by 8 crossovers between Nkrp1/D6Mit61/135/257/289/338 and Cmv1/Ly49A/D6Mit370, and the distal limit was defined by 5 crossovers between Cmv1/Ly49A/D6Mit370 and Prp/Kap/D6Mit13/111/219. This work demonstrates tight linkage between Cmv1 and genes from the natural killer complex (NKC), such as Nkrp1 and Ly49A suggesting that Cmv1 may represent an NK cell recognition structure encoded in the NKC region. 54 refs., 4 figs., 2 tabs.« less

OpenCourseWare Resources for Advanced High School Study

ERIC Educational Resources Information Center

Carson, Steve

2008-01-01

In 2000, the Massachusetts Institute of Technology (MIT) faculty first proposed putting the course materials from all 1,800 MIT classes online, free of charge. The idea behind MIT OpenCourseWare (OCW) was to use the Internet for more than just distance learning. When MIT began placing the course materials online in 2002 and 2003, the audience…

Wrestling with Pedagogical Change: The TEAL Initiative at MIT

ERIC Educational Resources Information Center

Breslow, Lori

2010-01-01

In the late 1990s, the physics department at the Massachusetts Institute of Technology (MIT) had a problem. The department was responsible for teaching the two required physics courses that are part of the General Institute Requirements (GIRs), MIT's core curriculum--Physics I (mechanics, or in MIT parlance, 8.01) and Physics II (electricity and…

How does modifying a DEM to reflect known hydrology affect subsequent terrain analysis?

NASA Astrophysics Data System (ADS)

Callow, John Nikolaus; Van Niel, Kimberly P.; Boggs, Guy S.

2007-01-01

SummaryMany digital elevation models (DEMs) have difficulty replicating hydrological patterns in flat landscapes. Efforts to improve DEM performance in replicating known hydrology have included a variety of soft (i.e. algorithm-based approaches) and hard techniques, such as " Stream burning" or "surface reconditioning" (e.g. Agree or ANUDEM). Using a representation of the known stream network, these methods trench or mathematically warp the original DEM to improve how accurately stream position, stream length and catchment boundaries replicate known hydrological conditions. However, these techniques permanently alter the DEM and may affect further analyses (e.g. slope). This paper explores the impact that commonly used hydrological correction methods ( Stream burning, Agree.aml and ANUDEM v4.6.3 and ANUDEM v5.1) have on the overall nature of a DEM, finding that different methods produce non-convergent outcomes for catchment parameters (such as catchment boundaries, stream position and length), and differentially compromise secondary terrain analysis. All hydrological correction methods successfully improved calculation of catchment area, stream position and length as compared to using the DEM without any modification, but they all increased catchment slope. No single method performing best across all categories. Different hydrological correction methods changed elevation and slope in different spatial patterns and magnitudes, compromising the ability to derive catchment parameters and conduct secondary terrain analysis from a single DEM. Modification of a DEM to better reflect known hydrology can be useful, however knowledge of the magnitude and spatial pattern of the changes are required before using a DEM for subsequent analyses.

Creating high-resolution bare-earth digital elevation models (DEMs) from stereo imagery in an area of densely vegetated deciduous forest using combinations of procedures designed for lidar point cloud filtering

USGS Publications Warehouse

DeWitt, Jessica D.; Warner, Timothy A.; Chirico, Peter G.; Bergstresser, Sarah E.

2017-01-01

For areas of the world that do not have access to lidar, fine-scale digital elevation models (DEMs) can be photogrammetrically created using globally available high-spatial resolution stereo satellite imagery. The resultant DEM is best termed a digital surface model (DSM) because it includes heights of surface features. In densely vegetated conditions, this inclusion can limit its usefulness in applications requiring a bare-earth DEM. This study explores the use of techniques designed for filtering lidar point clouds to mitigate the elevation artifacts caused by above ground features, within the context of a case study of Prince William Forest Park, Virginia, USA. The influences of land cover and leaf-on vs. leaf-off conditions are investigated, and the accuracy of the raw photogrammetric DSM extracted from leaf-on imagery was between that of a lidar bare-earth DEM and the Shuttle Radar Topography Mission DEM. Although the filtered leaf-on photogrammetric DEM retains some artifacts of the vegetation canopy and may not be useful for some applications, filtering procedures significantly improved the accuracy of the modeled terrain. The accuracy of the DSM extracted in leaf-off conditions was comparable in most areas to the lidar bare-earth DEM and filtering procedures resulted in accuracy comparable of that to the lidar DEM.

Generation of a high-accuracy regional DEM based on ALOS/PRISM imagery of East Antarctica

NASA Astrophysics Data System (ADS)

Shiramizu, Kaoru; Doi, Koichiro; Aoyama, Yuichi

2017-12-01

A digital elevation model (DEM) is used to estimate ice-flow velocities for an ice sheet and glaciers via Differential Interferometric Synthetic Aperture Radar (DInSAR) processing. The accuracy of DInSAR-derived displacement estimates depends upon the accuracy of the DEM. Therefore, we used stereo optical images, obtained with a panchromatic remote-sensing instrument for stereo mapping (PRISM) sensor mounted onboard the Advanced Land Observing Satellite (ALOS), to produce a new DEM ("PRISM-DEM") of part of the coastal region of Lützow-Holm Bay in Dronning Maud Land, East Antarctica. We verified the accuracy of the PRISM-DEM by comparing ellipsoidal heights with those of existing DEMs and values obtained by satellite laser altimetry (ICESat/GLAS) and Global Navigation Satellite System surveying. The accuracy of the PRISM-DEM is estimated to be 2.80 m over ice sheet, 4.86 m over individual glaciers, and 6.63 m over rock outcrops. By comparison, the estimated accuracy of the ASTER-GDEM, widely used in polar regions, is 33.45 m over ice sheet, 14.61 m over glaciers, and 19.95 m over rock outcrops. For displacement measurements made along the radar line-of-sight by DInSAR, in conjunction with ALOS/PALSAR data, the accuracy of the PRISM-DEM and ASTER-GDEM correspond to estimation errors of <6.3 mm and <31.8 mm, respectively.

Evaluation of Airborne l- Band Multi-Baseline Pol-Insar for dem Extraction Beneath Forest Canopy

NASA Astrophysics Data System (ADS)

Li, W. M.; Chen, E. X.; Li, Z. Y.; Jiang, C.; Jia, Y.

2018-04-01

DEM beneath forest canopy is difficult to extract with optical stereo pairs, InSAR and Pol-InSAR techniques. Tomographic SAR (TomoSAR) based on different penetration and view angles could reflect vertical structure and ground structure. This paper aims at evaluating the possibility of TomoSAR for underlying DEM extraction. Airborne L-band repeat-pass Pol-InSAR collected in BioSAR 2008 campaign was applied to reconstruct the 3D structure of forest. And sum of kronecker product and algebraic synthesis algorithm were used to extract ground structure, and phase linking algorithm was applied to estimate ground phase. Then Goldstein cut-branch approach was used to unwrap the phases and then estimated underlying DEM. The average difference between the extracted underlying DEM and Lidar DEM is about 3.39 m in our test site. And the result indicates that it is possible for underlying DEM estimation with airborne L-band repeat-pass TomoSAR technique.

Miocene climate as recorded on slope carbonates : examples from Malta (Central Mediterranean) and Northeastern Australia (Marion Plateau, ODP LEG 194)

NASA Astrophysics Data System (ADS)

John, Cédric Michaël

2003-08-01

This study investigated the slope carbonates of two Miocene carbonate systems: the Maltese Islands (in the Central Mediterranean) and the Marion Plateau (Northeastern Australia, drilled during ODP Leg 194). The aim of the study was to trace the impact of the Miocene cooling steps (events Mi1-Mi6) in these carbonate systems, especially the Mi3 event, which took place around 13.6 Ma and deeply impacted the marine oxygen isotope record. This event also profoundly impacted oceanographic and climatic patterns, eventually leading to the establishment of the modern ice-house world. In particular, East Antarctica became ice covered at that period. The rational behind the present study was to investigate the impact that this event had on shallow water systems in order to complement the deep-sea record and hence acquire a more global perspective on Miocene climate change. The Maltese Islands were investigated for trends in bulk-rock carbon and oxygen isotopes, as well as bulk-rock mineralogy, clay minerals analysis and organic geochemisty. Results showed that the mid Miocene cooling event deeply impacted sedimentation at that location by changing sedimentation from carbonate to clay-rich sediments. Moreover, it was discovered that each phase of Antarctic glaciation, not just the major mid Miocene event, resulted in higher terrigenous input on Malta. Mass accumulation rates revealed that this was linked to increased runoff during periods when Antarctica was glaciated, and thus that the carbonate sediments were “diluted” by clay-rich sediments. The model subsequently developed to explain this implies feedback from Antarctic glaciations creating cold, dense air masses that push the ITCZ Northward, thus increasing precipitation on the North African subcontinent. Increased precipitation (or stronger African monsoon) accelerated continental weathering and runoff, thus bringing more terrigenous sediment to the paleo-location of the slope sediments of Malta. Spectral analysis of carbonate content and organic matter geochemical analysis furthermore suggest that the clay-rich intervals are similar to sapropelic deposits. On the Marion Plateau, trends in oxygen and carbon isotopes were obtained by measuring Cibicidoides spp foraminifers. Moreover, carbonate content was reconstructed using a chemical method (coulometer). Results show that the mid Miocene cooling step profoundly affected this system: a major drop in accumulation rates of carbonates occurs precisely at 13.8 Ma, around the time of the East Antarctic ice sheet formation. Moreover, sedimentation changes occurred at that time, carbonate fragments coming from neritic environments becoming less abundant, planktonic foraminifer content increasing and quartz and reworked glauconite being deposited. Conversely, a surprising result is that the major N12-N14 sea-level fall occurring around 11.5 Ma did not impact the accumulation of carbonates on the slope. This was unexpected since carbonate platform are very sensitive to sea-level changes. The model developed to explain that mass accumulation rates of carbonates diminished around 13.6 Ma (Mi3 Event) instead of 11.5 Ma (N12-N14 event), suggests that oceanic currents were controlling slope carbonate deposition on the Marion Plateau prior to the mid-Miocene, and that the mid Miocene event considerably increase their strength, hence reducing the amount of carbonate being deposited on slope sites. Moreover, by combining results from deep-sea oxygen isotopes with sea-level estimates based on coastal onlaps made during Leg 194, we constrain the amplitude of the N12-N14 sea-level fall to 90 meters. When integrating isotopic results from this study, this amplitude is lowered to 70 meters. A general conclusion of this work is that the mid Miocene climatic shift did impact carbonate systems, at least at the two locations studied. However, the nature of this response was highly dependant on the regional settings, in particular the presence of land mass (Malta) and the absence of a barrier to shelter from the effects of open ocean (Marion Plateau). Im Rahmen dieser Doktorarbeit wurden die Hangkarbonate von zwei miozänen heterozoischen Karbonatsystemen näher untersucht: die Malta Inselgruppe (zentrales Mittelmeer) und das Marion Plateau (Nordost Australien, ODP Leg 194). Die Auswirkungen der mittelmiozänen Abkühlung (Mi3), die auf 13.6 Ma datiert wird und starken Einfluß auf die Sauerstoffisotopenkurve hatte, in den oben genannten Flachwassersystemen stellten das Ziel dieser Arbeit dar. Dieses Abkühlungsereignis beeinflußte außerdem sehr stark die ozeanographischen und klimatischen Muster, die im weiteren Verlauf zum modernen Eishausklima führten. So steht insbesondere die Vereisung von Ostantarktika mit diesem Ereignis in Verbindung. Diese Arbeit untersucht den Einfluß dieses Ereignisses auf Flachwassersysteme, um vorliegende Untersuchungen in Tiefwassersystemen zu ergänzen und so zum globalen Verständnis des miozänen Klimawechsels beizutragen. Die Profile auf der Maltainselgruppe wurden mit Hilfe von Kohlenstoff- und Sauerstoffisotopen Auswertungen im Gesamtgestein, Gesamtgesteinmineralogie, Tonmineralanalyse und organischer Geochemie untersucht. Durch einen Wechsel von karbonatischeren zu tonigeren Sedimenten beeinflußte das mittelmiozäne Abkühlungsereignis die Sedimentation in diesem Gebiet sehr stark. Weiterhin wurde beobachtet, daß jede Phase der antarktischen Vereisung, nicht nur das mittelmiozäne Hauptereignis, zu einem erhöhten terrigenen Eintrag in den Hangsedimenten der Maltainselgruppe führte. Akkumulationsraten zeigen, daß dieser erhöhte terrigene Eintrag den einzelnen Vereisungsperioden zusammenhängt und die karbonatischen Sedimente durch tonreiche Sedimente “verunreinigt” wurden. Das daraufhin entwickelte Modell erklärt diesen erhöhten terrigenen Eintrag mit einer nordwärtigen Verlagerung der innertropischen Konvergenzzone durch die Bildung von kalten, dichten Luftmassen, die zu verstärkten Niederschlägen in Nordafrika führten. Diese verstärkten Niederschläge (oder verstärkter afrikanischer Monsun) beeinflußten die kontinentale Verwitterung und den Eintrag, mit der Folge, daß verstärkt terrigene Sedimente im Bereich der Hangsedimente der Maltainselgruppe abgelagert wurden. Die tonreichen Intervalle weisen Ähnlichkeiten zu sapropelischen Ablagerungen auf, was mit Hilfe der Spektral analyse des Karbonatgehalts und der geochemischen Analyse des organischen Materials gezeigt wurde. Auf dem Marion Plateau wurden die Sauerstoff- und Kohlenstoffisotopenkurven anhand von Foraminiferen der Gattung Cibicidoides spp. rekonstruiert. Der Karbonatgehalt wurde mit Hilfe einer chemischen Methode (Coulometer) ermittelt. Genauso wie die Sedimente der Maltainselgruppe beeinflußte das mittelmiozäne Abkühlungsereignis (Mi3) auch die Sedimente auf dem Marion Plateau. So kam es bei 13,8 Ma, in etwa zur Zeit der Vereisung von Ostantarktika, zu einem Abfall der Karbonatakkumulationsraten. Weiterhin traten Änderungen in der Zusammensetzung der Sedimente auf, so nehmen neritische Karbonatfragmente ab, der planktische Foraminiferengehalt nimmt zu und es wurden verstärkt Quarz und Glaukonit abgelagert. Ein überraschendes Ergebnis ist die Tatsache, daß der große N12-N14 Meeresspiegelabfall um 11,5 Ma die Akkumulationsraten der Karbonate auf dem Hang nicht beeinflußte. Dieses Ergebnis ist umso erstaunlicher, da Karbonatplattformen normalerweise sehr sensitiv auf Meeresspiegeländerungen reagieren. Der Grund, warum sich die Karbonatakkumulationsraten schon um 13,6 Ma (Mi3) und nicht erst um 11,5 Ma (N12-N14) verringerten, liegt in der Tatsache, daß die ozeanischen Strömungen die Karbonatsedimentation auf dem Hang des Marion Plateau schon im Miozän kontrollierten. Das mittelmiozäne Ereignis (Mi3) erhöhte die Stärke diese Strömungen und als eine Ursache wurde die Karbonatakkumulation auf den Hängen reduziert. Die Amplitude des N12-N14 Meeresspiegelabfalls liegt bei 90 m unter der Berücksichtigung der Sauerstoffisotopendaten aus der Tiefsee und Berechnungen des Meeresspiegels anhand des “coastal onlaps”, die während Leg 194 gemacht wurden. Die Isotopendaten dieser Arbeit weisen hingegen auf einen verringerten Meeresspiegelabfall von 70 m hin. Als allgemeine Schlußfolgerung kann gesagt werden, daß der mittelmiozäne Klimaumschwung die Karbonatsysteme zumindest an den beiden untersuchten Lokalitäten beeinflußt hat. Allerdings waren die Auswirkungen sehr von den unterschiedlichen lokalen Gegebenheiten abhängig. Insbesondere wirkten sich die Anwesenheit einer Landmasse (Malta) und die Abwesenheit einer Barriere vor den Einflüssen des offenen Ozeans (Marion Plateau) stark auf die Ablagerung der Karbonate aus.

Assessment of Required Accuracy of Digital Elevation Data for Hydrologic Modeling

NASA Technical Reports Server (NTRS)

Kenward, T.; Lettenmaier, D. P.

1997-01-01

The effect of vertical accuracy of Digital Elevation Models (DEMs) on hydrologic models is evaluated by comparing three DEMs and resulting hydrologic model predictions applied to a 7.2 sq km USDA - ARS watershed at Mahantango Creek, PA. The high resolution (5 m) DEM was resempled to a 30 m resolution using method that constrained the spatial structure of the elevations to be comparable with the USGS and SIR-C DEMs. This resulting 30 m DEM was used as the reference product for subsequent comparisons. Spatial fields of directly derived quantities, such as elevation differences, slope, and contributing area, were compared to the reference product, as were hydrologic model output fields derived using each of the three DEMs at the common 30 m spatial resolution.

Determinants of complete resection of thymoma by minimally invasive and open thymectomy: analysis of an international registry

PubMed Central

Burt, Bryan M.; Yao, Xiaopan; Shrager, Joseph; Antonicelli, Alberto; Padda, Sukhmani; Reiss, Jonathan; Wakelee, Heather; Su, Stacey; Huang, James; Scott, Walter

2017-01-01

INTRODUCTION Minimally invasive thymectomy (MIT) is a surgical approach to thymectomy that has more favorable short-term outcomes than open thymectomy (OT) for myasthenia gravis. When performed for thymoma, the oncologic outcomes of MIT have not been rigorously evaluated. We analyzed determinants of complete (R0) resection among patients undergoing MIT and open thymectomy in a large international database. METHODS The retrospective database of the International Thymic Malignancy Interest Group (ITMIG) was queried. Chi-Square and Wilcoxon rank-sum tests, multivariate logistic regression models, and propensity matching were performed. RESULTS A total of 2514 patients underwent thymectomy for thymoma between 1997 and 2012. 2053 (82%) patients underwent OT, 461 (18%) patients underwent MIT, and the use of MIT increased significantly in recent years. The rate of R0 resection among patients undergoing OT was 86%, and among those undergoing MIT was 94%, respectively (p<0.0001). In propensity matched MIT and OT groups (n=266 each group), however, the rate of R0 resection did not differ significantly (MIT 96%, OT 96%, p=0.7). Multivariate analyses were performed to identify determinants of complete resection. Factors independently associated with R0 resection were geographical region, later time period, less advanced Masaoka stage, total thymectomy, and the absence of radiotherapy. Surgical approach, whether minimally invasive or open, was not associated with completeness of resection. CONCLUSIONS The use of MIT for resection of thymoma is increasing substantially over time, and MIT can achieve similar rates of R0 resection for thymoma as OT. PMID:27566187

Mitochondrial N-formyl peptides induce cardiovascular collapse and sepsis-like syndrome

PubMed Central

McCarthy, Cameron G.; Szasz, Theodora; Goulopoulou, Styliani; Webb, R. Clinton

2015-01-01

Fifty percent of trauma patients who present sepsis-like syndrome do not have bacterial infections. This condition is known as systemic inflammatory response syndrome (SIRS). A unifying factor of SIRS and sepsis is cardiovascular collapse. Trauma and severe blood loss cause the release of endogenous molecules known as damage-associated molecular patterns. Mitochondrial N-formyl peptides (F-MIT) are damage-associated molecular patterns that share similarities with bacterial N-formylated peptides and are potent immune system activators. The goal of this study was to investigate whether F-MIT trigger SIRS, including hypotension and vascular collapse via formyl peptide receptor (FPR) activation. We evaluated cardiovascular parameters in Wistar rats treated with FPR or histamine receptor antagonists and inhibitors of the nitric oxide pathway before and after F-MIT infusion. F-MIT, but not nonformylated peptides or mitochondrial DNA, induced severe hypotension via FPR activation and nitric oxide and histamine release. Moreover, F-MIT infusion induced hyperthermia, blood clotting, and increased vascular permeability. To evaluate the role of leukocytes in F-MIT-induced hypotension, neutrophil, basophil, or mast cells were depleted. Depletion of basophils, but not neutrophils or mast cells, abolished F-MIT-induced hypotension. Rats that underwent hemorrhagic shock increased plasma levels of mitochondrial formylated proteins associated with lung damage and antagonism of FPR ameliorated hemorrhagic shock-induced lung injury. Finally, F-MIT induced vasodilatation in isolated resistance arteries via FPR activation; however, F-MIT impaired endothelium-dependent relaxation in the presence of blood. These data suggest that F-MIT may be the link among trauma, SIRS, and cardiovascular collapse. PMID:25637548

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

PubMed

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.

Distinct Mechanisms of Recognizing Endosomal Sorting Complex Required for Transport III (ESCRT-III) Protein IST1 by Different Microtubule Interacting and Trafficking (MIT) Domains*

PubMed Central

Guo, Emily Z.; Xu, Zhaohui

2015-01-01

The endosomal sorting complex required for transport (ESCRT) machinery is responsible for membrane remodeling in a number of biological processes including multivesicular body biogenesis, cytokinesis, and enveloped virus budding. In mammalian cells, efficient abscission during cytokinesis requires proper function of the ESCRT-III protein IST1, which binds to the microtubule interacting and trafficking (MIT) domains of VPS4, LIP5, and Spartin via its C-terminal MIT-interacting motif (MIM). Here, we studied the molecular interactions between IST1 and the three MIT domain-containing proteins to understand the structural basis that governs pairwise MIT-MIM interaction. Crystal structures of the three molecular complexes revealed that IST1 binds to the MIT domains of VPS4, LIP5, and Spartin using two different mechanisms (MIM1 mode versus MIM3 mode). Structural comparison revealed that structural features in both MIT and MIM contribute to determine the specific binding mechanism. Within the IST1 MIM sequence, two phenylalanine residues were shown to be important in discriminating MIM1 versus MIM3 binding. These observations enabled us to deduce a preliminary binding code, which we applied to provide CHMP2A, a protein that normally only binds the MIT domain in the MIM1 mode, the additional ability to bind the MIT domain of Spartin in the MIM3 mode. PMID:25657007

Spatial Resolution Effect on Forest Road Gradient Calculation and Erosion Modelling

NASA Astrophysics Data System (ADS)

Cao, L.; Elliot, W.

2017-12-01

Road erosion is one of the main sediment sources in a forest watershed and should be properly evaluated. With the help of GIS technology, road topography can be determined and soil loss can be predicted at a watershed scale. As a vector geographical feature, the road gradient should be calculated following road direction rather than hillslope direction. This calculation might be difficult with a coarse (30-m) DEM which only provides the underlying topography information. This study was designed to explore the effect of road segmentation and DEM resolution on the road gradient calculation and erosion prediction at a watershed scale. The Water Erosion Prediction Project (WEPP) model was run on road segments of 9 lengths ranging from 40m to 200m. Road gradient was calculated from three DEM data sets: 1m LiDAR, and 10m and 30m USGS DEMs. The 1m LiDAR DEM calculated gradients were very close to the field observed road gradients, so we assumed the 1m LiDAR DEM predicted the true road gradient. The results revealed that longer road segments skipped detail topographical undulations and resulted in lower road gradients. Coarser DEMs computed steeper road gradients as larger grid cells covered more adjacent areas outside road resulting in larger elevation differences. Field surveyed results also revealed that coarser DEM might result in more gradient deviation in a curved road segment when it passes through a convex or concave slope. As road segment length increased, the gradient difference between three DEMs was reduced. There were no significant differences between road gradients of different segment lengths and DEM resolution when segments were longer than 100m. For long segments, the 10m DEM calculated road gradient was similar to the 1m LiDAR gradient. When evaluating the effects of road segment length, the predicted erosion rate decreased with increasing length when road gradient was less than 3%. In cases where the road gradients exceed 3% and rill erosion dominates, predicted erosion rates exponentially increased with segment length. At the watershed scale, most of the predicted soil loss occurred on segments with gradients ranging from 3% to 9%. Based on the road gradient calculated with the 10-m and 30-m DEMs, soil loss was overestimated when compared to the 1m LiDAR DEM. Both the 10m and 30m DEM result in similar total road soil loss.

High-resolution DEM generation from multiple remote sensing data sources for improved volcanic hazard assessment - a case study from Nevado del Ruiz, Colombia

NASA Astrophysics Data System (ADS)

Deng, Fanghui; Dixon, Timothy H.; Rodgers, Mel; Charbonnier, Sylvain J.; Gallant, Elisabeth A.; Voss, Nicholas; Xie, Surui; Malservisi, Rocco; Ordoñez, Milton; López, Cristian M.

2017-04-01

Eruptions of active volcanoes in the presence of snow and ice can cause dangerous floods, avalanches and lahars, threatening millions of people living close to such volcanoes. Colombia's deadliest volcanic hazard in recorded history was caused by Nevado del Ruiz Volcano. On November 13, 1985, a relatively small eruption triggered enormous lahars, killing over 23,000 people in the city of Armero and 2,000 people in the town of Chinchina. Meltwater from a glacier capping the summit of the volcano was the main contributor to the lahars. From 2010 to present, increased seismicity, surface deformation, ash plumes and gas emissions have been observed at Nevado del Ruiz. The DEM is a key parameter for accurate prediction of the pathways of lava flows, pyroclastic flows, and lahars. While satellite coverage has greatly improved the quality of DEMs around the world, volcanoes remain a challenging target because of extremely rugged terrain with steep slopes and deeply cut valleys. In this study, three types of remote sensing data sources with different spatial scales (satellite radar interferometry, terrestrial radar interferometry (TRI), and structure from motion (SfM)) were combined to generate a high resolution DEM (10 m) of Nevado del Ruiz. 1) Synthetic aperture radar (SAR) images acquired by TSX/TDX satellites were applied to generate DEM covering most of the study area. To reduce the effect of geometric distortion inherited from SAR images, TSX/TDX DEMs from ascending and descending orbits were merged to generate a 10×10 m DEM. 2) TRI is a technique that uses a scanning radar to measure the amplitude and phase of a backscattered microwave signal. It provides a more flexible and reliable way to generate DEMs in steep-slope terrain compared with TSX/TDX satellites. The TRI was mounted at four different locations to image the upper slopes of the volcano. A DEM with 5×5 m resolution was generated by TRI. 3) SfM provides an alternative for shadow zones in both TSX/TDX and TRI images. It is a low-cost and effective method to generate high-quality DEMs in relatively small spatial scales. More than 2000 photos were combined to create a DEM of the deep valley in the shadow zones. DEMs from the above three remote sensing data sources were merged into a final DEM with 10×10 m resolution. The effect of this improved DEM on hazard assessment can be evaluated using numerical flow models.

[R]MIT Research Centre at Delft University of Technology: A Bridge between Research, Education, Society and Profession

ERIC Educational Resources Information Center

Zijlstra, Hielkje

2009-01-01

In 2006, we launched the [R]MIT Research Centre (Modification, Intervention Transformation) at the Faculty of Architecture at Delft University of Technology. [R]MIT was founded to respond to the need for an integrated, multi-disciplinary approach to the transformation of the built environment. [R]MIT aims to bring momentum to the renewal of…

Compliant contact versus rigid contact: A comparison in the context of granular dynamics

NASA Astrophysics Data System (ADS)

Pazouki, Arman; Kwarta, Michał; Williams, Kyle; Likos, William; Serban, Radu; Jayakumar, Paramsothy; Negrut, Dan

2017-10-01

We summarize and numerically compare two approaches for modeling and simulating the dynamics of dry granular matter. The first one, the discrete-element method via penalty (DEM-P), is commonly used in the soft matter physics and geomechanics communities; it can be traced back to the work of Cundall and Strack [P. Cundall, Proc. Symp. ISRM, Nancy, France 1, 129 (1971); P. Cundall and O. Strack, Geotechnique 29, 47 (1979), 10.1680/geot.1979.29.1.47]. The second approach, the discrete-element method via complementarity (DEM-C), considers the grains perfectly rigid and enforces nonpenetration via complementarity conditions; it is commonly used in robotics and computer graphics applications and had two strong promoters in Moreau and Jean [J. J. Moreau, in Nonsmooth Mechanics and Applications, edited by J. J. Moreau and P. D. Panagiotopoulos (Springer, Berlin, 1988), pp. 1-82; J. J. Moreau and M. Jean, Proceedings of the Third Biennial Joint Conference on Engineering Systems and Analysis, Montpellier, France, 1996, pp. 201-208]. The DEM-P and DEM-C are manifestly unlike each other: They use different (i) approaches to model the frictional contact problem, (ii) sets of model parameters to capture the physics of interest, and (iii) classes of numerical methods to solve the differential equations that govern the dynamics of the granular material. Herein, we report numerical results for five experiments: shock wave propagation, cone penetration, direct shear, triaxial loading, and hopper flow, which we use to compare the DEM-P and DEM-C solutions. This exercise helps us reach two conclusions. First, both the DEM-P and DEM-C are predictive, i.e., they predict well the macroscale emergent behavior by capturing the dynamics at the microscale. Second, there are classes of problems for which one of the methods has an advantage. Unlike the DEM-P, the DEM-C cannot capture shock-wave propagation through granular media. However, the DEM-C is proficient at handling arbitrary grain geometries and solves, at large integration step sizes, smaller problems, i.e., containing thousands of elements, very effectively. The DEM-P vs DEM-C comparison is carried out using a public-domain, open-source software package; the models used are available online.

Volcanic activity at Etna volcano, Sicily, Italy between June 2011 and March 2017 studied with TanDEM-X SAR interferometry

NASA Astrophysics Data System (ADS)

Kubanek, J.; Raible, B.; Westerhaus, M.; Heck, B.

2017-12-01

High-resolution and up-to-date topographic data are of high value in volcanology and can be used in a variety of applications such as volcanic flow modeling or hazard assessment. Furthermore, time-series of topographic data can provide valuable insights into the dynamics of an ongoing eruption. Differencing topographic data acquired at different times enables to derive areal coverage of lava, flow volumes, and lava extrusion rates, the most important parameters during ongoing eruptions for estimating hazard potential, yet most difficult to determine. Anyhow, topographic data acquisition and provision is a challenge. Very often, high-resolution data only exists within a small spatial extension, or the available data is already outdated when the final product is provided. This is especially true for very dynamic landscapes, such as volcanoes. The bistatic TanDEM-X radar satellite mission enables for the first time to generate up-to-date and high-resolution digital elevation models (DEMs) repeatedly using the interferometric phase. The repeated acquisition of TanDEM-X data facilitates the generation of a time-series of DEMs. Differencing DEMs generated from bistatic TanDEM-X data over time can contribute to monitor topographic changes at active volcanoes, and can help to estimate magmatic ascent rates. Here, we use the bistatic TanDEM-X data to investigate the activity of Etna volcano in Sicily, Italy. Etna's activity is characterized by lava fountains and lava flows with ash plumes from four major summit crater areas. Especially the newest crater, the New South East Crater (NSEC) that was formed in 2011 has been highly active in recent years. Over one hundred bistatic TanDEM-X data pairs were acquired between January 2011 and March 2017 in StripMap mode, covering episodes of lava fountaining and lava flow emplacement at Etna's NSEC and its surrounding area. Generating DEMs of every bistatic data pair enables us to assess areal extension of the lava flows, to calculate lava flow volume, and lava extrusion rates. TanDEM-X data have been acquired at Etna during almost every overflight of the TanDEM-X satellite mission, resulting in a high-temporal resolution of DEMs giving highly valuable insights into Etna's volcanic activity of the last six years.

Compliant contact versus rigid contact: A comparison in the context of granular dynamics.

PubMed

Pazouki, Arman; Kwarta, Michał; Williams, Kyle; Likos, William; Serban, Radu; Jayakumar, Paramsothy; Negrut, Dan

2017-10-01

We summarize and numerically compare two approaches for modeling and simulating the dynamics of dry granular matter. The first one, the discrete-element method via penalty (DEM-P), is commonly used in the soft matter physics and geomechanics communities; it can be traced back to the work of Cundall and Strack [P. Cundall, Proc. Symp. ISRM, Nancy, France 1, 129 (1971); P. Cundall and O. Strack, Geotechnique 29, 47 (1979)GTNQA80016-850510.1680/geot.1979.29.1.47]. The second approach, the discrete-element method via complementarity (DEM-C), considers the grains perfectly rigid and enforces nonpenetration via complementarity conditions; it is commonly used in robotics and computer graphics applications and had two strong promoters in Moreau and Jean [J. J. Moreau, in Nonsmooth Mechanics and Applications, edited by J. J. Moreau and P. D. Panagiotopoulos (Springer, Berlin, 1988), pp. 1-82; J. J. Moreau and M. Jean, Proceedings of the Third Biennial Joint Conference on Engineering Systems and Analysis, Montpellier, France, 1996, pp. 201-208]. The DEM-P and DEM-C are manifestly unlike each other: They use different (i) approaches to model the frictional contact problem, (ii) sets of model parameters to capture the physics of interest, and (iii) classes of numerical methods to solve the differential equations that govern the dynamics of the granular material. Herein, we report numerical results for five experiments: shock wave propagation, cone penetration, direct shear, triaxial loading, and hopper flow, which we use to compare the DEM-P and DEM-C solutions. This exercise helps us reach two conclusions. First, both the DEM-P and DEM-C are predictive, i.e., they predict well the macroscale emergent behavior by capturing the dynamics at the microscale. Second, there are classes of problems for which one of the methods has an advantage. Unlike the DEM-P, the DEM-C cannot capture shock-wave propagation through granular media. However, the DEM-C is proficient at handling arbitrary grain geometries and solves, at large integration step sizes, smaller problems, i.e., containing thousands of elements, very effectively. The DEM-P vs DEM-C comparison is carried out using a public-domain, open-source software package; the models used are available online.

„3D-augmented-reality“-Visualisierung für die navigierte Osteosynthese von Beckenfrakturen

PubMed Central

Befrui, N.; Fischer, M.; Fuerst, B.; Lee, S.-C.; Fotouhi, J.; Weidert, S.; Johnson, A.; Euler, E.; Osgood, G.; Navab, N.; Böcker, W.

2018-01-01

Zusammenfassung Hintergrund Trotz großer Fortschritte in der Entwicklung der Hard- und Software von Navigationssystemen finden diese aufgrund ihrer vermeintlichen Komplexität, umständlichen Integration in klinische Arbeitsabläufe und fraglichen Vorteilen gegenüber konventionellen bildgebenden Verfahren bisher wenig Einsatz in den heutigen Operationssälen. Ziel der Arbeit Entwicklung einer „Augmented-reality“(AR)-Darstellung zur chirurgischen Navigation ohne Infrarot(„IR“)-Tracking-Marker und Vergleich zum konventioneller Röntgen in einem simulierten Eingriff. Material und Methoden Navigationssystem bestehend aus „Cone-beam-CT“(CBCT)-fähigem C-Bogen und „Red-green-blue-depth“(RGBD)-Kamera. Testung durch Kirschner(K)-Draht-Platzierung in Modellen unter Berücksichtigung der benötigten Zeit, der Strahlendosis und der Benutzerfreundlichkeit der Systeme. Ergebnisse Eine signifikante Reduktion der benötigten Zeit, der Röntgenbilder und der gesamten Strahlendosis bei der AR-Navigation gegenüber dem konventionellen Röntgen bei gleichbleibender Präzision. Schlussfolgerung Die AR-Navigation mithilfe der RGBD-Kamera bietet flexible und intuitive Darstellungsmöglichkeiten des Operations-situs für navigierte Osteosynthesen ohne Tracking-Marker. Hiermit ist es möglich, Operationen schneller, einfacher und mit geringerer Strahlenbelastung für Patient und OP-Personal durchzuführen. PMID:29500506

Ganzheitliche Digitalisierungsansätze im Stadtwerk: Von der Strategie bis zur Umsetzung

NASA Astrophysics Data System (ADS)

Dudenhausen, Roman; Hahn, Heike

Digitalisierung muss im Stadtwerk dazu führen, Kundenerwartungen, die heutzutage schon vielfach durch digitales Know-how und Erfahrungen geprägt sind, in einzigartiger Weise zu entsprechen - in Form digitaler Kundenkontaktpunkte, automatisierter Prozesse oder plattformbasierter Geschäftsmodelle. Eine große Rolle spielen dabei unternehmensweit nutzbare Informationen, die eine 360-Grad-Sicht auf den Kunden ermöglichen. Nur in dieser Kombination werden sich nachhaltig Wettbewerbsvorteile generieren lassen. Manch ein Kunde wird die Lust, einen Prozess zu Ende zu gehen, schon vor dem Abschluss verlieren, wenn er nicht unmittelbar und ohne die digitale Welt zu verlassen zum Ziel kommt. Eine nur "halb digitale Kundenerfahrung" wird weder zu Neugeschäft noch zur positiven emotionalen Bindung zwischen Kunden und Stadtwerk führen. Nicht zu unterschätzen sind zudem Erwartungen hinsichtlich zukünftiger Geschäftsmodelle, aus denen sich disruptive Bedrohungen für die herkömmlichen Strom- und Gasangebote ergeben werden. Erste innovative Ansätze finden sich bereits im Markt, die erahnen lassen, dass zurzeit viel diskutierte Technologien wie die Blockchain nicht mehr nur hypothetischer Natur sind. Die Auseinandersetzung mit der Digitalisierung erfolgt dabei sinnvollerweise in einem unternehmensweit abgestimmten Rahmen, der eine zielgerichtete und ganzheitliche Vorgehensweise ermöglicht.

NASA Medical Response to Human Spacecraft Accidents

NASA Technical Reports Server (NTRS)

Patlach, Robert

2011-01-01

This slide presentation reviews NASA's role in the response to spacecraft accidents that involve human fatalities or injuries. Particular attention is given to the work of the Mishap Investigation Team (MIT), the first response to the accidents and the interface to the accident investigation board. The MIT does not investigate the accident, but the objective of the MIT is to gather, guard, preserve and document the evidence. The primary medical objectives of the MIT is to receive, analyze, identify, and transport human remains, provide assistance in the recovery effort, and to provide family Casualty Coordinators with latest recovery information. The MIT while it does not determine the cause of the accident, it acts as the fact gathering arm of the Mishap Investigation Board (MIB), which when it is activated may chose to continue to use the MIT as its field investigation resource. The MIT membership and the specific responsibilities and tasks of the flight surgeon is reviewed. The current law establishing the process is also reviewed.

The rice mitochondrial iron transporter is essential for plant growth

PubMed Central

Bashir, Khurram; Ishimaru, Yasuhiro; Shimo, Hugo; Nagasaka, Seiji; Fujimoto, Masaru; Takanashi, Hideki; Tsutsumi, Nobuhiro; An, Gynheung; Nakanishi, Hiromi; Nishizawa, Naoko K.

2011-01-01

In plants, iron (Fe) is essential for mitochondrial electron transport, heme, and Fe-Sulphur (Fe-S) cluster synthesis; however, plant mitochondrial Fe transporters have not been identified. Here we show, identify and characterize the rice mitochondrial Fe transporter (MIT). Based on a transfer DNA library screen, we identified a rice line showing symptoms of Fe deficiency while accumulating high shoot levels of Fe. Homozygous knockout of MIT in this line resulted in a lethal phenotype. MIT localized to the mitochondria and complemented the growth of Δmrs3Δmrs4 yeast defective in mitochondrial Fe transport. The growth of MIT-knockdown (mit-2) plants was also significantly impaired despite abundant Fe accumulation. Further, the decrease in the activity of the mitochondrial and cytosolic Fe-S enzyme, aconitase, indicated that Fe-S cluster synthesis is affected in mit-2 plants. These results indicate that MIT is a mitochondrial Fe transporter essential for rice growth and development. PMID:21610725

How Strong and Weak Readers Perform on the Developmental Eye Movement Test (DEM): Norms for Latvian School-Aged Children

ERIC Educational Resources Information Center

Serdjukova, Jelena; Ekimane, Lasma; Valeinis, Janis; Skilters, Jurgis; Krumina, Gunta

2017-01-01

The aim of our study was to determine DEM test performance norms for school-aged children in Latvia, assess how DEM test results correlate with children's reading rates, compare test performance between strong and weak readers. A modified DEM test and a newly developed reading test were administered to 1487 children during a screening survey. Our…

High-resolution DEM Effects on Geophysical Flow Models

NASA Astrophysics Data System (ADS)

Williams, M. R.; Bursik, M. I.; Stefanescu, R. E. R.; Patra, A. K.

2014-12-01

Geophysical mass flow models are numerical models that approximate pyroclastic flow events and can be used to assess the volcanic hazards certain areas may face. One such model, TITAN2D, approximates granular-flow physics based on a depth-averaged analytical model using inputs of basal and internal friction, material volume at a coordinate point, and a GIS in the form of a digital elevation model (DEM). The volume of modeled material propagates over the DEM in a way that is governed by the slope and curvature of the DEM surface and the basal and internal friction angles. Results from TITAN2D are highly dependent upon the inputs to the model. Here we focus on a single input: the DEM, which can vary in resolution. High resolution DEMs are advantageous in that they contain more surface details than lower-resolution models, presumably allowing modeled flows to propagate in a way more true to the real surface. However, very high resolution DEMs can create undesirable artifacts in the slope and curvature that corrupt flow calculations. With high-resolution DEMs becoming more widely available and preferable for use, determining the point at which high resolution data is less advantageous compared to lower resolution data becomes important. We find that in cases of high resolution, integer-valued DEMs, very high-resolution is detrimental to good model outputs when moderate-to-low (<10-15°) slope angles are involved. At these slope angles, multiple adjacent DEM cell elevation values are equal due to the need for the DEM to approximate the low slope with a limited set of integer values for elevation. The first derivative of the elevation surface thus becomes zero. In these cases, flow propagation is inhibited by these spurious zero-slope conditions. Here we present evidence for this "terracing effect" from 1) a mathematically defined simulated elevation model, to demonstrate the terracing effects of integer valued data, and 2) a real-world DEM where terracing must be addressed. We discuss the effect on the flow model output and present possible solutions for rectification of the problem.

Comparisons between a high resolution discrete element model and analogue model

NASA Astrophysics Data System (ADS)

LI, C. S.; Yin, H.; WU, C.; Zhang, J.

2017-12-01

A two-dimensional discrete element model (DEM) with high resolution is constructed to simulate the evolution of thrust wedge and an analogue model (AM) experiment is constructed to compare with the DEM results. This efficient parallel DEM program is written in the C language, and it is useful to solve the complex geological problems. More detailed about fold and thrust belts of DEM can be identified with the help of strain field. With non-rotating and non-tensile assumption, dynamic evolution of DEM is highly consistent with AM. Simulations in different scale can compare with each other by conversion formulas in DEM. Our results show that: (1) The overall evolution of DEM and AM is broadly similar. (2) Shortening is accommodated by in-sequence forward propagation of thrusts. The surface slope of the thrust wedge is within the stable field predicted by critical taper theory. (3) Details of thrust spacing, dip angle and number of thrusts vary between DEM and AM for the shortening experiment, but the characteristics of thrusts are similar on the whole. (4) Dip angles of the forward thrusts increased from foreland (ca. 30°) to the mobile wall (ca. 80°) (5) With shortening, both models had not the obvious volume loss. Instead, the volume basic remained unchanged in the whole extrusion processes. (6) Almost all high strain values are within fold-and-thrust belts in DEM, which allows a direct comparison between the fault zone identified on the DEM deformation field and that in the strain field. (7) The first fault initiates at deep depths and propagate down toward the surface. For the maximal volumetric strain focused on the décollement near the mobile wall, strengthening the material and making it for brittle. (8) With non-tensile particles for DEM, contraction is broadly distributed throughout the model and dilation is hardly any, which also leads to a higher efficient computation. (9) High resolution DEM can to first order successfully reproduce structures observed in AM. The comparisons serve to highlight robust features in tectonic modelling of thrust wedges. This approach is very utility in modelling large displacement, complex deformation of analogue and geological materials.

Visual and Statistical Analysis of Digital Elevation Models Generated Using Idw Interpolator with Varying Powers

NASA Astrophysics Data System (ADS)

Asal, F. F.

2012-07-01

Digital elevation data obtained from different Engineering Surveying techniques is utilized in generating Digital Elevation Model (DEM), which is employed in many Engineering and Environmental applications. This data is usually in discrete point format making it necessary to utilize an interpolation approach for the creation of DEM. Quality assessment of the DEM is a vital issue controlling its use in different applications; however this assessment relies heavily on statistical methods with neglecting the visual methods. The research applies visual analysis investigation on DEMs generated using IDW interpolator of varying powers in order to examine their potential in the assessment of the effects of the variation of the IDW power on the quality of the DEMs. Real elevation data has been collected from field using total station instrument in a corrugated terrain. DEMs have been generated from the data at a unified cell size using IDW interpolator with power values ranging from one to ten. Visual analysis has been undertaken using 2D and 3D views of the DEM; in addition, statistical analysis has been performed for assessment of the validity of the visual techniques in doing such analysis. Visual analysis has shown that smoothing of the DEM decreases with the increase in the power value till the power of four; however, increasing the power more than four does not leave noticeable changes on 2D and 3D views of the DEM. The statistical analysis has supported these results where the value of the Standard Deviation (SD) of the DEM has increased with increasing the power. More specifically, changing the power from one to two has produced 36% of the total increase (the increase in SD due to changing the power from one to ten) in SD and changing to the powers of three and four has given 60% and 75% respectively. This refers to decrease in DEM smoothing with the increase in the power of the IDW. The study also has shown that applying visual methods supported by statistical analysis has proven good potential in the DEM quality assessment.

Topogrid Derived 10 Meter Resolution Digital Elevation Model of the Shenandoah National Park and Surrounding Region, Virginia

USGS Publications Warehouse

Chirico, Peter G.; Tanner, Seth D.

2004-01-01

Explanation The purpose of developing a new 10m resolution DEM of the Shenandoah National Park Region was to more accurately depict geologic structure, surfical geology, and landforms of the Shenandoah National Park Region in preparation for automated landform classification. Previously, only a 30m resolution DEM was available through the National Elevation Dataset (NED). During production of the Shenandoah10m DEM of the Park the Geography Discipline of the USGS completed a revised 10m DEM to be included into the NED. However, different methodologies were used to produce the two similar DEMs. The ANUDEM algorithm was used to develop the Shenadoah DEM data. This algorithm allows for the inclusion of contours, streams, rivers, lake and water body polygons as well as spot height data to control the elevation model. A statistical analysis using over 800 National Geodetic Survey (NGS) first and second order vertical control points reveals that the Shenandoah10m DEM, produced as a part of the Appalachian Blue Ridge Landscape project, has a vertical accuracy of ?4.87 meters. The metadata for the 10m NED data reports a vertical accuracy of ?7m. A table listing the NGS control points, the elevation comparison, and the RMSE for the Shenandoah10m DEM is provided. The process of automated terrain classification involves developing statistical signatures from the DEM for each type of surficial deposit and landform type. The signature will be a measure of several characteristics derived from the elevation data including slope, aspect, planform curvature, and profile curvature. The quality of the DEM is of critical importance when extracting terrain signatures. The highest possible horizontal and vertical accuracy is required. The more accurate Shenandoah 10m DEM can now be analyzed and integrated with the geologic observations to yield statistical correlations between the two in the development of landform and surface geology mapping projects.

Diagnosis of Dementia in the Specialist Setting: A Comparison Between the Swedish Dementia Registry (SveDem) and the Registry of Dementias of Girona (ReDeGi)

PubMed Central

Garre-Olmo, Josep; Garcia-Ptacek, Sara; Calvó-Perxas, Laia; Turró-Garriga, Oriol; López-Pousa, Secundino; Eriksdotter, Maria

2016-01-01

The aim of this study was to compare the frequency of dementia diagnoses from two dementia registries in Europe. Patients registered between 2007 and 2013 in the Swedish Dementia Registry (SveDem; Sweden) and in the Registry of Dementias of Girona (ReDeGi; North-East of Spain) were selected. We compared sociodemographic data, Mini-Mental State Examination (MMSE) scores, dementia subtype, and medication consumption of 22,384 cases from SveDem and 5,032 cases from ReDeGi. The average age (78.1 years SveDem versus 79.7 years ReDeGi) and the gender (female 58.2% SveDem versus 61.5% ReDeGi) did not greatly differ. MMSE score at diagnosis was higher for SveDem cases (22.1 versus 17.8). Alzheimer’s disease (AD) accounted for the main dementia subtype (36.6% SveDem versus 55.6% ReDeGi). The proportion of vascular dementia (VaD) and mixed dementia was higher in SveDem (18.8% versus 6.4% and 24.9 versus 13.4%), with an odds ratio (OR) and 95% confidence interval (CI) for SveDem relative to the ReDeGi of 3.41 (3.03–3.84) for VaD, and 2.15 (1.97–2.35) for mixed dementia. This was at the expense of a lower frequency of AD in SveDem (OR 0.41; 95% CI 0.39–0.44). Other dementia diagnoses such as frontotemporal dementia or dementia with Lewy bodies did not significantly differ between registries (2.3% versus 2.9%; 1.9 versus 3.1%). Large differences in medication consumption at the time of dementia diagnosis were detected (4.7 treatments SveDem versus 6.8 ReDeGi). Northern and southern European dementia cohorts differ in demographic characteristics, MMSE score at diagnosis, and drug treatment profile. PMID:27392854

Insight From the Statistics of Nothing: Estimating Limits of Change Detection Using Inferred No-Change Areas in DEM Difference Maps and Application to Landslide Hazard Studies

NASA Astrophysics Data System (ADS)

Haneberg, W. C.

2017-12-01

Remote characterization of new landslides or areas of ongoing movement using differences in high resolution digital elevation models (DEMs) created through time, for example before and after major rains or earthquakes, is an attractive proposition. In the case of large catastrophic landslides, changes may be apparent enough that simple subtraction suffices. In other cases, statistical noise can obscure landslide signatures and place practical limits on detection. In ideal cases on land, GPS surveys of representative areas at the time of DEM creation can quantify the inherent errors. In less-than-ideal terrestrial cases and virtually all submarine cases, it may be impractical or impossible to independently estimate the DEM errors. Examining DEM difference statistics for areas reasonably inferred to have no change, however, can provide insight into the limits of detectability. Data from inferred no-change areas of airborne LiDAR DEM difference maps of the 2014 Oso, Washington landslide and landslide-prone colluvium slopes along the Ohio River valley in northern Kentucky, show that DEM difference maps can have non-zero mean and slope dependent error components consistent with published studies of DEM errors. Statistical thresholds derived from DEM difference error and slope data can help to distinguish between DEM differences that are likely real—and which may indicate landsliding—from those that are likely spurious or irrelevant. This presentation describes and compares two different approaches, one based upon a heuristic assumption about the proportion of the study area likely covered by new landslides and another based upon the amount of change necessary to ensure difference at a specified level of probability.

Assessing uncertainty in SRTM elevations for global flood modelling

NASA Astrophysics Data System (ADS)

Hawker, L. P.; Rougier, J.; Neal, J. C.; Bates, P. D.

2017-12-01

The SRTM DEM is widely used as the topography input to flood models in data-sparse locations. Understanding spatial error in the SRTM product is crucial in constraining uncertainty about elevations and assessing the impact of these upon flood prediction. Assessment of SRTM error was carried out by Rodriguez et al (2006), but this did not explicitly quantify the spatial structure of vertical errors in the DEM, and nor did it distinguish between errors over different types of landscape. As a result, there is a lack of information about spatial structure of vertical errors of the SRTM in the landscape that matters most to flood models - the floodplain. Therefore, this study attempts this task by comparing SRTM, an error corrected SRTM product (The MERIT DEM of Yamazaki et al., 2017) and near truth LIDAR elevations for 3 deltaic floodplains (Mississippi, Po, Wax Lake) and a large lowland region (the Fens, UK). Using the error covariance function, calculated by comparing SRTM elevations to the near truth LIDAR, perturbations of the 90m SRTM DEM were generated, producing a catalogue of plausible DEMs. This allows modellers to simulate a suite of plausible DEMs at any aggregated block size above native SRTM resolution. Finally, the generated DEM's were input into a hydrodynamic model of the Mekong Delta, built using the LISFLOOD-FP hydrodynamic model, to assess how DEM error affects the hydrodynamics and inundation extent across the domain. The end product of this is an inundation map with the probability of each pixel being flooded based on the catalogue of DEMs. In a world of increasing computer power, but a lack of detailed datasets, this powerful approach can be used throughout natural hazard modelling to understand how errors in the SRTM DEM can impact the hazard assessment.

Extracting Urban Morphology for Atmospheric Modeling from Multispectral and SAR Satellite Imagery

NASA Astrophysics Data System (ADS)

Wittke, S.; Karila, K.; Puttonen, E.; Hellsten, A.; Auvinen, M.; Karjalainen, M.

2017-05-01

This paper presents an approach designed to derive an urban morphology map from satellite data while aiming to minimize the cost of data and user interference. The approach will help to provide updates to the current morphological databases around the world. The proposed urban morphology maps consist of two layers: 1) Digital Elevation Model (DEM) and 2) land cover map. Sentinel-2 data was used to create a land cover map, which was realized through image classification using optical range indices calculated from image data. For the purpose of atmospheric modeling, the most important classes are water and vegetation areas. The rest of the area includes bare soil and built-up areas among others, and they were merged into one class in the end. The classification result was validated with ground truth data collected both from field measurements and aerial imagery. The overall classification accuracy for the three classes is 91 %. TanDEM-X data was processed into two DEMs with different grid sizes using interferometric SAR processing. The resulting DEM has a RMSE of 3.2 meters compared to a high resolution DEM, which was estimated through 20 control points in flat areas. Comparing the derived DEM with the ground truth DEM from airborne LIDAR data, it can be seen that the street canyons, that are of high importance for urban atmospheric modeling are not detectable in the TanDEM-X DEM. However, the derived DEM is suitable for a class of urban atmospheric models. Based on the numerical modeling needs for regional atmospheric pollutant dispersion studies, the generated files enable the extraction of relevant parametrizations, such as Urban Canopy Parameters (UCP).

A Comparative Study of Radar Stereo and Interferometry for DEM Generation

NASA Astrophysics Data System (ADS)

Gelautz, M.; Paillou, P.; Chen, C. W.; Zebker, H. A.

2004-06-01

In this experiment, we derive and compare radar stereo and interferometric elevation models (DEMs) of a study site in Djibouti, East Africa. As test data, we use a Radarsat stereo pair and ERS-2 and Radarsat interferometric data. Comparison of the reconstructed DEMs with a SPOT reference DEM shows that in regions of high coherence the DEMs produced by interferometry are of much better quality than the stereo result. However, the interferometric error histograms also show some pronounced outliers due to decorrelation and phase unwrapping problems on forested mountain slopes. The more robust stereo result is able to capture the general terrain shape, but finer surface details are lost. A fusion experiment demonstrates that merging the stereoscopic and interferometric DEMs by utilizing coherence- derived weights can significantly improve the accuracy of the computed elevation maps.

Topographic representation using DEMs and its applications to active tectonics research

NASA Astrophysics Data System (ADS)

Oguchi, T.; Lin, Z.; Hayakawa, Y. S.

2016-12-01

Identifying topographic deformations due to active tectonics has been a principal issue in tectonic geomorphology. It provides useful information such as whether a fault has been active during the recent past. Traditionally, field observations, conventional surveying, and visual interpretation of topographic maps, aerial photos, and satellite images were the main methods for such geomorphological investigations. However, recent studies have been utilizing digital elevation models (DEMs) to visualize and quantitatively analyze landforms. There are many advantages to the use of DEMs for research in active tectonics. For example, unlike aerial photos and satellite images, DEMs show ground conditions without vegetation and man-made objects such as buildings, permitting direct representation of tectonically deformed landforms. Recent developments and advances in airborne LiDAR also allow the fast creation of DEMs even in vegetated areas such as forested lands. In addition, DEMs enable flexible topographic visualization based on various digital cartographic and computer-graphic techniques, facilitating identification of particular landforms such as active faults. Further, recent progress in morphometric analyses using DEMs can be employed to quantitatively represent topographic characteristics, and objectively evaluate tectonic deformation and the properties of related landforms. This paper presents a review of DEM applications in tectonic geomorphology, with attention to historical development, recent advances, and future perspectives. Examples are taken mainly from Japan, a typical tectonically active country. The broader contributions of DEM-based active tectonics research to other fields, such as fluvial geomorphology and geochronology, will also be discussed.

Construction of pixel-level resolution DEMs from monocular images by shape and albedo from shading constrained with low-resolution DEM

NASA Astrophysics Data System (ADS)

Wu, Bo; Liu, Wai Chung; Grumpe, Arne; Wöhler, Christian

2018-06-01

Lunar Digital Elevation Model (DEM) is important for lunar successful landing and exploration missions. Lunar DEMs are typically generated by photogrammetry or laser altimetry approaches. Photogrammetric methods require multiple stereo images of the region of interest and it may not be applicable in cases where stereo coverage is not available. In contrast, reflectance based shape reconstruction techniques, such as shape from shading (SfS) and shape and albedo from shading (SAfS), apply monocular images to generate DEMs with pixel-level resolution. We present a novel hierarchical SAfS method that refines a lower-resolution DEM to pixel-level resolution given a monocular image with known light source. We also estimate the corresponding pixel-wise albedo map in the process and based on that to regularize the shape reconstruction with pixel-level resolution based on the low-resolution DEM. In this study, a Lunar-Lambertian reflectance model is applied to estimate the albedo map. Experiments were carried out using monocular images from the Lunar Reconnaissance Orbiter Narrow Angle Camera (LRO NAC), with spatial resolution of 0.5-1.5 m per pixel, constrained by the Selenological and Engineering Explorer and LRO Elevation Model (SLDEM), with spatial resolution of 60 m. The results indicate that local details are well recovered by the proposed algorithm with plausible albedo estimation. The low-frequency topographic consistency depends on the quality of low-resolution DEM and the resolution difference between the image and the low-resolution DEM.

Phylogenetic relationships of the Gomphales based on nuc-25S-rDNA, mit-12S-rDNA, and mit-atp6-DNA combined sequences

Treesearch

Admir J. Giachini; Kentaro Hosaka; Eduardo Nouhra; Joseph Spatafora; James M. Trappe

2010-01-01

Phylogenetic relationships among Geastrales, Gomphales, Hysterangiales, and Phallales were estimated via combined sequences: nuclear large subunit ribosomal DNA (nuc-25S-rDNA), mitochondrial small subunit ribosomal DNA (mit-12S-rDNA), and mitochondrial atp6 DNA (mit-atp6-DNA). Eighty-one taxa comprising 19 genera and 58 species...

Analysis the Accuracy of Digital Elevation Model (DEM) for Flood Modelling on Lowland Area

NASA Astrophysics Data System (ADS)

Zainol Abidin, Ku Hasna Zainurin Ku; Razi, Mohd Adib Mohammad; Bukari, Saifullizan Mohd

2018-04-01

Flood is one type of natural disaster that occurs almost every year in Malaysia. Commonly the lowland areas are the worst affected areas. This kind of disaster is controllable by using an accurate data for proposing any kinds of solutions. Elevation data is one of the data used to produce solutions for flooding. Currently, the research about the application of Digital Elevation Model (DEM) in hydrology was increased where this kind of model will identify the elevation for required areas. University of Tun Hussein Onn Malaysia is one of the lowland areas which facing flood problems on 2006. Therefore, this area was chosen in order to produce DEM which focussed on University Health Centre (PKU) and drainage area around Civil and Environment Faculty (FKAAS). Unmanned Aerial Vehicle used to collect aerial photos data then undergoes a process of generating DEM according to three types of accuracy and quality from Agisoft PhotoScan software. The higher the level of accuracy and quality of DEM produced, the longer time taken to generate a DEM. The reading of the errors created while producing the DEM shows almost 0.01 different. Therefore, it has been identified there are some important parameters which influenced the accuracy of DEM.

Hydrologic enforcement of lidar DEMs

USGS Publications Warehouse

Poppenga, Sandra K.; Worstell, Bruce B.; Danielson, Jeffrey J.; Brock, John C.; Evans, Gayla A.; Heidemann, H. Karl

2014-01-01

Hydrologic-enforcement (hydro-enforcement) of light detection and ranging (lidar)-derived digital elevation models (DEMs) modifies the elevations of artificial impediments (such as road fills or railroad grades) to simulate how man-made drainage structures such as culverts or bridges allow continuous downslope flow. Lidar-derived DEMs contain an extremely high level of topographic detail; thus, hydro-enforced lidar-derived DEMs are essential to the U.S. Geological Survey (USGS) for complex modeling of riverine flow. The USGS Coastal and Marine Geology Program (CMGP) is integrating hydro-enforced lidar-derived DEMs (land elevation) and lidar-derived bathymetry (water depth) to enhance storm surge modeling in vulnerable coastal zones.

A seamless, high-resolution digital elevation model (DEM) of the north-central California coast

USGS Publications Warehouse

Foxgrover, Amy C.; Barnard, Patrick L.

2012-01-01

A seamless, 2-meter resolution digital elevation model (DEM) of the north-central California coast has been created from the most recent high-resolution bathymetric and topographic datasets available. The DEM extends approximately 150 kilometers along the California coastline, from Half Moon Bay north to Bodega Head. Coverage extends inland to an elevation of +20 meters and offshore to at least the 3 nautical mile limit of state waters. This report describes the procedures of DEM construction, details the input data sources, and provides the DEM for download in both ESRI Arc ASCII and GeoTIFF file formats with accompanying metadata.

Optimizing digital elevation models (DEMs) accuracy for planning and design of mobile communication networks

NASA Astrophysics Data System (ADS)

Hassan, Mahmoud A.

2004-02-01

Digital elevation models (DEMs) are important tools in the planning, design and maintenance of mobile communication networks. This research paper proposes a method for generating high accuracy DEMs based on SPOT satellite 1A stereo pair images, ground control points (GCP) and Erdas OrthoBASE Pro image processing software. DEMs with 0.2911 m mean error were achieved for the hilly and heavily populated city of Amman. The generated DEM was used to design a mobile communication network resulted in a minimum number of radio base transceiver stations, maximum number of covered regions and less than 2% of dead zones.

Determinants of Complete Resection of Thymoma by Minimally Invasive and Open Thymectomy: Analysis of an International Registry.

PubMed

Burt, Bryan M; Yao, Xiaopan; Shrager, Joseph; Antonicelli, Alberto; Padda, Sukhmani; Reiss, Jonathan; Wakelee, Heather; Su, Stacey; Huang, James; Scott, Walter

2017-01-01

Minimally invasive thymectomy (MIT) is a surgical approach to thymectomy that has more favorable short-term outcomes for myasthenia gravis than open thymectomy (OT). The oncologic outcomes of MIT performed for thymoma have not been rigorously evaluated. We analyzed determinants of complete (R0) resection among patients undergoing MIT and OT in a large international database. The retrospective database of the International Thymic Malignancy Interest Group was queried. Chi-square and Wilcoxon rank sum tests, multivariate logistic regression models, and propensity matching were performed. A total of 2514 patients underwent thymectomy for thymoma between 1997 and 2012; 2053 of them (82%) underwent OT and 461 (18%) underwent MIT, with the use of MIT increasing significantly in recent years. The rate of R0 resection among patients undergoing OT was 86%, and among those undergoing MIT it was 94% (p < 0.0001). In propensity-matched MIT and OT groups (n = 266 in each group); however, the rate of R0 resection did not differ significantly (96% in both the MIT and OT groups, p = 0.7). Multivariate analyses were performed to identify determinants of R0 resection. Factors independently associated with R0 resection were geographical region, later time period, less advanced Masaoka stage, total thymectomy, and the absence of radiotherapy. Surgical approach, whether minimally invasive or open, was not associated with completeness of resection. The use of MIT for resection of thymoma has been increasing substantially over time, and MIT can achieve rates of R0 resection for thymoma similar to those achieved with OT. Copyright © 2016 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.

Molecular mapping of the tubby (tub) mutation on mouse chromosome 7

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chung, W.K.; Goldberg-Berman, J.; Power-Kehoe, L.

1996-03-01

Using 180 F2 progeny of a C57BL6/J x CAST/Ei tub/+F1 intersubspecific intercross, a map of 28 molecular markers (including eight genes) on chromosome 7 surrounding the tub locus was generated. Using 33 obese F2 progeny, tub was localized approximately 50-52 cM distal to the centromere on mouse chromosome 7 in the interval defined proximally by hemoglobin beta (Hbb), D7Mit38, D7Mit217, D7Mit37, D7Mit96, and D7Mit33 and distally by D7Mit 98. Using 39 obese F2 progeny from a similar intersubspecific intercross, a telomeric boundary of the interval defining tub was defined by D7Mit53; the order centromere-Hbb/tub-D7Mit53/D7Mit328/D7Mit220-parathyroid hormone (Pth)-calcitonin (Calc)-zona pellucida 2 (2p2)more » was established. By combining the data from the two crosses, the most likely gene order on mouse chromosome 7 is centromere-Hbb-tub-Pth-Calc, thus making it likely that the human homolog of tub resides on 11p15, where the gene order HBB-PTH-CALC is conserved. Assignment of the human tubby homolog to 11p15 allows selection and development of polymorphic molecular markers that can be used to examine segregation of a human homolog of tubby in pedigrees segregating for obesity. The gene sulfonylurea receptor was eliminated as a candidate gene for tubby on the basis of its map position, approximately 3.1 {plus_minus} 3.1 cM centromeric of tyrosinase and approximately 14.9 {plus_minus} 4.8 cM centromeric of Hbb. 47 refs., 2 figs., 2 tabs.« less

Ankle muscle strength discriminates fallers from non-fallers

PubMed Central

Cattagni, Thomas; Scaglioni, Gil; Laroche, Davy; Van Hoecke, Jacques; Gremeaux, Vincent; Martin, Alain

2014-01-01

It is well known that center of pressure (CoP) displacement correlates negatively with the maximal isometric torque (MIT) of ankle muscles. This relationship has never been investigated in elderly fallers (EF). The purpose of this study was thus to analyze the relationship between the MIT of ankle muscles and CoP displacement in upright stance in a sample aged between 18 and 90 years old that included EF. The aim was to identify a threshold of torque below which balance is compromised. The MIT of Plantar flexors (PFs) and dorsal flexors (DFs) and CoP were measured in 90 volunteers: 21 healthy young adults (YA) (age: 24.1 ± 5.0), 12 healthy middle-aged adults (MAA) (age: 50.2 ± 4.5), 27 healthy elderly non-fallers (ENF) (age: 75.5 ± 7.0) and 30 EF (age: 78.8 ± 6.7). The MIT of PF and DF were summed to obtain the overall maximal ankle muscle strength. Body weight and height were used to normalize MIT (nMIT) and CoP (nCoP), respectively. nCoP correlated negatively with nMIT. 90% of EF generated an nMIT <3.1 N·m·kg−1, whereas 85% of non-fallers generated an nMIT >3.1 N·m·kg−1. The relationship between nMIT and nCoP implies that ankle muscle weakness contributes to increased postural instability and the risk of falling. We observed that below the threshold of 3.1 N·m·kg−1, postural stability was dramatically diminished and balance was compromised. Our results suggest that measuring ankle torque could be used in routine clinical practice to identify potential fallers. PMID:25566068

Relative Error Evaluation to Typical Open Global dem Datasets in Shanxi Plateau of China

NASA Astrophysics Data System (ADS)

Zhao, S.; Zhang, S.; Cheng, W.

2018-04-01

Produced by radar data or stereo remote sensing image pairs, global DEM datasets are one of the most important types for DEM data. Relative error relates to surface quality created by DEM data, so it relates to geomorphology and hydrologic applications using DEM data. Taking Shanxi Plateau of China as the study area, this research evaluated the relative error to typical open global DEM datasets including Shuttle Radar Terrain Mission (SRTM) data with 1 arc second resolution (SRTM1), SRTM data with 3 arc second resolution (SRTM3), ASTER global DEM data in the second version (GDEM-v2) and ALOS world 3D-30m (AW3D) data. Through process and selection, more than 300,000 ICESat/GLA14 points were used as the GCP data, and the vertical error was computed and compared among four typical global DEM datasets. Then, more than 2,600,000 ICESat/GLA14 point pairs were acquired using the distance threshold between 100 m and 500 m. Meanwhile, the horizontal distance between every point pair was computed, so the relative error was achieved using slope values based on vertical error difference and the horizontal distance of the point pairs. Finally, false slope ratio (FSR) index was computed through analyzing the difference between DEM and ICESat/GLA14 values for every point pair. Both relative error and FSR index were categorically compared for the four DEM datasets under different slope classes. Research results show: Overall, AW3D has the lowest relative error values in mean error, mean absolute error, root mean square error and standard deviation error; then the SRTM1 data, its values are a little higher than AW3D data; the SRTM3 and GDEM-v2 data have the highest relative error values, and the values for the two datasets are similar. Considering different slope conditions, all the four DEM data have better performance in flat areas but worse performance in sloping regions; AW3D has the best performance in all the slope classes, a litter better than SRTM1; with slope increasing, the relative error for the SRTM3 data increases faster than other DEM datasets; so SRTM3 is better than GDEM-v2 in flat regions but worse in sloping regions. As to FSR value, AW3D has the lowest value, 4.37 %; then SRTM1 data, 5.80 %, similar to AW3D data; SRTM3 has higher value, about 8.27 %; GDEM-v2 data has the highest FSR value, about 12.15 %. FSR can represent the performance of correctly creating the earth surface based on DEM data. Hence, AW3D has the best performance, which is approximate to but a little better than SRTM1. The performance of SRTM3 and GDEM-v2 is similar, which is much worse than AW3D and SRTM1, and the performance of GDEM-v2 is the worst of all. Originated from the DEM dataset with 5m resolution, AW3D is regarded as the most precise global DEM datasets up to now, so it may exerts more effect in topographic analysis and geographic research. Through analysis and comparison of the relative error for the four open global DEM datasets, this research will provide reference in open global DEM datasets selection and applications in geosciences and other relevant fields.

Flight Test Results of a Synthetic Vision Elevation Database Integrity Monitor

NASA Technical Reports Server (NTRS)

deHaag, Maarten Uijt; Sayre, Jonathon; Campbell, Jacob; Young, Steve; Gray, Robert

2001-01-01

This paper discusses the flight test results of a real-time Digital Elevation Model (DEM) integrity monitor for Civil Aviation applications. Providing pilots with Synthetic Vision (SV) displays containing terrain information has the potential to improve flight safety by improving situational awareness and thereby reducing the likelihood of Controlled Flight Into Terrain (CFIT). Utilization of DEMs, such as the digital terrain elevation data (DTED), requires a DEM integrity check and timely integrity alerts to the pilots when used for flight-critical terrain-displays, otherwise the DEM may provide hazardous misleading terrain information. The discussed integrity monitor checks the consistency between a terrain elevation profile synthesized from sensor information, and the profile given in the DEM. The synthesized profile is derived from DGPS and radar altimeter measurements. DEMs of various spatial resolutions are used to illustrate the dependency of the integrity monitor s performance on the DEMs spatial resolution. The paper will give a description of proposed integrity algorithms, the flight test setup, and the results of a flight test performed at the Ohio University airport and in the vicinity of Asheville, NC.

Distinct mechanisms of recognizing endosomal sorting complex required for transport III (ESCRT-III) protein IST1 by different microtubule interacting and trafficking (MIT) domains.

PubMed

Guo, Emily Z; Xu, Zhaohui

2015-03-27

The endosomal sorting complex required for transport (ESCRT) machinery is responsible for membrane remodeling in a number of biological processes including multivesicular body biogenesis, cytokinesis, and enveloped virus budding. In mammalian cells, efficient abscission during cytokinesis requires proper function of the ESCRT-III protein IST1, which binds to the microtubule interacting and trafficking (MIT) domains of VPS4, LIP5, and Spartin via its C-terminal MIT-interacting motif (MIM). Here, we studied the molecular interactions between IST1 and the three MIT domain-containing proteins to understand the structural basis that governs pairwise MIT-MIM interaction. Crystal structures of the three molecular complexes revealed that IST1 binds to the MIT domains of VPS4, LIP5, and Spartin using two different mechanisms (MIM1 mode versus MIM3 mode). Structural comparison revealed that structural features in both MIT and MIM contribute to determine the specific binding mechanism. Within the IST1 MIM sequence, two phenylalanine residues were shown to be important in discriminating MIM1 versus MIM3 binding. These observations enabled us to deduce a preliminary binding code, which we applied to provide CHMP2A, a protein that normally only binds the MIT domain in the MIM1 mode, the additional ability to bind the MIT domain of Spartin in the MIM3 mode. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Distinct Mechanisms of Recognizing Endosomal Sorting Complex Required for Transport III (ESCRT-III) Protein IST1 by Different Microtubule Interacting and Trafficking (MIT) Domains

DOE PAGES

Guo, Emily Z.; Xu, Zhaohui

2015-02-05

The endosomal sorting complex required for transport (ESCRT) machinery is responsible for membrane remodeling in a number of biological processes including multivesicular body biogenesis, cytokinesis, and enveloped virus budding. In mammalian cells, efficient abscission during cytokinesis requires proper function of the ESCRT-III protein IST1, which binds to the microtubule interacting and trafficking (MIT) domains of VPS4, LIP5, and Spartin via its C-terminal MIT-interacting motif (MIM). In this paper, we studied the molecular interactions between IST1 and the three MIT domain-containing proteins to understand the structural basis that governs pairwise MIT-MIM interaction. Crystal structures of the three molecular complexes revealed thatmore » IST1 binds to the MIT domains of VPS4, LIP5, and Spartin using two different mechanisms (MIM1 mode versus MIM3 mode). Structural comparison revealed that structural features in both MIT and MIM contribute to determine the specific binding mechanism. Within the IST1 MIM sequence, two phenylalanine residues were shown to be important in discriminating MIM1 versus MIM3 binding. Finally, these observations enabled us to deduce a preliminary binding code, which we applied to provide CHMP2A, a protein that normally only binds the MIT domain in the MIM1 mode, the additional ability to bind the MIT domain of Spartin in the MIM3 mode.« less

Kommunikation mit Mitarbeitern

NASA Astrophysics Data System (ADS)

Spychala, Anne; Fleischmann, Jürgen

Kommunikation ist der Austausch von Nachrichten und Informationen zwischen Mitarbeitern eines Unternehmens (O'Hair et al. 1997). Dieser Austausch kann persönlich, aber z.B. auch per Telefon, E-Mail oder durch Computersysteme erfolgen. In diesem Kapitel betrachten wir die persönliche Kommunikation zwischen Vorgesetzten und Mitarbeitern. Zur persönlichen Kommunikation mit Mitarbeitern zählen sowohl formelle Gespräche mit Mitarbeitern als auch eher informelle Gespräche zwischen Tür und Angel. Die Gespräche können dabei mit einzelnen Mitarbeitern (z.B. jährliches Mitarbeitergespräch) oder mit Gruppen von Mitarbeitern (z.B. regelmäßige Projekt- oder Teambesprechungen) stattfinden.

Unfallaufnahme und Datenerhebung

NASA Astrophysics Data System (ADS)

Brösdorf, Klaus-Dieter; Moser, Andreas; Burg, Jürgen

Unfälle ereignen sich in unterschiedlichen Schweregraden. Man unterscheidet zwischen Unfälle mit nur Sachschaden und in Unfälle mit Personenschaden. Gemäß Statistik [1] machten in Deutschland im Jahr 2005 Unfälle mit Personenschaden (336.619) etwa 15 % der Gesamtanzahl der polizeilich erfassten Unfälle (2.253.992) aus. In den amtlichen Statistiken sind nur polizeilich erfasste Unfälle enthalten. Eine größere Zahl von Unfällen, insbesondere leichtere Unfälle, wird offensichtlich polizeilich nicht gemeldet. Mit den Daten der Versicherungswirtschaft wird die Anzahl der Kfz-Schäden pro Jahr in Deutschland mit 8.673.000 angegeben [2].

Mott transition between a spin-liquid insulator and a metal in three dimensions.

PubMed

Podolsky, Daniel; Paramekanti, Arun; Kim, Yong Baek; Senthil, T

2009-05-08

We study a bandwidth controlled Mott metal-insulator transition (MIT) from a Fermi-liquid metal to a quantum spin-liquid insulator in three dimensions. Using a slave rotor approach including gauge fluctuations, we obtain a continuous MIT and discuss finite temperature crossovers in its vicinity. We show that the specific heat C approximately Tlnln(1/T) at the MIT and that the metallic state near the MIT should exhibit a "conductivity minimum" as a function of temperature. We suggest Na4Ir3O8 as a candidate to test our predictions and compute its electron spectral function at the MIT.

Tracking Topographic Changes from Multitemporal Stereo Images, Application to the Nili Patera Dune Field

NASA Astrophysics Data System (ADS)

Avouac, J.; Ayoub, F.; Bridges, N. T.; Leprince, S.; Lucas, A.

2012-12-01

The High Resolution Imaging Science Experiment (HiRISE) in orbit around Mars provides images with a nominal ground resolution of 25cm. Its agility allows imaging a same scene with stereo view angles thus allowing for for Digital elevation Model (DEM) extraction through stereo-photogrammetry. This dataset thus offers an exceptional opportunity to measure the topography with high precision and track its eventual evolution with time. In this presentation, we will discuss how multi-temporal acquisitions of HiRISE images of the Nili Patera dune field allow tracking ripples migration, assess sand fluxes and dunes activity. We investigated in particular the use of multi-temporal DEMs to monitor the migration and morphologic evolution of the dune field. We present here the methodology used and the various challenges that must be overcome to best exploit the multi-temporal images. Two DEMs were extracted from two stereo images pairs acquired 390 earth days apart in 2010-2011 using SOCET SET photogrammetry software, with a 1m post-spacing and a vertical accuracy of few tens of centimeters. Prior to comparison the DEMs registration, which was not precise enough out of SOCET-SET, was improved by wrapping the second DEM onto the first one using the bedrock only as a support for registration. The vertical registration residual was estimated at around 40cm RMSE and is mostly due to CCD misalignment and uncorrected spacecraft attitudes. Changes of elevation over time are usually determined from DEMs differentiation: provided that DEMs are perfectly registered and sampled on the same grid, this approach readily quantifies erosion and deposition processes. As the dunes have moved horizontally, they are not physically aligned anymore in the DEMs, and their morphologic evolution cannot be recovered easily from differentiating the DEMs. In this particular setting the topographic evolution is best recovered from correlation of the DEMs. We measure that the fastest dunes have migrated by up to 1meter per Earth year as a result of lee front deposition and stoss slope erosion. DEMs differentiation, after correction for horizontal migration, provides and additional information on dune morphology evolution. Some dunes show a vertical growth over the 390 days spanning the 2 DEMs, but we cannot exclude a bias due to the acquisition parameters. Indeed, the images of the two stereo pairs were acquired 22 and 5 days apart, respectively. During that time, the ripples laying on the dune surface have probably migrated. As the DEMs extraction is based on feature tracking and parallax, this difference in DEMs elevation may be only, or in part, due to the ripple migration between the acquisition times that biased the actual dune elevations.

a New High-Resolution Elevation Model of Greenland Derived from Tandem-X

NASA Astrophysics Data System (ADS)

Wessel, B.; Bertram, A.; Gruber, A.; Bemm, S.; Dech, S.

2016-06-01

In this paper we present for the first time the new digital elevation model (DEM) for Greenland produced by the TanDEM-X (TerraSAR add-on for digital elevation measurement) mission. The new, full coverage DEM of Greenland has a resolution of 0.4 arc seconds corresponding to 12 m. It is composed of more than 7.000 interferometric synthetic aperture radar (InSAR) DEM scenes. X-Band SAR penetrates the snow and ice pack by several meters depending on the structures within the snow, the acquisition parameters, and the dielectricity constant of the medium. Hence, the resulting SAR measurements do not represent the surface but the elevation of the mean phase center of the backscattered signal. Special adaptations on the nominal TanDEM-X DEM generation are conducted to maintain these characteristics and not to raise or even deform the DEM to surface reference data. For the block adjustment, only on the outer coastal regions ICESat (Ice, Cloud, and land Elevation Satellite) elevations as ground control points (GCPs) are used where mostly rock and surface scattering predominates. Comparisons with ICESat data and snow facies are performed. In the inner ice and snow pack, the final X-Band InSAR DEM of Greenland lies up to 10 m below the ICESat measurements. At the outer coastal regions it corresponds well with the GCPs. The resulting DEM is outstanding due to its resolution, accuracy and full coverage. It provides a high resolution dataset as basis for research on climate change in the arctic.

Identification of dysregulated long non-coding RNAs/microRNAs/mRNAs in TNM I stage lung adenocarcinoma

PubMed Central

Tian, Ziqiang; Wen, Shiwang; Zhang, Yuefeng; Shi, Xinqiang; Zhu, Yonggang; Xu, Yanzhao; Lv, Huilai; Wang, Guiying

2017-01-01

Lung adenocarcinoma (LUAD) is the primary subtype in lung cancer, which is the leading cause of cancer-related death worldwide. This study aimed to investigate the aberrant expression profiling of long non-coding RNA (lncRNA) in TNM I stage (stage I) LUAD. The lncRNA/mRNA/miRNA expression profiling of stage I LUAD and adjacent non-tumor tissues from 4 patients were measured by RNA-sequencing. Total of 175 differentially expressed lncRNAs (DELs), 1321 differentially expressed mRNAs (DEMs) and 94 differentially expressed microRNAs (DEMIs) were identified in stage I LUAD. DEMI-DEM regulatory network consisted of 544 nodes and 1123 edge; miR-200 family members had high connectivity with DEMs. In DEL-DEM co-expression network, CDKN2B-AS1, FENDRR and LINC00312 had the high connectivity with DEMs, which co-expressed with 105, 63 and 61 DEMs, respectively. DEL-DEMI-DEM network depicted the links among DELs, DEMI and DEMs. Identified DEMs were significantly enriched in cell adhesion molecules, focal adhesion and tight junction of Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways; and enriched in cell adhesion, angiogenesis and regulation of cell proliferation of Gene Ontology biological processes. Quantitative real-time polymerase chain reaction results were generally consistent with our bioinformatics analyses. LINC00312 and FENDRR had diagnostic value for LUAD patients in The Cancer Genome Atlas database. Our study might lay the foundation for illumination of pathogenesis of LUAD and identification of potential therapeutic targets and novel diagnosis biomarkers for LUAD patients. PMID:28881680

Digital Elevation Model from Non-Metric Camera in Uas Compared with LIDAR Technology

NASA Astrophysics Data System (ADS)

Dayamit, O. M.; Pedro, M. F.; Ernesto, R. R.; Fernando, B. L.

2015-08-01

Digital Elevation Model (DEM) data as a representation of surface topography is highly demanded for use in spatial analysis and modelling. Aimed to that issue many methods of acquisition data and process it are developed, from traditional surveying until modern technology like LIDAR. On the other hands, in a past four year the development of Unamend Aerial System (UAS) aimed to Geomatic bring us the possibility to acquire data about surface by non-metric digital camera on board in a short time with good quality for some analysis. Data collectors have attracted tremendous attention on UAS due to possibility of the determination of volume changes over time, monitoring of the breakwaters, hydrological modelling including flood simulation, drainage networks, among others whose support in DEM for proper analysis. The DEM quality is considered as a combination of DEM accuracy and DEM suitability so; this paper is aimed to analyse the quality of the DEM from non-metric digital camera on UAS compared with a DEM from LIDAR corresponding to same geographic space covering 4 km2 in Artemisa province, Cuba. This area is in a frame of urban planning whose need to know the topographic characteristics in order to analyse hydrology behaviour and decide the best place for make roads, building and so on. Base on LIDAR technology is still more accurate method, it offer us a pattern for test DEM from non-metric digital camera on UAS, whose are much more flexible and bring a solution for many applications whose needs DEM of detail.

MIT-Skywalker: On the use of a markerless system.

PubMed

Goncalves, Rogerio S; Hamilton, Taya; Krebs, Hermano I

2017-07-01

This paper describes our efforts to employ the Microsoft Kinect as a low cost vision control system for the MIT-Skywalker, a robotic gait rehabilitation device. The Kinect enables an alternative markerless solution to control the MIT-Skywalker and allows a more user-friendly set-up. A study involving eight healthy subjects and two stroke survivors using the MIT-Skywalker device demonstrates the advantages and challenges of this new proposed approach.

Application of an enhanced discrete element method to oil and gas drilling processes

NASA Astrophysics Data System (ADS)

Ubach, Pere Andreu; Arrufat, Ferran; Ring, Lev; Gandikota, Raju; Zárate, Francisco; Oñate, Eugenio

2016-03-01

The authors present results on the use of the discrete element method (DEM) for the simulation of drilling processes typical in the oil and gas exploration industry. The numerical method uses advanced DEM techniques using a local definition of the DEM parameters and combined FEM-DEM procedures. This paper presents a step-by-step procedure to build a DEM model for analysis of the soil region coupled to a FEM model for discretizing the drilling tool that reproduces the drilling mechanics of a particular drill bit. A parametric study has been performed to determine the model parameters in order to maintain accurate solutions with reduced computational cost.

Numerical Simulation of Ballistic Impact on Particulate Composite Target using Discrete Element Method: 1-D and 2-D Models

NASA Astrophysics Data System (ADS)

Nair, Rajesh P.; Lakshmana Rao, C.

2014-01-01

Ballistic impact (BI) is a study that deals with a projectile hitting a target and observing its effects in terms of deformation and fragmentation of the target. The Discrete Element Method (DEM) is a powerful numerical technique used to model solid and particulate media. Here, an attempt is made to simulate the BI process using DEM. 1-D DEM for BI is developed and depth of penetration (DOP) is obtained. The DOP is compared with results obtained from 2-D DEM. DEM results are found to match empirical results. Effects of strain rate sensitivity of the material response on DOP are also simulated.

Estimating Coastal Digital Elevation Model (DEM) Uncertainty

NASA Astrophysics Data System (ADS)

Amante, C.; Mesick, S.

2017-12-01

Integrated bathymetric-topographic digital elevation models (DEMs) are representations of the Earth's solid surface and are fundamental to the modeling of coastal processes, including tsunami, storm surge, and sea-level rise inundation. Deviations in elevation values from the actual seabed or land surface constitute errors in DEMs, which originate from numerous sources, including: (i) the source elevation measurements (e.g., multibeam sonar, lidar), (ii) the interpolative gridding technique (e.g., spline, kriging) used to estimate elevations in areas unconstrained by source measurements, and (iii) the datum transformation used to convert bathymetric and topographic data to common vertical reference systems. The magnitude and spatial distribution of the errors from these sources are typically unknown, and the lack of knowledge regarding these errors represents the vertical uncertainty in the DEM. The National Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Information (NCEI) has developed DEMs for more than 200 coastal communities. This study presents a methodology developed at NOAA NCEI to derive accompanying uncertainty surfaces that estimate DEM errors at the individual cell-level. The development of high-resolution (1/9th arc-second), integrated bathymetric-topographic DEMs along the southwest coast of Florida serves as the case study for deriving uncertainty surfaces. The estimated uncertainty can then be propagated into the modeling of coastal processes that utilize DEMs. Incorporating the uncertainty produces more reliable modeling results, and in turn, better-informed coastal management decisions.

Fusion of space-borne multi-baseline and multi-frequency interferometric results based on extended Kalman filter to generate high quality DEMs

NASA Astrophysics Data System (ADS)

Zhang, Xiaojie; Zeng, Qiming; Jiao, Jian; Zhang, Jingfa

2016-01-01

Repeat-pass Interferometric Synthetic Aperture Radar (InSAR) is a technique that can be used to generate DEMs. But the accuracy of InSAR is greatly limited by geometrical distortions, atmospheric effect, and decorrelations, particularly in mountainous areas, such as western China where no high quality DEM has so far been accomplished. Since each of InSAR DEMs generated using data of different frequencies and baselines has their own advantages and disadvantages, it is therefore very potential to overcome some of the limitations of InSAR by fusing Multi-baseline and Multi-frequency Interferometric Results (MMIRs). This paper proposed a fusion method based on Extended Kalman Filter (EKF), which takes the InSAR-derived DEMs as states in prediction step and the flattened interferograms as observations in control step to generate the final fused DEM. Before the fusion, detection of layover and shadow regions, low-coherence regions and regions with large height error is carried out because MMIRs in these regions are believed to be unreliable and thereafter are excluded. The whole processing flow is tested with TerraSAR-X and Envisat ASAR datasets. Finally, the fused DEM is validated with ASTER GDEM and national standard DEM of China. The results demonstrate that the proposed method is effective even in low coherence areas.

Effect of external digital elevation model on monitoring of mine subsidence by two-pass differential interferometric synthetic aperture radar

NASA Astrophysics Data System (ADS)

Tao, Qiuxiang; Gao, Tengfei; Liu, Guolin; Wang, Zhiwei

2017-04-01

The external digital elevation model (DEM) error is one of the main factors that affect the accuracy of mine subsidence monitored by two-pass differential interferometric synthetic aperture radar (DInSAR), which has been widely used in monitoring mining-induced subsidence. The theoretical relationship between external DEM error and monitored deformation error is derived based on the principles of interferometric synthetic aperture radar (DInSAR) and two-pass DInSAR. Taking the Dongtan and Yangcun mine areas of Jining as test areas, the difference and accuracy of 1:50000, ASTER GDEM V2, and SRTM DEMs are compared and analyzed. Two interferometric pairs of Advanced Land Observing Satellite Phased Array L-band SAR covering the test areas are processed using two-pass DInSAR with three external DEMs to compare and analyze the effect of three external DEMs on monitored mine subsidence in high- and low-coherence subsidence regions. Moreover, the reliability and accuracy of the three DInSAR-monitored results are compared and verified with leveling-measured subsidence values. Results show that the effect of external DEM on mine subsidence monitored by two-pass DInSAR is not only related to radar look angle, perpendicular baseline, slant range, and external DEM error, but also to the ground resolution of DEM, the magnitude of subsidence, and the coherence of test areas.

Stochastic noise characteristics in matrix inversion tomosynthesis (MITS).

PubMed

Godfrey, Devon J; McAdams, H P; Dobbins, James T Third

2009-05-01

Matrix inversion tomosynthesis (MITS) uses known imaging geometry and linear systems theory to deterministically separate in-plane detail from residual tomographic blur in a set of conventional tomosynthesis ("shift-and-add") planes. A previous investigation explored the effect of scan angle (ANG), number of projections (N), and number of reconstructed planes (NP) on the MITS impulse response and modulation transfer function characteristics, and concluded that ANG = 20 degrees, N = 71, and NP = 69 is the optimal MITS imaging technique for chest imaging on our prototype tomosynthesis system. This article examines the effect of ANG, N, and NP on the MITS exposure-normalized noise power spectra (ENNPS) and seeks to confirm that the imaging parameters selected previously by an analysis of the MITS impulse response also yield reasonable stochastic properties in MITS reconstructed planes. ENNPS curves were generated for experimentally acquired mean-subtracted projection images, conventional tomosynthesis planes, and MITS planes with varying combinations of the parameters ANG, N, and NP. Image data were collected using a prototype tomosynthesis system, with 11.4 cm acrylic placed near the image receptor to produce lung-equivalent beam hardening and scattered radiation. Ten identically acquired tomosynthesis data sets (realizations) were collected for each selected technique and used to generate ensemble mean images that were subtracted from individual image realizations prior to noise power spectra (NPS) estimation. NPS curves were normalized to account for differences in entrance exposure (as measured with an ion chamber), yielding estimates of the ENNPS for each technique. Results suggest that mid- and high-frequency noise in MITS planes is fairly equivalent in magnitude to noise in conventional tomosynthesis planes, but low-frequency noise is amplified in the most anterior and posterior reconstruction planes. Selecting the largest available number of projections (N = 71) does not incur any appreciable additive electronic noise penalty compared to using fewer projections for roughly equivalent cumulative exposure. Stochastic noise is minimized by maximizing N and NP but increases with increasing ANG. The noise trend results for NP and ANG are contrary to what would be predicted by simply considering the MITS matrix conditioning and likely result from the interplay between noise correlation and the polarity of the MITS filters. From this study, the authors conclude that the previously determined optimal MITS imaging strategy based on impulse response considerations produces somewhat suboptimal stochastic noise characteristics, but is probably still the best technique for MITS imaging of the chest.

Melodic Intonation Therapy in Chronic Aphasia: Evidence from a Pilot Randomized Controlled Trial

PubMed Central

Van Der Meulen, Ineke; Van De Sandt-Koenderman, Mieke W. M. E.; Heijenbrok, Majanka H.; Visch-Brink, Evy; Ribbers, Gerard M.

2016-01-01

Melodic Intonation Therapy (MIT) is a language production therapy for severely non-fluent aphasic patients using melodic intoning and rhythm to restore language. Although many studies have reported its beneficial effects on language production, randomized controlled trials (RCT) examining the efficacy of MIT are rare. In an earlier publication, we presented the results of an RCT on MIT in subacute aphasia and found that MIT was effective on trained and untrained items. Further, we observed a clear trend in improved functional language use after MIT: subacute aphasic patients receiving MIT improved considerably on language tasks measuring connected speech and daily life verbal communication. Here, we present the results of a pilot RCT on MIT in chronic aphasia and compare these to the results observed in subacute aphasia. We used a multicenter waiting-list RCT design. Patients with chronic (>1 year) post-stroke aphasia were randomly allocated to the experimental group (6 weeks MIT) or to the control group (6 weeks no intervention followed by 6 weeks MIT). Assessments were done at baseline (T1), after 6 weeks (T2), and 6 weeks later (T3). Efficacy was evaluated at T2 using univariable linear regression analyses. Outcome measures were chosen to examine several levels of therapy success: improvement on trained items, generalization to untrained items, and generalization to verbal communication. Of 17 included patients, 10 were allocated to the experimental condition and 7 to the control condition. MIT significantly improved repetition of trained items (β = 13.32, p = 0.02). This effect did not remain stable at follow-up assessment. In contrast to earlier studies, we found only a limited and temporary effect of MIT, without generalization to untrained material or to functional communication. The results further suggest that the effect of MIT in chronic aphasia is more restricted than its effect in earlier stages post stroke. This is in line with studies showing larger effects of aphasia therapy in earlier compared to later stages post stroke. The study was designed as an RCT, but was underpowered. The results therefore have to be interpreted cautiously and future larger studies are needed. Clinical Trial Registration: www.ClinicalTrials.gov, identifier NTR 1961. PMID:27847473

Spatial Modeling and Uncertainty Assessment of Fine Scale Surface Processes Based on Coarse Terrain Elevation Data

NASA Astrophysics Data System (ADS)

Rasera, L. G.; Mariethoz, G.; Lane, S. N.

2017-12-01

Frequent acquisition of high-resolution digital elevation models (HR-DEMs) over large areas is expensive and difficult. Satellite-derived low-resolution digital elevation models (LR-DEMs) provide extensive coverage of Earth's surface but at coarser spatial and temporal resolutions. Although useful for large scale problems, LR-DEMs are not suitable for modeling hydrologic and geomorphic processes at scales smaller than their spatial resolution. In this work, we present a multiple-point geostatistical approach for downscaling a target LR-DEM based on available high-resolution training data and recurrent high-resolution remote sensing images. The method aims at generating several equiprobable HR-DEMs conditioned to a given target LR-DEM by borrowing small scale topographic patterns from an analogue containing data at both coarse and fine scales. An application of the methodology is demonstrated by using an ensemble of simulated HR-DEMs as input to a flow-routing algorithm. The proposed framework enables a probabilistic assessment of the spatial structures generated by natural phenomena operating at scales finer than the available terrain elevation measurements. A case study in the Swiss Alps is provided to illustrate the methodology.

FE-DEM Analysis of the Effect of Tread Pattern on the Tractive Performance of Tires Operating on Sand

NASA Astrophysics Data System (ADS)

Nakashima, Hiroshi; Takatsu, Yuzuru; Shinone, Hisanori; Matsukawa, Hisao; Kasetani, Takahiro

Soil-tire system interaction is a fundamental and important research topic in terramechanics. We applied a 2D finite element, discrete element method (FE-DEM), using FEM for the tire and the bottom soil layer and DEM for the surface soil layer. Satisfactory performance analysis was achieved. In this study, to clarify the capabilities and limitations of the method for soil-tire interaction analysis, the tractive performance of real automobile tires with two different tread patterns—smooth and grooved—was analyzed by FE-DEM, and the numerical results compared with the experimental results obtained using an indoor traction measurement system. The analysis of tractive performance could be performed with sufficient accuracy by the proposed 2D dynamic FE-DEM. FE-DEM obtained larger drawbar pull for a tire with a grooved tread pattern, which was verified by the experimental results. Moreover, the result for the grooved tire showed almost the same gross tractive effort and similar running resistance as in experiments. However, for a tire with smooth tread pattern, the analyzed gross tractive effort and running resistance behaved differently than the experimental results, largely due to the difference in tire sinkage in FE-DEM.

Suppression of Structural Phase Transition in VO2 by Epitaxial Strain in Vicinity of Metal-insulator Transition

PubMed Central

Yang, Mengmeng; Yang, Yuanjun; Bin Hong; Wang, Liangxin; Hu, Kai; Dong, Yongqi; Xu, Han; Huang, Haoliang; Zhao, Jiangtao; Chen, Haiping; Song, Li; Ju, Huanxin; Zhu, Junfa; Bao, Jun; Li, Xiaoguang; Gu, Yueliang; Yang, Tieying; Gao, Xingyu; Luo, Zhenlin; Gao, Chen

2016-01-01

Mechanism of metal-insulator transition (MIT) in strained VO2 thin films is very complicated and incompletely understood despite three scenarios with potential explanations including electronic correlation (Mott mechanism), structural transformation (Peierls theory) and collaborative Mott-Peierls transition. Herein, we have decoupled coactions of structural and electronic phase transitions across the MIT by implementing epitaxial strain on 13-nm-thick (001)-VO2 films in comparison to thicker films. The structural evolution during MIT characterized by temperature-dependent synchrotron radiation high-resolution X-ray diffraction reciprocal space mapping and Raman spectroscopy suggested that the structural phase transition in the temperature range of vicinity of the MIT is suppressed by epitaxial strain. Furthermore, temperature-dependent Ultraviolet Photoelectron Spectroscopy (UPS) revealed the changes in electron occupancy near the Fermi energy EF of V 3d orbital, implying that the electronic transition triggers the MIT in the strained films. Thus the MIT in the bi-axially strained VO2 thin films should be only driven by electronic transition without assistance of structural phase transition. Density functional theoretical calculations further confirmed that the tetragonal phase across the MIT can be both in insulating and metallic states in the strained (001)-VO2/TiO2 thin films. This work offers a better understanding of the mechanism of MIT in the strained VO2 films. PMID:26975328

MicroRNA profile of silk gland reveals different silk yields of three silkworm strains.

PubMed

Qin, Sheng; Danso, Blessing; Zhang, Jing; Li, Juan; Liu, Na; Sun, Xia; Hou, Chengxiang; Luo, Heng; Chen, Keping; Zhang, Guozheng; Li, Muwang

2018-05-05

Silk proteins are synthesized and secreted by the silk gland. The differential gene expression in it leads to different silk yield among various silkworm strains. As crucial factors, microRNAs (miRNAs) regulate protein synthesis at post-transcriptional level in silk gland. MiRNAs expression level in the silk gland of three silkworm strains (Jingsong, Lan10 and Dazao) was analyzed and 33 differentially expressed miRNAs (DEMs) were discovered between JingSong (JS) and Lan10 (L10), 60 DEMs between JS and Dazao, 54 DEMs between L10 and Dazao respectively. The DEMs target genes were predicted combing with two different methods and their functions were annotated according to gene ontology. Our previous studies showed that a batch of genes related to silk yield were identified in JS and L10 strains by comparative transcriptome and quantitative trait loci (QTL) method. Thirteen DEMs whose target genes are related to protein biosynthesis processes were screened by combining with these researches. Twelve DEMs potentially regulate nineteen genes which exist in our QTL results. Six common DEMs potentially regulate the genes in both of previous results. Finally, five DEMs were selected to verify their expression levels between JS and L10 by qRT-PCR, which showed similar difference as the results of small RNA-sequencing. MiRNAs in the silk gland may directly affect silk protein biosynthesis in different silkworm strains. In current work, we identified a batch of DEMs which potentially regulate the genes related to silk yield. Further functionally study of these miRNAs will contribute to improve varieties and boost the silk yield. Our research provides a basis for studying these miRNAs and their functions in silk production. Copyright © 2018 Elsevier B.V. All rights reserved.

An improved method to represent DEM uncertainty in glacial lake outburst flood propagation using stochastic simulations

NASA Astrophysics Data System (ADS)

Watson, Cameron S.; Carrivick, Jonathan; Quincey, Duncan

2015-10-01

Modelling glacial lake outburst floods (GLOFs) or 'jökulhlaups', necessarily involves the propagation of large and often stochastic uncertainties throughout the source to impact process chain. Since flood routing is primarily a function of underlying topography, communication of digital elevation model (DEM) uncertainty should accompany such modelling efforts. Here, a new stochastic first-pass assessment technique was evaluated against an existing GIS-based model and an existing 1D hydrodynamic model, using three DEMs with different spatial resolution. The analysis revealed the effect of DEM uncertainty and model choice on several flood parameters and on the prediction of socio-economic impacts. Our new model, which we call MC-LCP (Monte Carlo Least Cost Path) and which is distributed in the supplementary information, demonstrated enhanced 'stability' when compared to the two existing methods, and this 'stability' was independent of DEM choice. The MC-LCP model outputs an uncertainty continuum within its extent, from which relative socio-economic risk can be evaluated. In a comparison of all DEM and model combinations, the Shuttle Radar Topography Mission (SRTM) DEM exhibited fewer artefacts compared to those with the Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model (ASTER GDEM), and were comparable to those with a finer resolution Advanced Land Observing Satellite Panchromatic Remote-sensing Instrument for Stereo Mapping (ALOS PRISM) derived DEM. Overall, we contend that the variability we find between flood routing model results suggests that consideration of DEM uncertainty and pre-processing methods is important when assessing flow routing and when evaluating potential socio-economic implications of a GLOF event. Incorporation of a stochastic variable provides an illustration of uncertainty that is important when modelling and communicating assessments of an inherently complex process.

Setting up virgin stress conditions in discrete element models.

PubMed

Rojek, J; Karlis, G F; Malinowski, L J; Beer, G

2013-03-01

In the present work, a methodology for setting up virgin stress conditions in discrete element models is proposed. The developed algorithm is applicable to discrete or coupled discrete/continuum modeling of underground excavation employing the discrete element method (DEM). Since the DEM works with contact forces rather than stresses there is a need for the conversion of pre-excavation stresses to contact forces for the DEM model. Different possibilities of setting up virgin stress conditions in the DEM model are reviewed and critically assessed. Finally, a new method to obtain a discrete element model with contact forces equivalent to given macroscopic virgin stresses is proposed. The test examples presented show that good results may be obtained regardless of the shape of the DEM domain.

Setting up virgin stress conditions in discrete element models

PubMed Central

Rojek, J.; Karlis, G.F.; Malinowski, L.J.; Beer, G.

2013-01-01

In the present work, a methodology for setting up virgin stress conditions in discrete element models is proposed. The developed algorithm is applicable to discrete or coupled discrete/continuum modeling of underground excavation employing the discrete element method (DEM). Since the DEM works with contact forces rather than stresses there is a need for the conversion of pre-excavation stresses to contact forces for the DEM model. Different possibilities of setting up virgin stress conditions in the DEM model are reviewed and critically assessed. Finally, a new method to obtain a discrete element model with contact forces equivalent to given macroscopic virgin stresses is proposed. The test examples presented show that good results may be obtained regardless of the shape of the DEM domain. PMID:27087731

EMDataBank unified data resource for 3DEM.

PubMed

Lawson, Catherine L; Patwardhan, Ardan; Baker, Matthew L; Hryc, Corey; Garcia, Eduardo Sanz; Hudson, Brian P; Lagerstedt, Ingvar; Ludtke, Steven J; Pintilie, Grigore; Sala, Raul; Westbrook, John D; Berman, Helen M; Kleywegt, Gerard J; Chiu, Wah

2016-01-04

Three-dimensional Electron Microscopy (3DEM) has become a key experimental method in structural biology for a broad spectrum of biological specimens from molecules to cells. The EMDataBank project provides a unified portal for deposition, retrieval and analysis of 3DEM density maps, atomic models and associated metadata (emdatabank.org). We provide here an overview of the rapidly growing 3DEM structural data archives, which include maps in EM Data Bank and map-derived models in the Protein Data Bank. In addition, we describe progress and approaches toward development of validation protocols and methods, working with the scientific community, in order to create a validation pipeline for 3DEM data. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Affective Responses to Repeated Sessions of High-Intensity Interval Training.

PubMed

Saanijoki, Tiina; Nummenmaa, Lauri; Eskelinen, Jari-Joonas; Savolainen, Anna M; Vahlberg, Tero; Kalliokoski, Kari K; Hannukainen, Jarna C

2015-12-01

Vigorous exercise feels unpleasant, and negative emotions may discourage adherence to regular exercise. We quantified the subjective affective responses to short-term high-intensity interval training (HIT) in comparison with moderate-intensity continuous training (MIT). Twenty-six healthy middle-age (mean age, 47 ± 5 yr; mean VO2peak, 34.2 ± 4.1 mL·kg⁻¹·min⁻¹) sedentary men were randomized into HIT (n = 13, 4-6 × 30 s of all-out cycling efforts at approximately 180% of peak workload with 4-min recovery) or MIT (n = 13, 40- to 60-min continuous cycling at 60% of peak workload) groups, performing six sessions within two weeks. Perceived exertion, stress, and affective state were recorded before, during, and after each session. Perceived exertion and arousal were higher, and affective state, more negative during the HIT than that during MIT sessions (P < 0.001). HIT versus MIT exercise acutely increased the experience of stress, tension, and irritation and decreased positive affect (P < 0.05). In addition, satisfaction was lower and pain and negative affect were higher in the HIT than those in the MIT group (P < 0.05). However, perceived exertion and displeasure experienced during exercise alleviated similarly in response to HIT and MIT over the 6 d of training. Peak oxygen consumption increased (P < 0.001) after intervention (HIT, 34.7 ± 3.9 vs 36.7 ± 4.5; MIT, 33.9 ± 4.6 vs 35.0 ± 4.6) and was not different between HIT and MIT (P = 0.28 for group × training). Short-term HIT and MIT are equally effective in improving aerobic fitness, but HIT increases experience of negative emotions and exertion in sedentary middle-age men. This may limit the adherence to this time-effective training mode, even though displeasure lessens over time and suggests similar mental adaptations to both MIT and HIT.

AMES Stereo Pipeline Derived DEM Accuracy Experiment Using LROC-NAC Stereopairs and Weighted Spatial Dependence Simulation for Lunar Site Selection

NASA Astrophysics Data System (ADS)

Laura, J. R.; Miller, D.; Paul, M. V.

2012-03-01

An accuracy assessment of AMES Stereo Pipeline derived DEMs for lunar site selection using weighted spatial dependence simulation and a call for outside AMES derived DEMs to facilitate a statistical precision analysis.

Detecting Man-in-the-Middle Attacks against Transport Layer Security Connections with Timing Analysis

DTIC Science & Technology

2011-09-15

Networks (VPNs), TLS protects massive amounts of private information, and protecting this data from Man-in-the-Middle ( MitM ) attacks is imperative to...keeping the information secure. This thesis illustrates how an attacker can successfully perform a MitM attack against a TLS connection without alerting...mechanism a user has against a MitM . The goal for this research is to determine if a time threshold exists that can indicate the presence of a MitM in this

Comparison of Multi-Scale Digital Elevation Models for Defining Waterways and Catchments Over Large Areas

NASA Astrophysics Data System (ADS)

Harris, B.; McDougall, K.; Barry, M.

2012-07-01

Digital Elevation Models (DEMs) allow for the efficient and consistent creation of waterways and catchment boundaries over large areas. Studies of waterway delineation from DEMs are usually undertaken over small or single catchment areas due to the nature of the problems being investigated. Improvements in Geographic Information Systems (GIS) techniques, software, hardware and data allow for analysis of larger data sets and also facilitate a consistent tool for the creation and analysis of waterways over extensive areas. However, rarely are they developed over large regional areas because of the lack of available raw data sets and the amount of work required to create the underlying DEMs. This paper examines definition of waterways and catchments over an area of approximately 25,000 km2 to establish the optimal DEM scale required for waterway delineation over large regional projects. The comparative study analysed multi-scale DEMs over two test areas (Wivenhoe catchment, 543 km2 and a detailed 13 km2 within the Wivenhoe catchment) including various data types, scales, quality, and variable catchment input parameters. Historic and available DEM data was compared to high resolution Lidar based DEMs to assess variations in the formation of stream networks. The results identified that, particularly in areas of high elevation change, DEMs at 20 m cell size created from broad scale 1:25,000 data (combined with more detailed data or manual delineation in flat areas) are adequate for the creation of waterways and catchments at a regional scale.

Effect of elevation resolution on evapotranspiration simulations using MODFLOW.

PubMed

Kambhammettu, B V N P; Schmid, Wolfgang; King, James P; Creel, Bobby J

2012-01-01

Surface elevations represented in MODFLOW head-dependent packages are usually derived from digital elevation models (DEMs) that are available at much high resolution. Conventional grid refinement techniques to simulate the model at DEM resolution increases computational time, input file size, and in many cases are not feasible for regional applications. This research aims at utilizing the increasingly available high resolution DEMs for effective simulation of evapotranspiration (ET) in MODFLOW as an alternative to grid refinement techniques. The source code of the evapotranspiration package is modified by considering for a fixed MODFLOW grid resolution and for different DEM resolutions, the effect of variability in elevation data on ET estimates. Piezometric head at each DEM cell location is corrected by considering the gradient along row and column directions. Applicability of the research is tested for the lower Rio Grande (LRG) Basin in southern New Mexico. The DEM at 10 m resolution is aggregated to resampled DEM grid resolutions which are integer multiples of MODFLOW grid resolution. Cumulative outflows and ET rates are compared at different coarse resolution grids. Results of the analysis conclude that variability in depth-to-groundwater within the MODFLOW cell is a major contributing parameter to ET outflows in shallow groundwater regions. DEM aggregation methods for the LRG Basin have resulted in decreased volumetric outflow due to the formation of a smoothing error, which lowered the position of water table to a level below the extinction depth. © 2011, The Author(s). Ground Water © 2011, National Ground Water Association.

The My Meal Intake Tool (M-MIT): Validity of a Patient Self- Assessment for Food and Fluid Intake at a Single Meal.

PubMed

McCullough, J; Keller, H

2018-01-01

Hospital malnutrition is an under-recognized issue that leads to a variety of adverse outcomes, especially for older adults. Food/fluid intake (FFI) monitoring in hospital can be used to identify those who are improving and those who need further treatment. Current monitoring practices such as calorie counts are impractical for all patients and a patient-completed tool, if valid, could support routine FFI monitoring. The aim of this research was to determine whether the patient-completed My Meal Intake Tool (M-MIT) can accurately represent FFI at a single meal. Cross-sectional, multi-site. Four acute care hospitals in Canada. 120 patients (65+ yrs, adequate cognition). Participants completed M-MIT for a single meal. Food and fluid waste was visually estimated by a research dietitian at each hospital. Sensitivity (Se), specificity (Sp) and overall agreement were calculated for both food and fluid intake by comparing M-MIT and dietitian estimations to determine criterion validity of M-MIT. Patient and research dietitian comments were used to make revisions to the M-MIT. Using a cut-point of ≤50% intake, Se was 76.2% and 61.9% and Sp was 74.0% and 80.5% for solid and fluids respectively (p<0.001). M-MIT identified a greater proportion of participants (37.2%) as having low FFI (≤50%) than dietitians (25.0%), as well as a greater proportion identified with low fluid intake (28.3% vs. 24.6%). Modest revisions were made to improve the tool. This study has demonstrated initial validity of M-MIT for use in older patients with adequate cognition. Use of M-MIT could promote FFI monitoring as a routine practice to make clinical decisions about care.

Effective degradation of methylisothiazolone biocide using ozone: Kinetics, mechanisms, and decreases in toxicity.

PubMed

Li, Ang; Wu, Qian-Yuan; Tian, Gui-Peng; Hu, Hong-Ying

2016-12-01

Methylisothiazolone (MIT) is a common biocide that is widely used in water-desalination reverse-osmosis processes. The transformation of MIT during water treatment processes is poorly understood. The kinetics and mechanisms involved in the degradation of MIT during ozonation were investigated in this study. Ozonation was found to be a useful way of degrading MIT in water, and the degradation rate constant was 0.11 (±0.1) × 10 3  L/(mol·s). The degradation rate constant did not change when the pH was increased from 3 to 9. The pre-exponential factor A and the activation energy E a for the ozonation process were 7.564 × 10 13  L/(mol·s) and 66.74 kJ/mol, respectively. The decrease in the MIT concentration and the amount of ozone consumed were measured, and the stoichiometric factor α for the ozone consumption to MIT removal ratio was found to be 1.8. Several ozonation products were detected using time-of-flight mass spectrometry. Almost 32% of the organic sulfur in the MIT was oxidized to release sulfate ions, which caused a decrease in pH. Sulfur atoms were oxidized to sulfone species and then hydrolyzed to give sulfate during ozonation. Addition reactions involving carbon-carbon double bonds and the oxidation of α-carbon atoms also occurred. MIT was found to be lethal to Daphnia magna Straus (D. magna) with a median lethal concentration of 18.2 μmol/L. Even though the primary ozonation products of MIT still showed some toxicity to D. magna, ozone could minimize the toxic effect after a long reaction time. Copyright © 2016 Elsevier Ltd. All rights reserved.

EVALUATING SOIL EROSION PARAMETER ESTIMATES FROM DIFFERENT DATA SOURCES

EPA Science Inventory

Topographic factors and soil loss estimates that were derived from thee data sources (STATSGO, 30-m DEM, and 3-arc second DEM) were compared. Slope magnitudes derived from the three data sources were consistently different. Slopes from the DEMs tended to provide a flattened sur...

Hydrologic validation of a structure-from-motion DEM derived from low-altitude UAV imagery

NASA Astrophysics Data System (ADS)

Steiner, Florian; Marzolff, Irene; d'Oleire-Oltmanns, Sebastian

2015-04-01

The increasing ease of use of current Unmanned Aerial Vehicles (UAVs) and 3D image processing software has spurred the number of applications relying on high-resolution topographic datasets. Of particular significance in this field is "structure from motion" (SfM), a photogrammetric technique used to generate low-cost digital elevation models (DEMs) for erosion budgeting, measuring of glaciers/lava-flows, archaeological applications and others. It was originally designed to generate 3D-models of buildings, based on unordered collections of images and has become increasingly common in geoscience applications during the last few years. Several studies on the accuracy of this technique already exist, in which the SfM data is mostly compared with Lidar-generated terrain data. The results are mainly positive, indicating that the technique is suitable for such applications. This work aims at validating very high resolution SfM DEMs with a different approach: Not the original elevation data is validated, but data on terrain-related hydrological and geomorphometric parameters derived from the DEM. The study site chosen for this analysis is an abandoned agricultural field near the city of Taroudant, in the semi-arid southern part of Morocco. The site is characterized by aggressive rill and gully erosion and is - apart from sparsely scattered shrub cover - mainly featureless. An area of 5.7 ha, equipped with 30 high-precision ground control points (GCPs), was covered with an unmanned aerial vehicle (UAV) in two different heights (85 and 170 m). A selection of 160 images was used to generate several high-resolution DEMs (2 and 5 cm resolution) of the area using the fully automated SfM software AGISOFT Photoscan. For comparison purposes, a conventional photogrammetry-based workflow using the Leica Photogrammetry Suite was used to generate a DEM with a resolution of 5 cm (LPS DEM). The evaluation is done by comparison of the SfM DEM with the derived orthoimages and the LPS DEM. Parameters evaluated include the flow accumulation, the extracted thalweg networks, slope and exposition. Thus, the question asked is not "Is the height at this specific point accurate compared to a true reference height?", but rather "Does the surface runoff modelled from this DEM behave in the same way as it does in reality?". This means that the DEM will be validated on a functional basis, examining the accuracy of hydrological connectivity and networks. The results of this work may help in the establishment of the SfM technique in geoscience applications, and give an idea of the hydrologic accuracy and reliability of such DEMs.

Improved Neural Processing Efficiency in a Chronic Aphasia Patient Following Melodic Intonation Therapy: A Neuropsychological and Functional MRI Study

PubMed Central

Tabei, Ken-ichi; Satoh, Masayuki; Nakano, Chizuru; Ito, Ai; Shimoji, Yasuo; Kida, Hirotaka; Sakuma, Hajime; Tomimoto, Hidekazu

2016-01-01

Melodic intonation therapy (MIT) is a treatment program for the rehabilitation of aphasic patients with speech production disorders. We report a case of severe chronic non-fluent aphasia unresponsive to several years of conventional therapy that showed a marked improvement following intensive 9-day training on the Japanese version of MIT (MIT-J). The purpose of this study was to verify the efficacy of MIT-J by functional assessment and examine associated changes in neural processing by functional magnetic resonance imaging. MIT improved language output and auditory comprehension, and decreased the response time for picture naming. Following MIT-J, an area of the right hemisphere was less activated on correct naming trials than compared with before training but similarly activated on incorrect trials. These results suggest that the aphasic symptoms of our patient were improved by increased neural processing efficiency and a concomitant decrease in cognitive load. PMID:27698650

Modulation of mitochondrial activity in HaCaT keratinocytes by the cell penetrating peptide Z-Gly-RGD(DPhe)-mitoparan.

PubMed

Richardson, Adam; Muir, Lewis; Mousdell, Sasha; Sexton, Darren; Jones, Sarah; Howl, John; Ross, Kehinde

2018-01-30

Biologically active cell penetrating peptides (CPPs) are an emerging class of therapeutic agent. The wasp venom peptide mastoparan is an established CPP that modulates mitochondrial activity and triggers caspase-dependent apoptosis in cancer cells, as does the mastoparan analogue mitoparan (mitP). Mitochondrial depolarisation and activation of the caspase cascade also underpins the action of dithranol, a topical agent for treatment of psoriasis. The effects of a potent mitP analogue on mitochondrial activity were therefore examined to assess its potential as a novel approach for targeting mitochondria for the treatment of psoriasis. In HaCaT keratinocytes treated with the mitP analogue Z-Gly-RGD(DPhe)-mitP for 24 h, a dose-dependent loss of mitochondrial activity was observed using the methyl-thiazolyl-tetrazolium (MTT) assay. At 10 μmol L -1 , MTT activity was less than 30% that observed in untreated cells. Staining with the cationic dye JC-1 suggested that Z-Gly-RGD(DPhe)-mitP also dissipated the mitochondrial membrane potential, with a threefold increase in mitochondrial depolarisation levels. However, caspase activity appeared to be reduced by 24 h exposure to Z-Gly-RGD(DPhe)-mitP treatment. Furthermore, Z-Gly-RGD(DPhe)-mitP treatment had little effect on overall cell viability. Our findings suggest Z-Gly-RGD(DPhe)-mitP promotes the loss of mitochondrial activity but does not appear to evoke apoptosis in HaCaT keratinocytes.

Tracking moving identities: after attending the right location, the identity does not come for free.

PubMed

Pinto, Yaïr; Scholte, H Steven; Lamme, V A F

2012-01-01

Although tracking identical moving objects has been studied since the 1980's, only recently the study into tracking moving objects with distinct identities has started (referred to as Multiple Identity Tracking, MIT). So far, only behavioral studies into MIT have been undertaken. These studies have left a fundamental question regarding MIT unanswered, is MIT a one-stage or a two-stage process? According to the one-stage model, after a location has been attended, the identity is released without effort. However, according to the two-stage model, there are two effortful stages in MIT, attending to a location, and attending to the identity of the object at that location. In the current study we investigated this question by measuring brain activity in response to tracking familiar and unfamiliar targets. Familiarity is known to automate effortful processes, so if attention to identify the object is needed, this should become easier. However, if no such attention is needed, familiarity can only affect other processes (such as memory for the target set). Our results revealed that on unfamiliar trials neural activity was higher in both attentional networks, and visual identification networks. These results suggest that familiarity in MIT automates attentional identification processes, thus suggesting that attentional identification is needed in MIT. This then would imply that MIT is essentially a two-stage process, since after attending the location, the identity does not seem to come for free.

Registering Thematic Mapper imagery to digital elevation models

NASA Technical Reports Server (NTRS)

Frew, J.

1984-01-01

The problems encountered when attempting to register Landsat Thematic Mapper (TM) data to U.S. geological survey digital elevation models (DEMs) are examined. It is shown that TM and DEM data are not available in the same map projection, necessitating geometric transformation of one of the data type, that the TM data are not accurately located in their nominal projection, and that TM data have higher resolution than most DEM data, but oversampling the DEM data to TM resolution introduces systematic noise. Further work needed in this area is discussed.

Pulse fracture simulation in shale rock reservoirs: DEM and FEM-DEM approaches

NASA Astrophysics Data System (ADS)

González, José Manuel; Zárate, Francisco; Oñate, Eugenio

2018-07-01

In this paper we analyze the capabilities of two numerical techniques based on DEM and FEM-DEM approaches for the simulation of fracture in shale rock caused by a pulse of pressure. We have studied the evolution of fracture in several fracture scenarios related to the initial stress state in the soil or the pressure pulse peak. Fracture length and type of failure have been taken as reference for validating the models. The results obtained show a good approximation to FEM results from the literature.

Digital elevation model of King Edward VII Peninsula, West Antarctica, from SAR interferometry and ICESat laser altimetry

USGS Publications Warehouse

Baek, S.; Kwoun, Oh-Ig; Braun, Andreas; Lu, Z.; Shum, C.K.

2005-01-01

We present a digital elevation model (DEM) of King Edward VII Peninsula, Sulzberger Bay, West Antarctica, developed using 12 European Remote Sensing (ERS) synthetic aperture radar (SAR) scenes and 24 Ice, Cloud, and land Elevation Satellite (ICESat) laser altimetry profiles. We employ differential interferograms from the ERS tandem mission SAR scenes acquired in the austral fall of 1996, and four selected ICESat laser altimetry profiles acquired in the austral fall of 2004, as ground control points (GCPs) to construct an improved geocentric 60-m resolution DEM over the grounded ice region. We then extend the DEM to include two ice shelves using ICESat profiles via Kriging. Twenty additional ICESat profiles acquired in 2003-2004 are used to assess the accuracy of the DEM. After accounting for radar penetration depth and predicted surface changes, including effects due to ice mass balance, solid Earth tides, and glacial isostatic adjustment, in part to account for the eight-year data acquisition discrepancy, the resulting difference between the DEM and ICESat profiles is -0.57 ?? 5.88 m. After removing the discrepancy between the DEM and ICESat profiles for a final combined DEM using a bicubic spline, the overall difference is 0.05 ?? 1.35 m. ?? 2005 IEEE.

Absolute and relative height-pixel accuracy of SRTM-GL1 over the South American Andean Plateau

NASA Astrophysics Data System (ADS)

Satge, Frédéric; Denezine, Matheus; Pillco, Ramiro; Timouk, Franck; Pinel, Sébastien; Molina, Jorge; Garnier, Jérémie; Seyler, Frédérique; Bonnet, Marie-Paule

2016-11-01

Previously available only over the Continental United States (CONUS), the 1 arc-second mesh size (spatial resolution) SRTM-GL1 (Shuttle Radar Topographic Mission - Global 1) product has been freely available worldwide since November 2014. With a relatively small mesh size, this digital elevation model (DEM) provides valuable topographic information over remote regions. SRTM-GL1 is assessed for the first time over the South American Andean Plateau in terms of both the absolute and relative vertical point-to-point accuracies at the regional scale and for different slope classes. For comparison, SRTM-v4 and GDEM-v2 Global DEM version 2 (GDEM-v2) generated by ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) are also considered. A total of approximately 160,000 ICESat/GLAS (Ice, Cloud and Land Elevation Satellite/Geoscience Laser Altimeter System) data are used as ground reference measurements. Relative error is often neglected in DEM assessments due to the lack of reference data. A new methodology is proposed to assess the relative accuracies of SRTM-GL1, SRTM-v4 and GDEM-v2 based on a comparison with ICESat/GLAS measurements. Slope values derived from DEMs and ICESat/GLAS measurements from approximately 265,000 ICESat/GLAS point pairs are compared using quantitative and categorical statistical analysis introducing a new index: the False Slope Ratio (FSR). Additionally, a reference hydrological network is derived from Google Earth and compared with river networks derived from the DEMs to assess each DEM's potential for hydrological applications over the region. In terms of the absolute vertical accuracy on a global scale, GDEM-v2 is the most accurate DEM, while SRTM-GL1 is more accurate than SRTM-v4. However, a simple bias correction makes SRTM-GL1 the most accurate DEM over the region in terms of vertical accuracy. The relative accuracy results generally did not corroborate the absolute vertical accuracy. GDEM-v2 presents the lowest statistical results based on the relative accuracy, while SRTM-GL1 is the most accurate. Vertical accuracy and relative accuracy are two independent components that must be jointly considered when assessing a DEM's potential. DEM accuracies increased with slope. In terms of hydrological potential, SRTM products are more accurate than GDEM-v2. However, the DEMs exhibit river extraction limitations over the region due to the low regional slope gradient.

Physik gestern und heute: Visualisierung mit der Schlierenmethode

NASA Astrophysics Data System (ADS)

Heering, Peter

2006-07-01

Der Name des österreichischen Forschers Ernst Mach ist heute noch mit der Schallgeschwindigkeit verbunden. Diese Auszeichnung resultiert aus Machs Untersuchungen, wie sich Projektile mit Überschallgeschwindigkeit durch die Luft bewegen. Gerade in jüngster Zeit hat die Anwendung derartiger Methoden durch technische Modifikationen wieder einen Aufschwung erfahren.

Exploring Surfaces of Nanomaterials - MIT Spectrum

Science.gov Websites

Topics About Search for: Search Massachusetts Institute of Technology Yang Shao-Horn is tackling the inspired by them to work here." Learn More Yang Shao-Horn Topics battery Energy Materials Science Latest Stories Spectrum Issues Topics About Popular Latest MIT Campaign for a Better World MIT Campaign

Historisches Rätsel Physik mit Gewehr und Eiern

NASA Astrophysics Data System (ADS)

Loos, Andreas

2003-11-01

Es fing schon gut an: Mit zehn Jahren saß der begabte Junge bereits in der Universität, wo ihn kein Geringerer als sein Vater persönlich unterrichtete. Damit schlug dieser zwei Fliegen mit einer Klappe: Sein Sohn lernte etwas Gescheites, und er war zugleich in sicherer Obhut.

Announcing the Availability of the MIT SMASS and SMASSIR Data Sets

NASA Technical Reports Server (NTRS)

Binzel, R. P.; Bus, S. J.; Burbine, T. H.; Rivkin, A. S.

2001-01-01

We announce the release of visible and near-infrared reflectance spectroscopy measurements for nearly 2000 asteroids obtained by the MIT Small Main-Belt Asteroid Spectroscopic Survey (SMASS) program. Data are being released via http://smass.mit.edu. Additional information is contained in the original extended abstract.

Incremental terrain processing for large digital elevation models

NASA Astrophysics Data System (ADS)

Ye, Z.

2012-12-01

Incremental terrain processing for large digital elevation models Zichuan Ye, Dean Djokic, Lori Armstrong Esri, 380 New York Street, Redlands, CA 92373, USA (E-mail: zye@esri.com, ddjokic@esri.com , larmstrong@esri.com) Efficient analyses of large digital elevation models (DEM) require generation of additional DEM artifacts such as flow direction, flow accumulation and other DEM derivatives. When the DEMs to analyze have a large number of grid cells (usually > 1,000,000,000) the generation of these DEM derivatives is either impractical (it takes too long) or impossible (software is incapable of processing such a large number of cells). Different strategies and algorithms can be put in place to alleviate this situation. This paper describes an approach where the overall DEM is partitioned in smaller processing units that can be efficiently processed. The processed DEM derivatives for each partition can then be either mosaicked back into a single large entity or managed on partition level. For dendritic terrain morphologies, the way in which partitions are to be derived and the order in which they are to be processed depend on the river and catchment patterns. These patterns are not available until flow pattern of the whole region is created, which in turn cannot be established upfront due to the size issues. This paper describes a procedure that solves this problem: (1) Resample the original large DEM grid so that the total number of cells is reduced to a level for which the drainage pattern can be established. (2) Run standard terrain preprocessing operations on the resampled DEM to generate the river and catchment system. (3) Define the processing units and their processing order based on the river and catchment system created in step (2). (4) Based on the processing order, apply the analysis, i.e., flow accumulation operation to each of the processing units, at the full resolution DEM. (5) As each processing unit is processed based on the processing order defined in (3), compare the resulting drainage pattern with the drainage pattern established at the coarser scale and adjust the drainage boundaries and rivers if necessary.

Minimum ignition temperature of nano and micro Ti powder clouds in the presence of inert nano TiO2 powder.

PubMed

Yuan, Chunmiao; Amyotte, Paul R; Hossain, Md Nur; Li, Chang

2014-06-30

Minimum ignition temperature (MIT) of micro Ti powder increased gradually with increases in nano-sized TiO2 employed as an inertant. Solid TiO2 inertant significantly reduced ignition hazard of micro Ti powder in contact with hot surfaces. The MIT of nano Ti powder remained low (583 K), however, even with 90% TiO2. The MIT of micro Ti powder, when mixed with nano Ti powder at concentrations as low as 10%, decreased so dramatically that its application as a solid fuel may be possible. A simple MIT model was proposed for aggregate particle size estimation and better understanding of the inerting effect of nano TiO2 on MIT. Estimated particle size was 1.46-1.51 μm larger than that in the 20-L sphere due to poor dispersion in the BAM oven. Calculated MITs were lower than corresponding empirically determined values for micro Ti powder because nano-sized TiO2 coated the micro Ti powder, thereby decreasing its reaction kinetics. In the case of nano Ti powder, nano-sized TiO2 facilitated dispersion of nano Ti powder which resulted in a calculated MIT that was greater than the experimentally determined value. Copyright © 2014 Elsevier B.V. All rights reserved.

Best practice for motor imagery: a systematic literature review on motor imagery training elements in five different disciplines

PubMed Central

2011-01-01

Background The literature suggests a beneficial effect of motor imagery (MI) if combined with physical practice, but detailed descriptions of MI training session (MITS) elements and temporal parameters are lacking. The aim of this review was to identify the characteristics of a successful MITS and compare these for different disciplines, MI session types, task focus, age, gender and MI modification during intervention. Methods An extended systematic literature search using 24 databases was performed for five disciplines: Education, Medicine, Music, Psychology and Sports. References that described an MI intervention that focused on motor skills, performance or strength improvement were included. Information describing 17 MITS elements was extracted based on the PETTLEP (physical, environment, timing, task, learning, emotion, perspective) approach. Seven elements describing the MITS temporal parameters were calculated: study duration, intervention duration, MITS duration, total MITS count, MITS per week, MI trials per MITS and total MI training time. Results Both independent reviewers found 96% congruity, which was tested on a random sample of 20% of all references. After selection, 133 studies reporting 141 MI interventions were included. The locations of the MITS and position of the participants during MI were task-specific. Participants received acoustic detailed MI instructions, which were mostly standardised and live. During MI practice, participants kept their eyes closed. MI training was performed from an internal perspective with a kinaesthetic mode. Changes in MI content, duration and dosage were reported in 31 MI interventions. Familiarisation sessions before the start of the MI intervention were mentioned in 17 reports. MI interventions focused with decreasing relevance on motor-, cognitive- and strength-focused tasks. Average study intervention lasted 34 days, with participants practicing MI on average three times per week for 17 minutes, with 34 MI trials. Average total MI time was 178 minutes including 13 MITS. Reporting rate varied between 25.5% and 95.5%. Conclusions MITS elements of successful interventions were individual, supervised and non-directed sessions, added after physical practice. Successful design characteristics were dominant in the Psychology literature, in interventions focusing on motor and strength-related tasks, in interventions with participants aged 20 to 29 years old, and in MI interventions including participants of both genders. Systematic searching of the MI literature was constrained by the lack of a defined MeSH term. PMID:21682867

Reanalysis of the DEMS Nested Case-Control Study of Lung Cancer and Diesel Exhaust: Suitability for Quantitative Risk Assessment

PubMed Central

Crump, Kenny S; Van Landingham, Cynthia; Moolgavkar, Suresh H; McClellan, Roger

2015-01-01

The International Agency for Research on Cancer (IARC) in 2012 upgraded its hazard characterization of diesel engine exhaust (DEE) to “carcinogenic to humans.” The Diesel Exhaust in Miners Study (DEMS) cohort and nested case-control studies of lung cancer mortality in eight U.S. nonmetal mines were influential in IARC’s determination. We conducted a reanalysis of the DEMS case-control data to evaluate its suitability for quantitative risk assessment (QRA). Our reanalysis used conditional logistic regression and adjusted for cigarette smoking in a manner similar to the original DEMS analysis. However, we included additional estimates of DEE exposure and adjustment for radon exposure. In addition to applying three DEE exposure estimates developed by DEMS, we applied six alternative estimates. Without adjusting for radon, our results were similar to those in the original DEMS analysis: all but one of the nine DEE exposure estimates showed evidence of an association between DEE exposure and lung cancer mortality, with trend slopes differing only by about a factor of two. When exposure to radon was adjusted, the evidence for a DEE effect was greatly diminished, but was still present in some analyses that utilized the three original DEMS DEE exposure estimates. A DEE effect was not observed when the six alternative DEE exposure estimates were utilized and radon was adjusted. No consistent evidence of a DEE effect was found among miners who worked only underground. This article highlights some issues that should be addressed in any use of the DEMS data in developing a QRA for DEE. PMID:25857246

Development of a LiDAR derived digital elevation model (DEM) as Input to a METRANS geographic information system (GIS).

DOT National Transportation Integrated Search

2011-05-01

This report describes an assessment of digital elevation models (DEMs) derived from : LiDAR data for a subset of the Ports of Los Angeles and Long Beach. A methodology : based on Monte Carlo simulation was applied to investigate the accuracy of DEMs ...

Visualizing impact structures using high-resolution LiDAR-derived DEMs: A case study of two structures in Missouri

USGS Publications Warehouse

Finn, Michael P.; Krizanich, Gary W.; Evans, Kevin R.; Cox, Melissa R.; Yamamoto, Kristina H.

2015-01-01

Evidence suggests that a crypto-explosive hypothesis and a meteorite impact hypothesis may be partly correct in explaining several anomalous geological features in the middle of the United States. We used a primary geographic information science (GIScience) technique of creating a digital elevation model (DEM) of two of these features that occur in Missouri. The DEMs were derived from airborne light detection and ranging, or LiDAR. Using these DEMs, we characterized the Crooked Creek structure in southern Crawford County and the Weaubleau structure in southeastern St. Clair County, Missouri. The mensuration and study of exposed and buried impact craters implies that the craters may have intrinsic dimensions which could only be produced by collision. The results show elevations varying between 276 and 348 m for Crooked Creek and between 220 and 290 m for Weaubleau structure. These new high- resolution DEMs are accurate enough to allow for precise measurements and better interpretations of geological structures, particularly jointing in the carbonate rocks, and they show greater definition of the central uplift area in the Weaubleau structure than publicly available DEMs.

Generating DEM from LIDAR data - comparison of available software tools

NASA Astrophysics Data System (ADS)

Korzeniowska, K.; Lacka, M.

2011-12-01

In recent years many software tools and applications have appeared that offer procedures, scripts and algorithms to process and visualize ALS data. This variety of software tools and of "point cloud" processing methods contributed to the aim of this study: to assess algorithms available in various software tools that are used to classify LIDAR "point cloud" data, through a careful examination of Digital Elevation Models (DEMs) generated from LIDAR data on a base of these algorithms. The works focused on the most important available software tools: both commercial and open source ones. Two sites in a mountain area were selected for the study. The area of each site is 0.645 sq km. DEMs generated with analysed software tools ware compared with a reference dataset, generated using manual methods to eliminate non ground points. Surfaces were analysed using raster analysis. Minimum, maximum and mean differences between reference DEM and DEMs generated with analysed software tools were calculated, together with Root Mean Square Error. Differences between DEMs were also examined visually using transects along the grid axes in the test sites.

Automated sinkhole detection using a DEM subsetting technique and fill tools at Mammoth Cave National Park

NASA Astrophysics Data System (ADS)

Wall, J.; Bohnenstiehl, D. R.; Levine, N. S.

2013-12-01

An automated workflow for sinkhole detection is developed using Light Detection and Ranging (Lidar) data from Mammoth Cave National Park (MACA). While the park is known to sit within a karst formation, the generally dense canopy cover and the size of the park (~53,000 acres) creates issues for sinkhole inventorying. Lidar provides a useful remote sensing technology for peering beneath the canopy in hard to reach areas of the park. In order to detect sinkholes, a subsetting technique is used to interpolate a Digital Elevation Model (DEM) thereby reducing edge effects. For each subset, standard GIS fill tools are used to fill depressions within the DEM. The initial DEM is then subtracted from the filled DEM resulting in detected depressions or sinkholes. Resulting depressions are then described in terms of size and geospatial trend.

An algorithm to extract more accurate stream longitudinal profiles from unfilled DEMs

NASA Astrophysics Data System (ADS)

Byun, Jongmin; Seong, Yeong Bae

2015-08-01

Morphometric features observed from a stream longitudinal profile (SLP) reflect channel responses to lithological variation and changes in uplift or climate; therefore, they constitute essential indicators in the studies for the dynamics between tectonics, climate, and surface processes. The widespread availability of digital elevation models (DEMs) and their processing enable semi-automatic extraction of SLPs as well as additional stream profile parameters, thus reducing the time spent for extracting them and simultaneously allowing regional-scale studies of SLPs. However, careful consideration is required to extract SLPs directly from a DEM, because the DEM must be altered by depression filling process to ensure the continuity of flows across it. Such alteration inevitably introduces distortions to the SLP, such as stair steps, bias of elevation values, and inaccurate stream paths. This paper proposes a new algorithm, called maximum depth tracing algorithm (MDTA), to extract more accurate SLPs using depression-unfilled DEMs. The MDTA supposes that depressions in DEMs are not necessarily artifacts to be removed, and that elevation values within them are useful to represent more accurately the real landscape. To ensure the continuity of flows even across the unfilled DEM, the MDTA first determines the outlet of each depression and then reverses flow directions of the cells on the line of maximum depth within each depression, beginning from the outlet and toward the sink. It also calculates flow accumulation without disruption across the unfilled DEM. Comparative analysis with the profiles extracted by the hydrologic functions implemented in the ArcGIS™ was performed to illustrate the benefits from the MDTA. It shows that the MDTA provides more accurate stream paths on depression areas, and consequently reduces distortions of the SLPs derived from the paths, such as exaggerated elevation values and negatively biased slopes that are commonly observed in the SLPs built using the ArcGIS™. The algorithm proposed here, therefore, could aid all the studies requiring more reliable stream paths and SLPs from DEMs.

Evaluation of ASTER GDEM with respect to SRTM for Chandra-Bhaga Basin, Indian Himalaya

NASA Astrophysics Data System (ADS)

Pandey, P.

2011-12-01

Evaluation of ASTER GDEM with respect to SRTM for Chandra-Bhaga Basin, Indian Himalaya Pratima Pandey, G. Venkataraman Centre of Studies in Resources Engineering, IIT Bombay, Mumbai, India Abstract A digital elevation model (DEM) is a simple representation of a surface in 3 dimensional way with height as the third dimension along with x and y in rectangular axes. DEM has wide applications in various areas like disaster management, hydrology and water management, geomorphology and in urban development. Valuable information about a terrain can be inferred by exploiting a DEM in proper way. Study of DEM becomes very useful for studying mountainous terrain such as Himalaya which is otherwise hard to access due to harsh weather and inaccessibility. DEM can be generated by aerial photos, stereo images from satellites and toposheet. SRTM and ASTER GDEM are DEM which generated from satellite images and covers maximum parts of the earth. Shuttle Radar Topography Mission (SRTM) is a good quality DEM created in 2000 covering the globe between 600 N and 580 S with 3 arc second (90m) resolution. SRTM is available freely for research. ASTER GDEM is recently released global DEM created using ASTER scenes and made available to the world since June 2009 for carrying out research. ASTER GDEM covers land surfaces between 83°N and 83°S with estimated accuracies of 20 meters vertical data and 30 meters for horizontal data. So ASTER GDEM supposed to be more sophisticated. The present study aims at comparing the ASTER GDEM with the SRTM and ASTER DEM and evaluating its relative characteristics for undulating surface and glaciers of Chandra-Bhaga sub-basin situated in Lahual-Spiti district of Himachal Pradesh, Indian Himalaya. Once the characteristics of ASTER GDEM are evaluated for Himalayan terrain it can be used for various studies involving rugged terrain of Himalaya.

Back to the Future: Have Remotely Sensed Digital Elevation Models Improved Hydrological Parameter Extraction?

NASA Astrophysics Data System (ADS)

Jarihani, B.

2015-12-01

Digital Elevation Models (DEMs) that accurately replicate both landscape form and processes are critical to support modeling of environmental processes. Pre-processing analysis of DEMs and extracting characteristics of the watershed (e.g., stream networks, catchment delineation, surface and subsurface flow paths) is essential for hydrological and geomorphic analysis and sediment transport. This study investigates the status of the current remotely-sensed DEMs in providing advanced morphometric information of drainage basins particularly in data sparse regions. Here we assess the accuracy of three available DEMs: (i) hydrologically corrected "H-DEM" of Geoscience Australia derived from the Shuttle Radar Topography Mission (SRTM) data; (ii) the Advanced Spaceborne Thermal Emission and Reflection Radiometer Global Digital Elevation Model (ASTER GDEM) version2 1-arc-second (~30 m) data; and (iii) the 9-arc-second national GEODATA DEM-9S ver3 from Geoscience Australia and the Australian National University. We used ESRI's geospatial data model, Arc Hydro and HEC-GeoHMS, designed for building hydrologic information systems to synthesize geospatial and temporal water resources data that support hydrologic modeling and analysis. A coastal catchment in northeast Australia was selected as the study site where very high resolution LiDAR data are available for parts of the area as reference data to assess the accuracy of other lower resolution datasets. This study provides morphometric information for drainage basins as part of the broad research on sediment flux from coastal basins to Great Barrier Reef, Australia. After applying geo-referencing and elevation corrections, stream and sub basins were delineated for each DEM. Then physical characteristics for streams (i.e., length, upstream and downstream elevation, and slope) and sub-basins (i.e., longest flow lengths, area, relief and slopes) were extracted and compared with reference datasets from LiDAR. Results showed that, in the absence of high-precision and high resolution DEM data, ASTER GDEM or SRTM DEM can be used to extract common morphometric relationship which are widely used for hydrological and geomorphological modelling.

Online, On Demand Access to Coastal Digital Elevation Models

NASA Astrophysics Data System (ADS)

Long, J.; Bristol, S.; Long, D.; Thompson, S.

2014-12-01

Process-based numerical models for coastal waves, water levels, and sediment transport are initialized with digital elevation models (DEM) constructed by interpolating and merging bathymetric and topographic elevation data. These gridded surfaces must seamlessly span the land-water interface and may cover large regions where the individual raw data sources are collected at widely different spatial and temporal resolutions. In addition, the datasets are collected from different instrument platforms with varying accuracy and may or may not overlap in coverage. The lack of available tools and difficulties in constructing these DEMs lead scientists to 1) rely on previously merged, outdated, or over-smoothed DEMs; 2) discard more recent data that covers only a portion of the DEM domain; and 3) use inconsistent methodologies to generate DEMs. The objective of this work is to address the immediate need of integrating land and water-based elevation data sources and streamline the generation of a seamless data surface that spans the terrestrial-marine boundary. To achieve this, the U.S. Geological Survey (USGS) is developing a web processing service to format and initialize geoprocessing tasks designed to create coastal DEMs. The web processing service is maintained within the USGS ScienceBase data management system and has an associated user interface. Through the map-based interface, users define a geographic region that identifies the bounds of the desired DEM and a time period of interest. This initiates a query for elevation datasets within federal science agency data repositories. A geoprocessing service is then triggered to interpolate, merge, and smooth the data sources creating a DEM based on user-defined configuration parameters. Uncertainty and error estimates for the DEM are also returned by the geoprocessing service. Upon completion, the information management platform provides access to the final gridded data derivative and saves the configuration parameters for future reference. The resulting products and tools developed here could be adapted to future data sources and projects beyond the coastal environment.

ICESat laser altimetry over small mountain glaciers

NASA Astrophysics Data System (ADS)

Treichler, Désirée; Kääb, Andreas

2016-09-01

Using sparsely glaciated southern Norway as a case study, we assess the potential and limitations of ICESat laser altimetry for analysing regional glacier elevation change in rough mountain terrain. Differences between ICESat GLAS elevations and reference elevation data are plotted over time to derive a glacier surface elevation trend for the ICESat acquisition period 2003-2008. We find spatially varying biases between ICESat and three tested digital elevation models (DEMs): the Norwegian national DEM, SRTM DEM, and a high-resolution lidar DEM. For regional glacier elevation change, the spatial inconsistency of reference DEMs - a result of spatio-temporal merging - has the potential to significantly affect or dilute trends. Elevation uncertainties of all three tested DEMs exceed ICESat elevation uncertainty by an order of magnitude, and are thus limiting the accuracy of the method, rather than ICESat uncertainty. ICESat matches glacier size distribution of the study area well and measures small ice patches not commonly monitored in situ. The sample is large enough for spatial and thematic subsetting. Vertical offsets to ICESat elevations vary for different glaciers in southern Norway due to spatially inconsistent reference DEM age. We introduce a per-glacier correction that removes these spatially varying offsets, and considerably increases trend significance. Only after application of this correction do individual campaigns fit observed in situ glacier mass balance. Our correction also has the potential to improve glacier trend significance for other causes of spatially varying vertical offsets, for instance due to radar penetration into ice and snow for the SRTM DEM or as a consequence of mosaicking and merging that is common for national or global DEMs. After correction of reference elevation bias, we find that ICESat provides a robust and realistic estimate of a moderately negative glacier mass balance of around -0.36 ± 0.07 m ice per year. This regional estimate agrees well with the heterogeneous but overall negative in situ glacier mass balance observed in the area.

Extraction and Validation of Geomorphological Features from EU-DEM in The Vicinity of the Mygdonia Basin, Northern Greece

NASA Astrophysics Data System (ADS)

Mouratidis, Antonios; Karadimou, Georgia; Ampatzidis, Dimitrios

2017-12-01

The European Union Digital Elevation Model (EU-DEM) is a relatively new, hybrid elevation product, principally based on SRTM DEM and ASTER GDEM data, but also on publically available Russian topographic maps for regions north of 60° N. More specifically, EU-DEM is a Digital Surface Model (DSM) over Europe from the Global Monitoring for Environment and Security (GMES) Reference Data Access (RDA) project - a realisation of the Copernicus (former GMES) programme, managed by the European Commission/DG Enterprise and Industry. Even if EU-DEM is indeed more reliable in terms of elevation accuracy than its constituents, it ought to be noted that it is not representative of the original elevation measurements, but is rather a secondary (mathematical) product. Therefore, for specific applications, such as those of geomorphological interest, artefacts may be induced. To this end, the purpose of this paper is to investigate the performance of EU-DEM for geomorphological applications and compare it against other available datasets, i.e. topographic maps and (almost) global DEMs such as SRTM, ASTER-GDEM and WorldDEM™. This initial investigation is carried out in Central Macedonia, Northern Greece, in the vicinity of the Mygdonia basin, which corresponds to an area of particular interest for several geoscience applications. This area has also been serving as a test site for the systematic validation of DEMs for more than a decade. Consequently, extensive elevation datasets and experience have been accumulated over the years, rendering the evaluation of new elevation products a coherent and useful exercise on a local to regional scale. In this context, relief classification, drainage basin delineation, slope and slope aspect, as well as extraction and classification of drainage network are performed and validated among the aforementioned elevation sources. The achieved results focus on qualitative and quantitative aspects of automatic geomorphological feature extraction from EU-DEM at a water basin level, with the use of Geographical Information Systems (GIS).

Release of a 10-m-resolution DEM for the whole Italian territory: a new, freely available resource for research purposes

NASA Astrophysics Data System (ADS)

Tarquini, S.; Nannipieri, L.; Favalli, M.; Fornaciai, A.; Vinci, S.; Doumaz, F.

2012-04-01

Digital elevation models (DEMs) are fundamental in any kind of environmental or morphological study. DEMs are obtained from a variety of sources and generated in several ways. Nowadays, a few global-coverage elevation datasets are available for free (e.g., SRTM, http://www.jpl.nasa.gov/srtm; ASTER, http://asterweb.jpl.nasa.gov/). When the matrix of a DEM is used also for computational purposes, the choice of the elevation dataset which better suits the target of the study is crucial. Recently, the increasing use of DEM-based numerical simulation tools (e.g. for gravity driven mass flows), would largely benefit from the use of a higher resolution/higher accuracy topography than those available at planetary scale. Similar elevation datasets are neither easily nor freely available for all countries worldwide. Here we introduce a new web resource which made available for free (for research purposes only) a 10 m-resolution DEM for the whole Italian territory. The creation of this elevation dataset was presented by Tarquini et al. (2007). This DEM was obtained in triangular irregular network (TIN) format starting from heterogeneous vector datasets, mostly consisting in elevation contour lines and elevation points derived from several sources. The input vector database was carefully cleaned up to obtain an improved seamless TIN refined by using the DEST algorithm, thus improving the Delaunay tessellation. The whole TINITALY/01 DEM was converted in grid format (10-m cell size) according to a tiled structure composed of 193, 50-km side square elements. The grid database consists of more than 3 billions of cells and occupies almost 12 GB of disk memory. A web-GIS has been created (http://tinitaly.pi.ingv.it/ ) where a seamless layer of images in full resolution (10 m) obtained from the whole DEM (both in color-shaded and anaglyph mode) is open for browsing. Accredited navigators are allowed to download the elevation dataset.

Knocking down mitochondrial iron transporter (MIT) reprograms primary and secondary metabolism in rice plants

PubMed Central

Vigani, Gianpiero; Bashir, Khurram; Ishimaru, Yasuhiro; Lehmann, Martin; Casiraghi, Fabio Marco; Nakanishi, Hiromi; Seki, Motoaki; Geigenberger, Peter; Zocchi, Graziano; Nishizawa, Naoko K.

2016-01-01

Iron (Fe) is an essential micronutrient for plant growth and development, and its reduced bioavailability strongly impairs mitochondrial functionality. In this work, the metabolic adjustment in the rice (Oryza sativa) mitochondrial Fe transporter knockdown mutant (mit-2) was analysed. Biochemical characterization of purified mitochondria from rice roots showed alteration in the respiratory chain of mit-2 compared with wild-type (WT) plants. In particular, proteins belonging to the type II alternative NAD(P)H dehydrogenases accumulated strongly in mit-2 plants, indicating that alternative pathways were activated to keep the respiratory chain working. Additionally, large-scale changes in the transcriptome and metabolome were observed in mit-2 rice plants. In particular, a strong alteration (up-/down-regulation) in the expression of genes encoding enzymes of both primary and secondary metabolism was found in mutant plants. This was reflected by changes in the metabolic profiles in both roots and shoots of mit-2 plants. Significant alterations in the levels of amino acids belonging to the aspartic acid-related pathways (aspartic acid, lysine, and threonine in roots, and aspartic acid and ornithine in shoots) were found that are strictly connected to the Krebs cycle. Furthermore, some metabolites (e.g. pyruvic acid, fumaric acid, ornithine, and oligosaccharides of the raffinose family) accumulated only in the shoot of mit-2 plants, indicating possible hypoxic responses. These findings suggest that the induction of local Fe deficiency in the mitochondrial compartment of mit-2 plants differentially affects the transcript as well as the metabolic profiles in root and shoot tissues. PMID:26685186

Glacier Volume Change Estimation Using Time Series of Improved Aster Dems

NASA Astrophysics Data System (ADS)

Girod, Luc; Nuth, Christopher; Kääb, Andreas

2016-06-01

Volume change data is critical to the understanding of glacier response to climate change. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) system embarked on the Terra (EOS AM-1) satellite has been a unique source of systematic stereoscopic images covering the whole globe at 15m resolution and at a consistent quality for over 15 years. While satellite stereo sensors with significantly improved radiometric and spatial resolution are available to date, the potential of ASTER data lies in its long consistent time series that is unrivaled, though not fully exploited for change analysis due to lack of data accuracy and precision. Here, we developed an improved method for ASTER DEM generation and implemented it in the open source photogrammetric library and software suite MicMac. The method relies on the computation of a rational polynomial coefficients (RPC) model and the detection and correction of cross-track sensor jitter in order to compute DEMs. ASTER data are strongly affected by attitude jitter, mainly of approximately 4 km and 30 km wavelength, and improving the generation of ASTER DEMs requires removal of this effect. Our sensor modeling does not require ground control points and allows thus potentially for the automatic processing of large data volumes. As a proof of concept, we chose a set of glaciers with reference DEMs available to assess the quality of our measurements. We use time series of ASTER scenes from which we extracted DEMs with a ground sampling distance of 15m. Our method directly measures and accounts for the cross-track component of jitter so that the resulting DEMs are not contaminated by this process. Since the along-track component of jitter has the same direction as the stereo parallaxes, the two cannot be separated and the elevations extracted are thus contaminated by along-track jitter. Initial tests reveal no clear relation between the cross-track and along-track components so that the latter seems not to be easily modeled analytically from the first one. We thus remove the remaining along-track jitter effects in the DEMs statistically through temporal DEM stacks to finally compute the glacier volume changes over time. Our method yields cleaner and spatially more complete elevation data, which also proved to be more in accordance to reference DEMs, compared to NASA's AST14DMO DEM standard products. The quality of the demonstrated measurements promises to further unlock the underused potential of ASTER DEMs for glacier volume change time series on a global scale. The data produced by our method will help to better understand the response of glaciers to climate change and their influence on runoff and sea level.

NASA Chief Technologist Speaks at Massachusetts Institute of Technology

NASA Image and Video Library

2018-02-15

NASA Chief Technologist Douglas Terrier joined students, faculty and experts in Boston as part of MIT's "Better MIT Innovation Week 2018," a week-long program promoting leadership, entrepreneurship and action for a better future. During the February event, Terrier spoke about a culture of innovation at America's Space Program. (Photo: Damian Barabonkov/MIT Technique)

Scratch that: MIT's Mitchel Resnick Says Kids Should Do It for Themselves

ERIC Educational Resources Information Center

Traylor, Scott

2008-01-01

Mitchel Resnick is a researcher, inventor, and professor at MIT's Media Laboratory in Cambridge, MA, and the founder of the Lifelong Kindergarten Group at MIT. He is the lead innovator behind many cutting-edge learning technologies and projects for children, including the Computer Clubhouse, PicoCrickets, and the wildly successful consumer…

Mobile-IT Education (MIT.EDU): M-Learning Applications for Classroom Settings

ERIC Educational Resources Information Center

Sung, M.; Gips, J.; Eagle, N.; Madan, A.; Caneel, R.; DeVaul, R.; Bonsen, J.; Pentland, A.

2005-01-01

In this paper, we describe the Mobile-IT Education (MIT.EDU) system, which demonstrates the potential of using a distributed mobile device architecture for rapid prototyping of wireless mobile multi-user applications for use in classroom settings. MIT.EDU is a stable, accessible system that combines inexpensive, commodity hardware, a flexible…

Coming to Terms with MOOCs: A Community College Angle

ERIC Educational Resources Information Center

Fifield, Mary L.

2013-01-01

When MIT approached Bunker Hill Community College (BHCC) to participate in edX, the new Harvard/MIT massive open online course (MOOC) initiative, the administrators reacted with both interest and skepticism. What did MIT have in mind for Bunker Hill Community College? Today at BHCC, the establishment of "Learning Communities" transforms…

MND2: A new mouse model of inherited motor neuron disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, J.M.; Albin, R.L.; Feldman, E.L.

1993-06-01

The autosomal recessive mutation mnd2 results in early onset motor neuron disease with rapidly progressive paralysis, severe muscle wasting, regression of thymus and spleen, and death before 40 days of age. mnd2 has been mapped to mouse chromosome 6 with the gene order: centromere-Tcrb-Ly-2-Sftp-3-D6Mit4-mnd2-D6Mit6, D6Mit9-D6Rck132-Raf-1, D6Mit11-D6Mit12-D6Mit14. mnd2 is located within a conserved linkage group with homologs on human chromosome 2p12-p13. Spinal motor neurons of homozygous affected animals are swollen and stain weakly, and electromyography revealed spontaneous activity characteristic of muscle denervation. Myelin staining was normal throughout the neuraxis. The clinical observations are consistent with a primary abnormality of lower motormore » neuron function. This new animal model will be of value for identification of a genetic defect responsible for motor neuron disease and for evaluation of new therapies. 36 refs., 7 figs., 2 tabs.« less

The developmental eye movement (DEM) test and Cantonese-speaking children in Hong Kong SAR, China.

PubMed

Pang, Peter C; Lam, Carly S; Woo, George C

2010-07-01

There is no published norm for the Developmental Eye Movement (DEM) Test for Cantonese-speaking Chinese children. This study aimed to determine the normative values of this test for Cantonese-speaking Chinese children in Hong Kong SAR and to compare the results with the published norms of English-speaking and Spanish-speaking children. Cantonese-speaking students aged from 6 to 11 years were tested by the DEM test in Cantonese and a digital recorder was used to record the process. The DEM scores for the 305 students were determined by listening again to the audio records after the test and computed by using the formula from the DEM manual, except that the 'vertical scores' were adjusted by taking the vertical errors into consideration. The results were compared with other norms that have been published. Our subjects made more vertical errors than in other normative studies and adjusted vertical scores were proposed. In both adjusted vertical and horizontal scores, the Cantonese-speaking children completed the tests much faster than the norms for English- and Spanish-speaking children, the differences of the means being significant (p < 0.0001) in all age groups. The DEM norms may be affected by differences in languages, cultures and education systems among different ethnicities. The norms of the DEM test are proposed for Cantonese-speaking children in Hong Kong SAR, China.

The Discrepancy Evaluation Model: A Systematic Approach for the Evaluation of Career Planning and Placement Programs.

ERIC Educational Resources Information Center

Buttram, Joan L.; Covert, Robert W.

The Discrepancy Evaluation Model (DEM), developed in 1966 by Malcolm Provus, provides information for program assessment and program improvement. Under the DEM, evaluation is defined as the comparison of an actual performance to a desired standard. The DEM embodies five stages of evaluation based upon a program's natural development: program…

Comparison of digital elevation models for aquatic data development.

Treesearch

Sharon Clarke; Kelly Burnett

2003-01-01

Thirty-meter digital elevation models (DEMs) produced by the U.S. Geological Survey (USGS) are widely available and commonly used in analyzing aquatic systems. However, these DEMs are of relatively coarse resolution, were inconsistently produced (i.e., Level 1 versus Level 2 DEMs), and lack drainage enforcement. Such issues may hamper efforts to accurately model...

Tropical-forest biomass estimation at X-Band from the spaceborne TanDEM-X interferometer

Treesearch

R. Treuhaft; F. Goncalves; J.R. dos Santos; M. Keller; M. Palace; S.N. Madsen; F. Sullivan; P.M.L.A. Graca

2014-01-01

This letter reports the sensitivity of X-band interferometric synthetic aperture radar (InSAR) data from the first dual-spacecraft radar interferometer, TanDEM-X, to variations in tropical-forest aboveground biomass (AGB). It also reports the first tropical-forest AGB estimates fromTanDEM-X data. Tropical forests account for...

Digital Transformation Canvas - Übersicht behalten und Handlungsfelder gestalten

NASA Astrophysics Data System (ADS)

Köster, Michael; Mache, Tobias

Im Beitrag "Digital Transformation Canvas - Übersicht behalten und Handlungsfelder gestalten" wird zunächst grob auf die wesentlichen Herausforderungen, die mit der zunehmenden Digitalisierung einhergehen, eingegangen. Anschließend werden ausgewählte Konzepte des Business Transformation Management vorgestellt, die sich mit der grundlegenden Weiterentwicklung von Organisationen - wie es die Digitalisierung erfordert - auseinandersetzen. Eine detaillierte Einführung in die Methodik des Business Transformation Canvas, der sich mit den unterschiedlichsten Gestaltungsfeldern der Transformation auseinandersetzt und ein Framework für Transformationsprojekte darstellt, rundet den Beitrag ab. Er schließt mit einem Fazit und Ausblick.

Accuracy improvement of the ice flow rate measurements on Antarctic ice sheet by DInSAR method

NASA Astrophysics Data System (ADS)

Shiramizu, Kaoru; Doi, Koichiro; Aoyama, Yuichi

2015-04-01

DInSAR (Differential Interferometric Synthetic Aperture Radar) is an effective tool to measure the flow rate of slow flowing ice streams on Antarctic ice sheet with high resolution. In the flow rate measurement by DInSAR method, we use Digital Elevation Model (DEM) at two times in the estimating process. At first, we use it to remove topographic fringes from InSAR images. And then, it is used to project obtained displacements along Line-Of-Sight (LOS) direction to the actual flow direction. ASTER-GDEM widely-used for InSAR prosessing of the data of polar region has a lot of errors especially in the inland ice sheet area. Thus the errors yield irregular flow rates and directions. Therefore, quality of DEM has a substantial influence on the ice flow rate measurement. In this study, we created a new DEM (resolution 10m; hereinafter referred to as PRISM-DEM) based on ALOS/PRISM images, and compared PRISM-DEM and ASTER-GDEM. The study area is around Skallen, 90km south from Syowa Station, in the southern part of Sôya Coast, East Antarctica. For making DInSAR images, we used ALOS/PALSAR data of 13 pairs (Path633, Row 571-572), observed during the period from November 23, 2007 through January 16, 2011. PRISM-DEM covering the PALSAR scene was created from nadir and backward view images of ALOS/PRISM (Observation date: 2009/1/18) by applying stereo processing with a digital mapping equipment, and then the automatically created a primary DEM was corrected manually to make a final DEM. The number of irregular values of actual ice flow rate was reduced by applying PRISM-DEM compared with that by applying ASTER-GDEM. Additionally, an averaged displacement of approximately 0.5cm was obtained by applying PRISM-DEM over outcrop area, where no crustal displacement considered to occur during the recurrence period of ALOS/PALSAR (46days), while an averaged displacement of approximately 1.65 cm was observed by applying ASTER-GDEM. Since displacements over outcrop area are considered to be apparent ones, the average could be a measure of flow rate estimation accuracy by DInSAR. Therefore, it is concluded that the accuracy of the ice flow rate measurement can be improved by using PRISM-DEM. In this presentation, we will show the results of the estimated flow rate of ice streams in the region of interest, and discuss the additional accuracy improvement of this method.

Factors affecting accuracy in the Developmental Eye Movement Test measurement for Cantonese-speaking children.

PubMed

Pang, Peter C; Lam, Carly S; Woo, George C

2010-09-01

This study aims to determine the factors affecting the accuracy in the Developmental Eye Movement (DEM) test measurement for Cantonese-speaking children. The voices of 10 Cantonese-speaking children (aged between six and eight years) undertaking the vertical test (40 numbers) of the DEM test were recorded on a digital audio recorder. These voice clips were assessed by an experienced examiner to give the DEM test times. The examiner repeated the measurement five times for each voice clip and completed all 10 voice clips from the 10 children. The average of a single measurement, the mean of two, the mean of three and the mean of five repeated measurements were then compared. Five experienced and five inexperienced examiners of the DEM test were asked to record the results from five Cantonese-speaking children by listening to the playback of prerecorded audio clips. The deviation of the results from the preset values between the two groups was compared. There is no difference between the single measurement and those obtained by mean of two, three, four or five. Both experienced and inexperienced examiners obtained a higher deviation from the preset values in the adjusted compared with the non-adjusted times in both vertical and horizontal times. Experienced examiners measured the vertical times and adjusted vertical times significantly closer to the preset values than the inexperienced examiners (paired t-test, p < 0.05). The DEM test needs to be measured only once for an accurate time measurement. Inaccurate assessment of 'reading errors' in the DEM test can increase the inaccuracy of the adjusted times. It is suggested that an audio recording of the test be made to allow reassessment of reading errors. Experience in using the DEM test yields a more accurate DEM measurement as errors are detected more easily.

The impact of high-resolution topography on landslide characterization using DInSAR

NASA Astrophysics Data System (ADS)

Tiampo, K. F.; Barba, M.; Jacquemart, M. F.; Willis, M. J.; González, P. J.; McKee, C.; Samsonov, S. V.; Feng, W.

2017-12-01

Differential interferometric synthetic aperture radar (DInSAR) can measure surface deformation at the centimeter level and, as a result, has been used to investigate a wide variety of natural hazards since the 1990s. In general, short spatial and temporal baselines are selected to reduce decorrelation and the effect of incorrect removal of the topographic component in differential interferograms. The nearly global coverage of the Shuttle Radar Topography Mission (SRTM) digital elevation models (DEMs) significantly simplified and improved the modelling and removal of topography for differential interferometric applications. However, DEMs are produced today at much finer resolutions, although with varying availability and cost. SRTM DEMs are freely available at 30 m resolution world-wide and 10 m resolution in the US. The TanDEM-X mission has produced a worldwide DEM at 12 m, although it is not generally free of cost. Light Detection and Ranging (LiDAR) DEMs can provide better than 1m resolution, but are expensive to produce over limited extents. Finally, DEMs from optical data can be produced from Digital Globe satellite images over larger regions at resolutions of less than 1 m, subject to various restrictions. It can be shown that the coherence quality of a DInSAR image is directly related to the DEM resolution, improving recovery of the differential phase by significantly reducing the geometric decorrelation, and that the number of recovered pixels significantly increases with higher resolutions, particularly in steep topography. In this work we quantify that improvement for varying resolutions, from 1 to 30 m, and slopes and investigate its effect on the characterization of landslides in different regions and with a variety of surface conditions, including Greenland, Alaska, California, and the Canary Islands.

NASADEM Initial Production Processing Results: Shuttle Radar Topography Mission (SRTM) Reprocessing with Improvements

NASA Astrophysics Data System (ADS)

Buckley, S.; Agram, P. S.; Belz, J. E.; Crippen, R. E.; Gurrola, E. M.; Hensley, S.; Kobrick, M.; Lavalle, M.; Martin, J. M.; Neumann, M.; Nguyen, Q.; Rosen, P. A.; Shimada, J.; Simard, M.; Tung, W.

2016-12-01

NASADEM is a significant modernization of SRTM digital elevation model (DEM) data supported by the NASA MEaSUREs program. We are reprocessing the raw radar signal data using improved algorithms and incorporating ICESat and DEM data unavailable during the original processing. The NASADEM products will be freely-available through the Land Processes Distributed Active Archive Center (LPDAAC) at one-arcsecond spacing and delivered by continent: North America, South America, Australia, Eurasia, Africa, and Island Groups. We are in the production phase of the project. This involves radar interferometry (InSAR) processing on thousands of radar datatakes. New phase unwrapping and height ripple error correction (HREC) procedures are applied to the data. The resulting strip DEMs and ancillary information are passed to a back-end processor to create DEM mosaics and new geocoded single-swath products. Manual data quality assessment (QA) and fixes are performed at several steps in the processing chain. Post-production DEM void-filling is described in a companion AGU Fall Meeting presentation. The team completed the InSAR processing for all continents and the manual QA of the strip DEMs for more than half the world. North America strip DEM void areas are reduced by more than 50%. The ICESat data is used for height ripple error correction and as control for continent-scale adjustment of the strip DEMs. These ripples are due to uncompensated mast motion most pronounced after Shuttle roll angle adjustment maneuvers. After an initial assessment of the NASADEM production processing for the Americas, we further refined the selection of ICESat data for control by excluded data over glaciers, snow cover, forest clear cuts, and sloped areas. The HREC algorithm reduces the North America ICESat-SRTM bias from 80 cm to 3 cm and the RMS from 5m to 4m.

Comparison and Analysis of Accuracy of Elevation Extraction Based on the ZY-3 01 and 02 Satellites Stereoscopic Images

NASA Astrophysics Data System (ADS)

Zhao, L.; Fu, X.; Dou, X.; Liu, H.; Fang, Z.

2018-04-01

The ZY-3 is the civil high-resolution optical stereoscopic mapping satellite independently developed by China. The ZY-3 constellation of the twin satellites operates in a sun-synchronous, near-polar, circular 505 km orbit, with a descending location time of 10:30 AM and a 29-day revisiting period. The panchromatic triplet sensors, pointing forward, nadir, and backward with an angle of 22°, have excellent base-to-height ratio, which is beneficial to the extraction of DEM. In order to extract more detailed and highprecision DEM, the ZY-3 (02) satellite has been upgraded based on the ZY-3 (01), and the GSD of the stereo camera has been optimized from 3.5 to 2.5 meters. In the paper case studies using the ZY-3 01 and the 02 satellite data for block adjustment and DEM extraction have been carried out in Liaoning Province of China. The results show that the planimetric and altimetric accuracy can reach 3 meters, which meet the mapping requirements of 1 : 50,000 national topographic map and the design performance of the satellites. The normalized elevation accuracy index (NEAI) is adopted to evaluate the twin satellite stereoscopic performance, and the NEAIs of the twin ZY-3 satellites are good and the index of the ZY-3(02) is slightly better. The comparison of the overlapping DEMs from the twin ZY-3 satellites and SRTM is analysed. The bias and the standard deviation of all the DEMs are better than 5 meters. In addition, in the process of accuracy comparison, some gross errors of the DEM can be identified, and some elevation changes of the DEM can also be found. The differential DEM becomes a new tool and application.

Fine structure of metal-insulator transition in EuO resolved by doping engineering.

PubMed

Averyanov, Dmitry V; Parfenov, Oleg E; Tokmachev, Andrey M; Karateev, Igor A; Kondratev, Oleg A; Taldenkov, Alexander N; Platunov, Mikhail S; Wilhelm, Fabrice; Rogalev, Andrei; Storchak, Vyacheslav G

2018-05-11

Metal-insulator transitions (MITs) offer new functionalities for nanoelectronics. However, ongoing attempts to control the resistivity by external stimuli are hindered by strong coupling of spin, charge, orbital and lattice degrees of freedom. This difficulty presents a quest for materials which exhibit MIT caused by a single degree of freedom. In the archetypal ferromagnetic semiconductor EuO, magnetic orders dominate the MIT. Here we report a new approach to take doping under control in this material on the nanoscale: formation of oxygen vacancies is strongly suppressed to exhibit the highest MIT resistivity jump and magnetoresistance among thin films. The nature of the MIT is revealed in Gd doped films. The critical doping is determined to be more than an order of magnitude lower than in all previous studies. In lightly doped films, a remarkable thermal hysteresis in resistivity is discovered. It extends over 100 K in the paramagnetic phase reaching 3 orders of magnitude. In the warming mode, the MIT is shown to be a two-step process. The resistivity patterns are consistent with an active role of magnetic polarons-formation of a narrow band and its thermal destruction. High-temperature magnetic polaron effects include large negative magnetoresistance and ferromagnetic droplets revealed by x-ray magnetic circular dichroism. Our findings have wide-range implications for the understanding of strongly correlated oxides and establish fundamental benchmarks to guide theoretical models of the MIT.

Fine structure of metal–insulator transition in EuO resolved by doping engineering

NASA Astrophysics Data System (ADS)

Averyanov, Dmitry V.; Parfenov, Oleg E.; Tokmachev, Andrey M.; Karateev, Igor A.; Kondratev, Oleg A.; Taldenkov, Alexander N.; Platunov, Mikhail S.; Wilhelm, Fabrice; Rogalev, Andrei; Storchak, Vyacheslav G.

2018-05-01

Metal–insulator transitions (MITs) offer new functionalities for nanoelectronics. However, ongoing attempts to control the resistivity by external stimuli are hindered by strong coupling of spin, charge, orbital and lattice degrees of freedom. This difficulty presents a quest for materials which exhibit MIT caused by a single degree of freedom. In the archetypal ferromagnetic semiconductor EuO, magnetic orders dominate the MIT. Here we report a new approach to take doping under control in this material on the nanoscale: formation of oxygen vacancies is strongly suppressed to exhibit the highest MIT resistivity jump and magnetoresistance among thin films. The nature of the MIT is revealed in Gd doped films. The critical doping is determined to be more than an order of magnitude lower than in all previous studies. In lightly doped films, a remarkable thermal hysteresis in resistivity is discovered. It extends over 100 K in the paramagnetic phase reaching 3 orders of magnitude. In the warming mode, the MIT is shown to be a two-step process. The resistivity patterns are consistent with an active role of magnetic polarons—formation of a narrow band and its thermal destruction. High-temperature magnetic polaron effects include large negative magnetoresistance and ferromagnetic droplets revealed by x-ray magnetic circular dichroism. Our findings have wide-range implications for the understanding of strongly correlated oxides and establish fundamental benchmarks to guide theoretical models of the MIT.

Polymeric mixed micelles loaded mitoxantrone for overcoming multidrug resistance in breast cancer via photodynamic therapy

PubMed Central

Zhao, Yiqiao; Yu, Hua; Zhou, Haiyu; Chen, Meiwan

2017-01-01

Mitoxantrone (MIT) is an anticancer agent with photosensitive properties that is commonly used in various cancers. Multidrug resistance (MDR) effect has been an obstacle to using MIT for cancer therapy. Photochemical internalization, on account of photodynamic therapy, has been applied to improve the therapeutic effect of cancers with MDR effect. In this study, an MIT-poly(ε-caprolactone)-pluronic F68-poly(ε-caprolactone)/poly(d,l-lactide-co-glycolide)–poly(ethylene glycol)–poly(d,l-lactide-co-glycolide) (MIT-PFP/PPP) mixed micelles system was applied to reverse the effect of MDR in MCF-7/ADR cells via photochemical reaction when exposed to near-infrared light. MIT-PFP/PPP mixed micelles showed effective interaction with near-infrared light at the wavelength of 660 nm and exerted great cytotoxicity in MCF-7/ADR cells with irradiation. Furthermore, MIT-PFP/PPP mixed micelles could improve reactive oxygen species (ROS) levels, decrease P-glycoprotein activity, and increase the cellular uptake of drugs with improved intracellular drug concentrations, which induced cell apoptosis in MCF-7/ADR cells under irradiation, despite MDR effect, as indicated by the increased level of cleaved poly ADP-ribose polymerase. These findings suggested that MIT-PFP/PPP mixed micelles may become a promising strategy to effectively reverse the MDR effect via photodynamic therapy in breast cancer. PMID:28919756

Assessing International Product Design and Development Graduate Courses: The MIT-Portugal Program

ERIC Educational Resources Information Center

Dori, Yehudit Judy; Silva, Arlindo

2010-01-01

The Product Design and Development (PDD) course is part of the graduate curriculum in the Engineering Design and Advanced Manufacturing (EDAM) study in the MIT-Portugal Program. The research participants included about 110 students from MIT, EDAM, and two universities in Portugal, Instituto Superior Técnico-Universidade Técnica de Lisboa (IST) and…

The Fourteenth International Meeting on Time-Resolved Vibrational Spectroscopy (TRVS XIV)

DTIC Science & Technology

2010-02-03

Technology United States ahorning@mit.edu Anne Hudson MIT Dept. of Chemistry United States amh@mit.edu Adriana Huerta Viga University of Amsterdam...Hoffmann, Janos Hebling, Harold Y. Hwang, THz-pump/THz-probe nonlinear spectroscopy Ka -Lo Yeh, Keith A. Nelson, MIT 11:30 AM C Tomonori Nomoto and

The OpenCourseWare Story: New England Roots, Global Reach

ERIC Educational Resources Information Center

Carson, Stephen

2008-01-01

The OpenCourseWare movement has its roots in New England. The concept emerged in 2000 at Massachusetts Institute of Technology (MIT) where then-President Charles Vest charged a faculty committee with answering two questions: "How is the Internet going to change education?" and "What should MIT do about it?" MIT moved quickly to…

Prospective pilot trial of PerMIT versus standard anticoagulation service management of patients initiating oral anticoagulation.

PubMed

Borgman, Mark P; Pendleton, Robert C; McMillin, Gwendolyn A; Reynolds, Kristen K; Vazquez, Sara; Freeman, Andrew; Wilson, Andrew; Valdes, Roland; Linder, Mark W

2012-09-01

We performed a randomised pilot trial of PerMIT, a novel decision support tool for genotype-based warfarin initiation and maintenance dosing, to assess its efficacy for improving warfarin management. We prospectively studied 26 subjects to compare PerMIT-guided management with routine anticoagulation service management. CYP2C9 and VKORC1 genotype results for 13 subjects randomly assigned to the PerMIT arm were recorded within 24 hours of enrolment. To aid in INR interpretation, PerMIT calculates estimated loading and maintenance doses based on a patient's genetic and clinical characteristics and displays calculated S-warfarin plasma concentrations based on planned or administered dosages. In comparison to control subjects, patients in the PerMIT study arm demonstrated a 3.6-day decrease in the time to reach a stabilised INR within the target therapeutic range (4.7 vs. 8.3 days, p = 0.015); a 12.8% increase in time spent within the therapeutic interval over the first 25 days of therapy (64.3% vs. 55.3%, p = 0.180); and a 32.9% decrease in the frequency of warfarin dose adjustments per INR measurement (38.3% vs. 57.1%, p = 0.007). Serial measurements of plasma S-warfarin concentrations were also obtained to prospectively evaluate the accuracy of the pharmacokinetic model during induction therapy. The PerMIT S-warfarin plasma concentration model estimated 62.8% of concentrations within 0.15 mg/l. These pilot data suggest that the PerMIT method and its incorporation of genotype/phenotype information may help practitioners increase the safety, efficacy, and efficiency of warfarin therapeutic management.

Knocking down mitochondrial iron transporter (MIT) reprograms primary and secondary metabolism in rice plants.

PubMed

Vigani, Gianpiero; Bashir, Khurram; Ishimaru, Yasuhiro; Lehmann, Martin; Casiraghi, Fabio Marco; Nakanishi, Hiromi; Seki, Motoaki; Geigenberger, Peter; Zocchi, Graziano; Nishizawa, Naoko K

2016-03-01

Iron (Fe) is an essential micronutrient for plant growth and development, and its reduced bioavailability strongly impairs mitochondrial functionality. In this work, the metabolic adjustment in the rice (Oryza sativa) mitochondrial Fe transporter knockdown mutant (mit-2) was analysed. Biochemical characterization of purified mitochondria from rice roots showed alteration in the respiratory chain of mit-2 compared with wild-type (WT) plants. In particular, proteins belonging to the type II alternative NAD(P)H dehydrogenases accumulated strongly in mit-2 plants, indicating that alternative pathways were activated to keep the respiratory chain working. Additionally, large-scale changes in the transcriptome and metabolome were observed in mit-2 rice plants. In particular, a strong alteration (up-/down-regulation) in the expression of genes encoding enzymes of both primary and secondary metabolism was found in mutant plants. This was reflected by changes in the metabolic profiles in both roots and shoots of mit-2 plants. Significant alterations in the levels of amino acids belonging to the aspartic acid-related pathways (aspartic acid, lysine, and threonine in roots, and aspartic acid and ornithine in shoots) were found that are strictly connected to the Krebs cycle. Furthermore, some metabolites (e.g. pyruvic acid, fumaric acid, ornithine, and oligosaccharides of the raffinose family) accumulated only in the shoot of mit-2 plants, indicating possible hypoxic responses. These findings suggest that the induction of local Fe deficiency in the mitochondrial compartment of mit-2 plants differentially affects the transcript as well as the metabolic profiles in root and shoot tissues. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Mechanisms of spin-flipping and metal-insulator transition in nano-Fe3O4

NASA Astrophysics Data System (ADS)

Dito Fauzi, Angga; Aziz Majidi, Muhammad; Rusydi, Andrivo

2017-04-01

Fe3O4 is a half-metallic ferrimagnet with {{T}\\text{C}}˜ 860 K exhibiting metal-insulator transition (MIT) at  ˜120 K. In bulk form, the saturation magnetization is 0.6 Tesla (˜471 emu cm-3). A recent experimental study has shown that the saturation magnetization of nano-Fe3O4 thin films can achieve up to  ˜760 emu cm-3, attributed to spin-flipping of Fe ions at tetrahedral sites assisted by oxygen vacancies (V O). Such a system has shown to have higher MIT temperature (˜150 K). The spin-flipping is a new phenomenon in Fe3O4, while the MIT is a long-standing one. Here, we propose a model and calculations to investigate the mechanisms of both phenomena. Our results show that, for the system without V O, the ferrimagnetic configuration is energetically favorable. Remakably, upon inclusion of V O, the ground-state configuration switches into ferromagnetic. As for the MIT, by proposing temperature dependences of some hopping integrals in the model, we demonstrate that the system without and with V O undergo the MIT in slightly different ways, leading to higher MIT temperature for the system with V O, in agreement with the experimental data. Our results also show that the MIT in both systems occur concomitantly with the redistribution of electrons among the three Fe ions in each Fe3O4 formula unit. As such temperature dependences of hopping integrals may arise due to dynamic Jahn-Teller effects, our phenomenological theory may provide a way to reconcile existing theories relating the MIT to the structural transition and the charge ordering.

Using FastX on the Peregrine System | High-Performance Computing | NREL

Science.gov Websites

with full 3D hardware acceleration. The traditional method of displaying graphics applications to a remote X server (indirect rendering) supports 3D hardware acceleration, but this approach causes all of the OpenGL commands and 3D data to be sent over the network to be rendered on the client machine. With

Dem Generation from Close-Range Photogrammetry Using Extended Python Photogrammetry Toolbox

NASA Astrophysics Data System (ADS)

Belmonte, A. A.; Biong, M. M. P.; Macatulad, E. G.

2017-10-01

Digital elevation models (DEMs) are widely used raster data for different applications concerning terrain, such as for flood modelling, viewshed analysis, mining, land development, engineering design projects, to name a few. DEMs can be obtained through various methods, including topographic survey, LiDAR or photogrammetry, and internet sources. Terrestrial close-range photogrammetry is one of the alternative methods to produce DEMs through the processing of images using photogrammetry software. There are already powerful photogrammetry software that are commercially-available and can produce high-accuracy DEMs. However, this entails corresponding cost. Although, some of these software have free or demo trials, these trials have limits in their usable features and usage time. One alternative is the use of free and open-source software (FOSS), such as the Python Photogrammetry Toolbox (PPT), which provides an interface for performing photogrammetric processes implemented through python script. For relatively small areas such as in mining or construction excavation, a relatively inexpensive, fast and accurate method would be advantageous. In this study, PPT was used to generate 3D point cloud data from images of an open pit excavation. The PPT was extended to add an algorithm converting the generated point cloud data into a usable DEM.

The sensitivity of catchment hypsometry and hypsometric properties to DEM resolution and polynomial order

NASA Astrophysics Data System (ADS)

Liffner, Joel W.; Hewa, Guna A.; Peel, Murray C.

2018-05-01

Derivation of the hypsometric curve of a catchment, and properties relating to that curve, requires both use of topographical data (commonly in the form of a Digital Elevation Model - DEM), and the estimation of a functional representation of that curve. An early investigation into catchment hypsometry concluded 3rd order polynomials sufficiently describe the hypsometric curve, without the consideration of higher order polynomials, or the sensitivity of hypsometric properties relating to the curve. Another study concluded the hypsometric integral (HI) is robust against changes in DEM resolution, a conclusion drawn from a very limited sample size. Conclusions from these earlier studies have resulted in the adoption of methods deemed to be "sufficient" in subsequent studies, in addition to assumptions that the robustness of the HI extends to other hypsometric properties. This study investigates and demonstrates the sensitivity of hypsometric properties to DEM resolution, DEM type and polynomial order through assessing differences in hypsometric properties derived from 417 catchments and sub-catchments within South Australia. The sensitivity of hypsometric properties across DEM types and polynomial orders is found to be significant, which suggests careful consideration of the methods chosen to derive catchment hypsometric information is required.

An Alternative Approach of Coastal Sea-Level Observation from Remote Sensing Imageries

NASA Astrophysics Data System (ADS)

Peng, H. Y.; Tseng, K. H.; Chung-Yen, K.; Lin, T. H.; Liao, W. H.; Chen, C. F.

2017-12-01

Coastal sea level can be observed as waterline changes along a coastal digital elevation model (DEM). However, most global DEMs, such as the Shuttle Radar Topography Mission (SRTM) DEM with 30 m resolution, provide limited coverage over coastal area due to the impermeability of radar signal over water and the lack of low-tide coincidence. Therefore, we aim to extend to coverage of SRTM DEM for the determination of intertidal zone and to monitor sea-level changes along the entire coastline of Taiwan (>1200km). We firstly collect historical cloud-free images since the 1980s, including Landsat series, SPOT series and Sentinel-2, and then calculate the Modified Normalized Difference Water Index (MNDWI) to identify water pixels. After computing water appearance probability of each pixel, it is converted into actual elevation by introducing the DTU10 tide model for high tide and low tide boundaries. A coastal DEM of intertidal zone is reconstructed and the accuracy is at 50 cm level as compared with in situ DEM built by an unmanned aerial vehicle (UAV). Finally, we use this product to define the up-to-date intertidal zone and estimate sea-level changes by using remote sensing snapshots.

Automatic relative RPC image model bias compensation through hierarchical image matching for improving DEM quality

NASA Astrophysics Data System (ADS)

Noh, Myoung-Jong; Howat, Ian M.

2018-02-01

The quality and efficiency of automated Digital Elevation Model (DEM) extraction from stereoscopic satellite imagery is critically dependent on the accuracy of the sensor model used for co-locating pixels between stereo-pair images. In the absence of ground control or manual tie point selection, errors in the sensor models must be compensated with increased matching search-spaces, increasing both the computation time and the likelihood of spurious matches. Here we present an algorithm for automatically determining and compensating the relative bias in Rational Polynomial Coefficients (RPCs) between stereo-pairs utilizing hierarchical, sub-pixel image matching in object space. We demonstrate the algorithm using a suite of image stereo-pairs from multiple satellites over a range stereo-photogrammetrically challenging polar terrains. Besides providing a validation of the effectiveness of the algorithm for improving DEM quality, experiments with prescribed sensor model errors yield insight into the dependence of DEM characteristics and quality on relative sensor model bias. This algorithm is included in the Surface Extraction through TIN-based Search-space Minimization (SETSM) DEM extraction software package, which is the primary software used for the U.S. National Science Foundation ArcticDEM and Reference Elevation Model of Antarctica (REMA) products.

Bumps in river profiles: uncertainty assessment and smoothing using quantile regression techniques

NASA Astrophysics Data System (ADS)

Schwanghart, Wolfgang; Scherler, Dirk

2017-12-01

The analysis of longitudinal river profiles is an important tool for studying landscape evolution. However, characterizing river profiles based on digital elevation models (DEMs) suffers from errors and artifacts that particularly prevail along valley bottoms. The aim of this study is to characterize uncertainties that arise from the analysis of river profiles derived from different, near-globally available DEMs. We devised new algorithms - quantile carving and the CRS algorithm - that rely on quantile regression to enable hydrological correction and the uncertainty quantification of river profiles. We find that globally available DEMs commonly overestimate river elevations in steep topography. The distributions of elevation errors become increasingly wider and right skewed if adjacent hillslope gradients are steep. Our analysis indicates that the AW3D DEM has the highest precision and lowest bias for the analysis of river profiles in mountainous topography. The new 12 m resolution TanDEM-X DEM has a very low precision, most likely due to the combined effect of steep valley walls and the presence of water surfaces in valley bottoms. Compared to the conventional approaches of carving and filling, we find that our new approach is able to reduce the elevation bias and errors in longitudinal river profiles.

Identification and delineation of areas flood hazard using high accuracy of DEM data

NASA Astrophysics Data System (ADS)

Riadi, B.; Barus, B.; Widiatmaka; Yanuar, M. J. P.; Pramudya, B.

2018-05-01

Flood incidents that often occur in Karawang regency need to be mitigated. These expectations exist on technologies that can predict, anticipate and reduce disaster risks. Flood modeling techniques using Digital Elevation Model (DEM) data can be applied in mitigation activities. High accuracy DEM data used in modeling, will result in better flooding flood models. The result of high accuracy DEM data processing will yield information about surface morphology which can be used to identify indication of flood hazard area. The purpose of this study was to identify and describe flood hazard areas by identifying wetland areas using DEM data and Landsat-8 images. TerraSAR-X high-resolution data is used to detect wetlands from landscapes, while land cover is identified by Landsat image data. The Topography Wetness Index (TWI) method is used to detect and identify wetland areas with basic DEM data, while for land cover analysis using Tasseled Cap Transformation (TCT) method. The result of TWI modeling yields information about potential land of flood. Overlay TWI map with land cover map that produces information that in Karawang regency the most vulnerable areas occur flooding in rice fields. The spatial accuracy of the flood hazard area in this study was 87%.

Digital Elevation Models of the Earth derived from space-based observations: Advances and potential for geomorphological studies

NASA Astrophysics Data System (ADS)

Mouratidis, Antonios

2013-04-01

Digital Elevation Models (DEMs) are an inherently interdisciplinary topic, both due to their production and validation methods, as well as their significance for numerous disciplines. The most utilized contemporary topographic datasets worldwide are those of global DEMs. Several space-based sources have been used for the production of (almost) global DEMs, namely satellite Synthetic Aperture Radar (SAR) Interferometry/InSAR, stereoscopy of multispectral satellite images and altimetry, producing several versions of autonomous or mixed products (i.e. SRTM, ACE, ASTER-GDEM). Complementary space-based observations, such as those of Global Navigation Satellite Systems (GNSS), are also used, mainly for validation purposes. The apparent positive impact of these elevation datasets so far has been consolidated by the plethora of related scientific, civil and military applications. Topography is a prominent element for almost all Earth sciences, but in Geomorphology it is even more fundamental. In geomorphological studies, elevation data and thus DEMs can be extensively used for the extraction of both qualitative and quantitative information, such as relief classification, determination of slope and slope orientation, delineation of drainage basins, extraction of drainage networks and much more. Global DEMs are constantly becoming finer, i.e. of higher spatial resolution and more "sensitive" to elevation changes, i.e. of higher vertical accuracy and these progresses are undoubtedly considered as a major breakthrough, each time a new improved global DEM is released. Nevertheless, for Geomorphology in particular, if not already there, we are close to the point in time, where the need for discrimination between DSM (Digital Surface Model) and DTM (Digital Terrain Model) is becoming critical; if the distinction between vegetation and man-made structures on one side (DSM), and actual terrain elevation on the other side (DTM) cannot be made, then, in many cases, any further increase of elevation accuracy in DEMs will have little impact on geomorphological studies. After shortly reviewing the evolution of satellite-based global DEMs, the purpose of this paper is to address their current limitations and challenges from the perspective of a geomorphologist. Subsequently, the implications for geomorphological studies are discussed, with respect to the expected near-future advances in the field, such as the TanDEM-X Global Digital Elevation Model ("WorldDEM", 2014), as well as spaceborne LIDAR (Light Detection and Ranging) approaches (e.g. Lidar Surface Topography/LIST mission, 2016-2020).

Finite mass enhancement across bandwidth controlled Mott transition in NiS2-xSex

NASA Astrophysics Data System (ADS)

Han, Garam; Kyung, W. S.; Kim, Y. K.; Cheng, C. M.; Tsuei, K. D.; Lee, K. D.; Hur, N.; Kim, H.-D.; Kim, C.

One of the most important and still debated issues in the strongly correlated electron systems is on the metal insulator transition (MIT) mechanism. In the bandwidth controlled Mott transition (BCMT) scenario, which Mott originally proposed, MIT occurs through a mass divergence in which the effective mass of the quasi-particle (QP) diverges approaching the MIT. The interpretation is supported by dynamic mean field theory (DMFT) model calculations. However, few direct observations have been made yet due to various experimental restrictions. In this talk, I present systematic angle resolved photoemission studies on the MIT in NiS2-xSex, which is a well-known BCMT material. We observed not only the bandwidth shrinkage but also the coherent quasi-particle peak (QP) which is not of the surface origin. In addition, we experimentally showed the mass of the QP remains finite approaching the MIT. This work was supported by IBS-R009-D1.

No Substitute for Going to the Field: Correcting Lidar DEMs in Salt Marshes

NASA Astrophysics Data System (ADS)

Renken, K.; Morris, J. T.; Lynch, J.; Bayley, H.; Neil, A.; Rasmussen, S.; Tyrrell, M.; Tanis, M.

2016-12-01

Models that forecast the response of salt marshes to current and future trends in sea level rise increasingly are used to guide management of these vulnerable ecosystems. Lidar-derived DEMs serve as the foundation for modeling landform change. However, caution is advised when using these DEMs as the starting point for models of salt marsh evolution. While broad vegetation class (i.e., young forest, old forest, grasslands, desert, etc.) has proven to be a significant predictor of vertical displacement error in terrestrial environments, differentiating error among different species or community types within the same ecosystem has received less attention. Salt marshes are dominated by monocultures of grass species and thus are an ideal environment to examine the within-species effect on lidar DEM error. We analyzed error of lidar DEMs using elevations from real-time kinematic (RTK) surveys in saltmarshes in multiple national parks and wildlife refuge areas from the mouth of the Chesapeake Bay to Massachusetts. Error of the lidar DEMs was sometimes large, on the order of 0.25 m, and varied significantly between sites because vegetation cover varies seasonally and lidar data was not always collected in the same season for each park. Vegetation cover and composition were used to explain differences between RTK elevations and lidar DEMs. This research underscores the importance of collecting RTK elevation data and vegetation cover data coincident with lidar data to produce correction factors specific to individual salt marsh sites.

Multiscale geomorphometric modeling of Mercury

NASA Astrophysics Data System (ADS)

Florinsky, I. V.

2018-02-01

Topography is one of the key characteristics of a planetary body. Geomorphometry deals with quantitative modeling and analysis of the topographic surface and relationships between topography and other natural components of landscapes. The surface of Mercury is systematically studied by interpretation of images acquired during the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission. However, the Mercurian surface is still little explored by methods of geomorphometry. In this paper, we evaluate the Mercury MESSENGER Global DEM MSGR_DEM_USG_SC_I_V02 - a global digital elevation model (DEM) of Mercury with the resolution of 0.015625° - as a source for geomorphometric modeling of this planet. The study was performed at three spatial scales: the global, regional (the Caloris basin), and local (the Pantheon Fossae area) ones. As the initial data, we used three DEMs of these areas with resolutions of 0.25°, 0.0625°, and 0.015625°, correspondingly. The DEMs were extracted from the MESSENGER Global DEM. From the DEMs, we derived digital models of several fundamental morphometric variables, such as: slope gradient, horizontal curvature, vertical curvature, minimal curvature, maximal curvature, catchment area, and dispersive area. The morphometric maps obtained represent peculiarities of the Mercurian topography in different ways, according to the physical and mathematical sense of a particular variable. Geomorphometric models are a rich source of information on the Mercurian surface. These data can be utilized to study evolution and internal structure of the planet, for example, to visualize and quantify regional topographic differences as well as to refine geological boundaries.

Lunar Polar Illumination for Power Analysis

NASA Technical Reports Server (NTRS)

Fincannon, James

2008-01-01

This paper presents illumination analyses using the latest Earth-based radar digital elevation model (DEM) of the lunar south pole and an independently developed analytical tool. These results enable the optimum sizing of solar/energy storage lunar surface power systems since they quantify the timing and durations of illuminated and shadowed periods. Filtering and manual editing of the DEM based on comparisons with independent imagery were performed and a reduced resolution version of the DEM was produced to reduce the analysis time. A comparison of the DEM with lunar limb imagery was performed in order to validate the absolute heights over the polar latitude range, the accuracy of which affects the impact of long range, shadow-casting terrain. Average illumination and energy storage duration maps of the south pole region are provided for the worst and best case lunar day using the reduced resolution DEM. Average illumination fractions and energy storage durations are presented for candidate low energy storage duration south pole sites. The best site identified using the reduced resolution DEM required a 62 hr energy storage duration using a fast recharge power system. Solar and horizon terrain elevations as well as illumination fraction profiles are presented for the best identified site and the data for both the reduced resolution and high resolution DEMs compared. High resolution maps for three low energy storage duration areas are presented showing energy storage duration for the worst case lunar day, surface height, and maximum absolute surface slope.

Engineering the Business of Defense Acquisition: An Analysis of Program Office Processes

DTIC Science & Technology

2015-05-01

Information Technology and Business Process Redesign | MIT Sloan Management Review . MIT Sloan Management Review . Retrieved from http://sloanreview.mit.edu...links systems management to process execution Three Phases/ Multi-Year Effort (This Phase) Literature review Model development— Formal and...estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining

Hide and Seek: Exploiting and Hardening Leakage-Resilient Code Randomization

DTIC Science & Technology

2016-05-30

Hide and Seek: Exploiting and Hardening Leakage -Resilient Code Randomization Robert Rudd MIT Lincoln Laboratory Thomas Hobson MIT Lincoln Laboratory...Irvine Ahmad-Reza Sadeghi TU Darmstadt Hamed Okhravi MIT Lincoln Laboratory Abstract Information leakage vulnerabilities can allow adversaries to...bypass mitigations based on code randomization. This discovery motivates numerous techniques that diminish direct and indirect information leakage : (i

Hide and Seek: Exploiting and Hardening Leakage-Resilient Code Randomization

DTIC Science & Technology

2016-03-30

Hide and Seek: Exploiting and Hardening Leakage -Resilient Code Randomization Robert Rudd MIT Lincoln Laboratory Thomas Hobson MIT Lincoln Laboratory...Irvine Ahmad-Reza Sadeghi TU Darmstadt Hamed Okhravi MIT Lincoln Laboratory Abstract Information leakage vulnerabilities can allow adversaries to...bypass mitigations based on code randomization. This discovery motivates numerous techniques that diminish direct and indirect information leakage : (i

Data Driven Change Is Easy; Assessing and Maintaining It Is the Hard Part

ERIC Educational Resources Information Center

Perelman, Les

2009-01-01

At MIT in the 1990's, data from two sources, a study of the writing ability of a small group of randomly selected MIT juniors correlated to their overall academic performance and a survey of alumni from various years provided the major motivation for the development by MIT faculty and administration of a very ambitious…

ARPES studies on metal-insulator-transition in NiS2-xSex

NASA Astrophysics Data System (ADS)

Han, Garam; Kim, Y. K.; Kyung, W. S.; Kim, Chul; Koh, Y. Y.; Lee, K. D.; Kim, C.

2012-02-01

Understanding Metal insulator transition (MIT) is one of the most challenging issues in condensed matter physics. NiS2-xSex (NSS) is a well known system for band width controlled MIT studies while most of High-Tc superconductors (HTSCs) are described within band filling MIT picture. Cubic pyrite NiS2 is known as a charge-transfer (CT) insulator and easily forms a solid solution with NiSe2, which is a good metal even though it is isostrucural and isoelectronic to NiS2. MIT is induced by Se alloying and is observed at a low temperature for x=0.5. The important merit is that there is no structure transition which often accompanies MIT. In spite of the importance of the system, even the experimental band dispersion is not known so far along with many controversies. For this reason, we performed angle resolved photoemission spectroscopy on high quality single crystals and successfully obtained Fermi surface maps of x=0.5, x=0.7 and x=0.8 systems (the metallic side). By doping dependent systematic studies on NSS and comparison with LDA calculation, we try to explain the relationship between band width and the MIT.

Magnetically driven metal-insulator transition in NaOsO3

NASA Astrophysics Data System (ADS)

Calder, Stuart

2013-03-01

The metal-insulator transition (MIT) is one of the most dramatic manifestations of electron correlations in materials, enjoying interest both for its fundamental nature and technological application. Various mechanisms producing MITs have been extensively considered over the years, including the Mott (electron localization via Coulomb repulsion), Anderson (localization via disorder) and Peierls (localization via distortion of a periodic one-dimensional lattice). One additional route to a MIT proposed by Slater in 1951, in which long-range magnetic order in a three dimensional system drives the MIT, has received relatively little attention, particularly from an experimental viewpoint. Using neutron and x-ray scattering we have shown that the MIT in NaOsO3 is coincident with the onset of long-range commensurate magnetic order at 410 K. Whilst candidate materials have been suggested, our experimental methodology allows the first definitive demonstration of the long predicted Slater MIT. We discuss our results in light of recent work on other 5d systems that contrastingly have been predicted to host a Mott spin-orbit insulating state. Work was supported by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy (DOE).

Shape and Albedo from Shading (SAfS) for Pixel-Level dem Generation from Monocular Images Constrained by Low-Resolution dem

NASA Astrophysics Data System (ADS)

Wu, Bo; Chung Liu, Wai; Grumpe, Arne; Wöhler, Christian

2016-06-01

Lunar topographic information, e.g., lunar DEM (Digital Elevation Model), is very important for lunar exploration missions and scientific research. Lunar DEMs are typically generated from photogrammetric image processing or laser altimetry, of which photogrammetric methods require multiple stereo images of an area. DEMs generated from these methods are usually achieved by various interpolation techniques, leading to interpolation artifacts in the resulting DEM. On the other hand, photometric shape reconstruction, e.g., SfS (Shape from Shading), extensively studied in the field of Computer Vision has been introduced to pixel-level resolution DEM refinement. SfS methods have the ability to reconstruct pixel-wise terrain details that explain a given image of the terrain. If the terrain and its corresponding pixel-wise albedo were to be estimated simultaneously, this is a SAfS (Shape and Albedo from Shading) problem and it will be under-determined without additional information. Previous works show strong statistical regularities in albedo of natural objects, and this is even more logically valid in the case of lunar surface due to its lower surface albedo complexity than the Earth. In this paper we suggest a method that refines a lower-resolution DEM to pixel-level resolution given a monocular image of the coverage with known light source, at the same time we also estimate the corresponding pixel-wise albedo map. We regulate the behaviour of albedo and shape such that the optimized terrain and albedo are the likely solutions that explain the corresponding image. The parameters in the approach are optimized through a kernel-based relaxation framework to gain computational advantages. In this research we experimentally employ the Lunar-Lambertian model for reflectance modelling; the framework of the algorithm is expected to be independent of a specific reflectance model. Experiments are carried out using the monocular images from Lunar Reconnaissance Orbiter (LRO) Narrow Angle Camera (NAC) (0.5 m spatial resolution), constrained by the SELENE and LRO Elevation Model (SLDEM 2015) of 60 m spatial resolution. The results indicate that local details are largely recovered by the algorithm while low frequency topographic consistency is affected by the low-resolution DEM.

How large is the Upper Indus Basin? The pitfalls of auto-delineation using DEMs

NASA Astrophysics Data System (ADS)

Khan, Asif; Richards, Keith S.; Parker, Geoffrey T.; McRobie, Allan; Mukhopadhyay, Biswajit

2014-02-01

Extraction of watershed areas from Digital Elevation Models (DEMs) is increasingly required in a variety of environmental analyses. It is facilitated by the availability of DEMs based on remotely sensed data, and by Geographical Information System (GIS) software. However, accurate delineation depends on the quality of the DEM and the methodology adopted. This paper considers automated and supervised delineation in a case study of the Upper Indus Basin (UIB), Pakistan, for which published estimates of the basin area show significant disagreement, ranging from 166,000 to 266,000 km2. Automated delineation used ArcGIS Archydro and hydrology tools applied to three good quality DEMs (two from SRTM data with 90m resolution, and one from 30m resolution ASTER data). Automatic delineation defined a basin area of c.440,000 km2 for the UIB, but included a large area of internal drainage in the western Tibetan Plateau. It is shown that discrepancies between different estimates reflect differences in the initial extent of the DEM used for watershed delineation, and the unchecked effect of iterative pit-filling of the DEM (going beyond the filling of erroneous pixels to filling entire closed basins). For the UIB we have identified critical points where spurious addition of catchment area has arisen, and use Google Earth to examine the geomorphology adjacent to these points, and also examine the basin boundary data provided by the HydroSHEDS database. We show that the Pangong Tso watershed and some other areas in the western Tibetan plateau are not part of the UIB, but are areas of internal drainage. Our best estimate of the area of the Upper Indus Basin (at Besham Qila) is 164,867 km2 based on the SRTM DEM, and 164,853 km2 using the ASTER DEM). This matches the catchment area measured by WAPDA SWHP. An important lesson from this investigation is that one should not rely on automated delineation, as iterative pit-filling can produce spurious drainage networks and basins, when there are areas of internal drainage nearby.

Investigation on Glacier Thinning in Baspa, Western Himalaya.

NASA Astrophysics Data System (ADS)

S, P.; Kulkarni, A. V.; Bhushan, S.

2017-12-01

Mass balance studies are important to assess the state of glaciers. Previously, numerous field investigations have been carried out in Baspa basin to measure mass balance. However, mass balance data from field are limited to a small number of glaciers and for short durations. Therefore, this study uses geodetic mass balance technique to evaluate the mass loss at decadal scale. Geodetic method involves differencing Digital Elevation Model (DEM) from different years to obtain change in glacier elevation, which will be subsequently used to evaluate mass balance. This study derives mass balance from 2000 to 2014 for 16 glaciers covering a total area of 70 Sq Km. The study uses Shuttle Radar Topography Mission (SRTM) DEM for year 2000 and DEM for year 2014 was derived from Cartosat-1 stereo pair using photogrammetric principles. A Differential Global Positioning System (DGPS) survey was conducted in Baspa basin at different elevation zones to collect Ground Control Points (GCP) with millimeters accuracy. These GCP were used to derive Cartosat DEM. Various corrections were applied before differencing the two DEMs. They were co-registered using an analytical approach to account for horizontal shift. Corrections were also applied to remove the bias due to satellite acquisition geometry. SRTM DEM was acquired in February when the study area was covered by seasonal snow, whereas, Cartosat data was acquired during the ablation season. As the season of data acquisition varies for the two DEM, we have corrected for the bias that could be caused due to seasonal snow. Snowfall data from a meteorological station in the Baspa valley and a local precipitation gradient were used to determine the seasonal snow depth. Further, corrections were applied to account for the bias due to radar penetration in SRTM DEM. Then, the elevation changes were determined by subtracting the two DEMs to estimate mass balance. The figure below shows the change in glacier elevation. These results will be validated with field estimates. This investigation, after validation, will be an important addition in understanding changes in Himalayan glaciers.

A Combined SRTM Digital Elevation Model for Zanjan State of Iran Based on the Corrective Surface Idea

NASA Astrophysics Data System (ADS)

Kiamehr, Ramin

2016-04-01

One arc-second high resolution version of the SRTM model recently published for the Iran by the US Geological Survey database. Digital Elevation Models (DEM) is widely used in different disciplines and applications by geoscientist. It is an essential data in geoid computation procedure, e.g., to determine the topographic, downward continuation (DWC) and atmospheric corrections. Also, it can be used in road location and design in civil engineering and hydrological analysis. However, a DEM is only a model of the elevation surface and it is subject to errors. The most important parts of errors could be comes from the bias in height datum. On the other hand, the accuracy of DEM is usually published in global sense and it is important to have estimation about the accuracy in the area of interest before using of it. One of the best methods to have a reasonable indication about the accuracy of DEM is obtained from the comparison of their height versus the precise national GPS/levelling data. It can be done by the determination of the Root-Mean-Square (RMS) of fitting between the DEM and leveling heights. The errors in the DEM can be approximated by different kinds of functions in order to fit the DEMs to a set of GPS/levelling data using the least squares adjustment. In the current study, several models ranging from a simple linear regression to seven parameter similarity transformation model are used in fitting procedure. However, the seven parameter model gives the best fitting with minimum standard division in all selected DEMs in the study area. Based on the 35 precise GPS/levelling data we obtain a RMS of 7 parameter fitting for SRTM DEM 5.5 m, The corrective surface model in generated based on the transformation parameters and included to the original SRTM model. The result of fitting in combined model is estimated again by independent GPS/leveling data. The result shows great improvement in absolute accuracy of the model with the standard deviation of 3.4 meter.

Seasonal and interannual evolution of Jakobshavn Isbrae, Greenland from a 2008-2015 high-res DEM and velocity time series

NASA Astrophysics Data System (ADS)

Shean, D. E.; Joughin, I.; Smith, B.; Floricioiu, D.

2015-12-01

Greenland's large marine-terminating outlet glaciers have displayed marked retreat, speedup, and thinning in recent decades. Jakobshavn Isbrae, one of Greenland's largest outlet glaciers, has retreated ~15 km, accelerated ~150%, and thinned ~200 m since the early 1990s. Here, we present a comprehensive analysis of high-resolution elevation (~2-5 m/px) and velocity (~100 m/px) time series with dense temporal coverage (daily-monthly). The Jakobshavn DEM time series consists of >70 WorldView-1/2/3 stereo DEMs and >11 TanDEM-X DEMs spanning 2008-2015. Complementary point elevation data from Operation IceBridge (ATM, LVIS), pre-IceBridge ATM flights, and ICESat-1 GLAS extend the surface elevation record to 1999 and provide essential absolute control data, enabling sub-meter horizontal/vertical accuracy for gridded DEMs. Velocity data are primarily derived from TerraSAR-X/TanDEM-X image pairs with 11-day interval from 2009-2015. These elevation and velocity data capture outlet glacier evolution with unprecedented detail during the post-ICESat era. The lower trunk of Jakobshavn displays significant seasonal velocity variations, with recent rates of ~8 km/yr during winter and >17 km/yr during summer. DEM data show corresponding seasonal elevation changes of -30 to -45 m in summer and +15 to +20 m in winter, with decreasing magnitude upstream. Seasonal discharge varies from ~30-35 Gt/yr in winter to ~45-55 Gt/yr in summer, and we integrate these measurements for improved long-term mass-balance estimates. Recent interannual trends show increased discharge, velocity, and thinning (-15 to -20 m/yr), which is consistent with long-term altimetry records. The DEM time series also reveal new details about calving front and mélange evolution during the seasonal cycle. Similar time series are available for Kangerdlugssuaq and Helheim Glaciers. These observations are improving our understanding of outlet glacier dynamics, while complementing ongoing efforts to constrain estimates for ice-sheet mass balance and present/future sea level rise contributions.

Long-lived mitochondrial (Mit) mutants of Caenorhabditis elegans utilize a novel metabolism.

PubMed

Butler, Jeffrey A; Ventura, Natascia; Johnson, Thomas E; Rea, Shane L

2010-12-01

The Caenorhabditis elegans mitochondrial (Mit) mutants have disrupted mitochondrial electron transport chain (ETC) functionality, yet, surprisingly, they are long lived. We have previously proposed that Mit mutants supplement their energy needs by exploiting alternate energy production pathways normally used by wild-type animals only when exposed to hypoxic conditions. We have also proposed that longevity in the Mit mutants arises as a property of their new metabolic state. If longevity does arise as a function of metabolic state, we would expect to find a common metabolic signature among these animals. To test these predictions, we established a novel approach monitoring the C. elegans exometabolism as a surrogate marker for internal metabolic events. Using HPLC-ultraviolet-based metabolomics and multivariate analyses, we show that long-lived clk-1(qm30) and isp-1(qm150) Mit mutants have a common metabolic profile that is distinct from that of aerobically cultured wild-type animals and, unexpectedly, wild-type animals cultured under severe oxygen deprivation. Moreover, we show that 2 short-lived mitochondrial ETC mutants, mev-1(kn1) and ucr-2.3(pk732), also share a common metabolic signature that is unique. We show that removal of soluble fumarate reductase unexpectedly increases health span in several genetically defined Mit mutants, identifying at least 1 alternate energy production pathway, malate dismutation, that is operative in these animals. Our study suggests long-lived, genetically specified Mit mutants employ a novel metabolism and that life span may well arise as a function of metabolic state.

Structural Fine-Tuning of MIT-Interacting Motif 2 (MIM2) and Allosteric Regulation of ESCRT-III by Vps4 in Yeast.

PubMed

Kojima, Rieko; Obita, Takayuki; Onoue, Kousuke; Mizuguchi, Mineyuki

2016-06-05

The endosomal sorting complex required for transport (ESCRT) facilitates roles in membrane remodeling, such as multivesicular body biogenesis, enveloped virus budding and cell division. In yeast, Vps4 plays a crucial role in intraluminal vesicle formation by disassembling ESCRT proteins. Vps4 is recruited by ESCRT-III proteins to the endosomal membrane through the interaction between the microtubule interacting and trafficking (MIT) domain of Vps4 and the C-terminal MIT-interacting motif (MIM) of ESCRT-III proteins. Here, we have determined the crystal structure of Vps4-MIT in a complex with Vps20, a member of ESCRT-III, and revealed that Vps20 adopts a unique MIM2 conformation. Based on structural comparisons with other known MIM2s, we have refined the consensus sequence of MIM2. We have shown that another ESCRT-III protein, Ist1, binds to Vps4-MIT via its C-terminal MIM1 with higher affinity than Vps2, but lacks MIM2 by surface plasmon resonance. Surprisingly, the Ist1 MIM1 competed with the MIM2 of Vfa1, a regulator of Vps4, for binding to Vps4-MIT, even though these MIMs bind in non-overlapping sites on the MIT. These findings provide insight into the allosteric recognition of MIMs of ESCRT-III by Vps4 and also the regulation of ESCRT machinery at the last step of membrane remodeling. Copyright © 2016 Elsevier Ltd. All rights reserved.

Melodic Intonation Therapy: Back to Basics for Future Research

PubMed Central

Zumbansen, Anna; Peretz, Isabelle; Hébert, Sylvie

2014-01-01

We present a critical review of the literature on melodic intonation therapy (MIT), one of the most formalized treatments used by speech-language therapist in Broca’s aphasia. We suggest basic clarifications to enhance the scientific support of this promising treatment. First, therapeutic protocols using singing as a speech facilitation technique are not necessarily MIT. The goal of MIT is to restore propositional speech. The rationale is that patients can learn a new way to speak through singing by using language-capable regions of the right cerebral hemisphere. Eventually, patients are supposed to use this way of speaking permanently but not to sing overtly. We argue that many treatment programs covered in systematic reviews on MIT’s efficacy do not match MIT’s therapeutic goal and rationale. Critically, we identified two main variations of MIT: the French thérapie mélodique et rythmée (TMR) that trains patients to use singing overtly as a facilitation technique in case of speech struggle and palliative versions of MIT that help patients with the most severe expressive deficits produce a limited set of useful, readymade phrases. Second, we distinguish between the immediate effect of singing on speech production and the long-term effect of the entire program on language recovery. Many results in the MIT literature can be explained by this temporal perspective. Finally, we propose that MIT can be viewed as a treatment of apraxia of speech more than aphasia. This issue should be explored in future experimental studies. PMID:24478754

Motor imagery training promotes motor learning in adolescents with cerebral palsy: comparison between left and right hemiparesis.

PubMed

Cabral-Sequeira, Audrey Sartori; Coelho, Daniel Boari; Teixeira, Luis Augusto

2016-06-01

This experiment was designed to evaluate the effects of pure motor imagery training (MIT) and its combination with physical practice on learning an aiming task with the more affected arm in adolescents suffering from cerebral palsy. Effect of MIT was evaluated as a function of side of hemiparesis. The experiment was accomplished by 11- to 16-year-old participants (M = 13.58 years), who suffered left (n = 16) or right (n = 15) mild hemiparesis. They were exposed to pure MIT (day 1) followed by physical practice (day 2) on an aiming task demanding movement accuracy and speed. Posttraining movement kinematics of the group receiving MIT were compared with movement kinematics of the control group after receiving recreational activities (day 1) and physical practice (day 2). Kinematic analysis showed that MIT led to decreased movement time and straighter hand displacements to the target. Performance achievements from MIT were increased with further physical practice, leading to enhanced effects on motor learning. Retention evaluation indicated that performance improvement from pure MIT and its combination with physical practice were stable over time. Performance achievements were equivalent between adolescents with either right or left hemiparesis, suggesting similar capacity between these groups to achieve performance improvement from pure imagery training and from its association with physical practice. Our results suggest that motor imagery training is a procedure potentially useful to increase motor learning achievements in individuals suffering from cerebral palsy.

Registratiom of TM data to digital elevation models

NASA Technical Reports Server (NTRS)

1984-01-01

Several problems arise when attempting to register LANDSAT thematic mapper data to U.S. B Geological Survey digital elevation models (DEMs). The TM data are currently available only in a rotated variant of the Space Oblique Mercator (SOM) map projection. Geometric transforms are thus; required to access TM data in the geodetic coordinates used by the DEMs. Due to positional errors in the TM data, these transforms require some sort of external control. The spatial resolution of TM data exceeds that of the most commonly DEM data. Oversampling DEM data to TM resolution introduces systematic noise. Common terrain processing algorithms (e.g., close computation) compound this problem by acting as high-pass filters.

Analysis of accuracy of digital elevation models created from captured data by digital photogrammetry method

NASA Astrophysics Data System (ADS)

Hudec, P.

2011-12-01

A digital elevation model (DEM) is an important part of many geoinformatic applications. For the creation of DEM, spatial data collected by geodetic measurements in the field, photogrammetric processing of aerial survey photographs, laser scanning and secondary sources (analogue maps) are used. It is very important from a user's point of view to know the vertical accuracy of a DEM. The article describes the verification of the vertical accuracy of a DEM for the region of Medzibodrožie, which was created using digital photogrammetry for the purposes of water resources management and modeling and resolving flood cases based on geodetic measurements in the field.

50th Annual Technical Meeting of the Society of Engineering Science (SES)

DTIC Science & Technology

2014-08-15

McDowell (Gerogia Tech), Min Zhou () Virtual Characterization of composites with Lamination Defects for wind turbine spar cap MUKUNDAN SRINIVASAN...Zhang (IHCP Singapore) Damage Mechanisms in Irradiated Metallic Glasses Richard Baumer (MIT), Michael Demkowicz (MIT) Slip Avalanches in Amorphous...Michigan, 48090) Atomistic Simulations of c+a Pyramidal Slip in Magnesium Single Crystal under Compression Xiaozhi Tang (MIT & BJTU), Yafang Guo

One for All and All for One: Using Multiple Identification Theory Simulations to Build Cooperative Attitudes and Behaviors in a Middle Eastern Conflict Scenario

ERIC Educational Resources Information Center

Williams, Robert Howard; Williams, Alexander Jonathan

2010-01-01

The authors previously developed multiple identification theory (MIT) as a system of simulation game design intended to promote attitude change. The present study further tests MIT's effectiveness. The authors created a game (CULTURE & CREED) via MIT as a complex simulation of Middle Eastern conflict resolution, designed to change attitudes…

Monitoring lava dome changes by means of differential DEMs from TanDEM-X interferometry: Examples from Merapi, Indonesia and Volcán de Colima, Mexico

NASA Astrophysics Data System (ADS)

Kubanek, J.; Westerhaus, M.; Heck, B.

2013-12-01

Estimating the amount of erupted material during a volcanic crisis is one of the major challenges in volcano research. One way to do this and to discriminate between juvenile and non-juvenile fraction is to assess topographic changes before and after an eruption while using area-wide 3D data. LiDAR or other airborne systems may be a good source, but the recording fails when clouds due to volcanic activity obstruct the sight. In addition, costs as well as logistics are high for local observatories. When dealing with dome-building volcanoes, acquiring the data gets further complicated. As the volcano dome can change rapidly in active phases, it is nearly impossible to collect data at the right time. However, when dealing with gross volume change estimates, at least two data sets - taken directly before and after the eruption - are essential. The innovative German Earth observation mission TanDEM-X (TerraSAR-X add-on for Digital Elevation Measurement) is of great importance to overcome some of these problems. The two almost identical radar satellites TerraSAR-X and TanDEM-X fly in a close formation, thus recording images of the same place on the Earth surface at the same time (bistatic mode). As the radar signal penetrates clouds, digital elevation models (DEMs) of the area of investigation can be generated without problems even with cloud cover. A time series analysis of the differential DEMs therefore opens the possibility to assess volume changes at active lava domes. We choose Merapi in Indonesia and Volcán de Colima in Mexico as test sites. Both volcanoes reside in a state of long term effusive eruption, interrupted every few years by phases of dome destruction, generation of pyroclastic flows and deposition of volcanic material. The availability of extensive ground truth data for both test sites further enables to validate the spaceborne data and results. Here, we analyze lava dome changes due to the hazardous Merapi 2010 eruption. We show a series of DEMs derived by TanDEM-X interferometry taken before and after the eruption. Our results reveal that the eruption had led to a topographic change of up to 200 m in the summit area of Merapi. We further show the ability of the TanDEM-X data to observe much smaller topographic changes using Volcán de Colima as second test site. An explosion at the crater rim signaled the end of magma ascent in June 2011. The bistatic TanDEM-X data give important information on this explosion as we can observe topographic changes of up to 20 m and less in the summit area when comparing datasets taken before and after the event. We further analyzed datasets from the beginning of the year 2013 when Colima got active again after a dormant period. Our results indicate that repeated DEMs with great detail and good accuracy are obtainable, enabling a quantitative estimation of volume changes in the summit area of the volcano. As the TanDEM-X mission is an innovative mission, the present study serves as a test to employ data of a new satellite mission in volcano research. An error analysis of the DEMs to evaluate the volume quantifications was therefore also conducted.

Modeling Weather Impact on Airport Arrival Miles-in-Trail Restrictions

NASA Technical Reports Server (NTRS)

Wang, Yao; Grabbe, Shon

2013-01-01

When the demand for either a region of airspace or an airport approaches or exceeds the available capacity, miles-in-trail (MIT) restrictions are the most frequently issued traffic management initiatives (TMIs) that are used to mitigate these imbalances. Miles-intrail operations require aircraft in a traffic stream to meet a specific inter-aircraft separation in exchange for maintaining a safe and orderly flow within the stream. This stream of aircraft can be departing an airport, over a common fix, through a sector, on a specific route or arriving at an airport. This study begins by providing a high-level overview of the distribution and causes of arrival MIT restrictions for the top ten airports in the United States. This is followed by an in-depth analysis of the frequency, duration and cause of MIT restrictions impacting the Hartsfield-Jackson Atlanta International Airport (ATL) from 2009 through 2011. Then, machine-learning methods for predicting (1) situations in which MIT restrictions for ATL arrivals are implemented under low demand scenarios, and (2) days in which a large number of MIT restrictions are required to properly manage and control ATL arrivals are presented. More specifically, these predictions were accomplished by using an ensemble of decision trees with Bootstrap aggregation (BDT) and supervised machine learning was used to train the BDT binary classification models. The models were subsequently validated using data cross validation methods. When predicting the occurrence of arrival MIT restrictions under low demand situations, the model was able to achieve over all accuracy rates ranging from 84% to 90%, with false alarm ratios ranging from 10% to 15%. In the second set of studies designed to predict days on which a high number of MIT restrictions were required, overall accuracy rates of 80% were achieved with false alarm ratios of 20%. Overall, the predictions proposed by the model give better MIT usage information than what has been currently provided under current day operations. Traffic flow managers can use these predictions to identify potential MIT restrictions to eliminate (e.g., those occurring during low arrival demand periods), and to determine the days in which a significant number of restrictions may be required

Improved Topographic Mapping Through Multi-Baseline SAR Interferometry with MAP Estimation

NASA Astrophysics Data System (ADS)

Dong, Yuting; Jiang, Houjun; Zhang, Lu; Liao, Mingsheng; Shi, Xuguo

2015-05-01

There is an inherent contradiction between the sensitivity of height measurement and the accuracy of phase unwrapping for SAR interferometry (InSAR) over rough terrain. This contradiction can be resolved by multi-baseline InSAR analysis, which exploits multiple phase observations with different normal baselines to improve phase unwrapping accuracy, or even avoid phase unwrapping. In this paper we propose a maximum a posteriori (MAP) estimation method assisted by SRTM DEM data for multi-baseline InSAR topographic mapping. Based on our method, a data processing flow is established and applied in processing multi-baseline ALOS/PALSAR dataset. The accuracy of resultant DEMs is evaluated by using a standard Chinese national DEM of scale 1:10,000 as reference. The results show that multi-baseline InSAR can improve DEM accuracy compared with single-baseline case. It is noteworthy that phase unwrapping is avoided and the quality of multi-baseline InSAR DEM can meet the DTED-2 standard.

Estimating River Surface Elevation From ArcticDEM

NASA Astrophysics Data System (ADS)

Dai, Chunli; Durand, Michael; Howat, Ian M.; Altenau, Elizabeth H.; Pavelsky, Tamlin M.

2018-04-01

ArcticDEM is a collection of 2-m resolution, repeat digital surface models created from stereoscopic satellite imagery. To demonstrate the potential of ArcticDEM for measuring river stages and discharges, we estimate river surface heights along a reach of Tanana River near Fairbanks, Alaska, by the precise detection of river shorelines and mapping of shorelines to land surface elevation. The river height profiles over a 15-km reach agree with in situ measurements to a standard deviation less than 30 cm. The time series of ArcticDEM-derived river heights agree with the U.S. Geological Survey gage measurements with a standard deviation of 32 cm. Using the rating curve for that gage, we obtain discharges with a validation accuracy (root-mean-square error) of 234 m3/s (23% of the mean discharge). Our results demonstrate that ArcticDEM can accurately measure spatial and temporal variations of river surfaces, providing a new and powerful data set for hydrologic analysis.

Visuospatial characteristics of an elderly Chinese population: results from the WAIS-R block design test.

PubMed

Yin, Shufei; Zhu, Xinyi; Huang, Xin; Li, Juan

2015-01-01

Visuospatial deficits have long been recognized as a potential predictor of dementia, with visuospatial ability decline having been found to accelerate in later stages of dementia. We, therefore, believe that the visuospatial performance of patients with mild cognitive impairment (MCI) and dementia (Dem) might change with varying visuospatial task difficulties. This study administered the Wechsler Adult Intelligence Scale-Revised (WAIS-R) Block Design Test (BDT) to determine whether visuospatial ability can help discriminate between MCI patients from Dem patients and normal controls (NC). Results showed that the BDT could contribute to the discrimination between MCI and Dem. Specifically, simple BDT task scores could best distinguish MCI from Dem patients, while difficult BDT task scores could contribute to discriminating between MCI and NC. Given the potential clinical value of the BDT in the diagnosis of Dem and MCI, normative data stratified by age and education for the Chinese elderly population are presented for use in research and clinical settings.

DEM GPU studies of industrial scale particle simulations for granular flow civil engineering applications

NASA Astrophysics Data System (ADS)

Pizette, Patrick; Govender, Nicolin; Wilke, Daniel N.; Abriak, Nor-Edine

2017-06-01

The use of the Discrete Element Method (DEM) for industrial civil engineering industrial applications is currently limited due to the computational demands when large numbers of particles are considered. The graphics processing unit (GPU) with its highly parallelized hardware architecture shows potential to enable solution of civil engineering problems using discrete granular approaches. We demonstrate in this study the pratical utility of a validated GPU-enabled DEM modeling environment to simulate industrial scale granular problems. As illustration, the flow discharge of storage silos using 8 and 17 million particles is considered. DEM simulations have been performed to investigate the influence of particle size (equivalent size for the 20/40-mesh gravel) and induced shear stress for two hopper shapes. The preliminary results indicate that the shape of the hopper significantly influences the discharge rates for the same material. Specifically, this work shows that GPU-enabled DEM modeling environments can model industrial scale problems on a single portable computer within a day for 30 seconds of process time.

Preliminary GAOFEN-3 Insar dem Accuracy Analysis

NASA Astrophysics Data System (ADS)

Chen, Q.; Li, T.; Tang, X.; Gao, X.; Zhang, X.

2018-04-01

GF-3 satellite, the first C band and full-polarization SAR satellite of China with spatial resolution of 1 m, was successfully launched in August 2016. We analyze the error sources of GF-3 satellite in this paper, and provide the interferometric calibration model based on range function, Doppler shift equation and interferometric phase function, and interferometric parameters calibrated using the three-dimensional coordinates of ground control points. Then, we conduct the experimental two pairs of images in fine stripmap I mode covering Songshan of Henan Province and Tangshan of Hebei Province, respectively. The DEM data are assessed using SRTM DEM, ICESat-GLAS points, and ground control points database obtained using ZY-3 satellite to validate the accuracy of DEM elevation. The experimental results show that the accuracy of DEM extracted from GF-3 satellite SAR data can meet the requirements of topographic mapping in mountain and alpine regions at the scale of 1 : 50000 in China. Besides, it proves that GF-3 satellite has the potential of interferometry.

DEMS - a second generation diabetes electronic management system.

PubMed

Gorman, C A; Zimmerman, B R; Smith, S A; Dinneen, S F; Knudsen, J B; Holm, D; Jorgensen, B; Bjornsen, S; Planet, K; Hanson, P; Rizza, R A

2000-06-01

Diabetes electronic management system (DEMS) is a component-based client/server application, written in Visual C++ and Visual Basic, with the database server running Sybase System 11. DEMS is built entirely with a combination of dynamic link libraries (DLLs) and ActiveX components - the only exception is the DEMS.exe. DEMS is a chronic disease management system for patients with diabetes. It is used at the point of care by all members of the diabetes team including physicians, nurses, dieticians, clinical assistants and educators. The system is designed for maximum clinical efficiency and facilitates appropriately supervised delegation of care. Dispersed clinical sites may be supervised from a central location. The system is designed for ease of navigation; immediate provision of many types of automatically generated reports; quality audits; aids to compliance with good care guidelines; and alerts, advisories, prompts, and warnings that guide the care provider. The system now contains data on over 34000 patients and is in daily use at multiple sites.

Evaluation de la qualité de modèles numériques de terrain dérivés par interférométrieEvaluación de la calidad de modelos digitales de elevación derivados por interferometría

NASA Astrophysics Data System (ADS)

Gens, Rüdiger

One of the most important uses of SAR interferometry is in the generation of digital elevation models (DEMs). However, a standard procedure for quality estimation of DEMs does not exist. This paper proposes a method of quality estimation using an adapted Monte Carlo simulation, which has the advantage that it could be used in areas where appropriate reference DEMs are not available. This paper also addresses interferometric processing, with special emphasis on the influence of the input parameters. Practical implementation of the proposed technique is shown on a data set from Lower Saxony in Germany. The error map generated, which is a measure of the quality of the DEM, is also presented. For further analysis of the critical aspects of quality, a reference DEM has also been used.

A simplified DEM-CFD approach for pebble bed reactor simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Y.; Ji, W.

In pebble bed reactors (PBR's), the pebble flow and the coolant flow are coupled with each other through coolant-pebble interactions. Approaches with different fidelities have been proposed to simulate similar phenomena. Coupled Discrete Element Method-Computational Fluid Dynamics (DEM-CFD) approaches are widely studied and applied in these problems due to its good balance between efficiency and accuracy. In this work, based on the symmetry of the PBR geometry, a simplified 3D-DEM/2D-CFD approach is proposed to speed up the DEM-CFD simulation without significant loss of accuracy. Pebble flow is simulated by a full 3-D DEM, while the coolant flow field is calculatedmore » with a 2-D CFD simulation by averaging variables along the annular direction in the cylindrical geometry. Results show that this simplification can greatly enhance the efficiency for cylindrical core, which enables further inclusion of other physics such as thermal and neutronic effect in the multi-physics simulations for PBR's. (authors)« less

CapDEM - Toward a Capability Engineering Process: A Discussion Paper

DTIC Science & Technology

2005-09-01

Mokhtari DRDC Valcartier S. Lam DRDC Ottawa Defence R&D Canada – Valcartier Technical Report DRDC Valcartier TR 2004-230 September 2005 CapDEM...Toward a capability engineering process A discussion paper F. Bernier M. Couture G. Dussault C. Lalancette F. Lemieux M. Lizotte M. Mokhtari DRDC...Lizotte, M., Mokhtari , M. 2005. CapDEM – Toward capability engineering process definition: A discussion paper: A discussion paper. DRDC Valcartier

Estimating lava volume by precision combination of multiple baseline spaceborne and airborne interferometric synthetic aperture radar: The 1997 eruption of Okmok Volcano, Alaska

USGS Publications Warehouse

Lu, Z.; Fielding, E.; Patrick, M.R.; Trautwein, C.M.

2003-01-01

Interferometric synthetic aperture radar (InSAR) techniques are used to calculate the volume of extrusion at Okmok volcano, Alaska by constructing precise digital elevation models (DEMs) that represent volcano topography before and after the 1997 eruption. The posteruption DEM is generated using airborne topographic synthetic aperture radar (TOPSAR) data where a three-dimensional affine transformation is used to account for the misalignments between different DEM patches. The preeruption DEM is produced using repeat-pass European Remote Sensing satellite data; multiple interferograms are combined to reduce errors due to atmospheric variations, and deformation rates are estimated independently and removed from the interferograms used for DEM generation. The extrusive flow volume associated with the 1997 eruption of Okmok volcano is 0.154 ?? 0.025 km3. The thickest portion is approximately 50 m, although field measurements of the flow margin's height do not exceed 20 m. The in situ measurements at lava edges are not representative of the total thickness, and precise DEM data are absolutely essential to calculate eruption volume based on lava thickness estimations. This study is an example that demonstrates how InSAR will play a significant role in studying volcanoes in remote areas.

A New Lunar Digital Elevation Model from the Lunar Orbiter Laser Altimeter and SELENE Terrain Camera

NASA Technical Reports Server (NTRS)

Barker, M. K.; Mazarico, E.; Neumann, G. A.; Zuber, M. T.; Haruyama, J.; Smith, D. E.

2015-01-01

We present an improved lunar digital elevation model (DEM) covering latitudes within +/-60 deg, at a horizontal resolution of 512 pixels per degree ( approx.60 m at the equator) and a typical vertical accuracy approx.3 to 4 m. This DEM is constructed from approx.4.5 ×10(exp 9) geodetically-accurate topographic heights from the Lunar Orbiter Laser Altimeter (LOLA) onboard the Lunar Reconnaissance Orbiter, to which we co-registered 43,200 stereo-derived DEMs (each 1 deg×1 deg) from the SELENE Terrain Camera (TC) ( approx.10(exp 10) pixels total). After co-registration, approximately 90% of the TC DEMs show root-mean-square vertical residuals with the LOLA data of < 5 m compared to approx.50% prior to co-registration. We use the co-registered TC data to estimate and correct orbital and pointing geolocation errors from the LOLA altimetric profiles (typically amounting to < 10 m horizontally and < 1 m vertically). By combining both co-registered datasets, we obtain a near-global DEM with high geodetic accuracy, and without the need for surface interpolation. We evaluate the resulting LOLA + TC merged DEM (designated as "SLDEM2015") with particular attention to quantifying seams and crossover errors.

Uncertainty modelling and analysis of volume calculations based on a regular grid digital elevation model (DEM)

NASA Astrophysics Data System (ADS)

Li, Chang; Wang, Qing; Shi, Wenzhong; Zhao, Sisi

2018-05-01

The accuracy of earthwork calculations that compute terrain volume is critical to digital terrain analysis (DTA). The uncertainties in volume calculations (VCs) based on a DEM are primarily related to three factors: 1) model error (ME), which is caused by an adopted algorithm for a VC model, 2) discrete error (DE), which is usually caused by DEM resolution and terrain complexity, and 3) propagation error (PE), which is caused by the variables' error. Based on these factors, the uncertainty modelling and analysis of VCs based on a regular grid DEM are investigated in this paper. Especially, how to quantify the uncertainty of VCs is proposed by a confidence interval based on truncation error (TE). In the experiments, the trapezoidal double rule (TDR) and Simpson's double rule (SDR) were used to calculate volume, where the TE is the major ME, and six simulated regular grid DEMs with different terrain complexity and resolution (i.e. DE) were generated by a Gauss synthetic surface to easily obtain the theoretical true value and eliminate the interference of data errors. For PE, Monte-Carlo simulation techniques and spatial autocorrelation were used to represent DEM uncertainty. This study can enrich uncertainty modelling and analysis-related theories of geographic information science.

SediFoam: A general-purpose, open-source CFD-DEM solver for particle-laden flow with emphasis on sediment transport

NASA Astrophysics Data System (ADS)

Sun, Rui; Xiao, Heng

2016-04-01

With the growth of available computational resource, CFD-DEM (computational fluid dynamics-discrete element method) becomes an increasingly promising and feasible approach for the study of sediment transport. Several existing CFD-DEM solvers are applied in chemical engineering and mining industry. However, a robust CFD-DEM solver for the simulation of sediment transport is still desirable. In this work, the development of a three-dimensional, massively parallel, and open-source CFD-DEM solver SediFoam is detailed. This solver is built based on open-source solvers OpenFOAM and LAMMPS. OpenFOAM is a CFD toolbox that can perform three-dimensional fluid flow simulations on unstructured meshes; LAMMPS is a massively parallel DEM solver for molecular dynamics. Several validation tests of SediFoam are performed using cases of a wide range of complexities. The results obtained in the present simulations are consistent with those in the literature, which demonstrates the capability of SediFoam for sediment transport applications. In addition to the validation test, the parallel efficiency of SediFoam is studied to test the performance of the code for large-scale and complex simulations. The parallel efficiency tests show that the scalability of SediFoam is satisfactory in the simulations using up to O(107) particles.

Education Outreach at M.I.T. Plasma Science and Fusion Center

NASA Astrophysics Data System (ADS)

Rivenberg, P.; Censabella, V.

2000-10-01

At the MIT PSFC student and staff volunteers work together to increase the public's knowledge of fusion and plasma-related experiments. Seeking to generate excitement about science, engineering and mathematics, the PSFC holds a number of outreach activities throughout the year, including Middle and High School Outreach Days and the Mr. Magnet program. During the past year, in collaboration with the MIT Museum, the PSFC reprogrammed their C-Mod, Jr Video Game to be operated via the keyboard instead of joysticks. The game will eventually be available on the web and on disc. The PSFC maintains a Home Page on the World Wide Web, which can be reached at http://www.psfc.mit.edu.

High-resolution DEMs for High-mountain Asia: A systematic, region-wide assessment of geodetic glacier mass balance and dynamics

NASA Astrophysics Data System (ADS)

Shean, D. E.; Arendt, A. A.; Osmanoglu, B.; Montesano, P.

2017-12-01

High Mountain Asia (HMA) constitutes the largest glacierized region outside of the Earth's polar regions. Although available observations are limited, long-term records indicate sustained regional glacier mass loss since 1850, with increased loss in recent decades. Recent satellite data (e.g., GRACE, ICESat-1) show spatially variable glacier mass balance, with significant mass loss in the Himalaya and Hindu Kush and slight mass gain in the Karakoram. We generated 4000 high-resolution digital elevation models (DEMs) from sub-meter commercial stereo imagery (DigitalGlobe WorldView/GeoEye) acquired over glaciers in High-mountain Asia from 2002-present (mostly 2013-present). We produced a regional 8-m DEM mosaic for 2015 and estimated 15-year geodetic mass balance for 40000 glaciers larger than 0.1 km2. We are combining with other regional DEM sources to systematically document the spatiotemporal evolution of glacier mass balance for the entire HMA region. We also generated monthly to interannual DEM and velocity time series for high-priority sites distributed across the region, with >15-20 DEMs available for some locations from 2010-present. These records document glacier dynamics, seasonal snow accumulation/redistribution, and processes that affect glacier mass balance (e.g., ice-cliff retreat, debris cover evolution). These efforts will provide basin-scale assessments of snow/ice melt runoff contributions for model cal/val and downstream water resources applications. We will continue processing all archived and newly available commercial stereo imagery for HMA, and will release all DEMs through the HiMAT DAAC.

Enhanced ASTER DEMs for Decadal Measurements of Glacier Elevation Changes

NASA Astrophysics Data System (ADS)

Girod, L.; Nuth, C.; Kääb, A.

2016-12-01

Elevation change data is critical to the understanding of a number of geophysical processes, including glaciers through the measurement their volume change. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) system on-board the Terra (EOS AM-1) satellite has been a unique source of systematic stereoscopic images covering the whole globe at 15m resolution and at a consistent quality for over 15 years. While satellite stereo sensors with significantly improved radiometric and spatial resolution are available today, the potential of ASTER data lies in its long consistent time series that is unrivaled, though not fully exploited for change analysis due to lack of data accuracy and precision. ASTER data are strongly affected by attitude jitter, mainly of approximately 4 and 30 km wavelength, and improving the generation of ASTER DEMs requires removal of this effect. We developed MMASTER, an improved method for ASTER DEM generation and implemented it in the open source photogrammetric library and software suite MicMac. The method relies on the computation of a rational polynomial coefficients (RPC) model and the detection and correction of cross-track sensor jitter in order to compute DEMs. Our sensor modeling does not require ground control points and thus potentially allows for automatic processing of large data volumes. When compared to ground truth data, we have assessed a ±5m accuracy in DEM differencing when using our processing method, improved from the ±30m when using the AST14DMO DEM product. We demonstrate and discuss this improved ASTER DEM quality for a number of glaciers in Greenland (See figure attached), Alaska, and Svalbard. The quality of our measurements promises to further unlock the underused potential of ASTER DEMs for glacier volume change time series on a global scale. The data produced by our method will thus help to better understand the response of glaciers to climate change and their influence on runoff and sea level.

Parallelizing flow-accumulation calculations on graphics processing units—From iterative DEM preprocessing algorithm to recursive multiple-flow-direction algorithm

NASA Astrophysics Data System (ADS)

Qin, Cheng-Zhi; Zhan, Lijun

2012-06-01

As one of the important tasks in digital terrain analysis, the calculation of flow accumulations from gridded digital elevation models (DEMs) usually involves two steps in a real application: (1) using an iterative DEM preprocessing algorithm to remove the depressions and flat areas commonly contained in real DEMs, and (2) using a recursive flow-direction algorithm to calculate the flow accumulation for every cell in the DEM. Because both algorithms are computationally intensive, quick calculation of the flow accumulations from a DEM (especially for a large area) presents a practical challenge to personal computer (PC) users. In recent years, rapid increases in hardware capacity of the graphics processing units (GPUs) provided in modern PCs have made it possible to meet this challenge in a PC environment. Parallel computing on GPUs using a compute-unified-device-architecture (CUDA) programming model has been explored to speed up the execution of the single-flow-direction algorithm (SFD). However, the parallel implementation on a GPU of the multiple-flow-direction (MFD) algorithm, which generally performs better than the SFD algorithm, has not been reported. Moreover, GPU-based parallelization of the DEM preprocessing step in the flow-accumulation calculations has not been addressed. This paper proposes a parallel approach to calculate flow accumulations (including both iterative DEM preprocessing and a recursive MFD algorithm) on a CUDA-compatible GPU. For the parallelization of an MFD algorithm (MFD-md), two different parallelization strategies using a GPU are explored. The first parallelization strategy, which has been used in the existing parallel SFD algorithm on GPU, has the problem of computing redundancy. Therefore, we designed a parallelization strategy based on graph theory. The application results show that the proposed parallel approach to calculate flow accumulations on a GPU performs much faster than either sequential algorithms or other parallel GPU-based algorithms based on existing parallelization strategies.

Glacier topography and elevation changes derived from Pléiades sub-meter stereo images

NASA Astrophysics Data System (ADS)

Berthier, E.; Vincent, C.; Magnússon, E.; Gunnlaugsson, Á. Þ.; Pitte, P.; Le Meur, E.; Masiokas, M.; Ruiz, L.; Pálsson, F.; Belart, J. M. C.; Wagnon, P.

2014-12-01

In response to climate change, most glaciers are losing mass and hence contribute to sea-level rise. Repeated and accurate mapping of their surface topography is required to estimate their mass balance and to extrapolate/calibrate sparse field glaciological measurements. In this study we evaluate the potential of sub-meter stereo imagery from the recently launched Pléiades satellites to derive digital elevation models (DEMs) of glaciers and their elevation changes. Our five evaluation sites, where nearly simultaneous field measurements were collected, are located in Iceland, the European Alps, the central Andes, Nepal and Antarctica. For Iceland, the Pléiades DEM is also compared to a lidar DEM. The vertical biases of the Pléiades DEMs are less than 1 m if ground control points (GCPs) are used, but reach up to 7 m without GCPs. Even without GCPs, vertical biases can be reduced to a few decimetres by horizontal and vertical co-registration of the DEMs to reference altimetric data on ice-free terrain. Around these biases, the vertical precision of the Pléiades DEMs is ±1 m and even ±0.5 m on the flat glacier tongues (1σ confidence level). Similar precision levels are obtained in the accumulation areas of glaciers and in Antarctica. We also demonstrate the high potential of Pléiades DEMs for measuring seasonal, annual and multi-annual elevation changes with an accuracy of 1 m or better if cloud-free images are available. The negative region-wide mass balances of glaciers in the Mont-Blanc area (-1.04 ± 0.23 m a-1 water equivalent, w.e.) are revealed by differencing Satellite pour l'Observation de la Terre 5 (SPOT 5) and Pléiades DEMs acquired in August 2003 and 2012, confirming the accelerated glacial wastage in the European Alps.

Validation of the Omron MIT Elite blood pressure device in a pregnant population with large arm circumference.

PubMed

James, Lauren; Nzelu, Diane; Hay, Anna; Shennan, Andrew; Kametas, Nikos A

2017-04-01

The aim of this study was to evaluate the accuracy of the Omron MIT Elite automated device in pregnant women with an arm circumference of or above 32 cm, using the British Hypertension Society validation protocol. Blood pressure was measured sequentially in 46 women of any gestation requiring the use of a large cuff (arm circumference ≥32 cm) alternating between the mercury sphygmomanometer and the Omron MIT Elite device. The Omron MIT Elite achieved an overall D/D grade with a mean of the device-observer difference being 7.17±6.67 and 9.31±6.59 for systolic and diastolic blood pressure respectively. Interobserver accuracy was 94.6% for systolic and 95% for diastolic readings within 5 mmHg. The Omron MIT Elite overestimates blood pressure and has failed the British Hypertension Society protocol requirements. Therefore, it cannot be recommended for use in pregnant women with an arm circumference of or above 32 cm.

Advancements in Transmitters and Sensors for Biological Tissue Imaging in Magnetic Induction Tomography

PubMed Central

Zakaria, Zulkarnay; Rahim, Ruzairi Abdul; Mansor, Muhammad Saiful Badri; Yaacob, Sazali; Ayub, Nor Muzakkir Nor; Muji, Siti Zarina Mohd.; Rahiman, Mohd Hafiz Fazalul; Aman, Syed Mustafa Kamal Syed

2012-01-01

Magnetic Induction Tomography (MIT), which is also known as Electromagnetic Tomography (EMT) or Mutual Inductance Tomography, is among the imaging modalities of interest to many researchers around the world. This noninvasive modality applies an electromagnetic field and is sensitive to all three passive electromagnetic properties of a material that are conductivity, permittivity and permeability. MIT is categorized under the passive imaging family with an electrodeless technique through the use of excitation coils to induce an electromagnetic field in the material, which is then measured at the receiving side by sensors. The aim of this review is to discuss the challenges of the MIT technique and summarize the recent advancements in the transmitters and sensors, with a focus on applications in biological tissue imaging. It is hoped that this review will provide some valuable information on the MIT for those who have interest in this modality. The need of this knowledge may speed up the process of adopted of MIT as a medical imaging technology. PMID:22969341

Key role of lattice symmetry in the metal-insulator transition of NdNiO 3 films

DOE PAGES

Zhang, Jack Y.; Kim, Honggyu; Mikheev, Evgeny; ...

2016-04-01

Here, bulk NdNiO 3 exhibits a metal-to-insulator transition (MIT) as the temperature is lowered that is also seen in tensile strained films. In contrast, films that are under a large compressive strain typically remain metallic at all temperatures. To clarify the microscopic origins of this behavior, we use position averaged convergent beam electron diffraction in scanning transmission electron microscopy to characterize strained NdNiO 3 films both above and below the MIT temperature. We show that a symmetry lowering structural change takes place in case of the tensile strained film, which undergoes an MIT, but is absent in the compressively strainedmore » film. Using space group symmetry arguments, we show that these results support the bond length disproportionation model of the MIT in the rare-earth nickelates. Furthermore, the results provide insights into the non-Fermi liquid phase that is observed in films for which the MIT is absent.« less

Investigation on onset voltage and conduction channel temperature in voltage-induced metal-insulator transition of vanadium dioxide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yoon, Joonseok; Kim, Howon; Ju, Honglyoul, E-mail: tesl@yonsei.ac.kr

2016-03-28

The characteristics of onset voltages and conduction channel temperatures in the metal-insulator transition (MIT) of vanadium dioxide (VO{sub 2}) devices are investigated as a function of dimensions and ambient temperature. The MIT onset voltage varies from 18 V to 199 V as the device length increases from 5 to 80 μm at a fixed width of 100 μm. The estimated temperature at local conduction channel increases from 110 to 370 °C, which is higher than the MIT temperature (67 °C) of VO{sub 2}. A simple Joule-heating model is employed to explain voltage-induced MIT as well as to estimate temperatures of conduction channel appearing after MIT inmore » various-sized devices. Our findings on VO{sub 2} can be applied to micro- to nano-size tunable heating devices, e.g., microscale scanning thermal cantilevers and gas sensors.« less

Seasonal variabilty of surface velocities and ice discharge of Columbia Glacier, Alaska using high-resolution TanDEM-X satellite time series and NASA IceBridge data

NASA Astrophysics Data System (ADS)

Vijay, Saurabh; Braun, Matthias

2014-05-01

Columbia Glacier is a grounded tidewater glacier located on the south coast of Alaska. It has lost half of its volume during 1957-2007, more rapidly after 1980. It is now split into two branches, known as Main/East and West branch due to the dramatic retreat of ~ 23 km and calving of iceberg from its terminus in past few decades. In Alaska, a majority of the mass loss from glaciers is due to rapid ice flow and calving icebergs into tidewater and lacustrine environments. In addition, submarine melting and change in the frontal position can accelerate the ice flow and calving rate. We use time series of high-resolution TanDEM-X stripmap satellite imagery during 2011-2013. The active image of the bistatic TanDEM-X acquisitions, acquired over 11 or 22 day repeat intervals, are utilized to derive surface velocity fields using SAR intensity offset tracking. Due to the short temporal baselines, the precise orbit control and the high-resolution of the data, the accuracies of the velocity products are high. We observe a pronounce seasonal signal in flow velocities close to the glacier front of East/Main branch of Columbia Glacier. Maximum values at the glacier front reach up to 14 m/day were recorded in May 2012 and 12 m/day in June 2013. Minimum velocities at the glacier front are generally observed in September and October with lowest values below 2 m/day in October 2012. Months in between those dates show corresponding increase or deceleration resulting a kind of sinusoidal annual course of the surface velocity at the glacier front. The seasonal signal is consistently decreasing with the distance from the glacier front. At a distance of 17.5 km from the ice front, velocities are reduced to 2 m/day and almost no seasonal variability can be observed. We attribute these temporal and spatial variability to changes in the basal hydrology and lubrification of the glacier bed. Closure of the basal drainage system in early winter leads to maximum speeds while during a fully developed basal drainage system speeds are at their minimum. We also analyze the variation in conjunction with the prevailing meteorological conditions as well as changes in calving front position in order to exclude other potential influencing factors. In a second step, we also exploit TanDEM-X data to generate various digital elevation models (DEMs) at different time steps. The multi-temporal DEMs are used to estimate the difference in surface elevation and respective ice thickness changes. All TanDEM-X DEMs are well tied with a SPOT reference DEM. Errors are estimated over ice free moraines and rocky areas. The quality of the TanDEM-X DEMs on snow and ice covered areas are further assessed by a comparison to laser scanning data from NASA Icebridge campaigns. The time wise closest TanDEM-X DEMs were compared to the Icebridge tracks from winter and summer surveys in order to judge errors resulting from the radar penetration of the x/band radar signal into snow, ice and firn. The average differences between laser scanning and TanDEM-X in August, 2011 and March, 2012 are observed to be 8.48 m and 14.35 m respectively. Retreat rates of the glacier front are derived manually by digitizing the terminus position. By combining the data sets of ice velocity, ice thickness and the retreat rates at different time steps, we estimate the seasonal variability of the ice discharge of Columbia Glacier.

77 FR 2096 - Proposal Review Panel for Materials Research; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-13

... Engineering Center (MRSEC) at Massachusetts Institute of Technology (MIT) by the Division of Materials... 16, 2012 7:15 a.m.-8:15 a.m. Closed--Executive Session 8:15 a.m.-5 p.m. Open--Review of the MIT MRSEC... session 9 a.m.-10 a.m. Open--Review of the MIT MRSEC 10 a.m.-4:30 p.m. Closed--Executive Session, Report...

Minimally invasive thyroidectomy (MIT): indications and results.

PubMed

Docimo, Giovanni; Salvatore Tolone, Salvatore; Gili, Simona; d'Alessandro, A; Casalino, G; Brusciano, L; Ruggiero, Roberto; Docimo, Ludovico

2013-01-01

To establish if the indication for different approaches for thyroidectomy and the incision length provided by means of pre-operative assessment of gland volume and size of nodules resulted in safe and effective outcomes and in any notable aesthetic or quality-of-life impact on patients. Ninehundred eightytwo consecutive patients, undergoing total thyroidectomy, were enrolled. The thyroid volume and maximal nodule diameter were measured by means of ultrasounds. Based on ultrasounds findings, patients were divided into three groups: minimally invasive video assisted thyroidectomy (MIVAT), minimally invasive thyroidectomy (MIT) and conventional thyroidectomy (CT) groups. The data concerning the following parameters were collected: operative time, postoperative complications, postoperative pain and cosmetic results. The MIVAT group included 179 patients, MIT group included 592 patients and CT group included 211 patients. Incidence of complications did not differ significantly in each group. In MIVAT and MIT group, the perception of postoperative pain was less intense than CT group. The patients in the MIVAT (7±1.5) and MIT (8±2) groups were more satisfied with the cosmetic results than those in CT group (5±1.3) (p= <0.05). The MIT is a technique totally reproducible, and easily convertible to perform surgical procedures in respect of the patient, without additional complications, increased costs, and with better aesthetic results.

The Golden Age of Radio: Solid State's Debt to the Rad Lab

NASA Astrophysics Data System (ADS)

Martin, Joseph D.

2011-03-01

While MIT's Radiation Laboratory is rightly celebrated for its contributions to World War II radar research, its legacy extended beyond the war. The Rad Lab provided a model for interdisciplinary collaboration that continued to influence research at MIT in the post-war decades. The Rad Lab's institutional legacy--MIT's interdepartmental laboratories--drove the Institute's postwar research agenda. This talk examines how solid state physics research at MIT was shaped by a laboratory structure that encouraged cross-disciplinary collaboration. As the sub-discipline of solid state physics emerged through the late-1940s and 1950s, MIT was unique among universities in its laboratory structure, made possible by a large degree of government and military funding. Nonetheless, the manner in which MIT research groups from physics, chemistry, engineering, and metallurgy interfaced through the medium of solid state physics exemplified how the discipline of solid state physics came to be structured in the rest of the country. Through examining the Rad Lab's institutional legacy, I argue that World War II radar research, by establishing precedent for a particular mode of interdisciplinary collaboration, shaped the future structure of solid state research in the United States. Research supported by a grant-in-aid from the Friends of the Center for the History of Physics, American Institute of Physics.

Kompressionstherapie bei Patienten mit Ulcus cruris venosum.

PubMed

Dissemond, Joachim; Assenheimer, Bernd; Bültemann, Anke; Gerber, Veronika; Gretener, Silvia; Kohler-von Siebenthal, Elisabeth; Koller, Sonja; Kröger, Knut; Kurz, Peter; Läuchli, Severin; Münter, Christian; Panfil, Eva-Maria; Probst, Sebastian; Protz, Kerstin; Riepe, Gunnar; Strohal, Robert; Traber, Jürg; Partsch, Hugo

2016-11-01

Wund-D.A.CH. ist der Dachverband deutschsprachiger Fachgesellschaften, die sich mit den Thematiken der Wundbehandlung beschäftigen. Experten verschiedener Fachgesellschaften aus Deutschland, Österreich und der Schweiz haben nun einen aktuellen Konsens der Kompressionstherapie für Patienten mit Ulcus cruris venosum erstellt. In Europa ist das Ulcus cruris venosum eine der häufigsten Ursachen für chronische Wunden. Neben der konservativen und interventionellen Wund- und Venentherapie, ist die Kompressionstherapie die Basis der Behandlungsstrategien. Die Kompressionstherapie kann heute mit sehr unterschiedlichen Materialien und Systemen durchgeführt werden. Während in der Entstauungsphase insbesondere Verbände mit Kurzzugbinden oder Mehrkomponentensysteme zur Anwendung kommen, sind es anschließend überwiegend Ulkus-Strumpfsysteme. Eine weitere, bislang wenig verbreitete Alternative sind adaptive Kompressionsbandagen. Insbesondere für die Rezidivprophylaxe werden medizinische Kompressionsstrümpfe empfohlen. Durch die Vielzahl der heute zur Verfügung stehenden Behandlungsoptionen, kann für nahezu alle Patienten ein Konzept entwickelt werden, dass sich an den individuellen Bedürfnissen und Fähigkeiten orientiert und daher auch akzeptiert und durchgeführt wird. Die Kompressionstherapie ist für die Behandlung von Patienten mit Ulcus cruris venosum essentiell. In den letzten Jahren sind viele verschiedene Therapieoptionen verfügbar, die in den deutschsprachigen Ländern unterschiedlich angewendet oder durchgeführt werden. Daher soll dieser Expertenkonsens dazu beitragen, konkrete Empfehlungen für die praktische Durchführung der Kompressionstherapie von Patienten mit Ulcus cruris venosum darzustellen. © 2016 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

Binding of Substrates to the Central Pore of the Vps4 ATPase Is Autoinhibited by the Microtubule Interacting and Trafficking (MIT) Domain and Activated by MIT Interacting Motifs (MIMs).

PubMed

Han, Han; Monroe, Nicole; Votteler, Jörg; Shakya, Binita; Sundquist, Wesley I; Hill, Christopher P

2015-05-22

The endosomal sorting complexes required for transport (ESCRT) pathway drives reverse topology membrane fission events within multiple cellular pathways, including cytokinesis, multivesicular body biogenesis, repair of the plasma membrane, nuclear membrane vesicle formation, and HIV budding. The AAA ATPase Vps4 is recruited to membrane necks shortly before fission, where it catalyzes disassembly of the ESCRT-III lattice. The N-terminal Vps4 microtubule-interacting and trafficking (MIT) domains initially bind the C-terminal MIT-interacting motifs (MIMs) of ESCRT-III subunits, but it is unclear how the enzyme then remodels these substrates in response to ATP hydrolysis. Here, we report quantitative binding studies that demonstrate that residues from helix 5 of the Vps2p subunit of ESCRT-III bind to the central pore of an asymmetric Vps4p hexamer in a manner that is dependent upon the presence of flexible nucleotide analogs that can mimic multiple states in the ATP hydrolysis cycle. We also find that substrate engagement is autoinhibited by the Vps4p MIT domain and that this inhibition is relieved by binding of either Type 1 or Type 2 MIM elements, which bind the Vps4p MIT domain through different interfaces. These observations support the model that Vps4 substrates are initially recruited by an MIM-MIT interaction that activates the Vps4 central pore to engage substrates and generate force, thereby triggering ESCRT-III disassembly. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Monitoring of allograft vasculopathy by intravascular ultrasound one month and one year after heart transplantation: A single center study.

PubMed

Bedanova, Helena; Orban, Marek; Tretina, Martin; Fila, Petr; Horvath, Vladimir; Krejci, Jan; Nemec, Petr

2016-03-01

The aim of this trial was to use intravascular ultrasound (IVUS) to determine whether cardiac allograft vasculopathy (CAV) starts progressing during the first year after heart transplantation (HTx). We retrospectively analyzed 51 patients (11 women) who received heart transplants in our center between January 2010 and September 2013 and underwent coronary angiography as well as IVUS examination one month and one year after HTx. Patients with proven calcification and fibrotic plates in the IVUS examination one month after HTx constituted a group with defined donor-transmitted atherosclerosis (DTA). In patients without DTA, measurements of maximal intimal thickening (MIT) were made in two predetermined locations. Eight of the 51 patients had DTA, while 43 did not. These were divided based on maximal intimal thickness (MIT) into a group with MIT < 0.5 mm (27) and MIT ≥ 0.5 mm (16). No patient with MIT < 0.5 mm developed allograft vasculopathy within one year after HTx. CAV developed in three patients (P = 0.045) out of the 16 patients with MIT ≥ 0.5. In patients with DTA, a statistically significant deterioration in percent area stenosis (PAS) occurred in both artery sections (P = 0.01). Our trial showed that CAV progresses during the first year after HTx significantly more frequently in patients with DTA and MIT ≥ 0.5 mm. It is essential in these patients to implement an IVUS control examination one year after transplantation. The results can lead to a change in treatment strategy to prevent further progress of the disease.

Private-sector Support of Research at the Massachusetts Institute of Technology

NASA Astrophysics Data System (ADS)

Zuber, M. T.; Christy, M. D.

2016-12-01

In fiscal year 2016, 66% of MIT's external research support came from federal sources. This percentage is the lowest since federal funding of university research initiated circa World War II. The percentage has dropped precipitously since the financial crisis of 2008 and the advent of sequestration, and the most optimistic scenario in the near future is flat to mildly increasing federal investments in research. Of the one-third of MIT's research supported by non-federal sources, 18% comes from industry, and the remainder comes from foundations, non-profits, and state and foreign governments. The overwhelming majority of non-federal support is for applied rather than basic research. Non-federal support of research in the geosciences comes from all these sources. In accepting research support from industry MIT must balance the desires of faculty and research staff to work in collaboration with companies of their choosing, with the essential need to set conditions that ensure independent scholarship. Participation in research projects is at the discretion of the Principal Investigator, and must be fully consistent with MIT's non-discrimination and open access policies. In all research agreements, MIT requires that faculty, students and research staff are able to freely present and publish results. While MIT's research partners help to identify research areas of mutual interest and may consult on research as it moves forward, MIT faculty members, researchers, post-doctoral scholars and students retain control over the design and management of their research projects at all times. The Institute also requires the identification and management of any conflicts of interest.

Tunable metal-insulator transition in Nd{sub 1−x}Y{sub x}NiO{sub 3} (x = 0.3, 0.4) perovskites thin film at near room temperature

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shao, Tao; Qi, Zeming, E-mail: zmqi@ustc.edu.cn; Wang, Yuyin

2015-07-13

Metal-insulator transition (MIT) occurs due to the charge disproportionation and lattice distortions in rare-earth nickelates. Existing studies revealed that the MIT behavior of rare-earth nickelates is fairly sensitive to external stress/pressure, suggesting a viable route for MIT strain engineering. Unlike applying extrinsic strain, the MIT can also be modulated by through rare-earth cation mixing, which can be viewed as intrinsic quantum stress. We choose Nd{sub 1−X}Y{sub X}NiO{sub 3} (x = 0.3, 0.4) perovskites thin films as a prototype system to exhibit the tunable sharp MIT at near room temperature. By adjusting Y concentration, the transition temperature of the thin films can bemore » changed within the range of 340–360 K. X-ray diffraction, X-ray absorption fine structure (XAFS), and in situ infrared spectroscopy are employed to probe the structural and optical property variation affected by composition and temperature. The infrared transmission intensity decreases with temperature across the MIT, indicating a pronounced thermochromic effect. Meanwhile, the XAFS result exhibits that the crystal atomistic structure changes accompanying with the Y atoms incorporation and MIT phase transition. The heavily doped Y atoms result in the pre-edge peak descent and Ni-O bond elongation, suggesting an enhanced charge disproportionation effect and the weakening of hybridization between Ni-3d and O-2p orbits.« less

Binding of Substrates to the Central Pore of the Vps4 ATPase Is Autoinhibited by the Microtubule Interacting and Trafficking (MIT) Domain and Activated by MIT Interacting Motifs (MIMs)*

PubMed Central

Han, Han; Monroe, Nicole; Votteler, Jörg; Shakya, Binita; Sundquist, Wesley I.; Hill, Christopher P.

2015-01-01

The endosomal sorting complexes required for transport (ESCRT) pathway drives reverse topology membrane fission events within multiple cellular pathways, including cytokinesis, multivesicular body biogenesis, repair of the plasma membrane, nuclear membrane vesicle formation, and HIV budding. The AAA ATPase Vps4 is recruited to membrane necks shortly before fission, where it catalyzes disassembly of the ESCRT-III lattice. The N-terminal Vps4 microtubule-interacting and trafficking (MIT) domains initially bind the C-terminal MIT-interacting motifs (MIMs) of ESCRT-III subunits, but it is unclear how the enzyme then remodels these substrates in response to ATP hydrolysis. Here, we report quantitative binding studies that demonstrate that residues from helix 5 of the Vps2p subunit of ESCRT-III bind to the central pore of an asymmetric Vps4p hexamer in a manner that is dependent upon the presence of flexible nucleotide analogs that can mimic multiple states in the ATP hydrolysis cycle. We also find that substrate engagement is autoinhibited by the Vps4p MIT domain and that this inhibition is relieved by binding of either Type 1 or Type 2 MIM elements, which bind the Vps4p MIT domain through different interfaces. These observations support the model that Vps4 substrates are initially recruited by an MIM-MIT interaction that activates the Vps4 central pore to engage substrates and generate force, thereby triggering ESCRT-III disassembly. PMID:25833946

Autolytic activity of human calpain 7 is enhanced by ESCRT-III-related protein IST1 through MIT-MIM interaction.

PubMed

Osako, Yohei; Maemoto, Yuki; Tanaka, Ryohei; Suzuki, Hironori; Shibata, Hideki; Maki, Masatoshi

2010-11-01

Calpain 7, a mammalian ortholog of yeast Cpl1/Rim13 and fungal PalB, is an atypical calpain that lacks a penta-EF-hand domain. Previously, we reported that a region containing a tandem repeat of microtubule-interacting and transport (MIT) domains in calpain 7 interacts with a subset of endosomal sorting complex required for transport (ESCRT)-III-related proteins, suggesting involvement of calpain 7 in the ESCRT system. Although yeast and fungal calpains are thought to be involved in alkaline adaptation via limited proteolysis of specific transcription factors, proteolytic activity of calpain 7 has not been demonstrated yet. In this study, we investigated the interaction between calpain 7 and a newly reported ESCRT-III family member, increased sodium tolerance-1 (IST1), which possesses two different types of MIT-interacting motifs (MIM1 and MIM2). We found that glutathione-S-transferase (GST)-fused tandem MIT domains of calpain 7 (calpain 7MIT) pulled down FLAG-tagged IST1 expressed in HEK293T cells. Coimmunoprecipitation assays with various deletion or point mutants of epitope-tagged calpain 7 and IST1 revealed that both repetitive MIT domains and MIMs are required for efficient interaction. Direct MIT-MIM binding was confirmed by a pulldown experiment with GST-fused IST1 MIM and purified recombinant calpain 7MIT. Furthermore, we found that the GST-MIM protein enhances the autolysis of purified Strep-tagged monomeric green fluorescent protein (mGFP)-fused calpain 7 (mGFP-calpain 7-Strep). The autolysis was almost completely abolished by 10 mmN-ethylmaleimide but only partially inhibited by 1 mm leupeptin or E-64. The putative catalytic Cys290-substituted mutant (mGFP-calpain 7(C290S)-Strep) showed no autolytic activity. These results demonstrate for the first time that human calpain 7 is proteolytically active, and imply that calpain 7 is activated in the ESCRT system. © 2010 The Authors Journal compilation © 2010 FEBS.

Intraläsionale Therapie niedrig maligner primär kutaner B-Zell-Lymphome mit Anti-CD20-Antikörper: Nebenwirkungen korrelieren mit gutem klinischen Ansprechen.

PubMed

Eberle, Franziska C; Holstein, Julia; Scheu, Alexander; Fend, Falko; Yazdi, Amir S

2017-03-01

Die intraläsionale Gabe von Anti-CD20-Antikörpern (Rituximab) wurde als effektive Therapieoption für Patienten mit niedrig malignen primär kutanen B-Zell-Lymphomen beschrieben. Bis heute wurden allerdings keine Parameter identifiziert, welche reproduzierbar ein gutes klinisches Ansprechen dieser Therapie vorhersagen. Ziel dieser Studie ist, sowohl das klinische Ansprechen und die unerwünschten Nebenwirkungen als auch die Patientenwahrnehmung hinsichtlich intraläsionaler Injektionen von anti-CD20-Antikörpern zur Behandlung indolenter primär kutaner B-Zell-Lymphome im Vergleich mit anderen Therapien zu evaluieren. Elf Patienten mit einem primär kutanen B-Zell-Lymphom, namentlich primär kutanes Keimzentrumslymphom (n = 9) und primär kutanes Marginalzonenlymphom (n = 2), welche mittels intraläsionalem Anti-CD20-Antikörper behandelt wurden, wurden retrospektiv evaluiert hinsichtlich der Ansprechrate und unerwünschter Nebenwirkungen sowie in Bezug auf deren Selbsteinschätzung dieser und anderer Therapien des primär kutanen B-Zell-Lymphoms. Patienten, deren primär kutanes B-Zell-Lymphom mittels intraläsionaler Gabe von Anti-CD20-Antikörper behandelt wurde, zeigten ein komplettes oder partielles Ansprechen in 45 % beziehungsweise 27 % aller Patienten. Speziell Patienten mit grippeähnlichen Symptomen nach erfolgter Injektion zeigten ein gutes Ansprechen. Die Mehrheit der Patienten empfand die Therapie mit Rituximab als die beste Therapie im Vergleich zu anderen Therapien wie beispielsweise chirurgische Exzision oder Radiotherapie. Intraläsionales Rituximab ist eine effektive Therapie mit hoher Patientenzufriedenheit. Starke therapiebedingte Nebenwirkungen wie Fieber, Schüttelfrost und Kopfschmerzen nach Gabe von Rituximab könnten als Indikator für gute Wirksamkeit dienen. © 2017 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

MitProNet: A Knowledgebase and Analysis Platform of Proteome, Interactome and Diseases for Mammalian Mitochondria

PubMed Central

Mao, Song; Chai, Xiaoqiang; Hu, Yuling; Hou, Xugang; Tang, Yiheng; Bi, Cheng; Li, Xiao

2014-01-01

Mitochondrion plays a central role in diverse biological processes in most eukaryotes, and its dysfunctions are critically involved in a large number of diseases and the aging process. A systematic identification of mitochondrial proteomes and characterization of functional linkages among mitochondrial proteins are fundamental in understanding the mechanisms underlying biological functions and human diseases associated with mitochondria. Here we present a database MitProNet which provides a comprehensive knowledgebase for mitochondrial proteome, interactome and human diseases. First an inventory of mammalian mitochondrial proteins was compiled by widely collecting proteomic datasets, and the proteins were classified by machine learning to achieve a high-confidence list of mitochondrial proteins. The current version of MitProNet covers 1124 high-confidence proteins, and the remainders were further classified as middle- or low-confidence. An organelle-specific network of functional linkages among mitochondrial proteins was then generated by integrating genomic features encoded by a wide range of datasets including genomic context, gene expression profiles, protein-protein interactions, functional similarity and metabolic pathways. The functional-linkage network should be a valuable resource for the study of biological functions of mitochondrial proteins and human mitochondrial diseases. Furthermore, we utilized the network to predict candidate genes for mitochondrial diseases using prioritization algorithms. All proteins, functional linkages and disease candidate genes in MitProNet were annotated according to the information collected from their original sources including GO, GEO, OMIM, KEGG, MIPS, HPRD and so on. MitProNet features a user-friendly graphic visualization interface to present functional analysis of linkage networks. As an up-to-date database and analysis platform, MitProNet should be particularly helpful in comprehensive studies of complicated biological mechanisms underlying mitochondrial functions and human mitochondrial diseases. MitProNet is freely accessible at http://bio.scu.edu.cn:8085/MitProNet. PMID:25347823

Analytische Geometrie

NASA Astrophysics Data System (ADS)

Kemnitz, Arnfried

Der Grundgedanke der Analytischen Geometrie besteht darin, dass geometrische Untersuchungen mit rechnerischen Mitteln geführt werden. Geometrische Objekte werden dabei durch Gleichungen beschrieben und mit algebraischen Methoden untersucht.

Gold silver alloy nanoparticles (GSAN): an imaging probe for breast cancer screening with dual-energy mammography or computed tomography

NASA Astrophysics Data System (ADS)

Naha, Pratap C.; Lau, Kristen C.; Hsu, Jessica C.; Hajfathalian, Maryam; Mian, Shaameen; Chhour, Peter; Uppuluri, Lahari; McDonald, Elizabeth S.; Maidment, Andrew D. A.; Cormode, David P.

2016-07-01

Earlier detection of breast cancer reduces mortality from this disease. As a result, the development of better screening techniques is a topic of intense interest. Contrast-enhanced dual-energy mammography (DEM) is a novel technique that has improved sensitivity for cancer detection. However, the development of contrast agents for this technique is in its infancy. We herein report gold-silver alloy nanoparticles (GSAN) that have potent DEM contrast properties and improved biocompatibility. GSAN formulations containing a range of gold : silver ratios and capped with m-PEG were synthesized and characterized using various analytical methods. DEM and computed tomography (CT) phantom imaging showed that GSAN produced robust contrast that was comparable to silver alone. Cell viability, reactive oxygen species generation and DNA damage results revealed that the formulations with 30% or higher gold content are cytocompatible to Hep G2 and J774A.1 cells. In vivo imaging was performed in mice with and without breast tumors. The results showed that GSAN produce strong DEM and CT contrast and accumulated in tumors. Furthermore, both in vivo imaging and ex vivo analysis indicated the excretion of GSAN via both urine and feces. In summary, GSAN produce strong DEM and CT contrast, and has potential for both blood pool imaging and for breast cancer screening.Earlier detection of breast cancer reduces mortality from this disease. As a result, the development of better screening techniques is a topic of intense interest. Contrast-enhanced dual-energy mammography (DEM) is a novel technique that has improved sensitivity for cancer detection. However, the development of contrast agents for this technique is in its infancy. We herein report gold-silver alloy nanoparticles (GSAN) that have potent DEM contrast properties and improved biocompatibility. GSAN formulations containing a range of gold : silver ratios and capped with m-PEG were synthesized and characterized using various analytical methods. DEM and computed tomography (CT) phantom imaging showed that GSAN produced robust contrast that was comparable to silver alone. Cell viability, reactive oxygen species generation and DNA damage results revealed that the formulations with 30% or higher gold content are cytocompatible to Hep G2 and J774A.1 cells. In vivo imaging was performed in mice with and without breast tumors. The results showed that GSAN produce strong DEM and CT contrast and accumulated in tumors. Furthermore, both in vivo imaging and ex vivo analysis indicated the excretion of GSAN via both urine and feces. In summary, GSAN produce strong DEM and CT contrast, and has potential for both blood pool imaging and for breast cancer screening. Electronic supplementary information (ESI) available: Reactive oxygen species generation and DNA damage methods, stability of GSAN in PBS, step phantom images and a DEM image of a gold nanoparticle phantom, GSAN CT phantom results. See DOI: 10.1039/c6nr02618d

Vertical Accuracy Assessment of 30-M Resolution Alos, Aster, and Srtm Global Dems Over Northeastern Mindanao, Philippines

NASA Astrophysics Data System (ADS)

Santillan, J. R.; Makinano-Santillan, M.

2016-06-01

The ALOS World 3D - 30 m (AW3D30), ASTER Global DEM Version 2 (GDEM2), and SRTM-30 m are Digital Elevation Models (DEMs) that have been made available to the general public free of charge. An important feature of these DEMs is their unprecedented horizontal resolution of 30-m and almost global coverage. The very recent release of these DEMs, particularly AW3D30 and SRTM- 30 m, calls for opportunities for the conduct of localized assessment of the DEM's quality and accuracy to verify their suitability for a wide range of applications in hydrology, geomorphology, archaelogy, and many others. In this study, we conducted a vertical accuracy assessment of these DEMs by comparing the elevation of 274 control points scattered over various sites in northeastern Mindanao, Philippines. The elevations of these control points (referred to the Mean Sea Level, MSL) were obtained through 3rd order differential levelling using a high precision digital level, and their horizontal positions measured using a global positioning system (GPS) receiver. These control points are representative of five (5) land-cover classes namely brushland (45 points), built-up (32), cultivated areas (97), dense vegetation (74), and grassland (26). Results showed that AW3D30 has the lowest Root Mean Square Error (RMSE) of 5.68 m, followed by SRTM-30 m (RMSE = 8.28 m), and ASTER GDEM2 (RMSE = 11.98 m). While all the three DEMs overestimated the true ground elevations, the mean and standard deviations of the differences in elevations were found to be lower in AW3D30 compared to SRTM-30 m and ASTER GDEM2. The superiority of AW3D30 over the other two DEMS was also found to be consistent even under different landcover types, with AW3D30's RMSEs ranging from 4.29 m (built-up) to 6.75 m (dense vegetation). For SRTM-30 m, the RMSE ranges from 5.91 m (built-up) to 10.42 m (brushland); for ASTER GDEM2, the RMSE ranges from 9.27 m (brushland) to 14.88 m (dense vegetation). The results of the vertical accuracy assessment suggest that the AW3D30 is more accurate than SRTM-30 m and ASTER GDEM2, at least for the areas considered in this study. On the other hand, the tendencies of the three DEMs to overestimate true ground elevation can be considered an important finding that users of the DEMs in the Philippines should be aware of, and must be considered into decisions regarding use of these data products in various applications.

Improving the Effectiveness of Speaker Verification Domain Adaptation With Inadequate In-Domain Data

DTIC Science & Technology

2017-08-20

Improving the Effectiveness of Speaker Verification Domain Adaptation With Inadequate In-Domain Data Bengt J. Borgström1, Elliot Singer1, Douglas...ll.mit.edu.edu, dar@ll.mit.edu, es@ll.mit.edu, omid.sadjadi@nist.gov Abstract This paper addresses speaker verification domain adaptation with...contain speakers with low channel diversity. Existing domain adaptation methods are reviewed, and their shortcomings are discussed. We derive an

Mitochondrial-type hsp70 genes of the amitochondriate protists, Giardia intestinalis, Entamoeba histolytica and two microsporidians☆

PubMed Central

Arisue, Nobuko; Sánchez, Lidya B.; Weiss, Louis M.; Müller, Miklós; Hashimoto, Tetsuo

2011-01-01

Genes encoding putative mitochondrial-type heat shock protein 70 (mit-hsp70) were isolated and sequenced from amitochondriate protists, Giardia intestinalis, Entamoeba histolytica, and two microsporidians, Encephalitozoon hellem and Glugea plecoglossi. The deduced mit-hsp70 sequences were analyzed by sequence alignments and phylogenetic reconstructions. The mit-hsp70 sequence of these four amitochondriate protists were divergent from other mit-hsp70 sequences of mitochondriate eukaryotes. However, all of these sequences were clearly located within a eukaryotic mitochondrial clade in the tree including various type hsp70 sequences, supporting the emerging notion that none of these amitochondriate lineages are primitively amitochodrial, but lost their mitochondria secondarily in their evolutionary past. PMID:11880223

Development and evaluation of form three mathematics i-Think module (Mi-T3) on algebraic formulae topic

NASA Astrophysics Data System (ADS)

Sam, Sazilah; Abdullah, Mohd Faizal Nizam Lee

2017-05-01

This article introduces the Form Three Mathematics i-Think Module (Mi-T3). The main objective of this Mi-T3 is to assist form three students develop their higher order thinking skills (HOTS). The Sidek Module Development Model (SMDM) and eight innovative thinking maps (i-Think) were applied as a guideline in developing Mi-T3. A validation stage was carried out by eight experts, and content validation achievement more than 90% obtained. A group of form three students and teachers was piloted to check the module's reliability through one to one and small group evaluation and Cronbach Alpha more than 0.90 was obtained. Implications of the study are discussed in this article.

`Dem DEMs: Comparing Methods of Digital Elevation Model Creation

NASA Astrophysics Data System (ADS)

Rezza, C.; Phillips, C. B.; Cable, M. L.

2017-12-01

Topographic details of Europa's surface yield implications for large-scale processes that occur on the moon, including surface strength, modification, composition, and formation mechanisms for geologic features. In addition, small scale details presented from this data are imperative for future exploration of Europa's surface, such as by a potential Europa Lander mission. A comparison of different methods of Digital Elevation Model (DEM) creation and variations between them can help us quantify the relative accuracy of each model and improve our understanding of Europa's surface. In this work, we used data provided by Phillips et al. (2013, AGU Fall meeting, abs. P34A-1846) and Schenk and Nimmo (2017, in prep.) to compare DEMs that were created using Ames Stereo Pipeline (ASP), SOCET SET, and Paul Schenk's own method. We began by locating areas of the surface with multiple overlapping DEMs, and our initial comparisons were performed near the craters Manannan, Pwyll, and Cilix. For each region, we used ArcGIS to draw profile lines across matching features to determine elevation. Some of the DEMs had vertical or skewed offsets, and thus had to be corrected. The vertical corrections were applied by adding or subtracting the global minimum of the data set to create a common zero-point. The skewed data sets were corrected by rotating the plot so that it had a global slope of zero and then subtracting for a zero-point vertical offset. Once corrections were made, we plotted the three methods on one graph for each profile of each region. Upon analysis, we found relatively good feature correlation between the three methods. The smoothness of a DEM depends on both the input set of images and the stereo processing methods used. In our comparison, the DEMs produced by SOCET SET were less smoothed than those from ASP or Schenk. Height comparisons show that ASP and Schenk's model appear similar, alternating in maximum height. SOCET SET has more topographic variability due to its decreased smoothing, which is borne out by preliminary offset calculations. In the future, we plan to expand upon this preliminary work with more regions of Europa, continue quantifying the height differences and relative accuracy of each method, and generate more DEMs to expand our available comparison regions.

High Resolution Airborne InSAR DEM of Bagley Ice Valley, South-central Alaska: Geodetic Validation with Airborne Laser Altimeter Data

NASA Astrophysics Data System (ADS)

Muskett, R. R.; Lingle, C. S.; Echelmeyer, K. A.; Valentine, V. B.; Elsberg, D.

2001-12-01

Bagley Ice Valley, in the St. Elias and Chugach Mountains of south-central Alaska, is an integral part of the largest connected glacierized terrain on the North American continent. From the flow divide between Mt. Logan and Mt. St. Elias, Bagley Ice Valley flows west-northwest for some 90 km down a slope of less than 1o, at widths up to 15 km, to a saddle-gap where it turns south-west to become Bering Glacier. During 4-13 September 2000, an airborne survey of Bagley Ice Valley was performed by Intermap Technologies, Inc., using their Star-3i X-band SAR interferometer. The resulting digital elevation model (DEM) covers an area of 3243 km2. The DEM elevations are orthometric heights, in meters above the EGM96 geoid. The horizontal locations of the 10-m postings are with respect to the WGS84 ellipsoid. On 26 August 2000, 9 to 18 days prior to the Intermap Star-3i survey, a small-aircraft laser altimeter profile was acquired along the central flow line for validation. The laser altimeter data consists of elevations above the WGS84 ellipsoid and orthometric heights above GEOID99-Alaska. Assessment of the accuracy of the Intermap Star-3i DEM was made by comparison of both the DEM orthometric heights and elevations above the WGS84 ellipsoid with the laser altimeter data. Comparison of the orthometric heights showed an average difference of 5.4 +/- 1.0 m (DEM surface higher). Comparison of elevations above the WGS84 ellipsoid showed an average difference of -0.77 +/- 0.93 m (DEM surface lower). This indicates that the X-band Star-3i interferometer was penetrating the glacier surface by an expected small amount. The WGS84 comparison is well within the 3 m RMS accuracy quoted for GT-3 DEM products. Snow accumulation may have occurred, however, on Bagley Ice Valley between 26 August and 4-13 September 2000. This will be estimated using a mass balance model and used to correct the altimeter-derived surface heights. The new DEM of Bagley Ice Valley will provide a reference surface of high accuracy for glaciological and geodetic research using ICEsat and small-aircraft laser altimeter profiling of this glaciologically important region of south-central Alaska.

Comprehensive analysis of a long noncoding RNA-associated competing endogenous RNA network in colorectal cancer.

PubMed

Fan, Qiaowei; Liu, Bingrong

2018-01-01

This study was aimed to develop a lncRNA-associated competing endogenous RNA (ceRNA) network to provide further understanding of the ceRNA regulatory mechanism and pathogenesis in colorectal cancer (CRC). Expression profiles of mRNAs, lncRNAs, and miRNAs, and clinical information for CRC patients were obtained from The Cancer Genome Atlas. The differentially expressed mRNAs, lncRNAs, and miRNAs (referred to as "DEmRNAs", "DElncRNAs", and "DEmiRNAs", respectively) were screened out between 539 CRC samples and 11 normal samples. The interactions between DElncRNAs and DEmiRNAs were predicted by miRcode. The DEmRNAs targeted by the DEmiRNAs were retrieved according to TargetScan, miRTar-Base, and miRDB. The lncRNA-miRNA-mRNA ceRNA network was constructed based on the DEmiRNA-DElncRNA and DEmiRNA-DEmRNA interactions. Functional enrichment analysis revealed the biological processes and pathways of DEmRNAs involved in the development of CRC. Key lncRNAs were further analyzed for their associations with overall survival and clinical features of CRC patients. A total of 1,767 DEmRNAs, 608 DElncRNAs, and 283 DEmiRNAs were identified as CRC-specific RNAs. Three hundred eighty-two DEmiRNA-DElncRNA interactions and 68 DEmiRNA-DEmRNA interactions were recognized according to the relevant databases. The lncRNA-miRNA-mRNA ceRNA network was constructed using 25 DEmiRNAs, 52 DEmRNAs, and 64 DElncRNAs. Two DElncRNAs, five DEmiRNAs, and six DEmRNAs were demonstrated to be related to the prognosis of CRC patients. Four DElncRNAs were found to be associated with clinical features. Twenty-eight Gene Ontology terms and 10 Kyoto Encyclopedia of Genes and Genomes pathways were found to be significantly enriched by the DEmRNAs in the ceRNA network. Our results showed cancer-specific mRNA, lncRNA, and miRNA expression patterns and enabled us to construct an lncRNA-associated ceRNA network that provided new insights into the molecular mechanisms of CRC. Key RNA transcripts related to the overall survival and clinical features were also found with promising potential as biomarkers for diagnosis, survival prediction, and classification of CRC.

Sediment delivery estimates in water quality models altered by resolution and source of topographic data.

PubMed

Beeson, Peter C; Sadeghi, Ali M; Lang, Megan W; Tomer, Mark D; Daughtry, Craig S T

2014-01-01

Moderate-resolution (30-m) digital elevation models (DEMs) are normally used to estimate slope for the parameterization of non-point source, process-based water quality models. These models, such as the Soil and Water Assessment Tool (SWAT), use the Universal Soil Loss Equation (USLE) and Modified USLE to estimate sediment loss. The slope length and steepness factor, a critical parameter in USLE, significantly affects sediment loss estimates. Depending on slope range, a twofold difference in slope estimation potentially results in as little as 50% change or as much as 250% change in the LS factor and subsequent sediment estimation. Recently, the availability of much finer-resolution (∼3 m) DEMs derived from Light Detection and Ranging (LiDAR) data has increased. However, the use of these data may not always be appropriate because slope values derived from fine spatial resolution DEMs are usually significantly higher than slopes derived from coarser DEMs. This increased slope results in considerable variability in modeled sediment output. This paper addresses the implications of parameterizing models using slope values calculated from DEMs with different spatial resolutions (90, 30, 10, and 3 m) and sources. Overall, we observed over a 2.5-fold increase in slope when using a 3-m instead of a 90-m DEM, which increased modeled soil loss using the USLE calculation by 130%. Care should be taken when using LiDAR-derived DEMs to parameterize water quality models because doing so can result in significantly higher slopes, which considerably alter modeled sediment loss. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Thermodynamics of supra-arcade downflows in solar flares

NASA Astrophysics Data System (ADS)

Chen, Xin; Liu, Rui; Deng, Na; Wang, Haimin

2017-10-01

Context. Supra-arcade downflows (SADs) have been frequently observed during the gradual phase of solar flares near the limb. In coronal emission lines sensitive to flaring plasmas, they appear as tadpole-like dark voids against the diffuse fan-shaped "haze" above, flowing toward the well-defined flare arcade. Aims: We aim to investigate the evolution of SADs' thermal properties, and to shed light on the formation mechanism and physical processes of SADs. Methods: We carefully studied several selected SADs from two flare events and calculated their differential emission measures (DEMs) as well as DEM-weighted temperatures using data obtained by the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamic Observatory. Results: Our analysis shows that SADs are associated with a substantial decrease in DEM above 4 MK, which is 1-3 orders of magnitude smaller than the surrounding haze as well as the region before or after the passage of SADs, but comparable to the quiet corona. There is no evidence for the presence of the SAD-associated hot plasma (>20 MK) in the AIA data, and this decrease in DEM does not cause any significant change in the DEM distribution as well as the DEM-weighted temperature, which supports this idea that SADs are density depletion. This depression in DEM rapidly recovers in the wake of the SADs studied, generally within a few minutes, suggesting that they are discrete features. In addition, we found that SADs in one event are spatio-temporally associated with the successive formation of post-flare loops along the flare arcade. Movies associated to Figs. A.1 and A.2 are available at http://www.aanda.org

Evaluation of different digital elevation models for analyzing drainage morphometric parameters in a mountainous terrain: a case study of the Supin-Upper Tons Basin, Indian Himalayas.

PubMed

Das, Sayantan; Patel, Priyank Pravin; Sengupta, Somasis

2016-01-01

With myriad geospatial datasets now available for terrain information extraction and particularly streamline demarcation, there arises questions regarding the scale, accuracy and sensitivity of the initial dataset from which these aspects are derived, as they influence all other parameters computed subsequently. In this study, digital elevation models (DEM) derived from Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER V2), Shuttle Radar Topography Mission (SRTM V4, C-Band, 3 arc-second), Cartosat -1 (CartoDEM 1.0) and topographical maps (R.F. 1:250,000 and 1:50,000), have been used to individually extract and analyze the relief, surface, size, shape and texture properties of a mountainous drainage basin. Nestled inside a mountainous setting, the basin is a semi-elongated one with high relief ratio (>90), steep slopes (25°-30°) and high drainage density (>3.5 km/sq km), as computed from the different DEMs. The basin terrain and stream network is extracted from each DEM, whose morphometric attributes are compared with the surveyed stream networks present in the topographical maps, with resampling of finer DEM datasets to coarser resolutions, to reduce scale-implications during the delineation process. Ground truth verifications for altitudinal accuracy have also been done by a GPS survey. DEMs derived from the 1:50,000 topographical map and ASTER GDEM V2 data are found to be more accurate and consistent in terms of absolute accuracy, than the other generated or available DEM data products, on basis of the morphometric parameters extracted from each. They also exhibit a certain degree of proximity to the surveyed topographical map.

Sedimentary Environments Mapping in the Yellow Sea Using TanDEM-X and Optic Satellites

NASA Astrophysics Data System (ADS)

Ryu, J. H.; Lee, Y. K.; Kim, S. W.

2017-12-01

Due to land reclamation and dredging, 57% of China's coastal wetlands have disappeared since the 1950s, and the total area of tidal flats in South Korea decreased from approximately 2,800km2 in 1990 to 2392km2 in 2005(Qiu, 2011 and MLTM, 2010). Intertidal DEM and sedimentary facies are useful for understanding intertidal functions and monitoring their response to natural and anthropogenic actions. Highly accurate intertidal DEMs with 5-m resolution were generated based on the TanDEM-X interferometric SAR (InSAR) technique because TanDEM-X allows the acquisition of the coherent InSAR pairs with no time lag or approximately 10-second temporal baseline between master and slave SAR image. We successfully generated intertidal zone DEMs with 5-7-m spatial resolutions and interferometric height accuracies better than 0.15 m for three representative tidal flats on the west coast of the Korean Peninsula and one site of chinese coastal region in the Yellow Sea. Surface sediment classification based on remotely sensed data must circumspectly consider an effective critical grain size, water content, local topography, and intertidal structures. The earlier studies have some limitation that the classification map is not considered to analysis various environmental conditions. Therefore, the purpose of this study was minutely to mapping the surface sedimentary facies by analyzing the tidal channel, topography with multi-sensor remotely sensed data and in-situ data.

Geometric correction and digital elevation extraction using multiple MTI datasets

USGS Publications Warehouse

Mercier, Jeffrey A.; Schowengerdt, Robert A.; Storey, James C.; Smith, Jody L.

2007-01-01

Digital Elevation Models (DEMs) are traditionally acquired from a stereo pair of aerial photographs sequentially captured by an airborne metric camera. Standard DEM extraction techniques can be naturally extended to satellite imagery, but the particular characteristics of satellite imaging can cause difficulties. The spacecraft ephemeris with respect to the ground site during image collects is the most important factor in the elevation extraction process. When the angle of separation between the stereo images is small, the extraction process typically produces measurements with low accuracy, while a large angle of separation can cause an excessive number of erroneous points in the DEM from occlusion of ground areas. The use of three or more images registered to the same ground area can potentially reduce these problems and improve the accuracy of the extracted DEM. The pointing capability of some sensors, such as the Multispectral Thermal Imager (MTI), allows for multiple collects of the same area from different perspectives. This functionality of MTI makes it a good candidate for the implementation of a DEM extraction algorithm using multiple images for improved accuracy. Evaluation of this capability and development of algorithms to geometrically model the MTI sensor and extract DEMs from multi-look MTI imagery are described in this paper. An RMS elevation error of 6.3-meters is achieved using 11 ground test points, while the MTI band has a 5-meter ground sample distance.

Comparison of elevation derived from insar data with dem from topography map in Son Dong, Bac Giang, Viet Nam

NASA Astrophysics Data System (ADS)

Nguyen, Duy

2012-07-01

Digital Elevation Models (DEMs) are used in many applications in the context of earth sciences such as in topographic mapping, environmental modeling, rainfall-runoff studies, landslide hazard zonation, seismic source modeling, etc. During the last years multitude of scientific applications of Synthetic Aperture Radar Interferometry (InSAR) techniques have evolved. It has been shown that InSAR is an established technique of generating high quality DEMs from space borne and airborne data, and that it has advantages over other methods for the generation of large area DEM. However, the processing of InSAR data is still a challenging task. This paper describes InSAR operational steps and processing chain for DEM generation from Single Look Complex (SLC) SAR data and compare a satellite SAR estimate of surface elevation with a digital elevation model (DEM) from Topography map. The operational steps are performed in three major stages: Data Search, Data Processing, and product Validation. The Data processing stage is further divided into five steps of Data Pre-Processing, Co-registration, Interferogram generation, Phase unwrapping, and Geocoding. The Data processing steps have been tested with ERS 1/2 data using Delft Object-oriented Interferometric (DORIS) InSAR processing software. Results of the outcome of the application of the described processing steps to real data set are presented.

A comparison of screw insertion torque and pullout strength.

PubMed

Ricci, William M; Tornetta, Paul; Petteys, Timothy; Gerlach, Darin; Cartner, Jacob; Walker, Zakiyyah; Russell, Thomas A

2010-06-01

Pullout strength of screws is a parameter used to evaluate plate screw fixation strength. However, screw fixation strength may be more closely related to its ability to generate sufficient insertion because stable nonlocked plate-screw fracture fixation requires sufficient compression between plate and bone such that no motion occurs between the plate and bone under physiological loads. Compression is generated by tightening of screws. In osteoporotic cancellous bone, sufficient screw insertion torque may not be generated before screw stripping. The effect of screw thread pitch on generation of maximum insertion torque (MIT) and pullout strength (POS) was investigated in an osteoporotic cancellous bone model and the relationship between MIT and POS was analyzed. Stainless steel screws with constant major (5.0 mm) and minor (2.7 mm) diameters but with varying thread pitches (1, 1.2, 1.5, 1.6, and 1.75 mm) were tested for MIT and POS in a validated osteoporotic surrogate for cancellous bone (density of 160 kg/m(3) [10 lbs/ft(3)]). MIT was measured with a torque-measuring hex driver for screws inserted through a one-third tubular plate. POS was measured after insertion of screws to a depth of 20 mm based on the Standard Specification and Test Methods for Metallic Medical Bone Screws (ASTM F 543-07). Five screws were tested for each failure mode and screw design. The relationship between MIT and compressive force between the plate and bone surrogate was evaluated using pressure-sensitive film. There was a significant difference in mean MIT based on screw pitch (P < 0.0001), whereas POS did not show statistically significant differences among the different screw pitches (P = 0.052). Small screw pitches (1.0 mm and 1.2 mm) had lower MIT and were distinguished from large pitches (1.5 mm, 1.6 mm, and the 1.75 mm) with higher MIT. For POS, only the 1-mm and 1.6-mm pitch screws were found to be different from each other. Linear regression analysis of MIT revealed a moderate correlation to the screw pitch (R(2) = 0.67, P < 0.0001), whereas the analysis of POS suggested no correlation to the screw pitch (R(2) = 0.28, P = 0.006). Pearson correlation analysis indicated no correlation between MIT and POS (P = 0.069, r = -0.37). A linear relationship of increased compression between the plate and bone surrogate was found for increasing screw torque (R(2) = 0.97). These results indicate that the ability of different screw designs to generate high screw insertion torque in a model of osteoporotic cancellous bone is unrelated to their pullout strength. Therefore, extrapolation of results for POS to identify optimal screw design for osteoporotic bone may not be valid. Screw designs that optimize MIT should be sought for fixation in osteoporotic bone.

Dynamical Thermal Structure of Super-arcade Downflows in Solar Flares

NASA Astrophysics Data System (ADS)

Chen, Xin; Liu, Rui; Deng, Na; Wang, Haimin

2015-04-01

Super­-arcade downflows (SADs) have been frequently observed during the gradual phase of flares near the limb. In coronal emission lines sensitive to flaring plasmas, they appear as tadpole-like dark voids against the bright fan-shape “haze” above the well-defined flare arcade and flow toward the arcade. We carefully studied several selected SADs from two flare events using data observed by Solar Dynamic Observatory / Atmospheric Imaging Assembly and calculated their differential emission measures (DEMs) as well as the DEM-weighted temperature. Our analysis shows that SADs are associated with a substantially decreased DEMs, by 1~3 order of magnitude, compared with the surrounding plasma. None of the SADs indicate DEM solutions above 20 MK, which implies that SADs are indeed density depletion rather than very hot plasma. This depression in DEMs rapidly recovers as SADs pass through, generally in a few minutes. In addition, we found that SADs in one event appear spatio-temporally associated with the formation of postflare loops. These results are examined against models and numerical simulations.

BOREAS HYP-8 DEM Data Over The NSA-MSA and SSA-MSA in The AEAC Projection

NASA Technical Reports Server (NTRS)

Knapp, David E.; Hall, Forrest G. (Editor); Wang, Xue-Wen; Band, L. E.; Smith, David E. (Technical Monitor)

2000-01-01

These data were derived from the original Digital Elevation Models (DEMs) produced by the Boreal Ecosystem-Atmosphere Study (BOREAS) Hydrology (HYD)-8 team. The original DEMs were in the Universal Transverse Mercator (UTM) projection, while this product is projected in the Albers Equal-Area Conic (AEAC) projection. The pixel size of the data is 100 meters, which is appropriate for the 1:50,000-scale contours from which the DEMs were made. The original data were compiled from information available in the 1970s and 1980s. This data set covers the two Modeling Sub-Areas (MSAs) that are contained within the Southern Study Area (SSA) and the Northern Study Area (NSA). The data are stored in binary, image format files. The DEM data over the NSA-MSA and SSA-MSA in the AEAC projection are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The data files are available on a CD-ROM (see document number 20010000884).

Digital elevation model and orthophotographs of Greenland based on aerial photographs from 1978-1987.

PubMed

Korsgaard, Niels J; Nuth, Christopher; Khan, Shfaqat A; Kjeldsen, Kristian K; Bjørk, Anders A; Schomacker, Anders; Kjær, Kurt H

2016-05-10

Digital Elevation Models (DEMs) play a prominent role in glaciological studies for the mass balance of glaciers and ice sheets. By providing a time snapshot of glacier geometry, DEMs are crucial for most glacier evolution modelling studies, but are also important for cryospheric modelling in general. We present a historical medium-resolution DEM and orthophotographs that consistently cover the entire surroundings and margins of the Greenland Ice Sheet 1978-1987. About 3,500 aerial photographs of Greenland are combined with field surveyed geodetic ground control to produce a 25 m gridded DEM and a 2 m black-and-white digital orthophotograph. Supporting data consist of a reliability mask and a photo footprint coverage with recording dates. Through one internal and two external validation tests, this DEM shows an accuracy better than 10 m horizontally and 6 m vertically while the precision is better than 4 m. This dataset proved successful for topographical mapping and geodetic mass balance. Other uses include control and calibration of remotely sensed data such as imagery or InSAR velocity maps.

Radar and Lidar Radar DEM

NASA Technical Reports Server (NTRS)

Liskovich, Diana; Simard, Marc

2011-01-01

Using radar and lidar data, the aim is to improve 3D rendering of terrain, including digital elevation models (DEM) and estimates of vegetation height and biomass in a variety of forest types and terrains. The 3D mapping of vegetation structure and the analysis are useful to determine the role of forest in climate change (carbon cycle), in providing habitat and as a provider of socio-economic services. This in turn will lead to potential for development of more effective land-use management. The first part of the project was to characterize the Shuttle Radar Topography Mission DEM error with respect to ICESat/GLAS point estimates of elevation. We investigated potential trends with latitude, canopy height, signal to noise ratio (SNR), number of LiDAR waveform peaks, and maximum peak width. Scatter plots were produced for each variable and were fitted with 1st and 2nd degree polynomials. Higher order trends were visually inspected through filtering with a mean and median filter. We also assessed trends in the DEM error variance. Finally, a map showing how DEM error was geographically distributed globally was created.

Digital elevation model and orthophotographs of Greenland based on aerial photographs from 1978-1987

NASA Astrophysics Data System (ADS)

Korsgaard, Niels J.; Nuth, Christopher; Khan, Shfaqat A.; Kjeldsen, Kristian K.; Bjørk, Anders A.; Schomacker, Anders; Kjær, Kurt H.

2016-05-01

Digital Elevation Models (DEMs) play a prominent role in glaciological studies for the mass balance of glaciers and ice sheets. By providing a time snapshot of glacier geometry, DEMs are crucial for most glacier evolution modelling studies, but are also important for cryospheric modelling in general. We present a historical medium-resolution DEM and orthophotographs that consistently cover the entire surroundings and margins of the Greenland Ice Sheet 1978-1987. About 3,500 aerial photographs of Greenland are combined with field surveyed geodetic ground control to produce a 25 m gridded DEM and a 2 m black-and-white digital orthophotograph. Supporting data consist of a reliability mask and a photo footprint coverage with recording dates. Through one internal and two external validation tests, this DEM shows an accuracy better than 10 m horizontally and 6 m vertically while the precision is better than 4 m. This dataset proved successful for topographical mapping and geodetic mass balance. Other uses include control and calibration of remotely sensed data such as imagery or InSAR velocity maps.

Spitznävi: unterschiedliche klinische, dermatoskopische und histopathologische Merkmale in der Kindheit.

PubMed

Dika, Emi; Neri, Iria; Fanti, Pier Alessandro; Barisani, Alessia; Ravaioli, Giulia Maria; Patrizi, Annalisa

2017-01-01

Die Charakterisierung der klinischen Merkmale und des biologischen Potenzials von Spitznävi hat in den letzten Jahrzehnten breites Interesse gefunden. Das Ziel dieser Arbeit ist die Beschreibung der klinischen und dermatoskopischen Merkmale von Spitznävi sowie des klinischen Ergebnisses nach chirurgischer Exzision von Spitznävi in drei pädiatrischen Altersgruppen. Restrospektive Studie zur Analyse von klinischen Merkmalen, videodermatoskopischen Bildern, histopathologischen Diagnosen und Behandlungsergebnissen. Der Grad der Pigmentierung wurde sowohl klinisch als auch histopathologisch beurteilt. Bei 71 Patienten wurden 72 spitzoide Neoplasien entfernt. Videodermatologische Bilder lagen für 41 Patienten vor. Das Muster der Pigmentierung korrelierte signifikant mit dem Alter der Patienten: Hyperpigmentierte Läsionen waren bei Vorschulkindern selten, bei Patienten von 7 bis 12 Jahren und ab 13 Jahren dagegen häufiger. Eine histopathologische Diagnose von atypischen Spitznävi wurde selten durchgeführt. Keiner der Patienten, bei denen ursprünglich ein atypischer Spitznävus diagnostiziert worden war, entwickelte ein Lokalrezidiv oder Metastasen während der anschließenden Nachbeobachtung. Pigmentierte Spitznävi traten im Alter ab 13 Jahren häufiger auf. Die Studie bestätigt andere Berichte über die Altersverteilung von Pigmentierungsmustern und hebt die geringe Anzahl atypischer Spitznävi bei pädiatrischen Patienten hervor sowie das Ausbleiben von Rezidiven bei der langfristigen Nachbeobachtung. © 2017 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

Novel gene fusion of PRCC-MITF defines a new member of MiT family translocation renal cell carcinoma: clinicopathological analysis and detection of the gene fusion by RNA sequencing and FISH.

PubMed

Xia, Qiu-Yuan; Wang, Xiao-Tong; Ye, Sheng-Bing; Wang, Xuan; Li, Rui; Shi, Shan-Shan; Fang, Ru; Zhang, Ru-Song; Ma, Heng-Hui; Lu, Zhen-Feng; Shen, Qin; Bao, Wei; Zhou, Xiao-Jun; Rao, Qiu

2018-04-01

MITF, TFE3, TFEB and TFEC belong to the same microphthalmia-associated transcription factor family (MiT). Two transcription factors in this family have been identified in two unusual types of renal cell carcinoma (RCC): Xp11 translocation RCC harbouring TFE3 gene fusions and t(6;11) RCC harbouring a MALAT1-TFEB gene fusion. The 2016 World Health Organisation classification of renal neoplasia grouped these two neoplasms together under the category of MiT family translocation RCC. RCCs associated with the other two MiT family members, MITF and TFEC, have rarely been reported. Herein, we identify a case of MITF translocation RCC with the novel PRCC-MITF gene fusion by RNA sequencing. Histological examination of the present tumour showed typical features of MiT family translocation RCCs, overlapping with Xp11 translocation RCC and t(6;11) RCC. However, this tumour showed negative results in TFE3 and TFEB immunochemistry and split fluorescence in-situ hybridisation (FISH) assays. The other MiT family members, MITF and TFEC, were tested further immunochemically and also showed negative results. RNA sequencing and reverse transcription-polymerase chain reaction confirmed the presence of a PRCC-MITF gene fusion: a fusion of PRCC exon 5 to MITF exon 4. We then developed FISH assays covering MITF break-apart probes and PRCC-MITF fusion probes to detect the MITF gene rearrangement. This study both proves the recurring existence of MITF translocation RCC and expands the genotype spectrum of MiT family translocation RCCs. © 2017 John Wiley & Sons Ltd.

Umgang mit Antithrombotika bei Operationen an der Haut vor und nach Publikation der entsprechenden S3-Leitlinie.

PubMed

Gaskins, Matthew; Dittmann, Martin; Eisert, Lisa; Werner, Ricardo Niklas; Dressler, Corinna; Löser, Christoph; Nast, Alexander

2018-03-01

Laut einer Befragung im Jahre 2012 war der Umgang mit Antithrombotika bei dermatochirurgischen Eingriffen in Deutschland sehr heterogen. 2014 wurde erstmals eine evidenzbasierte Leitlinie zu diesem Thema veröffentlicht. Es wurde eine anonyme Befragung derselben Stichprobe zum Umgang mit Antithrombotika sowie zu Kenntnissen der Leitlinie durchgeführt. Die Ergebnisse wurden als relative Häufigkeiten berichtet und denen aus 2012 gegenübergestellt. 208 Antwortbögen wurden ausgewertet (Rücklaufquote: 36,6 %). Die große Mehrheit der Dermatologen erklärte, kleinere Eingriffe unter Fortführung der Therapie mit Phenprocoumon, niedrig dosierter Acetylsalicylsäure (≤ 100 mg) und Clopidogrel sowie mit direkten oralen Antikoagulanzien durchzuführen. Bei größeren Eingriffen war der Umgang hingegen weiterhin heterogen, insbesondere unter niedergelassenen Dermatologen. Der Anteil der Dermatologen, die Phenprocoumon, Acetylsalicylsäure und Clopidogrel leitlinienkonform verwendeten, hat sich insgesamt vergrößert. Führten 2012 beispielsweise 53,8 % der Klinikärzte bzw. 36,3 % der niedergelassenen Dermatologen eine große Exzision unter Fortführung der Therapie mit niedrig dosierter Acetylsalicylsäure durch, taten dies 2017 90,2 % bzw. 57,8 % (Phenprocoumon: 33,8 % bzw. 11,9 % auf 63,9 % bzw. 29,9 %; Clopidogrel: 36,9 % bzw. 23,2 % auf 63,9 % bzw. 30,6 %). Unter den Klinikärzten war ein hoher Anteil mit der Leitlinie vertraut und fand diese hilfreich. Eine Zunahme des leitlinienkonformen Verhaltens war bei allen Eingriffen zu verzeichnen. Bei größeren Eingriffen zeigte sich trotz deutlicher Verbesserung die Notwendigkeit verstärkter Anstrengungen zur Leitlinienumsetzung bzw. zur Identifizierung von Implementierungsbarrieren. © 2018 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

Alteration of the brain morphology and the response to the acute stress in the recombinant mouse lines with different predisposition to catalepsy.

PubMed

Kulikova, E A; Bazovkina, D V; Antonov, Y V; Akulov, A E; Kulikov, A V; Kondaurova, E M

2017-04-01

Catalepsy is an inability to correct an externally imposed awkward posture; it is associated with schizophrenia and depression in human. We created new recombinant B6.CBA-D13Mit76C and B6.CBA-D13Mit76B mouse lines on the C57Bl/6 genome, carrying the 102.73-110.56Mbp fragment of chromosome 13 derived from the catalepsy-prone CBA strain and catalepsy-resistant C57BL/6 strain, respectively. We compared the behavior and brain morphology (11.7T BioSpec 117/16 USR tomograph, Germany) in these lines. The effects of acute emotional stress on corticosterone's level in the blood and mRNA expression of Bdnf and Arc genes in the brain were investigated. The B6.CBA-D13Mit76B mice were non-cataleptic, while about 17% of B6.CBA-D13Mit76C mice demonstrated catalepsy-like immobility. No difference between these lines was revealed in the open field and social interaction tests. In the Morris water maze test, both lines effectively found the platform on the fourth day; however B6.CBA-D13Mit76B mice achieved significantly better results than cataleptic-prone animals. B6.CBA-D13Mit76C mice were characterized by decreased volume of the total brain and reduced sizes of striatum, cerebellum and pituitary gland. The both lines showed the similar basal and stress-induced levels of corticosterone, while the brain expression of Bdnf and Arc genes was more vulnerable to stress in the catalepsy-prone B6.CBA-D13Mit76C line. Copyright © 2016 Elsevier Ireland Ltd and Japan Neuroscience Society. All rights reserved.

Minimally invasive, nonendoscopic thyroidectomy: a cosmetic alternative to robotic-assisted thyroidectomy.

PubMed

Govednik, Cara M; Snyder, Samuel K; Quinn, Courtney E; Saxena, Saurabh; Jupiter, Daniel C

2014-10-01

The desire to improve cosmesis has driven the introduction of robotic-assisted and video-assisted thyroidectomy techniques. We report on minimally invasive thyroidectomy (MIT) through a 2-cm incision without the added need for video assistance and hypothesize similar clinical results to standard open thyroidectomy. Between May 2012 and December 2013, 62 nonendoscopic MIT were evaluated for demographics, clinical outcomes, and patient satisfaction on a 1-10 scale. The results were compared with a case-matched control group who underwent conventional open thyroidectomy by the same surgeon. The 124 study patients demonstrated no differences between groups for demographics or clinical outcomes except a smaller thyroid lobe in the MIT group (9.2 vs 11.7 g; P = .05). There were longer operative times in the MIT group (135.4 vs 119.6 minutes; P = .07) that were not equivalent by equivalence testing (P = .534). In MIT patients, transient recurrent laryngeal nerve injury occurred per nerves at risk (1.1% vs 3.4%; P = .62) with no permanent injuries in either group. There was no difference in symptomatic hypocalcemia (9.7% vs 11.3%; P = .77) and postoperative hematoma (0% vs 3.2%; P = .50). On follow-up, the measured MIT scar was significantly shorter (2.22 vs 3.98 cm; P < .00001), which resulted in significantly improved cosmetic satisfaction ratings (9.56 vs 8.66; P = .03). In selected patients, MIT through a 2-cm incision without endoscopic assistance is a safe alternative to standard open thyroidectomy in the hands of an experienced endocrine surgeon. The operating time is slightly increased, but clinical results are equivalent and patient satisfaction is significantly improved. Copyright © 2014 Elsevier Inc. All rights reserved.

Interactions of the Human LIP5 Regulatory Protein with Endosomal Sorting Complexes Required for Transport*♦

PubMed Central

Skalicky, Jack J.; Arii, Jun; Wenzel, Dawn M.; Stubblefield, William-May B.; Katsuyama, Angela; Uter, Nathan T.; Bajorek, Monika; Myszka, David G.; Sundquist, Wesley I.

2012-01-01

The endosomal sorting complex required for transport (ESCRT) pathway remodels membranes during multivesicular body biogenesis, the abscission stage of cytokinesis, and enveloped virus budding. The ESCRT-III and VPS4 ATPase complexes catalyze the membrane fission events associated with these processes, and the LIP5 protein helps regulate their interactions by binding directly to a subset of ESCRT-III proteins and to VPS4. We have investigated the biochemical and structural basis for different LIP5-ligand interactions and show that the first microtubule-interacting and trafficking (MIT) module of the tandem LIP5 MIT domain binds CHMP1B (and other ESCRT-III proteins) through canonical type 1 MIT-interacting motif (MIM1) interactions. In contrast, the second LIP5 MIT module binds with unusually high affinity to a novel MIM element within the ESCRT-III protein CHMP5. A solution structure of the relevant LIP5-CHMP5 complex reveals that CHMP5 helices 5 and 6 and adjacent linkers form an amphipathic “leucine collar” that wraps almost completely around the second LIP5 MIT module but makes only limited contacts with the first MIT module. LIP5 binds MIM1-containing ESCRT-III proteins and CHMP5 and VPS4 ligands independently in vitro, but these interactions are coupled within cells because formation of stable VPS4 complexes with both LIP5 and CHMP5 requires LIP5 to bind both a MIM1-containing ESCRT-III protein and CHMP5. Our studies thus reveal how the tandem MIT domain of LIP5 binds different types of ESCRT-III proteins, promoting assembly of active VPS4 enzymes on the polymeric ESCRT-III substrate. PMID:23105106

A three-dimensional FEM-DEM technique for predicting the evolution of fracture in geomaterials and concrete

NASA Astrophysics Data System (ADS)

Zárate, Francisco; Cornejo, Alejandro; Oñate, Eugenio

2018-07-01

This paper extends to three dimensions (3D), the computational technique developed by the authors in 2D for predicting the onset and evolution of fracture in a finite element mesh in a simple manner based on combining the finite element method and the discrete element method (DEM) approach (Zárate and Oñate in Comput Part Mech 2(3):301-314, 2015). Once a crack is detected at an element edge, discrete elements are generated at the adjacent element vertexes and a simple DEM mechanism is considered in order to follow the evolution of the crack. The combination of the DEM with simple four-noded linear tetrahedron elements correctly captures the onset of fracture and its evolution, as shown in several 3D examples of application.

The knockdown of OsVIT2 and MIT affects iron localization in rice seed.

PubMed

Bashir, Khurram; Takahashi, Ryuichi; Akhtar, Shamim; Ishimaru, Yasuhiro; Nakanishi, Hiromi; Nishizawa, Naoko K

2013-11-20

The mechanism of iron (Fe) uptake in plants has been extensively characterized, but little is known about how Fe transport to different subcellular compartments affects Fe localization in rice seed. Here, we discuss the characterization of a rice vacuolar Fe transporter 2 (OsVIT2) T-DNA insertion line (osvit2) and report that the knockdown of OsVIT2 and mitochondrial Fe transporter (MIT) expression affects seed Fe localization. osvit2 plants accumulated less Fe in their shoots when grown under normal or excess Fe conditions, while the accumulation of Fe was comparable to that in wild-type (WT) plants under Fe-deficient conditions. The accumulation of zinc, copper, and manganese also changed significantly in the shoots of osvit2 plants. The growth of osvit2 plants was also slow compared to that of WT plants. The concentration of Fe increased in osvit2 polished seeds. Previously, we reported that the expression of OsVIT2 was higher in MIT knockdown (mit-2) plants, and in this study, the accumulation of Fe in mit-2 seeds decreased significantly. These results suggest that vacuolar Fe trafficking is important for plant Fe homeostasis and distribution, especially in plants grown in the presence of excess Fe. Moreover, changes in the expression of OsVIT2 and MIT affect the concentration and localization of metals in brown rice as well as in polished rice seeds.

Composition dependence of charge and magnetic length scales in mixed valence manganite thin films

PubMed Central

Singh, Surendra; Freeland, J. W.; Fitzsimmons, M. R.; Jeen, H.; Biswas, A.

2016-01-01

Mixed-valence manganese oxides present striking properties like the colossal magnetoresistance, metal-insulator transition (MIT) that may result from coexistence of ferromagnetic, metallic and insulating phases. Percolation of such phase coexistence in the vicinity of MIT leads to first-order transition in these manganites. However the length scales over which the electronic and magnetic phases are separated across MIT which appears compelling for bulk systems has been elusive in (La1−yPry)1−xCaxMnO3 films. Here we show the in-plane length scale over which charge and magnetism are correlated in (La0.4Pr0.6)1−xCaxMnO3 films with x = 0.33 and 0.375, across the MIT temperature. We combine electrical transport (resistance) measurements, x-ray absorption spectroscopy (XAS), x-ray magnetic circular dichroism (XMCD), and specular/off-specular x-ray resonant magnetic scattering (XRMS) measurements as a function of temperature to elucidate relationships between electronic, magnetic and morphological structure of the thin films. Using off-specular XRMS we obtained the charge-charge and charge-magnetic correlation length of these LPCMO films across the MIT. We observed different charge-magnetic correlation length for two films which increases below the MIT. The different correlation length shown by two films may be responsible for different macroscopic (transport and magnetic) properties. PMID:27461993

Composition dependence of electronic, magnetic, transport and morphological properties of mixed valence manganite thin films

DOE PAGES

Singh, Surendra; Freeland, J. W.; Fitzsimmons, Michael R.; ...

2016-07-27

Mixed-valence manganese oxides present striking properties like the colossal magnetoresistance, metal-insulator transition (MIT) that may result from coexistence of ferromagnetic, metallic and insulating phases. Percolation of such phase coexistence in the vicinity of MIT leads to first-order transition in these manganites. However the length scales over which the electronic and magnetic phases are separated across MIT which appears compelling for bulk systems has been elusive in (La 1-yPr y) 1-xCaxMnO 3 films. Here we show the in-plane length scale over which charge and magnetism are correlated in (La 0.4Pr 0.6) 1-xCaxMnO3 films with x = 0.33 and 0.375, across themore » MIT temperature. We combine electrical transport (resistance) measurements, x-ray absorption spectroscopy (XAS), x-ray magnetic circular dichroism (XMCD), and specular/off-specular x-ray resonant magnetic scattering (XRMS) measurements as a function of temperature to elucidate relationships between electronic, magnetic and morphological structure of the thin films. Using off-specular XRMS we obtained the charge-charge and charge-magnetic correlation length of these LPCMO films across the MIT. We observed different charge-magnetic correlation length for two films which increases below the MIT. The different correlation length shown by two films may be responsible for different macroscopic (transport and magnetic) properties.« less

The effects of digital elevation model resolution on the calculation and predictions of topographic wetness indices.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Drover, Damion, Ryan

2011-12-01

One of the largest exports in the Southeast U.S. is forest products. Interest in biofuels using forest biomass has increased recently, leading to more research into better forest management BMPs. The USDA Forest Service, along with the Oak Ridge National Laboratory, University of Georgia and Oregon State University are researching the impacts of intensive forest management for biofuels on water quality and quantity at the Savannah River Site in South Carolina. Surface runoff of saturated areas, transporting excess nutrients and contaminants, is a potential water quality issue under investigation. Detailed maps of variable source areas and soil characteristics would thereforemore » be helpful prior to treatment. The availability of remotely sensed and computed digital elevation models (DEMs) and spatial analysis tools make it easy to calculate terrain attributes. These terrain attributes can be used in models to predict saturated areas or other attributes in the landscape. With laser altimetry, an area can be flown to produce very high resolution data, and the resulting data can be resampled into any resolution of DEM desired. Additionally, there exist many maps that are in various resolutions of DEM, such as those acquired from the U.S. Geological Survey. Problems arise when using maps derived from different resolution DEMs. For example, saturated areas can be under or overestimated depending on the resolution used. The purpose of this study was to examine the effects of DEM resolution on the calculation of topographic wetness indices used to predict variable source areas of saturation, and to find the best resolutions to produce prediction maps of soil attributes like nitrogen, carbon, bulk density and soil texture for low-relief, humid-temperate forested hillslopes. Topographic wetness indices were calculated based on the derived terrain attributes, slope and specific catchment area, from five different DEM resolutions. The DEMs were resampled from LiDAR, which is a laser altimetry remote sensing method, obtained from the USDA Forest Service at Savannah River Site. The specific DEM resolutions were chosen because they are common grid cell sizes (10m, 30m, and 50m) used in mapping for management applications and in research. The finer resolutions (2m and 5m) were chosen for the purpose of determining how finer resolutions performed compared with coarser resolutions at predicting wetness and related soil attributes. The wetness indices were compared across DEMs and with each other in terms of quantile and distribution differences, then in terms of how well they each correlated with measured soil attributes. Spatial and non-spatial analyses were performed, and predictions using regression and geostatistics were examined for efficacy relative to each DEM resolution. Trends in the raw data and analysis results were also revealed.« less

The Development and Validation of the Mood-based Indoor Tanning Scale.

PubMed

Carcioppolo, Nick; Chen, Yixin; John, Kevin K; Gonzalez, Andrea Martinez; King, Andy J; Morgan, Susan E; Hu, Shasa

2017-01-01

Research indicates that mood-based motivations may be an important predictor of indoor tanning bed use and may be related to indoor tanning dependence. Problematically, little research has been conducted to develop a psychometric measure of mood-based tanning motivations. The current study seeks to develop and validate the moodbased indoor tanning scale (MITS). Two studies were conducted to identify and verify the MITS factor structure as well as assess construct validity. Study 1 was conducted at 5 geographically diverse universities in the United States. Study 2 was conducted by using a national online sample in the United States. Results from study 1 specified the factor structure of the MITS. Results from study 2 suggest that a one-point increase in the MITS measure corresponds with using indoor tanning beds 11 more times in the past year. These findings demonstrate that moodbased tanning motivations are a strong predictor of indoor tanning intentions and behavior. Further, they suggest that health behavior researchers and healthcare practitioners can use the MITS to assess the extent to which mood-based motivations impact indoor tanning bed use.

Nonlinear Viscoelastic Breakup in a High-Velocity Airstream.

DTIC Science & Technology

1981-03-01

viscoelasticity PMMA /Poly (ethyl/butylacrylate) Jet analysis Extensional viscosity 106 SdhACV a. -- N .MM~OMW I~*it l -,’ bi. ab Weiss and Worshern’s...Zero shear viscosity (viscosity-avg.) %/ poise Polymethyl- 6 x 106 2.1 100. methacrylate ( PMMA ) 1.5 16. 1.0 2.0 0.5 0.3 Copolymer 80% PMMA 20% Polyethyl...Measured 2.1% Poly(methylmethacrylate) /diethylmalonate ( PMMA /DEM) 210 1980 + 250 (400) 1.5% PMMA /DEM 110 1780 + 200 (250) 1.0% PMMA /DEM 60 1480 + 150

Magnetosphere - Ionosphere - Thermosphere (MIT) Coupling at Jupiter

NASA Astrophysics Data System (ADS)

Yates, J. N.; Ray, L. C.; Achilleos, N.

2017-12-01

Jupiter's upper atmospheric temperature is considerably higher than that predicted by Solar Extreme Ultraviolet (EUV) heating alone. Simulations incorporating magnetosphere-ionosphere coupling effects into general circulation models have, to date, struggled to reproduce the observed atmospheric temperatures under simplifying assumptions such as azimuthal symmetry and a spin-aligned dipole magnetic field. Here we present the development of a full three-dimensional thermosphere model coupled in both hemispheres to an axisymmetric magnetosphere model. This new coupled model is based on the two-dimensional MIT model presented in Yates et al., 2014. This coupled model is a critical step towards to the development of a fully coupled 3D MIT model. We discuss and compare the resulting thermospheric flows, energy balance and MI coupling currents to those presented in previous 2D MIT models.

Global terrain classification using Multiple-Error-Removed Improved-Terrain (MERIT) to address susceptibility of landslides and other geohazards

NASA Astrophysics Data System (ADS)

Iwahashi, J.; Yamazaki, D.; Matsuoka, M.; Thamarux, P.; Herrick, J.; Yong, A.; Mital, U.

2017-12-01

A seamless model of landform classifications with regional accuracy will be a powerful platform for geophysical studies that forecast geologic hazards. Spatial variability as a function of landform on a global scale was captured in the automated classifications of Iwahashi and Pike (2007) and additional developments are presented here that incorporate more accurate depictions using higher-resolution elevation data than the original 1-km scale Shuttle Radar Topography Mission digital elevation model (DEM). We create polygon-based terrain classifications globally by using the 280-m DEM interpolated from the Multi-Error-Removed Improved-Terrain DEM (MERIT; Yamazaki et al., 2017). The multi-scale pixel-image analysis method, known as Multi-resolution Segmentation (Baatz and Schäpe, 2000), is first used to classify the terrains based on geometric signatures (slope and local convexity) calculated from the 280-m DEM. Next, we apply the machine learning method of "k-means clustering" to prepare the polygon-based classification at the globe-scale using slope, local convexity and surface texture. We then group the divisions with similar properties by hierarchical clustering and other statistical analyses using geological and geomorphological data of the area where landslides and earthquakes are frequent (e.g. Japan and California). We find the 280-m DEM resolution is only partially sufficient for classifying plains. We nevertheless observe that the categories correspond to reported landslide and liquefaction features at the global scale, suggesting that our model is an appropriate platform to forecast ground failure. To predict seismic amplification, we estimate site conditions using the time-averaged shear-wave velocity in the upper 30-m (VS30) measurements compiled by Yong et al. (2016) and the terrain model developed by Yong (2016; Y16). We plan to test our method on finer resolution DEMs and report our findings to obtain a more globally consistent terrain model as there are known errors in DEM derivatives at higher-resolutions. We expect the improvement in DEM resolution (4 times greater detail) and the combination of regional and global coverage will yield a consistent dataset of polygons that have the potential to improve relations to the Y16 estimates significantly.

Time-averaged discharge rate of subaerial lava at Kīlauea Volcano, Hawai‘i, measured from TanDEM-X interferometry: Implications for magma supply and storage during 2011-2013

USGS Publications Warehouse

Poland, Michael P.

2014-01-01

Differencing digital elevation models (DEMs) derived from TerraSAR add-on for Digital Elevation Measurements (TanDEM-X) synthetic aperture radar imagery provides a measurement of elevation change over time. On the East Rift Zone (EZR) of Kīlauea Volcano, Hawai‘i, the effusion of lava causes changes in topography. When these elevation changes are summed over the area of an active lava flow, it is possible to quantify the volume of lava emplaced at the surface during the time spanned by the TanDEM-X data—a parameter that can be difficult to measure across the entirety of an ~100 km2 lava flow field using ground-based techniques or optical remote sensing data. Based on the differences between multiple TanDEM-X-derived DEMs collected days to weeks apart, the mean dense-rock equivalent time-averaged discharge rate of lava at Kīlauea between mid-2011 and mid-2013 was approximately 2 m3/s, which is about half the long-term average rate over the course of Kīlauea's 1983–present ERZ eruption. This result implies that there was an increase in the proportion of lava stored versus erupted, a decrease in the rate of magma supply to the volcano, or some combination of both during this time period. In addition to constraining the time-averaged discharge rate of lava and the rates of magma supply and storage, topographic change maps derived from space-based TanDEM-X data provide insights into the four-dimensional evolution of Kīlauea's ERZ lava flow field. TanDEM-X data are a valuable complement to other space-, air-, and ground-based observations of eruptive activity at Kīlauea and offer great promise at locations around the world for aiding with monitoring not just volcanic eruptions but any hazardous activity that results in surface change, including landslides, floods, earthquakes, and other natural and anthropogenic processes.

Scientific visualization of glacier changes for public communication: the example of Findelengletscher, Switzerland

NASA Astrophysics Data System (ADS)

Rastner, Philipp; Jörg, Philipp Claudio; Huss, Matthias; Zemp, Michael

2013-04-01

The melting of glaciers and ice caps has been recognized as one of the best natural indicators for global climate change. In Switzerland, the early onset of both glacier research and detailed mapping of the country resulted in a wealth of historical material documenting glacier changes over the past 160 years. Fife years ago, the Universities of Zurich and Fribourg, along with the Swiss energy utility Axpo, launched the Glacier Laserscanning Experiment Obervallis (GLAXPO). In this project three laserscanning flights were performed on Findelengletscher in order to create high resolution Digital Elevation Models (DEM). These DEM provide a precise mapping of the glacier surface topography and serve as reference surface for the co-registration of past DEMs computed from digitized historical maps. In addition to that distributed numerical glacier models were run with ensembles of climate change scenarios in order to calculate glacier changes over the 21st century. The present work makes use of this great data pool for a scientifically correct visualization of 3-dimensional changes of Findelengletscher from AD 1850 to 2100 for public communication. We therefore collected ten different historical maps with the earliest dating from 1862 (plane survey sheet of the Dufour map). The pre-processing included georeferencing and digitalization of contour lines for the creation of different historical DEMs. Afterwards all historical DEMs were co-registered to one of the latest high resolution laserscanning DEM (from 2005). In between years with available DEMs, surface changes were interpolated linearly to create a sequence for the computer animation. For future developments, modeled glacier elevation changes where added/subtracted from the latest DEM (from 2010). Finally, two animations, showing glacier changes from 1850-2010 and 2010-2100, were composed and rendered in the animation program Visual Nature Studio 3. In cooperation with professional booth and model builders, these animations were set up as a glacier exhibit including an interactive touchscreen, a large panoramic view of the Findelen Valley, and an additional interactive monitor providing related background information in French and German. Beginning of 2013, the glacier exhibit was launched as permanent part of the Axporama visitor center and ready for more than 10,000 public visitors a year.

Delineation of gravel-bed clusters via factorial kriging

NASA Astrophysics Data System (ADS)

Wu, Fu-Chun; Wang, Chi-Kuei; Huang, Guo-Hao

2018-05-01

Gravel-bed clusters are the most prevalent microforms that affect local flows and sediment transport. A growing consensus is that the practice of cluster delineation should be based primarily on bed topography rather than grain sizes. Here we present a novel approach for cluster delineation using patch-scale high-resolution digital elevation models (DEMs). We use a geostatistical interpolation method, i.e., factorial kriging, to decompose the short- and long-range (grain- and microform-scale) DEMs. The required parameters are determined directly from the scales of the nested variograms. The short-range DEM exhibits a flat bed topography, yet individual grains are sharply outlined, making the short-range DEM a useful aid for grain segmentation. The long-range DEM exhibits a smoother topography than the original full DEM, yet groupings of particles emerge as small-scale bedforms, making the contour percentile levels of the long-range DEM a useful tool for cluster identification. Individual clusters are delineated using the segmented grains and identified clusters via a range of contour percentile levels. Our results reveal that the density and total area of delineated clusters decrease with increasing contour percentile level, while the mean grain size of clusters and average size of anchor clast (i.e., the largest particle in a cluster) increase with the contour percentile level. These results support the interpretation that larger particles group as clusters and protrude higher above the bed than other smaller grains. A striking feature of the delineated clusters is that anchor clasts are invariably greater than the D90 of the grain sizes even though a threshold anchor size was not adopted herein. The average areal fractal dimensions (Hausdorff-Besicovich dimensions of the projected areas) of individual clusters, however, demonstrate that clusters delineated with different contour percentile levels exhibit similar planform morphologies. Comparisons with a compilation of existing field data show consistency with the cluster properties documented in a wide variety of settings. This study thus points toward a promising, alternative DEM-based approach to characterizing sediment structures in gravel-bed rivers.

Biotechnology Process Engineering Center at MIT Home

Science.gov Websites

BPEC Definition 77 Massachusetts Avenue, Building 16 Room 429, Cambridge, MA 02139 Telephone (617 Leadership Council Facilities | Umbrella Programs | Events | News | Links | MIT | National Science Foundation

David Goldwasser | NREL

Science.gov Websites

. Prior to joining NREL, David worked in architectural design, 3D modeling, and interactive media. He consulted for Google on 3D modeling tools and worked in Colorado on sustainable architecture projects

MIT ASTROMAG 1.7 meter disk magnet design report

NASA Technical Reports Server (NTRS)

Marston, P. G.; Hale, J. R.; Vieira, R.; Zhukovsky, A.; Titus, P. H.; Sullivan, J. D.; Dawson, A. M.

1990-01-01

MIT has proposed a magnet design for ASTROMAG, which has demonstrated substantial improvement in performance as compared with the present HEAO baseline design. Several advantages of the MIT disk design are listed along with design characteristics. Details of field contours and active field regions are shown along with comparisons with other designs. Three alternative design configurations for the ASTROMAG disk coils are summarized. The parameters of the conductors are listed and basic parameters for each of the complete systems are shown.

Wake Turbulence Mitigation for Departures (WTMD) Prototype System - Software Design Document

NASA Technical Reports Server (NTRS)

Sturdy, James L.

2008-01-01

This document describes the software design of a prototype Wake Turbulence Mitigation for Departures (WTMD) system that was evaluated in shadow mode operation at the Saint Louis (KSTL) and Houston (KIAH) airports. This document describes the software that provides the system framework, communications, user displays, and hosts the Wind Forecasting Algorithm (WFA) software developed by the M.I.T. Lincoln Laboratory (MIT-LL). The WFA algorithms and software are described in a separate document produced by MIT-LL.

Intelligence in the Now: Robust Intelligence in Complex Domains

DTIC Science & Technology

2015-09-26

We have applied our model and the resulting search strategy for a mobile manipulator modeled on a Willow Garage PR2 robot. As shown in Figure 12...with them – the robot tries to move a handle to various target locations and observes the reached location. Figure 13 shows Willow Garage PR2 robot...Massachusetts Institute of Technology, Cambridge, MA 02139 USA barragan@mit.edu, tlp@mit.edu, lpk@mit.edu Fig. 1. Willow Garage PR2 robot manipulating

The role of the University Licensing Office in transferring intellectual property to industry

NASA Technical Reports Server (NTRS)

Preston, John T.

1992-01-01

Universities in the US have a significant impact on business through the transfer of technology. This transfer of technology takes various forms, including faculty communications, faculty consulting activities, and the direct transfer of technology through the licensing of patents, copyrights, and other intellectual property to industry. The topics discussed include the following: background of the MIT Technology Licensing Office (TLO), goals of the MIT TLO, MIT's technology transfer philosophy, and important factors for success in new company formation.

Effect of Withania somnifera on forced swimming test induced immobility in mice and its interaction with various drugs.

PubMed

Shah, P C; Trivedi, N A; Bhatt, J D; Hemavathi, K G

2006-01-01

The objective of the present study was to evaluate the antidepressant action of Withania somnifera (WS) as well as its interaction with the conventional antidepressant drugs and to delineate the possible mechanism of its antidepressant action using forced swimming model in mice. Effect of different doses of WS, fluoxetine and imipramine were studied on forced swimming test induced mean immobility time (MIT). Moreover effect of WS 100 mg/kg, i.p. was observed at different time intervals. Effect produced by combination of sub therapeutic doses of WS with imipramine (2.5 mg/kg, i.p.) as well as fluoxetine (2.5 mg/kg, i.p.) were also observed. Effect of WS (100 mg/kg, i.p.) as well as combination of WS (37.5 mg/kg, i.p.) with either imipramine (2.5 mg/kg, i.p.) or fluoxetine (2.5 mg/kg, i.p.) were observed in mice pretreated with reserpine (2 mg/kg, i.p.) and clonidine (0.15 mg/kg, i.p.). Effects of prazosin (3 mg/kg, i.p.) or haloperidol (0.1 mg/kg, i.p.) pre-treatment were also observed on WS induced decrease in MIT. WS produced dose dependent decrease in MIT. Maximum effect in MIT was observed after 30 min of treatment with WS 100 mg/kg, i.p. Combination of WS (37.5 mg/kg, i.p.) with imipramine (2.5 mg/kg, i.p.) or fluoxetine (2.5 mg/kg, i.p.) also produced significant decrease in the MIT. Clonidine and reserpine induced increase in MIT, was significantly reversed by treatment with WS (100 mg/kg, i.p.) as well as combination of WS (37.5 mg/kg, i.p.) with either imipramine (2.5 mg/kg, i.p.) or fluoxetine (2.5 mg/kg, i.p.). Pre-treatment with prazosin but not haloperidol, significantly antagonized the WS (100 mg/kg, i.p.) induced decrease in MIT. It is concluded that, WS produced significant decrease in MIT in mice which could be mediated partly through a adrenoceptor as well as alteration in the level of central biogenic amines.

High Intensity Interval- vs Moderate Intensity- Training for Improving Cardiometabolic Health in Overweight or Obese Males: A Randomized Controlled Trial.

PubMed

Fisher, Gordon; Brown, Andrew W; Bohan Brown, Michelle M; Alcorn, Amy; Noles, Corey; Winwood, Leah; Resuehr, Holly; George, Brandon; Jeansonne, Madeline M; Allison, David B

2015-01-01

To compare the effects of six weeks of high intensity interval training (HIIT) vs continuous moderate intensity training (MIT) for improving body composition, insulin sensitivity (SI), blood pressure, blood lipids, and cardiovascular fitness in a cohort of sedentary overweight or obese young men. We hypothesized that HIIT would result in similar improvements in body composition, cardiovascular fitness, blood lipids, and SI as compared to the MIT group, despite requiring only one hour of activity per week compared to five hours per week for the MIT group. 28 sedentary overweight or obese men (age, 20 ± 1.5 years, body mass index 29.5 ± 3.3 kg/m2) participated in a six week exercise treatment. Participants were randomly assigned to HIIT or MIT and evaluated at baseline and post-training. DXA was used to assess body composition, graded treadmill exercise test to measure cardiovascular fitness, oral glucose tolerance to measure SI, nuclear magnetic resonance spectroscopy to assess lipoprotein particles, and automatic auscultation to measure blood pressure. A greater improvement in VO2peak was observed in MIT compared to HIIT (11.1% vs 2.83%, P = 0.0185) in the complete-case analysis. No differences were seen in the intention to treat analysis, and no other group differences were observed. Both exercise conditions were associated with temporal improvements in % body fat, total cholesterol, medium VLDL, medium HDL, triglycerides, SI, and VO2peak (P < 0.05). Participation in HIIT or MIT exercise training displayed: 1) improved SI, 2) reduced blood lipids, 3) decreased % body fat, and 4) improved cardiovascular fitness. While both exercise groups led to similar improvements for most cardiometabolic risk factors assessed, MIT led to a greater improvement in overall cardiovascular fitness. Overall, these observations suggest that a relatively short duration of either HIIT or MIT training may improve cardiometabolic risk factors in previously sedentary overweight or obese young men, with no clear advantage between these two specific regimes (Clinical Trial Registry number NCT01935323). ClinicalTrials.gov NCT01935323.

High Intensity Interval- vs Moderate Intensity- Training for Improving Cardiometabolic Health in Overweight or Obese Males: A Randomized Controlled Trial

PubMed Central

Fisher, Gordon; Brown, Andrew W.; Bohan Brown, Michelle M.; Alcorn, Amy; Noles, Corey; Winwood, Leah; Resuehr, Holly; George, Brandon; Jeansonne, Madeline M.; Allison, David B.

2015-01-01

Purpose To compare the effects of six weeks of high intensity interval training (HIIT) vs continuous moderate intensity training (MIT) for improving body composition, insulin sensitivity (SI), blood pressure, blood lipids, and cardiovascular fitness in a cohort of sedentary overweight or obese young men. We hypothesized that HIIT would result in similar improvements in body composition, cardiovascular fitness, blood lipids, and SI as compared to the MIT group, despite requiring only one hour of activity per week compared to five hours per week for the MIT group. Methods 28 sedentary overweight or obese men (age, 20 ± 1.5 years, body mass index 29.5 ± 3.3 kg/m2) participated in a six week exercise treatment. Participants were randomly assigned to HIIT or MIT and evaluated at baseline and post-training. DXA was used to assess body composition, graded treadmill exercise test to measure cardiovascular fitness, oral glucose tolerance to measure SI, nuclear magnetic resonance spectroscopy to assess lipoprotein particles, and automatic auscultation to measure blood pressure. Results A greater improvement in VO2peak was observed in MIT compared to HIIT (11.1% vs 2.83%, P = 0.0185) in the complete-case analysis. No differences were seen in the intention to treat analysis, and no other group differences were observed. Both exercise conditions were associated with temporal improvements in % body fat, total cholesterol, medium VLDL, medium HDL, triglycerides, SI, and VO2peak (P < 0.05). Conclusion Participation in HIIT or MIT exercise training displayed: 1) improved SI, 2) reduced blood lipids, 3) decreased % body fat, and 4) improved cardiovascular fitness. While both exercise groups led to similar improvements for most cardiometabolic risk factors assessed, MIT led to a greater improvement in overall cardiovascular fitness. Overall, these observations suggest that a relatively short duration of either HIIT or MIT training may improve cardiometabolic risk factors in previously sedentary overweight or obese young men, with no clear advantage between these two specific regimes (Clinical Trial Registry number NCT01935323). Trial Registration ClinicalTrials.gov NCT01935323 PMID:26489022

Novel application of DEM to modelling comminution processes

NASA Astrophysics Data System (ADS)

Delaney, Gary W.; Cleary, Paul W.; Sinnott, Matt D.; Morrison, Rob D.

2010-06-01

Comminution processes in which grains are broken down into smaller and smaller sizes represent a critical component in many industries including mineral processing, cement production, food processing and pharmaceuticals. We present a novel DEM implementation capable of realistically modelling such comminution processes. This extends on a previous implementation of DEM particle breakage that utilized spherical particles. Our new extension uses super-quadric particles, where daughter fragments with realistic size and shape distributions are packed inside a bounding parent super-quadric. We demonstrate the flexibility of our approach in different particle breakage scenarios and examine the effect of the chosen minimum resolved particle size. This incorporation of the effect of particle shape in the breakage process allows for more realistic DEM simulations to be performed, that can provide additional fundamental insights into comminution processes and into the behaviour of individual pieces of industrial machinery.

GPS-Based Precision Baseline Reconstruction for the TanDEM-X SAR-Formation

NASA Technical Reports Server (NTRS)

Montenbruck, O.; vanBarneveld, P. W. L.; Yoon, Y.; Visser, P. N. A. M.

2007-01-01

The TanDEM-X formation employs two separate spacecraft to collect interferometric Synthetic Aperture Radar (SAR) measurements over baselines of about 1 km. These will allow the generation ofa global Digital Elevation Model (DEM) with an relative vertical accuracy of 2-4 m and a 10 m ground resolution. As part of the ground processing, the separation of the SAR antennas at the time of each data take must be reconstructed with a 1 mm accuracy using measurements from two geodetic grade GPS receivers. The paper discusses the TanDEM-X mission as well as the methods employed for determining the interferometric baseline with utmost precision. Measurements collected during the close fly-by of the two GRACE satellites serve as a reference case to illustrate the processing concept, expected accuracy and quality control strategies.

Digital Elevation Model, 0.25 m, Barrow Environmental Observatory, Alaska, 2013

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cathy Wilson; Garrett Altmann

This 0.25m horizontal resolution digital elevation model, DEM, was developed from Airborne Laser Altimetry flown by Aerometric Inc, now known as Quantum Spatial, Inc. on 12 July, 2013. One Mission was flown and the data jointly processed with LANL personnel to produce a 0.25m DEM covering a region approximately 2.8km wide and 12.4km long extending from the coast above North Salt Lagoon to south of Gas Well Road. This DEM encompasses a diverse range of hydrologic, geomorphic, geophysical and biological features typical of the Barrow Peninsula. Vertical accuracy at the 95% confidence interval was computed as 0.143m. The coordinate system,more » datum, and geoid for this DEM are UTM Zone 4N, NAD83 (2011), NAVD88 (GEOID09).« less

Identification of potential rockfall source areas at a regional scale using a DEM-based geomorphometric analysis

NASA Astrophysics Data System (ADS)

Loye, A.; Jaboyedoff, M.; Pedrazzini, A.

2009-10-01

The availability of high resolution Digital Elevation Models (DEM) at a regional scale enables the analysis of topography with high levels of detail. Hence, a DEM-based geomorphometric approach becomes more accurate for detecting potential rockfall sources. Potential rockfall source areas are identified according to the slope angle distribution deduced from high resolution DEM crossed with other information extracted from geological and topographic maps in GIS format. The slope angle distribution can be decomposed in several Gaussian distributions that can be considered as characteristic of morphological units: rock cliffs, steep slopes, footslopes and plains. A terrain is considered as potential rockfall sources when their slope angles lie over an angle threshold, which is defined where the Gaussian distribution of the morphological unit "Rock cliffs" become dominant over the one of "Steep slopes". In addition to this analysis, the cliff outcrops indicated by the topographic maps were added. They contain however "flat areas", so that only the slope angles values above the mode of the Gaussian distribution of the morphological unit "Steep slopes" were considered. An application of this method is presented over the entire Canton of Vaud (3200 km2), Switzerland. The results were compared with rockfall sources observed on the field and orthophotos analysis in order to validate the method. Finally, the influence of the cell size of the DEM is inspected by applying the methodology over six different DEM resolutions.

Large-baseline InSAR for precise topographic mapping: a framework for TanDEM-X large-baseline data

NASA Astrophysics Data System (ADS)

Pinheiro, Muriel; Reigber, Andreas; Moreira, Alberto

2017-09-01

The global Digital Elevation Model (DEM) resulting from the TanDEM-X mission provides information about the world topography with outstanding precision. In fact, performance analysis carried out with the already available data have shown that the global product is well within the requirements of 10 m absolute vertical accuracy and 2 m relative vertical accuracy for flat to moderate terrain. The mission's science phase took place from October 2014 to December 2015. During this phase, bistatic acquisitions with across-track separation between the two satellites up to 3.6 km at the equator were commanded. Since the relative vertical accuracy of InSAR derived elevation models is, in principle, inversely proportional to the system baseline, the TanDEM-X science phase opened the doors for the generation of elevation models with improved quality with respect to the standard product. However, the interferometric processing of the large-baseline data is troublesome due to the increased volume decorrelation and very high frequency of the phase variations. Hence, in order to fully profit from the increased baseline, sophisticated algorithms for the interferometric processing, and, in particular, for the phase unwrapping have to be considered. This paper proposes a novel dual-baseline region-growing framework for the phase unwrapping of the large-baseline interferograms. Results from two experiments with data from the TanDEM-X science phase are discussed, corroborating the expected increased level of detail of the large-baseline DEMs.

ArcticDEM Year 3; Improving Coverage, Repetition and Resolution

NASA Astrophysics Data System (ADS)

Morin, P. J.; Porter, C. C.; Cloutier, M.; Howat, I.; Noh, M. J.; Willis, M. J.; Candela, S. G.; Bauer, G.; Kramer, W.; Bates, B.; Williamson, C.

2017-12-01

Surface topography is among the most fundamental data sets for geosciences, essential for disciplines ranging from glaciology to geodynamics. The ArcticDEM project is using sub-meter, commercial imagery licensed by the National Geospatial-Intelligence Agency, petascale computing, and open source photogrammetry software to produce a time-tagged 2m posting elevation model and a 5m posting mosaic of the entire Arctic region. As ArcticDEM enters its third year, the region has gone from having some of the sparsest and poorest elevation data to some of the most precise and complete data of any region on the globe. To date, we have produced and released over 80,000,000 km2 as 57,000 - 2m posting, time-stamped DEMs. The Arctic, on average, is covered four times though there are hotspots with more than 100 DEMs. In addition, the version 1 release includes a 5m posting mosaic covering the entire 20,000,000 km2 region. All products are publically available through arctidem.org, ESRI web services, and a web viewer. The final year of the project will consist of a complete refiltering of clouds/water and re-mosaicing of all elevation data. Since inception of the project, post-processing techniques have improved significantly, resulting in fewer voids, better registration, sharper coastlines, and fewer inaccuracies due to clouds. All ArcticDEM data will be released in 2018. Data, documentation, web services and web viewer are available at arcticdem.org

A new seamless, high-resolution digital elevation model of the San Francisco Bay-Delta Estuary, California

USGS Publications Warehouse

Fregoso, Theresa A.; Wang, Rueen-Fang; Ateljevich, Eli; Jaffe, Bruce E.

2017-06-14

Climate change, sea-level rise, and human development have contributed to the changing geomorphology of the San Francisco Bay - Delta (Bay-Delta) Estuary system. The need to predict scenarios of change led to the development of a new seamless, high-resolution digital elevation model (DEM) of the Bay – Delta that can be used by modelers attempting to understand potential future changes to the estuary system. This report details the three phases of the creation of this DEM. The first phase took a bathymetric-only DEM created in 2005 by the U.S. Geological Survey (USGS), refined it with additional data, and identified areas that would benefit from new surveys. The second phase began a USGS collaboration with the California Department of Water Resources (DWR) that updated a 2012 DWR seamless bathymetric/topographic DEM of the Bay-Delta with input from the USGS and modifications to fit the specific needs of USGS modelers. The third phase took the work from phase 2 and expanded the coverage area in the north to include the Yolo Bypass up to the Fremont Weir, the Sacramento River up to Knights Landing, and the American River up to the Nimbus Dam, and added back in the elevations for interior islands. The constant evolution of the Bay-Delta will require continuous updates to the DEM of the Delta, and there still are areas with older data that would benefit from modern surveys. As a result, DWR plans to continue updating the DEM.

a High Precision dem Extraction Method Based on Insar Data

NASA Astrophysics Data System (ADS)

Wang, Xinshuang; Liu, Lingling; Shi, Xiaoliang; Huang, Xitao; Geng, Wei

2018-04-01

In the 13th Five-Year Plan for Geoinformatics Business, it is proposed that the new InSAR technology should be applied to surveying and mapping production, which will become the innovation driving force of geoinformatics industry. This paper will study closely around the new outline of surveying and mapping and then achieve the TerraSAR/TanDEM data of Bin County in Shaanxi Province in X band. The studying steps are as follows; Firstly, the baseline is estimated from the orbital data; Secondly, the interferometric pairs of SAR image are accurately registered; Thirdly, the interferogram is generated; Fourth, the interferometric correlation information is estimated and the flat-earth phase is removed. In order to solve the phase noise and the discontinuity phase existing in the interferometric image of phase, a GAMMA adaptive filtering method is adopted. Aiming at the "hole" problem of missing data in low coherent area, the interpolation method of low coherent area mask is used to assist the phase unwrapping. Then, the accuracy of the interferometric baseline is estimated from the ground control points. Finally, 1 : 50000 DEM is generated, and the existing DEM data is used to verify the accuracy through statistical analysis. The research results show that the improved InSAR data processing method in this paper can obtain the high-precision DEM of the study area, exactly the same with the topography of reference DEM. The R2 can reach to 0.9648, showing a strong positive correlation.

MIT gets good marks for fighting gender discrimination

NASA Astrophysics Data System (ADS)

Gwynne, Peter

2011-05-01

The Massachusetts Institute of Technology (MIT) has made "significant progress" in increasing the number of female faculty members, with their numbers in science and engineering almost doubling over the last decade.

ASTER-Derived 30-Meter-Resolution Digital Elevation Models of Afghanistan

USGS Publications Warehouse

Chirico, Peter G.; Warner, Michael B.

2007-01-01

INTRODUCTION The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) is an imaging instrument aboard the Terra satellite, launched on December 19, 1999, as part of the National Aeronautics and Space Administration's (NASA) Earth Observing System (EOS). The ASTER sensor consists of three subsystems: the visible and near infrared (VNIR), the shortwave infrared (SWIR), and the thermal infrared (TIR), each with a different spatial resolution (VNIR, 15 meters; SWIR, 30 meters, TIR 90 meters). The VNIR system has the capability to generate along-track stereo images that can be used to create digital elevation models (DEMs) at 30-meter resolution. Currently, the only available DEM dataset for Afghanistan is the 90-meter-resolution Shuttle Radar Topography Mission (SRTM) data. This dataset is appropriate for macroscale DEM analysis and mapping. However, ASTER provides a low cost opportunity to generate higher resolution data. For this publication, study areas were identified around populated areas and areas where higher resolution elevation data were desired to assist in natural resource assessments. The higher resolution fidelity of these DEMs can also be used for other terrain analysis including landform classification and geologic structure analysis. For this publication, ASTER scenes were processed and mosaicked to generate 36 DEMs which were created and extracted using PCI Geomatics' OrthoEngine 3D Stereo software. The ASTER images were geographically registered to Landsat data with at least 15 accurate and well distributed ground control points with a root mean square error (RMSE) of less that one pixel (15 meters). An elevation value was then assigned to each ground control point by extracting the elevation from the 90-meter SRTM data. The 36 derived DEMs demonstrate that the software correlated on nearly flat surfaces and smooth slopes accurately. Larger errors occur in cloudy and snow-covered areas, lakes, areas with steep slopes, and southeastern-facing slopes. In these areas, holes, large pits, and spikes were generated by the software during the correlation process and the automatic interpolation method. To eliminate these problems, overlapping DEMs were generated and filtered using a progressive morphologic filter. The quadrangles used to delineate the DEMs in the publication were derived from the Afghan Geodesy and Cartography Head Office's (AGCHO) 1:100,000-scale maps series quadrangles. Each DEM was clipped and assigned a name according to the associated AGCHO quadrangle name. The geospatial data included in this publication are intended to be used with any GIS software packages including, but not limited to, ESRI's ArcGIS and ERDAS IMAGINE.

Developmental Eye Movement (DEM) Test Norms for Mandarin Chinese-Speaking Chinese Children.

PubMed

Xie, Yachun; Shi, Chunmei; Tong, Meiling; Zhang, Min; Li, Tingting; Xu, Yaqin; Guo, Xirong; Hong, Qin; Chi, Xia

2016-01-01

The Developmental Eye Movement (DEM) test is commonly used as a clinical visual-verbal ocular motor assessment tool to screen and diagnose reading problems at the onset. No established norm exists for using the DEM test with Mandarin Chinese-speaking Chinese children. This study aims to establish the normative values of the DEM test for the Mandarin Chinese-speaking population in China; it also aims to compare the values with three other published norms for English-, Spanish-, and Cantonese-speaking Chinese children. A random stratified sampling method was used to recruit children from eight kindergartens and eight primary schools in the main urban and suburban areas of Nanjing. A total of 1,425 Mandarin Chinese-speaking children aged 5 to 12 years took the DEM test in Mandarin Chinese. A digital recorder was used to record the process. All of the subjects completed a symptomatology survey, and their DEM scores were determined by a trained tester. The scores were computed using the formula in the DEM manual, except that the "vertical scores" were adjusted by taking the vertical errors into consideration. The results were compared with the three other published norms. In our subjects, a general decrease with age was observed for the four eye movement indexes: vertical score, adjusted horizontal score, ratio, and total error. For both the vertical and adjusted horizontal scores, the Mandarin Chinese-speaking children completed the tests much more quickly than the norms for English- and Spanish-speaking children. However, the same group completed the test slightly more slowly than the norms for Cantonese-speaking children. The differences in the means were significant (P<0.001) in all age groups. For several ages, the scores obtained in this study were significantly different from the reported scores of Cantonese-speaking Chinese children (P<0.005). Compared with English-speaking children, only the vertical score of the 6-year-old group, the vertical-horizontal time ratio of the 8-year-old group and the errors of 9-year-old group had no significant difference (P>0.05); compared with Spanish-speaking children, the scores were statistically significant (P<0.001) for the total error scores of the age groups, except the 6-, 9-, 10-, and 11-year-old age groups (P>0.05). DEM norms may be affected by differences in language, cultural, and educational systems among various ethnicities. The norms of the DEM test are proposed for use with Mandarin Chinese-speaking children in Nanjing and will be proposed for children throughout China.

Developmental Eye Movement (DEM) Test Norms for Mandarin Chinese-Speaking Chinese Children

PubMed Central

Tong, Meiling; Zhang, Min; Li, Tingting; Xu, Yaqin; Guo, Xirong; Hong, Qin; Chi, Xia

2016-01-01

The Developmental Eye Movement (DEM) test is commonly used as a clinical visual-verbal ocular motor assessment tool to screen and diagnose reading problems at the onset. No established norm exists for using the DEM test with Mandarin Chinese-speaking Chinese children. This study aims to establish the normative values of the DEM test for the Mandarin Chinese-speaking population in China; it also aims to compare the values with three other published norms for English-, Spanish-, and Cantonese-speaking Chinese children. A random stratified sampling method was used to recruit children from eight kindergartens and eight primary schools in the main urban and suburban areas of Nanjing. A total of 1,425 Mandarin Chinese-speaking children aged 5 to 12 years took the DEM test in Mandarin Chinese. A digital recorder was used to record the process. All of the subjects completed a symptomatology survey, and their DEM scores were determined by a trained tester. The scores were computed using the formula in the DEM manual, except that the “vertical scores” were adjusted by taking the vertical errors into consideration. The results were compared with the three other published norms. In our subjects, a general decrease with age was observed for the four eye movement indexes: vertical score, adjusted horizontal score, ratio, and total error. For both the vertical and adjusted horizontal scores, the Mandarin Chinese-speaking children completed the tests much more quickly than the norms for English- and Spanish-speaking children. However, the same group completed the test slightly more slowly than the norms for Cantonese-speaking children. The differences in the means were significant (P<0.001) in all age groups. For several ages, the scores obtained in this study were significantly different from the reported scores of Cantonese-speaking Chinese children (P<0.005). Compared with English-speaking children, only the vertical score of the 6-year-old group, the vertical-horizontal time ratio of the 8-year-old group and the errors of 9-year-old group had no significant difference (P>0.05); compared with Spanish-speaking children, the scores were statistically significant (P<0.001) for the total error scores of the age groups, except the 6-, 9-, 10-, and 11-year-old age groups (P>0.05). DEM norms may be affected by differences in language, cultural, and educational systems among various ethnicities. The norms of the DEM test are proposed for use with Mandarin Chinese-speaking children in Nanjing and will be proposed for children throughout China. PMID:26881754

Motion of David Glacier in East Antarctica Observed by COSMO-SkyMed Differential SAR Interferometry

NASA Astrophysics Data System (ADS)

Han, H.; Lee, H.

2011-12-01

David glacier, located in Victoria Land, East Antarctica (75°20'S, 161°15'E), is an outlet glacier of 13 km width near the grounding line and 50 km long from the source to the grounding line. David glacier flows into Ross Sea forming Drygalski Ice Tongue, 100 km long and 23 km wide. In this study, we extracted a surface displacement map of David by applying differential SAR interferometry (DInSAR) to one-day tandem pairs obtained from COSMO-SkyMed satellites on April 28-29 (descending orbit) and May 5-6 (ascending orbit), 2011, respectively. Terra ASTER global digital elevation model (GDEM) is used to remove the topographic effect from the COSMO-SkyMed interferograms. David glacier showed maximum displacement of 35 cm during April 28-29 and 20 cm during May 5-6 in the direction of radar line of sight. The glacier can be divided into several blocks by the disparities of displacement between the different sliding zone. Surface displacement map contains errors originated from orbit data, atmospheric conditions, DEM error. GDEM is generated from the ASTER optical images acquired from 2000 to 2008. It has the vertical accuracy of about 20 m at 95% confidence with the 30 m of horizontal posting. The accuracy of GDEM reduces when cloud cover is included in the ASTER image. Particularly in the snow and ice area, GDEM is inaccurate due to whiteout effect during stereo matching. The inaccuracy of GDEM could be a reason of the observed glacier motion in the opposite direction of gravity. This problem can be solved by using TanDEM-X DEM. Bistatic acquisition of SAR images from the constellation of TerraSAR-X and TanDEM-X will generate a global DEM with the vertical accuracy better than 2 m and the horizontal posting of 12 m. We plan to perform DInSAR of COSMO-SkyMed one-day tandem pairs again when the high-accuracy TanDEM-X DEM is available in the near future. As a conclusion, we could analyze the displacement of David glacier in East Antarctica. The glacier showed very fast motion forming a block of streamlines with different flow velocity. For more accurate analysis, we will use TanDEM-X DEM to perform the DInSAR. The flow characteristics, ice mass balance, ice discharge rate of David glacier remains as an ongoing research.

Influence of different DEMs on the quality of the InSAR results: case study over Bankya and Mirovo areas

NASA Astrophysics Data System (ADS)

Nikolov, Hristo; Atanasova, Mila

2017-10-01

One of the key input parameters in obtaining end products from SAR data is the DEM used during their processing. This holds true especially when persistent scatterers InSAR method should be applied for example to study slow moving landslides or subsidence. Since nowadays most of the raw SAR data are of space borne origin for their correct processing to high precision products for relatively small areas with centimeter accuracy a DEM taking into account the particularities of the local topography is needed. Most of the DEMs used by the SAR processing software such as SRTM or ASTER are obtained by the same type of instrument and present some disagreements with height information acquired by leveling measurements or other geodetic means. This was the motivation for initiating this research - to prove the need of creating and using local DEM in SAR data processing at small scale and to check what the magnitude of the discrepancy between final InSAR products is in both cases where SRTM/ASTER and local DEM has been used. In addition investigated were two scenarios for SAR data processing - one with small baseline between image pairs and one having large baseline image pairs - in order to find out in which case local DEM has bigger impact. In course of this study two reference areas were considered - Bankya village near Sofia (SW region of Bulgaria) and Mirovo salt extraction site (NE region of Bulgaria). The reason those areas were selected lies in the high number of landslides registered and monitored by the competent authorities in the mentioned locations. The significance of the results obtained is witnessed by the fact that both sites we used have been included as reference sites for Bulgaria in the PanGeo EU funded project dealing with delivering information regarding ground instability geohazard as areas prone to subsidence of natural and manmade origin. In the said project largest part of the information has been extracted from Envisat SAR data, but now this information could be supplemented by adding such from Sentinel-1 derived by us. During this research two local DEMs have been extracted from the tiles including the areas of investigation, one using SRTM data and one from ASTER, and after this procedure both were compared to the DEM gathered by leveling measurements. Finally conclusions are drawn and a direction for future research steps is provided.

Initial Everglades Depth Estimation Network (EDEN) Digital Elevation Model Research and Development

USGS Publications Warehouse

Jones, John W.; Price, Susan D.

2007-01-01

Introduction The Everglades Depth Estimation Network (EDEN) offers a consistent and documented dataset that can be used to guide large-scale field operations, to integrate hydrologic and ecological responses, and to support biological and ecological assessments that measure ecosystem responses to the Comprehensive Everglades Restoration Plan (Telis, 2006). To produce historic and near-real time maps of water depths, the EDEN requires a system-wide digital elevation model (DEM) of the ground surface. Accurate Everglades wetland ground surface elevation data were non-existent before the U.S. Geological Survey (USGS) undertook the collection of highly accurate surface elevations at the regional scale. These form the foundation for EDEN DEM development. This development process is iterative as additional high accuracy elevation data (HAED) are collected, water surfacing algorithms improve, and additional ground-based ancillary data become available. Models are tested using withheld HAED and independently measured water depth data, and by using DEM data in EDEN adaptive management applications. Here the collection of HAED is briefly described before the approach to DEM development and the current EDEN DEM are detailed. Finally future research directions for continued model development, testing, and refinement are provided.

Dem Local Accuracy Patterns in Land-Use/Land-Cover Classification

NASA Astrophysics Data System (ADS)

Katerji, Wassim; Farjas Abadia, Mercedes; Morillo Balsera, Maria del Carmen

2016-01-01

Global and nation-wide DEM do not preserve the same height accuracy throughout the area of study. Instead of assuming a single RMSE value for the whole area, this study proposes a vario-model that divides the area into sub-regions depending on the land-use / landcover (LULC) classification, and assigns a local accuracy per each zone, as these areas share similar terrain formation and roughness, and tend to have similar DEM accuracies. A pilot study over Lebanon using the SRTM and ASTER DEMs, combined with a set of 1,105 randomly distributed ground control points (GCPs) showed that even though the inputDEMs have different spatial and temporal resolution, and were collected using difierent techniques, their accuracy varied similarly when changing over difierent LULC classes. Furthermore, validating the generated vario-models proved that they provide a closer representation of the accuracy to the validating GCPs than the conventional RMSE, by 94% and 86% for the SRTMand ASTER respectively. Geostatistical analysis of the input and output datasets showed that the results have a normal distribution, which support the generalization of the proven hypothesis, making this finding applicable to other input datasets anywhere around the world.

ASTER DEM performance

USGS Publications Warehouse

Fujisada, H.; Bailey, G.B.; Kelly, Glen G.; Hara, S.; Abrams, M.J.

2005-01-01

The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument onboard the National Aeronautics and Space Administration's Terra spacecraft has an along-track stereoscopic capability using its a near-infrared spectral band to acquire the stereo data. ASTER has two telescopes, one for nadir-viewing and another for backward-viewing, with a base-to-height ratio of 0.6. The spatial resolution is 15 m in the horizontal plane. Parameters such as the line-of-sight vectors and the pointing axis were adjusted during the initial operation period to generate Level-1 data products with a high-quality stereo system performance. The evaluation of the digital elevation model (DEM) data was carried out both by Japanese and U.S. science teams separately using different DEM generation software and reference databases. The vertical accuracy of the DEM data generated from the Level-1A data is 20 m with 95% confidence without ground control point (GCP) correction for individual scenes. Geolocation accuracy that is important for the DEM datasets is better than 50 m. This appears to be limited by the spacecraft position accuracy. In addition, a slight increase in accuracy is observed by using GCPs to generate the stereo data.

BlazeDEM3D-GPU A Large Scale DEM simulation code for GPUs

NASA Astrophysics Data System (ADS)

Govender, Nicolin; Wilke, Daniel; Pizette, Patrick; Khinast, Johannes

2017-06-01

Accurately predicting the dynamics of particulate materials is of importance to numerous scientific and industrial areas with applications ranging across particle scales from powder flow to ore crushing. Computational discrete element simulations is a viable option to aid in the understanding of particulate dynamics and design of devices such as mixers, silos and ball mills, as laboratory scale tests comes at a significant cost. However, the computational time required to simulate an industrial scale simulation which consists of tens of millions of particles can take months to complete on large CPU clusters, making the Discrete Element Method (DEM) unfeasible for industrial applications. Simulations are therefore typically restricted to tens of thousands of particles with highly detailed particle shapes or a few million of particles with often oversimplified particle shapes. However, a number of applications require accurate representation of the particle shape to capture the macroscopic behaviour of the particulate system. In this paper we give an overview of the recent extensions to the open source GPU based DEM code, BlazeDEM3D-GPU, that can simulate millions of polyhedra and tens of millions of spheres on a desktop computer with a single or multiple GPUs.

MIT-CSR XIS Project

NASA Technical Reports Server (NTRS)

1998-01-01

This report outlines the proposers' progress toward MIT's contribution to the X-Ray Imaging Spectrometer (XIS) experiment on the Japanese ASTRO-E mission. The report discusses electrical system design, mechanical system design, and ground support equipment.

Infrared Active Sm1-xndxnio3 Based Nano-Switchings For High Powers Laser Sources

NASA Astrophysics Data System (ADS)

Ngom, B. D.; Kana, J. B. Kana; Nemraoui, O.; Manyala, N.; Maaza, M.; Mdjoe, R.; Beye, A. C.

2008-09-01

This contribution was targeted to engineer novel thermochromic infrared nano-structured photonics. These smart optically tuneable materials are based on rare earth nickelates in the form of ReNiO3 where Re is bi-solution of rare earth metals of Samarium "Sm" and Neodynium "Nd." In addition to their Metal-Insulator tuneable transition temperature (MIT), these MIT oxide family exhibit a specific thermal stability and thus could be ideal to an ultimate optical limiting and other Non-Linear Optical properties for high power laser sources. This MIT thermochomic ReNiO3 system is novel in its nano-structured form and has not been investigated from nonlinear optical viewpoint. This contribution reports on the optimization of the synthesis of Sm1-xNdxNiO3 Nano-structures and investigation of their corresponding MIT electron dynamics.

The metal-insulator transition in a phase-separated manganite studied by in situ STS

NASA Astrophysics Data System (ADS)

Snijders, P. C.; Gao, M.; Guo, H.; Ward, T. Z.; Gao, H.-J.; Shen, J.; Gai, Z.

2012-02-01

Electronic phase separation (EPS) is a key feature at the heart of the wide variety of electronic and magnetic properties in complex oxides. One consequence of EPS is that electronic transport experiments in bulk materials or 2D films mostly probe the low resistivity electronic phases due to the percolative path of the current. We study oxygen deficient La5/8-xPrxCa3/8M nO3 (LPCMO) thin films using both in situ scanning tunneling spectroscopy (STS) and ex situ transport experiments. The oxygen deficiency is known to decrease the metal-insulator transition (MIT) temperature or even completely suppress the MIT in conventional transport experiments. We show that in situ STS is able to detect the MIT even in systems where conventional transport experiments do not show an MIT at zero magnetic field.

Hepatic arterial infusion of floxuridine and dexamethasone plus high-dose Mitomycin C for patients with unresectable hepatic metastases from colorectal carcinoma.

PubMed

Kemeny, Nancy; Eid, Ahmed; Stockman, Jennifer; Gonen, Mithat; Schwartz, Lawrence; Tetzlaff, Eric; Paty, Philip

2005-08-01

In vitro data suggest increased cytotoxicity with Mitomycin C (Mit-C) and Floxuridine (FUDR). Based on these data, we performed a phase II trial of hepatic arterial infusion (HAI) of FUDR and Dexamethasone (Dex) plus high-dose Mit-C for patients with unresectable hepatic metastases from colorectal carcinoma. High-dose Mit-C (15 mg/m2) was added via the pump sideport to HAI FUDR and Dex for 14 days of a 28-day cycle. Mit-C was given on days 1 and 29, and FUDR was given indefinitely until disease progression or discontinuation of therapy due to toxicity. Sixty-three patients with unresectable liver metastases were entered. The chemotherapy-naïve group (n = 26) and those previously treated (n = 37) had similar response and median survival: 73% and 70%, and 23 and 20 months, respectively. The major toxicities were liver bilomas (7.9%), elevation in bilirubin level >3 (22%), and biliary sclerosis (9.5%). Hematologic and gastrointestinal toxicity was less than 2%. The addition of high-dose Mit-C to HAI FUDR and Dex produced a high response rate even in previously treated patients. The median survival was 21 months even though half the patients were previously treated with chemotherapy. Biliary toxicity was higher than expected; therefore, alternatives to high dose Mit-C should be investigated when exploring additions to HAI therapy with FUDR and Dex. Copyright 2005 Wiley-Liss, Inc.

Metacognitive Interpersonal Therapy in group (MIT-G) for young adults with personality disorders: A pilot randomized controlled trial.

PubMed

Popolo, Raffaele; MacBeth, Angus; Canfora, Flaviano; Rebecchi, Daniela; Toselli, Cecilia; Salvatore, Giampaolo; Dimaggio, Giancarlo

2018-04-06

Young adults with personality disorders (PD) other than borderline are in urgent need of validated treatments to help them in managing important life transitions. Therapeutic interventions focused upon social and interpersonal difficulties may facilitate these individuals in maximizing opportunities for employment, forming stable romantic relationships, and belong to social groups. It is also important that they are offered evidence-based, first-line time-limited treatments in order to maximize effectiveness and reduce costs. We developed a 16-session programme of group-based Metacognitive Interpersonal Therapy (MIT-G) including psychoeducation on the main interpersonal motives, an experiential component enabling practice of awareness of mental states; and use of mentalistic knowledge for purposeful problem-solving. We report a feasibility, acceptability, and clinical significance randomized clinical trial. Participants meeting inclusion criteria were randomized to receive MIT-G (n = 10) or waiting list+TAU (n = 10). Dropout rate was low and session attendance high (92.19%). Participants in the MIT-G arm had symptomatic and functional improvements consistent with large effect sizes. In the MIT-G arm similarly large effects were noted for increased capacity to understand mental states and regulate social interactions using mentalistic knowledge. Results were sustained at follow-up. Our findings suggest potential for applying MIT-G in larger samples to further test its effectiveness in reducing PD-related symptoms and problematic social functioning. © 2018 The British Psychological Society.

Evolution of Structural and Electrical Properties of Oxygen-Deficient VO2 under Low Temperature Heating Process.

PubMed

Zhang, Jiasong; Zhao, Zhengjing; Li, Jingbo; Jin, Haibo; Rehman, Fida; Chen, Pengwan; Jiang, Yijie; Chen, Chunxu; Cao, Maosheng; Zhao, Yongjie

2017-08-16

Structural stability and functional performances of vanadium dioxide (VO 2 ) are strongly influenced by oxygen vacancies. However, the mechanism of metal-insulator transition (MIT) influenced by defects is still under debate. Here, we study the evolution of structure and electrical property of oxygen-deficient VO 2 by a low temperature annealing process (LTP) based on a truss-structured VO 2 nanonet. The oxygenation process of the oxygen-deficient VO 2 is greatly prolonged, which enables us to probe the gradual change of properties of the oxygen-deficient VO 2 . A continuous lattice reduction is observed during LTP. No recrystallization and structural collapse of the VO 2 nanonet can be found after LTP. The valence-band X-ray photoelectron spectroscopy (XPS) measurements indicate that the oxygen deficiency strongly affects the energy level of the valence band edge. Correspondingly, the resistance changes of the VO 2 films from 1 to 4.5 orders of magnitude are achieved by LTP. The effect of oxygen vacancy on the electric field driven MIT is investigated. The threshold value of voltage triggering the MIT decreases with increasing the oxygen vacancy concentration. This work demonstrates a novel and effective way to control the content of oxygen vacancies in VO 2 and the obvious impact of oxygen vacancy on MIT, facilitating further research on the role of oxygen vacancy in structure and MIT of VO 2 , which is important for the deep understanding of MIT and exploiting innovative functional application of VO 2 .

Activation of mitochondrial calpain and increased cardiac injury: beyond AIF release

PubMed Central

Thompson, Jeremy; Hu, Ying; Lesnefsky, Edward J.

2015-01-01

Calpain 1 (CPN1) is a ubiquitous cysteine protease that exists in both cytosol and cardiac mitochondria. Mitochondrial CPN1 (mit-CPN1) is located in the intermembrane space and matrix. Activation of mit-CPN1 within the intermembrane space increases cardiac injury by releasing apoptosis-inducing factor from mitochondria during ischemia-reperfusion (IR). We asked if activation of mit-CPN1 is involved in mitochondrial injury during IR. MDL-28170 (MDL) was used to inhibit CPN1 in buffer-perfused hearts following 25-min ischemia and 30-min reperfusion. MDL treatment decreased the release of lactate dehydrogenase into coronary effluent compared with untreated hearts, indicating that inhibition of CPN1 decreases cardiac injury. MDL also prevented the cleavage of spectrin (a substrate of CPN1) in cytosol during IR, supporting that MDL treatment decreased cytosolic calpain activation. In addition, MDL markedly improved calcium retention capacity compared with untreated heart, suggesting that MDL treatment decreases mitochondrial permeability transition pore opening. In addition, we found that IR led to decreased complex I activity, whereas inhibition of mit-CPN1 using MDL protected complex I. Pyruvate dehydrogenase content was decreased following IR. However, pyruvate dehydrogenase content was preserved in MDL-treated mitochondria. Taken together, MDL treatment decreased cardiac injury during IR by inhibiting both cytosolic and mit-CPN1. Activation of mit-CPN1 increases cardiac injury during IR by sensitizing mitochondrial permeability transition pore opening and impairing mitochondrial metabolism through damage of complex I. PMID:26637561

Designs of LiMIT as a Limiter in the EAST Tokamak

NASA Astrophysics Data System (ADS)

Szott, Matthew; Christenson, Michael; Kalathiparambil, Kishor; Ruzic, David

2016-10-01

Liquid metal plasma facing components (PFCs) provide a constantly refreshing, self-healing surface that can reduce erosion and thermal stress damage to prolong device lifetime, and additionally decrease edge recycling, reduce impurities, and enhance plasma performance. The Liquid Metal Infused Trench (LiMIT) system, developed at UIUC, has demonstrated thermoelectric magnetohydrodynamic (TEMHD) driven flow of liquid lithium through series of solid trenches. This TEMHD effect drives liquid lithium in fusion systems using the plasma heat flux and the toroidal magnetic field, and the surface tension of the liquid lithium maintains a fresh surface on top of the solid trenches. LiMIT has been successfully tested at UIUC as well as HT-7 and Magnum PSI at heat fluxes up to 3 MW/m2. The next step is demonstrating system viability in full-scale fusion-relevant conditions. In collaboration with a team in Hefei, design and testing has begun for a large scale LiMIT system that will act as a limiter in EAST. The designs improve upon previous versions of LiMIT tested at Illinois and incorporate lessons learned from earlier tests of liquid metal PFCs at EAST. Existing infrastructure is used to load and supply lithium to the system, and the LiMIT trenches will help maintain a smooth, fresh surface as well as aid in propelling the lithium out of direct plasma flux to improve heat transfer. Supported by DOE/ALPS DE-FG02-99ER54515.

Multiple Impulse Therapy in the Assessment of Paraspinal Muscle Tone in Patients with Low Back Pain.

PubMed

Haładaj, Robert; Topol, Mirosław

2016-11-30

Back pain is quite common in contemporary society, whose expectations of an effective analgesic therapy in conservative treatment lead to a necessity of searching for new diagnostic and therapeutic methods in physiotherapy. Out of the numerous physical therapy methods, Multiple Impulse Therapy (MIT) deserves special consideration. This paper aims to present and analyse the outcomes of MIT concerning paraspinal muscle tone and pain intensity in patients with low back pain. The study enrolled 117 patients (50 women and 67 men; average age of 45.3 yrs) with lumbar conditions confirmed by imaging studies. The participants received five MIT sessions within 14 days. Moreover, both before and after the therapy all the patients underwent bilateral assessment of the paraspinal muscle tone by surface electromyography (sEMG) with the NoraxonMyoTrace 400 system and an interactive head of the PulStarFRAS device. A VAS was used for evaluation of pain severity. The analysis of significance of differences between scores before and after treatment showed that all the parameters changed significantly (MIT: 11.11 Ibf before and 8.89 Ibf after the therapy; VAS: 6.04 before and 3.38 afterwards; sEMG: 9.29uV before and 7.51uV afterwards). 1. Multiple Impulse Therapy (MIT) is an effective and non-invasive method of back pain treatment. 2. MIT significantly reduces paraspinal muscle tone, as confirmed by sEMG results, and shows a strong analgesic effect.

Comparative analysis of Mouse Inoculation Test and Virus Isolation in Cell Culture for rabies diagnosis in animals of Parana, Brazil.

PubMed

Corona, Thaila Francini; Böger, Beatriz; Rocha, Tatiana Carneiro da; Svoboda, Walfrido Külh; Gomes, Eliane Carneiro

2018-01-01

Rabies is an acute zoonotic disease, caused by a rhabdovirus that can affect all mammals, and is commonly transmitted by the bite of a rabid animal. The definitive diagnosis is laboratorial, by the Fluorescent Antibody Test (FAT) as a quick test and Mouse Inoculation Test (MIT) as a confirmatory test (gold standard). Studies conducted over the past three decades indicate that MIT and Virus Isolation in Cell Culture (VICC) can provide the same effectiveness, the latter being considered superior in bioethics and animal welfare. The aim of this study was to compare VICC with MIT, in terms of accuracy, biosafety and occupational health, supply and equipment costs, bioethics and animal welfare, in a Brazilian public health lab. We utilized 400 samples of animal neurological tissue to compare the performance of VICC against MIT. The variables analyzed were accuracy, biosafety and occupational health, time spent in performing the tests, supply and equipment costs, bioethics and animal welfare evaluation. Both VICC and MIT had almost the same accuracy (99.8%), although VICC presented fewer risks regarding biosafety and mental health of the technicians, and reduced time between inoculation and obtaining the results (approximately 22 days less). In addition, VICC presented lower supply costs (86.5% less), equipment costs (32.6% less), and the advantage of not using animals. These results confirm that VICC can replace MIT, offering the same accuracy and better features regarding cost, results, biosafety and occupational health, and bioethics and animal welfare.

Supercomputing Drives Innovation - Continuum Magazine | NREL

Science.gov Websites

years, NREL scientists have used supercomputers to simulate 3D models of the primary enzymes and Scientist, discuss a 3D model of wind plant aerodynamics, showing low velocity wakes and impact on

Investigations of formation of quasi-static vortex-structures in granular bodies using DEM

NASA Astrophysics Data System (ADS)

Kozicki, Jan; Tejchman, Jacek

2017-06-01

The paper presents some two-dimensional simulation results of vortex-structures in cohesionless initially dense sand during quasi-static passive wall translation. The sand behaviour was simulated using the discrete element method (DEM). Sand grains were modelled by spheres with contact moments to approximately capture the irregular grain shape. In order to detect vortex-structures, the Helmholtz-Hodge decomposition of a flow displacement field from DEM calculations was used. This approach enabled us to distinguish both incompressibility and vorticity in the granular displacement field.

Influence of Terraced area DEM Resolution on RUSLE LS Factor

NASA Astrophysics Data System (ADS)

Zhang, Hongming; Baartman, Jantiene E. M.; Yang, Xiaomei; Gai, Lingtong; Geissen, Viollette

2017-04-01

Topography has a large impact on the erosion of soil by water. Slope steepness and slope length are combined (the LS factor) in the universal soil-loss equation (USLE) and its revised version (RUSLE) for predicting soil erosion. The LS factor is usually extracted from a digital elevation model (DEM). The grid size of the DEM will thus influence the LS factor and the subsequent calculation of soil loss. Terracing is considered as a support practice factor (P) in the USLE/RUSLE equations, which is multiplied with the other USLE/RUSLE factors. However, as terraces change the slope length and steepness, they also affect the LS factor. The effect of DEM grid size on the LS factor has not been investigated for a terraced area. We obtained a high-resolution DEM by unmanned aerial vehicles (UAVs) photogrammetry, from which the slope steepness, slope length, and LS factor were extracted. The changes in these parameters at various DEM resolutions were then analysed. The DEM produced detailed LS-factor maps, particularly for low LS factors. High (small valleys, gullies, and terrace ridges) and low (flats and terrace fields) spatial frequencies were both sensitive to changes in resolution, so the areas of higher and lower slope steepness both decreased with increasing grid size. Average slope steepness decreased and average slope length increased with grid size. Slope length, however, had a larger effect than slope steepness on the LS factor as the grid size varied. The LS factor increased when the grid size increased from 0.5 to 30-m and increased significantly at grid sizes >5-m. The LS factor was increasingly overestimated as grid size decreased. The LS factor decreased from grid sizes of 30 to 100-m, because the details of the terraced terrain were gradually lost, but the factor was still overestimated.

Analysis of ArcticDEM orthorectification for polar navigational traverses

NASA Astrophysics Data System (ADS)

Menio, E. C.; Deeb, E. J.; Weale, J.; Courville, Z.; Tracy, B.; Cloutier, M. D.; Cothren, J. D.; Liu, J.

2017-12-01

The availability and accessibility of high-resolution satellite imagery allows operational support teams to visually assess physical risks along traverse routes before and during the field season. In support of operations along the Greenland Inland Traverse (GrIT), DigitalGlobe's WorldView 0.5m resolution panchromatic imagery is analyzed to identify and digitize crevasse features along the route from Thule Air Force Base to Summit Station, Greenland. In the spring of 2016, field teams reported up to 150 meters of offset between the location of crevasse features on the ground and the location of the same feature on the imagery provided. Investigation into this issue identified the need to orthorectify imagery—use digital elevation models (DEMs) to correct viewing geometry distortions—to improve navigational accuracy in the field. It was previously thought that orthorectification was not necessary for applications in relatively flat terrain such as ice sheets. However, the surface elevations on the margins of the Greenland Ice Sheet vary enough to cause distortions in imagery, if taken obliquely. As is standard for requests, the Polar Geospatial Center (PGC) provides orthorectified imagery using the MEaSUREs Greenland Ice Mapping Project (GIMP) 30m digital elevation model. Current, higher-resolution elevation datasets, such as the ArcticDEM (2-5m resolution) and WorldView stereopair DEMs (2-3m resolution), are available for use in orthorectification. This study examines three heavily crevassed areas along the GrIT traverse, as identified in 2015 and 2016 imagery. We extracted elevation profiles along the GrIT route from each of the three DEMs: GIMP, ArcticDEM, and WorldView stereopair mosaic. Results show the courser GIMP data deviating significantly from the ArcticDEM and WorldView data, at points by up to 80m, which is seen as offset of features in plan view. In-situ Ground Penetrating Radar (GPR) surveys of crevasse crossings allow for evaluation of geopositional accuracy of each resulting orthorectified photo and a quantitative analysis of plan view offset.

Digital stereo photogrammetry for grain-scale monitoring of fluvial surfaces: Error evaluation and workflow optimisation

NASA Astrophysics Data System (ADS)

Bertin, Stephane; Friedrich, Heide; Delmas, Patrice; Chan, Edwin; Gimel'farb, Georgy

2015-03-01

Grain-scale monitoring of fluvial morphology is important for the evaluation of river system dynamics. Significant progress in remote sensing and computer performance allows rapid high-resolution data acquisition, however, applications in fluvial environments remain challenging. Even in a controlled environment, such as a laboratory, the extensive acquisition workflow is prone to the propagation of errors in digital elevation models (DEMs). This is valid for both of the common surface recording techniques: digital stereo photogrammetry and terrestrial laser scanning (TLS). The optimisation of the acquisition process, an effective way to reduce the occurrence of errors, is generally limited by the use of commercial software. Therefore, the removal of evident blunders during post processing is regarded as standard practice, although this may introduce new errors. This paper presents a detailed evaluation of a digital stereo-photogrammetric workflow developed for fluvial hydraulic applications. The introduced workflow is user-friendly and can be adapted to various close-range measurements: imagery is acquired with two Nikon D5100 cameras and processed using non-proprietary "on-the-job" calibration and dense scanline-based stereo matching algorithms. Novel ground truth evaluation studies were designed to identify the DEM errors, which resulted from a combination of calibration errors, inaccurate image rectifications and stereo-matching errors. To ensure optimum DEM quality, we show that systematic DEM errors must be minimised by ensuring a good distribution of control points throughout the image format during calibration. DEM quality is then largely dependent on the imagery utilised. We evaluated the open access multi-scale Retinex algorithm to facilitate the stereo matching, and quantified its influence on DEM quality. Occlusions, inherent to any roughness element, are still a major limiting factor to DEM accuracy. We show that a careful selection of the camera-to-object and baseline distance reduces errors in occluded areas and that realistic ground truths help to quantify those errors.

Social stress contagion in rats: Behavioural, autonomic and neuroendocrine correlates.

PubMed

Carnevali, Luca; Montano, Nicola; Statello, Rosario; Coudé, Gino; Vacondio, Federica; Rivara, Silvia; Ferrari, Pier Francesco; Sgoifo, Andrea

2017-08-01

The negative emotional consequences associated with life stress exposure in an individual can affect the emotional state of social partners. In this study, we describe an experimental rat model of social stress contagion and its effects on social behaviour and cardiac autonomic and neuroendocrine functions. Adult male Wistar rats were pair-housed and one animal (designated as "demonstrator" (DEM)) was submitted to either social defeat stress (STR) by an aggressive male Wild-type rat in a separate room or just exposed to an unfamiliar empty cage (control condition, CTR), once a day for 4 consecutive days. We evaluated the influence of cohabitation with a STR DEM on behavioural, cardiac autonomic and neuroendocrine outcomes in the cagemate (defined "observer" (OBS)). After repeated social stress, STR DEM rats showed clear signs of social avoidance when tested in a new social context compared to CTR DEM rats. Interestingly, also their cagemate STR OBSs showed higher levels of social avoidance compared to CTR OBSs. Moreover, STR OBS rats exhibited a higher heart rate and a larger shift of cardiac autonomic balance toward sympathetic prevalence (as indexed by heart rate variability analysis) immediately after the first reunification with their STR DEMs, compared to the control condition. This heightened cardiac autonomic responsiveness habituated over time. Finally, STR OBSs showed elevated plasma corticosterone levels at the end of the experimental protocol compared to CTR OBSs. These findings demonstrate that cohabitation with a DEM rat, which has experienced repeated social defeat stress, substantially disrupts social behaviour and induces short-lasting cardiac autonomic activation and hypothalamic-pituitary-adrenal axis hyperactivity in the OBS rat, thus suggesting emotional state-matching between the OBS and the DEM rats. We conclude that this rodent model may be further exploited for investigating the neurobiological bases of negative affective sharing between social partners under chronic social stress conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Quality assessment of Digital Elevation Model (DEM) in view of the Altiplano hydrological modeling

NASA Astrophysics Data System (ADS)

Satgé, F.; Arsen, A.; Bonnet, M.; Timouk, F.; Calmant, S.; Pilco, R.; Molina, J.; Lavado, W.; Crétaux, J.; HASM

2013-05-01

Topography is crucial data input for hydrological modeling but in many regions of the world, the only way to characterize topography is the use of satellite-based Digital Elevation Models (DEM). In some regions, the quality of these DEMs remains poor and induces modeling errors that may or not be compensated by model parameters tuning. In such regions, the evaluation of these data uncertainties is an important step in the modeling procedure. In this study, which focuses on the Altiplano region, we present the evaluation of the two freely available DEM. The shuttle radar topographic mission (SRTM), a product of the National Aeronautics and Space Administration (NASA) and the Advanced Space Born Thermal Emission and Reflection Global Digital Elevation Map (ASTER GDEM), data provided by the Ministry of Economy, Trade and Industry of Japan (MESI) in collaboration with the NASA, are widely used. While the first represents a resolution of 3 arc seconds (90m) the latter is 1 arc second (30m). In order to select the most reliable DEM, we compared the DEM elevation with high qualities control points elevation. Because of its large spatial coverture (track spaced of 30 km with a measure of each 172 m) and its high vertical accuracy which is less than 15 cm in good weather conditions, the Geoscience Laser Altimeter System (GLAS) on board on the Ice, Cloud and Land elevation Satellite of NASA (ICESat) represent the better solution to establish a high quality elevation database. After a quality check, more than 150 000 ICESat/GLAS measurements are suitable in terms of accuracy for the Altiplano watershed. This data base has been used to evaluate the vertical accuracy for each DEM. Regarding to the full spatial coverture; the comparison has been done for both, all kind of land coverture, range altitude and mean slope.

Influence of the external DEM on PS-InSAR processing and results on Northern Appennine slopes

NASA Astrophysics Data System (ADS)

Bayer, B.; Schmidt, D. A.; Simoni, A.

2014-12-01

We present an InSAR analysis of slow moving landslide in the Northern Appennines, Italy, and assess the dependencies on the choice of DEM. In recent years, advanced processing techniques for synthetic aperture radar interferometry (InSAR) have been applied to measure slope movements. The persistent scatterers (PS-InSAR) approach is probably the most widely used and some codes are now available in the public domain. The Stanford method of Persistent Scatterers (StamPS) has been successfully used to analyze landslide areas. One problematic step in the processing chain is the choice of an external DEM that is used to model and remove the topographic phase in a series of interferograms in order to obtain the phase contribution caused by surface deformation. The choice is not trivial, because the PS InSAR results differ significantly in terms of PS identification, positioning, and the resulting deformation signal. We use four different DEMs to process a set of 18 ASAR (Envisat) scenes over a mountain area (~350 km2) of the Northern Appennines of Italy, using StamPS. Slow-moving landslides control the evolution of the landscape and cover approximately 30% of the territory. Our focus in this presentation is to evaluate the influence of DEM resolution and accuracy by comparing PS-InSAR results. On an areal basis, we perform a statistical analysis of displacement time-series to make the comparison. We also consider two case studies to illustrate the differences in terms of PS identification, number and estimated displacements. It is clearly shown that DEM accuracy positively influences the number of PS, while line-of-sight rates differ from case to case and can result in deformation signals that are difficult to interpret. We also take advantage of statistical tools to analyze the obtained time-series datasets for the whole study area. Results indicate differences in the style and amount of displacement that can be related to the accuracy of the employed DEM.

Digital Elevation Models of Greenland based on combined radar and laser altimetry as well as high-resolution stereoscopic imagery

NASA Astrophysics Data System (ADS)

Levinsen, J. F.; Smith, B. E.; Sandberg Sorensen, L.; Khvorostovsky, K.; Simonsen, S. B.; Forsberg, R.

2015-12-01

A number of Digital Elevation Models (DEMs) of Greenland exist, each of which are applicable for different purposes. This study presents two such DEMs: One developed by merging contemporary radar and laser altimeter data, and one derived from high-resolution stereoscopic imagery. All products are made freely available. The former DEM covers the entire Greenland. It is specific to the year 2010, providing it with an advantage over previous models suffering from either a reduced spatial/ temporal data coverage or errors from surface elevation changes (SEC) occurring during data acquisition. Radar data are acquired with Envisat and CryoSat-2, and laser data with the Ice, Cloud, and land Elevation Satellite, the Land, Vegetation, and Ice Sensor, and the Airborne Topographic Mapper. Correcting radar data for errors from slope effects and surface penetration of the echoes, and merging these with laser data, yields a DEM capable of resolving both surface depressions as well as topographic features at higher altitudes. The spatial resolution is 2 x 2 km, making the DEM ideal for application in surface mass balance studies, SEC detection from radar altimetry, or for correcting such data for slope-induced errors. The other DEM is developed in a pilot study building the expertise to map all ice-free parts of Greenland. The work combines WorldView-2 and -3 as well as GeoEye1 imagery from 2014 and 2015 over the Disko, Narsaq, Tassilaq, and Zackenberg regions. The novelty of the work is the determination of the product specifications after elaborate discussions with interested parties from government institutions, the tourist industry, etc. Thus, a 10 m DEM, 1.5 m orthophotos, and vector maps are produced. This opens to the possibility of using orthophotos with up-to-date contour lines or for deriving updated coastlines to aid, e.g., emergency management. This allows for a product development directly in line with the needs of parties with specific interests in Greenland.

A framework for global terrain classification using 250-m DEMs to predict geohazards

NASA Astrophysics Data System (ADS)

Iwahashi, J.; Matsuoka, M.; Yong, A.

2016-12-01

Geomorphology is key for identifying factors that control geohazards induced by landslides, liquefaction, and ground shaking. To systematically identify landforms that affect these hazards, Iwahashi and Pike (2007; IP07) introduced an automated terrain classification scheme using 1-km-scale Shuttle Radar Topography Mission (SRTM) digital elevation models (DEMs). The IP07 classes describe 16 categories of terrain types and were used as a proxy for predicting ground motion amplification (Yong et al., 2012; Seyhan et al., 2014; Stewart et al., 2014; Yong, 2016). These classes, however, were not sufficiently resolved because coarse-scaled SRTM DEMs were the basis for the categories (Yong, 2016). Thus, we develop a new framework consisting of more detailed polygonal global terrain classes to improve estimations of soil-type and material stiffness. We first prepare high resolution 250-m DEMs derived from the 2010 Global Multi-resolution Terrain Elevation Data (GMTED2010). As in IP07, we calculate three geometric signatures (slope, local convexity and surface texture) from the DEMs. We create additional polygons by using the same signatures and multi-resolution segmentation techniques on the GMTED2010. We consider two types of surface texture thresholds in different window sizes (3x3 and 13x13 pixels), in addition to slope and local convexity, to classify pixels within the DEM. Finally, we apply the k-means clustering and thresholding methods to the 250-m DEM and produce more detailed polygonal terrain classes. We compare the new terrain classification maps of Japan and California with geologic, aerial photography, and landslide distribution maps, and visually find good correspondence of key features. To predict ground motion amplification, we apply the Yong (2016) method for estimating VS30. The systematic classification of geomorphology has the potential to provide a better understanding of the susceptibility to geohazards, which is especially vital in populated areas.

BOREAS HYD-8 DEM Data Over the NSA-MSA and SSA-MSA in the UTM Projection

NASA Technical Reports Server (NTRS)

Wang, Xue-Wen; Hall, Forrest G. (Editor); Knapp, David E. (Editor); Band, L. E.; Smith, David E. (Technical Monitor)

2000-01-01

The BOREAS HYD-8 team focused on describing the scaling behavior of water and carbon flux processes at local and regional scales. These DEMs were produced from digitized contours at a cell resolution of 100 meters. Vector contours of the area were used as input to a software package that interpolates between contours to create a DEM representing the terrain surface. The vector contours had a contour interval of 25 feet. The data cover the BOREAS MSAs of the SSA and NSA and are given in a UTM map projection. Most of the elevation data from which the DEM was produced were collected in the 1970s or 1980s. The data are stored in binary, image format files. The data files are available on a CD-ROM (see document number 20010000884) or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

An investigation of Digital Elevation Model (DEM) structure influence on flood modelling

NASA Astrophysics Data System (ADS)

Sahid; Nurrohman, A. W.; Hadi, M. P.

2018-04-01

Flood is one of the natural calamities that cause huge losses and damages. Flood hazard zonation has been widely produced to face the impact of the disaster. DEM as the primary data to construct the earth surface has been developed from rough to fine resolution. Aster GDEM v.2 within 1arc spatial resolution has an ability to derived DEM and TIN data as bases river geometrics data. Maximum daily peak discharges used to calculate flood peak discharge. Furthermore, steady flow analysis has been used to produce flood inundation model based on four scenarios with return periods 5yr, 10yr, 50yr, and 100yr. The model results have been validated using UAV flood map in 2016 by means of pixel by pixel operation and the result shows that the vertical variance between grid DEM and TIN data about 0.3 m.

Topographic Features of Malyy Naryn River Watershed Based on Different Data

NASA Astrophysics Data System (ADS)

Li, M.; Chen, L.; Cui, Y.; Zhang, M.

2018-04-01

This paper researched the influence on the topographical characteristics of watersheds by setting different catchment area thresholds based on different data sets, namely ZY3 DSM, SRTM DEM and ASTER GDEM. Slope, hypsometric integral, river network density and river network discrepancy are analyzed and compared. The results are as follows: a) Three data sets all can express the same rough terrain characteristics and the same degree of watershed topography development; b) ZY3 DSM can reflect terrain information over the Malyy Naryn River watershed in most detail and it has the best expression effect on the terrain among the three data sets of ZY3 DSM, SRTM DEM and ASTER GDEM, followed by SRTM DEM, and the effect of ASTER GDEM is the worst; c) The similarity of river networks extracted by ZY3 DSM and SRTM DEM is the highest, and the similarity between ZY3 DSM and ASTER GDEM is the lowest one.

The effects of wavelet compression on Digital Elevation Models (DEMs)

USGS Publications Warehouse

Oimoen, M.J.

2004-01-01

This paper investigates the effects of lossy compression on floating-point digital elevation models using the discrete wavelet transform. The compression of elevation data poses a different set of problems and concerns than does the compression of images. Most notably, the usefulness of DEMs depends largely in the quality of their derivatives, such as slope and aspect. Three areas extracted from the U.S. Geological Survey's National Elevation Dataset were transformed to the wavelet domain using the third order filters of the Daubechies family (DAUB6), and were made sparse by setting 95 percent of the smallest wavelet coefficients to zero. The resulting raster is compressible to a corresponding degree. The effects of the nulled coefficients on the reconstructed DEM are noted as residuals in elevation, derived slope and aspect, and delineation of drainage basins and streamlines. A simple masking technique also is presented, that maintains the integrity and flatness of water bodies in the reconstructed DEM.

A biopsychosocial vignette for case conceptualization in dementia (VIG-Dem): development and pilot study.

PubMed

Spector, Aimee; Hebditch, Molly; Stoner, Charlotte R; Gibbor, Luke

2016-09-01

The ability to identify biological, social, and psychological issues for people with dementia is an important skill for healthcare professionals. Therefore, valid and reliable measures are needed to assess this ability. This study involves the development of a vignette style measure to capture the extent to which health professionals use "Biopsychosocial" thinking in dementia care (VIG-Dem), based on the framework of the model developed by Spector and Orrell (2010). The development process consisted of Phase 1: Developing and refining the vignettes; Phase 2: Field testing (N = 9), and Phase 3: A pilot study to assess reliability and validity (N = 131). The VIG-Dem, consisting of two vignettes with open-ended questions and a standardized scoring scheme, was developed. Evidence for the good inter-rater reliability, convergent validity, and test-retest reliability were established. The VIG-Dem has good psychometric properties and may provide a useful tool in dementia care research and practice.

Error Analysis and Validation for Insar Height Measurement Induced by Slant Range

NASA Astrophysics Data System (ADS)

Zhang, X.; Li, T.; Fan, W.; Geng, X.

2018-04-01

InSAR technique is an important method for large area DEM extraction. Several factors have significant influence on the accuracy of height measurement. In this research, the effect of slant range measurement for InSAR height measurement was analysis and discussed. Based on the theory of InSAR height measurement, the error propagation model was derived assuming no coupling among different factors, which directly characterise the relationship between slant range error and height measurement error. Then the theoretical-based analysis in combination with TanDEM-X parameters was implemented to quantitatively evaluate the influence of slant range error to height measurement. In addition, the simulation validation of InSAR error model induced by slant range was performed on the basis of SRTM DEM and TanDEM-X parameters. The spatial distribution characteristics and error propagation rule of InSAR height measurement were further discussed and evaluated.

Analysis of Tire Tractive Performance on Deformable Terrain by Finite Element-Discrete Element Method

NASA Astrophysics Data System (ADS)

Nakashima, Hiroshi; Takatsu, Yuzuru

The goal of this study is to develop a practical and fast simulation tool for soil-tire interaction analysis, where finite element method (FEM) and discrete element method (DEM) are coupled together, and which can be realized on a desktop PC. We have extended our formerly proposed dynamic FE-DE method (FE-DEM) to include practical soil-tire system interaction, where not only the vertical sinkage of a tire, but also the travel of a driven tire was considered. Numerical simulation by FE-DEM is stable, and the relationships between variables, such as load-sinkage and sinkage-travel distance, and the gross tractive effort and running resistance characteristics, are obtained. Moreover, the simulation result is accurate enough to predict the maximum drawbar pull for a given tire, once the appropriate parameter values are provided. Therefore, the developed FE-DEM program can be applied with sufficient accuracy to interaction problems in soil-tire systems.

Verbesserte Visualisierung der Koronararterien in MSCT-Daten mit direkter Vergleichbarkeit zur Angiographie

NASA Astrophysics Data System (ADS)

Lacalli, Christina; Jähne, Marion; Wesarg, Stefan

In diesem Beitrag stellen wir neue, automatisierte Verfahren zur Visualisierung der Koronararterien einerseits und für eine direkte Vergleichbarkeit mit konventionellen Angiogrammen andererseits vor. Unser Ansatz umfasst Methoden für die automatische Extraktion des Herzens aus kontrastverstärkten CT-Daten, sowie für die Maskierung grosser kontrastmittelgefüllter Kavitäten des Herzens, um die Sichtbarkeit der Koronararterien bei der Darstellung mittels Volumenrendering zu verbessern. Zum direkten Vergleich mit konventionellen Angiographien wurde ein Verfahren zur automatischen Generierung von Projektionsansichten aus den CT-Daten entwickelt.

Pharmacological validation of individual animal locomotion, temperature and behavioural analysis in group-housed rats using a novel automated home cage analysis system: A comparison with the modified Irwin test.

PubMed

Tse, Karen; Sillito, Rowland; Keerie, Amy; Collier, Rachel; Grant, Claire; Karp, Natasha A; Vickers, Cathy; Chapman, Kathryn; Armstrong, J Douglas; Redfern, William S

2018-04-01

The ActualHCA™ system continuously monitors the activity, temperature and behavior of group-housed rats without invasive surgery. The system was validated to detect the contrasting effects of sedative and stimulant test agents (chlorpromazine, clonidine and amphetamine), and compared with the modified Irwin test (mIT) with rectal temperature measurements. Six male Han Wistar rats per group were used to assess each test agent and vehicle controls in separate ActualHCA™ recordings and mIT. The mIT was undertaken at 15, 30 mins, 1, 2, 4 and 24 h post-dose. ActualHCA™ recorded continuously for 24 h post-dose under 3 experimental conditions: dosed during light phase, dark phase, and light phase with a scheduled cage change at the time of peak effects determined by mIT. ActualHCA™ detected an increase stimulated activity from the cage change at 1-2 h post-dose which was obliterated by chlorpromazine and clonidine. Amphetamine increased activity up to 4 h post-dose in all conditions. Temperature from ActualHCA™ was affected by all test agents in all conditions. The mIT showed effects on all 3 test agents up to 4 h post-dose, with maximal effects at 1-2 h post-dose. The maximal effects on temperature from ActualHCA™ differed from mIT. Delayed effects on activity were detected by ActualHCA™, but not on mIT. Continuous monitoring has the advantage of capturing effects over time that may be missed with manual tests using pre-determined time points. This automated behavioural system does not replace the need for conventional methods but could be implemented simultaneously to improve our understanding of behavioural pharmacology. Copyright © 2018 Elsevier Inc. All rights reserved.

High-resolution topomapping of candidate MER landing sites with Mars Orbiter Camera narrow-angle images

USGS Publications Warehouse

Kirk, R.L.; Howington-Kraus, E.; Redding, B.; Galuszka, D.; Hare, T.M.; Archinal, B.A.; Soderblom, L.A.; Barrett, J.M.

2003-01-01

We analyzed narrow-angle Mars Orbiter Camera (MOC-NA) images to produce high-resolution digital elevation models (DEMs) in order to provide topographic and slope information needed to assess the safety of candidate landing sites for the Mars Exploration Rovers (MER) and to assess the accuracy of our results by a variety of tests. The mapping techniques developed also support geoscientific studies and can be used with all present and planned Mars-orbiting scanner cameras. Photogrammetric analysis of MOC stereopairs yields DEMs with 3-pixel (typically 10 m) horizontal resolution, vertical precision consistent with ???0.22 pixel matching errors (typically a few meters), and slope errors of 1-3??. These DEMs are controlled to the Mars Orbiter Laser Altimeter (MOLA) global data set and consistent with it at the limits of resolution. Photoclinometry yields DEMs with single-pixel (typically ???3 m) horizontal resolution and submeter vertical precision. Where the surface albedo is uniform, the dominant error is 10-20% relative uncertainty in the amplitude of topography and slopes after "calibrating" photoclinometry against a stereo DEM to account for the influence of atmospheric haze. We mapped portions of seven candidate MER sites and the Mars Pathfinder site. Safety of the final four sites (Elysium, Gusev, Isidis, and Meridiani) was assessed by mission engineers by simulating landings on our DEMs of "hazard units" mapped in the sites, with results weighted by the probability of landing on those units; summary slope statistics show that most hazard units are smooth, with only small areas of etched terrain in Gusev crater posing a slope hazard.

High-accuracy single-pass InSAR DEM for large-scale flood hazard applications

NASA Astrophysics Data System (ADS)

Schumann, G.; Faherty, D.; Moller, D.

2017-12-01

In this study, we used a unique opportunity of the GLISTIN-A (NASA airborne mission designed to characterizing the cryosphere) track to Greenland to acquire a high-resolution InSAR DEM of a large area in the Red River of the North Basin (north of Grand Forks, ND, USA), which is a very flood-vulnerable valley, particularly in spring time due to increased soil moisture content near state of saturation and/or, typical for this region, snowmelt. Having an InSAR DEM that meets flood inundation modeling and mapping requirements comparable to LiDAR, would demonstrate great application potential of new radar technology for national agencies with an operational flood forecasting mandate and also local state governments active in flood event prediction, disaster response and mitigation. Specifically, we derived a bare-earth DEM in SAR geometry by first removing the inherent far range bias related to airborne operation, which at the more typical large-scale DEM resolution of 30 m has a sensor accuracy of plus or minus 2.5 cm. Subsequently, an intelligent classifier based on informed relationships between InSAR height, intensity and correlation was used to distinguish between bare-earth, roads or embankments, buildings and tall vegetation in order to facilitate the creation of a bare-earth DEM that would meet the requirements for accurate floodplain inundation mapping. Using state-of-the-art LiDAR terrain data, we demonstrate that capability by achieving a root mean squared error of approximately 25 cm and further illustrating its applicability to flood modeling.

Assessment of the most recent satellite based digital elevation models of Egypt

NASA Astrophysics Data System (ADS)

Rabah, Mostafa; El-Hattab, Ahmed; Abdallah, Mohamed

2017-12-01

Digital Elevation Model (DEM) is crucial to a wide range of surveying and civil engineering applications worldwide. Some of the DEMs such as ASTER, SRTM1 and SRTM3 are freely available open source products. In order to evaluate the three DEMs, the contribution of EGM96 are removed and all DEMs heights are becoming ellipsoidal height. This step was done to avoid the errors occurred due to EGM96. 601 points of observed ellipsoidal heights compared with the three DEMs, the results show that the SRTM1 is the most accurate one, that produces mean height difference and standard deviations equal 2.89 and ±8.65 m respectively. In order to increase the accuracy of SRTM1 in EGYPT, a precise Global Geopotential Model (GGM) is needed to convert the SRTM1 ellipsoidal height to orthometric height, so that, we quantify the precision of most-recent released GGM (five models). The results show that, the GECO model is the best fit global models over Egypt, which produces a standard deviation of geoid undulation differences equals ±0.42 m over observed 17 HARN GPS/leveling stations. To confirm an enhanced DEM in EGYPT, the two orthometric height models (SRTM1 ellipsoidal height + EGM96) and (SRTM1 ellipsoidal height + GECO) are assessment with 17 GPS/leveling stations and 112 orthometric height stations, the results show that the estimated height differences between the SRTM1 before improvements and the enhanced model are at rate of 0.44 m and 0.06 m respectively.

A Prototype Tactile Sensor Array.

DTIC Science & Technology

1982-09-15

Active Touch Sensing. Technical Report, MIT Artificial Inteligence Laboratory, 1981. (9] Larcombe, M. Carbon Fibre Tactile Sensors. Technical Report...thesis, Carnegie-Mellon University, 1981. [13] Purbrick, John A. A Force Transducer Employing Conductive Silicone Rubber. Technical Report, MIT Artificial

Substrate-mediated strain effect on the role of thermal heating and electric field on metal-insulator transition in vanadium dioxide nanobeams.

PubMed

Kim, Min-Woo; Jung, Wan-Gil; Hyun-Cho; Bae, Tae-Sung; Chang, Sung-Jin; Jang, Ja-Soon; Hong, Woong-Ki; Kim, Bong-Joong

2015-06-04

Single-crystalline vanadium dioxide (VO2) nanostructures have recently attracted great attention because of their single domain metal-insulator transition (MIT) nature that differs from a bulk sample. The VO2 nanostructures can also provide new opportunities to explore, understand, and ultimately engineer MIT properties for applications of novel functional devices. Importantly, the MIT properties of the VO2 nanostructures are significantly affected by stoichiometry, doping, size effect, defects, and in particular, strain. Here, we report the effect of substrate-mediated strain on the correlative role of thermal heating and electric field on the MIT in the VO2 nanobeams by altering the strength of the substrate attachment. Our study may provide helpful information on controlling the properties of VO2 nanobeam for the device applications by changing temperature and voltage with a properly engineered strain.

Substrate-mediated strain effect on the role of thermal heating and electric field on metal-insulator transition in vanadium dioxide nanobeams

PubMed Central

Kim, Min-Woo; Jung, Wan-Gil; Hyun-Cho; Bae, Tae-Sung; Chang, Sung-Jin; Jang, Ja-Soon; Hong, Woong-Ki; Kim, Bong-Joong

2015-01-01

Single-crystalline vanadium dioxide (VO2) nanostructures have recently attracted great attention because of their single domain metal-insulator transition (MIT) nature that differs from a bulk sample. The VO2 nanostructures can also provide new opportunities to explore, understand, and ultimately engineer MIT properties for applications of novel functional devices. Importantly, the MIT properties of the VO2 nanostructures are significantly affected by stoichiometry, doping, size effect, defects, and in particular, strain. Here, we report the effect of substrate-mediated strain on the correlative role of thermal heating and electric field on the MIT in the VO2 nanobeams by altering the strength of the substrate attachment. Our study may provide helpful information on controlling the properties of VO2 nanobeam for the device applications by changing temperature and voltage with a properly engineered strain. PMID:26040637

MIT Clean Energy Prize: Final Technical Report May 12, 2010 - May 11, 2011

DOE Office of Scientific and Technical Information (OSTI.GOV)

Snyder, Chris; Campbell, Georgina; Salony, Jason

2011-08-09

The MIT Clean Energy Prize (MIT CEP) is a venture creation and innovation competition to encourage innovation in the energy space, specifically with regard to clean energy. The Competition invited student teams from any US university to submit student-led ventures that demonstrate a high potential of successfully making clean energy more affordable, with a positive impact on the environment. By focusing on student ventures, the MIT CEP aims to educate the next generation of clean energy entrepreneurs. Teams receive valuable mentoring and hard deadlines that complement the cash prize to accelerate development of ventures. The competition is a year-long educationalmore » process that culminates in the selection of five category finalists and a Grand Prize winner and the distribution of cash prizes to each of those teams. Each entry was submitted in one of five clean energy categories: Renewables, Clean Non-Renewables, Energy Efficiency, Transportation, and Deployment.« less

Mapping hydrological environments in central Amazonia: ground validation and surface model based on SRTM DEM data corrected for deforestation

NASA Astrophysics Data System (ADS)

Moulatlet, G. M.; Rennó, C. D.; Costa, F. R. C.; Emilio, T.; Schietti, J.

2014-07-01

One of the most important freely available digital elevation models (DEMs) for Amazonia is the one obtained by the Shuttle Radar Topography Mission (SRTM). However, since SRTM tends to represent the vegetation surface instead of the ground surface, the broad use of SRTM DEM as a framework for terrain description in Amazonia is hampered by the presence of deforested areas. We present here two datasets: (1) a deforestation-corrected SRTM DEM for the interfluve between the Purus and Madeira rivers, in central Amazonia, which passed through a careful identification of different environments and has deforestation features corrected by a new method of increasing pixel values of the DEM; and (2) a set of eighteen hydrological-topographic descriptors based on the corrected SRTM DEM. The hydrological-topographic description was generated by the Height Above the Nearest Drainage (HAND) algorithm, which normalizes the terrain elevation (a.s.l.) by the elevation of the nearest hydrologically connected drainage. The validation of the HAND dataset was done by in situ hydrological description of 110 km of walking trails also available in this dataset. The new SRTM DEM expands the applicability of SRTM data for landscape modelling; and the datasets of hydrological features based on topographic modelling is undoubtedly appropriate for ecological modelling and an important contribution for environmental mapping of Amazonia. The deforestation-corrected SRTM DEM is available at http://ppbio.inpa.gov.br/knb/metacat/naman.318.3/ppbio; the polygons selected for deforestation correction are available at http://ppbio.inpa.gov.br/knb/metacat/naman.317.3/ppbio; the set of hydrological-topographic descriptors is available at http://ppbio.inpa.gov.br/knb/metacat/naman.544.2/ppbio; and the environmental description of access trails is available at http://ppbio.inpa.gov.br/knb/metacat/naman.541.2/ppbio.

Comparative costs of the Mouse Inoculation Test (MIT) and Virus Isolation in Cell Culture (VICC) for use in rabies diagnosis in Brazil.

PubMed

Bones, Vanessa C; Gameiro, Augusto H; Castilho, Juliana G; Molento, Carla F M

2015-05-01

The decision to use laboratory animals rather than in vitro methods is frequently based on the financial costs involved, so the objective of our study was to compare the costs of performing the Mouse Inoculation Test (MIT) and Virus Isolation in Cell Culture (VICC) for use in rabies diagnosis in Brazil. Based on observations of laboratory routines at the Pasteur Institute, São Paulo, we listed the fixed cost (FC) and variable cost (VC) items necessary to perform both tests. Considering that 200 MITs are equivalent to 350 VICC assays, in terms of facilities and staff-hours needed per month, we calculated, for both tests, the average total cost per sample, the costs of the implementation of the laboratory structure, and the costs of routine use. With regard to absolute values, the total cost was mainly influenced by FC items, as they represented 60% of the cost for the MIT and 86% of the cost for VICC. A sample analysed by the MIT costs around 205% more than one analysed by using VICC. The MIT costs 74% and 406% more than VICC, when implementation costs and routine use per month, respectively, are taken into account. Our results can assist in the resolution of costing disputes that could hinder the replacement of animals for rabies diagnosis in Brazil. The method demonstrated here might also be useful for cost comparisons in other situations where animal use still continues when validated alternatives exist. 2015 FRAME.

78 FR 57850 - Product Cancellation Order for Certain Pesticide Registrations

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-20

... Microbiocide. hydrochloride. 062190-00032 Arch CMIT/MIT........ 5-Chloro-2-methyl- 3(2H)-isothiazolone, 2-Methyl-3(2H)- isothiazolone. 062190-00035 Arch CMIT/MIT 14 MUP. 2-Methyl-3(2H)- isothiazolone, 5- Chloro...

Energy Systems Integration News | Energy Systems Integration Facility |

Science.gov Websites

NREL group of children in front of a 3D visualization screen. Students from the OpenWorld Learning group interact with a wind turbine wind velocity simulation at the 3D visualization lab at the

Application of phyto-indication and radiocesium indicative methods for microrelief mapping

NASA Astrophysics Data System (ADS)

Panidi, E.; Trofimetz, L.; Sokolova, J.

2016-04-01

Remote sensing technologies are widely used for production of Digital Elevation Models (DEMs), and geomorphometry techniques are valuable tools for DEM analysis. One of the broadly used applications of these technologies and techniques is relief mapping. In the simplest case, we can identify relief structures using DEM analysis, and produce a map or map series to show the relief condition. However, traditional techniques might fail when used for mapping microrelief structures (structures below ten meters in size). In this case high microrelief dynamics lead to technological and conceptual difficulties. Moreover, erosion of microrelief structures cannot be detected at the initial evolution stage using DEM modelling and analysis only. In our study, we investigate the possibilities and specific techniques for allocation of erosion microrelief structures, and mapping techniques for the microrelief derivatives (e.g. quantitative parameters of microrelief). Our toolset includes the analysis of spatial redistribution of the soil pollutants and phyto-indication analysis, which complement the common DEM modelling and geomorphometric analysis. We use field surveys produced at the test area, which is arable territory with high erosion risks. Our main conclusion at the current stage is that the indicative methods (i.e. radiocesium and phyto-indication methods) are effective for allocation of the erosion microrelief structures. Also, these methods need to be formalized for convenient use.

Thermal Diagnostics with the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory: A Validated Method for Differential Emission Measure Inversions

NASA Astrophysics Data System (ADS)

Cheung, Mark C. M.; Boerner, P.; Schrijver, C. J.; Testa, P.; Chen, F.; Peter, H.; Malanushenko, A.

2015-07-01

We present a new method for performing differential emission measure (DEM) inversions on narrow-band EUV images from the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory. The method yields positive definite DEM solutions by solving a linear program. This method has been validated against a diverse set of thermal models of varying complexity and realism. These include (1) idealized Gaussian DEM distributions, (2) 3D models of NOAA Active Region 11158 comprising quasi-steady loop atmospheres in a nonlinear force-free field, and (3) thermodynamic models from a fully compressible, 3D MHD simulation of active region (AR) corona formation following magnetic flux emergence. We then present results from the application of the method to AIA observations of Active Region 11158, comparing the region's thermal structure on two successive solar rotations. Additionally, we show how the DEM inversion method can be adapted to simultaneously invert AIA and Hinode X-ray Telescope data, and how supplementing AIA data with the latter improves the inversion result. The speed of the method allows for routine production of DEM maps, thus facilitating science studies that require tracking of the thermal structure of the solar corona in time and space.

Towards a unified estimate of arctic glaciers contribution to sea level rise since 1972.

NASA Astrophysics Data System (ADS)

Dehecq, A.; Gardner, A. S.; Alexandrov, O.; McMichael, S.

2017-12-01

Glaciers retreat contributed to about 1/3 of the observed sea level rise since 1971 (IPCC). However, long term estimates of glaciers volume changes rely on sparse field observations and region-wide satellite observations are available mostly after 2000. The recently declassified images from the reconnaissance satellite series Hexagon (KH9), that acquired 6 m resolution stereoscopic images from 1971 to 1986, open new possibilities for glaciers observation. But the film-printed images represent a processing challenge. Here we present an automatic workflow developed to generate Digital Elevation Models (DEMs) at 24 m resolution from the raw scanned KH9 images. It includes a preprocessing step to detect fiducial marks and to correct distortions of the film caused by the 40-year storage. An estimate of the unknown satellite position is obtained from a crude geolocation of the images. Each stereo image pair/triplet is then processed using the NASA Ames Stereo Pipeline to derive an unscaled DEM using standard photogrammetric techniques. This DEM is finally aligned to a reference topography, to account for errors in translation, rotation and scaling. In a second part, we present DEMs generated over glaciers in the Canadian Arctic and analyze glaciers volume changes from 1970 to the more recent WorldView ArcticDEM.

A positional estimation technique for an autonomous land vehicle in an unstructured environment

NASA Technical Reports Server (NTRS)

Talluri, Raj; Aggarwal, J. K.

1990-01-01

This paper presents a solution to the positional estimation problem of an autonomous land vehicle navigating in an unstructured mountainous terrain. A Digital Elevation Map (DEM) of the area in which the robot is to navigate is assumed to be given. It is also assumed that the robot is equipped with a camera that can be panned and tilted, and a device to measure the elevation of the robot above the ground surface. No recognizable landmarks are assumed to be present in the environment in which the robot is to navigate. The solution presented makes use of the DEM information, and structures the problem as a heuristic search in the DEM for the possible robot location. The shape and position of the horizon line in the image plane and the known camera geometry of the perspective projection are used as parameters to search the DEM. Various heuristics drawn from the geometric constraints are used to prune the search space significantly. The algorithm is made robust to errors in the imaging process by accounting for the worst care errors. The approach is tested using DEM data of areas in Colorado and Texas. The method is suitable for use in outdoor mobile robots and planetary rovers.

Ice dynamics of Himalayan glaciers (Himachal Pradesh, India) using TerraSAR-X/TanDEM-X data.

NASA Astrophysics Data System (ADS)

Vijay, Saurabh; Braun, Matthias

2015-04-01

Mountain glaciers are the natural indicators of climate change. Himalaya is a part of widely spread mountain range consisting of second largest ice mass after polar region. The glaciers in Himalaya are located in Himachal Pradesh and other territories of India. The precipitation in the region is influenced by both Indian summer monsoon and mid-latitude winter westerlies. The glacier discharge influences the river basins and provides fresh water for various infrastructural necessities of urbanization in the state. The study aims to estimate the ice thickness and volume change during the decade (2011-2000) and annually during 2011-2014. For this, TanDEM-X DEMs are subtracted from the SRTM C/X band DEM of 2000. In addition, ice flow dynamics are quantified by the constellation of TerraSAR-X/TanDEM-X data using SAR offset tracking method. The primary investigations reveal that the terminus velocity of Bada Shigri (G077683E32169N), the biggest glacier of the state, Chhota Shigri( G077513E32227N), a bench-mark glacier, and other glacier (G077547E32162N) in 2011 found out to be < 2cm/day. The upper stream velocities of the glaciers are increased linearly and influenced by glacier tributaries.

THERMAL DIAGNOSTICS WITH THE ATMOSPHERIC IMAGING ASSEMBLY ON BOARD THE SOLAR DYNAMICS OBSERVATORY: A VALIDATED METHOD FOR DIFFERENTIAL EMISSION MEASURE INVERSIONS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cheung, Mark C. M.; Boerner, P.; Schrijver, C. J.

We present a new method for performing differential emission measure (DEM) inversions on narrow-band EUV images from the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory. The method yields positive definite DEM solutions by solving a linear program. This method has been validated against a diverse set of thermal models of varying complexity and realism. These include (1) idealized Gaussian DEM distributions, (2) 3D models of NOAA Active Region 11158 comprising quasi-steady loop atmospheres in a nonlinear force-free field, and (3) thermodynamic models from a fully compressible, 3D MHD simulation of active region (AR) corona formation following magneticmore » flux emergence. We then present results from the application of the method to AIA observations of Active Region 11158, comparing the region's thermal structure on two successive solar rotations. Additionally, we show how the DEM inversion method can be adapted to simultaneously invert AIA and Hinode X-ray Telescope data, and how supplementing AIA data with the latter improves the inversion result. The speed of the method allows for routine production of DEM maps, thus facilitating science studies that require tracking of the thermal structure of the solar corona in time and space.« less

Remote sensing analysis of depositional landforms in alluvial settings: Method development and application to the Taquari megafan, Pantanal (Brazil)

NASA Astrophysics Data System (ADS)

Zani, Hiran; Assine, Mario Luis; McGlue, Michael Matthew

2012-08-01

Traditional Shuttle Radar Topography Mission (SRTM) topographic datasets hold limited value in the geomorphic analysis of low-relief terrains. To address this shortcoming, this paper presents a series of techniques designed to enhance digital elevation models (DEMs) of environments dominated by low-amplitude landforms, such as a fluvial megafan system. These techniques were validated through the study of a wide depositional tract composed of several megafans located within the Brazilian Pantanal. The Taquari megafan is the most remarkable of these features, covering an area of approximately 49,000 km2. To enhance the SRTM-DEM, the megafan global topography was calculated and found to be accurately represented by a second order polynomial. Simple subtraction of the global topography from altitude produced a new DEM product, which greatly enhanced low amplitude landforms within the Taquari megafan. A field campaign and optical satellite images were used to ground-truth features on the enhanced DEM, which consisted of both depositional (constructional) and erosional features. The results demonstrate that depositional lobes are the dominant landforms on the megafan. A model linking baselevel change, avulsion, clastic sedimentation, and erosion is proposed to explain the microtopographic features on the Taquari megafan surface. The study confirms the potential promise of enhanced DEMs for geomorphological research in alluvial settings.

An outlet breaching algorithm for the treatment of closed depressions in a raster DEM

NASA Astrophysics Data System (ADS)

Martz, Lawrence W.; Garbrecht, Jurgen

1999-08-01

Automated drainage analysis of raster DEMs typically begins with the simulated filling of all closed depressions and the imposition of a drainage pattern on the resulting flat areas. The elimination of closed depressions by filling implicitly assumes that all depressions are caused by elevation underestimation. This assumption is difficult to support, as depressions can be produced by overestimation as well as by underestimation of DEM values.This paper presents a new algorithm that is applied in conjunction with conventional depression filling to provide a more realistic treatment of those depressions that are likely due to overestimation errors. The algorithm lowers the elevation of selected cells on the edge of closed depressions to simulate breaching of the depression outlets. Application of this breaching algorithm prior to depression filling can substantially reduce the number and size of depressions that need to be filled, especially in low relief terrain.Removing or reducing the size of a depression by breaching implicitly assumes that the depression is due to a spurious flow blockage caused by elevation overestimation. Removing a depression by filling, on the other hand, implicitly assumes that the depression is a direct artifact of elevation underestimation. Although the breaching algorithm cannot distinguish between overestimation and underestimation errors in a DEM, a constraining parameter for breaching length can be used to restrict breaching to closed depressions caused by narrow blockages along well-defined drainage courses. These are considered the depressions most likely to have arisen from overestimation errors. Applying the constrained breaching algorithm prior to a conventional depression-filling algorithm allows both positive and negative elevation adjustments to be used to remove depressions.The breaching algorithm was incorporated into the DEM pre-processing operations of the TOPAZ software system. The effect of the algorithm is illustrated by the application of TOPAZ to a DEM of a low-relief landscape. The use of the breaching algorithm during DEM pre-processing substantially reduced the number of cells that needed to be subsequently raised in elevation to remove depressions. The number and kind of depression cells that were eliminated by the breaching algorithm suggested that the algorithm effectively targeted those topographic situations for which it was intended. A detailed inspection of a portion of the DEM that was processed using breaching algorithm in conjunction with depression-filling also suggested the effects of the algorithm were as intended.The breaching algorithm provides an empirically satisfactory and robust approach to treating closed depressions in a raster DEM. It recognises that depressions in certain topographic settings are as likely to be due to elevation overestimation as to elevation underestimation errors. The algorithm allows a more realistic treatment of depressions in these situations than conventional methods that rely solely on depression-filling.

Internationalizing Practical ChE Education: The M.I.T. Practice School in Japan.

ERIC Educational Resources Information Center

O'Connor, Andrea J.; Kandas, Angelo W.; Natori, Yukikazu; Hatton, T. Alan

1999-01-01

Describes the establishment, benefits, and difficulties of an overseas branch of the Massachusetts Institute of Technology's (MIT) chemical engineering Practice School for student internship study at the Mitsubishi Chemical Corporation's Mizushima Plant in Kurashiki, Japan. (WRM)

Turning Europe"s innovation dream into a working reality

NASA Astrophysics Data System (ADS)

Tindemans, Peter

2008-08-01

Opened in 1865 after the American Civil War, the world renowned Massachusetts Institute of Technology (MIT) aimed to provide a flow of ideas from academic research to industry in response to increasing industrialization in the US. Since then, more than 71 Nobel laureates have passed through MIT's doors and it now has a budget of 2.2bn per year that is spent on teaching, knowledge creation and technological innovation. Given its success, it is no wonder then that Europe has plans to replicate the MIT model and create a similar European institute of its own.

New insight into enhanced superconductivity in metals near the metal-insulator transition.

PubMed

Osofsky, M S; Soulen, R J; Claassen, J H; Trotter, G; Kim, H; Horwitz, J S

2001-11-05

We have studied the transport properties of disordered WSi films near the metal/insulator transition (MIT) and we have also reviewed the data for several other disordered materials near their MIT. In all cases, we found the presence of enhanced superconductivity. We constructed a superconductivity "phase diagram" (i.e., T(c) versus sigma) for each system, which reveals a striking correlation: In all cases, T(c) values are significantly enhanced only for samples whose conductivities lie within a narrow range on the metallic side of, and moderately near, the MIT. We present a heuristic model to explain this phenomenon.

MIT Space Engineering Research Center

NASA Technical Reports Server (NTRS)

Crawley, Edward F.; Miller, David W.

1990-01-01

The Space Engineering Research Center (SERC) at MIT, started in Jul. 1988, has completed two years of research. The Center is approaching the operational phase of its first testbed, is midway through the construction of a second testbed, and is in the design phase of a third. We presently have seven participating faculty, four participating staff members, ten graduate students, and numerous undergraduates. This report reviews the testbed programs, individual graduate research, other SERC activities not funded by the Center, interaction with non-MIT organizations, and SERC milestones. Published papers made possible by SERC funding are included at the end of the report.