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Sample records for quantitative bestimmung von

  1. Von Willebrand's disease: a novel mutation, P1824H and the incidence of R1205H defect among families with dominant quantitative von Willebrand factor deficiency.

    PubMed

    Casaña, Pilar; Cabrera, Noelia; Haya, Saturnino; Cid, Ana Rosa; Aznar, José Antonio

    2006-08-01

    To date, few mutations associated with a dominant quantitative deficiency of von Willebrand factor (VWF) and a high penetrance have been reported. This phenotype was confirmed in seven unrelated families of several patients diagnosed with von Willebrand's disease out of 70 who requested genetic studies of the VWF gene. The mutations linked to this type were identified: R1205H in five families; T1156M in one family; and the new P1824H alteration in one other family. The R1205H mutation linked to the different haplotypes might well be frequent among this variant. The P1824H in the A3 domain is associated with very low VWF levels and with a moderate-to-severe bleeding tendency, unlike the other mutations reported in this domain.

  2. Quantitative Influence of ABO Blood Groups on Factor VIII and Its Ratio to von Willebrand Factor, Novel Observations from an ARIC Study of 11,673 Subjects.

    PubMed

    Song, Jaewoo; Chen, Fengju; Campos, Marco; Bolgiano, Doug; Houck, Katie; Chambless, Lloyd E; Wu, Kenneth K; Folsom, Aaron R; Couper, David; Boerwinkle, Eric; Dong, Jing-fei

    2015-01-01

    ABO blood groups are known to influence the plasma level of von Willebrand factor (VWF), but little is known about the relationship between ABO and coagulation factor VIII (FVIII). We analyzed the influence of ABO genotypes on VWF antigen, FVIII activity, and their quantitative relationship in 11,673 participants in the Atherosclerosis Risk in Communities (ARIC) study. VWF, FVIII, and FVIII/VWF levels varied significantly among O, A (A1 and A2), B and AB subjects, and the extent of which varied between Americans of European (EA) and African (AA) descent. We validated a strong influence of ABO blood type on VWF levels (15.2%), but also detected a direct ABO influence on FVIII activity (0.6%) and FVIII/VWF ratio (3.8%) after adjustment for VWF. We determined that FVIII activity changed 0.54% for every 1% change in VWF antigen level. This VWF-FVIII relationship differed between subjects with O and B blood types in EA, AA, and in male, but not female subjects. Variations in FVIII activity were primarily detected at low VWF levels. These new quantitative influences on VWF, FVIII and the FVIII/VWF ratio help understand how ABO genotypes differentially influence VWF, FVIII and their ratio, particularly in racial and gender specific manners.

  3. Quantitative Influence of ABO Blood Groups on Factor VIII and Its Ratio to von Willebrand Factor, Novel Observations from an ARIC Study of 11,673 Subjects

    PubMed Central

    Campos, Marco; Bolgiano, Doug; Houck, Katie; Chambless, Lloyd E.; Wu, Kenneth K.; Folsom, Aaron R.; Couper, David; Boerwinkle, Eric; Dong, Jing-fei

    2015-01-01

    ABO blood groups are known to influence the plasma level of von Willebrand factor (VWF), but little is known about the relationship between ABO and coagulation factor VIII (FVIII). We analyzed the influence of ABO genotypes on VWF antigen, FVIII activity, and their quantitative relationship in 11,673 participants in the Atherosclerosis Risk in Communities (ARIC) study. VWF, FVIII, and FVIII/VWF levels varied significantly among O, A (A1 and A2), B and AB subjects, and the extent of which varied between Americans of European (EA) and African (AA) descent. We validated a strong influence of ABO blood type on VWF levels (15.2%), but also detected a direct ABO influence on FVIII activity (0.6%) and FVIII/VWF ratio (3.8%) after adjustment for VWF. We determined that FVIII activity changed 0.54% for every 1% change in VWF antigen level. This VWF-FVIII relationship differed between subjects with O and B blood types in EA, AA, and in male, but not female subjects. Variations in FVIII activity were primarily detected at low VWF levels. These new quantitative influences on VWF, FVIII and the FVIII/VWF ratio help understand how ABO genotypes differentially influence VWF, FVIII and their ratio, particularly in racial and gender specific manners. PMID:26244499

  4. Reaktive Tracer zur Bestimmung der sedimentären Aquifer-Oxidationskapazität im Labor- und Feldversuch

    NASA Astrophysics Data System (ADS)

    Dethlefsen, Frank; Bliss, Fabian; Wachter, Thorsten; Dahmke, Andreas

    Kurzfassung Mikrobiell reduzierbares Eisen(III) im Aquifer kann als Elektronenakzeptor von großer Bedeutung für Natural Attenuation (NA) von aromatischen Kohlenwasserstoffen sein und bildet den Hauptbestandteil der sedimentären Oxidationskapazität (OXC) des Aquifers. Untersuchungsgegenstand war der Vergleich traditioneller, nasschemischer Methoden mit neuentwickelten, reaktiven Tracerverfahren zur Bestimmung der sedimentären OXC. Die innovativen Tracermethoden haben gegenüber nasschemischen Extraktionsverfahren den prinzipiellen Vorteil, dass sie einen integralen Ansatz zur Bestimmung der sedimentären OXC bilden, weil geochemische und hydraulische Heterogenitäten des Aquifers berücksichtigt werden. Daher wurden am RETZINA-Standort Zeitz einerseits herkömmliche Säure-Extraktionsmethoden (bestimmter Eisen(III)-Gehalt: 0,43 +/- 0,07 mg/g Aquifermaterial) und andererseits reaktive Tracertests mit Phosphat-(Eisen(III): 1,0 mg/g) und Sulfidtracern (Eisen(III): 0,31 +/- 0,02 mg/g) in Laborversuchen sowie Bioabbauversuche mit Toluol als Kohlenstoffquelle undGeobacter metallireducensals Eisen(III)-Reduzierer (Eisen(III): 1,0 mg/g) durchgeführt. Sulfid als reaktiver Tracer wurde in Form eines 〝Push-Pull-Tests`` im Feldversuch eingesetzt (Eisen(III): 1,1 mg/g). Zudem bedeutet die Anwendung des Feld-Tracerverfahrens deutlich weniger Zeitaufwand in der Durchführung als die Anwendung traditioneller Extraktionsmethoden. Microbially reducible iron(III) is important as a terminal electron acceptor for the Natural Attenuation (NA) of aromatic hydrocarbons and forms the balance of the aquifer's sedimentary oxidation capacity (OXC). It was the aim of this investigation to compare traditional acid extraction methods to reactive tracer methods in quantifying the sedimentary OXC. The sedimentary OXC at the RETZINA test site in Zeitz was therefore determined through traditional acid extraction methods (determined Iron(III)-content: 0.43 +/- 0.07 mg/g aquifer material) and

  5. 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

  6. Periodisches Hitzdrahtverfahren zur Messung von Wärme- und Temperaturleitfähigkeit von geringen Stoffmengen

    NASA Astrophysics Data System (ADS)

    Griesinger, A.; Spindler, K.; Hahne, E.

    Zusammenfassung Es wird ein Meßverfahren zur gleichzeitigen Bestimmung der Wärme- und der Temperaturleitfähigkeit von geringen Stoffmengen beschrieben. Neben Messungen an hochviskosen Flüssigkeiten eignet sich das Verfahren besonders für Messungen an Pulver-Schüttungen. Das Meßverfahren basiert auf dem transienten Hitzdraht-Verfahren. In einem dünnen Platindraht fließt ein sinusförmiger Wechselstrom, der den Draht periodisch erwärmt. Es entstehen thermische Wellen, die in die umgebende Probe eindringen. Die Amplitude und die Phasenlage der thermischen Wellen in der Probe hängen von der Temperaturleitfähigkeit a und der Wärmeleitfähigkeit λ der Probe ab. Die Temperaturschwingung in der Probe wird mit Hilfe des Platindrahtes gemessen, der gleichzeitig als Widerstandsthermometer eingesetzt wird. Meßwerte von Wasser und Glycerin zeigen eine gute Übereinstimmung mit Literaturwerten. Das Meßverfahren zeichnet sich dadurch aus, daß zur Bestimmung der Wärme- und Temperaturleitfähigkeit nur 13 ml einer Probe benötigt werden. Es werden Meßwerte einer Zeolith-Schüttung unter Wasserstoffbeladung dargestellt. A measuring procedure for the simultaneous determination of the thermal conductivity and thermal diffusivity of small quantities is described. The procedure is suited for high-viscous fluids and for powdery material. The measuring principle is based on the transient hot-wire method. A sinusoidal alternating current flows through a thin platinum wire and heats up the wire periodically. This results in thermal waves, which penetrate into the surrounding sample. The amplitude and the phase shift of the thermal waves depend on the thermal diffusivity ``a'' and the thermal conductivity ``λ'' of the sample. The temperature oscillation in the sample is measured by means of the platinum wire, which is simultaneously applied as a resistance thermometer. The values measured for water and glycerine correspond well to those given in literature. Results of the

  7. Berechnung von Nichtlinearitätsparametern von RF MOS Mischern mittels Volterra-Reihen

    NASA Astrophysics Data System (ADS)

    Susic, A.; Darrat, A. H.; Mathis, W.

    2011-07-01

    Die Nichtlinearität einer Mischerschaltung bezüglich des Informationssignals führt zu unerwünschten Spektralanteilen am Ausgang des Mischers. Da nicht alle Spektralanteile kritisch sind, müssen bei einer Nichtlinearitätsanalyse nur bestimmte Spektralanteile ermittelt werden. In dieser Arbeit wird ein Verfahren zur Bestimmung der Spektralanteile der Zustandsgrößen im Mischer mit Hilfe der Volterra-Reihe gezeigt. Das Verfahren basiert auf die Methode der nichtlinearen Stromquellen. Es wird sowohl auf nicht-schaltende als auch schaltende Mischer angewendet. Hierbei wird der erste als ein zeitinvariantes System mit zwei Eingängen und der zweite als ein periodisch zeitvariantes System mit einem Eingang modelliert. Das Verfahren wird in dem Computeralgebraprogramm MAPLE für den einfach balancierten MOS Mischer implementiert. Es ermöglicht die Herleitung von semi-symbolischen Ausdrücken für die Spektralanteile in Abhängigkeit von den Entwurfsparametern. Die numerischen Ergebnisse des Verfahrens werden gegenüber Simulationen mit SpectreRF verglichen.

  8. von Willebrand factor and von Willebrand disease.

    PubMed

    Matsui, Taei; Hamako, Jiharu

    von Willebrand factor (VWF) has two major roles in hemostasis, as a form of molecular glue which functions in platelet plug formation and as a protective transporter for coagulation factor VIII (FVIII). VWF shows a multimeric chain structure composed of 270 kDa subunits containing binding domains for FVIII, platelet and collagens. Biosynthesis, storage, secretion of VWF and the cleavage process by ADAMTS13 (a disintegrin-like and metalloproteinase with thrombospondin type 1 repeats 13) regulating VWF activity have been elucidated. von Willebrand disease (VWD) is an autosomal bleeding disorder, first documented in 1926, caused by quantitative or qualitative deficiency of VWF. The classification and molecular pathogenesis of VWD have been developed during a 90-year period based on clinical laboratory analysis of VWF, and structure-function analysis of mutant VWF with amino acid substitutions (genetic changes). VWF is a unique and very large multifunctional plasma protein, the hemostatic activity of which is dynamically regulated by physiological shear stress in the blood stream.

  9. von Willebrand Disease

    MedlinePlus

    ... from the NHLBI on Twitter. What Is Von Willebrand Disease? Von Willebrand disease (VWD) is a bleeding disorder. ... while hemophilia mainly affects males. Types of von Willebrand Disease The three major types of VWD are called ...

  10. Wernher von Braun

    NASA Image and Video Library

    1967-06-06

    Throughout his career, Dr. von Braun received numerous awards for his contributions to space flight. On June 6, 1967, Dr. Fred L. Whipple, Director of the Smithsonian Astrophysical Observatory, presented Dr. von Braun with the Smithsonian Langley Medal.

  11. Wernher von Braun

    NASA Image and Video Library

    1945-04-01

    Dr. Wernher von Braun surrenders to U.S. Army Counterintelligence persornel of the 44th Infantry Division in Ruette, Bavaria on May 2, 1945. Left to right are Charles Stewart, CIC agent; Dr. Herbert Axster; Dieter Huzel; Dr. von Braun (arm in cast); Magnus von Braun (brother); and Hans Lindenberg.

  12. Diagnostische Präzision der komponentenbasierten vs. der extraktbasierten In-vitro-Diagnostik von Insektengift-Allergien: Auswirkungen auf das klinische Management.

    PubMed

    Seyfarth, Florian; Miguel, Diana; Schliemann, Sibylle; Hipler, Uta-Christina

    2017-05-01

    Die Bestimmung von spezifischen IgE-Antikörpern spielt eine zentrale Bedeutung bei der Diagnostik von Bienen- und Wespengiftallergien. In den letzten Jahren wurden die komponentenbasierte Diagnostik (CRD) eingeführt, die die Bestimmung spezifischer IgE-Antikörper gegen die Allergene Api m 1, Ves v 1, Ves v 5 und Pol d 5 sowie kreuzreaktive Kohlenhydratdeterminanten (CCDs) erlaubt. Hierdurch soll vor allem bei Probanden mit Doppelsensibilisierungen die klinische Relevanz der einzelnen Sensibilisierungen besser beurteilt werden können. Die spezifischen IgE-Antikörper-Bestimmungen an 143 Probanden mit Bienen- und/oder Wespengiftallergie erfolgten mit den extraktbasierten ImmunoCAP®-Allergenen i1 und i3 sowie den ImmunoCAP®-Allergenkomponenten i208-211 und o214 (Api m 1, Ves v 1, Ves v 5, Pol d 5, CCD). Bei Doppelsensibilisierten wurde zusätzlich ein Inhibitionstest durchgeführt. An einem Teilkollektiv der Studienpopulation erfolgten sIgE-Bestimmungen gegen Api m 1, Api m 4, Pol d 5 und Ves v 5 mittels Allergiechip (ISAC®, n  =  44). Die Sensitivität von Ves v 5 bei isolierten Wespengiftallergikern betrug 78,5 %, gemeinsam mit Ves v 1 stieg diese auf 92,3 %. Die Sensitivität von Api m 1 bei isolierten Bienengiftallergikern betrug 25 %. Die komponentenbasierte Diagnostik und Inhibitionstests bei Doppelsensibilisierten lieferten divergente Ergebnisse. Die CRD mittels ISAC®-Allergiechip erbrachte deutliche Unterschiede vor allem im Hinblick auf die Diagnostik von Api m 1 und CCDs. Die CRD bereichert das diagnostische Spektrum, sofern sie nicht allein sondern zusätzlich zu den etablierten Verfahren eingesetzt wird. Sie sollte neben Ves v 5 stets die Bestimmung der IgE-Antikörper gegen Ves v 1 umfassen. © 2017 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.

  13. Wernher von Braun

    NASA Image and Video Library

    1970-02-24

    In 1970 Marshall Space Flight Center (MSFC) Director Dr. Wernher von Braun (right) was reassigned to NASA Headquarters to serve as Deputy Associate Administrator for Plarning. Prior to his transfer, Dr. von Braun was honored for his career in Huntsville, Alabama, with the celebration of "Wernher von Braun Day." Among those participating were Alabama Governor Albert Brewer (left) and Alabama Senator John Sparkman (center). (Courtesy of Huntsville/Madison County Public library)

  14. Wernher von Braun

    NASA Image and Video Library

    1954-01-01

    Marshall Center Director Dr. Wernher Von Braun is pictured with Walt Disney during a visit to the Marshall Space Flight Center in 1954. In the 1950s, Dr. Von Braun while working in California on the Saturn project, also worked with Disney studios as a technical director in making three films about Space Exploration for television. Disney's tour of Marshall in 1965 was Von Braun's hope for a renewed public interest in the future of the Space Program at NASA.

  15. Theodore von Karman

    NASA Technical Reports Server (NTRS)

    1926-01-01

    Theodore von Karman. NACA: In the eyes of most aeronautical experts, the overall record of Max Munk in aerodynamic research falls short of that achieved by fellow immigrant Theodore von Karman (the short man in the double breasted coat in the middle), shown here visiting Langley in December 1926. People in the photo include Max Munk, aerodynamic researcher; Theodore von Karman; George Lewis, director of research; Henry Reid, engineer in charge; Fred Weick, PRT head; Paul Hemke; Elliott Reid, future Stanford University Professor.

  16. Wernher von Braun

    NASA Image and Video Library

    1970-02-24

    In February 1970, MSFC Director Dr. von Braun was named NASA Deputy Associate Administrator for Plarning and transferred to the Agency's Headquarters in Washington D.C. Prior to his departure, Huntsvillians, along with state local dignitaries, honored his years of service to the Army and NASA with a series of events. One included unveiling a plaque in von Braun's honor. Pictured with Dr. von Braun are (left to right), his daughter Iris, wife Maria, U.S. Senator John Sparkman and Alabama Governor Albert Brewer, Dr. von Braun, son Peter, and daughter Margrit.

  17. Rheologie von Beschichtungen

    NASA Astrophysics Data System (ADS)

    Schäffler, Michael

    Die Rheologie beschreibt die Fließ- und Deformationseigenschaften von Materialien. Der Begriff Rheologie ist aus dem Griechischen abgeleitet: rhein - fließen. Erst im Jahre 1930 entwickelte E.C. Bingham und M. Reiner in Easton (USA) die Rheologie zu einer eigenständigen Wissenschaft. Aber bereits seit dem 17. Jahrhundert wurden wesentliche Einzelbeiträge zu Fließphänomenen veröffentlich, so z.B. 1676 von R. Hooke (Hookesches Gesetz) und 1687 von I. Newton (Newtonsches Gesetz). Die Rheologie hat sich bis heute immer mehr zu einer interdisziplinären Wissenschaft entwickelt, die die mechanischen Eigenschaften von Materialien charakterisiert.

  18. Wernher von Braun

    NASA Image and Video Library

    1959-01-01

    This photograph of Dr. von Braun, shown here to the left of General Bruce Medaris, was taken in the fall of 1959, immediately prior to Medaris' retirement from the Army. At the time, von Braun and his associates worked for the Army Ballistics Missile Agency in Huntsville, Alabama. Those in the photograph have been identified as Ernst Stuhlinger, Frederick von Saurma, Fritz Mueller, Hermarn Weidner, E.W. Neubert (partially hidden), W.A. Mrazek, Karl Heimburg, Arthur Rudolph, Otto Hoberg, von Braun, Oswald Lange, Medaris, Helmut Hoelzer, Hans Maus, E.D. Geissler, Hans Heuter, and George Constan.

  19. Wernher von Braun

    NASA Image and Video Library

    1960-01-01

    Dr. Wernher von Braun served as Marshall Space Flight Center's first director from July 1, 1960 until January 27, 1970, when he was appointed NASA Deputy Associate Administrator for Plarning. Following World War II, Dr. von Braun and his German colleagues arrived in the United States under Project Paperclip to continue their rocket development work. In 1950, von Braun and his rocket team were transferred from Ft. Bliss, Texas to Huntsville, Alabama to work for the Army's rocket program at Redstone Arsenal and later, NASA's Marshall Space Flight Center. Under von Braun's leadership, Marshall developed the Saturn V launch vehicle which took Apollo astronauts to the moon.

  20. Living with von Willebrand Disease

    MedlinePlus

    ... from the NHLBI on Twitter. Living With von Willebrand Disease If you have von Willebrand disease (VWD), you ... that they get tested too. Pregnancy and von Willebrand Disease Pregnancy can be a challenge for women who ...

  1. Wernher von Braun

    NASA Image and Video Library

    1959-01-01

    Five of the seven original astronauts are seen with Dr. von Braun inspecting the Mercury-Redstone hardware in the Fabrication Laboratory of Army Ballistic Missile Agency (ABMA) in 1959. Left to right: Astronauts Walter Schirra, Alan Shepard, John Glenn, Scott Carpenter, Gordon Cooper, and Dr. von Braun.

  2. Wernher von Braun

    NASA Image and Video Library

    1963-03-01

    This is a portrait of Maria von Braun, wife of the famous Marshall Space Flight Center (MSFC) director Wernher von Braun. Her husband, Wernher, who led America to the Moon, served as MSFC’s first director from July 1, 1960 until January 27, 1970.

  3. Wernher von Braun

    NASA Image and Video Library

    1967-11-14

    Astronaut L. Gordon Cooper checks the neck ring of a space suit worn by Marshall Space Flight Center (MSFC) Director, Dr. von Braun before he submerges into the water of the MSFC Neutral Buoyancy Simulator (NBS). Wearing a pressurized suit and weighted to a neutrally buoyant condition, Dr. von Braun was able to perform tasks underwater which simulated weightless conditions found in space.

  4. Wernher von Braun

    NASA Image and Video Library

    1967-11-14

    Marshall Space Flight Center (MSFC) Director, Dr. von Braun, submerges after spending some time under water in the MSFC Neutral Buoyancy Simulator (NBS). Weighted to a neutrally buoyant condition, Dr. von Braun was able to perform tasks underwater which simulated weightless conditions found in space.

  5. Wernher von Braun

    NASA Image and Video Library

    1967-11-14

    Marshall Space Flight Center (MSFC) Director, Dr. von Braun, is shown leaving the suiting-up van wearing a pressure suit prepared for a tryout in the MSFC Neutral Buoyancy Simulator (NBS). Weighted to a neutrally buoyant condition, Dr. von Braun was able to perform tasks underwater which simulated weightless conditions found in space.

  6. Wernher von Braun

    NASA Image and Video Library

    1967-11-14

    Marshall Space Flight Center (MSFC) Director, Dr. von Braun, is shown fitted with suit and diving equipment as he prepares for a tryout in the MSFC Neutral Buoyancy Simulator (NBS). Weighted to a neutrally buoyant condition, Dr. von Braun was able to perform tasks underwater which simulated weightless conditions found in space.

  7. Wernher von Braun

    NASA Image and Video Library

    1968-01-22

    Dr. Wernher Von Braun, stands in front of a Saturn IB Launch Vehicle at Kennedy Space Center (KSC). Dr. Von Braun was Marshall's first Center Director (1960-1970). Under his leadership Marshall was responsible for the development of the Saturn rockets, the Skylab project and getting the United States into Space and landing on the moon with the Apollo missions.

  8. Wernher von Braun

    NASA Image and Video Library

    1970-02-24

    Dr. von Braun was noted for his public speeches and presentations. In this photograph, Dr. von Braun gave a speech during a series of events to honor him prior to his relocation to Washington where he was assigned to his new duty as NASA's Deputy Associate Administrator for Plarning at NASA Headquarters.

  9. Dr. Wernher Von Braun

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Dr. Wernher Von Braun (left) and Fred W. Kelley examine a ST-100 Stellar Instrument Platform in the astrionics lab. Dr. Von Braun, then deputy associate administrator for planning, NASA, was visiting on the anniversary of the establishment of the Marshall Space Flight Center.

  10. Wernher von Braun

    NASA Image and Video Library

    2004-04-15

    Dr. von Braun is looking out from a 10th floor window of building 4200 at the Marshall Space Flight Center (MSFC). He was the first Center Director and served as the Director from July 1960 through February 1970. Following World War II, Dr. von Braun and his German colleagues arrived in the United States under the Project Paperclip (American acquisition of German rocket experts) to continue their rocket development work. In 1950, von Braun and his German Rocket Team (also called the Peenemuende Team) were transferred from Ft. Bliss, Texas to Huntsville, Alabama to work for the Army's rocket program at Redstone Arsenal and later, NASA's Marshall Space Flight Center (MSFC). Under Dr. von Braun's leadership, MSFC developed the Saturn V launch vehicle, which placed the first men, two American astronauts, on the Moon. Wernher von Braun's life was dedicated to expanding man's knowledge through the exploration of space.

  11. Dr. Wernher von Braun

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Dr. von Braun is looking out from a 10th floor window of building 4200 at the Marshall Space Flight Center (MSFC). He was the first Center Director and served as the Director from July 1960 through February 1970. Following World War II, Dr. von Braun and his German colleagues arrived in the United States under the Project Paperclip (American acquisition of German rocket experts) to continue their rocket development work. In 1950, von Braun and his German Rocket Team (also called the Peenemuende Team) were transferred from Ft. Bliss, Texas to Huntsville, Alabama to work for the Army's rocket program at Redstone Arsenal and later, NASA's Marshall Space Flight Center (MSFC). Under Dr. von Braun's leadership, MSFC developed the Saturn V launch vehicle, which placed the first men, two American astronauts, on the Moon. Wernher von Braun's life was dedicated to expanding man's knowledge through the exploration of space.

  12. Dr. Wernher von Braun

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Dr. von Braun is looking out from a 10th floor window of building 4200 at the Marshall Space Flight Center (MSFC). He was the first Center Director and served as the Director from July 1960 through February 1970. Following World War II, Dr. von Braun and his German colleagues arrived in the United States under the Project Paperclip (American acquisition of German rocket experts) to continue their rocket development work. In 1950, von Braun and his German Rocket Team (also called the Peenemuende Team) were transferred from Ft. Bliss, Texas to Huntsville, Alabama to work for the Army's rocket program at Redstone Arsenal and later, NASA's Marshall Space Flight Center (MSFC). Under Dr. von Braun's leadership, MSFC developed the Saturn V launch vehicle, which placed the first men, two American astronauts, on the Moon. Wernher von Braun's life was dedicated to expanding man's knowledge through the exploration of space.

  13. Wernher von Braun

    NASA Image and Video Library

    1977-06-16

    Dr. Wernher von Braun served as Marshall Space Flight Center's first director from July 1, 1960 until January 27, 1970, when he was appointed NASA Deputy Associate Administrator for Planning. Following World War II, Dr. von Braun and his German colleagues arrived in the United States under Project Paper Clip to continue their rocket development work. In 1950, von Braun and his rocket team were transferred from Ft. Bliss, Texas to Huntsville, Alabama to work for the Army's rocket program at Redstone Arsenal and later, NASA's Marshall Space Flight Center. Under von Braun's leadership, Marshall developed the Saturn V launch vehicle which took Apollo astronauts to the moon. Dr. von Braun died in Alexandria, Va., on June 16, 1977, seven years after his NASA appointment. This photo was taken at the site where he was laid to rest.

  14. Quantitative Analyse von Korallengemeinschaften des Sanganeb-Atolls (mittleres Rotes Meer). I. Die Besiedlungsstruktur hydrodynamisch unterschiedlich exponierter Außen- und Innenriffe

    NASA Astrophysics Data System (ADS)

    Mergner, H.; Schuhmacher, H.

    1985-12-01

    unknown species from its central part. Only 7 cnidarian species covered large areas, forming a Xenia macrospiculata-zone in TQ I, a Lobophyllia corymbosa-zone in TQ II, a Sinularia-Dendronephthya-zone in TQ III and an Acropora-Pocillopora verrucosa-zone in TQ IV. Hydrodynamic exposition and ratio of genus abundance Acropora: Montipora are closely correlated: on the windward side (TQ IV) it is 943:4, but on the leeward side (TQ I) 18:208. Apart from the taxonomic and quantitative distribution of species and colonies, types of growth form and categories of the dead substrate are given. Since soft corals do not contribute to the reef framework, the distribution of Scleractinia and Alcyonaria indicates that at Sanganeb-Atoll reef substance is mainly generated on the windward side.

  15. von Willebrand Disease.

    PubMed

    Swami, Arjun; Kaur, Varinder

    2016-01-01

    von Willebrand disease (vWD) is the most common inherited disorder of hemostasis and comprises a spectrum of heterogeneous subtypes. Significant advances have been made in understanding von Willebrand factor ( vWF) gene mutations, resultant physiologic deficits in the vWF peptide, and their correlation to clinical presentation. Diagnostic tests for this disorder are complex, and interpretation requires a thorough understanding of the underlying pathophysiology by the practicing physician. The objective of this review is to summarize our current understanding of pathophysiology, laboratory investigations, and evolving treatment paradigm of vWD with the availability of recombinant von Willebrand factor.

  16. Von Willebrand disease

    MedlinePlus

    ... done to diagnose this disease include: Bleeding time Blood typing Factor VIII level Platelet function analysis Platelet count Ristocetin cofactor test Von Willebrand factor specific tests ... invasive procedure. Blood plasma or certain factor VIII preparations may also ...

  17. Wernher von Braun

    NASA Image and Video Library

    1959-03-03

    Dr. von Braun, Director of the Development Operations Divisons, and Dr. Debus, Director of the Missile Firing Laboratory; Army Ballistic Missile Agency (ABMA), in the blockhouse during the launch of the Pioneer IV, March 3, 1959.

  18. Wernher von Braun

    NASA Image and Video Library

    1960-11-03

    Marshall Space Flight Center’s (MSFC) Director, Dr. Wernher von Braun, is pictured here with Army Ballistic Missile Agency’s (ABMA) Commanding General, J.B. Medaris, before a display of Army missles at the ABMA test lab.

  19. Wernher von Braun

    NASA Image and Video Library

    1970-06-27

    Marshall Space Flight Center (MSFC) Director Dr. Eberhard Rees conversing with former Center Director, Dr. Wernher von Braun, who along with his wife and son, participated in MFSC's Tenth Anniversary Celebration Picnic held at the Center's picnic area.

  20. Wernher von Braun

    NASA Image and Video Library

    1959-01-01

    Marshall Space Flight Center Director Wernher von Braun presents General J.B. Medaris with a new golf bag. General Medaris, (left) was a Commander of the Army Ballistic Missile Agency (ABMA) in Redstone Arsenal, Alabama during 1955 to 1958.

  1. Wernher von Braun

    NASA Image and Video Library

    1962-09-11

    Marshall Space Flight Center Director Dr. Wernher von Braun explains a detail from a Saturn IB mockup and engine to President John F. Kennedy, Vice President Lyndon Johnson and other guests, September 11, 1962.

  2. Wernher von Braun

    NASA Image and Video Library

    1960-09-08

    President Dwight D. Eisenhower and MSFC Director Dr. Wernher von Braun share a joke as other dignitaries look on. Eisenhower was visiting Marshall to participate in the September 8, 1960 dedication ceremony.

  3. Wernher von Braun

    NASA Image and Video Library

    1962-09-11

    President John F. Kennedy, Vice President Lyndon B. Johnson and Marshall Space Flight Center Director Dr. Wernher von Braun at the Redstone Arsenal Airfield, September 11, 1962. Kennedy and Johnson visited the Marshall Center to tour national space facilities.

  4. von Willebrand Factor Test

    MedlinePlus

    ... Was this page helpful? Also known as: VWF:Ag; VWF:RCo; von Willebrand Panel; Ristocetin Cofactor Formal ... may include: Ratio of VWF:RCo to VWF:Ag Factor VIII binding assay Platelet VWF studies Collagen ...

  5. Wernher von Braun

    NASA Image and Video Library

    1967-08-28

    Marshall Space Flight Center’s (MSFC) director, Dr. Wernher von Braun (right), inspects a component of a laser experiment being conducted in MSFC’s Space Sciences Laboratory during a tour on August 28, 1967.

  6. Wernher von Braun

    NASA Image and Video Library

    1969-06-04

    In this photograph, Guenter Ogger of Capitol Magazine, West Germany, greets Marshall Space Flight Center Director, Dr. Wernher von Braun. Mr. Ogger interviewed the famous rocket scientist for his magazine.

  7. Wernher von Braun

    NASA Image and Video Library

    1962-01-01

    Dr. Wernher von Braun, Director of the Marshall Space Flight Center (MSFC), during his tour of the Space information Division of North American Aviation (NAA) in Downey, California, where the Saturn SII stage was developed.

  8. Wernher von Braun

    NASA Image and Video Library

    1967-10-17

    Dr. von Braun, Director of the Marshall Space Flight Center, listens attentively to a briefing on the metal forming techniques by Dr. Mathias Siebel of the Manufacturing and Engineering Laboratory at MSFC on October 17, 1967.

  9. Wernher von Braun

    NASA Image and Video Library

    1965-11-05

    In this photograph, Marshall Space Flight Center Director, Dr. Wernher von Braun, presents a Co-Inventor’s award to MSFC employee Martin Hall of the Mechanical Engineering Laboratory during the NASA Anniversary ceremony.

  10. Wernher von Braun

    NASA Image and Video Library

    1961-10-01

    Dr. Wernher von Braun, Director of Marshall Space Flight Center (MSFC), teams up with Senator Robert S. Kerr, a chairman of the Senate Committee on Aeronautical and Space Sciences to break ground for MSFC's new Central Laboratory and Office Facility.

  11. Wernher von Braun

    NASA Image and Video Library

    1964-10-14

    This photograph, dated October 14, 1964, was taken at the Marned Spacecraft Center, now the Johnson Space Center in Houston, Texas. Dr. von Braun is shown looking over consoles in the Manned Spaceflight Control Center.

  12. Wernher von Braun

    NASA Image and Video Library

    1964-10-14

    This is a photograph that was made on October 14, 1964 of Dr. von Braun while he toured the Marned Spacecraft Center, now the Johnson Space Center in Houston, Texas. He is shown inspecting a Gemini-Agena Docking Simulator.

  13. Wernher von Braun

    NASA Image and Video Library

    1961-01-01

    Dr. von Braun is shown in this photograph, which was probably taken in the early 1960s, with members of his management team. Pictured from left to right are, Werner Kuers, Director of the Manufacturing Engineering Division; Dr. Walter Haeussermarn, Director of the Astrionics Division; Dr. William Mrazek, Propulsion and Vehicle Engineering Division; Dr. von Braun; Dieter Grau, Director of the Quality Assurance Division; Dr. Oswald Lange, Director of the Saturn Systems Office; and Erich Neubert , Associate Deputy Director for Research and Development.

  14. Wernher von Braun

    NASA Image and Video Library

    1970-02-24

    Dr. von Braun was honored with a series of farewell events and ceremonies prior to his reassignment to NASA Headquarters in Washington, D.C. Alabama Governor Brewer greets Dr. von Braun following his speech at the front of the Madison County Courthouse in Huntsville, Alabama on February 24, 1970. Behind are Madison County Commissioner James Record, Huntsville Mayor Joe Davis, and U.S. Senator Sparkman.

  15. Dr. Wernher Von Braun

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Dr. Wernher Von Braun (right), Deputy Associate Administrator for planning, National Aeronautics and Space Administration, inspects the mockup of the Saturn Workshop during a visit marking the 10th anniversary of the Marshall Center. Shown with Dr. Von Braun, from left to right, are Karl Heimburg, Director of the astronautics lab; Herman K. Weidner, Director of Science and Engineering, and George Hardy of the Astronautics lab.

  16. Dr. Wernher Von Braun

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Dr. Wernher Von Braun (right), Deputy Associate Administrator for Planning, National Aeronautics and Space Administration, inspects the mockup of the Saturn Workshop during a visit marking the 10th anniversary of the Marshall Center. Shown with Dr. Von Braun, from left to right, are Karl Heimburg, Director of the Astronautics Lab; Herman K. Weidner, Director of Science and Engineering, and George Hardy of the Astronautics Lab.

  17. Wernher von Braun

    NASA Image and Video Library

    1964-03-24

    Marshall Space Flight Center Director Dr. Wernher von Braun presents Lady Bird Johnson with an inscribed hard hat during the First Lady's March 24, 1964 visit. While at the Marshall Center, Mrs. Johnson addressed Center employees, toured facilities and witnessed test firings of a Saturn I first stage and an F-1 engine. Dr. von Braun is wearing a Texas hat presented to him months earlier by Lyndon Johnson during a visit to the Johnson ranch in Texas.

  18. Wernher von Braun

    NASA Image and Video Library

    1930-01-01

    Dr. von Braun was among a famous group of rocket experimenters in Germany in the 1930s. This photograph is believed to be made on the occasion of Herman Oberth's Kegelduese liquid rocket engine being certified as to performance during firing. From left to right are R. Nebel, Dr. Ritter, Mr. Baermueller, Kurt Heinish, Herman Oberth, Klaus Riedel, Wernher von Braun, and an unidentified person.

  19. Gastrointestinal angiodysplasia and bleeding in von Willebrand disease.

    PubMed

    Franchini, M; Mannucci, P M

    2014-09-02

    Von Willebrand disease (VWD), the most common genetic bleeding disorder, is characterised by a quantitative or qualitative defect of von Willebrand factor (VWF). Patients with VWD suffer from mucocutaneous bleeding, of severity usually proportional to the degree of VWF defect. In particular, gastrointestinal bleeding associated with angiodysplasia is often a severe symptom of difficult management. This review focuses on the pathophysiology, diagnosis and treatment of VWD-associated gastrointestinal angiodysplasia and related bleeding.

  20. Wernher von Braun

    NASA Image and Video Library

    1958-01-31

    Jet Propulsion Laboratory Director Dr. James Pickering, Dr. James van Allen of the State University of Iowa, and Army Ballistic missionile Agency Technical Director Dr. Wernher von Braun triumphantly display a model of the Explorer I, America's first satellite, shortly after the satellite's launch on January 31, 1958. The Jet Propulsion Laboratory packed and tested the payload, a radiation detection experiment designed by Dr. van Allen. Dr. von Braun's rocket team at Redstone Arsenal in Huntsville, Alabama, developed the Juno I launch vehicle, a modified Jupiter-C.

  1. Wernher von Braun

    NASA Image and Video Library

    1969-02-28

    Marshall Space Flight Center’s (MSFC) Dr. Ernst Stuhlinger, Director of Research Projects Office; and Dr. Wernher von Braun, center director, along with others, took a swim in the Neutral Buoyancy Simulator (NBS) at MSFC. A safety diver adjusts scuba equipment worn by von Braun, while Stuhlinger adjusts his weight belt prior to entering the tank. In the NBS, subjects were weighted to a neutrally buoyant condition underwater to perform and practice tasks in a simulated weightless condition as would be encountered in space.

  2. Wernher von Braun

    NASA Image and Video Library

    1950-01-01

    Dr. von Braun stands beside a model of the upper stage (Earth-returnable stage) of the three-stage launch vehicle built for the series of the motion picture productions of space flight produced by Walt Disney in the mid-1950's.

  3. Wernher von Braun

    NASA Image and Video Library

    1960-01-01

    This is a photograph of Dr. von Braun in front of a Saturn rocket hardware transporter. He appears to be addressing a group. Behind him are workers and other NASA officials. There is no date on the photograph. It may have been taken in the late 1960s.

  4. Wernher von Braun

    NASA Image and Video Library

    1959-03-04

    Dr. Wernher von Braun, Director of the U.S. Army Ballistic Missile Agency's (ABMA) Development Operations Division, talks to Huntsville Mayor R. B. "Speck" Searcy, center, and Army Ordnance Missile Command (ARMC) Major General John B. Medaris, right, during "Moon Day" celebrations in downtown Huntsville, Alabama. (Courtesy of Huntsville/Madison County Public Library)

  5. Wernher von Braun

    NASA Image and Video Library

    1959-01-01

    In this picture, Dr. Wernher von Braun, who was serving as Director of the Army Ballistic Missile Agency's (ABMA) Development Operations Division, is shown posed with his Mercedes 220SE automobile in front of Redstone Building 4488, which houses the ABMA.

  6. Dr. Wernher Von Braun

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Shown viewing the Apollo telescope mockup are, from left to right, Charles Donlan, deputy associate administrator for manned space flight; Dr. Wernher Von Braun, Marshall Space Flight Center director; William Horton, astrionics lab; Dr. Thomas Paine, NASA deputy administrator; Warner Kuers, director of the ME lab.

  7. Wernher von Braun

    NASA Image and Video Library

    1961-01-01

    During his tenure as Director of the Marshall Space Flight Center (MSFC), Dr. von Braun enjoyed personally touring the Center's many space-related laboratories and facilities. This photo taken about 1961 shows him examining a test set up in the Center's Manufacturing Engineering Laboratory.

  8. Wernher von Braun

    NASA Image and Video Library

    1962-04-16

    Dr. von Braun (right) and Astronaut John Glenn examine a model of a lunar landing stage during a talk on the manned lunar exploration program by about sixty key officials of the nation's space program at the Marshall Space Flight Center (MSFC).

  9. Wernher von Braun

    NASA Image and Video Library

    1961-01-01

    Dr. von Braun tried out a floating platform in the Marshall Space Flight Center Manufacturing Engineering Laboratory. This was a test rig to help determine how future astronauts will be able to perform maintenance tasks in the weightlessness in space. This photograph is believed to have been taken in 1961.

  10. Wernher von Braun

    NASA Image and Video Library

    1954-07-01

    Dr. Wernher von Braun (center), then Chief of the Guided Missile Development Division at Redstone Arsenal, Alabama, discusses a "bottle suit" model with Dr. Heinz Haber (left), an expert on aviation medicine, and Willey Ley, a science writer on rocketry and space exploration. The three men were at the Disney studios appearing in the motion picture, entitled "Man in Space."

  11. Wernher von Braun

    NASA Image and Video Library

    1971-01-31

    Dr. Wernher von Braun, NASA Deputy Associate Administrator for Future Programs, uses binoculars to monitor data on the closed-circuit TV screen in the Firing Room of the Launch Control Center at Kennedy Space Center (KSC) during the final preparation for the Apollo 14 launch.

  12. Wernher von Braun

    NASA Image and Video Library

    1969-02-28

    Dr. E. Stuhlinger, Dr. W. von Braun, and Dr. J. Piccard, along with others, take a swim in the Neutral Buoyancy Simulator (NBS) at the Marshall Space Flight Center. The NBS was instrumental in providing a zero-gravity environment where astronauts could practice tasks assigned for up coming space flights.

  13. Dr. Wernher Von Braun

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Shown viewing the Apollo telescope mockup are, from left to right, Charles Donlan, deputy associate administrator for manned space flight; Dr. Wernher Von Braun, Marshall Space Flight Center director; William Horton, astrionics lab; Dr. Thomas Paine, NASA deputy administrator; Warner Kuers, director of the ME lab.

  14. Dr. Wernher Von Braun

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Marshall Space Flight Center director Wernher Von Braun and his family were honored with a series of events prior to his relocation to Washington, D.C. where he was assigned duties at NASA headquarters as deputy associate administrator for planning. Here he is shown with General Richard Drury and Hazel Toftoy, widow of General H.N. Toftoy.

  15. Dr. Wernher Von Braun

    NASA Technical Reports Server (NTRS)

    1999-01-01

    A camerman catches Dr. Wernher Von Braun, Director of the Marshall Space Flight Center, his son, Peter, and daughter, Martgrit, as they arrive at the employee picnic held to celebrate man's first landing on the moon 6 days earlier. In the foreground is David R. Newby, Director of Administration and Technical Services at the Marshall Space Flight Center.

  16. Wernher von Braun

    NASA Image and Video Library

    1961-03-01

    Dr. von Braun, Director of the Marshall Space Flight Center, spoke of the progress in the Saturn Program during his appearance before the Senate Committee on Aeronautical and Space Sciences. He was accompanied by Dr. Robert C. Seamans, Jr., Associate Administrator of the National Aeronautics and Space Administration (NASA).

  17. Wernher von Braun

    NASA Image and Video Library

    1965-04-13

    Walt Disney toured the West Test Area during his visit to the Marshall Space Flight Center on April 13, 1965. The three in center foreground are Karl Heimburg, Director, Test Division; Dr. von Braun, Director, MSFC; and Walt Disney. The Dynamic Test Stand with the S-1C stage being installed is in the background.

  18. Energetische Verwertung von Biomasse

    NASA Astrophysics Data System (ADS)

    Zahoransky, Richard; Allelein, Hans-Josef; Bollin, Elmar; Oehler, Helmut; Schelling, Udo

    Etwa 0,1% der Solarenergie wandeln sich durch Photosynthese aus dem Kohlendioxid der Luft in Biomasse um. Die Biomassen sind als Festbrennstoff nutzbar oder zu gasförmigen Brennstoffen weiterverarbeitbar. Zwei Arten von Biomassen sind zu unterscheiden: Anfallende Biomasse

  19. Dr. Wernher Von Braun

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Marshall Space Flight Center director Wernher Von Braun and his family were honored with a series of events prior to his relocation to Washington, D.C. where he was assigned duties at NASA headquarters as deputy associate administrator for planning. Here he is shown with General Richard Drury and Hazel Toftoy, widow of General H.N. Toftoy.

  20. [Type 2N von Willebrand disease (Normandy)].

    PubMed

    Monpoux, F; Brunet, P; Fischer, F; Appert-Flory, A

    2011-01-01

    Willebrand disease is the most common constitutional abnormality of hemostasis. It reflects a qualitative or quantitative abnormality of von Willebrand factor (vWF) responsible for hemorrhagic syndrome, mainly mucosal, of variable expression. Type 2N (Normandy) is a rare form of von Willebrand disease due to a qualitative abnormality of vWF that disrupts its ability to bind to factor VIII. The disease biologically combines APTT prolongation, a lower level of factor VIII, and a normal or subnormal rate of vWF, which may suggest a mild form of hemophilia A. This confusion can lead not only to a misdiagnosis but also to inappropriate treatment. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

  1. Evolutionäre Algorithmen zur Topologieentwicklung von Neuronalen Netzen für die Roboter-Navigation im praktischen Einsatz

    NASA Astrophysics Data System (ADS)

    Köpsel, T.; Noglik, A.; Pauli, J.

    Eine wichtige Frage in der mobilen Robotik ist die sichere Navigation in unbekannten Umgebungen unter der Anwendung preiswerter Sensorik. Solch eine Navigation kann ein künstliches Neuronales Netz (kNN) übernehmen, welches die Kopplung der Sensoren des Roboters mit dessen Antriebssystem herstellt. "Neuro Evolution of Augmenting Topologies“ (NEAT) von Stanley und Miikkulainen [1] verwendet den Evolutionären Ansatz sowohl für die Topologieentwicklung, als auch für die Bestimmung der Gewichte eines kNN. NEAT hat sich als sehr gut, anpassungsfähig und relativ einfach in der Anwendung gezeigt. In diesem Beitrag wird NEAT in der Simulation angewendet, um ein kNN, das die Navigation des Roboters übernimmt, zu erhalten. Der Fokus liegt dabei auf der Erstellung der Fitnessfunktion und die Spezifikation und Durchführung einer realitätstreuen Simulation für den praktischen Einsatz. Die enge Verknüpfung von Realität und Simulationswelt hat entscheidend dazu beigetragen, dass der Umstieg aus der Simulation in die reale Welt ein Erfolg (höhere Anpassungsfähigkeit) wird. Dieser Artikel basiert auf der Diplomarbeit von [2].

  2. Principles of care for the diagnosis and treatment of von Willebrand disease.

    PubMed

    Castaman, Giancarlo; Goodeve, Anne; Eikenboom, Jeroen

    2013-05-01

    Von Willebrand disease is a common autosomal inherited bleeding disorder caused by quantitative or qualitative defects of von Willebrand factor, a multi-adhesive protein that binds platelets to exposed subendothelium and carries factor VIII in circulation. As a result of von Willebrand factor deficiency or abnormality, levels of factor VIII, the protein deficient in hemophilia A, may be variably reduced. Clinical manifestations are mainly represented by mucous membrane and of soft tissue bleeding. Their severity is variable depending on the degree of von Willebrand factor and factor VIII reduction. While a clear-cut diagnosis is easy in severe von Willebrand factor reductions, the advantage of pursuing a definite diagnosis in mild or dubious cases should be weighed against the risk of over-medicalization. The aim of treatment is to correct the dual defect of hemostasis caused by the abnormal/reduced von Willebrand factor and the concomitant deficiency of factor VIII. Desmopressin is the treatment of choice for type 1 von Willebrand disease patients with factor VIII and von Willebrand factor levels of 10 U/dL or over who have proved responsive to a test-infusion with the compound. Von Willebrand factor/factor VIII concentrates are needed when desmopressin is ineffective (mainly type 2 and 3 von Willebrand disease).

  3. Principles of care for the diagnosis and treatment of von Willebrand disease

    PubMed Central

    Castaman, Giancarlo; Goodeve, Anne; Eikenboom, Jeroen

    2013-01-01

    Von Willebrand disease is a common autosomal inherited bleeding disorder caused by quantitative or qualitative defects of von Willebrand factor, a multi-adhesive protein that binds platelets to exposed subendothelium and carries factor VIII in circulation. As a result of von Willebrand factor deficiency or abnormality, levels of factor VIII, the protein deficient in hemophilia A, may be variably reduced. Clinical manifestations are mainly represented by mucous membrane and of soft tissue bleeding. Their severity is variable depending on the degree of von Willebrand factor and factor VIII reduction. While a clear-cut diagnosis is easy in severe von Willebrand factor reductions, the advantage of pursuing a definite diagnosis in mild or dubious cases should be weighed against the risk of over-medicalization. The aim of treatment is to correct the dual defect of hemostasis caused by the abnormal/reduced von Willebrand factor and the concomitant deficiency of factor VIII. Desmopressin is the treatment of choice for type 1 von Willebrand disease patients with factor VIII and von Willebrand factor levels of 10 U/dL or over who have proved responsive to a test-infusion with the compound. Von Willebrand factor/factor VIII concentrates are needed when desmopressin is ineffective (mainly type 2 and 3 von Willebrand disease). PMID:23633542

  4. Wernher von Braun

    NASA Image and Video Library

    1960-01-01

    Edward O. Buckbee, the first Director of the Alabama Space Science Center (left), and Dr. Wernher von Braun (right) view a demonstration of a simulated spacecraft which uses an actual hybrid rocket engine for liftoff, hover, and landing. The display was presented to the Alabama Space Science Center, later renamed the U.S. Space and Rocket Center, by United Technology Center, a division of United Aircraft.

  5. Wernher von Braun

    NASA Image and Video Library

    1967-10-01

    Dr. von Braun encouraged his laboratory directors and other managers at the Marshall Space Flight Center (MSFC) to adopt a "hands-on" approach to managing the technical challenges they confronted in developing the Saturn rockets for the Marned Lunar Landing Program. He is shown here asking a question about welding in an MSFC manufacturing and engineering laboratory. This photograph was made on or about October 17, 1967.

  6. Wernher von Braun

    NASA Image and Video Library

    1963-03-28

    Dr. von Braun, Director of the Marshall Space Flight Center (MSFC), and Dr. Debus, Director of the Launch Operations Center, at Complex 34 prior to the Launch of the SA-4 (the fourth flight of Saturn I), March 28, 1963. The mission conducted the second "Project Highwater" experiment, which the upper stage ejected 30,000 gallons of ballast water in the upper atmosphere for a physics experiment.

  7. Wernher von Braun

    NASA Image and Video Library

    1966-06-21

    Dr. Joseph Randall, a laser expert at Marshall Space Flight Center (MSFC), explains one of the projects he is working on to a group composed of Federal Republic of Germany and MSFC officials. From left are: Dr. Randall; Minister for Scientific Research of Federal Republic of Germany, Dr. Gerhard Stolenberg; Director of MSFC Astrionics Lab, Dr. Walter Haeusserman; Head of Space Research Federal Republic of Germany, Max Mayer; MSFC Director Dr. von Braun; MSFC Deputy Director Dr. Elberhard Rees.

  8. Wernher von Braun

    NASA Image and Video Library

    1968-10-01

    Dr. von Braun inside the KC-135 in flight. The KC-135 provide NASA's Reduced-Gravity Program the unique weightlessness or zero-g environment of space flight for testing and training of human and hardware reactions. The recent version, KC-135A, is a specially modified turbojet transport which flies parabolic arcs to produce weightlessness periods of 20 to 25 seconds and its cargo bay test area is approximately 60 feet long, 10 feet wide, and 7 feet high.

  9. Wernher von Braun

    NASA Image and Video Library

    1960-01-01

    In this photo, Director of the US Army Ballistic Missile Agency (ABMA) Development Operations Division, Dr. Wernher von Braun, is standing before a display of Army missiles celebrating ABMA's Fourth Open House. The missiles in the background include (left to right) a satellite on a Juno II shroud with a Nike Ajax pointing left in front of a Jupiter missile. The Lacrosse is in front of the Juno II. The Nike Hercules points skyward in front of the Juno II and the Redstone.

  10. Missbrauchspotential von Verzeichnisdienst-Metadaten in LDAP-basierten System- und Benutzerverwaltungen

    NASA Astrophysics Data System (ADS)

    Pluta, Daniel

    Metadaten stellen Zusatzinformationen über elektronisch gespeicherte Kerninformationen zur Verfügung. Sie ergänzen die eigentliche Hauptinformation um nützliche Details. In vielen Bereichen werden Metadaten gespeichert und stehen zur Auswertung zur Verfügung. Alle IT-nahen Systeme, angefangen im Konsumerbereich (z.B. digitale Kameras) bis hin zu unternehmenskritischen Applikationen führen im Hintergrund Metadaten - parallel zu den eigentlichen Hauptdaten. Metadaten im Allgemeinen sind per se als neutral, d.h. weder positiv noch negativ, zu bewerten. So wirken sich diese häufig positiv auf das Finden und Sortieren von digitalen Dokumenten aus. Negativ treten Metadaten eigentlich immer nur dann in Erscheinung, sobald diese ursprünglich zusätzlichen und nützlichen (und daher im Gegensatz zu den Hauptdaten nicht besonders beachteten bzw. geschützten) Informationen entgegen ihrer Bestimmung, zweckentfremdet werden. Auch Verzeichnisdienste verfügen über solche nützlichen Metadaten zu den jeweils in ihnen gespeicherten Inhalten. Ob, und wenn ja wie weit diese nützlichen Inhalte auch ein Risiko darstellen können wird im Rahmen dieses Artikels anhand eines konkreten Szenarios aus dem Umfeld des Systemmanagements gezeigt.

  11. Dr. Wernher Von Braun

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Dr. Thomas Paine, Deputy Administrator of the National Aeronautics and Space Administration, examines an ordinary man's shoe outfitted for use in the Saturn I workshop. Pictured from the left in the Saturn I workshop mockup are William Brooksbank, propulsion and vehicle engineering laboratory; Dr. Paine; Dr. Wernher Von Braun, Marshall Center director; Colonel Clare F. Farley, Executive Officer in the Office Of The Administrator; and Charles J. Donlan, Deputy Associate Administrator for Manned Space Flight, Technical. the shoe Dr. Paine is holding has a unique fastener built into the sole to allow an astronaut to move about on the workshop floor and to remain in one position if he desires.

  12. Von Karman swirling flows

    NASA Astrophysics Data System (ADS)

    Zandbergen, P. J.; Dijkstra, D.

    A development history is presented for research on the problem of swirling flow infinite disks from its formulation by von Karman in 1921 through the treatments of Batchelor (1951) and Stewartson (1953) to the present, with a view to both its one-disk and two-disk forms. Attention is given to the stability of the stationary solutions for these problems, and to the case where the radii of the disks are finite. The question as to the extent to which the Karman swirling flow occurs in a finite radial geometry is noted to be of fundamental importance.

  13. Wernher von Braun

    NASA Image and Video Library

    1959-03-01

    In this photo, Director of the U.S. Army Ballistic Missile Agency's (ABMA) Development Operations Division, Dr. Wernher von Braun, and Director of Missile Firing Division, Dr. Kurt Debus, are shown with unidentified individuals, discussing two components that would make up the Pioneer IV Lunar Probe. The mercury batteries (left) were used to power the radio transmitter, cosmic radiation counter and other instruments in Pioneer IV. The conical shroud placed over the instruments of Pioneer IV was plated with gold to improve conductivity. The metal surface also served as the anterna for the probe's instruments signaling back to the Earth receiving stations.

  14. von Willebrand Disease (For Parents)

    MedlinePlus

    ... problems because the levels or functioning of these blood components needed for clotting are abnormal. continue Types of von Willebrand Disease As with many conditions, there are various forms ... of von Willebrand factor in the blood is reduced; the level of factor VIII also ...

  15. John von Neumann Birthday Centennial

    SciTech Connect

    Grcar, Joseph F.

    2004-11-12

    In celebration of John von Neumann's 100th birthday, a series of four lectures were presented on the evening of February 10, 2003 during the SIAM Conference on Computational Science and Engineering in San Diego. The venue was appropriate because von Neumann spent much of the later part of his life, in the 1950's, as an unofficial ambassador for computational science. He was then the only senior American scientist who had experience with the new computers (digital, electronic, and programmable) and a vision of their future importance. No doubt he would have relished the chance to attend a meeting such as this. The first speaker, William Aspray, described the ''interesting times'' during which computers were invented. His remarks were based on his history [1] of this period in von Neumann's life. We were honored to have John von Neumann's daughter, Marina von Neumann-Whitman, as our second speaker. Other accounts of von Neumann's life can be found in books by two of his colleagues [2] and [3]. Our third speaker, Peter Lax, provided both mathematical and international perspectives on John von Neumann's career. Finally, Pete Stewart spoke about von Neumann's numerical error analysis [4] in the context of later work; this talk did not lend itself to transcription, but readers may consult the historical notes in [5]. Our thanks to all the speakers for a remarkable evening. We are grateful to the DOE Applied Mathematical Sciences (AMS) program for partially supporting these lectures. Thanks are also due to SIAM and William Kolata, to our emcee, Gene Golub, to Paul Saylor for recording and editing, and to Barbara Lytle for the transcriptions. More about von Neumann's work can be learned from the recent American Mathematical Society proceedings [6].

  16. Wernher von Braun

    NASA Image and Video Library

    1960-09-08

    On September 8, 1960 President Dwight D. Eisenhower visited Huntsville, Alabama to dedicate a new NASA field center in honor of General George C. Marshall, Eisenhower's wartime colleague and the founder of the famous Marshall Plan for European recover after World War II. The new George C. Marshall Space Flight Center was placed under the control of Dr. Wernher Von Braun shown here talking with President Eisenhower. As parto f his remarks dedicating the center, President Eisenhowe refereed to General Marshall as a "man of yar, yet a builder of peace". the Marshall Center's first major assignment including building the huge Saturn V rocket that launched human beings on their first journey to the surface of the moon in 1969.

  17. von Karman Vortices

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Each of these swirling clouds is the result of a meteorological phenomenon known as a von Karman vortex. These vortices appeared over Alexander Selkirk Island in the southern Pacific Ocean. Rising precipitously from the surrounding waters, the island's highest point is nearly a mile (1.6 km) above sea level. As wind-driven clouds encounter this obstacle, they flow around it to form large, spinning eddies. This image was acquired by Landsat 7's Enhanced Thematic Mapper plus (ETM+) sensor on September 15, 1999. This is a false-color composite image made using shortwave infrared, infrared, and near-infrared wavelengths. Image provided by the USGS EROS Data Center Satellite Systems Branch.

  18. Wernher von Braun

    NASA Image and Video Library

    1971-07-26

    During the Apollo 15 launch activities in the launch control center's firing room 1 at Kennedy Space Center, Dr. Wernher von Braun, NASA's Deputy Associate Administrator for planning, takes a closer look at the launch pad through binoculars. The fifth manned lunar landing mission, Apollo 15 (SA-510), carrying a crew of three astronauts: Mission commander David R. Scott, Lunar Module pilot James B. Irwin, and Command Module pilot Alfred M. Worden Jr., lifted off on July 26, 1971. Astronauts Scott and Irwin were the first to use a wheeled surface vehicle, the Lunar Roving Vehicle, or the Rover, which was designed and developed by the Marshall Space Flight Center, and built by the Boeing Company. Astronauts spent 13 days, nearly 67 hours, on the Moon's surface to inspect a wide variety of its geological features.

  19. Dr. Wernher Von Braun

    NASA Technical Reports Server (NTRS)

    1960-01-01

    On September 8, 1960 President Dwight D. Eisenhower visited Huntsville, Alabama to dedicate a new NASA field center in honor of General George C. Marshall, Eisenhower's wartime colleague and the founder of the famous Marshall Plan for European recover after World War II. The new George C. Marshall Space Flight Center was placed under the control of Dr. Wernher Von Braun shown here talking with President Eisenhower. As parto f his remarks dedicating the center, President Eisenhowe refereed to General Marshall as a 'man of yar, yet a builder of peace'. the Marshall Center's first major assignment including building the huge Saturn V rocket that launched human beings on their first journey to the surface of the moon in 1969.

  20. Von Hippel's disease in association with von Recklinghausen's neurofibromatosis.

    PubMed Central

    Thomas, J V; Schwartz, P L; Gragoudas, E S

    1978-01-01

    Ten members of a large family who showed manifestations of either von Hippel-Lindau disease or von Recklinghausen's neurofibromatosis were examined. Three of 10 members were found to have retinal angiomas which had not been present on fundus examination 3 years previously. These angiomas were associated with ocular and systemic signs of neurofibromatosis. These cases show overlapping manifestations of different phakomatoses and provide support for the concept of a common aetiology for these diseases. Images PMID:101230

  1. von Braun and German Publisher

    NASA Technical Reports Server (NTRS)

    1969-01-01

    In this photograph, Guenter Ogger of Capitol Magazine, West Germany, greets Marshall Space Flight Center Director, Dr. Wernher von Braun. Mr. Ogger interviewed the famous rocket scientist for his magazine.

  2. Sulfation of von Willebrand factor

    SciTech Connect

    Carew, J.A.; Browning, P.J.; Lynch, D.C. )

    1990-12-15

    von Willebrand factor (vWF) is a multimeric adhesive glycoprotein essential for normal hemostasis. We have discovered that cultured human umbilical vein endothelial cells incorporate inorganic sulfate into vWF. Following immunoisolation and analysis by polyacrylamide or agarose gel electrophoresis, metabolically labeled vWF was found to have incorporated (35S)-sulfate into all secreted multimer species. The time course of incorporation shows that sulfation occurs late in the biosynthesis of vWF, near the point at which multimerization occurs. Quantitative analysis suggests the presence, on average, of one molecule of sulfate per mature vWF subunit. Virtually all the detectable sulfate is released from the mature vWF subunit by treatment with endoglycosidases that remove asparagine-linked carbohydrates. Sulfated carbohydrate was localized first to the N-terminal half of the mature subunit (amino acids 1 through 1,365) by partial proteolytic digestion with protease V8; and subsequently to a smaller fragment within this region (amino acids 273 through 511) by sequential digestions with protease V8 and trypsin. Thus, the carbohydrate at asparagine 384 and/or 468 appears to be the site of sulfate modification. Sodium chlorate, an inhibitor of adenosine triphosphate-sulfurylase, blocks sulfation of vWF without affecting either the ability of vWF to assemble into high molecular weight multimers or the ability of vWF multimers to enter Weible-Palade bodies. The stability of vWF multimers in the presence of an endothelial cell monolayer also was unaffected by the sulfation state. Additionally, we have found that the cleaved propeptide of vWF is sulfated on asparagine-linked carbohydrate.

  3. Von Karman and JATO Team

    NASA Technical Reports Server (NTRS)

    1940-01-01

    Dr. Theodore von Karman (black coat) sketches out a plan on the wing of an airplane as his JATO engineering team looks on. From left to right: Dr. Clark B. Millikan, Dr.Martin Summerfield, Dr. Theodore von Karman, Dr. Frank J. Malina and pilot, Capt. Homer Boushey. Captain Boushey would become the first American to pilot an airplane that used JATO (Jet Assisted Take-Off) solid propellent rockets.

  4. Wernher von Braun

    NASA Image and Video Library

    1969-07-01

    This photograph depicts Dr. von Braun (fourth from far right) and other NASA officials surveying the deep-sea research submarine "Ben Franklin." Named for American patriot and inventor Ben Franklin, who discovered the Gulf Steam, the 50-foot Ben Franklin was built between 1966 and 1968 in Switzerland for deep-ocean explorer Jacques Piccard and the Grumman Aircraft Engineering Corporation. The submersible made a famous 30-day drift dive off the East Coast of the United States and Canada in 1969 mapping the Gulf Stream's currents and sea life, and also made space exploration history by studying the behavior of aquanauts in a sealed, self-contained, self-sufficient capsule for NASA. On July 14, 1969, the Ben Franklin was towed to the high-velocity center of the Stream off the coast of Palm Beach, Florida. With a NASA observer on board, the sub descended to 1,000 feet off of Riviera Beach, Florida and drifted 1,400 miles north with the current for more than four weeks, reemerging near Maine. During the course of the dive, NASA conducted exhaustive analyses of virtually every aspect of onboard life. They measured sleep quality and patterns, sense of humor and behavioral shifts, physical reflexes, and the effects of a long-term routine on the crew. The submarine's record-shattering dive influenced the design of Apollo and Skylab missions and continued to guide NASA scientists as they devised future marned space-flight missions.

  5. Wernher von Braun

    NASA Image and Video Library

    1969-07-01

    This photograph depicts Dr. von Braun (at right, showing his back) and other NASA officials surveying the deep-sea research submarine "Ben Franklin." Named for American patriot and inventor Ben Franklin, who discovered the Gulf Steam, the 50-foot Ben Franklin was built between 1966 and 1968 in Switzerland for deep-ocean explorer Jacques Piccard and the Grumman Aircraft Engineering Corporation. The submersible made a famous 30-day drift dive off the East Coast of the United States and Canada in 1969 mapping the Gulf Stream's currents and sea life, and also made space exploration history by studying the behavior of aquanauts in a sealed, self-contained, self-sufficient capsule for NASA. On July 14, 1969, the Ben Franklin was towed to the high-velocity center of the Stream off the coast of Palm Beach, Florida. With a NASA observer on board, the sub descended to 1,000 feet off of Riviera Beach, Florida and drifted 1,400 miles north with the current for more than four weeks, reemerging near Maine. During the course of the dive, NASA conducted exhaustive analyses of virtually every aspect of onboard life. They measured sleep quality and patterns, sense of humor and behavioral shifts, physical reflexes, and the effects of a long-term routine on the crew. The submarine's record-shattering dive influenced the design of Apollo and Skylab missions and continued to guide NASA scientists as they devised future marned space-flight missions.

  6. Richard von Volkmann

    PubMed Central

    Willy, Christian; Schneider, Peter; Engelhardt, Michael; Hargens, Alan R.

    2008-01-01

    Richard von Volkmann (1830–1889), one of the most important surgeons of the 19th century, is regarded as one of the fathers of orthopaedic surgery. He was a contemporary of Langenbeck, Esmarch, Lister, Billroth, Kocher, and Trendelenburg. He was head of the Department of Surgery at the University of Halle, Germany (1867–1889). His popularity attracted doctors and patients from all over the world. He was the lead physician for the German military during two wars. From this experience, he compared the mortality of civilian and war injuries and investigated the general poor hygienic conditions in civilian hospitals. This led him to introduce the “antiseptic technique” to Germany that was developed by Lister. His powers of observation and creativity led him to findings and achievements that to this day bear his name: Volkmann’s contracture and the Hueter-Volkmann law. Additionally, he was a gifted writer; he published not only scientific literature but also books of children’s fairy tales and poems under the pen name of Richard Leander, assuring him a permanent place in the world of literature as well as orthopaedics. PMID:18196438

  7. Von Willebrand factor processing.

    PubMed

    Brehm, Maria A

    2017-01-31

    Von Willebrand factor (VWF) is a multimeric glycoprotein essential for primary haemostasis that is produced only in endothelial cells and megakaryocytes. Key to VWF's function in recruitment of platelets to the site of vascular injury is its multimeric structure. The individual steps of VWF multimer biosynthesis rely on distinct posttranslational modifications at specific pH conditions, which are realized by spatial separation of the involved processes to different cell organelles. Production of multimers starts with translocation and modification of the VWF prepropolypeptide in the endoplasmic reticulum to produce dimers primed for glycosylation. In the Golgi apparatus they are further processed to multimers that carry more than 300 complex glycan structures functionalized by sialylation, sulfation and blood group determinants. Of special importance is the sequential formation of disulfide bonds with different functions in structural support of VWF multimers, which are packaged, stored and further processed after secretion. Here, all these processes are being reviewed in detail including background information on the occurring biochemical reactions.

  8. On the Versatility of von Willebrand Factor

    PubMed Central

    Rauch, Antoine; Wohner, Nikolett; Christophe, Olivier D.; Denis, Cécile V.; Susen, Sophie; Lenting, Peter J.

    2013-01-01

    Von Willebrand factor (VWF) is a large multimeric protein, the function of which has been demonstrated to be pivotal to the haemostatic system. Indeed, quantitative and/or qualitative abnormalities of VWF are associated with the bleeding disorder Von Willebrand disease (VWD). Moreover, increased plasma concentrations of VWF have been linked to an increased risk for thrombotic complications. In the previous decades, many studies have contributed to our understanding of how VWF is connected to the haemostatic system, particularly with regard to structure-function relationships. Interactive sites for important ligands of VWF (such as factor VIII, collagen, glycoprotein Ibα, integrin αIIbβ3 and protease ADAMTS13) have been identified, and mutagenesis studies have confirmed the physiological relevance of the interactions between VWF and these ligands. However, we have also become aware that VWF has a more versatile character than previously thought, given its potential role in various non-hemostatic processes, like intimal thickening, tumor cell apoptosis and inflammatory processes. In the presence review, a summary of our knowledge on VWF structure-function relationships is provided in the context of the “classical” haemostatic task of VWF and in perspective of pathological processes beyond haemostasis. PMID:23936617

  9. Rethinking the diagnosis of von Willebrand disease.

    PubMed

    Favaloro, Emmanuel J

    2011-01-01

    von Willebrand disease (VWD) is the most common inherited bleeding disorder and arises from deficiencies and/or defects in the plasma protein von Willebrand factor (VWF). VWD is classified into 6 different types, with type 1 identified as a (partial) quantitative deficiency of VWF, type 3 defined by a (virtual) total deficiency of VWF, and type 2 identifying four separate types (2A, 2B, 2M, 2N) characterised by qualitative defects. The classification is based on phenotypic assays including FVIII, VWF:Ag and VWF activity, typically by ristocetin cofactor (VWF:RCo), but also increasingly by collagen binding (VWF:CB). Phenotypic testing may be supplemented by multimer analysis, RIPA, and VWF:FVIII binding. Although genetic analysis is not required to diagnose VWD or to define a classification type, it may be useful in discrete situations. The current review briefly covers this diagnostic process, with a focus on newer approaches, including extended test panels and the use of data from desmopressin challenges as a diagnostic tool. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. [Pheochromocytoma and von Recklinghausen's disease].

    PubMed

    Rabii, R; Fekak, H; Moufid, K; Joual, A; Bennani, S; el Mrini, M; Benjelloun, S

    2002-07-01

    The association between von Recklinghausen's disease and pheochromocytoma is present about 10% of cases. We report a case of 49 years old women who presented with elevated blood pressure and von Recklinghausen's neurofibromatosis. Laboratory examination showed a marked level in the urinary excretion of cathecholamine. The computed tomography showed a right adrenal tumor suggesting a pheochromocytoma. The adrenalectomy was realised by transabdominal approach and the histological examination confirmed a benign pheochromocytoma. The authors discuss the pathogenetic hypothesis of this rare pathological association, the diagnostic methods and the therapeutic procedure.

  11. Von Hippel-Lindau Disease

    MedlinePlus

    Von Hippel-Lindau disease (VHL) is a rare, genetic disease that causes tumors and cysts to grow in your body. The tumors can be either ... and, in men, their genital tract. Symptoms of VHL vary and depend on the size and location ...

  12. Eine selbstkonsistente Carleman Linearisierung zur Analyse von Oszillatoren

    NASA Astrophysics Data System (ADS)

    Weber, Harry; Mathis, Wolfgang

    2017-09-01

    Die Analyse nichtlinearer dynamischer Schaltungen ist bis heute eine herausfordernde Aufgabe, da nur selten analytische Lösungen angegeben werden können. Daher wurden eine Vielzahl von Methoden entwickelt, um eine qualitative oder quantitative Näherung für die Lösungen der Netzwerkgleichung zu erhalten. Oftmals wird beispielsweise eine Kleinsignalanalyse mit Hilfe einer Taylorreihe in einem Arbeitspunkt durchgeführt, die nach den Gliedern erster Ordnung abgebrochen wird. Allerdings ist diese Linearisierung nur in der Nähe des stabilen Arbeitspunktes für hyperbolische Systeme gültig. Besonders für die Analyse des dynamischen Verhaltens von Oszillatoren treten jedoch nicht-hyperbolische Systeme auf, sodass diese Methode nicht angewendet werden kann Mathis(2000). Carleman hat gezeigt, dass nichtlineare Differentialgleichungen mit polynomiellen Nichtlinearitäten in ein unendliches System von linearen Differentialgleichungen transformiert werden können Carleman(1932). Wird das unendlichdimensionale Gleichungssystem für numerische Zwecke abgebrochen, kann bei Oszillatoren der Übergang in eine stationäre Schwingung (Grenzzyklus) nicht wiedergegeben werden.

    In diesem Beitrag wird eine selbstkonsistente Carleman Linearisierung zur Untersuchung von Oszillatoren vorgestellt, die auch dann anwendbar ist, wenn die Nichtlinearitäten keinen Polynomen entsprechen. Anstelle einer linearen Näherung um einen Arbeitspunkt, erfolgt mit Hilfe der Carleman Linearisierung eine Approximation auf einem vorgegebenen Gebiet. Da es jedoch mit der selbstkonsistenten Technik nicht möglich ist, das stationäre Verhalten von Oszillatoren zu beschreiben, wird die Berechnung einer Poincaré-Abbildung durchgeführt. Mit dieser ist eine anschließende Analyse des Oszillators möglich.

  13. Diagnostic Value of Measuring Platelet Von Willebrand Factor in Von Willebrand Disease

    PubMed Central

    Casonato, Alessandra; Cattini, Maria Grazia; Daidone, Viviana; Pontara, Elena; Bertomoro, Antonella; Prandoni, Paolo

    2016-01-01

    Von Willebrand disease (VWD) may be caused by an impaired von Willebrand factor (VWF) synthesis, its increased clearance or abnormal function, or combinations of these factors. It may be difficult to recognize the different contributions of these anomalies. Here we demonstrate that VWD diagnostics gains from measuring platelet VWF, which can reveal a defective VWF synthesis. Measuring platelet VWF revealed that: severe type 1 VWD always coincided with significantly lower platelet and plasma VWF levels, whereas mild forms revealed low plasma VWF levels associated with low or normal platelet VWF levels, and the latter were associated with a slightly shorter VWF survival; type Vicenza (the archetype VWD caused by a reduced VWF survival) featured normal platelet VWF levels despite significantly reduced plasma VWF levels; type 2B patients could have either normal platelet VWF levels associated with abnormal multimer patterns, or reduced platelet VWF levels associated with normal multimer patterns; type 2A patients could have reduced or normal platelet VWF levels, the former associated mainly with type 2A-I, the latter with type 2A-II; plasma and platelet VWF levels were normal in type 2N, except when the defect was associated with a quantitative VWF mutation. Our findings show that measuring platelet VWF helps to characterize VWD, especially the ambiguous phenotypes, shedding light on the mechanisms underlying the disorder. PMID:27532107

  14. Recombinant von Willebrand factor: a first-of-its-kind product for von Willebrand disease.

    PubMed

    Singal, M; Kouides, P A

    2016-12-01

    von Willebrand disease (VWD) is caused by quantitative or qualitative defects in von Willebrand factor (VWF). The mainstay of therapy is desmopressin, which is, however, not useful in certain forms of VWD notwithstanding adverse events. For these patients, plasma-derived factor VIII (pdFVIII)/VWF concentrates have been available for close to three decades but have a theoretical risk of disease transmission, hypersensitivity/allergic reactions, inhibitors and thrombosis. A recombinant VWF (vonicog alfa, Vonvendi™; manufactured by Baxalta, now part of Shire) was approved by the U.S. Food and Drug Administration (FDA) in December 2015. This review will survey the literature based on a MEDLINE review on the safety, efficacy and pharmacokinetics of Vonvendi. It will also summarize the ongoing studies on Vonvendi available in the public domain. Vonvendi may have an important role in the management of VWD. However, more studies are needed, especially in special populations such as surgical patients, patients with major gastrointestinal bleeding from arteriovenous malformations and pregnant women and children, who are most likely to benefit from it.

  15. [Was Klaus von Mantrei the teacher of Hans von Gersdorff?].

    PubMed

    Vollmuth, R

    1996-01-01

    One of the most popular representatives of surgery at the end of the middle ages and the beginning modern era is the Strassburgian surgeon Hans von Gersdorff. Still we do not know very much about his life and his surgical teachers. Only one meister Nicklaus, called Mulartzt, is mentioned as such by the remarks in Gersdorffs 'Feldbuch der Wundarznei', but till today this surgeon could not be identified in more detail. This article now holds the thesis, that meister Nicklaus is probably identical with Klaus von Matrei (Metry), a well-known surgeon of the late 15th century. That cannot be fully proved yet, but a number of coinciding characteristics between the two and some further indications, that are explained, seem so significant, that the thesis can hardly be doubted.

  16. Exponential Size Distribution of von Willebrand Factor

    PubMed Central

    Lippok, Svenja; Obser, Tobias; Müller, Jochen P.; Stierle, Valentin K.; Benoit, Martin; Budde, Ulrich; Schneppenheim, Reinhard; Rädler, Joachim O.

    2013-01-01

    Von Willebrand Factor (VWF) is a multimeric protein crucial for hemostasis. Under shear flow, it acts as a mechanosensor responding with a size-dependent globule-stretch transition to increasing shear rates. Here, we quantify for the first time, to our knowledge, the size distribution of recombinant VWF and VWF-eGFP using a multilateral approach that involves quantitative gel analysis, fluorescence correlation spectroscopy, and total internal reflection fluorescence microscopy. We find an exponentially decaying size distribution of multimers for recombinant VWF as well as for VWF derived from blood samples in accordance with the notion of a step-growth polymerization process during VWF biosynthesis. The distribution is solely described by the extent of polymerization, which was found to be reduced in the case of the pathologically relevant mutant VWF-IIC. The VWF-specific protease ADAMTS13 systematically shifts the VWF size distribution toward smaller sizes. This dynamic evolution is monitored using fluorescence correlation spectroscopy and compared to a computer simulation of a random cleavage process relating ADAMTS13 concentration to the degree of VWF breakdown. Quantitative assessment of VWF size distribution in terms of an exponential might prove to be useful both as a valuable biophysical characterization and as a possible disease indicator for clinical applications. PMID:24010664

  17. Treatment of von Willebrand Disease.

    PubMed

    Curnow, Jennifer; Pasalic, Leonardo; Favaloro, Emmanuel J

    2016-03-01

    Congenital von Willebrand disease (VWD) and acquired von Willebrand syndrome (AVWS) reflect conditions caused by von Willebrand factor (VWF) deficiency and/or defects. VWD is the most common inherited bleeding disorder and AVWS arises from a variety of causes. Since VWF stabilizes and protects factor VIII (FVIII) in the circulation, this is also reduced in many patients with VWD. The treatment of VWD and AVWS therefore primarily entails replacement of VWF, and sometimes FVIII, to protect against bleeding. This may entail the use of VWF concentrates (currently plasma-derived) and/or FVIII concentrates (currently plasma-derived or more increasingly recombinant forms), and/or desmopressin to release endogenous VWF in subgroups of patients. For AVWS additional treatment of the underlying condition is also required. Adjunct therapies include antifibrinolytics. Globally, various formulations exist for both VWF and FVIII concentrates and are differentially available based on manufacturer marketing or regulatory approvals/clearances in different geographies. Also, guidelines for treatment of VWD vary for different localities and recombinant VWF is undergoing clinical trials. The current review provides an overview of the treatment of VWD as currently practiced in developed countries, and also provides a glimpse towards the future.

  18. Dr. von Braun Briefing Walt Disney

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Dr. von Braun began his association with Walt Disney in the 1950s when the rocket scientist appeared in three Disney television productions related to the exploration of space. Years later, Dr. von Braun invited Disney and his associates to tour the Marshall Space Flight Center (MSFC) in Huntsville, Alabama. This photograph is dated April 13, 1965. From left are R.J. Schwinghamer from the MSFC, Disney, B.J. Bernight, and Dr. von Braun.

  19. Dr. von Braun Briefing Walt Disney

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Dr. von Braun began his association with Walt Disney in the 1950s when the rocket scientist appeared in three Disney television productions related to the exploration of space. Years later, Dr. von Braun invited Disney and his associates to tour the Marshall Space Flight Center (MSFC) in Huntsville, Alabama. This photograph is dated April 13, 1965. From left are R.J. Schwinghamer from the MSFC, Disney, B.J. Bernight, and Dr. von Braun.

  20. Nichtlineare Rauschmodellierung von LC Tank VCOs

    NASA Astrophysics Data System (ADS)

    Thiessen, T.; Bremer, J.-K.; Mathis, W.

    2008-05-01

    Im Rahmen dieser Arbeit wird ein alternativer Ansatz zur Phasenrauschoptimierung von LC-Tank Oszillatoren (VCOs) unter Verwendung stochastischer Differentialgleichungen vorgestellt. Zunächst werden die linearen Ansätze von Leeson, Hajimiri und Lee analysiert und bewertet. Danach wird ein Konzept vorgestellt, mit dem man die Rauscheigenschaften von VCOs auf der Grundlage stochastischer Differentialgleichungen und Fokker-Planck-Gleichungen untersuchen kann. Ziel dieser Arbeit ist eine Beschreibung des Phasenrauschens auf der Basis einer nichtlinearen Rauschmodellierung, welche Parameter eines VCOs für eine Optimierung beinhaltet. Es wurde ein Matlab-Tool erstellt und die Funktionalität anhand von Simulationen verifiziert.

  1. Reflexionseigenschaften von Windenergieanlagen im Funkfeld von Funknavigations- und Radarsystemen

    NASA Astrophysics Data System (ADS)

    Sandmann, S.; Divanbeigi, S.; Garbe, H.

    2015-11-01

    Die hier behandelte Untersuchung befasst sich mit den Störungen des elektrischen Feldes einer Doppler Very High Frequency Omnidirectional Radio Range Navigationsanlage (DVOR) in der Gegenwart von Windenergieanlagen (WEA). Hierfür wird die Feldstärke auf 25 konzentrischen Kreisbahnen, sog. Orbit Flights verschiedener Höhen und mit verschiedenen Radien rund um die DVOR-Anlage numerisch simuliert. Insbesondere werden die Einflüsse diverser Parameter der WEA wie deren Anzahl, Position, Rotorwinkel, Turmhöhe und Rotordurchmesser auf die Feldverteilung herausgestellt, sowie die Anwendbarkeit der Simulationsmethode Physical Optics (PO) durch Vergleich der Simulationsergebnisse mit denen der Multi Level Fast Multipol Method (MLFMM) untersucht.

  2. Current management of von Willebrand disease and von Willebrand syndrome.

    PubMed

    Stone, Marc E; Mazzeffi, Michael; Derham, Jeffrey; Korshin, Andre

    2014-06-01

    Anesthesiologists frequently care for patients with altered hemostasis and coagulation. Where a clear history of familial and personal bleeding exists, a thoughtful plan can be developed in advance to manage the issue perioperatively. However, in some cases, it may not be known that the patient has a disorder until excessive bleeding is noted during or after surgery. Recognition of the issue and appropriate targeted therapy are the keys to successful management. With an estimated prevalence approaching 1% of the population, von Willebrand disease (vWD) is the most common hereditary bleeding diathesis, but the estimated prevalence of acquired vWD (often termed von Willebrand syndrome or vWS) is now believed to be significantly higher, especially in patients with malignancies, autoimmune diseases, cardiac valvular lesions, and in patients on mechanical circulatory support devices. Acquired vWD may also occur with certain medications. The mainstay of the diagnosis of vWD is laboratory testing. Preoperative clinical assessment and a high level of suspicion are often effective to alert the anesthesiologist to the possibility of vWS, thus allowing for appropriate testing and potential prophylaxis in elective situations, as well as appropriately targeted therapy of unexpected bleeding when a hemostatic derangement was not anticipated preoperatively.

  3. Von Karman Streets Chaotic Simulation

    NASA Astrophysics Data System (ADS)

    Skiadas, C. H.

    In this paper we model and simulate the so-called Von Karman Streets, a characteristic form of turbulent (vortex) flow that appears in small or large systems. Very interesting examples are the large turbulent formations in the sea or in the clouds that have been viewed and photographed from the space (from satellites). The modeling approach is based on the Rotation-Reflection-Translation theory developed in the recent book [1]. The related theory was already applied in various fields and especially in flows.

  4. Dr. Wernher Von Braun greeting dignitaries.

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Dr. Wernher Von Braun, left, greets vice president Spiro T. Agnew in the Launch Control Center for the Apollo 14 mission. Between Dr. Von Braun and Mr. Agnew are their Royal Highnesses, The Prince and Princess of Spain. The royal visitors greeted the launch control team in th enter after the launch of Apollo 14.

  5. Dr. Wernher Von Braun at a picnic.

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Dr. Wernher Von Braun, director of the Marshall Space Flight Center, stakes claim to a table for the picnic celebrating man's first lunar landing. With Dr. Von Braun are his wife, Maria (seated, right), and son, Peter (back to camera). His daughter, Margrit, was also present, but is hidden from view by friends in this view.

  6. Dr. Wernher Von Braun at a picnic.

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Dr. Wernher Von Braun, director of the Marshall Space Flight Center, stakes claim to a table for the picnic celebrating man's first lunar landing. With Dr. Von Braun are his wife, Maria (seated, right), and son, Peter (back to camera). His daughter, Margrit, was also present, but is hidden from view by friends in this view.

  7. Dr. von Braun Tries Out the NBS

    NASA Technical Reports Server (NTRS)

    1967-01-01

    Marshall Space Flight Center (MSFC) Director, Dr. von Braun, is shown fitted with suit and diving equipment as he prepares for a tryout in the MSFC Neutral Buoyancy Simulator (NBS). Weighted to a neutrally buoyant condition, Dr. von Braun was able to perform tasks underwater which simulated weightless conditions found in space.

  8. Walt Disney and Dr. Wernher von Braun

    NASA Technical Reports Server (NTRS)

    1954-01-01

    Dr. Werhner von Braun, then Chief, Guided Missile Development Operation Division at Army Ballistic Missile Agency (ABMA) in Redstone Arsenal, Alabama, was visited by Walt Disney in 1954. In the 1950's, von Braun worked with Disney Studio as a technical director, making three films about space exploration for television. A model of the V-2 rocket is in background.

  9. Dr. Wernher von Braun Laid to Rest

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Dr. Wernher von Braun served as Marshall Space Flight Center's first director from July 1, 1960 until January 27, 1970, when he was appointed NASA Deputy Associate Administrator for Planning. Following World War II, Dr. von Braun and his German colleagues arrived in the United States under Project Paper Clip to continue their rocket development work. In 1950, von Braun and his rocket team were transferred from Ft. Bliss, Texas to Huntsville, Alabama to work for the Army's rocket program at Redstone Arsenal and later, NASA's Marshall Space Flight Center. Under von Braun's leadership, Marshall developed the Saturn V launch vehicle which took Apollo astronauts to the moon. Dr. von Braun died in Alexandria, Va., on June 16, 1977, seven years after his NASA appointment. This photo was taken at the site where he was laid to rest.

  10. Dr. Wernher von Braun In His Office

    NASA Technical Reports Server (NTRS)

    1964-01-01

    Dr. Wernher von Braun served as Marshall Space Flight Center's first director from July 1, 1960 until January 27, 1970, when he was appointed NASA Deputy Associate Administrator for Planning. Following World War II, Dr. von Braun and his German colleagues arrived in the United States under Project Paperclip to continue their rocket development work. In 1950, von Braun and his rocket team were transferred from Ft. Bliss, Texas to Huntsville, Alabama to work for the Army's rocket program at Redstone Arsenal and later, NASA's Marshall Space Flight Center. Under von Braun's leadership, Marshall developed the Saturn V launch vehicle which took Apollo astronauts to the moon. This photo depicts von Braun in his office at MSFC.

  11. Clearance of von Willebrand factor.

    PubMed

    Denis, Cécile V; Christophe, Olivier D; Oortwijn, Beatrijs D; Lenting, Peter J

    2008-02-01

    The life cycle of von Willebrand factor (VWF) comprises a number of distinct steps, ranging from the controlled expression of the VWF gene in endothelial cells and megakaryocytes to the removal of VWF from the circulation. The various aspects of VWF clearance have been the objects of intense research in the last few years, stimulated by observations that VWF clearance is a relatively common component of the pathogenesis of type 1 von Willebrand disease (VWD). Moreover, improving the survival of VWF is now considered as a viable therapeutic strategy to prolong the half-life of factor VIII in order to optimise treatment of haemophilia A. The present review aims to provide an overview of recent findings with regard to the molecular basis of VWF clearance. A number of parameters have been identified that influence VWF clearance, including its glycosylation profile and a number of VWF missense mutations. In addition, in-vivo studies have been used to identify cells that contribute to the catabolism of VWF, providing a starting point for the identification of receptors that mediate the cellular uptake of VWF. Finally, we discuss recent data describing chemically modification of VWF as an approach to prolong the half-life of the VWF/FVIII complex.

  12. Alloantibodies in von Willebrand disease.

    PubMed

    James, Paula D; Lillicrap, David; Mannucci, Pier M

    2013-08-01

    The development of alloantibodies against von Willebrand factor (VWF) represents a rare but serious complication of treatment of von Willebrand disease (VWD), occurring in ~5% to 10% of type 3 VWD patients. Affected patients can present with a range of symptoms, including lack or loss of hemostatic response to infused VWF concentrates up to anaphylactic reactions in rare cases. It is classically reported in multitransfused patients and occurs most frequently in patients with partial or complete VWF gene deletions. A positive family history of anti-VWF antibodies also appears to be a risk factor. There is a lack of standardization of laboratory methods for antibody identification and characterization. Issues of variability in laboratory approaches as well as the rarity of the complication act as a barrier to future studies. Recombinant factor VIII as well as bypassing agents and immune tolerance have been reported as effective treatments; however, aside from case reports, little exists in the literature to guide management. The imminent clinical availability of recombinant VWF has prompted a resurgence of interest in this area. Additional study is warranted to address the deficiencies in our understanding of this treatment complication.

  13. A double commutant theorem for Murray–von Neumann algebras

    PubMed Central

    Liu, Zhe

    2012-01-01

    Murray–von Neumann algebras are algebras of operators affiliated with finite von Neumann algebras. In this article, we study commutativity and affiliation of self-adjoint operators (possibly unbounded). We show that a maximal abelian self-adjoint subalgebra of the Murray–von Neumann algebra associated with a finite von Neumann algebra is the Murray–von Neumann algebra , where is a maximal abelian self-adjoint subalgebra of and, in addition, is . We also prove that the Murray–von Neumann algebra with the center of is the center of the Murray–von Neumann algebra . Von Neumann’s celebrated double commutant theorem characterizes von Neumann algebras as those for which , where , the commutant of , is the set of bounded operators on the Hilbert space that commute with all operators in . At the end of this article, we present a double commutant theorem for Murray–von Neumann algebras. PMID:22543165

  14. Indikatorenbasierte Bewertung von Entwurfsentscheidungen auf Systemebene

    NASA Astrophysics Data System (ADS)

    Freier, M.; Wenzler, A.; Mayer, T.; Gerlach, J.; Rosenstiel, W.

    2013-07-01

    Bei dem Entwurf von anwendungsspezifischen integrierten Schaltungen muss ein Entwickler zusätzliche Funktionen integrieren und die zunehmende Komplexität bewältigen. Für die Reduzierung der Kosten bleibt weiterhin die Verkürzung der benötigten Entwicklungszeit ein Ziel. Ein entscheidender Faktor dabei ist die zuverlässige Absicherung von Entwurfsentscheidungen in einer frühen Entwurfsphase. In der vorliegenden Arbeit wird eine Methode vorgestellt, die eine Bewertung von Entwurfsentscheidungen bei Systemmodellen mittels automatisch ermittelter Indikatoren ermöglichen soll. Die Systemmodelle können mit der Entwurfsumgebung MATLAB/Simulink oder in SystemC beschrieben sein.

  15. Von Hippel-Lindau disease.

    PubMed

    Maher, Eamonn R

    2004-12-01

    Germline mutations in the VHL tumour suppressor gene may cause a variety of phenotypes including von Hippel-Lindau (VHL) disease, familial phaeochromocytoma and inherited polycythaemia. VHL disease is a multisystem familial cancer syndrome and is the commonest cause of familial renal cell carcinoma (RCC). VHL disease provides a paradigm for illustrating how studies of a rare familial cancer syndrome can produce advances in clinical medicin and important insights into basic biological processes. Thus the identification of the VHL gene has improved the diagnosis and clinical management of VHL disease and provided insights into the pathogenesis of sporadic clear cell RCC. Functional investigations of the VHL gene product have provided novel information on how cells sense oxygen and the role of hypoxia-response pathways in human tumourigenesis. Such information offers prospects of novel therapeutic interventions for VHL disease and common cancers including RCC.

  16. The Digital Von Fahrenheid Pyramid

    NASA Astrophysics Data System (ADS)

    Bura, M.; Janowski, J.; Wężyk, P.; Zięba, K.

    2017-08-01

    3D Scanners Lab from Digital Humanities Laboratory at the University of Warsaw initiated the scientific project, the purpose of which was to call attention to systematically penetrated and devastated pyramid-shaped tomb from the XVIII/XIX century, of family von Fahrenheid in Rapa in Banie Mazurskie commune (NE Poland). By conducting a series of non-invasive studies, such as 3D inventory using terrestrial laser scanning (TLS), thermal imaging, georadar measurements (around and inside the tomb) and anthropological research of mummified remains as well - the complete dataset was collected. Through the integration of terrestrial (TLS) and airborne laser scanning (ALS) authors managed to analyse the surroundings of Fahrenheid pyriamid and influence of some objects (like trees) on the condition and visibility of the Pyramids in the landscape.

  17. Dr. von Braun With Management Team

    NASA Technical Reports Server (NTRS)

    1961-01-01

    Dr. von Braun is shown in this photograph, which was probably taken in the early 1960s, with members of his management team. Pictured from left to right are, Werner Kuers, Director of the Manufacturing Engineering Division; Dr. Walter Haeussermarn, Director of the Astrionics Division; Dr. William Mrazek, Propulsion and Vehicle Engineering Division; Dr. von Braun; Dieter Grau, Director of the Quality Assurance Division; Dr. Oswald Lange, Director of the Saturn Systems Office; and Erich Neubert , Associate Deputy Director for Research and Development.

  18. Childhood Picture of Dr. von Braun

    NASA Technical Reports Server (NTRS)

    1912-01-01

    This is a childhood picture of Dr. von Braun (center) with his brothers. Dr. Wernher von Braun was born in Wirsitz, Germany, March 23, 1912. His childhood dreams of marned space flight were fulfilled when giant Saturn rockets, developed under his direction at NASA's Marshall Space Flight Center, boosted the manned Apollo spacecraft to the Moon. His life was dedicated to expanding man's knowledge through the exploration of space.

  19. Childhood Picture of Dr. von Braun

    NASA Technical Reports Server (NTRS)

    1912-01-01

    This is a childhood picture of Dr. von Braun (center) with his brothers. Dr. Wernher von Braun was born in Wirsitz, Germany, March 23, 1912. His childhood dreams of marned space flight were fulfilled when giant Saturn rockets, developed under his direction at NASA's Marshall Space Flight Center, boosted the manned Apollo spacecraft to the Moon. His life was dedicated to expanding man's knowledge through the exploration of space.

  20. Renaturierung von Tagebaufolgeflächen

    NASA Astrophysics Data System (ADS)

    Tischew, Sabine

    Der Abbau von Rohstoffen im Tagebauverfahren bedingt einen tief greifenden Landschafts- und Strukturwandel in den betroffenen Regionen. In der Abbauphase hat vor allem der Braunkohleabbau mit den tagebauübergreifenden Grundwasserabsenkungstrichtern, der Zerstörung oder Beeinträchtigung von ausgedehnten naturnahen Auenökosystemen sowie Wäldern und Elementen der Kulturlandschaft aus der Sicht des Naturschutzes überwiegend negative landschaftsökologische Folgen. Vor allem der Eingriff in Ökosysteme mit langen Entwicklungszeiten (alte Wälder, Moore) oder in die Dynamik von Auensystemen ist nicht oder nur in sehr langen Zeiträumen wieder ausgleichbar. Für letztere ist auch langfristig die Durchgängigkeit für viele Tierarten (Arten der Fließgewässer) nicht wieder vollständig herstellbar. Oft ist es zudem schwierig, traditionelle Landnutzungen (z. B. Wanderschäferei, Nutzung von Streuobstwiesen) nach der langen Abbauphase wieder aufzugreifen. Es ist deshalb eine wichtige Aufgabe, nach dem Abbauprozess auf der Grundlage der vorhandenen Potenziale eine nachhaltige Entwicklung der Bergbaufolgelandschaft zu unterstützen und von den Betreibern des Abbaus und von den Sanierungsgesellschaften auch einzufordern (z. B. Bauer 1998).

  1. Von Karman re-visited

    NASA Astrophysics Data System (ADS)

    McEligot, Donald M.; Nolan, Kevin P.; Walsh, Edmond J.

    2012-11-01

    A number of authors have presented extended versions of the integral momentum equation, allowing for perturbations or fluctuations in the boundary layer. ``Conventional wisdom'' is that these added terms can be neglected and one can apply the von Karman version directly. For two-dimensional turbulent boundary layers at high Reynolds numbers, experience shows this assumption to be reasonable. However, recent examination of entropy generation in bypass transition with zero pressure gradient shows a term for turbulence energy convection can be important in determining the energy dissipation coefficient [Walsh et al., JFE 2011]. The present study employs the direct numerical simulations of Zaki and Durbin [JFM 2006] for bypass transition with streamwise pressure gradients to quantify the additional normal stress term when estimating the skin friction coefficient via a momentum balance. It is found that this term becomes noticeable in the pre-transitional laminar boundary layer and can exceed forty per cent of Cf in the transition region. Thus, it should be included in such calculations. Partly supported by U. S. DoE EPSCoR office.

  2. [Biology of von Willebrand factor].

    PubMed

    Girma, Jean-Pierre

    2006-01-01

    Von Willebrand factor (VWF) is a multimeric glycoprotein synthesized by megakaryocytes and endothelial cells. It is stored in platelets and endothelial cells and secreted towards subendothelium and plasma. VWF multimers consist of linear arrangements of identical subunits with a molecular weight of 270 kDa. The longest multimers reach more than 20 x 10(6) Da in storage granules. In the circulation, the multimer size is limited by the specific protease ADAMTS13. In primary hemostasis, VWF plays a key role as a molecular bridge in adhesion between platelets and subendothelium and between platelets during their aggregation. These functions, which involve the interaction with platelet glycoprotein lb, are mainly enhanced by VWF immobilization onto hydrophobic surfaces (collagen, cell membrane) and by high shear rates found in microcirculation and stenosed arteries. In these functions, the higher molecular weight forms are the most efficient. Under such hemodynamic conditions, proteolytic activity of ADAMTS13 is also optimal and limits the multimer size to about 15 x 10(6) Da as soon as their secretion. Thus ADAMTS13 appears as a key physiologic regulator of the VWF platelet functions. In the microcirculation, the lack of ADAMTS13 activity can result in the formation of VWF-rich platelet aggregates responsible for thrombotic thrombocytopenic purpura.

  3. Interaction of the von Willebrand factor with platelets and thrombosis.

    PubMed

    Perutelli, P; Mori, P G

    1997-11-01

    The human von Willebrand factor (vWf) is a multimeric glycoprotein present in plasma, platelets, endothelial cells and subendothelium and synthesized in endothelial cells and megakaryocytes. vWf plays a pivotal role in the mechanisms of blood clotting and platelet thrombus formation; quantitative and qualitative abnormalities of vWf cause the most common congenital bleeding disorder in man, the von Willebrand disease. vWf stabilizes factor VIII and interacts with subendothelial components and with platelet membrane receptors. The multimeric structure of vWf provides an array of binding sites which allows multivalent interactions with its ligands, thus supporting the formation of stable platelet aggregates at the site of vascular injury, particularly under flow conditions characterized by high shear stress. In the last years, remarkable progress has been made toward understanding the structure of vWf protein and gene, and the elucidation of many structure-function relationships, which may result in improved therapeutic intervention for vWD patients, and in the development of effective strategies for antithrombotic therapy.

  4. von Willebrand disease: advances in pathogenetic understanding, diagnosis, and therapy.

    PubMed

    Lillicrap, David

    2013-01-01

    von Willebrand disease (VWD) is the most common autosomally inherited bleeding disorder. The disease represents a range of quantitative and qualitative pathologies of the adhesive glycoprotein von Willebrand factor (VWF). The pathogenic mechanisms responsible for the type 2 qualitative variants of VWF are now well characterized, with most mutations representing missense substitutions influencing VWF multimer structure and interactions with platelet GPIbα and collagen and with factor VIII. The molecular pathology of type 3 VWD has been similarly well characterized, with an array of different mutation types producing either a null phenotype or the production of VWF that is not secreted. In contrast, the pathogenetic mechanisms responsible for type 1 VWD remain only partially resolved. In the hemostasis laboratory, the measurement of VWF:Ag and VWF:RCo are key components in the diagnostic algorithm for VWD, although the introduction of direct GPIbα-binding assays may become the functional assay of choice. Molecular genetic testing can provide additional benefit, but its utility is currently limited to type 2 and 3 VWD. The treatment of bleeding in VWD involves the use of desmopressin and plasma-derived VWF concentrates and a variety of adjunctive agents. Finally, a new recombinant VWF concentrate has just completed clinical trial evaluation and has demonstrated excellent hemostatic efficacy and safety.

  5. Developments in the diagnostic procedures for von Willebrand disease.

    PubMed

    De Jong, A; Eikenboom, J

    2016-03-01

    Von Willebrand disease (VWD) is the most common inherited bleeding disorder but its diagnosis can be challenging due to the heterogeneity of the disease. VWD is mainly associated with mild mucocutaneous bleeding, although there are more severe phenotypes with bleeding from the gastrointestinal tract or even the joints. Also, surgical interventions and trauma may lead to critical bleeding events. These bleeding episodes are all related to quantitative or qualitative defects of von Willebrand factor (VWF), a multimeric glycoprotein produced by endothelial cells and megakaryocytes, which mediates platelet adhesion and aggregation and binds factor VIII (FVIII) in the circulation. This review describes the diagnostic procedures required for correct diagnosis. Accurate diagnosis and classification is required for proper treatment and counseling. Assessment of bleeding starts with the medical history. After a positive bleeding or family history, subsequent laboratory investigations will start with a panel of standard screening tests for hemostatic defects. Patients suspected of having VWD will be tested for plasma VWF antigen levels, the ability of VWF to bind platelets and FVIII activity. When VWD is confirmed, a set of subtyping tests can classify the patients as VWD types 1, 2 (A, B, M or N) or 3. The performance of some additional assays and analyses, such as VWF propeptide measurement or genetic analysis, may help in identifying the pathological mechanism behind certain defects or can guide in the choice of treatment.

  6. Significant linkage and non-linkage of type 1 von Willebrand disease to the von Willebrand factor gene.

    PubMed

    Casaña, P; Martínez, F; Haya, S; Espinós, C; Aznar, J A

    2001-12-01

    Significant linkage of types 2A and 2B von Willebrand disease (VWD) to the von Willebrand factor (VWF) gene have been reported, as well as mutations in the VWF gene. However, data for the partial quantitative variant are less consistent. An inconsistency of association between the type 1 VWD phenotype and genotype has been reported recently. We undertook linkage analysis of 12 families with definite or possible type 1 VWD patients. One family with classic type 1 VWD had a high lod score (Z = 5.28, theta = 0.00). A total lod score of 10.68 was obtained for the four families with fully penetrant disease. In two families linkage was rejected, while three families did not show conclusive evidence of linkage. This study corroborates ABO blood group influence, especially in patients with mild deficiencies and/or incomplete penetrance. Indirect genetic analysis may be an option for diagnosing asymptomatic or presymptomatic type 1 VWD carriers, particularly in families showing higher penetrance. The study indicates defects of the VWF locus are to be expected in more than half of the families studied. However, as defects at different loci may be the cause of this phenotype, the results of the segregation analyses should be interpreted with caution, especially in studies involving small families, or mild expressions of the disorder or incomplete penetrance.

  7. An MRI Von Economo - Koskinas atlas.

    PubMed

    Scholtens, Lianne H; de Reus, Marcel A; de Lange, Siemon C; Schmidt, Ruben; van den Heuvel, Martijn P

    2016-12-28

    The cerebral cortex displays substantial variation in cellular architecture, a regional patterning that has been of great interest to anatomists for centuries. In 1925, Constantin von Economo and George Koskinas published a detailed atlas of the human cerebral cortex, describing a cytoarchitectonic division of the cortical mantle into over 40 distinct areas. Von Economo and Koskinas accompanied their seminal work with large photomicrographic plates of their histological slides, together with tables containing for each described region detailed morphological layer-specific information on neuronal count, neuron size and thickness of the cortical mantle. Here, we aimed to make this legacy data accessible and relatable to in vivo neuroimaging data by constructing a digital Von Economo - Koskinas atlas compatible with the widely used FreeSurfer software suite. In this technical note we describe the procedures used for manual segmentation of the Von Economo - Koskinas atlas onto individual T1 scans and the subsequent construction of the digital atlas. We provide the files needed to run the atlas on new FreeSurfer data, together with some simple code of how to apply the atlas to T1 scans within the FreeSurfer software suite. The digital Von Economo - Koskinas atlas is easily applicable to modern day anatomical MRI data and is made publicly available online.

  8. Association of the 3467C>T mutation (T1156M) in the von Willebrand's factor gene with dominant type 1 von Willebrand's disease.

    PubMed

    Casaña, P; Martínez, F; Haya, S; Espinós, C; Aznar, J A

    2001-07-01

    Type 1 is the most frequent form of von Willebrand's disease, which is characterized by a quantitative partial deficiency of von Willebrand's factor. At present, only two mutations located in the D3 domain (C1149R, C1130F) have been reported to cause the classic type 1 variant. The 3467C>T transition that predicts the T1156M amino acid change was detected in seven patients from one family and was not found in 110 normal alleles screened. This is a candidate mutation to cause dominant type 1 variant with complete penetrance. On the other hand, neither of the two mutations mentioned above has been detected in the other 15 families studied with type 1 or possible type 1 patients.

  9. Dr. Wernher Von Braun with Dr. Christian Barnard.

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Dr. Christian Barnard Tours Marshall Space Flight Center. Shown in Dr. Von Braun's office are (left to right): Dr. Ernst Sthulinger, a representative from General Electric, Dr. Wernher Von Braun, Dr. Christian Barnard, and Dr. Eberhard Rees.

  10. Dr. Wernher Von Braun with Dr. Christian Barnard.

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Dr. Christian Barnard Tours Marshall Space Flight Center. Shown in Dr. Von Braun's office are (left to right): Dr. Ernst Sthulinger, a representative from General Electric, Dr. Wernher Von Braun, Dr. Christian Barnard, and Dr. Eberhard Rees.

  11. State of the art: von Willebrand disease.

    PubMed

    James, A H; Eikenboom, J; Federici, A B

    2016-07-01

    The State of the Art in von Willebrand disease (VWD) has been impacted not only by discoveries in the field of haemostasis, but also by changes in practice in other fields. The development of bleeding assessment tools has led to the clarification of bleeding symptoms and phenotype in VWD. New discoveries in the biology and genetics of von Willebrand factor (VWF) are challenging our existing diagnostics and classification(s). An improved understanding of reproductive physiology and the pathology of VWD along with changing obstetric, gynaecologic and haemostatic therapies necessitate an evolving response to the care of women with VWD. The survival of patients with autoimmune disease, malignancies and congenital heart disease along with increasing use of circulatory support devices and extracorporeal membrane oxygenation is increasing the prevalence of acquired von Willebrand syndrome. In each of these challenges, there are opportunities to improve the care of our patients with VWD.

  12. Treatment of the acquired von Willebrand syndrome.

    PubMed

    Budde, Ulrich; Scheppenheim, Sonja; Dittmer, Rita

    2015-12-01

    Acquired von Willebrand syndrome (aVWS) accounts for 22% of patients with abnormal von Willebrand factor. Most patients with known pathophysiological mechanisms suffer from cardiovascular, myeloproliferative and lymphoproliferative disorders. Less frequent associations are of autoimmune origin, due to hyperfibrinolysis, adsorption to tumor cells, reduced synthesis and prolonged circulation. The mechanisms leading to aVWS is hitherto not known in patients with liver and kidney diseases, drug use, glycogen storage disease, virus infections and at least 18 other disease entities. Diagnosis is complicated by the battery of tests needed, and their inherent rather low sensitivity and specificity for aVWS. Thus, even in acute bleeding situations it may take days until a firm diagnosis is settled and specific therapies can be initiated. The main aim is to shed more light onto this, compared with inherited von Willebrand disease, rare disease which affects at least 2-3% of the older population.

  13. Liouville-von Neumann molecular dynamics.

    PubMed

    Jakowski, Jacek; Morokuma, Keiji

    2009-06-14

    We present a novel first principles molecular dynamics scheme, called Liouville-von Neumann molecular dynamics, based on Liouville-von Neumann equation for density matrices propagation and Magnus expansion of the time-evolution operator. The scheme combines formally accurate quantum propagation of electrons represented via density matrices and a classical propagation of nuclei. The method requires a few iterations per each time step where the Fock operator is formed and von Neumann equation is integrated. The algorithm (a) is free of constraint and fictitious parameters, (b) avoids diagonalization of the Fock operator, and (c) can be used in the case of fractional occupation as in metallic systems. The algorithm is very stable, and has a very good conservation of energy even in cases when a good quality conventional Born-Oppenheimer molecular dynamics trajectories is difficult to obtain. Test simulations include initial phase of fullerene formation from gaseous C(2) and retinal system.

  14. Liouville-von Neumann molecular dynamics

    NASA Astrophysics Data System (ADS)

    Jakowski, Jacek; Morokuma, Keiji

    2009-06-01

    We present a novel first principles molecular dynamics scheme, called Liouville-von Neumann molecular dynamics, based on Liouville-von Neumann equation for density matrices propagation and Magnus expansion of the time-evolution operator. The scheme combines formally accurate quantum propagation of electrons represented via density matrices and a classical propagation of nuclei. The method requires a few iterations per each time step where the Fock operator is formed and von Neumann equation is integrated. The algorithm (a) is free of constraint and fictitious parameters, (b) avoids diagonalization of the Fock operator, and (c) can be used in the case of fractional occupation as in metallic systems. The algorithm is very stable, and has a very good conservation of energy even in cases when a good quality conventional Born-Oppenheimer molecular dynamics trajectories is difficult to obtain. Test simulations include initial phase of fullerene formation from gaseous C2 and retinal system.

  15. Mittelwert- und Arbeitstaktsynchrone Simulation von Dieselmotoren

    NASA Astrophysics Data System (ADS)

    Zahn, Sebastian

    Getrieben durch die immer restriktiveren Anforderungen an das Emissions- und Verbrauchsverhalten moderner Verbrennungsmotoren steigt die Komplexität von Motormanagementsystemen mit jeder Modellgeneration an. Damit geht nicht nur eine Zunahme des Softwareumfangs von Steuergeräten sondern zugleich ein deutlicher Anstieg des Applikations-, Vermessungs- und Testaufwandes einher. Zur Effizienzsteigerung des Software- und Funktionsentwicklungsprozesses haben sich daher in der Automobilindustrie sowie in Forschungsinstituten verschiedene modell- und simulationsbasierte Methoden wie die Model-in-the-Loop (MiL) Simulation, die Software-in-the-Loop (SiL) Simulation, das Rapid Control Prototyping (RCP) sowie die Hardware-in-the-Loop (HiL) Simulation etabliert.

  16. [Research advance in von Willebrand factor].

    PubMed

    Li, Xue-Mei; Jiang, Miao; Zhao, Yi-Ming

    2013-06-01

    von Willebrand factor (vWF) is a multimeric glycoprotein exclusively synthesized in endothelial cells and megakaryocytes. It plays important roles in the primary and secondary haemostasis. Deficiency or dysfunction of vWF may cause von Willebrand disease (vWD), and overexpression of vWF may cause thrombosis. Making an intensive study on vWF will help us to understand the pathophysiology, diagnosis and treatment of vWF-related diseases, such as vWD, TTP, venous thrombosis, stroke, and so on. In this article, the regulation of vWF activity and its relation with diseases mentioned above are reviewed.

  17. Laboratory diagnosis of von Willebrand disease.

    PubMed

    Roberts, J C; Flood, V H

    2015-05-01

    Von Willebrand disease (VWD) is considered the most common inherited bleeding disorder and may also be the most difficult to diagnose. Clinical symptoms of VWD include predominantly mild mucosal bleeding; surgical bleeding may occur with specific challenges and joint bleeding can occur in the most severe forms. A family history either of diagnosed VWD or of bleeding symptoms is typically present. Laboratory diagnosis requires a series of assays of von Willebrand factor (VWF) quantity and function, and factor VIII activity, with no single straightforward diagnostic test available to either confirm or exclude the diagnosis. Newer assays of VWF function are becoming more available and useful in determining the laboratory diagnosis of VWD.

  18. Level-Set-Segmentierung von Rattenhirn MRTs

    NASA Astrophysics Data System (ADS)

    Eiben, Björn; Kunz, Dietmar; Pietrzyk, Uwe; Palm, Christoph

    In dieser Arbeit wird die Segmentierung von Gehirngewebe aus Kopfaufnahmen von Ratten mittels Level-Set-Methoden vorgeschlagen. Dazu wird ein zweidimensionaler, kontrastbasierter Ansatz zu einem dreidimensionalen, lokal an die Bildintensität adaptierten Segmentierer erweitert. Es wird gezeigt, dass mit diesem echten 3D-Ansatz die lokalen Bildstrukturen besser berücksichtigt werden können. Insbesondere Magnet-Resonanz-Tomographien (MRTs) mit globalen Helligkeitsgradienten, beispielsweise bedingt durch Oberfiächenspulen, können auf diese Weise zuverlässiger und ohne weitere Vorverarbeitungsschritte segmentiert werden. Die Leistungsfähigkeit des Algorithmus wird experimentell an Hand dreier Rattenhirn-MRTs demonstriert.

  19. Ökologische Aspekte von Thin Clients

    NASA Astrophysics Data System (ADS)

    von Knermann, Christian

    Hersteller von IT-Technologie haben angesichts der Debatte um Klimaschutz und Nachhaltigkeit erkannt, dass für Endkunden, ob privat oder gewerblich, auch ökologische Gesichtspunkte beim Kauf von PC, Laptop oder Netzwerkgeräten eine immer größere Rolle spielen und Energie- oder Ökoeffizienz der Geräte kaufentscheidend wirken können. Betrachtet und bewertet wurden bislang aber hauptsächlich isolierte Einzelaspekte, wie der Energieverbrauch in der Nutzungsphase oder der Einsatz toxikologisch unbedenklicher Stoffe. Was fehlt, ist eine ganzheitliche Ausrichtung auf Nachhaltigkeit über die Lebensphasen Produktion, Nutzung sowie Recyling/Entsorgung.

  20. Biosynthesis, processing and secretion of von Willebrand factor: biological implications.

    PubMed

    de Wit, T R; van Mourik, J A

    2001-06-01

    von Willebrand factor is a multimeric plasma glycoprotein that is required for normal haemostasis. von Willebrand factor is synthesized by endothelial cells and megakaryocytes, and originates from its precursor pro-von Willebrand factor. The endoproteolytic processing of pro-von Willebrand factor results in mature von Willebrand factor and von Willebrand factor propeptide (also known as von Willebrand Ag II). In endothelial cells, the propeptide controls the polymerization and subsequent targeting of von Willebrand factor to the storage vesicles, the so-called Weibel-Palade bodies. Upon stimulation of the endothelial cells, the Weibel-Palade bodies are translocated to the plasma membrane of the cell, and mature von Willebrand factor and its propeptide are co-secreted. After release, these polypeptides have divergent fates and serve different biological functions. Mature von Willebrand factor both controls platelet adhesion and aggregation at sites of vascular injury and acts as a chaperone protein for coagulation factor VIII. The von Willebrand factor propeptide may serve a role in modulating inflammatory processes. This still growing body of information indicates that the biological function of the von Willebrand factor gene product is more diverse than was previously thought.

  1. Dr. von Braun Visits Huntsville Boys Club

    NASA Technical Reports Server (NTRS)

    1961-01-01

    Dr. von Braun, Director of Marshall Space Flight Center (MSFC) and chairman of this year's United Givers Fund (UGF) drive at MSFC, takes time out from the problems of sending a man to the Moon to talk baseball with 11-year-old Randy Smith at the Huntsville Boys Club.

  2. Dr. von Braun and His Mercedes

    NASA Technical Reports Server (NTRS)

    1959-01-01

    In this picture, Dr. Wernher von Braun, who was serving as Director of the Army Ballistic Missile Agency's (ABMA) Development Operations Division, is shown posed with his Mercedes 220SE automobile in front of Redstone Building 4488, which houses the ABMA.

  3. [The Costantin Von Economo's lethargic encefalitis

    PubMed

    Pistacchio, E.

    1998-01-01

    Starting from the Constantin Von Economo's description of a "new" disease, the lethargic encephalitis, the author delineates the history of an infectious sleeping sickness that caused epidemics in Europe from 1917 to 1928 and led to create, in Italy, the "Institutes for Encephalitis".

  4. Dr. Wernher Von Braun presents a certificate

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Dr. Wernher Von Braun (left), director of the Marshall Space Flight Center, presents a humorous certificate to Major General Charles W. Eifler, commanding general of Redstone Arsenal, at the close of a farewell luncheon for the general prior to General Eifler moving to a new European duty station.

  5. Alexander von Humboldt: a revolutionary explorer.

    PubMed

    Fara, Patricia

    2008-03-01

    After he returned from his five-year expedition to the New World, Alexander von Humboldt promoted himself as a Romantic explorer. Although this image pervades British perceptions, political movements have fashioned different heroic versions of Humboldt in Germany and South America.

  6. Dr. Wernher Von Braun presents a certificate

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Dr. Wernher Von Braun (left), director of the Marshall Space Flight Center, presents a humorous certificate to Major General Charles W. Eifler, commanding general of Redstone Arsenal, at the close of a farewell luncheon for the general prior to General Eifler moving to a new European duty station.

  7. Dr. von Braun Discusses 'Bottle Suit' Concept

    NASA Technical Reports Server (NTRS)

    1954-01-01

    Dr. Wernher von Braun (center), then Chief of the Guided Missile Development Division at Redstone Arsenal, Alabama, discusses a 'bottle suit' model with Dr. Heinz Haber (left), an expert on aviation medicine, and Willey Ley, a science writer on rocketry and space exploration. The three men were at the Disney studios appearing in the motion picture, entitled 'Man in Space.'

  8. Dr. von Braun Discusses 'Bottle Suit' Concept

    NASA Technical Reports Server (NTRS)

    1954-01-01

    Dr. Wernher von Braun (center), then Chief of the Guided Missile Development Division at Redstone Arsenal, Alabama, discusses a 'bottle suit' model with Dr. Heinz Haber (left), an expert on aviation medicine, and Willey Ley, a science writer on rocketry and space exploration. The three men were at the Disney studios appearing in the motion picture, entitled 'Man in Space.'

  9. Critical assessment of von Mises distribution and an infinite series ansatz for self-propelled particles

    NASA Astrophysics Data System (ADS)

    Kürsten, Rüdiger; Ihle, Thomas

    2017-03-01

    We consider a Vicsek model of self-propelled particles with bounded confidence, where each particle interacts only with neighbors that have a similar direction. Depending on parameters, the system exhibits a continuous or discontinuous polar phase transition from the isotropic phase to a phase with a preferred direction. In a recent paper (Lam, Schindler and Dauchot 2015 J. Stat. Mech. P10017) the von Mises distribution was proposed as an ansatz for polar ordering. In the present system the time evolution of the angular distribution can be solved in Fourier space. We compare the results of the Fourier analysis with the ones obtained by using the von Mises distribution ansatz. In the latter case the qualitative behavior of the system is recovered correctly. However, quantitatively there are serious deviations. We introduce an extended von Mises distribution ansatz such that a second term takes care of the next two Fourier modes. With the extended ansatz we find much better quantitative agreement. As an alternative approach we also use a Gaussian and a geometric series ansatz in Fourier space. The geometric series ansatz is analytically handable but fails for very weak noise, the Gaussian ansatz yields better results but it is not analytically treatable.

  10. A note on derivations of Murray–von Neumann algebras

    PubMed Central

    Kadison, Richard V.; Liu, Zhe

    2014-01-01

    A Murray–von Neumann algebra is the algebra of operators affiliated with a finite von Neumann algebra. In this article, we first present a brief introduction to the theory of derivations of operator algebras from both the physical and mathematical points of view. We then describe our recent work on derivations of Murray–von Neumann algebras. We show that the “extended derivations” of a Murray–von Neumann algebra, those that map the associated finite von Neumann algebra into itself, are inner. In particular, we prove that the only derivation that maps a Murray–von Neumann algebra associated with a factor of type II1 into that factor is 0. Those results are extensions of Singer’s seminal result answering a question of Kaplansky, as applied to von Neumann algebras: The algebra may be noncommutative and may even contain unbounded elements. PMID:24469831

  11. [Von Willebrand disease. Molecular biology and diagnosis].

    PubMed

    Hernández-Zamora, Edgar; Zavala-Hernández, Cesar; Quintana-González, Sandra; Reyes-Maldonado, Elba

    2015-01-01

    Von Willebrand disease is the most common inherited disorder of the coagulation proteins in humans. There are three types: 1, 2A, 2B, 2N, 2M and 3. It is associated with mutations on chromosome 12 in the region p13.2, encoding the von Willebrand factor (VWF), which is synthesized in endothelial cells and megakaryocytes. The VWF gene has been characterised using molecular biology techniques, which have acquired an important role in diagnosis von Willebrand disease, as well as in the investigation of alterations in other genes, which may be involved in regulating the synthesis, processing, and secretion of VWF. However, there are still no strategies to integrate the molecular biology diagnostic tests available. Analysis of VWF multimers is a methodology that meets the characteristics for diagnosis, but it is not easy to standardise. Considering that even in tertiary centres in our country, von Willebrand patients do not have a definitive diagnosis, it is necessary to implement these methodologies to study and improve diagnosis. Von Willebrand disease is highly heterogeneous due to the molecular mechanisms that produce the various clinical and laboratory phenotypes. In Mexico there are few studies related to this disease; therefore it is essential to conduct a comprehensive study including clinical, basic, and special testing laboratory tests, in order to establish a correct diagnosis, develop new therapeutic approaches, and offer the appropriate medical care and genetic counselling. Copyright © 2015 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.

  12. Galerkin analysis of kinematic dynamos in the von Kármán geometry

    NASA Astrophysics Data System (ADS)

    Marié, L.; Normand, C.; Daviaud, F.

    2006-01-01

    We investigate dynamo action by solving the kinematic dynamo problem for velocity fields of the von Kármán type between two coaxial counter-rotating propellers in a cylinder. A Galerkin method is implemented that takes advantage of the symmetries of the flow and their subsequent influence on the nature of the magnetic field at the dynamo threshold. Distinct modes of instability have been identified that differ by their spatial and temporal behaviors. Our calculations give the result that a stationary and antisymmetric mode prevails at the dynamo threshold. We then present a quantitative analysis of the results based on the parametric study of four interaction coefficients obtained by reduction of our initially large eigenvalue problem. We propose these coefficients to measure the relative importance of the different mechanisms at play in the von Kármán kinematic dynamo.

  13. Current controversies in the diagnosis and management of von Willebrand disease.

    PubMed

    Neff, Anne T

    2015-08-01

    Von Willebrand disease (VWD) is the most common inherited bleeding disorder in the world. The spectrum of VWD spans quantitative and qualitative deficiencies of von Willebrand factor (VWF), a platelet adhesive protein. It manifests primarily as mucocutaneous bleeding, but severely affected patients may suffer soft tissue bleeding and hemarthroses. There is disagreement in the multiple guidelines published regarding diagnosis, especially of type 1 VWD, which also remains the most opaque with respect to molecular characterization. Treatment with desmopressin (DDAVP) is most effective in type 1 VWD, but regimens are not standardized. It is not clear which type 2 VWD patients with qualitative deficiencies can be treated with DDAVP and which ones should receive VWF concentrates. No guidelines stipulate which patients might benefit from prophylactic VWF infusions and how they should be dosed. These are some current controversies in VWD that are discussed in this review.

  14. Current controversies in the diagnosis and management of von Willebrand disease

    PubMed Central

    2015-01-01

    Von Willebrand disease (VWD) is the most common inherited bleeding disorder in the world. The spectrum of VWD spans quantitative and qualitative deficiencies of von Willebrand factor (VWF), a platelet adhesive protein. It manifests primarily as mucocutaneous bleeding, but severely affected patients may suffer soft tissue bleeding and hemarthroses. There is disagreement in the multiple guidelines published regarding diagnosis, especially of type 1 VWD, which also remains the most opaque with respect to molecular characterization. Treatment with desmopressin (DDAVP) is most effective in type 1 VWD, but regimens are not standardized. It is not clear which type 2 VWD patients with qualitative deficiencies can be treated with DDAVP and which ones should receive VWF concentrates. No guidelines stipulate which patients might benefit from prophylactic VWF infusions and how they should be dosed. These are some current controversies in VWD that are discussed in this review. PMID:26288715

  15. A double commutant theorem for Murray-von Neumann algebras.

    PubMed

    Liu, Zhe

    2012-05-15

    Murray-von Neumann algebras are algebras of operators affiliated with finite von Neumann algebras. In this article, we study commutativity and affiliation of self-adjoint operators (possibly unbounded). We show that a maximal abelian self-adjoint subalgebra A of the Murray-von Neumann algebra A(f)(R) associated with a finite von Neumann algebra R is the Murray-von Neumann algebra A(f)(A(0)), where A(0) is a maximal abelian self-adjoint subalgebra of R and, in addition, A(0) is A Π R. We also prove that the Murray-von Neumann algebra A(f)(C) with C the center of R is the center of the Murray-von Neumann algebra A(f)(R). Von Neumann's celebrated double commutant theorem characterizes von Neumann algebras R as those for which R'' = R, where R', the commutant of R, is the set of bounded operators on the Hilbert space that commute with all operators in R. At the end of this article, we present a double commutant theorem for Murray-von Neumann algebras.

  16. From the classical to the generalized von Karman and Marguerre-von Karman equations

    NASA Astrophysics Data System (ADS)

    Ciarlet, Philippe G.; Gratie, Liliana

    2006-06-01

    In this work, we describe and analyze two models that were recently proposed for modeling generalized von Karman plates and generalized Marguerre-von Karman shallow shells.First, we briefly review the "classical" von Karman and Marguerre-von Karman equations, their physical meaning, and their mathematical justification. We then consider the more general situation where only a portion of the lateral face of a nonlinearly elastic plate or shallow shell is subjected to boundary conditions of von Karman type, while the remaining portion is free. Using techniques from formal asymptotic analysis, we obtain in each case a two-dimensional boundary value problem that is analogous to, but is more general than, the classical equations.In particular, it is remarkable that the boundary conditions for the Airy function can still be determined on the entire boundary of the nonlinearly elastic plate or shallow shell solely from the data.Following recent joint works, we then reduce these more general equations to a single "cubic" operator equation, which generalizes an equation introduced by Berger and Fife, and whose sole unknown is the vertical displacement of the shell. We next adapt an elegant compactness method due to Lions for establishing the existence of a solution to this operator equation.

  17. Management of the von Roos operator

    NASA Astrophysics Data System (ADS)

    Molinar-Tabares, Martin; Castro-Arce, Lamberto; Figueroa-Navarro, Carlos; Campos-Garcia, Julio

    When an electron is inside a semiconductor medium its effective mass rises from the shielding of the crystalline structure. When we have a semiconductor with a constant concentration the effective mass has a fixed value, and in this case, it can be easy to solve the Schrodinger equation of the particle, but if the concentration varies spatially, the effective mass will no longer constant and the solution can be difficult to find. The general form of the kinetic energy operator for a particle with variable mass is proposed for von Roos, this operator is characterized by some parameters whose values are subjected to a restriction. From a numerical solution of the Schrodinger equation we analyze the energies of an electron with position-dependent effective mass working with some values of the parameter of the von Roos operator. We acknowledge the support of SNI CONACYT.

  18. [Molecular biology of von Willebrand disease].

    PubMed

    Melo-Nava, Brenda; Peñaloza, Rosenda

    2007-01-01

    Von Willebrand Factor (VWF) is a large multimeric glycoprotein expressed in the megakaryocytes and endothelial cells of all vertebrates. It participates fundamentally in the primary and secondary hemostasis because it induces the adhesion of platelets to vascular subendothelium and promotes aggregation of platelets when blood vessels and capillaries are damaged. In addition, VWF links to factor VIII which avoids its proteolysis. The deficiency or the inadequate synthesis of the VWF causes von Willebrand disease (VWD), which is the most common hereditary bleeding disorder in humans principally from mucous and cutaneous sites. VWD is difficult to detect with accuracy due to interrelation among VWF with different components of hemostasis, although it is performed by different tests of haemostatic system, and the basic mechanisms in VWD are herein emphasized. The diagnosis of VWD is difficult due to the heterogeneous manifestation of the disease, which also complicates its classification. This article focuses on the molecular aspects of the disease and discusses their possible clinical implications.

  19. Vascular Manifestations of von Recklinghausen's Disease

    PubMed Central

    Fye, Kenneth H.; Jacobs, Richard P.; Roe, Robert L.

    1975-01-01

    A casual relationship between von Recklinghausen's disease, or neurofibromatosis, and arteriolar abnormalities has been reported in the European literature. A patient was seen who had biopsy-proved neurofibromatosis and renovascular hypertension and retroperitoneal bleeding. An arteriographic study showed multiple small aneurysms throughout the coeliac axis, the superior mesenteric artery and in several small intrarenal vessels. Renal vein renin levels were elevated particularly in the right renal vein, supporting the diagnosis of renovascular hypertension. Both the aneurysms seen in angiographic studies and the retroperitoneal hemorrhage are probably vascular manifestations of von Recklinghausen's disease. Support for this conclusion is enhanced by the absence of clinical, laboratory or histologic data supporting the only tenable differential diagnosis, periarteritis nodosa. ImagesFigure 1.Figure 2.Figure 3.Figure 4. PMID:803743

  20. Herstellung von Chitosan und einige Anwendungen

    NASA Astrophysics Data System (ADS)

    Struszczyk, Marcin Henryk

    2001-05-01

    1. Die Deacetylierung von crabshell - Chitosan führte gleichzeitig zu einem drastischen Abfall der mittleren viscosimetrischen Molmasse ( Mv), insbesondere wenn die Temperatur und die Konzentration an NaOH erhöht werden. Diese Parameter beeinflussten jedoch nicht den Grad der Deacetylierung (DD). Wichtig ist jedoch die Quelle des Ausgangsmaterials: Chitin aus Pandalus borealis ist ein guter Rohstoff für die Herstellung von Chitosan mit niedrigem DD und gleichzeitig hoher mittlerer Mv, während Krill-Chitin (Euphausia superba) ein gutes Ausgangsmaterial zur Herstellung von Chitosan mit hohem DD und niedrigem Mv ist. Chitosan, das aus Insekten (Calliphora erythrocephala), unter milden Bedingungen (Temperatur: 100°C, NaOH-Konzentration: 40 %, Zeit: 1-2h ) hergestellt wurde, hatte die gleichen Eigenschaften hinsichtlich DD und Mv wie das aus Krill hergestellte Chitosan. Der Bedarf an Zeit, Energie und NaOH ist für die Herstellung von Insekten-Chitosan geringer als für crabshell-Chitosan vergleichbare Resultaten für DD und Mv. 2. Chitosan wurde durch den Schimmelpilz Aspergillus fumigatus zu Chitooligomeren fermentiert. Die Ausbeute beträgt 25%. Die Chitooligomere wurden mit Hilfe von HPLC und MALDI-TOF-Massenspektrmetrie identifiziert. Die Fermentationsmischung fördert die Immunität von Pflanzen gegen Bakterien und Virusinfektion. Die Zunahme der Immunität schwankt jedoch je nach System Pflanze-Pathogen. Die Fermentation von Chitosan durch Aspergillus fumigatus könnte eine schnelle und billige Methode zur Herstellung von Chitooligomeren mit guter Reinheit und Ausbeute sein. Eine partiell aufgereinigte Fermentationsmischung dieser Art könnte in der Landwirtschaft als Pathogeninhibitor genutzt werden. Durch kontrollierte Fermentation, die Chitooligomere in definierter Zusammensetzung (d.h. definierter Verteilung des Depolymerisationsgrades) liefert, könnte man zu Mischungen kommen, die für die jeweilige Anwendung eine optimale Bioaktivität besitzen. 3

  1. Verbesserung der Symmetrie von Hirnaufnahmen entlang der Sagittalebene

    NASA Astrophysics Data System (ADS)

    Ens, Konstantin; Wenzel, Fabian; Fischer, Bernd

    Die lokale Symmetrie von Hirnscans entlang der Sagittalebene zu ermitteln und zu modizifieren, ist für eine Reihe neurologischer Anwendungen interessant. Beispielsweise kann der voxelweise Vergleich von rechter und linker Hirnhälfte nur dann Aufschluss über die Lokalisierung von Läsionen geben, wenn durch Transformation ein Hirnscan eine möglichst hohe Symmetrie aufweist. Ein weiteres Anwendungsgebiet ist die Visualisierung von medialen Hirnschnitten, für die die Trennfläche beider Hirnhälfte möglichst eben sein sollte. Diese Arbeit stellt die Entwicklung eines Verfahrens vor, mit dessen Hilfe die Symmetrie von Hirnaufnahmen entlang der Sagittalebene verbessert werden kann. Dies geschieht unter Verwendung von aktiven Konturen, die mit Hilfe einer neuartigen Kostenfunktion gesteuert werden. Experimente am Ende der Arbeit mit strukturellen Kernspinaufnahmen demonstrieren die Leistungsfähigkeit des Verfahrens.

  2. Portrait of Dr. Von Braun with Walt Disney, 1954.

    NASA Technical Reports Server (NTRS)

    1954-01-01

    Marshall Center Director Dr. Wernher Von Braun is pictured with Walt Disney during a visit to the Marshall Space Flight Center in 1954. In the 1950s, Dr. Von Braun while working in California on the Saturn project, also worked with Disney studios as a technical director in making three films about Space Exploration for television. Disney's tour of Marshall in 1965 was Von Braun's hope for a renewed public interest in the future of the Space Program at NASA.

  3. Portrait of Dr. Von Braun with Walt Disney, 1954.

    NASA Technical Reports Server (NTRS)

    1954-01-01

    Marshall Center Director Dr. Wernher Von Braun is pictured with Walt Disney during a visit to the Marshall Space Flight Center in 1954. In the 1950s, Dr. Von Braun while working in California on the Saturn project, also worked with Disney studios as a technical director in making three films about Space Exploration for television. Disney's tour of Marshall in 1965 was Von Braun's hope for a renewed public interest in the future of the Space Program at NASA.

  4. Dr. von Braun and Army Ballistics Missile Agency (ABMA) Group

    NASA Technical Reports Server (NTRS)

    1959-01-01

    This photograph of Dr. von Braun, shown here to the left of General Bruce Medaris, was taken in the fall of 1959, immediately prior to Medaris' retirement from the Army. At the time, von Braun and his associates worked for the Army Ballistics Missile Agency in Huntsville, Alabama. Those in the photograph have been identified as Ernst Stuhlinger, Frederick von Saurma, Fritz Mueller, Hermarn Weidner, E.W. Neubert (partially hidden), W.A. Mrazek, Karl Heimburg, Arthur Rudolph, Otto Hoberg, von Braun, Oswald Lange, Medaris, Helmut Hoelzer, Hans Maus, E.D. Geissler, Hans Heuter, and George Constan.

  5. PT2385 for the Treatment of Von Hippel-Lindau Disease-Associated Clear Cell Renal Cell Carcinoma

    ClinicalTrials.gov

    2017-04-04

    VHL Gene Mutation; VHL; VHL Syndrome; VHL Gene Inactivation; Von Hippel; Von Hippel-Lindau Disease; Von Hippel's Disease; Von Hippel-Lindau Syndrome, Modifiers of; Clear Cell Renal Cell Carcinoma; Clear Cell RCC; ccRCC

  6. How I treat type 2 variant forms of von Willebrand disease.

    PubMed

    Tosetto, Alberto; Castaman, Giancarlo

    2015-02-05

    Type 2 von Willebrand disease (VWD) includes a wide range of qualitative abnormalities of von Willebrand factor structure and function resulting in a variable bleeding tendency. According to the current classification, 4 different subtypes can be identified, each with distinctive phenotypic and therapeutic characteristics. Current available laboratory methods allow a straightforward approach to VWD subtyping, and although the precise molecular characterization remains complex, it is not required for appropriate treatment of the vast majority of cases. Desmopressin can be useful only in a few type 2 cases compared with patients with actual quantitative deficiency (type 1), most often in variants with a nearly normal multimeric pattern (type 2M). However, since no laboratory test accurately predicts response to desmopressin, a trial test should always be performed in all type 2 VWD patients, with the exception of type 2B ones. Replacement therapy with plasma-derived von Willebrand factor-factor VIII concentrates represents the safe mainstay of treatment of all patients, particularly those not responding to desmopressin or requiring a sustained hemostatic correction because of major surgery or bleeding. A significant patient bleeding history correlates with increased bleeding risk and should be considered in tailoring the optimal antihemorrhagic prophylaxis in the individual patient.

  7. Genetic mutations in von Willebrand disease identified by DHPLC and DNA sequence analysis.

    PubMed

    Kakela, Justin K; Friedman, Kenneth D; Haberichter, Sandra L; Buchholz, Nadine P; Christopherson, Pam A; Kroner, Philip A; Gill, Joan Cox; Montgomery, Robert R; Bellissimo, Daniel B

    2006-03-01

    Von Willebrand disease (VWD) is a common inherited bleeding disorder caused by quantitative (types 1 and 3) and qualitative (type 2) defects in von Willebrand factor (VWF). The VWF gene is a large gene containing 52 exons; except for type 2 VWD, the majority of mutations causing VWD are not localized to specific exons. We have used denaturing high performance liquid chromatography (DHPLC) to scan the coding region of the VWF gene for sequence variations. Primers were designed to amplify all 52 exons while avoiding amplification of the VWF pseudogene. Exon-specific primers were designed with sequencing primers, allowing direct sequencing of each VWF exon. Sequence variations in 33 previously characterized von Willebrand disease (VWD) samples were all detected using DHPLC demonstrating the high sensitivity of this technique. In addition, we analyzed 42 patients or family members with VWD. Thirty-two novel sequence variations were identified (2 deletions, 2 nonsense, 15 missense, 6 silent, and 7 intronic), some with clear functional consequences. A previously described deletion in exon 18, 2435delC, was also found in two unrelated type 3 patients. This DHPLC and DNA sequencing technique will enable the full length assessment of the VWF gene necessary to detect mutations causing types 1 and 3 VWD.

  8. Tight junctions in Gerbil von Ebner's gland: horseradish peroxidase and freeze-fracture studies.

    PubMed

    Huang, Anthony Y; Chen, Ming-Huei; Wu, Sandy Y; Lu, Kuo-Shyan

    2015-03-01

    The permeability of tight junctions to horseradish peroxidase (HRP) and the freeze-fracture appearance of junctional structures were investigated in the von Ebner's gland of gerbils. In the tracing study, HRP was either administered topically on the dorsal surface of tongues or injected subepithelially into the connective tissue of vallate papillae for 5-30 min. Lingual tissues containing the von Ebner's gland were sectioned and examined by light and electron microscopy. In von Ebner's glands, the reaction product for HRP was found in the intercellular and interstitial spaces, whereas HRP appeared to penetrate the tight junctions and the reaction product was localized in the lumina of serous acini. In contrast, the staining for HRP that delineated the boundary of epithelial cells was frequently observed in the superficial layers of the lingual epithelium but not the underlying tissues while applying HRP topically. Freeze-fracture replicas of acinar cells revealed that the tight junction had a depth of 0.815 ± 0.023 μm, and 4-6 parallel strands on the protoplasmic fracture face, with a branching network of joining strands with interruptions, interconnections and high linear strand density apically, and corresponding grooves on the extracellular face. Quantitative analyses showed a greater number of strands (7.217 ± 0.326) in gerbils compared to those of acinar cells (3.86 ± 0.22) in mice. These results demonstrate that the tight junctions in the gerbil von Ebner's gland is permeable, and that specific species differences in tight junction structures may be associated with the mechanism for survival in an extremely dry environment. © 2015 Wiley Periodicals, Inc.

  9. Key contributors: Ernst von Glasersfeld's radical constructivism

    NASA Astrophysics Data System (ADS)

    Tobin, Kenneth

    2007-07-01

    This article reviews the significance of the contributions of Ernst von Glasersfeld to research in science education, especially through his theoretical contributions on radical constructivism. As a field shaper, Glasersfeld's subversive ideas catalyzed debate in the science education community and fuelled transformation of many facets including research methods, ways of thinking about teaching and learning, curriculum, and science teacher education. Perturbations emanating from the debates on constructivism forged new pathways that led to the development and use of many of the sociocultural frameworks employed by authors in Cultural Studies of Science Education.

  10. Approximating incompatible von Neumann measurements simultaneously

    SciTech Connect

    Heinosaari, Teiko; Jivulescu, Maria Anastasia; Reitzner, Daniel; Ziman, Mario

    2010-09-15

    We study the problem of performing orthogonal qubit measurements simultaneously. Since these measurements are incompatible, one has to accept additional imprecision. An optimal joint measurement is the one with the least possible imprecision. All earlier considerations of this problem have concerned only joint measurability of observables, while in this work we also take into account conditional state transformations (i.e., instruments). We characterize the optimal joint instrument for two orthogonal von Neumann instruments as being the Lueders instrument of the optimal joint observable.

  11. [Albrecht von Haller. An illustrious ancestor].

    PubMed

    Peiper, H-J

    2008-05-01

    Albrecht von Haller (1708-1777) was one of the most famous and important men of the eighteenth century. His achievements make him comparable with Lessing and Newton. In Blumenbach's opinion he was one of the enlightenment's greatest thinkers in both versatility and depth. He contributed significantly to developments in medicine, physiology, botany, pharmacology, theology, literature, editing, chronicles, biography, geography, and during his later years in Switzerland jurisprudence and agrarian reform. On the occasion of the 300th anniversary of his birth, important scientific landmarks in his life are described, with special attention to his achievements in the fields of anatomy, physiology, surgery, and experimental research.

  12. Acquired von Willebrand syndrome: von Willebrand factor propeptide to von Willebrand factor antigen ratio predicts remission status

    PubMed Central

    Lee, Adrienne; Sinclair, Gary; Valentine, Karen; James, Paula

    2014-01-01

    We investigated a case of acquired von Willebrand syndrome (AVWS) secondary to a nonneutralizing anti-von Willebrand factor (VWF) antibody associated with an autoimmune disorder. At diagnosis, VWF activity (VWF:Act), antigen (VWF:Ag), multimers, and factor VIII coagulant activity were virtually absent. VWF propeptide (VWFpp) was elevated with an infinitely high VWFpp to VWF:Ag ratio (VWFpp:Ag) consistent with rapid VWF clearance. Immunosuppressive treatment resulted in phenotypic remission 1 with normalization of VWF/factor VIII levels and multimer pattern. However, VWFpp:Ag remained elevated (∼2× normal), consistent with ongoing VWF clearance by the remaining anti-VWF antibody still present by enzyme-linked immunosorbent assay. This suggests that increased VWF secretion was compensating for the incomplete remission state. Relapse occurred when VWFpp:Ag was again infinitely high, with associated decreased VWFpp but unchanged anti-VWF titers; switching the balance to favor VWF clearance over secretion. Complete remission with undetectable anti-VWF occurred only when VWFpp:Ag was normal. This case of relapsing-remitting AVWS demonstrates the use of VWFpp:Ag for predicting remission status. PMID:24951428

  13. Rare liver tumor: symptomatic giant von Meyenburg complex

    PubMed Central

    Singh, Yardesh; Cawich, Shamir O.; Ramjit, Chunilal; Naraynsingh, Vijay

    2016-01-01

    von Meyenburg complexes are hamartomas that arise from intra-hepatic bile ducts. Symptomatic lesions are uncommon and giant lesions are exceedingly rare. When encountered, they should be excised because there are reports of malignant change in large, symptomatic lesions. We report a case of a symptomatic giant von Meyenburg complex. PMID:28068648

  14. Victor or Villain? Wernher von Braun and the Space Race

    ERIC Educational Resources Information Center

    O'Brien, Jason L.; Sears, Christine E.

    2011-01-01

    Set during the Cold War and space race, this historical role-play focuses on Wernher von Braun's involvement in and culpability for the use of slave laborers to produce V-2 rockets for Nazi Germany. Students will grapple with two central questions. Should von Braun have been allowed to emigrate to the United States given his affiliation with the…

  15. Victor or Villain? Wernher von Braun and the Space Race

    ERIC Educational Resources Information Center

    O'Brien, Jason L.; Sears, Christine E.

    2011-01-01

    Set during the Cold War and space race, this historical role-play focuses on Wernher von Braun's involvement in and culpability for the use of slave laborers to produce V-2 rockets for Nazi Germany. Students will grapple with two central questions. Should von Braun have been allowed to emigrate to the United States given his affiliation with the…

  16. A New Generalization of von Neumann Relative Entropy

    NASA Astrophysics Data System (ADS)

    Li, Jing; Cao, Huaixin

    2017-08-01

    In quantum information, von Neumann relative entropy has a great applications and operational interpretations in diverse fields, and von Neumann entropy is an important tool for describing the uncertainty of a quantum state. In this paper, we generalize the classical von Neumann relative entropy S(ρ||σ) and von Neumann entropy S(ρ) to f-von Neumann relative entropy \\widetilde {S}f(ρ ||σ ) and f-von Neumann entropy \\widetilde {S}f(ρ ) induced by a logarithm-like function f, respectively, and explore their properties. We prove that \\widetilde {S}f(ρ ||σ ) is nonnegative and then prove that \\widetilde {S}f(ρ ) has nonnegativity, boundedness, concavity, subadditivity and so on. Later, we show the stability and continuity of the \\widetilde {S}f(ρ ) with respect to the trace distance. In the case that f(x) = -log x, the resulted entropies reduce the classical von Neumann relative entropy and von Neumann entropy, respectively. This means that our results extend the usual results to a more general setting and then have some potential applications in quantum information.

  17. Group Theoretical Interpretation of von Neumann's Theorem on Composite Systems.

    ERIC Educational Resources Information Center

    Bergia, S.; And Others

    1979-01-01

    Shows that von Neumann's mathematical theorem on composite systems acquires a transparent physical meaning with reference to a suitable physical example; a composite system in a state of definite angular momentum. Gives an outline of the theorem, and the results are restated in Dirac's notation, thus generalizing von Neumann's results which were…

  18. Virtualized Optical Network (VON) for Future Internet and Applications

    NASA Astrophysics Data System (ADS)

    Jinno, Masahiko; Tsukishima, Yukio; Takara, Hidehiko; Kozicki, Bartlomiej; Sone, Yoshiaki; Sakano, Toshikazu

    A virtualized optical network (VON) is proposed as a key to implementing increased agility and flexibility into the future Internet and applications by providing any-to-any connectivity with the appropriate optical bandwidth at the appropriate time. The VON is enabled by introducing optical transparentization and optical fine granular grooming based on optical orthogonal frequency division multiplexing.

  19. Group Theoretical Interpretation of von Neumann's Theorem on Composite Systems.

    ERIC Educational Resources Information Center

    Bergia, S.; And Others

    1979-01-01

    Shows that von Neumann's mathematical theorem on composite systems acquires a transparent physical meaning with reference to a suitable physical example; a composite system in a state of definite angular momentum. Gives an outline of the theorem, and the results are restated in Dirac's notation, thus generalizing von Neumann's results which were…

  20. Dr. von Braun Tries Out the Neutral Buoyancy Simulator (NBS)

    NASA Technical Reports Server (NTRS)

    1967-01-01

    Marshall Space Flight Center (MSFC) Director, Dr. von Braun, submerges after spending some time under water in the MSFC Neutral Buoyancy Simulator (NBS). Weighted to a neutrally buoyant condition, Dr. von Braun was able to perform tasks underwater which simulated weightless conditions found in space.

  1. Dr. von Braun Tries Out the Neutral Buoyancy Simulator (NBS)

    NASA Technical Reports Server (NTRS)

    1967-01-01

    Astronaut L. Gordon Cooper checks the neck ring of a space suit worn by Marshall Space Flight Center (MSFC) Director, Dr. von Braun before he submerges into the water of the MSFC Neutral Buoyancy Simulator (NBS). Wearing a pressurized suit and weighted to a neutrally buoyant condition, Dr. von Braun was able to perform tasks underwater which simulated weightless conditions found in space.

  2. Dr. von Braun Tries Out the Neutral Buoyancy Simulator (NBS)

    NASA Technical Reports Server (NTRS)

    1967-01-01

    Marshall Space Flight Center (MSFC) Director, Dr. von Braun, is shown leaving the suiting-up van wearing a pressure suit prepared for a tryout in the MSFC Neutral Buoyancy Simulator (NBS). Weighted to a neutrally buoyant condition, Dr. von Braun was able to perform tasks underwater which simulated weightless conditions found in space.

  3. Interaktive Visualisierung von Abständen und Ausdehnungen anatomischer Strukturen für die Interventionsplanung

    NASA Astrophysics Data System (ADS)

    Rössling, Ivo; Cyrus, Christian; Dornheim, Lars; Hahn, Peter; Preim, Bernhard; Boehm, Andreas

    Im Rahmen der Interventionsplanung muss der Chirurg therapierelevante Entscheidungen auf Basis räumlicher Relationen anatomischer Strukturen treffen. Interaktive 3D-Visualisierungen unterstützen diesen Prozess qualitativ. Quantitative Fragestellungen (Tumorausdehnung, Infiltrationstiefe, etc.) erfordern die Integration einer Bemaßung, deren Nutzen wesentlich von einer geeigneten Darstellung abhängt. In dieser Arbeit haben wir allgemeine Kriterien für die Eignung von Visualisierungen von Bemaßungen in interaktiven 3D-Szenen erarbeitet. Daran orientierend haben wir verschiedene Varianten der Darstellung von Abständen und Ausdehnungen anatomischer Strukturen betrachtet und ihr Erscheinungsbild hierzu zweckmäßig parametrisiert. Die Ausprägungen dieser Darstellungsparameter wurden in einer Studie auf ihre visuellen Wirkung hin an Chirurgen evaluiert. Es zeigte sich, dass die befragten Mediziner höchsten Wert auf Kohärenz und klare Zuordnung der Bemaßung setzten und überraschenderweise dafür sogar Abstriche in der direkten Lesbarkeit in Kauf nahmen.

  4. Multimeric analysis of von Willebrand factor in megakaryocytes.

    PubMed

    Kupinski, J M; Miller, J L

    1985-06-15

    Von Willebrand factor (vWF) is a glycoprotein that appears to play a major role in subserving the adhesion of platelets to subendothelium during hemostasis. Endothelial cells have been shown capable of synthesizing and releasing this large, multimeric glycoprotein that normally circulates in the plasma in association with the factor VIII coagulant molecule. Megakaryocytes, the precursor cells of blood platelets, also appear to possess vWF biosynthetic capacity, since cultured guinea pig megakaryocytes have been shown to produce a polypeptide precipitable by antibody to vWF. We now report a study of the multimeric structure of vWF in the megakaryocyte, as well as a quantitative comparison of megakaryocyte vWF with that of platelets and plasma in the guinea pig. Multimeric analysis on SDS agarose gels employing 125I-emu anti-human vWF revealed striking homology between human and guinea pig vWF. Platelets and megakaryocytes from the same guinea pigs contained vWF of highly comparable multimeric composition. Moreover, megakaryocytes and platelets both contained a subset of very high molecular weight multimers not present in plasma. Quantitation of vWF in megakaryocytes and platelets was achieved with a radioimmunoassay performed on detergent (NP-40) lysates of washed cells. These measurements showed that megakaryocytes and platelets contain 0.079 and 0.069 U of vWF per mg protein, respectively. The results of these studies suggest that megakaryocytes represent the primary, if in fact not sole, source of platelet vWF.

  5. Wernher von Braun and Saturn IB on Launch Pad

    NASA Technical Reports Server (NTRS)

    1968-01-01

    Dr. Wernher von Braun stands in front of a Saturn IB launch vehicle at Kennedy Space Flight Center. Dr. von Braun led a team of German rocket scientists, called the Rocket Team, to the United States, first to Fort Bliss/White Sands, later being transferred to the Army Ballistic Missile Agency at Redstone Arsenal in Huntsville, Alabama. They were further transferred to the newly established NASA/Marshall Space Flight Center (MSFC) in Huntsville, Alabama in 1960, and Dr. von Braun became the first Center Director. Under von Braun's direction, MSFC developed the Mercury-Redstone, which put the first American in space; and later the Saturn rockets, Saturn I, Saturn IB, and Saturn V. The Saturn V launch vehicle put the first human on the surface of the Moon, and a modified Saturn V vehicle placed Skylab, the first United States' experimental space station, into Earth orbit. Dr. von Braun was MSFC Director from July 1960 to February 1970.

  6. Von Neumann's quantization of general relativity

    NASA Astrophysics Data System (ADS)

    Arbuzov, A. B.; Cherny, A. Yu.; Cirilo-Lombardo, D. J.; Nazmitdinov, R. G.; Han, Nguyen Suan; Pavlov, A. E.; Pervushin, V. N.; Zakharov, A. F.

    2017-05-01

    Von Neumann's procedure is applied to quantizing general relativity. Initial data for dynamical variables in the Planck epoch, where the Hubble parameter value coincided with the Planck mass are quantized. These initial data are defined in terms of the Fock orthogonal simplex in the tangent Minkowski spacetime and the Dirac conformal interval. The Einstein cosmological principle is used to average the logarithm of the determinant of the spatial metric over the spatial volume of the visible Universe. The splitting of general coordinate transformations into diffeomorphisms and transformations of the initial data is introduced. In accordance with von Neumann's procedure, the vacuum state is treated is a quantum ensemble that is degenerate in quantum numbers of nonvacuum states. The distribution of the vacuum state leads to the Casimir effect in gravidynamics in just the same way as in electrodynamics. The generating functional for perturbation theory in gravidynamics is found by solving the quantum energy constraint. The applicability range of gravidynamics is discussed along with the possibility of employing this theory to interpret modern observational data.

  7. Molecular diagnosis of von Willebrand disease.

    PubMed

    Baronciani, L; Goodeve, A; Peyvandi, F

    2017-03-01

    The role of molecular characterization in the diagnosis of von Willebrand disease (VWD) is not essential if the patients have been extensively investigated using phenotypic analysis. On the other hand, if some of these phenotype assays are not available, the identification of the mutation causing the disease could be crucial for an accurate diagnosis. Nevertheless, there are several reasons for performing molecular analysis in patients phenotypically well characterized, e.g. to identify the mutation causing VWD can be useful for patients and their family members when prenatal diagnosis is required (type 3 or severe type 2). In this manuscript, we report the techniques used for the molecular characterization of suspected VWD patients. We describe the use of online von Willebrand factor database and online single nucleotide variation databases, the former to verify whether a candidate mutation has been previously identified in other VWD patients and the latter to ascertain whether a putative mutation has been reported earlier in healthy individuals. We listed the available in silico analysis tools, to determine the predicted pathogenicity of a sequence variant and to establish its possible negative effect on the normal splicing process. We also report the strategy that can be used to identify VWD type 2 patients' mutations in subjects who have been fully characterized using the phenotype assays.

  8. Report on von Willebrand Disease in Malaysia

    PubMed Central

    Periayah, Mercy Halleluyah; Halim, Ahmad Sukari; Saad, Arman Zaharil Mat; Yaacob, Nik Soriani; Karim, Faraizah Abdul

    2016-01-01

    BACKGROUND: Von Willebrand disease (vWD) is an inherited hemostatic disorder that affects the hemostasis pathway. The worldwide prevalence of vWD is estimated to be 1% of the general population but only 0.002% in Malaysia. AIM: Our present paper has been written to disclose the statistical counts on the number of vWD cases reported from 2011 to 2013. MATERIAL AND METHODS: This article is based on sociodemographic data, diagnoses and laboratory findings of vWD in Malaysia. A total of 92 patients were reported to have vWD in Malaysia from 2011 to 2013. RESULTS: Sociodemographic-analysis revealed that 60% were females, 63% were of the Malay ethnicity, 41.3% were in the 19-44 year old age group and 15.2% were from Sabah, with the East region having the highest registered number of vWD cases. In Malaysia, most patients are predominately affected by vWD type 1 (77.2%). Factor 8, von Willebrand factor: Antigen and vWF: Collagen-Binding was the strongest determinants in the laboratory profiles of vWD. CONCLUSION: This report has been done with great interest to provide an immense contribution from Malaysia, by revealing the statistical counts on vWD from 2011-2013. PMID:27275342

  9. Approximate von Neumann entropy for directed graphs.

    PubMed

    Ye, Cheng; Wilson, Richard C; Comin, César H; Costa, Luciano da F; Hancock, Edwin R

    2014-05-01

    In this paper, we develop an entropy measure for assessing the structural complexity of directed graphs. Although there are many existing alternative measures for quantifying the structural properties of undirected graphs, there are relatively few corresponding measures for directed graphs. To fill this gap in the literature, we explore an alternative technique that is applicable to directed graphs. We commence by using Chung's generalization of the Laplacian of a directed graph to extend the computation of von Neumann entropy from undirected to directed graphs. We provide a simplified form of the entropy which can be expressed in terms of simple node in-degree and out-degree statistics. Moreover, we find approximate forms of the von Neumann entropy that apply to both weakly and strongly directed graphs, and that can be used to characterize network structure. We illustrate the usefulness of these simplified entropy forms defined in this paper on both artificial and real-world data sets, including structures from protein databases and high energy physics theory citation networks.

  10. New mutations in exon 28 of the von Willebrand factor gene detected in patients with different types of von Willebrand's disease.

    PubMed

    Casaña, P; Martínez, F; Haya, S; Tavares, A; Aznar, J A

    2001-04-01

    von Willebrand's disease (vWD), the most common hereditary bleeding disorder in humans, is caused by qualitative and/or quantitative deficiencies of von Willebrand factor, and can manifest itself under several different phenotypes. Most of the molecular defects have been detected in qualitative variants involving exon 28 of the vWF gene. Patients from four unrelated families with different types of vWD were included in the mutation screening of this region. The whole exon 28 was analyzed in three gene specific fragments, two of them comprising the region involved in the platelet glycoprotein Ib vWF interaction. The search for mutations was carried out by single-stranded conformation polymorphism analysis. The mutations were then identified by automatic sequencing of the anomalous electrophoretic pattern samples. The following candidate mutations were detected. The 3941T-->A transversion, which predicts the amino acid change V1314D, was detected in a sporadic patient with type 2B vWD and severe thrombocytopenia. The 4309G-->A transition, resulting in the amino acid substitution A1437T, was identified in four patients classified as having type 2M vWD. Six unclassified patients from another family carry the 4135C-->T mutation, which gives rise to a cysteine instead of the normal arginine (R1379C) that segregates with the phenotype. The amino acid change C1227R, predicted by the mutation 4135C-->T, was identified as a compound heterozygote in a patient with moderately severe type 1 vWD. None of these mutations had been described previously. These findings confirm the importance already given to this region for the correct function of von Willebrand factor since the mutations detected, which affect the D3 and A1 domains, could give rise to different variants of the disease.

  11. Quantitative research.

    PubMed

    Watson, Roger

    2015-04-01

    This article describes the basic tenets of quantitative research. The concepts of dependent and independent variables are addressed and the concept of measurement and its associated issues, such as error, reliability and validity, are explored. Experiments and surveys – the principal research designs in quantitative research – are described and key features explained. The importance of the double-blind randomised controlled trial is emphasised, alongside the importance of longitudinal surveys, as opposed to cross-sectional surveys. Essential features of data storage are covered, with an emphasis on safe, anonymous storage. Finally, the article explores the analysis of quantitative data, considering what may be analysed and the main uses of statistics in analysis.

  12. Quantitative Habitability

    NASA Astrophysics Data System (ADS)

    Shock, Everett L.; Holland, Melanie E.

    2007-12-01

    A framework is proposed for a quantitative approach to studying habitability. Considerations of environmental supply and organismal demand of energy lead to the conclusions that power units are most appropriate and that the units for habitability become watts per organism. Extreme and plush environments are revealed to be on a habitability continuum, and extreme environments can be quantified as those where power supply only barely exceeds demand. Strategies for laboratory and field experiments are outlined that would quantify power supplies, power demands, and habitability. An example involving a comparison of various metabolisms pursued by halophiles is shown to be well on the way to a quantitative habitability analysis.

  13. QUANTITATIVE MORPHOLOGY

    EPA Science Inventory

    Abstract: In toxicology, the role of quantitative assessment of brain morphology can be understood in the context of two types of treatment-related alterations. One type of alteration is specifically associated with treatment and is not observed in control animals. Measurement ...

  14. QUANTITATIVE MORPHOLOGY

    EPA Science Inventory

    Abstract: In toxicology, the role of quantitative assessment of brain morphology can be understood in the context of two types of treatment-related alterations. One type of alteration is specifically associated with treatment and is not observed in control animals. Measurement ...

  15. Two novel anti-von Willebrand factor monoclonal antibodies.

    PubMed

    Spadafora-Ferreira, M; Lopes, A A; Coelho, V; Guilherme, L; Kalil, J

    2000-01-15

    Von Willebrand Factor is a multimer produced by endothelial cells and megakaryocytes, being stored in intracellular organelles, such as the Weibel-Palade bodies and alpha-granules in endothelial cells and platelets, respectively. This molecule acts as a carrier protein for factor VIIIc, involved in the intrinsic pathway of blood coagulation maintaining its stability in circulation. Von Willebrand Factor also plays an important role in platelet aggregation and adhesion to injured vessel wall. It interacts with platelets through two distinct glycoproteins, GPIb and GPIIb/IIIa. We raised two monoclonal antibodies, ECA-3 and ECA-4, against human umbilical vascular endothelial cells that recognize and immunoprecipitate von Willebrand Factor. Interestingly, ECA-4 monoclonal antibody is able to completely inhibit platelet agglutination induced by ristocetin, suggesting that it binds to von Willebrand Factor close to platelet GPIb binding site. The use of monoclonal antibodies to identify von Willebrand Factor binding regions to factor VIII or platelets has been reported by others. In pulmonary hypertension, abnormalities have been detected on the multimeric structure of the molecule as well as on its proteolytic fragments, by using monoclonal antibodies. Moreover, monoclonal antibodies raised against specific regions of von Willebrand Factor molecule may allow studies of functional abnormalities of this protein in inherited and acquired disorders like subtypes of von Willebrand's disease.

  16. Interactions of von Willebrand factor and ADAMTS13 in von Willebrand disease and thrombotic thrombocytopenic purpura.

    PubMed

    Budde, U; Schneppenheim, R

    2014-01-01

    The function of von Willebrand factor (VWF), a huge multimeric protein and a key factor in platelet dependent primary haemostasis, is regulated by its specific protease ADAMTS13. The ADAMTS13 dependent degradation of VWF to its proteolytic fragments can be visualized as a characteristic so-called triplet structure of individual VWF oligomers by multimer analysis. Lack of VWF high molecular weight multimers (VWF-HMWM) or their pathologically enhanced degradation underlies a particular type of von Willebrand disease, VWD type 2A with a significant bleeding tendency, and may also be observed in acquired von Willebrand syndrome due to cardiovascular disease. In these conditions multimer analysis is an obligatory and powerful tool for diagnosis of VWD. The opposite condition, the persistence of ultralarge VWF (UL-VWF) multimers may cause the microangiopathic life-threatening disorder thrombotic thrombocytopenic purpura (TTP). During the course of active TTP, UL-VWF is consumed in the hyaline thrombi formed in the microvasculature which will ultimately result in the loss of UL-VWF and VWF-HMWM. Therefore, VWF multimer analysis is not a valid tool to diagnose TTP in the active phase of disease but may be helpful for the diagnosis of TTP patients in remission.

  17. [Von Willebrand disease in the Netherlands: the WiN study].

    PubMed

    Sanders, Yvonne V; de Wee, Eva M; Meijer, Karina; Eikenboom, J; van der Bom, Jeroen G; Fijnvandraat, C J Karin; Laros-van Gorkom, Britta A P; Cnossen, Marjon H; Mauser-Bunschoten, Evelien P; Leebeek, Frank W G

    2014-01-01

    Von Willebrand disease is the most common inherited bleeding disorder and is characterised by mucocutaneous bleeding. Von Willebrand disease is caused by reduced levels or reduced function of von Willebrand factor. Depending on the cause, von Willebrand disease is distinguished into various types with their own characteristics and treatment options. The frequency and severity of bleeding in patients with von Willebrand disease is strongly determined by von Willebrand factor levels, factor VIII levels and the type of von Willebrand disease. Eighty-five percent of all adult females with von Willebrand disease reports menorrhagia. A high percentage have postpartum excessive blood loss (37% of all deliveries). The quality of life is reduced in patients with von Willebrand disease. Patients with von Willebrand disease have a reduced risk of arterial thrombosis such as a myocardial or cerebral infarction.

  18. Quantenphysik Interferometrie von C70-Molekülen

    NASA Astrophysics Data System (ADS)

    Ziegler, Thomas

    2002-05-01

    Interferenzversuche mit Neutronen und schweren Atomen stellen kein großes Problem mehr dar, selbst die Welleneigenschaften von C60-und C70-Molekülen wurden bereits nachgewiesen. Allerdings stößt man bei der Realisation immer feinerer Gitter mit Gitterkonstanten von etwa 100 nm im Fall dieser Moleküle auf technische Probleme. Wissenschaftlern der Universität Wien ist es jüngst gelungen, ein so genanntes Talbot-Lau-Interferometer zu realisieren und die Welleneigenschaften von C70 mit einer bislang unerreichten Qualität nachzuweisen [1].

  19. Valence bond and von Neumann entanglement entropy in Heisenberg ladders.

    PubMed

    Kallin, Ann B; González, Iván; Hastings, Matthew B; Melko, Roger G

    2009-09-11

    We present a direct comparison of the recently proposed valence bond entanglement entropy and the von Neumann entanglement entropy on spin-1/2 Heisenberg systems using quantum Monte Carlo and density-matrix renormalization group simulations. For one-dimensional chains we show that the valence bond entropy can be either less or greater than the von Neumann entropy; hence, it cannot provide a bound on the latter. On ladder geometries, simulations with up to seven legs are sufficient to indicate that the von Neumann entropy in two dimensions obeys an area law, even though the valence bond entanglement entropy has a multiplicative logarithmic correction.

  20. A von Bertalanffy growth model with a seasonally varying coefficient

    USGS Publications Warehouse

    Cloern, James E.; Nichols, Frederic H.

    1978-01-01

    The von Bertalanffy model of body growth is inappropriate for organisms whose growth is restricted to a seasonal period because it assumes that growth rate is invariant with time. Incorporation of a time-varying coefficient significantly improves the capability of the von Bertalanffy equation to describe changing body size of both the bivalve mollusc Macoma balthicain San Francisco Bay and the flathead sole, Hippoglossoides elassodon, in Washington state. This simple modification of the von Bertalanffy model should offer improved predictions of body growth for a variety of other aquatic animals.

  1. Alexander von Humboldt and the concept of animal electricity.

    PubMed

    Kettenmann, H

    1997-06-01

    More than two hundred years ago, Alexander von Humboldt helped to establish Galvani's view that muscle and nerve tissue are electrically excitable. His 1797 publication was a landmark for establishing the concept of animal electricity. Almost half a century later, von Humboldt became the mentor of the young du Bois-Reymond. With the help of von Humboldt's promotion, du Bois-Reymond demonstrated convincingly that animal tissue has the intrinsic capacity to generate electrical activity, and thus laid the ground for modern electrophysiology.

  2. Johann Philipp von Wurzelbau (1651-1725)

    NASA Astrophysics Data System (ADS)

    Gaab, Hans

    During the turn of the 17th to the 18th century, Johann Philipp von Wurzelbau was the best-known astronomer in Nuremberg. He was a trained merchant, who busied himself in his free hours with astronomy. In the 1680s he became known for his accurate observations of lunar and solar eclipses. At the end of the 1680s he left his trade, and from 1691, he was completely occupied with astronomy. To that end, he constructed a small octagonal observing tower on the roof of his house at Spitzenberg 4. He took the measurement of the solar path and determined the geographical coordinates of Nuremberg. The calendar reform also played a major role in his life.

  3. Hermann von Helmholtz and his students

    NASA Astrophysics Data System (ADS)

    Mulligan, Joseph F.

    1989-01-01

    During the years 1871-1888, when Hermann von Helmholtz was professor of physics at the University of Berlin, physicists from all over the world flocked to Berlin to study and do research with him. Among these were the German physicists Max Planck, Heinrich Kayser, Eugen Goldstein, Wilhelm Wien, and Heinrich Hertz, and Americans Henry Rowland, A. A. Michelson, and Michael Pupin. Examples of Helmholtz's scientific and personal interactions with these students and research associates show why he is justly considered the outstanding physics mentor of the 19th century. Both his ideas and his students played a major role in the development of physics in the late 19th and early 20th centuries.

  4. Leichte Neucodierung von Selenocystein in der Natur

    PubMed Central

    Mukai, Takahito; Englert, Markus; Tripp, H. James; Miller, Corwin; Ivanova, Natalia N.; Rubin, Edward M.; Kyrpides, Nikos C.

    2016-01-01

    Selenocystein (Sec oder U) wird durch Neuzuordnung des Stopp-Codons UGA durch einen Sec-spezifischen Elongationsfaktor und eine charakteristische RNA-Struktur codiert. Um mögliche Codonvariationen zu finden, analysierten wir 6.4 Billionen Basenpaare metagenomischer Daten sowie 24903 mikrobielle Genome für tRNASec-Spezies. UGA ist erwartungsgemäβ das vorherrschende Codon für Sec, allerdings finden wir auch tRNASec-Spezies, die die Stopp-Codons UAG und UAA erkennen, sowie weitere zehn Sense-Codons. Die Synthese von Selenoproteinen durch UAG in Geodermatophilus und Blastococcus sowie durch das Cys-Codon UGA in Aeromonas salmonicida konnte durch metabolische Markierung mit 75Se oder Massenspektrometrie bestätigt werden. Weitere tRNASec-Spezies mit verschiedenen Anticodons ermöglichten es Escherichia coli, die aktive Form des Selenoproteins Formiatdehydrogenase H zu synthetisieren. Der genetische Code ist damit bedeutend flexibler, als bisher angenommen. PMID:27440945

  5. Von Economo neurons in the elephant brain.

    PubMed

    Hakeem, Atiya Y; Sherwood, Chet C; Bonar, Christopher J; Butti, Camilla; Hof, Patrick R; Allman, John M

    2009-02-01

    Von Economo neurons (VENs), previously found in humans, all of the great ape species, and four cetacean species, are also present in African and Indian elephants. The VENs in the elephant are primarily found in similar locations to those in the other species. They are most abundant in the frontoinsular cortex (area FI) and are also present at lower density in the anterior cingulate cortex. Additionally, they are found in a dorsolateral prefrontal area and less abundantly in the region of the frontal pole. The VEN morphology appears to have arisen independently in hominids, cetaceans, and elephants, and may reflect a specialization for the rapid transmission of crucial social information in very large brains.

  6. Johann von Lamont: A Pioneer in Geomagnetism

    NASA Astrophysics Data System (ADS)

    Soffel, Heinrich

    2006-06-01

    The 200th birthday of John Lamont (1805-1879, Figure 1), a pioneer in the study of geomagnetism, was marked on 13 December 2005. Lamont founded the Munich Geomagnetic Observatory in 1840 and was a member of the group of scientists including Carl Friedrich Gauss, Alexander von Humboldt, Eduard Sabine, Jonas Angstrøm, Humphret Lloyd, Adolf Kupffer, Karl Kreil, and Adolphe Quetelet who composed the Göttingen Magnetic Union. They organized an international network of geomagnetic observatories [Barraclough et al., 1992]. The present knowledge of the geomagnetic field and its secular variation is largely based on the data collected by the global network of geomagnetic observatories during the last 170 years. Lamont's talents and his dedication and enthusiasm for discovery are reflected in the depth and scope of his contributions to a broad variety of natural sciences such as astronomy, meteorology, geomagnetism, and geodesy. However, this article just touches on his merits in geomagnetism.

  7. Adenotonsillectomy in children with von Willebrand's disease: how and when. A case report with review of the literature.

    PubMed

    Berlucchi, Marco; Tomenzoli, Davide; Nicolai, Piero; Lusk, Rodney P

    2002-09-24

    The presence of coagulation pathology in children who are candidates for adenotonsillectomy (AT) is a challenge to the otolaryngologist. von Willebrand's disease (vWD) is the most common hereditary coagulopathy and is due to a quantitative and/or qualitative deficiency of von Willebrand's factor (vWF). In recent years, the administration of 1-deamino-8-D-arginine vasopressin (DDAVP) has been recommended as coadjuvant therapy for surgical procedure. This synthetic hormone promotes the release of vWF and factor VIII from endothelial cells. In this report, the authors describe the history of a child with vWD undergoing successful AT after administration of DDAVP. Furthermore, a review of the literature with particular emphasis on the use of DDAVP is made.

  8. Quantitative glycomics.

    PubMed

    Orlando, Ron

    2010-01-01

    The ability to quantitatively determine changes is an essential component of comparative glycomics. Multiple strategies are available by which this can be accomplished. These include label-free approaches and strategies where an isotopic label is incorporated into the glycans prior to analysis. The focus of this chapter is to describe each of these approaches while providing insight into their strengths and weaknesses, so that glycomic investigators can make an educated choice of the strategy that is best suited for their particular application.

  9. 7. Historic American Buildings Survey, Charles Von Urban, Photographer June ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. Historic American Buildings Survey, Charles Von Urban, Photographer June 23, 1936, INTERIOR-PARLOR SHOWING FIREPLACE, WINDOWN TRIM, AND CORNICE. - George Fordham House, 329 Cherry Street, New York County, NY

  10. Fletcher and von Braun at Apollo 15 launch

    NASA Technical Reports Server (NTRS)

    1971-01-01

    Recently appointed NASA Administrator Dr. James C. Fletcher, left, and Dr. Wernher von Braun, Deputy Associate Administrator for Planning, monitor Apollo 15 prelaunch activities in Firing Room 1 of the Launch Control Center and the Kennedy Space Center, Florida.

  11. Dr. von Braun at the Manufacturing and Engineering Laboratory

    NASA Technical Reports Server (NTRS)

    1967-01-01

    Dr. von Braun, Director of the Marshall Space Flight Center, listens attentively to a briefing on the metal forming techniques by Dr. Mathias Siebel of the Manufacturing and Engineering Laboratory at MSFC on October 17, 1967.

  12. 33. HISTORIC VIEW OF WERNHER VON BRAUN LOOKS THROUGH THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    33. HISTORIC VIEW OF WERNHER VON BRAUN LOOKS THROUGH THE PERISCOPE FROM THE CONTROL ROOM AT TEST STAND NO. 1, PEENEMUENDE. - Marshall Space Flight Center, Redstone Rocket (Missile) Test Stand, Dodd Road, Huntsville, Madison County, AL

  13. Dr. Wernher Von Braun examines a ruby crystal.

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Dr. Wernher Von Braun (right), director of the Marshall Space Flight Center, and Dr. Eberhard Rees (left), deputy director, technical, examine a ruby crystal used in laser experiments in the Marshall Center's Space Sciences Laboratory.

  14. A proof of von Neumann's postulate in Quantum Mechanics

    SciTech Connect

    Conte, Elio

    2010-05-04

    A Clifford algebraic analysis is explained. It gives proof of von Neumann's postulate on quantum measurement. It is of basic significance to explain the problem of quantum wave function reduction in quantum mechanics.

  15. Alexander von Humboldt and the Origins of Landscape Archaeology.

    ERIC Educational Resources Information Center

    Mathewson, Kent

    1986-01-01

    Reviews the life, theories, and influence of Alexander von Humboldt, the early nineteenth century founder of modern geography. Maintains that Humboldt's novel approaches to the study of landscape antiquities have value for contemporary students in cultural and historical geography. (JDH)

  16. Can a Quantum Computer Run the von Neumann Architecture?

    NASA Astrophysics Data System (ADS)

    Hines, P.

    At the core of nearly every modern computer is a central processing unit running the von Neumann architecture. This computer architecture gives computationally universal machines, and non-trivial control structures arise naturally, leading to high-level programming constructs.

  17. Physik gestern und heute Von der Metallstange zum Hochenergielaser

    NASA Astrophysics Data System (ADS)

    Heering, Peter

    2002-05-01

    Im Mai 1752 wurde in Marly bei Paris auf Anregung des amerikanischen Forschers und Politikers Benjamin Franklin erstmals die elektrische Natur des Blitzes nachgewiesen. Damals beschrieb Franklin auch eine technische Vorrichtung, die als Schutz von Gebäuden vor Blitzschlägen dienen sollte: den Blitzableiter. Diese aus heutiger Sicht scheinbar triviale Vorrichtung wurde aber keineswegs unmittelbar akzeptiert. Und bis heute ist die Forschung zum Schutz von Einrichtungen vor Blitzschlägen nicht abgeschlossen.

  18. Wernher von Braun with German Officers and Others

    NASA Technical Reports Server (NTRS)

    1942-01-01

    General Erich Fellgiebel, head of the German Army Information Service during World War II, congratulates members of the von Braun rocket team from Peenemunde for their October 3, 1942 A4 flight. Pictured front center is General Erich Fellgiebel. Shaking hands are General Walter Dornberger (left) and General Janssen, commanding officer of Peenemuende with Rudolph Hermarn to their right. Picture left to right in the back row are Wernher von Braun, Captain Stoelzel, Luftwaffe, and Dr. Gerhard Reisig.

  19. Dr. von Braun and His Family Being Honored

    NASA Technical Reports Server (NTRS)

    1970-01-01

    Marshall Space Flight Center (MSFC) Director Dr. von Braun and his family were honored with a series of events prior to his relocation to Washington, D.C., where he was assigned duties at NASA Headquarters as Deputy Associate Administrator for Plarning. (Left to right) Dr. von Braun, wife Maria, son Peter, and daughter Margrit are shown on the steps of the Madison County Courthouse, Huntsville, Alabama.

  20. Management of Type 2B von Willebrand Disease during Pregnancy.

    PubMed

    McLaughlin, David; Kerr, Ron

    2017-01-01

    Type 2B von Willebrand disease is a rare bleeding condition resulting in thrombocytopenia and a reduction in large VWF multimers. It usually has an autosomal dominant pattern of inheritance. We report the management of a patient with type 2B von Willebrand disease, whose diagnosis was confirmed by demonstration of a R1306W mutation, through her first pregnancy. The patient's von Willebrand factor (VWF) antigen and VWF ristocetin cofactor levels rose throughout pregnancy, with an associated drop in the platelet count. The patient was successfully managed through labour to a surgical delivery with VWF concentrate, platelet transfusions and tranexamic acid. The patient delivered a male baby who was found to have inherited type 2B von Willebrand disease and had a significant cephalhaematoma at delivery. The baby was managed with VWF concentrate and platelet transfusions and made a full recovery. There is a lack of evidence to guide the best management of pregnant patients with type 2B von Willebrand disease. We adopted a pragmatic management plan, in keeping with other published case reports. To the best of our knowledge, this is the first case report in which the child was found to have inherited type 2B von Willebrand disease and encountered bleeding problems, making this case unique amongst the published literature.

  1. A constrained von Mises distribution to describe fiber organization in thin soft tissues.

    PubMed

    Gouget, Cecile L M; Girard, Michael J; Ethier, C Ross

    2012-03-01

    The semi-circular von Mises distribution is widely used to describe the unimodal planar organization of fibers in thin soft tissues. However, it cannot accurately describe the isotropic subpopulation of fibers present in such tissues, and therefore an improved mathematical description is needed. We present a modified distribution, formed as a weighted mixture of the semi-circular uniform distribution and the semi-circular von Mises distribution. It is described by three parameters: β, which weights the contribution from each mixture component; k, the fiber concentration factor; and θ ( p ), the preferred fiber orientation. This distribution was used to fit data obtained by small-angle light scattering experiments from various thin soft tissues. Initial use showed that satisfactory fits of fiber distributions could be obtained (error generally < 1%), but at the cost of non-physically meaningful values of k and β. To address this issue, an empirical constraint between the parameters k and β was introduced, resulting in a constrained 2-parameter fiber distribution. Compared to the 3-parameter distribution, the constrained 2-parameter distribution fits experimental data well (error generally < 2%) and had the advantage of producing physically meaningful parameter values. In addition, the constrained 2-parameter approach was more robust to experimental noise. The constrained 2-parameter fiber distribution can replace the semi-circular von Mises distribution to describe unimodal planar organization of fibers in thin soft tissues. Inclusion of such a function in constitutive models for finite element simulations should provide better quantitative estimates of soft tissue biomechanics under normal and pathological conditions.

  2. [Type 2N von Willebrand disease (Normandy)].

    PubMed

    Morales-De la Vega, Alejandro; Reyes-Maldonado, Elba; Martínez-Murillo, Carlos; Quintana-González, Sandra

    2008-01-01

    the results of the laboratory test for 2N von Willebrand disease (2N vWD) are indistinguishable from those of light or moderate haemophilia A, until the technique that evaluates the operation of the vWF: FVIII binding is performed. to determine the prevalence of type 2N vWD in patients diagnosed with light or moderate haemophilia A and type 1 vWD. twelve healthy donors and twenty-five patients diagnosed with haemophilia A (a carrier) and five suspected of type 1 vWD were included in the study. The common tests of haemostasis for this condition plus the technique of the relationship of the vWF: FVIII recombinant (F VIIIr) binding was performed. the laboratory results of the 30 patients were concordant with the previous diagnosis. However, three with a previous diagnosis of haemophilia A demonstrated a rate of relationship of the vWF: F VIIIr binding lower than the reference interval obtained from the healthy donors, which means it corresponds to 2N vWD. the screening method of 2N vWD employed in this study allowed to identify for first time in Mexico, the first cases of this variant with a prevalence of 10%. In our country, this method will allow to establishing accurate diagnosis of 2N vWD and to providing specific treatments.

  3. Quantum control by von Neumann measurements

    NASA Astrophysics Data System (ADS)

    Pechen, Alexander; Il'in, Nikolai; Shuang, Feng; Rabitz, Herschel

    2006-11-01

    A general scheme is presented for controlling quantum systems using evolution driven by nonselective von Neumann measurements, with or without an additional tailored electromagnetic field. As an example, a two-level quantum system controlled by nonselective quantum measurements is considered. The control goal is to find optimal system observables such that consecutive nonselective measurement of these observables transforms the system from a given initial state into a state which maximizes the expected value of a target operator (the objective). A complete analytical solution is found including explicit expressions for the optimal measured observables and for the maximal objective value given any target operator, any initial system density matrix, and any number of measurements. As an illustration, upper bounds on measurement-induced population transfer between the ground and the excited states for any number of measurements are found. The anti-Zeno effect is recovered in the limit of an infinite number of measurements. In this limit the system becomes completely controllable. The results establish the degree of control attainable by a finite number of measurements.

  4. von Willebrand factor expression in osteosarcoma metastasis.

    PubMed

    Eppert, Kolja; Wunder, Jay S; Aneliunas, Vicky; Kandel, Rita; Andrulis, Irene L

    2005-03-01

    A number of genes are implicated in the initiation and progression of osteosarcoma; however, cytogenetic and comparative genomic hybridization studies indicate the involvement of additional unidentified genes. An examination of gene expression profiles in 22 high-grade osteosarcoma tumor specimens from 15 patients (including paired primary and metastatic samples from five patients) indicated that von Willebrand factor (vWF) mRNA expression may increase during tumor progression. vWF, a large glycoprotein previously considered to be expressed exclusively by endothelial cells and megakaryocytes, is involved in platelet aggregation and adhesion to the subendothelial matrix, processes critical to hematogenous tumor cell metastasis to the lung. Analysis of paired primary and metastatic osteosarcoma tumor samples from 10 patients revealed an increase in vWF gene expression in metastases (P=0.005). Immunohistochemistry showed that, in addition to the endothelial cells, vWF protein was also detected in osteosarcoma cells in vivo in 13 of 29 tumor specimens as well as in SAOS2, an osteosarcoma cell line. The tumor cell staining correlated positively with high vWF expression in the sample (P=0.006). Although vascular endothelial cells contribute to the vWF mRNA detected in the tumor samples, there was neither any correlation between vascular density (VD) and vWF mRNA expression nor between VD and clinical outcome. These findings suggest that vWF expression is deregulated in osteosarcoma tumors, potentially contributing to metastasis.

  5. Unwinding the von Willebrand factor strings puzzle.

    PubMed

    De Ceunynck, Karen; De Meyer, Simon F; Vanhoorelbeke, Karen

    2013-01-10

    von Willebrand factor (VWF) is amongst others synthesized by endothelial cells and stored as ultra-large (UL) VWF multimers in Weibel-Palade bodies. Although UL-VWF is proteolysed by ADAMTS13 (a disintegrin-like and metalloprotease domain with thrombospondin type-1 motif, number 13) on secretion from endothelial cells, in vitro experiments in the absence of ADAMTS13 have demonstrated that a proportion of these UL-VWF multimers remain anchored to the activated endothelium. These multimers unravel, bind platelets, and wave in the direction of the flow. These so-called VWF "strings" have also been visualized in vivo, lining the lumen of activated mesenteric veins of Adamts13(-/-) mice. Various studies have demonstrated the extraordinary length of these VWF strings, the availability of their platelet binding and ADAMTS13 cleavage sites, and the possible nature of their endothelial attachment. VWF strings are also capable of tethering leukocytes and parasite-infected red blood cells. However, the majority of studies have been performed in the absence of ADAMTS13, a condition only experienced in thrombotic thrombocytopenic purpura. A normal functional role of VWF strings in healthy persons or in other disease pathologies remains unclear. In this review, we discuss some of the puzzling characteristics of VWF strings, and we debate whether the properties of VWF strings in the absence of ADAMTS13 might be relevant for understanding (patho)physiologic mechanisms.

  6. Richard von Volkmann: surgeon and Renaissance man.

    PubMed

    Willy, Christian; Schneider, Peter; Engelhardt, Michael; Hargens, Alan R; Mubarak, Scott J

    2008-02-01

    Richard von Volkmann (1830-1889), one of the most important surgeons of the 19(th) century, is regarded as one of the fathers of orthopaedic surgery. He was a contemporary of Langenbeck, Esmarch, Lister, Billroth, Kocher, and Trendelenburg. He was head of the Department of Surgery at the University of Halle, Germany (1867-1889). His popularity attracted doctors and patients from all over the world. He was the lead physician for the German military during two wars. From this experience, he compared the mortality of civilian and war injuries and investigated the general poor hygienic conditions in civilian hospitals. This led him to introduce the "antiseptic technique" to Germany that was developed by Lister. His powers of observation and creativity led him to findings and achievements that to this day bear his name: Volkmann's contracture and the Hueter-Volkmann law. Additionally, he was a gifted writer; he published not only scientific literature but also books of children's fairy tales and poems under the pen name of Richard Leander, assuring him a permanent place in the world of literature as well as orthopaedics.

  7. [Obstetric analgesia and anesthesia with remifentanyl in a patient with von Willebrand disease].

    PubMed

    Novoa, L; Navarro Egea, M; Vieito Amor, M; Hernández Iniesta, J; Arxer, A; Villalonga, A

    2003-05-01

    A 30-year-old woman with von Willebrand's disease was admitted in labor. As epidural analgesia was ruled out due to risk of spinal hematoma, a pump for patient-controlled analgesia (PCA) was provided with boluses of remifentanil and set for intravenous infusion of 24 micrograms with a lockout time of 5 minutes. The patient reported analgesia to be satisfactory. Later, because of abnormal fetal positioning, an emergency cesarean was performed with the patient under general anesthesia with remifentanil, with propofol and succinylcholine for induction. A healthy girl was born free of respiratory depression. Von Willebrand's disease is a hemorrhagic disorder of autosomal dominant inheritance due to a quantitative or functional factor VIII deficit. Various subtypes and degrees of severity of abnormal bleeding have been described. It is the most common genetic hemostatic disorder affecting obstetric procedures, and although epidural analgesia has been used with strict hematologic monitoring, that technique carries a risk of hematoma. PCA is useful in patients for whom regional techniques are contraindicated. With adequate fetal and maternal monitoring, remifentanil in PCA is safe and more effective than other opiates for labor pain.

  8. Misfolding of vWF to Pathologically Disordered Conformations Impacts the Severity of von Willebrand Disease

    PubMed Central

    Tischer, Alexander; Madde, Pranathi; Moon-Tasson, Laurie; Auton, Matthew

    2014-01-01

    The primary hemostatic von Willebrand factor (vWF) functions to sequester platelets from rheological blood flow and mediates their adhesion to damaged subendothelium at sites of vascular injury. We have surveyed the effect of 16 disease-causing mutations identified in patients diagnosed with the bleeding diathesis disorder, von Willebrand disease (vWD), on the structure and rheology of vWF A1 domain adhesiveness to the platelet GPIbα receptor. These mutations have a dynamic phenotypical range of bleeding from lack of platelet adhesion to severe thrombocytopenia. Using new rheological tools in combination with classical thermodynamic, biophysical, and spectroscopic metrics, we establish a high propensity of the A1 domain to misfold to pathological molten globule conformations that differentially alter the strength of platelet adhesion under shear flow. Rheodynamic analysis establishes a quantitative rank order between shear-rate-dependent platelet-translocation pause times that linearly correlate with clinically reported measures of patient platelet counts and the severity of thrombocytopenia. These results suggest that specific secondary structure elements remaining in these pathological conformations of the A1 domain regulate GPIbα binding and the strength of vWF-platelet interactions, which affects the vWD functional phenotype and the severity of thrombocytopenia. PMID:25185554

  9. Low von Willebrand factor: sometimes a risk factor and sometimes a disease.

    PubMed

    Sadler, J Evan

    2009-01-01

    A sufficiently low level of von Willebrand factor (VWF) predisposes to bleeding that can be quite serious, and low VWF is a diagnostic feature of von Willebrand disease (VWD) type 1, which is characterized by partial quantitative deficiency of VWF. Recent groundbreaking studies of patients with VWD type 1 have delineated several pathophysiologic mechanisms that determine the plasma concentration of VWF, but the relationship between VWF level and the likelihood of bleeding remains less well understood. In part, this problem reflects the broad range of VWF levels in the population, so that the distinction between "normal" and "low" is arbitrary. The risk of bleeding certainly increases as the VWF level decreases, but the relationship is not very strong until the VWF level is very low. Furthermore, mild bleeding symptoms are common in apparently healthy populations and have many causes other than defects in VWF, which can make it impossible to attribute bleeding to any single factor, such as low VWF. These difficulties might be resolved by an epidemiologic approach to VWF and other risk factors for bleeding, analogous to how physicians manage multiple risk factors for cardiovascular disease or venous thromboembolism.

  10. Impaired megakaryocytopoiesis in type 2B von Willebrand disease with severe thrombocytopenia.

    PubMed

    Nurden, Paquita; Debili, Najet; Vainchenker, William; Bobe, Regis; Bredoux, Raymonde; Corvazier, Elisabeth; Combrie, Robert; Fressinaud, Edith; Meyer, Dominique; Nurden, Alan T; Enouf, Jocelyne

    2006-10-15

    In type 2B von Willebrand disease, there is spontaneous binding of mutated von Willebrand factor (VWF) multimers to platelets. Here we report a family in which severe thrombocytopenia may also be linked to abnormal megakaryocytopoiesis. A heterozygous mutation in the VWF A1 domain gave a R1308P substitution in an interactive site for glycoprotein Ibalpha (GPIbalpha). Electron microscopy showed clusters of platelets in close contact. Binding of antibodies to the GPIbalpha N-terminal domain was decreased, whereas GPIX and GPV were normally detected. In Western blotting (WB), GPIbalpha, alphaIIb, and beta3 were normally present. Proteins involved in Ca(2+) homeostasis were analyzed by quantitating platelet mRNA or by WB. Plasma membrane Ca(2+) ATPase (PMCA)-4b and type III inositol trisphosphate receptor (InsP(3)-R3) were selectively increased. The presence of degradation products of polyadenosine diphosphate (ADP)-ribose polymerase protein (PARP) suggested ongoing caspase-3 activity. These were findings typical of immature normal megakaryocytes cultured from peripheral blood CD34(+) cells with TPO. Significantly, megakaryocytes from the patients in culture produced self-associated and interwoven proplatelets. Immunolocalization showed VWF not only associated with platelets, but already on the megakaryocyte surface and within internal channels. In this family, type 2B VWD is clearly associated with abnormal platelet production.

  11. Laboratory aspects of von Willebrand disease: test repertoire and options for activity assays and genetic analysis.

    PubMed

    Castaman, G; Hillarp, A; Goodeve, A

    2014-05-01

    The deficiency or abnormal function of von Willebrand factor (VWF) causes von Willebrand disease (VWD), the most frequent inherited bleeding disorder. The laboratory diagnosis of VWD can be difficult as the disease is heterogeneous and an array of assays is required to describe the phenotype. Basic classification of quantitative (type 1 and 3) and qualitative (type 2) VWD variants requires determination of VWF antigenic (VWF:Ag) levels and assaying of VWF ristocetin cofactor (VWF:RCo) activity, determining the capacity of VWF to interact with the platelet GPIb-receptor. Knowing the VWF:RCo activity is essential for identifying, subtyping and monitoring VWD, but the assay is poorly standardized and many protocols do not fulfil the clinical need in all situations. This has led to the development of novel activity assays, independent of ristocetin, with enhanced assay characteristics. Results from the first independent clinical evaluations are promising, showing that they are reliable and suitable for VWD diagnosis. The qualitative type 2 VWF deficiency can be further divided into four different subtypes (A, B, M and N) using specific assays that explore other activities or the size distribution of VWF multimers. These methods are discussed herein. However, in a number of patients it may be difficult to correctly classify the VWD phenotype and genetic analysis may provide the best option to clarify the disorder, through mutation identification.

  12. Development and validation of technical assays of von Willebrand disease in routine laboratory.

    PubMed

    Derdabi, Sara; Rozen, Laurence; Nagant, Carole; Demulder, Anne

    2016-12-01

    Von Willebrand disease (MW) is the most common constitutional bleeding disorders. It is caused by a quantitative or qualitative abnormality of the von Willebrand factor (VWF). The laboratory assessment of the disease combines a FVIII assay, and a determination of the antigen and activity of VWF. The analytical validation of VWF:Ag, VWF:Act, vWF:CB is reported in this work and demonstrates good test performance of all three assays, with a coefficient of variation lower than 10% for both the repeatability and reproducibility, stability with a deviation of less than 5% from the target value after six hours at room temperature. The dosages are linear through the following ranges: 2% to 346% for VWF:Ag, 3% to 170% for VWF:Act, and 0.07% to 259% for VWF:CB. The usual values determined on 32 control subjects are in the range of reference values published in the literature. However as the number of control samples tested is small, we will adopt the reference values of the literature of 50 to 200% in routine. The other functional test VWF:CB will be used in our daily practice to differentiate the type of 2M 2A type. However, given that the type 2M is extremely rare, we think it is rather aimed at specialized laboratories in which a large number of patients referred.

  13. Von Willebrand Disease and Pregnancy: A Review of Evidence and Expert Opinion.

    PubMed

    Reynen, Emily; James, Paula

    2016-10-01

    von Willebrand disease (VWD) is a common, inherited bleeding disorder. There are three main types of VWD, which result in a quantitative or qualitative deficiency in von Willebrand factor (VWF) and in severe cases, also Factor VIII (FVIII). The severity of bleeding depends on the underlying pathophysiology. Type 1 VWD is usually mild, while types 2 or 3 VWD can be associated with moderate or significant bleeding. Managing pregnant women with VWD requires a multidisciplinary approach. Such patients are at increased risk of postpartum hemorrhage. Whether women with VWD are at increased risk of spontaneous abortion remains unclear. Because of increased risk of bleeding, there are special considerations for delivery and obstetrical analgesia. There is a lack of high-quality evidence supporting monitoring and treatment of VWD in pregnancy. Most experts recommend that FVIII and VWF levels be monitored prior to delivery and treatment initiated when levels remain below 0.50 IU/mL. Some experts consider desmopressin (DDAVP) to be the preferred initial treatment in type 1 and most type 2 VWD. DDAVP is relatively contraindicated in type 2B disease. Plasma-derived FVIII and VWF replacements are the treatment of choice in type 2B and 3 VWD and in type 1 or 2 VWD when patients do not respond to DDAVP.

  14. Evidence-based recommendations on the treatment of von Willebrand disease in Italy

    PubMed Central

    Mannucci, Pier Mannuccio; Franchini, Massimo; Castaman, Giancarlo; Federici, Augusto B.

    2009-01-01

    Background von Willebrand disease (VWD) is the most common hereditary bleeding disorder affecting both males and females. It arises from quantitative or qualitative defects of von Willebrand factor (VWF) and causes bleeding of mucous membranes and soft tissues. The aim of treatment is to correct the dual defect of haemostasis caused by the abnormal/reduced VWF and the concomitant deficiency of factor VIII (FVIII). Material and methods This document contains evidence-based recommendations for the management of VWD compiled by AICE (the Italian Association of Haemophilia Centres). All the evidence supporting these recommendations are based on non-randomised comparative studies or case series, because randomised controlled clinical trials or meta-analyses are not available for this disease. Results and conclusions Desmopressin (DDAVP) is the treatment of choice for patients with type 1 VWD with FVIII and VWF levels of 10 U/dL or more, while VWF/FVIII concentrates are indicated for those who are unresponsive or insufficiently responsive to DDAVP (severe type 1, type 2 and 3 VWD). VWF concentrates devoid of FVIII, not yet licensed in Italy, may be considered for short-term prophylaxis in elective surgery or for long-term secondary prophylaxis. PMID:19503633

  15. [Determination of von Willebrand factor multimers in Mexican population].

    PubMed

    Hernández-Zamora, Edgar; Zavala-Hernández, Cesar; Viveros-Sandoval, Martha Eva; Ochoa-Rico, Angeles; Martínez-Murillo, Carlos; Reyes-Maldonado, Elba

    2014-01-01

    Antecedentes: la enfermedad de von Willebrand es un padecimiento hereditario en el que la estructura, función y concentración del factor de von Willebrand están alteradas y, en consecuencia, también la interacción plaqueta-factor de von Willebrand-endotelio. En México no hay registros epidemiológicos de la enfermedad, sólo se han efectuado algunos estudios aislados desde el punto de vista clínico y hematológico. Material y métodos: estudio retrospectivo efectuado en 155 mexicanos mestizos, 75 de ellos con diagnóstico presuntivo de enfermedad de von Willebrand, 15 con sospecha de hemofilia A y 65 donadores sanos (testigos). Se realizaron pruebas: básicas de coagulación, especiales y de clasificación: análisis de la composición multimérica. Resultados: 15 pacientes se diagnosticaron con hemofilia A; de los 75 sujetos con sospecha de enfermedad de von Willebrand se diagnosticaron 50 de la manera siguiente: tipo 1 (62%), tipo 2 (22%) [subtipos: 2A (14%), 2B (2%) y 2N (6%)] y tipo 3 (16%). Conclusión: el análisis de los multímeros del factor de von Willebrand es un método que cumple con las características adecuadas para el diagnóstico de la enfermedad de von Willebrand, por lo que es necesario implementar esta metodología para su estudio y mejorar su diagnóstico específico.

  16. Locally Compact Quantum Groups. A von Neumann Algebra Approach

    NASA Astrophysics Data System (ADS)

    Van Daele, Alfons

    2014-08-01

    In this paper, we give an alternative approach to the theory of locally compact quantum groups, as developed by Kustermans and Vaes. We start with a von Neumann algebra and a comultiplication on this von Neumann algebra. We assume that there exist faithful left and right Haar weights. Then we develop the theory within this von Neumann algebra setting. In [Math. Scand. 92 (2003), 68-92] locally compact quantum groups are also studied in the von Neumann algebraic context. This approach is independent of the original C^*-algebraic approach in the sense that the earlier results are not used. However, this paper is not really independent because for many proofs, the reader is referred to the original paper where the C^*-version is developed. In this paper, we give a completely self-contained approach. Moreover, at various points, we do things differently. We have a different treatment of the antipode. It is similar to the original treatment in [Ann. Sci. & #201;cole Norm. Sup. (4) 33 (2000), 837-934]. But together with the fact that we work in the von Neumann algebra framework, it allows us to use an idea from [Rev. Roumaine Math. Pures Appl. 21 (1976), 1411-1449] to obtain the uniqueness of the Haar weights in an early stage. We take advantage of this fact when deriving the other main results in the theory. We also give a slightly different approach to duality. Finally, we collect, in a systematic way, several important formulas. In an appendix, we indicate very briefly how the C^*-approach and the von Neumann algebra approach eventually yield the same objects. The passage from the von Neumann algebra setting to the C^*-algebra setting is more or less standard. For the other direction, we use a new method. It is based on the observation that the Haar weights on the C^*-algebra extend to weights on the double dual with central support and that all these supports are the same. Of course, we get the von Neumann algebra by cutting down the double dual with this unique

  17. Entwicklungsperspektiven von Social Software und dem Web 2.0

    NASA Astrophysics Data System (ADS)

    Raabe, Alexander

    Der Artikel beschäftigt sich zunächst mit dem derzeitigen und zukünftigen Einsatz von Social Software in Unternehmen. Nach dem großen Erfolg von Social Software im Web beginnen viele Unternehmen eigene Social Software-Initiativen zu entwickeln. Der Artikel zeigt die derzeit wahrgenommenen Einsatzmöglichkeiten von Social Software im Unternehmen auf, erörtert Erfolgsfaktoren für die Einführung und präsentiert mögliche Wege für die Zukunft. Nach der Diskussion des Spezialfalles Social Software in Unternehmen werden anschließend die globalen Trends und Zukunftsperspektiven des Web 2.0 in ihren technischen, wirtschaftlichen und sozialen Dimensionen dargestellt. Wie aus den besprochenen Haupttrends hervorgeht, wird die Masse an digital im Web verfügbaren Informationen stetig weiterwachsen. So stellt sich die Frage, wie es in Zukunft möglich sein wird, die Qualität der Informationssuche und der Wissensgenerierung zu verbessern. Mit dem Einsatz von semantischen Technologien im Web wird hier eine revolutionäre Möglichkeit geboten, Informationen zu filtern und intelligente, gewissermaßen verstehende" Anwendungen zu entwerfen. Auf dem Weg zu einem intelligenten Web werden sich das Semantic Web und Social Software annähern: Anwendungen wie Semantic Wikis, Semantic Weblogs, lightweight Semantic Web-Sprachen wie Microformats oder auch kommerzielle Angebote wie Freebase von Metaweb werden die ersten Vorzeichen einer dritten Generation des Webs sein.

  18. Biosynthesis of von Willebrand protein by human megakaryocytes.

    PubMed

    Sporn, L A; Chavin, S I; Marder, V J; Wagner, D D

    1985-09-01

    Immunofluorescence staining of buffy coat smears from a patient with chronic myelogenous leukemia in accelerated phase showed that approximately 13% of all nucleated cells contained von Willebrand protein and, therefore, appeared to be of megakaryocytic origin. This was confirmed by positive staining with antisera against platelet factor 4 and platelet glycoproteins. Short-term cultures of the buffy coat, which lacked endothelial cells, were metabolically labeled with [35S]methionine, and von Willebrand protein was immunopurified from cell lysates and culture medium. Cultures from this patient synthesized and secreted von Willebrand protein, in contrast with cultures from other patients with leukemia, who lacked circulating megakaryocytes, and from normal volunteers. The subunit composition of the megakaryocytic von Willebrand protein was very similar to that of human umbilical vein endothelial cells. The size of the processed subunit (220 kD) and of the cellular (260 kD) and secreted (275 kD) precursors from the two cell types were indistinguishable by gel electrophoresis. Furthermore, the ratio of precursor to processed subunit and the pattern of cellular and secreted nonreduced multimers were very similar. It appears, therefore, that the processing steps in biosynthesis of von Willebrand protein used by the megakaryocytes are very similar to those of umbilical vein endothelial cells.

  19. Biographical sketch: Georg Hermann von Meyer (1815-1892).

    PubMed

    Skedros, John G; Brand, Richard A

    2011-11-01

    This biographical sketch on Georg Hermann von Meyer highlights the interactions in the 1860s that von Meyer, a famous anatomist, had with Karl Culmann, a famous structural engineer and mathematician. The published papers from this interaction caught the attention of Julius Wolff and stimulated his development of the trajectorial hypothesis of bone adaptation--now called "Wolff's Law." The corresponding translations are provided: (1) von Meyer's 1867 paper that highlights the regularity of arched trabecular patterns in various human bones, and his discussions with Culmann about their possible mechanical relevance; and (2) Wolff's 1869 paper that first mentions the correspondence of stress trajectories in a solid, crane-like structure to the arched trabecular patterns in the proximal human femur. This biographical sketch on Georg Hermann von Meyer corresponds to the historic texts, The Classic: The Architecture of the Trabecular bone (by von Meyer), and The Classic: On the Significance of the Architecture of the Spongy Substance for the Question of Bone Growth. A preliminary publication (by Wolff) available at DOIs 10.1007/s11999-011-2041-5 , 10.1007/s11999-011-2042-4 .

  20. Thrombospondin-1 in von Willebrand factor function.

    PubMed

    Bonnefoy, Arnaud; Hoylaerts, Marc F

    2008-10-01

    Thrombospondin-1 (TSP1), expressed in many cells and tissues is abundantly present in platelet alpha-granules, from where it is released upon platelet activation. Murine Tsp1(-/-) platelet studies have revealed that TSP1 is redundant for platelet aggregation, but that it reinforces platelet aggregate stabilization, especially in a shear field. von Willebrand factor (VWF), synthesized by megakaryocytes and endothelial cells is stored both in platelet alpha-granules and in endothelial Weibel-Palade bodies as ultralarge multimers. When released from endothelial cells, these multimers are temporarily retained on the endothelium, to be cleaved by the plasma protease ADAMTS13 into smaller and hemostatically less reactive multimers, released in plasma. This protease shows partial sequence identity with the type 1 (TSR1) and type 2 (TSR2) repeats of TSP1 and contains 1 TSR1 and 6 TSR2 repeats. TSP1, locally released by platelets, competes with ADAMTS13 during VWF proteolysis and controls the degree of VWF multimer processing. In addition, TSP1 and VWF both interact with the platelet GPIb/V/IX membrane complex, primarily in flow. These interactions control the recruitment of platelets to (sub) endothelial VWF and TSP1, exposed to the circulation, as a consequence of vascular inflammation and endothelial injury. TSP1-VWF interactions do not strictly enhance platelet recruitment and secreted TSP1 even weakly competes with the dynamic platelet rolling and adhesion onto VWF. Hence, TSP1 and VWF show partially related hemostatic functions, the most important one being the TSP1 role in the ADAMTS13 operated VWF multimer processing, in pro-inflammatory and thrombogenic conditions.

  1. Evaluation of a von Willebrand factor three test panel and chemiluminescent-based assay system for identification of, and therapy monitoring in, von Willebrand disease.

    PubMed

    Favaloro, Emmanuel J; Mohammed, Soma

    2016-05-01

    von Willebrand disease (VWD) is reportedly the most common bleeding disorder and arises from deficiency and/or defects of von Willebrand factor (VWF). Laboratory diagnosis and typing of VWD has important management implications and requires a wide range of tests, including VWF antigen (VWF:Ag) and various activities, involving differential identification of qualitative vs quantitative VWF defects. We have assessed a new hemostasis instrument, the chemiluminescent assay based ACL AcuStar™, and an associated HemosIL AcuStar three test panel comprising VWF:Ag, VWF ristocetin cofactor (VWF:RCo) and VWF collagen binding (VWF:CB) (Instrumentation Laboratory, Bedford, Ma. USA) for ability to identify VWD, to help provisionally type VWD, and for potential use in therapy monitoring. This test system was compared to previously evaluated and validated test systems including VWF:RCo on CS-5100 and BCS analyzers, the new Siemens INNOVANCE assay (VWF Ac) on CS-5100, and VWF:Ag and VWF:CB assays performed by automated ELISA. We employed a large total sample test set (n=535) comprising plasma and platelet-lysate samples from individuals with and without VWD, some on treatment, normal plasmas, and normal and pathological controls. We also evaluated desmopressin (DDAVP) responsiveness, plus differential sensitivity to reduction in high molecular weight (HMW) VWF. The chemiluminescent test panel (VWF:Ag, VWF:RCo, VWF:CB) showed good comparability to similar assays performed by alternate methods, and broadly similar data for identification of VWD, provisional VWD type identification, DDAVP and VWD therapy, and HMW VWF sensitivity, although some notable differences were evident. The chemiluminescent system showed best low level VWF sensitivity, and lowest inter-assay variability, compared to all other systems. In conclusion, we have validated theACL AcuStar and the chemiluminescent HemosIL AcuStar VWF test panel for use in VWD diagnostics, and have identified some favorable

  2. Linking contemporary high resolution magnetic resonance imaging to the von Economo legacy: A study on the comparison of MRI cortical thickness and histological measurements of cortical structure.

    PubMed

    Scholtens, Lianne H; de Reus, Marcel A; van den Heuvel, Martijn P

    2015-08-01

    The cerebral cortex is a distinctive part of the mammalian nervous system, displaying a spatial variety in cyto-, chemico-, and myelinoarchitecture. As part of a rich history of histological findings, pioneering anatomists von Economo and Koskinas provided detailed mappings on the cellular structure of the human cortex, reporting on quantitative aspects of cytoarchitecture of cortical areas. Current day investigations into the structure of human cortex have embraced technological advances in Magnetic Resonance Imaging (MRI) to assess macroscale thickness and organization of the cortical mantle in vivo. However, direct comparisons between current day MRI estimates and the quantitative measurements of early anatomists have been limited. Here, we report on a simple, but nevertheless important cross-analysis between the histological reports of von Economo and Koskinas on variation in thickness of the cortical mantle and MRI derived measurements of cortical thickness. We translated the von Economo cortical atlas to a subdivision of the commonly used Desikan-Killiany atlas (as part of the FreeSurfer Software package and a commonly used parcellation atlas in studies examining MRI cortical thickness). Next, values of "width of the cortical mantle" as provided by the measurements of von Economo and Koskinas were correlated to cortical thickness measurements derived from high-resolution anatomical MRI T1 data of 200+ subjects of the Human Connectome Project (HCP). Cross-correlation revealed a significant association between group-averaged MRI measurements of cortical thickness and histological recordings (r = 0.54, P < 0.001). Further validating such a correlation, we manually segmented the von Economo parcellation atlas on the standardized Colin27 brain dataset and applied the obtained three-dimensional von Economo segmentation atlas to the T1 data of each of the HCP subjects. Highly consistent with our findings for the mapping to the Desikan-Killiany regions, cross

  3. Committee Opinion No.580: von Willebrand disease in women.

    PubMed

    2013-12-01

    Von Willebrand disease, the most common inherited bleeding disorder among American women, is a common cause of heavy menstrual bleeding and other bleeding problems in women and adolescent girls. Von Willebrand disease and other inherited and acquired disorders of coagulation and hemostasis should be considered in the differential diagnosis of all patients being evaluated for heavy menstrual bleeding, regardless of age. There are many treatment options available for patients with von Willebrand disease and heavy menstrual bleeding, including hormonal and nonhormonal therapies. A multidisciplinary approach to management, which involves obstetrician-gynecologists and hematologists, results in optimal treatment outcomes. Many resources exist for patients and health care providers through the National Heart, Lung, and Blood Institute; National Hemophilia Foundation; and the American Society of Hematology.

  4. Screening for von Willebrand disease: contribution of an automated assay for von Willebrand factor activity.

    PubMed

    Lasne, D; Dey, C; Dautzenberg, M-D; Cherqaoui, Z; Monge, F; Aouba, A; Torchet, M-F; Geloen, D; Landais, P; Rothschild, C

    2012-05-01

    Measuring von Willebrand factor (VWF) activity is essential to the diagnosis of von Willebrand disease (VWD). The VWF activity is usually assessed based on measurement of the ristocetin cofactor (VWF:RCo). However, that test is technically challenging and has high intra- and inter-assay variabilities. The HemosIL VWF activity (VWF:AC) is a fully automated assay, recently proposed as a good alternative to VWF:RCo for VWD diagnosis. This study was undertaken to assess this new method. First, the analytical performance of VWF:AC on an automated coagulo-meter (ACLTop) was determined, and then this new method was compared with VWF:RCo and the platelet function analyzer (PFA100) for 160 patients referred for VWD screening. The VWF:AC achieved acceptable precision with within-run and between-run coefficients of variation ranging from 2.3% to 14.1%, and linearity from 10% to 100%. Despite some marked differences between VWF:AC and VWF:RCo for 10 plasmas tested, their agreement for VWD diagnosis was good. The VWF:AC had sensitivity similar to that of PFA100 (close to 100%), but better specificity (97.7% vs. 66% or 60%, depending on the cartridge used). The good analytical performance, and the sensitivity and specificity of VWF:AC to detect VWF deficiency renders it a suitable method for VWD screening. Our findings support VWF:AC use for the diagnostic work-up of VWD, paying close attention to concomitant clinical signs and bleeding score, as recommended for VWD. © 2011 Blackwell Publishing Ltd.

  5. The smooth entropy formalism for von Neumann algebras

    SciTech Connect

    Berta, Mario; Furrer, Fabian; Scholz, Volkher B.

    2016-01-15

    We discuss information-theoretic concepts on infinite-dimensional quantum systems. In particular, we lift the smooth entropy formalism as introduced by Renner and collaborators for finite-dimensional systems to von Neumann algebras. For the smooth conditional min- and max-entropy, we recover similar characterizing properties and information-theoretic operational interpretations as in the finite-dimensional case. We generalize the entropic uncertainty relation with quantum side information of Tomamichel and Renner and discuss applications to quantum cryptography. In particular, we prove the possibility to perform privacy amplification and classical data compression with quantum side information modeled by a von Neumann algebra.

  6. Weibel-Palade bodies: a window to von Willebrand disease.

    PubMed

    Valentijn, K M; Eikenboom, J

    2013-04-01

    Weibel-Palade bodies (WPBs) are the storage organelles for von Willebrand factor (VWF) in endothelial cells. VWF forms multimers that assemble into tubular structures in WPBs. Upon demand, VWF is secreted into the blood circulation, where it unfolds into strings that capture platelets during the onset of primary hemostasis. Numerous mutations affecting VWF lead to the bleeding disorder von Willebrand disease. This review reports the recent findings on the effects of VWF mutations on the biosynthetic pathway of VWF and its storage in WPBs. These new findings have deepened our understanding of VWF synthesis, storage, secretion, and function.

  7. Endothelial dysfunction in von Willebrand disease: angiogenesis and angiodysplasia.

    PubMed

    Randi, Anna M

    2016-05-01

    In recent years, new functions for the haemostatic protein von Willebrand Factor (VWF) have emerged. Amongst these is the ability to modulate the development of new blood vessels, a process called angiogenesis. The subtle effects that VWF exerts on blood vessel formation and stability may be relevant for the small but significant fraction of patients with von Willebrand disease (VWD) who also present with vascular malformations (angiodysplasia) in the gastrointestinal tract, often responsible for intractable bleeding. This review will briefly summarise the evidence and discuss the molecular pathways involved.

  8. An Accurate von Neumann's Law for Three-Dimensional Foams

    SciTech Connect

    Hilgenfeldt, Sascha; Kraynik, Andrew M.; Koehler, Stephan A.; Stone, Howard A.

    2001-03-19

    The diffusive coarsening of 2D soap froths is governed by von Neumann's law. A statistical version of this law for dry 3D foams has long been conjectured. A new derivation, based on a theorem by Minkowski, yields an explicit analytical von Neumann's law in 3D which is in very good agreement with detailed simulations and experiments. The average growth rate of a bubble with F faces is shown to be proportional to F{sup 1/2} for large F , in contrast to the conjectured linear dependence. Accounting for foam disorder in the model further improves the agreement with data.

  9. Henry Cavendish, Johann von Soldner, and the deflection of light

    NASA Astrophysics Data System (ADS)

    Will, Clifford M.

    1988-05-01

    The gravitational deflection of light based on Newtonian theory and the corpuscular model of light was calculated, but never published, around 1784 by Henry Cavendish, almost 20 years earlier than the first published calculation by Johann Georg von Soldner. The two results are slightly different because, while Cavendish treated a light ray emitted from infinity, von Soldner treated a light ray emitted from the surface of the gravitating body. At the first order of approximation, they agree with each other; both are one-half the value predicted by general relativity and confirmed by experiment.

  10. The smooth entropy formalism for von Neumann algebras

    NASA Astrophysics Data System (ADS)

    Berta, Mario; Furrer, Fabian; Scholz, Volkher B.

    2016-01-01

    We discuss information-theoretic concepts on infinite-dimensional quantum systems. In particular, we lift the smooth entropy formalism as introduced by Renner and collaborators for finite-dimensional systems to von Neumann algebras. For the smooth conditional min- and max-entropy, we recover similar characterizing properties and information-theoretic operational interpretations as in the finite-dimensional case. We generalize the entropic uncertainty relation with quantum side information of Tomamichel and Renner and discuss applications to quantum cryptography. In particular, we prove the possibility to perform privacy amplification and classical data compression with quantum side information modeled by a von Neumann algebra.

  11. Eugen von Gothard and His X-Ray Experiments

    NASA Astrophysics Data System (ADS)

    Vincze, Ildikó J.; Jankovics, István

    2010-03-01

    Eugen von Gothard (1857-1909) made significant contributions to astrophysics and founded the Astrophysical Observatory in Herény, Hungary, in 1881. He also was a gifted instrument maker who designed and produced the apparatus and equipment he needed to carry out his researches, which enabled him to respond immediately to Wilhelm Conrad Röntgen’s astonishing discovery of X rays. Von Gothard took his first X-ray photograph on January 23, 1896, thus inaugurating his first series of experiments, which ended on May 26, 1896. He carried out a second series of experiments on June 21-22, 1905, four years before his premature death at age 51.

  12. Von Kármán between Aachen and Pasadena

    NASA Astrophysics Data System (ADS)

    Krause, Egon; Kalkmann, Ulrich

    2013-05-01

    In the Introduction the reader is referred back to the academic ceremonials held after Theodore von Kármán's death in Aachen in May 1963. His work as the first director of the Aerodynamisches Institut (Institute of Aerodynamics) of the RWTH Aachen University of Technology from 1913 on and his initiative to re-establish international cooperation after World War I, resulting in the International Union of Theoretical and Applied Mechanics (IUTAM), are commented on. The following chapter describes von Kármán's relation to his former teacher Ludwig Prandtl. Some of von Kármán's scientific contributions during his time in Aachen are briefly reviewed. Thereafter, his first contacts to the California Institute of Technology are covered. Finally, the scientific and political circumstances, which led to von Kármán's decision to leave Germany in the early thirties, are elucidated in some detail. The English translation of the titles of the Aachen papers is given in Appendix I.

  13. Professor Oberth and Dr. von Braun at ARS Banquet

    NASA Technical Reports Server (NTRS)

    1961-01-01

    Dr. Wernher von Braun holds the coveted Hermarn Oberth award presented to him by Professor Oberth during the banquet hosted by the Alabama Section of the American Rocket Society (ARS), on October 19, 1961. The Oberth award was given for outstanding technical contributions to the field of astronautics or for the promotion and advancement of astronautical sciences.

  14. von Braun Examines Bendix Mobility Test Article (MTA)

    NASA Technical Reports Server (NTRS)

    1964-01-01

    Marshall Space Flight Center (MSFC) director, Wernher von Braun, and others examine one concept of a possible Lunar Roving Vehicle (LRV) built by the Bendix Corporation. The data provided by the MTA helped in designing the LRV, developed under the direction of MSFC. The LRV was designed to allow Apollo astronauts a greater range of mobility during lunar exploration missions.

  15. von Braun Examines Bendix Mobility Test Article (MTA)

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Marshall Space Flight Center (MSFC) director, Wernher von Braun, and a visitor, examine one concept of a possible Lunar Roving Vehicle (LRV) built by the Bendix Corporation. The data provided by the MTA helped in designing the LRV, developed under the direction of MSFC. The LRV was designed to allow Apollo astronauts a greater range of mobility during lunar exploration missions.

  16. Dr. Wernher Von Braun near the mobile launcher.

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Dr. George Mueller, NASA associate administrator for manned space flight, and Dr. Wernher Von Braun (right), director of the Marshall Space Flight Center, are seen near the mobile launcher carrying a 363 foot tall Saturn V space launch vehicle as the rocket is rolled from the vehicle assembly building at KSC for its three mile trip to the launch pad.

  17. Current therapy in children and adolescents with von Willebrand disease.

    PubMed

    Buga-Corbu, I; Arion, C

    2014-06-15

    The article represents a review of recent data about the therapy of von Willebrand disease in children and adolescents (hereditary as well as acquired forms of the disease). The treatment of bleeding events in these patients, the indications in different subtypes, and the future lines of research are mentioned.

  18. Ernst von Glasersfeld's Radical Constructivism and Truth as Disclosure

    ERIC Educational Resources Information Center

    Joldersma, Clarence W.

    2011-01-01

    In this essay Clarence Joldersma explores radical constructivism through the work of its most well-known advocate, Ernst von Glasersfeld, who combines a sophisticated philosophical discussion of knowledge and truth with educational practices. Joldersma uses Joseph Rouse's work in philosophy of science to criticize the antirealism inherent in…

  19. Wernher von Braun: Reflections on His Contributions to Space Exploration

    NASA Technical Reports Server (NTRS)

    Goldman, Arthur E.

    2012-01-01

    In 1950, Dr. Wernher von Braun and approximately 100 of his team members came to Huntsville, Alabama, to begin work with the Army on what would later become America's historic space program. He would later serve as the first director of the Marshall Space Flight Center and led the development of the Saturn V launch vehicle that launched seven crewed American mission to the moon, as well as America s first space station, Skylab. Von Braun is best known for his team s technical achievements. He realized his dream of exploring outer space by helping place humans on the moon. His engineering and managerial talent during the Apollo era had contributed to a technological revolution. He was by all accounts a good engineer, but he was only one among many. What set Von Braun apart were his charisma, his vision, and his leadership skills. He inspired loyalty and dedication in the people around him. He understood the importance of communicating his vision to his team, to political and business leaders and the public. Today, the Marshall Center continues his vision by pursuing engineering and scientific projects that will continue to open space to exploration. This presentation will discuss Von Braun's impact on Huntsville, the Marshall Center, the nation and the world and look at his contributions in context of where world space exploration is today.

  20. Dr. von Braun With a Model of a Launch Vehicle

    NASA Technical Reports Server (NTRS)

    1950-01-01

    Dr. von Braun stands beside a model of the upper stage (Earth-returnable stage) of the three-stage launch vehicle built for the series of the motion picture productions of space flight produced by Walt Disney in the mid-1950's.

  1. Ernst von Glasersfeld's Radical Constructivism and Truth as Disclosure

    ERIC Educational Resources Information Center

    Joldersma, Clarence W.

    2011-01-01

    In this essay Clarence Joldersma explores radical constructivism through the work of its most well-known advocate, Ernst von Glasersfeld, who combines a sophisticated philosophical discussion of knowledge and truth with educational practices. Joldersma uses Joseph Rouse's work in philosophy of science to criticize the antirealism inherent in…

  2. Dr. Wernher Von Braun near the mobile launcher.

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Dr. George Mueller, NASA associate administrator for manned space flight, and Dr. Wernher Von Braun (right), director of the Marshall Space Flight Center, are seen near the mobile launcher carrying a 363 foot tall Saturn V space launch vehicle as the rocket is rolled from the vehicle assembly building at KSC for its three mile trip to the launch pad.

  3. Wilhelm von Humboldt's Idea of "Bildung" and Education.

    ERIC Educational Resources Information Center

    Stubbs, Elsina

    The importance of Wilhelm von Humboldt's work in educational philosophy is little known outside of Germany and even there he is more often criticized than praised. This is unfortunate because his contributions to education and other areas had an important impact on other philosophers of his period and are well worth considering today. In his main…

  4. Dr. von Braun Conferring With NASA Headquarters Officials

    NASA Technical Reports Server (NTRS)

    1961-01-01

    This photograph, dated November 13, 1961, shows Dr. von Braun conferring with two officials from NASA Headquarters. Dr. Brainered Holmes is on the left. Dr. Nicholas Golovin is in the center. Holmes was Director of NASA's Office of Marned Space Flight. Golovin was Director of Systems Engineering at Headquarters.

  5. Treasure in the Library Attic: Von Ranke at Syracuse.

    ERIC Educational Resources Information Center

    Coville, Bruce

    1984-01-01

    Traces history of private library of German scholar, Leopold von Ranke, which was purchased by Syracuse University in 1888. Efforts of librarian Charles W. Bennett in 1870s and Professor James Powell beginning in late 1960s, and restoration and cataloging of collection are highlighted. Items from the collection are noted. (EJS)

  6. Dr. von Braun With a Model of a Launch Vehicle

    NASA Technical Reports Server (NTRS)

    1950-01-01

    Dr. von Braun stands beside a model of the upper stage (Earth-returnable stage) of the three-stage launch vehicle built for the series of the motion picture productions of space flight produced by Walt Disney in the mid-1950's.

  7. Changes in von Willebrand factor and ADAMTS13 during IVF.

    PubMed

    Westerlund, Eli; Antovic, Aleksandra; Hovatta, Outi; Eberg, Karin P; Blombäck, Margareta; Wallén, Håkan; Henriksson, Peter

    2011-03-01

    During IVF, circulating estradiol concentrations are strongly increased, and this may have direct effects on hemostasis. Elevated von Willebrand factor levels represent an important risk factor for arterial and venous thrombosis. ADAMTS13, also known as von Willebrand factor-cleaving protease, has an important regulatory function of von Willebrand factor but has not been studied during IVF. Blood was sampled from 31 women at maximal downregulation of estradiol synthesis using gonadotropin-releasing hormone analogues and during high-level stimulation of estradiol synthesis using follicle-stimulating hormone during the first phase of IVF. Von Willebrand factor antigen, von Willebrand factor ristocetin cofactor activity, factor VIII and ADAMTS13 antigen and activity levels in plasma were determined at the time of downregulation and at high-level stimulation. Estradiol increased from a mean of 154 pg/ml at downregulation to 5889 pg/ml at high-level stimulation (range 1620-19 500 pg/ml). Factor VIII increased from 0.96 ± 0.34 to 1.26 ± 0.41 kIU/l (P < 0.001). Von Willebrand factor antigen and activity increased from 0.75 ± 0.22 to 1.06 ± 0.40 kIU/l (P < 0.001) and from 0.83 ± 0.26 to 1.24 ± 0.48 kIU/l (P < 0.001), respectively. ADAMTS13 antigen decreased from 72.2 ± 13.5 to 67.9 ± 9.9% (P < 0.05, P = 0.01) and ADAMTS13 activity from 88.6 ± 18.3 to 80.8 ± 15.7% (P < 0.01). The increments in estradiol and factor VIII during IVF were paralleled by an increase in von Willebrand factor antigen and activity, and a decrease in circulating ADAMTS13 antigen and activity, respectively. This could in part explain why these patients have an increased risk of thrombotic events.

  8. Hemostatic efficacy, safety, and pharmacokinetics of a recombinant von Willebrand factor in severe von Willebrand disease.

    PubMed

    Gill, Joan C; Castaman, Giancarlo; Windyga, Jerzy; Kouides, Peter; Ragni, Margaret; Leebeek, Frank W G; Obermann-Slupetzky, Ortrun; Chapman, Miranda; Fritsch, Sandor; Pavlova, Borislava G; Presch, Isabella; Ewenstein, Bruce

    2015-10-22

    This phase 3 trial evaluated the safety and hemostatic efficacy of a recombinant von Willebrand factor (rVWF) for treatment of bleeds in severe von Willebrand disease (VWD). rVWF was initially administered together with recombinant factor VIII (rFVIII) and subsequently alone, as long as hemostatic factor VIII activity (FVIII : C) levels were maintained. Pharmacokinetics (PK) were evaluated in a randomized cross-over design (rVWF vs rVWF:rFVIII at 50 IU VWF:ristocetin cofactor activity [RCo]/kg). Bleed control for all treated bleeds (N = 192 bleeds in 22 subjects) was rated good or excellent (96.9% excellent; 119 of 122 minor, 59 of 61 moderate, and 6 of 7 major bleeds) on a 4-point scale (4 = none to 1 = excellent). A single infusion was effective in 81.8% of bleeds. Treatment success, defined as the number of subjects with a mean efficacy rating of <2.5, was 100%. The PK profile of rVWF was not influenced by rFVIII (mean VWF:RCo terminal half-life: 21.9 hours for rVWF and 19.6 hours for rVWF:rFVIII). FVIII : C levels increased rapidly after rVWF alone, with hemostatic levels achieved within 6 hours and sustained through 72 hours after infusion. Eight adverse events (AEs; 6 nonserious AEs in 4 subjects and 2 serious AEs [chest discomfort and increased heart rate, without cardiac symptomatology] concurrently in 1 subject) were associated with rVWF. There were no thrombotic events or severe allergic reactions. No VWF or FVIII inhibitors, anti-VWF binding antibodies, or antibodies against host cell proteins were detected. These results show that rVWF was safe and effective in treating bleeds in VWD patients and stabilizes endogenous FVIII : C, which may eliminate the need for rFVIII after the first infusion. This trial was registered at www.clinicaltrials.gov as #NCT01410227.

  9. Hemostatic efficacy, safety, and pharmacokinetics of a recombinant von Willebrand factor in severe von Willebrand disease

    PubMed Central

    Gill, Joan C.; Castaman, Giancarlo; Windyga, Jerzy; Kouides, Peter; Ragni, Margaret; Leebeek, Frank W. G.; Obermann-Slupetzky, Ortrun; Chapman, Miranda; Fritsch, Sandor; Pavlova, Borislava G.; Presch, Isabella

    2015-01-01

    This phase 3 trial evaluated the safety and hemostatic efficacy of a recombinant von Willebrand factor (rVWF) for treatment of bleeds in severe von Willebrand disease (VWD). rVWF was initially administered together with recombinant factor VIII (rFVIII) and subsequently alone, as long as hemostatic factor VIII activity (FVIII:C) levels were maintained. Pharmacokinetics (PK) were evaluated in a randomized cross-over design (rVWF vs rVWF:rFVIII at 50 IU VWF:ristocetin cofactor activity [RCo]/kg). Bleed control for all treated bleeds (N = 192 bleeds in 22 subjects) was rated good or excellent (96.9% excellent; 119 of 122 minor, 59 of 61 moderate, and 6 of 7 major bleeds) on a 4-point scale (4 = none to 1 = excellent). A single infusion was effective in 81.8% of bleeds. Treatment success, defined as the number of subjects with a mean efficacy rating of <2.5, was 100%. The PK profile of rVWF was not influenced by rFVIII (mean VWF:RCo terminal half-life: 21.9 hours for rVWF and 19.6 hours for rVWF:rFVIII). FVIII:C levels increased rapidly after rVWF alone, with hemostatic levels achieved within 6 hours and sustained through 72 hours after infusion. Eight adverse events (AEs; 6 nonserious AEs in 4 subjects and 2 serious AEs [chest discomfort and increased heart rate, without cardiac symptomatology] concurrently in 1 subject) were associated with rVWF. There were no thrombotic events or severe allergic reactions. No VWF or FVIII inhibitors, anti-VWF binding antibodies, or antibodies against host cell proteins were detected. These results show that rVWF was safe and effective in treating bleeds in VWD patients and stabilizes endogenous FVIII:C, which may eliminate the need for rFVIII after the first infusion. This trial was registered at www.clinicaltrials.gov as #NCT01410227. PMID:26239086

  10. Expression of abnormal von Willebrand factor by endothelial cells from a patient with type IIA von Willebrand disease.

    PubMed Central

    Levene, R B; Booyse, F M; Chediak, J; Zimmerman, T S; Livingston, D M; Lynch, D C

    1987-01-01

    Studies were conducted to characterize the biosynthesis of von Willebrand factor (vWf) by cultured endothelial cells (EC) derived from the umbilical vein of a patient with type IIA von Willebrand disease. The patient's EC, compared with those from normal individuals, produced vWf that had decreased amounts of large multimers and an increase in rapidly migrating satellite species, features characteristic of plasma vWf from patients with type IIA von Willebrand disease. The type IIA EC did produce a full spectrum of vWf multimers in both cell lysates and postculture medium, although the relative amounts of the largest species were decreased. The large multimers were degraded in conjunction with the appearance of rapidly migrating satellites that contained approximately equal to 170-kDa proteolytic fragments, suggesting that this patient's functional defect is due to abnormal proteolysis and not to a primary failure of vWf subunit oligomerization. Moreover, the observed degradation appears to result from an abnormal vWf molecule and not elevated protease levels. These results suggest that this patient's von Willebrand disease phenotype is caused by increased proteolytic sensitivity of his vWf protein. Images PMID:3306682

  11. Enhanced Local Disorder in a Clinically Elusive von Willebrand Factor Provokes High-Affinity Platelet Clumping.

    PubMed

    Tischer, Alexander; Machha, Venkata R; Frontroth, Juan P; Brehm, Maria A; Obser, Tobias; Schneppenheim, Reinhard; Mayne, Leland; Walter Englander, S; Auton, Matthew

    2017-07-07

    Mutation of the cysteines forming the disulfide loop of the platelet GPIbα adhesive A1 domain of von Willebrand factor (VWF) causes quantitative VWF deficiencies in the blood and von Willebrand disease. We report two cases of transient severe thrombocytopenia induced by DDAVP treatment. Cys1272Trp and Cys1458Tyr mutations identified by genetic sequencing implicate an abnormal gain-of-function phenotype, evidenced by thrombocytopenia, which quickly relapses back to normal platelet counts and deficient plasma VWF. Using surface plasmon resonance, analytical rheology, and hydrogen-deuterium exchange mass spectrometry (HXMS), we decipher mechanisms of A1-GPIbα-mediated platelet adhesion and resolve dynamic secondary structure elements that regulate the binding pathway. Constrained by the disulfide, conformational selection between weak and tight binding states of A1 takes precedence and drives normal platelet adhesion to VWF. Less restrained through mutation, loss of the disulfide preferentially diverts binding through an induced-fit disease pathway enabling high-affinity GPIbα binding and firm platelet adhesion to a partially disordered A1 domain. HXMS reveals a dynamic asymmetry of flexible and ordered regions common to both variants, indicating that the partially disordered A1 lacking the disulfide retains native-like structural dynamics. Both binding mechanisms share common structural and thermodynamic properties, but the enhanced local disorder in the disease state perpetuates high-affinity platelet agglutination, characteristic of type 2B VWD, upon DDAVP-stimulated secretion of VWF leading to transient thrombocytopenia and a subsequent deficiency of plasma VWF, characteristic of type 2A VWD. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Marshall-Stickler phenotype associated with von Willebrand disease

    SciTech Connect

    MacDonald, M.R.; Baker, K.S.; Schaefer, G.B.

    1997-01-20

    We report on 6 individuals from three different kindreds with Marshall-Stickler (MS) phenotype, with characteristic orofacial abnormalities, arthropathy, deafness, and eye findings, all of whom were discovered to have a mild bleeding diathesis and coagulation-study findings consistent with mild von Willebrand disease (vWD). MS syndrome has been linked in some cases to the type II procollagen gene (COL2A1) on chromosome 12q, and to the collagen XI gene (COL11A2) on chromosome 6. The von Willebrand factor (vWF) is encoded by a 180-Kb gene located on the short arm of chromosome 12. This is the first reported association of these two disorders. 26 refs., 5 figs., 1 tab.

  13. Subarachnoid hemorrhage associated with von Willebrand's disease--case report.

    PubMed

    Nakau, Reiko; Nomura, Motohiro; Kida, Shinya; Yamashita, Junkoh; Kinoshita, Akira; Nitta, Hisashi; Muramatsu, Naoki

    2005-12-01

    A 59-year-old woman with type IIA von Willebrand's disease (VWD) presented with subarachnoid hemorrhage (SAH). Computed tomography showed SAH in the right sylvian fissure and intracranial hemorrhage in the right temporal lobe. Angiography demonstrated an aneurysm at the bifurcation of the right middle cerebral artery. Neck clipping was performed on the 3rd day after the onset with intra- and postoperative administration of factor VIII/von Willebrand factor concentrate. No excessive bleeding occurred. Patients with prolonged bleeding time should be screened for VWD before surgery. This is a rare case of VWD presenting with SAH secondary to ruptured intracranial aneurysm. The clinical characteristics and the management of SAH in a patient with VWD are discussed.

  14. Eine FPAA-Architektur zur rekonfigurierbaren Instantiierung von zeitkontinuierlichen Analogfiltern

    NASA Astrophysics Data System (ADS)

    Becker, J.; Manoli, Y.

    2005-05-01

    Im Folgenden wird eine neue Methodik von FPAAs (Field Programmable Analog Arrays) gezeigt, die speziell für die Instantiierung von zeitkontinuierlichen (continuous-time, CT) Analogfiltern in Hardware entwickelt wurde. Die Chiptopologie beinhaltet 17 digital konfigurierbare analoge Blöcke (configurable analog blocks, CABs), die durch ein hexagonales Netzwerk miteinander verbunden sind. Jeder CAB ist aus einstellbaren Gm-C Integratoren aufgebaut, welche das analoge Signal sowohl formen und seinen Weg durch die Matrix festlegen, gleichzeitig aber auch die Grundbausteine für zeitkontinuierliche Hochfrequenzfilter darstellen. Intelligente Pufferspeicher für die Ein-/Ausgänge (IO-buffer) garantieren die Rekonfigurierung der Matrix mit minimaler Störung des kontinuierlichen Analogsignals. Die Architektur wird als Hardwareplattform für beliebige Schaltungen, welche aus einer gegebenen Anzahl an Gm-C-Zellen bestehen, eingeführt und verifiziert bevor eine exemplarische Instantiierung eines Butterworth Filters 4. Ordnung in Biquad Anordnung gezeigt wird.

  15. Altered megakaryocytopoiesis in von Willebrand type 2B disease.

    PubMed

    Nurden, A T; Federici, A B; Nurden, P

    2009-07-01

    Type 2B von Willebrand disease (VWD2B) is caused by gain-of-function amino acid substitutions in the von Willebrand factor (VWF) A1 domain. These allow facilitated binding of mutated VWF to platelet GPIbalpha with prolonged lifetimes of VWF bonds and enhanced ADAMTS-13 cleavage of large VWF multimers. A bleeding rather than prothrombotic syndrome is due to: (i) decreased large VWF multimers in plasma; (ii) limited thrombus formation; and (iii) thrombocytopenia affecting some but not all patients. Accumulating evidence points to an altered megakaryocytopoiesis in VWD2B with the production of enlarged or giant platelets showing an abnormal ultrastructure and, in a cohort of patients, the presence of circulating platelet agglutinates. In fact, evidence from in vitro cultures and marrow aspirates suggests that the upregulated VWF function can lead to abnormal VWF trafficking in megakaryocytes, a modified platelet production with interacting proplatelets, and the presence or even release of platelet agglutinates in the bone marrow.

  16. Von eingebetteten Systemen zu Cyber-Physical Systems

    NASA Astrophysics Data System (ADS)

    Wedde, Rorst F.; Lehnhoff, Sebastian; Rehtanz, Christian; Krause, Olav

    Das Hauptanliegen des Papiers ist, ein Paradigma für Probleme mit neuartigen Integrationsanforderungen für Forschung und Entwicklung in verteilten eingebetteten Echtzeitsystemen zu motivieren und vorzustellen, nämlich den Begriff Cyber-Physical Systems. Bei einer in letzter Zeit stark zunehmenden Anzahl von Realzeitanwendungen können ohne die Berücksichtigung solcher Forderungen keine praktisch brauchbaren Lösungen erwartet werden. Einige Anwendungsfelder werden angesprochen. Im Einzelnen werden dann für Elektroautos, die mit erneuerbaren Energien betrieben werden sollen, einerseits die Management-, verteilte Verhandlungs- und Verteilungsprobleme der benötigten Energie in einem bottom-up Ansatz gelöst. Andererseits wird als Teil unserer Projektarbeit die Bereitstellung von Reserveenergie für den allgemeinen Bedarf durch Autobatterien vorgestellt. Es zeigt sich, dass dies effizienter und wesentlich kurzfristiger in unserem verteilten Vorgehen geschehen kann als in traditionellen Verfahren.

  17. The molecular characterization of von Willebrand disease: good in parts.

    PubMed

    James, P D; Lillicrap, D

    2013-04-01

    Since the cloning of the gene that encodes von Willebrand factor (VWF), 27 years ago, significant progress has been made in our understanding of the molecular basis of the most common inherited bleeding disorder, von Willebrand disease (VWD). The molecular pathology of this condition represents a range of genetic mechanisms, some of which are now very well characterized, and others that are still under investigation. In general, our knowledge of the molecular basis of type 2 and 3 VWD is now well advanced, and in some instances this information is being used to enhance clinical management. In contrast, our understanding of the molecular pathogenesis of the most common form of VWD, type 1 disease, is still at an early stage, with preliminary evidence that this phenotype involves a complex interplay between environmental factors and the influence of genetic variability both within and outside of the VWF locus.

  18. An update on type 2B von Willebrand disease.

    PubMed

    Mikhail, Sameh; Aldin, Ehab Saad; Streiff, Michael; Zeidan, Amer

    2014-04-01

    Type 2B von Willebrand disease (VWD) accounts for fewer than 5% of all VWD patients. In this disease, mutations in the A1 domain result in increased von Willebrand factor (VWF) binding to platelet GPIbα receptors, causing increased platelet clearance and preferential loss of high molecular weight VWF multimers. Diagnosis is complicated because of significant clinical variations even among patients with identical mutations. Platelet transfusion often provides suboptimal results since transfused platelets may be aggregated by the patients' abnormal VWF. Desmopressin may cause a transient decrease in platelet count that could lead to an increased risk of bleeding. Replacement therapy with factor VIII/VWF concentrates is the most effective approach to prevention and treatment of bleeding in type 2B VWD.

  19. Comparative analysis of von Willebrand factor profiles after implantation of left ventricular assist device and total artificial heart.

    PubMed

    Reich, H J; Morgan, J; Arabia, F; Czer, L; Moriguchi, J; Ramzy, D; Esmailian, F; Lam, L; Dunhill, J; Volod, O

    2017-08-01

    Essentials Bleeding is a major source of morbidity during mechanical circulatory support. von Willebrand factor (VWF) multimer loss may contribute to bleeding. Different patterns of VWF multimer loss were seen with the two device types. This is the first report of total artificial heart associated VWF multimer loss. Background Bleeding remains a challenge during mechanical circulatory support and underlying mechanisms are incompletely understood. Functional von Willebrand factor (VWF) impairment because of loss of high-molecular-weight multimers (MWMs) produces acquired von Willebrand disease (VWD) after left ventricular assist device (LVAD). Little is known about VWF multimers with total artificial hearts (TAHs). Here, VWF profiles with LVADs and TAHs are compared using a VWD panel. Methods VWD evaluations for patients with LVAD or TAH (2013-14) were retrospectively analyzed and included: VWF activity (ristocetin cofactor, VWF:RCo), VWF antigen (VWF:Ag), ratio of VWF:RCo to VWF:Ag, and quantitative VWF multimeric analysis. Results Twelve patients with LVADs and 12 with TAHs underwent VWD evaluation. All had either normal (47.8%) or elevated (52.2%) VWF:RCo, normal (26.1%) or elevated (73.9%) VWF:Ag and 50.0% were disproportional (ratio ≤ 0.7). Multimeric analysis showed abnormal patterns in all patients with LVADs: seven with high MWM loss; five with highest MWM loss. With TAH, 10/12 patients had abnormal patterns: all with highest MWM loss. High MWM loss correlated with presence of LVAD and highest MWM loss with TAH. Increased low MWMs were detected in 22/24. Conclusion Using VWF multimeric analysis, abnormalities after LVAD or TAH were detected that would be missed with measurements of VWF level alone: loss of high MWM predominantly in LVAD, loss of highest MWM in TAH, and elevated levels of low MWM in both. This is the first study to describe TAH-associated highest MWM loss, which may contribute to bleeding. © 2017 International Society on Thrombosis and

  20. FROM THE HISTORY OF PHYSICS: John von Neumann

    NASA Astrophysics Data System (ADS)

    Monastyrskii, Mikhail I.

    2004-12-01

    This article is dedicated to John von Neumann, one of the most outstanding scholars of the 20th century. His life was short but bright, and his contribution to almost all branches of mathematics, as well as to physics, economics, biology, and astronomy was enormous. He constructed some of the first computers and he was among the key persons in the American atomic project. Development of his ideas will continue to play a vital part in various areas of pure and applied mathematics.

  1. Johann Baptist von Schweitzer: the queer Marx loved to hate.

    PubMed

    Kennedy, H

    1995-01-01

    Despite his conviction on a morals charge involving a boy, the early German Social Democrat Johann Baptist von Schweitzer went on to have a successful political career. His life furnishes the context to present remarks by his political opponents Marx and Engels, which reveal their deep-seated homophobia. It is pointed out that this has been glossed over by the translations of the recently published Marx/Engels Collected Works. Some remarks on boy-love and anarchism are appended.

  2. von Hippel–Lindau disease: A clinical and scientific review

    PubMed Central

    Maher, Eamonn R; Neumann, Hartmut PH; Richard, Stéphane

    2011-01-01

    The autosomal dominantly inherited disorder von Hippel–Lindau disease (VHL) is caused by germline mutations in the VHL tumour suppressor gene (TSG). VHL mutations predispose to the development of a variety of tumours (most commonly retinal and central nervous system haemangioblastomas, clear cell renal carcinoma and phaeochromocytomas). Here, we review the clinical and genetic features of VHL disease, briefly review the molecular pathogenesis and outline clinical management and tumour surveillance strategies. PMID:21386872

  3. Baron von Zach's business relations with the Munich entrepreneur Joseph von Utzschneider (German Title: Geschäftsbeziehungen des Barons von Zach zu dem Münchner Unternehmer Joseph von Utzschneider)

    NASA Astrophysics Data System (ADS)

    Schneider, Ivo

    The relationship between the astronomer von Zach on the one side and the entrepreneur Joseph von Utzschneider and his partner Georg von Reichenbach on the other dates presumably from the year 1807 when Zach spent two months in Munich. Already in the same year Zach had ordered an instrument for himself and began to solicit business for the institute of Reichenbach, Utzschneider, and Liebherr, which was founded in 1804. One of the clients canvassed by Zach was the director of the observatory in Naples Zuccari. Zuccari had ordered the whole equipment for the new observatory from this institute in 1813. The instruments for Naples, which were completed in 1814, were sent accompanied by Reichenbach by land and sea to their destination where Reichenbach supervised their setup. At that time Reichenbach had separated from Utzschneider who kept the optical institute in Benediktbeuern with his new partner Joseph von Fraunhofer whereas Reichenbach became owner of the mathematical-mechanical institute in Munich. For personal and economical reasons Utzschneider began soon after to produce not only optical glass but also optical devices similar to those offered by Reichenbach. As soon as two institutes in Munich competed against each other on the market for sophisticated geodetical and astronomical instruments Zach sided with Utzschneider. Zach's main professional argument for this decision was that both competitors got the optical glass for their instruments from Utzschneider's optical institute in Benediktbeuern. This meant that Utzschneider had first choice and so the optical part of his instruments could be considered as better than that of Reichenbach`s instruments. Zach's role as an agent in Italy and France for the sale of products coming from Utzschneider's manufactories is highlighted by three of Zach's letters to Utzschneider from 1817 and 1818, two of which are reproduced here for the first time.

  4. Dr. von Braun In Front of a Display of Missiles

    NASA Technical Reports Server (NTRS)

    1960-01-01

    In this photo, Director of the US Army Ballistic Missile Agency (ABMA) Development Operations Division, Dr. Wernher von Braun, is standing before a display of Army missiles celebrating ABMA's Fourth Open House. The missiles in the background include (left to right) a satellite on a Juno II shroud with a Nike Ajax pointing left in front of a Jupiter missile. The Lacrosse is in front of the Juno II. The Nike Hercules points skyward in front of the Juno II and the Redstone.

  5. Weyl-von Neumann-Berg theorem for quaternionic operators

    NASA Astrophysics Data System (ADS)

    G, Ramesh

    2016-04-01

    We prove the Weyl-von Neumann-Berg theorem for right linear operators (not necessarily bounded) in a quaternionic Hilbert space: Let N be a right linear normal (need not be bounded) operator in a quaternionic separable infinite dimensional Hilbert space H. Then for a given ɛ > 0, there exists a compact operator K with ↑" separators=" K ↑ < ɛ and a diagonal operator D on H such that N = D + K.

  6. Interpolatability distinguishes LOCC from separable von Neumann measurements

    SciTech Connect

    Childs, Andrew M.; Leung, Debbie; Mančinska, Laura; Ozols, Maris

    2013-11-15

    Local operations with classical communication (LOCC) and separable operations are two classes of quantum operations that play key roles in the study of quantum entanglement. Separable operations are strictly more powerful than LOCC, but no simple explanation of this phenomenon is known. We show that, in the case of von Neumann measurements, the ability to interpolate measurements is an operational principle that sets apart LOCC and separable operations.

  7. Dr. Wernher Von Braun at the launch of Apollo 11.

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Mission officials relax, all smiles, a few moments after the successful launch of the Apollo 11 spacecraft by Saturn V vehicle AS-506. Relieved of the tension of waiting through the countdown are (left to right) Charles W. Matthews, NASA deputy associate administrator for manned space flight; Dr. Wernher Von Braun, Director of the Marshall Space Flight Center; Dr. George E. Meuller, NASA associate administrator for manned spaceflight, and Lt. General Samuel C. Phillips, director of the Apollo program.

  8. Von Humboldt bis Einstein. Berlin als Weltzentrum der exakten Wissenschaften.

    NASA Astrophysics Data System (ADS)

    Meschkowski, H.

    Contents: 1. Die Anfänge. 2. Die Ära Dirichlet-Jacobi. 3. Der Ausbau der experimentellen Naturwissenschaften. 4. Alexander von Humboldt. 5. Berlin wird "Weltzentrum" der Mathematik. 6. Die Ära Helmholtz. 7. Neue Arbeitsweisen der Astronomie. 8. Chemie: Forschung und Industrie. 9. Max Planck. 10. Ins technische Zeitalter. 11. Zur Mathematik der zwanziger Jahre. 12. Albert Einstein. 13. Fortschritte der Grundlagenforschung. 14. Erwin Schrödinger: Physiker, Philosoph und Poet. 15. Zum Schluß.

  9. High dimensional Bernstein-von Mises: simple examples.

    PubMed

    Johnstone, Iain M

    2010-01-01

    In Gaussian sequence models with Gaussian priors, we develop some simple examples to illustrate three perspectives on matching of posterior and frequentist probabilities when the dimension p increases with sample size n: (i) convergence of joint posterior distributions, (ii) behavior of a non-linear functional: squared error loss, and (iii) estimation of linear functionals. The three settings are progressively less demanding in terms of conditions needed for validity of the Bernstein-von Mises theorem.

  10. [Clemens Freiherr von Pirquet, developer of the concept of allergy].

    PubMed

    Bergmann, K C

    2006-07-20

    The pediatrician and scientist, Clemens Freiherr von Pirquet (1874-1929) was the first to coin the term "allergy". His experiments with Behring's serum, which he administered to sick children, led him to an awareness of an interaction between the human organism and pathogens. In his article published in the Müncher Medizinischen Wochenschrift in 1906, he laid the foundation stone for modern allergology.

  11. Dr. von Braun In Front of a Display of Missiles

    NASA Technical Reports Server (NTRS)

    1960-01-01

    In this photo, Director of the US Army Ballistic Missile Agency (ABMA) Development Operations Division, Dr. Wernher von Braun, is standing before a display of Army missiles celebrating ABMA's Fourth Open House. The missiles in the background include (left to right) a satellite on a Juno II shroud with a Nike Ajax pointing left in front of a Jupiter missile. The Lacrosse is in front of the Juno II. The Nike Hercules points skyward in front of the Juno II and the Redstone.

  12. Liegeverhalten und diurnale Verteilung der Liegeperioden von Dromedaren*.

    PubMed

    Sambraus, H H

    1994-01-12

    ZUSAMMENFASSUNG: In Kenia und in Indien wurde je eine Dromedarherde von ca. 70 bzw. ca. 85 Tieren tagsüber und nachts beobachtet. Ermittelt wurde in 30 Min Abständen die Zahl der liegenden Tiere. Die übliche Liegeposition von Kamelen ist in Zusammenhang mit besonderen morphologischen Strukturen zu sehen. Die Dromedare lagen fast ausschließlich (Kenia) bzw. weit überwiegend (Indien) nachts. Das Liegen nahm in beiden Herden bei den Stuten fast die Hälfte des 24-Stunden-Tages ein. Es werden Vergleiche mit dem Liegeverhalten von Rindern angestellt. Lying-down behaviour and its diurnal distribution in dromedaries Two herds of dromedaries, one in Kenya, consisting of about 70 animals, and one in India, consisting of about 85 animals, were observed during the day and at night. The number of animals lying down was determined at 30 min intervals. The usual lying position of camels is rotated to the specific morphological structure. The dromedaries in Kenya lie almost exclusively, and in India predominantly, at night. In both herds, the females spend almost half of the 24-h day lying down. This behaviour is compared to the lying-down behaviour of cattle. 1994 Blackwell Verlag GmbH.

  13. The British Interplanetary Society - Val Cleaver and Wernher von Braun

    NASA Astrophysics Data System (ADS)

    Willhite, I. P.

    This article is concerned with the early relationship between Wernher von Braun and the British Interplanetary Society (BIS). The BIS/Wernher von Braun/Val Cleaver correspondence files located here at the US Space & Rocket Center in Huntsville, Alabama are unparalleled. As one reads the stimulating comments between Cleaver and von Braun, the need to share their thoughts prevails. Following is an excerpt from one letter that whets ones appetite for more. 10 June 1951 Cleaver writes, “I'm so glad you enjoyed my last letter, and look forward to your promised further contribution to our discussion of the ethics of science in general and astronautics in particu- lar. As regards the one particular point on which you found yourself unable to hold your fire, I should say there are really two distinct issues at stake:. . .” This article attempts to represent the best of the letters as they goad each other on scientific principles, means to prevent wars, and other philosophic ideas.

  14. Screening of Von Willebrand Disease in Iranian Women With Menorrhagia

    PubMed Central

    Rahbar, Nahid; Faranoush, Mohammad; Ghorbani, Raheb; Sadr Alsadat, Bahare

    2015-01-01

    Background: Menorrhagia is a common health problem in women, particularly those with bleeding disorders. Little is known about the course of menorrhagia or other bleeding symptoms in women with the most common congenital bleeding disorder, von Willebrand disease (vWD). Objectives: The aim of this study was to estimate the prevalence of vWD in women with diagnosed menorrhagia. Materials and Methods: In this cross-sectional study, a total of 460 consecutive patients, presenting menorrhagia, were analyzed. The initial screening and confirmation tests for the diagnosis of vWD included determination of prothrombin time (PT), partial thromboplastin time (PTT), bleeding time (BT), fibrinogen, factor VIII, vWF antigen, and vWF activity. A questionnaire was filled for every patient. The data were then analyzed using the SPSS software. Results: Mean age of our patients was 32.5 ± 10.6 years. The level of von Willebrand factor in 22.5% and von Willebrand activity in 19.6% of patients was abnormal. The prevalence of vWD among patients with menorrhagia was 24%. Conclusions: The high prevalence of vWD among our patients was the same as other previous reports, suggesting low awareness about this disease and under diagnosis of mild cases. PMID:25763275

  15. Structure of von Willebrand factor and its function in platelet adhesion and thrombus formation.

    PubMed

    Ruggeri, Z M

    2001-06-01

    The adhesive protein von Willebrand factor mediates the initiation and progression of thrombus formation at sites of vascular injury. von Willebrand factor is synthesized in endothelial cells and megakaryocytes as a very large polymer composed of identical subunits. In the plasma, it appears as a series of multimers of regularly decreasing molecular mass, from several thousand to 500 kDa. The size of circulating von Willebrand factor multimers is controlled by proteolytic cleavage carried out by a specific protease. The biological functions of von Willebrand factor are exerted through specific domains that interact with extracellular matrix components and cell membrane receptors to promote the initial tethering and adhesion of platelets to subendothelial surfaces, as well as platelet aggregation. Moreover, von Willebrand factor binds the procoagulant co-enzyme, factor VIII, contributing to its stability and, indirectly, to its function in the generation of fibrin. This chapter presents a review of current knowledge on the structure, biosynthesis and functions of von Willebrand factor.

  16. No-reference image quality assessment through the von Mises distribution.

    PubMed

    Gabarda, Salvador; Cristóbal, Gabriel

    2012-10-01

    An innovative way of calculating the von Mises distribution of image entropy is introduced in this paper. The von Mises distribution's concentration parameter and some fitness parameter that will be defined later have been analyzed in the experimental part for determining their suitability as an image quality assessment measure in some particular distortions such as Gaussian blur or additive Gaussian noise. To achieve such measure, the local Rényi entropy is calculated in four equally spaced orientations and used to determine the parameters of the von Mises distribution of the image entropy. Considering contextual images, experimental results after applying this model show that the best-in-focus noise-free images are associated with the highest values for the von Mises distribution concentration parameter and the highest approximation of image data to the von Mises distribution model. Our defined von Mises fitness parameter experimentally appears also as a suitable no-reference image quality assessment indicator for no-contextual images.

  17. Operational Leadership: A Case of General Helmuth von Moltke (The Younger)

    DTIC Science & Technology

    2007-11-02

    makes his decision too late to have an impact. II. Historical Framework Helmuth Johannes Ludwig von Moltke, known as von Moltke (The Younger) to distin...T. N. Dupuy, A Genius for War (Englewood Cliffs, NJ: Prentis-Hall, Inc. 1977) 140. 1 Otto Friedrich , Blood and Iron: From Bismarck to Hitler the von...Press, 1996) 160. 1 Tuchman, The Guns of August, 73. 1 Friedrich , Blood and Iron, 229. 1 Holmes, “The Schlieffen Plan,” 13. ii

  18. Clumping factor A, von Willebrand factor-binding protein and von Willebrand factor anchor Staphylococcus aureus to the vessel wall.

    PubMed

    Claes, J; Liesenborghs, L; Peetermans, M; Veloso, T R; Missiakas, D; Schneewind, O; Mancini, S; Entenza, J M; Hoylaerts, M F; Heying, R; Verhamme, P; Vanassche, T

    2017-02-09

    Essentials Staphylococcus aureus (S. aureus) binds to endothelium via von Willebrand factor (VWF). Secreted VWF-binding protein (vWbp) mediates S. aureus adhesion to VWF under shear stress. vWbp interacts with VWF and the Sortase A-dependent surface protein Clumping factor A (ClfA). VWF-vWbp-ClfA anchor S. aureus to vascular endothelium under shear stress.

  19. Innovation im Mittelstand am Beispiel Der Senkung Von Mobilitätskosten Durch Schwarmintelligenz"

    NASA Astrophysics Data System (ADS)

    Fischer, Hieronymus

    Die zunehmende Vernetzung von Einzelsystemen im Fahrzeug wird durch den Einsatz weiterer Kommunikationsverbindungen (CAR2X-Kommunikation) zu einer hierarchischen Struktur führen, die den Austausch von Informationen zwischen einer Vielzahl von verteilten heterogenen Subsystemen auf mobilen und stationären Plattformen ermöglicht. Die primären Ziele einer solchen Vernetzung von Cyber-Physical Systems sind die Bereitstellung neuer Dienste im Fahrzeug, die Erhöhung der Verkehrssicherheit sowie die effektive Steuerung der weiter wachsenden Verkehrsströme.

  20. Rigour in quantitative research.

    PubMed

    Claydon, Leica Sarah

    2015-07-22

    This article which forms part of the research series addresses scientific rigour in quantitative research. It explores the basis and use of quantitative research and the nature of scientific rigour. It examines how the reader may determine whether quantitative research results are accurate, the questions that should be asked to determine accuracy and the checklists that may be used in this process. Quantitative research has advantages in nursing, since it can provide numerical data to help answer questions encountered in everyday practice.

  1. Variabilität des Reviergesangs des Buchfinken (Fringilla coelebs) zur Raum-Zeit-Beschreibung von Metapopulationen

    NASA Astrophysics Data System (ADS)

    Nolte, Björn

    2003-10-01

    Der Buchfinkengesang wurde in Potsdam in zwei Hauptpopulationen über drei Jahre aufgenommen. Jedes Individuum wurde eindeutig am individuellen Strophentypenrepertoire identifiziert. Ein weiterer Punkt der die individuelle Wiedererkennung bestätigt ist die hohe Standorttreue der adulten Männchen. Die beschriebene Methode eignet sich für die Untersuchung von gesamten Populationen, um den Wandel des Gesangs von Populationen in Raum und Zeit zu beschreiben. Die Haupterkenntnisse der Arbeit sind: - Die Gesamtanzahl der Grundstrophentypen innerhalb einer Population bleibt über Jahre konstant. - Die relative Häufigkeit jedes einzelnen Strophentyps variiert von Jahr zu Jahr und von Population zu Population. - Gesangslernen erfolgt exakt mit einem Korrektheitsgrad von mindestens 96%. - Das Song-Sharing ist innerhalb der Population hoch. Die diskutierten Mechanismen für das Song-Sharing sind: Die Lebenserwartung, das Zugverhalten, das Lernverhalten, die Etabliertheit von Strophentypen, Weibchenpräferenzen und die Reaktionen der territorialen Männchen. - Weiterhin wurde ein Modell zur kulturellen Evolution des Buchfinkengesangs programmiert, um die Rolle der Einflussfaktoren, wie Fehlerquote, Abwanderungsrate und Laufzeit zu ermitteln. Der Wandel des Dialektes erfolgt graduell in Raum und Zeit. Daher sind keine scharfen Dialektgrenzen anzutreffen. Trotz dieser Tatsache markieren die etablierten Strophentypen die Population. 50 % der Juvenilen siedeln am Geburtsort, auf diese Weise bleibt der Dialekt erhalten und Inzest wird vermieden. -Analysiert man das Repertoire benachbarten Männchen bei isolierten Alleen, so entspricht die Gesangsangleichung in etwa dem Zufall. -Intraindividuelle Vergleiche der quantitativen Parameter des jeweiligen Strophentyps wurden saisonal und annuell durchgeführt. Saisonal konnten für einen Strophentyp ein Trend ermittelt werden. Bei jährlichen Vergleichen konnten intraindividuell ausschließlich nicht signifikante Ergebnisse ermittelt

  2. Spin torque oscillator neuroanalog of von Neumann's microwave computer.

    PubMed

    Hoppensteadt, Frank

    2015-10-01

    Frequency and phase of neural activity play important roles in the behaving brain. The emerging understanding of these roles has been informed by the design of analog devices that have been important to neuroscience, among them the neuroanalog computer developed by O. Schmitt and A. Hodgkin in the 1930s. Later J. von Neumann, in a search for high performance computing using microwaves, invented a logic machine based on crystal diodes that can perform logic functions including binary arithmetic. Described here is an embodiment of his machine using nano-magnetics. Electrical currents through point contacts on a ferromagnetic thin film can create oscillations in the magnetization of the film. Under natural conditions these properties of a ferromagnetic thin film may be described by a nonlinear Schrödinger equation for the film's magnetization. Radiating solutions of this system are referred to as spin waves, and communication within the film may be by spin waves or by directed graphs of electrical connections. It is shown here how to formulate a STO logic machine, and by computer simulation how this machine can perform several computations simultaneously using multiplexing of inputs, that this system can evaluate iterated logic functions, and that spin waves may communicate frequency, phase and binary information. Neural tissue and the Schmitt-Hodgkin, von Neumann and STO devices share a common bifurcation structure, although these systems operate on vastly different space and time scales; namely, all may exhibit Andronov-Hopf bifurcations. This suggests that neural circuits may be capable of the computational functionality as described by von Neumann.

  3. Contiguity and Entire Separability of States on von Neumann Algebras

    NASA Astrophysics Data System (ADS)

    Haliullin, Samigulla

    2017-04-01

    We introduce the notions of the contiguity and entirely separability for two sequences of states on von Neumann algebras. The ultraproducts technique allows us to reduce the study of the contiguity to investigation of the equivalence for two states. Here we apply the Ocneanu ultraproduct and the Groh-Raynaud ultraproduct (see Ocneanu (1985), Groh (J. Operator Theory, 11, 2, 395-404 1984), Raynaud (J. Operator Theory, 48, 1, 41-68, 2002), Ando and Haagerup (J. Funct. Anal., 266, 12, 6842-6913, 2014)), as well as the technique developed in Mushtari and Haliullin (Lobachevskii J. Math., 35, 2, 138-146, 2014).

  4. Kernschmelze Der nachhaltige Einfluss von Nuklearwaffen auf Politik und Wirtschaft

    NASA Astrophysics Data System (ADS)

    Greiner, Bernd

    "Was sollen wir von einer Kultur halten, der die Ethik stets als wesentliches Element des menschlichen Lebens galt, die aber - außer in fachlicher oder spieltheoretischer Terminologie - nicht in der Lage war, über die Möglichkeit zu sprechen, nahezu alle Menschen zu töten?" Der Fragesteller gehört zu den berühmtesten Physikern des 20. Jahrhunderts und zu den nach wie vor Umstrittensten. über ihn wurde in den 1960er Jahren ein international viel beachtetes Theaterstück geschrieben, vor wenigen Jahren gar eine Oper.

  5. Dr. von Braun on the Mobility Test Article (MTA)

    NASA Technical Reports Server (NTRS)

    1966-01-01

    In this June 1966 photograph, Marshall Space Flight Center Director Dr. Wernher von Braun test-drives the Mobility Test Article (MTA), a developmental vehicle built by the Bendix Corporation to test lunar mobility vehicle concepts. The data provided by the MTA helped in designing the Lunar Roving Vehicle (LRV), developed under the direction of the MSFC. The LRV was designed to allow Apollo astronauts a greater range of mobility during lunar exploration missions. The LRVs were deployed during the last three Apollo missions; Apollo 15, Apollo 16, and Apollo 17.

  6. Dr. von Braun Driving the Mobility Test Article

    NASA Technical Reports Server (NTRS)

    1966-01-01

    In this June, 1966 photograph, Marshall Space Flight Center Director, Dr. Wernher von Braun test drives the Mobility Test Article (MTA), a developmental vehicle built by the Bendix Corporation to test lunar mobility concepts. The data provided by the MTA helped in designing the Lunar Roving Vehicle (LRV), developed under the direction of the Marshall Space Flight Center. The LRV was designed to allow Apollo astronauts a greater range during lunar exploration missions and served its purpose during the last three Apollo lunar missions in 1971 and 1972.

  7. Severe hyponatraemia secondary to desmopressin therapy in von Willebrand's disease.

    PubMed

    Bertholini, D M; Butler, C S

    2000-04-01

    A 42-year-old female with von Willebrand's disease was managed with desmopressin and tranexamic acid to aid haemostasis following a vaginal hysterectomy. Severe acute hyponatraemia (134 to 108 mmol/l) developed over two days, culminating in a generalized tonic-clonic seizure and cerebral oedema. Fluid restriction, cessation of desmopressin and hypertonic saline administration led to a full recovery. Desmopressin is known to reduce free water elimination and produce hyponatraemia, but its extent and rate of development in this patient was surprising. Close monitoring of serum sodium and fluid balance is recommended in these patients.

  8. Nutzergerechte Entwicklung der Mensch-Maschine-Interaktion von Fahrerassistenzsystemen

    NASA Astrophysics Data System (ADS)

    König, Winfried

    Durch langjährige Forschungen bei Kfz-Herstellern, Zulieferfirmen und an Hochschulen sind umfangreiche, aber dennoch lückenhafte Erkenntnisse über das Zusammenspiel zwischen FAS und Nutzer gewonnen worden. In deutschen und internationalen Projekten wie z. B. PROMETHEUS, DRIVE, MOTIV, INVENT, RESPONSE und AKTIV haben sich Kfz-Hersteller, Zulieferfirmen, Hochschulen und weitere staatliche und private Forschungseinrichtungen zusammengefunden, um die vorwettbewerbliche Forschung für derartige Systeme voranzutreiben. Im folgenden Kapitel sollen einige der gewonnenen Kenntnisse dargelegt werden, um die Entwicklung des HMI von FAS zu erleichtern.

  9. Driven Liouville von Neumann Equation in Lindblad Form.

    PubMed

    Hod, Oded; Rodríguez-Rosario, César A; Zelovich, Tamar; Frauenheim, Thomas

    2016-05-19

    The Driven Liouville von Neumann approach [J. Chem. Theory Comput. 2014, 10, 2927-2941] is a computationally efficient simulation method for modeling electron dynamics in molecular electronics junctions. Previous numerical simulations have shown that the method can reproduce the exact single-particle dynamics while avoiding density matrix positivity violation found in previous implementations. In this study we prove that in the limit of infinite lead models the underlying equation of motion can be cast in Lindblad form. This provides a formal justification for the numerically observed density matrix positivity conservation.

  10. Otto von Guericke and 17th century cosmology

    NASA Astrophysics Data System (ADS)

    Knobloch, Eberhard

    Otto von Guericke's scientific method was based on reason and experimental science. His cosmology was embedded in theology and can be interpreted as a refutation of Descartes' worldview. He used Nicolaus Cusanus' theory of quantities in order to characterize space. The notion of space has to be distinguished from that of world or heaven. Forces play a crucial role in this respect described by Athanasius Kircher in his "Celestial Journey". Guericke read this work very diligently. In spite of some obvious similarities between Guericke's and Newton's scientific aims and methods there are crucial differences between the scientific convictions and results of these scholars.

  11. Methodisches Vorgehen zur integralen Auslegung von Produkt und Montage

    NASA Astrophysics Data System (ADS)

    Meyer, André; Grauer, Matthias; Rittner, Martin; Zeltner, Stefan; März, Martin; Egelkraut, Sven; Birkner, Klaus; Braun, Steven

    Die Produktlebenszyklen werden durch den steigenden Wettbewerbsdruck stetig kürzer. Dies veranlasst Unternehmen, Produktinnovationen in immer geringeren Zeitabständen auf den Markt zu bringen und Produktentwicklungszeiten zu verkürzen. Zusätzlich wirken sich erhöhte Anforderungen bezüglich Produktzuverlässigkeit und -lebensdauer erschwerend aus. Um dieser Herausforderung zu begegnen ist eine enge Zusammenarbeit zwischen Entwicklung, Konstruktion, Fertigungsplanung und Prozessentwicklung unabdingbar, denn nur durch eine optimale Abstimmung von Konstruktion und Fertigungsprozess lassen sich die hohen Qualitätsanforderungen erfüllen.

  12. An Alternative Perspective on von Winterfeldt et al.'s (1997) Test of Consequence Monotonicity

    ERIC Educational Resources Information Center

    Ho, Moon-Ho R.; Regenwetter, Michel; Niederee, Reinhard; Heyer, Dieter

    2005-01-01

    D. von Winterfeldt, N.-K. Chung, R. D. Luce, and Y. Cho (see record 1997-03378-008) provided several tests for consequence monotonicity of choice or judgment, using certainty equivalents of gambles. The authors reaxiomatized consequence monotonicity in a probabilistic framework and reanalyzed von Winterfeldt et al.'s main experiment via a…

  13. 76 FR 36166 - Culturally Significant Objects Imported for Exhibition; Determinations: “Gabriel von Max: Be...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-21

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF STATE Culturally Significant Objects Imported for Exhibition; Determinations: ``Gabriel von Max: Be-Tailed Cousins... the exhibition ``Gabriel von Max: Be-Tailed Cousins and Phantasms of the Soul,'' imported from...

  14. The Fate of Western Civilization: G. H. von Wright's Reflections on Science, Technology, and Global Society

    ERIC Educational Resources Information Center

    Heikkero, Topi

    2004-01-01

    This article introduces the central ideas of G. H. von Wright's cultural philosophy concerning the techno-scientific form of life. Georg Henrik von Wright (1916-2003) was best known for his achievements in the field of modal logic and for his association with Ludwig Wittgenstein. However, his work also included a critical analysis of science and…

  15. VON HIPPEL LINDAU SYNDROME AND SURVEILLANCE: A FIVE YEAR FOLLOW UP CASE REPORT.

    PubMed

    Junaid, Muhammad; Ur Rashid, Mamoon; Afsheen, Afeera; Tahir, Ayesha; Ahmad, Mamoon; Kalsoom, Anisa

    2015-01-01

    Von Hipple Lindau disease is a rare genetic autosomal dominant disorder, characterized by formation of tumors and fluid-filled cysts (sacs) in multiple organs of the body, which also carry a potential for malignancy. We are reporting a case of a young 20 years old female who presented to our department with von Hipple Lindau disease.

  16. An Alternative Perspective on von Winterfeldt et al.'s (1997) Test of Consequence Monotonicity

    ERIC Educational Resources Information Center

    Ho, Moon-Ho R.; Regenwetter, Michel; Niederee, Reinhard; Heyer, Dieter

    2005-01-01

    D. von Winterfeldt, N.-K. Chung, R. D. Luce, and Y. Cho (see record 1997-03378-008) provided several tests for consequence monotonicity of choice or judgment, using certainty equivalents of gambles. The authors reaxiomatized consequence monotonicity in a probabilistic framework and reanalyzed von Winterfeldt et al.'s main experiment via a…

  17. Karl ernst von Baer's 'Uber Entwickelungsgeschichte der Thiere II' and its unpublished drawings.

    PubMed

    Tammiksaar, Erki; Brauckmann, Sabine

    2004-01-01

    In 1828 Karl Ernst von Baer (1792-1876) published his seminal Uber Entwickelungsgeschichte der Thiere. Beobachtung und Reflexion. In the preface he announced that a second volume with one copper plate would be finished 'in a few weeks'. However, it took nine years until the unfinished second volume was released, with four copperplates. In his 'Autobiography', von Baer did not clarify the reasons why he did not finish his research program of comparative embryology. The paper attempts to elucidate them, furnished by archival documents and von Baer's unpublished embryological drawings. Our sketch of a few figures will show that (1) von Baer searched for 'analogies' (homologies) as a unifying principle and (2) explained the mechanisms of embryogenesis by physiological reasoning (electromagnetism). The main objective is to show that technical problems in illustrating and conceptual difficulties impeded von Baer's ambitious research program.

  18. A visit paid to Jung by Alwine von Keller.

    PubMed

    Bernardini, Riccardo; Quaglino, Gian Piero; Romano, Augusto

    2011-04-01

    In the winter of 1943-1944, Jung had suffered a coronary thrombosis which almost cost him his life. During his illness, Jung experienced a series of visions, described in his Memories, Dreams, Reflections, which were also to influence significantly the development of his theoretical thinking. On 27(th) September 1944, Alwine von Keller (1878-1965) paid a visit to Jung, while he was still convalescing, in Zurich and documented her meeting with him in a series of notes, recently discovered, which testify to the fact that, at the time of their meeting, Jung was engaged in writing the 'Salt' chapter of Mysterium coniunctionis and investigating the alchemistic symbolism of the 'sea'. This theme seems to testify to a continuity of interests on Jung's part with the seminar he held at Eranos the previous year on the cartographic art of Opicinus de Canistris (1296-c.1352). With its addition of many unpublished details, Alwine von Keller's notes supplement the report which Jung made of his visions experienced during his sickness in MDR. In particular, these attest to the fact that Jung had attributed the terrible experience which he had endured to the problem of the conjunctio, which was confronting him from the theoretical point of view in his writing of Mysterium coniunctionis. © 2011, The Society of Analytical Psychology.

  19. Minimal sufficient statistical experiments on von Neumann algebras

    NASA Astrophysics Data System (ADS)

    Kuramochi, Yui

    2017-06-01

    A statistical experiment on a von Neumann algebra is a parametrized family of normal states on the algebra. This paper introduces the concept of minimal sufficiency for statistical experiments in such operator algebraic situations. We define equivalence relations of statistical experiments indexed by a common parameter set by completely positive or Schwarz coarse-graining and show that any statistical experiment is equivalent to a minimal sufficient statistical experiment unique up to normal isomorphism of outcome algebras. We also establish the relationship between the minimal sufficiency condition for a statistical experiment in this paper and those for subalgebra. These concepts and results are applied to the concatenation relation for completely positive channels with general input and outcome von Neumann algebras. In the case of the quantum-classical channel corresponding to the positive-operator valued measure (POVM), we prove the equivalence of the minimal sufficient condition previously proposed by the author and that in this paper. We also give a characterization of the discreteness of a POVM up to postprocessing equivalence in terms of the corresponding quantum-classical channel.

  20. The von Neumann model of measurement in quantum mechanics

    SciTech Connect

    Mello, Pier A.

    2014-01-08

    We describe how to obtain information on a quantum-mechanical system by coupling it to a probe and detecting some property of the latter, using a model introduced by von Neumann, which describes the interaction of the system proper with the probe in a dynamical way. We first discuss single measurements, where the system proper is coupled to one probe with arbitrary coupling strength. The goal is to obtain information on the system detecting the probe position. We find the reduced density operator of the system, and show how Lüders rule emerges as the limiting case of strong coupling. The von Neumann model is then generalized to two probes that interact successively with the system proper. Now we find information on the system by detecting the position-position and momentum-position correlations of the two probes. The so-called 'Wigner's formula' emerges in the strong-coupling limit, while 'Kirkwood's quasi-probability distribution' is found as the weak-coupling limit of the above formalism. We show that successive measurements can be used to develop a state-reconstruction scheme. Finally, we find a generalized transform of the state and the observables based on the notion of successive measurements.

  1. Von Braun Rocket Team at Fort Bliss, Texas

    NASA Technical Reports Server (NTRS)

    1940-01-01

    The German Rocket Team, also known as the Von Braun Rocket Team, poses for a group photograph at Fort Bliss, Texas. After World War II ended in 1945, Dr. Wernher von Braun led some 120 of his Peenemuende Colleagues, who developed the V-2 rocket for the German military during the War, to the United Sttes under a contract to the U.S. Army Corps as part of Operation Paperclip. During the following five years the team worked on high altitude firings of the captured V-2 rockets at the White Sands Missile Range in New Mexico, and a guided missile development unit at Fort Bliss, Texas. In April 1950, the group was transferred to the Army Ballistic Missile Agency (ABMA) at Redstone Arsenal in Huntsville, Alabama, and continued to work on the development of the guided missiles for the U.S. Army until transferring to a newly established field center of the National Aeronautic and Space Administration (NASA), George C. Marshall Space Flight Center (MSFC).

  2. von Willebrand factor, Jedi knight of the bloodstream.

    PubMed

    Springer, Timothy A

    2014-08-28

    When blood vessels are cut, the forces in the bloodstream increase and change character. The dark side of these forces causes hemorrhage and death. However, von Willebrand factor (VWF), with help from our circulatory system and platelets, harnesses the same forces to form a hemostatic plug. Force and VWF function are so closely intertwined that, like members of the Jedi Order in the movie Star Wars who learn to use "the Force" to do good, VWF may be considered the Jedi knight of the bloodstream. The long length of VWF enables responsiveness to flow. The shape of VWF is predicted to alter from irregularly coiled to extended thread-like in the transition from shear to elongational flow at sites of hemostasis and thrombosis. Elongational force propagated through the length of VWF in its thread-like shape exposes its monomers for multimeric binding to platelets and subendothelium and likely also increases affinity of the A1 domain for platelets. Specialized domains concatenate and compact VWF during biosynthesis. A2 domain unfolding by hydrodynamic force enables postsecretion regulation of VWF length. Mutations in VWF in von Willebrand disease contribute to and are illuminated by VWF biology. I attempt to integrate classic studies on the physiology of hemostatic plug formation into modern molecular understanding, and point out what remains to be learned.

  3. Von Willebrand factor and angiogenesis: basic and applied issues.

    PubMed

    Randi, A M; Laffan, M A

    2017-01-01

    The recent discovery that von Willebrand factor (VWF) regulates blood vessel formation has opened a novel perspective on the function of this complex protein. VWF was discovered as a key component of hemostasis, capturing platelets at sites of endothelial damage and synthesized in megakaryocytes and endothelial cells (EC). In recent years, novel functions and binding partners have been identified for VWF. The finding that loss of VWF in EC results in enhanced, possibly dysfunctional, angiogenesis is consistent with the clinical observations that in some patients with von Willebrand disease (VWD), vascular malformations can cause severe gastrointestinal (GI) bleeding. In vitro and in vivo studies indicate that VWF can regulate angiogenesis through multiple pathways, both intracellular and extracellular, although their relative importance is still unclear. Investigation of these pathways has been greatly facilitated by the ability to isolate EC from progenitors circulating in the peripheral blood of normal controls and patients with VWD. In the next few years, these will yield further evidence on the molecular pathways controlled by VWF and shed light on this novel and fascinating area of vascular biology. In this article, we will review the evidence supporting a role for VWF in blood vessel formation, the link between VWF dysfunction and vascular malformations causing GI bleeding and how they may be causally related. Finally, we will discuss how these findings point to novel therapeutic approaches to bleeding refractory to VWF replacement therapy in VWD.

  4. Von Braun Rocket Team at Fort Bliss, Texas

    NASA Technical Reports Server (NTRS)

    1940-01-01

    The German Rocket Team, also known as the Von Braun Rocket Team, poses for a group photograph at Fort Bliss, Texas. After World War II ended in 1945, Dr. Wernher von Braun led some 120 of his Peenemuende Colleagues, who developed the V-2 rocket for the German military during the War, to the United Sttes under a contract to the U.S. Army Corps as part of Operation Paperclip. During the following five years the team worked on high altitude firings of the captured V-2 rockets at the White Sands Missile Range in New Mexico, and a guided missile development unit at Fort Bliss, Texas. In April 1950, the group was transferred to the Army Ballistic Missile Agency (ABMA) at Redstone Arsenal in Huntsville, Alabama, and continued to work on the development of the guided missiles for the U.S. Army until transferring to a newly established field center of the National Aeronautic and Space Administration (NASA), George C. Marshall Space Flight Center (MSFC).

  5. Prophylaxis in von Willebrand Disease: Coming of Age?

    PubMed

    Saccullo, Giorgia; Makris, Mike

    2016-07-01

    Although in most cases von Willebrand disease (VWD) is a mild disorder, a subgroup of patients experience frequent bleeding. In contrast to severe hemophilia in which prophylaxis is the accepted standard of care, this is less frequently used in VWD. Most type 1 VWD patients can be adequately managed with episodic desmopressin and tranexamic acid. In patients with more severe disease, especially those with type 3 VWD, joint bleeds, epistaxis, menorrhagia, and gastrointestinal bleeding are problematic and usually require treatment with von Willebrand factor/factor VIII (VWF/FVIII) concentrate. While in the past these patients were managed with on-demand VWF/FVIII concentrate, several recent reports have demonstrated the value of prophylactic treatment. Despite some uncertainties about the economic impact of treatment of severe VWD, prophylaxis with VWF concentrate should now be considered as the standard of care for the more severe end of the spectrum of affected individuals. The recent introduction of recombinant VWF concentrate is likely to improve the acceptability of prophylaxis in VWD.

  6. Acquired von Willebrand syndrome in patients with Gaucher disease.

    PubMed

    Mitrovic, Mirjana; Elezovic, Ivo; Miljic, Predrag; Suvajdzic, Nada

    2014-04-01

    Although various coagulation abnormalities occur in patients with Gaucher disease (GD), von Willebrand factor (vWF) deficiency has rarely been reported. A retrospective review of six treatment naïve cases with GD and concomitant vWF deficiency over a 12-year-period in a single center is presented. All patients had a personal history of prior hemorrhages. Based on both reduced level of vWF antigen (vWF:Ag, range 14-56%) and ristocetin cofactor activity (vWF:RCo, range 12-53%), with a vWF:RCo/Ag ratio >0.7, the diagnosis of type 1 von Willebrand disease was made in all six cases. During enzyme replacement therapy (ERT) of a 2-year duration all patients normalized their vWF:Ag levels. Based on the positive ERT effect on vWF:Ag levels, vWF deficiency was assumed to be acquired. It should be noted that beside vWF deficiency four patients with GD exhibited mild thrombocytopenia (range 81-131×10(9)/L) and three had additional hemostatic defects (reduced collagen platelet aggregation, FV, FXI and FXII deficiencies).

  7. Cryptic von Hippel-Lindau disease: germline mutations in patients with haemangioblastoma only

    PubMed Central

    Hes, F; McKee, S; Taphoorn, M; Rehal, P; van der Luijt, R B; McMahon, R; van der Smagt, J J; Dow, D; Zewald, R; Whittaker, J; Lips, C; MacDonald, F; Pearson, P; Maher, E

    2000-01-01

    OBJECTIVES— Central nervous system haemangioblastoma (HAB) is a major feature of von Hippel-Lindau (VHL) disease, and it is estimated that about 30% of HAB patients have VHL disease. Consequently, it is widely recommended that sporadic HAB patients are screened for clinical and radiological features of VHL disease because of the risk of multiple tumours. We investigated the frequency of VHL germline mutations in patients with HAB only with no clinical or radiological evidence of VHL disease to define the role of molecular genetic analysis in the management of such patients.
METHODS—Eighty four patients with a single HAB (23 Dutch, 61 UK) and four with multiple HAB (two Dutch, two UK) were studied by direct sequencing of the coding region and quantitative Southern blotting.
RESULTS—A VHL germline mutation was found in three of 69 (4.3%) single HAB patients aged 50 years or less (three of 84 (3.6%) total single HAB patients). A germline VHL mutation was detected in a 44 year old woman with a solitary cerebellar HAB, as well as in four clinically unaffected close relatives, and in two single HAB cases presenting at the ages of 29 and 36 years. Germline VHL mutations were detected in two of four cases with multiple HAB.
CONCLUSIONS—Early detection of VHL disease is important to reduce morbidity and mortality and therefore we recommend that, in addition to conventional clinical and radiological investigations, VHL gene mutation analysis should be offered to all HAB patients younger than 50 years. HAB patients aged >50 years will have a lower a priori risk of VHL disease and further data are required to evaluate the role of routine molecular genetic investigations in late onset HAB cases. The failure to detect germline VHL mutations in some patients with multiple HAB may indicate the presence of somatic mosaicism or additional HAB susceptibility genes.


Keywords: haemangioblastoma; von Hippel-Lindau disease; VHL; germline mutation PMID

  8. The "Normandy" variant of von Willebrand disease: characterization of a point mutation in the von Willebrand factor gene.

    PubMed

    Gaucher, C; Jorieux, S; Mercier, B; Oufkir, D; Mazurier, C

    1991-05-01

    We previously reported a functional defect of von Willebrand factor (vWF) in a new variant of von Willebrand disease (vWD) tentatively named vWD "Normandy." The present work has attempted to characterize the molecular abnormality of this vWF that fails to bind factor VIII (FVIII). The immunopurified vWF from normal and patient's plasma were digested by trypsin and the resulting peptides were compared. The electrophoresis of "vWF Normandy" showed a shift in the band corresponding to a polypeptide from amino acid 1 to 272. Consequently, we performed the molecular analysis of the portion of the vWF gene of this patient encoding this amino acid sequence. Exons 18-24 were amplified by the use of polymerase chain reaction and their nucleotide sequences corresponding to 1.8 kb were determined. Our analysis showed a point mutation C to T at codon 791, resulting in the substitution of Methionine for Threonine at position 28 of the mature vWF subunit. Because this nucleotide substitution destroyed a Mae II restriction site, this mutation was conveniently sought in various individual DNAs. The patterns obtained were consistent with the homozygous and heterozygous state of this mutation in the patient and in her son, respectively, and with its absence in 28 normal individuals. We conclude that Threonine at position 28 in plasma vWF may be crucial for the conformation and FVIII-binding capacity of its cystine-rich N-terminal domain.

  9. Visualizing the von Willebrand factor/glycoprotein Ib-IX axis with a platelet-type von Willebrand disease mutation.

    PubMed

    Guerrero, Jose A; Kyei, Mark; Russell, Susan; Liu, Junling; Gartner, T Kent; Storrie, Brian; Ware, Jerry

    2009-12-24

    Platelet-type von Willebrand disease (PT-VWD) is a bleeding disorder of the platelet glycoprotein Ib-IX/von Willebrand factor (VWF) axis caused by mutations in the glycoprotein Ib-IX receptor that lead to an increased affinity with VWF. In this report, platelets from a mouse expressing a mutation associated with PT-VWD have been visualized using state-of-the art image collection and processing. Confocal analysis revealed that VWF bound to the surface of single platelets and bridging micro-aggregates of platelets. Surface-bound VWF appears as a large, linear structure on the surface of 50% of the PT-VWD platelets. In vivo thrombus formation after chemical injury to the carotid artery revealed a severe impairment to occlusion as a consequence of the PT-VWD mutation. In vitro stimulation of PT-VWD platelets with adenosine diphosphate or thrombin demonstrates a significant block in their ability to bind fibrinogen. The impairment of in vivo thrombus formation and in vitro fibrinogen binding are more significant than might be expected from the observed platelet binding to VWF polymers over a small portion of the plasma membrane. Visualization of the receptor/ligand interaction and characterization of a severe antithrombotic phenotype provide a new understanding on the molecular basis of bleeding associated with the PT-VWD phenotype.

  10. Variable content of von Willebrand factor mutant monomer drives the phenotypic variability in a family with von Willebrand disease.

    PubMed

    Chen, Junmei; Hinckley, Jesse D; Haberichter, Sandra; Jacobi, Paula; Montgomery, Robert; Flood, Veronica H; Wong, Randall; Interlandi, Gianluca; Chung, Dominic W; López, José A; Di Paola, Jorge

    2015-07-09

    Von Willebrand disease (VWD) is an inherited bleeding disorder characterized by incomplete penetrance and variable expressivity. We evaluated a 24-member pedigree with VWD type 2 caused by a T>G mutation at position 3911 that predicts a methionine to arginine (M1304R) change in the platelet-binding A1 domain of von Willebrand factor (VWF). This mutation manifests as an autosomal-dominant trait, with clinical and biochemical phenotypic variability among affected individuals, including differences in bleeding tendency and VWF quantity, activity, and multimer pattern. Sequencing of all VWF coding regions in 3 affected individuals did not identify additional mutations. When expressed in heterologous cells, M1304R was secreted in lower quantities, failed to drive formation of storage granules, and was defective in multimerization and platelet binding. When cotransfected in equal quantities with the wild-type complementary DNA, the mutant complementary DNA depressed VWF secretion, although multimerization was only mildly affected. A llama nanobody (AU/VWFa-11) that detects the mutant A1 domain demonstrated highly variable binding to VWF from different affected members, indicating that the VWF contained different percentages of mutant monomers in different individuals. Thus, the observed variability in VWD phenotypes could in part be determined by the extent of mutant monomer incorporation in the final multimer structure of plasma VWF.

  11. Histological and biochemical characterization of von Ebner's glands in the Syrian hamster; comparison with rat von Ebner's glands.

    PubMed

    Paliwal, A; Srikantan, S; De, P K; Hand, A R; Redman, R S

    2006-01-01

    We report here for the first time a morphological description and observations on some of the secretory proteins of the von Ebner's lingual salivary glands (VEG) of the Syrian hamster. Hamster VEG were macroscopically less distinct, but histologically similar to rat VEG. VEG extracts of hamster and rat were assayed for lipase, alpha-amylase and peroxidase activities. Unlike rat VEG, which is rich in lipase activity, hamster VEG extract had no detectable lipase activity and did not react with antibodies to either rat lingual lipase or human gastric lipase in Western blots. Immunohistochemical reactions with the anti-rat lingual lipase antibody were very weak in hamster VEG and strong in rat VEG. Moderate alpha-amylase enzyme activities and immunohistochemical reactions were demonstrated in both hamster and rat VEG. Peroxidase activity was negligible in the VEG, unlike the high activity in the submandibular glands of both species. An 18 kDa von Ebner's gland protein (VEGP), a member of the lipocalin superfamily of hydrophobic ligandbinding proteins, was abundant in rat VEG, but not detected in hamster VEG. Thus, hamster VEG differs from rat VEG in macroscopic appearance and the absence of lipase and VEGP. It is similar to rat VEG histologically and with regard to the presence of alpha-amylase and absence of peroxidase.

  12. Quantitative plant proteomics.

    PubMed

    Bindschedler, Laurence V; Cramer, Rainer

    2011-02-01

    Quantitation is an inherent requirement in comparative proteomics and there is no exception to this for plant proteomics. Quantitative proteomics has high demands on the experimental workflow, requiring a thorough design and often a complex multi-step structure. It has to include sufficient numbers of biological and technical replicates and methods that are able to facilitate a quantitative signal read-out. Quantitative plant proteomics in particular poses many additional challenges but because of the nature of plants it also offers some potential advantages. In general, analysis of plants has been less prominent in proteomics. Low protein concentration, difficulties in protein extraction, genome multiploidy, high Rubisco abundance in green tissue, and an absence of well-annotated and completed genome sequences are some of the main challenges in plant proteomics. However, the latter is now changing with several genomes emerging for model plants and crops such as potato, tomato, soybean, rice, maize and barley. This review discusses the current status in quantitative plant proteomics (MS-based and non-MS-based) and its challenges and potentials. Both relative and absolute quantitation methods in plant proteomics from DIGE to MS-based analysis after isotope labeling and label-free quantitation are described and illustrated by published studies. In particular, we describe plant-specific quantitative methods such as metabolic labeling methods that can take full advantage of plant metabolism and culture practices, and discuss other potential advantages and challenges that may arise from the unique properties of plants.

  13. Quantitative nuclear hepatology

    SciTech Connect

    Gilbert, S.A.; Brown, P.H.; Krishnamurthy, G.T.

    1987-03-01

    This is the first in a series of four Continuing Education articles on quantitative imaging techniques. After studying this article, the reader should be able to: 1) compare the radiopharmaceuticals available for hepatobiliary imaging; 2) discuss quantitation of hepatobiliary studies; and 3) discuss the clinical applications of these techniques.

  14. [Structure and function of the factor VIII/von Willebrand factor complex].

    PubMed

    Müller, G

    1990-03-01

    In the blood plasma factor VIII is bound to the von Willebrand factor. The primary structure of the two proteins were clarified by gene clonation. Factor VIII descends from a precursor protein with 2,351 amino acids by splitting of 19 amino acid residues and is activated by partial proteolysis. In the blood coagulation factor VIII acts as co-factor for the activation of factor X by factor IX in the presence of phospholipids and Ca++ within the intrinsic coagulation system. The formation of the von Willebrand factor takes place by splitting of 22 and 741 amino acid residues, respectively, from pre-pro-von Willebrand factor via pro-von Willebrand factor. The subunits of the von Willebrand factor consist od 2,050 amino acid residues. In the blood plasma the von Willebrand factor is existing as a mixture of multimeres. Receptors of the von Willebrand factor on the thrombocytic membrane are the glycoproteins GPIb and GPIIb/GPIIIa, by means of which the adhesion of thrombocytes at the subendoethelium of the vascular wall and the aggregation of thrombocytes are mediated.

  15. Application of von Mises criterion to single and dual phase TiAl

    SciTech Connect

    Goo, E.

    1998-05-05

    The von Mises criterion is a necessary condition for ductility in polycrystalline solids. Methods for determining whether a set of slip system satisfies the von Mises criterion are well established and presented in many textbooks. Determining if a set of twinning systems satisfies the von Mises criterion is complicated by the fact that twinning is unidirectional as opposed to slip which is bidirectional. Twinning occurs when the shear occurs in one direction and reversing the direction of the shear will not produce a twin and therefore twinning is unidirectional. A method has been devised for determining if a set of twin systems satisfies the von Mises criterion. This method is actually a more general method that is also applicable to slip as well as twinning because it makes no assumption of bidirectionality. In this paper it is shown what slip and twin systems observed in TiAl and Ti{sub 3}Al are needed to satisfy the von Mises criterion. It is also shown that the von Mises criterion may be applied to a two-phase alloy where there exist an orientation relationship, the von Mises criterion is satisfied.

  16. Is the activated partial thromboplastin time suitable to screen for von Willebrand factor deficiencies?

    PubMed

    Lippi, Giuseppe; Franchini, Massimo; Poli, Giovanni; Salvagno, Gian Luca; Montagnana, Martina; Guidi, Gian Cesare

    2007-06-01

    The diagnostic approach to von Willebrand factor deficiencies is challenging and requires discretionary use of laboratory resources. Although extensive preoperative testing is not recommended, the activated partial thromboplastin time may be useful, especially in selected categories of patients. To establish the diagnostic sensitivity of this test to identify isolate von Willebrand factor deficiencies, 204 consecutive patients underwent a routine preoperative screening consisting of activated partial thromboplastin time, von Willebrand factor antigen, intrinsic pathway clotting factors activity, lupus anticoagulants and thrombin time. Thirty-seven patients were diagnosed with haemostasis disturbances other than von Willebrand factor deficiencies and were excluded from the evaluation. Isolated von Willebrand factor deficiency was diagnosed in 11 of the remaining 167 patients. A significant correlation was observed between von Willebrand factor antigen and activated partial thromboplastin time. Receiver operating characteristic curve analysis showed an area under the curve of 0.982 (95% confidence interval: 0.972-0.992; P < 0.001). At the 1.17 upper limit of the activated partial thromboplastin time, sensitivity and specificity were 100 and 85%, respectively, with negative and positive predictive values of 100 and 31%, respectively. These results demonstrate that activated partial thromboplastin time has an excellent diagnostic sensitivity and a satisfactory specificity for identifying isolated von Willebrand factor deficiencies.

  17. Platelet-independent adhesion of calcium-loaded erythrocytes to von Willebrand factor

    PubMed Central

    Bierings, Ruben; Meems, Henriet; Mul, Frederik P. J.; Geerts, Dirk; Vlaar, Alexander P. J.; Voorberg, Jan; Hordijk, Peter L.

    2017-01-01

    Adhesion of erythrocytes to endothelial cells lining the vascular wall can cause vaso-occlusive events that impair blood flow which in turn may result in ischemia and tissue damage. Adhesion of erythrocytes to vascular endothelial cells has been described in multiple hemolytic disorders, especially in sickle cell disease, but the adhesion of normal erythrocytes to endothelial cells has hardly been described. It was shown that calcium-loaded erythrocytes can adhere to endothelial cells. Because sickle erythrocyte adhesion to ECs can be enhanced by ultra-large von Willebrand factor multimers, we investigated whether calcium loading of erythrocytes could promote binding to endothelial cells via ultra-large von Willebrand factor multimers. We used (immunofluorescent) live-cell imaging of washed erythrocytes perfused over primary endothelial cells at venular flow rate. Using this approach, we show that calcium-loaded erythrocytes strongly adhere to histamine-stimulated primary human endothelial cells. This adhesion is mediated by ultra-large von Willebrand factor multimers. Von Willebrand factor knockdown or ADAMTS13 cleavage abolished the binding of erythrocytes to activated endothelial cells under flow. Platelet depletion did not interfere with erythrocyte binding to von Willebrand factor. Our results reveal platelet-independent adhesion of calcium-loaded erythrocytes to endothelium-derived von Willebrand factor. Erythrocyte adhesion to von Willebrand factor may be particularly relevant for venous thrombosis, which is characterized by the formation of erythrocyte-rich thrombi. PMID:28249049

  18. von Willebrand factor binds to the surface of dendritic cells and modulates peptide presentation of factor VIII

    PubMed Central

    Sorvillo, Nicoletta; Hartholt, Robin B.; Bloem, Esther; Sedek, Magdalena; Brinke, Anja ten; van der Zwaan, Carmen; van Alphen, Floris P.; Meijer, Alexander B.; Voorberg, Jan

    2016-01-01

    It has been proposed that von Willebrand factor might affect factor VIII immunogenicity by reducing factor VIII uptake by antigen presenting cells. Here we investigate the interaction of recombinant von Willebrand factor with immature monocyte-derived dendritic cells using flow cytometry and confocal microscopy. Surprisingly, von Willebrand factor was not internalized by immature dendritic cells, but remained bound to the cell surface. As von Willebrand factor reduces the uptake of factor VIII, we investigated the repertoire of factor VIII presented peptides when in complex with von Willebrand factor. Interestingly, factor VIII-derived peptides were still abundantly presented on major histocompatibility complex class II molecules, even though a reduction of factor VIII uptake by immature dendritic cells was observed. Inspection of peptide profiles from 5 different donors showed that different core factor VIII peptide sequences were presented upon incubation with factor VIII/von Willebrand factor complex when compared to factor VIII alone. No von Willebrand factor peptides were detected when immature dendritic cells were pulsed with different concentrations of von Willebrand factor, confirming lack of von Willebrand factor endocytosis. Several von Willebrand factor derived peptides were recovered when cells were pulsed with von Willebrand factor/factor VIII complex, suggesting that factor VIII promotes endocytosis of small amounts of von Willebrand factor by immature dendritic cells. Taken together, our results establish that von Willebrand factor is poorly internalized by immature dendritic cells. We also show that von Willebrand factor modulates the internalization and presentation of factor VIII-derived peptides on major histocompatibility complex class II. PMID:26635035

  19. [Ernst von der Porten : looking for facts before and after forced emigration].

    PubMed

    Goerig, M; Bruijn, L

    2014-10-01

    The Ernst von der Porten medal has been awarded for many years to exceptional personalities by the Alliance of German Anesthesiologists to honor the outstanding achievements of the physician Ernst von der Porten from Hamburg in the development of anesthesiology as an autonomous discipline Only recent access to hitherto inaccessible documents enabled the reconstruction of his final years. He was persecuted and excluded by the National Socialist (NS) regime due to his Jewish roots and finally forced to emigrate. Records revealed that even in the so-called safe exile, degrading treatment and humiliation continued for Ernst von der Porten and his family. He eventually evaded this situation by committing suicide.

  20. [Carl Friedrich von Weizsäcker - a doctoral candidate's recollection].

    PubMed

    Lüst, Reimar

    2014-01-01

    The author and Sebastian von Hoerner was not only Carl Friedrich von Weizsäcker's first doctoral advisee and graduate but the lives and work of Lüst and Weizsäcker were otherwise also interconnected in various ways--for example, the author's term as president of the Max Planck Society coincided with the closing of the Institute at Starnberg. The present contribution attempts to sketch a (subjectively influenced) portrait of the person and scholar Carl Friedrich von Weizsäcker from the perspective of his years at Göttingen.

  1. [Scientific theoretical founding of medicine as a natural science by Hermann von Helmholtz (1821-1894)].

    PubMed

    Neumann, J N

    1994-01-01

    In this study an attempt will be made to discuss the epistemological problems in the theory and practice of modern technical medicine in the writings of Hermann von Helmholz. An inquiry into the relationship between von Helmholtz' thinking and the critical philosophy of Immanuel Kant is followed by the characteristics of von Helmholtz' philosophy of science which he himself called "empirical theory". The question of medicine as a science finally leads to the main problem of medical epistemology, viz., the relationship between theoretical knowledge and practice in medicine. In this context the anthropological dimension is brought into consideration.

  2. Das Assessment von Vulnerabilitäten, Risiken und Unsicherheiten

    NASA Astrophysics Data System (ADS)

    Birkmann, Jörn; Greiving, Stefan; Serdeczny, Olivia Maria

    Die Risiken und möglichen Folgen des Klimawandels für Menschen, Produktions- und Ökosysteme sind eng mit sozioökonomischen Entwicklungen und Rahmenbedingungen verflochten. Die Schlüsselbegriffe "Vulnerabilität", "Risiko" und "Unsicherheit" werden näher beleuchtet, um u. a. deutlich zu machen, wie sie im neueren Risikoansatz des Fünften Sachstandsberichts (AR5) des Weltklimarats (IPCC) genutzt werden. Das Risikokonzept wird vom Vulnerabilitätskonzept unterschieden. In den Fokus rückt die Betrachtung von Gefahr und Exposition. Auch die Frage, was unter Unsicherheit und Bandbreiten möglicher Entwicklungen des Klimas und sogenannter sozioökonomischer Entwicklungspfade zu verstehen ist, spielt dabei eine wichtige Rolle. Bisherige Untersuchungsmethoden zu Risiken im Kontext des Klimawandels und darauf aufbauende Entscheidungsprozesse werden im Hinblick auf künftige Anpassungsmaßnahmen diskutiert.

  3. A Powerful Friendship: Theodore von Karman and Hugh L. Dryden

    NASA Technical Reports Server (NTRS)

    Gorn, Michael

    2003-01-01

    During their long personal friendship and professional association, Theodore von Karman (1882-1963) and Hugh L. Dryden (1898-1965) exercised a pivotal if somewhat elusive influence over American aeronautics and spaceflight. Both decisive figures in organizing scientists and engineers at home and abroad, both men of undisputed eminence in their technical fields, their range of contacts in government, academia, the armed forces, industry, and professional societies spanned the globe to an extent unparalleled then as now. Moreover, because they coordinated their activities closely, their combined influence far exceeded the sum of each one s individual contributions. This paper illustrates their personal origins as well as the foundations of their friendship, how their relationship became a professional alliance, and their joint impact on the world of aeronautics and astronautics during the twentieth century.

  4. ADAMTS13 and von Willebrand factor in thrombotic thrombocytopenic purpura.

    PubMed

    Zheng, X Long

    2015-01-01

    Pathogenesis of thrombotic thrombocytopenic purpura (TTP) was a mystery for over half a century until the discovery of ADAMTS13. ADAMTS13 is primarily synthesized in the liver, and its main function is to cleave von Willebrand factor (VWF) anchored on the endothelial surface, in circulation, and at the sites of vascular injury. Deficiency of plasma ADAMTS13 activity (<10%) resulting from mutations of the ADAMTS13 gene or autoantibodies against ADAMTS13 causes hereditary or acquired (idiopathic) TTP. ADAMTS13 activity is usually normal or modestly reduced (>20%) in other forms of thrombotic microangiopathy secondary to hematopoietic progenitor cell transplantation, infection, and disseminated malignancy or in hemolytic uremic syndrome. Plasma infusion or exchange remains the initial treatment of choice to date, but novel therapeutics such as recombinant ADAMTS13 and gene therapy are under development. Moreover, ADAMTS13 deficiency has been shown to be a risk factor for the development of myocardial infarction, stroke, cerebral malaria, and preeclampsia.

  5. Von Glaserfeld`s Radical Constructivism: A Critical Review

    NASA Astrophysics Data System (ADS)

    Hardy, Michael D.

    We explore Ernst von Glaserfelds radical constructivism, its criticisms, and our own thoughts on what it promises for the reform of science and mathematics teaching. Our investigation reveals that many criticisms of radical constructivism are unwarranted; nevertheless, in its current cognitivist form radical constructivism may be insufficient to empower teachers to overcome objectivist cultural traditions. Teachers need to be empowered with rich understandings of philosophies of science and mathematics that endorse relativist epistemologies; for without such they are unlikely to be prepared to reconstruct their pedagogical practices. More importantly, however, is a need for a powerful social epistemology to serve as a referent for regenerating the culture of science education. We recommend blending radical constructivism with Habermas theory of communicative action to provide science teachers with a moral imperative for adopting a constructivist epistemology.

  6. Canary Island Group and von Karman Cloud Vortices.

    NASA Image and Video Library

    1991-06-14

    STS040-75-003 (5-14 June 1991) --- This image shows several of the Canary Islands, located in the North Atlantic Ocean just west of Africa. Low level stratus clouds often form here (and along the west coast of continents at these latitudes) are trapped in vertical movement due to an overlying atmospheric temperature inversion. The islands are generating disturbances in the low-level wind flow which is generally from the north-northeast or from top to bottom in the image. These disturbances travel downstream from the islands and manifest themselves as cloud swirls which are called von Karman vortices. The northern extent of a large dust storm moving off the coast of Africa is apparent at the lower right of the image. The dust, extended across the Atlantic Ocean as far west as the Dominican Republic later in the mission.

  7. Using genetic diagnostics in hemophilia and von Willebrand disease.

    PubMed

    Swystun, Laura L; James, Paula

    2015-01-01

    Most bleeding disorders encountered in clinical practice will be diagnosed, at least initially, by phenotypic assays. However, since the characterization of the genes that encode coagulation factors in the 1980s, significant progress has been made in translating this knowledge for diagnostic and therapeutic purposes. For hemophilia A and B, molecular genetic testing to determine carrier status, prenatal diagnosis, and likelihood of inhibitor development or anaphylaxis to infused coagulation factor concentrates is an established component of comprehensive clinical management. In contrast, although significant recent advances in our understanding of the molecular genetic basis of von Willebrand disease (VWD) have allowed for the development of rational approaches to genetic diagnostics, questions remain about this complex genetic disorder and how to incorporate emerging knowledge into diagnostic strategies. This article will review the state-of-the-art for molecular diagnostics for both hemophilia and VWD.

  8. The role of von Willebrand factor in thrombus formation.

    PubMed

    Ruggeri, Zaverio M

    2007-01-01

    Von Willebrand factor (VWF) is a large multimeric glycoprotein produced in endothelial cells and megakaryocytes and present in subendothelial matrix, blood plasma and platelets. VWF mediates adhesion and aggregation of platelets at sites of vascular injury, processes that are critical for both haemostasis and thrombosis. Thrombus formation involves complex events that are influenced by different environmental conditions. Progress in understanding the structure and function of VWF and the mechanisms that underlie its interactions with platelets has led to important insight into the differentiation between normal haemostasis and pathological arterial thrombosis. The conventional view of signalling-induced platelet aggregation has recently been extended to include activation-independent aggregation. A novel mechanism has been demonstrated for initiating thrombus formation under high haemodynamic forces that involves alpha(IIb)beta(3)-independent platelet aggregation at the interface between immobilised and soluble VWF. This VWF-mediated process may be a key determinant of platelet accumulation in stenotic arteries leading to acute thrombotic occlusion.

  9. Stochastic von Bertalanffy models, with applications to fish recruitment.

    PubMed

    Lv, Qiming; Pitchford, Jonathan W

    2007-02-21

    We consider three individual-based models describing growth in stochastic environments. Stochastic differential equations (SDEs) with identical von Bertalanffy deterministic parts are formulated, with a stochastic term which decreases, remains constant, or increases with organism size, respectively. Probability density functions for hitting times are evaluated in the context of fish growth and mortality. Solving the hitting time problem analytically or numerically shows that stochasticity can have a large positive impact on fish recruitment probability. It is also demonstrated that the observed mean growth rate of surviving individuals always exceeds the mean population growth rate, which itself exceeds the growth rate of the equivalent deterministic model. The consequences of these results in more general biological situations are discussed.

  10. Implementing the Quantum von Neumann Architecture with Superconducting Circuits

    NASA Astrophysics Data System (ADS)

    Mariantoni, Matteo; Wang, H.; Yamamoto, T.; Neeley, M.; Bialczak, Radoslaw C.; Chen, Y.; Lenander, M.; Lucero, Erik; O'Connell, A. D.; Sank, D.; Weides, M.; Wenner, J.; Yin, Y.; Zhao, J.; Korotkov, A. N.; Cleland, A. N.; Martinis, John M.

    2011-10-01

    The von Neumann architecture for a classical computer comprises a central processing unit and a memory holding instructions and data. We demonstrate a quantum central processing unit that exchanges data with a quantum random-access memory integrated on a chip, with instructions stored on a classical computer. We test our quantum machine by executing codes that involve seven quantum elements: Two superconducting qubits coupled through a quantum bus, two quantum memories, and two zeroing registers. Two vital algorithms for quantum computing are demonstrated, the quantum Fourier transform, with 66% process fidelity, and the three-qubit Toffoli-class OR phase gate, with 98% phase fidelity. Our results, in combination especially with longer qubit coherence, illustrate a potentially viable approach to factoring numbers and implementing simple quantum error correction codes.

  11. Stochastic resonance in a generalized Von Foerster population growth model

    SciTech Connect

    Lumi, N.; Mankin, R.

    2014-11-12

    The stochastic dynamics of a population growth model, similar to the Von Foerster model for human population, is studied. The influence of fluctuating environment on the carrying capacity is modeled as a multiplicative dichotomous noise. It is established that an interplay between nonlinearity and environmental fluctuations can cause single unidirectional discontinuous transitions of the mean population size versus the noise amplitude, i.e., an increase of noise amplitude can induce a jump from a state with a moderate number of individuals to that with a very large number, while by decreasing the noise amplitude an opposite transition cannot be effected. An analytical expression of the mean escape time for such transitions is found. Particularly, it is shown that the mean transition time exhibits a strong minimum at intermediate values of noise correlation time, i.e., the phenomenon of stochastic resonance occurs. Applications of the results in ecology are also discussed.

  12. Alexander von Humboldt's perceptions of colonial Spanish America.

    PubMed

    Rebok, Sandra

    2009-01-01

    This study presents an in-depth analysis of Alexander von Humboldt's descriptions and critical comments on the colonial society of the different regions he visited during his well-known expedition through the Americas (1799-1804). The criticisms of colonialism that he expressed, reflecting his personal convictions, have already been the focal point of many studies, but Humboldt also was able to offer a more differentiated assessment through comparisons of regional and local traditions and developments. This essay focuses on his personal diaries, which offer many interesting comments on colonial societies. These considerations and impressions made during the expedition are of particular scholarly value since they were not subject to censorship of any kind.

  13. Ludwig von Bertalanffy's organismic view on the theory of evolution.

    PubMed

    Drack, Manfred

    2015-03-01

    Ludwig von Bertalanffy was a key figure in the advancement of theoretical biology. His early considerations already led him to recognize the necessity of considering the organism as a system, as an organization of parts and processes. He termed the resulting research program organismic biology, which he extended to all basic questions of biology and almost all areas of biology, hence also to the theory of evolution. This article begins by outlining the rather unknown (because often written in German) research of Bertalanffy in the field of theoretical biology. The basics of the organismic approach are then described. This is followed by Bertalanffy's considerations on the theory of evolution, in which he used methods from theoretical biology and then introduced his own, organismic, view on evolution, leading to the demand for finding laws of evolution. Finally, his view on the concept of homology is presented. © 2015 Wiley Periodicals, Inc.

  14. Voluntarism in early psychology: the case of Hermann von Helmholtz.

    PubMed

    De Kock, Liesbet

    2014-05-01

    The failure to recognize the programmatic similarity between (post-)Kantian German philosophy and early psychology has impoverished psychology's historical self-understanding to a great extent. This article aims to contribute to recent efforts to overcome the gaps in the historiography of contemporary psychology, which are the result of an empiricist bias. To this end, we present an analysis of the way in which Hermann von Helmholtz's theory of perception resonates with Johann Gottlieb Fichte's Ego-doctrine. It will be argued that this indebtedness is particularly clear when focusing on the foundation of the differential awareness of subject and object in perception. In doing so, the widespread reception of Helmholtz's work as proto-positivist or strictly empiricist is challenged, in favor of the claim that important elements of his theorizing can only be understood properly against the background of Fichte's Ego-doctrine. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  15. Franz von Leydig (1821-1908), pioneer of comparative histology.

    PubMed

    Schneider, Marlon R

    2012-05-01

    Franz von Leydig, a German histologist and zoologist, is known to every student of human or animal anatomy because of the testicular testosterone-producing cells carrying his name. However, he made many contributions to our knowledge of the fine structure of animal tissues, including more than 200 scientific articles and several books. His most important work, the book Lehrbuch der Histologie des Menschen und der Thiere, established him as a pioneer if not the founder of comparative histology. Leydig taught at three different universities (Würzburg, Tübingen and Bonn) and received many honours from scientific organizations worldwide, including the Royal Society. He died in Rothenburg ob der Tauber, the town of his birth, aged 86 years.

  16. Quantitation of TCE-Induced Radicals in Liver of B6C3Fl Mice In Vivo: An EPR Study

    DTIC Science & Technology

    1996-02-01

    broken down chemically by aqueous peroxides, or biologically by monoxygenase enzymes, such as those found in soil microrganisms (von Sonntag and...lipid peroxidation measured by analysis of thiobarbituric acid reactive substance (Fraga et al., 1988). For this report our aim was to quantitate, by...adding the same amount of PBN spin trap to the mice and that the nitrone was not degrading spontaneously and was not contaminated . Mice were

  17. Alpha granule proteins in type I von Willebrand's disease.

    PubMed

    McKeown, L P; Williams, S B; Shafer, B; Murray, N; Gralnick, H R

    1993-02-01

    Platelet von Willebrand factor (vWf) is located in the alpha granules. Individuals with type I von Willebrand's disease (vWd) with prolonged bleeding times are best discriminated from those who have normal bleeding times by the normal level of platelet vWf ristocetin cofactor activity (vWf activity) and, to a lesser extent, by their platelet vWf antigen content. We have studied the content of adhesive proteins and platelet factor-4 (PF-4), and beta-thromboglobulin (beta TG) in the platelet alpha granules of types I and III vWd patients to determine if other alterations in alpha granule contents of proteins occur in vWd. We found that type I vWd patients with prolonged or normal bleeding times could not be differentiated on the basis of their platelet levels of beta TG, PF-4, fibronectin, or fibrinogen. The levels of the alpha granule constituents in the type I vWd patient were similar to normal except for the platelet fibrinogen concentration. Patients with type I vWd, regardless of the level of platelet vWf activity of antigen, had increased levels of platelet fibrinogen. The patients with type III vWd who had undetectable levels of platelet and plasma vWf also had increased levels of platelet fibrinogen. In our study we could not attribute the variation in the platelet vWf activity and antigen in type I vWd to the size of the alpha granule pool as determined by the measurement of other alpha granule proteins. The mechanism(s) of increased platelet fibrinogen in these vWd patients is at present unknown.

  18. Dynamics of Diffusion Flames in von Karman Swirling Flows Studied

    NASA Technical Reports Server (NTRS)

    Nayagam, Vedha; Williams, Forman A.

    2002-01-01

    Von Karman swirling flow is generated by the viscous pumping action of a solid disk spinning in a quiescent fluid media. When this spinning disk is ignited in an oxidizing environment, a flat diffusion flame is established adjacent to the disk, embedded in the boundary layer (see the preceding illustration). For this geometry, the conservation equations reduce to a system of ordinary differential equations, enabling researchers to carry out detailed theoretical models to study the effects of varying strain on the dynamics of diffusion flames. Experimentally, the spinning disk burner provides an ideal configuration to precisely control the strain rates over a wide range. Our original motivation at the NASA Glenn Research Center to study these flames arose from a need to understand the flammability characteristics of solid fuels in microgravity where slow, subbuoyant flows can exist, producing very small strain rates. In a recent work (ref. 1), we showed that the flammability boundaries are wider and the minimum oxygen index (below which flames cannot be sustained) is lower for the von Karman flow configuration in comparison to a stagnation-point flow. Adding a small forced convection to the swirling flow pushes the flame into regions of higher strain and, thereby, decreases the range of flammable strain rates. Experiments using downward facing, polymethylmethacrylate (PMMA) disks spinning in air revealed that, close to the extinction boundaries, the flat diffusion flame breaks up into rotating spiral flames (refs. 2 and 3). Remarkably, the dynamics of these spiral flame edges exhibit a number of similarities to spirals observed in biological systems, such as the electric pulses in cardiac muscles and the aggregation of slime-mold amoeba. The tail of the spiral rotates rigidly while the tip executes a compound, meandering motion sometimes observed in Belousov-Zhabotinskii reactions.

  19. 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.

  20. [Reference relationships between human and animal in Hildegard von Bingen].

    PubMed

    Riethe, Peter

    2012-01-01

    In "De animalibus", the 7th book in the "Liber simplicis medicinae", Hildegard von Bingen describes the characteristics of four-footed land animals. Some of these have a special relationship with humans in that they embody moral qualities. An explanation for this is already given in the preface, which states that human intelligence recognizes these qualities, declaring that "You are this or that sort of creature". Since the relationship that animals have with nature shares a degree of similarity with that of man's, they can be regarded as symbolic representatives for particular human traits and characteristics. The article at hand presents Hildegard von Bingen's descriptions of the monkey, the lion, the bear, the rabbit, the dog, the cat, the wolf, the lynx, and the donkey. While the monkey just mimics man's behaviour and is imperfect in both settings, the lion embodies will power. The bear on the other hand stands for unbridled sexual desire, while in the rabbit the gentleness of a sheep is united with the bounce of a deer. The lynx is regarded as hedonistic, the donkey as stupid, and the wolf as surrounded by dangerous sylphs. In Hildegard's depictions, exotic and native animal species display rather extraordinary behavioural traits, and the medieval Christian world view of the author conveys unexpected relationships between humans and animals. In addition to empirical observation and experience, Hildegard also relies on folkloristic beliefs and magical practices related to explanatory models of her time. She allows largely unknown sources into her animal lore but never strays from her ultimate goal of having it serve to instruct people. In doing so, Hildegard removed herself far from the common tradition of medieval animal portraits.

  1. Terminal platelet production is regulated by von Willebrand factor.

    PubMed

    Poirault-Chassac, Sonia; Nguyen, Kim Anh; Pietrzyk, Audrey; Casari, Caterina; Veyradier, Agnes; Denis, Cecile V; Baruch, Dominique

    2013-01-01

    It is established that proplatelets are formed from mature megakaryocytes (MK) as intermediates before platelet production. Recently, the presence of proplatelets was described in blood incubated in static conditions. We have previously demonstrated that platelet and proplatelet formation is upregulated by MK exposure to high shear rates (1800 s(-1)) on immobilized von Willebrand factor (VWF). The purpose of the present study was to investigate whether VWF is involved in the regulation of terminal platelet production in blood. To this end, Vwf (-/-) mice, a model of severe von Willebrand disease, were used to create a situation in which blood cells circulate in a vascular tree that is completely devoid of VWF. Murine platelets were isolated from Vwf (-/-) and Vwf (+/+) blood, exposed to VWF at 1800 s(-1) in a microfluidic platform, and examined by means of videomicroscopy, as well as fluorescence and activation studies. Proplatelets became visible within 5 minutes, representing 38% of all platelets after 12 minutes and 46% after 28 min. The proportion of proplatelets was 1.8-fold higher in blood from Vwf(-/-) mice than from Vwf(+/+) mice, suggesting a role of VWF in vivo. Fragmentation of these proplatelets into smaller discoid platelets was also observed in real-time. Platelets remained fully activatable by thrombin. Compensation of plasmatic VWF following hydrodynamic gene transfer in Vwf(-/-) mice reduced the percentage of proplatelets to wild-type levels. A thrombocytopenic mouse model was studied in the flow system, 7 days after a single 5-FU injection. Compared to untreated mouse blood, a 2-fold increase in the percentage of proplatelets was detected following exposure to 1800 s(-1) on VWF of samples from mice treated with 5-FU. In conclusion, VWF and shear stress together appear to upregulate proplatelet reorganization and platelet formation. This suggests a new function for VWF in vivo as regulator of bloodstream thrombopoiesis.

  2. John von Neumann and Klaus Fuchs: an Unlikely Collaboration

    NASA Astrophysics Data System (ADS)

    Bernstein, Jeremy

    2010-03-01

    I discuss the origin of the idea of making a fusion (hydrogen) bomb and the physics involved in it, and then turn to the design proposed for one by the unlikely collaborators John von Neumann and Klaus Fuchs in a patent application they filed at Los Alamos in May 1946, which Fuchs passed on to the Russians in March 1948, and which with substantial modifications was tested on the island of Eberiru on the Eniwetok atoll in the South Pacific on May 8, 1951. This test showed that the fusion of deuterium and tritium nuclei could be ignited, but that the ignition would not propagate because the heat produced was rapidly radiated away. Meanwhile, Stanislaw Ulam and C.J. Everett had shown that Edward Teller’s Classical Super could not work, and at the end of December 1950, Ulam had conceived the idea of super compression, using the energy of a fission bomb to compress the fusion fuel to such a high density that it would be opaque to the radiation produced. Once Teller understood this, he invented a greatly improved, new method of compression using radiation, which then became the heart of the Ulam-Teller bomb design, which was tested, also in the South Pacific, on November 1, 1952. The Russians have freely acknowledged that Fuchs gave them the fission bomb, but they have insisted that no one gave them the fusion bomb, which grew out of design involving a fission bomb surrounded by alternating layers of fusion and fission fuels, and which they tested on November 22, 1955. Part of the irony of this story is that neither the American nor the Russian hydrogen-bomb programs made any use of the brilliant design that von Neumann and Fuchs had conceived as early as 1946, which could have changed the entire course of development of both programs.

  3. [Rhinoplasty in a patient with Von Willebrand disease: case report.].

    PubMed

    Matos Junior, Roberto Martins; Godoy, Rogério da Costa; Gobbo, Mônica da Cunha; Lian Junior, João; Duz, Gilson Luis

    2007-12-01

    Patients with von Willebrand disease present abnormal bleeding after being wounded or during surgeries since it affects primary and secondary hemostasia due to changes in factor VIII. The objective of this report was to elucidate the pre-, peri-, and postoperative management of patients with this disorder. A 42-year old white female, with 165 cm, 61 kg, ASA II, with a diagnosis of type 1 von Willebrand disease, underwent pre-anesthetic evaluation for rhinoplasty. She was cleared for surgery after hematological evaluation with a positive DDAVP IN26 test. On the day of the surgery, the patient received pre-anesthetic medication, was adequately monitored, oxygen was administered through a nasal cannula and intravenous desmopressin (0.4 microg.kg-1 in 100 mL of normal saline) was administered 30 minutes before the surgery. Induction was accomplished with intravenous sufentanil (1 microg.kg-1), propofol (4 mg.kg-1), and rocuronium (0.6 mg.kg-1). The patient was intubated and installed on mechanical ventilation with a CO2 absorber system and maintenance consisted of O2, N2O and sevoflurane. The surgery lasted 90 minutes. During the surgery the patient remained hemodynamically stable with negligible blood loss. Infusion of cryoprecipitate or plasma, used in the prophylaxis and treatment of bleeding complications, produces peak concentrations of factor VIII after 48 hours and it is sustained for 72 hours; however, even though it has been approved by the FDA this has been used only in emergencies due to the relative risk of viral contamination. 1-Deamino-8-D-arginine vasopressin (DDAVP-desmopressin) increases the concentration of factor VIII besides eliminating exposure to blood borne pathogens and it has the possibility of being administered by the nose, subcutaneous, and intravenous.

  4. Acquired von Willebrand syndrome in children with aorticand pulmonary stenosis

    PubMed Central

    Binnetoğlu, Fatih Köksal; Babaoğlu, Kadir; Filiz, Şayegan Güven; Zengin, Emine; Sarper, Nazan; Altun, Gürkan; Kılıç, Suar Çakı

    2016-01-01

    Summary Introduction: This prospective study was planned to investigate the frequency and relationship of acquired von Willebrand syndrome (AVWS) with aortic and pulmonary stenosis in patients. Methods: A total of 84 children, ranging from two to 18 years of age, were enrolled in this study. Of these, 28 had isolated aortic stenosis, 32 had isolated pulmonary stenosis and 24 were healthy. Children with aortic and pulmonary stenosis associated with other congenital heart diseases were excluded. Children with hypothyroidism, renal or liver disease, malignancy or autoimmune disease were also excluded. Wholeblood count, blood group, factor VIII level, prothrombin time (PT), activated partial thromboplastin time (aPTT), von Willebrand factor antigen (VWF:Ag), ristocetin co-factor (VWF:RCo), and bleeding time using a platelet-function analyser (PFA-100) were performed in all patients. All of the children in the study underwent a detailed physical examination and echocardiographic evaluation. Results: A history of bleeding was positive in 18% of the aortic stenosis group, 9% of the pulmonary stenosis group, and 4% of the control group. Seven of 60 (12%) patients had laboratory findings that implied a diagnosis of AVWS, and two of these (28%) had a history of bleeding. The frequency of AVWS was 14% in patients with aortic stenosis and 9% in those with pulmonary stenosis. Conclusion: AVWS is not rare in stenotic obstructive cardiac diseases. A detailed history of bleeding should be taken from patients with valvular disease. Even if the history is negative, whole blood count, PT and aPTT should be performed. If necessary, PFA-100 closure time and further tests should be planned for the diagnosis of AVWS. PMID:27841910

  5. Evaluation of von Willebrand factor phenotypes and genotypes in Hemophilia A patients with and without identified F8 mutations

    PubMed Central

    Boylan, Brian; Rice, Anne S.; De Staercke, Christine; Eyster, M. Elaine; Yaish, Hassan M.; Knoll, Christine M.; Bean, Christopher J.; Miller, Connie H.

    2015-01-01

    Summary Background Hemophilia A (HA) is an X-linked bleeding disorder caused by a deficiency in factor VIII (FVIII). von Willebrand disease (VWD) is characterized by a quantitative or qualitative defect in von Willebrand Factor (VWF). Patients with VWD with severely low VWF or VWD Type 2N (VWD2N), a VWD subtype distinguished by defective VWF binding to FVIII, may have reduced FVIII levels secondary to their VWD. These patients superficially resemble patients with HA, and pose a potential for misdiagnosis. Objectives Investigate the unexplained cause of bleeding in HA patients without known FVIII mutations by assessing plasma VWF antigen (VWF:Ag), FVIII binding capacities, and VWF genotypes. Patients/Methods Thirty-seven of 1027 patients with HA studied as part of the Hemophilia Inhibitor Research Study lacked identifiable F8 mutations. These patients (cases) and 73 patients with identified F8 mutations (controls) were evaluated for VWF:Ag, patient's VWF capacity to bind FVIII (VWF:FVIIIB), and VWF sequence. Results Four cases had VWF:Ag <3 IU/dL and VWF mutations consistent with Type3 VWD. Six cases and one control were heterozygous for mutations previously reported to cause Type1 VWD (VWD1) (n=5 cases and 1 control) or predicted to be deleterious by Polyphen2 and SIFT prediction tools (n=1 case). One control had VWF:Ag <30 IU/dl, and seven patients (4 cases and 3 controls), including two cases who were heterozygous for a known VWD2N mutation, had reduced VWF:FVIIIB. Conclusions These data emphasize that some patients diagnosed with HA require VWF assessments in order to achieve a comprehensive diagnosis and an optimal treatment strategy. PMID:25780857

  6. Evaluation of von Willebrand factor phenotypes and genotypes in Hemophilia A patients with and without identified F8 mutations.

    PubMed

    Boylan, B; Rice, A S; De Staercke, C; Eyster, M E; Yaish, H M; Knoll, C M; Bean, C J; Miller, C H

    2015-06-01

    Hemophilia A (HA) is an X-linked bleeding disorder caused by a deficiency in factor VIII (FVIII). von Willebrand disease (VWD) is characterized by a quantitative or qualitative defect in von Willebrand factor (VWF). Patients with VWD with severely low VWF or VWD Type 2N (VWD2N), a VWD subtype distinguished by defective VWF binding to FVIII, may have reduced FVIII levels secondary to their VWD. These patients superficially resemble patients with HA and pose a potential for misdiagnosis. To investigate the unexplained cause of bleeding in HA patients without known FVIII mutations by assessing plasma VWF antigen (VWF:Ag), FVIII binding capacities and VWF genotypes. Thirty-seven of 1027 patients with HA studied as part of the Hemophilia Inhibitor Research Study lacked identifiable F8 mutations. These patients (cases) and 73 patients with identified F8 mutations (controls) were evaluated for VWF:Ag, a patient's VWF capacity to bind FVIII (VWF:FVIIIB) and VWF sequence. Four cases had VWF:Ag < 3 IU dL(-1) and VWF mutations consistent with Type 3 VWD. Six cases and one control were heterozygous for mutations previously reported to cause Type 1 VWD (VWD1) (n = five cases and one control) or predicted to be deleterious by Polyphen2 and SIFT prediction tools (n = 1 case). One control had VWF:Ag < 30 IU dL(-1) and seven patients (four cases and three controls), including two cases who were heterozygous for a known VWD2N mutation, had reduced VWF:FVIIIB. These data emphasize that some patients diagnosed with HA require VWF assessments in order to achieve a comprehensive diagnosis and an optimal treatment strategy. © 2015 International Society on Thrombosis and Haemostasis.

  7. Postpartum von Willebrand factor levels in women with and without von Willebrand disease and implications for prophylaxis.

    PubMed

    James, A H; Konkle, B A; Kouides, P; Ragni, M V; Thames, B; Gupta, S; Sood, S; Fletcher, S K; Philipp, C S

    2015-01-01

    The aim of this study was to elucidate the fall in von Willebrand factor (VWF) and factor VIII activity (FVIII) after childbirth in women with and without von Willebrand disease (VWD). VWF:RCo, VWF:Ag, and FVIII were obtained in the third trimester of pregnancy, on admission for childbirth, and 10 times postpartum. Specimens were processed within 4 h and analysed centrally. Means were calculated at each time point. Forty women (40 pregnancies) without VWD and 32 women (35 pregnancies) with VWD were enrolled. 15/32 with VWD were treated (30% of those with type 1 and all of those with type 2) in 17 pregnancies. Treatments prior to delivery consisted of desmopressin (2/17), VWF concentrate (15/17) and after delivery VWF concentrate (16/17). Duration of treatment was 0-21 days (median 6). VWF levels peaked at 250% of baseline--4 h postpartum in women with VWD and 12 h postpartum in women without VWD. Thereafter, VWF levels fell rapidly, approached baseline at 1 week and reached baseline at 3 weeks. Except immediately postpartum, when the levels among treated cases were higher, levels among women with VWD appeared to parallel, but were lower than those among women without VWD. Levels were lowest among those who received treatment. VWF levels fall rapidly after childbirth. Except immediately postpartum, current treatment strategies do not raise VWF levels to the levels of women without VWD or even to the levels of women with milder, untreated VWD. Consequently, women with VWD may be at risk of postpartum haemorrhage despite treatment.

  8. Diagnostic Differentiation of von Willebrand Disease Types 1 and 2 by von Willebrand Factor Multimer Analysis and DDAVP Challenge Test.

    PubMed

    Michiels, Jan Jacques; Smejkal, Petr; Penka, Miroslav; Batorova, Angelika; Pricangova, Tatiana; Budde, Ulrich; Vangenechten, Inge; Gadisseur, Alain

    2016-01-01

    The European Clinical Laboratory and Molecular (ECLM) classification of von Willebrand disease (vWD) is based on the splitting approach which uses sensitive and specific von Willebrand factor (vWF) assays with regard to the updated molecular data on structure and function of vWF gene and protein defects. A complete set of FVIII:C and vWF ristocetine cofactor, collagen binding, and antigen, vWF multimeric analysis in low- and medium-resolution gels, and responses to desmopressin (DDAVP) of FVIII:C and vWF parameters are mandatory. The ECLM classification distinguishes recessive types 1 and 3 vWD from recessive vWD 2C due to mutations in the D1 and D2 domains and vWD 2N due to mutations in the D'-FVIII-binding domain of vWF. The ECLM classification differentiates between mild vWD type 1 with variable penetrance of bleedings from symptomatic dominant type 1 vWD secretion defect and/or clearance defect with normal vWF multimers versus vWD 1M and 2M with normal or smeary vWF multimers in low- and medium-resolution gels. High-quality multimeric analysis of vWF in medium-resolution gels based on a DDAVP challenge test clearly delineates and distinguishes each of the dominant type 2 vWDs 1/2E, 2M, 2B, 2A, and 2D caused by vWF gene mutations in the D3 multimerization domain, loss or gain-of-function mutations in the glycoprotein Ib receptor A1 domain, gene mutations in the A2 proteolytic domain, and the C-terminal dimerization domain, respectively.

  9. Quantitative film radiography

    SciTech Connect

    Devine, G.; Dobie, D.; Fugina, J.; Hernandez, J.; Logan, C.; Mohr, P.; Moss, R.; Schumacher, B.; Updike, E.; Weirup, D.

    1991-02-26

    We have developed a system of quantitative radiography in order to produce quantitative images displaying homogeneity of parts. The materials that we characterize are synthetic composites and may contain important subtle density variations not discernible by examining a raw film x-radiograph. In order to quantitatively interpret film radiographs, it is necessary to digitize, interpret, and display the images. Our integrated system of quantitative radiography displays accurate, high-resolution pseudo-color images in units of density. We characterize approximately 10,000 parts per year in hundreds of different configurations and compositions with this system. This report discusses: the method; film processor monitoring and control; verifying film and processor performance; and correction of scatter effects.

  10. On Quantitative Rorschach Scales.

    ERIC Educational Resources Information Center

    Haggard, Ernest A.

    1978-01-01

    Two types of quantitative Rorschach scales are discussed: first, those based on the response categories of content, location, and the determinants, and second, global scales based on the subject's responses to all ten stimulus cards. (Author/JKS)

  11. Recapturing Quantitative Biology.

    ERIC Educational Resources Information Center

    Pernezny, Ken; And Others

    1996-01-01

    Presents a classroom activity on estimating animal populations. Uses shoe boxes and candies to emphasize the importance of mathematics in biology while introducing the methods of quantitative ecology. (JRH)

  12. Quantitative receptor autoradiography

    SciTech Connect

    Boast, C.A.; Snowhill, E.W.; Altar, C.A.

    1986-01-01

    Quantitative receptor autoradiography addresses the topic of technical and scientific advances in the sphere of quantitative autoradiography. The volume opens with a overview of the field from a historical and critical perspective. Following is a detailed discussion of in vitro data obtained from a variety of neurotransmitter systems. The next section explores applications of autoradiography, and the final two chapters consider experimental models. Methodological considerations are emphasized, including the use of computers for image analysis.

  13. Multivariate Quantitative Chemical Analysis

    NASA Technical Reports Server (NTRS)

    Kinchen, David G.; Capezza, Mary

    1995-01-01

    Technique of multivariate quantitative chemical analysis devised for use in determining relative proportions of two components mixed and sprayed together onto object to form thermally insulating foam. Potentially adaptable to other materials, especially in process-monitoring applications in which necessary to know and control critical properties of products via quantitative chemical analyses of products. In addition to chemical composition, also used to determine such physical properties as densities and strengths.

  14. von Neumann's Law: Theoretical and Microgravity Experimental Comparison for Coarsening Diffusion in Bubble Lattices

    NASA Technical Reports Server (NTRS)

    Noever, David A.

    2000-01-01

    The effects of gravity in influencing the theoretical limit for bubble lattice coarsening and aging behavior, otherwise called von Neumann's law, is examined theoretically and experimentally. Preliminary microgravity results will be discussed.

  15. Dr. Wernher Von Braun leads a tour of the S-IC checkout area.

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Dr. Eberhard Rees, Charles Schultze, James Webb, Elmer Staats, Comptroller General of the United States, and Dr. Wernher Von Braun tour the S-IC checkout area in the Marshall Space Flight Center quality lab.

  16. [The Roots of Idiographic Paleontology: Karl Alfred von Zittel's Methodology and Conception of the Fossil Record].

    PubMed

    Tamborini, Marco

    2015-12-01

    This paper examines Karl Alfred von Zittel’s practice in order to uncover the roots of so-called idiographic paleontology.The great American paleontologist Stephen Jay Gould (1941–2002) defined the discipline of idiographic paleontology as illustration and description of the morphological features of extinct species. However, this approach does not investigate macroevolutionary patterns and processes. On the contrary, the paleobiological revolution of the 1970s implemented an epistemic methodology that illustrates macrovelutionary patterns and laws by combining idiographic data with a nomothetic form of explanation. This article elucidates the features of the idiographic data as well as the acquired knowledge coupled with this approach. First of all, Heinrich G. Bronn’s (1800–1862) statistical method is analyzed. Zittel’s practice arose as a reaction against the approximate conclusions reached by Bronn’s quantitative approach. Second, the details of Zittel’s methodology are described in order to bring out its peculiarities.The microscope played a pivotal role in creating and forming Zittel’s morphological data. This analysis sheds new light on the reasons behind the so-called ideographic paleontology, thus revising Gould’s historical reconstruction, as well as on the notion of paleontological data. However, even though Zittel aimed at reaching precise and stable conclusions,his data cannot be used for elucidating evolutionary mechanisms: they are scientific in a purely descriptive sense, but completely useless for biological investigations. Finally, this paper examines how Zittel’s methodology affects the contemporary paleobiological enterprise and thereby reflects upon the notion of natural history.

  17. In memory of Eugene (Jenő) von Gothard: a pioneering nineteenth century Hungarian astrophysicist

    NASA Astrophysics Data System (ADS)

    Vincze, Ildikő J.; Jankovics, István

    2012-07-01

    Eugene von Gothard was a Hungarian engineer/scientist, instrument-maker and astrophysicist who founded the Herény Astrophysical Observatory in 1881 and carried out pioneering work in astronomical photography and spectroscopy. In this paper we provide biographical material about von Gothard and describe his observatory, before discussing his astronomical observations and the contribution that hemade to the early development of astrophysics.

  18. von Brunn's Nests and Follicular Cystitis Following Intradetrusor OnabotulinumtoxinA Injections for Overactive Bladder.

    PubMed

    Nekkanti, Silpa; Doering, Andrew; Zynger, Debra L; Hundley, Andrew F

    2017-09-01

    A 67-year-old female with refractory OAB was treated with intradetrusor Botox. She subsequently developed multiple papillary bladder lesions with tissue biopsy showing Von Brunn's nests. Von Brunn's nests are benign bladder lesions similar in appearance to a rare urothelial tumor called Nested Variant of Urothelial Carcinoma (NVUC). It is critical that patients with these findings undergo evaluation to rule out the presence of carcinoma. This finding suggests the possibility of a previously unreported adverse reaction in association with intradetrusor Botox.

  19. Unconventional diagnosis of Normandy-type von Willebrand's disease in a blood donor.

    PubMed

    Kashyap, S; Nesbitt, I M; Makris, M

    2004-04-01

    We report the case of a long-standing female blood donor whose blood donation was processed for cryoprecipitate. The cryoprecipitate unit was chosen at random for FVIII:C estimation as part of the quality control, and a low FVIII:C level was identified. The cause of this was subsequently shown to be the Normandy variant of type-2 von Willebrand's disease due to a homozygous Arg854Gln mutation in the von Willebrand factor gene.

  20. von Neumann measurement-related matrices and the nullity condition for quantum correlation

    NASA Astrophysics Data System (ADS)

    Zhao, MingJing; Ma, Teng; Zhang, TingGui; Fei, Shao-Ming

    2016-12-01

    We study von Neumann measurement-related matrices, and the nullity condition of quantum correlation. We investigate the properties of these matrices that are related to a von Neumann measurement. It is shown that these ( m 2 - 1) × ( m 2 - 1) matrices are idempotent, and have rank m - 1. These properties give rise to necessary conditions for the nullity of quantum correlations in bipartite systems. Finally, as an example we discuss quantum correlation in Bell diagonal states.

  1. Markov property and strong additivity of von Neumann entropy for graded quantum systems

    SciTech Connect

    Moriya, Hajime

    2006-03-15

    The quantum Markov property is equivalent to the strong additivity of von Neumann entropy for graded quantum systems. The additivity of von Neumann entropy for bipartite graded systems implies the statistical independence of states. However, the structure of Markov states for graded systems is different from that for tensor-product systems which have trivial grading. For three-composed graded systems we have U(1)-gauge invariant Markov states whose restriction to the marginal pair of subsystems is nonseparable.

  2. Dr. von Braun with Gen. Ostrander, Dr. Rees, and Gen. Barclay

    NASA Technical Reports Server (NTRS)

    1959-01-01

    In this 1959 photo, taken at Cape Canaveral, Florida, Dr. von Braun (2nd from left) Director of the U.S. Army Ballistic Missile Agency's (ABMA) Development Operations Division, is shown conferring with Air Force Major General Donald R. Ostrander (left), on assignment at NASA as launch vehicle director; Dr. Eberhard Rees, deputy to Dr. von Braun, and Army Brigadier General John Barclay, commander of the ABMA.

  3. Fibroblast growth factor-10 signals development of von Brunn's nests in the exstrophic bladder.

    PubMed

    Eastman, Rocky; Leaf, Elizabeth M; Zhang, Dianzhong; True, Lawrence D; Sweet, Robert M; Seidel, Kristy; Siebert, Joseph R; Grady, Richard; Mitchell, Michael E; Bassuk, James A

    2010-11-01

    von Brunn's nests have long been recognized as precursors of benign lesions of the urinary bladder mucosa. We report here that von Brunn's nests are especially prevalent in the exstrophic bladder, a birth defect that predisposes the patient to formation of bladder cancer. Cells of von Brunn's nest were found to coalesce into a stratified, polarized epithelium which surrounds itself with a capsule-like structure rich in types I, III, and IV collagen. Histocytochemical analysis and keratin profiling demonstrated that nested cells exhibited a phenotype similar, but not identical, to that of urothelial cells of transitional epithelium. Immunostaining and in situ hybridization analysis of exstrophic tissue demonstrated that the FGF-10 receptor is synthesized and retained by cells of von Brunn's nest. In contrast, FGF-10 is synthesized and secreted by mesenchymal fibroblasts via a paracrine pathway that targets basal epithelial cells of von Brunn's nests. Small clusters of 10pRp cells, positive for both FGF-10 and its receptor, were observed both proximal to and inside blood vessels in the lamina propria. The collective evidence points to a mechanism where von Brunn's nests develop under the control of the FGF-10 signal transduction system and suggests that 10pRp cells may be the original source of nested cells.

  4. Fibroblast growth factor-10 signals development of von Brunn's nests in the exstrophic bladder

    PubMed Central

    Eastman, Rocky; Leaf, Elizabeth M.; Zhang, Dianzhong; True, Lawrence D.; Sweet, Robert M.; Seidel, Kristy; Siebert, Joseph R.; Grady, Richard; Mitchell, Michael E.

    2010-01-01

    von Brunn's nests have long been recognized as precursors of benign lesions of the urinary bladder mucosa. We report here that von Brunn's nests are especially prevalent in the exstrophic bladder, a birth defect that predisposes the patient to formation of bladder cancer. Cells of von Brunn's nest were found to coalesce into a stratified, polarized epithelium which surrounds itself with a capsule-like structure rich in types I, III, and IV collagen. Histocytochemical analysis and keratin profiling demonstrated that nested cells exhibited a phenotype similar, but not identical, to that of urothelial cells of transitional epithelium. Immunostaining and in situ hybridization analysis of exstrophic tissue demonstrated that the FGF-10 receptor is synthesized and retained by cells of von Brunn's nest. In contrast, FGF-10 is synthesized and secreted by mesenchymal fibroblasts via a paracrine pathway that targets basal epithelial cells of von Brunn's nests. Small clusters of 10pRp cells, positive for both FGF-10 and its receptor, were observed both proximal to and inside blood vessels in the lamina propria. The collective evidence points to a mechanism where von Brunn's nests develop under the control of the FGF-10 signal transduction system and suggests that 10pRp cells may be the original source of nested cells. PMID:20719973

  5. Eyelid retraction, lid lag, lagophthalmos, and von Graefe's sign quantifying the eyelid features of Graves' ophthalmopathy.

    PubMed

    Gaddipati, Ramakrishna V; Meyer, Dale R

    2008-06-01

    To report the frequency and relationship of eyelid retraction, lid lag, lagophthalmos, and von Graefe's sign in a group of patients with Graves' ophthalmopathy and compare these findings to those in a group of normal individuals. Retrospective comparative cohort study. Fifty consecutive Graves' ophthalmopathy patients were compared to a control group of 50 normal individuals. Measurements were made of eyelid position in primary gaze and downgaze to assess eyelid retraction and lid lag, and the presence of lagophthalmos and von Graefe's sign was noted when present. Eyelid position in primary gaze and downgaze and presence of lagophthalmos and von Graefe's sign. In the Graves' group, eyelid retraction (38%), von Graefe's sign (36%) and lagophthalmos (16%) were observed at a significantly greater frequency (P<0.01) than in normals, whereas true eyelid lag was observed in only 8% (P = 0.67). The terms lid lag and von Graefe's sign have been used interchangeably in the past; however, they are distinct signs of downgaze-related upper eyelid static position and dynamic movement, respectively. Although von Graefe's sign was commonly exibited in Graves' patients, the relatively low frequency of lid lag suggests that factors other than restriction/fibrosis are likely responsible for the etiology of eyelid retraction in many cases.

  6. Flow-induced elongation of von Willebrand factor precedes tension-dependent activation.

    PubMed

    Fu, Hongxia; Jiang, Yan; Yang, Darren; Scheiflinger, Friedrich; Wong, Wesley P; Springer, Timothy A

    2017-08-23

    Von Willebrand factor, an ultralarge concatemeric blood protein, must bind to platelet GPIbα during bleeding to mediate hemostasis, but not in the normal circulation to avoid thrombosis. Von Willebrand factor is proposed to be mechanically activated by flow, but the mechanism remains unclear. Using microfluidics with single-molecule imaging, we simultaneously monitored reversible Von Willebrand factor extension and binding to GPIbα under flow. We show that Von Willebrand factor is activated through a two-step conformational transition: first, elongation from compact to linear form, and subsequently, a tension-dependent local transition to a state with high affinity for GPIbα. High-affinity sites develop only in upstream regions of VWF where tension exceeds ~21 pN and depend upon electrostatic interactions. Re-compaction of Von Willebrand factor is accelerated by intramolecular interactions and increases GPIbα dissociation rate. This mechanism enables VWF to be locally activated by hydrodynamic force in hemorrhage and rapidly deactivated downstream, providing a paradigm for hierarchical mechano-regulation of receptor-ligand binding.Von Willebrand factor (VWF) is a blood protein involved in clotting and is proposed to be activated by flow, but the mechanism is unknown. Here the authors show that VWF is first converted from a compact to linear form by flow, and is subsequently activated to bind GPIbα in a tension-dependent manner.

  7. Quantitative autonomic testing.

    PubMed

    Novak, Peter

    2011-07-19

    Disorders associated with dysfunction of autonomic nervous system are quite common yet frequently unrecognized. Quantitative autonomic testing can be invaluable tool for evaluation of these disorders, both in clinic and research. There are number of autonomic tests, however, only few were validated clinically or are quantitative. Here, fully quantitative and clinically validated protocol for testing of autonomic functions is presented. As a bare minimum the clinical autonomic laboratory should have a tilt table, ECG monitor, continuous noninvasive blood pressure monitor, respiratory monitor and a mean for evaluation of sudomotor domain. The software for recording and evaluation of autonomic tests is critical for correct evaluation of data. The presented protocol evaluates 3 major autonomic domains: cardiovagal, adrenergic and sudomotor. The tests include deep breathing, Valsalva maneuver, head-up tilt, and quantitative sudomotor axon test (QSART). The severity and distribution of dysautonomia is quantitated using Composite Autonomic Severity Scores (CASS). Detailed protocol is provided highlighting essential aspects of testing with emphasis on proper data acquisition, obtaining the relevant parameters and unbiased evaluation of autonomic signals. The normative data and CASS algorithm for interpretation of results are provided as well.

  8. Quantitative myocardial perfusion SPECT.

    PubMed

    Tsui, B M; Frey, E C; LaCroix, K J; Lalush, D S; McCartney, W H; King, M A; Gullberg, G T

    1998-01-01

    In recent years, there has been much interest in the clinical application of attenuation compensation to myocardial perfusion single photon emission computed tomography (SPECT) with the promise that accurate quantitative images can be obtained to improve clinical diagnoses. The different attenuation compensation methods that are available create confusion and some misconceptions. Also, attenuation-compensated images reveal other image-degrading effects including collimator-detector blurring and scatter that are not apparent in uncompensated images. This article presents basic concepts of the major factors that degrade the quality and quantitative accuracy of myocardial perfusion SPECT images, and includes a discussion of the various image reconstruction and compensation methods and misconceptions and pitfalls in implementation. The differences between the various compensation methods and their performance are demonstrated. Particular emphasis is directed to an approach that promises to provide quantitative myocardial perfusion SPECT images by accurately compensating for the 3-dimensional (3-D) attenuation, collimator-detector response, and scatter effects. With advances in the computer hardware and optimized implementation techniques, quantitatively accurate and high-quality myocardial perfusion SPECT images can be obtained in clinically acceptable processing time. Examples from simulation, phantom, and patient studies are used to demonstrate the various aspects of the investigation. We conclude that quantitative myocardial perfusion SPECT, which holds great promise to improve clinical diagnosis, is an achievable goal in the near future.

  9. Quantitative glycomics strategies.

    PubMed

    Mechref, Yehia; Hu, Yunli; Desantos-Garcia, Janie L; Hussein, Ahmed; Tang, Haixu

    2013-04-01

    The correlations between protein glycosylation and many biological processes and diseases are increasing the demand for quantitative glycomics strategies enabling sensitive monitoring of changes in the abundance and structure of glycans. This is currently attained through multiple strategies employing several analytical techniques such as capillary electrophoresis, liquid chromatography, and mass spectrometry. The detection and quantification of glycans often involve labeling with ionic and/or hydrophobic reagents. This step is needed in order to enhance detection in spectroscopic and mass spectrometric measurements. Recently, labeling with stable isotopic reagents has also been presented as a very viable strategy enabling relative quantitation. The different strategies available for reliable and sensitive quantitative glycomics are herein described and discussed.

  10. Quantitative Hydrocarbon Surface Analysis

    NASA Technical Reports Server (NTRS)

    Douglas, Vonnie M.

    2000-01-01

    The elimination of ozone depleting substances, such as carbon tetrachloride, has resulted in the use of new analytical techniques for cleanliness verification and contamination sampling. The last remaining application at Rocketdyne which required a replacement technique was the quantitative analysis of hydrocarbons by infrared spectrometry. This application, which previously utilized carbon tetrachloride, was successfully modified using the SOC-400, a compact portable FTIR manufactured by Surface Optics Corporation. This instrument can quantitatively measure and identify hydrocarbons from solvent flush of hardware as well as directly analyze the surface of metallic components without the use of ozone depleting chemicals. Several sampling accessories are utilized to perform analysis for various applications.

  11. Quantitative photoacoustic tomography

    PubMed Central

    Yuan, Zhen; Jiang, Huabei

    2009-01-01

    In this paper, several algorithms that allow for quantitative photoacoustic reconstruction of tissue optical, acoustic and physiological properties are described in a finite-element method based framework. These quantitative reconstruction algorithms are compared, and the merits and limitations associated with these methods are discussed. In addition, a multispectral approach is presented for concurrent reconstructions of multiple parameters including deoxyhaemoglobin, oxyhaemoglobin and water concentrations as well as acoustic speed. Simulation and in vivo experiments are used to demonstrate the effectiveness of the reconstruction algorithms presented. PMID:19581254

  12. Quantitative Hydrocarbon Surface Analysis

    NASA Technical Reports Server (NTRS)

    Douglas, Vonnie M.

    2000-01-01

    The elimination of ozone depleting substances, such as carbon tetrachloride, has resulted in the use of new analytical techniques for cleanliness verification and contamination sampling. The last remaining application at Rocketdyne which required a replacement technique was the quantitative analysis of hydrocarbons by infrared spectrometry. This application, which previously utilized carbon tetrachloride, was successfully modified using the SOC-400, a compact portable FTIR manufactured by Surface Optics Corporation. This instrument can quantitatively measure and identify hydrocarbons from solvent flush of hardware as well as directly analyze the surface of metallic components without the use of ozone depleting chemicals. Several sampling accessories are utilized to perform analysis for various applications.

  13. Empathy and identification in Von Donnersmarck's The Lives of Others.

    PubMed

    Diamond, Diana

    2008-09-01

    Florian Henckel von Donnersmarck's The Lives of Others, set in the German Democratic Republic in 1984, five years before the fall of the Berlin Wall, has been called the first accurate depiction of the psychological terror wielded by the Stasi, the East German secret police, who safeguarded the dictatorship of the proletariat. The film is about the psychological and political transformation of a Stasi officer, Wiesler, who undertakes the surveillance of a prominent playwright and his actress lover. The mechanisms through which Wiesler comes to empathize and identify with the subjects of his investigation, as he observes and listens in on the rich blend of passion, poetry, and politics that characterizes their lives, are explored in depth. Wiesler's transformation is based in part on the capacity to form implicit models of the behavior and experiences of others, based on the mirror neuron system, that Gallese and his colleagues call "embodied simulation." Underpinning the processes of empathy and identification so central to this film, embodied simulation is an unconscious and prereflexive mechanism through which the actions, emotions, and sensations we observe activate internal representations of the bodily and mental states of the other. Embodied simulation also expands our understanding of the power of the primal scene, which has long been identified as a major organizer of unconscious fantasies and conflicts throughout life, and which forms the central metaphor of the film. Embodied simulation scaffolds our aesthetic response to art, music, and literature, underlies the dynamics of spectatorship, and potentially catalyzes resistance to totalitarian mass movements.

  14. Keeping von Willebrand Factor under Control: Alternatives for ADAMTS13.

    PubMed

    Tersteeg, Claudia; Fijnheer, Rob; Pasterkamp, Gerard; de Groot, Philip G; Vanhoorelbeke, Karen; de Maat, Steven; Maas, Coen

    2016-02-01

    Von Willebrand factor (VWF) is one of the most important proteins of the hemostatic system. Its multimeric state is essential for its natural function to guide platelets to sites of injury. ADAMTS13 is the key protease that regulates the multimeric state of VWF. Without ADAMTS13, VWF multimers can grow to pathologically large sizes. This is a risk factor for the life-threatening condition thrombotic thrombocytopenic purpura (TTP). In this condition, VWF-rich thrombi occlude the microvasculature of various tissues. Intriguingly, a complete ADAMTS13 deficiency does not cause continuous TTP, either in patients or genetically targeted mice. Instead, TTP occurs in episodes of disease, separated by extended periods of remission. This indicates that regulating factors beyond ADAMTS13 are likely involved in this pathologic cascade of events. This raises the question of what really happens when ADAMTS13 is (temporarily) unavailable. In this review, we explore the possible role of complementary mechanisms that are capable of modifying the thrombogenic potential of VWF.

  15. Allosteric activation of ADAMTS13 by von Willebrand factor.

    PubMed

    Muia, Joshua; Zhu, Jian; Gupta, Garima; Haberichter, Sandra L; Friedman, Kenneth D; Feys, Hendrik B; Deforche, Louis; Vanhoorelbeke, Karen; Westfield, Lisa A; Roth, Robyn; Tolia, Niraj Harish; Heuser, John E; Sadler, J Evan

    2014-12-30

    The metalloprotease ADAMTS13 cleaves von Willebrand factor (VWF) within endovascular platelet aggregates, and ADAMTS13 deficiency causes fatal microvascular thrombosis. The proximal metalloprotease (M), disintegrin-like (D), thrombospondin-1 (T), Cys-rich (C), and spacer (S) domains of ADAMTS13 recognize a cryptic site in VWF that is exposed by tensile force. Another seven T and two complement C1r/C1s, sea urchin epidermal growth factor, and bone morphogenetic protein (CUB) domains of uncertain function are C-terminal to the MDTCS domains. We find that the distal T8-CUB2 domains markedly inhibit substrate cleavage, and binding of VWF or monoclonal antibodies to distal ADAMTS13 domains relieves this autoinhibition. Small angle X-ray scattering data indicate that distal T-CUB domains interact with proximal MDTCS domains. Thus, ADAMTS13 is regulated by substrate-induced allosteric activation, which may optimize VWF cleavage under fluid shear stress in vivo. Distal domains of other ADAMTS proteases may have similar allosteric properties.

  16. On von Neumann and Bell Theorems Applied to Quantumness Tests

    NASA Astrophysics Data System (ADS)

    Alicki, Robert

    2009-04-01

    The issues, raised in Żukowski ( arXiv:0809.0115v1 , 2008), concerning the relevance of the von Neumann theorem for the single-system’s quantumness test proposed in Alicki and Van Ryn (J. Phys. A: Math. Theor. 41:062001, 2008) and performed for the case of single photon polarization in Brida et al. (Opt. Express 16:11750, 2008; arXiv:0811.3376 , 2008) and the usefulness of Bell’s inequality for testing the idea of macroscopic quantum systems are discussed in some details. Finally, the proper quantum mechanical description of the experiment with polarized photon beams is presented.

  17. Von Hippel-Lindau disease involving pancreas and biliary system

    PubMed Central

    Zhi, Xu-Ting; Bo, Qi-Yu; Zhao, Feng; Sun, Dong; Li, Tao

    2017-01-01

    Abstract Rationale: Von Hippel-Lindau (VHL) disease is a rare inherited, autosomal-dominant syndrome caused by heterozygous germline mutations in the VHL gene. VHL patients are prone to develop benign and malignant tumors and cysts in multiple organ systems involving kidneys, pancreas and central nervous system (CNS). The varied and complex clinical manifestations and radiological findings of VHL are of interest. Patient concerns: We report a 38-year-old woman with a ten-year history of VHL disease involving both pancreas and biliary system. To the best of our knowledge, direct involvement of the biliary system in VHL disease has never been reported. Diagnoses: The diagnosis was established via computed tomography scan and was confirmed by genetic testing. Interventions: The patient chose to receive conservative treatment and was followed up by magnetic resonance cholangiopancreatography and magnetic resonance imaging examination. Outcomes: Renal angiomas and cysts were found during follow-up and there were no evidence of malignant change of the pancreas and biliary system. Lessons: We described the first case of VHL-associated choledochal cysts and may present new visceral manifestations of VHL disease. Gastroenterologists should be aware of the clinical presentations of this rare disease for early detection of its life-threatening manifestations. PMID:28072736

  18. Von recklinghausen disease: one patient – various problems

    PubMed Central

    Miziołek, B; Brzezińska-Wcisło, L

    2016-01-01

    Abstract von Recklinghausen disease (vRD), more widely known as neurofibromatosis type 1, belongs to a group of genetic disorders and it is considered to be the most common genodermatosis. The disease has an autosomal dominant pattern of inheritance that involves mutations within the NF1 gene located on chromosome 17 in locus q11.2. The product of the NF1 gene is neurofibromin and the protein is well known to be a tumor suppressor factor. This counteracts possible overactivity of RAS (protein)/MAPK (mitogen-activated protein kinase) and RAS/PI3K/AKT/mTOR (phoshatydyloinositol-3-kinase/V-akt murine thy-moma viral oncogene homologue/mammalian target of rapamycin) signaling transduction pathways, preventing from uncontrolled cell proliferation and subsequent tumor formation. A loss of proper functioning of this protein leads to a development of vRD; however, a large variability in a phenotype of the disease and the onset of cutaneous findings, not necessarily in childhood, may provide a clinical diagnosis of the disease late in adulthood. We present a 52-year-old male in whom the diagnosis of vRD was proposed in the sixth decade of life, despite of multiple nodular lesions disseminated over the skin of the whole body and different neurological disturbances, not considered for a long time as manifestations of genodermatosis. PMID:27785414

  19. [Hans von Hattingberg between psychoanalysis and National Socialism].

    PubMed

    Keifenheim, Katharina Eva

    2011-01-01

    Hans von Hattingberg (1879-1944) worked as a neurologist and psychoanalyst in Munich and Berlin from about 1910 to 1944. He was a prolific writer, but met with increasing disapproval from Freud and his circle. An advocate of the union of different psychotherapeutic schools, he was initially a marginal figure in the professional field. With Hitler's rise to power his career prospered: He was offered the position of a lecturer for psychotherapy and became head of the research department at the "Göring Institute". He came to prominence with his writings on the "Neue deutsche Seelenheilkunde" despite the fact that this was never his preferred topic. The main themes of his publications were marriage, love and female emancipation. Those works contain only little of the standard Nazi ideology of the time. Not only was Hattingberg never a member of the NSDAP (the ruling party), but in some respects he could conceivably be considered a member of the resistance. The article outlines the most important stages of Hattingberg's life and focuses on the question of how he positioned himself after 1933, when it became vital for him to reconcile psychoanalysis and National Socialism.

  20. [Carl Friedrich von Weizsäcker - physicist and philosopher].

    PubMed

    Drieschner, Michael

    2014-01-01

    The subject of this paper is the philosopher Carl Friedrich von weizsäcker, especially under the aspect of the relation between physics and philosophy in his works. The decisive role of time in physics as well as in philosophy is described, and thereof is derived the comprehension of probability as a predicted relative frequency. Consequently quantum mechanics is interpreted as a theory of probability that uses "quantum logic" instead of classical propositional logic that is used in "normal" probability. The philosophical fruit of that is the interpretation of potentiality as the modality of the future. Weizsäcker's proposals for a justification of physics a priori are dealt with as well as his approach to a theory of "ur-objects", which are atoms in the strictest sense: q-bits.--Questions of Weizsäcker's personality are addressed: His role in the development of the nuclear reactor and atomic bomb in Nazi time, his enthusiasm and his religiousness as well as his efforts towards world peace.

  1. Molecular and cellular biology of von Willebrand factor.

    PubMed

    Denis, Cécile V

    2002-01-01

    von Willebrand factor (VWF) is a plasma protein that performs 2 main functions in hemostasis: it mediates platelet adhesion to the injured vessel wall, and it carries and protects coagulation factor VIII. VWF is synthesized through a multistep process in endothelial cells and megakaryocytes as a very large polymer composed of identical disulfide-linked 250-kd subunits. In endothelial cells, VWF not only directs the formation of its own storage granules, the Weibel-Palade bodies, but it also acts as a chaperone molecule to direct other proteins, such as P-selectin, into these granules. Upon stimulation of the endothelium, the Weibel-Palade bodies will be translocated to the plasma membrane, and their contents will be secreted into the plasma milieu. The expression of VWF can be regulated at different levels by a number of genetic and environmental factors, resulting in control of its activity. New roles for VWF, especially in inflammatory processes, have recently been suggested, indicating that some aspects of this well-studied protein remain to be investigated.

  2. Characterization of the mouse von Willebrand factor promoter.

    PubMed

    Guan, J; Guillot, P V; Aird, W C

    1999-11-15

    Expression of the von Willebrand factor (vWF) gene is restricted to the endothelial and megakaryocyte lineages. Within the endothelium, expression of vWF varies between different vascular beds. We have previously shown that the human vWF promoter spanning a region between -2182 (relative to the start site of transcription) and the end of the first intron contains information for environmentally responsive, vascular bed-specific expression in the heart, skeletal muscle, and brain. In the present study, we cloned the mouse vWF (mvWF) promoter and studied its function in cultured endothelial cells and transgenic mice. In transient transfection assays, the mvWF gene was found to be regulated by distinct mechanisms in different endothelial cell subtypes. In independent lines of transgenic mice, an mvWF promoter fragment containing DNA sequences between -2645 and the end of the first intron directed endothelial cell-specific expression in the microvascular beds of the heart, brain, and skeletal muscle as well as the endothelial lining of the aorta. In 1 line of mice, reporter gene activity was also detected in bone marrow megakaryocytes. Taken together, these findings suggest that both the mouse and human vWF promoters are regulated by vascular bed-specific mechanisms.

  3. Functional property of von Willebrand factor under flowing blood.

    PubMed

    Sugimoto, Mitsuhiko; Miyata, Shigeki

    2002-01-01

    von Willebrand factor (vWF) is produced in megakaryocytes and endothelial cells, is stored in the alpha-granule of platelets and in the Weibel-Palade body of endothelial cells, and is present in plasma and vascular subendothelium. This huge protein with a unique multimeric structure plays a pivotal role in both hemostasis and pathological intravascular thrombosis, in which vWF contributes to both platelet adhesion/aggregation and blood coagulation through its multiple adhesive functions for the platelet membrane receptors, glycoprotein Ib-IX-V complex, integrin alphaIIbbeta3, heparin, various types of collagen, and coagulation factor VIII. Among various functions, the most characteristic feature of vWF is its determinant role on platelet thrombus formation under high-shear-rate conditions. Indeed, at in vivo rheological situations where platelets are flowing with high speed in the bloodstream, the only reaction that can initiate mural thrombogenesis is the interaction of vWF with platelet glycoprotein Ibalpha. The recent x-ray analysis of the crystal structure of various functional domains and functional studies of this protein under experimental flow conditions have rapidly advanced and revised our knowledge of the structure-function relationships of vWF, a key protein for hemostasis and arterial thrombosis.

  4. Darwin the geologist: Between Lyell and von Buch.

    PubMed

    Gohau, Gabriel

    2010-02-01

    Upon returning from his voyage on the Beagle, Darwin prepared reports of his geological observations. Together, these reveal Darwin's approach to reasoning about geology. Darwin argued that successive terraces prove a very gradual elevation of the coast that lagoon islands show a reciprocal sinking of the oceanic floor. Hence, Darwin reinforced Lyell's uniformitarian, or steady state theory. Unlike lagoon islands, the movement of erratic boulders onto the plains is evidence of forces, which do not now exist. Darwin and Lyell attributed this movement to floating icebergs. However, mountain formation remained difficult for them to explain with reference to contemporary causes. Lyell discovered uplifts in Scandinavia, which resulted from epirogenesis, whereas mountain formation is an orogenesis, which involves both folding and uplift. Darwin was more impressed by uplift than by folds. However, when in Cordillera he saw strata overturned by masses of injected rock, proving successive periods of violence, Darwin took a position, which was closer to the plutonic theories of von Buch and Humboldt than it was to Lyell's uniformitarian views.

  5. [Hermann von Helmholtz and Carl Stumpf on consonance and dissonance].

    PubMed

    Kursell, Julia

    2008-06-01

    The article juxtaposes Hermann von Helmholtz's work in the experimental physiology of hearing and Carl Stumpf's tone psychology, focusing on the problem of consonance and dissonance in music. It argues that the experimental set-up plays a major role in the approaches to hearing of both Helmholtz and Stumpf, shaping their redefinition of the musical concepts of consonance and dissonance. Helmholtz, however, explains dissonance as resulting from the beats that are heard when sound waves interfere, while Stumpf explains consonance from the fusion (Verschmelzung) of sounds, noting that two tones, depending on their distance cannot always be recognized as two but are heard as one single tone. Helmholtz's definition of dissonance eventually threatens his own theory of hearing, which is based on the mechanical principle of resonance and considers sound to be composed of sinusoidal waves. Both the physical and the mathematical tools he uses cannot easily be brought into accordance with his experimental findings on beats, which ask for a discrimination of fast changes in intensity. Dissonance thus becomes "unrecomendable" for Helmholtz, because it overstrains the ear. Stumpf's research, in contrast, has its point of departure in the historically given set of intervals and tries to find a principle that would explain this choice. His tests with experimental subjects who have no conscious knowledge of musical harmony and prove incapable to follow or reproduce music reveals to him a difference between the unity and multiplicity of tones.

  6. von Economo neurones are selectively targeted in frontotemporal dementia.

    PubMed

    Santillo, A F; Nilsson, C; Englund, E

    2013-08-01

    von Economo neurones (VEN) are bipolar neurones located in the anterior cingulate cortex (ACC) and the frontoinsular cortex (FI), areas affected early in behavioural variant frontotemporal dementia (bvFTD), in which VEN may constitute a selectively vulnerable cellular population. A previous study has shown a selective loss of VEN in FTD above other neurones in the ACC of FTD. The aim of this study was to confirm this finding in a larger cohort, using a different methodology, and to examine VEN loss in relation to neuropathological severity and molecular pathology. VEN and neighbouring neurones (NN) were quantified in layers Va and Vb of the right dorsal ACC in 21 cases of bvFTD, 10 cases of Alzheimer's disease (AD) and 10 non-demented controls (NDC). A marked VEN reduction was seen in all FTD cases. In the neuropathologically early cases of FTD (n = 13), VEN/10,000 NN was significantly reduced by 53% compared with NDC (P < 0.001) and 41% compared with AD (P = 0.019), whereas AD patients showed a non-significant 30% reduction of VEN/10,000 NN compared with NDC. VEN reduction was present in all protein pathology subgroups. In conclusion, this study confirms selective sensitivity of VEN in FTD and suggests that VEN loss is an early event in the neurodegenerative process. © 2013 British Neuropathological Society.

  7. Bifurcation analysis of an infinite array of von Karman Streets

    NASA Astrophysics Data System (ADS)

    Ghaemi Oskouei, Babak; Kanso, Eva; Newton, Paul K.

    2008-11-01

    This research investigates the behavior of an infinite array of (inverse) von Karman streets. Primary motivation is to model the wake dynamics in large fish schools. Ignoring the fish we focus on the dynamic interaction of multiple wakes. In particular, we investigate the problem of fluid transport between adjacent vortex streets for its relevance to understanding the transport of oxygen and nutrients to inner fish in large schools as well as understanding flow barriers to passive locomotion. We prove that the configuration of vortices is in relative equilibrium, meaning that the streamline pattern remains steady in the frame moving with vortices. We look at the topology of these streamline patterns plotted in the moving frame which lends insight to fluid transport through the mid-wake region. Fluid is advected along different paths depending on the distance separating two adjacent streets. When the streets are far apart, the dynamics is decoupled and fluid is transported globally between two adjacent streets. When the streets get closer to each other, the number of streets that enter into partnership in transporting fluid among themselves increases. This observation motivates a bifurcation analysis which links the distance between streets to the maximum number of streets transporting fluid among themselves.

  8. Ludwig von Bertalanffy's Organismic View on the Theory of Evolution

    PubMed Central

    Drack, Manfred

    2015-01-01

    Ludwig von Bertalanffy was a key figure in the advancement of theoretical biology. His early considerations already led him to recognize the necessity of considering the organism as a system, as an organization of parts and processes. He termed the resulting research program organismic biology, which he extended to all basic questions of biology and almost all areas of biology, hence also to the theory of evolution. This article begins by outlining the rather unknown (because often written in German) research of Bertalanffy in the field of theoretical biology. The basics of the organismic approach are then described. This is followed by Bertalanffy's considerations on the theory of evolution, in which he used methods from theoretical biology and then introduced his own, organismic, view on evolution, leading to the demand for finding laws of evolution. Finally, his view on the concept of homology is presented. J. Exp. Zool. (Mol. Dev. Evol.) 324B: 77–90, 2015. © 2015 The Authors. Journal of Experimental Zoology Part B: Molecular and Developmental Evolution published by Wiley Periodicals, Inc. PMID:25727202

  9. Modellbasierte Segmentierung von differenzierten Lymphknoten in CT-Daten

    NASA Astrophysics Data System (ADS)

    Dornheim, Lars; Dornheim, Jana

    Für die computerbasierte Diagnoseunterstützung bei Tumorerkrankungen ist Wissen über Lage, Ausdehnung und Art der Lymphknoten für die TNM-Klassifikation nötig. Für die computergestütze Planung nachfolgender Eingriffe wie der Hals-Lymphknoten-Ausräumung, ist dieses Wissen ebenfalls von Bedeutung. Deshalb ist ein effizientes und exaktes Segmentierungsverfahren für Lymphknoten in CT-Datensätzen erforderlich, das besonders auch mit pathologisch veränderten Lymphknoten zurechtkommt. Basierend auf früheren Arbeiten präsentieren wir in dieser Arbeit ein deutlich weiterentwickeltes, modellbasiertes Segmentierungsverfahren für Lymphknoten in CT-Datensätzen, mit dem nun besonders auch vergrößerte sowie nekrotische Lymphknoten adressiert werden. Unser Verfahren wurde an 21 Lymphknoten aus 5 CT-Datensätzen getestet, darunter mehrere vergrößerte und nekrotische. Die Ergebnisse liegen im Bereich der Inter-Personen-Varianz und verbessern die Ergebnisse früherer Arbeiten noch einmal spürbar.

  10. Memory recall in arousing situations - an emotional von Restorff effect?

    PubMed

    Wiswede, Daniel; Rüsseler, Jascha; Hasselbach, Simone; Münte, Thomas F

    2006-07-24

    Previous research has demonstrated a relationship between memory recall and P300 amplitude in list learning tasks, but the variables mediating this P300-recall relationship are not well understood. In the present study, subjects were required to recall items from lists consisting of 12 words, which were presented in front of pictures taken from the IAPS collection. One word per list is made distinct either by font color or by a highly arousing background IAPS picture. This isolation procedure was first used by von Restorff. Brain potentials were recorded during list presentation. Recall performance was enhanced for color but not for emotional isolates. Event-related brain potentials (ERP) showed a more positive P300-component for recalled non-isolated words and color-isolated words, compared to the respective non-remembered words, but not for words isolated by arousing background. Our findings indicate that it is crucial to take emotional mediator variables into account, when using the P300 to predict later recall. Highly arousing environments might force the cognitive system to interrupt rehearsal processes in working memory, which might benefit transfer into other, more stable memory systems. The impact of attention-capturing properties of arousing background stimuli is also discussed.

  11. THE FINE STRUCTURE OF VON EBNER'S GLAND OF THE RAT

    PubMed Central

    Hand, Arthur R.

    1970-01-01

    The fine structure of von Ebner's gland was studied in untreated rats and rats stimulated to secrete by fasting-refeeding or injection of pilocarpine. Cytological features were similar to those reported for pancreas and parotid gland. Abundant granular endoplasmic reticulum filled the basal portion of the cell, a well-developed Golgi complex was located in the vicinity of the nucleus, and the apical portion of the cell was filled with dense secretory granules. Dense heterogeneous bodies resembling lysosomes were closely associated with the Golgi complex. Coated vesicles were seen in the Golgi region and also in continuity with the cell membrane. Granule discharge occurred by fusion of the granule membrane with the cell membrane at the secretory surface. Successive fusion of adjacent granules to the previously fused granule formed a connected string of granules in the apical cytoplasm. Myoepithelial cells were present within the basement membrane, and nerve processes were seen adjacent to acinar and myoepithelial cells. Duct cells resembled the intercalated duct cells of the major salivary glands. PMID:5411078

  12. Emperor Ashoka: Did he suffer from von Recklinghausen's diseases?

    PubMed Central

    Wig, N. N.; Sharma, Sheetal

    2015-01-01

    Emperor Ashoka is widely regarded as one of the greatest rulers of India. This paper mainly deals with his medical condition as recorded in the Buddhist texts of Sri Lanka as well as in the Buddhist texts of North India and Nepal. These sources mention his skin disorder which is described as very rough and unpleasant to touch. He is also known to have episodes of loss of consciousness at various times in his life. One of the earliest representations of Ashoka, about 100 years after his death at one of the gates of Sanchi Stupa, shows Ashoka fainting when visiting the Bodhi tree and being held by his queens. In this sculpture, Emperor Ashoka is shown as a man of short height, large head and a paunchy abdomen. In this paper, it is speculated that Emperor Ashoka was probably suffering from von Recklinghausen disease (Neurofibromatosis Type 1), which could explain his skin condition, episodes of loss of consciousness (probably epilepsy) and other bodily deformities. PMID:25657467

  13. Multiple von Neumann computers: an evolutionary approach to functional emergence.

    PubMed

    Suzuki, H

    1997-01-01

    A novel system composed of multiple von Neumann computers and an appropriate problem environment is proposed and simulated. Each computer has a memory to store the machine instruction program, and when a program is executed, a series of machine codes in the memory is sequentially decoded, leading to register operations in the central processing unit (CPU). By means of these operations, the computer not only can handle its generally used registers but also can read and write the environmental database. Simulation is driven by genetic algorithms (GAs) performed on the population of program memories. Mutation and crossover create program diversity in the memory, and selection facilitates the reproduction of appropriate programs. Through these evolutionary operations, advantageous combinations of machine codes are created and fixed in the population one by one, and the higher function, which enables the computer to calculate an appropriate number from the environment, finally emerges in the program memory. In the latter half of the article, the performance of GAs on this system is studied. Under different sets of parameters, the evolutionary speed, which is determined by the time until the domination of the final program, is examined and the conditions for faster evolution are clarified. At an intermediate mutation rate and at an intermediate population size, crossover helps create novel advantageous sets of machine codes and evidently accelerates optimization by GAs.

  14. [Recollections of Carl Friedrich von Weizsäcker].

    PubMed

    Gottstein, Klaus

    2014-01-01

    Reminiscences and a diary of the author allow a report on meetings, conversations, experiences and joint undertakings with Carl Friedrich von Weizsäcker during five decades. They began in the winter of 1948/49 in Göttingen in the Max Planck Institute for Physics where Werner Heisenberg was the director and Weizsäcker head of the Theory Division and where the author was graduate and post-graduate student and later group and division leader. In the 1960s a close cooperation with Weizsäcker resulted from common membership in Working Committee and Board of the Federation of German Scientists (VDW). As Science Attaché at the Embassy in Washington from 1971 to 1974 the author prepared for Weizsäcker the programme of his visits to the U.S. From 1974 to 1977 he cooperated closely with Weizsäcker, preparing the sessions of the Advisory Committee to the Federal Minister of Research and Technology of which Weizsäcker was Chair. Also in later years there were illuminating discussions and correspondences.

  15. [Heinrich von Kleist--crisis and creative overcoming].

    PubMed

    Schlimme, J

    2001-07-01

    Heinrich von Kleist's life was shaken repeatedly by negative life-events, finally he committed suicide in his last life-crisis (1811). His work was mostly understood as descriptions of negative life-events and failed-being. In this article it will be shown that in at least two "crises" Kleist's work can be understood as a creative overcome of those. Kleist shows in his "Essay to Find a Sure Way to Happiness" (1799) his way of solving his "Soldier-Crisis" (1798), a depressive episode. In "The Broken Jug" (1802 - 1805) he shows the implications of a philosophical problem experienced in his "Kant-Crisis" (1801) and offers chances to overcome this particular crisis, which still seems to be an actual problem of ourselves. Though his crises must be understood as depressive episodes, at least the "Kant-Crisis" with its connections to philosophical and artistical matters seems to be more complicated than a simple depressive syndrome. Kleist formulates his basic life-experience, to be repeatedly shaken by "crises" respectively depressive episodes and the necessity to overcome each in a new way of living.

  16. A Laboratory Phenotype/Genotype Correlation of 1167 French Patients From 670 Families With von Willebrand Disease

    PubMed Central

    Veyradier, Agnès; Boisseau, Pierre; Fressinaud, Edith; Caron, Claudine; Ternisien, Catherine; Giraud, Mathilde; Zawadzki, Christophe; Trossaert, Marc; Itzhar-Baïkian, Nathalie; Dreyfus, Marie; d’Oiron, Roseline; Borel-Derlon, Annie; Susen, Sophie; Bezieau, Stéphane; Denis, Cécile V.; Goudemand, Jenny

    2016-01-01

    Abstract von Willebrand disease (VWD) is a genetic bleeding disease due to a defect of von Willebrand factor (VWF), a glycoprotein crucial for platelet adhesion to the subendothelium after vascular injury. VWD include quantitative defects of VWF, either partial (type 1 with VWF levels <50 IU/dL) or virtually total (type 3 with undetectable VWF levels) and also qualitative defects of VWF (type 2 variants with discrepant antigenic and functional VWF levels). The most bleeding forms of VWD usually do not concern type 1 patients with the mildest VWF defects (VWF levels between 30 and 50 IU/dL). The French reference center for VWD performed a laboratory phenotypic and genotypic analysis in 1167 VWD patients (670 families) selected by their basic biologic phenotype: type 3, type 2, and type 1 with VWF levels <30 IU/dL. In these patients indeed, to achieve an accurate diagnosis of VWD type and subtype is crucial for the management (treatment and genetic counseling). A phenotype/genotype correlation was present in 99.3% of cases; 323 distinct VWF sequence variations (58% of novel) were identified (missense 67% versus truncating 33%). The distribution of VWD types was: 25% of type 1, 8% of type 3, 66% of type 2 (2A: 18%, 2B: 17%, 2M: 19%, 2N: 12%), and 1% of undetermined type. Type 1 VWD was related either to a defective synthesis/secretion or to an accelerated clearance of VWF. In type 3 VWD, bi-allelic mutations of VWF were found in almost all patients. In type 2A, the most frequent mechanism was a hyper-proteolysis of VWF. Type 2B showed 85% of patients with deleterious mutations (distinct from type 2B New York). Type 2M was linked to a defective binding of VWF to platelet glycoprotein Ib or to collagen. Type 2N VWD included almost half type 2N/3. This biologic study emphasizes the complex mechanisms for both quantitative and qualitative VWF defects in VWD. In addition, this study provides a new epidemiologic picture of the most bleeding forms of VWD in which

  17. Enzymes that hydrolyze adenine nucleotides in platelets and polymorphisms in the alpha2 gene of integrin alpha2beta1 in patients with von Willebrand disease.

    PubMed

    Santos, Karen Freitas; Battisti, Vanessa; Corrêa, Maísa de Carvalho; Mann, Thaís Rapachi; Pereira, Renata da Silva; Araújo, Maria do Carmo; Brülê, Alice Odete; Schetinger, Maria Rosa Chitolina; Morsch, Vera Maria

    2010-07-01

    Von Willebrand disease (VWD) is one of the most common inherited bleeding diseases caused by a qualitative or quantitative deficiency of the von Willebrand factor (FvW). FvW is a multimeric glycoprotein synthesized by megakaryocytes and endothelial cells and it is present in the subendothelial matrix, blood plasma, platelets, and endothelium. This glycoprotein plays an important role in thrombus formation by initiating platelet adhesion to sites of injury as well as platelet aggregation. The aim of this study was to evaluate the activities of enzymes that hydrolyze adenine nucleotides in platelets, ristocetin-induced platelet aggregation (RIPA), and polymorphisms of the alpha2 gene of alpha2beta1 integrin from VWD patients. Platelet nucleoside triphosphate diphosphohydrolase (NTPDase), 5'-nucleotidase, and ecto-nucleotide pyrophosphatase/phosphodiesterase (E-NPP) activities were verified in 14 VWD patients. For RIPA determination, a final concentration of 1.25 mg/ml of ristocetin was used. Polymorphisms of the alpha2 gene were analyzed through PCR. Platelet NTPDase and E-NPP were decreased in VWD patients. 5'-Nucleotidase activity was not statistically significant between controls and VWD patients. RIPA was significantly reduced, with an allelic frequency of 78.57% for 807C in VWD patients. Our results indicated reduced platelet NTPDase and E-NPP activities which might be related to the low platelet adhesiveness. The prevalence of the 807C allele might account for the variability in bleeding in VWD.

  18. Quantitative Decision Support Requires Quantitative User Guidance

    NASA Astrophysics Data System (ADS)

    Smith, L. A.

    2009-12-01

    Is it conceivable that models run on 2007 computer hardware could provide robust and credible probabilistic information for decision support and user guidance at the ZIP code level for sub-daily meteorological events in 2060? In 2090? Retrospectively, how informative would output from today’s models have proven in 2003? or the 1930’s? Consultancies in the United Kingdom, including the Met Office, are offering services to “future-proof” their customers from climate change. How is a US or European based user or policy maker to determine the extent to which exciting new Bayesian methods are relevant here? or when a commercial supplier is vastly overselling the insights of today’s climate science? How are policy makers and academic economists to make the closely related decisions facing them? How can we communicate deep uncertainty in the future at small length-scales without undermining the firm foundation established by climate science regarding global trends? Three distinct aspects of the communication of the uses of climate model output targeting users and policy makers, as well as other specialist adaptation scientists, are discussed. First, a brief scientific evaluation of the length and time scales at which climate model output is likely to become uninformative is provided, including a note on the applicability the latest Bayesian methodology to current state-of-the-art general circulation models output. Second, a critical evaluation of the language often employed in communication of climate model output, a language which accurately states that models are “better”, have “improved” and now “include” and “simulate” relevant meteorological processed, without clearly identifying where the current information is thought to be uninformative and misleads, both for the current climate and as a function of the state of the (each) climate simulation. And thirdly, a general approach for evaluating the relevance of quantitative climate model output

  19. Quantitative Simulation Games

    NASA Astrophysics Data System (ADS)

    Černý, Pavol; Henzinger, Thomas A.; Radhakrishna, Arjun

    While a boolean notion of correctness is given by a preorder on systems and properties, a quantitative notion of correctness is defined by a distance function on systems and properties, where the distance between a system and a property provides a measure of "fit" or "desirability." In this article, we explore several ways how the simulation preorder can be generalized to a distance function. This is done by equipping the classical simulation game between a system and a property with quantitative objectives. In particular, for systems that satisfy a property, a quantitative simulation game can measure the "robustness" of the satisfaction, that is, how much the system can deviate from its nominal behavior while still satisfying the property. For systems that violate a property, a quantitative simulation game can measure the "seriousness" of the violation, that is, how much the property has to be modified so that it is satisfied by the system. These distances can be computed in polynomial time, since the computation reduces to the value problem in limit average games with constant weights. Finally, we demonstrate how the robustness distance can be used to measure how many transmission errors are tolerated by error correcting codes.

  20. Quantitative Decision Making.

    ERIC Educational Resources Information Center

    Baldwin, Grover H.

    The use of quantitative decision making tools provides the decision maker with a range of alternatives among which to decide, permits acceptance and use of the optimal solution, and decreases risk. Training line administrators in the use of these tools can help school business officials obtain reliable information upon which to base district…

  1. Critical Quantitative Inquiry in Context

    ERIC Educational Resources Information Center

    Stage, Frances K.; Wells, Ryan S.

    2014-01-01

    This chapter briefly traces the development of the concept of critical quantitative inquiry, provides an expanded conceptualization of the tasks of critical quantitative research, offers theoretical explanation and justification for critical research using quantitative methods, and previews the work of quantitative criticalists presented in this…

  2. Critical Quantitative Inquiry in Context

    ERIC Educational Resources Information Center

    Stage, Frances K.; Wells, Ryan S.

    2014-01-01

    This chapter briefly traces the development of the concept of critical quantitative inquiry, provides an expanded conceptualization of the tasks of critical quantitative research, offers theoretical explanation and justification for critical research using quantitative methods, and previews the work of quantitative criticalists presented in this…

  3. Neurocognitive profile of a young adolescent with DK phocomelia/von Voss phocomelia/von Voss Cherstvoy syndrome.

    PubMed

    Antonini, Tanya N; Van Horn Kerne, Valerie; Axelrad, Marni E; Karaviti, Lefkothea P; Schwartz, David D

    2015-07-01

    DK phocomelia/von Voss Cherstvoy syndrome is a rare condition characterized by upper limb and urogenital abnormalities and various brain anomalies. Previously reported cases have noted significant developmental delays, although no formal testing of cognitive abilities has been reported. In this paper we describe results from a comprehensive neuropsychological evaluation of a 12-year-old male with DK phocomelia syndrome. Test findings indicated mild impairment in intellectual functioning, with more significant impairment in adaptive skills and academic achievement. The neuropsychological profile converged with neurological findings, showing a distinct pattern of strengths and weaknesses that suggests functional compromise of posterior brain regions with relatively well-preserved functioning of more anterior regions. Specifically, impairments were evident in perceptual reasoning, visual perception, and visuomotor integration, whereas normal or near normal functioning was evident in memory, receptive language, social cognition, attention, and most aspects of executive functioning. To our knowledge this is the first report to describe the neurocognitive profile of an individual with DK phocomelia syndrome. © 2015 Wiley Periodicals, Inc.

  4. Epidemiologic interactions, complexity, and the lonesome death of Max von Pettenkofer.

    PubMed

    Morabia, Alfredo

    2007-12-01

    In the mid-19th century, the German hygienist Max von Pettenkofer viewed cholera as resulting from the interaction between a postulated cholera germ and the characteristics of soils. In order to cause cholera, the cholera germ had to become a cholera miasma, but this transformation required prolonged contact of the germ with dry and porous soils when groundwater levels were low. This hypothetical germ-environment interaction explained more observations than did contagion alone. Despite its attraction, von Pettenkofer's postulate also implied that cholera-patient quarantine or water filtration was useless to prevent and/or control cholera epidemics. The disastrous consequences of the lack of water filtration during the massive outbreak of cholera in the German town of Hamburg in 1892 tarnished von Pettenkofer's reputation and marked thereafter the course of his life. von Pettenkofer's complex mode of thinking sank into oblivion even though, in hindsight, germ-environment interactions are more appropriate than is bacteriology alone for explaining the occurrence of cholera epidemics in populations. Revisiting the fate of von Pettenkofer's theory with modern lenses can benefit today's quest for deciphering the causes of complex associations.

  5. Test of Von Baer's law of the conservation of early development.

    PubMed

    Poe, Steven

    2006-11-01

    One of the oldest and most pervasive ideas in comparative embryology is the perceived evolutionary conservation of early ontogeny relative to late ontogeny. Karl Von Baer first noted the similarity of early ontogeny across taxa, and Ernst Haeckel and Charles Darwin gave evolutionary interpretation to this phenomenon. In spite of a resurgence of interest in comparative embryology and the development of mechanistic explanations for Von Baer's law, the pattern itself has been largely untested. Here, I use statistical phylogenetic approaches to show that Von Baer's law is an unnecessarily complex explanation of the patterns of ontogenetic timing in several clades of vertebrates. Von Baer's law suggests a positive correlation between ontogenetic time and amount of evolutionary change. I compare ranked position in ontogeny to frequency of evolutionary change in rank for developmental events and find that these measures are not correlated, thus failing to support Von Baer's model. An alternative model that postulates that small changes in ontogenetic rank are evolutionarily easier than large changes is tentatively supported.

  6. Von Bertalanffy's dynamics under a polynomial correction: Allee effect and big bang bifurcation

    NASA Astrophysics Data System (ADS)

    Leonel Rocha, J.; Taha, A. K.; Fournier-Prunaret, D.

    2016-02-01

    In this work we consider new one-dimensional populational discrete dynamical systems in which the growth of the population is described by a family of von Bertalanffy's functions, as a dynamical approach to von Bertalanffy's growth equation. The purpose of introducing Allee effect in those models is satisfied under a correction factor of polynomial type. We study classes of von Bertalanffy's functions with different types of Allee effect: strong and weak Allee's functions. Dependent on the variation of four parameters, von Bertalanffy's functions also includes another class of important functions: functions with no Allee effect. The complex bifurcation structures of these von Bertalanffy's functions is investigated in detail. We verified that this family of functions has particular bifurcation structures: the big bang bifurcation of the so-called “box-within-a-box” type. The big bang bifurcation is associated to the asymptotic weight or carrying capacity. This work is a contribution to the study of the big bang bifurcation analysis for continuous maps and their relationship with explosion birth and extinction phenomena.

  7. von Baer's law for the ages: lost and found principles of developmental evolution.

    PubMed

    Abzhanov, Arhat

    2013-12-01

    In 1828, Karl Ernst von Baer formulated a series of empirically defined rules, which became widely known as the 'Law of Development' or 'von Baer's law of embryology'. This was one the most significant attempts to define the principles that connected morphological complexity and embryonic development. Understanding this relation is central to both evolutionary biology and developmental genetics. Von Baer's ideas have been both a source of inspiration to generations of biologists and a target of continuous criticism over many years. With advances in multiple fields, including paleontology, cladistics, phylogenetics, genomics, and cell and developmental biology, it is now possible to examine carefully the significance of von Baer's law and its predictions. In this review, I argue that, 185 years after von Baer's law was first formulated, its main concepts after proper refurbishing remain surprisingly relevant in revealing the fundamentals of the evolution-development connection, and suggest that their explanation should become the focus of renewed research. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Evaluation of von Willebrand factor in COPD patients*

    PubMed Central

    Bártholo, Thiago Prudente; da Costa, Cláudia Henrique; Rufino, Rogério

    2014-01-01

    OBJECTIVE: To compare the absolute serum von Willebrand factor (vWF) levels and relative serum vWF activity in patients with clinically stable COPD, smokers without airway obstruction, and healthy never-smokers. METHODS: The study included 57 subjects, in three groups: COPD (n = 36); smoker (n = 12); and control (n = 9). During the selection phase, all participants underwent chest X-rays, spirometry, and blood testing. Absolute serum vWF levels and relative serum vWF activity were obtained by turbidimetry and ELISA, respectively. The modified Medical Research Council scale (cut-off score = 2) was used in order to classify COPD patients as symptomatic or mildly symptomatic/asymptomatic. RESULTS: Absolute vWF levels were significantly lower in the control group than in the smoker and COPD groups: 989 ± 436 pg/mL vs. 2,220 ± 746 pg/mL (p < 0.001) and 1,865 ± 592 pg/mL (p < 0.01). Relative serum vWF activity was significantly higher in the COPD group than in the smoker group (136.7 ± 46.0% vs. 92.8 ± 34.0%; p < 0.05), as well as being significantly higher in the symptomatic COPD subgroup than in the mildly symptomatic/asymptomatic COPD subgroup (154 ± 48% vs. 119 ± 8%; p < 0.05). In all three groups, there was a negative correlation between FEV1 (% of predicted) and relative serum vWF activity (r2 = −0.13; p = 0.009). CONCLUSIONS: Our results suggest that increases in vWF levels and activity contribute to the persistence of systemic inflammation, as well as increasing cardiovascular risk, in COPD patients. PMID:25210959

  9. Posttonsillectomy hemorrhage in children with von Willebrand disease or hemophilia.

    PubMed

    Sun, Gordon H; Auger, Katherine A; Aliu, Oluseyi; Patrick, Stephen W; DeMonner, Sonya; Davis, Matthew M

    2013-03-01

    It is uncertain whether children with bleeding disorders are at higher risk of posttonsillectomy hemorrhage compared with the general pediatric population. To estimate the national rate of posttonsillectomy hemorrhage in children previously diagnosed with von Willebrand disease (VWD) or hemophilia, and to analyze potential risk factors for postoperative bleeding in these children. A cross-sectional analysis of the Healthcare Cost and Utilization Project Kids' Inpatient Database (KID) from the Agency for Healthcare Research and Quality for 2000, 2003, 2006, and 2009. Academic and community-based nonrehabilitation hospitals from 44 states participating in the KID project. An estimated 508 children with either VWD or hemophilia. Tonsillectomy with and without adenoidectomy, and subsequent hospitalization. Treatment for posttonsillectomy hemorrhage. We extracted all cases of tonsillectomy, adenotonsillectomy, and posttonsillectomy hemorrhage in patients with VWD or hemophilia using International Classification of Diseases, Ninth Revision diagnostic and procedure codes and applied national weights to estimate rates of posttonsillectomy hemorrhage. Using data regarding patient demographic characteristics, surgical indication, blood transfusion, hospital length of stay, and mortality, we conducted bivariate analyses to identify associations between possible risk factors and posttonsillectomy hemorrhage. Mean age was 7 years, and most patients were male, white, urbanites who had private insurance and underwent tonsillectomy for airway obstruction. The hemorrhage rate within 1 day of tonsillectomy (immediate) was 1.6% while the hemorrhage rate at least 2 days after tonsillectomy (delayed) was estimated at 15%. Delayed hemorrhage was associated with older age (P < .001) and was as high as 35% in children at least 16 years old. The rate of blood transfusion was 2.4%. There were no fatalities. The frequency of immediate posttonsillectomy hemorrhage in children with VWD or

  10. Effect of von Willebrand factor on clot structure and lysis.

    PubMed

    Marchi, Rita; Rojas, Héctor

    2015-07-01

    Von Willebrand Factor (vWF) is constitutively secreted by the endothelium and incorporated in the fibrin clots under slow clotting conditions. The aim of the present work was to study the effect of vWF on clot structure and lysis. Purified fibrinogen was mixed with vWF or Tris-buffered saline and clotted with thrombin - activated factor XIII. Fibrin polymerization was followed by turbidity at 350 nm during 2.5 h. After this time, plasmin was added on the top of the clots, and the optical density (OD) was read until baseline values. vWF effect on network[Combining Acute Accent]s porosity was evaluated by permeation using the same clotting conditions as for fibrin polymerization. Clot structure was visualized and analyzed by laser scanning confocal microscopy (LSCM). The rate of fibrin polymerization was 1.47 mOD/s in the presence of vWF and 0.5 mOD/s when vWF was not added (P < 0.05). The fibrin lysis rate was approximately four times faster when vWF was added to fibrinogen. The fibrin network porosity was (20.4 ± 1.6) × 10 cm with vWF and (8.3 ± 1.2) × 10 cm without external vWF (P < 0.05). The analysis of LSCM images showed that vWF increased fibrin fibers diameter and the networks[Combining Acute Accent] pores size. In conclusion, vWF covalently crosslinked to fibrin modify its structure (increases fibrin diameter and the pores filling space of the meshwork) that accelerates the fibrin lysis rate.

  11. von Willebrand factor storage requires intact prosequence cleavage site.

    PubMed

    Journet, A M; Saffaripour, S; Cramer, E M; Tenza, D; Wagner, D D

    1993-02-01

    Large multimers of the adhesive glycoprotein von Willebrand factor (vWf) are stored in endothelial cells in rod-shaped granules called Weibel-Palade bodies, while small multimers are secreted constitutively. Expression of pro-vWf in other cells with a regulated pathway of secretion, results in formation of vWf-containing storage granules that have a morphology similar to Weibel-Palade bodies. vWf expressed without its prosequence is not stored. To evaluate the importance of prosequence cleavage in vWf storage, the Arg at position -1, known to be necessary for cleavage, was mutated to Gly. Transfection of this cleavage mutant into two cell lines with a regulated pathway of secretion (RIN 5F and AtT-20 cells) led to the formation of large multimers. However, treatment of the cell lysates by the enzyme endoglycosidase H (Endo-H) did not reveal significant amounts of intracellular Endo-H-resistant vWf, which indicates the absence of a pool of stored processed vWf. In addition, no Weibel-Palade body-like structure was detected in these cells by immunofluorescence labeling with anti-vWf antiserum. Electron microscopy and immunocytochemistry of RIN 5F cells expressing the pro-vWf mutant confirmed the absence of Weibel-Palade body-like structures. In addition, anti-vWf-linked gold particles were found in the ER, occasionally in rounded granules and particularly in lysosomal structures which were abundant. We conclude that the formation of large aggregates is not sufficient to induce efficient vWf storage, and that the lack of cleavage of the prosequence may direct the mutant pro-vWf molecule to a degradative pathway. Therefore, the prosequence cleavage is a requirement for vWf storage.

  12. Philipp Frank, Richard von Mises, and the Frank-Mises

    NASA Astrophysics Data System (ADS)

    Siegmund-Schultze, Reinhard

    2007-01-01

    The theoretical physicist Philipp Frank (1884 1966) and the applied mathematician Richard von Mises (1883 1953) both received their university education in Vienna shortly after 1900 and became friends at the latest during the Great War.They were attached to the Vienna Circle of Logical Positivists and wrote an influential two-part work on the differential and integral equations of mechanics and physics, the Frank-Mises, of 1925 and 1927, with its second edition following in 1930 and 1935.This work originated in the lectures that the mathematician Bernhard Riemann (1826 1866) delivered on partial differential equations and their applications to physical questions at the University of Göttingen between 1854 and 1862, which were edited and published posthumously in1869 by the physicist Karl Hattendorff (1834 1882).The immediate precursor of the Frank-Mises, however, was the extensive revision of Hattendorff’s edition of Riemann’s lectures that the mathematician Heinrich Weber (1842 1913) published in two volumes, the Riemann-Weber, of 1900 and 1901, with its second edition following in 1910 and 1912. I trace this historical lineage, explore the nature and contents of the Frank-Mises, and discuss its complementary relationship to the first volume of the text that the mathematicians Richard Courant (1888 1972) and David Hilbert (1862 1943) published on the methods of mathematical physics in 1924, the Courant-Hilbert,which, when it and its second volume of 1937 were translated into English and extensively revised in 1953 and 1961, eclipsed the classic Frank-Mises.

  13. Biology and Physics of von Willebrand Factor Concatamers

    PubMed Central

    Springer, Timothy A

    2014-01-01

    Structural specialisations enable von Willebrand factor (VWF) to assemble during biosynthesis into helical tubules in Weibel-Palade bodies (WPB). Specialisations include a pH-regulated dimeric bouquet formed by the C-terminal half of VWF and helical assembly guided by the N-terminal half that templates inter-dimer disulphide bridges. Orderly assembly and storage of ultra-long concatamers in helical tubules, without crosslinking of neighboring tubules, enables unfurling during secretion without entanglement. Length regulation occurs post-secretion, by hydrodynamic force-regulated unfolding of the VWF A2 domain, and its cleavage by the plasma protease ADAMTS13 (a disintegrin and metalloprotease with a thrombospondin type 1 motif, member 13). VWF is longest at its site of secretion, where its haemostatic function is most important. Moreover, elongational hydrodynamic forces on VWF are strongest just where needed, when bound to the vessel wall, or in elongational flow in the circulation at sites of vessel rupture or vasoconstriction in haemostasis. Elongational forces regulate haemostasis by activating binding of the A1 domain to platelet GPIbα, and over longer time periods, regulate VWF length by unfolding of the A2 domain for cleavage by ADAMTS13. Recent structures of A2 and single molecule measurements of A2 unfolding and cleavage by ADAMTS13 illuminate the mechanisms of VWF length regulation. Single molecule studies on the A1-GPIb receptor-ligand bond demonstrate a specialised flex-bond that enhances resistance to the strong hydrodynamic forces experienced at sites of haemorrhage. PMID:21781248

  14. Chemical control of Haplodiplosis marginata von Roser (Diptera: Cecidomyiidae).

    PubMed

    Censier, F; Chavalle, S; Wittouck, D; De Proft, M; Bodson, B

    2012-01-01

    The saddle gall midge, Haplodiplosis marginata (von Roser), has been detected in Belgium since 2010, after several decades without any reporting. It had indeed caused serious damages between 1965 and 1970. This insect is a European cereal pest whose larvae feed on stems and engender saddle-shaped depressions, resulting in yield losses. Face with the resurgence of this pest, it was decided to study its spatial distribution and, because serious damages were observed in some regions, to develop effective curative control. To date, chemical protection seems to be the only immediate solution in case of heavy emergences. Experimentation was conducted in a highly infested field (Meetkerke, Belgian Polders), according to a randomized complete blocks arrangement with four replications. Foremost, a lambdacyhalothrin-based insecticide was used to evaluate efficiency of several protection schemes, ranging between one and four spray(s). The large spread of flights observed during the 2011 spring allowed to highlight the effect of treatment date on the attack intensity and also on the galls distribution along the stem, on the different internodes: the lower internodes were protected by the early sprayings, while last sprayings induced reduction of galls number on the upper internodes. Moreover, several insecticides already registrated in cereals against aphids were compared for their efficacy against saddle gall midge. Studied pyrethroids have shown a very good efficacy, ranging between 75% and 87%, when applied twice with a 2 weeks interval. To be efficient, insecticide applications must thus be synchronized with the flights and egg-laying periods. Monitoring the phenology of flights is thus essential as part of integrated pest management against saddle gall midge.

  15. Factor VIII-von Willebrand factor binding defects in autosomal recessive von Willebrand disease type Normandy and in mild hemophilia A. New insights into factor VIII-von Willebrand factor interactions.

    PubMed

    Jacquemin, Marc

    2009-01-01

    This concise review is focused on genetic, molecular and clinical aspects of von Willebrand disease (VWD) type 2N and of mild hemophilia A due to mutations impairing FVIII-von Willebrand factor (VWF) interactions. Missense mutations in the VWF gene impairing the binding to FVIII do not impair the structure of VWF multimers nor the ability of VWF to aggregate platelets but causes an accelerated clearance of FVIII. Missense mutations in the FVIII gene impairing the binding to VWF are a common cause of mild/moderate hemophilia A. The implications of these observations for the treatment of patients with coagulation factor concentrates and desmopressin are discussed. Copyright (c) 2009 S. Karger AG, Basel.

  16. Energy & Climate: Getting Quantitative

    NASA Astrophysics Data System (ADS)

    Wolfson, Richard

    2011-11-01

    A noted environmentalist claims that buying an SUV instead of a regular car is energetically equivalent to leaving your refrigerator door open for seven years. A fossil-fuel apologist argues that solar energy is a pie-in-the-sky dream promulgated by na"ive environmentalists, because there's nowhere near enough solar energy to meet humankind's energy demand. A group advocating shutdown of the Vermont Yankee nuclear plant claims that 70% of its electrical energy is lost in transmission lines. Around the world, thousands agitate for climate action, under the numerical banner ``350.'' Neither the environmentalist, the fossil-fuel apologist, the antinuclear activists, nor most of those marching under the ``350'' banner can back up their assertions with quantitative arguments. Yet questions about energy and its environmental impacts almost always require quantitative answers. Physics can help! This poster gives some cogent examples, based on the newly published 2^nd edition of the author's textbook Energy, Environment, and Climate.

  17. Primary enzyme quantitation

    DOEpatents

    Saunders, G.C.

    1982-03-04

    The disclosure relates to the quantitation of a primary enzyme concentration by utilizing a substrate for the primary enzyme labeled with a second enzyme which is an indicator enzyme. Enzyme catalysis of the substrate occurs and results in release of the indicator enzyme in an amount directly proportional to the amount of primary enzyme present. By quantifying the free indicator enzyme one determines the amount of primary enzyme present.

  18. Quantitative traits and diversification.

    PubMed

    FitzJohn, Richard G

    2010-12-01

    Quantitative traits have long been hypothesized to affect speciation and extinction rates. For example, smaller body size or increased specialization may be associated with increased rates of diversification. Here, I present a phylogenetic likelihood-based method (quantitative state speciation and extinction [QuaSSE]) that can be used to test such hypotheses using extant character distributions. This approach assumes that diversification follows a birth-death process where speciation and extinction rates may vary with one or more traits that evolve under a diffusion model. Speciation and extinction rates may be arbitrary functions of the character state, allowing much flexibility in testing models of trait-dependent diversification. I test the approach using simulated phylogenies and show that a known relationship between speciation and a quantitative character could be recovered in up to 80% of the cases on large trees (500 species). Consistent with other approaches, detecting shifts in diversification due to differences in extinction rates was harder than when due to differences in speciation rates. Finally, I demonstrate the application of QuaSSE to investigate the correlation between body size and diversification in primates, concluding that clade-specific differences in diversification may be more important than size-dependent diversification in shaping the patterns of diversity within this group.

  19. Quantitation of signal transduction.

    PubMed

    Krauss, S; Brand, M D

    2000-12-01

    Conventional qualitative approaches to signal transduction provide powerful ways to explore the architecture and function of signaling pathways. However, at the level of the complete system, they do not fully depict the interactions between signaling and metabolic pathways and fail to give a manageable overview of the complexity that is often a feature of cellular signal transduction. Here, we introduce a quantitative experimental approach to signal transduction that helps to overcome these difficulties. We present a quantitative analysis of signal transduction during early mitogen stimulation of lymphocytes, with steady-state respiration rate as a convenient marker of metabolic stimulation. First, by inhibiting various key signaling pathways, we measure their relative importance in regulating respiration. About 80% of the input signal is conveyed via identifiable routes: 50% through pathways sensitive to inhibitors of protein kinase C and MAP kinase and 30% through pathways sensitive to an inhibitor of calcineurin. Second, we quantify how each of these pathways differentially stimulates functional units of reactions that produce and consume a key intermediate in respiration: the mitochondrial membrane potential. Both the PKC and calcineurin routes stimulate consumption more strongly than production, whereas the unidentified signaling routes stimulate production more than consumption, leading to no change in membrane potential despite increased respiration rate. The approach allows a quantitative description of the relative importance of signal transduction pathways and the routes by which they activate a specific cellular process. It should be widely applicable.

  20. Quantitation of mitral regurgitation.

    PubMed

    Topilsky, Yan; Grigioni, Francesco; Enriquez-Sarano, Maurice

    2011-01-01

    Mitral regurgitation (MR) is the most frequent valve disease. Nevertheless, evaluation of MR severity is difficult because standard color flow imaging is plagued by considerable pitfalls. Modern surgical indications in asymptomatic patients require precise assessment of MR severity. MR severity assessment is always comprehensive, utilizing all views and methods. Determining trivial/mild MR is usually easy, based on small jet and flow convergence. Specific signs of severe MR (pulmonary venous flow systolic reversal or severe mitral lesion) are useful but insensitive. Quantitative methods, quantitative Doppler (measuring stroke volumes) and flow convergence (aka PISA method), measure the lesion severity as effective regurgitant orifice (ERO) and volume overload as regurgitant volume (RVol). Interpretation of these numbers should be performed in context of specific MR type. In organic MR (intrinsic valve lesions) ERO ≥ 0.40 cm(2) and RVol ≥ 60 mL are associated with poor outcome, while in functional MR ERO ≥ 0.20 cm(2) and RVol ≥ 30 mL mark reduced survival. While MR assessment should always be comprehensive, quantitative assessment of MR provides measures that are strongly predictive of outcome and should be the preferred approach. The ERO and RVol measured by these methods require interpretation in causal context to best predict outcome and determine MR management. Copyright © 2011 Elsevier Inc. All rights reserved.

  1. The value of prior information for detection of QTL affecting longitudinal traits: an example using Von Bertalanffy growth function.

    PubMed

    Varona, L; Gómez-Raya, L; Rauw, W M; Ovilo, C; Clop, A; Noguera, J L

    2005-02-01

    A Bayesian procedure is presented for detecting quantitative trait loci (QTL) affecting longitudinal traits. The statistical model assumes a QTL affecting the prior distribution of the parameters of a given production function, under a hierarchical Bayesian scheme. Marginal posterior distributions for the effects associated with the QTL are calculated using Markov chain Monte Carlo methods. Furthermore, the Bayesian analysis allows the use of some available relevant information that can improve the detection of the QTL substantially. To illustrate the procedure, an example of QTL detection using the Von Bertalanffy growth function is presented with a F2 pig population bred from Iberian boars and Landrace sows. Animals of the F2 population were genotyped for seven markers in chromosome 2 (SSC2). Two prior distributions for the mean effect of the parameters related with birth and adult weight were compared. On the one hand, vague prior distributions were used, and, on the other, there were assumed univariate Gaussian distributions that ensure biologically meaningful adult and birth weights on the posterior growth curves. Results from the second prior distribution supported the presence of QTL, by showing that individuals with both alleles of Iberian origin had lower rates of maturation. On the contrary, when vague priors were used, the procedure was not able to detect QTL.

  2. IntegraTUM Teilprojekt E-Mail: Rezentralisierung von E-Mail-Services

    NASA Astrophysics Data System (ADS)

    Diehn, Max; Haarer, Ado; Schreiner, Alexander; Storz, Michael

    Das Teilprojekt E-Mail hatte ursprünglich die Aufgabe einen zentralen Mailservice mit verteilter Administration der Mailadressen für die TUM aufzubauen und diesen durch Anti-Spam- und Anti-Viren-Maßnahmen zu schützen. Auf diesen Mailservice sollten sowohl die am LRZ gehosteten Maildomains als auch die vielen lokal betriebenen Mailserver - soweit von deren Betreibern gewünscht - migriert werden. Neben einigen Rückschlägen und Hindernissen kam es im Laufe des Projektes auch zu einer Änderung der Anforderungen, sodass zum Ende des Projektes statt eines reinen Mailsystems ein Doppelsystem mit "shared SMTP address space" bestehend aus einem klassischen Message-Store mit POP/IMAP-Zugriff auf Basis von Postfix + Dovecot und einem Groupware-System auf Basis von Microsoft Exchange in Produktion ging, wobei jeder Mitarbeiter und Student der TUM wählen kann, auf welchem der beiden Systeme sich seine Mailbox befindet.

  3. P-selectin and von Willebrand factor in bovine mesenteric lymphatics: an immunofluorescent study.

    PubMed

    Di Nucci, A; Marchetti, C; Serafini, S; Piovella, F

    1996-03-01

    P-selectin (PADGEM, GMP-140, CD62) is an integral membrane protein specific to alpha granules of platelets and Weibel-Palade bodies of blood vascular endothelial cells. The presence in lymphatic endothelial cells of numerous Weibel-Palade bodies and their positivity to immunocytochemical reaction for von Willebrand factor have previously been characterized and described. Because von Willebrand factor and P-selectin codistribute in Weibel-Palade bodies of blood vascular endothelial cells we investigated the presence of both P-selectin and von Willebrand factor in lymphatic endothelium. Lymphatic vessels expressed positive reaction to immunocytochemical assay thereby demonstrating the presence of P-selectin in the endothelium. Distribution and intensity of the reaction were similar to those observed in bovine blood vascular endothelium.

  4. A historical perspective: Bernhard von Langenbeck German surgeon (1810-1887).

    PubMed

    Cesmebasi, Alper; Oelhafen, Kim; Shayota, Brian J; Klaassen, Zachary; Tubbs, R Shane; Loukas, Marios

    2014-10-01

    Bernhard von Langenbeck is undeniably one of the world's greatest surgeons and inventors. The influence which he exerted upon the practice of surgery, as apparent by the numerous surgical tools and 21 operations credited to his name, represents the notable contributions of this amazing man. Despite the tools and techniques which bear his name, the establishment of a surgical journal, and his role in co-founding the German Surgical Society, many attest that Bernhard von Langenbeck's greatest contribution to the professional field was the vast knowledge he imparted on his pupils. Commonly credited with training nearly every celebrated surgical operator of his time, von Langenbeck merits posthumous acknowledgement for his vast contributions to the field of medicine and surgery.

  5. An Alternative to Von Glasersfeld's Subjectivism in Science Education: Deweyan Social Constructivism

    NASA Astrophysics Data System (ADS)

    Garrison, Jim

    An influential view of constructivism in science and mathematics educational research and practice is that of Ernst von Glasersfeld. It is a peculiarly subjectivist form of constructivism that should not be attractive to science and mathematics educators concerned with retaining some sort of realism that leaves room for objectivity. The subjectivist constructivism of von Glasersfeld also becomes entangled in untenable mind/body and subject/object dualisms. Finally, these dualisms are unnecessary for social constructivism. I will provide one example of a social constructivist alternative to social constructivism, that of the pragmatic philosopher John Dewey. In presenting Dewey's position I will appeal to Ockham's razor, that is, the admonition not to multiply entities beyond necessity, to shave off the needless mentalistic and psychic entities that lead von Glasersfeld into his subjectivism and dualism.

  6. Modelling complex geological circular data with the projected normal distribution and mixtures of von Mises distributions

    NASA Astrophysics Data System (ADS)

    Lark, R. M.; Clifford, D.; Waters, C. N.

    2014-07-01

    Circular data are commonly encountered in the earth sciences and statistical descriptions and inferences about such data are necessary in structural geology. In this paper we compare two statistical distributions appropriate for complex circular data sets: the mixture of von Mises and the projected normal distribution. We show how the number of components in a mixture of von Mises distribution may be chosen, and how one may choose between the projected normal distribution and the mixture of von Mises for a particular data set. We illustrate these methods with a few structural geological data, showing how the fitted models can complement geological interpretation and permit statistical inference. One of our data sets suggests a special case of the projected normal distribution which we discuss briefly.

  7. Modelling complex geological angular data with the Projected Normal distribution and mixtures of von Mises distributions

    NASA Astrophysics Data System (ADS)

    Lark, R. M.; Clifford, D.; Waters, C. N.

    2013-12-01

    Angular data are commonly encountered in the earth sciences and statistical descriptions and inferences about such data are necessary in structural geology. In this paper we compare two statistical distributions appropriate for complex angular data sets: the mixture of von Mises and the projected normal distribution. We show how the number of components in a mixture of von Mises distribution may be chosen, and how one may chose between the projected normal distribution and mixture of von Mises for a particular data set. We illustrate these methods with some structural geological data, showing how the fitted models can complement geological interpretation and permit statistical inference. One of our data sets suggests a special case of the projected normal distribution which we discuss briefly.

  8. Hodgkin's disease in a patient with Von Hippel-Lindau disease. A case report.

    PubMed

    D'hondt, R; Thomas, J; Van Oosterom, A T; Dewolf-Peeters, C

    2000-01-01

    Von Hippel-Lindau (VHL) disease is an autosomal dominant inherited disorder with a predisposition to develop a wide variety of lesions: retinal, cerebellar, spinal and medullar hemangioblastomas, renal cell carcinomas, phaeochromocytomas, and renal, pancreatic and epididymal cysts are the most frequent manifestations of the disease. The prevalence of VHL disease has been estimated to be 1 per 36,000 persons. We report the case of a 68-year-old woman with Von Hipple-Lindau disease who developed high fever with pulmonary and hepatic lesions proven to be Hodgkin's disease on biopsy. To our knowledge, this is the first report of Hodgkin's disease in a patient with Von Hippel-Lindau.

  9. 78 FR 34090 - Lois Von Morganroth; Shiloh Warm Springs Ranch, LLC; Notice of Application for Transfer of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-06

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Lois Von Morganroth; Shiloh Warm Springs Ranch, LLC; Notice of Application for Transfer of License, and Soliciting Comments and Motions To Intervene On April 29, 2013, Lois Von Morganroth (transferor) and Shiloh...

  10. "'And They Lived Happily Ever After": The Fairy Tale of Radical Constructivism and Von Glasersfeld's Ethical Disengagement

    ERIC Educational Resources Information Center

    d'Agnese, Vasco

    2015-01-01

    Is von Glasersfeld's constructivism actually radical? In this article, I respond to this question by analyzing von Glasersfeld's main works. I argue that the essential theoretical move of radical constructivism--namely the assertion that reality is the construction of a human mind that only responds to the subjective perception of "what…

  11. Interaction of Platelet Membrane Receptors with von Willebrand Factor, Ristocetin, and the Fc Region of Immunoglobulin G

    PubMed Central

    Moore, Anne; Ross, Gordon D.; Nachman, Ralph L.

    1978-01-01

    The agglutination of human platelets by ristocetin and von Willebrand factor was inhibited by aggregated immunoglobulin (Ig)G and by Fc fragments of IgG, but not by Fab, F(ab′)2 or pFc fragments of IgG. Because this inhibition occurred with formalin-fixed platelets as well as with normal platelets, a generalized aggregation of fluid membrane components by Fc fragments was not responsible for this inhibition of ristocetin and von Willebrand factor-induced agglutination. Reciprocal inhibition of platelet Fc receptors was produced by prior incubation of platelets with von Willebrand factor and ristocetin. Sucrose density gradient ultracentrifugation studies demonstrated that aggregated IgG did not form fluid-phase complexes with von Willebrand factor and ristocetin. Furthermore, passage of von Willebrand factor and ristocetin through a column of immobilized heat-aggregated IgG did not alter platelet agglutinating activity which indicates that aggregated IgG did not inactivate von Willebrand factor or ristocetin. Thus, it was likely that the IgG-mediated interference with platelet agglutination by ristocetin and von Willebrand factor did not occur in the fluid phase but at the platelet surface. These studies suggest that the platelet membrane Fc receptor may be either a part of, or sterically related to, the membrane glycoprotein I complex that interacts with von Willebrand factor, and that occupation of one of these surface components blocks the availability of the other. PMID:309473

  12. "'And They Lived Happily Ever After": The Fairy Tale of Radical Constructivism and Von Glasersfeld's Ethical Disengagement

    ERIC Educational Resources Information Center

    d'Agnese, Vasco

    2015-01-01

    Is von Glasersfeld's constructivism actually radical? In this article, I respond to this question by analyzing von Glasersfeld's main works. I argue that the essential theoretical move of radical constructivism--namely the assertion that reality is the construction of a human mind that only responds to the subjective perception of "what…

  13. Genetic Drivers of von Willebrand Factor Levels in an Ischemic Stroke Population and Association With Risk for Recurrent Stroke.

    PubMed

    Williams, Stephen R; Hsu, Fang-Chi; Keene, Keith L; Chen, Wei-Min; Dzhivhuho, Godfrey; Rowles, Joe L; Southerland, Andrew M; Furie, Karen L; Rich, Stephen S; Worrall, Bradford B; Sale, Michèle M

    2017-06-01

    von Willebrand factor (vWF) plays an important role in thrombus formation during cerebrovascular damage. We sought to investigate the potential role of circulating vWF in recurrent cerebrovascular events and identify genetic contributors to variation in vWF level in an ischemic stroke population. We analyzed the effect of circulating vWF on risk of recurrent stroke using survival models in the VISP trial (Vitamin Intervention for Stroke Prevention) and the use of vWF in reclassification over traditional factors. We conducted a genome-wide association study) with imputation, based on 1000 Genomes Project data, for circulating vWF levels and then interrogated loci previously associated with vWF levels. We performed expression quantitative trait locus analysis for vWF across different tissues. Elevated vWF levels were associated with increased risk for recurrent stroke in VISP. Adding vWF to traditional clinical parameters also improved recurrent stroke risk prediction. We identified single-nucleotide polymorphisms significantly associated with circulating vWF at the ABO locus (P<5×10(-8)) and replicated findings from previous genetic associations of vWF levels in humans. Expression quantitative trait locus analyses demonstrate that most associated ABO single-nucleotide polymorphisms were also associated with vWF gene expression. Elevated vWF levels are associated with recurrent stroke in VISP. In the VISP population, genetic determinants of vWF levels that impact vWF gene expression were identified. These data add to our knowledge of the pathophysiologic and genetic basis for recurrent stroke risk and may have implications for clinical care decision making. © 2017 American Heart Association, Inc.

  14. (Never) Mind your p's and q's: Von Neumann versus Jordan on the foundations of quantum theory

    NASA Astrophysics Data System (ADS)

    Duncan, A.; Janssen, M.

    2013-03-01

    In 1927, in two papers entitled "On a new foundation [Neue Begründung] of quantum mechanics," Pascual Jordan presented his version of what came to be known as the Dirac-Jordan statistical transformation theory. Jordan and Paul Dirac arrived at essentially the same theory independently of one another at around the same time. Later in 1927, partly in response to Jordan and Dirac and avoiding the mathematical difficulties facing their approach, John von Neumann developed the modern Hilbert space formalism of quantum mechanics. We focus on Jordan and von Neumann. Central to the formalisms of both are expressions for conditional probabilities of finding some value for one quantity given the value of another. Beyond that Jordan and von Neumann had very different views about the appropriate formulation of problems in quantum mechanics. For Jordan, unable to let go of the analogy to classical mechanics, the solution of such problems required the identification of sets of canonically conjugate variables, i.e., p's and q's. For von Neumann, not constrained by the analogy to classical mechanics, it required only the identification of a maximal set of commuting operators with simultaneous eigenstates. He had no need for p's and q's. Jordan and von Neumann also stated the characteristic new rules for probabilities in quantum mechanics somewhat differently. Jordan and Dirac were the first to state those rules in full generality. Von Neumann rephrased them and, in a paper published a few months later, sought to derive them from more basic considerations. In this paper we reconstruct the central arguments of these 1927 papers by Jordan and von Neumann and of a paper on Jordan's approach by Hilbert, von Neumann, and Nordheim. We highlight those elements in these papers that bring out the gradual loosening of the ties between the new quantum formalism and classical mechanics. This paper was written as part of a joint project in the history of quantum physics of the Max Planck

  15. Species of Typhlophoros von Linstow, 1906 (Nematoda: Ascaridoidea) in Old World crocodilians.

    PubMed

    Sprent, J F

    1999-07-01

    A new species of the genus Typhlophoros von Linstow, 1906, T. spratti, is described from the freshwater crocodile Crocodylus johnstoni and the saltwater crocodile C. porosus in northern Australia. Specimens of the new species could not be compared with the type-species, T. lamellaris, as no preserved specimens of the latter species are known to exist. The new species differs from the descriptions of von Linstow (1906) and Maplestone (1930) in the number of interlabial ridges, the form of the ventriculus and absence of lateral alae. The taxonomic status and affinities of Typhlophoros are discussed.

  16. Aufnahme, Analyse und Visualisierung von Bewegungen nativer Herzklappen in-vitro

    NASA Astrophysics Data System (ADS)

    Weiß, Oliver; Friedl, Sven; Kondruweit, Markus; Wittenberg, Thomas

    Die hohe Zahl an Transplantationen von Herzklappen und viele nötige Re-Operationen machen eine detaillierte Analyse der Strömungen und Klappenbewegungen klinisch interessant. Ein neuer Ansatz ist hierbei der Einsatz von Hochgeschwindigkeitskameras um Bewegungsabl äufe der Herzklappen beobachten und auswerten zu können. Die hohen Datenraten erfordern allerdings eine möglichst automatisierte Analyse und möglichst komprimierte Darstellung des Schwingungsverhaltens. In dieser Arbeit wird ein Ansatz vorgestellt, bei dem Bewegungen nativer Herzklappen in-vitro aufgenommen, analysiert und kompakt visualisiert werden.

  17. [Adenocarcinoma of the endolymphatic sac in von Hippel-Lindau disease. A case report].

    PubMed

    Martínez-Miravete, P; Domínguez, P; Zubieta, J L; Manrique, M

    2007-01-01

    Tumors originating in the endolymphatic system are extremely rare, and very few articles have been published about this type of tumors. Up to 15% of cases are associated to von Hippel-Lindau disease. This article describes the case of a patient previously diagnosed with von Hippel-Landau disease that presented a sudden loss of hearing in the left ear. Specific imaging tests (computed tomography [CT] and magnetic resonance imaging [MRI]) showed the presence of a neoplasm originating in the left endolymphatic sac. Histological analysis of the surgical specimen determined it corresponded to an adenocarcinoma of the endolymphatic sac.

  18. Von Neumann entropy in a Rashba-Dresselhaus nanodot; dynamical electronic spin-orbit entanglement

    NASA Astrophysics Data System (ADS)

    Safaiee, Rosa; Golshan, Mohammad Mehdi

    2017-06-01

    The main purpose of the present article is to report the characteristics of von Neumann entropy, thereby, the electronic hybrid entanglement, in the heterojunction of two semiconductors, with due attention to the Rashba and Dresselhaus spin-orbit interactions. To this end, we cast the von Neumann entropy in terms of spin polarization and compute its time evolution; with a vast span of applications. It is assumed that gate potentials are applied to the heterojunction, providing a two dimensional parabolic confining potential (forming an isotropic nanodot at the junction), as well as means of controlling the spin-orbit couplings. The spin degeneracy is also removed, even at electronic zero momentum, by the presence of an external magnetic field which, in turn, leads to the appearance of Landau states. We then proceed by computing the time evolution of the corresponding von Neumann entropy from a separable (spin-polarized) initial state. The von Neumann entropy, as we show, indicates that electronic hybrid entanglement does occur between spin and two-dimensional Landau levels. Our results also show that von Neumann entropy, as well as the degree of spin-orbit entanglement, periodically collapses and revives. The characteristics of such behavior; period, amplitude, etc., are shown to be determined from the controllable external agents. Moreover, it is demonstrated that the phenomenon of collapse-revivals' in the behavior of von Neumann entropy, equivalently, electronic hybrid entanglement, is accompanied by plateaus (of great importance in quantum computation schemes) whose durations are, again, controlled by the external elements. Along these lines, we also make a comparison between effects of the two spin-orbit couplings on the entanglement (von Neumann entropy) characteristics. The finer details of the electronic hybrid entanglement, which may be easily verified through spin polarization measurements, are also accreted and discussed. The novel results of the present

  19. Angiodysplasia in von Willebrand Disease: Understanding the Clinical and Basic Science.

    PubMed

    Selvam, Soundarya; James, Paula

    2017-09-01

    Severe and intractable gastrointestinal bleeding caused by angiodysplasia is a debilitating problem for up to 20% of patients with von Willebrand disease (VWD). Currently, the lack of an optimal treatment for this recurrent problem presents an ongoing challenge for many physicians in their management of affected patients. Over the past few years, studies have pointed to a regulatory role for the hemostatic protein, von Willebrand factor (VWF), in angiogenesis, providing a novel target for the modulation of vessel development. This article will review the clinical implications and molecular pathology of angiodysplasia in VWD. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  20. Gastrointestinal complications of von Recklinghausen's disease: two case reports and a review of the literature.

    PubMed

    Pinsk, I; Dukhno, O; Ovnat, A; Levy, I

    2003-12-01

    There are few reports of the association between neurofibromatosis (von Recklinghausen's disease) and large, solid stromal tumours of the gastrointestinal tract. The prevalence of gastrointestinal involvement in von Recklinghausen's disease has been estimated at 11%-25%. Some associated gastrointestinal stromal tumours present clinically as bowel obstruction, perforation or gastrointestinal bleeding. We recently treated two patients with this condition who presented with gastrointestinal bleeding and were diagnosed with gastrointestinal stromal tumours. We report the unique aspects of these cases and discuss the diagnostic and management problems that are posed by this unusual association.

  1. An Integrated Approach to von Willebrand Disease and Surgical Myocardial Revascularization

    PubMed Central

    Jiritano, Federica; Cristodoro, Lucia; Bevacqua, Egidio; Malta, Emanuele; Mastroroberto, Pasquale

    2015-01-01

    Cardiac surgery in patients with preexisting bleeding disorders can be a challenge. Cardiopulmonary bypass can lead to bleeding disorders, above all in patients with coagulopathy. We report the case of a 42-year-old woman, with type I von Willebrand disease, who underwent off-pump coronary artery bypass grafting. Beating heart surgery associated with an adequate replacement of von Willebrand factor and factor VIII levels were chosen to prevent bleeding disorders. Her postoperative course was uneventful and she was discharged home after 5 postoperative days. PMID:26693126

  2. Spontaneous haemothorax associated with von Recklinghausen's disease: review of occurrence in Japan

    PubMed Central

    Miura, H.; Taira, O.; Uchida, O.; Usuda, J.; Hirai, S.; Kato, H.

    1997-01-01

    The case history is presented of a 61 year old man with von Recklinghausen's disease who developed a spontaneous haemothorax. In spite of being asymptomatic for five days after drainage, he died as a result of fatal sudden re-bleeding. The post mortem examination showed dissection and rupture of the left subclavian artery. Microscopically, disarrangement of smooth muscle and decrease of elastic fibre was observed in the ruptured artery. Haemothorax in patients with von Recklinghausen's disease may require thoracotomy, even if the condition of the patient appears to be stable. 


 PMID:9227730

  3. 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.

  4. Experimental Bullard-von Karman dynamo: MHD saturated regimes

    NASA Astrophysics Data System (ADS)

    Miralles, Sophie; Plihon, Nicolas; Pinton, Jean-François

    2014-05-01

    The dynamo instability, converting kinetic energy into magnetic energy, creates the magnetic fields of many astrophysical bodies for which the flows are highly turbulent. Those turbulent fluctuations restricts the range of parameters of numerical and theoretical predictions. As laboratory experiments are closer from natural parameters, this approach is favored in this work. In the past decades, dynamo action has been observed in experiments involving laminar flows [1] or fully turbulent flows [2] in liquid sodium. Nevertheless, the saturation of the velocity field by the Lorentz force due to the dynamo magnetic field is weak in those experiment because the control parameter is always close to the threshold of the instability (which is not the case in astrophysical situations). The details of the mechanism of the back reaction of Lorentz force on the flow are not known. We present here an experimental semi-synthetic dynamo, for which a fluid turbulent induction mechanism ('omega' effect) is associated to an external amplification applying a current into a pair of coils. The flow, called von-Karman, is produced by the counter rotation of two coaxial propellers in a cylindrical tank filled with liquid gallium. The resulting flow is highly turbulent (Re > 10 ^ 5). The amplification, mimicking a turbulent 'alpha' effect, allow to observe the dynamo instability at low magnetic Reynolds number (Rm ~ 2), far below the threshold of natural homogeneous dynamo. This experiment reaches non linear regimes, for which the saturation is a MHD process, at control parameter several times the critical value. The instability grows through an on-off intermittent regime evolving into a full MHD saturated regime for which the Lorentz force is in balance with the inertial one. The power budget is strongly modified by the dynamo magnetic field and we give an insight of the estimated rate of conversion of kinetic energy into magnetic one from experimental data. Very rich regimes such as

  5. Human von Willebrand factor/factor VIII concentrates in the management of pediatric patients with von Willebrand disease/hemophilia A

    PubMed Central

    Castaman, Giancarlo; Linari, Silvia

    2016-01-01

    Several plasma-derived intermediate and high-purity concentrates containing von Willebrand factor (VWF) and factor VIII (FVIII) are currently available. The main role of these products in the management of the pediatric population is represented by the replacement therapy in patients with severe or intermediate forms of von Willebrand disease, in whom other treatments are ineffective or contraindicated. Another important role of VWF/FVIII concentrates in children may be their use in immune tolerance induction (ITI) protocols. ITI is particularly recommended for hemophilia A children who have developed an inhibitor against FVIII, currently the most serious complication of substitutive treatment in hemophilia. Although recombinant concentrates may represent the preferred option in children with hemophilia A, VWF/FVIII concentrates may offer an advantage in rescuing patients who failed previous ITI. PMID:27445481

  6. Human von Willebrand factor/factor VIII concentrates in the management of pediatric patients with von Willebrand disease/hemophilia A.

    PubMed

    Castaman, Giancarlo; Linari, Silvia

    2016-01-01

    Several plasma-derived intermediate and high-purity concentrates containing von Willebrand factor (VWF) and factor VIII (FVIII) are currently available. The main role of these products in the management of the pediatric population is represented by the replacement therapy in patients with severe or intermediate forms of von Willebrand disease, in whom other treatments are ineffective or contraindicated. Another important role of VWF/FVIII concentrates in children may be their use in immune tolerance induction (ITI) protocols. ITI is particularly recommended for hemophilia A children who have developed an inhibitor against FVIII, currently the most serious complication of substitutive treatment in hemophilia. Although recombinant concentrates may represent the preferred option in children with hemophilia A, VWF/FVIII concentrates may offer an advantage in rescuing patients who failed previous ITI.

  7. On the history of Ludwig von Bertalanffy's "general systemology", and on its relationship to cybernetics - Part II: Contexts and developments of the systemological hermeneutics instigated by von Bertalanffy

    NASA Astrophysics Data System (ADS)

    Pouvreau, David

    2014-02-01

    The history of "general system theory" is investigated in order to clarify its meanings, vocations, foundations and achievements. It is characterized as the project of a science of the systemic interpretation of the "real", renamed here "general systemology". The contexts and modes of its elaboration, publication and implementation are discussed. The paper mostly focuses on the works of its instigator: Ludwig von Bertalanffy. However, general systemology was a collective project: the main contributions of other "systemologists", from the 1950s until the 1970s, are hence also considered. Its solidarity with the history of the Society for General Systems Research is notably discussed. A reconstruction of the systemological hermeneutics is undertaken on this basis. It finds out the potential systematic unity underlying the diversity of the contributions to this both scientific and philosophical project. Light is thus shed on the actual scope of von Bertalanffy's works.

  8. Designing quantitative telemedicine research.

    PubMed

    Wade, Victoria; Barnett, Adrian G; Martin-Khan, Melinda; Russell, Trevor

    2016-10-27

    When designing quantitative trials and evaluation of telehealth interventions, researchers should think ahead to the intended way that the intervention could be implemented in routine care and consider how trial participants with similar characteristics to the target population can be included. The telehealth intervention and the context in which it is placed should be clearly described, and consideration given to conducting pragmatic trials in order to show the effect of telehealth in complex environments with rapidly changing technology. Types of research designs, comparators and outcome measures are discussed and common statistical issues are introduced. © The Author(s) 2016.

  9. "The captain and canon" C. W. A. von Wahl (1760-1846) (German Title: "Der Hauptmann und Kanonikus" C. W. A. von Wahl (1760-1846) )

    NASA Astrophysics Data System (ADS)

    Brosche, Peter

    Von Wahl was an active member of the group of independent scholars, who were working in the German states within Goethe's time, and who performed astrometric and geodetic observations and calculations. Here we present some cornerstones of his life; longer intervals of it took place in Allstedt south of the Harz and in Halberstadt. Small scientific assets have been preserved at the Universitäts-Sternwarte Bonn. Therein, a lecture on secular variations of the ecliptic is of singular nature.

  10. Function of von Willebrand factor after crossed bone marrow transplantation between normal and von Willebrand disease pigs: effect on arterial thrombosis in chimeras.

    PubMed Central

    Nichols, T C; Samama, C M; Bellinger, D A; Roussi, J; Reddick, R L; Bonneau, M; Read, M S; Bailliart, O; Koch, G G; Vaiman, M

    1995-01-01

    von Willebrand factor (vWF) is essential for the induction of occlusive thrombosis in stenosed and injured pig arteries and for normal hemostasis. To separate the relative contribution of plasma and platelet vWF to arterial thrombosis, we produced chimeric normal and von Willebrand disease pigs by crossed bone marrow transplantation; von Willebrand disease (vWD) pigs were engrafted with normal pig bone marrow and normal pigs were engrafted with vWD bone marrow. Thrombosis developed in the chimeric normal pigs that showed normal levels of plasma vWF and an absence of platelet vWF; but no thrombosis occurred in the chimeric vWD pigs that demonstrated normal platelet vWF and an absence of plasma vWF. The ear bleeding times of the chimeric pigs were partially corrected by endogenous plasma vWF but not by platelet vWF. Our animal model demonstrated that vWF in the plasma compartment is essential for the development of arterial thrombosis and that it also contributes to the maintenance of bleeding time and hemostasis. Images Fig. 2 Fig. 3 PMID:7708664

  11. BOOK REVIEW: Meilensteine der Astronomie - Von Aristoteles bis Hawking

    NASA Astrophysics Data System (ADS)

    Duerbeck, H. W.; Hamel, J.

    2006-12-01

    A writer, more specific a writer on the history of astronomy, might from time to time look at the collected document folders with all the research material and reprints, and might wonder: has this been all? Especially at a time when recycling is in vogue? And, perhaps with a request or an invitation to submit something, he or she might consider re-using the material before its definitive disposal. Well, such are my feelings when I looked at Jurgen Hamel's new book Milestones of Astronomy - From Aristoteles to Hawking . A slight chance for survival of medium-sized publishers like Kosmos is to offer popular books, and a title must attract potential buyers: Aristoteles means the "old" times, and as concerns the "mad scientist" of modern times, Stephen Hawking has by now dethroned Einstein. In 1998, Hamel had published a Geschichte der Astronomie - Von den Anfangen bis zur Gegenwart (History of astronomy, from the beginnings to the present), which, of course, he could not simply copy. This time, he selected some stones from his research areas - milestones, touchstones, stumbling blocks in the long road of astronomical evolution - and put them between the covers of his new book. So let us look at these (mile)stones . The reader is informed about Aristoteles on 2 pages, but his medieval interpreter Johannes de Sacrobosco gets 8 pages! Copernicus' life and achievements are described on 9 pages, closely followed by his devotee and translator Rothmann with 8 pages; Copernicus' contemporary, Peter Apian, however, gets about 13! Bessel's and Herschel's lifes and works are described on well-deserved 13 and 15 pages, while the achievements of the two Lucasian professors, Isaac Newton and Stephen Hawking, are just outlined in a single paragraph! Thus, importance is sometimes inversely proportional to text length... But let us become serious now. Why should an active historian outline, for the hundreth time, the life of Copernicus, while there are so many interesting, and often

  12. Quantitative Hyperspectral Reflectance Imaging.

    PubMed

    Klein, Marvin E; Aalderink, Bernard J; Padoan, Roberto; De Bruin, Gerrit; Steemers, Ted A G

    2008-09-11

    Hyperspectral imaging is a non-destructive optical analysis technique that can for instance be used to obtain information from cultural heritage objects unavailable with conventional colour or multi-spectral photography. This technique can be used to distinguish and recognize materials, to enhance the visibility of faint or obscured features, to detect signs of degradation and study the effect of environmental conditions on the object. We describe the basic concept, working principles, construction and performance of a laboratory instrument specifically developed for the analysis of historical documents. The instrument measures calibrated spectral reflectance images at 70 wavelengths ranging from 365 to 1100 nm (near-ultraviolet, visible and near-infrared). By using a wavelength tunable narrow-bandwidth light-source, the light energy used to illuminate the measured object is minimal, so that any light-induced degradation can be excluded. Basic analysis of the hyperspectral data includes a qualitative comparison of the spectral images and the extraction of quantitative data such as mean spectral reflectance curves and statistical information from user-defined regions-of-interest. More sophisticated mathematical feature extraction and classification techniques can be used to map areas on the document, where different types of ink had been applied or where one ink shows various degrees of degradation. The developed quantitative hyperspectral imager is currently in use by the Nationaal Archief (National Archives of The Netherlands) to study degradation effects of artificial samples and original documents, exposed in their permanent exhibition area or stored in their deposit rooms.

  13. Is quantitative electromyography reliable?

    PubMed

    Cecere, F; Ruf, S; Pancherz, H

    1996-01-01

    The reliability of quantitative electromyography (EMG) of the masticatory muscles was investigated in 14 subjects without any signs or symptoms of temporomandibular disorders. Integrated EMG activity from the anterior temporalis and masseter muscles was recorded bilaterally by means of bipolar surface electrodes during chewing and biting activities. In the first experiment, the influence of electrode relocation was investigated. No influence of electrode relocation on the recorded EMG signal could be detected. In a second experiment, three sessions of EMG recordings during five different chewing and biting activities were performed in the morning (I); 1 hour later without intermediate removal of the electrodes (II); and in the afternoon, using new electrodes (III). The method errors for different time intervals (I-II and I-III errors) for each muscle and each function were calculated. Depending on the time interval between the EMG recordings, the muscles considered, and the function performed, the individual errors ranged from 5% to 63%. The method error increased significantly (P < .05 to P < .01) with the time interval between recordings. The error for the masseter (mean 27.2%) was higher than for the temporalis (mean 20.0%). The largest function error was found during maximal biting in intercuspal position (mean 23.1%). Based on the findings, quantitative electromyography of the masticatory muscles seems to have a limited value in diagnostics and in the evaluation of individual treatment results.

  14. Numerical solutions of the Von Karman equations for a thin plate

    SciTech Connect

    Da Silva, P.P.; Krauth, W.

    1997-04-01

    In this paper, we present an algorithm for the solution of the von Karman equations of elasticity theory and related problems. Our method of successive reconditioning is able to avoid convergence problems at any ratio of the nonlinear stretching and the pure bending energies. We illustrate the power of the method by numerical calculations of pinched or compressed plates subject to fixed boundaries.

  15. Perfecting the Individual: Wilhelm von Humboldt's Concept of Anthropology, "Bildung" and Mimesis

    ERIC Educational Resources Information Center

    Wulf, Christoph

    2003-01-01

    In the works of Wilhelm von Humboldt education took on a new quality, focusing firmly on the importance of the individual. "Bildung" was to become the principal task with a view to preparing the individual for the requirements of future life. In this article, the author investigates two aspects relating to the "Bildung" of the individual. First,…

  16. Von recklinghausen neurofibromatosis-pachydermatocele causing lower limb gigantism: a case report.

    PubMed

    Rekha, Arcot; Gopalan, T R

    2006-03-01

    Gigantism of the lower limb can occur because of plexiform neurofibromas. This condition is seen with café au lait patches and multiple neurofibromatosis in this case of von Recklinghausen neurofibromatosis. We report our patient and review literature of this uncommon condition.

  17. Untersuchung der Störwirkung von LTE auf SRD Anwendungen bei 868 MHz

    NASA Astrophysics Data System (ADS)

    Welpot, M.; Wunderlich, S.; Gaspard, I.

    2014-11-01

    Moderne Hausautomatisierungssysteme, Alarmanlagen oder auch Funk-Zugangssysteme in Haus und Automobil setzen auf frei nutzbare Frequenzen in ISM/SRD-Bändern. Die rasante Zunahme an privaten und kommerziell genutzten Applikationen im SRD-Band bei 868 MHz und der Ausbau der LTE-Mobilfunknetze im Frequenzbereich unterhalb von 1 GHz ("Digital Dividend") wirft zunehmend die Frage nach der Funkverträglichkeit dieser Systeme untereinander auf. Während die SRD-Funkmodule auf eine geringe Sendeleistung von ~ +14 dBm beschränkt sind (Ralf and Thomas, 2009), beträgt die maximale LTE-Sendeleistung im Uplink nach (ETSI-Norm, 2011) +23 dBm. Zusammen mit der Einführung von LTE im Frequenzbereich unterhalb 1 GHz als DSL-Ersatz vor allem in ländlichen Gebieten, ergibt sich damit als mögliches Störszenario, dass durch die Aussendung des LTE-Endgerätes im Bereich von ca. 850 MHz die SRD-Funkverbindungen bei 868 MHz insbesondere dann gestört werden, wenn die Antennen beider Funksysteme räumlich nahe zueinander angeordnet sind und folglich nur eine geringe zusätzliche Entkopplung der Systeme bieten. In der vorliegenden Arbeit wird das LTE-Störpotential auf SRD-Empfänger praxisnah untersucht.

  18. Von Steuben and the German Contribution to the American Revolution: A Selective Bibliography.

    ERIC Educational Resources Information Center

    Krewson, Margrit B.

    This Library of Congress selected bibliography highlights the efforts of Baron Friedrich Wilhelm von Steuben, other German and German-American military leaders, and the Hessian auxiliary military forces in assisting the American colonies during the Revolutionary War. The booklet is divided into five parts. Part 1 provides historical information…

  19. von Braun and Miller in the S-IVB Orbital Workshop

    NASA Technical Reports Server (NTRS)

    1968-01-01

    During a visit to the Marshall Space Flight Center (MSFC), the Congressional House Committee on Science and Astronautics toured the S-IVB workshop. Pictured here are MSFC's Dr. Wernher von Braun (standing) and Congressman Miller, Democratic representative of California (sitting on the ergometer bicycle) inside the workshop.

  20. Extrusion von ein- und mehrlumigen Katheterschläuchen aus thermoplastischen Kunststoffen

    NASA Astrophysics Data System (ADS)

    Wahl, Helmut

    In der Fertigung von medizinischen Katheterschläuchen werden thermoplastisch verarbeitbare Materialien wie z. B. Pebax, Polyamid, Polyurethan, Polyethylen oder Weich-PVC eingesetzt. Sämtliche zum Einsatz kommenden Materialien müssen für den medizinischen Einsatz zugelassen sein. Sie müssen in ihrer Zusammensetzung physiologisch unbedenklich sein.