13 research outputs found

    Dynamics of evaporative cooling in magnetically trapped atomic hydrogen

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    We study the evaporative cooling of magnetically trapped atomic hydrogen on the basis of the kinetic theory of a Bose gas. The dynamics of trapped atoms is described by the coupled differential equations, considering both the evaporation and dipolar spin relaxation processes. The numerical time-evolution calculations quantitatively agree with the recent experiment of Bose-Einstein condensation with atomic hydrogen. It is demonstrated that the balance between evaporative cooling and heating due to dipolar relaxation limits the number of condensates to 9x10^8 and the corresponding condensate fraction to a small value of 4% as observed experimentally.Comment: 5 pages, REVTeX, 3 eps figures, Phys. Rev. A in pres

    Many particle entanglement in two-component Bose-Einstein Condensates

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    We investigate schemes to dynamically create many particle entangled states of a two component Bose-Einstein condensate in a very short time proportional to 1/N where NN is the number of condensate particles. For small NN we compare exact numerical calculations with analytical semiclassical estimates and find very good agreement for N≥50N \geq 50. We also estimate the effect of decoherence on our scheme, study possible scenarios for measuring the entangled states, and investigate experimental imperfections.Comment: 12 pages, 8 figure

    StratIT– Ein Rahmenwerk zu den Inhalten von ITStrategien. Grundlegung und methodische Fundierung

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    Bis heute ist kein Konsens über die Inhalte von IT-Strategien vorhan-den. Daraus folgt eine gewisse Unsicherheit, wenn es gilt, die Themenbereiche einer IT-Strategie festzulegen. Dieser Missstand soll durch den Entwurf eines Rahmenwerks/Frameworks behoben werden. Die Fachgruppe Strategisches In-formationsmanagement der Gesellschaft für Informatik (GI-Fachgruppe SIM) hat sich zum Ziel gesetzt, ein entsprechendes Rahmenwerk zu entwickeln. Dieses dient dazu, die Erstellung von IT-Strategien zu unterstützen. Der vorlie-gende Beitrag beschreibt den aktuellen Stand der Arbeit und zeigt im Sinne einer Diskussionsgrundlage auf, in welche thematischen Perspektiven, Domä-nen und Elemente sich IT-Strategien gliedern lassen. Darüber hinaus werden die methodische und wissenschaftstheoretische Fundierung sowie der „modus operandi“ der Arbeitsgruppe beschrieben. Das Rahmenwerk „StratIT“ entsteht in Zusammenarbeit von Forschern und Praktikern

    A new swept-frequency permeameter for measuring the complex permeability of thin magnetic films

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    Uso de cetoanálogo na terapia da insuficiência renal canina Use of keto analogues in therapy of the renal failure in dogs

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    <abstract language="eng">The efficacy of keto acids and essential amino acids on a two-year-old female dog, Labrador, suffering from Leishmaniasis and acute renal failure was evaluated by clinical and laboratorial analyses based on urea and creatinine dosages. An improving in the animal general condition and an increasing in the appetite, activity and weight gain, were observed and favorably contributed to the treatment of the primary disease. Ketoanalogueswere oraly administered during 76 days and the levels of urea and creatinine remained within acceptable limits, even after this period of time. Ketoanaloguescontributed positively for the treatment of acute renal failure and appears to be an important alternative for the leishmaniasis treatment

    Co-dependence of HTLV-1 p12 and p8 Functions in Virus Persistence

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    HTLV-1 orf-I is linked to immune evasion, viral replication and persistence. Examining the orf-I sequence of 160 HTLV-1-infected individuals; we found polymorphism of orf-I that alters the relative amounts of p12 and its cleavage product p8. Three groups were identified on the basis of p12 and p8 expression: predominantly p12, predominantly p8 and balanced expression of p12 and p8. We found a significant association between balanced expression of p12 and p8 with high viral DNA loads, a correlate of disease development. To determine the individual roles of p12 and p8 in viral persistence, we constructed infectious molecular clones expressing p12 and p8 (D26), predominantly p12 (G29S) or predominantly p8 (N26). As we previously showed, cells expressing N26 had a higher level of virus transmission in vitro. However, when inoculated into Rhesus macaques, cells producing N26 virus caused only a partial seroconversion in 3 of 4 animals and only 1 of those animals was HTLV-1 DNA positive by PCR. None of the animals exposed to G29S virus seroconverted or had detectable viral DNA. In contrast, 3 of 4 animals exposed to D26 virus seroconverted and were HTLV-1 positive by PCR. In vitro studies in THP-1 cells suggested that expression of p8 was sufficient for productive infection of monocytes. Since orf-I plays a role in T-cell activation and recognition; we compared the CTL response elicited by CD4+ T-cells infected with the different HTLV-1 clones. Although supernatant p19 levels and viral DNA loads for all four infected lines were similar, a significant difference in Tax-specific HLA.A2-restricted killing was observed. Cells infected with Orf-I-knockout virus (12KO), G29S or N26 were killed by CTLs, whereas cells infected with D26 virus were resistant to CTL killing. These results indicate that efficient viral persistence and spread require the combined functions of p12 and p8
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