Der Bau des Milchstraßensystems

Rede in der Feierstunde am 30. April 196

Application of the Phase-Space Path Integral to Strong-Laser-Field-Assisted Electron-Ion Radiative Recombination: A Gauge-Covariant Formulation

We consider the problem of the choice of gauge in nonrelativistic strong-laser-field physics. For this purpose, we use the phase-space path-integral formalism to obtain the momentum-space matrix element of the exact time-evolution operator. With the assumption that the physical transition amplitude corresponds to transitions between eigenstates of the physical energy operator rather than the unperturbed Hamiltonian H0=(−i∂/∂r)2/2+V(r), we prove that the aforementioned momentum-space matrix elements obtained in velocity gauge and length gauge are equal. These results are applied to laser-assisted electron-ion radiative recombination (LAR). The transition amplitude comes out identical in length gauge and velocity gauge, and the expression agrees with the one conventionally obtained in length gauge. In addition to the strong-field approximation (SFA), which is the zeroth-order term of our expansion, we present explicit results for the first-order and the second-order terms, which correspond to LAR preceded by single and double scattering, respectively. Our general conclusion is that in applications to atomic processes in strong-field physics the length-gauge version of the SFA (and its higher-order corrections) should be used. Using the energy operator as the basis-defining Hamiltonian, we have shown that the resulting transition amplitude is gauge invariant and agrees with the form commonly derived in length gauge

Massage und Heilgymnastik: Sammelreferat über die im Jahre 1909 erschienenen Arbeiten (Soweit dieselben nicht im Original vorlagen, wurden zugängliche Referate benutzt)

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FFA im Spannungsfeld zwischen fremdsprachlicher Fachausbildung und fachspezifischer Fremdsprachenausbildung

An zahlreichen deutschen Hochschulen gibt es zusätzlich zu grundständigen rechtswissenschaftlichen Studiengängen auch Lehrangebote zu Grundlagen nichtdeutscher Rechtssysteme, für die sich der Terminus „Fachspezifische Fremdsprachenausbildung (für Juristinnen und Juristen)" (FFA) etabliert hat. Zunächst werden einige Merkmale des anglo-amerikanischen Rechts (common law) vorgestellt. Am Beispiel der Münsteraner FFA wird ein integratives Konzept juristischer und fachsprachlich ausgerichteter Kurse vorgestellt. Anhand von Kursevaluationen und der Forschungsergebnisse des interdisziplinären Forschungsprojekts „Verhaltensmuster englischer und deutscher Juristen und ihre Vermittlung in der Juristenausbildung" wird gezeigt, dass die Studierenden dazu tendieren, Sprachprobleme als Fachprobleme wahrzunehmen und eher zu einer fremdsprachlichen Fachausbildung tendieren. Daraus werden curriculare und didaktische Konsequenzen für die FFA entwickelt, die die Erwartungen der Studierenden aufgreifen sollen und den sprachlichen Anforderungen gerecht werden können

Kiri Karl Morgensternile, Neustadt

http://tartu.ester.ee/record=b1742076~S1*es

Kiri Karl Morgensternile, Dresden

http://tartu.ester.ee/record=b1745001~S1*es

Let It Flow: Morpholino Knockdown in Zebrafish Embryos Reveals a Pro-Angiogenic Effect of the Metalloprotease Meprin α2

BACKGROUND: Meprin metalloproteases are thought to be involved in basic physiological functions such as cell proliferation and tissue differentiation. However, the specific functions of these enzymes are still ambiguous, although a variety of growth factors and structural proteins have been identified as meprin substrates. The discovery of meprins alpha(1), alpha(2) and beta in teleost fish provided the basis for uncovering their physiological functions by gene silencing in vivo. METHODOLOGY/PRINCIPAL FINDINGS: A Morpholino knockdown in zebrafish embryos targeting meprin alpha(1) and beta mRNA caused defects in general tissue differentiation. But meprin alpha(2) morphants were affected more specifically and showed severe failures in the formation of the vascular system provoking the hypothesis of a pro-angiogenic effect. The blood circulation was largely diminished resulting in erythrocyte accumulation. These phenotypes mimic a previously described VEGF-A morphant, revealing a possible role of meprin alpha in VEGF-A activation. Indeed, human recombinant meprin alpha processed the vascular endothelial growth factor-A (VEGF-A) specifically, revealing the same cleavage products detectable for VEGF from zebrafish whole lysate. CONCLUSIONS/SIGNIFICANCE: Our results demonstrate that meprin metalloproteases are important for cell differentiation and proliferation already during embryogenesis, predominantly by the activation of growth factors. Thus, we conclude that meprins play a significant role in VEGF-A processing, subsequently regulating angiogenesis. Therefore, meprin alpha might be a new therapeutic target in cardiovascular diseases or in tumor growth inhibition