Suitability of function tests for the prediction of the fertility of cryopreserved stallion semen

Tielblatt, Inhaltsverzeichnis, Lebenslauf, Danksagung 1\. Einleitung 2\. Schriftum 3\. Material und Methoden 4\. Ergebnisse 5\. Diskussion 6\. Zusammenfassung 7\. Summary LiteraturverzeichnisDie alleinige Beurteilung der Spermienmotilität lässt keine sichere Prognose hinsichtlich der Befruchtungsfähigkeit von Hengstsperma zu. In der vorliegenden Untersuchung sollte daher die Eignung des Mukuspenetrationstests und der Bestimmung der Akrosinaktivität mittels Gelatinolyse für die Prüfung der Gefriertauglichkeit von Hengstsperma untersucht werden. In einem Vorversuch an drei Hengsten erwies sich die Durchführbarkeit beider Testverfahren. Im Hauptversuch wurden 25 Ejakulate von 13 Hengsten untersucht. Zusammenfassend konnte sowohl die Messung der Penetrationsstrecke beim Mukuspenetrationstest als auch die Bestimmung des Anteils lysisaktiver Spermatozoen mittels Gelatinolyse Unterschiede zwischen Nativ- und Tiefgefriersperma aufdecken. Diese Verfahren eignen sich folglich für die Prüfung der Gefriertauglichkeit von Hengstsperma.Sperm motility is an insufficient parameter to predict the fertility of stallion semen. Therefore, we examined the suitability of mucus penetration test and the determination of acrosin activity by gelatinolysis for the prediction of the semens fertility after cryopreservation. In a preliminary trial with three Stallions both methods were found to be feasible. In the main trial we examined 25 ejaculates of 13 stallions. The measurement of penetration distance in mucus penetration test and the determination of lytic active sperms by gelatinolysis showed differences between native and frozen semen and are suitable to examine the freezing capability of stallion semen

Striped quantum Hall phases

Recent experiments seem to confirm predictions that interactions lead to charge density wave ground states in higher Landau levels. These new ``correlated'' ground states of the quantum Hall system manifest themselves for example in a strongly anisotropic resistivity tensor. We give a brief introduction and overview of this new and emerging field.Comment: 10 pages, 1 figure, updated reference to experimental wor

Engineered platforms for topological superconductivity and Majorana zero modes

Among the major avenues that are being pursued for realizing quantum bits, the Majorana-based approach has been the most recent to be launched. It attempts to realize qubits that store quantum information in a topologically protected manner. The quantum information is protected by non-local storage in localized and well-separated Majorana zero modes, and manipulated by exploiting their non-abelian quantum statistics. Realizing these topological qubits is experimentally challenging, requiring superconductivity, helical electrons (created by spin–orbit coupling) and breaking of time-reversal symmetry to all cooperate in an uncomfortable alliance. Over the past decade, several candidate materials systems for realizing Majorana-based topological qubits have been explored, and there is accumulating, though still debated, evidence that zero modes are indeed being realized. This Review surveys the basic physical principles on which these approaches are based, the materials systems that are being developed and the current state of the field. We highlight both the progress that has been made and the challenges that still need to be overcome

Composite Fermions in Modulated Structures: Transport and Surface Acoustic Waves

Motivated by a recent experiment of Willett et al. [Phys. Rev. Lett. 78, 4478 (1997)], we employ semiclassical composite-fermion theory to study the effect of a periodic density modulation on a quantum Hall system near Landau level filling factor nu=1/2. We show that even a weak density modulation leads to dramatic changes in surface-acoustic-wave (SAW) propagation, and propose an explanation for several key features of the experimental observations. We predict that properly arranged dc transport measurements would show a structure similar to that seen in SAW measurements.Comment: Version published in Phys. Rev. Lett. Figures changed to show SAW velocity shift. LaTeX, 5 pages, two included postscript figure

Catilina und die Parteikämpfe in Rom der Jahre 66-63

http://tartu.ester.ee/record=b1601520~S1*es

Geschichte der spartanischen und thebanischen Hegemonie vom Königsfrieden bis zur Schlacht bei Mantinea

http://tartu.ester.ee/record=b1594838~S1*es

Feynman problem in the noncommutative case

In the context of the Feynman's derivation of electrodynamics, we show that noncommutativity allows other particle dynamics than the standard formalism of electrodynamics.Comment: latex, 7 pages, no figure