Micro structuring of transparent materials with NIR ns-laser pulses

A current challenge in laser processing is high precision micromachining of transparent materials, e.g. to manufacture micro-optical elements. This can be achieved amongst others by using laser induced backside wet etching. Research has been done by several groups in the last years. Most of the published results were obtained by using UV excimer lasers. Our approach deals withthe implementation of the technique for NIR laser sources. We investigated the effects of different pulse widths and repetitionrates on laser induced back side wet etching for 1064nm wavelength and for different absorbers

Totgeburt und plötzlicher Kindstod : Gemeinsamkeiten und Differenzen

Die Totgeburtenrate hat in entwickelten Ländern in den letzten 30 Jahren im Gegensatz zur neonatalen Sterblichkeit und der Häufigkeit des plötzlichen Kindstodes kaum abgenommen. Dies ist verwunderlich, da heute weit weniger Totgeburten aufgrund einer Plazentainsuffizienz, eines maternalen Diabetes mellitus, einer Präeklampsie, oder durch Rhesusinkompatibilität und fetale Aneuploidien auftreten. Dagegen steigt die Rate an ätiologisch ungeklärten Fällen von Totgeburten an. Die eindrücklichen Erfolge in der Prävention des plötzlichen Kindstods zeigen, dass auch ätiologisch ungeklärte Erkrankungen wirkungsvoll verhindert werden können. Rauchen und Adipositas, sowie übermäßige Gewichtszunahme als Risikofaktoren für den intrauterinen Fruchttod sind vor Eintritt der Schwangerschaft modifizierbar. Die Erkennung und Therapie von Diabetes mellitus, Gestationsdiabetes und arterieller Hypertonie sind effektive Maßnahmen in der Schwangerschaft zur Verringerung von Totgeburten. Die Geburtseinleitung am Termin wäre ebenfalls eine effektive Methode zur Vermeidung von Totgeburten, wobei für eine vermiedene Totgeburt etwa 300 Geburtseinleitungen mit den damit verbundenen Nachteilen notwendig wären. Abstract During the last 30 years the rate of stillbirths in industrial countries has remained nearly identical, while neonatal mortality und the incidence of the sudden infant death syndrome (SIDS) has declined significantly. This observation is in contrast to the decline of stillbirths due to placental insufficiency, maternal diabetes mellitus, preeclampsia, rhesus incompatibility and fetal aneuploidy. However, the incidence of unexplained stillbirths has increased. The decrease of the incidence of the sudden infant death syndrome proves that prevention of diseases of unknown origin is possible. Smoking, obesity and an excessive increase in body weight before pregnancy are modifiable risk factors for intrauterine stillbirth. The detection and treatment of diabetes mellitus, gestational diabetes and arterial hypertension are effective measures in pregnancy to reduce the risk for stillbirth. The induction of labor at term is also effective in the reduction of stillbirths, however, the burden of elective induction with all of the possible negative effects has to be balanced against the benefit of avoiding intrauterine deaths as approximately 300 labor inductions with the corresponding disadvantages, would be necessary to avoid 1 stillbirth

Interbank market friction-induced holdings of precautionary liquidity: implications for bank loan supply and monetary policy implementation

We analyze the impact of overnight interbank market frictions on bank loan supply when banks face idiosyncratic liquidity risk and discuss resulting implications for monetary policy implementation. Sufficiently pronounced interbank market frictions imply that banks hold positive or negative precautionary liquidity. Holding positive (negative) precautionary liquidity means that banks hold more (less) liquidity than they expect to need. As holding precautionary liquidity is costly, interbank market frictions negatively influence bank loan supply. However, by means of its standing facilities, the central bank not only offers an alternative to using the interbank market but also determines the costs of friction-induced holdings of positive or negative precautionary liquidity. Therefore, the facilities allow the central bank to influence banks’ expected liquidity costs, and thereby their loan supply, so that interbank market frictions need not be an impediment to monetary policy transmission

Tract-based spatial statistics to assess the neuroprotective effect of early erythropoietin on white matter development in preterm infants

In a randomized double-blind placebo-controlled trial, O'Gorman et al. show that administration of erythropoietin within the first 42 hours after preterm birth improves white matter development in preterm infants. Improvements are seen in the corpus callosum, the anterior and posterior limbs of the internal capsule, and the corticospinal tract bilaterall

Quantized gravitational waves in the Milne universe

The quantization of gravitational waves in the Milne universe is discussed. The relation between positive frequency functions of the gravitational waves in the Milne universe and those in the Minkowski universe is clarified. Implications to the one-bubble open inflation scenario are also discussed.Comment: 26 pages, 1 figure, revtex. submitted to Phys. Rev. D1

Topologically Alice Strings and Monopoles

Symmetry breaking can produce ``Alice'' strings, which alter scattered charges and carry monopole number and charge when twisted into loops. Alice behavior arises algebraically, when strings obstruct unbroken symmetries -- a fragile criterion. We give a topological criterion, compelling Alice behavior or deforming it away. Our criterion, that \pi_o(H) acts nontrivially on \pi_1(H), links topologically Alice strings to topological monopoles. We twist topologically Alice loops to form monopoles. We show that Alice strings of condensed matter systems (nematic liquid crystals, helium 3A, and related non-chiral Bose condensates and amorphous chiral superconductors) are topologically Alice, and support fundamental monopole charge when twisted into loops. Thus they might be observed indirectly, not as strings, but as loop-like point defects. We describe other models, showing Alice strings failing our topological criterion; and twisted Alice loops supporting deposited, but not fundamental, monopole number.Comment: 2 figures; this paper consolidates preprints hep-th/0304161 and hep-th/0304162, to appear in Phys. Rev.