On the differentiability of Cauchy horizons

Chrusciel and Galloway constructed a Cauchy horizon that is nondifferentiable on a dense set. We prove that in a certain class of Cauchy horizons densely nondifferentiable Cauchy horizons are generic. We show that our class of densely nondifferentiable Cauchy horizons implies the existence of densely nondifferentiable Cauchy horizons arising from partial Cauchy surfaces and also the existence of densely nondifferentiable black hole event horizons.Comment: 9 pages, LaTe

Primary Crystallization of High Chromium Cast Steel in Metastable Conditions

The analysis of the primary crystallization of wear corrosive-erosive high chromium cast steel was introduced in the article on the basis of investigations the widened method of the differential thermal analysis with testers DTA-C and DTA-Is. The use of these testers enabled the analysis of crystallization for the various rates of cooling

Generalized Strong Curvature Singularities and Cosmic Censorship

A new definition of a strong curvature singularity is proposed. This definition is motivated by the definitions given by Tipler and Krolak, but is significantly different and more general. All causal geodesics terminating at these new singularities, which we call generalized strong curvature singularities, are classified into three possible types; the classification is based on certain relations between the curvature strength of the singularities and the causal structure in their neighborhood. A cosmic censorship theorem is formulated and proved which shows that only one class of generalized strong curvature singularities, corresponding to a single type of geodesics according to our classification, can be naked. Implications of this result for the cosmic censorship hypothesis are indicated.Comment: LaTeX, 11 pages, no figures, to appear in Mod. Phys. Lett.

Prevalence and patterns of cigarette smoking before and during early and late pregnancy according to maternal characteristics: the first national data based on the 2003 birth certificate revision, United States, 2016

The objective of this study was to examine the prevalence of smoking by intensity status before pregnancy and during early (first and second trimester) and late (third trimester) pregnancy according to race/ethnicity, age, and educational attainment of women who gave birth in the United States in 2016.https://doi.org/10.1186/s12978-019-0807-

Aterektomia laserowa ELCA (excimer laser coronary atherectomy) — stan obecny i perspektywy

Przezskórna angiopastyka wieńcowa (PCI) z implantacją stentu uwalniającego lek antyproliferacyjny jest obecnie zasadniczą metodą leczenia istotnych zwężeń w zakresie tętnic wieńcowych. Choć rzadkie, niepowodzenia PCI są najczęściej konsekwencją uwarunkowań anatomicznych, takich jak brak możliwości sforsowania zmiany cewnikiem balonowym lub optymalnego poszerzenia zwężenia. W tych sytuacjach pomocna może okazać się udoskonalona technologia lasera ekscymerowego (ELCA) umożliwiająca niszczenie opornych blaszek miażdżycowych. Dotychczasowe kliniczne doświadczenia z zastosowaniem ELCA pozwalają na wstępne zdefiniowanie obszarów jego zastosowania. W artykule przedstawiono aktualny stan wiedzy dotyczący mechanizmu działania, wskazań oraz wstępnych wyników z użyciem ECLA.Percutaneous coronary intervention (PCI) with drug eluting stent implantation is currently the recommended first-line treatment of the significant coronary stenosis. Although rare, the failure of PCI is often a consequence of unfavorable anatomical conditions, such as not being able to cross the lesion with balloon catheter or the optimal stenosis dilatation. In these situations, it may be helpful the use of excimer laser coronary atherectomy (ELCA), which allows the destruction of resistant arterial plaques. Previous experience with the use of ELCA allow to predefine the potential areas of its clinical application. The paper summarizes the current state of knowledge concerning the mechanism of ELCA, indications and preliminary results with using of the new ECLA systems