Lower Wenlock black shales in the northern Holy Cross Mountains, Poland: Sedimentary and geochemical controls on the Ireviken Event in a deep marine setting

The stratigraphic variability and geochemistry of Llandovery/Wenlock (L/W) Series boundary sediments in Poland reveals that hemipelagic sedimentation under an anoxic/euxinic water column was interrupted by low density bottom currents or detached diluted turbid layers that resulted in intermittent seafloor oxygenation. TOC values and inorganic proxies throughout the Wilków 1 borehole section suggest variable redox conditions. U/Mo ratios >1 throughout much of the Aeronian and Telychian Stages, together with an absence of pyrite framboids, suggests oxygenated conditions prevailed. However, elevated TOC near the Aeronian/Telychian boundary, together with increased U/Th and V/(V+Ni) ratios and populations of small pyrite framboids are consistent with the development of dysoxic/anoxic conditions at that time. U/Th, V/Cr and V/(V+Ni) ratios, as well as Uauthig and Mo concentrations suggest that during the Ireviken black shale (IBS) deposition, bottom-water conditions deteriorated from oxic during the Telychian to mostly suboxic/anoxic immediately prior to the L/W boundary, before a brief reoxygenation at the end of the IBS sedimentation in the Sheinwoodian Stage. Rapid fluctuations in U/Mo during the Ireviken Event (IE) are characteristic of fluctuating redox conditions that culminated in an anoxic/euxinic seafloor in the Sheinwoodian. Following IBS deposition, conditions once again became oxygen deficient with the development of a euxinic zone in the water column. The Aeronian to Sheinwoodian deep-water redox history was unstable, and rapid fluctuations of the chemocline across the L/W Series boundary probably contributed to the IE extinctions, which affected mainly pelagic and hemipelagic fauna

A Simple Way of Calculating Cosmological Relic Density

A simple procedure is presented which leads to a dramatic simplification in the calculation of the relic density of stable particles in the Universe.Comment: 7 pages in LaTex, no figures; University of Michigan preprint UM-TH-94-02 (February 1994). Changes: a coefficient in $b^0$ (Eq. 16) corrected; added Acknowledgements and revised Note Added; plain LaTex only (no need to use RevTex

Ge-substitutional defects and the r3xr3 <--> 3x3 transition in alpha--SnGe(111)

The structure and energetics of Ge substitutional defects on the alpha-Sn/Ge(111) surface are analyzed using Density Functional Theory (DFT) molecular dynamics (MD) simulations. An isolated Ge defect induces a very local distortion of the 3x3 reconstruction, confined to a significant downwards displacement (-0.31 A) at the defect site and a modest upward displacement (0.05 A) of the three Sn nearest neighbours with partially occupied dangling bonds. Dynamical fluctuations between the two degenerate ground states yield the six-fold symmetry observed around a defect in the experiments at room temperature. Defect-defect interactions are controlled by the energetics of the deformation of the 3x3 structure: They are negligible for defects on the honeycomb lattice and quite large for a third defect on the hexagonal lattice, explaining the low temperature defect ordering.Comment: 4 pages, Revtex, 7 Encapsulated Postscript figures, uses epsf.sty. Submitted to Phys. Rev. Let

Ground state energy of the modified Nambu-Goto string

We calculate, using zeta function regularization method, semiclassical energy of the Nambu-Goto string supplemented with the boundary, Gauss-Bonnet term in the action and discuss the tachyonic ground state problem.Comment: 10 pages, LaTeX, 2 figure

Zastosowanie selektywnych modulatorów receptora progesteronowego w leczeniu mięśniaków macicy oraz ich przyszłość w ginekologii

Uterine leiomyomata are benign, monoclonal tumors arising from smooth muscle cells, which belong to one of the most common pathologies of the female genital system. Current pharmacotherapies (oral contraceptives, progestins, GnRH analogs) are ineffective or of limited use for long-term treatment. Although there is still much debate regarding their etiology, it is very likely that progesterone and progesterone receptor play a key role in their development. Profound importance of progesterone in the female reproductive system has led to discovery of synthetic progesterone receptor ligands, which can poses the activity ranging from pure agonist activity, trough mixed agonist/antagonist activity, to pure antagonist activity. Development of selective progesterone receptor modulators (SPRM) has created new therapeutic options and has great potential in a number of gynecologic indications. So far, ulipristal acetate has been approved for emergency contraception, mifepristone as a progesterone receptor antagonist because of the unique property of this compound for termination of pregnancy. Recently, the European Commission has authorized ulipristal acetate for the pre-operative treatment of uterine fibroids. Superior efficacy of ulipristal acetate versus placebo, to reduce excessive uterine bleeding and to reduce total fibroid volume prior to surgery was demonstrated. Moreover, non-inferior efficacy of ulipristal acetate versus Gonadotropin Releasing Hormone (GnRH)-agonist to reduce excessive uterine bleeding prior to surgery of uterine fibroids has been documented. Ulipristal acetate is also characterized by a superior side-effect profile in comparison to leuprolide acetate in terms of serum estradiol levels and the proportion of patients with moderate-to-severe hot flashes during treatment. Regarding safety profile, except elevation of liver enzymes after telapristone and onapristone treatment, to date no serious untoward effects of other SPRM have been reported. The issue of endometrial effects of these compounds remains to be resolved, although observation that intrinsic agonist activity of SPRM prevents endometrial proliferation may suggest future use of these agents in prevention of endometrial hyperplasia. Other promising applications, including endometriosis, endometrial cancer, Cushing’s disease, Alzheimer disease or long-term contraception, are currently in development.Mięśniaki macicy to łagodne, monoklonalne guzy wywodzące się z komórek mięśni gładkich należące do najczęstszych patologii układu rozrodczego kobiet. Ich etiologia pozostaje ciągle tematem otwartej debaty, jakkolwiek wydaje się, iż kluczową rolę w ich rozwoju odgrywa progesteron oraz receptor progesteronowy. Dotychczasowe zachowawcze metody leczenia mięśniaków (doustna antykoncepcja, gestageny lub analogi GnRH) są nieskuteczne bądź niemożliwe do stosowania w długotrwałej terapii. Pojawienie się selektywnych modulatorów receptora progesteronowego (SPRM) otworzyło nowe możliwości terapeutyczne. Obecnie preparaty te są zarejestrowane w doraźnej antykoncepcji, terminacji ciąży i w leczeniu mięśniaków. Ponadto na etapie badań klinicznych trwają próby zastosowania SPRM w leczeniu endometriozy, raka endometrium, choroby Cushinga, choroby Alzheimera czy w długotrwałej antykoncepcji

Boundary terms in Nambu-Goto string action

We investigate classical strings defined by the Nambu-Goto action with the boundary term added. We demonstrate that the latter term has a significant bearing on the string dynamics. It is confirmed that new action terms that depend on higher order derivatives of string coordinates cannot be considered as continuous perturbations from the starting string functional. In the case the boundary term reduces to the Gauss-Bonnet term, a stability analysis is performed on the rotating rigid string solution. We determined the most generic solution that the fluctuations grow to. Longitudinal string excitations are found. The Regge trajectories are nonlinear.Comment: 9 LaTeX pages and 3 PostScript figures (uuencoded), preprint TPJU-15/9

On the twin paradox in static spacetimes: I. Schwarzschild metric

Motivated by a conjecture put forward by Abramowicz and Bajtlik we reconsider the twin paradox in static spacetimes. According to a well known theorem in Lorentzian geometry the longest timelike worldline between two given points is the unique geodesic line without points conjugate to the initial point on the segment joining the two points. We calculate the proper times for static twins, for twins moving on a circular orbit (if it is a geodesic) around a centre of symmetry and for twins travelling on outgoing and ingoing radial timelike geodesics. We show that the twins on the radial geodesic worldlines are always the oldest ones and we explicitly find the conjugate points (if they exist) outside the relevant segments. As it is of its own mathematical interest, we find general Jacobi vector fields on the geodesic lines under consideration. In the first part of the work we investigate Schwarzschild geometry.Comment: 18 pages, paper accepted for publication in Gen. Rel. Gra

Rotunda na Kopcu Krakusa?

The paper focuses on the question of a mysterious building on the top of Krakus burial mound (Cracow, Poland) which was documented on some engravings from the late 16th and 17th century presenting panoramas of the city of Cracow (Matthäus Merian, 1617; and Eric Dahlberg, 1655). On the Swedish map from 1702 the top of the mound is already empty. The hypothesis is that probably a small Romanesque rotunda stood there. The facility established over a big burial mound resembles the case of St. Nicholas (Sv. Nikola) church in Nin (Croatia) which is an early Romanesque rotunda (triconchos)&nbsp; rom ca. 1100 AD which stands till today on the top of a prehistoric mound. In Cracow excavation done on Krakus mound in 30ties eventually revealed a negative of destroyed foundations od the rotunda, which remained uninterpreted.The paper focuses on the question of a mysterious building on the top of Krakus burial mound (Cracow, Poland) which was documented on some engravings from the late 16th and 17th century presenting panoramas of the city of Cracow (Matthäus Merian, 1617; and Eric Dahlberg, 1655). On the Swedish map from 1702 the top of the mound is already empty. The hypothesis is that probably a small Romanesque rotunda stood there. The facility established over a big burial mound resembles the case of St. Nicholas (Sv. Nikola) church in Nin (Croatia) which is an early Romanesque rotunda (triconchos)&nbsp; rom ca. 1100 AD which stands till today on the top of a prehistoric mound. In Cracow excavation done on Krakus mound in 30ties eventually revealed a negative of destroyed foundations od the rotunda, which remained uninterpreted