Acne resolution rates: Results of a single-blind, randomized, controlled, parallel phase III trial with EE/CMA (Belara (R)) and EE/LNG (Microgynon (R))

Background and Objective: Acne in women can often be successfully treated by the intake of oral contraceptives containing gestagens with anti-androgenic properties. This study aimed to evaluate the efficacy of the monophasic oral contraceptive ethinylestradiol/chlormadinone acetate (EE/CMA; Belara (R)) for the treatment of mild to moderate papulopustular acne of the face and acne-related disorders in comparison to EE/levonorgestrel (LNG; Microgynon (R)). Methods: 199 female acne patients were enrolled in a single-blind, randomized, multicentre phase III study and divided into two groups who received either EE/CMA or EE/LNG. The primary end point was fulfilled if the number of papules/pustules per half of the face present on admission had decreased by at least 50% in the 12th medication cycle. Results: 59.4% of the women under EE/CMA and 45.9% under EE/LNG were responders. The relative frequency of women with complete resolution was 16.5% under EE/CMA and 4.3% under EE/LNG at cycle 12. Conclusion: EE/CMA is an efficient treatment for women with mild and moderate papulopustular acne of the face and related disorders, reflecting the well-known anti-androgenic properties of the progestogen CMA. Copyright (C) 2001 S, Karger AG, Basel

Progress in transition metal-based enantioselective catalysis

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemistry, 2008.Vita.Includes bibliographical references.In Chapter 1, the first enantioselective cross-coupling reactions of racemic secondary benzylic halides are described (eq 1). This method was applied to the syntheses of intermediates employed by other groups in the generation of bioactive compounds, e.g., an androgen receptor agonist (1.1) and two members of the trikentrin family of natural products (1.2 and 1.3). In Chapter 2, the first method for the kinetic resolution of indolines through catalytic Nacylation is described (eq 2). To improve the selectivity factor, a new planar-chiral PPY-erived catalyst (2.1) was prepared, wherein the chiral environment had been modified. The method was applied to the resolution of an intermediate prepared by K. Tsuji in the synthesis of a series of novel antibiotics of core structure 2.2. This work provides a rare example of a nonenzyme-based acylation catalyst for the kinetic resolution of amines. Finally, in Chapter 3, the first examples of catalyzed, enantioselective insertion of carbenoid fragments into C-N sigma bonds are described (eq 3). The system uses commercially-available catalyst components and gives highly enantioselective rearrangements of benzylamine-, allylamine-, and [alpha]-aminocarbonyl-containing substrates. The method represents a new way to access 1,4-benzoxazinones, a subunit present in several pharmaceutical targets and chiral natural products.by Forrest O. Arp.Ph.D

Configurational entropy of Wigner crystals

We present a theoretical study of classical Wigner crystals in two- and three-dimensional isotropic parabolic traps aiming at understanding and quantifying the configurational uncertainty due to the presence of multiple stable configurations. Strongly interacting systems of classical charged particles confined in traps are known to form regular structures. The number of distinct arrangements grows very rapidly with the number of particles, many of these arrangements have quite low occurrence probabilities and often the lowest-energy structure is not the most probable one. We perform numerical simulations on systems containing up to 100 particles interacting through Coulomb and Yukawa forces, and show that the total number of metastable configurations is not a well defined and representative quantity. Instead, we propose to rely on the configurational entropy as a robust and objective measure of uncertainty. The configurational entropy can be understood as the logarithm of the effective number of states; it is insensitive to the presence of overlooked low-probability states and can be reliably determined even within a limited time of a simulation or an experiment.Comment: 12 pages, 8 figures. This is an author-created, un-copyedited version of an article accepted for publication in J. Phys.: Condens. Matter. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The definitive publisher-authenticated version is available online at 10.1088/0953-8984/23/7/075302.

A bias in optical observations of high redshift luminous infrared galaxies

We present evidence for the dramatically different morphology between the rest frame UV and 7micron mid-IR emission of VV114 and Arp299, two nearby (z~0) violently interacting infrared luminous galaxies (LIRGs). Nearly all LIRGs are interacting systems and it is currently accepted that they dominate the IR emission at z>1. Luminous IR galaxies located at z=1-2 could easily be detected as unresolved sources in deep optical/near-IR ground based surveys, as well as in upcoming 24micron surveys with the Space Infrared Telescope Facility. We demonstrate that the spatial resolution of these surveys will result in blending of the emission from unresolved interacting components. An increased scatter will thus be introduced in the observed optical to mid-IR colors of these galaxies, leading to a systematic underestimation of their dust content.Comment: To appear in the Astrophysical Journal Letters (4 pages 1 figure

The Distribution of Redshifts in New Samples of Quasi-stellar Objects

Two new samples of QSOs have been constructed from recent surveys to test the hypothesis that the redshift distribution of bright QSOs is periodic in $\log(1+z)$. The first of these comprises 57 different redshifts among all known close pairs or multiple QSOs, with image separations $\leq$ 10\arcsec, and the second consists of 39 QSOs selected through their X-ray emission and their proximity to bright comparatively nearby active galaxies. The redshift distributions of the samples are found to exhibit distinct peaks with a periodic separation of $\sim 0.089$ in $\log(1+z)$ identical to that claimed in earlier samples but now extended out to higher redshift peaks $z = 2.63, 3.45$ and 4.47, predicted by the formula but never seen before. The periodicity is also seen in a third sample, the 78 QSOs of the 3C and 3CR catalogues. It is present in these three datasets at an overall significance level $10^{-5}$ - $10^{-6}$, and appears not to be explicable by spectroscopic or similar selection effects. Possible interpretations are briefly discussed.Comment: submitted for publication in the Astronomical Journal, 15 figure

Lopsided Galaxies, Weak Interactions and Boosting the Star Formation Rate

To investigate the link between weak tidal interactions in disk galaxies and the boosting of their recent star formation, we obtain images and spatially integrated spectra (3615A < lambda < 5315A) for 40 late-type spiral galaxies (Sab-Sbc) with varying degrees of lopsidedness (a dynamical indicator of weak interactions). We quantify lopsidedness as the amplitude of the m=1 Fourier component of the azimuthal surface brightness distribution, averaged over a range of radii. We compare the young stellar content, quantified by EW(H\delta_abs) and the strength of the 4000 Angstrom break (D_4000), with lopsidedness and find a 3-4 sigma correlation between the two. We also find a 3.2 sigma correlation between EW(H\beta_emission) and lopsidedness. Using the evolutionary population synthesis code of Bruzual & Charlot we model the spectra as an ``underlying population'' and a superimposed ``boost population'' with the aim of constraining the fractional boost in the SFR averaged over the past 0.5 Gyr (the characteristic lifetime of lopsidedness). From the difference in both EW(H\delta_abs) and D_4000 between the most and least symmetric thirds of our sample, we infer that ~ 1x10^9 M_solar of stars are formed over the duration of a lopsided event in addition to the ``underlying'' SFH (assuming a final galactic stellar mass of 10^10 M_solar). This corresponds to a factor of 8 increase in the SFR over the past 5x10^8 years. For the nuclear spectra, all of the above correlations except D_4000 vs. are weaker than for the disk, indicating that in lopsided galaxies, the SF boost is not dominated by the nucleus.Comment: 35 pages, including 10 figures, to appear in the Astrophysical Journal, abridged abstrac

Surface photometry of new nearby dwarf galaxies

We present CCD surface photometry of 16 nearby dwarf galaxies, many of which were only recently discovered. Our sample comprises both isolated galaxies and galaxies that are members of nearby galaxy groups. The observations were obtained in the Johnson B and V bands (and in some cases in Kron-Cousins I). We derive surface brightness profiles, total magnitudes, and integrated colors. For the 11 galaxies in our sample with distance estimates the absolute B magnitudes lie in the range of -10>Mb>-13. The central surface brightness ranges from 22.5 to 27.0 mag/sq.arcsec. Most of the dwarf galaxies show exponential light profiles with or without a central light depression. Integrated radial color gradients, where present, appear to indicate a more centrally concentrated younger population and a more extended older population.Comment: accepted by A&

Blue Straggler Stars: Early Observations that Failed to Solve the Problem

In this chapter, I describe early ideas on blue stragglers, and various observations (some published, some not) that promised but failed to resolve the question of their origin. I review the data and ideas that were circulating from Allan Sandage's original discovery in 1953 of "anomalous blue stars" in the globular cluster M3, up until about 1992, when what seems to have been the only previous meeting devoted to Blue Straggler Stars (BSSs) was held at the Space Telescope Science Institute.Comment: Chapter 2, in Ecology of Blue Straggler Stars, H.M.J. Boffin, G. Carraro & G. Beccari (Eds), Astrophysics and Space Science Library, Springe

Hydrologic control of nitrogenremoval, storage and export in a mountain stream

Nutrient cycling and export in streams and rivers should vary with flow regime, yet most studies of stream nutrient transformation do not include hydrologic variability. We used a stable isotope tracer of nitrogen (15N) to measure nitrate (NO3-) uptake, storage, and export in a mountain stream, Spring Creek, Idaho, U.S.A. We conducted two tracer tests of 2-week duration during snowmelt and baseflow. Dissolved and particulate forms of 15N were monitored over three seasons to test the hypothesis that stream N cycling would be dominated by export during floods, and storage during low flow. Floods exported more N than during baseflow conditions; however, snowmelt floods had higher than expected demand for NO3- because of hyporheic exchange. residence times of benthic N during both tracer tests were longer than 100 d for ephemeral pools such as benthic algae and wood biofilms. Residence times were much longer in fine detritus, insects, and the particulate N from the hyporheic zone, showing that assimilation and hydrologic storage can be important mechanisms for retaining particulate N. Of the tracer N stored in the stream, the primary form of export was via seston during periods of high flows, produced by summer rainstorms or spring snowmelt the following year. Spring Creek is not necessarily a conduit for nutrients during high flow; hydrologic exchange between the stream and its valley represents an important storage mechanism