Modeling the Formation of Clouds in Brown Dwarf Atmospheres

Because the opacity of clouds in substellar mass object (SMO) atmospheres depends on the composition and distribution of particle sizes within the cloud, a credible cloud model is essential for accurately modeling SMO spectra and colors. We present a one--dimensional model of cloud particle formation and subsequent growth based on a consideration of basic cloud microphysics. We apply this microphysical cloud model to a set of synthetic brown dwarf atmospheres spanning a broad range of surface gravities and effective temperatures (g_surf = 1.78 * 10^3 -- 3 * 10^5 cm/s^2 and T_eff = 600 -- 1600 K) to obtain plausible particle sizes for several abundant species (Fe, Mg2SiO4, and Ca2Al2SiO7). At the base of the clouds, where the particles are largest, the particle sizes thus computed range from ~5 microns to over 300 microns in radius over the full range of atmospheric conditions considered. We show that average particle sizes decrease significantly with increasing brown dwarf surface gravity. We also find that brown dwarfs with higher effective temperatures have characteristically larger cloud particles than those with lower effective temperatures. We therefore conclude that it is unrealistic when modeling SMO spectra to apply a single particle size distribution to the entire class of objects.Comment: 25 pages; 8 figures. We have added considerable detail describing the physics of the cloud model. We have also added discussions of the issues of rainout and the self-consistent coupling of clouds with brown dwarf atmospheric models. We have updated figures 1, 3, and 4 with new vertical axis labels and new particle sizes for forsterite and gehlenite. Accepted to the Astrophysical Journal, Dec. 2, 200

Two-Dimensional Hydrodynamic Simulations of Convection in Radiation-Dominated Accretion Disks

The standard equilibrium for radiation-dominated accretion disks has long been known to be viscously, thermally, and convectively unstable, but the nonlinear development of these instabilities---hence the actual state of such disks---has not yet been identified. By performing local two-dimensional hydrodynamic simulations of disks, we demonstrate that convective motions can release heat sufficiently rapidly as to substantially alter the vertical structure of the disk. If the dissipation rate within a vertical column is proportional to its mass, the disk settles into a new configuration thinner by a factor of two than the standard radiation-supported equilibrium. If, on the other hand, the vertically-integrated dissipation rate is proportional to the vertically-integrated total pressure, the disk is subject to the well-known thermal instability. Convection, however, biases the development of this instability toward collapse. The end result of such a collapse is a gas pressure-dominated equilibrium at the original column density.Comment: 10 pages, 7 figures, accepted for publication in ApJ. Please send comments to [email protected]

Effects on cycle control and bodyweight of the combined contraceptive ring, NuvaRing, versus an oral contraceptive containing 30 µg ethinyl estradiol and 3 mg drospirenone

BACKGROUND: The objective of this study was to compare cycle control, cycle-related characteristics and bodyweight effects of NuvaRing with those of a combined oral contraceptive (COC) containing 30 µg of ethinyl estradiol and 3 mg of drospirenone. METHODS: A randomized, multicentre, open-label trial in which 983 women were treated (intent-to-treat population) with NuvaRing or the COC for 13 cycles. RESULTS: Breakthrough bleeding or spotting during cycles 2-13 was in general less frequent with NuvaRing than that with the COC (4.7-10.4%) and showed a statistically significant odds ratio of 0.61 (95% confidence interval: 0.46, 0.80) with longitudinal analysis. Intended bleeding was significantly better for all cycles with NuvaRing (55.2-68.5%) than that with the COC (35.6-56.6%) (P < 0.01). Changes from baseline in mean bodyweight and body composition parameters were relatively small for both groups with no notable between-group differences. CONCLUSION: NuvaRing was associated with better cycle control than the COC, and there was no clinically relevant difference between the two groups in bodyweigh

Minimum wages and the China Syndrome: Causal evidence from US local labor markets

Exposure to Chinese import competition led to significant manufacturing job losses in the United States. Local labor markets, however, differ significantly in how they fared with respect to manufacturing employment. An important question is whether labor market institutions have an impact on the dynamic response of manufacturing employment to rising import penetration. We contribute to this debate by showing that minimum wages amplified the negative effect of Chinese import penetration on manufacturing employment in US local labor markets between 2000 and 2007. We develop a rigorous double-edged identification strategy. First, we construct shift-share instrumental variables to address the endogeneity of import penetration. Second, we use a border identification strategy to distinguish the effects of minimum wage policies from the effects of other local labor market characteristics that are unrelated to policy. Specifically, we rely on comparing commuting zones that are contiguous to each other but located in different states with different minimum wage policies. The approach essentially considers what happens to the response of manufacturing employment to import penetration when one crosses a policy border

Accretion of Chaplygin gas upon black holes: Formation of faster outflowing winds

We study the accretion of modified Chaplygin gas upon different types of black hole. Modified Chaplygin gas is one of the best candidates for a combined model of dark matter and dark energy. In addition, from a field theoretical point of view the modified Chaplygin gas model is equivalent to that of a scalar field having a self-interacting potential. We formulate the equations related to both spherical accretion and disc accretion, and respective winds. The corresponding numerical solutions of the flow, particularly of velocity, are presented and are analyzed. We show that the accretion-wind system of modified Chaplygin gas dramatically alters the wind solutions, producing faster winds, upon changes in physical parameters, while accretion solutions qualitatively remain unaffected. This implies that modified Chaplygin gas is more prone to produce outflow which is the natural consequence of the dark energy into the system.Comment: 21 pages including 7 figures; published in Classical and Quantum Gravit

Gravity in International Finance: Evidence From Fees on Equity Transactions

We shed light on the impact of institutional quality and information barriers on trade in financial services using a novel panel data set on revenue earned on domestic and crossborder equity securities underwriting transactions. Our data set covers 91,51

Comparison of the caries-protective effect of fluoride varnish with treatment as usual in nursery school attendees receiving preventive oral health support through the Childsmile oral health improvement programme - the Protecting Teeth@3 Study:a randomised controlled trial

Background: The Scottish Government set out its policy on addressing the poor oral health of Scottish children in 2005. This led to the establishment of Childsmile, a national programme designed to improve the oral health of children in Scotland. One element of the programme promotes daily tooth brushing in all nurseries in Scotland (Childsmile Core). A second targeted component (Childsmile Nursery) offers twice-yearly application of fluoride varnish to children attending nurseries in deprived areas. Studies suggest that fluoride varnish application can reduce caries in both adult and child populations. This trial aims to explore the effectiveness and cost-effectiveness of additional preventive value fluoride varnish application compared to Childsmile Core. Methods/Design: The Protecting Teeth@3 Study is an ongoing 2 year parallel group randomised treatment as usual controlled trial. Three-year-old children attending the ante pre-school year are randomised (1:1) to the intervention arm (fluoride varnish &#38; treatment as usual) or the control arm (treatment as usual). Children in the intervention arm will have Duraphat® fluoride varnish painted on the primary tooth surfaces and will continue to receive treatment as usual: the core Childsmile Nursery intervention. Children in the treatment as usual arm will receive the same series of contacts, without the application of varnish and will also continue with the Childsmile Core intervention. Interventions are undertaken by Childsmile trained extended duty dental nurses at six-monthly intervals. Participants receive a baseline dental inspection in nursery and an endpoint inspection in Primary 1 at the age of 5 years old. We will use primary and secondary outcome measures to compare the effectiveness of Duraphat® fluoride varnish plus treatment as usual with treatment as usual only in preventing any further dental decay. We will also undertake a full economic evaluation of the trial

The European Hematology Association Roadmap for European Hematology Research: a consensus document

The European Hematology Association (EHA) Roadmap for European Hematology Research highlights major achievements in diagnosis and treatment of blood disorders and identifies the greatest unmet clinical and scientific needs in those areas to enable better funded, more focused European hematology research. Initiated by the EHA, around 300 experts contributed to the consensus document, which will help European policy makers, research funders, research organizations, researchers, and patient groups make better informed decisions on hematology research. It also aims to raise public awareness of the burden of blood disorders on European society, which purely in economic terms is estimated at €23 billion per year, a level of cost that is not matched in current European hematology research funding. In recent decades, hematology research has improved our fundamental understanding of the biology of blood disorders, and has improved diagnostics and treatments, sometimes in revolutionary ways. This progress highlights the potential of focused basic research programs such as this EHA Roadmap. The EHA Roadmap identifies nine ‘sections’ in hematology: normal hematopoiesis, malignant lymphoid and myeloid diseases, anemias and related diseases, platelet disorders, blood coagulation and hemostatic disorders, transfusion medicine, infections in hematology, and hematopoietic stem cell transplantation. These sections span 60 smaller groups of diseases or disorders. The EHA Roadmap identifies priorities and needs across the field of hematology, including those to develop targeted therapies based on genomic profiling and chemical biology, to eradicate minimal residual malignant disease, and to develop cellular immunotherapies, combination treatments, gene therapies, hematopoietic stem cell treatments, and treatments that are better tolerated by elderly patients

The European Hematology Association Roadmap for European Hematology Research. A Consensus Document

Abstract The European Hematology Association (EHA) Roadmap for European Hematology Research highlights major achievements in diagnosis and treatment of blood disorders and identifies the greatest unmet clinical and scientific needs in those areas to enable better funded, more focused European hematology research. Initiated by the EHA, around 300 experts contributed to the consensus document, which will help European policy makers, research funders, research organizations, researchers, and patient groups make better informed decisions on hematology research. It also aims to raise public awareness of the burden of blood disorders on European society, which purely in economic terms is estimated at Euro 23 billion per year, a level of cost that is not matched in current European hematology research funding. In recent decades, hematology research has improved our fundamental understanding of the biology of blood disorders, and has improved diagnostics and treatments, sometimes in revolutionary ways. This progress highlights the potential of focused basic research programs such as this EHA Roadmap. The EHA Roadmap identifies nine sections in hematology: normal hematopoiesis, malignant lymphoid and myeloid diseases, anemias and related diseases, platelet disorders, blood coagulation and hemostatic disorders, transfusion medicine, infections in hematology, and hematopoietic stem cell transplantation. These sections span 60 smaller groups of diseases or disorders. The EHA Roadmap identifies priorities and needs across the field of hematology, including those to develop targeted therapies based on genomic profiling and chemical biology, to eradicate minimal residual malignant disease, and to develop cellular immunotherapies, combination treatments, gene therapies, hematopoietic stem cell treatments, and treatments that are better tolerated by elderly patients. Received December 15, 2015. Accepted January 27, 2016. Copyright © 2016, Ferrata Storti Foundatio