Limiting Behavior of Solutions to the Einstein-Yang/Mills Equations

The ADM masses of particle-like solutions to the Einstein-Yang/Mills Equations tend to 2 as the number of nodes of the solutions increases. The same result is true for black hole solutions with event horizon less than 1. For event horizon $\rho > 1$ the ADM masses converge to $\rho + \rho^{-1} .$ These statements extend and correct ``An Investigation at the Limiting Behavior of Particle-Like Solutions to the Einstein-Yang/Mills Equations and a New black Hole Solutions'', by J. A. Smoller and A. G. Wasserman, in Comm. Math. Phys., 161, 365-389, (1994).Comment: 2 pages, um594

Revisiting Generalized Chaplygin Gas as a Unified Dark Matter and Dark Energy Model

In this paper, we revisit generalized Chaplygin gas (GCG) model as a unified dark matter and dark energy model. The energy density of GCG model is given as $\rho_{GCG}/\rho_{GCG0}=[B_{s}+(1-B_{s})a^{-3(1+\alpha)}]^{1/(1+\alpha)}$, where $\alpha$ and $B_s$ are two model parameters which will be constrained by type Ia supernova as standard candles, baryon acoustic oscillation as standard rulers and the seventh year full WMAP data points. In this paper, we will not separate GCG into dark matter and dark energy parts any more as adopted in the literatures. By using Markov Chain Monte Carlo method, we find the result: $\alpha=0.00126_{- 0.00126- 0.00126}^{+ 0.000970+ 0.00268}$ and $B_s= 0.775_{- 0.0161- 0.0338}^{+ 0.0161+ 0.0307}$.Comment: 6 pages, 4 figure

A Brane World Perspective on the Cosmological Constant and the Hierarchy Problems

We elaborate on the recently proposed static brane world scenario, where the effective 4-D cosmological constant is exponentially small when parallel 3-branes are far apart. We extend this result to a compactified model with two positive tension branes. Besides an exponentially small effective 4-D cosmological constant, this model incorporates a Randall-Sundrum-like solution to the hierarchy problem. Furthermore, the exponential factors for the hierarchy problem and the cosmological constant problem obey an inequality that is satisfied in nature. This inequality implies that the cosmological constant problem can be explained if the hierarchy problem is understood. The basic idea generalizes to the multibrane world scenario. We discuss models with piecewise adjustable bulk cosmological constants (to be determined by the 5-dimensional Einstein equation), a key element of the scenario. We also discuss the global structure of this scenario and clarify the physical properties of the particle (Rindler) horizons that are present. Finally, we derive a 4-D effective theory in which all observers on all branes not separated by particle horizons measure the same Newton's constant and 4-D cosmological constant.Comment: revtex, 63 pages, 8 figures, one table, revised version, more discussions on the global structure, references adde

Modified Chaplygin Gas as a Unified Dark Matter and Dark Energy Model and Cosmic Constraints

A modified Chaplygin gas model (MCG), $\rho_{MCG}/\rho_{MCG0}=[B_{s}+(1-B_{s})a^{-3(1+B)(1+\alpha)}]^{1/(1+\alpha)}$, as a unified dark matter model and dark energy model is constrained by using current available cosmic observational data points which include type Ia supernovae, baryon acoustic oscillation and the seventh year full WMAP data points. As a contrast to the consideration in the literatures, we {\it do not} separate the MCG into two components, i.e. dark mater and dark energy component, but we take it as a whole energy component-a unified dark sector. By using Markov Chain Monte Carlo method, a tight constraint is obtained: $\alpha= 0.000727_{- 0.00140- 0.00234}^{+ 0.00142+ 0.00391}$, $B=0.000777_{- 0.000302- 0.000697}^{+ 0.000201+ 0.000915}$ and $B_s= 0.782_{- 0.0162- 0.0329}^{+ 0.0163+ 0.0307}$ .}Comment: 6 pages, 3 figure

On the Degeneracy Inherent in Observational Determination of the Dark Energy Equation of State

Using a specific model for the expansion rate of the Universe as a function of scale factor, it is demonstrated that the equation of state of the dark energy cannot be determined uniquely from observations at redshifts $z\lesssim{\rm a few}$ unless the fraction of the mass density of the Universe in nonrelativistic particles, $\Omega_M$, somehow can be found independently. A phenomenological model is employed to discuss the utility of additional constraints from the formation of large scale structure and the positions of CMB peaks in breaking the degeneracy among models for the dark energy.Comment: 12 pages, 3 figures. Several references adde

Inverse Power Law Quintessence with Non-Tracking Initial Conditions

A common property of popular models of quintessence dark energy is the convergence to a common solution from a large range of the initial conditions. We re-examine the popular inverse power-law model of quintessence (where the common solution is dubbed as the 'tracker') with particular attention to the initial conditions for the field and their influence on the evolution. We find that previously derived limits on the parameters of the potential in this model are valid only in a range of initial conditions. A reasonably sharp boundary lies where the initial energy density of the scalar field is equal to that of the background radiation component. An initial quintessence energy density above this equipartition value lead to a solution that will not have joined the tracker solution by the present epoch. These non-tracker solutions possess the property that their present equation of state is very compatible with the observed bounds and independent of the exponent of the potential.Comment: RevTEX4, 9 figure

Theotonio dos Santos (1936-2018), the revolutionary intellectual who pioneered dependency theory

This article analyzes the origins and development of the dependency theory through the life and work of Theotonio Dos Santos. His formative years at the academy and his early political activism in Brazil are examined, particularly, his time at the University of Brasilia with Vania Bambirra, Ruy Mauro Marini and André Gunder Frank ("the quartet"). This is followed by a discussion about their years of exile in Chile where the quartet regrouped at the Center for Socio-Economic Studies (ceso) of the University of Chile, and where they wrote their founding texts on dependency theory. Chile provided fertile ground for the development of this theory due to its intellectual climate, institutionality, and the country's political transformations in the late 1960s and early 1970s. The military overthrow of the Allende government on that fateful September 11th, 1973 forced the quartet once again into exile. The article continues with an analysis of Dos Santos' writings during his exile in Mexico and then back in Brazil. During this period he became involved with world system theory which culminated in the publication of his extensive trilogy on the contemporary crisis of capitalism and social theory

Discovery of widespread transcription initiation at microsatellites predictable by sequence-based deep neural network

Using the Cap Analysis of Gene Expression (CAGE) technology, the FANTOM5 consortium provided one of the most comprehensive maps of transcription start sites (TSSs) in several species. Strikingly, ~72% of them could not be assigned to a specific gene and initiate at unconventional regions, outside promoters or enhancers. Here, we probe these unassigned TSSs and show that, in all species studied, a significant fraction of CAGE peaks initiate at microsatellites, also called short tandem repeats (STRs). To confirm this transcription, we develop Cap Trap RNA-seq, a technology which combines cap trapping and long read MinION sequencing. We train sequence-based deep learning models able to predict CAGE signal at STRs with high accuracy. These models unveil the importance of STR surrounding sequences not only to distinguish STR classes, but also to predict the level of transcription initiation. Importantly, genetic variants linked to human diseases are preferentially found at STRs with high transcription initiation level, supporting the biological and clinical relevance of transcription initiation at STRs. Together, our results extend the repertoire of non-coding transcription associated with DNA tandem repeats and complexify STR polymorphism

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries