The central density of R136 in 30 Doradus

The central density rho_0 of a stellar cluster is an important physical parameter for determining its evolutionary and dynamical state. How much mass segregation there is, or whether the cluster has undergone core collapse both depends on rho_0. We reanalyze the results of a previous paper that gives the mass density profile of R136 and combine them with both a conservative upper limit for the core parameter and a more uncertain recent measurement. We thus place a lower limit on rho_0 under reasonable and defensible assumptions about the IMF, finding rho_0 >~ 1.5x10^4 Msun/pc^3 for the conservative assumption a < 0.4 pc for the cluster core parameter. If we use the lower, but more uncertain value a = 0.025 pc, the central density estimate becomes greater than 10^7 Msun/pc^3. A mechanism based on the destruction of a large number of circumstellar disks is posited to explain the hitherto unexplained increase in reddening presented in that same work.Comment: 6 pages, 2 figure

Multiple imputation of time series: an application to the construction of historical price indexes

Time series in many areas of application, and notably in the social sciences, are frequently incomplete. This is particularly annoying when we need to have complete data, for instance to compute indexes as a weighted average of values from a number of time series; whenever a single datum is absent, the index cannot be computed. This paper proposes to deal with such situations by creating multiple completed trajectories, drawing on state space modelling of time series, the simulation smoother and multiple imputation ideas.multiple imputation, time series analysis, Kalman smooth

Gender differences in psychological factors shaping smoking decisions of Chilean adolescents

This study examined gender differences in how internalizing and externalizing symptoms affect adolescents’ decisions about smoking in Chile, where girls smoke at some of the highest rates in the world. In multivariate logistic regression analyses with 607 adolescents, internalizing symptoms, such as depressed mood and anxiety, predicted smoking among girls more than boys, with girls who were low in internalizing symptoms being more likely to smoke than those who were high in internalizing symptoms. In Chile’s high-risk context, internalizing symptoms may be indirectly protective for girls by decreasing their exposure to peer pressure and related influences that encourage cigarette use.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This study was funded by the U.S. National Institute on Drug Abuse (Grant R01-DA-022720). (R01-DA-022720 - U.S. National Institute on Drug Abuse)http://europepmc.org/backend/ptpmcrender.fcgi?accid=PMC5014729&blobtype=pdfhttp://europepmc.org/backend/ptpmcrender.fcgi?accid=PMC5014729&blobtype=pdfAccepted manuscrip

Productivity of Nations: a Stochastic Frontier Approach to Tfp Decomposition

This Paper Tackles the Problem of Aggregate Tfp Measurement Using Stochastic Frontier Analysis (Sfa). Data From Penn World Table 6.1 are Used to Estimate a World Production Frontier For a Sample of 75 Countries Over a Long Period (1950-2000) Taking Advantage of the Model Offered By Battese and Coelli (1992). We Also Apply the Decomposition of Tfp Suggested By Bauer (1990) and Kumbhakar (2000) to a Smaller Sample of 36 Countries Over the Period 1970-2000 in Order to Evaluate the Effects of Changes in Efficiency (Technical and Allocative), Scale Effects and Technical Change. This Allows Us to Analyze the Role of Productivity and Its Components in Economic Growth of Developed and Developing Nations in Addition to the Importance of Factor Accumulation. Although not Much Explored in the Study of Economic Growth, Frontier Techniques Seem to Be of Particular Interest For That Purpose Since the Separation of Efficiency Effects and Technical Change Has a Direct Interpretation in Terms of the Catch-Up Debate. The Estimated Technical Efficiency Scores Reveal the Efficiency of Nations in the Production of Non Tradable Goods Since the Gdp Series Used is Ppp-Adjusted. We Also Provide a Second Set of Efficiency Scores Corrected in Order to Reveal Efficiency in the Production of Tradable Goods and Rank Them. When Compared to the Rankings of Productivity Indexes Offered By Non-Frontier Studies of Hall and Jones (1996) and Islam (1995) Our Ranking Shows a Somewhat More Intuitive Order of Countries. Rankings of the Technical Change and Scale Effects Components of Tfp Change are Also Very Intuitive. We Also Show That Productivity is Responsible For Virtually All the Differences of Performance Between Developed and Developing Countries in Terms of Rates of Growth of Income Per Worker. More Important, We Find That Changes in Allocative Efficiency Play a Crucial Role in Explaining Differences in the Productivity of Developed and Developing Nations, Even Larger Than the One Played By the Technology Gap

Productivity of Nations: a stochastic frontier approach to TFP decomposition

This paper tackles the problem of aggregate TFP measurement using stochastic frontier analysis (SFA). Data from Penn World Table 6.1 are used to estimate a world production frontier for a sample of 75 countries over a long period (1950-2000) taking advantage of the model offered by Battese & Coelli (1992). We also apply the decomposition of TFP suggested by Bauer (1990) and Kumbhakar (2000) to a smaller sample of 36 countries over the period 1970-2000 in order to evaluate the effects of changes in efficiency (technical and allocative), scale effects and technical change. This allows us to analyze the role of productivity and its components in economic growth of developed and developing nations in addition to the importance of factor accumulation. Although not much explored in the study of economic growth, frontier techniques seem to be of particular interest for that purpose since the separation of efficiency effects and technical change has a direct interpretation in terms of the catch-up debate. The estimated technical efficiency scores reveal the efficiency of nations in the production of non tradable goods since the GDP series used is PPP-adjusted. We also provide a second set of efficiency scores corrected in order to reveal efficiency in the production of tradable goods and rank them. When compared to the rankings of productivity indexes offered by non-frontier studies of Hall & Jones (1996) and Islam (1995) our ranking shows a somewhat more intuitive order of countries. Rankings of the technical change and scale effects components of TFP change are also very intuitive. We also show that productivity is responsible for virtually all the differences of performance between developed and developing countries in terms of rates of growth of income per worker. More important, we find that changes in allocative efficiency play an important role in explaining differences in the productivity of developed and developing nations, even larger than the one played by the technology gap.Total factor productivity, stochastic frontiers, technical change, technical efficiency, allocative efficiency, scale efficiency, convergence

The Induction of Oxidative/Nitrosative Stress, Inflammation, and Apoptosis by a Ferric Carboxymaltose Copy Compared to Iron Sucrose in a Non-Clinical Model

Introduction: Ferric carboxymaltose is a next-generation polynuclear iron(III)-hydroxide carbohydrate complex for intravenous iron therapy belonging to the class of so-called non-biological complex drugs. The product characteristics and therapeutic performance of non-biological complex drugs are largely defined by the manufacturing process. A follow-on product, termed herein as ferric carboxymaltose similar, is available in India. Given that non-biological complex drugs may display differences in diverse product properties not characterisable by physico-chemical methods alone. Aim: The aim is to assess the effects of this ferric carboxymaltose similar in our non-clinical model in non-anaemic healthy rats. Materials and Methods: Non-anaemic rats were treated with intravenous ferric carboxymaltose similar or iron sucrose both at (40 mg iron/kg body weight), or with saline solution (control) for four weeks, after which the animals were sacrificed. Parameters for tissue iron distribution, oxidative stress, nitrosative stress, inflammation and apoptosis were assessed by immunohistomorphometry. Results: Ferric carboxymaltose similar resulted in deranged iron distribution versus iron sucrose originator as indicated by increased serum iron, transferrin saturation and tissue iron(III) deposits as well as decreased ferritin deposits in the liver, heart and kidneys versus iron sucrose originator. Ferric carboxymaltose similar also increased significantly oxidative/nitrosative stress, pro-inflammatory, and apoptosis markers in the liver, heart and kidneys versus iron sucrose originator. Conclusion: In our rat model, ferric carboxymaltose similar had a less favourable safety profile than iron sucrose originator, adversely affecting iron deposition, oxidative and nitrosative stress, inflammatory responses, with impaired liver and kidney function.Fil: Toblli, Jorge Eduardo. Hospital Alemán; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cao, Gabriel Fernando. Hospital Alemán; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Angerosa, Margarita. Hospital Alemán; Argentin