Preliminary Abundance Analysis of Galactic Bulge Main Sequence, Subgiant, and Giant Branch Stars Observed During Microlensing with Keck/HIRES

We present an abundance analysis of six main sequence turnoff, subgiant, and giant branch stars toward the Galactic bulge that were observed with Keck/HIRES during microlensing events. This is an early look at the first detailed chemical analysis of main sequence stars in the Galactic bulge. Lensing events allow the effective aperture of Keck to be increased beyond its current dimensions; although, some events still stretched its spectroscopic capabilities. Future large telescopes with high resolution and high throughput spectrometers will allow the study of abundances in distant stellar populations and in less evolved stars with greater ease.Comment: 8 pages including 2 figures. To appear in SPIE proceedings on Astronomical Telescopes and Instrumentation. Uses spie.cl

Sudden Stops: Determinants and Output Effects in the First Era of Globalization, 1880-1913

Using a sample of 20 emerging countries from 1880 to 1913, we study the determinants and output effects of sudden stops in capital inflows during an era of intensified globalization. We find that higher levels of original sin (hard currency debt to total debt) and large current account deficits associated with reliance on foreign capital greatly increased the likelihood of experiencing a sudden stop. Trade openness and stronger commitment to the gold standard had the opposite effect. These results are robust for many sudden stop definitions used in the literature. Finally, we use a treatment effects model to show that after controlling for endogeneity sudden stops have a strong negative association with growth in per capita output. We also show that banking, currency and debt crises that were preceded by a sudden stop have much greater negative relation with growth than in the absence of a sudden stop.

Fireballs Loading and the Blast Wave Model of Gamma Ray Bursts

A simple function for the spectral power $P(\epsilon,t) \equiv \nu L(\nu)$ is proposed to model, with 9 parameters, the spectral and temporal evolution of the observed nonthermal synchrotron power flux from GRBs in the blast wave model. Here $\epsilon = h\nu/$m$_e$c$^2$ is the observed dimensionless photon energy and $t$ is the observing time. Assumptions and an issue of lack of self-consistency are spelled out. The spectra are found to be most sensitive to the baryon loading, expressed in terms of the initial bulk Lorentz factor $\Gamma_0$, and an equipartition term $q$ which is assumed to be constant in time and independent of $\Gamma_0$. Expressions are given for the peak spectral power $P_p(t) = P(\epsilon_p,t)$ at the photon energy $\epsilon = \epsilon_p(t)$ of the spectral power peak. A general rule is that the total fireball particle kinetic energy $E_0 \sim \Pi_0 t_d$, where $t_d \propto \Gamma_0^{-8/3}$ is the deceleration time scale and $\Pi_0 \equiv P(\epsilon_p,t_d) \propto \Gamma_0^{8/3}$ is the maximum measured bolometric power output in radiation, during which it is carried primarily by photons with energy ${\cal E}_0 = \epsilon_p(t_d) \propto q\Gamma_0^4$.Comment: 26 pages, including 4 figures, uses epsf.sty, rotate.sty; submitted to ApJ; revised version with extended introduction, redrawn figures, and correction

Environmental/occupational exposure to radon and non-pulmonary neoplasm risk: A review of epidemiologic evidence

Although Radon (Rn) is a known agent for lung cancer, the link between Rn exposure and other non-pulmonary neoplasms remains unclear. The aim of this review is to investigate the role of Rn in the development of tumors other than lung cancer in both occupational and environmental exposure. Particularly, our attention has been focused on leukemia and tumors related to brain and central nervous system (CNS), skin, stomach, kidney, and breast. The epidemiologic literature has been systematically reviewed focusing on workers, general population, and pediatric population. A weak increase in leukemia risk due to Rn exposure was found, but bias and confounding factors cannot be ruled out. The results of studies conducted on stomach cancer are mixed, although with some prevalence for a positive association with Rn exposure. In the case of brain and CNS cancer and skin cancer, results are inconclusive, while no association was found for breast and kidney cancers. Overall, the available evidence does not support a conclusion that a causal association has been established between Rn exposure and the risk of other non-pulmonary neoplasms mainly due to the limited number and heterogeneity of existing studies. To confirm this result, a statistical analysis should be necessary, even if it is now not applicable for the few studies available

Internet of robotic things : converging sensing/actuating, hypoconnectivity, artificial intelligence and IoT Platforms

The Internet of Things (IoT) concept is evolving rapidly and influencing newdevelopments in various application domains, such as the Internet of MobileThings (IoMT), Autonomous Internet of Things (A-IoT), Autonomous Systemof Things (ASoT), Internet of Autonomous Things (IoAT), Internetof Things Clouds (IoT-C) and the Internet of Robotic Things (IoRT) etc.that are progressing/advancing by using IoT technology. The IoT influencerepresents new development and deployment challenges in different areassuch as seamless platform integration, context based cognitive network integration,new mobile sensor/actuator network paradigms, things identification(addressing, naming in IoT) and dynamic things discoverability and manyothers. The IoRT represents new convergence challenges and their need to be addressed, in one side the programmability and the communication ofmultiple heterogeneous mobile/autonomous/robotic things for cooperating,their coordination, configuration, exchange of information, security, safetyand protection. Developments in IoT heterogeneous parallel processing/communication and dynamic systems based on parallelism and concurrencyrequire new ideas for integrating the intelligent “devices”, collaborativerobots (COBOTS), into IoT applications. Dynamic maintainability, selfhealing,self-repair of resources, changing resource state, (re-) configurationand context based IoT systems for service implementation and integrationwith IoT network service composition are of paramount importance whennew “cognitive devices” are becoming active participants in IoT applications.This chapter aims to be an overview of the IoRT concept, technologies,architectures and applications and to provide a comprehensive coverage offuture challenges, developments and applications

Intense Electromagnetic Outbursts from Collapsing Hypermassive Neutron Stars

We study the gravitational collapse of a magnetized neutron star using a novel numerical approach able to capture both the dynamics of the star and the behavior of the surrounding plasma. In this approach, a fully general relativistic magnetohydrodynamics implementation models the collapse of the star and provides appropriate boundary conditions to a force-free model which describes the stellar exterior. We validate this strategy by comparing with known results for the rotating monopole and aligned rotator solutions and then apply it to study both rotating and non-rotating stellar collapse scenarios, and contrast the behavior with what is obtained when employing the electrovacuum approximation outside the star. The non-rotating electrovacuum collapse is shown to agree qualitatively with a Newtonian model of the electromagnetic field outside a collapsing star. We illustrate and discuss a fundamental difference between the force-free and electrovacuum solutions, involving the appearance of large zones of electric-dominated field in the vacuum case. This provides a clear demonstration of how dissipative singularities appear generically in the non-linear time-evolution of force-free fluids. In both the rotating and non-rotating cases, our simulations indicate that the collapse induces a strong electromagnetic transient. In the case of sub-millisecond rotation, the magnetic field experiences strong winding and the transient carries much more energy. This result has important implications for models of gamma-ray bursts.Comment: 28 pages, 20 figures (quality lowered to reduce sizes). Improved initial data and matching condition results in a lower, but still important, energy emission. Added appendix with a discussion on effects of transition laye

The Production of Sodium and Aluminum in Globular Cluster Red Giant Stars

We study the production of Na and Al around the hydrogen shell of two red-giant sequences of different metallicity in order to explain the abundance variations seen in globular cluster stars in a mixing scenario. Using detailed stellar models together with an extensive nuclear reaction network, we have calculated the distribution of the various isotopic abundances around the hydrogen shell at numerous points along the red-giant branch. These calculations allow for the variation in both temperature and density in the shell region as well as the timescale of the nuclear processing, as governed by the outward movement of the hydrogen shell. The reaction network uses updated rates over those of Caughlin \& Fowler (1988). We find evidence for the production of Na and Al occurring in the NeNa and MgAl cycles. In particular, Na is significantly enhanced throughout the region above the hydrogen shell. The use of the newer reaction rates causes a substantial increase in the production of $^{27}$Al above the hydrogen shell through heavy leakage from the NeNa cycle and should have an important effect on the predicted surface abundances. We also find that the nuclear processing is considerably more extensive at lower metallicities.Comment: 4 pages with 4 EPS figures embedded, accepted by ApJL March 28, 199

A comparison between the effects of over-expression of miRNA-16 and miRNA-34a on cell cycle progression of mesothelioma cell lines and on their cisplatin sensitivity

The prognosis of patients affected by malignant pleural mesothelioma (MPM) is presently poor and no therapeutic strategies have improved their survival yet. Introduction of miRNA mimics to restore their reduced or absent functionality in cancer cells is considered an important opportunity and a combination of miR's might be even more effective. In the present study, miR-16 and miR-34a were transfected, singularly and in combination, in MPM cell lines H2052 and H28, and their effects on cell proliferation and sensitivity to cisplatin are reported. Interestingly, the overexpression of both miRs, alone or combined, slows down the cell cycle progression, modulates the p53 and HMGB1 expression and increases the sensitivity of cells to cisplatin, producing a marked impairment of cell proliferation and strengthening the apoptotic effect of the drug. However, the co-overexpression of the two miRs results more effective only in the regulation of the cell cycle, but does not enhance the sensitivity of MPM cells to cisplatin. Consequently, although the potential of miR-16 and miR-34a is confirmed, we must conclude that their combination does not improve the response of MPM to chemotherapy