TRADE LIBERALIZATION, THE EXCHANGE RATE AND JOB AND WORKER FLOWS IN BRAZIL

Over the 1990's Brazil experienced a massive trade liberalization and wide variation in the real exchange rate. At the same time, employment growth was small and in manufacturing there was a significant reduction in total manufacturing. The main goal of this article is to idntify the effects of the exchange rate and trade liberalization on job and worker flows in Brazil. Using a novel sector exchange rate measure, our results suggest that a depreciation of the exchange rate affects net employment growth by increasing job creation and hires, with no effect on job reallocation. Tariffs have no effect on job or worker flows, while import penetration decrease job growth by increasing job destruction. The results suggest that the echange rate have a very important role on job and worker flows, even after controlling for openess and sector specificities.

Fock States of Flavor Neutrinos are Unphysical

It is shown that it is possible to construct an infinity of Fock spaces of flavor neutrinos depending on arbitrary unphysical mass parameters, in agreement with the theory of Blasone and Vitiello in the version proposed by Fujii, Habe and Yabuki. However, we show that these flavor neutrino Fock spaces are clever mathematical constructs without physical relevance, because the hypothesis that neutrinos produced or detected in charged-current weak interaction processes are described by flavor neutrino Fock states implies that measurable quantities depend on the arbitrary unphysical flavor neutrino mass parameters.Comment: 11 page

The Destruction of Bars by Central Mass Concentrations

More than two thirds of disk galaxies are barred to some degree. Many today harbor massive concentrations of gas in their centers, and some are known to possess supermassive black holes (SMBHs) and their associated stellar cusps. Previous theoretical work has suggested that a bar in a galaxy could be dissolved by the formation of a mass concentration in the center, although the precise mass and degree of central concentration required is not well-established. We report an extensive study of the effects of central masses on bars in high-quality N-body simulations of galaxies. We have varied the growth rate of the central mass, its final mass and degree of concentration to examine how these factors affect the evolution of the bar. Our main conclusions are: (1) Bars are more robust than previously thought. The central mass has to be as large as several percent of the disk mass to completely destroy the bar on a short timescale. (2) For a given mass, dense objects cause the greatest reduction in bar amplitude, while significantly more diffuse objects have a lesser effect. (3) The bar amplitude always decreases as the central mass is grown, and continues to decay thereafter on a cosmological time-scale. (4) The first phase of bar-weakening is due to the destruction by the CMC of lower-energy, bar-supporting orbits, while the second phase is a consequence of secular changes to the global potential which further diminish the number of bar-supporting orbits. We provide detailed phase-space and orbit analysis to support this suggestion. Thus current masses of SMBHs are probably too small, even when dressed with a stellar cusp, to affect the bar in their host galaxies. The molecular gas concentrations found in some barred galaxies are also too diffuse to affect the amplitude of the bar significantly.Comment: AASTeX v5.0 preprint; 44 pages, including 1 table and 16 figures. To appear in ApJ. High resolution version can be found at http://www.physics.rutgers.edu/~shen/bar_destruct/paper_high_res.pd

From Ethnographical Subjects to Archaeological Objects: Pierre Loti on Easter Island (Rapa Nui)

In 1872 French sailor Pierre Loti visited the desolate Pacific island of Rapa Nui. Descriptions in his diary and drawings were published and received great public interest. Here were all the ingredients to satisfy nineteenth century ideas of the exotic: remote, tropical, cannibal inhabited, strange rituals and frenzied dancing, and in addition – the ruins of an ancient and unknown civilisation. But Loti had visited the island almost at the end of its occupation by its indigenous people. The large stone statues had not been erect for some time, even though he recorded them as being so, and its population had been decimated. So Loti’s graphic and written descriptions were embellished for his audience, a fact that is almost as interesting as the real fate of Rapa Nui.Fil: Schavelzon Chavin, Daniel Gaston. Universidad de Buenos Aires. Facultad de Arquitectura y Urbanismo. Instituto de Arte Americano e Investigaciones Estéticas ; Argentin

Short GMC lifetimes: an observational estimate with the PdBI Arcsecond Whirlpool Survey (PAWS)

We describe and execute a novel approach to observationally estimate the lifetimes of giant molecular clouds (GMCs). We focus on the cloud population between the two main spiral arms in M51 (the inter-arm region) where cloud destruction via shear and star formation feedback dominates over formation processes. By monitoring the change in GMC number densities and properties from one side of the inter-arm to the other, we estimate the lifetime as a fraction of the inter-arm travel time. We find that GMC lifetimes in M51's inter-arm are finite and short, 20 to 30 Myr. Such short lifetimes suggest that cloud evolution is influenced by environment, in which processes can disrupt GMCs after a few free-fall times. Over most of the region under investigation shear appears to regulate the lifetime. As the shear timescale increases with galactocentric radius, we expect cloud destruction to switch primarily to star formation feedback at larger radii. We identify a transition from shear- to feedback-dominated disruption through a change in the behavior of the GMC number density. The signature suggests that shear is more efficient at completely dispersing clouds, whereas feedback transforms the population, e.g. by fragmenting high mass clouds into lower mass pieces. Compared to the characteristic timescale for molecular hydrogen in M51, our short lifetimes suggest that gas can remain molecular while clouds disperse and reassemble. We propose that galaxy dynamics regulates the cycling of molecular material from diffuse to bound (and ultimately star-forming) objects, contributing to long observed molecular depletion times in normal disk galaxies. We also speculate that, in more extreme environments such as elliptical galaxies and concentrated galaxy centers, star formation can be suppressed when the shear timescale becomes so short that some clouds can not survive to collapse and form stars.Comment: 16 pages, 8 figures, accepted for publication in Ap