STRUCTURAL CHANGE, RENTS TRANSFERRING AND MARKET POWER IN THE INTERNATIONAL COFFEE MARKET: A TIME SERIES ANALYSIS

The breakdown of the International Coffee Agreement (an oligopoly of exporting countries) in 1990 led to increasing competition for market share. We use an econometric model to examine the effects of the agreement's dissolution. Results suggest a transfer of rents from producers to wholesalers and little impact on consumers.Industrial Organization,

Paradoxes of Public Sector Reform: The Mexican Experience (2000-2007)

During the last few years, many public sector reform efforts have taken place in Mexico. Without question, President Vicente Fox’s government (2000-2006) has been one of the most active administrative reformers in the history of our country (Pardo, 1991, 2007; Sánchez, 2006). The 2001-2006 National Program Against Corruption and for Transparency and Administrative Development (NPCT), and the Good Government Agenda (GGA) set a wide range of reform issues in the public sector agenda. These sought to change the structures, procedures and technologies of public organizations, as well as the behaviors and ethical standards of federal public servants. Besides, compared to previous modernization programs, it could be said that this six-year long reform agenda did not stay just as a collection of good wishes. On the contrary, during the last presidential term, numerous and diverse actions focused on building a more professional, honest, transparent, digitalized, and top-qualified government were implemented (Pardo, 2007). The question to be answered in the following years will be related to the adequacy and outcomes of these reform efforts

Evolving Lorentzian wormholes supported by phantom matter with constant state parameters

In this paper we study the possibility of sustaining an evolving wormhole via exotic matter made out of phantom energy. We show that this exotic source can support the existence of evolving wormhole spacetimes. Explicitly, a family of evolving Lorentzian wormholes conformally related to another family of zero-tidal force static wormhole geometries is found in Einstein gravity. Contrary to the standard wormhole approach, where first a convenient geometry is fixed and then the matter distribution is derived, we follow the conventional approach for finding solutions in theoretical cosmology. We derive an analytical evolving wormhole geometry by supposing that the radial tension (which is negative to the radial pressure) and the pressure measured in the tangential directions have barotropic equations of state with constant state parameters. At spatial infinity this evolving wormhole, supported by this anisotropic matter, is asymptotically flat, and its slices $t=$ constant are spaces of constant curvature. During its evolution the shape of the wormhole expands with constant velocity, i.e without acceleration or deceleration, since the scale factor has strictly a linear evolution.Comment: 9 pages, 2 figures, Accepted for publication in Phys. Rev.

Drift of particles in self-similar systems and its Liouvillian interpretation

We study the dynamics of classical particles in different classes of spatially extended self-similar systems, consisting of (i) a self-similar Lorentz billiard channel, (ii) a self-similar graph, and (iii) a master equation. In all three systems the particles typically drift at constant velocity and spread ballistically. These transport properties are analyzed in terms of the spectral properties of the operator evolving the probability densities. For systems (i) and (ii), we explain the drift from the properties of the Pollicott-Ruelle resonance spectrum and corresponding eigenvectorsComment: To appear in Phys. Rev.

Location, orbit and energy of a meteoroid impacting the moon during the Lunar Eclipse of January 21, 2019

During lunar eclipse of January 21, 2019 a meteoroid impacted the Moon producing a visible light flash. The impact was witnessed by casual observers offering an opportunity to study the phenomenon from multiple geographical locations. We use images and videos collected by observers in 7 countries to estimate the location, impact parameters (speed and incoming direction) and energy of the meteoroid. Using parallax, we achieve determining the impact location at lat. $-29.43^{+0.30}_{-0.21}$, lon. $-67.89^{+0.07}_{-0.09}$ and geocentric distance as 356553 km. After devising and applying a photo-metric procedure for measuring flash standard magnitudes in multiple RGB images having different exposure times, we found that the flash, had an average G-magnitude $\langle G\rangle = 6.7\pm0.3$. We use gravitational ray tracing (GRT) to estimate the orbital properties and likely radiant of the impactor. We find that the meteoroid impacted the moon with a speed of $14^{+7}_{-6}$ km/s (70% C.L.) and at a shallow angle, $\theta < 38.2$ degrees. Assuming a normal error for our estimated flash brightness, educated priors for the luminous efficiency and object density, and using the GRT-computed probability distributions of impact speed and incoming directions, we calculate posterior probability distributions for the kinetic energy (median $K_{\rm med}$ = 0.8 kton), body mass ($M_{\rm med}$ = 27 kg) and diameter ($d_{\rm med}$ = 29 cm), and crater size ($D_{\rm med}$ = 9 m). If our assumptions are correct, the crater left by the impact could be detectable by prospecting lunar probes. These results arose from a timely collaboration between professional and amateur astronomers which highlight the potential importance of citizen science in astronomy.Comment: 19 pages, 11 figures, 4 tables. Data and scripts available in https://github.com/seap-udea/MoonFlashes. Accepted for publication in MNRA

Direito Administrativo Sancionador

Divulgação dos SUMÁRIOS das obras recentemente incorporadas ao acervo da Biblioteca Ministro Oscar Saraiva do STJ. Em respeito à lei de Direitos Autorais, não disponibilizamos a obra na íntegra

Conservación y recuperación de la tortuga Carey (eretmochelys imbricata) del pacífico oriental, en el caso de El Salvador.

Las tortugas carey (Eretmochelys imbricata) fueron en una época muy abundantes en el Pacífico Oriental (PO) pero en la actualidad es una de las poblaciones de tortugas marinas más amenazadas a nivel mundial. El Salvador es el país más pequeño de Centroamérica, y posee una alta densidad poblacional lo que ha llevado a la sobreexplotación de muchos de los recursos naturales del país, incluyendo a las especies de tortugas marinas. Donde se considera que aproximadamente el 99% de todos los huevos son extraídos, para el consumo humano a nivel nacional (Hasbún y Vásquez 1992a)