The Pacific Alliance and the potential effects of a Trans-Pacific Economic Cooperation Agreement without the United States

This article analyzes the possible consequences of the entry into force of the Trans-Pacific Partnership Agreement (TPP) without the United States for the countries of the Pacific Alliance (PA). It develops a descriptive analysis of the evolution of trade between PA countries and TPP member countries during the period 1980-2015. Gravitational models are also estimated to empirically examine the determinants of trade flows in these countries. As a result, the paper shows that TPP may favor trade flows in PA countries, and that the withdrawal of the U.S. from TPP would not affect these trade flows.Este artículo analiza las posibles consecuencias, para los países de la Alianza del Pacífico (AP), de la entrada en vigor del Acuerdo de Asociación Transpacífico (TPP) sin Estados Unidos. Para ello, se desarrolla un análisis descriptivo de la evolución del comercio de los países de la AP con el resto de los países miembro del TPP durante el periodo 1980-2015. También se estiman modelos gravitacionales para examinar empíricamente los determinantes de los flujos comerciales de estos países. Se encuentra que el TPP puede favorecer los flujos comerciales de los países de la AP y que la salida de Estados Unidos del TPP no afectaría estos flujos comerciales

Demand for differentiated milk products : implications for price competition

We apply the Berry, Levinsohn and Pakes (1995) model to scanner data from Boston\ud supermarkets augmented with consumer characteristics data in order to analyze consumer\ud choices and price competition in a differentiated fluid milk market. Milk characteristics include\ud price, fat content, brand name and the organic and/or lactose-free nature of the product.\ud Empirical results show that consumer valuation of fat decreases with income but increases with\ud the number of children. Low-fat and specialty milks, such as organic and lactose-free milks, are\ud preferred by high-income consumers with no children. Although all milks are price elastic at the\ud individual brand level, the cross-price elasticities are quite low and negligible for specialty milks.\ud Based on calculated Lerner indexes, private label milks have the highest percent markups\ud despite their lower prices, while specialty milks have the lowest markups despite their higher\ud prices, which attests to a greater degree of market power for conventional and particularly for\ud private label milk

Morpho-kinematic analysis of the point-symmetric, bipolar planetary nebulae Hb 5 and K 3-17, a pathway to poly-polarity

The kinematics of the bipolar planetary nebulae Hb~5 and K 3-17 are investigated in detail by means of a comprehensive set of spatially resolved high spectral resolution, long-slit spectra. Both objects share particularly interesting characteristics, such as a complex filamentary, rosette-type nucleus, axial point-symmetry and very fast bipolar outflows. The kinematic information of Hb~5 is combined with {\it HST} imagery to construct a detailed 3D model of the nebula using the code SHAPE. The model shows that the large scale lobes are growing in a non-homologous way. The filamentary loops in the core are proven to actually be secondary lobes emerging from what appears to be a randomly punctured, dense, gaseous core and the material that forms the point symmetric structure flows within the lobes with a distinct kinematic pattern and its interaction with the lobes has had a shaping effect on them. Hb~5 and K~3-17 may represent a class of fast evolving planetary nebulae that will develop poly-polar characteristics once the nebular core evolves and expands.Comment: 19 pages, 8 figures. To appear in The Astrophysical Journa

On the generalised Chaplygin gas: worse than a big rip or quieter than a sudden singularity?

Although it has been believed that the models with generalised Chaplygin gas do not contain singularities, in a previous work we have studied how a big freeze could take place in some kinds of phantom generalised Chaplygin gas. In the present work, we study some types of generalised Chaplygin gas in order to show how different sorts of singularities could appears in such models, in the future or in the past. We point out that: (i) singularities may not be originated from the phantom nature of the fluid, and (ii) if initially the tension of the brane in a brane-world Chaplygin model is large enough then an infrared cut off appears in the past.Comment: 19 pages, 6 figures. Discussion expanded and references added. Version to appear in the International Journal of Modern Physics

Effect of nitrogen gas in the agglomeration and photoluminescence of Zn-ZnO nanowires after high-temperature annealing

The effect of anti-agglomeration and enhanced photoluminescence after high-temperature annealing of Zn-ZnO nanowires in nitrogen at-mosphere is reported. The Zn-ZnO nanowires were deposited by the hot filament chemical vapor deposition technique and subsequentlyannealed at 1100±C in oxygen or nitrogen atmospheres. It was found that under both annealing atmospheres, the structure of the nanowireswas completely oxidized. Morphological studies suggest that annealing under oxygen-rich atmosphere, grain growth occurs, resulting in acontinuous surface with a micrograin-shaped structure. However, it seems that nitrogen-rich annealing partially prevents complete agglom-eration and longitudinal structures composed by nanometric grains were observed. Although photoluminescence properties of the annealednanowires are improved in both annealing atmospheres, it was observed that the PL spectrum of nanowires annealed in nitrogen showed astronger UV emission than that of the oxygen annealed nanowires

Shallow Lakes of the Mexican Central Plateau: Assessing their Health Condition with Oxidative Stress Biomarkers in Sentinel Organisms

In the Mexican Central Plateau (MCP), due to their long history of geologic instability, numerous fluvial systems that were blocked formed extensive shallow lakes. Environmental conditions of this area have favored the agricultural land use and the settlement of great industrial corridors and cities. Human activities in MCP are largely sustained by intense water use that has led to a high deterioration in the water bodies of this area. We analyze the water quality of two selected shallow lakes of the MCP: Yuriria Lake and Xochimilco Lake and early warning biomarkers of native sentinel species of each lake. Both studied lakes are influenced by the input of complex mixtures of pollutants. We assess water quality index and a set of oxidative stress biomarkers in native endemic species of each lake. Results showed that the input of xenobiotics and changes in the periods of dry and rains in the shallow lakes studied provoke a stronger response in sentinel organisms because dilution effects are minimal in a small water column. Furthermore, resuspension of sediments in shallow lakes can release pollutants to the water column that could exert damage to the health condition of the aquatic biota compromising the survival of endemic sensitive species