Regulación del operador dominante en las telecomunicaciones en México

regulación, telecomunicaciones, operador dominante, México

Auctioning emission permits in a leader-follower setting

We analise emission permit auctions under leader-follower competition when the leader bids strategically and the follower acts as price-taker both at the auction and the secondary market. We obtain linear equilibrium bidding strategies for both firms and a unique equilibrium of the auction, which is optimal ex-post for the leader. Under specific distributional assumptions we conclude that the auction always awards less permits to the leader than the cost-effective amount. Our central result is a cautionary note on the properties of auctioning under market power. Under interior solution the auction allocation is dominated by grandfathering in terms of aggregated cost with probability one. As a policy implication, the specific design of the auction turns out to be crucial for cost-effectiveness. The chances of the auction to outperform grandfathering require that the former is capable of diluting the market power that is present in the secondary market

Decoherence induced by Smith-Purcell radiation

The interaction between charged particles and the vacuum fluctuations of the electromagnetic field induces decoherence, and therefore affects the contrast of fringes in an interference experiment. In this article we show that if a double slit experiment is performed near a conducting grating, the fringe visibility is reduced. We find that the reduction of contrast is proportional to the number of grooves in the conducting surface, and that for realistic values of the parameters it could be large enough to be observed. The effect can be understood in terms of the Smith-Purcell radiation produced by the surface currents induced in the conductor.Comment: 10 pages, 3 figures. Improved discussion on experimental perspectives. References added. Version to appear in Phys. Rev.

Ergonomic Evaluation on Skidding Tractors

Choroid plexus epithelial cells (CPECs) secrete cerebrospinal fluid (CSF). They express Na+-K+-ATPase and Na+-K+-2Cl− cotransporter 1 (NKCC1) on their apical membrane, deviating from typical basolateral membrane location in secretory epithelia. Given this peculiarity, the direction of basal net ion fluxes mediated by NKCC1 in CPECs is controversial, and cotransporter function is unclear. Determining the direction of basal NKCC1-mediated fluxes is critical to understanding the function of apical NKCC1. If NKCC1 works in the net efflux mode, it may be directly involved in CSF secretion. Conversely, if NKCC1 works in the net influx mode, it would have an absorptive function, contributing to intracellular Cl− concentration ([Cl−]i) and cell water volume (CWV) maintenance needed for CSF secretion. We resolve this long-standing debate by electron microscopy (EM), live-cell-imaging microscopy (LCIM), and intracellular Na+ and Cl− measurements in single CPECs of NKCC1+/+ and NKCC1−/− mouse. NKCC1-mediated ion and associated water fluxes are tightly linked, thus their direction is inferred by measuring CWV changes. Genetic or pharmacological NKCC1 inactivation produces CPEC shrinkage. EM of NKCC1−/− CPECs in situ shows they are shrunken, forming large dilations of their basolateral extracellular spaces, yet remaining attached by tight junctions. Normarski LCIM shows in vitro CPECs from NKCC1−/− are ~17% smaller than NKCC1+/+. CWV measurements in calcein-loaded CPECs show that bumetanide (10 μM) produces ~16% decrease in CWV in NKCC1+/+ but not in NKCC1−/− CPECs. Our findings suggest that under basal conditions apical NKCC1 is continuously active and works in the net inward flux mode maintaining [Cl−]i and CWV needed for CSF secretion

Presentation of the paper “Faat – Freelance as a Team”

[EN]This is the presentation of the paper entitled “Faat – Freelance as a Team” in the TEEM 2015 International Conference held in Porto (Portugal) in October 7-9, 2015. Agile methodologies are reliable engineering and management practices, capable of helping in the development of quality and successful software in business environments. However, most of these methodologies are centered on a development team and its internal communication. Moreover, for simplicity, a single product development is taken into account with its successive releases. There is another scenario: that of a single programmer working alone and often in much smaller projects and in several at the same time. Also in this scenario the client proximity is not as described by the agile environment ideal. In that case, the priorities and needs change, communication takes on another meaning and working mechanisms are not always comparable to that of a team. This paper introduces Faat (Freelance as a Team), a methodology specifically designed for those professionals. Integrating existing practices to the needs and possibilities of an individual programmer. However, it has been frequently considered the possible application of this methodology to small teams and/or other more general scenarios. This methodology has been tested in the web-based learning applications

Nurse-based restoration of degraded tropical forests with tussock grasses: Experimental support from the Andean cloud forest

10 páginas.-- 5 figuras.-- 1 tabla.-- 45 referencias.-- Supporting Information Additional Supporting Information may be found in the online versionof this article. Fig. S1. Performance of palm seedlings in each treatment. Fig. S2. Influence of light intensity on VPD. http://onlinelibrary.wiley.com/doi/10.1111/1365-2664.12311/suppinfo© 2014 British Ecological Society. The degradation of the Andean cloud forest raises strong biological conservation issues and threatens the sustainability of a crucial water resource. The idea that nurse-based restoration can accelerate the recovery of these forests is underexplored, despite its promise as a restoration technique. Recent conceptual models predict that facilitation among plants may be an important mechanism, but there is a lack of strong empirical support. We gathered experimental data to test this prediction and explore the relevance of using nurse-based forest restoration in these environments. A 20-month factorial experimental design in the Andean tropical cloud forest was established. We measured the survival and estimated the biomass production of transplanted seedlings of a keystone canopy forest species, Ceroxylon echinulatum (Arecaceae), in a deforested area in the presence/absence of herbivory, a potential nurse plant (the tussock grass Setaria sphacelata, Poaceae) and artificial shade. The joint effects of deforestation and herbivory led to the death of all seedlings, whereas most seedlings survived in the adjacent forest, which was used as the control. The presence of nurse plants led to significantly higher survival and growth of Ceroxylon seedlings throughout the experiment, regardless of herbivore presence. The nurse effects were explained by a reduction of the relative abiotic stress experienced by the seedlings outside the forest, that is, the consistently decreasing maximum vapour pressure deficit. Furthermore, nurse tussocks delayed and reduced the effects of herbivory by offering physical protection and a refuge for seedlings against detection by herbivores. However, the effects of herbivory and abiotic stress on facilitation were not additive. Synthesis and applications. Facilitation in degraded cloud forest can be intense as soon as the beneficiary plants are driven away from their physiological optimum (relative abiotic stress) and/or are confronted by herbivory. Using pre-established exotic tussock grasses as a nurse-based restoration technique in degraded cloud forest is a low-cost, non-detrimental (to biodiversity) option, especially in the absence of nurse trees and shrubs. The success of this method requires transplanting seedlings at the base of tussocks. Facilitation in degraded cloud forest can be intense as soon as the beneficiary plants are driven away from their physiological optimum (relative abiotic stress) and/or are confronted by herbivory. Using pre-established exotic tussock grasses as a nurse-based restoration technique in degraded cloud forest is a low-cost, non-detrimental (to biodiversity) option, especially in the absence of nurse trees and shrubs. The success of this method requires transplanting seedlings at the base of tussocks.We thank the people of the Inti-Llacta Reserve for their kind reception and J. Lincango, S. Cauvy-Fraunie, and C. Gully for their help with data collection. We are also grateful to P. Liancourt and two anonymous reviewers for extensive comments on the manuscript and to the LucidPapers team for English revision. This research was funded by the Ecuadorian government (ECOFONDO grant no. 019-ECO7-Inv1) and the project PALMS FP7-ENV-2007-I (www.fp7-palms.org).Peer Reviewe

Assigning pollution permits: are uniform auctions efficient?

We study the efficiency of the uniform auction as an allocation mechanism for emission permits among polluting firms. In our model, firms have private information about their abatement costs, which differ across firms and across units, and bidders' demands are linear. We show that there is a continuum of interior Bayesian-Nash equilibria, and only one is effcient, minimizing abatement costs. We find that the existence of many bidders is not a sufficient condition to guarantee an efficient equilibrium in the uniform auction. Additionally, bidders' types have to be uncorrelated

Assigning pollution permits: are uniform auctions efficient?

We study the efficiency of the uniform auction as an allocation mechanism for emission permits among polluting firms. In our model, firms have private information about their abatement costs, which differ across firms and across units, and bidders' demands are linear. We show that there is a continuum of interior Bayesian-Nash equilibria, and only one is effcient, minimizing abatement costs. We find that the existence of many bidders is not a sufficient condition to guarantee an efficient equilibrium in the uniform auction. Additionally, bidders' types have to be uncorrelated

Models of Idea Flows

This paper introduces several variations of the Eaton and Kortum (1999) model of technological change and characterizes their long run implications. Both exogenous and endogenous growth examples are studied.