Geometrical effects on mobility

In this paper we analyze the effect of randomly deleting streets of a synthetic city on the statistics of displacements. Our city is constituted initially by a set of streets that form a regular tessellation of the euclidean plane. Therefore we will have three types of cities, formed by squares, triangles or hexagons. We studied the complementary cumulative distribution function for displacements (CCDF). For the whole set of streets the CCDF is a stretched exponential, and as streets are deleted this function becomes a linear function and then two clear different exponentials. This behavior is qualitatively the same for all the tessellations. Most of this functions has been reported in the literature when studying the displacements of individuals based on cell data trajectories and GPS information. However, in the light of this work, the appearance of different functions for displacements CCDF can be attributed to the connectivity of the underlying street network. It is remarkably that for some proportion of streets we got a linear function for such function, and as far as we know this behavior has not been reported nor considered. Therefore, it is advisable to analyze experimental in the light of connectivity of the street network to make correlations with the present work.Comment: 7 pages, 4 figures, 3 table

String Unification and Leptophobic Z′Z' in Flipped SU(5)

We summarize recent developments in the prediction for $\alpha_s(M_Z)$, self-consistent string unification and the dynamical determination of mass scales, and leptophobic $Z'$ gauge bosons in the context of stringy flipped SU(5). [To appear in Proceedings of Fourth International Conference on Supersymmetry (SUSY96), University of Maryland (May 1996).]Comment: 5 pages, LaTeX (uses espcrc2.sty), 5 figures (included

Aquaculture in tropical Mexican lakes and dams: achievements and perspectives

Mexico, with highly diverse physiography, geology, soils and climate, is a country with a broad mosaic of aquatic ecosystems within 320 watersheds. This paper presents a brief picture of Mexican fresh waters, the distribution of rainfall and the potential for aquaculture. The main fish species and water bodies, dams and lakes, are highlighted. The country faces problems of surface water shortage which requires better management

Stability and Security in Employment and Decent Work

This document is part of a digital collection provided by the Martin P. Catherwood Library, ILR School, Cornell University, pertaining to the effects of globalization on the workplace worldwide. Special emphasis is placed on labor rights, working conditions, labor market changes, and union organizing.FLA_2012_Rpt_Stability_Security_Decent_Work.pdf: 1885 downloads, before Oct. 1, 2020

Fair Labor Association 2006 Annual Public Report

Introduction concerns effects of globalization. Examines changes from 2005-2006 as companies are encouraged to move towards self compliance, with a concentration on corporate responsibility. Data is broken down by company

Cosmic Neutrino Background as a Ferromagnet

If cosmic background neutrinos interact very weakly with each other, through spin-spin interactions, then they may have experienced a phase transition, leading to a ferromagnetic ordering. The small magnetic field resulting from ferromagnetic ordering -- if present before galaxy formation -- could act as a primordial seed of the magnetic fields observed in several galaxies. Our findings suggest that the magnetization could occur in the right epoch, if the exchange boson of neutrino-neutrino interaction is a massless boson beyond the Standard Model, with a coupling constant of $2.2\times 10^{-13} \left(\frac{m_\nu}{10^{-4}\,\rm{eV}}\right)^2<g<2.3\times 10^{-7}$. The estimation of the magnetic seed is $2.3 \times 10^{-27}\,\rm{G}\lesssim B_{\rm CNB}\lesssim 6.8\times 10^{-10}G$.Comment: 4 pages. Accepted for publication in Physics Letters

Updating prior geologic uncertainty with GPR traveltime tomographic data

ENIGMA IT

Vanishing Str M^2 in the presence of anomalous U_A(1)

We show that the presence of an anomalous $\rm U_A(1)$ factor in the gauge group of string-derived models may have the new and important phenomenological consequence of allowing the vanishing of ${\rm Str}\,{\cal M}^2$ in the ``shifted" vacuum, that results in the process of cancelling the anomalous $\rm U_A(1)$. The feasibility of this effect seems to be enhanced by a vanishing vacuum energy, and by a ``small" value of ${\rm Str}\,{\cal M}^2$ in the original vacuum. In the class of free-fermionic models with vanishing vacuum energy that we focus on, a necessary condition for this mechanism to be effective is that ${\rm Str}\,{\cal M}^2>0$ in the original vacuum. A vanishing ${\rm Str}\,{\cal M}^2$ ameliorates the cosmological constant problem and is a necessary element in the stability of the no-scale mechanism.Comment: 7 pages, no figures, LaTe