Land Use Conflict: When City and Country Clash

Urban sprawl is not a new phenomenon. Metropolitan areas have been growing and expanding for the past century, pushing development into rural areas. History has shown that rural-urban conflicts are often the result. During the second half of the twentieth century, the migration to the central city has been reversed, as people pour out of cities and into the suburbs. Today, increasingly complex rural-urban land use issues have continued to generate controversy

Validation of the determination of amino acids in plasma by high-performance liquid chromatography using automated pre-column derivatization with o-phthaldialdehyde

A sensitive and reproducible fully automated method for the determination of amino acids in plasma based on reversed-phase high-performance liquid chromatography and o-phthaldialdehyde pre-column derivatization is described. A 5-μm Spherisorb ODS 2 column (125 × 3 mm I.D.) was selected for routine determination. Over 40 physiological amino acids could be determined within 49 min (injection to injection) and 48 samples could be processed unattended. The coefficients of variation for most amino acids in plasma were below 4%. We were also able to measure trace amounts of amino acids in plasma normally not detected in a routine analysis. The results obtained with the method described compared favourably with those of conventional amino acid analysis (r = 0.997) and were in excellent agreement with those of other laboratories (r = 0.999)

Prophylactic Laparoscopic Gastrectomy for Hereditary Diffuse Gastric Cancer: A Case Series in a Single Family

This study suggests that a laparoscopic approach for prophylactic total gastrectomy for carriers of CDH1 gene mutation can be performed safely and effectively

Combined Endoscopic and Laparoscopic Approach to a Gastroesophageal Tumor

Minimally invasive techniques may be used in combination to manage difficult problems in general surgery leading to shorter hospital stays and improved patient satisfaction

La Gestión Ambiental Urbana De Lima, Perú

Este artículo trata de alinear la teoría y la práctica contemporáneas de la gestión ambiental urbana para proponer soluciones a los problemas reales que enfrenta una de las principales ciudades de Latinoamérica. Dichas ciudades tienen problemáticas más inmediatas que los países desarrollados y cuentan con menos recursos para resolverlas. Este estudio analiza el contexto latinoamericano y trata de profundizar en distintas cuestiones relacionadas con temas como la reducción de la pobreza, la industria, las aguas residuales y el saneamiento, el agua, la energía, el transporte y las finanzas de Lima, Perú. Finalmente, se propone un plan a cinco años para ayudar a resolver los problemas del entorno urbano del área metropolitana de Lima, una ciudad ambientalmente compleja e importante, ubicada entre el océano Pacífico y el desierto. En dicho plan se consideran las limitaciones de recursos económicos y se propone un presupuesto proporcional a las intervenciones que se plantean. This article brings the contemporary thinking and practice of Urban Environmental Management (UEM) to the solution of real problems in a major city of a developing country in Latin America. Such cities both face more immediate problems than the developed world and have fewer resources to deal with them. The study first considers the Latin American context and then reviews issues of poverty alleviation, industry, sewage and sanitation, water, energy, transportation and finance in Lima, Peru. Finally, it proposes a 5-year plan to help solve the urban environmental problems of Metropolitan Lima, an environmentally difficult, but important Latin American metropolitan area located between the Pacific Ocean and a hilly desert, utilizing a real world database and a limited budget

Supersymmetric Vacua in Random Supergravity

We determine the spectrum of scalar masses in a supersymmetric vacuum of a general N=1 supergravity theory, with the Kahler potential and superpotential taken to be random functions of N complex scalar fields. We derive a random matrix model for the Hessian matrix and compute the eigenvalue spectrum. Tachyons consistent with the Breitenlohner-Freedman bound are generically present, and although these tachyons cannot destabilize the supersymmetric vacuum, they do influence the likelihood of the existence of an `uplift' to a metastable vacuum with positive cosmological constant. We show that the probability that a supersymmetric AdS vacuum has no tachyons is formally equivalent to the probability of a large fluctuation of the smallest eigenvalue of a certain real Wishart matrix. For normally-distributed matrix entries and any N, this probability is given exactly by P = exp(-2N^2|W|^2/m_{susy}^2), with W denoting the superpotential and m_{susy} the supersymmetric mass scale; for more general distributions of the entries, our result is accurate when N >> 1. We conclude that for |W| \gtrsim m_{susy}/N, tachyonic instabilities are ubiquitous in configurations obtained by uplifting supersymmetric vacua.Comment: 26 pages, 6 figure

The effect of object-centered instructions in Cartesian and polar coordinates on saccade vector

Express saccades (ES) are the most reflexive saccadic eye movements, with very short reaction times of 70– 110 ms. It is likely that ES have the shortest saccade reaction times (SRTs) possible given the known physiological and anatomical delays present in sensory and motor systems. Nevertheless, it has been demonstrated that a vector displacement of ES to spatially extended stimuli can be influenced by spatial cognition. Edelman, Kristjansson, and Nakayama (2007) found that when two horizontally separated visual stimuli appear at a random location, the spatial vector, but not the reaction time, of human ES is strongly influenced by an instruction to make a saccade to one side (either left or right) of a visual stimulus array. Presently, we attempt to extend these findings of cognitive effects on saccades in three ways: (a) determining whether ES could be affected by other types of spatial instructions: vertical, polar amplitude, and polar direction; (b) determining whether these spatial effects increased with practice; and (c) determining how these effects depended on SRTs. The results demonstrate that both types of Cartesian as well as polar amplitude instructions strongly affect ES vector, but only modestly affect SRTs. Polar direction instructions had sizable effects only on nonreflexive saccades where the visual stimuli could be viewed for several hundred milliseconds prior to saccade execution. Short- (trial order within a block) and longterm (experience across several sessions) practice had little effect, though the effect of instruction increased with SRT. Such findings suggest a generalized, innate ability of cognition to affect the most reflexive saccadic eye movements