Systematic Differential Renormalization to All Orders

We present a systematic implementation of differential renormalization to all orders in perturbation theory. The method is applied to individual Feynamn graphs written in coordinate space. After isolating every singularity. which appears in a bare diagram, we define a subtraction procedure which consists in replacing the core of the singularity by its renormalized form givenby a differential formula. The organizationof subtractions in subgraphs relies in Bogoliubov's formula, fulfilling the requirements of locality, unitarity and Lorentz invariance. Our method bypasses the use of an intermediate regularization andautomatically delivers renormalized amplitudes which obey renormalization group equations.Comment: TEX, 20 pages, UB-ECM-PF 93/4, 1 figureavailable upon reques

Una nueva especie y un nuevo registro de uredinales que parasitan a Conyza bonariensis en Colombia

A new anamorphic species of Uredinales, Aecidium convzee- colombiensis, is proposed, and another one, Caeoma cyclostoma, is recorded for the first time for Colombia. The two species parasitize Conyza bonariensis (Asteraceae).<br>Se propone una nueva especie anamórfica de Uredinales, Aecidium convzee-co-lombiensis, y se registra por primera vez en Colombia a Caeoma cyclostoma, ambas parasitas de Conyza bonariensis (Asteraceae)

Plan de sensibilización para la apropiación de la calidad dirigido al soldado profesional colombiano_ Guía de bolsillo

La Guía de bolsillo de Calidad dirigida a los soldados profesionales contribuye de manera específica al sistema de gestión de calidad del Ejército Nacional, buscando perfeccionar la base de la organización, que es el soldado profesional colombiano siendo este el principal participante de la seguridad nacional, misión principal del Ejército Colombiano_ En este artículo se explica la necesidad que tiene soldado por conocer los términos más relevantes del Sistema Gestión de Calidad SGC, que es la calidad, como se aplica, bajo que normatividad se encuentra y de esta manera minimizar los riesgos por desconocimiento_The Pocket Guide to Quality professional soldiers directed specifically contributes to the quality management system of the Army, seeking to perfect the base of the organization, which is the Colombian professional soldier being the main participant in the national security mission Colombian army chief_ This article explains soldier's need to know the most relevant terms of the QMS Quality Management System, which is quality, as applied, under what regulation is and thus minimize risks due to ignorance

The disaster of the Nazi-power in science as reflected by some leading journals and scientists in physics - A bibliometric study

The consequences of the Nazi-power for the scientific process are described qualitatively in various articles and books. However, recent progress in information systems allows a quantitative reflection. Literature databases ranging back to the beginning of the 20th century, the ISI citation indexes ranging back to 1945 now and sophisticated search systems are suitable tools for this purpose. In this study the overall break in the scientific productivity and that of selected physical journals are examined. An overview of the citation impact of some 50 leading physicists is given. The productivity before and after departure is analyzed and connected to biographical data.Comment: 8 pages, 10 figures, 1 tabl

Abouth the presence of Scartella cristata (Linnaeus, 1758) (Osteichthyes, Blenniidae) in Minorca (Balearic Islands, Western Mediterranean)

Abstract not availabl