Abstract:
what does urban segregation mean in méxico and what are its implications for this particular context? this article poses these two questions. our response is based on the hypothesis of the "co-existence of isolated worlds." in order to support and develop this hypothesis, the author analyses the relationship between the objective and symbolic dimensions of urban segregation. the analysis is based on secondary data and semi-structured interviews with young people from poor and stigmatized neighborhoods in méxico city.

Abstract:
the case is reported of a patient with renal cell carcinoma who underwent radical nephrectomy. four years later, metastases were found in the right parotid gland. surgical excision of the parotid and radical neck dissection were then performed. one year later, metastases were found in the right lung, which prompted surgical ablation of the upper lobe. one year after the nephrectomy, the patient presented with adenocarcinoma of the prostate, which required radical prostatectomy. a discussion of the case and of recent information about the combination of these neoplastic diseases is carried out (acta med colomb 2009; 35: 26-30).

Abstract:
this article explores the principal discoveries of the science of genomics, placing emphasis on those related with dna microassays and microbiological diagnosis

Abstract:
the objective of this study is to provide information and a conceptual framework that will facilitate the work of persons in charge of systematizing institutions devoted to environmental health. the notion of "environment" is examined and a definition is proposed, while a look is also taken at the place held by environmental health within the context of environmental problems and their "green" and "blue" components. a number of definitions are put forth before presenting the official definition of environmental health issued by who in sofia (1993). subsequently a list is presented of the basic areas that have been assigned to the field of environmental health by different organizations or at various meetings, with paho, who, and program 21 among them. from this a rather exhaustive list of areas and subareas is constructed, with the finding that all lists are, in reality, an asystematic grouping of three different components: determining factors (from the physical world), processes (types of interventions), and roles (series of administrative tasks) which can be conceived as a matrix and which allow for the description of individual activities by the environmental health services. certain rules of operation are proposed which make it possible, through a form of algebra, to construct expressions for describing such activities and their aggregates with some precision. thus, it becomes possible to employ a common symbolic language which can facilitate intercommunication, teaching, and research in the area of environmental health.

Abstract:
background: lyme disease is a tick-borne human disease caused by the spirochete borrelia burgdorferi. main vectors of lyme disease are ticks of the ixodes and amblyomma genera. cases with clinical manifestations of lyme disease and favorable responses to antimicrobial agents have been reported in chile, some of them with erythema migrans, the hallmark of b burgdorferi infection. aim: to detect the presence of b burgdorferi in chilean ticks. material and methods: a total of 62 ticks were recollected from wild rodents and cervidae in the southern region of chile. infected and non infected ticks of the species ixodes ricimus, were used as controls. insects were homogenised and b burgdorferi was detected using classical and nested polymerase chain reactions. results: b burgdorferi was not detected in the studied ticks. conclusions: although all the elements required for the enzootic cycle of b burgdorferi are present in chile, its direct detection in chilean ticks using the nested polymerase chain reaction assay was negative. (rev méd chile 2001; 129: 270-6).

Abstract:
We study the propagation of gravitons within 5-D supersymmetric braneworld models with a bulk scalar field. The setup considered here consists of a 5-D bulk spacetime bounded by two 4-D branes localized at the fixed points of an $S^1/Z_2$ orbifold. There is a scalar field $\phi$ in the bulk which, provided a superpotential $W(\phi)$, determines the warped geometry of the 5-D spacetime. This type of scenario is common in string theory, where the bulk scalar field $\phi$ is related to the volume of small compact extra dimensions. We show that, after the moduli are stabilized by supersymmetry breaking terms localized on the branes, the only relevant degrees of freedom in the bulk consist of a 5-D massive spectrum of gravitons. Then we analyze the gravitational interaction between massive bodies localized at the positive tension brane mediated by these bulk gravitons. It is shown that the Newtonian potential describing this interaction picks up a non-trivial contribution at short distances that depends on the shape of the superpotential $W(\phi)$. We compute this contribution for dilatonic braneworld scenarios $W(\phi) = e^{\alpha \phi}$ (where $\alpha$ is a constant) and discuss the particular case of 5-D Heterotic M-theory: It is argued that a specific footprint at micron scales could be observable in the near future.

Abstract:
From the quantum field theory point of view, matter and gauge fields are generally expected to be localised around branes or topological defects occurring in extra dimensions. Here I discuss a simple scenario where, by starting with a five dimensional SU(3) gauge theory, we end up with several 4-D parallel branes with localised "chiral" fermions and gauge fields to them. I will show that it is possible to reproduce the electroweak model confined to a single brane, allowing a simple and geometrical approach to the fermion hierarchy problem. Some nice results of this construction are: Gauge and Higgs fields are unified at the 5-D level; and new particles are predicted: a left-handed neutrino of zero hypercharge, and a massive vector field coupling together the new neutrino to other left-handed leptons.

Abstract:
In braneworld models coming from string theory one generally encounters massless scalar degrees of freedom -moduli- parameterizing the volume of small compact extra-dimensions. Here we discuss the effects of such moduli on Newton's law for a fairly general 5-D supersymmetric braneworld scenario with a bulk scalar field $\phi$. We show that the Newtonian potential describing the gravitational interaction between two bodies localized on the visible brane picks up a non-trivial contribution at short distances that depends on the shape of the superpotential $W(\phi)$ of the theory. In particular, we compute this contribution for dilatonic braneworld scenarios $W(\phi) = e^{\alpha \phi}$ (where $\alpha$ is a constant) and discuss the particular case of 5-D Heterotic M-theory.

Abstract:
En este artículo se exponen los principales descubrimientos de la nueva ciencia denominada genómica y sus principales repercusiones para el diagnóstico microbiológico, tales como la nueva tecnología de los ADN chips. This article explores the principal discoveries of the science of genomics, placing emphasis on those related with DNA microassays and microbiological diagnosis