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OALib Journal期刊

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Latin American Social Medicine and the Report of the WHO Commission on Social Determinants of Health
RAFAEL GONZALEZ GUZMAN
Social Medicine , 2009,
Abstract: In October 2008 the Latin American Social Medicine Association (ALAMES) organized an international workshop entitled “The Social Determinants of Health.” Representatives of ALAMES’ seven regions participated in discussions of the various consultative papers prepared by the working groups of the WHO Commission on the Social Determinants of Health as well as the Commission’s final report. The workshop considered how ALAMES should respond to the work of the Commission. In this paper we summarize the main points outlined in the position paper prepared by the Organizing Committee1 as well as a synopsis of the main contributions made by each of the workshop’s study sections.
Relative role of life-history traits and historical factors in shaping genetic population structure of sardines (Sardina pilchardus)
Elena G Gonzalez, Rafael Zardoya
BMC Evolutionary Biology , 2007, DOI: 10.1186/1471-2148-7-197
Abstract: We investigated genetic structure of sardine among nine locations in the Atlantic Ocean and Mediterranean Sea using allelic size variation of eight specific microsatellite loci. Bayesian clustering and assignment tests, maximum likelihood estimates of migration rates, as well as classical genetic-variance-based methods (hierarchical AMOVA test and RST pairwise comparisons) supported a single evolutionary unit for sardines. These analyses only detected weak but significant genetic differentiation, which followed an isolation-by-distance pattern according to Mantel test.We suggest that the discordant genetic structuring patterns inferred based on mitochondrial and microsatellite data might indicate that the two different classes of molecular markers may be reflecting different and complementary aspects of the evolutionary history of sardine. Mitochondrial data might be reflecting past isolation of sardine populations into two distinct groupings during Pleistocene whereas microsatellite data reveal the existence of present day gene flow among populations, and a pattern of isolation by distance.Understanding the rather complex population structure and dynamics of marine pelagic fishes requires discerning the relative influence of life-history traits and historical processes in shaping present-day population patterns (e.g. [1-7]). Marine pelagic fishes exhibit great dispersal capability that enhances gene flow, as well as large effective population sizes that impose limitations to genetic drift (e.g. [8-11]). The combination of both life-history traits acts as major homogenizing force, which hampers genetic differentiation, and ultimately may lead to panmixia (e.g. [2,12,13]). In contrast, other life-history traits such as phylopatric behavior or local larval retention and recruitment act promoting isolation by distance, and local adaptations that eventually render low but significant levels of genetic differentiation in marine pelagic fish populations (e.g. [2,10,14]).
Macroscopic degeneracy of zero-mode rotating surface states in 3D Dirac and Weyl semimetals under radiation
Jose Gonzalez,Rafael A. Molina
Physics , 2015,
Abstract: We investigate the development of novel surface states when 3D Dirac or Weyl semimetals are placed under circularly polarized electromagnetic radiation. We find that the hybridization between inverted Floquet bands opens in general a gap, which closes at so-called exceptional points found for complex values of the momentum. This corresponds to the appearance of midgap surface states in the form of evanescent waves decaying from the surface exposed to the radiation. We observe a phenomenon reminiscent of Landau quantization by which the midgap surface states get a large degeneracy proportional to the radiation flux traversing the surface of the semimetal. We show that all these surface states carry angular current, leading to an angular modulation of their charge that rotates with the same frequency of the radiation, which should manifest in the observation of a macroscopic chiral current in the irradiated surface.
Genetic structuring and migration patterns of Atlantic bigeye tuna, Thunnus obesus (Lowe, 1839)
Elena G Gonzalez, Peter Beerli, Rafael Zardoya
BMC Evolutionary Biology , 2008, DOI: 10.1186/1471-2148-8-252
Abstract: We examined allele size variation of nine microsatellite loci in 380 individuals from the Gulf of Guinea, Canary, Azores, Canada, Indian Ocean, and Pacific Ocean. To investigate temporal stability of genetic structure, three Atlantic Ocean sites were re-sampled a second year. Hierarchical AMOVA tests, RST pairwise comparisons, isolation by distance (Mantel) tests, Bayesian clustering analyses, and coalescence-based migration rate inferences supported unrestricted gene flow within the Atlantic Ocean at the nuclear level, and therefore interbreeding between individuals belonging to both mitochondrial clades. Moreover, departures from HWE in several loci were inferred for the samples of Guinea, and attributed to a Wahlund effect supporting the role of this region as a spawning and nursery area. Our microsatellite data supported a single worldwide panmictic unit for bigeye tunas. Despite the strong Agulhas Current, immigration rates seem to be higher from the Atlantic Ocean into the Indo-Pacific Ocean, but the actual number of individuals moving per generation is relatively low compared to the large population sizes inhabiting each ocean basin.Lack of congruence between mt and nuclear evidences, which is also found in other species, most likely reflects past events of isolation and secondary contact. Given the inferred relatively low number of immigrants per generation around the Cape of Good Hope, the proportions of the mitochondrial clades in the different oceans may keep stable, and it seems plausible that the presence of individuals belonging to the mt Clade I in the Atlantic Ocean may be due to extensive migrations that predated the last glaciation.Marine pelagic fishes show broad geographic distribution, large population sizes, and highly migratory movements that are thought to ultimately result in little genetic structuring (e.g. [1-4]). The above-mentioned biological peculiarities result in complex phylogeographic patterns (e.g. [5,6]), which do not often meet t
Internationalization Process and Technological Capability Trajectory of Igua？u
Kuramoto Gonzalez,Rafael; Kindl da Cunha,Sieglinde;
Journal of technology management & innovation , 2012, DOI: 10.4067/S0718-27242012000200010
Abstract: this article focuses on the influence of the internationalization process in the evolution of technological capability. this implication was studied in igua？u between 1967 and 2009. to achieve the proposed goal it was used the internationalization of brazilian export producer companies model, built by kraus (2006) and the model of technological capabilities in companies of emerging economies, built by figueiredo (2004). the study found that different stages of internationalization require different functions and different levels of technology. the discussion proposed by this paper found a close association between the process of internationalization and the development of technological capability in the company studied. it can be concluded that for companies of soluble coffee to conquer, reach and remain competitive in international markets it should engage efforts to build diverse organizational skills, alliances and technological capabilities.
Allograft Survival without Immunosuppression in Landrace Pigs after 90 Days  [PDF]
Rafael Valdés-Gonzalez, Arturo Mundo Acevedo, Ana L. Rodriguez-Ventura, Pedro Valencia Mayoral
Open Journal of Organ Transplant Surgery (OJOTS) , 2013, DOI: 10.4236/ojots.2013.34012
Abstract: Allotransplantation is helpful in order to maintain the life in some cases, but immunosuppression causes collateral effects. In this study, we were reporting the results of allografts in Landrace pigs, which were implanted on collagen-generator devices. After 2 weeks of implantation, the devices were carried out to assess allograft viability at 30, 60 and 90 days post implant. The implanted cells were islets of Langerhans and the aim was to prove their presence by immunohistochemistry for insulin and glucagon. The results were positive at 30, 60 and 90 days post implant. It demonstrated that the collagen-generator device permits the cell viability without using anti-rejected drugs or immunomodulating cells.
Autoimmunity in Amyotrophic Lateral Sclerosis: Past and Present
Mario Rafael Pagani,Laura Elisabeth Gonzalez,Osvaldo Daniel Uchitel
Neurology Research International , 2011, DOI: 10.1155/2011/497080
Abstract: Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease affecting particularly motor neurons for which no cure or effective treatment is available. Although the cause of ALS remains unknown, accumulative evidence suggests an autoimmune mechanism of pathogenesis. In this paper, we will summarize the current research related to autoimmunity in the sporadic form of ALS and discuss the potential underlying pathogenic mechanisms and perspectives. Presented data supports the view that humoral immune responses against motor nerve terminals can initiate a series of physiological changes leading to alteration of calcium homeostasis. In turn, loss of calcium homeostasis may induce neuronal death through apoptotic signaling pathways. Additional approaches identifying specific molecular features of this hypothesis are required, which will hopefully allow us to develop techniques of early diagnosis and effective therapies. 1. Introduction Amyotrophic lateral sclerosis is a neurodegenerative disorder characterized by a progressive death of motor neurons resulting in fatal paralysis in a few years. ALS was well described by Jean-Martin Charcot in 1869. Since that time, numerous studies have been conducted to characterize the anatomical, physiological, and molecular properties of the disorder [1–4]. A number of genes have been identified in hereditary ALS (named familial ALS), which account for 10% of the cases [5, 6]. The remaining 90% is called sporadic ALS and does not show any conventional hereditary pattern. Similar efforts have been done searching for a therapeutic strategy without success [7–13]. To date, the pathogenic mechanisms of ALS continue being unknown. In this paper, we will summarize the current evidence related to autoimmunity in the sporadic form of ALS and discuss the potential underlying pathogenic mechanisms and perspectives. 2. Pathogenesis The mechanisms of the specific neuronal death in ALS are unknown. Nevertheless, numerous observations support the involvement of certain alterations such as an increase in the intracellular Ca2+ concentration ([Ca2+]i) [14–18], excitotoxicity mediated by glutamate [19–22]; generation of free radicals [23–27], and autoimmunity. Recently, more attention has been called to protein inclusions in the cytoplasm of degenerating motoneurons [28]. One of the components of these ubiquitinated aggregates was identified as being TAR DNA-binding protein (TDP)-43 [29, 30], which was found to be mutated in some familial and sporadic ALS patients [31]. Although these potentially pathogenic mechanisms are
Fast Methods for Evaluating the Electric Field Level in 2D-Indoor Environments
David Martínez;Fernando Las Heras Andres;Rafael Gonzalez Ayestaran
PIER , 2007, DOI: 10.2528/PIER06122105
Abstract: When estimating the electric field level in an indoor environment, the usual complexity of the geometry and its large electric size make it necessary to deal with asymptotic assumptions, also known as high frequency techniques. But, even with these assumptions, the computational complexity, and the CPU-time cost, can be very high. Considering this drawback, this paper proposes the implementation of a "Neural Networks System" for fast calculations of the Electric field in 2D-indoor environments.
A Simple Numerical Method to Compute the Signal-to-Noise Ratio of a Magnetic Resonance Imaging Surface Coil
Rafael Rojas_Rodriguez;Alfredo O. Rodriguez Gonzalez
PIER M , 2009, DOI: 10.2528/PIERM09040604
Abstract: The quality of a magnetic resonance image can be reliably measured by the signal-to-noise ratio. This widely accepted parameter is a function of the magnetic field generated by the coil and the electric field produced by the sample to be imaged. A simple numerical method is proposed to calculate the coil signal-to-noise ratio of a circular-shaped coil and a spherical phantom. The phantom is composed of two-concentric sphere simulating a brain-skull model. The electromagnetic fields produced were then numerically computed by solving Maxwell's equations with the finite element method implemented in a commercial software tool. The electric and magnetic fields were used to numerically determine the signal-to-noise ratio using the quasi-static approach. The numerical results demonstrated that this simple method is able to calcualte the signal-to-noise ratio of surface coils with simple coil geometries involving a simulated phantom.
Risk factors in pediatric asthmatic patients. Cases and control studies. Factores de riesgo en el asma pediátrica: un estudio de casos y controles.
Rafael Alejandro Gómez Baute,Yaney Gonzalez Iglesias
MediSur , 2013,
Abstract: Background: Asthma constitutes the first disease among chronic diseases in children. The morbid-mortality promoted to continue being elevated in spite of the new therapies. For this reason it is a disease with high priority for investigation in pediatric ages. Method: A control and case group study was carried out. The samples was composed by 72 asthmatic children from three General Comprehensive doctor offices from Palmira health area located in Cienfuegos Province, Cuba; and a control group of 72 children apparently healthy from the same population. A questionnaire with the different risk variables was elaborated. Odds ratio technique was used to estimate the risk. Results: low weight at birth, family history of asthma, brochiolitis antecedent and the excessive usage of antibiotics in children under 1 year old were the main risks found. Conclusions: It is conclusive that the exposure to home allergen plus a genetic favorable factor, the prematurity, and brochiolitis constituted the most outstanding elements to suffer from asthma in the population studied. Fundamento: El asma constituye la primera de las enfermedades crónicas de la infancia. La morbi-mortalidad que provoca sigue siendo elevada a pesar de las nuevas terapias, por esta razón es una enfermedad de alta prioridad para la investigación en las edades pediátricas. Métodos: Se realizó un estudio de casos y controles. Para ello se tomó el total de los 72 ni os asmáticos de tres consultorios médicos del área de salud de Palmira, provincia de Cienfuegos, Cuba y un grupo control de 72 ni os aparentemente sanos de la misma población. Se elaboró un cuestionario con las diferentes variables de riesgo. Se empleó la razón de productos cruzados u odds ratio para estimar el riesgo. Resultados: Los principales riesgos encontrados fueron el bajo peso al nacer, el antecedente familiar de asma, el antecedente de bronquiolitis y el uso desmedido de antibióticos por debajo del a o de edad. Conclusiones: Se concluye que la exposición a los alérgenos caseros en conjunto con un fondo genético favorable, la prematuridad y la bronquilitis constituyen los elementos de mayor peso para enfermar de asma dentro de la población estudiada.
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