358 research outputs found

    Nivel de adecuación del territorio para el desarrollo de especies agrícolas y forestales en el Parque Nacional Nevado de Toluca

    Get PDF
    El Parque Nacional Nevado de Toluca es una importante reserva de recursos naturales del Estado de México. En la recuperación de los ecosistemas forestales se planteó como objetivo determinar el grado de adecuación para el desarrollo de especies forestales nativas y cultivos en la zona. En este trabajo se presenta una metodología basada en la aplicación de sistemas de información geográfica (SIG) para evaluar algunos requerimientos de las especies (climáticos, fisiográficos y edáficos) y generar mapas criterios de adecuación. El análisis permitió obtener la ocupación óptima del suelo de cuatro especies forestales y dos especies agrícolas

    Dinámica de perturbación-recuperación de las zonas forestales en el Parque Nacional Nevado de Toluca

    Get PDF
    Pese a la plena conciencia sobre los graves problemas de deforestación que sufren los bosques mexicanos, existen muy pocos estudios detallados que permitan identificar, de forma precisa, las dinámicas de perturbación-recuperación a que estos ecosistemas se encuentran sujetos. El presente trabajo, plantea una metodología detallada para analizar los procesos de cambio en la cobertura vegetal y uso del suelo, del Parque Nacional Nevado de Toluca (PNNT) para el periodo 1972-2000 aplicando métodos de cartografía automatizada y procesos de reclasificación. Se estimó una tasa de deforestación de 8,4% para dicho periodo, con un cambio en más de 2,000 ha y una pérdida anual de superficie forestal cercana a 156 ha. Se estimaron además las probabilidades de transición, a fin de conocer la disminución y/o incremento en la densidad de las zonas forestales, y en consecuencia, la dinámica de perturbación-recuperación forestal. Finalmente, fue posible caracterizar los procesos de deforestación de una de las áreas naturales protegidas más emblemáticas de México

    PROCESOS DE DEFORESTACIÓN Y REDUCCIÓN DE DENSIDAD DEL ARBOLADO DEL PARQUE NACIONAL NEVADO DE TOLUCA

    Get PDF
    Históricamente las áreas naturales de alta montaña en México han sufrido de presión a sus recursos naturales provocados por diversos factores como la extracción de recursos maderables y las plagas y enfermedades. Los intentos de zonificación resultan muy generalistas y se hace imposible hacer una evaluación de las transiciones menores de 10 años, debido a que los procesos necesarios para su evaluación suponen una elevada inversión en tiempo para tener un producto detallado y funcional. Para el Parque Nacional Nevado de Toluca se elaboró un mapa de ocupación del suelo para 2009 con una imagen SPOT basado en la categorización Cetenal de uso de suelo y vegetación escala 1:50 000 para 1972 y se contrastó con la más reciente actualización para el año 2000 como referencia. Se realizó una sobreposición de los mapas de ocupación del suelo para los años 2000 y 2009 para hacer la interpretación interactiva por sectores de las transiciones en el periodo de estudio. Así se obtuvieron las áreas en donde se ha verificado deterioro en terrenos forestales. Las áreas con mayor dinámica negativa son los bosques de pino, por efectos de deforestación y de pérdida de densidad del arbolado. Se calculó una tasa general de 35 ha año-1, contra solo 3 ha año-1 de bosques recuperados. Se concluye que el área natural protegida está sujeta a intensos procesos de tala selectiva de manera ilegal o por saneamiento

    Alpha-mannosidosis caused by toxic plants in ruminants of Argentina

    Get PDF
    It is well known that several of the swainsonine-containing plant species found widespread around the world have a negative economic impact in each country. In Argentina, most of the information on the poisonous plant species that produce α-mannosidosis is published in Spanish and thus not available to most English speaking researchers interested in toxic plants. Therefore, the aim of this review is to summarize the information about swainsonine-containing plants in Argentina, which are extensively distributed throughout different ecoregions of the country. To date, five species from three genera have been shown to induce α-mannosidosis in livestock in Argentina: Ipomoea carnea subsp. fi stulosa, Ipomoea hieronymi subsp. calchaquina (Convolvulaceae), Astragalus garbancillo, Astragalus pehuenches (Fabaceae), and Sida rodrigoi (Malvaceae). These species contain the indolizidine alkaloid swainsonine, which inhibits the lysosomal enzyme α-mannosidase and consequently affects glycoprotein metabolism, resulting in partially metabolized sugars. The prolonged consumption of these poisonous plants produces progressive weight loss and clinical signs related to a nervous disorder, characterized by tremors of head and neck, abnormalities of gait, difficulty in standing, ataxia and wide-based stance. Histological lesions are mainly characterized by vacuolation of different cells, especially neurons of the central nervous system. The main animal model used to study α-mannosidosis is the guinea pig because, when experimentally poisoned, it exhibits many of the characteristics of naturally intoxicated livestock.Estación Experimental Agropecuaria BarilocheFil: Cholich, Luciana Andrea. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; ArgentinaFil: Cholich, Luciana Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Martinez, Agustin. Instituto Nacional de Tecnologia Agropecuaria (INTA). Estacion Experimental Agropecuaria Bariloche. Grupo de Sanidad Animal; ArgentinaFil: Micheloud, Juan Francisco. Universidad Católica de Salta. Facultad de Ciencias Veterinarias y Agronomía; ArgentinaFil: Micheloud, Juan Francisco. Instituto Nacional de Tecnologia Agropecuaria (INTA). Instituto de Investigación Animal del Chaco Semiárido. Área de Sanidad Animal; ArgentinaFil: Pistán, Maria Elena. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; ArgentinaFil: Garcia, Enrique Nicolas. Universidad Nacional del Nordeste. Facultad de Ciencias Veterinarias; ArgentinaFil: Robles, Carlos Alejandro. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Grupo de Sanidad Animal; ArgentinaFil: Ortega, Hugo Hector. Universidad Nacional del Litoral. Instituto de Ciencias Veterinarias del Litoral; ArgentinaFil: Ortega, Hugo Hector. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gimeno, Eduardo Juan. Universidad Nacional de la Plata. Facultad de Ciencias Veterinarias; ArgentinaFil: Gimeno, Eduardo Juan. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Epidemiology and Management of Cysticercosis and Taenia solium Taeniasis in Europe, Systematic Review 1990-2011

    Get PDF
    Background: Cysticercosis is caused by the invasion of human or pig tissues by the metacestode larval stage of Taenia solium. In Europe, the disease was endemic in the past but the autochthonous natural life cycle of the parasite is currently completed very rarely. Recently, imported cases have increased in parallel to the increased number of migrations and international travels. The lack of specific surveillance systems for cysticercosis leads to underestimation of the epidemiological and clinical impacts. Objectives: To review the available data on epidemiology and management of cysticercosis in Europe. Methods: A review of literature on human cysticercosis and T. solium taeniasis in Europe published between 1990-2011 was conducted. Results: Out of 846 cysticercosis cases described in the literature, 522 cases were autochthonous and 324 cases were imported. The majority (70.1%) of the autochthonous cases were diagnosed in Portugal from 1983 and 1994. Imported cases of which 242 (74.7%) diagnosed in migrants and 57 (17.6%) in European travellers, showed an increasing trend. Most of imported cases were acquired in Latin America (69.8% of migrants and 44.0% of travellers). The majority of imported cases were diagnosed in Spain (47.5%), France (16.7%) and Italy (8.3%). One third of neurosurgical procedures were performed because the suspected diagnosis was cerebral neoplasm. Sixty eight autochthonous and 5 imported T. solium taeniasis cases were reported. Conclusions: Cysticercosis remains a challenge for European care providers, since they are often poorly aware of this infection and have little familiarity in managing this disease. Cysticercosis should be included among mandatory reportable diseases, in order to improve the accuracy of epidemiological information. European health care providers might benefit from a transfer of knowledge from colleagues working in endemic areas and the development of shared diagnostic and therapeutic processes would have impact on the quality of the European health systems. Key words: cysticercosis, neurocysticercosis, Taenia solium, taeniasis, Europe, travellers, migrants

    Prevalence and predictors of coronary artery disease in patients with a calcium score of zero

    Get PDF
    The absence of coronary calcification is associated with an excellent prognosis. However, a calcium score of zero does not exclude the presence of coronary artery disease (CAD) or the possibility of future cardiovascular events. Our aim was to study the prevalence and predictors of coronary artery disease in patients with a calcium score of zero. Prospective registry consisted of 3,012 consecutive patients that underwent cardiac CT (dual source CT). Stable patients referred for evaluation of possible CAD that had a calcium score of zero (n = 864) were selected for this analysis. The variables that were statistically significant were included in a multivariable logistic regression model. From 864 patients with a calcium score of zero, 107 (12.4 %) had coronary plaques on the contrast CT (10.8 %, n = 93 with nonobstructive CAD and 1.6 %, n = 14 with obstructive CAD). By logistic regression analysis, the independent predictors of CAD in this population were age >55 years [odds ratio (OR) 1.63 (1.05-2.52)], hypertension [OR 1.64 (1.05-2.56)] and dyslipidemia [OR 1.54 (1.00-2.36)]. In the presence of these 3 variables, the probability of having coronary plaques was 21 %. The absence of coronary artery calcification does not exclude the presence of coron

    Diabetes as an independent predictor of high atherosclerotic burden assessed by coronary computed tomography angiography: The coronary artery disease equivalent revisited

    Get PDF
    (1) To study the prevalence and severity of coronary artery disease (CAD) in diabetic patients. (2) To provide a detailed characterization of the coronary atherosclerotic burden, including the localization, degree of stenosis and plaque composition by coronary computed tomography angiography (CCTA). Single center prospective registry including a total of 581 consecutive stable patients (April 2011-March 2012) undergoing CCTA (Dual-source CT) for the evaluation of suspected CAD without previous myocardial infarction or revascularization procedures. Different coronary plaque burden indexes and plaque type and distribution patterns were compared between patients with (n = 85) and without diabetes (n = 496). The prevalence of CAD (any plaque; 74.1 vs. 56 %; p = 0.002) and obstructive CAD (≥50 % stenosis; 31.8 vs. 10.3 %; p<0.001) were significantly higher in diabetic patients. The remaining coronary atherosclerotic burden indexes evaluated (plaque in LM-3v-2v with prox. LAD; SIS; SSS; CT-LeSc) were also significantly higher in diabetic patients. In the per segment analysis, diabetics had a higher percentage of segments with plaque in every vessel (2.6/13.1/7.5/10.5 % for diabetics vs. 1.4/7.1/3.3/4.4 % for nondiabetics for LM, LAD, LCx, RCA respectively; p<0.001 for all) and of both calcified (19.3 vs. 9.2 %, p<0.001) and noncalcified or mixed types (14.4 vs. 7.0 %; p<0.001); the ratio of proximal-to-distal relative plaque distribution (calculated as LM/proximal vs. mid/distal/branches) was lower for diabetics (0.75 vs. 1.04; p = 0.009). Diabetes was an independent predictor of CAD and was also associated with more advanced CAD, evaluated by indexes of coronary atherosclerotic burden. Diabetics had a significantly higher prevalence of plaques in every anatomical subset and for the different plaque composition. In this report, the relative geographic distribution of the plaques within each subgroup, favored a more mid-to-distal localization in the diabetic patients

    Coronary computed tomography angiography-adapted Leaman score as a tool to noninvasively quantify total coronary atherosclerotic burden

    Get PDF
    To describe a coronary computed tomography angiography (CCTA)-adapted Leaman score (CT-LeSc) as a tool to quantify total coronary atherosclerotic burden with information regarding localization, type of plaque and degree of stenosis and to identify clinical predictors of a high coronary atherosclerotic burden as assessed by the CT-LeSc. Single center prospective registry including a total of 772 consecutive patients undergoing CCTA (Dual-source CT) from April 2011 to March 2012. For the purpose of this study, 581 stable patients referred for suspected coronary artery disease (CAD) without previous myocardial infarction or revascularization procedures were included. Pre-test CAD probability was determined using both the Diamond-Forrester extended CAD consortium method (DF-CAD consortium model) and the Morise score. Cardiovascular risk was assessed with the HeartScore. The cut-off for the 3rd tercile (CT-LeSc ≥8.3) was used to define a population with a high coronary atherosclerotic burden. The median CT-LeSc in this population (n = 581, 8,136 coronary segments evaluated; mean age 57.6 ± 11.1; 55.8 % males; 14.6 % with diabetes) was 2.2 (IQR 0-6.8). In patients with CAD (n = 341), the median CT-LeSc was 5.8 (IQR 3.2-9.6). Among patients with nonobstructive CAD, most were classified in the lowest terciles (T1, 43.0 %; T2, 36.1 %), but 20.9 % were in the highest tercile (T3). The majority of the patients with obstructive CAD were classified in T3 (78.2 %), but 21.8 % had a CT-LeSc in lower terciles (T1 or T2). The independent predictors of a high CT-LeSc were: Male sex (OR 1.73; 95 % CI 1.04-2.90) diabetes (OR 2.91; 95 % CI 1.61-5.23), hypertension (OR 2.54; 95 % CI 1.40-4.63), Morise score ≥16 (OR 1.97; 95 % CI 1.06-3.67) and HeartScore ≥5 (OR 2.42; 95 % CI 1.41-4.14). We described a cardiac CT adapted Leaman score as a tool to quantify total (obstructive and nonobstructive) coronary atherosclerotic burden, reflecting the comprehensive information about localization, degree of stenosis and type of plaque provided by CCTA. Male sex, hypertension, diabetes, a HeartScore ≥5 % and a Morise score ≥16 were associated with a high coronary atherosclerotic burden, as assessed by the CT-LeSc. About one fifth of the patients with nonobstructive CAD had a CT-LeSc in the highest tercile, and this could potentially lead to a reclass

    Epidemiology and surveillance of human (neuro)cysticercosis in Europe: is enhanced surveillance required?

    Get PDF
    Objectives To report on relevant national surveillance systems of (N)CC and taeniasis (the infection with the adult tapeworm) in the European Union/European Economic Area and to assess the magnitude of (N)CC occurrence by retrieving information on cases for the period 2000–2016. Methods (N)CC cases were retrieved via national reporting systems, a systematic literature search, contact with clinicians and a search for relevant ‘International Statistical Classification of Diseases and Related Health Problems’ (ICD)‐based data. Results Mandatory notification systems for (N)CC were found in Hungary, Iceland and Poland. Ten cases were reported in Poland and none in Hungary and Iceland. Through the systematic literature review and information given by clinicians, 263 individual and 721 aggregated (N)CC cases from 19 European countries were identified. ICD‐based data were obtained from five countries. From 2000 to 2016, a total of 3489 cases (N)CC cases were coded: 832 in Italy, eight in Latvia, 357 in Portugal, 2116 in Spain and 176 in Sweden. Conclusion Despite being classified as a possible eradicable disease, (N)CC is still diagnosed across Europe, yet its true extent and impact remain unclear.info:eu-repo/semantics/publishedVersio

    is enhanced surveillance required?

    Get PDF
    OBJECTIVES: To report on relevant national surveillance systems of (N)CC and taeniasis (the infection with the adult tapeworm) in the European Union/European Economic Area, and to assess the magnitude of (N)CC occurrence by retrieving information on cases for the period 2000-2016. METHODS: (N)CC cases were retrieved via national reporting systems, a systematic literature search, contact with clinicians, and a search for relevant "International Statistical Classification of Diseases and Related Health Problems" (ICD)-based data. RESULTS: Mandatory notification systems for (N)CC were found in Hungary, Iceland and Poland. Ten cases were reported in Poland and none in Hungary and Iceland. Through the systematic literature review and information given by clinicians, 263 individual and 721 aggregated (N)CC cases from 19 European countries were identified. ICD-based data were obtained from five countries. From 2000 to 2016, a total of 3,489 cases (N)CC cases were coded: 832 in Italy, 8 in Latvia, 357 in Portugal, 2116 in Spain and 176 in Sweden. CONCLUSION: Despite being classified as a possible eradicable disease, (N)CC is still diagnosed across Europe, yet its true extent and impact remain unclear.publishersversionpublishe
    corecore