Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

Este artículo presenta una caracterización paisajística y biológica de las áreas verdes urbanas (AVU) de la microcuenca del río Bermúdez, provincia de Heredia, Costa Rica. Esta caracterización se basa en una clasificación según criterios de uso de estos espacios verdes, donde se describen atributos paisajísticos como cantidad, tamaño promedio, área total y condición de cobertura de la tierra; y atributos biológicos como riqueza de especies, géneros y familias, porcentajes de especies exóticas y nativas por categoría de AVU. Se utilizaron datos geoespaciales en el caso del componente paisajístico, provenientes de los municipios, así como fotointerpretación y generación de cartografía propia, y, para el componente biológico, muestreos de campo y consultas a expertos, fuentes secundarias mediante una revisión exhaustiva de literatura científica y de las bases de datos en línea. Los resultados muestran que existe 8.95% (664.68 ha) del área total de la microcuenca dedicada a las AVU de conservación de la biodiversidad, de protección del recurso hídrico y de recreación, mientras que la categoría AVU privadas dedicadas a cultivos y pasturas casi cuadriplica las primeras (31.33%; 2 325.81 ha). Se identificó 1 029 especies de árboles, arbustos, hierbas, trepadora, etc., siendo los jardines y calles los que aportan más especies. La fauna de vertebrados está dominada por las aves, seguida por reptiles, anfibios y por último los mamíferos. En conclusión, las AVU del área de estudio muestran diferencias paisajísticas y biológicas importantes en cuanto a cantidad, tamaño, distribución espacial, riqueza florística y faunística, y que en su conjunto forman una trama verde que aporta servicios ecosistémicos a la ciudad.

The convergence of conventional agriculture, real estate investments and sand and gravel mining characterize Calimaya as one of the most negatively impacted municipalities of the Mexican altiplano by anthropic activities. The objective of this work was to analyse the geographical and environmental context of land use and land cover change (LULCC) processes in this Municipality. For this, the following indicators were estimated: the cover change rate proposed by Food and Agriculture Organization of the United Nations by using the land cover classes proposed by the Intergovernmental Panel on Climate Change. LULCC in the last decade (2010-2019) were: deforestation and advancement of potato crop in the Nevado de Toluca Flora and Fauna Protection Area; decrease in the process of occupation of cropland areas by settlements; and, soil degradation in abandoned mines.  

It was undertook an historical and cartographic investigation out on the limits of the border region of the Tuxtla Desert-Xiquipilas Valley, western frontier of the bishopric of Chiapa and Soconusco, in the south of New Spain, adjacent to the Captaincy General of Guatemala. The period of study begins in 1650, with the process of Composiciones de Tierras (1643) underway, and ends in 1810, at the end of the colonial period, with a territorial organization by Intendencias. From the analysis of documentary sources and cartography of the time, information was obtained and processed in a methodology designed for the orientation of geographic information systems towards history. The research allows us to analyze historically and geographically the processes of territorial appropria- tion through the use of land as strategies of demarcation and occupation in a frontier region.

Two objectives are integrated in this work. The first objective is to discuss the diffusion of values regarding social-environmental responsibility in the current public sphere and how they confer comparative advantages in obtaining differentiated income by companies. The second objective  is to apply this discussion to the Amazon by exemplifying the relationship that Natura company develops with traditional Pan-Amazon communities, as well as the notion of sustainability and how the Amazon can be a strategic region when it comes to environmental crises. The methodology used was based on scientific articles, magazine publications directly linked to the environmental balance of the companies and reports of the Natura company that were published in their website. We concluded that the way to produce market singularities is increasingly due to the combination of production and value diffusion in the public sphere, including the symbolic appropriation of the strategic Spaces of production.

The occurrence, distribution and origin of total inorganic arsenic (iAs), fluoride (F –) and other trace elements (Se, Sb, V, Cr, Mo, Re, Pb, Cu, Cd, Co y Zn) in the Independencia basin (IB) are investigated through hydrogeologic, hydrochemical and isotopic techniques. This basin, with an area of 7000 km2, is tributary to the continental Lerma-Chapala basin of central Mexico. Analyses of groundwater samples from 246 wells, in both granular and fractured aquifers, indicate high iAs (0.025–0.120 mg/L) and F – (1.5–16 mg/L) concentrations in the northeastern part of the basin, in an area of about 500 km2. Thirty three water samples from this area, where a regional drawdown cone has developed, indicate that the origin and hydrochemistry of iAs and F – are associated to high concentrations of HCO3– and Na+, mainly derived from the dissolution of sodium feldspar and other minerals present in the rhyolite-ignimbrite rocks that form the fractured aquifer, with long groundwater residence times up to 35,000 years. Dissolution of arsenic minerals is a secondary processes for iAs enrichment in groundwater, whereas F – enrichment is related to dissolution of fluorite, high concentrations of Li+ , Cl –, Cs, Br –, and thermal water. The abundance of iAs and F – does not correlate with that of heavy metalloids or oxide-forming elements, neither with other trace elements in solution. Stable isotopes, in 125 samples, indicated a meteoric origin of the groundwater, variable altitude of the recharge, and that water was unaffected by evaporation during recharge, including those with ages in the range of thousands of years of residence time in the aquifer. Besides, there are no evidence that the basin was closed throughout its geologic evolution. If criteria and policies for groundwater management are not established for the IB, the size of the areas impacted by high concentrations of iAs and F – may increase with time, which would affect the health of the inhabitants and the environmental and economic sustainability of the basin.

The objective of the study was to describe a case of enzootic ataxia in a captive Cervus elaphus (red deer) associated with copper deficiency, in the state of Colima, Mexico. In July and October 2018, two female red deer aged 3 and 7 yr manifested incoordination with weakness of the hind limbs and an anatomopathological diagnosis of progressive ataxia was established. In September 2019, a 13-yr-old female showed nervous signs similar to the 2018 cases, so a blood sample was taken for serum copper measurement. The animal was euthanized for post-mortem examination and tissue samples were collected for histology, liver, kidney, forage and soil samples were also taken for copper and molybdenum measurement. The main lesions were found microscopically in spinal cord, which showed leukomalacia, demyelination, spheroid bodies and neuronal chromatolysis. The copper concentration was 2.7 in liver, 4.67 in kidney and 0.08 in serum (mg/kg DM or ppm). The Cu:Mo ratio for soil 1 was Cu 8.48; Mo 3.00; Cu:Mo 2.83:1, soil 2: Cu 9.10; Mo 3.00; Cu:Mo 3.03:1. Forage 1: Cu 6.59; Mo 7.35; Cu:Mo 0.90:1; forage 2: Cu 2.77; Mo 6.12 ± 0.61; Cu:Mo 0.45:1. Clinical signs, microscopic lesions, and low levels of Cu in serum, liver, and forage are consistent with enzootic ataxia due to primary copper deficiency. As far as known, this is the first report of enzootic ataxia in a captive red deer in Mexico.

Las pruebas serológicas son importantes para la detección de anticuerpos específicos contra agentes infecciosos. Los ELISA indirectos comerciales son costosos y, por lo general, son tan efectivos como los ELISA caseros. En el presente trabajo fue preparado un lote de antígeno crudo de Anaplasma marginale a partir de sangre infectada, y se probó contra controles oficiales de suero positivos y negativos y comparado con un lote viejo de antígeno. El nuevo lote de antígenos mostró una eficiencia similar a la del lote viejo. La sensibilidad de la prueba entre los lotes nuevo y viejo fue comparable. Tanto el lote de antígeno nuevo como el viejo se están utilizando en exceso. El nuevo lote de antígeno es lo suficientemente grande como para ejecutar miles de pruebas a un precio más asequible que el de los kits comerciales.

The objective of this work was to evaluate the microbiological load of total coliforms (TCs), Staphylococcus aureus and Salmonella spp. in milk and fresh cheeses as indicators of process practices carried out in cheese dairies of different localities in the region of Salinas, San Luis Potosí. Fifteen establishments were sampled, milk and cheese samples were obtained, and they underwent a milk composition and microbiological analysis. Sixty-five percent of the production units do not pasteurize the milk, or they use natural rennet. The highest counts in milk were 42 x 109 and 40 x 109 CFU/ml for S. aureus and TCs, respectively. For cheese, the counts were 32 x 109 and 26 x 109 CFU/g for S. aureus and TCs, respectively. In addition, the presence of Salmonella was detected in milk and cheese. The lack of hygiene in the utensils and equipment in which the cheeses are made, as well as the use of natural rennet, can be a risk to the health of the consumer.