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

[Introducción]: El pelo bovino, subproducto del proceso de trasformación de pieles, es rico en proteína queratina. Sin embargo, es poco aprovechado y su disposición final, generalmente, es el relleno sanitario. [Objetivo]: Este trabajo promueve su reciclado, a través de su transformación a un producto alimenticio para animales, aplicando un proceso de hidrólisis hidrotérmica. [Metodología]: Para ello, el pelo fue recolectado en una tenería local, lavado, molido (<0.84 mm) e hidrolizado (130 °C/2.0 atm/90 min). Después, se caracterizó en su análisis elemental, termogravimétrico, proximal y calidad microbiológica. La presencia de metales pesados y minerales, fue determinado mediante espectrometría de emisión atómica de plasma acoplado por inducción y el perfil de aminoácidos mediante cromatografía de líquidos de alta resolución. [Resultados]: Con el proceso propuesto, dicho material quedó libre de olor desagradable y textura suave y homogénea. Su estabilidad térmica fue menor a 170 °C. Presentó un contenido elemental de nitrógeno (13.80±0.61 %), carbono (46.23±1.18 %) y azufre (2.00±0.13 %). El análisis proximal reveló las siguientes composiciones (%): proteína bruta (85.2±2.5), digestible en pepsina (71.36±2.9), ceniza (2.20±0.1), extracto etéreo (4.90±0.4), extracto libre de nitrógeno (0.17±0.01) y humedad (7.53±0.2). Algunos minerales fueron encontrados (calcio, potasio, fósforo). Metales pesados y salmonella spp no fueron detectados. Se obtuvieron aminoácidos esenciales para la nutrición animal (lisina, metionina, treonina, arginina y valina), con recuperaciones mayores al 90 %. [Conclusiones]: Con base en esta información, el pelo bovino residual puede ser reciclado, a las condiciones propuestas, para su transformación a un producto alimenticio alternativo, que provee nutrientes para animales. 

[Introducción]: La vegetación de costa arenosa ubicada en el Parque Nacional de Guanahacabibes en Cuba, ofrece diversos bienes y servicios ambientales, entre ellos la recreación. Este ecosistema forma parte de los senderos ecoturísticos comercializados en el área y ha sido dañado por inundaciones ocasionadas por eventos extremos, como el huracán Wilma en el 2005. [Objetivo]: Valorar el beneficio recreativo que ofrece la vegetación de costa arenosa y el daño causado por inundaciones costeras. [Metodología]: Se utilizó una aproximación del método costos de viaje zonal, sin equidistancia, en una muestra de los visitantes que practicaron la actividad del senderismo asociada a la vegetación de costa arenosa, en el año 2016. [Resultados]: El huracán Wilma produjo inundaciones de moderadas a fuertes que afectaron entre un 70 % a 80 % el área de vegetación de costa arenosa. El impacto negativo que provocó en el ecosistema, tiene alta importancia en la jerarquía de daños. El beneficio recreativo por observar la vegetación de costa arenosa asociada a los senderos ecoturísticos tuvo un valor aproximado de 63 996 USD, para el año 2016, a su vez el valor individual del bienestar fue 15 USD. [Conclusiones]: Se puede inferir que un huracán similar al Wilma producirá una afectación análoga en la vegetación de costa arenosa y a su vez una posible pérdida de la calidad ambiental, siendo un antecedente el procedimiento utilizado y el valor recreativo estimado para este ecosistema. 

[Introduction]: Analysis of environmental impacts in egg production show significant differences between conventional and organic systems, associated with food, energy efficiency, distribution and waste management. However, the environmental impacts of agroecological egg production systems are unknown. [Objective]: to assess the environmental impacts of agroecological egg production using a life cycle analysis. [Methodology]: The study was performed for 350 Hy Line Brow hens from agroecological farms in Cundinamarca, Colombia. The analysis covered the entire production chain of 1 kg of eggs, that is, from the cradle to the grave, following the guidelines of ISO 14040. The information was collected during one-year, contemplating food production, production, distribution, consumption, and final disposal. Quantities of materials, energy, and waste were considered to evaluate the impacts with the CML-2001 methodology subsequently. [Results]: the outcome revealed that the environmental effects of an agroecological egg were up to 30% lower than those of a conventional egg. This result is mainly due to feed, which is produced in an agroecological way in the same farm; it is also due to waste treatment, use of alternative energy, and reduction of intermediaries along the commercial chain. [Conclusions]: Although the impacts of agroecological eggs are lower, it requires greater efficiency in nitrogen management, the search of disinfectants with lower impacts on the soil, the implementation of shorter and cleaner distribution systems, and the promotion of packaging material reuse.

[Introduction]: Agricultural production systems emit greenhouse gases from the application of nitrogen to increase production. [Objective]: To quantify and compare the emission of N2O resulting from the application of different nitrogen sources (ammonium nitrate (NH4NO3), calcium nitrate (CaNO3), conventional urea (CO(NH2)2), and polymer-coated urea (RP). [Methodology]: 250 kg of nitrogen ha-1 year-1 was applied to coffee plantations located in two different producing areas of Costa Rica. Gaseous samples were collected during a whole agricultural year using the static camera technique. A completely random block design with a split-plot arrangement was implemented. [Results]: The emission pattern showed that, in Naranjo, the largest events were determined after the fertilization carried out in June; the emission in that community was higher (P<0.0005) than the one determined in San Marcos of Tarrazú. The annual emission in Naranjo was higher with ammonium nitrate, and the lowest (P<0.05) with conventional urea; while in San Marcos de Tarrazú, there were no significant differences between nitrogen sources. Soil moisture, expressed as water-filled porous space, had no significant effects on the emission because, on average, it was less than 60 %. [Conclusions]: The emission factors determined were lower than that suggested by the IPCC, and were in the range of 0.25% to 0.40% of the applied nitrogen. The importance of conducting this type of research is demonstrated to determine the GHG emission, according to the soil and climatic conditions in which the tropical agricultural activities are developed.

[Introduction]: In the dry regions of Central America, forests in cattle ranches are used as a refuge for cattle during the dry season, and there is no much information about this practice. [Objective]: to determine the frequency of this practice and how it fits in farm management. [Methodology]: We conducted semi-structured interviews with cattle ranchers in 43 farms in Liberia County, Guanacaste, Costa Rica. [Results]: Cattle farmers suffered from the loss of profitability due to droughts, fire, and cattle theft. Cattle browsing in the forest was used by 70 % of farms, mostly between March and May. No type of farm or feeding strategy was associated with forest browsing. The high variability in farm management did not provide a distinct classification of feeding strategies. We found a difference in farm structure and feed types between ranches in the plains and mountain slopes. The decision to use forests for browsing seemed to rely on a trade-off between animal welfare and ease of management. Traditional knowledge about cattle behavior in forests was variable and often limited to forest edges and pastures. [Conclusions]: This research shows that forests should be taken into consideration when analyzing cattle ranching in dry regions of Central America. We recommend a further study on feeding strategies and the impact of cattle on forest integrity to determine if agricultural policymakers should foster these low-costs alternatives.

[Introduction]:The National System of Wild Protected Areas of Paraguay (SINASIP) was created by Law 352 in 1994 to bring order to the country's protected areas. Since 1954, a total of 102 protected areas have been created. The category with the greatest quantity of protected areas is "Nature Reserve," quadruple the number of National Parks and Natural Monuments. The measurement of the success of SINASIP was initially presented in a simplistic way, based on periods of surface expansion, including the objectionable Biosphere Reserves. [Objective]: This study evaluated the SINASIP in relation to the national coverage, the management categories, and a simple analysis of implementation levels. [Methodology]: The legal bodies of creation, modification, or derogation of each protected area were analyzed. [Results]:The patterns found in relation to the increase or decrease in the surface area of the system and its causes were discussed, and strong deficiencies were found in the creation process. The decrease in terms of the system's surface area is associated with a lack of adequate management, political causes, and land claims. There is a tendency in changing areas from strict conservation categories to less restrictive categories, totaling some 420,326 hectares. The average level of implementation in terms of the five criteria does not reach 50%. There are at least 13 wild protected areas and two categories without implementation; a further five other categories have less than 30% implementation. [Conclusions]: Urgent attention and an appropriate administration are required, especially in terms of restructuring and implementing successful models with multisectoral and participatory management.

[Introduction]: “The risk society” established a useful theoretical framework to understand contemporary society’s perception and the way it addresses Mexico's environmental and political model through the city’s urban development. This situation is present in the most important cities in Latin America. [Objective]: to analyze the case of the incidence of lung diseases in the city of Guadalajara, Jalisco, Mexico, and its correlation with air pollution levels, criticizing the scope and meaning of the air pollution control policy. [Methodology]: The study area was delimited where the State Committee of Epidemiological Surveillance (SCES) of the state of Jalisco recorded the highest incidence of Acute Respiratory Infections (ARIs) in the first 26 weeks of 2018, which harm mainly to children and older adults. These infections were analyzed using the multiple regression model through data obtained from the Jalisco Atmospheric Monitoring System (JAMS), which have the concentrations of the polluters’ criteria that regulate the Mexican Normativity (NOM). [Results]: A significant correlation was obtained (p-value <0.05) for carbon monoxide (CO) = 0.007, ozone (O3) = 0.037, and particles smaller than 10 microns (PM10) = 0.003, which interfere in greater way to the ARIs. [Conclusions]: Ignoring the real possibility of public health effects of the urban population arising from the concentration of pollutants in the air constitutes a limitation of the public health and environmental policy. Based on Beck's risk society theory.

[Introduction]: Territorial planning establishes processes that improve and align land morphology in order to achieve more compact and less diffuse cities. However, urban expansion has caused changes in land use and on terrestrial ecosystems affecting periurban areas located in the rural-urban interface, as a result of the arrival of new inhabitants and the development of industrial activities. [Objective]: This article analyzes the changes in land cover and the influence of the cultural ecosystem service of scenic beauty in the Guayllabamba River basin in Ecuador. [Methodology]: For this purpose, remote sensing tools and geographic information systems were used, satellite images were digitized, and an analysis of spectral bands was performed. [Results]: The development of urban settlement considerably increased in the study area, reducing forests and semi-natural areas due to an enlarged urbanization development. Still, agricultural territories maintained their activities in the area. [Conclusions]: The research also verified the usefulness of a landscape assessment as a process for the conservation of ecosystems since it establishes the impact levels to which a landscape is exposed.

[Introduction]: One of the strategies to promote the maintenance of biodiversity at the landscape level is the establishment of structural connectivity routes between the core areas of ecological conservation. However, the design of protected areas in Cuba has lacked the establishment of connectivity networks that serve as links between those areas. [Objective]: This research proposes a theoretical design of connectivity routes between the 19 most stringent conservation protected areas of the Sierra Maestra. [Methodology]: Based on terrain slope, land cover, water network, road network, and density of population settlement, friction or resistance to displacement map is computed. [Results]: The Cost-distance model, from ArcGIS, identifies the total amount of 186 structural connectivity routes. [Conclusions]: Altitudinal connectivity routes, allowing the connection between protected areas to different altitudinal floors, include 114 routes, while longitudinal connectivity, allowing the connection between protected areas to the same altitudinal level, includes 72 routes. Route density allows the identification of 53 areas of interest for biodiversity.

[Introducción]: La principal limitante para el cultivo comercial de Swietenia macrophylla en América tropical y subtropical ha sido el efecto devastador del ataque del barrenador Hypsipyla grandella. Complementariamente, el cultivo de S. macrophylla, que utiliza material genéticamente superior, en suelos de buena calidad y con una efectiva base silvicultural para el control del barrenador, sigue siendo un deseo sin cumplir en los países tropicales. [Objetivo]: Se presentan las estimaciones de mejora genética y de los costos asociados al cultivo comercial de plantaciones clonales de S. macrophylla. [Metodología]: Para la estimación de los costos, se utilizó, como insumo base, la información registrada en campo con respecto a la mano de obra y todos los materiales requeridos en la realización de las actividades, desde el establecimiento hasta el manejo a los 4 años, en dos plantaciones clonales. Se calculó el porcentaje de superioridad en volumen total de los 5 mejores clones en relación con el promedio por ensayo. [Resultados]: Se estima que, para una densidad inicial de 1 111 árb*ha-1, el costo básico total estimado para el establecimiento y cultivo de clones superiores de S. macrophylla hasta los 4 años oscila entre US$ 3 599-3 810/ha, dependiendo, principalmente, del clima del sitio y del método de control de malezas utilizado. El costo del control del barrenador es de US $ 356.64/ha, lo que representa un 9.9 % del costo básico total. En cuanto a la mejora genética, el porcentaje de superioridad en volumen total de los 5 mejores clones en cada sitio, referido al promedio general del ensayo correspondiente varió entre el 46 % y el 93 % evidenciando el efecto positivo que tiene el uso de clones superiores. [Conclusiones]: El costo del control del barrenador no debería ser un factor limitante para que el cultivo de la S. macrophylla sea rentable. Las variables dasométricas analizadas demuestran que, a la edad de 4 años, la selección de clones cumple con las expectativas de crecimiento, lo que se evidencia con una superioridad de hasta un 93 % en el volumen total, al compararlo con el promedio general de ensayo.