Fog interception by Ball moss (<i>Tillandsia recurvata</i>)

Interception losses are a major influence in the water yield of vegetated areas. For most storms, rain interception results in less water reaching the ground. However, fog interception can increase the overall water storage capacity of the vegetation and once the storage is exceeded, fog drip is a common hydrological input. Fog interception is disregarded in water budgets of semiarid regions, but for some plant communities, it could be a mechanism offsetting evaporation losses. <i>Tillandsia recurvata</i> is a cosmopolitan epiphyte adapted to arid habitats where fog may be an important water source. Therefore, the interception storage capacity by <i>T. recurvata</i> was measured in controlled conditions and applying simulated rain or fog. Juvenile, vegetative specimens were used to determine the potential upperbound storage capacities. The storage capacity was proportional to dry weight mass. Interception storage capacity (<i>C</i>_min) was 0.19 and 0.56 mm for rainfall and fog respectively. The coefficients obtained in the laboratory were used together with biomass measurements for <i>T. recurvata</i> in a xeric scrub to calculate the depth of water intercepted by rain. <i>T. recurvata</i> contributed 20 % to the rain interception capacity of their shrub hosts: <i>Acacia farnesiana</i> and <i>Prosopis laevigata</i> and; also potentially intercepted 4.8 % of the annual rainfall. Nocturnal stomatic opening in <i>T. recurvata</i> is not only relevant for CO₂ but for water vapor, as suggested by the higher weight change of specimens wetted with fog for 1 h at dark in comparison to those wetted during daylight (543 ± 77 vs. 325 ± 56 mg, <i>p</i> = 0.048). The storage capacity of <i>T. recurvata</i> leaf surfaces could increase the amount of water available for evaporation, but as this species colonise montane forests, the effect could be negative on water recharge, because potential storage capacity is very high, in the laboratory experiments it took up to 12 h at a rate of 0.26 l h⁻¹ to reach saturation conditions when fog was applied

Comparación de la percepción social en playas recreativas arenosas de dos bahías localizadas en el Pacífico Mexicano

En el presente trabajo se desarrollaron dos formatos de encuesta, para incorporar la percepción de los usuarios a la evaluación de la calidad de las playas (Cervantes, 2006 y Silva-Iñiguez, 2006); ambos basados en un modelo cuantitativo para revelar la percepción social de las playas localizadas en la bahía de Santiago, Manzanillo, Col (MZO) y en Acapulco, Gro (ACA). Se aplicaron un total de 790 encuestas (ACA: 390 y MZO: 400), que permitieron conocer el perfil de los usuarios, sus hábitos de recreación y sus opiniones sobre las condiciones biofísicas y de infraestructura de cada playa. En ambas playas la mayoría prefirieron asistir acompañados por sus familias; las principales actividades recreativas fueron nadar, descansar, comer y beber. En general las demandas en ambos sitios coincidieron con incrementar el número de botes de basura, la frecuencia en el servicio de recolección y limpieza, baños y regaderas. Las razones por la que los usuarios seleccionaron la playa a visitar fueron la seguridad y vigilancia, así como las características biofísicas de la misma. La incorporación de esta información a modelos y/o esquemas de evaluación y gestión de playa (a través de índices ambientales) permitió realizar la valoración integral de la playa.In this paper it was developed two survey formats, to include the perception of users on the assessment of the quality of the beaches (Cervantes, 2006 and Silva-Iñiguez, 2006), both based on a quantitative model to reveal the social perception of the beaches on Santiago Bay, Manzanillo, Col (MZO) and Acapulco, Guerrero (ACA). We did a total of 790 surveys (ACA: 390 and MZO: 400), which allowed the user profile, recreation habits and their views on the biophysical and infrastructure of each beach. In both beaches, most people, attended with their families, the main recreational activities were swimming, resting, eating and drinking. In general the demands on both sites agreed to increase the number of waste baskets, the frequency of collection service and cleaning bathrooms and showers. The reasons why the users selected to visit the beach were the safety and security, as well as the biophysical characteristics of the same. Incorporating this information to models and / or evaluation schemes and beach management (through environmental ratings) allowed the comprehensive assessment of the beach

Non-L\'evy mobility patterns of Mexican Me'Phaa peasants searching for fuelwood

We measured mobility patterns that describe walking trajectories of individual Me'Phaa peasants searching and collecting fuelwood in the forests of "La Monta\~na de Guerrero" in Mexico. These one-day excursions typically follow a mixed pattern of nearly-constant steps when individuals displace from their homes towards potential collecting sites and a mixed pattern of steps of different lengths when actually searching for fallen wood in the forest. Displacements in the searching phase seem not to be compatible with L\'evy flights described by power-laws with optimal scaling exponents. These findings however can be interpreted in the light of deterministic searching on heavily degraded landscapes where the interaction of the individuals with their scarce environment produces alternative searching strategies than the expected L\'evy flights. These results have important implications for future management and restoration of degraded forests and the improvement of the ecological services they may provide to their inhabitants.Comment: 15 pages, 4 figures. First version submitted to Human Ecology. The final publication will be available at http://www.springerlink.co

Ayotzinapa y la crisis del estado neoliberal mexicano

¿Qué pasó en Ayotzinapa? Es la pregunta que surgió el 26 de septiembre de 2014, que no encuentra una respuesta satisfactoria pese a la intervención de actores de distintas instancias, niveles y nacionalidades, y al esbozo de múltiples hipótesis sobre los enfrentamientos registrados en Iguala, Guerrero, que derivaron en la muerte de varias personas y la desaparición de 43 estudiantes de la Normal Rural “Isidro Burgos”, en una tragedia que evidenció la crisis que atraviesa el estado mexicano y que afecta a todo el país. A partir de lo acontecido en Ayotzinapa y con base en la teoría general de los campos de Pierre Bourdieu y su propuesta de análisis teórico metodológico sobre el estado, en esta obra se realiza un análisis de la práctica sistemática y generalizada de las desapariciones forzadas en México, con el fin de ofrecer otra manera de comprender el entretejido político–económico–social que hace posible este grave fenómeno, que desgarra tanto a familias como a la comunidad. La herida abierta por Ayotzinapa sangra y el objetivo último de este libro es contribuir a evitar que se cierre en tanto no se responda la interrogante de qué pasó ahí y que crímenes de lesa humanidad como este sigan aconteciendo en México.ITESO, A.C

Diálogos sobre transdisciplina: los investigadores y su objeto de estudio

A la transdisciplinariedad se le ha definido como “una feliz transgresión de las fronteras entre las disciplinas” y es en este tono en que se presenta esta obra, que recopila las experiencias y reflexiones, las discusiones y propuestas de una veintena de investigadores y académicos que hablan sobre o desde la transdisciplina acerca de los temas de su interés o especialidad. La aproximación se da desde perspectivas académicas diversas y se adereza con expresiones estéticas que van desde la poesía hasta la pintura, a través de las cuales se busca ofrecer un espacio a las rutas posibles y limitaciones connaturales de acceder a la realidad para construir conocimiento “de frontera”, “en las fronteras”. Los abordajes son fruto de la exploración, filiación, encantos y desencantos por parte de los autores con la entidad de su búsqueda, quienes buscan contestar, entre otras, las siguientes cuestiones: ¿Cómo establecer un acercamiento transdisciplinar al objeto de estudio? ¿Qué hace a un objeto de estudio transdisciplinar? ¿Cómo impacta la transdisciplinariedad la identidad del académico? Una obra concebida desde una perspectiva más pedagógica que desde la doxa académica, con el interés de aportar una lectura amena para las reflexiones en torno a la trasgresión de las fronteras disciplinarias.ITESO, A.C

Pleurotus spp: A cosmopolitan fungi of biotechnological importance

The genus Pleurotus presents a multivariate species diversity due to its ability to grow in different substrates and environments. Whether wild or cultivated, they are edible mushrooms, as they present a high nutritional value and are medicinal due to their bioactive compounds with positive health effects. The aim of this review is to highlight the importance of the genus Pleurotus, since it is a cosmopolitan mushroom, and its properties can be used in different industrial applications and be a functional alternative for our future. Due to their saprophytic nature, they produce enzymes that act on the substrate in which they grow, degrading lignocellulosic material such as wood, forest and agricultural residues, hardwoods, wood by-products, cereal straw, bagasse, etc., and thanks to this degradative capacity, their enzymes are used in a wide range of biotechnological and environmental applications. In order to increase their production and consumption not only for their nutritional qualities, but also for their nutraceutical and biotechnological qualities, ease of cultivation, low investment cost, etc., new ways are being sought to increase their performance in cultivation. Recently, research has expanded the search for alternative uses of the Pleurotus genus, which has led to an increase in its cultivation, as well as its application in different fields of biotechnology. The cultivation of Pleurotus mushrooms represents an opportunity to generate a sustainable process and incorporate the process into a circular economy, generating environmental, social and economic benefits. The use of agro-industrial substrates and the subsequent reuse of the spent substrate as compost or organic fertilizer reduces the amount of waste that ends up in landfills and minimizes methane production. This allows for a more sustainable and environmentally friendly production model. Therefore, it is necessary to develop strategies for the promotion, marketing and sustainable production of products derived from these fungi