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In tropical deciduous forests (TDFs), plants have developed various strategies to tolerate desiccation during the dry season. One strategy is osmotic adjustment, which includes the accumulation of secondary metabolites. Annona lutescens, a species that inhabits TDFs, increases and accumulates liriodenine alkaloid in its roots during the dry season. In this study, we evaluate the possible role of this molecule as an osmolyte and in pH homeostasis. We performed growth analyses and determined liriodenine concentrations during water stress in Annona lutescens seedlings grown under controlled temperature, water, and light conditions. We also calculated their osmotic adjustment based on pressure–volume curves and performed solubility tests along a pH gradient. Osmotic adjustment was compared between control plants (irrigated) and plants subjected to 15, 25, and 35 days of water stress. Osmotic adjustment was dramatically higher in plants subjected to 35 days of water stress compared to the control. The solubility of liriodenine was 54% at pH 4.5, and when liriodenine was in contact with malic acid solutions, the pH increased slightly. The highest concentration of liriodenine was in the roots, with a significant increase from 540.855 μg g−1 after 15 days of water stress to 1239.897 μg g−1 after 35 days. Our results suggest that liriodenine plays an important role in the response to water stress as an osmolyte and in pH homeostasis.

This study was carried out in the Navachiste coastal lagoon, Mexico, surrounded by intensive agricultural and aquaculture activities that cause environmental pollution by the deposition of trace metal residues in the sediments of this coastal lagoon. The trace metals are bioaccumulated by benthic organisms such as the blue swimming warrior crab, Callinectes bellicosus, which inhabits this lagoon and is consumed by humans. Ninety-five C. bellicosus edible tissue samples were collected (April 2014–January 2015). The extraction procedure of the trace metals in edible tissue samples was carried out by acid digestion with nitric acid. Based on the Environmental Protection Agency (EPA) of the United States, two indices were used to measure health risk: the estimated daily intake (EDI) and the target hazard quotient (THQ). The hazard index (HI) was used to calculate the probability of adverse carcinogenic risk and the target hazard quotient per sample (MHI) to calculate the probability of developing a carcinogenic or non-carcinogenic risk. The analysis of variance (ANOVA) showed significant differences among trace metal concentrations (p < 0.01), but all trace metal concentrations in the edible tissues of C. bellicosus were higher than the maximum residual limits (MRLs). The highest EDI was for Zn, Fe, and Cu, showing that the consumption of these crabs might represent health risks. The THQ >1 was for Ni, Zn, Cd, and Cu, and the HI = 16 revealed the risk of C. bellicosus for high-level consumers. The MHI showed that 98% of samples presented a THQ >1, implying a high rate of bioaccumulation of trace metals by the crabs independent of the sampling site in the NAV. The presence of trace metals in the edible tissue of crabs reflects contamination by trace metals, and the indices results mean that the NAV lagoon is constantly polluted with trace metal residues by neighboring agriculture and aquaculture activities. These trace metal residues are being bioaccumulated in the edible tissues of C. bellicosus due to its feeding habits, resulting in a health risk if its consumption is high, including carcinogenic and non-carcinogenic risks.

Knowledge of the biodiversity in a geographical area is crucial for the development of conservation programs and activities. Obtaining new records, of any species, expands the basic information available for studies of biological diversity. Here we document Red-legged Honeycreeper records (Cyanerpes cyaneus), in El Mango y Jolotichan localities, municipality of San Luis Acatlan, an area located on the coastal plains, where it had not been previously registered. We observe them in the months of December and January from 2016 to 2018. Considering the months when honeycreepers are observed we infer that the species is a winter visitor. These records extend the area of distribution of the species to the south by 33 km, and to the interior of the coastal plains. It suggests that the distribution of the taxon is continuous on the slope of the Pacific, between Guerrero and Chiapas.

New species records strengthen knowledge of biodiversity and are evidence that understanding of biodiversity is still partial, especially in areas where diversity is high. It is important to continue collecting information that contributes to strengthening the knowledge of biota and the benefits derived from it. In this study we recorded the Sandwich tern (Thalasseus sandvicensis) at two locations on the coast of Guerrero. The first locality was at Carrizal de Cinta Larga, municipality of Tecpan de Galeana, on February 2010, December 2012, August and December 2013 and January 2015. The second location was in Casa de Piedra beach, municipality of Marquelia, on December 2011. The species is not included in the avifaunistic list of Guerrero. Our records confirm the presence of the species at these locations.

En este artículo analizamos la imagen de nación que construye Vicente Huidobro a lo largo de la obra ensayística Balance Patriótico y que tiene como mayor característica la enfermedad. El imaginario creado por el autor fue escrito en el primer cuarto del siglo XX y se enmarca en una época de reevaluación de la imagen de nación. El ensayo deja en evidencia la existencia de un Chile dividido entre la luz del progreso y sus implicancias negativas.

Several species of Solanum produce secondary metabolites with antimicrobial activity. In the present study, the inhibitory activity of Solanum chrysotrichum, S. erianthum, S. torvum and S. rostratum against phytopathogenic Curvularia lunata was determined. Methanol extracts from roots, stems, leaves and fruits were evaluated by the method of mycelial inhibition on agar and the minimum inhibitory concentration (MIC) was determined on a liquid medium. To increase the antimicrobial activity, the combined activity of the most active extracts for each phytopathogen was also determined (a combination of intra and interspecies extracts). The results showed that 12 of the 16 methanolic extracts of Solanum species had antifungal effects against C. lunata. The extracts of S. rostratum and S. erianthum developed the highest activity (~80% inhibition and 28.4 MIC μg . ml–1), even, equal to or greater than, the reference fungicide. The mixture of the active extracts of S. chrysotrichum and S. torvum increased their activity. Various extracts affected the macro and microscopic morphology and most of them reduced the number of conidia of the fungus. This resulted in the capacity to control the vegetative growth and reproduction of C. lunata, the causal fungus of corn leaf spot disease.

Este artículo busca reflexionar sobre algunos sujetos, miembros de la nación imaginada por Joaquín Edwards Bello, que circulan en su novela El roto (1920). Todos ellos sujetos minoritarios, invisibilizados e infames, que, sin embargo, tienen su cuota de participación en el desarrollo e impulso de la joven nación chilena. Esta gama de sujetos posee un rol activo en la conformación del proyecto futuro y en la incorporación de los saberes alternos a la pluralidad de voces, fundamento del progresismo en la línea reflexiva de José Victorino Lastarria y su llamado de unidad nacional en pos del perfeccionamiento democrático. This article seeks to reflect on some subjects, members of the nation imagined by Joaquín Edwards Bello, circulating in his novel El roto (1920). All of them minority subjects, invisible and infamous, but nevertheless have their share of participation in the development and momentum of the young Chilean nation, in shaping the future project and in the incorporation of alternative knowledge to the plurality of voices, foundation of the progressivism in the reflexive line of José Victorino Lastarria and his call for national unity in pursuit of democratic perfection.

El presente artículo tiene como propósito presentar la estimación de la huella hídrica de la ciudad de Bogotá generada en el año 2014. La huella se define, de manera simplificada, como un indicador de consumo y contaminación de agua dulce. Para ello fueron seleccionados cuatro sectores para evaluar el tipo de huella correspondiente en cada uno: doméstico, industrial, agrícola y residuos sólidos. Se siguió la metodología propuesta por Hoekstra et al. La huella hídrica total de los sectores evaluados se estimó en 9.489,58 millones de m3, donde el sector de mayor huella fue el agrícola con 4.555,14 millones de m3, seguido por los sectores doméstico, de residuos e industrial. Finalmente, es posible concluir que la huella hídrica es insostenible, y que, por lo tanto, la ciudad es vulnerable frente a la disponibilidad del recurso.

Elaboramos el listado avifaunístico de Ciudad Universitaria campus Sur de la Universidad Autónoma de Guerrero; un espacio urbano ubicado al sureste de la ciudad de Chilpancingo, Guerrero. Registramos 76 especies de aves pertenecientes a 53 géneros y 21 familias. Estacionalmente, 52 especies fueron residentes, 23 visitantes de invierno y una residente de verano. Icteridae, Tyrannidae, Parulidae y Cardinalidae fueron las familias con mayor proporción de especies. La riqueza de especies que registramos en este estudio es mayor a cualquier otra realizada en campus universitarios de México. Discutimos la importancia de llevar a cabo estudios avifaunísticos en áreas urbanas y suburbanas, y la relevancia de incluir áreas verdes en la planeación y diseño de los asentamientos humanos.

Registramos a las palomas turca (Streptopelia decaocto) y africana de collar (Streptopelia roseogrisea) en Guerrero. La primera en cinco municipios del estado, en áreas suburbanas con vegetación secundaria e introducida, donde se ha establecido y se reproduce incrementando rápidamente su población. La segunda especie la registramos en cautiverio en las ciudades de Chilapa de Álvarez y Chilpancingo. Streptopelia decaocto exhibe pautas conductuales de mayor movilidad e independencia con respecto a la presencia humana, en contraste S. roseogrisea es una especie que vive en estrecha dependencia del humano. Por la evidencia, inferimos que S. decaocto está colonizando rápidamente el estado Guerrero, mientras que S. roseogrisea es reproducida como ave de ornato.

We recorded the Blue-gray Tanager (Thraupis episcopus) on the southeastern coastal plain of the state of Guerrero, Mexico, in urban areas with cover of scattered trees of native and introduced species. The current range known for this taxon comprises lowlands of eastern Mexico, from south-central Nuevo Leon to the Yucatan peninsula, including eastern Oaxaca and the Pacific slope on the coastal plain of Chiapas. However, there are no published previous records of the species in Guerrero. Possibly T. episcopus is a species that has expanded its range in episodes of active dispersal.

Chemical studies of the plant family Annonaceae have intensified in the last several decades due to the discovery of annonaceous molecules with medicinal potential (e.g., benzylisoquinoline alkaloids and acetogenins). Approximately 500 alkaloids have been identified in 138 Annonaceae species in 43 genera. In addition, until 2004, 593 annonaceous acetogenins (ACGs) had been identified, from 51 species in 13 genera.This suggests that plants from this family allocate important resources to the biosynthesis of these compounds. Despite the diversity of these molecules, their biological roles, including their physiological and/or ecological functions, are not well understood. In this study, it was provided new data describing the variety and distribution of certain alkaloids and ACGs in annonaceous plants in distinct stages of development. The potential relationships among some of these compounds and the seasonally climatic changes occurring in the plant habitat are also discussed. These data will improve our understanding of the secondary metabolism of these pharmacologically important molecules and their expression patterns during development, which will help to determine the optimal growth conditions and harvest times for their production.

Background. Phenological descriptions of plant species are used to understand cycles of foliation, flowering and fruiting. These studies provide useful means for understanding the relationships between plants and their environment. Question. What are the the foliar and reproductive strategies of four species of Annona living in the Deciduous Forest of Chiapas, Mexico? Species studied. Annona lutescens, A. macroprophyllata, A. reticulata and A. purpurea. Study sites. Three areas of deciduous forest were studied (16°31'36'' N, 92°58'25'' W, 16°28'82'' N, 92°57'48'' W, and 16°21'47'' N, 92°58'32'' W), located between the towns of Parral and Chiapa de Corzo, Chiapas, Mexico. Method. Stages of foliation, flowering, fruiting and senescence of 20 individuals per species were documented by written and photographic records during the course of a year. Variable time periods were adapted to the extended BBCH scale. The phenology was correlated with the stages of rain and drought by Spearman’s correlations Results. Phenological characteristics distinguish A. reticulata and A. lutescens as species with a reproductive strategy (flowering and fruiting) synchronized with the dry months, in contrast to A. purpurea and A. macroprophyllata, which show a reproductive strategy associated with the rainy season. The foliation of the four species is phenologically related to the rainy season. Conclusions. The species studied could be grouped according to their leaf pattern as brevideciduous or deciduous and according to their reproductive pattern as having long-term or short-term strategies.

Registramos el mielero pata roja (Cyanerpes cyaneus) en diversas localidades de la Sierra Madre del Sur. Esta especie figura en el inventario avifaunístico de Guerrero, pero se carecía de especímenes de estas poblaciones para colección científica y no se tenían registros para la región este de la Sierra Madre del Sur en el estado. Registramos individuos juveniles, adultos y un nido, lo que sugiere que son poblaciones reproductoras nativas. La ubicación geográfica de las localidades donde obtuvimos los registros para la especie permite inferir que ésta se distribuye en una franja altitudinal que se extiende de los 680 a los 1900 msnm, entre la Planicie Costera del Pacífico y la Sierra Madre del Sur. Esta área, con cobertura de selva mediana subcaducifolia y bosque mesófilo de montaña, constituye un corredor que ofrece condiciones adecuadas para la presencia de la especie.

The water quality of water bodies in Huasteca Potosina was assessed by the National Sanitation Foundation Water Quality Index (NFS WQI) depending on nine water quality parameters include physical, chemical, and biological properties. The water quality obtained at the sampling site 50-90 in the NSF-WQI range shows the medium quality. Results revealed that the Moctezuma River in Tanquian de Escobedo has low water quality with a score of 50, the Tancuilin and Axtla Rivers have good water quality, and the Moctezuma River (Tampamolón Corona), Amajac River, Valles River, Panuco River, Patitos Lagoon, Plan de Iguala Lagoon were all located in medium water quality. This indicates that the water quality of the Huasteca Potosina is irregular, due to the presence of contaminating agents coming from fertilizers, pesticides, domestic water, and residual water from the communities adjacent to the rivers and lagoons, causing an environmental impact to the aquatic ecosystems of the place. However, this research shows the importance of making use of the water quality index in this region, this to relate the environmental impacts responsible for the contamination of surface water and interpret the experimental data of this water quality monitoring to facilitate decision making and consider frequent monitoring of the quality of water bodies in the Huasteca Potosina.