Effect of salinity stress on the life history variables of Branchipus schaefferi Fisher, 1834 (Crustacea: Anostraca)

BACKGROUND: Freshwater anostracans inhabit ephemeral water bodies in which as the water level decreases due to evaporation the salt concentration increases. Thus, for most anostracans salinity becomes the major stress factor. RESULTS: We tested five concentrations of NaCl (0 to 8 g/l) on the life table demography of Branchipus schaefferi fed Chlorella (alga). Age-specific survivorship curves of male and female B. schaefferi showed nearly a similar pattern in that increased salt concentration resulted in decreased survivorship. The age-specific reproduction (m(x)) of females showed several peaks of cyst production at 0 and 1 g/l salinity while in treatments containing salt at 4 or 8 g/l, there were fewer peaks. Average lifespan, life expectancy at birth, gross and net reproductive rates, generation time and the rate of population increase were all significantly influenced by the salt concentration in the medium. The highest value of net reproductive rate (970 cysts/female) was in treatments containing 0 g/l of salt, while the lowest was 13 cysts/female at 8 g/l. The rate of population increase (r) varied from 0.52 to 0.32 per day depending on the salt concentration in the medium. CONCLUSION: The low survival and offspring production of B. schaefferi at higher salinity levels suggests that this species is unlikely to colonize inland saline water bodies. Therefore, the temporary ponds in which it is found, proper conservative measures must be taken to protect this species

Estimación de contagios por Covid19 en México

En este trabajo se propone una exploración de datos para la predicción del comportamiento de los contagios por la pandemia del año 2020 por el COVID-19, enfermedad causada por el Coronavirus SARS-COV2. La investigación realizada presenta una exploración los datos adquiridos por la base de datos de la OMS (Organización Mundial de la Salud) y del CEPCE (Centro Europeo para la Prevención y Control de Enfermedades). Se desarrollaron dos propuestas, la primera utiliza una función logística y la segunda una ecuación de regresión, ambas generan pronósticos con una buena aproximación. Con estas propuestas se lograron buenos resultados demostrables. Finalmente, se utilizó un modelo multicriterio que proporciona un resultado independiente de la función logística. Los resultados importantes arrojados por un algoritmo es que se estima que el mayor contagio ha sido desde el 5 de mayo durante 10 días críticos posteriores

SIMULADOR ESTADISTICO DE CONTAGIOS PARA COVID-19 USANDO 13 VARIABLES DEL SISTEMA DE SALUD (STATISTICAL SIMULATOR OF CONTAGION FOR COVID-19 USING 13 VARIABLES OF THE HEALTH SYSTEM)

Resumen La probabilidad de contagio del COVID-19, ocasionada por el SARS-CoV2 de-pende de varios factores. Por lo cual, organismos internacionales han sugerido distintas medidas de prevención de contagio como son mantener una distancia de al menos dos metros, frecuente lavado de manos y el uso de mascarilla. Por otra parte, a pesar de las medidas establecidas, el COVID-19 puede ser más agresivo con personas de edad avanzada, con padecimientos previos de enfermedades como la diabetes, hipertensión u obesidad. El objetivo de este trabajo es presentar un simulador de contagios para COVID-19 (SM-COVID19) desarrollado en Visual Basic .NET mediante escenarios probabilísticos utilizando datos abiertos de distintos organismos de México para determinar las probabilidades de contagio y del crecimiento de la curva de infectados que son reportados cada día. A partir de estos datos, usando 13 variables del sistema de salud. La propuesta de simulación se enfoca en calcular las probabilidades de contagio en tres distintos escenarios: mejor de los casos, caso promedio y peor de los casos. Estas probabilidades se ajustan a los factores de riesgo que son señalados por la Secretaría de Salud. Con los resultados alcanzados, ha sido posible expresar el crecimiento de la curva de los contagios identificados como positivos al COVID-19 y enfatizar las medias de prevención en la sociedad. Palabra(s) Clave: Contagios, SARS-CoV2, Simulador estadístico. Abstract The probability of contagion of COVID-19, occasioned by SARS-CoV2 depends on several factors. Therefore, international organisms have suggested different measures of prevention of contagion such as to maintain a distance of at least two meters, frequent hand washing, and the use of mask. On the other hand, despite of the established measures, COVID-19 can be more aggressive with elderly people, with previous conditions of diseases like diabetes, hypertension or obesity. The objective of this work is to present a contagion simulator for COVID-19 developed in Visual Basic .NET through probabilistic scenarios using open data of distinct organisms of Mexico to determine the probabilities of contagions and growth of the curve of infected people which are reported every day. From these data, the proposal of simulation focuses on calculating the probabilities of contagions in three different scenarios: best of the cases, average case and worst of the cases. These probabilities adjust to the risk factors that are indicated by the Health Secretary. With the reached results, it has been possible to express the growth of the curve of the identified contagions as positives to COVID-19 and to emphasize the prevention measures in society. Keywords: Contagions, SARS-CoV2, Simulator

Lupino (Lupinus angustifolius L.): Una alternativa de proteína

Objective: To establish the crop of lupine (Lupinus angustifolius L.) in order to determine yield, chemical composition and cost of production of the seed. Methodology: The seed was produced in the Municipality of Domingo Arenas, Puebla, Mexico (19° 09' N and 98° 26' W) at 2367 m altitude in temporal conditions (July-December 2017). The chemical composition of the seed was determined in the Animal Science Department, Chapingo Autonomous University, Texcoco, Mexico. Results: The crop of lupine was established, although the yield (1080 kg ha-1) was lower than that reported in the literature (1600 to 2800 kg ha-1).The content of crude protein of the whole and dehulled seeds was higher than 27% and 38%, respectively. The cost of production per kilogram of seed ($11.66) was higher than that previously reported ($6.00). Implications of study: The results suggest that it is feasible to grow lupine seed, and according to its crude protein content, it can be an alternative in animal or human feeding in Mexico. Findings: The results indicate that based on its crude protein content and crop yield, lupine seeds can be an alternative for animal or human feeding.Objetivo: Establecer el cultivo de lupino (Lupinus angustifolius L.) para determinar el rendimiento, la composición química y el costo de producción de la semilla. Metodología: La semilla se produjo en el Municipio de Domingo Arenas, Puebla, México (19° 09' N y 98° 26' W) a 2367 m de altitud, en condiciones de temporal (julio-diciembre de 2017). La composición química de la semilla se determinó en la Universidad Autónoma Chapingo, Texcoco, México. Resultados: Se estableció el cultivo de lupino, aunque el rendimiento (1080 kg ha-1) fue inferior al reportado en la literatura (1600 a 2800 kg ha-1). El contenido de proteína cruda de las semillas entera y descascarada fue mayor al 27% y 38%, respectivamente. El costo de producción por kilogramo de semilla ($11.66) fue mayor que el reportado previamente ($6.00). Implicaciones del estudio: Los resultados sugieren que es factible cultivar semillas de lupino y, de acuerdo con su contenido de proteína cruda, puede ser una alternativa en la alimentación animal o humana en México. Conclusión: Los resultados indican que, en función de su contenido de proteína cruda y rendimiento de cultivo, las semillas de lupino pueden ser una alternativa para la alimentación animal o humana

The global abundance of tree palms

Aim Palms are an iconic, diverse and often abundant component of tropical ecosystems that provide many ecosystem services. Being monocots, tree palms are evolutionarily, morphologically and physiologically distinct from other trees, and these differences have important consequences for ecosystem services (e.g., carbon sequestration and storage) and in terms of responses to climate change. We quantified global patterns of tree palm relative abundance to help improve understanding of tropical forests and reduce uncertainty about these ecosystems under climate change. Location Tropical and subtropical moist forests. Time period Current. Major taxa studied Palms (Arecaceae). Methods We assembled a pantropical dataset of 2,548 forest plots (covering 1,191 ha) and quantified tree palm (i.e., ≥10 cm diameter at breast height) abundance relative to co‐occurring non‐palm trees. We compared the relative abundance of tree palms across biogeographical realms and tested for associations with palaeoclimate stability, current climate, edaphic conditions and metrics of forest structure. Results On average, the relative abundance of tree palms was more than five times larger between Neotropical locations and other biogeographical realms. Tree palms were absent in most locations outside the Neotropics but present in >80% of Neotropical locations. The relative abundance of tree palms was more strongly associated with local conditions (e.g., higher mean annual precipitation, lower soil fertility, shallower water table and lower plot mean wood density) than metrics of long‐term climate stability. Life‐form diversity also influenced the patterns; palm assemblages outside the Neotropics comprise many non‐tree (e.g., climbing) palms. Finally, we show that tree palms can influence estimates of above‐ground biomass, but the magnitude and direction of the effect require additional work. Conclusions Tree palms are not only quintessentially tropical, but they are also overwhelmingly Neotropical. Future work to understand the contributions of tree palms to biomass estimates and carbon cycling will be particularly crucial in Neotropical forests

Health Risk Assessment of the Levels of BTEX in Ambient Air of One Urban Site Located in Leon, Guanajuato, Mexico during Two Climatic Seasons

Levels of BTEX (benzene, toluene, ethylbenzene, and p-xylene) were determined in ambient air of an urban site located at the center of Mexico (Leon City in Guanajuato State) during two climatic seasons of 2018 (summer and autumn). Ethylbenzene (11.86 µg m−3) and toluene (11.85 µg m−3) showed the highest median concentrations during the study period. BTEX concentrations did not show a diurnal pattern but a seasonal trend was observed for benzene and toluene at a significant level of α = 0.05. Bi-variate and multivariate analysis showed significant positive correlations (at α = 0.05) among BTEX (excepting benzene), indicating common sources for toluene, ethylbenzene, and p-xylene and a different origin for benzene. A meteorological study was also conducted in order to determine the origin of air masses that could influence the BTEX concentrations in the study site. Finally, it was found that all BTEX species presented hazard quotient values (HQs) <1, indicating that there is no risk of non-cancer during the studied period. Lifetime cancer risk due to benzene exposure for the adult and child populations studied were estimated to be 7 in 1,000,000 and 1 in 100,000, respectively

Beta Diversity in a Highly Heterogeneous Area: Disentangling Species and Taxonomic Dissimilarity for Terrestrial Vertebrates

<div><p>Quantifying differences in species composition among communities provides important information related to the distribution, conservation and management of biodiversity, especially when two components are recognized: dissimilarity due to turnover, and dissimilarity due to richness differences. The ecoregions in central Mexico, within the Mexican Transition Zone, have outstanding environmental heterogeneity and harbor huge biological richness, besides differences in the origin of the biota. Therefore, biodiversity studies in this area require the use of complementary measures to achieve appropriate information that may help in the design of conservation strategies. In this work we analyze the dissimilarity of terrestrial vertebrates, and the components of turnover and richness differences, among six ecoregions in the state of Hidalgo, central Mexico. We follow two approaches: one based on species level dissimilarity, and the second on taxonomic dissimilarity. We used databases from the project “Biodiversity in the state of Hidalgo”. Our results indicate that species dissimilarity is higher than taxonomic dissimilarity, and that turnover contributes more than richness differences, both for species and taxonomic total dissimilarity. Moreover, total dissimilarity, turnover dissimilarity and the dissimilarity due to richness differences were positively related in the four vertebrate groups. Reptiles had the highest values of dissimilarity, followed by mammals, amphibians and birds. For reptiles, birds, and mammals, species turnover was the most important component, while richness differences had a higher contribution for amphibians. The highest values of dissimilarity occurred between environmentally contrasting ecoregions (i.e., tropical and temperate forests), which suggests that environmental heterogeneity and differences in the origin of biotas are key factors driving beta diversity of terrestrial vertebrates among ecoregions in this complex area.</p></div