Papers by Marco Aurelio Pérez Hernández
Plant Species Biology
In columnar cacti, a higher production of reproductive structures on branches oriented towards th... more In columnar cacti, a higher production of reproductive structures on branches oriented towards the Equator has been explained by their higher interception of photosynthetic active radiation (PAR) as well as resource availability. The goal of this study was to evaluate the effect of orientation on diverse aspects of the reproductive biology of Myrtillocactus geometrizans. Phenology was studied in north‐ and south‐facing branches. Floral cycle events, floral visitors, reproductive traits associated with sexual and attraction functions, and reproductive success were estimated from reproductive structures with contrasting orientation. Pollination experiments were conducted to evaluate the effect of orientation on mating system. Our results showed that south‐facing branches had a longer duration of the mature fruit phenophase. Moreover, flower synchrony, production of reproductive structures, and floral traits associated with the male (number of anthers and pollen grains per floral bud),...
<p>Estimates of the posterior distribution of the demographic parameters revealed by ABC an... more <p>Estimates of the posterior distribution of the demographic parameters revealed by ABC analysis for the Scenario 3: Last Interglacial expansion of <i>Cephalocereus columna-trajani</i>.</p
Ciencia - Academia Mexicana de Ciencias, 2009
Research Papers in Economics, Mar 12, 2021
Ciencia - Academia Mexicana de Ciencias, 2016
Interciencia, 2016
Since the second half of the 20 th century, bioethics has gained relevance as a field for multidi... more Since the second half of the 20 th century, bioethics has gained relevance as a field for multidisciplinary reflection about an - thropo...
La ictiofauna de Mexico destaca mundialmente por su riqueza de especies y su gran numero de endem... more La ictiofauna de Mexico destaca mundialmente por su riqueza de especies y su gran numero de endemismos. No obstante, una gran proporcion de estas, principalmente de las dulceacuicolas (169 de ca.540), se considera amenazada. Ademas, la cantidad de especies extintas y en peligro de extincion aumenta dia con dia a un ritmo acelerado. Las amenazas para su sobrevivencia son principalmente antropogenicas, a las que se suman algunas caracteristicas intrinsecas de las poblaciones de peces, como el tamano reducido y los habitats restringidos. Los usos del agua que conducen a la perturbacion o reduccion de los habitats acuaticos, destacan como la principal causa de riesgo, seguida por la introduccion de especies exoticas. En contraste, en las especies marinas, la pesca es un factor de riesgo importante. El mayor numero de extinciones y de especies amenazadas se observa en las zonas aridas del pais, e involucra principalmente a carpitas (Cyprinidae) y cachorritos (Cyprinodontidae). En Mexico ...
Hidrobiológica, 2020
Background: Currently, aquaculture produces half of the fish consumed in the world. In Mexico, th... more Background: Currently, aquaculture produces half of the fish consumed in the world. In Mexico, this activity must tend towards sustainability, favoring that the means of production and the products obtained increase their quality and quantity, diversify and reduce their environmental impact. Objective: Analyze the information regarding the use of probiotics in aquaculture and its current development perspective in Mexico. Methods: The available literature on probiotics in aquacultural processes was compiled, with emphasis on the evaluation of positive effects in production, safety, food safety and sustainability. Results: The information analyzed allows establishing that the resistance of pathogenic microorganisms to antibiotics has become a problem in this activity when it is desired to prevent or treat diseases in cultivated species. In aquaculture, probiotics have shown great benefits, such as stimulating the immune response, increasing the survival of larvae, appetite and diseas...
La Bioetica es un campo de trabajo interdisciplinario propuesto por Van R. Potter en la decada de... more La Bioetica es un campo de trabajo interdisciplinario propuesto por Van R. Potter en la decada de 1970. Se caracteriza por su orientacion hacia la supervivencia de la especie humana y su reconocimiento de la existencia de valores naturales objetivos que permiten vincularla con el discurso de la sustentabilidad. Por ello, la Bioetica se presenta como una opcion para trabajar la dimension etica de la educacion para la sustentabilidad. Los cursos de Etica, sin embargo, no son la unica opcion para transformar las actitudes y los valores de los educandos. En este articulo, se aborda la importancia de enfocarse en construir espacios de convivencia en los que puedan ponerse en practica de manera cotidiana los habitos y los valores que consideremos virtuosos, en este caso, desde la perspectiva de la bioetica y de la sustentabilidad
Revista De Biologia Tropical, 2016
A biometric anal ysis of 58 members of the Eugerres plumieri complex from three sites (Gulf of Me... more A biometric anal ysis of 58 members of the Eugerres plumieri complex from three sites (Gulf of Mexico) was perfonned to test the hypothesis that they actually represent two species. A Principal Components Analysis Ibowed the segregation of the sample into two different groups: This classification was evaluated by a Multiple Discriminant Analysis, and the groups membership was contrasted with a null model based on random grouping. A multiple regression anaIysis allowed the identification of five discriminant morphometrie variables that account for more than 95% of the total variance of PCA-axes 1 and 2. Our results support the hypothesis that there are two species of Eugerres' in Mexican waters. Finally, the status of E. brasilianus is discussed.
Revista Mexicana de Biodiversidad, 2009
NOM-059-ECOL-2001 está considerada como amenazada y está incluida en el Apéndice I de la CITES, l... more NOM-059-ECOL-2001 está considerada como amenazada y está incluida en el Apéndice I de la CITES, la información derivada de los escasos estudios ecológicos sobre esta especie revela serios riesgos de extinción de sus poblaciones. En el presente estudio se registra una evaluación del riesgo de extinción de M. pectinifera, para la que se empleó el protocolo del Método de Evaluación del Riesgo de Extinción de las Especies Silvestres en México (MER) del Anexo I de la NOM-059-ECOL-2001, el cual se basa en 4 criterios para evaluar cualitativamente el riesgo de extinción de cualquier especie silvestre en el territorio nacional. Dicha evaluación se apoya en datos de campo de 7 poblaciones e información procedente de diversas fuentes. De acuerdo con los 12 puntos obtenidos del MER, se propone que M. pectinifera se considere en la categoría de especie en peligro de extinción (P) en la NOM-059-ECOL-2001 y sea incluida de nuevo en la Lista Roja de la UICN. Finalmente se plantea una propuesta para mejorar la valoración del Criterio D del MER.
The Stata Journal: Promoting communications on statistics and Stata, 2003
Variable bandwidth kernel density estimators increase the window width at low densities and decre... more Variable bandwidth kernel density estimators increase the window width at low densities and decrease it where data concentrate. This represents an improvement over the fixed bandwidth kernel density estimators. In this article, we explore the use of one implementation of a variable kernel estimator in conjunction with several rules and procedures for bandwidth selection applied to several real datasets. The considered examples permit us to state that when working with tens or a few hundreds of data observations, least-squares cross-validation bandwidth rarely produces useful estimates; with thousands of observations, this problem can be surpassed. Optimal bandwidth and biased cross-validation (BCV), in general, oversmooth multimodal densities. The Sheather–Jones plug-in rule pro-duced bandwidths that behave slightly better in this respect. The Silverman test is considered as a very sophisticated and safe procedure to estimate the number of modes in univariate distributions; however,...
Revista Latinoamericana de Bioética, 2016
Las múltiples crisis ecológico-sociales de la actualidad necesitan que la bioética global se inte... more Las múltiples crisis ecológico-sociales de la actualidad necesitan que la bioética global se integre a la educación superior en Ciencias Biológicas y de la Salud. Partiendo de esta premisa y con miras a desarrollar estrategias educativas que fortalezcan la adquisición de actitudes bioéticas entre los alumnos de las licenciaturas de la Divi- sión de Ciencias Biológicas y de la Salud (dcbs) de la Universidad Autónoma Metropolitana, Iztapalapa (uam-I), nuestro equipo realizó dos estudios entre 2012 y 2014, con el objetivo de conocer el contenido de bioética en planes y programas de las licenciaturas de la dcbs y las actitudes de los alumnos de licenciatura, para los cuales se emplearon una metodología de análisis de coincidencias con palabras clave y un cuestionario tipo Likert. Los resultados sugieren que la bioética no se ha incluido adecuadamente en el contenido de planes y programas, ni ha jugado un papel importante en la formación de las actitudes de los estudiantes que; sin emba...
Ciencias Marinas, 2003
Tamiahua is one of the largest estuarine-lagoonal systems in the Mexican Gulf of Mexico. It has ... more Tamiahua is one of the largest estuarine-lagoonal systems in the Mexican Gulf of Mexico. It has great economic and ecological importance due to high fisheries productivity and because it serves as a nursery, feeding and reproduction area for numerous populations of fishes and crustaceans. Spatial and temporal variations of fish diversity, abundance, dominant species and community inhabitants were determined based on samples taken on a bimonthly basis from May 1994 to March 1995. A total of 83 species, 62 genera and 32 families were collected, of which 14 species, 8 genera and 3 families were recorded for the first time in this area. Based on our collections and earlier reports, 136 species are known to use this lagoon system at some stage of their life cycle. The highest diversity and abundance values occurred during the rainy season (H'n = 2.7, D = 7.1, and J' = 0.6; biomass = 59.3 g m–2, density = 5.8 ind m–2, and average weight = 10.2 g ind–1). Seasonal fluctuation of th...
PloS one, 2017
Historic demography changes of plant species adapted to New World arid environments could be cons... more Historic demography changes of plant species adapted to New World arid environments could be consistent with either the Glacial Refugium Hypothesis (GRH), which posits that populations contracted to refuges during the cold-dry glacial and expanded in warm-humid interglacial periods, or with the Interglacial Refugium Hypothesis (IRH), which suggests that populations contracted during interglacials and expanded in glacial times. These contrasting hypotheses are developed in the present study for the giant columnar cactus Cephalocereus columna-trajani in the intertropical Mexican drylands where the effects of Late Quaternary climatic changes on phylogeography of cacti remain largely unknown. In order to determine if the historic demography and phylogeographic structure of the species are consistent with either hypothesis, sequences of the chloroplast regions psbA-trnH and trnT-trnL from 110 individuals from 10 populations comprising the full distribution range of this species were anal...
Plant biology (Stuttgart, Germany), 2017
The equatorial orientation of reproductive structures is known in some columnar cacti from extrat... more The equatorial orientation of reproductive structures is known in some columnar cacti from extratropical deserts. It has been hypothesised that photosynthetically active radiation (PAR) interception is the main reason for this orientation, because of its key effect on nocturnal CO2 uptake. However, there are no studies addressing both the effect of PAR and its consequence, carbon gain, on fruit orientation. Accordingly, we tested whether PAR and carbon gain could explain the southern fruit orientation of Myrtillocactus geometrizans, an inter-tropical columnar cactus. We studied three populations of M. geometrizans in Mexico. For each population, azimuth of fruits, total daily PAR, nocturnal acid accumulation (NAA) and fruit production were measured. The relationships between rib orientation and number of fruits, as well as total daily PAR, were evaluated using periodic regressions. The effect of total daily PAR and NAA on number of fruits was assessed using generalised linear models...
Revista de biología tropical
We analyze the origin of knowledge about fish species richness in the Tuxpan-Tampamachoco estuari... more We analyze the origin of knowledge about fish species richness in the Tuxpan-Tampamachoco estuarine system, in Veracuz, México. A complete inventory of the fish species known to date for this system (N = 179) was elaborated from published lists and from sampling seagrass meadows of Tampamachoco Lagoon, which yielded 14 previously unknown species. When compared, the different lists showed a low similarity that may reflect differences in sampling methods and collecting strategies. Current data suggest that fish species richness in Mexican coastal lagoons (Gulf of Mexico) is not related with lagoon surface area, as has been suggested, but with the number of inventories available for each lagoon, being these a reflection of the sampling effort. A sampling design for the assessment of fish species richness in estuarine systems should consider: a) using the highest possible variety of sampling fishing gears, b) collecting in all microhabitat types and c) the preference of bimonthly or qua...
Vertical distribution of plankton rotifers is not random. Although the causes of this behavior ar... more Vertical distribution of plankton rotifers is not random. Although the causes of this behavior are still under debate, it has been suggested, mainly from the study of stratified environments, that abiotic parameters play an important role in determining the presence and position of a species in the water column. We compared the composition and vertical distribution of planktonic rotifers in
Uploads
Papers by Marco Aurelio Pérez Hernández