Temporal migration rates affect the genetic structure of populations in the biennial Erysimum mediohispanicum with reproductive asynchrony

Funding was provided by projects CGL2009-07487/BOS and CGL2016-77720-P (AEI/FEDER, UE) to F.X.P., by the Impact Fellow programme from the University of Stirling to M.A. and by the Portuguese Foundation for Science and Technology (SFRH/BPD/111015/2015) to A.J.M.-P.We are grateful to Armando Caballero, Juan Pedro Martínez Camacho, Mario Vallejo-Marin, Mohammed Bakkali, Robin S. Waples, Xavier Thibert-Plante and Antonio Castilla for their comments and discussions on a previous draft of the manuscript. Esperanza Manzano, Leticia Ayllón and Rocío Gómez assisted in the laboratory. The EVOFLOR discussion group stimulated the development of this study. We thank the Sierra Nevada National Park headquarters for the permits and the support during our samplings in the field. We thank Bioportal at the University of Oslo and Residencia de Estudiantes de la Universidad de Zaragoza in Jaca for logistic support. We also thank the staff of the laboratory of molecular ecology (LEM) of the EBD-CSIC for assistance.Migration is a process with important implications for the genetic structure of populations. However, there is an aspect of migration seldom investigated in plants: migration between temporally isolated groups of individuals within the same geographic population. The genetic implications of temporal migration can be particularly relevant for semelparous organisms, which are those that reproduce only once in a lifetime after a certain period of growth. In this case, reproductive asynchrony in individuals of the same population generates demes of individuals differing in their developmental stage (non-reproductive and reproductive). These demes are connected by temporal migrants, that is, individuals that become annually asynchronous with respect to the rest of individuals of their same deme. Here, we investigated the extent of temporal migration and its effects on temporal genetic structure in the biennial plant Erysimum mediohispanicum. To this end, we conducted two independent complementary approaches. First, we empirically estimated temporal migration rates and temporal genetic structure in four populations of E. mediohispanicum during three consecutive years using nuclear microsatellites markers. Second, we developed a demographic genetic simulation model to assess genetic structure for different migration scenarios differing in temporal migration rates and their occurrence probabilities. We hypothesized that genetic structure decreased with increasing temporal migration rates due to the homogenizing effect of migration. Empirical and modelling results were consistent and indicated a U-shape relationship between genetic structure and temporal migration rates. Overall, they indicated the existence of temporal genetic structure and that such genetic structure indeed decreased with increasing temporal migration rates. However, genetic structure increased again at high temporal migration rates. The results shed light into the effects of reproductive asynchrony on important population genetic parameters. Our study contributes to unravel the complexity of some processes that may account for genetic diversity and genetic structure of natural populations.AEI/FEDER, UE CGL2009-07487/BOS CGL2016-77720-PImpact Fellow programme from the University of StirlingPortuguese Foundation for Science and Technology SFRH/BPD/111015/201

Variation of gonadal cycle of the american oyster, Crassostrea virginica (Ostreoida: Ostreidae) as a function of height in Tamiahua Lagoon, Veracruz, Mexico

El ostión americano (Crassostrea virginica) es uno de los recursos de pesca mas importantes en el Golfo de México, donde es clasificado como “recurso aprovechado al máximo”. Desde 1994 las autoridades estatales fijaron una talla mínima de extracción de 70mm de longitud de concha (tamaño adulto); esto basado en estudios aislados de poblaciones. Comparamos el ciclo gonadal de subadultos y adultos. De enero a diciembre de 2011, se colectaron 90 ostiones mensualmente en la laguna de Tamiahua, Veracruz y se clasificaron como subadultos (40-69 mm) y adultos (>70mm). Los cortes histológicos de las gónadas se clasificaron en cuatrocategorías: reposo, gametogénesis, maduración y liberación de gametos. En subadultos, la categoría de reposo tuvo dos picos (enero 22% y junio 13%) y la gametogénesis entre enero y julio (22-74%). La maduración se observó en julio, agosto y setiembre (40, 64 y 41%) y la liberación en octubre (66%) y noviembre (74%). Correspondientemente, los adultos reposaban en enero y junio (17 y 13%), y la gametogénesis entre enero y julio (56-88%), maduraban en agosto y setiembre (64 y 42%) y liberaban gametos en setiembre y octubre (54 y 70%). El ciclo gametogénico fue similar entre ostiones subadultos y adultos: la especie se reproduce con tamaños igual o inferior a 50mm y esto lo deben considerar las autoridades. The American oyster, Crassostrea virginica is one of the most important fishery resources of the Gulf of Mexico, where it has been classified as “resource exploited at maximum”. Since 1994state authorities set a minimum extraction shell length of 70 mm (adult size); this was based on population studies alone. We compare the gonadal cycle of subadults oysters with adult organisms. From January to December 2011, 90 oysters were collected monthly in Tamiahua Lagoon, Veracruz and classified as subadults (50-69mm; 75% of sample) and adults (≥70mm).Histological gonad sections were classified in four categories: rest, gametogenesis, maturation and release of gametes. In subadults, the rest stage had two peaks (January 22% and June 13%), and gametogenesis between January and July (22-74%). Maturation was observed in July, August and September (40, 64 and 41% respectively) and release in October (66%) and November (45%). Correspondingly, adults were resting in January and June (17 and 13%), and January-July gametogenesis (56-88%), matured in August and September (64 and 42%) and released gametes in September and October (54 and 70%). The gametogenic cycle was similar in subadults and adults: the species breeds from sizes equal or smaller than 50 mm and this should be considered by authorities. Rev. Biol. Trop. 62 (Suppl. 3): 201-206. Epub 2014 September 01

Comparative susceptibility of veliger larvae of four bivalve mollusks to a Vibrio alginolyticus strain

The susceptibility of 7 d old veliger larvae of the scallops Argopecten ventricosus and Nodipecten subnodosus, the penshell Atrina maura, and the Pacific oyster Crassostrea gigas to a pathogenic strain of Vibrio alginolyticus was investigated by challenging the larvae with different bacterial concentrations in a semi-static assay. The results indicate that the larvae of the two scallop species are more susceptible to the V. alginolyticus strain than those of the oyster and the penshell. Signs of the disease were similar to bacillary necrosis described in previous work. Interspecies differences in susceptibility to pathogens are discussed

Investigación cualitativa en salud: una revisión crítica de la producción bibliográfica en México Qualitative health research: a critical review of recent work in Mexico

OBJETIVO: Examinar críticamente la producción bibliográfica sobre la investigación cualitativa en salud (ICS) en México. MATERIAL Y MÉTODOS: Revisión de 128 trabajos publicados en la década del 2000 al 2009. Su búsqueda y recuperación se hizo mediante consulta de índices, buscadores y bases de datos, así como consultando a académicos. Se hizo análisis de frecuencias y de contenido. RESULTADOS: La producción en este campo se incrementa notoriamente en el periodo analizado, se difunde a nivel nacional e internacional y aparece mayoritariamente en revistas de salud pública y medicina social. Su consolidación, no obstante, dista de ser realidad dada su concentración institucional, territorial y temática, su dependencia de la teoría fundamentada, su olvido de temas sanitarios y actores importantes y su impacto marginal en el campo científico. CONCLUSIONES: La investigación cualitativa en salud logra avances en México pero enfrenta serios desafíos para consolidarse. Varias propuestas se presentan para fortalecerla.<br>OBJECTIVE: This paper critically examines recent work on qualitative health research (QHR) in Mexico. MATERIAL AND METHODS: A review was conducted of 128 articles published between 2000 and 2009. A literature search was done drawing together a verse of indexes, search engine, data bases and citations, as well as interviewing researchers. A frequency and content analysis was carried out. RESULTS: QHR has expanded significantly, both nationally and internationally, and papers published in public health and social medicine journals. However, several factors impede its consolidation: the institutional, territorial and thematic concentration of studies, the dependency on grounded theory, the selective nature of the research topics and populations; and its marginal scientific impact. CONCLUSIONS: QHR has grown in México, but its consolidation faces serious challenges. Several proposals are discussed that could strengthen the field

Effects of chloramphenicol, erythromycin, and furazolidone on growth of Isochrysis galbana and Chaetoceros gracilis

This study focused on determining the effects of antibiotics on microalgae used as food for scallop larvae. Six different dose levels of chloramphenicol, erythromycin, and furazolidone were added to cultures of Isochrysis galbana and Chaetoceros gracilis. An in vivo experiment was subsequently conducted to determine the effect of chloramphenicol and erythromycin on larval survival of the Pacific calico scallop Argopecten ventricosus in tanks and on the population of its associated bacteria. Results showed that growth of I. galbana was not significantly affected by chloramphenicol or erythromycin at the test doses of 0.5, 1.0, 3.0, 6.0, 9.0, and 12.0 mg/l. C. gracilis was significantly sensitive to erythromycin and chloramphenicol at doses higher than 0.5 and 3.0 mg/l, respectively. Furazolidone inhibited the growth of both I. galbana and C. gracilis at all test doses. Results showed that exposure of scallop larvae to a dose of 6 mg/l chloramphenicol or erythromycin did not significantly affect growth of I. galbana, significantly enhanced survival of the scallop larvae, and inhibited the growth of Vibrio spp. in tanks. This study demonstrated the adverse effect of chloramphenicol, erythromycin and furazolidone on I. galbana and C. gracilis microalgae but the positive effect on survival of the scallop larvae, decreasing associated bacterial population

Evaluation Of Leaf Harvesting Effect On Chamaedorea Quezalteca Standl. &Amp; Steyerm. (Palmae), In The El Triunfo Biosphere Reserve, Chiapas, México

The leaves of the Chamaedorea quezalteca palm are an important non-timber forest resource for the dwellers of the Sierra Madre de Chiapas, México. The aim of this study was to evaluate the effect of artificial defoliation during one year (July 2008 to July 2009) on leaf production, mortality and reproduction of C. quezalteca at three sites of the El Triunfo Biosphere Reserve, Chiapas, México. Six hundred individuals were selected in three size categories defined by the number of stems (1-3, 4-6 and \u3e7). The experimental design was mixed factorial with two fixed factors (treatment and size) and one random (site), and forest cover as a covariate, with three treatments of defoliation (30, 60 and 100 %) and the control (0 %); an analysis of variance was performed with the data. The production of leaves was significant (p≤0.05) in relation to plant size and intensity of defoliation, but such response depended on the combination of factor levels. Leaf production increased with harvest intensity (defoliation) and size categories. During the experiment, eight individuals were recorded dead and 20 % of all the selected individuals lost one or more stems. No differences were found (p≤0.05) between treatments and the control in the production of inflorescences and infructescences between the start of the experiment and after one year, nor in fruit production after a year. Results indicate that leaf harvest in an annual period increased leaf production but did not change the reproduction and survival of individuals

Viviendo con trasplante renal, sin protección social en salud: ¿Qué dicen los enfermos sobre las dificultades económicas que enfrentan y sus efectos?

El trasplante es el mejor tratamiento para la insuficiencia renal, de acuerdo con la biomedicina; sin embargo, es una tecnología cara. Este artículo examina las dificultades económicas y sus efectos en personas con trasplante renal, pero sin protección social en salud. Para el estudio se desarrolló una investigación cualitativa en México. Participaron 21 pacientes trasplantados; se aplicaron entrevistas semiestructuradas, y se realizó un análisis de contenido. Los resultados muestran que las personas enfermas enfrentan dificultades económicas, debido a los costes de las terapias renales, particularmente, de las medicinas. Todo ello tiene efectos negativos: las personas con pocos recursos dejan el tratamiento con medicamentos, abandonan el protocolo, no asisten a las consultas médicas y disminuyen los gastos domésticos, incluyendo el de alimentación; además de suponer una merma en los ingresos familiares. En conclusión, el trasplante renal empobrece a las personas enfermas sin protección social en salud; es urgente la implementación de un sistema de protección social para esta población