Análisis de los patrones de distribución de plancton en el Estrecho de Gibraltar asociados al forzamiento mareal y meteorológico

El Estrecho de Gibraltar es la única conexión entre la circulación global y el Mar Mediterráneo, el mayor cuerpo de agua semicerrado del planeta. Por lo tanto los procesos que aquí ocurren son claves para describir los flujos biogeoquímicos en la cuenca mediterránea y fundamentales para la circulación termohalina global. En el Estrecho se ha descrito una circulación “estuarina-inversa” con aguas atlánticas entrando en superficie y aguas mediterráneas más densas en profundidad. Sobre este patrón general existen alteraciones debidas al forzamiento mareal y el atmosférico o subinercial. La gran cantidad de procesos físicos y en varias escalas que ocurren en el Estrecho lo hacen muy atractivo desde el punto de vista del acoplamiento físicabiología en el ecosistema pelágico. El propósito de esta Tesis es la descripción de los patrones biogeoquímicos en el área de influencia del Estrecho, intentando cubrir un rango amplio de fenómenos con diferentes escalas espacio-temporales. Las zonas de plataforma a ambos márgenes del canal principal del Estrecho (especialmente la noroccidental) presentan una alta actividad del fitoplancton con células grandes y activas. En contraposición, la zona del canal originalmente presenta aguas oligotróficas provenientes del Golfo de Cádiz. Estas aguas oligotróficas (a través del NACW) aportan el 70% del nitrato transportado anualmente a las cuencas mediterráneas y el 55% de la biomasa fitoplanctonica. Sin embargo, existen intrusiones de aguas costeras hacia el canal relacionados con la generación de ondas internas y divergencias superficiales que éstas crean. Estos procesos se dan tanto en mareas vivas como en muertas, estando durante las vivas acompañados de alta mezcla interfacial. Los procesos derivados de las ondas internas (Tipo I) pueden significar un 30% del nitrato transportado hacia las cuencas mediterráneas, acompañadas de células activas y grandes. Este aporte también supone el 30% de la biomasa total del fitoplancton transportada. A su vez, la mezcla interfacial y adelgazamiento de la capa atlántica pueden alterar el ciclo estacional del fitoplancton de las aguas atlánticas entrantes. Estos procesos pueden aumentar la producción primaria y la biomasa, especialmente durante primavera y otoño. Estos procesos también favorecen la dominancia de nanoflagelados (primavera y otoño) y picofitoplancton (verano). Por otro lado, la turbulencia es capaz de redistribuir la biomasa del fitoplancton en vertical, siempre que existan las condiciones físico-biológicas para que se genere un máximo profundo. La relación entre turbulencia y velocidad de sedimentación del fitoplancton hace que estos máximos se sitúen bajo zonas de mayores niveles de turbulencia (mayores velocidades de sedimentación). En el futuro con mayor estratificación y mayor entrada superficial de turbulencia, la biomasa integrada de fitoplancton será menor en la capa de mezcla pero la exportación vertical de materia al océano profundo será mayor. Finalmente, los procesos ocurrentes en el Estrecho permiten que el Mar de Alborán reciba una aportación cuasi-constante de biomasa de fitoplancton y nutrientes, este último en un orden de magnitud mayor a la aportación de los afloramientos costeros descritos en esta cuenca. Estos fenómenos podrían fertilizar y mantener alta la producción primaria en esta área descrita como más productiva del Mediterráneo

Trastornos de ansiedad y del estado de ánimo en personas víctimas del conflicto armado en Colombia: el caso de Chengue y de Libertad

This research worked with victims of the armed conflict from two populations living in Montes de Maria area: Chengue (in the municipality of Ovejas) and Libertad (in the municipality of San Onofre). Each of these population lived different victimization stories. The first one had to move because of the experience of a violent event which precipitated the displacement; the second one had to live with an illegal armed group for a long period of time. The aim of the present study is to identify anxiety and mood disorders in native people which were born in Chengue and Libertad. In order to do this, a structured diagnostic interview was applied; this explores the major Axis I in DSM IV. A total of 129 individuals from Chengue and Libertad participated in the study. Results indicated that population of Libertad even though they lived with the armed group “guerrilla” in constant stressful conditions, showed less presence of emotional disorders in comparison with the population of Chengue. In this work possible reasons for explain this phenomenon are discussed.Para esta investigación se trabajó con víctimas del conflicto armado de dos poblaciones de los Montes de María: Corregimiento de Chengue, en el Municipio de Ovejas y Corregimiento de Libertad, en el Municipio de San Onofre. Cada una de estas poblaciones vivieron historias de victimización diferentes. La primera tuvo que desplazarse debido a un hecho violento que precipitó el desplazamiento y la segunda, convivió con miembros de las autodefensas por un largo período de tiempo. El objetivo de este estudio es identificar los trastornos de ansiedad y del estado de ánimo en personas oriundas del corregimiento de Chengue y del corregimiento de Libertad, que vivieron en estas poblaciones durante la época de ocurrencia de los hechos victimizantes. Para ello, se aplicó una entrevista diagnóstica estructurada de breve duración, que explora los principales trastornos psiquiátricos del Eje I del DSM-IV. Participaron 129 personas adultas de Ovejas y de Libertad. Entre los resultados se encontró que la población de Libertad aún a pesar de convivir con los paramilitares en condiciones de estrés constante, presentó menos prevalencia de trastornos emocionales en comparación con la población de Chengue. En este trabajo se abordan posibles razones para explicar este fenómeno

Biogeochemical patterns in the Atlantic Inflow through the Strait of Gibraltar

The effects of tidal forcing on the biogeochemical patterns of surface water masses flowing through the Strait of Gibraltar are studied by monitoring the Atlantic Inflow (AI) during both spring and neap tides. Three main phenomena are defined depending on the strength of the outflowing phase predicted over the Camarinal Sill: non-wave events (a very frequent phenomenon during the whole year); type I Internal wave events (a very energetic event, occurring during spring tides); and type II Internal wave events (less intense, occurring during neap tides). During neap tides, a non-wave event comprising oligotrophic open-ocean water from the Gulf of Cádiz is the most frequent and clearly dominant flow through the Strait. In this tidal condition, the inflow of North Atlantic Central Water (NACW) provides the main nutrient input to the surface layer of the Alboran Sea, supplying almost 70% of total annual nitrate transport to the Mediterranean basin. A low percentage of active and large phytoplankton cells and low average concentrations of chlorophyll (0.3–0.4 mg m−3) are found in this tidal phase. Around 50% of total annual phytoplankton biomass transport into the Mediterranean Sea through the Strait presents these oligotrophic characteristics. In contrast, during spring tides, patches of water with high chlorophyll levels (0.7–1 mg m−3) arrive intermittently, and these are recorded concurrently with the passage of internal waves coming from the Camarinal Sill (type I internal wave events). When large internal waves are arrested over the Camarinal Sill this implies strong interfacial mixing and the probable concurrent injection of coastal waters into the main channel of the Strait. These processes result in a mixed water column in the AI and can account for around 30% of total annual nitrate transport into the Mediterranean basin. Associated with type I internal wave events there is a regular inflow of large and active phytoplankton cells, transported in waters with relatively high nutrient concentrations, which constitutes a significant supply of planktonic resources to the pelagic ecosystem of the Alboran Sea (almost 30% of total annual phytoplankton biomass transport)

Kinetics of Transesterification of Safflower Oil to Obtain Biodiesel Using Heterogeneous Catalysis

The kinetics of the transesterification of safflower oil and methanol catalyzed by K2O/NaX was studied and modeled. The influence of the oil-methanol initial molar ratio and amount of catalyst were investigated to achieve a maximum triglycerides conversion (99%) and a final methyl esters content of 94% ± 1. A kineticmodel based on an Eley– Rideal mechanism was found to best fit the experimental data when assuming methanol adsorption as determining step. Other models derived from Langmuir – Hinshelwood – Hougen –Watson (LHHW) mechanisms were rejected based on statistical analysis, mechanistic considerations and physicochemical interpretation of the estimated parameters

Modelo de gestión de Educación Continua para Instituciones de Educación Superior

El presente trabajo se realiza al vislumbrar la no existencia de un modelo para la gestión de la Educación Continua que permita su adaptación a las diferentes características de las Instituciones de Educación Superior, siendo que los modelos existentes f

Dipylidium caninum, Ancylostoma spp., and Trichuris spp. Contamination in Public Parks in Mexico

Background : Zoonotic parasitoses are a public health problem because they are distributed worldwide. Soil contamina- tion with dog faeces is an important worldwide problem because it facilitates the transmission of zoonotic parasites. It has been reported in different studies that soil contamination by parasites represents a risk factor for the population (mainly children) to acquire parasitic diseases caused by Dipylidium caninum , Ancylostoma spp., and Trichuris spp. Therefore, the objectives of the present study were to analyse soil samples collected from fi ve public parks in the city of Nezahualcoyotl, Mexico for the presence of canine soil-transmitted parasites. Materials, Methods & Results : A total of 1726 soil samples were obtained from fi ve public parks in Nezahualcoyotl County, Mexico and analysed for Dipylidium caninum , Ancylostoma spp., and Trichuris spp. eggs. Sampling was carried out in summer 2009 with the permission of the Parks and Public Gardens Nezahualcoyotl Offi ce. Samples were evaluated using a fl otation method, using microscopic observation for egg identifi cation. The data were analysed with the Kruskal- Wallis test and average mean percentages of contamination between the parks means were compared using the Nemenyi test. There were differences in the degree of contamination among the parks, but the soil characteristics were not correlated with the presence of parasite eggs. Contamination with Dipylidium caninum and Trichuris spp. were positively correlated (r = 0.32, P < 0.0001). Overall, there was a substantial frequency of Ancylostoma spp. (23.7%) and Dipylidium caninum (21.7%), with minor presence of Trichuris spp. (15.3%) in the parks. Discussion : Several studies have shown that the close relationship between resulting from the human-animal bond provides benefi ts for socialisation, mental health, and even physical well-being. However, owning a pet also allows potential health risks for the human population. Incidence studies of parasites in the soil of public parks provide greater insight regarding their zoonotic potential, and revealed that the soil of public parks is a source of infection and transmission of parasitic diseases. The reports on soil parasites contamination vary depending on where in the in the world were conducted. Studies in Brazil and Argentina had twice the levels of contamination for Ancylostoma spp. eggs andlower levels of D. caninum . However, the degree of contamination for Trichuris spp. in this report was higher than that observed in public parks in other countries (Croatia, Nigeria, and Brazil). These studies indicate that the risk of acquiring a zoonotic parasitic infec- tion is extremely high, since the soil is highly contaminated with infectious eggs of parasites. The study of the prevalence of parasites in dogs and understanding of the life cycle, epidemiology, and risk factors involved require the establishment of prevention programs for public health reason. Therefore, it is important to implement measures for the collection of excreta in public parks and promote dog deworming programs and hygiene measures to prevent infection in paratenic hosts. The results of this research revealed that the soil of public parks were a source of parasitic zoonoses, because dogs play an important role in the contamination of soils by excreting intestinal parasites through their faeces, constituting a public health problem

Interannual changes in zooplankton echo subtropical and high latitude climate effects in the southern East China Sea

Climate variability plays a central role in the dynamics of marine pelagic ecosystems shaping the structure and abundance changes of plankton communities, thereby affecting energy pathways and biogeochemical fluxes in the ocean. Here we have investigated complex interactions driven a climate-hydrology-plankton system in the southern East China Sea over the period 2000 to 2012. In particular, we aimed at quantifying the influence of climate phenomena playing out in tropical (El Nino 3.4) and middle-high latitudes (East Asia Winter Monsoon, EAWM, and Pacific Decadal Oscillation, PDO) on pelagic copepods. We found that the EAWM and El Nino 3.4 showed a non-stationary and non-linear relationship with local temperature variability. In the two cases, the strength of the relationship, as indexed by the wavelet coherence analysis, decreased along with the positive phase of the PDO. Likewise, the influence of EAWM and El Nino3.4 on copepods exhibited a non-stationary link that changed along with the PDO state. Indeed, copepods and EAWM were closely related during the positive phase, while the link copepods–El Nino 3.4 was stronger during the negative phase. Our results pointed out cascading effects from climate to plankton driven by the positive phase of the PDO through its effect on temperature conditions, and likely through a larger southward transport of nutrient-rich water masses to northern Taiwan and the Taiwan Strait. We suggest a chain of mechanisms whereby the PDO shapes interannual dynamics of pelagic copepods and highlight that these results have implications for integrative management measures, as pelagic copepods plays a prominent role in food web dynamics and for harvested fish in the East China Sea. © 2018 Molinero et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited

Inmovilización de óxidos obtenidos a partir de compuestos tipo hidrotalcita en monolitos reticulados de α-al2o3 para la degradación de un contaminante fenólico

La contaminación de agua ocasionada por sustancias orgánicas e inorgánicas ha dejado de ser un problema ambiental para convertirse en una severa amenaza a la salud pública. Los fenoles y algunos de sus derivados, en especial el 4-clorofenol (4CP), son contaminantes refractarios que tienen omnipresencia en el ambiente debido a su amplio uso en diversas actividades industriales: agricultura, petroquímica y procesos de manufactura, por mencionar algunas. El 4CP se le conoce por ser un disruptor endócrino capaz de alterar el sistema hormonal tanto de humanos como de animales, además, se considera tóxico a bajas concentraciones. La Unión Europea establece que las concentraciones máximas en agua potable de fenoles y de algún compuesto fenólico en particular deben estar por debajo de los 0.5 y 0.1 μg/L, respectivamente (Rodrı́guez, Llompart e Cela, 2000). Algunos métodos tradicionales de tratamiento de aguas residuales como la precipitación química, adsorción por carbón activado e intercambio iónico, han sido efectivos en la remoción de clorofenoles, sin embargo, estos procesos solo transfieren a los contaminantes de un medio a otro provocando la necesidad de un tratamiento posterior, o un plan de confinamiento de los residuos. Los métodos biológicos son otra alternativa interesante debido a su bajo costo y elevada disponibilidad de cultivos aerobios, sin embargo, la toxicidad de los clorofenoles y la de sus intermedios restringe la capacidad de los microrganismos, provocando que estas técnicas adquieran limitaciones serias para la completa mineralización de químicos tóxicos no-biodegradables (Goel et al., 2010)

Interannual changes in zooplankton echo subtropical and high latitude climate effects in the southern East China Sea

Climate variability plays a central role in the dynamics of marine pelagic ecosystems shaping the structure and abundance changes of plankton communities, thereby affecting energy pathways and biogeochemical fluxes in the ocean. Here we have investigated complex interactions driven a climate-hydrology-plankton system in the southern East China Sea over the period 2000 to 2012. In particular, we aimed at quantifying the influence of climate phenomena playing out in tropical (El Nino 3.4) and middle-high latitudes (East Asia Winter Monsoon, EAWM, and Pacific Decadal Oscillation, PDO) on pelagic copepods. We found that the EAWM and El Nino 3.4 showed a non-stationary and non-linear relationship with local temperature variability. In the two cases, the strength of the relationship, as indexed by the wavelet coherence analysis, decreased along with the positive phase of the PDO. Likewise, the influence of EAWM and El Nino3.4 on copepods exhibited a non-stationary link that changed along with the PDO state. Indeed, copepods and EAWM were closely related during the positive phase, while the link copepods–El Nino 3.4 was stronger during the negative phase. Our results pointed out cascading effects from climate to plankton driven by the positive phase of the PDO through its effect on temperature conditions, and likely through a larger southward transport of nutrient-rich water masses to northern Taiwan and the Taiwan Strait. We suggest a chain of mechanisms whereby the PDO shapes interannual dynamics of pelagic copepods and highlight that these results have implications for integrative management measures, as pelagic copepods plays a prominent role in food web dynamics and for harvested fish in the East China Sea.Fil: Molinero, Juan Carlos. Geomar-Helmholtz Centre for Ocean Research Kiel; Alemania. Université Montpellier II; FranciaFil: Tseng, Li-Chun. National Taiwan Ocena University; ChinaFil: López Abbate, María Celeste. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; ArgentinaFil: Ramirez-Romero, Eduardo. Consejo Superior de Investigaciones Cientificas. Instituto Mediterraneo de Estudios Avanzados; EspañaFil: Hwang, Jiang-Shiou. National Taiwan Ocena University; Chin

Determination of the angular momentum of the Kerr black hole from equatorial geodesic motion

We present a method to determine the angular momentum of a black hole, based on observations of the trajectories of the bodies in the Kerr space-time. We use the Hamilton equations to describe the dynamics of a particle and present results for equatorial trajectories, obtaining an algebraic equation for the magnitude of the black hole's angular momentum. We tailor a numerical code to solve the dynamical equations and use it to generate synthetic data. We apply the method in some representative examples, obtaining the parameters of the trajectories as well as the black hole's angular momentum in good agreement with the input data.Comment: 24 page