The ecology of the Mar Menor coastal lagoon: A fast changing ecosystem under human pressure

The Mar Menor is a hypersaline coastal lagoon, with a surface area of 135 km2 and a perimeter of 59.51 km. It is located on the southwestern Mediterranean coastline (3742′00′′N, 0047′00′′W) with a mean depth of 3.6 m and a maximum depth of 6 m. “La Manga,” a sandy bar 22 km long and 100–900 m wide, acts as a barrier between the lagoon and the Mediterranean Sea. It is crossed by five more or less functional inlets called golas. Four are shallow (less than 1 m deep) and one of them, El Estacio, was widened and dug to a 5-m depth to make it a navigational channel. Altogether a total width of lagoon entrances is about 645 m, giving Mar Menor a restriction ratio of 0.015. Mar Menor is therefore a restricted lagoon according to the classification proposed by Kjerfve1 (see Chapter 6). There are two main islands and three other smaller islands, one of which is artificially connected to La Manga

TÉCNICAS DE RECOLECCIÓN Y ESTUDIO EN LA CLASE HOLOTHUROIDEA. 1. GENERALIDADES, SISTEMÁTICA, ECOLOGÍA, BIOLOGÍA Y COMPORTAMIENTO

Studies about holothunans in Spain are scarce and they are reduced to some faunistic or systematic notes. In this paper some of the methods habitually employed in the different aspects of the systematic (sampling and preservation, preparation of spicules. calcareous ring, etc.), biological (reproduction, development, growth, nutrition and activity) and ecological (evaluation of the populations, incidence of the environmental factors) studies of this group of echinoderms are presented.En España los estudios sobre las holoturias son escasos y se reducen a algunas notas faunísticas o sistemáticas. En este trabajo se presentan algunas de las técnicas empleadas habitualmente por los investigadores en los distintos aspectos de la sistemática (recolección y conservación, preparación de espículas, anillo calcáreo, etc.), biología (reproducción, desarrollo, crecimiento, nutrición, actividad) y ecología (evaluación de las poblaciones. incidencia de los factores ambientales) de este grupo de equinodermos

Genetic diversity and connectivity remain high in Holothuria polii (Delle Chiaje 1823) across a coastal lagoon-open sea environmental gradient

Coastal lagoons represent habitats with widely heterogeneous environmental conditions, particularly as regards salinity and temperature, which fluctuate in both space and time. These characteristics suggest that physical and ecological factors could contribute to the genetic divergence among populations occurring in coastal lagoon and open-coast environments. This study investigates the genetic structure of Holothuria polii at a micro-geographic scale across the Mar Menor coastal lagoon and nearby marine areas, estimating the mitochondrial DNA variation in two gene fragments, cytochrome oxidase I (COI) and 16S rRNA (16S). Dataset of mitochondrial sequences was also used to test the influence of environmental differences between coastal lagoon and marine waters on population genetic structure. All sampled locations exhibited high levels of haplotype diversity and low values of nucleotide diversity. Both genes showed contrasting signals of genetic differentiation (non-significant differences using COI and slight differences using 16S, which could due to different mutation rates or to differential number of exclusive haplotypes. We detected an excess of recent mutations and exclusive haplotypes, which can be generated as a result of population growth. However, selective processes can be also acting on the gene markers used; highly significant generalized additive models have been obtained considering genetic data from 16S gene and independent variables such as temperature and salinity.Coastal lagoons represent habitats with widely heterogeneous environmental conditions, particularly as regards salinity and temperature, which fluctuate in both space and time. These characteristics suggest that physical and ecological factors could contribute to the genetic divergence among populations occurring in coastal lagoon and open-coast environments. This study investigates the genetic structure of Holothuria polii at a micro-geographic scale across the Mar Menor coastal lagoon and nearby marine areas, estimating the mitochondrial DNA variation in two gene fragments, cytochrome oxidase I (COI) and 16S rRNA (16S). Dataset of mitochondrial sequences was also used to test the influence of environmental differences between coastal lagoon and marine waters on population genetic structure. All sampled locations exhibited high levels of haplotype diversity and low values of nucleotide diversity. Both genes showed contrasting signals of genetic differentiation (non-significant differences using COI and slight differences using 16S, which could due to different mutation rates or to differential number of exclusive haplotypes. We detected an excess of recent mutations and exclusive haplotypes, which can be generated as a result of population growth. However, selective processes can be also acting on the gene markers used; highly significant generalized additive models have been obtained considering genetic data from 16S gene and independent variables such as temperature and salinity

Stabilisation of mixed peptide/lipid complexes in selective antifungal hexapeptides

AbstractThe design of antimicrobial peptides could have benefited from structural studies of known peptides having specific activity against target microbes, but not toward other microorganisms. We have previously reported the identification of a series of peptides (PAF-series) active against certain postharvest fungal phytopathogens, and devoid of toxicity towards E. coli and S. cerevisiae [López-Garcı́a et al. Appl. Environ. Microbiol. 68 (2002) 2453]. The peptides inhibited the conidia germination and hyphal growth. Here, we present a comparative structural characterisation of selected PAF peptides obtained by single-amino-acid replacement, which differ in biological activity. The peptides were characterised in solution using fluorescence and circular dichroism (CD) spectroscopies. Membrane and membrane mimetic–peptide interactions and the lipid-bound structures were studied using fluorescence with the aid of extrinsic fluorescent probes that allowed the identification of mixed peptide/lipid complexes. A direct correlation was found between the capability of complex formation and antifungal activity. These studies provide a putative structural basis for the mechanism of action of selective antifungal peptides

First records of non-indigenous Timarete caribous (Grube, 1859) (Polychaeta; Cirratulidae) in the Western Mediterranean, and its ecology in the Mar Menor (Murcia, SE Spain)

The knowledge and control of invasive species are essential in the management of marine ecosystems. The Mediterranean Sea is one of the marine areas with the highest number of invasive species detected, most of them invertebrates. On a smaller scale, colonization by non-native species in coastal lagoons depends directly on their connectivity with the adjacent sea and on the changes in their environmental conditions induced mainly by human interventions. In this study, the cirratulid species Timarete caribous Grube, 1859, native from the Western and Central Atlantic Ocean, was detected for the first time in a Western Mediterranean coastal lagoon, the Mar Menor. It has been found in dense aggregates on both artificial and natural rocky substrates, mainly in the most important communication channel with the Mediterranean Sea. Following the evolution of this NIS will be important for understanding the dynamic and spread of the species and its possible effects on the indigenous biological communitie

Cartografía bionómica del poblamiento bentónico de las islas del Mar Menor. 1: Islas Perdiguera y del Barón.

Bionomic cartography of the benthic assem blages of the Mar Menor lagoon islands. 1: Perdiguera and Barón islands. The bionomic composition and cartography is given of the hard and soft bottoms of two of the islands of the Mar Menor lagoon, an hypersaline water basin on the SE Spain coast. The tittoral wnation etages are narrow (because of the reduced hydrodynamism), reduced in number (the circalittoral etage laeks due to lhe lagoon shallowness) and of empoverished faunistie and floristie composition when compared with the neighboring Mediterranean ones (because of the environmenta1 stresses associated to an hypersaline lagoon environment). The rocky substrates are also reduced in extent, and lhere are virtually no sciaphi1ic communities. In general, lhe benthie assemblages are those eorresponding to the euryhaline and eurytherma1 lagoon community of PÉRES & PICARD ( 1 964), bul the large size of lhe lagoon and i lS increasing water exchangc with the Mediterranean have somewhat diversified the benthic communities, which now lie half way between the typically marine and those proper of Mediterranean coastal lagoons. The main communities are those dominatcd by macrophytes on 50ft bOlloms (infralittoral etage): the meadows of Cau/erpa prolifera and of Caulerpa-Cymodocea on muddy bonoms, and those of Cymodocea nodosa on sandy ones. PhOlOphilic algae communities, of varying but tinúted composition, are restricted to the hard bottoms.Bionomic maps and represenlative transects of these two islands bottoms are given; the other islands of the lagoon will be dealt with in a fortheoming paper, where the overall bionomic features of the lagoon benthic eommunities wiU be treated.B ionomic cartography of the benthic assem blages of the Mar Menor lagoon islands. 1: Perdiguera and Barón islands. The bionomic composition and cartography is given of the hard and soft bottoms of two of the islands of the Mar Menor lagoon, an hypersaline water basin on the SE Spain coasl. The tittoral wnation etages are narrow (because of the reduced hydrodynamism), reduced in number (the circalittoral etage laeks due to lhe 1agoon shallowness) and of empoverished faunistie and floristie eomposition when compared wilh the neighboring Mediterranean ones (because of the environmenta1 stresses associated to an hypersaline lagoon environment). The rocky substrates are also reduced in extent, and lhere are virtually no sciaphi1ic communities. In general, lhe benthie assemblages are those eorresponding to the euryhaline and eurytherma1 lagoon community of PÉRES & PICARD ( 1 964), bul the large size of lhe lagoon and i lS increasing water exchangc with the Mediterranean have somewhat diversified the benthic communities, which now lie half way between the typically marine and those proper of Mediterranean coastal lagoons. The main communities are those dominatcd by macrophytes on 50ft bOlloms (infralittoral etage): the meadows of Cau/erpa prolifera and of Caulerpa-Cymodocea on muddy bonoms, and those of Cymodocea nodosa on sandy ones. PhOlOphilic algae communities, of varying but tinúted composition, are restricted to the hard bottoms.Bionomic maps and represenlative transects of these two islands bottoms are given; the other islands of the lagoon will be dealt with in a fortheoming paper, where the overall bionomic features of the lagoon benthic eommunities wiU be treated

Respuesta ecofisiológica y capacidad de fotoaclimatación de las praderas de Caulerpa prolifera (Forsskal) J.V. Lamouroux y Cymodocea nodosa (Ucria) Ascherson en el Mar Menor (Murcia, España)

Tras el ensanchamiento en 1972 del principal canal de comunicación con el Mediterráneo, la macroalga Caulerpa prolifera colonizó el Mar Menor. Durante más de tres décadas, su expansión gradual ha reducido las praderas de Cymodocea nodosa, existentes en la laguna, a manchas dispersas en zonas arenosas someras. El objetivo principal es describir la respuesta ecofisiológica y la capacidad de aclimatación de ambas especies con el fin de determinar la influencia de estos mecanismos en la distribución actual de las mismas. La fluorescencia de la clorofila a asociada al fotosistema II se empleó para determinar los parámetros fotosintéticos. Se midieron diversos mecanismos fotoprotectores y antioxidantes (concentración de fenoles, actividad antioxidante mediante el método de DPPH), concentración de clorofilas y carotenoides, así como el contenido interno de C y N, para caracterizar la respuesta fisiológica de ambas especies. Asimismo, se llevaron a cabo experimentos de exposición a altas irradiancias y recuperación en oscuridad para valorar su capacidad de aclimatación. Se encontraron valores bajos de los parámetros fotosintéticos (tasa de transporte electrónico máximo, eficiencia fotosintética) en C. prolifera. Sin embargo, se observó una mayor capacidad fotosintética y la ausencia de fotoinhibición en C. nodosa, además de una alta concentración de luteína y un alto grado de de-epoxidación correlacionado con un mayor amortiguamiento no fotoquímico. Los resultados muestran que C. prolifera se comporta como una especie de sombra con una baja capacidad fotoprotectora, siendo la luz uno de los principales factores que determinan su distribución en la laguna. Sin embargo, C. nodosa muestra estar altamente fotoaclimatada a altas irradiancias y su distribución no está directamente relacionada con el ambiente lumínico. Así la regresión de las praderas de Cymodocea, que se observó antes del deterioro de la calidad del agua de la laguna, podría estar relacionada con otros factores ambientales (exceso de materia orgánica, carbonatos en sedimentos, hipoxia…) o con la competencia con C. prolifera. Es necesario realizar experimentos manipulativos para profundizar en el conocimiento de la actual distribución de ambas especies.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

La seguridad del medicamento en Atención Primaria

La práctica sanitaria conlleva riesgos para los pacientes y profesionales que les atienden. El estudio APEAS (Estudio sobre Seguridad de los Pacientes en Atención Primaria) puso de manifiesto el papel de los medicamentos tanto en el origen como en la consecuencia de los efectos adversos (en el 48,2% de los efectos adversos los factores causales estaban relacionados con la medicación). La utilización de los medicamentos constituye un sistema complejo que incluye los procesos de selección, prescripción, dispensación, administración y seguimiento. Esta complejidad conlleva un mayor riesgo de que se produzcan errores. En el ámbito de la atención primaria, desde comienzos de los años noventa, se ha estado trabajando con los profesionales en el desarrollo de un programa de uso racional del medicamento (URM). El uso seguro de la medicación es un pilar fundamental del programa de URM. En este trabajo se revisan los aspectos del URM en relación con la prevención de de riesgos en el uso de la medicación y en particular, los aspectos relacionados con la prescripción y los pacientes más vulnerables, los crónicos polimedicados

Estudio de la carga interna en pádel amateur mediante la frecuencia cardíaca

Los objetivos de este estudio fueron evaluar el nivel de condición física de 8 sujetos amateur de pádel, definir su perfil energético de esfuerzo en juego real mediante registro de frecuencia cardíaca (FC), y proponer un conjunto de variables justificadas de esta, que permita analizar el perfil de carga interna en pádel. Mediante prueba de esfuerzo incremental máxima en cinta de correr se obtuvieron parámetros ergoespirométricos, respiratorios y sus equivalentes cardíacos, introducidos en el sistema de registro de la FC Polar Team. Los sujetos disputaron 7 partidos de entrenamiento de 1 hora de duración y 72-96 horas de separación entre ellos, obteniéndose como variables: consumo máximo de oxígeno (VO2 máx) y porcentaje (%) de VO2 máx en el umbral anaeróbico; en prueba de esfuerzo, FC máx., media y mín., y zonas de trabajo metabólicas (rangos de FC). Los resultados presentan VO2 máx de 51,15 ± 5,73 ml · kg–1 · min–1, FC máx. durante el juego de 154,75 ± 7,25 ppm, FC med de 130,0 ± 10,4 ppm para tiempo de juego y 89,75 % del tiempo de juego en zona de trabajo aeróbica. Como conclusión, el esfuerzo al que son sometidos durante el juego a nivel cardiorrespiratorio los jugadores amateur de pádel se basa casi exclusivamente en metabolismos aeróbicos. Además, las variables máx., mín. y media de FC para tiempos de juego y descanso y el establecimiento de zonas de trabajo de FC pueden aportarnos información importante sobre lo que ocurre en el juego a nivel cardiorrespiratorio

Influence of a physical exercise until exhaustion in normothermic and hyperthermic conditions on serum, erythrocyte and urinary concentrations of magnesium and phosphorus

Aim: The aim of this study was to evaluate the effect of the performance of a maximal exercise test until exhaustion in normothermic and hyperthermic conditions on body concentrations of magnesium (Mg) and phosphorus (P). Methods: 19 adult males (age: 22.58 ± 1.05 years) performed two maximum incremental exercise tests on a cycloergometer separated by 48 h. The first was performed in normothermia (22 ± 2 °C) and the second in hyperthermic conditions induced with a sauna (42 ± 2 °C). Blood and urine samples were taken before and after each test. Results: The tests in hyperthermia did not produce ergospirometric alterations or a noticeable cardiovascular drift. Serum Mg concentrations underwent a reduction after the stress test in hyperthermia (p > 0.05) but not in normothermia. Nevertheless, urinary and erythrocyte concentrations of Mg, and urinary, erythrocyte and serum concentrations of P did not undergo alterations in either conditions. Conclusions: It seems that exercise in hyperthermic conditions induces a tissue redistribution of Mg in the body, a fact which was not observed in normothermic conditions