56 research outputs found
Cyanobacterial Diversity and a New Acaryochloris-Like Symbiont from Bahamian Sea-Squirts
Symbiotic interactions between ascidians (sea-squirts) and microbes are poorly understood. Here we characterized the cyanobacteria in the tissues of 8 distinct didemnid taxa from shallow-water marine habitats in the Bahamas Islands by sequencing a fragment of the cyanobacterial 16S rRNA gene and the entire 16S–23S rRNA internal transcribed spacer region (ITS) and by examining symbiont morphology with transmission electron (TEM) and confocal microscopy (CM). As described previously for other species, Trididemnum spp. mostly contained symbionts associated with the Prochloron-Synechocystis group. However, sequence analysis of the symbionts in Lissoclinum revealed two unique clades. The first contained a novel cyanobacterial clade, while the second clade was closely associated with Acaryochloris marina. CM revealed the presence of chlorophyll d (chl d) and phycobiliproteins (PBPs) within these symbiont cells, as is characteristic of Acaryochloris species. The presence of symbionts was also observed by TEM inside the tunic of both the adult and larvae of L. fragile, indicating vertical transmission to progeny. Based on molecular phylogenetic and microscopic analyses, Candidatus Acaryochloris bahamiensis nov. sp. is proposed for this symbiotic cyanobacterium. Our results support the hypothesis that photosymbiont communities in ascidians are structured by host phylogeny, but in some cases, also by sampling location
The peatland map of Europe
Based on the ‘European Mires Book’ of the International Mire Conservation Group (IMCG), this article provides a composite map of national datasets as the first comprehensive peatland map for the whole of Europe. We also present estimates of the extent of peatlands and mires in each European country individually and for the entire continent. A minimum peat thickness criterion has not been strictly applied, to allow for (often historically determined) country-specific definitions. Our ‘peatland’ concept includes all ‘mires’, which are peatlands where peat is being formed. The map was constructed by merging national datasets in GIS while maintaining the mapping scales of the original input data. This ‘bottom-up’ approach indicates that the overall area of peatland in Europe is 593,727 km². Mires were found to cover more than 320,000 km² (around 54 % of the total peatland area). If shallow-peat lands (< 30 cm peat) in European Russia are also taken into account, the total peatland area in Europe is more than 1,000,000 km2, which is almost 10 % of the total surface area. Composite inventories of national peatland information, as presented here for Europe, may serve to identify gaps and priority areas for field survey, and help to cross-check and calibrate remote sensing based mapping approaches
Hábitos y conocimientos alimentarios de adolescentes nadadores de rendimiento
The aim of this study was to assess the general eating habits and the nutritional knowledge of a group of
adolescent performance swimmers. 20 swimmers (10 men, 10 women, mean age: 14.85 years, SD = 1.5)
and 20 controls performance sport activities (11 men, 9 women, average age: 14.50 years, SD =0.68)
participated in this study. Nutritional Knowledge Questionnaire (Bach, 2003), Knowledge and Attitudes
on Nutrition Questionnaire (Zawila, 2003) and an adaptation of the Lifestyles Project OBA questionnaire
(cf. Sánchez-Carracedo and Saldaña, 1998 ) were used. The results showed that swimmers had an average
nutrition knowledge and they were generally better informed about nutrition (p <0001) and nutrition
for the athlete (p = 0063) than their controls, meanwhile dietary habits of the two groups were similar.
Dietary habits of swimmers must be oriented. It is necessary to promote the role of coaches as informants
on nutrition.Con este trabajo pretendemos conocer los hábitos generales de alimentación y los conocimientos sobre
nutrición de un grupo de adolescentes nadadores de rendimiento. En el estudio participaron 20 nadadores
(10 hombres, 10 mujeres, edad media = 14,85 años, SD = 1,5) y 20 controles (11 hombres, 9 mujeres,
edad media = 14,50 años, SD = 0,68). Se aplicó el cuestionario de Conocimiento Nutricional (Bach, 2003),
el Cuestionario de Conocimiento y Actitudes Nutricionales (Zawila, 2003) y una adaptación del cuestionario
de Estilos de Vida del proyecto OBA (cfr. Sánchez-Carracedo y Saldaña, 1998). El conocimiento
nutricional de los nadadores fue medio y se mostraron mejor informados sobre nutrición general (p <
,001) y nutrición para el deportista (p = ,063) que sus controles, pero no se encontraron diferencias en los
hábitos alimentarios. Los hábitos alimentarios de los nadadores deben ser orientados. Debería fomentarse
el papel de los entrenadores como informadores sobre nutrición
Polyphasic characterization of benthic, moderately halophilic, moderately thermophilic cyanobacteria with very thin trichomes and the proposal of Halomicronema excentricum gen. nov., sp nov.
A new genus of moderately halophilic, moderately halotolerant and moderately thermophilic cyanobacteria with very thin trichomes is described. The four strains included in this genus were isolated from benthic microbial mats in a man-made hypersaline pond. Trichomes were around 1 mum thick, with small constrictions at the cross-walls and diffluent colorless sheaths. Thylakoids were parallel to the cell wall, but thylakoids and nucleoid were often excentrically arranged within the cytoplasm with respect to the main trichome axis. Strains grew at between 3.2 and 12-15% (w/v) salinity with optima between 3.2 and 12%. They showed lower temperature limits around 20degreesC and upper limits between 45 and 50degreesC, with optima between 28 and 45-50degreesC. Carotenoid and mycosporine amino-acid complements were identical among strains. Phylogenetic analyses based on 16S rRNA gene sequence showed that all strains were closely related (99% or higher similarity) and distantly related to other cyanobacteria (91% or lower similarity). We propose the new genus and species Halomwicronema excentricum for these strains. The type strain is TFEP1
Is there genetic differentiation in the Pyrenean population of Tengmalm's owl Aegolius Funereus?
Several boreal taxa can be found in southern latitudes in fragments of high altitude alpine habitat. Some of these taxa have remained isolated from the main populations in northern latitudes as a result of the distribution changes during the last glaciations, being known as glacial relict populations. Such relict populations have often differentiated from the main population as a result of isolation and genetic drift. The Tengmalm's owl Aegolius funereus is a widespread boreal forest species distributed throughout boreal Eurasia and North America. The westernmost Eurasian breeding population is located in the Pyrenees Mountains, and was discovered less than 50 years ago. We studied the genetic structure of this Pyrenean population of Tengmalm's owl, and compared it with a northern latitude population from Fennoscandia. Despite being isolated by several hundred kilometres from the closest breeding grounds, we found no differences in the genetic structure of the mitochondrial DNA when compared with the central population. Our results suggest that this population has been recently, or still is connected with the main population.Peer Reviewe
Polyphasic characterization of benthic, moderately halophilic, moderately thermophilic cyanobacteria with very thin trichomes and the proposal of Halomicronema excentricum gen. nov., sp nov.
A new genus of moderately halophilic, moderately halotolerant and moderately thermophilic cyanobacteria with very thin trichomes is described. The four strains included in this genus were isolated from benthic microbial mats in a man-made hypersaline pond. Trichomes were around 1 mum thick, with small constrictions at the cross-walls and diffluent colorless sheaths. Thylakoids were parallel to the cell wall, but thylakoids and nucleoid were often excentrically arranged within the cytoplasm with respect to the main trichome axis. Strains grew at between 3.2 and 12-15% (w/v) salinity with optima between 3.2 and 12%. They showed lower temperature limits around 20degreesC and upper limits between 45 and 50degreesC, with optima between 28 and 45-50degreesC. Carotenoid and mycosporine amino-acid complements were identical among strains. Phylogenetic analyses based on 16S rRNA gene sequence showed that all strains were closely related (99% or higher similarity) and distantly related to other cyanobacteria (91% or lower similarity). We propose the new genus and species Halomwicronema excentricum for these strains. The type strain is TFEP1
EVOLUCIÓN DE LA PREVALENCIA DE LA INFECCIÓN POR HELICOBACTER PYLORI (HP) EN LA POBLACIÓN DE TERRASSA
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