Spatial versus spatio-temporal approaches for studying metacommunities: a multi-taxon analysis in Mediterranean and tropical temporary ponds.

Prior research on metacommunities has largely focused on snapshot surveys, often overlooking temporal dynamics. In this study, our aim was to compare the insights obtained from metacommunity analyses based on a spatial approach repeated over time, with a spatio-temporal approach that consolidates all data into a single model. We empirically assessed the influence of temporal variation in the environment and spatial connectivity on the structure of metacommunities in tropical and Mediterranean temporary ponds.

The antagonistic effect of UV radiation on warming or nitrate enrichment depends on ecotypes of freshwater macroalgae (Charophytes).

Increases in ultraviolet radiation (UVR), a negative global change factor, affect aquatic primary producers. This effect is expected to be modulated by other global change factors, and to be different for populations adapted to different environments. A common garden experimental approach using freshwater green macroalgae, the cosmopolitan charophyte species Chara hispida and C.

Hydrology Affects Environmental and Spatial Structuring of Microalgal Metacommunities in Tropical Pacific Coast Wetlands.

The alternating climate between wet and dry periods has important effects on the hydrology and therefore on niche-based processes of water bodies in tropical areas. Additionally, assemblages of microorganism can show spatial patterns, in the form of a distance decay relationship due to their size or life form. We aimed to test spatial and environmental effects, modulated by a seasonal flooding climatic pattern, on the distribution of microalgae in 30 wetlands of a tropical dry forest region: the Pacific coast of Costa Rica and Nicaragua.

Inferring the relative resilience of alternative states.

Ecological systems may occur in alternative states that differ in ecological structures, functions and processes. Resilience is the measure of disturbance an ecological system can absorb before changing states. However, how the intrinsic structures and processes of systems that characterize their states affects their resilience remains unclear.

Allelopathic effects of microcystin-LR on the germination, growth and metabolism of five charophyte species and a submerged angiosperm.

Microcystins (MCs) are produced by cyanobacteria in aquatic environments and adversely affect macrophytes at very high concentrations. However, the effects of MC on macrophytes at concentrations of environmental relevance are largely unknown. The main objective of this study was to analyze the allelopathic effects of MC-LR at natural concentrations (1, 8 and 16 μg MC-LR/L) on five charophyte species (Chara aspera, C.

Unusual early recurrence of granular dystrophy after deep anterior lamellar keratoplasty: case report.

We report an atypical case of granular corneal dystrophy recurrence after deep anterior lamellar keratoplasty. We describe clinical features, histopathological analysis of the lamellar graft specimen and DNA analysis results. The slit-lamp examination and histopathological findings from the graft specimen indicated the confinement of the typical deposits of granular corneal dystrophy deep in the graft interface area.

Does seston size structure reflect fish-mediated effects on water quality in a degraded semiarid wetland?

This study evaluates whether the size structure of seston (the sum of living and nonliving particles in the water column) reflects the effects of fish on wetland water quality. Using enclosures, we measured water quality and zooplankton community structure in the presence and absence of two fish species with distinct foraging strategies [benthivorous carp (Cyprinus carpio) and planktivorous mosquitofish (Gambusia holbrooki)]. Seston collected from the enclosures was counted and sized automatically with a Coulter counter, and the size structure in the range of 1-60 microm was modelled using the underlying Pareto distribution of particles.

Perirenal fat diameter measured by echography could be an early predictor of lipodystrophy in HIV type 1-infected patients receiving highly active antiretroviral therapy.

Echographically measured thicknesses of perirenal and subcutaneous fat, as well as serum metabolic and anthropometric parameters, were evaluated in 74 human immunodeficiency virus-infected patients receiving highly active antiretroviral therapy (HAART), 22 of whom were HAART-naive at baseline, who were followed-up for 27 months to detect predictive factors of lipodystrophy. Perirenal fat diameter (PRFD) at baseline differed in HAART-naive and HAART-experienced patients (P<.001), and it was the best predictor of lipodystrophy changes after 12 months of follow-up in the HAART-naive patients (hazard ratio, 7.

Influence of aquatic microbiota on the survival in water of the human and eel pathogen Vibrio vulnificus serovar E.

The eel and human pathogen Vibrio vulnificus serovar E (biotype 2) is seldom isolated from natural waters, although it can survive in sterilized artificial seawater microcosms for years. The main objective of the present study was to investigate whether aquatic microbiota can limit its survival and recovery from water samples. A set of preliminary experiments of survival in microcosms containing natural seawater and water from eel farms showed that the persistence of this pathogen was mainly controlled by grazing, and secondarily by bacterial competition.