No abstract

The summer phytoplankton population in the Arcos reservoir (Spain), an oligotrophic/mesotrophic waterbody, was dominated by the cyanobacterium Aphanizomenon ovalisporum, accompanied by Planktothrix cf. agardhii and smaller proportions of other cyanobacterial species. The bloom remained for approximately 1 month in the summer of 2004. The Arcos reservoir had moderate conductivity, up to 1756 mS cm À1, and relatively high nutrient concentrations. Planktonic biomass collected during the bloom period was found to be toxic by the Artemia salina bioassay. Analytical procedures based on high-performance liquid chromatography (HPLC) indicated the absence of microcystins and anatoxin-a but clearly demonstrated the presence of cylindrospermopsin (CYN), suggesting that CYN from Aphanizomenon ovalisporum was the compound responsible for the toxicity in the bioassay. Measurements indicate that up to 9.4 mg CYN l À1 were present in the sestonic fraction. This is the first report of high concentrations of this cyanotoxin in European waters and the first known instance of a massive bloom of the cyanobacterium Aphanizomenon ovalisporum in Spain.

The occurrence and concentration of microcystins were analysed in sestonic samples from seven water reservoirs in the Madrid region (Spain) between July and November in two consecutive years (2002 and 2003). The data collected indicate that microcystins were present on several occasions in both years in all the reservoirs studied. The months of maximum risk for cyanotoxin occurrence were July, September and October, when Microcystis typically dominated the phytoplankton community. Four of the seven reservoirs exhibited conspicuous blooms, three of which were toxic. Of the samples in 2003, 45% and 70%, respectively, contained microcystins (Mc). In four of the reservoirs, microcystin concentrations were higher than the WHO recommended limit for drinking water (1 mg Mc l . From the data obtained we can conclude that M. aeruginosa is the main producer of microcystins in freshwaters from the Madrid region.

ABSTRACT. The influence of gamma-(γ) and beta-(β) diversity on modern pollen rain is assessed using data from three Amazonian forests. Pollen rain of 79 forest locations was collected in modified Oldfield pollen traps between 1991 and 1993. Pollen diversity in the traps was high with > 280 palynomorph types recognized. Gamma diversity was assessed by comparing lowland terra firme forests in Cuyabeno, Ecuador, with two terra firme forests near Manaus, Brazil. The influence of β-diversity on local pollen rain was investigated using samples collected from neighbouring terra firme forests, seasonally flooded forests, and Mauritia-rich forests at Cuyabeno, Ecuador. Multivariate analyses revealed that γ-diversity produces a stronger signal in the pollen rain than β-diversity. However, β-diversity is accurately reflected in the pollen rain when the diversity is an expression of strong environmental gradients.

This paper describes a methodology to extract a consistent human settlement extent layer using Landsat data and its implementation in the Google Earth Engine platform. The approach allows the extraction of human settlement extents by means of the existing Landsat 5 and 7 data sets, allowing to check their evolution at 30-m spatial resolution. Since human settlements are the main proxy to people geographical distribution and to building locations, this layer may serve as a mean to disaggregate people/building counts at the regional/national level. The approach is tested in several parts of the world against existing ground truth data at the same spatial resolution in Brazil and China, as well as against extents manually extracted from VHR data in three different geographical areas: 1) Brazil; 2) South East China; and 3) Indonesia.Index Terms-Global mapping, Landsat, normalized difference spectral vector (NDSV), urban remote sensing.

We report the spontaneous resolution of a massive detachment of Descemet's membrane 10 months after uneventful phacoemulsification. Diagnosis of the detachment was delayed because of severe corneal edema; thus, surgery was not performed. We propose that this complication of severe corneal edema after cataract surgery be considered and, given its excellent outcome, we recommend surgical treatment.

The presence of anatoxin-a (ANA) in Mediterranean region freshwaters has been reported only recently, and this work presents the first survey for ANA on a national scale in such waters. Fourteen reservoirs were sampled over a distance of 550 km from northeast to southwest Spain. Genera of cyanobacteria with ANA-producing members in other countries were present in all of the Spanish reservoirs, but this toxin was detected in only one reservoir. The maximum ANA concentration detected was 0.31 lg AE L )1 , and the most probable producer was Anabaena flos-aquae (Lyngb.) Bréb. ex Bornet et Flahault. These findings suggest that in spite of the abundant cyanobacterial populations, ANA may be of lower occurrence in the Spanish reservoirs investigated than in other European freshwaters, and different strains of potential ANA producers occur in different ecoregions.

A lo largo de varias décadas de investigaciones arqueológicas, la sierra de El Alto-Ancasti, en el extremo oriental de la provincia de Catamarca (Argentina), fue reconocida por albergar gran cantidad de abrigos pétreos con pinturas y grabados prehispánicos. Sin descuidar la importancia de estas cuevas y aleros, en este trabajo nos concentramos en caracterizar y contrastar dos paisajes diferentes y complementarios: uno asociado a los abrigos con arte rupestre, nucleados en el sector conocido como Cerro de Oyola, y otro aldeano y agrícola, dispuesto en las áreas más bajas adyacentes. En este marco, se describen los diferentes aspectos del registro arqueológico que conforman cada uno de estos espacios, como estructuras de vivienda, terrazas agrícolas, artefactos de molienda y ciertos contrastes en los conjuntos de arte rupestre detectados en cada lugar. Para finalizar se plantean algunas diferencias en los modos materiales de construir estos paisajes. que podrían corresponder a formas diversas, articuladas e interdependientes de habitarlos.