No abstract

Evapotranspiration has been poorly characterized in the Altiplano, and the legal dispute over the status and use of the waters of the Silala River provided an opportunity for improving knowledge of this hydrological process, in a remote area with a lack of hydrometeorological data. Actual evapotranspiration (ETa) measurements using eddy covariance (EC) were performed in the riparian wetland (EC1) and over the alluvial deposits (EC2) of the Silala River basin, and in the Putana River wetland (EC3), with similar characteristics to the Silala River headwaters. The portable chamber method was used to characterize soil and plant evaporation near EC2. Satellite‐derived ETa estimates were evaluated with the in‐situ data, and used to investigate spatiotemporal dynamics of the wetland vegetation cover. At EC1 and EC3, annual ETa values were 703 and 841 mm, respectively; and satellite‐derived ETa showed differences of 5% and −35% from these values. ETa exhibited strong seasonal variations at EC1 and EC3, and was sensitive to precipitation at EC2. ETa did not follow the temporal evolution of the reference evapotranspiration at EC2, suggesting that lateral subsurface flow supports ETa in dry periods. Portable chamber measurements revealed that bare soil evaporation is the main component of ETa in the alluvial deposits. ETa data collected within the basin, as described in other papers of this special issue, allowed validation of a hydrological model used to estimate the basin's groundwater recharge, and estimation of the surface flow increase due to river channelization, which were important scientific evidence provided in the legal dispute.This article is categorized under: Science of Water > Hydrological Processes Science of Water > Methods

In this paper we optimize a flow cytometric method for evaluating the phagocytic activity of leucocytes in gilthead seabream (Sparus aurata L.) and characterize the phagocytic cells observed. Optimal conditions were established for the fluorescein-labelling and analysis of the bacterium Vibrio anguillarum by flow cytometry. Head-kidney leucocytes were incubated with the heat-killed fluorescein isothiocyanate (FITC)-labelled bacteria for different periods, during which the kinetics of phagocytosis was studied. Attached and interiorized bacteria were distinguished. Although phagocytic ability reached a maximum after 60 min, phagocytic capacity reached its maximum at 20 min. The amount of ingested bacteria per phagocyte was estimated from the mean fluorescence of the leucocytes. Cytochalasin B or colchicine was used to inhibit phagocytosis. Monocyte-macrophages and acidophilic granulocytes showed phagocytic activity as demonstrated by transmission electron microscopy. In conclusion, the technique presented allows the screening of thousands of cells, and individual cell evaluation, by quantifying interiorized particles in fish phagocytes. Our ultrastructural results demonstrate that V. anguillarum is actively phagocytized by seabream macrophages and acidophilic granulocytes.

AbstractCandida auris has emerged globally as a multidrug-resistant yeast that can spread via nosocomial transmission. An initial phylogenetic study of isolates from Japan, India, Pakistan, South Africa, and Venezuela revealed four populations (Clades I, II, III, and IV) corresponding to these geographic regions. Since this description, C. auris has been reported in over 30 additional countries. To trace this global emergence, we compared the genomes of 304 C. auris isolates from 19 countries on six continents. We found that four predominant clades persist across wide geographic locations. We observed phylogeographic mixing in most clades; Clade IV, with isolates mainly from South America, demonstrated the strongest phylogeographic substructure. C. auris isolates from two clades with opposite mating types were detected contemporaneously in a single healthcare facility in Kenya. We estimated a Bayesian molecular clock phylogeny and dated the origin of each clade within the last 339 years; outbreak-causing clusters from Clades I, III, and IV originated 34-35 years ago. We observed high rates of antifungal resistance in Clade I, including four isolates resistant to all three major classes of antifungals. Mutations that contribute to resistance varied between the clades, with Y132F in ERG11 as the most widespread mutation associated with azole resistance and S639P in FKS1 for echinocandin resistance. Copy number variants in ERG11 predominantly appeared in Clade III and were associated with fluconazole resistance. These results provide a global context for the phylogeography, population structure, and mechanisms associated with antifungal resistance in C. auris.ImportanceIn less than a decade, C. auris has emerged in healthcare settings worldwide; this species is capable of colonizing skin and causing outbreaks of invasive candidiasis. In contrast to other Candida species, C. auris is unique in its ability to spread via nosocomial transmission and its high rates of drug resistance. As part of the public health response, whole-genome sequencing has played a major role in characterizing transmission dynamics and detecting new C. auris introductions. Through a global collaboration, we assessed genome evolution of isolates of C. auris from 19 countries. Here, we described estimated timing of the expansion of each C. auris clade and of fluconazole resistance, characterized discrete phylogeographic population structure of each clade, and compared genome data to sensitivity measurements to describe how antifungal resistance mechanisms vary across the population. These efforts are critical for a sustained, robust public health response that effectively utilizes molecular epidemiology.