An Actin Network Dispatches Ciliary GPCRs into Extracellular Vesicles to Modulate Signaling

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Spatial ecology of jaguars,pumas, and ocelots: a review of the state of knowledge

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Varying demographic impacts of different fisheries on three Mediterranean seabird species

Fisheries have an enormous economic importance, but reconciling their socio‐economic features with the conservation and sustainability of marine ecosystems presents major challenges. Bycatch mortality from fisheries is clearly among the most serious global threats for marine ecosystems, affecting a wide range of top predators. Recent estimates report ca. 200,000 seabirds killed annually by bycatch in European waters. However, there is an urgent need to rigorously estimate actual mortality rates and quantify effects of bycatch on populations. The Mediterranean Sea is one of the most impacted regions. Here, we estimate for the first time both bycatch mortality rates and their population‐level effects on three endemic and vulnerable Mediterranean taxa: Scopoli's shearwater, Mediterranean shag, and Audouin's gull, that die in different types of fishing gears: longlines, gillnets and sport trolling, respectively. We use multi‐event capture–recapture modelling to estimate crucial demographic parameters, including the probabilities of dying in different fishing gears. We then build stochastic demography models to forecast the viability of the populations under different management scenarios. Longline bycatch was particularly severe for adults of Scopoli's shearwaters and Audouin's gulls (ca. 28% and 23% of total mortality, respectively) and also for immature gulls (ca. 90% of mortality). Gillnets had a lower impact, but were still responsible for ca. 9% of juvenile mortality on shags, whereas sport trolling only slightly influenced total mortality in gulls. Bycatch mortality has high population‐level impacts in all three species, with shearwaters having the highest extinction risk under current mortality rates. Different life‐history traits and compensatory demographic mechanisms between the three species are probably influencing the different bycatch impact: for shearwaters, urgent conservation actions are required to ensure the viability of their populations. Results will be very useful for guiding future seabird conservation policies and moving towards an ecosystem‐based approach to sustainable fisheries management.     

Organic versus conventional citrus. Impact assessment and variability analysis in the Comunitat Valenciana (Spain)

Purpose

Taking into account the large area of citrus in Spain and the impacts generated by agriculture, reducing the environmental impact of this crop represents an important goal. This study attempts to compare the environmental impact of two citrus cropping systems, organic and conventional, in the region of Valencia (Spain), and to assess the variability within both farming systems in order to highlight the influence of management practices on the environmental performance.

Methods

A survey was carried out on citrus farmers, 145 corresponding to organic production and 122 to conventional. Life cycle assessment (LCA) was used to estimate the environmental impacts of farms and the contribution of each production stage to impacts. Two functional units (FUs), mass- and area-based, were chosen. The variability and confidence intervals of the average impact results were assessed by means of a bootstrap technique. Finally, a k-means cluster analysis was performed to identify groups of farms with comparable impact levels.

Results and discussion

The mean impact values of the conventional farm sample were higher than those of the organic farms, when using 1 ha year^?1 as FU, whereas for the FU of 1 kg no differences were found for some impact categories. Most of the impact results were also observed to be highly variable. The distribution of the mean after the bootstrap confirmed both the variability of the impacts and the differences between the farming systems. The cluster analysis determined two groups via their impact categories. Cluster-1, which showed higher impacts, was made up of part of the conventional farms while cluster-2 included the remaining conventional farms and all the organic ones. No difference in yield was found between the conventional farms of both clusters.

Conclusions

Bootstrapped LCA offers the ability to assess the variability of the impacts, regardless of the sample size and the non-normal impact distributions. The cluster analysis shows that conventional farms can attain similar impacts than the organic ones, while maintaining the yield. FU selection is crucial, since a mass-based FU reduces the difference in the environmental performance between conventional and organic farms. To attain a more sustainable citrus farming, a careful selection of the management practices is needed.

     

Partition and metabolic fate of dietary glycerol in muscles and liver of juvenile tilapia

This study investigated the effect of dietary glycerol on the metabolism of juvenile tilapia (Oreochromis mossambicus) and to determine its metabolic fate. The experimental diets contained 0% (Group CON), 5% (Group G5) and 15% glycerol (Group G15) and were fed for 40 d to apparent satiation, three times a day. For the metabolism trials, six fish from each treatment were randomly chosen and tube-fed with five pellets labelled with ¹⁴C-glycerol [¹⁴C(U)] in order to evaluate the absorption, catabolism, retention and partition of glycerol in muscle and liver. Group G5 presented the highest ¹⁴C-glycerol retention and the lowest catabolism, with no significant differences between Groups CON and G15. In Group CON, the highest percentage of ¹⁴C was incorporated in muscle lipids; with no significant differences between Groups G5 and G15. Furthermore, no treatment effects were found for hepatic ¹⁴C-lipid and for ¹⁴C in hepatic and muscle non-lipid extract. In the non-lipid and non-protein fraction, the highest radioactivity was measured in livers of Group G5, however no significant differences were found for this fraction between Groups CON and G15 in liver and for all treatments in muscle. The results of the present study can have practical implications in diet formulations for tilapia and for other aquaculture species with similar feeding pattern since juvenile tilapia are able to metabolise dietary glycerol into lipids, protein and/or carbohydrates and to use it as energy source.     

A simple method to induce hypoxia-induced vascular endothelial growth factor-A (VEGF-A) expression in T24 human bladder cancer cells

Angiogenesis is an essential process for the establishment, development, and dissemination of several malignant tumors including bladder cancer. The hypoxic condition promotes the stabilization of hypoxia-inducible factor 1 alpha (HIF-1α), which translocates to the nucleus to mediate angiogenic factors including the vascular endothelial growth factor A (VEGF-A). AnaeroGen system was developed for microbiology area to create a low oxygen tension required to the growth of anaerobic bacteria. Here, we hypothesized the use of AnaeroGen system to induce hypoxia in T24 human bladder carcinoma cells, in order to promote the overexpression of VEGF-A. T24 cells were cultured in six-well plates containing McCoy medium. Exposures of T24 cells to hypoxia for 1, 8, 24, and 48 h were performed using the Oxoid AnaeroGen system, while T24 cells under normoxia were used as control. The expression of VEGF-A and HIF-1α was analyzed by real-time PCR. ELISA for HIF-1α was carried out. The VEGF-A expression increased significantly by Oxoid AnaeroGen-induced hypoxia in a time-depending manner, reaching the peak in 48 h of hypoxia. Although HIF-1α mRNA was not changed, HIF-1α protein was increased in the presence of hypoxia, reaching a peak at 8 h. These results demonstrated that the Oxoid AnaeroGen system is a simple method to expose T24 cells to hypoxia and efficiently to upregulate VEGF expression in T24 cells.     

A collection of enhancer trap insertional mutants for functional genomics in tomato

With the completion of genome sequencing projects, the next challenge is to close the gap between gene annotation and gene functional assignment. Genomic tools to identify gene functions are based on the analysis of phenotypic variations between a wild type and its mutant; hence, mutant collections are a valuable resource. In this sense, T‐DNA collections allow for an easy and straightforward identification of the tagged gene, serving as the basis of both forward and reverse genetic strategies. This study reports on the phenotypic and molecular characterization of an enhancer trap T‐DNA collection in tomato (Solanum lycopersicum L.), which has been produced by Agrobacterium‐mediated transformation using a binary vector bearing a minimal promoter fused to the uidA reporter gene. Two genes have been isolated from different T‐DNA mutants, one of these genes codes for a UTP‐glucose‐1‐phosphate uridylyltransferase involved in programmed cell death and leaf development, which means a novel gene function reported in tomato. Together, our results support that enhancer trapping is a powerful tool to identify novel genes and regulatory elements in tomato and that this T‐DNA mutant collection represents a highly valuable resource for functional analyses in this fleshy‐fruited model species.     

Continental-scale patterns of nutrient and fish effects on shallow lakes: introduction to a pan-European mesocosm experiment

1. Shallow lake ecosystems are normally dominated by submerged and emergent plants. Biological stabilising mechanisms help preserve this dominance. The systems may switch to dominance by phytoplankton, however, with loss of submerged plants. This process usually takes place against a background of increasing nutrient loadings but also requires additional switch mechanisms, which damage the plants or interfere with their stabilising mechanisms. 2. The extent to which the details or even major features of this general model may change with geographical location are not clear. Manipulation of the fish community (biomanipulation) has often been used to clear the water of algae and restore the aquatic plants in northerly locations, but it is again not clear whether this is equally appropriate at lower latitudes. 3. Eleven parallel experiments (collectively the International Mesocosm Experiment, IME) were carried out in six lakes in Finland, Sweden, England, the Netherlands and Spain in 1998 and 1999 to investigate the between‐year and large‐scale spatial variation in relationships between nutrient loading and zooplanktivorous fish on submerged plant and plankton communities in shallow lakes. 4. Comparability of experiments in different locations was achieved to a high degree. Cross‐laboratory comparisons of chemical analyses revealed some systematic differences between laboratories. These are unlikely to lead to major misinterpretations. 5. Nutrient addition, overall, had its greatest effect on water chemistry then substantial effects on phytoplankton and zooplankton. Fish addition had its major effect on zooplankton and did not systematically change the water chemistry. There was no trend in the relative importance of fish effects with latitude, but nutrient addition affected more variables with decreasing latitude. 6. The relative importance of top‐down and bottom‐up influences on the plankton differed in different locations and between years at the same location. The outcome of the experiments in different years was more predictable with decreasing latitude and this was attributed to more variable weather at higher latitudes that created more variable starting conditions for the experiments.