Mapping the impact of alien species on marine ecosystems: the Mediterranean Sea case study

Aim. To develop a standardized, quantitative method for mapping cumulative impacts of invasive alien species on marine ecosystems. Location. The methodology is applied in the Mediterranean Sea but is widely applicable. Methods. A conservative additive model was developed to account for the Cumulative IMPacts of invasive ALien species (CIMPAL) on marine ecosystems. According to this model, cumulative impact scores are estimated on the basis of the distributions of invasive species and ecosystems, and both the reported magnitude of ecological impacts and the strength of such evidence. In the Mediterranean Sea case study, the magnitude of impact was estimated for every combination of 60 invasive species and 13 habitats, for every 10 9 10 km cell of the basin. Invasive species were ranked based on their contribution to the cumulative impact score across the Mediterranean. Results. The CIMPAL index showed strong spatial heterogeneity. Spatial patterns varied depending on the pathway of initial introduction of the invasive species in the Mediterranean Sea. Species introduced by shipping gave the highest impact scores and impacted a much larger area than those introduced by aquaculture and the Suez Canal. Overall, invasive macroalgae had the highest impact among all taxonomic groups. These results represent the current best estimate of the spatial variation in impacts of invasive alien species on ecosystems, in the Mediterranean Sea. Main Conclusions. A framework for mapping cumulative impacts of invasive alien species was developed. The application of this framework in the Mediterranean Sea provided a baseline that can be built upon with future improved information. Such analysis allows the identification of hotspots of highly impacted areas, and prioritization of sites, pathways and species for management actions

Assessing anti-malarial drug effects ex vivo using the haemozoin detection assay

© 2015 Rebelo et al.; licensee BioMed Central. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0) which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.Background: In vitro sensitivity assays are crucial to detect and monitor drug resistance. Plasmodium falciparum has developed resistance to almost all anti-malarial drugs. Although different in vitro drug assays are available, some of their inherent characteristics limit their application, especially in the field. A recently developed approach based on the flow cytometric detection of haemozoin (Hz) allowed reagent-free monitoring of parasite maturation and detection of drug effects in culture-adapted parasites. In this study, the set-up, performance and usefulness of this novel assay were investigated under field conditions in Gabon. Methods: An existing flow cytometer (Cyflow Blue) was modified on site to detect light depolarization caused by Hz. Blood from malaria patients was incubated for 72 hrs with increasing concentrations of chloroquine, artesunate and artemisinin. The percentage of depolarizing red blood cells (RBC) was used as maturation indicator and measured at 24, 48 and 72 hrs of incubation to determine parasite growth and drug effects. Results: The flow cytometer was easily adapted on site to detect light depolarization caused by Hz. Analysis of ex vivo cultures of parasites, obtained from blood samples of malaria patients, showed four different growth profiles. In 39/46 samples, 50% inhibitory concentrations (IC50) were successfully determined. IC50 values for chloroquine were higher than 200 nM in 70% of the samples, indicating the presence of chloroquine-resistant parasites. For artesunate and artemisinin, IC50 values ranged from 0.9 to 60 nM and from 2.2 nM to 124 nM, respectively, indicating fully sensitive parasites. Conclusion: Flow cytometric detection of Hz allowed the detection of drug effects in blood samples from malaria patients, without using additional reagents or complex protocols. Adjustment of the initial parasitaemia was not required, which greatly simplifies the protocol, although it may lead to different IC50 values. Further investigation of set-up conditions of the Hz assay, as well as future studies in various settings should be performed to further determine the usefulness of this assay as a tool for rapid resistance testing in malaria-endemic countries.This work was supported by the Luso-American Foundation (FLAD-LACR grant: B-A.V-109-09/07). MR acknowledges Fundação para a Ciência e a Tecnologia for doctoral grant (SFRH/BD/84530/2012) and Fundação Calouste Gulbenkian for the Award CAML/Gulbenkian for Travel ACGT fellowship.info:eu-repo/semantics/publishedVersio

2 years-long monitoring of <i>Codium elisabethae</i> population dynamics in the Azorian reef ecosystem (Faial Island) with seabed imagery

In the Site of Community Interest (Natura, 2000) of Monte-da-Guia (Faial, Azores), two sites were delimited in order to investigate particularly the links between habitat characteristics, population structure, distribution and dynamics of the green alga Codium elisabethae. The first site is a large protected rocky seafloor of an ancient volcano crater (20m deep) and classified as no-go reserve. It shows very high density stands of Codium elisabethae (up to 105 ind.m-2), representing the main vegetal biomass. At similar depth but distant of about two kilometers, the second site is in a more exposed area, where a sparse population (about 13 ind.m-2) occupies rocky tables and boulders emerging from shallow sandy deposits. These contrasting densities reflect different population dynamic equilibrium resulting from the particular environmental pressures of each site. A two year population survey started in August 2003, aiming principally at building submarine image mosaics of each site on a seasonal basis. Further, a computer assisted detection is run on the images to derive valuable information about the studied macroalgae. This technique allows to study a comparatively large zone regarding to the diving time invested so as to integrate spatial patchiness and to focus on the temporal evolution of well identified individuals. The imagery methodology was validated with in situ measurements, confirming the adequacy of the 1cm precision size histograms produced, when considering individuals larger than 5cm diameter. Seasonal fluctuations of growth rate (from 0.5 to 3cm.month-1) and primary production (from 1 to 15kg.m-².month-1) could be described. For both sites studied, density, biomass and cover rate seemed affected by a seasonal variation with reduction starting in end summer early autumn. In both sites, the reduction was sharp in the fall 2003 and population density didn’t recover completely in spring and summer 2004. During the following year, population of the protected site could maintain density and biomass, while population of the exposed site dropped continuously all year. Last processing step will search to relate statistically these different population evolutions to the benthic environmental constraints measured in both sites during the year 2004-2005 (temperature, currents, turbidity, photosynthetic active radiation, nutrients). Differences in hydrodynamic exposure of both sites could be part of the answer, but observed differences in the reproduction intensity of these two populations is an important factor, and remains unexplained

First in situ observations of soft bottom megafauna from the Cascais Canyon head

We report the first in situ observations of soft bottom megafauna from the Cascais Canyon head. Observations were collected opportunistically during three technical dives with the ROV Luso between 460-805 m at two locations distanced 1,230 m. The habitats were clas-sified as upper bathyal fine mud. The soft bottom fauna was dominated by burrows of Nephrops norvegicus reaching up to 2.9 burrows/m2, a common habitat along the Portu-guese continental margin. To our knowledge, densities are the highest ever reported for depths below 300 m. The ichthyofauna at the upper Cascais Canyon is a mixture of lower shelf and upper bathyal species, including Phycis blennoides, Scyliorhynus canicula, Coe-lorhynchus labiatus/occa and Chimaera monstrosa. Bait release attracted Myxine glutinosa. Surveys in other geological settings of the Cascays Canyon are required to understand more comprehensively the diversity of its sessile and vagile biodiversity

Effect of peroxides on spermine transport in rat brain and liver mitochondria.

The polyamine spermine is transported into the matrix of various types of mitochondria by a specific uniporter system identified as a protein channel. This mechanism is regulated by the membrane potential; other regulatory effectors are unknown. This study analyzes the transport of spermine in the presence of peroxides in both isolated rat liver and brain mitochondria, in order to evaluate the involvement of the redox state in this mechanism, and to compare its effect in both types of mitochondria. In liver mitochondria peroxides are able to inhibit spermine transport. This effect is indicative of redox regulation by the transporter, probably due to the presence of critical thiol groups along the transport pathway, or in close association with it, with different accessibility for the peroxides and performing different functions. In brain mitochondria, peroxides have several effects, supporting the hypothesis of a different regulation of spermine transport. The fact that peroxovanadate can inhibit tyrosine phosphatases in brain mitochondria suggests that mitochondrial spermine transport is regulated by tyrosine phosphorylation in this organ. In this regard, the evaluation of spermine transport in the presence of Src inhibitors suggests the involvement of Src family kinases in this process. It is possible that phosphorylation sites for Src kinases are present in the channel pathway and have an inhibitory effect on spermine transport under regulation by Src kinases. The results of this study suggest that the activity of the spermine transporter probably depends on the redox and/or tyrosine phosphorylation state of mitochondria, and that its regulation may be different in distinct organs

O conhecimento matemático dos estudantes no início da Licenciatura em Educação Básica: um projeto envolvendo três Escolas superiores de educação

O novo modelo de formação inicial (Decreto-Lei 43/2007) exige que os futuros professores do 1.º e 2.º ciclos do ensino básico e os futuros educadores de infância façam pelo menos 30 ECTS de formação em Matemática na Licenciatura em Educação Básica (LEB), mas a forma e o conteúdo desta formação é da responsabilidade de cada instituição, que define as unidades curriculares, o seu conteúdo e a forma como são lecionadas. Sabe-se que, para além do conteúdo, a forma como o professor aprende tem uma forte influência na forma como vai ensinar. Assim, todos estes aspetos precisam de ser discutidos, tendo por base a investigação já realizada em Portugal e noutros países. Partindo da assunção de que o conhecimento do professor constitui um fator decisivo na interpretação e implementação do currículo e da necessidade de uma discussão alargada de qual deverá ser o conteúdo da formação em Matemática na LEB, as Escolas Superiores de Educação de Lisboa, de Viana do Castelo e de Viseu iniciaram um projeto de investigação que tem como principal objetivo compreender de que modo a formação inicial contribui para o desenvolvimento do conhecimento do professor em Matemática e em Ensino da Matemática e como pode este ser promovido. Uma das questões que o projeto visa investigar é que conhecimento de conteúdo matemático têm os estudantes quando iniciam o curso da LEB. Para caracterizar o conhecimento matemático dos estudantes da LEB, à entrada no curso, foi elaborado um teste diagnóstico, que foi aplicado nas três Escolas Superiores de Educação, em outubro de 2011, a todos os alunos a iniciar o 1.º ano, num total de 268: 143 em Lisboa, 51 em Viseu e 74 em Viana do Castelo. Neste artigo é apresentada uma análise dos principais resultados deste teste bem como as questões e dilemas que aqueles resultados nos colocam

Polyketone polymer: a new support for direct enzyme immobilization.

Polyketone polymer -[-CO-CH2CH2-](n)-, obtained by copolymerization of ethene and carbon monoxide, is utilized for immobilization of three different enzymes, one peroxidase from horseradish (HRP) and two amine oxidases, from bovine serum (BSAO) and lentil seedlings (LSAO). The easy immobilization procedure is carried out in diluted buffer, at pH 7.0 and 3 degrees C, gently mixing the proteins with the polymer. No bifunctional reagents and spacer arms are required for the immobilization, which occurs exclusively via a large number of hydrogen bonds between the carbonyl groups of the polymer and the -NH groups of the polypeptidic chain. Experiments demonstrate a high linking capacity of polymer for BSAO and an extraordinary strong linkage for LSAO. Moreover, activity measurements demonstrate that immobilized LSAO totally retains the catalytic characteristics of the free enzyme, where only a limited increase of K-M value is observed. Finally, the HRP-activated polymer is successfully used as active packed bed of an enzymatic reactor for continuous flow conversion and flow injection analysis of hydrogen peroxide containing solutions. (c) 2006 Elsevier B.V. All rights reserved

Modulation of enhancer looping and differential gene targeting by Epstein-Barr virus transcription factors directs cellular reprogramming

Epstein-Barr virus (EBV) epigenetically reprogrammes B-lymphocytes to drive immortalization and facilitate viral persistence. Host-cell transcription is perturbed principally through the actions of EBV EBNA 2, 3A, 3B and 3C, with cellular genes deregulated by specific combinations of these EBNAs through unknown mechanisms. Comparing human genome binding by these viral transcription factors, we discovered that 25% of binding sites were shared by EBNA 2 and the EBNA 3s and were located predominantly in enhancers. Moreover, 80% of potential EBNA 3A, 3B or 3C target genes were also targeted by EBNA 2, implicating extensive interplay between EBNA 2 and 3 proteins in cellular reprogramming. Investigating shared enhancer sites neighbouring two new targets (WEE1 and CTBP2) we discovered that EBNA 3 proteins repress transcription by modulating enhancer-promoter loop formation to establish repressive chromatin hubs or prevent assembly of active hubs. Re-ChIP analysis revealed that EBNA 2 and 3 proteins do not bind simultaneously at shared sites but compete for binding thereby modulating enhancer-promoter interactions. At an EBNA 3-only intergenic enhancer site between ADAM28 and ADAMDEC1 EBNA 3C was also able to independently direct epigenetic repression of both genes through enhancer-promoter looping. Significantly, studying shared or unique EBNA 3 binding sites at WEE1, CTBP2, ITGAL (LFA-1 alpha chain), BCL2L11 (Bim) and the ADAMs, we also discovered that different sets of EBNA 3 proteins bind regulatory elements in a gene and cell-type specific manner. Binding profiles correlated with the effects of individual EBNA 3 proteins on the expression of these genes, providing a molecular basis for the targeting of different sets of cellular genes by the EBNA 3s. Our results therefore highlight the influence of the genomic and cellular context in determining the specificity of gene deregulation by EBV and provide a paradigm for host-cell reprogramming through modulation of enhancer-promoter interactions by viral transcription factors