Establishing causal links between aquatic biodiversity and ecosystem functioning: status and research needs

Understanding how changes in biodiversity affects ecosystem functioning is imperative in allowing Ecosystem-Based Management (EBM), especially when addressing global change and environmental degradation. Research into the link between biodiversity and ecosystem functioning (BEF) has indeed increased considerably over the past decades. BEF research has focussed on terrestrial ecosystems and aquatic ecosystems have received considerably less attention. Due to differences in phylogenetic diversity, ecological processes and reported BEF relationships, however, it may at least be questionable whether BEF relationships are exchangeable between these ecosystems (i.e. terrestrial and aquatic). The aim of the present paper was therefore to pinpoint key areas and bottlenecks in establishing BEF relationships for aquatic ecosystems (freshwater, transitional, and marine). To this end, the available literature with special emphasis on the last 10 years was assessed to evaluate: i) reported mechanisms and shapes of aquatic BEF relationships; ii) to what extent BEF relations are interchangeable or ecosystem-specific; and iii) contemporary gaps and needs in aquatic BEF research. Based on our analysis, it may be concluded that despite considerable progress in BEF research over the past decades, several bottlenecks still need to be tackled, namely incorporating the multitude of functions supported by ecosystems, functional distinctiveness of rare species, multitrophic interactions and spatial-temporal scales, before BEF relationships can be used in ecosystem-based management.publishe

Avaliação do impacto de descargas em sistemas fluviais urbanos : o caso da ribeira de Couros

Os recursos hídricos, apesar de desempenharem um papel fulcral e insubstituível para o equilíbrio ecológico e para a manutenção da vida na Terra, são dos recursos naturais mais afetados pelas atividades antropogénicas. Nas últimas décadas, o uso sustentável da água e a preservação das suas origens tem merecido uma atenção crescente das entidades responsáveis, face à premente necessidade de se adotarem medidas adequadas ao efetivo controlo da qualidade da água dos sistemas aquáticos. O presente trabalho insere-se num projeto mais abrangente, relativo à Regularização e Requalificação da Ribeira de Couros (na bacia hidrográfica do rio Ave), que atravessa a zona urbana de Guimarães, constituindo uma fase preliminar da vertente associada à gestão da qualidade da água. O principal objetivo desta fase é o de monitorizar a evolução das concentrações de oxigénio dissolvido (OD) ao longo de um trecho inicial da ribeira de Couros, no sentido de calibrar e validar o modelo de qualidade da água da ribeira (em desenvolvimento), de modo a simular o balanço de oxigénio dissolvido ao longo desse trecho e a avaliar o impacto das descargas antrópicas nesse meio hídrico. Face à indisponibilidade de dados de qualidade da água, foi implementado um programa de monitorização através da realização de campanhas de amostragem semanais de modo a avaliar a evolução dos parâmetros de qualidade da água (OD, CBO, pH, temperatura e potencial oxi-redox) considerados mais relevantes para a avaliação do estado de oxigenação deste ecossistema aquático. Neste artigo apresenta-se uma síntese dos principais resultados obtidos ao longo dessas campanhas de monitorização, evidenciando aqueles que permitem identificar os trechos mais críticos no sentido de avaliar a sua correlação com a eventual presença de descargas de águas residuais e/ou pluviais não tratadas

Changes in life-history parameters of Daphnia longispina (Cladocera, Crustacea) as a function of water chemistry

Health, distribution and life-history of aquatic crustaceans strongly depend on water hardness. However hardness is commonly correlated with alkalinity, which highlights the need to assess the joint effects of both hardness and alkalinity. This study aims to test the hypothesis that water hardness and alkalinity affect the life-history parameters (growth, reproduction and population growth rate) of D. longispina . Following this, life table experiments were carried out in order to study the effects of high levels versus low levels of water hardness and alkalinity. Low levels of hardness and alkalinity caused a significant reduction in the growth of daphnids after a 7-days period, which augmented during the 21-day-test period reaching a 14.5% reduction compared to high hardness and alkalinity. Allied to the reduced growth, daphnids reared at low hardness and alkalinity showed delayed reproduction, increased body length at first reproduction, reduced fertility at first brood and, consequently, a 36.6% reduction in total fertility, compared to daphnids reared at high hardness and alkalinity. Accordingly, daphnids with the same size produced smaller broods at low hardness and alkalinity, reflecting a direct effect of water chemistry on daphnids reproduction. The impaired growth and reproduction at low hardness and alkalinity levels was likely a consequence of increased maintenance costs, and was not related to changes in the feeding activity. Population growth rate of daphnids reared at low hardness and alkalinity was 13.4% lower than that of daphnids reared at high hardness and alkalinity. Thus, despite D. longispina can survive at low hardness and alkalinity, their life-history parameters are significantly affected. This study raises concerns about the effects of decreasing hardness and alkalinity, which has been reported in Europe and North America, on populations of D. longispina and, thus, on the structure of aquatic ecosystems.

Behavioural responses of indigenous benthic invertebrates (Echinogammarus meridionalis, Hydropsyche pellucidula and Choroterpes picteti) to a pulse of Acid Mine Drainage: A laboratorial study

The drainage of abandoned mines leads to several ecological problems, particularly the acidification of surface freshwater systems and heavy metal contamination. In order to study the possibility of using the behavioural early warning responses of Portuguese indigenous benthic invertebrates to detect an acute short-term pulse of Acid Mine Drainage (AMD), experiments with the Multispecies Freshwater Biomonitor MFB(TM) were performed and locomotion and ventilation were measured as endpoints. AMD was collected from the "São Domingos" mine (Southeast Portugal) and the following species were selected: Echinogammarus meridionalis (Pinkster, 1973), Hydropsyche pellucidula (Curtis, 1834) and Choroterpes picteti (Eaton, 1870). For simulating the pulsed exposure, AMD was added to river water where invertebrates were collected and pH was lowered until reaching 3.5. The effects of H+ and heavy metals were discriminated using HCl positive controls. In addition to behaviour, mortality was registered. E. meridionalis was the most sensitive species in terms of mortality and behavioural endpoints, followed by C. picteti and H. pellucidula. E. meridionalis early warning responses consisted of increased locomotion with subsequent increase in ventilation, whereas for C. picteti only an increase in locomotion was observed. H. pellucidula showed no early warning responses. This work demonstrates the suitableness of using benthic invertebrates' behavioural early warning responses for detecting spikes of pollutants like AMD.http://www.sciencedirect.com/science/article/B6VB5-4SN92M3-3/1/d6f668cd09b5a2fc28906c7f4eb3dea

Gastrointestinal digestion of Sambucus nigra L. flower and berry bioactive molecules: in vitro and in vivo evaluation

Sambucus nigra L. is a flowering plant, which has been used for centuries as part of folk medicine, due to its bioactive properties. In this work the bioaccessibility of S. nigra (flower and berry) extracts after in vitro gastrointestinal digestion and their effect on toxicity and bioactive potential were studied. The extractions were performed with distilled water at 90 °C for 30 min. The obtained extracts were exposed to the INFOGEST harmonized in vitro digestion protocol. The chemical composition was analyzed before and after the digestion process, in terms of phenolics (TPC), flavonoids (TFC), and anthocyanins; additionally, phenolic compounds profile was determined by UPLC. The antioxidant activity was determined by FRAP, DPPH and ABTS methods. Cell viability and cellular reactive oxygen species (ROS) levels were assessed using normal cell line (L929) and cancerous cell lines (HeLa and HT29). The in vivo toxicity was measured by a simple model of Artemia salina. The chemical analysis revealed that berries evidence higher content of total extractives than the flower. When comparing the extracts before and after digestion there is an increase in the TPC on both extracts, while a significant decrease on the TFC. The compounds with the higher content were rutin, chlorogenic acid and rosmarinic acid in S. nigra flower extract, while in the S. nigra berry extract were rutin, resveratrol, ferulic and chorogenic acid. The effect of the non-digested and digested extracts was significantly different on the different cell lines. The IC50 of L929 cells was the highest, indicating low toxicity. The IC50 of HeLa and HT29 cells was lower, particularly the extract obtained from the flower upon the digestion. These results indicate that these natural compounds can be used as adjuvants in anticancer therapy. In the presence of an oxidant agent tbHP, only the berry extract was able to significantly reduce the formation ROS in L929 cell line, while on the HeLa cells all the extracts were able to reduce it. The in vivo assay demonstrated a dose-dependent effect for all extracts. The berry digested aqueous extract induced the lowest mortality rate in all concentrations evaluated. The promising results obtained on the chemical and biological evaluation of the extracts indicate that the natural compounds isolated from S. nigra by-products can be used as potential ingredients for functional food formulations, and/or as bio-therapeutic agents.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit, by program Marie Skłodowska-Curie grant (MSCA-RISE; FODIAC; 778388), and by the European Regional Development Fund (ERDF) through the Competitiveness factors Operational program – Norte 2020, COMPETE and by National Funds through the FCT - under the project AgriFood XXI (NORTE- 01-0145-FEDER000041).info:eu-repo/semantics/publishedVersio

Development and validation of a mathematical model to predict the complexity of FMR1 allele combinations

The polymorphic trinucleotide repetitive region in the FMR1 gene 5'UTR contains AGG interspersions, particularly in normal-sized alleles (CGG 200). The AGG interspersions have long been identified as one of the most important features of FMR1 repeat stability, being particularly important to determine expansion risk estimates in female premutation carriers. We sought to compute the combined AGG interspersion numbers and patterns, aiming to define FMR1 repetitive tract complexity combinations. A mathematical model, the first to compute this cumulative effect, was developed and validated using data from 131 young and healthy females. Plotting of their allelic complexity enabled the identification of two statistically distinct groups - equivalent and dissimilar allelic combinations. The outcome, a numerical parameter designated allelic score, depicts the repeat substructure of each allele, measuring the allelic complexity of the FMR1 gene including the AGGs burden, thus allowing new behavioral scrutiny of normal-sized alleles in females.publishe

Creation of a vehicular delay-tolerant network prototype

Vehicular Delay-Tolerant Network (VDTN) is a new disruptive network architecture where vehicles act as the communication infrastructure. VDTN follows a layered architecture based on control and data planes separation, and positioning the bundle layer under the network layer. VDTN furnishes low-cost asynchronous communications coping with intermittent and sparse connectivity, variable delays and even no end-to-end connection. This paper presents a VDTN prototype (testbed) proposal, which implements and validates the VDTN layered architecture considering the proposed out-of-band signaling. The main goals of the prototype are emulation, demonstration, performance evaluation, and diagnose of protocol stacks and services, proving the applicability of VDTNs over a wide range of environments.Part of this work has been supported by the Instituto de Telecomunicações, Next Generation Networks and Applications Group (NetGNA), Covilhã Delegation, Portugal in the framework of the VDTN@Lab Project, and by the Euro-NF Network of Excellence from the Seventh Framework Programme of EU

Measles outbreak after 12 years without endemic transmission, Portugal, February to May 2017

We report a measles outbreak in two Portuguese health regions (Algarve and Lisbon and the Tagus Valley) since February 2017, and which by 31 May resulted in 28 confirmed cases, of which 16 were unvaccinated. Thirteen cases were healthcare workers. One unvaccinated teenager died. Genotype B3 was identified in 14 cases from both regions. This outbreak occurs after 12 years without endemic measles transmission, and in a context of high measles vaccination coverage and immunity.info:eu-repo/semantics/publishedVersio

Ranging behaviour of translocated roe deer in a Mediterranean habitat: seasonal and altitudinal influences on home range size and patterns of range use

In this study we investigated the causes of seasonal variation in the home ranges of roe deer reintroduced to the Gardunha Mountains (Portugal). From May 2002 to April 2003, 1 year after the animals had been released, we collected data using radio-tracking techniques for five monitored animals (two males and three females). We found differences in the size of home ranges between seasons, with home ranges larger in summer than winter (minimum convex polygon peeled to 95%: summer 409.64 +/- 98.20 ha, winter 116.20 +/- 17.90 ha). This is contrary to evidence from central and northern Europe, where home ranges are typically larger in winter than summer. Moreover, two of the sampled females and one of the males tended to use higher elevations in summer. Comparisons between Mediterranean populations and those in central and northern Europe showed that Mediterranean populations in the winter easily fulfil their needs within a small area, whereas in the hot dry summer a larger area is needed. Furthermore, individuals prefer a higher, cooler mountainous habitat in summer, which is likely to be a means of avoiding warmer temperatures