1,351 research outputs found
Feeding diversity index as complementary information in the assessment of ecological quality status
The feeding diversity of macroinvertebrates from the estuary of Mondego was estimated
with Shannon–Wiener complementary evenness following the methodology presented in Gamito and Furtado (2009. Ecological Indicators, 9: 1009-1019). Results were compared with those from BAT (Benthic Assessment Tool; Teixeira et al., 2009. Marine Pollution Bulletin, 58: 1477-1786) applied to the same data set, obtained from sampling carried out in 14 estuarine subtidal stations in Spring of 1990, 1992, 1998, 2000 and 2002. The BAT is a multimetric methodology based on three indices, the Shannon-Wiener and Margalef
diversity indices, applied in conjunction with AMBI (Marine Biotic Index). To determinate the feeding diversity, each invertebrate was assigned to a feeding group. Six trophic groups were considered: surface deposit feeders, subsurface deposit feeders, herbivores or grazers, suspension feeders and suspension/deposit feeders. The carnivorous, omnivorous and scavengers were all grouped together, forming the sixth group. The results obtained with both tools pointed out, in general, to the same tendencies. However, in few occasions the feeding diversity pointed out to a high or a bad ecological quality condition whereas the BAT indicated a moderate condition. Occasionally, in stations with average species richness, all individuals were assigned to only one to three 2
feeding groups, and the feeding diversity was low. Even if these taxa were included in the first two or three AMBI sensitive groups, with their presence indicating a possible good ecological condition, they all perform the same ecological function, for example, they are all omnivorous. In these cases the trophic functioning of the system is reduced and the lower trophic levels are missing, such as the suspension-feeders and the decomposers or deposit-feeders. On the contrary, a highly diverse trophic assemblage might be found, but composed of taxa assigned to AMBI ecological groups of species indifferent or tolerant to organic enrichment, and of second-order opportunistic species, indicating a moderate
ecological condition, while the feeding diversity will be high. The feeding diversity is, therefore, useful as a complementary information index, measuring other aspects of the community organization, which are not required for ecological quality assessment by the WFD, and so not included in metrics such as BAT
The importance of habitat-type for defining the reference conditions and the ecological quality status based on benthic invertebrates: the Ria Formosa coastal lagoon (Southern Portugal) case study
Coastal lagoons are complex systems, with considerable habitat heterogeneity and often
subject to high temporal dynamics, which constitutes a great challenge for ecological
assessment programs. For defining reference conditions for benthic invertebrates, under the EU Water Framework Directive objectives, historical data from the Ria Formosa leaky lagoon (wet surface area of about 105 km2) located in Southern Portugal was used. The influence of habitat features, such as channel depth, sediment type and seagrass cover, on the expression of these biological communities was inferred by analysing subtidal data collected at stations with
different environmental characteristics. Such heterogeneity effect was analysed at the
community compositional and structural levels, and also for three indices included in a multimetric Benthic Assessment Tool (BAT). This tool for the assessment of ecological status includes the Margalef index, Shannon-Wiener diversity index, and AZTI’s Marine Biotic Index (AMBI). Significant variations associated with environmental features were reflected on specific reference conditions at four habitats in the lagoon. After habitat calibration, the Benthic Assessment Tool (BAT) revealed that, in general and for the period of time covered by this historical data set, the status of the lagoon corresponded to a good ecological condition, which is mainly due to its high water renewal rate. Such classification is in accordance with the majority of studies at the lagoon. However, at punctual sites with human induced high water residence times, significantly lower BAT values were registered. Such community degradation
can be associated with physical stress due to salinity increase and to a degradation of water quality, with occurrence of occasional dystrophic crisis, triggered by low water renewal. Habitat 2 differentiation was a crucial step for a correct evaluation of the ecological condition of invertebrate communities across the lagoonal system
Histopathological and immunohistochemical differentiation of epithelial alterations in vocal nodule comparing to polyps and to laryngeal edema
AIM: To evaluate by histological and immunohistochemical methods the epithelial lesions in vocal nodule and correlate with polyp, laryngeal edema and vocal folds without macroscopic lesions. STUDY DESIGN: Chart review. MATERIAL AND METHOD: In a retrospective analysis of medical records, twenty-six patients, who underwent microsurgical excision of laryngeal inflammatory lesions (nodules, polyps and laryngeal edema), were identified. Vocal folds without macroscopic lesions were obtained from autopsy. To evaluate epithelial lesions, specimens were stained with H&E, PAS, and with antibodies against laminin and collagen type IV. These specimens were analyzed by light microscopy. RESULTS: Lesions diagnosed as nodules showed more collagen type IV and laminin deposition when compared to polyps (p=0,034 and p=0,036, respectively) and to vocal folds without macroscopic lesions (p=0,019 and p=0,021, respectively). Nodules showed basement membranes thicker than polyps on PAS stain (p=0,102). Laryngeal edema could not be differentiated from nodules, polyps or vocal folds without macroscopic lesions by PAS, laminin or collagen type IV stain (p>0,10). CONCLUSION: By histological and immunohistochemical techniques to evaluate epithelium of laryngeal inflammatory lesions we conclude that vocal fold nodule differentiate from polyps on the three techniques used to stain basement membrane (PAS, laminin, collagen IV) and from vocal folds without macroscopic lesions on two techniques used (laminin, collagen IV). Laryngeal edema cannot be differentiated from the others laryngeal lesions, neither from vocal folds without macroscopic lesions, when the techniques before described are used.OBJETIVO: Avaliar, por meio de técnicas histológicas e imunoistoquímicas, o epitélio nos nódulos vocais em relação aos pólipos, ao edema de laringe e às pregas vocais sem lesões macroscópicas. FORMA DE ESTUDO: Clínico retrospectivo. MATERIAL E MÉTODO: Por meio de levantamento de prontuário, foram identificados vinte e seis pacientes com lesões laríngeas inflamatórias (nódulos, pólipos e edema de laringe), que haviam sido submetidos à cirurgia. Pregas vocais sem alterações macroscópicas foram obtidas a partir de autópsia de cadáveres. Para análise do epitélio, foram realizadas colorações pela técnica da hematoxilina-eosina e do ácido periódico de Schiff e técnicas de imunoistoquímica com anticorpos dirigidos contra laminina e colágeno IV. A leitura das lâminas foi realizada por meio de microscopia óptica. RESULTADOS: Houve maior imunoexpressão de laminina e colágeno IV nos nódulos quando comparados aos pólipos (p=0,034 e p=0, 036, respectivamente), assim como quando comparados às pregas vocais sem lesões macroscópicas (p=0,019 e p=0, 021, respectivamente). Nódulos tendem a apresentar maior espessura da membrana basal, quando utilizamos coloração pela técnica do PAS, em relação aos pólipos (p=0,102). O edema de laringe não se diferenciou das demais nas técnicas utilizadas (p> 0,10). CONCLUSÕES: O Nódulo Vocal diferencia-se dos pólipos, nas três técnicas utilizadas para detecção da membrana basal (PAS, laminina, colágeno IV), e das pregas vocais sem lesões macroscópicas em duas das técnicas utilizadas (laminina e colágeno IV). Edema de laringe não se diferencia das demais lesões, nem de pregas vocais sem lesões macroscópicas, quando utilizadas as técnicas anteriormente descritas, para estudo da membrana basal.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de Otorrinolaringologia e Distúrbios da Comunicação HumanaUniversidade de São Paulo Faculdade de OdontologiaUNIFESP, EPM, Depto. de Otorrinolaringologia e Distúrbios da Comunicação HumanaSciEL
Assessment of the presence of Hepatitis E virus in surface water and drinking water in Portugal
© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).Hepatitis E virus (HEV) is a non-enveloped single-stranded positive-sense RNA virus, belonging to the Hepeviridae family, resistant to environmental conditions, and transmitted by the consumption of contaminated water. This virus is responsible for both sporadic and epidemic outbreaks, leading to thousands of infections per year in several countries, and is thus considered an emerging disease in Europe and Asia. This study refers to a survey in Portugal during 2019, targeting the detection and eventual quantification of enteric viruses in samples from surface and drinking water. Samples positive for HEV RNA were recurrently found by reverse transcription quantitative PCR (RT-qPCR), in both types of matrix. The infectivity of these samples was evaluated in cultured Vero E6 cells and RNA from putative viruses produced in cultures evidencing cytopathic effects and was subjected to RT-qPCR targeting HEV genomic RNA. Our results evidenced the existence of samples positive either for HEV RNA (77.8% in surface water and 66.7% in drinking water) or for infectious HEV (23.0% in surface water and 27.7% in drinking water). These results highlight the need for effective virological control of water for human consumption and activities.This research was funded by Empresa Portuguesa das Águas Livres (EPAL) and Foundation for Science and Technology (FCT) Portugal through a Ph.D. grant to D. Salvador (PDE/BDE/114582/2016) and FCT/MCTES projects UIDP/50017/2020+UIDB/50017/2020 and UIDB/04295/2020 through national funds.info:eu-repo/semantics/publishedVersio
Electronic doping of graphene by deposited transition metal atoms
We perform a phenomenological analysis of the problem of the electronic
doping of a graphene sheet by deposited transition metal atoms, which aggregate
in clusters. The sample is placed in a capacitor device such that the
electronic doping of graphene can be varied by the application of a gate
voltage and such that transport measurements can be performed via the
application of a (much smaller) voltage along the graphene sample, as reported
in the work of Pi et al. [Phys. Rev. B 80, 075406 (2009)]. The analysis allows
us to explain the thermodynamic properties of the device, such as the level of
doping of graphene and the ionisation potential of the metal clusters in terms
of the chemical interaction between graphene and the clusters. We are also
able, by modelling the metallic clusters as perfect conducting spheres, to
determine the scattering potential due to these clusters on the electronic
carriers of graphene and hence the contribution of these clusters to the
resistivity of the sample. The model presented is able to explain the
measurements performed by Pi et al. on Pt-covered graphene samples at the
lowest metallic coverages measured and we also present a theoretical argument
based on the above model that explains why significant deviations from such a
theory are observed at higher levels of coverage.Comment: 16 pages, 10 figure
Genetic population structure and connectivity of Azorean limpets
Ocean Science Meeting. Hawaii Convention Center, Honolulu, Hawaii, USA, 23-28 de Fevereiro.There is growing consensus that anthropogenic activities significantly rarefy the structure and functioning of marine ecosystems. Oceanic islands such as the Azores (NE Atlantic) constitute unique habitats with fragile communities, which are highly susceptible to degradation and ecosystem disruption. . Patellid limpets have traditionally been collected as a food resource and in 1988 the limpet fishery in São Miguel Island collapsed, and after a one-year ban throughout the archipelago, the stocks were allowed to recover, avoiding catastrophic overexploitation effects. In 1993, legislation was passed to protect this resource, i.e. limpet no-take areas were created, seasonal harvesting restrictions were applied and minimum legal catch sizes were established. However, a recent survey has shown that limpet populations still show clear signs of overexploitation and some populations are virtually extinct in some islands. Here we have developed new multiplexed and described microsatellite markers for the species Patella aspera and P. candei and have examined their genetic diversity, gene flow and population connectivity in the Azores Archipelago. Overall, such information is a fundamental asset to inform conservation strategies and to promote the sustainable exploitation of macaronesian limpets.FC
Determinação experimental da retenção do parafuso ortopédico em cortex ósseo
Cylindrical specimens of bone measuring 15 mm in diameter were obtained from the lateral cortical layer of 10 pairs of femurs and tibias. A central hole 3.2 mm in diameter was drilled in each specimen. The hole was tapped, and a 4.5 mm cortical bone screw was inserted from the outer surface. The montage was submitted to push-out testing up to a complete strip of the bone threads. The cortical thickness and rupture load were measured, and the shear stress was calculated. The results were grouped according to the bone segment from which the specimen was obtained. The results showed that bone cortex screw holding power is dependent on the bone site. Additionally, the diaphyseal cortical bone tissue is both quantitatively and qualitatively more resistant to screw extraction than the metaphyseal tissue.Foram retirados corpos de prova cilíndricos de 15 mm de diâmetro da camada cortical da face lateral de 10 pares de fêmures e tíbias oriundos de peças anatômicas. No centro de cada um destes foi feito um orifício de 3,2 mm e nele inserido, a partir da superfície externa, um parafuso cortical de 4,5 mm de diâmetro após rosqueamento com macho. Este conjunto foi submetido a um ensaio mecânico no qual o parafuso foi extraído. A espessura da camada cortical e a carga de ruptura foram medidas e a tensão de cisalhamento foi calculada. Os resultados foram agrupados de acordo com o segmento do osso de onde provinham. Os ensaios mostraram que a retenção cortical do parafuso varia ao longo do osso e que o tecido ósseo da córtex diafisária é tanto quantitativamente quanto qualitativamente mais resistente à extração do parafuso que o tecido metafisário
The effects of the invasive seaweed asparagopsis armata on native rock pool communities: evidences from experimental exclusion
Biological invasions represent a threat to ecosystems, through competition and habitat destruction, which may result in significant changes of the invaded community. Asparagopsis armata Harvey 1855 is a red macroalgae (Rodophyta) globally recognized as an invasive species. It is found from the intertidal to shallow subtidal areas, on rock or epiphytic, forming natural vegetation belts on exposed coasts. This study evaluated the variations on native intertidal seaweed and macroinvertebrate assemblages inhabiting rock pools with and without the presence of the invasive macroalgae A. armata. To achieve this, manipulation experiments on Atlantic (Portugal) rock pools were done. Three rock pools were maintained without A. armata by manual removal of macroalgae, and three others were not experimentally manipulated during the study period and A. armata was freely present. In this study the variations between different rock pools were assessed. Results showed different patterns in the macroalgae composition of assemblages but not for the macrobenthic communities. Ellisolandia elongata (J. Ellis & Solander) K.R. Hind & G.W. Saunders 2013 was the main algal species affected by the invasion of A. armata. Invaded pools tended to show less macroalgal species richness, showing a more constant and conservative structure, with lower variation of its taxonomic composition than the pools not containing A. armata, where the variability between samples was always higher. Despite the importance of the achieved results, further data based on observation of long-term series are needed, in order to further understand more severe effects of the invader A. armata on native macroalgal assemblage.info:eu-repo/semantics/publishedVersio
Azores cetaceans field guide
Os Cetáceos (baleias e golfinhos) são um dos 5 grupos de mamíferos marinhos, juntamente com os pinípedes (focas, otárias e morsas), os sirénios (manatins e dugongos), as lontras e os ursos polares. Evidências moleculares e fósseis sugerem que baleias e golfinhos incluem-se dentro dos artiodáctilos, o grupo de mamíferos com cascos em número par, e.g. porcos, vacas e hipopótamos.ABSTRACT: Cetaceans (whales, dolphins, and porpoises) are one of the 5 groups of marine mammals, which also include pinnipeds (seals, sea lions, and walruses), sirenians (dugongs and manatees), sea otters, and polar bears. Fossil and molecular evidence suggests that whales and dolphins are a group within the artiodactyls (the group of eventoed, hoofed mammals that includes pigs, cattle and hippopotamus).N/
Cork oak forests soil bacteria: potential for sustainable agroforest production
Plant growth promoting rhizobacteria (PGPR) are in increasing demand due to their role in promoting sustainable practices, not only in agriculture but also in forestry. Keeping in mind the future application of PGPR for increasing cork oak sustainability, the aim of this study was to find cork oak PGPR isolates with increased nutrient solubilisation traits, able to promote root morphological changes and/or antagonize cork oak bark phytopathogens. Soils from three cork oak forests with distinct bioclimates (humid, semi-humid and semi-arid) were used for isolating bacteria. From the 7634 colony-forming units, 323 bacterial isolates were biochemically assayed for PGPR traits (siderophores production, phosphate solubilizing and organic acids production), and 51 were found to display all these traits. These PGPR were able to induce root morphological changes on Arabidopsis thaliana, like suppression of primary root growth, increase of lateral roots or root hairs formation. However, the most proficient PGPR displayed specific ability in changing a single root morphological trait. This ability was related not only to bacterial genotype, but also with the environment where bacteria thrived and isolation temperature. Bacteria from semi-arid environments (mainly Bacillus megaterium isolates) could hold a promising tool to enhance plant development. Other isolates (Serratia quinivorens or B. cereus) could be further explored for biocontrol purposes.This work was supported by FEDER funds through COMPETE (Programa Operacional Factores de Competitividade) and by national funds by FCT (Fundação para a Ciência e a Tecnologia) in
the framework of the projects SuberControl (PTDC/ASP-SIL/28635/2017), BioISI (UIDB/04046/2020)
and CIMO (UIDB/00690/2020)
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