Temperature and deuteration effects on the fluorescence of benzenoid solutions

Deuterium isotope substitution and temperature effects on the fluorescence of toluene and p-xylene solutions have been investigated. Values of fluorescence quantum yields were measured between -80° to 70°C for p-xylene, p-xylene d 10 , toluene and toluene- d 8 and also fluorescence decay times at room temperature. The influence of several experimental factors on the fluorescence intensity at various temperatures was investigated and corrections were applied to obtain correct quantum yields. The results are compatible with an absence of a normal deuteration effect, and are independent of temperature, for both molecules, and show the existence of a non-radiative transition from the first excited single state to the ground state.info:eu-repo/semantics/publishedVersio

Temperature effects on fluorescence quantum efficiency of 9,10-diphenylanthracene

The fluorescence quantum efficiency of 9,10-diphenylanthracene in ethanol was measured with very dilute solutions (not more than 5 × 10 -6 M), between 170 and 350 K, relative to solutions at room temperature. The results are compatible with a quantum efficiency of 0.88 at room temperature, which increases to 1.00 for temperatures below 190 K.North Atlantic Treaty Organization (NATO)info:eu-repo/semantics/publishedVersio

Temperature and solvent effects on photoluminescence of tryptophan solutions

The fluorescence of tryptophan solutions in glycerol, water and ethanol was measured as a function of temperature using steady state and time-resolved techniques. The non-radiative rate constants responsible for the variation of fluorescence quantum yields with temperature are evaluated. Spectral shifts occurring on the nanosecond scale are interpreted in terms of an inversion of 1 L b and 1 L a states produced by solvent perturbation.info:eu-repo/semantics/publishedVersio

CoastNet Dataset From Mondego, Tejo and Mira Estuaries: Multiparametric Measurements During 2020

info:eu-repo/semantics/publishedVersio

The Atlantic blue crab Callinectes sapidus in southern European coastal waters: distribution, impact and prospective invasion management strategies

[EN] The native distribution of the blue crab Callinectes sapidus in the western Atlantic extends from Nova Scotia to Argentina. Introduced to Europe at the beginning of the 20th century, it is currently recorded almost ubiquitously in the Mediterranean and in the Black Sea. An overview of the occurrence, abundance, and ecological impact of the species in southern European waters is provided; additionally, we present a pragmatic assessment of its management scenarios, explicitly considering the dual nature of C sapidus as both an invasive species and a fishery resource. We emphasise that the ongoing expansion of C sapidus in the region may represent a stimulating challenge for the identification and implementation of future strategies in the management of invasive crustaceans. The impact of the invader could be converted into an enhancement of the services delivered by southern European coastal ecosystems, while mitigation costs could be transformed into profits for local populations. (C) 2017 Elsevier Ltd. All rights reserved.Funding from FUR 2013-2014 and 2014-2015 to G. M. is acknowledged. The European Fisheries Fund (FEP) Puglia Region (Italy) supported L. C. (CIP 04/OPI/010) as the scientific head of the MOLEVAR project (Pilot Project for the production of soft crabs from Carcinus aestuarii in Varano lagoon). The Portuguese Science Foundation (FCT) supported F. R. (SFRH/BPD/46761/2008) with a post-doctoral research grant from the Programa Operacional Potencial Humano/Fundo Social Europeu (POPH/FSE). F. R. and P. C. were also supported by the strategic MARE plan - Marine and Environmental Sciences Centre (UID/MAR/04292/2013).Mancinelli, G.; Chainho, P.; Cilenti, L.; Falco, S.; Kapiris, K.; Katselis, G.; Ribeiro, F. (2017). The Atlantic blue crab Callinectes sapidus in southern European coastal waters: distribution, impact and prospective invasion management strategies. Marine Pollution Bulletin. 119(1):5-11. https://doi.org/10.1016/j.marpolbul.2017.02.050S511119

Metal and semimetal loadings in sediments and water from mangrove ecosystems: A preliminary assessment of anthropogenic enrichment in São Tomé island (central Africa)

Mangroves act as buffer areas for marine systems, providing a barrier to contamination from continental sources by retaining metal pollutants. This study evaluates metal and semimetal contamination in the water column and sediments of four mangroves located on the volcanic island of São Tomé. Several metals had a widespread distribution, with occasional high concentrations, linked to potential sources of contamination. However, the two smaller mangroves, located in the northern part of the island, tended to have high metal concentrations. Arsenic and chromium concentrations were notably concerning, particularly if we consider this is an isolated and non-industrialized island. This work highlights the need for further assessments and a better understanding of processes and implications of metal contamination in mangroves. This assumes a particular relevance in areas that have specific geochemical compositions (i.e., volcanic origin) and in developing countries, where people often rely directly and heavily on resources obtained from these ecosystems.info:eu-repo/semantics/publishedVersio

Associativismo popular e envelhecimento ativo: o caso do distrito de Leiria

Portugal é um país envelhecido. Em 2019, 22% da população tinha 65 e mais anos. E uma das explicações está relacionada com o aumento gradual da esperança média de vida. Vive-se mais tempo –e esse dado é positivo. Mas importa também questionar como se vive –como vivem as pessoas com mais idade. E que políticas (públicas e sociais) têm sido desenvolvidas para assegurar um envelhecimento ativo e produtivo. O presente estudo parte desses conceitos centrais (envelhecimento ativo e produtivo); e visa compreender o contributo do associativismo popular na promoção de práticas para um envelhecimento ativo, saudável e produtivo. As pessoas com mais idade participam nas associações? São associadas? São praticantes das modalidades desenvolvidas? Que atividades? Envolvem-se no exercício de funções dirigentes (como dirigentes associativos voluntários)? E de que forma é que esse envolvimento contribui para serem mais felizes e terem mais saúde? E para conseguirem ter um envelhecimento ativo e produtivo?info:eu-repo/semantics/publishedVersio

Inter-annual variations of macrobenthic communities over three decades in a land-locked coastal lagoon (Santo André, SW Portugal)

Santo Andre is an enclosed brackish water coastal lagoon with temporary connections to the sea by a man-made channel. The exchange and mixture of saltwater and freshwater is irregular and the lagoon may show daily and seasonal fluctuations, but also long-term variation. Different benthic communities may be present along the annual cycle according to the magnitude of episodic freshwater and sea water inputs. In the last 30 years the communication with the sea has followed different regimes from year to year and, as a consequence, macrobenthic communities, assessed several times during the period before the opening to the sea, shifted from freshwater to marine affinities. Major differences were found between 1979 and 2010, with a preponderance of species with marine affinity, and the 1980s in which the organisms with freshwater affinity prevailed. Benthic communities are frequently used to assess aquatic environmental condition. Metrics used in the indices currently under discussion to assess ecological status of aquatic ecosystems within the scope of European Water Framework Directive were applied to Santo Andre data and the applicability of these metrics to assess quality in this coastal land-locked lagoon was discussed. (C) 2012 Elsevier Ltd. All rights reserved.National Institute of Scientific Research; ICNB (Nature, Conservation and Biodiversity Institute); EEC (European Economic Community); Cohesion Fund under Priority 111 of the Operational Programme for Territorial Development (POVT); FCT (Science and Technology Foundation) [PTDC/AAC-AMB/104639/2008, PEst-OE/MAR/UI0199/2011]; FCT [SFRH/BPD/29579/2006

Short-term versus long-term changes in the benthic communities of a small coastal lagoon: implications for ecological status assessment

The characteristic high variability and low predictability of coastal lagoons, due to strong changes in marine and freshwater inputs, make these ecosystems an interesting casestudy. The small Melides landlocked coastal lagoon in SW Portugal is a paradigmatic example, with a biological community highly stressed by these phenomena. Benthic macroinvertebrate samples were collected in 1998/99 and 2009 and each year, in different seasons and addressing different environmental conditions influenced by the connection to the sea and rainfall regime. Major spatial and temporal patterns in benthic communities were investigated using some invertebrate attributes (e.g. community composition, density, species richness and diversity). A very low taxonomic species richness and diversity was found in the Melides lagoon and only a much reduced number of species occurred along all sampling periods and in both sampling campaigns. Although the colonization events play a crucial role, the persistence of the observed species was mainly associated to abiotic factors, such as salinity, temperature and dissolved oxygen. Despite the potential reduction in anthropogenic pressure, by the construction of a sewage treatment plant and a reduction of urban occupation, the ecological status did not improve and the high level of natural environmental variably in the lagoon seems to be the dominant stressor influencing benthic invertebrate communitie

Short-Term Biochemical Biomarkers of Stress in the Oyster Magallana angulata Exposed to Gymnodinium catenatum and Skeletonema marinoi

Additionally, this work was also co-funded by the MAR2020, Portugal 2020 and the European Union EMFF projects (MAR-02.01.01-FEAMP-0050, MAR-02.01.01-FEAMP-0051 and MAR-01.03.02-FEAMP-0013). Publisher Copyright: © 2023 by the authors.Bivalves accumulate toxins produced by microalgae, thus becoming harmful for humans. However, little information is available about their toxicity to the bivalve itself. In the present work, the physiological stress and damage after the ingestion of toxic dinoflagellate species (Gymnodinium catenatum) and a diatom species (Skeletonema marinoi, which is non-toxic to humans but may be to grazers) in the oyster Magallana angulata are evaluated against a control treatment fed with the chlorophyte Tetraselmis sp. Oysters were exposed for two hours to a concentration of 4 × 104 cells/L of G. catenatum and 2 × 107 cells/L of S. marinoi. The biomarkers superoxide dismutase (SOD), catalase (CAT), glutathione S-Transferase, total Ubiquitin (Ubi) and Acetylcholinesterase (AchE) were assessed. The exposure of M. angulata to G. catenatum lead to a reduction in SOD and AchE activity and ubiquitin concentrations when compared to the control treatment. Moreover, it increased CAT activity in the adductor muscle, and maintained its activity in the other tissues tested. This may be related to the combination of reduced metabolism with the deployment of detoxification processes. S. marinoi also lead to a decrease in all biomarkers tested in the gills and digestive glands. Therefore, both species tested caused physiological alterations in M. angulata after two hours of exposure.publishersversionpublishe