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

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

Diversity and patterns of marine non‐native species in the archipelagos of Macaronesia

Aims The present study is the first attempt to grasp the scale and richness of marine biological invasions in Macaronesia. We pioneered a comprehensive non-native species (NNS), inventory in the region to determine their diversity patterns and native distribution origins. NNS were defined here as the result of both introductions and range expansions. We also used statistical modelling to examine relationships among NNS richness, anthropogenic activities, demographic and geographical variables across Macaronesia. Location Macaronesia. Methods A comprehensive literature search was conducted for marine NNS records in Macaronesia, registering the first record's location and year from 1884 to 2020. We used univariate and multivariate analyses to evaluate differences and similarities in community composition. By applying a Generalized Linear Model (GLM), we tested hypotheses regarding NNS richness as a function of anthropogenic activities, demographic and geographical variables. Results A total of 144 marine non-native species (NNS) were recorded for the whole of Macaronesia. The highest NNS richness was registered in the Canary Islands (76 NNS), followed by the Azores (66 NNS), Madeira (59 NNS) and finally Cabo Verde (18 NNS). Some differences amongst archipelagos were observed, such as the high number of non-native macroalgae in the Azores, fishes in the Canary Islands and tunicates in Cabo Verde. Overall, macroalgae, tunicates and bryozoans were the predominant taxonomic groups in the Macaronesian archipelagos. Madeira and Canary Islands were the archipelagos with more similarity in marine NNS, and Cabo Verde the most divergent. Finally, GLM suggested that non-native richness patterns across Macaronesia were dependent on the considered archipelago and strongly affected by (1) minimum distance to the mainland, (2) the total number of ports and marinas and (3) total marinas area (km2). Conclusions The model results and NNS listing in the present study will likely raise the awareness and response regarding marine NNS in the whole Macaronesia region, serving as a baseline for future research as well as implementing and enforcing regulations related to the introduction of marine NNS in oceanic islands

A global-scale screening of non-native aquatic organisms to identify potentially invasive species under current and future climate conditions

The threat posed by invasive non-native species worldwide requires a global approach to identify which introduced species are likely to pose an elevated risk of impact to native species and ecosystems. To inform policy, stakeholders and management decisions on global threats to aquatic ecosystems, 195 assessors representing 120 risk assessment areas across all six inhabited continents screened 819 non-native species from 15 groups of aquatic organisms (freshwater, brackish, marine plants and animals) using the Aquatic Species Invasiveness Screening Kit. This multi-lingual decision-support tool for the risk screening of aquatic organisms provides assessors with risk scores for a species under current and future climate change conditions that, following a statistically based calibration, permits the accurate classification of species into high-, medium-and low-risk categories under current and predicted climate conditions. The 1730 screenings undertaken encompassed wide geographical areas (regions, political entities, parts thereof, water bodies, river basins, lake drainage basins, and marine regions), which permitted thresholds to be identified for almost all aquatic organismal groups screened as well as for tropical, temperate and continental climate classes, and for tropical and temperate marine ecoregions. In total, 33 species were identified as posing a 'very high risk' of being or becoming invasive, and the scores of several of these species under current climate increased under future climate conditions, primarily due to their wide thermal tolerances. The risk thresholds determined for taxonomic groups and climate zones provide a basis against which area-specific or climate-based calibrated thresholds may be interpreted. In turn, the risk rankings help decision-makers identify which species require an immediate 'rapid' management action (e.g. eradication, control) to avoid or mitigate adverse impacts, which require a full risk assessment, and which are to be restricted or banned with regard to importation and/or sale as ornamental or aquarium/fishery enhancement. Decision support tools AS-ISK Hazard identification Non-native species Risk analysis Climate changepublishedVersio