CO2 conversion to phenyl isocyanates by uranium(vi) bis(imido) complexes.

Uranium(vi) trans-bis(imido) complexes [U(κ4-{(tBu2ArO)2Me2-cyclam})(NPh)(NPhR)] react with CO2 to eliminate phenyl isocyanates and afford uranium(vi) trans-[O[double bond, length as m-dash]U[double bond, length as m-dash]NR]2+ complexes, including [U(κ4-{(tBu2ArO)2Me2-cyclam})(NPh)(O)] that was crystallographically characterized. DFT studies indicate that the reaction proceeds by endergonic formation of a cycloaddition intermediate; the secondary reaction to form a dioxo uranyl complex is both thermodynamically and kinetically hindered

Relação entre o otimismo e a vulnerabilidade ao stress na população adulta

Resumo da comunicação apresentada no XIII Congreso Internacional y XVIII Congreso Nacional de Psicología Clínica. Santiago de Compostela (virtual), 11-14 Novembro 2020info:eu-repo/semantics/publishedVersio

Modelling the impact of deep-water crustacean trawl fishery in the marine ecosystem off Portuguese Southwestern and South Coasts: I) the trophic web and trophic flows

The concentration of the population in coastal regions, in addition to the direct human use, is leading to an accelerated process of change and deterioration of the marine ecosystems. Human activities such as fishing together with environmental drivers (e.g. climate change) are triggering major threats to marine biodiversity, and impact directly the services they provide. In the South and Southwest coasts of Portugal, the deep-water crustacean trawl fishery is not exemption. This fishery is recognized to have large effects on a number of species while generating high rates of unwanted catches. However, taking into account an ecosystem-based perspective, the fishing impacts along the food web accounting for biological interactions between and among species caught remains poorly understood. These impacts are particularly troubling and are a cause of concern given the cascading effects that might arise. Facing the main policies and legislative instruments for the restoration and conservation of the marine environment, times are calling for implementing ecosystem-based approaches to fisheries management. To this end, we use a food web modelling (Ecopath with Ecosim) approach to assess the fishing impacts of this particular fishery on the marine ecosystem of southern and southwestern Portugal. In particular, we describe the food web structure and functioning, identify the main keystone species and/or groups, quantify the major trophic and energy flows, and ultimately assess the impact of fishing on the target species but also on the ecosystem by means of ecological and ecosystem-based indicators. Finally, we examine limitations and weaknesses of the model for potential improvements and future research directions.info:eu-repo/semantics/publishedVersio

By-catch species susceptibilities and potential for survival in Algarve (southern Portugal) deep-water crustacean trawl fishery

Bottom trawling for crustaceans in Portuguese coastal waters is an important fishery in terms of revenue, despite its negative impacts on deep-sea ecosystems. This fishery catches large amounts of unwanted species that were discarded for various reasons before the introduction of the Landing Obligation, which banned the discarding of regulated species. However, where it can be demonstrated that a species has an acceptably high likelihood of survival, exemptions to this ban may be granted. In this study, time-to-mortality was used to estimate immediate mortality rates and identify important biological characteristics determining the susceptibility of 14 by-catch species. most with commercial interest (Conger conger, Galeus melastomus, Helicolenus dactylopterus, Lepidorhombus boscii, Lophius budegassa, Lophius piscatorius, Merluccius merluccius. Micromesistius poutassou, Mullus surmuletus, Phycis blennoides. Scyliorhinus canicula, Trigla lyra. Trachurus trachurus and Trachurus piciuratus). Species with potential to survive after the discarding process were identified and a short-term survival assessment of conger eel (Conger conger) was performed. The results suggest that species with scales, gas bladder and high metabolic rates have higher post-discard mortality. Size was a critical factor determining survival in some species, with smaller individuals dying faster. The short-term survival rate of conger eel was determined to be 84% (95% Cl: 75.5 to 93.3%). The methodology and results from this study can help identify species that may survive the discarding process and factors influencing their survival.MINOUW project - Horizon 2020 Framework Programme of the European Union - 634495info:eu-repo/semantics/publishedVersio

New Emigration and Portuguese Society: Transnationalism and Return

This chapter addresses the theme of transnationalism and return in recent Portuguese emigration, namely the flows that occurred after the turn of the century. It starts with a brief theoretical overview on those topics, which constitute two relatively neglected characteristics of Portuguese emigration. Next, based on a survey carried out in 2014–2015 to more than 6000 recent emigrants, it reveals some of the links that they maintain with their home country, as well as their plans for the future, which include settlement in the destination country, return and re-emigration. Lastly, it examines data on returning emigrants – especially those that returned between 2001 and 2011 – extracted from the 2011 Census. The evidence reveals a significant number of returns, including individuals at both working and retirement ages and at all skill levels, thus exposing the unexpected complexity of movements. The results are based on the research project “Back to the future: new emigration and links with Portuguese society” (REMIGR), which aimed to ascertain the extent and characteristics of the new emigration wave. The project included an overview of emigration and return to and from all regions of the world, as well as case studies in UK, France, Luxembourg, Angola, Mozambique and Brazil.info:eu-repo/semantics/publishedVersio

Fine scale population genomics of the bottlenose dolphin off Western Iberia (northeast Atlantic)

34th European Cetacean Society Conference, O Grove, 16-20 April 2023Bottlenose dolphin (Tursiops truncatus) populations sampled across various geographic regions show fine-scale patterns of genetic structure, likely associated with local habitat preferences. Several population genetic studies have focused on populations from the northeast Atlantic Ocean (NEA), very few including the Portuguese coast. This study investigated the population structure and demographic history of the bottlenose dolphin in this region using double digest restriction site associated DNA sequencing (ddRAD-seq). Samples were collected from the Iberian Peninsula including SW Spain, the Portuguese coast (including Sado estuary), NW Spain and from two Portuguese Macaronesian archipelagos, Madeira and Azores (N=110 samples). We genotyped thousands of single nucleotide polymorphisms markers to study the fine-scale population structure, inbreeding levels and demographic history. Bayesian clustering and Principal Component Analyses showed three major genetic clusters: Pelagic (incl. Madeira and Azores; North Galicia, Portugal coast), Southern/Mediterranean (incl. Gibraltar/Cadiz, previously identified as of Mediterranean origin, and Portugal coast), and Resident (Sado and south Galicia). These clusters differ from each other in terms of genetic diversity and inbreeding levels. While the Pelagic and Southern/Med clusters shows high genetic diversity and a wide geographic distribution, the Resident populations show the opposite. The Resident cluster can be subdivided in Galicia and Sado populations, the latter revealing concerning levels of inbreeding. Preliminary demographic analyses suggest that the Resident populations diverged from the others prior to the Southern/Med-Pelagic divergence, although further analyses are needed. Our results suggest that i) the Resident populations of the Iberian Peninsula should be considered as different management units; ii) bottlenose dolphins sampled along the Portuguese coast are highly genetically diverse, including individuals from the three different clusters; and iii) the Sado population faces a critical situation. Within the framework of the recently proposed SACs for bottlenose dolphins in Portugal, these results highlight the importance of discussions on conservation and management policiesN

Interactions between the common dolphin, Delphinus delphis, and the Portuguese purse seine fishery over a period of 15 years (2003–2018)

Interactions between cetaceans and the purse seine fishery in coastal waters of mainland Portugal were investigated using onboard observations over a period of 15 years (2003-2018). In 10% of the fishing sets, there were interactions with one of three species of cetaceans: common dolphin (Delphinus delphis), bottlenose dolphin (Tursiops truncatus), and harbour porpoise (Phocoena phocoena). The common dolphin was the most frequently observed species, occurring in 89% of all interaction events, and the only species with observed mortality. Therefore, this study focused only on the interactions with common dolphins. A generalized additive model (GAM) was applied to observer data to investigate how the fishing activity and the abundance of small pelagic fish influenced the probability of occurrence of interactions between the common dolphin and the purse seine fishery between 2003 and 2018. The results revealed significant annual and geographic variation in the occurrence of interactions, and a significant influence of fishing effort and catch per unit effort of sardine (Sardina pilchardus). A second GAM in a hurdle model was used to model the number of common dolphins that interacted with the fishing activity as a function of fishing seasonality and the local abundance of pelagic fish. There was a significant effect of the seasonality of the fishing activity and catch per unit effort of sardine and chub mackerel (Scomber colias) on the number of common dolphins interacting with the fishery. The results of this study suggest that the probability of interactions and the number of common dolphins interacting with the fishery were affected by the local abundance of sardine and chub mackerel. As the common dolphin population appears to be increasing in the study area, the risk of by-catch also increases, thus the monitoring of the Portuguese purse seine fishery is important to inform the implementation of management plans, and also as a response to global efforts for sustainable fisheries and marine mammal conservation.info:eu-repo/semantics/publishedVersio

A magnetic study of a layered lanthanide hydroxide family: Ln₈(OH)₂₀Cl₄·nH₂O (Ln = Tb, Ho, Er)

Three layered lanthanide hydroxides (LLHs), with the general formula Ln8(OH)20Cl4·nH2O (Ln = Tb (1), Ho (2), Er (3)), were prepared and magnetically characterized. These compounds were further diluted within a yttrium diamagnetic matrix, LYH:xLn, LYH:0.044Tb (1’), LYH:0.045Ho (2’), and LYH:0.065Er (3’), being the study complemented with theoretical calculations in order to understand the electronic configuration and the contributions to the slow relaxation behavior. In the pure compounds dominant 3D ferromagnetic interactions are observed, with a small magnetization hysteresis at 1.8 K for 1, while the magnetically diluted solid solutions display slow relaxation of the magnetization at low temperatures