Repositório RCAAP

The response of carob (Ceratonia siliqua L.) seedlings grown at different root zone temperatures affected by nitrate and ammonium nutrition was studied. When root temperatures ranged from 10 to 35°C, ammonium‐fed plants were significantly larger than nitrate‐fed plants. Ammonium‐fed plants displayed toxicity symptoms and were much smaller at 40°C root temperature in comparison with the nitrate‐fed plants grown at the same root temperature. Root/shoot ratio slightly increase with root temperature in ammonium‐ and nitrate‐fed plants in a similar way, and shoot demand per root unit decreased with root temperature between 15 and 25°C. There was a general increase in net photosynthesis with root temperature, though nitrate‐fed plants were more sensitive to low and ammonium‐fed plants to high temperatures. Increasing the root temperature of ammonium fed plants from 10 to 40°C leads to a 30% increase in the amount of photosynthates sent to the roots. The presence of ammonium resulted in the distribution of newly fixed carbon away from carbohydrates and into nitrogen compounds. Potassium, calcium, and nitrogen content of the plants also increased with increasing root temperature.

Introduction. During an investigation into the world-wide distribution of Anthoceros caucasicus Steph., we examined a voucher collected from Sierra Leone by A. J. Harrington in 1966 and subsequently studied by E. W. Jones. Methods. Based on spore observations using light and scanning electron microscopy we found that three Anthocerotophyta taxa were present in this mixed collection. Key results. We report Anthoceros aff. bharadwajii Udar & A.K.Asthana new to Africa, Phaeoceros laevis (L.) Prosk. new to Sierra Leone and tropical Africa, and Anthoceros punctatus L. new to Sierra Leone and western mainland Africa. Conclusions. Anthoceros caucasicus should be removed from the Sierra Leone bryoflora list, and possibly from tropical Africa.

In the face of the pandemic, we have been forced to adopt strategies in order to balance our doctoral work at the same time as caring for our families. As the digital turn has pervaded both social and academic milieus, we consider the potentials and shortcomings of remote interactions and approaches and how they have impacted our work and personal lives. We focus on the challenges of balancing paid work and the unpaid work of care, as well as considering potential changes to the concept of care in terms of building a caring culture.

Objective Determining the existence of a relationship between judicial performance and citizens’ trust in the legal system. Method Cross‐classified multilevel models, using data from more than 20 European countries, 80 surveys, and 100,000 respondents, over a decade. Results The longer the time that lower courts take, on average, to dispose of pending cases, the lower is the public's trust in their legal system. Conclusion Judicial performance, operationalized as the ability of courts to avoid delays in the delivery of justice, is a significant correlate of citizens’ evaluations of their country's legal system.

What executives are and what they do in democratic regimes should obviously be affected by public opinion. This occurs not only through the electoral process, but also through the influence that, in the interim, public attitudes exert on (re)election-minded politicians. But what drives public support for executives? This chapter focuses on four types of determinants: outcomes, processes, events, and time. After describing the findings of the early social-scientific studies on executive support of the 1970s and 1980s, we address the multiple caveats and contingencies that resulted from expanding these approaches to contexts different from those in which they originated. The result has been an increasing attention to heterogeneity: of effects, information levels, political and institutional contexts, and publics. Understanding this heterogeneity will be vital as we move more decisively in the future to the empirical study of the relationship between public opinion and the formation, survival, and (re)composition of executives.

Adopting an integrative approach that explicitly includes the different facets of biodiversity is crucial to assess the response of biological communities to changing environments. The identification of the optimal climatic conditions where communities maximize their functional, phylogenetic and taxonomic diversity is useful to compare whether the optima of the different facets of biodiversity match. Using a wide climatic gradient across Europe, we quantified the functional, phylogenetic and taxonomic diversity of epiphytic macrolichen communities, which are valuable early-warning ecological indicators. We ordinated 22 environmental variables and simultaneously illustrated non-parametric regressions of the diversity metrics against the climatic space using the 'hilltop plot' method to detect the climatic conditions in which the different diversity facets peaked and to compare the match between them. Functional diversity predicted at least part of the peaks of phylogenetic and taxonomic diversity, but phylogenetic and taxonomic hotspots did not overlap. Epiphytic macrolichen communities maximized their functional and phylogenetic diversity in the southernmost forests, with the Mediterranean region appearing as a biodiversity hotspot. Regarding the studied traits, photobiont type and growth form showed clearly defined optima while the quantitative physiological traits and families' optima did not show this pattern in response to climate. The different facets of biodiversity were not surrogates of each other highlighting the need for an integrative approach to assess the effect of environmental changes on communities and to establish conservation priorities. As functional traits mediated the response of lichen communities to climate, preserving high functional diversity might indirectly preserve high phylogenetic and taxonomic diversity. Relevant ecological indicators useful to develop rapid assessment methods to evaluate the effects of climatic changes include the photobiont type and growth form. The lack of relation between quantitative traits and climate call for further research to unveil their role as ecological indicators of small-scale variables or as effect traits.

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Aridity is a critical driver of the diversity and composition of plant communities. However, how aridity influences the phylogenetic structure of functional groups (i.e. annual and perennial species) is far less understood than its effects on species richness. As perennials have to endure stressful conditions during the summer drought, as opposed to annuals that avoid it, they may be subjected to stronger environmental filtering. In contrast, annuals may be more susceptible to interannual climatic variability. Here we studied the phylogenetic structure of the annual and perennial components of understorey plant communities, along a regional aridity gradient in Mediterranean drylands. Specifically, we asked: (1) How do species richness (S) and phylogenetic structure (PS) of annuals and perennials in plant communities respond to aridity? (2) What is the contribution of other climatic and topo-edaphic variables in predicting S and PS for both components? (3) How does the taxonomic and phylogenetic turnover of annuals and perennials vary with spatial and environmental distances? We assessed annuals' and perennials' species richness, the phylogenetic structure at deep and shallow phylogenetic levels, and taxonomic and phylogenetic turnover along spatial and environmental distances. We found no relationship between annuals' richness and aridity, whereas perennials' richness showed a unimodal pattern. The phylogenetic structure of annuals and perennials showed contrasting responses to aridity and negatively correlated with topo-edaphic variables. We found phylogenetic clustering at intermediate-to-higher aridity levels for annuals, and at lower aridity levels for perennials. Both taxonomic and phylogenetic turnover in annuals and perennials correlated with the environmental distance rather than with spatial distance between communities, suggesting adaptation to local factors. Overall, our results show a decoupling in the response of the phylogenetic structure of annual and perennial components of plant communities to aridity in Mediterranean drylands. Our findings have significant implications for land management strategies under climate change.

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As escavações arqueológicas levadas a efeito em Monte Molião permitiram recolher um conjunto muito significativo de artefactos metálicos, diversificados cronológica e funcionalmente, entre os quais se destacam os elementos de indumentária. Trata-se de fíbulas, de botões e de fechos de cinturão que pertencem à época romana, ocupação bem caracterizada no sítio através de sequências estratigráficas claras, que foram tidas em consideração na abordagem a estes materiais concretos.

Speciation is a fundamental process in evolution and crucial to the formation of biodiversity. It is a continuous and complex process, which can involve multiple interacting barriers leading to heterogeneous genomic landscapes with various peaks of divergence among populations. In this study, we used a population genomics approach to gain insights on the speciation process and to understand the population structure within the genus Sousa across its distribution in the Indo-Pacifc region. We found 5 distinct clusters, corresponding to S. plumbea along the eastern African coast and the Arabian Sea, the Bangladesh population, S. chinensis off Thailand and S. sahulensis off Australian waters. We suggest that the high level of differentiation found, even across geographically close areas, is likely determined by different oceanographic features such as sea surface temperature and primary productivity.

Com a presente dissertação pretende-se obter uma fórmula fechada para a avaliação de Insurance Linked Bonds. Esta avaliação foi efectuada primeiramente utilizando taxas de juro determinísticas, e seguidamente num ambiente onde imperam taxas de juro estocásticas, para as quais se aplicou o modelo de Vasicek. A abordagem utilizada consiste essencialmente na obtenção da first passage time do índice pelo trigger. No caso determinístico, optou-se por uma abordagem com recurso a mudanças de medida de probabilidade e ao Lema de Itô. Para o caso estocástico, foi utilizada uma equação integral de Volterra de segundo grau, sendo que se tornou necessário deduzir a distribuição condicional da taxa de juro, a distribuição condicional do índice e a distribuição incondicional do índice. Estas distribuições são posteriormente utilizadas para se obter implicitamente a first passage time density.

A clear understanding of population structure is essential for assessing conservation status and implementing management strategies. A small, non-migratory population of humpback whales in the Arabian Sea is classified as "Endangered" on the IUCN Red List of Threatened Species, an assessment constrained by a lack of data, including limited understanding of its relationship to other populations. We analysed 11 microsatellite markers and mitochondrial DNA sequences extracted from 67 Arabian Sea humpback whale tissue samples and compared them to equivalent datasets from the Southern Hemisphere and North Pacific. Results show that the Arabian Sea population is highly distinct; estimates of gene flow and divergence times suggest a Southern Indian Ocean origin but indicate that it has been isolated for approximately 70,000 years, remarkable for a species that is typically highly migratory. Genetic diversity values are significantly lower than those obtained for Southern Hemisphere populations and signatures of ancient and recent genetic bottlenecks were identified. Our findings suggest this is the world's most isolated humpback whale population, which, when combined with low population abundance estimates and anthropogenic threats, raises concern for its survival. We recommend an amendment of the status of the population to "Critically Endangered" on the IUCN Red List.

Natural hybridization may result in the exchange of genetic material between divergent lineages and even the formation of new taxa. Many of the Neo-Darwinian architects argued that, particularly for animal clades, natural hybridization was maladaptive. Recent evidence, however, has falsified this hypothesis, instead indicating that this process may lead to increased biodiversity through the formation of new species. Although such cases of hybrid speciation have been described in plants, fish and insects, they are considered exceptionally rare in mammals. Here we present evidence for a marine mammal, Stenella clymene, arising through natural hybridization. We found phylogenetic discordance between mitochondrial and nuclear markers, which, coupled with a pattern of transgressive segregation seen in the morphometric variation of some characters, support a case of hybrid speciation. S. clymene is currently genetically differentiated from its putative parental species, Stenella coerueloalba and Stenella longisrostris, although low levels of introgressive hybridization may be occurring. Although non-reticulate forms of evolution, such as incomplete lineage sorting, could explain our genetic results, we consider that the genetic and morphological evidence taken together argue more convincingly towards a case of hybrid speciation. We anticipate that our study will bring attention to this important aspect of reticulate evolution in non-model mammal species. The study of speciation through hybridization is an excellent opportunity to understand the mechanisms leading to speciation in the context of gene flow.

Private protected areas (PPAs) are considered a promising governance conservation tool to complement public-run protected areas. Despite their promotion in national and international environmental agendas and increased adoption worldwide, there has been little research on the overarching implications of their implementation. This paper introduces a framework to explore the suitability of the institutional arrangements of PPAs to enhance nature conservation whilst meeting societal needs. To do so, we draw on the literature on socio-ecological systems incorporating insights from critical perspectives on agency and power. The resulting conceptual approach pinpoints the interplays between the ecological and social systems, providing a systemic perspective which underpins an interdisciplinary diagnostic framework. This draws on the concepts of social and ecological fit and integrates contributions from the literature on good governance; fine-tuning good governance principles to suit PPAs. We outline a multi-tiered tool for assessing PPAs. This is a first step to comprehensively addressing the match of PPAs’ institutional models with the ecological and social dimensions of complex systems.

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In this article, I discuss the role of plantation museums in confronting, legitimizing, and filtering the racialized violence on which the plantation economy stood. I start with a brief review of the literature on plantation societies, discuss the plantation–race nexus, and highlight the renewed interest in plantations raised by contemporary approaches to the environment, the Anthropocene, cropscapes, and nonhuman agencies. Next, I compare different modes of instrumentalizing and displaying the memory of the plantation, some of which are critical of its violence, and some of which are oblivious to it. Some are focused on technical aspects of sugar production, while others are focused on its labor force. Finally, I present in detail Hawai‘i's Plantation Village in Waipahu, O‘ahu. This community-based museum is designed in accordance with the prevailing narrative of a multiethnic Hawai‘i. While it provides visitors with an overview of the plantation experience in general, not excluding the discipline and violence endured by laborers, its main focus is on the specific cultural heritage of each one of the nationalities that arrived in Hawai‘i to work in sugar. I argue that the museum project is consistent with an idealized view of Hawai‘i's society as a multiethnic racial paradise. This image emerged in the 1920s and helped expunge from collective perception the racialized hierarchies that structured the labor force while also erasing from the picture the structural tension between natives and settlers regarding the appropriation of land and subsequent rights, entitlements, and impediments. I further argue that the presentation of a collective heritage composed of multiple distinct identities originating in the plantation era provides a tool that counterweights the unresolved and unsettled tensions of the contemporary post-plantation world.

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Diante dos desafi os colocados no contexto contemporâneo em torno da discussão sobre a pesca, seus saberes, ambientes e suas transformações, o presente dossiê traz refl exões diversifi cadas em termos de campos etnográfi cos realizados por pesquisadores brasileiros e estrangeiros e perspectivas teóricas. O mote das análises aqui apresentadas reside, ao mesmo tempo, no enfrentamento teórico e na evidenciação etnográfi ca das transformações ensejadas nas práticas e nos modos como diferentes grupos de pescadores e pescadoras têm interpretado e atuado no contexto de seus ambientes e quais são os desafi os por eles enfrentados para a reprodução dos modos de vida de suas famílias.

O jornalismo atravessa um período de turbulência, assinalado pela diminuição do número de vendas de publicações impressas e, ao mesmo tempo, pelo surgimento de novos media. A resposta por parte dos meios de comunicação social (MCS) tem passado pela adaptação a este quadro (Compton & Bennedeti, 2010; Garcia et al., 2018). A par da aposta na reformulação do produto, doravante em formato digital, e dos meios mobilizados no seu fabrico, as empresas sujeitam-se a processos de reengenharia, reduzindo custos por via quer da redução de efetivos, quer do recurso a vínculos temporários, como estágios e contratos a termo certo ou de prestação de serviços (“recibo-verde”). 2 O objetivo deste artigo é analisar estas transformações à luz dos percursos socioprofissionais de ex-jornalistas. A atual morfologia das relações de trabalho dificulta uma definição precisa desta categoria. A limitação do universo a quem chegou a deter a carteira profissional poderia, como se constatará, revelar-se demasiado restritiva. Como tal, considerou-se ex-jornalista toda a pessoa que, tendo exercido jornalismo, não se encontra presentemente a desenvolver a atividade. O estudo do jornalismo a partir da experiência de quem já não o exerce permite compreender o que motivou a rutura com a profissão, bem como identificar as novas áreas de emprego (ou de desemprego) e a sua proximidade com os MCS.