Combining ERT, TDEM, and FDEM in shallow geophysical investigation

Tese de mestrado, Ciências Geofísicas (Geofísica Interna), Universidade de Lisboa, Faculdade de Ciências, 2019Nesta dissertação são apresentados os resultados da combinação de três métodos geofísicos aplicados a dois casos de estudo distintos em Portugal continental, com o objetivo de comparar os resultados obtidos. Os métodos aplicados foram: Tomografia de Resistividade Elétrica (ERT), Eletromagnético no Domínio do Tempo (TDEM) e Eletromagnético no Domínio da Frequência (FDEM). O primeiro caso de estudo localiza-se próximo a um reservatório de águas contaminadas de uma instalação industrial. O principal objetivo era detetar e definir zonas de contaminação de águas subterrâneas. Para esse efeito, foram aplicados dois métodos em dois perfis: ERT e FDEM. No primeiro perfil, o método FDEM deteta uma zona de alta resistividade na parte mais superficial (~ 25 m) e a parte superior de uma área contaminada. Os perfis de ERT atingem maiores profundidades e definem toda a área contaminada sobre uma zona não fraturada. No segundo perfil, o método FDEM deteta a parte mais superficial (~ 20 m de profundidade) com a presença de duas falhas que controlam a circulação das águas subterrâneas. Esse recurso também é detetado no perfil ERT que penetra mais profundamente, detetando a presença de duas áreas contaminadas. O segundo caso de estudo é desenvolvido sobre uma zona aluvial próxima ao rio Tejo, onde está em construção um parque insustrial. O principal objetivo é investigar se a área tem as condições necessárias para a construção do ponto de vista da engenharia. Nesta área, foram aplicados os três métodos nos três perfis: ERT, TDEM e FDEM. No primeiro perfil, a combinação dos três métodos permitiu a deteção de três camadas: uma superficial e plana com alta resistividade (origem antrópica), sobre uma área de resistividade muito baixa, com morfologia heterogénea (sedimentos com grande quantidade de argilas) e, no fundo, uma área de resistividade intermediária (rocha e águas subterrâneas). O segundo perfil foi adquirido paralelamente ao primeiro e combina as técnicas ERT e TDEM. Ambos detetaram as mesmas camadas do primeiro perfil, com formas diferentes, o leito rochoso é mais superficial e mergulha em direção a noroeste. O terceiro perfil estava localizado perpendicularmente aos anteriores. Este perfil (ERT) deteta e define as falhas na zona de estudo. Além disso, foi realizado o cálculo da resistividade aparente e posterior inversão para os dados do FDEM-8. Os resultados são muito encorajadores, em que na maioria dos perfis foi obtida uma resposta quantitativa de acordo com os outros métodos utilizados (ERT e TDEM). No entanto, é necessário mais trabalho para obter um melhor modelo optimizado que permita uma interpretação detalhada. Esta investigação demonstra a complementaridade dos métodos geofísicos utilizados. O método ERT deteta os recursos no subsolo com mais detalhes. O TDEM e o FDEM definem melhor a localização das camadas condutoras, pois são muito sensíveis à presença de material condutor. Os três métodos são muito apropriados para serem aplicados em casos semelhantes de estudo, tanto em hidrogeologia quanto em engenharia.The combination of three geophysical methods in two different case studies is presented in this dissertation. The applied methods were Electrical Resistivity Tomography (ERT), Time-Domain Electromagnetic (TDEM) and Frequency-Domain Electromagnetic (FDEM). Two different areas in Portugal (onshore) were selected aimed to compare the results obtained in the different methods. The first case study is located close to the contaminated water reservoir of an industrial facility. The main objective in this area was to detect and define the contamination zones and features that constrain the groundwater circulation. Here, two methods were applied along two profiles: ERT and FDEM. At the first profile, FDEM methods detect a high resistivity zone at the shallower part (~25 m) and the upper part of a contaminated area. ERT goes deeper depths and defines the whole contaminated area over a non-fractured zone. At the second profile, the FDEM method detects the shallower part (~20 m depth) with the presence of two faults that control the groundwater circulation. This feature is also detected in the ERT profile that penetrates deeper, detecting the presence of two contaminated areas. The second case of study is developed over an alluvial zone close to the Tajo River where an industrial park is under construction. The main objective is to investigate if the area is appropriate for construction from an engineering point of view. In this area, three methods along 3 profiles were applied: ERT, TDEM, and FDEM. In the first profile the combination of the three methods allowed the detection of 3 layers: a flat shallower area with high resistivity (anthropic origin), over a very low resistivity area with heterogeneous morphology (sediment with high quantity of clays) and, at the bottom, an intermediate resistivity area (bedrock and groundwater). The second profile was acquired parallel to the first and it combines ERT and TDEM techniques. Both detected the same layers as in the first profile with different shapes, the bedrock is shallower and that dipping toward NW. The third profile was located perpendicular to the previous ones. This profile (ERT) detects and defines the faults in the area. Additionally, an optimization of the apparent resistivity calculation and further inversion for FDEM-8 data were performed. The results are very encouraging, wherein most profiles a quantitative response was obtained in agreement with the other methods (ERT and TDEM). However, more work is needed in order to obtain a better method that allows detailed interpretation. This investigation demonstrates the complementarity of the used geophysical methods. ERT method detects the features at the subsoil with more detail. TDEM defines better the location of the conductive layers since it is very sensitive to the presence of conductive material such as FDEM. The three methods are very appropriate to be applied in similar cases of study, both, hydrogeology and engineering purposes

Animal Navigation: The Eel's Magnetic Guide to the Gulf Stream.

The geographic distribution of migratory species can span thousands of kilometers. Yet, traits that enable large-scale migrations are poorly understood. A recent study demonstrates that juvenile eels use the Earth's magnetism for their dispersal, with possible implications for their evolution

Legados linguísticos da (des) colonização britânica e portuguesa em África: laços comuns (mal) bem-sucedidos?

O Reino Unido e Portugal partilham um passado de expansão territorial em África, um continente com uma grande variedade cultural e linguística. As políticas de língua e de educação implementadas durante a colonização e descolonização prevalecem devido à interdependência económica e financeira gerada pela actual situação global. A Commonwealth e a CPLP são também, em parte, responsáveis pela manutenção de relações distintivas com as antigas colónias que levaram à promoção da língua como forma de soft power. Este é um estudo comparativo que analisa as esferas linguísticas e culturais Anglófonas e Lusófonas em África. É possível concluir que existe uma lacuna indesejável entre as políticas oficiais e as realidades linguísticas, que só podem ser entendidas através do paradoxo, a característica que melhor define os legados linguísticos do inglês e do português em África.info:eu-repo/semantics/publishedVersio

The Presence and Influence of English in the Portuguese Financial Media

As the lingua franca of the 21st century, English has become the main language for intercultural communication for those wanting to embrace globalization. In Portugal, it is the second language of most public and private domains influencing its culture and discourses. Language contact situations transform languages by the incorporations they make from other languages and Portugal has witnessed an increase in the pervasion of English in written communication. The aim of this study is to disclose how this sociolinguistic behavior is perceived by examining the presence of English loanwords in the Portuguese financial media to uncover its role and functions. Three Portuguese newspapers, Diário Económico, Expresso Economia and Vida Económica were chosen as the corpus of analysis over a two-week period in January 2016 corresponding to the pre and post presidential election weeks. This may reveal if the electoral results affect the presence of English. The motivations of journalists for borrowing English items and the reactions of readers complement the analysis. Results have shown English borrowing as an acceptable/accepted behavior in the analyzed Portuguese financial newspapers.info:eu-repo/semantics/publishedVersio

Incorporating evolutionary based tools in cephalopod fisheries management

With gradual decline of global finfish resources, fisheries targeting cephalopods expanded. Yet, the stock assessment and management practice are frequently lacking, and existing ones often remain poorly suited for cephalopod unique life-history. In light of increasing ecological disturbances in marine ecosystems worldwide, assessing exploited species’ status and response becomes vital for devising effective strategies that would ensure their sustainable management. There is generally scarce understanding of the way fisheries and other environmental stressors exert their combined effects on cephalopods stock dynamic and long-term resilience. To that end, evolutionary-based population studies that inform on identity, connectivity and adaptive potential of natural populations present a unique opportunity for assessing the viability of exploited cephalopod stocks. Such studies have been revolutionized in the last decade by proliferation of next generation sequencing technologies. They offer new avenues for expanding our knowledge, especially on population structure and the evolutionary responses to shifts in environmental pressures. In this paper we elaborate on how deep genomic insights into demographic and evolutionary status of fished cephalopods could improve their stock assessment and management practice. We also propose that the common octopus Octopus vulgaris would be a suitable model species to test the power of evolutionary tools to inform fishery scientists and managers on biological questions relevant for their sustainable exploitation.Fundação para a Ciência e Tecnologia - FCTinfo:eu-repo/semantics/publishedVersio

Targeted sequencing of mitochondrial genes reveals signatures of molecular adaptation in a nearly panmictic small pelagic fish species

Ongoing climatic changes, with predictable impacts on marine environmental conditions, are expected to trigger organismal responses. Recent evidence shows that, in some marine species, variation in mitochondrial genes involved in the aerobic conversion of oxygen into ATP at the cellular level correlate with gradients of sea surface temperature and gradients of dissolved oxygen. Here, we investigated the adaptive potential of the European sardine Sardina pilchardus populations offshore the Iberian Peninsula. We performed a seascape genetics approach that consisted of the high throughput sequencing of mitochondria's ATP6, COI, CYTB and ND5 and five microsatellite loci on 96 individuals coupled with environmental information on sea surface temperature and dissolved oxygen across five sampling locations. Results show that, despite sardines forming a nearly panmictic population around Iberian Peninsula, haplotype frequency distribution can be explained by gradients of minimum sea surface temperature and dissolved oxygen. We further identified that the frequencies of the most common CYTB and ATP6 haplotypes negatively correlate with minimum sea surface temperature across the sampled area, suggestive of a signature of selection. With signatures of selection superimposed on highly connected populations, sardines may be able to follow environmental optima and shift their distribution northwards as a response to the increasing sea surface temperatures.Fundação para a Ciência e Tecnologia - FCTinfo:eu-repo/semantics/publishedVersio

Food for Thought Integrating population genomics and biophysical models towards evolutionary-based fisheries management

Overfishing and rapid environmental shifts pose severe challenges to the resilience and viability of marine fish populations. To develop and implement measures that enhance species’ adaptive potential to cope with those pressures while, at the same time, ensuring sustainable exploitation rates is part of the central goal of fisheries management. Here, we argue that a combination of biophysical modelling and population genomic assessments offer ideal management tools to define stocks, their physical connectivity and ultimately, their short-term adaptive potential. To date, biophysical modelling has often been confined to fisheries ecology whereas evolutionary hypotheses remain rarely considered. When identified, connectivity patterns are seldom explored to understand the evolution and distribution of adaptive genetic variation, a proxy for species’ evolutionary potential. Here, we describe a framework that expands on the conventional seascape genetics approach by using biophysical modelling and population genomics. The goals are to identify connectivity patterns and selective pressures, as well as putative adaptive variants directly responding to the selective pressures and, ultimately, link both to define testable hypotheses over species response to shifting ecological conditions and overexploitation

Hydroxyapatite crystallinity does not affect the repair of critical size bone defects

OBJECTIVE: The physicochemical properties of hydroxyapatite (HA) granules were observed to affect the biological behavior of graft materials. The aim of this work was to analyze the tissue response of two HA granules with different crystallinity and Ca/P ratio in vivo. MATERIAL AND METHODS: The HA granules were produced in the Biomaterials Laboratory (COPPE/UFRJ). The testing materials were HA granules presenting a Ca/P molar ratio of 1.60 and 28% crystallinity (HA-1), and a Ca/P molar ratio of 1.67 and 70% crystallinity (HA-2). Both HAs were implanted into a critical-size calvaria rat defects. RESULTS: To note, in the control group, the bone defects were filled with blood clot only. Descriptive and histomorphometric analyses after 1, 3, and 6 months postoperatively showed mild inflammatory infiltrate, mainly comprising macrophage-like and multinucleated giant cells, and an increase in the volume density of the fibrous tissues (

Towards a unified eco-evolutionary framework for fisheries management: Coupling advances in next-generation sequencing with species distribution modelling

The establishment of high-throughput sequencing technologies and subsequent large-scale genomic datasets has flourished across fields of fundamental biological sciences. The introduction of genomic resources in fisheries management has been proposed from multiple angles, ranging from an accurate re-definition of geographical limitations of stocks and connectivity, identification of fine-scale stock structure linked to locally adapted subpopulations, or even the integration with individual-based biophysical models to explore life history strategies. While those clearly enhance our perception of patterns at the light of a spatial scale, temporal depth and consequently forecasting ability might be compromised as an analytical trade-off. Here, we present a framework to reinforce our understanding of stock dynamics by adding also a temporal point of view. We propose to integrate genomic information on temporal projections of species distributions computed by Species Distribution Models (SDMs). SDMs have the potential to project the current and future distribution ranges of a given species from relevant environmental predictors. These projections serve as tools to inform about range expansions and contractions of fish stocks and suggest either suitable locations or local extirpations that may arise in the future. However, SDMs assume that the whole population respond homogenously to the range of environmental conditions. Here, we conceptualize a framework that leverages a conventional Bayesian joint-SDM approach with the incorporation of genomic data. We propose that introducing genomic information at the basis of a joint-SDM will explore the range of suitable habitats where stocks could thrive in the future as a function of their current evolutionary potential.Fundação para a Ciência e Tecnollogia - FCT; ARNETinfo:eu-repo/semantics/publishedVersio

Caracterização físico-química de seis hidroxiapatitas comerciais para aplicações médico-odontológicas como material de enxerto

O objetivo desse trabalho foi caracterizar seis hidroxiapatitas granulares para aplicação em área médico-odontológica como material de enxerto. Estes materiais foram produzidos por quatro diferentes fabricantes e são todos facilmente disponíveis no mercado brasileiro. A caracterização físico-química foi realizada por meio de microscopia eletrônica de varredura, difração de raios-X, espectroscopia de infravermelho e área superficial específica (BET). Os resultados mostraram que apenas um dos produtos teve a caracterização perfeitamente de acordo com a especificação do fabricante. Os parâmetros de cristalinidade, área superficial e composição podem ser usados para estimar a biodegradabilidade da hidroxiapatita e como critério de controle de qualidade desses materiais.The aim of this work was to characterize six hydroxyapatites in granular form for applications in medicine and dentistry as bone graft and to compare with manufacturers' specification. These samples were produced by four different manufacturers, and all of them are easily available in the Brazilian market. Physicochemical characterization was carried out by using electron microscopy (SEM), X-ray diffraction (XRD), infrared spectroscopy (FTIR) and surface area (BET) measurements. The results show that just one hydroxyapatite sample exhibited characterisitics in perfect agreement with the manufacturers' specifications. The studied parameters, namely crystallinity, surface area and composition may be used to estimate hydroxyapatite's biodegradability and as a criterion for quality control