Soil Microbial Biomass And Activity In A Cork Oak Savanna

Cork oak savannas are composed by a sparse tree canopy (30-70 trees/ha) and a grassland understory predominantly composed of C3 annuals that survive the hot and dry Mediterranean summers as seeds in the soil. Microbial communities can be more or less efficient at converting organic substrates into microbial biomass carbon depending on the quantity and quality of organic matter inputs. The cork oak savannas have two distinct types of plant litter that can affect soil microbial biomass and activity differently: herbaceous litter and the more recalcitrant woody plant litter resulting from the trees. Spatial variability of soil microbial biomass and activity due to the tree-grassland component of cork oak savannas were evaluated in order to better understand the soil carbon dynamics of these systems.

To quantify changes in soil microbial biomass and activity, measurements were performed in a Cork oak savanna in Southern Portugal. At this site 8 plots were randomly established under mature cork oak trees and paired with 8 open grassland plots. During one year soil cores (0-10 cm) were monthly collected at each site for measuring soil microbial biomass C and other eco-physiology parameters.


Results/Conclusion

Soil microbial biomass carbon (Cmic) and nitrogen (Nmic) were always higher under the tree canopy than in the open grasslands. Organic carbon (Corg) was also higher under the tree canopies. The Cmic/Corg ratio relates to the microbial activity and its potential to mineralize organic substances. The Cmic/Corg ratio was lower under the tree canopies than in the open grasslands. Less microbial biomass was supported per unit of Corg. Basal activity was always higher under the canopy than in the open grassland.

Trees scattered in the savanna function as islands inducing larger soil microbial communities and higher basal activity under the canopies. Lower Cmic/Corg ratio under the tree canopies suggests a more recalcitrant nature of the litter and a decrease in relative availability of organic matter under the trees.
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Physical Connectivity Between the NE Atlantic Seamounts

Within the Portuguese Exclusive Economic Zone, the Great Meteor and Madeira-Tore complexes are highly productive areas, which are likely to be classified as marine protected areas (MPAs) due to their ecological vulnerability. This was the main focus of the BIOMETORE project and, framed on it, the aim of the present study was to investigate the physical connectivity between both seamount complexes. Using the HYbrid Coordinate Ocean Model coupled with the Connectivity Modeling System (CMS) (a Lagrangian tool), a series of experiments was conducted in order to determine the influence of the main oceanographic phenomena governing the area in: (i) the origin of the particles that reach each complex, (ii) their capacity to capture and retain incoming particles, and (iii) the physical connectivity between them as well as the intra-connectivity within each seamount system. Due to the geographical location of both groups of seamounts, the Azores Current (AzC) and its associated eddies were identified as the main transport pathways, its influence being stronger at intermediate waters and decreasing with depth. Notwithstanding, the Great Meteor and the MadeiraTore were mainly affected by the AzC southward and eastward branches, respectively, resulting in a non-significant connectivity between the two groups. Meanwhile, the inter-connectivity between seamounts slightly varied with depth at the Great Meteor complex while increasing at Madeira-Tore. In addition, the Plateau, Irving, and Cruiser (PIC) seamounts from the Great Meteor complex and Gorringe and Coral from the Madeira-Tore complex proved to incorporate the regional connectivity routes. Although containing the three smallest seamounts, Madeira-Tore showed the higher capturing capacity per square kilometer, highlighting the influence of the "sticky water effect." In the Great Meteor complex, the "seamount effect" seems to be the main phenomenon responsible for the greater retention and self-recruitment abilities of these seamounts. The presented results provide valuable information for the design of a MPA to preserve these vulnerable habitat

Potential utilization of orange juice industrial production’s residues for the immobilization of metals in contaminated soils

Mestrado em Engenharia Agronómica - Hortofruticultura e Viticultura / Instituto Superior de Agronomia. Universidade de LisboaSoil contamination with potentially toxic elements (metals and metalloids) may affect the crops in several undesirable ways, and, consequently, the human food chain. The use of organic amendments to treat the contaminated soil is a possibility that cannot be excluded and thus must be taken into account when addressing this problem, since the organic matter has a sequestration potential for metals and, additionally, has the possibility to improve the physical, chemical, and biological properties of the amended soil. The application doses of the residue evaluated equivalent to 20 and 40 t/ha were not reflected in a significant variation of the OM content in both-contaminated and non-contaminated soils, contrarywise to what was verified in the application of orange residues in a rate of 80 t/ha, which evidenced significant differences when in comparison with the non-treated samples, in both contaminated and non-contaminated soils. Concerning the pH of the soils, in the non-contaminated soil only the highest rate application registered statistical differences when in comparison with the non-treated evidence, whereas for the contaminated soil none of the application rates registered significant differences. The obtained results showed that the application of orange juice residues caused significant differences in the pseudo-total and bioavailable contents of Cu but not of Cd, in both contaminated and non-contaminated soil. However, the Cd bioavailable contents are not considered high, varying between 5.67% and 6.45% of total Cd content. Further experiments should be made in order to assess the effects that higher doses of residue can produce in the bioavailable quantities of Cd, and also to evaluate how the application of the orange juice residues can influence the extractability of other potentially toxic elements, as well as validate the possibility of using this method to the remediation of soils in a real situation under non-controlled circumstancesN/

How can commercial media literacy change the influence of product placement on children

Field lab in marketingPurpose - The goal of this research is to analyze how the introduction of commercial media literacy programs can reduce the influence of product placement on children by giving them tools to easily identify it and understand its persuasive intent. Methodology - An experimental design with 147 children was performed, in order to compare if children that had a class about product placement were less influenced by it and could better identify its presence and understand its purpose. Findings - Results suggest that commercial media literacy is indeed effective mitigating some effects of product placement on children, since it contributed to decrease children’s preference for the placed brand. Moreover, it increased their understanding of the advertisements’ persuasive intent and product placement awareness on TV shows. Research Limitations – Further research should include children from other countries and ages. The medium and long-term effects should be analyzed as well. Besides, a longer intervention could be performed. Value – Previous research had already found that product placement is very effective in influencing children’s consumer behaviors due to their vulnerability. Nonetheless, this is the first study that seeks to solve this problem and overcomes the existing literature gap concerning the effectiveness of commercial media literacy on mitigating the effect of this subtle type of advertisement

Algorithms for infinite session types

Tese de Mestrado, Mestrado em Informática, 2022, Universidade de Lisboa, Faculdade de CiênciasIn concurrent interactions there are a large number of messages exchanged between two or more processes that often lead to coding errors. To simplify these interactions and reduce the coding errors, session types were created. Session types are an approach for structuring interaction protocols between multiple parties. When a channel is shared between two processes it is necessary to ensure that if one is sending a message, the other is prepared to receive it. In the same way, if a process offers some options, the complementary is prepared to select one of the options. There are finite types of messages, that perform an operation and stop, where you can perform send/receive or offer/select a message and terminate the interaction. However, not all of the interactions are possible just with finite types. This work presents an extension of session types into infinity, since it is necessary to study different classes of types with greater expressive power than finite types. Recursive and 1-counter types are the main focus of this thesis. We start by designing grammars so we can test equation systems based on those types. Defining rules in which the systems of these types can be written is the purpose of the grammars. These rules include the possibility of sending or receiving messages and selecting or offering a set of options. The grammars are implemented based on SePi, a concurrent programming language based on pi-calculus. All the systems that present a finite and infinite behavior should be tested. Constructing algorithms for type formation and type equivalence of these systems as well as testing those algorithms is the main goal of this project, so that we can be sure that infinite types, specifically, with different degrees of expressivity are correctly defined and able to be compared

The news impact curve: An analysis of dollar denominated credit markets

Financial asset prices mirror investors’ expectations and risk perception, which translate into volatility. This volatility, or investment risk, is a key part of the investment decision and has been the target of several studies for several asset classes throughout the years. This study aims to determine if the conditional volatility of credit markets in dollars can be modelled, and if so, if it can be explained by external regressors. Building on existing frameworks, several ARCH type structures will be tested, including those which allow for leverage and asymmetry effects. Monthly returns of the Bloomberg Barclays Investment Grade USD index are going to be analysed and fitted, and the external variables used, based on literature review, include macroeconomic releases, macro prudential indicators and general news flow that can induce uncertainty, and therefore volatility. For the later, the EPU index will be used as a proxy. Analysis of the modelled structures conclude that it is possible to model conditional volatility using the aforementioned variables, with an EGARCH model. Further research is recommended to explore interest rate and excess returns components’ isolated response to these variables, which could strengthen the model.Os preços dos ativos financeiros refletem as expectativas e a perceção de risco dos investidores, o que se traduz em volatilidade. Essa volatilidade, ou risco associado ao investimento, é uma parte essencial da decisão de investimento e tem sido alvo de vários estudos para as diversas classes de ativos ao longo dos anos. Este estudo tem como objetivo determinar se a volatilidade condicional dos mercados de crédito em dólares pode modelizada e, em caso afirmativo, se pode ser explicada por regressores externos. Com base em modelos existentes, várias estruturas do tipo ARCH serão testadas, incluindo aquelas que efetivamente apreendem o efeito de alavancagem e assimetria. Os retornos mensais do índice Bloomberg Barclays Investment Grade USD serão analisados e ajustados a estas estruturas, e as variáveis externas utilizadas, com base na revisão da literatura, incluem dados macroeconómicos, indicadores macro prudenciais e notícias do espectro geral que podem induzir incerteza e, consequentemente, volatilidade. Para estas últimas será utilizado como proxy o índice EPU. A análise dos diversos modelos permite inferir que é possível modelar a volatilidade condicional usando as variáveis supramencionadas com um modelo EGARCH. Estudos futuros neste âmbito deverão explorar a resposta isolada das duas componentes dos índices de crédito, a taxa de juro e o excesso de retorno, a essas variáveis, o poderia fortalecer o modelo

Workshop em Ciências da Terra e do Espaço - Livro de Atas

O presente livro foi produzido no âmbito da unidade curricular Seminário do programa de Doutoramento em Ciências da Terra e do Espaço (DCTE) e do Mestrado em Ciências da Terra, da Atmosfera e do Espaço (MCTAE), que incluiu a organização da edição de 2018 do Workshop em Ciências da Terra e do Espaço da Universidade de Évora (WCTE2018). Neste volume estão reunidos os artigos de investigação produzidos pelos estudantes que frequentam a referida unidade curricular. O WCTE assume-se, desde a sua primeira edição em 2013, como um espaço de partilha de conhecimento e treino de comunicação em ciência. Nesse sentido, procura proporcionar aos estudantes que frequentam a Unidade de Seminário uma experiência efetiva não apenas na preparação e apresentação de comunicações orais e artigos de investigação, mas também na organização do próprio evento. Na edição do WCTE2018, que ocorreu no dia 10 de janeiro, foram submetidos e apresentados 9 trabalhos, que abrangem as várias temáticas que dos cursos MCTAE e DCTE

(UN)RECONCILED SELVES: AMERICAN BORN CHINESE THROUGH THE LENS OF DU BOISIAN THOUGHT

Gene Luen Yang’s graphic novel, American Born Chinese, has entered the syllabus of several North American classrooms as a starting point for discussions on racial stereotyping and identity formation. Despite having been compared to how African American authors explore the consequences of negative stereotyping, critics of Yang’s work have directed their attention mostly towards the reality of members from the Asian American community. Yet, this article aims at comprehending how the concepts of “double consciousness” and “two-ness” developed by W.E.B. Du Bois in The Souls of Black Folk (1903) can be used in order to better understand the experience of contemporary Chinese American youths as it has been represented in American Born Chinese. By utilizing Du Bois’s understanding of the psychological impacts of negative stereotyping on his black subjects this work argues that a parallel can be drawn between this African American author’s theory of split consciousness, together with its resulting feeling of otherness, and several narrative elements of Yang’s graphic novel, as well as its tripartite structure. Furthermore, it also examines how both authors present their readers with similar solutions in order for conflicting selves to achieve a state of undivided self-consciousness

O jogo na aprendizagem matemática

A comunicação no âmbito da Educação Infantil pretende sensibilizar as escolas de formação e os educadores para o papel de mediação na promoção do conhecimento matemático. Os materiais manipulativos na prática educativa são facilitadores duma aprendizagem significativa, quando aliam o sentido lúdico ao jogo. Através de atividades diversificadas surgem como recurso metodológico, em que a criança explora, experimenta, deduz, comunica, ultrapassa o erro, agiliza o raciocínio, fazendo a “ponte” entre o concreto e o abstrato. Com o objetivo de analisarmos a importância do jogo aplicámos um questionário a 942 crianças de 5 anos das escolas João de Deus, para sabermos como brincam e quais as atividades preferidas. Os resultados sugerem que o lúdico, o jogo e a matemática poderiam estar mais ligados aos objetivos da formação e às atividades de aprendizagem, permitindo às crianças a aquisição de capacidades percetivas, representativas e conceptuais e mais conquistas cognitivas, emocionais e sociais

Criatividade, autoconceito e rendimento escolar em alunos do ensino básico

Disponível em: Veiga, F. & Caldeira, M. (2006). Criatividade, autoconceito e rendimento escolar em alunos do ensino básico In Santos, N., Lima, M. L., Melo, M. M., Candeias, A., Grácio, M. L., & Calado, A. (orgs.). Livro de Actas do VI Simpósio Nacional de Investigação em Psicologia (pp. 77-97). Évora, Portugal. ISBN: 978-972-98136-9-6Com este estudo pretendeu-se estudar como se relacionam a criatividade, o autoconceito e o rendimento escolar em alunos do ensino básico. A amostra foi constituída por 350 alunos de do 6º e do 9º anos de escolaridade, de escolas da Grande Lisboa e do distrito de Faro, englobando sujeitos dos dois sexos e de diferentes nacionalidades. Para a avaliação do autoconceito académico recorreu-se ao Self-Concept as a Learner Scale, já adaptada para Portugal. A criatividade foi avaliada com o instrumento denominado Torrance Tests of Creative Thinking. A análise dos resultados permitiu observar, em variadas situações, diferenças significativas nas dimensões das atitudes dos alunos face a si mesmos em função da criatividade, com superiores resultados nos alunos vistos como criativos, verificando-se, ainda, correlações esperadas entre os valores da criatividade e do rendimento escolar. Os resultados foram interpretados numa perspectiva cognitivo-social e sugerem novas investigações acerca das dimensões da riatividade e de variáveis específicas, quer pessoais quer escolares