A scholar for all seasons : homenagem a João de Almeida Flor

Este volume, da iniciativa do Centro de Estudos Anglísticos da Universidade de Lisboa e do Departamento de Estudos Anglísticos da Faculdade de Letras de Lisboa, reúne um elevado número de contributos de colegas, familiares e amigos do Professor Doutor João de Almeida Flor, e pretende testemunhar, de uma forma simbólica, o reconhecimento da sua exemplar dedicação enquanto docente, dirigente e investigador. A diversidade e a profundidade dos seus interesses académicos, patentes no Curriculum Vitae incluído no volume, justificam o grande apreço e admiração que sempre suscitou em quem pôde acompanhar a sua carreira. Com efeito, o elevado nível intelectual do seu trabalho académico, quer na docência, quer na investigação, marcado pelo rigor e excepcional eloquência que sempre caracterizaram o seu magistério, deixam uma marca indelével em todos aqueles que tiveram o privilégio de ser seus alunos, orientandos e/ou seus colegas. Tendo dedicado boa parte da sua investigação e docência à literatura e à cultura inglesas, com especial destaque para as obras de poetas românticos e de William Shakespeare, a sua insaciável curiosidade intelectual encaminhou-o para muitas outras áreas do saber, nomeadamente para as literaturas românicas e para os estudos de tradução. De entre as publicações vindas a lume, para além de volumes, artigos e ensaios que abrangem as mais diversas áreas e denotam profundo e continuado labor reflexivo, sobressaem também as traduções, anotadas e prefaciadas, de textos de grandes poetas de língua inglesa. A notável sensibilidade estética e poética de João de Almeida Flor, aliada ao rigor de expressão e ao dom de oratória, confluíram na meritória tarefa de divulgação de textos de difícil acesso a um público mais alargado. Os seus vastos conhecimentos científicos permitiram-lhe orientar inúmeras dissertações de Mestrado e de Doutoramento, a que acresce a regular participação em júris, não apenas na Universidade de Lisboa, mas também noutras universidades do país, tendo também participado em colóquios e conferências nacionais e internacionais, com intervenções e comunicações que mereceram reconhecido destaque. Ainda no âmbito da investigação científica, para além de pertencer a várias e reputadas associações e instituições académicas, foi membro da Comissão Instaladora e Coordenador Científico do Centro de Estudos Anglísticos (CEAUL/ ULICES) desde 1986 até 2009. A ele se deve a dinamização e um zeloso acompanhamento das actividades deste Centro de Investigação que, ao longo dos anos, se foi afirmando pela qualidade das suas publicações e iniciativas. Sob a sua coordenação, o CEAUL/ULICES viria a atingir o grau de excelência reconhecido pela Comissão de Avaliação Externa em 2008. Dando actualmente continuidade à sua actividade como investigador neste Centro, João de Almeida Flor continua também a assumir tarefas de coordenação editorial — uma outra área a que se foi dedicando ao longo dos anos. Embora não seja fácil resumir, em poucas palavras, a extensão e a diversidade dos interesses, projectos e actividades constantes do seu Curriculum Vitae,impõe-se que apontemos ainda o elevado número de iniciativas no âmbito da extensão científica e cultural, bem como o seu relevante contributo para as actividades de administração escolar, não só enquanto dirigente do Departamento de Estudos Anglísticos, mas também em instâncias mais alargadas, dentro da Faculdade de Letras e da Universidade de Lisboa. Entre os múltiplos exemplos da sua participação activa e determinante no que respeita ao Departamento de Estudos Anglísticos, destaquemos a colaboração nas reformulações curriculares, assim como na elaboração dos Estatutos deste Departamento, a que mais recentemente se somou a participação na Assembleia Estatutária da Faculdade de Letras de Lisboa. Para concluir esta breve nota introdutória, coloquemos em palavras aquilo que é, certamente, o pensar e o sentir de todos nós: que a presença e o labor intelectual de João de Almeida Flor continuem a servir de exemplo e de motivação para o nosso próprio trabalho. E lembremos, a propósito, uma frase de Percy Shelley: “There is no real wealth but the labour of man”.Fundação para a Ciência e a Tecnologi

Population homogeneity for the antibody response to COVID-19 BNT162b2/Comirnaty vaccine is only reached after the second dose across all adult age ranges

ABSTRACT: While mRNA vaccines are administrated worldwide in an effort to contain the COVID-19 pandemic, the heterogeneity of the humoral immune response they induce at the population scale remains unclear. Here, in a prospective, longitudinal, cohort-study, including 1245 hospital care workers and 146 nursing home residents scheduled for BNT162b2 vaccination, together covering adult ages from 19 to 99 years, we analyse seroconversion to SARS-CoV-2 spike protein and amount of spike-specific IgG, IgM and IgA before vaccination, and 3-5 weeks after each dose. We show that immunogenicity after a single vaccine dose is biased to IgG, heterogeneous and reduced with increasing age. The second vaccine dose normalizes IgG seroconversion in all age strata. These findings indicate two dose mRNA vaccines is required to reach population scale humoral immunity. The results advocate for the interval between the two doses not to be extended, and for serological monitoring of elderly and immunosuppressed vaccinees.info:eu-repo/semantics/publishedVersio

Mechanical, electrical and electro-mechanical properties of thermoplastic elastomer styrene–butadiene–styrene/multiwall carbon nanotubes composites

Composites of styrene-butadiene-styrene (SBS) block copolymer with multiwall carbon nanotubes (MWCNT) were processed by solution casting in order to investigate the influence of filler content, the different ratio of styrene/butadiene in the copolymer and the architecture of the SBS matrix on the electrical, mechanical and electro-mechanical properties of the composites. It was found that filler content and elastomer matrix architecture influence the percolation threshold and consequently the overall composite electrical conductivity. The mechanical properties are mainly affected by the styrene and filler content. Hopping between nearest fillers is proposed as the main mechanism for the composite conduction. The variation of the electrical resistivity is linear with the deformation. This fact, together with the gauge factor values in the range of 2 to 18, results in appropriate composites to be used as (large) deformation sensors.This work was funded by FEDER funds through the "Programa Operacional Factores de Competitividade – COMPETE" and by national funds by FCT - Fundação para a Ciência e a Tecnologia, through project references PTDC/CTM/69316/2006, PTDC/CTM/73465/2006, PTDC/CTM-NAN/112574/2009, and NANO/NMed- SD/0156/2007. PC, JS and VS also thank FCT for the SFRH/BD/64267/2009, SFRH/BD/60623/2009 and SFRH/BPD/63148/2009 grants, respectively. The authors also thank support from the COST Action MP1003 ”European Scientific Network for Artificial Muscles” and the COST action MP0902 “Composites of Inorganic Nanotubes and Polymers (COINAPO)

Evaluation of toxicity after one-months treatment with Bauhinia forficata decoction in streptozotocin-induced diabetic rats

BACKGROUND: Previous experiments have shown that a decoction of Bauhinia forficata leaves reduces the changes in carbohydrate and protein metabolism that occur in rats with streptozotocin-induced diabetes. In the present investigation, the serum activities of enzymes known to be reliable toxicity markers were monitored in normal and streptozotocin-diabetic rats to discover whether the use of B. forficata decoction has toxic effects on liver, muscle or pancreas tissue or on renal microcirculation. METHODS: An experimental group of normal and streptozotocin-diabetic rats received an aqueous decoction of fresh B. forficata leaves (150 g/L) by mouth for 33 days while a control group of normal and diabetic rats received water for the same length of time. The serum activity of the toxicity markers lactate dehydrogenase, creatine kinase, amylase, angiotensin-converting enzyme and bilirubin were assayed before receiving B. forficata decoction and on day 19 and 33 of treatment. RESULTS: The toxicity markers in normal and diabetic rats were not altered by the diabetes itself nor by treatment with decoction. Whether or not they received B. forficata decoction the normal rats showed a significant increase in serum amylase activity during the experimental period while there was a tendency for the diabetic rats, both treated and untreated with decoction, to have lower serum amylase activities than the normal rats. CONCLUSIONS: Administration of an aqueous decoction of B. forficata is a potential treatment for diabetes and does not produce toxic effects measurable with the enzyme markers used in our study

Antagonistic Bacterial Interactions Help Shape Host-Symbiont Dynamics within the Fungus-Growing Ant-Microbe Mutualism

Conflict within mutually beneficial associations is predicted to destabilize relationships, and theoretical and empirical work exploring this has provided significant insight into the dynamics of cooperative interactions. Within mutualistic associations, the expression and regulation of conflict is likely more complex than in intraspecific cooperative relationship, because of the potential presence of: i) multiple genotypes of microbial species associated with individual hosts, ii) multiple species of symbiotic lineages forming cooperative partner pairings, and iii) additional symbiont lineages. Here we explore complexity of conflict expression within the ancient and coevolved mutualistic association between attine ants, their fungal cultivar, and actinomycetous bacteria (Pseudonocardia). Specifically, we examine conflict between the ants and their Pseudonocardia symbionts maintained to derive antibiotics against parasitic microfungi (Escovopsis) infecting the ants' fungus garden. Symbiont assays pairing isolates of Pseudonocardia spp. associated with fungus-growing ants spanning the phylogenetic diversity of the mutualism revealed that antagonism between strains is common. In contrast, antagonism was substantially less common between more closely related bacteria associated with Acromyrmex leaf-cutting ants. In both experiments, the observed variation in antagonism across pairings was primarily due to the inhibitory capabilities and susceptibility of individual strains, but also the phylogenetic relationships between the ant host of the symbionts, as well as the pair-wise genetic distances between strains. The presence of antagonism throughout the phylogenetic diversity of Pseudonocardia symbionts indicates that these reactions likely have shaped the symbiosis from its origin. Antagonism is expected to prevent novel strains from invading colonies, enforcing single-strain rearing within individual ant colonies. While this may align ant-actinomycete interests in the bipartite association, the presence of single strains of Pseudonocardia within colonies may not be in the best interest of the ants, because increasing the diversity of bacteria, and thereby antibiotic diversity, would help the ant-fungus mutualism deal with the specialized parasites

The Gaia-ESO Survey::the present-day radial metallicity distribution of the Galactic disc probed by pre-main-sequence clusters

Context. The radial metallicity distribution in the Galactic thin disc represents a crucial constraint for modelling disc formation and evolution. Open star clusters allow us to derive both the radial metallicity distribution and its evolution over time. Aims. In this paper we perform the first investigation of the present-day radial metallicity distribution based on [Fe/H] determinations in late type members of pre-main-sequence clusters. Because of their youth, these clusters are therefore essential for tracing the current interstellar medium metallicity. Methods. We used the products of the Gaia-ESO Survey analysis of 12 young regions (age < 100 Myr), covering Galactocentric distances from 6.67 to 8.70 kpc. For the first time, we derived the metal content of star forming regions farther than 500 pc from the Sun. Median metallicities were determined through samples of reliable cluster members. For ten clusters the membership analysis is discussed in the present paper, while for other two clusters (i.e. Chamaeleon I and Gamma Velorum) we adopted the members identified in our previous works. Results. All the pre-main-sequence clusters considered in this paper have close-to-solar or slightly sub-solar metallicities. The radial metallicity distribution traced by these clusters is almost flat, with the innermost star forming regions having [Fe/H] values that are 0.10−0.15 dex lower than the majority of the older clusters located at similar Galactocentric radii. Conclusions. This homogeneous study of the present-day radial metallicity distribution in the Galactic thin disc favours models that predict a flattening of the radial gradient over time. On the other hand, the decrease of the average [Fe/H] at young ages is not easily explained by the models. Our results reveal a complex interplay of several processes (e.g. star formation activity, initial mass function, supernova yields, gas flows) that controlled the recent evolution of the Milky Way