9 documents found, page 1 of 1
Evolution of Escherichia coli strains under competent or compromised adaptive i...
Ameline, Camille; Seixas, Elsa; Barreto, Hugo C.; Frazão, Nelson; Rodrigues, Miguel V.; Ventura, M. Rita; Lourenço, Marta; Gordo, IsabelEscherichia coli is a commensal of the intestine of most mammals, but also an important human pathogen. Within a healthy human its population structure is highly dynamic, where typically a dominant E. coli strain is accompanied by several low abundance satellite strains. However, the factors underlying E. coli strain dynamics and evolution within hosts are still poorly understood. Here, we colonised germ-free i...
Fora do radar até agora: A conservação do património e das coleções científicas
Lourenço, MartaQue eu saiba, este é o primeiro volume dedicado a coleções científicas numa revista de conservação, algo que não posso deixar de agradecer ao anterior diretor da Conservar Património, António João Cruz, e à atual diretora, Elin Figueiredo. O facto de serem apenas quatro artigos não significa que a problemática seja escassa ou desinteressante, mas apenas que estamos na infância da arte. Espero que estes quatro a...
Astronomical Observatory of the Lisbon Polytechnic School: Virtual models for i...
Cláudio, Ana Paula; Redweik, Paula; Carmo, Maria Beatriz; Lourenço, Marta; Matos, António P.The Astronomical Observatory of the Lisbon Polytechnic School is the last teaching observatory of historical interest in Portugal. Created in the late nineteenth century, it survives intact in its original design. Given its singularity in the context of scientific heritage, the quality and beauty of its architecture, as well as its privileged location in the Botanical Garden, the Observatory has the potential t...
The contribution of Vital Brazil to tropical medicine: from poisoning to the sp...
Lira-da-Silva, Rejâne M.; Lourenço, Marta; Bochner, Rosany; Vital Brazil, Érico; Kobler Brazil, Tania; Ribeiro da Cunha, Luís EduardoVital Brazil Mineiro da Campanha (1865-1950) is known for his discovery, which to this day saved thousands of lives: the specificity of antiophidic sera. This article is part of the celebrations of the 150th anniversary of Vital Brazil, in order to present and discuss their contributions to Brazilian and international Tropical Medicine, for the study of poisonings by venomous animals and the discovery of specif...
Recurrent Reverse Evolution Maintains Polymorphism after Strong Bottlenecks in ...
Sousa, Ana; Ramiro, Ricardo S.; Barroso-Batista, João; Güleresi, Daniela; Lourenço, Marta; Gordo, IsabelThe evolution of new strains within the gut ecosystem is poorly understood. We used a natural but controlled system to follow the emergence of intraspecies diversity of commensal Escherichia coli, during three rounds of adaptation to the mouse gut (∼1,300 generations). We previously showed that, in the first round, a strongly beneficial phenotype (loss-of-function for galactitol consumption; gat-negative) sprea...
A Mutational Hotspot and Strong Selection Contribute to the Order of Mutations ...
Lourenço, Marta; Ramiro, Ricardo S; Güleresi, Daniela; Barroso-Batista, João; Xavier, Karina B; Gordo, Isabel; Sousa, AnaThe relative role of drift versus selection underlying the evolution of bacterial species within the gut microbiota remains poorly understood. The large sizes of bacterial populations in this environment suggest that even adaptive mutations with weak effects, thought to be the most frequently occurring, could substantially contribute to a rapid pace of evolutionary change in the gut. We followed the emergence o...
Investigating population structure of sea lamprey (Petromyzon marinus, L.) in w...
Lança, Maria João; Machado, Maria; Mateus, Catarina S.; Lourenço, Marta; Ferreira, Ana Filipa; Quintella, Bernardo R.; Almeida, Pedro R.This study hypothesizes the existence of three groups of sea lamprey Petromyzon marinus L. in Portugal (North/Central group, Tagus group, and Guadiana group), possibly promoted by seabed topography isolation during the oceanic phase of the life cycle. Within this context, our purpose was to analyze the existence of a stock structure on sea lamprey populations sampled in the major Portuguese river basins using b...
O Observatório Astronómico da Escola Politécnica : modelos virtuais para a sua ...
Cláudio, Ana Paula; Redweik, Paula; Carmo, Maria Beatriz; Lourenço, Marta; Matos, António P.O último observatório de ensino de interesse histórico em Portugal, que data do final do século XIX, é um dos edifícios mais carismáticos dos Museus da Universidade de Lisboa. Após um século de uso intensivo, o Observatório Astronómico da Escola Politécnica necessita de obras estruturais antes de ser devolvido integralmente à fruição pública. Recentemente, um grupo de estudantes desta Universidade foi envolvido...
Lipid composition and nutritional value of some meats with Protected Designatio...
Prates, José A. M.; Ribeiro, Verónica; Quaresma, Mário; Lourenço, Marta; Martins, Susana; Alves, Susana; Portugal, Ana; Castro, MatildeThe aim of this work was to characterise and compare the lipid cQmposition (lípid and eholcsterol contents, fatty acid composition and conjugated linoleie acid isomers) and nutritiona! value (PUFA/SFA and n-6/n-3 ratios) of four Portuguese mea!s with Protceted Designation of Origin (POO; Camalentejana-PDO beel: Mertolenga-POO beef, Barrosã-POO veal and Arouquesa-POO veal), in 1\\'0 distinct slaughter seasoos (e...