Trophic dynamics within a hybrid zone - interactions between an abundant cyprinid hybrid and sympatric parental species

1. Recent proliferation of hybridisation in response to anthropogenic ecosystem change, coupled with increasing evidence of the importance of ancient hybridisation events in the formation of many species, has moved hybridisation to the forefront of evolutionary theory.

2. In spite of this, the mechanisms (e. g. differences in trophic ecology) by which hybrids co-exist with parental taxa are poorly understood. A unique hybrid zone exists in Irish freshwater systems, whereby hybrid offspring off two non-native cyprinid fishes often outnumber both parental species.

3. Using stable isotope and gut content analyses, we determined the trophic interactions between sympatric populations of roach (Rutilus rutilus), bream (Abramis brama) and their hybrid in lacustrine habitats.

4. The diet of all three groups displayed little variation across the study systems, and dietary overlap was observed between both parental species and hybrids. Hybrids displayed diet, niche breadth and trophic position that were intermediate between the two parental species while also exhibiting greater flexibility in diet across systems.

Evolution of Antimicrobial Peptides to Self-Assembled Peptides for Biomaterial Applications

Biomaterial-related infections are a persistent burden on patient health, recovery, mortality and healthcare budgets. Self-assembled antimicrobial peptides have evolved from the area of antimicrobial peptides. Peptides serve as important weapons in nature, and increasingly medicine, for combating microbial infection and biofilms. Self-assembled peptides harness a “bottom-up” approach, whereby the primary peptide sequence may be modified with natural and unnatural amino acids to produce an inherently antimicrobial hydrogel. Gelation may be tailored to occur in the presence of physiological and infective indicators (e.g. pH, enzymes) and therefore allow local, targeted antimicrobial therapy at the site of infection. Peptides demonstrate inherent biocompatibility, antimicrobial activity, biodegradability and numerous functional groups. They are therefore prime candidates for the production of polymeric molecules that have the potential to be conjugated to biomaterials with precision. Non-native chemistries and functional groups are easily incorporated into the peptide backbone allowing peptide hydrogels to be tailored to specific functional requirements. This article reviews an area of increasing interest, namely self-assembled peptides and their potential therapeutic applications as innovative hydrogels and biomaterials in the prevention of biofilm-related infection.

Effects of Elodea nuttallii on temperate freshwater plants, microalgae and invertebrates: small differences between invaded and uninvaded areas

The invasive aquatic plant species Elodea nuttallii could pose a considerable risk to European freshwater ecosystems based on its current distribution, rate of spread and potential for high biomass. However, little research has been conducted on the impacts of this species on native biota. This study takes an ecosystem-wide approach and examines the impact of E. nuttallii on selected physicochemical parameters (dissolved oxygen and pH), algae, invertebrate and macrophyte communities. Elodea nuttallii had small but significant impacts on plant, invertebrate and algal species. The richness of algal periphyton was lower on E. nuttallii than on native macrophytes. The taxonomic composition of invertebrate communities associated with E. nuttallii differed from that associated with similar native plant species, but did not differ in terms of total biomass or species richness. Macrophyte species richness and total cover were positively correlated with percentage cover of E. nuttallii. Not all macrophyte species responded in the same way to E. nuttallii invasion; cover of the low-growing species, Elodea canadensis and charophytes were negatively correlated with E. nuttallii cover, whilst floating-rooted plants were positively correlated with E. nuttallii cover. All observed differences in the macrophyte community were small relative to other factors such as nutrient levels, inter-annual variation and differences between sites. Despite this, the observed negative association between E. nuttallii and charophytes is a key concern due to the rarity and endangered status of many charophyte species.

Assessment of the genetic diversity of the pinewood nematode, Bursaphelenchus xylophilus, in Portugal

O nemátode da madeira do pinheiro (NMP), Bursaphelenchus xylophiius, tem uma extensa distribuição na América do Norte, e encontra-se atualmente distribuído ao longo da maioria dos territórios de Canadá e dos Estados Unidos. Durante o último século, esta espécie foi transportada pelo Homem para outras regiões do mundo (não-nativas), associadas com o comércio e o fluxo global de produtos de origem florestal. Atualmente, esta espécie invasiva está reportada para algumas regiões do SE asiático (China, Japão, Coreia e Taiwan) e mais recentemente para a Europa (Portugal). Devido ao impacto que este organismo agente da doença da murchidão dos pinheiros causa nas florestas nativas destas regiões esta espécie assume uma elevada importância económica a nível mundial Em Portugal, a distribuição do NMP encontra-se confinada a uma área restrita e limitada (500 000 ha), a sul de Lisboa (península de Setúbal); contudo, constitui uma das maiores ameaças às florestas de pinheiro do país e da UE. Ate recentemente, nenhum consenso existia quanto à origem do NMP em Portugal. Diversas hipóteses têm sido colocadas para explicar esta introdução, nomeadamente a partir de zonas onde o nematode ocorre naturalmente (América do Norte), ou de outras áreas (não-nativas) onde o nematode se comporta como uma espécie invasiva (Leste da Ásia). A fim de avaliar a variabilidade genética do NMP proveniente da área afetada em Portugal, foram utilizadas várias técnicas moleculares, designadamente o random amplified polymorphic DNA (RAPD-PCR) e o satellite DNA (satDNA). No caso do RAPD-PCR, foram utilizados 24 isolados do NMP provenientes de Portugal, 1 proveniente da América do Norte e 1 da Ásia, tendo sido utilizado como out-group um isolado de B. mucronatus. A partir dos 28 RAPD primers utilizados obtiveram-se 640 fragmentos. No caso do satDNA, foram utilizados 21 isolados do NMP provenientes de Portugal, obtendo-se no total 206 sequências da família MspI. Ambos os métodos revelaram uma elevada similaridade genética entre os vários isolados do NMP da área afetada em Portugal O nível reduzido de diversidade genética obtido entre os isolados portugueses do NMP, permite concluir que se trata de uma única introdução deste organismo em Portugal, e proveniente de uma região asiática. A inexistência de uma de correlação entre a variabilidade genética e a distribuição geográfica do NMP dentro da área afetada em Portugal, indica que o NMP se encontra distribuído de forma uniforme ao longo de toda a área afetada, provavelmente relacionado com a distribuição e a expansão natural do inseto vector. The pinewood nematode (PWN), Bursaphelenchus xylophilus, has a wide distribution in North America, and is present throughout most of the territories of Canada and the United Stata. During the last century, this species has been transported by man to several non-native regions of the world, associated with trade and the global flow of forest products. Up to date, this invasive species has been reported from Asia (PR China, Japan, Korea and Taiwan) and more recently in Europe (Portugal). Due to the impact on native pine forests of these regions, this nematode species, the causal agent of pine wilt disease, is of great economic importance worldwide. In Portugal, the distribution of the PWN has been constrained to a relatively small area (500 000 ha) in the south of Lisbon (Setúbal Peninsula); however, it has become the most serious threat to pine forests in the country. Until recently, no consensus had emerged on the possible pathway of the PWN introduction in Portugal. Several hypotheses have been put forward to explain this introduction, such as an origin from endemic areas where the nematode naturally occurs (North America), or non-endemic areas where the nematode behaves as an exotic pest (East Asia). Random amplified polymorphic DNA (RAPD-PCR) and satellite DNA (satDNA) techniques were used in order to assess the level of genetic variability and genetic relationships, among several isolates of the PWN, representative of the entire affected area in Portugal. In the case of RAPD-PCR, 24 Portuguese isolates, plus two additional isolates of B. xylophilus, representing North America and East Asia were included. B. mucronatus was used as an out-group. Twenty-eight random primers generated a total of 640 DNA fragments. With satDNA, 206 Mspl sequence repeats were obtained from 21 Portuguese isolates of B. xylophilus. Both molecular methods revealed a high genetic similarity among the Portuguese isolates, and the low level of genetic diversity strongly suggests that they were dispersed recently from a single introduction, and from East Asia. The lack of apparent relationship between the genetic variability and the geographic distribution of the PWN within the affected area, suggests that the recent introduction of this pest (and pathogen) in Portugal has been uniformly distributed since its establishment, probably following the natural distribution and expansion of the insect vector.

A alga invasora Sargassum muticum e as macrófitas nativas do Sul de Portugal

Dissertação de Mestrado, Biologia Marinha, Faculdade de Ciências do Mar e do Ambiente, Universidade do Algarve, 2007

English as a lingua Franca : bridging the gap between theory and practice in english language teaching

Tese de doutoramento, Linguística (Linguística Aplicada), Universidade de Lisboa, Faculdade de Letras, 2015

A Community-Level, Mesoscale Analysis of Fish Assemblage Structure in Shoreline Habitats of a Large River Using Multivariate Regression Trees.

The mesoscale (100–102 m) of river habitats has been identified as the scale that simultaneously offers insights into ecological structure and falls within the practical bounds of river management. Mesoscale habitat (mesohabitat) classifications for relatively large rivers, however, are underdeveloped compared with those produced for smaller streams. Approaches to habitat modelling have traditionally focused on individual species or proceeded on a species-by-species basis. This is particularly problematic in larger rivers where the effects of biological interactions are more complex and intense. Community-level approaches can rapidly model many species simultaneously, thereby integrating the effects of biological interactions while providing information on the relative importance of environmental variables in structuring the community. One such community-level approach, multivariate regression trees, was applied in order to determine the relative influences of abiotic factors on fish assemblages within shoreline mesohabitats of San Pedro River, Chile, and to define reference communities prior to the planned construction of a hydroelectric power plant. Flow depth, bank materials and the availability of riparian and instream cover, including woody debris, were the main variables driving differences between the assemblages. Species strongly indicative of distinctive mesohabitat types included the endemic Galaxias platei. Among other outcomes, the results provide information on the impact of non-native salmonids on river-dwelling Galaxias platei, suggesting a degree of habitat segregation between these taxa based on flow depth. The results support the use of the mesohabitat concept in large, relatively pristine river systems, and they represent a basis for assessing the impact of any future hydroelectric power plant construction and operation. By combing community classifications with simple sets of environmental rules, the multivariate regression trees produced can be used to predict the community structure of any mesohabitat along the reach.

The Professional Legitimacy of the Taiwan-educated versus US-educated Taiwanese English Teachers

Thesis (Ph.D.)--University of Washington, 2015

Brain-Based Individual Difference Measures of Reading Skill in Deaf and Hearing Adults

Thesis (Ph.D.)--University of Washington, 2015

Urban development modifies lake food webs in the Pacific Northwest

Thesis (Master's)--University of Washington, 2015

Overproduction of the english definitive article by portuguese learners: a cross-sectional study

The English article system is actually so complex that it presents many challenges for most non-native learners of English. The main difficulty of Portuguese learners, despite the numerous similarities between the two article systems, is noticeable in a marked tendency to produce the definite article where native speakers of English would not use it. This article reports the results of a cross-sectional study which examined the English definite article overproduction by a group of 12 Portuguese EFL learners with at least seven years of English instruction. The prediction is that these learners will exhibit evidence of transferring L1 features to their interlanguage when they overuse the definite article. The data were collected by means of a gap-filling task and a composition. The results found, as predicted, that these learners overused the in generic contexts. It is argued that this overuse is directly tied to and can be explained by transfer to somewhere and conceptual transfer principles.

Metal ions and protein folding: conformational and functional interplay

Dissertation presented to obtain a PhD degree in Biochemistry at Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa

ESL students' off-line and on-line texts : differences and similarities /

This study was undertaken to investigate any textual differences and similarities within essays written with a word processing program and an e-mail editor by non-native writers. It arose from many contradictions and a paucity of empirical research within the field of second language learning and electronic technology. To further explore these contradictory observations, 3 classes of intermediate level ESL (English as a Second Language) students v^ote 6 essays, alternating between a word processing program and an e-mail editor. Prior to the data collection, students read brief texts and responded to questions that focused upon three formal topics: immigration, economics, and multiculturalism. Data were examined for (a) the differences in the frequency counts of 12 cohesive devices, (b) sentence complexity, which focused upon the occurrences of simple and complex sentences, (c) the number of words within the writings, (d) the method of contextualization preferred by writers, and (e) any variations in the final grades of the students' texts that resulted from holistic rating. Results of analysis indicated that there were no statistically significant differences in the frequency counts of the linguistic features. Sentence complexity did not vary within the off-line and on-line essays. The average number of words found within the off-line essays was approximately 20% greater than within on-line essays. Contextualization methods were not different within word-processed or e-mailed essays. Finally, there was no difference in the quality of the texts when holistically rated.

ESL Collections, University Libraries, and Internationalization

This research study examines the content, types of materials, locations, and library collection development policies concerning ESL (English as a second language) materials collections on university campuses in the United States and Canada. ESL learning materials are defined in this study as those materials supporting adult learners who are non-native speakers of English in a higher education setting. The purpose of this study is to describe the content and types of materials in these collections, to learn where these collections are typically housed on university campuses, to discover what collection development policies may inform the building of these collections, and to explore the potential significance of these collections for university libraries. The overriding question that informs this study is the following: Can involvement with ESL collections serve as a way for university libraries to participate in internationalization by supporting the language needs of international students?

L'impact de la Convention de la Baie-James et du Nord québécois sur la santé des Cris de l'Iiyiyiu Aschii

Objectif: La santé des Indiens inscrits est inférieure à celle des autres Canadiens et dévoile des écarts importants entre les différents groupes qui la composent. La nation crie de l’Iiyiyiu Aschii, signataire de la Convention de la Baie-James et du Nord québécois (CBJNQ), bénéficie à cet égard d’un état de santé supérieur à celui des autres Indiens inscrits. L’objectif de ce mémoire est d’examiner l’impact de la CBJNQ sur les déterminants sociaux et l’état de santé de ses signataires cris depuis son entrée en vigueur en 1977. Méthodologie : Des analyses comparatives entre les Cris de l’Iiyiyiu Aschii, les Indiens inscrits et les Canadiens ont permis de suivre l’évolution à travers le temps des différences socioéconomiques, d’habitudes de vie et d’état de santé de ces groupes. Résultats : Les Cris ont enregistré, comparativement aux autres groupes d’Indiens inscrits vivant sur une réserve, une plus grande amélioration de leurs déterminants socioéconomiques, une progression relativement limitée de leurs comportements à risque et une préservation à un niveau plus élevé de leurs pratiques traditionnelles. Les Cris ont également vu progresser plus rapidement leur espérance de vie à la naissance que les Canadiens, et leur mortalité infantile a connu une chute encore plus importante que celle enregistrée chez les Indiens inscrits sur réserve. Conclusion : La CBJNQ a vraisemblablement eu un impact significatif sur la santé des Cris de l’Iiyiyiu Aschii. Cette amélioration sanitaire s’explique notamment par la Convention qui a su mettre en place des structures politiques qui ont favorisé l’amélioration des déterminants sociaux et le développement de l’autonomie gouvernementale des Cris.