Abstract This study evaluated the effect of aging and cementation of fiber posts using glass ionomer and resin cements on push-out bond strength, failure mode, and resin tag formation. One hundred and twenty bovine incisors were used. After post-space preparation, the specimens were randomly allocated into 12 groups (n = 10) according to the cementation system used: GC - GC Gold Label Luting & Lining); RL - RelyX Luting 2; MC - MaxCem Elite; RU - RelyX U200 and the aging periods (24 hours, 6 months, and 12 months). Slices from the cervical, middle, and apical thirds were obtained and analyzed by push-out bond strength test and confocal laser scanning microscopy. One-way ANOVA and Tukey’s post-hoc test was used at a significance level of 5%. For the push-out bond strength test, no differences among GC, RU, and MC in the cervical and middle thirds were observed, regardless of the period of storage (P > 0.05). In the apical third, GC and RU showed similar bond strength but higher than other groups (P > 0.05). After 12 months, GC showed the highest bond strength (P < 0.05). Bond strength to post-space dentin decreased over time, regardless of the cementation system used. Cohesive failure was the most frequent, regardless of the period of storage, cementation system, and post-space third. Tag formation was similar among all groups. After 12 months, GC showed the highest bond strength values.

Resumo Avaliar o efeito do envelhecimento e sistemas de cimentação usando ionômero de vidro e cimentos resinosos na resistência de união à dentina após a cimentação do pino de fibra. Cento e vinte incisivos bovinos foram utilizados. Após o preparo do pós-espaço, os corpos de prova foram distribuídos aleatoriamente em 12 grupos (n = 10) de acordo com o período de envelhecimento (24 horas, 6 meses e 12 meses) e o sistema de cimentação utilizado: GC - cimento de ionômero de vidro (GC Gold Label Cimentação e Revestimento); RL - RelyX Luting 2; MC - MaxCem Elite; RU - RelyX U200. Cortes dos terços cervical, médio e apical foram obtidos e analisados por teste de resistência de união push-out e microscopia confocal de varredura a laser. ANOVA one-way e teste de Tukey foi usado a um nível de significância de 5%. Para o teste de resistência de união, não foram observadas diferenças entre GC, RU e MC nos terços cervical e médio, independentemente do período de armazenamento (P > 0,05). No terço apical, GC e RU apresentaram resistência de união semelhante, porém superior aos demais grupos (P > 0,05). Após 12 meses, o GC apresentou a maior resistência de união (P < 0,05). A resistência de união à dentina no espaço para pino diminuiu ao longo do tempo, independentemente do sistema de cimentação utilizado. A formação de tags foi semelhante entre todos os grupos. Após 12 meses, o GC apresentou os maiores valores de resistência de união.

ABSTRACT Idiopathic pulmonary arterial hypertension (PAH) patients with a positive response to acute vasodilator challenge and a clinical response to calcium channel blockers (CCBs) for at least one year are traditionally designated true responders. Nevertheless, little is known about a sustained response to CCBs over longer periods of time. We evaluated the loss of response to CCBs after long-term treatment in a cohort of idiopathic PAH patients previously classified as being true responders. Our data suggest that idiopathic PAH patients can lose clinical response to CCBs even after one year of clinical stability, reinforcing the need for constant multidimensional reevaluation to assess the need for targeted PAH therapies and to classify these patients correctly.

RESUMO Pacientes com hipertensão arterial pulmonar (HAP) idiopática com resposta positiva ao teste de vasorreatividade aguda e resposta clínica a bloqueadores dos canais de cálcio (BCC) durante no mínimo um ano são tradicionalmente denominados “respondedores verdadeiros”. No entanto, pouco se sabe sobre a manutenção da resposta a BCC durante períodos mais longos. Avaliamos a perda de resposta a BCC após tratamento prolongado em uma coorte de pacientes com HAP idiopática previamente considerados respondedores verdadeiros. Nossos dados sugerem que pacientes com HAP idiopática podem deixar de apresentar resposta clínica a BCC mesmo depois de um ano de estabilidade clínica, reforçando a necessidade de reavaliação multidimensional constante para avaliar a necessidade de terapias específicas para HAP e classificar esses pacientes corretamente.

Abstract Objective To evaluate the effects of fluoride (F) gels supplemented with micrometric or nano-sized sodium trimetaphosphate (TMPmicro and TMPnano, respectively) on the in vitro remineralization of caries-like lesions. Methodology Bovine enamel subsurface lesions (n=168) were selected according to their surface hardness (SH) and randomly divided into seven groups (n=24/group): Placebo (without F/TMP), 4,500 ppm F (4500F), 4500F + 2.5% TMPnano (2.5% Nano), 4500F + 5% TMPnano (5% Nano), 4500F + 5% TMPmicro (5% Micro), 9,000 ppm F (9000F), and 12,300 ppm F (Acid gel). The gels were applied in a thin layer for one minute. Half of the blocks were subjected to pH cycling for six days, whereas the remaining specimens were used for loosely- (calcium fluoride; CaF2) and firmly-bound (fluorapatite; FA) fluoride analysis. The percentage of surface hardness recovery (%SHR), area of subsurface lesion (ΔKHN), CaF2, FA, calcium (Ca), and phosphorus (P) on/in enamel were determined. Data (log10-transformed) were subjected to ANOVA and the Student-Newman-Keuls’ test (p<0.05). Results We observed a dose-response relation between F concentrations in the gels without TMP for %SHR and ΔKHN. The 2.5% Nano and 5% Micro reached similar %SHR when compared with 9000F and Acid gels. For ΔKHN, Placebo and 5% Nano gels had the highest values, and 5% Micro, 2.5% Nano, 9000F, and Acid gels, the lowest. All groups had similar retained CaF2 values, except for Placebo and Acid gel. We verified observed an increase in Ca concentrations in nano-sized TMP groups. Regarding P, TMP groups showed similar formation and retention to 9000F and Acid. Conclusion Adding 2.5% nano-sized or 5% micrometric TMP to low-fluoride gels lead to enhanced in vitro remineralization of artificial caries lesions.

ABSTRACT. The main objective of our work was to survey the composition (richness and abundance) of birds in a forest remnant of the Atlantic Forest in Santa Catarina, southern Brazil, susceptible to the expansion of quarrying activities to support future analyzes of the environmental impacts. We recorded 142 bird species, distributed in 16 orders and 42 families. We propose that species richness shall not be affected by the expansion of quarrying into the remnant; however, we recorded that bird abundance was significantly lower near the forest edge than in the interior, especially of endemic, threatened and understory specialist species. Thus, if quarrying operation expands, we expect the bird abundance in adjacent forest remnants will be higher after species displacement, then will decrease over time as intra- and interspecific ecological relationships increase through competition for resources and territory. The size and quality of the remaining fragments are fundamental to reduce impacts of the activity and ensure the persistence of populations of sensitive and specialized birds in the region. For this reason, if the quarrying expands into the remnant area, then we propose that the surrounding forests be protected to ensure the migration and persistence of sensitive birds, mainly understory insectivores. In this context, we propose the following five actions to be implemented by the entrepreneur: 1) acquisition of surround remnants to be converted into Private Protected Areas, 2) reforestation equivalent to deforested area, 3) contribute to the National Action Plan for the Conservation of Atlantic Forest Birds through compensatory measures, 4) reduction of quarrying area, and 5) bird monitoring program.

RESUMO O principal objetivo do nosso trabalho foi o levantamento da composição (riqueza e abundância) da avifauna em um remanescente florestal de Mata Atlântica em Santa Catarina, suscetível à ampliação e intervenção de uma pedreira para subsidiar futuras análises de impactos ambientais dessa atividade. Registramos 142 espécies de aves, distribuídas em 16 ordens e 42 famílias. A partir dos resultados, concluímos que a riqueza total de espécies não deve ser afetada pela ampliação da área de lavra sob o remanescente. No entanto, constatamos que a abundância das aves foi menor nas proximidades da borda da mata, especialmente das aves endêmicas, ameaçadas e especialistas de sub-bosque. Dessa maneira, esperamos que a abundância nas áreas florestais adjacentes seja maior por um período, após o deslocamento das espécies, e diminua ao longo do tempo, à medida em que as relações ecológicas intraespecíficas e interespecíficas aumentem pela competição por recursos e território no habitat. Alertamos que se o tamanho do remanescente não for suficiente para populações viáveis, nossa hipótese é que haja um lapso temporal até que as espécies mais sensíveis desapareçam do local. O tamanho e qualidade do fragmento remanescente deve ser fundamental para minimizar os impactos da atividade e garantir a persistência das populações de aves sensíveis e especializadas na região. Por esse motivo, se a expansão da mina ocorrer, advertimos para que os remanescentes florestais do entorno sejam preservados para garantir a migração e persistência de aves sensíveis, principalmente insetívoras de sub-bosque relatadas em nosso estudo. Nesse contexto, apontamos cinco medidas prioritárias que devem ser implementadas pelo empreendedor, caso o órgão licenciador delibere em favor da ampliação/manutenção da atividade minerária: 1) aquisição dos remanescentes do entorno para transformá-los em RPPN, 2) reposição florestal equivalente à área desmatada, 3) contribuir com as ações do Plano de Ação Nacional para conservação das aves da Mata Atlântica por meio de medida compensatória, 4) diminuição da área de mina para exploração e 5) monitoramento de aves durante a instalação e operação do empreendimento.

Abstract The East Brazilian continental margin contains a large shelf sector called the Royal Charlotte Bank. It has terrigenous and carbonate sedimentation associated with coastal reefs. Studies using X-ray diffractometry (XRD) and the geochemistry of immobile elements were done in samples of these reefs to figure out the provenance of the mud that arrives there. In order to do this, samples of riverine sediment from the Jequitinhonha, Santo Antônio, João de Tiba, and Buranhém rivers as well as from the Barreiras Group’s sedimentary cliffs were taken. The Jequitinhonha River was found to be the most significant mud source. This was supported by the mineral fingerprints of smectite and biotite, the concentrations of immobile trace elements such as Zr, Hf, Nb, Ta, and Th, and the distribution and ratio of rare-earth elements. These findings are supported by the prevailing north-to-south drift that occurs in the region due to the northeasterly trade winds and waves that blow throughout the region for the vast majority of the year. The findings have significant implications for hydrographic basin management and the protection of reef benthic populations. Bank Xray X ray XRD (XRD there this Antônio Tiba Groups Group s taken source biotite Zr Hf Nb Ta Th rareearth rare earth northtosouth north south year populations

Resumo Muitos avanços ocorreram nas últimas décadas na terapêutica da hipertensão arterial pulmonar (HAP), uma doença grave, progressiva, incurável e potencialmente fatal. Para seu tratamento adequado, são fundamentais o diagnóstico hemodinâmico e a classificação de sua etiologia, em que várias delas (colagenoses, hipertensão portal, cardiopatia congênitas, esquistossomose) requerem medidas específicas, além do tratamento farmacológico característico para HAP. O tratamento com fármacos-alvo para HAP baseia-se em produtos farmacêuticos que interferem em três vias fisiopatológicas moleculares: da prostaciclina, da endotelina e do óxido nítrico. Tais fármacos apresentam múltiplas apresentações (oral, endovenosa, subcutânea e inalatória) e mudaram a história da HAP. Essas medicações e suas estratégias de uso, assim como particularidades das diferentes formas de HAP, são o foco desta revisão.

Abstract In the last decades, important advances have been made in the treatment of pulmonary arterial hypertension (PAH), a severe, progressive, incurable, and potentially fatal disease. For an adequate therapy, correct hemodynamic diagnosis and etiology classification are fundamental. Many etiologies – rheumatic disease, portal hypertension, congenital heart diseases, schistosomiasis – require specific measures, in addition to drug therapy for PAH. The specific therapy for PAH is based on medications that act on three pathophysiological pathways – prostacyclin, endothelin, and nitric oxide pathways. These drugs have multiple presentations (oral, intravenous, subcutaneous, and inhaled) and have changed the history of PAH. This review presents an overview of drug therapy strategies and different forms and peculiarities of PAH.

Abstract The Southern Lapwing (Vanellus chilensis) is a typical bird from southern Brazil, but it is widely dis- tributed across South America. It is well-recognized by its characteristic colors, imposing vocalization and aggressive behavior. The species inhabits grasslands, which can vary locally and regionally. The aim of this study is to evaluate how Southern Lapwings select their macro- and micro-habitats, which is necessary to better understand the species’ ecology, its relationship with the environment and the complex interaction between behavior and territory. This research intends to verify if there is any kind of selection for a specific environ ment and which factors influence the choice of feeding and breeding territories. Fieldwork was carried out at 40 ha in the state of Rio Grande do Sul, with 60 sampling points divided across six different vegetal formations. For macro-habitats, we analyzed data on availability and use of the area through the selection index, while for micro-habitat selection we constructed Generalized Linear Models (GLM) with the measures of environmental variables for each point. The selection index indicates that there is a strong preference for impacted grasslands, while lapwings seem to avoid forests and shrubland during both breeding and non-breeding seasons. The mi cro-habitat analysis indicates that the birds generally select areas with low vegetation height, and a certain degree of local human impact, but that the presence of farm animals is only preferred during the non-breeding season. This study shows that the Southern Lapwing can benefit from anthropic and altered environments, and it contributes to the understanding of this bird’s ecology and facilitates conservation measures.

RESUMO O quero-quero Vanellus chilensis (Molina, 1782) é uma ave típica do Estado do Rio Grande do Sul, mas possui ampla distribuição geográfica nos campos da América do Sul, sendo conhecido pelo canto imponente e pelos comportamentos relacionados com a agressividade e a territorialidade. Apesar de ser reconhecido como animal símbolo do estado, nenhum trabalho acerca dos comportamentos dessa ave foi desenvolvido no estado. Este trabalho teve como objetivo qualificar e quantificar o repertório comportamental de V. chilensis. Observações dos comportamentos dessa ave foram feitas em uma área de campo com oito hectares, no município de Torres, RS, entre dezembro de 2017 e novembro de 2018, totalizando 143 horas de observação. Utilizou-se a metodologia de observação de todas as ocorrências e observação de animal focal, coletando-se dados de frequência de ocorrência e duração de cada comportamento. Com os dados construiu-se um etograma. Registrou-se 23 comportamentos divididos em cinco categorias: locomoção, manutenção, alimentação, social-agonista e reprodução. Identificaram-se três formas de vocalização distintas em sonoridade, duração e ocasião, o que sugere diferentes funções para cada uma. As análises comprovaram a variação da maior parte dos comportamentos ao longo dos meses do ano, tanto em frequência como em duração. Constatou-se o aumento dos comportamentos sociais-agonistas e reprodutivos durante a estação reprodutiva, enquanto outras categorias como alimentação e manutenção apresentaram diminuição nesse período, havendo maior empenho dos animais na proteção dos ninhos e filhotes. O trabalho permitiu a caracterização dos comportamentos de V. chilensis no sul do Brasil, auxiliando no entendimento das relações entre espécie e ambiente típico da região.

ABSTRACT The Southern Lapwing Vanellus chilensis (Molina, 1782) is a common bird in Rio Grande do Sul state, south Brazil, but is widely distributed across South America. It inhabits grasslands and other open habitats and it is known by a distinctive black, grey, and white coloration, a conspicuous vocalization and both aggressive and territorial behaviors. Although being recognized as the bird symbol of Rio Grande do Sul, no study about its behavior has yet been carried out in the state. Here, we aimed to describe and quantify the behavioral repertoire of Southern Lapwing. Between December of 2017 and November of 2018, we carried out observations in an eight-hectares grassland site in northern Rio Grande do Sul. We used ad libitum and animal focusing techniques to identify and record the frequency and duration of specific behaviors. An ethogram was elaborated, representing the 23 detected behaviors, grouped in five categories: locomotion, maintenance, feeding, socio-agonistic, and reproduction. Our analysis showed that most behaviors vary in both frequency and duration over the year. We detected high frequency and duration of social-agonistic and reproductive behaviors during the breeding season, while other categories, like feeding and maintenance, showed a decrease in the same period, with greater commitment to protect the eggs and chicks. We also recorded three types of vocalization with different characteristics, one of which occurs exclusively during the breeding season. The results of our study allowed the identification and quantification of V. chilensis in southern Brazil, thus helping in understanding the relations between the species and its habitats in the region.

Resumo Apesar de muitos estudos sobre a ictiofauna do Arquipélago de Fernando de Noronha terem sido realizados, sua diversidade de peixes mesofóticos nunca foi estudada antes. Neste estudo utilizamos mergulho autônomo e mergulho técnico, vídeos subaquáticos remotos com isca e veículo operado remotamente para registrar peixes de ecossistemas rasos (≤ 30 m de profundidade) e mesofóticos (31 a 150 m de profundidade). Dezenove espécies de peixes pertencentes a 14 famílias são apresentadas aqui como novos registros, representando um aumento de 8,2% na riqueza de peixes marinhos da região, que agora possui um total de 250 espécies e 77 famílias. Esses novos registros incluem quatro prováveis novas espécies e reforçam a importância de estudos em ecossistemas mesofóticos. Nossos resultados também enfatizam a necessidade de proteção e atenção à essa ictiofauna única encontrada nesses ecossistemas profundos.

Abstract Although several studies on the ichthyofauna of the Fernando de Noronha Archipelago have been carried out, its mesophotic fish diversity has never been surveyed before. Here we used SCUBA and technical rebreather diving, baited remote underwater videos and remotely operated vehicle to record shallow (≤ 30 m depth) and mesophotic (31 to 150 m depth) fishes. Nineteen fish species belonging to 14 families are reported here as new records, representing an increase of 8.2% in marine fish richness for the region, which now has a total of 250 species and 77 families. These new records include four potential new species and highlight the importance of surveying mesophotic ecosystems, even in well studied sites. Our results also emphasize the need for protection and attention to the unique ichthyofauna found at mesophotic depths.

ABSTRACT (150 words) (same order that title) In sports, collective efficacy appears to be dependent on the interactions and organized dynamics between the players within the team. It is directly related to team's performance potential. This study examined the changes of perceived collective efficacy among young basketball players between 10 to 17 years across a 4-month competitive season, accounting for variation by age group. We explored the trends of perceived collective efficacy based on repeated measures across 4 months within the observed age range. Sixty-five adolescent male basketball players aged 13,7 (9,5 to 17,3) years at baseline were considered. Collective Efficacy Questionnaire for Sports (CEQS) was used to assess players' perception of collective efficacy. Players had high CEQS scores. Except for persistence, all CEQS factors did not vary by age group. No distinct trend of differences between age group was present. CEQS factors remained high on the second assessment, except for ability where there was a systematic decrease of the scores at end-season. A negative trend was apparent for persistence, preparation and unity as players were closer to late adolescence years. Overall, adolescent basketball players tend to have a positive perception of theirs and their teammates efficacy. Despite the small to trivial influence of exposure to training and competition during pubertal years observed, results suggest that approaching adult level may change negatively the efficacy perceptions of adolescent players. Hence, coaches and practitioners of youth basketball should consider that players' collective efficacy perceptions may vary as transient influences of pubertal growth and competitive level with age increase.

RESUMO A eficácia coletiva nos esportes parece depender das interações e dinâmicas organizadas entre os jogadores da equipe. Está diretamente relacionada ao seu potencial de desempenho. Examinamos as mudanças de eficácia coletiva percebida entre jovens jogadores de basquetebol (10 a 17 anos) ao longo de 4 meses de temporada competitiva, controlando a variação por faixa etária. Exploramos as tendências de eficácia coletiva percebida com base em medidas repetidas antes e depois de 4 meses. Sessenta e cinco adolescentes jogadores de basquetebol, com 13,7 (9,5 a 17,3) anos no início do estudo, foram considerados. O Collective Efficacy Questionnaire for Sports (CEQS) foi utilizado para avaliar a percepção sobre a eficácia coletiva. Os jogadores tiveram altas pontuações no CEQS. Exceto pela persistência, os fatores do CEQS não variaram por faixa etária. Não houveram diferenças entre as faixas etárias. Os fatores do CEQS permaneceram altos na segunda avaliação, exceto pela habilidade em que houve uma queda nos escores no final da temporada. Uma tendência negativa foi aparente para a persistência, preparação e união nos anos finais da adolescência. Em geral, os jogadores tenderam ter uma percepção positiva de sua eficácia e de seus colegas. Apesar da influência da exposição ao treinamento e competição ser pequena e não significativa durante a idade observada, os resultados sugerem que a aproximação do nível adulto pode alterar negativamente as percepções de eficácia dos jogadores. Devem-se considerar que as percepções de eficácia coletiva dos jogadores podem variar como influências transitórias do crescimento pubertário e do nível competitivo com o aumento da idade.

RESUMEN La eficacia colectiva en los deportes parece depender de las interacciones y dinámicas organizadas entre los jugadores del equipo. Está directamente relacionada con su potencial de rendimiento. Examinamos los cambios de eficacia colectiva percibidos entre jóvenes jugadores de baloncesto (10 a 17 años) por 4 meses de temporada competitiva, controlando la variación por grupo de edad. Exploramos las tendencias de eficacia colectiva percibida basados por medidas repetidas antes y después de 4 meses. Sesenta y cinco adolescentes jugadores de baloncesto, con 13,7 (9,5 a 17,3) años al inicio del estudio, fueron considerados. Se utilizó el Collective Efficacy Questionnaire for Sports (CEQS) para evaluar la percepción sobre la eficacia colectiva. Los jugadores tuvieron altas puntuaciones en el CEQS. Excepto por la persistencia, los factores del CEQS no variaron por grupo de edad. No hubo diferencias entre los grupos. Los factores del CEQS permanecieron altos en la segunda evaluación, excepto por la habilidad en que hubo una caída en los escores al final de la temporada. Una tendencia negativa fue aparente para la persistencia, preparación y unión en los años finales de la adolescencia. En general, los jugadores tienden a tener una percepción positiva de su eficacia y de sus colegas. A pesar de la influencia de la exposición al entrenamiento y la competición ser pequeña y no significativa durante la edad observada, los resultados sugieren que la aproximación del nivel adulto puede alterar negativamente las percepciones de eficacia de los jugadores. Se debe considerar que las percepciones de eficacia colectiva de los jugadores pueden variar como influencias transitorias del crecimiento pubertario y del nivel competitivo con el aumento de la edad.

ABSTRACT A neotype is designated for Pelecanus aquilus Linnaeus, 1758 (currently Fregata aquila ; Aves, Fregatidae) to fix the identity of this nominal species.

trans-Desidrocrotonina (t-DCTN), um bioditerpeno do tipo 19-nor-clerodano isolado de Croton cajucara Benth, representa um dos clerodanos da atualidade com maiores índices de investigações científicas. Neste trabalho, uma nova abordagem unindo dados de difração de raios X, dados de ressonância magnética nuclear (NMR) e dados teóricos foi aplicada para a completa caracterização da t-DCTN. Para tanto, a geometria de t-DCTN foi reavaliada por difração de raios X e NMR de ¹H e 13C e foi comparada com os dados teóricos obtidos por B3LYP/6-311G++(d,p). A subsequente avaliação dos valores teóricos e experimentais de deslocamentos químicos de NMR e constantes de acoplamento spin-spin apresentou correlações muito boas entre propriedades magnéticas teóricas e experimentais. Adicionalmente, os índices de deslocalização entre átomos de hidrogênio, d(H,H'), correlacionaram bem com os dados experimentais e calculados de constante de acoplamento. Uma análise topológica complementar utilizando a teoria quântica de átomos em moléculas (QTAIM) mostrou interações intramoleculares para t-DCTN.

trans-Dehydrocrotonin (t-DCTN) a bioactive 19-nor-diterpenoid clerodane type isolated from Croton cajucara Benth, is one of the most investigated clerodane in the current literature. In this work, a new approach joining X-ray diffraction data, nuclear magnetic resonance (NMR) data and theoretical calculations was applied to the thorough characterization of t-DCTN. For that, the geometry of t-DCTN was reevaluated by X-ray diffraction as well as ¹H and 13C NMR data, whose geometrical parameters where compared to those obtained from B3LYP/6-311G++(d,p) level of theory. From the evaluation of both calculated and experimental values of ¹H and 13C NMR chemical shifts and spin-spin coupling constants, it was found very good correlations between theoretical and experimental magnetic properties of t-DCTN. Additionally, the delocalization indexes between hydrogen atoms correlated accurately with theoretical and experimental spin-spin coupling constants. An additional topological analysis from quantum theory of atoms in molecules (QTAIM) showed intramolecular interactions for t-DCTN.

The type locality of the South American Tern, Sterna hirundinacea, has long been considered to be the state of Santa Catarina in South Brazil. This conclusion was probably based on two syntypes, from the Muséum national d'Histoire naturelle in Paris, France, one from Laguna and the other from an unspecified locality. The latter was probably shot on the coast of Rio de Janeiro. A recent molecular study has shown that Brazilian and Patagonian populations of S. hirundinacea are not completely panmictic, though genetic differentiation between them is low. No data from the Falkland Islands and Pacific coast populations have been available for comparison. If future analysis shows that Pacific and/or Falkland/Malvinas populations are genetically isolated from the Brazil-Patagonian ones, the name S. hirundinacea would apply only to birds from the latter populations. Given that the two syntypes were collected at two widely spaced localities, doubts exist as to the precise locality where one syntype was taken, and to clear up uncertainties, a lectotype of S. hirundinacea is herein designated.

We review existing data on the distribution of the Least Tern, Sternula antillarum along the Brazilian coast, based on the literature and museum specimens, and present results of a year-long study (October 2008 to September 2009) on the seasonal abundance of this species on a large tidal flat area, Cajuais Bank, in the State of Ceará, north-eastern Brazil. We evaluate whether the observed variation in the abundance of terns is due to the occurrence of an undocumented breeding colony, or alternatively, whether it results from an influx of migrants from the Northern Hemisphere. The recovery of historical data revealed that all literature references on the distribution of birds in the Americas, published up to the late 1990s include Brazil in the non-breeding range of the Least Tern. This inclusion is based on a few, old (late 19th and early 20th centuries) museum specimens, all of which have been collected on the northern and north-eastern coasts of this country'. From the late 1980s, birds continued to be occasionally recorded along the coastline, running from the State of Amapá (01°N) up to the State of Bahia (10°S), with records of single individuals in south-eastern and southern Brazil. An alleged record from Rocas Atoll, 260 km off the Brazilian mainland, might tentatively refer to the Old World Little Tern S. albifrons. At Cajuais Bank, Least Terns occurred from October 2008 to April 2009, and in September 2009. The highest numbers (> 800 individuals) were recorded in January-February (Southern Hemisphere's summer). The species was observed in rather small numbers (< 30) in March-April (early-mid Southern Hemisphere fall) and in September (early Southern Hemisphere spring), being absent from the area in May-August (Southern Hemisphere's fall and winter). In October-December 2008 (Southern Hemisphere's spring), and September 2009 (early Southern Hemisphere's summer), no birds were in breeding plumage. In January, about 32% of the birds were in breeding plumage, while from February-April (Southern Hemisphere's summer to mid fall) all were in breeding plumage. This pattern is consistent with what would be expected for migratory birds. The Cajuais Bank itself (and adjacent beaches and inland environments) holds the largest numbers of Least Terns recorded in Brazil, thus being one of the most significant sites along the migratory route of the species.