An endangered tree fern increases beta-diversity at a fine scale in the Atlantic Forest Ecosystem

R.N. and T.S.S. were funded by the Brazilian Government research support agency Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES). A.E.M. acknowledges the ERC (BioTIME 250189 and BioCHANGE 727440) and the Royal Society. A.R.K. is funded by the Brazilian Science Without Borders scheme/CAPES (109113-1), D.M.S.M. acknowledges the CNPq (Fellowship of Research productivity 307839/2014-1).Some species make substantial contribution to habitat heterogeneity, supporting species coexistence. Dicksonia sellowiana Hook., an endangered tree fern, is a known phorophyte for epiphytes, has the potential to be such a taxon. We tested the hypothesis that D. sellowiana increases plant diversity in Brazilian Restinga forest, a biodiversity hotspot, by augmenting the habitat heterogeneity at a fine scale. To do this we quantified α-diversity and β-diversity in three habitat types: on the tree fern trunks, immediately beneath the trunks and away from the trunks. In total, 40 ferns were sampled. Overall we recorded 2602 individuals belonging to 61 phanerophyte species in 30 families. The number of individuals sampled varied among habitats but rarefaction showed that richness did not differ. In contrast, species composition varied markedly amongst habitats. Both statistical approaches detected high levels of β-diversity, particularly between the species found in the vicinity of the fern, and those in the samples away from the trunks. Indicator species analysis was used to identify the species characteristic of the different habitats. About 30% of the species were exclusively found in “away plots”, 17% were exclusively “below plots” and 15% were found only on the trunks, 13% were found on the trunks and below them, 12% on “bellow” and “away plots”, 10% of species occurred in all areas and 3% were found on trunks and “away plots”. Our results lead us to conclude that the endangered fern D. sellowiana plays an important role in promoting habitat heterogeneity within the Restinga forest. As this iconic species is threatened, its overexploitation may lead to impoverishment of plant communities. Conservation effort towards both the area and this species are crucial to maintaining Restinga plant diversity.PostprintPeer reviewe

Abordagem diagnóstica a síncope: uma revisão bibliográfica: Diagnostic approach to syncope: a bibliographic review

A síncope trata-se de um evento frequente e responsável por promover seguidos desafios no ambiente profissional da saúde. Caracteriza-se por formatos que sofrem variações constantes, e os fatores causadores da síncope, em geral, não são capazes de serem representados detalhadamente, mesmo diante de análises clínicas minuciosas – além dos aspectos técnicos, na maioria dos casos, uma análise detalhada para averiguar os fatores causadores da síncope necessita de investimento financeiro elevado. Considerando-se os obstáculos técnicos e financeiros associados à abordagem diagnóstica, determinadas diretrizes científicas foram idealizadas a fim de apoiar, por meio de orientações técnicas, os especialistas na área da saúde referente ao diagnóstico e ao gerenciamento, especialmente, devido ao elevado número de invidíduos com quadro clínico associado à síncope. Ao considerar as principais diretrizes em nível internacional, a presente pesquisa destaca a Diretriz Norte Americana de 2017 e a Diretriz Europeia de 2018. De acordo com o contexto apresentado, essa pesquisa pretende analisar o seguinte problema de pesquisa: quais são as principais características em uma abordagem diagnóstica sincopal? Referente ao objetivo geral, busca-se aferir questões relevantes sobre o diagnóstico da síncope, especialmente, à luz das diretrizes norte americanas e das diretrizes europeias. Por sua vez, os objetivos específicos estão descritos a seguir: verificar aspectos conceituais sobre perda transitória de consciência (PTC) e síncope; investigar questões relevantes referente a abordagem diagnóstica sincopal; analisar características e discrepâncias sobre atendimento e diagnóstico da síncope entre a Diretriz Norte Americana de 2017 e a Diretriz Europeia de 2018. Neste estudo, foi adotado o procedimento metodológico associado à Revisão Bibliográfica Narrativa, também denominado como Revisão de Literatura, em que a pesquisa é qualitativa e de caráter exploratória

Doenças cardiovasculares associadas à Covid-19 – revisão de literatura/ Cardiovascular diseases associated with Covid-19 – a review of literature

Em dezembro de 2019, casos de pneumonia de etiologia desconhecida surgiram em Wuhan, China, com características clínicas muito semelhantes a um quadro de pneumonia viral. Apesar de o quadro clínico ser predominante de sintomas respiratórios, há evidências de que a COVID-19 pode causar complicações cardíacas, com elevação dos biomarcadores de estresse miocárdico, arritmias e insuficiência cardíaca, com risco aumentado de mortalidade. Estudos mostraram que 12 a 19,7% dos pacientes sem doença cardíaca prévia evoluíram com injúria miocárdica e suas complicações durante o período de internação. O provável mecanismo da lesão cardíaca envolve a formação de microtrombos na vasculatura do miocárdio, downregulation dos receptores da ECA-2, hiperativação da cascata inflamatória e imune, disfunção endotelial, hipoxemia, hiperativação simpática ou disautonomia e distúrbios hidroeletrolíticos. Lesão pulmonar grave no contexto de SARS-CoV-2 pode levar à fibrose pulmonar, hipertensão arterial pulmonar, doença cardiovascular e alterações metabólicas, sendo todos estes, fatores de risco para o desenvolvimento de insuficiência de ventrículo direito, tendo em vista aumento da pós carga direita. O entendimento sobre as complicações cardiológicas decorrentes da COVID-19 não está totalmente esclarecido, porém diversos estudos demonstram que tal associação é significativa

ATLANTIC EPIPHYTES: a data set of vascular and non-vascular epiphyte plants and lichens from the Atlantic Forest

Epiphytes are hyper-diverse and one of the frequently undervalued life forms in plant surveys and biodiversity inventories. Epiphytes of the Atlantic Forest, one of the most endangered ecosystems in the world, have high endemism and radiated recently in the Pliocene. We aimed to (1) compile an extensive Atlantic Forest data set on vascular, non-vascular plants (including hemiepiphytes), and lichen epiphyte species occurrence and abundance; (2) describe the epiphyte distribution in the Atlantic Forest, in order to indicate future sampling efforts. Our work presents the first epiphyte data set with information on abundance and occurrence of epiphyte phorophyte species. All data compiled here come from three main sources provided by the authors: published sources (comprising peer-reviewed articles, books, and theses), unpublished data, and herbarium data. We compiled a data set composed of 2,095 species, from 89,270 holo/hemiepiphyte records, in the Atlantic Forest of Brazil, Argentina, Paraguay, and Uruguay, recorded from 1824 to early 2018. Most of the records were from qualitative data (occurrence only, 88%), well distributed throughout the Atlantic Forest. For quantitative records, the most common sampling method was individual trees (71%), followed by plot sampling (19%), and transect sampling (10%). Angiosperms (81%) were the most frequently registered group, and Bromeliaceae and Orchidaceae were the families with the greatest number of records (27,272 and 21,945, respectively). Ferns and Lycophytes presented fewer records than Angiosperms, and Polypodiaceae were the most recorded family, and more concentrated in the Southern and Southeastern regions. Data on non-vascular plants and lichens were scarce, with a few disjunct records concentrated in the Northeastern region of the Atlantic Forest. For all non-vascular plant records, Lejeuneaceae, a family of liverworts, was the most recorded family. We hope that our effort to organize scattered epiphyte data help advance the knowledge of epiphyte ecology, as well as our understanding of macroecological and biogeographical patterns in the Atlantic Forest. No copyright restrictions are associated with the data set. Please cite this Ecology Data Paper if the data are used in publication and teaching events. © 2019 The Authors. Ecology © 2019 The Ecological Society of Americ

Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK.

BACKGROUND: A safe and efficacious vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), if deployed with high coverage, could contribute to the control of the COVID-19 pandemic. We evaluated the safety and efficacy of the ChAdOx1 nCoV-19 vaccine in a pooled interim analysis of four trials. METHODS: This analysis includes data from four ongoing blinded, randomised, controlled trials done across the UK, Brazil, and South Africa. Participants aged 18 years and older were randomly assigned (1:1) to ChAdOx1 nCoV-19 vaccine or control (meningococcal group A, C, W, and Y conjugate vaccine or saline). Participants in the ChAdOx1 nCoV-19 group received two doses containing 5 × 1010 viral particles (standard dose; SD/SD cohort); a subset in the UK trial received a half dose as their first dose (low dose) and a standard dose as their second dose (LD/SD cohort). The primary efficacy analysis included symptomatic COVID-19 in seronegative participants with a nucleic acid amplification test-positive swab more than 14 days after a second dose of vaccine. Participants were analysed according to treatment received, with data cutoff on Nov 4, 2020. Vaccine efficacy was calculated as 1 - relative risk derived from a robust Poisson regression model adjusted for age. Studies are registered at ISRCTN89951424 and ClinicalTrials.gov, NCT04324606, NCT04400838, and NCT04444674. FINDINGS: Between April 23 and Nov 4, 2020, 23 848 participants were enrolled and 11 636 participants (7548 in the UK, 4088 in Brazil) were included in the interim primary efficacy analysis. In participants who received two standard doses, vaccine efficacy was 62·1% (95% CI 41·0-75·7; 27 [0·6%] of 4440 in the ChAdOx1 nCoV-19 group vs71 [1·6%] of 4455 in the control group) and in participants who received a low dose followed by a standard dose, efficacy was 90·0% (67·4-97·0; three [0·2%] of 1367 vs 30 [2·2%] of 1374; pinteraction=0·010). Overall vaccine efficacy across both groups was 70·4% (95·8% CI 54·8-80·6; 30 [0·5%] of 5807 vs 101 [1·7%] of 5829). From 21 days after the first dose, there were ten cases hospitalised for COVID-19, all in the control arm; two were classified as severe COVID-19, including one death. There were 74 341 person-months of safety follow-up (median 3·4 months, IQR 1·3-4·8): 175 severe adverse events occurred in 168 participants, 84 events in the ChAdOx1 nCoV-19 group and 91 in the control group. Three events were classified as possibly related to a vaccine: one in the ChAdOx1 nCoV-19 group, one in the control group, and one in a participant who remains masked to group allocation. INTERPRETATION: ChAdOx1 nCoV-19 has an acceptable safety profile and has been found to be efficacious against symptomatic COVID-19 in this interim analysis of ongoing clinical trials. FUNDING: UK Research and Innovation, National Institutes for Health Research (NIHR), Coalition for Epidemic Preparedness Innovations, Bill & Melinda Gates Foundation, Lemann Foundation, Rede D'Or, Brava and Telles Foundation, NIHR Oxford Biomedical Research Centre, Thames Valley and South Midland's NIHR Clinical Research Network, and AstraZeneca

Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK

Background A safe and efficacious vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), if deployed with high coverage, could contribute to the control of the COVID-19 pandemic. We evaluated the safety and efficacy of the ChAdOx1 nCoV-19 vaccine in a pooled interim analysis of four trials. Methods This analysis includes data from four ongoing blinded, randomised, controlled trials done across the UK, Brazil, and South Africa. Participants aged 18 years and older were randomly assigned (1:1) to ChAdOx1 nCoV-19 vaccine or control (meningococcal group A, C, W, and Y conjugate vaccine or saline). Participants in the ChAdOx1 nCoV-19 group received two doses containing 5 × 1010 viral particles (standard dose; SD/SD cohort); a subset in the UK trial received a half dose as their first dose (low dose) and a standard dose as their second dose (LD/SD cohort). The primary efficacy analysis included symptomatic COVID-19 in seronegative participants with a nucleic acid amplification test-positive swab more than 14 days after a second dose of vaccine. Participants were analysed according to treatment received, with data cutoff on Nov 4, 2020. Vaccine efficacy was calculated as 1 - relative risk derived from a robust Poisson regression model adjusted for age. Studies are registered at ISRCTN89951424 and ClinicalTrials.gov, NCT04324606, NCT04400838, and NCT04444674. Findings Between April 23 and Nov 4, 2020, 23 848 participants were enrolled and 11 636 participants (7548 in the UK, 4088 in Brazil) were included in the interim primary efficacy analysis. In participants who received two standard doses, vaccine efficacy was 62·1% (95% CI 41·0–75·7; 27 [0·6%] of 4440 in the ChAdOx1 nCoV-19 group vs71 [1·6%] of 4455 in the control group) and in participants who received a low dose followed by a standard dose, efficacy was 90·0% (67·4–97·0; three [0·2%] of 1367 vs 30 [2·2%] of 1374; pinteraction=0·010). Overall vaccine efficacy across both groups was 70·4% (95·8% CI 54·8–80·6; 30 [0·5%] of 5807 vs 101 [1·7%] of 5829). From 21 days after the first dose, there were ten cases hospitalised for COVID-19, all in the control arm; two were classified as severe COVID-19, including one death. There were 74 341 person-months of safety follow-up (median 3·4 months, IQR 1·3–4·8): 175 severe adverse events occurred in 168 participants, 84 events in the ChAdOx1 nCoV-19 group and 91 in the control group. Three events were classified as possibly related to a vaccine: one in the ChAdOx1 nCoV-19 group, one in the control group, and one in a participant who remains masked to group allocation. Interpretation ChAdOx1 nCoV-19 has an acceptable safety profile and has been found to be efficacious against symptomatic COVID-19 in this interim analysis of ongoing clinical trials

Estudo de populações de Schizolobium parahyba (Vell.) S.F. Blake (Leguminosae: Caesalpinoidae) para avaliação do seu potencial invasor

Schizolobium parahyba (Vell.) S.F. Blake is a pioneer heliophyte species, with irregular and discontinuous dispersion. It is native and exclusive of Atlantic Rainforest, however, due to its high growth rate and to the shape of its crown, S. parahyba is recommended for forest restoration in areas of Tropical Semideciduous Forest. Currently, it has been questioned the use of this species in forest restoration. Considering that tree species that have 1) phenotypic plasticity and / or tolerance and 2) formation of persistent seed bank, are capable to keep stable populations in different environments, the hypothesis of this research is that S. parahyba can become invasive in Semideciduous Forest fragments. To test this hypothesis, we analyzed the morphology and growth form of the species in the Atlantic Rainforest and Semideciduous Forest, as well as ontogenetic and spatial structures present in both physiognomies. This dissertation is divided into four chapters. Firstly, I contextualize and justify this research. Then, I make a brief description of physiognomies studied, as well as a characterization of sampling sites. In Chapter 3, I compare the allometric relationships and architectural models for the different populations. Finally, in Chapter 4, I compare the ontogenetic and spatial structures for the species between different sampling sites in order to detect whether the species is able to establish stable populations in Semideciduous Forest. After evaluation of morphological characters, populations were divided into four ontogenetic stages: a) seedling, b) juvenile c) subadult, and d) adult. The evaluation of the architectural model of S. parahyba showed no difference in the morphology of the crown of individuals between biomes. The allometry analysis showed that there were differences between the growth patterns of S. parahyba between biomes for seedlings and for the pooled data; however, allometric relationships had no difference between adults. The total individuals abundance in Semideciduous Forest was lower than in the Rainforest. We found no single pattern of ontogenetic structure for the studied populations. There were found individuals of intermediate ontogenetic stages in Semideciduous Forest fragments. In all populations, S. parahyba was distributed in aggregates; however, it was also found scattered individuals within the fragment. The results indicate that S. parahyba shows tolerance and plasticity in response to environmental differences, which are important characteristics when assessing the status of an alien species. Finally, from the results obtained, it can be assumed that S. parahyba may become invasive in fragments of Semideciduous Forest.Universidade Federal de Sao CarlosO guapuruvu, Schizolobium parahyba (Vell.) S.F. Blake e uma especie heliofila, pioneira, com dispersao irregular e descontinua. E caracteristica e exclusiva da Floresta Ombrofila Densa Atlantica, contudo, devido a sua alta taxa de crescimento em altura e ao formato de sua copa, S. parahyba passou a ser recomendado em plantios de restauracao florestal em areas sob o dominio da Floresta Estacional Semidecidua. Atualmente, tem sido questionado o uso desta especie em plantios de restauracao e recomposicao de sistemas florestais. Considerando que especies arboreas que apresentem 1) plasticidade fenotipica e/ou tolerancia e 2) formacao de banco de sementes persistente, sejam capazes de formar populacoes estaveis em ambientes distintos, a hipotese do presente trabalho e a de que S. parahyba pode se tornar invasora em fragmentos de Floresta Estacional Semidecidua. Para testar esta hipotese, analisamos a morfologia e a forma de crescimento da especie na Floresta Ombrofila Densa e na Floresta Estacional, bem como as estruturas ontogeneticas e espaciais presentes em ambos os dominios fitogeograficos. Esta dissertacao esta dividida em 4 capitulos. Na Contextualizacao , e feita uma breve justificativa desta pesquisa. Na Caracterizacao das areas , e feita uma descricao sucinta dos dominios fitogeograficos estudados, bem como uma caracterizacao dos sitios de amostragem. No Capitulo 1, sao comparadas as relacoes alometricas e os modelos arquiteturais observados para as diferentes populacoes, com vistas a sua plasticidade e tolerancia. Finalmente, no Capitulo 2, sao comparadas as estruturas ontogeneticas e espaciais para a especie entre os diferentes sitios de amostragem, visando detectar se a especie e capaz de estabelecer populacoes estaveis na Floresta Estacional Semidecidua. Apos avaliacao de caracteres morfologicos, as populacoes foram divididas em quatro estadios ontogeneticos: a) plantula; b) juvenil; c) subadulto; e d) adulto. A avaliacao do modelo arquitetural de S. parahyba mostrou nao haver diferenca na morfologia da copa dos individuos entre os dominios fitogeograficos. As analises de alometria mostraram que houve diferenca entre os padroes de crescimento de S. parahyba entre os dominios fitogeograficos para plantulas e para os dados totais; entretanto, as relacoes alometricas nao foram diferentes para os adultos. A abundancia total de individuos na Floresta Estacional foi menor que na Floresta Ombrofila. Nao foi encontrado um padrao unico de estrutura ontogenetica para as populacoes estudadas. Foram encontrados individuos de estadios ontogeneticos intermediarios nos fragmentos de Floresta Estacional Semidecidua. Em todas as populacoes, S. parahyba distribuiu-se de forma agregada nos sitios de amostragem, havendo, entretanto, individuos dispersos no interior do fragmento, nao contidos nos adensamentos. Os resultados indicam que S. parahyba apresenta tanto plasticidade como de tolerancia como resposta as diferencas ambientais, sendo estas caracteristicas importantes quando se avalia o status de uma especie exotica. Finalmente, a partir dos resultados obtidos, pode-se considerar que S. parahyba e uma especie que tem risco de se tornar invasora em fragmentos de Floresta Estacional

Exploração de Euterpe edulis Mart. (Arecaceae): efeitos sobre a estrutura de comunidades vegetais

The harvesting of non-timber forest products (NTFPs) has been considered as a low-impact activity. However, the increasing demand of these products made greater the exploitation, which may cause depletion of resources in Nature. Euterpe edulis Mart. (Arecaceae) is one of the most studied plant species in Brazil, because it is economically important, listed among the most relevant products provided by Atlantic Rainforest. Moreover, this species is considered ecologically important, because it is a valuable food resource for fauna. In natural conditions, E. edulis is the most abundant species in Atlantic Rainforest. Nevertheless, illegal and massive harvesting lead the species to local extinction in some remnants, which resulted in the inclusion of the palm tree amongst the endangered plant species in Brazil. In this context, this study aimed to evaluate the impact of palm tree harvest on diversity at seed rain, regeneration layer and their relationship with the adult plant community. Thus, this study was carried out in two areas at Ilha do Cardoso State Park, both of them with the same land use history, despite the occurrence of massive palm heart harvest within one of them until 20 years ago. At these areas, we sampled seed rain with and without pulp, the regeneration layer and the adult plant community. The major motivations for this study were to apply diversity analysis on the assessment of harvesting impact, and to provide scientific information to the establishment of viable guidelines to the sustainable harvest of palm tree products. Our results showed that the abundance of E. edulis is related to the change of diversity patterns and species composition in seed rain and regeneration layer, and may have an influence on species composition in the future. This confirms the general hypothesis of this study, i.e. the disturbance caused by palm heart harvesting causes changes on species abundance enough to modify plant community structure. These changes could be detected even it has been 20 years after the end of illegal harvesting within the harvested area. The results also indicate that it is viable to make the sustainable harvest of E. edulis products, considering a selective removal of adult individuals and avoiding total suppression of clumps of palm tree. These actions promote heterogeneity on species composition of seed rain and regeneration layer.Universidade Federal de Sao CarlosPelas caracteristicas de seu uso e exploracao, a extracao de produtos florestais nao madeireiros (PFNMs) e tida como sendo de baixo impacto ecologico. Entretanto, a crescente utilizacao destas materias primas nos mercados consumidores levou a um aumento da demanda de exploracao, o que pode levar a deplecao dos produtos explorados. Euterpe edulis (Arecaceae) e uma das especies vegetais mais estudadas do pais, pois tem uma alta importancia economica, sendo um dos principais PFNMs obtidos da Mata Atlantica. Alem disso, a especie tem grande importancia ecologica, por ser um recurso alimentar valioso para a fauna. Em condicoes naturais, E. edulis e a especie dominante na comunidade adulta nas areas cobertas por Floresta Atlantica. Entretanto, a exploracao ilegal e massiva levou a especie a extincao local em certos remanescentes de Mata Atlantica, culminando em sua inclusao entre as especies ameacadas no pais. Diante deste contexto, o presente estudo teve como objetivo geral avaliar o impacto da exploracao do palmito de E. edulis sobre a diversidade na chuva de sementes, no estrato regenerante e a sua relacao com a comunidade adulta. Deste modo, o estudo foi realizado em duas areas no Parque Estadual Ilha do Cardoso, ambas com historico de uso similar, porem, uma delas sofreu exploracao massiva de palmito de E. edulis ate ha cerca de 20 anos, enquanto que a outra nao foi alvo deste tipo de uso. Nestas areas, amostramos a chuva de sementes com e sem polpa, o estrato regenerante e a comunidade adulta. As principais motivacoes deste estudo foram aplicar analises de diversidade na avaliacao e fornecer subsidio cientifico para o estabelecimento de diretrizes mais especificas e viaveis para o uso sustentavel deste produto, que e economicamente importante, mas que tambem e considerada uma especie chave na Floresta Atlantica. Os resultados mostraram que a abundancia de E. edulis altera padroes de diversidade e composicao em especies na chuva de sementes e no estrato regenerante, podendo influenciar na composicao das comunidades vegetais no futuro, confirmando a hipotese geral desta tese, de que o disturbio causado pela exploracao de E. edulis produz alteracoes na densidade de individuos da palmeira suficiente para modificar a estrutura das comunidades vegetais. Tais mudancas puderam ser detectadas mesmo apos 20 anos sem a atividade de exploradores ilegais na area estudada. Os resultados indicam, tambem, que o uso sustentavel do palmito de E. edulis pode ser viavel, considerando a remocao seletiva de individuos adultos, evitando a total supressao de adensamentos desta palmeira, promovendo a heterogeneidade da composicao da chuva de sementes e do estrato regenerante

An endangered tree fern increases beta-diversity at a fine scale in the Atlantic Forest Ecosystem

Some species make substantial contribution to habitat heterogeneity, supporting species coexistence. Dicksonia sellowiana Hook., an endangered tree fern, is a known phorophyte for epiphytes, has the potential to be such a taxon. We tested the hypothesis that D. sellowiana increases plant diversity in Brazilian Restinga forest, a biodiversity hotspot, by augmenting the habitat heterogeneity at a fine scale. To do this we quantified α-diversity and β-diversity in three habitat types: on the tree fern trunks, immediately beneath the trunks and away from the trunks. In total, 40 ferns were sampled. Overall we recorded 2602 individuals belonging to 61 phanerophyte species in 30 families. The number of individuals sampled varied among habitats but rarefaction showed that richness did not differ. In contrast, species composition varied markedly amongst habitats. Both statistical approaches detected high levels of β-diversity, particularly between the species found in the vicinity of the fern, and those in the samples away from the trunks. Indicator species analysis was used to identify the species characteristic of the different habitats. About 30% of the species were exclusively found in “away plots”, 17% were exclusively “below plots” and 15% were found only on the trunks, 13% were found on the trunks and below them, 12% on “bellow” and “away plots”, 10% of species occurred in all areas and 3% were found on trunks and “away plots”. Our results lead us to conclude that the endangered fern D. sellowiana plays an important role in promoting habitat heterogeneity within the Restinga forest. As this iconic species is threatened, its overexploitation may lead to impoverishment of plant communities. Conservation effort towards both the area and this species are crucial to maintaining Restinga plant diversity

Efeito da adição de aminoácidos essenciais à dieta sobre a secreção de enzimas digestivas de jundiá Rhamdia quelen (Siluriformes, Pimelodidae) = Effect of dietary essential amino acids addition on digestive enzime secretion in silver catfish Rhamdia quelen (Siluriformes, Pimelodidae)

Em estudos realizados com variação no teor de proteína na ração para peixes, foi demonstrado o aumento das atividades de protease alcalina, protease ácida, tripsina e quimiotripsina do trato digestório de jundiá (Rhamdia quelen). Esses fatos sugerem que produtos liberados pela digestão na luz desse trato podem influenciar a síntese e a secreção de enzimas digestivas. A secreção destas enzimas pelo pâncreas, em vertebrados, responde à influência neurale humoral. No presente trabalho, foram testadas quatro concentrações (0, 3, 6 e 12%) de uma mistura de aminoácidos (treonina, fenilalanina, leucina, valina, arginina e triptofano em iguaisproporções) em dietas isocalóricas contendo 3.500 kcal de energia digestível kg-1 de ração, e dietas isoproteicas contendo 20% de proteína, em juvenis de jundiá. Foram utilizados dez animais portratamento, sendo os peixes estocados num sistema fechado com recirculação de água e temperatura controlada. Os peixes submetidos a estes tratamentos apresentaram atividade da protease alcalina na região anterior do intestino, responsiva aos diferentes níveis aminoácidos da alimentação. Todavia, as atividades protease alcalina do fígado e amilase do fígado e intestino anterior não foram detectadas. Estes resultados sugerem que a atividade protease alcalina do intestino anterior seja induzida por aminoácidos liberados na luz do trato digestório. <br><br>Studies carried out with variation of protein concentration in the fish feed have shown an increase in the activity of alkaline proteases, acid proteases, trypsin and chimotrypsin from the digestive tract of silver catfish (Rhamdia quelen). These facts suggest that products released by digestion in the lumen of this tract can influenced the synthesis and secretion of digestive enzymes. The secretion of these enzymes by the pancreas in vertebrate responses to neural and humoral influences. In the present study, four concentration (0, 3, 6 and 12%) of an amino acid mix(threonine, phenylalanine, leucine, valine, arginine and thryptophan, in equal amounts) were tested in isocaloric (3500 kcal of digestible energy kg-1 of feed) and isoproteic (20% of protein) diets on juveniles of silver catfish. It was used 10 specimens per treatment stocked in a water recirculation system, with controlled and constant temperature. The fish submitted to the treatments presented alkaline activity in the anterior region of the gut, responding to thedifferent levels of amino acid in the feed. Although there was alkaline proteases activity in the liver, the amylase activity of the liver and anterior gut was not observed