Herbivory and leaf expansion of Cyathea phalerata Mart (Cyatheaceae) in subtropical Atlantic Forest, southern Brazil / Herbivoria e expansão foliar de Cyathea phalerata Mart. (Cyatheaceae) em Floresta Atlântica subtropical no sul do Brasil

Herbivory is an interaction with great impact on plant communities since relationships between herbivores and plants are fundamental to the distribution and abundance of species over time and space. The aim of this study was to monitor the rate of leaf expansion in the tree fern Cyathea phalerata and evaluate the damage caused by herbivores to leaves of different ages and whether such damage is related to temperature and precipitation. The study was performed in a subtropical Atlantic Forest fragment located in the municipality of Caraá, in the northeast hillside of Rio Grande do Sul state, in southern Brazil. We monitored 24 mature individuals of C. phalerata with croziers in a population of approximately 50 plants. Leaf expansion rate, percentage of damaged leaves and leaf blade consumption rate by herbivory were calculated. Monthly means for temperature and accumulated rainfall were calculated from daily data. Croziers of C. phalerata were found to expand rapidly during the first and second months after emergence (3.98 cm day-¹; 2.91 cm day-¹, respectively). Damage caused by herbivory was observed in all of the monitored leaves, but none of the plants experienced complete defoliation. The highest percentage (57%) of damaged leaves was recorded at 60 days of monitoring, and also the highest monthly consumption rate of the blade (6.04%) occurred with young, newly-expanded leaves, while this rate remained between 1.50 and 2.21% for mature leaves. Rates of monthly leaf consumption and damaged leaves showed positive and strong relationship with each other and with temperature. The rapid leaf expansion observed for C. phalerata can be considered a phenological strategy to reduce damage to young leaves by shortening the developmental period and accelerating the increase of defenses in mature leaves.

A herbivoria é uma interação de grande impacto sobre as comunidades de plantas, uma vez que as relações entre herbívoros e plantas são fundamentais para a distribuição e abundância das espécies ao longo do tempo e do espaço. O objetivo deste estudo foi monitorar a taxa de expansão foliar da samambaia arborescente Cyathea phalerata e avaliar o dano causado por herbívoros a folhas de diferentes idades, assim como verificar se este dano está relacionado à temperatura e à precipitação. O estudo foi realizado em um fragmento de Floresta Atlântica subtropical localizado no município de Caraá, na encosta nordeste do estado do Rio Grande do Sul, no sul do Brasil. Nós monitoramos 24 indivíduos maduros de C. phalerata com báculos em uma população de aproximadamente 50 plantas. A taxa de expansão foliar, a porcentagem de folhas danificadas e a taxa de consumo da lâmina foliar por herbivoria foram calculados. Médias mensais de temperatura e precipitação acumulada foram calculadas a partir de dados diários. Báculos de C. phalerata expandiram rapidamente durante o primeiro e o segundo mês após emergência (3,98 cm dia-¹; 2,91 cm dia-¹, respectivamente). O dano causado por herbivoria foi observado em todas as folhas monitoradas, mas nenhuma das plantas sofreu desfolhação completa. A maior porcentagem (57%) de folhas danificadas foi registrada aos 60 dias de monitoramento, e também a maior taxa de consumo mensal (6,04%) ocorreu em folhas jovens, recém expandidas, enquanto esta taxa permaneceu entre 1,50 e 2,21% em folhas maduras. As taxas mensais de consumo da lâmina foliar e de folhas danificadas mostraram relação positiva e forte entre si e com a temperatura. A rápida expansão foliar observada em C. phalerata pode ser considerada uma estratégia fenológica para reduzir o dano a folhas jovens, abreviando o período de desenvolvimento e acelerando o aumento das defesas em folhas maduras.

Herbivory and leaf expansion of Cyathea phalerata Mart. (Cyatheaceae) in subtropical Atlantic Forest, southern Brazil

Abstract Herbivory is an interaction with great impact on plant communities since relationships between herbivores and plants are fundamental to the distribution and abundance of species over time and space. The aim of this study was to monitor the rate of leaf expansion in the tree fern Cyathea phalerata and evaluate the damage caused by herbivores to leaves of different ages and whether such damage is related to temperature and precipitation. The study was performed in a subtropical Atlantic Forest fragment located in the municipality of Caraá, in the northeast hillside of Rio Grande do Sul state, in southern Brazil. We monitored 24 mature individuals of C. phalerata with croziers in a population of approximately 50 plants. Leaf expansion rate, percentage of damaged leaves and leaf blade consumption rate by herbivory were calculated. Monthly means for temperature and accumulated rainfall were calculated from daily data. Croziers of C. phalerata were found to expand rapidly during the first and second months after emergence (3.98 cm day-1; 2.91 cm day-1, respectively). Damage caused by herbivory was observed in all of the monitored leaves, but none of the plants experienced complete defoliation. The highest percentage (57%) of damaged leaves was recorded at 60 days of monitoring, and also the highest monthly consumption rate of the blade (6.04%) occurred with young, newly-expanded leaves, while this rate remained between 1.50 and 2.21% for mature leaves. Rates of monthly leaf consumption and damaged leaves showed positive and strong relationship with each other and with temperature. The rapid leaf expansion observed for C. phalerata can be considered a phenological strategy to reduce damage to young leaves by shortening the developmental period and accelerating the increase of defenses in mature leaves.

Resumo A herbivoria é uma interação de grande impacto sobre as comunidades de plantas, uma vez que as relações entre herbívoros e plantas são fundamentais para a distribuição e abundância das espécies ao longo do tempo e do espaço. O objetivo deste estudo foi monitorar a taxa de expansão foliar da samambaia arborescente Cyathea phalerata e avaliar o dano causado por herbívoros a folhas de diferentes idades, assim como verificar se este dano está relacionado à temperatura e à precipitação. O estudo foi realizado em um fragmento de Floresta Atlântica subtropical localizado no município de Caraá, na encosta nordeste do estado do Rio Grande do Sul, no sul do Brasil. Nós monitoramos 24 indivíduos maduros de C. phalerata com báculos em uma população de aproximadamente 50 plantas. A taxa de expansão foliar, a porcentagem de folhas danificadas e a taxa de consumo da lâmina foliar por herbivoria foram calculados. Médias mensais de temperatura e precipitação acumulada foram calculadas a partir de dados diários. Báculos de C. phalerata expandiram rapidamente durante o primeiro e o segundo mês após emergência (3,98 cm dia-1; 2,91 cm dia-1, respectivamente). O dano causado por herbivoria foi observado em todas as folhas monitoradas, mas nenhuma das plantas sofreu desfolhação completa. A maior porcentagem (57%) de folhas danificadas foi registrada aos 60 dias de monitoramento, e também a maior taxa de consumo mensal (6,04%) ocorreu em folhas jovens, recém expandidas, enquanto esta taxa permaneceu entre 1,50 e 2,21% em folhas maduras. As taxas mensais de consumo da lâmina foliar e de folhas danificadas mostraram relação positiva e forte entre si e com a temperatura. A rápida expansão foliar observada em C. phalerata pode ser considerada uma estratégia fenológica para reduzir o dano a folhas jovens, abreviando o período de desenvolvimento e acelerando o aumento das defesas em folhas maduras.

Herbivory and leaf expansion of Cyathea phalerata Mart. (Cyatheaceae) in subtropical Atlantic Forest, southern Brazil / Herbivoria e expansão foliar de Cyathea phalerata Mart. (Cyatheaceae) em Floresta Atlântica subtropical no sul do Brasil

Abstract Herbivory is an interaction with great impact on plant communities since relationships between herbivores and plants are fundamental to the distribution and abundance of species over time and space. The aim of this study was to monitor the rate of leaf expansion in the tree fern Cyathea phalerata and evaluate the damage caused by herbivores to leaves of different ages and whether such damage is related to temperature and precipitation. The study was performed in a subtropical Atlantic Forest fragment located in the municipality of Caraá, in the northeast hillside of Rio Grande do Sul state, in southern Brazil. We monitored 24 mature individuals of C. phalerata with croziers in a population of approximately 50 plants. Leaf expansion rate, percentage of damaged leaves and leaf blade consumption rate by herbivory were calculated. Monthly means for temperature and accumulated rainfall were calculated from daily data. Croziers of C. phalerata were found to expand rapidly during the first and second months after emergence (3.98 cm day-1; 2.91 cm day-1, respectively). Damage caused by herbivory was observed in all of the monitored leaves, but none of the plants experienced complete defoliation. The highest percentage (57%) of damaged leaves was recorded at 60 days of monitoring, and also the highest monthly consumption rate of the blade (6.04%) occurred with young, newly-expanded leaves, while this rate remained between 1.50 and 2.21% for mature leaves. Rates of monthly leaf consumption and damaged leaves showed positive and strong relationship with each other and with temperature. The rapid leaf expansion observed for C. phalerata can be considered a phenological strategy to reduce damage to young leaves by shortening the developmental period and accelerating the increase of defenses in mature leaves.

Resumo A herbivoria é uma interação de grande impacto sobre as comunidades de plantas, uma vez que as relações entre herbívoros e plantas são fundamentais para a distribuição e abundância das espécies ao longo do tempo e do espaço. O objetivo deste estudo foi monitorar a taxa de expansão foliar da samambaia arborescente Cyathea phalerata e avaliar o dano causado por herbívoros a folhas de diferentes idades, assim como verificar se este dano está relacionado à temperatura e à precipitação. O estudo foi realizado em um fragmento de Floresta Atlântica subtropical localizado no município de Caraá, na encosta nordeste do estado do Rio Grande do Sul, no sul do Brasil. Nós monitoramos 24 indivíduos maduros de C. phalerata com báculos em uma população de aproximadamente 50 plantas. A taxa de expansão foliar, a porcentagem de folhas danificadas e a taxa de consumo da lâmina foliar por herbivoria foram calculados. Médias mensais de temperatura e precipitação acumulada foram calculadas a partir de dados diários. Báculos de C. phalerata expandiram rapidamente durante o primeiro e o segundo mês após emergência (3,98 cm dia-1; 2,91 cm dia-1, respectivamente). O dano causado por herbivoria foi observado em todas as folhas monitoradas, mas nenhuma das plantas sofreu desfolhação completa. A maior porcentagem (57%) de folhas danificadas foi registrada aos 60 dias de monitoramento, e também a maior taxa de consumo mensal (6,04%) ocorreu em folhas jovens, recém expandidas, enquanto esta taxa permaneceu entre 1,50 e 2,21% em folhas maduras. As taxas mensais de consumo da lâmina foliar e de folhas danificadas mostraram relação positiva e forte entre si e com a temperatura. A rápida expansão foliar observada em C. phalerata pode ser considerada uma estratégia fenológica para reduzir o dano a folhas jovens, abreviando o período de desenvolvimento e acelerando o aumento das defesas em folhas maduras.

Calcium homeostasis behavior and cardiac function on left ventricular remodeling by pressure overload

Sarcoplasmic reticulum Ca2+-ATPase (SERCA2a) and sarcolemmal Na+/Ca2+ exchanger (NCX1) structures are involved in heart cell Ca2+ homeostasis. Previous studies have shown discrepancies in their function and expression in heart failure. The goal of this study was to evaluate heart function and hypertrophied muscle Ca2+-handling protein behavior under pressure overload. Twenty male Wistar rats were divided into two groups: Aortic stenosis (AoS), induced by a clip placed at the beginning of the aorta, and Control (Sham). After 18 weeks, heart function and structure were evaluated by echocardiogram. Myocardial function was analyzed by isolated papillary muscle (IPM) at basal condition and Ca2+ protein functions were evaluated after post-pause contraction and blockage with cyclopiazonic acid in IPM. Ca2+-handling protein expression was studied by western blot (WB). Echocardiogram showed that AoS caused concentric hypertrophy with enhanced ejection fraction and diastolic dysfunction inferred by dilated left atrium and increased relative wall thickness. IPM study showed developed tension was the same in both groups. AoS showed increased stiffness revealed by enhanced resting tension, and changes in Ca2+ homeostasis shown by calcium elevation and SERCA2a blockage maneuvers. WB revealed decreased NCX1, SERCA2a, and phosphorylated phospholambam (PLB) on serine-16 in AoS. AoS had left ventricular hypertrophy and diastolic dysfunction compared to Sham; this could be related to our findings regarding calcium homeostasis behavior: deficit in NCX1, SERCA2a, and phosphorylated PLB on serine-16.

Isolated obesity resistance condition or associated with aerobic exercise training does not promote cardiac impairment

Mechanisms involved in cardiac function and calcium (Ca2+) handling in obese-resistant (OR) rats are still poorly determined. We tested the hypothesis that unsaturated high-fat diet (HFD) promotes myocardial dysfunction in OR rats, which it is related to Ca2+ handling. In addition, we questioned whether exercise training (ET) becomes a therapeutic strategy. Male Wistar rats (n=80) were randomized to standard or HFD diets for 20 weeks. The rats were redistributed for the absence or presence of ET and OR: control (C; n=12), control + ET (CET; n=14), obese-resistant (OR; n=9), and obese-resistant + ET (ORET; n=10). Trained rats were subjected to aerobic training protocol with progressive intensity (55-70% of the maximum running speed) and duration (15 to 60 min/day) for 12 weeks. Nutritional, metabolic, and cardiovascular parameters were determined. Cardiac function and Ca2+ handling tests were performed in isolated left ventricle (LV) papillary muscle. OR rats showed cardiac atrophy with reduced collagen levels, but there was myocardial dysfunction. ET was efficient in improving most parameters of body composition. However, the mechanical properties and Ca2+ handling from isolated papillary muscle were similar among groups. Aerobic ET does not promote morphological and cardiac functional adaptation under the condition of OR.

Heterogeneity of fern communities in riparian forest remnants from the South Brazilian Campos (Pampa) / Heterogeneidade de comunidades de samambaias em remanescentes de mata ciliar nos campos (Pampa) sul do Brasil

Abstract Riparian forests present biotic and abiotic factors that influence environmental dissimilarity, which reflect specific fern distribution. The purpose of this this study was to evaluate the environmental heterogeneity associated to the terrestrial fern communities in riparian forest remnants in the grasslands southern half of Rio Grande do Sul state . We sampled ten 5×5 m plots in each site (AI, AII and AIII), totaling 30 plots. In each plot, fern species were inventoried and vegetative, microclimatic and edaphic parameters were collected. A total of 24 species were surveyed in the three riparian forest remnants, distributed in 19 genera and 10 families. The Principal Components Analysis (PCA) showed that plots of AI had the highest temperature and aluminum values, while humidity was the lowest, which was reflected in the decrease of ferns richness. Soil moisture and air humidity were variables more related to the plots of AII and AII, indicating that these plants were favored in these environments. The floristic identity characteristic of each site suggests that many species are dependent to certain local environmental conditions. In this sense, even in very geographically close sites, riparian remnants deserve conservation attention, since they are capable of harboring high diversity in this grassland phytophysiognomy in southern Brazil. The results of this integrated study, with vegetation, climatic, and edaphic parameters, suggest, as expected, that ferns categorically respond to the heterogeneity shown by riparian environments, even when fragments are geographically very close to each other.

Resumo As florestas ripárias apresentam fatores bióticos e abióticos que influenciam a dissimilaridade ambiental, e que refletem a distribuição específica de samambaias. O objetivo deste trabalho foi avaliar a heterogeneidade ambiental associada às comunidades de samambaias terrícolas em remanescentes de mata ciliar dos campos da metade sul do estado do Rio Grande do Sul (Pampa). Foram amostradas dez parcelas de 5×5 m em cada sítio (AI, AII e AIII), totalizando 30 parcelas. Em cada quadro, foram inventariadas as espécies de samambaia, além de outros parâmetros vegetacionais, microclimáticos e edáficos. Um total de 24 espécies foram identificadas nos três remanescentes de mata ciliar, distribuídas em 19 gêneros e 10 famílias. A Análise de Componentes Principais (PCA) mostrou que as parcelas de AI apresentaram os maiores valores de temperatura e alumínio, enquanto a umidade foi a menor, o que se refletiu na diminuição da riqueza de samambaias. A umidade do solo e a umidade do ar foram as variáveis ​​mais relacionadas às parcelas de AII e AIII, indicando que essas plantas foram favorecidas nesses. A identidade florística característica de cada local sugere que muitas espécies são dependentes de certas condições ambientais locais. Nesse sentido, mesmo em sítios geograficamente próximos, remanescentes de matas ciliares merecem atenção no que se refere a conservação, uma vez que são capazes de abrigar grande diversidade nesta fitofisionomia exclusiva do sul do Brasil. Os resultados deste estudo integrado, com parâmetros vegetacionais, climáticos e edáficos, sugerem, que as samambaias respondem categoricamente à heterogeneidade mostrada pelos ambientes ripários, mesmo quando os fragmentos estão próximos.

Phytosociological contrast of ferns and lycophytes from forest fragments with different surroundings matrices in southern Brazil / Contraste fitossociológico de samambaias e licófitas de fragmentos florestais com diferentes matrizes de entorno no sul do Brasil

Abstract Forest edges typically exhibit higher luminosity and lower humidity than the forest interior, resulting in an abiotic gradient. However, the degree of abiotic difference can be affected from the type of the matrix, influencing the selection of species. We compared the floristic and phytosociological structure of understory communities of ferns and lycophytes of the edge and interior of three forest sites influenced by different types of surrounding matrices (natural field, Pinus plantation, and cultivation of crops). In the region of Araucaria Forest, in Rio Grande do Sul, Brazil, twelve 10 × 10 m plots were selected at the edge and interior of each site, totaling 72 plots and to evaluate the phytosociological contrast, using as a parameter coverage and species richness per plot to evaluate this contrast. We recorded a total of 38 species in the studied areas, distributed in 15 families. The results show that the edge effect acts at different intensities in the analyzed sites. In the site with unnatural matrix, the composition was more homogeneous both in the edges and in the interiors and presented lower richness, showing a more pronounced and deep impact. Already in the site with natural matrix surroundings, although the border also presents low richness, the interior was about 3x richer. Based on our results, we concluded that fern conservation efforts should focus on fragments of Araucaria Forest inserted in the natural field, because the conversion of natural field into Pinus planting and cultivation of crops decreases ferns species both in the edges and forest interiors of the studied fragments, besides altering the phytosociological structure leading the communities to simplification.

Resumo Bordas florestais tipicamente exibem maior luminosidade e menor umidade que o interior florestal, resultando em um gradiente abiótico. Entretanto, o grau de diferença abiótica pode ser afetado a partir do tipo da matriz, influenciando a seleção de espécies. Comparamos a composição florística e a estrutura fitossociológica das comunidades de samambaias e licófitas na borda e interior de três sítios influenciados por diferentes matrizes (campo natural, plantio de Pinus e cultivo de olerícolas). Na região de Floresta com Araucária no Rio Grande do Sul, Brasil, foram sorteadas doze parcelas de 10 × 10 m na borda e no interior de cada sítio, totalizando 72 parcelas para avaliar o contraste fitossociológico, utilizando como parâmetro cobertura e riqueza das espécies por parcela para avaliar esse contraste. Registramos um total de 38 espécies nas áreas estudadas, distribuídas em 15 famílias. Os resultados mostraram que o efeito de borda atua em intensidades distintas nos sítios analisados. Nos sítios com matriz antropizada, a composição foi mais homogênea tanto nas bordas, quanto nos interiores e apresentou menor riqueza, demonstrando impacto mais pronunciado e profundo. Já no sítio com matriz de entorno natural, apesar da borda também apresentar baixa riqueza, o interior foi cerca de 3x mais rico. Sugerimos que os esforços de conservação de samambaias e licófitas em fragmentos com araucária, devem se concentrar em sítios inseridos em campo natural, pois, a conversão destes em plantio de Pinus e cultivo de olerícolas, diminui a diversidade dessas plantas, tanto nas bordas quanto nos interiores da floresta, além de alterar a estrutura fitossociológica levando as comunidades à simplificação.

Spatial distribution analysis of Dicksonia sellowiana Hook. in Araucaria forest fragments with different sizes / Análise da distribuição espacial de Dicksonia sellowiana Hook. em fragmentos de Floresta com Araucária com diferentes tamanhos

Abstract Dicksonia sellowiana Hook. (Dicksoniaceae) is target of extractive exploitation and is threatened with extinction. We analyzed the population structure, the spatial distribution pattern of D. sellowiana and its relationship with environmental parameters within three fragments of Araucaria Forest in Rio Grande do Sul, Brazil. The fragments are of different sizes, namely, large (H1LF) with 246 ha, medium (H2MF) with 57 ha and small (H3SF) with 5.2 ha. Within each site, 1 ha was delimited, divided into 100 subplots (100 m2), of which 20 were selected with a draw. In each subplot, counting of the individuals, the registration of the caudice height and the coverage of leaves (SC) (m2), measurements of photosynthetically active radiation (PAR), canopy opening degree (CO), soil moisture (SM) and litter thickness (LT). The temperature (T) was measured inside each site. A total of 792 plants were sampled, of which 551 were concentrated in H1LF, 108 in H2MF and 133 in H3SF. An average of 1320 ha-1 individuals were estimated. Of the total including the three fragments, 96.9% of the individuals are in the first class of height (up to 0.8 m), indicating a great potential of population development. The spatial distribution pattern (AI) was aggregated in the three populations and the plants presented a heterogeneous total coverage, between 4.73 m2 (H2MF) and 2,223.47 m2 (H1LF). The highest values ​​of SC and SM were more related to the distribution of individuals in H1LF whereas the opposite was recorded in H2MF. The highest values ​​of PAR, LT and CO correlated with the distribution of D. sellowiana in H3SF. In addition to revealing that the H1LF population is among the most dense in southern Brazil, the results demonstrated a significant structural distinction between the interior populations of the fragments, in spite of them being located near to one another and being part of the same natural field matrix.

Resumo Dicksonia sellowiana Hook. (Dicksoniaceae) é alvo de exploração extrativista e encontra-se ameaçada de extinção. Analisamos a estrutura populacional, o padrão de distribuição espacial de D. sellowiana e sua relação com parâmetros ambientais no interior de três fragmentos de Floresta com Araucária, no Rio Grande do Sul (RS), Brasil. Os fragmentos possuem diferentes tamanhos sendo denominados de grande (H1LF) com 246 ha, médio (H2MF) com 57 ha e de pequeno (H3SF) com 5,2 ha. No interior de cada sítio, foi demarcado 1 ha, fracionado em 100 subparcelas (100m2), das quais 20 foram sorteadas. Em cada subparcela foi feita a contagem dos indivíduos, o registro da altura do cáudice e da cobertura (SC) (m2) das folhas, as medições da radiação fotossinteticamente ativa (PAR), grau de abertura do dossel (CO), umidade do solo (SM) e espessura da serapilheira (LT). A temperatura (T) foi medida no interior de cada sítio. Foram amostradas 792 plantas, das quais 551 concentradas no H1LF, 108 no H2MF e 133 no H3SF e em média foram estimados 1320 indivíduos ha-1. Do total dos três fragmentos, 96,9% dos indivíduos estão na primeira classe de altura (até 0,8 m), indicando grande potencial de desenvolvimento das populações. O padrão de distribuição espacial (AI) foi agregado nas três populações e as plantas apresentaram uma cobertura total heterogênea, entre 4,73m2 (H2MF) e 2.223,47m 2 (H1LF). Os maiores valores de SC e de SM foram mais relacionadas com a distribuição dos indivíduos no H1LF enquanto que o contrário foi registrado no H2MF. Os maiores valores de PAR, LT e de CO relacionaram-se com a distribuição de D. sellowiana no H3SF. Além de revelar que a população do H1LF está entre as mais densas já descritas no sul do Brasil, os resultados demonstraram uma significativa distinção estrutural entre as populações dos interiores dos fragmentos com diferentes tamanhos, embora muito próximos geograficamente e inseridos em uma mesma matriz de campo natural.

Heterogeneity of fern communities in riparian forest remnants from the South Brazilian Campos (Pampa)

Abstract Riparian forests present biotic and abiotic factors that influence environmental dissimilarity, which reflect specific fern distribution. The purpose of this this study was to evaluate the environmental heterogeneity associated to the terrestrial fern communities in riparian forest remnants in the grasslands southern half of Rio Grande do Sul state . We sampled ten 5×5 m plots in each site (AI, AII and AIII), totaling 30 plots. In each plot, fern species were inventoried and vegetative, microclimatic and edaphic parameters were collected. A total of 24 species were surveyed in the three riparian forest remnants, distributed in 19 genera and 10 families. The Principal Components Analysis (PCA) showed that plots of AI had the highest temperature and aluminum values, while humidity was the lowest, which was reflected in the decrease of ferns richness. Soil moisture and air humidity were variables more related to the plots of AII and AII, indicating that these plants were favored in these environments. The floristic identity characteristic of each site suggests that many species are dependent to certain local environmental conditions. In this sense, even in very geographically close sites, riparian remnants deserve conservation attention, since they are capable of harboring high diversity in this grassland phytophysiognomy in southern Brazil. The results of this integrated study, with vegetation, climatic, and edaphic parameters, suggest, as expected, that ferns categorically respond to the heterogeneity shown by riparian environments, even when fragments are geographically very close to each other.

Resumo As florestas ripárias apresentam fatores bióticos e abióticos que influenciam a dissimilaridade ambiental, e que refletem a distribuição específica de samambaias. O objetivo deste trabalho foi avaliar a heterogeneidade ambiental associada às comunidades de samambaias terrícolas em remanescentes de mata ciliar dos campos da metade sul do estado do Rio Grande do Sul (Pampa). Foram amostradas dez parcelas de 5×5 m em cada sítio (AI, AII e AIII), totalizando 30 parcelas. Em cada quadro, foram inventariadas as espécies de samambaia, além de outros parâmetros vegetacionais, microclimáticos e edáficos. Um total de 24 espécies foram identificadas nos três remanescentes de mata ciliar, distribuídas em 19 gêneros e 10 famílias. A Análise de Componentes Principais (PCA) mostrou que as parcelas de AI apresentaram os maiores valores de temperatura e alumínio, enquanto a umidade foi a menor, o que se refletiu na diminuição da riqueza de samambaias. A umidade do solo e a umidade do ar foram as variáveis mais relacionadas às parcelas de AII e AIII, indicando que essas plantas foram favorecidas nesses. A identidade florística característica de cada local sugere que muitas espécies são dependentes de certas condições ambientais locais. Nesse sentido, mesmo em sítios geograficamente próximos, remanescentes de matas ciliares merecem atenção no que se refere a conservação, uma vez que são capazes de abrigar grande diversidade nesta fitofisionomia exclusiva do sul do Brasil. Os resultados deste estudo integrado, com parâmetros vegetacionais, climáticos e edáficos, sugerem, que as samambaias respondem categoricamente à heterogeneidade mostrada pelos ambientes ripários, mesmo quando os fragmentos estão próximos.

Importância do controle de qualidade para a redução das amostras insatisfatórias cérvico-vaginais / The importance of quality control to reduce unsatisfactory cervicl smears

O objetivo deste estudo foi analisar as não-conformidades analíticas dos exames citopatológicos realizados no Setor de Citologia Oncótica, da Divisão de Patologia do Instituto Adolfo Lutz (SCO-IAL), e discutir ações corretivas para minimizar essas ocorrências. O SCO-IAL recebeu 44.197 amostras citopatológicas cérvico-vaginais enviadas pelas Unidades de Saúde (US), de setembro de 2005 a fevereiro de 2007, que foram coradas pelo método de Papanicolaou e classificadas segundo a Nomenclatura Brasileira recomendada pelo Ministério da Saúde. Do total, 1.155 (2,61%) foram classificadas como insatisfatórias, sendo: 351 por artefatos de dessecamento; 198 pela presença de piócitos; 98 por material insuficiente; 47 pela presença de sangue e 12 por superposição celular. Em 449 casos, houve associação de duas ou mais causas; sendo o dessecamento presente em 351 casos. Das 198 amostras insatisfatórias pela presença de piócitos, 37 apresentaram agentes infecciosos. Observou-se também nesse mesmo período que dos 1.558(3.52%) casos de atipias de significado indeterminado, 371 foram limitados em seu diagnóstico. Os resultados obtidos demonstram que programas de treinamento nas US são de melhor estratégia para melhoria na qualidade das amostras. O controle de qualidade interno e externo, desde a colheita até a emissão dos laudos, é fundamental para o sucesso dos programas de rastreamento citológico.

Determinação do perfil protéico da membrana externa da Leptospira interrogans sorovariedade Hardjoprajitno / Protein profile of the outer membrane of Leptospira interrogans serovar Hardjoprajitno

Estudou-se o perfil das proteínas da membrana externa (PME) da Leptospira interrogans sorovariedade Hardjoprajitno por meio da eletroforese bidimensional. Foram utilizadas técnicas de extração das PME com Triton x114 e precipitação com acetona. Os géis foram corados com nitrato de prata e as imagens analisadas para determinação da massa molecular das proteínas detectadas. Foram visualizadas 35 bandas protéicas, sendo que cinco delas se destacaram por estarem em maior quantidade: 22,54KDa (LipL22), 30/26KDa (LipL32), 34,41KDa (PME34), 42,75KDa (LipL41) e 58,59KDa (LipL63).

The protein profile of the outer membrane of Leptospira interrogans serovar Hardjoprajitno was determined by two-dimensional gel electrophoresis. The outer membrane was extracted with Triton x 114 and the proteins were precipitated with acetone. The images were analyzed for the determination of the molecular weight of the detected proteins. Thirty-five spots for the proteins that are predominant in the outer membrane of this Leptospira were observed and five proteins were found in higher quantities: 22.54KDa (LipL22), 30/26KDa (LipL32), 34.41KDa (PME34) (2), 42.75KDa (LipL41), and 58.59KDa (LipL63).

Familial osteopetrosis in Agouti paca: report of nine cases / Osteopetrose familiar em Agouti paca: relato de nove casos

Nine cases of familial osteopetrosis were studied in Agouti paca rodents maintained in captivity. Animals were distributed in three groups depending on the severity of their skeletal lesions. Based upon clinical, radiological, and microscopic findings, it was concluded that one animal had level I lesions, three animals had level II lesions, and five animals had level III osteopetrosis and osteonecrosis. Throughout the entire axial and appendicular skeleton, there was an increased amount of both trabecular and cortical bone tissue. All analyzed bones showed thickened cortex and reduced medullary canals. Bone trabeculae were thick and confluent. Cortex showed a narrowing of Haversian canals. Numerous cementing lines resulted in typical mosaic patterns. Osteocytes were pycnotic. Osteonecrosis was characterized by the disappearance of osteocytes and bone matrix decomposition.

Descreveram-se nove casos de osteopetrose familiar em Agouti paca mantidas em cativeiro. Os animais foram distribuídos em três grupos de acordo com a gravidade das lesões do esqueleto. Com base nos exames clínico, radiológico e microscópico, foi concluído que um animal apresentou lesões de nível I, três animais tiveram lesões de nível II e cinco animais tiveram osteopetrose de nível III. Por todo o esqueleto axial e apendicular, a quantidade de osso trabecular e osteônico estava aumentada. Todos os ossos analisados mostraram córtex espesso e canais medulares reduzidos. As trabéculas ósseas eram espessas e confluentes. No córtex, verificou-se um estreitamento de canais de Havers. Numerosas linhas de cimentação resultaram em um padrão de mosaico típico. Osteócitos estavam picnóticos e a osteonecrose foi caracterizada pela morte dos osteócitos, com desintegração da matriz óssea.

Behavior of mesenchymal stem cells stained with 4', 6-diamidino-2-phenylindole dihydrochloride (DAPI) in osteogenic and non osteogenic cultures

4', 6-diamidino-2-phenylindole dihydrochloride (DAPI) is a DNA dye widely used to mark and trace stem cells in therapy. We here studied the effect of DAPI staining on the behavior of mesenchymal stem cells cultured in either a control, non-osteogenic medium or in an osteogenic differentiation medium. In the control medium, the number of stem cells/field, as well as the number of fluorescent cells/field increased up to the sixth day in both control and DAPI-treated cultures. Afterwards, both the number of fluorescent cells and their fluorescence intensity decreased. Control cells were fusiform and with some long extensions that apparently linked them to neighboring cells, while DAPI-treated cells were mostly round cells with fine and short extensions. The trypan-blue exclusion method showed 99% cell viability in both groups, however, both alkaline phosphatase activity and the thiazolyl blue formazan assay (indicative of mitochondrial metabolism) gave significantly lower values in DAPI-marked cells The mitochondrial mass, as indicated by specific staining and flow cytometry, showed no differences between groups. Mesenchymal stem cells gave origin to mineralized nodules in the osteogenic differentiation medium and there were not DAPI-marked cells on the ninth day of culture. Alkaline phosphatase activity, viability assay and number of cells/field and of mineralized nodules/field were similar in both groups. So, DAPI treatment did not change cell viability and proliferation during osteogenic differentiation of mesenchymal stem cells. However, since these cells loose DAPI marking after 9 days in osteogenic cultures suggests that DAPI may not be an effective marker for mesenchymal stem cells implanted in bone tissue for long periods.

Circadian rhythms in blood pressure in free-ranging three-toed sloths (Bradypus variegatus)

Blood pressure (BP) profiles were monitored in nine free-ranging sloths (Bradypus variegatus) by coupling one common carotid artery to a BP telemetry transmitter. Animals moved freely in an isolated and temperature-controlled room (24ºC) with 12/12-h artificial light-dark cycles and behaviors were observed during resting, eating and moving. Systolic (SBP) and diastolic (DBP) blood pressures were sampled for 1 min every 15 min for 24 h. BP rhythm over 24 h was analyzed by the cosinor method and the mesor, amplitude, acrophase and percent rhythm were calculated. A total of 764 measurements were made in the light cycle and 721 in the dark cycle. Twenty-four-hour values (mean ± SD) were obtained for SBP (121 ± 22 mmHg), DBP (86 ± 17 mmHg), mean BP (MBP, 98 ± 18 mmHg) and heart rate (73 ± 16 bpm). The SBP, DBP and MBP were significantly higher (unpaired Student t-test) during the light period (125 ± 21, 88 ± 15 and 100 ± 17 mmHg, respectively) than during the dark period (120 ± 21, 85 ± 17 and 97 ± 17 mmHg, respectively) and the acrophase occurred between 16:00 and 17:45 h. This circadian variation is similar to that observed in cats, dogs and marmosets. The BP decreased during "behavioral sleep" (MBP down from 110 ± 19 to 90 ± 19 mmHg at 21:00 to 8:00 h). Both feeding and moving induced an increase in MBP (96 ± 17 to 119 ± 17 mmHg at 17:00 h and 97 ± 19 to 105 ± 12 mmHg at 15:00 h, respectively). The results show that conscious sloths present biphasic circadian fluctuations in BP levels, which are higher during the light period and are mainly synchronized with feeding

Biosensor de ácido úrico para determinaçäo em fluxo contínuo / Uric acid biosensor for continuous flow determination

O objetivo deste trabalho foi desenvolver um biosensor para dosagens de ácido úrico no soro humano. A uricase foi imobilizada em pasta de grafite modificada usando TCNQ como mediador e então, pressionada sobre um eletrodo de outo. A corrente elétrica produzida pela reação enzimática foi diretamente proporcional à concentração de ácido úrico presente na amostra. Este sistema demonstrou uma sensibilidade linear entre 12.5 muM a 250 muM de solução de ácido úrico. O sistema foi testado usando medições em fluxo contínuo (FIA).

The aim of this work was to develop a biosensor to determine uric acid concentration in human serum. Uricase was immobilized in modified graphite paste using TCNQ as a mediator and then packed onto a gold electrode. The current produced by the enzyme reaction was proportional to the uric acid concentration in the sample. The response of this system showed a linear sensivity between concentrations of 12.5 µM and 250 ~tM uric acid solutions. The system was tested using flow injection analysis (FIA).

Renal effect of gentamicin in diabetic rats

To evaluate the protective effect of diabetes mellitus (DM) on renal function of rats treated with gentamicin (GM), male Wistar-EPM rats (250-350 g) were treated with streptozotocin (SZ; 45 mg/kg) and starting 10 days after induction of diabetes, GM was given for ten consecutive days at a daily dose of 40 mg/kg. In the GM-treated group (G), a significant fall in inulin and sodium-p-aminohippurate clearance was obtained (3.57 + or - 0.16 and 12.59 + or - 0.61 ml min-1kg-1 vs 6.43 + or - 0.21 and 17.98 + or - 0.47 ml min-1 kg-1 in control rats (C), respectively) while in the animals previously injected with SZ (diabetic + gentamicin, DG group) these changes injected with SZ (diabetic + gentamicin, DG group) these changes were not observed. The diabetic (D), g and DG group showed a significant rise in urinary flow compared to C (0.165 + or - 0.009, 0.145 + or - 0.007 and 0.173 + or - 0.009 ml min-1kg-1 vs 0.109 + or - 0.003 ml min-1kg-1, respectively); however, only in G was the U/P inulin ration significantly decreased when compared to C. The fractional excretion (FE) of sodium and postassium was significantly augmented in G when compared to C, D and DG. Thus, diabetes protected against gentamicin nephrotoxicity at both the glomerular and tubular level, although it did not promote a reduction in urinary flow

Lactoferrin levels and unsaturated iron-binding capacity in colostrum of Brazilian women of two socioecomic levels

The objetive of this study was to compare lactoferrin (LF) levels and unsaturated iron-binding capacity (UIBC) of colostrum from Brazilian women aged 20-38 years of low (N = 28) and high (N = 15) socioeconomic level. Both groups received a similar amount of supplental iron (25-65 mg/day) during pregnancy. We also determined the relationship between LF levels and UIBC, and between these components and maternal iron status. Both groups (low and high socieconomic level) showed adequate and similar mean hematocrit (35.0 ñ 13% and 35.9 ñ 1.3%, respectively) and serum ferritin (64 ñ 12 µg/1 and 57 ñ 12 µg/1, respectively) levels. Furthermore, LF levels (5.7 ñ 0.9 mg/ml and 5.5 ñ 0.6 mg/ml) and UIBC (3.8 ñ 0.3 µg/ml and 3/1 ñ 0.3 µg/ml) were not significantly different in the two groups of women, nor were they related to maternal hematocrit or serum ferritin. UIBC was significantly (P = 0.009), although weakly positively correlated (r= 0.45) with LF levels, suggesting that other colostrum ligands may contribute substantially to the capacity of colostrum to bind exogenous iron

Function and morphometric evaluation of intrauterine undernutrition on kidney development of the progeny

Renal function and renal morphometry of the progeny of rats submitted to 50% dietary restriction (pairfed with control group) throughout pregnancy (Rtgroup), during the first half of pregnancy (R1 group) or during the second half of pregnancy (R2 group) were studied 3 months after birth. Glomerular filtration rate (GFR) and renal plasma flow (RPF) decrease significantly in all groups when compared to control (C) (GFR, 4.44 ñ 0.12, 4.04 ñ 0.18, and 4.00 ñ 0.16 vs 6.87 ñ 0.17, and RPF, 19.06 ñ0.57, 17.00 ñ 1.14, and 13.31 ñ0.50 vs 22.57 ñ 0.67, respectively). Urinary osmolality tended to be lower in the R2 and Rt groups (887.1 ñ 42.36 and 868.0 ñ 42.36 vs 975.1 ñ 38.31 in C), and the net acid excretion calculated per ml of GFR was either maintained or stimulated (R1 group). A significant decline in the number of glomeruli occurred in R1, R2 and Rt rats (79.84 ñ 2.08, 62.30 ñ 2.07, and 58.16 ñ 2.32 vs 99.77 ñ 2.28 in C repectively). The results show that intrauterine undernutrition actually caused a deleterious effect on the number of functional nephrons