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1.
Braz. j. biol ; 83: e245386, 2023. tab, graf
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1278528

RESUMO

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.

2.
Braz J Med Biol Res ; 54(10): e10669, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34287576

RESUMO

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.


Assuntos
Obesidade , Condicionamento Físico Animal , Animais , Dieta Hiperlipídica/efeitos adversos , Coração , Masculino , Ratos , Ratos Wistar
3.
Braz J Biol ; 83: e245386, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34161461

RESUMO

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.


Assuntos
Gleiquênias , Herbivoria , Brasil , Florestas , Humanos , Folhas de Planta
4.
Braz J Microbiol ; 52(2): 587-596, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33651332

RESUMO

Three culture media were studied for red pigment production by Monascus ruber in submerged cultivation: rice flour (20 g L-1), sugarcane molasses (30 g L-1), and, finally, molasses + rice flour (10 g L-1+10 g L-1); all culture media were added of 5 g L-1 glycine as nitrogen source. Rice flour showed pigment production of 7.05 UA510nm and molasses 5.08 UA510nm, and the mixture of rice flour and molasses showed the best result of 16.38 UA510nm. Molasses culture presented good results for cell biomass production of 11.09 g L-1. With these results, it was observed that one substrate presented good pigment production (rice flour) and another attained better results for cell biomass growth (molasses), and a third medium containing 10 g L-1 of rice flour + 10 g L-1 of molasses was formulated. The results for this mixture showed satisfactory results, with global pigment productivity of 0.097 UA510nm h-1 and maximum productivity rate of 0.17 UA510nm h-1. The high production and productivity obtained for the mixture of rice flour and molasses indicated that the production of red pigment by submerged fermentation, using the mixture of these low-cost culture media, may be promising in terms of commercial production.

5.
Braz J Med Biol Res ; 54(4): e10138, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33624728

RESUMO

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.


Assuntos
Cálcio , Remodelação Ventricular , Animais , Cálcio/metabolismo , Homeostase , Masculino , Ratos , Ratos Wistar , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo
6.
Braz. j. med. biol. res ; 54(4): e10138, 2021. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1153533

RESUMO

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.

7.
Braz. j. biol ; 80(4): 803-813, Oct.-Dec. 2020. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1142536

RESUMO

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.

8.
Braz. j. biol ; 80(1): 199-205, Feb. 2020. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1089283
9.
Braz J Biol ; 80(4): 803-813, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31800765

RESUMO

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.


Assuntos
Gleiquênias , Biodiversidade , Brasil , Florestas , Humanos , Solo
11.
Braz. j. biol ; 79(3): 495-504, July-Sept. 2019. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1001457

RESUMO

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.


Assuntos
Florestas , Gleiquênias , Lycopodiaceae , Biota , Brasil
12.
Braz. j. biol ; 79(2): 337-344, Apr.-June 2019. tab, graf
Artigo em Inglês | LILACS | ID: biblio-989444

RESUMO

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.


Assuntos
Espécies em Perigo de Extinção/estatística & dados numéricos , Dispersão Vegetal/fisiologia , Traqueófitas/fisiologia , Temperatura , Brasil , Florestas , Ecossistema , Folhas de Planta
14.
Braz J Biol ; 79(3): 495-504, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30304255

RESUMO

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.


Assuntos
Biota , Gleiquênias , Florestas , Lycopodiaceae , Brasil
16.
Braz J Biol ; 79(2): 337-344, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30133559

RESUMO

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.


Assuntos
Espécies em Perigo de Extinção/estatística & dados numéricos , Dispersão Vegetal/fisiologia , Traqueófitas/fisiologia , Brasil , Ecossistema , Florestas , Folhas de Planta , Temperatura
17.
J Anim Physiol Anim Nutr (Berl) ; 102(1): 122-130, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28032379

RESUMO

Changes in physiological parameters that are induced by acute exercise on a treadmill in healthy military dogs have not been thoroughly investigated, especially with regard to age. This study investigated the effects of acute exercise on a treadmill on cardiovascular function, biochemical parameters and gastric antral motility in military dogs. Thermography was used to assess variations in superficial hindlimb muscle temperature. Nine healthy dogs were distributed into three groups according to their age (Group I: 25 ± 7 months; Group II: 51 ± 12 months; Group III: 95 ± 10 months) and sequentially subjected to running exercise on a treadmill for 12 min (3.2 km/h at 0° incline for 4 min, 6.4 km/h at 0° incline for 4 min and 6.4 km/h at 10° incline for 4 min). Heart rate, systolic and diastolic arterial pressure (DAP), gastric motility, haematocrit and biochemical analyses were performed at rest and after each session of treadmill exercise. Infrared thermographic images of muscles in the pelvic member were taken. Exercise decreased DAP in Group I, increased systolic arterial pressure in Groups II and III and increased mean arterial pressure in Group III (all p < 0.05). After the exercise protocol, plasma creatine kinase and aspartate aminotransferase levels increased only in Group I (p < 0.05). Exercise increased heart rate and decreased the gastric motility of a solid meal at 180 min in all groups (all p < 0.05). Exercise also elevated temperature in the femoral biceps muscles in Group I compared with the older dogs. The results indicate that acute exercise decreased gastric motility in dogs, regardless of age, and caused more pronounced cardiovascular changes in older dogs than in younger dogs. Acute exercise also altered biochemical parameters and superficial hindlimb muscle temperature in younger military dogs.


Assuntos
Pressão Sanguínea , Temperatura Corporal/fisiologia , Cães/fisiologia , Motilidade Gastrointestinal/fisiologia , Frequência Cardíaca , Condicionamento Físico Animal/fisiologia , Animais , Teste de Esforço/veterinária , Masculino , Militares , Músculo Esquelético/fisiologia , Esforço Físico
18.
Genet Mol Res ; 14(4): 14752-9, 2015 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-26600536

RESUMO

Even though several in vitro studies have focused on bacterial biology, the extent of such knowledge is not complete when considering an actual infection. As culture-independent microbiology methods such as high-throughput sequencing became available, important aspects of host-bacterium interactions will be elucidated. Based on microbiological relevance, we considered Bacteroides fragilis in a murine experimental infection as a model system to evaluate the in vivo bacterial transcriptome in host exudates. A disproportionate number of reads belonging to the host genome were retrieved in the first round of pyrosequencing, even after depletion of ribosomal RNA; the average number of reads related to the eukaryotic genome was 71.924-67.7%, whereas prokaryotic reads represented 34.338-32.3% in host exudates. Thus, different treatments were used to improve the prokaryotic RNA yield: i) centrifugation; ii) ultrasonic treatment; and iii) ultrasonic treatment followed by centrifugation. The latter treatment was found to be the most efficient in generating bacterial yields, as it resulted in a higher number of Bacteroides cells. However, the RNA extracted after this treatment was not of sufficient quality to be used in cDNA synthesis. Our results suggest that the methodology routinely used for RNA extraction in transcriptional analysis is not appropriate for in vivo studies in complex samples. Furthermore, the most efficient treatment for generating good bacterial cell yields was not suitable to retrieve high-quality RNA. Therefore, as an alternative methodological approach to enable in vivo studies on host-bacterium interactions, we advise increasing the sequencing depth despite the high costs.


Assuntos
Bacteroides fragilis/genética , Perfilação da Expressão Gênica/métodos , RNA Mensageiro/genética , Transcriptoma/genética , Animais , Bacteroides fragilis/patogenicidade , Regulação Bacteriana da Expressão Gênica/genética , Biblioteca Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Camundongos , RNA Mensageiro/isolamento & purificação , Análise de Sequência de RNA
19.
Biotechnol Adv ; 33(8): 1715-26, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26384475

RESUMO

Despite the numerous advantages of biosurfactants, such as low toxicity, biodegradability and high stability, these compounds are not widely used because of the high cost of production. Details about genetics, regulation and biosynthesis of rhamnolipids by Pseudomonas aeruginosa, are extremely important to the development of bioprocesses involving the synthesis of these compounds. The holding of such knowledge associated with the use of metabolic engineering tools allow modification of producing strains and the development of synthetic routes, with the purpose of increasing the production of rhamnolipids. Considering the need to obtain this know-how, this review provides information on the rhamnolipids, covering genetics, biosynthesis of hydrophobic and hydrophilic portions, and regulation, plus some future strategies that would contribute to the expansion of the production of this green surfactant.


Assuntos
Glicolipídeos/biossíntese , Engenharia Metabólica , Tensoativos/química , Glicolipídeos/química , Glicolipídeos/genética , Interações Hidrofóbicas e Hidrofílicas , Indústrias , Pseudomonas aeruginosa/química
20.
J Sports Med Phys Fitness ; 55(5): 383-9, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-26068323

RESUMO

AIM: The aim of the present study was to evaluate the effect of oral caffeine ingestion during repeated sets of resistance. METHODS: Fourteen moderately resistance-trained men (20.9 ± 0.36 years and 77.62 ± 2.07 kg of body weight) ingested a dose of caffeine (5 mg.kg-1) or placebo prior to 3 sets of bench press and 3 sets of leg press exercises, respectively. The study used a double-blind, counterbalanced, crossover design. Repetitions completed and total weight lifted were recorded in each set. Readiness to invest in both physical (RTIPE) and mental (RTIME) effort were assessed prior each set, and rating of perceived exertion (RPE) was recorded after each set. Rest and peak heart rates were determined via telemetry. RESULTS: Caffeine ingestion result in increased number of repetitions to failure in bench press (F[1,13]=6.16, P=0.027) and leg press (F[1,13]=9.33, P=0.009) compared to placebo. The sum of repetitions performed in the 3 sets was 11.60% higher in bench press (26.86 ± 1.74; caffeine: 30.00 ± 1.87; P=0.027) and 19.10% in leg press (placebo: 40.0 ± 4.22; caffeine: 47.64 ± 4.69; P=0.009). Also, RTIME was increased in the caffeine condition both in bench press (F[1,13]=7.02, P=0.02) and in leg press (F[1,13]=5.41, P=0.03). There were no differences in RPE, RTIPE and HR (P>0.05) across conditions. CONCLUSION: Acute caffeine ingestion can improve performance in repeated sets to failure and increase RTIME in resistance-trained men.


Assuntos
Desempenho Atlético , Cafeína/administração & dosagem , Resistência Física/efeitos dos fármacos , Treinamento de Força/métodos , Levantamento de Peso/fisiologia , Adolescente , Adulto , Estimulantes do Sistema Nervoso Central/administração & dosagem , Estudos Cross-Over , Método Duplo-Cego , Frequência Cardíaca/efeitos dos fármacos , Frequência Cardíaca/fisiologia , Humanos , Masculino , Valores de Referência , Adulto Jovem
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