The Experts below are selected from a list of 264 Experts worldwide ranked by ideXlab platform
Loreta B Freitas - One of the best experts on this subject based on the ideXlab platform.
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effects of past climate on passiflora Actinia passifloraceae populations and insights into future species management in the brazilian atlantic forest
Botanical Journal of the Linnean Society, 2016Co-Authors: Marcelo Costa Teixeira, Geraldo Mader, Gustavo A Silvaarias, Sandro L Bonatto, Loreta B FreitasAbstract:The Brazilian Atlantic Rainforest is one of the most diverse and threatened ecoregions on the planet and displays high levels of endemism. Despite several population analyses and phylogeographical studies, the origins of its species richness and the evolutionary processes that gave rise to this diversification remain poorly understood, especially at the southern edge of the Atlantic Forest. Passiflora Actinia is an indigenous species from the southern Atlantic Forest and, as such, was influenced by climatic changes during the Pleistocene. In this study, we investigated the effects of past climate changes on the genetic diversity of P. Actinia, using nuclear and plastid markers. We subsequently suggest strategies for the preservation of this species in particular and the whole ecoregion in general. We employed phylogeographical methods and combined these results with past, present and future ensemble niche models. Genetic variability in P. Actinia was similar to that of other species with similar geographical distributions, and geographical structuring was not observed based on either type of genetic marker. Diversification in P. Actinia was dated to the Pleistocene, suggesting that climate changes could have influenced the distribution of genetic diversity in this species. Our results predicted that suitable P. Actinia habitat will persist in the highlands but will be reduced in the lowlands, especially with higher greenhouse gas concentrations. Conservation efforts should focus on populations with unique genetic units and populations from areas with greater climatic instability. Habitat loss due to deforestation in the Atlantic Forest constitutes a major risk to this species, especially to small populations or those with low diversity indices.
Marcelo Costa Teixeira - One of the best experts on this subject based on the ideXlab platform.
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effects of past climate on passiflora Actinia passifloraceae populations and insights into future species management in the brazilian atlantic forest
Botanical Journal of the Linnean Society, 2016Co-Authors: Marcelo Costa Teixeira, Geraldo Mader, Gustavo A Silvaarias, Sandro L Bonatto, Loreta B FreitasAbstract:The Brazilian Atlantic Rainforest is one of the most diverse and threatened ecoregions on the planet and displays high levels of endemism. Despite several population analyses and phylogeographical studies, the origins of its species richness and the evolutionary processes that gave rise to this diversification remain poorly understood, especially at the southern edge of the Atlantic Forest. Passiflora Actinia is an indigenous species from the southern Atlantic Forest and, as such, was influenced by climatic changes during the Pleistocene. In this study, we investigated the effects of past climate changes on the genetic diversity of P. Actinia, using nuclear and plastid markers. We subsequently suggest strategies for the preservation of this species in particular and the whole ecoregion in general. We employed phylogeographical methods and combined these results with past, present and future ensemble niche models. Genetic variability in P. Actinia was similar to that of other species with similar geographical distributions, and geographical structuring was not observed based on either type of genetic marker. Diversification in P. Actinia was dated to the Pleistocene, suggesting that climate changes could have influenced the distribution of genetic diversity in this species. Our results predicted that suitable P. Actinia habitat will persist in the highlands but will be reduced in the lowlands, especially with higher greenhouse gas concentrations. Conservation efforts should focus on populations with unique genetic units and populations from areas with greater climatic instability. Habitat loss due to deforestation in the Atlantic Forest constitutes a major risk to this species, especially to small populations or those with low diversity indices.
Darl R. Swartz - One of the best experts on this subject based on the ideXlab platform.
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EXCHANGE OF ALPHA -ACTININ IN ISOLATED RIGOR MYOFIBRILS
Journal of Muscle Research and Cell Motility, 1999Co-Authors: Darl R. SwartzAbstract:In the current study, the process of α-actinin binding to the myofibrillar Z-line was investigated to determine its mechanism. Pretreatment of rigor myofibrils with unlabeled α-actinin did not prevent or slow the incorporation of fluorescein skeletal α-actinin into myofibrils suggesting that incorporation was not the filling of empty binding sites but rather an exchange reaction. Further support for this was obtained using quantitative measures of labeled α-actinin incorporation and measures of total myofibrillar α-actinin. These results showed that there was no change in myofibrillar α-actinin content when up to 15% of the total α-actinin was the labeled protein. Measurement of the time-course of fluorescein α-actinin incorporation by quantitative fluorescence microscopy showed that the increase in Z-line fluorescence was well described by a rapid (unresolved) incorporation of fluorescence followed by a much slower phase. The slower phase was independent of fluorescein α-actinin concentration (2.5–160 nM) and had an apparent rate of 0.008–0.016 min−1. Pretreatment of myofibrils with fluorescein α-actinin followed by incubation with unlabeled α-actinin resulted in a decrease in Z-line fluorescence with an apparent rate of 0.021 min−1. The slow phase was interpreted as representing the dissociation rate of intrinsic Z-line α-actinin. Thus, the dissociation rate for the in situ interaction of α-actinin with actin appears to be three orders of magnitude slower than that determined from solution studies.
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Exchange of α-actinin in isolated rigor myofibrils
Journal of Muscle Research & Cell Motility, 1999Co-Authors: Darl R. SwartzAbstract:In the current study, the process of α-actinin binding to the myofibrillar Z-line was investigated to determine its mechanism. Pretreatment of rigor myofibrils with unlabeled α-actinin did not prevent or slow the incorporation of fluorescein skeletal α-actinin into myofibrils suggesting that incorporation was not the filling of empty binding sites but rather an exchange reaction. Further support for this was obtained using quantitative measures of labeled α-actinin incorporation and measures of total myofibrillar α-actinin. These results showed that there was no change in myofibrillar α-actinin content when up to 15% of the total α-actinin was the labeled protein. Measurement of the time-course of fluorescein α-actinin incorporation by quantitative fluorescence microscopy showed that the increase in Z-line fluorescence was well described by a rapid (unresolved) incorporation of fluorescence followed by a much slower phase. The slower phase was independent of fluorescein α-actinin concentration (2.5–160 nM) and had an apparent rate of 0.008–0.016 min^−1. Pretreatment of myofibrils with fluorescein α-actinin followed by incubation with unlabeled α-actinin resulted in a decrease in Z-line fluorescence with an apparent rate of 0.021 min^−1. The slow phase was interpreted as representing the dissociation rate of intrinsic Z-line α-actinin. Thus, the dissociation rate for the in situ interaction of α-actinin with actin appears to be three orders of magnitude slower than that determined from solution studies.
Geraldo Mader - One of the best experts on this subject based on the ideXlab platform.
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effects of past climate on passiflora Actinia passifloraceae populations and insights into future species management in the brazilian atlantic forest
Botanical Journal of the Linnean Society, 2016Co-Authors: Marcelo Costa Teixeira, Geraldo Mader, Gustavo A Silvaarias, Sandro L Bonatto, Loreta B FreitasAbstract:The Brazilian Atlantic Rainforest is one of the most diverse and threatened ecoregions on the planet and displays high levels of endemism. Despite several population analyses and phylogeographical studies, the origins of its species richness and the evolutionary processes that gave rise to this diversification remain poorly understood, especially at the southern edge of the Atlantic Forest. Passiflora Actinia is an indigenous species from the southern Atlantic Forest and, as such, was influenced by climatic changes during the Pleistocene. In this study, we investigated the effects of past climate changes on the genetic diversity of P. Actinia, using nuclear and plastid markers. We subsequently suggest strategies for the preservation of this species in particular and the whole ecoregion in general. We employed phylogeographical methods and combined these results with past, present and future ensemble niche models. Genetic variability in P. Actinia was similar to that of other species with similar geographical distributions, and geographical structuring was not observed based on either type of genetic marker. Diversification in P. Actinia was dated to the Pleistocene, suggesting that climate changes could have influenced the distribution of genetic diversity in this species. Our results predicted that suitable P. Actinia habitat will persist in the highlands but will be reduced in the lowlands, especially with higher greenhouse gas concentrations. Conservation efforts should focus on populations with unique genetic units and populations from areas with greater climatic instability. Habitat loss due to deforestation in the Atlantic Forest constitutes a major risk to this species, especially to small populations or those with low diversity indices.
Sandro L Bonatto - One of the best experts on this subject based on the ideXlab platform.
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effects of past climate on passiflora Actinia passifloraceae populations and insights into future species management in the brazilian atlantic forest
Botanical Journal of the Linnean Society, 2016Co-Authors: Marcelo Costa Teixeira, Geraldo Mader, Gustavo A Silvaarias, Sandro L Bonatto, Loreta B FreitasAbstract:The Brazilian Atlantic Rainforest is one of the most diverse and threatened ecoregions on the planet and displays high levels of endemism. Despite several population analyses and phylogeographical studies, the origins of its species richness and the evolutionary processes that gave rise to this diversification remain poorly understood, especially at the southern edge of the Atlantic Forest. Passiflora Actinia is an indigenous species from the southern Atlantic Forest and, as such, was influenced by climatic changes during the Pleistocene. In this study, we investigated the effects of past climate changes on the genetic diversity of P. Actinia, using nuclear and plastid markers. We subsequently suggest strategies for the preservation of this species in particular and the whole ecoregion in general. We employed phylogeographical methods and combined these results with past, present and future ensemble niche models. Genetic variability in P. Actinia was similar to that of other species with similar geographical distributions, and geographical structuring was not observed based on either type of genetic marker. Diversification in P. Actinia was dated to the Pleistocene, suggesting that climate changes could have influenced the distribution of genetic diversity in this species. Our results predicted that suitable P. Actinia habitat will persist in the highlands but will be reduced in the lowlands, especially with higher greenhouse gas concentrations. Conservation efforts should focus on populations with unique genetic units and populations from areas with greater climatic instability. Habitat loss due to deforestation in the Atlantic Forest constitutes a major risk to this species, especially to small populations or those with low diversity indices.
