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Helena C. Morais - One of the best experts on this subject based on the ideXlab platform.
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Leaf traits and herbivory on Deciduous and evergreen trees in a tropical dry forest
Basic and Applied Ecology, 2015Co-Authors: Jhonathan O. Silva, Mário M. Espírito-santo, Helena C. MoraisAbstract:Abstract Deciduous and evergreen trees coexist in tropical dry forests, but exhibit distinct leaf syndromes for resource-use efficiency and defenses against herbivores. Moreover, these functional groups may have contrasting patterns of temporal variation in leaf traits and herbivory along leaf ontogeny. We tested these predictions by comparing a set of leaf traits related to water stress and defense, and herbivory levels between young and mature leaves from evergreen leaf-exchanger and Deciduous species. We evaluated Deciduous and evergreen trees within the same habitat type: a tropical dry forest with 90–100% of leaf Deciduousness during the dry season. We sampled 10 individuals of three Deciduous and three evergreen species. Evergreen plants had greater leaf thickness and concentration of phenolics and tannins. On the other hand, Deciduous plants had higher leaf nitrogen content and specific leaf area. Deciduous plants lost twice as much leaf area by herbivory as evergreen plants (6.48% versus 3.20%), and leaf damage was positively related to both phenolic compounds and nitrogen content. Mature leaves from both phenological groups had higher levels of tannins and phenolic compounds, and lower levels of nitrogen and herbivory increment than young leaves. Our results suggest an adaptive convergence on leaf traits primarily related to water stress for different species within each phenological group. Some of these traits also play a role in leaf palatability, although the fitness consequences of the absolute difference in leaf damage (approximately 3%) between evergreen and Deciduous species remain unclear.
Hitoyata Shimokawa - One of the best experts on this subject based on the ideXlab platform.
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Bovine dentine organic matrix down-regulates osteoclast activity
Journal of Bone and Mineral Metabolism, 2009Co-Authors: Wantida Sriarj, Kazuhiro Aoki, Keiichi Ohya, Yuzo Takagi, Hitoyata ShimokawaAbstract:Physiological root resorption is a phenomenon that normally takes place in Deciduous teeth; root resorption of permanent teeth occurs only under pathological conditions. The molecular mechanisms underlying these processes are still unclear. Our previous study showed that osteoclasts cultured on Deciduous dentine exhibited a higher degree of resorption and higher levels of cathepsin K and MMP-9 mRNA than osteoclasts cultured on permanent dentine. These results could be because of different susceptibilities to acid and the different organic matrices between Deciduous and permanent dentine. Thus, the purpose of this study was to investigate the effect of dentine extracts from bovine Deciduous and permanent dentine on osteoclast activity. Osteoclasts, obtained from mouse bone marrow cells co-cultured with an osteoblast-rich fraction in the presence of 1,25-(OH)_2-vitamin D3 and PGE2, were incubated with or without 0.6 M HCl extracts from bovine Deciduous or permanent dentine for 48 h. TRAP positive cell number, TRAP activity, the areas of resorption pits, and mRNA levels of TRAP, v-ATPase, calcitonin receptor, cathepsin K, and MMP-9 were examined. The results illustrated that TRAP activity, the resorbed area, and the mRNA levels of osteoclast marker genes seemed to be suppressed by both Deciduous and permanent dentine extracts. These findings indicate that some factors that suppress osteoclast activity are contained in both Deciduous and permanent dentine extracts. Although there was no significant difference in osteoclast activity between Deciduous and permanent dentine extracts, osteoclasts incubated with permanent dentine extracts tend to exhibit less resorption activity than those incubated with Deciduous dentine extracts. However, we could not clearly explain the causes of this.
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Bovine dentine organic matrix down-regulates osteoclast activity
Journal of Bone and Mineral Metabolism, 2009Co-Authors: Wantida Sriarj, Kazuhiro Aoki, Keiichi Ohya, Yuzo Takagi, Hitoyata ShimokawaAbstract:Physiological root resorption is a phenomenon that normally takes place in Deciduous teeth; root resorption of permanent teeth occurs only under pathological conditions. The molecular mechanisms underlying these processes are still unclear. Our previous study showed that osteoclasts cultured on Deciduous dentine exhibited a higher degree of resorption and higher levels of cathepsin K and MMP-9 mRNA than osteoclasts cultured on permanent dentine. These results could be because of different susceptibilities to acid and the different organic matrices between Deciduous and permanent dentine. Thus, the purpose of this study was to investigate the effect of dentine extracts from bovine Deciduous and permanent dentine on osteoclast activity. Osteoclasts, obtained from mouse bone marrow cells co-cultured with an osteoblast-rich fraction in the presence of 1,25-(OH)_2-vitamin D3 and PGE2, were incubated with or without 0.6 M HCl extracts from bovine Deciduous or permanent dentine for 48 h. TRAP positive cell number, TRAP activity, the areas of resorption pits, and mRNA levels of TRAP, v-ATPase, calcitonin receptor, cathepsin K, and MMP-9 were examined. The results illustrated that TRAP activity, the resorbed area, and the mRNA levels of osteoclast marker genes seemed to be suppressed by both Deciduous and permanent dentine extracts. These findings indicate that some factors that suppress osteoclast activity are contained in both Deciduous and permanent dentine extracts. Although there was no significant difference in osteoclast activity between Deciduous and permanent dentine extracts, osteoclasts incubated with permanent dentine extracts tend to exhibit less resorption activity than those incubated with Deciduous dentine extracts. However, we could not clearly explain the causes of this.
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Bovine Deciduous dentine is more susceptible to osteoclastic resorption than permanent dentine: results of quantitative analyses
Journal of Bone and Mineral Metabolism, 2006Co-Authors: Bobby John Varghese, Kazuhiro Aoki, Keiichi Ohya, Hitoyata Shimokawa, Yuzo TakagiAbstract:Many clinical reports suggest that Deciduous teeth exhibit a greater susceptibility to resorption than permanent ones. To examine the difference between Deciduous and permanent dentine in their susceptibility to osteoclastic resorption, osteoclast-like cells (OCLs) were cultured on Deciduous and permanent dentine slices. The number, area, depth, and volume of resorption pits were then measured, using image-analyzing systems. We measured the level of degraded collagen (cross-linked N-telopeptide of type I collagen; NTx) in culture medium using an enzyme-linked immunosorbent assay (ELISA). The levels of cathepsin K, matrix metallo proteinase (MMP)-9, and MMP-13 mRNAs in the cells attached to dentine were also analyzed by real-time reverse transcription polymerase chain reaction (RT-PCR). Deciduous dentine slices exhibited a significant (twofold) increase in resorbed area compared with the permanent slices. Three-dimensional analysis revealed that the volume of pits in Deciduous dentine differed significantly (fourfold) compared to that in the permanent dentine. The depth of pits also followed the same trend. However, there was no significant difference in the number of pits or osteoclasts on the dentine slices. The NTx level in Deciduous media was significantly more than that in permanent media. The mRNA levels also followed the same trend. These results suggest that Deciduous dentine is more susceptible to resorption than permanent dentine and signals from the substrate play an important role in physiological resorption.
Noriyuki Osada - One of the best experts on this subject based on the ideXlab platform.
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Intraspecific variation in spring leaf phenology and duration of leaf expansion in relation to leaf habit and leaf size of temperate tree species
Plant Ecology, 2020Co-Authors: Noriyuki OsadaAbstract:Spring leaf phenology has been intensively studied in temperate Deciduous broad-leaved tree species, but the phenology of evergreen broad-leaved tree species has seldom been focused on. Evaluation of the difference in spring leaf phenology between coexisting Deciduous and evergreen species is essential to predict their responses to climate change. In this study, spring leaf phenology was investigated for the 12 Deciduous and 12 evergreen broad-leaved species coexisting in a warm-temperate forest in Japan, based on the predictions that selection pressure for earlier leaf production in spring results in less intraspecific variation in phenology at a given timing (SD_max) and a shorter duration of leaf expansion in Deciduous than in evergreen species. In contrast to this prediction, SD_max did not differ between Deciduous and evergreen species and was not related to leaf area or LMA. On the other hand, the duration of leaf expansion was longer in evergreen than in Deciduous species, and was positively correlated with LMA. The leaves of greater LMA required longer periods of leaf expansion, probably due to a higher cost of and/or more conservative leaf development in the face of herbivory. As a consequence, the timing of full leaf expansion was delayed not only by later budburst (approximately two weeks) but also by a longer duration of leaf expansion (approximately two weeks) in evergreen than in Deciduous broad-leaved species, which would probably influence the productivity of newly emerging leaves in spring.
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relationships between the timing of budburst plant traits and distribution of 24 coexisting woody species in a warm temperate forest in japan
American Journal of Botany, 2017Co-Authors: Noriyuki OsadaAbstract:PREMISE OF THE STUDY: Timing of budburst (DBB) may be related to the functional traits and distributions of woody species in temperate regions. Although many previous studies have investigated DBB in a number of temperate species, it has seldom been linked to multiple plant trait relationships. METHODS: DBB and plant traits were investigated for 24 woody species for 2 years in a warm-temperate secondary forest in Japan. Particular attention was paid to differences in trait relationships between coexisting Deciduous and evergreen broad-leaved species. KEY RESULTS: DBB was correlated with plant traits in Deciduous but not evergreen broad-leaved species; DBB was later for Deciduous species with greater leaf mass, leaf area, vessel diameter, and leaf nitrogen content per unit mass. In addition, DBB was later for species with more northern distributions in Deciduous and evergreen species. CONCLUSIONS: Clear differences in the trait relationships between Deciduous and evergreen broad-leaved species might be caused by different selection pressures on DBB; selection is expected to be more severe in Deciduous species. Overall, the continuous variable of vessel diameter might be used as a simple and effective trait to predict DBB of Deciduous species regardless of wood anatomy; however, no such traits were detected as effective predictors of DBB in evergreen species at this study site. In addition, DBB was earlier for the species of more southern distributions, suggesting that such species benefit more from warming.
Yuzo Takagi - One of the best experts on this subject based on the ideXlab platform.
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Bovine dentine organic matrix down-regulates osteoclast activity
Journal of Bone and Mineral Metabolism, 2009Co-Authors: Wantida Sriarj, Kazuhiro Aoki, Keiichi Ohya, Yuzo Takagi, Hitoyata ShimokawaAbstract:Physiological root resorption is a phenomenon that normally takes place in Deciduous teeth; root resorption of permanent teeth occurs only under pathological conditions. The molecular mechanisms underlying these processes are still unclear. Our previous study showed that osteoclasts cultured on Deciduous dentine exhibited a higher degree of resorption and higher levels of cathepsin K and MMP-9 mRNA than osteoclasts cultured on permanent dentine. These results could be because of different susceptibilities to acid and the different organic matrices between Deciduous and permanent dentine. Thus, the purpose of this study was to investigate the effect of dentine extracts from bovine Deciduous and permanent dentine on osteoclast activity. Osteoclasts, obtained from mouse bone marrow cells co-cultured with an osteoblast-rich fraction in the presence of 1,25-(OH)_2-vitamin D3 and PGE2, were incubated with or without 0.6 M HCl extracts from bovine Deciduous or permanent dentine for 48 h. TRAP positive cell number, TRAP activity, the areas of resorption pits, and mRNA levels of TRAP, v-ATPase, calcitonin receptor, cathepsin K, and MMP-9 were examined. The results illustrated that TRAP activity, the resorbed area, and the mRNA levels of osteoclast marker genes seemed to be suppressed by both Deciduous and permanent dentine extracts. These findings indicate that some factors that suppress osteoclast activity are contained in both Deciduous and permanent dentine extracts. Although there was no significant difference in osteoclast activity between Deciduous and permanent dentine extracts, osteoclasts incubated with permanent dentine extracts tend to exhibit less resorption activity than those incubated with Deciduous dentine extracts. However, we could not clearly explain the causes of this.
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Bovine dentine organic matrix down-regulates osteoclast activity
Journal of Bone and Mineral Metabolism, 2009Co-Authors: Wantida Sriarj, Kazuhiro Aoki, Keiichi Ohya, Yuzo Takagi, Hitoyata ShimokawaAbstract:Physiological root resorption is a phenomenon that normally takes place in Deciduous teeth; root resorption of permanent teeth occurs only under pathological conditions. The molecular mechanisms underlying these processes are still unclear. Our previous study showed that osteoclasts cultured on Deciduous dentine exhibited a higher degree of resorption and higher levels of cathepsin K and MMP-9 mRNA than osteoclasts cultured on permanent dentine. These results could be because of different susceptibilities to acid and the different organic matrices between Deciduous and permanent dentine. Thus, the purpose of this study was to investigate the effect of dentine extracts from bovine Deciduous and permanent dentine on osteoclast activity. Osteoclasts, obtained from mouse bone marrow cells co-cultured with an osteoblast-rich fraction in the presence of 1,25-(OH)_2-vitamin D3 and PGE2, were incubated with or without 0.6 M HCl extracts from bovine Deciduous or permanent dentine for 48 h. TRAP positive cell number, TRAP activity, the areas of resorption pits, and mRNA levels of TRAP, v-ATPase, calcitonin receptor, cathepsin K, and MMP-9 were examined. The results illustrated that TRAP activity, the resorbed area, and the mRNA levels of osteoclast marker genes seemed to be suppressed by both Deciduous and permanent dentine extracts. These findings indicate that some factors that suppress osteoclast activity are contained in both Deciduous and permanent dentine extracts. Although there was no significant difference in osteoclast activity between Deciduous and permanent dentine extracts, osteoclasts incubated with permanent dentine extracts tend to exhibit less resorption activity than those incubated with Deciduous dentine extracts. However, we could not clearly explain the causes of this.
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Bovine Deciduous dentine is more susceptible to osteoclastic resorption than permanent dentine: results of quantitative analyses
Journal of Bone and Mineral Metabolism, 2006Co-Authors: Bobby John Varghese, Kazuhiro Aoki, Keiichi Ohya, Hitoyata Shimokawa, Yuzo TakagiAbstract:Many clinical reports suggest that Deciduous teeth exhibit a greater susceptibility to resorption than permanent ones. To examine the difference between Deciduous and permanent dentine in their susceptibility to osteoclastic resorption, osteoclast-like cells (OCLs) were cultured on Deciduous and permanent dentine slices. The number, area, depth, and volume of resorption pits were then measured, using image-analyzing systems. We measured the level of degraded collagen (cross-linked N-telopeptide of type I collagen; NTx) in culture medium using an enzyme-linked immunosorbent assay (ELISA). The levels of cathepsin K, matrix metallo proteinase (MMP)-9, and MMP-13 mRNAs in the cells attached to dentine were also analyzed by real-time reverse transcription polymerase chain reaction (RT-PCR). Deciduous dentine slices exhibited a significant (twofold) increase in resorbed area compared with the permanent slices. Three-dimensional analysis revealed that the volume of pits in Deciduous dentine differed significantly (fourfold) compared to that in the permanent dentine. The depth of pits also followed the same trend. However, there was no significant difference in the number of pits or osteoclasts on the dentine slices. The NTx level in Deciduous media was significantly more than that in permanent media. The mRNA levels also followed the same trend. These results suggest that Deciduous dentine is more susceptible to resorption than permanent dentine and signals from the substrate play an important role in physiological resorption.
Jhonathan O. Silva - One of the best experts on this subject based on the ideXlab platform.
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Leaf traits and herbivory on Deciduous and evergreen trees in a tropical dry forest
Basic and Applied Ecology, 2015Co-Authors: Jhonathan O. Silva, Mário M. Espírito-santo, Helena C. MoraisAbstract:Abstract Deciduous and evergreen trees coexist in tropical dry forests, but exhibit distinct leaf syndromes for resource-use efficiency and defenses against herbivores. Moreover, these functional groups may have contrasting patterns of temporal variation in leaf traits and herbivory along leaf ontogeny. We tested these predictions by comparing a set of leaf traits related to water stress and defense, and herbivory levels between young and mature leaves from evergreen leaf-exchanger and Deciduous species. We evaluated Deciduous and evergreen trees within the same habitat type: a tropical dry forest with 90–100% of leaf Deciduousness during the dry season. We sampled 10 individuals of three Deciduous and three evergreen species. Evergreen plants had greater leaf thickness and concentration of phenolics and tannins. On the other hand, Deciduous plants had higher leaf nitrogen content and specific leaf area. Deciduous plants lost twice as much leaf area by herbivory as evergreen plants (6.48% versus 3.20%), and leaf damage was positively related to both phenolic compounds and nitrogen content. Mature leaves from both phenological groups had higher levels of tannins and phenolic compounds, and lower levels of nitrogen and herbivory increment than young leaves. Our results suggest an adaptive convergence on leaf traits primarily related to water stress for different species within each phenological group. Some of these traits also play a role in leaf palatability, although the fitness consequences of the absolute difference in leaf damage (approximately 3%) between evergreen and Deciduous species remain unclear.
