The species diversity at the regeneration stage, inflenced by different water levels, is important for community composition in the later growing season.Regeneration diversity of Carex lasiocarpa community under diffe...The species diversity at the regeneration stage, inflenced by different water levels, is important for community composition in the later growing season.Regeneration diversity of Carex lasiocarpa community under different water levels was studied at two stages, recruitment and adult, in the Sanjiang Plain, Heilongjiang Province, China.The results showed that, at the two growing stages, important value of C.lasiocarpa population and species richness of the community decreased with the increasing water level, while the Simpson and Shannon-Wiener diversity indexes and Pielou evenness index increased.Under different water levels, community diversities were higher at the recruitment stage, while population important values of C.lasiocarpa were higher at the adult stage.Indexes in vegetation evaluation must be chosen prudentially for successful restoration and effective management of wetlands, and especially for wetland restoration, the optimal time should be selected according to the restoration objectives and costs.展开更多
More than 80%of all cases of deafness are related to the death or degeneration of cochlear hair cells and the associated spiral ganglion neurons,and a lack of regeneration of these cells leads to permanent hearing los...More than 80%of all cases of deafness are related to the death or degeneration of cochlear hair cells and the associated spiral ganglion neurons,and a lack of regeneration of these cells leads to permanent hearing loss.Therefore,the regeneration of lost hair cells is an important goal for the treatment of deafness.Atoh1 is a basic helix-loop-helix(bHLH)transcription factor that is critical in both the development and regeneration of cochlear hair cells.Atoh1 is transcriptionally regulated by several signaling pathways,including Notch and Wnt signalings.At the post-translational level,it is regulated through the ubiquitin-proteasome pathway.In vitro and in vivo studies have revealed that manipulation of these signaling pathways not only controls development,but also leads to the regeneration of cochlear hair cells after damage.Recent progress toward understanding the signaling networks involved in hair cell development and regeneration has led to the development of new strategies to replace lost hair cells.This review focuses on our current understanding of the signaling pathways that regulate Atoh1 in the cochlea.展开更多
Clear-cutting, a management practice applied to many beech forests in the North of Spain, modifies microclimate and, consequently, the composition of the understory plant community in the disturbed areas. The objectiv...Clear-cutting, a management practice applied to many beech forests in the North of Spain, modifies microclimate and, consequently, the composition of the understory plant community in the disturbed areas. The objectives of this study were to assess if changes in the understory vegetation caused by altered light microclimate after clear-cutting affect the infectivity of arbuscular mycorrhizal fungi （AMF） on herbaceous plant species in beech （Fagus sylvatica L.） forests naturally regenerating from clear-cutting and to test if the use of bioassays for studying the infectivity of native AMF could provide useful information to improve the management of clear-cut areas. Three nearby beech forests in northwest Navarra, Spain, a region in the northwest part of the Pyrenees, were selected： an unmanaged forest, a forest clear-cut in 1996, and another forest clear-cut in 2001. High stem density in the forest clear-cut in 1996 （44 000 trees ha-1） attenuated photosynthetic active radiation （PAR） and impaired the growth of herbaceous species within the ecosystem. The percentage of AMF colonization of plants in bioassays performed on soil samples collected from the forest clear-cut in 1996 was always lower than 10S. In the forest clear-cut in 2001, where soil was covered by perennial grasses, PAR was high and the infectivity of native AMF achieved minimum values in spring and autumn and a maximum value in summer. In contrast, the infectivity of native AMF in the unmanaged forest remained similar across the seasons. Our results demonstrated that changes in the composition of understory vegetation within beech forests strongly affected the infectivity of native AMF in clear-cut areas and suggested that the assessment of the infectivity of native AMF through bioassays could provide helpful information for planning either the removal of overstory when the tree density is so high that it impairs the correct development of herbaceous species or the plantation of new seedlings when high light intensity negatively affects the establishment of shade species.展开更多
基金Under the auspices of the National Basic Research Program of China (No. 2009CB421103)Northeast Revitalization Program,Chinese Academy of Sciences (No. DBZX-2-024)
文摘The species diversity at the regeneration stage, inflenced by different water levels, is important for community composition in the later growing season.Regeneration diversity of Carex lasiocarpa community under different water levels was studied at two stages, recruitment and adult, in the Sanjiang Plain, Heilongjiang Province, China.The results showed that, at the two growing stages, important value of C.lasiocarpa population and species richness of the community decreased with the increasing water level, while the Simpson and Shannon-Wiener diversity indexes and Pielou evenness index increased.Under different water levels, community diversities were higher at the recruitment stage, while population important values of C.lasiocarpa were higher at the adult stage.Indexes in vegetation evaluation must be chosen prudentially for successful restoration and effective management of wetlands, and especially for wetland restoration, the optimal time should be selected according to the restoration objectives and costs.
文摘More than 80%of all cases of deafness are related to the death or degeneration of cochlear hair cells and the associated spiral ganglion neurons,and a lack of regeneration of these cells leads to permanent hearing loss.Therefore,the regeneration of lost hair cells is an important goal for the treatment of deafness.Atoh1 is a basic helix-loop-helix(bHLH)transcription factor that is critical in both the development and regeneration of cochlear hair cells.Atoh1 is transcriptionally regulated by several signaling pathways,including Notch and Wnt signalings.At the post-translational level,it is regulated through the ubiquitin-proteasome pathway.In vitro and in vivo studies have revealed that manipulation of these signaling pathways not only controls development,but also leads to the regeneration of cochlear hair cells after damage.Recent progress toward understanding the signaling networks involved in hair cell development and regeneration has led to the development of new strategies to replace lost hair cells.This review focuses on our current understanding of the signaling pathways that regulate Atoh1 in the cochlea.
基金Supported by the University Foundation of Navarra,Spainthe Caja Navarra,Spainand the University of Navarra,Inc.,Spain.
文摘Clear-cutting, a management practice applied to many beech forests in the North of Spain, modifies microclimate and, consequently, the composition of the understory plant community in the disturbed areas. The objectives of this study were to assess if changes in the understory vegetation caused by altered light microclimate after clear-cutting affect the infectivity of arbuscular mycorrhizal fungi （AMF） on herbaceous plant species in beech （Fagus sylvatica L.） forests naturally regenerating from clear-cutting and to test if the use of bioassays for studying the infectivity of native AMF could provide useful information to improve the management of clear-cut areas. Three nearby beech forests in northwest Navarra, Spain, a region in the northwest part of the Pyrenees, were selected： an unmanaged forest, a forest clear-cut in 1996, and another forest clear-cut in 2001. High stem density in the forest clear-cut in 1996 （44 000 trees ha-1） attenuated photosynthetic active radiation （PAR） and impaired the growth of herbaceous species within the ecosystem. The percentage of AMF colonization of plants in bioassays performed on soil samples collected from the forest clear-cut in 1996 was always lower than 10S. In the forest clear-cut in 2001, where soil was covered by perennial grasses, PAR was high and the infectivity of native AMF achieved minimum values in spring and autumn and a maximum value in summer. In contrast, the infectivity of native AMF in the unmanaged forest remained similar across the seasons. Our results demonstrated that changes in the composition of understory vegetation within beech forests strongly affected the infectivity of native AMF in clear-cut areas and suggested that the assessment of the infectivity of native AMF through bioassays could provide helpful information for planning either the removal of overstory when the tree density is so high that it impairs the correct development of herbaceous species or the plantation of new seedlings when high light intensity negatively affects the establishment of shade species.
