期刊文献+
共找到9篇文章
< 1 >
每页显示 20 50 100
Bird guild loss and its determinants on subtropical land-bridge islands, China 被引量:1
1
作者 Zhifeng Ding Kenneth James Feeley +1 位作者 Huijian Hu Ping Ding 《Chinese Birds》 CSCD 2015年第2期99-106,共8页
Background: The guild concept is useful for understanding the community structure in a land-bridge island system,but most fragmentation studies have focused only on the importance of island area and isolation, other i... Background: The guild concept is useful for understanding the community structure in a land-bridge island system,but most fragmentation studies have focused only on the importance of island area and isolation, other island attributes such as perimeter-area ratio(PAR) were overlooked or understudied.Methods: We have adopted a guild approach to investigate the impacts of island attributes on bird guild richness on a set of 41 recently isolated land-bridge islands in the Thousand Island Lake(TIL), China.Results: We found insectivores had the largest number of species(34 species), fol owed by understory foraging guilds(28 species), omnivores(27 species) and canopy guilds(25 species). Furthermore, our data showed that migrants and residents responded equal y to island area, insectivores and understory guilds were sensitive to island area but omnivores and canopy guilds were not very sensitive. Most guild richness was determined by island area, except for omnivores and canopy guilds.Conclusions: Although PAR or habitat diversity found to be important for bird species richness, our results highlight the importance of island area in maintaining bird diversity in fragmented island systems. 展开更多
关键词 BIRD GUILDS ISLAND area Land-bridge islands PAR Thousand ISLAND Lake z values
下载PDF
Anti-proliferative effect of Annona extracts on breast cancer cells 被引量:2
2
作者 MARIA-LUISA VEISAGA MARIAM AHUMADA +5 位作者 STACY SORIANO LEONARDO ACUNA WEI ZHANG IVY LEUNG ROBERT BARNUM MANUEL A.BARBIERI 《BIOCELL》 SCIE 2023年第8期1835-1852,共18页
Backgorund:Fruits and seed extracts of Annona montana have significant cytotoxic potential in several cancer cells.This study evaluates the effect of A.montana leaves hexane extract on several signaling cascades and g... Backgorund:Fruits and seed extracts of Annona montana have significant cytotoxic potential in several cancer cells.This study evaluates the effect of A.montana leaves hexane extract on several signaling cascades and gene expression in metastatic breast cancer cells upon insulin-like growth factor-1(IGF-1)stimulation.Methods:MTT assay was performed to determine the proliferation of cancer cells.Propidium iodide staining and flow cytometry analysis of Annexin V binding was utilized to measure the progression of the cell cycle and the induction of apoptosis.Protein expression and phosphorylation were determined by western blotting analysis to examine the underlying cellular mechanism triggered upon treatment with A.montana leaves hexane extract.Results:A.montana leaves hexane(subfraction V)blocked the constitutive stimulation of the PI3K/mTOR signaling pathways.This inhibitory effect was associated with apoptosis induction as evidenced by the positivity with Annexin V and terminal deoxynucleotidyl transferase dUTP nick end labeling(TUNNEL)staining,activation of caspase-3,and cleavage of PPAR.It also limited the expression of various downstream genes that regulate proliferation,survival,metastasis,and angiogenesis(i.e.,cyclin D1,survivin,COX-2,and VEGF).It increased the expression of p53 and p21.Interestingly,we also observed that this extract blocked the activation of AKT and ERK without affecting the phosphorylation of the IGF-1 receptor and activation of Ras upon IGF-1 stimulation.Conclusion:Our study indicates that A.montana leaves(sub-fraction V)extract exhibits a selective anti-proliferative and proapoptotic effect on the metastatic MDA-MB-231 breast cancer cells through the involvement of PI3K/AKT/mTOR/S6K1 pathways. 展开更多
关键词 Annona montana Cancer cell lines Apoptosis ANTI-PROLIFERATIVE Cell cycle AKT MTOR
下载PDF
The Conservation Status and Conservation Strategy of Picea neoveitchii 被引量:3
3
作者 Zhang Deshun Kim Yongshik +1 位作者 Mike Maunder Li Xiufen 《Chinese Journal of Population,Resources and Environment》 北大核心 2006年第3期58-64,共7页
Picea neoveitchii is an endemic species in China. It had been listed as an endangered species in red data books. It scatters in several locations of south slope of the Qinling Mountain of China. Upon reviewing the rel... Picea neoveitchii is an endemic species in China. It had been listed as an endangered species in red data books. It scatters in several locations of south slope of the Qinling Mountain of China. Upon reviewing the related literature, discussing with leading scholars on gymnosperm, ecology and plant conservation, the field survey was carried out in four locations. There are eleven mature individuals and two seedlings surviving in its natural habitats. With the survey of quadrat method in four locations, related community index were calculated such as relative important value (RIV), species richness, similarity index, diversity index and evenness index etc. The community could be sorted and characterized as three groups based on the community parameters. The analysis of vegetation table elucidates that Picea neoveitchii is a dominant species with low grouping rate in most surveyed sites. The RAPD analysis shows target species has intraspecific genetic variability. The estimation of Shannon’s phenotypic diversity index (Ho) also explains the difference of genetic variations of different locations. Due to the lack of enough knowledge and professional guide of conservation biological perspective, Picea neoveitchii had been clear-cut for timber production. The extent of occurrence and area of occupancy declined rapidly from 1950s to 1990s. According to the Conservation Category guideline proposed by the World Conservation Union, the conservation status of Picea neoveitchii was reevaluated as Critically Endangered (CR) B2b C2a D. Upon research in areas of ecology, molecular biology, cluster analysis of environmental parameters, a practical conservation strategy is recommended in this research. 展开更多
关键词 CONSERVATION STATUS stratcgy Picea neoveiwhii
下载PDF
Anti-lipid droplets accumulation effect of Annona montana(mountain soursop)leaves extract on differentiation of preadipocytes 被引量:1
4
作者 IVY LEUNG MARIA-LUISA VEISAGA +3 位作者 MARGARITA ESPINAL WEI ZHANG ROBERT BARNUM MANUEL ALEJANDRO BARBIERI 《BIOCELL》 SCIE 2022年第3期567-578,共12页
The Annona genus is a member of Annonaceae,one of the largest families of plants across tropical and subtropical regions.This family has been used in several ethnomedicinal practices to treat a multitude of human dise... The Annona genus is a member of Annonaceae,one of the largest families of plants across tropical and subtropical regions.This family has been used in several ethnomedicinal practices to treat a multitude of human diseases.However,the molecular mechanism underlying its effect on the lipid droplet formation and on the expression of adipogenic markers of this plant remain to be investigated.In this study,we examined whether the extracts from the aerial part of Annona montana affect in vitro differentiation of preadipocytes.For our investigations,both mouse embryo fibroblast 3T3-L1 and normal human primary subcutaneous preadipocytes were incubated with Annona montana extracts(-and its subfractions-)and then analyzed on preadipocyte differentiation,lipid content,lipid droplet size and number,the expression of adipogenic-specific transcriptional factors,as well as cell survival.From our examinations,we found the Annona montana ethyl acetate extract to exhibit a potent inhibitory effect on adipogenesis,without affecting cell survival,in a dose-dependent manner.Such inhibitory effects included a significant decrease in the accumulation of lipid content by both a dramatic reduction of size and number of lipid droplets.This extract strongly attenuated the expression of PPARγand HMGB2.It also inhibited the expression of CEBPα,FAS,and Akt without influencing Erk1/2 activities.Our findings suggest that specifically,the Annona montana ethyl acetate extract has a prominent inhibitory effect in cellular pathways of adipocyte differentiation by modulating specific gene expression,which is known to perform a pivotal role during adipogenesis. 展开更多
关键词 Annona montana extracts Phytochemical analysis ADIPOGENESIS Lipid droplets Adipogenic-specific markers
下载PDF
A hypothesis for a novel role of RIN1-the modulation of telomerasefunction by the MAPK signaling pathway
5
作者 PATRIC HAMBLETON MANUEL ALEJANDRO BARBIERI 《BIOCELL》 SCIE 2020年第4期525-534,共10页
Cancerous cells display abnormalities in the signal transduction pathways responsible for responding to extracellular growth factors,or mitogens.Mutations that alter proteins involved in these types of pathways can le... Cancerous cells display abnormalities in the signal transduction pathways responsible for responding to extracellular growth factors,or mitogens.Mutations that alter proteins involved in these types of pathways can lead to inappropriate or unregulated cell growth,and therefore predispose the cell to become malignant.The critical role of the Ras/mitogen-activated protein kinase(MAPK)pathway in transducing growth signals to the interior of the cell and subsequently stimulating cell growth and proliferation is underscored by the fact that roughly one quarter of all human tumors contain mutant forms of Ras proteins.A particular focus on the signaling and membrane trafficking adaptor protein known as Ras interference 1(RIN1)will reveal how this protein can potentially play a significant role in the development of the cancerous phenotype in certain cell types.Of equal interest is the possible connection between the Ras/MAPK pathway,and subsequent expression and enzymatic activity of telomerase–a key enzyme known to be overexpressed in roughly 85%of all cancers.RIN1 is a 783 amino acid(84 kDa)cytosolic protein that is involved in key steps of growth factor receptormediated endocytosis and can potentially moderate signaling through the MAPK pathways.RIN1,with its unique ability to compete directly with Raf for activation by Ras,could potentially influence signaling through more than one of the MAPK pathways.If so,RIN1 may then be able to exert a precise and selective effect on the downstream signal(s)of a MAPK target such as telomerase. 展开更多
关键词 CANCER REGULATION PATHWAY TELOMERE
下载PDF
Embryo Rescue via Artificial Seed Technique and Long-Term Preservation of Zephyranthes
6
作者 Amir Ali Khoddamzadeh Bruce L. Dunn 《American Journal of Plant Sciences》 CAS 2022年第11期1347-1359,共13页
Zephyranthes is valued as a native ornamental landscaping plant and a traditional medicinal herb. Due to the low seed viability, this study was carried out to evaluate the potential of seed embryo rescue using the art... Zephyranthes is valued as a native ornamental landscaping plant and a traditional medicinal herb. Due to the low seed viability, this study was carried out to evaluate the potential of seed embryo rescue using the artificial seed technique and long-preservation in Z. atamasca and Z. grandiflora. Seed embryos were selected for encapsulation with different concentration of sodium alginate (3%, 4%, and 5%) and calcium chloride (either 25, 50, 75, and 100 mM) followed by no encapsulated embryos as a control. The greatest viability of encapsulated embryos was 95% in Z. grandiflora and 85% in Z. atamasca with the combination of 4% sodium alginate and 100 mM calcium chloride after two weeks at 5°C. The highest viability with A<sub>490nm</sub>0.12 and A<sub>490nm</sub>0.16 were achieved when embryos were cultured in pretreatment medium with 30 g/L sucrose in Z. grandiflora and Z. atamasca, respectively. The highest viability by TTC assay after cryopreservation was observed with 54% viability for Z. grandiflora and 48% viability with Z. atamasca, after 2 h of dehydration. Rain lilies embryos were successfully preserved functioned as artificial seed and cryopreservation using encapsulation-dehydration method has been established for both species that can be used for other flower species with some modifications. 展开更多
关键词 Rain Lily Synthetic Seed CRYOPRESERVATION ENCAPSULATION Ornamental Landscape Zephyranthes atamasc Zephyranthes grandiflora
下载PDF
In-Vitro Micropropagation and Acclimatization of an Endangered Native Orchid Using Organic Supplements
7
作者 Douglas De Stefano Bárbara Nogueira Souza Costa +2 位作者 Jason Downing Esmaeil Fallahi Amir Ali Khoddamzadeh 《American Journal of Plant Sciences》 2022年第3期380-393,共14页
In-vitro propagation is a technique that provides a vital solution for the conservation of endangered orchid species. The media used in tissue culture can be modified through the addition of inexpensive organic materi... In-vitro propagation is a technique that provides a vital solution for the conservation of endangered orchid species. The media used in tissue culture can be modified through the addition of inexpensive organic materials as an alternative to expensive synthetic additives. Some organic sources, such as coconut water and fruit juice, contain significant amounts of vitamins, amino acids, and organic compounds which can act as growth regulators, making these organic sources excellent additives for in-vitro cultivation. The aim of this study was to develop a protocol for in-vitro micropropagation and acclimatization of Epidendrum nocturnum using organic supplements in the growth media and various substrates at the acclimatization stage. Banana powder, coconut water, and potato dextrose were added to a basal seed sowing media and evaluated for seed germination percentage and plantlet growth. In addition, various substrates such as coconut coir, horticultural charcoal, sphagnum moss, and wood bark were evaluated for height, number of leaves, and number of shoots in the acclimatization portion of this study. The culture medium with coconut water showed a greater germination percentage (71.00% and 76.75%) compared with the control (37.50% and 45.50%) at 60 and 90 days after seed sowing, respectively. Media with organic supplements showed greater values of plant length and number of roots compared with the control. The combination of coconut coir and horticultural charcoal was shown to be more efficient than the combination of sphagnum moss, horticultural charcoal, and wood bark, as results showed greater values of plant height and number of leaves at 30, 90, and 120 days after transplantation in acclimatization of E. nocturnum. 展开更多
关键词 Tissue Culture Native Orchid Plant Growth Hormones Climate Change Epidendrum nocturnum
下载PDF
Comprehensive phylogenetic analyses of Orchidaceae using nuclear genes and evolutionary insights into epiphytism 被引量:6
8
作者 Guojin Zhang Yi Hu +7 位作者 Ming-Zhong Huang Wei-Chang Huang Ding-Kun Liu Diyang Zhang Haihua Hu Jason L.Downing Zhong-Jian Liu Hong Ma 《Journal of Integrative Plant Biology》 SCIE CAS CSCD 2023年第5期1204-1225,共22页
Orchidaceae(with>28,000 orchid species)are one of the two largest plant families,with economically and ecologically important species,and occupy global and diverse niches with primary distribution in rainforests.Am... Orchidaceae(with>28,000 orchid species)are one of the two largest plant families,with economically and ecologically important species,and occupy global and diverse niches with primary distribution in rainforests.Among orchids,70%grow on other plants as epiphytes;epiphytes contribute up to~50%of the plant diversity in rainforests and provide food and shelter for diverse animals and microbes,thereby contributing to the health of these ecosystems.Orchids account for over two-thirds of vascular epiphytes and provide an excellent model for studying evolution of epiphytism.Extensive phylogenetic studies of Orchidaceae and subgroups have;been crucial for understanding relationships among many orchid lineages,although some uncertainties remain.For example,in the largest subfamily Epidendroideae with nearly all epiphytic orchids,relationships among some tribes and many subtribes are still controversial,hampering evolutionary analyses of epiphytism.Here we obtained 1,450 low-copy nuclear genes from 610 orchid species,including 431 with newly generated transcriptomes,and used them for the reconstruction of robust Orchidaceae phylogenetic trees with highly supported placements of tribes and subtribes.We also provide generally wellsupported phylogenetic placements of 131 genera and 437 species that were not sampled by previous plastid and nuclear phylogenomic studies.Molecular clock analyses estimated the Orchidaceae origin at~132 million years ago(Ma)and divergences of most subtribes from 52 to 29 Ma.Character reconstruction supports at least 14 parallel origins of epiphytism;one such origin was placed at the most recent common ancestor of~95%of epiphytic orchids and linked to modern rainforests.Ten occurrences of rapid increase in the diversification rate were detected within Epidendroideae near and after the K-Pg boundary,contributing to~80%of the Orchidaceae diversity.This study provides a robust and the largest family-wide Orchidaceae nuclear phylogenetic tree thus far and new insights into the evolution of epiphytism in vascular plants. 展开更多
关键词 convergence EPIPHYTES evolution ORCHIDS parallel rainforest PHYLOGENOMICS TRANSCRIPTOME
原文传递
以产业化促进物种保护和可持续利用的新模式:以兰花为例 被引量:14
9
作者 刘虹 罗毅波 刘仲健 《生物多样性》 CAS CSCD 北大核心 2013年第1期132-135,共4页
如何平衡野生植物的保护与开发的关系已成为亟需解决的社会问题。本文以药用兰科植物铁皮石斛(Dendrobium catenatum)为例,提出在发达地区建立生产和深加工基地,建立公司+林场+农户参与栽培的组织体系,利用铁皮石斛特性促进岩溶和丹霞... 如何平衡野生植物的保护与开发的关系已成为亟需解决的社会问题。本文以药用兰科植物铁皮石斛(Dendrobium catenatum)为例,提出在发达地区建立生产和深加工基地,建立公司+林场+农户参与栽培的组织体系,利用铁皮石斛特性促进岩溶和丹霞地貌生态保护,即在岩溶和丹霞贫困地区自然环境下进行种群野外回归增加资源存量,并实施可持续性收获,增加栖息地的保护动力。这种经济利益引导的保护模式与西方发达国家的濒危物种保护模式有别,但更适合中国国情,可在实现经济效益的同时促进兰科物种恢复和保护。 展开更多
关键词 兰科植物 DENDROBIUM catenatum 保护 产业开发 模式
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部