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141.
Species diversity of the genus Osmundea (Ceramiales,Rhodophyta) in the Macaronesian region 下载免费PDF全文
María Machín‐Sánchez Florence Rousseau Line Le Gall Valéria Cassano Ana I. Neto Abel Sentíes Mutue T. Fujii María Candelaria Gil‐Rodríguez 《Journal of phycology》2016,52(4):664-681
Species diversity within the genus Osmundea in the Macaronesian region was explored by conducting a comprehensive sampling in the Azores, the Canary, and the Madeira archipelagos. Toward identification, all specimens were first observed alive to verify the absence of corps en cerise, a diagnostic character for the genus and morphometric data were measured (thallus length and width, first‐order branches length and width, branchlets length and width, cortical cell length and width in surface view, cortical cell length and width in transverse section). Specimens were sequenced for COI‐5P (39 specimens) and three species delimitation methods (Generalized Mixed Yule Coalescent, Automatic Barcode Gap Discovery method, and Poisson Tree Processes) were used to assess the threshold between infra‐ and interspecific relationships. Subsequently, one or several sequences of plastid‐encoded large subunit of RuBisCO (21 specimens) per delimited species were generated to assess the phylogenetic relationships among Macaronesian Osmundea. Moreover, for each delineated species, vegetative and reproductive anatomy was thoroughly documented and, when possible, specimens were either assigned to existing taxa or described as novel species. This integrative approach has provided data for (i) the presence of O. oederi, O. pinnatifida, and O. truncata in Macaronesia; (ii) the proposal of two novel species, O. prudhommevanreinei sp. nov. and O. silvae sp. nov.; and (iii) evidence of an additional species referred as “Osmundea sp.1,” which is a sister taxon of O. hybrida. 相似文献
142.
Recruitment is a complex process consisting of sequential stages affected by biotic interactions and abiotic factors. Assessment of these sequential stages and corresponding subprocesses may be useful in identifying the most critical stages. Accordingly, to assess the factors that may determine the altitudinal range limits of the high mountain Mediterranean plant Silene ciliata, a set of demographic stages, from flower production to establishment of 2‐yr‐old plants, and their influence on recruitment probability were examined using a step‐by‐step approach. We integrated florivory, pollination and pre‐dispersal seed predation as pre‐dispersal factors, and seedling emergence and survival as post‐dispersal determinants of recruitment. Three populations were monitored at the southernmost margin of the species along its local altitudinal range. Previous studies suggest that seediness is strongly limited by summer drought especially at the lower boundary of the species, a situation that may worsen under current global warming. Our results showed that recruitment was mainly limited by low seed production in the pre‐dispersal stage and low seedling emergence and survival in the post‐dispersal stage, probably due to environmental harshness in summer. By contrast, biotic factors responsible for propagule loss, such as flower and fruit predation, had a minor effect on the probability of plant recruitment. Although the relative importance of transition probabilities was similar among populations along the altitudinal range, comparatively lower flower production significantly reduced the number of recruited plants at the lowest altitude population. This demographic bottleneck, together with increased competition with other species favoured by climate warming, might collapse population growth and limit persistence at the lower altitudinal range of the species, raising its low local altitudinal edge. 相似文献
143.
双尾蚜属Diuraphis Aizenberg全世界记录13种,主要分布在古北界和新北界。根据种类丰富度和特有种成分,欧亚大陆的欧洲和中亚为该属蚜虫的现代第一分布中心,北美为第二分布中心。本文提供了该属所有13个种的分种检索表。双尾蚜属蚜虫在中国共有7种,主要分布在蒙新区。它们是:麦双尾蚜Diuraphis noxia (Mordvilko), 害冰麦双尾蚜D. nociva Zhang et Liang,冰草麦蚜D. (Holcaphis) agropyronophaga Zhang, 披碱草蚜D. (Holcaphis) elymophila Zhang, 西方麦蚜D. (Holcaphis) frequens (Walker), 雀麦蚜D. (Holcaphis) bromicola Hille Ris Lambers和绒毛草蚜D. (Holcaphis) holci (Hille Ris Lambers)。对中国种类进行了简要描述。 相似文献
144.
Xiong XH Han S Wang JH Jiang ZH Chen W Jia N Wei HL Cheng H Yang YX Zhu B You S He JY Hou W Chen MX Yu CJ Jiao YH Zhang WC 《Journal of bacteriology》2011,193(1):315-316
Ketogulonicigenium vulgare is characterized by the efficient production of 2KGA from L-sorbose. Ketogulonicigenium vulgare Y25 is known as a 2-keto-L-gulonic acid-producing strain in the vitamin C industry. Here we report the finished, annotated genome sequence of Ketogulonicigenium vulgare Y25. 相似文献
145.
R.R.M. Zautsen F. Maugeri‐Filho C.E. Vaz‐Rossell A.J.J. Straathof L.A.M. van der Wielen J.A.M. de Bont 《Biotechnology and bioengineering》2009,102(5):1354-1360
Several compounds that are formed or released during hydrolysis of lignocellulosic biomass inhibit the fermentation of the hydrolysate. The use of a liquid extractive agent is suggested as a method for removal of these fermentation inhibitors. The method can be applied before or during the fermentation. For a series of alkanes and alcohols, partition coefficients were measured at low concentrations of the inhibiting compounds furfural, hydroxymethyl furfural, vanillin, syringaldehyde, coniferyl aldehyde, acetic acid, as well as for ethanol as the fermentation product. Carbon dioxide production was measured during fermentation in the presence of each organic solvent to indicate its biocompatibility. The feasibility of extractive fermentation of hydrolysate was investigated by ethanolic glucose fermentation in synthetic medium containing several concentrations of furfural and vanillin and in the presence of decanol, oleyl alcohol and oleic acid. Volumetric ethanol productivity with 6 g/L vanillin in the medium increased twofold with 30% volume oleyl alcohol. Decanol showed interesting extractive properties for most fermentation inhibiting compounds, but it is not suitable for in situ application due to its poor biocompatibility. Biotechnol. Bioeng. 2009;102: 1354–1360. © 2008 Wiley Periodicals, Inc. 相似文献
146.
Li-bo Cheng Lei Cheng Hui-e Bi Zhi-qing Zhang Jin Yao Xiao-zhong Zhou Qin Jiang 《Biochemical and biophysical research communications》2014
Patients with age related macular degeneration (AMD) will develop vision loss in the center of the visual field. Reactive oxygen species (ROS)-mediated retinal pigment epithelium (RPE) cell apoptosis is an important contributor of AMD. In this study, we explored the pro-survival effect of α-melanocyte stimulating hormone (α-MSH) on oxidative stressed RPE cells. We found that α-MSH receptor melanocortin 1 receptor (MC1R) was functionally expressed in primary and transformed RPE cells. RPE cells were response to α-MSH stimulation. α-MSH activated Akt/mammalian target of rapamycin (mTOR) and Erk1/2 signalings in RPE cells, which were inhibited by MC1R siRNA knockdown. α-MSH protected RPE cells from hydrogen peroxide (H2O2)-induced apoptosis, an effect that was almost abolished when MC1R was depleted by siRNA. α-MSH-mediated S6K1 activation and pro-survival effect against H2O2 was inhibited by Akt inhibitors (perifosine, MK-2206 and LY294002). Further, mTOR inhibition by rapamycin, or by mTOR siRNA knockdown, diminished α-MSH’s pro-survival effect in RPE cells. Thus, Akt and its downstream mTOR signaling mediates α-MSH-induced survival in RPE cells. In summary, we have identified a new α-MSH–MC1R physiologic pathway that reduces H2O2-induced RPE cell damage, and might minimize the risk of developing AMD. 相似文献
147.
148.
Toshihiko Sudo Xiaoxian Zhao Yoko Wakamatsu Miki Shibahara Nobuhiko Nomura Tadaatsu Nakahara Akemi Suzuki Yoshiro Kobayashi Chunyuan Jin Takehide Murata Kazunari K. Yokoyama 《Cytotechnology》2000,33(1-3):259-264
Four analogs of succinoyl trehalose lipid-3 (STL-3)with saturated even-number or odd-number carbonchains, and unsaturated or halogenated fatty acidswere examined for their ability to inhibit the growthand induce the differentiation of HL-60 humanpromyelocytic leukemia cells. The optimalconcentration of STL-3 at which such activities wererecognized was closed to the critical micelleconcentration of STL-3. Analog of STL-3 witheven-number or odd-number carbon chain and unsaturatedfatty acids strongly inhibited growth and induced thedifferentiation of HL-60 cells, as evaluated in termsof nitroblue tetrazilium-reducing activity and theappearance of the CD36 antigen. An analog of STL-3with halogenated fatty acids significantly inhibitedproliferation but only induced the differentiation ofHL-60 cells. Our results indicate that the effects ofSTL-3 and its analogs on HL-60 cells depend on thestructure of the hydrophobic moiety of STL-3.These authors contributed equally to this work 相似文献
149.
Daniel Paredes Jay A. Rosenheim Rebecca Chaplin‐Kramer Silvia Winter Daniel S. Karp 《Ecology letters》2021,24(1):73-83
Diversifying agricultural landscapes may mitigate biodiversity declines and improve pest management. Yet landscapes are rarely managed to suppress pests, in part because researchers seldom measure key variables related to pest outbreaks and insecticides that drive management decisions. We used a 13‐year government database to analyse landscape effects on European grapevine moth (Lobesia botrana) outbreaks and insecticides across c. 400 Spanish vineyards. At harvest, we found pest outbreaks increased four‐fold in simplified, vineyard‐dominated landscapes compared to complex landscapes in which vineyards are surrounded by semi‐natural habitats. Similarly, insecticide applications doubled in vineyard‐dominated landscapes but declined in vineyards surrounded by shrubland. Importantly, pest population stochasticity would have masked these large effects if numbers of study sites and years were reduced to typical levels in landscape pest‐control studies. Our results suggest increasing landscape complexity may mitigate pest populations and insecticide applications. Habitat conservation represents an economically and environmentally sound approach for achieving sustainable grape production. 相似文献
150.
Sophie Lavoine‐Hanneguelle Christine Périchet Nicolas Schnaebele Marina Humbert 《化学与生物多样性》2014,11(11):1798-1820
For over the past 20 years, a remarkable development in the study and search of natural products has been observed. This is linked to a new market trend towards ecology and also due to new regulations. This could be a rupture, but also a real booster for creativity. Usually, in the flavor and fragrance field, creativity was boosted by the arrival of new synthetic molecules. Naturals remained the traditional, century‐old products, protected by secrecy and specific know‐how from each company. Regulatory restrictions or eco‐friendly certification constraints like hexane‐free processes triggered an important brainstorming in the industry. As a result, we developed new eco‐friendly processes including supercritical CO2 extraction, allowing fresh plants to be used to obtain industrial flower extracts (Jasmine Grandiflorum, Jasmine Sambac, Orange blossom). These extracts are analyzed by GC, GC/MS, GC? O, and HPTLC techniques. New or unusual raw materials can also be explored, but the resulting extracts have to be tested for safety reasons. Some examples are described. 相似文献