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71.
Alexander Thiel Nils Tippkötter Kirstin Suck Ulrich Sohling Friedrich Ruf Roland Ulber 《Engineering in Life Science》2013,13(3):239-246
Commercial materials with polyvinylpolypyrrolidone and polymeric amberlites (XAD7HP, XAD16) are commonly used for the adsorptive downstream processing of polyphenols from renewable resources. In this study, beta‐zeolite‐based adsorbent systems were examined, and their properties were compared to organic resins. Batch adsorption experiments were conducted with synthetic solutions of major polyphenols. Adsorption isotherms and desorption characteristics of individual adsorbent were determined based on these results. Maximum adsorption capacities were calculated using the Langmuir model. For example, the zeolites had capacities up to 203.2 mg/g for ferulic acid. To extend these results to a complex system, additional experiments were performed on rapeseed meal and wheat seed extracts as representative renewable resources. HPLC analysis showed that with 7.5% w/v, which is regarded as the optimum amount of zeolites, zeolites A and B could bind 100% of the major polyphenols as well as release polyphenols at high yields. Additionally, regeneration experiments were performed with isopropyl alcohol at 99°C to evaluate how zeolites regenerate under mild conditions. The results showed only a negligible loss of adsorption capacity and no loss of desorption capacity. In summary, it was concluded that beta‐zeolites were promising adsorbents for developing new processes to isolate polyphenols from renewable resources. 相似文献
72.
Tadeo Ramirez-Parada Domingo Cabrera Zoe Diaz-Martin Luke Browne Jordan Karubian 《Biotropica》2020,52(5):845-856
Many tropical plant species show wide intra-population variation in reproductive timing, resulting in the protracted presence of flowering and fruiting individuals. Various eco-evolutionary drivers have been proposed as ultimate causes for asynchronous phenology, yet little is known about the proximate factors that control reproductive onset among individuals or that influence the proportion of trees producing new inflorescences within a population. We employed a nine-year phenological record from 178 individuals of the hyperdominant, asynchronously flowering canopy palm, Oenocarpus bataua (Arecaceae)¸ to assess whether resource-related variables influence individual- and population-level flowering phenology. Among individuals, access to sunlight increased rates of inflorescence production, while the presence of resource sinks related to current investment in reproduction—developing infructescences—reduced the probability of producing new inflorescences. At the population level, climate anomalies induced by El Niño Southern Oscillation (ENSO) affected the proportion of the population producing inflorescences through time. Moreover, the effects of ENSO anomalies on flowering patterns depended on the prevalence of developing infructescences in the population, with stronger effects in periods of low developing-infructescence frequency. Taken together, these results suggest that resource-related variables can drive phenological differences among individuals and mediate population-level responses to larger-scale variables, such as climate anomalies. Consequently, a greater focus on the role of resource levels as endogenous cues for reproduction might help explain the frequent aseasonal phenological patterns observed among tropical plants, particularly those showing high intra-population asynchrony. 相似文献
73.
Background and Aims
Preservation of cultivar purity creates a particular challenge for plants that are self-incompatible, require insects for cross-pollination, and have easily germinating seeds and vigorously spreading rhizomes. As the fields must be planted with mixed populations, and a balance must be maintained between the cultivars to achieve effective pollination, methods for field monitoring of the relative density of different cultivars must be practical. Furthermore, a DNA-based method is needed for cultivar verification in the collections and outside of the growing season. The aim of this study was to develop both types of methods for Rubus arcticus (arctic bramble).Methods
Morphological parameters were measured from six cultivars grown on three farms. Observations from the flowers and fruits included: petal and sepal number, flower diameter, arrangement of petals, size of calyx in relation to corolla, fruit weight, yield and soluble sugars. Observations from the leaves included: width and height of middle leaflet, shape of the base of terminal leaflet, shape of terminal leaflet, leaf margin serration and fingertip touch. The applicability of simple sequence repeat (SSR) or microsatellite DNA markers developed for red raspberry was tested on eight arctic bramble cultivars.Key Results and Conclusions
Morphological and molecular identification methods were developed for R. arcticus. The best morphological characteristics were the length-to-width ratio of the middle leaflet and leaf margin serration. A particular characteristic, fingertip touch, was shown by electron microscopy to be related to the density and quality of the leaf hairs. Red raspberry SSR marker no. 126 proved to be applicable for differentiation of the eight arctic bramble cultivars tested. These identification methods are critical to secure the maintenance and management of R. arcticus. However, the challenges faced and approaches taken are equally applicable to other species with similar biology. 相似文献74.
This paper presents the advances made over the last decade in cryopreservation of economically important vegetatively propagated fruit trees. Cryopreservation protocols have been established using both dormant buds sampled on field-grown plants and shoot tips sampled on in vitro plantlets. In the case of dormant buds, scions are partially dehydrated by storage at − 5 °C, and then cooled slowly to − 30 °C using low cooling rates (c.a. 1 °C/h) before immersion in liquid nitrogen. After slow rewarming and rehydration of samples, regrowth takes place either through grafting of buds on rootstocks or excision of apices and inoculation in vitro. In the case of shoot tips of in vitro plantlets, the cryopreservation techniques employed are the following: controlled rate cooling procedures involving slow prefreezing followed by immersion in liquid nitrogen or vitrification-based procedures including encapsulation–dehydration, vitrification, encapsulation–vitrification and droplet-vitrification. The current status of cryopreservation for a series of fruit tree species including Actinidia, Diospyros, Malus, Olea, Prunus, Pyrus and Vitis is presented. Routine application of cryopreservation for long-term germplasm storage in genebanks is currently limited to apple and pear, for which large cryopreserved collections have been established at NCGRP, Fort Collins (USA), using dormant buds and in vitro shoot tips, respectively. However, there are a growing number of examples of pilot scale testing experiments under way for different species in various countries. Progress in the further development and application of cryopreservation techniques will be made through a better understanding of the mechanisms involved in the induction of tolerance to dehydration and cryopreservation in frozen explants. 相似文献
75.
The importance of coastal resources in the late Upper Paleolithic of western Europe has been reevaluated in recent years thanks to a growing body of new archeological evidence, including the identification of more than 50 implements made of whale bone in the Magdalenian level of the Isturitz cave (western Pyrenees). In the present study, the assemblages of osseous industry from 23 Magdalenian sites and site clusters in the northern Pyrenees were investigated, systematically searching for whale-bone implements. The objective of this research was to determine if, and how, tools and weapons of coastal origin were circulated beyond Isturitz into the inland, and if similar implements existed on the eastern, Mediterranean side of the Pyrenees. A total of 109 whale-bone artifacts, mostly projectile heads of large dimensions, were identified in 11 sites. Their geographic distribution shows that whale bone in the Pyrenean Magdalenian is exclusively of Atlantic origin, and that objects made of this material were transported along the Pyrenees up to the central part of the range at travel distances of at least 350 km from the seashore. This phenomenon seems to have taken place during the second half of the Middle Magdalenian and the first half of the Late Magdalenian, ca. 17,500–15,000 cal BP (calibrated years before present). The existence of a durable, extended coastal-inland interaction network including the circulation of regular tools is thus demonstrated. Additionally, differences between the whale-bone projectile heads of the Middle Magdalenian and those of the Late Magdalenian document an evolutionary process in the design of hunting weapons. 相似文献
76.
77.
This article discusses the allocation problem in international fisheries management, which is critical to effective resource management. A number of cases where allocation problems exist are reviewed and trends identified. It is concluded that power relationships between the states involved are an important determinant of allocation outcomes. While this may seem a frustrating conclusion, it nevertheless reflects the realities of international cooperation. 相似文献
78.
Fred R. Myers 《Ethnos》2013,78(2):263-273
What happens to the relations involved in ownership when faced with new claims and challenges? This article looks at three examples of the way in which Mongolians are managing claims to resources and responding to new regimes of ownership. In each case, recourse to models of ownership based on masters and custodians are marshalled and extended to suit new contexts. I suggest that these should not be viewed as modern responses to the inequalities of current economic and social life [cf. Comaroff and Comaroff. 1999, May. Occult Economies and the Violence of Abstraction: Notes from the South African Postcolony. American Ethnologist, 26(2): 279–303], nor should they be viewed as a historical remnant from some previous social life. Rather, and here I follow Tsing [2004. Friction: An Ethnography of Global Connection. Princeton: Princeton University Press; 2015a. The Mushroom at the End of the World: On the Possibility of Life in Capitalist Ruins. Princeton: Princeton University Press; 2015b. Salvage Accumulation, or the Structural Effects of Capitalist Generativity. In Theorizing the Contemporary, Cultural Anthropology Website, March 30, 2015. https://culanth.org/fieldsights/656-salvage-accumulation-or-the-structural-effects-of-capitalist-generativity], they may be viewed as an outcome of an innovative ‘friction’, or ‘salvage economy’, between global and local realities that gives rise to what Gibson-Graham [2006. A Postcapitalist Politics. Minnesota: Minnesota University Press] argues is a heterogeneous capitalist landscape, here manifested in Mongolia’s dramatically rising and falling mineral economy. 相似文献
79.
Shizhong Xu 《Genetics》2013,195(3):1103-1115
The correct models for quantitative trait locus mapping are the ones that simultaneously include all significant genetic effects. Such models are difficult to handle for high marker density. Improving statistical methods for high-dimensional data appears to have reached a plateau. Alternative approaches must be explored to break the bottleneck of genomic data analysis. The fact that all markers are located in a few chromosomes of the genome leads to linkage disequilibrium among markers. This suggests that dimension reduction can also be achieved through data manipulation. High-density markers are used to infer recombination breakpoints, which then facilitate construction of bins. The bins are treated as new synthetic markers. The number of bins is always a manageable number, on the order of a few thousand. Using the bin data of a recombinant inbred line population of rice, we demonstrated genetic mapping, using all bins in a simultaneous manner. To facilitate genomic selection, we developed a method to create user-defined (artificial) bins, in which breakpoints are allowed within bins. Using eight traits of rice, we showed that artificial bin data analysis often improves the predictability compared with natural bin data analysis. Of the eight traits, three showed high predictability, two had intermediate predictability, and two had low predictability. A binary trait with a known gene had predictability near perfect. Genetic mapping using bin data points to a new direction of genomic data analysis. 相似文献
80.
广西柿种质资源果实性状多样性分析与模糊综合评价 总被引:1,自引:0,他引:1
为进一步揭示广西柿种质资源信息,运用多样性分析和模糊综合评价法对不同生态气候区的柿种质资源果实性状进行研究和评价。结果表明:不同柿种质的果实性状存在丰富的多样性。86份柿种质的模糊综合评价指数FCI值在1.849~3.947之间,平均2.835。根据FCI取值范围将所调查的柿种质分成5个等级,FCI值最高的第5级种质数量最少,占所调查种质的3.49%;FCI值最低的第1级种质数量最多,占所调查种质的48.84%。月柿、牛心柿、大方柿、京柿、鸡心柿、小方柿和火柿等柿品种及一些实生单株的模糊综合评价指数较高,它们的果实综合性状表现较优,建议作为优良品种和单株加以开发和利用。部分单个性状比较优良的实生单株虽不适合于直接推广种植,但可作为柿品种改良的资源加以利用。 相似文献