伞形科棱子芹属部分种类果实结构的比较解剖学研究

采用石蜡切片法对伞形科(Apiaceae)棱子芹属(PleurospermumHoffm.)的宝兴棱子芹〔P.benthamii(Wall.ex DC.)Clarke〕和松潘棱子芹(P.franchetianumHemsl.)、西藏棱子芹(P.hookeriClarke var.thomsoniiClarke)和太白棱子芹(P.giraldiiDiels)、康定棱子芹(P.prattiiWolff)和瘤果棱子芹(P.wrightianumde Boiss.)的果实横切面的解剖结构特征进行了详细观察和比较分析。结果表明:6种植物虽然在外部形态上两两相似,但彼此间的果实解剖结构特征却存在一定的差异。共同特征是果棱均比较发达,且外果皮与中果皮分离,常形成空腔,每个果棱有1个明显的维管束,中果皮高度退化,果壁均很薄,棱槽和合生面均有油管,其中合生面油管数为棱槽油管数的2倍;差异主要表现在果实横切面外形、果体的压扁程度、果棱的发达程度、外果皮拱起程度及角质层的有无和厚度、维管束大小和着生位置、棱槽油管数以及合生面与侧棱的关系等方面。根据观察结果认为康定棱子芹与瘤果棱子芹不宜合并,建议将西藏棱子芹与太白棱子芹予以合并。     

现代教育理论在生物科技活动中的应用

以认知学习理论、建构主义理论、创新教育理论、多元智能理论、合作学习理论、服务学习理论为例,初步探讨了教育理论在生物科技活动中的应用。     

植物性杀虫剂防治白蚁研究进展

白蚁是建筑物和树木的重要害虫,利用化学方法对其种群进行控制仍是当前减少白蚁危害的主要措施。但使用化学杀虫剂对生态环境和人类健康带来的问题促使人类去寻找一些环境友好型生物农药来代替化学制品,而植物性杀虫剂由于其优点而越来越受到重视。本文综述了目前在白蚁防治中有杀虫潜能的植物种类、主要分布科目及作用效果,探讨了植物性杀虫剂防治白蚁存在的问题,同时对植物性杀虫剂应用于白蚁防治进行了展望。     

Enhanced Phenolic Diterpenes Antioxidant Levels Through Non-transgenic Approaches

Plant-derived antioxidants are essential in our diet, and antioxidant composition is a key determinant of the quality of plant extracts of interest to the pharmaceutical and food industries. By using carnosic acid as an example of a key antioxidant constituent of rosemary and sage extracts, we discuss the importance of studying non-transgenic approaches to enhancing antioxidant levels in plants and improving the antioxidant composition of plant extracts. In contrast to other terpenoids or phenolic compounds, carnosic acid has only been found in some Labiatae species, such as rosemary and sage. Carnosic acid has medicinal properties; it is a potent antioxidant and protects skin cells against UV-A radiation and cancer. Furthermore, it has been used as a preservative in food and non-food products, displaying important antimicrobial effects. However, the key steps involved in its biosynthesis remain largely unknown, and thus non-transgenic approaches are required to increase its level in plant extracts. Dried rosemary or sage leaves can contain between 0.1% and 7% carnosic acid, depending on the species and variety, but also on plant growth conditions, sample treatment and mode of extract preparation. Furthermore, leaf age, salinity and ionic interactions can also have a significant effect on biosynthesis and therefore have a strong impact on the total antioxidant potential of rosemary and sage extracts. Non-transgenic approaches, used in these or other species, can significantly increase antioxidant levels and therefore provide very significant improvements in the quality of several botanical extracts used in industry, and can be applied as either an alternative or a complement to transgenic approaches.

Enhanced Phenolic Diterpenes Antioxidant Levels Through Non-transgenic Approaches

All authors

T. Tounekti &; S. Munné-Bosch

https://doi.org/10.1080/07352689.2012.696457

Published online:

26 October 2012

FIG. 1 Chemical structure of synthetic and natural plant-derived antioxidants. Note that the hydroxyl groups in the ortho-position at C₁₁ and C₁₂ of the carnosic acid molecule provide high antioxidant properties (color figure available online).     

46.

Teaching about Scientific Origins: Taking Account of Creationism     

《Journal of biological education》2012,46(4):188-190

The purpose of this study was to develop a model for measuring experimental design ability based on functional magnetic resonance imaging (fMRI) during biological inquiry. More specifically, the researchers developed an experimental design task that measures experimental design ability. Using the developed experimental design task, they measured both the paper experimental design ability and the fMRI experimental design ability of subjects. Subjects’ paper experimental design ability was measured using the quotient equation of experimental design ability, and their fMRI experimental design ability using the brain connectivity coefficient. According to the fMRI results, differences in design ability existed among subjects in terms of brain connectivity coefficient level during the experimental design task. The experimental design ability brain connectivity coefficient level and quotient for each subject were analysed. Statistically significant correlations between subjects’ connectivity strength level among brain activation regions and quotient value guided the establishment of a measuring model. The model measured experimental design ability and could predict an individual’s experimental design ability quotient using his or her brain connectivity coefficient. Hence, the model developed for this study for measuring experimental design ability based on fMRI may serve as a practical measurement of students’ scientific experimental design ability. Furthermore, this study could serve as a founding theory for measuring models of other scientific processing abilities such as observation, question generation, classification, hypothesis generation and hypothesis evaluation.     

47.

Nepetalactones from essential oil of Nepeta cataria represent a stable fly feeding and oviposition repellent     

Zhu JJ  Berkebile DR  Dunlap CA  Zhang A  Boxler D  Tangtrakulwanich K  Behle RW  Baxendale F  Brewer G 《Medical and veterinary entomology》2012,26(2):131-138

The stable fly, Stomoxys calcitrans (L.) (Diptera: Muscidae), is one of the most serious pests to livestock. It feeds mainly on cattle and causes significant economic losses in the cattle industry. Standard stable fly control involving insecticides and sanitation is usually costly and often has limited effectiveness. As we continue to evaluate and develop safer fly control strategies, the present study reports on the effectiveness of catnip (Nepeta cataria L.) oil and its constituent compounds, nepetalactones, as stable fly repellents. The essential oil of catnip reduced the feeding of stable flies by >96% in an in vitro bioassay system, compared with other sesquiterpene-rich plant oils (e.g. amyris and sandalwood). Catnip oil demonstrated strong repellency against stable flies relative to other chemicals for repelling biting insects, including isolongifolenone, 2-methylpiperidinyl-3-cyclohexen-1-carboxamide and (1S,2'S)-2-methylpiperidinyl-3-cyclohexen-1-carboxamide. The repellency against stable flies of the most commonly used mosquito repellent, DEET, was relatively low. In field trials, two formulations of catnip oil provided >95% protection and were effective for up to 6 h when tested on cattle. Catnip oil also acted as a strong oviposition repellent and reduced gravid stable fly oviposition by 98%.     

48.

研究型军队总医院科研建设的实践与思考     

叶平  李勇  杨波等 《西北植物学报》2012,(11):76-77

医院的发展模式随着内外环境的变化而从粗放型向集约型过渡,科研水平的提高将对医院全面建设起到良好的支撑引领作用。立足研究型军队总医院建设需求,从科研管理体系、平台构建、品牌打造、技术创新和人才储备建设等方面进行了初步探讨。     

49.

A partial but radical solution to the problem of nomenclatural taxonomic inflation and synonymy load     

ALAIN DUBOIS 《Biological journal of the Linnean Society. Linnean Society of London》2008,93(4):857-863

     

50.

The value of harmful algal bloom predictions to the nearshore commercial shellfish fishery in the Gulf of Maine   总被引：1，自引：0，他引：1  

Di Jin  Porter Hoagland   《Harmful algae》2008,7(6):772-781

In this study, we develop a framework for measuring the value of harmful algal bloom (HAB) predictions. The framework captures the effects of both private and public responses to HABs. Using data from the New England nearshore commercial shellfish fishery and impact estimates for a large-scale HAB event in 2005, we illustrate how the potential value of HAB forecasts may be estimated. The results of our study suggest that the long-term value of a HAB prediction and tracking system for the Gulf of Maine is sensitive to the frequency of HAB events, the accuracy of predictions, the choice of HAB impact measures, and the effectiveness of public and private responses.     

[首页] « 上一页 [1] [2] [3] [4] 5 [6] [7] [8] [9] [10] [11] 下一页 » 末  页»

Teaching about Scientific Origins: Taking Account of Creationism

The purpose of this study was to develop a model for measuring experimental design ability based on functional magnetic resonance imaging (fMRI) during biological inquiry. More specifically, the researchers developed an experimental design task that measures experimental design ability. Using the developed experimental design task, they measured both the paper experimental design ability and the fMRI experimental design ability of subjects. Subjects’ paper experimental design ability was measured using the quotient equation of experimental design ability, and their fMRI experimental design ability using the brain connectivity coefficient. According to the fMRI results, differences in design ability existed among subjects in terms of brain connectivity coefficient level during the experimental design task. The experimental design ability brain connectivity coefficient level and quotient for each subject were analysed. Statistically significant correlations between subjects’ connectivity strength level among brain activation regions and quotient value guided the establishment of a measuring model. The model measured experimental design ability and could predict an individual’s experimental design ability quotient using his or her brain connectivity coefficient. Hence, the model developed for this study for measuring experimental design ability based on fMRI may serve as a practical measurement of students’ scientific experimental design ability. Furthermore, this study could serve as a founding theory for measuring models of other scientific processing abilities such as observation, question generation, classification, hypothesis generation and hypothesis evaluation.     

Nepetalactones from essential oil of Nepeta cataria represent a stable fly feeding and oviposition repellent

The stable fly, Stomoxys calcitrans (L.) (Diptera: Muscidae), is one of the most serious pests to livestock. It feeds mainly on cattle and causes significant economic losses in the cattle industry. Standard stable fly control involving insecticides and sanitation is usually costly and often has limited effectiveness. As we continue to evaluate and develop safer fly control strategies, the present study reports on the effectiveness of catnip (Nepeta cataria L.) oil and its constituent compounds, nepetalactones, as stable fly repellents. The essential oil of catnip reduced the feeding of stable flies by >96% in an in vitro bioassay system, compared with other sesquiterpene-rich plant oils (e.g. amyris and sandalwood). Catnip oil demonstrated strong repellency against stable flies relative to other chemicals for repelling biting insects, including isolongifolenone, 2-methylpiperidinyl-3-cyclohexen-1-carboxamide and (1S,2'S)-2-methylpiperidinyl-3-cyclohexen-1-carboxamide. The repellency against stable flies of the most commonly used mosquito repellent, DEET, was relatively low. In field trials, two formulations of catnip oil provided >95% protection and were effective for up to 6 h when tested on cattle. Catnip oil also acted as a strong oviposition repellent and reduced gravid stable fly oviposition by 98%.     

研究型军队总医院科研建设的实践与思考

医院的发展模式随着内外环境的变化而从粗放型向集约型过渡,科研水平的提高将对医院全面建设起到良好的支撑引领作用。立足研究型军队总医院建设需求,从科研管理体系、平台构建、品牌打造、技术创新和人才储备建设等方面进行了初步探讨。     

The value of harmful algal bloom predictions to the nearshore commercial shellfish fishery in the Gulf of Maine

In this study, we develop a framework for measuring the value of harmful algal bloom (HAB) predictions. The framework captures the effects of both private and public responses to HABs. Using data from the New England nearshore commercial shellfish fishery and impact estimates for a large-scale HAB event in 2005, we illustrate how the potential value of HAB forecasts may be estimated. The results of our study suggest that the long-term value of a HAB prediction and tracking system for the Gulf of Maine is sensitive to the frequency of HAB events, the accuracy of predictions, the choice of HAB impact measures, and the effectiveness of public and private responses.