奔兔2008
NC508 Sustainable Solutions to Problems Affecting Honey Bee HealthWhite Paper: Honey bee genetics and breeding As the managed pollinator of choice for numerous crops, the honey bee is an animal of substantial importance to . agriculture. However, like many of the crops they pollinate, honey bees are not native to North America. Current honey bee populations within the United States reflect historical patterns of introduction from Old World source populations and the genetic consequences of founder events and subsequent queen propagation practices by beekeepers. With few exceptions, commercial queen propagation in the United States has relied on the production of a large number of saleable queens from a very limited number of queen mothers each generation. The ratio of daughter queens to queen mothers in these operations has averaged well over 1000:1 over the past decade (1, 2, 3). Following the establishment of parasitic honey bee mites in . beekeeping operations in the 1980's, substantial losses occurred at the national level to both managed honey bees and a formerly robust feral honey bee population (4). While queen production output was able to provide replacement queens for the beekeeping industry during this period, little effort was made to select for and incorporate genetic traits that enhanced the resistance of honey bees to parasitic mites and diseases. Unfortunately, substantial annual losses of honey bees due to parasitic mites have continued, as the mite Varroa destructor rapidly develops resistance to beekeeper applied chemical control measures. The inherent genetic capacity of some honey bees to tolerate or resist V. destructor, tracheal mites and contagious brood diseases is well known (5, 6, 7). However, there has not been a concerted effort within the queen breeding industry to develop selection protocols nor to manage even breeder queen populations without supplemental miticides and antibiotics. Exceptions include some private and public institution bee breeding programs that have adopted selection protocols based, in part, on specific assays, for traits of apicultural significance. While the impact of these programs has been limited, relative to overall queen production totals, collectively they represent a germplasm reserve of honey bee stocks that are comparatively productive, mite resistant and healthy in the face of known pathogens and stressors. Measurements that are used in selection protocols include the expression of hygienic behavior, short-term weight gain, mite and bee population growth, temperament, Varroa sensitive hygiene and reports of increased honey bee losses in the United States due to as yet undefined causes (8) makes it clear that high priority should be given to selecting and breeding honey bees that can remain healthy with minimal need for chemical inputs in the bee hive. There is preliminary evidence to suggest that selection and breeding would be an efficient and sustainable approach to deal with novel pathogens or group of pathogens, including those that may be involved in CCD (9, 10). The recent report that a virus associated with CCD is present within a population of honey bees that are currently being imported into the . in massive numbers(11) brings up another aspect that must be considered together with selection and breeding regimes, the issue of honey bee source populations and of the 26 recognized subspecies of honey bees, only 9 are known to have been sampled and introduced into the New World (12). Currently, commercial strains (Italian, Carniolan) based on two of these subspecies predominate in managed populations in the United States, although a third strain (Caucasian) was available until quite recently. Since 2004, due to perceived/projected shortfalls in managed honey bee colonies available to effect almond pollination, the . has permitted the importation of honey bees of presumptive European origin maintained in Australia. These honey bees underwent a genetic bottleneck associated with importation, similar to . populations (vis a vis sampling original sources from Europe) although, in contrast to . populations, the Australian honey bees have not been selected for any measure of resistance through exposure to parasitic mites over the past 20 years. The importation of additional honey bee germplasm for selection and breeding purposes could address several key needs. First, the importation of germplasm from Old World subspecies known to have been sampled and previously introduced to the . would provide additional genetic diversity for breeding purposes, a means to enhance and maintain sex allele diversity, to recover the commercial Caucasian strain and potentially bolster mite resistance. The latter contribution would depend on whether original Old World source populations (with their own history of mite exposure and survival) were utilized (13), rather than mite-free "introduced" populations from other New World sources. Secondly, the importation of novel honey bee germplasm from subspecies now known to be the original pollinator for crops of agricultural importance, such as A. m. pomonella in endemic forests of wild apples and pears, may provide improved pollination efficiency in crop-specific climatic conditions. Finally, as genetic markers associated with genetic resistance mechanisms or useful immunological or behavioral characteristics become available, Old World honey bee populations represent an available resource for marker-assisted identification of desirable germplasm. Currently, there is no explicit protocol . researchers and breeders to import live bees from many countries nor are there readily accessible quarantine facilities to assist in safe importation of summary, research is needed to:1) Screen available stocks of honey bees from . breeding programs for the expression of genetic characteristics associated with colony health. This could involve phenotypic measurements of heritable traits or identification of specific genes that influence these traits. In addition to known apicultural traits and measures of genetic diversity, these characteristics could include immunological resistance to pathogens and potential indicators of "CCD-resistance" detectable through novel screening protocols. 2) Develop a selection and breeding protocol for the queen breeding industry that can be implemented with existing honey bee stocks to maximize the preservation of genetic diversity (sex-allele diversity) , while still permitting measurable stock improvement in areas of disease resistance and parasitic mite tolerance. Stocks identified in the colony health screening protocol (1) as useful to breeders could be promoted within this ) Characterize additional populations of Old World honey bee stocks as potential sources to assure sustainable germplasm maintenance within the . bee breeding industry. This research will use molecular markers for the identification of specific subspecies and to label highly desirable breeding lines or lines expressing "CCD-resistance" (1). Develop a protocol to maintain these stocks within an association of involved university/private/government bee breeding facilities. Primary author: Steve Sheppard1Participants: Marla Spivak2, Greg J. Hunt31. Washington State University, shepp@. University of Minnesota, spiva001@. Purdue University, ) Schiff, . and . Sheppard. 1995. Genetic analysis of commercial honey bees (Hymenoptera: Apidae) from the southern United States. J. Econ. Entomol. 88: ) Schiff, . and . Sheppard. 1996. Genetic differentiation in the queen breeding population of the western United States. Apidologie 27:) Delaney, Schiff and Sheppard. 2007. Unpublished data4) Sanford, M. T. 2001. Introduction, spread, and economic impact of Varroa mites in North America, in; Webster ., Delaplane . (Eds.), Mites of the honey bee, Dadant and Sons, Hamilton, Illinois, pp. ) Guerra Jr., J. C. V., L. S. Gonçalves and D. De Jong. 2000. Africanized honey bees (Apis mellifera L.) are more efficient at removing worker brood artificially infested with the parasitic mite Varroa jacobsonii Oudemans than are Italian bees or Italian/Africanized hybrids. Genetics and Molecular Biology 23 89-92. 6) Spivak, M. and G. S. Reuter. 2001. Resistance to American foulbrood diseases by honey bee colonies (Apis mellifera) bred for hygienic behavior. Apidologie 32: ) Danka, R. G. and J. D. Villa. 2000. A survey of tracheal mite resistance levels in . commercial queen breeder colonies. American Bee Journal 140: ) Oldroyd, B. P. 2007. What's killing American honey bees? PLOS Biology, 5: ) Evans, J. D. and D. L. Lopez. 2004. Bacterial probiotics induce an immune response in the honey bee (Hymenoptera: Apidae). J. Econ. Entomol. 97: 752-756 10) ) Cox-Foster et al. 2007. A metagenomic survey of microbes in honey bee colony collapse disorder. Sciencexpress, 6 September 2007, ) Sheppard, . 1989. A history of the introduction of honey bee races into the United States, I and II. Amer. Bee J. 129: 617-619, 664-667. 13) De Guzman, ., . Rinderer, A. M. Frake. 2007. Growth of Varroa destructor (acari: varroidae) populations in Russian honey bee (Hymenoptera: Apidae) colonies. . Soc. Amer 100:187-195
飞翔的等待
先不说内容,首先格式要正确,一篇完整的毕业论文,题目,摘要(中英文),目录,正文(引言,正文,结语),致谢,参考文献。学校规定的格式,字体,段落,页眉页脚,开始写之前,都得清楚的,你的论文算是写好了五分之一。然后,选题,你的题目时间宽裕,那就好好考虑,选一个你思考最成熟的,可以比较多的阅读相关的参考文献,从里面获得思路,确定一个模板性质的东西,照着来,写出自己的东西。如果时间紧急,那就随便找一个参考文献,然后用和这个参考文献相关的文献,拼出一篇,再改改。正文,语言必须是学术的语言。一定先列好提纲,这就是框定每一部分些什么,保证内容不乱,将内容放进去,写好了就。参考文献去中国知网搜索,校园网免费下载。
潇湘涵雪
挑战权威论断 发现蜜蜂有发音器官 蜜蜂靠什么发出嗡嗡声?权威专家都认为:是靠翅膀振动发声。我省监利县12岁的小学生聂利大胆挑战这一说法。她说:“蜜蜂有自己的发音器官,不是靠翅膀振动发声。” 聂利是监利县黄歇口镇中心小学六年级学生。在甘肃省兰州市8月举行的第18届全国青少年科技创新大赛上, 她撰写的论文《蜜蜂并不是靠翅膀振动发声》,荣获优秀科技项目银奖和高士其科普专项奖。 2001年秋,聂利从《小学自然学习辅导》一书中得知,蜜蜂、苍蝇、蚊子等昆虫都没有发音器官,但它们在飞行时不断高速扇动翅膀,使空气振动,会产生嗡嗡的声音。后来,聂利在《十万个为什么》一书中也看到这种说法。 去年春天,她到一个养蜂场去玩,发现许多蜜蜂聚集在蜂箱上,翅膀没动,仍然嗡嗡叫个不停,她因此对教材、科普读物的说法产生怀疑,并开始试验和研究。她把蜜蜂的双翅用胶水粘在木板上,或者剪去蜜蜂的双翅,都能听到蜜蜂的叫声。两种方法交替进行了42次,结果表明:蜜蜂不振动翅膀也能发声。 为了探究蜜蜂的发音器官,她把蜜蜂粘在木板上,用放大镜仔细查找,观察了一个多月,终于在蜜蜂的双翅根部发现两粒比油菜籽还小的黑点,蜜蜂叫时,黑点上下鼓动。她用大头针捅破小黑点,蜜蜂就不发声了。她又找来一些蜜蜂,不损伤双翅,只刺破小黑点,放在蚊帐里。蜜蜂飞来飞去,再也没有声音。她将这一发现写成论文,认为蜜蜂的发音器官就是这两个小黑点。 据了解,中国教育协会、小学自然教学专业委员会会刊全文发表了聂利的论文。 昆虫专家称可能是个了不起的发现 多位从事昆虫研究的专家在接受记者采访时均称,蜜蜂是靠翅膀振动发声的。华中师范大学生命科学院副教授陈国生说,膜翅目昆虫一般没有发声器官,而蜜蜂属于膜翅目昆虫。省昆虫学会理事长、华中农业大学教授徐冠军说,还未发现有资料报道蜜蜂有发声器官。 听说聂利的发现后,徐冠军教授说,由于他没有见证聂利小朋友的试验,也从未做过这样的试验,所以尚不敢对她的发现下结论。如果这位小朋友的发现是真实的话,肯定是个了不起的发现。 巧克力对心脏有好处 除了改善精神状态,近年来,巧克力的防病作用开始得到科学家的重视。最近,《美国药物杂志》发表的一篇论文称,巧克力、尤其是黑巧克力含有一种天然抗氧化剂黄酮素,能防止血管变硬,同时增加心肌活力、放松肌肉,防止胆固醇在血管内积累,对防治心血管疾病有一定功效。 其实,这已不是科学家第一次提出巧克力的防病功效,希腊和德国也有过类似的研究。去年9月,英国权威医学杂志《柳叶刀》发表了美国的一份研究报告,指出巧克力可预防心脏病。美国加州大学的安德鲁·瓦特豪斯也发现:黑巧克力和红酒、水果、蔬菜一样,含有酚醛类物质(黄酮素就是其中一种),能杀死导致癌症和心脏病的受损细胞。日本的研究还表明:从巧克力中提取的酚醛类物质能提高血液的免疫力。 前不久,据《美国临床营养学杂志》报道,意大利拉奎拉大学的研究人员做了一个试验:让15名健康人连续15天每天吃100克黑巧克力,结果发现,他们的血压有所降低,而对胰岛素的敏感度则得到加强。但是,志愿者们连续15天每天吃100克白巧克力后,就没有收到这样的效果。因此,医生们估计,黑巧克力对糖尿病患者可能有一定的帮助作用。 另外,英国伦敦西敏斯特大学的克洛博士发现,巧克力可以预防感冒。他指出,巧克力的气味能促使男性免疫系统产生一种名为“免疫球蛋白A”的抗体,它可以对付身体上的各种“小毛病”如感冒等。 除了这些实实在在的保健防病作用,科学家们还指出,巧克力中还含有多种营养成分,比如有抗氧化作用的维生素E、镁;人体必需的钾、铁和鞣酸等,对儿童大脑发育大有好处的卵磷脂;果仁、牛奶巧克力还会加入一些其他的营养成分。另外,巧克力的原料可可豆中含有大量黄烷醇,它也具有保健防病的作用。 在科学家们的研究中,巧克力的一些“害处”也得到了澄清。研究发现,巧克力中的脂肪不会影响胆固醇水平。胆固醇正常的人在连续食用一个月的可可酱或纯巧克力后,胆固醇指标并未升高。此外,研究还表明,巧克力既不会引发粉刺和暗疮,也不会造成龋齿。 专家们推荐多吃黑巧克力 由于近年来对巧克力的认识和舆论宣传不断加深、更新,所以,在欧洲等地,巧克力的消费量明显上升。在法国,10年来巧克力的产量上升了33%,达40万吨。 在人们对巧克力的关注程度不断上升的同时,黑巧克力开始唱起了“主角”。一个原因是在巧克力的保健作用中,它显得特别“突出”;另外一个原因就是,黑巧克力是含糖量和脂肪含量最低的巧克力之一。在法国,有81%的人将黑巧克力作为购买巧克力的首选。去年,由于媒体纷纷报道黑巧克力的保健作用,日本各大商场甚至出现了抢购的场面。 尽管巧克力好处很多,但是,这世上毕竟没有十全十美的食品。对于巧克力,专家们的意见仍然是“适量食用”。本报驻法国记者在法国卫生部的网站上看到,食品卫生公告就是用“适量”一词来指导人们食用巧克力。在巴黎,一家名叫“可可与巧克力”的食品店的店主诺拉女士告诉记者,巧克力虽然营养丰富,但是,它的热量不低,每天的食用量最好还是控制在100克以内。本报驻加拿大记者的朋友、营养保健食品专家詹姆斯博士也持有同样的观点。他认为,巧克力含糖较多,肥胖者还是少吃为妙;一般人每天的食用量也别超过100克。还有专家认为,巧克力的营养成分不均衡,容易产生饱腹感,影响正常饮食,故儿童不宜多吃。而成人吃多了巧克力,也可能产生厌食、恶心、无力、抵抗力变差等“巧克力综合征”。
没有影响。奶茶是我国少数民族的一种传统茶俗,发展至今已经成为年轻消费群体的必备饮品之一,奶茶利润丰厚,行业内外竞争激烈。本文以“蜜雪冰城”为例,以重庆市高校大学
NC508 Sustainable Solutions to Problems Affecting Honey Bee HealthWhite Paper:
病情分析: 你好,这三种东西可以一起泡水饮用,有一定美白作用 指导意见: 红枣可以健脾胃,生姜可以疏通人体经络,蜂蜜能养颜润肺补气
只要不逾越对方的底线,就可以让两个人的感情更加的长久,还有就是不应该问一些对方特别隐私的问题,还有就是不应该插手对方的感情。
点击了解更多加盟项目1.首先从食材上:果茶一类基本上都是果酱加果糖糖蜜然后加一定比例的红茶绿茶或者四季春茶,再加冰块加纯净水,柠檬系列的一般会放四片柠檬,有标准