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1.
周宇晨 《生物学通报》2011,46(10):10-13
从机体因素和疫苗因素2个方面对乙肝疫苗免疫后无应答机制做了综述,机体方面包括基本因素、遗传因素和免疫因素3个方面.疫苗因素主要集中在新型佐剂方面.目前针对机体方面影响因素的解决方案较少,研究依然主要集中在机制方面,而新型佐剂的应用,提升了疫苗的免疫效果,减少了疫苗的无应答或低应答的发生.  相似文献   

2.
昆虫的产卵是昆虫生物学最重要的内容之一,雌虫产卵量的多少受多种环境因素和雌虫个体因素的影响。本文从环境因素和个体因素两方面综述了影响雌虫产卵量的因素,包括温度、湿度、光照、温室气体、食物、密度、音乐、个体体型、交配、滞育等,分析了各因素影响产卵量的原因及其规律,并提出了未来的研究发展方向。不仅丰富了昆虫繁殖生物学的内容,也为田间害虫和室内养殖昆虫管理过程中的数量预测以及种群调控提供了科学依据。  相似文献   

3.
在文献分析的基础上,分析了初中生生物学前科学概念的来源。其主要来源有:1)个体的日常生活经验;2)自己的判断、推理;3)生物学概念的术语;4)教学资料;5)教师的前科学概念;6)同学、朋友;7)学生遗忘了;8)相近概念的混淆;9)社会媒体;10)家人。这些来源依内-外部的维度,可分为内部因素和外部因素;依人-物的维度,可分为人的因素和物的因素;依教育领域的维度,可分为学校教育因素、社会教育因素和家庭教育因素。  相似文献   

4.
螳螂种群增长制约因素分析   总被引:1,自引:0,他引:1  
在自然界中,螳螂种群数量的增长受到多种因素的制约。作者通过野外调查和实验室饲养观察,以及对国内外相关资料的查阅,对这些主要制约因素逐一进行了分析和归纳。在影响螳螂分布与制约种群数量增长的这些因素中,自然条件中的温度是关键的制约因素,食物、天敌、自残行为、人类活动等是重要的制约因素。  相似文献   

5.
陕西省油松人工林的生产力与生态因素的相关分析   总被引:5,自引:0,他引:5  
本文研究了油松林分生产力和生态因素的关系,分析了地理、地形,气候、林分和土壤因素单独及综合对林分生产的影响,得到84个逐步回归方程和全回归方程,选出了6个最优方程。计算了各林分外部因素的标准回归系数,找出了影响林分不同部分生产量的因素重要性序列,还探讨了生产力与生态因素相关关系的研究在实践中的应用。  相似文献   

6.
肠道微生物与人类健康状况直接相关。目前,微生物研究者已对影响人及模式动物(主要为鼠和猪)肠道微生物菌群结构的因素展开了广泛研究,取得了较大研究进展。本文综述了影响肠道微生物菌群结构的因素,主要有年龄、宿主基因型、宿主所处环境、食物和抗生素等,以使人们了解和控制这些因素,从而保持良好的健康状态。  相似文献   

7.
扎龙湿地丹顶鹤和白枕鹤求偶期觅食生境对比分析   总被引:8,自引:0,他引:8  
在2003~2004年3~4月,利用定点观察法、GPS定位法、样方法、因子测定法,对扎龙保护区繁殖的丹顶鹤和白枕鹤求偶期的觅食生境进行了对比研究.结果表明,在扎龙湿地,求偶期丹顶鹤与白枕鹤对觅食生境的选择具有显著差异.丹顶鹤觅食生境比较单一,主要集中水域觅食(如芦苇沼泽),微生境选择以食物因素为主,其次是隐蔽因素、水因素和标识因素;白枕鹤觅食生境比较多样化,主要集中于陆地(如苔草沼泽、农田和火烧地),微生境选择要求严格,以“有效食物”因素为主,干扰因素和水因素是次要因素.  相似文献   

8.
海草种子休眠、萌发、幼苗生长及其影响因素的研究进展   总被引:1,自引:0,他引:1  
Zhang PD  Sun Y  Niu SN  Zhang XM 《应用生态学报》2011,22(11):3060-3066
海草床是沿岸海域重要的初级生产者,具有极其重要的生态价值和经济价值,是重要的浅海生态系统之一.本文综述了近年来国内外对海草种子休眠、萌发、幼苗生长及其影响因素的研究进展,总结了海草种子的休眠方式和休眠历期及其影响因素,探讨了盐度、温度、光、激素、溶解氧及种群等因素对海草种子萌发、幼苗存活和生长的影响,并对目前研究中存在的问题和今后的研究方向进行了展望.  相似文献   

9.
基于弹性系数的江苏省能源生态足迹影响因素分析   总被引:3,自引:0,他引:3  
杨足膺  赵媛  付伍明 《生态学报》2010,30(24):6741-6748
在核算1985—2006年江苏省能源生态足迹的基础上,采用弹性系数方法,对江苏省能源生态足迹的影响因素进行分析和评价,包括不同影响因素的作用程度高低、不同时期主要及次要影响因素的变动等。这对促进江苏省能源与社会、经济和生态的协调发展,具有重要意义。研究结果显示:不同时期,影响江苏省能源生态足迹的主导因素不同。2003年以前,江苏省分别经历了主导因素变动、耕地因素主导和人口因素主导3个时期;2003年以后,全省第二产业比重反弹,第二产业比重偏大,产业结构不合理,成为目前促进江苏省能源生态足迹提高的主导因素。同时在2003年以后,江苏省城市化水平的迅速提高(2005年已达50%)和全省能源技术效率的下降(单位GDP能耗由0.78反弹至0.89tce/万元),这些次要因素也推动了江苏省能源生态足迹的提高。  相似文献   

10.
林可霉素生物合成培养基的优化   总被引:1,自引:0,他引:1  
以花生粉和棉籽蛋白粉取代了原培养基中的黄豆饼粉,采用响应面法对林可霉素产生菌的发酵培养基进行了优化.首先通过单因素试验及正交实验确定替代氮源及其浓度,采用Plackett-Burman实验分析各因素的主效应,选出对响应值影响较大的3个因素,即花生粉、K2HPO4和玉米浆.对这些因素做爬坡实验,确定三个重要因素的中心点浓...  相似文献   

11.
Matt Ridley, the science writer, is married to Anya Hurlbert, reader in visual neuroscience at the University of Newcastle. She studied physics at Princeton University as an undergraduate, then went to Cambridge University as a Marshall Scholar, where she took a Part III diploma in theoretical physics and an MA in physiology. She returned to the States to do the HST MD-PhD program at Harvard-MIT, studying with Tomaso Poggio for her PhD. Matt trained as a zoologist at Oxford, and after completing his PhD on the mating habits of the pheasant, turned to journalism. They met when, as science editor for The Economist, Matt interviewed Anya, and they married while he was the magazine's Washington correspondent. They moved to England, she to Oxford for postdoctoral research, he to become American editor of The Economist. After writing as a columnist for the Daily Telegraph and other papers, Matt turned to writing books: his titles include The Red Queen, The Origins of Virtue, Genome and Nature via Nurture. They now live in rural Northumberland with their two children.  相似文献   

12.
The African giant rat Cricetomys gambianus Waterhouse is found in a wide variety of habitats in Ibadan district. These include an abandoned farm in a degraded deciduous forest, a zoological garden complex, Agodi; and a forest plantation of teak (Tectona grandis L.F.), human habitation and derived Guinea savanna. They located their burrows in the most heavily shaded parts of the habitats. Burrows were found mostly inside deserted termite mounds and amongst roots of trees probably to provide insulation from heat. They are nocturnal, omnivorous rodents, feeding on a wide variety of root crops, fruits, molluscs and insects. Fruits of the oil palm (Elaeis guineensis Jacq.) or their remains were found in all burrows. Information on habitat preferences, food habits, as well as that obtained from the dimensions and design of burrows which are reported in this paper later provided a basis for the design of cages and husbandry techniques for a programme of domestication of this rodent, which is currently being carried out at University of Ibadan, Nigeria.  相似文献   

13.
The water vascular system and functional morphology of Paleozoic asteroids   总被引:2,自引:0,他引:2  
Asteroids of all geologic ages share a single basic body form, surficial skeletal arrangement, and aspects of water vascular construction. In almost all described Paleozoic species, however, either podial pores to the interior of the arm were lacking, or they are directed laterally, above the adambulacrals. They are internal and above the ambulacrals in known post-Paleozoic species and the Pennsylvanian Calliasterella. Certain features of the ambulacral skeletal arrangement also differ. Calliasterella is the closest known Paleozoic relative of post-Paleozoic asteroids. Classifications of asteroids that stress only overall form and surticial skeletal arrangement erroneously include Paleozoic and Holocene species in common ordinal or even lower level groupings. Taxonomic revision is premature: however, most known Paleozoic asteroids represent primitive lineages. Transitional forms allow reconstruction of events leading to the modern arrangement. Ampullar and skeletal arrangements of post-Paleozoic asteroids appear to offer some functional advantages over those of their precursors, but as early as the Ordovician, diverse feeding habits had evolved and ecological roles paralleled those of Holocene species.  相似文献   

14.
Synopsis Scale-eating is known for several unrelated fish groups, but few data are available on the habits of most species. General habits and feeding behavior of some lepidophagous characoids are presented and compared to other scale-eating species. The diversity of morphology, habits, and behavior of scale-eating fishes is great, and few patterns are shared by the specialized scale-eaters. Except for modified teeth, no morphological characteristic permits identifying a fish as a specialized lepidophage. Hunting tactics consist mainly of ambush, stalking, or disguise (aggressive mimicry). Scale-removal may be accomplished by a jarring strike with the snout, generally directed at the prey's flank, or by biting or rasping. The mode of scale-removal seems to reflect primarily the disposition of the jaws and the teeth. Scales are swallowed directly if taken in the mouth; if not, they are gathered as they sink, or picked up from the bottom. Scale-eating is probably a size-limited habit. Specialized scale-eaters rarely exceed 200 mm, most ranging near 120 mm. Some species eat scales only when young; most take other food items in addition to scales. Scale-eating habits probably arose from trophic or social behaviors. These are not mutually exclusive and, indeed, may have acted together during the evolution of lepidophagy. Suggested trophic origins include scraping epilithic algae, modified piscivory, and necrophagy. Social origins include intra- and interspecific aggressive behavior during feeding.  相似文献   

15.
The importance and application of an understanding of the feeding habits of deer in their management is stressed. Methods of diet determination are briefly outlined. Factors affecting the feeding habits are complex and include social ones, weather and available shelter, interactions with other species of animals, feeding patterns and the quality, quantity and availability of the food.  相似文献   

16.
Synopsis Stomach contents of the clingfish Diademichthys lineatus, 10–56 mm standard length, revealed changes in food habits with growth and sexual differences. Soon after settlement, D. lineatus obtained food from their host sea urchin (genus Diadema) and other associated symbionts. They became less dependent on the host with growth. The juveniles ate pedicellariae and sphaeridia of the host and commensal copepods, whereas the adult fish ate burrowing bivalves in corals as well as tube feet of their host and eggs of a commensal shrimp. The young fish were transitional in their food habits. The change in food habits of the fish coincided with behavioral changes; i.e. enlargement of home ranges and less dependency on the host. The adult females, having a longer snout, ate shrimp eggs and bivalves more frequently than the adult males, which ate tube feet of the host more often than the females did. Sexual difference in food habits was apparent after the sex of the fish became identifiable by comparing snout shapes. The polygynous mating system of this species suggests that conspicuous sexual dimorphism might have developed under sexual selection. However, niche partitioning of food is also likely to be related to this sexual dimorphism.  相似文献   

17.
重大入侵害虫草地贪夜蛾的研究进展   总被引:1,自引:0,他引:1       下载免费PDF全文
草地贪夜蛾Spodoptera frugiperda是一种杂食性检疫害虫,原产于美洲热带和亚热带地区,寄主超过350种,尤其喜欢禾本科作物,特别是玉米,具有迁飞能力强、繁殖能力强、暴食性和抗药性进化快的特点。该虫最初于2019年1月由缅甸入侵我国云南省,现已蔓延至我国26个省份。为全面了解和有效防治草地贪夜蛾,本文对其分布范围、扩散途径和原因、生活习性、危害特点以及防治措施等进行了总结和整理,并对未来的研究方向进行了讨论。  相似文献   

18.
Feeding habits of chimpanzees, red‐tail and blue monkeys on figs (Ficus) were studied in compartment N3 of Budongo Forest Reserve, western Uganda, from September 1997 to March 1998. The aim was to examine the spatial and temporal foraging habits of chimpanzees, red‐tail monkeys and blue monkeys on figs in the forest reserve. Both scan and focal sampling methods were used to assess the foraging habits of the primates. It was found that the primates fed on emerging leaves of Ficus mucuso Ficalho, F. varifolia Warb. and F. exasperata Vahl. They also preferred ripe fruits to emerging, young and unripe fruits. The primates spent 78% of the morning eating fruits and leaves and inhabited fig trees with fruits for about 4 h. Fig trees with ripe fruits attracted larger numbers of primate groups. It is concluded that information on the feeding habits of chimpanzees and monkeys is required in order to have a clear understanding of the social behaviour and pattern of movement of the primates and to assist in predicting the likely impacts of poor forest management, forest degradation and loss of food resources on their populations.  相似文献   

19.
The instream distributions and feeding habits of two species of sleeper, Eleotris acanthopoma and E. fusca, were studied in the Teima River on Okinawa Island, southern Japan. Both adult fishes inhabited the river, but their distribution patterns were found to be different. The distribution of E. acanthopoma was from the tidally influenced area to the lower part of the freshwater area, whereas E. fusca was distributed almost entirely in the freshwater area. They were found to coexist at the upper limit of the tidally influenced area and the lower part of the freshwater area. Their feeding habits were clearly different, although both species were carnivorous. Eleotris acanthopoma fed mainly on crabs in the tidally influenced area and on aquatic snails in the freshwater area, where they coexist with E. fusca. In contrast, E. fusca fed mainly on shrimps in the freshwater area. Their coexistence may result from the difference in their feeding habits.  相似文献   

20.
方静 《四川动物》1996,15(2):55-58
本文报道产于沱江的大口鲇Silurusmeridionalis成鱼阶段食性和生长等生物学资料。食物以鱼类为主,4龄前生长迅速,体长与体重相关关系方程式为:W=11.5509BL2.9801,r=0.9914,原因可能与沱江饵料丰富有一定关系。  相似文献   

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