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101.
Heterodera zeae, the corn cyst nematode, is redescribed and illustrated with comparative details and measurements of females, cysts, and larvae from Maryland, USA; and India. Scanning electron micrographs o f specimens from the United States are also presented. Revised measurements for the larval stylet and new diadnostic characters, especially in the cyst cone, for H. zeae are given. The relationship of H. zeae to close species is discussed.  相似文献   
102.
Differences among taxa in sexual size dimorphism of adults can be produced by changes in distinct developmental processes and thus may reflect different evolutionary histories. Here we examine whether divergence in sexual dimorphism of adults between recently established Montana and Alabama populations of the house finch (Carpodacus mexicanus) can be attributed to population differences in growth of males and females. In both populations, males and females were similar at hatching, but as a result of sex-specific growth attained sexual size dimorphism by the time of independence. Timing and extent of growth varied between the sexes: Females maintained maximum rates of growth for a longer time than males, whereas males had higher initial growth rates and achieved maximum growth earlier and at smaller sizes than females. Ontogeny of sexual dimorphism differed between populations, but in each population, sexual dimorphism in growth parameters and sexual dimorphism at the time of nest leaving were similar to sexual dimorphism of adults. Variation in growth of females contributed more to population divergence than did growth of males. In each population, we found close correspondence between patterns of sexual dimorphism in growth and population divergence in morphology of adults: Traits that were the most sexually dimorphic in growth in each population contributed the most to population divergence in both sexes. We suggest that sex-specific expression of phenotypic and genetic variation throughout the ontogeny of house finches can result in different responses to selection between males and females of the same age, and thus produce fast population divergence in the sexual size dimorphism.  相似文献   
103.
This paper is focused on the model identification of a Micro Air Vehicle (MAV) in straight steady flight condition. The identification is based on input-output data collected from flight tests using both frequency and time dorrtain techniques. The vehicle is an in-house 40 cm wingspan airplane. Because of the complex coupled, multivariable and nonlinear dynamics of the aircraft, linear SISO structures for both the lateral and longitudinal models around a reference state were derived. The aim of the identification is to provide models that can be used in future development of control techniques for the MAV.  相似文献   
104.
Lukacs PM  Burnham KP 《Molecular ecology》2005,14(13):3909-3919
The use of noninvasive genetic sampling to identify individual animals for capture-recapture studies has become widespread in the past decade. Strong emphasis has been placed on the field protocols and genetic analyses with fruitful results. Little attention has been paid to the capture-recapture application for this specific type of data beyond stating the effects of assumption violations. Here, we review the broad class of capture-recapture methods that are available for use with DNA-based capture-recapture data, noting the array of biologically interesting parameters such as survival, emigration rates, state transition rates and the finite rate of population change that can be estimated from such data. We highlight recent developments in capture-recapture theory specifically designed for noninvasive genetic sampling data.  相似文献   
105.
106.
Hydroxycinnamic acid amides have been identified as the main phenolic constituents in the reproductive organs of a range of flowering plants.  相似文献   
107.
猫尾射的生药鉴别   总被引:3,自引:0,他引:3  
猫尾射是闽台民间传统的膳用中草药。本文对猫尾射的植物形态、生药性状、显微特征(包括根横切面、粉末装片)进行系统观察和理化鉴别,为其生药鉴定提供参考。  相似文献   
108.
We developed multiplex polymerase chain reaction methods to identify five Orius (Heteroptera: Anthocoridae) species that occur commonly in Japan: Orius sauteri, Orius minutus, Orius strigicollis, Orius nagaii, and Orius tantillus. The method amplified internal transcribed spacer 1 of the nuclear ribosomal DNA by using five primers simultaneously and produced species-specific banding patterns upon agarose gel electrophoresis. Reliability of the method was tested for 350 individuals of 23 strains, and consistent results were obtained. Dichotomous keys are also provided for easy and quick species identification.  相似文献   
109.
艳山姜为姜科山姜属植物,艳山姜(Alpinia zerumbet)的干燥成熟果实,是贵州少数民族地区的传统习用药物,艳山姜在贵州省的种植面积已超过130 hm~2,是贵州"南药"的第一大宗产品,也是治理石漠化的重要经济植物,其自然资源非常丰富,亦是民间常用的香料植物资源。该研究采用性状、显微及理化鉴定方法,对艳山姜果实进行了系统的生药学研究,并对α-蒎烯、莰烯、β-蒎烯及1,8-桉叶油醇四个主要心血管药理活性成分进行含量分析。结果表明:艳山姜果实性状鉴别特征为果皮见12~20条纵棱隆起,顶端具花被残基突起,种子团由白色隔膜分为3瓣,每瓣具种子8~20粒不等,较易散落。显微鉴别特征为:种子横切面具1~2列油细胞,外胚乳细胞含淀粉粒,并可见细小草酸钙方晶;果实粉末可见螺纹导管、草酸钙方晶、淀粉粒、石细胞等。气相色谱法测得艳山姜果实挥发油中α-蒎烯、莰烯、β-蒎烯及1,8-桉叶油醇的平均含量分别为4.292%、3.966%、9.703%、27.171%。该研究的性状、显微鉴别方法准确、简单、易行,可作为艳山姜药材的鉴别依据;气相色谱含量测定方法重现性好,测定结果精确可靠,可用于艳山姜果实挥发油的含量测定。该研究结果为艳山姜药材的鉴定及进一步开发利用提供科学参考。  相似文献   
110.
Passive integrated transponder (PIT) tags allow a range of individual‐level data to be collected passively and have become a commonly used technology in many avian studies. Although the potential adverse effects of PIT tags have been evaluated in several species, explicit investigations of their impacts on small (<12 g) birds are limited. This is important, because it is reasonable to expect that smaller birds could be impacted more strongly by application of PIT tags. In this study, we individually marked Black‐capped Chickadees (Poecile atricapillus), a small (circa 10 g) passerine, at the University of Alberta Botanic Garden to evaluate potential lethal and sublethal effects of two PIT tagging methods: attachment to leg bands or subcutaneous implantation. We used a Cox proportional hazards model to compare the apparent survival of chickadees with leg band (N = 79) and implanted PIT tags (N = 77) compared with control birds that received no PIT tags (N = 76) over the subsequent 2 years based on mist net recaptures. We used radio‐frequency identification (RFID) redetections of leg band PIT tags to evaluate sex‐specific survival and increase the accuracy of our survival estimates. We also used a generalized linear regression model to compare the body condition of birds recaptured after overwintering with leg band PIT tags, implanted PIT tags, or neither. Our analysis found no evidence for adverse effects of either PIT tagging method on survival or body condition. While we recommend carefully monitoring study animals and evaluating the efficacy of different PIT tagging methods, we have shown that both leg band and subcutaneously implanted PIT tags ethical means of obtaining individualized information in a small passerine.  相似文献   
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