植食性昆虫产卵寄主选择影响因素 及机制的研究进展

昆虫产卵行为在昆虫与寄主的协同进化中起着重要作用,而母代产卵偏好性和子代生长发育情况的关系是植食性昆虫与寄主植物协同进化研究的核心.文章综述了寄主种类、环境丰富度、寄主生长发育状况和寄主被同种其他个体的利用程度等对植食性昆虫产卵寄主选择的影响,以及嗅觉、视觉和触觉在植食性昆虫产卵寄主选择过程中的作用机制.提出今后应从昆虫视觉生态学和听觉生态学两个角度深入研究植食性昆虫的产卵行为,尤其是加强植食性昆虫与环境中光信号间的联系及如何利用光信号进行寄主定位、 植食性昆虫产卵行为过程中是否利用听器进行声波测探定位产卵寄主及不同波段声音对植食性昆虫产卵行为的影响等研究,为研究害虫行为调控措施开拓新思路.     

Inheritance of a cardiac arterial asymmetry in mice

A pair of coronary arteries supplies the interventricular septum of the heart of Mus musculus. The members of this pair tend to be of unequal size, which permits distiniction between specimens displaying left asymmetry and those showing righit asymmetry. Three inbred strains (C57BL/1O, DBA/1, and Bulb/c) differ with regard to this asymmetry. However, variation exists within strains, which suggests that nongenetic factors also influence the development of the asymmetry. Right arterial asymmetry is dominant over left asymmetry.     

Auditory pathways to the frontal cortex of the mustache bat, Pteronotus parnellii

In primates, certain areas of the frontal cortex play a role in guiding movements toward visual or auditory objects in space. The projections from auditory centers to the frontal cortex of the bat Pteronotus parnellii were examined because echolocating bats utilize auditory cues to guide their movements in space. An area in the frontal cortex receives a direct projection from a division of the auditory thalamus, the suprageniculate nucleus, which in turn receives input from the anterolateral peri-olivary nucleus, an auditory center in the medulla. This pathway to the frontal cortex bypasses the main auditory centers in the midbrain and cortex and could involve as few as four neurons between the cochlea and the frontal cortex. The auditory cortex is also a major source of input to the frontal cortex. This area of the frontal cortex may link the auditory and motor systems by its projections to the superior colliculus.     

Sending sound to the brain

The cochlear implant, a microelectrode array that directly stimulates the auditory nerve, has greatly benefited many individuals with profound deafness. Deaf patients without an intact auditory nerve may be helped by the next generation of auditory prostheses: surface or penetrating auditory brainstem implants that bypass the auditory nerve and directly stimulate auditory processing centers in the brainstem.     

Auditory induction: perceptual synthesis of absent sounds

Within certain auditory patterns, fainter sounds may be "heard" clearly when replaced by louder sounds having appropriate spectral compositions. This auditory induction of fainter by louder sounds can cancel the perceptual effects of masking. Phonemic restorations, which have been reported previously, appear to be a specialized application to speech of the much broader phenomenon of auditory induction. The rules governing auditory induction indicate that it helps maintain stable auditory perception in our frequently noisy environment.     

信息不对称对农户生产行为的影响分析

阐述了农产品供给过程中的信息不对称产生的根源,探讨了信息不对称对农户生产行为选择的影响,并证明了通过斯宾塞-莫里斯条件去提高信息不对称市场的交易效率是可行的,最后根据这个条件的实现提出了改善农户生产行为的若干建议。     

Vision guides the adjustment of auditory localization in young barn owls

Barn owls raised with one ear plugged make systematic errors in auditory localization when the earplug is removed. Young owls correct their localization errors within a few weeks. However, such animals did not correct their auditory localization errors when deprived of vision. Moreover, when prisms were mounted in front of their eyes, they adjusted their auditory localization to match the visual error induced by the prisms, as long as the visual and auditory errors were within the same quadrant of directions. The results demonstrate that, during development, the visual system provides the spatial reference for fine-tuning auditory localization.     

Comparison of the effects of delayed auditory feedback on speech and key tapping

Delaying the return of a speaker's vocal output to his ears (the auditory feedback) radically changes his speech (1). The present report concerns the effect of delayed auditory feedback on simple key-tapping tasks. Evidence is presented which indicates that changes in speech and key tapping under delayed auditory feedback are analogous.     

Spatiotemporal pattern of neural processing in the human auditory cortex

The principles that the auditory cortex uses to decipher a stream of acoustic information have remained elusive. Neural responses in the animal auditory cortex can be broadly classified into transient and sustained activity. We examined the existence of similar principles in the human brain. Sound-evoked, blood oxygen level-dependent signal response was decomposed temporally into independent transient and sustained constituents, which predominated in different portions-core and belt-of the auditory cortex. Converging with unit recordings, our data suggest that this spatiotemporal pattern in the auditory cortex may represent a fundamental principle of analyzing sound information.     

斑马鱼胚胎左右不对称发育的研究现状与展望

脊椎动物单从体表特征来看,一般呈两侧对称,但是大多数内脏器官和系统在体内多为不对称分布,而且这种分布方式对于器官或系统功能的行使是必须的。左右不对称发育起始于胚胎时期,打破了机体两侧对称的发育模式,在不同脊椎动物中均很保守。目前利用斑马鱼为模式生物,对胚胎左右不对称发育的研究已经取得了一系列进展,包括临时器官Kupffer’s囊泡的形成、左右不对称发育信号在侧板中胚层中的传递、器官不对称分布等。本文就近年来以斑马鱼为模式生物对胚胎左右不对称发育机制研究的进展进行综述。     

Auditory association cortex lesions impair auditory short-term memory in monkeys

Monkeys that were trained to perform auditory and visual short-term memory tasks (delayed matching-to-sample) received lesions of the auditory association cortex in the superior temporal gyrus. Although visual memory was completely unaffected by the lesions, auditory memory was severely impaired. Despite this impairment, all monkeys could discriminate sounds closer in frequency than those used in the auditory memory task. This result suggests that the superior temporal cortex plays a role in auditory processing and retention similar to the role the inferior temporal cortex plays in visual processing and retention.     

Developmental stability of buckwheat (Fagopyrum esculentum Moench.) after treatment with biostimulants of plants

The treatment of buckwheat with biostimulants Floravit E and Atonic Plus in dilutions 10^?2–10^?3 and 3 × 10^?2, accordingly, had no effect on the stability and development of plants, as one can judge by the fluctuating asymmetry of metrical and meristic traits. Treatment with Atonic Plus led to a reduction of fluctuating asymmetry when control plants had a high value of asymmetry. Floravit E in the dilution 10^?1 caused an increase of fluctuating asymmetry of half leaf width. The same effect was observed when growing buck-wheat in a lead-contaminated soil.     

高校图书馆文献采访工作中的信息不对称及其对策

信息不对称理论是微观信息经济学研究的一个核心内容,在图书馆文献采访活动中,也普遍存在着信息不对称现象。在此探讨了两种信息不对称的表现形式:一种来源于图书馆和书商之间;另一种是图书馆和读者之间;运用信息不对称理论,分析了其成因并提出了抑制措施,以便高校图书馆更好地为读者服务,促进高校图书馆健康有序发展。     

信息不对称引发的农产品市场交易问题及对策——基于农产品产业链视角

信息经济学认为,在现实市场交易中各主体拥有的信息是不对称的,信息不对称现象同样也存在于农产品交易市场中。基于农产品产业链视角,总结了3类突出的信息不对称现象,并分析了这些信息不对称引发的农产品市场交易问题,最后从市场自发机制和政府干预2个角度提出了相关对策。     

Gated visual input to the central auditory system

The central auditory system translates sound localization cues into a map of space guided, in part, by visual experience. In barn owls, this process takes place in the external nucleus of the inferior colliculus (ICX). However, to date, no trace of visual activity has been observed in this auditory nucleus. Here we show that strong visual responses, which are appropriate to guide auditory plasticity, appear in the ICX when inhibition is blocked in the optic tectum. Thus, visual spatial information is gated into the auditory system by an inhibitory mechanism that operates at a higher level in the brain.     

青藏高原东缘高寒草甸风毛菊属4个优势种的核型研究

对青藏高原东缘高寒草甸风毛菊属的球花雪莲(S aussurea g lobosa Chen.)、钝苞雪莲(S.n ig rescensM ax im.)、羽裂风毛菊(S.p inna tid enta ta L ipsch.)和林生风毛菊(S.sy lva tica M ax im)4个优势种植物的染色体数目和核型进行了研究。结果表明,球花雪莲的核型公式为2n=2x=32=14m+18sm,属2B型,核型不对称系数为64.8%;钝苞雪莲的核型公式为2n=2x=32=10m+22sm,属2B型,核型不对称系数为66.1%;羽裂风毛菊核型公式为2n=2x=28=24m+4sm,属2B型,核型不对称系数为58.6%;林生风毛菊的核型公式为2n=2x=34=10m+24sm,属3B型,核型不对称系数为64.6%。钝苞雪莲较其他3种风毛菊属植物进化。     

Visual instruction of the neural map of auditory space in the developing optic tectum

Neural maps of visual and auditory space are aligned in the adult optic tectum. In barn owls, this alignment of sensory maps was found to be controlled during ontogeny by visual instruction of the auditory spatial tuning of neurons. Large adaptive changes in auditory spatial tuning were induced by raising owls with displacing prisms mounted in spectacle frames in front of the eyes; neurons became tuned to sound source locations corresponding to their optically displaced, rather than their normal, visual receptive field locations. The results demonstrate that visual experience during development calibrates the tectal auditory space map in a site-specific manner, dictating its topography and alignment with the visual space map.     

浅议农产品跨境电商中的信息不对称问题

本文首先深入分析了农产品跨境电商中信息不对称的表现及成因,其后阐述了信息不 对称对农产品跨境电商活动的影响,最后提出了一系列农产品跨境电商中的信息不对称问题的 解决策略和措施。     

A neural map of auditory space in the owl

Auditory units that responded to sound only when it originated from a limited area of space were found in the lateral and anterior portions of the midbrain auditory nucleus of the owl (Tyto alba). The areas of space to which these units responded (their receptive fields) were largely independent of the nature and intensity of the sound stimulus. The units were arranged systematically within the midbrain auditory nucleus according to the relative locations of their receptive fields, thus creating a physiological map of auditory space.     

信息不对称对高校特色数据库建设的影响及抑制策略

运用信息经济学中的信息不对称理论,分析高校图书馆特色数据库建设中信息不对称的表现及成因,提出若干减少其负面影响的对策。