Development of the place principle: tonotopic organization

The tonotopic organization of brainstem auditory nuclei was compared in embryonic and hatchling chickens. In embryos, neurons at any given position in these nuclei were maximally sensitive to lower frequency sounds than the best frequency after hatching. This finding indicates that neurons are maximally stimulated by sounds of different frequencies as development proceeds and supports the hypothesis that during development there is a change in the spatial encoding of frequency along the cochlea.     

A micromechanical contribution to cochlear tuning and tonotopic organization

The response properties of hair cells and nerve fibers in the alligator lizard cochlea are frequency selective and tonotopically organized with longitudinal position in the organ. The lengths of the hair-cell hair bundles also vary monotonically with longitudinal position. In this study, quantitative measurements were made of the motion of individual hair bundles in an excised preparation of the cochlea stimulated at auditory frequencies. The angular displacement of hair bundles is frequency selective and tonotopically organized, demonstrating the existence of a micromechanical tuning mechanism.     

Human taste papilla stimulation: stability of quality judgments over time

Human taste papillae are sensitive to two or more chemical stimuli. Individual papillae produce stable response patterns (quality and intensity) over a month's time. Hence, the response pattern does not appear to be affected by turnover of receptor cells.     

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.     

Receptive field organization of the S-potential

The receptive fields of S-potentials have been studied in carp retinas. The relationship between the stimulus intensity and area of stimulation was examined for each component of three different types of S-potential. It appears that for each component there is full summation over a large portion of the retina, a type of organization different from that found in the ganglion cell.     

Territorial organization of the lowland classic maya

Thus far I have discussed ancient Maya sociopolitical structure from the upper levels of the hierarchy downward. Let me now summarize their territorial organization from the bottom upward, starting at the hamlet level (Fig. 8). The smallest unit of settlement-one usually overlooked by archeological surveys in the lowland rain forest-was probably a cluster of thatched huts occupied by a group of related families; larger clusters may have been divided into four quadrants along the lines suggested by Coe (26). Because of the long fallow period (6 to 8 years) characteristic of slash-and-burn agriculture in the Petén, these small hamlets are presumed to have changed location over the years, although they probably shifted in a somewhat circular fashion around a tertiary ceremonial-civic center for whose maintenance they were partly responsible. These tertiary centers were spaced at fairly regular intervals around secondary ceremonial-civic centers with pyramids, carved monuments, and palace-like residences. In turn, the secondary centers occurred at such regular intervals as to form hexagonal patterns around primary centers, which were still larger, with acropolises, multiple ceremonial plazas, and greater numbers of monuments. In some cases, the distance between secondary centers was roughly twice the distance between secondary and tertiary centers, creating a lattice of nested hexagonal cells. This pattern, which conforms to a Western theoretical construct, was presumably caused by factors of service function, travel, and transport. The pattern was not recognized by the Maya at all. They simply recognized that a whole series of smaller centers were dependent on a primary center and therefore mentioned its emblem glyph. Linking the centers of the various hexagons were marriage alliances between members of royal dynasties, who had no kinship ties with the farmers in the hamlets. Out of the large number of primary centers available to them, the Maya selected four as regional capitals. True to their cosmology, the Maya regarded these capitals as associated with the four quadrants of their realm, regardless of their actual location. Each was the home city for a very important dynasty whose junior members probably ruled secondary centers. Since the hexagonal lattices were probably adjusted to variations in population density, each of the four quadrants of the Maya realm probably controlled a comparable number of persons. So strong was the cognized model that, despite the rise and fall of individual centers, there seem always to have been four capitals, each associated with a direction and, presumably, with a color. There is still a great deal to learn about the social, political, and territorial organization of the lowland Maya, and parts of the picture presented here need far more data for their confirmation. What seems likely is that the Maya had an overall quadripartite organization (rather than a core and buffer zone) and that within each quadrant there was at least a five-tiered administrative hierarchy of capital, secondary center, tertiary center, village, and hamlet. Perhaps most significant, there was no real conflict between the lattice-like network predicted by locational analysis and the cosmological four-part structure predicted by epigraphy and ethnology.     

特色农业发展模式综述

从产业化、区域化和生产要素3个方面探讨了特色农业发展模式,以期为各地选择与其资源禀赋和自身特色相适应的特色农业发展模式提供理论依据。     

Developmental selection of mutations

Molecular pharmacology of muscarine isomers has been studied in the rat intestine and frog heart. The significance of the peculiar finding of atropinelike action of some of the isomers is discussed.     

关于休闲观光农业发展热潮的思考

阐述了休闲观光农业的发展现状、特点及出现发展热潮的必然性,分析了休闲观光农业过热发展易出现的问题,从发展观念、规划、管理、基础设施建设、人才培养等方面探讨了政府和有关部门应该采取的对策。     

合肥市观赏鱼市场发展现状及对策

该文基于对合肥市水族市场的深入调查,总结了目前合肥市水族市场的发展现状以及存在的问题,主要包括品种质量低、高档品种匮乏,与观赏鱼相关配套设备低端,养殖技术不足,且缺乏更新力,养殖基地少规模小,市场销售方式单一,行业服务质量低等问题。并在此基础上对合肥市观赏鱼行业提出了以下建议及发展对策:加强政策扶持力度、加大观赏鱼基地和销售市场的建设、加强观赏鱼文化建设,创新销售模式,提升服务理念。努力打造具影响力品牌。     

论以人为本的学生组织文化建设

依据大学自治、学术自由和人文主义精神传统,界定了以人为本的学生组织文化的内涵和特征,从学生导向、学习导向、＂竞＂＂合＂导向、创新导向、团队导向、自治导向等6个方面确立了以人为本的学生组织文化建设的纬度,探索了以人为本的学生组织文化建设的途径。     

浅论学习型组织与行政文化创新

知识经济的到来,对政府组织的建设提出了新的要求。行政文化作为政府组织的内环境是关键的环节,对于推进政府组织的变革有着重要的作用。文章着力探讨学习型组织理念对于行政文化创新的影响,力图摒弃政府组织中个别的”官僚文化”的气息,提出以创新的精神重塑政府文化环境的观点。     

现代林业发展阶段的初步划分

以林业发展历程,两次现代化理论及林业的定位等为客观依据,从动态的、发展的视角,将我国现代林业的发展划分为5个阶段:起步阶段、发展阶段、初步实现阶段、基本实现阶段和全面实现阶段,并具体分析了各发展阶段的特点。     

Social organization in the bat Myotis adversus

Studies in which the Australian bat Myotis adversus was marked and recaptured showed that mature males tend to be solitary, are strongly attached to a particular site, and apparently defend home sites. Harem formation concurrent with mating has been observed, and the bond between the mother and her young extends beyond extends beyond nursing.