水土保持综合治理动态的航空遥感评价

以不同时期大比例尺遥感信息源为依据,对区域水土保持综合治理进行科学地、客观地评价,并以图的形式从定性、定量、定位诸方面表示出综合治理措施的空间分布、质量水平、生态和经济效益。然后把两期的综合治理评价图进行叠合比较,编制新的综合治理评价动态图,研究综合治理评价的动态变化,并可以直观地显示出今后需要加强治理的地块以及治理方向。     

Two-dimensional rare gas solids

Monolayers of rare gas atoms adsorbed onto the basal planes of graphite play the same prototype role in two dimensions that rare gas liquids and solids do in three dimensions. In recent experiments such novel phenomena as continuous melting, the lack of true crystallinity in two dimensions, orientationally ordered fluid phases, and melting from a solid to a reentrant fluid with decreasing temperature have been observed. Because the forces in these rare gas monolayers are simple and well understood, by studying them the investigator can examine a direct interface between experiment and first principles. In order to understand the phases and phase transitions that occur in such materials, it is necessary to consider the geometrical matching of the rare gas overlayer to the graphite substrate. It turns out that in two dimensions both the local and the long-distance behavior are important. These two-dimensional rare gas solids may be effectively probed with synchrotron x-ray techniques, and the results of a series of synchrotron x-ray scattering studies of these solids are presented.     

The role of ocular muscle proprioception in visual localization of targets

The role of ocular muscle proprioception in the localization of visual targets has been investigated in normal humans by deviating one eye to create an experimental strabismus. The passively deviated eye was covered and the other eye viewed the target. With a hand-pointing task, targets were systematically mislocalized in the direction of the deviated nonviewing eye. A 4- to 6-degree error resulted when the nonviewing eye was offset 30 degrees from straight ahead. When the eye was deviated, the perceived "straight-ahead" was also displaced, by a similar amount, in the same direction. Since the efferent motor commands to the displaced and to the nondisplaced eyes are presumably identical by the law of equal innervation, the mislocalization of visual objects must be attributed to the change in proprioceptive information issued from the nonviewing, deviated eye. Thus proprioception contributes to the localization of objects in space.     

Dark adaptation: an interocular light-adaptation effect

Presentation of iight to the left eye simultaneously with adaptation of the right eye to light may accelerate dark adaptation in the right eye. The result is that the rod-cone-break and the final threshold of the rods are achieved earlier than when the right eye alone is adapted to light.     

Visual experience modifies distribution of horizontally and vertically oriented receptive fields in cats

Cats were raised from birth with one eye viewing horizontal lines and one eye viewing vertical lines. Elongated receptive fields of cells in the visual cortex were horizontally or vertically oriented-no oblique fields were found. Units with horizontal fields were activated only by the eye exposed to horizontal lines; units with vertical fields only by the eye exposed to vertical lines.     

Limulus lateral eye: properties of receptor units in the unexcised eye

Single receptor units in the compound eye of the horseshoe crab were illuminated, and their impulse discharges were recorded without removing the eye from the animal. The receptors were spontaneously active in darkness and responded without saturation over a light intensity range of 10(10) to 1. When the eye was excised, the receptors did not discharge in darkness and had an intensity range of 10(5) to 1, as is usually found. Experiments show that these and other differences result from cutting off the blood supply to the eye when it is excised. In addition, the range and shape of the intensity characteristic suggest that more than one receptor mechanism encodes light intensity in this eye.     

YOGA护眼疗法对青少年假性近视的疗效观察

目的观察YOGA护眼疗法对青少年假性近视的临床疗效．方法将符合纳入标准的136名7～15岁青少年假性近视患者作为研究对象,YOGA护眼疗法为试验组,眼保健操组为对照组,比较两组研究对象视力恢复情况．结果对照组3个月后视力高于试验前,但差异无统计学意义（P〉0．05）;试验组3个月后视力高于试验前,差异非常显著,具有统计学意义（P〈0．01）;试验组3个月后治疗效果明显高于对照组试验后,两组疗效差异具有统计学意义（P〈0．01）,结论通过YOGA护眼疗法练习的试验组恢复效果明显高于对照组及试验前,表明YOGA护眼疗法对青少年假性近视恢复具有显著疗效．     

Depression and later enhancement of the critical flicker frequency during prolonged monocular deprivation

One eye was visually deprived for 1 day, and the critical flicker frequency in the other eye was determined at the start of the deprivation period and then at intervals of 3, 6, 9, 15, and 24 hours. There was an initial depression in performance, followed by an enhancement effect. No significant changes in the critical flicker frequency were observed in the occluded eye at corresponding times; thus the depression-enhancement phenomenon is specific to the nonoccluded eye.     

Gating of retinal transmission by afferent eye position and movement signals

Vision in most vertebrates is an active process that requires the brain to combine retinal signals with information about eye movement. Eye movement information may feed forward from the motor control areas of the brain or feed back from the extrinsic eye muscles. Feedback signals elicited by passive eye movement selectively gate retinal outflow at the first relay, the dorsal lateral geniculate nucleus. The gating predominantly facilitates retinogeniculate transmission immediately after eye movement and inhibits transmission when a new steady-state eye position is achieved. These two gating effects are distributed in a complementary fashion across the dorsal lateral geniculate nucleus such that the spatiotemporal activity profile could contribute to object detection and localization.     

Sleep: suppression of rapid eye movement phase in the cat after electroconvulsive shock

Electroconvulsive shock, administered for 5 to 7 days, reduced the daily rapid eye movement sleep time of seven cats to as little as 28 percent of base line levels. After day 4, eye movements during periods of cortical activation without tonic electromyographic activity were greatlyreduced. Although partially deprived of rapid eye movements for as long as 7 days, the cats showed no compensatory rise in rapid eye movement time during the recovery period, but controls equally deprived gave significant rebounds. Rapid eye movement time of anesthetized cats was not affected by current that usually produces con vulsions; it was lowered in animals convulsed with metrazol, but the same dosage of this drug, administered so as to avoid convulsions, had little eflect.It appears that some aspect of the convulsion is responsible for lowering the rapid eye movement time.     

鱼类眼睛晶体信息分析与应用研究进展

眼睛晶体作为鱼类的硬组织之一,具有结构稳定、耐腐蚀、易获取的特性,其含有大量的蛋白质,蕴含着丰富的化学信息,并在鱼类的年龄鉴定中得到了一定程度的应用。近年来,随着生物地球化学技术的不断创新与进步,鱼类眼睛晶体的微量元素、稳定同位素信息也越来越受到国内外学者的重视。本文将依据国内外学者的研究成果,从眼睛晶体的直径与重量、微结构、微量元素和稳定同位素等方面,对鱼类的年龄鉴定、栖息环境重建、摄食生态的追踪等方面的应用进行综述,并通过分析鱼类眼睛晶体的组成成分与生长模式,比较眼睛晶体与其他组织做稳定同位素分析的优势,着重归纳总结了眼睛晶体碳氮稳定同位素在鱼类生活史信息,尤其在摄食生态、栖息环境重建等方面的研究方法、应用现状及发展前景,为以后开展相关的研究提供参考。     

Superior colliculus cell responses related to eye movements in awake monkeys

Single cell responses were recorded from the superior colliculus of awake monkeys trained to move their eyes. A class of cells that discharged before eye movements was found in the intermediate and deep layers of the colliculus. The response of the cells was most vigorous before saccadic eye movements within a particular range of directions. These cells had no visual receptive fields, and visually guided eye movements were not necessary for their discharge, since they responded in total darkness before spontaneous eye movements and vestibular nystagmus.     

Eye movement-retina delayed feedback

Time delays between ocular movement and retinal input have been studied by yoking a visual target to eye movement by experimental programming methods and a laboratory real-time computer system. The subject's task was to manipulate this eye movement-yoked target cursor to perform either compensatory or pursuit eye tracking. The computer thereafter was programmed to store input eye-movement signals and read them out after a delay interval to control the yoked visual target cursor controlled by the eye movements. Delay time constants of 0.1 second significantly affected tracking. Eye movement-retinal feedback delays appeared to have an even more marked effect on positive pursuit eye tracking.     

比目鱼类的眼睛移位和不对称的进化起源

比目鱼类外形不对称产生的机制引起人们兴趣已逾一个多世纪。从比目鱼类(鲽形目)的类群和分布、变态过程中眼睛移位机械力的来源、甲状腺激素调控眼睛移位的信号通路、比目鱼类外形左右不对称与内脏左右不对称两者调控机制之间的关系以及比目鱼类眼睛左右不对称的进化起源等5个方面,系统地介绍了比目鱼类变态发育过程中眼睛移位的研究历史。重点介绍了本实验室提出的关于眼睛移位的组织学模型,以及眼睛移位信号调控途径的最新研究进展。发现并证明眶下皮肤组织细胞分裂导致眼睛移动,而眼睛移动进一步导致额骨变形,纠正了以往假说的谬误。最后,对比目鱼类眼睛移位和不对称进化起源进行了探讨,提出了解释比目鱼类不对称进化起源的新假说。     

针刺治疗近视眼的选穴规律探讨

针刺作为一种中医特色疗法,在治疗近视眼中展现出其独特的优势。通过回顾和分析针刺治疗近视眼的相关文献,归纳从解剖、全息、经络等相关理论探讨针刺治疗近视眼的选穴规律,为近视眼的最佳治疗选穴方案提供思路。     

Visual patterned reflex present during hypothalamically elicited attack

A cat from which attack is elicited by electrical stimulation of the hypothalamus lunges more frequently toward a mouse presented to the eye contralateral to the stimulated site than it does to a mouse presented to the ipsilateral eye. This differential effect does not appear to be attributable to a temporary or permanent defect in the ipsilateral eye.     

Tbx5 and the retinotectum projection

Dorsal and ventral aspects of the eye are distinct from the early stages of development. The developing eye cup grows dorsally, and the choroidal fissure is formed on its ventral side. Retinal axons from the dorsal and ventral retina project to the ventral and dorsal tectum, respectively. Misexpression of the Tbx5 gene induced dorsalization of the ventral side of the eye and altered projections of retinal ganglion cell axons. Thus, Tbx5 is involved in eye morphogenesis and is a topographic determinant of the visual projections between retina and tectum.     

Presence of lateral eye lens crystallins in the median eye of the american chameleon

With the use of immunofluorescence techniques, gamma globulin antibody specific for the crystallins of Anolis carolinensis lateral eye lens was applied to sections through the median (parapineal) eye of Anolis carolinensis. Only the median eye lens exhibited fluorescence specific for the crystallins; other structures were negative. These results indicate that the lens of the reptilean median eye shares tissue-specific antigenic determinants with the lens of the lateral eye. This suggests a possible evolutionary relation between the two structures, based on biochemical, as well as previously reported anatomical, criteria.     

Two- rather than three-dimensional representation of saccades in monkey superior colliculus

Saccades are controlled by neurons in the brainstem reticular formation that receive input from the superior colliculus and cortex. Recently two quantitative models have been proposed for the role of the colliculus in the generation of three-dimensional eye movements. In order to test these models, three-dimensional eye movements were measured in the alert monkey to investigate whether the saccadic motor map of the superior colliculus is two-dimensional, representing retinal target vectors, or three-dimensional, representing three-dimensional motor error for the rotation of the eye. Electrical stimulation of the superior colliculus produced two-dimensional, not three-dimensional, eye movements. It is therefore concluded that the collicular motor map is two-dimensional.     

中医目诊的基本理论及临床运用

目诊是眼科临床特色,更是中医诊断学的重要组成部分,通过诊察眼睛的神、色、形、态和询问眼睛不适感觉及功能情况可以察病因、定病位、断病性、明病质、测病势。中医目诊既有着系统、成熟的五轮八廓理论,近现代也有新的发展和成就,古今皆用以辅助诊断疾病,它不单单运用于眼科临床,而且在内、外、妇、儿科等疾病的辅助诊断中也有所发挥。本文通过对中医目诊基本理论、临床运用的相关研究,有利于推动中医目诊更好的发展。