Sensory exotropia subsequent to senile cataract

INTRODUCTION Sensory exotropia is a condition of unilateral divergence as a sequela to loss of vision or long-standing poor vision in one eye,which was caused by refractive errors,unilateral aphakia or other organic reasons.Convergence insufficiency or disruption is possible.The most important aspect of the manage-ment is to find and/or eliminate and/or reverse a treatable cause of the exotropia.In clinic,the sensory exotropia secondary to senile cataract was often ob-served.Prospectively…     

随机点立体图在立体视觉测量中的实证效度分析

立体视觉是人们在观察事物过程中的一种立体知觉,又称深度知觉。在对立体视觉的敏锐度要求较高的职业中,立体视觉的好与坏会直接影响工作质量,甚至对于某些行业来说,会直接威胁到从业者的人身安全。因此,选取一种有效简捷的方法来判断从业人员的立体视觉,对立体视觉的应用有着重要的实践意义。研究目的:以测量立体视觉的传统方法三杆法为校标,检验随机点立体图的实证效度。方法:测量43名大学生的立体视觉,使用斯皮尔曼等级相关与皮尔逊相关检验随机点立体图法的校标关联效度。结果:三杆法与随机点立体图法的测量结果存在显著相关。结论:随机点立体图能有效地测量立体视觉。     

The impact of vision impairment on students’ self-concept

This study investigated the self-concept of students with vision impairment who were placed in specialist and mainstream educational settings in South Australia. Self-Concept was explored across six dimensions, namely Physical, Moral, Personal, Family, Social and Academic Self-Concepts and the Total Self-Concept. The ‘Tennessee Self-Concept Scale: Second Edition’ was administered to 25 students with vision impairment (13 females and 12 males). Participating students’ age ranged between 15 and 25 years and they were included from all levels of vision impairment. The visual acuity of the participants ranged from 6/18 or less (low vision) to 3/60 and less (blindness). Although the majority of the students with vision impairment obtained low scores on all dimensions of self-concept, namely physical, moral, personal, family, social and academic, some students obtained normal scores in relation to family and academic self-concepts. There were no significant differences between female and male students with vision impairment across the six dimensions of self-concept and thus total self-concept. These findings have implications for teachers, special educators, policy-makers and a range of professionals in the education and special education sector in enabling greater understanding of the self-concept accomplishment of the students with vision impairment. However, this study has limited scope for generalisation of the study's conclusions due to the study's small population sample size.     

Silent Reading as Determined by Age and Visual Acuity

In this study silent reading by adults ranging in age from 35 to 90 years was investigated. The texts to be read were printed in black on white paper with character sizes varying from 1–9 mm x-height (visual angle 0.19° to 1.67°). In order to separate age effects from visual-acuity effects, subjects with different levels of visual acuity (0.1–2.5 decimal acuity) participated in the experiment. Silent reading rate was employed as the dependent variable. Visual acuity affected reading rate most, followed by letter size. In normal-acuity subjects the variance in reading rates decreased as a function of age. Reading rates initially increased rapidly with increasing letter size, but after reaching an optimum gradually declined again as letters became larger. For the different acuity classes there appeared to be clearly optimal letter sizes, varying from 1.9 for the highest acuity group to 6 mm for the lowest acuity group at the 33 cm reading distance employed. However, the optimal reading rates of visually impaired subjects found in this study remained below those of individuals with normal acuity. This suggests that visual impairment is a more general neural phenomenon rather than merely a deficient optical image. The obtained reading-rate data could be accurately described by a theoretical model encompassing a decoding process and an integration process. It appeared that the model predictions were entirely determined by the smallest letter size at which reading is just possible with a specified visual acuity. It is concluded that both decoding and integration are dependent on visual acuity and that, in the absence of specific visual defects, ageing effects in reading can be completely explained by gradual lowering of visual acuity having its origin in central mechanisms.     

Readable letter size and visibility for overhead projection transparencies

Conclusions The results of this investigation would indicate that the smallersize letters (elite and pica) should be avoided in the preparation of projectuals—certainly for viewing distances beyond 20 feet. Further investigation could be, and probably should be, conducted at distances less than 20 feet to determine if anything significant would be lost by employing these smaller sizes for the closer distances. The smaller sizes are likely to be sufficient for distances of 20 feet or less. At further distances where larger-size letters are needed, probably the most feasible approach would be to use the primer type¹available in many schools. It is quite interesting to note that four of the five grades found the 6/32 inch primer size type with serif to be more readable than the 6/32 inch bulletin type without serif. Many casual observers would erroneously suggest that the simple bulletin type would be less confusing and thus more readable. Needless to say, this observation may be a phenomenon of the sample and might not similarly be observed in a replication of the study. The largest size, that which was commercially recommended (8/32 inch), did not appear necessary; the 6/32 inch elite type (primer size) was statistically equal to the larger size in four of the five grades, while in the remaining grade, the primer size actually surpassed the commercially recommended size. The three largest sizes showed approximately equal, minimal change from closer to further viewing distances. In future studies, initial measures should be made of the visual acuity of the subjects to control this possible source of variation. Additional attention also needs to be paid to the characteristics of specific letters which make them more difficult to read, regardless of size.     

世界史课堂教学模式浅议——以世界近代史教学为例

大学世界史教学应以"传道、解惑"为基本定位,着眼于拓展学生专业视野,培养其专业思维,训练其学术敏锐性。在教学过程中,教师既要始终坚持从微观分析和宏观考察两个角度对重要的历史现象和历史发展进程进行学理分析和概括,还应注重对重要的历史概念和历史理论进行阐释和解读,并注意比较教学法的运用。     

World of Work: perceptions of people who are blind or vision impaired

Unemployment and underemployment have, for many years, been a social and economic problem for people with disabilities. This study looks at consumers’ perceptions of access to employment for people who are blind or vision impaired as one target group within the disability field. Using the Employment Access Questionnaire (EAQ), the perceptions of people who are blind or vision impaired were compared with the perceptions of people who are not blind or vision impaired (nondisabled). Results of the study indicated that people who are blind or vision impaired and people who are nondisabled view work as equally important in their lives. However, people who are blind or vision impaired reported that they were significantly less satisfied with career development and services and training opportunities as compared with their peers who were nondisabled. A factor analysis of the data gathered from 85 blind or vision impaired and 84 nondisabled participants revealed a four factor structure for the EAQ. These results are discussed with reference to previous work in this area and suggestions for future research are proposed.     

Health and schooling: evidence and policy implications for developing countries

Health and education are typically viewed as distinct topics from both the research and policy perspectives. Accordingly, the direct interactions between health status and education have been neglected in both research and policy making. The authors use survey data collected from students during the 1980s in Piaui, Ceara, and Pernambuco states as part of an evaluation of a major educational intervention program, EDURURAL, to investigate the complementarities of health with school attainment and cognitive achievement. A series of anthropometric measures for individual students in rural northeast Brazil are used in educational performance models. The promotion models and value-added achievement models both demonstrate the importance of students' visual acuity. Poor vision systematically leads to higher drop-out rates, more grade repetition, and lower achievement. The achievement models also point to the role of good nutrition.     

Developmental changes in the relationship between magnitude acuities and mathematical achievement in elementary school children

The present study examined the developmental change in number and length acuities and their respective relationship with achievement in various domains of mathematics in second vs. fourth graders. Length acuity was measured with a comparison task, in which participants were asked to choose the longer between a pair of lines. Number acuity was measured with a comparison task, in which the participants were asked to choose the more numerous between a pair of dot arrays. Within each grade, length acuity was more precise compared to number acuity. Number acuity was higher in fourth compared to second grade, but length acuity did not differ between grades manifesting a ceiling effect. In second grade, only length acuity was correlated with overall math achievement, especially Geometry and Arithmetic. In fourth grade, only number acuity was correlated with overall mathematical achievement, especially Number Concept and Applied Problems. Taken together, the present study demonstrates that the relationship between magnitude acuities and math achievement dynamically change over the course of elementary school years and that the strength of this relationship may depend on the type of magnitude and the domain of mathematics.     

Improvement in Rapid Reading as Related to Visual Acuity and Initial Reading Speed

Abstract

College freshmen enrolled in a rapid reading course were assigned to one of two groups on the basis of visual acuity. These groups were further divided on the basis of their pretest reading speed. Reading speed and comprehension measures were taken before, after, and periodically throughout the course. Results indicated that the increase in reading speed of the myopic group was significantly greater than that of the emmetropic group and that the group reading initially faster improved at a more rapid rate than did the slower group. Comprehension decreased during the course with the fast readers maintaining better comprehension. By the final measure, reading speed was more related to visual acuity than to the individual’s initial reading speed. The results were interpreted as supporting the contention that myopes are more visually oriented.     

线性啁啾光纤Bragg光栅分段切趾优化

分段切趾是光纤光栅一种新的切趾改进技术。针对线性啁啾光纤Bragg分段切趾的两个重要参数：分段切趾比例和分段切趾强度进行讨论。基于数值模拟的结果,以三分段切趾为例,分析两个参数对光栅性能的影响以及进行优化的方法。     

Visual acuity for single lines as a function of hue and age

176 students in grades 2-12 were tested for visual acuity as a function of minimally resolvable red, yellow, green, and blue lines. A 3-way mixed analysis of variance revealed significant differences among the colors, with better acuity for longer wavelengths. Significant age effects as well as a sex X condition interaction were also found. Post hoc analysis revealed a significant quartic trend for age. It is argued that the differential acuity thresholds for hue and the curvilinear age trend may depend upon the coordination of the accommodation and refractive power of the eye, which are affected by differential growth rates of the lens and the axial length of the eye.     

Assessment of different genetic distances in constructing cotton core subset by genotypic values

One hundred and sixty-eight genotypes of cotton from the same growing region were used as a germplasm group to study the validity of different genetic distances in constructing cotton core subset.Mixed linear model approach was employed to unbiasedly predict genotypic values of 20 traits for eliminating the environmental effect.Six commonly used genetic distances (Euclidean,standardized Euclidean,Mahalanobis,city block,cosine and correlation distances) combining four commonly used hierarchical cluster methods (single distance,complete distance,unweighted pair-group average and Ward's methods) were used in the least distance stepwise sampling (LDSS) method for constructing different core subsets.The analyses of variance (ANOVA) of different evaluating parameters showed that the validities of cosine and correlation distances were inferior to those of Euclidean,standardized Euclidean,Mahalanobis and city block distances.Standardized Euclidean distance was slightly more effective than Euclidean,Mahalanobis and city block distances.The principal analysis validated standardized Euclidean distance in the course of constructing practical core subsets.The covariance matrix of accessions might be ill-conditioned when Mahalanobis distance was used to calculate genetic distance at low sampling percentages,which led to bias in small-sized core subset construction.The standardized Euclidean distance is recommended in core subset construction with LDSS method.     

The development of auditory temporal acuity in children

The development of auditory temporal acuity was studied in 56 children aged 6-12 years and compared with that of 8 adults. Acuity was measured by determining the minimum detectable duration of a brief cessation in a noise band with the 2-alternative forced-choice method. For detection of gaps in a broadband noise, acuity improved significantly with age and reached adult values by 11 years. The minimum detectable duration was significantly shorter at higher levels of the noise. For narrow-band noises, acuity also improved significantly with age and depended on the center frequency of the band. The improvement in temporal acuity with age was attributed to the development of sensory processes and not to age-related changes in nonsensory factors.     

从动物的角色功能看当代电影的生态意识

生态意识中一个重要的视点,是关注人类和其它非人类生命之间的关系。当代中国电影在不同时期对于动物角色功能给予了不同定位。在从阶级叙事到人性叙事的不同叙事模式中,生态意识始终未能浮出地表。生态意识的缺席,既有思想领域、文学领域内生态意识匮乏的间接影响,亦有导演等自身生态视野的缺失的直接因素。而近年来环保电影的出现,在显示差距的同时,亦昭示着新的希望的降临。     

Confucius,Mao and modernization: social studies education in the People's Republic of China

Around the middle years of this century, American progressive educators formulated a vision of general education for the secondary school that would afford all youth common opportunities to integrate and apply knowledge toward the resolution of personal-social problems. This progressive vision of general education was consistent with principles of the US common school ideal and predated the heyday of general education at the college level. This progressive vision of general education can serve today both as a conceptual tool to analyse and as a practical alternative to the national standards movement in the US. This vision of general education also provides common ground for deliberation among reconceptualist-social reconstructionist and progressive-experimentalist curriculum theorists.     

本征砷化镓量子阱的瞬态自旋光栅中电子自旋扩散研究

利用瞬态自旋光栅方法,在室温下实验研究了本征GaAs量子阱中电子自旋扩散的动力学过程.测得了不同周期的瞬态自旋光栅的衰减率,根据普遍认同的公式:Γ=q2Ds+l/τs,计算得到电子自旋扩散系数Ds=104 cm2/s,以及电子自旋弛豫时间τs=46 ps.测得的电子自旋扩散系数与文献报道的N型GaAs量子阱的实验测量结果相吻合,说明样品导电类型对电子自旋扩散系数没有显著影响.而电子自旋弛豫时间τs=46 ps与由饱和吸收方法测得的结果:τs=103 ps有明显区别.进一步分析了自旋光栅调制度随时间的衰减规律,对自旋极化衰减率公式:Γ=q2Ds+l/τs进行了修正.     

均匀光栅中的双模耦合

本文考虑在两模间发生耦合时,均匀光纤光栅的光特性对反射和透射两种情况均得到简单从无论对线形还是非线形的情况,本文所介绍的模耦合理论,对理解有关原理和设计光栅,都是重要的工具。     

Measurement of sugar content in Fuji apples by FT-NIR spectroscopy

INTRODUCTION Recently increasing demands from consumerhave been observed for premium quality fruit witbetter taste at a higher price. Three major parameters determine the internal quality and the tastof apples. These are hardness, sugar content antitratable acidity, which are still determined destructively. Near-infrared spectroscopy (NIRS) habeen used to nondestructively measure internquality in a wide range of fruits and vegetablesuch as onions (Birth et al., 1985), cantaloupe (…     

Infants'' Localization of Sounds within Hemifields: Estimates of Minimum Audible Angle

Infants' acuity in localizing sounds within hemifields was examined by determining the smallest sound shift off 60 degrees and along the horizontal axis that infants could discriminate reliably, that is, minimum audible angle (MAA). Infants 6, 12, and 18 months of age were tested using a Go/No-Go conditioned head-turn procedure in which infants received an equal number of no-change (control) trials and sound-shift (experimental) trials. A correct response (i.e., a head turn toward the loud-speakers) on an experimental trial resulted in visual reinforcement. Localization acuity for sounds within hemifields was fairly poor and improved systematically with increasing age. MAA estimates at each age were significantly higher, indicating poorer localization acuity, in comparison to those obtained previously in research examining infants' resolution of auditory space near midline. These findings are consistent with adult data and demonstrate a finer partitioning of auditory space near midline than within hemifields. The implications of these findings for our understanding of the development of auditory processing mechanisms in sound localization are discussed.