bluuebunny/crossref_metadata_2025_split huggingface dataset:
De l’artefact à la naissance de l’instrument pour la maîtrise de la consommation d’électricité : approche ergo-sociologique de la genèse instrumentale des smart‑grids
Authors: Lassalle Julie , Amelot Adélaïde , Chauvin Christine , Boutet-Diéye Annabelle 
Published: October 2016

Dans un contexte actuel marqué par des enjeux de développement durable, notamment d’efficacité énergétique, le déploiement programmé des réseaux électriques communicants (smart-grids) doit apporter des possibilités d’action nouvelles pour l’usager en matière de maîtrise de sa consommation d’électricité (MCE). La présente contribution s’intéresse à la manière dont la technologie smart-grid s’élabore comme une ressource pour l’activité de MCE. L’analyse de l’appropriation de ces nouvelles technologies est centrale et déterminante pour comprendre quels peuvent être les freins et les leviers au développement de leurs usages et de l’activité de MCE. L’approche ergo-sociologique présentée propose d’étudier ce processus sous l’angle de la genèse instrumentale, c’est-à-dire du passage du statut d’artefact de la technologie introduite à celui d’instrument pour l’activité de MCE. L’articulation ergo-sociologique (entre la théorie instrumentale, l’approche du processus d’appropriation issue de la sociologie des usages et la théorie de l’acteur-réseau) offre une vision élargie de cette genèse à partir de trois niveaux de focale : (i) micro, basé sur l’étude de l’activité médiatisée et l’élaboration de ressources pour et dans l’activité ; (ii) méso, reposant sur l’étude des pratiques sociales comme berceau de l’activité médiatisée et ; (iii) macro, s’intéressant aux interactions entre actants du réseau socio-technique dans lequel l’activité médiatisée s’inscrit.
Penser et concevoir pour le développement du sujet tout au long de la vie : de l’enfant dans sa vie quotidienne à l’adulte en situation de travail
Authors: Decortis Françoise , Bationo-Tillon Anne , Cuvelier Lucie 
Published: October 2016

Cet article vise à mettre en évidence les questions et critères incontournables dans une perspective de conception pour le développement en nous appuyant sur des recherches menées du côté de l’ergonomie orientée enfant (Decortis, 2015a). Deux cadres théoriques sont plus particulièrement convoqués, l’approche instrumentale (Rabardel, 1995) et le cycle de l’activité créative de l’imagination (Vygotski, 2010), par le biais du modèle NAM (Decortis, 2013, 2015b), pour étudier la conception d’artefacts technologiques. Puis, nous discutons ces questions en regard des situations plus classiquement étudiées en ergonomie pour mettre en perspective les apports fructueux de l’ergonomie orientée enfant dans le champ des situations de travail et de la formation professionnelle.
Dark refraction shift with allowance for astigmatism
Authors: Gillan W.D.H. 
Published: October 2016

Purpose: To show that the dark refraction shift (dark focus) is a more complicated phenomenon than implied when presented as spherical. Methods: Fifty autorefractor measurements of refractive state of the right eye were obtained in light and dark conditions. Multivariate methods were used to analyze the data and stereo-pair scat-ter plots, polar meridional profiles and other means of presenting results are used to show important characteristics of the dark refraction shift. Results: The complexity of the dark refrac-tion shift is indicated by stereo-pair scatter plots showing the amount of stigmatic and antistigmatic variation that occurs in light and dark conditions. The mean dark refraction shift is presented in a complete manner including all three components of refractive state. The greater variance and covari-ance under dark conditions is clearly shown by the term-by-term dark-light variance-covariance ratio and polar profiles of variance and covariance.Conclusions: The dark refraction shift is a more complicated phenomenon than implied by representations as purely spherical in nature.
The concept of the average eye
Authors: Van Gool R.D. 
Published: October 2016

For most quantitative studies one needs to calculate an average. In the case of refraction an average is readily computed as the arithmetic average of dioptric power matrices. Refraction, however, is only one aspect of the first-order optical character of an eye. The question is: How does one determine an average that rep-resents the average optical character of a set of eyes completely to first order? The exponen-tial-mean-log transference has been proposed recently but it is not without its difficulties. There are four matrices, naturally related to the transference and called the characteristics or characteristic matrices, whose mathematical features suggest that they may provide alterna-tive solutions to the problem of the average eye. Accordingly the purpose of this paper is to propose averages based on these characteristics, to examine their nature and to calculate and compare them in the case of a particular sample of 30 eyes. The eyes may be stigmatic or astig-matic and component elements may be centred or decentred. None turns out to be a perfect average. One of the four averages (that based on one of the two mixed characteristics) is proba-bly of little or no use in the context of eyes. The other three, particularly the point-characteristic average, seem to be potentially useful.
Prevalence and causes of low vision and blindness worldwide
Authors: Oduntan A.O . 
Published: October 2016

A recent review of the causes and prevalence of low vision and blindness world wide is lack-ing. Such review is important for highlighting the causes and prevalence of visual impairment in the different parts of the world. Also, it is important in providing information on the types and magnitude of eye care programs needed in different parts of the world. In this article, the causes and prevalence of low vision and blind-ness in different parts of the world are reviewed and the socio-economic and psychological implications are briefly discussed. The review is based on an extensive review of the litera-ture using computer data bases combined with review of available national, regional and inter-national journals. Low vision and blindness are more prevalent in the developing countries than in the developed ones. Generally, the causes and prevalence of the conditions vary widely in different parts of the world and even within the same country. World wide, cataract is the most common cause of blindness and low vision among adults and elderly. Infectious diseases such as trachoma and onchocerciasis result-ing in low vision and blindness are peculiar to Africa, Asia and South America. Hereditary and congenital conditions are the most common causes of low vision and blindness among chil-dren worldwide.
The log-transference and an average Gaussian eye
Authors: Harris W.F. 
Published: October 2016

Recent research on the logarithm of matrices is likely to have a signiﬁcant impact on optom-etry. The purpose of this paper is to draw atten-tion to this research and show application to the calculation of an average centred Gaussian eye in particular. The paper makes use of Cardoso’s method to obtain an explicit expression for the logarithm of a transference. The arithmetic aver-age of log-transferences leads to a transference which can be regarded as the transference of the average eye for the set. A numerical example is presented.
Fundamentals of colour awareness: a literature review
Authors: Rubin A. 
Published: October 2016

A description of some of the basic or funda-mental aspects of the colour sensory mechanism will be provided here, based on modern ideas and literature, with reference speciﬁcally to the likely origins and evolution of colour vision. The mo-lecular basis for colour awareness and the human colour pathway will also be considered in some detail. This paper intends to provide the theoreti-cal and philosophical basis for further papers that will introduce a modern and original computer- based method for more comprehensive colour vision assessment. This new approach, to be fully described in later manuscripts, may contrib-ute towards improvements in understanding and knowledge of human colour perception and its measurement, still perhaps a relatively under-ex-plored or neglected ﬁeld of study within optom-etry and ophthalmology.
Application of multivariate analysis of vari-ance (MANOVA) to distance refractive vari-ability and mean distance refractive state
Authors: Abelman S 
Published: October 2016

Refractive state can be regarded as a dynam-ic quantity. Multiple measurements of refractive state can be determined easily and rapidly on a number of different occasions using an autore-fractor. In an experimental trial undertaken by Gillan, a 30-year-old female was subjected to 30 autorefractor measurements each taken at vari-ous intervals before and after the instillation of Mydriacyl 1% (tropicamide) into her right eye. The purpose of this paper is to apply multivar-iate analysis of variance (MANOVA) to Gillan’s sample data in order to assess whether instillation of Mydriacyl into the eye affects variability of distance refractive state as well as mean distance refractive state as measured by an autorefractor. In five of the seven cases where pairwise hypotheses tests were performed, it is con-cluded that at a 99% level of confidence there is no difference in variability of distance refrac-tive state before and after cycloplegia. In two of the three cases where MANOVA was applied, there is a significant difference at a 95% and at a 99% level of confidence in both variability of distance refractive state and mean distance refractive state with and without cycloplegia.
A comparison of the effect of reduced illumination and tinted lenses on stereospsis at near
Authors: Mehta M. , Ramkissoon P. , Bhagwanjee A. M. 
Published: October 2016

Relative depth may be appreciated with the use of one eye using linear perspective, shadows, parallax and texture as monocular cues to depth. Stereopsis, on the other hand, is the directappreciation of relative depth that requires the use of both eyes to construct a three-dimension-al percept from disparate two-dimensional retinal images. The advantage of stereopsis is with respect to complex visual tasks especially that requiring accurate hand-eye coordination. Tinted lenses are prescribed for a variety of reasons, including but not limited to photophobia, asthenopia, improving colour perception in colour deﬁcient individuals, enhancing cosmesis and protection against glare or harmful radiation and enhancing visual performance as in sports. The aim of this study was to investigate the comparative effects of six speciﬁc CR39 tinted spectacle lenses (grade B), and a white CR39 lens, against a no lens condition, on stereoacuity over a range of illumination levels. Illumination was varied with the use of neutral density (ND) ﬁlters, while the Titmus Fly Stereotest (TFS) wasused to measure stereoacuity. Participants (n =60) between the ages of 17 - 29 years (mean =23.58; sd = 3.14) were purposively sampled from a clinical practice to participate in this research study. Using repeated measures ANOVA and appropriate post-hoc multivariate analysis, it was evident that there was a signiﬁcant decline in stereopsis as the level ofillumination decreased,regardless of tint condition; also there was no statistically signiﬁcant difference in stereopsis between the no lens and white lens conditions at each level of illumination; and stereopsis wassigniﬁcantly superior with the no lens conditioncompared to all six other tint conditions (gradeB), at each level of illumination. These results indicate that stereoacuity, as measured by the TFS, is adversely affected by adecline in retinal illuminance and by the use of tinted lenses. This information could be utilised to advise patients on the performance implications of the six tinted lenses tested with respectto their effects on stereoacuity under different illumination levels.
Quantitative analysis of transformed ray transferences of optical systems in a space of augmented Hamiltonian matrices*
Authors: Harris W. F. 
Published: October 2016

There is a need for methods for quantitative analysis of the first-order optical character of optical systems including the eye and components of the eye. Because of their symplectic nature ray transferences themselves are not closed under addition and multiplication by ascalar and, hence, are not amenable to conventional quantitative analysis such as the calculation of an arithmetic mean. However transferences can be transformed into augmented Hamiltonian matrices which are amenable to such analysis. This paper provides a general methodology and in particular shows how to calculate means and variance-covariances representing the first-order optical character of optical systems. The systems may be astigmatic and may have decentred elements. An accompanying paper shows application to the cornea of the human eye with allowance for thickness.
Introducing low vision care into the Government eye care services in South Africa
Authors: Oduntan A. O. 
Published: October 2016

There are many visually impaired people all over the world including South Africa, unfortunately, vision rehabilitation services are lacking in many countries. Currently in South Africa, low vision care is offered by a few private optometric practitioners, optometric institutions and non-governmental organizations. Although most of the major Government hospitals in the country provide ophthalmological services to patients, only a few of these provide optometric services and none provides low vision care services yet. There is therefore, a great need to increase vision rehabilitation services in the country. There are plans to introduce optometry sections into government hospitals in every Province of South Africa and these plans include introduction of low vision care as part of the optometric services. There is, therefore a need for information on how to introduce low vision care services into existing optometry facilities in the Government hospitals and those that may be established in the future. The purpose of the article is to discuss how low vision services can be introduced into public eye care facilities. Issues relating to rehabilitation of visually impaired patients, low vision care, infrastructure, equipment, low vision devices and human resources are discussed in this paper. To justify the facility needs, basic information on assessment procedure of low vision patients is included. Also, names and contact details of a few companies supplying low vision devices in South Africa are provided. The contents of this article will be useful to health care managers in the government hospitals; especially those in charge of the optometry services as well as the optometrists who may wish to work in the low vision care sections in Government hospitals.
Oculo-visual status of the welders in the Capricorn District of the Limpopo Province of South Africa*
Authors: Sithole H. L. , Oduntan O. A. , Oriowo M. O. 
Published: October 2016

The process of welding can lead to several ocular disorders when adequate protective precautions are not taken. There is a possibility that welders in the Limpopo Province of South Africa are not taking adequate precautions due to lack of knowledge on the adverse effects of welding. Good vision is also important for effective and injury-free welding. This study therefore screened welders in the Capricorn district of the Limpopo Province for oculo-visual disorders. Case history established visual symptoms among the welders and ophthalmic tests such as visual acuity (VA) measurement, pinhole, ophthalmoscopy, external assessment of the adnexa and Amsler grid were used to determine their oculo-visual status. One hundred and fifty welders were included in the study and their ages ranged from 18 to 65 years with a mean of 39 ± 14.9 years. Reduced distance vision was reported by 32% of the welders, 14% reported reduced vision at near; 43% reported double vision and 11% reported colour vision anomaly. Forty seven percent of the welders had VA less than 6/6 at distanceand 8% could only read 1M or larger print at near Following the pinhole test, there was no improvement in 7% of the welders who had VA less than 6/6, indicating a possibility of pathological conditions. Amsler grid showed that 6% of the welders had possible macular disorders. Ophthalmoscopy and external observations revealed that 7% of the welders had cup disc ratio (H/V) of more than 0.6/0.5, Fourteen percentage (14%) had pterygia and 5% had pinguecula. The study established that although many of the welders had normal oculo visual status, there were a few with ocular disorders which warrant further assessment and managemenby eye care professionals.
Short-term variation of central corneal thickness and axial anterior chamber depth of healthy eyes using Scheimpflug photography via the Oculus Pentacam*
Authors: Mathebula S. D. 
Published: October 2016

The purpose of this study was to investigate short-term variation and intra-subject repeatabil-ity of human central corneal thickness (CCT) and axial anterior chamber depth (AACD) measure-ments obtained using the Oculus Pentacam. Forty consecutive images of the right eye of the anteriorsegment of 10 young and healthy individuals were measured with the Pentacam. Measurements of CCT and AACD were ob-tained from these images and means, standard deviations,variances and repeatability of the measurements were investigated. Both parameters (CCTand AACD) showed small variation with good orexcellent repeatability for all eyes. The inter-subject or overall means and standard deviations for CCT and AACD of the 10 right eyes were 0.555 ±0.05 millimeters (or 555 ± 50 microns) and 3.206± 0.04 millimeters, respectively. The individual or intra-subject averages for samples of CCT and AACD measurements are also provided in this paper. Univariate normality of the data was explored with Kolmogorov-Smirnov, Lilliefors and ShapiroWilks tests and we found that generally the data was normally distributed although there were some exceptions. Based on the results of this study, the Oculus Pentacam appears to provide repeatable and reliable measures for both CCT and AACD in young,normal eyes. Further research is, however, needed to determine short-term variation and repeatability of CCT and AACD with the Pentacam in more com-plicated eyes with, say, corneal scarring or ectasia or where refractive surgery may be an issue.
South African university student knowledge of eye protection against sunlight
Authors: Oduntan O. A. , Carelson A. , Clarke-Farr P. , Hansraj R. 
Published: October 2016

Exposure to sunlight has been associated with several ocular conditions such as cataract, age-related macular degeneration, and conjunctival neoplasm. Knowledge of protective modalities and good behavioural practice involving eye protection is essential to prevent adverse effects of sunlight. The purpose of this study was to establish knowledge amongst randomly selected university students in South Africa, of prevention modalities against the adverse effects of sunlight. A questionnaire relating to the knowledge of preventive modalities was completed by randomly selected students from four universities selected by convenience sampling. Questionnaires completed by one thousand, eighthundred and thirty two (N =1832) subjects were analysed with descriptive statistics using Stata version 10. The participants’ ages ranged from 17 to 55 years (mean = 21.03 ± 3.4 years). They included 43.7% males and 56.3% females. They were 68.3% Blacks, 20.0% Whites, 3.4% Indians and 7.4% Coloureds. Many (82.3%) of them knew that excessive exposure to sunlight can adversely affect the eyes. Only 28.5% reported that they often wore sunglasses outdoors. Only 38.5% of the participants knew that not all spectacles or contact lenses could protect eyes from ultraviolet radiation. However, many, 87.7% and 69.5% respectively knew that sunglasses and spectacles could be specifically designed to block UVR from entering the eye. Just over half (52.7%) knew that contact lenses can be specifically designed to block the UVR. Many, (68.4%) agreed that wearing hats with brims could protect the eyes against harmful radiation from the sun and the majority, 95.8% agreed that there was a need for awareness campaigns about the effects of the sun on the eye and against excessive exposure. Female respondents had more knowledge of preventive modalities than the males. Knowledge of preventive modalities among the respondents varied significantly with the type of questions and was poor for certain questions. This suggests a need for an eye protection awareness campaign amongst the general population in South Africa, about the possible adverse effects of sunlight on the eye and appropriate protective practices.
The effects of visual skills on Rhythmic Gymnastics*
Authors: Potgieter K. , Ferreira J. T. 
Published: October 2016

Vision plays an important role in all sports, but has often been neglected when evaluating the performance of athletes. Rhythmic Gymnastics is a dynamic and compelling sport for girls that challenge body and mind. It is a relatively new Olympic sport that requires performance according to a set standard. The goals of this study were to identify the visual skills important to rhythmic gymnasts and to explore whether these skills could be improved by means of an intervention programme. This study further aims to provide sport specific visual performance standards to the gymnasts. Little research is available connecting vision to this sport and it was seen as a good opportunity to make a difference. After testing the visual skills of a sample of 62 rhythmic gymnasts (divided randomly into two comparable groups of 32 for the experimental group and 30 for control group) the experimental groupfollowed a sports specific intervention programme while the control group adhered to their regular training schedule. The visual skills trained by the intervention programme were re-tested on both the experimental and control groups of gymnasts. The results obtained from the post-intervention meas-urements were analyzed and compared to the original data obtained from the pre-intervention measurements of both the groups of gymnasts. Results from competitions were obtained and compared to establish the effect of the intervention programme. It is concluded that the software skills of the visual system plays an important role in the sport of rhythmic gymnastics. These skills can be improved by implementing a sustainable visual training programme for the training of rhythmic gymnasts.
General approach to the sensitivity of the optics of an eye to change in elementary parameters with application to the Gaussian optics of a reduced eye
Authors: Harris W. F. 
Published: October 2016

Optical properties of the eye, including the refractive compensation, for example, may change if there are changes in any of the components that make up the eye. The sensitivity to such changes isquantified via the derivative. This paper employs the reduced eye and Gaussian optics to illustrate a general method for the analysis of sensitivity in eyes. The method requires a clear statement of the dependent variable as a function of independent variables. A symbolism is offered that makes the function unambiguous. Sensitivities are determined for the fundamental optical properties,the transference and the corneal-plane refractivecompensation of a reduced eye to change in corneal power, curvature and radius of curvature and to change in axial length and index of refraction. Emsley’s reduced eye is examined in particular. Its corneal-plane refractive compensation has a sensitivity of 135 −135 D to change in refractive index, 1 −2.7 D/mm to change in length and 135 −1/3 to change in corneal curvature when the other two independent variables are held fixed. The method has the potential to develop guidelines that are useful clini-cally.