1. The eyes of the crab Carcinus follow with constantly increasing lag the movement of a horizontally rotating (but not a linearly translated) visual field during the slow phase of optokinetic nystagmus. The difference between the eye speed and the drum speed is the effective stimulus for optokinetic nystagmus, and the response bears a constant relation to the stimulus over four orders of magnitude. The lower limit of the response is due to the breakdown of neuromuscular, and not visual mechanism. 2. An overall feedback mechanism exists in which the movement of the eye reduces the apparent movement of the drum. The control of the eye movement is by way of visual cues and proprioceptors play no part. 3. A seeing eye, provided with the appropriate visual stimulus, will drive the other eye if the latter sees no contrasting objects in its visual field or is blinded. Clamping an eye so that it cannot move relative to a stationary, contrasting visual field has the same effect as surrounding the animal with a blank field. 4. The rapid return phase of optokinetic nystagmus also takes no account of proprioceptors, but seems to be triggered when the efferent impulses to the eye muscles reach a definite frequency. Blinding one eye or increasing the drum speed cause a delay of the fast phase. Both eyes flick back simultaneously and the impulses in the oculomotor nerve which cause the slow phase are inhibited during the fast phase. 5. The fast protective retraction of the eye into its socket is a reflex which can be elicited by mechanical stimulation of a single sensory hair. The eyes can retract independently and if retraction occurs during the slow phase of optokinetic nystagmus, the efferent impulses in the oculomotor nerve of the retracting side are centrally suppressed. Peripheral inhibition of the optokinetic response occurs in the retracted eye when it. Is retained in its socket after retraction while the other eye continues with the slow phase of optokinetic nystagmus.7. A comparison reveals similarities in the mechanism causing the onset of the fast phase of optokinetic nystagmus in the crab and in mammals.

Made available in DSpace on 2014-10-09T12:31:19Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:59:32Z (GMT). No. of bitstreams: 1 01411.pdf: 1427457 bytes, checksum: 9115b3894c3a648de77a8f438360c26c (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Made available in DSpace on 2014-10-09T12:37:51Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:08:39Z (GMT). No. of bitstreams: 1 02195.pdf: 1757480 bytes, checksum: 739dc260b2486dfe469bf77fa1698a31 (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Fisica, Universidade de Sao Paulo - IF/USP

No description available.

Made available in DSpace on 2014-10-09T12:31:19Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:59:32Z (GMT). No. of bitstreams: 1 01411.pdf: 1427457 bytes, checksum: 9115b3894c3a648de77a8f438360c26c (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Made available in DSpace on 2014-10-09T12:37:51Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:08:39Z (GMT). No. of bitstreams: 1 02195.pdf: 1757480 bytes, checksum: 739dc260b2486dfe469bf77fa1698a31 (MD5) / Dissertacao (Mestrado) / IPEN/D / Instituto de Fisica, Universidade de Sao Paulo - IF/USP

Light therapy is a general term used for all therapies that utilise different frequencies of light (colours) for therapeutic purposes. The use of light as a healing agent dates back into antiquity to ancient Rome, Greece, China and Egypt, where colour was used in worship and as a healing agent (Leven, 2000). In the year 1892, Niels Finsen of Denmark received the Nobel Prize for successfully treating skin tuberculosis lesions with ultra-violet light. Today, there are many modalities of light therapy of which laser therapy is the best known and researched. The medical profession utilises certain frequencies of light for conditions such as neonatal jaundice, improved healing of surgical wounds, sterilization of blood (externally) and certain types of skin cancer (Liberman, 1991). Extensive research into light and its effects on the human body have given rise to other, not commonly known, forms of light therapy such as Heliotherapy, Spectro-Chrome Therapy, Colourpuncture, Syntonics and the Homoeopathic light and colour remedies. Within this dissertation, the most successful and prevalent light therapies will be discussed in enough detail to give the reader a basic introduction into each modality. The potentially valuable information regarding these healing modalities is widely scattered and therefore effectively out of the reach of the general health practitioner. Bringing this information together in a comprehensive and accessible format would serve to inform health practitioners of the possible alternative therapies available to help prevent/treat disease and deteriorative conditions. The aim of this study is to investigate, compile and organise information regarding the various healing modalities of light and colour therapy, and to determine treatment effectiveness in terms of research and clinical findings. The study aims to create an easily accessible, comprehensive database of pertinent information. Data, pertaining to the different light and colour therapies, will be collected from sources which include books, journals, articles, clinical trials, the internet and lecture notes. The information will be analysed according to the origin, development, application and existing clinical research, if any. From this information the efficacy each therapy can be explored. This information will be written up in the form of a literary survey. Possible outcomes will include increased awareness of therapeutic alternatives to conventional medicine, a more complete and easily accessible information base on each modality, possible inclusion into homoeopathic and allopathic practice, and to stimulate further research. / Dr. Solomon

No description available.

This thesis attempts to justify an intensive course in colour for Fine Arts students at the university and art school. The teaching of colour is justified from a theoretical and a practical standpoint. In the first section, the various disciplines concerned with the subject of colour are examined for evidence of colour's effect on the life of the human organism. This evidence is compiled from reports of research in educational and psychological journals, from the theories en* discussions available in books on the physical and psychophysical evaluation of colour and the physiology and psychology of colour vision. The hypothesis that colour influences man's life pattern is substantiated in this compilation. The phenomenon of colour is not only a significant aspect of man's environment, it is also an element of art. The responsibility for its teaching lies with the art educator. The second hypothesis that the presentation of colour to university and art school students is incompatible with practical needs is supported by an evaluation of contemporary pedagogy of colour in Vancouver. Interviews with teachers of Fine Arts in the Faculties of Arts and Education, The University of British Columbia, in the Vancouver School of Art and the Vancouver Art Gallery revealed that for the most part, the method of teaching colour perpetuates the instructor's own background in colour wheel theory and. the mixture of pigments. Interviews with student colourists, and questionnaires distributed among Fine Arts majors in the Faculty of Education revealed that the theoretical presentation of colour has little application to the practical needs of art students. This thesis concludes with a proposed revision in the approach to colour with students of Fine Arts. The outlined course is designed to develop the ability to manipulate colour through problem-solving experiences. / Education, Faculty of / Graduate

The feature integration theory of object perception (Treisman & Gelade, 1980) suggests that the perception of multidimensional stimuli requires that attention be serially directed to the items in a visual display in order to correctly conjoin features into objects, while the perception of features does not require serial attention. Under conditions in which the serial focusing of attention is disrupted by reducing display duration, available information about conjunctions of two features should not exceed the independent information available about the constituent features. Three experiments using a partial report paradigm employing a location cue were conducted in order to test this prediction. Subjects viewed colored letter displays that varied in cue-display stimulus onset asynchrony. The dependent measure was accuracy of response. Results suggest that a small amount of information from a separate representation of conjunctions of features may be accessible. / Arts, Faculty of / Psychology, Department of / Graduate