Tools and Techniques in Preparation of Coloured Bones and Skeletons for Effective Teaching, Learning and Museums

Background: Teaching veterinary osteology and arthrology has been performed with free bones collected from various animals after processing and preserving them for long duration. The profession of teaching Anatomy to undergraduate and postgraduate students in veterinary colleges not only requires the knowledge on Veterinary Gross Anatomy but also the methods of preparation of specimen for laboratory use. This article explains the methods and steps in preparation of coloured skulls, bones of forelimb, hindlimb, rib cage, digits and whole mounted skeletons, to be used in the anatomy laboratory to increase the efficiency of both teaching and learning. Methods: A carcass of adult horse donated by a farmer was utilized for making complete coloured skeleton. The bones were collected from the carcass by natural maceration technique followed by cleaning with mild chemicals. The metallic paints and commonly available tools were used for colouring and mounting of horse skeleton. The parts of bones viz. process, fossa, articular area, foramen, the origin and insertion of various muscles were prepared with colours and labels on the surfaces of bones for teaching and museum purpose. The sequential step by step procedure for skeleton preparation in quickest possible time was standardized and explained using various tools. Result: The natural maceration in open water tank was found to be most effective way of maceration of carcasses for collection of bones with their normal colour. The bones were processed mainly with washing soap powder and calcium carbonate followed by drying in natural sunlight which increased the brightness of the bone without any damage to the structure. The coloured skulls, bones of forelimb, hindlimb, rib cage, digits and whole mounted skeletons were prepared with available tools and chemical as this work consumes less time and cost and increases the students’ learning efficiency, which will also be an asset and center of attraction for any Institution.

CHROMATIC DISCRIMINATION THRESHOLDS OBSERVED IN CAM02-UCS AND CAM16-UCS

In our study chromatic discrimination thresholds of normal colour observers measured with the Trivector test of the Cambridge Colour Test were analysed. Chromaticity coordinates were transformed from the CIE (1976) u’v’ diagram to the CAM02-UCS and CAM16-UCS colour spaces, where colour differences were calculated. The measured data consisted of chromatic discrimination thresholds measured in 66 reference points covering the gamut of a CRT display. The test directions were set to the confusion axes towards the Protan, Deutan and Tritan confusion points. Our results show variance in the ΔE values expressed both in the CAM02-UCS and CAM16-UCS colour spaces. Since our input chromaticity values described previously measured just-noticeable stimuli – therefore perceptually equal colour differences – we assumed that our data show equal colour differences in the uniform colour spaces. However, the discrimination thresholds transformed to CAM02-UCS and CAM16-UCS show that colour differences increase towards the chromaticity of the adapting light.

Prototyp eines Bildschirmfarbtests

Purpose. The purpose of this study is to develop a new digital colour vision test. Material and Methods. Based on the principle of metamerism, a digital testing strategy was developed for efficient measurement of colour vision. Twentyfive subjects participated in the study, 21 of whom had normal colour vision and four of whom had a congenital colour vision disorder. Differences in colour vision were examined by monocular presentation of halfquadrants of different hues and degrees of saturation, and the algorithm calculated the colour vision defects that occurred based on the subjects’ responses. The following colour vision values were assigned from the data: a colour scale range of 2.76 – 7.18 for normal colour vision and greater than 7.18 for colour sense disorders. A second new colour scale assessed the type of colour vision disturbance: in the range of 0 – 0.3 were values for a deuteranomaly, in the range of 0.6 – 1.0 were values for a protanomaly, and a value of 1.0 corresponded to a tritanomaly. Results. The difference in colour vision between subjects with normal colour vision and those with a colour vision defect was confirmed (p < 0.001) by measuring the type and the extent of the colour vision disorder was determined. In the group of subjects with normal colour perception, a mean colour scale value of 3.41 ± 0.52 was determined. The extent of colour sense disturbance for the subjects with colour vision impairment was values of 7.18 – 14.33 according to the colour scale, indicating greater variability. Conclusion. The developed algorithm provided meaningful results regarding the colour perception of the test persons. It was possible to differentiate between normal colour vision and colour vision disorder could be shown. Furthermore, the variation between subjects with normal colour vision could be evaluated. Keywords. Colors, colour vision, colour sense disorders, colour test, software algorithm

CRITICAL STUDY OF TVAK IN THE VIEW OF MODERN SCIENCE: A REVIEW ARTICLE

In Ayurveda, the term Tvak, Twacha and Charma are frequently used to denote the skin. Tvak is described as the organ which covers the external surface of the entire body. Tvak and its related diseases have great importance because these are easily noticeable. It is the first part of the body that is in direct contact with any harmful sub- stances or infective microorganisms. It protects the internal structures of the body from injury or infections and regulates the temperature of the body. Skin is also the beauty of a human being. Therefore, it should be protected from any abnormal conditions. Ayurveda Acharyas have described Tvak many years ago. They explained each layer of Tvak in meaningful sequences, its related diseases and measurement of each layer. They also explained that it maintains the normal colour of individuals and conveys the sensation of touch. Some topics of Ayurveda are easy to understand, and some topics become easy if we study along with modern science. So, for a proper un- derstanding of the concept of Tvak, it is very essential to correlate it with modern science and elaborate according to the modern era. Keywords: Tvak, Sparshanendriya, Sharirsthan, Santanika, Vrihi, Skin, Dermis, Epidermis

A Hospital-Based Cross-Sectional Study to Estimate the Prevalence and Sex Distribution of Colour Vision Deficiency among School Going Children Attending a Tertiary Eye Care Center in Kolkata City, West Bengal, India

BACKGROUND Colour vision is a function of three types of cone pigments present in the retina. Colour vision deficiency is an important disorder of vision that may pose a handicap to the performance of an affected individual. The prevalence of colour blindness varies in different geographical areas. The identification and estimation of the prevalence of colour vision deficiency in school-going children will help to educate and guide the caregivers to help the children in selecting their profession. This study was done to estimate the prevalence, sex distribution, and types of colour vision deficiency among school-going children of 5 to 15 years. METHODS A cross-sectional observational study was done among 500 students to evaluate the colour vision during the period from 1st January 2018 to 30th June 2019 at the Regional Institute of Ophthalmology, Kolkata. Ishihara’s pseudo isochromatic colour vision chart 38th edition was used to assess the school children for colour vision status. The children who were found to be colour blind were further classified into degree and types of colour vision deficiency. RESULTS A total of 500 students (250 male & 250 female) of surrounding schools, in the age group of 5 years to 15 years, were screened. 480 students (96 %) had normal colour vision while 20 (4 %) students were found to have defective colour vision. Prevalence (4 %) for colour blindness was found to be higher in males (3.6 %) than females (0.4 %). It was observed that out of 20 (4 %) colour-blind subjects 3.6 % were protanopes and 0.4 % were deuteranopes. CONCLUSIONS The present study shows the prevalence of colour blindness found to be quite low (4 %) and more common in males (3.6 %) in comparison to females (0.4 %). Protanomaly (3.6 %) was more common than deuteranomaly (0.4 %). KEYWORDS Colour Blindness, Protanomaly, Deuteranomaly, School Children

Invasive Aspergillosis of Right Maxillary Sinus with Orbital Extension in an Immunocompetent Individual

Secondary involvement of orbit in aspergillosis following paranasal sinus fungal infection is rare. A case of invasive aspergillosis of right maxillary sinus in a 31-year-old immunocompetent male patient was referred to Ophthalmology OPD with unilateral proptosis. Patient developed proptosis in right eye since six months, which was insidious in onset, progressive, not associated with painful movements. It showed regression since last one month. On examination, best corrected visual acuity was 6/12 in right eye with light projection accurate in all quadrants on presentation, with progressive diminution of vision over 15 days, normal colour vision, pupil was normal in size, reacting to light. Extraocular movements were reduced on lateral side. Left eye examination was within normal limit. Magnetic resonance imaging showed involvement of intra and extraconal compartment upto apex of orbit of right eye, pushing optic nerve medially, with erosion of lamina papyrecea. Intravenous amphotericin B was started and functional endoscopic sinus surgery with maxillary sinus debridement was done. Regular follow-up was kept to prevent the optic nerve involvement.

Modelling and modification of simultaneous lightness contrast effect using the Albers' pattern

Experiments were carried out to investigate the simultaneous lightness contrast effect on a self-luminous display using simultaneous colour matching method. The Albers ' contrast pattern named ' double-crosses ' was used. The goals of this study were to model lightness contrast effect and modify it in the CAM16 colour appearance model. Five coloured targets were studied, and 41 test/background combinations were displayed on a calibrated display. Twenty normal colour vision observers performed colour matching in the experiment. In total, 820 matches were accumulated. The result shows present CAM16 has an unsatisfactory prediction for the effect, especially in the positive region which means the background is brighter than the target. Two models were established based on the visual data, i. e., with and without modification to the lightness difference in CAM16 space. Both of the models predict the effect with high accuracy and reliability.

Clinico-Pathological Profiles and Outcomes of Acute Viral Encephalitis in Children

Background: Encephalitis is an acute inflammatory process that affects brain tissue and is almost always accompanied by inflammation of the adjacent meninges. The disease is most commonly caused by viral infection. Objective: The purpose of the present study was to determine the clinical and cerebrospinal fluid profile of childhood encephalitis and to document Herpes simplex antibody status in cerebrospinal fluid. Methodology: This descriptive analytical study was conducted in Department of Paediatrics of Shaheed Suhrawardy Medical College Hospital and Dhaka Medical College Hospital from May 2011 to October 2011. A total of 30 children of encephalitis were included in this study. Cerebrospinal fluid (CSF) routine and Herpes Simplex virus (HSV) antibody in CSF were done to all patient. Result: Fever and convulsion was found in 29(96.7%) and 28(93.3%) cases respectively in studied patients. Altered level of consciousness was present in 29(96.7%) cases. Fever, convulsion and altered level of consciousness was statistically significant (p<0.05). Glasgow coma scale (GCS) between 4 to 8 was found in 27 (90%) cases. Signs of meningeal irritation and cranial nerve palsies was found in 9 (30%) and 4 (13.3%) cases respectively. Exaggerated deep reflex was found in 23 (76.6%) cases whereas diminished deep reflex was found in 7 (23.3 %) cases. In cytological study of CSF, lymphocyte was found in 28 (93.3%) patients. Raised protein was found in 16(53.3%) and normal in 14 (46.7%) cases. Among the 30 studied cases 9(30%) cases were IgG positive for HSV, 21 (70.0%) were IgG negative and none were IgM positive. Conclusion: Fever, convulsion, altered sensorium and low GCS were common clinical profile in children. Normal colour, increase lymphocyte count, normal sugar level were significant findings in CSF study. Bangladesh Journal of Infectious Diseases 2020;7(1):8-11

Multimodal imaging and adaptive optics in internal limiting membrane dystrophy

An 18-year-old boy presented with a mild blurring of vision in both his eyes for the last 2 years. His best-corrected visual acuity was 20/60 in both the eyes with normal colour vision. Fundus evaluation showed exaggerated shiny reflex from the internal limiting membrane (ILM) with the wrinkled inner retinal surface at posterior pole. No vessel attenuation or retinal pigment epithelium changes were evident. Optical coherence tomography showed thickened ILM, which was appreciated in fundus photo also. The electrodiagnostic tests were normal, and the photoreceptors appeared normal in adaptive optics in the central macula at 2°–4° eccentricity. Among the very few reported cases of Muller cells sheen dystrophy, our patient was the probably the youngest and was picked up by a thoughtful ophthalmologist in detailed clinical examination. Adaptive optics in the case of ILM dystrophy is also not reported earlier.

Colour Preference for Two-Colour Combinations

What determines which colour combinations will be attractive to a person and which will not? Is colour attractiveness only a subjective human experience, or can we predict it based on physical colour parameters? One of the pioneers of the attraction of colour theories was Michel Eugène Chevreul (1786–1889). He distinguished two types of colour harmony – analog colour and contrast – and tried to describe what harmonics are based on physical colour parameters. This was later done by other scientists. Later, semantic evaluation of colours was introduced and factor analysis attempted to identify emotions caused by colours or combinations of colours. The aim of this research is to test whether there is a consistent pattern of judgments of colour combinations under controlled conditions and, if so, to what extent they are influenced by the objective physical characteristics of those combinations. Subjects. The study involved 40 students (20 men, 20 women). All subjects had normal colour vision and were not related to fine art. Research tools. The study used 8 colours: 4 opponent (green, red, yellow and blue) and 4 additional (orange, lettuce, blue and purple). The 28 colour combinations (made up of two different colours) were composed of those 8 colours and printed onto cardboard card where each colour had area of 80 mm x 80 mm. Questionnaire of 40 adjectives consisting of 20 pairs of antonyms were used for semantic colour assessment. Procedure. The investigation was conducted in a dark room. Initially, all 28 cards with colour combinations were placed randomly on a desk lit by a 40 cm high fluorescent lamp (4000K correlated colour temperature). The subject was asked to select one of the cards with the most preferable colour combination, to write its code on the questionnaire and to mark all the epithets in the questionnaire which suits this colour combination. The same procedure was applied to the all other cards. One experiment lasted 35–50 minutes. Results and conclusions. Independent component analysis distinguished 4 dimensions describing colours: pleasure, energy, purple color and strength. Logistic regression analysis was run on colour factor loadings to discriminate colour combinations into two groups: liked and disliked colour combinations. It shows that that colour combination could be predicted as being liked or disliked with 85% probability. Adding physical colour parameters to the regression increases prognostic probability to 92 %. Also a relationship between subjective factors and physical characteristics of colour combinations was found. Pleasure correlates with hue contrast and strength with saturation contrast. It can be argued that the reliability of colour combinations is determined by both subjective and physical factors.