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Biomedical subjects

R N Sen

Publications and source records attributed to R N Sen.

At least 19 recordsLinked to original sources
PubMed1984

Bishnupur achromats and their relatives (an exploratory study with six colour vision tests).

Thirteen subjects from the 'Sankhabaniks' of Bishnupur and two new similar cases were given six colour vision tests. All had photophobia, fixation nystagmus, low visual acuity and marked, though not complete, loss of colour sense. Forty other males and 24 females related to the defectives were also tested with at least five of the tests, for comparison. The tests were Ishihara, HRR test, Sloan's Achromatopsia test, the Dichotomous (D 15) test, Hundred Hue test and the Pickford-Nicolson Anomaloscope. The present research confirmed the provisional conclusion of Bose et al. (1968) that the achromatopsia in Bishnupur is an autosomal recessive character. That women relatives of the achromats showed greater average error scores with the Dichotomous test, the Hundred Hue test and the Sloan's test than male relatives, suggests that the defect is more readily manifested in males, and that the female relatives would include a number of genetic defectives with incomplete manifestation due to sex control. The defectives were clearly distinguished from the relatives as a group.

Adult↗
PubMed1979

Colour vision tests and colour naming by thirteen incomplete achromats in Bishnupur.

As an exploratory study six colour vision tests were given to nine male and two female achromats from the Shankhabanik community in Bishnupur, and to two additional similar males. All thirteen subjects had severe photophobia, fixation nystagmus, extreme weakness of vision (4/24 to 3/60) and the red end of the spectrum was much shortened. This research indicates that they had a form of incomplete achromatopsia, varying from an almost complete to a very severe partial loss of colour vision. The condition is inherited as an autosomal recessive. The most likely interpretation of these cases is that they are incomplete rod achromats. Their performance on the colour vision tests is tabulated, and shows complete inability to do the Ishihara test; nearly complete inability on the HRR test, with a possible slight tendency to do better in the yellow-blue than the red-green sub-tests; on Sloan's test they show approximate accordance with her results for achromats; they have severe difficulty with the dichotomous and 100-hue tests, with a possible slight tendency to make fewer errors on the G/B sections. The anomaloscope shows little abnormality of mid-matching points, but great increases in average matching ranges above the normal, although not absolute loss of colour sense, but with extreme darkening or shortening of the red end of the spectrum. Their colour naming was carefully recorded, and was fairly good occasionally, sometimes erroneous without being wildly at fault, and most often completely wrong. The records of colour naming were made, not, of course, as a form of colour vision test, but simply to illustrate the ways in which such defectives make an effort to use colour names in general use among their friends and relatives.

Adult↗
PubMed1978

Optimal rate of work for mountaineers.

The physiological responses of seven young male highlanders were recorded at high altitude while they were carrying loads (0, 25, 35, 45, and 55 kg) on snow at different speeds, supporting the loads on their backs by circular straps around the forehead. The rates of work calculated from the gross weight (body weight plus actual load in kg) multiplied by the speed of walking, m.min-1, ranged from 4,460 to 8,440 kg.m.min-1. The relationship between the rate of work and energy expenditure was rectilinear within the present range of values. The oxygen consumption (51.6 and 59.7 ml.min-1.kg-1 BW) for 55-kg load (at 4.09 and 4.64 km.h-1) possibly reached maximal aerobic capacity. At higher energy output at high altitude the subjects were exhausted after a short period of work. The proportion of increase of oxygen consumption per kg gross weight carried or per kg.m was almost constant up to a 55-kg experimental load. It is suggested that for day-to-day operations work should not be undertaken at more than 30-40% of maximal work capacity; a rate of work around 4,000 kg.m.min-1 (25-30 kg actual load at 3.0 to 3.5 km.h-1) may be considered as optimal for highlanders and porters at high altitude.

Adaptation, Physiological↗
PubMed1978

Incomplete achromatopsia in Bishnupur.

Nine males and 2 females from the Shankhabanik Community in Bishnupur, provisionally diagnosed as incomplete rod achromats by Bose, Joardar and Sukul in 1968, with 2 new similar males, were tested more fully with six colour vision tests. All had photophobia, nystagmus of fixation, extremely low visual acuity and extreme loss of colour sense with shortened red spectrum. 40 other males and 24 females, relatives of the defectives, were also tested for comparison. The provisional diagnosis was confirmed, and the hypothesis of autosomal inheritance seemed most probably true. Various details about the relatives emerged.

Color Vision Defects↗
PubMed1978

Circadian rhythms in some groups of Indians working in shifts.

The present study was undertaken in order to find out the effect of changes of shifts on different physiological responses in Indian industrial workers. Two groups, one of 8 workers from industries and another of 6 sedentary subjects used as controls, acted as volunteers in this study. The first group worked in three different shift rotations: morning, afternoon and night. The second group worked in two shifts: day and night only. Different physiological responses, specially the pulse rate and oral temperature, were recorded hourly. The other physiological responses, such as frequency of micturition, gastro-intestinal disturbances, hours of sleep were also noted. Several days of consecutive work and recreational activities were considered in each subject. In the control group, the oral temperature rhythm did not change significantly with the change of shifts; so did the pulse rate rhythm. But this group had less sleep and higher frequency of micturition in the night shift routine than those during day shift. The typical industrial workers' oral temperature rhythm also did not change significantly with the shift changes, but their pulse rate rhythm changed slightly with shift change, possibly in an attempt to adapt. They generally slept well in all 3 shifts and had micturition equally frequent. However, there were individual variations with some peculiarities in both the groups.

Acclimatization↗
PubMed1975

Work organization of heavy load handling in India.

The physical work rate, the energy and the cardiac costs of twenty-seven young male workers from the eastern part of India in five groups handling loads of about 30, 60, 75, 90, and 125 kg, respectively, were ascertained with the objective to rationalize the rate of work based on the physiological responses of the workers. The mean rate of usual work of the groups (I to V) was 4,715, 8,020, 7,350, 6,100, and 7,600 kg-m/min, respectively, which was considered to be extremely heavy. From the mean values of all the groups for the average work pulse rate of 143.1 beats/min, the recovery-pulse-sum of 119 beats for the first five minutes of recovery, the first and third minute recovery pulses of 127 and 114, respectively, the oxygen-pulse of 0.25 ml/pulse/kg, and the energy cost of 9.1 kcal/min, it was suggested that excepting the first group, the workers were working at a level much higher than the 50% level of their maximal working capacity. The simple and multiple linear correlation coefficients between the rate of work and the various physiological parameters were significant and different linear regression equations were suggested. In conclusion, for extremely heavy types of work in India, 1,200 kcal as the net optimal energy output in an 8-hr working day is suggested.

Adult↗