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Biomedical subjects

S Arunachalam

Publications and source records attributed to S Arunachalam.

6 recordsLinked to original sources
PubMed1982

Sublethal effects of carbaryl on surfacing behaviour and food utilization in the air-breathing fish, Macropodus cupanus.

Sublethal effects of carbaryl on surfacing behaviour and food utilization in the obligatory air-breathing fish Macropodus cupanus were studied by rearing the fish individually in freshwater (pesticide-free) and four different sublethal concentrations of carbaryl (1 to 2.5 ppm). M. cupanus exhibited increased surfacing with the increased concentration of carbaryl. Enhanced rate of surfacing may be the result of stress exerted by the toxicant. Food intake of M. cupanus reared in different concentrations of carbaryl did not vary significantly. Growth decreased with increased concentrations of carbaryl, possibly due to excessive expenditure of energy on metabolism that otherwise could have been channelled into fish growth. Frequent surfacing may also account for the expenditure on metabolism. Hence, the conversion efficiency of M. cupanus reared at higher concentrations of carbaryl was poor and was inversely related with higher concentrations of carbaryl.

Animals↗
PubMed1980

Toxic and sublethal effects of carbaryl on a freshwater catfish, Mystus vittatus (Bloch).

The effects of carbaryl (1-naphthalenyl methylcarbamate), commonly used in agricultural operations, have been studied with reference to survival, behavior, food intake, growth, and conversion efficiency of the catfish Mystus vittatus. At a concentration of 32.5 ppm, carbaryl caused 100% mortality within 24 hr; the 72 hr LC50 was 17.5 ppm. At concentrations of 12.5 ppm and below, it caused no mortalities within 72 hr. But such sublethal concentrations accelerated the swimming activity and increased the frequency of opercular beats. The latter response was dose-dependent. These behavioral changes were the immediate response to the toxicant and were indicators of possible stress. A 27-day exposure to sublethal concentrations of carbaryl led to a decrease in feeding rate and growth rate. The latter decreased from 10.15 mg/g/day (freshwater) to 2.84 mg/g/day (12.5 ppm). The reduced growth and conversion efficiency may be due to the expenditure of more energy for the purpose of maintenance. Therefore, the insecticide is considered to be a metabolic stressor.

Animals↗
PubMedDate not supplied

Does India perform medical research in areas where it is most needed?

This paper attempts to map medical research in India and answer an important policy question by literature analysis. I match the disease pattern on the basis of mortality and morbidity statistics with journals used by Indian medical researchers to publish their work as shown by the Science Citation Index (SCI). The former reflects the needs while the latter reflects the areas in which research is being done. The limited statistics available from both the Government of India and the World Health Organization point to diarrhoeal diseases, diseases of children, respiratory diseases, circulatory system diseases, infectious diseases, malaria and tuberculosis as the major medical problems faced by India. The journals used often by Indian medical researchers to publish their work, as seen from the SCI (1981-85), show that in terms of number of publications, they are mainly active in general medicine, pharmacology, tropical medicine, neurosciences, radiology, oncology and pathology. In terms of the share of the world's literature in different subfields, India is second only to USA in andrology, third in tropical medicine after the USA and the UK, tenth in hygiene and public health, and eleventh in general and internal medicine, and radiology and nuclear medicine. Overall, India's share in the medical journal literature is not only much less than that of many other countries, both advanced and middle level, but also much less than that of India's share of the literature in physics, chemistry, mathematics and engineering. Data on the observed citation impact of Indian research in different subfields of medicine show that the work done in India in general is not integrated well into international research. India could be much more purposive in her research priorities and probably should invest much more in medical research.

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