ABSTRACT
Earthworm population dynamics was studied in two agroforestry systems in the tropical hilly terrain of Mizoram, north-east India, over a period of 24 months, from July 2002 to June 2004. Two sites of agroforestry situated at Sakawrtuichhun (SKT) and Pachhunga University College (PUC) campus, Aizawl, having pineapple as the main crop, were selected for detail studies on population dynamics. Five of the total twelve species of earthworm reported from the state were recorded in the study sites. The density of earthworm ranged from 6 to 243 ind.m-2 and biomass from 3.2 - 677.64 g.m-2 in SKT. Comparatively the density and biomass in PUC, which is at relatively higher altitude were lower with a range of 0 to 176 ind.m-2 and biomass from 0 - 391.36 g.m-2 respectively. Population dynamics of earthworm was significantly correlated with rainfall and physical characters of the soil. Earthworm biomass was significantly affected by rainfall and moisture content of the soil. The influence of chemical factors was relatively less.
ABSTRACT
Effect of chronic environmental tobacco smoke (ETS) exposure on bronchial responsiveness (BR) was assessed by the measurement of BR in stable, nonsmoker asthmatic women and comparison of the PD20 in the exposed and non exposed groups was also studied. Nonspecific bronchoprovocation test was performed by histamine inhalational challenge. Of fifty patients included in the study, 23 (46%) had history of ETS exposure of 1.22 (+/- 0.61) hours per day for an average of 13.07 (+/- 6.1) years. The PD20 was significantly lower in the ETS exposed group (p < 0.05). When the subjects were compared, based on their cumulative exposure expressed by an exposure index (El = duration of exposure in years multiplied by average number of hours per day), there was a statistically significant difference in PD20 of those with El of less than those with El of more than 15. It is concluded that BR is greater, and reflects the higher morbidity in the ETS exposed patients of asthma.