Optical and scanning electron microscopy (SEM) of red blood cells (RBCs) of common carp, Cyprinus carpio, inhabiting a polluted lake in Northeast India revealed a number of abnormalities. About 7% of the RBC showed the presence of a micronucleus, besides the presence of some bi-nucleated and abnormally shaped nuclei. RBCs, white blood cells, and hemoglobin content were found to be reduced significantly as compared to the control. SEM showed the presence of spherocytes, early stages of echinocytes, cytoplasmic blebbing, erythrocytes with contraction from one side, abnormal shape of erythrocytes (hexagonal/pentagonal/tetragonal), development of lobopodial projections, cell rupture, membrane internalization, and formation of ring-shaped RBC. Energy dispersive X-ray spectroscopy (EDS) showed the presence of a considerable percentage of silicon and lead in erythrocytes of the fish collected from the polluted lake, in contrast to a negligible concentration of the two elements in control fish. Significance of the study in relation to fish health in a polluted body of water and the importance of SEM, EDS, and light microscopy in utilizing hematological parameters as pollution indicators are discussed.

This paper presents a computable general equilibrium model of endogenous (stochastic) growth and cycles that can account for two key features of the aggregate data: balanced growth in the long run and business cycles in the short run. The model is built on Schumpeter's idea that economic development is the consequence of the periodic arrival of innovations. There is growth because each subsequent innovation leads to a permanent improvement in the production technology. Cycles arise because innovations trigger a reallocation of resources between production and R&D. The quantitative implications of the calibrated version of our model are very similar to those of Kydland and Prescott's (1982) model. Moreover, under some parameterizations, our model can correct two shortcomings of RBC models: It can account for the persistence in output growth and the asymmetry of growth within the business cycle.