Testing Equality of Regressions When Error Variances are Heterogeneous to Study the Production Differentials of Rice in Bangladesh

Method to test the equality of p sets of regression coefficients in presence of heterogeneous error variances is suggested. The sets of regression coefficients are obtained from a sample where the sample observations are classified into p classes. The test statistic to test the significance of the regression is also suggested. As an application of the method, the equality of production functions of boro rice produced in different districts of Bangladesh in two different periods is tested.     

Desmosome and intermediate filament assembly during differentiation and stratification of epithelial cells

In the present investigation the sequential expression and organization of keratin intermediate filament proteins were studied in the developing rat palatal epithelia starting from early gestation period to the adult. The distribution and organization of keratin proteins were correlated with the formation and elaboration of desmosornes during differentiation and stratification of the epithelia.     

Edgeworthin,a new bis-coumarin from Edgeworthia gardneri

Besides daphnoretin and edgeworthin, a new bis-coumarin, was isolated from the stem-bark of Edgeworthia gardneri. Spectral and chemical evidence led to a structure in which two coumarin units are linked by an oxygen bridge between carbons 3 and 7′.     

Attempts to characterize the mechanisms involved in the growth inhibition of Mycobacterium microti in interferon-γ or tumor necrosis factor-α activated J774A.1 cells

Abstract The growth of Mycobacterium microti was inhibited within J774A. 1 macrophage cells activated with either interferon-γ or tumor necrosis factor-α. Activation with interferon-γ or tumor necrosis factor-α alone did not stimulate the production of nitrite in J774A. 1 cells. Interferon-γ but not tumor necrosis factor-a increased the production of hydrogen peroxide in a concentration dependent manner but scavengers of reactive oxygen species did not influence the growth inhibiting effect of interferon-γ within J774A.1 cells. Both interferon-γ and tumor necrosis factor-α enhanced the fusion of M. microti containing phagosomes with lysosomes and the ultimate degradation of bacteria. Our results showed that growth inhibition of M. microti within interferon-γ or tumor necrosis factor-a stimulated J774A. 1 cells was independent of reactive oxygen intermediate and reactive nitrogen intermediate production.     

Effects of mobile phone emissions on human red blood cells

Raman spectroscopy was performed on GSM 900 and 1800 MHz mobile phone signal exposed red blood cells (RBCs). The observed changes in the Raman spectra of mobile signal exposed RBCs compared to unexposed control suggest reduced hemoglobin-oxygen affinity for the exposed cells. The possible mechanism may involve activation of the voltage gated membrane Ca²⁺ channels by the mobile phone emissions resulting in an increase in the levels of adenosine triphosphate (ATP) and 2,3-diphosphoglycerate (2,3-DPG) in cells via altered metabolic activities. Further studies carried out with fluorescent Ca²⁺ indicator confirmed increased intracellular Ca²⁺ level in the exposed cells. Since intracellular ATP level influences the shape and mechanics of RBCs, exposed cells were studied using diffraction phase microscopy and optical tweezers. Detectable changes in shape and mechanical properties were observed due to mobile signal exposure.     

Protein kinase activity in mouse mammary carcinoma.

C3H mouse mammary carcinoma contains cyclic AMP-independent (C) and dependent (RC) protein kinases and a specific cyclic AMP-binding protein (R). The specific activities of C, RC and R are markedly lower in carcinoma than the normal mammary cells. Protein kinase preparation from neoplastic cells showed markedly higher ration of $\text{C}\text{RC}$ and lower responsiveness to cyclic AMP for the activation of the enzyme than the normal cells.