fMRI Study of Sentence Generation by Early Bilinguals Differing in Proficiency Level

The aim of this study was to identify the functional anatomy of the cerebral speech regions involved in speaking in native and foreign language in the same subject using functional magnetic resonance imaging.

Experimental design consisted of two activation runs. Each of them included two kinds of tasks arranged in series of five blocks lasting for 30s. In the experimental condition of the first run subjects were required to speak in their native language and in the second run the task was to speak in the foreign language. In both runs, baseline condition was the same and subjects were supposed to lie silently inside the bore. We observed the influence of proficiency on brain activation. In subjects with equal proficiency in the first and the second language, differences were not observed. In the subjects with unequal proficiency in the first and the second language we observed two main effects.

First was difference in the strength and extension of activation, the second effect was activation of new regions for the second language, in which proficiency was lower.

Role of immersion refractometry for investigating laser-induced effects in cells

The broad background of scattered light observed in spectra of cell suspensions is reduced by factors of up to 20 by immersion refractometry allowing for improved spectroscopic determination of the absorption properties of cells in the 325-820 nm range. Refractive-index matched spectra of E. coli C1a exhibit a set of resonant features near 422, 561, and 582 nm. Exposure wavelengths are chosen based on this spectrum and cell viability is investigated in E. coli suspensions exposed to 350, 400, 422, 440, and 700 nm radiation delivered in nanosecond pulses with total doses from 500 millijoules to 60 Joules. We observe a loss in cell viability for doses greater than 1 Joule at 422 nm and for all doses at other wavelengths; exposures of less than 1 Joule at 422 nm enhance growth. Excluding exposures at wavelengths within the resonant feature, longer wavelengths are less effective at reducing the viability of E. coli C1a. This indicates the occurrence of at least two absorption processes.