Differences in cerebral activation during perception of optokinetic computer stimuli and video clips of living animals: an fMRI study.

Aims: There is behavioral evidence of increased spontaneous recruitment of visual attention to ancestral evolved categories, such as animals, compared with expertise-derived categories, such as a computer. In order to investigate the association between visual perception and spontaneous visual attention, a study was performed to determine if brain activation whilst viewing moving animals was increased compared with optokinetic computer stimuli.

Methods: Functional MRI was performed in 12 healthy volunteers using a standard block-design paradigm, consisting of three consecutive experiments.

Cycle and gender-specific cerebral activation during a verb generation task using fMRI: comparison of women in different cycle phases, under oral contraception, and men.

Recent observations have revealed some evidence of the influence of sex and menstrual cycle on cognitive functions. In order to examine further differences depending on different phases of menstrual cycle, the use of oral contraception, and gender, fMRI during verb generation tests was performed in 12 female volunteers at menstrual phase and at luteal phase, 12 female volunteers under oral contraception, and in 12 men. Females under oral contraception compared to females in the menstrual or luteal phase revealed superior activation during verb generation in the right hemisphere; compared to menstrual phase in the superior temporal and in the luteal phase in the inferior frontal cortex.

Clinical characteristics of patients with late-onset multiple sclerosis.

We evaluated clinical presentation, cerebrospinal fluid (CSF), and magnetic resonance imaging (MRI) in patients with late-onset multiple sclerosis (LOMS). Fifty-two patients with definitive multiple sclerosis (MS) diagnosed after the age of 50 years were identified between 1991 and 2002. Data pertaining to clinical characteristics, CSF analysis, and cerebral and spinal MRI were compared with those of 52 young-onset MS (YOMS) patients matched for sex and disease duration.

Kinetic modeling of the photosynthetic electron transport chain.

A simulation model of the photosynthetic electron transport chain operating under steady state conditions is presented. The model enables the calculation of (1) the rates of electron transport and transmembrane proton translocation, (2) the proton/electron stoichiometry, (3) the number of electrons stored in the different redox centers and (4) the stationary transmembrane pH difference. Light intensity and proton permeability of the thylakoid membrane are varied in order to compare the predictions of the model with experimental data.