Endemic prevalence of hepatitis B and C in Mongolia: A nationwide survey amongst Mongolian adults.

In this study, a representative group of Mongolian adults was tested for hepatitis B virus (HBV) and hepatitis C virus (HCV). Screening was conducted at 17 different locations on a randomly sampled group, representing the Mongolian adult population. A total of 1158 adults, 500 (43.1%) men and 659 (56.9%) women were included. The prevalence estimates of HBV and HCV amongst the general Mongolian adult population were found to be 11.1%±1% (SE) and 8.5%±0.7% or 207 418 and 160 228 cases, respectively. For HCV, the majority of cases are concentrated in older age groups with a prevalence of 25.8% amongst those aged 50 years and above, whilst the prevalence of HBV does not vary significantly amongst age groups. For both, HBV and HCV, the data indicate a higher risk of infection and a higher mortality because of the hepatitis amongst men than amongst women. This study represents the first nationwide estimate of the prevalence of HBV in Mongolia and also considered the first for HCV since 2005 and confirm the position of Mongolia as one of the hot-spots of chronic hepatitis infection in the world with about 19.4% of the adult population being infected with either HBV or HCV.

Perceptual load interacts with stimulus processing across sensory modalities.

According to perceptual load theory, processing of task-irrelevant stimuli is limited by the perceptual load of a parallel attended task if both the task and the irrelevant stimuli are presented to the same sensory modality. However, it remains a matter of debate whether the same principles apply to cross-sensory perceptual load and, more generally, what form cross-sensory attentional modulation in early perceptual areas takes in humans. Here we addressed these questions using functional magnetic resonance imaging. Participants undertook an auditory one-back working memory task of low or high perceptual load, while concurrently viewing task-irrelevant images at one of three object visibility levels. The processing of the visual and auditory stimuli was measured in the lateral occipital cortex (LOC) and auditory cortex (AC), respectively. Cross-sensory interference with sensory processing was observed in both the LOC and AC, in accordance with previous results of unisensory perceptual load studies. The present neuroimaging results therefore warrant the extension of perceptual load theory from a unisensory to a cross-sensory context: a validation of this cross-sensory interference effect through behavioural measures would consolidate the findings.