Search

The default mode network (DMN), based in ventromedial prefrontal cortex (vmPFC) and posterior cingulate cortex (PCC), exhibits higher metabolic activity at rest than during performance of externally oriented cognitive tasks. Recent studies have suggested that competitive relationships between the DMN and various task-positive networks involved in task performance are intrinsically represented in the brain in the form of strong negative correlations (anticorrelations) between spontaneous fluctuations in these networks. Most neuroimaging studies characterize the DMN as a homogenous network, thus few have examined the differential contributions of DMN components to such competitive relationships. Here, we examined functional differentiation within the DMN, with an emphasis on understanding competitive relationships between this and other networks. We used a seed correlation approach on resting-state data to assess differences in functional connectivity between these two regions and their anticorrelated networks. While the positively correlated networks for the vmPFC and PCC seeds largely overlapped, the anticorrelated networks for each showed striking differences. Activity in vmPFC negatively predicted activity in parietal visual spatial and temporal attention networks, whereas activity in PCC negatively predicted activity in prefrontal-based motor control circuits. Granger causality analyses suggest that vmPFC and PCC exert greater influence on their anticorrelated networks than the other way around, suggesting that these two default mode nodes may directly modulate activity in task-positive networks. Thus, the two major nodes comprising the DMN are differentiated with respect to the specific brain systems with which they interact, suggesting greater heterogeneity within this network than is commonly appreciated. Hum Brain Mapp, 2009. © 2008 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

To compare the management of paediatric patients with mild or moderate asthma in paediatric-only emergency departments (POEDs) to treatment in a mixed adult-child emergency departments (mixed EDs). Prospective, observational study conducted in 36 Australian emergency departments (EDs) for 2 weeks in 2001. Children aged 1−15 years with acute asthma classified as mild or moderate severity. Details of demography, severity assessment, and type of treatment facility, treatment and disposition were collected. Analysis used descriptive statistics, comparison of proportions by χ2, and multiple logistic regression. Two-hundred and nine children were treated at POEDs and 257 at mixed EDs. The groups had similar severity. Spacers to deliver beta-agonists were used more frequently in POEDs (67.5% vs 24.2%; P < 0.01). Children treated at POEDs with a mild attack were more likely to be admitted (20.6% vs 9.5%; P < 0.02) and given salbutamol (82.8% vs 71.9%; P = 0.03). For children with moderate asthma, oral steroid prescription on hospital discharge was more common for those treated in a mixed ED (81.0% v 95.7%; P = 0.01). Ipratropium bromide (IB) was widely used at both types of ED but more commonly used in mixed EDs (41.7% vs 54.9%; P < 0.01). There were no differences in length-of-stay, representation rate within one month and oral steroid use for attack. Less than 2/3 of children with mild asthma attacks received steroid treatment in the ED. Treatment was similar between the two types of ED. IB was overused in mild asthma and oral steroids were underused in moderate asthma, by both ED types. Spacers were under-utilized in mixed EDs. [ABSTRACT FROM AUTHOR]

Comments on other articles about Alexander Bogdanov in this issue of `Russian Review.' Scholarship on Bogdanov is divided; Tangle of contradictions; Two lines of consistency: Lenin's political practice and Bogdanov's philosophy; Disagreement withJohn Eric Marot; More.

A letter to the editor is presented in response to the article "Anticipatory and Reactive Responses to Chocolate Restriction in Frequent Chocolate Consumers" by C. L. Keeler and colleagues published in the journal in 2015.