Asymmetric development of dorsal and ventral attention networks in the human brain

Two neural systems for goal-directed and stimulus-driven attention have been described in the adult human brain; the dorsal attention network (DAN) centered in the frontal eye fields (FEF) and intraparietal sulcus (IPS), and the ventral attention network (VAN) anchored in the temporoparietal junction (TPJ) and ventral frontal cortex (VFC). Little is known regarding the processes governing typical development of these attention networks in the brain. Here we use resting state functional MRI data collected from thirty 7 to 12 year-old children and thirty 18 to 31 year-old adults to examine two key regions of interest from the dorsal and ventral attention networks. We found that for the DAN nodes (IPS and FEF), children showed greater functional connectivity with regions within the network compared with adults, whereas adults showed greater functional connectivity between the FEF and extra-network regions including the posterior cingulate cortex. For the VAN nodes (TPJ and VFC), adults showed greater functional connectivity with regions within the network compared with children. Children showed greater functional connectivity between VFC and nodes of the salience network. This asymmetric pattern of development of attention networks may be a neural signature of the shift from over-representation of bottom-up attention mechanisms to greater top-down attentional capacities with development

Zdolności czyszczące różnych układów płynów w procesie wiercenia przewodem spiralnym

Coiled tubing drilling (CDT) worldwide has grown tremendously in the last decade. In well drilling application gas, foam and liquid (mud) can be used as drilling fluid. The use of a liquid is much simpler and cheaper than the other alternatives and should therefore be considered wherever possible. Using of biopolymer fluid systems is widely accepted. One of the most important fluid system characteristics is hole-cleaning capability, because coiled tubing rotation is not possible. Results of laboratory testing of different fluid systems as well as fluid flow simulation for different geometries of wellbore in term of efficient cuttings transport during coiled tubing drilling are presented in the paper.W ostatniej dekadzie na świecie wzrosło zainteresowanie wierceniami z przewodem spiralnym. W procesie wiercenia jako płuczki wykorzystuje się gaz, pianę i ciecze. To ostatnie zastosowanie jest prostszym i tańszym rozwiązaniem, dlatego możliwość jego użycia należy rozważać w pierwszej kolejności. Powszechnie stosowane są płuczki biopolimerowe. Do najważniejszych parametrów układów płuczkowych należą jej zdolności czyszczące, umożliwiające działanie przewodu spiralnego. W pracy przedstawiono wyniki testów laboratoryjnych wykonanych na różnych układach płuczkowych, jak również symulację przepływu płynu dla różnych geometrii otworu pod kątem zdolności do wynoszenia zwiercin w trakcie wiercenia za pomocą przewodu spiralnego

Dynamic Functional Network Connectivity Reveals Unique and Overlapping Profiles of Insula Subdivisions

The human insular cortex consists of functionally diverse subdivisions that engage during tasks ranging from interoception to cognitive control. The multiplicity of functions subserved by insular subdivisions calls for a nuanced investigation of their functional connectivity profiles. Four insula subdivisions (dorsal anterior, dAI; ventral, VI; posterior, PI; middle, MI) derived using a data-driven approach were subjected to static- and dynamic-functional network connectivity (s-FNC and d-FNC) analyses. Static-FNC analyses replicated previous work demonstrating a cognition-emotion-interoception division of the insula, where the dAI is functionally connected to frontal areas, the VI to limbic areas, and the PI and MI to sensorimotor areas. Dynamic-FNC analyses consisted of k-means clustering of sliding windows to identify variable insula connectivity states. The d-FNC analysis revealed that the most frequently occurring dynamic state mirrored the cognition-emotion-interoception division observed from the s-FNC analysis, with less frequently occurring states showing overlapping and unique subdivision connectivity profiles. In two of the states, all subdivisions exhibited largely overlapping profiles, consisting of subcortical, sensory, motor, and frontal connections. Two other states showed the dAI exhibited a unique connectivity profile compared with other insula subdivisions. Additionally, the dAI exhibited the most variable functional connections across the s-FNC and d-FNC analyses, and was the only subdivision to exhibit dynamic functional connections with regions of the default mode network. These results highlight how a d-FNC approach can capture functional dynamics masked by s-FNC approaches, and reveal dynamic functional connections enabling the functional flexibility of the insula across time