Search

Much remains unknown regarding the relationship between anxiety, worry, sustained attention, and frontal function. Here, we addressed this using a sustained attention task adapted for functional magnetic resonance imaging. Participants responded to presentation of simple stimuli, withholding responses to an infrequent “No Go” stimulus. Dorsolateral prefrontal cortex (DLPFC) activity to “Go” trials, and dorsal anterior cingulate (dACC) activity to “No Go” trials were associated with faster error-free performance; consistent with DLPFC and dACC facilitating proactive and reactive control, respectively. Trait anxiety was linked to reduced recruitment of these regions, slower error-free performance, and decreased frontal-thalamo-striatal connectivity. This indicates an association between trait anxiety and impoverished frontal control of attention, even when external distractors are absent. In task blocks where commission errors were made, greater DLPFC-precuneus and DLPFC-posterior cingulate connectivity were associated with both trait anxiety and worry, indicative of increased off-task thought. Notably, unlike trait anxiety, worry was not linked to reduced frontal-striatal-thalamo connectivity, impoverished frontal recruitment, or slowed responding during blocks without commission errors, contrary to accounts proposing a direct causal link between worry and impoverished attentional control. This leads us to propose a new model of the relationship between anxiety, worry and frontal engagement in attentional control versus off-task thought.

Background: People with severe and profound levels of intellectual disability (ID) are frequently examined as a single group in research. However, these two groups may be significantly different, particularly in the area of emotional and behavioural difficulties. Method: The Developmental Behaviour Checklist (DBC) was completed by parents and caregivers of 107 people with severe ID and 22 people with profound ID at four time periods across 12 years. Regression analyses were used to examine trends in sub-scale scores across time and groups. Results: Significant differences between the groups of people with severe and profound ID were found. People with profound ID had significantly lower scores across all sub-scales except "Social Relating." This was usually related to fewer items being selected as present for people with profound ID, as opposed to the scores being attributable to lower item severity scores. Conclusions: There are significant differences between groups of people with severe and profound ID in scores on the DBC, indicating differences in behavioural and emotional problems. Caution should be exercised by researchers treating these two disparate groups as a single group, and by practitioners translating such findings into practice.

Misophonia and hyperacusis are typically defined in terms of a narrow versus broad range of trigger sounds and are often linked to different aspects of a sound (sound meaning for misophonia, loudness for hyperacusis). However, co-morbidity between these conditions suggests possible mechanistic overlap. In two studies we examine the neurochemical and psychophysiological basis of misophonia (using a validated questionnaire) and hyperacusis (based on uncomfortable loudness thresholds). The technique of magnetic resonance spectroscopy (MRS) uses MRI to estimate the concentration of excitatory and inhibitory neurotransmitters in the brain, enabling us to explore whether either type of sound intolerance is linked to general levels of excitability in key regions of the brain (auditory cortex, insula). No differences were found. In a separate experimental study, participants engaged in an attention-demanding visual task whilst concurrently measuring responsiveness to task-irrelevant sounds (in terms of level of distraction, psychophysiological responsiveness). Here we do find that different aspects of the task are differentially sensitive to misophonia and hyperacusis. Misophonia is linked to heightened responsiveness to sounds whereas hyperacusis is linked hyper-vigilance. [ABSTRACT FROM AUTHOR]

Mineral deficiencies in common bean (Phaseolus vulgaris L.) negatively affect plant growth and development. Genetic differences in seed mineral concentrations have been detected among landraces and genotypes for trace elements such as Zn and Fe, and major elements such as P and Ca, and these differences have been exploited for the genetic improvement of the crop. The objectives of this study were (i) to develop and evaluate a navy bean recombinant inbred population segregating for seed Zn, (ii) to measure other micronutrients in the seeds such as Fe and the major elements P and Ca, and (iii) to identify associations between microsatellite markers and seed mineral content. Transgressive segregants were observed for seed Zn and variation was also found for Fe, P, and Ca. Bean microsatellites associated with Zn, P, and Ca were identified, but there was no association with Fe. Our molecular data identified a locus associated with seed Zn accumulation in bean located on linkage group 9. Further studies would help to find the exact location of the gene. As more information becomes available, breeders will be able to combine techniques of molecular genetics with conventional breeding methods through marker-assisted selection to develop cultivars with higher seed Zn content.

A dynamic scanning force microscopy study was conducted to investigate shape transitions of poly(ethylene-b-sulfonic acid) micelles that were formed at different ionic strength. Shape transitions from spherical micelles to network-like structures occurred when the ionic strength in the applied solution was changed. An examination of the adsorption behavior of the structures on different chemical surfaces revealed that the chemical modification of the surface strongly influenced the adsorption structures of the micellar aggregates on a substrate.

Examination of palladium colloids in the core of amphiphilic block polymer micelles showed strong catalytic activity during Heck reaction. Reaction rates are controlled by the reactivity of the educts and responded to micelle architecture and palladium dispersity. Adjusting the solvating block to the environment allowed the Heck reaction to occur with toluene instead of amidic solvents. Observations indicate that reductions with 'fresh' superhydride lead to very active catalyst systems.

In situ analysis from a sediment observatory shows that the 2 cm long mud shrimp, Callianassa truncata, makes unique burrows with complex architecture and function. The burrows influence the whole sedimentology and geochemistry of the sea bed. The mounds, funnels and first gallery of the open burrow system activate a hydrodynamic water exchange in the upper sediment layer. The biopumping of dissolved oxygen and the transport of detrital particles down to 60-80 cm sediment depths accelerates the organic matter degradation.