Grain-boundary states in solid oxide electrolyte ceramics processed using iron oxide sintering aids: a Mössbauer spectroscopy study

Journal of Solid State Electrochemistry - In order to appraise microstructure-determined defect formation processes and minor intergranular states in the solid electrolyte materials sintered...     

Heritability of Stroop and flanker performance in 12-year old children

Background  

There is great interest in appropriate phenotypes that serve as indicator of genetically transmitted frontal (dys)function, such as ADHD. Here we investigate the ability to deal with response conflict, and we ask to what extent performance variation on response interference tasks is caused by genetic variation. We tested a large sample of 12-year old monozygotic and dizygotic twins on two well-known and closely related response interference tasks; the color Stroop task and the Eriksen flanker task. Using structural equation modelling we assessed the heritability of several performance indices derived from those tasks.     

The contribution of high frequencies to human brain activity underlying horizontal localization of natural spatial sounds

Background  

In the field of auditory neuroscience, much research has focused on the neural processes underlying human sound localization. A recent magnetoencephalography (MEG) study investigated localization-related brain activity by measuring the N1m event-related response originating in the auditory cortex. It was found that the dynamic range of the right-hemispheric N1m response, defined as the mean difference in response magnitude between contralateral and ipsilateral stimulation, reflects cortical activity related to the discrimination of horizontal sound direction. Interestingly, the results also suggested that the presence of realistic spectral information within horizontally located spatial sounds resulted in a larger right-hemispheric N1m dynamic range. Spectral cues being predominant at high frequencies, the present study further investigated the issue by removing frequencies from the spatial stimuli with low-pass filtering. This resulted in a stepwise elimination of direction-specific spectral information. Interaural time and level differences were kept constant. The original, unfiltered stimuli were broadband noise signals presented from five frontal horizontal directions and binaurally recorded for eight human subjects with miniature microphones placed in each subject's ear canals. Stimuli were presented to the subjects during MEG registration and in a behavioral listening experiment.     

X-ray powder diffraction and57Fe Mössbauer spectroscopy study of the thermal breakdown of vivianite,Fe3(PO4)2.8H2O

Ferric phosphates resulting from the thermal breakdown of natural Fe₃(PO₄)₂.₈H₂O are studied by X-ray powder diffraction and Mössbauer spectroscopy. Total iron oxidation and water release give rise to an amorphous material. During heating, a transitional cristobalite-type ferric orthophosphate recrystallizes prior to the stable berlinite-type. The main additional final product is a poorly characterized “Fe₃PO₇” phase with iron in octahedral coordination.     

Coupling of a sheep anti-T3 IgG to a solid phase for a triiodothyronine radioimmunoassay

Optimal conditions for coupling sheep anti-T₃ IgG to a solid phase are presented. We found that the optimal activation of microcrystalline cellulose was achieved with 0.15M 1,1-carbonyldiimidazol (CDI) in acetone. We also found that using a 25 mg/cm³ anti-T₃ IgG solution, in barbitone buffer 0.05M, pH 8.0, we could get a reasonable yield of coupling and a remaining solution of anti-T₃ IgG (first supernatant) with a suitable concentration (10 mg/cm³) for another coupling. The solid phase anti-T₃ obtained in these two couplings present similar characteristics which make possible their use in a total T₃ RIA.