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Interoception in autism is receiving increasing research attention. Previously, differences were identified in autism on both objective and subjective measures of interoception, and an association with anxiety. Yet, it is currently unknown how interoception relates to core autism features. Here, in 49 autistic children, we consider how interoceptive accuracy (measured with heartbeat detection tasks) and sensibility (subjective judgements of awareness) relate to overall severity on the Autism Diagnostic Observation Schedule, and symptom domains of social-affective and repetitive, restricted behaviors. Socio-affective features were related to interoceptive sensibility, while repetitive restricted behaviors were related to interoceptive accuracy. This dissociation suggests disparate interoceptive mechanisms for the formation and/or maintenance of autistic features. [ABSTRACT FROM AUTHOR]

Human ancestors first modified stones into tools 2.6 million years ago, initiating a cascading increase in technological complexity that continues today. A parallel trend of brain expansion during the Paleolithic has motivated over 100 years of theorizing linking stone toolmaking and human brain evolution, but empirical support remains limited. Our study provides the first direct experimental evidence identifying likely neuroanatomical targets of natural selection acting on toolmaking ability. Subjects received MRI and DTI scans before, during, and after a 2-year Paleolithic toolmaking training program. White matter fractional anisotropy (FA) showed changes in branches of the superior longitudinal fasciculus leading into left supramarginal gyrus, bilateral ventral precentral gyri, and right inferior frontal gyrus pars triangularis. FA increased from Scan 1-2, a period of intense training, and decreased from Scan 2-3, a period of reduced training. Voxel-based morphometry found a similar trend toward gray matter expansion in the left supramarginal gyrus from Scan 1-2 and a reversal of this effect from Scan 2-3. FA changes correlated with training hours and with motor performance, and probabilistic tractography confirmed that white matter changes projected to gray matter changes and to regions that activate during Paleolithic toolmaking. These results show that acquisition of Paleolithic toolmaking skills elicits structural remodeling of recently evolved brain regions supporting human tool use, providing a mechanistic link between stone toolmaking and human brain evolution. These regions participate not only in toolmaking, but also in other complex functions including action planning and language, in keeping with the hypothesized co-evolution of these functions. [ABSTRACT FROM AUTHOR]

Cerium oxide is a very useful base material used as catalyst supports, ion conductors and gas sensors. It is also well known that ceria-based materials are difficult to densify below 1500°C. However, a small amount of Fe doping obviously promotes the densification rate and reduces the sintering temperatures. In this study, the early stage sintering mechanisms of undoped and Fe-doped CeO2 were investigated, based on two sintering models. We confirm that pure CeO2 exhibits volume-diffusion controlled sintering, while a viscous flow mechanism dominates the early stage sintering of Fe-doped CeO2. [ABSTRACT FROM AUTHOR]

There is currently much interest in the synchronisation of neural discharge and the potential role it may play in information coding within the nervous system. We describe some recent results from investigations of synchronisation within the motor system. Local field potentials (LFPs) and identified pyramidal tract neurones (PTNs) were recorded from the primary motor cortex of monkeys trained to perform a precision grip task. The LFPs showed bursts of oscillatory activity at 20–30 Hz, which were coherent with the rectified electromyographs (EMG) of contralateral hand and forearm muscles. This oscillatory synchronisation showed a highly specific task dependence, being present only during the part of the task when the animal maintained a steady grip and not during the movement phases before or after it. PTNs were phase-locked to LFP oscillations, implying that at least part of the coherence between cortical activity and EMG was mediated by corticospinal fibres. The phase locking of the PTNs to LFP oscillations produced task-dependent oscillatory synchronisation between PTN pairs, as assessed by the single-unit cross-correlation histogram. Recordings were also made from normal human subjects performing a precision grip similar to that used in the monkey recordings. Pairs of EMGs recorded from intrinsic hand and forearm muscles showed 20–30 Hz coherence, which modulated during task performance, being present only during periods of steady contraction. We suggest that these changes in EMG-EMG synchronisation reflect changing levels of synchronous drive from the corticospinal system. The generation of oscillations in the cortex is discussed in the light of results from a model of local cortical circuits. Other modelling work has shown that synchrony in the corticospinal inputs could act to recruit motoneurones more efficiently, producing more output force from a muscle than asynchronous inputs firing at the same mean rate. A speculative hypothesis is presented on the role of synchronous oscillations in the motor system, which is consistent with experimental observations to date. [ABSTRACT FROM AUTHOR]

Recently there has been substantial interest in optimising perovskite type ceramics as mixed ionic-electronic conductors (MIECs) for use in ceramic oxygen generators and solid oxide fuel cells. However these materials suffer from thermomechanical deficiencies and therefore there is a need to develop alternative materials. Using the IEDP/SIMS technique the La2−xSrxNi1−yFeyO4+δ series of compounds has been investigated and the oxygen tracer diffusion and surface exchange coefficients determined. It has been found that the oxide ion diffusivity of the x and y=0 material is very close to that of the fast oxide ion conducting perovskites such as La1−xSrxCoO3 (LSC) but on acceptor doping with Sr a considerable decrease in the oxygen tracer diffusion coefficient was observed. Further studies on the effects of B site doping, where y>0, indicate that this has very little effect on the transport properties. [ABSTRACT FROM AUTHOR]

The CEPPAD Experiment consists of four sensors for investigating energetic particle phenomena on the POLAR mission. These sensors provide 3-D proton and electron angular distributions in the energy range of 20 keV to 1 MeV, energetic proton and electron measurements extending to energies greater than 10 MEV, high angular and time resolution measurements in the loss-cone, and data on energetic neutral particles. All sensors operate in conjunction with special on-board data processing units which control sensor data acquisition modes while performing in-flight data processing, data compression, and telemetry formatting. Presented here is a CEPPAD system overview together with descriptions of the individual sensors, the in-flight data processing, and examples of sensor calibration data. [ABSTRACT FROM AUTHOR]

Dense samples of the perovskite SmSrCoO (where x=0, 0.2, 0.4, 0.5 and 0.6) have been prepared. The samples wereO/O isotopically exchanged at a variety of temperatures between 500°C and 900°C. Subsequent analysis of the diffusion profile using Secondary Ion Mass Spectrometry (SIMS) allowed the oxygen self-diffusion coefficient, D*, and surface exchange co-efficient, k, to be determined. From the temperature dependence of these parameters the activation energies for both processes were evaluated. The surface coverage of samarium, cobalt and oxygen in SmCoO was determined from calibration samples using Low Energy Ion Scattering (LEIS). LEIS was used to determine the effect of strontium doping on the surface composition and theO-concentration at the surface of a number of theO-exchanged samples. [ABSTRACT FROM AUTHOR]

The article focuses on the preparation and electrical properties of dense submicron-grained Ce0.8Gd0.2O2-&b.delta; ceramics. Ceria-based solid solutions, such as 20 at% (atomic ratio) Gd or Sm-doped ceria, have been regarded as the most promising electrolytes for intermediate temperature solid oxide fuel cell (SOFC) (IT-SOFC) because of their higher ionic conductivity than YSZ (yttria stabilized zirconia). On the other hand, weak mechanical strength is another problem that hinders the numerous applications of ceria-based materials. The ionic conductivity of samples was measured by a two-probe complex impedance analysis. The crystal phase was identified by XRD (X-ray diffraction).