Correlations of glucose metabolism and structural damage to language function in aphasia

Studies of aphasic patients using [18F]fluorodeoxyglucose positron computed tomographs have shown areas of metabolic depression in the left hemisphere larger than the area of infarction noted on CT. To evaluate these metabolic differences in relationship to language abnormalities, 11 patients had metabolic scans, CT, and were administered the Boston Diagnostic Aphasia Battery and the Porch Index of Communicative Ability. Correlation analyses were computed between metabolic, CT, and language data. CT demonstrated reliable correlations of speaking, oral reading, and repetition to Wernicke' area, consistent with current anatomic language models, while metabolic data from areas posterior, inferior, and superior to the traditional Wernicke's area and the head of the caudate nucleus also had reliable correlations with aphasic language function. The utilization of both structural and metabolic brain measures may improve our understanding of the anatomy of language as related to aphasia.     

Motivating Operations Affect Stimulus Control: A Largely Overlooked Phenomenon in Discrimination Learning

Several recent studies have explored what Michael (e.g., 1982) termed the value-altering effect and the behavior-altering effect of motivating operations. One aspect of the behavior-altering effect that has garnered no recent attention involves changes in stimulus control produced by motivating operations. To call attention to this aspect of the behavior-altering effect, we herein review 11 studies that are concerned with the influence of varying levels of food or water deprivation on stimulus generalization. These studies suggest that motivating operations influence stimulus control (a) by changing the evocative strength of not just an established discriminative stimulus, but also of stimuli that are physically similar to it; (b) by changing the range of stimuli that evoke the operant in question; and (c) by exerting these effects in a graded fashion. These findings are potentially of conceptual and applied significance, and it appears that further research examining how motivating operations alter stimulus control, including some studies suggested herein, is warranted.     

Coexistence of adjacent vacancy-ordered and eutectic phases in Al–Cu–Ni alloys

ABSTRACT

Copper-mould-cast Al–Cu–Ni alloys show adjacent coexistence of in situ grown ordered and eutectic phases. A bimodal microstructure of α–Al and eutectic α-Al+θ-Al₂Cu phases with length-scale hierarchy evolves during solidification. Microstructural analysis through Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) shows the presence of Vacancy-ordered phases (VOPs) with different morphologies in two different compositions.     

Microwave-dielectric and magnetic properties of Ta-doped BiFeO3 nanopowders

BiFe_{1? x} Ta _x O₃ (x = 0, 0.05, 0.1) nanopowders have been fabricated by a simple sol–gel method. Dielectric measurements at microwave frequencies (2–18 GHz) were made using a vector network analyser. Without tantalum, the BiFeO₃ nanopowder presents a relaxation-like response with a characteristic frequency of 15 GHz, which can be associated with an overdamped process. The Ta-doped nanopowders, however, show resonant behaviour with resonant frequencies of 12.5 and 14.6 GHz. The intensity of the resonant peak near 14.6 GHz decreases with increasing Ta addition. This behaviour is associated with a damped resonance process. Room-temperature magnetic measurements indicate that the addition of Ta influences the magnetic properties of the BiFeO₃ nanopowders, with BiFe_0.95Ta_0.05O₃ having the strongest ferromagnetism with a saturation magnetisation M _s of about 0.05 µ_B/Fe. The origin of the enhanced ferromagnetism is possibly associated with the distortion of the oxygen octahedral by the Ta substitution or/and the statistical distribution of Fe³⁺ and Fe²⁺.     

Surface effect on the screw dislocation mobility over the Peierls barrier

The effect of the image force on the Peierls stress (τ _p ) of a screw dislocation below a free surface is studied via a self-consistent semidiscrete variational Peierls–Nabarro model. The consequence of reduction in elastic energy and increase in stacking fault energy by the presence of the free surface is found to additively increase the Peierls stress (τ _p ). This model gives a physical interpretation of the same tend observed in a recent molecular dynamic study, while previous continuum analysis predicted the opposite.     

In situ characterization of the martensitic transformation temperature of NiTi shape memory alloys via instrumented microindentation

A novel, instrumented microindentation technique was successfully used to measure the temperature associated with the martensitic transformation leading to the recovery of plastic strain in a Nickel–Titanium (NiTi) shape memory alloy. Following a standard indentation cycle, the indenter was partially unloaded such that a good contact was maintained between indenter and specimen surface. The onset and finish temperature of the martensitic transformation, the associated volume contraction, and the amount of the recovered plastic deformation were determined by quantifying the indenter displacement as a function of temperature. These experiments were compared to conventional measurements of the transformation temperature by differential scanning calorimetry and compression testing.     

Site preference of refractory elements in γ′-Ni3Al alloyed with Ru

The influence of ruthenium (Ru) on the partitioning behavior of W, Re and Cr in γ′-Ni₃Al has been studied using the Dmol3 method based on the density functional theory. The calculated results show that W, Re and Cr have a preference for the Ni site in γ′-Ni₃Al alloyed with Ru. When Ru substitutes the central Ni atom, the site preference for W, Re and Cr varies. Furthermore, an electronic structure analysis of the alloy in terms of the Mulliken population and partial density of states was performed to elucidate the alloying mechanism of Ru in γ′-Ni₃Al. The results show that the strengthening effect of Ru in the alloy arises from a reduction in the binding energy of Ru as well as p-orbital hybridization between Ru and the host atoms.     

Phase-transformation-induced hardening in Zn–22Al alloys

A phase-transformation-induced hardening effect is reported in Zn–22Al (Al: 22?wt.%) alloys. The Zn–22Al specimens were held at 300?°C for 10?h and then quenched in water. A hardening effect took place in subsequent artificial aging at 100–200?°C, which was accompanied by a phase decomposition of a soft α ₂ phase and a grain coarsening. The phase-transformation-induced hardening affects the hardness more than the grain-coarsening-induced softening, which leads to the age-hardening phenomenon.     

Time-Out Training Without Put-Backs,Spanks, or Restraint: A Brief Report of Deferred Time-Out

We demonstrate the effectiveness of a procedure to increase compliance in young children who are resistant to Time-out (TO). Parents of two boys, 3 and 4 years of age, were unable to enforce TO without resorting to physical guidance and restraint. With deferred TO (DTO), if a child resists TO, caregivers no longer interact with the child or provide the child with tangibles or activities that the child cannot access independently. When the child requests a preferred item or activity from the caregiver that cannot be obtained independently, the child must first serve TO. Once TO is served, the caregiver may fulfill the child's request. Data suggest that DTO reduces the latency between the parental TO command and compliance with TO without put-backs, spanks, or restraint.     

Mirror neurons and their function in cognitively understood empathy

The current renewal of interest in empathy is closely connected to the recent neurobiological discovery of mirror neurons. Although the concept of empathy has been widely deployed, we shall focus upon one main psychological function it serves: enabling us to understand other peoples’ intentions. In this essay we will draw on neuroscientific, psychological, and philosophical literature in order to investigate the relationships between mirror neurons and empathy as to intention understanding. Firstly, it will be explored whether mirror neurons are the neural basis of our empathic capacities: a vast array of empirical results appears to confirm this hypothesis. Secondly, the higher level capacity of reenactive empathy will be examined and the question will be addressed whether philosophical analysis alone is able to provide a foundation for this more abstract level of empathy. The conclusion will be drawn that both empirical evidence and philosophical analysis can jointly contribute to the clarification of the concept of empathy.