Pressure-Induced transitions in amorphous TlxSe100−x alloys

Abstract

The electrical resistivity of bulk semiconducting amorphous Tl_xSe_100?x alloys with 0 ≤ x ≤ 25 has been investigated up to a pressure of 14 GPa and down to liquidnitrogen temperature by use of a Bridgman anvil device. All the glasses undergo a discontinuous pressure-induced semiconducting-to-metal transition. X-ray diffraction studies on the pressure-recovered samples show that the high-pressure phase is the crystalline phase. The pressure-induced crystalline products are identified to be a mixture of Se having a hexagonal structure with a = 4·37 Å and c = 4·95 Å and TlSe having a tetragonal structure with a = 8·0 Å and c = 7·0 Å     

The Impact of Cooperative and Competitive Instructions on the Performance of Friendly and Hostile Complementary Mixed-Sex Dyads

Using a circumplex model of interpersonal acts, Estroff and Nowicki (1992) had found that mixed-sex hostile complementary dyads with a man dominant and a woman submissive put fewer pieces of a jigsaw puzzle together than did any other complementary pairings. In the present investigation, three studies were completed to examine the hypothesis that the performance of mixed-sex complementary dyads with a man dominant and a woman submissive is negatively impacted when hostile pairings are asked to cooperate and friendly ones are asked to compete. Results were consistent with this hypothesis.     

Development of Bengali Audio–Visual Test Battery for Assessment of Pragmatic Skills: Preliminary Normative Data Based on Educational Level

Pragmatic competence may be disrupted due to psychological and neurological causes. For appropriate remedy and rehabilitation, a precise assessment of pragmatic skills is important. However, there is no test battery in the Bengali language, and consequently, there is no published data on pragmatic ability of Bengali speakers. Due to the vast diversity of the population, it becomes increasingly difficult to assess pragmatic ability of an individual without a proper knowledge of the normal variations. To address this problem we have developed a test battery in Bengali, and to begin with, we have administered it to one hundred and five (105) normal healthy persons having different levels of education. The four groups having 17 years and above, 15 to < 17 years, 12 to < 15 years and 10 to < 12 years of education yielded a normative score of 193, 189, 171 and 150, respectively. These normative scores will allow clinicians to make a proper assessment of patients suffering from pragmatic deficits and help avoid interpreting social differences as neurological deficits.     

Tracking transitional probabilities and segmenting auditory sequences are dissociable processes in adults and neonates

Since speech is a continuous stream with no systematic boundaries between words, how do pre-verbal infants manage to discover words? A proposed solution is that they might use the transitional probability between adjacent syllables, which drops at word boundaries. Here, we tested the limits of this mechanism by increasing the size of the word-unit to four syllables, and its automaticity by testing asleep neonates. Using markers of statistical learning in neonates’ EEG, compared to adult behavioral performances in the same task, we confirmed that statistical learning is automatic enough to be efficient even in sleeping neonates. We also revealed that: (1) Successfully tracking transition probabilities (TP) in a sequence is not sufficient to segment it. (2) Prosodic cues, as subtle as subliminal pauses, enable to recover words segmenting capacities. (3) Adults’ and neonates’ capacities to segment streams seem remarkably similar despite the difference of maturation and expertise. Finally, we observed that learning increased the overall similarity of neural responses across infants during exposure to the stream, providing a novel neural marker to monitor learning. Thus, from birth, infants are equipped with adult-like tools, allowing them to extract small coherent word-like units from auditory streams, based on the combination of statistical analyses and auditory parsing cues.

Research Highlights

• Successfully tracking transitional probabilities in a sequence is not always sufficient to segment it.
• Word segmentation solely based on transitional probability is limited to bi- or tri-syllabic elements.
• Prosodic cues, as subtle as subliminal pauses, enable to recover chunking capacities in sleeping neonates and awake adults for quadriplets.