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The damage mechanisms and load redistribution of high strength TC17 titanium alloy/unidirectional SiC fibre composite (fibre diameter = 100 $\mu$m) under high temperature (350 {\deg}C) fatigue cycling have been investigated in situ using synchrotron X-ray computed tomography (CT) and X-ray diffraction (XRD) for high cycle fatigue (HCF) under different stress amplitudes. The three-dimensional morphology of the crack and fibre fractures has been mapped by CT. During stable growth, matrix cracking dominates with the crack deflecting (by 50-100 $\mu$m in height) when bypassing bridging fibres. A small number of bridging fibres have fractured close to the matrix crack plane especially under relatively high stress amplitude cycling. Loading to the peak stress led to rapid crack growth accompanied by a burst of fibre fractures. Many of the fibre fractures occurred 50-300 $\mu$m from the matrix crack plane during rapid growth, in contrast to that in the stable growth stage, leading to extensive fibre pull-out on the fracture surface. The changes in fibre loading, interfacial stress, and the extent of fibre-matrix debonding in the vicinity of the crack have been mapped for the fatigue cycle and after the rapid growth by high spatial resolution XRD. The fibre/matrix interfacial sliding extends up to 600 $\mu$m (in the stable growth zone) or 700 $\mu$m (in the rapid growth zone) either side of the crack plane. The direction of interfacial shear stress reverses with the loading cycle, with the maximum frictional sliding stress reaching ~55 MPa in both the stable growth and rapid growth regimes.

Major revolts have recently erupted in parts of the Middle East with substantial international repercussions. Predicting, coping with and winning those revolts have become a grave problem for many regimes and for world powers. We propose a new model of such revolts that describes their evolution by building on the classic Lanchester theory of combat. The model accounts for the split in the population between those loyal to the regime and those favoring the rebels. We show that, contrary to classical Lanchesterian insights regarding traditional force-on-force engagements, the outcome of a revolt is independent of the initial force sizes; it only depends on the fraction of the population supporting each side and their combat effectiveness. We also consider the effects of foreign intervention and of shifting loyalties of the two populations during the conflict. The model's predictions are consistent with the situations currently observed in Afghanistan, Libya and Syria (Spring 2011) and it offers tentative guidance on policy.

Most social interactions involve spontaneous or unintentional behavior. Deliberate behavior, however, represents intentional action. An individual may display a particular emotion or behave in a systematic fashion to convey or conceal a specific type of affect. Often, an observer will question the authenticity of a behavior sequence, deciding whether it is spontaneous or deliberate. This report examines the cognitive basis underlying this discrimination. Thirty-six observers viewed a sequence of nonverbal behavior that was described as being either spontaneous (the stimulus person was filmed with a hidden camera) or deliberate (the person was acting). While watching the videotape, observers segmented behavior into meaningful units. Results indicated that observers who believed that they were watching deliberate behavior generated approximately twice as many units for the nonverbal sequence as compared to observers who believed that they were viewing spontaneous action. The findings are discussed in terms of a cognitive schema that an observer uses in the active organization of behavioral events. (Authors/CJ)

Observers viewed silent videotapes of elementary school children listening to a lesson. Some of the stimulus children were listening to either a very easy or a very difficult lesson; consequently, their nonverbal behavior occurred naturally and spontaneously. Other stimulus children were instructed to pretend (role play) that they understood or did not understand the lesson; thus, their nonverbal behavior was deliberate or intentional. Observers were required to judge whether each stimulus person's behavior was spontaneous or deliberate. Results indicated that the observers did significantly differentiate between spontaneous and deliberate behavior on the basis of facial responses alone. (Authors)

This experiment was designed to investigate the generality-specificity of the accuracy of both encoders and decoders across different types of nonverbal behavior. It was expected that encoders and decoders would exhibit generality in their behavior--i.e., the same level of accuracy--on the dimension of behavior content (comprehension/noncomprehension). Less generality of accuracy was expected on the dimension of mode of behavior (spontaneous/role play). Contrary to predictions, results indicated a high degree of specificity across both content and mode of behavior when the data were analyzed separately for encoders and decoders. These findings seriously question the conclusion of previous reports suggesting high generality in the encoding and decoding of nonverbal behavior. Instead, individuals appear to be quite situation-specific in their ability to encode and decode nonverbal behavior. A theoretical interpretation of the results is offered. (Author)

Two studies investigated the effects of training on how accurately observers (college students) decoded a complex nonverbal stimulus. In the first experiment, observers viewed silent videotapes of 16 third and fourth-grade school children who were listening to an easy or a difficult lesson. Half of the children were responding spontaneously, while the other half had been instructed to pretend that they either understood or did not understand the lesson. Observers were asked to make judgments about the type of behavior they had witnessed (spontaneous or deliberate, and easy or difficult). Some observers were given feedback about their decoding accuracy after each trial, others were given feedback plus an opportunity to discuss the decision among themselves, and a third group served as the control. Results showed that all observers demonstrated a consistent practice effect, but neither feedback nor feedback plus discussion improved decoding accuracy above the level of the control group. The second study examined the effect of practice alone (10 practice trials plus six test trials). Results indicated that when compared to a no-experience control group (who just decoded the six test trials), practice had no effect on decoding accuracy. (Author/HOD)