It is generally agreed that schizophrenia patients show a markedly reduced ability to perceive and express facial emotions. Previous studies have shown, however, that such deficits are emotion-specific in schizophrenia and not generalized. Three kinds of studies were examined: decoding studies dealing with schizophrenia patients' ability to perceive universally recognized facial expressions of emotions, encoding studies dealing with schizophrenia patients' ability to express certain facial emotions, and studies of subjective reactions of patients' sensitivity toward universally recognized facial expressions of emotions. A review of these studies shows that schizophrenia patients, despite a general impairment of perception or expression of facial emotions, are highly sensitive to certain negative emotions of fear and anger. These observations are discussed in the light of hemispheric theory, which accounts for a generalized performance deficit, and social-cognitive theory, which accounts for an emotion-specific deficit in schizophrenia.

A new fluorescent probe, methylamino derivative of pyrene, has been considered to characterize the concentration dependent emission behavior of an aqueous solution of anionic surfactants, viz., SDS, DSS, and SDBS. It was found that the emission of the probe is uniquely sensitive to the changes in surfactant (anionic) concentration due to the functional group effect of the probe over the parent moiety, pyrene. Here, 1-methylaminopyrene (MAP) showed significant quenching of emission well below the critical micellar concentration (cmc) of the surfactant. Excimer emission of the probe due to the formation of premicellar aggregates of the surfactant solutions at a concentration close to but below the cmc and again an enhanced emission of the probe above the cmc were observed as a consequence of definite MAP-surfactant interactions. These observations assisted the possible quantification ofsurfactant concentrations and their chain length dependent premicellar aggregate formations. Significant monomer emission in relation to probe distribution in micelle was analytically authenticated. Dynamic light scattering (DLS) studies revealed the incorporation of the probe molecules in the micellar core. The fluorophore emission showed nonlinear behavior when the surfactant concentration was far above the cmc. Abrupt changes in the emission characteristics in relation to the micellar concentration led to the determination of the cmc of the surfactants.

We report here enhancement of ferromagnetism in pure ZnO upon thermal annealing with the ferromagnetic transition temperature Tc above room temperature. We observe a finite coercive field upto 300K and a finite thermoremanent magnetization upto 340K for the annealed sample. We propose that magnetic moments can form at anionic vacancy clusters. Ferromagnetism can occur due to either superexchange between vacancy clusters via isolated F + centers, or through a limited electron delocalization between vacancy clusters. Isolated vacancy clusters or isolated F + centers give rise to a strong paramagnetic like behaviour below 10K.

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Bimetallic gold and silver particles, a core−shell type structure, have been prepared by a UV-photoactivation technique. The optical absorption spectra are recorded and compared with various absorption profiles due to Au−Ag particles described in the literature. Initially Au particles formed by UV irradiation, which act as the seed particles, catalyzed the reduction of added silver ion in the presence of UV light to yield bimetallic (Aucore−Agshell) particles. Preferential dissolution of Au particles by cyanide and TEM images of the particles corroborates the “core−shell” type configuration.