Excitonic Mechanism of Local Phase Transformations by Optical Pumping

Transformations of cooperative electronic states by impacts of optical pumping and/or electrostatic doping is a new mainstream in physics of correlated systems. Here we present a semi-phenomenological modeling of spatio-temporal effects in a system where the light absorption goes through a channel creating the excitons—intra-molecular ones or bound electron–hole pairs—and finally the condensate of optical excitons feeds and stimulates phase transformations. Interacting with a near-critical order parameter and deformations, the excitons are subject to self-trapping. That locally enhances their density which can surpass a critical value to trigger the phase transformation, even if the mean density is below the required threshold. The model can be used e.g. as a simplified version of optically induced neutral-ionic transitions in organic chain compounds.     

On a decidable generalized quantifier logic corresponding to a decidable fragment of first-order logic

Van Lambalgen (1990) proposed a translation from a language containing a generalized quantifierQ into a first-order language enriched with a family of predicatesR _i, for every arityi (or an infinitary predicateR) which takesQxg(x, y₁,..., y_n) to x(R(x, y₁,..., y₁) (x,y₁,...,y_n)) (y ₁,...,y_n are precisely the free variables ofQx). The logic ofQ (without ordinary quantifiers) corresponds therefore to the fragment of first-order logic which contains only specially restricted quantification. We prove that it is decidable using the method of analytic tableaux. Related results were obtained by Andréka and Németi (1994) using the methods of algebraic logic.     

Why men and women continue to use social networking sites: The role of gender differences

Organizations increasingly use social media and especially social networking sites (SNS) to support their marketing agenda, enhance collaboration, and develop new capabilities. However, the success of SNS initiatives is largely dependent on sustainable user participation. In this study, we argue that the continuance intentions of users may be gender-sensitive. To theorize and investigate gender differences in the determinants of continuance intentions, this study draws on the expectation-confirmation model, the uses and gratification theory, as well as the self-construal theory and its extensions. Our survey of 488 users shows that while both men and women are motivated by the ability to self-enhance, there are some gender differences. Specifically, while women are mainly driven by relational uses, such as maintaining close ties and getting access to social information on close and distant networks, men base their continuance intentions on their ability to gain information of a general nature. Our research makes several contributions to the discourse in strategic information systems literature concerning the use of social media by individuals and organizations. Theoretically, it expands the understanding of the phenomenon of continuance intentions and specifically the role of the gender differences in its determinants. On a practical level, it delivers insights for SNS providers and marketers into how satisfaction and continuance intentions of male and female SNS users can be differentially promoted. Furthermore, as organizations increasingly rely on corporate social networks to foster collaboration and innovation, our insights deliver initial recommendations on how organizational social media initiatives can be supported with regard to gender-based differences.     

Neuropsychological impairment among manic, depressed, and mixed-episode inpatients with bipolar disorder.

Previous research has demonstrated broad neurobehavioral abnormalities in bipolar affective disorder (cf. G. Cassens, L. Wolfe, & M. Zola, 1990). However, there have been no comparisons of neuropsychological function across patients with manic, depressed, or mixed subtypes. In the present study, 37 manic, 24 mixed-episode, and 25 depressed bipolar I inpatients and 34 control subjects were administered a brief battery of neuropsychological tests. The multivariate and univariate effects of participant group on the neuropsychological measures were uniformly significant (p     

Lower precombat intelligence is a risk factor for posttraumatic stress disorder.

The authors examined the relation between intelligence and posttraumatic stress disorder (PTSD) by studying the association among precombat intelligence, current intelligence, and self-reported PTSD symptoms. Military aptitude test results were obtained in 59 PTSD and 31 non-PTSD Vietnam combat veterans who had undergone a psychodiagnostic interview and current intelligence testing. People with lower precombat intelligence were more likely to develop PTSD symptoms as assessed by the Clinician-Administered PTSD Scale even after adjustment for extent of combat exposure. The association between current intelligence and PTSD was no longer significant after adjusting for precombat intelligence. These results suggest that lower pretrauma intelligence increases risk for developing PTSD symptoms, not that PTSD lowers performance on intelligence tests. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

PTSD Arousal and Depression Symptoms Associated With Increased Right-Sided Parietal EEG Asymmetry.

Researchers have proposed that depression and particular types of anxiety are associated with unique patterns of regional brain activation. The authors examined the relationship among posttraumatic stress disorder (PTSD), anxiety, and depressive symptoms and frontal, temporal, and parietal EEG alpha asymmetry in female Vietnam War nurse veterans. The results indicate that PTSD arousal symptoms are associated with increased right-sided parietal activation. However, the combination of arousal, depression, and their interaction explain more than twice the variance in parietal asymmetry compared with arousal alone. The results support the contention that the association between anxiety and right-sided posterior activation is specific to the anxious arousal subtype. These findings underscore the importance of isolating, both theoretically and statistically, emotional subcomponents in studies of regional brain activation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of Grain Size and Humidity on the Nanotribological Properties of Wear-Resistant Nanostructured ZrO2 Coatings: An Atomic Force Microscopy Study

The nanotribological properties of nanostructured thin films of tetragonal ZrO₂ on oxidized Si (100) were studied as a function of grain size and relative humidity (RH) by atomic force microscopy. The nanostructured ZrO₂ showed a 50% decrease in friction coefficient μ compared with oxidized Si (100) in dry nitrogen atmosphere and 40% RH. A maximum of μ was observed at ca. 40% RH for both samples, while there were insignificant differences in μ for ZrO₂ samples with grain sizes between 12 and 30 nm. The good tribological properties open the possibility for nanostructured zirconia to be applied as wear-resistant, low friction coatings on various materials.     

Aerodynamic load maps of bluff bodies: Measurement and diagnostics

Bluff bodies may assume arbitrary attitudes in a flow, causing aerodynamic loads that are sensitive to attitude. The Continuous rotation technique obtains 6-component loads on bluff bodies with 1-degree azimuth resolution about selected axes at a rate of 1 revolution per minute. The load coefficient variation is Fourier transformed and the resulting complex series is truncated in order to obtain rapidly computable, analytical formulae. The method is applied to bluff body shapes including cylinders, a cuboid, a flat plate and a porous box. A cylinder whose length is equal to its diameter, is used to show that rate effects, hysteresis, vortex shedding and other unsteady aerodynamic phenomena are negligible below 10 revolutions per minute. Approaches to generalize the aerodynamic loads on yawed finite cylinders of various aspect ratio are studied. The reasons for differences in aerodynamic load behavior between 2 cylinder models, are analyzed. To complement experiments, the ROTCFD unsteady Navier Stokes code is used to perform diagnostic computations. Methods to generalize the predictions are explored. Maps of the leading coefficients of the Fourier series of each load component over the aspect ratios space, are interpolated. The interpolation varies sharply for aspect ratios between 0.5 to 1. The variation is more gradual beyond aspect ratio 2. By aspect ratio 4, a ‘high aspect ratio’ limit appears to be reached.     

Molecular Signatures in Urologic Tumors

Urologic tumors continue to represent a huge fraction of cancer cases in the United States, with over 376,310 estimated new diagnoses in 2013. As with many types of tumors, urologic tumors vary greatly in their phenotype, ranging from minimally invasive to malignancies possessing great metastatic potential. The increasing need for more efficient and less invasive methods of cancer detection, as well as the ability to predict severity of the disease phenotype is readily evident—yet reliable methods remain elusive in a clinical setting today. Comprehensive panels of gene clusters are being developed toward the generation of molecular signatures in order to better diagnose urologic malignancies, and identify effective treatment strategies in the emerging era of personalized medicine. In this review, we discuss the current literature on the credibility and biomarker value of such molecular signatures in the context of clinical significance relating to the pathological aggressiveness of urologic tumors (prostate, bladder and renal cancer)—also exploiting their predictive potential in the response to treatment.