Attentional deficits in fibromyalgia and its relationships with pain,emotional distress and sleep dysfunction complaints

Cognitive complaints are common among subjects with fibromyalgia (FM). Yet, few studies have been able to document these deficits with cognitive tasks. A main limitation of existing studies is that attention has been broadly defined and the tasks used to measure attention are not designed to cover all the main components of the attentional system. Research on attention has identified three primary functions of attention, known as alerting, orienting and executive functioning. This study used the attentional network test-interactions task to explore whether and which of the three attentional networks are altered in FM. Results showed that FM patients have impaired executive control (greater interference), reduced vigilance (slower overall reaction time) and greater alertness (higher reduction in errors after a warning cue). Vigilance and alertness showed several relations with depression, anxiety and sleep quality. Sleep dysfunction was a significant predictor for alertness, whereas there were no significant predictors for vigilance. These findings highlight that the treatment of sleep difficulties in FM patients may help with some of their cognitive complaints.     

Alexithymia and Cardiovascular Risk in Older Adults: Psychosocial,Psychophysiological, and Biomedical Correlates

Psychosocial correlates of alexithymia were examined in 102 healthy, older adults (ages 53-83; 76% male). Alexithymic ( n = 26) and non-alexithymic ( n = 30) groups, defined by top ( S 70) and bottom ( h 54) quartiles of the distribution of Toronto Alexithymia Scale (26-item) scores, were compared with respect to psychosocial, psychophysiological, and biomedical risk factors for cardiovascular disease. Both categorical ratings and continuous scores of alexithymia were associated with significantly greater levels of trait anxiety, anger-in, neuroticism, hostility, perceived stress, depression, and lower levels of social support. Compared to non-alexithymics, alexithymics displayed significantly greater blood pressure responses to anger provocation and tended to have a greater percent body fat. The groups did not differ in resting cardiovascular parameters, heart rate reactivity, fasting glucose and lipoprotein lipids, body mass index, waist-to-hip ratio, social desirability, or trait anger. These findings suggest several psychosocial and psychophysiological pathways by which alexithymia may confer risk for cardiovascular disease among older adults.     

Demographic,health-related and psychosocial predictors of changes in depressive symptoms and anxiety in late middle-aged and older persons with fall-related injuries

Research on anxiety and depression after fall-related injuries to the extremities and its pre-fall determinants is scarce. The present study sought to examine change between pre-fall and post-fall anxiety and depression and its (pre-fall) predictors. Data were obtained from 181 Dutch persons, aged 57 and older, who sustained fall-related injuries between 1993 and 1997. Demographic (e.g. socio-economic status), health-related (e.g. number of chronic conditions), and psychosocial (e.g. social support, neuroticism) factors were determined in 1993 (prior to the fall). Depressive symptoms and anxiety were determined prior to the fall, and two, five and twelve months after the fall. Taking into account pre-fall anxiety and depression, pre-fall neuroticism was the most consistent, independent predictor of adverse changes in anxiety and depression. Other factors, including severity of the fall and age were not related to changes in anxiety and depression. Our prospective findings may be interpreted as support for the importance of personality for mental health outcomes in persons who have sustained fall-related injuries.     

Differential Development of Learning Strategies on a Pictorial Verbal Learning Test (PVLT) in Primary-School Children

The aim of this study was to test the hypothesis that developmental differences exist in the use of learning strategies in primary school children. Serial and subjective clustering in a multitrial Pictorial Verbal Learning Test (PVLT) were compared in 79 children aged 6–12. Correlation analyses indicated that serial clustering yielded better performance when information was presented on the initial trials of the test. Subjective clustering was superior when information was presented repeatedly, i.e., after three or more trials. Analyses of variance indicated that subjective clustering was used more often in older children with repeated presentations. On the other hand, there was no increase in the use of serial clustering with age and with repeated presentations. The findings imply that training in the use of proper strategies could have benefit for children who use an inefficient learning strategy and/or have a learning problem. In addition, they point to the importance of the factor “age” in relation to the way information is presented to children.     

Temperature-dependent crack surface tension

The fracture surface energy is calculated for a one-dimensional, exactly solvable model of a crack. The temperature dependence of the crack surface tension is determined on the basis of a self-consistent Einstein approach. It is found that lattice vibrations result in a strong reduction in the crack surface tension.     

Analysis of intrinsic diffusivities in multicomponent alloys

In this letter we consider the intrinsic diffusivities in a multicomponent random alloy in terms of the ratios of atom-vacancy exchange frequencies. Using the exact sum rule due to Moleko and Allnatt, which relates phenomenological coefficients in the multicomponent random alloy, we deduce an exact relationship between the intrinsic diffusivities and the ratios of the exchange frequencies. We exemplify the finding with a consideration of binary and ternary random alloys. We show that the new relationship should be robust enough for employment in multicomponent alloys showing non-ideality.     

Ferromagnetism in Kondo lattice models

We report the discovery of a new ferromagnetic phase in the one-dimensional Kondo lattice model for intermediate values of the coupling constant. This new ferromagnetic phase was observed using a non-Abelian density-matrix renormalization group algorithm, which allowed us to measure directly the magnetization of the ground state with high accuracy.     

Long-term natural ageing of a dissociated dislocation in a Cu-13.43 at.% Al alloy

The nature of impurity-dislocation interactions is one of the key questions governing the strength and plasticity of solid-solution materials. To investigate the influence of impurities on the mechanical properties of intermetallic NiAl, the electronic structure and energy of NiAl with a <100>{010} edge dislocation and transition-metal impurities was calculated using the real-space tight-binding linear muffin-tin orbital method. The localized electronic states, appearing in the core of the dislocation, are found to lead to strong impurity-dislocation interactions via two mechanisms: firstly, chemical locking, due to strong hybridization between impurity electronic states and dislocation localized states; secondly, electrostatic locking, due to long-range charge oscillations caused by the electron localization in the dislocation core. The results obtained explain qualitatively why the solid-solution hardening effect in NiAl correlates with the electronic structure of impurities rather than with size misfit, as expected according to traditional views.     

Diffusion kinetics for divacancies in the bcc lattice

In this letter we employ high-precision Monte Carlo simulations to investigate tracer diffusion kinetics for diffusion via divacancies in the bcc lattice. We utilize the mechanisms originally identified by Mehrer in which the divacancy can move by nearest-neighbour jumps with stable first-nearest-neighbour, second-nearest-neighbour and fourth-nearest-neighbour configurations of the divacancy. The tracer correlation factor and the 'impurity-form' correlation factor were found to be some 4-6% lower than those found by the matrix method. The tracer diffusion data and isotope effect for sodium were revisited in terms of monovacancy and divacancy contributions. The main change is a revision upwards from 0.55 to 0.61 of the j K kinetic factor for divacancies.     

Dislocations and cracks at Vickers indentations in (0 0 0 1) GaN single crystals

Single-crystal (0 0 0 1) GaN samples have been deformed with a Vickers indenter at room temperature using loads in the range from 0.02 to 4.90 N. Dislocations and cracks at the indentations were examined by means of scanning electron microscopy, cathodoluminescence, light microscopy and transmission electron microscopy. Geometrical relations could be found between the dislocation arrangement, cracks and the orientation of the indenter. The orientation of the indenter has only a slight effect on the dislocation pattern, but the crack system is predominantly determined by the symmetry and the orientation of the indenter.