Discriminant Analysis Using Mixed Continuous,Dichotomous, and Ordered Categorical Variables

This article proposes an intuitive approach for predictive discriminant analysis with mixed continuous, dichotomous, and ordered categorical variables that are defined via an underlying multivariate normal distribution with a threshold specification. The classification rule is based on the comparison of the observed data logarithm probability density functions. To reduce the computational burden, the analysis is conducted in the context of a confirmatory factor analysis model with independent error measurements. Identification of the dichotomous and ordered categorical variables is discussed. Results are obtained by implementations of a Monte Carlo expectation maximization (MCEM)algorithm and a path sampling procedure. Probabilities of misclassification are estimated via the idea of the “jackknife” method. A real example is given to illustrate the proposed method.     

Myelin breakdown mediates age-related slowing in cognitive processing speed in healthy elderly men

Background

To assess the hypothesis that in a sample of very healthy elderly men selected to minimize risk for Alzheimer’s disease (AD) and cerebrovascular disease, myelin breakdown in late-myelinating regions mediates age-related slowing in cognitive processing speed (CPS).

Materials and methods

The prefrontal lobe white matter and the genu of the corpus callosum myelinate later in brain development (late-myelinating white matter; LMWM) and are more vulnerable to breakdown due to the effects of normal aging. An in vivo MRI biomarker of myelin integrity (transverse relaxation rates; R₂) of LMWM was obtained for 38 very healthy elderly adult men (mean age = 66.3 years; SD = 6.0; range = 55–76). To evaluate regional specificity, we also assessed a contrasting early-myelinating region (splenium of the corpus callosum; SWM), which primarily contains axons involved in visual processing. CPS was assessed using the Trail Making Test.

Results

LMWM R₂ and CPS measures were significantly correlated (r = .515, p = .0009), but no significant association between R₂ and CPS was detected in the splenium (p = .409). LMWM R₂, but not SWM R₂, was a significant mediator of the relationship between age and CPS (p = .037).

Conclusions

In this very healthy elderly sample, age-related slowing in CPS is mediated by myelin breakdown in highly vulnerable late-myelinating regions but not in the splenium.     

Microstructures and tensile properties of 304 steel with dual nanocrystalline and microcrystalline austenite content prepared by aluminothermic reaction casting

The microstructures of 304 stainless steels with different amounts of nanocrystalline and microcrystalline austenite prepared by an aluminothermic reaction casting, without and with annealing at 1073?K for 8?h, have been investigated by X-ray diffraction, an electron probe micro-analyser, a transmission electron microscope and a scanning electron microscope. The steels, both without and with annealing, consisted of different dual nanocrystalline and microcrystalline austenite combinations and a little nanocrystalline δ ferrite, while the average grain size of the nanocrystalline austenite increased from 19 to 26?nm and volume fraction of the microcrystalline austenite increased from 17 to 30% after annealing. The tensile strength of the steel was dramatically increased from 500 to 1000?MPa and the tensile elongation ratio increased from 8 to 12% after annealing. However, the tensile strength was decreased to 600?MPa and the tensile elongation ratio increased from 12 to 22% after an annealing at 1273?K. The combination of dual nanocrystalline and microcrystalline austenite obtained after the annealing at 1073?K results in the best tensile properties.     

Nanoindentation-induced elastic–plastic transition and size effect in α-Al2O3(0001)

The mechanical properties of α-Al₂O₃(0001) have been investigated using the technique of nanoindentation with a Berkovich indenter. Coupled with the Hertzian contact theory, a theoretical shear strength of 28?±?2?GPa was determined from the onset of pop-in events on load–displacement curves during loading, and the intrinsic hardness 30?±?3?GPa was obtained by analysis of the so-called indentation size effect, based on the concept of geometrically necessary dislocations. The predicted values of the shear strength, hardness and elastic modulus are in good agreement with available experimental data. The importance of experimentally calibrating the area function over the contact depth range prior to nanoindentation tests is emphasized.     

Vacancy-decomposition-induced lattice instability and its correlation with the kinetic stability limit of crystals

Vacancy decomposition kinetics in crystals at elevated temperatures is analysed. It is found that lattice instability is induced by a significantly enhanced vacancy decomposition at a critical temperature (T?*). The critical temperature coincides with the kinetic instability limit (kinetic limit of superheating) of crystals in a variety of metals determined from the homogeneous nucleation catastrophe model.     

Qualitative Exploration of Acculturation and Life‐Span Issues of Elderly Asian Americans

Awareness of aging issues across diverse populations begins the journey toward counselors becoming culturally competent across client life spans. Understanding the life‐span experiences of cultural groups is important for helping professionals. The purpose of this research was to gain insight into the qualitative experiences of Asian American elders. The authors conducted semistructured interviews with 8 participants between September 2010 and March 2011 and analyzed the data using the Consensual Qualitative Research method. Findings indicate unique patterns in life‐span development with this population.     

Theater and Psychological Development: Assessing Socio-Cognitive Complexity in the Domain of Theater

Theater is a millenary art form that has stably maintained its minimum indispensable elements over the years. Yet, not much is known about the psychological impact of this performing art. A literature review shows a broad and sometimes contradictory spectrum of theoretical and empirical evidence. In the last few decades, however, interdisciplinary studies, namely in the emerging field of neuroaesthetics, has allowed the emergence of new perspectives on the study of the arts. Drawing from these findings, and to better understand the impact of theater in the socio-cognitive development of actors, directors, and other practitioners, this study tested the construction of an instrument exploring complexity of thought in relation to theater. A preliminary study for the Scale of Socio-cognitive Complexity in the Domain of Theatre (SSCDT) showed that, among a sample of 222, individuals with higher levels of experience in acting and directing seem to demonstrate higher levels of cognitive complexity. To our knowledge, this was the first study aiming to develop a simple paper-and-pencil instrument capable of providing data about the psychological impact of theater in terms of socio-cognitive complexity.     

晚明清初儒学转型中的性命论演进

作为儒学研究的重要内容,性命论在晚明清初儒学转型进程中呈现极为复杂的发展形态。于晚明三教合流趋势中,部分儒者所持性命论主张对佛、道思想具有极高程度的包容力,由此引发大规模的"正统""异端"之争;于心学修正思潮中,东林学派及之后刘宗周对传统儒学"性命"之说秉持更为严肃的坚守态度,如此,"性命"的客观义、超越义得到强调;清初,在形上学渐趋没落之际,部分儒学人士对"性命"的诠释多从"材质之性"谈起——侧重对现实人生延续及发展等诉求的考量,此时性命论"天"字义渐次流失,"命"的世俗义得到落实。