Accelerating heterogeneous nucleation to increase hardness and electrical conductivity by deformation prior to ageing for Cu-4 at.% Ti alloy

ABSTRACT

Deformation bands, especially shear bands were intentionally formed in supersaturated Cu-4 at.% Ti alloy by groove-rolling with 75% area reduction. Cold deformation prior to the ageing process changed the precipitation behaviour of the alloy. The deformed structure with shear bands was maintained, without showing recovery and recrystallisation, even after prolonged ageing at 450°C for more than one day. The thermally stable shear bands act as nucleation initiation sites and prevent the expansion of discontinuous cellular precipitates. The hardness reached a value of 305?Hv and an electrical conductivity of 15% IACS (IACS?=?International Annealed Copper Standard. 100% IACS is defined as the conductivity corresponding to a volume resistivity at 20°C of 17.241?nΩ), compared to 283?Hv and 13% IACS for conventional solid-solutioned and peak-hardened alloy. In addition, the ageing time to reach the highest hardness was shortened from 720 to 180?min at 450°C.     

Gender-role conflict and gender-role orientation in a sample of gay men

This exploratory study was designed to examine the relationship between gender role dimensions derived from the Bem Sex-Role Inventory (BSRI) and the 4 dimensions of gender role conflict represented on the Gender Role Conflict Scale (GRCS) using a sample (N = 400) composed of exclusively gay men. Results from regression of 3 BSRI scores (femininity, social masculinity, personal masculinity) on the 4 subscale scores of the GRCS indicated that gender role conflict was most strongly and positively associated with the negative aspect of masculinity (social masculinity), accounting for about 11% of variability in social masculinity scores. In particular, the success-power-competition dimension of the GRCS was the major predictor of social masculinity in gay men. Gender role conflict was also strongly but negatively associated with femininity, accounting for approximately 10% of the variance in femininity scores among the men in the sample. Implications and recommendations for further studies are discussed.     

A presynaptic role for FMRP during protein synthesis-dependent long-term plasticity in Aplysia

Loss of the Fragile X mental retardation protein (FMRP) is associated with presumed postsynaptic deficits in mouse models of Fragile X syndrome. However, the possible presynaptic roles of FMRP in learning-related plasticity have received little attention. As a result, the mechanisms whereby FMRP influences synaptic function remain poorly understood. To investigate the cellular locus of the effects of FMRP on synaptic plasticity, we cloned the Aplysia homolog of FMRP and find it to be highly expressed in neurons. By selectively down-regulating FMRP in individual Aplysia neurons at the sensory-to-motor neuron synapse reconstituted in co-cultures, we demonstrate that FMRP functions both pre- and postsynaptically to constrain the expression of long-term synaptic depression induced by repeated pulses of FMRF-amide. In contrast, FMRP has little to no effect on long-term synaptic facilitation induced by repeated pulses of serotonin. Since other components of signaling pathways involved in plasticity appear to be conserved between Aplysia and mammalian neurons, our findings suggest that FMRP can participate in both pre- and postsynaptic regulation of enduring synaptic plasticity that underlies the storage of certain types of long-term memory.     

Item banks for measuring emotional distress from the Patient-Reported Outcomes Measurement Information System (PROMIS®): depression, anxiety, and anger

The authors report on the development and calibration of item banks for depression, anxiety, and anger as part of the Patient-Reported Outcomes Measurement Information System (PROMIS?). Comprehensive literature searches yielded an initial bank of 1,404 items from 305 instruments. After qualitative item analysis (including focus groups and cognitive interviewing), 168 items (56 for each construct) were written in a first person, past tense format with a 7-day time frame and five response options reflecting frequency. The calibration sample included nearly 15,000 respondents. Final banks of 28, 29, and 29 items were calibrated for depression, anxiety, and anger, respectively, using item response theory. Test information curves showed that the PROMIS item banks provided more information than conventional measures in a range of severity from approximately -1 to +3 standard deviations (with higher scores indicating greater distress). Short forms consisting of seven to eight items provided information comparable to legacy measures containing more items.     

Acculturation, enculturation, and Asian American college students' mental health and attitudes toward seeking professional psychological help

In the present study, we tested a theoretically and empirically derived partially indirect effects acculturation and enculturation model of Asian American college students' mental health and attitudes toward seeking professional psychological help. Latent variable path analysis with 296 self-identified Asian American college students supported the partially indirect effects model and demonstrated the ways in which behavioral acculturation, behavioral enculturation, values acculturation, values enculturation, and acculturation gap family conflict related to mental health and attitudes toward seeking professional psychological help directly and indirectly through acculturative stress. We also tested a generational status moderator hypothesis to determine whether differences in model-implied relationships emerged across U.S.- (n = 185) and foreign-born (n = 107) participants. Consistent with this hypothesis, statistically significant differences in structural coefficients emerged across generational status. Limitations, future directions for research, and counseling implications are discussed.     

A simple 5-DoF MR-compatible motion signal measurement system

The purpose of this study was to develop a simple motion measurement system with magnetic resonance (MR) compatibility and safety. The motion measurement system proposed here can measure 5-DoF motion signals without deteriorating the MR images, and it has no effect on the intense and homogeneous main magnetic field, the temporal-gradient magnetic field (which varies rapidly with time), the transceiver radio frequency (RF) coil, and the RF pulse during MR data acquisition. A three-axis accelerometer and a two-axis gyroscope were used to measure 5-DoF motion signals, and Velcro was used to attach a sensor module to a finger or wrist. To minimize the interference between the MR imaging system and the motion measurement system, nonmagnetic materials were used for all electric circuit components in an MR shield room. To remove the effect of RF pulse, an amplifier, modulation circuit, and power supply were located in a shielded case, which was made of copper and aluminum. The motion signal was modulated to an optic signal using pulse width modulation, and the modulated optic signal was transmitted outside the MR shield room using a high-intensity light-emitting diode and an optic cable. The motion signal was recorded on a PC by demodulating the transmitted optic signal into an electric signal. Various kinematic variables, such as angle, acceleration, velocity, and jerk, can be measured or calculated by using the motion measurement system developed here. This system also enables motion tracking by extracting the position information from the motion signals. It was verified that MR images and motion signals could reliably be measured simultaneously.     

A Comparison of Hindsight Bias in Groups and Individuals: The Moderating Role of Plausibility

We compared the magnitude of the hindsight bias in individuals and groups with the prediction that the plausibility of an outcome would affect the magnitude of the group–individual difference. We provided groups and individuals with outcomes of scientific studies, and asked them to predict the probability of those outcomes as if they did not know the given outcomes and to report their level of surprise at the outcomes. Overall, groups were more prone to hindsight bias than were individuals, but the group–individual difference was present only when the given outcomes were relatively implausible (Study 1). Moreover, this difference was not eliminated even when participants were asked to consider alternative outcomes (Study 2). Implications are discussed.     

The Accuracy of Self-Reports of Condom Use and Sexual Behavior

In a study of the accuracy of self-reports of sexual behavior and condom use, 285 single, young adults in a large metropolitan area were interviewed once a week for 52 weeks, reporting on their sexual behavior each week. At 1-, 3-, 6-, and 12-month intervals, the individuals also provided self-reports of the number of times they had engaged in sex and the number of times they had used condoms since they began participating in the study. These self-reports were compared with aggregates of the weekly data, which served as a comparison standard for accuracy evaluation. The results indicate a fairly high level of accuracy in self-reports, but with 2% to 5% outliers who are highly inaccurate. The results tend to favor the assessment of sexual behavior over moderate time durations (3 or 6 months) rather than short or long durations (1 month or 12 months) when trying to maximize self-report accuracy. Accuracy was attenuated for individuals who tended to engage in sex frequently, especially at the 12-month time durations.