The role of motion platform on postural instability and head vibration exposure at driving simulators

This paper explains the effect of a motion platform for driving simulators on postural instability and head vibration exposure. The sensed head level-vehicle (visual cues) level longitudinal and lateral accelerations (a_x,sensed = a_{x_head} and a_y,sensed = a_{y_head}, a_yv = a_{y_veh} and a_yv = a_{y_veh}) were saved by using a motion tracking sensor and a simulation software respectively. Then, associated vibration dose values (VDVs) were computed at head level during the driving sessions. Furthermore, the postural instabilities of the participants were measured as longitudinal and lateral subject body centre of pressure (X_CP and Y_CP, respectively) displacements just after each driving session via a balance platform. The results revealed that the optic-head inertial level longitudinal accelerations indicated a negative non-significant correlation (r = −.203, p = .154 > .05) for the static case, whereas the optic-head inertial longitudinal accelerations depicted a so small negative non-significant correlation (r = −.066, p = .643 > .05) that can be negligible for the dynamic condition. The X_CP for the dynamic case indicated a significant higher value than the static situation (t(47), p < .0001). The VDV_x for the dynamic case yielded a significant higher value than the static situation (U(47), p < .0001). The optic-head inertial lateral accelerations resulted a negative significant correlation (r = −.376, p = .007 < .05) for the static platform, whereas the optic-head inertial lateral accelerations showed a positive significant correlation (r = .418, p = .002 < .05) at dynamic platform condition. The VDV_y for the static case indicated a significant higher value rather than the dynamic situation (U(47), p < .0001). The Y_CP for the static case yielded significantly higher than the dynamic situation (t(47), p = .001 < 0.05).     

Relational dynamics of charismatic organization: The complementarity of love and power

Abstract: This paper outlines a new theory of structural transformation in charismatic systems by postulating a complementary relationship between love and power. Radical reorganization of social organization, the function of charismatic systems, requires mobilizing and realigning enormous amounts of social energy. The source of this social energy is love. When patterned as communion, love fuses the group into an undifferentiated whole and releases the social energy previously locked up as institutionalized structure.

Released from structure or form, however, social energy is highly volatile and produces immense pressures towards instability. Counterbalancing the pressure from communion, a strong, collective order of power functions to harness and align the energy, thereby promoting group stability and enhancing the prospects for structural transformation. Data from a national study of sixty urban communal organizations are used to ground key aspects of the theory.     

Effect of electron concentration on the Laves phase stability of NbCr2–Ni produced by powder metallurgy

The powder metallurgy technology of mechanical alloying followed by hot-pressing consolidation has been used to obtain NbCr₂–Ni Laves phases. High-purity Nb, Cr, and Ni crystalline powders were milled for periods up to 35 h. These powders were vacuum sintered at 1250°C for 0.5 h under 45 MPa. The phase transformations of NbCr₂–Ni Laves phases have been investigated by X-ray diffraction. The grain size decreases and the microstrain increases with increased Ni content. Different phase transformations were observed from NbCr₂–Ni intermetallics. It is found that the electron concentration and phase stability correlation is obeyed in the Nb–Cr–Ni systems. However, the electron concentration corresponding to the C15/C14 phase transition is found to move to a higher value (i.e. 6.103) than the predicted one (i.e. 5.88) in the literature.     

Nanocomposite-like structure in an epitaxial CaCu3Ti4O12 film on LaAlO3 (001)

We report the detailed microstructural study of a CaCu₃Ti₄O₁₂ (CCTO) thin film using transmission electron microscopy (TEM). The CCTO thin film studied in this work was deposited on a (001)-oriented LaAlO₃ (LAO) substrate by pulsed-laser ablation and has a high dielectric constant of about 10⁴ at 1?MHz at room temperature; however, the mechanism for such a dielectric property is not yet understood. Plan-view TEM studies show that the CCTO samples have orthogonal domain structures with the edge nearly parallel to either the [100] or the [010] direction of the CCTO. A minor anatase TiO₂ phase was found at the domain boundaries. The CCTO and the TiO₂ phases are separated by an amorphous-like layer that has a thickness of several nanometres. Cross-sectional TEM studies reveal that both CCTO and TiO₂ in the films are c axis oriented with a very sharp interface to the LAO-(001) substrate and possess a unique crystallographic orientation relationship of (001) _CCTO //(001)_{TiO 2} //(001) _LAO and [100] _CCTO //[100] _{TiO 2} //[100] _LAO. The Rutherford back-scattering ion chanelling studies suggest a composition of Ca_1.5Cu₃Ti_5.5O₁₆ for the film, in which the extra calcium, titanium and oxygen form the anatase TiO₂ phase and amorphous calcium oxide layer that separates the CCTO and TiO₂ phases. Such nanocomposite-like structures may provide an important clue to the mechanism of the dielectric property of these films.     

Stages of change in fruit intake: A longitudinal examination of stability,stage transitions and transition profiles

The present study examined stability and transitions in Transtheoretical stages of change for fruit intake in an adult cohort of 735 individuals not exposed to a planned intervention. Six assessments took place within a four-month period with varying time intervals using electronic questionnaires, measuring fruit intake, stage of change and demographic characteristics. Precontemplation and maintenance were the most stable stages of change, while preparation was the least stable. Longer time intervals showed lower stability, but frequent stage transitions also occurred in shorter time intervals. Seven transition profiles were distinguished. Sequences within transition profiles mostly showed stage transitions to adjacent stages, independent of the interval duration. Differences in fruit intake, age, level of education and ethnicity were found between different transition profiles. Stability rates and most transition sequences largely support the Transtheoretical Model. Results indicating potential deviations from the model, e.g. short-term stage instability and stage transition profiles not in accordance with the Transtheoretical Model are discussed.     

G1agov——血管重构与传奇

美国病理学和血管外科学家Seymour Glagov教授在1987年首次提出了血管重构现象,确认斑块占血管的横截面积大约小于40％时动脉代偿性扩张,其理论影响至今。他的科学历程透射出20世纪80年代粥样硬化研究革命期的特点,能启示后来者。     

Stability and predictors of psychopathic traits from mid‐adolescence through early adulthood

High levels of psychopathic traits in youth are associated with multiple negative outcomes including substance misuse, aggressive behavior, and criminality. Evidence regarding stability of psychopathic traits is contradictory. No previous study has examined long‐term stability of psychopathic traits assessed with validated clinical measures. The present study examined the stability of psychopathic traits from mid‐adolescence to early adulthood and explored adolescent factors that predicted psychopathic traits five years later. The sample included 99 women and 81 men who had consulted a clinic for substance misuse in adolescence. At an average age of 16.8 years, the adolescents were assessed using the Psychopathy Checklist: Youth Version (PCL: YV) and five years later using the PCL‐Revised (PCL‐R). Additionally, extensive clinical assessments of the adolescents and their parents were completed in mid‐adolescence. Among both females and males, moderate to high rank‐order stability was observed for total PCL and facet scores. Among both females and males, there was a decrease in the mean total PCL score, interpersonal facet score, affective facet score, and lifestyle facet score. However, the great majority of females and males showed no change in psychopathy scores over the five‐year period as indicated by the Reliable Change Index. Despite the measures of multiple family and individual factors in adolescence, only aggressive behavior and male sex predicted PCL‐R total scores in early adulthood after taking account of PCL:YV scores. Taken together, these results from a sample who engaged in antisocial behavior in adolescence suggest that factors promoting high psychopathy scores act early in life.     

Forms of friendship: A person-centered assessment of the quality,stability, and outcomes of different types of adolescent friends

Friendships differ in terms of their quality and participants may or may not agree as to their perceptions of relationship quality. Two studies (N = 230 and 242) were conducted to identify distinct and replicable categories of friendship among young adolescents (M = 11.6 years old) using self and partner reports of relationship quality. Same-sex friendships were identified from reciprocated friend nominations. Each friend described perceptions of negativity and social support in the relationship. Cluster analyses based on reports from both friends yielded 4 friendship types in each study: a high quality group, a low quality group, and two groups in which friends disagreed about the quality of the relationship. High quality friendships were most apt to be stable from the 6th to the 7th grade. Participants in high quality friendships reported the highest levels of global self-worth and perceived behavioral conduct and the lowest levels of problem behaviors. Dyads reporting discrepant perceptions of quality differed from dyads who agreed that the friendship was high quality in terms of stability and individual adjustment, underscoring the advantages of person-centered strategies that incorporate perceptions of both partners in categorizations of relationships.     

Stabilité à long terme des scores du WISC-IV : forces et faiblesses personnelles

Intelligence is considered as a stable trait over time; psychologists make predictions about the future performance of the child from the interpretation of the WISC-IV scores. However, stability at interindividual level does not necessarily imply stability at intra-individual level. By a test-retest procedure, the stability of categories that classify the performances, and the stability of the personal strengths and personal weaknesses are evaluated on a sample of 277 children aged from seven to 12 years. Categorical stability reveals that the classification into seven categories proposed by the designers of the WISC-IV does not allow reliable predictions. The stability of personal strengths and personal weaknesses is unsatisfactory for the different index scores.