OBJECTIVES Identification of the causal impact of self-esteem on smoking stages faces seemingly insurmountable problems in observational data, where self-esteem is not manipulable by the researcher and cannot be assigned randomly. The aim of this study was to find out if weaker self-esteem in adolescence is a risk factor of cigarette smoking in a longitudinal study in Iran. METHODS In this lo...

OBJECTIVE Longitudinal studies on headaches often focus on the identification of risk factors for headache occurrence or "chronification". This study in particular examines psychological variables as potential predictors of headache remission in children and adolescents. METHODS Data on biological, social, and psychological variables were gathered by questionnaire as part of a large populatio...

Background Tobacco smoking harms health, so why do people smoke and fail to quit? An explanation originating in behavioural economics suggests a role for time-discounting, which describes how the value of a reward, such as better health, decreases with delay to its receipt. A large number of studies test the relationship of time-discounting with tobacco outcomes but the temporal pattern of this...

The dynamic mechanical behavior of excised rabbit papillary muscles that had been tonically activated by replacing bathing Ca2+ with Ba2+ was studied. Steady activation was used to visualize the dynamic behavior of cardiac myofilaments more clearly than is possible during twitches, which are complicated by the kinetics of excitation-contraction coupling. To avoid artifacts due to damaged ends o...

OBJECTIVE To explore the nature of paternal involvement in early child-rearing adopting a social developmental perspective, and estimate its effect on behavioural outcomes of children aged 9 and 11 years. SETTING The data come from the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort recruited in the former county of Avon in the southwest of England. PARTICIPANTS Out of the 1...

OBJECTIVE To investigate the clinical and imaging predictors of surgical outcomes in patients with ossification of the posterior longitudinal ligament (OPLL). MATERIALS AND METHODS From May 2010 to April 2012, a total of 200 consecutive patients with cervical OPLL were recruited for this study. Of them, 184 patients (130 men and 54 women) who could be tracked for more than 24 months after sur...

expansion equal channel angular extrusion (exp-ecae) is a severe plastic deformation (spd) operation for processing bulk materials. in the current study, aa7075 al was spd-processed by expansion equal channel angular extrusion (ex-ecae) at various temperatures and ram velocities. then, using split hopkinson pressure bar (shpb), the severely deformed products were compressed at room temperature ...

We study the depinning of a flux line by analytical and numerical methods applied to a phenomenological equation of motion. Transverse fluctuations do not influence the critical behavior of the longitudinal component, justifying “planar approximations”. In an isotropic medium, longitudinal fluctuations have a roughness exponent ζ‖ = 1, and relax with a dynamic exponent z‖ ≈ 4/3; transverse fluc...

Placing column lap-splice in the locations of possible nonlinear deformation may adversely affect the structures response to strong ground motions. Localization of damage in splice zone may change the structural response and prevent the load redistribution and development of a uniform pattern of nonlinear excursions among the various members. Validated by existing laboratory experiments, this s...