BACKGROUND The second to fourth digit ratio (2D:4D) is used as a marker of prenatal sex hormone exposure. The objective of this study was to examine whether circulating concentrations of sex hormones and SHBG measured in adulthood was associated with 2D:4D. METHODS This analysis was based on a random sample from the Melbourne Collaborative Cohort Study. The sample consisted of of 1036 men and...

Ventilation within the lung is air shift generated by displacements of intra-pulmonary structures according to the chest motion. In order to study lung anatomy, physiology, and pathology, 4D (=3D + time axis) models are necessary. The present author has developed software for generating 4D lung models from the trachea to alveoli. Since the lung models consist of 4D finite elements, air flow sim...

The 2nd to 4th finger digit ratio (2D:4D) is a sexually dimorphic feature determined during gestation indexing prenatal androgen/estrogen levels. More 'feminized' 2D:4D phenotype has been demonstrated in schizophrenia versus same-sex controls. This study examined 2D:4D in adolescents with schizotypal personality disorder (SPD). Among normal controls, right 2D:4D was significantly greater (more ...

Over the last decade we have been witness to a burgeoning literature on three-dimensional (3D) and four-dimensional (4D) ultrasound-based studies of the fetal cardiovascular system. Recent advances in the technology of 3D/4D ultrasound systems allow almost real-time 3D/4D fetal heart scans. It appears that 3D/4D ultrasound in fetal echocardiography may make a significant contribution to interdi...

Treatment planning based on respiration-correlated (“4D”) CT has become more common in recent years. Still, treatment delivery is typically 3D, i.e., a “one plan fits all” (motion phases) approach. 4D delivery in principle offers greater flexibility but also greater challenges, both computational and practical. We develop a computational framework to open up some of the 4D flexibility without g...

The picture of S-wave scattering from a 4D extremal dilatonic black hole is examined. Classically, a small matter shock wave will form a non-extremal black hole. In the “throat region” the r − t geometry is exactly that of a collapsing 2D black hole. The 4D Hawking radiation (in this classical background) gives the 2D Hawking radiation exactly in the throat region. Inclusion of the back-reactio...

The sestamibi scan (MIBI) and ultrasound (US) are used for preoperative localization of parathyroid adenoma (PTA), with sensitivity as high as 90%. We developed 4-dimensional magnetic resonance imaging (4D MRI) as a novel tool for identifying PTAs. Eleven patients with PTA were enrolled. 4D MRI from the mandible to the aortic arch was used. Optimization of the timing of image acquisition was ob...

The formulation of the National Centers for Environmental Prediction four-dimensional variational dataassimilation (4D-Var) system is described. Results of applying 4D-Var over a one-week assimilation period, with a full set of physical parametrizations, are presented and compared with those of 3D-Var. The linearization has been performed without simplifications and, therefore, the tangent-line...

BACKGROUND AND PURPOSE 4D-MRA is a promising technique in the diagnosis and follow-up of cAVMs. The purpose of this study was to compare 4D-MRA in the pre- and postoperative evaluation of cAVMs with DSA or intraoperative findings as the standards of reference regarding qualitative and quantitative parameters. MATERIALS AND METHODS Fifty-six consecutive patients with cAVMs (30 women) underwent...