Background: Standard visual acuity using reverse contrast (white-on-black) has been shown to be significantly better than standard contrast (black-on-white). We examined whether differences in luminance contrast would have any effect on a visual sequential memory task. Methods: Forty-two subjects (23 males, 19 females) performed two tests of visual sequential memory specifically designed for th...

Introduction: Myocardial perfusion imaging is a nuclear medicine imaging method that is used to detect coronary artery diseases. One of the main sources of error in this imaging method is the detection of Compton scattered photons in the photopeak energy window used for data acquisition. This results in the degradation of the image contrast, and therefore decreases the...

X-ray grating interferometer can simultaneously retrieve attenuation, refraction, and scattering signals of the imaged sample, which shows its great potential in biomedical imaging. However, fast scan gratings high centrifugal forces during rotating grating-based cone-beam computed tomography (CBCT) system may lead to phase-stepping (PS) errors position fluctuations, cause reconstruction failur...

improvement of soil properties through sustainable agriculture requires suitable management of plant residues. this study was conducted to investigate the effect of different types and managements of plant residue on soil physical properties in a field experiment as factorial based on rcbd with three replicates. the first factor was residue type including barley straw and alfalfa residue, and t...

objective: we sought to determine the usefulness of the 99mtc-mibi (mibi) washout rate for the evaluation of steroid therapy in cardiac sarcoidosis (cs). methods: eleven cs patients underwent mibi myocardial spect both before and 6 months after initiating steroid therapy. the washout rate (wor) of mibi was calculated using early and delayed polar map images. the washout score (wos) of mibi was ...

PURPOSE To psychophysically demonstrate vision improvement when correcting higher-order aberrations with phase plates in normal eyes. METHODS The wavefront aberrations of three nonsurgical normal eyes were measured with a Shack-Hartmann wavefront sensor. With these measured aberrations, phase plates were fabricated using a lathing technique. Theoretical improvement in retinal image quality wa...

Nowadays, effort estimation in software projects is turned to one of the key concerns for project managers. In fact, accurately estimating of essential effort to produce and improve a software product is effective in software projects success or fail, which is considered as a vital factor. Lack of access to satisfying accuracy and little flexibility in existing estimation models have attracted ...