On the basis of the framework of Perceptual Assimilation Model connected to speech perception, this paper reports on a study of the relationship between the experience of L1 (Chinese) and L2 (English) production from the point of lexical stress level. Chinese EFL speakers were recruited for this study. All the participants were required to read 20 words in the form of English, of which the lexical stress was recorded so as to make further analysis and comparison. The study indicates that the biggest challenge for Chinese EFL learners is the misplacement of word stress. It often occurs in polysyllabic words, and there is a strong tendency of stress shift on the second syllable. The dominant reason for the misplacement is that the second or the latter syllable is frequently stressed in mandarin dissyllables. This implies that Chinese EFL learners should lay more emphasis on phonological awareness of L2 and sufficient supply of L2 auditory input should also be assured in order to maintain the quality of perception and production in stress acquisition.

Cardiovascular imaging analysis is a useful tool for the diagnosis, treatment and monitoring of cardiovascular diseases. Imaging techniques allow non-invasive quantitative assessment of cardiac function, providing morphological, functional and dynamic information. Recent technological advances in ultrasound have made it possible to improve the quality of patient treatment, thanks to the use of modern image processing and analysis techniques. However, the acquisition of these dynamic three-dimensional (3D) images leads to the production of large volumes of data to process, from which cardiac structures must be extracted and analyzed during the cardiac cycle. Extraction, three-dimensional visualization, and qualification tools are currently used within the clinical routine, but unfortunately require significant interaction with the physician. These elements justify the development of new efficient and robust algorithms for structure extraction and cardiac motion estimation from three-dimensional images. As a result, making available to clinicians new means to accurately assess cardiac anatomy and function from three-dimensional images represents a definite advance in the investigation of a complete description of the heart from a single examination. The aim of this article is to show what advances have been made in 3D cardiac imaging by ultrasound and additionally to observe which areas have been studied under this imaging modality.