Goos-H\"{a}nchen-Like Shifts in Atom Optics

We consider the propagation of a matter wavepacket of two-level atoms through a square potential created by a super-Gaussian laser beam. We explore the matter wave analog of Goos-H\"{a}nchen shift within the framework of atom optics where the roles of atom and light is exchanged with respect to conventional optics. Using a vector theory, where atoms are treated as particles possessing two internal spin components, we show that not only large negative but also large positive Goos-H\"{a}nchen shifts can occur in the reflected atomic beam.Comment: 7 pages, 4 figure

The Motivation Theory of Life-Span Development and Its Implications for Career Education

Based on the Selective Optimization with Compensation (SOC) and control model, the Motivational Theory of Life-Span Development (MTLSD) proposes adaptive development criteria and objectives. It asserts that the pursuit of perpetual development is the primary control and that the life cycle is an action field with an opportunity and constraint structure of time organization. Opportunity is a process characterized by the change processes of escalating and waning and by the adaptation consistency processes of goal participation and goal separation. The MTLSD has endeavored to elucidate how people actively promote their own personal lifelong development throughout its entirety. This provides illumination for China’s career education. The importance of individual initiative in career development, the process of opportunity in the continuity of career education, the difference of career education in different career (major) life cycles, and the fairness of career education during the transitional period of social mobility (opportunity) must be emphasized

Vitamin C Prevents Hypogonadal Bone Loss

Epidemiologic studies correlate low vitamin C intake with bone loss. The genetic deletion of enzymes involved in de novo vitamin C synthesis in mice, likewise, causes severe osteoporosis. However, very few studies have evaluated a protective role of this dietary supplement on the skeleton. Here, we show that the ingestion of vitamin C prevents the low-turnover bone loss following ovariectomy in mice. We show that this prevention in areal bone mineral density and micro-CT parameters results from the stimulation of bone formation, demonstrable in vivo by histomorphometry, bone marker measurements, and quantitative PCR. Notably, the reductions in the bone formation rate, plasma osteocalcin levels, and ex vivo osteoblast gene expression 8 weeks post-ovariectomy are all returned to levels of sham-operated controls. The study establishes vitamin C as a skeletal anabolic agent. © 2012 Zhu et al