Role of Cdx factors in early mesodermal fate decisions.

Murine cardiac and hematopoietic progenitors are derived from mesoderm. Cdx function impacts both yolk sac hematopoiesis and cardiogenesis in zebrafish, suggesting that Cdx family members regulate early mesoderm cell fate decisions. We found that Cdx2 occupies a number of transcription factor loci during embryogenesis, including key regulators of both cardiac and blood development, and that Cdx function is required for normal expression of the cardiogenic transcription factors and Furthermore, Cdx and Brg1, an ATPase subunit of the SWI/SNF chromatin remodeling complex, co-occupy a number of loci, suggesting that Cdx family members regulate target gene expression through alterations in chromatin architecture.

Creation and Online Use of Patient-Centered Videos, Digital Storytelling, and Interactive Self-testing Questions for Teaching Pathophysiology.

Background: Nursing students need to not only understand the pathophysiological basis of disease but also acquire insight into its effects on patients and their families.

Purpose: Digital storytelling was used to engage students in self-directed, online learning, allowing them to identify with patients dealing with disease and its consequences.

Methods: Scripts were written and videos created that simulated patient experiences with select diseases of the gastrointestinal and respiratory systems as well as diabetes.

Towards the optical second: verifying optical clocks at the SI limit.

The pursuit of ever more precise measures of time and frequency motivates redefinition of the second in terms of an optical atomic transition. To ensure continuity with the current definition, based on the microwave hyperfine transition in Cs, it is necessary to measure the absolute frequency of candidate optical standards relative to primary cesium references. Armed with independent measurements, a stringent test of optical clocks can be made by comparing ratios of absolute frequency measurements against optical frequency ratios measured via direct optical comparison.

Optical-Clock-Based Time Scale.

A time scale is a procedure for accurately and continuously marking the passage of time. It is exemplified by Coordinated Universal Time (UTC) and provides the backbone for critical navigation tools such as the Global Positioning System. Present time scales employ microwave atomic clocks, whose attributes can be combined and averaged in a manner such that the composite is more stable, accurate, and reliable than the output of any individual clock.