Open AccessEngineering NotesRelative Orbit Determination for Unconnected Spacecraft Within a ConstellationTong Qin, Dong Qiao and Malcolm MacdonaldTong QinTsinghua University, 100084 Beijing, People’s Republic of China*Postdoctoral Researcher, Department Precision Instrument; .Search more papers by this author, QiaoBeijing Institute Technology, 100081 China†Professor, School Aerospace Engineeri...

BACKGROUND Clinical officers (COs), a mid-level cadre of health worker, are the backbone of healthcare provision in rural Kenya. However, the vacancy rate for COs in rural primary healthcare facilities is high. Little is known about factors motivating COs' preferences for rural postings. METHODS A discrete choice experiment (DCE) questionnaire was used with 57 COs at public health facilities ...

The response of a cell in the primary visual cortex to an optimally oriented grating is suppressed by a superimposed orthogonal grating. This cross-orientation suppression (COS) is exhibited when the orthogonal and optimal stimuli are presented to the same eye (monoptically) or to different eyes (dichoptically). A recent study suggested that monoptic COS arises from subcortical processes; howev...

Carbonyl sulfide (COS) is a promising tracer for partitioning terrestrial photosynthesis and respiration from net carbon fluxes, based on its daytime co-uptake alongside CO2 through leaf stomata. Because ecosystem COS fluxes are the sum of plant and soil fluxes, using COS as a photosynthesis tracer requires accurate knowledge of soil COS fluxes. At an oak woodland in Southern California, we mon...

Chi (5'-GCTGGTGG) is a recombinator in RecA-RecBC-mediated recombination in Escherichia coli. In bacteriophage lambda vegetative recombination, Chi is fully active only when it is correctly oriented with respect to cos, the site that defines the ends of the packaged chromosome. Here we demonstrate that packaging from cos is not necessary for this cos-Chi interaction. Our evidence suggests that ...

The Classroom of the Sea (COS) Project is an interactive problem-based learning environment embedded in marine science for deaf high school students to assist them in understanding and communicating scientific concepts. COS mixes a real and virtual environment for the students and teachers aboard a research vessel as they gather marine science data to address a problem. The students note the lo...