The orientation of swimming bi-flagellates in shear flows

Biflagellated algae swim in mean directions that are governed by their environments. For example, many algae can swim upward on average (gravitaxis) and toward downwelling fluid (gyrotaxis) via a variety of mechanisms. Accumulations of cells within the fluid can induce hydrodynamic instabilities leading to patterns and flow, termed bioconvection, which may be of particular relevance to algal bioreactors and plankton dynamics. Furthermore, knowledge of the behavior of an individual swimming cell subject to imposed flow is prerequisite to a full understanding of the scaled-up bulk behavior and population dynamics of cells in oceans and lakes; swimming behavior and patchiness will impact opportunities for interactions, which are at the heart of population models. Hence, better estimates of population level parameters necessitate a detailed understanding of cell swimming bias. Using the method of regularized Stokeslets, numerical computations are developed to investigate the swimming behavior of and fluid flow around gyrotactic prolate spheroidal biflagellates with five distinct flagellar beats. In particular, we explore cell reorientation mechanisms associated with bottom-heaviness and sedimentation and find that they are commensurate and complementary. Furthermore, using an experimentally measured flagellar beat for Chlamydomonas reinhardtii, we reveal that the effective cell eccentricity of the swimming cell is much smaller than for the inanimate body alone, suggesting that the cells may be modeled satisfactorily as self-propelled spheres. Finally, we propose a method to estimate the effective cell eccentricity of any biflagellate when flagellar beat images are obtained haphazardly

Vermont's Choices for Care Medicaid Long-Term Services Waiver: Progress and Challenges as the Program Concluded Its Third Year

Based on case study interviews and state data, evaluates the impact of a waiver introduced in 2005 to improve Medicaid beneficiaries' access to home and community-based services while reducing the use of nursing home care and controlling costs

A Snapshot of U.S. Physicians: Key Findings From the 2008 Health Tracking Physician Survey

Analyzes survey data on U.S. physicians' compensation system, career satisfaction, acceptance of new patients, managed care contracts, and charity care provision by demographics, type of practice, specialty, geographic location, and other characteristics

Nonnegative/binary matrix factorization with a D-Wave quantum annealer

D-Wave quantum annealers represent a novel computational architecture and have attracted significant interest, but have been used for few real-world computations. Machine learning has been identified as an area where quantum annealing may be useful. Here, we show that the D-Wave 2X can be effectively used as part of an unsupervised machine learning method. This method can be used to analyze large datasets. The D-Wave only limits the number of features that can be extracted from the dataset. We apply this method to learn the features from a set of facial images

Making Medical Homes Work: Moving From Concept to Practice

Explores practical considerations for implementing a medical home program of physician practices committed to coordinating and integrating care based on patient needs and priorities, such as how to qualify medical homes and how to match patients to them

Coordination of Care by Primary Care Practices: Strategies, Lessons and Implications

Documents successful strategies for coordinating care within primary care settings, including family and caregivers; with specialists; with hospital settings; and with community-based services. Discusses challenges, lessons learned, and implications

Physicians Slow to E-mail With Patients

Presents survey findings on physicians' use of e-mail to communicate with patients about clinical issues; frequency of use; determining factors such as access to electronic health records and employment by health maintenance organizations; and barriers

Friendly-Contention Ads Using Multiple Endorsers: Assessing Source Effects On Attribute Perceptions And Brand Attitudes

Our study is a preliminary investigation of multiple-source friendly-contention ads in which various endorsers argue about the brand's main benefit(s).  The results demonstrate that such an ad convinced viewers that originally seemingly inconsistent attributes and benefits could both be found in the advertised brand.  Further, the tested advertising format produced more favorable brand attitudes than did an equivalently informative single-source ad version.  The argumentative ad appears entirely appropriate in industries where a company wishes to target heavy product users