MEASURING ECONOMIC GROWTH IN RURAL COMMUNITIES: THE SHIFT-SHARE APPROACH

Community/Rural/Urban Development,

On the nonlinear stability of a high-speed, axisymmetric boundary layer

The stability of a high-speed, axisymmetric boundary layer is investigated using secondary instability theory and direct numerical simulation. Parametric studies based on the temporal secondary instability theory identify subharmonic secondary instability as a likely path to transition on a cylinder at Mach 4.5. The theoretical predictions are validated by direct numerical simulation at temporally-evolving primary and secondary disturbances in an axisymmetric boundary-layer flow. At small amplitudes of the secondary disturbance, predicted growth rates agree to several significant digits with values obtained from the spectrally-accurate solution of the compressible Navier-Stokes equations. Qualitative agreement persists to large amplitudes of the secondary disturbance. Moderate transverse curvature is shown to significantly affect the growth rate of axisymmetric second mode disturbances, the likely candidates of primary instability. The influence of curvature on secondary instability is largely indirect but most probably significant, through modulation of the primary disturbance amplitude. Subharmonic secondary instability is shown to be predominantly inviscid in nature, and to account for spikes in the Reynolds stress components at or near the critical layer

Sipping Fuel and Saving Lives: Increasing Fuel Economy without Sacrificing Safety

Demonstrates how new fuel-efficiency technologies make it possible, and advisable, to significantly increase the fuel economy of motor vehicles without compromising their safety

Collaborative Caring: Stories and Reflections on Teamwork in Health Care

[Excerpt] There are many theoretical and conceptual books and countless articles that have explored issues of teamwork in general and teamwork in health care in particular. The editors, and many of the authors in this book, have read most, and have even written some of them. To tackle the issue of teamwork, we have, however, taken a different approach. Rather than write a theoretical book about what teamwork is, what it is not, where it exists in health care, what barriers prevent its implementation and how they can be removed, we have chosen instead to address these questions through narratives and reflections that vividly describe good teamwork as well as problems in creating, leading, and working on genuine teams. What we believe is too often lacking in the literature is a clear and compelling picture of what teamwork looks like on the ground, in the institutions where health care work is delivered and where teams play well, or don\u27t play well, on a daily basis. The question we ask here is thus: What is the state of play in most health care institutions? To describe the state of play, we have asked clinicians to write what we think of as where the rubber hits the road stories or reflections about the nature of teamwork in their own particular work setting. To gather these stories, we talked to many people in different health care disciplines. In the invitation for submissions we wrote the following: We are seeking short, concise narratives that describe a concrete example in which you personally have been involved. The idea here is not to focus so much on the individual doctor-patient, nurse-patient, therapist-patient communication but the teamwork that was involved in ensuring that the standard of care was met or exceeded. If the patient or family was involved, so much the better. Stories can deal with interprofessional or intraprofessional teamwork. On balance, we would prefer to have more stories about interprofessional or occupational teamwork. Nonetheless, we recognize that interprofessional work depends on the ability to create teamwork within an occupation or profession. Stories involving support staff, such as housekeepers who spoke up about a patient safety issue, are definitely within the purview of this book. We would also welcome personal reflections that would enhance our understanding of either how to produce genuine teamwork or the obstacles that stand in its way

Comparative genome analysis reveals a conserved family of actin-like proteins in apicomplexan parasites

BACKGROUND: The phylum Apicomplexa is an early-branching eukaryotic lineage that contains a number of important human and animal pathogens. Their complex life cycles and unique cytoskeletal features distinguish them from other model eukaryotes. Apicomplexans rely on actin-based motility for cell invasion, yet the regulation of this system remains largely unknown. Consequently, we focused our efforts on identifying actin-related proteins in the recently completed genomes of Toxoplasma gondii, Plasmodium spp., Cryptosporidium spp., and Theileria spp. RESULTS: Comparative genomic and phylogenetic studies of apicomplexan genomes reveals that most contain only a single conventional actin and yet they each have 8–10 additional actin-related proteins. Among these are a highly conserved Arp1 protein (likely part of a conserved dynactin complex), and Arp4 and Arp6 homologues (subunits of the chromatin-remodeling machinery). In contrast, apicomplexans lack canonical Arp2 or Arp3 proteins, suggesting they lost the Arp2/3 actin polymerization complex on their evolutionary path towards intracellular parasitism. Seven of these actin-like proteins (ALPs) are novel to apicomplexans. They show no phylogenetic associations to the known Arp groups and likely serve functions specific to this important group of intracellular parasites. CONCLUSION: The large diversity of actin-like proteins in apicomplexans suggests that the actin protein family has diverged to fulfill various roles in the unique biology of intracellular parasites. Conserved Arps likely participate in vesicular transport and gene expression, while apicomplexan-specific ALPs may control unique biological traits such as actin-based gliding motility

Isospectral deformations of closed Riemannian manifolds with different scalar curvature

We construct the first examples of continuous families of isospectral Riemannian metrics that are not locally isometric on closed manifolds, more precisely, on $S^n\times T^m$, where $T^m$ is a torus of dimension $m\ge 2$ and $S^n$ is a sphere of dimension $n\ge 4$. These metrics are not locally homogeneous; in particular, the scalar curvature of each metric is nonconstant. For some of the deformations, the maximum scalar curvature changes during the deformation.Comment: amstex, 10 pages, no figure

Bronchial Circulation Angiogenesis in the Rat Quantified with SPECT and Micro-CT

Introduction As pulmonary artery obstruction results in proliferation of the bronchial circulation in a variety of species, we investigated this angiogenic response using single photon emission computed tomography (SPECT) and micro-CT. Materials and methods After surgical ligation of the left pulmonary artery of rats, they were imaged at 10, 20, or 40 days post-ligation. Before imaging, technetium-labeled macroaggregated albumin (99mTc MAA) was injected into the aortic arch (IA) labeling the systemic circulation. SPECT/micro-CT imaging was performed, the image volumes were registered, and activity in the left lung via the bronchial circulation was used as a marker of bronchial blood flow. To calibrate and to verify successful ligation, 99mTc MAA was subsequently injected into the left femoral vein (IV), resulting in accumulation within the pulmonary circulation. The rats were reimaged, and the ratio of the IA to the IV measurements reflected the fraction of cardiac output (CO) to the left lung via the bronchial circulation. Control and sham-operated rats were studied similarly. Results The left lung bronchial circulation of the control group was 2.5% of CO. The sham-operated rats showed no significant difference from the control. However, 20 and 40 days post-ligation, the bronchial circulation blood flow had increased to 7.9 and 13.9%, respectively, of CO. Excised lungs examined after barium filling of the systemic vasculature confirmed neovascularization as evidenced by tortuous vessels arising from the mediastinum and bronchial circulation. Conclusion Thus, we conclude that SPECT/micro-CT imaging is a valuable methodology for monitoring angiogenesis in the lung and, potentially, for evaluating the effects of pro- or anti-angiogenic treatments using a similar approach