Single-strain-gage force/stiffness buckling prediction techniques on a hat-stiffened panel

Predicting the buckling characteristics of a test panel is necessary to ensure panel integrity during a test program. A single-strain-gage buckling prediction method was developed on a hat-stiffened, monolithic titanium buckling panel. The method is an adaptation of the original force/stiffness method which requires back-to-back gages. The single-gage method was developed because the test panel did not have back-to-back gages. The method was used to predict buckling loads and temperatures under various heating and loading conditions. The results correlated well with a finite element buckling analysis. The single-gage force/stiffness method was a valid real-time and post-test buckling prediction technique

Thermal-structural panel buckling tests

The buckling characteristics of a titanium matrix composite hat-stiffened panel were experimentally examined for various combinations of thermal and mechanical loads. Panel failure was prevented by maintaining the applied loads below real-time critical buckling predictions. The test techniques used to apply the loads, minimize boundary were shown to compare well with a finite-element buckling analysis for previous panels. Comparisons between test predictions and analysis for this panel are ongoing

Best Practices for Training the Structures Flight Test Engineer

The Structures Flight from 412th Test Wing and the Aerostructures Branch at NASA Armstrong Flight Research Center at Edwards Air Force Base have developed a set of best practices for training a structures flight test engineer. These practices represent the hard-won lessons learned and best practices from training generations of engineers to perform high risk envelope expansion and developmental flight test. Collectively, these organizations have tested many of the world's most advanced and innovative aircraft, including the B-2, C-17, F-22, F-35, RQ-4, X-29, F-18 High Angle of Attack Research Vehicle, X-53, G-III Adaptive Compliant Trailing Edge, and X-56

Titanium Honeycomb Panel Testing

Thermal-mechanical tests were performed on a titanium honeycomb sandwich panel to experimentally validate the hypersonic wing panel concept and compare test data with analysis. Details of the test article, test fixture development, instrumentation, and test results are presented. After extensive testing to 900 deg. F, non-destructive evaluation of the panel has not detected any significant structural degradation caused by the applied thermal-mechanical loads

Consensus Statement on the Terminology and Classification of Central Neck Dissection for Thyroid Cancer

Background: The primary goals of this interdisciplinary consensus statement are to review the relevant anatomy of the central neck compartment, to identify the nodal subgroups within the central compartment commonly involved in thyroid cancer, and to define a consistent terminology relevant to the central compartment neck dissection. Summary: The most commonly involved central lymph nodes in thyroid carcinoma are the prelaryngeal (Delphian), pretracheal, and the right and left paratracheal nodal basins. A central neck dissection includes comprehensive, compartment-oriented removal of the prelaryngeal and pretracheal nodes and at least one paratracheal lymph node basin. A designation should be made as to whether a unilateral or bilateral dissection is performed and on which side (left or right) in unilateral cases. Lymph node plucking or berry picking implies removal only of the clinically involved nodes rather than a complete nodal group within the compartment and is not recommended. A therapeutic central compartment neck dissection implies that nodal metastasis is apparent clinically (preoperatively or intraoperatively) or by imaging (clinically N1a). A prophylactic/elective central compartment dissection implies nodal metastasis is not detected clinically or by imaging (clinically N0). Conclusion: Central neck dissection at a minimum should consist of removal of the prelaryngeal, pretracheal, and paratracheal lymph nodes. The description of a central neck dissection should include both the indication (therapeutic vs. prophylactic/elective) and the extent of the dissection (unilateral or bilateral).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78103/1/thy.2009.0159.pd

Cultural theory and the dynamics of organizational change: the response of housing associations in London to the Housing Act 1988

The aim of this article is to consider the most effective way of conceptualizing a sector that has undergone radical change: the UK voluntary housing sector. The article considers existing accounts of housing associations and classifies these into five analytically distinct groups: practitioners, historical accounts, managerialist approaches, network theorists and institutionalist accounts. The main contention is that each of these is limited in explanatory potential, primarily due to their neglect of culture. This article proposes a more detailed framework for developing an understanding of the substantial changes affecting housing associations since the 1980s; that offered by "grid-group cultural theory". The article provides longitudinal qualitative data obtained from London housing associations to support the contention that organizational change can most usefully be understood by reference to the cultural themes of hierarchy and individualism. The article contends that cultural theory offers the opportunity to develop a systematic analysis that accounts for institutional history and organizational differentiation

American Head and Neck Society Endocrine Section clinical consensus statement: North American quality statements and evidence‐based multidisciplinary workflow algorithms for the evaluation and management of thyroid nodules

BackgroundCare for patients with thyroid nodules is complex and multidisciplinary, and research demonstrates variation in care. The objective was to develop clinical guidelines and quality metrics to reduce unwarranted variation and improve quality.MethodsMultidisciplinary expert consensus and modified Delphi approach. Source documents were workflow algorithms from Kaiser Permanente Northern California and Cancer Care of Ontario based on the 2015 American Thyroid Association management guidelines for adult patients with thyroid nodules and differentiated thyroid cancer.ResultsA consensus‐based, unified preoperative, perioperative, and postoperative workflow was developed for North American use. Twenty‐one panelists achieved consensus on 16 statements about workflow‐embedded process and outcomes metrics addressing safety, access, appropriateness, efficiency, effectiveness, and patient centeredness of care.ConclusionA panel of Canadian and United States experts achieved consensus on workflows and quality metric statements to help reduce unwarranted variation in care, improving overall quality of care for patients diagnosed with thyroid nodules.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/148340/1/hed25526_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/148340/2/hed25526.pd

Low CCR7-Mediated Migration of Human Monocyte Derived Dendritic Cells in Response to Human Respiratory Syncytial Virus and Human Metapneumovirus

Human respiratory syncytial virus (HRSV) and, to a lesser extent, human metapneumovirus (HMPV) and human parainfluenza virus type 3 (HPIV3), can re-infect symptomatically throughout life without significant antigenic change, suggestive of incomplete or short-lived immunity. In contrast, re-infection by influenza A virus (IAV) largely depends on antigenic change, suggestive of more complete immunity. Antigen presentation by dendritic cells (DC) is critical in initiating the adaptive immune response. Antigen uptake by DC induces maturational changes that include decreased expression of the chemokine receptors CCR1, CCR2, and CCR5 that maintain DC residence in peripheral tissues, and increased expression of CCR7 that mediates the migration of antigen-bearing DC to lymphatic tissue. We stimulated human monocyte-derived DC (MDDC) with virus and found that, in contrast to HPIV3 and IAV, HMPV and HRSV did not efficiently decrease CCR1, 2, and 5 expression, and did not efficiently increase CCR7 expression. Consistent with the differences in CCR7 mRNA and protein expression, MDDC stimulated with HRSV or HMPV migrated less efficiently to the CCR7 ligand CCL19 than did IAV-stimulated MDDC. Using GFP-expressing recombinant virus, we showed that the subpopulation of MDDC that was robustly infected with HRSV was particularly inefficient in chemokine receptor modulation. HMPV- or HRSV-stimulated MDDC responded to secondary stimulation with bacterial lipopolysaccharide or with a cocktail of proinflammatory cytokines by increasing CCR7 and decreasing CCR1, 2 and 5 expression, and by more efficient migration to CCL19, suggesting that HMPV and HRSV suboptimally stimulate rather than irreversibly inhibit MDDC migration. This also suggests that the low concentration of proinflammatory cytokines released from HRSV- and HMPV-stimulated MDDC is partly responsible for the low CCR7-mediated migration. We propose that inefficient migration of HRSV- and HMPV-stimulated DC to lymphatic tissue contributes to reduced adaptive responses to these viruses

Perceived barriers to the regionalization of adult critical care in the United States: a qualitative preliminary study

<p>Abstract</p> <p>Background</p> <p>Regionalization of adult critical care services may improve outcomes for critically ill patients. We sought to develop a framework for understanding clinician attitudes toward regionalization and potential barriers to developing a tiered, regionalized system of care in the United States.</p> <p>Methods</p> <p>We performed a qualitative study using semi-structured interviews of critical care stakeholders in the United States, including physicians, nurses and hospital administrators. Stakeholders were identified from a stratified-random sample of United States general medical and surgical hospitals. Key barriers and potential solutions were identified by performing content analysis of the interview transcriptions.</p> <p>Results</p> <p>We interviewed 30 stakeholders from 24 different hospitals, representing a broad range of hospital locations and sizes. Key barriers to regionalization included personal and economic strain on families, loss of autonomy on the part of referring physicians and hospitals, loss of revenue on the part of referring physicians and hospitals, the potential to worsen outcomes at small hospitals by limiting services, and the potential to overwhelm large hospitals. Improving communication between destination and source hospitals, provider education, instituting voluntary objective criteria to become a designated referral center, and mechanisms to feed back patients and revenue to source hospitals were identified as potential solutions to some of these barriers.</p> <p>Conclusion</p> <p>Regionalization efforts will be met with significant conceptual and structural barriers. These data provide a foundation for future research and can be used to inform policy decisions regarding the design and implementation of a regionalized system of critical care.</p

First Dating of a Recombination Event in Mammalian Tick-Borne Flaviviruses

The mammalian tick-borne flavivirus group (MTBFG) contains viruses associated with important human and animal diseases such as encephalitis and hemorrhagic fever. In contrast to mosquito-borne flaviviruses where recombination events are frequent, the evolutionary dynamic within the MTBFG was believed to be essentially clonal. This assumption was challenged with the recent report of several homologous recombinations within the Tick-borne encephalitis virus (TBEV). We performed a thorough analysis of publicly available genomes in this group and found no compelling evidence for the previously identified recombinations. However, our results show for the first time that demonstrable recombination (i.e., with large statistical support and strong phylogenetic evidences) has occurred in the MTBFG, more specifically within the Louping ill virus lineage. Putative parents, recombinant strains and breakpoints were further tested for statistical significance using phylogenetic methods. We investigated the time of divergence between the recombinant and parental strains in a Bayesian framework. The recombination was estimated to have occurred during a window of 282 to 76 years before the present. By unravelling the temporal setting of the event, we adduce hypotheses about the ecological conditions that could account for the observed recombination