2,992 research outputs found

    Vibration analysis of the SA349/2 helicopter

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    Helicopter airframe vibration is examined using calculations and measurements for the SA349/2 research helicopter. The hub loads, which transmit excitations to the fuselage, are predicted using a comprehensive rotorcraft analysis and correlated with measuring hub loads. The predicted and measured hub loads are then coupled with finite element models representing the SA349/2 fuselage. The resulting vertical acceleration at the pilot seat is examined. Adjustments are made to the airframe structural models to examine the sensitivity of predicted vertical acceleration to the model. Changes of a few percent to the damping and frequency of specific models lead to large reductions in predicted vibration, and to major improvements in the correlations with measured pilot-seat vertical acceleration

    Funding the Extraordinary: An Evaluation of The Kresge Foundation Arts and Culture Program's Institutional Capitalization Grantmaking

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    In undertaking an assessment of Kresge's Capitalization Program, NFF applied its own high-level framework to help answer Kresge's primary research questions and assess the progress of each grantee in meeting its stated capital targets. NFF has found that effective capitalization in the nonprofit sector requires attention to three key financial priorities: liquidity, adaptability and durability:1. Liquidity: Does the organization have adequate cash to meet its operating needs?2. Adaptability: Does the organization have flexible funds that allow it to make adjustments as circumstances change?3. Durability: Does the organization have sufficient resources to address the range of needs that it may face in future years?NFF's review of Kresge's grantees sought to assess capitalization by looking for evidence of organizational progress in building liquid funds for immediate operating needs, as well as longer-term balance sheet savings for adaptability and durability. NFF's evaluation of grantees involved a combination of data analysis and interviews

    Novel methods to estimate antiretroviral adherence: protocol for a longitudinal study.

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    BackgroundThere is currently no gold standard for assessing antiretroviral (ARV) adherence, so researchers often resort to the most feasible and cost-effective methods possible (eg, self-report), which may be biased or inaccurate. The goal of our study was to evaluate the feasibility and acceptability of innovative and remote methods to estimate ARV adherence, which can potentially be conducted with less time and financial resources in a wide range of clinic and research settings. Here, we describe the research protocol for studying these novel methods and some lessons learned.MethodsThe 6-month pilot study aimed to examine the feasibility and acceptability of a remotely conducted study to evaluate the correlation between: 1) text-messaged photographs of pharmacy refill dates for refill-based adherence; 2) text-messaged photographs of pills for pill count-based adherence; and 3) home-collected hair sample measures of ARV concentration for pharmacologic-based adherence. Participants were sent monthly automated text messages to collect refill dates and pill counts that were taken and sent via mobile telephone photographs, and hair collection kits every 2 months by mail. At the study end, feasibility was calculated by specific metrics, such as the receipt of hair samples and responses to text messages. Participants completed a quantitative survey and qualitative exit interviews to examine the acceptability of these adherence evaluation methods. The relationship between the 3 novel metrics of adherence and self-reported adherence will be assessed.DiscussionInvestigators conducting adherence research are often limited to using either self-reported adherence, which is subjective, biased, and often overestimated, or other more complex methods. Here, we describe the protocol for evaluating the feasibility and acceptability of 3 novel and remote methods of estimating adherence, with the aim of evaluating the relationships between them. Additionally, we note the lessons learned from the protocol implementation to date. We expect that these novel measures will be feasible and acceptable. The implications of this research will be the identification and evaluation of innovative and accurate metrics of ARV adherence for future implementation

    Ground State Properties and Glueball Spectrum in SU(2) Yang-Mills Theory using Gauge Invariant Variables

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    We describe a nonperturbative calculation of the spectrum of SU(2) Yang-Mills theory based on a Hamiltonian formulation. Our approach exploits gauge invariant variables similar to those used in nuclear physics to describe collective motion in nuclei.Comment: 18 pages Late

    A Pilot Study to Examine the Disparities in Water Quality between Predominantly Haitian Neighborhoods and Dominican Neighborhoods in Two Cities in the Dominican Republic

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    Abstract: Worldwide, diarrheal disease is a leading cause of death affecting over 1.7 million individuals annually. Much of this can be attributed to lack of clean water, sanitation and hygiene. Nearly all of these deaths occur in countries with developing economies. This public health problem is apparent in the island of Hispaniola; the island that is shared by Haiti and the Dominican Republic. Significant gaps in income between the countries have resulted in Haitians migrating into the Dominican Republic. While there has been increased migration into the Dominican Republic, many of the neighborhoods remain segregated. A cross-sectional analysis was conducted at 49 sites in the Dominican Republic. Samples were classified as being from a Haitian neighborhood or Dominican neighborhood and analyzed for microbial contamination. Overall, Haitian neighborhoods were found to have statistically significantly higher levels of contamination of both coliform and E. coli. The odds of having E. coli contaminated water in Haitian neighborhoods are 4.25 times as high as Dominican neighborhoods. The odds of having coliform contaminated water in Haitian neighborhoods are 4.78 times as high as Dominican neighborhoods. This study provides evidence of the disparity in access to clean drinking water for Haitian immigrants and highlights the need for further investigation

    Intragenic alternative splicing coordination is essential for Caenorhabditis elegans slo-1 gene function

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    Alternative splicing is critical for diversifying eukaryotic proteomes, but the rules governing and coordinating splicing events among multiple alternate splice sites within individual genes are not well understood. We developed a quantitative PCR-based strategy to quantify the expression of the 12 transcripts encoded by the Caenorhabditis elegans slo-1 gene, containing three alternate splice sites. Using conditional probability-based models, we show that splicing events are coordinated across these sites. Further, we identify a point mutation in an intron adjacent to one alternate splice site that disrupts alternative splicing at all three sites. This mutation leads to aberrant synaptic transmission at the neuromuscular junction. In a genomic survey, we found that a UAAAUC element disrupted by this mutation is enriched in introns flanking alternate exons in genes with multiple alternate splice sites. These results establish that proper coordination of intragenic alternative splicing is essential for normal physiology of slo-1 in vivo and identify putative specialized cis-regulatory elements that regulate the coordination of intragenic alternative splicing

    Webliography of African-American Champaign-Urbana

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    This Lab Note reflects one part of a year-long project called eBlackChampaign-Urbana. Our interest here is to provide better access to the dispersed documentation of local African-American history and culture in Champaign-Urbana, using digital technology to aggregate and enliven historical and contemporary information. Although this webliography focuses primarily on substantial, in-depth texts documenting local African-American life, we are also aggregating into the eBlackCU.net website URLs for local African-American websites, facebook pages, photographs, newspaper clippings, flyers, posters and other ephemeral documentation of Champaign-Urbana's Black heritage. All are welcome to help us fill in gaps in this webliography and in our website by visiting http://eBlackCU.net/portal/contribution and adding files, citations, photographs, movies and memories of African-American life in Champaign-UrbanaOpe

    Dynamics of cold bosons in optical lattices: Effects of higher Bloch bands

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    The extended effective multiorbital Bose-Hubbard-type Hamiltonian which takes into account higher Bloch bands, is discussed for boson systems in optical lattices, with emphasis on dynamical properties, in relation with current experiments. It is shown that the renormalization of Hamiltonian parameters depends on the dimension of the problem studied. Therefore, mean field phase diagrams do not scale with the coordination number of the lattice. The effect of Hamiltonian parameters renormalization on the dynamics in reduced one-dimensional optical lattice potential is analyzed. We study both the quasi-adiabatic quench through the superfluid-Mott insulator transition and the absorption spectroscopy, that is energy absorption rate when the lattice depth is periodically modulated.Comment: 23 corrected interesting pages, no Higgs boson insid

    Formative peer assessment in a CSCL environment

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    In this case study our aim was to gain more insight in the possibilities of qualitative formative peer assessment in a computer supported collaborative learning (CSCL) environment. An approach was chosen in which peer assessment was operationalised in assessment assignments and assessment tools that were embedded in the course material. The course concerned a higher education case-based virtual seminar, in which students were asked to conduct research and write a report in small multidisciplinary teams. The assessment assignments contained the discussion of assessment criteria, the assessment of a group report of a fellow group, and writing an assessment report. A list of feedback rules was one of the assessment tools. A qualitative oriented study was conducted, focussing on the attitude of students towards peer assessment and practical use of peer assessment assignments and tools. Results showed that students’ attitude towards peer assessment was positive and that assessment assignments had added value. However, not all students fulfilled all assessment assignments. Recommendations for implementation of peer assessment in CSCL environments as well as suggestions for future research are discussed
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