459 research outputs found
Parallel processors and nonlinear structural dynamics algorithms and software
The adaptation of a finite element program with explicit time integration to a massively parallel SIMD (single instruction multiple data) computer, the CONNECTION Machine is described. The adaptation required the development of a new algorithm, called the exchange algorithm, in which all nodal variables are allocated to the element with an exchange of nodal forces at each time step. The architectural and C* programming language features of the CONNECTION Machine are also summarized. Various alternate data structures and associated algorithms for nonlinear finite element analysis are discussed and compared. Results are presented which demonstrate that the CONNECTION Machine is capable of outperforming the CRAY XMP/14
Enabling Advanced Wind-Tunnel Research Methods Using the NASA Langley 12-Foot Low Speed Tunnel
Design of Experiment (DOE) testing methods were used to gather wind tunnel data characterizing the aerodynamic and propulsion forces and moments acting on a complex vehicle configuration with 10 motor-driven propellers, 9 control surfaces, a tilt wing, and a tilt tail. This paper describes the potential benefits and practical implications of using DOE methods for wind tunnel testing - with an emphasis on describing how it can affect model hardware, facility hardware, and software for control and data acquisition. With up to 23 independent variables (19 model and 2 tunnel) for some vehicle configurations, this recent test also provides an excellent example of using DOE methods to assess critical coupling effects in a reasonable timeframe for complex vehicle configurations. Results for an exploratory test using conventional angle of attack sweeps to assess aerodynamic hysteresis is summarized, and DOE results are presented for an exploratory test used to set the data sampling time for the overall test. DOE results are also shown for one production test characterizing normal force in the Cruise mode for the vehicle
Dietary salt intake and discretionary salt use in two general population samples in Australia: 2011 and 2014
The limited Australian measures to reduce population sodium intake through national initiatives targeting sodium in the food supply have not been evaluated. The aim was, thus, to assess if there has been a change in salt intake and discretionary salt use between 2011 and 2014 in the state of Victoria, Australia. Adults drawn from a population sample provided 24 h urine collections and reported discretionary salt use in 2011 and 2014. The final sample included 307 subjects who participated in both surveys, 291 who participated in 2011 only, and 135 subjects who participated in 2014 only. Analysis included adjustment for age, gender, metropolitan area, weekend collection and participation in both surveys, where appropriate. In 2011, 598 participants: 53% female, age 57.1(12.0)(SD) years and in 2014, 442 participants: 53% female, age 61.2(10.7) years provided valid urine collections, with no difference in the mean urinary salt excretion between 2011: 7.9 (7.6, 8.2) (95% CI) g/salt/day and 2014: 7.8 (7.5, 8.1) g/salt/day (p = 0.589), and no difference in discretionary salt use: 35% (2011) and 36% (2014) reported adding salt sometimes or often/always at the table (p = 0.76). Those that sometimes or often/always added salt at the table and when cooking had 0.7 (0.7, 0.8) g/salt/day (p = 0.0016) higher salt excretion. There is no indication over this 3-year period that national salt reduction initiatives targeting the food supply have resulted in a population reduction in salt intake. More concerted efforts are required to reduce the salt content of manufactured foods, together with a consumer education campaign targeting the use of discretionary salt
Determinants of motion picture box office and profitability: an interrelationship approach’,
Abstract Producing and marketing motion pictures is notoriously risky, with only three out of ten movies breaking even and one becoming profitable at the box office. Extending knowledge on the factors that influence a movie's box-office and on the interrelations between these factors can be seen as major contribution to aid in lowering the number of failures in the motion picture industry. The major aim of this study is to distinguish direct and indirect effects between potential success drivers and motion picture success by understanding the interrelationships among different determinants of movie success. Hypotheses are developed with regard to the relationships among a number of factors that have been shown to impact motion-picture box office as well as movie profitability. Applying path analysis, which allows a simultaneous testing of factor interrelations, the hypotheses are subsequently tested against a sample of 331 movies
A 2-step approach to myeloablative haploidentical stem cell transplantation: a phase 1/2 trial performed with optimized T-cell dosing.
Studies of haploidentical hematopoietic stem cell transplantation (HSCT) have identified threshold doses of T cells below which severe GVHD is usually absent. However, little is known regarding optimal T-cell dosing as it relates to engraftment, immune reconstitution, and relapse. To begin to address this question, we developed a 2-step myeloablative approach to haploidentical HSCT in which 27 patients conditioned with total body irradiation (TBI) were given a fixed dose of donor T cells (HSCT step 1), followed by cyclophosphamide (CY) for T-cell tolerization. A CD34-selected HSC product (HSCT step 2) was infused after CY. A dose of 2 × 10(8)/kg of T cells resulted in consistent engraftment, immune reconstitution, and acceptable rates of GVHD. Cumulative incidences of grade III-IV GVHD, nonrelapse mortality (NRM), and relapse-related mortality were 7.4%, 22.2%, and 29.6%, respectively. With a follow-up of 28-56 months, the 3-year probability of overall survival for the whole cohort is 48% and 75% in patients without disease at HSCT. In the context of CY tolerization, a high, fixed dose of haploidentical T cells was associated with encouraging outcomes, especially in good-risk patients, and can serve as the basis for further exploration and optimization of this 2-step approach. This study is registered at www.clinicaltrials.gov as NCT00429143
Shared, plural and cultural values of ecosystems:UK National Ecosystem Assessment Follow-on Work Package Report 6
Shared, plural and cultural values of ecosystems:UK National Ecosystem Assessment Follow-on Work Package Report 6
Shared values and deliberative valuation:Future directions
Valuation that focuses only on individual values evades the substantial collective and intersubjective meanings, significance and value from ecosystems. Shared, plural and cultural values of ecosystems constitute a diffuse and interdisciplinary field of research, covering an area that links questions around value ontology, elicitation and aggregation with questions of participation, ethics, and social justice. Synthesising understanding from various contributions to this Special Issue of Ecosystem Services, and with a particular focus on deliberation and deliberative valuation, we discuss key findings and present 35 future research questions in eight topic areas: 1) the ontology of shared values; 2) the role of catalyst and conflict points; 3) shared values and cultural ecosystem services; 4) transcendental values; 5) the process and outcomes of deliberation; 6) deliberative monetary valuation; 7) value aggregation, meta-values and ‘rules of the game’; and 8) integrating valuation methods. The results of this Special Issue and these key questions can help develop a more extensive evidence base to mature the area and develop environmental valuation into a more pluralistic, comprehensive, robust, legitimate and effective way of safeguarding ecosystems and their services for the future
A Targeted Conservation Approach for Improving Environmental Quality: Multiple Benefits and Expanded Opportunities
Find out how targeted conservation practices can have the most impact on environmental quality while causing only a small change in overall agricultural production. Environmental benefits are discussed related to clean air and water, productive soils, diverse wildlife and plant habitat, and biological controls for crop protection.https://lib.dr.iastate.edu/extension_ag_pubs/1084/thumbnail.jp
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