5,543 research outputs found

    The influence of joints and composite floor slabs on effective tying of steel structures in preventing progressive collapse

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    The event of the terrorist attack at 11th September 2001 in the USA has attracted increasing attention of researchers and engineers on progressive collapse of structures. It has gradually become a general practice for engineers to consider progressive collapse resistance in their design. In this paper, progressive collapse of steel frames with composite floor slabs is simulated by the finite element method. The numerical results are compared with test results. The influence of the joints and the concrete slabs on the effective tying of steel beams is investigated through parametric studies. From the analysis, methods of preventing progressive collapse that can be considered in design and when retrofitting existing structures are proposed. The results show that retrofitting a structure with pre-stressed steel cables and an increase of crack resistance in the concrete near joints can effectively improve effective tying of a structure, which results in an enhanced structural capacity in preventing progressive collapse

    A linear matrix inequality (LMI) approach to robust H2 sampled-data control for linear uncertain systems

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    In this paper, we consider the H2 sampled-data control for uncertain linear systems by the impulse response interpretation of the H2 norm. Two H2 measures for sampled-data systems are considered. The robust optimal control procedures subject to these two H2 criteria are proposed. The development is primarily concerned with a multirate treatment in which a periodic time-varying robust optimal control for uncertain linear systems is presented. To facilitate multirate control design, a new result of stability of hybrid system is established. Moreover, the single-rate case is also obtained as a special case. The sampling period is explicitly involved in the result which is superior to traditional methods. The solution procedures proposed in this paper are formulated as an optimization problem subject to linear matrix inequalities. Finally, we present a numerical example to demonstrate the proposed techniques.published_or_final_versio

    IFN-gamma is associated with risk of Schistosoma japonicum infection in China.

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    Before the start of the schistosomiasis transmission season, 129 villagers resident on a Schistosoma japonicum-endemic island in Poyang Lake, Jiangxi Province, 64 of whom were stool-positive for S. japonicum eggs by the Kato method and 65 negative, were treated with praziquantel. Forty-five days later the 93 subjects who presented for follow-up were all stool-negative. Blood samples were collected from all 93 individuals. S. japonicum soluble worm antigen (SWAP) and soluble egg antigen (SEA) stimulated IL-4, IL-5 and IFN-gamma production in whole-blood cultures were measured by ELISA. All the subjects were interviewed nine times during the subsequent transmission season to estimate the intensity of their contact with potentially infective snail habitats, and the subjects were all re-screened for S. japonicum by the Kato method at the end of the transmission season. Fourteen subjects were found to be infected at that time. There was some indication that the risk of infection might be associated with gender (with females being at higher risk) and with the intensity of water contact, and there was evidence that levels of SEA-induced IFN-gamma production were associated with reduced risk of infection

    On the L

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    A nonlinear generalized Degasperis-Procesi equation is investigated. Assuming that the strong solution of the equation is bounded in the sense of L∞R-norm and the initial data belong to the space L1(R)∩L2(R), we prove that the solutions are stable in the space L1(R)

    Signal processing with Levy information

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    Levy processes, which have stationary independent increments, are ideal for modelling the various types of noise that can arise in communication channels. If a Levy process admits exponential moments, then there exists a parametric family of measure changes called Esscher transformations. If the parameter is replaced with an independent random variable, the true value of which represents a "message", then under the transformed measure the original Levy process takes on the character of an "information process". In this paper we develop a theory of such Levy information processes. The underlying Levy process, which we call the fiducial process, represents the "noise type". Each such noise type is capable of carrying a message of a certain specification. A number of examples are worked out in detail, including information processes of the Brownian, Poisson, gamma, variance gamma, negative binomial, inverse Gaussian, and normal inverse Gaussian type. Although in general there is no additive decomposition of information into signal and noise, one is led nevertheless for each noise type to a well-defined scheme for signal detection and enhancement relevant to a variety of practical situations.Comment: 27 pages. Version to appear in: Proc. R. Soc. London

    Hablamos Juntos (Together We Speak): Interpreters, Provider Communication, and Satisfaction with Care

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    The Hablamos Juntos—Together We Speak (HJ)—national demonstration project targeted the improvement of language access for Spanish-speaking Latinos in areas with rapidly growing Latino populations. The objective of HJ was to improve doctor-patient communication by increasing access to and quality of interpreter services for Spanish-speaking patients. To investigate how access to interpreters for adult Spanish-speaking Latinos is associated with ratings of doctor/office staff communication and satisfaction with care. Cross-sectional cohort study. A total of 1,590 Spanish-speaking Latino adults from eight sites across the United States who participated in the outpatient HJ evaluation. We analyzed two multi-item measures of doctor communication (4 items) and office staff helpfulness (2 items), and one global item of satisfaction with care by interpreter use. We performed regression analyses to control for patient sociodemographic characteristics, survey year, and clustering at the site of care. Ninety-five percent of participants were born outside the US, 81% were females, and survey response rates ranged from 45% to 85% across sites. In this cohort of Spanish-speaking patients, those who needed and always used interpreters reported better experiences with care than their counterparts who needed but had interpreters unavailable. Patients who always used an interpreter had better adjusted ratings of doctor communication [effect size (ES = 0.51)], office staff helpfulness (ES = 0.37), and satisfaction with care (ES = 0.37) than patients who needed but did not always use an interpreter. Patients who needed and always used interpreters also reported better experiences with care in all three domains measured [doctor communication (ES = 0.30), office staff helpfulness (ES = 0.21), and satisfaction with care (ES = 0.23)] than patients who did not need interpreters. Among adult Spanish-speaking Latinos, interpreter use is independently associated with higher satisfaction with doctor communication, office staff helpfulness, and ambulatory care. Increased attention to the need for effective interpreter services is warranted in areas with rapidly growing Spanish-speaking populations

    P5CS expression study in a new family with ALDH18A1-associated hereditary spastic paraplegia SPG9

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    In 2015\u20132016, we and others reported ALDH18A1 mutations causing dominant (SPG9A) or recessive (SPG9B) spastic paraplegia. In vitro production of the ALDH18A1 product, \u3941-pyrroline-5-carboxylate synthetase (P5CS), appeared necessary for cracking SPG9 disease-causing mechanisms. We now describe a baculovirus\u2013insect cell system that yields mgs of pure human P5CS and that has proven highly valuable with two novel P5CS mutations reported here in new SPG9B patients. We conclude that both mutations are disease-causing, that SPG9B associates with partial P5CS deficiency and that it is clinically more severe than SPG9A, as reflected in onset age, disability, cognitive status, growth, and dysmorphic traits

    Language Access Services for Latinos with Limited English Proficiency: Lessons Learned from Hablamos Juntos

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    BackgroundThe Robert Wood Johnson Foundation funded Hablamos Juntos (HJ), a $10-million multiyear demonstration to improve access to health care for Latinos with limited English proficiency and to explore cost-effective ways for health care organizations to provide language access services.Hablamos juntosIn this manuscript, the authors draw on their experiences in evaluating HJ, provide brief descriptions of innovative interventions, estimate operating costs, and synthesize lessons learned about implementation. A number of barriers and facilitators are documented.ConclusionThe experience of HJ grantees provides guidance for organizations contemplating similar efforts. In particular, it highlights the need for health care organizations to involve physicians in the design and adoption of language services

    Impacts of climate change on hydropower generation in China

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    Analyzing the impact of climate change on China's hydropower system can make great contribution to understanding the feedback mechanism of the climate change on energy system. In this work, an econometric model for regional hydropower generation is constructed to explore the impact of climate factors on hydropower generation in different regions of China by using the monthly panel data of 28 provinces in China. Further, we also make a prediction for the changes of hydropower generation in China caused by the changes of climatic factors under the three climate change scenarios (RCP2.6, RCP4.5 and RCP8.5) proposed in the Intergovernmental Panel on Climate Change's (IPCC) fifth assessment report. The results show that: (1) At the national level, the influences of climatic factors on hydropower generation are significant, the elasticity coefficients of rainfall, heating degree day (HDD), cooling degree day (CDD) and sunshine duration are 0.081, -0.016, 0.089 and -0.043 respectively. (2) The impacts of climatic factors on the hydropower generation in the northern and southern regions of China are different. The effect of rainfall on the hydropower generation is significant in the southern regions, but not in the northern region. The CDD has a significant effect on both the northern and southern regions, and the latter is greater (0.136%). The impact of HDD on the northern area is significant, while its influence on the southern area is not significant. The influence of sunshine duration is not significant in any region in China. (3) Compared with the year of 2011, the total changes of hydropower output caused by climate factors by 2100 under the RCP8.5, RCP4.5 and RCP2.6 scenarios are 153.29 billion kWh, 67.49 billion kWh and 22.10 billion kWh, respectively. The results imply that the hydropower is sensitive and vulnerable to climate fluctuation, leading to many uncertainties for its development in the future. Finally, some policy implications are proposed for the planning of hydropower in China
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