1,210 research outputs found

    Applying new uncertainty related theories and multicriteria decision analysis methods to snow avalanche risk management

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    International audienceMaking the best decision in the event of a snow avalanche encounters problems in the assessment and management process because of the lack of information and knowledge on natural phenomena and the heterogeneity and reliability of the information sources available (historical data, field measurements, and expert assessments). One major goal today is therefore to aid decision making by improving the quality, quantity, and reliability of the available information. This article presents a new method called evidential reasoning and multicriteria decision analysis (ER-MCDA) to help decision making by considering information imperfections arising from several more or less reliable and possibly conflicting sources of information. First, the principles of the existing methods are reviewed. Classical methods of multicriteria decision making and existing theories attempting to represent and propagate information imperfections are described. In a second point, we describe the principle of the ER-MCDA method combining multicriteria decision analysis (MCDA) to model the decision-making process and fuzzy sets theory, possibility theory, and evidence theory to represent, fuse and propagate information imperfections. Experts, considered more or less reliable, provide imprecise and uncertain evaluations of quantitative and qualitative criteria that are combined through information fusion. The method is applied to a simplified version of an existing system aiming to evaluate the sensitivity of avalanche sites. This new method makes it possible to consider both the importance of the information available and reliability in the decision process. It also contributes to improving traceability. Other developments designed to handle other assessment problems such as avalanche triggering conditions or data quality are in progress

    Response of Gestating Beef Cows to Limit-Fed Diets Containing Rolled Barley

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    In the Northern Great Plains, barley grain may be a more economical source of energy than hay. An experiment was conducted at South Dakota State University Cottonwood Research Station to determine the efficacy of limit-fed, barley-based diets as an alternative to alfalfa hay for beef cows in late gestation. Ninety-six gestating, crossbred cows (age 3 to 11 years; average calving date of May 7) were stratified by age and weight and randomly assigned to one of 12 pens (8 cows/pen). Pens were randomly allotted to one of three winter feeding treatments (4 pens/treatment) from January 15 to April 10, 2003. Treatments were: 1) course-ground alfalfa hay (Hay; fed at approximately 1.6% of BW); 2) dry rolled barley replacing alfalfa hay at 29% of the diet dry matter (Low Barley; fed at approximately 1.4% of BW); and 3) dry rolled barley replacing alfalfa hay at 67% of the diet dry matter (High Barley; fed at approximately 1.2% of BW). All diets were formulated using the 1996 NRC computer model to provide for maintenance of body condition score. A supplement (0.5 lb/d) supplied adequate protein, minerals, vitamins, and 200 mg/hd/d of Rumensin. Rations changed monthly to account for changing cow requirements during late gestation. All diets were consumed within a two-hour period each day. Treatment means were separated using orthogonal contrasts (Hay vs. High and Low Barley; High Barley vs. Low Barley). Cows fed barley gained more weight than cows fed Hay (P \u3c 0.01; weight change of 79, 126, and 132 lb for Hay, Low Barley, and High Barley, respectively). Cows fed barley also gained more body condition than cows fed Hay (P \u3c 0.01; body condition score change of -0.10, 0.24, and 0.38 for Hay, Low Barley, and High Barley, respectively). There were no differences (P \u3e 0.10) in weight or body condition score change between Low and High Barley treatments. There were no differences between treatments in subsequent pregnancy rates (P \u3e 0.50). Rolled barley can be used to replace alfalfa hay in diets for gestating beef cows

    Turbulence and suspended sediment measurements in an urban environment during the Brisbane River flood of January 2011

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    In urbanized areas, flood flows constitute a hazard to populations and infrastructure, as illustrated during major floods in 2011. During the 2011 Brisbane River flood, some turbulent velocity data were collected using acoustic Doppler velocimetry in an inundated street. The field deployment showed some unusual features of flood flow in the urban environment. That is, the water elevations and velocities fluctuated with distinctive periods between 50 and 100 s linked with some local topographic effects. The instantaneous velocity data were analyzed using a triple decomposition. The velocity fluctuations included a large energy component in the slow fluctuation range, whereas the turbulent motion components were much smaller. The suspended sediment data showed some significant longitudinal flux. Altogether, the results highlighted that the triple decomposition approach originally developed for periodic flows is well-suited to complicated flows in an inundated urban environment

    Advanced Configurations for Very Large Subsonic Transport Airplanes

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    Recent aerospace industry interest in developing a subsonic commercial transport airplane with 50 percent greater passenger capacity than the largest existing aircraft in this category (the Boeing 747-400 with approximately 400-450 seats) has generated a range of proposals based largely on the configuration paradigm established nearly 50 years ago with the Boeing B-47 bomber. While this basic configuration paradigm has come to dominate subsonic commercial airplane development since the advent of the Boeing 707/Douglas DC-8 in the mid-1950's, its extrapolation to the size required to carry more than 600-700 passengers raises several questions. To explore these and a number of related issues, a team of Boeing, university, and NASA engineers was formed under the auspices of the NASA Advanced Concepts Program. The results of a Research Analysis focused on a large, unconventional transport airplane configuration for which Boeing has applied for a patent are the subject of this report. It should be noted here that this study has been conducted independently of the Boeing New Large Airplane (NLA) program, and with the exception of some generic analysis tools which may be common to this effort and the NLA (as will be described later), no explicit Boeing NLA data other than that published in the open literature has been used in the conduct of the study reported here

    The Clinical Impact of [68Ga]‐DOTATATE PET/CT for the Diagnosis and Management of Ectopic Adrenocorticotropic Hormone – Secreting Tumours

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    ObjectivesLocalization of ectopic ACTH‐secreting tumours causing Cushing syndrome (ECS) is essential for clinical management, yet often difficult. [68Ga]‐DOTATATE PET/CT ([68Ga]‐DOTA‐(Tyr3)‐octreotate)] is an FDA‐approved high‐resolution diagnostic tool for imaging neuroendocrine tumours. Data on the clinical utility of [68Ga]‐DOTATATE in patients with ECS, however, are scarce. The objectives of this study were to determine the efficacy for ECS localization and the clinical benefit of [68Ga]‐DOTATATE imaging.MethodWe conducted a retrospective review of all cases with ECS evaluated with [68Ga]‐DOTATATE from November 2016 through October 2018 at three referral centres. The clinical benefit of [68Ga]‐DOTATATE was based on detection of new tumours and resultant changes in management.ResultsOver the study period, 28 patients with ECS underwent [68Ga]‐DOTATATE: 17 for identification of the primary tumour and 11 during follow‐up. [68Ga]‐DOTATATE identified the suspected primary ECS in 11/17 patients (65%). Of these, nine patients underwent surgery: eight with confirmed ECS (5 bronchial, 1 thymic, 1 pancreatic and 1 metastatic neuroendocrine tumour of unknown primary origin) and one patient with a false‐positive scan (adrenal gland). Of the 11 patients with ECS who underwent [68Ga]‐DOTATATE evaluation during follow‐up, the study led to changes in clinical management in 7/11 (64%) patients.Conclusions[68Ga]‐DOTATATE is sensitive in detecting primary and metastatic ECS, often identifies occult tumours after conventional imaging, and impacts clinical care in the majority of patients.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/150507/1/cen14008.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150507/2/cen14008_am.pd

    Highly potent HIV inhibition: engineering a key anti-HIV structure from PSC-RANTES into MIP-1β/CCL4

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    The HIV coreceptor CCR5 is a validated target for both the prevention and therapy of HIV infection. PSC-RANTES, an N-terminally modified analogue of one of the natural chemokine ligands of CCR5 (RANTES/CCL5), is a potent inhibitor of HIV entry into target cells. Here, we set out to engineer the anti-HIV activity of PSC-RANTES into another natural CCR5 ligand (MIP-1β/CCL4), by grafting into it the key N-terminal pharmacophore region from PSC-RANTES. We were able to identify MIP-1β/CCL4 analogues that retain the receptor binding profile of MIP-1β/CCL4, but acquire the very high anti-HIV potency and characteristic inhibitory mechanism of PSC-RANTES. Unexpectedly, we discovered that in addition to N-terminal structures from PSC-RANTES, the side chain of Lys33 is also necessary for full anti-HIV potenc

    Bayesian hierarchical clustering for studying cancer gene expression data with unknown statistics

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    Clustering analysis is an important tool in studying gene expression data. The Bayesian hierarchical clustering (BHC) algorithm can automatically infer the number of clusters and uses Bayesian model selection to improve clustering quality. In this paper, we present an extension of the BHC algorithm. Our Gaussian BHC (GBHC) algorithm represents data as a mixture of Gaussian distributions. It uses normal-gamma distribution as a conjugate prior on the mean and precision of each of the Gaussian components. We tested GBHC over 11 cancer and 3 synthetic datasets. The results on cancer datasets show that in sample clustering, GBHC on average produces a clustering partition that is more concordant with the ground truth than those obtained from other commonly used algorithms. Furthermore, GBHC frequently infers the number of clusters that is often close to the ground truth. In gene clustering, GBHC also produces a clustering partition that is more biologically plausible than several other state-of-the-art methods. This suggests GBHC as an alternative tool for studying gene expression data. The implementation of GBHC is available at https://sites. google.com/site/gaussianbhc
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