Home About us Contact
|
Home About us Contact | ||
|
|
||
Set Used (set + used)
Kinds of Set Used Selected AbstractsStructural performance assessment under near-source pulse-like ground motions using advanced ground motion intensity measuresEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 7 2008Polsak Tothong Abstract This paper demonstrates the effectiveness of utilizing advanced ground motion intensity measures (IMs) to evaluate the seismic performance of a structure subject to near-source ground motions. Ordinary records are, in addition, utilized to demonstrate the robustness of the advanced IM with respect to record selection and scaling. To perform nonlinear dynamic analyses (NDAs), ground motions need to be selected; as a result, choosing records that are not representative of the site hazard can alter the seismic performance of structures. The median collapse capacity (in terms of IM), for example, can be systematically dictated by including a few aggressive or benign pulse-like records into the record set used for analyses. In this paper, the elastic-based IM such as the pseudo-spectral acceleration (Sa) or a vector of Sa and epsilon has been demonstrated to be deficient to assess the structural responses subject to pulse-like motions. Using advanced IMs can be, however, more accurate in terms of probabilistic response prediction. Scaling earthquake records using advanced IMs (e.g. inelastic spectral displacement, Sdi, and IM1I&2E; the latter is for the significant higher-mode contribution structures) subject to ordinary and/or pulse-like records is efficient, sufficient, and robust relative to record selection and scaling. As a result, detailed record selection is not necessary, and records with virtually any magnitude, distance, epsilon and pulse period can be selected for NDAs. Copyright © 2008 John Wiley & Sons, Ltd. [source] Development and Validation of Quality Indicators for Dementia Diagnosis and Management in a Primary Care SettingJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 3 2010Marieke Perry MD OBJECTIVES: To construct a set of quality indicators (QIs) for dementia diagnosis and management in a primary care setting. DESIGN: RAND modified Delphi method, including a postal survey, a stakeholders consensus meeting, a scientific expert consensus meeting, and a demonstration project. SETTING: Primary care. PARTICIPANTS: General practitioners (GPs), primary care nurses (PCNs), and informal caregivers (ICs) in postal survey and stakeholders consensus meeting. Eight national dementia experts in scientific consensus meeting. Thirteen GPs in the demonstration project. MEASUREMENTS: Mean face validity and feasibility scores. Compliance rates using GPs' electronic medical record data. RESULTS: The initial set consisted of 31 QIs. Most indicators showed moderate or good face validity and feasibility scores. Consensus panels reduced the preliminary set used in the demonstration project to 24 QIs. The overall compliance to the QIs was 45.3%. Discriminative validity of the set was good; significant differences in adherence were found between GPs with high and low levels of patients aged 65 and older in their practice, with and without PCNs, and with positive and negative attitudes toward dementia (all P<.05). Based on the demonstration project, one QI was excluded. The final set consisted of 23 QIs; 15 QIs contained innovative quality criteria on collaboration between GPs and PCNs, referral criteria, and assessment of caregivers' needs. CONCLUSION: This new set of dementia QIs is feasible, reliable, and valid and can be used to improve primary dementia care. Because of the innovative quality criteria, the set is complementary to the existing dementia QIs. [source] Recognising subtidal foraminiferal assemblages: implications for quantitative sea-level reconstructions using a foraminifera-based transfer function,JOURNAL OF QUATERNARY SCIENCE, Issue 3 2009Sarah A. Woodroffe Abstract Microfossil-based transfer function models are increasingly used to provide decimeter-scale sea-level change reconstructions. In this paper I demonstrate that in the tropical location of northern Australia problems arise in selecting the appropriate elevation range for the modern training set used to calibrate fossil calcareous foraminiferal assemblages. Most calcareous foraminiferal species found in cores occur in both modern intertidal and shallow subtidal environments. A lack of independent measures to indicate whether fossil assemblages come from intertidal environments forces use of a training set that includes intertidal and subtidal environments. This results in decreased precision compared to using a training set solely from intertidal environments. The widely used method of assessing model fit to fossil assemblages (modern analogue technique) often fails to discriminate between acceptable and unacceptable reconstructions. It is important to investigate a number of different measures including modern analogue technique, canonical correspondence analysis and changing bootstrapped sample specific transfer function errors to fully understand the level of similarity between modern and fossil foraminiferal samples, to judge the reliability of transfer function-predicted sea-level reconstructions. Copyright © 2008 John Wiley & Sons, Ltd. [source] FT-Raman, FT-IR spectral and DFT studies on 6, 8-dichloroflavone and 6, 8-dibromoflavoneJOURNAL OF RAMAN SPECTROSCOPY, Issue 7 2010Yusuf Erdogdu Abstract In this study, experimental and theoretical vibrational spectral results of the molecular structures of 6,8-dichloroflavone (6,8-dcf) and 6,8-dibromoflavone (6,8-dbf) are presented. The FT-IR and FT-Raman spectra of the compounds have been recorded together between 4000 and 400 cm,1 and 3500,5 cm,1 regions, respectively. The molecular geometry and vibrational wavenumbers of 6,8-dcf and 6,8-dbf in their ground state have been calculated by using DFT/B3LYP functional, with 6-31 + + G(d,p) basis set used in calculations. All calculations were performed with Gaussian03 software. The obtained vibrational wavenumbers and optimized geometric parameters were seen to be in good agreement with the experimental data. Scale factors have been used in order to compare how the calculated and experimental data are in agreement. Theoretical infrared intensities are also reported. Copyright © 2009 John Wiley & Sons, Ltd. [source] Bayesian models for relative archaeological chronology buildingJOURNAL OF THE ROYAL STATISTICAL SOCIETY: SERIES C (APPLIED STATISTICS), Issue 4 2000Caitlin E. Buck For many years, archaeologists have postulated that the numbers of various artefact types found within excavated features should give insight about their relative dates of deposition even when stratigraphic information is not present. A typical data set used in such studies can be reported as a cross-classification table (often called an abundance matrix or, equivalently, a contingency table) of excavated features against artefact types. Each entry of the table represents the number of a particular artefact type found in a particular archaeological feature. Methodologies for attempting to identify temporal sequences on the basis of such data are commonly referred to as seriation techniques. Several different procedures for seriation including both parametric and non-parametric statistics have been used in an attempt to reconstruct relative chronological orders on the basis of such contingency tables. We develop some possible model-based approaches that might be used to aid in relative, archaeological chronology building. We use the recently developed Markov chain Monte Carlo method based on Langevin diffusions to fit some of the models proposed. Predictive Bayesian model choice techniques are then employed to ascertain which of the models that we develop are most plausible. We analyse two data sets taken from the literature on archaeological seriation. [source] Residual Autocorrelation Distribution in the Validation Data SetJOURNAL OF TIME SERIES ANALYSIS, Issue 2 2000Alessandro Fasso Testing model performance on a data set other than the data set used for estimation is common practice in econometrics, technological stochastic modelling and environmetrics. In this paper, using an ARMAX model, the asymptotic distribution of the residual autocorrelations in the validation data set is given and a ,2 test for overall residual incorrelation is considered. [source] Pattern of Flower and Fruit Production in Stryphnodendron adstringens, an Andromonoecious Legume Tree of Central BrazilPLANT BIOLOGY, Issue 6 2003P. L. Ortiz Abstract: Patterns of flower and fruit production in racemes of Stryphnodendron adstringens, an andromonoecious Brazilian savanna tree species, were studied in two natural areas near Uberlāndia-MG. Racemes were divided in three parts: apex, centre, and base. Number of flowers, gender, and nectar and pollen production were analyzed for each section. Frequency of visitors to each part of the inflorescence was also quantified. Hand self- and cross-pollinations were performed in complete racemes and fruit set used to determine breeding system. The racemes produced a mean of 329 flowers, more densely packed in the central portion. Hermaphrodite and male flowers occur along the inflorescence but hermaphrodite flowers are more common in the centre. Fruit set was markedly low but does not seem to be limited by pollination service, since free open-pollinated racemes and hand cross-pollinated ones do not differ in fruit production rates. Fruits resulted mostly from cross-pollinated flowers and fruit production was biased to the central portion of the raceme. Nectar yield was higher in the central portion of the raceme and visitors arrived more commonly on this portion of the inflorescence. However, most flowers did not produce nectar. The pattern of fruit production seems to be a consequence of the hermaphrodite flower distribution in the raceme and it is not constrained by pollen flow or flower opening sequence. [source] Open-loop Analysis of Transfer Characteristics from Blood Pressure to Heart Rate Using an Effectively Total Artificial HeartARTIFICIAL ORGANS, Issue 1 2004Akira Tanaka Abstract:, ,It is desirable for the dynamic behavior of the drive rate of the artificial heart to be as similar as possible to that of the recipient's heart rate (HR) before implantation. This requires a model which can simulate the behavior of HR on the basis of only the information measured with the limited number of approvable implanted sensors. This article provides a linear time series model for explaining the behavior of HR only with aortic pressure and right atrial pressure. This could be obtained from open-loop analysis using a total artificial heart, which was introduced for measuring HR in vivo and for eliminating its effect on blood pressure. The model was identified in a goat equipped with a special biventricular assist device called the effectively total artificial heart (ETAH). The ETAH was introduced to make an open loop and awake situation in the animal with almost intact autonomic nerves, which could enhance the accuracy and reliability of the identification of the model. The adequacy of the proposed model was ascertained in several data sets measured in two goats, which were different from the data set used for identification. Most of the mean estimation errors were less than 3 beats/min and auto-correlation analysis showed approvable statistical appropriateness. However, it was clarified through comparison with the 1/R control method that the proposed model has a few problems still to be solved before its future implementation as an automatic controller of the TAH. [source] Solar-induced and internal climate variability at decadal time scalesINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 6 2005Mihai Dima Abstract Statistical analyses of long-term instrumental and proxy data emphasize a distinction between two quasi-decadal modes of climate variability. One mode is linked to atmosphere,ocean interactions (,the internal mode') and the other one is associated with the solar sunspots cycle (,the solar mode'). The distinct signatures of these two modes are also detected in a high-resolution sediment core located in the Cariaco basin. In the oceanic surface temperature the internal mode explains about three times more variance than the solar mode. In contrast, the solar mode dominates over the internal mode in the sea-level pressure and upper atmospheric fields. The heterogeneous methods and data sets used in this study underline the distinction between these decadal modes and enable estimation of their relative importance. The distinction between these modes is important for the understanding of climate variability, the recent global warming trend and the interpretation of high-resolution proxy data. Copyright © 2005 Royal Meteorological Society [source] A Study of CDK2 Inhibitors Using a Novel 3D-QSAR Method Exploiting Receptor FlexibilityMOLECULAR INFORMATICS, Issue 8 2009Michael Abstract A new 3D-QSAR method based on the novel molecular dynamics methodology, Active Site Pressurization (ASP), has been validated using two cyclin-dependent kinase 2 data sets containing 65 purines and 91 oxindoles. ASP allows the construction of cavity casts that represent the maximal energetically feasible 3D distortion of protein binding sites potentially achievable by induced fit upon binding of ligands. The ASP-QSAR method entails many components of traditional 3D-QSAR strategies but additionally correlates the biological activity of ligand sets with features of ASP-derived binding site cavity casts, thus taking target protein flexibility into account implicitly. Both of the data sets used to validate the ASP-QSAR method resulted in QSAR models that were of exceptional quality and predictivity. A non-cross-validated variance coefficient (R2) between 0.959 and 0.99 and a cross-validated variance coefficient (Q2) of between 0.927 and 0.929 were obtained for these ASP-QSAR models. [source] An evaluation of PCR primer sets used for detection of Propionibacterium acnes in prostate tissue samplesTHE PROSTATE, Issue 14 2008Karen S. Sfanos Abstract BACKGROUND Multiple studies have now shown that Propionibacterium acnes can be cultured from post-prostatectomy derived prostate tissue samples. In contrast, both universal eubacterial 16S rDNA PCR and P. acnes -specific 16S rDNA PCR have failed to detect this organism at a frequency similar to that of bacterial culture. A potential explanation for this discrepancy, proposed by Cohen et al., involves mismatches in 16S rDNA primer sets used for bacterial detection. METHODS The sensitivity of both a previously published P. acnes -specific primer set containing a potential mismatch and a new primer set with no mismatches was determined. Both primer sets were used to interrogate two sets of DNA samples derived from post-prostatectomy prostate tissues that differed in the level of sterile precautions maintained during tissue collection. RESULTS The number of P. acnes positive samples was associated with the sterility of the sample collection process. In all instances, positive samples were determined to reflect low cell numbers (<10 CFU). CONCLUSIONS Although the results of previous studies have shown that P. acnes is not the only organism potentially present in the prostates of prostate cancer patients, mismatches in PCR primer sets may have also influenced the sensitivity of P. acnes detection. When using PCR in determining the presence of P. acnes in the human prostate, care should be taken to establish the potential influence of exogenous contamination and, due to the sensitivity of the assay, samples exposed to the urethra during the collection process (prostatic secretions, TURP specimens) should not be used. Prostate 68: 1492,1495, 2008. © 2008 Wiley-Liss, Inc. [source] Prediction of Tyrosinase Inhibition Activity Using Atom-Based Bilinear IndicesCHEMMEDCHEM, Issue 4 2007Yovani Marrero-Ponce Prof. Abstract A set of novel atom-based molecular fingerprints is proposed based on a bilinear map similar to that defined in linear algebra. These molecular descriptors (MDs) are proposed as a new means of molecular parametrization easily calculated from 2D molecular information. The nonstochastic and stochastic molecular indices match molecular structure provided by molecular topology by using the kth nonstochastic and stochastic graph-theoretical electronic-density matrices, Mk and Sk, respectively. Thus, the kth nonstochastic and stochastic bilinear indices are calculated using Mk and Sk as matrix operators of bilinear transformations. Chemical information is coded by using different pair combinations of atomic weightings (mass, polarizability, vdW volume, and electronegativity). The results of QSAR studies of tyrosinase inhibitors using the new MDs and linear discriminant analysis (LDA) demonstrate the ability of the bilinear indices in testing biological properties. A database of 246 structurally diverse tyrosinase inhibitors was assembled. An inactive set of 412 drugs with other clinical uses was used; both active and inactive sets were processed by hierarchical and partitional cluster analyses to design training and predicting sets. Twelve LDA-based QSAR models were obtained, the first six using the nonstochastic total and local bilinear indices and the last six with the stochastic MDs. The discriminant models were applied; globally good classifications of 99.58 and 89.96,% were observed for the best nonstochastic and stochastic bilinear indices models in the training set along with high Matthews correlation coefficients (C) of 0.99 and 0.79, respectively, in the learning set. External prediction sets used to validate the models obtained were correctly classified, with accuracies of 100 and 87.78,%, respectively, yielding C values of 1.00 and 0.73. This subset contains 180 active and inactive compounds not considered to fit the models. A simulated virtual screen demonstrated this approach in searching tyrosinase inhibitors from compounds never considered in either training or predicting series. These fitted models permitted the selection of new cycloartane compounds isolated from herbal plants as new tyrosinase inhibitors. A good correspondence between theoretical and experimental inhibitory effects on tyrosinase was observed; compound CA6 (IC50=1.32,,M) showed higher activity than the reference compounds kojic acid (IC50=16.67,,M) and L -mimosine (IC50=3.68,,M). [source] | ||||||||||||||||