6,452 research outputs found
The Fear Management Model: Building an Integrative Fear Appeal Theory through System Dynamics
[[abstract]]This paper attempts to refine the Extended Parallel Process Model by adding the notion of hope to highlight the significant role of fear in fear appeals. Using System Dynamics modeling methods to reformulate the key constructs and integrate the ideas drawn from theories of multiple disciplines, the relationship between danger control and fear control
processes are modified. Accordingly, the Fear Management Model is devised to fix the flaws and resolve the major unanswered questions in fear appeal literatures. Moreover, the implications for helping resistant audiences to pursue adaptive behaviors are discussed. Fourteen propositions are proposed for guiding hypothesis development in future research.[[notice]]補ćŁĺ®Ś
Seasonal variation of the three-dimensional mean circulation over the Scotian Shelf
The seasonal-mean circulation over the Scotian Shelf is studied numerically by computing mean and tidal current fields for winter, spring, and summer using a three-dimensional nonlinear diagnostic model. The mean current fields are forced by seasonal-mean baroclinic pressure gradients, tidal rectification, uniform wind stresses, and associated barotropic pressure gradients. A historical hydrographic database is used to determine the climatological mean baroclinic forcing. Upstream open boundary conditions are estimated from the density fields to give no normal geostrophic bottom flow and are specified as either along-boundary elevation gradients or depth-integrated normal velocities. The numerical solutions for nominal bimonthly periods (January–February, April–May, and July–August) reveal the dominant southwestward nearshore and shelf-break flows of relatively cool and fresh shelf water from the Gulf of St. Lawrence and Newfoundland Shelf, with speeds up to about 20 cm/s. The seasonal intensification of the southwestward flows is reproduced by the model, with the transport increasing from 0.3 Sv in summer to 0.9 Sv in winter on the inner Halifax section. There are also pronounced topographic-scale influences of submarine banks, basins, and cross-shelf channels on the circulation, such as anticyclonic gyres over banks and cyclonic gyres over basins. Baroclinicity is the dominant forcing throughout the domain, but tidal rectification is comparable on the southwestern Scotian Shelf (e.g., about 0.2 Sv recirculating transport around Browns Bank for all the periods). The mean wind stress generates offshore surface drift in winter. The solutions are in approximate agreement with observed currents and transports over the Scotian Shelf, although there are local discrepancies
Reducing Selection Bias in Analyzing Longitudinal Health Data with High Mortality Rates
Two longitudinal regression models, one parametric and one nonparametric, are developed to reduce selection bias when analyzing longitudinal health data with high mortality rates. The parametric mixed model is a two-step linear regression approach, whereas the nonparametric mixed-effects regression model uses a retransformation method to handle random errors across time
Concentration dependence of diffusion coefficient at various molecular weights and temperatures
The effect of temperature on the concentration dependence of the diffusion coefficient D(c) is investigated experimentally by light scattering using polystyrene with Mw = 179 000 and 900 000 in toluene and cyclohexane at several temperatures. It is found that D(c) decreases with concentration under the theta condition, and increases in good solvents. The continuous transition from theta ([theta]) to good solvent behaviour is explored, and the results are compared with the existing theoretical predictions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24275/1/0000541.pd
The impact of FORMOSAT-5/AIP observations on the ionospheric space weather
This paper assimilates the in-situ O+ fluxes observations obtained from the Advanced Ionospheric Probe (AIP) onboard the upcoming FORMOSAT-5 (FS-5) satellite and evaluates its possible impact on the ionospheric space weather forecast model. The Observing System Simulation Experiment (OSSE), designed for the global O+ fluxes, is shown to improve the electron density specification in the vicinity of satellite orbits. The root-mean-square-error (RMSE) of the ionospheric electron density obtained from assimilating the daytime O+ fluxes could be improved by ~10 and ~5% for the forecast and nowcast, respectively. Although the improvement of nighttime O+ flux assimilation is less significant compared to the daytime assimilation, it still reveals impacts on the model result. This suggests that nighttime observations might not be sufficient to alter the model trajectory in the positive direction as with the daytime result. Alternative data assimilation approaches, such as assimilation of the empirical model built by using the nighttime FS-5/AIP together with other existing satellite observations of O+ flux could obtain better accuracy of the electron density forecast
Mercury Contamination in Forest and Freshwater Ecosystems in the Northeastern United States
Eastern North America receives elevated atmospheric mercury deposition from a combination of local, regional, and global sources. Anthropogenic emissions originate largely from electric utilities, incinerators, and industrial processes. The mercury species in these emissions have variable atmospheric residence times, which influence their atmospheric transport and deposition patterns. Forested regions with a prevalence of wetlands and of unproductive surface waters promote high concentrations of mercury in freshwater biota and thus are particularly sensitive to mercury deposition. Through fish consumption, humans and wildlife are exposed to methylmercury, which markedly bioaccumulates up the freshwater food chain. Average mercury concentrations in yellow perch fillets exceed the Environmental Protection Agency’s human health criterion across the region, and mercury concentrations are high enough in piscivorous wildlife to cause adverse behavioral, physiological, and reproductive effects. Initiatives are under way to decrease mercury emissions from electric utilities in the United States by roughly 70%
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Relationship between diffusion capacity and small airway abnormality in COPDGene.
Impaired single breath carbon monoxide diffusing capacity (DLCO) is associated with emphysema. Small airways disease (SAD) may be a precursor lesion to emphysema, but the relationship between SAD and DLCO is undescribed. We hypothesized that in mild COPD, functional SAD (fSAD) defined by computed tomography (CT) and Parametric Response Mapping methodology would correlate with impaired DLCO. Using data from ever-smokers in the COPDGene cohort, we established that fSAD correlated significantly with lower DLCO among both non-obstructed and GOLD 1-2 subjects. The relationship between DLCO with CT-defined emphysema was present in all GOLD stages, but most prominent in severe disease. TRIAL REGISTRATION: NCT00608764. Registry: COPDGene. Registered 06 February 2008, retrospectively registered
Interpretation of dynamic scattering from polymer solutions
The theoretical results available for the interpretation of the dynamic scattering from polymer solutions have been re-examined. The scattering law S(q, t) is formulated using the eigenfunction expansion method and the linear response theory. All previously known exact expressions of S(q, t) for a single unperturbed Gaussian chain have been re-derived using the first method to demonstrate the interrelationships among the various approaches to calculation of S(q, t). The results are cast into new forms which, in many cases, are more convenient for both numerical and analytical discussions. The infinite chain results are obtained from the exact closed expression of S(q, t) for ring polymers as a special case as N --> [infinity]. Questions like the effect of the draining parameter on the shape of S(q, t), the positive definiteness of the diffusion tensor, and the possibility of measuring the eigenvalue of the first internal mode through light scattering, have been included in the discussions.A new method has been proposed for the interpretation of the dynamic scattering experiments in terms of the initial slope, [Omega], of In S(q, t). The quantity [Omega] can also be identified as the first cumulant of S(q, t). The advantage of this method is that [Omega](q) can be calculated for all q values as a function of temperature and concentration by combining the linear response theory and the blob model of chain statistics. Consequently, one is not restricted to the asymptotic small- and intermediate-q regions in order to interpret the scattering experiments. The analytical and numerical results giving [Omega](q) under various conditions have been presented. Using infinite chain results it is shown that [Omega] acts as a characteristic frequency in the sense that in both the small- and intermediate-q regions, In S(q, t) can be scaled to a q-independent shape function when time is expressed as [Omega]t. This property facilitates the measurement of [Omega] from S(q, t)-data using a known shape function. The feasibility of the method has been demonstrated using light scattering data on polystyrene in toluene in the transition region between small- and intermediate q-regions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23191/1/0000118.pd
Comparative evaluation of [(99m)tc]tilmanocept for sentinel lymph node mapping in breast cancer patients: results of two phase 3 trials.
BackgroundSentinel lymph node (SLN) surgery is used worldwide for staging breast cancer patients and helps limit axillary lymph node dissection. [(99m)Tc]Tilmanocept is a novel receptor-targeted radiopharmaceutical evaluated in 2 open-label, nonrandomized, within-patient, phase 3 trials designed to assess the lymphatic mapping performance.MethodsA total of 13 centers contributed 148 patients with breast cancer. Each patient received [(99m)Tc]tilmanocept and vital blue dye (VBD). Lymph nodes identified intraoperatively as radioactive and/or blue stained were excised and histologically examined. The primary endpoint, concordance (lower boundary set point at 90 %), was the proportion of nodes detected by VBD and [(99m)Tc]tilmanocept.ResultsA total of 13 centers contributed 148 patients who were injected with both agents. Intraoperatively, 207 of 209 nodes detected by VBD were also detected by [(99m)Tc]tilmanocept for a concordance rate of 99.04 % (p < 0.0001). [(99m)Tc]tilmanocept detected a total of 320 nodes, of which 207 (64.7 %) were detected by VBD. [(99m)Tc]Tilmanocept detected at least 1 SLN in more patients (146) than did VBD (131, p < 0.0001). In 129 of 131 patients with ≥1 blue node, all blue nodes were radioactive. Of 33 pathology-positive nodes (18.2 % patient pathology rate), [(99m)Tc]tilmanocept detected 31 of 33, whereas VBD detected only 25 of 33 (p = 0.0312). No pathology-positive SLNs were detected exclusively by VBD. No serious adverse events were attributed to [(99m)Tc]tilmanocept.Conclusion[(99m)Tc]Tilmanocept demonstrated success in detecting a SLN while meeting the primary endpoint. Interestingly, [(99m)Tc]tilmanocept was additionally noted to identify more SLNs in more patients. This localization represented a higher number of metastatic breast cancer lymph nodes than that of VBD
The HST Key Project on the Extragalactic Distance Scale XXVI. The Calibration of Population II Secondary Distance Indicators and the Value of the Hubble Constant
A Cepheid-based calibration is derived for four distance indicators that
utilize stars in the old stellar populations: the tip of the red giant branch
(TRGB), the planetary nebula luminosity function (PNLF), the globular cluster
luminosity function (GCLF) and the surface brightness fluctuation method (SBF).
The calibration is largely based on the Cepheid distances to 18 spiral galaxies
within cz =1500 km/s obtained as part of the HST Key Project on the
Extragalactic Distance Scale, but relies also on Cepheid distances from
separate HST and ground-based efforts. The newly derived calibration of the SBF
method is applied to obtain distances to four Abell clusters in the velocity
range between 3800 and 5000 km/s, observed by Lauer et al. (1998) using the
HST/WFPC2. Combined with cluster velocities corrected for a cosmological flow
model, these distances imply a value of the Hubble constant of H0 = 69 +/- 4
(random) +/- 6 (systematic) km/s/Mpc. This result assumes that the Cepheid PL
relation is independent of the metallicity of the variable stars; adopting a
metallicity correction as in Kennicutt et al. (1998), would produce a (5 +/-
3)% decrease in H0. Finally, the newly derived calibration allows us to
investigate systematics in the Cepheid, PNLF, SBF, GCLF and TRGB distance
scales.Comment: Accepted for publication in the Astrophysical Journal. 48 pages
(including 13 figures and 4 tables), plus two additional tables in landscape
format. Also available at http://astro.caltech.edu/~lff/pub.htm K' SBF
magnitudes have been update
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