1,162 research outputs found
Model for the Scaling of Stresses and Fluctuations in Flows near Jamming
We probe flows of soft, viscous spheres near the jamming point, which acts as
a critical point for static soft spheres. Starting from energy considerations,
we find nontrivial scaling of velocity fluctuations with strain rate. Combining
this scaling with insights from jamming, we arrive at an analytical model that
predicts four distinct regimes of flow, each characterized by rational-valued
scaling exponents. Both the number of regimes and values of the exponents
depart from prior results. We validate predictions of the model with
simulations.Comment: 4 pages, 5 figures (revised text and one new figure). To appear in
Phys. Rev. Let
The Patient Journey from Randomization to Detection of Prostate Cancer and Death:Results from ERSPC Rotterdam
Membrane Microviscosity Modulates Îś-Opioid Receptor Conformational Transitions and Agonist Efficacy
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66282/1/j.1471-4159.1999.0730289.x.pd
An adaptive wavelet-based collocation method for solving multiscale problems in continuum mechanics
Computational multiscale methods are highly sophisticated numerical approaches to predict the constitutive response of heterogeneous materials from their underlying microstructures. However, the quality of the prediction intrinsically relies on an accurate representation of the microscale morphology and its individual constituents, which makes these formulations computationally demanding. Against this background, the applicability of an adaptive wavelet-based collocation approach is studied in this contribution. It is shown that the Hill–Mandel energy equivalence condition can naturally be accounted for in the wavelet basis, (discrete) wavelet-based scale-bridging relations are derived, and a wavelet-based mapping algorithm for internal variables is proposed. The characteristic properties of the formulation are then discussed by an in-depth analysis of elementary one-dimensional problems in multiscale mechanics. In particular, the microscale fields and their macroscopic analogues are studied for microstructures that feature material interfaces and material interphases. Analytical solutions are provided to assess the accuracy of the simulation results
Prostate Cancer Mortality Among Elderly Men After Discontinuing Organised Screening:Long-term Results from the European Randomized Study of Screening for Prostate Cancer Rotterdam
Background: The optimal timing for discontinuing screening of prostate cancer (PCa) in elderly men is currently not known and remains debated. Objective: To assess prostate cancer–specific mortality (PCSM) in elderly men who previously underwent prostate-specific antigen (PSA)-based screening and to identify those who may benefit from continued screening. Design, setting, and participants: A total of 7052 men, who participated in the screening arm of the Rotterdam section of the European Randomized Study of Screening for Prostate Cancer and were aged 70–74 yr at their last screening visit after undergoing a maximum of three screening rounds without being diagnosed with PCa, were included. Outcome measurements and statistical analysis: The cumulative incidence of PCSM by the age of 85 yr was assessed. Additionally, a competing risk regression was performed to assess the potential predictors of PCSM. Results and limitations: The median follow-up was 16 yr. The cumulative incidence of PCSM by the age of 85 yr was 0.54% (95% confidence interval [CI]: 0.40–0.70) in all men, 0.11% (95% CI: 0.05–0.27) in men with PSA <2 ng/ml, 0.85% (95% CI: 0.47–1.5) in men with PSA 2–3 ng/ml, and 6.8% (95% CI: 3.1–15) in men with PSA ≥6.5 ng/ml and no previous benign biopsy. PSA (subdistribution hazard ratio [sHR]: 2.0; 95% CI: 1.7–2.3), previous benign prostate biopsy (sHR: 0.41; 95% CI: 0.23–0.72), and hypertension (sHR: 0.48; 95% CI: 0.25–0.91) were significantly associated with PCSM. Conclusions: Men aged 70–74 yr who have previously undergone PSA-based screening without receiving a PCa diagnosis have a very low risk of dying from PCa by the age of 85 yr. These data suggest that screening may be discontinued in men with PSA <3.0 ng/ml or previous benign prostate biopsies. Those with higher PSA levels and no prior biopsies may consider continued screening if life expectancy exceeds 10 yr. Patient summary: This study shows that men who participated in a prostate cancer screening trial have a very low risk of dying from prostate cancer if they have not been diagnosed with prostate cancer by the age of 74 yr.</p
Capital structure and its determinants in the United Kingdom – a decompositional analysis
Prior research on capital structure by Rajan and Zingales (1995) suggests that the level of gearing in UK companies is positively related to size and tangibility, and negatively correlated with profitability and the level of growth opportunities. However, as argued by Harris and Raviv (1991), 'The interpretation of results must be tempered by an awareness of the difficulties involved in measuring both leverage and the explanatory variables of interest'. In this study the focus is on the difficulties of measuring gearing, and the sensitivity of Rajan and Zingales' results to variations in gearing measures are tested. Based on an analysis of the capital structure of 822 UK companies, Rajan and Zingales' results are found to be highly definitional-dependent. The determinants of gearing appear to vary significantly, depending upon which component of debt is being analysed. In particular, significant differences are found in the determinants of long- and short-term forms of debt. Given that trade credit and equivalent, on average, accounts for more than 62% of total debt, the results are particularly sensitive to whether such debt is included in the gearing measure. It is argued, therefore, that analysis of capital structure is incomplete without a detailed examination of all forms of corporate debt
Geospatial dimensions of the renewable energy transition — The importance of prioritisation
The renewable energy transition is a priority for many researchers, policy makers, and political leaders because it is projected to stop the dependence of economic growth on increasing fossil fuel use and thus curtail climate change. This study examines how expert judgments affect development decisions to enable the renewable energy transition. Geospatial Multi-Criteria Decision Analyses (MCDA) are frequently used to select offshore wind energy (OWE) sites, however, they are often weak and/or often rely on limited judgement. The Analytical Hierarchy Process is used here with 25 diverse experts to assess the variability in priorities for OWE siting criteria. A geospatial MCDA is implemented using experts' individual priorities, aggregated weights and Monte Carlo simulations. Case study results reveal large variations in expert opinions and bias strongly affecting MCDAs weighted by single decision-makers. A group-decision approach is proposed to strengthen consent for OWE, underpinning the renewable energy transition
Cloud detection and classification based on MAX-DOAS observations
Multi-axis differential optical absorption spectroscopy (MAX-DOAS)
observations of aerosols and trace gases can be strongly influenced by
clouds. Thus, it is important to identify clouds and characterise their
properties. In this study we investigate the effects of clouds on several
quantities which can be derived from MAX-DOAS observations, like radiance, the colour index (radiance ratio at two selected wavelengths), the
absorption of the oxygen dimer O<sub>4</sub> and the fraction of inelastically
scattered light (Ring effect). To identify clouds, these quantities can be
either compared to their corresponding clear-sky reference values, or their
dependencies on time or viewing direction can be analysed. From the
investigation of the temporal variability the influence of clouds can be
identified even for individual measurements. Based on our investigations we
developed a cloud classification scheme, which can be applied in a flexible
way to MAX-DOAS or zenith DOAS observations: in its simplest version, zenith
observations of the colour index are used to identify the presence of clouds
(or high aerosol load). In more sophisticated versions, other
quantities and viewing directions are also considered, which allows
subclassifications like, e.g., thin or thick clouds, or fog. We applied our
cloud classification scheme to MAX-DOAS observations during the
Cabauw intercomparison campaign of Nitrogen Dioxide measuring instruments
(CINDI)
campaign in the Netherlands in summer 2009 and found very good agreement
with sky images taken from the ground and backscatter profiles from a lidar
A literature review to understand health literacy in men with prostate cancer on active surveillance
Background and Objective: Active surveillance (AS) has been established as an important treatment option for patients with localised prostate cancer (PCa). Current evidence suggests that health literacy is an important facilitator or barrier to choosing and adhering to AS. We aim to understand how the level of health literacy has an impact on choosing and adhering to AS for PCa patients. Methods: We performed a narrative literature review in accordance with the Narrative Review guidelines through the MEDLINE online database via PubMed using two different search strategies to identify the relevant literature. We looked at literature until August 2022. A narrative synthesis was performed to identify if there is any evidence on how studies report health literacy as an outcome in the AS population and if there are any interventions targeting health literacy. Key Content and Findings: We identified 18 studies which looked at health literacy in the PCa context. Health literacy was measured in the context of comprehension of information of patients across PCa stages, decision making across PCa stages and quality of life (QoL) across PCa stages. Lower health literacy had a negative impact on the identified themes. Nine of the identified studies used validated health literacy measures. Interventions targeting health literacy have been used to improve health literacy with a positive impact across the patient journey. Conclusions: Health literacy plays an important role in enabling men to take an active part in their treatment journey. In this review, we presented how health literacy is measured and which interventions targeting health literacy are implemented across PCa. These examples of interventions targeting health literacy should be studied further and translated into the AS setting to improve treatment decision making and adherence to AS.</p
- …