206 research outputs found
Custom Flow in Molecular Dynamics
Driving an inertial many-body system out of equilibrium generates complex
dynamics due to memory effects and the intricate relationships between the
external driving force, internal forces, and transport effects. Understanding
the underlying physics is challenging and often requires carrying out
case-by-case analysis. To systematically study the interplay between all types
of forces that contribute to the dynamics, a method to generate prescribed flow
patterns could be of great help. We develop a custom flow method to numerically
construct the external force field required to obtain the desired time
evolution of an inertial many-body system, as prescribed by its one-body
current and density profiles. We validate the custom flow method in a Newtonian
system of purely repulsive particles by creating a slow motion dynamics of an
out-of-equilibrium process and by prescribing the full time evolution between
two distinct equilibrium states. The method can also be used with thermostat
algorithms to control the temperature
Reduced-variance orientational distribution functions from torque sampling
We introduce a method to sample the orientational distribution function in
computer simulations. The method is based on the exact torque balance equation
for classical many-body systems of interacting anisotropic particles in
equilibrium. Instead of the traditional counting of events, we reconstruct the
orientational distribution function via an orientational integral of the torque
acting on the particles. We test the torque sampling method in two- and
three-dimensions, using both Langevin dynamics and overdamped Brownian
dynamics, and with two interparticle interaction potentials. In all cases the
torque sampling method produces profiles of the orientational distribution
function with better accuracy than those obtained with the traditional counting
method. The accuracy of the torque sampling method is independent of the bin
size, and hence it is possible to resolve the orientational distribution
function with arbitrarily small angular resolutions
Deleted in Malignant Brain Tumors 1 (DMBT1) is present in hyaline membranes and modulates surface tension of surfactant
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Evaluation of Transperineal Magnetic Resonance Imaging/Ultrasound-Fusion Biopsy Compared to Transrectal Systematic Biopsy in the Prediction of Tumour Aggressiveness in Patients with Previously Negative Biopsy
Objectives: We compared the transperineal MRI/ultrasoundfusion biopsy (fusPbx) to transrectal systematic biopsy (sys-Pbx) in patients with previously negative biopsy and investigated the prediction of tumour aggressiveness with regard to radical prostatectomy (RP) specimen. Material and Methods: A total of 710 patients underwent multiparametric magnetic resonance imaging (mpMRI), which was evaluated in accordance with Prostate Imaging Reporting and Data System (PI-RADS). The maximum PI-RADS (maxPI-RADS) was defined as the highest PI-RADS of all lesions detected in mpMRI. In case of proven prostate cancer (PCa) and performed RP, tumour grading of the biopsy specimen was compared to that of the RP. Significant PCa (csPCa) was defined according to Epstein criteria. Results: Overall, scPCa was detected in 40% of patients. The detection rate of scPCa was 33% for fusPbx and 25% for sysPbx alone (p < 0.005). Patients with a maxPI-RADS ≥3 and a prostate specific antigen (PSA)-density ≥0.2 ng/mL2 harboured more csPCa than those with a PSA-density < 0.2 ng/mL2 (41% [33/81] vs. 20% [48/248]; p < 0.001). Compared to the RP specimen (n = 140), the concordance of tumour grading was 48% (γ = 0.57), 36% (γ = 0.31) and 54% (γ = 0.6) in fusPbx, sysPbx and comPbx, respectively. Conclusions: The combination of fusPbx and sysPbx outperforms both biopsy modalities in patients with re-biopsy. Additionally, the PSA-density may represent a predictor for csPCa in patients with maxPI-RADS ≥3
Extended Abstracts of the Second Privacy Enhancing Technologies Convention (PET-CON 2008.1)
PET-CON, the Privacy Enhancing Technologies Convention, is a forum for researchers, students, developers, and other interested people to discuss novel research, current developments and techniques in the area of Privacy Enhancing Technologies. PET-CON was first conceived in June 2007 at the 7th International PET Symposium in Ottawa, Canada. The idea was to set up a bi-annual convention in or nearby Germany to be able to meet more often than only once a year at some major conference
Towards the integration and development of a cross-European research network and infrastructure:the DEterminants of DIet and Physical ACtivity (DEDIPAC) Knowledge Hub
To address major societal challenges and enhance cooperation in research across Europe, the European Commission has initiated and facilitated ‘joint programming’. Joint programming is a process by which Member States engage in defining, developing and implementing a common strategic research agenda, based on a shared vision of how to address major societal challenges that no Member State is capable of resolving independently. Setting up a Joint Programming Initiative (JPI) should also contribute to avoiding unnecessary overlap and repetition of research, and enable and enhance the development and use of standardised research methods, procedures and data management. The Determinants of Diet and Physical Activity (DEDIPAC) Knowledge Hub (KH) is the first act of the European JPI ‘A Healthy Diet for a Healthy Life’. The objective of DEDIPAC is to contribute to improving understanding of the determinants of dietary, physical activity and sedentary behaviours. DEDIPAC KH is a multi-disciplinary consortium of 46 consortia and organisations supported by joint programming grants from 12 countries across Europe. The work is divided into three thematic areas: (I) assessment and harmonisation of methods for future research, surveillance and monitoring, and for evaluation of interventions and policies; (II) determinants of dietary, physical activity and sedentary behaviours across the life course and in vulnerable groups; and (III) evaluation and benchmarking of public health and policy interventions aimed at improving dietary, physical activity and sedentary behaviours. In the first three years, DEDIPAC KH will organise, develop, share and harmonise expertise, methods, measures, data and other infrastructure. This should further European research and improve the broad multi-disciplinary approach needed to study the interactions between multilevel determinants in influencing dietary, physical activity and sedentary behaviours. Insights will be translated into more effective interventions and policies for the promotion of healthier behaviours and more effective monitoring and evaluation of the impacts of such intervention
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