196,494 research outputs found
Flowchart of patient screening, inclusion, follow-up of the EMPOWER cohort and patients included for the present analyses (adapted from Verlaan et al. 2017 [20]).
No full textFlowchart of patient screening, inclusion, follow-up of the EMPOWER cohort and patients included for the present analyses (adapted from Verlaan et al. 2017 [20]).</p
The impact of future sea-level rise on the global tides
No full textTides are a key component in coastal extreme water levels. Possible changes in the tides caused by mean sea-level rise (SLR) are therefore of importance in the analysis of coastal flooding, as well as many other applications. We investigate the effect of future SLR on the tides globally using a fully global forward tidal model: OTISmpi. Statistical comparisons of the modelled and observed tidal solutions demonstrate the skill of the refined model setup with no reliance on data assimilation. We simulate the response of the four primary tidal constituents to various SLR scenarios. Particular attention is paid to future changes at the largest 136 coastal cities, where changes in water level would have the greatest impact.Spatially uniform SLR scenarios ranging from 0.5 to 10 m with fixed coastlines show that the tidal amplitudes in shelf seas globally respond strongly to SLR with spatially coherent areas of increase and decrease. Changes in the M2 and S2 constituents occur globally in most shelf seas, whereas changes in K1 and O1 are confined to Asian shelves. With higher SLR tidal changes are often not proportional to the SLR imposed and larger portions of mean high water (MHW) changes are above proportional. Changes in MHW exceed ±10% of the SLR at ~10% of coastal cities. SLR scenarios allowing for coastal recession tend increasingly to result in a reduction in tidal range. The fact that the fixed and recession shoreline scenarios result mainly in changes of opposing sign is explained by the effect of the perturbations on the natural period of oscillation of the basin. Our results suggest that coastal management strategies could influence the sign of the tidal amplitude change. The effect of a spatially varying SLR, in this case fingerprints of the initial elastic response to ice mass loss, modestly alters the tidal response with the largest differences at high latitudes
Extreme sea levels on the rise along Europe’s coasts
No full textFuture extreme sea levels (ESLs) and flood risk along European coasts will be strongly impacted by global warming. Yet, comprehensive projections of ESL that include mean sea level (MSL), tides, waves and storm surges do not exist. Here we show changes in all components of ESL until 2100 in view of climate change. We find that by the end of this century the 100-year event ESL along Europe’s coastlines will on average increase by 57 cm for RCP4.5 and 81 cm for RCP8.5. The North Sea region will face the highest increase in ESLs, amounting to nearly 1 m under RCP8.5 by 2100, followed by the Baltic Sea and Atlantic coasts of the UK and Ireland. Relative Sea Level Rise (RSLR) is the main driver of the projected rise in ESL, with increasing dominance towards the end of the century and for the high-concentration pathway. Changes in storm surges and waves enhance the effects of RSLR along the majority of northern European coasts, locally with contributions up to 40%. In southern Europe, episodic extreme events tend to stay stable, except along the Portuguese coast and the Gulf of Cadiz where reductions in surge and wave extremes offset RSLR by 20-30%. By the end of this century, 5 million Europeans currently under threat of a 100-year ESL could be annually at risk from coastal flooding.JRC.E.1 - Disaster Risk Managemen
Supplemental Material - Accurate Placement and Revisions for Cervical Pedicle Screws Placed With or Without Navigation: A Systematic Review and Meta-Analysis
No full textSupplemental Material for Accurate Placement and Revisions for Cervical Pedicle Screws Placed With or Without Navigation: A Systematic Review and Meta-Analysis by B. J. J. Bindels, B. E. G. Dronkers, M. L. J. Smits, and J. J. Verlaan in Global Spine Journal.</p
Two-sample Kalman filter and system error modelling for storm surge forecasting
No full textTwo directions for improving the accuracy of sea level forecast are investigated in this study. The first direction seeks to improve the forecast accuracy of astronomical tide component. Here, a method is applied to analyze and forecast the remaining periodic components of harmonic analysis residual. This method is found to work reasonably well during calm weather, but poorly during stormy period. This finding has led to continue the study with the second direction, which is about data assimilation implemented into the operational two-dimensional storm surge forecast model. The operational storm surge forecast system in the Netherlands uses a steady-state Kalman filter to provide more accurate initial conditions for forecast runs. An important factor, which determines the success of a Kalman filter, is the specification of system error covariance. In the operational system, the system error covariance is modelled explicitly by assuming isotropy and homogeneity. In this study, we investigate the use of the difference between wind products of two similarly skillful atmospheric models as proxy to the unknown error of the storm surge forecast model. To accommodate this investigation, a new method for computing a steady-state Kalman gain, called the two-sample Kalman filter, is developed in this study. It is an iterative procedure for computing the steadystate Kalman gain of a stochastic process by using two samples of the process. A number of experiments have been performed to demonstrate that this algorithm produces correct solutions and is potentially applicable to different models. The two-sample Kalman filter algorithm is implemented by using the wind products from two meteorological centers: the Royal Dutch Meteorological Institute (KNMI) and UK Met Office (UKMO). Here, the investigation is focused on random component of the system error. Therefore, bias or systematic error is eliminated prior to the implementation of the wind products to the two-sample Kalman filter. The system error spatial correlation estimated from these two wind products is found to be anisotropic, in contrast to the one assumed in the operational system. The steady-state Kalman filter based on this error covariance estimate is found to work well in steering the model closer to the observation data. For the stations along the Dutch coast, the data assimilation is found to improve the forecast accuracy up to about 12 hours. Moreover, it is also demonstrated that this data assimilation system outperforms a steady-state Kalman filter based on isotropy assumption. To further improve the data assimilation system, the two-sample Kalman filter is extended to work with more samples. By using more samples, the computation of the error covariance can be done by averaging over shorter time. This relaxes the stationarity assumption and is expected to simulate better the state-dependence model error. In this study, this algorithm is implemented by using wind ensemble of the LAMEPS, which is operational at the Norwegian Meteorological Institute. This setup is found to perform similarly well as the steady-state Kalman filter during large positive surge. However, the steady-state Kalman filter is found to perform better than the ensemble system in forecasting negative surge. The resulting ensemble spread during negative surge is found to be narrower than the standard deviation assumed by the steady-state Kalman filter. A further investigation on the wind ensemble is required.Delft Institute of Applied MathematicsElectrical Engineering, Mathematics and Computer Scienc
Mixing of marine and fluvial particles in the Scheldt estuary
No full textCivil Engineering and Geoscience
Supplemental Material, GSJ741114_suppl_mat - Local and Distant Recurrence in Resected Sacral Chordomas: A Systematic Review and Pooled Cohort Analysis
No full textSupplemental Material, GSJ741114_suppl_mat for Local and Distant Recurrence in Resected Sacral Chordomas: A Systematic Review and Pooled Cohort Analysis by Daniel Kerekes, C. Rory Goodwin, A. Karim Ahmed, Jorrit-Jan Verlaan, Chetan Bettegowda, Nancy Abu-Bonsrah, and Daniel M. Sciubba in Global Spine Journal</p
Shock Safe Nepal Team Two: Implementation of earthquake safe techniques in rural Nepal
No full textIn April and May 2015 two earthquakes devastated Nepal. Thousands died and a manifold of these were left homeless. In order to aid the reconstruction of Nepal, Delft University of Technology initiated a research project called Shock Safe Nepal, in which multiple teams build on each other’s topics in order to help rebuild Nepal in an earthquake safe manner. A first team performed a reconnaissance mission and made a broad problem assessment of the current situation of Nepal. Building upon this work, our team investigated the current situation (February and March 2016) in rural Nepal. What solutions can be integrated in rural Nepal in order to make it earthquake safe? And how can these solutions be made both durable and permanent? In order to leave a lasting impression, not only has the feasibility of the solutions been taken into account, but also the needs and wishes of the local population. To dissipate the solutions into society, a profound understanding of the social and educational network in rural Nepal is highly necessary. Our team has examined the rural area in the development region of Central Nepal with a focus on the Sindhulpalchok, Rasuwa, Kavrepalanchok, Lalitpur, Makwanpur and Dolakha districts. An initial case study has been performed in the village of Ratankot (Sindhupalchok). The technical investigation concentrated on the few buildings that were still standing, the techniques they employed and the damages they sustained. The social investigation included meetings with a number of key people in the village, as well as a survey among the local population and an up-close observation of the rebuilding process. Our findings of this case study have been validated in various other rural villages. The output of our research can be divided in four end-products: A technical damage evaluation, a social and educational representation of Nepal, a future-oriented approach to urban planning in these rural areas, and finally a strategic action-plan on how to integrate shock-safe solutions. The technical damage evaluation expands on the destruction that has directly been done by the earthquake, on what repairs are possible for the buildings and on the essentials a building should include in order to augment the safety of the houses regarding earthquakes. The social and educational representation elaborates on the working and interaction with local communities in rural Nepal. It discusses the best way to approach the local population in order to leave a lasting impression. The urban planning approach describes a long-term view of developing the rural settlements throughout Nepal. The team’s field experience in rural Nepal led to observations on internal strengths and weaknesses which are inherent to rural Nepal. The strategic action plan discusses a short-term, a mid-term, and a long-term strategy, recommended for implementing an earthquake safe environment in rural Nepal. The purpose of this research is to be a logical step in a series of research projects which will contribute to the reconstruction of an earthquake safe environment in Nepal. It can be used as consultation advice, guideline or as a base for in-depth follow up research on one of the included topics.Civil Engineering and GeosciencesStructural Engineering / Construction, Management & EngineeringShock Safe Nepal, Multidisciplinary projectMP19
Dr. Duane M. Jackson, Morehouse College, July 2011
No full textThis video is a conversation with Dr. Duane M. Jackson. Dr. Jackson talks about his paper, "Recall and the Serial Position Effect: The Role of Primacy and Recency on Accounting Students' Performance." Jackie Daniel, AUC Woodruff Library, is the interviewer
"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States" By M. Carey.
No full text"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States: containing bried sketches of the moral and political character of those states.
By M. Carey, member of the American philosophical, and of the American Antiquarian Society, and author of The Olive Branch, Cindiciae Hibernicae, essays on banking, on political economy, and on internal improvement.
To which are now added the English editor's comments on the subject; together with Important Advice to Emigrants, and Cautions Against Impositions Practiced in the Outports
- …
