20 research outputs found
Steady late quaternary slip rate on the Cinarcik section of the North Anatolian fault near Istanbul, Turkey
The distribution of plate motion between multiple fault strands and how this distribution may evolve remain poorly understood, despite the key implications for seismic hazards. The North Anatolian Fault in northwest Turkey is a prime example of a multistranded continental transform. Here we present the first constraints on late Quaternary slip rates on its northern branch across the Cinarcik Basin in the eastern Marmara Sea. We use both deep penetration and highâresolution multichannel seismic reflection data with a stratigraphic age model to show that a depocenter has persisted near the fault bend responsible for that transform basin. Successively older depocenters have been transported westward by fault motion relative to Eurasia, indicating a uniform rightâlateral slip rate of 18.5âmm/yr over the last 500,000âyears, compared to overall GPS rates (23â24âmm/yr). Thus, the northern branch has slipped at a nearly constant rate and has accounted for most of the relative plate motion between Eurasia and Anatolia since ~0.5âMa
Clustering patients on the basis of their individual course of low back pain over a six month period
<p>Abstract</p> <p>Background</p> <p>Several researchers have searched for subgroups in the heterogeneous population of patients with non-specific low back pain (LBP). To date, subgroups have been identified based on psychological profiles and the variation of pain.</p> <p>Methods</p> <p>This multicentre prospective observational study explored the 6- month clinical course with measurements of bothersomeness that were collected from weekly text messages that were sent by 176 patients with LBP. A hierarchical cluster analysis, Ward's method, was used to cluster patients according to the development of their pain.</p> <p>Results</p> <p>Four clusters with distinctly different clinical courses were described and further validated against clinical baseline variables and outcomes. Cluster 1, a "stable" cluster, where the course was relatively unchanged over time, contained young patients with good self- rated health. Cluster 2, a group of "fast improvers" who were very bothered initially but rapidly improved, consisted of patients who rated their health as relatively poor but experienced the fewest number of days with bothersome pain of all the clusters. Cluster 3 was the "typical patient" group, with medium bothersomeness at baseline and an average improvement over the first 4-5 weeks. Finally, cluster 4 contained the "slow improvers", a group of patients who improved over 12 weeks. This group contained older individuals who had more LBP the previous year and who also experienced most days with bothersome pain of all the clusters.</p> <p>Conclusions</p> <p>It is possible to define clinically meaningful clusters of patients based on their individual course of LBP over time. Future research should aim to reproduce these clusters in different populations, add further clinical variables to distinguish the clusters and test different treatment strategies for them.</p
Evidence-based classification of low back pain in the general population: one-year data collected with SMS Track
Potential predictors for health-related quality of life in stroke patients undergoing inpatient rehabilitation
Comparison of Band Ratioing and Spectral Indices Methods for Detecting Alunite and Kaolinite Minerals using Aster Data
Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) covers a wide spectral region with 14 bands from visible to the thermal infrared. The different band ranges can be capable of discriminating and mapping surface rocks and predicting pathfinder minerals (i.e. alunite, kaolinite etc.) on alteration assemblages of potential targets. The aim of this study is to compare two different discrimination techniques as band ratioing (BR) and spectral indices (SI) applied on Biga â Ăanakkale Area, Turkey. The ground truths were held on 19 locations to compare obtained results. The study area covers altered Miocene age acidic volcanic rocks. Alunite and kaolinite are main minerals in hydrothermal alteration zones. During the image processing, in order to reduce atmospheric effect on ASTER bands, digital numbers of each image channels are converted to relative reflectance for BR and SI techniques. In BR method, two ratios (4/5 and 7/6) were applied to discriminate alunite and kaolinite respectively. However, in SI method, 5 SWIR bands (5, 6, 7, 8, and 9) were taken into account to detect for alunite and kaolinite presence for each mineral. 19 hydrothermal sites were tested by both methods and 13 of them were identified as alunite by using SI method. On the other hand, in BR method, kaolinite and alunite were discriminated in 11 sites and 8 sites, respectively. As a result, SI and BR techniques can detect alunite and kaolinite minerals. SI method gives better results for detecting alunite than that of kaolinite. On the contrary, BR method can be more applicable to discriminate kaolinite than alunite