670 research outputs found
Evolution of the rates of mass wasting and fluvial sediment transfer from the epicentral area of the 1999, Mw 7.6 earthquake
The 1999 Chichi earthquake (Mw=7.6) triggered more than 20,000 landslides in the epicentral area in central west Taiwan, and subsequent typhoons have caused an even larger number of slope failures. As a result, the suspended sediment load of the epi- central Choshui River has increased dramatically. Measurements of suspended sedi- ment at a downstream gauging station indicate that the unit sediment concentration increased about six times due to the earthquake, and decreased exponentially due to flushing by subsequent typhoons. The e-folding time scale of the seismic perturbation of sediment transfer in the Choshui River is 3-5 years. Based on this estimate of the de- cay of the erosional response to the earthquake, a mass balance can be calculated for the earthquake, including co-seismic uplift and subsidence, post-seismic relaxation, and erosion. This mass balance shows that the Chi-Chi earthquake has acted to build ridge topography in the hanging wall of the fault, but in the far field, some destruc- tion of topography has occurred. However, our estimate of seismically-driven erosion may be incomplete. A detailed analysis of landsliding in the Chenyoulan tributary of the Choshui River indicates that most co-and post seismic landslide debris remains on hillslopes within the catchment. Recent typhoons have continued to cause high rates of landsliding high in the landscape, but rates of mass wasting near the stream net- work have decreased. The full geomorphic response to the Chi-Chi earthquake may be much larger, and more protracted than indicated by river gauging data
Cenozoic exhumation history of the Alborz Mountains, Iran: New constraints from low-temperature chronometry
[1] The Alborz Mountains in the north of the Turkish-Iranian Plateau mainly developed in the Cenozoic as a consequence of the closure of Neo-Tethys and continental collision between Arabia and Eurasia. Cenozoic growth of the fold-and-thrust belt exploited an older Palaezoic-Mesozoic crustal fabric but the extent to which this governed the overall form of the mountain belt is unclear. To determine when and how the Alborz mountain belt has grown, apatite fission track (AFT) and (U-Th)/He (AHe) thermochronometry were performed on 46 bedrock samples collected along 8 transects across the range. AFT central ages range from 157 ± 24 Ma to 10 ± 1 Ma with most ages falling between 40 Ma and 10 Ma. AHe ages range from 17 ± 2 Ma to 6 ± 1 Ma. The data revealed enhanced exhumation ca. 35 ± 5 Ma, minor exhumation between ca. 30–20 Ma and an increase in exhumation thereafter. This pattern matches the tripartite Mid-Cenozoic stratigraphy of Central Iran, where Upper Oligocene-Lower Miocene carbonates are sandwiched between terrestrial clastic formations. The most intriguing thermochronometric signal found is a major acceleration of exhumation that initiated in the late Miocene to early Pliocene, recorded by the AHe data. There does not appear to be a direct tectonic cause for Pliocene intensified erosion, as convergence rates between Arabia and Eurasia have remained relatively constant. Enhanced exhumation at this time may reflect a climatically induced intensification of erosion during Caspian isolation and base level fall, or a regional tectonic re-organization of the Arabia-Eurasia collision, or both
Temporal response of mountain drainage basins in Taiwan to earthquake and typhoon perturbation.
In tectonically-active mountain belts, earthquake-triggered landslides deliver large amounts of sediment to rivers. In previous work, we have quantified the geomorphic impact of the 1999 Mw 7.6 Chi-Chi earthquake in Taiwan, which triggered >20,000 landslides and elevated suspended sediment loads in rivers by up to a factor of four. At the time, many coseismic landslides remained confined to hillslopes and, on the basis of four years of hydrometric data, we predicted that downslope transport of sediment would continue to occur during later storms. During the seven years since the Chi- Chi earthquake, several major typhoons storms have hit Taiwan (e.g., Typhoons Bilis, Toraji, Nari, Mindulle, Aere) and the Water Resources Agency of Taiwan has contin- ued to monitor water discharge and suspended sediment concentration. Here we use these new data to refine the spatial and temporal pattern of the decaying geomorphic response to the Chi-Chi earthquake in the face of several large typhoons. Our results indicate that the broad pattern of exponential decay in sediment concentration for a given river discharge (prevalent in winter seasons without typhoons) is punctuated by markedly elevated periods associated with typhoon storms. However, our analyses show that the change in unit sediment concentration (i.e., suspended sediment concen- tration for a unit water discharge) associated with each storm depends more strongly on the length of time elapsed since the earthquake than it does on the magnitude of the storm itself
Preaxial polydactyly of the foot: Clinical and genetic implications for the orthopedic practice based on a literature review and 76 patients
Background and purpose — Preaxial polydactyly of the foot is a rare malformation and clinicians are often unfamiliar with the associated malformations and syndromes. In order to give guidelines for diagnostics and referral to a clinical geneticist, we provide an overview of the presentation using a literature review and our own patient population. Patients and methods — The literature review was based on the Human Phenotype Ontology (HPO) project. From the HPO dataset, all phenotypes describing preaxial polydactyly were obtained and related diseases were identified and selected. An overview was generated in a heatmap, in which the phenotypic contribution of 12 anatomical groups to each disease is displayed. Clinical cases were obtained from our hospital database a
Growth Diagrams for Individual Finger Strength in Children Measured with the RIHM
Background: Although grip and pinch strength provide a more global measure of a large number of digits and muscles, measuring strength of individual fingers or the thumb can provide additional and more detailed information regarding hand strength. Questions/purposes: We developed growth diagrams for individual finger strength in children. Patients and Methods: We measured thumb palmar abduction, thumb opposition, and thumb flexion in the metacarpophalangeal joint, and abduction of the index and little fingers in 101 children (4-12 years old) using a myometer. We recorded hand dominance, gender, height, and weight. All measurements were performed in a randomized order by the same researcher. We developed statistical models for drawing growth diagrams using estimated percentiles for each strength measurement. Separate models for dominant and nondominant hands of boys and girls were developed, in addition to a combined model. Results: Because there was no difference in strength between boys and girls and between dominant and nondominant hands, both hands and genders were combined in one growth diagram for each measurement. The normative data were presented in a table format and in growth diagrams for each myometer measurement. Conclusions: These diagrams can be used for pediatric patients such as patients with congenital malformations or neuromuscular disorders who receive interventions or therapy aimed at function of the hand, fingers, or thumb. The growth diagrams facilitate distinguishing between the effects of growth and intervention on strength development
An observation on the ecology and behaviour of Metallyticus splendidus on a dead dipterocarp tree in Sabah, Malaysia (Mantodea, Metallyticidae)
Metallyticus is a genus of rare mantids, occurring mostly in SouthEast Asia. Five species have been described. However, their ecology and behaviour remain virtually unknown. In this study, we describe a small population of Metallyticus splendidus Westwood, 1889 on a dead dipterocarp tree standing in disturbed tropical rainforest around Danau Girang Field Centre, Sabah, Malaysia. At dawn, in the afternoon and at night, four individuals, two adults and two nymphs, were monitored. Our findings confirm earlier behavioural observations: they hold their bodies flat when running. We did not observe any lurking behaviour: the mantids were walking fast across the tree stem and in tree holes. M. splendidus was found at dawn, in the afternoon, and at night only on this single dead tree in a plot of 50 X 50 m. This suggests that M. splendidus is day and night-active and that its habitat is restricted to dead standing trees. We failed to find other individuals on other dead as well as living trees. Our findings show that the habitat of M. splendidus could be restricted to large dead trees, giving novel insights into the ecology of Metallyticidae.Microbial Biotechnolog
Growth Diagrams for Grip Strength in Children
Abstract: Grip strength dynamometers often are used to assess hand function in children. The use of normative grip strength data at followup is difficult because of the influence of growth and neuromuscular maturation. As an alternative, infant welfare centers throughout the world use growth diagrams to observe normative growth. The aim of this study was to develop similar growth diagrams for grip strength in children. We measured the grip strength, hand dominance, gender, height, and weight of 225 children, 4 to 12 years old. We developed separate statistical models for both hands of boys and girls for drawing growth curves. Grip strength increased with age for both hands. For the whole group, the dominant hand produced higher grip strength than the nondominant hand and boys were stronger than girls. The grip strength of boys and girls differed between 2 and 19 N for the different age groups. Because grip strength measurements are accompanied by a rather large variance, the growth diagrams (presenting a continuum in grip strength) make it possible to better observe grip strength development with time corresponding to a more exact age. Depending on the accuracy needed, the use of one combined diagram could be considered. Level of Evidence: Level II, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence
Serial monitoring of pancreatic stone protein for the detection of sepsis in intensive care unit patients with complicated abdominal surgery: A prospective, longitudinal cohort study.
The objective of this study was to assess the performance of pancreatic stone protein (PSP) monitoring for the detection of sepsis, prediction of outcome and distinction between bacterial and fungal infections in intensive care unit (ICU) patients with complicated abdominal surgery.
In this prospective multicenter cohort study, patients with complicated abdominal surgery had serial PSP measurements during their ICU stay. Infectious episodes were classified as bacterial, fungal or mixed. PSPmax (maximal PSP value within 48 h of the diagnosis of infection) and ΔPSP (difference between PSPmax and the preceding PSP value) were used for analyses.
PSPmax was obtained for 118 infectious episodes (68 patients). ΔPSP was available for 73 episodes (48 patients). Both PSPmax and ΔPSP were significantly higher in patients with sepsis and in patients with a fatal outcome. A PSPmax ≥124 ng/ml and a ΔPSP ≥34 ng/ml could detect sepsis with a sensitivity/specificity of 84%/54% and 69%/76%, respectively. There was no significant difference of PSPmax or ΔPSP between patients with bacterial/mixed versus fungal infections.
Serial PSP monitoring may be an additional tool for the early detection of sepsis in patients with complicated abdominal surgery who are at high risk of severe infections
Stronger relation between impairment and manual capacity in the non-dominant hand than the dominant hand in congenital hand differences; Implications for surgical and therapeutic interventions
Objectives To evaluate manual activity capacity (i.e. activity capacity to perform hand activities) and its relation with body functions of the hand and forearm in children with congenital hand differences (CHD) Methods We assessed 10-14 year-old children with CHD (N = 106) using a functional handgrips test. Measurements of body functions included joint mobility and muscle strength. Patient characteristics were hand dominance and severity. Results We found a stronger relation between body functions and manual activity capacity in non-dominant hands than dominant hands. Dominant hands scored significantly higher on manual activity capacity than nondominant hands that were similarly impaired at body functions level. Severity of the CHD and body functions had only small effects on manual activity capacity. Conclusion The relation between body functions and manual activity capacity is stronger in non-dominant hands than dominant hands, indicating that improvement in body functions lead to larger changes in manual activity capacity in the non-dominant hand. This may suggest that in bilaterally-affected children surgery should be done at the non-dominant hand first since this hand would benefit most from surgery-induced body functions improvement
Dynamics of the Askja caldera July 2014 landslide, Iceland, from seismic signal analysis: precursor, motion and aftermath
Landslide hazard motivates the need for a deeper understanding of the events that occur before, during, and after catastrophic slope failures. Due to the destructive nature of such events, in situ observation is often difficult or impossible. Here, we use data from a network of 58 seismic stations to characterise a large landslide at the Askja caldera, Iceland, on 21 July 2014. High data quality and extensive network coverage allow us to analyse both long- and short-period signals associated with the landslide, and thereby obtain information about its triggering, initiation, timing, and propagation. At long periods, a landslide force history inversion shows that the Askja landslide was a single, large event starting at the SE corner of the caldera lake at 23:24:05 UTC and propagating to the NW in the following 2 min. The bulk sliding mass was 7–16 × 1010 kg, equivalent to a collapsed volume of 35–80 × 106 m3. The sliding mass was displaced downslope by 1260 ± 250 m. At short periods, a seismic tremor was observed for 30 min before the landslide. The tremor is approximately harmonic with a fundamental frequency of 2.3 Hz and shows time-dependent changes of its frequency content. We attribute the seismic tremor to stick-slip motion along the landslide failure plane. Accelerating motion leading up to the catastrophic slope failure culminated in an aseismic quiescent period for 2 min before the landslide. We propose that precursory seismic signals may be useful in landslide early-warning systems. The 8 h after the main landslide failure are characterised by smaller slope failures originating from the destabilised caldera wall decaying in frequency and magnitude. We introduce the term "afterslides" for this subsequent, declining slope activity after a large landslide
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