Redistribution of multi-phase particulate organic carbon in a marine shelf and canyon system during an exceptional river flood: Effects of Typhoon Morakot on the Gaoping River-Canyon system

This is the final published version of the article. It was originally published in Marine Geology (Sparkes RB, Lin I-T, Hovius N, Galy A, Liu JT, Xu X, Yang R, Marine Geology 2015, 363, 191–201, doi:10.1016/j.margeo.2015.02.013) http://dx.doi.org/10.1016/j.margeo.2015.02.013Volumetrically, turbidity currents are the prime suppliers of sediment to the deep sea, and conveyors of organic carbon from the terrestrial biosphere and submarine shelf into marine depositional basins. They result from complex processes of erosion, transport and deposition that can be difficult to study in detail. Here we present data from the Gaoping submarine canyon system, off SW Taiwan, which was perturbed in 2009 by the addition of flood deposits following Typhoon Morakot and sampled by gravity coring less than 2 months after the event. We use the different origins of organic carbon, distinguished by their carbon and nitrogen concentrations and δ13C and δ15N isotopic composition, to compare and contrast standard and extreme sedimentological conditions. Using well-constrained end-members, the results were de-convolved into inputs of metamorphic and sedimentary fossil organic carbon eroded within the Gaoping River basin, terrestrial non-fossil carbon and marine organic matter. In the upper Gaoping Canyon, sedimentation is dominated by the highly-localised hyperpycnal input of river washload and submarine sediment slumps, each associated with extensive flooding following Typhoon Morakot, whilst the shelf experienced deposition and reworking of hemi-pelagic marine sediments. A terrestrial signal is also found in the core-top of a fine-grained shelf sample over 20 km from the Gaoping Canyon, in a region normally dominated by marine carbon deposition, showing that Morakot was an unusually large flood event. Conversely, sediment from just above the canyon thalweg contains 0.23 wt.% depth-averaged marine organic carbon (37% of the TOC content) implying that terrestrial OC-dominated turbidites are tightly constrained within the canyon. Hyperpycnal processes can lead to the rapid and efficient transport of both terrestrial and submarine sediments to more permanent burial locations.RS was supported by an Engineering and Physical Sciences Research Council (EP/P502365/1 and EP/P504120/1) studentship. JTL was supported by grant number NSC95-2745-M-110-001 for the Fate of Terrestrial–Nonterrestrial Sediments in High Yield Particle–Export River–Sea Systems Program, which provided the cores in this study. We thank Peter Talling for his insightful and constructive comments on the manuscript and a further, anonymous reviewer for generous endorsement

Early Active Motion versus Immobilization after Tendon Transfer for Foot Drop Deformity: A Randomized Clinical Trial

Background: Immobilization after tendon transfers has been the conventional postoperative management. Several recent studies suggest early mobilization does not increase tendon pullout. Questions/purposes: To confirm those studies we determined whether when compared with immobilization early active mobilization after a tendon transfer for foot-drop correction would (1) have a similar low rate of tendon insertion pullout, (2) reduce rehabilitation time, and (3) result in similar functional outcomes (active ankle dorsiflexion, plantar flexion, ROM, walking ability, Stanmore score, and resolution of functional problems. Methods: We randomized 24 patients with surgically corrected foot-drop deformities to postoperative treatment with early mobilization with active motion at 5 days (n = 13) or 4 weeks of immobilization with active motion at 29 days (n = 11). In both groups, the tibialis posterior tendon was transferred to the extensor hallucis longus and extensors digitorum communis for foot-drop correction. Rehabilitation time was defined as the time from surgery until discharge from rehabilitation with independent walking. The minimum followup was 16 months (mean, 19 months; range, 16-38 months) in both groups. Results: We observed no case of tendon pullout in either group. Rehabilitation time in the mobilized group was reduced by an average of 15 days. The various functional outcomes were similar in the two groups. Conclusion: In patients with Hansen's disease, an early active mobilization protocol for foot-drop correction has no added risk of tendon pullout and provides similar functional outcomes compared with immobilization. Early mobilization had the advantage of earlier restoration of independent walking. Level of Evidence: Level I, therapeutic study. See Guidelines for Authors for a complete description of levels of evidenc

Subducted seafloor relief stops rupture in South American great earthquakes: Implications for rupture behaviour in the 2010 Maule, Chile earthquake

Great subduction earthquakes cause destructive surface deformation and ground shaking over hundreds of kilometres. Their rupture length is limited by the characteristic strength of the subduction plate interface, and by lateral variations in its mechanical properties. It has been proposed that subduction of topographic features such as ridges and seamounts can affect these properties and stop rupture propagation, but the required relief and physical mechanisms of topographic rupture limitation are not well understood. Here, we show that the rupture limits of thirteen historic great earthquakes along the South America-Nazca plate margin are strongly correlated with subducted topography with relief >1000m, including the Juan Fernandez Ridge. The northern limit of rupture in the Mw 8.8 Maule, Chile earthquake of 27 February 2010 is located where this ridge subducts. Analysis of intermediate-magnitude earthquakes shows that in most places, the subduction of high seafloor relief creates weak, aseismic zones at the plate interface, which prevent rupture propagation, but that the Juan Fernandez Ridge is associated with a locally strong plate interface. The maximum rupture length, and thus magnitude, of great subduction earthquakes is therefore determined by the size and lateral spacing of topographic features where they are present on the subducting plate. © 2010 Elsevier B.V

Functional asymmetry of transmembrane segments in nicotinic acetylcholine receptors

Nicotinic acetylcholine receptors are heteropentameric ion channels that open upon activation to a single conducting state. The second transmembrane segments of each subunit were identified as channel-forming elements, but their respective contribution in the gating process remains unclear. Moreover, the detailed impact of variations of the membrane potential, such as occurring during an action potential, on the transmembrane domains, is unknown. Residues at the 12' position, close to the center of each second transmembrane segment, play a key role in channel gating. We examined their functional symmetry by substituting a lysine to that position of each subunit and measuring the electrical activity of single channels. For 12' lysines in the alpha, gamma and delta subunits rapid transitions between an intermediate and large conductance appeared, which are interpreted as single lysine protonation events. From the kinetics of these transitions we calculated the pK (a) values of respective lysines and showed that they vary differently with membrane hyperpolarization. Respective mutations in beta or epsilon subunits gave receptors with openings of either intermediate or large conductance, suggesting extreme pK (a) values in two open state conformations. The results demonstrate that these parts of the highly homologous transmembrane domains, as probed by the 12' lysines, sense unequal microenvironments and are differently affected by physiologically relevant voltage changes. Moreover, observation of various gating events for mutants of alpha subunits suggests that the open channel pore exists in multiple conformations, which in turn supports the notion of functional asymmetry of the channel

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

Clinical evaluation of techniques used in the surgical treatment of progressive hemifacial atrophy

We critically review 13 patients with progressive hemifacial atrophy treated with three basic surgical procedures (free flap transplantation, alloplastic implants, micro-fat injections ‘lipofilling’) and further ancillary techniques. In spite of the satisfactory results achieved with the procedures, with the exception of alloplasts, we feel that lipofilling may be considered an interesting solution for soft tissue augmentation of the face especially for moderate adipose defects, due to its repeatability, no donor site morbidity, no complications at the recipient site such as lesions resulting from dissection, bleeding, necrosis, etc. This technique can be performed in a day-hospital with short surgery time, at low cost and without a highly skilled team. For severe grades of adipose atrophy, because of the low blood supply to these tissues which interferes with take of any type of autograft, we think that free flaps actually represent one of the best solutions for soft tissue augmentation

Comparison of laser Doppler flowmetry and thermometry in the postoperative monitoring of replantations

Reliable postoperative monitoring in microvascular surgery is necessary to improve the success rate of reexplorations following vascular compromise. Surface thermometry is known as an easy and inexpensive objective postoperative monitor and therefore is used by many microsurgeons. Reliability, however, is not satisfactory, and therefore several other instrumental methods have been tested of which laser Doppler flowmetry shows the most promising results. This study compared laser Doppler flowmetry to thermometry in the postoperative monitoring after replantation surgery. In 34 patients, 45 replantations and revascularizations were monitored by laser Doppler flowmetry and thermometry. A reliable alarm value of 10 PU was defined for replantations and revascularizations, with a sensitivity of 93% and a specificity of 94%. Thermometry showed a sensitivity of 84% and a specificity of 86% at 29°C