142 research outputs found

    THE DYNAMIC LOAD ON HAMSTRING MUSCLES DURING SPRINTING

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    The purpose of this study was to analyze the load condition on hamstring muscles during stance and swing phase of sprinting. Three-dimensional videographic and ground reaction force data were collected and the intersegmental dynamics of lower limb was quantified while eight elite male sprint runners performed sprint running with maximum effort. During initial stance phase, the ground reaction torque (EXT) was the main passive torque at knee and hip. During late swing phase, it was motion-dependent torque (MDT) as well. The muscle torques counteracted the large effect of EXT and MDT. This result revealed that the hamstring muscles would suffer from tremendous loads in both initial stance phase and late swing phase. Thus it can be speculated that hamstring muscles were exposed to a higher risk of injury during these two phases in sprinting

    The Maize NBS-LRR Gene ZmNBS25 Enhances Disease Resistance in Rice and Arabidopsis

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    Nucleotide-binding site-leucine-rich repeat (NBS-LRR) domain proteins are immune sensors and play critical roles in plant disease resistance. In this study, we cloned and characterized a novel NBS-LRR gene ZmNBS25 in maize. We found that ZmNBS25 could response to pathogen inoculation and salicylic acid (SA) treatment in maize, and transient overexpression of ZmNBS25 induced a hypersensitive response in tobacco. High-performance liquid chromatography (HPLC) analysis showed that, compared to control plants, ZmNBS25 overexpression (ZmNBS25-OE) in Arabidopsis and rice resulted in higher SA levels. By triggering the expression of certain defense-responsive genes, ZmNBS25-OE enhanced the resistance of Arabidopsis and rice to Pseudomonas syringae pv. tomato DC3000 and sheath blight disease, respectively. Moreover, we found little change of grain size and 1000-grain weight between ZmNBS25-OE rice lines and controls. Together, our results suggest that ZmNBS25 can function as a disease resistance gene across different species, being a valuable candidate for engineering resistance in breeding programs

    How Joint Torques Affect Hamstring Injury Risk in Sprinting Swing-Stance Transition

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    Purpose: The potential mechanisms of hamstring strain injuries in athletes are not well understood. The study, therefore, was aimed at understanding hamstring mechanics by studying loading conditions during maximum-effort overground sprinting. Methods: Three-dimensional kinematics and ground reaction force data were collected from eight elite male sprinters sprinting at their maximum effort. Maximal isometric torques of the hip and knee were also collected. Data from the sprinting gait cycle were analyzed via an intersegmental dynamics approach, and the different joint torque components were calculated. Results: During the initial stance phase, the ground reaction force passed anteriorly to the knee and hip, producing an extension torque at the knee and a flexion torque at the hip joint. Thus, the active muscle torque functioned to produce flexion torque at the knee and extension torque at the hip. The maximal muscle torque at the knee joint was 1.4 times the maximal isometric knee flexion torque. During the late swing phase, the muscle torque counterbalanced the motion-dependent torque and acted to flex the knee joint and extend the hip joint. The loading conditions on the hamstring muscles were similar to those of the initial stance phase. Conclusions: During both the initial stance and late swing phases, the large passive torques at both the knee and hip joints acted to lengthen the hamstring muscles. The active muscle torques generated mainly by the hamstrings functioned to counteract those passive effects. As a result, during sprinting or high-speed locomotion, the hamstring muscles may be more susceptible to high risk of strain injury during these two phases

    Multi-temporal digital twin method and application of landslide deformation monitoring: A case study on Baige landslide in Jinsha River

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    High-locality and hidden landslides, due to its significant characteristics of being difficult to access, identify, and monitor, have strong suddenness and destructiveness when they occur. Continuous monitoring and risk assessment of these landslides are of great significance. Traditional artificial ground survey methods and ground monitoring equipment have the characteristics of high risk, low efficiency, easy damage to equipment, and frequent offline false alarms. Thus, based on unmanned aerial vehicle (UAV) tilt photogrammetry, this study attempts to provide a digital twin method to characterize high-locality and hidden landslides by monitoring and analyzing the deformation and spatiotemporal evolution of geological disasters. This study uses UAV tilt photogrammetry technology to obtain 10 periods of aerial survey data of the Baige landslide on the Jinsha River in Tibet as the research area from April 2019 to September 2021. A multi-temporal digital twin landslide body is constructed, and high-precision quantitative monitoring of multi-dimensional factors, such as the overall sliding characteristics, local micro deformation, and collapse volume of the Baige landslide, is achieved, which are applied to the monitoring and warning of Baige landslide. The results show that there are signs of continuous deformation in the Baige landslide during the monitoring period from 2019 to 2021, and strong deformation mainly occurs at both sides and rear edges of the landslide, gradually expanding, and posing a risk of collapse and river blockage. The multi-temporal digital twin method and application of landslide deformation monitoring on qualitative and quantitative characteristics description and risk assessment of geological disasters are further analyzed. The method in this study has the advantages of fast and flexible, comprehensive coverage, and not limited by complex and dangerous terrain conditions, which could provide information for the large gradient deformation monitoring and engineering practice of slope disasters, such as high-locality and hidden landslides

    Causative agent distribution and antibiotic therapy assessment among adult patients with community acquired pneumonia in Chinese urban population

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    <p>Abstract</p> <p>Background</p> <p>Knowledge of predominant microbial patterns in community-acquired pneumonia (CAP) constitutes the basis for initial decisions about empirical antimicrobial treatment, so a prospective study was performed during 2003–2004 among CAP of adult Chinese urban populations.</p> <p>Methods</p> <p>Qualified patients were enrolled and screened for bacterial, atypical, and viral pathogens by sputum and/or blood culturing, and by antibody seroconversion test. Antibiotic treatment and patient outcome were also assessed.</p> <p>Results</p> <p>Non-viral pathogens were found in 324/610 (53.1%) patients among whom <it>M. pneumoniae </it>was the most prevalent (126/610, 20.7%). Atypical pathogens were identified in 62/195 (31.8%) patients carrying bacterial pathogens. Respiratory viruses were identified in 35 (19%) of 184 randomly selected patients with adenovirus being the most common (16/184, 8.7%). The nonsusceptibility of <it>S. pneumoniae </it>to penicillin and azithromycin was 22.2% (Resistance (R): 3.2%, Intermediate (I): 19.0%) and 79.4% (R: 79.4%, I: 0%), respectively. Of patients (312) from whom causative pathogens were identified and antibiotic treatments were recorded, clinical cure rate with ÎČ-lactam antibiotics alone and with combination of a ÎČ-lactam plus a macrolide or with fluoroquinolones was 63.7% (79/124) and 67%(126/188), respectively. For patients having mixed <it>M. pneumoniae </it>and/or <it>C. pneumoniae </it>infections, a better cure rate was observed with regimens that are active against atypical pathogens (e.g. a ÎČ-lactam plus a macrolide, or a fluoroquinolone) than with ÎČ-lactam alone (75.8% vs. 42.9%, <it>p </it>= 0.045).</p> <p>Conclusion</p> <p>In Chinese adult CAP patients, <it>M. pneumoniae </it>was the most prevalent with mixed infections containing atypical pathogens being frequently observed. With <it>S. pneumoniae</it>, the prevalence of macrolide resistance was high and penicillin resistance low compared with data reported in other regions.</p

    TRY plant trait database – enhanced coverage and open access

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    Plant traits - the morphological, anatomical, physiological, biochemical and phenological characteristics of plants - determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait‐based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits - almost complete coverage for ‘plant growth form’. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait–environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

    Risk factors of deep vein thrombosis in children with osteomyelitis

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    AbstractObjective To investigate the risk factors for deep vein thrombosis (DVT) in children with osteomyelitis and provide diagnostic and treatment strategies for the prevention, early detection and treatment of DVT.Study design The clinical data of nine children diagnosed with osteomyelitis and DVT between July 2012 and March 2021 were collected at our hospital, including age, sex, clinical manifestations, body temperature, coagulation function and other data, as well as the clinical data of 27 children diagnosed with osteomyelitis without DVT during the same period. Thirty-six children were divided into thrombus and thrombus-free groups. The clinical characteristics and risk factors for DVT in children with osteomyelitis were analysed.Results Among the 36 children in this study, nine cases of thrombus formation mainly occurred in the femoral vein, popliteal vein and iliac vein, all near the infection site. The main clinical manifestations were lower extremity pain, swelling and pulmonary embolism in three cases. Among them, intensive care unit (ICU) admission, sepsis, higher D-dimer, higher body temperature during hospitalization, and pathogen culture showed that methicillin-resistant Staphylococcus aureus (MRSA) was associated with DVT. MRSA was the independent risk factor for DVT.Conclusions Admission to ICU, sepsis, higher D-dimer, higher body temperature during hospitalization, and MRSA are risk factors for thrombosis. MRSA is the independent risk factor for DVT. For patients with related risk factors, timely ultrasound examination of the infected site should be considered to achieve early detection and treatment

    Subspace model identification methods for identifying the small-scale unmanned helicopter dynamics

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    Because most multivariable control methods are model-based, and the dynamic model for a particular small-scale helicopter which is simple enough to be practical for controller is not readily available, the identification of small-scale helicopter's dynamic model is a necessary part of any model-based control design. This paper describes the MOESP method which uses numerically robust computation tools applied in the model identification of a small-scale helicopter dynamics. The result of simulation shows this method is suitable for the dynamic identification of a small-scale helicopter
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