The effect of text-based math task on dynamic stability control during stair descent

Stair descent imposes a significant challenge for dynamic stability among young adults. The effect of a concurrent text-based math task on dynamic stability control remains unclear during stair descent when considering the influence of gait velocity. Twenty-six participants performed three successful stair descent trials under TEXTING or NO-TEXTING conditions at their preferred speed. Synchronous kinematics and kinetics were collected by an eight-camera Vicon infrared motion capture system and two force platforms. Repeated measures analysis of covariance and Wilcoxon signed rank test were used to analyze the differences between the two different task conditions with gait velocity as a covariate. The outcomes indicated that under TEXTING condition, sagittal margin of stability increased at right-foot-landing; step cadence, double-support percentage, sagittal and frontal joint moment decreased; and sagittal and frontal joint angles were also modified. It is concluded that concurrent TEXTING impaired sagittal and frontal stability control during stair descent despite slowing down the step cadence. Knee and ankle joint adjustment strategies were mainly adopted in response to stability control in the sagittal plane with the interference of TEXTING, whereas the hip joint adjustment strategy was adopted in the frontal plane. In conclusion, texting behaviors on mobile phones should be minimized during stair descent.

A computational study of the role of spatial receptive field structure in processing natural and non-natural scenes.

The center-surround receptive field structure, ubiquitous in the visual system, is hypothesized to be evolutionarily advantageous in image processing tasks. We address the potential functional benefits and shortcomings of spatial localization and center-surround antagonism in the context of an integrate-and-fire neuronal network model with image-based forcing. Utilizing the sparsity of natural scenes, we derive a compressive-sensing framework for input image reconstruction utilizing evoked neuronal firing rates. We investigate how the accuracy of input encoding depends on the receptive field architecture, and demonstrate that spatial localization in visual stimulus sampling facilitates marked improvements in natural scene processing beyond uniformly-random excitatory connectivity. However, for specific classes of images, we show that spatial localization inherent in physiological receptive fields combined with information loss through nonlinear neuronal network dynamics may underlie common optical illusions, giving a novel explanation for their manifestation. In the context of signal processing, we expect this work may suggest new sampling protocols useful for extending conventional compressive sensing theory.

Lung protective ventilation in patients undergoing major surgery: a systematic review incorporating a Bayesian approach.

OBJECTIVE: Protective ventilation (PV) has been validated in patients with acute respiratory distress syndrome. However, the effect of PV in patients undergoing major surgery is controversial. The study aimed to explore the beneficial effect of PV on patients undergoing a major operation by systematic review and meta-analysis. SETTING: Various levels of medical centres. PARTICIPANTS: Patients undergoing general anaesthesia. INTERVENTIONS: PV with low tidal volume. PRIMARY AND SECONDARY OUTCOME MEASURES: Study end points included acute lung injury (ALI), pneumonia, atelectasis, mortality, length of stay (LOS) in intensive care unit (ICU) and hospital. METHODS: Databases including PubMed, Scopus, EBSCO and EMBASE were searched from inception to May 2015. Search strategies consisted of terms related to PV and anaesthesia. We reported OR for binary outcomes including ALI, mortality, pneumonia, atelectasis and other adverse outcomes. Weighted mean difference was reported for continuous outcomes such as LOS in the ICU and hospital, pH value, partial pressure of carbon dioxide, oxygenation and duration of mechanical ventilation (MV). MAIN RESULTS: A total of 22 citations were included in the systematic review and meta-analysis. PV had protective effect against the development of ALI as compared with the control group, with an OR of 0.41 (95% CI 0.19 to 0.87). PV tended to be beneficial with regard to the development of pneumonia (OR 0.46, 95% CI 0.16 to 1.28) and atelectasis (OR 0.68, 95% CI 0.46 to 1.01), but statistical significance was not reached. Other adverse outcomes such as new onset arrhythmia were significantly reduced with the use of PV (OR 0.47, 95% CI 0.48 to 0.93). CONCLUSIONS: The study demonstrates that PV can reduce the risk of ALI in patients undergoing major surgery. However, there is insufficient evidence that such a beneficial effect can be translated to more clinically relevant outcomes such as mortality or duration of MV. TRIAL REGISTRATION NUMBER: The study was registered in PROSPERO (http://www.crd.york.ac.uk/PROSPERO/) under registration number CRD42013006416.

Lung protective ventilation in patients undergoing major surgery: a systematic review protocol.

INTRODUCTION: There is growing interest in the use of low tidal volume ventilation in patients undergoing general anaesthesia. However, its potential benefit has long been debated and conflicting results have been reported. We describe here the protocol of a systematic review and meta-analysis for investigating the beneficial effects of low tidal volume ventilation in patients undergoing general anaesthesia. METHODS AND ANALYSIS: Data sources include PubMed, Scopus, Embase and EBSCO. Patients undergoing general anaesthesia will be included irrespective of type of surgery. The intervention is low tidal volume ventilation or protective ventilation, and the control is conventional ventilation. The quality of included trials will be assessed by using Delphi consensus. Outcomes include new onset lung injury, atelectasis, arrhythmia, levels of inflammatory biomarkers, arterial oxygenation, partial pressure of carbon dioxide and alveolar-arterial oxygen gradient. Conventional approaches for meta-analysis will be used, and heterogeneity will be investigated by using subgroup analysis and meta-regression if appropriate. The Bayesian method will be used for the synthesis of binary outcome data. ETHICS AND DISSEMINATION: The systematic review was approved by the ethics committee of Jinhua hospital of Zhejiang university and will be published in a peer-reviewed journal and will be disseminated electronically and in print. REGISTRATION DETAILS: The study protocol has been registered in PROSPERO (http://www.crd.york.ac.uk/PROSPERO/) under registration number CRD42013006416.