Caution Needed When Interpreting Muscle Activity Patterns During Extremely Low Pedaling Cadence

Work published in Journal of Sport and Health Science

A KINEMATIC ANALYSIS OF A TOP 10 WTA TENNIS PLAYER’S FIRST SERVE

The purpose of this study was to provide valuable information of the tennis serve, through a three-dimensional (3D) cinematographic analysis of Li Na’s flat serve. Two high-speed cameras operating at 200Hz placed around the baseline recorded her flat service motion. The direct linear transformation (DLT) method was used. The ball was hit at a distance of 1.11 m below a peak ball toss height of 3.65 m. In backswing, the minimum knee flexion angle was about 110°. The lowest point recorded by the racket head was about 0.21 m lower than the height of the body center of gravity during the early drive phase. The velocity of the racket head was 38.2 m/s at impact and the height of the impact point was 2.5 m which was 1.48 times the height of her body. Like other elite tennis players in the world, Li Na has her own tennis strokes and swing style

Estudio sobre la integración de información discursivo-contextual en la enseñanza gramatical del aspecto de español para sinohablantes

This work explores and evaluates the effect of teaching the Spanish past tense aspect (indefinite preterit and imperfective preterit) to Chinese learners in a discourse context compared with the traditional teaching of grammar. We postulate that this teaching methodology—which integrates the content of traditional grammar programs with implicit and explicit instruction on how to interpret discourse-contextual information—will be more effective for Spanish L2 learning in the Chinese university context. In order to test the effect, we conducted a study with two groups of students under two different conditions. The experimental group contained 18 subjects, and the control group, which was taught in a traditional grammar program, contained 17 subjects. Using a teaching experiment that involved three online video-based grammar classes and the gathering of students’ data from pre- and post-tests consisting of comprehension task and multiple-choice tasks, we observed that the instruction of how to interpret aspectual information in a discourse context improved the learners’ ability to analyse and comprehend the target grammar point. However, the learners did not show more accuracy in their use of stative verbs in the post-test than that in the pre-test. FUNDING INFORMATION. This research was funded by National Social Science Foundation of China (20CYY001).Este trabajo explora y evalúa el efecto de la enseñanza del aspecto del tiempo pasado del español a aprendices sinohablantes en el contexto del discurso en comparación con la enseñanza tradicional. Postulamos que esta metodología, que integra los contenidos de los programas de gramática tradicional con instrucciones implícitas y explícitas sobre cómo interpretar la información discursiva, es más efectiva en el contexto universitario chino para el aprendizaje de la L2 español. Para probar su efecto, realizamos un estudio con dos grupos de estudiantes de la misma universidad. El grupo experimental consta de 18 sujetos y el grupo de control, que se enseñó en el programa de gramática tradicional, de 17 sujetos. Mediante un experimento de enseñanza que consistió en tres clases basadas en videos y en la recopilación de datos de los estudiantes de pre-test y post-test, que consistieron en una tarea de comprensión y una de opción múltiple, observamos que la instrucción de cómo interpretar información aspectual en el contexto del discurso puede mejorar la capacidad de nuestros alumnos en el análisis y comprensión de la gramática objetiva. Sin embargo, los alumnos no muestran una mayor precisión en su uso de verbos estativos en el post-test

Estudio sobre la integración de información discursivo-contextual en la enseñanza gramatical del aspecto de español para sinohablantes

This work explores and evaluates the effect of teaching the Spanish past tense aspect (indefinite preterit and imperfective preterit) to Chinese learners in a discourse context compared with the traditional teaching of grammar. We postulate that this teaching methodology—which integrates the content of traditional grammar programs with implicit and explicit instruction on how to interpret discourse-contextual information—will be more effective for Spanish L2 learning in the Chinese university context. In order to test the effect, we conducted a study with two groups of students under two different conditions. The experimental group contained 18 subjects, and the control group, which was taught in a traditional grammar program, contained 17 subjects. Using a teaching experiment that involved three online video-based grammar classes and the gathering of students’ data from pre- and post-tests consisting of comprehension task and multiple-choice tasks, we observed that the instruction of how to interpret aspectual information in a discourse context improved the learners’ ability to analyse and comprehend the target grammar point. However, the learners did not show more accuracy in their use of stative verbs in the post-test than that in the pre-test.Este trabajo explora y evalúa el efecto de la enseñanza del aspecto del tiempo pasado del español a aprendices sinohablantes en el contexto del discurso en comparación con la enseñanza tradicional. Postulamos que esta metodología, que integra los contenidos de los programas de gramática tradicional con instrucciones implícitas y explícitas sobre cómo interpretar la información discursiva, es más efectiva en el contexto universitario chino para el aprendizaje de la L2 español. Para probar su efecto, realizamos un estudio con dos grupos de estudiantes de la misma universidad. El grupo experimental consta de 18 sujetos y el grupo de control, que se enseñó en el programa de gramática tradicional, de 17 sujetos. Mediante un experimento de enseñanza que consistió en tres clases basadas en videos y en la recopilación de datos de los estudiantes de pre-test y post-test, que consistieron en una tarea de comprensión y una de opción múltiple, observamos que la instrucción de cómo interpretar información aspectual en el contexto del discurso puede mejorar la capacidad de nuestros alumnos en el análisis y comprensión de la gramática objetiva. Sin embargo, los alumnos no muestran una mayor precisión en su uso de verbos estativos en el post-test.National Social Science Foundation of China (20CYY001

The use of the past tense aspect in Spanish by study At-Home and Study-Abroad Chinese learners in semi-guided written tasks

This work focuses on the influence of L2 acquisition environments (At-Home and Study-Abroad) on the language proficiency of L1 Mandarin Chinese learners of Spanish. We chose the use of Spanish past tense aspect (pretérito indefinido and pretérito imperfecto) as the entry point to analyze Chinese learners proficiency in three semi-guided writing tasks. Our results reveal that the different teaching objectives in these acquisition environments promote a different development of Chinese learners' language capacities in Spanish: the At-Home learners have a more native-like performance when factors at the discourse level are taken into account, whereas the Study-Abroad learners have a more native-like performance when factors at the lexical level are taken into account.However, the usage pattern of the Spanish past tense aspect by learners in both environments share prototypical associations at the lexical and discourse levels. Keywords:past tense aspect, acquisition environment, L2 Spanish, L1 Mandarin Chines

The role of ATP binding cassette A3 (ABCA3) in health and disease using pluripotent stem cell-derived type II alveolar epithelial cells

The most common causes of childhood interstitial lung disease (chILD) are autosomal recessive mutations in the gene encoding ATP Binding Cassette A3 (ABCA3) protein, a lamellar body (LB) associated lipid transporter exclusively expressed within the alveolar epithelial type II cells (AEC2s) in the lung. Instability of primary AEC2s in culture has prevented studies of ABCA3 mutations, resulting in limited understanding of disease pathogenesis. To overcome this challenge, we developed AEC2-like cells from human pluripotent stem cells (PSCs) in vitro, allowing study of normal ABCA3 function and perturbations that result from ABCA3 mutations. To develop an AEC2 model that would recapitulate ABCA3 biology, we targeted human PSC lines with a knock-in GFP fusion reporter (ABCA3:GFP). Differentiations of PSCs into AEC2s (iAEC2s) resulted in exclusive expression of ABCA3:GFP in iAEC2s and intracellular localization to LAMP3+ vesicles, reminiscent of endogenous ABCA3. Moreover, we find these ABCA3:GFP+ iAEC2s express LBs, process surfactant proteins, and secret surfactant lipids, indicative of preserved ABCA3 function. To study the effects of ABCA3 mutations using our model, we generated two sets of PSC reporter lines: 1) two patient-derived iPSC lines carrying rare homozygous E690K and W308R ABCA3 mutations predicted to affect ABCA3 function or trafficking, respectively, and their two syngeneic gene-corrected lines each targeted with the AEC2-specific knock-in fluorescent reporter SFTPCtdTomato; and 2) three syngeneic ABCA3:GFP knock-in iPSC lines encoding wildtype, E690K, or W308R proteins. Directed differentiation of patient iPSCs into iAEC2s revealed attenuated secretion of surfactant-specific lipids, recapitulating clinical findings of surfactant deficiency. Examination of ABCA3 protein trafficking using the ABCA3:GFP fusion reporter revealed retained E690K and W308R mutant ABCA3 protein processing and trafficking compared to the wildtype protein by confocal microscopy and western blot analyses, however mutant iAEC2s exhibited smaller LBs, indicative of defective ABCA3-dependent lipid transport. Bulk RNA sequencing of mutant and gene-corrected SFTPCtdTomato- or ABCA3:GFP-expressing iAEC2s revealed enrichment of the TNF-NFB pathway in both W308R and E690K mutant iAEC2s, validated by lentiviral reporter assays and secretion of NFB-driven cytokines. Thus, we provide insights into how ABCA3 mutations alter AEC2 physiology and developed a platform to study other genetic AEC2 diseases through our ABCA3:GFP reporter system.2021-05-26T00:00:00

Mineralization of 4-chlorophenol and analysis of bacterial community in microbial fuel cells

Abstract4-Chlorophenol (4-CP) was co-metabolically degraded and mineralized with the presence of glucose in microbial fuel cells (MFCs), achieving a degradation rate of 0.58 ± 0.036mg/L-h (7.2 ± 0.5mg/g VSS-h) with an electricity generation of 5.4 ± 0.4W/m3 at an initial 4-CP concentration of 25mg/L. Compared to the open circuit controls, current generation accelerated the removal of 4-CP. Coulombic efficiency decreased from 30.3 ± 2.9% at an initial 4- CP concentration of 5mg/L to 6.3 ± 0.9% at 40mg/L. 4-CP was degraded via the formation of phenol, which was further mineralized. Dominant bacteria most similar to both the exoelectrogenic and electrotrophic uncultured Desulfovibrio, the exoelectrogenic and recalcitrant degrader of uncultured Desulfobulbus, and the exoelectrogenic uncultured Microbacterium were identified in the biofilms. These results demonstrate that 4-CP mineralization using MFCs may be a promising process for remediation of water contaminated with 4-CP as well as for power generation

THE DYNAMIC LOAD ON HAMSTRING MUSCLES DURING SPRINTING

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