Investigation of code-switching cost in conversation and self-paced reading tasks

Aims and objectives: Studies of code-switching (CS) in bilingual speakers using laboratory tasks have been equivocal on whether CS is cognitively demanding. The goal of this study was to examine time costs at the juncture of a CS in a more ecologically valid experimental paradigm. Methodology: English (L1)–French (L2) bilingual speakers performed two tasks. The primary experimental task was a novel paradigm that elicited voluntary code-switches in conversation with a bilingual interlocutor. A silent self-paced reading task was used to compare with a laboratory task with involuntary switches. Data and analysis: Intersyllabic durations (conversation task) and reading times (reading task) were analyzed. CS cost was the time difference between code-switches and matched non-switches. Cost-switching costs for each switch direction (English-to-French and French-to-English) and type of switch (alternations and insertions) were also compared. Findings: Code-switches in conversation were associated with a time cost, and the magnitude was comparable in both directions although speakers more frequently switched from French-to-English. In self-paced reading, switching costs were observed only for switches into the dominant language. Across both tasks, there were no differences in CS time cost between insertions and alternations. Originality: This study reports a novel measure of CS costs in conversation, intersyllabic duration, and provides a cross-task comparison in the same group of bilingual speakers to better inform theories of CS. Implications: Bilingual speakers experience a time cost when making voluntary switches in conversations. The symmetrical switch costs suggest that both languages have similar activation levels throughout the conversation, and the cognitive costs arise from the act of momentarily switching languages, irrespective of their dominance. In self-paced reading, cognitive costs arise from disturbing the status quo of relative activation-inhibition of each language adopted to perform the task. The comparable CS time cost for insertions and alternations suggests similar cognitive control and linguistic planning mechanisms for both types of switches.

The Effects of Whole-Body Vibration Exercise on Anticipatory Delay of Core Muscles in Patients with Nonspecific Low Back Pain

Objective. The objective of this study is to determine the effect of whole-body vibration (WBV) exercise on the anticipatory delay of core muscles in nonspecific low back pain (NSLBP) patients. Methods. Forty participants with NSLBP were randomly divided into the WBV group and the control group. The sEMG signals of deltoid, erector spines (ES), multifidus (MF), rectus abdominis (RA), and transversus abdominus/internal oblique muscles (TrA/IO) were recorded before and after the intervention in the weight-shifting task. The relative activation time of each muscle was calculated. Results. In the WBV group, the relative activation time of bilateral MF and bilateral TrA/IO was significantly reduced on shoulder flexion (right MF: P = 0.014 ; left MF: P = 0.011 ; right TrA/IO: P = 0.008 ; left TrA/IO: P = 0.026 ). As for shoulder abduction, except for the left TrA/IO and the left RA, the relative activation time of other muscles was significantly reduced (right ES: P = 0.001 ; left ES: P < 0.001 ; right MF: P = 0.001 ; left MF: P = 0.009 ; right TrA/IO: P < 0.001 ; right RA: P = 0.001 ). In the control group, there was no significant difference in the relative activation time of each muscle before and after the intervention ( P > 0.05 ). Conclusions. WBV exercise can effectively alleviate the anticipatory delay of core muscles in NSLBP patients, but the long-term effects still need further study. This trial is registered with ChiCTR-TRC-13003708.

Mathematical analysis of solar conduction dryer using reaction engineering approach

Solar conduction dryer (SCD) utilizes all three modes of heat transfer, viz., conduction, convection, and radiation. The effect of individual mode of heat transfer in SCD on agricultural product drying was studied using drying kinetics and basic heat transfer calculations. It was observed that the order of influence of mode of heat transfer mechanism as conduction followed by radiation and then convection. The correlation for relative activation energy (∆Ev/∆Ev,∞) as a function of moisture content (X−X∞), effective diffusivity (Deff), and mass transfer coefficient (hm) were determined for each mode of heat transfer. It was observed that the reaction engineering approach (REA) is appropriate tool to understand the physics of drying mechanism in SCD.

Cooperative CO2 absorption by amino acid-based ionic liquids with balanced dual sites

Cooperative CO2 absorption by anion functionalized ILs with dual sites including amino acid group (AA) and basic anion (R) could be achieved through regulating the relative activation of two sites.

Cu-Catalyzed Hydroboration of Benzylidenecyclopropanes: Reaction Optimization, (Hetero)Aryl Scope, and Origins of Pathway Selectivity

The copper-catalyzed hydroboration of benzylidenecyclopropanes, conveniently accessed in one step from readily available benzaldehydes, is reported. Under otherwise identical reaction conditions, two distinct phosphine ligands grant access to different products by either suppressing or promoting cyclopropane opening via β-carbon elimination. Computational studies provide insight into how the rigidity and steric environment of these different bis-phosphine ligands influence the relative activation energies of β-carbon elimination versus protodecupration from the key benzylcopper intermediate. The method tolerates a wide variety of heterocycles prevalent in clinical and pre-clinical drug development, giving access to valuable synthetic intermediates. The versatility of the tertiary cyclopropylboronic ester products is demonstrated through several derivatization reactions.

Cu-Catalyzed Hydroboration of Benzylidenecyclopropanes: Reaction Optimization, (Hetero)Aryl Scope, and Origins of Pathway Selectivity

The copper-catalyzed hydroboration of benzylidenecyclopropanes, conveniently accessed in one step from readily available benzaldehydes, is reported. Under otherwise identical reaction conditions, two distinct phosphine ligands grant access to different products by either suppressing or promoting cyclopropane opening via β-carbon elimination. Computational studies provide insight into how the rigidity and steric environment of these different bis-phosphine ligands influence the relative activation energies of β-carbon elimination versus protodecupration from the key benzylcopper intermediate. The method tolerates a wide variety of heterocycles prevalent in clinical and pre-clinical drug development, giving access to valuable synthetic intermediates. The versatility of the tertiary cyclopropylboronic ester products is demonstrated through several derivatization reactions.

Muscle Activation in the Main Muscle Groups of the Lower Limbs in High-Level Dancesport Athletes

Dancers are subjected to high-intensity workouts when they practice dancesport, and according to the literature, they are prone to injury, primarily of the lower limbs. The purpose of this study was to determine whether differences exist in relative activation amplitudes for dancers involved in dancesport due to muscle, gender, and type of dance. Measurements were carried out using surface electromyography equipment during the choreography of a performance in the following leg muscles: rectus femoris, biceps femoris, tibialis anterior, and gastrocnemius medialis. Eight couples of active dancesport athletes (aged 20.50±2.75 yrs) were analyzed. Significant gender differences were found in rumba in the tibialis anterior (p≤0.05) and gastrocnemius medialis (p≤0.05). Based on the different activations, it is possible to establish possible mechanisms of injury, as well as tools for preventing injuries and improving sports performance.

Measuring REA-based drying kinetics through temperature-moisture content relationship

The reaction engineering approach (REA) has been proposed and implemented for modeling a number of challenging drying cases. While the modeling is simple and accurate, it is effective to generate the drying parameters. The relative activation energy is the fingerprint of the REA which describes the changes of internal behaviors inside the materials during drying. In this paper, a new method, based on combined heat and mass balance, is proposed and implemented to retrieve the relative activation energy of flat materials. The results indicate that the new approach can be used to retrieve well the activation energy of flat materials. The relative activation energy retrieved by the new approach is independent on the external drying conditions. This new approach can also potentially be used to evaluate the change of surface area of materials during drying Keywords: reaction engineering approach (REA);, modeling; relative activation energy; mass transfer;, heat transfer