bluuebunny/crossref_metadata_2025 huggingface dataset:
A Novel Z-Ring Associated Protein ZapA-Like Protein (PA5407) From Pseudomonas aeruginosa Promotes FtsZ to Form Double Filaments
Authors: Wang Xiaoyu , Ma Xueqin , Li Zhe , Niu Mingyue , Zhai Meiting , Chen Yaodong
Published: August 2021

Bacterial cell division is initiated by the assembly of the contraction ring (Z-ring), which consists of the self-assembled FtsZ protofilaments and dozens of other associate proteins. ZapA, a regulatory protein found in almost all bacteria, stabilizes FtsZ protofilaments to form bundles and enhances the Z-ring condensation. Here, we reported that another small protein from Pseudomonas aeruginosa, ZapA-Like protein (ZapAL; PA5407), is a new FtsZ associated protein. ZapAL exists in many Pseudomonas species and shares only 20% sequence identity to ZapA. ZapAL interacts with FtsZ and induces FtsZ to form long straight double filaments; in comparison, ZapA promotes long bundles with multiple FtsZ filaments. ZapAL has only a mild effect on GTPase activity of FtsZ, which is reduced by around 26% when 10 μM ZapAL is added in the solution. However, to study their assembly dynamics using light-scattering assay, we found that FtsZ-ZapAL double filament is stable and no depolymerization process is observed, which is different from ZapA. Further research found that ZapA and ZapL are likely to form heterodimers. The bundles formed by the mixture of FtsZ-ZapA-ZapAL will depolymerize after GTP is hydrolyzed. Consistent with ZapAL interaction with FtsZ in vitro, the expression of ZapAL-GFP was observed as a narrow band or spots in the middle of the cells, suggesting that it is a component of bacterial division machinery. Similar to ZapA, ZapAL is also not essential for bacterial cell division. Little changes were observed when zapAL gene was deleted, or overexpressed under normal conditions; however, overexpression of ZapAL caused zapA-deficient cells to grow approximately two times longer, showing a mild bacterial division defect. Although we still do not know the exact physiological roles of ZapAL, our results suggest that ZapAL is a novel Z-ring associate protein, which may work together with ZapA to stabilize the FtsZ protofilament and Z-ring structure.
Exploration of an Efficient Electroporation System for Heterologous Gene Expression in the Genome of Methanotroph
Authors: Hu Lizhen , Guo Shuqi , Yan Xin , Zhang Tianqing , Xiang Jing , Fei Qiang
Published: August 2021

One-carbon (C1) substrates such as methane and methanol have been considered as the next-generation carbon source in industrial biotechnology with the characteristics of low cost, availability, and bioconvertibility. Recently, methanotrophic bacteria naturally capable of converting C1 substrates have drawn attractive attention for their promising applications in C1-based biomanufacturing for the production of chemicals or fuels. Although genetic tools have been explored for metabolically engineered methanotroph construction, there is still a lack of efficient methods for heterologous gene expression in methanotrophs. Here, a rapid and efficient electroporation method with a high transformation efficiency was developed for a robust methanotroph of Methylomicrobium buryatense 5GB1. Based on the homologous recombination and high transformation efficiency, gene deletion and heterologous gene expression can be simultaneously achieved by direct electroporation of PCR-generated linear DNA fragments. In this study, the influence of several key parameters (competent cell preparation, electroporation condition, recovery time, and antibiotic concentration) on the transformation efficiency was investigated for optimum conditions. The maximum electroporation efficiency of 719 ± 22.5 CFU/μg DNA was reached, which presents a 10-fold improvement. By employing this method, an engineered M. buryatense 5GB1 was constructed to biosynthesize isobutyraldehyde by replacing an endogenous fadE gene in the genome with a heterologous kivd gene. This study provides a potential and efficient strategy and method to facilitate the cell factory construction of methanotrophs.
Circular Ribonucleic Acid circFTO Promotes Angiogenesis and Impairs Blood–Retinal Barrier Via Targeting the miR-128-3p/Thioredoxin Interacting Protein Axis in Diabetic Retinopathy
Authors: Guo Jianjin , Xiao Feng , Ren Wei , Zhu Yikun , Du Qiujing , Li Qian , Li Xing
Published: August 2021

Background: Increasing attention has been attracted by the role of circular RNAs (circRNAs) in ocular diseases. Previous study has revealed that circ_0005941 (also known as circFTO, an alpha-ketoglutarate–dependent dioxygenase) was upregulated in the vitreous humor of diabetic retinopathy (DR), while its underlying mechanism in DR remains unknown.

Methods: Retinal vascular endothelial cells (RVECs) treated with high glucose (HG) were used to establish the DR cell model. The in vivo assays were conducted using streptozotocin-induced diabetic mice. The circular structure and stability of circFTO were identified by Sanger sequencing and RNase R treatment. RT-qPCR analysis was used to detect the RNA expression. The levels of the mRNA-encoded protein thioredoxin-interacting protein (TXNIP) or angiogenesis-associated proteins (VEGFA, PDGF, and ANG2) and blood–retinal barrier (BRB)-related proteins (ZO-1, Occludin, and Claudin-5) were measured by Western blot. The viability of RVECs was measured using CCK-8 assays. The angiogenesis of RVECs was assessed using tube formation assays in vitro. Endothelial permeability assays were conducted to examine the function of the BRB. The binding between genes was explored using RNA pulldown and luciferase reporter assays.

Results: CircFTO was upregulated in HG-treated RVECs. CircFTO deficiency reversed the HG-induced increase in the viability and angiogenesis of RVECs and alleviated HG-mediated impairment of the BRB. MiR-128-3p bound with circFTO and was downregulated in HG-treated RVECs. TXNIP was a downstream target gene of miR-128-3p. TXNIP was highly expressed in the DR cell model. Rescue assays revealed that circFTO promoted angiogenesis and impaired the blood–retinal barrier by upregulating TXNIP. In the DR mouse model, circFTO silencing inhibited angiogenesis and promoted BRB recovery in vivo.

Conclusion: CircFTO promotes angiogenesis and impairs the blood–retinal barrier in vitro and in vivo by binding with miR-128-3p to upregulate TXNIP in DR.
Genomic Analysis Reveals Heterogeneity Between Lesions in Synchronous Primary Right-Sided and Left-Sided Colon Cancer
Authors: Hu Hanqing , Zhang Qian , Huang Rui , Gao Zhifeng , Yuan Ziming , Tang Qingchao , Gao Feng , Wang Meng , Zhang Weiyuan , Ma Tianyi , Qiao Tianyu , Jin Yinghu , Wang Guiyu
Published: August 2021

Background: The synchronous primary right-sided and left-sided colon cancer (sRL-CC) is a peculiar subtype of colorectal cancer. However, the genomic landscape of sRL-CC remains elusive.

Methods: Twenty-eight paired tumor samples and their corresponding normal mucosa samples from 14 patients were collected from the Second Affiliated Hospital of Harbin Medical University from 2011 to 2018. The clinical–pathological data were obtained, and whole-exome sequencing was performed based on formalin-fixed and paraffin-embedded samples of these patients, and then, comprehensive bioinformatic analyses were conducted.

Results: Both the lesions of sRL-CC presented dissimilar histological grade and differentiation. Based on sequencing data, few overlapping SNV signatures, onco-driver gene mutations, and SMGs were identified. Moreover, the paired lesions harbored a different distribution of copy number variants (CNVs) and loss of heterozygosity. The clonal architecture analysis demonstrated the polyclonal origin of sRL-CC and inter-cancerous heterogeneity between two lesions.

Conclusion: Our work provides evidence that lesions of sRL-CC share few overlapping mutational signatures and CNVs, and may originate from different clones.
Examination of CA1 Hippocampal DNA Methylation as a Mechanism for Closing of Estrogen’s Critical Window
Authors: Sinha Puja , Rani Asha , Kumar Ashok , Riva Alberto , Brant Jason Orr , Foster Thomas C.
Published: August 2021

There is a critical window for estrogen replacement therapy, beyond which estradiol (E2) fails to enhance cognition and N-methyl-D-aspartate (NMDA) receptor function, and E2-responsive transcription decreases. Much less attention has been given to the mechanism for closing of the critical window, which is thought to involve the decline in estrogen signaling cascades, possibly involving epigenetic mechanisms, including DNA methylation. This study investigated changes in DNA methylation in region CA1 of the hippocampus of ovariectomized female rats over the course of brain aging and in response to E2-treatment, using whole genome bisulfite sequencing. Differential methylation of CpG and non-CpG (CHG and CHH) sites and associated genes were characterized in aged controls (AC), middle-age controls (MC), and young controls (YC) and differential methylation in response to E2-treatment (T) was examined in each age group (AT-AC, MT-MC, and YT-YC). Possible candidate genes for the closing of the critical window were defined as those that were hypomethylated by E2-treatment in younger animals, but were unresponsive in aged animals. Gene ontology categories for possible critical window genes were linked to response to hormones (Adcyap1, Agtr2, Apob, Ahr, Andpro, Calm2, Cyp4a2, Htr1b, Nr3c2, Pitx2, Pth, Pdk4, Slc2a2, Tnc, and Wnt5a), including G-protein receptor signaling (Gpr22 and Rgs4). Other possible critical window genes were linked to glutamate synapses (Nedd4, Grm1, Grm7, and Grin3a). These results suggest that decreased E2 signaling with advanced age, and/or prolonged E2 deprivation, results in methylation of E2-responsive genes, including those involved in rapid E2 signaling, which may limit subsequent transcription.
Tricaine Methanesulfonate (MS222) Has Short-Term Effects on Young Adult Zebrafish (Danio rerio) Working Memory and Cognitive Flexibility, but Not on Aging Fish
Authors: Fontana Barbara D. , Alnassar Nancy , Parker Matthew O.
Published: August 2021

Exposure to anesthetic drugs is common in biomedical sciences being part of routine procedures in different translational species, however its impacts on memory and cognition are still debated, having different impacts depending on drug and age. The zebrafish (Danio rerio) is a translational species widely used in behavioral neuroscience, where tricaine methanesulfonate (MS222) is the most acceptable and used drug when conducting routine procedures. Based on this, we investigated the effects of MS222 (100 mg/l) in young adults and aging zebrafish 1, 2, 3, and 7 days after exposure. Animals’ were submitted to the anesthetic procedure until loss of body posture, slowing of opercular movements and lack of response to tail touch with a plastic pipette were achieved, then further left in the drug for 3 min. After that, animals (6 mpf vs. 24 mpf) were transferred to a recovery tank until fully recovered and transferred back to their housing system until further testing in the free movement pattern (FMP) Y-maze, which assesses zebrafish working memory and cognitive lexibility. Young animals had significant impairment in their working memory and cognitive flexibility 1 and 2 days after the exposure to MS222, being fully recovered by day 3 and with no effects 7 days post drug exposure. Increased repetitions were also observed for animals exposed to MS222 which could indicate increased stress-related response in animals up to 2 days after drug exposure. No drug effect was observed in aging animals besides their natural decreased alternations and working memory. Overall, behavioral experiments after routine procedures using MS222 should be performed with caution and need to be delayed, at least 3 days after exposure where working memory, cognitive flexibility, and repetitive behavior are back to normal.
Identifying Individuals With Mild Cognitive Impairment Using Working Memory-Induced Intra-Subject Variability of Resting-State EEGs
Authors: Trinh Thanh-Tung , Tsai Chia-Fen , Hsiao Yu-Tsung , Lee Chun-Ying , Wu Chien-Te , Liu Yi-Hung
Published: August 2021

Individuals with mild cognitive impairment (MCI) are at high risk of developing into dementia (e. g., Alzheimer's disease, AD). A reliable and effective approach for early detection of MCI has become a critical challenge. Although compared with other costly or risky lab tests, electroencephalogram (EEG) seems to be an ideal alternative measure for early detection of MCI, searching for valid EEG features for classification between healthy controls (HCs) and individuals with MCI remains to be largely unexplored. Here, we design a novel feature extraction framework and propose that the spectral-power-based task-induced intra-subject variability extracted by this framework can be an encouraging candidate EEG feature for the early detection of MCI. In this framework, we extracted the task-induced intra-subject spectral power variability of resting-state EEGs (as measured by a between-run similarity) before and after participants performing cognitively exhausted working memory tasks as the candidate feature. The results from 74 participants (23 individuals with AD, 24 individuals with MCI, 27 HC) showed that the between-run similarity over the frontal and central scalp regions in the HC group is higher than that in the AD or MCI group. Furthermore, using a feature selection scheme and a support vector machine (SVM) classifier, the between-run similarity showed encouraging leave-one-participant-out cross-validation (LOPO-CV) classification performance for the classification between the MCI and HC (80.39%) groups and between the AD vs. HC groups (78%), and its classification performance is superior to other widely-used features such as spectral powers, coherence, and the complexity estimated by Katz's method extracted from single-run resting-state EEGs (a common approach in previous studies). The results based on LOPO-CV, therefore, suggest that the spectral-power-based task-induced intra-subject EEG variability extracted by the proposed feature extraction framework has the potential to serve as a neurophysiological feature for the early detection of MCI in individuals.
COSMO-Onset: A Neurally-Inspired Computational Model of Spoken Word Recognition, Combining Top-Down Prediction and Bottom-Up Detection of Syllabic Onsets
Authors: Nabé Mamady , Schwartz Jean-Luc , Diard Julien
Published: August 2021

Recent neurocognitive models commonly consider speech perception as a hierarchy of processes, each corresponding to specific temporal scales of collective oscillatory processes in the cortex: 30–80 Hz gamma oscillations in charge of phonetic analysis, 4–9 Hz theta oscillations in charge of syllabic segmentation, 1–2 Hz delta oscillations processing prosodic/syntactic units and the 15–20 Hz beta channel possibly involved in top-down predictions. Several recent neuro-computational models thus feature theta oscillations, driven by the speech acoustic envelope, to achieve syllabic parsing before lexical access. However, it is unlikely that such syllabic parsing, performed in a purely bottom-up manner from envelope variations, would be totally efficient in all situations, especially in adverse sensory conditions. We present a new probabilistic model of spoken word recognition, called COSMO-Onset, in which syllabic parsing relies on fusion between top-down, lexical prediction of onset events and bottom-up onset detection from the acoustic envelope. We report preliminary simulations, analyzing how the model performs syllabic parsing and phone, syllable and word recognition. We show that, while purely bottom-up onset detection is sufficient for word recognition in nominal conditions, top-down prediction of syllabic onset events allows overcoming challenging adverse conditions, such as when the acoustic envelope is degraded, leading either to spurious or missing onset events in the sensory signal. This provides a proposal for a possible computational functional role of top-down, predictive processes during speech recognition, consistent with recent models of neuronal oscillatory processes.
Tegaserod Maleate Inhibits Esophageal Squamous Cell Carcinoma Proliferation by Suppressing the Peroxisome Pathway
Authors: Wu Xiangyu , Wang Zitong , Jiang Yanan , Zhou Hao , Li Ang , Wei Yaxing , Bao Zhuo , Wang Donghao , Zhao Jimin , Chen Xinhuan , Guo Yaping , Dong Zigang , Liu Kangdong
Published: August 2021

Esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) are the two major types of esophageal cancer (EC). ESCC accounts for 90% of EC. Recurrence after primary treatment is the main reason for poor survival. Therefore, recurrence prevention is a promising strategy for extending the 5-year survival rate. Here, we found tegaserod maleate could inhibit ESCC proliferation both in vivo and in vitro. Proteomics analysis revealed that tegaserod maleate suppressed the peroxisome signaling pathway, in which the key molecules peroxisome membrane protein 11B (PEX11B) and peroxisome membrane protein 13 (PEX13) were downregulated. The immunofluorescence, catalase activity assay, and reactive oxygen species (ROS) confirmed that downregulation of these proteins was related to impaired peroxisome function. Furthermore, we found that PEX11B and PEX13 were highly expressed in ESCC, and knockout of PEX11B and PEX13 further demonstrated the antitumor effect of tegaserod maleate. Importantly, tegaserod maleate repressed ESCC tumor growth in a patient-derived xenograft (PDX) model in vivo. Our findings conclusively demonstrated that tegaserod maleate inhibits the proliferation of ESCC by suppressing the peroxisome pathway.
Hypericin Enhances Paclitaxel-Induced B16-F10 Cell Apoptosis by Activating a Cytochrome c Release–Dependent Pathway
Authors: Sun Liyun , Li Zixuan , Shang Huoli , Xin Xiujuan
Published: August 2021

The enhanced inhibitory effect of paclitaxel (PTX) combined with hypericin (HY) on B16-F10 cells may be realized through the ROS-related cytochrome c release pathway. The apoptotic characteristics of the B16-F10 cells, such as DNA fragmentation, chromatin condensation, and apoptotic body formation, were all enhanced in the combined treatment group. Further investigation showed that the combination of paclitaxel and HY could increase the level of mitochondrial damage and the concentration of cytochrome c, causing the expression of caspase-3 and the cleavage of PARP.1. Compared with paclitaxel or HY alone, the level of reactive oxygen species (ROS) increased significantly, while glutathione reductase (GR) activity and intracellular glutathione (GSH) levels decreased significantly in the combination group.
Regulation of ABC Drug Efflux Transporters in Human T-Cells Exposed to an HIV Pseudotype
Authors: Whyte-Allman Sana-Kay , Kaul Rupert , Bendayan Reina
Published: August 2021

ATP-binding cassette (ABC) drug efflux transporters could contribute to low intracellular concentrations of antiretroviral drugs in HIV-1 cell reservoirs and sanctuary sites. Furthermore, the functional expression of these transporters could be induced in activated T-cells. Therefore, we investigated the expression of ABC drug efflux transporters in human T-cells exposed to an HIV pseudotype virus (pHIVNL4-3), and further examined the potential involvement of the mammalian target of rapamycin (mTOR) signaling pathway in regulating their expression following exposure to pHIVNL4-3. Additionally, we investigated the contribution of the drug efflux transporters to the inflammatory response following pHIVNL4-3-induced T-cell activation. Human peripheral blood mononuclear cells (PBMCs) were exposed to HIV-1 envelope glycoprotein gp120IIIB, pHIVNL4-3 and/or mTOR inhibitors. The expression of ABC transporters, T-cell activation marker CD69, mTOR and pHIVNL4-3 was assessed in CD4+ T-cells by Flow cytometry. mRNA and protein levels of proinflammatory cytokines (IL6, TNFα and INFγ) were examined in PBMCs by qPCR and ELISA analyses, respectively, following exposure to pHIVNL4-3 with or without inhibitors of mTOR or ABC transporters. The expression of ABC transporters (P-glycoprotein, breast cancer resistance protein and multi-drug resistance associated protein-1) was significantly increased in CD4+ T-cells exposed to pHIVNL4-3. Treatment with mTOR inhibitors attenuated pHIVNL4-3-induced transporter expression, as well as mRNA and protein levels of IL6, TNFα and INFγ. Additionally, inhibition of P-gp or MRP1 activity resulted in lower concentrations of proinflammatory cytokines in supernatants of PBMC exposed to pHIVNL4-3. Herein we present novel data demonstrating that upregulation of ABC drug efflux transporters could involve the mTOR signaling pathway in CD4+ T-cells exposed to an HIV pseudotype. These transporters could limit antiretroviral drug penetration in HIV target T-cells. Furthermore, ABC transporters could potentially contribute to HIV-associated proinflammatory cytokine secretion.
Association Between Arterial Oxygen Saturation and Lung Ultrasound B-Lines After Competitive Deep Breath-Hold Diving
Authors: Patrician Alexander , Pernett Frank , Lodin-Sundström Angelica , Schagatay Erika
Published: August 2021

Breath-hold diving (freediving) is an underwater sport that is associated with elevated hydrostatic pressure, which has a compressive effect on the lungs that can lead to the development of pulmonary edema. Pulmonary edema reduces oxygen uptake and thereby the recovery from the hypoxia developed during freediving, and increases the risk of hypoxic syncope. We aimed to examine the efficacy of SpO2, via pulse-oximetry, as a tool to detect pulmonary edema by comparing it to lung ultrasound B-line measurements after deep diving. SpO2 and B-lines were collected in 40 freedivers participating in an international deep freediving competition. SpO2 was measured within 17 ± 6 min and lung B-lines using ultrasound within 44 ± 15 min after surfacing. A specific symptoms questionnaire was used during SpO2 measurements. We found a negative correlation between B-line score and minimum SpO2 (rs = −0.491; p = 0.002) and mean SpO2 (rs = −0.335; p = 0.046). B-line scores were positively correlated with depth (rs = 0.408; p = 0.013), confirming that extra-vascular lung water is increased with deeper dives. Compared to dives that were asymptomatic, symptomatic dives had a 27% greater B-line score, and both a lower mean and minimum SpO2 (all p < 0.05). Indeed, a minimum SpO2 ≤ 95% after a deep dive has a positive predictive value of 29% and a negative predictive value of 100% regarding symptoms. We concluded that elevated B-line scores are associated with reduced SpO2 after dives, suggesting that SpO2 via pulse oximetry could be a useful screening tool to detect increased extra-vascular lung water. The practical application is not to diagnose pulmonary edema based on SpO2 – as pulse oximetry is inexact – rather, to utilize it as a tool to determine which divers require further evaluation before returning to deep freediving.
A Study on the Influencing Factors of Continued Intention to Use MOOCs: UTAUT Model and CCC Moderating Effect
Authors: Li Yalin , Zhao Min
Published: August 2021

Massive Open Online Courses (MOOCs) is the product of “internet + education,” which offer the open educational resources to global students. This study analyzed the factors influencing the continued intention to use the MOOCs by students. To achieve research objectives, this study integrated the unified theory of acceptance and use of technology (UTAUT) and connected classroom climate (CCC). In this study, 312 valid samples were used to verify the hypothesis proposed with the help of structural equation modeling and PROCESS. The results showed that the factors of UTAUT model (performance expectancy, effort expectancy, social influence, and facilitating conditions) had significant positive effects on continued intention to use MOOCs. More importantly, there was a significant moderating effect of CCC between UTAUT and the continued intention to use MOOCs. Based on this research the findings, implications and limitations are discussed.
Smashing, Shaming, or Polite Fun and Joy? How Workplace Humor Influences Positive Well-Being in South Korean Workplaces
Authors: Kim Hee Sun , Plester Barbara
Published: August 2021

Humor is contextual, ambiguous, and varies within cultures but is widely associated with positive outcomes such as well-being and happiness. While humor is universal and enhances interpersonal relationships which can benefit psychological well-being, we argue that humor can also be diminish psychological well-being in Confucian-based, South Korean workplaces. Our research questions asks:how do hierarchical workplace relationships influence shared humor and positive well-being in Korean workplace contexts?Our contextual, ethnographic research includes in-depth field observations and semi structured interviews in three Korean organizations. Traditional Confucian-based cultures value face-saving, trust, and harmony while emphasizing formality and hierarchy. Korean honorifics maintain harmony, hierarchy, and politeness which creates benefits for group processes and influences the sharing of humor. Humor is enacted in accordance with workers' hierarchical status which has a significant impact upon the types of humor shared and the responses available to subordinate employees. Investigating these dimensions in Korean workplaces we argue that honorifics and hierarchy influence humor interactions in complex ways that have implications for psychological well-being.
Employability Paradox: The Effect of Development Idiosyncratic Deals on Recipient Employees’ Turnover Intention
Authors: Zhang Xiaoyan , Deng Hui , Xia Yuhuan , Lan Yuanyuan
Published: August 2021

Applied social cognitive theory, this study built a moderated mediation model to explain how and when development idiosyncratic deals (i-deals) affect recipients’ turnover intention. Specifically, this study proposed two paths that linked development i-deals with the recipients’ turnover intention. One path was a retention path via perceived internal employability and another path was a turnover path via perceived external employability. This study tested the hypotheses with a sample of 337 employees from three companies in China. The results showed that development i-deals improved recipients’ perception of internal and external employability both. Perceived internal employability predicted low risk of turnover, but perceived external employability predicted high risk of turnover. And perceived internal and external employability played mediating roles in the relationship between development i-deals and turnover intention. Furthermore, the recipients’ perception of opportunity to perform in current organization strengthened the relationship between perceived internal employability and turnover intention, but weakened the relationship between perceived external employability and turnover intention. Theoretical and practical implications of these findings were discussed.
Teacher Engagement in Language Teaching: Investigating Self-Efficacy for Teaching Based on the Project “Sino-Greece Online Chinese Language Classrooms”
Authors: Bao Chunrong , Zhang Lawrence Jun , Dixon Helen R.
Published: August 2021

The support of sustainable learning of foreign languages requires teacher engagement and a high level of self-efficacy, both of which are cornerstones for the persistence of teachers in carrying out teaching activities to help learning. The need for such attributes is even more crucial when online learning platforms as a mode of delivery are becoming increasingly popular. We would argue that keeping students engaged and motivated to attain their academic success online calls for the increased levels of resilience and efforts of teachers. Although self-efficacy of teachers has been widely considered crucial in the professional practices of teachers, there is a paucity of research studies on the self-efficacy of teachers who teach Chinese as a foreign language (CFL) using online platforms. Such a gap becomes prominent after the sudden outbreak of the COVID-19 pandemic, especially in places where there are now numerous calls for online CFL classes. In order to fill in this gap, this study was conducted with a frontline CFL teacher as the participant and aimed to detect thoroughly the trajectories of self-efficacy of a CFL teacher in a completely new teaching context. Embedded in the Project of Sino-Greece Online Chinese Language Classrooms, this study employed narrative inquiry and case study as methodological approaches. Thematic analysis was used to analyze the data that consisted of written narratives (the teacher's teaching journals and reflections, field notes of teaching assistant, and emails of students) and spoken narratives. Three research questions guided this study:What are the teacher's beliefs about (1) the opportunity of teaching CFL online? (2) the management of this online project? (3) her personal capability to foster students' engagement in this project?These three questions focused, respectively, on the three components of the self-efficacy system of a teacher (personal efficacy, efficacy within the organization, and professional efficacy). Findings illustrated that the efficacy beliefs of the teacher in these three aspects were at different levels, which resulted from the interplay of external and internal factors; when external factors appeared to be negative, internal factors seemed to play an essential role.
Under the Hood: Skeletal Muscle Determinants of Endurance Performance
Authors: van der Zwaard Stephan , Brocherie Franck , Jaspers Richard T.
Published: August 2021

In the past decades, researchers have extensively studied (elite) athletes' physiological responses to understand how to maximize their endurance performance. In endurance sports, whole-body measurements such as the maximal oxygen consumption, lactate threshold, and efficiency/economy play a key role in performance. Although these determinants are known to interact, it has also been demonstrated that athletes rarely excel in all three. The leading question is how athletes reach exceptional values in one or all of these determinants to optimize their endurance performance, and how such performance can be explained by (combinations of) underlying physiological determinants. In this review, we advance on Joyner and Coyle's conceptual framework of endurance performance, by integrating a meta-analysis of the interrelationships, and corresponding effect sizes between endurance performance and its key physiological determinants at the macroscopic (whole-body) and the microscopic level (muscle tissue, i.e., muscle fiber oxidative capacity, oxygen supply, muscle fiber size, and fiber type). Moreover, we discuss how these physiological determinants can be improved by training and what potential physiological challenges endurance athletes may face when trying to maximize their performance. This review highlights that integrative assessment of skeletal muscle determinants points toward efficient type-I fibers with a high mitochondrial oxidative capacity and strongly encourages well-adjusted capillarization and myoglobin concentrations to accommodate the required oxygen flux during endurance performance, especially in large muscle fibers. Optimisation of endurance performance requires careful design of training interventions that fine tune modulation of exercise intensity, frequency and duration, and particularly periodisation with respect to the skeletal muscle determinants.
Sonic Artefacts of Teotihuacan, Mexico (Horns, Trumpets and Pipes)
Authors: Both Arnd Adje
Published: August 2021

This paper presents the acoustic study of a sample of sonic artefacts, in particular a selection of wind instruments (horns, trumpets and pipes), from the UNESCO World Heritage Centre of Teotihuacan, Mexico, based on a thorough examination of the accessible and playable archaeological finds and the construction and subsequent test of a series of experimental models. Combined with the archaeological and iconographical information, the study helps to deduce information with regard to the urban settings in which these instruments might have been used. It also reveals some basic acoustic components of the music once performed in Teotihuacan.
Assessment of Stress by Serum Biomarkers in Calves and Their Relationship to Ultimate pH as an Indicator of Meat Quality
Authors: García-Torres Susana , Cabeza de Vaca María , Tejerina David , Romero-Fernández María Pilar , Ortiz Alberto , Franco Daniel , Sentandreu Miguel Angel , Oliván Mamen
Published: August 2021

Seventy-eight calves from Asturiana de los Valles, Retinta, and Rubia Gallega breeds, under extensive and intensive farm systems and animal mixing and non-mixing conditions, and during the transport and lairage in slaughterhouses, were studied. This research aimed to study the effect of breed, farm system and mixing conditions on serum biomarkers (cortisol, lactate, glucose, serum amyloid A, haptoglobin, and C-reactive protein) and their relationship with pHu at slaughter time, and to evaluate the response of the serum biomarkers of calves throughout fattening period. Moreover, this study aims to evaluate the response of the biomarkers in each breed during the fattening period. At slaughter time, cortisol and lactate were affected by BreedxFarm; Retinta showed the opposite pattern to the others and revealed the highest glucose in extensive farm systems. Rubia Gallega in mixing revealed the highest Amyloid A and haptoglobin. Extensive calves in mixing conditions showed the highest glucose. There was a relationship among the variables cortisol, lactate, Amyloid A, and pHu. Slaughter time was a major stressor, and the stress response was mainly affected by breed. At slaughter, several biomarkers should be considered.
Adaptation of Livestock to New Diets Using Feed Components without Competition with Human Edible Protein Sources—A Review of the Possibilities and Recommendations
Authors: te Pas Marinus F. W. , Veldkamp Teun , de Haas Yvette , Bannink André , Ellen Esther D.
Published: August 2021

Livestock feed encompasses both human edible and human inedible components. Human edible feed components may become less available for livestock. Especially for proteins, this calls for action. This review focuses on using alternative protein sources in feed and protein efficiency, the expected problems, and how these problems could be solved. Breeding for higher protein efficiency leading to less use of the protein sources may be one strategy. Replacing (part of) the human edible feed components with human inedible components may be another strategy, which could be combined with breeding for livestock that can efficiently digest novel protein feed sources. The potential use of novel protein sources is discussed. We discuss the present knowledge on novel protein sources, including the consequences for animal performance and production costs, and make recommendations for the use and optimization of novel protein sources (1) to improve our knowledge on the inclusion of human inedible protein into the diet of livestock, (2) because cooperation between animal breeders and nutritionists is needed to share knowledge and combine expertise, and (3) to investigate the effect of animal-specific digestibility of protein sources for selective breeding for each protein source and for precision feeding. Nutrigenetics and nutrigenomics will be important tools.
Phytolith and Calcitic Spherulite Indicators from Modern Reference Animal Dung from Mediterranean Island Ecosystems: Menorca, Balearic Islands
Authors: Portillo Marta , Dudgeon Kate , Anglada Montserrat , Ramis Damià , Llergo Yolanda , Ferrer Antoni
Published: August 2021

This study illustrates the contribution of plant and faecal microfossil records to interdisciplinary approaches on the identification, composition, taphonomy and seasonality of livestock dung materials. The focus is on the taphonomy of opal phytoliths and calcitic dung spherulites embedded within modern faecal pellets collected from pasture grounds and pens from a range of animals, including cattle, sheep and pigs from three different farms and seasons of the year in Menorca (Balearic Islands, Spain) declared a Biosphere Reserve by UNESCO. Modern reference materials provide comparative plant and dung microfossil indicators on factors affecting the formation, composition, preservation and decay of animal faeces, as well as on the diverse environmental and anthropogenic aspects influencing these. The reported results show relevant changes in phytolith and spherulite composition according to animal species and age, livestock management, seasonality, and grazing and foddering regimes. Both microfossil records provide fundamental information on taphonomic issues that are understudied, such as the variation in the digestibility among different species, including under investigated animals such as pigs, as well on the seasonality of plant and faecal microfossils that are excreted with dung as an important material for reconstructing human-environment interactions which is commonly overlooked in archaeology.
Identification of Biomolecules Involved in the Adaptation to the Environment of Cold-Loving Microorganisms and Metabolic Pathways for Their Production
Authors: Garcia-Lopez Eva , Alcazar Paula , Cid Cristina
Published: August 2021

Cold-loving microorganisms of all three domains of life have unique and special abilities that allow them to live in harsh environments. They have acquired structural and molecular mechanisms of adaptation to the cold that include the production of anti-freeze proteins, carbohydrate-based extracellular polymeric substances and lipids which serve as cryo- and osmoprotectants by maintaining the fluidity of their membranes. They also produce a wide diversity of pigmented molecules to obtain energy, carry out photosynthesis, increase their resistance to stress and provide them with ultraviolet light protection. Recently developed analytical techniques have been applied as high-throughoutput technologies for function discovery and for reconstructing functional networks in psychrophiles. Among them, omics deserve special mention, such as genomics, transcriptomics, proteomics, glycomics, lipidomics and metabolomics. These techniques have allowed the identification of microorganisms and the study of their biogeochemical activities. They have also made it possible to infer their metabolic capacities and identify the biomolecules that are parts of their structures or that they secrete into the environment, which can be useful in various fields of biotechnology. This Review summarizes current knowledge on psychrophiles as sources of biomolecules and the metabolic pathways for their production. New strategies and next-generation approaches are needed to increase the chances of discovering new biomolecules.
Using Bioacoustics to Examine Vocal Phenology of Neotropical Migratory Birds on a Wild and Scenic River in Arizona
Authors: Bateman Heather L. , Riddle Sidney B. , Cubley Erin S.
Published: August 2021

Passive acoustic recorders have been used successfully as automated survey tools to detect terrestrial wildlife. However, few studies have monitored Neotropical migratory bird use of riparian forest habitat using this technology. Within dryland ecosystems, the forests along rivers support high bird diversity. Many bird species of conservation concern require these floodplain forest habitats for foraging, migration stop-overs, and breeding. Few studies have explored the use of acoustic records in riverine systems designated for conservation for their natural resource value via the Wild and Scenic Rivers Act in the USA. Using acoustic recorders, we document vocal activity of four riparian-obligate species (Bell’s Vireo, Vireo bellii; Summer Tanager, Piranga rubra; Yellow Warbler, Setophaga petechial; and Yellow-billed Cuckoo, Coccyzus americanus) to determine species occurrence along a Wild and Scenic River. We established three study reaches along the perennial Lower Verde River, in the Sonoran Desert of central Arizona, USA. Nine acoustic recorders were used over the period of 80–120 days during the summer of 2018. We measured vegetation composition and structure in 100 m2 plots paired with acoustic recorders. Visualizing vocal activity showed that three species were calling and singing at each reach; whereas, one species, the cuckoo, had fewer recordings and occurred later in the summer. We demonstrate the utility of acoustic monitoring even when applied to rare birds in complex riparian habitats. This information is important for land management and conservation efforts concerning these species of interest and identifying important habitat features in Southwestern US riparian woodlands.
Map Learning in Aging Individuals: The Role of Cognitive Functioning and Visuospatial Factors
Authors: Muffato Veronica , Miola Laura , Pazzaglia Francesca , Meneghetti Chiara
Published: August 2021

Aging coincides with a decline in map learning ability, but it is unclear to what extent different aspects of the mental representation are susceptible. The present study aimed to investigate knowledge about landmarks, their positions and distances (categorical and distance relations, respectively) in relation to aging as well as cognitive functioning (measured with the Montreal Cognitive Assessment [MoCA]), visuospatial abilities, and self-reported wayfinding inclinations. Thirty young adults and 60 older adults (30 aged 63–74 and 30 aged 75–86) learned a map, freely recalled the landmarks and performed a map drawing task (considering the number of landmarks missing, position accuracy and distance accuracy). Before that, older participants were also assessed regarding their general cognitive functioning (MoCA) and a series of visuospatial measures. The results show age-related differences among adults in recalling landmarks and in both categorical and distance relations, with a worsening of performance of old-olds only in the former. Older adults’ MoCA score related to accuracy in the three measures, and an additional role of spatial anxiety was found for distance accuracy. Above and beyond the age-related decline, the quality of older people’s spatial mental representation is related to higher general cognitive level and lower spatial anxiety.
Nobiletin and Xanthohumol Sensitize Colorectal Cancer Stem Cells to Standard Chemotherapy
Authors: Turdo Alice , Glaviano Antonino , Pepe Giacomo , Calapà Federica , Raimondo Stefania , Fiori Micol Eleonora , Carbone Daniela , Basilicata Manuela Giovanna , Di Sarno Veronica , Ostacolo Carmine , Parrino Barbara , Cascioferro Stella , Pecoraro Camilla , Di Franco Simone , Bellavia Diana , Gaggianesi Miriam , Veschi Veronica , Lo Iacono Melania , Ganduscio Gloria , Pantina Vincenzo Davide , Mangiapane Laura Rosa , Bongiorno Maria Rita , Alessandro Riccardo , Todaro Matilde , De Maria Ruggero , Diana Patrizia , Campiglia Pietro , Stassi Giorgio
Published: August 2021

Colorectal cancer (CRC) mortality is mainly caused by patient refractoriness to common anti-cancer therapies and consequent metastasis formation. Besides, the notorious toxic side effects of chemotherapy are a concurrent obstacle to be tackled. Thus, new treatment approaches are needed to effectively improve patient outcomes. Compelling evidence demonstrated that cancer stem cells (CSCs) are responsible for treatment failure and relapse. New natural treatment approaches showed capabilities to selectively target the CSC subpopulation by rendering them targetable by standard cytotoxic compounds. Herein we show the anti-cancer properties of the polymethoxyflavones and prenylflavonoids extracted from Citrus sinensis and Humulus lupulus, respectively. The natural biofunctional fractions, singularly and in combination, reduced the cell viability of CRC stem cells (CR-CSCs) and synergized with 5-fluorouracil and oxaliplatin (FOX) chemotherapy. These phenomena were accompanied by a reduced S and G2/M phase of the cell cycle and upregulation of cell death-related genes. Notably, both phytoextracts in combination with FOX thwarted stemness features in CR-CSCs as demonstrated by the impaired clonogenic potential and decreased Wnt pathway activation. Extracts lowered the expression of CD44v6 and affected the expansion of metastatic CR-CSCs in patients refractory to chemotherapy. Together, this study highlights the importance of polymethoxyflavones and prenylflavonoids as natural remedies to aid oncological therapies.
Enzymatic Metabolism of Flavonoids by Gut Microbiota and Its Impact on Gastrointestinal Cancer
Authors: AL-Ishaq Raghad Khalid , Liskova Alena , Kubatka Peter , Büsselberg Dietrich
Published: August 2021

Gastrointestinal (GI) cancer is a prevalent global health disease with a massive burden on health care providers. Internal and external factors such as obesity, smoking, diet (red meat), low socioeconomic status and infection with Helicobacter pylori are the critical risk factors of GI cancers. Flavonoids are natural phenolic compounds found abundantly in fruits and vegetables. Upon ingestion, 90% of flavonoids consumed require further enzymatic metabolism by the gut microbiome to enhance their bioavailability and absorption. Several epidemiological studies reported that consumption of flavonoids and their enzymatic conversion by gut microbes is strongly associated with the reduced risk of GI cancer development. This review summarizes the current knowledge on the enzymatic conversion of flavonoids by the human gut microbiome. It also addresses the underlying anti-GI cancer effects on metabolic pathways such as apoptosis and cellular proliferation. Overall, metabolites produced from flavonoid’s enzymatic conversion illustrate anti-GI cancer effects, but the mechanisms of action need further clarification.
Differential Response of Müller Cells and Microglia in a Mouse Retinal Detachment Model and Its Implications in Detached and Non-Detached Regions
Authors: Lee Seung-Hee , Park Yong-Soo , Paik Sun-Sook , Kim In-Beom
Published: August 2021

Retinal detachment (RD) is a sight-threatening condition, leading to photoreceptor cell death; however, only a few studies provide insight into its effects on the entire retinal region. We examined the spatiotemporal changes in glial responses in a mouse RD model. In electroretinography, a- and b-waves were reduced in a time-dependent manner. Hematoxylin and eosin staining revealed a gradual decrease in the outer nuclear layer throughout the retinal region. Terminal deoxynucleotidyltransferase dUTP nick end labeling (TUNEL) assay showed that TUNEL-positive photoreceptors increased 5 days after RD and decreased by 14 days. Glial response was evaluated by immunohistochemistry using antibodies against glial fibrillary acidic protein (GFAP, Müller glial marker) and Iba-1 (microglial marker) and osteopontin (OPN, activated microglial marker). GFAP immunoreactivity increased after 7 days in complete RD, and was retained for 14 days. OPN expression increased in microglial cells 3–7 days after RD, and decreased by 14 days in the detached and border regions. Although OPN was not expressed in the intact region, morphologically activated microglial cells were observed. These retinal glial cell responses and photoreceptor degeneration in the border and intact regions suggest that the effects of RD in the border and intact retinal regions need to be understood further.