Associations between lower limb eccentric muscle capability and change of direction speed in basketball and tennis players
Background The ability to perform a quick and rapid change of direction (CoD) is an important determinant of success in a variety of sports. Previous studies have already highlighted that eccentric strength is a dominant predictor of CoD. However, these studies evaluated eccentric strength through a limited number of outcome measures and used small sample sizes. Methods A total of 196 athletes participated in the study. The aim of our study was to investigate: (1) the correlation between eccentric outcome measures derived from different tests (Nordic hamstring exercise (NHE), countermovement jump (CMJ) and flywheel (FW) squats), (2) the association between eccentric outcome measures and CoD 90°, CoD 180°; and (3) proportion of explained variance in CoD performance. Results Very large associations (r = 0.783, p < 0.001) were observed between peak torque during NHE (NHEPT) and force impulse during the eccentric phase of CMJ (CMJFI). Small to moderate correlations were calculated between peak eccentric force in flywheel squats and peak eccentric force in CMJ (r = 0.220–035, p < 0002). All eccentric CMJ outcome measures and NHEPT were reported as moderate negative associations with both CoD tests. Eccentric measures explained 25.1% of the variance in CoD 90° (CMJPF, NHEPT, F0.125 –peak eccentric force during FW squats with 0.125 kg m2 load), while the same outcome measures explained 37.4% of the variance for CoD 180°. Conclusion Our results suggest that different measures of eccentric strength specifically contribute to CoD performance. Therefore, for successful CoD performance, different aspects of eccentric strength training should be considered in testing and training (maximal eccentric strength, eccentric-concentric actions with fast execution).
Smajla et al. (2022) Associations between lower limb eccentric muscle capability and change of direction speed in basketball and tennis players. PeerJ 10:e13439 https://doi.org/10.7717/peerj.13439
Aflatoxin B1 exposure disrupts organelle distribution in mouse oocytes
Aflatoxin B1 (AFB1) is a secondary metabolite produced by the fungus Aspergillus, which is ubiquitous in moldy grain products. Aflatoxin B1 has been reported to possess hepatotoxicity, renal toxicity, and reproductive toxicity. Previous studies have shown that AFB1 is toxic to mammalian oocytes. However, the potential toxicity of AFB1 on the organelles of mouse oocytes is unknown. In this study, we found that exposure to AFB1 significantly reduced mouse oocyte development capacity. Further analysis showed that the endoplasmic reticulum (ER) failed to accumulate around the spindle, and scattered in the cytoplasm under AFB1 exposure. Similar to the ER, the Golgi apparatus showed a uniform localization pattern following AFB1 treatment. In addition, we found that AFB1 exposure caused the condensation of lysosomes in the cytoplasm, presenting as a clustered or spindle peripheral-localization pattern, which indicated that protein modification, transport, and degradation were affected. Mitochondrial distribution was also altered by AFB1 treatment. In summary, our study showed that AFB1 exposure had toxic effects on the distribution of mouse oocyte organelles, which further led to a decline in oocyte quality.
Zhang et al. (2022) Aflatoxin B1 exposure disrupts organelle distribution in mouse oocytes. PeerJ 10:e13497 https://doi.org/10.7717/peerj.13497
Land use/land cover changes in the central part of the Chitwan Annapurna Landscape, Nepal
Background Land use/land cover assessment and monitoring of the land cover dynamics are essential to know the ecological, physical and anthropogenic processes in the landscape. Previous studies have indicated changes in the landscape of mid-hills of Nepal in the past few decades. But there is a lack of study in the Chitwan Annapurna Landscape; hence, this study was carried out to fill in study gap that existed in the area. Methods This study evaluates land use/land cover dynamics between 2000 to 2020 in the central part of the Chitwan Annapurna Landscape, Nepal by using Landsat images. The Landsat images were classified into eight different classes using remote sensing and geographic information system (GIS). The accuracy assessment of classified images was evaluated by calculating actual accuracy, producer’s accuracy, user’s accuracy and kappa coefficient based on the ground-truthing points for 2020 and Google Earth and topographic maps for images of 2010 and 2000. Results The results of land use/land cover analysis of Landsat image 2020 showed that the study area was composed of grassland (1.73%), barren area (1.76%), riverine forest (1.93%), water body (1.97%), developed area (4.13%), Sal dominated forest (15.4%), cropland (28.13%) and mixed forest (44.95%). The results of land cover change between 2000 to 2020 indicated an overall increase in Sal dominated forest (7.6%), developed area (31.34%), mixed forest (37.46%) and decrease in riverine forest (11.29%), barren area (20.03%), croplands (29.87%) and grasslands (49.71%). The classification of the images of 2000, 2010 and 2020 had 81%, 81.6% and 84.77% overall accuracy, respectively. This finding can be used as a baseline information for the development of a proper management plan to protect wildlife habitats and forecasting possible future changes, if needed.
Spatial and Geographic Information Science
Adhikari et al. (2022) Land use/land cover changes in the central part of the Chitwan Annapurna Landscape, Nepal. PeerJ 10:e13435 https://doi.org/10.7717/peerj.13435
Determining the optimal areas of effort in terms of force and force-velocity based on the functional state of the neuromuscular system in the training of elite female judokas
Background The evaluation of the functional state of the neuromuscular system (NMS) in elite female judokas according to the muscular activity indices is influenced by the force (F) and force-velocity (F-V) efforts. The implementation of the individual correction plan in the elite female judokas’ process of instruction and training must be based on the accurate determination of the force and force-velocity effort areas throughout the training and competitive periods. Methods The research involved 44 elite female judokas, divided in to two experimental groups (A, C) and two control groups (B, D). To diagnose the NMS, 21 elite female judokas were evaluated, belonging to different classification categories, divided into three groups: group I–category I (Cat. I), group II–candidates for Masters of Sports (CMS) and group III—Masters of Sports (MS).The evaluation of NMS was performed at the end of each two-week cycle, using 3 tests: Tmax—time to reach the maximum muscle contraction, (msec); Fy –examination of elasticity indices in different muscles, (Hz); J–explosive muscular strength, (kg/s). Measurements were made for six muscle groups and 9 indices of fitness tests: 5 force tests (F) and 4 force-velocity tests (F-V). The research was carried out during 24 cycles, each one lasting two weeks: 12 training cycles and 12 competitive ones. Each cycle lasted two weeks. During the research, the model plan of training for F and F-V was used, determining the optimal areas of F and F-V training efforts in the preparation and competitive periods. In the experimental groups (A and C), according to the data of judokas’ NMS functional state evaluation, the individual correction of the F and F-V efforts was performed every two weeks. As for the control groups (B, D), traditional methods of training were used. Results The NMS evaluation of the female judokas was made every two weeks and the level of correlation of Tmax, Fy and J indices was determined. The value of the Fy index at F effort is 32% in group I, 30% - in group II, 27% - in group III, 28–30% at the effort of F-V. The total number of corrections in group A: 79 negative corrections and 59 positive corrections, while in group C: 65 negative corrections and 89 positive ones. Within the F-V effort, the number of effort corrections in group A was: 68 negative corrections and 92 positive; in group C - 81 positive and 78 negative corrections. The female judokas’ results in the final stage of EG–A were significantly improved in F indices by 52.15%, F-V by 6.22% and 6.18%. In the EG–C, the F increased considerably by 7.52%, F-V by 5.67% and 7.20%. These results characterize the level of physical training. Conclusion The functional state of the NMS in elite judokas, determined according to the temporal indices of reaching the maximal muscular contraction, the muscle explosive strength and the muscles elasticity, is subjected to dynamics under the influence of force effort and force-velocity effort.
Manolachi et al. (2022) Determining the optimal areas of effort in terms of force and force-velocity based on the functional state of the neuromuscular system in the training of elite female judokas. PeerJ 10:e13468 https://doi.org/10.7717/peerj.13468
The superior response speed of table tennis players is associated with proactive inhibitory control
Objective To explore the mechanism behind the faster volitional reaction time (RT) of open skill sports athletes from the perspective of proactive inhibitory control, with the hypothesis that the superior response speed of athletes from open skill sports is related to their enhanced capacity for releasing inhibition. Methods Participants were divided into two groups, an experimental group of 27 table tennis players and a control group of 27 non-athletes. By manipulating cue–target onset asynchrony (CTOA) in a simple cue-target detection task, the timing of target presentation occurred in different phases of the disinhibition process. The time needed for disinhibition were compared between groups. Results For the experimental group, RT varied with CTOA at delays less than 200 ms; for CTOAs greater than 200 ms, RTs were not significantly different. For the control group, RT varied with CTOA for delays as long as 300 ms. Conclusions Table tennis players took less time (200 ms) than non-athletes (300 ms) to complete the disinhibition process, which might partly explain their rapid response speed measured in unpredictable contexts. Significance The study provided evidence for disinhibition speed as a new index to assess the capacity of proactive inhibitory control, and provided a new perspective to explore the superior RT of athletes from open skill sports. We also offered support for the fundamental cognitive benefits of table tennis training.
Zhu et al. (2022) The superior response speed of table tennis players is associated with proactive inhibitory control. PeerJ 10:e13493 https://doi.org/10.7717/peerj.13493
The variability of emotions, physical complaints, intention, and self-efficacy: an ecological momentary assessment study in older adults
Background Many theoretical frameworks have been used in order to understand health behaviors such as physical activity, sufficient sleep, healthy eating habits, etc. In most research studies, determinants within these frameworks are assessed only once and thus are considered as stable over time, which leads to rather ‘static’ health behavior change interventions. However, in real-life, individual-level determinants probably vary over time (within days and from day to day), but currently, not much is known about these time-dependent fluctuations in determinants. In order to personalize health behavior change interventions in a more dynamic manner, such information is urgently needed. Objective The purpose of this study was to explore the time-dependent variability of emotions, physical complaints, intention, and self-efficacy in older adults (65+) using Ecological Momentary Assessment (EMA). Methods Observational data were collected in 64 healthy older adults (56.3% men; mean age 72.1 ± 5.6 years) using EMA. Participants answered questions regarding emotions (i.e., cheerfulness, relaxation, enthusiasm, satisfaction, insecurity, anxiousness, irritation, feeling down), physical complaints (i.e., fatigue, pain, dizziness, stiffness, shortness of breath), intention, and self-efficacy six times a day for seven consecutive days using a smartphone-based questionnaire. Generalized linear mixed models were used to assess the fluctuations of individual determinants within subjects and over days. Results A low variability is present for the negative emotions (i.e., insecurity, anxiousness, irritation, feeling down) and physical complaints of dizziness and shortness of breath. The majority of the variance for relaxation, satisfaction, insecurity, anxiousness, irritation, feeling down, fatigue, dizziness, intention, and self-efficacy is explained by the within subjects and within days variance (42.9% to 65.8%). Hence, these determinants mainly differed within the same subject and within the same day. The between subjects variance explained the majority of the variance for cheerfulness, enthusiasm, pain, stiffness, and shortness of breath (50.2% to 67.3%). Hence, these determinants mainly differed between different subjects. Conclusions This study reveals that multiple individual-level determinants are time-dependent, and are better considered as ‘dynamic’ or unstable behavior determinants. This study provides us with important insights concerning the development of dynamic health behavior change interventions, anticipating real-time dynamics of determinants instead of considering determinants as stable within individuals.
Maes et al. (2022) The variability of emotions, physical complaints, intention, and self-efficacy: an ecological momentary assessment study in older adults. PeerJ 10:e13234 https://doi.org/10.7717/peerj.13234
Does the landscape functionality approach provide insight into rangeland conditions in the Tanqua Karoo region, South Africa?
The harsh environmental conditions coupled with a long history of overgrazing have altered the ecology of the arid Tanqua Karoo rangelands in South Africa, which necessitates rehabilitation. However, a suitable method for monitoring rangeland function over time is required for sustainable management. In this study, vegetation characteristics and landscape function indices were used to rate and compare rangeland conditions in 43 sites distributed among three vegetation types: Tanqua Karoo, Tanqua Wash Riviere, and Tanqua Escarpment Shrubland, which occupy different landscapes in the Tankwa Karoo National Park. The results showed low values of vegetation volume (mean of 10.1 m3 per 100 m−2) and low vegetated patches (mean of 29% patches vs 71% fetches). The overall landscape function indices (soil stability, water infiltration, and nutrient recycling) were low and amounted to 55%, 28%, and 17%, respectively. Amongst the various examined landscapes, the escarpment had the highest values of most of the measured landscape functionality parameters, and the open plains had the lowest values. This revealed high heterogeneity of soil properties and vegetation characteristics amongst the different vegetation types, mainly influenced by altitudinal gradients. The higher-lying landscapes on the escarpment are relatively more functional and more susceptible to improvement when compared to the lower-lying landscapes on the plains. The landscape functionality approach (LFA) approach demonstrated that some of the examined vegetation types had insignificant improvement in landscape functionality likely not to improve in the near term due to existing low patchiness, higher fetch space and low LFA indices coupled with the low annual rainfall of the region. The landscape functionality approach has provided a suitable benchmark for assessing and monitoring the diverse vegetation types in this arid part of the world.
Saaed et al. (2022) Does the landscape functionality approach provide insight into rangeland conditions in the Tanqua Karoo region, South Africa?. PeerJ 10:e13305 https://doi.org/10.7717/peerj.13305
Influence of the COVID-19 pandemic on breastfeeding support for healthy mothers and the association between compliance with WHO recommendations for breastfeeding support and exclusive breastfeeding in Japan
Background Professional breastfeeding support contributes to maternal and child health. However, the influence of the current coronavirus disease 2019 (COVID-19) pandemic on breastfeeding support has not been carefully examined. Therefore, we assessed maternal breastfeeding intention and professional breastfeeding support before and during the pandemic. We further examined the association of compliance with World Health Organization (WHO) recommendations for professional breastfeeding support with exclusive breastfeeding during the pandemic. Methods This cross-sectional, internet-based, questionnaire study analyzed data from 484 healthy women with live singleton births between 15 October 2019 and 25 October 2020 in Japan. A delivery before 5 March 2020 was classified as a before-pandemic delivery (n = 135), and a delivery after 6 March 2020 was a during-pandemic delivery (n = 349). Among the ten breastfeeding support steps recommended by the WHO, we assessed the five steps that are measurable by maternal self-report and would likely exhibit variability. Receipt of a free formula sample or invitation to a free sample campaign by the time of survey was also asked. Infant feeding status at the time of the survey was measured among women with infants younger than 5 months, which was a subgroup of mothers who delivered during the pandemic. Mothers were asked what was given to infants during the 24 h before the survey and when nothing other than breast milk was given, the status was classified as exclusive breastfeeding. Results While 82.2% of women with a delivery before the pandemic intended to breastfeed, the rate was 75.6% during the pandemic (p = 0.120). The average number of breastfeeding support steps received was 3.24 before the pandemic but it was 3.01 during the pandemic (p = 0.069). In particular, rooming-in was less frequent (39.3% before vs. 27.8% during the pandemic, p = 0.014). Among mothers with infants younger than 5 months who had a delivery during the pandemic (n = 189), only 37.0% (n = 70) reported exclusively breastfeeding during the 24 h before completing the survey. Multiple logistic regression analysis indicated that receiving support for all five steps was positively associated with exclusive breastfeeding during the 24 h before the survey (adjusted odds ratio 4.51; 95% CI [1.50–13.61]). Receipt of a free formula sample or invitation to a free sample campaign was negatively associated with exclusive breastfeeding (adjusted odds ratio 0.43; 95% CI [0.19–0.98]). Other factors related to non-exclusive breastfeeding were older maternal age, lower education level, primiparity, and no breastfeeding intention. Conclusions The pandemic weakened breastfeeding support for healthy women in Japan; however, support practice that adhered to WHO recommendations appeared to be effective during the pandemic.
Nanishi et al. (2022) Influence of the COVID-19 pandemic on breastfeeding support for healthy mothers and the association between compliance with WHO recommendations for breastfeeding support and exclusive breastfeeding in Japan. PeerJ 10:e13347 https://doi.org/10.7717/peerj.13347
Identification of vaccine targets & design of vaccine against SARS-CoV-2 coronavirus using computational and deep learning-based approaches
An unusual pneumonia infection, named COVID-19, was reported on December 2019 in China. It was reported to be caused by a novel coronavirus which has infected approximately 220 million people worldwide with a death toll of 4.5 million as of September 2021. This study is focused on finding potential vaccine candidates and designing an in-silico subunit multi-epitope vaccine candidates using a unique computational pipeline, integrating reverse vaccinology, molecular docking and simulation methods. A protein named spike protein of SARS-CoV-2 with the GenBank ID QHD43416.1 was shortlisted as a potential vaccine candidate and was examined for presence of B-cell and T-cell epitopes. We also investigated antigenicity and interaction with distinct polymorphic alleles of the epitopes. High ranking epitopes such as DLCFTNVY (B cell epitope), KIADYNKL (MHC Class-I) and VKNKCVNFN (MHC class-II) were shortlisted for subsequent analysis. Digestion analysis verified the safety and stability of the shortlisted peptides. Docking study reported a strong binding of proposed peptides with HLA-A*02 and HLA-B7 alleles. We used standard methods to construct vaccine model and this construct was evaluated further for its antigenicity, physicochemical properties, 2D and 3D structure prediction and validation. Further, molecular docking followed by molecular dynamics simulation was performed to evaluate the binding affinity and stability of TLR-4 and vaccine complex. Finally, the vaccine construct was reverse transcribed and adapted for E. coli strain K 12 prior to the insertion within the pET-28-a (+) vector for determining translational and microbial expression followed by conservancy analysis. Also, six multi-epitope subunit vaccines were constructed using different strategies containing immunogenic epitopes, appropriate adjuvants and linker sequences. We propose that our vaccine constructs can be used for downstream investigations using in-vitro and in-vivo studies to design effective and safe vaccine against different strains of COVID-19.
Abbasi et al. (2022) Identification of vaccine targets & design of vaccine against SARS-CoV-2 coronavirus using computational and deep learning-based approaches. PeerJ 10:e13380 https://doi.org/10.7717/peerj.13380
Potential and functional prediction of six circular RNAs as diagnostic markers for colorectal cancer
Background Circular RNAs (circRNAs) have been discovered in colorectal cancer (CRC), but there are few reports on the expression distribution and functional mining analysis of circRNAs. Methods Differentially expressed circRNAs in CRC tissues and adjacent normal tissues were screened and identified by microarray and qRT-PCR. ROC curves of the six circRNAs were analyzed. A series of bioinformatics analyses on differentially expressed circRNAs were performed. Results A total of 207 up-regulated and 357 down-regulated circRNAs in CRC were screened, and three top up-regulated and down-regulated circRNAs were chosen to be verified in 33 pairs of CRCs by qRT-PCR. 6 circRNAs showed high diagnostic values (AUC = 0.6860, AUC = 0.8127, AUC = 0.7502, AUC = 0.9945, AUC = 0.9642, AUC = 0.9486 for hsa_circRNA_100833, hsa_circRNA_103828, hsa_circRNA_103831 and hsa_circRNA_103752, hsa_circRNA_071106, hsa_circRNA_102293). A circRNA-miRNA-mRNA regulatory network (cirReNET) including six candidate circRNAs, 19 miRNAs and 210 mRNA was constructed, and the functions of the cirReNET were predicted and displayed via Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses on these mRNAs and protein-protein interaction (PPI) network of the hub genes acquired by string and CytoHubba. Conclusion A cirReNET containing potential diagnostic and predictive indicators of CRCs and several critical circRNA-miRNA-mRNA regulatory axes (cirReAXEs) in CRC were mined, and may provide a novel route to study the mechanism and clinical targets of CRC.
Liu et al. (2022) Potential and functional prediction of six circular RNAs as diagnostic markers for colorectal cancer. PeerJ 10:e13420 https://doi.org/10.7717/peerj.13420