Physical fitness changes in adolescents due to social distancing during the coronavirus disease pandemic in Korea
Background At least 60 min of moderate-intensity physical activity per day is recommended for physical and mental health of adolescents. Schools are one of the most suitable places for promoting students’ health as it is a place where vigorous physical activity occurs. However, the physical activity of students is threatened because schools are closed worldwide owing to the coronavirus disease (COVID-19) outbreak in 2019. Therefore, this study aimed to analyze the physical fitness changes in 27,782 Korean adolescents during the pandemic and present alternative education and health policies to the school. Methods We included 29,882 middle school students (age: 13–15 years; males: 14,941, females: 12,841) in Korea from 2019 to 2021 . Participants’ physical fitness at school was measured using the physical activity promotion system (PAPS) manual developed to measure students’ physical fitness. Physical fitness variables included body mass index (BMI), 20 m shuttle run, handgrip strength, sit-and-reach, and 50 m run. Results The COVID-19 pandemic has had a negative impact on the BMI and cardiorespiratory endurance of Korean middle school students. Specifically, male students’ BMI increased, while body composition, cardiorespiratory endurance, and grip strength decreased significantly. Female students showed significant decreases in BMI and sit-and-reach test scores. It is clear that the physical fitness level of adolescents decreased by a greater degree after the COVID-19 pandemic than before, and the decrease in the physical fitness level of male students was noticeable. Therefore, a lesson strategy should be prepared that considers the contents and methods of physical education classes to improve the physical fitness level of male and female adolescents. Conclusions Fitness-based classes suitable for online methods should be urgently added as alternative physical education classes to prepare for the second COVID-19 outbreak. In addition, it is necessary to create an environment in which physical activity is a possibility in physical education classes, in any situation using artificial intelligence and virtual reality.
Lee et al. (2022) Physical fitness changes in adolescents due to social distancing during the coronavirus disease pandemic in Korea. PeerJ 10:e14494 https://doi.org/10.7717/peerj.14494
Genetic diversity of Venturia inaequalis isolates from the scabs in apple trees in Gansu Province, China, using AFLP markers
Apple scab is a serious disease that restricts the growth of cultivated apples. The objective of this study is to investigate the genetic variations and genetic structure of Venturia inaequalis in Gansu Province, China. 108 isolates of the pathogen V. inaequalis from the Jingning, Lingtai, Jingchuan, Xifeng, Ning and Maiji regions were collected, and their genetic diversity was analyzed using AFLP molecular marker technique. The results showed that genetic diversity was present among the isolates but was not statistically significant. Genetic distance values ranged from 0.0095 to 0.0762. Cluster analysis results showed that the 108 isolates could be divided into two clusters using a similarity coefficient of 0.69. A total of 104 isolates were contained in cluster I while four isolates were contained in Cluster II. From the AMOVA analysis, 98% of variations were observed within the same region, while 2% were observed across different regions. The analysis of population structure showed that 108 isolates had two common ancestors, with the Jingning isolates mainly being derived from the red ancestor. PCoA analysis showed that the Jingning isolates were independent to a certain extent. The different geographical location caused the genetic difference of the isolates. The genetic diversity of apple scab in Gansu Province is greatly aided by this work, which also offers a theoretical foundation for the use of molecular markers in assisted breeding to create novel resistant types.
Lü et al. (2022) Genetic diversity of Venturia inaequalis isolates from the scabs in apple trees in Gansu Province, China, using AFLP markers. PeerJ 10:e14512 https://doi.org/10.7717/peerj.14512
Metal tolerance capacity and antioxidant responses of new Salix spp. clones in a combined Cd-Pb polluted system
To investigate the physiochemical characteristics of two new clones, Salix matsudana ‘J172’ (A7) and Salix matsudana ‘Yankang1’ (A64) in combined Cd-Pb contaminated systems, a hydroponic experiment was designed. The plant biomass, photosynthesis, antioxidant responses and the accumulation of metals in different plant parts (leaf, stem, and root) were measured after 35-day treatments with Cd (15, 30 µM) and Pb (250, 500 µM). The results showed that exposure to Cd-Pb decreased the biomass but increased the net photosynthetic rate for both A7 and A64, demonstrating that photosynthesis may be one of the metabolic processes used to resist Cd-Pb stress. Compared with control, roots exposed to Cd-Pb had higher activity of superoxide dismutase and more malondialdehyde concentrations, which indicated the roots of both clones were apt to be damaged. The concentrations of soluble protein were obviously higher in the roots of A64 than A7, indicating the roles of the antioxidative substance were different between two willow clones. Soluble protein also had significant relationship with translocation factors from accumulation in roots of A64, which illustrated it played important roles in the tolerance of A64 roots to heavy metals. The roots could accumulate more Pb rather than transport to the shoots compared with Cd. The tolerance index was more than 85% on average for both clones under all the treatments, indicating their tolerance capacities to the combined stress of Cd and Pb are strong under the tested metal levels. Both clones are the good candidates for phytoremediation of Cd and Pb by the root filtration in the combined contamination environment.
Environmental Contamination and Remediation
Zhang et al. (2022) Metal tolerance capacity and antioxidant responses of new Salix spp. clones in a combined Cd-Pb polluted system. PeerJ 10:e14521 https://doi.org/10.7717/peerj.14521
Effect of hyperglycemia on the immune function of COVID-19 patients with type 2 diabetes mellitus: a retrospective study
Purpose To analyze the clinical characteristics and immune function parameters and to explore the effect of hyperglycemia on the immune function in patients with Corona Virus Disease 2019 (COVID-19) with type 2 diabetes mellitus (T2DM). Methods This retrospective study included patients with COVID-19 with T2DM hospitalized in Renmin Hospital of Wuhan University between January 31, 2020, and February 10, 2020. The clinical data were collected and patients were divided into a well-controlled group (blood glucose 3.9–10.0 mmol/L) and a poorly-controlled group (blood glucose >10.0 mmol/L). The differences in routine blood tests, peripheral lymphocyte subsets, humoral immune components, C-reactive protein (CRP) level, and cytokines were compared, and the correlation between blood glucose and immune parameters as well as the severity of the disease was analyzed. Results A total of 65 patients with COVID-19 and T2DM were included in the final analysis. Compared with the well-controlled group, patients in the poorly-controlled group had decreased lymphocytes, CD16+ 56+ NK cells, CD3+ T cells, CD8+ T cells and increased neutrophil percentage, IL-6 levels, CRP levels and serum concentration of IgA. Blood glucose was inversely correlated with CD16+ 56+ NK cells, CD3+ T cells, CD4+ T cells, and CD8+ T cells and positively correlated with IL-6 and CRP levels. There was a positive correlation between blood glucose and the severity of the COVID-19. Conclusion Hyperglycemia will aggravate the immune dysfunction of COVID-19 patients with T2DM and affect the severity of COVID-19.
Wang et al. (2022) Effect of hyperglycemia on the immune function of COVID-19 patients with type 2 diabetes mellitus: a retrospective study. PeerJ 10:e14570 https://doi.org/10.7717/peerj.14570
Mitochondria and chloroplasts function in microalgae energy production
Microalgae are organisms that have the ability to perform photosynthesis, capturing CO2 from the atmosphere to produce different metabolites such as vitamins, sugars, lipids, among others, many of them with different biotechnological applications. Recently, these microorganisms have been widely studied due to their possible use to obtain clean energy. It has been postulated that the growth of microalgae and the production of high-energy metabolites depend on the correct function of cellular organelles such as mitochondria and chloroplasts. Thus, the development of different genetic tools to improve the function of these organelles is of high scientific and technological interest. In this paper we review the recent advances in microalgae engineering and the role of cellular organelles in order to increase cell productivity and biomass.
Gomez-Casati et al. (2022) Mitochondria and chloroplasts function in microalgae energy production. PeerJ 10:e14576 https://doi.org/10.7717/peerj.14576
Functional groups of Afrotropical EPT (Ephemeroptera, Plecoptera and Trichoptera) as bioindicators of semi-urban pollution in the Tsitsa River Catchment, Eastern Cape, South Africa
We examined the distribution patterns of Ephemeroptera, Plecoptera, and Trichoptera functional feeding groups (EPT FFGs) in five streams that drain semi-urban landscapes in the Tsitsa River catchment, Eastern Cape Province of South Africa. We undertook macroinvertebrate and physicochemical analysis over four seasons between 2016 and 2017 at eight sites in three land-use categories (Sites 1, 2 and 3), representing an increasing gradient of semi-urban pollution. Five EPT FFGs (shredders, grazers/scrapers, predators, collector-gatherers and collector-filterers) were fuzzy coded and analyzed using RLQ-R (environmental characteristics of samples), L (taxa distribution across samples) and Q (species traits) and fourth-corner analyses. Physicochemical variables, including phosphate-phosphorus, total inorganic nitrogen and temperature, were the most influential variables that significantly influenced the distribution patterns of EPT FFGs in the Tsitsa River. RLQ and the fourth-corner model revealed varying responses of FFGs to semi-urban pollution. Of the five FFGs, collectors were the most abundant EPT FFGs in the study area, exhibiting disparate responses to disturbances, with collector-gatherers associated with impacted sites and significantly associated with phosphate-phosphorus. On the other hand, collector-filterers decreased with increasing semi-urban disturbance and exhibited a significant negative association with phosphate-phosphorus, total inorganic nitrogen and temperature. Overall, this study provides further insights into the environmental factors that influence the distribution patterns of FFGs in Afrotropical streams and the potential use of FFGs as indicators of anthropogenic pollution in tropical streams and rivers.
Akamagwuna et al. (2022) Functional groups of Afrotropical EPT (Ephemeroptera, Plecoptera and Trichoptera) as bioindicators of semi-urban pollution in the Tsitsa River Catchment, Eastern Cape, South Africa. PeerJ 10:e13970 https://doi.org/10.7717/peerj.13970
Impacts of river fragmentation on limiting individual dietary specialization of Amazonian predatory fish
Individual dietary specialization is one of the factors that promotes variation in resource use at the individual level. Here we used stable isotope analysis of multiple tissues with different turnover rates to examine the degree of individual specialization in two sub-populations of the predator Cichla temensis inhabiting both fragmented and undammed rivers within the Uatumã River basin of the Amazon. Our results showed that the undammed river provides better conditions to promote individual dietary specialization than the fragmented river. This study contributes to the understanding of how specific life history characteristics of populations of generalist predators are impacted by fragmentation within megadiverse environments such as the Amazon basin.
Aguiar-Santos et al. (2022) Impacts of river fragmentation on limiting individual dietary specialization of Amazonian predatory fish. PeerJ 10:e14266 https://doi.org/10.7717/peerj.14266
Neospongodes atlantica, a potential case of an early biological introduction in the Southwestern Atlantic
Soft corals (Anthozoa: Octocorallia) are discreet components in the Southwestern Atlantic reef communities. In Brazil, the native octocoral shallow-reef fauna is mostly represented by gorgonians. Consequently, except for the nephtheid Neospongodes atlantica, most of the known soft corals from this region are considered non-indigenous. Hitherto, the monotypic genus Neospongodes, which was proposed in the early 1900s, has been considered to be endemic to the Northeastern Brazilian coast. Herein, based on in situ records, we show that N. atlantica is a substrate generalist that has been probably expanding its distribution by dominating extensive shallow and mesophotic sandy and reef bottoms, generally outcompeting other reef benthic organisms, including Brazilian endemic species. Based on previously unidentified museum specimens, new records, and a broad literature review, we provide the most comprehensive modelling of the potential distribution of this species in the Southwestern Atlantic. Based on molecular inference supported by in-depth morphological analysis, the probable non-indigenous and, therefore, ancient introduction of N. atlantica in Brazilian waters is discussed. Finally, these results support that Neospongodes and the Indo-Pacific Stereonephthya are synonyms, which led us to propose the latter as taxonomically invalid.
Cordeiro et al. (2022) Neospongodes atlantica, a potential case of an early biological introduction in the Southwestern Atlantic. PeerJ 10:e14347 https://doi.org/10.7717/peerj.14347
Using a real-world network to model the trade-off between stay-at-home restriction, vaccination, social distancing and working hours on COVID-19 dynamics
Background Human behaviour, economic activity, vaccination, and social distancing are inseparably entangled in epidemic management. This study aims to investigate the effects of various parameters such as stay-at-home restrictions, work hours, vaccination, and social distance on the containment of pandemics such as COVID-19. Methods To achieve this, we have developed an agent based model based on a time-dynamic graph with stochastic transmission events. The graph is constructed from a real-world social network. The edges of graph have been categorized into three categories: home, workplaces, and social environment. The conditions needed to mitigate the spread of wild-type COVID-19 and the delta variant have been analyzed. Our purposeful agent based model has carefully executed tens of thousands of individual-based simulations. We propose simple relationships for the trade-offs between effective reproduction number (Re), transmission rate, working hours, vaccination, and stay-at-home restrictions. Results We have found that the effect of a 13.6% increase in vaccination for wild-type (WT) COVID-19 is equivalent to reducing four hours of work or a one-day stay-at-home restriction. For the delta, 20.2% vaccination has the same effect. Also, since we can keep track of household and non-household infections, we observed that the change in household transmission rate does not significantly alter the Re. Household infections are not limited by transmission rate due to the high frequency of connections. For the specifications of COVID-19, the Re depends on the non-household transmissions rate. Conclusions Our findings highlight that decreasing working hours is the least effective among the non-pharmaceutical interventions. Our results suggest that policymakers decrease work-related activities as a last resort and should probably not do so when the effects are minimal, as shown. Furthermore, the enforcement of stay-at-home restrictions is moderately effective and can be used in conjunction with other measures if absolutely necessary.
Nashebi et al. (2022) Using a real-world network to model the trade-off between stay-at-home restriction, vaccination, social distancing and working hours on COVID-19 dynamics. PeerJ 10:e14353 https://doi.org/10.7717/peerj.14353
Prevalence of text neck posture, smartphone addiction, and its association with neck disorders among university students in the Kingdom of Saudi Arabia during the COVID-19 pandemic
The smartphone emerges as an inevitable gadget in modern society and its increased usage results in neck disorders among its users. However, the factors associated with neck disorders among smartphone users are ambiguous and less explored in the literature. The purpose of this research was to determine the prevalence of text neck posture, smartphone addiction/overuse, and its association with neck disorders among university students in the Kingdom of Saudi Arabia during the COVID-19 pandemic. A total of 313 university students who were aged 18 years and older, owned a smartphone, and used it during the preceding 12 months participated in this cross-sectional study. A self-administered questionnaire was used to collect data regarding the prevalence of text neck posture, smartphone addiction/overuse, neck disorders, and the level of physical activity. Binary logistic regression was used to determine the association between the prevalence of neck disorders and text neck posture, smartphone addiction/overuse, and level of physical activity. The 12 months prevalence of neck disorders due to smartphone use among the participants was found to be 46%. The neck disorders were more prevalent among participants who reported text neck posture (P < 0.001) and categorized as smartphone-addicted/overuse (P < 0.001). Measures to promote the awareness of healthy use of smartphones including postural education and to decrease its screen time are warranted to reduce neck disorders.
Sirajudeen et al. (2022) Prevalence of text neck posture, smartphone addiction, and its association with neck disorders among university students in the Kingdom of Saudi Arabia during the COVID-19 pandemic. PeerJ 10:e14443 https://doi.org/10.7717/peerj.14443