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ABSTRACTLimited amount of information is available for cold-hardy table grape postharvest storage and strategies to extend the storage time. ‘Somerset Seedless’ is a cold-hardy table grape with a potential market for the Upper Midwest and Northern Great Plains. Postharvest treatments were assessed as a possible route to increase cold-hardy table grape shelf-life. In this study, a 1.4% chitosan postharvest treatment was tested on ‘Somerset Seedless’ grapes through 7 weeks of storage with temperature 1–4°C, humidity ≥90%. The effects were compared to two controls: one was diH2O, and the other one was acetic acid. The assessment included grape appearance traits (rachis, decay, mold, scattering, and splitting), physiochemical properties (TSS, pH and total acidity), antioxidant activity, as well as total phenolics and flavonoid content. In general, 1.4% chitosan, 1% acetic acid, and diH2O had a large impact on grape appearance during storage with limited impact on chemistry. Throughout 7 weeks of storage, no significant differences were observed in grape physiochemical and phytochemical changes. Chitosan performed the best for ‘Somerset Seedless’ postharvest storage in regard to the low rate of visible damage. Although acetic acid had similarly positive effects on mold control as chitosan treatment, it caused the highest split rate after 1 week and the highest shatter rate after 5 weeks of storage. Chitosan treated ‘Somerset Seedless’ still met the USDA standard of table grapes after 5 weeks. This study suggests chitosan postharvest treatments may have applications for enhancing the shelf-life of cold-hardy table grapes.

Abstract Background Burnout is usually defined as a state of emotional, physical, and mental exhaustion that affects people in various professions (e.g. physicians, nurses, teachers). The consequences of burnout involve decreased motivation, productivity, and overall diminished well-being. The machine learning-based prediction of burnout has therefore become the focus of recent research. In this study, the aim was to detect burnout using machine learning and to identify its most important predictors in a sample of Hungarian high-school teachers. Methods The final sample consisted of 1,576 high-school teachers (522 male), who completed a survey including various sociodemographic and health-related questions and psychological questionnaires. Specifically, depression, insomnia, internet habits (e.g. when and why one uses the internet) and problematic internet usage were among the most important predictors tested in this study. Supervised classification algorithms were trained to detect burnout assessed by two well-known burnout questionnaires. Feature selection was conducted using recursive feature elimination. Hyperparameters were tuned via grid search with 10-fold cross-validation. Due to class imbalance, class weights (i.e. cost-sensitive learning), downsampling and a hybrid method (SMOTE-ENN) were applied in separate analyses. The final model evaluation was carried out on a previously unseen holdout test sample. Results Burnout was detected in 19.7% of the teachers included in the final dataset. The best predictive performance on the holdout test sample was achieved by random forest with class weigths (AUC = 0.811; balanced accuracy = 0.745, sensitivity = 0.765; specificity = 0.726). The best predictors of burnout were Beck’s Depression Inventory scores, Athen’s Insomnia Scale scores, subscales of the Problematic Internet Use Questionnaire and self-reported current health status. Conclusions The performances of the algorithms were comparable with previous studies; however, it is important to note that we tested our models on previously unseen holdout samples suggesting higher levels of generalizability. Another remarkable finding is that besides depression and insomnia, other variables such as problematic internet use and time spent online also turned out to be important predictors of burnout.

Annamaria Nemes,1 Delia Szok,1 Antal Tibold,2 Gabor Kosa,2 Krisztian Kapus,2 Gyula Berke,3 Zoltan Banko,3 Gergely Feher2 1Department of Neurology, Szent-Györgyi Albert Medical School, University of Szeged, Szeged, 6720, Hungary; 2Centre for Occupational Medicine, Medical School, University of Pécs, Pécs, 7627, Hungary; 3Faculty of Law and Political Sciences, ELKH-PTE-NKE Research Group on Comparative and European Employment Policy and Labour Law, University of Pécs, Pécs, 7627, HungaryCorrespondence: Gergely Feher, Tel +36-72/518-523, Fax +36-72/518-521, Email feher.gergely@pte.huIntroduction: The internet has become a part of everyday life, and during the COVID-19 pandemic the rate of internet use has raised even higher, which increases the possibility of compulsive and problematic use leading to the acceptance of online misbeliefs and conspiration theories. This cross-sectional study aimed to explore the relationship between COVID-19-related misconceptions and internet addiction among adult recreational online gamers.Methods: A sample of 1671 recreational video game users completed the online survey (male: n = 1522 (91.08%), mean age = 21.83, SD = 4.18; female: n = 149 (8.91%), mean age = 24.33, SD = 8.38). Demographic questions, risk factors and health-related questions, internet use and addiction were measured alongside a short questionnaire about common COVID-19-related topics, such as its origin and risk of infection.Results: Out of all participants 248 (14.8%) answered all the COVID-19-related questions properly, thus having no misconceptions, while 545 (32.6%) had one wrong answer, 532 (31.8%) had 2 wrong answers, 251 (15.0%) had 3 wrong answers, 78 (4.7%) had 4 wrong answers and 17 (1.0%) had 5 wrong answers. Significant factors to a higher number of COVID-misconceptions were time spent studying (χ 2 (35,1671) = 63.86, p = 0.002), marital status (χ 2 (15,1671) = 30.65 p = 0.01) and secondary employment (χ 2 (51,671) = 14.88, p = 0.01). Although 17.1% of the participants reached the threshold score for internet addiction, the predictors of COVID-19 misconceptions were marital status (β = − 0.06, p = 0.01) and time spent studying (β = 0.05, p = 0.03), while neither daily internet use, internet addiction scores or risk factors predicted these misconceptions in a linear regression model.Discussion: Our study concludes that Internet addiction did not directly influence misconceptions about the COVID-19 pandemic in this population despite the surprisingly high rate of problematic users.Keywords: internet addiction, COVID-19, risk factor, depression, online gaming

Abstract Introduction Problematic usage of the internet (PUI) is perhaps one of the most frequently studied phenomena of the 21st century receiving increasing attention in both scientific literature and the media. Despite intensive research there have been relatively few meaningful studies among elementary school students in Hungary and worldwide, who may be considered as a high-risk population with regard to problematic internet use. The aim of our study was to carry out a complex research focusing on the prevalence and risk factors of PUI among elementary school children aged 10–15 years (Grade 5–8). Methods Demographics included were gender, age, place of stay, type of residence, family type, parental education, start of internet use, used devices, daily internet use, purpose of internet use, internet accounts, ways of keeping in touch with friends and sporting activities. PUI was evaluated using the paper-based version of the Potentially Problematic Use of the Internet Questionnaire. Results Overall, 2000 paper-based questionnaires were successfully delivered and the final analysis included 1168 responses (overall response rate 58.4%). Mean age was 12.55 ± 1.24 years. Female gender (OR = 2.760, p = 0,006, CI 95% 0.065 to 0.384), younger age (11–12 years) (OR = 3.812, p

Uvod: Vpliv porodnega položaja na tveganje za poškodbo presredka, ki je odvisen od lokalnih in regionalnih babiških praks, kot so ročna tehnika zaščite presredka, razne stopnje epiziotomije in operativnih porodov itd., še ni zadostno raziskan. Namen raziskave je bil v eni od slovenskih porodnišnic preučiti morebitno povezavo med porodnim položajem ob iztisu ploda in pojavnostjo poškodbe presredka. Metode: V retrospektivno kohortno raziskavo smo vključili 625 porodnic, ki so leta 2021 rodile v Splošni bolnišnici Jesenice. Izključili smo večplodne nosečnosti, prezgodnje porode, porode s plodom v medenični ali okcipito-posteriorni vstavi, vakuumske ekstrakcije ploda in epiziotomije. Z multiplo logistično regresijo smo preučili, ali je bil položaj porodnice ob iztisu ploda (leže na hrbtu (n = 66), leže na boku (n = 404) ali vsi ostali položaji (n = 155)) neodvisno povezan s pojavnostjo poškodbe presredka. Rezultati:Pri 363 porodnicah (58 %) ni prišlo do poškodbe presredka. Pri 192 (73 %) je prišlo do poškodbe prve stopnje, pri 59 (23 %) do poškodbe druge stopnje in pri 11 (4 %) do poškodbe presredka tretje ali četrte stopnje. Porodni položaj ob iztisu ploda ob upoštevanju drugih potencialnih dejavnikov tveganja ni bil statistično pomembno povezan s tveganjem za poškodbo presredka: razmerje obetov (RO) 0,691, 95% interval zaupanja (IZ) – 0,401–1,191 za položaj na boku; RO 0,710, 95% IZ – 0,386–1,306 za ostale položaje v primerjavi s porajanjem leže na hrbtu. Diskusija in zaključek: V slovenski porodnišnici z visokim odstotkom porodnic, ki ne rodijo leže na hrbtu, porodni položaj ob iztisu ploda ni neodvisni dejavnik tveganja za nastanek poškodbe presredka

Polycystic kidney disease (PKD) is characterized by extensive cyst formation and progressive fibrosis. However, the molecular mechanisms whereby the loss/loss-of-function of Polycystin 1 or 2 (PC1/2) provokes fibrosis are largely unknown. The small GTPase RhoA has been recently implicated in cystogenesis, and we identified the RhoA/cytoskeleton/myocardin-related transcription factor (MRTF) pathway as an emerging mediator of epithelium-induced fibrogenesis. Therefore, we hypothesized that MRTF is activated by PC1/2 loss and plays a critical role in the fibrogenic reprogramming of the epithelium. The loss of PC1 or PC2, induced by siRNA in vitro, activated RhoA and caused cytoskeletal remodeling and robust nuclear MRTF translocation and overexpression. These phenomena were also manifested in PKD1 (RC/RC) and PKD2 (WS25/−) mice, with MRTF translocation and overexpression occurring predominantly in dilated tubules and the cyst-lining epithelium, respectively. In epithelial cells, a large cohort of PC1/PC2 downregulation-induced genes was MRTF-dependent, including cytoskeletal, integrin-related, and matricellular/fibrogenic proteins. Epithelial MRTF was necessary for the paracrine priming of the fibroblast–myofibroblast transition. Thus, MRTF acts as a prime inducer of epithelial fibrogenesis in PKD. We propose that RhoA is a common upstream inducer of both histological hallmarks of PKD: cystogenesis and fibrosis.

Abstract Background Advances in synthetic biology will require spatio-temporal regulation of biological processes in heterologous host cells. We develop a light-switchable, two-hybrid interaction in yeast, based upon the Arabidopsis proteins PHYTOCHROME A and FAR-RED ELONGATED HYPOCOTYL 1-LIKE. Light input to this regulatory module allows dynamic control of a light-emitting LUCIFERASE reporter gene, which we detect by real-time imaging of yeast colonies on solid media. Results The reversible activation of the phytochrome by red light, and its inactivation by far-red light, is retained. We use this quantitative readout to construct a mathematical model that matches the system's behaviour and predicts the molecular targets for future manipulation. Conclusion Our model, methods and materials together constitute a novel system for a eukaryotic host with the potential to convert a dynamic pattern of light input into a predictable gene expression response. This system could be applied for the regulation of genetic networks - both known and synthetic.

In an article published in IEEE Access in 2020, researchers present an approach to using TLA+ for the formal verification of whether a network of SDN (Software-Defined Networking) switches implements the filtering rules of a given monolithic firewall. The distributed as well as monolithic firewalls are specified with TLA+. It is shown that the correctness of the former with respect to the latter can be verified automatically by using the TLC model checker. The main contributions of this paper are the following improvements of that approach. Firstly, by specifying switches without using any variables, the time needed for the model checking is reduced significantly. For example, the verification of the same networks takes a few seconds with the new approach and does not end after several hours with the previous one. Secondly, the following problem is solved. With the latter, if a monolithic firewall allows a packet to pass through, all the paths in the distributed firewall which the packet is routed on must allow the same. Otherwise, the model checker proclaims the distributed firewall to be in error. We present an additional approach to the verification, which gives a positive answer if at least one of the paths allows the packet to pass through.

Abstract Background Burnout is one of the most extensively studied phenomena of the twenty-first century; which has been extensively studied among helping professions, although it can be broadened to several other types of occupation. Based on our knowledge and literature search, no similar studies have been carried out among postal workes to date. Methods This cross-sectional questionnaire-based epidemiological study was carried out between May 2021 and January 2022 in five counties in Hungary with the recruitment of postal delivery workers focusing on (1) the prevalence of burnout among postal delivery workers; (2) including the role of demographic parameters, duration of employment as well as the presence of secondary employment; (3) and also analyzed the role of several risk factors and medical conditions; (4) and we also examined the possible association between depression, insomnia and quality of life and burnout. Results Overall 1300 questionnaires were successfully delivered and 1034 responses received (response rate of 79.5%). Three hundred sixty-eight males (35.6%) and six hundred sixty-six females (64.4%) participated in our study. The prevalence of burnout was 50.8% (525/1034) in this study population (mean score 2.74 ± 0.33). Logistic regression analysis showed that female gender [OR = 2.380, 95% CI: 1.731 to 2.554], first workplace [OR = 1.891, 95% CI: 1.582 to 2.162] and working more than 30 years [OR = 1.901, 95% CI: 1.608 to 2.326] have significantly increased the likelyhood of burnout as well as the history of muscoskeletal pain [OR = 1.156, 95% CI: 1.009 to1.342], current quality of life [OR = 1.602, 95% CI: 1.473 to 1.669] and the presence of sleep disturbance [OR = 1.289, 95% CI: 1.066 to 1.716]. Conclusion This is the first study in Hungary to investigate the prevalence of burnout among postal workers and to explore the relationship between burnout and mental health problems. Our study underlines the clinical importance of burnout and draws attention to the need for appropriate prevention and treatment strategies.

IntroductionThe extensive availability of the internet has led to the recognition of problematic usage of the internet (PUI) or so called internet addiction (IA), probably mostly involving adolescents.AimHere we present a study focusing on the incidence and consequences (including burnout, which is relatively rarely studied) of internet addiction among high school students using a questionnaire-based non-random sampling cross-sectional survey. Included questionnaires were the Problematic Internet Use Questionnaire, the Maslach Burnout Inventory General Survey for Students MBI-GS (S), the 9-item short version of Beck Depression Inventory (BDI-SF), the Athens Insomnia Questionnaire and the EQ-5D (quality of life) questionnaire. Data were evaluated the exertion of Student’s t-test, chi square test and Pearson’s rank-order correlation. Logistic regression analysis was used to determine the significance of the different parameters as independently associated with PUI.ResultsOverall 3,000 paper-based questionnaires were successfully delivered and 2,540 responses received (response rate of 84.6%). 1,309 males (mean age 17.6 ± 1.43 years) (51.5%) and 1,231 females (mean age 17.5 ± 1.4 years) (48.5%) took part in our study. Problematic usage of the internet was detected in 486 (19.1%) students (232 males, mean age 17.6 ± 1.35 years and 254 females, mean age 17.34 ± 1.37 years). In a logistic regression analysis sleep disturbance (OR: 1.84, 95% CI: 1.83–2.03), depression (OR: 1.97, 95% CI: 1.77–2.02) and burnout (OR: 1.8, 95% CI: 1.16–1.94) were significantly associated with PUI.ConclusionNearly one fifth of our study population suffered from PUI, which was strongly associated with school burnout, insomnia and depression, which underlines the importance of this phenomenon.

Introduction: The present study had two objectives: 1) to investigate the effects of tumble turns on the development of inspiratory muscle fatigue (IMF) and compare this to whole swimming, and 2) to evaluate the effects of pre-induced IMF on the kinematic parameters of tumble turns. Fourteen young club-level swimmers (13 ± 2 years of ages) completed three swim trials.Methods: The first trial was used to determine the 400-m front crawl swim time at maximal effort (400FC). The other two trials consisted of a series of 15 tumble turns at the 400FC pace. In one of the turn-only trials, IMF was pre-induced (TURNS-IMF), whereas in the other turn-only trial it was not (TURNS-C).Results: Compared with baseline values, the values for maximal inspiratory mouth pressure (PImax) at the end of the swim were significantly lower at all trials. However, the magnitude of inspiratory muscle fatigue was less after TURNS-C (PImax decreased by 12%) than after 400FC (PImax decreased by 28%). The tumble turns were slower during 400FC than during TURNS-C and TURNS-IMF. In addition, compared to TURNS-C, turns in the TURNS-IMF were performed with higher rotation times and shorter apnea and swim-out times.Discussion: The results of the present study suggest that tumble turns put a strain on the inspiratory muscles and directly contribute to the IMF observed during 400FC swimming. Furthermore, pre-induced IMF resulted in significantly shorter apneas and slower rotations during tumble turns. IMF therefore has the potential to negatively affect overall swimming performance, and strategies should be sought to reduce its effects.

Atypical chemokine receptor-1 (ACKR1), previously known as the Duffy antigen receptor for chemokines, is a widely conserved cell surface protein that is expressed on erythrocytes and the endothelium of post-capillary venules. In addition to being the receptor for the parasite causing malaria, ACKR1 has been postulated to regulate innate immunity by displaying and trafficking chemokines. Intriguingly, a common mutation in its promoter leads to loss of the erythrocyte protein but leaves endothelial expression unaffected. Study of endothelial ACKR1 has been limited by the rapid down-regulation of both transcript and protein when endothelial cells are extracted and cultured from tissue. Thus, to date the study of endothelial ACKR1 has been limited to heterologous over-expression models or the use of transgenic mice. Here we report that exposure to whole blood induces ACKR1 mRNA and protein expression in cultured primary human lung microvascular endothelial cells. We found that contact with neutrophils is required for this effect. We show that NF-κB regulates ACKR1 expression and that upon removal of blood, the protein is rapidly secreted by extracellular vesicles. Finally, we confirm that endogenous ACKR1 does not signal upon stimulation with IL-8 or CXCL1. Our observations define a simple method for inducing endogenous endothelial ACKR1 protein that will facilitate further functional studies.

This research is the first study on the influence of juicing methods on the ‘Aurora’ haskap juice quality. Three common juice extraction methods, namely, using a steam juicer, a centrifugal juicer, and a bladder wine press, were applied for haskap juice extraction. Both physicochemical assays and tests of antioxidant activities were employed to evaluate the qualities of the haskap juice. Generally, the centrifugal juicer increased and the steam juicer reduced concentrations of measured juice components relative to the press. The juice from the centrifugal juicer had the highest cloudiness. Sugar concentrations were about 40% lower in steam juice compared to the centrifugal juicer. Pressed juice had a slightly lower soluble solid content than the juice made with the centrifugal juicer and concentrations of glucose and fructose were similar between these methods. The methods altered pH and malic acid content without affecting the concentrations of tartaric and malic acids. Similar effects of juicing methods were seen in secondary compounds associated with health benefits and antioxidant capacities. Anthocyanin concentrations in press and centrifugal juicer extracts were similar, about 1.6 times higher than steam juicer extracts. Total phenolics and antioxidant activities were from two to four times higher in the centrifugal juicer extraction compared to steam juicing. Ascorbic acid and total flavonoid content in the haskap juice was increased by centrifugal juicing and decreased by steam juicing compared to the press. Overall, the juice extracted with the centrifugal juicer had concentrations of juice components that were 1.5–2 times higher than the steam juicer. The pressed juice had similar to slightly lower concentrations of components compared to the centrifugal juicer.

When verifying the validity of a formula in a system model by a model checker, a common feature is the generation of a linear witness or counterexample, which is a computation path usually showing a single reason why the formula is valid or, respectively, not. For systems represented with Labeled Transition Systems (LTS) and a subset of ACTLW (Action-based Computation Tree Logic with Unless operator) formulae, a procedure exists for the generation of witness automata, which contain all the interesting finite linear witnesses, thus revealing all the reasons of the validity of a formula. Although this procedure uses a symbolic representation of LTSs, transitions of a given LTS are traversed one by one. In this paper, we propose a procedure which exploits the symbolic representation efficiently to traverse several transitions at once. We evaluate the procedure on models of a communication protocol from industry and a biological system. The results show it to be at least several times faster than the former one. Witness automata were first introduced to allow for compositional generation of test sequences. We propose two more possible uses. One is for the detection of multiple errors in a model by exploring the witness automaton for a formula, instead of only one, which is usually the case with a single witness. The other one is for the detection of previously unknown system properties. As witness automata can be rather large, we show how some existing tools could help in examining them through visualization and simulation.

Introduction: Technological advances have made high-altitude ski slopes easily accessible to skiers of all ages. However, research on the effects of hypoxia experienced during excursions to such altitudes on physiological systems, including the ocular system, in children is scarce. Retinal vessels are embryologically of the same origin as vessels in the brain, and have similar anatomical and physiological characteristics. Thus, any hypoxia-related changes in the morphology of the former may reflect the status of the latter.Objective: To compare the effect of one-day hypoxic exposure, equivalent to the elevation of high-altitude ski resorts in North America and Europe (∼3,000 m), on retinal vessel diameter between adults and children.Methods: 11 adults (age: 40.1 ± 4.1 years) and 8 children (age: 9.3 ± 1.3 years) took part in the study. They spent 3 days at the Olympic Sports Centre Planica (Slovenia; altitude: 940 m). During days 1 and 2 they were exposed to normoxia (FiO2 = 0.209), and day 3 to normobaric hypoxia (FiO2 = 0.162 ± 0.03). Digital high-resolution retinal fundus photographs were obtained in normoxia (Day 2) and hypoxia (Day 3). Central retinal arteriolar equivalent (CRAE) and venular equivalents (CRVE) were determined using an Automated Retinal Image Analyser.Results: Central retinal arteriolar and venular equivalents increased with hypoxia in children (central retinal arteriolar equivalent: 105.32 ± 7.72 µm, hypoxia: 110.13 ± 7.16 µm, central retinal venular equivalent: normoxia: 123.39 ± 8.34 µm, hypoxia: 130.11 ± 8.54 µm) and adults (central retinal arteriolar equivalent: normoxia: 105.35 ± 10.67 µm, hypoxia: 110.77 ± 8.36 µm; central retinal venular equivalent: normoxia: 126.89 ± 7.24 µm, hypoxia: 132.03 ± 9.72 µm), with no main effect of group or group*condition interaction. A main effect of condition on central retinal arteriolar and venular equivalents was observed (central retinal arteriolar equivalent:normoxia: 105.34 ± 9.30 µm, hypoxia: 110.50 ± 7.67 µm, p < 0.001; central retinal venular equivalent: normoxia: 125.41 ± 7.70 µm, hypoxia: 131.22 ± 9.05 µm, p < 0.001).Conclusion: A 20-hour hypoxic exposure significantly increased central retinal arteriolar and venular equivalents in adults and children. These hypoxia-induced increases were not significantly different between the age groups, confirming that vasomotor sensitivity of the retinal vessels to acute hypoxia is comparable between adults and prepubertal children.

A new approach for improved RT-PCR is described. It is based on primers designed to form controlled stem–loop and homodimer configurations, hence the name ‘double-bubble’ primers. The primers contain three main regions for efficient RT-PCR: a 3′ short overhang to allow reverse transcription, a stem region for hot start and a template-specific region for PCR amplification. As proof of principle, GAPDH, SARS-CoV-2 synthetic RNA and SARS-CoV-2 virus-positive nasopharyngeal swabs were used as templates. Additionally, these primers were used to positively confirm the N501Y mutation from nasopharyngeal swabs. Evidence is presented that the double-bubble primers offer fast, specific, robust and cost-effective improvement in RT-PCR amplification for detection of gene expression in general and for diagnostic detection and genotyping of SARS-CoV-2 in particular.

Purpose of conference: New discoveries arising from investigations into fundamental aspects of kidney development and function in health and disease are critical to advancing kidney care. Scientific meetings focused specifically on fundamental biology of the kidney can facilitate interactions, support the development of collaborative groups, and accelerate translation of key findings. The Canadian fundamental kidney researcher community has lacked such a forum. On December 3 to 4, 2021, the first Molecules and Mechanisms Mediating Kidney Health and Disease (M3K) Scientific Meeting and Investigator Summit was held to address this gap with the goal of advancing fundamental kidney research nationally. The meeting was held virtually and was supported by a planning and dissemination grant from the Canadian Institutes of Health Research. Attendees included PhD scientists, nephrology clinician scientists, engineers, industry representatives, graduate students, medical residents, and fellows. Sources of information: This report was prepared from the scientific program, registration numbers, and details obtained from the online platform WHOVA, and summaries written by organizers and participants of the 2021 meeting. Methods: A 21-person team, consisting of the organizing committee members and participants from the meeting, was assembled. Key highlights of the meeting and future directions were identified and the team jointly assembled this report. Key findings: Participation in the meeting was strong, with more than 140 attendees across a range of disciplines. The program featured state-of-the-art presentations on diabetic nephropathy, the immune system, kidney development, and fibrosis, and was heavily focused on trainee presentations. The moderated “Investigator Summit” identified key barriers to research advancement and discussed strategies for overcoming them. These included establishment of a pan-Canadian fundamental kidney research network, development of key resources, cross-pollination with clinical nephrology, better reintegration into the Canadian Society of Nephrology, and further establishment of identity and knowledge translation. Limitations and implications: The 2021 M3K meeting represented a key first step in uniting fundamental kidney researchers in Canada. However, it was universally agreed that regular meetings were necessary to sustain this momentum. The proceedings of this meeting and future actions to sustain the M3K Scientific Meeting and Investigator Summit are presented in this article.

Abstract Background and Aims From 2019 till the present, infections induced by the novel coronavirus and its mutations have posed a new challenge for healthcare. However, comparative studies on pediatric infections throughout waves are few. During four different pandemic waves, we intended to investigate the clinical and epidemiological characteristic of the pediatric population hospitalized for severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) virus infection. Methods Between March 2020 and December 2021, we performed our retrospective research on children infected with the SARS‐CoV‐2 virus at the University of Szeged. We analyzed the data of all patients who required hospitalization due to positive results of SARS‐CoV‐2 tests (Nucleic Acid Amplification Test or rapid antigen test). Data analysis included demographic data, medical history, clinical findings, length of hospitalization, and complications, using medical records. Results In this study, data from 358 coronavirus‐infected children were analyzed. The most affected age group was children over 1 month and under 1 year (30.2%). The highest number of cases was recorded in the fourth wave (53.6%). Fever (65.6%), cough (51.4%), nasal discharge (35.3%), nausea and vomiting (31.3%), and decreased oral intake (28.9%) were the most common symptoms. The most common complications were dehydration (50.5%), pneumonia (14.9%), and bronchitis/bronchiolitis (14.5%). Based on RR values, there are considerable differences in the prevalence of the symptoms and complications between the different age groups and waves. Cox proportional hazard model analyzes showed that fever and tachypnoea had a relevant effect on days to recovery. Conclusions We found trends similar to those previously published, overall statistics. The proportion of children requiring hospitalization varied from wave to wave, with the fourth wave affecting the Hungarian child population the most. Our findings suggest that hospitalization time is unrelated to age, but that certain symptoms (fever and tachypnoea) are associated with longer hospitalization. The onset of certain symptoms may differ by age group.

Abstract Pulmonary oxygen uptake (V̇O2) kinetics have been well studied during land‐based exercise. However, less is known about V̇O2 kinetics during swimming exercise and comparisons between strokes is non‐existent. We aimed to characterize and compare the V̇O2 kinetics, ventilatory,e and metabolic response to constant velocity moderate‐intensity freely breathing front crawl (FC) and breaststroke (BR) swimming in a swimming flume. These two strokes reflect predominantly upper body versus lower body modes of swimming locomotion, respectively. Eight trained swimmers (4 females, 20 ± 1 years, 1.74 ± 0.06 m; 66.8 ± 6.3 kg) attended 5–6 laboratory‐based swimming sessions. The first two trials determined FC and BR V̇O2max and the ventilatory threshold (VT), respectively, during progressive intensity swimming to the limit of tolerance. Subsequent trials involved counterbalanced FC and BR transitions from prone floating to constant velocity moderate‐intensity swimming at 80% of the velocity at VT (vVT), separated by 30‐min recovery. Breath‐by‐breath changes in pulmonary gas exchange and ventilation were measured continuously using a snorkel and aquatic metabolic cart system. The ventilatory and metabolic responses were similar (p > 0.05) between strokes during maximal velocity swimming, however, vVT and maximal velocity were slower (p 0.05) between strokes. In conclusion, when breathing ad libitum, V̇O2 kinetics during moderate‐intensity constant velocity swimming, and ventilatory and metabolic responses during moderate‐intensity and maximal velocity swimming, are similar between FC and BR strokes.