Study on the relationship and related factors between physical fitness and health behavior of preschool children in southwest China.

OBJECTIVE: To investigate the physical fitness level and health behavior status of preschool children in China, explore the relationship between physical fitness and health behavior, and further reveal the main factors affecting health behavior, to provide a reference for improving the physical fitness level of preschool children and maintaining healthy behavior. METHODS: A total of 755 preschool children (394 boys and 361 girls, aged 4.52 ± 1.11 years) were selected from Chongqing and Liupanshui in China by cluster random sampling method for questionnaire survey and physical monitoring, and SPSS21.0 software was used to process and analyze the data. RESULTS: (1) Heart rate (p = 0.015), protein content (p < 0.001), and time spent on the balance beam (p < 0.001) were significantly lower in boys than in girls, while BMI (p = 0.012), muscle mass (p < 0.001), and distance of standing long jump (p < 0.001) were significantly higher in boys than in girls. Meanwhile, systolic blood pressure (p = 0.004) and diastolic blood pressure (p = 0.001) of rural children were significantly higher than those of urban children, while BMI (p < 0.001) and sitting forward flexion (p = 0.019) were significantly lower than those of urban children. (2) The light-intensity physical activity (LPA) and moderate to vigorous physical activity (MVPA) of boys were significantly higher than that of girls (p < 0.001), and the MVPA of urban children was significantly higher than that of rural children (p = 0.001), and the former participated in sports classes more frequently (p < 0.001). (3) There was a significant correlation between physical activity (PA) and physical fitness indicators of preschoolers. Participating in sports interest classes was only significantly correlated with systolic blood pressure (r = 0.08) and sitting forward flexion (r = 0.09). (4) The PA level of preschool children was related to gender, household registration, kindergarten nature, age, residence environment, parental support, and participation degree. Participation in sports interest classes was related to gender, the nature of the kindergarten, household registration, age, and parent participation. Daily screen time was related to household registration, the nature of the kindergarten, the environment of residence, and the value perception of parents. CONCLUSIONS: There were different degrees of correlation between preschool children's physical fitness and health behaviors, and children's health behaviors were closely related to gender, environment, parents, and other factors. Therefore, how to increase the protective factors of children's health behaviors and controlling the risk factors may be crucial to promoting the development of good health behaviors and improving the physical fitness of preschool children.

Visceral adiposity index, fitness and clustered cardiovascular disease risk in adolescents.

BACKGROUND:  Clustering of cardiovascular disease (CVD) risk factors have been observed in children and adolescents, but its association with visceral adiposity index (VAI) and cardiorespiratory fitness (CRF) in adolescents has rarely been studied. AIM:  This study determines the independent associations of VAI and CRF with the clustering of cardiovascular disease risk (CVDr) among Nigerian adolescents. SETTING:  Adolescents from specific secondary schools in Kogi East, North Central Nigeria participated in the study. METHODS:  A cross-sectional sample of 403 adolescents (202 boys and 201 girls) aged 11 years - 19 years were evaluated for VAI, CRF and CVDr. Using identified risk factors, a clustered CVDr score was generated. The association between VAI, CRF and clustered CVDr was evaluated using regression models that controlled for age, gender and maturity status. RESULTS:  Fitness was negatively associated with CVDr (ß = -0.268, p  0.001), while VAI was positively correlated with CVDr (ß = 0.379, p  0.001). After CRF or VAI adjustment, the independent association with the dependent variable remained significant. The odds of an adolescent with elevated VAI being at risk of CVD was 4.7 times higher than his peers. Unfit adolescents were 2.1 times more likely to develop CVDr. CONCLUSION:  Both VAI and CRF were independently associated with the clustering of CVDr in Nigerian adolescents. The findings suggest that health promotion efforts focusing on healthy diet and aerobic-type physical activity programmes should be encouraged among the youth to reduce the risk of CVD.Contribution: This study shows that improving visceral adipose tissue and fitness may lower CVD risk factors in adolescents, which is significant for public health.

Co-infection dynamics of B. afzelii and TBEV in C3H mice: insights and implications for future research.

Ticks are important vectors of disease, particularly in the context of One Health, where tick-borne diseases (TBDs) are increasingly prevalent worldwide. TBDs often involve co-infections, where multiple pathogens co-exist in a single host. Patients with chronic Lyme disease often have co-infections with other bacteria or parasites. This study aimed to create a co-infection model with Borrelia afzelii and tick-borne encephalitis virus (TBEV) in C3H mice and to evaluate symptoms, mortality, and pathogen level compared to single infections. Successful co-infection of C3H mice with B. afzelii and TBEV was achieved. Outcomes varied, depending on the timing of infection. When TBEV infection followed B. afzelii infection by 9 days, TBEV symptoms worsened and virus levels increased. Conversely, mice infected 21 days apart with TBEV showed milder symptoms and lower mortality. Simultaneous infection resulted in mild symptoms and no deaths. However, our model did not effectively infect ticks with TBEV, possibly due to suboptimal dosing, highlighting the challenges of replicating natural conditions. Understanding the consequences of co-infection is crucial, given the increasing prevalence of TBD. Co-infected individuals may experience exacerbated symptoms, highlighting the need for a comprehensive understanding through refined animal models. This study advances knowledge of TBD and highlights the importance of exploring co-infection dynamics in host-pathogen interactions.

Why do generation X customers use wearable fitness technology equipment after recovering from coronavirus? The role of perceived health risks.

The health sector has prioritized the physical health of vulnerable Generation X individuals at high Coronavirus risk. Despite vaccination efforts, both infected and healthy people continue facing health threats. Unlike other industries devastated by COVID-19, wearable fitness technology equipment (WFTE) is essential for health-focused individuals. This research examined customers' intention to use WFTE using an adapted Technology Acceptance Model (TAM) framework. A key contribution is the inclusion of perceived health risk and its impact on WFTE value perceptions and usage attitudes post-pandemic. The study gathered qualitative data from coronavirus patients and survey data from 513 participants. Structural equation modeling analysis supported the theoretical model. While the standard TAM evaluated intent to use WFTE, this study uniquely examined how WFTE's functional, hedonic, and symbolic value shapes its perceived value. Perceived health risk was found to significantly impact perceived WFTE value and usage attitudes after the pandemic recovery. Findings offer managerial implications to boost WFTE adoption among the vulnerable Generation X demographic.

Fitness costs of Tn1546-type transposons harboring the vanA operon by plasmid type and structural diversity in Enterococcus faecium.

BACKGROUND: This study analyzed the genetic traits and fitness costs of vancomycin-resistant Enterococcus faecium (VREfm) blood isolates carrying Tn1546-type transposons harboring the vanA operon. METHODS: All E. faecium blood isolates were collected from eight general hospitals in South Korea during one-year study period. Antimicrobial susceptibility testing and vanA and vanB PCR were performed. Growth rates of E. faecium isolates were determined. The vanA-positive isolates were subjected to whole genome sequencing and conjugation experiments. RESULTS: Among 308 E. faecium isolates, 132 (42.9%) were positive for vanA. All Tn1546-type transposons harboring the vanA operon located on the plasmids, but on the chromosome in seven isolates. The plasmids harboring the vanA operon were grouped into four types; two types of circular, nonconjugative plasmids (Type A, n = 50; Type B, n = 46), and two types of putative linear, conjugative plasmids (Type C, n = 16; Type D, n = 5). Growth rates of vanA-positive E. faecium isolates were significantly lower than those of vanA-negative isolates (P < 0.001), and reduction in growth rate under vancomycin pressure was significantly larger in isolates harboring putative linear plasmids than in those harboring circular plasmids (P = 0.020). CONCLUSIONS: The possession of vanA operon was costly to bacterial hosts in antimicrobial-free environment, which provide evidence for the importance of reducing vancomycin pressure for prevention of VREfm dissemination. Fitness burden to bacterial hosts was varied by type and size of the vanA operon-harboring plasmid.

Adult telomere length is positively correlated with survival and lifetime reproductive success in a wild passerine.

Explaining variation in individual fitness is a key goal in evolutionary biology. Recently, telomeres, repeating DNA sequences capping chromosome ends, have gained attention as a biomarker for body state, physiological costs, and senescence. Existing research has provided mixed evidence for whether telomere length correlates with fitness, including survival and reproductive output. Moreover, few studies have examined how the rate of change in telomere length correlates with fitness in wild populations. Here, we intensively monitored an insular population of house sparrows, and collected longitudinal telomere and life history data (16 years, 1225 individuals). We tested whether telomere length and its rate of change predict fitness measures, namely survival, lifespan and annual and lifetime reproductive effort and success. Telomere length positively predicted short-term survival, independent of age, but did not predict lifespan, suggesting either a diminishing telomere length-survival correlation with age or other extrinsic factors of mortality. The positive association of telomere length with survival translated into reproductive benefits, as birds with longer telomeres produced more genetic recruits, hatchlings and reared more fledglings over their lifetime. In contrast, there was no association between telomere dynamics and annual reproductive output, suggesting telomere dynamics might not reflect the costs of reproduction in this population, potentially masked by variation in individual quality. The rate of change of telomere length did not correlate with neither lifespan nor lifetime reproductive success. Our results provide further evidence that telomere length correlates with fitness, and contribute to our understanding of the selection on, and evolution of, telomere dynamics.

Design principles of multi-map variation in biological systems.

Complexity in biology is often described using a multi-map hierarchical architecture, where the genotype, representing the encoded information, is mapped to the functional level, known as the phenotype, which is then connected to a latent phenotype we refer to as fitness. This underlying architecture governs the processes driving evolution. Furthermore, natural selection, along with other neutral forces, can, in turn, modify these maps. At each level, variation is observed. Here, I propose the need to establish principles that can aid in understanding the transformation of variation within this multi-map architecture. Specifically, I will introduce three, related to the presence of modulators, constraints, and the modular channeling of variation. By comprehending these design principles in various biological systems, we can gain better insights into the mechanisms underlying these maps and how they ultimately contribute to evolutionary dynamics.

Estimating cardiorespiratory fitness in older adults using the international physical activity questionnaire.

Introduction: Non-exercise estimates of cardiorespiratory fitness hold great utility for epidemiological research and clinical practice. Older adults may yield the greatest benefit from fitness estimates due to limited capacity to undergo strenuous maximal exercise testing, however, few of the previously developed non-exercise equations are suitable for use in older adults. Thus, the current study developed a non-exercise equation for estimating cardiorespiratory fitness in older adults derived from the widely used International Physical Activity Questionnaire (IPAQ). Methods: This study was a secondary analysis of baseline data from a randomized controlled trial. Participants were community-dwelling, cognitively unimpaired older adults aged 60-80 years (n = 92). They completed the IPAQ and underwent maximal exercise testing on a cycle ergometer. Stepwise linear regression was used to determine the equation in a randomly selected, sex-balanced, derivation subset of participants (n = 60), and subsequently validated using a second subset of participants (n = 32). Results: The final equation included age, sex, body mass index and leisure time activity from the IPAQ and explained 61% and 55% of the variance in the derivation and validation groups, respectively (standard error of estimates = 3.9, 4.0). Seventy-seven and 81% of the sample fell within ±1SD (5.96 and 6.28 ml·kg-1·min-1) of measured VO2peak for the derivation and validation subgroups. The current equation showed better performance compared to equations from Wier et al. (2006), Jackson et al. (1990), and Schembre & Riebe (2011), although it is acknowledged previous equations were developed for different populations. Conclusions: Using non-exercise, easily accessible measures can yield acceptable estimates of cardiorespiratory fitness in older adults, which should be further validated in other samples and examined in relation to public health outcomes.

Combined Exercise and Mindset Training During a Pediatric Cardiac Fitness and Rehabilitation Program Benefits Youth with a Range of Congenital Heart Disease.

Pediatric cardiac fitness and rehabilitation programs vary widely in structure and content. The Cardiac Fitness Program (CFP) is built on traditional training pillars of aerobic, strength, and flexibility, and adds a fourth, training a positive mindset. This study assesses whether the systematic and comprehensive framework of the CFP results in broad benefits for a range of patients with congenital heart disease (CHD). Data from participants between 01/2017 and 12/2022 were analyzed. Pre- and post-CFP cardiopulmonary exercise test parameters, strength and flexibility metrics, and mindset survey results were compared overall, and by sex, age, diagnosis, and hemodynamic level. Of 62 participants (median age 15.5 years, range 8 to 23, 50% female), 3% had simple, 37% complex, 24% single ventricle CHD, and 35% arrhythmia, cardiomyopathy, or transplant. Significant improvements were noted in aerobic fitness (mean 9 ± 15% increase in % predicted peak oxygen consumption, p < 0.001). Strength metrics significantly improved (each p < 0.001), as did flexibility (p < 0.001). Patient-reported positive mindset scores did not improve significantly (mean increase 1.8 ± 5.1, p = 0.10, n = 25), whereas parents reported significant improvements (5.9 ± 10.4, p = 0.02, n = 20). Improvements were not significantly different by sex, age, diagnosis, or hemodynamic level. Comprehensive training across four pillars of fitness yields significant improvements in aerobic fitness, strength, flexibility, and parent-reported mindset scores for pediatric CHD patients, regardless of patient characteristics, diagnosis type, or severity of hemodynamic limitation. Further study is warranted into optimal standardization of training and whether a comprehensive approach amplifies individual pillars to create more than the sum of its parts.

Examining body mass index and health-related fitness marker progression of incarcerated minority youth engaged in a sport-leadership program.

PURPOSE: The purpose of this study was to examine the impact of a sport-leadership program on minority incarcerated young adults' health-related fitness markers. DESIGN/METHODOLOGY/APPROACH: This study occurred at an all-male juvenile detention center. A total of 41 participants in this study were obtained from a sample of 103 incarcerated young adults. Data collection entailed body mass index (BMI) evaluation, cardiovascular endurance tests and 1-min pushups and situps at two different time periods (before and after three months). A 2 × 2 mixed factorial analysis of variances was used to test for differences among the within subjects' factors (time [pre × post]) and between subjects' factors (groups [flex × control]) for the above-mentioned dependent variables. FINDINGS: Over the course of three consecutive months of engagement, preliminary indications demonstrated participants had a slight reduction in BMI and significant increases in cardiovascular endurance and muscle strength. Contrarily, during this same time period, non-participating young adults exhibited significant increases in BMI and decreases in cardiovascular endurance and muscle strength. ORIGINALITY/VALUE: Integration of sport-leadership programs is generally not free but can be a low-cost alternative for combatting many issues surrounding physical activity, weight gain and recreational time for those incarcerated.

Field-evolved resistance to nitenpyram is associated with fitness costs in whitefly.

BACKGROUND: Elucidating fitness cost associated with field-evolved insect resistance to insecticide is of particular importance to current sustainable pest control. The global pest whitefly Bemisia tabaci has developed resistance to many members of neonicotinoids, but little is known about whitefly resistance to neonicotinoid nitenpyram and its associated fitness cost. Using insecticide bioassay and life-table approach, this study aims to investigate nitenpyram resistance status in field-collected whitefly populations, and to explore whether such resistance is accompanied by a fitness cost. RESULTS: The bioassay results revealed that 14 of 29 whitefly populations displayed moderate to extremely high resistance to nitenpyram, demonstrating a widespread field-evolved resistance to nitenpyram. This field-evolved resistance in the whitefly has increased gradually over the past 3 years from 2021 to 2023. Further life-table study showed that two resistant whitefly populations exhibited longer developmental time, shorter lifespans of adult, and lower fecundity compared with the most susceptible population. The relative fitness cost of the two resistant populations was calculated as 0.69 and 0.56 by using net productive rate R0, which suggests that nitenpyram resistance comes with fitness cost in the whitefly, especially on reproduction. CONCLUSION: Overall, these results represent field-evolved high resistance to nitenpyram in the whitefly. The existing fitness costs associated with nitenpyram resistance are helpful to propose a suitable strategy for sustainable control of whiteflies by rotation or mixture of insecticide with different modes of action. © 2024 Society of Chemical Industry.

Predicting the Combined Effects of Multiple Stressors and Stress Adaptation in Gammarus pulex.

Global change confronts organisms with multiple stressors causing nonadditive effects. Persistent stress, however, leads to adaptation and related trade-offs. The question arises: How can the resulting effects of these contradictory processes be predicted? Here we show that Gammarus pulex from agricultural streams were more tolerant to clothianidin (mean EC50 148 µg/L) than populations from reference streams (mean EC50 67 µg/L). We assume that this increased tolerance results from a combination of physiological acclimation, epigenetic effects, and genetic evolution, termed as adaptation. Further, joint exposure to pesticide mixture and temperature stress led to synergistic interactions of all three stressors. However, these combined effects were significantly stronger in adapted populations as shown by the model deviation ratio (MDR) of 4, compared to reference populations (MDR = 2.7). The pesticide adaptation reduced the General-Stress capacity of adapted individuals, and the related trade-off process increased vulnerability to combined stress. Overall, synergistic interactions were stronger with increasing total stress and could be well predicted by the stress addition model (SAM). In contrast, traditional models such as concentration addition (CA) and effect addition (EA) substantially underestimated the combined effects. We conclude that several, even very disparate stress factors, including population adaptations to stress, can act synergistically. The strong synergistic potential underscores the critical importance of correctly predicting multiple stresses for risk assessment.

Lipid Metabolism in Parasitoids and Parasitized Hosts.

Parasitoids have an exceptional lifestyle where juvenile development is spent on or in a single host insect, but the adults are free-living. Unlike parasites, parasitoids kill the host. How parasitoids use such a limiting resource, particularly lipids, can affect chances to survive and reproduce. In part 1, we describe the parasitoid lifestyle, including typical developmental strategies. Lipid metabolism in parasitoids has been of interest to researchers since the 1960s and continues to fascinate ecologists, evolutionists, physiologists, and entomologists alike. One reason of this interest is that the majority of parasitoids do not accumulate triacylglycerols as adults. Early research revealed that some parasitoid larvae mimic the fatty acid composition of the host, which may result from a lack of de novo triacylglycerol synthesis. More recent work has focused on the evolution of lack of adult triacylglycerol accumulation and consequences for life history traits. In part 2 of this chapter, we discuss research efforts on lipid metabolism in parasitoids from the 1960s onwards. Parasitoids are also master manipulators of host physiology, including lipid metabolism, having evolved a range of mechanisms to affect the release, synthesis, transport, and take-up of lipids from the host. We lay out the effects of parasitism on host physiology in part 3 of this chapter.

Multigenerational inheritance drives symbiotic interactions of the bacterium Bacillus subtilis with its plant host.

Bacillus subtilis is a beneficial bacterium that supports plant growth and protects plants from bacterial, fungal, and viral infections. Using a simplified system of B. subtilis and Arabidopsis thaliana interactions, we studied the fitness and transcriptome of bacteria detached from the root over generations of growth in LB medium. We found that bacteria previously associated with the root or exposed to its secretions had greater stress tolerance and were more competitive in root colonization than bacteria not previously exposed to the root. Furthermore, our transcriptome results provide evidence that plant secretions induce a microbial stress response and fundamentally alter signaling by the cyclic nucleotide c-di-AMP, a signature maintained by their descendants. The changes in cellular physiology due to exposure to plant exudates were multigenerational, as they allowed not only the bacterial cells that colonized a new plant but also their descendants to have an advance over naive competitors of the same species, while the overall plasticity of gene expression and rapid adaptation were maintained. These changes were hereditary but not permanent. Our work demonstrates a bacterial memory manifested by multigenerational reversible adaptation to plant hosts in the form of activation of the stressosome, which confers an advantage to symbiotic bacteria during competition.

Study on the relationship between body mass index and blood pressure indices in children aged 7-17 during COVID-19.

Background: To explore the relationship between body mass index (BMI), age, sex, and blood pressure (systolic blood pressure, SBP; diastolic blood pressure, DBP) in children during COVID-19, providing reference for the prevention and screening of hypertension in children. Methods: This study adopted a large-scale cross-sectional design to investigate the association between BMI and blood pressure in 7-17-year-old students in City N, China, during COVID-19. Thirty-six primary and secondary schools in City N were sampled using a stratified cluster sampling method. A total of 11,433 students aged 7-17 years in City N, China, were selected for blood pressure (Diastolic blood pressure, DBP, Systolic blood pressure, SBP), height, and weight, Resting heart rate (RHR), chest circumference, measurements, and the study was written using the STROBE checklist. Data analysis was conducted using SPSS 26.0, calculating the mean and standard deviation of BMI and blood pressure for male and female students in different age groups. Regression analysis was employed to explore the impact of BMI, age, and sex on SBP and DBP, and predictive models were established. The model fit was evaluated using the model R2. Results: The study included 11,287 primary and secondary school students, comprising 5,649 boys and 5,638 girls. It was found that with increasing age, BMI and blood pressure of boys and girls generally increased. There were significant differences in blood pressure levels between boys and girls in different age groups. In regression models, LC, Age, BMI, and chest circumference show significant positive linear relationships with SBP and DBP in adolescents, while RHR exhibits a negative linear relationship with SBP. These factors were individually incorporated into a stratified regression model, significantly enhancing the model's explanatory power. After including factors such as Age, Gender, and BMI, the adjusted R2 value showed a significant improvement, with Age and BMI identified as key predictive factors for SBP and DBP. The robustness and predictive accuracy of the model were further examined through K-fold cross-validation and independent sample validation methods. The validation results indicate that the model has a high accuracy and explanatory power in predicting blood pressure in children of different weight levels, especially among obese children, where the prediction accuracy is highest. Conclusion: During COVID-19, age, sex, and BMI significantly influence blood pressure in children aged 7-17 years, and predictive models for SBP and DBP were established. This model helps predict blood pressure in children and reduce the risk of cardiovascular diseases. Confirmation of factors such as sex, age, and BMI provide a basis for personalized health plans for children, especially during large-scale infectious diseases, providing guidance for addressing health challenges and promoting the health and well-being of children.

Assessment of cardiorespiratory fitness in Chinese patients with early to mid-stage Parkinson's disease.

Introduction In recent years, exercise has been increasingly recognised as an effective and promising non-pharmacological intervention to improve physical function in patients with Parkinson's disease (PD). Cardiorespiratory fitness (CRF) is an objective measure of a person's ability to perform aerobic exercise. Therefore, it is necessary to evaluate the CRF of patients with PD.However, the CRF of Chinese patients with PD is deficient.This study is to evaluate cardiorespiratory fitness in patients with early to mid-stage PD by cardiopulmonary exercise test(CPET) on a stationary cycle ergometer; Methods:To compare the differences in each index of the CPET between the two groups of subjects; general data such as disease duration, medication use and exercise habits were also collected.Results:1)Finally, 36 PD patients and 12 healthy controls successfully completed the CPET without any adverse events.2)The V'O2peak, Metspeak, RERpeak, MVVpeak, Wpeak, HRpeak, HRpeak/pre,percentage of HRR-1 min decay > 12 bpm,SBPpeak in the PD group were lower than those in the control group(p < 0.05,each). Detailed data:V'O2peak(15.7 ± 4.5vs21.5 ± 3.6ml/kg/min,p < 0.01),Metspeak(4.5 ± 1.3 vs 6.1 ± 1.0,p < 0.01),RERpeak(1.04 ± 0.10 vs 1.15 ± 0.10,p = 0.001),MVVpeak(37.22 ± 11.58 vs 53.00 ± 16.85L/min,p = 0.009),Wpeak(49.17 ± 29.72vs49.17 ± 29.72W,p < 0.01),HRpeak(111.08 ± 16.67 vs111.08 ± 16.67bpm,p < 0.01),HRpeak/pre(71.19 ± 10.06 vs96.00 ± 21.13,p = 0.002),percentage of HRR-1min decay > 12bpm(33.3% vs 100%,p < 0.01),SBP(155.81 ± 31.83 vs 175.83 ± 17.84mmHg,p = 0.01).3)Divided PD patients into high V'O2peak group(V'O2peak ≥ 15 mL/kg/min) and low V'O2peak group(V'O2peak < 15 mL/kg/min). The age of patients, Hoehn-Yahr grade and incidence of symptom fluctuation in high V'O2peak group were lower(p < 0.05,respectively),percentage of males and percentage of HRR-1 min decay > 12 bpm were higher(p < 0.05,respectively);p < 0.05 is considered a statistically significant difference.Detailed data:age of patients(61.05 ± 6.93vs68.57 ± 7.99years,p = 0.005),Hoehn-Yahr grade(1.75 ± 0.48 vs 2.18 ± 0.64,p = 0.028),incidence of symptom fluctuation(59.1 vs 92.9%,p = 0.03),percentage of males(77.7 vs 42.9%,p = 0.041),percentage of HRR-1 min decay > 12 bpm(50 vs 7.1%,p = 0.008). Conclusions:CPET were safe to perform and the cardiorespiratory fitness is significantly reduced in patients with early and middle stage Parkinson's disease.Patients with PD presented blunted HR and SBP responses to exercise test. Females, older age, fluctuating symptoms, high H-Y staging, and higher ADL may be associated with lower oxygen uptake.

Cardiopulmonary exercise variables and their association with postoperative morbidity and mortality after major oesophagogastric cancer surgery-a multicentre observational study.

Background: Outcomes after oesophagogastric cancer surgery remain poor. Cardiopulmonary exercise testing (CPET) used for risk stratification before oesophagogastric cancer surgery is based on conflicting evidence. This study explores the relationship between CPET and postoperative outcomes, specifically for patients undergoing neoadjuvant treatment. Methods: Patients undergoing oesophagogastric cancer resection and CPET (pre- or post-neoadjuvant treatment, or both) were retrospectively enrolled into a multicentre pooled cohort study. Oxygen uptake at peak exercise (VO2 peak) was compared with 1-yr postoperative survival. Secondary analyses explored relationships between patient characteristics, tumour pathology characteristics, CPET variables (absolute, relative to weight, ideal body weight, and body surface area), and postoperative outcomes (morbidity, 1-yr and 3-yr survival) were assessed using logistic regression analyses. Results: Seven UK centres recruited 611 patients completing a 3-yr postoperative follow-up period. Oesophagectomy was undertaken in 475 patients (78%). Major complications occurred in 25%, with 18% 1-yr and 43% 3-yr mortality. No association between VO2 peak or other selected CPET variables and 1-yr survival was observed in the overall cohort. In the overall cohort, the anaerobic threshold relative to ideal body weight was associated with 3-yr survival (P=0.013). Tumour characteristics (ypT/ypN/tumour regression/lymphovascular invasion/resection margin; P<0.001) and Clavien-Dindo ≥3a (P<0.001) were associated with 1-yr and 3-yr survival. On subgroup analyses, pre-neoadjuvant treatment CPET; anaerobic threshold (absolute; P=0.024, relative to ideal body weight; P=0.001, body surface area; P=0.009) and VE/VCO2 at anaerobic threshold (P=0.026) were associated with 3-yr survival. No other CPET variables (pre- or post-neoadjuvant treatment) were associated with survival. Conclusions: VO2 peak was not associated with 1-yr survival after oesophagogastric cancer resection. Tumour characteristics and major complications were associated with survival; however, only some selected pre-neoadjuvant treatment CPET variables were associated with 3-yr survival. CPET in this cohort of patients demonstrates limited outcome predictive precision. Clinical trial registration: NCT03637647.

Host defense alteration in Caenorhabditis elegans after evolution under ionizing radiation.

BACKGROUND: Adaptation to a stressor can lead to costs on other traits. These costs play an unavoidable role on fitness and influence the evolutionary trajectory of a population. Host defense seems highly subject to these costs, possibly because its maintenance is energetically costly but essential to the survival. When assessing the ecological risk related to pollution, it is therefore relevant to consider these costs to evaluate the evolutionary consequences of stressors on populations. However, to the best of our knowledge, the effects of evolution in irradiate environment on host defense have never been studied. Using an experimental evolution approach, we analyzed fitness across 20 transfers (about 20 generations) in Caenorhabditis elegans populations exposed to 0, 1.4, and 50.0 mGy.h- 1 of 137Cs gamma radiation. Then, populations from transfer 17 were placed in the same environmental conditions without irradiation (i.e., common garden) for about 10 generations before being exposed to the bacterial parasite Serratia marcescens and their survival was estimated to study host defense. Finally, we studied the presence of an evolutionary trade-off between fitness of irradiated populations and host defense. RESULTS: We found a lower fitness in both irradiated treatments compared to the control ones, but fitness increased over time in the 50.0 mGy.h- 1, suggesting a local adaptation of the populations. Then, the survival rate of C. elegans to S. marcescens was lower for common garden populations that had previously evolved under both irradiation treatments, indicating that evolution in gamma-irradiated environment had a cost on host defense of C. elegans. Furthermore, we showed a trade-off between standardized fitness at the end of the multigenerational experiment and survival of C. elegans to S. marcescens in the control treatment, but a positive correlation between the two traits for the two irradiated treatments. These results indicate that among irradiated populations, those most sensitive to ionizing radiation are also the most susceptible to the pathogen. On the other hand, other irradiated populations appear to have evolved cross-resistance to both stress factors. CONCLUSIONS: Our study shows that adaptation to an environmental stressor can be associated with an evolutionary cost when a new stressor appears, even several generations after the end of the first stressor. Among irradiated populations, we observed an evolution of resistance to ionizing radiation, which also appeared to provide an advantage against the pathogen. On the other hand, some of the irradiated populations seemed to accumulate sensitivities to stressors. This work provides a new argument to show the importance of considering evolutionary changes in ecotoxicology and for ecological risk assessment.

Evolutionary biology of social expertise.

There is increasing evidence that competent handling of social interactions among conspecifics has positive effects on individual fitness. While individual variation in social competence has been appreciated, the role of long-term experience in the acquisition of superior social skills has received less attention. With the goal of promoting further research, we integrate knowledge across disciplines to assess social expertise, defined as the characteristics, skills and knowledge allowing individuals with extensive social experience to perform significantly better than novices on a given social task. We focus on three categories of social behaviour. First, animals can gain from adjusting social behaviour towards individually recognised conspecifics that they interact with on a regular basis. For example, there is evidence that some territorial animals individually recognise their neighbours and modify their social interactions based on experience with each neighbour. Similarly, individuals in group-living species learn to associate with specific group members based on their expected benefits from such social connections. Individuals have also been found to devote considerable time and effort to learning about the spatial location and timing of sexual receptivity of opposite-sex neighbours to optimise reproduction. Second, signallers can enhance their signals, and receivers can refine their response to signals with experience. In many birds and insects, individuals can produce more consistent signals with experience, and females across a wide taxonomic range can adaptively adjust mating preferences after perceiving distinct male signals. Third, in many species, individuals that succeed in reproducing encounter the novel, complex task of caring for vulnerable offspring. Evidence from a few species of mammals indicates that mothers improve in providing for and protecting their young over successive broods. Finally, for social expertise to evolve, heritable variation in social expertise has to be positively associated with fitness. Heritable variation has been shown in traits contributing to social expertise including social attention, empathy, individual recognition and maternal care. There are currently limited data associating social expertise with fitness, most likely owing to sparse research effort. Exceptions include maternal care, signal refinement, and familiarity with neighbours and group members. Overall, there is evidence that individuals in many species keep refining their social skills with experience throughout life. Hence we propose promising lines of research that can quantify more thoroughly the development of social expertise and its effects on fitness.