Fitness Consequences Research Articles

No effect of aerobic fitness on exercise-induced diaphragm fatigue in females.

We tested the hypothesis that the incidence and magnitude of diaphragm fatigue following high-intensity exercise would be lower in females with a high aerobic capacity (Hi-Fit) compared with healthy females with an average aerobic fitness (Avg-Fit). Participants were assigned to groups based on their peak O2 uptake (V̇o2peak) obtained during cycle exercise: Hi-Fit n = 9, V̇o2peak ≥ 56.1 ± 3.4 mL·kg-1·min-1 versus Avg-Fit n = 9, V̇o2peak ≤ 35.7 ± 4.9 mL·kg-1·min-1. On the second day, diaphragm fatigue was assessed before and after constant load exercise test to exhaustion. Magnetic stimulation of the phrenic nerve roots was used to nonvolitionally assess diaphragm fatigue by measurement of transdiaphragmatic twitch pressure (Pdi,tw). Both groups exercised at >90% of V̇o2peak for a similar duration (Hi-Fit: 546.1 ± 177.8 vs. Avg-Fit: 559.3 ± 175.0 s, P = 0.9). Diaphragm fatigue was defined as a ≥15% reduction in Pdi,tw, approximately two times greater than the coefficient of variation. The mean group average reduction in Pdi,tw following exercise in the Hi-Fit (17.5%) and Avg-Fit groups (12.2%) was not different between groups (P = 0.2). The Hi-Fit group performed exercise at a higher absolute work rate that elicited significantly greater ventilatory work and inspiratory muscle force output. The Hi-Fit group did not experience greater fatigue compared with the Avg-Fit group, which we attribute to a greater reliance on accessory respiratory muscle recruitment, to training-induced increases in the aerobic capacity of the diaphragm, or a combination of the two. In summary, aerobic fitness is not predictive of exercise-induced diaphragm fatigue in healthy females.NEW & NOTEWORTHY We hypothesized that females with a high aerobic capacity would be resistant to exercise-induced diaphragm fatigue relative to healthy but untrained females. We assessed the pressure generated by the diaphragm following exhaustive exercise by stimulating the phrenic nerves. The magnitude and incidence of fatigue were similar between groups. Despite having higher ventilatory demands during exercise highly trained females were resistant to greater diaphragm fatigue. Aerobic fitness is not predictive of exercise-induced diaphragm fatigue in females.

Reconciling theories of dominance with the relative rates of adaptive substitution on sex chromosomes and autosomes.

The dominance of beneficial mutations is a key evolutionary parameter affecting the rate and genetic basis of adaptation, yet it is notoriously difficult to estimate. A leading method to infer it is to compare the relative rates of adaptive substitution for X-linked and autosomal genes, which-according to a classic model by Charlesworth et al. (1987)-is a simple function of the dominance of new beneficial mutations. Recent evidence that rates of adaptive substitution are faster for X-linked genes implies, accordingly, that beneficial mutations are usually recessive. However, this conclusion is incompatible with leading theories of dominance, which predict that beneficial mutations tend to be dominant or overdominant with respect to fitness. To address this incompatibility, we use Fisher's geometric model to predict the distribution of fitness effects of new mutations and the relative rates of positively selected substitution on the X and autosomes. Previous predictions of faster-X theory emerge as a special case of our model in which the phenotypic effects of mutations are small relative to the distance to the phenotypic optimum. But as mutational effects become large relative to the optimum, we observe an elevated tempo of positively selected substitutions on the X relative to the autosomes across a broader range of dominance conditions, including those predicted by theories of dominance. Our results imply that, contrary to previous models, dominant and overdominant beneficial mutations can plausibly generate patterns of faster-X adaptation. We discuss resulting implications for genomic studies of adaptation and inferences of dominance.

Cut-off values for estimated cardiorespiratory fitness in terms of physical functioning among middle-aged to older adults.

Cardiorespiratory fitness is linked to various health outcomes. This study aimed to establish cut-off values for estimated cardiorespiratory fitness associated with poor physical functioning in middle-aged to older adults. A total of 2638 participants (1083 males), aged 40-69 years, performed a 6-min walking test (6MWT) to estimate cardiorespiratory fitness (VO<inf>2max)</inf> and completed a health-related questionnaire. Physical functioning was assessed using four outcomes: perceived health, perceived fitness, difficulties in 2-km walking, and difficulties in climbing several stairs. Receiver operator characteristics (ROC) curves were used to determine cut-off values for estimated VO<inf>2max</inf> and 6MWT distance linked to poor physical functioning based on the four outcomes. Analyses were done separately for males and females, and for 40- to 49-, 50- to 59-, and 60- to 69-year-old groups. Multinomial regression was used to analyze differences between fitness thirds in outcome variables. ROC analyses were significant for all outcomes (AUC 0.686-0.834, P<0.001). In the total group, cut-off values for estimated VO<inf>2max</inf> were 29.9-30.2 mL/kg/min, and for walking distance, 588.0-599.5 m. Cut-off values decreased with age, and mean differences between males and females were 3.3 mL/kg/min and 33 m. All cut-off values were within ±1.3 mL/kg/min of the lower fitness tertile. The odds ratios of having poor physical functioning in the middle and high fitness thirds were less than 0.50 compared to low fitness third. VO<inf>2max</inf> of 30 mL/kg/min and 600-m walking distance seemed reasonable cut-off values for poor physical functioning. Exceeding the currently proposed thresholds is a desirable goal to avoid consequences of insufficient fitness.

Associations Between Gut Microbiota Diversity and a Host Fitness Proxy in a Naturalistic Experiment Using Threespine Stickleback Fish.

The vertebrate gut microbiota is a critical determinant of organismal function, yet whether and how gut microbial communities affect host fitness under natural conditions remains largely unclear. We characterised associations between a fitness proxy-individual growth rate-and bacterial gut microbiota diversity and composition in threespine stickleback fish introduced to large semi-natural ponds. We detected a 63% higher richness of bacterial taxa (α-diversity) in the guts of high-fitness fish compared to low-fitness fish, which might be driven by stronger bacterial dispersal among high-fitness fish according to the fit of a neutral community model. Further, microbial communities of high-fitness fish were more similar to one another (i.e., exhibited lower β-diversity) than those of low-fitness fish. The lower β-diversity found to be associated with higher host fitness is consistent with the Anna Karenina principle-that there are fewer ways to have a functional microbiota than a dysfunctional microbiota. Our study links differences in α- and β-diversity to a fitness-related trait in a vertebrate species reared under naturalistic conditions and our findings provide a basis for functional tests of the fitness consequences of host-microbiota interactions.

Further evidence for strong non-neutrality of yeast synonymous mutations.

Although synonymous mutations are commonly assumed neutral or nearly so, recent years have seen reports of fitness effects of synonymous mutations detected under laboratory conditions. In a previous study, we used genome editing to construct thousands of yeast mutants each carrying a synonymous or nonsynonymous mutation in one of 21 genes and discovered that most synonymous and most nonsynonymous mutations are deleterious. A concern was raised that this observation could be caused by the fitness effects of potential CRISPR/Cas9 off-target edits and/or secondary mutations, and an experiment that would be refractory to such effects was proposed. Using genome sequencing, we here show that no CRISPR/Cas9 off-target editing occurred, although some mutants did carry secondary mutations. Analysis of mutants with negligible effects from secondary mutations and new data collected from the proposed experiment confirms the original conclusion. These findings, along with other reports of fitness effects of synonymous mutations from both case and systematic studies, necessitate a paradigm shift from assuming (near) neutrality of synonymous mutations.

Spatiotemporal Variability of Soil Erosion in the Pisha Sandstone Region: Influences of Precipitation and Vegetation

The Pisha sandstone area, situated in the upper and middle reaches of the Yellow River in China, is characterized by severe soil and water erosion, making it one of the most critical regions on the Loess Plateau. The rugged terrain and exposed bedrock complicate management efforts for this area, posing challenges for accurate forecasting using soil erosion models. Through an analysis of terrain, vegetation, and precipitation impacts on soil erosion, this study offers theoretical support for predicting soil erosion within the exposed Pisha sandstone area of the Loess Plateau. This has substantial implications for guiding water and soil conservation measures in this region. Focusing on China’s exposed sandstone area within the Geqiugou watershed, temporal and spatial changes in vegetation cover and land use from 1990 to 2020 were analyzed. The result shows that, from 1990 to 2020, the grassland area has exhibited a consistent downward trend, with successive reductions of 64.86% to 59.46%. The area of low vegetation cover witnessed a significant decline of 59.29% in 2020 compared to that in 1990. The moderate erosion area decreased from 84.52 to 57.17 km2. The significant reduction in soil and water loss can be attributed to the expansion of forest and grassland areas, with the implementation of the Grain for Green project serving as a key policy driver for facilitating this expansion. This study provided a good example of combining rainfall with vegetation coverage to fast estimation soil erosion. A mathematical relationship between the vegetation rainfall coupling index (RV) and soil erosion was established with strong fitting effects, enabling estimation of the soil erosion volume under varying slope conditions within Pisha sandstone areas. The main focus of future soil and water conservation in the Pisha sandstone area should be on effectively managing the channel slope and minimizing exposed bedrock areas through a combination of slope cutting, the application of anticorrosive materials, and the implementation of artificial vegetation planting.

Comparing methods of measuring interest fit: A large prediction study with career choice satisfaction

AbstractVocational interest inventories are widely used in both research and practice to help match people to well‐fitting work environments. However, because there are many different methods to operationalize interest fit, a debate remains regarding the best ways to do so. To empirically inform this debate, our study compared the predictive power of four widely used interest fit indices (i.e., matching scale scores, profile deviance scores, profile correlations, and polynomial regression scores) for predicting career choice satisfaction. Using a large and diverse U.S. sample (N = 257,320), results indicated that among the three single‐term interest fit measures, profile correlations (R2 = .04) explained more variance in career choice satisfaction than matching scale scores (R2 = .02) and profile deviance scores (R2 = .00). By comparison, the full 30‐term polynomial regression model explained the most variance in career choice satisfaction (R2 = .09); in this case, however, the nonlinear terms that capture fit effects only accounted for about 22% (R2 = .02) of the total variance explained by the model. Overall, these results indicate that researchers and practitioners should be cautious of the greater criterion‐related validity of polynomial regression models as fit information may not be a substantial contributor to their predictive capacities. In addition, our findings support the use of profile correlations as a predictive, single‐term measure of interest fit.

Elucidating Rheological Properties of Cementitious Materials Containing Fly Ash and Nanosilica by Machine Learning

Researching the rheology contributes to enhancing the physical and mechanical properties of concrete and promoting material sustainability. Despite the challenges posed by numerous factors influencing viscosity, leveraging machine learning in the era of big data emerges as a viable solution for predicting the general properties of construction materials. This study aims to create models to forecast the rheological properties of cementitious materials containing fly ash and nanosilica. Four models—Random Forest, XGBoost, ANN, and RNN (Stacked LSTM)—are employed to predict and assess shear rate versus shear stress and shear rate versus apparent viscosity curves. Through hyperparameter adjustments, RNN (Stacked LSTM) exhibits excellent performance, achieving a coefficient of determination (R2) of 0.9582 and 0.9257 for the two curves, demonstrating superior statistical parameters and fitting effects. The RNN (Stacked LSTM) exhibited a better generalization ability, suggesting it will be more reliable for future prediction in cementitious material viscosity.

Inverted U-shaped relationship between serum vitamin B12 and α-Klotho levels in US adults: a cross-sectional study

BackgroundSerum vitamin B12 and α-Klotho are important markers associated with aging. Limited studies have been conducted on the relationship between vitamin B12 and α-Klotho.ObjectivesThis study investigated the relationship between circulating α-Klotho and vitamin B12.MethodsA total of 4,502 American adults with circulating vitamin B12 levels and α-Klotho levels from the National Health and Nutrition Examination Survey (2011–2014) were included. A weighted multiple linear regression model was used to evaluate the correlation between vitamin B12 and α-Klotho levels. To clarify potential non-linearities, smoothed curve fitting and threshold effects analysis were employed.ResultsA statistically significant non-linear relationship was found between vitamin B12 levels and circulating α-Klotho levels after adjusting for potential confounders. We observed an inverted U-shaped relationship between serum vitamin B12 levels and circulating α-Klotho levels. Notably, serum vitamin B12 levels below the threshold (1,020 pg/mL) exhibited a positive correlation with circulating α-Klotho levels (β = 0.14, 95% confidence interval (CI): 0.09–0.18, p &amp;lt; 0.0001). Conversely, serum vitamin B12 levels above the threshold (1,020 pg/mL) exhibited a negative correlation with circulating α-Klotho levels (β = −0.12,95% CI: −0.17−−0.06, p &amp;lt; 0.0001). Sensitivity analyses were performed and consistent results were obtained.ConclusionThis study demonstrated an inverted U-shaped relationship between circulating vitamin B12 and α-Klotho in American adults. The optimal concentration of serum vitamin B12 in American adults was found.

Telling (mis)fitting new product stories: The role of consumer orientations, product innovativeness, and message framing on new product evaluations

AbstractExtant research proposes that consumer goal orientation‐message frame fit (consumer–message fit) leads to favorable product evaluations. However, there is evidence that consumer goal orientation‐message frame misfit (consumer–message misfit) at times also result in favorable evaluations of new products. This study develops and tests a novel prediction that shows how consumer–message misfit results in consumers having more favorable responses toward new products when the type of innovation (incremental vs. radical) is perceived as instrumental to achieving the consumer's goals with the product (innovation–consumer fit), creating a kind of fit–misfit effect. Results from four experiments encompassing multiple new product categories support this fit–misfit prediction. We further show that surprise mediates the effect of fit–misfit. This research builds on current theory involving goal orientations and schema‐incongruity, recommends several areas for future research, and presents practical implications for managing new product communication messages.

The Mediating Role of Customer Commitment in the Relationship Between Customer-Company Fit and Customer Voice: An Empirical Study on Restaurant Customers

Objective: This study discusses value congruence (person-organization fit) and voice behaviors, which are frequently discussed in the field of organizational behavior, in the context of marketing. The study aims to examine the effect of customer-company fit (CC fit) on customer voice behavior as well as the role that customer commitment plays in this effect. Design/methodology: Research data was obtained from 390 restaurant customers in a province in Turkey through the convenience sampling method using the survey technique. The SmartPLS program (PLS-SEM) was used to conduct the analyses. The research model was analysed using partial least squares path analysis (PLS-SEM) and bootstrapping (5,000 bootstrap samples). Findings: The findings indicate that CC fit directly affects both customer commitment and customer voice behavior. Furthermore, the findings revealed that customer commitment plays a mediating role CC fit’s effect on customer voice behavior. Theoretical and Practical implications: The present study is the first in the literature to discuss the various relationships between these variables (CC fit, customer commitment and customer voice) together. Another distinctive feature of the study is that the sample consists of restaurant customers. The high-contact nature of restaurant service makes service failures inevitable. For this reason, it is much more important to reveal customer voice behaviors in restaurant services than in other sectors. In this respect, the results of the study may provide guiding information to the sector.

Model for predicting type Ι fatigue crack growth rate in RKE field considering stress gradient

Based on the stress–strain field at the crack tip of Rice-Kujawski-Ellyin (RKE) and considering the stress gradient effect near the crack tip of type I, a fatigue crack growth rate prediction model L-SG (RKE) for type I is proposed in this paper. Firstly, the stress gradient change value of 1 % at the crack tip is considered as the characteristic distance (stress gradient influence range), and the ratio of the equivalent stress to the far-field stress in the stress gradient influence range is defined as the stress gradient influence coefficient ρ; Secondly, the new model L-SG (RKE) is proposed to quantitatively describe the fatigue crack growth behavior by using the stress–strain field at the crack tip of RKE, and the stress gradient influence coefficient ρ is introduced, and then the crack tip passivation radius rp is defined to eliminate the crack tip singularity, and the plastic strain energy failure criterion is combined.; Finally, the prediction effect of the L-SG (RKE) model is verified by 6 metal materials and the fatigue crack growth rate test results of 2 groups of 45 steel CT specimens, and compared with the SHI-CAI (RKE) model. At the same time, based on the R2 fitting effect and the different requirements of the three stages of fatigue crack propagation, the prediction effect of the two prediction models is analyzed, and comprehensive evaluation from two aspects of safety and accuracy. The results show that the L-SG (RKE) prediction model can better reflect the actual fatigue crack propagation behavior, and can meet the requirements of practical engineering for the accuracy and safety of the prediction model. Especially, the prediction results of physical cracks in 45 steel shaft parts by this model agrees well with the experimental data.

Glucocorticoid and glycemic responses to immune challenge in a viviparous snake afflicted with an emerging mycosis.

Disease may be both a cause and consequence of stress, and physiological responses to infectious disease may involve stress coping mechanisms that have important fitness consequences. For example, glucocorticoid and glycemic responses may affect host fitness by altering resource allocation and use in hosts, and these responses may be affected by competing stressors. To better understand the factors that affect host responses to infection, we challenged the immune system of field acclimatized pygmy rattlesnakes, Sistrurus miliarius, with a sterile antigen, lipopolysaccharide (LPS), and measured the glucocorticoid and glycemic response in healthy non-reproductive snakes, snakes afflicted with an emerging mycosis (ophidiomycosis), and pregnant snakes. We hypothesized that LPS challenge would result in a glucocorticoid and glycemic response typical of the vertebrate acute phase response (APR), and therefore predicted that LPS challenge would result in an acute increase in plasma corticosterone (CORT) and a decline in plasma glucose in all individuals. Additionally, we hypothesized that the APR would be attenuated in individuals simultaneously coping with additional challenges to homeostasis (i.e., disease or reproduction). As predicted, immune challenge elicited an acute increase in plasma CORT and a decrease in plasma glucose. Snakes coping with ophidiomycosis and pregnant snakes were able to mount a robust glucocorticoid and hypoglycemic response to LPS challenge, which was contrary to our hypothesis. Our findings clarify directions of causality linking infection, glucocorticoids, and glucose, and emphasize the importance of future research examining the fitness consequences of interactions between stress and disease in wildlife threatened by emerging pathogens.

Association between serum calcium and in-hospital mortality in intensive care unit patients with cerebral infarction: a cohort study

BackgroundThe relationship between serum calcium levels and the prognosis of cerebral infarction remains controversial.PurposeThis study aims to investigate the correlation between serum calcium levels and in-hospital mortality in critically ill patients with ischemic stroke admitted to the intensive care unit (ICU).MethodsA retrospective cohort study was conducted using data from the MIMIC-IV database. Demographic and clinical data of all participants were collected including gender, age, hypertension, diabetes, myocardial infarction, heart failure, chronic obstructive pulmonary disease, hemoglobin, potassium, sodium, anion gap, platelets, white blood cells, glucose, creatinine, Glasgow coma score (GCS), IV-tPA administration (rt-PA), and mechanical thrombectomy (MT). The outcome measure was in-hospital death. Multivariable-adjusted logistic regression analysis, curve fitting, interaction analysis, and threshold effect analysis were employed to evaluate the relationship between serum calcium levels and in-hospital mortality among ICU patients with cerebral infarction.ResultsA total of 2,680 critically ill patients with cerebral infarction were enrolled, with a mean serum calcium level of 8.6 ± 0.8 mg/dL. The overall in-hospital mortality rate was 19.5%, where Group 1 (serum calcium &amp;lt; 8.0 mg/dL) had a mortality rate of 27.7%, Group 2 (serum calcium 8–9 mg/dL) had a rate of 19.8%, and Group 3 (serum calcium ≥ 9 mg/dL) had a rate of 13.9%. There was a non-linear, S-shaped relationship between serum calcium levels and in-hospital mortality. Serum calcium levels within the range of 7.70–9.50 mg/dL were found to be independently associated with increased in-hospital mortality in ICU patients with cerebral infarction. No significant interactions were detected in subgroup analyses, and the results of sensitivity analyses remained stable.ConclusionSerum calcium levels are independently associated with in-hospital mortality in critically ill patients with cerebral infarction in the ICU setting. Within the range of 7.70–9.50 mg/dL, lower serum calcium levels increase the risk of in-hospital death among these patients, emphasizing the importance of close monitoring by ICU physicians.

Strength of seasonality and type of migratory cue determine the fitness consequences of changing phenology for migratory animals

Phenological mismatch has been highlighted as a reason why climate change is causing declines of migratory populations. The likelihood of declines due to phenological mismatch might depend on what cues trigger migration. Migrants that use environmental cues (e.g. temperature, resource availability) to trigger migration are often considered to be less vulnerable than migrants that use temporal information (e.g. photoperiod). We developed a proof‐of‐concept model that demonstrates that which cue type performs better in the context of phenological change can depend on differences in seasonal amplitude between the habitats used by a migrant. Environmental cues perform better than temporal cues when the habitat that undergoes a phenological change has a larger seasonal amplitude. This result aligns with observations that populations of short‐distance migrants that use environmental cues are less likely to decline as a consequence of phenological mismatch than long‐distance avian migrants that use temporal cues. Temporal cues perform better than environmental cues when the habitat that undergoes a phenological change has a smaller seasonal amplitude. This result may correspond to empirical scenarios where the more seasonal habitat is associated with variation in precipitation patterns or human actions that are not changing in phenology. In addition to these results, we offer distinctions that will help clarify future work on phenological mismatch. First, we highlight the difference between the cue accuracy (difference between the timing of migration using the cue and optimal migration timing) and the cue efficacy (the difference between the fitness using the cue and the fitness using optimal migration). Second, we recommend considering both how the benefits available from migrating and the benefits that are captured by migrants change with phenological change.

Extreme positive epistasis for fitness in monosomic yeast strains.

The loss of a single chromosome in a diploid organism halves the dosage of many genes and is usually accompanied by a substantial decrease in fitness. We asked whether this decrease simply reflects the joint damage caused by individual gene dosage deficiencies. We measured the fitness effects of single heterozygous gene deletions in yeast and combined them for each chromosome. This predicted a negative growth rate, that is, lethality, for multiple monosomies. However, monosomic strains remained alive and grew as if much (often most) of the damage caused by single mutations had disappeared, revealing an exceptionally large and positive epistatic component of fitness. We looked for functional explanations by analyzing the transcriptomes. There was no evidence of increased (compensatory) gene expression on the monosomic chromosomes. Nor were there signs of the cellular stress response that would be expected if monosomy led to protein destabilization and thus cytotoxicity. Instead, all monosomic strains showed extensive upregulation of genes encoding ribosomal proteins, but in an indiscriminate manner that did not correspond to their altered dosage. This response did not restore the stoichiometry required for efficient biosynthesis, which probably became growth limiting, making all other mutation-induced metabolic defects much less important. In general, the modular structure of the cell leads to an effective fragmentation of the total mutational load. Defects outside the module(s) currently defining fitness lose at least some of their relevance, producing the epiphenomenon of positive interactions between individually negative effects.

Extreme positive epistasis for fitness in monosomic yeast strains

The loss of a single chromosome in a diploid organism halves the dosage of many genes and is usually accompanied by a substantial decrease in fitness. We asked whether this decrease simply reflects the joint damage caused by individual gene dosage deficiencies. We measured the fitness effects of single heterozygous gene deletions in yeast and combined them for each chromosome. This predicted a negative growth rate, that is, lethality, for multiple monosomies. However, monosomic strains remained alive and grew as if much (often most) of the damage caused by single mutations had disappeared, revealing an exceptionally large and positive epistatic component of fitness. We looked for functional explanations by analyzing the transcriptomes. There was no evidence of increased (compensatory) gene expression on the monosomic chromosomes. Nor were there signs of the cellular stress response that would be expected if monosomy led to protein destabilization and thus cytotoxicity. Instead, all monosomic strains showed extensive upregulation of genes encoding ribosomal proteins, but in an indiscriminate manner that did not correspond to their altered dosage. This response did not restore the stoichiometry required for efficient biosynthesis, which probably became growth limiting, making all other mutation-induced metabolic defects much less important. In general, the modular structure of the cell leads to an effective fragmentation of the total mutational load. Defects outside the module(s) currently defining fitness lose at least some of their relevance, producing the epiphenomenon of positive interactions between individually negative effects.

Career adaptability and work engagement: the roles of person–organization fit and job insecurity

PurposeThe purpose of this study is to examine the relationship between employees’ career adaptability and work engagement. Specifically, this study investigates the mediating role of person‒organization fit in the relationship between career adaptability and work engagement as well as the moderating role of job insecurity in this mediating effect.MethodsWe collected data from 248 full-time employees in China and utilized robust statistical techniques to test a moderated mediation model that includes the constructs of career adaptability, person‒organization fit, job insecurity, and work engagement.ResultsCareer adaptability is positively related to employees’ work engagement, and person‒organization fit mediates the relationship between career adaptability and work engagement. Job insecurity moderates the mediating effects of person‒organization fit in this context. The relationship between person‒organization fit and work engagement is stronger at low (vs. high) levels of job insecurity.ConclusionThis research contributes to theory by demonstrating that the mediating effect of person‒organization fit and the moderating effect of job insecurity represent additional explanations of the impact of career adaptability on work engagement.

Apparent Ophidiomycosis Alters Eastern Copperhead (Agkistrodon contortrix) Behavior and Habitat Use.

Pathogens not only cause mortality but also impose nonlethal fitness consequences. Snakes experience trade-offs associated with behaviors that combat disease but divert time and energy away from other critical activities. The impacts of such behaviors on fitness remain poorly understood, raising concerns amid the emergence of novel herpetofaunal diseases. Ophidiomycosis, caused by the ascomycete fungus Ophidiomyces ophidiicola, impacts free-ranging snakes across North America and has been implicated in declines of several imperiled populations. Although previous ophidiomycosis research has primarily focused on disease-related mortality, few studies have evaluated nonlethal impacts on snake fitness. To address this knowledge gap, we investigated the effects of apparent ophidiomycosis on the behavior, habitat use, and movement of snakes in central New Jersey, USA, from 2020 to 2021. Our focal species was the eastern copperhead (Agkistrodon contortrix), a state species of special concern with limited representation in the ophidiomycosis literature. Although we did not observe mortality in our study population, we found that copperheads with apparent ophidiomycosis (8/31 individuals) displayed significantly different thermoregulatory behaviors than snakes without ophidiomycosis. Specifically, individuals with apparent ophidiomycosis favored areas with less canopy cover, less rock cover, and more coarse woody debris. Our findings suggest that snakes with apparent ophidiomycosis select habitats conducive to initiating behavior-mediated fever, potentially facilitating recovery.

Quantitative simulation and validation of energy carbon emission efficiency changes in Chinese urban agglomerations

In the context of the global energy dilemma, enhancing energy efficiency has inevitably become a pivotal strategy for mitigating energy waste and promoting sustainable development. Urban agglomerations, as growth poles leading high-quality regional economic development, play a significant role in this process. Within these urban agglomerations, the aggregation of various factors and the substitution of energy resources substantially influence the energy carbon emission efficiency (ECEE) of surrounding cities during their development and maturation phases. This study initially employs a three-stage Data Envelopment Analysis (DEA) to quantitatively analyze the ECEE values of 19 urban agglomerations from 2006 to 2020. It then establishes a methodology for calculating the joint intensity (JI) and joint threshold (JT) of ECEE within these urban agglomerations. Finally, a validation process is executed using MATLAB simulation and verification methodology to fit and authenticate the evolutionary patterns of ECEE in Chinese urban agglomerations. The primary objective of this research is to model the evolution of ECEE, thereby exploring the sustainable development pathways for urban agglomerations in China. The research findings indicate that: (1) The results from the three-stage DEA demonstrate that, after removing the influences of external environmental factors and random errors, the comprehensive technical efficiency (TE) of energy carbon emissions for the 19 urban agglomerations in China experienced a wave-like increase, rising from 0.410 to 0.506 between 2006 and 2020. (2) The calculation results of the constructed JI model indicate that the JT values of ECEE for national-level, regional-level, and local-level urban agglomerations are 1006.92, 226.60, and 160.14, respectively. The national-level urban agglomerations have significantly higher JT values and JI than the other two levels of urban agglomerations. (3) The results of the Matlab simulation verification show that 16 urban agglomerations fit well with the wave-like ascending evolutionary pattern. However, four urban agglomerations exhibit an opposite fitting effect due to the influence of their pillar industries or the small number of cities within these accumulations, making them unrepresentative. Consequently, the evolutionary curve of ECEE in Chinese urban agglomerations generally exhibits a wave-like upward trend over time.