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Our goal was to identify predictors of invasive bacterial infection (ie, bacteremia and bacterial meningitis) in febrile infants aged 2-6 months. In our multicenter retrospective cohort, older age and lower temperature identified infants at low risk for invasive bacterial infection who could safely avoid routine testing.

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BACKGROUND AND AIM: A plateau in oxygen uptake ([Formula: see text]) during an incremental cardiopulmonary exercise test (CPET) to volitional exhaustion appears less likely to occur in special and clinical populations. Secondary maximal oxygen uptake ([Formula: see text]) criteria have been shown to commonly underestimate the actual [Formula: see text]. The verification phase protocol might determine the occurrence of 'true' [Formula: see text] in these populations. The primary aim of the current study was to systematically review and provide a meta-analysis on the suitability of the verification phase for confirming 'true' [Formula: see text] in special and clinical groups. Secondary aims were to explore the applicability of the verification phase according to specific participant characteristics and investigate which test protocols and procedures minimise the differences between the highest [Formula: see text] values attained in the CPET and verification phase. METHODS: Electronic databases (PubMed, Web of Science, SPORTDiscus, Scopus, and EMBASE) were searched using specific search strategies and relevant data were extracted from primary studies. Studies meeting inclusion criteria were systematically reviewed. Meta-analysis techniques were applied to quantify weighted mean differences (standard deviations) in peak [Formula: see text] from a CPET and a verification phase within study groups using random-effects models. Subgroup analyses investigated the differences in [Formula: see text] according to individual characteristics and test protocols. The methodological quality of the included primary studies was assessed using a modified Downs and Black checklist to obtain a level of evidence. Participant-level [Formula: see text] data were analysed according to the threshold criteria reported by the studies or the inherent measurement error of the metabolic analysers and displayed as Bland-Altman plots. RESULTS: Forty-three studies were included in the systematic review, whilst 30 presented quantitative information for meta-analysis. Within the 30 studies, the highest mean [Formula: see text] values attained in the CPET and verification phase protocols were similar (mean difference = -0.00 [95% confidence intervals, CI = -0.03 to 0.03] L·min-1, p = 0.87; level of evidence, LoE: strong). The specific clinical groups with sufficient primary studies to be meta-analysed showed a similar [Formula: see text] between the CPET and verification phase (p > 0.05, LoE: limited to strong). Across all 30 studies, [Formula: see text] was not affected by differences in test protocols (p > 0.05; LoE: moderate to strong). Only 23 (53.5%) of the 43 reviewed studies reported how many participants achieved a lower, equal, or higher [Formula: see text] value in the verification phase versus the CPET or reported or supplied participant-level [Formula: see text] data for this information to be obtained. The percentage of participants that achieved a lower, equal, or higher [Formula: see text] value in the verification phase was highly variable across studies (e.g. the percentage that achieved a higher [Formula: see text] in the verification phase ranged from 0% to 88.9%). CONCLUSION: Group-level verification phase data appear useful for confirming a specific CPET protocol likely elicited [Formula: see text], or a reproducible [Formula: see text], for a given special or clinical group. Participant-level data might be useful for confirming whether specific participants have likely elicited [Formula: see text], or a reproducible [Formula: see text], however, more research reporting participant-level data is required before evidence-based guidelines can be given. TRIAL REGISTRATION: PROSPERO (CRD42021247658) https://www.crd.york.ac.uk/prospero.

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ABSTRACT: Pérez-Ifrán, P, Magallanes, CA, de S. Castro, FA, Astorino, TA, and Benítez-Flores, S. Extremely low-volume burpee interval training equivalent to 8 minutes per session improves vertical jump compared with sprint interval training in real-world circumstances. J Strength Cond Res 38(1): 10-20, 2024-The aim of this study was to compare the cardiometabolic and physical effects of 2 time-matched high-intensity programs in a real-world environment. Forty-three active and healthy adults (sex = 31 men and 12 women; age = 27 ± 5 years; peak heart rate [HR peak ] = 190.7 ± 10.6 beat·min -1 ) were randomized to 2 very low-volume protocols (∼8 minutes): sprint interval training (SIT) ( n = 15), burpee interval training (BIT) ( n = 15), and control (CON) ( n = 13). Subjects in SIT and BIT performed 5 days of 10 × 4 second "all-out" efforts with 30 seconds of recovery. Body composition, blood pressure, countermovement jump (CMJ), 10-m sprint, shuttle run test (SRT), autonomic modulation , self-efficacy, and intention were evaluated before and after training. Sprint interval training elicited a higher %HR peak , energy expenditure, rating of perceived exertion category ratio 10 scale, and feeling scale than BIT ( p < 0.05). SRT distance was significantly improved in SIT ( p = 0.03, d = 0.62), whereas CMJ height was significantly enhanced in BIT ( p = 0.0014, d = 0.72). Self-efficacy progressively worsened for SIT than for BIT as sessions increased, and significant differences were found in 5× a week frequency between protocols ( p = 0.040, d = 0.79). No differences in intention to engage were detected between the regimens ( p > 0.05). No changes were observed in body composition, blood pressure, 10-m sprint, SRTV̇O 2max , or autonomic variables with training ( p > 0.05). Results exhibit that extremely low-volume SIT improved running performance, whereas BIT increased the vertical jump.

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Predators must contend with numerous challenges to successfully find and subjugate prey. Complex traits related to hunting are partially controlled by a large number of co-evolved genes, which may be disrupted in hybrids. Accordingly, research on the feeding ecology of animals in hybrid zones has shown that hybrids sometimes exhibit transgressive or novel behaviors, yet for many taxa, empirical studies of predation and diet across hybrid zones are lacking. We undertook the first such field study for a hybrid zone between two snake species, the Mojave rattlesnake (Crotalus scutulatus) and the prairie rattlesnake (Crotalus viridis). Specifically, we leveraged established field methods to quantify the hunting behaviors of animals, their prey communities, and the diet of individuals across the hybrid zone in southwestern New Mexico, USA. We found that, even though hybrids had significantly lower body condition indices than snakes from either parental group, hybrids were generally similar to non-hybrids in hunting behavior, prey encounter rates, and predatory attack and success. We also found that, compared to C. scutulatus, C. viridis was significantly more active while hunting at night and abandoned ambush sites earlier in the morning, and hybrids tended to be more viridis-like in this respect. Prey availability was similar across the study sites, including within the hybrid zone, with kangaroo rats (Dipodomys spp.) as the most common small mammal, both in habitat surveys and the frequency of encounters with hunting rattlesnakes. Analysis of prey remains in stomachs and feces also showed broad similarity in diets, with all snakes preying primarily on small mammals and secondarily on lizards. Taken together, our results suggest that the significantly lower body condition of hybrids does not appear to be driven by differences in their hunting behavior or diet and may instead relate to metabolic efficiency or other physiological traits we have not yet identified.

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Hybridization facilitates recombination between divergent genetic lineages and can be shaped by both neutral and selective processes. Upon hybridization, loci with no net fitness effects introgress randomly from parental species into the genomes of hybrid individuals. Conversely, alleles from one parental species at some loci may provide a selective advantage to hybrids, resulting in patterns of introgression that do not conform to random expectations. We investigated genomic patterns of differential introgression in natural hybrids of two species of Caribbean anoles, Anolis pulchellus and A. krugi in Puerto Rico. Hybrids exhibit A. pulchellus phenotypes but possess A. krugi mitochondrial DNA, originated from multiple, independent hybridization events, and appear to have replaced pure A. pulchellus across a large area in western Puerto Rico. Combining genome-wide SNP datasets with bioinformatic methods to identify signals of differential introgression in hybrids, we demonstrate that the genomes of hybrids are dominated by pulchellus-derived alleles and show only 10%-20% A. krugi ancestry. The majority of A. krugi loci in hybrids exhibit a signal of non-random differential introgression and include loci linked to genes involved in development and immune function. Three of these genes (delta like canonical notch ligand 1, jagged1 and notch receptor 1) affect cell differentiation and growth and interact with mitochondrial function. Our results suggest that differential non-random introgression for a subset of loci may be driven by selection favouring the inheritance of compatible mitochondrial and nuclear-encoded genes in hybrids.

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OBJECTIVE: To map out the studies that have investigated the associations of polypharmacy and/or potentially inappropriate medication (PIM) use with physical activity and sedentary time in older adults. METHODS: We conducted a literature search from inception to December 2022 in PubMed, Embase, Web of Science, and Scopus. INCLUSION CRITERIA: observational studies including older adults (≥60 years); English, Portuguese, and Spanish languages; any definition of polypharmacy; implicit and explicit criteria of PIM use; physical activity and/or sedentary time data. RESULTS: Fourteen cross-sectional studies were included; 11 defined polypharmacy as ≥5 medications (prevalence ranging from 9.5 % to 57 %). No study reported information on PIM use. Most studies included participants aged <80 years. Twelve studies included self-reported measures of physical activity, while two studies used accelerometer-measured physical activity. Ten studies included analyses adjusted for confounders, and nine considered polypharmacy as an outcome. All of them demonstrated an inverse association between physical activity and polypharmacy, irrespective of the definition of polypharmacy and the assessment method employed (self-reported or accelerometry). One study reported an inverse association between polypharmacy (as the exposure) and physical activity (as the outcome). None of the studies investigated the association between sedentary time and polypharmacy. CONCLUSIONS: Limited evidence suggests an inverse association between physical activity and polypharmacy in older adults. However, the relationship between PIM use, physical activity, and sedentary time remains unknown. Longitudinal studies utilizing objectively-measured physical activity and sedentary time are needed to better clarify the relationship between these movement behaviors and polypharmacy and/or PIM use in older adults.

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Motivation states for physical activity and sedentarism potentially vary from moment to moment. The CRAVE scale (Cravings for Rest and Volitional Energy Expenditure) was developed to assess transient wants and desires to move. Three studies were conducted with the aims of: (1) translating and validating the scale in Brazilian Portuguese, (2) examining changes with exercise, and (3) determining the best single-item for Move and Rest subscales for English and Portuguese. In Study 1, six bilingual speakers translated the scale into Brazilian Portuguese [named Anseios por Repouso e Gastos com Energia (ARGE)]. The ARGE had good content validity coefficients across three dimensions (0.89-0.91), as determined by three independent, bilingual referees. 1,168 participants (mean age = 30.6, SD = 12.2) from across Brazil completed an online version of the ARGE. An Exploratory Factor Analysis found two clear, oblique, and inversely related factors (Move and Rest; GFI = 1.00, RMSR = 0.03). Reliability was good (Cronbach α's: 0.93 and 0.92). Two models of the scale (10 vs. 13 items) were compared with Confirmatory Factor Analysis. The previously validated version using 10 scored items (GFI = 1.00, RMSEA = 0.07, RMSR = 0.02) outperformed the version scored with 13 items. State anxiety and exercise behavior had small associations with Move and Rest (-0.20 to 0.26). In Study 2, ARGE Move scores had high correspondence post-session (ICC = 0.83) for 9 women performing short Sprint Interval Training (sSIT; 6 sessions). Large, but non-significant, effects were detected for changes in motivation states with sSIT. In Study 3, IRT analyses found that for the United States sample, "be physically active" and "be still" were the most representative items for Move and Rest, respectively, while for the Brazil sample they were "exert my muscles" and "be a couch potato." Overall, it was found that: (A) the ARGE scale demonstrated good psychometric properties, (B) the original scoring (with 10 items) resulted in the best model, (C) it had small associations with exercise behavior, and (D) the subscales were reduced to single items that varied by country, indicating potential cultural differences in the concept of motivation states for physical activity.

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The tomato fruitworm Helicoverpa armigera (Hübner) is regarded as a serious pest that affects a great number of field crops globally. One of the environmentally safe alternatives to the utilization of insecticides is controlling H. armigera via the release of biological control agents by employing parasitoids, e.g., trichogrammatid species. One of the desired parasitoids indigenous to southwestern Iran is Trichogramma euproctidis (Girault). To anticipate the outcomes of augmentative releases of T. euproctidis in the field, the numerical and functional responses of female T. euproctidis that parasitizes the eggs of H. armigera were determined in the laboratory. The densities of host eggs per glass tube arena (length: 10 cm, diameter: 1 cm) were 2, 4, 8, 16, 32, 64, or 128 individuals. The functional response to the eggs of H. armigera indicated Holling's type II response. The estimated handling time and attack rate from the random parasitoid equation were 0.6898 h and 0.00823 h, respectively. This indicates that, at the maximum level, each T. euproctidis was capable of parasitizing 34.79 eggs a day. At the 128 host egg density, the number of eggs laid, that is, the numerical response, ascended as the density of host eggs increased up to a maximum of 89.90 eggs per female. According to the obtained results of the present investigation, T. euproctidis can serve as an appropriate candidate for augmentative biological control of H. armigera. Nevertheless, it is necessary to conduct complementary experiments in greenhouses and open fields.

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OBJECTIVE: To determine the association between adjunct corticosteroid therapy and quality of life (QoL) outcomes in children with signs and symptoms of lower respiratory tract infection and clinical suspicion for community-acquired pneumonia (CAP) in the emergency department (ED). METHODS: Secondary analysis from a prospective cohort study of children aged 3 months to 18 years with signs and symptoms of LRTI and a chest radiograph for suspected CAP in the ED, excluding children with recent (within 14 days) systemic corticosteroid use. The primary exposure was receipt of corticosteroids during the ED visit. Outcomes were QoL measures and unplanned visits. Multivariable regression was used to evaluate the association between corticosteroid therapy and outcomes. RESULTS: Of 898 children, 162 (18%) received corticosteroids. Children who received corticosteroids were more frequently boys (62%), Black (45%), had history of asthma (58%), previous pneumonia (16%), presence of wheeze (74%), and more severe illness at presentation (6%). Ninety-six percent were treated for asthma as defined by report of asthma or receipt of ß-agonist in the ED. Receipt of corticosteroids was not associated with QoL measures: days of activity missed (adjusted incident rate ratio [aIRR], 0.84; 95% confidence interval [CI], 0.63-1.11) and days of work missed (aIRR, 0.88; 95% CI, 0.60-1.27). There was a statistically significant interaction between age (>2 years) and corticosteroids receipt; the patients had fewer days of activity missed (aIRR, 0.62; 95% CI, 0.46-0.83), with no effect on children 2 years or younger (aIRR, 0.83; 95% CI, 0.54-1.27). Corticosteroid treatment was not associated with unplanned visit (odds ratio, 1.37; 95% CI, 0.69-2.75). CONCLUSIONS: In this cohort of children with suspected CAP, receipt of corticosteroids was associated with asthma history and was not associated with missed days of activity or work, except in a subset of children aged older than 2 years.

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Herbicide mixtures are used to increase the spectrum of weed control and to manage weeds with target-site resistance to some herbicides. However, the effect of mixtures on the evolution of herbicide resistance caused by enhanced metabolism is unknown. This study evaluated the effect of a fenoxaprop-p-ethyl and imazethapyr mixture on the evolution of herbicide resistance in Echinochloa crus-galli using recurrent selection at sublethal doses. The progeny from second generations selected with the mixture had lower control than parental plants or the unselected progeny. GR50 increased 1.6- and 2.6-fold after two selection cycles with the mixture in susceptible (POP1-S) and imazethapyr-resistant (POP2-IR) biotypes, respectively. There was evidence that recurrent selection with this sublethal mixture had the potential to evolve cross-resistance to diclofop, cyhalofop, sethoxydim, and quinclorac. Mixture selection did not cause increased relative expression for a set of analyzed genes (CYP71AK2, CYP72A122, CYP72A258, CYP81A12, CYP81A14, CYP81A21, CYP81A22, and GST1). Fenoxaprop, rather than imazethapyr, is the main contributor to the decreased control in the progenies after recurrent selection with the mixture in low doses. This is the first study reporting the effect of a herbicide mixture at low doses on herbicide resistance evolution. The lack of control using the mixture may result in decreased herbicide sensitivity of the weed progenies. Using mixtures may select important detoxifying genes that have the potential to metabolize herbicides in patterns that cannot currently be predicted. The use of fully recommended herbicide rates in herbicide mixtures is recommended to reduce the risk of this type of resistance evolution.

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PURPOSE: The postural transition from sitting to standing is a moment of dysautonomic occurrence in individuals with Spinal Cord Injury (SCI). Different tools can be used to minimize this event, such as virtual reality. Thus, we aimed to analyze cardiac autonomic modulation in individuals with SCI during postural transition from the sitting to orthostatism position using a cognitive virtual reality (VR) task. METHODS: Individuals with and without SCI were positioned on the Easy Stand® device, sitting at rest, at 0° considering the angle between the seat and the floor, elevation at 45°, and orthostatism at 90°, for 5 minutes in each position. Heart rate variability (HRV) measures of sympathovagal balance were collected (heart rate receiver: Polar V800). The groups were subdivided into two groups, one that performed VR as an intervention during the postural angle changes and another group that did not perform VR. RESULTS: We evaluated 76 individuals, 40 with a medical diagnosis of SCI and 36 who composed the able-bodied control group without SCI, matched by age and sex. The HRV results showed that the SCI group who performed the task in VR demonstrated no significant difference in parasympathetic activation and global variability between the sitting versus 90° positions. There was better sympathovagal balance in SCI and able-bodied control groups who performed the VR task between the sitting versus 90° positions. CONCLUSION: The use of a VR task seems to contribute to better sympathovagal balance, with the potential to reduce dysautonomia during postural changes.

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ABSTRACT: Benítez-Flores, S, de S. Castro, FA, Lusa Cadore, E, and Astorino, TA. Sprint interval training attenuates neuromuscular function and vagal reactivity compared with high-intensity functional training in real-world circumstances. J Strength Cond Res 37(5): 1070-1078, 2023-The aim of this study was to compare the acute cardiovascular and neuromuscular effects of 3 time-matched sessions of high-intensity training. Eighteen moderately active adults (9 women and 9 men [age: 23 ± 2.9 years; maximum oxygen consumption (V̇ o2 max): 47.6 ± 4.1 ml·kg -1 ·min -1 ]) performed three low-volume (∼9 minutes) sessions in a randomized order: sprint interval training (SIT), burpee interval training (BIT) (10 × 5 seconds efforts × 35 seconds recovery), and vigorous intensity continuous training (VICT) (6 minutes 5 seconds of running at ∼85% of peak heart rate [HR peak ]). Indices related to heart rate (HR), neuromuscular performance (counter movement jump height [CMJ height ] and squat and bench press power), and autonomic balance (heart rate recovery and heart rate variability [HRR and HRV] )were monitored during exercise. Sprint interval training and VICT elicited a higher HR mean (171.3 ± 8.4 and 166.5 ± 7.5 vs. 150.5 ± 13.6 b·min -1 , p < 0.001) and time of ≥90%HR peak (133.3 ± 117.4 and 110 ± 128.9 vs. 10 ± 42.4 seconds, p < 0.01) than BIT. Sprint interval training exhibited a slower HRR and lower HRV than BIT and VICT ( p < 0.05) postsession. Moreover, only SIT resulted in a significant decline ( p < 0.01) in CMJ height (34.7 ± 7.2 to 33.5 ± 7.2 cm), relative squat mean power (25.5 ± 4.5 to 23.8 ± 4.9 W·kg -1 ), and relative bench press peak power (6.9 ± 2.4 to 6.2 ± 2.5 W·kg -1 ). Results revealed that SIT diminishes the sympathovagal reactivation and neuromuscular performance compared with work-matched BIT and VICT.

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PURPOSE: Optimized strategies for risk classification are essential to tailor therapy for patients with biologically distinctive disease. Risk classification in pediatric acute myeloid leukemia (pAML) relies on detection of translocations and gene mutations. Long noncoding RNA (lncRNA) transcripts have been shown to associate with and mediate malignant phenotypes in acute myeloid leukemia (AML) but have not been comprehensively evaluated in pAML. METHODS: To identify lncRNA transcripts associated with outcomes, we evaluated the annotated lncRNA landscape by transcript sequencing of 1,298 pediatric and 96 adult AML specimens. Upregulated lncRNAs identified in the pAML training set were used to establish a regularized Cox regression model of event-free survival (EFS), yielding a 37 lncRNA signature (lncScore). Discretized lncScores were correlated with initial and postinduction treatment outcomes using Cox proportional hazards models in validation sets. Predictive model performance was compared with standard stratification methods by concordance analysis. RESULTS: Training set cases with positive lncScores had 5-year EFS and overall survival rates of 26.7% and 42.7%, respectively, compared with 56.9% and 76.3% with negative lncScores (hazard ratio, 2.48 and 3.16; P < .001). Pediatric validation cohorts and an adult AML group yielded comparable results in magnitude and significance. lncScore remained independently prognostic in multivariable models, including key factors used in preinduction and postinduction risk stratification. Subgroup analysis suggested that lncScores provide additional outcome information in heterogeneous subgroups currently classified as indeterminate risk. Concordance analysis showed that lncScore adds to overall classification accuracy with at least comparable predictive performance to current stratification methods that rely on multiple assays. CONCLUSION: Inclusion of the lncScore enhances predictive power of traditional cytogenetic and mutation-defined stratification in pAML with potential, as a single assay, to replace these complex stratification schemes with comparable predictive accuracy.

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COVID-19 is a heterogenous disease. Biomarker-based approaches may identify patients at risk for severe disease, who may be more likely to benefit from specific therapies. Our objective was to identify and validate a plasma protein signature for severe COVID-19. DESIGN: Prospective observational cohort study. SETTING: Two hospitals in the United States. PATIENTS: One hundred sixty-seven hospitalized adults with COVID-19. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: We measured 713 plasma proteins in 167 hospitalized patients with COVID-19 using a high-throughput platform. We classified patients as nonsevere versus severe COVID-19, defined as the need for high-flow nasal cannula, mechanical ventilation, extracorporeal membrane oxygenation, or death, at study entry and in 7-day intervals thereafter. We compared proteins measured at baseline between these two groups by logistic regression adjusting for age, sex, symptom duration, and comorbidities. We used lead proteins from dysregulated pathways as inputs for elastic net logistic regression to identify a parsimonious signature of severe disease and validated this signature in an external COVID-19 dataset. We tested whether the association between corticosteroid use and mortality varied by protein signature. One hundred ninety-four proteins were associated with severe COVID-19 at the time of hospital admission. Pathway analysis identified multiple pathways associated with inflammatory response and tissue repair programs. Elastic net logistic regression yielded a 14-protein signature that discriminated 90-day mortality in an external cohort with an area under the receiver-operator characteristic curve of 0.92 (95% CI, 0.88-0.95). Classifying patients based on the predicted risk from the signature identified a heterogeneous response to treatment with corticosteroids (p = 0.006). CONCLUSIONS: Inpatients with COVID-19 express heterogeneous patterns of plasma proteins. We propose a 14-protein signature of disease severity that may have value in developing precision medicine approaches for COVID-19 pneumonia.

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PURPOSE: Arterial stiffness is a subclinical marker of cardiovascular disease (CVD). The pre-frailty phenotype is associated with a higher risk for CVD. This study investigated the association between the pre-frailty phenotype and arterial stiffness in community-dwelling older adults without diagnosed CVD. METHODS: In total, 249 community-dwelling older adults aged 60-80 years were included in this cross-sectional study. The pre-frailty phenotype was defined by the standardized Fried criteria (muscle weakness; slow walking speed; low physical activity; unintentional weight loss; self-reported exhaustion). Participants with one or two standardized Fried criteria were classified as pre-frail and those with zero criteria as robust. Arterial stiffness was measured by aortic pulse wave velocity (aPWV). The data were analyzed using the generalized linear model. RESULTS: From 249 participants (66.1 ± 5.3 years; 79.5% females), 61.8% (n = 154) were pre-frail and 38.2% (n = 95) robust. Pre-frail older adults had a higher aPWV (ß = 0.19 m/s; p = 0.007) compared to their robust peers. CONCLUSIONS: The pre-frailty phenotype was associated with higher arterial stiffness in community-dwelling older adults aged 60-80 years. Pre-frail older adults may have a higher risk for CVD.

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OBJECTIVE: To investigate the moderating effect of step count and peak cadence on the relationship of sedentary time and cardiometabolic disease risk in community-dwelling older adults. METHODS: This cross-sectional study included 248 older adults aged 60-80 years without cardiovascular disease (66.0 ± 4.6 years of age; 78 % females). Sedentary time, step count and peak cadence were measured by a hip-worn accelerometer for seven days. Peak cadence was defined as the average of 30 min of the day (but not necessarily consecutive) with the highest cadence (steps per minute) for all valid days. Cardiometabolic disease risk was defined using a sex-specific continuous metabolic syndrome score (cMetS). Sedentary time was used as an explanatory variable for cMetS and step count and peak cadence as moderators. The analyses were adjusted for known cardiometabolic disease risk factors and accelerometer wear time. The Johnson-Neyman technique was used to specify the value of moderator variables at which the significant relationship between sedentary time and cMetS disappears. RESULTS: Both step count (ß = -0.186, P = 0.032) and peak cadence (ß = -0.003, P = 0.007) showed a moderating effect on the relationship of sedentary time and cMetS. The association of sedentary time and cMetS was not statistically significant (p > 0.05) when step count or peak cadence exceed 5715 steps per day and 57 steps per minute, respectively. CONCLUSION: Steps per day and peak cadence moderate the association of sedentary time and cardiometabolic disease risk in older adults. Therefore, steps per day and peak cadence seem to offset the deleterious effects of sedentary time on cardiometabolic health in this population.

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Ecological conditions shape (adaptive) responses at the molecular, anatomical, and behavioral levels. Understanding these responses is key to predict the outcomes of intra- and inter-specific competitions and the evolutionary trajectory of populations. Recent technological advances have enabled large-scale molecular (e.g., RNAseq) and behavioral (e.g., computer vision) studies, but the study of anatomical responses to ecological conditions has lagged behind. Here, we highlight the role of X-ray micro-computed tomography (micro-CT) in generating in vivo and ex vivo 3D imaging of anatomical structures, which can enable insights into adaptive anatomical responses to ecological environments. To demonstrate the application of this method, we manipulated the larval density of Drosophila melanogaster Meigen flies and applied micro-CT to investigate the anatomical responses of the male reproductive organs to varying intraspecific competition levels during development. Our data is suggestive of two classes of anatomical responses which broadly agree with sexual selection theory: increasing larval density led to testes and ejaculatory duct to be overall larger (in volume), while the volume of accessory glands and, to a lesser extent, ejaculatory duct decreased. These two distinct classes of anatomical responses might reflect shared developmental regulation of the structures of the male reproductive system. Overall, we show that micro-CT can be an important tool to advance the study of anatomical (adaptive) responses to ecological environments.

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