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ABSTRACT: Dairy cow fertility is a complex trait that depends on the cow's physiological status, the farm's environmental and management conditions, and their interactions. Already the slightest improvement in fertility can positively impact a farm's profitability and sustainability. In research, milk progesterone (P4) has often been used as an accurate and feasible way to identify a dairy cow's reproduction status. Moreover, in Europe and Canada, it has been used to improve fertility management on commercial farms as it allows to accurately identify reproduction issues, pregnancy, and the optimal insemination window. An on-farm P4 device (OPD) automatically samples, measures, and monitors the milk P4 concentration of individual cows. To this end, the P4 data are smoothed to be robust for measurement errors and outliers, and fixed thresholds are used to estimate the time of luteolysis preceding ovulation, thereby generating a luteolysis alert (LA). By smoothing the P4 data, the OPD introduces a time lag on the LA. Variation in this time lag is not considered in the estimation of the optimal insemination window that is advised to the farmer. Ignoring this variation might decrease the accuracy of the optimal insemination window and, therefore, decreases the likelihood of conception. We hypothesize that considering the length of the time lag and adapting the advice accordingly improves the conception rate. This observational retrospective study uses an extensive dataset from 17 commercial dairy farms that are equipped with an OPD. We estimated the time lag on the alerts and evaluated their relationship with the interval from LA to insemination for successful (n = 3,721) and unsuccessful inseminations (n = 3,896) separately. Results showed that the probability of conception increases when a longer LA time lag is compensated with a shorter interval from LA to insemination and vice versa. In addition, for successful inseminations, we found a clear negative relation between the time lag and the interval from LA to insemination and the interval was significantly shorter when the time lag of the LA was longer. This negative relation between time lag and interval from LA to insemination was less pronounced for unsuccessful inseminations. Additionally, we evaluated the conception rates for inseminations that are performed too early, in time, or too late with respect to the optimal insemination window advised by the OPD, in function of their associated time lags. We found that, for inseminations that were preceded by a short time lag (

Abstract Urban and roadside trees contribute to health and resilience. However, when trees or branches fall, it can cause injuries or deaths. This study examined trends and variations of injuries and deaths due to tree failure in The Netherlands from 1998 to 2021, considering urban–rural location, sex, age and traffic mode. This study is the first to describe long-term trends in injuries and deaths due to tree failure from 1998–2021. The standardised rate of injuries per 1,000,000 population increased from 0.14 (SE 0.10) in 1998 to 0.91 (SE 0.21) in 2021, with an annual percentage increase of 5.3% (p = 0.002). The data shows a strong increase for rural areas, contrary to urban ones. The annual percentage increase in rural areas was 13.2% (p

Yuedonghei (YDH) is the only local pig breed with full black hair among the four well-known local pig breeds originated and distributed in Guangdong province, China, which caters to the consumers’ preference of the local market of 127 million residents and thus brings a significantly above-average price. However, considerable genetic introgression (GI) has been reported for the YDH population, i.e., gene flow into YDH from other pig breeds, which is mainly due to the recent crossbreeding with several mainstream breeds for upgrading reasons. Therefore, this study aimed to evaluate the GI as well as the conservation status in the current YDH population and test the feasibility of advanced optimum contribution selection (aOCS) in alleviating GI in YDH. We first analysed the genetic diversity, ancestral structure, population structure, and phylogeny of 360 YDH relative to 782 publicly downloaded pigs of 42 Eurasian or American breeds and wild boars, based on single nucleotide polymorphism chip data. Then, we selected 304 initial YDH and stochastically simulated a practical conservation programme that spanned 10 discrete generations and implemented haplotype segment-based aOCS in every generation. The expected and observed heterozygosity of 360 YDH were 0.344 and 0.336. The linkage disequilibrium-based recent effective population size (Ne) was 32.89. Considerable GI amounting to 32.9% foreign ancestry was found in 28 lowly related YDH individuals using admixture analysis. In the simulated YDH conservation programme, the average native genomic contribution was increased from 50.4 to 71.4% while maintaining a Ne of 100 by controlling classic kinship and native kinship. Our study showed that segment-based aOCS that required only genomic data can be used to alleviate GI in the current YDH population and meanwhile increase its Ne, which provided strategic insights into the sustainable conservation of local genetic resources of livestock.

This article is one of the first attempts to study the mechanisms of foreign language learning by children with DLD. We test the effectiveness of a cognate intervention aiming to enhance cross-linguistic awareness of Dutch-speaking primary-school pupils with DLD, as part of their English as a Foreign Language (EFL) curriculum. The participants were learning English as a school subject in the last three years of special primary education in the Netherlands (ages 8;11-13;8). The intervention group (n = 41) received 12 short lessons on cognate relationships over the course of 14 weeks. The control group (n = 46), matched to the intervention group on the amount and intensity of foreign language instruction, received their regular English lessons that were mainly implicit and skill-based. The study used a pre-test--post-test design and compared the development of English word recognition in the two groups, at the same time controlling for the amount of prior EFL instruction and out-of-school exposure to English. The performance at pre-test was already high, particularly on cognates. Word recognition in the control group did not improve over the course of the 14 weeks. The performance of the intervention group showed significant improvement from pre-test to post-test. After the intervention, they recognized not only more of the words practised in the lessons but also more nontreated cognates, which demonstrates that the intervention participants developed a cognate strategy that allowed them to recognize more English words based on similarity to Dutch. We conclude that explicit cognate instruction implemented in a regular classroom setting facilitates the development of EFL vocabulary in special primary education.

Abstract Two previously described QTL mapping methods, which combine linkage analysis (LA) and linkage disequilibrium analysis (LD), were compared for their ability to detect and map multiple QTL. The methods were tested on five different simulated data sets in which the exact QTL positions were known. Every simulated data set contained two QTL, but the distances between these QTL were varied from 15 to 150 cM. The results show that the single QTL mapping method (LDLA) gave good results as long as the distance between the QTL was large (> 90 cM). When the distance between the QTL was reduced, the single QTL method had problems positioning the two QTL and tended to position only one QTL, i.e. a "ghost" QTL, in between the two real QTL positions. The multi QTL mapping method (MP-LDLA) gave good results for all evaluated distances between the QTL. For the large distances between the QTL (> 90 cM) the single QTL method more often positioned the QTL in the correct marker bracket, but considering the broader likelihood peaks of the single point method it could be argued that the multi QTL method was more precise. Since the distances were reduced the multi QTL method was clearly more accurate than the single QTL method. The two methods combine well, and together provide a good tool to position single or multiple QTL in practical situations, where the number of QTL and their positions are unknown.

Abstract Two random regression models, where the effect of a putative QTL was regressed on an environmental gradient, are described. The first model estimates the correlation between intercept and slope of the random regression, while the other model restricts this correlation to 1 or -1, which is expected under a bi-allelic QTL model. The random regression models were compared to a model assuming no gene by environment interactions. The comparison was done with regards to the models ability to detect QTL, to position them accurately and to detect possible QTL by environment interactions. A simulation study based on a granddaughter design was conducted, and QTL were assumed, either by assigning an effect independent of the environment or as a linear function of a simulated environmental gradient. It was concluded that the random regression models were suitable for detection of QTL effects, in the presence and absence of interactions with environmental gradients. Fixing the correlation between intercept and slope of the random regression had a positive effect on power when the QTL effects re-ranked between environments.

Abstract Extinction of breeds threatens genetic diversity of livestock species. The need to conserve genetic diversity is widely accepted but involves in general two questions: (i) is the expected loss of diversity in a set of breeds within a defined future time horizon large enough to establish a conservation plan, and if so (ii) which breeds should be prioritised for such a conservation plan? The present study uses a marker assisted methodology to address these questions. The methodology combines core set diversity measures with a stochastic method for the estimation of expected future diversity and breed marginal diversities. The latter is defined as the change in the total diversity of all breeds caused by a one unit decrease in extinction probability of a particular breed. The stochastic method was validated by means of simulations. A large field data set consisting of 44 North Eurasian cattle breeds was analysed using simplified determined extinction probabilities. The results show that the expected loss of diversity in this set within the next 20 to 50 years is between 1 and 3% of the actual diversity, provided that the extinction probabilities which were used are approximately valid. If this loss is to be reduced, it is sufficient to include those three to five breeds with the highest marginal diversity in a conservation scheme.

Abstract This study was designed to reveal any differences in effects of fast created versus total inbreeding on reproduction and body weights in mice. A line selected for large litter size for 124 generations (H) and a control line (K) maintained without selection for the same number of generations were crossed (HK) and used as a basis for the experiment. Within the HK cross, full sib, cousin or random mating were practised for two generations in order to create new inbreeding (IBF) at a fast rate. In the first generation of systematic mating, old inbreeding was regenerated in addition to creation of new inbreeding from the mating design giving total inbreeding (IBT). The number of pups born alive (NBA) and body weights of the animals were then analysed by a model including both IBT and IBF. The IBT of the dam was in the present study found to reduce the mean NBA with -0.48 (± 0.22) (p < 0.05) pups per 10% increase in the inbreeding coefficient, while the additional effect of IBF was -0.42 (± 0.27). For the trait NBA per female mated, the effect of IBT was estimated to be -0.45 (± 0.29) per 10% increase in the inbreeding coefficient and the effect of IBF was -0.90 (± 0.37) (p < 0.05) pups. In the present study, only small or non-significant effects of IBF of the dam could be found on sex-ratio and body weights at three and six weeks of age in a population already adjusted for IBT.

Abstract The need for conservation of farm animal genetic resources is widely accepted. A key question is the choice of breeds to be conserved. For this purpose, a core set of breeds was introduced in that the total genetic variance of a hypothetical quantitative trait was maximised (MVT core set). For each breed the relative contribution to the core set was estimated and the breeds were ranked for conservation priority according to their relative contribution. The method was based on average kinships between and within breeds and these can be estimated using genetic marker data. The method was compared to a recently published core set method that maximises the variance of a hypothetical population that could be obtained by interbreeding the conserved breeds (MVO core set). The results show that the MVT (MVO) core set favours breeds with a high (low) within breed kinship that are not related to other breeds. Following this, the MVT core set method suggests conserving breeds that show a large difference in the respective population mean of a hypothetical quantitative trait. This maximises the speed of achieving selection response for this hypothetical selection direction. Additionally, bootstrap based methods for the estimation of the breed's contribution to the core sets were introduced, substantially improving the accuracy of the contribution estimates.

Abstract A multi-locus QTL mapping method is presented, which combines linkage and linkage disequilibrium (LD) information and uses multitrait data. The method assumed a putative QTL at the midpoint of each marker bracket. Whether the putative QTL had an effect or not was sampled using Markov chain Monte Carlo (MCMC) methods. The method was tested in dairy cattle data on chromosome 14 where the DGAT1 gene was known to be segregating. The DGAT1 gene was mapped to a region of 0.04 cM, and the effects of the gene were accurately estimated. The fitting of multiple QTL gave a much sharper indication of the QTL position than a single QTL model using multitrait data, probably because the multi-locus QTL mapping reduced the carry over effect of the large DGAT1 gene to adjacent putative QTL positions. This suggests that the method could detect secondary QTL that would, in single point analyses, remain hidden under the broad peak of the dominant QTL. However, no indications for a second QTL affecting dairy traits were found on chromosome 14.

Abstract The ordinary-, penalized-, and bootstrap t-test, least squares and best linear unbiased prediction were compared for their false discovery rates (FDR), i.e. the fraction of falsely discovered genes, which was empirically estimated in a duplicate of the data set. The bootstrap-t-test yielded up to 80% lower FDRs than the alternative statistics, and its FDR was always as good as or better than any of the alternatives. Generally, the predicted FDR from the bootstrapped P-values agreed well with their empirical estimates, except when the number of mRNA samples is smaller than 16. In a cancer data set, the bootstrap-t-test discovered 200 differentially regulated genes at a FDR of 2.6%, and in a knock-out gene expression experiment 10 genes were discovered at a FDR of 3.2%. It is argued that, in the case of microarray data, control of the FDR takes sufficient account of the multiple testing, whilst being less stringent than Bonferoni-type multiple testing corrections. Extensions of the bootstrap simulations to more complicated test-statistics are discussed.

Missense and truncating variants in the X-chromosome-linked CLCN4 gene, resulting in reduced or complete loss-of-function (LOF) of the encoded chloride/proton exchanger ClC-4, were recently demonstrated to cause a neurocognitive phenotype in both males and females. Through international clinical matchmaking and interrogation of public variant databases we assembled a database of 90 rare CLCN4 missense variants in 90 families: 41 unique and 18 recurrent variants in 49 families. For 43 families, including 22 males and 33 females, we collated detailed clinical and segregation data. To confirm causality of variants and to obtain insight into disease mechanisms, we investigated the effect on electrophysiological properties of 59 of the variants in Xenopus oocytes using extended voltage and pH ranges. Detailed analyses revealed new pathophysiological mechanisms: 25% (15/59) of variants demonstrated LOF, characterized by a shift of the voltage-dependent activation to more positive voltages, and nine variants resulted in a toxic gain-of-function, associated with a disrupted gate allowing inward transport at negative voltages. Functional results were not always in line with in silico pathogenicity scores, highlighting the complexity of pathogenicity assessment for accurate genetic counselling. The complex neurocognitive and psychiatric manifestations of this condition, and hitherto under-recognized impacts on growth, gastrointestinal function, and motor control are discussed. Including published cases, we summarize features in 122 individuals from 67 families with CLCN4-related neurodevelopmental condition and suggest future research directions with the aim of improving the integrated care for individuals with this diagnosis.

Abstract We studied different genetic models and evaluation systems to select against a genetic disease with additive, recessive or polygenic inheritance in genetic conservation schemes. When using optimum contribution selection with a restriction on the rate of inbreeding (ΔF) to select against a disease allele, selection directly on DNA-genotypes is, as expected, the most efficient strategy. Selection for BLUP or segregation analysis breeding value estimates both need 1–2 generations more to halve the frequency of the disease allele, while these methods do not require knowledge of the disease mutation at the DNA level. BLUP and segregation analysis methods were equally efficient when selecting against a disease with single gene or complex polygene inheritance, i.e. knowledge about the mode of inheritance of the disease was not needed for efficient selection against the disease. Smaller schemes or schemes with a more stringent restriction on ΔF needed more generations to halve the frequency of the disease alleles or the fraction of diseased animals. Optimum contribution selection maintained ΔF at its predefined level, even when selection of females was at random. It is argued that in the investigated small conservation schemes with selection against a genetic defect, control of ΔF is very important.

Abstract The quantitative assessment of genetic diversity within and between populations is important for decision making in genetic conservation plans. In this paper we define the genetic diversity of a set of populations, S, as the maximum genetic variance that can be obtained in a random mating population that is bred from the set of populations S. First we calculated the relative contribution of populations to a core set of populations in which the overlap of genetic diversity was minimised. This implies that the mean kinship in the core set should be minimal. The above definition of diversity differs from Weitzman diversity in that it attempts to conserve the founder population (and thus minimises the loss of alleles), whereas Weitzman diversity favours the conservation of many inbred lines. The former is preferred in species where inbred lines suffer from inbreeding depression. The application of the method is illustrated by an example involving 45 Dutch poultry breeds. The calculations used were easy to implement and not computer intensive. The method gave a ranking of breeds according to their contributions to genetic diversity. Losses in genetic diversity ranged from 2.1% to 4.5% for different subsets relative to the entire set of breeds, while the loss of founder genome equivalents ranged from 22.9% to 39.3%.

Abstract Minimum coancestry mating with a maximum of one offspring per mating pair (MC1) is compared with random mating schemes for populations with overlapping generations. Optimum contribution selection is used, whereby ΔF is restricted. For schemes with ΔF restricted to 0.25% per year, 256 animals born per year and heritability of 0.25, genetic gain increased with 18% compared with random mating. The effect of MC1 on genetic gain decreased for larger schemes and schemes with a less stringent restriction on inbreeding. Breeding schemes hardly changed when omitting the iteration on the generation interval to find an optimum distribution of parents over age-classes, which saves computer time, but inbreeding and genetic merit fluctuated more before the schemes had reached a steady-state. When bulls were progeny tested, these progeny tested bulls were selected instead of the young bulls, which led to increased generation intervals, increased selection intensity of bulls and increased genetic gain (35% compared to a scheme without progeny testing for random mating). The effect of MC1 decreased for schemes with progeny testing. MC1 mating increased genetic gain from 11–18% for overlapping and 1–4% for discrete generations, when comparing schemes with similar genetic gain and size.

Abstract The prediction of identity by descent (IBD) probabilities is essential for all methods that map quantitative trait loci (QTL). The IBD probabilities may be predicted from marker genotypes and/or pedigree information. Here, a method is presented that predicts IBD probabilities at a given chromosomal location given data on a haplotype of markers spanning that position. The method is based on a simplification of the coalescence process, and assumes that the number of generations since the base population and effective population size is known, although effective size may be estimated from the data. The probability that two gametes are IBD at a particular locus increases as the number of markers surrounding the locus with identical alleles increases. This effect is more pronounced when effective population size is high. Hence as effective population size increases, the IBD probabilities become more sensitive to the marker data which should favour finer scale mapping of the QTL. The IBD probability prediction method was developed for the situation where the pedigree of the animals was unknown (i.e. all information came from the marker genotypes), and the situation where, say T, generations of unknown pedigree are followed by some generations where pedigree and marker genotypes are known.

Abstract The effect of non-random mating on genetic response was compared for populations with discrete generations. Mating followed a selection step where the average coancestry of selected animals was constrained, while genetic response was maximised. Minimum coancestry (MC), Minimum coancestry with a maximum of one offspring per mating pair (MC1) and Minimum variance of the relationships of offspring (MVRO) mating schemes resulted in a delay in inbreeding of about two generations compared with Random, Random factorial and Compensatory mating. In these breeding schemes where selection constrains the rate of inbreeding, ΔF, the improved family structure due to non-random mating increased genetic response. For schemes with ΔF constrained to 1.0% and 100 selection candidates, genetic response was 22% higher for the MC1 and MVRO schemes compared with Random mating schemes. For schemes with a less stringent constraint on ΔF or more selection candidates, the superiority of the MC1 and MVRO schemes was smaller (5–6%). In general, MC1 seemed to be the preferred mating method, since it almost always yielded the highest genetic response. MC1 mainly achieved these high genetic responses by avoiding extreme relationships among the offspring, i.e. fullsib offspring are avoided, and by making the contributions of ancestors to offspring more equal by mating least related animals.

Chronic low back pain (CLBP) is one of the most common chronic musculoskeletal disorders worldwide. Guidelines recommend exercise therapy (ET) in CLBP management, but more research is needed to investigate specific ET modalities and their underlying mechanisms. The primary goal of this study is to evaluate the short-term and long-term effectiveness of a time-contingent individualised high-intensity training (HIT) protocol on disability compared with a time-contingent moderate-intensity training (MIT) as used in usual care, in persons with severely disabling CLBP. Additionally, the effectiveness on central effects, the added value of prolonged training at home and technology support, and the cost-effectiveness are evaluated. In this randomised controlled trial, CLBP patients will be randomly divided into three groups of 56 participants. Group 1, ‘TechnoHIT’, receives HIT with technology-support in the home-phase. Group 2, ‘HIT’, receives HIT without technology support. Group 3, ‘MIT’, receives MIT, reflecting training intensity as used in usual care. The primary outcome is patient-reported disability, measured by the Modified Oswestry Disability Index. Secondary outcomes include quantitative sensory testing, psychosocial factors, broad physical fitness, quality of life, cost-effectiveness, adherence and usability of technology. Trial registration number NCT06491121.

Non-culprit coronary artery lesions are commonly present in patients presenting with an acute coronary syndrome (ACS). Additional stenting of non-culprit lesions in addition to the culprit lesion intends to prevent secondary events caused by these lesions. At the same time, multiple trials have demonstrated the potential of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors in reducing plaque size and changing plaque composition of non-culprit lesions. Whether intensive low-density lipoprotein cholesterol (LDL-C) reduction with PCSK9 inhibitor evolocumab improves non-culprit vessel hemodynamics, reduces the risk of plaque rupture of important non-culprit lesions, and might obviate the need for additional stenting has not been investigated. The “Functional Improvement of non‐infarcT related coronary artery stenosis by Extensive LDL‐C Reduction with a PCSK9 Antibody” (FITTER) trial is a multi-center, randomized, double-blind, placebo-controlled clinical trial for patients presenting with ACS and multivessel disease (MVD). After treatment of the culprit lesion, fractional flow reserve (FFR) is performed in non-culprit vessels amenable for percutaneous coronary intervention (PCI). Coronary intervention in patients with hemodynamically important non-critical lesions (FFR: 0.67–0.85) is staged after baseline imaging using near-infrared spectroscopy (NIRS) and intravascular ultrasound (IVUS). Eligible patients are randomized and treated for 12 weeks with either evolocumab or placebo, in addition to high-intensity statin therapy. Follow-up angiography with repeat FFR and IVUS-NIRS is scheduled at 12 weeks. Staged PCI is performed at the operator's discretion.The FITTER trial is the first study to evaluate the effect of maximal LDL-C reduction by the PCSK9 inhibitor evolocumab on invasively measured FFR, plaque size, and plaque composition in hemodynamically important non-culprit lesions, during a treatment period of just 12 weeks after an ACS. Currently, all patients have been included (August 2023) and data analysis is ongoing. Trial registration number: clinicaltrials.gov NCT04141579.

In deze bijdrage combineren we kwantitatieve en kwalitatieve inzichten over virtueel teamwerk in het accountantsberoep. We illustreren dat hoewel meer virtueel werk de prestaties van controleteams kan verminderen, de controlekwaliteit als hoog wordt ervaren – ook bij een toegenomen mate van virtueel teamwerk.1 Verder tonen we dat virtueel teamwerk niet intrinsiek goed of slecht is, maar om een afweging vraagt tussen flexibiliteit en structurele nadelen, zoals beperkte leermomenten. Ook tonen we hoe accountantskantoren optimale omstandigheden kunnen scheppen voor virtuele auditteams door het bevorderen van leergedrag en empowerend leiderschap.

Abstract Background Since the very beginning of genomic selection, researchers investigated methods that improved upon SNP-BLUP (single nucleotide polymorphism best linear unbiased prediction). SNP-BLUP gives equal weight to all SNPs, whereas it is expected that many SNPs are not near causal variants and thus do not have substantial effects. A recent approach to remedy this is to use genome-wide association study (GWAS) findings and increase the weights of GWAS-top-SNPs in genomic predictions. Here, we employ a genome-wide approach to integrate GWAS results into genomic prediction, called GWABLUP. Results GWABLUP consists of the following steps: (1) performing a GWAS in the training data which results in likelihood ratios; (2) smoothing the likelihood ratios over the SNPs; (3) combining the smoothed likelihood ratio with the prior probability of SNPs having non-zero effects, which yields the posterior probability of the SNPs; (4) calculating a weighted genomic relationship matrix using the posterior probabilities as weights; and (5) performing genomic prediction using the weighted genomic relationship matrix. Using high-density genotypes and milk, fat, protein and somatic cell count phenotypes on dairy cows, GWABLUP was compared to GBLUP, GBLUP (topSNPs) with extra weights for GWAS top-SNPs, and BayesGC, i.e. a Bayesian variable selection model. The GWAS resulted in six, five, four, and three genome-wide significant peaks for milk, fat and protein yield and somatic cell count, respectively. GWABLUP genomic predictions were 10, 6, 7 and 1% more reliable than those of GBLUP for milk, fat and protein yield and somatic cell count, respectively. It was also more reliable than GBLUP (topSNPs) for all four traits, and more reliable than BayesGC for three of the traits. Although GWABLUP showed a tendency towards inflation bias for three of the traits, this was not statistically significant. In a multitrait analysis, GWABLUP yielded the highest accuracy for two of the traits. However, for SCC, which was relatively unrelated to the yield traits, including yield trait GWAS-results reduced the reliability compared to a single trait analysis. Conclusions GWABLUP uses GWAS results to differentially weigh all the SNPs in a weighted GBLUP genomic prediction analysis. GWABLUP yielded up to 10% and 13% more reliable genomic predictions than GBLUP for single and multitrait analyses, respectively. Extension of GWABLUP to single-step analyses is straightforward.

Relevance. Coaches and athletes across a variety of sports commonly perform abdominal exercises to promote core strength and endurance. However, the precise influence of abdominal strength and endurance on cycling performance remains elusive. Purpose. Determine whether abdominal fatigue affects anaerobic sprint and aerobic time- trial (TT) cycling performance. Methods. Twenty-three untrained young adults (age: 19,2 ± 1,0 years, height: 170,4 ± 7,5 cm, and weight: 74,5 ± 14,1 kg) participated in this study. Twelve of the participants completed two Wingate anaerobic power tests on a Monark 834 E ergometer set at 7,5 % of body mass and the remaining 11 participants completed two 3,2 km cycling TTs on an Expresso S3U virtual reality bike; tests were separated by 96 hours. All participants performed abdominal crunches to fatigue prior to the second test. Dependent t-tests were used to assess differences between the cycling trials for the two groups. Results. Abdominal muscle fatigue decreased mean anaerobic power (Pre: 486,75 vs. Post: 408,83 Watts (W, p < 0,001), increased the rate of fatigue (Pre: 42,01 vs. Post: 50,32 %, p = 0,004), and tended to decrease peak anaerobic power (Pre: 643,17 vs. Post: 607,27 W, p = 0,088). However, abdominal muscle fatigue did not affect TT mean power (Pre: 228,18 vs. Post: 220,09 W, p = 0,127) or TT performance (Pre: 382,7 vs. Post: 388,0 seconds, p = 0,222). Conclusion. Abdominal fatigue negatively affects anaerobic cycling performance in untrained young adults. Future studies should evaluate the impact of abdominal fatigue on cycling performance in trained cyclists.

Background The EXPLORE (Evaluating Xience and Left Ventricular Function in PCI on Occlusions After STEMI) trial was the first and only randomized trial investigating chronic total occlusion (CTO) percutaneous coronary intervention (PCI) early after primary PCI for ST‐segment–elevation myocardial infarction, compared with medical therapy for the CTO. We performed a 10‐year follow‐up of EXPLORE to investigate long‐term safety and clinical impact of CTO PCI after ST‐segment–elevation myocardial infarction, compared with no‐CTO PCI. Methods and Results In EXPLORE, 302 patients post‐ST‐segment–elevation myocardial infarction with concurrent CTO were randomized to CTO PCI within ≈1 week or no‐CTO PCI. We performed an extended clinical follow‐up for the primary end point of major adverse cardiac events, consisting of cardiovascular death, coronary artery bypass grafting, or myocardial infarction. Secondary end points included all‐cause death, angina, and dyspnea. Median follow‐up was 10 years (interquartile range, 8–11 years). The primary end point occurred in 25% of patients with CTO PCI and in 24% of patients with no‐CTO PCI (hazard ratio [HR], 1.11 [95% CI, 0.70–1.76]). Cardiovascular mortality was higher in the CTO PCI group (HR, 2.09 [95% CI, 1.10–2.50]), but all‐cause death was similar (HR, 1.53 [95% CI, 0.93–2.50]). Dyspnea relief was more frequent after CTO PCI (83% versus 65%, P=0.005), with no significant difference in angina. Conclusions This 10‐year follow‐up of patients post‐ST‐segment–elevation myocardial infarction randomized to CTO PCI or no‐CTO PCI demonstrated no clinical benefit of CTO PCI in major adverse cardiac events or overall mortality. However, CTO PCI was associated with a higher cardiovascular mortality compared with no‐CTO PCI. Our long‐term data support a careful weighing of effective symptom relief against an elevated cardiovascular mortality risk in CTO PCI decisions. Registration URL: https://www.trialregister.nl; Unique identifier: NTR1108.