Repeatability of ovulation rate and its relationship with litter size in four sheep breeds

International audienc

Artificial Intelligence in Brain Tumour Surgery—An Emerging Paradigm

Artificial intelligence (AI) platforms have the potential to cause a paradigm shift in brain tumour surgery. Brain tumour surgery augmented with AI can result in safer and more effective treatment. In this review article, we explore the current and future role of AI in patients undergoing brain tumour surgery, including aiding diagnosis, optimising the surgical plan, providing support during the operation, and better predicting the prognosis. Finally, we discuss barriers to the successful clinical implementation, the ethical concerns, and we provide our perspective on how the field could be advanced

Heterozygote Advantage for Fecundity

Heterozygote advantage, or overdominance, remains a popular and persuasive explanation for the maintenance of genetic variation in natural populations in the face of selection. However, despite being first proposed more than 80 years ago, there remain few examples that fit the criteria for heterozygote advantage, all of which are associated with disease resistance and are maintained only in the presence of disease or other gene-by-environment interaction. Here we report five new examples of heterozygote advantage, based around polymorphisms in the BMP15 and GDF9 genes that affect female fecundity in domesticated sheep and are not reliant on disease for their maintenance. Five separate mutations in these members of the transforming growth factor β (TGFβ) superfamily give phenotypes with fitness differentials characteristic of heterozygous advantage. In each case, one copy of the mutant allele increases ovulation rate, and ultimately litter size per ewe lambing, relative to the wildtype. However, homozygous ewes inheriting mutant alleles from both parents have impaired oocyte development and maturation, which results in small undeveloped ovaries and infertility. Using data collected over many years on ovulation rates, litter size, and lambing rates, we have calculated the equilibrium solution for each of these polymorphisms using standard population genetic theory. The predicted equilibrium frequencies obtained for these mutant alleles range from 0.11 to 0.23, which are amongst the highest yet reported for a polymorphism maintained by heterozygote advantage. These are amongst the most frequent and compelling examples of heterozygote advantage yet described and the first documented examples of heterozygote advantage that are not reliant on a disease interaction for their maintenance

Prognostic Factors for Distress After Genetic Testing for Hereditary Cancer

The psychological impact of an unfavorable genetic test result for counselees at risk for hereditary cancer seems to be limited: only 10-20 % of counselees have psychological problems after testing positive for a known familial mutation. The objective of this study was to find prognostic factors that can predict which counselees are most likely to develop psychological problems after presymptomatic genetic testing. Counselees with a 50 % risk of BRCA1/2 or Lynch syndrome completed questionnaires at three time-points: after receiving a written invitation for a genetic counseling intake (T1), 2-3 days after receiving their DNA test result (T2), and 4-6 weeks later (T3). The psychological impact of the genetic test result was examined shortly and 4-6 weeks after learning their test result. Subsequently, the influence of various potentially prognostic factors on psychological impact were examined in the whole group. Data from 165 counselees were analyzed. Counselees with an unfavorable outcome did not have more emotional distress, but showed significantly more cancer worries 4-6 weeks after learning their test result. Prognostic factors for cancer worries after genetic testing were pre-existing cancer worries, being single, a high risk perception of getting cancer, and an unfavorable test result. Emotional distress was best predicted by pre-existing cancer worries and pre-existing emotional distress. The psychological impact of an unfavorable genetic test result appears considerable if it is measured as "worries about cancer." Genetic counselors should provide additional guidance to counselees with many cancer worries, emotional distress, a high risk perception or a weak social network

Low back pain status in elite and semi-elite Australian football codes: a cross-sectional survey of football (soccer), Australian rules, rugby league, rugby union and non-athletic controls

<p>Abstract</p> <p>Background</p> <p>Our understanding of the effects of football code participation on low back pain (LBP) is limited. It is unclear whether LBP is more prevalent in athletic populations or differs between levels of competition. Thus it was the aim of this study to document and compare the prevalence, intensity, quality and frequency of LBP between elite and semi-elite male Australian football code participants and a non-athletic group.</p> <p>Methods</p> <p>A cross-sectional survey of elite and semi-elite male Australian football code participants and a non-athletic group was performed. Participants completed a self-reported questionnaire incorporating the Quadruple Visual Analogue Scale (QVAS) and McGill Pain Questionnaire (short form) (MPQ-SF), along with additional questions adapted from an Australian epidemiological study. Respondents were 271 elite players (mean age 23.3, range 17–39), 360 semi-elite players (mean age 23.8, range 16–46) and 148 non-athletic controls (mean age 23.9, range 18–39).</p> <p>Results</p> <p>Groups were matched for age (p = 0.42) and experienced the same age of first onset LBP (p = 0.40). A significant linear increase in LBP from the non-athletic group, to the semi-elite and elite groups for the QVAS and the MPQ-SF was evident (p < 0.001). Elite subjects were more likely to experience more frequent (daily or weekly OR 1.77, 95% CI 1.29–2.42) and severe LBP (discomforting and greater OR 1.75, 95% CI 1.29–2.38).</p> <p>Conclusion</p> <p>Foolers in Australia have significantly more severe and frequent LBP than a non-athletic group and this escalates with level of competition.</p

Lifetime environmental tobacco smoke exposure and the risk of chronic obstructive pulmonary disease

BACKGROUND: Exposure to environmental tobacco smoke (ETS), which contains potent respiratory irritants, may lead to chronic airway inflammation and obstruction. Although ETS exposure appears to cause asthma in children and adults, its role in causing COPD has received limited attention in epidemiologic studies. METHODS: Using data from a population-based sample of 2,113 U.S. adults aged 55 to 75 years, we examined the association between lifetime ETS exposure and the risk of developing COPD. Participants were recruited from all 48 contiguous U.S. states by random digit dialing. Lifetime ETS exposure was ascertained by structured telephone interview. We used a standard epidemiologic approach to define COPD based on a self-reported physician diagnosis of chronic bronchitis, emphysema, or COPD. RESULTS: Higher cumulative lifetime home and work exposure were associated with a greater risk of COPD. The highest quartile of lifetime home ETS exposure was associated with a greater risk of COPD, controlling for age, sex, race, personal smoking history, educational attainment, marital status, and occupational exposure to vapors, gas, dusts, or fumes during the longest held job (OR 1.55; 95% CI 1.09 to 2.21). The highest quartile of lifetime workplace ETS exposure was also related to a greater risk of COPD (OR 1.36; 95% CI 1.002 to 1.84). The population attributable fraction was 11% for the highest quartile of home ETS exposure and 7% for work exposure. CONCLUSION: ETS exposure may be an important cause of COPD. Consequently, public policies aimed at preventing public smoking may reduce the burden of COPD-related death and disability, both by reducing direct smoking and ETS exposure

Adaptive Value of Phenological Traits in Stressful Environments: Predictions Based on Seed Production and Laboratory Natural Selection

Phenological traits often show variation within and among natural populations of annual plants. Nevertheless, the adaptive value of post-anthesis traits is seldom tested. In this study, we estimated the adaptive values of pre- and post-anthesis traits in two stressful environments (water stress and interspecific competition), using the selfing annual species Arabidopsis thaliana. By estimating seed production and by performing laboratory natural selection (LNS), we assessed the strength and nature (directional, disruptive and stabilizing) of selection acting on phenological traits in A. thaliana under the two tested stress conditions, each with four intensities. Both the type of stress and its intensity affected the strength and nature of selection, as did genetic constraints among phenological traits. Under water stress, both experimental approaches demonstrated directional selection for a shorter life cycle, although bolting time imposes a genetic constraint on the length of the interval between bolting and anthesis. Under interspecific competition, results from the two experimental approaches showed discrepancies. Estimation of seed production predicted directional selection toward early pre-anthesis traits and long post-anthesis periods. In contrast, the LNS approach suggested neutrality for all phenological traits. This study opens questions on adaptation in complex natural environment where many selective pressures act simultaneously