342 research outputs found

    Take it or leave it for something better? Responses to fair offers in ultimatum bargaining

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    We investigated if responders accept a 50-50 split in a modified version of the ultimatum game, in which rejection yields a higher payoff (€7) than accepting the equal offer (€5). Therefore, the decision to accept the 50-50 split in this modified ultimatum game cannot be perceived as a self-interest act, as opposed to the standard game, in which acceptance may reflect resignation in the knowledge that the equal split is the best one can expect. A substantial proportion of responders accepts the equal split in this modified game (Study 1), which clearly establishes egalitarian preferences. Further studies show that the willingness to accept is not an artifact of indifference towards the extra payoff (Study 2), but reflects true concerns for proposers’ outcomes (Study 3)

    Quantification of Cre-mediated recombination by a novel strategy reveals a stable extra-chromosomal deletion-circle in mice

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    <p>Abstract</p> <p>Background</p> <p>Inducible conditional knockout animals are widely used to get insight in the function of genes and the pathogenesis of human diseases. These models frequently rely on Cre-mediated recombination of sequences flanked by Lox-P sites. To understand the consequences of gene disruption, it is essential to know the efficiency of the recombination process.</p> <p>Results</p> <p>Here, we describe a modification of the multiplex ligation-dependent probe amplification (MLPA), called extension-MLPA (eMLPA), which enables quantification of relatively small differences in DNA that are a consequence of Cre-mediated recombination. eMLPA, here applied on an inducible <it>Pkd1 </it>conditional deletion mouse model, simultaneously measures both the reduction of the floxed allele and the increase of the deletion allele in a single reaction thereby minimizing any type of experimental variation. Interestingly, with this method we were also able to observe the presence of the excised DNA fragment. This extra-chromosomal deletion-circle was detectable up to 5 months after activation of Cre.</p> <p>Conclusion</p> <p>eMLPA is a novel strategy which easily can be applied to measure the Cre-mediated recombination efficiency in each experimental case with high accuracy. In addition the fate of the deletion-circle can be followed simultaneously.</p

    In Vitro and In Vivo Evaluation of Infestation Deterrents Against Lice

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    The human head louse is a cosmopolitan ectoparasite and frequently infests many people, particularly school-age children. Due to widespread pyrethroid resistance and the lack of efficient resistance management, there has been a considerable interest in the protection of uninfested people and prevention of reinfestation by disrupting lice transfer. In this study, two nonclinical model systems (in vitro and in vivo) were used to determine the efficacy of the infestation deterrents, Elimax lotion and Elimax shampoo, against human head lice or poultry chewing lice, respectively. With in vitro assessments, female head lice exhibited significantly higher avoidance responses to hair tufts treated with either of the test formulations, which led to significantly higher ovipositional avoidance when compared with female lice on control hair tufts. Additionally, both formulations were determined to be competent infestation deterrents in a competitive avoidance test in the presence of a known attractant (head louse feces extract). In in vivo assessments using a previously validated poultry model, Elimax shampoo was determined to be an efficacious deterrent against poultry chewing lice within Menopon spp. and Menacanthus spp

    NMR structure of μ-conotoxin GIIIC : leucine 18 induces local repacking of the N-terminus resulting in reduced NaV channel potency

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    mu-Conotoxins are potent and highly specific peptide blockers of voltage-gated sodium channels. In this study, the solution structure of mu-conotoxin GIIIC was determined using 2D NMR spectroscopy and simulated annealing calculations. Despite high sequence similarity, GIIIC adopts a three-dimensional structure that differs from the previously observed conformation of mu-conotoxins GIIIA and GIIIB due to the presence of a bulky, non-polar leucine residue at position 18. The side chain of L18 is oriented towards the core of the molecule and consequently the N-terminus is re-modeled and located closer to L18. The functional characterization of GIIIC defines it as a canonical mu-conotoxin that displays substantial selectivity towards skeletal muscle sodium channels (Na-V), albeit with similar to 2.5-fold lower potency than GIIIA. GIIIC exhibited a lower potency of inhibition of Na(V)1.4 channels, but the same Na-V selectivity profile when compared to GIIIA. These observations suggest that single amino acid differences that significantly affect the structure of the peptide do in fact alter its functional properties. Our work highlights the importance of structural factors, beyond the disulfide pattern and electrostatic interactions, in the understanding of the functional properties of bioactive peptides. The latter thus needs to be considered when designing analogues for further applications

    Multiple cardiac biomarkers to improve prediction of cardiovascular events:Findings from the Generation Scotland Scottish Family Health Study

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    Background: Many studies have investigated whether single cardiac biomarkers improve cardiovascular risk prediction for primary prevention but whether a combined approach could further improve risk prediction is unclear. We aimed to test a sex-specific combined cardiac biomarker approach for cardiovascular risk prediction. Methods: In the Generation Scotland Scottish Family Health Study, N-terminal pro-B-type natriuretic peptide (NT-proBNP), growth differentiation factor-15 (GDF-15), cardiac troponin I (cTnI), cardiac troponin T (cTnT), and C-reactive protein (CRP) were measured in stored serum using automated immunoassays. Sex-specific Cox models that included SCORE2 risk factors evaluated addition of single and combined biomarkers for prediction of major adverse cardiovascular events (MACE). Combined biomarker models were compared to a baseline model that included SCORE2 factors.Results: The study population comprised 18,383 individuals (58.9% women, median age of 48 years [25th-75th percentile, 35-58 years]). During the median follow up of 11.6 (25th-75th percentile, 10.8-13.0) years, MACE occurred in 942 (5.1%) individuals. The greatest increase in discrimination with addition of individual biomarkers to base model was for women GDF-15 and for men NT-proBNP (change in c-index: +0.010 for women and +0.005 for men). For women, combined biomarker models that included GDF-15 and NT-proBNP (+0.012) or GDF-15 and cTnI (+0.013), but not CRP or cTnT, further improved discrimination. For men, combined biomarker models that included NT-proBNP and GDF-15 (+0.007), NT-proBNP and cTnI (+0.006), or NT-proBNP and CRP (+0.008), but not cTnT, further improved discrimination. Conclusions: A combined biomarker approach, particularly the use of GDF-15, NT-proBNP and cTnI, further refined cardiovascular risk estimates.<br/

    Influence of age on the diagnosis of myocardial infarction

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    The 99th centile of cardiac troponin, derived from a healthy reference population, is recommended as the diagnostic threshold for myocardial infarction, but troponin concentrations are strongly influenced by age. Our aim was to assess the diagnostic performance of cardiac troponin in older patients presenting with suspected myocardial infarction. METHODS: In a secondary analysis of a multicenter trial of consecutive patients with suspected myocardial infarction, we assessed the diagnostic accuracy of high-sensitivity cardiac troponin I at presentation for the diagnosis of type 1, type 2, or type 4b myocardial infarction across 3 age groups (<50, 50–74, and ≥75 years) using guideline-recommended sex-specific and age-adjusted 99th centile thresholds. RESULTS: In 46 435 consecutive patients aged 18 to 108 years (mean, 61±17 years), 5216 (11%) had a diagnosis of myocardial infarction. In patients <50 (n=12 379), 50 to 74 (n=22 380), and ≥75 (n=11 676) years, the sensitivity of the guideline-recommended threshold was similar at 79.2% (95% CI, 75.5–82.9), 80.6% (95% CI, 79.2–82.1), and 81.6% (95% CI, 79.8–83.2), respectively. The specificity decreased with advancing age from 98.3% (95% CI, 98.1–98.5) to 95.5% (95% CI, 95.2–95.8), and 82.6% (95% CI, 81.9–83.4). The use of age-adjusted 99th centile thresholds improved the specificity (91.3% [90.8%–91.9%] versus 82.6% [95% CI, 81.9%–83.4%]) and positive predictive value (59.3% [57.0%–61.5%] versus 51.5% [49.9%–53.3%]) for myocardial infarction in patients ≥75 years but failed to prevent the decrease in either parameter with increasing age and resulted in a marked reduction in sensitivity compared with the use of the guideline-recommended threshold (55.9% [53.6%–57.9%] versus 81.6% [79.8%–83.3%]. CONCLUSIONS: Age alters the diagnostic performance of cardiac troponin, with reduced specificity and positive predictive value in older patients when applying the guideline-recommended or age-adjusted 99th centiles. Individualized diagnostic approaches rather than the adjustment of binary thresholds are needed in an aging population

    Single-cell Analysis of the Neonatal Immune System Across the Gestational Age Continuum

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    Although most causes of death and morbidity in premature infants are related to immune maladaptation, the premature immune system remains poorly understood. We provide a comprehensive single-cell depiction of the neonatal immune system at birth across the spectrum of viable gestational age (GA), ranging from 25 weeks to term. A mass cytometry immunoassay interrogated all major immune cell subsets, including signaling activity and responsiveness to stimulation. An elastic net model described the relationship between GA and immunome (R=0.85, p=8.75e-14), and unsupervised clustering highlighted previously unrecognized GA-dependent immune dynamics, including decreasing basal MAP-kinase/NFkB signaling in antigen presenting cells; increasing responsiveness of cytotoxic lymphocytes to interferon-a; and decreasing frequency of regulatory and invariant T cells, including NKT cells and MAIT cells. Knowledge gained from the analysis of the neonatal immune landscape across GA provides a mechanistic framework to understand the unique susceptibility of preterm infants to both hyper-inflammatory diseases and infections

    Complex Evolutionary History With Extensive Ancestral Gene Flow in an African Primate Radiation

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    Understanding the drivers of speciation is fundamental in evolutionary biology, and recent studies highlight hybridization as an important evolutionary force. Using whole-genome sequencing data from 22 species of guenons (tribe Cercopithecini), one of the world's largest primate radiations, we show that rampant gene flow characterizes their evolutionary history and identify ancient hybridization across deeply divergent lineages that differ in ecology, morphology, and karyotypes. Some hybridization events resulted in mitochondrial introgression between distant lineages, likely facilitated by cointrogression of coadapted nuclear variants. Although the genomic landscapes of introgression were largely lineage specific, we found that genes with immune functions were overrepresented in introgressing regions, in line with adaptive introgression, whereas genes involved in pigmentation and morphology may contribute to reproductive isolation. In line with reports from other systems that hybridization might facilitate diversification, we find that some of the most species-rich guenon clades are of admixed origin. This study provides important insights into the prevalence, role, and outcomes of ancestral hybridization in a large mammalian radiation

    Implementation of high-sensitivity cardiac troponin and risk of myocardial infarction or death at 5 years: stepped-wedge, cluster-randomised controlled trial

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    AbstractObjective: To evaluate the impact of implementing a high-sensitivity cardiac troponin I assay on long-term outcomes in patients with suspected acute coronary syndromeDesign: Secondary observational analysis of a stepped-wedge cluster-randomised controlled trial.Setting: Ten secondary and tertiary care centresParticipants: Consecutive patients with suspected acute coronary syndrome (n=48,282; 47% women) were included in this trial. Myocardial injury was defined as any high-sensitivity cardiac troponin I concentration &gt;99th centile of 16 ng/L in women and 34 ng/L in men.Intervention: Hospital sites were randomly allocated to early (n=5 hospitals) or late (n=5 hospitals) implementation of a high-sensitivity cardiac troponin I assay with sex-specific diagnostic thresholds.Main Outcome Measures: Subsequent myocardial infarction or death at 5 years.Results: Overall, 10,360 patients had cardiac troponin concentrations greater than the 99th centile of whom 1,771 (17%) were reclassified by the high-sensitivity assay. The 5-year incidence of subsequent myocardial infarction or death before and after implementation of the high-sensitivity assay was 29% (5,588/18,978) versus 26% (7,591/29,304), respectively, in all patients (adjusted hazard ratio [aHR] 0.97 [95% CI 0.93 to 1.01]), and 63% (456/720) versus 54% (567/1,051) in those reclassified by the high-sensitivity assay (aHR 0.82 [0.72-0.94]). Following implementation, a reduction in subsequent myocardial infarction or death was observed in patients with non-ischemic myocardial injury (aHR 0·83 [0·75-0·91]), but not in those with type 1 or type 2 myocardial infarction (aHR 0·92 [0·83-1·01] and 0·98 [0·84-1·14]).Conclusions: In patients with suspected acute coronary syndrome, implementation of a high-sensitivity cardiac troponin assay reduced the risk of subsequent myocardial infarction or death at 5 years in those reclassified by the high-sensitivity assay. Improvements in outcome were greatest in patients with non-ischemic myocardial injury suggesting a broader benefit beyond the identification of myocardial infarction.<br/
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