Repair of oxidatively damaged guanine in Saccharomyces cerevisiae by an alternative pathway

AbstractBackground: Transversion mutations are caused by 8-oxoguanine (OG), a DNA lesion produced by the spontaneous oxidation of guanine nucleotides, which mis-pairs with adenine during replication. Resistance to this mutagenic threat is mediated by the GO system, the components of which are functionally conserved in bacteria and mammals. To date, only one of three GO system components has been identified in the budding yeast Saccharomyces cerevisiae, namely the OG:C-specific glycosylase/lyase yOgg1. Furthermore, S. cerevisiae has been reported to contain a unique glycosylase/lyase activity, yOgg2, which excises OG residues opposite adenines. Paradoxically, according to the currently accepted model, yOgg2 activity should increase the mutagenicity of OG lesions. Here we report the isolation of yOgg2 and the elucidation of its role in oxidative mutagenesis.Results: Borohydride-dependent cross-linking using an OG-containing oligonucleotide substrate led to the isolation of yOgg1 and a second protein, Ntg1, which had previously been shown to process oxidized pyrimidines in DNA. We demonstrate that Ntg1 has OG-specific glycosylase/lyase activity indistinguishable from that of yOgg2. Targeted disruption of the NTG1 gene resulted in complete loss of yOgg2 activity and yeast lacking NTG1 had an elevated rate of A:T to C:G transversions.Conclusions: The Ntg1 and yOgg2 activities are encoded by a single gene. We propose that yOgg2 has evolved to process OG:A mis-pairs that have arisen through mis-incorporation of 8-oxo-dGTP during replication. Thus, the GO system in S. cerevisiae is fundamentally distinct from that in bacteria and mammals

What do young athletes implicitly understand about psychological skills?

One reason sport psychologists teach psychological skills is to enhance performance in sport; but the value of psychological skills for young athletes is questionable because of the qualitative and quantitative differences between children and adults in their understanding of abstract concepts such as mental skills. To teach these skills effectively to young athletes, sport psychologists need to appreciate what young athletes implicitly understand about such skills because maturational (e.g., cognitive, social) and environmental (e.g., coaches) factors can influence the progressive development of children and youth. In the present qualitative study, we explored young athletes’ (aged 10–15 years) understanding of four basic psychological skills: goal setting, mental imagery, self-talk, and relaxation. Young athletes (n = 118: 75 males and 43 females) completed an open-ended questionnaire to report their understanding of these four basic psychological skills. Compared with the older youth athletes, the younger youth athletes were less able to explain the meaning of each psychological skill. Goal setting and mental imagery were better understood than self-talk and relaxation. Based on these findings, sport psychologists should consider adapting interventions and psychoeducational programs to match young athletes’ age and developmental level

Cardiorespiratory fitness is associated with physical literacy in a large sample of Canadian children aged 8 to 12 years

Background The associations between cardiorespiratory fitness (CRF) and physical literacy in children are largely unknown. The aim of this study was to assess the relationships between CRF, measured using the 20-m shuttle run test (20mSRT), and components of physical literacy among Canadian children aged 8–12 years. Methods A total of 9393 (49.9% girls) children, with a mean (SD) age of 10.1 (±1.2) years, from a cross-sectional surveillance study were included for this analysis. The SRT was evaluated using a standardized 15 m or 20 m protocol. All 15 m SRTs were converted to 20mSRT values using a standardized formula. The four domains of physical literacy (Physical Competence, Daily Behaviour, Motivation and Confidence, and Knowledge and Understanding) were measured using the Canadian Assessment of Physical Literacy. Tertiles were identified for 20mSRT laps, representing low, medium, and high CRF for each age and gender group. Cohen’s d was used to calculate the effect size between the low and high CRF groups. Results CRF was strongly and favourably associated with all components of physical literacy among school-aged Canadian children. The effect size between low and high CRF tertile groups was large for the Physical Competence domain (Cohen’s d range: 1.11–1.94) across age and gender groups, followed by moderate to large effect sizes for Motivation and Confidence (Cohen’s d range: 0.54–1.18), small to moderate effect sizes for Daily Behaviour (Cohen’s d range: 0.25–0.81), and marginal to moderate effect sizes for Knowledge and Understanding (Cohen’s d range: 0.08–0.70). Conclusions This study identified strong favourable associations between CRF and physical literacy and its constituent components in children aged 8–12 years. Future research should investigate the sensitivity and specificity of the 20mSRT in screening those with low physical literacy levels

Search for Narrow Diphoton Resonances and for gamma-gamma+W/Z Signatures in p\bar p Collisions at sqrt(s)=1.8 TeV

We present results of searches for diphoton resonances produced both inclusively and also in association with a vector boson (W or Z) using 100 pb^{-1} of p\bar p collisions using the CDF detector. We set upper limits on the product of cross section times branching ratio for both p\bar p\to\gamma\gamma + X and p\bar p\to\gamma\gamma + W/Z. Comparing the inclusive production to the expectations from heavy sgoldstinos we derive limits on the supersymmetry-breaking scale sqrt{F} in the TeV range, depending on the sgoldstino mass and the choice of other parameters. Also, using a NLO prediction for the associated production of a Higgs boson with a W or Z boson, we set an upper limit on the branching ratio for H\to\gamma\gamma. Finally, we set a lower limit on the mass of a `bosophilic' Higgs boson (e.g. one which couples only to \gamma, W, and Z$ bosons with standard model couplings) of 82 GeV/c^2 at 95% confidence level.Comment: 30 pages, 11 figure

Search for New Particles Decaying to Dijets at CDF

We have used 106 pb^-1 of data collected with the Collider Detector at Fermilab to search for new particles decaying to dijets. We exclude at the 95% confidence level models containing the following new particles: axigluons and flavor universal colorons with mass between 200 and 980 GeV/c, excited quarks with mass between 80 and 570 GeV/c^2 and between 580 and 760 GeV/c^2, color octet technirhos with mass between 260 and 480 GeV/c^2, W' bosons with mass between 300 and 420 GeV/c^2, and E_6 diquarks with mass between 290 and 420 GeV/c^2.Comment: 18 pages, 4 figures, 1 table. Submitted to Physical Review D Rapid Communications. Postscript file of paper is also available at http://www-cdf.fnal.gov/physics/pub97/cdf3276_dijet_search_prd_rc.p

Uncertainty and Narratives of the Future. A Theoretical Framework for Contemporary Fertility

Explanations for fertility decisions based on structural constraints—such as labor, housing condition, or income—do not account for the contemporary fertility downturn faced by many countries in Europe. In this paper, we posit that the rise of uncertainty is central for understanding contemporary fertility dynamics. We propose a theoretical framework (the Narrative Framework) for the study of fertility decisions under uncertain conditions based on expectations, imaginaries and narratives. Relying on the idea of future–oriented action, we argue that uncertainty needs to be conceptualized and operationalized taking into account that people use works of imagination, producing their own narrative of the future. Narratives of the future are potent driving forces helping people to act according to or despite uncertainty. We present the different elements of the Narrative Framework and address its causal validity. We conclude by highlighting the advantages of taking into account the narratives of the future in fertility research

Search for narrow resonances in dilepton mass spectra in proton-proton collisions at root s=13 TeV and combination with 8 TeV data

Peer reviewe

Observation of Charge-Dependent Azimuthal Correlations in p-Pb Collisions and Its Implication for the Search for the Chiral Magnetic Effect

Peer reviewe

Search for R-parity violating supersymmetry with displaced vertices in proton-proton collisions at root s=8 TeV

Peer reviewe