756 research outputs found

    Assessing Maternal Energetic Allocation During Lactation for the Weddell Seal Using Photogrammetric Techniques

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    Life history theory predicts that allocation of resources to reproduction varies across an individual’s life as one’s reproductive value changes with age. As individuals reach late life and residual reproductive value declines, they should increase the proportion of energy allocated to reproduction at a cost to future survival or reproduction, this is referred to as terminal investment. Characteristics of Weddell seal life history make this marine-mammal a model organism for investigating terminal investment. Previous research from this population has indicated that pups of older females exhibit a higher growth rate from birth to weaning compared to pups from mothers of prime and young ages. We offer three competing hypotheses that may explain observed increased growth rates of pups born to older mothers and hypothesize that this finding may be a result of terminal allocation. Maternal volume measurements obtained with photogrammetric techniques will be used to explore variation in maternal energetic allocation during lactation. A simple linear regression of maternal volume against maternal measured mass was used to obtain the prediction regression equation. We found a very strong relationship between measured masses and those estimated from our predictive equation (Adjusted R2:0.8958, n=31). Estimated mass loss of mothers and apparent mass conversion efficiency from mother to pup over the course of lactation will be used to assess support for competing hypotheses. Results from this study may improve our understanding of life history theory and highlight sources of variation in population vital rates

    Temporal correlations among demographic parameters are ubiquitous but highly variable across species

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    Temporal correlations among demographic parameters can strongly influence population dynamics. Our empirical knowledge, however, is very limited regarding the direction and the magnitude of these correlations and how they vary among demographic parameters and species’ life histories. Here, we use long-term demographic data from 15 bird and mammal species with contrasting pace of life to quantify correlation patterns among five key demographic parameters: juvenile and adult survival, reproductive probability, reproductive success and productivity. Correlations among demographic parameters were ubiquitous, more frequently positive than negative, but strongly differed across species. Correlations did not markedly change along the slow-fast continuum of life histories, suggesting that they were more strongly driven by ecological than evolutionary factors. As positive temporal demographic correlations decrease the mean of the long-run population growth rate, the common practice of ignoring temporal correlations in population models could lead to the underestimation of extinction risks in most species

    2018 Research & Innovation Day Program

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    A one day showcase of applied research, social innovation, scholarship projects and activities.https://first.fanshawec.ca/cri_cripublications/1005/thumbnail.jp

    The misasandry myth: An inaccurate stereotype about feminists' attitudes toward men

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    In six studies, we examined the accuracy and underpinnings of the damaging stereotype that feminists harbor negative attitudes toward men. In Study 1 (n = 1,664), feminist and nonfeminist women displayed similarly positive attitudes toward men. Study 2 (n = 3,892) replicated these results in non-WEIRD countries and among male participants. Study 3 (n = 198) extended them to implicit attitudes. Investigating the mechanisms underlying feminists’ actual and perceived attitudes, Studies 4 (n = 2,092) and 5 (nationally representative UK sample, n = 1,953) showed that feminists (vs. nonfeminists) perceived men as more threatening, but also more similar, to women. Participants also underestimated feminists’ warmth toward men, an error associated with hostile sexism and a misperception that feminists see men and women as dissimilar. Random-effects meta-analyses of all data (Study 6, n = 9,799) showed that feminists’ attitudes toward men were positive in absolute terms and did not differ significantly from nonfeminists'. An important comparative benchmark was established in Study 6, which showed that feminist women's attitudes toward men were no more negative than men's attitudes toward men. We term the focal stereotype the misandry myth in light of the evidence that it is false and widespread, and discuss its implications for the movement

    MUSiC : a model-unspecific search for new physics in proton-proton collisions at root s=13TeV

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    Results of the Model Unspecific Search in CMS (MUSiC), using proton-proton collision data recorded at the LHC at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1), are presented. The MUSiC analysis searches for anomalies that could be signatures of physics beyond the standard model. The analysis is based on the comparison of observed data with the standard model prediction, as determined from simulation, in several hundred final states and multiple kinematic distributions. Events containing at least one electron or muon are classified based on their final state topology, and an automated search algorithm surveys the observed data for deviations from the prediction. The sensitivity of the search is validated using multiple methods. No significant deviations from the predictions have been observed. For a wide range of final state topologies, agreement is found between the data and the standard model simulation. This analysis complements dedicated search analyses by significantly expanding the range of final states covered using a model independent approach with the largest data set to date to probe phase space regions beyond the reach of previous general searches.Peer reviewe

    Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV

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    A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe

    Measurement of prompt open-charm production cross sections in proton-proton collisions at root s=13 TeV

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    The production cross sections for prompt open-charm mesons in proton-proton collisions at a center-of-mass energy of 13TeV are reported. The measurement is performed using a data sample collected by the CMS experiment corresponding to an integrated luminosity of 29 nb(-1). The differential production cross sections of the D*(+/-), D-+/-, and D-0 ((D) over bar (0)) mesons are presented in ranges of transverse momentum and pseudorapidity 4 < p(T) < 100 GeV and vertical bar eta vertical bar < 2.1, respectively. The results are compared to several theoretical calculations and to previous measurements.Peer reviewe

    Combined searches for the production of supersymmetric top quark partners in proton-proton collisions at root s=13 TeV

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    A combination of searches for top squark pair production using proton-proton collision data at a center-of-mass energy of 13 TeV at the CERN LHC, corresponding to an integrated luminosity of 137 fb(-1) collected by the CMS experiment, is presented. Signatures with at least 2 jets and large missing transverse momentum are categorized into events with 0, 1, or 2 leptons. New results for regions of parameter space where the kinematical properties of top squark pair production and top quark pair production are very similar are presented. Depending on themodel, the combined result excludes a top squarkmass up to 1325 GeV for amassless neutralino, and a neutralinomass up to 700 GeV for a top squarkmass of 1150 GeV. Top squarks with masses from 145 to 295 GeV, for neutralino masses from 0 to 100 GeV, with a mass difference between the top squark and the neutralino in a window of 30 GeV around the mass of the top quark, are excluded for the first time with CMS data. The results of theses searches are also interpreted in an alternative signal model of dark matter production via a spin-0 mediator in association with a top quark pair. Upper limits are set on the cross section for mediator particle masses of up to 420 GeV

    Probing effective field theory operators in the associated production of top quarks with a Z boson in multilepton final states at root s=13 TeV

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