20 research outputs found
Protein and energy nutrition of marine gadoids, Atlantic cod (Gadus morhua L.) and haddock (Melanogrammus aeglefinus L.)
No full text Primary goals of this thesis were to: 1) examine the in vivo digestion of macronutrients from conventional or alternative feed ingredients used in practical diets of juvenile gadoids (Atlantic cod and haddock), 2) document growth potential of fish at the juvenile grower phase given varying levels of dietary protein and energy and 3) assess the potential of in vitro pH-Stat methods for rapid screening protein quality of feed ingredients, specifically for gadoids. All primary research questions were linked to and built upon one another with the goal of gaining a better understanding of protein and energy utilization of juvenile grower phase gadoids. Studies showed that cod and haddock have a high capacity to utilize a wide range of dietary feed ingredients, such as fish meals, zooplankton meal, soybean products (meal, concentrate and isolate) and wheat gluten meal. New dietary formulations for gadoids may also utilize pulse meals, corn gluten meal, canola protein concentrate and crab meal. Digestibility data in this thesis is currently the only research that examined both in vivo and in vitro macronutrient digestibility of a large number and wide range of individual ingredients, specifically for gadoids. This is essential to gain new knowledge on protein and energy utilization as well as for least-cost ration formulations and effective substitution of ingredients into new formulations. Data has demonstrated a dietary digestible protein/digestible energy (DP/DE)ratio of 30 g DP/MJ DE is required for gadoids during the juvenile phase (in vitro closed-system pH-Stat assay for rapid screening protein quality of test ingredients that is ‘species-specific’ to gadoids. It is demonstrated that in vitro results generally reflected results obtained through conventional in vivo protein digestibility methods. Studies resulted in the first generation of a ‘gadoid-specific’ proteolytic enzyme extraction method and in vitro closed-system pH-Stat assay which may be useful to investigate protein digestion, absorption and metabolism of gadoids and further development of their feeds. </p
Search for invisible decays of Higgs bosons in the vector boson fusion and associated ZH production modes
No full textA search for invisible decays of Higgs bosons is performed using the vector boson fusion and associated ZH production modes. In the ZH mode, the Z boson is required to decay to a pair of charged leptons or a bb quark pair. The searches use the 8  TeV pp collision dataset collected by the CMS detector at the LHC, corresponding to an integrated luminosity of up to 19.7  fb-1. Certain channels include data from 7  TeV collisions corresponding to an integrated luminosity of 4.9  fb-1. The searches are sensitive to non-standard-model invisible decays of the recently observed Higgs boson, as well as additional Higgs bosons with similar production modes and large invisible branching fractions. In all channels, the observed data are consistent with the expected standard model backgrounds. Limits are set on the production cross section times invisible branching fraction, as a function of the Higgs boson mass, for the vector boson fusion and ZH production modes. By combining all channels, and assuming standard model Higgs boson cross sections and acceptances, the observed (expected) upper limit on the invisible branching fraction at mH = 125   GeV is found to be 0.58 (0.44) at 95 % confidence level. We interpret this limit in terms of a Higgs-portal model of dark matter interactions
Performance of electron reconstruction and selection with the CMS detector in proton-proton collisions at sqrt(s) = 8 TeV
No full textA preprint version is available at arXiv:1502.02701v2 [physics.ins-det], https://arxiv.org/abs/1502.02701v2 . Comments: Replaced with published version. Added journal reference and DOI. Report number: CMS-EGM-13-001, CERN-PH-EP-2015-004,The performance and strategies used in electron reconstruction and selection at CMS are presented based on data corresponding to an integrated luminosity of 19.7 inverse femtobarns, collected in proton-proton collisions at sqrt(s) = 8 TeV at the CERN LHC. The paper focuses on prompt isolated electrons with transverse momenta ranging from about 5 to a few 100 GeV. A detailed description is given of the algorithms used to cluster energy in the electromagnetic calorimeter and to reconstruct electron trajectories in the tracker. The electron momentum is estimated by combining the energy measurement in the calorimeter with the momentum measurement in the tracker. Benchmark selection criteria are presented, and their performances assessed using Z, Upsilon, and J/psi decays into electron-positron pairs. The spectra of the observables relevant to electron reconstruction and selection as well as their global efficiencies are well reproduced by Monte Carlo simulations. The momentum scale is calibrated with an uncertainty smaller than 0.3%. The momentum resolution for electrons produced in Z boson decays ranges from 1.7 to 4.5%, depending on electron pseudorapidity and energy loss through bremsstrahlung in the detector material
Search for the production of dark matter in association with top-quark pairs in the single-lepton final state in proton-proton collisions at sqrt(s) = 8 TeV
No full textA preprint version of the article is available at arXiv:1504.03198v2 [hep-ex], https://arxiv.org/abs/1504.03198v2 . Report number: CMS-B2G-14-004, CERN-PH-EP-2015-087.A search is presented for particle dark matter produced in association with a pair of top quarks in pp collisions at a centre-of-mass energy of √s = 8 TeV. The data were collected with the CMS detector at the LHC and correspond to an integrated luminosity of 19.7 fb^{−1}. This search requires the presence of one lepton, multiple jets, and large missing transverse energy. No excess of events is found above the SM expectation, and upper limits are derived on the production cross section. Interpreting the findings in the context of a scalar contact interaction between fermionic dark matter particles and top quarks, lower limits on the interaction scale are set. These limits are also interpreted in terms of the dark matter-nucleon scattering cross sections for the spin-independent scalar operator and they complement direct searches for dark matter particles in the low mass region
Search for decays of stopped long-lived particles produced in proton-proton collisions at sqrt(s) = 8 TeV
No full textA preprint version of the article is available at arXiv:1501.05603v2 [hep-ex], https://arxiv.org/abs/1501.05603v2 . Comments: Replaced with published version. Added journal reference and DOI. Report number: CMS-EXO-12-036, CERN-PH-EP-2015-002.A search has been performed for long-lived particles that could have come to rest within the CMS detector, using the time intervals between LHC beam crossings. The existence of such particles could be deduced from observation of their decays via energy deposits in the CMS calorimeter appearing at times that are well separated from any proton–proton collisions. Using a data set corresponding to an integrated luminosity of 18.6-1 of 8 TeV proton–proton collisions, and a search interval corresponding to 281 h of trigger livetime, 10 events are observed, with a background prediction of 132-2.5+3.6 events. Limits are presented at 95 % confidence level on gluino and top squark production, for over 13 orders of magnitude in the mean proper lifetime of the stopped particle. Assuming a cloud model of R-hadron interactions, a gluino with mass ≲1000 GeV and a top squark with mass ≲525 GeV are excluded, for lifetimes between 1 μs and 1000s. These results are the most stringent constraints on stopped particles to date.SCOAP3
Study of W boson production in pPb collisions at sqrt(s[NN]) = 5.02 TeV
No full textSubmitted to Phys. Lett. B ; see paper for full list of authorsInternational audienceThe first study of W boson production in pPb collisions is presented, for bosons decaying to a muon or electron, and a neutrino. The measurements are based on a data sample corresponding to an integrated luminosity of 34.6 inverse nanobarns at a nucleon-nucleon centre-of-mass energy of sqrt(s[NN]) = 5.02 TeV, collected by the CMS experiment. The W boson differential cross sections, lepton charge asymmetry, and forward-backward asymmetries are measured for leptons of transverse momentum exceeding 25 GeV, and as a function of the lepton pseudorapidity in the abs(eta[lab]) < 2.4 range. Deviations from the expectations based on currently available parton distribution functions are observed, showing the need for including W boson data in nuclear parton distribution global fits
Community radio in Ireland: building community, participation and multi-flow communication
No full textThe core aims of community radio stations foreground the principle of participation by the people in the communication process. Community radio stations broadcast to build the communities which they serve. Six Irish community radio stations are studied to examine the implementation of these aims. The study asks how community radio stations
• try to build the communities in which they broadcast?
• promote multi-flow communication?
• facilitate participation?
Three main frameworks are employed in the analysis of the research. The ideal construct of community is understood to be formed on the four bases of place, relationship, time and belief. Enzensberger’s dichotomy of repressive and emancipatory media is built upon to examine how multi-flow communication can be facilitated. A hierarchical model which identifies seven possible levels of participation in media is employed.
The key finding of the study is that it is the facilitation of participation which enables community radio stations to successfully implement their core aims. Irish community radio stations seek to build their communities. Many of them adopt a community development approach to their work. Irish community radio stations facilitate the human right to communicate. They do this by providing a communications link for their communities. This provides the basis for communication to flow in many directions rather than in the traditional, one-way flow of mass media generally. Irish community radio stations frequently target specific segments of their communities which enables the provision of multi, micro-public spheres.
Reflections on the observed practice of the community radio stations studied, when linked to the conceptual frameworks outlined, provide useful norms to inform the emerging communication theory of community media
Search for narrow high-mass resonances in proton-proton collisions at sqrt(s) = 8 TeV decaying to a Z and a Higgs boson
No full textA preprint version is available at arXiv:1502.04994v2 [hep-ex], https://arxiv.org/abs/1502.04994v2. Comments: Replaced with published version. Added journal reference and DOI. Report number: CMS-EXO-13-007, CERN-PH-EP-2015-01.A search for a narrow, high-mass resonance decaying into Z and Higgs (H) bosons is presented. The final state studied consists of a merged jet pair and a τ pair resulting from the decays of Z and H bosons, respectively. The analysis is based on a data sample of proton-proton collisions at a center-of-mass energy of 8 TeV, collected with the CMS experiment in 2012, and corresponding to an integrated luminosity of 19.7 fb-1. In the resonance mass range of interest, which extends from 0.8 to 2.5 TeV, the Z and H bosons are produced with large momenta, which implies that the final products of the two quarks or the two τ leptons must be detected within a small angular interval. From a combination of all possible decay modes of the τ leptons, production cross sections in a range between 0.9 and 27.8 fb are excluded at 95% confidence level, depending on the resonance mass.SCOAP3
