1. |
- Abelev, Betty, et al.
(författare)
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Long-range angular correlations on the near and away side in p-Pb collisions at root S-NN=5.02 TeV
- 2013
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 719:1-3, s. 29-41
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Tidskriftsartikel (refereegranskat)abstract
- Angular correlations between charged trigger and associated particles are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV for transverse momentum ranges within 0.5 < P-T,P-assoc < P-T,P-trig < 4 GeV/c. The correlations are measured over two units of pseudorapidity and full azimuthal angle in different intervals of event multiplicity, and expressed as associated yield per trigger particle. Two long-range ridge-like structures, one on the near side and one on the away side, are observed when the per-trigger yield obtained in low-multiplicity events is subtracted from the one in high-multiplicity events. The excess on the near-side is qualitatively similar to that recently reported by the CMS Collaboration, while the excess on the away-side is reported for the first time. The two-ridge structure projected onto azimuthal angle is quantified with the second and third Fourier coefficients as well as by near-side and away-side yields and widths. The yields on the near side and on the away side are equal within the uncertainties for all studied event multiplicity and p(T) bins, and the widths show no significant evolution with event multiplicity or p(T). These findings suggest that the near-side ridge is accompanied by an essentially identical away-side ridge. (c) 2013 CERN. Published by Elsevier B.V. All rights reserved.
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2. |
- Abelev, Betty, et al.
(författare)
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Measurement of prompt J/psi and beauty hadron production cross sections at mid-rapidity in pp collisions at root s=7 TeV
- 2012
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; :11
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Tidskriftsartikel (refereegranskat)abstract
- The ALICE experiment at the LHC has studied J/psi production at mid-rapidity in pp collisions at root s = 7 TeV through its electron pair decay on a data sample corresponding to an integrated luminosity L-int = 5.6 nb(-1). The fraction of J/psi from the decay of long-lived beauty hadrons was determined for J/psi candidates with transverse momentum p(t) > 1,3 GeV/c and rapidity vertical bar y vertical bar < 0.9. The cross section for prompt J/psi mesons, i.e. directly produced J/psi and prompt decays of heavier charmonium states such as the psi(2S) and chi(c) resonances, is sigma(prompt J/psi) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 8.3 +/- 0.8(stat.) +/- 1.1 (syst.)(-1.4)(+1.5) (syst. pol.) mu b. The cross section for the production of b-hadrons decaying to J/psi with p(t) > 1.3 GeV/c and vertical bar y vertical bar < 0.9 is a sigma(J/psi <- hB) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 1.46 +/- 0.38 (stat.)(-0.32)(+0.26) (syst.) mu b. The results are compared to QCD model predictions. The shape of the p(t) and y distributions of b-quarks predicted by perturbative QCD model calculations are used to extrapolate the measured cross section to derive the b (b) over bar pair total cross section and d sigma/dy at mid-rapidity.
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3. |
- Abelev, Betty, et al.
(författare)
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Underlying Event measurements in pp collisions at root s=0.9 and 7 TeV with the ALICE experiment at the LHC
- 2012
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; :7
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Tidskriftsartikel (refereegranskat)abstract
- We present measurements of Underlying Event observables in pp collisions at root s = 0 : 9 and 7 TeV. The analysis is performed as a function of the highest charged-particle transverse momentum p(T),L-T in the event. Different regions are defined with respect to the azimuthal direction of the leading (highest transverse momentum) track: Toward, Transverse and Away. The Toward and Away regions collect the fragmentation products of the hardest partonic interaction. The Transverse region is expected to be most sensitive to the Underlying Event activity. The study is performed with charged particles above three different p(T) thresholds: 0.15, 0.5 and 1.0 GeV/c. In the Transverse region we observe an increase in the multiplicity of a factor 2-3 between the lower and higher collision energies, depending on the track p(T) threshold considered. Data are compared to PYTHIA 6.4, PYTHIA 8.1 and PHOJET. On average, all models considered underestimate the multiplicity and summed p(T) in the Transverse region by about 10-30%.
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4. |
- Jonell, Malin, 1983-
(författare)
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Kind of turquoise : Effects of seafood eco-certification and sustainable consumption
- 2016
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Aquaculture and fisheries hold promise for supplying a growing world population with healthy food produced without undermining the earth’s carrying capacity. However, just as livestock production and agriculture, seafood production can have negative environmental impacts and if a continuous or even increased supply is to be guaranteed, the pressure on affected ecosystems needs to be limited. Due in part to a perceived failure of other governance mechanisms in improving the environmental performance of the sector, a large number of voluntary market based standards for farmed and wild caught seafood have been developed. Nonetheless, the knowledge base on the extent to which implementation leads to environmental improvements remains limited. Moreover, the role of consumers in driving demand for eco-labeled seafood is presently an under-researched area. This thesis aims at reducing this knowledge gap through an examination of the potential environmental effectiveness of aquaculture eco-certification and internal, psychological variables predicted to be of importance for sustainable seafood consumption. Put differently, what is the potential of eco-certification in greening the blue revolution and fuel ‘turquoise growth’, and how can consumer demand be spurred?In Paper I, the role of eco-certification in improving the growing aquaculture sector at large was explored. Results showed that environmental effects at global scale likely will be limited due to e.g. partial coverage of species groups and environmental impacts, and a lack of focus on Asian markets and consumers. In Paper II the environmental performance of eco-certified and non-certified mangrove-integrated shrimp farms in Vietnam was compared by using Life Cycle Assessment and put in relation to conventional, more intensive farms. While there was no substantial difference between certified and non-certified farms in terms of environmental impacts, emissions of greenhouse gasses were higher for mangrove-integrated than conventional farms due to mangrove land use change. The results from Paper III demonstrated that the body of literature investigating ecological effects of seafood eco-certification is limited. ‘Spatially explicit ecosystem service information’ (ES-information) on e.g. key ecosystem services and biodiversity in a given area is suggested to have potential to improve sustainability standards. Taking guidance from the pro-environmental behavior literature, consumers in Stockholm, Sweden were consulted on awareness of and attitudes towards eco-labeled seafood (Paper IV-V). Two variables, concern for environmental impacts and knowledge about seafood eco-labels were the best predictors for stated eco-labeled seafood purchasing. Moreover, there seemed to be a misalignment between consumers’ expectations on eco-labeled food in general and certification requirements for eco-labeled seafood.From this set of findings, a number of improvements of current seafood eco-certification are suggested. First, include an LCA-perspective in standards to a higher degree than presently done and provide readily available ES-information in the implementation and evaluation phase of certification. Second, introduce standardized mechanisms for capturing potential environmental improvements over time. And finally, stimulate demand by targeting Asian consumers and markets as well as strengthen consumer eco-label awareness and emotional involvement.
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5. |
- Love, David C., et al.
(författare)
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Emerging COVID-19 impacts, responses, and lessons for building resilience in the seafood system
- 2021
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Ingår i: Global food security. - : Elsevier BV. - 2211-9124. ; 28
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Tidskriftsartikel (refereegranskat)abstract
- The COVID-19 pandemic and subsequent lockdowns are creating health and economic crises that threaten food and nutrition security. The seafood sector provides important sources of nutrition and employment, especially in low-income countries, and is highly globalized allowing shocks to propagate. We studied COVID-19-related disruptions, impacts, and responses to the seafood sector from January through May 2020, using a food system resilience ‘action cycle’ framework as a guide. We find that some supply chains, market segments, companies, small-scale actors and civil society have shown initial signs of greater resilience than others. COVID-19 has also highlighted the vulnerability of certain groups working in- or dependent on the seafood sector. We discuss early coping and adaptive responses combined with lessons from past shocks that could be considered when building resilience in the sector. We end with strategic research needs to support learning from COVID-19 impacts and responses.
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6. |
- Tlusty, Michael, et al.
(författare)
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Reframing the sustainable seafood narrative
- 2019
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Ingår i: Global Environmental Change. - : Elsevier Ltd. - 0959-3780 .- 1872-9495. ; 59
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Tidskriftsartikel (refereegranskat)abstract
- The dominant sustainable seafood narrative is one where developed world markets catalyze practice improvements by fisheries and aquaculture producers that enhance ocean health. The narrow framing of seafood sustainability in terms of aquaculture or fisheries management and ocean health has contributed to the omission of these important food production systems from the discussion on global food system sustainability. This omission is problematic. Seafood makes critical contributions to food and nutrition security, particularly in low income countries, and is often a more sustainable and nutrient rich source of animal sourced-food than terrestrial meat production. We argue that to maximize the positive contributions that seafood can make to sustainable food systems, the conventional narratives that prioritize seafood's role in promoting ‘ocean health’ need to be reframed and cover a broader set of environmental and social dimensions of sustainability. The focus of the narrative also needs to move from a producer-centric to a ‘whole chain’ perspective that includes greater inclusion of the later stages with a focus on food waste, by-product utilization and consumption. Moreover, seafood should not be treated as a single aggregated item in sustainability assessments. Rather, it should be recognized as a highly diverse set of foods, with variable environmental impacts, edible yield rates and nutritional profiles. Clarifying discussions around seafood will help to deepen the integration of fisheries and aquaculture into the global agenda on sustainable food production, trade and consumption, and assist governments, private sector actors, NGOs and academics alike in identifying where improvements can be made.
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