| 1. |
- Aad, G., et al.
(författare)
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Measurement of the polarisation of W bosons produced in top-quark decays using dilepton events at √s=13 TeV with the ATLAS experiment
- 2023
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 843
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Tidskriftsartikel (refereegranskat)abstract
- measurement of the polarisation of W bosons produced in top-quark decays is presented, using proton–proton collision data at a centre-of-mass energy of √s=13 TeV. The data were collected by the ATLAS detector at the Large Hadron Collider and correspond to an integrated luminosity of 139 fb−1. The measurement is performed selecting events decaying into final states with two charged leptons (electrons or muons) and at least two b-tagged jets. The polarisation is extracted from the differential cross-section distribution of the cosθ* variable, where θ* is the angle between the momentum direction of the charged lepton from the W boson decay and the reversed momentum direction of the b-quark from the top-quark decay, both calculated in the W boson rest frame. Parton-level results, corrected for the detector acceptance and resolution, are presented for the cosθ* angle. The measured fractions of longitudinal, left- and right-handed polarisation states are found to be f0=0.684±0.005(stat.)±0.014(syst.), fL=0.318±0.003(stat.)±0.008(syst.) and fR=−0.002±0.002(stat.)±0.014(syst.), in agreement with the Standard Model prediction.
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| 2. |
- Andrean, Stefio Y., 1991-, et al.
(författare)
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Probing the CP nature of the top–Higgs Yukawa coupling in tt¯H??¯? and tH events with H→bb¯?→??¯ decays using the ATLAS detector at the LHC
- 2024
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Ingår i: Physics Letters B. - : Elsevier B.V.. - 0370-2693 .- 1873-2445. ; 849
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Tidskriftsartikel (refereegranskat)abstract
- The CP properties of the coupling between the Higgs boson and the top quark are investigated using 139 fb−1 of proton–proton collision data recorded by the ATLAS experiment at the LHC at a centre-of-mass energy of s√=13?=13 TeV. The CP structure of the top quark–Higgs boson Yukawa coupling is probed in events with a Higgs boson decaying into a pair of b-quarks and produced in association with either a pair of top quarks, tt¯H??¯?, or a single top quark, tH. Events containing one or two electrons or muons are used for the measurement. Multivariate techniques are used to select regions enriched in tt¯H??¯? and tH events, where dedicated CP-sensitive observables are exploited. In an extension of the Standard Model (SM) with a CP-odd admixture in the top–Higgs Yukawa coupling, the mixing angle between CP-even and CP-odd couplings is measured to be α=11∘+52∘−73∘?=11−73∘∘+52∘, compatible with the SM prediction corresponding to α=0?=0.
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| 3. |
- Berglund, Sara, et al.
(författare)
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Cardiorenal function and survival in in-hospital cardiac arrest : A nationwide study of 22,819 cases
- 2022
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Ingår i: Resuscitation. - : Elsevier BV. - 0300-9572 .- 1873-1570. ; 172, s. 9-16
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Tidskriftsartikel (refereegranskat)abstract
- Background: We studied the association between cardiorenal function and survival, neurological outcome and trends in survival after in-hospital Methods: We included cases aged 18 years in the Swedish Cardiopulmonary Resuscitation Registry during 2008 to 2020. The CKD-EPI equation was used to calculate estimated glomerular filtration rate (eGFR). A history of heart failure was defined according to contemporary guideline criteria. Logistic regression was used to study survival. Neurological outcome was assessed using cerebral performance category (CPC). Results: We studied 22,819 patients with IHCA. The 30-day survival was 19.3%, 16.6%, 22.5%, 28.8%, 39.3%, 44.8% and 38.4% in cases with eGFR < 15, 15-29, 30-44, 45-59, 60-89, 90-130 and 130-150 ml/min/1.73 m2, respectively. All eGFR levels below and above 90 ml/min/1.73 m2 were associated with increased mortality. Probability of survival at 30 days was 62% lower in cases with eGFR < 15 ml/min/1.73 m2, compared with normal kidney function. At every level of eGFR, presence of heart failure increased mortality markedly; patients without heart failure displayed higher mortality only at eGFR below 30 ml/min/1.73 m2. Among survivors with eGFR < 15 ml/min/1.73 m2, good neurological outcome was noted in 87.2%. Survival increased in most groups over time, but most for those with eGFR < 15 ml/min/1.73 m2, and least for those with normal eGFR. Conclusions: All eGFR levels below and above normal range are associated with increased mortality and this association is modified by the presence of heart failure. Neurological outcome is good in the majority of cases, across kidney function levels and survival is increasing.
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| 4. |
- Boudreault, Louis-Etienne, et al.
(författare)
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A LiDAR method of canopy structure retrieval for wind modeling of heterogeneous forests
- 2015
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Ingår i: Agricultural and Forest Meteorology. - : Elsevier BV. - 1873-2240 .- 0168-1923. ; 201, s. 86-97
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Tidskriftsartikel (refereegranskat)abstract
- The difficulty of obtaining accurate information about the canopy structure is a current limitation towards higher accuracy in numerical predictions of the wind field in forested terrain. The canopy structure in computational fluid dynamics is specified through the frontal area density and this information is required for each grid point in the three-dimensional computational domain. By using raw data from aerial LiDAR scans together with the Beer-Lambert law, we propose and test a method to calculate and grid highly variable and realistic frontal area density input. An extensive comparison with ground-based measurements of the vertically summed frontal area density (or plant area index) and tree height was used to optimize the method, both in terms of plant area index magnitude and spatial variability. The resolution of the scans was in general low (<2.5 reflections m(-2)). A decrease of the resolution produced an increasing systematic underestimation of the spatially averaged tree height, whereas the mean plant area index remained insensitive. The gridded frontal area density and terrain elevation were used at the lower boundary of wind simulations in a 5 km x 5 km area of a forested site. The results of the flow simulations were compared to wind measurements using a vertical array of sonic anemometers. A good correlation was found for the mean wind speed of two contrasting wind directions with different influences from the upstream forest. The results also predicted a high variability on the horizontal and vertical mean wind speed, in close correlation with the canopy structure. The method is a promising tool for several computational fluid dynamics applications requiring accurate predictions of the near-surface wind field. (C) 2014 The Authors. Published by Elsevier B.V.
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| 5. |
- Marquer, Laurent, et al.
(författare)
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Holocene changes in vegetation composition in northern Europe: why quantitative pollen-based vegetation reconstructions matter
- 2014
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Ingår i: Quaternary Science Reviews. - : Elsevier BV. - 0277-3791 .- 1873-457X. ; 90, s. 199-216
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Tidskriftsartikel (refereegranskat)abstract
- We present pollen-based reconstructions of the spatio-temporal dynamics of northern European regional vegetation abundance through the Holocene. We apply the Regional Estimates of VEgetation Abundance from Large Sites (REVEALS) model using fossil pollen records from eighteen sites within five modern biomes in the region. The eighteen sites are classified into four time-trajectory types on the basis of principal components analysis of both the REVEALS-based vegetation estimates (RVs) and the pollen percentage (PPs). The four trajectory types are more clearly separated for RVs than PPs. Further, the timing of major Holocene shifts, rates of compositional change, and diversity indices (turnover and evenness) differ between RVs and PPs. The differences are due to the reduction by REVEALS of biases in fossil pollen assemblages caused by different basin size, and inter-taxonomic differences in pollen productivity and dispersal properties. For example, in comparison to the PPs, the RVs show an earlier increase in Corylus and Ulmus in the early-Holocene and a more pronounced increase in grassland and deforested areas since the mid-Holocene. The results suggest that the influence of deforestation and agricultural activities on plant composition and abundance from Neolithic times was stronger than previously inferred from PPs. Relative to PPs, RVs show a more rapid compositional change, a largest decrease in turnover, and less variable evenness in most of northern Europe since 5200 cal yr BP. All these changes are primarily related to the strong impact of human activities on the vegetation. This study demonstrates that RV-based estimates of diversity indices, timing of shifts, and rates of change in reconstructed vegetation provide new insights into the timing and magnitude of major human distribution on Holocene regional, vegetation, feature that are critical in the assessment of human impact on vegetation, land-cover, biodiversity, and climate in the past. (C) Elsevier Ltd.All tights reserved.
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| 6. |
- Marquer, Laurent, et al.
(författare)
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Quantifying the effects of land use and climate on Holocene vegetation in Europe
- 2017
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Ingår i: Quaternary Science Reviews. - : Pergamon Press. - 0277-3791 .- 1873-457X. ; 171, s. 20-37
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Tidskriftsartikel (refereegranskat)abstract
- Early agriculture can be detected in palaeovegetation records, but quantification of the relative importance of climate and land use in influencing regional vegetation composition since the onset of agriculture is a topic that is rarely addressed. We present a novel approach that combines pollen-based REVEALS estimates of plant cover with climate, anthropogenic land-cover and dynamic vegetation modelling results. This is used to quantify the relative impacts of land use and climate on Holocene vegetation at a sub-continental scale, i.e. northern and western Europe north of the Alps. We use redundancy analysis and variation partitioning to quantify the percentage of variation in vegetation composition explained by the climate and land-use variables, and Monte Carlo permutation tests to assess the statistical significance of each variable. We further use a similarity index to combine pollen based REVEALS estimates with climate-driven dynamic vegetation modelling results. The overall results indicate that climate is the major driver of vegetation when the Holocene is considered as a whole and at the sub-continental scale, although land use is important regionally. Four critical phases of land-use effects on vegetation are identified. The first phase (from 7000 to 6500 BP) corresponds to the early impacts on vegetation of farming and Neolithic forest clearance and to the dominance of climate as a driver of vegetation change. During the second phase (from 4500 to 4000 BP), land use becomes a major control of vegetation. Climate is still the principal driver, although its influence decreases gradually. The third phase (from 2000 to 1500 BP) is characterised by the continued role of climate on vegetation as a consequence of late-Holocene climate shifts and specific climate events that influence vegetation as well as land use. The last phase (from 500 to 350 BP) shows an acceleration of vegetation changes, in particular during the last century, caused by new farming practices and forestry in response to population growth and industrialization. This is a unique signature of anthropogenic impact within the Holocene but European vegetation remains climatically sensitive and thus may continue to respond to ongoing climate change. (C) 2017 Elsevier Ltd. All rights reserved.
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| 7. |
- Mullier, G.A., et al.
(författare)
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Observation of gauge boson joint-polarisation states in W± Z production from pp collisions at √s=13TeV with the ATLAS detector
- 2023
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Ingår i: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 843
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Tidskriftsartikel (refereegranskat)abstract
- Measurements of joint-polarisation states of W and Z gauge bosons in W±Z production are presented. The data set used corresponds to an integrated luminosity of 139 fb−1 of proton–proton collisions at a centre-of-mass energy of 13 TeV recorded by the ATLAS detector at the CERN Large Hadron Collider. The W±Z candidate events are reconstructed using leptonic decay modes of the gauge bosons into electrons and muons. The simultaneous pair-production of longitudinally polarised vector bosons is measured for the first time with a significance of 7.1 standard deviations. The measured joint helicity fractions integrated over the fiducial region are f00=0.067±0.010, f0T=0.110±0.029, fT0=0.179±0.023 and fTT=0.644±0.032, in agreement with the next-to-leading-order Standard Model predictions. Individual helicity fractions of the W and Z bosons are also measured and found to be consistent with joint helicity fractions within the expected amounts of correlation. Both the joint and individual helicity fractions are also measured separately in W+Z and W−Z events. Inclusive and differential cross sections for several kinematic observables sensitive to polarisation are presented.
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| 8. |
- Pernebo, Karin, et al.
(författare)
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Outcomes of psychotherapeutic and psychoeducative group interventions for children exposed to intimate partner violence
- 2018
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Ingår i: International Journal of Child Abuse & Neglect. - : Elsevier Ltd. - 0145-2134 .- 1873-7757. ; 79, s. 213-223
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Tidskriftsartikel (refereegranskat)abstract
- Witnessing violence toward a caregiver during childhood is associated with negative impact on children's health and development, and there is a need for effective interventions for children exposed to intimate partner violence in clinical as well as in community settings. The current effectiveness study investigated symptom reduction after participation in two established group interventions (one community-based psychoeducative intervention; one psychotherapeutic treatment intervention) for children exposed to intimate partner violence and for their non-offending parent. The study included 50 children—24 girls and 26 boys—aged 4–13 years and their mothers. Child and maternal mental health problems and trauma symptoms were assessed pre- and post-treatment. The results indicate that although children showed benefits from both interventions, symptom reduction was larger in the psychotherapeutic intervention, and children with initially high levels of trauma symptoms benefited the most. Despite these improvements, a majority of the children's mothers still reported child trauma symptoms at clinical levels post-treatment. Both interventions substantially reduced maternal post-traumatic stress. The results indicate a need for routine follow-up of children's symptoms after interventions.
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| 9. |
- Pernebo, Karin, et al.
(författare)
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Reduced psychiatric symptoms at 6 and 12 months’ follow-up of psychotherapeutic and psychoeducative group interventions for children exposed to intimate partner violence
- 2019
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Ingår i: International Journal of Child Abuse & Neglect. - : Elsevier. - 0145-2134 .- 1873-7757. ; 93, s. 228-238
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Tidskriftsartikel (refereegranskat)abstract
- Background: Long-term follow-up studies of interventions for children exposed to intimate partner violence are few, and the sustainability of their outcomes often remains unexplored and uncertain. Current research including follow-up assessment suggests that treatment gains may be maintained or continue post termination. In addition some children may show increased levels of symptoms. Objective: The present effectiveness study investigated the long-term outcomes of two established group interventions for children exposed to intimate partner violence and their non-offending parent. Participants and Setting: The study included 50 children, 24 girls and 26 boys, aged 4 to 13 years attending a psychotherapeutic child and adolescent mental health service intervention and a psychoeducative community-based intervention. Methods: Background information, child and parental mental health problems, trauma symptoms, and exposure to violence were assessed pre- and post treatment and at 6 and 12 months’ follow-up. Results: Sustained treatment gains and late improvements in children's internalizing and externalizing symptoms and in symptoms of traumatic stress were recorded from post treatment to the follow-up assessments (p =.004–.044; d = 0.29–0.67). No significant increase in symptoms was reported. Additionally, very little continued or renewed child exposure to violence was reported. Conclusions: The results of the study indicate that the children did benefit from the two interventions studied and that the outcomes of reduced child symptoms and protection from exposure to violence were sustainable. Children with severe trauma symptoms benefited the most, though maternal psychological problems may for some have hindered recovery. Clinical implications are discussed.
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| 10. |
- Rasmusson, Bodil, et al.
(författare)
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Child-centered social work practice : three unique meanings in the context of looking after children and the assessment framwork in Australia, Canada and Sweden
- 2010
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Ingår i: Children and youth services review. - New York : Pergamon Press. - 0190-7409 .- 1873-7765. ; 32:3, s. 452-459
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Tidskriftsartikel (refereegranskat)abstract
- This paper explores different orientations to child-centered social work as conveyed in the training materials and guidelines of Looking After Children and Assessment Framework in Australia, Canada and Sweden. ‘Child centered’ is shaped by contextual factors and influences social work practices. We found differences in these approaches as needs based and/or rights based and in relation to how each emphasizes the three P's — Provision, Protection and Participation. Substantial differences were identified both in how references to a child-centered approach appear in theoretical frameworks, values, motives and use of concepts in training materials and guidelines, and in the instructions given as to how to apply these approaches. It appears that Australia balances needs and rights, while Canada is more needs-oriented and Sweden more rights-oriented. Swedish materials show a more explicit emphasis on participation than Australian and Canadian materials. Differences between the three countries indicate the importance of structural, contextual factors shaping orientations to child-centered practice.
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