| 1. |
- Aharony, Ofer, et al.
(författare)
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The analytic bootstrap for large N Chern-Simons vector models
- 2018
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Ingår i: Journal of High Energy Physics (JHEP). - 1126-6708 .- 1029-8479. ; :8
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Tidskriftsartikel (refereegranskat)abstract
- Three-dimensional Chern-Simons vector models display an approximate higher spin symmetry in the large N limit. Their single-trace operators consist of a tower of weakly broken currents, as well as a scalar a of approximate twist 1 or 2. We study the consequences of crossing symmetry for the four-point correlator of a in a 1/N expansion, using analytic bootstrap techniques. To order 1/N we show that crossing symmetry fixes the contribution from the tower of currents, providing an alternative derivation of well-known results by Maldacena and Zhiboedov. When sigma has twist 1 its OPE receives a contribution from the exchange of a itself with an arbitrary coefficient, due to the existence of a marginal sextic coupling. We develop the machinery to determine the corrections to the OPE data of double-trace operators due to this, and to similar exchanges. This in turns allows us to fix completely the correlator up to three known truncated solutions to crossing. We then proceed to study the problem to order 1/N-2. We find that crossing implies the appearance of odd-twist double-trace operators, and calculate their OPE coefficients in a large spin expansion. Also, surprisingly, crossing at order 1/N-2, implies non-trivial O(1/N) anomalous dimensions for even-twist double-trace operators, even though such contributions do not appear in the four-point function at order 1/N (in the case where there is no scalar exchange). We argue that this phenomenon arises due to operator mixing. Finally, we analyse the bosonic vector model with a sextic coupling without gauge interactions, and determine the order 1/N-2 corrections to the dimensions of twist-2 double-trace operators.
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| 2. |
- Alday, Luis F., et al.
(författare)
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Genus-One String Amplitudes from Conformal Field Theory
- 2019
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Ingår i: Journal of High Energy Physics (JHEP). - 1126-6708 .- 1029-8479. ; :6
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Tidskriftsartikel (refereegranskat)abstract
- We explore and exploit the relation between non-planar correlators in N=4 super-Yang-Mills, and higher-genus closed string amplitudes in type IIB string theory. By conformal field theory techniques we construct the genus-one, four-point string amplitude in AdS5×S5 in the low-energy expansion, dual to an N=4 super-Yang-Mills correlator in the 't Hooft limit at order 1/c2 in a strong coupling expansion. In the flat space limit, this maps onto the genus-one, four-point scattering amplitude for type II closed strings in ten dimensions. Using this approach we reproduce several results obtained via string perturbation theory. We also demonstrate a novel mechanism to fix subleading terms in the flat space limit of AdS amplitudes by using string/M-theory.
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| 3. |
- Apers, Silke, et al.
(författare)
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Assessment of Patterns of Patient-Reported Outcomes in Adults with Congenital Heart disease - International Study (APPROACH-IS) : Rationale, design, and methods
- 2015
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Ingår i: International Journal of Cardiology. - : Elsevier BV. - 0167-5273 .- 1874-1754. ; 179, s. 334-342
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Tidskriftsartikel (refereegranskat)abstract
- Background: Data on patient-reported outcomes (PROs) in adults with congenital heart disease (CHD) are inconsistent and vary across the world. Better understanding of PROs and their differences across cultural and geographic barriers can best be accomplished via international studies using uniform research methods. The APPROACH-IS consortium (Assessment of Patterns of Patient-Reported Outcomes in Adults with Congenital Heart disease - International Study) was created for this purpose and investigates PROs in adults with CHD worldwide. This paper outlines the project rationale, design, and methods. Methods/design: APPROACH-IS is a cross-sectional study. The goal is to recruit 3500-4000 adults with CHD from 15 countries in five major regions of the world (Asia, Australia, Europe, North and South America). Self-report questionnaires are administered to capture information on PRO domains: (i) perceived health status (12-item Short-form Health Survey & EuroQOL-5D); (ii) psychological functioning (Hospital Anxiety and Depression Scale); (iii) health behaviors (Health-Behavior Scale-Congenital Heart Disease); and (iv) quality of life (Linear Analog Scale & Satisfaction With Life Scale). Additionally, potential explanatory variables are assessed: (i) socio-demographic variables; (ii) medical history (chart review); (iii) sense of coherence (Orientation to Life Questionnaire); and (iv) illness perceptions (Brief Illness Perception Questionnaire). Descriptive analyses and multilevel models will examine differences in PROs and investigate potential explanatory variables. Discussion: APPROACH-IS represents a global effort to increase research understanding and capacity in the field of CHD, and will have major implications for patient care. Results will generate valuable information for developing interventions to optimize patients' health and well-being.
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| 4. |
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| 5. |
- Holbein, Christina E., et al.
(författare)
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A multinational observational investigation of illness perceptions and quality of life among patients with a Fontan circulation
- 2018
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Ingår i: Congenital Heart Disease. - : Computers, Materials and Continua (Tech Science Press). - 1747-079X .- 1747-0803. ; 13:3, s. 392-400
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Tidskriftsartikel (refereegranskat)abstract
- Objective First, to compare QOL and illness perceptions between patients with a Fontan circulation and patients with anatomically simple defects (ie, atrial septal defects [ASD] or ventricular septal defects [VSD]). Second, to explore illness perceptions as a mediator of the association between congenital heart disease (CHD) diagnosis and QOL. Design Cross-sectional observational study. Setting Twenty-four cardiology centers from 15 countries across five continents. Patients Four hundred thirty-five adult patients with congenital heart disease (177 Fontan and 258 ASD/VSD) ages 18-83 years. Outcome Measures QOL and illness perceptions were assessed by the Satisfaction With Life Scale and the Brief Illness Perceptions Questionnaire, respectively. Results Patients with a Fontan circulation reported lower QOL (Wald Z = −3.59, p = <.001) and more negative perceptions of their CHD (Wald Z = −7.66, p < .001) compared with patients with ASD/VSD. After controlling for demographics, anxiety, depressive symptoms, and New York Heart Association functional class, path analyses revealed a significant mediation model, αβ = 0.15, p = .002, 95% CI = 0.06-0.25, such that CHD diagnosis was indirectly related to QOL through illness perceptions. Conclusions The Fontan sample’s more negative perceptions of CHD were likely a reflection of life with a more complex defect. Illness perceptions appear to account for unique differences in QOL between groups of varying CHD complexity. Psychosocial screening and interventions may be important treatment components for patients with CHD, particularly those with Fontan circulations.
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| 6. |
- Holbein, Christina E, et al.
(författare)
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Perceived Health Mediates Effects of Physical Activity on Quality of Life in Patients With a Fontan Circulation
- 2019
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Ingår i: American Journal of Cardiology. - : Elsevier BV. - 0002-9149 .- 1879-1913. ; 124:1, s. 144-150
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Tidskriftsartikel (refereegranskat)abstract
- Patients with a Fontan circulation are at risk of a sedentary lifestyle. Given the direct relationship between physical activity and health, promotion of physical activity has the potential to improve outcomes, including quality of life (QOL). This study aimed to describe self-reported physical activity levels in adult Fontan patients and examine associations between physical activity, perceived health status and QOL. The sample consisted of 177 Fontan patients (Mage = 27.5 ± 7.6 years, 52% male) who reported their physical activity, perceived health status, and QOL as part of the cross-sectional Assessment of Patterns of Patient-Reported Outcomes in Adults with Congenital Heart disease - International Study. Descriptive statistics and univariate analyses of variance with planned contrasts were computed to describe physical activity characteristics. Mediation analyses tested whether perceived health status variables mediated the association between physical activity and QOL. Forty-six percent of patients were sedentary while only 40% met international physical activity guidelines. Higher physical activity was associated with younger age, lower NYHA class, higher perceived general health, and greater QOL. Patients who commuted by walking and engaged in sports reported better perceived health and QOL. Mediation analyses revealed that perceived general health but not NYHA functional class mediated the association between physical activity and QOL (αβ = 0.22, 95% confidence interval = 0.04 to 0.49). In conclusion, Fontan patients likely benefit from regular physical activity, having both higher perceived general health and functional capacity; greater perceived health status may contribute to enhanced QOL. In conclusion, these data support the pivotal role of regular physical activity for Fontan patients.
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| 7. |
- Ko, Jong Mi, et al.
(författare)
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Differential impact of physical activity type on depression in adults with congenital heart disease : A multi-center international study
- 2019
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Ingår i: Journal of Psychosomatic Research. - : Elsevier BV. - 0022-3999 .- 1879-1360. ; 124
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: This study aimed to examine the association between physical activity (PA) and depression in a large international cohort of adults with congenital heart disease (ACHD) as data about the differential impact of PA type on depression in this population are lacking.METHODS: In 2018, we conducted a cross-sectional assessment of 3908 ACHD recruited from 24 ACHD-specialized centers in 15 countries between April 2013 to March 2015. The Hospital Anxiety and Depression Scale was used to assess self-reported depressive symptoms and the Health-Behavior Scale-Congenital Heart Disease was used to collect PA information. Cochran-Armitage tests were performed to assess trends between depressive symptom levels and PA participation. Chi-Square and Wilcoxon Rank Sum tests were utilized to examine relations between depressive symptom levels and patient characteristics. Stepwise multivariable models were then constructed to understand the independent impact of PA on depressive symptoms.RESULTS: The overall prevalence of elevated depressive symptoms in this sample was 12% with significant differences in rates between countries (p < .001). Physically active individuals were less likely to be depressed than those who were sedentary. Of the 2 PA domains examined, sport participation rather than active commute was significantly associated with reduced symptoms of depression. After adjustment in multivariable analysis, sport participation was still significantly associated with 38% decreased probability of depressive symptoms (p < .001).CONCLUSIONS: Sport participation is independently associated with reduced depressive symptoms. The development and promotion of sport-related exercise prescriptions uniquely designed for ACHD may improve depression status in this unique population.
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| 8. |
- Ko, Jong Mi, et al.
(författare)
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Physical Activity-Related Drivers of Perceived Health Status in Adults With Congenital Heart Disease
- 2018
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Ingår i: American Journal of Cardiology. - : Elsevier BV. - 0002-9149 .- 1879-1913. ; 122:8, s. 1437-1442
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Tidskriftsartikel (refereegranskat)abstract
- Data on the differential impact of physical activity on perceived health status (PHS) in a large adult congenital heart disease (ACHD) patient population are lacking. We conducted a cross-sectional assessment of 4,028 ACHD patients recruited from 24 ACHD-specialized centers in 15 countries across 5 continents to examine the association between physical activity and PHS in a large international cohort of ACHD patients. A linear analog scale of the EuroQol-5D 3 level version and the 12-item Short Form Health Survey-version 2 were used to assess self-reported health status and the Health-Behavior Scale-Congenital Heart Disease was used as a subjective measurement of physical activity type, participation, and level. Correlation analyses and Wilcoxon Rank Sum tests examined bivariate relations between sample characteristics and PHS scores. Then, multivariable models were constructed to understand the impact of physical activity on PHS. Only 30% of our sample achieved recommended physical activity levels. Physically active patients reported better PHS than sedentary patients; however, the amount of physical activity was not associated with PHS. Further statistical analyses demonstrated that specifically sport participation regardless of physical activity level was a predictor of PHS. In conclusion, the majority of ACHD patients across the world are physically inactive. Sport participation appears to be the primary physical activity-related driver of PHS. By promoting sport-related exercise ACHD specialists thus may improve PHS in ACHD patients.
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| 9. |
- Larsson, Lena, et al.
(författare)
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Geographical variation and predictors of physical activity level in adults with congenital heart disease
- 2019
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Ingår i: International Journal of Cardiology : Heart & Vasculature. - : Elsevier. - 2352-9067. ; 22, s. 20-25
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Tidskriftsartikel (refereegranskat)abstract
- Physical activity is important to maintain and promote health. This is of particular interest in patients with congenital heart disease(CHD) where acquired heart disease should be prevented. The World Health Organization (WHO) recommends a minimum of 2.5 h/week of physical activity exceeding 3 metabolic equivalents (METS) to achieve positive health effects. It is unknown whether physical activity levels (PAL) in adult CHD patients differ by country of origin.Methods3896 adults with CHD recruited from 15 countries over 5 continents completed self-reported instruments, including the Health Behaviour Scale (HBS-CHD), within the APPROACH-IS project. For each patient, we calculated whether WHO recommendations were achieved or not. Associated factors were investigated using Generalized Linear Mixed Models.ResultsOn average, 31% reached the WHO recommendations but with a great variation between geographical areas (India: 10%–Norway: 53%). Predictors for physical activity level in line with the WHO recommendations, with country of residence as random effect, were male sex (OR 1.78, 95%CI 1.52–2.08), NYHA-class I (OR 3.10, 95%CI 1.71–5.62) and less complex disease (OR 1.46, 95%CI 1.16–1.83). In contrast, older age (OR 0.97, 95%CI 0.96–0.98), lower educational level (OR 0.41, 95%CI 0.26–0.64) and being unemployed (OR 0.57, 95%CI 0.42–0.77) were negatively associated with reaching WHO recommendations.ConclusionsA significant proportion of patients with CHD did not reach the WHO physical activity recommendations. There was a large variation in physical activity level by country of origin. Based on identified predictors, vulnerable patients may be identified and offered specific behavioral interventions.
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