| 491. |
- Hari-Gupta, Yukti, et al.
(författare)
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Myosin VI regulates the spatial organisation of mammalian transcription initiation
- 2022
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- During transcription, RNA Polymerase II (RNAPII) is spatially organised within the nucleus into clusters that correlate with transcription activity. While this is a hallmark of genome regulation in mammalian cells, the mechanisms concerning the assembly, organisation and stability remain unknown. Here, we have used combination of single molecule imaging and genomic approaches to explore the role of nuclear myosin VI (MVI) in the nanoscale organisation of RNAPII. We reveal that MVI in the nucleus acts as the molecular anchor that holds RNAPII in high density clusters. Perturbation of MVI leads to the disruption of RNAPII localisation, chromatin organisation and subsequently a decrease in gene expression. Overall, we uncover the fundamental role of MVI in the spatial regulation of gene expression.
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| 492. |
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| 493. |
- Hinde, D. J., et al.
(författare)
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Experimental investigation of the role of shell structure in quasifission mass distributions
- 2022
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Ingår i: Physical Review C. - : American Physical Society. - 2469-9985 .- 2469-9993. ; 106:6
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Tidskriftsartikel (refereegranskat)abstract
- Background: To understand superheavy element synthesis reactions, quantifying the role of quantum shells in quasifission dynamics is important. In reactions with actinide nuclides, a wide peak in the binary quasifission mass yield is seen, centered close to the 208Pb mass. It is generally attributed to the 208Pb spherical closed shells causing a valley in the potential-energy surface, attracting flux to these mass splits. However, an early experiment studying 48Ca, 50Ti+238U reactions showed strong evidence that sequential fission plays an important role in generating the observed peak. These conflicting interpretations have not been resolved up to now.Purpose: This work aims to measure quasifission mass spectra for reactions with nuclei lighter than 208Pb, having negligible sequential fission, to search for systematic features correlated with the proton shells known to affect low-energy fission mass distributions of the same actinide elements.Methods: Systematic measurements have been made at energies near and below the capture barriers (where quasifission is most prominent) of mass-angle distributions for fission following collisions of 48Ti projectiles with even-even nuclides from 154Sm to 200Hg. Mean excitation energies above the ground-states ranged from 51 to 33 MeV, respectively.Results: With increasing compound nucleus atomic number ZCN, a rapid transition occurs from fission having characteristics of fusion-fission to fast quasifission. The heaviest reactions form 240Cf, 244Fm, and 248No. Low -energy fission of neighboring isotopes is mass asymmetric, correlated with proton number Z = 56. However, peak quasifission yields are at mass-symmetry for all reactions. There appears to be a very small (P-3%) systematic excess of yield correlated with Z = 56, however this is at the limit of sensitivity of the experiment.Conclusions: No significant (>3%) systematic features are seen in the quasifission mass spectra that can be unambiguously identified as resulting from shells. This small influence may result from attenuation of shell effects due to the excitation energy introduced, even in these near-barrier reactions giving low excitation energies typical of superheavy element synthesis reactions.
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| 494. |
- 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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| 495. |
- Holbein, Christina E., et al.
(författare)
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Health behaviours reported by adults with congenital heart disease across 15 countries
- 2020
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Ingår i: European Journal of Preventive Cardiology. - : Oxford University Press (OUP). - 2047-4873 .- 2047-4881. ; 10, s. 1077-1087
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Tidskriftsartikel (refereegranskat)abstract
- Background: Health behaviours are essential to maintain optimal health and reduce the risk of cardiovascular complications in adults with congenital heart disease. This study aimed to describe health behaviours in adults with congenital heart disease in 15 countries and to identify patient characteristics associated with optimal health behaviours in the international sample. Design: This was a cross-sectional observational study. Methods: Adults with congenital heart disease (n = 4028, median age = 32 years, interquartile range 25–42 years) completed self-report measures as part of the Assessment of Patterns of Patient-Reported Outcomes in Adults with Congenital Heart disease - International Study (APPROACH-IS). Participants reported on seven health behaviours using the Health Behaviors Scale-Congenital Heart Disease. Demographic and medical characteristics were assessed via medical chart review and self-report. Multivariate path analyses with inverse sampling weights were used to investigate study aims. Results: Health behaviour rates for the full sample were 10% binge drinking, 12% cigarette smoking, 6% recreational drug use, 72% annual dental visit, 69% twice daily tooth brushing, 27% daily dental flossing and 43% sport participation. Pairwise comparisons indicated that rates differed between countries. Rates of substance use behaviours were higher in younger, male participants. Optimal dental health behaviours were more common among older, female participants with higher educational attainment while sports participation was more frequent among participants who were younger, male, married, employed/students, with higher educational attainment, less complex anatomical defects and better functional status. Conclusions: Health behaviour rates vary by country. Predictors of health behaviours may reflect larger geographic trends. Our findings have implications for the development and implementation of programmes for the assessment and promotion of optimal health behaviours in adults with congenital heart disease. © The European Society of Cardiology 2019.
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| 496. |
- 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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| 497. |
- Horio, M., et al.
(författare)
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Three-Dimensional Fermi Surface of Overdoped La-Based Cuprates
- 2018
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Ingår i: Physical Review Letters. - : American Physical Society. - 0031-9007 .- 1079-7114. ; 121:7
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Tidskriftsartikel (refereegranskat)abstract
- We present a soft x-ray angle-resolved photoemission spectroscopy study of overdoped high-temperature superconductors. In-plane and out-of-plane components of the Fermi surface are mapped by varying the photoemission angle and the incident photon energy. No k(z) dispersion is observed along the nodal direction, whereas a significant antinodal k(z) dispersion is identified for La-based cuprates. Based on a tight-binding parametrization, we discuss the implications for the density of states near the van Hove singularity. Our results suggest that the large electronic specific heat found in overdoped La2-xSrxCuO4 cannot be assigned to the van Hove singularity alone. We therefore propose quantum criticality induced by a collapsing pseudogap phase as a plausible explanation for observed enhancement of electronic specific heat.
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| 498. |
- Horio, M., et al.
(författare)
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Two-dimensional type-II Dirac fermions in layered oxides
- 2018
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Ingår i: Nature Communications. - : NATURE PUBLISHING GROUP. - 2041-1723. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Relativistic massless Dirac fermions can be probed with high-energy physics experiments, but appear also as low-energy quasi-particle excitations in electronic band structures. In condensed matter systems, their massless nature can be protected by crystal symmetries. Classification of such symmetry-protected relativistic band degeneracies has been fruitful, although many of the predicted quasi-particles still await their experimental discovery. Here we reveal, using angle-resolved photoemission spectroscopy, the existence of two-dimensional type-II Dirac fermions in the high-temperature superconductor La1.77Sr0.23CuO4. The Dirac point, constituting the crossing of d(x2-y2) and d(z2) bands, is found approximately one electronvolt below the Fermi level (E-F) and is protected by mirror symmetry. If spin-orbit coupling is considered, the Dirac point degeneracy is lifted and the bands acquire a topologically non-trivial character. In certain nickelate systems, band structure calculations suggest that the same type-II Dirac fermions can be realised near EF.
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| 499. |
- Howard, Steven J., et al.
(författare)
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Challenging socioeconomic status : A cross-cultural comparison of early executive function
- 2020
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Ingår i: Developmental Science. - : John Wiley & Sons. - 1363-755X .- 1467-7687. ; 23:1
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Tidskriftsartikel (refereegranskat)abstract
- The widely and internationally replicated socioeconomic status (SES) gradient of executive function (EF) implies that intervention approaches may do well to extrapolate conditions and practices from contexts that generate better child outcomes (in this case, higher SES circumstances) and translate these to contexts with comparatively poorer outcomes (often low-SES populations). Yet, can the reverse also be true? Using data from equivalent assessments of 1,092 pre-schoolers' EFs in South Africa and Australia, we evaluated: the SES gradient of EF within each sample; and whether this SES gradient extended cross-culturally. The oft-found EF-SES gradients were replicated in both samples. However, contrary to the inferences of EF-SES associations found nationally, the most highly disadvantaged South African subsample outperformed middle- and high-SES Australian pre-schoolers on two of three EFs. This suggests the possibility of EF-protective and -promotive practices within low- and middle-income countries that may aid understandings of the nature and promotion of EFs.
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| 500. |
- Hunter, Deidre A., et al.
(författare)
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A Study of Two Dwarf Irregular Galaxies with Asymmetrical Star Formation Distributions
- 2018
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 0004-637X .- 1538-4357. ; 855:1
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Tidskriftsartikel (refereegranskat)abstract
- Two dwarf irregular galaxies, DDO 187 and NGC 3738, exhibit a striking pattern of star formation: intense star formation is taking place in a large region occupying roughly half of the inner part of the optical galaxy. We use data on the H I distribution and kinematics and stellar images and colors to examine the properties of the environment in the high star formation rate (HSF) halves of the galaxies in comparison with the low star formation rate halves. We find that the pressure and gas density are higher on the HSF sides by 30%-70%. In addition we find in both galaxies that the H I velocity fields exhibit significant deviations from ordered rotation and there are large regions of high-velocity dispersion and multiple velocity components in the gas beyond the inner regions of the galaxies. The conditions in the HSF regions are likely the result of large-scale external processes affecting the internal environment of the galaxies and enabling the current star formation there.
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