| 1. |
- Algaba, Juan-Carlos, et al.
(author)
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Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign
- 2021
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In: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8213 .- 2041-8205. ; 911:1
-
Research review (peer-reviewed)abstract
- In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the center of the M87 galaxy. The asymmetric ring morphology and size are consistent with theoretical expectations for a weakly accreting supermassive black hole of mass ∼6.5 × 109 M o˙. The EHTC also partnered with several international facilities in space and on the ground, to arrange an extensive, quasi-simultaneous multi-wavelength campaign. This Letter presents the results and analysis of this campaign, as well as the multi-wavelength data as a legacy data repository. We captured M87 in a historically low state, and the core flux dominates over HST-1 at high energies, making it possible to combine core flux constraints with the more spatially precise very long baseline interferometry data. We present the most complete simultaneous multi-wavelength spectrum of the active nucleus to date, and discuss the complexity and caveats of combining data from different spatial scales into one broadband spectrum. We apply two heuristic, isotropic leptonic single-zone models to provide insight into the basic source properties, but conclude that a structured jet is necessary to explain M87's spectrum. We can exclude that the simultaneous γ-ray emission is produced via inverse Compton emission in the same region producing the EHT mm-band emission, and further conclude that the γ-rays can only be produced in the inner jets (inward of HST-1) if there are strongly particle-dominated regions. Direct synchrotron emission from accelerated protons and secondaries cannot yet be excluded.
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| 2. |
- Abe, H., et al.
(author)
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Gamma-ray observations of MAXI J1820+070 during the 2018 outburst
- 2022
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In: Monthly notices of the Royal Astronomical Society. - : Oxford University Press. - 0035-8711 .- 1365-2966. ; 517:4, s. 4736-4751
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Journal article (peer-reviewed)abstract
- MAXIJ1820+070 is a low-mass X-ray binary with a black hole (BH) as a compact object. This binary underwent an exceptionally bright X-ray outburst from 2018 March to October, showing evidence of a non-thermal particle population through its radio emission during this whole period. The combined results of 59.5 h of observations of the MAXI J1820+070 outburst with the H.E.S.S., MAGIC and VERITAS experiments at energies above 200 GeV are presented, together with Fermi-LAT data between 0.1 and 500 GeV, and multiwavelength observations from radio to X-rays. Gamma-ray emission is not detected from MAXI J1820+070, but the obtained upper limits and the multiwavelength data allow us to put meaningful constraints on the source properties under reasonable assumptions regarding the non-thermal particle population and the jet synchrotron spectrum. In particular, it is possible to show that, if a high-energy (HE) gamma-ray emitting region is present during the hard state of the source, its predicted flux should be at most a factor of 20 below the obtained Fermi-LAT upper limits, and closer to them for magnetic fields significantly below equipartition. During the state transitions, under the plausible assumption that electrons are accelerated up to similar to 500 GeV, the multiwavelength data and the gamma-ray upper limits lead consistently to the conclusion that a potential HE and very-HE gamma-ray emitting region should be located at a distance from the BH ranging between 10(11) and 10(13) cm. Similar outbursts from low-mass X-ray binaries might be detectable in the near future with upcoming instruments such as CTA.
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| 3. |
- Abdalla, H., et al.
(author)
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Sensitivity of the Cherenkov Telescope Array for probing cosmology and fundamental physics with gamma-ray propagation
- 2021
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In: Journal of Cosmology and Astroparticle Physics. - : Institute of Physics Publishing (IOPP). - 1475-7516. ; :2
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Journal article (peer-reviewed)abstract
- The Cherenkov Telescope Array (CTA), the new-generation ground-based observatory for gamma-ray astronomy, provides unique capabilities to address significant open questions in astrophysics, cosmology, and fundamental physics. We study some of the salient areas of gamma-ray cosmology that can be explored as part of the Key Science Projects of CTA, through simulated observations of active galactic nuclei (AGN) and of their relativistic jets. Observations of AGN with CTA will enable a measurement of gamma-ray absorption on the extragalactic background light with a statistical uncertainty below 15% up to a redshift z = 2 and to constrain or detect gamma-ray halos up to intergalactic-magnetic-field strengths of at least 0.3 pG. Extragalactic observations with CTA also show promising potential to probe physics beyond the Standard Model. The best limits on Lorentz invariance violation from gamma-ray astronomy will be improved by a factor of at least two to three. CTA will also probe the parameter space in which axion-like particles could constitute a significant fraction, if not all, of dark matter. We conclude on the synergies between CTA and other upcoming facilities that will foster the growth of gamma-ray cosmology.
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| 4. |
- Adams, C. B., et al.
(author)
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Observation of the Gamma-Ray Binary HESS J0632+057 with the HESS, MAGIC, and VERITAS Telescopes
- 2021
-
In: Astrophysical Journal. - : Institute of Physics Publishing (IOPP). - 0004-637X .- 1538-4357. ; 923:2
-
Journal article (peer-reviewed)abstract
- The results of gamma-ray observations of the binary system HESS J0632 + 057 collected during 450 hr over 15 yr, between 2004 and 2019, are presented. Data taken with the atmospheric Cherenkov telescopes H.E.S.S., MAGIC, and VERITAS at energies above 350 GeV were used together with observations at X-ray energies obtained with Swift-XRT, Chandra, XMM-Newton, NuSTAR, and Suzaku. Some of these observations were accompanied by measurements of the H alpha emission line. A significant detection of the modulation of the very high-energy gamma-ray fluxes with a period of 316.7 +/- 4.4 days is reported, consistent with the period of 317.3 +/- 0.7 days obtained with a refined analysis of X-ray data. The analysis of data from four orbital cycles with dense observational coverage reveals short-timescale variability, with flux-decay timescales of less than 20 days at very high energies. Flux variations observed over a timescale of several years indicate orbit-to-orbit variability. The analysis confirms the previously reported correlation of X-ray and gamma-ray emission from the system at very high significance, but cannot find any correlation of optical H alpha parameters with fluxes at X-ray or gamma-ray energies in simultaneous observations. The key finding is that the emission of HESS J0632 + 057 in the X-ray and gamma-ray energy bands is highly variable on different timescales. The ratio of gamma-ray to X-ray flux shows the equality or even dominance of the gamma-ray energy range. This wealth of new data is interpreted taking into account the insufficient knowledge of the ephemeris of the system, and discussed in the context of results reported on other gamma-ray binary systems.
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| 5. |
- Obers, Niels A., et al.
(author)
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Quantum gravity phenomenology at the dawn of the multi-messenger era—A review
- 2022
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In: Progress in Particle and Nuclear Physics. - : Elsevier BV. - 0146-6410 .- 1873-2224. ; 125
-
Research review (peer-reviewed)abstract
- The exploration of the universe has recently entered a new era thanks to the multi-messenger paradigm, characterized by a continuous increase in the quantity and quality of experimental data that is obtained by the detection of the various cosmic messengers (photons, neutrinos, cosmic rays and gravitational waves) from numerous origins. They give us information about their sources in the universe and the properties of the intergalactic medium. Moreover, multi-messenger astronomy opens up the possibility to search for phenomenological signatures of quantum gravity. On the one hand, the most energetic events allow us to test our physical theories at energy regimes which are not directly accessible in accelerators; on the other hand, tiny effects in the propagation of very high energy particles could be amplified by cosmological distances. After decades of merely theoretical investigations, the possibility of obtaining phenomenological indications of Planck-scale effects is a revolutionary step in the quest for a quantum theory of gravity, but it requires cooperation between different communities of physicists (both theoretical and experimental). This review, prepared within the COST Action CA18108 “Quantum gravity phenomenology in the multi-messenger approach”, is aimed at promoting this cooperation by giving a state-of-the art account of the interdisciplinary expertise that is needed in the effective search of quantum gravity footprints in the production, propagation and detection of cosmic messengers.
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| 6. |
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| 7. |
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| 8. |
- Stolk, Lisette, et al.
(author)
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Meta-analyses identify 13 loci associated with age at menopause and highlight DNA repair and immune pathways
- 2012
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In: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 44:3, s. 260-268
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Journal article (peer-reviewed)abstract
- To newly identify loci for age at natural menopause, we carried out a meta-analysis of 22 genome-wide association studies (GWAS) in 38,968 women of European descent, with replication in up to 14,435 women. In addition to four known loci, we identified 13 loci newly associated with age at natural menopause (at P < 5 × 10(-8)). Candidate genes located at these newly associated loci include genes implicated in DNA repair (EXO1, HELQ, UIMC1, FAM175A, FANCI, TLK1, POLG and PRIM1) and immune function (IL11, NLRP11 and PRRC2A (also known as BAT2)). Gene-set enrichment pathway analyses using the full GWAS data set identified exoDNase, NF-κB signaling and mitochondrial dysfunction as biological processes related to timing of menopause.
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| 9. |
- Dainiak, N, et al.
(author)
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First global consensus for evidence-based management of the hematopoietic syndrome resulting from exposure to ionizing radiation
- 2011
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In: Disaster medicine and public health preparedness. - : Cambridge University Press (CUP). - 1938-744X .- 1935-7893. ; 5:3, s. 202-212
-
Journal article (peer-reviewed)abstract
- Objective:Hematopoietic syndrome (HS) is a clinical diagnosis assigned to people who present with ≥1 new-onset cytopenias in the setting of acute radiation exposure. The World Health Organization convened a panel of experts to evaluate the evidence and develop recommendations for medical countermeasures for the management of HS in a hypothetical scenario involving the hospitalization of 100 to 200 individuals exposed to radiation. The objective of this consultancy was to develop recommendations for treatment of the HS based upon the quality of evidence.Methods:English-language articles were identified in MEDLINE and PubMed. Reference lists of retrieved articles were distributed to panel members before the meeting and updated during the meeting. Published case series and case reports of individuals with HS, published randomized controlled trials of relevant interventions used to treat nonirradiated individuals, reports of studies in irradiated animals, and prior recommendations of subject matter experts were selected. Studies were extracted using the Grading of Recommendations Assessment Development and Evaluation (GRADE) system. In cases in which data were limited or incomplete, a narrative review of the observations was made. No randomized controlled trials of medical countermeasures have been completed for individuals with radiation-associated HS. The use of GRADE analysis of countermeasures for injury to hematopoietic tissue was restricted by the lack of comparator groups in humans. Reliance on data generated in nonirradiated humans and experimental animals was necessary.Results:Based upon GRADE analysis and narrative review, a strong recommendation was made for the administration of granulocyte colony-stimulating factor or granulocyte macrophage colony-stimulating factor and a weak recommendation was made for the use of erythropoiesis-stimulating agents or hematopoietic stem cell transplantation.Conclusions:Assessment of therapeutic interventions for HS in humans exposed to nontherapeutic radiation is difficult because of the limits of the evidence.(Disaster Med Public Health Preparedness. 2011;5:202-212)
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| 10. |
- Dainiak, N, et al.
(author)
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Literature review and global consensus on management of acute radiation syndrome affecting nonhematopoietic organ systems
- 2011
-
In: Disaster medicine and public health preparedness. - : Cambridge University Press (CUP). - 1938-744X .- 1935-7893. ; 5:3, s. 183-201
-
Journal article (peer-reviewed)abstract
- Objectives:The World Health Organization convened a panel of experts to rank the evidence for medical countermeasures for management of acute radiation syndrome (ARS) in a hypothetical scenario involving the hospitalization of 100 to 200 victims. The goal of this panel was to achieve consensus on optimal management of ARS affecting nonhematopoietic organ systems based upon evidence in the published literature.Methods:English-language articles were identified in MEDLINE and PubMed. Reference lists of retrieved articles were distributed to conferees in advance of and updated during the meeting. Published case series and case reports of ARS, publications of randomized controlled trials of relevant interventions used to treat nonirradiated individuals, reports of studies in irradiated animals, and prior recommendations of subject matter experts were selected. Studies were extracted using the Grading of Recommendations Assessment Development and Evaluation system. In cases in which data were limited or incomplete, a narrative review of the observations was made.Results:No randomized controlled trials of medical countermeasures have been completed for individuals with ARS. Reports of countermeasures were often incompletely described, making it necessary to rely on data generated in nonirradiated humans and in experimental animals. A strong recommendation is made for the administration of a serotonin-receptor antagonist prophylactically when the suspected exposure is >2 Gy and topical steroids, antibiotics, and antihistamines for radiation burns, ulcers, or blisters; excision and grafting of radiation ulcers or necrosis with intractable pain; provision of supportive care to individuals with neurovascular syndrome; and administration of electrolyte replacement therapy and sedatives to individuals with significant burns, hypovolemia, and/or shock. A strong recommendation is made against the use of systemic steroids in the absence of a specific indication. A weak recommendation is made for the use of fluoroquinolones, bowel decontamination, loperamide, and enteral nutrition, and for selective oropharyngeal/digestive decontamination, blood glucose maintenance, and stress ulcer prophylaxis in critically ill patients.Conclusions:High-quality studies of therapeutic interventions in humans exposed to nontherapeutic radiation are not available, and because of ethical concerns regarding the conduct of controlled studies in humans, such studies are unlikely to emerge in the near future.(Disaster Med Public Health Preparedness. 2011;5:183–201)
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| 11. |
- Enervald, E, et al.
(author)
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A regulatory role for the cohesin loader NIPBL in nonhomologous end joining during immunoglobulin class switch recombination
- 2013
-
In: The Journal of experimental medicine. - : Rockefeller University Press. - 1540-9538 .- 0022-1007. ; 210:12, s. 2503-2513
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Journal article (peer-reviewed)abstract
- DNA double strand breaks (DSBs) are mainly repaired via homologous recombination (HR) or nonhomologous end joining (NHEJ). These breaks pose severe threats to genome integrity but can also be necessary intermediates of normal cellular processes such as immunoglobulin class switch recombination (CSR). During CSR, DSBs are produced in the G1 phase of the cell cycle and are repaired by the classical NHEJ machinery. By studying B lymphocytes derived from patients with Cornelia de Lange Syndrome, we observed a strong correlation between heterozygous loss-of-function mutations in the gene encoding the cohesin loading protein NIPBL and a shift toward the use of an alternative, microhomology-based end joining during CSR. Furthermore, the early recruitment of 53BP1 to DSBs was reduced in the NIPBL-deficient patient cells. Association of NIPBL deficiency and impaired NHEJ was also observed in a plasmid-based end-joining assay and a yeast model system. Our results suggest that NIPBL plays an important and evolutionarily conserved role in NHEJ, in addition to its canonical function in sister chromatid cohesion and its recently suggested function in HR.
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| 12. |
- Gast, Gerrie-Cor M, et al.
(author)
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Hormone therapy and coronary heart disease risk by vasomotor menopausal symptoms.
- 2011
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In: Maturitas. - : Elsevier BV. - 1873-4111 .- 0378-5122. ; 70:4, s. 373-378
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Journal article (peer-reviewed)abstract
- OBJECTIVES: We examined whether the association between hormone therapy (HT) use and coronary heart disease (CHD) risk differed between women with and without vasomotor symptoms (VMS). STUDY DESIGN: We used data from a Dutch (EPOS) and Swedish (WHILA) population-based sample of 8865 women, aged 46-64 years, and free of CHD, stroke, venous thrombosis/pulmonary embolism or cancer at baseline. Data on HT use, VMS and potential confounders were collected by questionnaires. MAIN OUTCOME MEASURES: CHD endpoints, obtained via registries. RESULTS: 252 CHD cases occurred during 10.3 years of follow-up. Neither for women with nor for women without flushing or (night) sweats ever HT use was associated with CHD risk, compared with never HT use. Among women with intense VMS, ever HT use borderline significantly decreased CHD risk compared with never HT use (HR 0.48 [95% CI 0.20-1.03]). Among women without intense VMS, ever HT use was associated with a borderline significant increased CHD risk (HR 1.28 [95% CI 0.96-1.70]; P for interaction=0.02). However, after multivariate adjustment, as compared to never HT use, ever HT use was not associated with risk of CHD among women with or without intense VMS. CONCLUSIONS: In both groups of women with and without VMS, HT use does not seem to be associated with the risk of CHD. Hence, our findings do not support the view that HT use increases the CHD risk among women with an indication, i.e. VMS, but this needs to be confirmed in specifically designed studies.
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| 13. |
- Gast, Gerrie-Cor M, et al.
(author)
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Menopausal Complaints Are Associated With Cardiovascular Risk Factors.
- 2008
-
In: Hypertension. - 1524-4563. ; 51:6, s. 1492-1498
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Journal article (peer-reviewed)abstract
- It has been hypothesized that women with vasomotor symptoms differ from those without with respect to cardiovascular risk factors or responses to exogenous hormone therapy. We studied whether the presence and extent of menopausal complaints are associated with cardiovascular risk profile. Data were used from a population-based sample of 5523 women, aged 46 to 57 years, enrolled between 1994 and 1995. Data on menopausal complaints and potential confounders were collected by questionnaires. Total cholesterol, systolic and diastolic blood pressures, and body mass index were measured. Linear and logistic regression analyses were used to analyze the data. Night sweats were reported by 38% and flushing by 39% of women. After multivariate adjustment, women with complaints of flushing had a 0.27-mmol/L (95% CI: 0.15 to 0.39) higher cholesterol level, a 0.60-kg/m(2) (95% CI: 0.35 to 0.84) higher BMI, a 1.59-mm Hg (95% CI: 0.52 to 2.67) higher systolic blood pressure, and a 1.09-mm Hg (95% CI: 0.48 to 1.69) higher diastolic blood pressure compared with asymptomatic women. Flushing was also associated with hypercholesterolemia (odds ratio: 1.52; 95% CI: 1.25 to 1.84) and hypertension (OR: 1.20; 95% CI: 1.07 to 1.34). Results were similar for complaints of night sweating. The findings support the view that menopausal complaints are associated with a less favorable cardiovascular risk profile. These findings substantiate the view that differences in the presence of menopausal symptoms as a reason for using hormone therapy could explain discrepant findings between observational research and trials.
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| 14. |
- Gast, Gerrie-Cor M, et al.
(author)
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Vasomotor menopausal symptoms are associated with increased risk of coronary heart disease.
- 2011
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In: Menopause. - : Ovid Technologies (Wolters Kluwer Health). - 1530-0374 .- 1072-3714. ; 18, s. 146-151
-
Journal article (peer-reviewed)abstract
- OBJECTIVE:: Emerging evidence suggests that women with vasomotor menopausal symptoms (VMS) may have an adverse cardiovascular disease (CVD) risk profile. We investigated whether VMS are related to an increased risk of future coronary heart disease (CHD) and whether possible associations can be explained by CVD risk factors. METHODS:: Data used were from a Dutch and Swedish population-based sample of 10,787 women enrolled between 1995 and 2000, aged 46 to 64 years, and free of CVD at baseline. Data on VMS were collected by questionnaires. Body mass index and blood pressure were measured in all women, and total cholesterol levels were measured in a subgroup of the population. Multivariable Cox regression models were used to analyze the data. RESULTS:: After a mean ± SD follow-up period of 10.3 ± 2.1 years, 303 women were diagnosed with CHD. Symptoms of flushing were not associated with risk of CHD. However, the presence of night sweats was associated with a significantly modest increased risk of CHD, with a multivariable-adjusted hazard ratio of 1.33 (95% CI, 1.05-1.69). This association was attenuated but not eliminated after correction for body mass index, blood pressure, and total cholesterol (hazard ratio, 1.25; 95% CI, 0.99-1.58). CONCLUSIONS:: Women with menopausal symptoms of night sweats have a significantly moderately increased risk of CHD, which cannot be totally explained by the levels of CVD risk factors.
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| 15. |
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| 16. |
- Warnecke, J., et al.
(author)
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Investigating Global Convective Dynamos with Mean-field Models : Full Spectrum of Turbulent Effects Required
- 2021
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In: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8205 .- 2041-8213. ; 919:2
-
Journal article (peer-reviewed)abstract
- The role of turbulent effects for dynamos in the Sun and stars continues to be debated. Mean-field (MF) theory provides a broadly used framework to connect these effects to fundamental magnetohydrodynamics. While inaccessible observationally, turbulent effects can be directly studied using global convective dynamo (GCD) simulations. We measure the turbulent effects in terms of turbulent transport coefficients, based on the MF framework, from an exemplary GCD simulation using the test-field method. These coefficients are then used as an input into an MF model. We find a good agreement between the MF and GCD solutions, which validates our theoretical approach. This agreement requires all turbulent effects to be included, even those which have been regarded as unimportant so far. Our results suggest that simple dynamo models, as are commonly used in the solar and stellar community, relying on very few, precisely fine-tuned turbulent effects, may not be representative of the full dynamics of dynamos in global convective simulations and astronomical objects.
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| 17. |
- Warnecke, Jörn, et al.
(author)
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Numerical evidence for a small-scale dynamo approaching solar magnetic Prandtl numbers
- 2023
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In: Nature Astronomy. - : Springer Nature. - 2397-3366. ; 7:6, s. 662-668
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Journal article (peer-reviewed)abstract
- Magnetic fields on small scales are ubiquitous in the Universe. Although they can often be observed in detail, their generation mechanisms are not fully understood. One possibility is the so-called small-scale dynamo (SSD). Prevailing numerical evidence, however, appears to indicate that an SSD is unlikely to exist at very low magnetic Prandtl numbers (PrM) such as those that are present in the Sun and other cool stars. Here we have performed high-resolution simulations of isothermal forced turbulence using the lowest PrM values achieved so far. Contrary to earlier findings, the SSD not only turns out to be possible for PrM down to 0.0031 but also becomes increasingly easier to excite for PrM below about 0.05. We relate this behaviour to the known hydrodynamic phenomenon referred to as the bottleneck effect. Extrapolating our results to solar values of PrM indicates that an SSD would be possible under such conditions.
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| 18. |
- Eriksson, Bengt I., 1946, et al.
(author)
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Oral rivaroxaban for the prevention of symptomatic venous thromboembolism after elective hip and knee replacement
- 2009
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In: Journal of Bone and Joint Surgery. - 0301-620X. ; 91:5, s. 636-44
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Journal article (peer-reviewed)abstract
- A once-daily dose of rivaroxaban 10 mg, an oral, direct Factor Xa inhibitor, was compared with enoxaparin 40 mg subcutaneously once daily for prevention of venous thromboembolism in three studies of patients undergoing elective hip and knee replacement (RECORD programme). A pooled analysis of data from these studies (n = 9581) showed that rivaroxaban was more effective than enoxaparin in reducing the incidence of the composite of symptomatic venous thromboembolism and all-cause mortality at two weeks (0.4% vs 0.8%, respectively, odds ratio 0.44; 95% confidence interval 0.23 to 0.79; p = 0.005), and at the end of the planned medication period (0.5% vs 1.3%, respectively; odds ratio 0.38; 95% confidence interval 0.22 to 0.62; p < 0.001). The rate of major bleeding was similar at two weeks (0.2% for both) and at the end of the planned medication period (0.3% vs 0.2%). Rivaroxaban started six to eight hours after surgery was more effective than enoxaparin started the previous evening in preventing symptomatic venous thromboembolism and all-cause mortality, without increasing major bleeding.
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| 19. |
- Gent, Matthew Raymond, et al.
(author)
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The SAPP pipeline for the determination of stellar abundances and atmospheric parameters of stars in the core program of the PLATO mission
- 2022
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In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 658
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Journal article (peer-reviewed)abstract
- We introduce the SAPP (Stellar Abundances and atmospheric Parameters Pipeline), the prototype of the code that will be used to determine parameters of stars observed within the core program of the PLATO space mission. The pipeline is based on the Bayesian inference and provides effective temperature, surface gravity, metallicity, chemical abundances, and luminosity. The code in its more general version has a much wider range of potential applications. It can also provide masses, ages, and radii of stars and can be used with stellar types not targeted by the PLATO core program, such as red giants. We validate the code on a set of 27 benchmark stars that includes 19 FGK-type dwarfs, 6 GK-type subgiants, and 2 red giants. Our results suggest that combining various observables is the optimal approach, as this allows the degeneracies between different parameters to be broken and yields more accurate values of stellar parameters and more realistic uncertainties. For the PLATO core sample, we obtain a typical uncertainty of 27 (syst.) +/- 37 (stat.) K for T-eff, 0.00 +/- 0.01 dex for log g, 0.02 +/- 0.02 dex for metallicity [Fe/H], -0.01 +/- 0.03 R-circle dot for radii, -0.01 +/- 0.05 M-circle dot for stellar masses, and -0.14 +/- 0.63 Gyr for ages. We also show that the best results are obtained by combining the nu(max) scaling relation with stellar spectra. This resolves the notorious problem of degeneracies, which is particularly important for F-type stars.
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| 20. |
- Käpylä, Petri, et al.
(author)
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Sensitivity to luminosity, centrifugal force, and boundary conditions in spherical shell convection
- 2020
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In: Geophysical and Astrophysical Fluid Dynamics. - : Taylor & Francis. - 0309-1929 .- 1029-0419. ; 114:1-2, s. 8-34
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Journal article (peer-reviewed)abstract
- We test the sensitivity of hydrodynamic and magnetohydrodynamic turbulent convection simulations with respect to Mach number, thermal and magnetic boundary conditions, and the centrifugal force. We find that varying the luminosity, which also controls the Mach number, has only a minor effect on the large-scale dynamics. A similar conclusion can also be drawn from the comparison of two formulations of the lower magnetic boundary condition with either vanishing electric field or current density. The centrifugal force has an effect on the solutions, but only if its magnitude with respect to acceleration due to gravity is by two orders of magnitude greater than in the Sun. Finally, we find that the parameterisation of the photospheric physics, either by an explicit cooling term or enhanced radiative diffusion, is more important than the thermal boundary condition. In particular, runs with cooling tend to lead to more anisotropic convection and stronger deviations from the Taylor-Proudman state. In summary, the fully compressible approach taken here with the Pencil Code is found to be valid, while still allowing the disparate timescales to be taken into account.
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| 21. |
- Lee, A. Y., et al.
(author)
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Bilateral vs. ipsilateral venography as the primary efficacy outcome measure in thromboprophylaxis clinical trials: a systematic review
- 2004
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In: J Thromb Haemost. - 1538-7933. ; 2:10, s. 1752-9
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Journal article (peer-reviewed)abstract
- Contrast venography, in combination with symptomatic venous thromboembolism (VTE), is the standard efficacy outcome measure in clinical trials of thromboprophylaxis in major orthopedic surgery. It is uncertain whether performing bilateral venography offers any real advantage over venography of the operated leg alone. This study was undertaken to determine the risk of isolated contralateral deep vein thrombosis (DVT) following major orthopedic surgery and to evaluate whether bilateral venography, rather than venography on the operated leg alone, offers any gain in DVT detection and, thereby, improves efficiency in clinical study design. A systematic review of prospective studies that reported DVT incidence as the primary efficacy outcome based on mandatory bilateral venography in patients undergoing elective hip or knee arthroplasty or hip fracture repair was conducted. Based on the use of bilateral venography as a primary efficacy outcome measure, the incidence of any DVT is 16.7% following total hip replacement, 18.8% after hip fracture repair, and 33.8% after total knee replacement. While DVT risk in the operated leg varies depending on the type of surgery, the risk of isolated DVT in the non-operated leg is approximately 4% to 5% in all three procedures. By increasing the detection of any DVT, the use of bilateral venography reduces required sample size by 16% to 25% compared to ipsilateral venography. In clinical trials evaluating the efficacy of thromboprophylaxis in major orthopedic surgery, bilateral venography reduces the risk of undiagnosed DVT in the non-operated leg and improves the efficiency of study design by substantially reducing the sample size requirement.
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| 22. |
- Malewicz, Michal, et al.
(author)
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Essential role for DNA-PK-mediated phosphorylation of NR4A nuclear orphan receptors in DNA double-strand break repair
- 2011
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In: Genes & Development. - : Cold Spring Harbor Laboratory. - 0890-9369 .- 1549-5477. ; 25:19, s. 2031-2040
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Journal article (peer-reviewed)abstract
- DNA-dependent protein kinase (DNA-PK) is a central regulator of DNA double-strand break (DSB) repair; however, the identity of relevant DNA-PK substrates has remained elusive. NR4A nuclear orphan receptors function as sequence-specific DNA-binding transcription factors that participate in adaptive and stress-related cell responses. We show here that NR4A proteins interact with the DNA-PK catalytic subunit and, upon exposure to DNA damage, translocate to DSB foci by a mechanism requiring the activity of poly(ADP-ribose) polymerase-1 (PARP-1). At DNA repair foci, NR4A is phosphorylated by DNA-PK and promotes DSB repair. Notably, NR4A transcriptional activity is entirely dispensable in this function, and core components of the DNA repair machinery are not transcriptionally regulated by NR4A. Instead, NR4A functions directly at DNA repair sites by a process that requires phosphorylation by DNA-PK. Furthermore, a severe combined immunodeficiency (SCID)-causing mutation in the human gene encoding the DNA-PK catalytic subunit impairs the interaction and phosphorylation of NR4A at DSBs. Thus, NR4As represent an entirely novel component of DNA damage response and are substrates of DNA-PK in the process of DSB repair.
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| 23. |
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| 24. |
- Wen, Gen, et al.
(author)
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An ancestral variant of Secretogranin II confers regulation by PHOX2 transcription factors and association with hypertension
- 2007
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In: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 16:14, s. 1752-1764
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Journal article (peer-reviewed)abstract
- Granins regulate secretory vesicle formation in neuroendocrine cells and granin-derived peptides are co-released with neurotransmitters as modulatory signals at sympathetic sites. We report evidence for association between a regulatory polymorphism in Secretogranin II (SCG2) and hypertension in African-American subjects. The minor allele is ancestral in the human lineage and is associated with disease risk in two case-control studies and with elevated blood pressure in a separate familial study. Mechanistically, the ancestral allele acts as a transcriptional enhancer in cells that express endogenous Scg2, whereas the derived allele does not. ARIX (PHOX2A) and PHOX2B are identified as potential transactivating factors by oligonucleotide affinity chromatography and mass spectrometry and confirmed by chromatin immunoprecipitation. Each of these transcription factors preferentially binds the risk allele, both in vitro and in vivo. Population genetic considerations suggest positive selection of the protective allele within the human lineage. These results identify a common regulatory variation in SCG2 and implicate granin gene expression in the control of human blood pressure and susceptibility to hypertension.
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