2,674 research outputs found

    Reverberation Mapping and the Physics of Active Galactic Nuclei

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    Reverberation-mapping campaigns have revolutionized our understanding of AGN. They have allowed the direct determination of the broad-line region size, enabled mapping of the gas distribution around the central black hole, and are starting to resolve the continuum source structure. This review describes the recent and successful campaigns of the International AGN Watch consortium, outlines the theoretical background of reverberation mapping and the calculation of transfer functions, and addresses the fundamental difficulties of such experiments. It shows that such large-scale experiments have resulted in a ``new BLR'' which is considerably different from the one we knew just ten years ago. We discuss in some detail the more important new results, including the luminosity-size-mass relationship for AGN, and suggest ways to proceed in the near future.Comment: Review article to appear in Astronomical Time Series, Proceedings of the Wise Observatory 25th Ann. Symposium. 24 pages including 7 figure

    Age-specific effects of childhood body mass index on multiple sclerosis risk

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    OBJECTIVE: Higher body mass index (BMI) during early life is thought to be a causal risk factor for multiple sclerosis (MS). We used longitudinal Mendelian randomisation (MR) to determine whether there is a critical window during which BMI influences MS risk. METHODS: Summary statistics for childhood BMI (n ~ 28,000 children) and for MS susceptibility were obtained from recent large genome-wide association studies (GWAS) (n = 14,802 MS, 26,703 controls). We generated exposure instruments for BMI during four non-overlapping age epochs (< 3 months, 3 months–1.5 years, 2–5 years, and 7–8 years) and performed MR using the inverse variance weighted method with standard sensitivity analyses. Multivariable MR was used to account for effects mediated via later-life BMI. RESULTS: For all age epochs other than birth, genetically determined higher BMI was associated with an increased liability to MS: Birth [Odds Ratio (OR) 0.81, 95% Confidence Interval (CI) 0.50–1.31, Number of Single-Nucleotide Polymorphisms (N(SNPs)) = 7, p = 0.39], Infancy (OR 1.18, 95% CI 1.04–1.33, N(SNPs) = 18, p = 0.01), Early childhood (OR 1.31, 95% CI 1.03–1.66, N(SNPs) = 4, p = 0.03), Later childhood (OR 1.34, 95% CI 1.08–1.66, N(SNPs) = 4, p = 0.01). Multivariable MR suggested that these effects may be mediated by effects on adult BMI. CONCLUSION: We provide evidence using MR that genetically determined higher BMI during early life is associated with increased MS risk. This effect may be driven by shared genetic architecture with later-life BMI. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00415-022-11161-4

    Clinical course, costs and predictive factors for response to treatment in carpal tunnel syndrome: The PALMS study protocol

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    Background Carpal tunnel syndrome (CTS) is the most common neuropathy of the upper limb and a significant contributor to hand functional impairment and disability. Effective treatment options include conservative and surgical interventions, however it is not possible at present to predict the outcome of treatment. The primary aim of this study is to identify which baseline clinical factors predict a good outcome from conservative treatment (by injection) or surgery in patients diagnosed with carpal tunnel syndrome. Secondary aims are to describe the clinical course and progression of CTS, and to describe and predict the UK cost of CTS to the individual, National Health Service (NHS) and society over a two year period. Methods/Design In this prospective observational cohort study patients presenting with clinical signs and symptoms typical of CTS and in whom the diagnosis is confirmed by nerve conduction studies are invited to participate. Data on putative predictive factors are collected at baseline and follow-up through patient questionnaires and include standardised measures of symptom severity, hand function, psychological and physical health, comorbidity and quality of life. Resource use and cost over the 2 year period such as prescribed medications, NHS and private healthcare contacts are also collected through patient self-report at 6, 12, 18 and 24 months. The primary outcome used to classify treatment success or failures will be a 5-point global assessment of change. Secondary outcomes include changes in clinical symptoms, functioning, psychological health, quality of life and resource use. A multivariable model of factors which predict outcome and cost will be developed. Discussion This prospective cohort study will provide important data on the clinical course and UK costs of CTS over a two-year period and begin to identify predictive factors for treatment success from conservative and surgical interventions

    Development and characterisation of microsatellite loci in Eucalyptus globulus (Myrtaceae)

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    Eucalyptus globulus Labill. is the premier hardwood plantation species in temperate regions of the world. We developed twelve E. globulus microsatellite loci for fingerprinting and future studies in genome mapping, gene flow and genetic diversity. The microsatellites were highly polymorphic in E. globulus (average number of alleles per locus, 17.8; average observed heterozygosity, 0.66). The loci were robust, amplifying in other Eucalyptus species, Corymbia and Angophora. The high variability and transferability of these molecular markers make them useful in E. globulus, as well as in many of the 700 species of Eucalyptus

    Rural to Urban Migration and Changes in Cardiovascular risk Factors in Tanzania: A Prospective Cohort Study.

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    High levels of rural to urban migration are a feature of most African countries. Our aim was to investigate changes, and their determinants, in cardiovascular risk factors on rural to urban migration in Tanzania. Men and women (15 to 59 years) intending to migrate from Morogoro rural region to Dar es Salaam for at least 6 months were identified. Measurements were made at least one week but no more than one month prior to migration, and 1 to 3 monthly after migration. Outcome measures included body mass index, blood pressure, fasting lipids, and self reported physical activity and diet. One hundred and three men, 106 women, mean age 29 years, were recruited and 132 (63.2%) followed to 12 months. All the figures presented here refer to the difference between baseline and 12 months in these 132 individuals. Vigorous physical activity declined (79.4% to 26.5% in men, 37.8% to 15.6% in women, p < 0.001), and weight increased (2.30 kg men, 2.35 kg women, p < 0.001). Intake of red meat increased, but so did the intake of fresh fruit and vegetables. HDL cholesterol increased in men and women (0.24, 0.25 mmoll-1 respectively, p < 0.001); and in men, not women, total cholesterol increased (0.42 mmoll-1, p = 0.01), and triglycerides fell (0.31 mmoll-1, p = 0.034). Blood pressure appeared to fall in both men and women. For example, in men systolic blood pressure fell by 5.4 mmHg, p = 0.007, and in women by 8.6 mmHg, p = 0.001. The lower level of physical activity and increasing weight will increase the risk of diabetes and cardiovascular disease. However, changes in diet were mixed, and may have contributed to mixed changes in lipid profiles and a lack of rise in blood pressure. A better understanding of the changes occurring on rural to urban migration is needed to guide preventive measures

    Genetic variation in angiotensin-converting enzyme 2 gene is associated with extent of left ventricular hypertrophy in hypertrophic cardiomyopathy

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    Hypertrophic cardiomyopathy, a common, inherited cardiac muscle disease, is primarily caused by mutations in sarcomeric protein-encoding genes and is characterized by overgrowth of ventricular muscle that is highly variable in extent and location. This variability has been partially attributed to locus and allelic heterogeneity of the disease-causing gene, but other factors, including unknown genetic factors, also modulate the extent of hypertrophy that develops in response to the defective sarcomeric functioning. Components of the renin-angiotensin-aldosterone system are plausible candidate hypertrophy modifiers because of their role in controlling blood pressure and biological effects on cardiomyocyte hypertrophy

    Recurrent Ascending Colon Cancer Manifesting as Inferior Vena cava Thrombus

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    We report an extremely rare case of recurrent ascending colon cancer manifesting as inferior vena cava (IVC) thrombus. A 77-year-old woman previously diagnosed with ascending colon cancer underwent right hemicolectomy with lymph node dissection. Though the tumor invaded the retroperitoneum and involved the right ovarian artery and vein, curative operation was performed. The patient took 5-FU p.o. Two and a half years later, tumor thrombus in the IVC extending into the right atrium was incidentally found and diagnosed as recurrence of colon cancer by biopsy. RF-induced hyperthermia using 5-FU and CDDP i.v. was immediately performed, but she died after 6 months because of multiple liver and pulmonary metastases. In treating colon cancers invading the retroperitoneum, it should be recalled that some cases recur as tumor thrombus in the IVC and that close follow-up is therefore necessary

    Impact of asymmetries on fuel performance in inertial confinement fusion

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    Low-mode asymmetries prevent effective compression, confinement, and heating of the fuel in inertial confinement fusion (ICF) implosions, and their control is essential to achieving ignition. Ion temperatures (Tion) in ICF experiments are inferred from the broadening of primary neutron spectra. Directional motion (flow) of the fuel at burn also impacts broadening and will lead to artificially inflated "Tion" values. Flow due to low-mode asymmetries is expected to give rise to line-of-sight variations in measured Tion. We report on intentionally asymmetrically driven experiments at the OMEGA laser facility designed to test the ability to accurately predict and measure line-of-sight differences in apparent Tion due to low-mode asymmetry-seeded flows. Contrasted to chimera and xrage simulations, the measurements demonstrate how all asymmetry seeds have to be considered to fully capture the flow field in an implosion. In particular, flow induced by the stalk that holds the target is found to interfere with the seeded asymmetry. A substantial stalk-seeded asymmetry in the areal density of the implosion is also observed
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