32 research outputs found

    Steep Balmer decrement in weak AGNs may be not caused by dust extinction: clues from low-luminosity AGNs and changing-look AGNs

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    The hydrogen Balmer decrement (e.g., Hα/Hβ\rm H\alpha/H\beta) is widely adopted as an indicator of the internal reddening of active galactic nuclei (AGNs). This is challenged by some low-luminosity AGNs (LLAGNs) and changing-look AGNs (CLAGNs), which have steep Balmer decrement but without strong evidence for absorption. We compile a sample of normal AGNs and CLAGNs with a wider distribution of bolometric Eddington ratio (λEdd=Lbol/LEdd\lambda_{\rm Edd}=L_{\rm bol}/L_{\rm Edd}) and find a strong negative correlation between Hα/Hβ\rm H\alpha/H\beta and λEdd\lambda_{\rm Edd}, which suggests that the Balmer decrement is also accretion-rate dependent. We further explore the Balmer decrement based on the photoionization model using the Cloudy code by considering spectral energy distribution (SED) from the accretion disk with different accretion rates (e.g., disk/corona and truncated disk at high and low Eddington ratios, respectively). Both the standard disk and truncated disk predict a negative correlation of Hα/HβλEdd\rm H\alpha/H\beta-\lambda_{\rm Edd}, where the relation is steeper in the case of the truncated disk. The negative correlations are also explored in two single CLAGNs. The measured negative correlation of Hα/Hβ\rm H\alpha/H\beta -- λEdd\lambda_{\rm Edd} is mainly caused by the lower responsivity (dlogLline/dlogLcont)({\rm dlog}L_{\rm line}/{\rm dlog}L_{\rm cont}) in Hα\rm H\alpha relative to that in Hβ\rm H\beta, due to the larger optical depth in the former. We propose that the steep Balmer decrements in low-Eddington-ratio AGNs (e.g., some Seyferts 1.5-1.9 and CLAGNs) are not simply caused by absorption but mainly caused by the relatively low flux of ionizing photons.Comment: 13 pages, 3 figures, Accepted for publication in The Astrophysical Journa

    Congenital insensitivity to pain associated with PRDM12 mutation: Two case reports and a literature review

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    Background:PRDM12 is a newly discovered gene responsible for congenital insensitivity to pain (CIP). Its clinical manifestations are various and not widely known.Methods: The clinical data of two infants diagnosed with CIP associated with PRDM12 mutation were collected. A literature review was performed, and the clinical characteristics of 20 cases diagnosed with a mutation of PRDM12 were summarized and analyzed.Results: Two patients had pain insensitivity, tongue and lip defects, and corneal ulcers. The genomic analysis results showed that variants of PRDM12 were detected in the two families. The case 1 patient carried heterozygous variations of c.682+1G > A and c.502C > T (p.R168C), which were inherited from her father and mother, respectively. We enrolled 22 patients diagnosed with CIP through a literature review together with our cases. There were 16 male (72.7%) and 6 female (27.3%) patients. The age of onset ranged from 6 months to 57 years. The prevalence of clinic manifestation was 14 cases with insensitivity to pain (63.6%), 19 cases with self-mutilation behaviors (86.4%), 11 cases with tongue and lip defects (50%), 5 cases with mid-facial lesions (22.7%), 6 cases with distal phalanx injury (27.3%), 11 cases of recurrent infection (50%), 3 cases (13.6%) with anhidrosis, and 5 cases (22.7%) with global developmental delay. The prevalence of ocular symptoms was 11 cases (50%) with reduced tear secretion, 6 cases (27.3%) with decreased corneal sensitivity, 7 cases (31.8%) with disappeared corneal reflexes, 5.5 cases (25%, 0.5 indicated a single eye) with corneal opacity, 5 cases (22.7%) with corneal ulceration, and 1 case (4.5%) with a corneal scar.Conclusion: The syndrome caused by PRDM12 mutation is a clinically distinct and diagnosable disease that requires joint multidisciplinary management to control the development of the disease and minimize the occurrence of complications

    Role of TNF-α in vascular dysfunction

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    Healthy vascular function is primarily regulated by several factors including EDRF (endothelium-dependent relaxing factor), EDCF (endothelium-dependent contracting factor) and EDHF (endothelium-dependent hyperpolarizing factor). Vascular dysfunction or injury induced by aging, smoking, inflammation, trauma, hyperlipidaemia and hyperglycaemia are among a myriad of risk factors that may contribute to the pathogenesis of many cardiovascular diseases, such as hypertension, diabetes and atherosclerosis. However, the exact mechanisms underlying the impaired vascular activity remain unresolved and there is no current scientific consensus. Accumulating evidence suggests that the inflammatory cytokine TNF (tumour necrosis factor)-α plays a pivotal role in the disruption of macrovascular and microvascular circulation both in vivo and in vitro. AGEs (advanced glycation end-products)/RAGE (receptor for AGEs), LOX-1 [lectin-like oxidized low-density lipoprotein receptor-1) and NF-κB (nuclear factor κB) signalling play key roles in TNF-α expression through an increase in circulating and/or local vascular TNF-α production. The increase in TNF-α expression induces the production of ROS (reactive oxygen species), resulting in endothelial dysfunction in many pathophysiological conditions. Lipid metabolism, dietary supplements and physical activity affect TNF-α expression. The interaction between TNF-α and stem cells is also important in terms of vascular repair or regeneration. Careful scrutiny of these factors may help elucidate the mechanisms that induce vascular dysfunction. The focus of the present review is to summarize recent evidence showing the role of TNF-α in vascular dysfunction in cardiovascular disease. We believe these findings may prompt new directions for targeting inflammation in future therapies

    Investigating Shared Genetic Basis Across Tourette Syndrome and Comorbid Neurodevelopmental Disorders Along the Impulsivity-Compulsivity Spectrum

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    Background Tourette syndrome (TS) is often found comorbid with other neurodevelopmental disorders across the impulsivity-compulsivity spectrum, with attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and obsessive-compulsive disorder (OCD) as most prevalent. This points to the possibility of a common etiological thread along an impulsivity-compulsivity continuum. Methods Investigating the shared genetic basis across TS, ADHD, ASD, and OCD, we undertook an evaluation of cross-disorder genetic architecture and systematic meta-analysis, integrating summary statistics from the latest genome-wide association studies (93,294 individuals, 6,788,510 markers). Results As previously identified, a common unifying factor connects TS, ADHD, and ASD, while TS and OCD show the highest genetic correlation in pairwise testing among these disorders. Thanks to a more homogeneous set of disorders and a targeted approach that is guided by genetic correlations, we were able to identify multiple novel hits and regions that seem to play a pleiotropic role for the specific disorders analyzed here and could not be identified through previous studies. In the TS-ADHD-ASD genome-wide association study single nucleotide polymorphism–based and gene-based meta-analysis, we uncovered 13 genome-wide significant regions that host single nucleotide polymorphisms with a high posterior probability for association with all three studied disorders (m-value > 0.9), 11 of which were not identified in previous cross-disorder analysis. In contrast, we also identified two additional pleiotropic regions in the TS-OCD meta-analysis. Through conditional analysis, we highlighted genes and genetic regions that play a specific role in a TS-ADHD-ASD genetic factor versus TS-OCD. Cross-disorder tissue specificity analysis implicated the hypothalamus-pituitary-adrenal gland axis in TS-ADHD-ASD. Conclusions Our work underlines the value of redefining the framework for research across traditional diagnostic categories.publishedVersio

    Genomewide Gene Expression Analysis to Investigate Symptom Onset and Exacerbation in Tourette Syndrome

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    Tourette Syndrome (TS) is a neurodevelopmental disorder that starts in childhood. It is marked by multiple motor and vocal tics and a fluctuating course with recurrent time periods of symptom exacerbation followed by symptom remission. TS is considered a disorder of complex etiology that involves the interaction of multiple genetic and environmental factors. Previous studies have implicated regulation of the immune system in TS patients, although this remains a matter of debate. Here we present a genome-wide gene expression study comparing data from TS patients at time points of symptom exacerbation and remission as well as upon symptom onset for newly diagnosed patients, with differentially gene expression analysis, co-expression analysis and pathway analysis. Although the fold change of each regulated gene was very mild, it is the first time that changes in the regulation of the immune system have been implicated at different time points in TS patients

    How does choice of residential community affect the social integration of rural migrants: insights from China

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    Abstract The construction of public space is a new and important way to integrate rural migrants into urban society. Existing studies mainly discussed the factors affecting the social integration of rural migrants from the micro-individual and macro-system levels. Still, they seldom analyzed the differences between rural migrants’ residential communities and the roles these differences play in their social integration, especially from the perspective of residential space. Based on the data of the 2014 China Migrants Dynamic Monitoring Survey, this paper systematically examines the impact of residential community selection on the social integration of rural migrants and its possible effects using OLS, 2SLS, CMP, omitted variable test method, and KHB mediating effect model. It is found that the choice of residential community has a significant positive impact on the social integration of rural migrants, and the social integration of rural migrants living in formal communities has increased by 2.44%-3.20%. To overcome the potential endogeneity problems and selection bias of the empirical model, the study further adopted an instrumental variable estimation approach, combined with the omitted variable method for robustness check; the results still revealed the positive effect of living in formal communities on the social integration of rural migrants. The heterogeneous results showed that living in formal communities has a greater effect on the social integration of women and older-generation rural migrants. The farther the migration range and the longer the residence time of rural migrants, the greater the effect of living in the formal community on their social integration. Further mechanism testing revealed that living in formal communities not only directly enhances the social integration of rural migrants but also indirectly improves their social integration through public resource allocation, human capital accumulation, social status screening, and social network expansion. The indirect effect of capital accumulation is even greater. Therefore, to accelerate the full integration of rural migrants into urban society and achieve real urbanization and citizenship, the study proposes that the government should scientifically plan the layout of rural migrants’ living space and the construction of supporting facilities

    Steep Balmer Decrement in Weak AGNs May Not Be Caused by Dust Extinction: Clues from Low-luminosity AGNs and Changing-look AGNs

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    The hydrogen Balmer decrement (e.g., H α /H β ) is widely adopted as an indicator of the internal reddening of active galactic nuclei (AGNs). This is challenged by some low-luminosity AGNs and changing-look AGNs (CLAGNs), which have steep Balmer decrement but without strong evidence for absorption. We compile a sample of normal AGNs and CLAGNs with a wider distribution of bolometric Eddington ratio ( λ _Edd = L _bol / L _Edd ) and find a strong negative correlation between H α /H β and λ _Edd , which suggests that the Balmer decrement is also accretion-rate dependent. We further explore the Balmer decrement based on the photoionization model using the Cloudy code by considering spectral energy distribution from the accretion disk with different accretion rates (e.g., disk/corona and truncated disk at high and low Eddington ratios, respectively). Both the standard disk and truncated disk predict a negative correlation of H α /H β – λ _Edd , where the relation is steeper in the case of the truncated disk. The negative correlations are also explored in two single CLAGNs. The measured negative correlation of H α /H β – λ _Edd is mainly caused by the lower responsivity (dlogLline/dlogLcont)(d\mathrm{log}{L}_{\mathrm{line}}/d\mathrm{log}{L}_{\mathrm{cont}}) in H α relative to that in H β due to the larger optical depth in the former. We propose that the steep Balmer decrements in low Eddington ratio AGNs (e.g., some Seyferts 1.5–1.9 and CLAGNs) are not simply caused by absorption but mainly caused by the relatively low flux of ionizing photons

    Iterative Refinement for Multi-source Visual Domain Adaptation

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