Protoplanetary Disk Masses from Radiative Transfer Modeling: A Case Study in Taurus

Measuring the masses of protoplanetary disks is crucial for understanding their planet-forming potential. Typically, dust masses are derived from (sub-)millimeter flux density measurements plus assumptions for the opacity, temperature, and optical depth of the dust. Here we use radiative transfer models to quantify the validity of these assumptions with the aim of improving the accuracy of disk dust mass measurements. We first carry out a controlled exploration of disk parameter space. We find that the disk temperature is a strong function of disk size, while the optical depth depends on both disk size and dust mass. The millimeter-wavelength spectral index can be significantly shallower than the naive expectation due to a combination of optical depth and deviations from the Rayleigh-Jeans regime. We fit radiative transfer models to the spectral energy distributions (SEDs) of 132 disks in the Taurus-Auriga region using a Markov chain Monte Carlo approach. We used all available data to produce the most complete SEDs used in any extant modeling study. We perform the fitting twice: first with unconstrained disk sizes and again imposing the disk size--brightness relation inferred for sources in Taurus. This constraint generally forces the disks to be smaller, warmer, and more optically thick. From both sets of fits, we find disks to be $\sim$1--5 times more massive than when derived using (sub-)millimeter measurements and common assumptions. With the uncertainties derived from our model fitting, the previously measured dust mass--stellar mass correlation is present in our study but only significant at the 2$\sigma$ level.Comment: 28 pages, 13 figures, accepted for publication in A

Sex differences in the trajectories to diagnosis of patients presenting with common somatic symptoms in primary care:an observational cohort study

Objective: Little insight exists into sex differences in diagnostic trajectories for common somatic symptoms. This study aims to quantify sex differences in the provided primary care diagnostic interventions for common somatic symptoms, as well as the consequences hereof for final diagnoses. Methods: In this observational cohort study, we used real-world clinical data from the Dutch Family Medicine Network (N = 34,268 episodes of care related to common somatic symptoms; 61,4% female). The association between patients' sex on the one hand, and diagnostic interventions and disease diagnoses on the other hand, were assessed using multilevel multiple logistic regression analyses. Structural equation modelling was used to estimate a mediation model with multiple parallel mediators to assess whether the fewer disease diagnoses given to female patients were mediated by the fewer diagnostic interventions female patients receive, compared to male patients. Results: Women received fewer physical examinations (OR = 0.84, 95%CI = 0.79-0.89), diagnostic imaging (OR = 0.92, 95%CI = 0.84-0.99) and specialist referrals (OR = 0.85, 95%CI = 0.79-0.91) than men, but more laboratory diagnostics (OR = 1.27, 95%CI = 1.19-1.35). Women received disease diagnoses less often than men for their common somatic symptoms (OR = 0.94, 95%CI = 0.89-0.98). Mediation analysis showed that the fewer disease diagnosis in female patients were mediated by the fewer diagnostic interventions conducted in women compared to men. Conclusion: This study shows that sex inequalities are present in primary care diagnostic trajectories of patients with common somatic symptoms and that these lead to unequal health outcomes in terms of diagnoses between women and men. FPs have to be aware of these inequalities to ensure equal high-quality care for all patients

Sex Differences in Incidence of Respiratory Symptoms and Management by General Practioners

Background: Differences between women and men play an important role in lung physiology and epidemiology of respiratory diseases, but also in the health care processes. Objective: To analyse sex differences in patients encountering their general practitioner (GP) with respiratory symptoms with regard to incidence, GP's management and final diagnoses. Methods: Retrospective cohort study, using data of the Dutch Practice Based Research Network. All patients who encountered their GP from 01-07-2013 until 30-06-2018 with a new episode of care starting with a reason for encounter in the respiratory category (R) of the ICPC-2 classification were included (n = 16 773). Multi-level logistic regression was used to analyse influence of patients' sex on management of GPs with adjustment for possible confounders. Results: We found a significant higher incidence of respiratory symptoms in women than in men: 230/1000 patient years [95% confidence interval (CI) 227-232] and 186/1000 patient years (95% CI 183-189), respectively. When presenting with cough, GPs are more likely to perform physical examination [odds ratio (OR) 1.22; 95% CI 1.11-1.35] and diagnostic radiology (OR 1.25; 95% CI 1.08-1.44), but less likely to prescribe medication (OR 0.88; 95% CI 0.82-0.95) in men. When visiting the GP with dyspnoea, men more often undergo diagnostic imaging (OR 1.32; 95% CI 1.05-1.66) and are more often referred to a specialist (OR 1.35; 95% CI 1.13-1.62). Conclusions: Women encounter their GP more frequently with respiratory symptoms than men and GPs perform more diagnostic investigations in men. We suggest more research in general practice focussing on sex differences and possible confounders

Adverse events associated with nifurtimox treatment for chagas disease in children and adults

Nifurtimox (NF) is one of the only two drugs currently available for Chagas disease (ChD) treatment. However, data on NF safety are scarce, and many physicians defer or refuse NF treatment because of concerns about drug tolerance. In a retrospective study of adverse drug reactions (ADRs) associated with NF treatment of ChD, children received NF doses of 10 to 15 mg/kg/day for 60 to 90 days, and adults received 8 to 10 mg/kg/day for 30 days. A total of 215 children (median age, 2.6 years; range, 0 to 17 years) and 105 adults (median age, 34 years; range, 18 to 57 years) were enrolled. Overall, 127/320 (39.7%) patients developed ADRs, with an incidence of 64/105 adults and 63/215 children (odds ratio [OR] = 3.7; 95% confidence interval [CI], 2.2 to 6.3). We observed 215 ADRs, 131 in adults (median, 2 events/patient; interquartile range for the 25th to 75th percentiles [IQR25-75], 1 to 3) and 84 in children (median, 1 event/patient; IQR25-75 = 1 to 1.5) (Padjusted, 0.001). ADRs were mainly mild and moderate. Severe ADRs were infrequent (1.2% in children and 0.9% in adults). Nutritional, central nervous, and digestive systems were the most frequently affected, without differences between groups. Treatment was discontinued in 31/320 (9.7%) patients without differences between groups. However, ADR-related discontinuations occurred more frequently in adults than in children (OR = 5.5, 95% CI = 1.5 to 24). Our study supports the safety of NF for ChD treatment. Delaying NF treatment due to safety concerns does not seem to be supported by the evidence. (This study has been registered in ClinicalTrials.gov under identifier NCT04274101)

Isolating Dust and Free-Free Emission in ONC Proplyds with ALMA Band 3 Observations

The Orion Nebula Cluster (ONC) hosts protoplanetary disks experiencing external photoevaporation by the cluster's intense UV field. These ``proplyds" are comprised of a disk surrounded by an ionization front. We present ALMA Band 3 (3.1 mm) continuum observations of 12 proplyds. Thermal emission from the dust disks and free-free emission from the ionization fronts are both detected, and the high-resolution (0.057") of the observations allows us to spatially isolate these two components. The morphology is unique compared to images at shorter (sub)millimeter wavelengths, which only detect the disks, and images at longer centimeter wavelengths, which only detect the ionization fronts. The disks are small ($r_d$ = 6.4--38 au), likely due to truncation by ongoing photoevaporation. They have low spectral indices ($\alpha \lesssim 2.1$) measured between Bands 7 and 3, suggesting the dust emission is optically thick. They harbor tens of Earth masses of dust as computed from the millimeter flux using the standard method, although their true masses may be larger due to the high optical depth. We derive their photoevaporative mass-loss rates in two ways: first, by invoking ionization equilibrium, and second using the brightness of the free-free emission to compute the density of the outflow. We find decent agreement between these measurements and $\dot M$ = 0.6--18.4 $\times$ 10$^{-7}$ $M_\odot$ yr$^{-1}$. The photoevaporation timescales are generally shorter than the $\sim$1 Myr age of the ONC, underscoring the known ``proplyd lifetime problem." Disk masses that are underestimated due to being optically thick remains one explanation to ease this discrepancy.Comment: 17 pages, 12 figures, accepted for publication in Ap

Community stigma and desired social distance towards people affected by leprosy in Chandauli District, India

Objective: To collect baseline data on community stigma against leprosy and leprosy-related knowledge and ideas, with a view to develop contextualised community education and stigma reduction interventions. The data will also be used to evaluate subsequent stigma-reducing interventions. Methods: Community members (n ¼ 371) in Chandauli District, India, were interviewed, using a knowledge questionnaire, the EMIC Community Stigma Scale (EMIC-CSS) and Social Distance Scale (SDS). In the latter two scales, a higher sum score indicates a higher level of stigmatizing and negative attitudes of community members towards leprosy-affected people. Linear and quantile regression analyses were applied to explore the relation between (sociodemographic) covariates and the level of negative attitudes. Results: Community members indicated that avoidance of people affected by leprosy, problems with (prospective) marital life, concealment, and shame and embarrassment are present. Linear regression showed that knowing people affected by leprosy and being a government employee significantly increased one’s mean EMIC-CSS score, whereas a higher level of education significantly decreased this. Additionally, community members reported a desire to create social distance between people affected by leprosy and their children. Quantile regression showed that increased leprosy-specific knowledge and religion were associated with significantly decreased SDS scores, whilst housewives had significantly increased SDS scores. Knowledge was poorest regarding the transmission and cause of leprosy: only 8·1% and 10·5% knew the correct route of transmission and cause of leprosy. Conclusion: The level of negative attitudes of the community towards leprosy is high in Chandauli District, which may affect many aspects of the lives of people affected by leprosy. Community members knew least about the transmission and cause of leprosy and these domains should, therefore, be considered when designing stigma-decreasing interventions