HST astrometry in the Orion Nebula Cluster: census of low-mass runaways

We present a catalog of high-precision proper motions in the Orion Nebula Cluster (ONC), based on Treasury Program observations with the Hubble Space Telescope's (HST) ACS/WFC camera. Our catalog contains 2,454 objects in the magnitude range of $14.2<m_{\rm F775W}<24.7$, thus probing the stellar masses of the ONC from $\sim$0.4 $M_\odot$ down to $\sim$0.02 $M_\odot$ over an area of $\sim$550 arcmin$^2$. We provide a number of internal velocity dispersion estimates for the ONC that indicate a weak dependence on the stellar location and mass. There is good agreement with the published velocity dispersion estimates, although nearly all of them (including ours at $\sigma_{v,x}=0.94$ and $\sigma_{v,y}=1.25$ mas yr$^{-1}$) might be biased by the overlapping young stellar populations of Orion A. We identified 4 new ONC candidate runaways based on HST and the Gaia DR2 data, all with masses less than $\sim$1 $M_\odot$. The total census of known candidate runaway sources is 10 -- one of the largest samples ever found in any Milky Way open star cluster. Surprisingly, none of them has the tangential velocity exceeding 20 km s$^{-1}$. If most of them indeed originated in the ONC, it may compel re-examination of dynamical processes in very young star clusters. It appears that the mass function of the ONC is not significantly affected by the lost runaways.Comment: 16 pages, 10 figures, 5 tables. Accepted for publication in A

Вища математика. Ч.1. Диференціальне числення у прикладах та задачах

Викладено набір теоретичних та практичних тестів з диференціального числення функції однієї та багатьох змінних. Докладні відповіді, вказівки, розв’язання типових завдань та достатня кількість прикладів для самостійної роботи дозволяють використовувати посібник для всіх видів занять

HST survey of the Orion Nebula Cluster in the H2_2O 1.4 μ\mum absorption band: I. A census of substellar and planetary mass objects

In order to obtain a complete census of the stellar and sub-stellar population, down to a few M$_{Jup}$ in the $\sim1$ Myr old Orion Nebula Cluster, we used the infrared channel of the Wide Field Camera 3 of the Hubble Space Telescope with the F139M and F130N filters. These bandpasses correspond to the $1.4 \mu$m H$_2$O absorption feature and an adjacent line-free continuum region. Out of $4,504$ detected sources, $3,352$ (about $75\%$) appear fainter than m$_{130}=14$ (Vega mag) in the F130N filter, a brightness corresponding to the hydrogen-burning limit mass (M$\simeq 0.072 M_\odot$) at $\sim 1$ Myr. Of these, however, only $742$ sources have a negative F130M-139N color index, indicative of the presence of H$_2$O vapor in absorption, and can therefore be classified as bona-fide M and L dwarfs, with effective temperatures T$\lesssim 2850$ K at an assumed $1$ Myr cluster age. On our color-magnitude diagram, this population of sources with H$_2$O absorption appears clearly distinct from the larger background population of highly reddened stars and galaxies with positive F130M-F139N color index, and can be traced down to the sensitivity limit of our survey, m$_{130}\simeq 21.5$, corresponding to a $1$ Myr old $\simeq 3$M$_{Jup}$, planetary mass object under about 2 magnitudes of visual extinction. Theoretical models of the BT-Settl family predicting substellar isochrones of $1, 2$ and $3$ Myr (down to $\sim 1$M$_{Jup}$) fail to reproduce the observed H$_2$O color index at M$\lesssim 20$M$_{Jup}$. We perform a Bayesian analysis to determine extinction, mass and effective temperature of each sub-stellar member of our sample, together with its membership probability.Comment: Accepted for publication in the Astrophysical Journal. The resolution of several figures has been downgraded to comply with the size limit of arXiv submission

Duloxetine in panic disorder with somatic gastric pain

Panic disorder is the most common type of anxiety disorder, and its most common expression is panic attacks characterized with sudden attacks of anxiety with numerous symptoms, including palpitations, tachycardia, tachypnea, nausea, and vertigo: ie, cardiovascular, gastroenterologic, respiratory, and neuro-otologic symptoms. In clinical practice, panic disorder manifests with isolated gastroenteric or cardiovascular symptoms, requiring additional clinical visits after psychiatric intervention. The first-line treatment for anxiety disorders, and in particular for panic disorder, is the selective serotonin reuptake inhibitors. However, these drugs can have adverse effects, including sexual dysfunction, increased bodyweight, and abnormal bleeding, that may be problematic for some patients. Here we report the case of a 29-year-old Caucasian woman affected by panic disorder with agoraphobia who was referred to our clinic for recurrent gastroenteric panic symptoms. The patient reported improvement in her anxiety symptoms and panic attacks while on a selective serotonin reuptake inhibitor, but not in her gastric somatic problems, so the decision was taken to start her on duloxetine, a serotonin-norepinephrine reuptake inhibitor. After 6 months of treatment, the patient achieved complete remission of her gastric and panic-related symptoms, and was able to stop triple gastric therapy. Other authors have hypothesized and confirmed that duloxetine has greater initial noradrenergic effects than venlafaxine and is effective in patients with panic disorder. This case report underscores the possibility of tailoring therapeutic strategies for the gastroenteric expression of panic disorder

Post-Infectious Disorders of Gut-Brain Interaction: A brainstorming story

We read with great interest the study “Prolonged gastrointestinal manifestations after recovery from COVID-19” by Elmunzer et al, which reported on the high prevalence of disorders of gut–brain interaction (DGBI) in patients recovering from severe coronavirus disease 2019 (COVID-19) infection. Persistent DGBIs were associated with both the initial severity of the gastrointestinal symptoms and psychological distress, suggestive of posttraumatic stress disorder (PTSD)

Exploring the genetics of irritable bowel syndrome: A GWA study in the general population and replication in multinational case-control cohorts

OBJECTIVE: IBS shows genetic predisposition, but adequately powered gene-hunting efforts have been scarce so far. We sought to identify true IBS genetic risk factors by means of genome-wide association (GWA) and independent replication studies. DESIGN: We conducted a GWA study (GWAS) of IBS in a general population sample of 11\u2005326 Swedish twins. IBS cases (N=534) and asymptomatic controls (N=4932) were identified based on questionnaire data. Suggestive association signals were followed-up in 3511 individuals from six case-control cohorts. We sought genotype-gene expression correlations through single nucleotide polymorphism (SNP)-expression quantitative trait loci interactions testing, and performed in silico prediction of gene function. We compared candidate gene expression by real-time qPCR in rectal mucosal biopsies of patients with IBS and controls. RESULTS: One locus at 7p22.1, which includes the genes KDELR2 (KDEL endoplasmic reticulum protein retention receptor 2) and GRID2IP (glutamate receptor, ionotropic, delta 2 (Grid2) interacting protein), showed consistent IBS risk effects in the index GWAS and all replication cohorts and reached p=9.31 710(-6) in a meta-analysis of all datasets. Several SNPs in this region are associated with cis effects on KDELR2 expression, and a trend for increased mucosal KDLER2 mRNA expression was observed in IBS cases compared with controls. CONCLUSIONS: Our results demonstrate that general population-based studies combined with analyses of patient cohorts provide good opportunities for gene discovery in IBS. The 7p22.1 and other risk signals detected in this study constitute a good starting platform for hypothesis testing in future functional investigations. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions

Binge Eating Disorder and Body Uneasiness

Debate continues regarding the nosological status of binge eating disorder (BED) and the specific diagnostic criteria, including whether, like anorexia nervosa and bulimia nervosa, it should be characterized by body image disturbances in addition to abnormal eating behaviour. The aims of this article are: a) to concisely review the main points of the literature that has developed on diagnosis and treatment (especially pharmacological) of BED and b) to present the results of an original research on body image in obese patients with BED. The study was aimed to verify the following hypothesis: in persons with obesity, BED is associated with greater body uneasiness independently of some possible modulating factors. We studied a clinical sample of 159 (89 females and 70 males) adult obese patients who fulfilled DSM-IV-TR diagnostic criteria for BED matched to 159 non-BED obese patients for gender, ethnicity, BMI class, age, weight, stature, onset age of obesity, education level, and marital status. We used the Body Uneasiness Test (BUT), a valuable multidimensional tool for the clinical assessment of body uneasiness in subjects suffering from eating disorders and/or obesity. Obese patients with BED reported higher scores than non-BED patients in the General Severity Index (BUT-A GSI) and in every BUT-A subscale. All differences were statistically significant in both sexes. As expected women obtained higher scores than men. According to some other studies, our findings suggest that a negative body image should be included among diagnostic criteria for BED. Consequently, treatment should be focused not simply on eating behaviour and outcome studies should evaluate changes of body image as well