Structures in surface-brightness profiles of LMC and SMC star clusters: evidence of mergers?

The LMC and SMC are rich in binary star clusters, and some mergers are expected. It is important to characterize single clusters, binary clusters and candidates to mergers. We selected a sample of star clusters in each Cloud with this aim. Surface photometry of 25 SMC and 22 LMC star clusters was carried with the ESO Danish 1.54 m telescope. 23 clusters were observed for the first time for these purposes. We fitted Elson, Fall and Freeman (1987, EFF) profiles to the data, deriving structural parameters, luminosities and masses. We also use isophotal maps to constrain candidates to cluster interactions.} {The structural parameters, luminosities and masses presented good agreement with those in the literature. Three binary clusters in the sample have a double profile. Four clusters (NGC 376, K 50, K 54 and NGC 1810) do not have companions and present as well important deviations from EFF profiles. The present sample contains blue and red Magellanic clusters. Extended EFF profiles were detected in some blue clusters. We find evidence that important deviations from the body of EFF profiles might be used as a tool to detect cluster mergers.Comment: 16 pages and 8 figures. Accepted by A&

Epigenetic Perturbations by Arg882-Mutated DNMT3A Potentiate Aberrant Stem Cell Gene-Expression Program and Acute Leukemia Development

DNA methyltransferase 3A (DNMT3A) is frequently mutated in hematological cancers; however, the underlying oncogenic mechanism remains elusive. Here, we report that DNMT3A mutational hotspot at Arg882 (DNMT3AR882H) cooperates with NRAS mutation to transform hematopoietic stem/progenitor cells and induce acute leukemia development. Mechanistically, DNMT3AR882H directly binds to and potentiates transactivation of stemness genes critical for leukemogenicity including Meis1, Mn1 and Hoxa gene cluster. DNMT3AR882H induces focal epigenetic alterations, including CpG hypomethylation and concurrent gain of active histone modifications, at cis-regulatory elements such as enhancers to facilitate gene transcription. CRISPR/Cas9-mediated ablation of a putative Meis1 enhancer carrying DNMT3AR882H-induced DNA hypomethylation impairs Meis1 expression. Importantly, DNMT3AR882H-induced gene expression programs can be repressed through Dot1l inhibition, providing an attractive therapeutic strategy for DNMT3A-mutated leukemias

Resolved Massive Star Clusters in the Milky Way and its Satellites: Brightness Profiles and a Catalogue of Fundamental Parameters

[Abridged]: We present a database of structural and dynamical properties for 153 spatially resolved star clusters (50 "young massive clusters" and 103 old globulars) in the Milky Way, the Large and Small Magellanic Clouds, and the Fornax dwarf spheroidal. This database complements and extends others in the literature, such as those of Harris, and Mackey & Gilmore. By fitting a number of models to the clusters' density profiles, we derive various characteristic surface brightnesses and radii; central potentials, velocity dispersions, and escape velocities; total luminosities, masses, and binding energies; phase-space densities and relaxation timescales; and ``kappa-space'' parameters. Population-synthesis models are used to predict intrinsic (B-V) colors, reddenings, and V-band mass-to-light ratios for the same 153 clusters plus another 63 globulars in the Milky Way, and we compare these predictions to the observed quantities where available. These results are intended to serve as the basis for future investigations of structural correlations and the fundamental plane of massive star clusters, including especially comparisons between the systemic properties of young and old clusters. We also address the question of what structural model fits each cluster best, and argue that the extended halos known to characterize many Magellanic Cloud clusters may be examples of the generic envelope structure of self-gravitating star clusters, not just transient features associated strictly with young age.Comment: Published in ApJS. 60 pages (more than half figures and tables) using emulateapj.sty. A full-resolution PDF version and complete, machine-readable tables can also be found at http://www.astro.le.ac.uk/~dm131/clusters.htm

Some Remarks on Talenti's Semigroup

Let X be a Banach space. Consider the family I(α) of linear continuous operators from X into itself, depending on the parameter α ≥ 0. Suppose that I(α1+α2)=I(α1)I(α2)∀α1, α2 ≥ 0 and I(0)=I (semigroupal property). Such a semigroup is said to be strongly continuous for α &gt; 0, if limh→0I(α+h)x =I(α)x, ∀x ∊ X.</jats:p

Nasopharyngeal cylindrical cell papilloma

Introduction: Cylindrical cell papillomas are rare tumours which usually arise in the sinonasal region.Case report: We report a case of a nasopharyngeal cylindrical cell papilloma in a 56-year-old man who presented with a four-month history of right-sided hearing loss, otalgia, vertigo and tinnitus. Investigation revealed a soft, nodular lesion obstructing the pharyngeal opening of the right eustachian tube; this was treated by wide endoscopic excision.Conclusion: Cylindrical cell papilloma is a possible cause of eustachian tube obstruction in adults. Effective treatment of these lesions usually requires wide endoscopic excision, in order not to miss coexistent carcinoma. Copyright © 2010 JLO (1984) Limited

A Rare Cause of Peripheral Facial Nerve Palsy: Chondromyxoid Fibroma of the Temporal Bone

Purpose:To report a rather rare entity of facial palsy due to chondromyxoid fibroma. The authors present a case along with clinico-pathological features, management, treatment options and follow-up.Methods:The authors present a case of a 29-year-old male who suffered from right facial weakness and numbness for a period of 6-months. imaging studies demonstrated a soft, locally invasive tumor, located mainly in the right temporal bone and extended extracranially.Results:A surgical procedure of local excision followed by cross-facial nerve grafting was performed.Conclusions:Diagnosis should be based on combination of histo-pathologic and radiographic findings, because of its histological similarities to chondrosarcoma. © 2022 Lippincott Williams and Wilkins. All rights reserved

Case Report Lingual Abscess in a Psychiatric Patient: A Case Report

We present a 46-year-old psychiatric patient presenting with a lingual abscess. This paper covers the epidemiology, clinical features, diagnosis, and differential diagnosis with a view to assisting emergency physicians in the timely recognition and management of this rare but potentially life-threatening condition

Liposarcoma of the nasopharynx: Diagnosis and management of a rare diagnostic entity

Liposarcoma is one of the most frequently occurring soft tissue sarcomas in adulthood. The majority of liposarcomas arise in the lower extremities and retroperitoneum, while the incidence of this tumor in the head and neck region is reported to be extremely low, comprising 1.8%-6.2% of all cases. Nasopharyngeal liposarcoma is exceptionally rare, with only three cases having been reported in the English literature. This paper presents a case of a nasopharyngeal liposarcoma, treated with endoscopic tumor debulking, followed by adjuvant chemotherapy and radiotherapy, and reviews the current literature with regard to diagnosis and management of such lesions. Most authors agree that the imaging modality of choice is magnetic resonance imaging. Although radiographic findings usually support diagnosis, the imaging characteristics of such lesions may considerably vary, depending on the histological subtype and the macroscopic appearance of the tumor. The treatment of choice is complete surgical excision when possible. Although the role of postoperative radiotherapy is not clearly defined, some authors support that radiotherapy might delay or prevent local recurrence. However, there is no adequate evidence that the combination of surgery and radiotherapy lowers the possibility of distant metastasis of the head and neck liposarcomas. The role of adjuvant or neoadjuvant chemotherapy still remains controversial. © Copyright 2012 George X. Papacharalampous et al