6,542 research outputs found
Massive Star cluster formation under the microscope at z=6
We report on a superdense star-forming region with an effective radius (R_e)
smaller than 13 pc identified at z=6.143 and showing a star-formation rate
density \Sigma_SFR~1000 Msun/yr/kpc2 (or conservatively >300 Msun/yr/kpc2).
Such a dense region is detected with S/N>40 hosted by a dwarf extending over
440 pc, dubbed D1 (Vanzella et al. 2017b). D1 is magnified by a factor
17.4+/-5.0 behind the Hubble Frontier Field galaxy cluster MACS~J0416 and
elongated tangentially by a factor 13.2+/-4.0 (including the systematic
errors). The lens model accurately reproduces the positions of the confirmed
multiple images with a r.m.s. of 0.35", and the tangential stretch is well
depicted by a giant multiply-imaged Lya arc. D1 is part of an interacting
star-forming complex extending over 800 pc. The SED-fitting, the very blue
ultraviolet slope (\beta ~ -2.5, F(\lambda) ~ \lambda^\beta) and the prominent
Lya emission of the stellar complex imply that very young (< 10-100 Myr),
moderately dust-attenuated (E(B-V)<0.15) stellar populations are present and
organised in dense subcomponents. We argue that D1 (with a stellar mass of 2 x
10^7 Msun) might contain a young massive star cluster of M < 10^6 Msun and
Muv~-15.6 (or m_uv=31.1), confined within a region of 13 pc, and not dissimilar
from some local super star clusters (SSCs). The ultraviolet appearance of D1 is
also consistent with a simulated local dwarf hosting a SSC placed at z=6 and
lensed back to the observer. This compact system fits into some popular
globular cluster formation scenarios. We show that future high spatial
resolution imaging (e.g., E-ELT/MAORY-MICADO and VLT/MAVIS) will allow us to
spatially resolve light profiles of 2-8 pc.Comment: 21 pages, 14 figures, 1 table, MNRAS accepte
Clinical Features and Differential Diagnoses in Laryngeal Mucoepidermoid Carcinoma
Mucoepidermoid carcinoma is the most common malignant tumor of salivary glands. However, it is a rare entity in larynx. Laryngeal cases are frequently misdiagnosed with other malignancies and they are under-reported. So, recognizing the clinical and histological features of this tumor is essential. Laryngeal mucoepidermoid carcinoma can arise in supraglottis, glottis and subglottis. Generally, it presents as a submucosal mass; therefore, progressive symptoms without any identifiable lesion in laryngoscopy must be well considered. The prognosis is somehow dependent on the histological features. In high-grade tumors, recurrence is more common and radical surgery with radiotherapy is recommended. In this paper, we provide a thorough literature review on mucoepidermoid carcinoma in the larynx. The most important distinguishing features of mucoepidermoid carcinoma and its two major differential diagnoses (squamous cell carcinoma and adenosquamous carcinoma) are clearly stated and pitfalls in true diagnosis of this tumor are discussed
Well-Being of Lesbian, Gay, Bisexual Youth: The Influence of Rural and Urban Contexts on the Process of Building Identity and Disclosure
The study investigates how the territorial community can influence the individual and social well-being of lesbian, gay, bisexual (LGB) youth and especially the recognition of their feelings and the construction of their own identity as well as their needs to be socially recognized. This research focuses on the experiences of 30 LGB individuals (23 males and 7 females), with a mean age of 25.07 years (SD = 4,578), living in urban and rural areas of Southern Italy. Focalized open interviews were conducted, and the Grounded Theory Methodology, supported by the Atlas.ti 8.0 software, was used for data analysis. The textual material was first coded, and then codes were grouped into five macro-categories: Freedom of identity expression in the urban and rural context, identity construction and acceptance process, need of aggregation and identification with the LGB community, role of the interpersonal relationship in the process of identity acceptance, socio-cultural context, and LGB psychological well-being. The results showed a condition common to the two contexts that we can define as “ghettoization.” The young LGB is alone in the rural area due to a lack of places and people to identify with and greater social isolation. On the contrary, although there are more opportunities in the urban area, young people feel stigmatized and ghettoized because “their places” are frequented exclusively by the lesbian, gay, bisexual, transexual, queer (LGBTQ) community. The work will extensively discuss the limitations of the research, future proposals, and the practical implications of the results
Transcriptional Regulation of Glucose Metabolism: The Emerging Role of the HMGA1 Chromatin Factor
HMGA1 (high mobility group A1) is a nonhistone architectural chromosomal protein that functions mainly as a dynamic regulator of chromatin structure and gene transcription. As such, HMGA1 is involved in a variety of fundamental cellular processes, including gene expression, epigenetic regulation, cell differentiation and proliferation, as well as DNA repair. In the last years, many reports have demonstrated a role of HMGA1 in the transcriptional regulation of several genes implicated in glucose homeostasis. Initially, it was proved that HMGA1 is essential for normal expression of the insulin receptor (INSR), a critical link in insulin action and glucose homeostasis. Later, it was demonstrated that HMGA1 is also a downstream nuclear target of the INSR signaling pathway, representing a novel mediator of insulin action and function at this level. Moreover, other observations have indicated the role of HMGA1 as a positive modulator of the Forkhead box protein O1 (FoxO1), a master regulatory factor for gluconeogenesis and glycogenolysis, as well as a positive regulator of the expression of insulin and of a series of circulating proteins that are involved in glucose counterregulation, such as the insulin growth factor binding protein 1 (IGFBP1), and the retinol binding protein 4 (RBP4). Thus, several lines of evidence underscore the importance of HMGA1 in the regulation of glucose production and disposal. Consistently, lack of HMGA1 causes insulin resistance and diabetes in humans and mice, while variations in the HMGA1 gene are associated with the risk of type 2 diabetes and metabolic syndrome, two highly prevalent diseases that share insulin resistance as a common pathogenetic mechanism. This review intends to give an overview about our current knowledge on the role of HMGA1 in glucose metabolism. Although research in this field is ongoing, many aspects still remain elusive. Future directions to improve our insights into the pathophysiology of glucose homeostasis may include epigenetic studies and the use of "omics" strategies. We believe that a more comprehensive understanding of HMGA1 and its networks may reveal interesting molecular links between glucose metabolism and other biological processes, such as cell proliferation and differentiation
Long-term diabetic complications in elderly patients with variable levels of HMGA1 expression
Barley-ß-glucans reduce systemic inflammation, renal injury and aortic calcification through ADAM17 and neutral-sphingomyelinase2 inhibition
In chronic kidney disease (CKD), hyperphosphatemia-induced inflammation aggravates vascular calcification (VC) by increasing vascular smooth muscle cell (VSMC) osteogenic differentiation, ADAM17-induced renal and vascular injury, and TNFα-induction of neutral-sphingomyelinase2 (nSMase2) to release pro-calcifying exosomes. This study examined anti-inflammatory β-glucans efficacy at attenuating systemic inflammation in health, and renal and vascular injury favoring VC in hyperphosphatemic CKD. In healthy adults, dietary barley β-glucans (Bβglucans) reduced leukocyte superoxide production, inflammatory ADAM17, TNFα, nSMase2, and pro-aging/pro-inflammatory STING (Stimulator of interferon genes) gene expression without decreasing circulating inflammatory cytokines, except for γ-interferon. In hyperphosphatemic rat CKD, dietary Bβglucans reduced renal and aortic ADAM17-driven inflammation attenuating CKD-progression (higher GFR and lower serum creatinine, proteinuria, kidney inflammatory infiltration and nSMase2), and TNFα-driven increases in aortic nSMase2 and calcium deposition without improving mineral homeostasis. In VSMC, Bβglucans prevented LPS- or uremic serum-induced rapid increases in ADAM17, TNFα and nSMase2, and reduced the 13-fold higher calcium deposition induced by prolonged calcifying conditions by inhibiting osteogenic differentiation and increases in nSMase2 through Dectin1-independent actions involving Bβglucans internalization. Thus, dietary Bβglucans inhibit leukocyte superoxide production and leukocyte, renal and aortic ADAM17- and nSMase2 gene expression attenuating systemic inflammation in health, and renal injury and aortic calcification despite hyperphosphatemia in CKD.A grant to A.S.D. and M.J.M. from IRBLleida and Agrotecnio Research collaborative projects from the Consell Social at Lleida University supported initial work, Instituto de Salud Carlos III and co-funded by European Union (ERDF/FEDER) (FIS PI11/00259, PI14/01452, PI17/02181), Plan de Ciencia, Tecnología e Innovación 2013–2017 y 2018–2022 del Principado de Asturias (GRUPIN14-028, IDI-2018-000152), RedInRen from ISCIII (ISCIII-RETIC REDINREN RD16/0009). Investigator support included: NC-L by GRUPIN14-028 and IDI-2018-000152, LM-A by GRUPIN14-028, SP by FICYT; MVA and PV by Educational Grant 2 A/2015 from ERA-EDTA CKD-MBD Working Group; PV and AC by ERA-EDTA fellowships 2011 and 2012; JR-C by MINECO (“Juan de la Cierva” program, FJCI-2015-23849); A.S.D. by Asociación Investigación de Fisiología Aplicada. A.S.D. and M.J.M. are members of the Campus Iberus (Ebro Valley Campus of International Excellence)
Depressive Symptomology Predicts Nighttime Central Systolic Blood Pressure Dipping in Adults
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