Joana Moitinho Oliveira

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Pancreatic β-cells play a central role in type 2 diabetes (T2D) development, which is characterized by the progressive decline of the functional β-cell mass that is associated mainly with increased β-cell apoptosis. Thus, understanding how to enhance survival of β-cells is key for the management of T2D. The insulin receptor substrate-2 (IRS-2) protein is(More)
Proinflammatory cytokines contribute to beta cell damage in type 1 diabetes in part through activation of endoplasmic reticulum (ER) stress. In rat beta cells, cytokine-induced ER stress involves NO production and consequent inhibition of the ER Ca2+ transporting ATPase sarco/endoplasmic reticulum Ca2+ pump 2 (SERCA2B). However, the mechanisms by which(More)
Insulin receptor substrate 2 (IRS2) is a widely expressed protein that regulates crucial biological processes including glucose metabolism, protein synthesis, and cell survival. IRS2 is part of the insulin - insulin-like growth factor (IGF) signaling pathway and mediates the activation of the phosphotidylinositol 3-kinase (PI3K)-Akt and the(More)
M16 (the Eagle Nebula) is a striking star forming region, with a complex morphology of gas and dust sculpted by the massive stars in NGC 6611. Detailed studies of the famous “elephant trunks” dramatically increased our understanding of the massive star feedback into the parent molecular cloud. A rich young stellar population (2−3 Myr) has been identified,(More)
During obesity, the increment in beta cell mass in response to the rising demand for insulin is essential to maintain normal glucose homeostasis. However, the precise cellular and molecular mechanisms involved in beta cell mass plasticity remain poorly understood. The Wnt signalling pathway has been suggested as one possible modulator of beta cell(More)
The present paper considers the propagation of sound in a cylindrical duct, with a wall section of finite length covered by an acoustic liner whose impedance is an arbitrary function of position. The cases of (i) uniform wall impedance, and wall impedance varying along the (ii) circumference or (iii) axis of the duct, or (iv) both simultaneously, are(More)
We present ESO/VLT spectra in the 2.9–4.1 μm range for a large sample of infrared stars in the Small Magellanic Cloud (SMC), mainly carbon stars, massive oxygen-rich Asymptotic Giant Branch (AGB) stars, and red supergiants. Strong emission from Polycyclic Aromatic Hyrdrocarbons (PAHs) is detected in the spectrum of the post-AGB object MSXSMC29. Water ice is(More)
We present new mid-infrared observations of objects in the vicinity of the O-star σOrionis, obtained with TIMMI-2 at ESO. By constraining their nearand mid-infrared spectral energy distributions, we established the nature of previously known IRAS sources and identified new mid-infrared sources as young stellar objects with circumstellar disks, likely(More)
We investigate dust production and stellar mass loss in the Galactic globular cluster NGC 362. Due to its close proximity to the Small Magellanic Cloud (SMC), NGC 362 was imaged with the IRAC and MIPS cameras onboard the Spitzer Space Telescope as part of the Surveying the Agents of Galaxy Evolution (SAGE-SMC) Spitzer Legacy program. We detect several(More)
We report on the discovery of a mid-infrared source at a projected distance of only 1200 AU from the O9.5V star σOrionis. The spatially resolved, fan-shaped morphology and the presence of an ionization front, as well as evidence in the spectrum for processed dust grains, all suggest that it is a proto-planetary disk being dispersed by the intense(More)