The ArmazoNes high Dispersion Echelle Spectrograph (ANDES) is the optical and near-infrared high-resolution echelle spectrograph envisioned for the Extremely Large Telescope (ELT). We present a ...selection of science cases, supported by new calculations and simulations, where ANDES could enable major advances in the fields of stars and stellar populations. We focus on three key areas, including the physics of stellar atmospheres, structure, and evolution; stars of the Milky Way, Local Group, and beyond; and the star-planet connection. The key features of ANDES are its wide wavelength coverage at high spectral resolution and its access to the large collecting area of the ELT. These features position ANDES to address the most compelling questions and potentially transformative advances in stellar astrophysics of the decades ahead, including questions which cannot be anticipated today.
We present the baseline conceptual design of the Cassegrain U-Band Efficient Spectrograph (CUBES) for the Very Large Telescope. CUBES will provide unprecedented sensitivity for spectroscopy on a 8 – ...10 m class telescope in the ground ultraviolet (UV), spanning a bandwidth of ≥ 100 nm that starts at 300 nm, the shortest wavelength accessible from the ground. The design has been optimized for end-to-end efficiency and provides a spectral resolving power of
R
≥ 20000, that will unlock a broad range of new topics across solar system, Galactic and extraglactic astronomy. The design also features a second, lower-resolution (
R
∼
7000) mode and has the option of a fiberlink to the UVES instrument for simultaneous observations at longer wavelengths.
Here we present the optical, mechanical and software design of the various subsystems of the instrument after the Phase A study of the project. We discuss the expected performances for the layout choices and highlight some of the performance trade-offs considered to best meet the instrument top-level requirements. We also introduce the model-based system engineering approach used to organize and manage the project activities and interfaces, in the context that it is increasingly necessary to integrate such tools in the development of complex astronomical projects.
Satellite cells are muscle resident stem cells and are responsible for muscle regeneration. In this study we investigate the involvement of PKCstraight epsilon during muscle stem cell differentiation ...in vitro and in vivo . Here, we describe the identification of a previously unrecognized role for the PKCstraight epsilon-HMGA1 signaling axis in myoblast differentiation and regeneration processes. PKCstraight epsilon expression was modulated in the C2C12 cell line and primary murine satellite cells in vitro, as well as in an in vivo model of muscle regeneration. Immunohistochemistry and immunofluorescence, RT-PCR and shRNA silencing techniques were used to determine the role of PKCstraight epsilon and HMGA1 in myogenic differentiation. PKCstraight epsilon expression increases and subsequently re-localizes to the nucleus during skeletal muscle cell differentiation. In the nucleus, PKCstraight epsilon blocks Hmga1 expression to promote Myogenin and Mrf4 accumulation and myoblast formation. Following in vivo muscle injury, PKCstraight epsilon accumulates in regenerating, centrally-nucleated myofibers. Pharmacological inhibition of PKCstraight epsilon impairs the expression of two crucial markers of muscle differentiation, namely MyoD and Myogenin, during injury induced muscle regeneration. This work identifies the PKCstraight epsilon-HMGA1 signaling axis as a positive regulator of skeletal muscle differentiation. * PKCepsilon increases during myogenic differentiation of satellite cell. * PKCepsilon blocks Hmga1 expression to promote myogenic differentiation. * In vivo pharmacological inhibition of PKCepsilon impairs skeletal muscle regeneration.
CUBES phase a design overview Zanutta Alessio; Cristiani Stefano; Atkinson, David ...
Experimental astronomy,
01/2023, Letnik:
55, Številka:
1
Journal Article
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Odprti dostop
We present the baseline conceptual design of the Cassegrain U-Band Efficient Spectrograph (CUBES) for the Very Large Telescope. CUBES will provide unprecedented sensitivity for spectroscopy on a 8 – ...10 m class telescope in the ground ultraviolet (UV), spanning a bandwidth of ≥ 100 nm that starts at 300 nm, the shortest wavelength accessible from the ground. The design has been optimized for end-to-end efficiency and provides a spectral resolving power of R≥ 20000, that will unlock a broad range of new topics across solar system, Galactic and extraglactic astronomy. The design also features a second, lower-resolution (R∼ 7000) mode and has the option of a fiberlink to the UVES instrument for simultaneous observations at longer wavelengths.Here we present the optical, mechanical and software design of the various subsystems of the instrument after the Phase A study of the project. We discuss the expected performances for the layout choices and highlight some of the performance trade-offs considered to best meet the instrument top-level requirements. We also introduce the model-based system engineering approach used to organize and manage the project activities and interfaces, in the context that it is increasingly necessary to integrate such tools in the development of complex astronomical projects.
Insulin activates several processes potentially dangerous for the arterial wall and hyperinsulinemia might be atherogenic. However, other insulin effects are protective for the vessel wall and thus ...anti-atherogenic. Aim of this study was to investigate whether insulin effects on potentially pro-atherogenic and anti-atherogenic processes were differently affected in cells from insulin-resistant individuals.
We determined insulin effect on nitric oxide (NO) production and plasminogen activator inhibitor (PAI)-1 synthesis in 12 fibroblast strains obtained from skin biopsy samples of 6 insulin-sensitive (IS) (clamp M >7 mg/kg body weight per minute) and 6 insulin-resistant (IR) (clamp M <5 mg/kg body weight per minute) healthy volunteers. Insulin effects on NO release and Akt phosphorylation were significantly impaired in fibroblasts from IR as compared with IS individuals. Conversely, there was not any difference between IR and IS strains in insulin ability to increase PAI-1 antigen levels and, after 24-hour insulin incubation, PAI-1 mRNA increase in IR strains was only slightly less than in IS strains. Insulin ability to induce MAPK activation was also comparable in IR and IS cells.
We conclude that in cells from IR individuals, insulin action on anti-atherogenic processes, such as NO release, is impaired, whereas the hormone ability to stimulate atherogenic processes, such as PAI-1 release, is preserved.
Protein kinase Cepsilon (PKCstraight epsilon) exerts a well-known cardio-protective activity in ischemia-reperfusion injury and plays a pivotal role in stem cell proliferation and differentiation. ...Although many studies have been performed on physiological and morphological effects of PKCstraight epsilon mis-expression in cardiomyocytes, molecular information on the role of PKCstraight epsilon on early cardiac gene expression are still lacking. We addressed the molecular role of PKCstraight epsilon in cardiac cells using mouse cardiomyocytes and rat bone marrow mesenchymal stem cells. We show that PKCstraight epsilon is modulated in cardiac differentiation producing an opposite regulation of the cardiac genes NK2 transcription factor related, locus 5 (nkx2.5) and GATA binding protein 4 (gata4) both in vivo and in vitro. Phospho-extracellular regulated mitogen-activated protein kinase 1/2 (p-ERK1/2) levels increase in PKCstraight epsilon over-expressing cells, while pkcstraight epsilon siRNAs produce a decrease in p-ERK1/2. Indeed, pharmacological inhibition of ERK1/2 rescues the expression levels of both nkx2.5 and gata4, suggesting that a reinforced (mitogen-activated protein kinase) MAPK signaling is at the basis of the observed inhibition of cardiac gene expression in the PKCstraight epsilon over-expressing hearts. We demonstrate that PKCstraight epsilon is critical for cardiac cell early gene expression evidencing that this protein is a regulator that has to be fine tuned in precursor cardiac cells.PUBLICATION ABSTRACT
High-resolution absorption spectroscopy toward bright background sources has had a paramount role in understanding early galaxy formation, the evolution of the intergalactic medium and the ...reionisation of the Universe. However, these studies are now approaching the boundaries of what can be achieved at ground-based 8-10m class telescopes. The identification of primeval systems at the highest redshifts, within the reionisation epoch and even into the dark ages, and of the products of the first generation of stars and the chemical enrichment of the early Universe, requires observing very faint targets with a signal-to-noise ratio high enough to detect very faint spectral signatures. In this paper, we describe the giant leap forward that will be enabled by ANDES, the high-resolution spectrograph for the ELT, in these key science fields, together with a brief, non-exhaustive overview of other extragalactic research topics that will be pursued by this instrument, and its synergistic use with other facilities that will become available in the early 2030s.
The gravitationally lensed quasar J014516.6-094517 at z=2.719 has been observed with the ESPRESSO instrument at the ESO VLT to obtain high-fidelity spectra of the two images A and B with a resolving ...power R=70000. At the redshifts under investigation (2.1 < z < 2.7), the Lyman forests along the two sightlines are separated by sub-kiloparsec physical distances and exhibit a strong correlation. We find that the two forests are indistinguishable at the present level of signal-to-noise ratio and do not show any global velocity shift, with the cross-correlation peaking at \(\Delta v = 12 \pm 48\) m/s. The distribution of the difference in velocity of individual Lyman-\(\alpha\) features is compatible with a null average and a mean absolute deviation of 930 m/s. Significant differences in NHI column density are not detected, putting a limit to the RMS fluctuation in the baryon density on \(\leq 1\) proper kpc scales of \(\Delta \rho / \rho < 3\)%. On the other hand, metal lines show significant differences both in velocity structure and in column density. A toy model shows that the difference in velocity of the metal features between the two sightlines is compatible with the the motions of the baryonic component associated to dark matter halos of typical mass \(M\simeq 2\times 10^{10} M_\odot\), also compatible with the observed incidence of the metal systems. The present observations confirm the feasibility of the Sandage test of the cosmic redshift drift with high-fidelity spectroscopy of the Lyman forest of distant, bright quasars, but also provide an element of caution about the intrinsic noise associated to the usage of metal features for the same purpose.
![PKC[straight epsilon] as a ...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/0014-4827/small "PKC[straight epsilon] as a novel promoter of skeletal muscle differentiation and regeneration")
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![The role of PKC[epsilon]-de...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/0948-6143/small "The role of PKC[epsilon]-dependent signaling for cardiac differentiation")