Les nouveaux immortels : le succès des séries télévisées fantastiques destinées au public adolescent

Naissance du genre " fantastique pour adolescents " dans les séries télévisées des années 1990, représentation de cet âge confrontée au vieillissement des acteurs

CDKN1B/p27 regulates autophagy via the control of Ragulator and MTOR activity in amino acid-deprived cells

The tumor suppressor CDKN1B/p27Kip1 binds to and inhibits cyclin-CDK complexes in the nucleus, inducing cell cycle arrest. However, when in the cytoplasm, CDKN1B may promote tumorigenesis. Notably, cytoplasmic CDKN1B was reported to promote macroautophagy/autophagy in response to nutrient shortage by a previously unknown mechanism. In our recent work, we found that during prolonged amino acid starvation, CDKN1B promotes autophagy via an MTORC1-dependent pathway. A fraction of CDKN1B translocates to lysosomes, where it interacts with the Ragulator subunit LAMTOR1, preventing Ragulator assembly, which is required for MTORC1 activation in response to amino acids. Therefore, CDKN1B represses MTORC1 activity, leading to nuclear translocation of the transcription factor TFEB and activation of lysosomal function, enhancing starvation-induced autophagy flux and apoptosis. In contrast, cells lacking CDKN1B survive starvation despite reduced autophagy, due to elevated MTORC1 activation. These findings reveal that, by directly repressing MTORC1 activity, CDKN1B couples the cell cycle and cell growth machineries during metabolic stress

From vertex detectors to inner trackers with CMOS pixel sensors

The use of CMOS Pixel Sensors (CPS) for high resolution and low material vertex detectors has been validated with the 2014 and 2015 physics runs of the STAR-PXL detector at RHIC/BNL. This opens the door to the use of CPS for inner tracking devices, with 10-100 times larger sensitive area, which require therefore a sensor design privileging power saving, response uniformity and robustness. The 350 nm CMOS technology used for the STAR-PXL sensors was considered as too poorly suited to upcoming applications like the upgraded ALICE Inner Tracking System (ITS), which requires sensors with one order of magnitude improvement on readout speed and improved radiation tolerance. This triggered the exploration of a deeper sub-micron CMOS technology, Tower-Jazz 180 nm, for the design of a CPS well adapted for the new ALICE-ITS running conditions. This paper reports the R&D results for the conception of a CPS well adapted for the ALICE-ITS.Comment: 4 pages, 4 figures, VCI 2016 conference proceeding

Simulation of a Hybrid Optical/Radio/Acoustic Extension to IceCube for EeV Neutrino Detection

Astrophysical neutrinos at $\sim$EeV energies promise to be an interesting source for astrophysics and particle physics. Detecting the predicted cosmogenic (``GZK'') neutrinos at 10$^{16}$ - 10$^{20}$ eV would test models of cosmic ray production at these energies and probe particle physics at $\sim$100 TeV center-of-mass energy. While IceCube could detect $\sim$1 GZK event per year, it is necessary to detect 10 or more events per year in order to study temporal, angular, and spectral distributions. The IceCube observatory may be able to achieve such event rates with an extension including optical, radio, and acoustic receivers. We present results from simulating such a hybrid detector.Comment: 4 pages, 2 figures; to appear in the Proceedings of the 29th ICRC, Pune, Indi

Interface Engineering to Create a Strong Spin Filter Contact to Silicon

Integrating epitaxial and ferromagnetic Europium Oxide (EuO) directly on silicon is a perfect route to enrich silicon nanotechnology with spin filter functionality. To date, the inherent chemical reactivity between EuO and Si has prevented a heteroepitaxial integration without significant contaminations of the interface with Eu silicides and Si oxides. We present a solution to this long-standing problem by applying two complementary passivation techniques for the reactive EuO/Si interface: ($i$) an $in\:situ$ hydrogen-Si $(001)$ passivation and ($ii$) the application of oxygen-protective Eu monolayers --- without using any additional buffer layers. By careful chemical depth profiling of the oxide-semiconductor interface via hard x-ray photoemission spectroscopy, we show how to systematically minimize both Eu silicide and Si oxide formation to the sub-monolayer regime --- and how to ultimately interface-engineer chemically clean, heteroepitaxial and ferromagnetic EuO/Si $(001)$ in order to create a strong spin filter contact to silicon.Comment: 11 pages of scientific paper, 10 high-resolution color figures. Supplemental information on the thermodynamic problem available (PDF). High-resolution abstract graphic available (PNG). Original research (2016

Superlattice Patterns in Surface Waves

We report novel superlattice wave patterns at the interface of a fluid layer driven vertically. These patterns are described most naturally in terms of two interacting hexagonal sublattices. Two frequency forcing at very large aspect ratio is utilized in this work. A superlattice pattern ("superlattice-I") consisting of two hexagonal lattices oriented at a relative angle of 22^o is obtained with a 6:7 ratio of forcing frequencies. Several theoretical approaches that may be useful in understanding this pattern have been proposed. In another example, the waves are fully described by two superimposed hexagonal lattices with a wavelength ratio of sqrt(3), oriented at a relative angle of 30^o. The time dependence of this "superlattice-II" wave pattern is unusual. The instantaneous patterns reveal a time-periodic stripe modulation that breaks the 6-fold symmetry at any instant, but the stripes are absent in the time average. The instantaneous patterns are not simply amplitude modulations of the primary standing wave. A transition from the superlattice-II state to a 12-fold quasi-crystalline pattern is observed by changing the relative phase of the two forcing frequencies. Phase diagrams of the observed patterns (including superlattices, quasicrystalline patterns, ordinary hexagons, and squares) are obtained as a function of the amplitudes and relative phases of the driving accelerations.Comment: 15 pages, 14 figures (gif), to appear in Physica

Entropies, volumes, and Einstein metrics

We survey the definitions and some important properties of several asymptotic invariants of smooth manifolds, and discuss some open questions related to them. We prove that the (non-)vanishing of the minimal volume is a differentiable property, which is not invariant under homeomorphisms. We also formulate an obstruction to the existence of Einstein metrics on four-manifolds involving the volume entropy. This generalizes both the Gromov--Hitchin--Thorpe inequality and Sambusetti's obstruction.Comment: This is a substantial revision and expansion of the 2004 preprint, which I prepared in spring of 2010 and which has since been published. The version here is essentially the published one, minus the problems introduced by Springer productio

Trapped by the Entrapment.

Popliteal entrapment syndrome results from extrinsic compression of the popliteal artery by the surrounding musculotendinous structures and is a rare cause of limb ischaemia. The purpose of this report is to highlight potential mistakes in the management of popliteal entrapment. In 2000, a 23 year old man underwent a popliteal to popliteal artery bypass surgery for what was initially diagnosed as a traumatic popliteal artery thrombosis. After being initially lost to follow up for 13 years, this "unspecified traumatic" thrombosis led to several inappropriate endovascular and open procedures misinterpreted as being caused by late graft failure. These included thrombectomy, aneurysmorrhaphy, polytetrafluoroethylene covered stent graft, a redo femoropopliteal bypass, and bypass thrombolysis. The diagnosis was reached 19 years after the initial surgery, when the patient underwent a redo bypass using a retrogeniculate approach. An abnormal lateral insertion of the gastrocnemius muscle medial head, and its accessory slip, constricted the artery, and also involved the popliteal vein (Type V), thus explaining previous revascularisation failures. Surgery consisted of resecting the accessory slip and the aneurysmal bypass. The artery was reconstructed with the cephalic vein. The patient was discharged on clopidogrel 75 mg, with no further complication, and a patent bypass at six months. Based on post-operative imaging (duplex ultrasound and magnetic resonance imaging), with forced plantarflexion and dorsiflexion, asymptomatic popliteal entrapment was also present on the contralateral side. The finding of an isolated popliteal artery lesion in a young individual should be considered to be caused by popliteal artery entrapment, unless proven otherwise. Definitive surgical release of the popliteal artery should be favoured over other strategies