487 research outputs found
Scanning Tunneling Spectroscopy of the superconducting proximity effect in a diluted ferromagnetic alloy
We studied the proximity effect between a superconductor (Nb) and a diluted
ferromagnetic alloy (CuNi) in a bilayer geometry. We measured the local density
of states on top of the ferromagnetic layer, which thickness varies on each
sample, with a very low temperature Scanning Tunneling Microscope. The measured
spectra display a very high homogeneity. The analysis of the experimental data
shows the need to take into account an additional scattering mechanism. By
including in the Usadel equations the effect of the spin relaxation in the
ferromagnetic alloy, we obtain a good description of the experimental data.Comment: 7 pages, 6 figure
PI3P signaling regulates receptor sorting but not transport in the endosomal pathway
While evidence is accumulating that phosphoinositide signaling plays a crucial role in growth factor and hormone receptor down-regulation, this signaling pathway has also been proposed to regulate endosomal membrane transport and multivesicular endosome biogenesis. Here, we have followed the fate of the down-regulated EGF receptor (EGFR) and bulk transport (fluid phase) markers in the endosomal pathway in vivo and in vitro. We find that bulk transport from early to late endosomes is not affected after inhibition of the phosphatidylinositol-3-phosphate (PI3P) signaling pathway, but that the EGFR then remains trapped in early endosomes. Similarly, we find that hepatocyte growth factorâregulated tyrosine kinase substrate (Hrs) is not directly involved in bulk solute transport, but is required for EGFR sorting. These observations thus show that transport and sorting can be uncoupled in the endosomal pathway. They also show that PI3P signaling does not regulate the core machinery of endosome biogenesis and transport, but controls the sorting of down-regulated receptor molecules in early endosomes via Hrs
Reply to "Comment on "Domain Structure in a Superconducting Ferromagnet""
This short article is a reply to the comment from E.B. Sonin on our paper on
the domain structure in a superconducting ferromagnet published in Phys. Rev.
Lett..Comment: 1 page, accepted for publication in Phys. Rev. Let
The identification and prevalence of frailty in diabetes mellitus and association with clinical outcomes: a systematic review protocol
INTRODUCTION:Diabetes mellitus is common and growing in prevalence, and an increasing proportion of people with diabetes are living to older age. Frailty is, therefore, becoming an important concept in diabetes. Frailty is associated with older age and describes a state of increased susceptibility to decompensation in response to physiological stress. A range of measures have been used to quantify frailty. This systematic review aims to identify measures used to quantify frailty in people with diabetes (any type); to summarise the prevalence of frailty in diabetes; and to describe the relationship between frailty and adverse clinical outcomes in people with diabetes. METHODS AND ANALYSIS:Three electronic databases (Medline, Embase and Web of Science) will be searched from 2000 to November 2019 and supplemented by citation searching of relevant articles and hand searching of reference lists. Two reviewers will independently review titles, abstracts and full texts. Inclusion criteria include: (1) adults with any type of diabetes mellitus; (2) quantify frailty using any validated frailty measure; (3) report the prevalence of frailty and/or the association between frailty and clinical outcomes in people with diabetes; (4) studies that assess generic (eg, mortality, hospital admission and falls) or diabetes-specific outcomes (eg, hypoglycaemic episodes, cardiovascular events, diabetic nephropathy and diabetic retinopathy); (5) cross-sectional and longitudinal observational studies. Study quality will be assessed using the Newcastle-Ottawa Scale for observational studies. Clinical and methodological heterogeneity will be assessed, and a random effects meta-analysis performed if appropriate. Otherwise, a narrative synthesis will be performed. ETHICS AND DISSEMINATION:This manuscript describes the protocol for a systematic review of observational studies and does not require ethical approval. PROSPERO REGISTRATION NUMBER:CRD42020163109
From policy to pedagogy: widening the discourse and practice of the learning society in the European Union
This paper explores the policy turn of the learning society, and how the academic world is responding to new social and political demands. It highlights some of the criticisms levelled at the learning society, as well as the voices of support. The paper also showcases the European Language Portfolio and the Transferable Skills project as two examples of good practice.
Cet article examine le tournant de la politique de la socieÂŽteÂŽ du savoir ainsi que la reÂŽponse du monde intellectuel face aux nouvelles exigences sociales et politiques. Il met en lumie`re certaines des critiques souleveÂŽes par la socieÂŽteÂŽ du savoir ainsi que par
les voix favorables. Lâarticle sâappuie sur deux exemples pratiques, a` savoir le Portfolio EuropeÂŽen des Langues et le Project des CompeÂŽtences Transmissibles
Josephson Coupling and Fiske Dynamics in Ferromagnetic Tunnel Junctions
We report on the fabrication of Nb/AlO_x/Pd_{0.82}Ni_{0.18}/Nb
superconductor/insulator/ferromagnetic metal/superconductor (SIFS) Josephson
junctions with high critical current densities, large normal resistance times
area products, high quality factors, and very good spatial uniformity. For
these junctions a transition from 0- to \pi-coupling is observed for a
thickness d_F ~ 6 nm of the ferromagnetic Pd_{0.82}Ni_{0.18} interlayer. The
magnetic field dependence of the \pi-coupled junctions demonstrates good
spatial homogeneity of the tunneling barrier and ferromagnetic interlayer.
Magnetic characterization shows that the Pd_{0.82}Ni_{0.18} has an out-of-plane
anisotropy and large saturation magnetization, indicating negligible dead
layers at the interfaces. A careful analysis of Fiske modes provides
information on the junction quality factor and the relevant damping mechanisms
up to about 400 GHz. Whereas losses due to quasiparticle tunneling dominate at
low frequencies, the damping is dominated by the finite surface resistance of
the junction electrodes at high frequencies. High quality factors of up to 30
around 200 GHz have been achieved. Our analysis shows that the fabricated
junctions are promising for applications in superconducting quantum circuits or
quantum tunneling experiments.Comment: 15 pages, 9 figure
Microtubule-associated protein 6 mediates neuronal connectivity through Semaphorin 3E-dependent signalling for axonal growth.
Structural microtubule associated proteins (MAPs) stabilize microtubules, a property that was thought to be essential for development, maintenance and function of neuronal circuits. However, deletion of the structural MAPs in mice does not lead to major neurodevelopment defects. Here we demonstrate a role for MAP6 in brain wiring that is independent of microtubule binding. We find that MAP6 deletion disrupts brain connectivity and is associated with a lack of post-commissural fornix fibres. MAP6 contributes to fornix development by regulating axonal elongation induced by Semaphorin 3E. We show that MAP6 acts downstream of receptor activation through a mechanism that requires a proline-rich domain distinct from its microtubule-stabilizing domains. We also show that MAP6 directly binds to SH3 domain proteins known to be involved in neurite extension and semaphorin function. We conclude that MAP6 is critical to interface guidance molecules with intracellular signalling effectors during the development of cerebral axon tracts
Tmetoceratidae (Ammonitina) fauna from the Gerecse Mts (Hungary)
Abstract
Taxonomic and stratigraphic problems of the family Tmetoceratidae and the genera Dumortieria, Catulloceras, Cotteswoldia, Pleydellia and Tmetoceras included in it are briefly discussed. Fifteen species of Tmetoceratidae are described and illustrated from the Upper Toarcian-Aalenian ammonite assemblages of the Gerecse Mts (NE Transdanubian Range, Hungary). The fauna described here is closely allied to the Mediterranean Province of the Mediterranean-Caucasian Realm
Carbenic nitrile imines: Properties and reactivity
Structures and properties of nitrile imines were investigated computationally at B3LYP and CCSD(T) levels. Whereas NBO analysis at the B3LYP DFT level invariably predicts a propargylic electronic structure, CCSD(T) calculations permit a clear distinction between propargylic, allenic, and carbenic structures. Nitrile imines with strong IR absorptions above ca. 2150 cm-1 have propargylic structures with a CN triple bond (RCNNSiMe 3 and R2BCNNBR2), and those with IR absorptions below ca. 2150 cm-1 are allenic (HCNNH, PhCNNH, and HCNNPh). Nitrile imines lacking significant cumulenic IR absorptions at 1900-2200 cm -1 are carbenic (R-(C:)-N=N-RâČ). Electronegative but lone pair-donating groups NR2, OR, and F stabilize the carbenic form of nitrile imines in the same way they stabilize "normal" singlet carbenes, including N-heterocyclic carbenes. NBO analyses at the CCSD(T) level confirm the classification into propargylic, allenic, and carbenic reactivity types. Carbenic nitrile imines are predicted to form azoketenes 21 with CO, to form [2+2] and [2+4] cycloadducts and borane adducts, and to cyclize to 1H-diazirenes of the type 24 in mildly exothermic reactions with activation energies in the range 29-38 kcal/mol. Such reactions will be readily accessible photochemically and thermally, e.g., under the conditions of matrix photolysis and flash vacuum thermolysis
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