463 research outputs found
Nuclear basket protein ZC3HC1 and its yeast homolog Pml39p feature an evolutionary conserved bimodular construction essential for initial binding to NPC-anchored homologs of scaffold protein TPR
Proteins ZC3HC1 and TPR are construction elements of the nuclear pore complex (NPC)-attached nuclear basket (NB). NB-location of ZC3HC1 depends on TPR already occurring NPC-anchored, whereas additional TPR polypeptides are appended to the NB by ZC3HC1. The current study examined the molecular properties of ZC3HC1 that enable it to bind to the NB and TPR. We report the identification and definition of a nuclear basket-interaction domain (NuBaID) of HsZC3HC1 comprising two similarly built modules, both essential for the binding to the NB’s NPC-anchored HsTPR. Furthermore, we describe such a bimodular construction as evolutionarily conserved and exemplify the kinship of HsZC3HC1 by the NB- and DdTPR-interacting homolog of Dictyostelium discoideum and by characterizing protein Pml39 as the ZC3HC1 homolog in Saccharomyces cerevisiae. Among several properties shared by the different species’ homologs, we unveil the integrity of the bimodular NuBaID of ScPml39p as being essential for binding to the yeast’s NBs and its TPR homologs ScMlp1p and ScMlp2p, and we further present Pml39p as enabling interlinkage of Mlp1p subpopulations. In addition to phyla-specific features, we delineate the three species’ common NuBaID as the characterizing structural entity of a one-of-a-kind protein found not in all but likely most taxa of the eukaryotic realm
Sexual Robots: The Social-Relational Approach and the Concept of Subjective Reference
In this paper we propose the notion of “subjective reference” as a conceptual tool that explains how and why human-robot sexual interactions could reframe users approach to human-human sexual interactions. First, we introduce the current debate about Sexual Robotics, situated in the wider discussion about Social Robots, stating the urgency of a regulative framework. We underline the importance of a social-relational approach, mostly concerned about Social Robots impact in human social structures. Then, we point out the absence of a precise framework conceptualizing why Social Robots, and Sexual Robots in particular, may modify users’ sociality and relationality. Within a psychological framework, we propose to consider Sexual Robots as “subjective references”, namely objects symbolically referring to human subjects: we claim that, for the user experience, every action performed upon a Sexual Robot is symbolically directed toward a human subject, including degrading and violent practices. This shifting mechanism may transfer the user relational setting from human-robot interactions to human-human interactions
Magnetic interlayer coupling between ferromagnetic SrRuO layers through a SrIrO spacer
A key element to tailor the properties of magnetic multilayers is the
coupling between the individual magnetic layers. In case of skyrmion hosting
multilayers, coupling of skyrmions across the magnetic layers is highly
desirable. Here the magnetic interlayer coupling was studied in epitaxial
all-oxide heterostructures of ferromagnetic perovskite SrRuO layers
separated by spacers of the strong spin-orbit coupling oxide SrIrO. This
combination of oxide layers is being discussed as a potential candidate system
to host N\'{e}el skyrmions. First order reversal curve (FORC) measurements were
performed in order to distinguish between magnetic switching processes of the
individual layers and to disentangle the signal of soft magnetic impurities
from the samples signal. Additionally, FORC investigations enabled to
determine whether the coupling between the magnetic layers is ferromagnetic or
antiferromagnetic. The observed interlayer coupling strength was weak for all
the heterostructures, with SrIrO spacers between 2 monolayers and 12
monolayers thick.Comment: 22 page
MINSTED nanoscopy enters the Ångström localization range
We report all-optical, room-temperature localization of fluorophores with precision in the Ångström range. These precisions are attained in a STED microscope, by encircling the fluorophore with the low-intensity edge of the STED donut beam, while constantly increasing the absolute donut power. Individual fluorophores bound to a DNA strand are localized with σ = 4.7 Å, corresponding to a fraction of the fluorophore size, with only 2,000 detected photons. MINSTED fluorescence nanoscopy with single-digit nanometer resolution is exemplified by imaging nuclear pore complexes and the distribution of nuclear lamin in mammalian cells labeled by transient DNA hybridization. Since our experiments yield a localization precision σ = 2.3 Å, estimated for 10,000 detected photons, we anticipate that MINSTED will open up entirely new areas of application in the study of macromolecular complexes in cells
Origin of the hump anomalies in the Hall resistance loops of ultrathin SrRuO/SrIrO multilayers
The proposal that very small N\'eel skyrmions can form in SrRuO/SrIrO
epitaxial bilayers and that the electric field-effect can be used to manipulate
these skyrmions in gated devices strongly stimulated the recent research of
SrRuO heterostructures. A strong interfacial Dzyaloshinskii-Moriya
interaction, combined with the breaking of inversion symmetry, was considered
as the driving force for the formation of skyrmions in SrRuO/SrIrO
bilayers. Here, we investigated nominally symmetric heterostructures in which
an ultrathin ferromagnetic SrRuO layer is sandwiched between large
spin-orbit coupling SrIrO layers, for which the conditions are not
favorable for the emergence of a net interfacial Dzyaloshinskii-Moriya
interaction. Previously the formation of skyrmions in the asymmetric
SrRuO/SrIrO bilayers was inferred from anomalous Hall resistance loops
showing humplike features that resembled topological Hall effect contributions.
Symmetric SrIrO/SrRuO/SrIrO trilayers do not show hump anomalies in
the Hall loops. However, the anomalous Hall resistance loops of symmetric
multilayers, in which the trilayer is stacked several times, do exhibit the
humplike structures, similar to the asymmetric SrRuO/SrIrO bilayers.
The origin of the Hall effect loop anomalies likely resides in unavoidable
differences in the electronic and magnetic properties of the individual
SrRuO layers rather than in the formation of skyrmions
Watching videos together in social Virtual Reality: An experimental study on user’s QoE
In this paper, we describe a user study in which pairs of users watch a video trailer and interact with each other, using two social Virtual Reality (sVR) systems, as well as in a face-to-face condition. The sVR systems are: Facebook Spaces, based on puppet-like customized avatars, and a video-based sVR system using photo-realistic virtual user representations. We collect subjective and objective data to analyze users’ Quality of Experience (QoE) and compare their interaction in VR to that observed during the real-life scenario. Our results show that the experience delivered by the video-based sVR system is comparable with real-life settings, while the puppet-based avatars limit the perceived q
Identifying Ionic and Electronic Charge Transfer at Oxide Heterointerfaces
The ability to tailor oxide heterointerfaces has led to novel properties in low-dimensional oxide systems. A fundamental understanding of these properties is based on the concept of electronic charge transfer. However, the electronic properties of oxide heterointerfaces crucially depend on their ionic constitution and defect structure: ionic charges contribute to charge transfer and screening at oxide interfaces, triggering a thermodynamic balance of ionic and electronic structures. Quantitative understanding of the electronic and ionic roles regarding charge-transfer phenomena poses a central challenge. Here, the electronic and ionic structure is simultaneously investigated at the prototypical charge-transfer heterointerface, LaAlO3/SrTiO3. Applying in situ photoemission spectroscopy under oxygen ambient, ionic and electronic charge transfer is deconvoluted in response to the oxygen atmosphere at elevated temperatures. In this way, both the rich and variable chemistry of complex oxides and the associated electronic properties are equally embraced. The interfacial electron gas is depleted through an ionic rearrangement in the strontium cation sublattice when oxygen is applied, resulting in an inverse and reversible balance between cation vacancies and electrons, while the mobility of ionic species is found to be considerably enhanced as compared to the bulk. Triggered by these ionic phenomena, the electronic transport and magnetic signature of the heterointerface are significantly altered
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