65 research outputs found
Modeling of smart materials with thermal effects: dynamic and quasi-static evolution
International audienceWe present a mathematical model for linear magneto-electro-thermo-elastic continua, as sensors and actuators can be thought of, and prove the well-posedness of the dynamic and quasi-static problems. The two proofs are accomplished, respectively, by means of the Hille-Yosida theory and of the Faedo-Galerkin method. A validation of the quasi-static hypothesis is provided by a nondimensionalization of the dynamic problem equations. We also hint at the study of the convergence of the solution to the dynamic problem to that to the quasi-static problem as a small parameter â the ratio of the largest propagation speed for an elastic wave in the body to the speed of light â tends to zero
Weigh Your Own Words: Improving Hate Speech Counter Narrative Generation via Attention Regularization
Recent computational approaches for combating online hate speech involve the
automatic generation of counter narratives by adapting Pretrained
Transformer-based Language Models (PLMs) with human-curated data. This process,
however, can produce in-domain overfitting, resulting in models generating
acceptable narratives only for hatred similar to training data, with little
portability to other targets or to real-world toxic language. This paper
introduces novel attention regularization methodologies to improve the
generalization capabilities of PLMs for counter narratives generation.
Overfitting to training-specific terms is then discouraged, resulting in more
diverse and richer narratives. We experiment with two attention-based
regularization techniques on a benchmark English dataset. Regularized models
produce better counter narratives than state-of-the-art approaches in most
cases, both in terms of automatic metrics and human evaluation, especially when
hateful targets are not present in the training data. This work paves the way
for better and more flexible counter-speech generation models, a task for which
datasets are highly challenging to produce.Comment: To appear at CS4OA workshop (INLG-SIGDial
Weigh Your Own Words: Improving Hate Speech Counter Narrative Generation via Attention Regularization
Recent computational approaches for combating online hate speech involve the automatic generation of counter narratives by adapting Pretrained Transformer-based Language Models (PLMs) with human-curated data. This process, however, can produce in-domain overfitting, resulting in models generating acceptable narratives only for hatred similar to training data, with little portability to other targets or to real-world toxic language. This paper introduces novel attention regularization methodologies to improve the generalization capabilities of PLMs for counter narratives generation. Overfitting to training-specific terms is then discouraged, resulting in more diverse and richer narratives. We experiment with two attention-based regularization techniques on a benchmark English dataset. Regularized models produce better counter narratives than state-of-the-art approaches in most cases, both in terms of automatic metrics and human evaluation, especially when hateful targets are not present in the training data. This work paves the way for better and more flexible counter-speech generation models, a task for which datasets are highly challenging to produce
ARGONAUTE2 cooperates with SWI/SNF complex to determine nucleosome occupancy at human Transcription Start Sites.
Argonaute (AGO) proteins have a well-established role in post-transcriptional regulation of gene expression as key component of the RNA silencing pathways. Recent evidence involves AGO proteins in mammalian nuclear processes such as transcription and splicing, though the mechanistic aspects of AGO nuclear functions remain largely elusive. Here, by SILAC-based interaction proteomics, we identify the chromatin-remodelling complex SWI/SNF as a novel AGO2 interactor in human cells. Moreover, we show that nuclear AGO2 is loaded with a novel class of Dicer-dependent short RNAs (sRNAs), that we called swiRNAs, which map nearby the Transcription Start Sites (TSSs) bound by SWI/SNF. The knock-down of AGO2 decreases nucleosome occupancy at the first nucleosome located downstream of TSSs in a swiRNA-dependent manner. Our findings indicate that in human cells AGO2 binds SWI/SNF and a novel class of sRNAs to establish nucleosome occupancy on target TSSs
Low Noise Opto-Electro-Mechanical Modulator for RF-to-Optical Transduction in Quantum Communications
In this work, we present an Opto-Electro-Mechanical Modulator (OEMM) for
RF-to-optical transduction realized via an ultra-coherent nanomembrane
resonator capacitively coupled to an rf injection circuit made of a
microfabricated read-out able to improve the electro-optomechanical
interaction. This device configuration can be embedded in a Fabry-Perot cavity
for electromagnetic cooling of the LC circuit in a dilution refrigerator
exploiting the opto-electro-mechanical interaction. To this aim, an optically
measured steady-state frequency shift of 380 Hz was seen with a polarization
voltage of 30 V and a -factor of the assembled device above at room
temperature. The rf-sputtered titanium nitride layer can be made
superconductive to develop efficient quantum~transducers.Comment: 14 pages, 8 figure
The cosmic web of dwarf galaxies in a warm versus cold dark matter universe: mock galaxies in CDM and WDM simulations
Using cosmological simulations, we show that the cosmic web of dwarf galaxies in a warm dark matter (WDM) universe, wherein low mass halo formation is heavily suppressed, is nearly indistinguishable to that of a cold dark matter (CDM) universe whose low mass halos are not seen because galaxy formation is suppressed below some threshold mass. Low mass warm dark matter halos are suppressed nearly equally in all environments. For example, WDM voids in the galaxy distribution are neither larger nor emptier than CDM voids, once normalized to the same total galaxy number density and assuming galaxy luminosity scales with halo mass. It is thus a challenge to find hints about the dark matter particle in the cosmic web of galaxies. However, if the scatter between dwarf galaxy luminosity and halo properties is large, low mass CDM halos would sometimes host bright galaxies thereby populating voids that would be empty in WDM. Future surveys that will capture the small scale clustering in the local volume could thus help determine whether the CDM problem of the over-abundance of small halos with respect to the number density of observed dwarf galaxies has a cosmological solution or an astrophysical solution
Probing deformed commutators with macroscopic harmonic oscillators
A minimal observable length is a common feature of theories that aim to merge
quantum physics and gravity. Quantum mechanically, this concept is associated
to a nonzero minimal uncertainty in position measurements, which is encoded in
deformed commutation relations. In spite of increasing theoretical interest,
the subject suffers from the complete lack of dedicated experiments and bounds
to the deformation parameters are roughly extrapolated from indirect
measurements. As recently proposed, low-energy mechanical oscillators could
allow to reveal the effect of a modified commutator. Here we analyze the free
evolution of high quality factor micro- and nano-oscillators, spanning a wide
range of masses around the Planck mass (), and compare it with a model of deformed dynamics.
Previous limits to the parameters quantifying the commutator deformation are
substantially lowered.Comment: 11 pages, 3 figures, reference adde
GTF2I dosage regulates neuronal differentiation and social behavior in 7q11.23 neurodevelopmental disorders
Copy number variations at 7q11.23 cause neurodevelopmental disorders with shared and opposite manifestations.
Deletion causes Williams-Beuren syndrome featuring hypersociability, while duplication causes 7q11.23
microduplication syndrome (7Dup), frequently exhibiting autism spectrum disorder (ASD). Converging evidence
indicates GTF2I as key mediator of the cognitive-behavioral phenotypes, yet its role in cortical development
and behavioral hallmarks remains largely unknown.We integrated proteomic and transcriptomic profiling
of patient-derived cortical organoids, including longitudinally at single-cell resolution, to dissect 7q11.23
dosageâdependent and GTF2I-specific disease mechanisms. We observed dosage-dependent impaired dynamics
of neural progenitor proliferation, transcriptional imbalances, and highly specific alterations in neuronal
output, leading to precocious excitatory neuron production in 7Dup, which was rescued by restoring physiological
GTF2I levels. Transgenic mice with Gtf2i duplication recapitulated progenitor proliferation and neuronal differentiation
defects alongside ASD-like behaviors. Consistently, inhibition of lysine demethylase 1 (LSD1), a
GTF2I effector, was sufficient to rescue ASD-like phenotypes in transgenic mice, establishing GTF2I-LSD1 axis
as a molecular pathway amenable to therapeutic intervention in ASD
PRISM (Polarized Radiation Imaging and Spectroscopy Mission): A White Paper on the Ultimate Polarimetric Spectro-Imaging of the Microwave and Far-Infrared Sky
PRISM (Polarized Radiation Imaging and Spectroscopy Mission) was proposed to
ESA in response to the Call for White Papers for the definition of the L2 and
L3 Missions in the ESA Science Programme. PRISM would have two instruments: (1)
an imager with a 3.5m mirror (cooled to 4K for high performance in the
far-infrared---that is, in the Wien part of the CMB blackbody spectrum), and
(2) an Fourier Transform Spectrometer (FTS) somewhat like the COBE FIRAS
instrument but over three orders of magnitude more sensitive. Highlights of the
new science (beyond the obvious target of B-modes from gravity waves generated
during inflation) made possible by these two instruments working in tandem
include: (1) the ultimate galaxy cluster survey gathering 10e6 clusters
extending to large redshift and measuring their peculiar velocities and
temperatures (through the kSZ effect and relativistic corrections to the
classic y-distortion spectrum, respectively) (2) a detailed investigation into
the nature of the cosmic infrared background (CIB) consisting of at present
unresolved dusty high-z galaxies, where most of the star formation in the
universe took place, (3) searching for distortions from the perfect CMB
blackbody spectrum, which will probe a large number of otherwise inaccessible
effects (e.g., energy release through decaying dark matter, the primordial
power spectrum on very small scales where measurements today are impossible due
to erasure from Silk damping and contamination from non-linear cascading of
power from larger length scales). These are but a few of the highlights of the
new science that will be made possible with PRISM.Comment: 20 pages Late
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