210 research outputs found
Interpretable detection of unstable smart TV usage from power state logs
Power state logs from smart TVs are collected in order to construct a time-series representation of their usage. Time-series that belong to a TV exhibiting instability problems are classified accordingly. To do so, an automated feature extraction approach is used, together with linear classification methods in order to realise interpretable classification decisions. A normalized true positive rate of 0.84 ± 0.10 is obtained for the classification. The normalized true negative rate equals 0.80 ± 0.03. The final model returns a regularity statistic called the Approximate Entropy as its most important feature
Nlrp6 promotes recovery after peripheral nerve injury independently of inflammasomes
Background: NOD-like receptors (Nlrs) are key regulators of immune responses during infection and autoimmunity. A subset of Nlrs assembles inflammasomes, molecular platforms that are activated in response to endogenous danger and microbial ligands and that control release of interleukin (IL)-1 beta and IL-18. However, their role in response to injury in the nervous system is less understood.
Methods: In this study, we investigated the expression profile of major inflammasome components in the peripheral nervous system (PNS) and explored the physiological role of different Nlrs upon acute nerve injury in mice.
Results: While in basal conditions, predominantly members of NOD-like receptor B (Nlrb) subfamily (NLR family, apoptosis inhibitory proteins (NAIPs)) and Nlrc subfamily (ICE-protease activating factor (IPAF)/NOD) are detected in the sciatic nerve, injury causes a shift towards expression of the Nlrp family. Sterile nerve injury also leads to an increase in expression of the Nlrb subfamily, while bacteria trigger expression of the Nlrc subfamily. Interestingly, loss of Nlrp6 led to strongly impaired nerve function upon nerve crush. Loss of the inflammasome adaptor apoptosis-associated speck-like protein containing a CARD (ASC) and effector caspase-1 and caspase-11 did not affect sciatic nerve function, suggesting that Nlrp6 contributed to recovery after peripheral nerve injury independently of inflammasomes. In line with this, we did not detect release of mature IL-1 beta upon acute nerve injury despite potent induction of pro-IL-1 beta and inflammasome components Nlrp3 and Nlrp1. However, Nlrp6 deficiency was associated with increased pro-inflammatory extracellular regulated MAP kinase (ERK) signaling, suggesting that hyperinflammation in the absence of Nlrp6 exacerbated peripheral nerve injury.
Conclusions: Together, our observations suggest that Nlrp6 contributes to recovery from peripheral nerve injury by dampening inflammatory responses independently of IL-1 beta and inflammasomes
Galactosylsphingamides : new α-GalCer analogues to probe the F’-pocket of CD1d
Invariant Natural Killer T-cells (iNKT-cells) are an attractive target for immune response modulation, as upon CD1d-mediated stimulation with KRN7000, a synthetic alpha-galactosylceramide, they produce a vast amount of cytokines. Here we present a synthesis that allows swift modification of the phytosphingosine side chain by amidation of an advanced methyl ester precursor. The resulting KRN7000 derivatives, termed alpha-galactosylsphingamides, were evaluated for their capacity to stimulate iNKT-cells. While introduction of the amide-motif in the phytosphingosine chain is tolerated for CD1d binding and TCR recognition, the studied alpha-galactosylsphingamides showed compromised antigenic properties
Diffeomorphic Registration of Images with Variable Contrast Enhancement
Nonrigid image registration is widely used to estimate
tissue deformations in highly deformable anatomies. Among
the existing methods, nonparametric registration algorithms
such as optical flow, or Demons, usually have the advantage of
being fast and easy to use. Recently, a diffeomorphic version
of the Demons algorithm was proposed. This provides the
advantage of producing invertible displacement fields, which
is a necessary condition for these to be physical. However,
such methods are based on the matching of intensities and
are not suitable for registering images with different contrast
enhancement. In such cases, a registration method based on the
local phase like the Morphons has to be used. In this paper, a
diffeomorphic version of the Morphons registration method is
proposed and compared to conventional Morphons, Demons,
and diffeomorphic Demons. The method is validated in the
context of radiotherapy for lung cancer patients on several
4D respiratory-correlated CT scans of the thorax with and without
variable contrast enhancement
Formalism for power spectral density estimation for non-identical and correlated noise using the null channel in Einstein Telescope
Several proposed gravitational wave interferometers have a triangular
configuration, such as the Einstein Telescope and the Laser Interferometer
Space Antenna. For such a configuration one can construct a unique null channel
insensitive to gravitational waves from all directions. We expand on earlier
work and describe how to use the null channel formalism to estimate the power
spectral density for the Einstein Telescope interferometers with non-identical
as well as correlated noise sources. The formalism is illustrated with two
examples in the context of the Einstein Telescope, with increasing degrees of
complexity and realism. By using known mixtures of noises we show the formalism
is mathematically correct and internally consistent. Finally we highlight
future research needed to use this formalism as an ingredient for a Bayesian
estimation framework.Comment: The results have been updated (10/10/2022). Please refer to this new
versio
Interpreting methane variations in the past two decades using measurements of CH4 mixing ratio and isotopic composition
The availability 13C-CH4 measurements from atmospheric samples has significantly improved in recent years, which allows the construction of time series spanning up to about 2 decades. We have used these measurements to investigate the cause of the methane growth rate decline since 1980, with a special focus on the period 1998–2006 when the methane growth came to a halt. The constraints
provided by the CH4 and 13C-CH4 measurements are used to construct hypothetical source and sink scenarios, which are translated into corresponding atmospheric concentrations using the atmospheric transport model TM3 for evaluation against the measurements. The base scenario, composed of anthropogenic emissions according to EDGAR 4.0, constant emissions from natural sources, and a constant atmospheric lifetime, overestimates the observed global growth rates of CH4 and 13C-CH4 by, respectively, 10 ppb yr−1 and
0.02‰yr−1 after the year 2000. It proves difficult to repair this inconsistency by modifying trends in emissions only, notably because a temporary reduction of isotopically light sources, such as natural wetlands, leads to a further increase of 13C-CH4. Furthermore, our results are difficult to reconcile with the estimated increase of 5 TgCH4 yr−1 in emissions from fossil fuel use in the period 2000–2005. On the other hand, we find that a moderate (less than 5% per decade) increase in the global OH concentration can bring the model in agreement with the measurements for plausible emission scenarios. This study demonstrates the value of global monitoring
of methane isotopes, and calls for further investigation into the role OH and anthropogenic emissions to further improve our understanding of methane variations in recent years.JRC.H.2-Air and Climat
Reactivity of Cobalt-Fullerene Complexes towards Deuterium
The adsorption of molecular deuterium (D2) onto charged cobalt-fullerene-complexes ConC60 + (n=1–8) is measured experimentally in a few-collision reaction cell. The reactivity is strongly size-dependent, hinting at clustering of the transition metal atoms on the fullerenes. Formation and desorption rate constants are obtained from the pressure-dependent deuterogenation curves. DFT calculations indeed find that this transition metal clustering is energetically more favorable than decorating the fullerene. For n=1, D2 is predicted to bind molecularly and for n=2 dissociative and molecular configurations are quasi-isoenergetic. For n=3–8, dissociation of D2 is thermodynamically preferred. However, reaching the ground state configuration with dissociated deuterium on the timescale of the experiment may be hindered by dissociation barriers.Fil: Vanbuel, Jan. Katholikie Universiteit Leuven; BélgicaFil: German, Estefania. Universidad de Valladolid; España. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Física del Sur. Universidad Nacional del Sur. Departamento de Física. Instituto de Física del Sur; ArgentinaFil: Libeert, Guillaume. Katholikie Universiteit Leuven; BélgicaFil: Veys, Koen. Katholikie Universiteit Leuven; BélgicaFil: Moens, Janni. Katholikie Universiteit Leuven; BélgicaFil: Alonso, Julio A.. Donostia International Physics Center; España. Universidad de Valladolid; EspañaFil: López, María J.. Universidad de Valladolid; EspañaFil: Janssens, Ewald. Katholikie Universiteit Leuven; Bélgic
A molecular switch in mouse CD1d modulates natural killer T cell activation by α-galactosylsphingamides
Type I natural killer T (NKT) cells are a population of innate like T lymphocytes that rapidly respond to α-GalCer presented by CD1d via the production of both pro- and anti-inflammatory cytokines. While developing novel α-GalCer analogs that were meant to be utilized as potential adjuvants because of their production of pro-inflammatory cytokines (Th1 skewers), we generated α-galactosylsphingamides (αGSA). Surprisingly, αGSAs are not potent antigens in vivo despite their strong T-cell receptor (TCR)–binding affinities. Here, using surface plasmon resonance (SPR), antigen presentation assays, and X-ray crystallography (yielding crystal structures of 19 different binary (CD1d-glycolipid) or ternary (CD1d-glycolipid-TCR) complexes at resolutions between 1.67 and 2.85 Å), we characterized the biochemical and structural details of αGSA recognition by murine NKT cells. We identified a molecular switch within murine (m)CD1d that modulates NKT cell activation by αGSAs. We found that the molecular switch involves a hydrogen bond interaction between Tyr-73 of mCD1d and the amide group oxygen of αGSAs. We further established that the length of the acyl chain controls the positioning of the amide group with respect to the molecular switch and works synergistically with Tyr-73 to control NKT cell activity. In conclusion, our findings reveal important mechanistic insights into the presentation and recognition of glycolipids with polar moieties in an otherwise apolar milieu. These observations may inform the development αGSAs as specific NKT cell antagonists to modulate immune responses
Technical Note: 4D cone-beam CT reconstruction from sparse-view CBCT data for daily motion assessment in pencil beam scanned proton therapy (PBS-PT)
Purpose: The number of pencil beam scanned proton therapy (PBS-PT) facilities equipped with cone-beam computed tomography (CBCT) imaging treating thoracic indications is constantly rising. To enable daily internal motion monitoring during PBS-PT treatments of thoracic tumors, we assess the performance of Motion-Aware RecOnstructiOn method using Spatial and Temporal Regularization (MA-ROOSTER) four-dimensional CBCT (4DCBCT) reconstruction for sparse-view CBCT data and a realistic data set of patients treated with proton therapy. Methods: Daily CBCT projection data for nine non-small cell lung cancer (NSCLC) patients and one SCLC patient were acquired at a proton gantry system (IBA Proteus® One). Four-dimensional CBCT images were reconstructed applying the MA-ROOSTER and the conventional phase-correlated Feldkamp-Davis-Kress (PC-FDK) method. Image quality was assessed by visual inspection, contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR), and the structural similarity index measure (SSIM). Furthermore, gross tumor volume (GTV) centroid motion amplitudes were evaluated. Results: Image quality for the 4DCBCT reconstructions using MA-ROOSTER was superior to the PC-FDK reconstructions and close to FDK images (median CNR: 1.23 [PC-FDK], 1.98 [MA-ROOSTER], and 1.98 [FDK]; median SNR: 2.56 [PC-FDK], 4.76 [MA-ROOSTER], and 5.02 [FDK]; median SSIM: 0.18 [PC-FDK vs FDK], 0.31 [MA-ROOSTER vs FDK]). The improved image quality of MA-ROOSTER facilitated GTV contour warping and realistic motion monitoring for most of the reconstructions. Conclusion: MA-ROOSTER based 4DCBCTs performed well in terms of image quality and appear to be promising for daily internal motion monitoring in PBS-PT treatments of (N)SCLC patients
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