518 research outputs found
Russian blues reveal the limits of language influencing colour discrimination
Chromatic stimuli across a boundary of basic colour categories (BCCs; e.g. blue and green) are discriminated faster than colorimetrically equidistant colours within a given category. Russian has two BCCs for blue, sinij âdark blueâ and goluboj âlight blueâ. These language-specific BCCs were reported to enable native Russian speakers to discriminate cross-boundary dark and light blues faster than English speakers (Winawer et al., 2007, PNAS, 4, 7780â7785). We re-evaluated this finding in two experiments that employed identical tasks as in the cited study. In Experiment 1, Russian and English speakers categorised colours as sinij/goluboj or dark blue/light blue respectively; this was followed by a colour discrimination task. In Experiment 2, Russian speakers initially performed the discrimination task on sinij/goluboj and goluboj/zelĂ«nyj âgreenâ sets. They then categorised these colours in three frequency contexts with each stimulus presented: (i) an equal number of times (unbiased); more frequent (ii) either sinij or goluboj; (iii) either goluboj or zelĂ«nyj. We observed a boundary response speed advantage for goluboj/zelĂ«nyj but not for sinij/goluboj. The frequency bias affected only the sinij/goluboj boundary such that in a lighter context, the boundary shifted towards lighter shades, and vice versa. Contrary to previous research, our results show that in Russian, stimulus discrimination at the lightness-defined blue BCC boundary is not reflected in processing speed. The sinij/goluboj boundary did have a sharper categorical transition than the dark blue/light blue boundary, but it was also affected by frequency and order biases, demonstrating that âRussian bluesâ are less well-structured than previously thought
Task and spatial frequency modulations of object processing: an EEG study.
Visual object processing may follow a coarse-to-fine sequence imposed by fast processing of low spatial frequencies (LSF) and slow processing of high spatial frequencies (HSF). Objects can be categorized at varying levels of specificity: the superordinate (e.g. animal), the basic (e.g. dog), or the subordinate (e.g. Border Collie). We tested whether superordinate and more specific categorization depend on different spatial frequency ranges, and whether any such dependencies might be revealed by or influence signals recorded using EEG. We used event-related potentials (ERPs) and time-frequency (TF) analysis to examine the time course of object processing while participants performed either a grammatical gender-classification task (which generally forces basic-level categorization) or a living/non-living judgement (superordinate categorization) on everyday, real-life objects. Objects were filtered to contain only HSF or LSF. We found a greater positivity and greater negativity for HSF than for LSF pictures in the P1 and N1 respectively, but no effects of task on either component. A later, fronto-central negativity (N350) was more negative in the gender-classification task than the superordinate categorization task, which may indicate that this component relates to semantic or syntactic processing. We found no significant effects of task or spatial frequency on evoked or total gamma band responses. Our results demonstrate early differences in processing of HSF and LSF content that were not modulated by categorization task, with later responses reflecting such higher-level cognitive factors
Total Electron Temperature Derived from Quasi-Thermal Noise Spectroscopy In the Pristine Solar Wind: Parker Solar Probe Observations
The Quasi-thermal noise (QTN) technique is a reliable tool to yield accurate
measurements of the electron parameters in the solar wind. We apply this method
on Parker Solar Probe (PSP) observations to derive the total electron
temperature () from the linear fit of the high-frequency part of the QTN
spectra acquired by the RFS/FIELDS instrument, and present a combination of
12-day period of observations around each perihelion from Encounter One (E01)
to Ten (E10) (with E08 not included) with the heliocentric distance varying
from about 13 to 60 solar radii (). We find that the total electron
temperature decreases with the distance as , which is much
slower than adiabatic. The extrapolated based on PSP observations is
consistent with the exospheric solar wind model prediction at 10
, Helios observations at 0.3 AU and Wind observations at 1 AU.
Also, , extrapolated back to 10 , is almost the same as the
strahl electron temperature (measured by SPAN-E) which is considered to
be closely related to or even almost equal to the coronal electron temperature.
Furthermore, the radial profiles in the slower solar wind (or flux tube
with larger mass flux) are steeper than those in the faster solar wind (or flux
tube with smaller mass flux). More pronounced anticorrelated - is
observed when the solar wind is slower and closer to the Sun.Comment: 10 pages, 7 figures, and Astronomy & Astrophysics Accepte
The Standard Model Prediction of the Muon Anomalous Magnetic Moment
This article reviews and updates the Standard Model prediction of the muon
g-2. QED, electroweak and hadronic contributions are presented, and open
questions discussed. The theoretical prediction deviates from the present
experimental value by 2-3 standard deviations, if e+e- annihilation data are
used to evaluate the leading hadronic term.Comment: 30 pages, 8 figures. v2: Updated version to appear in J.Phys.G.
Comments and references added, typo corrected in eq.(17
Secure Code Update for Embedded Devices via Proofs of Secure Erasure
Abstract. Remote attestation is the process of verifying internal state of a remote embedded device. It is an important component of many security protocols and applications. Although previously proposed re-mote attestation techniques assisted by specialized secure hardware are effective, they not yet viable for low-cost embedded devices. One no-table alternative is software-based attestation, that is both less costly and more efficient. However, recent results identified weaknesses in some proposed software-based methods, thus showing that security of remote software attestation remains a challenge. Inspired by these developments, this paper explores an approach that relies neither on secure hardware nor on tight timing constraints typi-cal of software-based technqiques. By taking advantage of the bounded memory/storage model of low-cost embedded devices and assuming a small amount of read-only memory (ROM), our approach involves a new primitive â Proofs of Secure Erasure (PoSE-s). We also show that, even though it is effective and provably secure, PoSE-based attestation is not cheap. However, it is particularly well-suited and practical for two other related tasks: secure code update and secure memory/storage erasure. We consider several flavors of PoSE-based protocols and demonstrate their feasibility in the context of existing commodity embedded devices.
Nintedanib for non-IPF progressive pulmonary fibrosis: 12-month outcome data from a real-world multicentre observational study
Background: Nintedanib slows lung function decline for patients with non-IPF progressive pulmonary fibrosis (PPF) in clinical trials, but the real-world safety and efficacy are not known. Methods: In this retrospective cohort study, standardised data was collected across 8 UK centres from patients in whom nintedanib was initiated for PPF between 2019 and 2020 through an early access programme. Rate of lung function change in the 12â
months pre- and post-nintedanib initiation was the primary analysis. Symptoms, drug safety, tolerability, and stratification by interstitial lung disease (ILD) subtype and CT pattern were secondary analyses. Results: 126 patients were included; 67(53%) females, mean age 60(±13) years. At initiation of nintedanib, mean FVC was 1.87â
L (58%) and DLco 32.7% predicted. 68% of patients were prescribed prednisolone (median dose 10â
mg) and 69% prescribed a steroid sparing agent. In the 12â
months after nintedanib initiation, lung function decline was significantly lower than in the preceding 12â
months; FVC â88.8â
ml versus â239.9â
ml respectively, (p=0.004) and absolute decline in DLco â2.1% versus â6.1% respectively; (p=0.004). Response to nintedanib was consistent in sensitivity and secondary analyses. 89/126 (71%) of patients reported side effects but 86 of the surviving 108 patients (80%) were still taking nintedanib at 12â
months with patients reporting a reduced perception of symptom decline. There were no serious adverse events. Conclusion: In PPF, the real-world efficacy of nintedanib replicated that of clinical trials, significantly attenuating lung function decline. Despite the severity of disease, nintedanib was safe and well tolerated in this real-world multicentre stud
Eomesodermin controls a unique differentiation program in human IL-10 and IFN-Îł coproducing regulatory TÂ cells
Whether human IL-10-producing regulatory T cells (âTr1â) represent a distinct differentiation lineage or an unstable activation stage remains a key unsolved issue. Here, we report that Eomesodermin (Eomes) acted as a lineage-defining transcription factor in human IFN-Îł/IL-10 coproducing Tr1-like cells. In vivo occurring Tr1-like cells expressed Eomes, and were clearly distinct from all other CD4 + T-cell subsets, including conventional cytotoxic CD4 + T cells. They expressed Granzyme (Gzm) K, but had lost CD40L and IL-7R expression. Eomes antagonized the Th17 fate, and directly controlled IFN-Îł and GzmK expression. However, Eomes binding to the IL-10 promoter was not detectable in human CD4 + T cells, presumably because critical Tbox binding sites of the mouse were not conserved. A precommitment to a Tr1-like fate, i.e. concominant induction of Eomes, GzmK, and IFN-Îł, was promoted by IL-4 and IL-12-secreting myeloid dendritic cells. Consistently, Th1 effector memory cells contained precommitted Eomes + GzmK + T cells. Stimulation with T-cell receptor (TCR) agonists and IL-27 promoted the generation of Tr1-like effector cells by inducing switching from CD40L to IL-10. Importantly, CD4 + Eomes + T-cell subsets were present in lymphoid and nonlymphoid tissues, and their frequencies varied systemically in patients with inflammatory bowel disease and graft-versus-host disease. We propose that Eomes + Tr1-like cells are effector cells of a unique GzmK-expressing CD4 + T-cell subset
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Naturally drug-loaded chitin: Isolation and applications
Naturally occurring three-dimensional (3D) biopolymer-based matrices that can be used in different biomedical applications are sustainable alternatives to various artificial 3D materials. For this purpose, chitin-based structures from marine sponges are very promising substitutes. Marine sponges from the order Verongiida (class Demospongiae) are typical examples of demosponges with well-developed chitinous skeletons. In particular, species belonging to the family Ianthellidae possess chitinous, flat, fan-like fibrous skeletons with a unique, microporous 3D architecture that makes them particularly interesting for applications. In this work, we focus our attention on the demosponge Ianthella flabelliformis (Linnaeus, 1759) for simultaneous extraction of both naturally occurring (âready-to-useâ) chitin scaffolds, and biologically active bromotyrosines which are recognized as potential antibiotic, antitumor, and marine antifouling substances. We show that selected bromotyrosines are located within pigmental cells which, however, are localized within chitinous skeletal fibers of I. flabelliformis. A two-step reaction provides two products: treatment with methanol extracts the bromotyrosine compounds bastadin 25 and araplysillin-I N20 sulfamate, and a subsequent treatment with acetic acid and sodium hydroxide exposes the 3D chitinous scaffold. This scaffold is a mesh-like structure, which retains its capillary network, and its use as a potential drug delivery biomaterial was examined for the first time. The results demonstrate that sponge-derived chitin scaffolds, impregnated with decamethoxine, effectively inhibit growth of the human pathogen Staphylococcus aureus in an agar diffusion assa
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Glutamatergic correlates of gamma-band oscillatory activity during cognition: a concurrent ER-MRS and EEG study
Frequency specific synchronisation of neuronal firing within the gamma-band (30-70 Hz) appears to be a fundamental correlate of both basic sensory and higher cognitive processing. In-vitro studies suggest that the neurochemical basis of gamma-band oscillatory activity is based on interactions between excitatory (i.e. glutamate) and inhibitory (i.e. GABA) neurotransmitter concentrations. However, the nature of the relationship between excitatory neurotransmitter concentration and changes in gamma band activity in humans remains undetermined. Here, we examine the links between dynamic glutamate concentration and the formation of functional gamma-band oscillatory networks. Using concurrently acquired event-related magnetic resonance spectroscopy and electroencephalography, during a repetition-priming paradigm, we demonstrate an interaction between stimulus type (object vs. abstract pictures) and repetition in evoked gamma-band oscillatory activity, and find that glutamate levels within the lateral occipital cortex, differ in response to these distinct stimulus categories. Importantly, we show that dynamic glutamate levels are related to the amplitude of stimulus evoked gamma-band (but not to beta, alpha or theta or ERP) activity. These results highlight the specific connection between excitatory neurotransmitter concentration and amplitude of oscillatory response, providing a novel insight into the relationship between the neurochemical and neurophysiological processes underlying cognition
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