1,575 research outputs found

    Prevalence of drooling, swallowing, and feeding problems in cerebral palsy across the lifespan: a systematic review and meta‐analyses

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    Aim: To determine the prevalence of drooling, swallowing, and feeding problems in persons with cerebral palsy (CP) across the lifespan. Method: A systematic review was conducted using five different databases (AMED, CINAHL, Embase, MEDLINE, and PubMed). The selection process was completed by two independent researchers and the methodological quality of included studies was assessed using the STROBE and AXIS guidelines. Meta-analyses were conducted to determine pooled prevalence estimates of drooling, swallowing, and feeding problems with stratified group analyses by type of assessment and Gross Motor Function Classification System level. Results: A total of 42 studies were included. Substantial variations in selected outcome measures and variables were observed, and data on adults were limited. Pooled prevalence estimates determined by meta-analyses were as high as 44.0% (95% confidence interval [CI] 35.6–52.7) for drooling, 50.4% (95% CI 36.0–64.8) for swallowing problems, and 53.5% (95% CI 40.7–65.9) for feeding problems. Group analyses for type of assessments were non-significant; however, more severely impaired functioning in CP was associated with concomitant problems of increased drooling, swallowing, and feeding. Interpretation: Drooling, swallowing, and feeding problems are very common in people with CP. Consequently, they experience increased risks of malnutrition and dehydration, aspiration pneumonia, and poor quality of life. What this paper adds: Drooling, swallowing, and feeding problems are very common in persons with cerebral palsy (CP). The prevalence of drooling, swallowing, and feeding problems is 44.0%, 50.4%, and 53.5% respectively. There are limited data on the prevalence of drooling, swallowing, and feeding problems in adults. Higher Gross Motor Function Classification System levels are associated with higher prevalence of drooling, swallowing, and feeding problems. There is increased risk for malnutrition, dehydration, aspiration pneumonia, and poor quality of life in CP

    Multi instanton tests of holography

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    Gauge theories living on stacks of D7-branes are holographically related to IIB gravitational backgrounds with a varying axion-dilaton field (F-theory). The axion-dilaton field is generated by D7, O7 and D-instanton sources and can be written in terms of the chiral correlators of the eight dimensional gauge theory living on the D7-branes. Using localization techniques, we prove that the same correlators determine the gauge coupling of the four-dimensional N=2 supersymmetric SU(2) gauge theories living on the elementary D3-brane which probes the F-theory geometries.Comment: 18 page

    Refined topological amplitudes in N=1 flux compactification

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    We study the implication of refined topological string amplitudes in the supersymmetric N=1 flux compactification. They generate higher derivative couplings among the vector multiplets and graviphoton with generically non-holomorphic moduli dependence. For a particular term, we can compute them by assuming the geometric engineering. We claim that the Dijkgraaf-Vafa large N matrix model with the beta-ensemble measure directly computes the higher derivative corrections to the supersymmetric effective action of the supersymmetric N=1$ gauge theory.Comment: 16 pages, v2: reference adde

    Autophagic Flux is Regulated by Interaction Between the C-terminal Domain of Patched1 and ATG101

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    The Hedgehog (Hh) receptor Patched1 (PTCH1) is a well-known tumor suppressor that in its active form represses Smoothened (SMO) activity, inhibits proliferation, and induces apoptosis. The cytoplasmic C-terminal domain (CTD) regulates PTCH1 turnover and nucleates a pro-apoptotic complex. In this study, it was mechanistically determined that Autophagy Related 10 (ATG101), essential for mammalian autophagy, physically interacts with the CTD of PTCH1 and connects it to the ULK complex, which stimulates the autophagy machinery in response to changes in nutrient availability. This interaction results in a blockade of basal autophagic flux and accumulation of autophagosomes with undegraded cargo. Remarkably, this function of PTCH1 is independent of its repressive activity on SMO, as shown in SMO-deficient cells or in the presence of a SMO inhibitor, but is opposed by Sonic Hedgehog (SHH). These findings reveal a novel non-canonical function of PTCH1 that limits autophagy, mediated by ATG101, which could have therapeutic implications in Hh-dependent cancers. Implications: Loss-of-function of the tumor suppressor Patched1 might promote cancer cell fitness by increasing autophagic flux in response to metabolic or environmental stresses

    Chirped pulse Raman amplification in warm plasma: towards controlling saturation

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    Stimulated Raman backscattering in plasma is potentially an efficient method of amplifying laser pulses to reach exawatt powers because plasma is fully broken down and withstands extremely high electric fields. Plasma also has unique nonlinear optical properties that allow simultaneous compression of optical pulses to ultra-short durations. However, current measured efficiencies are limited to several percent. Here we investigate Raman amplification of short duration seed pulses with different chirp rates using a chirped pump pulse in a preformed plasma waveguide. We identify electron trapping and wavebreaking as the main saturation mechanisms, which lead to spectral broadening and gain saturation when the seed reaches several millijoules for durations of 10's - 100's fs for 250 ps, 800 nm chirped pump pulses. We show that this prevents access to the nonlinear regime and limits the efficiency, and interpret the experimental results using slowly-varying-amplitude, current-averaged particle-in-cell simulations. We also propose methods for achieving higher efficiencies.close0

    Integral Membrane Protein 2A Is a Negative Regulator of Canonical and Non-Canonical Hedgehog Signalling

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    The Hedgehog (Hh) receptor PTCH1 and the integral membrane protein 2A (ITM2A) inhibit autophagy by reducing autolysosome formation. In this study, we demonstrate that ITM2A physically interacts with PTCH1; however, the two proteins inhibit autophagic flux independently, since silencing of ITM2A did not prevent the accumulation of LC3BII and p62 in PTCH1-overexpressing cells, suggesting that they provide alternative modes to limit autophagy. Knockdown of ITM2A potentiated PTCH1-induced autophagic flux blockade and increased PTCH1 expression, while ITM2A overexpression reduced PTCH1 protein levels, indicating that it is a negative regulator of PTCH1 non-canonical signalling. Our study also revealed that endogenous ITM2A is necessary for timely induction of myogenic differentiation markers in C2C12 cells since partial knockdown delays the timing of differentiation. We also found that basal autophagic flux decreases during myogenic differentiation at the same time that ITM2A expression increases. Given that canonical Hh signalling prevents myogenic differentiation, we investigated the effect of ITM2A on canonical Hh signalling using GLI-luciferase assays. Our findings demonstrate that ITM2A is a strong negative regulator of GLI transcriptional activity and of GLI1 stability. In summary, ITM2A negatively regulates canonical and non-canonical Hh signalling

    Refined Cigar and Omega-deformed Conifold

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    Antoniadis et al proposed a relation between the Omega-deformation and refined correlation functions of the topological string theory. We investigate the proposal for the deformed conifold geometry from a non-compact Gepner model approach. The topological string theory on the deformed conifold has a dual description in terms of the c=1 non-critical string theory at the self-dual radius, and the Omega-deformation yields the radius deformation. We show that the refined correlation functions computed from the twisted SL(2,R)/U(1) Kazama-Suzuki coset model at level k=1 have direct c=1 non-critical string theory interpretations. After subtracting the leading singularity to procure the 1PI effective action, we obtain the agreement with the proposal.Comment: 15 pages, v2: reference added, v3: published versio

    Assessment of the potential in vivo ecotoxicity of Double-Walled Carbon Nanotubes (DWNTs) in water, using the amphibian Ambystoma mexicanum

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    Because of their specific properties (mechanical, electrical, etc), carbon nanotubes (CNTs) are being assessed for inclusion in many manufactured products. Due to their massive production and number of potential applications, the impact of CNTs on the environment must be taken into consideration. The present investigation evaluates the ecotoxic potential of CNTs in the amphibian larvae (Ambystoma mexicanum). Acute toxicity and genotoxicity were analysed after 12 days of exposure in laboratory conditions. The genotoxic effects were analysed by scoring the micronucleated erythrocytes in the circulating blood of the larvae according to the French standard micronucleus assay. The results obtained in the present study demonstrated that CNTs are neither acutely toxic nor genotoxic to larvae whatever the CNTs concentration in the water, although black masses of CNTs were observed inside the gut. In the increasing economical context of CNTs, complementary studies must be undertaken, especially including mechanistic and environmental investigations

    Non-perturbative gauge/gravity correspondence in N=2 theories

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    We derive the exact supergravity profile for the twisted scalar field emitted by a system of fractional D3 branes at a Z2 orbifold singularity supporting N=2 quiver gauge theories with unitary groups and bifundamental matter. At the perturbative level this twisted field is "dual" to the gauge coupling but it is corrected non-perturbatively by an infinite tower of fractional D-instantons. The explicit microscopic description allows to derive the gravity profile from disk amplitudes computing the emission rate of the twisted scalar field in terms of chiral correlators in the dual gauge theory. We compute these quantum correlators using multi-instanton localization techniques and/or Seiberg-Witten analysis. Finally, we discuss a non-perturbative relation between the twisted scalar and the effective coupling of the gauge theory for some simple choices of the brane set ups.Comment: 42 pages. 3 figures, PDFLaTe

    Spectral determination of the colour and vertical structure of dark spots in Neptune’s atmosphere

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    Previous observations of dark vortices in Neptune’s atmosphere, such as Voyager 2’s Great Dark Spot (1989), have been made in only a few broad-wavelength channels, hampering efforts to determine these vortices’ pressure levels and darkening processes. We analyse spectroscopic observations of a dark spot on Neptune identified by the Hubble Space Telescope as NDS-2018; the spectral observations were made in 2019 by the Multi Unit Spectroscopic Explorer (MUSE) of the Very Large Telescope (Chile). The MUSE medium-resolution 475–933 nm reflection spectra allow us to show that dark spots are caused by darkening at short wavelengths (700 nm). This bright feature is much deeper than previously studied dark-spot companion clouds and may be connected with the circulation that generates and sustains such spots
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