3,404 research outputs found
Cognitive cost of switching between standard and dialect varieties
Switching between languages in picture naming incurs a cost associated with inhibition of the non-target language (Meuter & Allport, 1999).This cost is symmetrical in balanced bilinguals and asymmetrical in unbalanced bilinguals with higher cost associated with switching back into L1 (Costa & Santesteban,2004).We investigated whether cost is incurred in similar ways by bidialectals switching between two dialects.To increase generalisablity, we conducted this experiment in 2 locations: in Scotland using Standard Scottish English and Dundonian-Scots bidialectals) and in Germany using German and Öcher bidialectals).We also investigated differences between active vs. passive, and older vs. younger bidialectals
Can monolinguals be like bilinguals? Evidence from dialect switching
Bilinguals rely on cognitive control mechanisms like selective activation and inhibition of lexical entries to prevent intrusions from the non-target language. We present cross-linguistic evidence that these mechanisms also operate in bidialectals. Thirty-two native German speakers who sometimes use the Öcher Platt dialect, and thirty-two native English speakers who sometimes use the Dundonian Scots dialect completed a dialect-switching task. Naming latencies were higher for switch than for non-switch trials, and lower for cognate compared to non-cognate nouns. Switch costs were symmetrical, regardless of whether participants actively used the dialect or not. In contrast, sixteen monodialectal English speakers, who performed the dialectswitching task after being trained on the Dundonian words, showed asymmetrical switch costs with longer latencies when switching back into Standard English. These results are reminiscent of findings for balanced vs. unbalanced bilinguals, and suggest that monolingual dialect speakers can recruit control mechanisms in similar ways as bilinguals
Participation in continuing vocational education and training: results from the case studies and qualitative investigations
Contents: Introduction; Germany; Greece; Italy; Portugal; Spain; United Kingdo
Using a two-step framework for the investigation of storm impacted beach/dune erosion
Long-term coastal management of beach/dune systems requires the definition and assessment of storm events. This study presents a framework using statistical analyses and numerical modelling (XBeach) to characterize storm events and investigate their impact on beach/dune erosion. The method is developed using exemplary data from Formby Point on the Sefton coast (UK), which has a complex beach morphology and frontal dunes. Relevant storm events are classified by a versatile univariate response function taking into account both nearshore water levels and offshore significant wave heights (Hs). It is shown that compared to the established storm classification (Hs ≥ 2.5 m) 35% more storm events that are relevant for beach/dune erosion are identified. Also the events exceed critical conditions for longer durations, and cause greater erosion impact (12%) along the beach/dune profile. The proposed classification of storm events thus captures relevant events for the storm erosion and can inform coastal management strategies. This framework is widely applicable to other beach/dune systems. © 2021 The Author
Hot Subdwarfs in Binaries as the Source of the Far-UV Excess in Elliptical Galaxies
The excess of far-ultraviolet (far-UV) radiation in elliptical galaxies has
remained one of their most enduring puzzles. In contrast, the origin of old
blue stars in the Milky Way, hot subdwarfs, is now reasonably well understood:
they are hot stars that have lost their hydrogen envelopes by various binary
interactions. Here, we review the main evolutionary channels that produce hot
subdwarfs in the Galaxy and present the results of binary population synthesis
simulations that reproduce the main properties of the Galactic hot-subdwarf
population. Applying the same model to elliptical galaxies, we show how this
model can explain the main observational properties of the far-UV excess,
including the far-UV spectrum, without the need to invoke ad hoc physical
processes. The model implies that the UV excess is not a sign of age, as has
been postulated previously, and predicts that it should not be strongly
dependent on the metallicity of the population.Comment: 11 pages, 6 figures (preprint version
Designer lipid-like peptides
A crucial bottleneck in membrane protein studies, particularly G-protein coupled receptors, is the notorious difficulty of finding an optimal detergent that can solubilize them and maintain their stability and function. Here we report rapid production of 12 unique mammalian olfactory receptors using short designer lipid-like peptides as detergents. The peptides were able to solubilize and stabilize each receptor. Circular dichroism showed that the purified olfactory receptors had alpha-helical secondary structures. Microscale thermophoresis suggested that the receptors were functional and bound their odorants. Blot intensity measurements indicated that milligram quantities of each olfactory receptor could be produced with at least one peptide detergent. The peptide detergents' capability was comparable to that of the detergent Brij-35. The ability of 10 peptide detergents to functionally solubilize 12 olfactory receptors demonstrates their usefulness as a new class of detergents for olfactory receptors, and possibly other G-protein coupled receptors and membrane proteins
A robust, semi-automated approach for counting cementum increments imaged with synchrotron X-ray computed tomography
Cementum, the tissue attaching mammal tooth roots to the periodontal ligament, grows appositionally throughout life, displaying a series of circum-annual incremental features. These have been studied for decades as a direct record of chronological lifespan. The majority of previous studies on cementum have used traditional thin-section histological methods to image and analyse increments. However, several caveats have been raised in terms of studying cementum increments in thin-sections. Firstly, the limited number of thin-sections and the two-dimensional perspective they impart provide an incomplete interpretation of cementum structure, and studies often struggle or fail to overcome complications in increment patterns that complicate or inhibit increment counting. Increments have been repeatedly shown to both split and coalesce, creating accessory increments that can bias increment counts. Secondly, identification and counting of cementum increments using human vision is subjective, and it has led to inaccurate readings in several experiments studying individuals of known age. Here, we have attempted to optimise a recently introduced imaging modality for cementum imaging; X-ray propagation-based phase-contrast imaging (PPCI). X-ray PPCI was performed for a sample of rhesus macaque (Macaca mulatta) lower first molars (n = 10) from a laboratory population of known age. PPCI allowed the qualitative identification of primary/annual versus intermittent secondary increments formed by splitting/coalescence. A new method for semi-automatic increment counting was then integrated into a purpose-built software package for studying cementum increments, to count increments in regions with minimal complications. Qualitative comparison with data from conventional cementochronology, based on histological examination of tissue thin-sections, confirmed that X-ray PPCI reliably and non-destructively records cementum increments (given the appropriate preparation of specimens prior to X-ray imaging). Validation of the increment counting algorithm suggests that it is robust and provides accurate estimates of increment counts. In summary, we show that our new increment counting method has the potential to overcome caveats of conventional cementochronology approaches, when used to analyse three-dimensional images provided by X-ray PPCI.Peer reviewe
Mixed Valvular Disease Following Transcatheter Aortic Valve Replacement: Quantification and Systematic Differentiation Using Clinical Measurements and Image-Based Patient‐Specific In Silico Modeling
Background: Mixed valvular disease (MVD), mitral regurgitation (MR) from pre‐existing disease in conjunction with paravalvular leak (PVL) following transcatheter aortic valve replacement (TAVR), is one of the most important stimuli for left ventricle (LV) dysfunction, associated with cardiac mortality. Despite the prevalence of MVD, the quantitative understanding of the interplay between pre‐existing MVD, PVL, LV, and post‐TAVR recovery is meager.
Methods and Results: We quantified the effects of MVD on valvular‐ventricular hemodynamics using an image‐based patient‐specific computational framework in 72 MVD patients. Doppler pressure was reduced by TAVR (mean, 77%; N=72; P<0.05), but it was not always accompanied by improvements in LV workload. TAVR had no effect on LV workload in 22 patients, and LV workload post‐TAVR significantly rose in 32 other patients. TAVR reduced LV workload in only 18 patients (25%). PVL significantly alters LV flow and increases shear stress on transcatheter aortic valve leaflets. It interacts with mitral inflow and elevates shear stresses on mitral valve and is one of the main contributors in worsening of MR post‐TAVR. MR worsened in 32 patients post‐TAVR and did not improve in 18 other patients.
Conclusions: PVL limits the benefit of TAVR by increasing LV load and worsening of MR and heart failure. Post‐TAVR, most MVD patients (75% of N=72; P<0.05) showed no improvements or even worsening of LV workload, whereas the majority of patients with PVL, but without that pre‐existing MR condition (60% of N=48; P<0.05), showed improvements in LV workload. MR and its exacerbation by PVL may hinder the success of TAVR
HP1γ function is required for male germ cell survival and spermatogenesis
<p>Abstract</p> <p>Background</p> <p>HP1 proteins are conserved components of eukaryotic constitutive heterochromatin. In mammals, there are three genes that encode HP1-like proteins, termed HP1α, HP1β and HP1γ, which have a high degree of homology This paper describes for the first time, to our knowledge, the physiological function of HP1γ using a gene-targeted mouse.</p> <p>Results</p> <p>While targeting the <it>Cbx3 </it>gene (encoding the HP1γ protein) with a conditional targeting vector, we generated a hypomorphic allele (<it>Cbx3</it><sup><it>hypo</it></sup>), which resulted in much reduced (barely detectable) levels of HP1γ protein. Homozygotes for the hypomorphic allele (<it>Cbx3</it><sup><it>hypo</it>/<it>hypo</it></sup>) are rare, with only 1% of <it>Cbx3</it><sup><it>hypo</it>/<it>hypo </it></sup>animals reaching adulthood. Adult males exhibit a severe hypogonadism that is associated with a loss of germ cells, with some seminiferous tubules retaining only the supporting Sertoli cells (Sertoli cell-only phenotype). The percentage of seminiferous tubules that are positive for L1 ORF1 protein (ORF1p) in <it>Cbx3</it><sup><it>hypo</it>/<it>hypo </it></sup>testes is greater than that for wild-type testes, indicating that L1 retrotransposon silencing is reversed, leading to ectopic expression of ORF1p in <it>Cbx3</it><sup><it>hypo</it>/<it>hypo </it></sup>germ cells.</p> <p>Conclusions</p> <p>The <it>Cbx3 </it>gene product (the HP1γ protein) has a non-redundant function during spermatogenesis that cannot be compensated for by the other two HP1 isotypes. The <it>Cbx3</it><sup><it>hypo</it>/<it>hypo </it></sup>spermatogenesis defect is similar to that found in <it>Miwi2 </it>and <it>Dnmt3L </it>mutants. The <it>Cbx3 </it>gene-targeted mice generated in this study provide an appropriate model for the study of HP1γ in transposon silencing and parental imprinting.</p
Reconstructing the Scattering Matrix from Scanning Electron Diffraction Measurements Alone
Three-dimensional phase contrast imaging of multiply-scattering samples in
X-ray and electron microscopy is extremely challenging, due to small numerical
apertures, the unavailability of wavefront shaping optics, and the highly
nonlinear inversion required from intensity-only measurements. In this work, we
present a new algorithm using the scattering matrix formalism to solve the
scattering from a non-crystalline medium from scanning diffraction
measurements, and recover the illumination aberrations. Our method will enable
3D imaging and materials characterization at high resolution for a wide range
of materials
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