1,092 research outputs found

    Two classes of nonlocal Evolution Equations related by a shared Traveling Wave Problem

    Full text link
    We consider reaction-diffusion equations and Korteweg-de Vries-Burgers (KdVB) equations, i.e. scalar conservation laws with diffusive-dispersive regularization. We review the existence of traveling wave solutions for these two classes of evolution equations. For classical equations the traveling wave problem (TWP) for a local KdVB equation can be identified with the TWP for a reaction-diffusion equation. In this article we study this relationship for these two classes of evolution equations with nonlocal diffusion/dispersion. This connection is especially useful, if the TW equation is not studied directly, but the existence of a TWS is proven using one of the evolution equations instead. Finally, we present three models from fluid dynamics and discuss the TWP via its link to associated reaction-diffusion equations

    Common mental health disorders in adults with inflammatory skin conditions: nationwide population-based matched cohort studies in the UK

    Get PDF
    BACKGROUND: Psoriasis and atopic eczema are common inflammatory skin diseases. Existing research has identified increased risks of common mental disorders (anxiety, depression) in people with eczema and psoriasis; however, explanations for the associations remain unclear. We aimed to establish the risk factors for mental illness in those with eczema or psoriasis and identify the population groups most at risk. METHODS: We used routinely collected data from the UK Clinical Practice Research Datalink (CPRD) GOLD. Adults registered with a general practice in CPRD (1997-2019) were eligible for inclusion. Individuals with eczema/psoriasis were matched (age, sex, practice) to up to five adults without eczema/psoriasis. We used Cox regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for hazards of anxiety or depression in people with eczema/psoriasis compared to people without. We adjusted for known confounders (deprivation, asthma [eczema], psoriatic arthritis [psoriasis], Charlson comorbidity index, calendar period) and potential mediators (harmful alcohol use, body mass index [BMI], smoking status, and, in eczema only, sleep quality [insomnia diagnoses, specific sleep problem medications] and high-dose oral glucocorticoids). RESULTS: We identified two cohorts with and without eczema (1,032,782, matched to 4,990,125 without), and with and without psoriasis (366,884, matched to 1,834,330 without). Sleep quality was imbalanced in the eczema cohorts, twice as many people with eczema had evidence of poor sleep at baseline than those without eczema, including over 20% of those with severe eczema. After adjusting for potential confounders and mediators, eczema and psoriasis were associated with anxiety (adjusted HR [95% CI]: eczema 1.14 [1.13-1.16], psoriasis 1.17 [1.15-1.19]) and depression (adjusted HR [95% CI]: eczema 1.11 [1.1-1.12], psoriasis 1.21 [1.19-1.22]). However, we found evidence that these increased hazards are unlikely to be constant over time and were especially high 1-year after study entry. CONCLUSIONS: Atopic eczema and psoriasis are associated with increased incidence of anxiety and depression in adults. These associations may be mediated through known modifiable risk factors, especially sleep quality in people with eczema. Our findings highlight potential opportunities for the prevention of anxiety and depression in people with eczema/psoriasis through treatment of modifiable risk factors and enhanced eczema/psoriasis management

    Breakdown of \u3cem\u3eK\u3c/em\u3e Selection in \u3csup\u3e178\u3c/sup\u3eHf

    Get PDF
    Coulomb activation of the four quasiparticle Kπ = 16+ 178Hf isomer (t 1/2 = 31 y) has led to the measurement of a set of Eλ matrix elements coupling the isomer band to the ground band. The present data combined with earlier 178Hf Coulomb excitation data have probed the K components in the wave functions and revealed the onset and saturation of K mixing in low-K bands, whereas the mixing is negligible in the high-K bands. The implications can be applied to other quadrupole-deformed nuclei

    Spin Dependence of \u3cem\u3eK\u3c/em\u3e Mixing, Strong Configuration Mixing, and Electromagnetic Properties of \u3csup\u3e178\u3c/sup\u3eHf

    Get PDF
    The combined data of two Coulomb excitation experiments has verified the purely electromagnetic population of the Kπ = 4+, 6+, 8−, and 16+rotational bands in 178Hf via 2≤ν ≤14 K-forbidden transitions, quantifying the breakdown of the K-selection rule with increasing spin in the low-K bands. The γ -, 4+, and 6+bands were extended, and four new states in a rotational band were tentatively assigned to a previously known Kπ = 0+band. The quasiparticle structure of the 6+(t1/2= 77 ns) and 8−(t1/2= 4 s) isomer bands were evaluated, showing that the gyromagnetic ratios of the 6+ isomer band are consistent with a pure π 7/2+[404], π 5/2+[402] structure. The 8−isomer band at 1147 keV and the second 8−band at 1479 keV, thought to be predominantly ν 7/2-[514], ν 9/2+[624] and π 9/2-[514], π 7/2+[404], respectively, are mixed to a degree approaching the strongmixing limit. Based on measured (Kπ = 16+‖E2‖Kπ = 0+) matrix elements, it was shown that heavy-ion bombardment could depopulate the 16+isomer at the ∼1% level, although no states were found that would mediate photodeexcitation of the isomer via low-energy x-ray absorption

    Product–process matrix and complementarity approach

    Get PDF
    The relationship between different types of innovation is analysed from three different approaches. On the one hand, the distinctive view assumes that the determinants of each type of innovation are different and therefore there is no relationship between them. On the other hand, the integrative view considers that the different types of innovation are complementary. Finally, the product–process matrix framework suggests that the relationship between product innovation and process innovation is substitutive. Using data from Spain belonging to the Technological Innovation Panel (PITEC) for the years 2008, 2009, 2010, 2011 and 2012, we tested which of the three approaches is predominant. To perform the hypothesis test, we used the so-called complementarity approach. We find that there is no unique relation. The nature of the relationship depends on the types of innovation that interact. Our most significant finding is that the relationship between product innovation and process innovation is complementary. This finding contradicts the proposal of the product–process matrix framework. Consequently, the joint implementation of both types of innovation generates a greater impact on the performance of a company than the sum of their separate implementation

    Increased incidence of rare codon clusters at 5' and 3' gene termini:implications for function

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The process of translation can be affected by the use of rare versus common codons within the mRNA transcript.</p> <p>Results</p> <p>Here, we show that rare codons are enriched at the 5' and 3' termini of genes from <it>E. coli </it>and other prokaryotes. Genes predicted to be secreted show significant enrichment in 5' rare codon clusters, but not 3' rare codon clusters. Surprisingly, no correlation between 5' mRNA structure and rare codon usage was observed.</p> <p>Conclusions</p> <p>Potential functional roles for the enrichment of rare codons at terminal positions are explored.</p

    Search for the standard model Higgs boson at LEP

    Get PDF

    Observation of Scaling Violations in Scaled Momentum Distributions at HERA

    Get PDF
    Charged particle production has been measured in deep inelastic scattering (DIS) events over a large range of xx and Q2Q^2 using the ZEUS detector. The evolution of the scaled momentum, xpx_p, with Q2,Q^2, in the range 10 to 1280 GeV2GeV^2, has been investigated in the current fragmentation region of the Breit frame. The results show clear evidence, in a single experiment, for scaling violations in scaled momenta as a function of Q2Q^2.Comment: 21 pages including 4 figures, to be published in Physics Letters B. Two references adde

    Induced pseudoscalar coupling of the proton weak interaction

    Full text link
    The induced pseudoscalar coupling gpg_p is the least well known of the weak coupling constants of the proton's charged--current interaction. Its size is dictated by chiral symmetry arguments, and its measurement represents an important test of quantum chromodynamics at low energies. During the past decade a large body of new data relevant to the coupling gpg_p has been accumulated. This data includes measurements of radiative and non radiative muon capture on targets ranging from hydrogen and few--nucleon systems to complex nuclei. Herein the authors review the theoretical underpinnings of gpg_p, the experimental studies of gpg_p, and the procedures and uncertainties in extracting the coupling from data. Current puzzles are highlighted and future opportunities are discussed.Comment: 58 pages, Latex, Revtex4, prepared for Reviews of Modern Physic
    corecore