53,190 research outputs found

    Feasibility of collecting oral fluid samples in the home setting to determine seroprevalence of infections in a large-scale cohort of preschool-aged children

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    Oral fluid is a non-invasive biological sample, which can be returned by post, making it suitable for large-scale epidemiological studies in children. We report our experience of oral fluid collection from 14 373 preschool-aged children in the UK Millennium Cohort Study. Samples were collected by mothers in the home setting following the guidance of trained interviewers, and posted to the laboratory. Samples were received from 11698 children (81.4 %). Children whose mothers were of Black Caribbean ethnicity and who lived in non-English-speaking households were less likely to provide a sample, and those with a maternal history of asthma more likely to provide a sample [adjusted risk ratio (95 % CI) 0.85 (0.73-0.98), 0.87 (0.77-0.98) and 1.03 (1.00-1.05) respectively]. Collection of oral fluid samples is feasible and acceptable in large-scale child cohort studies. Formal interpreter support may be required to increase participation rates in surveys that collect biological samples from ethnic minorities

    Haptoglobin genotype, haemoglobin and malaria in Gambian children

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    Quantum linear amplifier enhanced by photon subtraction and addition

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    A deterministic quantum amplifier inevitably adds noise to an amplified signal due to the uncertainty principle in quantum physics. We here investigate how a quantum-noise-limited amplifier can be improved by additionally employing the photon subtraction, the photon addition, and a coherent superposition of the two, thereby making a probabilistic, heralded, quantum amplifier. We show that these operations can enhance the performance in amplifying a coherent state in terms of intensity gain, fidelity, and phase uncertainty. In particular, the photon subtraction turns out to be optimal for the fidelity and the phase concentration among these elementary operations, while the photon addition also provides a significant reduction in the phase uncertainty with the largest gain effect.Comment: published version, 7 pages, 9 figure

    Chemical potential oscillations from a single nodal pocket in the underdoped high-Tc superconductor YBa2Cu3O6+x

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    The mystery of the normal state in the underdoped cuprates has deepened with the use of newer and complementary experimental probes. While photoemission studies have revealed solely `Fermi arcs' centered on nodal points in the Brillouin zone at which holes aggregate upon doping, more recent quantum oscillation experiments have been interpreted in terms of an ambipolar Fermi surface, that includes sections containing electron carriers located at the antinodal region. To address the question of whether an ambipolar Fermi surface truly exists, here we utilize measurements of the second harmonic quantum oscillations, which reveal that the amplitude of these oscillations arises mainly from oscillations in the chemical potential, providing crucial information on the nature of the Fermi surface in underdoped YBa2Cu3O6+x. In particular, the detailed relationship between the second harmonic amplitude and the fundamental amplitude of the quantum oscillations leads us to the conclusion that there exists only a single underlying quasi-two dimensional Fermi surface pocket giving rise to the multiple frequency components observed via the effects of warping, bilayer splitting and magnetic breakdown. A range of studies suggest that the pocket is most likely associated with states near the nodal region of the Brillouin zone of underdoped YBa2Cu3O6+x at high magnetic fields.Comment: 7 pages, 4 figure

    Does Antarctic Krill Employ Body Shrinkage as an Overwintering Strategy?

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    To determine if Antarctic krill employ body shrinkage as one of its overwintering mechanisms in the field, Euphausia superba and Euphausia crystallorophias were collected during fall and winter in and around Marguerite Bay through US Southern Ocean GLOBEC field programs during fall and winter 2001 and 2002. The relationships between the body length and weight of both krill species were exponentially correlated with no significant differences between the two species (p\u3e0.05). The ratio between eye diameter and body length of individual krill was examined in an expectation that it could be used as an indicator of the body shrinkage as previously suggested by Shin and Nicol (2002). These ratios were significantly different between the two krill species. Especially, E. crystallorophias had bigger eyes than E. superba. In both krill species, eye diameters were highly correlated with body lengths (regression coefficients ≥ 0.70). For E. crystallorophias, no significant differences of the ratio of eye diameter/body length were detected between fall and winter. Even though the ratios for E. superba were seasonally varied, it was not clear whether body shrinkage was an actual and critical overwintering mechanism for the krill population found in this study area. These results suggest that some individuals of E. superba might experience the body shrinkage during a part of their life, but this morphological index alone (eye diameter/body length) may be insufficient to unambiguously separate the shrunk krill from the non-shrunk ones in the field-collected animals

    Defining language impairments in a subgroup of children with autism spectrum disorder

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    Autism spectrum disorder (ASD) is diagnosed on the basis of core impairments in pragmatic language skills, which are found across all ages and subtypes. In contrast, there is significant heterogeneity in language phenotypes, ranging from nonverbal to superior linguistic abilities, as defined on standardized tests of vocabulary and grammatical knowledge. The majority of children are verbal but impaired in language, relative to age-matched peers. One hypothesis is that this subgroup has ASD and co-morbid specific language impairment (SLI). An experiment was conducted comparing children with ASD to children with SLI and typically developing controls on aspects of language processing that have been shown to be impaired in children with SLI: repetition of nonsense words. Patterns of performance among the children with ASD and language impairment were similar to those with SLI, and contrasted with the children with ASD and no language impairment and typical controls, providing further evidence for the hypothesis that a subgroup of children with ASD has co-morbid SLI. The findings are discussed in the context of brain imaging studies that have explored the neural bases of language impairment in ASD and SLI, and overlap in the genes associated with elevated risk for these disorders.M01 RR00533 - NCRR NIH HHS; R01 DC10290 - NIDCD NIH HHS; U19 DC03610 - NIDCD NIH HH

    Smoking and quitting behaviour by sexual orientation: a cross-sectional survey of adults in England

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    Objective: To assess associations between sexual orientation and smoking and quitting behaviour among adults in England. Methods: Data were collected from 112,537 adults (≥16y) participating in a nationally-representative monthly cross-sectional survey between 07/2013 and 02/2019. Sexual orientation was self-reported as heterosexual, bisexual, lesbian/gay, or prefer-not-to-say. Main outcomes were smoking status, e-cigarette use, cigarettes per day, time to first cigarette, motivation to stop smoking, motives for quitting, use of cessation support, and past‐year quit attempts. Associations were analysed separately for men and women using multivariable regression models adjusted for relevant covariates. Results: Smoking prevalence is now similar between gay (21.6%), prefer-not-to-say (20.5%) and heterosexual men (20.0%), and lesbian (18.3%) and heterosexual women (16.9%), but remains higher among bisexual men (28.2%, ORadj 1.41, 95%CI 1.11; 1.79) and bisexual women (29.8%, ORadj 1.64, 95%CI 1.33; 2.03) and lower among prefer-not-to-say women (14.5%, ORadj 0.85, 95%CI 0.72; 0.99). Among smokers, bisexuals were less addicted than heterosexuals, with bisexual men smoking fewer cigarettes per day (Badj -2.41, 95%CI -4.06; -0.75) and bisexual women less likely to start smoking within 30 minutes of waking (ORadj 0.66, 95% CI0.45; 0.95) than heterosexuals. However, motivation to stop smoking and quit attempts did not differ significantly. Conclusions: In England, differences in smoking prevalence among people with different sexual orientations have narrowed, primarily driven by a larger decline in smoking rates among sexual minority groups than heterosexuals. Bisexual men and women remain more likely to smoke but have lower levels of addiction while being no less likely to try to quit
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