203 research outputs found

    Demonstrating an absolute quantum advantage in direct absorption measurement

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    Engineering apparatus that harness quantum theory promises to offer practical advantages over current technology. A fundamentally more powerful prospect is that such quantum technologies could out-perform any future iteration of their classical counterparts, no matter how well the attributes of those classical strategies can be improved. Here, for optical direct absorption measurement, we experimentally demonstrate such an instance of an absolute advantage per photon probe that is exposed to the absorbative sample. We use correlated intensity measurements of spontaneous parametric downconversion using a commercially available air-cooled CCD, a new estimator for data analysis and a high heralding efficiency photon-pair source. We show this enables improvement in the precision of measurement, per photon probe, beyond what is achievable with an ideal coherent state (a perfect laser) detected with 100% efficient and noiseless detection. We see this absolute improvement for up to 50% absorption, with a maximum observed factor of improvement of 1.46. This equates to around 32% reduction in the total number of photons traversing an optical sample, compared to any future direct optical absorption measurement using classical light

    Rift kinematics preserved in deep-time erosional landscape below the northern North Sea

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    Our understanding of continental rifting is, in large parts, derived from the stratigraphic record. This record is, however, incomplete as it does not often capture the geomorphic and erosional signal of rifting. New 3D seismic reflection data reveal a Late Permian-Early Triassic landscape incised into the pre-rift basement of the northern North Sea. This landscape, which covers at least 542 km2, preserves a drainage system bound by two major tectonic faults. A quantitative geomorphic analysis of the drainage system reveals 68 catchments, with channel steepness and knickpoint analysis of catchment-hosted palaeo-rivers showing that the landscape preserved a >2 Myr long period of transient tectonics. We interpret that this landscape records a punctuated uplift of the footwall of a major rift-related normal fault (Vette Fault) at the onset of rifting. The landscape was preserved by a combination of relatively rapid subsidence in the hangingwall of a younger fault (Øygarden Fault) and burial by post-incision sediments. As such, we show how and why erosional landscapes are preserved in the stratigraphic record, and how they can help us understand the tectono-stratigraphic evolution of ancient continental rifts.publishedVersio

    Experiencing loneliness in parenthood: A scoping review

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    Aims: Chronic loneliness is experienced by around a third of parents, but there is no comprehensive review into how, why and which parents experience loneliness. This scoping review aimed to provide insight into what is already known about parental loneliness and give directions for further applied and methodological research. Method: Searches for peer reviewed articles were undertaken in six databases: PsycINFO, Medline, CINAHL, Embase, Web of Science and Scopus, during May 2019 to February 2020. We searched for English studies which examined loneliness experienced during parenthood, including studies that involved parents with children under 16 years and living at home and excluding studies on pregnancy, childbirth or post-birth hospital care. Results: From 2566 studies retrieved, 133 were included for analysis. Most studies (n=80) examined the experience of loneliness in specific groups of parents, e.g. teenage parents, parents of a disabled child. Other studies examined theoretical issues (n=6) or health and well-being impacts on parents (n=16) and their offspring (n=17). There were 14 intervention studies with parents that measured loneliness as an outcome. Insights indicate that parental loneliness may be different to loneliness experienced in other cohorts. There is evidence that parental loneliness has direct and intergenerational impacts on parent and child mental health. Some parents (e.g. with children with chronic illness or disability, immigrant or ethnic minority parents) also appear to be at increased risk of loneliness although evidence is not conclusive. Conclusion: This work has identified key gaps with further international, comparative and conceptual research needed

    The CATFISH study protocol: an evaluation of a water fluoridation scheme

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    Abstract Background Tooth decay is the commonest disease of childhood. We have known for over 90 years that fluoride can prevent tooth decay; it is present in nearly all toothpastes and can be provided in mouthwashes, gels and varnishes. The oldest method of applying fluoride is via the water supply at a concentration of 1 part per million. The two most important reviews of water fluoridation in the United Kingdom (the York Review and MRC Report on water fluoridation and health) concluded that whilst there was evidence to suggest water fluoridation provided a benefit in caries reduction, there was a need to improve the evidence base in several areas. Methods/Design This study will use a natural experiment to assess the incidence of caries in two geographical areas, one in which the water supply is returned to being fluoridated following a discontinuation of fluoridation and one that continues to have a non-fluoridated water supply. The oral health of two discrete study populations will be evaluated - those born 9 months after the water fluoridation was introduced, and those who were in their 1st year of school after the introduction of fluoridated water. Both populations will be followed prospectively for 5 years using a census approach in the exposed group along with matched numbers recruitment in a non-exposed control. Parents of the younger cohort will complete questionnaires every 6 months with child clinical examination at ages 3 and 5, whilst the older cohort will have clinical examinations only, at approximately 5, 7 and 11 years old. Discussion This project provides a unique opportunity to conduct a high quality evaluation of the reintroduction of a water fluoridation scheme, which satisfies the inclusion criteria stipulated by the York systematic review and can address the design issues identified in the MRC report. The research will make a major contribution to the understanding of the costs and effects of water fluoridation in the UK in the 21st Century. Its findings will help inform UK policy on this important public health intervention and may have a significant impact on public health policy in other developed countries. There is currently true equipoise in relation to the effectiveness of water fluoridation in contemporary populations and while the biological plausibility is well established, there is a need to examine impact on the changing epidemiological status of dental decay

    Platelet-activating factor receptor in GtoPdb v.2023.1

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    Platelet-activating factor (PAF, 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) is an ether phospholipid mediator associated with platelet coagulation, but also subserves inflammatory roles. The PAF receptor (provisional nomenclature recommended by NC-IUPHAR [38]) is activated by PAF and other suggested endogenous ligands are oxidized phosphatidylcholine [74] and lysophosphatidylcholine [98]. It may also be activated by bacterial lipopolysaccharide [91]

    Platelet-activating factor receptor (version 2019.4) in the IUPHAR/BPS Guide to Pharmacology Database

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    Platelet-activating factor (PAF, 1-O-alkyl-2-acetyl-sn-glycero-3-phosphocholine) is an ether phospholipid mediator associated with platelet coagulation, but also subserves inflammatory roles. The PAF receptor (provisional nomenclature recommended by NC-IUPHAR [37]) is activated by PAF and other suggested endogenous ligands are oxidized phosphatidylcholine [73] and lysophosphatidylcholine [96]. It may also be activated by bacterial lipopolysaccharide [89]

    Exploring blog narratives of parental loneliness: A thematic network analysis

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    UK-based national surveys and international longitudinal studies have shown that around a third of parents experience chronic or persistent loneliness. There is limited research about the experience of loneliness in parenthood, however blogs authored by parents, sharing their personal experiences about loneliness offer a potential rich data source. The purpose of this study was to identify and analyse blog narratives written by parents who had experienced loneliness to increase understanding of their experiences. One hundred and ninety-six relevant blog posts were identified, of which 157 had contact details to request permission to use the blog post in the study. Twenty-two parent bloggers gave their permission. Thematic network analysis was used to open code the blogs and 4 organising themes and subthemes emerged, which centred on a global theme of disconnection. Disconnection underpinned themes relating to a sense that being a parent was overwhelming, changes in identity linked to becoming a parent, difficulties in sharing feelings of loneliness with others, and a need for social connection. Findings point to parents being unprepared for the transition to parenthood, with implications for perinatal education and support, including further opportunities for parents to connect to reduce social isolation
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