2,651 research outputs found

    Order of acquisition in learning perceptual categories: a laboratory analogue of the age-of-acquisition effect?

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    In the age-of-acquisition (AoA) effect, an advantage for recognition and production is found for items learned early in life, as compared with items learned later. In this laboratory analogue, participants learned to categorize novel random checkerboard stimuli. Some stimuli were presented from the onset of training; others were introduced later. At test, when early and late stimuli had equal cumulative frequency, early stimuli were classified significantly more quickly. Because stimuli were randomly assigned to be introduced either early or late, we can conclude that early stimuli were categorized more quickly because of their order of acquisition. This finding suggests that age- or order-of-acquisition effects are a general property of any learning system

    Cost effectiveness analysis of different approaches of screening for familial hypercholesterolaemia

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    Objectives To assess the cost effectiveness of strategies to screen for and treat familial hypercholesterolaemia. Design Cost effectiveness analysis. A care pathway for each patient was delineated and the associated probabilities, benefits, and costs were calculated. Participants Simulated population aged 16­54 years in England and Wales. Interventions Identification and treatment of patients with familial hypercholesterolaemia by universal screening, opportunistic screening in primary care, screening of people admitted to hospital with premature myocardial infarction, or tracing family members of affected patients. Main outcome measure Cost effectiveness calculated as cost per life year gained (extension of life expectancy resulting from intervention) including estimated costs of screening and treatment. Results Tracing of family members was the most cost effective strategy (£3097 (&5066, $4479) per life year gained) as 2.6 individuals need to be screened to identify one case at a cost of £133 per case detected. If the genetic mutation was known within the family then the cost per life year gained (£4914) was only slightly increased by genetic confirmation of the diagnosis. Universal population screening was least cost effective (£13 029 per life year gained) as 1365 individuals need to be screened at a cost of £9754 per case detected. For each strategy it was more cost effective to screen younger people and women. Targeted strategies were more expensive per person screened, but the cost per case detected was lower. Population screening of 16 year olds only was as cost effective as family tracing (£2777 with a clinical confirmation). Conclusions Screening family members of people with familial hypercholesterolaemia is the most cost effective option for detecting cases across the whole population

    Entanglement of indistinguishable particles in condensed matter physics

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    The concept of entanglement in systems where the particles are indistinguishable has been the subject of much recent interest and controversy. In this paper we study the notion of entanglement of particles introduced by Wiseman and Vaccaro [Phys. Rev. Lett. 91, 097902 (2003)] in several specific physical systems, including some that occur in condensed matter physics. The entanglement of particles is relevant when the identical particles are itinerant and so not distinguished by their position as in spin models. We show that entanglement of particles can behave differently to other approaches that have been used previously, such as entanglement of modes (occupation-number entanglement) and the entanglement in the two-spin reduced density matrix. We argue that the entanglement of particles is what could actually be measured in most experimental scenarios and thus its physical significance is clear. This suggests entanglement of particles may be useful in connecting theoretical and experimental studies of entanglement in condensed matter systems.Comment: 13 pages, 6 figures, comments welcome, published version (minor changes, added references

    Rapid assembly of highly-functionalised difluorinated cyclooctenones via ring-closing metathesis

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    Building block methodology from trifluoroethanol and ringclosing metathesis using a Fürstner modification of Grubbs’ conditions allows the rapid synthesis of novel difluorinated cyclooctenones

    Evaluating the e-Cigarette Epidemic in US Emergency Departments

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    Background: Electronic cigarettes (e-cigarettes) are often thought to be a healthier option to cigarette smoking. e-Cigarettes have been found to overheat and explode. e-Cigarette explosions have caused severe trauma and rendered patients in critical conditions. Inadvertent exposures to liquid nicotine products have caused systemic poisoning injuries. We sought to characterize e-cigarette injuries presenting to emergency departments (ED) in 2018.Methods: We analyzed one year of data from the US Consumer Product Safety Commission’s National Electronic Injury Surveillance System (NEISS). Patients presenting with injuries associated with e-cigarette products were manually identified for inclusion. We performed descriptive analyses on demographic factors, affected bodily regions, dispositions, locations of occurrence, and mechanisms of injury. By applying sample weights, nationally representative estimates were calculated.Results: A total of 361 667 injury cases were reported in NEISS (2018). We identified 50 e-cigarette injury cases, generating a national estimate of 1739 (95% CI [1333-2148]) patients presenting to US EDs with e-cigarette injuries in 2018. Approximately 1000 pediatric patients (age ≤17 years) and 700 adult patients (age ≥18 years) were included. The median age when presenting to the ED was 4 years (interquartile range [IQR], 1-25). Over 85% of injuries occurred at home. Ingestion (55.0%) was the most common mechanism of injury, followed by explosion (35.8%).Conclusion: Children and adults are susceptible to injury from e-cigarette products. Changes in manufacturing standards may prevent injuries from these products

    Spin coherent quantum transport of electrons between defects in diamond

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    The nitrogen-vacancy color center in diamond has rapidly emerged as an important solid-state system for quantum information processing. While individual spin registers have been used to implement small-scale diamond quantum computing, the realization of a large-scale device requires development of an on-chip quantum bus for transporting information between distant qubits. Here we propose a method for coherent quantum transport of an electron and its spin state between distant NV centers. Transport is achieved by the implementation of spatial stimulated adiabatic Raman passage through the optical control of the NV center charge states and the confined conduction states of a diamond nanostructure. Our models show that for two NV centers in a diamond nanowire, high fidelity transport can be achieved over distances of order hundreds of nanometres in timescales of order hundreds of nanoseconds. Spatial adiabatic passage is therefore a promising option for realizing an on-chip spin quantum bus

    Single maintenance and reliever therapy (SMART) of asthma: a critical appraisal

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    The use of a combination inhaler containing budesonide and formoterol as both maintenance and quick relief therapy (SMART) has been recommended as an improved method of using inhaled corticosteroid/long-acting β agonist (ICS/LABA) therapy. Published double-blind trials show that budesonide/formoterol therapy delivered in SMART fashion achieves better asthma outcomes than budesonide monotherapy or lower doses of budesonide/formoterol therapy delivered in constant dosage. Attempts to compare budesonide/formoterol SMART therapy with regular combination ICS/LABA dosing using other compounds have been confounded by a lack of blinding and unspecified dose adjustment strategies. The asthma control outcomes in SMART-treated patients are poor; it has been reported that only 17.1% of SMART-treated patients are controlled. In seven trials of 6–12 months duration, patients using SMART have used quick reliever daily (weighted average 0.92 inhalations/day), have awakened with asthma symptoms once every 7–10 days (weighted average 11.5% of nights), have suffered asthma symptoms more than half of days (weighted average 54.0% of days) and have had a severe exacerbation rate of one in five patients per year (weighted average 0.22 severe exacerbations/patient/year). These poor outcomes may reflect the recruitment of a skewed patient population. Although improvement from baseline has been attributed to these patients receiving additional ICS therapy at pivotal times, electronic monitoring has not been used to test this hypothesis nor the equally plausible hypothesis that patients who are non-compliant with maintenance medication have used budesonide/formoterol as needed for self-treatment of exacerbations. Although the long-term consequences of SMART therapy have not been studied, its use over 1 year has been associated with significant increases in sputum and biopsy eosinophilia. At present, there is no evidence that better asthma treatment outcomes can be obtained by moment-to-moment symptom-driven use of ICS/LABA therapy than conventional physician-monitored and adjusted ICS/LABA therapy

    Alemtuzumab-induced remission of multiple sclerosis-associated uveitis

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    Purpose The purpose of the study was to report a case of multiple sclerosis (MS)-associated uveitis refractory to conventional immunosuppressants, with subsequent remission following treatment with alemtuzumab. Methods Case report Patient was treated with intravenous alemtuzumab, a lymphocyte depleting anti-CD52 monoclonal antibody that has recently been approved for use in relapsing MS. Results A 17-year-old female presented with bilateral optic neuritis and subsequently bilateral intermediate uveitis and secondary macular oedema. She was diagnosed with active relapsing MS for which she received treatment with alemtuzumab. The intraocular inflammation previously refractory to conventional immunosuppressants responded to alemtuzumab, inducing remission. Conclusions To our knowledge, this is the first such report of alemtuzumab treatment in MS-associated ocular inflammatory disease and may demonstrate a potential utility for this drug in related conditions

    Human osteoblasts obtained from distinct periarticular sites demonstrate differences in biological function in vitro.

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    AIMS: Accumulated evidence indicates that local cell origins may ingrain differences in the phenotypic activity of human osteoblasts. We hypothesized that these differences may also exist in osteoblasts harvested from the same bone type at periarticular sites, including those adjacent to the fixation sites for total joint implant components. METHODS: Human osteoblasts were obtained from the acetabulum and femoral neck of seven patients undergoing total hip arthroplasty (THA) and from the femoral and tibial cuts of six patients undergoing total knee arthroplasty (TKA). Osteoblasts were extracted from the usually discarded bone via enzyme digestion, characterized by flow cytometry, and cultured to passage three before measurement of metabolic activity, collagen production, alkaline phosphatase (ALP) expression, and mineralization. RESULTS: Osteoblasts from the acetabulum showed lower proliferation (p = 0.034), cumulative collagen release (p < 0.001), and ALP expression (p = 0.009), and produced less mineral (p = 0.006) than those from the femoral neck. Osteoblasts from the tibia produced significantly less collagen (p = 0.021) and showed lower ALP expression than those from the distal femur. CONCLUSION: We have demonstrated for the first time an anatomical regional variation in the biological behaviours of osteoblasts on either side of the hip and knee joint. The lower osteoblast proliferation, matrix production, and mineralization from the acetabulum compared to those from the proximal femur may be reflected in differences in bone formation and implant fixation at these sites. Cite this article: Bone Joint Res 2021;10(9):611-618
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