5,416 research outputs found

    Small sets of complementary observables

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    Two observables are called complementary if preparing a physical object in an eigenstate of one of them yields a completely random result in a measurement of the other. We investigate small sets of complementary observables that cannot be extended by yet another complementary observable. We construct explicit examples of the unextendible sets up to dimension 1616 and conjecture certain small sets to be unextendible in higher dimensions. Our constructions provide three complementary measurements, only one observable away from the ultimate minimum of two observables in the set. Almost all of our examples in finite dimension allow to discriminate pure states from some mixed states, and shed light on the complex topology of the Bloch space of higher-dimensional quantum systems

    Addressing nutrient shortfalls in 1- to 5-year-old Irish children using diet modeling: development of a protocol for use in country-specific population health

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    BACKGROUND: Dietary habits formed in early childhood can track into later life with important impacts on health. Food-based dietary guidelines (FBDGs) may have a role in improving population health but are lacking for young children. OBJECTIVES: We aimed to establish a protocol for addressing nutrient shortfalls in 1- to 5-y-old children (12–60 mo) using diet modeling in a population-based sample. METHODS: Secondary analysis of 2010–2011 Irish National Pre-School Nutrition Survey data (n = 500) was conducted to identify typical food consumption patterns in 1- to 5-y-olds. Nutrient intakes were assessed against dietary reference values [European Food Safety Authority (EFSA) and Institute of Medicine (IOM)]. To address nutrient shortfalls using diet modeling, 4-d food patterns were developed to assess different milk-feeding scenarios (human milk, whole or low-fat cow milk, and fortified milks) within energy requirement ranges aligned with the WHO growth standards. FBDGs to address nutrient shortfalls were established based on 120 food patterns. RESULTS: Current mean dietary intakes for the majority of 1- to 5-y-olds failed to meet reference values (EFSA) for vitamin D (≀100%), vitamin E (≀88%), DHA (22:6n–3) + EPA (20:5n–3) (IOM; ≀82%), and fiber (≀63%), whereas free sugars intakes exceeded recommendations of <10% energy (E) for 48% of 1- to 3-y-olds and 75% of 4- to 5-y-olds. “Human milk + Cow milk” was the only milk-feeding scenario modeled that predicted sufficient DHA + EPA among 1- to 3-y-olds. Vitamin D shortfalls were not correctable in any milk-feeding scenario, even with supplementation (5 ”g/d), apart from the “Follow-up Formula + Fortified drink” scenario in 1- to 3-y-olds (albeit free sugars intakes were estimated at 12%E compared with ≀5%E as provided by other scenarios). Iron and vitamin E shortfalls were most prevalent in scenarios for 1- to 3-y-olds at ≀25(th) growth percentile. CONCLUSIONS: Using WHO growth standards and international reference values, this study provides a protocol for addressing nutrient shortfalls among 1- to 5-y-olds, which could be applied in country-specific population health

    The Limited Role of Mutually Unbiased Product Bases in Dimension Six

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    We show that a complete set of seven mutually unbiased bases in dimension six, if it exists, cannot contain more than one product basis.Comment: 8 pages, identical to published versio

    Impact of the MTHFR C677T polymorphism on one-carbon metabolites: Evidence from a randomised trial of riboflavin supplementation

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    Homozygosity for the C677T polymorphism in MTHFR (TT genotype) is associated with a 24–87% increased risk of hypertension. Blood pressure (BP) lowering was previously reported in adults with the TT genotype, in response to supplementation with the MTHFR cofactor, riboflavin. Whether the BP phenotype associated with the polymorphism is related to perturbed one-carbon metabolism is unknown. This study investigated one-carbon metabolites and their responsiveness to riboflavin in adults with the TT genotype. Plasma samples from adults (n 115) screened for the MTHFR genotype, who previously participated in RCTs to lower BP, were analysed for methionine, S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH), betaine, choline and cystathionine by liquid chromatography tandem mass spectrometry (LC-MS/MS). The one-carbon metabolite response to riboflavin (1.6 mg/d; n 24) or placebo (n 23) for 16 weeks in adults with the TT genotype was also investigated. Plasma SAM (74.7 ± 21.0 vs 85.2 ± 22.6 nmol/L, P = 0.013) and SAM:SAH ratio (1.66 ± 0.55 vs 1.85 ± 0.51, P = 0.043) were lower and plasma homocysteine was higher (P = 0.043) in TT, compared to CC individuals. In response to riboflavin, SAM (P = 0.008) and cystathionine (P = 0.045) concentrations increased, with no responses in other one-carbon metabolites observed. These findings confirm perturbed one-carbon metabolism in individuals with the MTHFR 677TT genotype, and for the first time demonstrate that SAM, and cystathionine, increase in response to riboflavin supplementation in this genotype group. The genotype-specific, one-carbon metabolite responses to riboflavin intervention observed could offer some insight into the role of this gene-nutrient interaction in blood pressure

    Performance of the LHCb vertex locator

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    The Vertex Locator (VELO) is a silicon microstrip detector that surrounds the proton-proton interaction region in the LHCb experiment. The performance of the detector during the first years of its physics operation is reviewed. The system is operated in vacuum, uses a bi-phase CO2 cooling system, and the sensors are moved to 7 mm from the LHC beam for physics data taking. The performance and stability of these characteristic features of the detector are described, and details of the material budget are given. The calibration of the timing and the data processing algorithms that are implemented in FPGAs are described. The system performance is fully characterised. The sensors have a signal to noise ratio of approximately 20 and a best hit resolution of 4 ÎŒm is achieved at the optimal track angle. The typical detector occupancy for minimum bias events in standard operating conditions in 2011 is around 0.5%, and the detector has less than 1% of faulty strips. The proximity of the detector to the beam means that the inner regions of the n+-on-n sensors have undergone space-charge sign inversion due to radiation damage. The VELO performance parameters that drive the experiment's physics sensitivity are also given. The track finding efficiency of the VELO is typically above 98% and the modules have been aligned to a precision of 1 ÎŒm for translations in the plane transverse to the beam. A primary vertex resolution of 13 ÎŒm in the transverse plane and 71 ÎŒm along the beam axis is achieved for vertices with 25 tracks. An impact parameter resolution of less than 35 ÎŒm is achieved for particles with transverse momentum greater than 1 GeV/c

    A Precise Determination of Electroweak Parameters in Neutrino-Nucleon Scattering

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    The NuTeV collaboration has extracted sin^2theta_W from the ratios of neutral current to charged current neutrino and anti-neutrino cross-sections. Our value, sin^2theta_W(on-shell)=0.2277+/-0.0013(stat)+/-0.0009(syst), is three standard deviations above the standard model prediction. We also present a model independent analysis of the same data.Comment: ReVTeX, 5 pp, 1fig; v2. revised SM prediction; v3. more sig. digits in Eqns 6-7, fix error in Eqn

    Precision luminosity measurements at LHCb

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    Measuring cross-sections at the LHC requires the luminosity to be determined accurately at each centre-of-mass energy √s. In this paper results are reported from the luminosity calibrations carried out at the LHC interaction point 8 with the LHCb detector for √s = 2.76, 7 and 8 TeV (proton-proton collisions) and for √sNN = 5 TeV (proton-lead collisions). Both the "van der Meer scan" and "beam-gas imaging" luminosity calibration methods were employed. It is observed that the beam density profile cannot always be described by a function that is factorizable in the two transverse coordinates. The introduction of a two-dimensional description of the beams improves significantly the consistency of the results. For proton-proton interactions at √s = 8 TeV a relative precision of the luminosity calibration of 1.47% is obtained using van der Meer scans and 1.43% using beam-gas imaging, resulting in a combined precision of 1.12%. Applying the calibration to the full data set determines the luminosity with a precision of 1.16%. This represents the most precise luminosity measurement achieved so far at a bunched-beam hadron collider

    Teaching young consumers in Europe: a multicentre qualitative needs assessment with educators on food hygiene and food safety

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    Aim: Foodborne illnesses have a significant global burden and can be life-threatening, with higher risk in vulnerable groups such as children. SafeConsume is an EU-funded, transdisciplinary project aiming to improve consumers’ food safety behaviour. Developing educational resources on food safety for use in schools has potential to improve teaching of our young consumers. The aim of this study was to explore school educators’ attitudes, behaviours and knowledge towards food hygiene, safety and education. Methods: Focus groups and interviews in England, France, Portugal and Hungary explored educator knowledge, skills, intentions and beliefs around educating young people (11–18 years) about food safety. Data were analysed using NVivo and emerging themes were applied to the Theoretical Domains Framework. Results: A total of 48 educators participated. Knowledge, confidence and skills to teach food safety to young people varied depending on background and training. Educators reported they had a role to teach food safety to young people, were positive about delivering education and optimistic they could improve students’ food safety behaviour. Barriers to teaching included lack of national curriculum coverage, limited time and money, and lack of facilities. Educators reported that social influences (family, celebrity chefs, public health campaigns and social media) were important opportunities to improve young peoples’ awareness of food safety and consequences of foodborne illness. Conclusion: Educator food safety expertise varied; training could help to optimise educator knowledge, confidence and skills. Ministries of Health and Education need encouragement to get food safety incorporated further into school curricula across Europe, so schools will be motivated to prioritise these topics.info:eu-repo/semantics/publishedVersio
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