Long-term trends in BMI: are contemporary childhood BMI growth references appropriate when looking at historical datasets?

Background Body mass index (BMI) is the most widely used surrogate measure of adiposity, and BMI z-scores are often calculated when comparing childhood BMI between populations and population sub-groups. Several growth references are currently used as the basis for calculation of such z-scores, for both contemporary cohorts as well as cohorts born decades ago. Due to the widely acknowledged increases in childhood obesity over recent years it is generally assumed that older birth cohorts would have lower BMIs relative to the current standards. However, this reasonable assumption has not been formally tested.   Methods Two growth references (1990 UK and 2000 CDC) are used to calculate BMI z-scores in three historical British national birth cohorts (National Survey of Health and Development (1958), National Child Development Study (1958) and British Cohort Study (1970)). BMI z-scores are obtained for each child at each follow-up age using the lambda-mu-sigma (LMS) method, and their distributions examined.   Results Across all three cohorts, median BMI z-score at each follow-up age is observed to be positive in early childhood. This is contrary to what might have been expected given the assumed temporal increase in childhood BMI. However, z-scores then decrease and become negative during adolescence, before increasing once more.   Conclusions The differences in BMI distribution between the historical cohorts and the contemporary growth references appear systematic and similar across the cohorts. This might be explained by contemporary reference data describing a faster tempo of weight increase relative to height than observed in older birth cohorts. Comparisons using z-scores over extended periods of time should therefore be interpreted with caution

Data management study, volume 5. Appendix G - Contractor data package reliability assurance /RA/ Final report

Contractor data management package for system, subsystem, and component reliability assurance of Voyager spacecraf

A realistic assessment of the CTA sensitivity to dark matter annihilation

We estimate the sensitivity of the upcoming CTA gamma-ray telescope to DM annihilation at the Galactic centre, improving on previous analyses in a number of significant ways. First, we perform a detailed analyses of all backgrounds, including diffuse astrophysical emission for the first time in a study of this type. Second, we present a statistical framework for including systematic errors and estimate the consequent degradation in sensitivity. These errors may come from e.g. event reconstruction, Monte Carlo determination of the effective area or uncertainty in atmospheric conditions. Third, we show that performing the analysis on a set of suitably optimised regions of interest makes it possible to partially compensate for the degradation in sensitivity caused by systematics and diffuse emission. To probe dark matter with the canonical thermal annihilation cross-section, CTA systematics like non-uniform variations in acceptance over a single field of view must be kept below the 0.3% level, unless the dark matter density rises more steeply in the centre of the Galaxy than predicted by a typical Navarro-Frenk-White or Einasto profile. For a contracted $r^{-1.3}$ profile, and systematics at the 1% level, CTA can probe annihilation to $b\bar{b}$ at the canonical thermal level for dark matter masses between 100 GeV and 10 TeV.Comment: V2: 25 pages, 7 figures, numerical bug fixed, exclusion limits weakened by approximately 30%, main conclusions unchange

Genome Sequence of the Halophilic Bacterium Kangiella spongicola ATCC BAA-2076T

The Gram-negative genus Kangiella contains a number of halophilic species that display high levels of iso-branched fatty acids. Kangiella spongicola was isolated from a marine sponge, Chondrilla nucula, from the Florida Keys in the United States. A genome assembly of 2,825,399 bp with a 44.31% G+C content was generated from strain A79T (=ATCC BAA-2076T)

Methanol oxidation on Fe2O3catalysts and the effects of surface Mo

The adsorption of methanol on haematite has been investigated using temperature programmed methods, combined with in situ DRIFTS. Model catalysts based on this material have then been made with a shell–core configuration of molybdenum oxide monolayers on top of the haematite core. These are used as models of industrial iron molybdate catalysts, used to selectively oxidise methanol to formaldehyde, one of the major chemical outlets for methanol. Haematite itself is completely ineffective in this respect since it oxidises it to CO2 and the DRIFTS shows that this occurs by oxidation of methoxy to formate at around 200 °C. The decomposition behaviour is affected by the absence or presence of oxygen in the gas phase; oxygen destabilises the methoxy and enhances formate production. In contrast, when a monolayer of molybdena is placed onto the surface by incipient wetness, and it remains there after calcination, the pathway to formate production is blocked and formaldehyde is the main gas phase product in TPD after methanol dosing

Punctuated equilibrium or the orthodox cycle? : change and continuity in UK macroeconomic policymaking

This thesis provides a study of United Kingdom (UK) macroeconomic policy and economic ideas. Specifically, the thesis seeks to explore the reasons when and why UK macroeconomic policy and economic ideas exhibits change or continuity. The central contention of this thesis is that the model of punctuated equilibrium provides a flawed understanding and explanation of when and why policies and idea exhibit continuity and change in UK macroeconomic policymaking. In particular, the thesis seeks to fill two gaps in our existing knowledge of UK economic policymaking, which emerge from critical literature reviews. The first gap pertains to the need for greater specificity in our understanding and definition of orthodox UK macroeconomic policy. The second gap relates to the need for a superior understanding of when and why UK macroeconomic policy and economic ideas exhibits change and continuity.The original contribution of this thesis to the literature on UK economic policymaking arises from the two research findings generated in Chapters Three and Four, which are then tested in a series of case-study chapters in the second half of the thesis. The first research finding is the provision of greater precision in our understanding and definition of orthodox macroeconomic policy. The second research finding is the identification of a historical pattern in UK macroeconomic policymaking, which is named the orthodox cycle. The orthodox cycle utilises the new understanding and definition of orthodox macroeconomic policy to show the continuity of orthodox policy and ideas in UK macroeconomic policymaking, through a series of distinct phases, in the aftermath of crises and changes in government

The application of inelastic neutron scattering to investigate the ‘dry’ reforming of methane over an alumina-supported nickel catalyst operating under conditions where filamentous carbon formation is prevalent

The use of CO2 in reforming methane to produce the industrial feedstock syngas is an economically and environmentally attractive reaction. An alumina-supported nickel catalyst active for this reaction additionally forms filamentous carbon. The catalyst is investigated by inelastic neutron scattering as well as elemental analysis, temperature-programmed oxidation, temperature-programmed hydrogenation, X-ray diffraction, transmission electron microscopy and Raman scattering. Isotopic substitution experiments, using 13CO2 for 12CO2, show the oxidant to contribute to the carbon retention evident with this sample. At steady-state operation, a carbon mass balance of 95 % is observed. A kinetic scheme is proposed to account for the trends observed

A non-parametric method for measuring the local dark matter density

We present a new method for determining the local dark matter density using kinematic data for a population of tracer stars. The Jeans equation in the $z$-direction is integrated to yield an equation that gives the velocity dispersion as a function of the total mass density, tracer density, and the tilt term that describes the coupling of vertical and radial motions. We then fit a dark matter mass profile to tracer density and velocity dispersion data to derive credible regions on the vertical dark matter density profile. Our method avoids numerical differentiation, leading to lower numerical noise, and is able to deal with the tilt term while remaining one dimensional. In this study we present the method and perform initial tests on idealised mock data. We also demonstrate the importance of dealing with the tilt term for tracers that sample $\gtrsim 1$ kpc above the disc plane. If ignored, this results in a systematic underestimation of the dark matter density.Comment: V2: Improved tracer density description; increased number of mocks to explore outliers; corrected sign error in the (R, z) velocity dispersion; main conclusions unchanged. 19 pages, 14 figure