Evaluation of dietary diversity scores for assessment of micronutrient intake and food security in developing countries

Micronutrient malnutrition and food insecurity are widespread global public health problems. Micronutrient deficiencies affect one-third of the global population. Household food insecurity, often results in monotonous diets, a contributing factor to malnutrition. Consuming a varied diet comprised of diversity across food groups is a recommended approach to achieving nutritional requirements. Many organizations promote the collection of information on dietary diversity to inform food security and nutritional assessments, but there is not an agreed upon set of indicators used for this purpose. Simple, standardized diet-based indicators are needed to assess, monitor and evaluate individual micronutrient intake and household food security. This thesis has a two-fold aim i) to examine relationships between dietary diversity and adequate intake of micronutrients and ii) to consider outstanding methodological questions. These include, determining an appropriate cut-point for (in)adequate intake of micronutrients from the diet and the effect of length of recall period on characterizing dietary patterns. The association between probability of adequate micronutrient intake and individual dietary scores was determined by secondary analysis of data sets of non-breastfed Filipino children (n=2805, 2-5.9y), South African children (n=2200, 1-8y), and urban Malian women (n=102, 15-49y). Dietary diversity scores were positively and significantly correlated with intake of micronutrients, with correlation coefficients of 0.36, 0.63, and 0.33 in the Philippines, South Africa, and Mali respectively. Using a minimum quantity for a food group to count in the score improved the correlations to 0.44 in the Philippines and 0.48 in Mali. The best score cut-offs for a dichotomous indicator of inadequate intake of micronutrients were four and six food groups in South Africa and six in the Philippines. In Mali, five or more food groups was the best cut-off point for increased mean probability of micronutrient adequacy. In Mali dietary diversity scores using six and nine food groups had slightly higher correlations and indicator performance than scores based on thirteen or twenty-one food groups. Differences in household-level dietary patterns over one and seven day recall periods were tested through secondary analysis in Somalia (n=430 hh), Burkina Faso (n=3640 hh), Lao PDR (n=3913 hh) and Northern Uganda (n=1956 ). In Somalia, the median dietary diversity score was four for both a one day and seven day recall period. The main food groups consumed by fifty percent or more of households in the lowest dietary diversity tertile were cereals, sugar and oil for both recall periods. The dietary patterns based on food group consumption using score tertiles in Burkina Faso, Lao PDR and Northern Uganda were similar for one or seven days. This thesis shows that dietary diversity scores are acceptable indicators of micronutrient intake from the diet. Requiring a minimum quantity of consumption for a food group to count in the score is better, but jeopardizes simplicity. The best cut-off for a dichotomous indicator differed across studies, but fell within the range of four to six food groups for predicting poor intake in children and five or more food groups to predict higher probability of adequate intake in women of reproductive age. Cost implications of misclassification and social unacceptability of false results are low for this indicator. For the purposes of characterizing dietary patterns of households at population level a one day recall period is sufficient. The simplicity of data collection and analysis of indicators of dietary diversity should enable more widespread and repeated collection of information on dietary intake in resource constrained, food insecure environments. Areas for further research include, the added value of assigning weights to food groups and studies in populations with higher average micronutrient intakes to better define an appropriate cut-point for a dichotomous indicator. It is recommended that dietary diversity scores be incorporated as monitoring and evaluation tools in food security and nutrition assessments at national level and below. <br/

Fitting a sum of exponentials to lattice correlation functions using a non-uniform prior

Excited states are extracted from lattice correlation functions using a non-uniform prior on the model parameters. Models for both a single exponential and a sum of exponentials are considered, as well as an alternate model for the orthogonalization of the correlation functions. Results from an analysis of torelon and glueball operators indicate the Bayesian methodology compares well with the usual interpretation of effective mass tables produced by a variational procedure. Applications of the methodology are discussed.Comment: 12 pages, 8 figures, 8 tables, major revision, final versio

Optimal designs for rational function regression

We consider optimal non-sequential designs for a large class of (linear and nonlinear) regression models involving polynomials and rational functions with heteroscedastic noise also given by a polynomial or rational weight function. The proposed method treats D-, E-, A-, and $\Phi_p$-optimal designs in a unified manner, and generates a polynomial whose zeros are the support points of the optimal approximate design, generalizing a number of previously known results of the same flavor. The method is based on a mathematical optimization model that can incorporate various criteria of optimality and can be solved efficiently by well established numerical optimization methods. In contrast to previous optimization-based methods proposed for similar design problems, it also has theoretical guarantee of its algorithmic efficiency; in fact, the running times of all numerical examples considered in the paper are negligible. The stability of the method is demonstrated in an example involving high degree polynomials. After discussing linear models, applications for finding locally optimal designs for nonlinear regression models involving rational functions are presented, then extensions to robust regression designs, and trigonometric regression are shown. As a corollary, an upper bound on the size of the support set of the minimally-supported optimal designs is also found. The method is of considerable practical importance, with the potential for instance to impact design software development. Further study of the optimality conditions of the main optimization model might also yield new theoretical insights.Comment: 25 pages. Previous version updated with more details in the theory and additional example

Novel Approach to Confront Electroweak Data and Theory

A novel approach to study electroweak physics at one-loop level in generic ${\rm SU(2)_L \times U(1)_Y}$ theories is introduced. It separates the 1-loop corrections into two pieces: process specific ones from vertex and box contributions, and universal ones from contributions to the gauge boson propagators. The latter are parametrized in terms of four effective form factors $\bar{e}^2(q^2)$, $\bar{s}^2(q^2)$, $\bar{g}_Z^2(q^2)$ and $\bar{g}_W^2 (q^2)$ corresponding to the $\gamma\gamma$, $\gamma Z$, $ZZ$ and $WW$ propagators. Under the assumption that only the Standard Model contributes to the process specific corrections, the magnitudes of the four form factors are determined at $q^2=0$ and at q^2=\mmz by fitting to all available precision experiments. These values are then compared systematically with predictions of ${\rm SU(2)_L \times U(1)_Y}$ theories. In all fits \alpha_s(\mz) and \bar{\alpha}(\mmz) are treated as external parameters in order to keep the interpretation as flexible as possible. The treatment of the electroweak data is presented in detail together with the relevant theoretical formulae used to interpret the data. No deviation from the Standard Model has been identified. Ranges of the top quark and Higgs boson masses are derived as functions of \alpha_s(\mz) and \bar{\alpha}(\mmz). Also discussed are consequences of the recent precision measurement of the left-right asymmetry at SLC as well as the impact of a top quark mass and an improved $W$ mass measurement.Comment: 123 pages, LaTeX (33 figures available via anonymous ftp), KEK-TH-375, KEK preprint 93-159, KANAZAWA-94-19, DESY 94-002, YUMS 94-22, SNUTP 94-82, to be published in Z.Phys.

Local and Global Casimir Energies: Divergences, Renormalization, and the Coupling to Gravity

From the beginning of the subject, calculations of quantum vacuum energies or Casimir energies have been plagued with two types of divergences: The total energy, which may be thought of as some sort of regularization of the zero-point energy, $\sum\frac12\hbar\omega$, seems manifestly divergent. And local energy densities, obtained from the vacuum expectation value of the energy-momentum tensor, $\langle T_{00}\rangle$, typically diverge near boundaries. The energy of interaction between distinct rigid bodies of whatever type is finite, corresponding to observable forces and torques between the bodies, which can be unambiguously calculated. The self-energy of a body is less well-defined, and suffers divergences which may or may not be removable. Some examples where a unique total self-stress may be evaluated include the perfectly conducting spherical shell first considered by Boyer, a perfectly conducting cylindrical shell, and dilute dielectric balls and cylinders. In these cases the finite part is unique, yet there are divergent contributions which may be subsumed in some sort of renormalization of physical parameters. The divergences that occur in the local energy-momentum tensor near surfaces are distinct from the divergences in the total energy, which are often associated with energy located exactly on the surfaces. However, the local energy-momentum tensor couples to gravity, so what is the significance of infinite quantities here? For the classic situation of parallel plates there are indications that the divergences in the local energy density are consistent with divergences in Einstein's equations; correspondingly, it has been shown that divergences in the total Casimir energy serve to precisely renormalize the masses of the plates, in accordance with the equivalence principle.Comment: 53 pages, 1 figure, invited review paper to Lecture Notes in Physics volume in Casimir physics edited by Diego Dalvit, Peter Milonni, David Roberts, and Felipe da Ros

Using clustering of rankings to explain brand preferences with personality and socio-demographic variables

The primary aim of market segmentation is to identify relevant groups of consumers that can be addressed efficiently by marketing or advertising campaigns. This paper addresses the issue whether consumer groups can be identified from background variables that are not brand-related, and how much personality vs. socio-demographic variables contribute to the identification of consumer clusters. This is done by clustering aggregated preferences for 25 brands across 5 different product categories, and by relating socio-demographic and personality variables to the clusters using logistic regression and random forests over a range of different numbers of clusters. Results indicate that some personality variables contribute significantly to the identification of consumer groups in one sample. However, these results were not replicated on a second sample that was more heterogeneous in terms of socio-demographic characteristics and not representative of the brands target audience

Global Search for New Physics with 2.0/fb at CDF

Data collected in Run II of the Fermilab Tevatron are searched for indications of new electroweak-scale physics. Rather than focusing on particular new physics scenarios, CDF data are analyzed for discrepancies with the standard model prediction. A model-independent approach (Vista) considers gross features of the data, and is sensitive to new large cross-section physics. Further sensitivity to new physics is provided by two additional algorithms: a Bump Hunter searches invariant mass distributions for "bumps" that could indicate resonant production of new particles; and the Sleuth procedure scans for data excesses at large summed transverse momentum. This combined global search for new physics in 2.0/fb of ppbar collisions at sqrt(s)=1.96 TeV reveals no indication of physics beyond the standard model.Comment: 8 pages, 7 figures. Final version which appeared in Physical Review D Rapid Communication

The state of the Martian climate

60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio

Observation of a new chi_b state in radiative transitions to Upsilon(1S) and Upsilon(2S) at ATLAS

The chi_b(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4 fb^-1, these states are reconstructed through their radiative decays to Upsilon(1S,2S) with Upsilon->mu+mu-. In addition to the mass peaks corresponding to the decay modes chi_b(1P,2P)->Upsilon(1S)gamma, a new structure centered at a mass of 10.530+/-0.005 (stat.)+/-0.009 (syst.) GeV is also observed, in both the Upsilon(1S)gamma and Upsilon(2S)gamma decay modes. This is interpreted as the chi_b(3P) system.Comment: 5 pages plus author list (18 pages total), 2 figures, 1 table, corrected author list, matches final version in Physical Review Letter