Can qualitative and quantitative methods serve complementary purposes for policy research?

Qualitative and quantitative methods in social science research have long been separate spheres with little overlap. However, recent innovations have highlighted the complementarity of qualitative and quantitative approaches. The Accra Food and Nutrition Security Study was designed to incorporate the participation of a variety of constituencies in the research, and to rely on a variety of approaches — both qualitative and quantitative — to data collection and analysis. This paper reviews the way in which qualitative and quantitative methods were used in the Accra study. The argument of the paper is that the complementary use of qualitative and quantitative approaches provides a greater range of insights and perspectives and permits triangulation or the confirmation of findings by different methods, which improves the overall validity of results, and makes the study of greater use to the constituencies to which it was intended to be addressed. But the search for truly complementary methods presents substantial challenges as well. These include extra costs, both in financial and human terms, ethical dilemmas regarding follow-up, and the need for teamwork and respect for different methodological and epistemological positions.Nutrition Research. ,Social sciences Methodology. ,

Measuring food insecurity

Defining and interpreting food security, and measuring it in reliable, valid and cost-effective ways, have proven to be stubborn problems facing researchers and programs intended to monitor food security risks. This paper briefly reviews the conceptual and methodological literature on food insecurity measurement, describes a particular method for distinguishing and measuring short-term food insecurity at the household level, and discusses ways of generalizing the method. The method developed enumerates the frequency and severity of strategies relied on by urban households when faced with a short-term insufficiency of food. This method goes beyond more commonly-used measures of caloric consumption to incorporate vulnerability elements of food insecurity as well as the deliberate actions of household decisionmakers when faced with food insufficiency.food security ,Research Methodology ,

Volatility transformation in a multi-curve setting applied to caps and swaptions

Includes bibliographical referencesThe effects of the 2007-08 financial crisis have resulted in a sharp change in the way interest rate markets are viewed as well as modelled. As a result of the crisis, the general market framework has transitioned from a single curve framework to what is commonly known as the 'multiple-curve' framework. In addition to this, there is debate as to which curve to use for discounting. This dissertation will initially aim to give a succinct, yet thorough overview of the changes affecting interest rate modelling as a result of the financial crisis. In particular pricing methods that are consistent with the multi-curve framework are presented. Adaptations of the popular Libor Market Model (LMM) and Stochastic Alpha-Beta-Rho (SABR) consistent with the new market framework are also presented. The second aim of the dissertation is to outline and implement methods of transforming volatilities within this new market framework. The market quotes available for caps/floors and swaptions often assume a particular payment tenor, for example swaption volatilities are typically quoted assuming payment legs of six months. As such, if one wanted to price an identical swaption based on payment legs of three months, or even monthly payments, some form of transformation is needed. The methods presented and implemented are largely based on the work of Kienitz (2013). The methods described are implemented to transform six month cap and swaption volatility surfaces to three month surfaces

Does urban agriculture help prevent malnutrition?

Previous research has suggested that urban agriculture has a positive impact on the household food security and nutritional status of low-socioeconomic status groups in cities in Sub-Saharan Africa, but a formal test of the link between semisubsistence urban food production and nutritional status has not accompanied these claims. This paper seeks to redress this gap in the growing literature on urban agriculture through an analysis of the determinants of the nutritional status of children under five in Kampala, Uganda, where roughly one-third of all households in the sample engage in some form of urban agriculture. When controlling for other individual child, maternal, and household characteristics, these data indicate that urban agriculture has a positive, significant association with higher nutritional status of children, particularly height-for-age. Several pathways by which this relationship is manifested are suggested, and the implications of these results for urban food and nutrition policy and urban management are briefly discussed.Food policies. ,Urban agriculture. ,Food security Household. ,Children Nutrition. ,Nutritional status ,

Field Disease Incidence, Fungal Collection, and Evaluation of Koch\u27s Postulates with Isolated Fungi from Giant Miscanthus (Miscanthus X Giganteus) in Mississippi

The establishment of perennial grasses as biomass crops has increased the production acreage of giant miscanthus (Miscanthus x gigantues Greef et Deu, MXG). Yield loss and establishment failure could be detrimental to the sustainable production of this crop, and therefore, exploitation of differentiation in cultivar response to fungal diseases could be a key management strategy. A study was initiated in 2010 to evaluate MXG cultivars for foliar disease incidence (FDI) and compare to switchgrass (Panicum virgatum L., SG) cultivars, isolate and identify fungi from symptomatic leaf material, and demonstrate through Koch’s postulates the ability of these fungi to incite symptoms observed in the field. Giant miscanthus FDI ratings were similar between MXG cultivars, but significantly lower when compared to SG cultivars. Thirty genera of fungi were identified from fungal collections, and 16 pathogenic genera were isolated. Twelve isolates were selected and four were demonstrated to be pathogenic on Mxg

Light storage and control of photon-photon interactions in a cold Rydberg gas

The effect of strong interatomic interactions on an optical field stored in Rydberg states of a cold atomic gas is investigated. Due to their large dipole moments Rydberg atoms interact very strongly with each other. The strength of these interactions can be significant over length scales of several microns. An effect known as dipole blockade leads to a suppression in the number of Rydberg excitations supported in a medium of finite size. The experiments described in this thesis aim to exploit this effect to create a medium with a non-linear response which occurs at the level of single-photons. A cold atomic cloud is tightly confined such that only a few Rydberg excitations are supported. It is shown that the dipole blockade phenomenon leads to strong photon-photon interactions, resulting in the generation of quantum states of light. A microwave field is used to control the strength and range over which the interactions between the stored optical photons occur. In addition, it is shown that the propagation of the optical field through the medium is non-trivial. Preliminary evidence is presented suggesting that the slow-light group delay in the medium is dependent on the number of propagating photons

A molecular dynamics simulation of the effect of shear on molecular orientation

The focus of this work is the investigation of the effect of shear produced by buoyancy-induced convection on the orientation of rod-like molecules. The prob-lem is a mathematical simulation of a physical problem dealing with the growth of a polymer film which is under examination for use in fiber optic communication. The Molecular Dynamics simulation method was employed to solve the problem. A computer program was developed to implement the simulation and the details of the simulation development are discussed. The results of the atomic simulations that were used to validate the code are presented first. The simulation results for molecules and mixtures of molecules and atoms are then presented. It was determined that the shear caused by the velocity field does have an effect on the orientation of the rod-like molecules. However, the magnitude of this effect was seen to be sensitive to the type of the molecule, the concentration of the solution, and the properties of the wall

Field Disease Incidence, Fungal Collection, and Evaluation of Koch\u27s Postulates with Isolated Fungi from Giant Miscanthus (Miscanthus X Giganteus) in Mississippi

The establishment of perennial grasses as biomass crops has increased the production acreage of giant miscanthus (Miscanthus x gigantues Greef et Deu, MXG). Yield loss and establishment failure could be detrimental to the sustainable production of this crop, and therefore, exploitation of differentiation in cultivar response to fungal diseases could be a key management strategy. A study was initiated in 2010 to evaluate MXG cultivars for foliar disease incidence (FDI) and compare to switchgrass (Panicum virgatum L., SG) cultivars, isolate and identify fungi from symptomatic leaf material, and demonstrate through Koch’s postulates the ability of these fungi to incite symptoms observed in the field. Giant miscanthus FDI ratings were similar between MXG cultivars, but significantly lower when compared to SG cultivars. Thirty genera of fungi were identified from fungal collections, and 16 pathogenic genera were isolated. Twelve isolates were selected and four were demonstrated to be pathogenic on Mxg