Origins of the amphiploid species Brassica napus L. investigated by chloroplast and nuclear molecular markers

Background: The amphiploid species Brassica napus (oilseed rape, Canola) is a globally important oil crop yielding food, biofuels and industrial compounds such as lubricants and surfactants. Identification of the likely ancestors of each of the two genomes (designated A and C) found in B. napus would facilitate incorporation of novel alleles from the wider Brassica genepool in oilseed rape crop genetic improvement programmes. Knowledge of the closest extant relatives of the genotypes involved in the initial formation of B. napus would also allow further investigation of the genetic factors required for the formation of a stable amphiploid and permit the more efficient creation of fully fertile re-synthesised B. napus. We have used a combination of chloroplast and nuclear genetic markers to investigate the closest extant relatives of the original maternal progenitors of B. napus. This was based on a comprehensive sampling of the relevant genepools, including 83 accessions of A genome B. rapa L. (both wild and cultivated types), 94 accessions of B. napus and 181 accessions of C genome wild and cultivated B. oleracea L. and related species. Results: Three chloroplast haplotypes occurred in B. napus. The most prevalent haplotype (found in 79% of accessions) was not present within the C genome accessions but was found at low frequencies in B. rapa. Chloroplast haplotypes characteristic of B. napus were found in a small number of wild and weedy B. rapa populations, and also in two accessions of cultivated B. rapa 'brocoletto'. Whilst introgression of the B. napus chloroplast type in the wild and weedy B. rapa populations has been proposed by other studies, the presence of this haplotype within the two brocoletto accessions is unexplained. Conclusions: The distribution of chloroplast haplotypes eliminates any of the C genome species as being the maternal ancestor of the majority of the B. napus accessions. The presence of multiple chloroplast haplotypes in B. napus and B. rapa accessions was not correlated with nuclear genetic diversity as determined by AFLPs, indicating that such accessions do not represent recent hybrids. Whilst some chloroplast diversity observed within B. napus can be explained by introgression from inter-specific crosses made during crop improvement programmes, there is evidence that the original hybridisation event resulting in to B. napus occurred on more than one occasion, and involved different maternal genotypes

Market Power in the Carbonated Soft Drink Industry

We investigate the strategic pricing for leading brands sold in the carbonated soft drink (CSD) market in the context of a flexible demand specification (i.e. random parameter nested logit) and a structural pricing equation. Our approach does not rely upon the often used ad hoc linear approximations to demand and profit-maximizing first-order conditions. We estimate the structural pricing equation using four different estimators (i.e. OLS, LIML, 2SLS, and GMM) and compare the implied deviation from Bertrand-Nash competition. Our results suggest that retailers, on average, price CSD brands below their cost, likely a result of the competitive retailing environment. We also find CSD wholesalers price their brands significantly more cooperatively than Bertrand-Nash would suggest, thus inflating profits.Market Power, Carbonated Soft Drinks, Econometrics, LIML, Agribusiness, Agricultural and Food Policy, Demand and Price Analysis, Industrial Organization,

Consumer Impact of Animal Welfare Regulation in the California Poultry Industry

This study examines the consumer welfare impact of animal welfare legislation mandating cage-free egg production in California. We estimate California egg consumers’ willingness to pay (WTP) for cage-free eggs using household-level purchase data and compare the implied premium to higher production costs when calculating the potential change in consumer surplus. Our findings suggest that larger households and/or households with limited means are most likely to be affected. Furthermore, the implied welfare loss for consumers is approximately $106 million. Although consumers value cage-free eggs, higher production costs result in a net welfare loss to consumers. One implication of this finding is that a clear labeling practice may be a more efficient way to motivate animal welfare and non-cage systems.animal welfare regulation, California poultry, egg prices, egg supply, hen housing, mixed logit, willingness to pay, Livestock Production/Industries,

Measures of Brand Loyalty

Though brand loyalty has been studied extensively in the marketing literature, the relationship between brand loyalty and equilibrium pricing strategies is not well understood. Designing sales pricing strategies involves two key decisions: the percentage reduction in price from the existing price point, and the number or frequency of promotions within a category or for a specific product. These decisions, in turn, are critically dependent upon how many consumers can be convinced to switch to a brand by temporarily reducing its price, and how many are instead brand loyal. Theoretical models of how the size and strength of brand loyalty influence optimal promotion strategies have been developed, but there are no rigorous tests of their hypotheses. We test how brand loyalty impacts promotion strategies for a frequently purchased consumer package good category. Our results largely confirm that retailers often promote many brands simultaneously and that depth and breadth can be complementary.Consumer/Household Economics, Food Consumption/Nutrition/Food Safety, Marketing,

Media Advertising and Ballot Initiatives: An Experimental Analysis

Marketing,

Commodity Price Pass-Through in Differentiated Retail Food Markets

Prices for nearly all basic commodity rose at unprecedented rates throughout early 2008, only to fall nearly as fast as financial markets and global economies began to collapse. Rising food prices in 2008 led to concerns that commodity price spikes would lead to more general food inflation, but by early 2009 interest focused more on the seeming inability of food prices to fall back down with commodity prices. This study provides an empirical investigation into the pass-through of commodity prices to retail prices for two different types of food products: potatoes and fluid milk. The results show that pass-through depends on the nature of the food in question, but is generally consistent with theoretical models of pricing by sellers of multiple, differentiated products. In particular, pass-through rates tend to be lower for processed (differentiated) products during periods of falling input prices than when input prices are rising. For less processed products, pass-through tends to be higher during regimes of both rising and falling input prices. Our results show that pass-through depends on the degree of pricing power possessed by all channel members and, more generally, suggest a nuanced approach to understanding retail food price inflation.commodity prices, conduct, industrial organization, inflation, market power, nested logit, pass-through, random parameters model, Consumer/Household Economics, Demand and Price Analysis, Industrial Organization, C35, D12, D43, L13, L41, Q13,

Media Advertising and Ballot Initiatives: An Experimental Analysis

Spending on political advertising increases with every election cycle, not only for congressional or presidential candidates, but also for state-level ballot initiatives. There is little research in marketing, however, on the effectiveness of political advertising at this level. In this study, we conduct an experimental analysis of advertisements used during the 2008 campaign to mandate new animal welfare standards in California (Proposition 2). Using subjects' willingness to pay for cage-free eggs as a proxy for their likely voting behavior, we investigate whether advertising provides real information to likely voters, and thus sharpens their existing attitudes toward the issue, or whether advertising can indeed change preferences. We find that advertising in support of Proposition 2 was more effective in raising subjects' willingness to pay for cage-free eggs than ads in opposition were in reducing it, but we also find that ads in support of the measure reduce the dispersion of preferences and thus polarize attitudes toward the initiative. More generally, political ads are found to contain considerably more "hype" than "real information" in the sense of Johnson and Myatt (2006).Animal Welfare, Proposition 2, Cage Free eggs, Willingness to Pay, BDM auction, Political Advertising, Agribusiness, Agricultural and Food Policy, Demand and Price Analysis, Marketing, Political Economy, Production Economics, Public Economics,

Who is sowing our seeds? A systematic review of the use of plant genetic resources in research

Collections of plant genetic resources managed by genebanks function to conserve the range of genetic diversity present in crop genepools. They can facilitate access to valuable allelic variation for both plant breeders and researchers who are able to request germplasm for use in crop improvement and both basic and applied scientific research. The direct impact of genebank collections is often unclear as downstream uses of germplasm samples may not be reported back to the genebank of origin. This study aims to systematically review scientific use of germplasm using the UK Vegetable Genebank (UKVGB) as a model. Between the years of 1980–2016, a total of 271 publications were identified as using UKVGB material. The frequency of publications and the international nature of use increased significantly over the time period studied. Accessions directly sourced from the UKVGB made up the majority of material used by researchers, but material from research-derived resources such as differential sets and core collections or diversity sets have also been used. Resistance to pests and diseases and genetic diversity were the main topics of study although germplasm was used to address a wide range of other research questions. Genebanks such as UKVGB provide an essential resource of allelic diversity in crop genepools which supports a diverse range of research projects. The utilisation of these plant genetic resources has increased over time, contributing to a substantial number of publications. Developments in sequencing technologies have no doubt played a part as larger numbers of accessions can be utilized in a single experiment, but the increase also no doubt reflects a greater interest in the use of allelic diversity to overcome challenges in crop improvement and research

Lessons from obesity prevention for the prevention of mental disorders: The primordial prevention approach

Background: Emerging evidence supports a relationship between risk factors for obesity and the genesis of the common mental disorders, depression and anxiety. This suggests common mental disorders should be considered as a form of non-communicable disease, preventable through the modification of lifestyle behaviours, particularly diet and physical activity.Discussion: Obesity prevention research since the 1970\u27s represents a considerable body of knowledge regarding strategies to modify diet and physical activity and so there may be clear lessons from obesity prevention that apply to the prevention of mental disorders. For obesity, as for common mental disorders, adolescence represents a key period of vulnerability. In this paper we briefly discuss relationships between modifiable lifestyle risk factors and mental health, lifestyle risk factor interventions in obesity prevention research, the current state of mental health prevention, and the implications of current applications of systems thinking in obesity prevention research for lifestyle interventions.Summary: We propose a potential focus for future mental health promotion interventions and emphasise the importance of lessons available from other lifestyle modification intervention programmes

Polynomial Time Algorithms for Branching Markov Decision Processes and Probabilistic Min(Max) Polynomial Bellman Equations

We show that one can approximate the least fixed point solution for a multivariate system of monotone probabilistic max(min) polynomial equations, referred to as maxPPSs (and minPPSs, respectively), in time polynomial in both the encoding size of the system of equations and in log(1/epsilon), where epsilon > 0 is the desired additive error bound of the solution. (The model of computation is the standard Turing machine model.) We establish this result using a generalization of Newton's method which applies to maxPPSs and minPPSs, even though the underlying functions are only piecewise-differentiable. This generalizes our recent work which provided a P-time algorithm for purely probabilistic PPSs. These equations form the Bellman optimality equations for several important classes of infinite-state Markov Decision Processes (MDPs). Thus, as a corollary, we obtain the first polynomial time algorithms for computing to within arbitrary desired precision the optimal value vector for several classes of infinite-state MDPs which arise as extensions of classic, and heavily studied, purely stochastic processes. These include both the problem of maximizing and mininizing the termination (extinction) probability of multi-type branching MDPs, stochastic context-free MDPs, and 1-exit Recursive MDPs. Furthermore, we also show that we can compute in P-time an epsilon-optimal policy for both maximizing and minimizing branching, context-free, and 1-exit-Recursive MDPs, for any given desired epsilon > 0. This is despite the fact that actually computing optimal strategies is Sqrt-Sum-hard and PosSLP-hard in this setting. We also derive, as an easy consequence of these results, an FNP upper bound on the complexity of computing the value (within arbitrary desired precision) of branching simple stochastic games (BSSGs)