The potential inefficiency of using marketing margins in applied commodity price analysis, forecasting and risk management

This paper examines the implications of using marketing margins in applied commodity price analysis. The marketing-margin concept has a long and distinguished history, but it has caused considerable controversy. This is particularly the case in the context of analyzing the distribution of research gains in multi-stage production systems. We derive optimal tax schemes for raising revenues to finance research and promotion in a downstream market, derive the rules for efficient allocation of the funds, and compare the rules with an without the marketing-margin assumption. Applying the methodology to quarterly time series on the Australian beef-cattle sector and, with several caveats, we conclude that, during the period 1978:2 - 1988:4, the Australian Meat and Livestock Corporation optimally allocated research resources.

Back to the margins in search of the core: "Foreign Land"'s geography of exclusion

The crisis of the national project in the early 1990s, caused by a short-lived but disastrous government, led Brazilian art cinema, for the first time, to look at itself as periphery and re-approach the old colonial center, Portugal. Terra estrangeira/Foreign Land (Walter Salles & Daniela Thomas, Brazil/Portugal, 1995), a film about Brazilian exiles in Portugal, is the best illustration of this perspective shift which provides a new sense of Brazil’s scale and position within a global context. Shot mainly on location in São Paulo, Lisbon and Cape Verde, it promotes the encounter of Lusophone peoples who find a common ground in their marginal situation. Rather than as a former empire, Portugal is defined by its situation at the edge of Europe and by beliefs such as Sebastianism, whose origins go back to the time when the country was dominated by Spain. As a result, notions of “core” or “center” are devolved to the realm of myth. The film’s carefully crafted dialogue combines Brazilian, Portuguese and Creole linguistic peculiarities into a common dialect of exclusion, while language puns trigger visual rhymes which refer back to the Cinema Novo (the Brazilian New Wave) repertoire and restage the imaginary of the discovery turned into unfulfilled utopia. The main characters also acquire historical resonances, as they are depicted as descendants of Iberian conquistadors turned into smugglers of precious stones in the present. Their activities define a circuit of international exchange which resonates with that of globalized cinema, a realm in which Foreign Land, made up of citations and homage to other cinemas, tries to retrieve a sense of belonging.

Back to the margins in search of the core: foreign land's geography of exclusion

The crisis of the national project in the early 1990s, caused by a short-lived but disastrous government, led Brazilian art cinema, for the first time, to look at itself as periphery and re-approach the old colonial centre, Portugal. Terra estrangeira/Foreign Land (Walter Salles & Daniela Thomas, Brazil/Portugal, 1995), a film about Brazilian exiles in Portugal, is the best illustration of this perspective shift aimed at providing a new sense of Brazil’s scale and position within a global context. Shot mainly on location in São Paulo, Lisbon and Cape Verde, it promotes the encounter of Lusophone peoples who find a common ground in their marginal situation. Even Portugal is defined by its location at the edge of Europe and by beliefs such as Sebastianism, whose origins go back to the time when the country was dominated by Spain. As a result, notions of ‘core’ or ‘centre’ are devolved to the realm of myth. The film’s carefully crafted dialogues combine Brazilian, Portuguese and Creole linguistic peculiarities into a common dialect of exclusion, while language puns trigger visual rhymes which refer back to the Cinema Novo (the Brazilian New Wave) repertoire and restage the imaginary of the discovery turned into unfulfilled utopia. The main characters also acquire historical resonances, as they are depicted as descendants of Iberian conquistadors turned into smugglers of precious stones in the present. Their activities define a circuit of international exchange which resonates with that of globalized cinema, a realm in which Foreign Land, made up of citations and homage to other cinemas, tries to retrieve a sense of belonging.

Whole-brain functional connectivity during emotional word classification in medication-free Major Depressive Disorder: abnormal salience circuitry and relations to positive emotionality

Major Depressive Disorder (MDD) has been associated with biased processing and abnormal regulation of negative and positive information, which may result from compromised coordinated activity of prefrontal and subcortical brain regions involved in evaluating emotional information. We tested whether patients with MDD show distributed changes in functional connectivity with a set of independently derived brain networks that have shown high correspondence with different task demands, including stimulus salience and emotional processing. We further explored if connectivity during emotional word processing related to the tendency to engage in positive or negative emotional states. In this study, 25 medication-free MDD patients without current or past comorbidity and matched controls (n=25) performed an emotional word-evaluation task during functional MRI. Using a dual regression approach, individual spatial connectivity maps representing each subject’s connectivity with each standard network were used to evaluate between-group differences and effects of positive and negative emotionality (extraversion and neuroticism, respectively, as measured with the NEO-FFI). Results showed decreased functional connectivity of the medial prefrontal cortex, ventrolateral prefrontal cortex, and ventral striatum with the fronto-opercular salience network in MDD patients compared to controls. In patients, abnormal connectivity was related to extraversion, but not neuroticism. These results confirm the hypothesis of a relative (para)limbic-cortical decoupling that may explain dysregulated affect in MDD. As connectivity of these regions with the salience network was related to extraversion, but not to general depression severity or negative emotionality, dysfunction of this network may be responsible for the failure to sustain engagement in rewarding behavior.

Comparison of pollinators and natural enemies: a meta-analysis of landscape and local effects on abundance and richness in crops

To manage agroecosystems for multiple ecosystem services, we need to know whether the management of one service has positive, negative, or no effects on other services. We do not yet have data on the interactions between pollination and pest-control services. However, we do have data on the distributions of pollinators and natural enemies in agroecosystems. Therefore, we compared these two groups of ecosystem service providers, to see if the management of farms and agricultural landscapes might have similar effects on the abundance and richness of both. In a meta-analysis, we compared 46 studies that sampled bees, predatory beetles, parasitic wasps, and spiders in fields, orchards, or vineyards of food crops. These studies used the proximity or proportion of non-crop or natural habitats in the landscapes surrounding these crops (a measure of landscape complexity), or the proximity or diversity of non-crop plants in the margins of these crops (a measure of local complexity), to explain the abundance or richness of these beneficial arthropods. Compositional complexity at both landscape and local scales had positive effects on both pollinators and natural enemies, but different effects on different taxa. Effects on bees and spiders were significantly positive, but effects on parasitoids and predatory beetles (mostly Carabidae and Staphylinidae) were inconclusive. Landscape complexity had significantly stronger effects on bees than it did on predatory beetles and significantly stronger effects in non-woody rather than in woody crops. Effects on richness were significantly stronger than effects on abundance, but possibly only for spiders. This abundance-richness difference might be caused by differences between generalists and specialists, or between arthropods that depend on non-crop habitats (ecotone species and dispersers) and those that do not (cultural species). We call this the ‘specialist-generalist’ or ‘cultural difference’ mechanism. If complexity has stronger effects on richness than abundance, it might have stronger effects on the stability than the magnitude of these arthropod-mediated ecosystem services. We conclude that some pollinators and natural enemies seem to have compatible responses to complexity, and it might be possible to manage agroecosystems for the benefit of both. However, too few studies have compared the two, and so we cannot yet conclude that there are no negative interactions between pollinators and natural enemies, and no trade-offs between pollination and pest-control services. Therefore, we suggest a framework for future research to bridge these gaps in our knowledge.

Occupying the margins: Labour integration and social exclusion in artisanal mining in Tanzania

This article examines the marginal position of artisanal miners in sub-Saharan Africa, and considers how they are incorporated into mineral sector change in the context of institutional and legal integration. Taking the case of diamond and gold mining in Tanzania, the concept of social exclusion is used to explore the consequences of marginalization on people's access to mineral resources and ability to make a living from artisanal mining. Because existing inequalities and forms of discrimination are ignored by the Tanzanian state, the institutionalization of mineral titles conceals social and power relations that perpetuate highly unequal access to resources. The article highlights the complexity of these processes, and shows that while legal integration can benefit certain wealthier categories of people, who fit into the model of an 'entrepreneurial small-scale miner', for others adverse incorporation contributes to socio-economic dependence, exploitation and insecurity. For the issue of marginality to be addressed within integration processes, the existence of local forms of organization, institutions and relationships, which underpin inequalities and discrimination, need to be recognized.

Sparse polynomial approximation in positive order Sobolev spaces with bounded mixed derivatives and applications to elliptic problems with random loading

In the present paper we study the approximation of functions with bounded mixed derivatives by sparse tensor product polynomials in positive order tensor product Sobolev spaces. We introduce a new sparse polynomial approximation operator which exhibits optimal convergence properties in L2 and tensorized View the MathML source simultaneously on a standard k-dimensional cube. In the special case k=2 the suggested approximation operator is also optimal in L2 and tensorized H1 (without essential boundary conditions). This allows to construct an optimal sparse p-version FEM with sparse piecewise continuous polynomial splines, reducing the number of unknowns from O(p2), needed for the full tensor product computation, to View the MathML source, required for the suggested sparse technique, preserving the same optimal convergence rate in terms of p. We apply this result to an elliptic differential equation and an elliptic integral equation with random loading and compute the covariances of the solutions with View the MathML source unknowns. Several numerical examples support the theoretical estimates.

Research practices that can prevent an inflation of false-positive rates

Recent studies have indicated that research practices in psychology may be susceptible to factors that increase false-positive rates, raising concerns about the possible prevalence of false-positive findings. The present article discusses several practices that may run counter to the inflation of false-positive rates. Taking these practices into account would lead to a more balanced view on the false-positive issue. Specifically, we argue that an inflation of false-positive rates would diminish, sometimes to a substantial degree, when researchers (a) have explicit a priori theoretical hypotheses, (b) include multiple replication studies in a single paper, and (c) collect additional data based on observed results. We report findings from simulation studies and statistical evidence that support these arguments. Being aware of these preventive factors allows researchers not to overestimate the pervasiveness of false-positives in psychology and to gauge the susceptibility of a paper to possible false-positives in practical and fair ways.

Making an effort to feel positive: insecure attachment in infancy predicts the neural underpinnings of emotion regulation in adulthood

Background: Animal research indicates that the neural substrates of emotion regulation may be persistently altered by early environmental exposures. If similar processes operate in human development then this is significant, as the capacity to regulate emotional states is fundamental to human adaptation. Methods: We utilised a 22-year longitudinal study to examine the influence of early infant attachment to the mother, a key marker of early experience, on neural regulation of emotional states in young adults. Infant attachment status was measured via objective assessment at 18-months, and the neural underpinnings of the active regulation of affect were studied using fMRI at age 22 years. Results: Infant attachment status at 18-months predicted neural responding during the regulation of positive affect 20-years later. Specifically, while attempting to up-regulate positive emotions, adults who had been insecurely versus securely attached as infants showed greater activation in prefrontal regions involved in cognitive control and reduced co-activation of prefrontal cortex and nucleus accumbens, consistent with relative inefficiency in the neural regulation of positive affect. Conclusions: Disturbances in the mother-infant relationship may persistently alter the neural circuitry of emotion regulation, with potential implications for adjustment in adulthood.

Autobiographical memory distributions for negative self-images: memories are organised around negative as well as positive aspects of identity

The relationship between developmental experiences, and an individual’s emerging beliefs about themselves and the world, is central to many forms of psychotherapy. People suffering from a variety of mental health problems have been shown to use negative memories when defining the self, however little is known about how these negative memories might be organised and relate to negative self-images. In two online studies with middle-aged (N = 18; Study 1) and young (N = 56; Study 2) adults, we found that participants’ negative self-images (e.g., I am a failure) were associated with sets of autobiographical memories that formed clustered distributions around times of self-formation, in much the same pattern as for positive self-images (e.g., I am talented). This novel result shows that highly organised sets of salient memories may be responsible for perpetuating negative beliefs about the self. Implications for therapy are discussed.

Prolonged marital stress is associated with short-lived responses to positive stimuli

Marital stress is associated with a higher incidence of psychiatric disorders, in particular major depression. One pathway through which marital stress may impact emotional health is by compromising emotion-responding processes. We examined a longitudinal sample of adults (N = 116; 59 males; 39–84 years) to verify how marital stress predicts reactivity to, and recovery from, emotional provocation. Individuals watched positive, neutral, and negative pictures while an objective measure of affective state, corrugator supercilii muscle activity, was recorded continuously. Our results indicate that marital stress is associated with short-lived responses to positive pictures, indexed by a less persistent decrease in corrugator activity after picture offset. Extending beyond the prior focus on negative emotional processes, these results suggest that social stress may impact health by influencing the time course of responding to positive events.

Comparative Analysis of ESBL-Positive Escherichia coli isolates from Animals and Humans from the UK, the Netherlands and Germany

The putative virulence and antimicrobial resistance gene contents of extended spectrum β-lactamase (ESBL)-positive E. coli (n=629) isolated between 2005 and 2009 from humans, animals and animal food products in Germany, The Netherlands and the UK were compared using a microarray approach to test the suitability of this approach with regard to determining their similarities. A selection of isolates (n=313) were also analysed by multilocus sequence typing (MLST). Isolates harbouring blaCTX-M-group-1 dominated (66%, n=418) and originated from both animals and cases of human infections in all three countries; 23% (n=144) of all isolates contained both blaCTX-M-group-1 and blaOXA-1-like genes, predominantly from humans (n=127) and UK cattle (n=15). The antimicrobial resistance and virulence gene profiles of this collection of isolates were highly diverse. A substantial number of human isolates (32%, n=87) did not share more than 40% similarity (based on the Jaccard coefficient) with animal isolates. A further 43% of human isolates from the three countries (n=117) were at least 40% similar to each other and to five isolates from UK cattle and one each from Dutch chicken meat and a German dog; the members of this group usually harboured genes such as mph(A), mrx, aac(6’)-Ib, catB3, blaOXA-1-like and blaCTX-M-group-1. forty-four per cent of the MLST-typed isolates in this group belonged to ST131 (n=18) and 22% to ST405 (n=9), all from humans. Among animal isolates subjected to MLST (n=258), only 1.2% (n=3) were more than 70% similar to human isolates in gene profiles and shared the same MLST clonal complex with the corresponding human isolates. The results suggest that minimising human-to-human transmission is essential to control the spread of ESBL-positive E. coli in humans.

Avoiding the dark side of positive online consumer reviews: enhancing reviews' usefulness for high risk-averse travelers

The influence of positive online consumer reviews on a traveler's decision making remains unclear. To better understand the perceived usefulness of online reviews, this study conducts two experiments using positive and negative online consumer reviews. Study results suggest that high risk-averse travelers find negative online reviews more useful than positive reviews. For positive online reviews, high-risk averse travelers feel expert reviewers' postings, travel product pictures, and well-known brand names enhance usefulness of the positive online reviews. These findings offer interesting implications for both marketing theory and practice.