Spider phobics more easily see a spider in morphed schematic pictures

Background: Individuals with social phobia are more likely to misinterpret ambiguous social situations as more threatening, i.e. they show an interpretive bias. This study investigated whether such a bias also exists in specific phobia. Methods: Individuals with spider phobiaor social phobia, spider aficionados and non-phobic controls saw morphed stimuli that gradually transformed from a schematic picture of a flower into a schematic picture of a spider by shifting the outlines of the petals until they turned into spider legs. Participants' task was to decide whether each stimulus was more similar to a spider, a flower or to neither object while EEG was recorded. Results: An interpretive bias was found in spider phobia on a behavioral level: with the first opening of the petals of the flower anchor, spider phobics rated the stimuli as more unpleasant and arousing than the control groups and showed an elevated latent trait to classify a stimulus as a spider and a response-time advantage for spider-like stimuli. No cortical correlates on the level of ERPs of this interpretive bias could be identified. However, consistent with previous studies, social and spider phobic persons exhibited generally enhanced visual P1 amplitudes indicative of hypervigilance in phobia. Conclusion: Results suggest an interpretive bias and generalization of phobia-specific responses in specific phobia. Similar effects have been observed in other anxiety disorders, such as social phobia and posttraumatic stress disorder. © 2007 Kolassa et al; licensee BioMed Central Ltd

Retail forecasting: research and practice

This paper first introduces the forecasting problems faced by large retailers, from the strategic to the operational, from the store to the competing channels of distribution as sales are aggregated over products to brands to categories and to the company overall. Aggregated forecasting that supports strategic decisions is discussed on three levels: the aggregate retail sales in a market, in a chain, and in a store. Product level forecasts usually relate to operational decisions where the hierarchy of sales data across time, product and the supply chain is examined. Various characteristics and the influential factors which affect product level retail sales are discussed. The data rich environment at lower product hierarchies makes data pooling an often appropriate strategy to improve forecasts, but success depends on the data characteristics and common factors influencing sales and potential demand. Marketing mix and promotions pose an important challenge, both to the researcher and the practicing forecaster. Online review information too adds further complexity so that forecasters potentially face a dimensionality problem of too many variables and too little data. The paper goes on to examine evidence on the alternative methods used to forecast product sales and their comparative forecasting accuracy. Many of the complex methods proposed have provided very little evidence to convince as to their value, which poses further research questions. In contrast, some ambitious econometric methods have been shown to outperform all the simpler alternatives including those used in practice. New product forecasting methods are examined separately where limited evidence is available as to how effective the various approaches are. The paper concludes with some evidence describing company forecasting practice, offering conclusions as to the research gaps but also the barriers to improved practice

Cognitive change is more positively associated with an active lifestyle than with training interventions in older adults at risk of dementia: a controlled interventional clinical trial

Background: While observational studies show that an active lifestyle including cognitive, physical, and social activities is associated with a reduced risk of cognitive decline and dementia, experimental evidence from corresponding training interventions is more inconsistent with less pronounced effects. The aim of this study was to evaluate and compare training- and lifestyle-related changes in cognition. This is the first study investigating these associations within the same time period and sample. Methods: Fifty-four older adults at risk of dementia were assigned to 10 weeks of physical training, cognitive training, or a matched wait-list control condition. Lifestyle was operationalized as the variety of self-reported cognitive, physical, and social activities before study participation. Cognitive performance was assessed with an extensive test battery prior to and after the intervention period as well as at a 3-month follow-up. Composite cognition measures were obtained by means of a principal component analysis. Training- and lifestyle-related changes in cognition were analyzed using linear mixed effects models. The strength of their association was compared with paired t-tests. Results: Neither training intervention improved global cognition in comparison to the control group (p = .08). In contrast, self-reported lifestyle was positively associated with benefits in global cognition (p < .001) and specifically in memory (p < .001). Moreover, the association of an active lifestyle with cognitive change was significantly stronger than the benefits of the training interventions with respect to global cognition (ps < .001) and memory (ps < .001). Conclusions: The associations of an active lifestyle with cognitive change over time in a dementia risk group were stronger than the effects of short-term, specific training interventions. An active lifestyle may differ from training interventions in dosage and variety of activities as well as intrinsic motivation and enjoyment. These factors might be crucial for designing novel interventions, which are more efficient than currently available training interventions

Forecasting: theory and practice

Forecasting has always been in the forefront of decision making and planning. The uncertainty that surrounds the future is both exciting and challenging, with individuals and organisations seeking to minimise risks and maximise utilities. The lack of a free-lunch theorem implies the need for a diverse set of forecasting methods to tackle an array of applications. This unique article provides a non-systematic review of the theory and the practice of forecasting. We offer a wide range of theoretical, state-of-the-art models, methods, principles, and approaches to prepare, produce, organise, and evaluate forecasts. We then demonstrate how such theoretical concepts are applied in a variety of real-life contexts, including operations, economics, finance, energy, environment, and social good. We do not claim that this review is an exhaustive list of methods and applications. The list was compiled based on the expertise and interests of the authors. However, we wish that our encyclopedic presentation will offer a point of reference for the rich work that has been undertaken over the last decades, with some key insights for the future of the forecasting theory and practice

Can we obtain valid benchmarks from published surveys of forecast accuracy?

Organizations often seek benchmarks to judge the success of their forecasts. Reliable benchmarks would allow the company or agency to see if it has improved upon industry standards and to evaluate whether investment of additional resources in forecasting would be money well spent. But can the existing benchmark surveys be trusted? “No,” says Stephan Kolassa, who has analyzed the surveys and found them seriously deficient. In this article Stephan explains the many problems that plague benchmark surveys and advises that companies should redirect their search from external to internal benchmarks since the latter provide a better representation of the processes and targets the company has in place

C*-invariant elliptic fibrations

Let X be a two-dimensional and Y a one-dimensional complex manifold. Consider a proper, connected, surjective holomorphic mapping p: X->Y. Assume that the inverse images of regular values of p (the regular fibers) are elliptic curves. Consider further a holomorphic action of the group of units C* of the complex numbers C on X such that p is invariant. Then p: X->Y is a C*-invariant elliptic fibration. Glas and Hausen showed that there are exactly two types of singular fibers: multiple elliptic curves (in Kodaira's classification fibers of type mI0 with m>1) and cycles of rational curves with or without multiplicity (fibers of type mIb with m>=1 and b>=1). First, we recall the theory of holomorphic C*-actions on complex lines and surfaces and the results of Glas and Hausen on C*-invariant elliptic fibrations with critical fibers with multiplicity one. Then we approach the open question of multiple critical fibers. We construct a C*-invariant elliptic fibration with a critical fiber of type mI0. Under a technical condition on the isotropy of the critical fiber, this modelclassifies all C*-invariant elliptic fibrations in the neighborhood of a mI0-type fiber up to equivariant biholomorphy. In a separate chapter, we give a short introduction to the theory of toric varieties. We then use toric varieties to generalize a local model of a mIb-type fiber due to Glas and Hausen to the case of multiplicities. inally, we give some more results of Glas and Hausen. If all singular fibers of a C*-invariant elliptic fibration are of multiplicity one, the fibration can be globally classified up to equivariant biholomorph