Recent studies in Drosophila melanogaster of the protocadherins Dachsous and Fat suggest that they act as ligand and receptor, respectively, for an intercellular signaling pathway that influences tissue polarity, growth and gene expression, but the basis for signaling downstream of Fat has remained unclear. Here, we characterize functional relationships among D. melanogaster tumor suppressors and identify the kinases Discs overgrown and Warts as components of a Fat signaling pathway. fat, discs overgrown and warts regulate a common set of downstream genes in multiple tissues. Genetic experiments position the action of discs overgrown upstream of the Fat pathway component dachs, whereas warts acts downstream of dachs. Warts protein coprecipitates with Dachs, and Warts protein levels are influenced by fat, dachs and discs overgrown in vivo, consistent with its placement as a downstream component of the pathway. The tumor suppressors Merlin, expanded, hippo, salvador and mob as tumor suppressor also share multiple Fat pathway phenotypes but regulate Warts activity independently. Our results functionally link what had been four disparate groups of D. melanogaster tumor suppressors, establish a basic framework for Fat signaling from receptor to transcription factor and implicate Warts as an integrator of multiple growth control signals.

The dachs gene was first identified almost a century ago based on its requirements for appendage growth, but has been relatively little studied. Here, we describe the phenotypes of strong dachs mutations, report the cloning of the dachs gene, characterize the localization of Dachs protein, and investigate the relationship between Dachs and the Fat pathway. Mutation of dachs reduces, but does not abolish, the growth of legs and wings. dachs encodes an unconventional myosin that preferentially localizes to the membrane of imaginal disc cells. dachs mutations suppress the effects of fat mutations on gene expression, cell affinity and growth in imaginal discs. Dachs protein localization is influenced by Fat, Four-jointed and Dachsous, consistent with its genetic placement downstream of fat. However, dachs mutations have only mild tissue polarity phenotypes, and only partially suppress the tissue polarity defects of fat mutants. Our results implicate Dachs as a crucial downstream component of a Fat signaling pathway that influences growth, affinity and gene expression during development.

In the Drosophila wing, distal cells signal to proximal cells to induce the expression of Wingless, but the basis for this distal-to-proximal signaling is unknown. Here, we show that three genes that act together during the establishment of tissue polarity, fat, four-jointed and dachsous, also influence the expression of Wingless in the proximal wing. fat is required cell autonomously by proximal wing cells to repress Wingless expression, and misexpression of Wingless contributes to proximal wing overgrowth in fat mutant discs. Four-jointed and Dachsous can influence Wingless expression and Fat localization nonautonomously, consistent with the suggestion that they influence signaling to Fat-expressing cells. We also identify dachs as a gene that is genetically required downstream of fat, both for its effects on imaginal disc growth and for the expression of Wingless in the proximal wing. Our observations provide important support for the emerging view that Four-jointed, Dachsous and Fat function in an intercellular signaling pathway, identify a normal role for these proteins in signaling interactions that regulate growth and patterning of the proximal wing, and identify Dachs as a candidate downstream effector of a Fat signaling pathway.

This research validated a new 16-item brand image scale that captures cognitive, sensory, and affective dimensions (i.e., mystery, sensuality, intimacy) of tangible and intangible attributes of fashion brands. Three studies were conducted to develop a holistic, yet parsimonious, fashion brand image measure. The initial subthemes of brand image and representative items were based on a review of scholarly literature and industry-based information and on interview findings. Reliability and validity of the new scale were confirmed using data from 218 college students and a national sample of 2,373 respondents. Convergent and discriminant validity were supported through confirmatory factor analysis. Nomological validity was supported through testing a structural model containing the three brand image dimensions, Roberts' (2005) lovemarks experience, and brand equity variables. The new brand image scale is different from existing scales because it incorporates Roberts' industry-based perspective, including more comprehensive sensory and affective dimensions than found in past brand image scales. This study provides support for Roberts' lovemarks model and the contributors to brand equity, which has implications for theory and for marketing firms that endeavor to build an effective fashion brand image.

PurposeThe purpose of this study is to investigate whether and how the effects of cognitive, sensory and affective brand associations on brand love (a core driver of brand loyalty) differ by perceived brand origin (domestic vs imported) and identity expressiveness (low vs high) in two different national contexts.Design/methodology/approachThe data for this study were collected through an online survey in the US and China. A total of 711 responses (n = 362 for the US, n = 349 for China) were used for data analysis. A multiple-group structural equation modeling was used to test the hypotheses.FindingsCognitive and sensory associations are significant drivers of US consumers' brand love while affective associations are important for Chinese consumers' brand love. Also, perceived brand origin and identity expressiveness moderate the three brand associations–brand love relationship. For US consumers, cognitive associations significantly influence brand love for both domestic and imported brands, but sensory associations are important for domestic brand love. For Chinese consumers, affective associations significantly influence brand love for both domestic and imported brands, but cognitive associations are important for imported brand love. The impacts of the three brand associations on brand love differ by the degree of identity expressiveness.Research limitations/implicationsThis empirical study offers important insights into the differing effects of perceived brand origin and identity expressiveness in enhancing brand love across cultures in order to establish strong international brand equity.Originality/valueThis study contributes to the scarce cross-cultural research on brand equity by testing the extended brand equity model. The findings provide more specific, meaningful insights into the role of perceived brand origin and identity expressiveness, leading to more effective international brand management.

Over 3 billion people in the world use social media (Kemp 2018), and a recent consumer survey from eMarketer in 2017 forecasted that two-thirds of the US population will soon use two or more social networking sites in social media. Social networking sites are defined as online applications that give Internet users the ability to create a profile, share the profile with a list of other Internet users, and view information uploaded by those connections (Boyd and Ellison 2007). Social networking sites facilitate interactive communication among social media users through social sharing . For instance, in a brand's social media fan page, consumers interact not only with the brand but also with the brand's other customers. Consumers share their shopping experiences and recommend products and services based on their experiences. The information search and sharing processes in social media influence social media users' behaviors (eMarketer 2017;Mangold and Faulds 2009).

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The purpose of this article is to introduce a diffusion model for biological organisms that increase their motility when food or other resource is insufficient. It is shown in this paper that Fick's diffusion law does not explain such a starvation driven diffusion correctly. The diffusion model for nonuniform Brownian motion in Kim (Einstein's random walk and thermal diffusion, preprint http://amath.kaist.ac.kr/papers/Kim/31.pdf , 2013) is employed in this paper and a Fokker-Planck type diffusion law is obtained. Lotka-Volterra type competition systems with spatial heterogeneity are tested, where one species follows the starvation driven diffusion and the other follows the linear diffusion. In heterogeneous environments, the starvation driven diffusion turns out to be a better survival strategy than the linear one. Various issues such as the global asymptotic stability, convergence to an ideal free distribution, the extinction and coexistence of competing species are discussed.