988 research outputs found

    Complementing mass customization toolkits with user communities: How peer input improves customer self-design

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    In this article, the authors propose that the canonical customer-toolkit dyad in mass customization (MC) should be complemented with user communities. Many companies in various industries have begun to offer their customers the opportunity to design their own products online. The companies provide web-based MC toolkits which allow customers who prefer individualized products to tailor items such as sneakers, PCs, cars, kitchens, cereals, or skis to their specific preferences. Most existing MC toolkits are based on the underlying concept of an isolated, dyadic interaction process between the individual customer and the MC toolkit. Information from external sources is not provided. As a result, most academic research on MC toolkits has focused on this dyadic perspective. The main premise of this article is that novice MC toolkit users in particular might largely benefit from information given by other customers. The pioneering research conducted by Jeppesen (2005), Jeppesen and Frederiksen (2006), and Jeppesen and Molin (2003) has shown that customers in the computer gaming and digital music instruments industries are willing to support each other for the sake of efficient toolkit use (e.g., how certain toolkit functions work). Expanding on their work, this article provides evidence that peer assistance appears also extremely useful in the two other major phases of the customer's individual self-design process, namely the development of an initial idea and the evaluation of a preliminary design solution. Two controlled experiments were conducted in which 191 subjects used an MC toolkit in order to design their own individual skis. The authors find that during the phase of developing an initial idea, having access to other users' designs as potential starting points stimulates the integration of existing solution chunks into the problem-solving process, which indicates more systematic problem-solving behavior. Peer customer input also turned out to have positive effects on the evaluation of preliminary design solutions. Providing other customers' opinions on interim design solutions stimulated favorable problem-solving behavior, namely the integration of external feedback. The use of these two problem-solving heuristics in turn leads to an improved process outcome, that is, self-designed products which meet the preferences of the customers more effectively (measured in terms of perceived preference fit, purchase intention, and willingness to pay). These findings have important theoretical and managerial implications. (author's abstract

    Infection-associated type IV secretion systems of Bartonella and their diverse roles in host cell interaction

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    Type IV secretion systems (T4SSs) are transporters of Gram-negative bacteria that mediate interbacterial DNA transfer, and translocation of virulence factors into eukaryotic host cells. The α-proteobacterial genus Bartonella comprises arthropod-borne pathogens that colonize endothelial cells and erythrocytes of their mammalian reservoir hosts, thereby causing long-lasting intraerythrocytic infections. The deadly human pathogen Bartonella bacilliformis holds an isolated position in the Bartonella phylogeny as a sole representative of an ancestral lineage. All other species evolved in a separate ‘modern’ lineage by radial speciation and represent highly host-adapted pathogens of limited virulence potential. Unlike B. bacilliformis, the species of the modern lineage encode at least one of the closely related T4SSs, VirB/VirD4 or Vbh. These VirB-like T4SSs represent major host adaptability factors that contributed to the remarkable evolutionary success of the modern lineage. At the molecular level, the VirB/VirD4 T4SS was shown to translocate several effector proteins into endothelial cells that subvert cellular functions critical for establishing chronic infection. A third T4SS, Trw, is present in a sub-branch of the modern lineage. Trw does not translocate any known effectors, but produces multiple variant pilus subunits critically involved in the invasion of erythrocytes. The T4SSs laterally acquired by the bartonellae have thus adopted highly diverse functions during infection, highlighting their versatility as pathogenicity factors

    The Impact of; Bartonella; VirB/VirD4 Type IV Secretion System Effectors on Eukaryotic Host Cells

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    Bartonella; spp. are facultative intracellular pathogens that infect a wide range of mammalian hosts including humans. The VirB/VirD4 type IV secretion system (T4SS) is a key virulence factor utilized to translocate; Bartonella; effector proteins (Beps) into host cells in order to subvert their functions. Crucial for effector translocation is the C-terminal Bep intracellular delivery (BID) domain that together with a positively charged tail sequence forms a bipartite translocation signal. Multiple BID domains also evolved secondary effector functions within host cells. The majority of Beps possess an N-terminal filamentation induced by cAMP (FIC) domain and a central connecting oligonucleotide binding (OB) fold. FIC domains typically mediate AMPylation or related post-translational modifications of target proteins. Some Beps harbor other functional modules, such as tandem-repeated tyrosine-phosphorylation (EPIYA-related) motifs. Within host cells the EPIYA-related motifs are phosphorylated, which facilitates the interaction with host signaling proteins. In this review, we will summarize our current knowledge on the molecular functions of the different domains present in Beps and highlight examples of Bep-dependent host cell modulation

    Persistence of Bartonella spp. stealth pathogens: from subclinical infections to vasoproliferative tumor formation

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    Bartonella spp. are facultative intracellular bacteria that typically cause a long-lasting intraerythrocytic bacteremia in their mammalian reservoir hosts, thereby favoring transmission by blood-sucking arthropods. In most cases, natural reservoir host infections are subclinical and the relapsing intraerythrocytic bacteremia may last weeks, months, or even years. In this review, we will follow the infection cycle of Bartonella spp. in a reservoir host, which typically starts with an intradermal inoculation of bacteria that are superficially scratched into the skin from arthropod feces and terminates with the pathogen exit by the blood-sucking arthropod. The current knowledge of bacterial countermeasures against mammalian immune response will be presented for each critical step of the pathogenesis. The prevailing models of the still-enigmatic primary niche and the anatomical location where bacteria reside, persist, and are periodically seeded into the bloodstream to cause the typical relapsing Bartonella spp. bacteremia will also be critically discussed. The review will end up with a discussion of the ability of Bartonella spp., namely Bartonella henselae, Bartonella quintana, and Bartonella bacilliformis, to induce tumor-like vascular deformations in humans having compromised immune response such as in patients with AID

    Why Customers Value Mass-customized Products: The Importance of Process Effort and Enjoyment

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    We test our hypotheses on 186 participants designing their own scarves with an MC toolkit. After completing the process, they submitted binding bids for "their" products in Vickrey auctions. We therefore observe real buying behavior, not merely stated intentions. We find that the subjective value of a self-designed product (i.e., one's bid in the course of the auction) is indeed not only impacted by the preference fit the customer expects it to deliver, but also by (1) the process enjoyment the customer reports, (2) the interaction of preference fit and process enjoyment, and (3) the interaction of preference fit and perceived process effort. In addition to its main effect, we interpret preference fit as a moderator of the valuegenerating effect of process evaluation: In cases where the outcome of the process is perceived as positive (high preference fit), the customer also interprets process effort as a positive accomplishment, and this positive affect adds (further) value to the product. It appears that the perception of the self-design process as a good or bad experience is partly constructed on the basis of the outcome of the process. In the opposite case (low preference fit), effort creates a negative affect which further reduces the subjective value of the product. Likewise, process enjoyment is amplified by preference fit, although enjoyment also has a significant main effect, which means that regardless of the outcome, customers attribute higher value to a self-designed product if they enjoy the process. The importance of the self-design process found in this study bears clear relevance for companies which offer or plan to offer MC systems. It is not sufficient to design MC toolkits in such a way that they allow customers to design products according to their preferences. The affect caused by this process is also highly important. Toolkits should therefore stimulate positive affective reactions and at the same time keep negative affect to a minimum. (authors' abstract

    New perspectives into bacterial DNA transfer to human cells

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    The type IV secretion system (T4SS) VirB/D4 of the facultative intracellular pathogen Bartonella henselae is known to translocate bacterial effector proteins into human cells. Two recent reports on DNA transfer into human cells have demonstrated the versatility of this bacterial secretion system for macromolecular substrate transfer. Moreover, these findings have opened the possibility for developing new tools for DNA delivery into specific human cell types. DNA can be introduced into these cells covalently attached to a site-specific integrase with potential target sequences in the human genome. This novel DNA delivery system is discussed in the context of existing methods for genetic modification of human cells

    По поводу новейших постановлений о призрении прокаженных в России

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