575 research outputs found

    A high-level semiotic trust agent scoring model for collaborative virtual organisations

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    In this paper, we describe how a semiotic ladder, together with a supportive trust agent, can be used to address “soft” trust issues in the context of collaborative Virtual Organisations (VO). The intention is to offer all parties better support for trust (as reputation) management including the reduction of risk and improved reliability of VO e-services. The semiotic ladder is intended to support the VO e-service lifecycle through the articulation of e-trust at various levels of system abstraction, including trust as measurable confidence. At the social level, reputation and reliability measures of e-trust are the relevant dimensions as regards choice of VO partner and are also relevant to the negotiation of service level agreements between the VO partners. By contrast, at the lower levels of the trust ladder, e-trust measures typically address the degree to which secure sign on and message level security conforms to various tangible technological security protocols. The novel trust agent provides the e-service consumer with an objective measure of the trustworthiness of the e-service at run-time, just prior to its actual consumption. Specifically, VO e-service consumer confidence level is informed, by leveraging third party objective evidence. This evidence comprises a set of Corporate Governance (CG) scores. These scores are used as a trust proxy for the "real" owner of the VO. There are also inherent limitations associated with the use of CG scores. These are duly acknowledged

    Social Media Marketing: How Social Media Has Impacted the Gender Differences That Exist Amongst Sports Fans, and its Effect of Marketers

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    This professional research study accessed the current relationship between season ticket holders of Marquette University men’s college basketball team and usage of social media. A survey was created based on a modification of the Sport Spectator Identification Scale (or SSIS) as well as the Sport Fandom Questionnaire (or SFQ), and included specific questions related to the individual’s demographics, social media usage, and experience attending collegiate basketball games. Despite the fact that females are continuing to have an increasing presence in the vast world of sports, marketers and organizations continue to place a strong focus on the needs, interests, and desires of male sports fans. Additionally, the advancement of social media while beneficial for marketers has created a clouded and convoluted world in which consumers and fans receive thousands of messages on any given day. Thus, it is essential that sports marketers understand the connection that social media has to its fans and consumers, as well as the growing role and presence of females in sport. Questions that were asked prior to the study were: How has the advancement of social media impacted gender differences that exist between sports fans today? What is the relationship between gender differences that exist amongst sports fans in relation to social media usage, preferences, and trends? Collected data and analysis of the results using a t-test reaffirmed previous findings in regards to consumption of sport, identification with a specific team, and social media usage. Males continue to rank higher in terms of consuming sport and identifying with a particular team, and that a connection does exist between fandom and identification. Females continue to use social media more, but males use it more for sports related purposes. There also appears to be a connection between sports and social media for males and females. Males prefer to consume sports and social media to express their opinions as well as for observational and informational reasons. In comparison, females tend to consume sport, identify with a team, and access social media sites primarily to communicate with friends and family. There has been a gap between previous research studies on gender differences of sports fans in relation to social media users, thus, findings from this study will be beneficial for marketers and organizations that operate within the sports industry. In particular, findings will have an impact on how these professionals and organizations customize their marketing campaigns and successfully incorporate an integrated social media marketing message and campaign that better reaches their targeted consumer base and fan base

    Decision trees in epidemiological research

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    Background: In many studies, it is of interest to identify population subgroups that are relatively homogeneous with respect to an outcome. The nature of these subgroups can provide insight into effect mechanisms and suggest targets for tailored interventions. However, identifying relevant subgroups can be challenging with standard statistical methods. Main text: We review the literature on decision trees, a family of techniques for partitioning the population, on the basis of covariates, into distinct subgroups who share similar values of an outcome variable. We compare two decision tree methods, the popular Classification and Regression tree (CART) technique and the newer Conditional Inference tree (CTree) technique, assessing their performance in a simulation study and using data from the Box Lunch Study, a randomized controlled trial of a portion size intervention. Both CART and CTree identify homogeneous population subgroups and offer improved prediction accuracy relative to regression-based approaches when subgroups are truly present in the data. An important distinction between CART and CTree is that the latter uses a formal statistical hypothesis testing framework in building decision trees, which simplifies the process of identifying and interpreting the final tree model. We also introduce a novel way to visualize the subgroups defined by decision trees. Our novel graphical visualization provides a more scientifically meaningful characterization of the subgroups identified by decision trees. Conclusions: Decision trees are a useful tool for identifying homogeneous subgroups defined by combinations of individual characteristics. While all decision tree techniques generate subgroups, we advocate the use of the newer CTree technique due to its simplicity and ease of interpretation

    Meis1 specifies positional information in the retina and tectum to organize the zebrafish visual system

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    <p>Abstract</p> <p>Background</p> <p>During visual system development, multiple signalling pathways cooperate to specify axial polarity within the retina and optic tectum. This information is required for the topographic mapping of retinal ganglion cell axons on the tectum. Meis1 is a TALE-class homeodomain transcription factor known to specify anterior-posterior identity in the hindbrain, but its role in visual system patterning has not been investigated.</p> <p>Results</p> <p><it>meis1 </it>is expressed in both the presumptive retina and tectum. An analysis of retinal patterning reveals that Meis1 is required to correctly specify both dorsal-ventral and nasal-temporal identity in the zebrafish retina. Meis1-knockdown results in a loss of <it>smad1 </it>expression and an upregulation in <it>follistatin </it>expression, thereby causing lower levels of Bmp signalling and a partial ventralization of the retina. Additionally, Meis1-deficient embryos exhibit ectopic Fgf signalling in the developing retina and a corresponding loss of temporal identity. Meis1 also positively regulates <it>ephrin </it>gene expression in the tectum. Consistent with these patterning phenotypes, a knockdown of Meis1 ultimately results in retinotectal mapping defects.</p> <p>Conclusions</p> <p>In this work we describe a novel role for Meis1 in regulating Bmp signalling and in specifying temporal identity in the retina. By patterning both the retina and tectum, Meis1 plays an important role in establishing the retinotectal map and organizing the visual system.</p

    Art From the Abyss

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    This document is written in support of the thesis exhibition, Art from the Abyss, which represents and supports the idea of art-making as a catharsis. Through these works, negative emotions are identified, named, and given an image. Frightening emotional issues become visual caricatures, placed within a non-threatening context, where they can be understood. Understanding creates tolerance, and lessens fear and distrust. The metaphorical abyss is not just a repository for potential evil, but an important source of positive, creative energy.  M.F.A

    Thoracoscopic Thoracic Duct Ligation for Persistent Cervical Chyle Leak: Utility of Immediate Pathologic Confirmation

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    ObjectiveChylous fistulas can occur after neck surgery. Both nonoperative measures and direct fistula ligation may lead to fistula resolution. However, a refractory fistula requires upstream thoracic duct ligation. This can be accomplished minimally invasively. Success depends on lymphatic flow interruption where the duct enters the thorax. We report on the utility of frozen section confirmation in achieving this goal.MethodsPersistent chylous fistulas occurred in 2 patients after left cervical operations. In the first patient, attempted direct fistula ligation and sclerosant application failed. Fasting, parenteral nutrition, and somatostatin-analog provided no benefit. For the second patient, nonoperative treatment was also ineffective. Prior radiation therapy and multiple cervical operations militated against attempted direct fistula ligation. Both patients underwent thoracoscopic thoracic duct interruption.ResultsIn both cases, a duct candidate was identified between the aorta and azygos vein. Frozen section analysis of tissue resected between endoclips verified it as thoracic duct. Fistula resolution ensued promptly in both instances.ConclusionsThis report lends further credence to the efficacy of minimally invasive thoracic duct ligation in treating postoperative cervical chylous fistulas. Frozen section confirmation of thoracic duct tissue is useful. It allows one facile with thoracoscopy, but less familiar with thoracic duct ligation, to confidently terminate the operation

    Liver carnitine metabolism after partial hepatectomy in the rat Effects of nutritional status and inhibition of carnitine palmitoyltransferase

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    AbstractThis study examined the effects of partial hepatectony on hepatic carnitine and acylcarnitine concentrations in fed or 24 h-starved partially hepatectonized (PH) or sham-operated (SO) rats at 1 or 4 days after surgery. The ratio of free to esterified carnitine was low in fed PH rats at day 1 : the low ratio was increased to the SO value when mitochondrial fat oxidation was inhibited by 2-tetradecylglycidate. Starvation (24 h) increased plasma [non-esterified fatty acid] in PH or SO rats, the increases being greater at day 1 than at day 4. Hepatic [long-chain acylcarnitine] were also increased. These latter increases were a consequence of increased mitochondrial fat oxidation since they were not observed in PH or SO rats treated with 2-tetradecylglycidate. Whereas the starvation-induced increase in long-chain acylcarnitine was associated with increased [ketone body] in livers of SO rats at both day 1 and day 4 after surgery, [ketone body] was inappropriately low for the steady-state long-chain [acylcarnitine] in livers of PH rats at the first post-operative day. This was not a consequence of a decrease in [total carnitine] in the liver. The results are discussed with reference to the role of the liver in determining the relative proportions of the fat fuels available for extrahepatic tissues and the effects of liver cell proliferation on hepatic triacylclycerol metabolism

    On the Substitution of Identicals in Counterfactual Reasoning

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    It is widely held that counterfactuals, unlike attitude ascriptions, preserve the referential transparency of their constituents, i.e., that counterfactuals validate the substitution of identicals when their constituents do. The only putative counterexamples in the literature come from counterpossibles, i.e., counterfactuals with impossible antecedents. Advocates of counterpossibilism, i.e., the view that counterpossibles are not all vacuous, argue that counterpossibles can generate referential opacity. But in order to explain why most substitution inferences into counterfactuals seem valid, counterpossibilists also often maintain that counterfactuals with possible antecedents are transparency‐preserving. I argue that if counterpossibles can generate opacity, then so can ordinary counterfactuals with possible antecedents. Utilizing an analogy between counterfactuals and attitude ascriptions, I provide a counterpossibilist‐friendly explanation for the apparent validity of substitution inferences into counterfactuals. I conclude by suggesting that the debate over counterpossibles is closely tied to questions concerning the extent to which counterfactuals are more like attitude ascriptions and epistemic operators than previously recognized

    A Proposed Astronomy Learning Progression For Remote Telescope Observation

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    Providing meaningful telescope observing experiences for students who are deeply urban or distantly rural place-bound—or even daylight time-bound—has consistently presented a formidable challenge for astronomy educators.  For nearly 2 decades, the Internet has promised unfettered access for large numbers of students to conduct remote telescope observing, but it has only been in recent years that the technology has become readily available.  Now that this once fanciful possibility is becoming a reality, astronomy education researchers need a guiding theory on which to develop learning experiences.  As one departure point, we propose a potential learning progression anchored on one end with recognizing that stars visible at night have describable locations and predictable motions, and anchored at the other with distant robotic telescopes can be programmed to record specific astronomical data for later analysis

    Toxoplasma co-infection prevents Th2 differentiation and leads to a helminth- specific Th1 response

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    Nematode infections, in particular gastrointestinal nematodes, are widespread and co-infections with other parasites and pathogens are frequently encountered in humans and animals. To decipher the immunological effects of a widespread protozoan infection on the anti-helminth immune response we studied a co-infection with the enteric nematode Heligmosomoides polygyrus in mice previously infected with Toxoplasma gondii. Protective immune responses against nematodes are dependent on parasite-specific Th2 responses associated with IL-4, IL-5, IL-13, IgE, and IgG1 antibodies. In contrast, Toxoplasma gondii infection elicits a strong and protective Th1 immune response characterized by IFN-γ, IL-12, and IgG2a antibodies. Co-infected animals displayed significantly higher worm fecundity although worm burden remained unchanged. In line with this, the Th2 response to H. polygyrus in co-infected animals showed a profound reduction of IL-4, IL-5, IL-13, and GATA-3 expressing T cells. Co-infection also resulted in the lack of eosinophilia and reduced expression of the Th2 effector molecule RELM-β in intestinal tissue. In contrast, the Th1 response to the protozoan parasite was not diminished and parasitemia of T. gondii was unaffected by concurrent helminth infection. Importantly, H. polygyrus specific restimulation of splenocytes revealed H. polygyrus-reactive CD4+ T cells that produce a significant amount of IFN-γ in co-infected animals. This was not observed in animals infected with the nematode alone. Increased levels of H. polygyrus-specific IgG2a antibodies in co-infected mice mirrored this finding. This study suggests that polarization rather than priming of naive CD4+ T cells is disturbed in mice previously infected with T. gondii. In conclusion, a previous T. gondii infection limits a helminth-specific Th2 immune response while promoting a shift toward a Th1-type immune response
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