517 research outputs found

    Analysis of Media Agenda-Setting Effects on Consumer Confidence in the Safety of the U.S. Food System

    Get PDF
    Results from continuous tracking of consumer confidence and media coverage of food safety events over a 67 week period between May 2008 and August 2009 are reported. An ordered probit model is used to test the hypothesis that media coverage of food safety events affects consumer confidence in the safety of the U.S. food system. The results show that media coverage significantly and negatively affected consumer confidence in the safety of nation’s food supply during the sample period. Socioeconomic and demographic factors such as geographic region, use of media source, household size, age, ethnicity, education, and gender also had significant affects on consumer confidence in the safety of United States food supply.Food Safety, Consumer Confidence, Mass media, ordered probit, Food Consumption/Nutrition/Food Safety,

    Consumer Confidence in the Food System, Media Coverage and Stock Prices of Food Companies: A Regression Analysis

    Get PDF
    A series of recent and serious food safety incidents have generated a national debate over the significant costs that they impose on various stakeholders - consumers, industry, or the government. This paper examines the impact of media coverage of food safety and defense issues on consumer confidence in food safety, and measures the response of stock prices of food companies to changes in consumer confidence. Results show that, increases in media coverage have a negative impact on consumer confidence, and that decreases in the levels of consumer confidence on food safety have a negative impact on stock prices of food companies, in particular for the larger firms. These findings confirm that the financial performance of food the industry is negatively affected by category-specific food safety events, and the effects of media coverage on consumer confidence in the safety of the food system.Agribusiness, Food Consumption/Nutrition/Food Safety,

    The views of children and young people on the use of silk garments for the treatment of eczema: a nested qualitative study within the CLOTHES randomised controlled trial

    Get PDF
    Background: Many children suffer with skin diseases, but to date, most dermatological research has been done ‘on’ rather than ‘with’ children; in this study we actively sought the experiences of children and young people. Atopic eczema (AE) is a chronic, itchy, inflammatory skin condition that affects around 20% of children and can impact on health and wellbeing for children and their families. The role of specialist clothing in the management of AE is poorly understood. Objectives: The aim of this study, which was nested in a randomised controlled trial was to qualitatively examine child participants’ experiences of using silk garments for the treatment of AE. Methods: Eighteen children aged 5-15, who took part in the CLOTHES trial, participated in age-appropriate individual interviews or focus groups. Results: Thematic analysis generated 4 themes directly related to the garments: i) expectations of the garments; ii) wearing the silk garments; iii) did they help? and iv) thoughts about the garments. The conclusions from this nested qualitative study are that: there was some limited improvement in eczema for some children but that the hoped for ‘miracle cure’ did not transpire. A mixed picture of knowledge, beliefs and experiences of using the silk garments emerged. Conclusion: Engaging children in the evaluation of the garments provided first hand nuanced insights that enhanced understanding of the CLOTHES study as a whole. This nested study demonstrates that children can and indeed want to be engaged in dermatological research in meaningful ways that add to our understanding of treatment options

    The Long-Term Future of Extragalactic Astronomy

    Get PDF
    If the current energy density of the universe is indeed dominated by a cosmological constant, then high-redshift sources will remain visible to us only until they reach some finite age in their rest-frame. The radiation emitted beyond that age will never reach us due to the acceleration of the cosmic expansion rate, and so we will never know what these sources look like as they become older. As a source image freezes on a particular time frame along its evolution, its luminosity distance and redshift continue to increase exponentially with observation time. The higher the current redshift of a source is, the younger it will appear as it fades out of sight. For the popular set of cosmological parameters, I show that a source at a redshift z=5-10 will only be visible up to an age of 4-6 billion years. Arguments relating the properties of high-redshift sources to present-day counterparts will remain indirect even if we continue to monitor these sources for an infinite amount of time. These sources will not be visible to us when they reach the current age of the universe.Comment: Phys. Rev. D, in press (2001

    Tight-binding study of interface states in semiconductor heterojunctions

    Full text link
    Localized interface states in abrupt semiconductor heterojunctions are studied within a tight-binding model. The intention is to provide a microscopic foundation for the results of similar studies which were based upon the two-band model within the envelope function approximation. In a two-dimensional description, the tight-binding Hamiltonian is constructed such that the Dirac-like bulk spectrum of the two-band model is recovered in the continuum limit. Localized states in heterojunctions are shown to occur under conditions equivalent to those of the two-band model. In particular, shallow interface states are identified in non-inverted junctions with intersecting bulk dispersion curves. As a specific example, the GaSb-AlSb heterojunction is considered. The matching conditions of the envelope function approximation are analyzed within the tight-binding description.Comment: RevTeX, 11 pages, 3 figures, to appear in Phys. Rev.

    Weak antiferromagnetism due to Dzyaloshinskii-Moriya interaction in Ba3_3Cu2_2O4_4Cl2_2

    Full text link
    The antiferromagnetic insulating cuprate Ba3_3Cu2_2O4_4Cl2_2 contains folded CuO2_2 chains with four magnetic copper ions (S=1/2S=1/2) per unit cell. An underlying multiorbital Hubbard model is formulated and the superexchange theory is developed to derive an effective spin Hamiltonian for this cuprate. The resulting spin Hamiltonian involves a Dzyaloshinskii-Moriya term and a more weak symmetric anisotropic exchange term besides the isotropic exchange interaction. The corresponding Dzyaloshinskii-Moriya vectors of each magnetic Cu-Cu bond in the chain reveal a well defined spatial order. Both, the superexchange theory and the complementary group theoretical consideration, lead to the same conclusion on the character of this order. The analysis of the ground-state magnetic properties of the derived model leads to the prediction of an additional noncollinear modulation of the antiferromagnetic structure. This weak antiferromagnetism is restricted to one of the Cu sublattices.Comment: 13 pages, 1 table, 4 figure

    Immune cells control skin lymphatic electrolyte homeostasis and blood pressure

    Get PDF
    The skin interstitium sequesters excess Na+ and Cl- in salt-sensitive hypertension. Mononuclear phagocyte system (MPS) cells are recruited to the skin, sense the hypertonic electrolyte accumulation in skin, and activate the tonicity-responsive enhancer-binding protein (TONEBP, also known as NFAT5) to initiate expression and secretion of VEGFC, which enhances electrolyte clearance via cutaneous lymph vessels and increases eNOS expression in blood vessels. It is unclear whether this local MPS response to osmotic stress is important to systemic blood pressure control. Herein, we show that deletion of TonEBP in mouse MPS cells prevents the VEGFC response to a high-salt diet (HSD) and increases blood pressure. Additionally, an antibody that blocks the lymph-endothelial VEGFC receptor, VEGFR3, selectively inhibited MPS-driven increases in cutaneous lymphatic capillary density, led to skin Cl- accumulation, and induced salt-sensitive hypertension. Mice overexpressing soluble VEGFR3 in epidermal keratinocytes exhibited hypoplastic cutaneous lymph capillaries and increased Na+, Cl-, and water retention in skin and salt-sensitive hypertension. Further, we found that HSD elevated skin osmolality above plasma levels. These results suggest that the skin contains a hypertonic interstitial fluid compartment in which MPS cells exert homeostatic and blood pressure-regulatory control by local organization of interstitial electrolyte clearance via TONEBP and VEGFC/VEGFR3-mediated modification of cutaneous lymphatic capillary function

    A Model for the Development of the Rhizobial and Arbuscular Mycorrhizal Symbioses in Legumes and Its Use to Understand the Roles of Ethylene in the Establishment of these two Symbioses

    Get PDF
    We propose a model depicting the development of nodulation and arbuscular mycorrhizae. Both processes are dissected into many steps, using Pisum sativum L. nodulation mutants as a guideline. For nodulation, we distinguish two main developmental programs, one epidermal and one cortical. Whereas Nod factors alone affect the cortical program, bacteria are required to trigger the epidermal events. We propose that the two programs of the rhizobial symbiosis evolved separately and that, over time, they came to function together. The distinction between these two programs does not exist for arbuscular mycorrhizae development despite events occurring in both root tissues. Mutations that affect both symbioses are restricted to the epidermal program. We propose here sites of action and potential roles for ethylene during the formation of the two symbioses with a specific hypothesis for nodule organogenesis. Assuming the epidermis does not make ethylene, the microsymbionts probably first encounter a regulatory level of ethylene at the epidermis–outermost cortical cell layer interface. Depending on the hormone concentrations there, infection will either progress or be blocked. In the former case, ethylene affects the cortex cytoskeleton, allowing reorganization that facilitates infection; in the latter case, ethylene acts on several enzymes that interfere with infection thread growth, causing it to abort. Throughout this review, the difficulty of generalizing the roles of ethylene is emphasized and numerous examples are given to demonstrate the diversity that exists in plants

    Group diversity and group identification:the moderating role of diversity beliefs

    Get PDF
    Research on diversity in teams and organizations has revealed ambiguous results regarding the effects of group composition on workgroup performance. The categorization—elaboration model (van Knippenberg et al., 2004) accounts for this variety and proposes two different underlying processes. On the one hand diversity may bring about intergroup bias which leads to less group identification, which in turn is followed by more conflict and decreased workgroup performance. On the other hand, the information processing approach proposes positive effects of diversity because of a more elaborate processing of information brought about by a wider pool and variety of perspectives in more diverse groups. We propose that the former process is contingent on individual team members' beliefs that diversity is good or bad for achieving the team's aims. We predict that the relationship between subjective diversity and identification is more positive in ethnically diverse project teams when group members hold beliefs that are pro-diversity. Results of two longitudinal studies involving postgraduate students working in project teams confirm this hypothesis. Analyses further reveal that group identification is positively related to students' desire to stay in their groups and to their information elaboration. Finally, we found evidence for the expected moderated mediation model with indirect effects of subjective diversity on elaboration and the desire to stay, mediated through group identification, moderated by diversity beliefs
    corecore