133 research outputs found
The chiasmus of design: Paradoxical outcomes in the e-government reform of UK children\u27s services
Surprisingly, in addition to inexperienced computer users, also those who have used different software
applications at least to moderate extent can have feelings of anxiety with their use of computers. This
paper examines the role of training in decreasing anxiety among experienced computer users. More
specifically, the role of training is studied in relation to computer anxiety, behavioral beliefs and selfefficacy, which are the key mental constructs training may impact. 96 adult and university students,
who attended a CDL course on voluntary basis, participated in this longitudinal study. The results
suggest that training is an effective tool to decrease anxiety and promote self-efficacy even among
experienced users. In addition this study calls in the question of the relation of computer anxiety and
ease of use
Using interpretive structural modeling to uncover shared mental models in IS research
Today’s growth of the service sector as a whole has created demand for more efficient service
production. Many services require interaction between customers and service personnel,
whereas some can be automated into self-services. In this study, we focus on services, that are
neither purely human facilitated, nor purely automated, and contain uncertainty in the
production process. Based on resource centric theories of strategy and research on
uncertainties in service production, we introduce a research framework to evaluate efficient
solutions for service production. Our research framework looks at environmental and
informational uncertainties, and how an organization can adapt to these by utilizing technology
or skilled labour. Illustrated with a case company, we show how mobile information systems
can be used to manage service production related uncertainties, which are also typically
barriers to standardization. The case study demonstrates how informational uncertainty could
be more easily controlled using the new system. The job satisfaction of the workers was
increased and their turnover and training time was decreased. Additionally, customer
complaints were reduced and invoicing became more efficient. These enabled the company to
enhance the efficiency of the service production processes further, moving closer to
standardizing and automating the service production process within an uncertain environment
Managing uncertainty in service production with mobile systems - Case waste management company
Consumers’ product evaluation, choice, and use are driven by both utilitarian and hedonic
considerations. Digital games, that are typically considered to be a homogenous product
category, are often claimed to be high on hedonic value. However, there is a multitude of digital
games genres available. Differences in their appeal, gameplay, and purpose in practice indicate
that digital games vary significantly in their proposed outcome.
In this research paper, we present results from an observational survey study in which digital
games were investigated at subcategory level. We found differences in weights consumers place
on hedonic and utilitarian value at the product subcategory level, and also observed differences
between evaluations of experienced and inexperienced consumers. The results indicate that
subcategories act as a more assuring source of information than the general product category of
digital games. Furthermore, higher gaming experience may lead to more optimistic evaluation on
subcategories.
Rather than grouping digital games into one category and treating them all as hedonic products,
they should be discussed at their specific subcategory level, by researchers and practitioners,
alike
Lysophosphatidylcholine in phospholipase A(2)-modified LDL triggers secretion of angiopoietin 2
Background and aims: Secretory phospholipase A(2) (PLA(2)) hydrolyzes LDL phospholipids generating modified LDL particles (PLA(2)-LDL) with increased atherogenic properties. Exocytosis of Weibel-Palade bodies (WPB) releases angiopoietin 2 (Ang2) and externalizes P-selectin, which both play important roles in vascular inflammation. Here, we investigated the effects of PLA(2)-LDL on exocytosis of WPBs. Methods: Human coronary artery endothelial cells (HCAECs) were stimulated with PLA(2)-LDL, and its uptake and effect on Ang2 release, leukocyte adhesion, and intracellular calcium levels were measured. The effects of PLA(2)-LDL on Ang2 release and WPB exocytosis were measured in and ex vivo in mice. Results: Exposure of HCAECs to PLA(2)-LDL triggered Ang2 secretion and promoted leukocyte-HCAEC interaction. Lysophosphatidylcholine was identified as a critical component of PLA(2)-LDL regulating the WPB exocytosis, which was mediated by cell-surface proteoglycans, phospholipase C, intracellular calcium, and cytoskeletal remodeling. PLA(2)-LDL also induced murine endothelial WPB exocytosis in blood vessels in and ex vivo, as evidenced by secretion of Ang2 in vivo, P-selectin translocation to plasma membrane in intact endothelial cells in thoracic artery and tracheal vessels, and reduced Ang2 staining in tracheal endothelial cells. Finally, in contrast to normal human coronary arteries, in which Ang2 was present only in the endothelial layer, at sites of advanced atherosclerotic lesions, Ang2 was detected also in the intima, media, and adventitia. Conclusions: Our studies reveal PLA(2)-LDL as a potent agonist of endothelial WPB exocytosis, resulting in increased secretion of Ang2 and translocation of P-selectin. The results provide mechanistic insight into PLA(2)-LDL-dependent promotion of vascular inflammation and atherosclerosis.Peer reviewe
Carboxyl-Terminal Cleavage of Apolipoprotein A-I by Human Mast Cell Chymase Impairs Its Anti-Inflammatory Properties
Objective Apolipoprotein A-I (apoA-I) has been shown to possess several atheroprotective functions, including inhibition of inflammation. Protease-secreting activated mast cells reside in human atherosclerotic lesions. Here we investigated the effects of the neutral proteases released by activated mast cells on the anti-inflammatory properties of apoA-I. Approach and Results Activation of human mast cells triggered the release of granule-associated proteases chymase, tryptase, cathepsin G, carboxypeptidase A, and granzyme B. Among them, chymase cleaved apoA-I with the greatest efficiency and generated C-terminally truncated apoA-I, which failed to bind with high affinity to human coronary artery endothelial cells. In tumor necrosis factor--activated human coronary artery endothelial cells, the chymase-cleaved apoA-I was unable to suppress nuclear factor-B-dependent upregulation of vascular cell adhesion molecule-1 (VCAM-1) and to block THP-1 cells from adhering to and transmigrating across the human coronary artery endothelial cells. Chymase-cleaved apoA-I also had an impaired ability to downregulate the expression of tumor necrosis factor-, interleukin-1, interleukin-6, and interleukin-8 in lipopolysaccharide-activated GM-CSF (granulocyte-macrophage colony-stimulating factor)- and M-CSF (macrophage colony-stimulating factor)-differentiated human macrophage foam cells and to inhibit reactive oxygen species formation in PMA (phorbol 12-myristate 13-acetate)-activated human neutrophils. Importantly, chymase-cleaved apoA-I showed reduced ability to inhibit lipopolysaccharide-induced inflammation in vivo in mice. Treatment with chymase blocked the ability of the apoA-I mimetic peptide L-4F, but not of the protease-resistant D-4F, to inhibit proinflammatory gene expression in activated human coronary artery endothelial cells and macrophage foam cells and to prevent reactive oxygen species formation in activated neutrophils. Conclusions The findings identify C-terminal cleavage of apoA-I by human mast cell chymase as a novel mechanism leading to loss of its anti-inflammatory functions. When targeting inflamed protease-rich atherosclerotic lesions with apoA-I, infusions of protease-resistant apoA-I might be the appropriate approach.Peer reviewe
Vasculoprotective properties of plasma lipoproteins from brown bears (Ursus arctos)
Plasma cholesterol and triglyceride (TG) levels are twice as high in hibernating brown bears (Ursus arctos) than healthy humans. Yet, bears display no signs of early stage atherosclerosis development when adult. To explore this apparent paradox, we analyzed plasma lipoproteins from the same 10 bears in winter (hibernation) and summer using size exclusion chromatography, ultracentrifugation, and electrophoresis. LDL binding to arterial proteoglycans (PGs) and plasma cholesterol efflux capacity (CEC) were also evaluated. The data collected and analyzed from bears were also compared with those from healthy humans. In bears, the cholesterol ester, unesterified cholesterol, TG, and phospholipid contents of VLDL and LDL were higher in winter than in summer. The percentage lipid composition of LDL differed between bears and humans but did not change seasonally in bears. Bear LDL was larger, richer in TGs, showed prebeta electrophoretic mobility, and had 5-10 times lower binding to arterial PGs than human LDL. Finally, plasma CEC was higher in bears than in humans, especially the HDL fraction when mediated by ABCA1. These results suggest that in brown bears the absence of early atherogenesis is likely associated with a lower affinity of LDL for arterial PGs and an elevated CEC of bear plasma
Streptococcus pneumoniae pneumolysin and neuraminidase A convert high-density lipoproteins into pro-atherogenic particles
High-density lipoproteins (HDLs) are a group of different subpopulations of sialylated particles that have an essential role in the reverse cholesterol transport (RCT) pathway. Importantly, changes in the protein and lipid composition of HDLsmay lead to the formation of particles with reduced atheroprotective properties. Here, we show that Streptococcus pneumoniae pneumolysin (PLY) and neuraminidase A (NanA) impair HDL function by causing chemical and structural modifications of HDLs. The proteomic, lipidomic, cellular, and biochemical analysis revealed that PLY and NanA induce significant changes in sialic acid, protein, and lipid compositions of HDL. The modified HDL particles have reduced cholesterol acceptor potential from activated macrophages, elevated levels of malondialdehyde adducts, and show significantly increased complement activating capacity. These results suggest that accumulation of these modified HDL particles in the arterial intima may present a trigger for complement activation, inflammatory response, and thereby promote atherogenic disease progression.Peer reviewe
Progress in information technology and tourism management: 20 years on and 10 years after the Internet—The state of eTourism research
This paper reviews the published articles on eTourism in the past 20 years. Using a wide variety of sources, mainly in the tourism literature, this paper comprehensively reviews and analyzes prior studies in the context of Internet applications to Tourism. The paper also projects future developments in eTourism and demonstrates critical changes that will influence the tourism industry structure. A major contribution of this paper is its overview of the research and development efforts that have been endeavoured in the field, and the challenges that tourism researchers are, and will be, facing
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