2,251 research outputs found

    Elevated PAI-1 is associated with poor clinical outcomes in pediatric patients with acute lung injury.

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    PurposeDeposition of fibrin in the alveolar space is a hallmark of acute lung injury (ALI). Plasminogen activator inhibitor-1 (PAI-1) is an antifibrinolytic agent that is activated during inflammation. Increased plasma and pulmonary edema fluid levels of PAI-1 are associated with increased mortality in adults with ALI. This relationship has not been examined in children. The objective of this study was to test whether increased plasma PAI-1 levels are associated with worse clinical outcomes in pediatric patients with ALI.Design/methodsWe measured plasma PAI-1 levels on the first day of ALI among 94 pediatric patients enrolled in two separate prospective, multicenter investigations and followed them for clinical outcomes. All patients met American European Consensus Conference criteria for ALI.ResultsA total of 94 patients were included. The median age was 3.2 years (range 16 days-18 years), the PaO(2)/F(i)O(2) was 141 +/- 72 (mean +/- SD), and overall mortality was 14/94 (15%). PAI-1 levels were significantly higher in nonsurvivors compared to survivors (P < 0.01). The adjusted odds of mortality doubled for every log increase in the level of plasma PAI-1 after adjustment for age and severity of illness.ConclusionsHigher PAI-1 levels are associated with increased mortality and fewer ventilator-free days among pediatric patients with ALI. These findings suggest that impaired fibrinolysis may play a role in the pathogenesis of ALI in pediatric patients and suggest that PAI-1 may serve as a useful biomarker of prognosis in patients with ALI

    An evaluation of the goal-oriented approaches for modelling strategic alignment concept

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    Several frameworks have been proposed in Requirements Engineering (RE) discipline that use goal-oriented approach to model the concept of strategic alignment. Understanding the concept of strategic alignment from the perspective of Management Information Systems (MIS) discipline and evaluating goal-oriented approaches in the context of strategic alignment appear to be the fundamental weakness in the RE frameworks that claim to model strategic alignment. In this research we developed a list of constructs by analysing the concept of strategic alignment embedded in strategy map which is one of the widely used frameworks to develop strategic alignment in MIS discipline. In this regard we analysed details of a case study conducted to develop strategic alignment. Against the identified list of constructs we evaluated five well-known goal-oriented approaches and presented their level of effectiveness to model the concept of strategic alignment. © 2011 IEEE

    A Review and comparison of service E-Contract Architecture Metamodels

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    © Springer International Publishing Switzerland 2015. An adaptive service e-contract is an electronic agreement which is required to enable adaptive or agile service sourcing and pro- visioning. There are a number of e-contract metamodels that can be used to create a context specific adaptive service e-contract. The chal- lenge is which one to choose and adopt for adaptive services. This paper presents a review and comparison of well-known e-contract metamod- els using the architecture theory. The architecture theory allows the analysis of the e-contract metamodels using a three-dimension analyt- ical lens: structure, behavior and technology. The results of this paper highlight the metamodels structural, behavioral and technological differ- ences and similarities. This paper will help researchers and practitioners to observe the existing e-contract metamodels are appropriate to the adaptive services or if thwhetherere is a need to merge and integrate the concepts of these metamodels to propose a new unifying adaptive service e-contract metamodel. This paper is limited to the number of compared metamodels

    Noiseless nonreciprocity in a parametric active device

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    Nonreciprocal devices such as circulators and isolators belong to an important class of microwave components employed in applications like the measurement of mesoscopic circuits at cryogenic temperatures. The measurement protocols usually involve an amplification chain which relies on circulators to separate input and output channels and to suppress backaction from different stages on the sample under test. In these devices the usual reciprocal symmetry of circuits is broken by the phenomenon of Faraday rotation based on magnetic materials and fields. However, magnets are averse to on-chip integration, and magnetic fields are deleterious to delicate superconducting devices. Here we present a new proposal combining two stages of parametric modulation emulating the action of a circulator. It is devoid of magnetic components and suitable for on-chip integration. As the design is free of any dissipative elements and based on reversible operation, the device operates noiselessly, giving it an important advantage over other nonreciprocal active devices for quantum information processing applications.Comment: 17 pages, 4 figures + 12 pages Supplementary Informatio

    Preferential Paths of Air-water Two-phase Flow in Porous Structures with Special Consideration of Channel Thickness Effects.

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    Accurate understanding and predicting the flow paths of immiscible two-phase flow in rocky porous structures are of critical importance for the evaluation of oil or gas recovery and prediction of rock slides caused by gas-liquid flow. A 2D phase field model was established for compressible air-water two-phase flow in heterogenous porous structures. The dynamic characteristics of air-water two-phase interface and preferential paths in porous structures were simulated. The factors affecting the path selection of two-phase flow in porous structures were analyzed. Transparent physical models of complex porous structures were prepared using 3D printing technology. Tracer dye was used to visually observe the flow characteristics and path selection in air-water two-phase displacement experiments. The experimental observations agree with the numerical results used to validate the accuracy of phase field model. The effects of channel thickness on the air-water two-phase flow behavior and paths in porous structures were also analyzed. The results indicate that thick channels can induce secondary air flow paths due to the increase in flow resistance; consequently, the flow distribution is different from that in narrow channels. This study provides a new reference for quantitatively analyzing multi-phase flow and predicting the preferential paths of immiscible fluids in porous structures

    Gene network effects on brain microstructure and intellectual performance identified in 472 twins

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    A major challenge in neuroscience is finding which genes affect brain integrity, connectivity, and intellectual function. Discovering influential genes holds vast promise for neuroscience, but typical genome-wide searches assess approximately one million genetic variants one-by-one, leading to intractable false positive rates, even with vast samples of subjects. Even more intractable is the question of which genes interact and how they work together to affect brain connectivity. Here, we report a novel approach that discovers which genes contribute to brain wiring and fiber integrity at all pairs of points in a brain scan. We studied genetic correlations between thousands of points in human brain images from 472 twins and their nontwin siblings (mean age: 23.7 ± 2.1 SD years; 193 male/279 female). We combined clustering with genome-wide scanning to find brain systems with common genetic determination. We then filtered the image in a new way to boost power to find causal genes. Using network analysis, we found a network of genes that affect brain wiring in healthy young adults. Our new strategy makes it computationally more tractable to discover genes that affect brain integrity. The gene network showed small-world and scale-free topologies, suggesting efficiency in genetic interactions and resilience to network disruption. Genetic variants at hubs of the network influence intellectual performance by modulating associations between performance intelligence quotient and the integrity of major white matter tracts, such as the callosal genu and splenium, cingulum, optic radiations, and the superior longitudinal fasciculus

    Cardiac afferent activity modulates the expression of racial stereotypes

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    Negative racial stereotypes tend to associate Black people with threat. This often leads to the misidentification of harmless objects as weapons held by a Black individual. Yet, little is known about how bodily states impact the expression of racial stereotyping. By tapping into the phasic activation of arterial baroreceptors, known to be associated with changes in the neural processing of fearful stimuli, we show activation of race-threat stereotypes synchronized with the cardiovascular cycle. Across two established tasks, stimuli depicting Black or White individuals were presented to coincide with either the cardiac systole or diastole. Results show increased race-driven misidentification of weapons during systole, when baroreceptor afferent firing is maximal, relative to diastole. Importantly, a third study examining the positive Black-athletic stereotypical association fails to demonstrate similar modulations by cardiac cycle. We identify a body–brain interaction wherein interoceptive cues can modulate threat appraisal and racially biased behaviour in context-dependent ways
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