1,141 research outputs found
Trends in antibacterial resistance among Streptococcus pneumoniae isolated in the USA: update from PROTEKT US Years 1–4
© 2008 Jenkins et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
Fusing Quantitative Requirements Analysis with Model-based Systems Engineering
A vision is presented for fusing quantitative
requirements analysis with model-based systems
engineering. This vision draws upon and combines
emergent themes in the engineering milieu.
“Requirements engineering” provides means to
explicitly represent requirements (both functional and
non-functional) as constraints and preferences on
acceptable solutions, and emphasizes early-lifecycle
review, analysis and verification of design and
development plans. “Design by shopping” emphasizes
revealing the space of options available from which to
choose (without presuming that all selection criteria
have previously been elicited), and provides means to
make understandable the range of choices and their
ramifications. “Model-based engineering” emphasizes
the goal of utilizing a formal representation of all
aspects of system design, from development through
operations, and provides powerful tool suites that
support the practical application of these principles.
A first step prototype towards this vision is
described, embodying the key capabilities.
Illustrations, implications, further challenges and
opportunities are outlined
Effects of Prior Acute Exercise on Circulating Cytokine Concentration Responses to a High-fat Meal
High-fat meal consumption alters the circulating cytokine profile and contributes to cardiometabolic diseases. A prior bout of exercise can ameliorate the triglyceride response to a high-fat meal, but the interactive effects of exercise and high-fat meals on cytokines that mediate cardiometabolic risk are not fully understood. We investigated the effects of prior exercise on the responses of circulating tumor necrosis factor-a (TNF-a), interleukin-6 (IL-6), IL-8, leptin, retinol-binding protein 4 (RBP4), vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), placental growth factor (PlGF), and soluble fms-like tyrosine kinase-1 (sFlt-1) to a high-fat meal. Ten healthy men were studied before and 4 h after ingestion of a high-fat meal either with or without ~50 min of endurance exercise at 70% of VO2 max on the preceding day. In response to the high-fat meal, lower leptin and higher VEGF, bFGF, IL-6, and IL-8 concentrations were evident (P \u3c 0.05 for all). There was no effect of the high-fat meal on PlGF, TNF-a, or RBP4 concentrations. We found lower leptin concentrations with prior exercise (P \u3c 0.05) and interactive effects of prior exercise and the high-fat meal on sFlt-1 (P \u3c 0.05). The high-fat meal increased IL-6 by 59% without prior exercise and 218% with prior exercise (P \u3c 0.05). In conclusion, a prior bout of endurance exercise does not affect all high-fat meal–induced changes in circulating cytokines, but does affect fasting or postprandial concentrations of IL-6, leptin, and sFlt-1. These data may reflect a salutary effect of prior exercise on metabolic responses to a high-fat meal
Evaluation of interprofessional working on a therapist/nurse-led rehabilitation ward for older people in Wales
This article is a critical evaluation of a therapist/nurse-led service in a rehabilitation ward for older people (aged 65+) in an acute hospital setting in Wales, UK. The service was initiated as a means to manage increased pressures on services during the winter period between January 2016 to April 2016. It was focused on delivering comprehensive rehabilitation and robust discharge planning in order to facilitate a safe and timely return into the community. In this context, rehabilitation refers to improving patients' personal skills of independence in order for them to be discharged safely in their own home (Filmore-Elbourne and le May, 2015). Through drawing on a range of perspectives, including staff interviews and a focus group, the aim of this paper is to raise awareness of the issues that influenced the effective interprofessional working of a therapist/nurse-led rehabilitation ward for older people in an acute hospital setting. These perspectives were gathered between June and July 2016 following the closure of the ward in order to assess the perceived effectiveness of the service
Integrating Analytical Models with Descriptive System Models: Implementation of the OMG SyML Standard for the Tool-specific Case of MapleSim and MagicDraw
AbstractThe Jet Propulsion Laboratory (JPL) is investing heavily in the development of an infrastructure for building system models using the Systems Modeling Language (SysML). An essential component is a transformation apparatus that permits diverse models to be integrated independently of their nature (e.g. declarative, analytical and statistical). This paper presents one useful case: the integration of analytical models expressed using the Modelica language. Modelica is an open standard, declarative, multi-domain modeling language that allows for complex dynamic systems to be modeled. Maplesoft's MapleSim is one software tool that supports the Modelica language. The tool-neutral specification for the transformation between the languages Modelica and SysML is defined in the SysML-Modelica transformation specification (SyML) standard published by the Object Management Group (OMG). As part of the development efforts, said specification has been implemented using the Query-View- Transformation Operational (QVTO) language. During the process, several critical changes to the current SyML standard were proposed. Furthermore, a number of current limitations related to MapleSim were identified. Despite these issues, a proof-of- concept transformation was successfully implemented. In conclusion, the integration of complex simulation models conforming to the Modelica language with SysML-based system models has shown great promise and is a highly useful tool to support the decision making process in design
Individual pulmonary vein size and survival in infants with totally anomalous pulmonary venous connection
AbstractObjectives. We investigated whether mortality in totally anomalous pulmonary venous connection could be predicted from preoperative individual pulmonary vein size.Background. Some infants with this anomaly die with or without surgical repair because of stenosis of individual pulmonary veins.Methods. Individual pulmonary vein, vertical vein and pulmonary venous confluence diameters were retrospectively measured from preoperative echocardiograms in 32 infants with totally anomalous pulmonary venous connection presenting to Children's Hospital, Boston over a 1/2-year period. Data on body surface area, other cardiac anomalies, presence of initial pulmonary venous obstruction and early surgery and outcome were also recorded.Results. Of 32 patients, 6 (18.8%) died before hospital discharge, and 8 (25.0%) died subsequently. Six (75.0%) of the eight patients who died late had individual pulmonary vein stenosis at sites remote from the surgical anastomosis to the left atrium. The remaining 18 patients (56.3%) are alive at a mean follow-up period of 9.7 months. A Cox proportional hazard model revealed that small sum of individual pulmonary vein diameters (p = 0.0004), small confluence size (p = 0.02) and presence of heterotaxy syndrome (p = 0.008) were each significant univariate predictors of survival. Multivariate analysis showed that small pulmonary vein sum was a strong predictor of survival (p = 0.008), independent of the presence of heterotaxy syndrome. An analysis stratified by the presence of heterotaxy syndrome showed that the predictive effect of small pulmonary vein sum on survival was strongest in patients without heterotaxy syndrome.Conclusions. These data show that individual pulmonary vein size at diagnosis is a strong, independent predictor of survival in patients with totally anomalous pulmonary venous connection. In patients with this anomaly and small individual pulmonary veins, the anomaly may not be correctable by surgical creation of an anastomosis between the pulmonary venous confluence and the left atrium
Long-lived space observatories for astronomy and astrophysics
NASA's plan to build and launch a fleet of long-lived space observatories that include the Hubble Space Telescope (HST), the Gamma Ray Observatory (GRO), the Advanced X Ray Astrophysics Observatory (AXAF), and the Space Infrared Telescope Facility (SIRTF) are discussed. These facilities are expected to have a profound impact on the sciences of astronomy and astrophysics. The long-lived observatories will provide new insights about astronomical and astrophysical problems that range from the presence of planets orbiting nearby stars to the large-scale distribution and evolution of matter in the universe. An important concern to NASA and the scientific community is the operation and maintenance cost of the four observatories described above. The HST cost about 160 million (1986 dollars) a year to operate and maintain. If HST is operated for 20 years, the accumulated costs will be considerably more than those required for its construction. Therefore, it is essential to plan carefully for observatory operations and maintenance before a long-lived facility is constructed. The primary goal of this report is to help NASA develop guidelines for the operations and management of these future observatories so as to achieve the best possible scientific results for the resources available. Eight recommendations are given
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