24 research outputs found
Modular smoothed analysis of median-of-three Quicksort
Spielman’s smoothed complexity - a hybrid between worst and average case complexity measures - relies on perturbations of input instances to determine where average-case behavior turns to worst-case. This approach simplifies the smoothed analysis and achieves greater precession in the expression of the smoothed complexity, where a recurrence equation is obtained as opposed to bounds. Moreover, the approach addresses, in this context, the formation of input instances–an open problem in smoothed complexity. In [23], we proposed a method supporting modular smoothed analysis and illustrated the method by determining the modular smoothed complexity of Quicksort. Here, we use the modular approach to calculate the median of three variant and compare these results with those in [23]
Modular smoothed analysis
Spielman’s smoothed complexity - a hybrid between worst and average case complexity measures - relies on perturbations of input instances to determine where average-case behavior turns to worst-case. The paper proposes a method supporting modular smoothed analysis. The method, involving a novel permutation model, is developed for the discrete case, focusing on randomness preserving algorithms. This approach simplifies the smoothed analysis and achieves greater precession in the expression of the smoothed complexity, where a recurrence equation is obtained as opposed to bounds. Moreover, the approach addresses, in this context, the formation of input instances–an open problem in smoothed complexity. To illustrate the method, we determine the modular smoothed complexity of Quicksort
Treatment of Gram-Negative Septic Shock with Human IgG Antibody to Escherichia coli J5: A Prospective, Double-Blind, Randomized Trial
In a randomized, double-blind, multicenter trial we compared the efficacy of a preparation of human IgG antibody to Escherichia coli 15 (J5-IVIG) with that of a standard IgG preparation (IVIG) for the treatment of gram-negative septic shock. At study entry, patients received a single intravenous dose of 200 mg/kg of body weight (maximal dose, 12 g) of either J5-IVIG or IVIG. Of the 100 patients randomized, 71 (30 receiving J5-IVIG and 41 receiving IVIG) had a documented gram-negative infection. Mortality from gram-negative septic shock was 50% (15 of 30) in J5-IVIG recipients and 49% (20 of 41) in IVIG recipients. In addition, treatment with J5-IVIG did not reduce the number of systemic complications of shock and did not delay the occurrence of death due to septic shock. Thus we conclude that 15-IVIG was not superior to IVIG in reducing mortality or in reversing gram-negative septic shoc
Prognostic Values of Tumor Necrosis Factor/Cachectin, Interleukin-l, Interferon-α, and Interferon-γ in the Serum of Patients with Septic Shock
Serum concentrations of immunoreactive tumor necrosis factor/cachectin (TNF), interleukin-1β (IL-1β), interferon-γ (IFNγ, and interferon-α (IFNα) were prospectively measured in 70 patients with septic shock to determine their evolution and prognostic values. In a univariate analysis, levels of TNF (P = .002) and IL-1β (P = .05) were associated with the patient's outcome, but not IFNα (P = .15) and IFNγ (P = .26). In contrast, in a stepwise logistic regression analysis, the severity of the underlying disease (P = .01), the age of the patient (P = .02), the documentation of infection (nonbacteremic infections vs. bacteremias, P = .03), the urine output (P = .04), and the arterial pH (P = .05) contributed more significantly to prediction of patient outcome than the serum levels of TNF (P = .07). After 10 days, the median concentration of TNF was undetectable <100 pg/ml) in the survivors, whereas it remained elevated (305 pg/ml, P = .002) in the nonsurvivors. Thus, in patients with septic shock due to various gram-negative bacteria, other parameters than the absolute serum concentration of immunoreactive TNF contributed significantly to the prediction of outcom
Label-Free Glycoprofiling with Multiplex Surface Plasmon Resonance : A Tool to Quantify Sialylation of Erythropoietin
Protein glycosylation is among the most common and well-defined post-translational modifications due to its vital role in protein function. Monitoring variation in glycosylation is necessary for producing more effective therapeutic proteins. Glycans attached to glycoproteins interact highly specific with lectins, natural carbohydrate-binding proteins, which property is used in the current label-free methodology. We have established a lectin microarray for label-free detection of lectin-carbohydrate interactions allowing us to study protein glycosylation directly on unmodified glycoproteins. The method enables simultaneous measurement of up to 96 lectin-carbohydrate interactions on a multiplex surface plasmon resonance imaging platform within 20 min. Specificity determination of lectins succeeded by analysis of neoglycoproteins and enzymatically remodeled glycoproteins to verify carbohydrate binding. We demonstrated the possibilities for glycosylation fingerprinting by comparing different Erythropoietin sources without the need for any sample pretreatment and we were able to accurately quantify relative sialylation levels of Erythropoietin
Label-Free Glycoprofiling with Multiplex Surface Plasmon Resonance : A Tool to Quantify Sialylation of Erythropoietin
Protein glycosylation is among the most common and well-defined post-translational modifications due to its vital role in protein function. Monitoring variation in glycosylation is necessary for producing more effective therapeutic proteins. Glycans attached to glycoproteins interact highly specific with lectins, natural carbohydrate-binding proteins, which property is used in the current label-free methodology. We have established a lectin microarray for label-free detection of lectin-carbohydrate interactions allowing us to study protein glycosylation directly on unmodified glycoproteins. The method enables simultaneous measurement of up to 96 lectin-carbohydrate interactions on a multiplex surface plasmon resonance imaging platform within 20 min. Specificity determination of lectins succeeded by analysis of neoglycoproteins and enzymatically remodeled glycoproteins to verify carbohydrate binding. We demonstrated the possibilities for glycosylation fingerprinting by comparing different Erythropoietin sources without the need for any sample pretreatment and we were able to accurately quantify relative sialylation levels of Erythropoietin
Limited CD4+ T cell renewal in early stage of HIV-1 infection: effect of highly active antiretroviral therapy.
We show that the fraction of proliferating CD4+ lymphocytes is similar in HIV-infected subjects in the early stage of disease and in HIV-negative subjects, whereas the fraction of proliferating CD8+ lymphocytes is increased 6.8-fold in HIV-infected subjects. After initiation of antiviral therapy, there is a late increase in proliferating CD4+ T cells associated with the restoration of CD4+ T-cell counts. These results provide strong support for the idea of limited CD4+ T-cell renewal in the early stage of HIV infection and indicate that after effective suppression of virus replication, the mechanisms of CD4+ T-cell production are still functional in early HIV infection
Developing and testing an instrument to measure the presence of conditions for successful implementation of quality improvement collaboratives
Background: In quality improvement collaboratives (QICs) teams of practitioners from different
health care organizations are brought together to systematically improve an aspect of patient care.
Teams take part in a series of meetings to learn about relevant best practices, quality methods and
change ideas, and share experiences in making changes in their own local setting. The purpose of
this study was to develop an instrument for measuring team organization, external change agent
support and support from the team's home institution in a Dutch national improvement and
dissemination programme for hospitals based on several QICs.
Methods: The exploratory methodological design included two phases: a) content development
and assessment, resulting in an instrument with 15 items, and b) field testing (N = 165). Internal
consistency reliability was tested via Cronbach's alpha coefficient. Principal component analyses
were used to identify underlying constructs. Tests of scaling assumptions according to the multi
trait/multi-item matrix, were used to confirm the component structure.
Results: Three components were revealed, explaining 65% of the variability. The components
were labelled 'organizational support', 'team organization' and 'external change agent support'. One
item not meeting item-scale criteria was removed. This resulted in a 14 item instrument. Scale
reliability ranged from 0.77 to 0.91. Internal item consistency and divergent validity were
satisfactory.
Conclusion: On the whole, the instrument appears to be a promising tool for assessing team
organization and internal and external support during QIC implementation. The psychometric
properties were good and warrant application of the instrument for the evaluation of the national
programme and similar improvement programmes.
Limited CD4+ T-cell renewal in early HIV-1 infection: Effect of highly active antiretroviral therapy
Preface of the 2011 IAENG International Conference on Electrical Engineering Special Session: Design, analysis and tools for integrated circuits and systems
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