Uncertainty quantification for fat-tailed probability distributions in aircraft engine simulations

Rare event simulation is vital for industrial design because some events, so-called black swans, can have fatal consequences despite their low probability of occurrence. Finding low-probability events far off the mean design is a challenging task for realistic engineering models because they are characterized by high computational demands, many input variables, and often insufficient statistical information to build parametric probability distributions. Therefore, an adaptive and arbitrary polynomial chaos method, called sparse approximation of moment-based arbitrary polynomial chaos, is suggested in this work. Sparse approximation of moment-based arbitrary polynomial chaos creates custom polynomial basis functions and grids based on statistical moments to avoid incorrect statistical assumptions. The contribution of this work is that it is derived how rare event simulation can conveniently be integrated into adaptive sparse grid methods by calculating polynomial chaos expansions based on the statistical moments of truncated fat-tailed distributions. Moreover, the use of tempered alpha-stable distributions is suggested to avoid discontinuous tail cutoffs. Sparse approximation of moment-based arbitrary polynomial chaos is compared to other statistical methods in two industrial aircraft engine simulations: a simulation of transient cycle temperature in a turbine cavity and hot-gas ingestion in the interwheel region. In both cases, sparse approximation of moment-based arbitrary polynomial chaos agrees with previous results but obtains them with lower computational effort

Elimination of congenital rubella: a seroprevalence study of pregnant women and women of childbearing age in Italy

Prevention of congenital rubella is achieved by vaccination of susceptible women of childbearing age. In Italy, the National Plan for Measles and Congenital Rubella Elimination 2010–2015 implemented catch-up vaccination activities targeting susceptible adolescents and young adults, including women of childbearing age. The aim of this study was to assess the immunity against rubella in women of childbearing age in Tuscany (Central Italy) and Apulia (Southern Italy) and pregnant women in Apulia after the implementation of the National Plan for Measles and Congenital Rubella Elimination. Overall, anti-rubella IgG prevalence in women of childbearing age samples was 88.6% in Tuscany and 84.3% in Apulia. The lowest prevalence was observed in samples of 26–35 years old women of childbearing age in Apulia with 77.8%. Only 62.7% of samples from 26–35 years old pregnant women had IgG against rubella, and one sample out of 95 was positive to IgM. The findings of this study highlight the need for increasing awareness on the risk of contracting rubella infection during pregnancy and implement vaccination strategies to create opportunities for administration of rubella containing vaccines in young girls and women of childbearing age

Mapping host-related correlates of influenza vaccine-induced immune response: An umbrella review of the available systematic reviews and meta-analyses

Seasonal influenza is the leading infectious disease in terms of its health and socioeconomic impact. Annual immunization is the most efficient way to reduce this burden. Several correlates of influenza vaccine-induced protection are commonly used, owing to their ready availability and cheapness. Influenza vaccine-induced immunogenicity is a function of host-, virus-and vaccine-related factors. Host-related factors constitute the most heterogeneous group. The objective of this study was to analyze the available systematic evidence on the host factors able to modify influenza vaccine-induced immunogenicity. An umbrella review approach was undertaken. A total of 28 systematic reviews/meta-analyses were analyzed—these covered the following domains: intravenous drug use, psychological stress, acute and chronic physical exercise, genetic polymorphisms, use of pre-/pro-/symbiotics, previous Bacillus Calmette–Guérin vaccination, diabetes mellitus, vitamin D supplementation/deficiency, latent cytomegalovirus infection and various forms of immunosuppression. In order to present effect sizes on the same scale, all possible meta-analyses were re-performed and cumulative evidence synthesis ranking was carried out. The meta-analysis was conducted separately on each health condition category and virus (sub)type. A total of 97 pooled estimates were used in order to construct an evidence-based stakeholder-friendly map. The principal public health implications are discussed

Surveillance for Antimicrobial Resistance in Croatia

This study intended to verify, through microbiological techniques and TEM investigations, the killing of bacterial spores after treatment in steam autoclave, and to propose strictly morphological considerations about the target of this sterilisation process. Autoclave is the most common device for sterilising instruments in order to prevent cross infections in dental offices. The autoclave efficiency has been improved in the last years and part of this improvement is related to both a better and more correct use of the autoclave system and to the technological innovations introduced in the last generation of devices. However, associations as ADA or CDC suggest to regularly verify the process of 'autoclaving' through biological indicators (BI). The most commonly used BI are made of spores strips or suspensions of Bacillus Subtilis (pb 168) and Bacillus Stearothermophilus (ATCC 10149). They visually prove, changing colours on enzymatic base, the death of micro-organism and if the physical parameters, necessary for sterilisation, have been achieved. These two strains of endospore-forming bacteria were processed and prepared following two different techniques: Karnovsky fixed and epon embedded--phosphotungstic acid fixed for direct observation. The kind and the extent of analysed modifications are extremely various: from deep lacerations, which changed the spore structure, to little clefts which let the cytoplasm go out

Cross subclade immunity after one-year booster immunization with MF59®-adjuvanted A/H5N1 influenza vaccine in 6 month to 17 year-old children

Background: Since 2006 when the zoster vaccine was first icensed, one of the most commonly asked questions by patients nd clinicians has been "Should a patient with a history of herpes oster (HZ) receive the vaccine to prevent another episode?". The enefit of vaccinating immunocompetent patients who have had hingles has not been examined. The study assessed the association etween vaccination and the incidence of herpes zoster recurrence mong personswith a recent episode of clinically diagnosed herpes oster. Methods: This is a matched cohort study in Kaiser Permanente outhern California. Study populations were immunocompetent lderly≥ 60 years oldwith a recent episode of herpes zoster. Potenial recurrent HZ cases were identified electronically by ICD-9 code f 053.xx from outpatient, emergency, and inpatient files. Medcal records of electronically identified cases were retrieved and eviewed masked to vaccination status by an infectious disease pecialist using pre-specified review criteria. Incidence of recurent herpes zoster was compared between the vaccinated and the nvaccinated matched cohorts. The hazard ratio associated with accination was adjusted for a propensity score that accounted for otential confounders. Results: There were total 1,036 vaccinated and 5,180 unvacciated members included. Based on the clinically confirmed cases, he incidence of recurrent HZ among age <70 cohort was 0.99 (95% I, 0.02-5.54) and 2.20 (95% CI, 1.10-3.93) per 1,000 person-year

Generalization of particle impact behavior in gas turbine via non-dimensional grouping

Fouling in gas turbines is caused by airborne contaminants which, under certain conditions, adhere to aerodynamic surfaces upon impact. The growth of solid deposits causes geometric modifications of the blades in terms of both mean shape and roughness level. The consequences of particle deposition range from performance deterioration to life reduction to complete loss of power. Due to the importance of the phenomenon, several methods to model particle sticking have been proposed in literature. Most models are based on the idea of a sticking probability, defined as the likelihood a particle has to stick to a surface upon impact. Other models investigate the phenomenon from a deterministic point of view by calculating the energy available before and after the impact. The nature of the materials encountered within this environment does not lend itself to a very precise characterization, consequently, it is difficult to establish the limits of validity of sticking models based on field data or even laboratory scale experiments. As a result, predicting the growth of solid deposits in gas turbines is still a task fraught with difficulty. In this work, two nondimensional parameters are defined to describe the interaction between incident particles and a substrate, with particular reference to sticking behavior in a gas turbine. In the first part of the work, historical experimental data on particle adhesion under gas turbine-like conditions are analyzed by means of relevant dimensional quantities (e.g. particle viscosity, surface tension, and kinetic energy). After a dimensional analysis, the data then are classified using non-dimensional groups and a universal threshold for the transition from erosion to deposition and from fragmentation to splashing based on particle properties and impact conditions is identified. The relation between particle kinetic energy/surface energy and the particle temperature normalized by the softening temperature represents the original non-dimensional groups able to represent a basis of a promising adhesion criterion

Immunogenicity measures of influenza vaccines: A study of 1164 registered clinical trials

Influenza carries an enormous burden each year. Annual influenza vaccination is the best means of reducing this burden. To be clinically effective, influenza vaccines must be immunogenic, and several immunological assays to test their immunogenicity have been developed. This study aimed to describe the patterns of use of the various immunological assays available to measure the influenza vaccine-induced adaptive immune response and to determine its correlates of protection. A total of 76.5% of the studies included in our analysis measured only the humoral immune response. Among these, the hemagglutination-inhibition assay was by far the most widely used. Other, less common, humoral immune response assays were: virus neutralization (21.7%), enzyme-linked immunosorbent (10.1%), single radial hemolysis (4.6%), and assays able to quantify anti-neuraminidase antibodies (1.7%). By contrast, cell-mediated immunity was quantified in only 23.5% of studies. Several variables were significantly associated with the use of single assays. Specifically, some influenza vaccine types (e.g., adjuvanted, live attenuated and cell culture-derived or recombinant), study phase and study sponsorship pattern were usually found to be statistically significant predictors. We discuss the principal findings and make some suggestions from the point of view of the various stakeholders

Chlamydia pneumoniae antibodies and angiographically demonstrated coronary artery disease in a sample population from Italy

Recent reports suggest an association between Chlamydia pneumoniae and chronic coronary heart disease. This case-control study investigates the relationship between the presence of immunoglobin G (IgG) and immunoglobin A (IgA) when measured by means of microimmunofluorescence (MIF) and angiographically diagnosed coronary disease. Cases (n = 150) were angiography patients with at least one coronary artery lesion occupying at least 50% of the luminal diameter. Controls (n = 49) were angiography patients with no detectable signs of coronary artery disease and patients (n = 56) without signs or symptoms of coronary disease and with normal ECG results. No significant differences were revealed between the seroprevalence of IgG and IaA and geometric mean titers (GMT) as measured in cases and controls. When cases were compared with controls whose angiographic results were normal, after adjusting for established risk factors (cholesterol, smoking, hypertension, diabetes, age, gender and family history), the estimated risk of coronary artery disease was 0.79 (95% confidence interval (C.I.), 0.31-1.99) for the presence of IgG and was 0.94 (95 C.I., 0.37-2.39) for IgA. When cases were compared with controls with normal ECG results, the adjusted odds ratio (O.R.) for coronary artery disease was 1.17 (95%, C.I., 0.52-2.62) for the presence of IgG and 0.82 195% C.I., 0.36-1.86) for the presence of IgA. These results do not support an association between C. pneumoniae infection and coronary disease

Mapping host-related correlates of influenza vaccine-induced immune response: An umbrella review of the available systematic reviews and meta-analyses

Seasonal influenza is the leading infectious disease in terms of its health and socioeconomic impact. Annual immunization is the most efficient way to reduce this burden. Several correlates of influenza vaccine-induced protection are commonly used, owing to their ready availability and cheapness. Influenza vaccine-induced immunogenicity is a function of host-, virus-and vaccine-related factors. Host-related factors constitute the most heterogeneous group. The objective of this study was to analyze the available systematic evidence on the host factors able to modify influenza vaccine-induced immunogenicity. An umbrella review approach was undertaken. A total of 28 systematic reviews/meta-analyses were analyzed—these covered the following domains: intravenous drug use, psychological stress, acute and chronic physical exercise, genetic polymorphisms, use of pre-/pro-/symbiotics, previous Bacillus Calmette–Guérin vaccination, diabetes mellitus, vitamin D supplementation/deficiency, latent cytomegalovirus infection and various forms of immunosuppression. In order to present effect sizes on the same scale, all possible meta-analyses were re-performed and cumulative evidence synthesis ranking was carried out. The meta-analysis was conducted separately on each health condition category and virus (sub)type. A total of 97 pooled estimates were used in order to construct an evidence-based stakeholder-friendly map. The principal public health implications are discussed