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A comprehensive study of the fundamental characteristics of leading-edge separation in rarefied hypersonic flows is undertaken and its salient features are elucidated. Separation of a boundary layer undergoing strong expansion is typical in many practical hypersonic applications such as base flows of re-entry vehicles and flows over deflected control surfaces. Boundary layer growth under such conditions is influenced by effects of rarefaction and thermal non-equilibrium, thereby differing significantly from the conventional no-slip Blasius type. A leading-edge separation configuration presents a fundamental case for studying the characteristics of such a flow separation but with minimal influence from a pre-existing boundary layer. In this work, direct simulation Monte Carlo computations have been performed to investigate flow separation and reattachment in a low-density hypersonic flow over such a configuration. Distinct features of leading-edge flow, limited boundary layer growth, separation, shear layer, flow structure in the recirculation region and reattachment are all explained in detail. The fully numerical shear layer profile after separation is compared against a semi-theoretical profile, which is obtained using the numerical separation profile as the initial condition on existing theoretical concepts of shear layer analysis based on continuum flow separation. Experimental studies have been carried out to determine the surface heat flux using thin-film gauges and computations showed good agreement with the experimental data. Flow visualisation experiments using the non-intrusive planar laser-induced fluorescence technique have been performed to image the fluorescence of nitric oxide, from which velocity and rotational temperature distributions of the separated flow region are determined.
Optimising short- and long-term outcomes for children and patients with CHD depends on continued scientific discovery and translation to clinical improvements in a coordinated effort by multiple stakeholders. Several challenges remain for clinicians, researchers, administrators, patients, and families seeking continuous scientific and clinical advancements in the field. We describe a new integrated research and improvement network – Cardiac Networks United – that seeks to build upon the experience and success achieved to-date to create a new infrastructure for research and quality improvement that will serve the needs of the paediatric and congenital heart community in the future. Existing gaps in data integration and barriers to improvement are described, along with the mission and vision, organisational structure, and early objectives of Cardiac Networks United. Finally, representatives of key stakeholder groups – heart centre executives, research leaders, learning health system experts, and parent advocates – offer their perspectives on the need for this new collaborative effort.
Collaborative quality improvement and learning networks have amended healthcare quality and value across specialities. Motivated by these successes, the Pediatric Acute Care Cardiology Collaborative (PAC3) was founded in late 2014 with an emphasis on improving outcomes of paediatric cardiology patients within cardiac acute care units; acute care encompasses all hospital-based inpatient non-intensive care. PAC3 aims to deliver higher quality and greater value care by facilitating the sharing of ideas and building alignment among its member institutions. These aims are intentionally aligned with the work of other national clinical collaborations, registries, and parent advocacy organisations. The mission and early work of PAC3 is exemplified by the formal partnership with the Pediatric Cardiac Critical Care Consortium (PC4), as well as the creation of a clinical registry, which links with the PC4 registry to track practices and outcomes across the entire inpatient encounter from admission to discharge. Capturing the full inpatient experience allows detection of outcome differences related to variation in care delivered outside the cardiac ICU and development of benchmarks for cardiac acute care. We aspire to improve patient outcomes such as morbidity, hospital length of stay, and re-admission rates, while working to advance patient and family satisfaction. We will use quality improvement methodologies consistent with the Model for Improvement to achieve these aims. Membership currently includes 36 centres across North America, out of which 26 are also members of PC4. In this report, we describe the development of PAC3, including the philosophical, organisational, and infrastructural elements that will enable a paediatric acute care cardiology learning network.
Across the globe, the implementation of quality improvement science and collaborative learning has positively affected the care and outcomes for children born with CHD. These efforts have advanced the collective expertise and performance of inter-professional healthcare teams. In this review, we highlight selected quality improvement initiatives and strategies impacting the field of cardiovascular care and describe implications for future practice and research. The continued leveraging of technology, commitment to data transparency, focus on team-based practice, and recognition of cultural norms and preferences ensure the success of sustainable models of global collaboration.
We use methods of differential astrometry to construct a small field inertial reference frame stable at the micro-arcsecond level. Using Gaia measurements of field angles we look at the influence of the number of reference stars and the stars magnitude as well as astrometric systematics on the total error budget with the help of Gaia-like simulations around the Ecliptic Pole in a differential astrometric scenario. We find that the systematic errors are modeled and reliably estimated to the μas level even in fields with a modest number of 37 stars with G <13 mag over a 0.24 sq. degrees field of view for short timescales of the order of a day for a perfect instrument and with high-cadence observations. Accounting for large-scale calibrations by including the geometric instrument model over such short timescales requires fainter stars down to G=14 mag without diminishing the accuracy of the reference frame.
A K-band (18-25 GHz) reflected-wave ruby maser (Moore and Clauss 1979) has been borrowed from the National Radio Astronomy Observatory for radio astronomy use on the NASA 64-m antenna of the Deep Space Network at the Tidbinbilla Tracking Station, near Canberra. The purpose of the installation is to provide additional sensitive spectral line, continuum, and VLBI capabilities in the southern hemisphere. Previous measurements at 22.3 GHz (λ = 13.5 mm) determined that the Tidbinbilla 64-m antenna has a peak aperture efficiency of ˜22%, a well-behaved beam shape and consistent pointing (Fourikis and Jauncey 1979). Before installing the maser on the antenna a cooled (circulator) switch was added to provide a beam-switching capability, and a spectral line receiver following the maser was incorporated. The system was assembled and tested at JPL in late 1980 and installed at Tidbinbilla early in 1981. We give here a brief description and present some of the first line observations made in February and March 1981. Extensive line and continuum observations are planned with the present system and a program is under way to determine the telescope pointing characteristics.
Echinacea pallida (EPAL), a herbaceous flowering plant with immunomodulatory properties, has been chosen to determine the pre- and post-supplementary effects on the growth performances, bacterial community, blood parameters and immunity of growing rabbits. The same Grimaud does (14-week-old) from the studied in the first part of this study were randomly divided into two groups (n=50/group). The first group was fed a basal diet without supplementation (Control group, C) while the another group was fed a basal diet supplemented with 3 g EPAL/kg diet (Echinacea group, E). From the second parturition, 80 weaned kits (40 from the C does and 40 from the E does) were randomly assigned to four groups of 20 animals each and were fed a growing commercial diet supplemented with or without a 3 g EPAL/kg diet: the CC group (rabbits from the C does fed the control diet), CE group (rabbits from the C does fed the supplemented diet), EC (rabbits from the E does fed the control diet) and EE group (rabbits from the E does fed the supplemented diet). The dietary EPAL treatment did not affect the growth performance. Ten fattening rabbits from each group were selected to evaluate the bacterial community and blood parameters, while the remaining rabbits (n=10/group) were used to study phagocytosis and the humoral immune response. The variability was evaluated from hard faeces at 35, 49 and 89 days, and the caecal content at 89 days. The variability of the bacterial community of the EE group was higher than that of the other groups. The phagocytic activity was higher in the CE and EE groups than in the CC and EC ones (30.9 and 29.7 v. 21.2 and 21.8%; P<0.05), whereas no statistically significant difference was observed for the blood parameters or humoral immune response against vaccination (rabbit haemorrhagic disease virus) at 95 days old which the serum was collected at 88, 102, 109, 116 and 123 days old. In conclusion, no impact of EPAL dietary supplementation has been observed on the growth performances, bacterial community, blood parameters or humoral immune responses in growing rabbits, except for an increase in phagocytic activities.
The optimal perioperative feeding strategies for neonates with CHD are unknown. In the present study, we describe the current feeding practices across a multi-institutional cohort.
Inclusion criteria for this study were as follows: all neonates undergoing cardiac surgery admitted to the cardiac ICU for ⩾24 hours preoperatively between October, 2013 and July, 2014 in the Pediatric Cardiac Critical Care Consortium registry.
The cohort included 251 patients from eight centres. The most common diagnoses included the following: hypoplastic left heart syndrome (17%), coarctation/aortic arch hypoplasia (18%), and transposition of the great arteries (22%); 14% of the patients were <37weeks of gestational age. The median total hospital length of stay was 21 days (interquartile range (IQR) 14–35) and overall mortality was 8%. Preoperative feeding occurred in 133 (53%) patients. The overall preoperative feeding rates across centres ranged from 29 to 79%. Postoperative feeds started on median day 2 (IQR 1–4); for patients with hypoplastic left heart syndrome postoperative feeds started on median day 4. Postoperative feeds were initiated in 89 (35%) patients before extubation (range across centres: 21–61%). The median cardiac ICU discharge feeding volume was 108 cc/kg/day, varying across centres. The mean discharge weight was 280 g above birth weight, ranging from +100 to 430 g across centres. A total of 110 (44%) patients had discharge feeding tubes, ranging from 6 to 80% across centres, and 40/110 patients had gastrostomy/enterostomy tubes placed. In addition, eight (3.2%) patients developed necrotising enterocolitis – three preoperatively and five postoperatively.
In this cohort, neonatal feeding practices and outcomes appear to vary across diagnostic groups and institutions. Only half of the patients received preoperative enteral nutrition; almost half had discharge feeding tubes. Multi-institutional collaboration is necessary to determine feeding strategies associated with best clinical outcomes.
Clinical databases in congenital and paediatric cardiac care provide a foundation for quality improvement, research, policy evaluations and public reporting. Structured audits verifying data integrity allow database users to be confident in these endeavours. We report on the initial audit of the Pediatric Cardiac Critical Care Consortium (PC4) clinical registry.
Materials and methods
Participants reviewed the entire registry to determine key fields for audit, and defined major and minor discrepancies for the audited variables. In-person audits at the eight initial participating centres were conducted during a 12-month period. The data coordinating centre randomly selected intensive care encounters for review at each site. The audit consisted of source data verification and blinded chart abstraction, comparing findings by the auditors with those entered in the database. We also assessed completeness and timeliness of case submission. Quantitative evaluation of completeness, accuracy, and timeliness of case submission is reported.
We audited 434 encounters and 29,476 data fields. The aggregate overall accuracy was 99.1%, and the major discrepancy rate was 0.62%. Across hospitals, the overall accuracy ranged from 96.3 to 99.5%, and the major discrepancy rate ranged from 0.3 to 0.9%; seven of the eight hospitals submitted >90% of cases within 1 month of hospital discharge. There was no evidence for selective case omission.
Based on a rigorous audit process, data submitted to the PC4 clinical registry appear complete, accurate, and timely. The collaborative will maintain ongoing efforts to verify the integrity of the data to promote science that advances quality improvement efforts.
In this study, 160 Hycole weaned rabbits (35 days old) were randomly divided into four groups of 40. The rabbits were studied throughout a 54-day experimentation period in order to determine the impact of dietary supplementation from herbs composed of 0.2%, 0.4% dry ground Lythrum salicaria leaves (LS) and 0.3% Cunirel® (CR; a commercial herb mixture containing LS as the main ingredient) on performance, digestibility, health and meat quality. The basal diet was given to the control group. No significant differences were found in performance, 10 rabbits from each group were selected for evaluation regarding apparent digestibility. The rabbits fed the control diet and the diet with the low level of LS had a higher level of CP digestibility than did the animals that were supplemented with the high LS levels and CR (85.7% and 84.9% v. 84.0% and 84.0%, respectively; P<0.05). The ether extract digestibility was lower in the treatment group with 0.4%LS addition and CR as compared with the control group (52.2% and 54.5% v. 62.6%, respectively; P<0.05). The slaughter process was performed on 89-day-old rabbits to study the carcass characteristics, meat quality, blood parameters, caecal contents and gut histology. The total leukocyte counts in the control animals were lower than they were in the rabbits fed 0.2%, 0.4%LS and CR (4.06 v. 8.25, 8.63 and 8.21×109/l, respectively; P<0.05). For caecal fermentation, the caecal contents of the rabbits fed 0.4% of LS, showed higher concentrations of total volatile fatty acid (VFA; 24.1 v. 18.9 mg/kg dry matter (DM); P<0.05) and acetic acid (18.3 v. 14.4 mg/kg DM; P<0.05), but lower ammonia levels (594 v. 892 mg/kg DM; P<0.05) as compared with the control group. PCR-denaturing gradient gel electrophoresis analyses were performed to evaluate the microbial community in hard faeces, collected at days 35, 42, 49, 56, 70 and 89, whereas the caecal contents were taken after slaughtering. The results demonstrated that between the treatment groups, the similarity of the microbial communities was higher as compared with the control group. Moreover, only age was shown to influence microbiota diversity. In conclusion, the results of this study indicated that supplementation of LS in rabbit diets leads to an increase in the total white blood cells, total VFA and acetic acid concentration, and a decrease in the ammonia levels, as well as the digestibility when CR and high level of LS were supplemented, without causing any adverse effects on other parameters.
Despite many advances in recent years for patients with critical paediatric and congenital cardiac disease, significant variation in outcomes remains across hospitals. Collaborative quality improvement has enhanced the quality and value of health care across specialties, partly by determining the reasons for variation and targeting strategies to reduce it. Developing an infrastructure for collaborative quality improvement in paediatric cardiac critical care holds promise for developing benchmarks of quality, to reduce preventable mortality and morbidity, optimise the long-term health of patients with critical congenital cardiovascular disease, and reduce unnecessary resource utilisation in the cardiac intensive care unit environment. The Pediatric Cardiac Critical Care Consortium (PC4) has been modelled after successful collaborative quality improvement initiatives, and is positioned to provide the data platform necessary to realise these objectives. We describe the development of PC4 including the philosophical, organisational, and infrastructural components that will facilitate collaborative quality improvement in paediatric cardiac critical care.
In this study, the effects of the inclusion of artichoke bracts (AB) in rabbit diets on the carcass characteristics and rabbit meat quality were studied. A total of 120 rabbits aged 38 days were used and divided into three groups that were fed with different isonitrogenous and isocaloric diets supplemented with AB at 0%, 5% and 10%. The animals were single housed in wire cages at a temperature of 22±2°C and had free access to clean drinking water. At 96 days of age, 12 rabbits/group were slaughtered in an experimental slaughterhouse without fasting. The carcass was weighed and the weights of the skin and full gastrointestinal tract were recorded. Carcasses were chilled at +4°C for 24 h in a refrigerated room. The chilled carcass weight (CCW), dressing out percentage (CCW as percentage of slaughter weight), and the ratio of the head and liver were determined as a percentage of CCW. The reference carcass weight was also calculated. Carcasses were halved and the two longissimus dorsi (LD) muscles were excised. The left LD muscle was divided into two parts. The fore part was used to measure pH, colour and cooking losses. The hind part of the left LD was vacuum-packed, frozen at –20°C and then freeze-dried. Proximate composition, fatty-acid profile and thiobarbituric acid-reactive substances values were determined on freeze-dried samples. Results showed that carcass characteristics, LD muscle traits and its oxidative status were not affected by the AB supplementation, except for the meat ether extract content that increased from 0.68% to 0.94% on fresh matter basis with the increase of the AB supplementation (P<0.01). The α-linolenic acid proportion decreased with the increase of the AB supplementation from 3.58% to 2.59% in the LD muscle and from 4.74% to 3.62% in the perirenal fat, whereas the n-6/n-3 ratio increased significantly with increasing AB inclusion from 7.15 to 10.20 in the LD muscle and from 6.68 to 9.35 in the perirenal fat (P<0.01). Furthermore, no significant difference was found in preference among meat samples from each group. The enrichment of the rabbit’s diet with AB allows the production of rabbit meat with a good degree of unsaturation and low saturation, even if the n-6/n-3 ratio was slightly worse.
Today, to cope with the complexity of the global organization, the industrial company
needs to be more structured. New processes have to be developed due to more and more
ambitious quality requirements. A new problematic arises: what is needed to offer to all
customers a product that meets the quality requirements of a local market? The main
objective of this paper is to propose a quality requirements allocation method that
matches the market specifications and the customer satisfaction. This is in contrast with
the traditional allocation methods which are often time-consuming to implement or do not
focus on the customer satisfaction for the definition of the quality targets. The proposed
method is inspired from reliability allocation method and is formulated as a feasibility
problem. In this context the notion of optimality of the solution is not being sought, the
objective is “only” to find out a solution that satisfies the global target quality. This
allows determining some local quality targets in accordance with industrial data.
For a better understanding of the physical phenomena associated with the appearance of defects in laser welding, a heat and fluid flow model is developed using Comsol Multiphysics®. This first step of the project is focused on the modeling of a static laser shot on a sample of steel. This 2D axially-symmetric configuration is used to study the main physical phenomena related to the creation of the keyhole. This model takes into account the three phases of the matter: the vaporized metal, the liquid phase and the solid base. To track the evolution of these three phases, coupled equations of energy and momentum are solved. The liquid/vapor interface is tracked using the Level-Set method. The calculated velocity and free surface deformation are analyzed. Melt pool shapes are compared with experimental macrographs and the influence of some parameters such as laser power is discussed.
Although overall outcomes for children undergoing heart surgery have improved, there is a significant variation in outcomes across hospitals. This review discusses the variation in cost and outcomes across centres performing congenital heart surgery, potential underlying mechanisms, and efforts to reduce variation and improve outcome.
Polymer nanocomposites (PNC) are complex material systems in which the dominant length scales converge. Our approach to understanding nanocomposite tradespace uses Materials Quantitative Structure-Property Relationships (MQSPRs) to relate molecular structures to the polar and dispersive components of corresponding surface tensions. If the polar and dispersive components of surface tensions in the nanofiller and polymer could be determined a priori, then the propensity to aggregate and the change in polymer mobility near the particle could be predicted. Derived energetic parameters such as work of adhesion, work of spreading and the equilibrium wetting angle may then used as input to continuum mechanics approaches that have been shown able to predict the thermomechanical response of nanocomposites and that have been validated by experiment. The informatics approach developed in this work thus enables future in silico nanocomposite design by enabling virtual experiments to be performed on proposed nanocomposite compositions prior to fabrication and testing.