Standard Bundles Research Articles

Hodge and Prym Tau Functions, Strebel Differentials and Combinatorial Model of $${\mathcal {M}}_{g,n}$$

The goal of the paper is to apply the theory of integrable systems to construct explicit sections of line bundles over the combinatorial model of the moduli space of pointed Riemann surfaces based on Strebel differentials. These line bundles are tensor products of the determinants of the Hodge or Prym vector bundles with the standard tautological line bundles $$\mathcal {L}_j$$ , and the sections are constructed in terms of tau functions. The combinatorial model is interpreted as the real slice of a complex analytic moduli space of quadratic differentials where the phase of each tau-function provides a section of a circle bundle. The phase of the ratio of the Prym and Hodge tau functions gives a section of the $$\kappa _1$$ -circle bundle. By evaluating the increment of the phase around co-dimension 2 sub-complexes, we identify the Poincare dual cycles to the Chern classes of the corresponding line bundles: they are expressed explicitly as combination of Witten’s cycle $$W_{5} $$ and Kontsevich’s boundary. This provides combinatorial analogues of Mumford’s relations on $${\mathcal {M}}_{g,n}$$ and Penner’s relations in the hyperbolic combinatorial model. The free homotopy classes of loops around $$W_{5} $$ are interpreted as pentagon moves while those of loops around Kontsevich’s boundary as combinatorial Dehn twists. Throughout the paper we exploit the classical description of the combinatorial model in terms of Strebel differentials, parametrized in terms of period, or homological coordinates; we show that they provide Darboux coordinates for the symplectic structure introduced by Kontsevich. We also express the latter as the intersection pairing in the odd homology of the canonical double cover.

Implementation interventions in preventing surgical site infections in abdominal surgery: a systematic review

BackgroundSurgical site infections (SSIs) are highly prevalent in abdominal surgery despite evidence-based prevention measures. Since guidelines are not self-implementing and SSI-preventive compliance is often insufficient, implementation interventions have been developed to promote compliance. This systematic review aims to identify implementation interventions used in abdominal surgery to prevent SSIs and determine associations with SSI reductions.MethodsLiterature was searched in April 2018 (Medline/PubMed and Web of Science Core Collection). Implementation interventions were classified using the implementation subcategories of the EPOC Taxonomy (Cochrane Review Group Effective Practice and Organisation of Care, EPOC). Additionally, an effectiveness analysis was conducted on the association between the number of implementation interventions, specific compositions thereof, and absolute and relative SSI risk reductions.ResultsForty studies were included. Implementation interventions used most frequently (“top five”) were audit and feedback (80% of studies), organizational culture (70%), monitoring the performance of healthcare delivery (65%), reminders (53%), and educational meetings (45%). Twenty-nine studies (72.5%) used a multimodal strategy (≥3 interventions). An effectiveness analysis revealed significant absolute and relative SSI risk reductions. E.g., numerically, the largest absolute risk reduction of 10.8% pertained to thirteen studies using 3–5 interventions (p < .001); however, this was from a higher baseline rate than those with fewer or more interventions. The largest relative risk reduction was 52.4% for studies employing the top five interventions, compared to 43.1% for those not including these. Furthermore, neither the differences in risk reduction between studies with different numbers of implementation interventions (bundle size) nor between studies including the top five interventions (vs. not) were significant.ConclusionIn SSI prevention in abdominal surgery, mostly standard bundles of implementation interventions are applied. While an effectiveness analysis of differences in SSI risk reduction by number and type of interventions did not render conclusive results, use of standard interventions such as audit and feedback, organizational culture, monitoring, reminders, and education at least does not seem to represent preventive malpractice. Further research should determine implementation interventions, or bundles thereof, which are most effective in promoting compliance with SSI-preventive measures in abdominal surgery.

From Auditor to Coach: Implementation of Kamishibai-Card Rounding for Compliance Monitoring

BACKGROUND Standardized care bundles are a critical component in preventing healthcare-associated conditions (HAC) in hospitalized patients. Adherence to prevention practice bundles ensures that staff follow highly reliable practices to reduce patient harm. At a large academic children's hospital, compliance with standard care bundles was historically monitored using manual audits comprised of chart and direct observations. This process lacked opportunities to engage staff directly. In response, a Lean improvement tool called Kamishibai Cards (K-Cards) were implemented to promote meaningful bedside discussions. METHODS In August 2016, the initial K-Card pilot was implemented in the Cardiac Intensive Care Unit (CICU) and focused on the bundle for?Central Line-Associated Bloodstream Infections (CLABSI). A Plan-Do-Study-Act model of improvement was utilized. After four weeks, a post survey was distributed to staff to assess knowledge, effectiveness and satisfaction with the rounding process. With continued positive responses, K-Card use quickly expanded to other units across all nine HAC work streams and in September 2017 replaced traditional audits hospital-wide. A systematic communication and conversion plan was developed, including educational toolkits and strategies to ensure inter-rater reliability. RESULTS Post-pilot survey results showed that K-Cards increased understanding of bundle practices for 60% of respondents, improved the ability to care for patients with central lines for 50%, and enhanced educational experience for 90%. Since conversion, preliminary feedback has indicated richer, meaningful teaching moments and understanding of the bundles. CLABSI provides one example: following the transition, compliance took a dip as conversation revealed gaps in understanding. K-Card coaching allowed teams to immediately address gaps, and compliance increased back above 90%. CONCLUSIONS The implementation of K-card rounding has allowed structured just-in-time feedback and changed the audit process to one that is valuable for staff. By promoting more meaningful discussions at the bedside, K-cards are an important tool in influencing organizational culture around prevention practices.

Effect of the application of a bundle of three measures (intraperitoneal lavage with antibiotic solution, fascial closure with Triclosan-coated sutures and Mupirocin ointment application on the skin staples) on the surgical site infection after elective laparoscopic colorectal cancer surgery.

Surgical site infection (SSI) prevention bundles include the simultaneous use of different measures, which individually have demonstrated an effect on prevention of SSI. The implementation of bundles can yield superior results to the implementation of individual measures. The aim of this study was to address the effect of the application of a bundle including intraperitoneal lavage with antibiotic solution, fascial closure with Triclosan-coated sutures and Mupirocin ointment application on the skin staples, on the surgical site infection after elective laparoscopic colorectal cancer surgery. A prospective, randomized study was performed, including patients with diagnosis of colorectal neoplasms and plans to undergo an elective laparoscopic surgery. The patients were randomized into two groups: those patients following standard bundles (Group 1) and those ones following the experimental bundle with three additional measures, added to the standard bundle. Incisional and organ space SSI were investigated. The study was assessor-blinded. A total of 198 patients were included in the study, 99 in each group. The incisional SSI rate was 16% in Group 1 and 2% in Group 2 [p = 0.007; RR = 5.6; CI 95% (1.4-17.8)]. The organ-space SSI rate was 4% in Group 1 and 0% in Group 2 [p = 0.039; RR = 1.7; CI 95% (1.1-11.6)]. Median hospital stay was 5.5 days in Group 1 and 4 days in Group 2 (p = 0.028). The addition of intraperitoneal lavage with antibiotic solution, fascial closure with Triclosan-coated sutures and Mupirocin ointment application on the skin staples, to a standard bundle of SSI prevention, reduces the incisional and organ-space SSI and consequently the hospital stay, after elective laparoscopic colorectal cancer surgery (ClinicalTrials.gov Identifier: NCT03081962).

Standard Bundles Simplify Standards-based Quantification in NIST DTSA-II

Standard Bundles Simplify Standards-based Quantification in NIST DTSA-II

Mucosal Barrier Injury Central Line-Associated Bloodstream Infections: What Is the Impact of Standard Prevention Bundles?

Mucosal Barrier Injury Central Line-Associated Bloodstream Infections: What Is the Impact of Standard Prevention Bundles?

Flow cytometry data standards

BackgroundFlow cytometry is a widely used analytical technique for examining microscopic particles, such as cells. The Flow Cytometry Standard (FCS) was developed in 1984 for storing flow data and it is supported by all instrument and third party software vendors. However, FCS does not capture the full scope of flow cytometry (FCM)-related data and metadata, and data standards have recently been developed to address this shortcoming.FindingsThe Data Standards Task Force (DSTF) of the International Society for the Advancement of Cytometry (ISAC) has developed several data standards to complement the raw data encoded in FCS files. Efforts started with the Minimum Information about a Flow Cytometry Experiment, a minimal data reporting standard of details necessary to include when publishing FCM experiments to facilitate third party understanding. MIFlowCyt is now being recommended to authors by publishers as part of manuscript submission, and manuscripts are being checked by reviewers and editors for compliance. Gating-ML was then introduced to capture gating descriptions - an essential part of FCM data analysis describing the selection of cell populations of interest. The Classification Results File Format was developed to accommodate results of the gating process, mostly within the context of automated clustering. Additionally, the Archival Cytometry Standard bundles data with all the other components describing experiments. Here, we introduce these recent standards and provide the very first example of how they can be used to report FCM data including analysis and results in a standardized, computationally exchangeable form.ConclusionsReporting standards and open file formats are essential for scientific collaboration and independent validation. The recently developed FCM data standards are now being incorporated into third party software tools and data repositories, which will ultimately facilitate understanding and data reuse.

Birational and numerical geometry of the variety of complete pairs of two-point spaces on an algebraic surface

In this paper the birational surgeries that are necessary to regularize the “addition” of pairs of points to an algebraic surface are described. The pattern of the description is the addition of points to an algebraic surface, which requires the single blow-up of a smooth subvariety, namely, the diagonal in the direct product of the surface by itself. The complete description of the blow-ups leads to a description of the geometry (the ring of algebraic cycles) and the numerical invariants, i.e., the products of the Chern classes of the standard vector bundles on order 4 Hilbert schemes of algebraic surfaces.

Fuel Channel Analysis for a Large-Break Loss-of-Coolant Accident in a Canada Deuterium Uranium Reactor Loaded with CANFLEX Fuel Bundles

The CATHENA ``slave`` channel model is used for fuel channel analysis of a 30% reactor inlet header break in a Canada deuterium uranium (CANDU)-6 reactor loaded with 43-element bundles of advanced CANDU [CANDU flexible fueling (CANFLEX)] fuel. The predicted results are compared with those for the reactor loaded with standard 37-element bundles. The maximum fuel centerline and sheath temperatures for the CANFLEX bundle are lower by 388 and 128C, respectively, than those for the standard bundle because of the lower maximum linear power of the CANFLEX bundle. The pressure tube (PT)/calandria tube (CT) contact for the CANFLEX bundle occurs 2 s later than that for the standard bundle. The PT/CT contact temperature for the CANFLEX bundle is 7C lower than that for the standard bundle. These provide the CANFLEX bundle with a slightly enhanced safety margin for fuel channel integrity in the CANDU-6 reactor, compared with the standard bundle. The effect of bearing pad (BP)/PT contact on the PT temperature predictions is assessed. A BP/PT contact conductance of 3 kW/m{sup 2} {center_dot} K after PT ballooning does not create any hot spot because it gives the contacted PT sector approximately the same heat transfer as convective heating by the hotmore » coolant for the adjacent sector. The assumed BP/PT contact conductance does not threaten the fuel channel integrity.« less

Indirect Convertibility and Irving Fisher's Compensated Dollar

Advocates of the private issue of money by banks have proposed to solve the problem of the credibility of such an issue by having the banks commit themselves to redeeming their money in terms of a standard bundle of goods. Since it would be inconvenient for both the banks and their customers to deal with such bundles, the proposal has been made to have the redemption take place with an amount of gold actually worth, at prevailing market prices, as many standard bundles as the Unit denominations of the banknotes and deposits being redeemed (Yeager and Greenfield 1989, p. 410). This system ofindirect convertibility has frequently been described as similar to Irving Fisher's proposal for a compensated dollar (see, for example, ibid. pp. 418-19; Cowen and Krozner 1994, ch. 3; Dowd 1995). There is, indeed, a similarity in the fact that both schemes involve the use of gold and that the purpose of both is to maintain the purchasing power of money. Otherwise, however, there are basic differences between them. To begin with, changes in the price of gold in Fisher's proposal are not those determined in a free market, but changes in the monthly mint price at which the government stands ready to buy and sell unlimited quantities of gold: in particular, to (say) lower the mint price of gold (in Fisher's words, to increase the gold content of the dollar) if the price level should increase, and to raise the mint price if the price