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One might not expect to find eleven immaculately painted plaster chicken heads in a museum of the history of science such as the Whipple Museum. The heads were made in the early 1930s and have been attributed to Reginald Punnett, Alfred Balfour Professor of Genetics at the University of Cambridge from 1912 to 1940. During his long career, Balfour conducted detailed breeding experiments with chickens, experiments that are themselves bound up with the invention for which he is best known today, the Punnett square, a tabular array still used in genetics to represent the outcome of a cross between two organisms. In this chapter, I investigate how both Punnett’s square and his chicken head models, qua visualisations, played different but related roles in the study and teaching of Mendelian genetics and heredity during this crucial period in the development of genetics in Britain. In so doing, I demonstrate that models and their uses in science are most clearly illuminated when their relations to and differences from other forms of visual media, including flat material such as the Punnett square, are made clear.
Sintered nanoparticle structures are macroscopically brittle but quite robust if deposited on a flexible substrate. The effects of a polymer substrate on the stretchability of both brittle and ductile coatings and traces are well established. Systematic effects of substrate properties on the fatigue resistance of aerosol printed nano-Ag are slightly more complex. The present work is focused on the early stages of fatigue, where the resistance increases significantly but cracks are not yet visible. Overall, the fatigue behavior is seen to vary with the combination of substrate modulus and viscoelastic deformation properties. Comparing two common polyimides, the rate of damage was seen to increase faster with increasing amplitude on the less compliant one. Consistently with this increasing the minimum strain in the cycle led to a significantly stronger reduction in damage rates. However, the damage rate remained lower on the less compliant substrate at all amplitudes and strain ranges of practical concern.
Assertive bargaining occurs from time to time in the US Congress. It became an important feature of legislative negotiations within the House Republican Party when, following the 2014 elections, a group of organized conservatives called the House Freedom Caucus regularly issued threats against its own party's leadership. Such behavior by an ideologically extreme bloc of lawmakers is not accounted for by existing theories of legislative politics. This Element posits explanations for why such threat-making might occur and what might increase its likelihood of success, then tests those explanations using the Freedom Caucus as a case study.
Prior research into the liquid-phase exfoliation of graphite to produce few-layer graphene has focused primarily on the surface energy matching between graphite and solvent; however, the effect of other solvent properties, such as liquid viscosity, have not been systematically explored. In principle, a higher viscosity solvent should enable the production of graphene and other graphitic nanomaterials by liquid-phase exfoliation at lower shear rates than traditionally used organic solvents of low viscosity, such as N-methyl-2-pyrrolidone (NMP). Thus, at a given shear rate, more material should be exfoliated in the higher viscosity solvent. Hence, graphite suspensions in NMP, benzyl benzoate, and propylene glycol were exfoliated at various shear rates in a rheometer. Exfoliant concentrations were measured by ultraviolet- visual (UV-vis) spectroscopy and quality characterization was performed by Raman spectroscopy and scanning electron microscopy (SEM). Graphite exfoliation in the more viscous propylene glycol solvent resulted in a higher exfoliant concentration than in the less viscous NMP and benzyl benzoate solvents across all shear rates. Benzyl benzoate lowered exfoliant levels, likely due to a poor surface energy match, resulting in particle attraction and aggregation. Characterization showed that at least some of our material is few-layer graphene.
Ventilator bundles encompass practices that reduce the risk of ventilator complications, including ventilator-associated pneumonia. The impact of ventilator bundles on the risk of developing ventilator-associated events (VAEs) is unknown. We sought to determine whether decreased compliance to the ventilator bundle increases the risk for VAE development.
Nested case-control study.
This study was conducted at 6 adult intensive care units at an academic tertiary-care center in Tennessee.
In total, 273 patients with VAEs were randomly matched in a 1:4 ratio to controls by mechanical ventilation duration and ICU type.
Controls were selected from the primary study population at risk for a VAE after being mechanically ventilated for the same number of days as a specified case. Using conditional logistic regression analysis, overall cumulative compliance, and compliance with individual components of the bundle in the 3 and 7 days prior to VAE development (or the control match day) were examined.
Overall bundle compliance at 3 days (odds ratio [OR], 1.15; P=.34) and 7 days prior to VAE diagnosis (OR, 0.96; P=.83) were not associated with VAE development. This finding did not change when limiting the outcome to infection-related ventilator-associated complications (IVACs) and after adjusting for age and gender. In the examination of compliance with specific bundle components increased compliance with chlorhexidine oral care was associated with increased risk of VAE development in all analyses.
Ventilator bundle compliance was not associated with a reduced risk for VAEs. Higher compliance with chlorhexidine oral care was associated with a greater risk for VAE development.
OBJECTIVES/SPECIFIC AIMS: To create a searchable public registry of all Quality Improvement (QI) projects. To incentivize the medical professionals at UF Health to initiate quality improvement projects by reducing startup burden and providing a path to publishing results. To reduce the review effort performed by the internal review board on projects that are quality improvement Versus research. To foster publication of completed quality improvement projects. To assist the UF Health Sebastian Ferrero Office of Clinical Quality & Patient Safety in managing quality improvement across the hospital system. METHODS/STUDY POPULATION: This project used a variant of the spiral software development model and principles from the ADDIE instructional design process for the creation of a registry that is web based. To understand the current registration process and management of quality projects in the UF Health system a needs assessment was performed with the UF Health Sebastian Ferrero Office of Clinical Quality & Patient Safety to gather project requirements. Biweekly meetings were held between the Quality Improvement office and the Clinical and Translational Science – Informatics and Technology teams during the entire project. Our primary goal was to collect just enough information to answer the basic questions of who is doing which QI project, what department are they from, what are the most basic details about the type of project and who is involved. We also wanted to create incentive in the user group to try to find an existing project to join or to commit the details of their proposed new project to a data registry for others to find to reduce the amount of duplicate QI projects. We created a series of design templates for further customization and feature discovery. We then proceed with the development of the registry using a Python web development framework called Django, which is a technology that powers Pinterest and the Washington Post Web sites. The application is broken down into 2 main components (i) data input, where information is collected from clinical staff, Nurses, Pharmacists, Residents, and Doctors on what quality improvement projects they intend to complete and (ii) project registry, where completed or “registered” projects can be viewed and searched publicly. The registry consists of a quality investigator profile that lists contact information, expertise, and areas of interest. A dashboard allows for the creation and review of quality improvement projects. A search function enables certain quality project details to be publicly accessible to encourage collaboration. We developed the Registry Matching Algorithm which is based on the Jaccard similarity coefficient that uses quality project features to find similar quality projects. The algorithm allows for quality investigators to find existing or previous quality improvement projects to encourage collaboration and to reduce repeat projects. We also developed the QIPR Approver Algorithm that guides the investigator through a series of questions that allows an appropriate quality project to get approved to start without the need for human intervention. RESULTS/ANTICIPATED RESULTS: A product of this project is an open source software package that is freely available on GitHub for distribution to other health systems under the Apache 2.0 open source license. Adoption of the Quality Improvement Project Registry and promotion of it to the intended audience are important factors for the success of this registry. Thanks goes to the UW-Madison and their QI/Program Evaluation Self-Certification Tool (https://uwmadison.co1.qualtrics.com/SE/?SID=SV_3lVeNuKe8FhKc73) used as example and inspiration for this project. DISCUSSION/SIGNIFICANCE OF IMPACT: This registry was created to help understand the impact of improved management of quality projects in a hospital system. The ultimate result will be to reduce time to approve quality improvement projects, increase collaboration across the UF Health Hospital system, reduce redundancy of quality improvement projects and translate more projects into publications.
To examine variation in antibiotic coverage and detection of resistant pathogens in community-onset pneumonia.
A total of 128 hospitals in the Veterans Affairs health system.
Hospitalizations with a principal diagnosis of pneumonia from 2009 through 2010.
We examined proportions of hospitalizations with empiric antibiotic coverage for methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa (PAER) and with initial detection in blood or respiratory cultures. We compared lowest- versus highest-decile hospitals, and we estimated adjusted probabilities (AP) for patient- and hospital-level factors predicting coverage and detection using hierarchical regression modeling.
Among 38,473 hospitalizations, empiric coverage varied widely across hospitals (MRSA lowest vs highest, 8.2% vs 42.0%; PAER lowest vs highest, 13.9% vs 44.4%). Detection rates also varied (MRSA lowest vs highest, 0.5% vs 3.6%; PAER lowest vs highest, 0.6% vs 3.7%). Whereas coverage was greatest among patients with recent hospitalizations (AP for anti-MRSA, 54%; AP for anti-PAER, 59%) and long-term care (AP for anti-MRSA, 60%; AP for anti-PAER, 66%), detection was greatest in patients with a previous history of a positive culture (AP for MRSA, 7.9%; AP for PAER, 11.9%) and in hospitals with a high prevalence of the organism in pneumonia (AP for MRSA, 3.9%; AP for PAER, 3.2%). Low hospital complexity and rural setting were strong negative predictors of coverage but not of detection.
Hospitals demonstrated widespread variation in both coverage and detection of MRSA and PAER, but probability of coverage correlated poorly with probability of detection. Factors associated with empiric coverage (eg, healthcare exposure) were different from those associated with detection (eg, microbiology history). Providing microbiology data during empiric antibiotic decision making could better align coverage to risk for resistant pathogens and could promote more judicious use of broad-spectrum antibiotics.
The CMP challenges for advanced technology nodes are discussed. Global and local uniformity challenges and their cumulative effects are presented. Uniformity improvements for advanced node integration were achieved through slurry, pad and platen optimization, innovative integration schemes, the reduction of incoming variation and the reduction of cumulative effects. We discuss reduction of typical CMP defect types. Defects resulting from simple mechanisms (foreign material, polish residues) and those resulting from chemical and physical interactions (corrosion, chemical attack, scratches, physical migration) and strategies for control are studied. Defectivity reduction measures include new post-CMP clean chemicals, new slurries and pads and reduction of incoming defectivity. Finally we discuss an observed tradeoff between good defectivity and good uniformity.
Trauma systems have been widely implemented across Canada, but access to trauma care remains a challenge for much of the population. This study aims to develop and validate a model to quantify the accessibility of definitive care within one provincial trauma system and identify populations with poor access to trauma care.
A geographic information system (GIS) was used to generate models of pre-scene and post-scene intervals, respectively. Models were validated using a population-based trauma registry containing data on prehospital time intervals and injury locations for Nova Scotia (NS). Validated models were then applied to describe the population-level accessibility of trauma care for the NS population as well as a cohort of patients injured in motor vehicle collisions (MVCs).
Predicted post-scene intervals were found to be highly correlated with documented post-scene intervals (β 1.05, p<0.001). Using the model, it was found that 88.1% and 42.7% of the population had access to Level III and Level I trauma care within 60 minutes of prehospital time from their residence, respectively. Access for victims of MVCs was lower, with 84.3% and 29.7% of the cohort having access to Level III and Level I trauma care within 60 minutes of the location of injury, respectively.
GIS models can be used to identify populations with poor access to care and inform service planning in Canada. Although only 43% of the provincial population has access to Level I care within 60 minutes, the majority of the population of NS has access to Level III trauma care.
To determine the source of a healthcare-associated outbreak of Pantoea agglomerans bloodstream infections.
Epidemiologic investigation of the outbreak.
Oncology clinic (clinic A).
Cases were defined as Pantoea isolation from blood or catheter tip cultures of clinic A patients during July 2012–May 2013. Clinic A medical charts and laboratory records were reviewed; infection prevention practices and the facility’s water system were evaluated. Environmental samples were collected for culture. Clinical and environmental P. agglomerans isolates were compared using pulsed-field gel electrophoresis.
Twelve cases were identified; median (range) age was 65 (41–78) years. All patients had malignant tumors and had received infusions at clinic A. Deficiencies in parenteral medication preparation and handling were identified (eg, placing infusates near sinks with potential for splash-back contamination). Facility inspection revealed substantial dead-end water piping and inadequate chlorine residual in tap water from multiple sinks, including the pharmacy clean room sink. P. agglomerans was isolated from composite surface swabs of 7 sinks and an ice machine; the pharmacy clean room sink isolate was indistinguishable by pulsed-field gel electrophoresis from 7 of 9 available patient isolates.
Exposure of locally prepared infusates to a contaminated pharmacy sink caused the outbreak. Improvements in parenteral medication preparation, including moving chemotherapy preparation offsite, along with terminal sink cleaning and water system remediation ended the outbreak. Greater awareness of recommended medication preparation and handling practices as well as further efforts to better define the contribution of contaminated sinks and plumbing deficiencies to healthcare-associated infections are needed.
While there is a substantial literature highlighting the presence of social dynamics in legislatures, we know very little about the precise processes that generate these social dynamics. Yet, whether social dynamics are due to peer pressure, frequency of interaction, or genuine learning, for example, has important implications for questions of political representation and accountability. We demonstrate how a recent innovation can be used to study the diffusion of behavior within legislatures. In particular, we study diffusion within the US House of Representatives by looking at the dynamic process underlying discharge petitions. The discharge procedure shares many characteristics with other forms of legislative behavior, yet it has one important advantage when it comes to studying social dynamics: we can observe when members decide to sign petitions. Based on data from 1995 to 2014, we find that the social dynamics underlying the discharge procedure tend to involve the rational evaluation of information conveyed by the behavior of previous petition signatories.
It is necessary to calculate location-specific marine ΔR values in order to calibrate marine samples using calibration curves such as those provided through the IntCal98 (Stuiver et al. 1998) data. Where known-age samples are available, this calculation is straightforward (i.e. Stuiver et al. 1986). In the case that a paired marine/terrestrial sample calculation is performed, however, the standard calculation (i.e. Stuiver and Braziunas 1993) requires that the samples are treated as relating to isochronous events. This may not be an appropriate assumption for many archaeological paired samples. In this paper, we present an approach to calculating marine ΔR values that does not require the dated events to be treated as isochronous. When archaeological evidence allows the dated events to be tightly temporally constrained, the approach presented here and that described by Stuiver and Braziunas (1993) give very similar results. However, where tight temporal constraints are less certain, the 2 approaches can give rise to differing results. The example analysis considered here shows that a ΔR of −81 ± 64 14C yr is appropriate for samples in the vicinity of Nenumbo (Reef Islands, southeast Solomon Islands) around the period 2000–3000 BP.
Hospital-acquired infections (HAIs) develop rapidly after brief and transient exposures, and ecological exposures are central to their etiology. However, many studies of HAIs risk do not correctly account for the timing of outcomes relative to exposures, and they ignore ecological factors. We aimed to describe statistical practice in the most cited HAI literature as it relates to these issues, and to demonstrate how to implement models that can be used to account for them.
We conducted a literature search to identify 8 frequently cited articles having primary outcomes that were incident HAIs, were based on individual-level data, and used multivariate statistical methods. Next, using an inpatient cohort of incident Clostridium difficile infection (CDI), we compared 3 valid strategies for assessing risk factors for incident infection: a cohort study with time-fixed exposures, a cohort study with time-varying exposures, and a case-control study with time-varying exposures.
Of the 8 studies identified in the literature scan, 3 did not adjust for time-at-risk, 6 did not assess the timing of exposures in a time-window prior to outcome ascertainment, 6 did not include ecological covariates, and 6 did not account for the clustering of outcomes in time and space. Our 3 modeling strategies yielded similar risk-factor estimates for CDI risk.
Several common statistical methods can be used to augment standard regression methods to improve the identification of HAI risk factors.
Infect. Control Hosp. Epidemiol. 2016;37(4):411–419
Disorganized attachment is an important early risk factor for socioemotional problems throughout childhood and into adulthood. Prevailing models of the etiology of disorganized attachment emphasize the role of highly dysfunctional parenting, to the exclusion of complex models examining the interplay of child and parental factors. Decades of research have established that extreme child birth weight may have long-term effects on developmental processes. These effects are typically negative, but this is not always the case. Recent studies have also identified the dopamine D4 receptor (DRD4) as a moderator of childrearing effects on the development of disorganized attachment. However, there are inconsistent findings concerning which variant of the polymorphism (seven-repeat long-form allele or non–seven-repeat short-form allele) is most likely to interact with caregiving in predicting disorganized versus organized attachment. In this study, we examined possible two- and three-way interactions and child DRD4 polymorphisms and birth weight and maternal caregiving at age 6 months in longitudinally predicting attachment disorganization at 36 months. Our sample is from the Maternal Adversity, Vulnerability and Neurodevelopment project, a sample of 650 mother–child dyads. Birth weight was cross-referenced with normative data to calculate birth weight percentile. Infant DRD4 was obtained with buccal swabs and categorized according to the presence of the putative allele seven repeat. Macroanalytic and microanalytic measures of maternal behavior were extracted from a videotaped session of 20 min of nonfeeding interaction followed by a 10-min divided attention maternal task at 6 months. Attachment was assessed at 36 months using the Strange Situation procedure, and categorized into disorganized attachment and others. The results indicated that a main effect for DRD4 and a two-way interaction of birth weight and 6-month maternal attention (frequency of maternal looking away behavior) and sensitivity predicted disorganized attachment in robust logistic regression models adjusted for social demographic covariates. Specifically, children in the midrange of birth weight were more likely to develop a disorganized attachment when exposed to less attentive maternal care. However, the association reversed with extreme birth weight (low and high). The DRD4 seven-repeat allele was associated with less disorganized attachment (protective), while non–seven-repeat children were more likely to be classified as disorganized attachment. The implications for understanding inconsistencies in the literature about which DRD4 genotype is the risk direction are also considered. Suggestions for intervention with families with infants at different levels of biological risk and caregiving risk are also discussed.
Standard estimates of the impact of Clostridium difficile infections (CDI) on inpatient lengths of stay (LOS) may overstate inpatient care costs attributable to CDI. In this study, we used multistate modeling (MSM) of CDI timing to reduce bias in estimates of excess LOS.
A retrospective cohort study of all hospitalizations at any of 120 acute care facilities within the US Department of Veterans Affairs (VA) between 2005 and 2012 was conducted. We estimated the excess LOS attributable to CDI using an MSM to address time-dependent bias. Bootstrapping was used to generate 95% confidence intervals (CI). These estimates were compared to unadjusted differences in mean LOS for hospitalizations with and without CDI.
During the study period, there were 3.96 million hospitalizations and 43,540 CDIs. A comparison of unadjusted means suggested an excess LOS of 14.0 days (19.4 vs 5.4 days). In contrast, the MSM estimated an attributable LOS of only 2.27 days (95% CI, 2.14–2.40). The excess LOS for mild-to-moderate CDI was 0.75 days (95% CI, 0.59–0.89), and for severe CDI, it was 4.11 days (95% CI, 3.90–4.32). Substantial variation across the Veteran Integrated Services Networks (VISN) was observed.
CDI significantly contributes to LOS, but the magnitude of its estimated impact is smaller when methods are used that account for the time-varying nature of infection. The greatest impact on LOS occurred among patients with severe CDI. Significant geographic variability was observed. MSM is a useful tool for obtaining more accurate estimates of the inpatient care costs of CDI.
Infect. Control Hosp. Epidemiol. 2015;36(9):1024–1030
This year alone has seen outbreaks of epidemics such as Ebola, Chikungunya, and many other emerging infectious diseases (EIDs). We must look to the responses of recent outbreaks to help guide our strategies in current and future outbreaks or we risk repeating the same mistakes. The objective of this paper was to conduct a systematic literature review of the methodology used by studies that examined EID communication during the 2009 H1N1 pandemic outbreak through different communication channels or by analyzing contents and strategies.
This was a systematic review of the literature (n=61) studying risk communication strategies of H1N1 influenza, published between 2009 and 2013, and retrieved from searches of computerized databases, hand searches, and authoritative texts by use of specific search criteria. Searches were followed by review, categorization, and mixed qualitative and quantitative content analysis.
Of 41 articles that used quantitative methods, most used surveys (n=35); some employed content analyses (n=4) and controlled trials (n=2). The 16 articles that employed qualitative methods relied on content analyses (n=10), semi-structured interviews (n=2) and focus groups (n=4). Four more articles used mixed-methods or nonstandard methods. Seven different topic categories were found: risk perception and effects on behaviors, framing the risk in the media, public concerns, trust, optimistic bias, uncertainty, and evaluating risk communication.
Up until 2013, studies tended to be descriptive and quantitative rather than discursive and qualitative and to focus on the role of the media as representing information and not as a medium for actual communication with the public. Several studies from 2012, and increasingly more in 2013, addressed issues of discourse and framing and the complexity of risk communication with the public. Formative evaluations that use recommendations from past research when designing communication campaigns from the first stages of crises are recommended. Research should employ diverse triangulation processes based on representatives from different stakeholders. Further studies should address the potential offered by social media to create dialogue with individuals and the public at large. (Disaster Med Public Health Preparedness. 2015;9:199-206)