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This book focuses on the practical application of statistical techniques for assessing measurement invariance with less emphasis on theoretical development or exposition. Instead, it describes the methods using a pedagogical framework followed by extensive illustrations that demonstrate how to use software to analyze real data. The chapters illustrate the practical methods to assess measurement invariance and shows how to apply them to a range of data. The computer syntax and data sets used in this book are available for download here: people.umass.edu/cswells.
The question of how to tax multinational companies that operate highly digitalised business models is one of the most contested areas of international taxation. The tax paid in the jurisdictions in which these companies operate has not kept pace with their immense growth and the OECD has proposed a new international tax compromise that will allocate taxing rights to market jurisdictions and remove the need to have a physical presence in the taxing jurisdictions in order to sustain taxability. In this work, Craig Elliffe explains the problems with the existing international tax system and its inability to respond to challenges posed by digitalised companies. In addition to looking at how the new international tax rules will work, Elliffe assesses their likely effectiveness and highlights features that are likely to endure in the next waves of international tax reform.
Optical tracking systems typically trade off between astrometric precision and field of view. In this work, we showcase a networked approach to optical tracking using very wide field-of-view imagers that have relatively low astrometric precision on the scheduled OSIRIS-REx slingshot manoeuvre around Earth on 22 Sep 2017. As part of a trajectory designed to get OSIRIS-REx to NEO 101955 Bennu, this flyby event was viewed from 13 remote sensors spread across Australia and New Zealand to promote triangulatable observations. Each observatory in this portable network was constructed to be as lightweight and portable as possible, with hardware based off the successful design of the Desert Fireball Network. Over a 4-h collection window, we gathered 15 439 images of the night sky in the predicted direction of the OSIRIS-REx spacecraft. Using a specially developed streak detection and orbit determination data pipeline, we detected 2 090 line-of-sight observations. Our fitted orbit was determined to be within about 10 km of orbital telemetry along the observed 109 262 km length of OSIRIS-REx trajectory, and thus demonstrating the impressive capability of a networked approach to Space Surveillance and Tracking.
Animal-derived dietary protein ingestion and physical activity stimulate myofibrillar protein synthesis rates in older adults. We determined whether a non-animal-derived diet can support daily myofibrillar protein synthesis rates to the same extent as an omnivorous diet. Nineteen healthy older adults (age 66±1 y; BMI 24±1 kg·m-2; m=12, f=7) participated in a randomised, parallel-group, controlled trial during which they consumed a 3-day isocaloric high-protein (1.8 g·kg body mass-1·d-1) diet, where the protein was provided from predominantly (71%) animal (OMNI; n=9; m=6, f=3) or exclusively vegan (VEG; n=10; m=6, f=4; mycoprotein providing 57% of daily protein intake) sources. During the dietary control period participants conducted a daily bout of unilateral resistance-type leg extension exercise. Prior to the dietary control period participants ingested 400 mL deuterated water, with 50 mL doses consumed daily thereafter. Saliva samples were collected throughout to determine body water deuterium (2H) enrichments, and muscle samples were collected from rested and exercised muscle to determine daily myofibrillar protein synthesis rates. Deuterated water dosing resulted in body water 2H enrichments of ~0.78±0.03%. Daily myofibrillar protein synthesis rates were 13±8 (P=0.169) and 12±4% (P=0.016) greater in the exercised compared with rested leg (1.59±0.12 vs 1.77±0.12 %·d-1 and 1.76±0.14 vs 1.93±0.12 %·d-1) in OMNI and VEG groups, respectively. Daily myofibrillar protein synthesis rates did not differ between OMNI and VEG in either rested or exercised muscle (P>0.05). Over the course of a three day intervention, omnivorous or vegan derived dietary protein sources can support equivalent rested and exercised daily myofibrillar protein synthesis rates in healthy older adults consuming a high-protein diet.
This study examined the differential impact of Hurricane Harvey on adolescent standardized Body Mass Index (zBMI), physical activity, diet, and perceived stress.
Prior to Hurricane Harvey, 175 ethnic minority adolescents were recruited from an independent school district in Houston. Height and weight were directly measured. The School Physical Activity and Nutrition Questionnaire assessed diet and physical activity. Stress was assessed with the Perceived Stress Scale. High hurricane impact was classified as at least 1 affirmative response to house damage, rescue, displacement, or going without food, water, or medicine. Repeated measures such as ANCOVA models were developed to assess differences in zBMI, physical activity, diet, and stress between the hurricane impact groups. Regression models were used to assess stress as a mediator of the hurricane impact and zBMI change relationship.
Students who were highly impacted by the hurricane had a greater decrease in zBMI than those less impacted from pre-hurricane to 15 weeks post-hurricane (95% CI 0.02 to 0.25, p<0.05). Physical activity and diet did not differ by impact. Perceived stress at 3 weeks post-hurricane mediated the impact and zBMI change relationship (β=-0.04 95% CI -0.12 to -0.002).
The decrease in zBMI among highly impacted students warrants further monitoring. Perceived stress, immediately following the hurricane, impacted student growth months later.
To describe nursing home staff experiences and perceptions of the factors that impact the sustainability of an antibiotic stewardship program (ASP).
Using a qualitative descriptive design, semistructured interviews with staff at 9 not-for-profit nursing homes with an established ASP were conducted and audio recorded. De-identified transcriptions of the interviews were coded using a sustainability framework and were analyzed to identify themes.
Interviews were conducted with 48 clinical and administrative staff to elicit their perceptions of the ASPs, and 7 themes were identified. ASPs were perceived to be resource intensive and “data driven,” requiring access to and interpretation of data that are not readily available at many nursing homes. Though motivated and committed, ASP champions felt that they could not single-handedly sustain the program. Attending to daily clinical needs (ie, “fires”) made it hard to progress beyond implementation and to reach step 2 of sustainability. Longstanding treatment habits by external prescribers and regulations were believed to impede ASP efforts. Partnerships with an external consultant with antibiotic stewardship expertise were considered important, as was the need for internal leadership support and collaboration across disciplinary boundaries. Participants felt that consistent and ongoing education on antibiotic stewardship at all staff levels was important.
Although many interconnected factors impact the sustainability of an ASP, nursing homes may be able to sustain an ASP by focusing on 3 critical areas: (1) explicit support by nursing home leadership, (2) external partnerships with professionals with antibiotic stewardship expertise and internal interprofessional collaborations, and (3) consistent education and training for all staff.
In this case study, we used point mapping data to evaluate long-term treatment of invasive tree-of-heaven (Ailanthus altissima). This study at the Buffalo National River included 21 project areas ranging in size from 0.02 to 11.3 ha and spanned five to eight years depending on the site. The control techniques varied depending on the year and included the application of herbicide, which also varied over the course of the study and included imazapyr, triclopyr, and triclopyr+fluroxypyr. Treatments during the first year reduced local A. altissima populations by an average of 66%. Long-term repeated treatments led to decreases of at least 90% in 70% of the project areas and at least 73% in 95% of the project areas. Only one project area was found to support no plants during the final treatment year. A. altissima increased at most project areas during an unusually wet year and was more likely to increase than decrease in intervals > 1 year with no treatment. Over the temporal and spatial scales of this case study, we observed high levels of control that will likely meet the specified levels and ecological benefits required in many similar efforts. Land managers must, however, make a long-term commitment of resources to achieve lasting control of this invasive species.
To evaluate the hypothesis that a perinatal educational dietary intervention focused on ‘eating for the gut microbiota’ improves diet quality of pregnant women pre- and postnatally.
The Healthy Parents, Healthy Kids study is a prospectively registered randomised controlled trial designed to evaluate the efficacy of a dietary intervention in altering the maternal and infant gut microbiota and improving perinatal diet quality. Eligible pregnant women were randomised to receive dietary advice from their healthcare provider or to additionally receive a three session dietary intervention. Dietary data were collected at gestation weeks 26, 31, 36 and postnatal week 4. Outcome measures were diet quality, dietary variety, prebiotic and probiotic food intakes, energy, fibre, saturated fat and discretionary food intakes. Between-group differential changes from baseline before and after birth in these dietary measures were assessed using generalised estimating equations.
Healthy pregnant women from gestation week 26.
Forty-five women were randomised (twenty-two control, twenty-three intervention). Compared with the control group, the intervention group improved diet quality prior to birth (5·66 (95 % CI 1·65, 9·67), Cohen’s d: 0·82 (se 0·33)). The intervention improved dietary variety (1·05 (95 % CI 0·17, 1·94), d: 0·66 (se 0·32)) and increased intakes of prebiotic (0·8 (95 % CI 0·27, 1·33), d: 0·91 (se 0·33)) and probiotic foods (1·05 (95 % CI 0·57, 1·53), d: 1·3(se 0·35)) over the whole study period compared with the control group.
A dietary intervention focused on ‘eating for the gut microbiota’ can improve aspects of perinatal diet quality during and after pregnancy.
Methicillin-resistant Staphylococcus aureus (MRSA) infection in neonates is associated with significant morbidity, mortality, and hospital cost. Multiple studies have shown that these infections are often preceded by colonization, but no consensus has been established for MRSA surveillance. The impact of changing the surveillance strategy on vancomycin utilization has not been evaluated previously. Methods: Retrospective chart review of infants who underwent MRSA screening in a level IV NICU with all outborn neonates. A weekly surveillance PCR was obtained from the nares between July 2016 and June 2017 (phase 1) and only on admission and discharge between July 2017 and June 2018 (phase 2). Patients with a positive PCR were placed on contact precautions without decolonization. The χ2 test was performed to compare the 2 phases of screening, and the Student t test and the Fisher exact test were used to compare the characteristics of MRSA colonized infants. Vancomycin utilization was measured in days of therapy (DOT) per 1,000 NICU patient days. Results: In total, 689 infants underwent MRSA screening during the study period; 324 infants had weekly MRSA surveillance and 365 infants had screening at admission and discharge. There was no statistically significant difference in MRSA colonization rates (4.3% vs 3.0%) or MRSA colonization acquisition (negative to positive, 1.8% vs 1.0%) between the phases. Among MRSA-colonized patients, nearly 60% were colonized on admission. Nearly 40% of the infants became colonized with MRSA during their hospitalization, none of whom developed MRSA infections prior to discharge. Mean vancomycin utilization decreased from 38.55 to 30.16 DOT per 1,000 NICU patient days between the 2 study periods. Conclusions: In a level IV NICU with relatively low MRSA prevalence, the change in MRSA screening practice from weekly surveillance to surveillance upon admission and discharge demonstrated no difference in MRSA acquisition or infection. Overall vancomycin utilization also decreased during this period, suggesting a culture shift around antibiotic utilization. Further study is needed to evaluate the utility of MRSA screening, decolonization, and isolation practices in low-prevalence NICUs and to identify additional drivers of vancomycin utilization.
Membership is central to the EU, as it is to any other international organisation. Withdrawal has assumed centre-stage through Brexit. While there is literature that is relevant to membership, most notably through academic discourse on differentiated integration, there is little more general inquiry concerning membership, the concept of which has importance and implications over and beyond more particular avenues of scholarship. This article examines the formal and substantive dimensions of membership and withdrawal in the EU.
The CDC recommends that consultant pharmacists support antimicrobial stewardship programs (ASPs) in long-term care facilities (LTCFs). We studied CDC-recommended ASP core elements implementation and antibiotic use in LTCFs before and after training consultant pharmacists. Methods: Between August 2017 and October 2017, consultant pharmacists from a regional long-term care pharmacy attended 5 didactic sessions preparing them to assist LTCFs in implementation of CDC-recommended ASP core elements. Training also included creating a process for evaluating appropriateness of all systemic antibiotics and providing prescriber feedback during their monthly mandatory drug-regimen reviews. Once monthly “meet-the-expert” sessions were held with consultant pharmacists throughout the project (November 2017 to December 2018). LTCF enrollment began in November 2017 and >90% of facilities joined by January 2018. After enrollment, consultant pharmacists initiated ASP interventions including antibiotic reviews and feedback using standard templates. They also held regular meetings with infection preventionists to discuss Core Elements implementation and provided various ASP resources to LTCFs (eg, antibiotic policy template, guidance documents and standard assessment and communication tools). Data collection included ASP Core Elements, antibiotic starts, days of therapy (DOT), and resident days (RD). The McNemar test, the Wilcoxon signed-rank test, generalized estimating equation model, and the classic repeated measures approach were used to compare the presence of all 7 core elements and antibiotic use during the baseline (2017) and intervention (2018) year.Results: In total, 9 trained consultant pharmacists assisted 32 LTCFs with ASP implementation. When evaluating 27 LTCFs that provided complete data, a significant increase in presence of all 7 Core Elements after the intervention was noted compared to baseline (67% vs 0; median Core Elements, 7 vs 2; range, 6–7 vs 1–6; P < .001). Median monthly antibiotic starts per 1,000 RD and DOT per 1,000 RD decreased in 2018 compared to 2017: 8.93 versus 9.91 (P < .01) and 106.47 versus 141.59 (P < .001), respectively. However, variations in antibiotic use were detected among facilities (Table 1). When comparing trends, antibiotic starts and DOT were already trending downward during 2017 (Fig. 1A and 1B). On average, antibiotic starts decreased by 0.27 per 1,000 RD (P < .001) and DOT by 1.92 per 1,000 RD (P < .001) each month during 2017. Although antibiotic starts remained mostly stable in 2018, DOT continued to decline further (average monthly decline, 2.60 per 1,000 RD; P < .001). When analyzing aggregated mean, antibiotic use across all sites per month by year, DOT were consistently lower throughout 2018 and antibiotic starts were lower for the first 9 months (Fig. 1C and 1D). Conclusions: Consultant pharmacists can play an important role in strengthening ASPs and in decreasing antibiotic use in LTCFs. Educational programs should be developed nationally to train long-term care consultant pharmacists in ASP implementation.
Funding: Merck & Co., Inc, provided funding for this study.
Disclosures: Muhammad Salman Ashraf and Scott Bergman report receipt of a research grant from Merck.
The study of the sixteenth-century merchant fleet of England, Wales, and the Channel Islands is a neglected area of research in comparison to the volume of work undertaken into trade, the development of the Royal Navy, the age of exploration, privateering, great personalities, ship design, and naval warfare. The only major book-length study of English merchant shipping in this period – focusing upon the ships themselves rather than trade routes, commodities, and mercantile communities – is Dorothy Burwash's English Merchant Shipping, 1460-1540, which is now over seventy years old, and research into Welsh and Channel Islands shipping is similarly scant.2 This lack of research into the size and geographical distribution of the merchant fleet is unfortunate, because shipping was central to the economic lifeblood of the nation. Goods were imported and exported to and from Europe (and increasingly as the sixteenth century progressed from further afield), and whilst foreign shipping contributed to this overseas trade, by the sixteenth century at least it was indigenous shipping which bore the brunt of this mercantile activity in most ports. Merchant vessels were also essential to native trade, moving commodities coastwise and navigating the extensive Anglo-Welsh riverine networks to transport goods to and from hundreds of settlements both on the coast and much further inland. Fishing vessels, which were also employed as trading vessels on occasion, were also an essential part of the economy.
What is more, these vessels were of considerable political interest. The English Crown (which had suzerainty over Wales and the Channel Islands) had the prerogative right to tax overseas trade (imports and exports) on certain commodities carried in both native and foreign vessels, and the government thus had a vested financial interest in monitoring the activities of the merchant fleet. In short, an understanding of the merchant fleet of England, Wales, and the Channel Islands opens an important window into the country's economy. The Crown was also interested in the size and tonnage of the fleet because it was able to requisition or hire merchantmen for naval duties: knowing how many ships existed, how large they were, and where they were located (their home ports) was vital information.
Background: Catheter-associated urinary tract infections (CAUTIs) are a common hospital-acquired infection (HAI) resulting in excess morbidity, mortality, and cost. Urine management can be a challenging issue, particularly in women, due to limited options for control of urinary incontinence. Issues with urinary leakage and worry for subsequent skin break down often leads to indwelling catheter insertion. In the spring of 2018, our facility implemented a female external urine collection device (EUCD) in efforts to decrease catheter days and to limit CAUTIs. Methods: Retrospective, 32-month (January 2017–August 2019), quasi-experimental, before-and-after study. Catheter use and CAUTI were defined according to CDC NHSN criteria. Poisson regression was used to model the rate of CAUTI (per 1,000 patient days [PD] and per 1,000 catheter days [CD]) comparing the 14 months prior to EUCD introduction with the 14 months after introduction and allowing a 3-month introduction period. Results: The CAUTI rate did not change significantly. The overall CAUTI rate per 1,000 PD decreased slightly from 0.24 to 0.20 (P = 0.44; model risk, 0.86; 95% CI, 0.58–1.26) whereas the rate per 1,000 CD increased slightly 1.5 to 1.6 (P = 0.76; model risk, 1.06; 95% CI, 0.73-–1.56). The CAUTI rate for men increased from 0.09 to 0.11 per 1,000 PD (P = 0.42; model risk, 1.29) and from 0.99 to 1.55 per 1,000 CD (P = 0.17; model risk, 1.56). For women, the rate of CAUTI decreased from 0.15 to 0.09 per 1,000 PD (P = 0.10; model risk, 0.61) and from 2.12 to 1.65 per 1,000 CD (P = 0.38; model risk, 0.38). A significant decrease in catheter days (CD per 1,000 PD; P < .0001) was observed for all hospitalized patients (from 158.56 to 128.3; model risk, 0.81), for men (from 87.06 to 72.15; model risk, 0.83), and for women (from 71.49 to 56.15; model risk, 0.79). Of 2,347 adverse events, 5 (0.2%) involved perineal skin breakdown and redness. Three events were related to malposition of the ECUD or inappropriate level of suction and 1 event was related to latex allergy and EUCD use. Conclusions: The introduction of a EUCD for women was associated with a significant decrease in indwelling catheter usage. A trend toward a decrease in CAUTI per 1,000 PD for women was observed (P = .10). Additional studies on whether the EUCD is associated with changes in UTI rates (both CAUTIs and noncatheter UTIs) as well as cost implications of EUCD are warranted.
Background: A penicillin allergy guidance document containing an algorithm for challenging penicillin allergic patients with β-lactams was developed by the antimicrobial stewardship program (ASP). As part of this algorithm, a “graded challenge” order set was created containing antimicrobial orders and safety medications along with monitoring instructions. The process is designed to challenge patients at low risk of reaction with infusions of 1% of the target dose, then 10%, and finally the full dose, each 30 minutes apart. We evaluated outcomes from the order set. Methods: Orders of the graded challenge over 17 months (March 2018 through July 2019) were reviewed retrospectively. Data were collected on ordering and outcomes of the challenges and allergy documentation. Use was evaluated based on ASP-recommended indications: history of IgE-mediated or unknown reaction plus (1) no previous β-lactam tolerance and the reaction occurred >10 years ago, or (2) previous β-lactam tolerance, now requiring a different β-lactam for treatment. Only administered challenges were included and descriptive statistics were utilized. Results: Of 67 orders, 57 graded challenges were administered to 56 patients. The most common allergies were penicillins (87.7%) and cephalosporins (38.6%), with the most common reactions being unknown (41.7%) or hives (22%). The most common antibiotics challenged were ceftriaxone (43.9%), cefepime (21.1%), and cefazolin (5.3%). Antibiotics given prior to challenge included vancomycin (48.2%), fluoroquinolones (35.7%), carbapenems (21.4%), aztreonam (19.6%), and clindamycin (12.5%). The median duration of challenged antibiotic was 6 days. The infectious diseases service was consulted on 59.6% of challenges and 75.4% of challenges were administered in non-ICU settings. There was 1 reaction (1.8%) involving a rash with the second infusion, which was treated with oral diphenhydramine and had no lasting effects. Based on indications, 80.7% of challenges were aligned with ASP guidance criteria. The most common use outside of these criteria was in patients without IgE-mediated reactions (10.5%). Most of these had minor rashes and could have received a full dose of a cephalosporin. Allergy information was updated in the electronic health record after 91.2% of challenges. Conclusions: We demonstrated the utility of a graded challenge process at our academic medical center. It was well tolerated, ordered frequently by noninfectious diseases clinicians, administered primarily in non-ICU settings, and regularly resulted in updated allergy information in the medical record. With many patients initially receiving broad-spectrum antibiotics with high costs or increased rates of adverse effects, graded challenges can potentially prevent the use of suboptimal therapies with minimal time and resource investment.
Disclosures: Scott Bergman reports a research grant from Merck.
We develop a deep autoencoder architecture that can be used to find a coordinate transformation which turns a non-linear partial differential equation (PDE) into a linear PDE. Our architecture is motivated by the linearising transformations provided by the Cole–Hopf transform for Burgers’ equation and the inverse scattering transform for completely integrable PDEs. By leveraging a residual network architecture, a near-identity transformation can be exploited to encode intrinsic coordinates in which the dynamics are linear. The resulting dynamics are given by a Koopman operator matrix K. The decoder allows us to transform back to the original coordinates as well. Multiple time step prediction can be performed by repeated multiplication by the matrix K in the intrinsic coordinates. We demonstrate our method on a number of examples, including the heat equation and Burgers’ equation, as well as the substantially more challenging Kuramoto–Sivashinsky equation, showing that our method provides a robust architecture for discovering linearising transforms for non-linear PDEs.
In Europe, the incidence of psychotic disorder is high in certain migrant and minority ethnic groups (hence: ‘minorities’). However, it is unknown how the incidence pattern for these groups varies within this continent. Our objective was to compare, across sites in France, Italy, Spain, the UK and the Netherlands, the incidence rates for minorities and the incidence rate ratios (IRRs, minorities v. the local reference population).
The European Network of National Schizophrenia Networks Studying Gene–Environment Interactions (EU-GEI) study was conducted between 2010 and 2015. We analyzed data on incident cases of non-organic psychosis (International Classification of Diseases, 10th edition, codes F20–F33) from 13 sites.
The standardized incidence rates for minorities, combined into one category, varied from 12.2 in Valencia to 82.5 per 100 000 in Paris. These rates were generally high at sites with high rates for the reference population, and low at sites with low rates for the reference population. IRRs for minorities (combined into one category) varied from 0.70 (95% CI 0.32–1.53) in Valencia to 2.47 (95% CI 1.66–3.69) in Paris (test for interaction: p = 0.031). At most sites, IRRs were higher for persons from non-Western countries than for those from Western countries, with the highest IRRs for individuals from sub-Saharan Africa (adjusted IRR = 3.23, 95% CI 2.66–3.93).
Incidence rates vary by region of origin, region of destination and their combination. This suggests that they are strongly influenced by the social context.