361 research outputs found

    Efficient markets: land and slave prices in Henrico County, Virginia, 1782-1863

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    Asset market efficiency fosters rational decisions on allocating resources, both individually and socially, and thus helps determine individuals' wealth accumulation and nations' economic growth. To date, however, there are little systematic data available for, and even less analysis of, US capital markets during the late eighteenth and mid-nineteenth centuries, a period of great transformation and growth. This paper is a preliminary exploration of market efficiency in two early US asset markets, looking at prices of land and slaves in Henrico County, Virginia, from the 1780s to the 1860s. Our hypothesis tests on both the price of and returns to Henrico County land and slaves provide evidence that land and slave markets in late eighteenth and early nineteenth century US were weak-form efficient, suggesting that available information was quickly and fully incorporated into prices in these early North American asset markets.efficient markets, random walk, Dickey-Fuller, KPSS test, slave prices, land prices

    Report on faculty and student evaluation of instructors in direct service teaching at Portland State University Graduate School of Social Work

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    The classroom as a messenger of learning and awareness is an honored institution. Education promotes the spirit of inquiry. Concurrently, inquiry spearheads research. As students who have spent many hours in a classroom, we have wondered, inquired, into the spirit of the classroom. Our research is devoted to gaining and establishing a series of perspectives as to what occurs in the classroom. Our research is concerned with specific characteristics of the teacher-learner relationship and outcomes of that relationship. Specific characteristics of the student-teacher relationship such as effective communication, clarity of course objectives, or the quality of class lectures, have been explored by the use of an evaluative tool. Outcomes of the teacher-learner relationship such as the achievement of course objectives, and their relevance to Direct Services were also explored. As students in the School of Social Work, we saw dearth of communication between students and their respective professors. By assessing the relative successes of Direct Service Methods classes, and by the processes that are necessary for assessment, we hope to serve students and those who teach them

    Political connections and their effects on capital investment, legislation, and consumer and worker safety: evidence from Victorian railways

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    The political connections of businesses bear implications for the economy. This dissertation studies the political connection of railways in the United Kingdom during the 19th century using several novel data sets. The first chapter of the dissertation begins by quantitatively investigating the implications of the political connections of railways for capital investment. Politically connected railways did significantly more capital investment than their non-connected counterparts. In addition, within-firm increases in political connections were associated with increased subsequent capital investment. The latter part of chapter one introduces the private bill process in the legislature as a likely channel relating political connections and capital investment. Politically connected firms proposed and passed considerably more legislation enabling capital investment than non-politically connected firms. Chapter two of the dissertation focuses on consumer and employee safety, relating safety to political connections and showing that politically connected railways were considerably deadlier than non-politically connected railways. A century of fatal railway accidents data is presented along with supplementary data sources to demonstrate this point. Chapter three of the dissertation looks at political connections as the outcome rather than as the explanatory variable. Political connections are related to voting rights in U.K. constituencies across five general elections spanning major franchise reforms. Within-constituency results show that for a given constituency increases in the franchise are associated with decreased likelihood that railway directors will run or win seats in the House of Commons

    Overlapping functionality of the Pht proteins in zinc homeostasis of streptococcus pneumoniae

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    Streptococcus pneumoniae is a globally significant pathogen that causes a range of diseases, including pneumonia, sepsis, meningitis, and otitis media. Its ability to cause disease depends upon the acquisition of nutrients from its environment, including transition metal ions such as zinc. The pneumococcus employs a number of surface proteins to achieve this, among which are four highly similar polyhistidine triad (Pht) proteins. It has previously been established that these proteins collectively aid in the delivery of zinc to the ABC transporter substrate-binding protein AdcAII. Here we have investigated the contribution of each individual Pht protein to pneumococcal zinc homeostasis by analyzing mutant strains expressing only one of the four pht genes. Under conditions of low zinc availability, each of these mutants showed superior growth and zinc accumulation profiles relative to a mutant strain lacking all four genes, indicating that any of the four Pht proteins are able to facilitate delivery of zinc to AdcAII. However, optimal growth and zinc accumulation in vitro and pneumococcal survival and proliferation in vivo required production of all four Pht proteins, indicating that, despite their overlapping functionality, the proteins are not dispensable without incurring a fitness cost. We also show that surface-attached forms of the Pht proteins are required for zinc recruitment and that they do not contribute to defense against extracellular zinc stress

    The first histidine triad motif of phtd is critical for zinc homeostasis in Streptococcus pneumoniae

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    Streptococcus pneumoniae is the world's foremost human pathogen. Acquisition of the first row transition metal ion zinc is essential for pneumococcal colonization and disease. Zinc is acquired via the ATP-binding cassette transporter AdcCB and two zinc-binding proteins, AdcA and AdcAII. We have previously shown that AdcAII is reliant upon the polyhistidine triad (Pht) proteins to aid in zinc recruitment. Pht proteins generally contain five histidine (His) triad motifs that are believed to facilitate zinc binding and therefore play a significant role in pneumococcal metal ion homeostasis. However, the importance and potential redundancy of these motifs have not been addressed. We examined the effects of mutating each of the five His triad motifs of PhtD. The combination of in vitro growth assays, active zinc uptake, and PhtD expression studies show that the His triad closest to the protein's amino terminus is the most important for zinc acquisition. Intriguingly, in vivo competitive infection studies investigating the amino- and carboxyl-terminal His triad mutants indicate that the motifs have similar importance in colonization. Collectively, our new insights into the contributions of the individual His triad motifs of PhtD, and by extension the other Pht proteins, highlight the crucial role of the first His triad site in zinc acquisition. This study also suggests that the Pht proteins likely play a role beyond zinc acquisition in pneumococcal virulence

    Association between hospital private equity acquisition and outcomes of acute medical conditions among Medicare beneficiaries

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    Importance: As private equity (PE) acquisitions of short-term acute care hospitals (ACHs) continue, their impact on the care of medically vulnerable older adults remains largely unexplored. Objective: To investigate the association between PE acquisition of ACHs and access to care, patient outcomes, and spending among Medicare beneficiaries hospitalized with acute medical conditions. Design, Setting, and Participants: This cross-sectional study used a generalized difference-in-differences approach to compare 21 091 222 patients admitted to PE-acquired vs non-PE-acquired short-term ACHs between January 1, 2001, and December 31, 2018, at least 3 years before to 3 years after PE acquisition. The analysis was conducted between December 28, 2020, and February 1, 2022. Differences were estimated using both facility and hospital service area fixed effects. To assess the robustness of findings, regressions were reestimated after including fixed effects of patient county of origin to account for geographic differences in underlying health risks. Two subset analyses were also conducted: (1) an analysis including only hospitals in hospital referral regions with at least 1 PE acquisition and (2) an analysis stratified by participation in the Hospital Corporation of America 2006 acquisition. The study included Medicare beneficiaries 66 years and older who were hospitalized with 1 of 5 acute medical conditions: acute myocardial infarction (AMI), acute stroke, chronic obstructive pulmonary disease exacerbation, congestive heart failure exacerbation, and pneumonia. Exposures: Acquisition of hospitals by PE firms. Main Outcomes and Measures: Comorbidity burden (measured by Elixhauser comorbidity score), hospital length of stay, in-hospital mortality, 30-day mortality, 30-day readmission, and 30-day episode payments. Results: Among 21 091 222 total Medicare beneficiaries admitted to ACHs between 2001 and 2018, 20 431 486 patients received care at non-PE-acquired hospitals, and 659 736 received care at PE-acquired hospitals. Across all admissions, the mean (SD) age was 79.45 (7.95) years; 11 727 439 patients (55.6%) were male, and 4 550 012 patients (21.6%) had dual insurance; 2 996 560 (14.2%) patients were members of racial or ethnic minority groups, including 2 085 128 [9.9%] Black and 371 648 [1.8%] Hispanic; 18 094 662 patients (85.8%) were White. Overall, 3 083 760 patients (14.6%) were hospitalized with AMI, 2 835 777 (13.4%) with acute stroke, 3 674 477 (17.4%) with chronic obstructive pulmonary disease exacerbation, 5 868 034 (27.8%) with congestive heart failure exacerbation, and 5 629 174 (26.7%) with pneumonia. Comorbidity burden decreased slightly among patients admitted with acute stroke (difference, -0.04 SDs; 95% CI, -0.004 to -0.07 SDs) at acquired hospitals compared with nonacquired hospitals but was unchanged across the other 4 conditions. Among patients with AMI, a greater decrease in in-hospital mortality was observed in PE-acquired hospitals compared with non-PE-acquired hospitals (difference, -1.14 percentage points, 95% CI, -1.86 to -0.42 percentage points). In addition, a greater decrease in 30-day mortality (difference, -1.41 percentage points; 95% CI, -2.26 to -0.56 percentage points) was found at acquired vs nonacquired hospitals. However, 30-day spending and readmission rates remained unchanged across all conditions. The extent and directionality of estimates were preserved across all robustness assessments and subset analyses. Conclusions and Relevance: In this cross-sectional study using a difference-in-differences approach, PE acquisition had no substantial association with the patient-level outcomes examined, although it was associated with a moderate improvement in mortality among Medicare beneficiaries hospitalized with AMI

    Development of a cytology-based multivariate analytical risk index for oral cancer

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    Objectives The diagnosis and management of oral cavity cancers are often complicated by the uncertainty of which patients will undergo malignant transformation, obligating close surveillance over time. However, serial biopsies are undesirable, highly invasive, and subject to inherent issues with poor inter-pathologist agreement and unpredictability as a surrogate for malignant transformation and clinical outcomes. The goal of this study was to develop and evaluate a Multivariate Analytical Risk Index for Oral Cancer (MARIO) with potential to provide non-invasive, sensitive, and quantitative risk assessments for monitoring lesion progression. Materials and methods A series of predictive models were developed and validated using previously recorded single-cell data from oral cytology samples resulting in a “continuous risk score”. Model development consisted of: (1) training base classification models for each diagnostic class pair, (2) pairwise coupling to obtain diagnostic class probabilities, and (3) a weighted aggregation resulting in a continuous MARIO. Results and conclusions Diagnostic accuracy based on optimized cut-points for the test dataset ranged from 76.0% for Benign, to 82.4% for Dysplastic, 89.6% for Malignant, and 97.6% for Normal controls for an overall MARIO accuracy of 72.8%. Furthermore, a strong positive relationship with diagnostic severity was demonstrated (Pearson’s coefficient = 0.805 for test dataset) as well as the ability of the MARIO to respond to subtle changes in cell composition. The development of a continuous MARIO for PMOL is presented, resulting in a sensitive, accurate, and non-invasive method with potential for enabling monitoring disease progression, recurrence, and the need for therapeutic intervention of these lesions

    Comparison of a novel incubator with standard incubator care: A randomised multi-centre, cross-over study

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    Objective: To test the performance, efficacy and usability of the mOm Essential Incubator, a novel, spacesaving infant incubator designed for use in high and low-resource settings. Design and Setting: Prospective, randomised, multi-centre, cross-over design pilot study. Neonatal Units at three UK centres participated. Patients: Stable premature infants of =30 weeks corrected gestational age who required incubator care were eligible to participate. Intervention: Babies were randomised to 24-hour care episodes in either standard or mOm incubators with cross-over after 24 hours. Primary Outcome: Efficacy of temperature maintenance within the normothermic range 36.5°C to 37.5°C. Staff feedback on the usability of the mOm incubator was collected as a secondary outcome. Results: There was no significant difference between the performance of the mOm and standard incubators in maintaining normothermia and no adverse incidents were observed. User feedback was positive, with staff reporting the mOm incubator to be easy to use and quicker to clean between patient uses. Conclusion: For the care of infants =6kg who do not require humidification, the mOm Essential Incubator can be considered as an alternative to standard incubators
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