476 research outputs found

    Lattices of Graphical Gaussian Models with Symmetries

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    In order to make graphical Gaussian models a viable modelling tool when the number of variables outgrows the number of observations, model classes which place equality restrictions on concentrations or partial correlations have previously been introduced in the literature. The models can be represented by vertex and edge coloured graphs. The need for model selection methods makes it imperative to understand the structure of model classes. We identify four model classes that form complete lattices of models with respect to model inclusion, which qualifies them for an Edwards-Havr\'anek model selection procedure. Two classes turn out most suitable for a corresponding model search. We obtain an explicit search algorithm for one of them and provide a model search example for the other.Comment: 29 pages, 18 figures. Restructured Section 5, results unchanged; added references in Section 6; amended example in Section 6.

    The Force of Magnetism: Nursing-Library Collaborations to Support Magnet

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    Background: The ANCC Magnet model is built on 5 Model Components and 14 Forces of Magnetism. The Components and Forces, including Transformational Leadership, Structural Empowerment, Exemplary Professional Practice, New Knowledge, Innovation & Improvement, and Empirical Quality Results (Models), and Professional Development, Quality Improvement, Nurses as Teachers, and Quality of Care (Forces) encourage and recognize professional growth, care improvement, and knowledge dissemination. Familiarity with searching professional literature and information literacy are key skills needed to grow Magnetism. This presentation will describe a collaboration between Magnet leadership and the library to build programs designed to support Magnet values and outcomes. Description: Magnet leadership at a four-time Magnet-designated hospital approached the library with a proposal for an evidence-based program pilot. The librarian’s role in the pilot was co-developing the instructional module introducing EBP, searching the literature and evidence appraisal, and hands-on small group search training with a PhD-prepared nurse. The program was launched in 2015 and post-program analysis showed improved understanding of the EBP process and higher information literacy confidence. Building on the success, the following year the interdisciplinary team consisting of hospital magnet leadership, nursing research leadership, and the librarian added a nursing research program. The ongoing educational programs were named best practice by ANCC Magnet appraisers and the program projects were cited in the Magnet documentation. Following appraiser evaluation, to address the need to disseminate knowledge externally, this year the hospital is launching a program helping nurses publish. Conclusion: The program started as an instructional venture introducing the concepts of evidence-based practice and nursing research to hospital staff nurses. Since its inception, 6 projects have led to practice change, 3 have been presented at conferences, one is being written up for publication. Some projects evolved from evidence-based to research questions and from smaller to larger studies in different hospital settings. Many original program participants have continued with the program or have developed independent research studies. The success of this collaborative program lies not only in renewed Magnet designation, but also by nurse engagement in practice change and nursing research.https://digitalcommons.psjhealth.org/other_pubs/1061/thumbnail.jp

    Effective Communication and Teamwork Improve Patient Safety

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    Work environment influences the effectiveness of care for patients in any healthcare setting. It is even more important in settings such as the neonatal ICU (NICU) where this project took place. When the environment is not healthy, communication may suffer and result in poor patient outcomes and, family, patient, and staff dissatisfaction. The purpose of this quality improvement project was to understand how the implementation of the TeamSTEPPS program, for nurses in the NICU, could impact the safety culture as measured by the AACN Healthy Work Environment (HWE) tool. Lewin\u27s professional practice change theory and the AHRQ change model were used to guide the project. The previously validated HWE survey, made up of 6 standards including communication, and leadership was provided to 71 NICU nurses with only 41 completing the baseline survey and 4 weeks later, 31 completing the post intervention survey after the TeamSTEPPS training. An independent t test was used to examine baseline and post TeamSTEPPS intervention HWE results against the HWE benchmark. Results indicated that post intervention scores met the benchmark although scores did not meet the benchmark prior to the intervention. Data were also analyzed with a paired t test to determine the significance of the improvement in the pre to post intervention results. Three of the 6 HWE standards, skilled communication (p = .004), adequate staffing (p = .002), and authentic leadership (p \u3c .001) reached significant levels post TeamSTEPPS training compared to the pre TeamSTEPPS scores. Through the use of TeamSTEPPS training communication improved and the potential for improvement in patient safety promotes positive social change

    Pyrrolidinium chloride

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    The title compound, C4H10N+·Cl−, was obtained as a decomposition product from 2,6-bis­(pyrrolidin­yl)pyridine. The anion lies on the same cristallographic mirror plane as the N atom of the cation, the complete cation being generated by mirror symmetry. The anions and cations are connected by N+—H⋯Cl− hydrogen bonds into chains along [100]. The pyrrolidinium cation is puckered in an envelope conformation E N1

    The acute phase reaction and its prognostic impact in patients with head and neck squamous cell carcinoma: Single biomarkers including c-reactive protein versus biomarker profiles

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    C-reactive protein (CRP) has a prognostic impact in head and neck squamous cell carcinoma (HNSCC). However, the acute phase reaction involves many other proteins depending on its inducing events, including various cytokines that can function as reaction inducers. In the present study, we compared the pretreatment acute phase cytokine profile for 144 patients with potentially curative HNSCC. We investigated the systemic levels of interleukin (IL)6 family mediators (glycoprotein (gp130), IL6 receptor (R)α, IL6, IL27, IL31, oncostatin M (OSM), ciliary neurotrophic factor (CNTF)), IL1 subfamily members (IL1R antagonist (A), IL33Rα), and tumor necrosis factor (TNF)α. Patient subsets identified from this 10-mediator profile did not differ with regard to disease stage, human papilloma virus (HPV) status, CRP levels, or death cause. Increased CRP, IL6, and IL1RA levels were independent markers for HNSCC-related death in the whole patient population. Furthermore, gp130, IL6Rα, and IL31 were suggested to predict prognosis among tumor HPV-negative patients. Only IL6 predicted survival in HPV-positive patients. Finally, we did a clustering analysis of HPV-negative patients based on six acute phase mediators that showed significant or borderline association with prognosis in Kaplan–Meier analyses; three subsets could then be identified, and they differed in survival (p < 0.001). To conclude, (i) HPV-negative and HPV-positive HNSCC patients show similar variations of their systemic acute phase profiles; (ii) the prognostic impact of single mediators differs between these two patient subsets; and (iii) for HPV-negative patients, acute phase profiling identifies three patient subsets that differ significantly in survival.publishedVersio

    Serum levels of the IL-6 family of cytokines predict prognosis in renal cell carcinoma (RCC)

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    Purpose An improved understanding of RCC immunology should shed further light on RCC tumor biology. Our objective was to study to what extent serum levels of the IL-6 family of cytokines at diagnosis were relevant to survival. Methods A total of 118 consecutively patients with RCC, in which the tumor was surgically removed at Haukeland University Hospital during the period from 2007 to 2010, were included. The patients were followed-up for 10 years. The morning before surgery blood was sampled and serum frozen, with levels of IL-6, IL-27, IL-31, OSM, CNTF, IL-6Rα and gp130 determined. Results Among patients with the highest quartile of IL-6 (> 8 pg/ml) (n = 29), six of nine who had metastasis at diagnosis had such high IL-6 values. Among presumed radically treated patients, a high IL-6 and IL-27 strongly predicted recurrence. In particular, the predictions among patients with large (diameter > 7 cm) tumors were excellent regarding both IL-6 and IL-27 values. High gp130 serum levels predicted an overall survival (OS) among RCC patients with large tumors. Patients with a high IL-6 exhibited a strong expression of IL-6 in endothelial- and vascular smooth muscle cells. Moreover, the level of intra-tumoral CD3-positive cells predicted survival. Conclusions IL-6 and IL-27 seem to play a role in RCC biology. IL-6 enables the pinpointing of metastatic condition at diagnosis, as well as together with IL-27, the predicting of survival and recurrence. Endothelial cells and vascular smooth muscle cells are both suggested as important sources of IL-6.publishedVersio

    Hookworm Infection and Environmental Factors in Mbeya Region, Tanzania: A Cross-sectional, Population-based study.

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    Hookworm disease is one of the most common infections and cause of a high disease burden in the tropics and subtropics. Remotely sensed ecological data and model-based geostatistics have been used recently to identify areas in need for hookworm control. Cross-sectional interview data and stool samples from 6,375 participants from nine different sites in Mbeya region, south-western Tanzania, were collected as part of a cohort study. Hookworm infection was assessed by microscopy of duplicate Kato-Katz thick smears from one stool sample from each participant. A geographic information system was used to obtain remotely sensed environmental data such as land surface temperature (LST), vegetation cover, rainfall, and elevation, and combine them with hookworm infection data and with socio-demographic and behavioral data. Uni- and multivariable logistic regression was performed on sites separately and on the pooled dataset. Univariable analyses yielded significant associations for all ecological variables. Five ecological variables stayed significant in the final multivariable model: population density (odds ratio (OR) = 0.68; 95% confidence interval (CI) = 0.63-0.73), mean annual vegetation density (OR = 0.11; 95% CI = 0.06-0.18), mean annual LST during the day (OR = 0.81; 95% CI = 0.75-0.88), mean annual LST during the night (OR = 1.54; 95% CI = 1.44-1.64), and latrine coverage in household surroundings (OR = 1.02; 95% CI = 1.01-1.04). Interaction terms revealed substantial differences in associations of hookworm infection with population density, mean annual enhanced vegetation index, and latrine coverage between the two sites with the highest prevalence of infection. This study supports previous findings that remotely sensed data such as vegetation indices, LST, and elevation are strongly associated with hookworm prevalence. However, the results indicate that the influence of environmental conditions can differ substantially within a relatively small geographic area. The use of large-scale associations as a predictive tool on smaller scales is therefore problematic and should be handled with care

    Reconsidering precolumbian human colonization in the Galápagos Islands, Republic of Ecuador

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    Fifty years ago, Heyerdahl and Skjølsvold (1956, 1990) collected material from five archaeological sites in the Galápagos Islands. They retained earthenwares of possible precolumbian origin and discarded ceramic, metal, and glass artifacts postdating the arrival of the Spanish in A.D. 1535. Consequently, they argued that each site was formed as the results of a series of discard events from unrelated short-term occupations extending from the precolumbian to the historical era, and that the earthenwares represented occasional visits by fishermen from precolumbian Peru and Ecuador. In 2005, we re-excavated the sites and collected all the excavated materials. Our results show that each class of material, irrespective of age or origin, was distributed spatially and stratigraphically in the same pattern, contradicting the former assumption of multiple, unrelated occupations. We reject the palimpsest model in favor of the null hypothesis of single-phase site occupation. Analysis of putatively precolumbian pottery using optically-stimulated luminescence dating indicates that it is mostly of historical age. Radiocarbon dating confirms that the archaeological sites are younger than the sixteenth century. Research on sedimentary cores shows probable anthropogenic impacts as restricted to the last 500 years. We conclude that there was no human occupation in the Galápagos Islands until the historical era

    Ambient Particulate Matter Air Pollution and Venous Thromboembolism in the Women’s Health Initiative Hormone Therapy Trials

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    BackgroundThe putative effects of postmenopausal hormone therapy on the association between particulate matter (PM) air pollution and venous thromboembolism (VTE) have not been assessed in a randomized trial of hormone therapy, despite its widespread use among postmenopausal women.ObjectiveIn this study, we examined whether hormone therapy modifies the association of PM with VTE risk.MethodsPostmenopausal women 50–79 years of age (n = 26,450) who did not have a history of VTE and who were not taking anticoagulants were enrolled in the Women’s Health Initiative Hormone Therapy trials at 40 geographically diverse U.S. clinical centers. The women were randomized to treatment with estrogen versus placebo (E trial) or to estrogen plus progestin versus placebo (E + P trial). We used age-stratified Cox proportional hazard models to examine the association between time to incident, centrally adjudicated VTE, and daily mean PM concentrations spatially interpolated at geocoded addresses of the participants and averaged over 1, 7, 30, and 365 days.ResultsDuring the follow-up period (mean, 7.7 years), 508 participants (2.0%) had VTEs at a rate of 2.6 events per 1,000 person-years. Unadjusted and covariate-adjusted VTE risk was not associated with concentrations of PM 0.05) regardless of PM averaging period, either before or after combining data from both trials [e.g., combined trial-adjusted hazard ratios (95% confidence intervals) per 10 μg/m3 increase in annual mean PM2.5 and PM10, were 0.93 (0.54–1.60) and 1.05 (0.72–1.53), respectively]. Findings were insensitive to alternative exposure metrics, outcome definitions, time scales, analytic methods, and censoring dates.ConclusionsIn contrast to prior research, our findings provide little evidence of an association between short-term or long-term PM exposure and VTE, or clinically important modification by randomized exposure to exogenous estrogens among postmenopausal women
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