Racial differences in heart failure with preserved ejection fraction in the ambulatory heart failure population

Racial differences in heart failure with preserved ejection fraction (HFpEF) have rarely been studied in an ambulatory, financially "equal access" cohort, although the majority of such patients are treated as outpatients. ^ Retrospective data was collected from 2,526 patients (2,240 Whites, 286 African American) with HFpEF treated at 153 VA clinics, as part of the VA External Peer Review Program (EPRP) between October 2000 and September 2002. Kaplan Meier curves (stratified by race) were created for time to first heart failure (HF) hospitalization, all cause hospitalization and death and Cox proportional multivariate regression models were constructed to evaluate the effect of race on these outcomes. ^ African American patients were younger (67.7 ± 11.3 vs. 71.2 ± 9.8 years; p < 0.001), had lower prevalence of atrial fibrillation (24.5 % vs. 37%; p <0.001), chronic obstructive pulmonary disease (23.4 % vs. 36.9%, p <0.001), but had higher blood pressure (systolic blood pressure > 120 mm Hg 77.6% vs. 67.8%; p < 0.01), glomerular filtration rate (67.9 ± 31.0 vs. 61.6 ± 22.6 mL/min/1.73 m2; p < 0.001), anemia (56.6% vs. 41.7%; p <0.001) as compared to whites. African Americans were found to have higher risk adjusted rate of HF hospitalization (HR 1.52, 95% CI 1.1 - 2.11; p = 0.01), with no difference in risk-adjusted all cause hospitalization (p = 0.80) and death (p= 0.21). ^ In a financially "equal access" setting of the VA, among ambulatory patients with HFpEF, African Americans have similar rates of mortality and all cause hospitalization but have an increased risk of HF hospitalizations compared to whites.^

Ascertainment, meta-analysis and reporting of adverse reactions in clinical trials of antibiotics

The ascertainment and analysis of adverse reactions to investigational agents presents a significant challenge because of the infrequency of these events, their subjective nature and the low priority of safety evaluations in many clinical trials. A one year review of antibiotic trials published in medical journals demonstrates the lack of standards in identifying and reporting these potentially fatal conditions. This review also illustrates the low probability of observing and detecting rare events in typical clinical trials which include fewer than 300 subjects. Uniform standards for ascertainment and reporting are suggested which include operational definitions of study subjects. Meta-analysis of selected antibiotic trials using multivariate regression analysis indicates that meaningful conclusions may be drawn from data from multiple studies which are pooled in a scientifically rigorous manner. ^

A QUANTITATIVE INVESTIGATION OF SOURCE AND ELEMENTAL COMPOSITION OF INDOOR AND OUTDOOR FINE PARTICULATE AIR POLLUTION IN HOUSTON (TEXAS)

An investigation was undertaken to determine the chemical characterization of inhalable particulate matter in the Houston area, with special emphasis on source identification and apportionment of outdoor and indoor atmospheric aerosols using multivariate statistical analyses.^ Fine (<2.5 (mu)m) particle aerosol samples were collected by means of dichotomous samplers at two fixed site (Clear Lake and Sunnyside) ambient monitoring stations and one mobile monitoring van in the Houston area during June-October 1981 as part of the Houston Asthma Study. The mobile van allowed particulate sampling to take place both inside and outside of twelve homes.^ The samples collected for 12-h sampling on a 7 AM-7 PM and 7 PM-7 AM (CDT) schedule were analyzed for mass, trace elements, and two anions. Mass was determined gravimetrically. An energy-dispersive X-ray fluorescence (XRF) spectrometer was used for determination of elemental composition. Ion chromatography (IC) was used to determine sulfate and nitrate.^ Average chemical compositions of fine aerosol at each site were presented. Sulfate was found to be the largest single component in the fine fraction mass, comprising approximately 30% of the fine mass outdoors and 12% indoors, respectively.^ Principal components analysis (PCA) was applied to identify sources of aerosols and to assess the role of meteorological factors on the variation in particulate samples. The results suggested that meteorological parameters were not associated with sources of aerosol samples collected at these Houston sites.^ Source factor contributions to fine mass were calculated using a combination of PCA and stepwise multivariate regression analysis. It was found that much of the total fine mass was apparently contributed by sulfate-related aerosols. The average contributions to the fine mass coming from the sulfate-related aerosols were 56% of the Houston outdoor ambient fine particulate matter and 26% of the indoor fine particulate matter.^ Characterization of indoor aerosol in residential environments was compared with the results for outdoor aerosols. It was suggested that much of the indoor aerosol may be due to outdoor sources, but there may be important contributions from common indoor sources in the home environment such as smoking and gas cooking. ^

SEVERE HEAD TRAUMA, EMERGENCY TRANSPORT, AND PATIENT OUTCOME

Trauma and severe head injuries are important issues because they are prevalent, because they occur predominantly in the young, and because variations in clinical management may matter. Trauma is the leading cause of death for those under age 40. The focus of this head injury study is to determine if variations in time from the scene of accident to a trauma center hospital makes a difference in patient outcomes.^ A trauma registry is maintained in the Houston-Galveston area and includes all patients admitted to any one of three trauma center hospitals with mild or severe head injuries. A study cohort, derived from the Registry, includes 254 severe head injury cases, for 1980, with a Glasgow Coma Score of 8 or less.^ Multiple influences relate to patient outcomes from severe head injury. Two primary variables and four confounding variables are identified, including time to emergency room, time to intubation, patient age, severity of injury, type of injury and mode of transport to the emergency room. Regression analysis, analysis of variance, and chi-square analysis were the principal statistical methods utilized.^ Analysis indicates that within an urban setting, with a four-hour time span, variations in time to emergency room do not provide any strong influence or predictive value to patient outcome. However, data are suggestive that at longer time periods there is a negative influence on outcomes. Age is influential only when the older group (55-64) is included. Mode of transport (helicopter or ambulance) did not indicate any significant difference in outcome.^ In a multivariate regression model, outcomes are influenced primarily by severity of injury and age which explain 36% (R('2)) of variance. Inclusion of time to emergency room, time to intubation, transport mode and type injury add only 4% (R('2)) additional contribution to explaining variation in patient outcome.^ The research concludes that since the group most at risk to head trauma is the young adult male involved in automobile/motorcycle accidents, more may be gained by modifying driving habits and other preventive measures. Continuous clinical and evaluative research are required to provide updated clinical wisdom in patient management and trauma treatment protocols. A National Institute of Trauma may be required to develop a national public policy and evaluate the many medical, behavioral and social changes required to cope with the country's number 3 killer and the primary killer of young adults.^

Mapping decadal land cover changes in the woodlands of north eastern Namibia using the Landsat satellite archive (1975-2014)

Woodland savannahs provide essential ecosystem functions and services to communities. On the African continent, they are widely utilized and converted to intensive land uses. This study investigates the land cover changes of 108,038 km**2 in NE Namibia using multi-temporal, multi-sensor Landsat imagery, at decadal intervals from 1975 to 2014, with a post-classification change detection method and supervised Regression Tree classifiers. We discuss likely impacts of land tenure and reforms over the past four decades on changes in land use and land cover. These changes included losses, gains and exchanges between predominant land cover classes. Exchanges comprised logical conversions between woodland and agricultural classes, implying woodland clearing for arable farming, cropland abandonment and vegetation succession. The most dominant change was a reduction in the area of the woodland class due to the expansion of the agricultural class, specifically, small-scale cereal and pastoral production. Woodland area decreased from 90% of the study area in 1975 to 83% in 2014, while cleared land increased from 9% to 14%. We found that the main land cover changes are conversion from woodland to agricultural and urban land uses, driven by urban expansion and woodland clearing for subsistence-based agriculture and pastoralism.

Literature review of elasmobranch bycatch and retention rate

To address growing concern over the effects of fisheries non-target catch on elasmobranchs worldwide, the accurate reporting of elasmobranch catch is essential. This requires data on a combination of measures, including reported landings, retained and discarded non-target catch, and post-discard survival. Identification of the factors influencing discard vs. retention is needed to improve catch estimates and to determine wasteful fishing practices. To do this we compared retention rates of elasmobranch non-target catch in a broad subset of fisheries throughout the world by taxon, fishing country, and gear. A regression tree and random forest analysis indicated that taxon was the most important determinant of retention in this dataset, but all three factors together explained 59% of the variance. Estimates of total elasmobranch removals were calculated by dividing the FAO global elasmobranch landings by average retention rates and suggest that total elasmobranch removals may exceed FAO reported landings by as much as 400%. This analysis is the first effort to directly characterize global drivers of discards for elasmobranch non-target catch. Our results highlight the importance of accurate quantification of retention and discard rates to improve assessments of the potential impacts of fisheries on these species.

Model parameter

Interannual environmental variability in Peru is dominated by the El Niño Southern Oscillation (ENSO). The most dramatic changes are associated with the warm El Niño (EN) phase (opposite the cold La Niña phase), which disrupts the normal coastal upwelling and affects the dynamics of many coastal marine and terrestrial resources. This study presents a trophic model for Sechura Bay, located at the northern extension of the Peruvian upwelling system, where ENSO-induced environmental variability is most extreme. Using an initial steady-state model for the year 1996, we explore the dynamics of the ecosystem through the year 2003 (including the strong EN of 1997/98 and the weaker EN of 2002/03). Based on support from literature, we force biomass of several non-trophically-mediated 'drivers' (e.g. Scallops, Benthic detritivores, Octopus, and Littoral fish) to observe whether the fit between historical and simulated changes (by the trophic model) is improved. The results indicate that the Sechura Bay Ecosystem is a relatively inefficient system from a community energetics point of view, likely due to the periodic perturbations of ENSO. A combination of high system productivity and low trophic level target species of invertebrates (i.e. scallops) and fish (i.e. anchoveta) results in high catches and an efficient fishery. The importance of environmental drivers is suggested, given the relatively small improvements in the fit of the simulation with the addition of trophic drivers on remaining functional groups' dynamics. An additional multivariate regression model is presented for the scallop Argopecten purpuratus, which demonstrates a significant correlation between both spawning stock size and riverine discharge-mediated mortality on catch levels. These results are discussed in the context of the appropriateness of trophodynamic modeling in relatively open systems, and how management strategies may be focused given the highly environmentally influenced marine resources of the region.

Geospatial analysis of groundwater depth for manual well drilling suitability in the Zinder Region, Niger

Manual and low-tech well drilling techniques have potential to assist in reaching the United Nations' millennium development goal for water in sub-Saharan Africa. This study used publicly available geospatial data in a regression tree analysis to predict groundwater depth in the Zinder region of Niger to identify suitable areas for manual well drilling. Regression trees were developed and tested on a database for 3681 wells in the Zinder region. A tree with 17 terminal leaves provided a range of ground water depth estimates that were appropriate for manual drilling, though much of the tree's complexity was associated with depths that were beyond manual methods. A natural log transformation of groundwater depth was tested to see if rescaling dataset variance would result in finer distinctions for regions of shallow groundwater. The RMSE for a log-transformed tree with only 10 terminal leaves was almost half that of the untransformed 17 leaf tree for groundwater depths less than 10 m. This analysis indicated important groundwater relationships for commonly available maps of geology, soils, elevation, and enhanced vegetation index from the MODIS satellite imaging system.

Variation of PM2.5 concentrations in relation to street washing activities

Several studies conducted in urban areas have pointed out that road dust resuspension contributes significantly to PM concentration levels. Street washing is one of the methods proposed to reduce resuspended road dust contributions to ambient PM concentrations. As resuspended particles are mainly found in the coarse mode, published studies investigating the effects of street washing have focused on PM10 size fraction. As the PM2.5 mass fraction of particles originating from mechanical abrasion processes may still be significant we conducted a study in order to evaluate the effects of street washing on the mitigation of resuspension of fine particles. The PM2.5 mass concentration data were examined and integrated with the occurrence of street washing activities. In addition, the effect of the meteorological variability, traffic flow and street washing activities, on ambient PM2.5 levels was valuated by means of a multivariate regression model. The results revealed that traffic low is the most important factor that controls PM2.5 hourly concentrations while street washing activities did not influence fine particle mass levels.

Transferência transplacentária de anticorpos em gestações gemelares

Há poucos dados na literatura sobre o transporte transplacentário de imunoglobulinas em gestações múltiplas. O objetivo deste estudo foi observar fatores que influenciam a concentração de imunoglobulina G (IgG) no cordão umbilical dos neonatos e a transferência transplacentária de IgG total e de IgG contra o Streptococcus grupo B (EGB), e lipopolissacarídeos (LPS) de Klebsiella spp. e Pseudomonas spp.. Métodos: estudo prospectivo realizado no Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo no período de 2012 a 2013. Foram coletadas amostras de sangue materno e de cordão umbilical no momento do parto. Os critérios de inclusão foram gestações gemelares com ausência de sinais de infecção por HIV, citomegalovírus, Hepatites B e C, toxoplasmose e rubéola e ausência de doenças autoimunes, malformação fetal e síndromes genéticas. A análise multivariada foi realizada para avaliar a associação entre os níveis de IgG em cordão umbilical e as taxas de transferência de anticorpos com a concentração materna de IgG, a corionicidade da gestação, a presença de insuficiência placentária, a restrição de crescimento intrauterino, a idade gestacional de nascimento, o peso de nascimento, o tabagismo, a doença materna e a via de parto. Resultados: a concentração de IgG total em cordão umbilical apresentou correlação positiva com os níveis maternos séricos de IgG total e a idade gestacional do parto. Os níveis de IgG total em cordão umbilical foram significativamente menores em gestações monocoriônicas quando comparadas às dicoriônicas. A taxa de transferência de IgG total apresentou correlação positiva com a idade gestacional do parto, mas negativa com as concentrações maternas de IgG total. As concentrações de IgG contra EGB e LPS de Klebsiella spp. e Pseudomonas spp. apresentaram associação com os níveis maternos de IgG específicos contra esses antígenos e com o diabetes. Os níveis de IgG contra LPS de Klebsiella spp. também foram associados com o peso de nascimento e com hipertensão materna. As taxas de transferência de IgG contra EGB e LPS de Pseudomonas spp. apresentaram correlação com os níveis maternos de IgG específicos contra os antígenos referidos. A taxa de transferência de IgG contra EGB também esteve associada com a idade gestacional do parto, enquanto a taxa de transferência de IgG contra LPS de Pseudomonas spp. apresentou correlação com diabetes. Não houve correlação entre a taxa de transferência de IgG contra a LPS de Klebsiella spp. com nenhum fator analisado. Conclusão: em gestações gemelares, a concentração total de IgG em cordão umbilical foi influenciada pela concentração materna de IgG total, pela idade gestacional do parto e pela corionicidade placentária. As concentrações de IgG total foram significativamente menores em gestações monocoriônicas que em dicoriônicas. As concentrações séricas de IgG contra EGB e LPS de Klebsiella spp. e Pseudomonas spp. em cordão umbilical apresentaram associação com os níveis maternos de IgG específicos contra esses antígenos e com a presença de diabetes. Todos os outros parâmetros estudados apresentaram diferentes associações com as concentrações de IgG e com as taxas de transferências de IgG específicas contra cada antígeno investigado

Atividade nervosa simpática em pacientes com síndromes isquêmicas miocárdicas instáveis: estudo comparativo com marcadores inflamatórios

INTRODUÇÃO: Em pacientes com síndromes isquêmicas miocárdicas instáveis (SIMI), tanto a hiperatividade simpática quanto a resposta inflamatória exacerbada se associam a pior prognóstico. No entanto, ainda é desconhecido se existe alguma correlação entre esses dois marcadores de evolução desfavorável. OBJETIVOS: Correlacionar a atividade nervosa simpática muscular com marcadores inflamatórios nas fases precoce e tardia de pacientes portadores de SIMI. MÉTODOS: Pacientes hospitalizados com diagnóstico de SIMI e evolução favorável foram incluídos de forma prospectiva desde que apresentassem idade entre 18 e 65 anos e aterosclerose coronária comprovada por cinecoronariografia. Logo após a inclusão no estudo foram coletadas informações basais, e no quarto dia (± 1 dia) de internação os pacientes foram submetidos à avaliação da ANSM e coleta concomitante de amostra sanguínea para dosagem de proteína CReativa ultrassensível (PCR-us), interleucina-6 (IL6), e fosfolipase A2 associada à lipoproteína (Lp-PLA2). ANSM foi obtida pela técnica de microneurografia do nervo fibular. As medidas e respectivas análises de correlação foram repetidas em 1, 3 e 6 meses após a hospitalização. Correlações entre ANSM e marcadores inflamatórios foram analisadas por meio do teste de Pearson (variáveis de distribuição não-paramétrica foram transformadas logaritmicamente). Modelos de regressão linear múltipla foram criados para avaliar os efeitos independentes. RESULTADOS: Foram estudados 34 pacientes com idade média de 51,7±7,0 anos, sendo 79,4% do sexo masculino. A prevalência de hipertensão arterial foi de 64,7%, diabetes mellitus 8,8%, e doença arterial coronária prévia de 20,6%. A apresentação foi IAM com supradesnível de ST em 18 pacientes (52,9%), IAM sem supra de ST em 14 (41,2%) e angina instável em 02 pacientes (5,9%). Tanto ANSM quanto biomarcadores inflamatórios estavam elevados durante a fase aguda das SIMI e diminuíram ao longo do tempo. Na fase hospitalar, a mediana da PCR-us foi 17,75 (8,57; 40,15) mg/L, e IL-6 6,65 (4,45; 8,20) pg/ml, a Lp- PLA2 média foi 185,8 ± 52,2 nmol/min/ml, e ANSM média 64,2 ± 19,3 impulsos/100bpm. Após 6 meses, houve diminuição significativa de todas essas variáveis quando comparadas com a fase hospitalar. Entretanto, não houve correlação significativa entre a atividade simpática e qualquer dos marcadores inflamatórios analisados, em nenhuma das fases analisadas (p > 0,05), Por outro lado, ANSM se correlacionou independentemente com níveis de CKMB na fase aguda (p=0,027), e com fração de ejeção do VE na fase crônica (p=0,026). CONCLUSÃO: Apesar do aumento inicial dos níveis de marcadores inflamatórios e da atividade simpática em pacientes com SIMI, não houve correlação significativa entre esses parâmetros em nenhuma das fases analisadas, sugerindo que as alterações dessas variáveis estariam relacionadas a diferentes vias fisiopatológicas

Explaining Euroskepticism as a function of regional representation. ACES Working Papers No. 3, August 2008

Recent scholarship has suggested that nation-states will gradually fade away in favor of regions and super-regions as the main actors within a European Union characterized by strong regional identities. At the same time, recent developments have shown that citizen support for European integration is essential for any future development of the Union. The puzzle inspiring this paper is the finding that the greatest support for the EU increasingly stems from minority nationalist regions seeking to bypass their central states to achieve their policy goals at the EU level. This paper empirically tests this suggestion, while shedding light on the relationship between the quality of representation of regional interests at the EU level and positive citizen attitudes towards the EU. In particular, it finds two explanations for cross-regional variation in the relationship between Euroskepticism and representation: (1) a cultural explanation, embodied by a difference in the nature and quality of representation between regions that are linguistically distinctive and regions that are not; and (2) an institutional explanation, embodied by a difference in the nature and quality of representation between regions from federal and non-federal member states. The paper uses an eclectic methodological approach, first utilizing multivariate regression analysis, estimating logistic and ordinal logit models that help explain variation in Euroskepticism at the regional level. The results are then complemented by the findings of in-depth elite interviews of regional representatives - more specifically the directors of a selection of the many regional information offices present in Brussels. This paper takes the study of Euroskepticism to a new level, as most previous scholarly work has focused on explanations at the individual or at the member state level. At the same time it strengthens the notion of a growing importance of a "Europe of the regions."

Macular atrophy in patients with long-term anti-VEGF treatment for neovascular age-related macular degeneration.

PURPOSE To identify the prevalence and progression of macular atrophy (MA) in neovascular age-related macular degeneration (AMD) patients under long-term anti-vascular endothelial growth factor (VEGF) therapy and to determine risk factors. METHOD This retrospective study included patients with neovascular AMD and ≥30 anti-VEGF injections. Macular atrophy (MA) was measured using near infrared and spectral-domain optical coherence tomography (SD-OCT). Yearly growth rate was estimated using square-root transformation to adjust for baseline area and allow for linearization of growth rate. Multiple regression with Akaike information criterion (AIC) as model selection criterion was used to estimate the influence of various parameters on MA area. RESULTS Forty-nine eyes (47 patients, mean age 77 ± 14) were included with a mean of 48 ± 13 intravitreal anti-VEGF injections (ranibizumab:37 ± 11, aflibercept:11 ± 6, mean number of injections/year 8 ± 2.1) over a mean treatment period of 6.2 ± 1.3 years (range 4-8.5). Mean best-corrected visual acuity improved from 57 ± 17 letters at baseline (= treatment start) to 60 ± 16 letters at last follow-up. The MA prevalence within and outside the choroidal neovascularization (CNV) border at initial measurement was 45% and increased to 74%. Mean MA area increased from 1.8 ± 2.7 mm(2) within and 0.5 ± 0.98 mm(2) outside the CNV boundary to 2.7 ± 3.4 mm(2) and 1.7 ± 1.8 mm(2) , respectively. Multivariate regression determined posterior vitreous detachment (PVD) and presence/development of intraretinal cysts (IRCs) as significant factors for total MA size (R(2) = 0.16, p = 0.02). Macular atrophy (MA) area outside the CNV border was best explained by the presence of reticular pseudodrusen (RPD) and IRC (R(2) = 0.24, p = 0.02). CONCLUSION A majority of patients show MA after long-term anti-VEGF treatment. Reticular pseudodrusen (RPD), IRC and PVD but not number of injections or treatment duration seem to be associated with the MA size.

Constructing and evaluating alternative prediction models for identifying clinically relevant cases in an STD clinic

Thesis (Master's)--University of Washington, 2016-06

Is There a Role for Narrative Attributes in Scientific Literature?

Thesis (Master's)--University of Washington, 2016-06