308 research outputs found

    Employing Spatial Metrics in Urban Land-Use / Land-Cover Mapping: Comparing the Getis and Geary Indices

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    We examine the potential of supplementing per-pixel classifiers with the Getis index (Gi) in comparison to the Geary’s C on a subset of Ikonos imagery for urban land-use and land-cover classification. The test is pertinent considering that the Gi is generally considered more capable of identifying clusters of points with similar attributes. We quantify the impact of varying distance thresholds on the classification product and demonstrate how well the Gi identified cold and hot spots in comparison to Geary’s C. The exercise also provides a rule of thumb for effectively measuring spatial association in connection to adjacency. We are able to support existing literature that measuring local variability improves classification over spectral information alone. The results, however, neither confirm nor deny the challenge on whether measuring cold and hot spots rather than just spatial association improves classification accuracy

    Brachybacterium nesterenkovii isolated from a human blood culture-a first report

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    Brachybacterium is a genus of Gram-positive bacteria that rarely causes infections in humans. Here we report the case of an 8-month-old infant who presented with an acute febrile illness. During the diagnostic process, a blood culture was positive with Gram-positive cocci that were identified as Brachybacterium nesterenkovii by MALDI-TOF. As a result of the unclear clinical significance of this isolate and the continuous febrile state, a second blood culture was taken and returned B. nesterenkovii once more. To our knowledge this is the first time that B. nesterenkovii has been isolated from human blood cultures during the course of a systemic infection

    Cluster-Randomized Trial of a Behavioral Intervention to Incorporate a Treat-to-Target Approach to Care of US Patients With Rheumatoid Arthritis

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    OBJECTIVE: To assess the feasibility and efficacy of implementing a treat-to-target approach versus usual care in a US-based cohort of rheumatoid arthritis patients. METHODS: In this behavioral intervention trial, rheumatology practices were cluster-randomized to provide treat-to-target care or usual care. Eligible patients with moderate/high disease activity (Clinical Disease Activity Index [CDAI] score \u3e 10) were followed for 12 months. Both treat-to-target and usual care patients were seen every 3 months. Treat-to-target providers were to have monthly visits with treatment acceleration at a minimum of every 3 months in patients with CDAI score \u3e 10; additional visits and treatment acceleration were at the discretion of usual care providers and patients. Coprimary end points were feasibility, assessed by rate of treatment acceleration conditional on CDAI score \u3e 10, and achievement of low disease activity (LDA; CDAI score \u3c /=10) by an intent-to-treat analysis. RESULTS: A total of 14 practice sites per study arm were included (246 patients receiving treat-to-target and 286 receiving usual care). The groups had similar baseline demographic and clinical characteristics. Rates of treatment acceleration (treat-to-target 47% versus usual care 50%; odds ratio [OR] 0.92 [95% confidence interval (95% CI) 0.64, 1.34]) and achievement of LDA (treat-to-target 57% versus usual care 55%; OR 1.05 [95% CI 0.60, 1.84]) were similar between groups. Treat-to-target providers reported patient reluctance and medication lag time as common barriers to treatment acceleration. CONCLUSION: This study is the first to examine the feasibility and efficacy of a treat-to-target approach in typical US rheumatology practice. Treat-to-target care was not associated with increased likelihood of treatment acceleration or achievement of LDA, and barriers to treatment acceleration were identified

    A Conserved Multi-Gene Family Induces Cross-Reactive Antibodies Effective in Defense against Plasmodium falciparum

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    BACKGROUND: Two related merozoite surface proteins, MSP3 and MSP6, have previously been identified as targets of antibody-dependent cellular inhibition (ADCI), a protective mechanism against Plasmodium falciparum malaria. Both MSP3 and MSP6 share a common characteristic small N-terminal signature amino-acid stretch (NLRNA/G), a feature similar to MSP3-like orthologs identified in other human and primate malaria parasites. METHODS/RESULTS: This signature amino-acid sequence led to the identification of eight ORFs contiguously located on P. falciparum chromosome 10. Our subsequent investigations on their expression, localization, sequence conservation, epitope sharing, immunogenicity and the functional role of antibodies in defense are reported here. Six members of P. falciparum MSP3-multigene family share similar sequence organization within their C-terminal regions, are simultaneously expressed as merozoite surface proteins and are highly conserved among parasite isolates. Each of these proteins is a target of naturally occurring antibodies effective at parasite killing in ADCI assays. Moreover, both naturally occurring antibodies and those generated by immunization display cross-reactivity with other members of the family and exhibit varied binding avidities. CONCLUSIONS/SIGNIFICANCE: The unusual characteristics of the MSP3 multi-gene family lead us to hypothesize that the simultaneous expression of targets eliciting cross-reactive antibody responses capable of controlling parasite densities could represent an immune process selected through evolution to maintain homeostasis between P. falciparum and human hosts; a process that allows the continuous transmission of the parasite without killing the host. Our observations also have practical consequences for vaccine development by suggesting MSP3 vaccine efficacy might be improved when combined with the various C-terminus regions of the MSP3 family members to generate a wider range of antibodies acting and to increase vaccine immunogenicity in varied human genetic backgrounds

    An experimental investigation into the dimensional error of powder-binder three-dimensional printing

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    This paper is an experimental investigation into the dimensional error of the rapid prototyping additive process of powder-binder three-dimensional printing. Ten replicates of a purpose-designed part were produced using a three-dimensional printer, and measurements of the internal and external features of all surfaces were made using a general purpose coordinate measuring machine. The results reveal that the bases of all replicates (nominally flat) have a concave curvature, producing a flatness error of the primary datum. This is in contrast to findings regarding other three-dimensional printing processes, widely reported in the literature, where a convex curvature was observed. All external surfaces investigated in this study showed positive deviation from nominal values, especially in the z-axis. The z-axis error consisted of a consistent positive cumulative error and a different constant error in different replicates. By compensating for datum surface error, the average total height error of the test parts can be reduced by 25.52 %. All the dimensional errors are hypothesised to be explained by expansion and the subsequent distortion caused by layer interaction during and after the printing process

    Prevalence of plasmodium falciparum in active conflict areas of eastern Burma: a summary of cross-sectional data

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    BACKGROUND: Burma records the highest number of malaria deaths in southeast Asia and may represent a reservoir of infection for its neighbors, but the burden of disease and magnitude of transmission among border populations of Burma remains unknown. METHODS: Plasmodium falciparum (Pf) parasitemia was detected using a HRP-II antigen based rapid test (Paracheck-Pf(R)). Pf prevalence was estimated from screenings conducted in 49 villages participating in a malaria control program, and four retrospective mortality cluster surveys encompassing a sampling frame of more than 220,000. Crude odds ratios were calculated to evaluate Pf prevalence by age, sex, and dry vs. rainy season. RESULTS: 9,796 rapid tests were performed among 28,410 villagers in malaria program areas through four years (2003: 8.4%, 95% CI: 8.3 - 8.6; 2004: 7.1%, 95% CI: 6.9 - 7.3; 2005:10.5%, 95% CI: 9.3 - 11.8 and 2006: 9.3%, 95% CI: 8.2 - 10.6). Children under 5 (OR = 1.99; 95% CI: 1.93 - 2.06) and those 5 to 14 years (OR = 2.24, 95% CI: 2.18 - 2.29) were more likely to be positive than adults. Prevalence was slightly higher among females (OR = 1.04, 95% CI: 1.02 - 1.06) and in the rainy season (OR = 1.48, 95% CI: 1.16 - 1.88). Among 5,538 rapid tests conducted in four cluster surveys, 10.2% were positive (range 6.3%, 95% CI: 3.9 - 8.8; to 12.4%, 95% CI: 9.4 - 15.4). CONCLUSION: Prevalence of plasmodium falciparum in conflict areas of eastern Burma is higher than rates reported among populations in neighboring Thailand, particularly among children. This population serves as a large reservoir of infection that contributes to a high disease burden within Burma and likely constitutes a source of infection for neighboring regions

    Pere Alberch's developmental morphospaces and the evolution of cognition

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    In this article we argue for an extension of Pere Alberch's notion of developmental morphospace into the realm of cognition and introduce the notion of cognitive phenotype as a new tool for the evolutionary and developmental study of cognitive abilities

    Influence of socioeconomic factors on pregnancy outcome in women with structural heart disease

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    OBJECTIVE: Cardiac disease is the leading cause of indirect maternal mortality. The aim of this study was to analyse to what extent socioeconomic factors influence the outcome of pregnancy in women with heart disease.  METHODS: The Registry of Pregnancy and Cardiac disease is a global prospective registry. For this analysis, countries that enrolled ≥10 patients were included. A combined cardiac endpoint included maternal cardiac death, arrhythmia requiring treatment, heart failure, thromboembolic event, aortic dissection, endocarditis, acute coronary syndrome, hospitalisation for cardiac reason or intervention. Associations between patient characteristics, country characteristics (income inequality expressed as Gini coefficient, health expenditure, schooling, gross domestic product, birth rate and hospital beds) and cardiac endpoints were checked in a three-level model (patient-centre-country).  RESULTS: A total of 30 countries enrolled 2924 patients from 89 centres. At least one endpoint occurred in 645 women (22.1%). Maternal age, New York Heart Association classification and modified WHO risk classification were associated with the combined endpoint and explained 37% of variance in outcome. Gini coefficient and country-specific birth rate explained an additional 4%. There were large differences between the individual countries, but the need for multilevel modelling to account for these differences disappeared after adjustment for patient characteristics, Gini and country-specific birth rate.  CONCLUSION: While there are definite interregional differences in pregnancy outcome in women with cardiac disease, these differences seem to be mainly driven by individual patient characteristics. Adjustment for country characteristics refined the results to a limited extent, but maternal condition seems to be the main determinant of outcome
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