41 research outputs found

    Improved Method for In Vitro Secondary Amastigogenesis of Trypanosoma cruzi: Morphometrical and Molecular Analysis of Intermediate Developmental Forms

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    Trypanosoma cruzi undergoes a biphasic life cycle that consists of four alternate developmental stages. In vitro conditions to obtain a synchronic transformation and efficient rates of pure intermediate forms (IFs), which are indispensable for further biochemical, biological, and molecular studies, have not been reported. In the present study, we established an improved method to obtain IFs from secondary amastigogenesis. During the transformation kinetics, we observed progressive decreases in the size of the parasite body, undulating membrane and flagellum that were concomitant with nucleus remodeling and kinetoplast displacement. In addition, a gradual reduction in parasite movement and acquisition of the amastigote-specific Ssp4 antigen were observed. Therefore, our results showed that the in vitro conditions used obtained large quantities of highly synchronous and pure IFs that were clearly distinguished by morphometrical and molecular analyses. Obtaining these IFs represents the first step towards an understanding of the molecular mechanisms involved in amastigogenesis

    Research needs towards a resilient community: Vulnerability reduction, infrastructural systems model, loss assessment, resilience-based design and emergency management

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    Most of the literature on resilience is devoted to its assessment. It seems time to move from analysis to design, to develop the tools needed to enhance resilience. Resilience enhancement, a close relative of the less fashionable risk mitigation, adds to the latter, at least in the general perception, a systemic dimension. Resilience is often paired with community, and the latter is a system. This chapter therefore discusses strategies to enhance resilience, endorses one of prevention rather than cure, and focuses in the remainder on the role played by systemic analysis, i.e. the analysis of the built environment modelled beyond a simple collection of physical assets, with due care to the associated interdependencies. Research needs are identified and include challenges in network modelling, the replacement of generic fragility curves for components, how to deal with evolving state of information

    International nosocomial infection control consortium (INICC) report, data summary of 36 countries, for 2004-2009

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    The results of a surveillance study conducted by the International Nosocomial Infection Control Consortium (INICC) from January 2004 through December 2009 in 422 intensive care units (ICUs) of 36 countries in Latin America, Asia, Africa, and Europe are reported. During the 6-year study period, using Centers for Disease Control and Prevention (CDC) National Healthcare Safety Network (NHSN; formerly the National Nosocomial Infection Surveillance system [NNIS]) definitions for device-associated health care-associated infections, we gathered prospective data from 313,008 patients hospitalized in the consortium's ICUs for an aggregate of 2,194,897 ICU bed-days. Despite the fact that the use of devices in the developing countries' ICUs was remarkably similar to that reported in US ICUs in the CDC's NHSN, rates of device-associated nosocomial infection were significantly higher in the ICUs of the INICC hospitals; the pooled rate of central line-associated bloodstream infection in the INICC ICUs of 6.8 per 1,000 central line-days was more than 3-fold higher than the 2.0 per 1,000 central line-days reported in comparable US ICUs. The overall rate of ventilator-associated pneumonia also was far higher (15.8 vs 3.3 per 1,000 ventilator-days), as was the rate of catheter-associated urinary tract infection (6.3 vs. 3.3 per 1,000 catheter-days). Notably, the frequencies of resistance of Pseudomonas aeruginosa isolates to imipenem (47.2% vs 23.0%), Klebsiella pneumoniae isolates to ceftazidime (76.3% vs 27.1%), Escherichia coli isolates to ceftazidime (66.7% vs 8.1%), Staphylococcus aureus isolates to methicillin (84.4% vs 56.8%), were also higher in the consortium's ICUs, and the crude unadjusted excess mortalities of device-related infections ranged from 7.3% (for catheter-associated urinary tract infection) to 15.2% (for ventilator-associated pneumonia). Copyright © 2012 by the Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved

    Twist exome capture allows for lower average sequence coverage in clinical exome sequencing

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    Background Exome and genome sequencing are the predominant techniques in the diagnosis and research of genetic disorders. Sufficient, uniform and reproducible/consistent sequence coverage is a main determinant for the sensitivity to detect single-nucleotide (SNVs) and copy number variants (CNVs). Here we compared the ability to obtain comprehensive exome coverage for recent exome capture kits and genome sequencing techniques. Results We compared three different widely used enrichment kits (Agilent SureSelect Human All Exon V5, Agilent SureSelect Human All Exon V7 and Twist Bioscience) as well as short-read and long-read WGS. We show that the Twist exome capture significantly improves complete coverage and coverage uniformity across coding regions compared to other exome capture kits. Twist performance is comparable to that of both short- and long-read whole genome sequencing. Additionally, we show that even at a reduced average coverage of 70× there is only minimal loss in sensitivity for SNV and CNV detection. Conclusion We conclude that exome sequencing with Twist represents a significant improvement and could be performed at lower sequence coverage compared to other exome capture techniques

    Uncovering the heterogeneity of spatial lifeline system interdependencies

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    Lifeline systems are complex geographically distributed systems that are essential to the well-being of modern society and its response and recovery after natural disasters. For this reason, models of interdependent systems under a wide range of adverse events are emerging; nevertheless, it is not easy to assess the intensity of coupling across systems to make these models represent their actual behavior. Besides, this paper performs a systematic quantification of spatial interdependencies across multiple lifeline networks, including power, water, fixed telephone and internet systems, as representatives of modern smart infrastructures. The analysis expands a Kriging Aided Spatial Correlation Algorithm (KASCA) at the local scale that quantifies lifeline coupling strengths and provides a more explicit and reproducible formulation of the spatial approach. This is achieved by performing sensitivity analyses to best estimate the interdependence strengths across networks subjected to earthquakes across geographies that match predictions to field observations and local field features. The improved spatial analysis is applied for the first time to four systems in the context of the 2010 Mw 8.8 Chile Earthquake using utility restoration data sets and the results are compared with previous temporal and spatial analyses for subsets of the systems. Spatially varying coupling strengths resulting from this analysis are communicated via local correlation maps and synthesized into global correlation plots, which can point out interdependence directionality and length of coupling influence across lifeline systems. Addressing the spatial coupling behavior between networks is a crucial step towards modeling and robust quantification of the interdependencies between lifeline systems and associated facilities, while also supporting decision-makin

    The computational complexity of probabilistic Interdependent Network Design Problems

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    We present a rigorous study of the computational complexity of an Interdependent Network Design Problem (INDP) solution model, which is at the core of future infrastructure restoration studies. The paper details how each constraint in the INDP formulation adds to the overall complexity, while also revealing strategies to tame the computational demands for large interdependent networks. It is shown how some algorithms that are used to enhance the Network Design Problem (NDP) (Poss 2011), including decomposition techniques, can be cleverly adapted to the INDP model. Computational examples are based on diverse yet idealized topologies, to illustrate the sensitivity of the INDP model to input parameters and constraints, as well as the underlying topological properties of the studied systems. The present study paves the way for future approaches to improve the INDP and its Mixed-Integer Programming (MIP) model, particularly in terms of its efficiency and capability to handle large size instances, and by extension, its ability to support practical infrastructure decision making and resilience analyses.Non UBCUnreviewedThis collection contains the proceedings of ICASP12, the 12th International Conference on Applications of Statistics and Probability in Civil Engineering held in Vancouver, Canada on July 12-15, 2015. Abstracts were peer-reviewed and authors of accepted abstracts were invited to submit full papers. Also full papers were peer reviewed. The editor for this collection is Professor Terje Haukaas, Department of Civil Engineering, UBC Vancouver.Facult
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