67 research outputs found

    Latent Trait Analysis for Risk Management of Complex Information Technology Projects

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    Abstract-Recent years have seen a major increase in the application of predictive analytics to the service delivery domain as more and more service providers rely on such analytics for proactive risk management. At the pre-contract stage, identifying potential project risks accurately is of vital importance since it allows service providers to avoid profit erosion through proactive risk management. This paper describes a data-driven approach to project failure prediction of complex information technology (IT) projects. We introduce a novel theoretical framework of Latent Trait Analysis (LTA), whose original form was first developed in psychometrics. We take as the input questionnaire data of risk assessment reviews in the quality assurance (QA) process of IT projects before contract signing, and attempt to predict the project health in the delivery phase after contract signing. The idea is to explicitly capture the human cognitive process through LTA, and estimate the latent project failure tendency hidden behind the questionnaire answers collected by QA experts. Using real QA data of an IT service provider, we demonstrate that our approach outperforms existing approaches in project failure prediction while providing practical information on the usefulness of individual question items

    Frequency of sequence mutations and variants for the BRCA1 and BRCA2 genes in a sample of Colombian women with suspected hereditary breast cancer syndrome: case series

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    Objetivo: describir variantes de secuencia en los genes BRCA1 y BRCA2 en una muestra de pacien­tes colombianas con historia personal o familiar de cáncer de mama sugestiva de riesgo genético. Materiales y métodos: serie de casos compuesta por 67 pacientes que fueron remitidas para estu­dio genético por sospecha de síndrome de cáncer de mama y ovario hereditario (HBOC). De los 67 casos, 42 (62,7%) cumplieron con los criterios de indicación médica de la National Comprehensive Cancer Network (NCCN) del 2013, y en ellos se realizó secuenciación completa de los genes BRCA1 y BRCA2. Se determinó la frecuencia de mutación, variantes de secuencia y significancia clínica de las variantes halladas con base en Breast Cancer Informa-tion Core (BIC). Resultados: se identificaron mutaciones para el gen BRCA1 en seis pacientes (14,3%), no se docu­mentó mutación para el gen BRCA2, además se detectaron 43 variantes genéticas en 27 pacientes (64,2% de 42 casos). De estas, 21 (48,8%) fueron identificadas en el gen BRCA1 y 22 (51,2%) en el gen BRCA2.Dentro de estas variantes, se identi­ficaron 5 mutaciones patogénicas solo en el gen BRCA1, de las cuales solo una había sido reportada previamente en Colombia. Conclusiones: este estudio identifica variantes genéticas patogénicas en el gen BRCA1no descritas en estudios previos en la población colombiana y otras conocidas en diferentes poblaciones; permi­tiendo de esta forma ampliar el conocimiento sobre las variantes en población colombiana de los genes BRCA1 y BRCA2. Sin embargo, se requieren más es­tudios con suficiente poder y calidad metodológica para poder estimar la frecuencia de mutaciones y de variantes de secuencia para estos genes en mujeres colombianas con sospecha de síndrome de cáncer de mama u ovario hereditario.Objective: To describe sequence variants in the BRCA1 and BRCA2 genes in a sample of Colombian patients with a personal or family histor y of breast cancer suggestive of genetic risk. Materials and methods: Case series consisting of 67 patients referred for genetic testing because of suspected hereditar y breast and ovarian cancer syndrome (HBOC). Of the 67 cases, 42 (62.7%) met the medical indication criteria of the 2013 National Comprehensive Cancer Network (NCCN) and they were subjected to the entire sequencing of the BRCA1 and BRCA2 genes. A determination was made of the frequency of sequence mutation, variants, and of the clinical significance of the variants found based on the Breast Cancer Information Core (BIC). Results: Mutations were identified for the BRCA 1 gene in six patients (14.3%), no mutation was documented for the BRCA 2 gene, and 43 genetic variants were found in 27 patients (64.2% of 42 cases). Of these, 21 (48.8%) were identified in the BRCA1 gene and 22 (51.2%) in the BRCA 2 gene. Among these variants, 5 pathogenic mutations were found only in the BRCA1 gene and, of those, only 1 had been reported previously in Colombia.Conclusions: This study identifies pathogenic genetic variants in the BRCA1 gene not described previously in the Colombian population, as well as others known in different populations. Therefore, it helps expand knowledge regarding the variants of the BRCA1 and BRCA2 genes in the Colom­bian population. However, additional studies are required with sufficient power and methodologi­cal quality to estimate the frequency of sequence mutations and variants for the BRCA1 and BRCA2 genes in Colombian women suspected of having the hereditar y breast or ovarian cancer syndrome

    Spatial Models of Abundance and Habitat Preferences of Commerson’s and Peale’s Dolphin in Southern Patagonian Waters

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    Funding: This research was possible with the support of the Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET). Funding for travel to and accommodation for NAD in Aberdeen, Scotland was provided by CONICET and Cetacean Society International. The work of NAD was part of a postdoctoral fellowship funded by CONICET. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

    Histone Methylation by NUE, a Novel Nuclear Effector of the Intracellular Pathogen Chlamydia trachomatis

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    Sequence analysis of the genome of the strict intracellular pathogen Chlamydia trachomatis revealed the presence of a SET domain containing protein, proteins that primarily function as histone methyltransferases. In these studies, we demonstrated secretion of this protein via a type III secretion mechanism. During infection, the protein is translocated to the host cell nucleus and associates with chromatin. We therefore named the protein nuclear effector (NUE). Expression of NUE in mammalian cells by transfection reconstituted nuclear targeting and chromatin association. In vitro methylation assays confirmed NUE is a histone methyltransferase that targets histones H2B, H3 and H4 and itself (automethylation). Mutants deficient in automethylation demonstrated diminished activity towards histones suggesting automethylation functions to enhance enzymatic activity. Thus, NUE is secreted by Chlamydia, translocates to the host cell nucleus and has enzymatic activity towards eukaryotic substrates. This work is the first description of a bacterial effector that directly targets mammalian histones

    Autoimmunity in Arabidopsis acd11 Is Mediated by Epigenetic Regulation of an Immune Receptor

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    Certain pathogens deliver effectors into plant cells to modify host protein targets and thereby suppress immunity. These target modifications can be detected by intracellular immune receptors, or Resistance (R) proteins, that trigger strong immune responses including localized host cell death. The accelerated cell death 11 (acd11) “lesion mimic” mutant of Arabidopsis thaliana exhibits autoimmune phenotypes such as constitutive defense responses and cell death without pathogen perception. ACD11 encodes a putative sphingosine transfer protein, but its precise role during these processes is unknown. In a screen for lazarus (laz) mutants that suppress acd11 death we identified two genes, LAZ2 and LAZ5. LAZ2 encodes the histone lysine methyltransferase SDG8, previously shown to epigenetically regulate flowering time via modification of histone 3 (H3). LAZ5 encodes an RPS4-like R-protein, defined by several dominant negative alleles. Microarray and chromatin immunoprecipitation analyses showed that LAZ2/SDG8 is required for LAZ5 expression and H3 lysine 36 trimethylation at LAZ5 chromatin to maintain a transcriptionally active state. We hypothesize that LAZ5 triggers cell death in the absence of ACD11, and that cell death in other lesion mimic mutants may also be caused by inappropriate activation of R genes. Moreover, SDG8 is required for basal and R protein-mediated pathogen resistance in Arabidopsis, revealing the importance of chromatin remodeling as a key process in plant innate immunity

    The Rac GTP Exchange Factor TIAM-1 Acts with CDC-42 and the Guidance Receptor UNC-40/DCC in Neuronal Protrusion and Axon Guidance

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    The mechanisms linking guidance receptors to cytoskeletal dynamics in the growth cone during axon extension remain mysterious. The Rho-family GTPases Rac and CDC-42 are key regulators of growth cone lamellipodia and filopodia formation, yet little is understood about how these molecules interact in growth cone outgrowth or how the activities of these molecules are regulated in distinct contexts. UNC-73/Trio is a well-characterized Rac GTP exchange factor in Caenorhabditis elegans axon pathfinding, yet UNC-73 does not control CED-10/Rac downstream of UNC-6/Netrin in attractive axon guidance. Here we show that C. elegans TIAM-1 is a Rac-specific GEF that links CDC-42 and Rac signaling in lamellipodia and filopodia formation downstream of UNC-40/DCC. We also show that TIAM-1 acts with UNC-40/DCC in axon guidance. Our results indicate that a CDC-42/TIAM-1/Rac GTPase signaling pathway drives lamellipodia and filopodia formation downstream of the UNC-40/DCC guidance receptor, a novel set of interactions between these molecules. Furthermore, we show that TIAM-1 acts with UNC-40/DCC in axon guidance, suggesting that TIAM-1 might regulate growth cone protrusion via Rac GTPases in response to UNC-40/DCC. Our results also suggest that Rac GTPase activity is controlled by different GEFs in distinct axon guidance contexts, explaining how Rac GTPases can specifically control multiple cellular functions

    Epigenetic regulation of mucin genes in human cancers

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    Mucins are high molecular weight glycoproteins that play important roles in diagnostic and prognostic prediction and in carcinogenesis and tumor invasion. Regulation of expression of mucin genes has been studied extensively, and signaling pathways, transcriptional regulators, and epigenetic modification in promoter regions have been described. Detection of the epigenetic status of cancer-related mucin genes is important for early diagnosis of cancer and for monitoring of tumor behavior and response to targeted therapy. Effects of micro-RNAs on mucin gene expression have also started to emerge. In this review, we discuss the current views on epigenetic mechanisms of regulation of mucin genes (MUC1, MUC2, MUC3A, MUC4, MUC5AC, MUC5B, MUC6, MUC16, and MUC17) and the possible clinical applications of this epigenetic information

    A multi-country study of intussusception in children under 2 years of age in Latin America: analysis of prospective surveillance data

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    BACKGROUND: Intussusception (IS) is a form of acute intestinal obstruction that occurs mainly in infants and is usually of unknown cause. An association between IS and the first licensed rotavirus vaccine, a reassortant-tetravalent, rhesus-based rotavirus vaccine (RRV-TV), led to the withdrawal of the vaccine. New rotavirus vaccines have now been developed and extensively studied for their potential association with IS. This study aimed to describe the epidemiology and to estimate the incidence of IS in Latin American infants prior to new vaccine introduction. METHODS: Children under 2 years of age representing potential IS cases were enrolled in 16 centers in 11 Latin American countries from January 2003 to May 2005. IS cases were classified as definite, probable, possible or suspected as stated on the Brighton Collaboration Working Group guidelines. RESULTS: From 517 potential cases identified, 476 (92%) cases were classified as definite, 21 probable, 10 possible and 10 suspected for intussusception. Among the 476 definite IS cases, the median age at presentation was 6.4 months with 89% of cases aged <1 year. The male to female ratio was 1.5:1. The incidence of definite IS per 100,000 subject-years ranged from 1.9 in Brazil to 62.4 in Argentina for children <2 years of age, and from 3.8 in Brazil to 105.3 in Argentina for children aged <1 year. Median hospital stay was 4 days with a high prevalence of surgery as the primary treatment (65%). Most cases (88%) made a complete recovery, but 13 (3%) died. No clear seasonal pattern of IS cases emerged. CONCLUSIONS: This study describes the epidemiology and estimates the incidence of IS in Latin American infants prior to the introduction of new rotavirus vaccines. The incidence of IS was found to vary between different countries, as observed in previous studies. TRIAL REGISTRATION: Clinical study identifier 999910/204 (SERO-EPI-IS-204
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