246 research outputs found

    Development and validation of a real-time quantitative PCR assay for the detection and quantification of Perkinsus marinus in the Eastern oyster, Crassostrea virginica

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    Author Posting. © National Shellfisheries Association, 2009. This article is posted here by permission of National Shellfisheries Association for personal use, not for redistribution. The definitive version was published in Journal of Shellfish Research 28 (2009): 459-464, doi:10.2983/035.028.0306.Perkinus marinus causes a devastating disease, known as Dermo, in the Eastern oyster Crassostrea virginica. Routine detection of the disease is traditionally accomplished by the use of the Ray/Makin assay, using Fluid Thioglycollate Medium (RFTM). A simple real-time quantitative PCR assay was developed as a diagnostic tool to detect and quantify P. marinus, to complement and serve as an alternate to the RFTM method. Using a dual-labeled probe approach, a sensitive assay was designed to accurately detect a range of one to several thousand P. marinus organisms present in oyster tissues. A simple extraction method was used to increase throughput of the assay. Cultured P. marinus cells were quantified prior to DNA extraction, generating a standard curve and allowing cell counts to be derived from PCR cycle threshold values. Direct comparison of the RFTM and real-time PCR methods was accomplished by using tissue samples from the same oyster for both tests. Plotting cycle threshold values against the known Mackin index value generated a standard curve with a coefficient of regression of 0.9. Our results indicate that correlations could be made between this molecular based approach and traditional methods, allowing results generated from the PCR assay to be easily translated into the understood Mackin scale

    Routine delivery of artemisinin-based combination treatment at fixed health facilities reduces malaria prevalence in Tanzania: an observational study

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    BACKGROUND Artemisinin-based combination therapy (ACT) has been promoted as a means to reduce malaria transmission due to their ability to kill both asexual blood stages of malaria parasites, which sustain infections over long periods and the immature derived sexual stages responsible for infecting mosquitoes and onward transmission. Early studies reported a temporal association between ACT introduction and reduced malaria transmission in a number of ecological settings. However, these reports have come from areas with low to moderate malaria transmission, been confounded by the presence of other interventions or environmental changes that may have reduced malaria transmission, and have not included a comparison group without ACT. This report presents results from the first large-scale observational study to assess the impact of case management with ACT on population-level measures of malaria endemicity in an area with intense transmission where the benefits of effective infection clearance might be compromised by frequent and repeated re-infection. METHODS A pre-post observational study with a non-randomized comparison group was conducted at two sites in Tanzania. Both sites used sulphadoxine-pyrimethamine (SP) monotherapy as a first-line anti-malarial from mid-2001 through 2002. In 2003, the ACT, artesunate (AS) co-administered with SP (AS + SP), was introduced in all fixed health facilities in the intervention site, including both public and registered non-governmental facilities. Population-level prevalence of Plasmodium falciparum asexual parasitaemia and gametocytaemia were assessed using light microscopy from samples collected during representative household surveys in 2001, 2002, 2004, 2005 and 2006. FINDINGS Among 37,309 observations included in the analysis, annual asexual parasitaemia prevalence in persons of all ages ranged from 11% to 28% and gametocytaemia prevalence ranged from <1% to 2% between the two sites and across the five survey years. A multivariable logistic regression model was fitted to adjust for age, socioeconomic status, bed net use and rainfall. In the presence of consistently high coverage and efficacy of SP monotherapy and AS + SP in the comparison and intervention areas, the introduction of ACT in the intervention site was associated with a modest reduction in the adjusted asexual parasitaemia prevalence of 5 percentage-points or 23% (p < 0.0001) relative to the comparison site. Gametocytaemia prevalence did not differ significantly (p = 0.30). INTERPRETATION The introduction of ACT at fixed health facilities only modestly reduced asexual parasitaemia prevalence. ACT is effective for treatment of uncomplicated malaria and should have substantial public health impact on morbidity and mortality, but is unlikely to reduce malaria transmission substantially in much of sub-Saharan Africa where individuals are rapidly re-infected.Financial support for IMPACT-Tz came primarily from CDC, the U.S. Agency for International Development and the Wellcome Trust

    Malaria chemoprophylaxis and the serologic response to measles and diphtheria-tetanus-whole-cell pertussis vaccines

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    BACKGROUND: Acute malaria has been associated with a decreased antibody response to tetanus and diphtheria toxoids, meningococcal, salmonella, and Hib vaccines. Interest in giving malaria drug therapy and prevention at the time of childhood immunizations has increased greatly following recent trials of intermittent preventive therapy during infancy (IPTi), stimulating this re-analysis of unpublished data. The effect of malaria chemoprophylaxis on vaccine response was studied following administration of measles vaccines and diphtheria-tetanus-whole cell pertussis (DTP) vaccines. METHODS: In 1975, six villages divided into two groups of children ≤74 months of age from Burkina Faso, were assigned to receive amodiaquine hydrochloride chemoprophylaxis (CH+) every two weeks for seven months or no chemoprophylaxis (CH-). After five months, children in each group received either one dose of measles or two doses of DTP vaccines. RESULTS: For recipients of the measles vaccine, the seroconversion rates in CH+ and CH- children, respectively, were 93% and 96% (P > 0.05). The seroresponse rates in CH+ and CH- children respectively, were 73% and 86% for diphtheria (P > 0.05) and 77% and 91% for tetanus toxoid (P > 0.05). In a subset analysis, in which only children who strictly adhered to chemoprophylaxis criteria were included, there were, likewise, no significant differences in seroconversion or seroresponse for measles, diphtheria, or tetanus vaccines (P > 0.05). While analysis for pertussis showed a 43% (CH+) and 67% (CH-) response (P < 0.05), analyses using logistic regression to control for sex, age, chemoprophylaxis, weight-for-height Z-score, and pre-vaccination geometric mean titer (GMT), demonstrated that chemoprophylaxis was not associated with a significantly different conversion rate following DTP and measles vaccines. Seven months of chemoprophylaxis decreased significantly the malaria IFA and ELISA GMTs in the CH+ group. CONCLUSION: Malaria chemoprophylaxis prior to vaccination in malaria endemic settings did not improve or impair immunogenicity of DTP and measles vaccines. This is the first human study to look at the association between malaria chemoprophylaxis and the serologic response to whole-cell pertussis vaccine

    Information findability on sites that promote open data

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    The work is designed for sites that promote open data, seeking to reflect whether characteristics of information findability are being considered, providing users with alternatives to easily find data and information according to their needs. The aim of the study is to identify the status of attributes of information findability and its similarities in assessments of three sites created to promote the availability of open data: Open Government Partnership (OGP), Global Open Data for Agriculture & Nutrition (GODAN), and International Open Data Conference (IODC). The comparative analysis is performed with the checklist for the Evaluation of Hybrid Informational Environments, proceeding with a horizontal relationship for each of the attributes. For the three sites, the variables of the attributes generally behaved in a homogeneous way, however, there is a high variability in the values ​​obtained when applying the instrument, pointing out that the unsatisfied variables added to the partially satisfied ones, total a value significantly greater than the satisfied variables, being that only the Navigational Taxonomies, Ubiquity, Consistency and Correlation attributes had a predominance of variables with satisfied evaluations. In the analyzed websites, it is feasible to evaluate attributes of information findability such as those of the instrument, and, in the context of open data promotion strategies, the little relevance given to mediation of information is emphasized, both from institutional informational subjects and from subjects informational target of the analyzed initiatives. The need to continue evaluations of this nature is emphasized, with special attention to attributes such as Terminological Control Instruments and procedures to identify the existence of Controlled Vocabularies, Thesaurus and other Ontological Elements.O trabalho está delimitado a sites que promovem dados abertos, buscando refletir se características da encontrabilidade da informação estão sendo consideradas, proporcionando aos usuários alternativas para encontrar facilmente dados e informações conforme as suas necessidades. O objetivo do estudo é identificar o estado de atributos da encontrabilidade da informação e suas semelhanças em avaliações a três sites criados para promover a disponibilização de dados abertos: Open Government Partnership (OGP), Global Open Data for Agriculture & Nutrition (GODAN), e International Open Data Conference (IODC). A análise comparativa é realizada com o instrumento Checklist para Avaliação de Ambientes Informacionais Híbridos, procedendo com um relacionamento horizontal para cada um dos atributos. Para os três sites, as variáveis dos atributos comportaram-se no geral de forma homogênea, contudo, percebe-se uma alta variabilidade nos valores obtidos ao aplicar o instrumento, assinalando que as variáveis não satisfeitas somadas às parcialmente satisfeitas, totalizam um valor significativamente maior que as variáveis satisfeitas, sendo que, somente os atributos Taxonomias Navegacionais, Ubiquidade, Consistência e Correlação, tiveram predominância de variáveis com avaliações satisfeitas. Nos sites analisados é factível a avaliação de atributos da encontrabilidade da informação como os do instrumento, e, no contexto de estratégias de promoção de dados abertos, ressalta-se a pouca relevância dada à mediação da informação, tanto de sujeitos informacionais institucionais quanto de sujeitos informacionais alvo das iniciativas analisadas. Salienta-se a necessidade de continuidade de avaliações desta natureza, com especial atenção em atributos como Instrumentos de Controle Terminológico e em procedimentos para identificar a existência de Vocabulários Controlados, Tesauros e outros Elementos Ontológicos.Facultad de Humanidades y Ciencias de la Educació

    UPC++ Specification v1.0, Draft 4

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    This document has been superseded by: UPC++ Specification v1.0, Draft 6 (LBNL-2001135) https://escholarship.org/uc/item/82094433 UPC++ is a C++11 library providing classes and functions that support Asynchronous Partitioned Global Address Space (APGAS) programming. We are revising the library under the auspices of the DOE’s Exascale Computing Project, to meet the needs of applications requiring PGAS support. UPC++ is intended for implementing elaborate distributed data structures where communication is irregular or fine-grained. The UPC++ interfaces for moving non-contiguous data and handling memories with different optimal access methods are composable and similar to those used in conventional C++. The UPC++ programmer can expect communication to run at close to hardware speeds. The key facilities in UPC++ are global pointers, that enable the programmer to express ownership information for improving locality, one-sided communication, both put/get and RPC, futures and continuations. Futures capture data readiness state, which is useful in making scheduling decisions, and continuations provide for completion handling via callbacks. Together, these enable the programmer to chain together a DAG of operations to execute asynchronously as high-latency dependencies become satisfied

    Analysis and annotation of DNA methylation in two nonhuman primate species using the Infinium Human Methylation 450K and EPIC BeadChips

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    Aim: Nonhuman primates are essential for research on many human diseases. The Infinium Human Methylation450/EPIC BeadChips are popular tools for the study of the methylation state across the human genome at affordable cost. Methods: We performed a precise evaluation and re-annotation of the BeadChip probes for the analysis of genome-wide DNA methylation patterns in rhesus macaques and African green monkeys through in silico analyses combined with functional validation by pyrosequencing. Results: Up to 165,847 of the 450K and 261,545 probes of the EPIC BeadChip can be reliably used. The annotation files are provided in a format compatible with a variety of standard bioinformatic pipelines. Conclusion: Our study will facilitate high-throughput DNA methylation analyses in Macaca mulatta and Chlorocebus sabaeus.Host-parasite interactio
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