2,219 research outputs found
Rapid and sensitive detection of Citrus Bacterial Canker by loop-mediated isothermal amplification combined with simple visual evaluation methods
<p>Abstract</p> <p>Background</p> <p>Citrus Bacterial Canker (CBC) is a major, highly contagious disease of citrus plants present in many countries in Asia, Africa and America, but not in the Mediterranean area. There are three types of Citrus Bacterial Canker, named A, B, and C that have different genotypes and posses variation in host range within citrus species. The causative agent for type A CBC is <it>Xanthomonas citri </it>subsp. <it>citri</it>, while <it>Xanthomonas fuscans </it>subsp. <it>aurantifolii</it>, strain B causes type B CBC and <it>Xanthomonas fuscans </it>subsp. <it>aurantifolii </it>strain C causes CBC type C. The early and accurate identification of those bacteria is essential for the protection of the citrus industry. Detection methods based on bacterial isolation, antibodies or polymerase chain reaction (PCR) have been developed previously; however, these approaches may be time consuming, laborious and, in the case of PCR, it requires expensive laboratory equipment. Loop-mediated isothermal amplification (LAMP), which is a novel isothermal DNA amplification technique, is sensitive, specific, fast and requires no specialized laboratory equipment.</p> <p>Results</p> <p>A loop-mediated isothermal amplification assay for the diagnosis of Citrus Bacterial Canker (CBC-LAMP) was developed and evaluated. DNA samples were obtained from infected plants or cultured bacteria. A typical ladder-like pattern on gel electrophoresis was observed in all positive samples in contrast to the negative controls. In addition, amplification products were detected by visual inspection using SYBRGreen and using a lateral flow dipstick, eliminating the need for gel electrophoresis. The sensitivity and specificity of the assay were evaluated in different conditions and using several sample sources which included purified DNA, bacterium culture and infected plant tissue. The sensitivity of the CBC-LAMP was 10 fg of pure <it>Xcc </it>DNA, 5 CFU in culture samples and 18 CFU in samples of infected plant tissue. No cross reaction was observed with DNA of other phytopathogenic bacteria. The assay was capable of detecting CBC-causing strains from several geographical origins and pathotypes.</p> <p>Conclusions</p> <p>The CBC-LAMP technique is a simple, fast, sensitive and specific method for the diagnosis of Citrus Bacterial Canker. This method can be useful in the phytosanitary programs of the citrus industry worldwide.</p
Whipple's Disease With Neurological Manifestations: Case Report.
Whipple's disease (WD) is an uncommon multisystem condition caused by the bacillus Tropheryma whipplei. Central nervous system involvement is a classical feature of the disease observed in 20 to 40% of the patients. We report the case of a 62 year old man with WD that developed neurological manifestations during its course, and discuss the most usual signs and symptoms focusing on recent diagnostic criteria and novel treatment regimens.62342-
New segregates from the Neotropical genus Stryphnodendron (Leguminosae, Caesalpinioideae, mimosoid clade)
Non-monophyly is a prominent issue in mimosoid legumes, even in some of the less speciose genera such as the neotropical genus Stryphnodendron. This genus includes 35 species occurring from Nicaragua to Southern Brazil mostly in humid forests and savannas. Previous taxonomic studies of Stryphnodendron have highlighted morphologically distinct groups within the genus, recognized by differences on leaves (number of pinnae and size of leaflets), inflorescences (a simple or compound thyrse), and fruit types (legume, nucoid legume or follicle). Recent phylogenetic analyses have confirmed the non-monophyly of Stryphnodendron, supporting the recognition of three independent and morphologically well-delimited genera. Here we re-circumscribe Stryphnodendron and propose the two new genera Gwilymia and Naiadendron. In addition, we also provide an updated taxonomic account of the closely related genus Microlobius, including the proposal of a lectotype for the single species in the genus
Validated outcome of treatment changes according to International League Against Epilepsy criteria in adults with drug-resistant focal epilepsy.
OBJECTIVE: Although many studies have attempted to describe treatment outcomes in patients with drug-resistant epilepsy, results are often limited by the adoption of nonhomogeneous criteria and different definitions of seizure freedom. We sought to evaluate treatment outcomes with a newly administered antiepileptic drug (AED) in a large population of adults with drug-resistant focal epilepsy according to the International League Against Epilepsy (ILAE) outcome criteria. METHODS: This is a multicenter, observational, prospective study of 1053 patients with focal epilepsy diagnosed as drug-resistant by the investigators. Patients were assessed at baseline and 6, 12, and 18 months, for up to a maximum of 34 months after introducing another AED into their treatment regimen. Drug resistance status and treatment outcomes were rated according to ILAE criteria by the investigators and by at least two independent members of an external expert panel (EP). RESULTS: A seizure-free outcome after a newly administered AED according to ILAE criteria ranged from 11.8% after two failed drugs to 2.6% for more than six failures. Significantly fewer patients were rated by the EP as having a "treatment failure" as compared to the judgment of the investigator (46.7% vs 62.9%, P < 0.001), because many more patients were rated as "undetermined outcome" (45.6% vs 27.7%, P < 0.001); 19.3% of the recruited patients were not considered drug-resistant by the EP. SIGNIFICANCE: This study validates the use of ILAE treatment outcome criteria in a real-life setting, providing validated estimates of seizure freedom in patients with drug-resistant focal epilepsy in relation to the number of previously failed AEDs. Fewer than one in 10 patients achieved seizure freedom on a newly introduced AED over the study period. Pseudo drug resistance could be identified in one of five cases
Median ages at stages of sexual maturity and excess weight in school children
Abstract: Background: We aimed to estimate the median ages at specific stages of sexual maturity stratified by excess weight in boys and girls. Materials and method. This was a cross-sectional study made in 2007 in Florianopolis, Brazil, with 2,339 schoolchildren between 8 to 14 years of age (1,107 boys) selected at random in two steps (by region and type of school). The schoolchildren were divided into: i) those with excess weight and ii) those without excess weight, according to the WHO 2007 cut-off points for gender and age. Sexual maturity was self-evaluated by the subjects according to the Tanner sexual development stages, and utilizing median ages for the genitalia, breasts, and pubic hair stages. Results: In the boys with excess weight, precocity was observed in the stages 4 for genitals and pubic hair and 2 for pubic hair, with the values for excess and normal weight. The median ages at the beginning of puberty (stage 2–sexual development) for boys and girls in Florianopolis were 10.8 and 10.3 years, respectively. Conclusion: Excess weight is associated with lower median ages in the sexual maturity stages in boys and girls and that it should be taken into account when evaluating sexual maturity in children and adolescents.The funding body provided financial support to make all procedures and in the decision to submit the manuscript for publication
Testing synchrotron models and frequency resolution in BINGO 21 cm simulated maps using GNILC
To recover the 21 cm hydrogen line, it is essential to separate the
cosmological signal from the much stronger foreground contributions at radio
frequencies. The BINGO radio telescope is designed to measure the 21 cm line
and detect BAOs using the intensity mapping technique. This work analyses the
performance of the GNILC method, combined with a power spectrum debiasing
procedure. The method was applied to a simulated BINGO mission, building upon
previous work from the collaboration. It compares two different synchrotron
emission models and different instrumental configurations, in addition to the
combination with ancillary data to optimize both the foreground removal and
recovery of the 21 cm signal across the full BINGO frequency band, as well as
to determine an optimal number of frequency bands for the signal recovery. We
have produced foreground emissions maps using the Planck Sky Model, the
cosmological Hi emission maps are generated using the FLASK package and thermal
noise maps are created according to the instrumental setup. We apply the GNILC
method to the simulated sky maps to separate the Hi plus thermal noise
contribution and, through a debiasing procedure, recover an estimate of the
noiseless 21 cm power spectrum. We found a near optimal reconstruction of the
Hi signal using a 80 bins configuration, which resulted in a power spectrum
reconstruction average error over all frequencies of 3%. Furthermore, our tests
showed that GNILC is robust against different synchrotron emission models.
Finally, adding an extra channel with CBASS foregrounds information, we reduced
the estimation error of the 21 cm signal. The optimisation of our previous
work, producing a configuration with an optimal number of channels for binning
the data, impacts greatly the decisions regarding BINGO hardware configuration
before commissioning.Comment: Submitted to A&
Cultura política de la democracia en Perú y en las Américas, 2014 : gobernabilidad democrática a través de 10 años del Barómetro de las Américas
El presente estudio es parte de un programa de investigaciones que el Proyecto de Opinión Pública de América Latina (LAPOP) viene llevando a cabo desde hace más de dos décadas. LAPOP es un consorcio de instituciones académicas y de investigación en las Américas, con sede central en Vanderbilt University, en Estados Unidos. En el proyecto LAPOP participan más de 30 instituciones de toda la región, cuyos esfuerzos tienen el propósito de producir estudios científicos, objetivos e independientes de opinión pública. Dichas investigaciones se enfocan principalmente en la medición de actitudes y comportamientos políticos relacionados con la democracia y la calidad de vida
Expanding tropical forest monitoring into Dry Forests: The DRYFLOR protocol for permanent plots
This is the final version. Available on open access from Wiley via the DOI in this recordSocietal Impact Statement
Understanding of tropical forests has been revolutionized by monitoring in permanent plots. Data from global plot networks have transformed our knowledge of forests’ diversity, function, contribution to global biogeochemical cycles, and sensitivity
to climate change. Monitoring has thus far been concentrated in rain forests. Despite
increasing appreciation of their threatened status, biodiversity, and importance to the
global carbon cycle, monitoring in tropical dry forests is still in its infancy. We provide
a protocol for permanent monitoring plots in tropical dry forests. Expanding monitoring into dry biomes is critical for overcoming the linked challenges of climate change,
land use change, and the biodiversity crisis.Newton FundNatural Environment Research Council (NERC)Fundação de Amparo à Pesquisa do Estado de São PauloCYTE
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