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1.
Plant Dis ; 108(1): 149-161, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37578368

RESUMEN

Cercospora leaf blight (CLB) of soybean, caused by Cercospora cf. flagellaris, C. kikuchii, and C. cf. sigesbeckiae, is an economically important disease in the southern United States. Cultivar resistance to CLB is inconsistent; therefore, fungicides in the quinone outside inhibitor (QoI) class have been relied on to manage the disease. Approximately 620 isolates from plants exhibiting CLB were collected between 2018 and 2021 from 19 locations in eight southern states. A novel polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay based on two genes, calmodulin and histone h3, was developed to differentiate between the dominant species of Cercospora, C. cf. flagellaris, and C. cf. sigesbeckiae. A multilocus phylogenetic analysis of actin, calmodulin, histone h3, ITS rDNA, and transcription elongation factor 1-α was used to confirm PCR-RFLP results and identify remaining isolates. Approximately 80% of the isolates collected were identified as C. cf. flagellaris, while 15% classified as C. cf. sigesbeckiae, 2% as C. kikuchii, and 3% as previously unreported Cercospora species associated with CLB in the United States. PCR-RFLP of cytochrome b (cytb) identified QoI-resistance conferred by the G143A substitution. Approximately 64 to 83% of isolates were determined to be QoI-resistant, and all contained the G143A substitution. Results of discriminatory dose assays using azoxystrobin (1 ppm) were 100% consistent with PCR-RFLP results. To our knowledge, this constitutes the first report of QoI resistance in CLB pathogen populations from Alabama, Arkansas, Kentucky, Mississippi, Missouri, Tennessee, and Texas. In areas where high frequencies of resistance have been identified, QoI fungicides should be avoided, and fungicide products with alternative modes-of-action should be utilized in the absence of CLB-resistant soybean cultivars.


Asunto(s)
Ascomicetos , Fungicidas Industriales , Estados Unidos , Fungicidas Industriales/farmacología , Cercospora , Glycine max , Filogenia , Calmodulina/genética , Histonas/genética , Arkansas , Quinonas
2.
J Extra Corpor Technol ; 55(2): 53-59, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37378437

RESUMEN

BACKGROUND: Simulator training is important for teaching perfusion students fundamental skills associated with CBP before they start working in the clinic. Currently available high-fidelity simulators lack anatomic features that would help students visually understand the connection between hemodynamic parameters and anatomic structure. Therefore, a 3D-printed silicone cardiovascular system was developed at our institution. This study aimed to determine whether using this anatomic perfusion simulator instead of a traditional "bucket" simulator would better improve perfusion students' understanding of cannulation sites, blood flow, and anatomy. METHODS: Sixteen students were tested to establish their baseline knowledge. They were randomly divided into two groups to witness a simulated bypass pump run on one of two simulators - anatomic or bucket - then retested. To better analyze the data, we defined "true learning" as characterized by an incorrect answer on the pre-simulation assessment being corrected on the post-simulation assessment. RESULTS: The group that witnessed the simulated pump run on the anatomic simulator showed a larger increase in mean test score, more instances of true learning, and a larger gain in the acuity confidence interval. CONCLUSIONS: Despite the small sample size, the results suggest that the anatomic simulator is a valuable instrument for teaching new perfusion students.


Asunto(s)
Puente Cardiopulmonar , Aprendizaje , Humanos , Impresión Tridimensional , Competencia Clínica
3.
Mycologia ; 113(2): 326-347, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33555993

RESUMEN

Taproot decline (TRD) is a disease of soybean that has been reported recently from the southern United States (U.S.). Symptoms of TRD include foliar interveinal chlorosis followed by necrosis. Darkened, charcoal-colored areas of thin stromatic tissue are evident on the taproot and lateral roots along with areas of necrosis within the root and white mycelia within the pith. Upright stromata typical of Xylaria can be observed on crop debris and emerging from infested roots in fields where taproot decline is present, but these have not been determined to contain fertile perithecia. Symptomatic plant material was collected across the known range of the disease in the southern U.S., and the causal agent was isolated from roots. Four loci, ⍺-actin (ACT), ß-tubulin (TUB2), the nuclear rDNA internal transcribed spacers (nrITS), and the RNA polymerase subunit II (RPB2), were sequenced from representative isolates. Both maximum likelihood and Bayesian phylogenetic analyses showed consistent clustering of representative TRD isolates in a highly supported clade within the Xylaria arbuscula species complex in the "HY" clade of the family Xylariaceae, distinct from any previously described taxa. In order to understand the origin of this pathogen, we sequenced herbarium specimens previously determined to be "Xylaria arbuscula" based on morphology and xylariaceous endophytes collected in the southern U.S. Some historical specimens from U.S. herbaria collected in the southern region as saprophytes as well as a single specimen from Martinique clustered within the "TRD" clade in phylogenetic analyses, suggesting a possible shift in lifestyle. The remaining specimens that clustered within the family Xylariaceae, but outside of the "TRD" clade, are reported. Both morphological evidence and molecular evidence indicate that the TRD pathogen is a novel species, which is described as Xylaria necrophora.


Asunto(s)
Glycine max/microbiología , Enfermedades de las Plantas/microbiología , Raíces de Plantas/microbiología , Xylariales/genética , Xylariales/patogenicidad , Teorema de Bayes , ADN de Hongos/genética , ADN Ribosómico/genética , Variación Genética , Filogenia , Estados Unidos , Xylariales/clasificación
4.
PLoS One ; 14(10): e0222901, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31581244

RESUMEN

The main purpose of this study was to explore the potential influences of pickleweed vegetation on the abundance, diversity and metabolic activities of microbial communities in four distinct areas of a petroleum-contaminated solid waste management unit (SWMU) located in Contra Costa County, northern California. The four areas sampled include two central areas, one of which is central vegetated (CV) and one unvegetated (UV), and two peripheral vegetated areas, one of which is located to the west side of the SWMU (V-West) and one located to the east side (V-East). Measurements were made of total petroleum hydrocarbons (TPH), polyaromatic hydrocarbons (PAH), soil physicochemical properties, and various aspects of microbial communities including metabolic activities, microbial abundances (PLFAs), diversity and composition based on amplicon sequencing. The peripheral V-East and V-West sites had 10-times lower electrical conductivity (EC) than that of the CV and UV sites. The high salinity levels of the CV and UV sites were associated with significant reductions in bacterial and fungal abundances (PLFA) when compared to V-East but not when compared to V-West. TPH levels of CV and UV were not significantly different from those of V-West but were substantially lower than V-East TPH (19,311 mg/kg of dry soil), the high value of which may have been associated with a pipeline that ran through the area. Microbial activities (in terms of soil respiration and the activities of three soil enzymes, i.e., urease, lipase, and phosphatase) were greatest in the vegetated sites compared to the UV site. The prokaryotic community was not diverse as revealed by the Shannon index with no significant variation among the four groups of samples. However, the fungal community of the peripheral sites, V-East and V-West had significantly higher OTU richness and Shannon index. Structure of prokaryotic communities inhabiting the rhizosphere of pickleweed plants at the three sites differed significantly and were also different from those found in the UV region of the central site according to pairwise, global PERMANOVA and ANOSIM analyses. The differences in OTU-based rhizosphere-associated bacterial and fungal communities' composition were explained mainly by the changes in soil EC and pH. The results suggest that saline TPH-contaminated areas that are vegetated with pickleweed are likely to have increased abundances, diversity and metabolic activities in the rhizosphere compared to unvegetated areas, even in the presence of high salinity.


Asunto(s)
Chenopodiaceae/fisiología , Hidrocarburos/análisis , Microbiota , Petróleo/análisis , Raíces de Plantas/microbiología , Salinidad , Residuos Sólidos/análisis , Administración de Residuos , Biodiversidad , California , Contaminación Ambiental/análisis , Geografía , Suelo/química , Microbiología del Suelo
5.
Geosci Data J ; 5(1): 4-8, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30443346

RESUMEN

This report provides a detailed set of historical stressor data for 60 watersheds comprising the Laurentian Great Lakes basin. Archival records were transcribed from public records to create quantitative data on human activities: population, mining, deforestation, and agriculture. Yearly records of stressors are provided from 1780 through 2010. These data may be used to track historical impacts on Great Lakes coastal and open water conditions. They may further be used to examine corresponding effects on response variables such as biological communities quantified during monitoring and palaeoecological programmes. OPEN PRACTICES: This article has earned an Open Data badge for making publicly available the digitally-shareable data necessary to reproduce the reported results. The data is available at https://doi.org/10.1594/PANGAEA.885879. Learn more about the Open Practices badges from the Center for Open Science: https://osf.io/tvyxz/wiki.

6.
Environ Monit Assess ; 190(10): 580, 2018 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-30203154

RESUMEN

Biotic indicators are useful for assessing ecosystem health because the structure of resident communities generally reflects abiotic conditions integrated over time. We used fish data collected over 5 years for 470 Great Lakes coastal wetlands to develop multi-metric indices of biotic integrity (IBI). Sampling and IBI development were stratified by vegetation type within each wetland to account for differences in physical habitat. Metrics were evaluated against numerous indices of anthropogenic disturbance derived from water quality and surrounding land-cover variables. Separate datasets were used for IBI development and testing. IBIs were composed of 10-11 metrics for each of four vegetation types (bulrush, cattail, water lily, and submersed aquatic vegetation). Scores of all IBIs correlated well with disturbance indices using the development data, and the accuracy of our IBIs was validated using the testing data. Our fish IBIs can be used to prioritize wetland protection and restoration efforts across the Great Lakes basin. The IBIs will also be useful in monitoring programs mandated by the Agreement between Canada and the United States of America on Great Lakes Water Quality, such as for assessing Beneficial Use Impairments (BUIs) in Great Lakes Areas of Concern, and in other ecosystem management programs in Canada and the USA.


Asunto(s)
Monitoreo del Ambiente , Peces , Humedales , Animales , Biodiversidad , Aves , Canadá , Ecología , Ecosistema , Lagos , Estados Unidos , Calidad del Agua
8.
Phys Plasmas ; 24(5): 056702, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28652684

RESUMEN

Laser-plasma interactions in the novel regime of relativistically induced transparency (RIT) have been harnessed to generate intense ion beams efficiently with average energies exceeding 10 MeV/nucleon (>100 MeV for protons) at "table-top" scales in experiments at the LANL Trident Laser. By further optimization of the laser and target, the RIT regime has been extended into a self-organized plasma mode. This mode yields an ion beam with much narrower energy spread while maintaining high ion energy and conversion efficiency. This mode involves self-generation of persistent high magnetic fields (∼104 T, according to particle-in-cell simulations of the experiments) at the rear-side of the plasma. These magnetic fields trap the laser-heated multi-MeV electrons, which generate a high localized electrostatic field (∼0.1 T V/m). After the laser exits the plasma, this electric field acts on a highly structured ion-beam distribution in phase space to reduce the energy spread, thus separating acceleration and energy-spread reduction. Thus, ion beams with narrow energy peaks at up to 18 MeV/nucleon are generated reproducibly with high efficiency (≈5%). The experimental demonstration has been done with 0.12 PW, high-contrast, 0.6 ps Gaussian 1.053 µm laser pulses irradiating planar foils up to 250 nm thick at 2-8 × 1020 W/cm2. These ion beams with co-propagating electrons have been used on Trident for uniform volumetric isochoric heating to generate and study warm-dense matter at high densities. These beam plasmas have been directed also at a thick Ta disk to generate a directed, intense point-like Bremsstrahlung source of photons peaked at ∼2 MeV and used it for point projection radiography of thick high density objects. In addition, prior work on the intense neutron beam driven by an intense deuterium beam generated in the RIT regime has been extended. Neutron spectral control by means of a flexible converter-disk design has been demonstrated, and the neutron beam has been used for point-projection imaging of thick objects. The plans and prospects for further improvements and applications are also discussed.

9.
Pharmacoeconomics ; 34(3): 273-84, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26589411

RESUMEN

BACKGROUND: Although efficient designs have sample size advantages for discrete choice experiments (DCEs), it has been hypothesised that they may result in biased estimates owing to some respondents using simplistic heuristics. OBJECTIVES: The main objective was to provide a case study documenting that many respondents choose on the basis of a single attribute when exposed to highly efficient DCE designs but switch to a conventional multi-attribute decision rule when the design efficiency was lowered (resulting in less need to trade across all attributes). Additional objectives included comparisons of the sizes of the estimated coefficients and characterisation of heterogeneity, thus providing evidence of the magnitude of bias likely present in highly efficient designs. METHODS: Five hundred and twenty-five respondents participating in a wider end-of-life survey each answered two DCEs that varied in their design efficiency. The first was a Street and Burgess 100% efficient Orthogonal Main Effects Plan design (2(7) in 8), using the top and bottom levels of all attributes. The second DCE comprised one eighth of the full Orthogonal Main Effects Plan in 32 pairs, (a 2 × 4(6)). Linear probability models estimated every respondent's complete utility function in DCE1. The number of respondents answering on the basis of one attribute level was noted, as was the proportion of these who then violated this rule in DCE2, the less efficient DCE. Latent class analyses were used to identify heterogeneity. RESULTS: Sixty per cent of respondents answered all eight tasks comprising DCE1 using a single attribute; most used the rule "choose cheapest end-of-life care plan". However, when answering the four less efficient tasks in DCE2, one third of these (20% overall) then traded across attributes at least once. Among those whose decision rule could not be described qualitatively, latent class models identified two classes; compared to class one, class two was more concerned with quality rather than cost of care and wished to die in an institution rather than at home. Higher efficiency was also associated with smaller regression coefficients, suggesting either weaker preferences or lower choice consistency (larger errors). CONCLUSION: This is the first within-subject study to investigate the association between DCE design efficiency and utility estimates. It found that a majority of people did not trade across attributes in the more efficient design but that one third of these then did trade in the less efficient design. More within-subject studies are required to establish how common this is. It may be that future DCEs should attempt to maximise some joint function of statistical and cognitive efficiency to maximise overall efficiency and minimise bias.


Asunto(s)
Conducta de Elección , Prioridad del Paciente/psicología , Proyectos de Investigación , Cuidado Terminal/economía , Cuidado Terminal/psicología , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Modelos Estadísticos
10.
Health Policy ; 119(11): 1482-9, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26421597

RESUMEN

Singapore is in the midst of several healthcare reforms in efforts to finance and deliver health services for a rapidly aging population. The primary focus of these reforms is to make healthcare services, including those at the end of life (EOL), affordable. Given the increasingly high health care costs at the EOL, policy makers need to consider how best to allocate resources. One strategy is to allocate resources based on the preferences of sub-populations most likely to be affected. This paper thus aims to quantify preferences for EOL care both among community dwelling older adults (CDOAs) and among patients with a life-limiting illness. A discrete choice experiment was administered to CDOAs and advanced cancer patients in Singapore and willingness to pay (WTP) for specific EOL improvements was estimated. We find that patients have a higher WTP for nearly all EOL attributes compared with CDOAs. We also show that, for both groups, moderate life extension is not the most important consideration; WTP for one additional life year is lower than common thresholds for cost-effectiveness. Irrespective of whose preference are considered, the results highlight the importance of pain management and supporting home deaths at the EOL, perhaps at the expense of public funding for costly but only marginally effective treatments.


Asunto(s)
Neoplasias/patología , Prioridad del Paciente , Cuidado Terminal , Conducta de Elección , Femenino , Financiación Personal , Humanos , Masculino , Persona de Mediana Edad , Singapur , Encuestas y Cuestionarios
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