56 research outputs found

    Brucella exposure risk events in 10 clinical laboratories, New York City, USA, 2015 to 2017

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    Copyright © 2020 American Society for Microbiology. All Rights Reserved. From 2015 to 2017, 11 confirmed brucellosis cases were reported in New York City, leading to 10 Brucella exposure risk events (Brucella events) in 7 clinical laboratories (CLs). Most patients had traveled to countries where brucellosis is endemic and presented with histories and findings consistent with brucellosis. CLs were not notified that specimens might yield a hazardous organism, as the clinicians did not consider brucellosis until they were notified that bacteremia with Brucella was suspected. In 3 Brucella events, the CLs did not suspect that slow-growing, small Gram-negative bacteria might be harmful. Matrix-assisted laser desorption ionization- time of flight mass spectrometry (MALDI-TOF MS), which has a limited capacity to identify biological threat agents (BTAs), was used during 4 Brucella events, which accounted for 84% of exposures. In 3 of these incidents, initial staining of liquid media showed Gram-positive rods or cocci, including some cocci in chains, suggesting streptococci. Over 200 occupational exposures occurred when the unknown isolates were manipulated and/or tested on open benches, including by procedures that could generate infectious aerosols. During 3 Brucella events, the CLs examined and/or manipulated isolates in a biological safety cabinet (BSC); in each CL, the CL had previously isolated Brucella. Centers for Disease Control and Prevention recommendations to prevent laboratory-acquired brucellosis (LAB) were followed; no seroconversions or LAB cases occurred. Laboratory assessments were conducted after the Brucella events to identify facility-specific risks and mitigations. With increasing MALDI-TOF MS use, CLs are well-advised to adhere strictly to safe work practices, such as handling and manipulating all slow-growing organisms in BSCs and not using MALDI-TOF MS for identification until BTAs have been ruled out

    Millimeter Dust Emission and Planetary Dynamics in the HD 106906 System

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    Debris disks are dusty, optically thin structures around main sequence stars. HD 106906AB is a short-period stellar binary, host to a wide separation planet, HD 106906b, and a debris disk. Only a few known systems include a debris disk and a directly imaged planet, and HD 106906 is the only one in which the planet is exterior to the disk. The debris disk is edge-on and highly asymmetric in scattered light. Here we resolve the disk structure at a resolution of 0.38" (39 au) with the Atacama Large Millimeter/submillimeter Array (ALMA) at a wavelength of 1.3 mm. We model the disk with both a narrow and broad ring of material, and find that a radially broad, axisymmetric disk between radii of ∼\sim50−-100 au is able to capture the structure of the observations without evidence of any asymmetry or eccentricity, other than a tentative stellocentric offset. We place stringent upper limits on both the gas and dust content of a putative circumplanetary disk. We interpret the ALMA data in concert with scattered light observations of the inner ring and astrometric constraints on the planet's orbit, and find that the observations are consistent with a large-separation, low-eccentricity orbit for the planet. A dynamical analysis indicates that the central binary can efficiently stabilize planetesimal orbits interior to ∼\sim100 au, which relaxes the constraints on eccentricity and semimajor axis somewhat. The observational constraints are consistent with in situ formation via gravitational instability, but cannot rule out a scattering event as the origin for HD 106906b's current orbit

    Hydrolysis optimization and characterization study of preparing fatty acids from Jatropha curcas seed oil

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    <p>Abstract</p> <p>Background</p> <p>Fatty acids (FAs) are important as raw materials for the biotechnology industry. Existing methods of FAs production are based on chemical methods. In this study potassium hydroxide (KOH)-catalyzed reactions were utilized to hydrolysis <it>Jatropha curcas </it>seed oil.</p> <p>Results</p> <p>The parameters effect of ethanolic KOH concentration, reaction temperature, and reaction time to free fatty acid (FFA%) were investigated using D-Optimal Design. Characterization of the product has been studied using Fourier transforms infrared spectroscopy (FTIR), gas chromatography (GC) and high performance liquid chromatography (HPLC). The optimum conditions for maximum FFA% were achieved at 1.75M of ethanolic KOH concentration, 65°C of reaction temperature and 2.0 h of reaction time.</p> <p>Conclusions</p> <p>This study showed that ethanolic KOH concentration was significant variable for <it>J. curcas </it>seed oil hydrolysis. In a 18-point experimental design, FFA% of hydrolyzed <it>J. curcas </it>seed oil can be raised from 1.89% to 102.2%, which proved by FTIR and HPLC.</p

    The severity of pandemic H1N1 influenza in the United States, from April to July 2009: A Bayesian analysis

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    Background: Accurate measures of the severity of pandemic (H1N1) 2009 influenza (pH1N1) are needed to assess the likely impact of an anticipated resurgence in the autumn in the Northern Hemisphere. Severity has been difficult to measure because jurisdictions with large numbers of deaths and other severe outcomes have had too many cases to assess the total number with confidence. Also, detection of severe cases may be more likely, resulting in overestimation of the severity of an average case. We sought to estimate the probabilities that symptomatic infection would lead to hospitalization, ICU admission, and death by combining data from multiple sources. Methods and Findings: We used complementary data from two US cities: Milwaukee attempted to identify cases of medically attended infection whether or not they required hospitalization, while New York City focused on the identification of hospitalizations, intensive care admission or mechanical ventilation (hereafter, ICU), and deaths. New York data were used to estimate numerators for ICU and death, and two sources of data - medically attended cases in Milwaukee or self-reported influenza-like illness (ILI) in New York - were used to estimate ratios of symptomatic cases to hospitalizations. Combining these data with estimates of the fraction detected for each level of severity, we estimated the proportion of symptomatic patients who died (symptomatic case-fatality ratio, sCFR), required ICU (sCIR), and required hospitalization (sCHR), overall and by age category. Evidence, prior information, and associated uncertainty were analyzed in a Bayesian evidence synthesis framework. Using medically attended cases and estimates of the proportion of symptomatic cases medically attended, we estimated an sCFR of 0.048% (95% credible interval [CI] 0.026%-0.096%), sCIR of 0.239% (0.134%-0.458%), and sCHR of 1.44% (0.83%-2.64%). Using self-reported ILI, we obtained estimates approximately 7-96lower. sCFR and sCIR appear to be highest in persons aged 18 y and older, and lowest in children aged 5-17 y. sCHR appears to be lowest in persons aged 5-17; our data were too sparse to allow us to determine the group in which it was the highest. Conclusions: These estimates suggest that an autumn-winter pandemic wave of pH1N1 with comparable severity per case could lead to a number of deaths in the range from considerably below that associated with seasonal influenza to slightly higher, but with the greatest impact in children aged 0-4 and adults 18-64. These estimates of impact depend on assumptions about total incidence of infection and would be larger if incidence of symptomatic infection were higher or shifted toward adults, if viral virulence increased, or if suboptimal treatment resulted from stress on the health care system; numbers would decrease if the total proportion of the population symptomatically infected were lower than assumed.published_or_final_versio

    Transmission of Yellow Fever Vaccine Virus Through Blood Transfusion and Organ Transplantation in the USA in 2021: Report of an Investigation

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    BACKGROUND: In 2021, four patients who had received solid organ transplants in the USA developed encephalitis beginning 2-6 weeks after transplantation from a common organ donor. We describe an investigation into the cause of encephalitis in these patients. METHODS: From Nov 7, 2021, to Feb 24, 2022, we conducted a public health investigation involving 15 agencies and medical centres in the USA. We tested various specimens (blood, cerebrospinal fluid, intraocular fluid, serum, and tissues) from the organ donor and recipients by serology, RT-PCR, immunohistochemistry, metagenomic next-generation sequencing, and host gene expression, and conducted a traceback of blood transfusions received by the organ donor. FINDINGS: We identified one read from yellow fever virus in cerebrospinal fluid from the recipient of a kidney using metagenomic next-generation sequencing. Recent infection with yellow fever virus was confirmed in all four organ recipients by identification of yellow fever virus RNA consistent with the 17D vaccine strain in brain tissue from one recipient and seroconversion after transplantation in three recipients. Two patients recovered and two patients had no neurological recovery and died. 3 days before organ procurement, the organ donor received a blood transfusion from a donor who had received a yellow fever vaccine 6 days before blood donation. INTERPRETATION: This investigation substantiates the use of metagenomic next-generation sequencing for the broad-based detection of rare or unexpected pathogens. Health-care workers providing vaccinations should inform patients of the need to defer blood donation for at least 2 weeks after receiving a yellow fever vaccine. Despite mitigation strategies and safety interventions, a low risk of transfusion-transmitted infections remains. FUNDING: US Centers for Disease Control and Prevention (CDC), the Biomedical Advanced Research and Development Authority, and the CDC Epidemiology and Laboratory Capacity Cooperative Agreement for Infectious Diseases

    Auxin metabolism rates and implications for plant development

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    Studies of auxin metabolism rarely express their results as a metabolic rate, although the data obtained would often permit such a calculation to be made. We analyze data from 31 previously published papers to quantify the rates of auxin biosynthesis, conjugation, conjugate hydrolysis, and catabolism in seed plants. Most metabolic pathways have rates in the range 10 nM/h to 1 μM/h, with the exception of auxin conjugation, which has rates as high as ~100 μM/h. The highest rates of auxin conjugation suggests that auxin metabolic sinks may be very small, perhaps as small as a single cell. By contrast, the relatively low rate of auxin biosynthesis requires plants to conserve and recycle auxin during long-distance transport. The consequences for plant development are discussed

    A Spatio-temporal Methodology for Real-time Biosurveillance

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    The article of record as published may be found at https://doi.org/10.1080/08982110802334096In this paper we introduce a new spatio-temporal methodology for biosurveillance entitled the Repeated Two-sample Rank (RTR) procedure. It is designed to sequentially incorporate information from individual observations and thus can operate on data in real-time as it arrives into an automated biosurveillance system. In addition, upon a signal of a possible outbreak, the methodology suggests a way to graphically indicate the likely outbreak location, and the output can subsequently be used to track the spread of an outbreak. Thus, the methodology can be used for both early event detection and situational awareness in automated biosurveillance systems
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