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"Levin, J"
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Agricultural harvesting emissions of ice-nucleating particles
Agricultural activities can modify natural ecosystems and change the nature of the aerosols emitted from those landscapes. The harvesting of crops can loft plant fragments and soil dust into the atmosphere that can travel long distances and interact with clouds far from their sources. In this way harvesting may contribute substantially to ice-nucleating particle (INP) concentrations, especially in regions where agriculture makes up a large percentage of land use. However, a full characterization of particles emitted during harvesting has not been reported. This study characterizes immersion mode INPs emitted during harvesting of several crops in the High Plains region of the United States. The Colorado State University Continuous Flow Diffusion Chamber (CFDC) and the Ice Spectrometer (IS) were utilized to measure INP concentrations during active harvesting of four crops in Kansas and Wyoming. Large spikes of INPs were observed during harvesting, with concentrations over 200 L−1 at −30 °C measured during a wheat harvest. To differentiate between mineral and organic components, a novel heating tube method was employed in real time upstream of the CFDC to deactivate organic INPs in situ. The results indicate that harvesting produces a complex mixture of organic, soil dust, and mineral components that varies for different crops. Electron microscopy analysis showed that while mineral components made up a large proportion of INPs, organic components comprised over 40 % of measured INPs for certain crops at warm temperatures. Heating and enzyme post-treatment of aerosol samples collected for IS processing indicated that bacteria and heat-labile and heat-stable organics contributed to wheat harvest-produced INPs. These results indicate that plant material and organic particles are a significant component of harvest INPs and their impacts on ice formation in clouds and precipitation on a regional scale should be explored.
Journal Article
Efficacy of an Adjuvanted Herpes Zoster Subunit Vaccine in Older Adults
In this randomized, controlled trial involving more than 15,000 participants 50 years of age or older, a varicella–zoster virus subunit vaccine with AS01B adjuvant was found to have an efficacy of more than 96% in preventing herpes zoster.
Herpes zoster, or shingles, results from the reactivation of latent varicella–zoster virus (VZV) in the dorsal-root or cranial-nerve ganglia, usually decades after primary infection.
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Herpes zoster is characterized by a vesicular rash with a unilateral and dermatomal distribution and is almost always accompanied by pain. More than 90% of adults have been infected with VZV and are at risk for herpes zoster.
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Although herpes zoster is most frequent in adults who are 50 years of age or older owing to immunosenescence, it can occur at any age, especially when cell-mediated immunity is decreased as a result of disease . . .
Journal Article
A biogenic secondary organic aerosol source of cirrus ice nucleating particles
Atmospheric ice nucleating particles (INPs) influence global climate by altering cloud formation, lifetime, and precipitation efficiency. The role of secondary organic aerosol (SOA) material as a source of INPs in the ambient atmosphere has not been well defined. Here, we demonstrate the potential for biogenic SOA to activate as depositional INPs in the upper troposphere by combining field measurements with laboratory experiments. Ambient INPs were measured in a remote mountaintop location at –46 °C and an ice supersaturation of 30% with concentrations ranging from 0.1 to 70 L
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. Concentrations of depositional INPs were positively correlated with the mass fractions and loadings of isoprene-derived secondary organic aerosols. Compositional analysis of ice residuals showed that ambient particles with isoprene-derived SOA material can act as depositional ice nuclei. Laboratory experiments further demonstrated the ability of isoprene-derived SOA to nucleate ice under a range of atmospheric conditions. We further show that ambient concentrations of isoprene-derived SOA can be competitive with other INP sources. This demonstrates that isoprene and potentially other biogenically-derived SOA materials could influence cirrus formation and properties.
Ice nucleating particles impact the global climate by altering cloud formation and properties, but the sources of these emissions are not completely characterized. Here, the authors show that secondary organic aerosols formed from the oxidation of organic gases in the atmosphere can be a source of ice nucleating particles.
Journal Article
2013 IDSA Clinical Practice Guideline for Vaccination of the Immunocompromised Host
An international panel of experts prepared an evidenced-based guideline for vaccination of immunocompromised adults and children. These guidelines are intended for use by primary care and subspecialty providers who care for immunocompromised patients. Evidence was often limited. Areas that warrant future investigation are highlighted.
Journal Article
Efficacy, Safety, and Tolerability of Herpes Zoster Vaccine in Persons Aged 50—59 Years
Background. Herpes zoster (HZ) adversely affects individuals aged 50—59, but vaccine efficacy has not been assessed in this population. This study was designed to determine the efficacy, safety, and tolerability of zoster vaccine for preventing HZ in persons aged 50—59 years. Methods. This was a randomized, double-blind, placebo-controlled study of 22 439 subjects aged 50—59 years conducted in North America and Europe. Subjects were given 1 dose of licensed zoster vaccine (ZV) (Zostavax; Merck) and followed for occurrence of HZ for ≥1 year (mean, 1.3 years) postvaccination until accrual of ≥96 confirmed HZ cases (as determined by testing lesions swabs for varicella zoster virus DNA by polymerase chain reaction). Subjects were followed for all adverse events (AEs) from day 1 to day 42 postvaccination and for serious AEs (SAEs) through day 182 postvaccination. Results. The ZV reduced the incidence of HZ (30 cases in vaccine group, 1.99/1000 person-years vs 99 cases in placebo group, 6.57/1000 person-years). Vaccine efficacy for preventing HZ was 69.8% (95% confidence interval, 54.1—80.6). AEs were reported by 72.8% of subjects in the ZV group and 41.5% in the placebo group, with the difference primarily due to higher rates of injection-site AEs and headache. The proportion of subjects reporting SAEs occurring within 42 days postvaccination (ZV, 0.6%; placebo, 0.5%) and 182 days postvaccination (ZV, 2.1%; placebo, 1.9%) was similar between groups. Conclusions. In subjects aged 50—59 years, the ZV significantly reduced the incidence of HZ and was well tolerated. Clinical Trials Registration. NCT00534248.
Journal Article
Efficacy of the Herpes Zoster Subunit Vaccine in Adults 70 Years of Age or Older
In this trial of a recombinant VZV glycoprotein E subunit vaccine with the adjuvant AS01
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, the risk of herpes zoster and postherpetic neuralgia is shown to be significantly lower in association with the vaccine than with placebo among persons 70 years of age or older.
Herpes zoster, or shingles, results from the reactivation of latent varicella–zoster virus (VZV) and typically manifests as a vesicular, painful dermatomal rash.
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The most common complication of herpes zoster, postherpetic neuralgia, manifests as chronic neuropathic pain that can greatly limit daily activities.
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The overall incidence of herpes zoster is 2.0 to 4.6 cases per 1000 person-years but increases with age to 10.0 to 12.8 per 1000 person-years among persons 80 years of age or older.
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Similarly, the incidence of postherpetic neuralgia also increases with age.
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Antiviral therapy can reduce the duration of herpes zoster rash . . .
Journal Article
Persistence of the Efficacy of Zoster Vaccine in the Shingles Prevention Study and the Short-Term Persistence Substudy
Background. The Shingles Prevention Study (SPS; Department of Veterans Affairs Cooperative Study 403) demonstrated that zoster vaccine was efficacious through 4 years after vaccination. The Short-Term Persistence Substudy (STPS) was initiated after the SPS to further assess the persistence of vaccine efficacy. Methods. The STPS re-enrolled 7320 vaccine and 6950 placebo recipients from the 38 546-subject SPS population. Methods of surveillance, case determination, and follow-up were analogous to those in the SPS. Vaccine efficacy for herpes zoster (HZ) burden of illness, incidence of postherpetic neuralgia (PHN), and incidence of HZ were assessed for the STPS population, for the combined SPS and STPS populations, and for each year through year 7 after vaccination. Results. In the STPS as compared to the SPS, vaccine efficacy for HZ burden of illness decreased from 61.1% to 50.1%, vaccine efficacy for the incidence of PHN decreased from 66.5% to 60.1%, and vaccine efficacy for the incidence of HZ decreased from 51.3% to 39.6%, although the differences were not statistically significant. Analysis of vaccine efficacy in each year after vaccination for all 3 outcomes showed a decrease in vaccine efficacy after year 1, with a further decline thereafter. Vaccine efficacy was statistically significant for the incidence of HZ and the HZ burden of illness through year 5. Conclusions. Vaccine efficacy for each study outcome was lower in the STPS than in the SPS. There is evidence of the persistence of vaccine efficacy through year 5 after vaccination but, vaccine efficacy is uncertain beyond that point.
Journal Article