Interpretation of cosmic ray composition: The pathlength distribution

For abstract see A81-43868

Laboratory measurements and model sensitivity studies of dust deposition ice nucleation

We investigated the ice nucleating properties of mineral dust particles to understand the sensitivity of simulated cloud properties to two different representations of contact angle in the Classical Nucleation Theory (CNT). These contact angle representations are based on two sets of laboratory deposition ice nucleation measurements: Arizona Test Dust (ATD) particles of 100, 300 and 500 nm sizes were tested at three different temperatures (−25, −30 and −35 °C), and 400 nm ATD and kaolinite dust species were tested at two different temperatures (−30 and −35 °C). These measurements were used to derive the onset relative humidity with respect to ice (RH<sub>ice</sub>) required to activate 1% of dust particles as ice nuclei, from which the onset single contact angles were then calculated based on CNT. For the probability density function (PDF) representation, parameters of the log-normal contact angle distribution were determined by fitting CNT-predicted activated fraction to the measurements at different RH<sub>ice</sub>. Results show that onset single contact angles vary from ~18 to 24 degrees, while the PDF parameters are sensitive to the measurement conditions (i.e. temperature and dust size). Cloud modeling simulations were performed to understand the sensitivity of cloud properties (i.e. ice number concentration, ice water content, and cloud initiation times) to the representation of contact angle and PDF distribution parameters. The model simulations show that cloud properties are sensitive to onset single contact angles and PDF distribution parameters. The comparison of our experimental results with other studies shows that under similar measurement conditions the onset single contact angles are consistent within ±2.0 degrees, while our derived PDF parameters have larger discrepancies

A Case Study of Microphysical Structures and Hydrometeor Phase in Convection Using Radar Doppler Spectra at Darwin, Australia

To understand the microphysical processes that impact diabatic heating and cloud lifetimes in convection, we need to characterize the spatial distribution of supercooled liquid water. To address this observational challenge, vertically pointing active sensors at the Darwin Atmospheric Radiation Measurement (ARM) site are used to classify cloud phase within a deep convective cloud in a shallow to deep convection transitional case. The cloud cannot be fully observed by a lidar due to signal attenuation. Thus we develop an objective method for identifying hydrometeor classes, including mixed-phase conditions, using k-means clustering on parameters that describe the shape of the Doppler spectra from vertically pointing Ka band cloud radar. This approach shows that multiple, overlapping mixed-phase layers exist within the cloud, rather than a single region of supercooled liquid, indicating complexity to how ice growth and diabatic heating occurs in the vertical structure of the cloud

Influenza vaccination coverage among an urban pediatric asthma population: Implications for population health

Introduction Asthma is the most common chronic disease in children. Children with asthma are at high risk for complications from influenza; however annual influenza vaccination rates for this population are suboptimal. The overall aim of this study was to describe the characteristics of a high-risk population of children with asthma presenting to an urban pediatric emergency department according to influenza vaccination status. Methods The study was a retrospective chart review of 4355 patients aged 2 to 18 years evaluated in a Michigan pediatric emergency department (PED) between November 1, 2017 and April 30, 2018 with an ICD-10-CM code for asthma (J45.x). Eligible patient PED records were matched with influenza vaccination records for the 2017–2018 influenza season from the Michigan Care Improvement Registry. Geospatial analysis was employed to examine the distribution of influenza vaccination status. Results 1049 patients (30.9%) with asthma seen in the PED had received an influenza vaccine. Influenza vaccination coverage varied by Census Tract, ranging from 10% to \u3e 99%. Most vaccines were administered in a primary care setting (84.3%) and were covered by public insurance (76.8%). The influenza vaccination rate was lowest for children aged 5–11 years (30.0%) and vaccination status was associated with race (p\u3c0.001) and insurance type (p\u3c0.001). Conclusions Identification of neighborhood Census Tract and demographic groups with suboptimal influenza vaccination could guide development of targeted public health interventions to improve vaccination rates in high-risk patients. Given the morbidity and mortality associated with pediatric asthma, a data-driven approach may improve outcomes and reduce healthcare-associated costs for this pediatric population

Evidence of Extensive DNA Transfer between Bacteroidales Species within the Human Gut

ABSTRACT The genome sequences of intestinal Bacteroidales strains reveal evidence of extensive horizontal gene transfer. In vitro studies of Bacteroides and other bacteria have addressed mechanisms of conjugative transfer and some phenotypic outcomes of these DNA acquisitions in the recipient, such as the acquisition of antibiotic resistance. However, few studies have addressed the horizontal transfer of genetic elements between bacterial species coresident in natural microbial communities, especially microbial ecosystems of humans. Here, we examine the genomes of Bacteroidales species from two human adults to identify genetic elements that were likely transferred among these Bacteroidales while they were coresident in the intestine. Using seven coresident Bacteroidales species from one individual and eight from another, we identified five large chromosomal regions, each present in a minimum of three of the coresident strains at near 100% DNA identity. These five regions are not found in any other sequenced Bacteroidetes genome at this level of identity and are likely all integrative conjugative elements (ICEs). Such highly similar and unique regions occur in only 0.4% of phylogenetically representative mock communities, providing strong evidence that these five regions were transferred between coresident strains in these subjects. In addition to the requisite proteins necessary for transfer, these elements encode proteins predicted to increase fitness, including orphan DNA methylases that may alter gene expression, fimbriae synthesis proteins that may facilitate attachment and the utilization of new substrates, putative secreted antimicrobial molecules, and a predicted type VI secretion system (T6SS), which may confer a competitive ecological advantage to these strains in their complex microbial ecosystem

Regulation of surface architecture by symbiotic bacteria mediates host colonization

Microbes occupy countless ecological niches in nature. Sometimes these environments may be on or within another organism, as is the case in both microbial infections and symbiosis of mammals. Unlike pathogens that establish opportunistic infections, hundreds of human commensal bacterial species establish a lifelong cohabitation with their hosts. Although many virulence factors of infectious bacteria have been described, the molecular mechanisms used during beneficial host–symbiont colonization remain almost entirely unknown. The novel identification of multiple surface polysaccharides in the important human symbiont Bacteroides fragilis raised the critical question of how these molecules contribute to commensalism. To understand the function of the bacterial capsule during symbiotic colonization of mammals, we generated B. fragilis strains deleted in the global regulator of polysaccharide expression and isolated mutants with defects in capsule expression. Surprisingly, attempts to completely eliminate capsule production are not tolerated by the microorganism, which displays growth deficits and subsequent reversion to express capsular polysaccharides. We identify an alternative pathway by which B. fragilis is able to reestablish capsule production and modulate expression of surface structures. Most importantly, mutants expressing single, defined surface polysaccharides are defective for intestinal colonization compared with bacteria expressing a complete polysaccharide repertoire. Restoring the expression of multiple capsular polysaccharides rescues the inability of mutants to compete for commensalism. These findings suggest a model whereby display of multiple capsular polysaccharides provides essential functions for bacterial colonization during host–symbiont mutualism

Essentially English : Sherlock Holmes at the BBC

Sir Arthur Conan Doyle’s Sherlock Holmes stories, currently enjoying renewed popularity on television via the BBC’s Sherlock (2010- ), have been adapted for the screen countless times around the world. Arguably best remembered are Granada’s long-running strand with Jeremy Brett (1984-94), and the Universal film series of the 1940s, featuring Basil Rathbone and Nigel Bruce. Less frequently cited, however, are the two series produced by the BBC between 1965 and 1968, in which first Douglas Wilmer and later Peter Cushing took on the mantle of the Baker Street detective. Typically for the time – but against the wishes of the Conan Doyle estate - these programmes adopted a multi-camera studio model; a mode of production which made them less attractive to US networks than the single camera 35mm film output of commercial rivals such as ITC. Drawing upon material from the BBC’s Written Archives Centre, this article investigates the motivations underpinning the Corporation’s refusal to accommodate the estate’s exhortations to seek American co-production and utilise single camera filming, not least of which was the BBC’s stated desire to maintain the ‘essentially English’ quality of Sherlock Holmes. This decision would have significant repercussions for the series’ overseas saleability, and – despite impressive viewing figures and positive audience reaction at home in the UK – helped contribute to its ‘forgotten’ status with regard to the television canon

ARM Research in the Equatorial Western Pacific: A Decade and Counting

The tropical western Pacific (TWP) is an important climatic region. Strong solar heating, warm sea surface temperatures, and the annual progression of the intertropical convergence zone (ITCZ) across this region generate abundant convective systems, which through their effects on the heat and water budgets have a profound impact on global climate and precipitation. In order to accurately evaluate tropical cloud systems in models, measurements of tropical clouds, the environment in which they reside, and their impact on the radiation and water budgets are needed. Because of the remote location, ground-based datasets of cloud, atmosphere, and radiation properties from the TWP region have come primarily from short-term field experiments. While providing extremely useful information on physical processes, these short-term datasets are limited in statistical and climatological information. To provide longterm measurements of the surface radiation budget in the tropics and the atmospheric properties that affect it, the Atmospheric Radiation Measurement program established a measurement site on Manus Island, Papua New Guinea, in 1996 and on the island republic of Nauru in late 1998. These sites provide unique datasets now available for more than 10 years on Manus and Nauru. This article presents examples of the scientific use of these datasets including characterization of cloud properties, analysis of cloud radiative forcing, model studies of tropical clouds and processes, and validation of satellite algorithms. New instrumentation recently installed at the Manus site will provide expanded opportunities for tropical atmospheric science

Adolescent Religiosity and Selective Exposure to Television

Relying on the Adolescent Media Practice Model and selective exposure theory, this study investigated whether religious adolescents watch less mature television entertainment programs than their less religious peers. Program maturity was measured using V-chip ratings, with higher maturity scores indicating content that included more sexuality, violence, and/or adult and sexual language. The responses from 1,335 16- to 18-year-olds who completed Wave 2 of the National Study of Youth and Religion (NSYR) survey were analyzed. Findings indicate that religiosity contributes to explaining the variance in television maturity means, with more religious adolescents indicating a preference for less mature television entertainment. Gender, race, income, and parents’ monitoring of teens’ media were also found to influence television maturity. Teens’ attitudes toward premarital sex appeared to mediate the effect of religiosity on their television entertainment choices