Using Satellite Measurements to Investigate Regional-scale Chemistry: The Case for Geostationary Observations

One of the recommendations of the Decadal Survey that was recently released by the National Academy of Science was that of a geostationary platform from which to obtain trace gas measurements. The use of such a platform is particularly advantageous when applied to understanding the formation of regional air pollution. This study demonstrates the challenges of trying to utilize information from instruments on satellites in low-earth orbit (LEO). We also demonstrate the advantage gained through a simulation that would provide hourly observations. In this case study, we take advantage of the high resolution Level-2 orbital data available from the Ozone Monitoring Instrument (OMI), in conjunction with assimilated stratospheric column ozone fields, to evaluate if meaningful tropospheric ozone information can be obtained on a regional scale. We focus on a period on late June 2005 when a widespread pollution episode enveloped the Houston metropolitan area as well as a large region in southeast Texas

Street Outreach Workers: Best Practices and Lessons Learned

Street outreach workers are an important part of the Senator Charles E. Shannon Jr. Community Safety Initiative (CSI) comprehensive gang and youth violence reduction strategy in Massachusetts1. Street outreach involves the use of individuals to “work the streets,” making contact with youth in neighborhoods with high levels of gang activity. These individuals are generally not employed by the criminal justice system agencies but rather are based in community service organizations or other non- governmental agencies. Street outreach workers provide an important bridge between the community, gang-involved youth, and the agencies (whether social service or law enforcement) that respond to the problems of delinquency and gangs. This guide offers information, guidance, and lessons learned from street outreach programs nationally and within the Massachusetts Shannon CSI communities to help guide existing street outreach programs and support communities considering developing new street outreach programs

Chytrid fungus infection in alpine tree frogs is associated with individual heterozygosity and population isolation but not population-genetic diversity

Chytridiomycosis, a disease caused by the emerging fungus Batrachochytrium dendrobatidis (Bd), has been implicated in the decline of over 500 amphibian species. Population declines could have important genetic consequences, including reduced genetic diversity. We contrasted genetic diversity among both long-Bd-exposed and unexposed populations of the south-east Australian alpine tree frog (Litoria verreauxii alpina) across its range. At the population level, we found no significant differences in genetic diversity between Bd-exposed and unexposed populations. Encouragingly, even Bd-infected remnant populations that are now highly isolated maintain genetic diversity comparable to populations in which Bd is absent. Spatial genetic structure among populations followed an isolation-by-distance pattern, suggesting restricted movement among remnant populations. At the individual level, greater heterozygosity was associated with reduced probability of infection. Loss of genetic diversity in remnant populations that survived chytridiomycosis epidemics does not appear to be a threat to L. v. alpina. We suggest several factors underpinning maintenance of genetic diversity: (1) remnant populations have remained large enough to avoid losses of genetic diversity; (2) many individuals in the population are able to breed once before succumbing to disease; and (3) juveniles in the terrestrial environment have low exposure to Bd, providing an annual ‘reservoir’ of genetic diversity. The association between individual heterozygosity and infection status suggests that, while other work has shown all breeding adults are typically killed by Bd, males with greater heterozygosity may survive longer and obtain fitness benefits through extended breeding opportunities. Our results highlight the critical role of life history in mitigating the impacts of Bd infection for some amphibian species, but we infer that increased isolation as a result of disease-induced population extirpations will enhance population differentiation and thus biogeographic structure

Altering the Size Distribution of Influenza Virion Populations [Poster]

Harry Smith Vacation Studentship Laboratory-adapted influenza viruses produce predominantly spherical virions. In contrast, clinical and veterinary isolates produce a mixture of virions of different sizes, from 0.1 µm spheres to filaments which can reach tens of microns in length. Filamentous influenza virions were discovered in 1946, but the bulk of influenza research has analysed only spherical forms of the virus and the role of filaments in influenza infections is unclear. Functional studies of filaments require the development of methods to manipulate the ratio of spherical to filamentous virions, and we reasoned that this could be achieved by filtration. To test this, we infected MDCK cells with the filamentous Udorn strain of influenza A virus. We collected virus-containing growth media and passed this through filters with 5 µm, 0.45 µm and 0.2 µm pores. Filtrates and unfiltered virus were compared, using Western blotting to measure their protein composition, plaque assays to measure their infectivity and negative stain transmission electron microscopy to measure individual particle sizes. We found that filtration through a filter with 5 µm pores had little effect on composition, infectivity and the ratio of spherical to filamentous particles. In contrast, sub-micron filters, particularly those with 0.2 µm pores, caused a general depletion of virions but increased the sphere to filament ratio. We therefore concluded that sub-micron pore sizes can be used to preferentially remove filaments from populations of pleomorphic influenza virions, providing a useful tool for subtractive studies of the contribution filaments make to influenza virus infections

Single-particle Measurements Reveal Damage to Filamentous Influenza Virions During Laboratory Handling [Poster]

Most laboratory strains of influenza virus produce near-spherical virions, but clinical isolates also produce extended filaments whose biophysical properties are understudied. Most functional studies of filamentous influenza viruses do not include data on the concentration or lengths of the virions, making it hard to interpret their sometimes contradictory results. Furthermore, anecdotal reports suggest that filaments are damaged during routine laboratory handling. Therefore, to understand filament function we require a tool to assess the number and dimensions of filaments in a sample and an assessment of how filaments respond to standard handling procedures. We initially sought to analyse filament populations using negative stain particle counting, but found that this was low-throughput and could not detect particles longer than 10 µm. Instead, we used confocal microscopy with semi-automated image analysis. This allowed a high-throughput, quantitative analysis of length distributions in filament populations. Using this, we assessed the effects of pipetting, vortexing, sonicating, clarification and freezing on filaments. Most procedures did not appreciably alter filament dimensions. Pipetting and vortexing both slightly reduced filament numbers, but their effects were only appreciable after extended treatment. In contrast, freezing substantially reduced the number and median length of filaments, as well as creating ‘kinks’ in filaments which suggest damage to the capsid. We conclude that confocal microscopy can provide the basic measurements needed to interpret functional studies of filamentous strains. Using this approach, we found that freezing filaments causes previously unappreciated damage, which should be considered when planning further research

A Mixed-Methods Assessment of Human Well-Being Related to the Presence of Companion Animals During the COVID-19 Pandemic

COVID-19 and the measures used to curb the pandemic (e.g., lockdowns, isolation) have significantly impacted mental health and well-being. This study sought to investigate the role of companion animals in alleviating stress and improving mental health during the pandemic. In this study, 250 Australian adults completed measures of well-being and life satisfaction, animal dependency, perceived emotional support from animals, and animals’ effect on mood. Employment and living with others were the strongest predictors of positive life satisfaction and well-being, while greater dependency on companion animals for emotional support and companion animals’ negative effects on mood were associated with reduced life satisfaction and well-being. Qualitative data indicated equivocal results with animals a source of both support and stress, pointing to the complex nature of human–animal relationships, particularly during times of considerable stress. These outcomes have significant implications for welfare, as animals perceived to be annoying or disruptive may be at higher risk of abuse, neglect, and behavioral surrendering

Comparison of Tropospheric Ozone Columns Calculated from MLS, OMI, and Ozonesonde Data

This poster shows a comparison of three derived tropospheric ozone residual (TOR) products with integrated tropospheric ozone columns from ozonesonde profile: (1) the method of Ziemke et al. (2006), (2) a modified version of Fishman et al. (2003), and (3) a trajectory mapping approach. In each case, MLS ozone profiles are integrated to the tropopause and subtracted from OMI (TOMS retrieval) total column ozone. The effectiveness of each of these techniques is examined as a function of latitude, time, and geographic region. In general, we find good agreement between the derived products and the ozonesondes, with the Fishman et al. TOR (labeled “Amy”) generally high and the Schoeberl trajectory mapping (labeled “Mark”) product generally low as compared to the integrated ozonesonde profiles (labeled “Sonde”) as computed using the WMO tropopause definition. Differences in TOR results are due, at least in part, to non-uniform tropopause height definitions between the three approaches

Region-specific and activity-dependent regulation of SVZ neurogenesis and recovery after stroke.

Stroke is the leading cause of adult disability. Neurogenesis after stroke is associated with repair; however, the mechanisms regulating poststroke neurogenesis and its functional effect remain unclear. Here, we investigate multiple mechanistic routes of induced neurogenesis in the poststroke brain, using both a forelimb overuse manipulation that models a clinical neurorehabilitation paradigm, as well as local manipulation of cellular activity in the peri-infarct cortex. Increased activity in the forelimb peri-infarct cortex via either modulation drives increased subventricular zone (SVZ) progenitor proliferation, migration, and neuronal maturation in peri-infarct cortex. This effect is sensitive to competition from neighboring brain regions. By using orthogonal tract tracing and rabies virus approaches in transgenic SVZ-lineage-tracing mice, SVZ-derived neurons synaptically integrate into the peri-infarct cortex; these effects are enhanced with forelimb overuse. Synaptic transmission from these newborn SVZ-derived neurons is critical for spontaneous recovery after stroke, as tetanus neurotoxin silencing specifically of the SVZ-derived neurons disrupts the formation of these synaptic connections and hinders functional recovery after stroke. SVZ-derived neurogenesis after stroke is activity-dependent, region-specific, and sensitive to modulation, and the synaptic connections formed by these newborn cells are functionally critical for poststroke recovery

Understanding the Organization, Operation, and Victimization Process of Labor Trafficking in the United States

This study examines the organization, operation, and victimization process of labor trafficking across multiple industries in the United States. It examines labor trafficking victim abuse and exploitation along a continuum, from victims' recruitment for work in the United States; through their migration experiences (if any), employment victimization experiences, and efforts to seek help; to their ultimate escape and receipt of services. Data for this study came from a sample of 122 closed labor trafficking victim service records from service providers in four US cities. In addition, interviews were conducted with labor trafficking survivors, local and federal law enforcement officials, legal advocates, and service providers in each site to better understand the labor trafficking victimization experience, the networks involved in labor trafficking and the escape and removal process, and the barriers to investigation and prosecution of labor trafficking cases