Comprehensive Simultaneous Shipboard and Airborne Characterization of Exhaust from a Modern Container Ship at Sea

We report the first joint shipboard and airborne study focused on the chemical composition and water-uptake behavior of particulate ship emissions. The study focuses on emissions from the main propulsion engine of a Post-Panamax class container ship cruising off the central coast of California and burning heavy fuel oil. Shipboard sampling included micro-orifice uniform deposit impactors (MOUDI) with subsequent off-line analysis, whereas airborne measurements involved a number of real-time analyzers to characterize the plume aerosol, aged from a few seconds to over an hour. The mass ratio of particulate organic carbon to sulfate at the base of the ship stack was 0.23 ± 0.03, and increased to 0.30 ± 0.01 in the airborne exhaust plume, with the additional organic mass in the airborne plume being concentrated largely in particles below 100 nm in diameter. The organic to sulfate mass ratio in the exhaust aerosol remained constant during the first hour of plume dilution into the marine boundary layer. The mass spectrum of the organic fraction of the exhaust aerosol strongly resembles that of emissions from other diesel sources and appears to be predominantly hydrocarbon-like organic (HOA) material. Background aerosol which, based on air mass back trajectories, probably consisted of aged ship emissions and marine aerosol, contained a lower organic mass fraction than the fresh plume and had a much more oxidized organic component. A volume-weighted mixing rule is able to accurately predict hygroscopic growth factors in the background aerosol but measured and calculated growth factors do not agree for aerosols in the ship exhaust plume. Calculated CCN concentrations, at supersaturations ranging from 0.1 to 0.33%, agree well with measurements in the ship-exhaust plume. Using size-resolved chemical composition instead of bulk submicrometer composition has little effect on the predicted CCN concentrations because the cutoff diameter for CCN activation is larger than the diameter where the mass fraction of organic aerosol begins to increase significantly. The particle number emission factor estimated from this study is 1.3 × 10^(16) (kg fuel)^(−1), with less than 1/10 of the particles having diameters above 100 nm; 24% of particles (>10 nm in diameter) activate into cloud droplets at 0.3% supersaturation

Multiple photosynthetic transitions, polyploidy, and lateral gene transfer in the grass subtribe Neurachninae

The Neurachninae is the only grass lineage known to contain C3, C4, and C3–C4 intermediate species, and as such has been suggested as a model system for studies of photosynthetic pathway evolution in the Poaceae; however, a lack of a robust phylogenetic framework has hindered this possibility. In this study, plastid and nuclear markers were used to reconstruct evolutionary relationships among Neurachninae species. In addition, photosynthetic types were determined with carbon isotope ratios, and genome sizes with flow cytometry. A high frequency of autopolyploidy was found in the Neurachninae, including in Neurachne munroi F.Muell. and Paraneurachne muelleri S.T.Blake, which independently evolved C4 photosynthesis. Phylogenetic analyses also showed that following their separate C4 origins, these two taxa exchanged a gene encoding the C4 form of phosphoenolpyruvate carboxylase. The C3–C4 intermediate Neurachne minor S.T.Blake is phylogenetically distinct from the two C4 lineages, indicating that intermediacy in this species evolved separately from transitional stages preceding C4 origins. The Neurachninae shows a substantial capacity to evolve new photosynthetic pathways repeatedly. Enablers of these transitions might include anatomical pre-conditions in the C3 ancestor, and frequent autopolyploidization. Transfer of key C4 genetic elements between independently evolved C4 taxa may have also facilitated a rapid adaptation of photosynthesis in these grasses that had to survive in the harsh climate appearing during the late Pliocene in Australia

Relativistic separable dual-space Gaussian Pseudopotentials from H to Rn

We generalize the concept of separable dual-space Gaussian pseudopotentials to the relativistic case. This allows us to construct this type of pseudopotential for the whole periodic table and we present a complete table of pseudopotential parameters for all the elements from H to Rn. The relativistic version of this pseudopotential retains all the advantages of its nonrelativistic version. It is separable by construction, it is optimal for integration on a real space grid, it is highly accurate and due to its analytic form it can be specified by a very small number of parameters. The accuracy of the pseudopotential is illustrated by an extensive series of molecular calculations

On the link between ocean biota emissions, aerosol, and maritime clouds: Airborne, ground, and satellite measurements off the coast of California

Surface, airborne, and satellite measurements over the eastern Pacific Ocean off the coast of California during the period between 2005 and 2007 are used to explore the relationship between ocean chlorophyll a, aerosol, and marine clouds. Periods of enhanced chlorophyll a and wind speed are coincident with increases in particulate diethylamine and methanesulfonate concentrations. The measurements indicate that amines are a source of secondary organic aerosol in the marine atmosphere. Subsaturated aerosol hygroscopic growth measurements indicate that the organic component during periods of high chlorophyll a and wind speed exhibit considerable water uptake ability. Increased average cloud condensation nucleus (CCN) activity during periods of increased chlorophyll a levels likely results from both size distribution and aerosol composition changes. The available data over the period of measurements indicate that the cloud microphysical response, as represented by either cloud droplet number concentration or cloud droplet effective radius, is likely influenced by a combination of atmospheric dynamics and aerosol perturbations during periods of high chlorophyll a concentrations

Microbiological quality assessment of suya sold in Yenagoa, metropolis, Nigeria

This study assessed the microbial quality of suya sold in Yenagoa metropolis, Nigeria. Triplicate sample of suya were purchased from six communities in Yenagoa metropolis. Standard microbiological procedures were used for determining the microbial diversity and density. Results for the total heterotrophic bacteria, total coliform and total fungi ranged from 3.93 – 4.98, 2.94– 3.33 and 2.84 – 3.48 Log cfu/g, respectively. Analysis of variance showed that there were no significance differences (P>0.05) among the suya sample vended in some location in Yenagoa metropolis, Bayelsa state, Nigeria. Six and four bacterial and mould isolates were identified and among them the highest and least occurrence frequenies were Staphylococcus aureus (28.1%) and Proteus species (9.3%) for bacteria and  Aspergillus niger (39.7%) and Mucor species (11.8%) for mould respectively. Other bacterial isolates include Escherichia coli, Bacillus, Micrococcus and Pseudomonas species and fungi isolates were Aspergillus flavus  and Penicillium species. The implication of microbial diversity and density on potential consumers of suya in Yenagoa metropolis were discussed

A four-dimensional probabilistic atlas of the human brain

The authors describe the development of a four-dimensional atlas and reference system that includes both macroscopic and microscopic information on structure and function of the human brain in persons between the ages of 18 and 90 years. Given the presumed large but previously unquantified degree of structural and functional variance among normal persons in the human population, the basis for this atlas and reference system is probabilistic. Through the efforts of the International Consortium for Brain Mapping (ICBM), 7,000 subjects will be included in the initial phase of database and atlas development. For each subject, detailed demographic, clinical, behavioral, and imaging information is being collected. In addition, 5,800 subjects will contribute DNA for the purpose of determining genotype-phenotype-behavioral correlations. The process of developing the strategies, algorithms, data collection methods, validation approaches, database structures, and distribution of results is described in this report. Examples of applications of the approach are described for the normal brain in both adults and children as well as in patients with schizophrenia. This project should provide new insights into the relationship between microscopic and macroscopic structure and function in the human brain and should have important implications in basic neuroscience, clinical diagnostics, and cerebral disorders

Expressions 2021

https://openspace.dmacc.edu/expressions/1037/thumbnail.jp

The Experience of Parents of Early-Returned Missionaries

This paper shares the results of a mixed methods study designed to understand the lived experiences of parents of early-returned LDS missionaries. Researchers conducted two focus groups of parents (n = 7) and developed and administered a survey (n = 199). The study considered the phenomenon through the theoretical lenses of Kübler-Ross’s model of grief and Boss’s model of ambiguous loss. The results suggested that parents struggle with the early-return process, the lack of communication with mission presidents, a perceived lack of support from some church leaders and ward members, and personal adjustment to their child’s early return. Clinical implications include suggestions for improved parental adjustment and seven assumptions regarding ambiguous loss

Development and validation of the Transgender Adolescent Stress Survey-Dysphoria

ObjectiveTransgender and nonbinary adolescents (TNBA) may experience gender dysphoria arising from incongruities between their body and their gender. Prior dysphoria measures have largely focused on clinical diagnosis with little regard to comparability of forms for people assigned male or female at birth, overall psychometric performance, or applicability to nonbinary populations. This study develops and validates the Transgender Adolescent Stress Survey-Dysphoria (TASS-D), intended to address these gaps.MethodsThe current study recruited a U.S. national sample of TNBA (N = 444, aged 12–17; 65.5% White, 9.5% Black, 9.5% Latine, 15.5% other ethnicity; 34.7% transmasculine, 17.3% transfeminine, 38.3% nonbinary, 9.5% agender). The item pool was developed from life history calendars, a modified Delphi process, and cognitive interviews with TNBA. Scale development included factor analysis, item response theory modeling, measurement invariance testing, and reliability analyses. Associations were examined between the TASS-D and existing measures of gender dysphoria (convergent validity), gender minority stress (divergent validity), and behavioral health outcomes (criterion validity).ResultsTASS-D and its subscales (body distress and gender expression burden) were significantly and strongly associated with gender dysphoria; significantly but weakly associated with gender minority stress; and significantly associated with most indicators of psychological distress including depressive, anxiety, and posttraumatic stress symptoms, suicidal behaviors and nonsuicidal self-injury.ConclusionsThe TASS-D is a reliable and valid measure of gender dysphoria for TNBA, offering notable benefits over existing measures: It is psychometrically sound, inclusive of all gender identities, and does not assume that respondents identify binarily or desire medical transition as a terminal goal