Catalyzed Gasoline Particulate Filters Reduce Secondary Organic Aerosol Production from Gasoline Direct Injection Vehicles

The effects of photochemical aging on exhaust emissions from two light-duty vehicles with gasoline direct injection (GDI) engines equipped with and without catalyzed gasoline particle filters (GPFs) were investigated using a mobile environmental chamber. Both vehicles with and without the GPFs were exercised over the LA92 drive cycle using a chassis dynamometer. Diluted exhaust emissions from the entire LA92 cycle were introduced to the mobile chamber and subsequently photochemically reacted. It was found that the addition of catalyzed GPFs will significantly reduce tailpipe particulate emissions and also provide benefits in gaseous emissions, including nonmethane hydrocarbons (NMHC). Tailpipe emissions composition showed important changes with the use of GPFs by practically eliminating black carbon and increasing the fractional contribution of organic mass. Production of secondary organic aerosol (SOA) was reduced with GPF addition, but was also dependent on engine design which determined the amount of SOA precursors at the tailpipe. Our findings indicate that SOA production from GDI vehicles will be reduced with the application of catalyzed GPFs through the mitigation of reactive hydrocarbon precursors

Oakleaf: an S locus-linked mutation of Primula vulgaris that affects leaf and flower development

•In Primula vulgaris outcrossing is promoted through reciprocal herkogamy with insect-mediated cross-pollination between pin and thrum form flowers. Development of heteromorphic flowers is coordinated by genes at the S locus. To underpin construction of a genetic map facilitating isolation of these S locus genes, we have characterised Oakleaf, a novel S locus-linked mutant phenotype. •We combine phenotypic observation of flower and leaf development, with classical genetic analysis and next-generation sequencing to address the molecular basis of Oakleaf. •Oakleaf is a dominant mutation that affects both leaf and flower development; plants produce distinctive lobed leaves, with occasional ectopic meristems on the veins. This phenotype is reminiscent of overexpression of Class I KNOX-homeodomain transcription factors. We describe the structure and expression of all eight P. vulgaris PvKNOX genes in both wild-type and Oakleaf plants, and present comparative transcriptome analysis of leaves and flowers from Oakleaf and wild-type plants. •Oakleaf provides a new phenotypic marker for genetic analysis of the Primula S locus. We show that none of the Class I PvKNOX genes are strongly upregulated in Oakleaf leaves and flowers, and identify cohorts of 507 upregulated and 314 downregulated genes in the Oakleaf mutant

Popular music, psychogeography, place identity and tourism: The case of Sheffield

Tourism and cultural agencies in some English provincial cities are promoting their popular music ‘heritage’ and, in some cases, contemporary musicians through the packaging of trails, sites, ‘iconic’ venues and festivals. This article focuses on Sheffield, a ‘post-industrial’ northern English city which is drawing on its associations with musicians past and present in seeking to attract tourists. This article is based on interviews with, among others, recording artists, promoters, producers and venue managers, along with reflective observational and documentary data. Theoretical remarks are made on the representations of popular musicians through cultural tourism strategies, programmes and products and also on the ways in which musicians convey a ‘psychogeographical’ sense of place in the ‘soundscape’ of the city

Cloud condensation nuclei (CCN) activity of aliphatic amine secondary aerosol

Aliphatic amines can form secondary aerosol via oxidation with atmospheric radicals (e.g., hydroxyl radical and nitrate radical). The particle can contain both secondary organic aerosol (SOA) and inorganic salts. The ratio of organic to inorganic materials in the particulate phase influences aerosol hygroscopicity and cloud condensation nuclei (CCN) activity. SOA formed from trimethylamine (TMA) and butylamine (BA) reactions with hydroxyl radical (OH) is composed of organic material of low hygroscopicity (single hygroscopicity parameter, κ, ≤ 0.25). Secondary aerosol formed from the tertiary aliphatic amine (TMA) with N_2O_5 (source of nitrate radical, NO_3) contains less volatile compounds than the primary aliphatic amine (BA) aerosol. As relative humidity (RH) increases, inorganic amine salts are formed as a result of acid–base reactions. The CCN activity of the humid TMA–N_2O_5 aerosol obeys Zdanovskii, Stokes, and Robinson (ZSR) ideal mixing rules. The humid BA + N_2O_5 aerosol products were found to be very sensitive to the temperature at which the measurements were made within the streamwise continuous-flow thermal gradient CCN counter; κ ranges from 0.4 to 0.7 dependent on the instrument supersaturation (ss) settings. The variance of the measured aerosol κ values indicates that simple ZSR rules cannot be applied to the CCN results from the primary aliphatic amine system. Overall, aliphatic amine aerosol systems' κ ranges within 0.2 < κ < 0.7. This work indicates that aerosols formed via nighttime reactions with amines are likely to produce hygroscopic and volatile aerosol, whereas photochemical reactions with OH produce secondary organic aerosol of lower CCN activity. The contributions of semivolatile secondary organic and inorganic material from aliphatic amines must be considered for accurate hygroscopicity and CCN predictions from aliphatic amine systems

New particle formation from photooxidation of diiodomethane (CH_2I_2)

Photolysis of CH_2I_2 in the presence of O_3 has been proposed as a mechanism leading to intense new particle formation in coastal areas. We report here a comprehensive laboratory chamber study of this system. Rapid homogeneous nucleation was observed over three orders of magnitude in CH_2I_2 mixing ratio, down to a level of 15 ppt (∼4 × 10^8 molec. cm^(−3)) comparable to the directly measured total gas-phase iodine species concentrations in coastal areas. After the nucleation burst, the observed aerosol dynamics in the chamber was dominated by condensation of additional vapors onto existing particles and particle coagulation. Particles formed under dry conditions are fractal agglomerates with mass fractal dimension, D_f ∼ 1.8–2.5. Higher relative humidity (65%) does not change the nucleation or growth behavior from that under dry conditions, but results in more compact and dense particles (D_f ∼ 2.7). On the basis of the known gas-phase chemistry, OIO is the most likely gas-phase species to produce the observed nucleation and aerosol growth; however, the current understanding of this chemistry is very likely incomplete. Chemical analysis of the aerosol using an Aerodyne Aerosol Mass Spectrometer reveals that the particles are composed mainly of iodine oxides but also contain water and/or iodine oxyacids. The system studied here can produce nucleation events as intense as those observed in coastal areas. On the basis of comparison between the particle composition, hygroscopicity, and nucleation and growth rates observed in coastal nucleation and in the experiments reported here, it is likely that photooxidation of CH_2I_2, probably aided by other organic iodine compounds, is the mechanism leading to the observed new particle formation in the west coast of Ireland

Positioning discourse on homophobia in schools: what have lesbian and gay families got to say?

This paper reports findings from a study in England, which investigated the experiences of lesbian and gay parents in relation to homophobia in primary and secondary schools. The study was part of a larger European Union project investigating the impact of family and school alliances against homophobic and transphobic bullying in schools across six nation states. Qualitative in-depth semi-structured interviews with seven lesbian and gay parents from five families were conducted to explore their unique experience and perspectives on these issues. Discourse analysis was used to facilitate understanding of how lesbian and gay families negotiated the outsider/insider and public/private spheres of the school and communities of which they were a part. Parents identified a number of strategies to address their experiences of homophobia within schools. The findings have implications for how social work recognises and promotes diversity and equality when working with lesbian, gay, bisexual and transgender families, as social workers have a powerful role in supporting families. This involves recognising the strengths of lesbian, gay, bisexual and transgender families in their assessments