Acetone in the Atmosphere of Hong Kong, Abundance, Sources and Photochemical Precursors

Intensive field measurements were carried out at a mountain site and an urban site at the foot of the mountain from September to November 2010 in Hong Kong. Acetone was monitored using both canister air samples and 2,4-dinitrophenylhydrazine cartridges. The spatiotemporal patterns of acetone showed no difference between the two sites (p > 0.05), and the mean acetone mixing ratios on O3 episode days were higher than those on non-O3 episode days at both sites (p < 0.05). The source contributions to ambient acetone at both sites were estimated using a receptor model i.e. Positive Matrix Factorization (PMF). The PMF results showed that vehicular emission and secondary formation made the most important contribution to ambient acetone, followed by the solvent use at both sites. However, the contribution of biogenic emission at the mountain site was significantly higher than that at the urban site, whereas biomass burning made more remarkable contribution at the urban site than that at the mountain site. The mechanism of oxidation formation of acetone was investigated using a photochemical box model. The results indicated that i-butene was the main precursor of secondary acetone at the mountain site, while the oxidation of i-butane was the major source of secondary acetone at the urban site.Department of Civil and Environmental Engineerin

Reconnecting Schools and Neighborhoods: A proposal for School Centered Community Revitalization in Baltimore Maryland

This project explores the concept of school-centered community as a key aspect in assisting urban renewal through architecture. It employs this concept through the architectural design of a middle school in Baltimore, Maryland that has a focus on music. The existing context of an urban site in the Oldtown area is analyzed to generate a solution to the area’s educational problems as well as to provide an urban renewal plan. In order to develop a project that has great potential to succeed, the projects site was specifically chosen based on its context

Elevated immune gene expression is associated with poor reproductive success of urban blue tits

Urban and forest habitats differ in many aspects that can lead to modifications of the immune system of wild animals. Altered parasite communities, pollution, and artificial light at night in cities have been associated with exacerbated inflammatory responses, with possibly negative fitness consequences, but few data are available from free-living animals. Here, we investigate how urbanization affects major immune pathways and experimentally test potentially contributing factors in blue tits (Cyanistes caeruleus) from an urban and forest site. We first compared breeding adults by quantifying the mRNA transcript levels of proteins associated with anti-bacterial, anti-malarial (TLR4, LY86) and anti-helminthic (Type 2 transcription factor GATA3) immune responses. Adult urban and forest blue tits differed in gene expression, with significantly increased TLR4 and GATA3, but not LY86, in the city. We then experimentally tested whether these differences were environmentally induced by cross-fostering eggs between the sites and measuring mRNA transcripts in nestlings. The populations differed in reduced reproductive success, with a lower fledging success and lower fledgling weight recorded at the urban site. This mirrors the findings of our twin study reporting that the urban site was severely resource limited when compared to the forest. Because of low urban survival, robust gene expression data were only obtained from nestlings reared in the forest. Transcript levels in these nestlings showed no (TLR4, LY86), or weak (GATA3), differences according to their origin from forest or city nests, suggesting little genetic or maternal contribution to nestling immune transcript levels. Lastly, to investigate differences in parasite pressure between urban and forest sites, we measured the prevalence of malaria in adult and nestling blood. Prevalence was invariably high across environments and not associated with the transcript levels of the studied immune genes. Our results support the hypothesis that inflammatory pathways are activated in an urban environment and suggest that these differences are most likely induced by environmental factors

How equitable is the scaling up of HIV service provision in South Africa?

OBJECTIVES. To assess the extent of inequalities in availability and utilisation of HIV services across South Africa. DESIGN. Cross-sectional descriptive study. Setting. Three districts reflecting different socio-economic conditions, but with similar levels of HIV infection, were purposively sampled. Outcome measures. Availability and utilisation of HIV services and management and support structures for programmes were assessed through the collection of secondary data supplemented by site visits. RESULTS. There were marked inequalities in service delivery between the three sites. Compared with two poorer sites, clinics at the urban site had greater availability of HIV services, including voluntary counselling and testing (100% v. 52% and 24% respectively), better uptake of this service (59 v. 9 and 5.5 clients per 1 000 adults respectively) and greater distribution of condoms (15.6 v. 8.2 condoms per adult male per year). Extra counsellors had also been employed at the urban site in contrast to the other 2 sites. The urban site also had far more intensive management support and monitoring, with 1 manager per 12 health facilities compared with 1 manager per more than 90 health facilities at the other 2 sites. CONCLUSION. The process of scaling up of HIV services seems to be accentuating inequalities. The urban site in this study was better able to utilise the extra resources. In contrast, the poorer sites have thus far been unable to scale up the response to HIV even with the availability of extra resources. Unless policy makers pay more attention to equity, efficacious interventions may prove to be of limited effectiveness

Influence of Environmental Pollution on Leaf Properties of Urban Plane Trees, Platanus orientalis L.

To investigate whether leaves of plane trees (Platanus orientalis) are damaged by traffic pollution, trees from a megacity (Mashhad, Iran) and a rural area were investigated. Soil and air from the urban centre showed enrichment of several toxic elements, but only lead was enriched in leaves. Leaf size and stomata density were lower at the urban site. At the urban site leaf surfaces were heavily loaded by dust particles but the stomata were not occluded; the cuticle was thinner; other anatomical properties were unaffected suggesting that plane trees can cope with traffic exhaust in megacities

Diurnal concentrations, sources, and cancer risk assessments of 1 PM 2.5 -bound PAHs, NPAHs, and OPAHs in urban, marine and 2 mountain environments

International audienceAmbient measurements of PM2.5-bounded polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs (NPAHs), and oxy-PAHs (OPAHs) were conducted during the summer in Jinan, China, an urban site, and at Tuoji island and Mt. Tai, two background locations. 3.5 h and 11.5 h sampling intervals in daytime and nighttime were utilized to research the diurnal variations of PAHs, NPAHs, and OPAHs. The concentrations of PAHs, NPAHs, and OPAHs were highest at the urban site and lowest at the marine site. The diurnal patterns of PAHs and NPAHs at the urban and marine sites were dissimilar to those observed at the mountain site partly due to the influence of the boundary layer. Vehicle emissions at the urban site made a large contribution to high molecular weight PAHs. 1N-PYR and 7N-BaA during morning and night sampling periods in JN were relatively high. Fossil fuel combustion and biomass burning were the main sources for all three sites during the sampling periods. The air masses at the marine and mountain sites were strongly impacted by photo-degradation, and the air masses at the marine site were the most aged. Secondary formation of NPAHs was mainly initiated by OH radicals at all the three sites and was strongest at the marine site. Secondary formation was most efficient during the daytime at the urban and mountain sites and during morning periods at the marine site. The average excess cancer risk from inhalation (ECR) for 70 years' life span at the urban site was much higher than those calculated for the background sites

How equitable is the scaling up of HIV service provision in South Africa?

Objectives. To assess the extent of inequalities in availability and utilisation of HIV services across  South Africa.Design. Cross-sectional descriptive study.Setting. Three districts reflecting different socio-economic conditions, but with similar levels of HIV  infection, were purposively sampled.Outcome measures. Availability and utilisation of HIV services and management and support  structures for programmes were assessed through the collection of secondary data supplemented by site visits.Results. There were marked inequalities in service delivery between the three sites. Compared with  two poorer sites, clinics at the urban site had greater availability of HIV services, including voluntary counselling and testing (100% v. 52% and 24% respectively), better uptake of this service (59 v.9  and 5.5 clients per 1 000 adults respectively) and greater distribution of condoms (15.6 v. 8.2 condoms per adult male per year). Extra counsellors had also been employed at the urban site in contrast to the other 2 sites. The urban site also had far more intensive management support and monitoring, with 1 manager per 12 health facilities compared with 1 manager per more than 90 health facilities at the  other 2 sites.Conclusion. The process of scaling up of HIV services seems to be accentuating inequalities. The  urban site in this study was better able to utilise the extra resources. In contrast, the poorer sites have thus far been u':lable to scale up the response to HIV even with the availability of extra resources. Unless policy makers pay more attention to equity, efficacious interventions may prove to be of limited effectiveness