Integrating knowledge on green infrastructure, health and well-being in ageing populations: Principles for research and practice

Ageing and urbanisation pose significant challenges for public health and urban planning. Ageing populations are at particular risk from hazards arising from urbanisation processes, some of which are in turn exacerbated by climate change. One approach for mitigating the negative effects of urbanisation on ageing populations is the leveraging of the beneficial effects of urban green infrastructure as a public health intervention in the planning process. We assessed the potential of available theoretical frameworks to provide the context for such leverage. This involved active engagement with academics and practitioners specialising in ageing, green infrastructure and health and well-being through a knowledge-brokering approach. We concluded that an integrated and comprehensive framework on the socio-cultural-ecological determinants of health is lacking. To address this, we present a set of principles for overcoming challenges to knowledge integration when working at the intersection of green infrastructure, ageing, health and well-being. Our findings-and the co-production process used to generate them-have wider significance for trans-disciplinary research into the benefits of the natural environment to human health and well-being as well as other complex and interconnected topics associated with global grand challenges.

Paper2GIS: improving accessibility without limiting analytical potential in Participatory Mapping

Participatory Mapping encompasses a broad spectrum of methods, each with advantages and limitations that can influence the degree to which the target audience is able to participate and the veracity of the data collected. Whilst being an efficient means to gather spatial data, the accessibility of online methods is limited by digital divides. Conversely, whilst non-digital approaches are more accessible to participants, data collected in this way are typically more challenging to analyse and often necessitate researcher interpretation, limiting their use in decision-making. We therefore present 'Paper2GIS', a novel sketch mapping tool that automatically extracts mark-up drawn onto paper maps and stores it in a geospatial database. The approach embodied in our tool simultaneously limits the technical burden placed on the participant and generates data comparable to that of a digital system without the subjectivity of manual digitisation. This improves accessibility, whilst simultaneously facilitating spatial analyses that are usually not possible with paper-based mapping exercises. A case study is presented to address two energy planning questions of the residents in the Outer Hebrides, UK. The results demonstrate that accessibility can be improved without impacting the potential for spatial analysis, widening participation to further democratise decision-making.

Spatiotemporal dynamics of urban climate during the wet-dry season transition in a tropical African city

The Urban Heat Island effect has been the focus of several studies concerned with the effects of urbanisation on human and ecosystem health. Humidity, however, remains much less studied, although it is useful for characterising human thermal comfort, the Urban Dryness Island effect and vegetation development. Furthermore, variability in microscale climate due to differences in land cover is increasingly crucial for understanding urbanisation effects on the health and wellbeing of living organisms. We used regression analysis to investigate the spatial and temporal dynamics of temperature, humidity and heat index in the tropical African city of Kampala, Uganda. We gathered data during the wet to dry season transition from 22 locations that represent the wide range of urban morphological differences in Kampala. Our analysis showed that the advancement of the dry season increased variability of climate in Kampala and that the most built-up locations experienced the most profound seasonal changes in climate. This work stresses the need to account for water availability and humidity to improve our understanding of human and ecosystem health in cities.

Estimating multiple greenspace exposure types and their associations with neighbourhood premature mortality: A socioecological study

BACKGROUND

Greenspace exposures are often measured using single exposure metrics, which can lead to conflicting results. Existing methodologies are limited in their ability to estimate greenspace exposure comprehensively. We demonstrate new methods for estimating single and combined greenspace exposure metrics, representing multiple exposure types that combine impacts at various scales. We also investigate the association between those greenspace exposure types and premature mortality.

METHODS

We used geospatial data and spatial analytics to model and map greenspace availability, accessibility and eye-level visibility exposure metrics. These were harmonised and standardised to create a novel composite greenspace exposure index (CGEI). Using these metrics, we investigated associations between greenspace exposures and years of potential life lost (YPLL) for 1673 neighbourhoods applying spatial autoregressive models. We also investigated the variations in these associations in conjunction with levels of socioeconomic deprivation based on the index of multiple deprivations.

RESULTS

Our new CGEI metric provides the opportunity to estimate spatially explicit total greenspace exposure. We found that a 1-unit increase in neighbourhood CGEI was associated with approximately a 10-year reduction in YPLL. Meaning a 0.1 increment or 10% increase in the CGEI is associated with an approximately one year lower premature mortality value. A single 1-unit increase in greenspace availability was associated with a YPLL reduction of 9.8 years, whereas greenness visibility related to a reduction of 6.14 years. We found no significant association between greenspace accessibility and YPLL. Our results further identified divergent trends in the relations between greenspace exposure types (e.g. availability vs. accessibility) and levels of socioeconomic deprivation (e.g. least vs. most).

CONCLUSION

Our methods and metrics provide a novel approach to the assessment of multiple greenspace exposure types, and can be linked to the broader exposome framework. Our results showed that a higher composite greenspace exposure is associated with lower premature mortality.

Pathways linking biodiversity to human health: A conceptual framework

Biodiversity is a cornerstone of human health and well-being. However, while evidence of the contributions of nature to human health is rapidly building, research into how biodiversity relates to human health remains limited in important respects. In particular, a better mechanistic understanding of the range of pathways through which biodiversity can influence human health is needed. These pathways relate to both psychological and social processes as well as biophysical processes. Building on evidence from across the natural, social and health sciences, we present a conceptual framework organizing the pathways linking biodiversity to human health. Four domains of pathways-both beneficial as well as harmful-link biodiversity with human health: (i) reducing harm (e.g. provision of medicines, decreasing exposure to air and noise pollution); (ii) restoring capacities (e.g. attention restoration, stress reduction); (iii) building capacities (e.g. promoting physical activity, transcendent experiences); and (iv) causing harm (e.g. dangerous wildlife, zoonotic diseases, allergens). We discuss how to test components of the biodiversity-health framework with available analytical approaches and existing datasets. In a world with accelerating declines in biodiversity, profound land-use change, and an increase in non-communicable and zoonotic diseases globally, greater understanding of these pathways can reinforce biodiversity conservation as a strategy for the promotion of health for both people and nature. We conclude by identifying research avenues and recommendations for policy and practice to foster biodiversity-focused public health actions.

Modelling and mapping eye-level greenness visibility exposure using multi-source data at high spatial resolutions

The visibility of natural greenness is associated with several health benefits along multiple pathways, including stress recovery and attention restoration mechanisms. However, existing methodologies are inadequate for capturing eye-level greenness visibility exposure at high spatial resolutions for observers located on the ground. As a response, we developed an innovative methodological approach to model and map eye-level greenness visibility exposure for 5 m interval locations within a large study area. We used multi-source spatial data and applied viewshed analysis in conjunction with a distance decay model to compute a novel Viewshed Greenness Visibility Index (VGVI) at more than 86 million observer locations. We compared our eye-level visibility exposure map with traditional top-down greenness exposure metrics such as Normalised Differential Vegetation Index (NDVI) and a Street view based Green View Index (SGVI). Furthermore, we compared greenness visibility at street-only locations with total neighbourhood greenness visibility. We found strong to moderate correlations (r = 0.65-0.42, p < 0.05) between greenness visibility and mean NDVI, with a decreasing trend in correlation strength at increasing buffer distances from observer locations. Our findings suggest that top-down and eye-level measurements of greenness are two distinct metrics for assessing greenness exposure. Additionally, VGVI showed a strong correlation (r = 0.481, p < 0.01) with SGVI. Although the new VGVI has good agreement with existing street view based measures, we found that street-only greenness visibility values are not wholly representative of total neighbourhood visibility due to the under-representation of visible greenness in locations such as backyards and community parks. Our new methodology overcomes such underestimations, is easily transferable, and offers a computationally efficient approach to assessing eye-level greenness exposure.

Urban green infrastructure size, quality and proximity and health outcomes in older populations

Background

A city's multi-functional network of green and blue spaces has an important role underpinning the health and wellbeing of its residents. Although evidence of positive links between nature and health is plentiful, little is known about which particular aspects of green and blue spaces are most influential, and how benefits might vary between social groups and age.

Methods

We used a green infrastructure (GI) approach combining a high-resolution spatial dataset of land-cover and function with area-level demographic and socio-economic data. A comprehensive characterisation of the Greater Manchester UK city region was generated. The GI attributes were used in step-wise multi-level regression analyses to test for associations between population chronic morbidity and the functional, physical and spatial components of GI across an urban socio-demographic gradient.

Results

Individual GI attributes were significantly associated with health in all socio-demographic contexts; even when associations between health and overall green cover were non-significant. For areas with having higher proportions of older people ('older neighbourhoods'), associations were found between health and land-cover diversity, informal greenery and patch size in high income areas. In lower income areas, health was predicted by proximity to public parks and recreation land.

Conclusions

A nuanced description of greenspace in terms of quality, cover type, diversity explains more variation in population health than a single metric such as percentage green cover. People in urban neighbourhoods that have older age populations and lower income are disproportionately healthy if their neighbourhoods contain accessible, good quality public greenspace. This has implications for strategies to decrease health inequalities and inform international initiatives, such as the World Health Organisation's Age-Friendly Cities programme.

Key messages

A nuanced description of green and blue space in terms of quality, cover type, diversity explains more variation in population health than a single metric such as percentage green cover. People in urban neighbourhoods that have older age populations and lower income are disproportionately healthy if their neighbourhoods contain accessible, good quality public greenspace.

Spatial dimensions of the influence of urban green-blue spaces on human health: A systematic review

BACKGROUND

There is an increasing volume of literature investigating the links between urban environments and human health, much of which involves spatial conceptualisations and research designs involving various aspects of geographical information science. Despite intensifying research interest, there has been little systematic investigation of pragmatic methodological concerns, such as how studies are realised in terms of the types of data that are gathered and the analytical techniques that are applied, both of which have the potential to impact results. The aim of this systematic review is, therefore, to understand how spatial scale, datasets, methods, and analytics are currently applied in studies investigating the relationship between green and blue spaces and human health in urban areas.

METHOD

We systematically reviewed 93 articles following PRISMA protocol, extracted information regarding different spatial dimensions, and synthesised them in relation to various health indicators.

RESULTS AND DISCUSSION

We found a preponderance of the use of neighbourhood-scale in these studies, and a majority of the studies utilised land-use and vegetation indices gleaned from moderate resolution satellite imagery. We also observed the frequent adoption of fixed spatial units for measuring exposure to green and blue spaces based on physical proximity, typically ranging between 30 and 5000 m. The conceptual frameworks of the studies (e.g., the focus on physical vs. mental health or the definition of exposure to green space) were found to have an influence on the strength of association between exposure and health outcomes. Additionally, the strength and significance of associations also varied by study design, something which has not been considered systematically.

CONCLUSION

On the basis of our findings, we propose a set of recommendations for standardised protocols and methods for the evaluation of the impact of green-blue spaces on health. Our analysis suggests that future studies should consider conducting analyses at finer spatial scales and employing multiple exposure assessment methods to achieve a comprehensive and comparable evaluation of the association between greenspace and health along multiple pathways.

Response rate to a single dose of vinblastine administered to dogs with treatment-naive multicentric lymphoma

Vincristine is included in vincristine, cyclophosphamide, doxorubicin and prednisone (CHOP) chemotherapy protocols, which are the gold-standard treatment for high-grade canine lymphoma. Vincristine can result in relatively high rates of gastrointestinal toxicity, whereas vinblastine is generally well tolerated and thus may represent an under-utilized and minimally toxic alternative to vincristine. Our objective was to determine the response rate and toxicity associated with a single dose of vinblastine administered to dogs with treatment-naïve, intermediate to large-cell, multicentric lymphoma. Twenty client-owned dogs were enrolled with signed owner consent. A Simon's minimax, phase II, two-stage trial was performed to test the efficacy of vinblastine administered at 2 mg/m² IV followed by a pilot trial of vinblastine at 2.5 mg/m² . No dogs were administered concurrent steroids or other chemotherapy. One out of 14 dogs receiving vinblastine at 2 mg/m² demonstrated a partial response. Three out of five dogs demonstrated a partial response to vinblastine at 2.5 mg/m² . Gastrointestinal toxicity was infrequent and low grade for both groups. The majority of dogs (80%) in the 2.5 mg/m² dosing group developed neutropenia 1-week post administration. Vinblastine was well tolerated but minimally efficacious at a dose of 2 mg/m² IV in dogs with treatment-naive, multicentric lymphoma. Because of poor response rates, treatment at this dose is not recommended. A small subset of dogs administered 2.5 mg/m² had significantly improved response rates (P = 0.04), suggesting that higher doses may have improved efficacy, although further research is indicated to confirm these preliminary findings.

Customizing the coefficients of urban domestic pollutant discharge and their driving mechanisms: Evidence from the Taihu Basin, China

Discharge of urban domestic pollution has risen sharply during China's extensive urbanization. Together with understanding the complexity of influencing factors underpinning this rise, it has become a pressing issue to estimate total discharge and illustrate its driving mechanism scientifically. This paper reports on the monitoring of discharge from 36 sampling sites in selected residential districts in the heavily polluted Taihu Basin, China. The data were used to estimate the total amount of discharge, to develop corresponding urban domestic pollutant discharge coefficients and to analyse associated spatial patterns. Data from a questionnaire survey of over 1000 households in downtown, suburb and market town areas were then used to apply an econometric model in order to distinguish driving mechanisms. The urban domestic pollutant discharge coefficients developed in this paper are generally smaller than those reported nationally for China, based on more generalised data, decaying from city centres to the urban periphery. This study quantifies the amount of discharge and also demonstrates that urban domestic pollutant discharge is driven by multiple factors. For example, urban domestic pollution discharge rates were positively correlated with income and female-dominated households also tend to discharge more wastewater. Other factors were found to have negative correlations, such as sewage treatment rates, awareness of environmental protection, age and degree of education. As well as providing new and refined data on urban pollution discharge characteristics, the research in this paper also demonstrates the utility of combining household questionnaire and sample monitoring data in order to yield greater insights into the causes of typical polluting behaviour in Chinese neighbourhoods.

Influence of walking route choice on primary school children's exposure to air pollution--A proof of concept study using simulation

This study developed a walking network for the Greater Manchester area (UK). The walking network allows routes to be calculated either based on the shortest duration or based on the lowest cumulative nitrogen dioxide (NO2) or particulate matter (PM10) exposure. The aim of this study was to analyse the costs and benefits of faster routes versus lower pollution exposure for walking routes to primary schools. Random samples of primary schools and residential addresses were used to generate 100,000 hypothetical school routes. For 60% (59,992) and 40% (40,460) an alternative low NO2 and PM10 route was found, respectively. The median change in travel time (NO2: 4.5s, PM10: 0.5s) and average route exposure (NO2: -0.40 μg/m(3), PM10: -0.03 μg/m(3)) was small. However, quantile regression analysis indicated that for 50% of routes a 1% increase in travel time was associated with a 1.5% decrease in NO2 and PM10 exposure. The results of this study suggest that the relative decrease in pollution exposure on low pollution routes tends to be greater than the relative increase in route length. This supports the idea that a route planning tool identifying less polluted routes to primary schools could help deliver potential health benefits for children.

A multicentre study of air pollution exposure and childhood asthma prevalence: the ESCAPE project

The aim of this study was to determine the effect of six traffic-related air pollution metrics (nitrogen dioxide, nitrogen oxides, particulate matter with an aerodynamic diameter <10 μm (PM10), PM2.5, coarse particulate matter and PM2.5 absorbance) on childhood asthma and wheeze prevalence in five European birth cohorts: MAAS (England, UK), BAMSE (Sweden), PIAMA (the Netherlands), GINI and LISA (both Germany, divided into north and south areas). Land-use regression models were developed for each study area and used to estimate outdoor air pollution exposure at the home address of each child. Information on asthma and current wheeze prevalence at the ages of 4-5 and 8-10 years was collected using validated questionnaires. Multiple logistic regression was used to analyse the association between pollutant exposure and asthma within each cohort. Random-effects meta-analyses were used to combine effect estimates from individual cohorts. The meta-analyses showed no significant association between asthma prevalence and air pollution exposure (e.g. adjusted OR (95%CI) for asthma at age 8-10 years and exposure at the birth address (n=10377): 1.10 (0.81-1.49) per 10 μg · m(-3) nitrogen dioxide; 0.88 (0.63-1.24) per 10 μg · m(-3) PM10; 1.23 (0.78-1.95) per 5 μg · m(-3) PM2.5). This result was consistently found in initial crude models, adjusted models and further sensitivity analyses. This study found no significant association between air pollution exposure and childhood asthma prevalence in five European birth cohorts.

Performance of multi-city land use regression models for nitrogen dioxide and fine particles

BACKGROUND

Land use regression (LUR) models have been developed mostly to explain intraurban variations in air pollution based on often small local monitoring campaigns. Transferability of LUR models from city to city has been investigated, but little is known about the performance of models based on large numbers of monitoring sites covering a large area.

OBJECTIVES

We aimed to develop European and regional LUR models and to examine their transferability to areas not used for model development.

METHODS

We evaluated LUR models for nitrogen dioxide (NO2) and particulate matter (PM; PM2.5, PM2.5 absorbance) by combining standardized measurement data from 17 (PM) and 23 (NO2) ESCAPE (European Study of Cohorts for Air Pollution Effects) study areas across 14 European countries for PM and NO2. Models were evaluated with cross-validation (CV) and hold-out validation (HV). We investigated the transferability of the models by successively excluding each study area from model building.

RESULTS

The European model explained 56% of the concentration variability across all sites for NO2, 86% for PM2.5, and 70% for PM2.5 absorbance. The HV R2s were only slightly lower than the model R2 (NO2, 54%; PM2.5, 80%; PM2.5 absorbance, 70%). The European NO2, PM2.5, and PM2.5 absorbance models explained a median of 59%, 48%, and 70% of within-area variability in individual areas. The transferred models predicted a modest-to-large fraction of variability in areas that were excluded from model building (median R2: NO2, 59%; PM2.5, 42%; PM2.5 absorbance, 67%).

CONCLUSIONS

Using a large data set from 23 European study areas, we were able to develop LUR models for NO2 and PM metrics that predicted measurements made at independent sites and areas reasonably well. This finding is useful for assessing exposure in health studies conducted in areas where no measurements were conducted.

Long-term exposure to PM10 and NO2 in association with lung volume and airway resistance in the MAAS birth cohort

BACKGROUND

Findings from previous studies on the effects of air pollution exposure on lung function during childhood have been inconsistent. A common limitation has been the quality of exposure data used, and few studies have modeled exposure longitudinally throughout early life.

OBJECTIVES

We sought to study the long-term effects of exposure to particulate matter with an aerodynamic diameter ≤ 10 μm (PM10) and to nitrogen dioxide (NO2) on specific airway resistance (sR(aw)) and forced expiratory volume in 1 sec (FEV1) before and after bronchodilator treatment. Subjects were from the Manchester Asthma and Allergy Study (MAAS) birth cohort (n = 1,185).

METHODS

Spirometry was performed during clinic visits at ages 3, 5, 8, and 11 years. Individual-level PM10 and NO2 exposures were estimated from birth to 11 years of age through a microenvironmental exposure model. Longitudinal and cross-sectional associations were estimated using generalized estimating equations and multivariable linear regression models.

RESULTS

Lifetime exposure to PM10 and NO2 was associated with significantly less growth in FEV1 (percent predicted) over time, both before (-1.37%; 95% CI: -2.52, -0.23 for a 1-unit increase in PM10 and -0.83%; 95% CI: -1.39, -0.28 for a 1-unit increase in NO2) and after bronchodilator treatment (-3.59%; 95% CI: -5.36, -1.83 and -1.20%; 95% CI: -1.97, -0.43, respectively). We found no association between lifetime exposure and sR(aw) over time. Cross-sectional analyses of detailed exposure estimates for the summer and winter before 11 years of age and lung function at 11 years indicated no significant associations.

CONCLUSIONS

Long-term PM10 and NO2 exposures were associated with small but statistically significant reductions in lung volume growth in children of elementary-school age.

Effects of long-term exposure to PM10 and NO2 on asthma and wheeze in a prospective birth cohort

BACKGROUND

Epidemiological studies on the effect of urban air pollution on childhood asthma have shown conflicting results and so far no consistent association has emerged. However, a common limitation in previous studies has been exposure misclassification leading to uncertainties in risk estimates.The aim of this study was to analyse the effects of long-term exposure to particulate matter (PM10) and nitrogen dioxide (NO2) on the prevalence of asthma and wheeze within a population-based birth cohort--the Manchester Asthma and Allergy Study (MAAS).

METHODS

The prevalence of asthma and current wheeze within the cohort (N=1185) was determined through parental questionnaires at ages 3, 5, 8 and 11 years. The typical monthly PM10 and NO2 exposure of each child was estimated through a novel microenvironmental exposure model from birth to age 11. The association between exposure and asthma or wheeze was analysed using generalised estimating equations and multiple logistic regression.

RESULTS

The range of asthma prevalence was 15.2-23.3%, with the lowest prevalence at age 3 and the highest at age 5. The prevalence of current wheeze decreased from ages 3 to 8 (23.7-18%). The mean NO2 exposure decreased from the 1st year of life (21.7 µg/m(3)) to the 11th year of life (16.0 µg/m(3)). The mean PM10 exposure showed a smaller decrease (12.8 -10.7 µg/m(3)). The statistical analysis showed no significant association between the exposures and either outcome.

CONCLUSIONS

No evidence of a significant association between long-term exposure to PM10 and NO2 and the prevalence of either asthma or wheeze was found.

Development of land use regression models for particle composition in twenty study areas in Europe

Land Use Regression (LUR) models have been used to describe and model spatial variability of annual mean concentrations of traffic related pollutants such as nitrogen dioxide (NO2), nitrogen oxides (NOx) and particulate matter (PM). No models have yet been published of elemental composition. As part of the ESCAPE project, we measured the elemental composition in both the PM10 and PM2.5 fraction sizes at 20 sites in each of 20 study areas across Europe. LUR models for eight a priori selected elements (copper (Cu), iron (Fe), potassium (K), nickel (Ni), sulfur (S), silicon (Si), vanadium (V), and zinc (Zn)) were developed. Good models were developed for Cu, Fe, and Zn in both fractions (PM10 and PM2.5) explaining on average between 67 and 79% of the concentration variance (R(2)) with a large variability between areas. Traffic variables were the dominant predictors, reflecting nontailpipe emissions. Models for V and S in the PM10 and PM2.5 fractions and Si, Ni, and K in the PM10 fraction performed moderately with R(2) ranging from 50 to 61%. Si, NI, and K models for PM2.5 performed poorest with R(2) under 50%. The LUR models are used to estimate exposures to elemental composition in the health studies involved in ESCAPE.

Evaluation of land use regression models for NO2 and particulate matter in 20 European study areas: the ESCAPE project

Land use regression models (LUR) frequently use leave-one-out-cross-validation (LOOCV) to assess model fit, but recent studies suggested that this may overestimate predictive ability in independent data sets. Our aim was to evaluate LUR models for nitrogen dioxide (NO2) and particulate matter (PM) components exploiting the high correlation between concentrations of PM metrics and NO2. LUR models have been developed for NO2, PM2.5 absorbance, and copper (Cu) in PM10 based on 20 sites in each of the 20 study areas of the ESCAPE project. Models were evaluated with LOOCV and "hold-out evaluation (HEV)" using the correlation of predicted NO2 or PM concentrations with measured NO2 concentrations at the 20 additional NO2 sites in each area. For NO2, PM2.5 absorbance and PM10 Cu, the median LOOCV R(2)s were 0.83, 0.81, and 0.76 whereas the median HEV R(2) were 0.52, 0.44, and 0.40. There was a positive association between the LOOCV R(2) and HEV R(2) for PM2.5 absorbance and PM10 Cu. Our results confirm that the predictive ability of LUR models based on relatively small training sets is overestimated by the LOOCV R(2)s. Nevertheless, in most areas LUR models still explained a substantial fraction of the variation of concentrations measured at independent sites.

Development of Land Use Regression models for PM(2.5), PM(2.5) absorbance, PM(10) and PM(coarse) in 20 European study areas; results of the ESCAPE project

Land Use Regression (LUR) models have been used increasingly for modeling small-scale spatial variation in air pollution concentrations and estimating individual exposure for participants of cohort studies. Within the ESCAPE project, concentrations of PM(2.5), PM(2.5) absorbance, PM(10), and PM(coarse) were measured in 20 European study areas at 20 sites per area. GIS-derived predictor variables (e.g., traffic intensity, population, and land-use) were evaluated to model spatial variation of annual average concentrations for each study area. The median model explained variance (R(2)) was 71% for PM(2.5) (range across study areas 35-94%). Model R(2) was higher for PM(2.5) absorbance (median 89%, range 56-97%) and lower for PM(coarse) (median 68%, range 32- 81%). Models included between two and five predictor variables, with various traffic indicators as the most common predictors. Lower R(2) was related to small concentration variability or limited availability of predictor variables, especially traffic intensity. Cross validation R(2) results were on average 8-11% lower than model R(2). Careful selection of monitoring sites, examination of influential observations and skewed variable distributions were essential for developing stable LUR models. The final LUR models are used to estimate air pollution concentrations at the home addresses of participants in the health studies involved in ESCAPE.

Development of Land Use Regression models for PM(2.5), PM(2.5) absorbance, PM(10) and PM(coarse) in 20 European study areas; results of the ESCAPE project

Land Use Regression (LUR) models have been used increasingly for modeling small-scale spatial variation in air pollution concentrations and estimating individual exposure for participants of cohort studies. Within the ESCAPE project, concentrations of PM(2.5), PM(2.5) absorbance, PM(10), and PM(coarse) were measured in 20 European study areas at 20 sites per area. GIS-derived predictor variables (e.g., traffic intensity, population, and land-use) were evaluated to model spatial variation of annual average concentrations for each study area. The median model explained variance (R(2)) was 71% for PM(2.5) (range across study areas 35-94%). Model R(2) was higher for PM(2.5) absorbance (median 89%, range 56-97%) and lower for PM(coarse) (median 68%, range 32- 81%). Models included between two and five predictor variables, with various traffic indicators as the most common predictors. Lower R(2) was related to small concentration variability or limited availability of predictor variables, especially traffic intensity. Cross validation R(2) results were on average 8-11% lower than model R(2). Careful selection of monitoring sites, examination of influential observations and skewed variable distributions were essential for developing stable LUR models. The final LUR models are used to estimate air pollution concentrations at the home addresses of participants in the health studies involved in ESCAPE.

Magnetic Meckel's: an unusual case report of foreign body ingestion

Foreign body ingestion in children is common. Most items pass spontaneously, however rarer cases may result in obstruction and or perforation. Ingestion of multiple magnetic items can be more troublesome, as a consequence of the ability of the items to attract across different sections of bowel, or by coalescing to form a larger foreign body. Very few cases of foreign body ingestion have led to the presentation of a complicated Meckel's diverticulum. We present of a case of an adolescent boy with intestinal obstruction secondary to multiple magnetic foreign body ingestion and sequestration within a Meckel's diverticulum.

Modelling air pollution for epidemiologic research--part II: predicting temporal variation through land use regression

Over recent years land use regression (LUR) has become a frequently used method in air pollution exposure studies, as it can model intra-urban variation in pollutant concentrations at a fine spatial scale. However, very few studies have used the LUR methodology to also model the temporal variation in air pollution exposure. The aim of this study is to estimate annual mean NO(2) and PM(10) concentrations from 1996 to 2008 for Greater Manchester using land use regression models. The results from these models will be used in the Manchester Asthma and Allergy Study (MAAS) birth cohort to determine health effects of air pollution exposure. The Greater Manchester LUR model for 2005 was recalibrated using interpolated and adjusted NO(2) and PM(10) concentrations as dependent variables for 1996-2008. In addition, temporally resolved variables were available for traffic intensity and PM(10) emissions. To validate the resulting LUR models, they were applied to the locations of automatic monitoring stations and the estimated concentrations were compared against measured concentrations. The 2005 LUR models were successfully recalibrated, providing individual models for each year from 1996 to 2008. When applied to the monitoring stations the mean prediction error (MPE) for NO(2) concentrations for all stations and years was -0.8μg/m³ and the root mean squared error (RMSE) was 6.7μg/m³. For PM(10) concentrations the MPE was 0.8μg/m³ and the RMSE was 3.4μg/m³. These results indicate that it is possible to model temporal variation in air pollution through LUR with relatively small prediction errors. It is likely that most previous LUR studies did not include temporal variation, because they were based on short term monitoring campaigns and did not have historic pollution data. The advantage of this study is that it uses data from an air dispersion model, which provided concentrations for 2005 and 2010, and therefore allowed extrapolation over a longer time period.

Modelling air pollution for epidemiologic research--Part I: A novel approach combining land use regression and air dispersion

A common limitation of epidemiological studies on health effects of air pollution is the quality of exposure data available for study participants. Exposure data derived from urban monitoring networks is usually not adequately representative of the spatial variation of pollutants, while personal monitoring campaigns are often not feasible, due to time and cost restrictions. Therefore, many studies now rely on empirical modelling techniques, such as land use regression (LUR), to estimate pollution exposure. However, LUR still requires a quantity of specifically measured data to develop a model, which is usually derived from a dedicated monitoring campaign. A dedicated air dispersion modelling exercise is also possible but is similarly resource and data intensive. This study adopted a novel approach to LUR, which utilised existing data from an air dispersion model rather than monitored data. There are several advantages to such an approach such as a larger number of sites to develop the LUR model compared to monitored data. Furthermore, through this approach the LUR model can be adapted to predict temporal variation as well as spatial variation. The aim of this study was to develop two LUR models for an epidemiologic study based in Greater Manchester by using modelled NO(2) and PM(10) concentrations as dependent variables, and traffic intensity, emissions, land use and physical geography as potential predictor variables. The LUR models were validated through a set aside "validation" dataset and data from monitoring stations. The final models for PM(10) and NO(2) comprised nine and eight predictor variables respectively and had determination coefficients (R²) of 0.71 (PM(10): Adj. R²=0.70, F=54.89, p<0.001, NO(2): Adj. R²=0.70, F=62.04, p<0.001). Validation of the models using the validation data and measured data showed that the R² decreases compared to the final models, except for NO(2) validation in the measured data (validation data: PM(10): R²=0.33, NO(2): R²=0.62; measured data: PM(10): R²=0.56, NO(2): R²=0.86). The validation further showed low mean prediction errors and root mean squared errors for both models.

Identification and verification of ultrafine particle affinity zones in urban neighbourhoods: sample design and data pre-processing

A methodology is presented and validated through which long-term fixed site air quality measurements are used to characterise and remove temporal signals in sample-based measurements which have good spatial coverage but poor temporal resolution. The work has been carried out specifically to provide a spatial dataset of atmospheric ultrafine particle (UFP < 100 nm) data for ongoing epidemiologic cohort analysis but the method is readily transferable to wider epidemiologic investigations and research into the health effects of other pollutant species.

Serotonin transporter polymorphism, memory and hippocampal volume in the elderly: association and interaction with cortisol

The s allele variant of the serotonin transporter gene (5-HTT) has recently been observed to moderate the relationship of stress to depression and anxiety. To date no study has considered interactive effects of 5-HTT genotype, stress and hypothalamic-pituitary-adrenal (HPA) function on cognition in healthy, older adults, which may reflect developmental, functional or neurodegenerative effects of the serotonin transporter polymorphism. We investigated whether 5-HTT genotype interacts with cumulative life stress and HPA-axis measures of waking and diurnal cortisol slope to impact cognition in 154 non-depressed, older adults. Structural images of hippocampal volume were acquired on a subsample of 56 participants. The 5-HTT s allele was associated with both significantly lower delayed recall and higher waking cortisol levels. Presence of the s allele interacted with higher waking cortisol to negatively impact memory. We also observed a significant interaction of higher waking cortisol and the s allele on lower hippocampal volume. Smaller hippocampi and higher cortisol were associated with lower delayed recall only in s allele carriers. No impact or interactions of cumulative life stress with 5-HTT or cortisol were observed. This is the first investigation to identify an association of the 5-HTT s allele with poorer memory function in older adults. The interactive effects of the s allele and waking cortisol levels on reduced hippocampal volume and lower memory suggest that the negative effect of the serotonin polymorphism on memory is mediated by the HPA axis. Further, given the significant association of the s allele with higher waking cortisol in our investigation, future studies may be needed to evaluate the impact of the serotonin transporter polymorphism on any neuropsychiatric or behavioral outcome which is influenced by HPA axis function in older adults.

A study of the aetiology of pseudopregnancy in the bitch and the effect of cabergoline therapy

Thirty-two permanently pseudopregnant bitches were treated with the anti-prolactin drug cabergoline. They had all been ovariohysterectomised up to five months after their last season, in some cases over two years previously, when most were reported as showing no signs of the condition. The clinical signs were mainly behavioural, the majority being aggressive, and a small number were lactating. The efficiency of the cabergoline therapy was classified by the owners as 'excellent' or 'good' in 50 per cent of the cases, and fair in 36 per cent. The rate of success was markedly better than in similar cases treated with reproductive steroids. In all but one of the bitches, the plasma prolactin concentrations were basal.

Effect and mechanisms of the anti-prolactin drug cabergoline on pseudopregnancy in the bitch

A potent anti-prolactin drug, cabergoline, administered orally for five days, was clinically successful in treating three different clinical manifestations of pseudopregnancy in referred bitches. The clinical conditions treated were categorised as standard pseudopregnant bitches (n = 8), those previously unsuccessfully treated with hormones (n = 10) and those which had behavioural pseudopregnancy following ovariohysterectomy (n = 8). The number of bitches whose owners reported a 'good' response was seven out of eight, six out of 10 and six out of eight, respectively. There were very few side effects in that only one bitch vomited following treatment. The clinical response did not necessarily appear to be related to an alteration in circulating prolactin concentrations, suggesting that the drug may have a direct effect on the tissues as well as in most cases reducing the plasma prolactin concentrations.

Upper eyelid retraction in the absence of other evidence for progressive ophthalmopathy is associated with eye muscle autoantibodies

We have studied 25 clinically euthyroid patients with eyelid lag and retraction referred to thyroid/eye clinic for clinical and orbital imaging evidence of extraocular eye muscle (EM) involvement, evidence of progressive ophthalmopathy and serum antibodies reactive with EM membrane antigens in immunoblotting. Fourteen patients had Graves' hyperthyroidism, 5 had Hashimoto's thyroiditis, and 6 had euthyroid Graves' disease. By carrying out orbital imaging we showed EM abnormalities in 10 of 23 patients (43%). Serum antibodies reactive with EM membrane antigens were detected in 96% of patients. Antibodies reactive with a 64-kDa antigen were detected in 66% of patients, while those reactive with 35-, 55-, and 95-kDa antigens were found in 21, 33, and 25% of patients, respectively. Antibody prevalences compared to normals were significantly different (P < 0.005) only for the 64-kDa protein. The prevalence and the degree of reactivity of 64-kDa antibodies were significantly different in patients with abnormal EM compared to those with normal EM at orbital imaging (P < 0.04 and P < 0.01, respectively). The results of this work suggest that in some patients inflammation of the eyelid muscles may be an isolated feature of ophthalmopathy and remains as the only sign of a "subclinical" eye disease in patients with thyroid autoimmunity.

Relief of subglottic stenosis by anterior cricoid resection: an operation for the difficult case

Anterior cricoid resection is an effective procedure to relieve subglottic stenosis. This is well documented in adults, although reports of the procedure in growing airways are limited. Over an 11-year period, seven pediatric patients underwent anterior cricoid resection for recalcitrant subglottic stenosis. In four patients, the stricture was secondary to prolonged intubation, one developed subglottic stenosis following a high placement of tracheostomy for epiglottitis and another had congenital subglottic stenosis. One child had subglottic stenosis combined with laryngotracheoesophageal cleft and more distally located tracheoesophageal fistula. All patients had failed to respond to previous treatment: dilatations (3 to 20), steroid injection (3 patients), and Evan's tracheoplasty (2 patients). All patients had an excellent result from anterior cricoid resection. The median age of children undergoing anterior cricoid resection was 3 years. There was no mortality. Tracheostomy decannulation was accomplished within 12 weeks following operation in all patients. It was necessary to remove a tracheal granuloma in one patient. Anterior cricoid wedge resection leaving the posterior portion of the cricoid in place is done to avoid recurrent nerve injury. It is a relatively simple and effective procedure. There has been minimal morbidity and no mortality. Follow-up from 1 to 11 years shows no recurrence of stenosis. There has been normal laryngeal and airway growth.

Cerebral specialization in young adults with Down syndrome

Adults with and without Down syndrome performed a rapid unimanual finger-tapping task alone and while sound-shadowing high frequency words. For male subjects, the concurrent speech disrupted right-hand, but not left-hand performance. Females suffered finger-tapping decrements in both hands in the dual-task situation. These results provide no evidence for reverse (right hemisphere) lateralization of speech in individuals with Down syndrome.

Portal vein ultrasonography in the early diagnosis of necrotizing enterocolitis

The nonoperative diagnosis of necrotizing enterocolitis (NEC) is dependent upon the radiographic finding of pneumatosis intestinalis. A significant number of neonates develop clinical signs compatible with NEC but nondiagnostic radiographs. This can result in delayed, inappropriate, or unnecessary therapy. This paper presents experience with portal vein (PV) ultrasonography in the diagnosis of NEC. Since January 1984, 15 newborns with suspected NEC have undergone PV ultrasonography (mean gestation 33 weeks, mean weight 1,705 g). Each had developed abdominal distention with evidence of sepsis. Stool was positive for occult blood in 11. Abdominal radiographs were interpreted as abnormal but nonspecific in 10 neonates, definite pneumatosis in 3, and normal in 2. No infant had portal vein air on plain abdominal radiograph. Occult PV air was detected by ultrasonography in five infants. These included all infants with obvious pneumatosis, a newborn with a nonspecific radiograph and a neonate with a "normal" x-ray. Of the ten infants without PV air on ultrasound, clinical symptoms resolved without specific therapy in seven. Two infants were proven to have nonenteric sepsis, and the remaining newborn developed intestinal necrosis secondary to aortic thrombus. In the five infants with occult PV air on ultrasound, two subsequently required intestinal resection. The remaining three were treated medically for ten days without sequelae. PV ultrasonography has proven to be a helpful adjunct in the early diagnosis of NEC. This diagnostic maneuver, when applied appropriately, may enable early therapy of the infant with NEC and avoid inappropriate or unnecessary therapy in the suspected case.

Sex differences in dual-task interference between speaking and a manual force-production task

12 male and 12 female right-handed adults performed a unimanual force-production task alone and while sound-shadowing high frequency words. The secondary speech task disrupted right-hand performance by men and left-hand performance by women. The implications of these findings for intrahemisphere-interference models of dual-task performance are discussed.

Tuberculosis of the orbit

Two cases of orbital tuberculosis in white Canadians are reported. The two patients did not suffer from pulmonary tuberculosis, the orbital disease was associated with tuberculosis sinusitis in the first case and blood-borne from constrictive tuberculous pericarditis in the second case. Acid-fast bacilli are difficult to detect in the pathological specimens and the diagnosis is usually based on the following: (1) the positive tuberculin skin test; (2) the caseating granulomatous inflammatory lesion on histopathology, which is highly suggestive of active tuberculosis; (3) the positive culture for Mycobacterium tuberculosis if the specimens are obtained early in the course of the disease; and (4) the complete resolution of the disease with the specific antituberculous medications.

Microtubules in immature oocytes of Xenopus laevis

Previous work indicated that immature oocytes of Xenopus were incapable of assembling microtubules but that competence was achieved during maturation. We report here that small numbers of microtubules do exist in immature oocytes. Consistent with this finding, ultrastructural observations indicate that brain microtubules injected into immature oocytes persist in large numbers for at least 30 min. We report that the tubulin dimers of mature and immature oocytes are equally capable of assembling with brain tubulin in vitro. We confirmed previous results that injection of taxol into immature oocytes has no effect when assayed by light microscopy. However, ultrastructural observations suggest that some microtubule assembly is stimulated by taxol. We tested for the ability of immature oocytes to elongate microtubules from ‘seeds’ by injecting deciliated pellicles of Tetrahymena. No elongation was observed either by light or electron microscopic observation. We conclude that the immature oocyte is capable of very limited microtubule assembly and that a marked increase in assembly competence occurs during maturation. Our data suggest that the change in assembly competence during maturation is due to the release, activation or synthesis of a stimulatory co-factor.

Spatial organization of axonal microtubules

Several workers have found that axonal microtubules have a uniform polarity orientation. It is the "+" end of the polymer that is distal to the cell body. The experiments reported here investigate whether this high degree of organization can be accounted for on the basis of structures or mechanisms within the axon. Substantial depolymerization of axonal microtubules was observed in isolated, postganglionic sympathetic nerve fibers of the cat subjected to cold treatment; generally less than 10% of the original number of microtubules/micron 2 remained in cross section. The number of cold stable MTs that remained was not correlated with axonal area and they were also found within Schwann cells. Microtubules were allowed to repolymerize and the polarity orientation of the reassembled microtubules was determined. In fibers from four cats, a majority of reassembled microtubules returned with the original polarity orientation. However, in no case was the polarity orientation as uniform as the original organization. The degree to which the original orientation returned in a fiber was correlated with the number of cold-stable microtubules in the fiber. We suggest that stable microtubule fragments serve as nucleating elements for microtubule assembly and play a role in the spatial organization of neuronal microtubules. The extremely rapid reassembly of microtubules that we observed, returning to near control levels within the first 5 min, supports microtubule elongation from a nucleus. However, in three of four fibers examined this initial assembly was followed by an equally rapid, but transient decline in microtubule number to a value that was significantly different than the initial peak. This observation is difficult to interpret; however, a similar transient peak has been reported upon repolymerization of spindle microtubules after pressure induced depolymerization.