Multi-scale analysis of the surface layer urban heat island effect in five higher density precincts of central Sydney

The urban heat island (UHI) effect is invariably present in cities, mainly due to increased urbanisation. It can result in higher urban densities being significantly hotter (frequently more than 4°C, even up to 10°C) than their peri-urban surroundings. Urban structure and land cover are key contributors to the surface layer urban heat island (sUHI) effect at city and district scale. This research aims to explore which urban configurations can make urban precincts and their microclimates more resilient to the dangerous sUHI effect. In the context of the city of Sydney, Australia, the research aims to explore the most heat resilient urban features for neighbourhoods, at precinct scale. The investigation examines five high density precincts in central Sydney. The analysis of these precincts is based on remote sensing thermal data of two independent sources: a nocturnal remote-sensing thermal image of central Sydney on 6 February 2009 and a diurnal Landsat 7– ETM+ data from 2008-2009. Comparing the surface temperature of streetscape and buildings’ rooftop feature layers indicates that open spaces are the urban elements most sensitive to the sUHI effect. Therefore, the correlations between street network intensity, open public space ratio, and urban greenery plot ratio and sUHI effect are being analysed in the five high density precincts selected. Results indicate that a higher open space ratio and street network intensity have a significant correlation to a higher sUHI effect at precinct scale. However, higher urban greenery plot ratios could mitigate the sUHI effect in these precincts. In addition, annual variation of land use features of streetscape, building (rooftop), open space and urban greenery are being analysed based on diurnal Landsat 7– ETM+ data for 2008-2009. Results indicate that an increase in urban greenery is the most effective strategy for land surface that is more resilient to the sUHI, while open public space is up to 15 per cent less heat resilient. The research outcomes support the importance of increasing urban greenery, particularly in open public spaces, to achieve cooler cities.Ehsan Sharifi, Conrad Philipp and Steffen Lehman

Resilience to heat in public space: a case study of Adelaide, South Australia

During summer heatwaves, heat load exacerbates in urban heat islands (especially in hot climates) and threatens public life in cities. This paper examines the links between urban microclimates, outdoor thermal discomfort and public life through an exploratory case study. Heat resilience is highlighted as the ability of the space to support its normal activities when experiencing out-of-comfort temperatures. It also reports on the correlations between heat sensitive outdoor activities and urban greenery in three disparate case studies in Adelaide. Results indicate that necessary and optional activities start to decline after the apparent temperature reaches the threshold of 28 °C–32 °C, while activities in public spaces with more urban greenery show higher resilience to heat stress. Research findings propose heat resilience as a quality indicator in public space and support the application of urban greenery to make urban settings more resilient to heat stress.Ehsan Sharifi, Alpana Sivam and John Bolan

Reduced Phagocytic Capacity of Blood Monocyte/Macrophages in Tuberculosis Patients Is Further Reduced by Smoking.

Tuberculosis (TB) and tobacco use are two major alarming global health issues posing immense threats to human populations. Mycobacterium tuberculosis (MTB) by activation of macrophages could induce the sequences of cells activation and releases of inflammatory cytokines such as CXCL-8, Il-12 and TNF-α which in turn induces the immune system network. However no information is available on other activity of cells by MTB and smoking. In the current study we aimed to investigate the serum levels TNF-a, CXCL-8 and phagocytosis capacity in tuberculosis patients with and without smoking. 103 subjects entered the study including 61 new diagnosed pulmonary TB patients (23 smokers and 38 nonsmokers) and 42 control healthy subjects. The phagocytosis of fluorescein isothiocyanate dextran (FITC-dextran) in blood monocytes/macrophages through flowcytometry was assessed. Serum levels of TNF-a and CXCL-8 were analyzed by ELISA methods. A lower percentage of cells from TB patients who smoked [50.29% (43.4-57.2), p<0.01] took up FITC-dextran after 2h compared to non-smoking TB subjects [71.62% (69.2-74.1)] and healthy cases [97.45% (95.9-99.1). Phagocytic capacity was inversely correlated with cigarette smoking as measured by pack years (r=-0.73, p<0.001). The serum levels of TNF-a and CXCL-8 were significantly higher in the TB patients who smoked compared to the TB non-smoker group (p<0.001, p<0.01 respectively). Blood monocytes/macrophages from TB patients have reduced phagocytic capacity which is further reduced in TB patients who smoke. Smoking enhanced serum levels of TNF-a and CXCL-8 suggesting a greater imbalance between the proinflammatory and anti-inflammatory factors in these patients

Drug-delivery Ca-Mg Silicate Scaffolds Encapsulated in PLGA

The aim of this work is to develop dual-functional scaffolds for bone tissue regeneration and local antibiotic delivery applications. In this respect, bioresorbable bredigite (Ca7MgSi4O16) porous scaffolds were fabricated by a foam replica method, loaded with vancomycin hydrochloride and encapsulated in poly lactic-co-glycolic acid (PLGA) coatings. Field emission scanning electron microscopy, Archimedes porosimetry and Fourier-transform infrared spectroscopy were used to characterize the structure of the scaffolds. The drug delivery kinetics and cytocompatibility of the prepared scaffolds were also studied in vitro. The bare sample exhibited a burst release of vancomycin and low biocompatibility with respect to dental pulp stem cells based on the MTT assay due to the fast bioresorption of bredigite. While keeping the desirable characteristics of pores for tissue engineering, the biodegradable PLGA coatings modified the drug release kinetics, buffered physiological pH and hence improved the cell viability of the vancomycin-loaded scaffolds considerably

Landsat surface temperature data analysis for urban heat resilience: case study of Adelaide

Meeting: CUPUM 2017: 15th International Conference on Computers in Urban Planning and Urban Management (11-14 July 2017 Adelaide, Australia )Smarter urban futures require resilient built environment in the context of climate change. This chapter demonstrates the application of satellite-based surface cover and temperature data to support planning for urban heat resilience. Landsat 7 ETM+ and Landsat 8 data is used to analyse the correlation of urban surface covers to the urban heat island effect in Adelaide. Methods for data source selection, surface cover classification, surface temperature calculation and analysis are detailed in this chapter. Results indicate that tree canopy and surface water covers had the least surface temperature variations in mesoscale. The average minimum surface temperature of tree canopy cover was 2.79 °C lower than asphalt and 4.74 °C lower than paved areas. Freely available satellite urban surface temperature data can assist urban planning authorities in planning heat resilient urban spaces for smarter urban futures in the context of climate change.Ehsan Sharifi, Alpana Sivam, Sadasivam Karuppannan and John W Bolan

Structure, Wettability, Corrosion and Biocompatibility of Nitinol Treated by Alkaline Hydrothermal and Hydrophobic Functionalization for Cardiovascular Applications

The main objective of this study is to hydrophobize nitinol (Ni-Ti alloy) for cardiovascular applications. For this purpose, medical nitinol samples were subjected to sodium hydroxide hydrothermal treatments at various temperatures, followed by hexadecyltrimethoxysilane (HDTMS) functionalization. Then, the structure, wettability, corrosion, cytocompatibility and cell adhesion of the prepared samples were evaluated. According to the results, porous blade-shaped layers of sodium titanate were formed on the substrate surface as a result of the alkaline treatment. These nano-rough features offered considerable hydrophobicity after HDTMS processing, where a maximum water contact angle of about 140° was obtained for the sample treated at 120 °C, followed by the HDTMS coating. In contrast to the individual application of the alkaline treatments, the subsequent HDTMS processing improved corrosion resistance in the simulated body fluid. Although all the samples presented appropriate cytocompatibility with respect to human umbilical vein endothelial cells, the cells did not show an adhesion tendency to the hydrophobic surfaces. It is concluded that alkaline hydrothermal and HDTMS processed nitinol can be considered for cardiovascular applications demanding hydrophobic surfaces

Impact of Ground Water Depletion on the Mesquite Community at Edwards Air Force Base, Western Mojave Desert, California

Edwards Air Force Base (EAFB) provides a habitat refugium for mesquite woodlands in the western Mojave Desert of the Antelope Valley. Although many mesquite communities in the arid southwest are considered invasive as they reduce the extent of grazing lands, the community at EAFB is composed primarily of large, widely spaced trees that provide food and shelter for local wildlife species and recreational opportunities for base personnel. Unfortunately, the range of these mesquite trees appears to be contracting as mature and old individuals dominate the community. Although anecdotal evidence suggests that the fall in the local groundwater table is responsible for the decline of the mesquite community at EAFB, no research has been carried out to confirm this. Our results corroborate the hypothesis that the groundwater table at EAFB has declined in the second half of the 20th century and that the area of the mesquite community is diminishing. Although the mesquite community expanded vigorously from 1956 to 1968, it contracted considerably from 1984 to 2000. The evidence for this observed decline is reinforced by the results of the age-class analysis as the community in 2003 is made up largely of mature, old, dying and dead trees. Few saplings (older than 2 years) and no new seedlings (1–2 years) are present in the study sites, suggesting that the mesquite community may not be able to replenish itself

Improved gravity anomaly fields from retracked multimission satellite radar altimetry observations over the Persian Gulf and the Caspian Sea

Satellite radar altimetry observations are used to derive short wavelength gravity anomaly fields over the Persian Gulf and the Caspian Sea, where in situ and ship-borne gravity measurements have limited spatial coverage. In this study the retracking algorithm ‘Extrema Retracking’ (ExtR) was employed to improve sea surface height (SSH) measurements that are highly biased in the study regions due to land contaminations in the footprints of the satellite altimetry observations. ExtR was applied to the waveforms sampled by the five satellite radar altimetry missions: TOPEX/POSEIDON, JASON-1, JASON-2, GFO and ERS-1. Along-track slopes have been estimated from the improved SSH measurements and used in an iterative process to estimate deflections of the vertical, and subsequently, the desired gravity anomalies. The main steps of the gravity anomaly computations involve estimating improved SSH using the ExtR technique, computing deflections of the vertical from interpolated SSHs on a regular grid using a biharmonic spline interpolation and finally estimating gridded gravity anomalies. A remove–compute–restore algorithm, based on the fast Fourier transform, has been applied to convert deflections of the vertical into gravity anomalies. Finally, spline interpolation has been used to estimate regular gravity anomaly grids over the two study regions.Results were evaluated by comparing the estimated altimetry-derived gravity anomalies (with and without implementing the ExtR algorithm) with ship-borne free air gravity anomaly observations, and free air gravity anomalies from the Earth Gravitational Model 2008 (EGM2008). The comparison indicates a range of 3–5 mGal in the residuals, which were computed by taking the differences between the retracked altimetry-derived gravity anomaly and the ship-borne data. The comparison of retracked data with ship-borne data indicates a range in the root-mean-square-error (RMSE) between approximately 1.8 and 4.4 mGal and a bias between 0.4062 and 2.1413 mGal over different areas. Also a maximum RMSE of 4.4069 mGal, with a mean value of 0.7615 mGal was obtained in the residuals. An average improvement of 5.2746 mGal in the RMSE of the altimetry-derived gravity anomalies corresponding to 89.9 per cent was obtained after applying the ExtR post-processing

Visualizations of Travel Time Performance based on Vehicle Re-identification Data

This paper provides a visual reference of the breadth of arterial performance phenomena based on travel time measures obtained from reidentification technology that has proliferated in the past 5 years. These graphical performance measures are revealed through overlay charts and statistical distribution as revealed through cumulative frequency diagrams (CFDs). With overlays of vehicle travel times from multiple days, dominant traffic patterns over a 24-h period are reinforced and reveal the traffic behavior induced primarily by the operation of traffic control at signalized intersections. A cumulative distribution function in the statistical literature provides a method for comparing traffic patterns from various time frames or locations in a compact visual format that provides intuitive feedback on arterial performance. The CFD may be accumulated hourly, by peak periods, or by time periods specific to signal timing plans that are in effect. Combined, overlay charts and CFDs provide visual tools with which to assess the quality and consistency of traffic movement for various periods throughout the day efficiently, without sacrificing detail, which is a typical byproduct of numeric-based performance measures. These methods are particularly effective for comparing before-and-after median travel times, as well as changes in interquartile range, to assess travel time reliability

A case study of sustainable urban planning principles in Curitiba (Brazil) and their applicability in Shiraz (Iran)

This paper investigates sustainability principles in the city of Curitiba, in Brazil, as a pioneer which has commenced its sustainability journey since the 1960s. Analyzing sustainability principles in Curitiba, the paper aims to study their applicability in the case of Shiraz in Iran. Considering the complexity of physical, social, cultural and environmental systems in urban planning, the research underlines the vitality of contextual studies, integration and implementation strategies in sustainability achievement in urban scale. It shows how and to what extent sustainability principles in a city can be adapted to other contexts. This comparative study benefits from interpretive methods of data collection and analysis based on primary and secondary resources. A theoretical framework of planning based on equity, economy and ecology is being utilized in data collection and analysis. The investigation indicates that Curitiba’s sustainability agenda is based on a set of integration and implementation strategies which combine decision making, education, transportation, public welfare, heritage conservation and waste management. It is argued that although every urban environment has its specific opportunities and constraints, still there are many things to learn from others.Ali Soltani, Ehsan Sharif