Due to the scarcity of air temperature (Ta) observations, urban heat studies often rely on satellite-derived Land Surface Temperature (LST) to characterise the near-surface thermal environment. ...However, there remains a lack of a quantitative understanding on how LST differs from Ta within urban areas and what are the controlling factors of their interaction. We use crowdsourced air temperature measurements in Sydney, Australia, combined with urban landscape data, Local Climate Zones (LCZ), high-resolution satellite imagery, and machine learning to explore the influence of urban form and fabric on the interaction between Ta and LST. Results show that LST and Ta have distinct spatiotemporal characteristics, and their relationship differs by season, ecological infrastructure, and building morphology. We found greater seasonal variability in LST compared to Ta, along with more pronounced intra-urban spatial variability in LST, particularly in warmer seasons. We also observed a greater temperature difference between LST and Ta in the built environment compared to the natural LCZs, especially during warm days. Natural LCZs (areas with mostly dense and scattered trees) showed stronger LST-Ta relationships compared to built areas. In particular, we observe that built areas with higher building density (where the heat vulnerability is likely more pronounced) show insignificant or negative relationships between LST- Ta in summer. Our results also indicate that surface cover, distance from the ocean, and seasonality significantly influence the distribution of hot and cold spots for LST and Ta. The spatial distribution for Ta hot spots does not always overlap with LST. We find that relying solely on LST as a direct proxy for the urban thermal environment is inappropriate, particularly in densely built-up areas and during warm seasons. These findings provide new perspectives on the relationship between surface and canopy temperatures and how these relate to urban form and fabric.
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•Urban form and seasonality modulate the relationship between LST and Ta.•Temperature difference between LST and Ta is greater in built LCZs compared to natural LCZs, especially during warm days.•Built LCZs that have less building density tend to show stronger LST-Ta relationships.•LST does not fully capture the seasonal and spatial variability in urban thermal environments.
To develop and apply an image acquisition and analysis strategy for spatial comparison of computed tomography (CT)-ventilation images with hyperpolarized gas magnetic resonance imaging (MRI).
Eleven ...lung cancer patients underwent xenon-129 (
Xe) and helium-3 (
He) ventilation MRI and coregistered proton (
H) anatomic MRI. Expiratory and inspiratory breath-hold CTs were used for deformable image registration and calculation of 3 CT-ventilation metrics: Hounsfield unit (CT
), Jacobian (CT
), and specific gas volume change (CT
). Inspiration CT and hyperpolarized gas ventilation MRI were registered via same-breath anatomic
H-MRI. Voxel-wise Spearman correlation coefficients were calculated between each CT-ventilation image and its corresponding
He-/
Xe-MRI, and for the mean values in regions of interest (ROIs) ranging from fine to coarse in-plane dimensions of 5 × 5, 10 × 10, 15 × 15, and 20 × 20, located within the lungs as defined by the same-breath
H-MRI lung mask. Correlation of
He and
Xe-MRI was also assessed.
Spatial correlation of CT-ventilation against
He/
Xe-MRI increased with ROI size. For example, for CT
, mean ± SD Spearman coefficients were 0.37 ± 0.19/0.33 ± 0.17 at the voxel-level and 0.52 ± 0.20/0.51 ± 0.18 for 20 × 20 ROIs, respectively. Correlations were stronger for CT
than for CT
or CT
. Correlation of
He with
Xe-MRI was consistently higher than either gas against CT-ventilation maps over all ROIs (P < .05). No significant differences were observed between CT-ventilation versus
He-MRI and CT-ventilation versus
Xe-MRI.
Comparison of ventilation-related measures from CT and registered hyperpolarized gas MRI is feasible at a voxel level using a dedicated acquisition and analysis protocol. Moderate correlation between CT-ventilation and MRI exists at a regional level. Correlation between MRI and CT is significantly less than that between
He and
Xe-MRI, suggesting that CT-ventilation surrogate measures may not be measuring lung ventilation alone.
In urban climate studies, datasets used to describe urban characteristics have traditionally taken a class-based approach, whereby urban areas are classified into a limited number of typologies with ...a resulting loss of fidelity. New datasets are becoming increasingly available that describe the three-dimensional structure of cities at sub-metre micro-scale resolutions, resolving individual buildings and trees across entire continents. These datasets can be used to accurately determine local characteristics without relying on classes, but their direct use in numerical weather and climate modelling has been limited by their availability, and because they require processing to conform to the required inputs of climate models. Here, we process building-resolving datasets across large geographical extents to derive city-descriptive parameters suitable as common model inputs at resolutions more appropriate for local or meso-scale modelling. These parameter values are then compared with the ranges obtained through the class-based Local Climate Zone framework. Results are presented for two case studies, Sydney and Melbourne, Australia, as open access data tables for integration into urban climate models, as well as codes for processing high-resolution and three-dimensional urban datasets. We also provide an open access 300 m resolution building morphology and surface cover dataset for the Sydney metropolitan region (approximately 5,000 square kilometres). The use of building resolving data to derive model inputs at the grid scale better captures the distinct heterogenetic characteristics of urban form and fabric compared with class-based approaches, leading to a more accurate representation of cities in climate models. As consistent building-resolving datasets become available over larger geographical extents, we expect bottom-up approaches to replace top-down class-based frameworks.
To investigate the effect of beam angles and field number on functionally-guided intensity modulated radiotherapy (IMRT) normal lung avoidance treatment plans that incorporate hyperpolarised helium-3 ...magnetic resonance imaging (
He MRI) ventilation data. Eight non-small cell lung cancer patients had pre-treatment
He MRI that was registered to inspiration breath-hold radiotherapy planning computed tomography. IMRT plans that minimised the volume of total lung receiving ⩾20 Gy (V
) were compared with plans that minimised
He MRI defined functional lung receiving ⩾20 Gy (fV
). Coplanar IMRT plans using 5-field manually optimised beam angles and 9-field equidistant plans were also evaluated. For each pair of plans, the Wilcoxon signed ranks test was used to compare fV
and the percentage of planning target volume (PTV) receiving 90% of the prescription dose (PTV
). Incorporation of
He MRI led to median reductions in fV
of 1.3% (range: 0.2-9.3%; p = 0.04) and 0.2% (range: 0 to 4.1%; p = 0.012) for 5- and 9-field arrangements, respectively. There was no clinically significant difference in target coverage. Functionally-guided IMRT plans incorporating hyperpolarised
He MRI information can reduce the dose received by ventilated lung without comprising PTV coverage. The effect was greater for optimised beam angles rather than uniformly spaced fields.
Mice harbouring gene mutations that cause phenotypic abnormalities during organogenesis are invaluable tools for linking gene function to normal development and human disorders. To generate mouse ...models harbouring novel alleles that are involved in organogenesis we conducted a phenotype-driven, genome-wide mutagenesis screen in mice using the mutagen N-ethyl-N-nitrosourea (ENU).
ENU was injected into male C57BL/6 mice and the mutations transmitted through the germ-line. ENU-induced mutations were bred to homozygosity and G3 embryos screened at embryonic day (E) 13.5 and E18.5 for abnormalities in limb and craniofacial structures, skin, blood, vasculature, lungs, gut, kidneys, ureters and gonads. From 52 pedigrees screened 15 were detected with anomalies in one or more of the structures/organs screened. Using single nucleotide polymorphism (SNP)-based linkage analysis in conjunction with candidate gene or next-generation sequencing (NGS) we identified novel recessive alleles for Fras1, Ift140 and Lig1.
In this study we have generated mouse models in which the anomalies closely mimic those seen in human disorders. The association between novel mutant alleles and phenotypes will lead to a better understanding of gene function in normal development and establish how their dysfunction causes human anomalies and disease.
Public health risks resulting from urban heat in cities are increasing due to rapid urbanisation and climate change, motivating closer attention to urban heat mitigation and adaptation strategies ...that enable climate-sensitive urban design and development. These strategies incorporate four key factors influencing heat stress in cities: the urban form (morphology of vegetated and built surfaces), urban fabric, urban function (including human activities), and background climate and regional geographic settings (e.g. topography and distance to water bodies). The first two factors can be modified and redesigned as urban heat mitigation strategies (e.g. changing the albedo of surfaces, replacing hard surfaces with pervious vegetated surfaces, or increasing canopy cover). Regional geographical settings of cities, on the other hand, cannot be modified and while human activities can be modified, it often requires holistic behavioural and policy modifications and the impacts of these can be difficult to quantify. When evaluating the effectiveness of urban heat mitigation strategies in observational or traditional modelling studies, it can be difficult to separate the impacts of modifications to the built and natural forms from the interactions of the geographic influences, limiting the universality of results. To address this, we introduce a new methodology to determine the influence of urban form and fabric on thermal comfort, by utilising a comprehensive combination of possible urban forms, an urban morphology data source, and micro-climate modelling. We perform 9814 simulations covering a wide range of realistic built and natural forms (building, roads, grass, and tree densities as well as building and tree heights) to determine their importance and influence on thermal environments in urban canyons without geographical influences. We show that higher daytime air temperatures and thermal comfort indices are strongly driven by increased street fractions, with maximum air temperatures increases of up to 10 and 15 °C as street fractions increase from 10% (very narrow street canyons and/or extensive vegetation cover) to 80 and 90% (wide street canyons). Up to 5 °C reductions in daytime air temperatures are seen with increasing grass and tree fractions from zero (fully urban) to complete (fully natural) coverage. Similar patterns are seen with the Universal Thermal Climate Index (UTCI), with increasing street fractions of 80% and 90% driving increases of 6 and 12 °C, respectively. We then apply the results at a city-wide scale, generating heat maps of several Australian cities showing the impacts of present day urban form and fabric. The resulting method allows mitigation strategies to be tested on modifiable urban form factors isolated from geography, topography, and local weather conditions, factors that cannot easily be modified.
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•A new methodology to determine the influence of urban form on thermal comfort.•Test cooling strategies on modifiable factors isolated from geographical settings.•Higher daytime temperatures are strongly driven by increased street fractions.•5 °C daytime air temperatures reductions as grass and tree fractions increase.
Inherited, complete deficiency of human HOIL-1, a component of the linear ubiquitination chain assembly complex (LUBAC), underlies autoinflammation, infections, and amylopectinosis. We report the ...clinical description and molecular analysis of a novel inherited disorder of the human LUBAC complex. A patient with multiorgan autoinflammation, combined immunodeficiency, subclinical amylopectinosis, and systemic lymphangiectasia, is homozygous for a mutation in HOIP, the gene encoding the catalytic component of LUBAC. The missense allele (L72P, in the PUB domain) is at least severely hypomorphic, as it impairs HOIP expression and destabilizes the whole LUBAC complex. Linear ubiquitination and NF-κB activation are impaired in the patient's fibroblasts stimulated by IL-1β or TNF. In contrast, the patient's monocytes respond to IL-1β more vigorously than control monocytes. However, the activation and differentiation of the patient's B cells are impaired in response to CD40 engagement. These cellular and clinical phenotypes largely overlap those of HOIL-1-deficient patients. Clinical differences between HOIL-1- and HOIP-mutated patients may result from differences between the mutations, the loci, or other factors. Our findings show that human HOIP is essential for the assembly and function of LUBAC and for various processes governing inflammation and immunity in both hematopoietic and nonhematopoietic cells.
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