| 1. |
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- 2019
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Tidskriftsartikel (refereegranskat)
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| 2. |
- Chen, Zhishan, et al.
(författare)
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Fine-mapping analysis including over 254 000 East Asian and European descendants identifies 136 putative colorectal cancer susceptibility genes
- 2024
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Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 15:1
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Tidskriftsartikel (refereegranskat)abstract
- Genome-wide association studies (GWAS) have identified more than 200 common genetic variants independently associated with colorectal cancer (CRC) risk, but the causal variants and target genes are mostly unknown. We sought to fine-map all known CRC risk loci using GWAS data from 100,204 cases and 154,587 controls of East Asian and European ancestry. Our stepwise conditional analyses revealed 238 independent association signals of CRC risk, each with a set of credible causal variants (CCVs), of which 28 signals had a single CCV. Our cis-eQTL/mQTL and colocalization analyses using colorectal tissue-specific transcriptome and methylome data separately from 1299 and 321 individuals, along with functional genomic investigation, uncovered 136 putative CRC susceptibility genes, including 56 genes not previously reported. Analyses of single-cell RNA-seq data from colorectal tissues revealed 17 putative CRC susceptibility genes with distinct expression patterns in specific cell types. Analyses of whole exome sequencing data provided additional support for several target genes identified in this study as CRC susceptibility genes. Enrichment analyses of the 136 genes uncover pathways not previously linked to CRC risk. Our study substantially expanded association signals for CRC and provided additional insight into the biological mechanisms underlying CRC development.
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| 3. |
- Chau, Pui Hing, et al.
(författare)
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Visits to the accident and emergency department in hot season of a city with subtropical climate: association with heat stress and related meteorological variables
- 2022
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Ingår i: International journal of biometeorology. - : Springer Nature. - 0020-7128 .- 1432-1254. ; 66:10, s. 1955-1971
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Tidskriftsartikel (refereegranskat)abstract
- Background Literature reporting the association between heat stress defined by universal thermal climate index (UTCI) and emergency department visits is mainly conducted in Europe. This study aimed to investigate the association between heat stress, as defined by the UTCI, and visits to the accident and emergency department (AED) in Hong Kong, which represents a subtropical climate region.Methods A retrospective study involving 13,438,846 AED visits in the public sector from May 2000 to September 2016, excluding 2003 and 2009, was conducted in Hong Kong. Age-sex-specific ANCOVA models of daily AED rates on heat stress and prolonged heat stress, adjusting for air quality, prolonged poor air quality, typhoon, rainstorm, year, day of the week, public holiday, summer vacation, and fee charging, were used.Results On a day with strong heat stress (32.1 °C ≤ UTCI ≤ 38.0 °C), the AED visit rate (per 100,000) increased by 0.9 (95% CI: 0.5, 1.3) and 1.7 (95% CI: 1.3, 2.1) for females and males aged 19–64 and 4.1 (95% CI: 2.7, 5.4) and 4.1 (95% CI: 2.6, 5.6) for females and males aged ≥ 65, while keeping other variables constant. On a day with very strong heat stress (38.1 °C ≤ UTCI ≤ 46.0 °C), the corresponding rates increased by 0.6 (95% CI: 0.1, 1.2), 2.2 (95% CI: 1.7, 2.7), 4.9 (95% CI: 3.1, 6.7), and 4.7 (95% CI: 2.7, 6.6), respectively. The effect size of heat stress associated with AED visit rates was negligible among those aged ≤ 18. Heat stress showed the greatest effect size for males aged 19–64 among all subgroups.Conclusion Biothermal condition from heat stress was associated with the health of the citizens in a city with a subtropical climate and reflected in the increase of daily AED visit. Public health recommendations have been made accordingly for the prevention of heat-related AED visits.
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| 4. |
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| 5. |
- Elsik, Christine G., et al.
(författare)
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The Genome Sequence of Taurine Cattle : A Window to Ruminant Biology and Evolution
- 2009
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 324:5926, s. 522-528
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Tidskriftsartikel (refereegranskat)abstract
- To understand the biology and evolution of ruminants, the cattle genome was sequenced to about sevenfold coverage. The cattle genome contains a minimum of 22,000 genes, with a core set of 14,345 orthologs shared among seven mammalian species of which 1217 are absent or undetected in noneutherian (marsupial or monotreme) genomes. Cattle-specific evolutionary breakpoint regions in chromosomes have a higher density of segmental duplications, enrichment of repetitive elements, and species-specific variations in genes associated with lactation and immune responsiveness. Genes involved in metabolism are generally highly conserved, although five metabolic genes are deleted or extensively diverged from their human orthologs. The cattle genome sequence thus provides a resource for understanding mammalian evolution and accelerating livestock genetic improvement for milk and meat production.
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| 6. |
- Fong, K. F., et al.
(författare)
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Residential building performance analysis at near extreme weather conditions in Hong Kong through a thermal-comfort-based strategy
- 2023
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Ingår i: Building Simulation. - : Springer Nature. - 1996-3599 .- 1996-8744. ; 16, s. 13-25
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Tidskriftsartikel (refereegranskat)abstract
- The precise building performance assessment of residential housings in subtropical regions is usually more difficult than that for the commercial premises due to the much more complicated behavior of the occupants with regard to the change in indoor temperature. The conventional use of a fixed schedule for window opening, clothing insulation and cooling equipment operation cannot reflect the real situation when the occupants respond to the change in thermal comfort, thus affecting the appropriateness of the assessment results. To rectify the situation, a new modeling strategy in which the modification of the various operation schedules was based on the calculated thermal comfort (TC), was developed in this study. With this new TC-based strategy, the realistic building performances under different cooling provision scenarios applied to a high-rise residential building under the near extreme weather conditions were investigated and compared. It was found that sole provision of ventilation fans could not meet the zone thermal comfort by over 68% of the time, and air-conditioning was essential. The optimal use of ventilation fans for cooling could only help reduce the total cooling energy demand by less than 12% at best which could only be realistically evaluated by adopting the present strategy. Parametric studies were conducted which revealed that some design factors could offer opportunities for reducing the total cooling energy under the near extreme weather conditions.
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| 7. |
- Fresard, Laure, et al.
(författare)
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Identification of rare-disease genes using blood transcriptome sequencing and large control cohorts
- 2019
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Ingår i: Nature Medicine. - : NATURE PUBLISHING GROUP. - 1078-8956 .- 1546-170X. ; 25:6, s. 911-919
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Tidskriftsartikel (refereegranskat)abstract
- It is estimated that 350 million individuals worldwide suffer from rare diseases, which are predominantly caused by mutation in a single gene(1). The current molecular diagnostic rate is estimated at 50%, with whole-exome sequencing (WES) among the most successful approaches(2-5). For patients in whom WES is uninformative, RNA sequencing (RNA-seq) has shown diagnostic utility in specific tissues and diseases(6-8). This includes muscle biopsies from patients with undiagnosed rare muscle disorders(6,9), and cultured fibroblasts from patients with mitochondrial disorders(7). However, for many individuals, biopsies are not performed for clinical care, and tissues are difficult to access. We sought to assess the utility of RNA-seq from blood as a diagnostic tool for rare diseases of different pathophysiologies. We generated whole-blood RNA-seq from 94 individuals with undiagnosed rare diseases spanning 16 diverse disease categories. We developed a robust approach to compare data from these individuals with large sets of RNA-seq data for controls (n = 1,594 unrelated controls and n = 49 family members) and demonstrated the impacts of expression, splicing, gene and variant filtering strategies on disease gene identification. Across our cohort, we observed that RNA-seq yields a 7.5% diagnostic rate, and an additional 16.7% with improved candidate gene resolution.
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| 8. |
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| 9. |
- Hagger, Martin S., et al.
(författare)
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A Multilab Preregistered Replication of the Ego-Depletion Effect
- 2016
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Ingår i: Perspectives on Psychological Science. - : Sage Publications. - 1745-6916 .- 1745-6924. ; 11:4, s. 546-573
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Tidskriftsartikel (refereegranskat)abstract
- Good self-control has been linked to adaptive outcomes such as better health, cohesive personal relationships, success in the workplace and at school, and less susceptibility to crime and addictions. In contrast, self-control failure is linked to maladaptive outcomes. Understanding the mechanisms by which self-control predicts behavior may assist in promoting better regulation and outcomes. A popular approach to understanding self-control is the strength or resource depletion model. Self-control is conceptualized as a limited resource that becomes depleted after a period of exertion resulting in self-control failure. The model has typically been tested using a sequential-task experimental paradigm, in which people completing an initial self-control task have reduced self-control capacity and poorer performance on a subsequent task, a state known as ego depletion. Although a meta-analysis of ego-depletion experiments found a medium-sized effect, subsequent meta-analyses have questioned the size and existence of the effect and identified instances of possible bias. The analyses served as a catalyst for the current Registered Replication Report of the ego-depletion effect. Multiple laboratories (k = 23, total N = 2,141) conducted replications of a standardized ego-depletion protocol based on a sequential-task paradigm by Sripada et al. Meta-analysis of the studies revealed that the size of the ego-depletion effect was small with 95% confidence intervals (CIs) that encompassed zero (d = 0.04, 95% CI [-0.07, 0.15]. We discuss implications of the findings for the ego-depletion effect and the resource depletion model of self-control.
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| 10. |
- Ho, Hung Chak, et al.
(författare)
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“Planned greenspace” or “natural greenspace” in a high-density city with compact environment? An empirical study of osteoporosis among senior population
- 2022
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Ingår i: Building and Environment. - : Elsevier. - 0360-1323 .- 1873-684X. ; 219
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Tidskriftsartikel (refereegranskat)abstract
- Osteoporosis is a major physical health issue in healthy ageing among urban populations. However, few studies have investigated how greenspace can influence osteoporosis, especially to those who lived in a compact city with high-density living environment. Furthermore, no studies have investigated how “planned greenspace” and “natural greenspace” can separately influence osteoporosis among senior population. We hereby conducted an empirical study to evaluate the relationship between osteoporosis, “planned greenspace” and “natural greenspace”, based on the use of land use data derived from local geospatial information and satellite images. Our results showed that seniors who were 1) aged, 2) female, 3) less educated, 4) smokers, and 5) with chronic respiratory diseases were associated with osteoporosis. Considering factors of greenspace, a higher percentage of planned greenspace surrounding the residence may be a protective factor while natural greenspace did not influence the individuals. Specifically, a 10% increase of planned greenspace within the 600-m radius area surrounding the residence was negative associated with osteoporosis (−2.8% [-5.1%, −0.5%]). Based on our results, development of planned greenspace may be necessary, as compact built environment of a high-density city often resulted in a lack of planned greenspace for physical activities. Along with the World Health Organization (WHO) guidelines for an age-friendly city, our findings suggest that improving the planned greenspace in a walkable distance around one's neighboring environment is a potential strategy for prevention of osteoporosis and related physical health issues as well as for life quality improvement among the senior population.
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| 11. |
- Ho, Hung Chak, et al.
(författare)
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Systematic identification of heat events associated with emergency admissions to enhance the heat-health action plan in a subtropical city: a data-driven approach
- 2022
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Ingår i: Environmental Science and Pollution Research. - : Springer Nature. - 0944-1344 .- 1614-7499. ; 29:59, s. 89273-89282
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Tidskriftsartikel (refereegranskat)abstract
- According to the United Nations Office for Disaster Risk Reduction (UNDRR), a heat-health action plan should address various impacts of hazards at different levels, including an early warning system to monitor risks and behaviour enhancement to increase disaster preparedness. It is necessary to comply with guidelines regarding heat duration/intensity. In this study, we developed a data-driven approach to rapidly and systematically estimate the impacts of various heat events on emergency admissions among the adult population (n = 7,086,966) in Hong Kong in order to enhance the heat-health action plan. Immediate, short-term, and long-term impacts determined by 1-day, 4-day, and 8-day windows were estimated to identify specific heat events suitable for early warnings. In addition, underestimated risk, determined by a continuous increase in heat risk after days without significant emergency admissions, was estimated to evaluate potential maladaptive behaviours among a specific subpopulation. Based on age- and gender-specific analyses, 1D, 1D1N, and 2D2N were observed to have a stronger immediate impact on emergency admissions. 1D1N and 2D2N also showed notable short-term and long-term impacts. Based on heat vulnerability factors (age and gender), 2D2N was a higher-priority extreme heat event for early warning measures than 1D1N. Furthermore, men aged 19 to 64 had the highest underestimated risk. Specifically, they had IRR values of 1.113 [1.087, 1.140], 1.061 [1.035, 1.087], and 1.069 [1.043, 1.095] during lag days 3-5 of 3D2N, respectively, possibly due to a lack of adaptive behaviour. By adopting our approach, the duration of heat events with significant health impacts can be identified in order to further enhance relevant heat stress information. This framework can be applied to other cities with a similar background for rapid assessment.
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| 12. |
- Ho, Janice Y., et al.
(författare)
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Urban heat island effect-related mortality under extreme heat and non-extreme heat scenarios: A 2010–2019 case study in Hong Kong
- 2023
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Ingår i: Science of the Total Environment. - : Elsevier B.V.. - 0048-9697 .- 1879-1026. ; 858, Part 1
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Tidskriftsartikel (refereegranskat)abstract
- The urban heat island (UHI) effect exacerbates the adverse impact of heat on human health. However, while the UHI effect is further intensified during extreme heat events, prior studies have rarely mapped the UHI effect during extreme heat events to assess its direct temperature impact on mortality. This study examined the UHI effect during extreme heat and non-extreme heat scenarios and compared their temperature-mortality associations in Hong Kong from 2010 to 2019. Four urban heat island degree hour (UHIdh) scenarios were mapped onto Hong Kong's tertiary planning units and classified into three levels (Low, Moderate, and High). We assessed the association between temperature and non-external mortality of populations living in each UHIdh level for the extreme heat/non-extreme heat scenarios during the 2010–2019 hot seasons. Our results showed substantial differences between the temperature-mortality associations in the three levels under the UHIdh extreme heat scenario (UHIdh_EH). While there was no evidence of increased mortality in Low UHIdh_EH areas, the mortality risk in Moderate and High UHIdh_EH areas were significantly increased during periods of hot temperature, with the High UHIdh_EH areas displaying almost double the risk (RR: 1.08, 95%CI: 1.03, 1.14 vs. RR: 1.05, 95 % CI: 1.01, 1.09). However, other non-extreme heat UHI scenarios did not demonstrate as prominent of a difference. When stratified by age, the heat effects were found in Moderate and High UHIdh_EH among the elderly aged 75 and above. Our study found a difference in the temperature-mortality associations based on UHI intensity and potential heat vulnerability of populations during extreme heat events. Preventive measures should be taken to mitigate heat especially in urban areas with high UHI intensity during extreme heat events, with particular attention and support for those prone to heat vulnerability, such as the elderly and poorer populations.
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| 13. |
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| 14. |
- Jencson, Jacob E., et al.
(författare)
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Discovery of an Intermediate-luminosity Red Transient in M51 and Its Likely Dust-obscured, Infrared-variable Progenitor
- 2019
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Ingår i: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8205 .- 2041-8213. ; 880:2
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Tidskriftsartikel (refereegranskat)abstract
- We present the discovery of an optical transient (OT) in Messier. 51, designated M51 OT2019-1 (also ZTF 19aadyppr, AT 2019abn, ATLAS19bz1), by the Zwicky Transient Facility (ZTF). The OT rose over 15. days to an observed luminosity of M-r = -13 (nu L-nu = 9 x 10(6) L-circle dot), in the luminosity gap between novae and typical supernovae (SNe). Spectra during the outburst show a red continuum, Balmer emission with a velocity width of approximate to 400 km s(-1), Ca II and [Ca II] emission, and absorption features characteristic of an F-type supergiant. The spectra and multiband light curves are similar to the so-called SN impostors and intermediate-luminosity red transients (ILRTs). We directly identify the likely progenitor in archival Spitzer Space Telescope imaging with a 4.5 mu m luminosity of M-[4.5] approximate to -12.2 mag and a [3.6]-[4.5] color redder than 0.74 mag, similar to those of the prototype ILRTs SN 2008S and NGC 300 OT2008-1. Intensive monitoring of M51 with Spitzer further reveals evidence for variability of the progenitor candidate at [ 4.5] in the years before the OT. The progenitor is not detected in pre-outburst Hubble Space Telescope optical and near-IR images. The optical colors during outburst combined with spectroscopic temperature constraints imply a higher reddening of E(B - V) approximate to 0.7 mag and higher intrinsic luminosity of M-r approximate to -14.9 mag (nu L-nu = 5.3 x 10(7) L-circle dot) near peak than seen in previous ILRT candidates. Moreover, the extinction estimate is higher on the rise than on the plateau, suggestive of an extended phase of circumstellar dust destruction. These results, enabled by the early discovery of M51. OT2019-1 and extensive pre-outburst archival coverage, offer new clues about the debated origins of ILRTs and may challenge the hypothesis that they arise from the electron-capture induced collapse of extreme asymptotic giant branch stars.
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| 15. |
- Kwok, Yu Ting, et al.
(författare)
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To what extent can urban ventilation features cool a compact built-up environment during a prolonged heatwave? A mesoscale numerical modelling study for Hong Kong
- 2022
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Ingår i: Sustainable cities and society. - : Elsevier. - 2210-6707. ; 77
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Tidskriftsartikel (refereegranskat)abstract
- Recent advances in numerical tools and data for the study of urban microclimates have helped to evaluate countermeasures for urban heat in heterogeneous and high-rise cities such as Hong Kong. Thus, two ventilation strategy designs, point ('oases') and linear ('corridors') features, were numerically simulated during a typical heatwave using the multi-layer coupled MesoNH-SURFEX-TEB mesoscale atmospheric model.These strategies proved to be effective at night with respect to thermal comfort but caused a localised increase in heat stress during the day in the ventilated areas, which were less shaded. There was no significant deterioration in the wind performance around the developments that were redesigned to accommodate the displaced population due to the construction of the ventilation features; however, an improvement was observed in thermal comfort during the daytime. The simulated impacts were relatively localised, suggesting the importance of increasing porosity across the entire urban fabric. The corridors, especially when built along the axis of the prevailing winds, exhibited better ventilation at the pedestrian level than the oases. Nevertheless, the oases remain interesting features in the context of progressive urban ventilation planning that involve the implementation of isolated, connected, and eventually a network of features to provide benefits at the megalopolis scale.
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| 16. |
- Lai, Eric T. C., et al.
(författare)
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Perception of extreme hot weather and the corresponding adaptations among older adults and service providers–A qualitative study in Hong Kong
- 2023
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Ingår i: Frontiers in Public Health. - : Frontiers Media S.A.. - 2296-2565. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Background: Extreme hot weather events are happening with increasing frequency, intensity and duration in Hong Kong. Heat stress is related to higher risk of mortality and morbidity, with older adults being particularly vulnerable. It is not clear whether and how the older adults perceive the increasingly hot weather as a health threat, and whether community service providers are aware and prepared for such future climate scenario.Methods: We conducted semi-structure interviews with 46 older adults, 18 staff members of community service providers and two district councilors of Tai Po, a north-eastern residential district of Hong Kong. Transcribed data were analyzed using thematic analysis until data saturation was reached.Results: It was agreed upon among the older adult participants that the weather in recent years has become increasingly hot and this led to some health and social problems for them, although some participants perceived that hot weather did not have any impact in their daily lives and they were not vulnerable. The community service providers and district councilors reported that there is a lack of relevant services in the community to support the older adults in hot weather; and there is generally a lack of public education regarding the heat-health issue.Conclusions: Heatwaves are affecting older adults' health in Hong Kong. Yet, discussions and education effort regarding the heat-health issue in the public domain remain scarce. Multilateral efforts are urgently needed to co-create a heat action plan to improve community awareness and resilience.
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| 17. |
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| 18. |
- Lau, Kevin Ka-Lun, et al.
(författare)
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Investigating solar energy potential in tropical urban environment : A case study of Dar es Salaam, Tanzania
- 2017
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Ingår i: Sustainable Cities and Society. - : Elsevier BV. - 2210-6707. ; 30, s. 118-127
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Tidskriftsartikel (refereegranskat)abstract
- Solar energy is considered to be an alternative sustainable energy source in the urban environment. The potential of using solar energy in urban areas is highly dependent on urban morphology which affects the level of solar irradiance received by individual buildings. Many studies focus on solar energy potential of building form in urban areas but relatively few studies examine how urban morphology affects solar energy potential of urban neighbourhoods. It leads to inefficient design of neighbourhoods in terms of solar energy potential. The present study investigates the potential of exploiting solar energy in Dar es Salaam, Tanzania by using numerical modelling of solar irradiance on building roofs and façades. It is shown that there is substantial solar irradiance received by building roofs in all four study neighbourhoods and urban morphology has considerable effects on annual solar irradiance. Solar irradiance of different orientations of tilted roofs and façades is subject to seasonality of the solar azimuth angle. It is suggested that such abundant solar energy sources would provide solutions to accommodate the increasing energy demand and to improve living quality in urban areas due to the rapid urbanization of the city.
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| 19. |
- Lau, Kevin Ka-Lun, 1983, et al.
(författare)
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Street geometry design and its effect on mean radiant temperature: A parametric study based on numerical modelling
- 2015
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Ingår i: ICUC9 – 9 th International Conference on Urban Climate jointly with 12th Symposium on the Urban Environment. 20-24 July 2015, Toulouse, France.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The spatial variation of hotspots, in terms of their locations and magnitude, is examined in the present study, using the Solar and LongWave Environmental Irradiance Geometry (SOLWEIG) model. The effect of street geometry design parameters such as H/W ratios and street orientations on the radiant heat load are analyzed for three European cities with different regional climatic conditions. Various physical configurations of street trees are examined for their corresponding potential in mitigating the radiant heat load within urban structures. Findings suggest that a dense urban structure (H/W ratio ≥ 2) is capable of reducing radiant heat load at street level. High H/W ratios do not only reduce the magnitude of hotspots, but also changes their spatial distribution. The N-S canyons are found to be more favourable than the E-W canyons since they limit sun exposure to several hours at noon, despite of the diminishing difference between two orientations when H/W ratio increases. Diagonal streets reduce the magnitude of hotspots but increase the areas affected by moderately high mean radiant temperature (Tmrt). NE-SW orientated streets exhibits higher average hourly Tmrt during daytime since they are largely sun-exposed at the hottest time of the day. The highest mitigating effect of street trees is found when they are located in the sunlit areas. The reduction in average Tmrt decreases with increasing H/W ratios but considerable mitigating effect is still observed in the NE-SW orientations. It is also observed that larger tree crowns, even with higher spacing between individual trees, provide better shading than closely placed trees with smaller tree crowns. The present study provides information about the locations and magnitude of hotspots in different urban settings as well as the design of street trees as a mitigation measure to radiant heat load. It helps urban planners and designers to better design neighbourhoods in order to improve pedestrian thermal comfort within urban areas.
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| 20. |
- Lau, Kevin Ka-Lun, 1983, et al.
(författare)
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The effect of urban geometry on mean radiant temperature under future climate change: a study of three European cities
- 2015
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Ingår i: International journal of biometeorology. - : Springer Science and Business Media LLC. - 0020-7128 .- 1432-1254. ; 59:7, s. 799-814
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Tidskriftsartikel (refereegranskat)abstract
- Future anthropogenic climate change is likely to increase the air temperature (T a ) across Europe and increase the frequency, duration and magnitude of severe heat stress events. Heat stress events are generally associated with clear-sky conditions and high T a , which give rise to high radiant heat load, i.e. mean radiant temperature (T mrt ). In urban environments, T mrt is strongly influenced by urban geometry. The present study examines the effect of urban geometry on daytime heat stress in three European cities (Gothenburg in Sweden, Frankfurt in Germany and Porto in Portugal) under present and future climates, using T mrt as an indicator of heat stress. It is found that severe heat stress occurs in all three cities. Similar maximum daytime T mrt is found in open areas in all three cities despite of the latitudinal differences in average daytime T mrt . In contrast, dense urban structures like narrow street canyons are able to mitigate heat stress in the summer, without causing substantial changes in T mrt in the winter. Although the T mrt averages are similar for the north–south and east–west street canyons in each city, the number of hours when T mrt exceeds the threshold values of 55.5 and 59.4 °C—used as indicators of moderate and severe heat stress—in the north–south canyons is much higher than that in the east–west canyons. Using statistically downscaled data from a regional climate model, it is found that the study sites were generally warmer in the future scenario, especially Porto, which would further exacerbate heat stress in urban areas. However, a decrease in solar radiation in Gothenburg and Frankfurt reduces T mrt in the spring, while the reduction in T mrt is somewhat offset by increasing T a in other seasons. It suggests that changes in the T mrt under the future scenario are dominated by variations in T a . Nonetheless, the intra-urban differences remain relatively stable in the future. These findings suggest that dense urban structure can reduce daytime heat stress since it reduces the number of hours of high T mrt in the summer and does not cause substantial changes in average and minimum T mrt in the winter. In dense urban settings, a more diverse urban thermal environment is also preferred to compensate for reduced solar access in the winter. The extent to which the urban geometry can be optimized for the future climate is also influenced by local urban characteristics.
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| 21. |
- Lewis, Abigail S. L., et al.
(författare)
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Anoxia begets anoxia : A positive feedback to the deoxygenation of temperate lakes
- 2024
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Ingår i: Global Change Biology. - : John Wiley & Sons. - 1354-1013 .- 1365-2486. ; 30:1
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Tidskriftsartikel (refereegranskat)abstract
- Declining oxygen concentrations in the deep waters of lakes worldwide pose a pressing environmental and societal challenge. Existing theory suggests that low deep-water dissolved oxygen (DO) concentrations could trigger a positive feedback through which anoxia (i.e., very low DO) during a given summer begets increasingly severe occurrences of anoxia in following summers. Specifically, anoxic conditions can promote nutrient release from sediments, thereby stimulating phytoplankton growth, and subsequent phytoplankton decomposition can fuel heterotrophic respiration, resulting in increased spatial extent and duration of anoxia. However, while the individual relationships in this feedback are well established, to our knowledge, there has not been a systematic analysis within or across lakes that simultaneously demonstrates all of the mechanisms necessary to produce a positive feedback that reinforces anoxia. Here, we compiled data from 656 widespread temperate lakes and reservoirs to analyze the proposed anoxia begets anoxia feedback. Lakes in the dataset span a broad range of surface area (1–126,909 ha), maximum depth (6–370 m), and morphometry, with a median time-series duration of 30 years at each lake. Using linear mixed models, we found support for each of the positive feedback relationships between anoxia, phosphorus concentrations, chlorophyll a concentrations, and oxygen demand across the 656-lake dataset. Likewise, we found further support for these relationships by analyzing time-series data from individual lakes. Our results indicate that the strength of these feedback relationships may vary with lake-specific characteristics: For example, we found that surface phosphorus concentrations were more positively associated with chlorophyll a in high-phosphorus lakes, and oxygen demand had a stronger influence on the extent of anoxia in deep lakes. Taken together, these results support the existence of a positive feedback that could magnify the effects of climate change and other anthropogenic pressures driving the development of anoxia in lakes around the world.
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| 22. |
- Lindberg, Fredrik, 1974, et al.
(författare)
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The impact of urban planning strategies on heat stress in a climate-change perspective
- 2016
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Ingår i: Sustainable Cities and Society. - : Elsevier BV. - 2210-6707. ; 25, s. 1-12
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Tidskriftsartikel (refereegranskat)abstract
- Spatial and temporal characteristics of outdoor heat stress for a redevelopment area in Gothenburg, Sweden, in a climate change perspective, using mean radiant temperature (Tmrt) as a proxy for heat stress are presented. The impact of climate change on Tmrt was evaluated using statistically downscaled data from a regional climate model. The simulated average Tmrt for the future scenarios was not higher than for today’s climate, because the increased longwave radiation fluxes caused by higher temperatures were offset by reduced shortwave radiation fluxes caused by increased cloudiness. The spatial pattern of Tmrt in the study area during warm and clear weather is primarily governed by the shadow patterns of buildings and vegetation. The highest average-daytime Tmrt was found at open locations, but because open areas also have the highest frequency of sunlit occasions, this does not necessarily imply that open areas are most prone to heat-stress. When considering only occasions during clear and warm weather situations, the highest Tmrt were usually found close to sun-exposed, south-facing walls. Under these criteria, denser urban environments have lower heat stress than more open urban environments. The warmest areas were also found to be the warmest areas in the future as well. Tree-shadows are an effective measure to reduce daytime Tmrt. Trees was found to have the largest impact on Tmrt in open areas where vegetation is sparse, especially when the distance to the nearest “cool” place is used as a measure of heat-stress.
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| 23. |
- Liu, Zhixin, et al.
(författare)
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Microclimatic measurements in tropical cities: Systematic review and proposed guidelines
- 2022
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Ingår i: Building and Environment. - : Elsevier. - 0360-1323 .- 1873-684X. ; 222
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Forskningsöversikt (refereegranskat)abstract
- To tackle urban overheating induced by the combined effect of global warming and intensive urbanization, researchers have recommended assimilating microclimate-related strategies into urban design practices. Field measurements, playing a central role in urban climatology, have been widely applied worldwide. Reviewing the last five years' field measurement studies and existing guidelines and standards from WMO (World Meteorological Organization) and ISO (International Organization for Standardization), this study identified a gap between available guidelines and researchers' practical needs to ascertain the collection of high caliber data. Therefore, dedicated guidelines are required to explain the crucial conceptual and application issues and refine systematic field measurement methods. This demand is particularly acute for microscale and urban environments. This study proposed and explained integrated and comprehensive guidelines for systematic microclimate field measurements. The suggested workflow included four main steps: formulating field measurement plan, preparing for field measurements, sustaining measurement quality, and curating data. The complex and heterogeneous environment in urban areas was carefully evaluated to hone the data acquisition campaign and ascertain data quality. Relevant concepts and practices learned from existing guidelines and standards, experiences from actual field studies, and professional recommendations were distilled and incorporated into the guidelines. The significance of a complete report with full metadata was emphasized. Detailed hints, precautions, recommendations, examples, and a metadata checklist were provided as a helpful and actionable package of research procedures.
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| 24. |
- Milošević, Dragan, et al.
(författare)
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Mask wearing behavior in hot urban spaces of Novi Sad during the COVID-19 pandemic
- 2022
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 815
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Tidskriftsartikel (refereegranskat)abstract
- Urban overheating (due to climate change and urbanization) and COVID-19 are two converging crises that must be addressed in tandem. Fine-scale, place-based, people-centric biometeorological and behavioral data are needed to implement context-specific preventative measures such as mask-wearing. This study collected local biometeorological measurements in diverse urban spaces (square, urban park, river quay) in Novi Sad, Serbia on hot sunny summer days (27–30 August 2020) during the COVID-19 pandemic. Observations were supplemented by an online survey asking questions about thermal sensation, comfort, and concurrent protective behavior of the local population. Biometeorological measurements show that the main square in the city center was the most thermally uncomfortable area. According to the survey, it was also perceived as the least safe space to not contract the virus. The urban park was perceived as the most thermally comfortable area in the morning and during midday. It was also considered the safest urban space for outdoor activities. In the evening, the river quay was the most thermally comfortable area in the city. Intra-urban differences in Physiologically Equivalent Temperatures were highest during midday, while differences in air temperatures were highest in the evening. More than 70% of the respondents did not wear face masks when it was hot because of breathing issues and feeling warmer than without mask. Most people wearing a mask felt “slightly warm” in the morning and evening, while the majority of respondents felt “hot” during midday. Only 3% of the respondents felt comfortable while wearing a mask, while 97% experienced some degree of discomfort (from slight discomfort to very uncomfortable). Our study shows that fine scale temporal and spatial urban biometeorological data and population surveys should be included in decision-making processes during the pandemic to develop climate-sensitive health services that are place-based, people-centric, and facilitate planning towards green, resilient, and inclusive cities.
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| 25. |
- Ouyang, Wanlu, et al.
(författare)
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Comparing different recalibrated methods for estimating mean radiant temperature in outdoor environment
- 2022
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Ingår i: Building and Environment. - : Elsevier. - 0360-1323 .- 1873-684X. ; 216
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Tidskriftsartikel (refereegranskat)abstract
- Mean radiant temperature (MRT) is a significant variable for outdoor thermal comfort studies. Two measurement-based methods can estimate MRT, one is globe thermometer – cheap, easily-applied but relatively inaccurate, another is integral radiation measurement method (also known as the six-directional method) - accurate but expensive. Due to low-cost and convenience, the globe thermometer has been widely used. Previous studies have improved its estimation accuracy by recalibrating the convection coefficients in the ISO method. Thus, it is pending to cross-compare the performance of these recalibrated methods.This study aims to investigate the transferability of the recalibrated methods for estimating MRT in outdoor environment. First, field measurement was conducted in a subtropical city, Hong Kong. MRT was obtained through two methods: globe thermometer and integral radiation method. Second, the existing recalibrated convection coefficients were summarized, and the localized convection coefficient was recalibrated. Third, all recalibrated methods were compared for their performance. The impacts of measurement locations, devices, analysis time intervals were examined.The results showed that the newly recalibrated method achieved the lowest estimation errors (RMSE = 3.84 °C). Other recalibrated methods presented higher RMSE (3.84–17.52 °C), similar as conventional ISO method (7.91 °C). Especially for open spaces, the coefficients from other cities should be cautiously applied when the accuracy requirement is less than ±2 °C. Kestrel and Grey globe are more recommended in subtropical cities. This study shed light on the application of globe thermometer for outdoor environment, and emphasized the necessity in recalibrating the convection coefficients locally.
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| 26. |
- Savvides, Andreas, et al.
(författare)
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Examining user thermal comfort in spaces between buildings: Exploring parametric solutions for BIPVs for Luleå, Sweden, and Limassol, Cyprus
- 2024
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Ingår i: Energy Reports. - : Elsevier Ltd. - 2352-4847. ; 11, s. 5235-5251
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Tidskriftsartikel (refereegranskat)abstract
- The global concern over the interplay between climate mitigation, urban structures, and city energy usage underscores a pressing need for innovative solutions. This research delves into the relationship between urban layouts, energy dynamics, and the thermal comfort of public spaces between buildings. Focusing on the contrasting climates of Luleå, Sweden, and Limassol, Cyprus, the study employs ENVI-met, a microscale urban climate simulation tool, for a parametric exploration at the city block scale. Assessing eight distinct scenarios across morning, noon, and afternoon timeframes, the research considers the impact of Building-Integrated Photovoltaics (BIPVs) on user thermal comfort. Contrary to expectations, the study reveals that BIPV integration alone may not be the primary driver of improved thermal comfort during peak heat periods. Instead, factors like urban density and urban morphology emerge as influential contributors. For instance, increasing the urban fabric density by doubling the building height resulted in greater PET fluctuations ranging from −3 to +3 degrees, compared to the modest PET fluctuations ranging from 0 to +3 degrees observed with the simple integration of PVs onto buildings. These findings offer valuable insights for urban planners and policymakers, guiding decisions in considering the issue of thermal comfort in public spaces between buildings, while optimizing energy consumption in urban areas.
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| 27. |
- Spett, Max, et al.
(författare)
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Urban Microclimate Impact on Vertical Building-Integrated Photovoltaic Panels
- 2024
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Ingår i: Urban Planning. - 2183-7635. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- The ongoing climate crisis and turbulence on the world stage has highlighted the need for sustainability and resilience in the development and maintenance of urban areas regarding climate comfort and energy access. Local production of green energy increases both the sustainability and resilience of an area. Traditionally, photovoltaic (PV) panels are deployed wherever the amount of sunlight is highest but lowering costs for PV panels makes them cost-effective even in colder climates. Within the broader umbrella of positive energy districts, façade mounted building-integrated PV panels in urban areas additionally present unique opportunities and challenges, as factors such as wind, solar irradiance, or nearby obstructions can have either a positive or negative effect on the performance of the PV panels. In this article, we aimed to answer the question: What factors inform the optimization of vertical PV panels? To answer this, we developed a method for the optimization of placement of PV panels. By building upon readily available weather data, local panel conditions were examined, and field-driven aggregation algorithm used to guide panel placement. Performance of the resulting panel configurations were then compared to a baseline case. Results indicate that our developed method helped mitigate negative impacts of the aforementioned factors, and often improved performance over baseline.
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| 28. |
- Thorsson, Sofia, 1972, et al.
(författare)
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Present and projected future mean radiant temperature for three European cities
- 2017
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Ingår i: International Journal of Biometeorology. - : Springer Science and Business Media LLC. - 0020-7128 .- 1432-1254. ; 61:9, s. 1531-1543
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Tidskriftsartikel (refereegranskat)abstract
- © 2017 The Author(s)Present-day and projected future changes in mean radiant temperature, Tmrt in one northern, one mid-, and one southern European city (represented by Gothenburg, Frankfurt, and Porto), are presented, and the concept of hot spots is adopted. Air temperature, Ta, increased in all cities by 2100, but changes in solar radiation due to changes in cloudiness counterbalanced or exacerbated the effects on Tmrt. The number of days with high Tmrt in Gothenburg was relatively unchanged at the end of the century (+1 day), whereas it more than doubled in Frankfurt and tripled in Porto. The use of street trees to reduce daytime radiant heat load was analyzed using hot spots to identify where trees could be most beneficial. Hot spots, although varying in intensity and frequency, were generally confined to near sunlit southeast-southwest facing walls, in northeast corner of courtyards, and in open spaces in all three cities. By adding trees in these spaces, the radiant heat load can be reduced, especially in spaces with no or few trees. A set of design principles for reducing the radiant heat load is outlined based on these findings and existing literature.
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| 29. |
- Vassiliades, C., et al.
(författare)
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A climate sensitive design approach to BIPV : Investigating the nexus between solar energy and thermal comfort in cities in Sweden and Cyprus
- 2023
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Ingår i: Building and Environment. - : Elsevier. - 0360-1323 .- 1873-684X. ; 243
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Tidskriftsartikel (refereegranskat)abstract
- The research performed attempts to answer the question of how building integration of active solar systems may affect the thermal comfort in open areas and the interstitial space between buildings in urban environments. This is done by using computer simulation and in-situ observations at the extreme northern and southern geographies of Europe, namely in Luleå, Sweden and in Limassol, Cyprus. A typical example of the urban grid of each city is chosen and active solar systems are integrated on the facades of buildings, respectively foreach case. The thermal conditions at street level are then simulated, using Envi-MET, before and after systems integration, with the aim of assessing the differences between low and high insolation conditions, using the Physiological Equivalent Temperature (PET) indicator. Subsequently, the thermal conditions in the public space between buildings were once again assessed, with reduced emissivity values for the building integrated PV panels. The results point to the fact that the building integration of PVs lacking low emissivity coatings can have an impact in the thermal comfort of users in the locations specified, especially in the summer, wherein it is shown to be negligible in the southern case study but more significant in the northern one.
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| 30. |
- Wang, Zhaoming, et al.
(författare)
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Imputation and subset-based association analysis across different cancer types identifies multiple independent risk loci in the TERT-CLPTM1L region on chromosome 5p15.33
- 2014
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Ingår i: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 23:24, s. 6616-6633
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Tidskriftsartikel (refereegranskat)abstract
- Genome-wide association studies (GWAS) have mapped risk alleles for at least 10 distinct cancers to a small region of 63 000 bp on chromosome 5p15.33. This region harbors the TERT and CLPTM1L genes; the former encodes the catalytic subunit of telomerase reverse transcriptase and the latter may play a role in apoptosis. To investigate further the genetic architecture of common susceptibility alleles in this region, we conducted an agnostic subset-based meta-analysis (association analysis based on subsets) across six distinct cancers in 34 248 cases and 45 036 controls. Based on sequential conditional analysis, we identified as many as six independent risk loci marked by common single-nucleotide polymorphisms: five in the TERT gene (Region 1: rs7726159, P = 2.10 × 10(-39); Region 3: rs2853677, P = 3.30 × 10(-36) and PConditional = 2.36 × 10(-8); Region 4: rs2736098, P = 3.87 × 10(-12) and PConditional = 5.19 × 10(-6), Region 5: rs13172201, P = 0.041 and PConditional = 2.04 × 10(-6); and Region 6: rs10069690, P = 7.49 × 10(-15) and PConditional = 5.35 × 10(-7)) and one in the neighboring CLPTM1L gene (Region 2: rs451360; P = 1.90 × 10(-18) and PConditional = 7.06 × 10(-16)). Between three and five cancers mapped to each independent locus with both risk-enhancing and protective effects. Allele-specific effects on DNA methylation were seen for a subset of risk loci, indicating that methylation and subsequent effects on gene expression may contribute to the biology of risk variants on 5p15.33. Our results provide strong support for extensive pleiotropy across this region of 5p15.33, to an extent not previously observed in other cancer susceptibility loci.
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| 31. |
- Zhou, Huiquan, et al.
(författare)
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Predicting Emergency Department Utilization among Older Hong Kong Population in Hot Season: A Machine Learning Approach
- 2022
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Ingår i: Information. - : MDPI. - 2078-2489. ; 13:9
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Tidskriftsartikel (refereegranskat)abstract
- Previous evidence suggests that temperature is associated with the number of emergency department (ED) visits. A predictive system for ED visits, which takes local temperature into account, is therefore needed. This study aimed to compare the predictive performance of various machine learning methods with traditional statistical methods based on temperature variables and develop a daily ED attendance rate predictive model for Hong Kong. We analyzed ED utilization among Hong Kong older adults in May to September from 2000 to 2016. A total of 103 potential predictors were derived from 1- to 14-day lag of ED attendance rate and meteorological and air quality indicators and 0-day lag of holiday indicator and month and day of week indicators. LASSO regression was used to identify the most predictive temperature variables. Decision tree regressor, support vector machine (SVM) regressor, and random forest regressor were trained on the selected optimal predictor combination. Deep neural network (DNN) and gated recurrent unit (GRU) models were performed on the extended predictor combination for the previous 14-day horizon. Maximum ambient temperature was identified as a better predictor in its own value than as an indicator defined by the cutoff. GRU achieved the best predictive accuracy. Deep learning methods, especially the GRU model, outperformed conventional machine learning methods and traditional statistical methods.
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