838 research outputs found

    The rarity of direct experiences of nature in an urban population

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    This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.As people live more urbanised lifestyles there is potential to lose daily contact with nature, diminishing access to the wide range of associated health benefits of interacting with nature. Experiences of nature vary widely across populations, but this variation is poorly understood. We surveyed 1,023 residents of an urban population in the UK to measure four distinctly different nature interactions: indirect (viewing nature through a window at work and at home), incidental (spending time outside at work), intentional (time spent in private gardens) and intentional (time spent in public parks). Scaled-up to the whole study population, accumulation curves of the total number of hours per week that people were exposed to each type of nature interaction showed that 75% of nature interactions were experienced by half the population. Moreover, 75% of the interactions of a type where people were actually present in nature were experienced by just 32% of the population. The average hours each individual experienced nature per week varied across interactions: indirect (46.0 ± 27.3 SD), incidental (6.4 ± 12.7 SD), intentional-gardens (2.5 ± 2.9 SD) and intentional-parks (2.3 ± 2.7 SD). Experiencing nature regularly appears to be the exception rather than the norm, with a person’s connection to nature being positively associated with incidental and intentional experiences. This novel study provides baseline information regarding how an urban population experiences different types of nature. Deconstructing nature experience will pave the way for developing recommendations for targeted health outcomes.DTCC, HLH & KJG were funded by NERC grant NE/J015237/1. D.F.S. is supported through ARC Discovery Grant DP120102857 and the Centre of Excellence for Environmental Decisions (CEED, Australia); R.A.F. holds an ARC Future Fellowship

    The impact of urbanisation on nature dose and the implications for human health

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    This is the final version. Available from Elsevier via the DOI in this record.The last 100 years have seen a huge change in the global structure of the human population, with the majority of people now living in urban rather than rural environments. An assumed consequence is that people will have fewer experiences of nature, and this could have important consequences given the myriad health benefits that they can gain from such experiences. Alternatively, as experiences of nature become rarer, people might be more likely actively to seek them out, mitigating the negative effects of urbanisation. In this study, we used data for 3000 survey respondents from across the UK, and a nature-dose framework, to determine whether (a) increasing urbanisation is associated with a decrease in the frequency, duration and intensity of nature dose; and (b) differences in nature exposure associated with urbanisation impact on four population health outcomes (depression, self-reported health, social cohesion and physical activity). We found negative exponential relationships between nature dose and the degree of urbanisation. The frequency and duration of dose decreased from rural to suburban environments, followed by little change with further increases in urbanisation. There were weak but positive associations between frequency and duration of dose across all four health domains, while different dimensions of dose showed more positive associations with specific health domains in towns and cities. We show that people in urban areas with a low nature dose tend to have worse health across multiple domains, but have the potential for the greatest gains from spending longer in nature, or living in green areas.D.T.C.C, H.L.H. and K.J.G were supported by the Fragments, Functions, Flows and Urban Ecosystem Services project, NERC grant NE/J015237/1, funded under the NERC Biodiversity and Ecosystem Service Sustainability program

    Health benefits from nature experiences depend on dose

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    Nature within cities will have a central role in helping address key global public health 3 challenges associated with urbanization. However, there is almost no guidance on how much 4 or how frequently people need to engage with nature, and what types or characteristics of 5 nature need to be incorporated in cities for the best health outcomes. Here we use a nature 6 dose framework to examine the associations between the duration, frequency and intensity of 7 exposure to nature and health in an urban population. We show that people who made long 8 visits to green spaces had lower rates of depression and high blood pressure, and those who 9 visited more frequently had greater social cohesion. Higher levels of physical activity were 10 linked to both duration and frequency of green space visits. A dose-response analysis for 11 depression and high blood pressure suggest that visits to outdoor green spaces of 30 minutes 12 or more during the course of a week could reduce the population prevalence of these illnesses 13 by up to 7% and 9% respectively. Given that the societal costs of depression alone in 14 Australia are estimated at AUD$12.6 billion per annum, savings to public health budgets 15 across all health outcomes could be immense.D.F.S. is supported through ARC Discovery Grant DP120102857 and the Centre of Excellence for Environmental Decisions (CEED, Australia); R.A.F. holds an ARC Future Fellowship; B.B.L. is supported through the CSIRO Land and Water Flagship; and K.J.G. is supported by NERC grant NE/J015237/1. J. Rhodes, K. Johansen and S. Wu contributed to the development of the vegetation data. Authors would like to thank the Brisbane City Council for providing GIS data layers, the Department of Science, Information Technology and Innovation and the Department of Natural Resources and Mines, QLD for providing access to the airborne LiDAR

    Doses of neighborhood nature: the benefits for mental health of living with nature

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    This is the author accepted manuscript. The final version is available from OUP via the DOI in this record.Experiences of nature provide many mental health benefits, particularly for people living in urban areas. The natural characteristics of city residents’ neighborhoods are likely to be critical determinants of the daily nature dose that they receive, however which characteristics are important remains unclear. One possibility is that the greatest benefits are provided by characteristics that are most visible during the day and so most likely to be experienced by people. We demonstrate that of five neighborhood nature characteristics tested, vegetation cover and afternoon bird abundances were positively associated with a lower prevalence of depression, anxiety and stress. Further, dose-response modelling shows a threshold response where the population prevalence of mental health issues is significantly lower beyond minimum limits of neighborhood vegetation cover (depression >20% cover, anxiety >30% cover, stress >20% cover). Our findings demonstrate quantifiable associations of mental health with the characteristics of nearby nature that people actually experience

    Winter Bird Assemblages in Rural and Urban Environments: A National Survey

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    Urban development has a marked effect on the ecological and behavioural traits of many living organisms, including birds. In this paper, we analysed differences in the numbers of wintering birds between rural and urban areas in Poland. We also analysed species richness and abundance in relation to longitude, latitude, human population size, and landscape structure. All these parameters were analysed using modern statistical techniques incorporating species detectability. We counted birds in 156 squares (0.25 km2 each) in December 2012 and again in January 2013 in locations in and around 26 urban areas across Poland (in each urban area we surveyed 3 squares and 3 squares in nearby rural areas). The influence of twelve potential environmental variables on species abundance and richness was assessed with Generalized Linear Mixed Models, Principal Components and Detrended Correspondence Analyses. Totals of 72 bird species and 89,710 individual birds were recorded in this study. On average (±SE) 13.3 ± 0.3 species and 288 ± 14 individuals were recorded in each square in each survey. A formal comparison of rural and urban areas revealed that 27 species had a significant preference; 17 to rural areas and 10 to urban areas. Moreover, overall abundance in urban areas was more than double that of rural areas. There was almost a complete separation of rural and urban bird communities. Significantly more birds and more bird species were recorded in January compared to December. We conclude that differences between rural and urban areas in terms of winter conditions and the availability of resources are reflected in different bird communities in the two environments

    The co-development of HedgeDATE, a public engagement and decision support tool for air pollution exposure mitigation by green infrastructure

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    There is a lack of clear guidance regarding the optimal configuration and plant composition of green infrastructure (GI) for improved air quality at local scale. This study aimed to co-develop (i.e. with feedback from end-users) a public engagement and decision support tool, to facilitate effective GI design and management for air pollution abatement. The underlying model uses user-directed input data (e.g. road type) to generate output recommendations (e.g. plant species) and pollution reduction projections. This model was computerised as a user-friendly tool named HedgeDATE (Hedge Design for Abatement of Traffic Emissions). A workshop generated feedback on HedgeDATE, which we also discuss. We found that data from the literature can be synthesised to predict air pollutant exposure and abatement in open road environments. However, further research is required to describe pollutant decay profiles under more diverse roadside scenarios (e.g. split-level terrain) and to strengthen projections. Workshop findings validated the HedgeDATE concept and indicated scope for uptake. End-user feedback was generally positive, although potential improvements were identified. For HedgeDATE to be made relevant for practitioners and decision-makers, future iterations will require enhanced applicability and functionality. This work sets the foundation for the development of advanced GI design tools for reduced pollution exposure

    Exhausted CD8 T Cells Downregulate the IL-18 Receptor and Become Unresponsive to Inflammatory Cytokines and Bacterial Co-infections

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    During many chronic infections virus-specific CD8 T cells succumb to exhaustion as they lose their ability to respond to antigenic activation. Combinations of IL-12, IL-18, and IL-21 have been shown to induce the antigen-independent production of interferon (IFN)-γ by effector and memory CD8 T cells. In this study we investigated whether exhausted CD8 T cells are sensitive to activation by these cytokines. We show that effector and memory, but not exhausted, CD8 T cells produce IFN-γ and upregulate CD25 following exposure to certain combinations of IL-12, IL-18, and IL-21. The unresponsiveness of exhausted CD8 T cells is associated with downregulation of the IL-18-receptor-α (IL-18Rα). Although IL-18Rα expression is connected with the ability of memory CD8 T cells to self-renew and efflux rhodamine 123, the IL-18Rαlo exhausted cells remained capable of secreting this dye. To further evaluate the consequences of IL-18Rα downregulation, we tracked the fate of IL-18Rα-deficient CD8 T cells in chronically infected mixed bone marrow chimeras and discovered that IL-18Rα affects the initial but not later phases of the response. The antigen-independent responsiveness of exhausted CD8 T cells was also investigated following co-infection with Listeria monocytogenes, which induces the expression of IL-12 and IL-18. Although IL-18Rαhi memory cells upregulated CD25 and produced IFN-γ, the IL-18Rαlo exhausted cells failed to respond. Collectively, these findings indicate that as exhausted T cells adjust to the chronically infected environment, they lose their susceptibility to antigen-independent activation by cytokines, which compromises their ability to detect bacterial co-infections

    Electron quantum metamaterials in van der Waals heterostructures

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    In recent decades, scientists have developed the means to engineer synthetic periodic arrays with feature sizes below the wavelength of light. When such features are appropriately structured, electromagnetic radiation can be manipulated in unusual ways, resulting in optical metamaterials whose function is directly controlled through nanoscale structure. Nature, too, has adopted such techniques -- for example in the unique coloring of butterfly wings -- to manipulate photons as they propagate through nanoscale periodic assemblies. In this Perspective, we highlight the intriguing potential of designer sub-electron wavelength (as well as wavelength-scale) structuring of electronic matter, which affords a new range of synthetic quantum metamaterials with unconventional responses. Driven by experimental developments in stacking atomically layered heterostructures -- e.g., mechanical pick-up/transfer assembly -- atomic scale registrations and structures can be readily tuned over distances smaller than characteristic electronic length-scales (such as electron wavelength, screening length, and electron mean free path). Yet electronic metamaterials promise far richer categories of behavior than those found in conventional optical metamaterial technologies. This is because unlike photons that scarcely interact with each other, electrons in subwavelength structured metamaterials are charged, and strongly interact. As a result, an enormous variety of emergent phenomena can be expected, and radically new classes of interacting quantum metamaterials designed
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