260 research outputs found

    Landscape structure planning and the urban forest in polycentric city regions

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    © Published under licence by IOP Publishing Ltd. The World is continuing to urbanise at an increasing and some say alarming rate, and although urbanism is not uniform in all countries, without a doubt the 21 st century is the century of the Polycentric City Region. By the year 2007, for the first time in history, the world hosted more urban dwellers than rural, and in order to deal with this urban expansion in an environmentally acceptable way, the concept of the "sustainable compact city" was advocated. There is now an increasing canon of research however that suggests that such cities may not be quite as sustainable as they are claimed to be. As a consequence, the concept of "urban green infrastructure", which includes the concept of urban forestry, is being incorporated into new thinking on the landscape structure planning of expanding cities and city regions to ensure that they provide an acceptable quality of life for their inhabitants. The environmental, economic, social, health, well-being and cultural benefits that emanate from such an approach to promoting resilient landscape structure planning are considerable. Such an approach to landscape structure planning is well-able to repair the beneficial relationship that people once had with their landscapes, a relationship that has arguably suffered as our scientific and economic cultures have tended to gain the upper hand in the post-industrial times in which we live. Human beings have had a long, deep, cultural relationship with trees, woodlands and the landscape - a relationship which transcends national cultures. The use of the term "landscape" does not refer to the rather shallow modern concept of 'the landscape as a view", but to the more fundamental concept of "landscape as the composition of our world". Thus it refers to both urban, peri-urban and rural areas, and the urban forest is the prime spatial articulator of a landscape structure plan. Although the words "forest" and "forestry" are now generally understood to be connected with trees, the words have arguably been derived from the Latin word "foris", meaning "out of doors" or "unenclosed land" (Porteous, 1928 p34). Thus urban forestry could be described as the "urban out of doors". This presentation will consider the benefits that can be achieved from developing a viable urban forest structure as the backbone of a polycentric city region landscape structure plan. It will focus upon the Leeds Polycentric City Region in the UK and its emerging Leeds City Region Green and Blue Infrastructure Strategy 2017 - 2036 as a case study

    Exploring Self-organisation in Crowd Teams

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    Online crowds have the potential to do more complex work in teams, rather than as individuals. Team formation algorithms typically maximize some notion of global utility of team output by allocating people to teams or tasks. However, decisions made by these algorithms do not consider the decisions or preferences of the people themselves. This paper explores a complementary strategy, which relies on the crowd itself to self-organize into effective teams. Our preliminary results show that users perceive the ability to choose their teammate extremely useful in a crowdsourcing setting. We also find that self-organisation makes users feel more productive, creative and responsible for their work product

    Combined population genomic screening for three high-risk conditions in Australia: a modelling study

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    BACKGROUND: No previous health-economic evaluation has assessed the impact and cost-effectiveness of offering combined adult population genomic screening for mutliple high-risk conditions in a national public healthcare system. METHODS: This modeling study assessed the impact of offering combined genomic screening for hereditary breast and ovarian cancer, Lynch syndrome and familial hypercholesterolaemia to all young adults in Australia, compared with the current practice of clinical criteria-based testing for each condition separately. The intervention of genomic screening, assumed as an up-front single cost in the first annual model cycle, would detect pathogenic variants in seven high-risk genes. The simulated population was 18–40 year-olds (8,324,242 individuals), modelling per-sample test costs ranging AU100–100–1200 (base-case AU200)fromtheyear2023onwardswithtestinguptakeof50FINDINGS:Overthepopulationlifetime(toage80years),themodelestimatedthatgenomicscreeningper−100,000individualswouldleadto747QALYsgainedbypreventing63cancers,31CHDcasesand97deaths.Inthetotalmodelpopulation,thiswouldtranslateto31,094QALYsgainedbypreventing2612cancers,542non−fatalCHDeventsand4047totaldeaths.AtAU200) from the year 2023 onwards with testing uptake of 50%. Interventions for identified high-risk variant carriers follow current Australian guidelines, modelling imperfect uptake and adherence. Outcome measures were morbidity and mortality due to cancer (breast, ovarian, colorectal and endometrial) and coronary heart disease (CHD) over a lifetime horizon, from healthcare-system and societal perspectives. Outcomes included quality-adjusted life years (QALYs) and incremental cost-effectiveness ratio (ICER), discounted 5% annually (with 3% discounting in scenario analysis). FINDINGS: Over the population lifetime (to age 80 years), the model estimated that genomic screening per-100,000 individuals would lead to 747 QALYs gained by preventing 63 cancers, 31 CHD cases and 97 deaths. In the total model population, this would translate to 31,094 QALYs gained by preventing 2612 cancers, 542 non-fatal CHD events and 4047 total deaths. At AU200 per-test, genomic screening would require an investment of AU832millionforscreeningof50832 million for screening of 50% of the population. Our findings suggest that this intervention would be cost-effective from a healthcare-system perspective, yielding an ICER of AU23,926 (∼£12,050/€14,110/US15,345)perQALYgainedoverthestatusquo.Inscenarioanalysiswith315,345) per QALY gained over the status quo. In scenario analysis with 3% discounting, an ICER of AU4758/QALY was obtained. Sensitivity analysis for the base case indicated that combined genomic screening would be cost-effective under 70% of simulations, cost-saving under 25% and not cost-effective under 5%. Threshold analysis showed that genomic screening would be cost-effective under the AU50,000/QALYwillingness−to−paythresholdatper−testcostsuptoAU50,000/QALY willingness-to-pay threshold at per-test costs up to AU325 (∼£164/€192/US$208). INTERPRETATION: Our findings suggest that offering combined genomic screening for high-risk conditions to young adults would be cost-effective in the Australian public healthcare system, at currently realistic testing costs. Other matters, including psychosocial impacts, ethical and societal issues, and implementation challenges, also need consideration. FUNDING: Australian Government, Department of Health, Medical Research Future Fund, Genomics Health Futures Mission (APP2009024). National Heart Foundation Future Leader Fellowship (102604)

    Enhanced firing of locus coeruleus neurons and SK channel dysfunction are conserved in distinct models of prodromal Parkinson's disease

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    Parkinson’s disease (PD) is clinically defined by the presence of the cardinal motor symptoms, which are associated with a loss of dopaminergic nigrostriatal neurons in the substantia nigra pars compacta (SNpc). While SNpc neurons serve as the prototypical cell-type to study cellular vulnerability in PD, there is an unmet need to extent our efforts to other neurons at risk. The noradrenergic locus coeruleus (LC) represents one of the first brain structures affected in Parkinson’s disease (PD) and plays not only a crucial role for the evolving non-motor symptomatology, but it is also believed to contribute to disease progression by efferent noradrenergic deficiency. Therefore, we sought to characterize the electrophysiological properties of LC neurons in two distinct PD models: (1) in an in vivo mouse model of focal α-synuclein overexpression; and (2) in an in vitro rotenone-induced PD model. Despite the fundamental differences of these two PD models, α-synuclein overexpression as well as rotenone exposure led to an accelerated autonomous pacemaker frequency of LC neurons, accompanied by severe alterations of the afterhyperpolarization amplitude. On the mechanistic side, we suggest that Ca(2+)-activated K(+) (SK) channels are mediators of the increased LC neuronal excitability, as pharmacological activation of these channels is sufficient to prevent increased LC pacemaking and subsequent neuronal loss in the LC following in vitro rotenone exposure. These findings suggest a role of SK channels in PD by linking α-synuclein- and rotenone-induced changes in LC firing rate to SK channel dysfunction

    Bottom pressure signals at the TAG deep-sea hydrothermal field : evidence for short-period, flow-induced ground deformation

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    Author Posting. © American Geophysical Union, 2009. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 36 (2009): L19301, doi:10.1029/2009GL040006.Bottom pressure measurements acquired from the TAG hydrothermal field on the Mid-Atlantic Ridge (26°N) contain clusters of narrowband spectral peaks centered at periods from 22 to 53.2 minutes. The strongest signal at 53.2 min corresponds to 13 mm of water depth variation. Smaller, but statistically significant, signals were also observed at periods of 22, 26.5, 33.4, and 37.7 min (1–4 mm amplitude). These kinds of signals have not previously been observed in the ocean, and they appear to represent vertical motion of the seafloor in response to hydrothermal flow - similar in many ways to periodic terrestrial geysers. We demonstrate that displacements of 13 mm can be produced by relatively small flow-induced pressures (several kPa) if the source region is less than ∼100 m below the seafloor. We suggest that the periodic nature of the signals results from a non-linear relationship between fluid pore pressure and crustal permeability

    Quantifying the profile and progression of impairments, activity, participation, and quality of life in people with Parkinson disease : protocol for a prospective cohort study

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    Background Despite the finding that Parkinson disease (PD) occurs in more than one in every 1000 people older than 60 years, there have been few attempts to quantify how deficits in impairments, activity, participation, and quality of life progress in this debilitating condition. It is unclear which tools are most appropriate for measuring change over time in PD. Methods and design This protocol describes a prospective analysis of changes in impairments, activity, participation, and quality of life over a 12 month period together with an economic analysis of costs associated with PD. One-hundred participants will be included, provided they have idiopathic PD rated I-IV on the modified Hoehn & Yahr (1967) scale and fulfil the inclusion criteria. The study aims to determine which clinical and economic measures best quantify the natural history and progression of PD in a sample of people receiving services from the Victorian Comprehensive Parkinson\u27s Program, Australia. When the data become available, the results will be expressed as baseline scores and changes over 3 months and 12 months for impairment, activity, participation, and quality of life together with a cost analysis. Discussion This study has the potential to identify baseline characteristics of PD for different Hoehn & Yahr stages, to determine the influence of disease duration on performance, and to calculate the costs associated with idiopathic PD. Valid clinical and economic measures for quantifying the natural history and progression of PD will also be identified

    Divisive Gain Modulation with Dynamic Stimuli in Integrate-and-Fire Neurons

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    The modulation of the sensitivity, or gain, of neural responses to input is an important component of neural computation. It has been shown that divisive gain modulation of neural responses can result from a stochastic shunting from balanced (mixed excitation and inhibition) background activity. This gain control scheme was developed and explored with static inputs, where the membrane and spike train statistics were stationary in time. However, input statistics, such as the firing rates of pre-synaptic neurons, are often dynamic, varying on timescales comparable to typical membrane time constants. Using a population density approach for integrate-and-fire neurons with dynamic and temporally rich inputs, we find that the same fluctuation-induced divisive gain modulation is operative for dynamic inputs driving nonequilibrium responses. Moreover, the degree of divisive scaling of the dynamic response is quantitatively the same as the steady-state responses—thus, gain modulation via balanced conductance fluctuations generalizes in a straight-forward way to a dynamic setting
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