872 resultados para Trees in cities
Resumo:
Nest site selection in arboreal, domatia-dwelling ants, particularly those coexisting on a single host plant, is little understood. To examine this phenomenon we studied the African savannah tree Vachellia erioloba, which hosts ants in swollen-thorn domatia. We found four ant species from different genera (Cataulacus intrudens, Tapinoma subtile, Tetraponera ambigua and an unidentified Crematogaster species). In contrast to other African ant plants, many V. erioloba trees (41 % in our survey) were simultaneously co-occupied by more than one ant species. Our study provides quantitative field data describing: (1) aspects of tree and domatia morphology relevant to supporting a community of mutualist ants, (2) how ant species occupancy varies with domatia morphology and (3) how ant colony size varies with domatia size and species. We found that Crematogaster sp. occupy the largest thorns, followed by C. intrudens, with T. subtile in the smallest thorns. Thorn age, as well as nest entrance hole size correlated closely with ant species occupant. These differing occupancy patterns may help to explain the unusual coexistence of three ant species on individual myrmecophytic trees. In all three common ant species, colony size, as measured by total number of ants, increased with domatia size. Additionally, domatia volume and species identity interact to predict ant numbers, suggesting differing responses between species to increased availability of nesting space. The proportion of total ants in nests that were immatures varied with thorn volume and species, highlighting the importance of domatia morphology in influencing colony structure.
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Full-waveform laser scanning data acquired with a Riegl LMS-Q560 instrument were used to classify an orange orchard into orange trees, grass and ground using waveform parameters alone. Gaussian decomposition was performed on this data capture from the National Airborne Field Experiment in November 2006 using a custom peak-detection procedure and a trust-region-reflective algorithm for fitting Gauss functions. Calibration was carried out using waveforms returned from a road surface, and the backscattering coefficient c was derived for every waveform peak. The processed data were then analysed according to the number of returns detected within each waveform and classified into three classes based on pulse width and c. For single-peak waveforms the scatterplot of c versus pulse width was used to distinguish between ground, grass and orange trees. In the case of multiple returns, the relationship between first (or first plus middle) and last return c values was used to separate ground from other targets. Refinement of this classification, and further sub-classification into grass and orange trees was performed using the c versus pulse width scatterplots of last returns. In all cases the separation was carried out using a decision tree with empirical relationships between the waveform parameters. Ground points were successfully separated from orange tree points. The most difficult class to separate and verify was grass, but those points in general corresponded well with the grass areas identified in the aerial photography. The overall accuracy reached 91%, using photography and relative elevation as ground truth. The overall accuracy for two classes, orange tree and combined class of grass and ground, yielded 95%. Finally, the backscattering coefficient c of single-peak waveforms was also used to derive reflectance values of the three classes. The reflectance of the orange tree class (0.31) and ground class (0.60) are consistent with published values at the wavelength of the Riegl scanner (1550 nm). The grass class reflectance (0.46) falls in between the other two classes as might be expected, as this class has a mixture of the contributions of both vegetation and ground reflectance properties.
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Cities are responsible for up to 70% of global carbon emissions and 75% of global energy consumption. By 2050 it is estimated that 70% of the world's population will live in cities. The critical challenge for contemporary urbanism, therefore, is to understand how to develop the knowledge, capacity and capability for public agencies, the private sector and multiple users in city-regions (i.e. the city and its wider hinterland) to re-engineer systemically their built environment and urban infrastructure in response to climate change and resource constraints. To inform transitions to urban sustainability, key stakeholders' perceptions were sought though a participatory backcasting and scenario foresight process in order to illuminate challenging but realistic socio-technical scenarios for the systemic retrofit of core UK city-regions. The challenge of conceptualizing complex urban transitions is explored across multiple socio-technical ‘regimes’ (housing, non-domestic buildings, urban infrastructure), scales (building, neighbourhood, city-region), and domains (energy, water, use of resources) within a participatory process. The development of three archetypal ‘guiding visions’ of retrofit city-regional futures developed through this process are discussed, along with the contribution that such foresight processes might play in ‘opening up’ the governance and strategic navigation of urban sustainability.
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Cities, which are now inhabited by a majority of the world's population, are not only an important source of global environmental and resource depletion problems, but can also act as important centres of technological innovation and social learning in the continuing quest for a low carbon future. Planning and managing large-scale transitions in cities to deal with these pressures require an understanding of urban retrofitting at city scale. In this context performative techniques (such as backcasting and roadmapping) can provide valuable tools for helping cities develop a strategic view of the future. However, it is also important to identify ‘disruptive’ and ‘sustaining’ technologies which may contribute to city-based sustainability transitions. This paper presents research findings from the EPSRC Retrofit 2050 project, and explores the relationship between technology roadmaps and transition theory literature, highlighting the research gaps at urban/city level. The paper develops a research methodology to describe the development of three guiding visions for city-regional retrofit futures, and identifies key sustaining and disruptive technologies at city scale within these visions using foresight (horizon scanning) techniques. The implications of the research for city-based transition studies and related methodologies are discussed.
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Climate data are used in a number of applications including climate risk management and adaptation to climate change. However, the availability of climate data, particularly throughout rural Africa, is very limited. Available weather stations are unevenly distributed and mainly located along main roads in cities and towns. This imposes severe limitations to the availability of climate information and services for the rural community where, arguably, these services are needed most. Weather station data also suffer from gaps in the time series. Satellite proxies, particularly satellite rainfall estimate, have been used as alternatives because of their availability even over remote parts of the world. However, satellite rainfall estimates also suffer from a number of critical shortcomings that include heterogeneous time series, short time period of observation, and poor accuracy particularly at higher temporal and spatial resolutions. An attempt is made here to alleviate these problems by combining station measurements with the complete spatial coverage of satellite rainfall estimates. Rain gauge observations are merged with a locally calibrated version of the TAMSAT satellite rainfall estimates to produce over 30-years (1983-todate) of rainfall estimates over Ethiopia at a spatial resolution of 10 km and a ten-daily time scale. This involves quality control of rain gauge data, generating locally calibrated version of the TAMSAT rainfall estimates, and combining these with rain gauge observations from national station network. The infrared-only satellite rainfall estimates produced using a relatively simple TAMSAT algorithm performed as good as or even better than other satellite rainfall products that use passive microwave inputs and more sophisticated algorithms. There is no substantial difference between the gridded-gauge and combined gauge-satellite products over the test area in Ethiopia having a dense station network; however, the combined product exhibits better quality over parts of the country where stations are sparsely distributed.
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Cities have developed into the hotspots of human economic activity. From the appearance of the first cities in the Neolithic to 21st century metropolis their impact on the environment has always been apparent. With more people living in cities than in rural environments now it becomes crucial to understand these environmental impacts. With the immergence of megacities in the 20th century and their continued growth in both, population and economic power, the environmental impact has reached the global scale. In this paper we examine megacity impacts on atmospheric composition and climate. We present basic concepts, discuss various definitions of footprints, summarize research on megacity impacts and assess the impact of megacity emissions on air quality and on the climate at the regional to global scale. The intention and ambition of this paper is to give a comprehensive but brief overview of the science with regard to megacities and the environment.
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Climate projections show Australia becoming significantly warmer during the 21st century, and precipitation decreasing over much of the continent. Such changes are conventionally considered to increase wildfire risk. Nevertheless, we show that burnt area increases in southern Australia, but decreases in northern Australia. Overall the projected increase in fire is small (0.72–1.31% of land area, depending on the climate scenario used), and does not cause a decrease in carbon storage. In fact, carbon storage increases by 3.7–5.6 Pg C (depending on the climate scenario used). Using a process-based model of vegetation dynamics, vegetation–fire interactions and carbon cycling, we show increased fire promotes a shift to more fire-adapted trees in wooded areas and their encroachment into grasslands, with an overall increase in forested area of 3.9–11.9%. Both changes increase carbon uptake and storage. The increase in woody vegetation increases the amount of coarse litter, which decays more slowly than fine litter hence leading to a relative reduction in overall heterotrophic respiration, further reducing carbon losses. Direct CO2 effects increase woody cover, water-use efficiency and productivity, such that carbon storage is increased by 8.5–14.8 Pg C compared to simulations in which CO2 is held constant at modern values. CO2 effects tend to increase burnt area, fire fluxes and therefore carbon losses in arid areas, but increase vegetation density and reduce burnt area in wooded areas.
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Weather, climate, water and related environmental conditions, including air quality, all have profound effects on cities. A growing importance is being attached to understanding and predicting atmospheric conditions and their interactions with other components of the Earth System in cities, at multiple scales. We highlight the need for: (1) development of high-resolution coupled environmental prediction models that include realistic city-specific processes, boundary conditions and fluxes; (2) enhanced observational systems to support (force, constrain, evaluate) these models to provide high quality forecasts for new urban services; (3) provision of meteorological and related environmental variables to aid protection of human health and the environment; (4) new targeted and customized delivery platforms using modern communication techniques, developed with users to ensure that services, advice and warnings result in appropriate action; and (5) development of new skill and capacity to make best use of technologies to deliver new services in complex, challenging and evolving city environments. We highlight the importance of a coordinated and strategic approach that draws on, but does not replicate, past work to maximize benefits to stakeholders.
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We examine the black box of creativity, entrepreneurship and economic development by asking about the mechanisms through which creativity can influence economic development in cities. We propose that, like the knowledge spillover theory of entrepreneurship, creativity spillovers occur and can be slowed by a creativity filter. We examine how creativity and entrepreneurship, and creativity and a melting pot environment, interact to influence urban economic development. Using data on 187 cities in 15 European countries for the period 1999–2009, we advance the extant literature by providing evidence on the existence and dynamics of a creativity filter.
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Tribe Rhipsalideae is composed of unusual epiphytic or lithophytic cacti that inhabit humid tropical and subtropical forests. Members of this tribe present a reduced vegetative body, a specialized adventitious root system, usually spineless areoles and flowers and fruits reduced in size. Despite the debate surrounding the classification of Rhipsalideae, no studies have ever attempted to reconstruct phylogenetic relationships among its members or to test the monophyly of its genera using DNA sequence data; all classifications formerly proposed for this tribe have only employed morphological data. In this study, we reconstruct the phylogeny of Rhipsalideae using plastid (trnQ-rps16, rpl32-trnL, psbA-trnH) and nuclear (ITS) markers to evaluate the classifications previously proposed for the group. We also examine morphological features traditionally used to delimit genera within Rhipsalideae in light of the resulting phylogenetic trees. In total new sequences for 35 species of Rhipsalideae were produced (out of 55: 63%). The molecular phylogeny obtained comprises four main clades supporting the recognition of genera Lepismium, Rhipsalis, Hatiora and Schlumbergera. The evidence gathered indicate that a broader genus Schlumbergera, including Hatiora subg. Rhipsalidopsis, should be recognized. Consistent morphological characters rather than homoplastic features are used in order to establish a more coherent and practical classification for the group. Nomenclatural changes and a key for the identification of the genera currently included in Rhipsalideae are provided. (C) 2011 Elsevier Inc. All rights reserved.
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The continuous search of the increase of the productivity has been facilitating the growing diffusion of modern and advanced technologies, that open new ways for the renovation of the industrial productive process, as well as, to the appearance of modern administration systems that establish ways in direction to the democratization of the social relationships in the organizations. Accompanying that tendency and, motivated by the competitive characteristic of the market of electric energy, Eletronorte, adopted the Total Productive Maintenance - TPM, of japanese origin, as the system of administration of its productive process. This dissertation has as objective, to analyze the methodological content of the Total Productive Maintenance, showing its significance and its reach in the Regional of Transmission of Mato Grosso, adopting the post fordism, as comparison paradigm. The whole study and analysis had as focus the offices of the company and the Substation of Coxipó, placed in the city of Cuiabá, as well as the Substations of Rondonópolis and Sinop, placed in cities with the same name. The offices and the substations are geographically located in the state of Mato Grosso, and under the responsibility of the Regional of Transmission of Mato Grosso, of the Centrais Elétricas do Norte do Brasil SA - Eletronorte. The work method was of qualitative orientation and of case study, through a research of applied nature. The research was accomplished with explanatory and exploratory objectives. They were used as instruments of collection of data the analysis of documents, interviews, and application of questionnaires. The data collected through documents and of the application of questionnaires they were compiled and analyzed. The results of the interviews had for objective to confirm the consistency of the collected data. The obtained results demonstrate increases of productivity of the order of 40%, and reduction of the costs of up to 29%. The study still demonstrated, that TPM provoked significant impacts in the practices you work, denoting the presence of an action managerial dialógica. It was still characterized that the transference of TPM will depend in that context the administration system will be applied, because if this is here different from it studied, there won't be transference warranties.
Resumo:
Esta dissertação estuda a questão da continuidade e descontinuidade de políticas públicas em governos municipais. Apesar do tema ser muito presente na fala e no cotidiano de gestores, pesquisadores, servidores públicos e jornalistas, há poucos estudos que realmente aprofundem como se dão esses fenômenos. Os poucos trabalhos realizados apontam primeiro para o paradoxo democrático da questão ¿ ainda que a descontinuidade seja normalmente considerada indesejável, ela é um dos pressupostos básicos da alternância de poder que a rotina democrática requer. Além disso, há quem aponte que os dois fenômenos possam estar mais ligados do que numa análise superficial. Por último, alguns estudos sugerem que possa haver mais continuidade do que o senso comum levaria a crer, ainda que as explicações para essa realidade ainda estejam pouco elaboradas. É nesta direção que o presente trabalho pretende contribuir. O objetivo principal desta pesquisa foi avançar na compreensão dos fatores que favorecem a continuidade de ações públicas em governos locais no Brasil. Neste sentido, a parte teórica do trabalho incluiu uma revisão de modelos de políticas públicas uitilizados como lente teórica à observação da pesquisa empírica. Também foram revistos alguns textos sobre o local e suas políticas de desenvolvimento, priorizados como objetos de estudo desta dissertação. Foram então realizados três estudos de caso de diferentes políticas de desenvolvimento local. As iniciativas estudadas foram escolhidas a partir do banco de experiências do Programa Gestão Pública e Cidadania, selecionando projetos realizados em cidades com mais de 200 mil habitantes e que já tenham passado por pelo menos três eleições municipais. Os casos estudados foram o Programa de Coleta Seletiva de Lixo de Embu (SP), o Programa de Produção Associada com Garantia de Renda Mínima de Jundiaí (SP) e a Instituição Comunitária de Microcrédito Portosol de Porto Alegre (RS). As análises apontam para a existência de pelo menos quatro fatores que favorecem a continuidade de iniciativas públicas em governos locais. Em primeiro lugar, notou-se a importância de que se desenvolvam ações intencionais para tanto. Além disso, são igualmente importantes fatores técnicos e políticos. Por último, sugere-se que a inserção do projeto ou instituição em coalizões consistentes é benéfico à sua continuidade.
Resumo:
O presente trabalho aborda o desempenho dos sistemas municipais de saúde, tendo como foco a saúde materno-infantil. Com o objetivo de apontar as possíveis fragilidades dos sistemas de saúde, especificamente daqueles em que a Atenção Primária (AP) é a principal ou exclusiva estratégia de atuação da gestão municipal, foi criado um modelo teórico de avaliação dos indicadores de saúde, denominado de ADS. Aplicado às cidades com população entre 14 mil e 35 mil habitantes, onde o sistema de saúde se baseia exclusivamente na política de AP, esse modelo foi construído por meio da técnica de consenso, com a formação de um grupo de 12 especialistas na área de saúde coletiva para definição e validação de critérios para análise dos sistemas. Testado na cidade de Iati, localizada no Agreste Meridional e distante 282 quilômetros da capital pernambucana, o ADS apontou fatores ambientais e socioeconômicos abaixo da média, além de vulnerabilidades da assistência materno-infantil que influenciam negativamente a situação de saúde do município. A avaliação verificou ainda desempenho insatisfatório no que diz respeito ao acompanhamento das crianças e gestantes por meio de consultas médicas (efetividade); assistência à criança (continuidade); cobertura de consultas em crianças e imunização de gestantes (acesso aos serviços da Atenção Primária); produtividade das ações realizadas pelos profissionais de saúde (eficiência) e capacidade de investigação dos óbitos infantis, qualidade dos registros e controle da sífilis em gestantes (vigilância à saúde). Também foi observada baixa alocação de investimentos em saúde em combinação com a carência de recursos humanos e materiais para prestar os serviços. Ao final da pesquisa, foi possível constatar a viabilidade de aplicação do modelo para planejamento das auditorias, avaliando o desempenho dos indicadores de saúde no âmbito municipal.
Resumo:
Este estudo buscou identificar e analisar como foi planejado e executado o processo de descentralização da perícia criminal federal, bem assim, identificar a razão para os desvios havidos entre o planejamento e a implementação e as consequências advindas. Uma revisão da teoria precedeu a análise dos dados, obtidos através de pesquisa de campo constituída por oito entrevistas, sendo cinco entre os planejadores e executores do processo de descentralização, e três com os responsáveis por unidades descentralizadas. O planejamento do processo de descentralização foi realizado por equipes intermediárias do escalão dirigente do Departamento de Polícia Federal. Conforme levantamento empreendido por esses idealizadores, constatou-se uma alta demanda por assistência pericial em investigações conduzidas em cidades afastadas das capitais dos estados, onde residia o único centro forense disponível em cada unidade da federação. A distância do local da demanda para as capitais e a limitada capacidade de atendimento das unidades estaduais prevenia o atendimento tempestivo das requisições, situação que, por vezes, comprometia toda a eficácia da investigação policial. A par dessas constatações e tendo sido identificadas as principais especialidades requeridas, o volume de solicitações, a infraestrutura local disponível e outras características associadas à demanda e aos seus locais de origem, foram delimitados requisitos para a identificação de cidades que receberiam unidades técnico-científicas e delimitação das características dessas unidades. Os parâmetros fixados para dimensionar as unidades descentralizadas, como requisitos de infraestrutura, recursos humanos e equipamentos, acabaram por ser flexibilizados durante o processo de implementação devido à insuficiência de recursos financeiros para a implementação concebida. Como resultado, houve instalação de unidades incompletas; com corpo técnico carente das expertises requeridas; com infraestrutura física inadequada; em localidades não previstas; sem os laboratórios e equipamentos necessários. Os empecilhos indicados sinalizam que o plano foi estabelecido sem a análise precisa das forças e fraquezas, oportunidades e desafios que impactariam a sua execução. A ausência do envolvimento da alta administração da Polícia Federal pode explicar parte das deficiências encontradas no processo. Embora a descentralização tenha melhorado as condições para a atuação das equipes de investigação, diversas deficiências ainda precisam ser suprimidas para garantir melhor efetividade da assistência da perícia. Conclui-se pela necessidade de uma completa revisão do processo de descentralização da estrutura pericial, a fim de se identificar os ajustes necessários para o aprimoramento das condições de operação das unidades técnico-científicas descentralizadas.
Resumo:
Este trabalho teve como objetivo analisar o uso da biometria no serviço público como forma de redução das oportunidades de fraudes e melhoria da gestão de pessoas na administração pública. Para isso, foi feita uma comparação semiestruturada da experiência internacional e um estudo de caso aprofundado do projeto Identidade Funcional, desenvolvido pelo governo do Estado do Rio de Janeiro. As lições mais importantes, derivadas destas experiências, estão refletidas em um modelo de projeto para formação de uma base biométrica capaz de garantir a integridade do cadastro de pagamento dos salários e benefícios de previdência da administração pública. O modelo tomou por referência a prefeitura de Duque de Caxias, porém foi estruturado de modo a ser viável em municípios do mesmo porte.