794 resultados para Robô Móvel


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Garlic mustard is a rapidly spreading, highly invasive non-native plant. It was introduced from Europe in mid-1800 for medicinal and herbal uses. Came to the United States without predatory beetles or other natural controls. Threatens to rob us of healthy, diverse native woodlands.

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The aim of this paper is to describe the process and challenges in building exposure scenarios for engineered nanomaterials (ENM), using an exposure scenario format similar to that used for the European Chemicals regulation (REACH). Over 60 exposure scenarios were developed based on information from publicly available sources (literature, books, and reports), publicly available exposure estimation models, occupational sampling campaign data from partnering institutions, and industrial partners regarding their own facilities. The primary focus was on carbon-based nanomaterials, nano-silver (nano-Ag) and nano-titanium dioxide (nano-TiO2), and included occupational and consumer uses of these materials with consideration of the associated environmental release. The process of building exposure scenarios illustrated the availability and limitations of existing information and exposure assessment tools for characterizing exposure to ENM, particularly as it relates to risk assessment. This article describes the gaps in the information reviewed, recommends future areas of ENM exposure research, and proposes types of information that should, at a minimum, be included when reporting the results of such research, so that the information is useful in a wider context.

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O presente estudo teve como objetivo a determinação do padrão de variação sazonal dos preços médios recebidos pelos produtores de abacaxi das Regiões Norte e Noroeste Fluminense, no período de janeiro de 1995 a dezembro de 2001. Para tanto, adotou-se a metodologia da média geométrica móvel centralizada de 12 meses. Os resultados do estudo mostraram uma sazonalidade de preços do abacaxi moderada. No período de janeiro a outubro, ocorreu certa estabilidade de preços, apresentando valores máximos nos meses de março e abril. Os meses de novembro e dezembro apresentaram os menores valores recebidos pelos produtores de abacaxi.

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1. The implementation of the Water Framework Directive requires EU member states to establish and harmonize ecological status class boundaries for biological quality elements. In this paper, we describe an approach for defining ecological class boundaries that delineates shifts in lake ecosystem functioning and, therefore, provides ecologically meaningful targets for water policy in Europe. 2. We collected an extensive data set of 810 lake-years from nine Central European countries, and we used phytoplankton chlorophyll a, a metric widely used to measure the impact of eutrophication in lakes. Our approach establishes chlorophyll a target values in relation to three significant ecological effects of eutrophication: the decline of aquatic macrophytes, the dominance of potentially harmful cyanobacteria and the major functional switch from a clear water to a turbid state. 3. Ranges of threshold chlorophyll a concentrations are given for the two most common lake types in lowland Central Europe: for moderately deep lakes (mean depth 3–15 m), the greatest ecological shifts occur in the range 10–12 lg L 1 chlorophyll a, and for shallow lakes (<3 m mean depth), in the range 21–23 lg L 1 chlorophyll a. 4. Synthesis and applications. Our study provides class boundaries for determining the ecological status of lakes, which have robust ecological consequences for lake functioning and which, therefore, provide strong and objective targets for sustainable water management in Europe. The results have been endorsed by all participant member states and adopted in the European Commission legislation, marking the first attempt in international water policy to move from physico-chemical quality standards to harmonized ecologically based quality targets.

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OBJETIVO: O objetivo deste trabalho foi estabelecer, no Laboratório de Calibração de Instrumentos do Instituto de Pesquisas Energéticas e Nucleares, uma metodologia de calibração específica para as câmaras de ionização tipo lápis, que são utilizadas em procedimentos dosimétricos em feixes de tomografia computadorizada, seguindo as mais recentes recomendações internacionais. MATERIAIS E MÉTODOS: Foram utilizados, neste estudo, um equipamento de radiação X industrial, várias câmaras de ionização, um sistema de colimação móvel (tipo diafragma) e vários filtros de alumínio de alta pureza. RESULTADOS: Foram estabelecidos os campos padrões de radiodiagnóstico descritos na norma internacional IEC 61267, e foi elaborado um procedimento de calibração adequado para as câmaras de ionização tipo lápis. CONCLUSÃO: Atualmente, já é possível calibrar apropriadamente as câmaras de ionização tipo lápis no Brasil. O procedimento de calibração foi definido com base nas recomendações internacionais e em testes feitos com duas metodologias distintas.

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BACKGROUND: The structure and organisation of ecological interactions within an ecosystem is modified by the evolution and coevolution of the individual species it contains. Understanding how historical conditions have shaped this architecture is vital for understanding system responses to change at scales from the microbial upwards. However, in the absence of a group selection process, the collective behaviours and ecosystem functions exhibited by the whole community cannot be organised or adapted in a Darwinian sense. A long-standing open question thus persists: Are there alternative organising principles that enable us to understand and predict how the coevolution of the component species creates and maintains complex collective behaviours exhibited by the ecosystem as a whole? RESULTS: Here we answer this question by incorporating principles from connectionist learning, a previously unrelated discipline already using well-developed theories on how emergent behaviours arise in simple networks. Specifically, we show conditions where natural selection on ecological interactions is functionally equivalent to a simple type of connectionist learning, 'unsupervised learning', well-known in neural-network models of cognitive systems to produce many non-trivial collective behaviours. Accordingly, we find that a community can self-organise in a well-defined and non-trivial sense without selection at the community level; its organisation can be conditioned by past experience in the same sense as connectionist learning models habituate to stimuli. This conditioning drives the community to form a distributed ecological memory of multiple past states, causing the community to: a) converge to these states from any random initial composition; b) accurately restore historical compositions from small fragments; c) recover a state composition following disturbance; and d) to correctly classify ambiguous initial compositions according to their similarity to learned compositions. We examine how the formation of alternative stable states alters the community's response to changing environmental forcing, and we identify conditions under which the ecosystem exhibits hysteresis with potential for catastrophic regime shifts. CONCLUSIONS: This work highlights the potential of connectionist theory to expand our understanding of evo-eco dynamics and collective ecological behaviours. Within this framework we find that, despite not being a Darwinian unit, ecological communities can behave like connectionist learning systems, creating internal conditions that habituate to past environmental conditions and actively recalling those conditions. REVIEWERS: This article was reviewed by Prof. Ricard V Solé, Universitat Pompeu Fabra, Barcelona and Prof. Rob Knight, University of Colorado, Boulder.

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BACKGROUND: The use of a robotic surgical system is claimed to allow precise traction and counter-traction, especially in a narrow pelvis. Whether this translates to improvement of the quality of the resected specimen is not yet clear. The aim of the study was to compare the quality of the TME and the short-term oncological outcome between robotic and laparoscopic rectal cancer resections. METHODS: 20 consecutive robotic TME performed in a single institution for rectal cancer (Rob group) were matched 1:2 to 40 laparoscopic resections (Lap group) for gender, body mass index (BMI), and distance from anal verge on rigid proctoscopy. The quality of TME was assessed by 2 blinded and independent pathologists and reported according to international standardized guidelines. RESULTS: Both samples were well matched for gender, BMI (median 25.9 vs. 24.2 kg/m(2), p = 0.24), and level of the tumor (4.1 vs. 4.8 cm, p = 0.20). The quality of the TME was better in the Robotic group (complete TME: 95 vs. 55 %; p = 0.0003, nearly complete TME 5 vs. 37 %; p = 0.04, incomplete TME 0 vs. 8 %, p = 0.09). A trend for lower positive circumferential margin was observed in the Robotic group (10 vs. 25 %, p = 0.1). CONCLUSIONS: These results suggest that robotic-assisted surgery improves the quality of TME for rectal cancer. Whether this translates to better oncological outcome needs to be further investigated.

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Samlingen med signum HF Etnol omfattar litteratur om etnologi och antropologi dels vid Humanistiska biblioteket och dels vid ämnet Etnologi. Vid huvudbiblioteket finns också etnologisk och antropologisk litteratur. De etnologiska och antropologiska samlingarna vid akademibiblioteket har byggts upp under lång tid genom bytesverksamhet, inköp och omfattande gåvor. Tidskrifter och årsböcker från hela Europa har kommit genom bytesverksamheten och en aktiv inköpspolitik har kompletterat samlingarna med såväl inhemsk som utländsk litteratur. Professorerna Gabriel Nikander och K.Rob.V.Wikman skaffade bägge stora samlingar etnologisk litteratur, som utgör stommen till de etnologiska samlingarna. Vidare har professor Sven-Erik Åströms samling av sockenhistoriker över svenska socknar i Finland donerats till institutionen. Värdefulla särtryckssamlingar om etnologi och antropologi samlade av professorerna Sigurd Erixon, Helmer Tegengren och Nils Storå förvaras på institutionen. Litteraturen i samlingen söks i databasen Alma med sökfunktionen Signum och söktermen HF Etnol.

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Alzheimer's disease (AD) is a neurodegenerative disease characterized by cognite impairment and personality changes. The development of drugs for the treatment of the cognitive deficits of AD has focused on agents which counteract loss in cholinergic activities. These symptons of AD have been successfully treated with acetylcholinesterase (AchE) inhibitors (eg. galanthamine). There still is great interest in finding better AchE inhibitors. We use Ellmann's microplate assay and silica gel thin-layer chromatography (TLC) to screen natural products from plants as new sources of AchE inhibitors.

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Invocatio: I.N.J.C.