49 research outputs found

    Forest fire warning system

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    Orientadores: João Frederico da Costa Azevedo Meyer, Laécio Carvalho de BarrosTese (doutorado) - Universidade Estadual de Campinas, Instituto de Matemática Estatística e Computação CientíficaResumo: O principal objetivo desta tese é apresentar um sistema de alerta antecipado de incêndio florestal. Este sistema é baseado em três subsistemas acoplados: um \textbf{classificador kNN fuzzy}, que a partir das variáveis distâncias para curso d'água e estrada mais próximos, altitude e tipologia florestal, gera o índice de risco de incêndio florestal, um algoritmo \textit{\textbf{Subtractive Clustering}} e um \textbf{sistema fuzzy} que geram o perigo de incêndio florestal. De modo acoplado o risco e perigo de incêndio florestal podem simular a evolução espaço-temporal do índice de alerta de incêndio. A saída destes sistemas é entendida como pertinências de subconjuntos fuzzy. O alerta de incêndio florestal é utilizado para gerar simulações de propagação de incêndio a partir de metodologia de autômatos celulares. Propomos duas metodologias distintas para obtermos o perigo de incêndio florestal: a primeira consiste em utilizar um sistema fuzzy, que realiza métodos de aprendizagem supervisionada e não supervisionada, para fornecer uma série temporal de valores de perigo e que depende apenas de variáveis climáticas (umidade relativa do ar e precipitação); a segunda envolve um sistema dinâmico fuzzy que gera a mesma série temporal a partir de um sistema baseado em regras fuzzy com as mesmas variáveis de entrada do modelo de aprendizado de máquina. O índice de perigo gerado por esses modelos funciona também como regulador da dinâmica temporal do alerta de incêndio. Os modelos matemáticos são aplicados a dados reais geo-referenciados do Estado do Acre-BrasilAbstract: The main purpose of this thesis is to present a fire forest early warning system. This system is based on three coupled subsystems: a fuzzy kNN classifier, which generates the forest fire risk index from the distances to the nearest watercourse and road, altitude and forest typology; a \textbf{Subtractive Clustering} algorithm and a \textbf{fuzzy system} that create the danger of forest fire. In a coupled way the risk and danger of forest fire can simulate the spatio-temporal evolution of the fire warning index. The forest fire warning is used to generate simulations of fire spread using cellular automata methodology. We propose two different methodologies to obtain the forest fire danger: the first is based upon a fuzzy system that performs supervised and unsupervised learning methods providing a time series of danger values and depends only on climatic variables (air relative humidity and rainfall); The second involves a dynamic fuzzy system which generates the same time series from a system based on fuzzy rules with the same input variables as the machine-learning model. The index of danger generated by these models also acts as a regulator of the temporal dynamics of the warning of fire. The mathematical models are applied to real georeferenced data from the State of Acre-BrazilDoutoradoMatematica AplicadaDoutor em Matemática AplicadaCAPE

    Landmarks in Existing Tissue at Wounds Are Utilized to Generate Pattern in Regenerating Tissue

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    Regeneration in many organisms involves the formation of a blastema, which differentiates and organizes into the appropriate missing tissues. How blastema pattern is generated and integrated with pre-existing tissues is a central question in the field of regeneration. Planarians are free-living flatworms capable of rapidly regenerating from small body fragments [1]. A cell cluster at the anterior tip of planarian head blastemas (the anterior pole) is required for anterior-posterior (AP) and medial-lateral (ML) blastema patterning [2–4]. Transplantation of the head tip into tails induced host tissues to grow patterned head-like outgrowths containing a midline. Given the important patterning role of the anterior pole, understanding how it becomes localized during regeneration would help explain how wounds establish pattern in new tissue. Anterior pole progenitors were specified at the pre-existing midline of regenerating fragments, even when this location deviated from the ML median plane of the wound face. Anterior pole progenitors were specified broadly on the dorsal-ventral (DV) axis and subsequently formed a cluster at the DV boundary of the animal. We propose that three landmarks of pre-existing tissue at wounds set the location of anterior pole formation: a polarized AP axis, the pre-existing midline, and the dorsal-ventral median plane. Subsequently, blastema pattern is organized around the anterior pole. This process, utilizing positional information in existing tissue at unpredictably shaped wounds, can influence the patterning of new tissue in a manner that facilitates integration with pre-existing tissue in regeneration.National Institute of General Medical Sciences (U.S.) (Award T32GM007753)National Institutes of Health (U.S.) (Grant R01GM080639

    Electrotonic Signals along Intracellular Membranes May Interconnect Dendritic Spines and Nucleus

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    Synapses on dendritic spines of pyramidal neurons show a remarkable ability to induce phosphorylation of transcription factors at the nuclear level with a short latency, incompatible with a diffusion process from the dendritic spines to the nucleus. To account for these findings, we formulated a novel extension of the classical cable theory by considering the fact that the endoplasmic reticulum (ER) is an effective charge separator, forming an intrinsic compartment that extends from the spine to the nuclear membrane. We use realistic parameters to show that an electrotonic signal may be transmitted along the ER from the dendritic spines to the nucleus. We found that this type of signal transduction can additionally account for the remarkable ability of the cell nucleus to differentiate between depolarizing synaptic signals that originate from the dendritic spines and back-propagating action potentials. This study considers a novel computational role for dendritic spines, and sheds new light on how spines and ER may jointly create an additional level of processing within the single neuron

    Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

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    Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

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    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat
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