Probabilistic fire spread forecast as a management tool in an operational setting

Background: An approach to predict fire growth in an operational setting, with the potential to be used as a decision-support tool for fire management, is described and evaluated. The operational use of fire behaviour models has mostly followed a deterministic approach, however, the uncertainty associated with model predictions needs to be quantified and included in wildfire planning and decision-making process during fire suppression activities. We use FARSITE to simulate the growth of a large wildfire. Probabilistic simulations of fire spread are performed, accounting for the uncertainty of some model inputs and parameters. Deterministic simulations were performed for comparison. We also assess the degree to which fire spread modelling and satellite active fire data can be combined, to forecast fire spread during large wildfires events. Results: Uncertainty was propagated through the FARSITE fire spread modelling system by randomly defining 100 different combinations of the independent input variables and parameters, and running the correspondent fire spread simulations in order to produce fire spread probability maps. Simulations were initialized with the reported ignition location and with satellite active fires. The probabilistic fire spread predictions show great potential to be used as a fire management tool in an operational setting, providing valuable information regarding the spatial–temporal distribution of burn probabilities. The advantage of probabilistic over deterministic simulations is clear when both are compared. Re-initializing simulations with satellite active fires did not improve simulations as expected. Conclusion: This information can be useful to anticipate the growth of wildfires through the landscape with an associated probability of occurrence. The additional information regarding when, where and with what probability the fire might be in the next few hours can ultimately help minimize the negative environmental, social and economic impacts of these firesinfo:eu-repo/semantics/publishedVersio

Ecological implications of fine-scale fire patchiness and severity in tropical savannas of northern Australia

Research ArticleUnderstanding fine-scale fire patchiness has significant implications for ecological processes and biodiversity conservation. It can affect local extinction of and recolonisation by relatively immobile fauna and poorly seed-dispersed flora in fire-affected areas. This study assesses fine-scale fire patchiness and severity, and associated implications for biodiversity, in north Australian tropical savanna systems. We used line transects to sample burning patterns of ground layer vegetation in different seasons and vegetation structure types, within the perimeter of 35 fires that occurred between 2009 and 2011. We evaluated two main fire characteristics: patchiness (patch density and mean patch length) and severity (inferred from char and scorch heights, and char and ash proportions). The mean burned area of ground vegetation was 83 % in the early dry season (EDS: May to July) and 93 % in the late dry season (LDS: August to November). LDS fires were less patchy (smaller and fewer unburned patches), and had higher fire severity (higher mean char and scorch heights, and twice the proportion of ash) than EDS fires. Fire patchiness varied among vegetation types, declining under more open canopy structure. The relationship between burned area and fire severity depended on season, being strongly correlated in the EDS and uncorrelated in the LDS. Simulations performed to understand the implications of patchiness on the population dynamics of fire-interval sensitive plant species showed that small amounts of patchiness substantially enhance survival. Our results indicate that the ecological impacts of high frequency fires on firesensitive regional biodiversity elements are likely to be lower than has been predicted from remotely sensed studies that are based on assumptions of homogeneous burninginfo:eu-repo/semantics/publishedVersio

VE-statin/egfl7 Expression in Endothelial Cells Is Regulated by a Distal Enhancer and a Proximal Promoter under the Direct Control of Erg and GATA-2

Angiogenesis is the process by which new blood vessels arise from existing ones by the budding out of endothelial cell capillaries from the luminal side of blood vessels. Blood vessel formation is essential for organ development during embryogenesis and is associated with several physiological and pathological processes, such as wound healing and tumor development. The VE-statin/egfl7 gene is specifically expressed in endothelial cells during embryonic development and in the adult. We studied here the regulatory mechanisms that control this tissue-specific expression. RT-qPCR analyses showed that the specificity of expression of VE-statin/egfl7 in endothelial cells is not shared with its closest neighbor genes notch1 and agpat2 on the mouse chromosome 2. Chromatin-immunoprecipitation analysis of histone modifications at the VE-statin/egfl7 locus showed that the chromatin is specifically opened in endothelial cells, but not in fibroblasts at the transcription start sites. A 13 kb genomic fragment of promoter was cloned and analyzed by gene reporter assays which showed that two conserved regions are important for the specific expression of VE-statin/egfl7 in endothelial cells; a −8409/−7563 enhancer and the −252/+38 region encompassing the exon-1b transcription start site. The latter contains essential GATA and ETS-binding sites, as assessed by linker-scanning analysis and site-directed mutagenesis. An analysis of expression of the ETS and GATA transcription factors showed that Erg, Fli-1 and GATA-2 are the most highly expressed factors in endothelial cells. Erg and GATA-2 directly control the expression of the endogenous VE-statin/egfl7 while Fli-1 probably exerts an indirect control, as assessed by RNA interference and chromatin immunoprecipitation. This first detailed analysis of the mechanisms that govern the expression of the VE-statin/egfl7 gene in endothelial cells pinpoints the specific importance of ETS and GATA factors in the specific regulation of genes in this cell lineage

Relative contributions of adipose-resident CD146 pericytes and CD34 adventitial progenitor cells in bone tissue engineering

Bone repair: synergistic healing from two types of fat cells Different kinds of cells found surrounding blood vessels in fat play a complementary and synergistic role in bone healing. Aaron James from Johns Hopkins University in Baltimore, MD, USA, and colleagues derived two subsets of cells from human fat tissue: contractile cells known as pericytes that wrap around cellular lining of capillaries and tiny veins; and connective tissue cells known as adventitial cells that surrounds larger vessels. Under isolated culture conditions, pericytes stimulated the development of primitive blood vessels, whereas adventitial cells promoted early bone formation. The researchers applied the cells to the sites of bone defects in mice and saw that combined treatment with both pericytes and adventitial cells led to greater bone repair than treatment with either cell type alone

Alterações dos hábitos alimentares em pacientes submetidos a laringectomia parcial frontolateral e total

CONTEXT: Swallowing is a continuous dynamic process, characterized by complex stages, that involves structures of the oral cavity, pharynx, larynx and esophagus. It can be divided into three phases: oral, pharyngeal and esophageal. Dysphagia is characterized by difficulty with, or the inability to swallow food of normal consistencies. OBJECTIVE: To investigate the presence of swallowing difficulties and modifications made to the consistency of the food consumed in cases of total and partial laryngectomy, with or without subsequent radiotherapy, among patients who had not been diagnosed as having dysphagia. TYPE OF STUDY: Descriptive study. SETTING: Voice Clinic of São Paulo Hospital, Universidade Federal de São Paulo (UNIFESP)/Escola Paulista de Medicina, São Paulo, Brazil. METHOD: 36 laryngectomy patients: 25 total and 11 frontolateral cases, were studied. A survey consisting of a 23-item questionnaire was applied by a single professional. RESULTS: Among those interviewed, 44% reported having modified the consistency of the food consumed (56% of the total and 20% of the partial frontolateral laryngectomy cases). It was not possible to investigate the influence of radiotherapy on the groups in this study, because the partial frontolateral laryngectomy cases were not exposed to radiotherapy. There was a higher incidence of complaints of swallowing difficulties in total laryngectomy cases (p < 0.027) than in partial frontolateral cases. However, there was no relationship between the surgery and weight loss. We also noted the patients' other problems regarding the eating process, as well as the compensation that they made for such problems. DISCUSSION: Research has shown an association between laryngectomy and swallowing difficulties, although there have been no reports of associated changes in eating habits among laryngectomized patients. CONCLUSIONS: This study showed that difficulty in swallowing is not rare in total and frontolateral laryngectomy cases. Such patients, even those who did not complain of dysphagia, also had minor difficulties while eating, and had to make some adaptations to their meals.CONTEXTO: A deglutição é um processo dinâmico e contínuo, caracterizado por etapas complexas, que envolve estruturas da cavidade oral, faringe, laringe e esôfago. Pode ser dividida em fases: oral, faríngea e esofágica. A disfagia é caracterizada por dificuldades ou inabilidade em deglutir alimentos em consistências normais. OBJETIVO: Investigar a presença de dificuldades de deglutição e mudanças nas consistências dos alimentos em pacientes submetidos a laringectomia total e laringectomia parcial vertical frontolateral, seguidos ou não de radioterapia e sem diagnóstico de disfagia. TIPO DE ESTUDO: Descritivo. LOCAL: Ambulatório de Voz do Hospital São Paulo, Universidade Federal de São Paulo (UNIFESP) - Escola Paulista de Medicina, São Paulo, Brazil. MÉTODO: 36 pacientes laringectomizados: 25 submetidos a laringectomia total e 11 a laringectomia parcial frontolateral foram incluídos no estudo. Questionário contendo 23 itens, foi aplicado por uma única profissional. RESULTADOS: Dentre os entrevistados, 44% relataram modificações na consistência dos alimentos durante as refeições; dentre estes 56% eram laringectomizados totais e 20%, laringectomizados parciais frontolaterais. Não foi possível investigar a influência da radioterapia nos grupos deste estudo, pois os pacientes laringectomizados parciais frontolaterais não foram expostos à radioterapia. Houve alta incidência de queixas de dificuldades de deglutição entre os pacientes laringectomizados totais (p < 0,027). Entretanto, não houve associação entre cirurgia realizada e perda de peso. Observamos outras queixas relatadas pelos pacientes durante a alimentação, como problemas e compensações realizadas pelos pacientes. DISCUSSÃO: Pesquisas mostraram associação entre laringectomia e dificuldades de deglutição, porém não foram encontrados estudos associando mudanças de hábitos alimentares em pacientes laringectomizados. CONCLUSÃO: Este estudo mostra que a dificuldade na deglutição não é rara nos pacientes submetidos a laringectomia frontolateral e total. Os pacientes, mesmo aqueles que não apresentaram queixas de disfagia, também tiveram pequenas dificuldades durante a alimentação, fazendo algumas adaptações necessárias.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaUNIFESP, EPMSciEL