499 research outputs found

    Bath's law Derived from the Gutenberg-Richter law and from Aftershock Properties

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    The empirical Bath's law states that the average difference in magnitude between a mainshock and its largest aftershock is 1.2, regardless of the mainshock magnitude. Following Vere-Jones [1969] and Console et al. [2003], we show that the origin of Bath's law is to be found in the selection procedure used to define mainshocks and aftershocks rather than in any difference in the mechanisms controlling the magnitude of the mainshock and of the aftershocks. We use the ETAS model of seismicity, which provides a more realistic model of aftershocks, based on (i) a universal Gutenberg-Richter (GR) law for all earthquakes, and on (ii) the increase of the number of aftershocks with the mainshock magnitude. Using numerical simulations of the ETAS model, we show that this model is in good agreement with Bath's law in a certain range of the model parameters.Comment: major revisions, in press in Geophys. Res. Let

    Interactive effects of social environment, age and sex on immune responses in Drosophila melanogaster

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    Social environments have been shown to have multiple effects on individual immune responses. For example, increased social contact might signal greater infection risk and prompt a prophylactic upregulation of immunity. This differential investment of resources may in part explain why social environments affect ageing and lifespan. Our previous work using Drosophila melanogaster showed that single-sex social contact reduced lifespan for both sexes. Here, we assess how social interactions (isolation or contact) affect susceptibility to infection, phagocytotic activity and expression of a subset of immune and stress related genes in young and old flies of both sexes. Social contact had a neutral, or even improved, effect on post-infection lifespan in older flies and reduced the expression of stress response genes in females, however it reduced phagocytotic activity. Overall the effects of social environment were complex and largely subtle, and do not indicate a consistent effect. Together, these findings indicate that social contact in D. melanogaster does not have a predictable impact on immune responses and does not simply trade-off immune investment with lifespan

    ‘Sons of athelings given to the earth’: Infant Mortality within Anglo-Saxon Mortuary Geography

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    FOR 20 OR MORE YEARS early Anglo-Saxon archaeologists have believed children are underrepresented in the cemetery evidence. They conclude that excavation misses small bones, that previous attitudes to reporting overlook the very young, or that infants and children were buried elsewhere. This is all well and good, but we must be careful of oversimplifying compound social and cultural responses to childhood and infant mortality. Previous approaches have offered methodological quandaries in the face of this under-representation. However, proportionally more infants were placed in large cemeteries and sometimes in specific zones. This trend is statistically significant and is therefore unlikely to result entirely from preservation or excavation problems. Early medieval cemeteries were part of regional mortuary geographies and provided places to stage events that promoted social cohesion across kinship systems extending over tribal territories. This paper argues that patterns in early Anglo-Saxon infant burial were the result of female mobility. Many women probably travelled locally to marry in a union which reinforced existing social networks. For an expectant mother, however, the safest place to give birth was with experience women in her maternal home. Infant identities were affected by personal and legal association with their mother’s parental kindred, so when an infant died in childbirth or months and years later, it was their mother’s identity which dictated burial location. As a result, cemeteries central to tribal identities became places to bury the sons and daughters of a regional tribal aristocracy

    DADOS MÉDICO-LEGAIS SOBRE AFOGAMENTOS NA REGIÃO DE RIBEIRÃO PRETO (SP, BRASIL): UM PASSO PARA A PREVENÇÃO

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    This is a prevalence study with the first specific description of drowning cases in a non-coastal area of Brazil, in the locality of Ribeirão Preto, State of São Paulo—a region with standards of living comparable to those in developed countries—regarding the establishment of preventative measures for this specific kind of injury. Methodology: An analysis of the forensic documentation of 89 drowning cases occurred between 2001 and 2004. The pattern of drowning fatalities was studied in relation to parameters like age, sex, socio-economic background and evaluation of alcohol consumption.Results : rate of 2.69 cases per 100,000 habitants per year was observed. The predominant profile among drowning victims was that of the Caucasian male of economically productive age (15 to 59 years), accidentally drowned in rivers and dams in rural areas during the summer and autumn, being impossible the evaluation of alcohol consumption. Conclusion and Relevance : the observation of the victim profile through the analysis of forensic reports allowed the development of a successful pilot program of drowning prevention that can be expanded to other non-coastal areas in Brazil, regarding the reduction of the number of victims by prevention. The difficulties in alcohol consumption analysis are discussed.Este é um estudo de prevalência com a primeira descrição específica de casos de afogamento em uma área não-costeira do Brasil, em Ribeirão Preto, estado de São Paulo, uma região com padrão de vida comparável ao de países desenvolvidos, com o objetivo de estabelecer medidas preventivas para este tipo específico de trauma. Metodologia : Uma análise da documentação médico-legal de 89 casos de afogamento ocorridos entre 2001 e 2004. O padrão de mortes por afogamento foi estudado através de parâmetros como idade, sexo, características sócio-econômicas e avaliação do consumo de álcool. Resultados: um índice de 2,69 casos por 100.000 habitantes foi observado. O perfil predominante entre as vítimas de afogamento foi o do homem caucasiano em idade economicamente produtiva (15-59 anos), afogados acidentalmente em rios e represas na área rural durante o verão e o outono, sendo inviável a avaliação do consumo de álcool. Conclusão e Relevância : a observação do perfil da vítima de afogamento através dos relatórios médico-legais permitiu o desenvolvimento de um projeto piloto de sucesso na prevenção de afogamentos que pode ser expandido para outras áreas não-costeiras do Brasil, visando à redução do número de vítimas através da prevenção. As dificuldades de investigar a influência do consumo de álcool são discutidas. 

    Randomised trial of indwelling pleural catheters for refractory transudative pleural effusions

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    Objective: Refractory symptomatic transudative pleural effusions are an indication for pleural drainage. There has been supportive observational evidence for the use of indwelling pleural catheters (IPCs) for transudative effusions, but no randomised trials. We aimed to investigate the effect of IPCs on breathlessness in patients with transudative pleural effusions when compared with standard care. / Methods: A multicentre randomised controlled trial, in which patients with transudative pleural effusions were randomly assigned to either an IPC (intervention) or therapeutic thoracentesis (TT; standard care). The primary outcome was mean daily breathlessness score over 12 weeks from randomisation. / Results: 220 patients were screened from April 2015 to August 2019 across 13 centres, with 33 randomised to intervention (IPC) and 35 to standard care (TT). Underlying aetiology was heart failure in 46 patients, liver failure in 16 and renal failure in six. In primary outcome analysis, the mean±sd breathlessness score over the 12-week study period was 39.7±29.4 mm in the IPC group and 45.0±26.1 mm in the TT group (p=0.67). Secondary outcomes analysis demonstrated that mean±sd drainage was 17 412±17 936 mL and 2901±2416 mL in the IPC and TT groups, respectively. A greater proportion of patients had at least one adverse event in the IPC group (p=0.04). / Conclusion: We found no significant difference in breathlessness over 12 weeks between IPCs or TT. TT is associated with fewer complications and IPCs reduced the number of invasive pleural procedures required. Patient preference and circumstances should be considered in selecting the intervention in this cohort

    The DIAMORFOSIS (DIAgnosis and Management Of lung canceR and FibrOSIS) survey: international survey and call for consensus.

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    Background Currently there is major lack of agreement on the diagnostic and therapeutic management of patients with idiopathic pulmonary fibrosis (IPF) and lung cancer. Our aim was to identify variations in diagnostic and management strategies across different institutions and provide rationale for a consensus statement on this issue. Methods This was a joint-survey by European Respiratory Society (ERS) Assemblies 8, 11 and 12. The survey consisted of 25 questions. Results Four hundred and ninety-four (n=494) physicians from 68 different countries and five continents responded to the survey. Ninety-four per cent of participants were pulmonologists, 1.8% thoracic surgeons and 1.9% oncologists; 97.7% were involved in multidisciplinary team approaches on diagnosis and management. Regular low-dose high-resolution computed tomography (HRCT) scan was used by 49.5% of the respondents to screen for lung cancer in IPF. Positron emission tomography (PET) scan and endobronchial ultrasound (EBUS) is performed by 60% and 88% to diagnose nodular lesions with mediastinal lymphadenopathy in patients with advanced and mild IPF, respectively. Eighty-three per cent of respondents continue anti-fibrotics following lung cancer diagnosis; safety precautions during surgical interventions including low tidal volume are applied by 67%. Stereotactic radiotherapy is used to treat patients with advanced IPF (diffusing capacity of the lung for carbon monoxide (DLCO) <35%) and otherwise operable nonsmall cell lung cancer (NSCLC) by 54% of respondents and doublet platinum regimens and immunotherapy for metastatic disease by 25% and 31.9%, respectively. Almost all participants (93%) replied that a consensus statement for the management of these patients is highly warranted. Conclusion The diagnosis and management of IPF-lung cancer (LC) is heterogeneous with most respondents calling for a consensus statement

    How should performance in EBUS mediastinal staging in lung cancer be measured?

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    There has been a paradigm shift in mediastinal staging algorithms in non-small cell lung cancer over the last decade in the United Kingdom (UK). This has seen endoscopic nodal staging (predominantly endobronchial ultrasound, EBUS) almost replace surgical staging (predominantly mediastinoscopy) as the pathological staging procedure of first choic

    Role of thoracic ultrasonography in pleurodesis pathways for malignant pleural effusions (SIMPLE): an open-label, randomised controlled trial

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    BACKGROUND: Pleurodesis is done as an in-patient procedure to control symptomatic recurrent malignant pleural effusion (MPE) and has a success rate of 75-80%. Thoracic ultrasonography has been shown in a small study to predict pleurodesis success early by demonstrating cessation of lung sliding (a normal sign seen in healthy patients, lung sliding indicates normal movement of the lung inside the thorax). We aimed to investigate whether the use of thoracic ultrasonography in pleurodesis pathways could shorten hospital stay in patients with MPE undergoing pleurodesis. METHODS: The Efficacy of Sonographic and Biological Pleurodesis Indicators of Malignant Pleural Effusion (SIMPLE) trial was an open-label, randomised controlled trial done in ten respiratory centres in the UK and one respiratory centre in the Netherlands. Adult patients (aged ≥18 years) with confirmed MPE who required talc pleurodesis via either a chest tube or as poudrage during medical thorascopy were eligible. Patients were randomly assigned (1:1) to thoracic ultrasonography-guided care or standard care via an online platform using a minimisation algorithm. In the intervention group, daily thoracic ultrasonography examination for lung sliding in nine regions was done to derive an adherence score: present (1 point), questionable (2 points), or absent (3 points), with a lowest possible score of 9 (preserved sliding) and a highest possible score of 27 (complete absence of sliding); the chest tube was removed if the score was more than 20. In the standard care group, tube removal was based on daily output volume (per British Thoracic Society Guidelines). The primary outcome was length of hospital stay, and secondary outcomes were pleurodesis failure at 3 months, time to tube removal, all-cause mortality, symptoms and quality-of-life scores, and cost-effectiveness of thoracic ultrasonography-guided care. All outcomes were assessed in the modified intention-to-treat population (patients with missing data excluded), and a non-inferiority analysis of pleurodesis failure was done in the per-protocol population. This trial was registered with ISRCTN, ISRCTN16441661. FINDINGS: Between Dec 31, 2015, and Dec 17, 2019, 778 patients were assessed for eligibility and 313 participants (165 [53%] male) were recruited and randomly assigned to thoracic ultrasonography-guided care (n=159) or standard care (n=154). In the modified intention-to-treat population, the median length of hospital stay was significantly shorter in the intervention group (2 days [IQR 2-4]) than in the standard care group (3 days [2-5]; difference 1 day [95% CI 1-1]; p<0·0001). In the per-protocol analysis, thoracic ultrasonography-guided care was non-inferior to standard care in terms of pleurodesis failure at 3 months, which occurred in 27 (29·7%) of 91 patients in the intervention group versus 34 (31·2%) of 109 patients in the standard care group (risk difference -1·5% [95% CI -10·2% to 7·2%]; non-inferiority margin 15%). Mean time to chest tube removal in the intervention group was 2·4 days (SD 2·5) versus 3·1 days (2·0) in the standard care group (mean difference -0·72 days [95% CI -1·22 to -0·21]; p=0·0057). There were no significant between-group differences in all-cause mortality, symptom scores, or quality-of-life scores, except on the EQ-5D visual analogue scale, which was significantly lower in the standard care group at 3 months. Although costs were similar between the groups, thoracic ultrasonography-guided care was cost-effective compared with standard care. INTERPRETATION: Thoracic ultrasonography-guided care for pleurodesis in patients with MPE results in shorter hospital stay (compared with the British Thoracic Society recommendation for pleurodesis) without reducing the success rate of the procedure at 3 months. The data support consideration of standard use of thoracic ultrasonography in patients undergoing MPE-related pleurodesis. FUNDING: Marie Curie Cancer Care Committee
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