609 research outputs found

    Use of fractal dimensions to quantify coral shape

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    A morphometrical method to quantify and characterize coral corallites using Richardson Plots and Kaye's notion of fractal dimensions is presented. A Jurassic coral species (Aplosmilia spinosa) and five Recent coral species were compared using the Box-Counting Method. This method enables the characterization of their morphologies at calicular and septal levels by their fractal dimensions (structural and textural). Moreover, it is possible to determine differences between species of Montastraea and to tackle the high phenotypic plasticity of Montastraea annularis. The use of fractal dimensions versus conventional methods (e.g., measurements of linear dimensions with a calliper, landmarks, Fourier analyses) to explore a rugged boundary object is discussed. It appears that fractal methods have the potential to considerably simplify the morphometrical and statistical approaches, and be a valuable addition to methods based on Euclidian geometr

    Evidencing the role of plants vs soils in the understanding of 137Cs phyto availability using a coupled experimental and modelling approach

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    International audience137Cs is a radionuclide with a half-life of 30 years that is commonly found in soils after nuclear fallout due to nuclear incidents or atmospheric nuclear weapon testing. Due to their properties of accumulation and retention, soils are key compartments for the transfer of contaminants such as 137Cs in the trophic chain. Ingestion of contaminated agricultural products being one of the main component of human exposure, it is essential to be able to predict the fate of 137Cs throughout the soil-plant continuum.The contaminant mobility into the soil, its transfer to the plant and its final distribution between all components are generally described by simple models (equilibrium-based, linear distributions). These models are operational but are not able to account for the variability of soils and plants encountered.Bioavailability is function of both soil physico-chemical characteristics, that impact the environmental availability, and plant physiology which determines the uptake rate and accumulation. The aim of this work is to highlight the preponderant factors controlling the 137Cs bioavailability in the soil-solution-plant continuum by using a model that account for both soil and plant characteristics. The proposed mechanistic model is based on thermodynamic reactions describing the interactions of Cs with the different soil reactive components, coupled with a physiological model of root absorption.Series of experiments were conducted to produce a contrasted data set of 137Cs soil to plant transfer. For those experiments, 2 different plants with contrasted Cs uptake capacities (Millet, Mustard) and 3 different soils with varying texture and mineralogy have been studied. Three weeks exposure studies were conducted with the RHIZOtest® which is a normative device to assess the bioavailability of contaminants in soil. They were completed with batch experiments aiming at characterizing the environmental availability of Cs in soils. A large range of 137Cs soil to plant transfer rates was measured for the different soil/pant combinations. For example a contrasted bioavailability of 137Cs was observed, with the same plant accumulating 10% to 40% of total Cs’s stock depending on the soils. We also observed that during the time of the experiment the plant had absorbed most of the estimated environmental available Cs.Modelling those experiments allowed us to highlight the main soil and plant properties that have a great impact on the contaminant mobility. For example, plant physiological factors were the main driver of bioavailability in condition where environmental availability was not limited (e.g. sandy soils), whereas their roles were reduced in soils with high 137Cs sorption capacity. Such a model may help to reduce uncertainties in the prediction of 137Cs transfer to plants in environmental risk assessment, with a great potential to cover a large range of soils and plants

    Thermal state of electronic assemblies applied to smart building equipped with QFN64 device subjected to natural convection

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    The performance and reliability of electronic components and assemblies strongly depend on their thermal state. The knowledge of the temperature distribution throughout the assembly is therefore an essential element to ensure their correct operation. This is the main objective of this work that examines the case of a conventional assembly equipped with a quad flat nonlead QFN64 subjected to free convection. This active electronic package is welded on a PCBwhich may be inclined by an angle varying between 0° and 90° (horizontal and vertical positions respectively) and generates during its operation a high power ranging from 0.1 to 1W.Thermoregulation of the assembly is ensured by natural convection, given its many well known advantages in this engineering field. Accurate relationships are proposed to determine the temperature on different areas of the device and the PCB. They are determined by means of a 3D numerical survey based on the finite volume method confirmed by measurements on an actual installation. These relationships allow reliability improvement of these electronicassemblies widely used in many engineering fields, as computing industry, mobile telephony, home automation, automotive, embarked electronics and smart building considered in this survey. The present survey complements a recent study which quantifies the natural convective heat transfer on the considered electronic assembly equipped with the QFN64 device, for thesame power range and angle of inclination

    Enhancement of natural convection for improvement of Trombe wall performance. An experimental study

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    This experimental work shows that the natural convective heat transfer in the active enclosure of a conventional Trombe wall assembly is enhanced by the interposition of transparent and vertical partitions. Quantification of the average Nusselt number corresponding to both versions with and without partitions was carried out by means of a 1/5 scale assembly. The glass cover is maintained isothermal at cold temperature while the active wall generates a variable heat flux simulating the incident solar radiation. The distance between the two active and parallel walls is variable. Four ratios between this distance and the height of the wall are considered, associated with a wide range of Rayleigh number reaching 4.1×109. An error calculation is carried out for all the processed configurations, taking into account the experimental uncertainties of the measured physical parameters. The maximum error found on the average Nusselt number is low, of about 5%. Measurements made by means of an interstitial medium without partitions are consistent with the results of other work carried out by experimental and numerical approaches in specific ranges of Rayleigh number. This study reveals the partitions effectiveness, since the natural convective heat transfer's increase lies between 10.0% and 14.4% according to the considered configuration. Correlations are proposed in the present work in order to calculate the average natural convective Nusselt number for the conventional Trombe wall without partitions and for its improved version, for any aspect ratio and in the whole range of the considered Rayleigh number. They contribute to the optimization of the thermal design of this interesting assembly

    Impact of comprehensive geriatric assessment on survival, function, and nutritional status in elderly patients with head and neck cancer: protocol for a multicentre randomised controlled trial (EGeSOR)

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    BACKGROUND: Survival is poorer in elderly patients with head and neck squamous cell carcinomas [HNSCCs] than in younger patients. Possible explanations include a contribution of co-morbidities to mortality, frequent refusal of standard therapy, and the use of suboptimal treatments due to concern about toxicities. The Comprehensive Geriatric Assessment [CGA] is a multidimensional assessment of general health that can help to customise treatment and follow-up plans. The CGA has been proven effective in several health settings but has not been evaluated in randomised studies of patients with cancer. Our aim here was to assess the impact of the CGA on overall survival, function, and nutritional status of elderly patients with HNSCC. METHODS/DESIGN: EGeSOR is an open-label, multicentre, randomised, controlled, parallel-group trial in patients aged 70 years or older and receiving standard care for HNSCC. The intervention includes four components: the CGA conducted by a geriatrician before cancer treatment, participation of the same geriatrician in cancer treatment selection, a standardised geriatric therapeutic intervention designed by the same geriatrician; and geriatric follow-up for 24 months. The primary endpoint, assessed after 6 months, is a composite criterion including death, functional impairment [Activities of Daily Living score decrease ≥2], and weight loss ≥10%. Secondary endpoints include progression-free survival, unscheduled admissions, quality of life, treatment toxicities, costs, and completion of the planned cancer treatment. A centralised online system is used to perform 1:1 randomisation with a minimisation algorithm for centre, age, T and N stages, and tumour site [oral, oropharyngeal, hypopharyngeal, or laryngeal]. The estimated sample size is 704 patients, who are being recruited by 14 centres in 9 French cities. DISCUSSION: EGeSOR is the first randomised trial of the CGA in elderly cancer patients. We expect the CGA to have direct clinical benefits on the management of elderly patients with HNSCC. If this expectation is fulfilled, the trial may lead to modifications of the management model for elderly patients with cancer. TRIAL REGISTRATION: Trial registration: NCT0202506

    Toxic Epidermal Necrolysis after Pemetrexed and Cisplatin for Non-Small Cell Lung Cancer in a Patient with Sharp Syndrome

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    Background: Pemetrexed is an antifolate drug approved for maintenance and second-line therapy, and, in combination with cisplatin, for first-line treatment of advanced nonsquamous non-small cell lung cancer. The side-effect profile includes fatigue, hematological and gastrointestinal toxicity, an increase in hepatic enzymes, sensory neuropathy, and pulmonary and cutaneous toxicity in various degrees. Case Report: We present the case of a 58-year-old woman with history of Sharp's syndrome and adenocarcinoma of the lung, who developed toxic epidermal necrolysis after the first cycle of pemetrexed, including erythema, bullae, extensive skin denudation, subsequent systemic inflammation and severe deterioration in general condition. The generalized skin lesions occurred primarily in the previous radiation field and responded to immunosuppressive treatment with prednisone. Conclusion: Although skin toxicity is a well-known side effect of pemetrexed, severe skin reactions after pemetrexed administration are rare. Caution should be applied in cases in which pemetrexed is given subsequent to radiation therapy, especially in patients with pre-existing skin diseases

    Clinical Impact of Electronic Monitoring Devices of Inhalers in Adults with Asthma or COPD: A Systematic Review and Meta-Analysis

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    We conducted a systematic review and meta-analysis to gain insight into the characteristics and clinical impact of electronic monitoring devices of inhalers (EMDs) and their clinical interventions in adult patients with asthma or COPD. The search included PubMed, Web of Science, Cochrane, Scopus and Embase databases, as well as official EMDs websites. We found eight observational studies and ten clinical trials, assessing a wide range of clinical outcomes. Results from the meta-analysis on adherence to inhalers in a period over three months were favourable in the EMD group (fixed effects model: SMD: 0.36 [0.25-0.48]; random effects model SMD: 0.41 [0.22-0.60]). An exploratory meta-analysis found an improvement in ACT score (fixed effect model SMD: 0.25 [0.11-0.39]; random effects model: SMD: 0.47 [−0.14-1.08]). Other clinical outcomes showed mixed results in the descriptive analyses. The findings of this review highlight the benefits of EMDs in the optimization of adherence to inhaled therapy as well as the potential interest in other clinical outcomes

    Cholesteatoma of the external ear canal: etiological factors, symptoms and clinical findings in a series of 48 cases

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    BACKGROUND: To evaluate symptoms, clinical findings, and etiological factors in external ear canal cholesteatoma (EECC). METHOD: Retrospective evaluation of clinical records of all consecutive patients with EECC in the period 1979 to 2005 in a tertiary referral centre. Main outcome measures were incidence rates, classification according to causes, symptoms, extensions in the ear canal including adjacent structures, and possible etiological factors. RESULTS: Forty-five patients were identified with 48 EECC. Overall incidence rate was 0.30 cases per year per 100,000 inhabitants. Twenty-five cases were primary, while 23 cases were secondary: postoperative (n = 9), postinflammatory (n = 5), postirradiatory (n = 7), and posttraumatic (n = 2). Primary EECC showed a right/left ratio of 12/13 and presented with otalgia (n = 15), itching (n = 5), occlusion (n = 4), hearing loss (n = 3), fullness (n = 2), and otorrhea (n = 1). Similar symptoms were found in secondary EECC, but less pronounced. In total the temporomandibular joint was exposed in 11 cases, while the mastoid and middle ear was invaded in six and three cases, respectively. In one primary case the facial nerve was exposed and in a posttraumatic case the atticus and antrum were invaded. In primary EECC 48% of cases reported mechanical trauma. CONCLUSION: EECC is a rare condition with inconsistent and silent symptoms, whereas the extent of destruction may be pronounced. Otalgia was the predominant symptom and often related to extension into nearby structures. Whereas the aetiology of secondary EECC can be explained, the origin of primary EECC remains uncertain; smoking and minor trauma of the ear canal may predispose

    Factors associated with active aging in Finland, Poland, and Spain

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    ABSTRACT Background: Continuous population aging has raised international policy interest in promoting active aging (AA). AA theoretical models have been defined from a biomedical or a psychosocial perspective. These models may be expanded including components suggested by lay individuals. This paper aims to study the correlates of AA in three European countries, namely, Spain, Poland, and Finland using four different definitions of AA. Methods: The EU COURAGE in Europe project was a cross-sectional general adult population survey conducted in a representative sample of the noninstitutionalized population of Finland, Poland, and Spain. Participants (10,800) lived in the community. This analysis focuses on individuals aged 50 years old and over (7,987). Four definitions (two biomedical, one psychosocial, and a complete definition including biomedical, psychosocial, and external variables) of AA were analyzed. Results: Differences in AA were found for country, age, education, and occupation. Finland scored consistently the highest in AA followed by Spain and Poland. Younger age was associated with higher AA. Higher education and occupation was associated with AA. Being married or cohabiting was associated with better AA compared to being widowed or separated in most definitions. Gender and urbanicity were not associated with AA, with few exceptions. Men scored higher in AA only in Spain, whereas there was no gender association in the other two countries. Being widowed was only associated with lower AA in Poland and not being married was associated with lower AA in Poland and Finland but not Spain. Conclusions: Associations with education, marital status, and occupation suggest that these factors are the most important components of AA. These association patterns, however, seem to vary across the three countries. Actions to promote AA in these countries may be addressed at reducing inequalities in occupation and education or directly tackling the components of AA lacking in each countr
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