Modified bisection algorithm in estimating the extreme value index under random censoring

The Generalized Pareto Distribution (GPD) has long been employed in the theories of extreme values. In this paper, we are interested by estimating the extreme value index under censoring. Using a maximum likelihood estimator (MLE) and a numerical method algorithm, a new approach is proposed to estimate the extreme value index by maximizing the adaptive log-likelihood of GPD given censored data. We also show how to construct the maximum likelihood estimate of the GPD parameters (shape and scale) using censored data. Lastly, numerical examples are provided at the end of the paper to show the method’s reliability and to better illustrate the findings of this research.Publisher's Versio

Secondary organising pneumonia caused by denosumab

Introduction: Organising pneumonia belongs to diffuse interstitial lung diseases; we distinguish the cryptogenic organising pneumonia, which is idiopathic, from the secondary organising pneumonia caused by drugs or a defined cause. Denosumab is a human monoclonal antibody, rarely inducing adverse pulmonary effects. Case description: A 57-year-old female patient was admitted to our chest clinic for acute respiratory distress. She was treated with denosumab for severe osteoporosis. The patient described a dry cough and dyspnoea over the previous four months, increased after the last injection of denosumab. A high-resolution computed tomography scan showed bilateral basal parenchymal condensations. The aetiological investigation did not reveal any infectious or immunological origin. The favourable computed tomography imaging and clinical evolution after corticosteroid therapy led to the diagnosis of drug-induced organising pneumonia. Conclusion: Denosumab could induce organising pneumonia. Therefore, clinicians should be aware of this pulmonary toxicity

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

A comprehensive review of thermoelectric generators: technologies and common applications

Power costs increasing, environmental pollution and global warming are issues that we are dealing with in the present time. To reduce their effects, scientists are focusing on improving energy harvesting-based power generators. Thermoelectric generators (TEGs) have demonstrated their ability to directly convert thermal energy into an electrical one via the Seebeck effect. Also, they are environmentally friendly because they do not contain chemical products, they operate silently because they do not have mechanical structures and/or moving parts, and they can be fabricated on many types of substrates like silicon, polymers, and ceramics. Furthermore, TEGs are position-independent, present a long operating lifetime and are suitable for integration into bulk and flexible devices. This paper presents in-depth analysis of TEGs, starting by an extensive description of their working principle, types (planar, vertical and mixed), used materials, figure of merit, improvement techniques including different thermoelectric materials arrangement (conventional, segmented and cascaded), and used technologies and substrates types (silicon, ceramics and polymers). This manuscript also describes the exploitation of TEGs in various fields starting from low-power applications (medical and wearable devices, IoT: internet of things, and WSN: wireless sensor network) to high-power applications (industrial electronics, automotive engines, and aerospace)

Coalition Game for Video Content Clustering in Content Delivery Networks

International audience—Game theory is a powerful tool that has recently been used in networks to improve the end users' quality of experience (e.g. decreased response time, higher delivery rate). In this paper, we propose to use game theory in the context of Content Delivery Networks (CDNs) to organize video contents into clusters having similar request profiles. The popularity of each content in the cluster can be determined from the popularity of the representative of the cluster and used to store the most popular contents close to end users. A group of experts and a decision-maker predict the popularity of the representative of the cluster. This considerably reduces the number of experts used. More precisely, we model the clustering problem as a hedonic coalition formation game where each coalition represents a cluster. The coalition game converges to a stable partition representing a solution of the problem considered. We compare the results of this approach with the clustering obtained by the K-means algorithm. We evaluate the impact of the content profile observation window considered to establish the clustering. We also evaluate the complexity of the proposed algorithm. Simulation results are obtained on traces of a real CDN. Finally, we extend the proposed approach to model an on-line clustering reflecting the CDN dynamics in terms of proposed contents and contents solicitations

Acoustical Surface Characterization of PP/OWF Composite Plates

International audiencePolypropylene polymer (PP) combined with olive wood flour (OWF) reinforcement is studied in view to find an optimum of viscoelastic properties. The flour ratio content is varied from 0 to 30% and its influence is characterized in terms of surface homogeneity and in terms of acoustic impedance. This acoustical surface property is closely related to the wavelength and active area of the used transducer if it is a plane one. In case of a focused transducer, the wavelength is also a key parameter as well as the so-called f-number which is the ratio between focal distance and active diameter. The focal spot size is thus the surface from which the average acoustical impedance property can be evaluated. The effective wave velocity is deduced from time-of-flight measurements and combined with the average acoustical impedance in order to deduce the effective surface averaged density. As a result, some C-scans of specular echoes obtained for a given PP/OWF composition are compared as a function of the center frequency. The distribution of these acoustical surface properties is compared and discussed for various compositions, depending on the chosen transducer. The influence of the surface roughness is also discussed as an influencing parameter. The analysis of those experimental results constitutes a tool for the improvement of the fabrication process

Combining top-down and bottom-up approaches for building detection in a single very high resolution satellite image

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Moisture content in PP/OWF composite plates monitored using ultrasound

International audienceThis work explores a wood-polymer composite (WPC) made of a polypropylene (PP) polymer combined with olive wood flour (OWF). The longitudinal wave propagation is proposed as an evaluation mean of the WPC viscoelastic properties. Depending on the OWF ratio content, varied from 0 to 30%, the flour dispersion is evaluated in a scanned zone in view to assess the assumption of homogeneity of such WPC plates. In addition, the moisture content can be indirectly highlighted, due to the immersion of the plate in water during its analysis using ultrasound. This effect was measured and evaluated as a function of the immersion time. For those ultrasound measurements, a transducer having a center frequency of 15 MHz and focusing at 54.7 mm in water was used. Indeed, scans were performed over a zone of 100×100 mm 2 and reflection echoes were recorded for each (x, y) position, with a 0.1 mm step. Then, the measurement of the amplitude of the specular echo, combined with the time of flight gives an estimate of the moisture content in the plate. The resulting evaluation of the moisture content is analyzed using a Fick diffusion law. The resolution of the resulting information is also discussed as a function of the transducer properties versus those of the WPC plate