Mathematical and Numerical Analysis of a Class of Non-linear Elliptic Equations in the Two Dimensional Case

8 pagesThe aim of this paper is to show the existence and present a numerical analysis of weak solutions for a quasi-linear elliptic problem with Dirichlet boundary conditions in a domain $\Omega$ and data belonging to $L^1(\Omega)$. A numerical algorithm to compute a numerical approximation of the weak solution is described and analyzed. Numerical examples are presented and commented

First Investigation of the Composition and Spatial Distribution of Polychaete Feeding Guilds from Essaouira Protected Coastal area (Atlantic Coast of Morocco)

Several researches have been conducted to explain patterns of the abundance, richness and taxonomic diversity of benthic polychaetes; however, such analyses have ignored the functional diversity of polychaete communities, especially feeding guilds in intertidal rocky shores. The present study was carried out to describe and analyse the polychaete feeding guilds on intertidal rocky shores and then examine the effects of environmental factors. Twelve intertidal rocky shores from the coastal protected area of Essaouira (Atlantic coast of Morocco) were sampled during the summer of 2016. A total of 42 polychaete species belonging to 29 genera and 16 families were identified among the 4517 specimens collected. The medium biomass per sampling site was found to be 37.61 ± 15.80 g.m-2 . The polychaete species were classified into five feeding guilds, and nine feeding modes. The filter feeders were the dominant feeding guild (32%) followed by omnivores (23%), burrowers (20%), carnivorous (15%) and surface deposit-feeders (10%). The FDT (filter feeder, discretely motile, with tentacles) was the most abundant feeding mode, accounting for 24% of abundance (mainly represented by Sabellaria alveolata), followed by the ODJ feeding mode (omnivorous, discretely motile, with jaw apparatus) with 22%, and the SDT feeding mode (surface deposit feeder, discretely motile, with tentacles) with 18.9%. The highest trophic importance index and index of trophic diversity values were recorded in the southern region of Essaouira coastline. Based on the canonical correspondence analysis, composition and spatial distribution of polychaete feeding guilds were mainly related to the length of rocky shores and water temperature

First inappropriate implantable cardioverter defibrillator therapy is often due to inaccurate device programming: analysis of the French OPERA registry

AIMS:Inappropriate therapy delivered by implantable cardioverter defibrillators (ICDs) remains a challenge. The OPERA registry measured the times to, and studied the determinants of, first appropriate (FAT) and inappropriate (FIT) therapies delivered by single-, dual- and triple-chamber [cardiac resynchronization therapy defibrillator (CRT-D)] ICD. METHODS AND RESULTS: We entered 636 patients (mean age = 62.0 ± 13.5 years; 88% men) in the registry, of whom 251 received single-, 238 dual-, and 147 triple-chamber ICD, for primary (30.5%) or secondary (69.5%) indications. We measured times to FAT and FIT as a function of multiple clinical characteristics, examined the effects of various algorithm components on the likelihood of FAT and FIT delivery, and searched for predictors of FAT and FIT. Over 22.8 ± 8.8 months of observation, 184 patients (28.9%) received FAT and 70 (11.0%) received FIT. Ventricular tachycardia (VT) was the trigger of 88% of FAT, and supraventricular tachycardia was the trigger of 91% of FIT. The median times to FIT (90 days; range 49-258) and FAT (171 days; 50-363) were similar. The rate of FAT was higher (P <0.001) in patients treated for secondary than primary indications, while that of FIT were similar in both groups. Out of 57 analysable FIT, 27 (47.4%) could have been prevented by fine tuning the device programming like the sustained rate duration or the VT discrimination algorithm. CONCLUSIONS: First inappropriate therapy occurred in 11% of 636 ICD recipients followed for ∼2 years. Nearly 50% of FIT could have been prevented by improving device programming

Contribution des isotopes de l’environnement pour la comprehension du fonctionnement de l’aquifere mio-plioquaternaire du Haouz de Marrakech (Maroc)

The study area «Haouz plain» is Located at the center of Morocco, it extend on a surface of 2800 km2, limited by the Jbilet hills in the North, the High-Atlas range in the South, R' dat wadi in the East and the Essaouira-Chichaoua plateau in the West. The area climate is semi-arid, characterized by low precipitations varying between 160 mm/year and 250mm/year and important variation in temperature between the winter and the summer with respectively 5°C and 45°C. Its hydrographic network is represented by the Tensift system which receives all the affluents of central and Westem Haouz. These affluents are characterized by weak flows with important seasonal variations. The Haouz plain is a sedimentary basin, being along the northern edge of the high atlas, it presents a geologic succession going from the primary to the recent Quaternary. The mio-plioquatemary formations, stemming from the dismantling of the atlasic chain, refuge an important and generalized water table on al1 the plain. This water table shows very variable hydrodynarnic characteristics, reflecting the complexity of the deep structures of the plain, 1986) and also the lithological variability of the mio-plioquatemary formations. The Haouz plain includes also the deep resemoirs of the Jurassic, Cretaceous and Eocene which finish some meters at the north of the Atlas, thus having a very limited extension and thereafter a low productivity. Five representative samples of water taken on the haouz water table were analyzed by the ABHT, the projection of these contents on the potability diagram enabled us to show that water of the water table generally has a good quality to passable. In the east quality becomes poor related to the existence of a zone arranged for agriculture (piezometer 1903/44). The nastiest potability is obsemed on the piezometer 3828/44 located at north of Marrakech at elazouzia zone of spreading of wom water of this city. The representation of the percentages of anions and major cations shows the prevalence of ions Ca2+ and HCO; and makes it possible to show up the Bicarbonate calcic facies of the water table. During these last decades, the use of stable isotopes, such oxygen 18 and deuterium, became necessary for the study of subsoil waters, it makes possible the estimation of the surfaces of refills, the determination of water origin. The samples taken on water points well distributed in the area of study allowed us a better comprehension of the function of the plioquatemary water table. The relation oxygen 18, deuterium shows that water is aligned on a line of slope 8.09, slightly different from the world meteoric line, thus characterizing precipitations of oceanic origin which did not endure notable isotopic fractionation therefore not important evaporation. Using the isotopic measures for the sarnples taken in January 2002 on wells well distributed in the area of study, allows us to show a variation of the contents of 018 with the altitude of the zones of refill. Thus we could delimit the surfaces of refill between 1500 and 800meters height. The relation oxygen-18 deuterium (δ2H = 8,9032 δ18O + 14,214 (R2 = 0,7449 ) translated an Atlantic mode of precipitations without remarkable evaporation.Parmi les aquifères régionaux importants de très grande extension au Maroc, celui du Haouz qui s’étend sur une superficie de 6.000 km2, circule au niveau du remplissage mioplioquaternaire issue du démantèlement de la chaîne Atlasique. Ce dernier présente un faciès constitué de galets, graviers, argiles, marnes et calcaires, dont la puissance atteint les 100 mètres. Cet aquifère joue un rôle très important dans l’alimentation en eau potable des habitants de la plaine du Haouz d’une population de plus de 4 millions d’habitants, en sus d’un complément a l’irrigation de 80.000 ha. Le climat aride de type continental, qui y règne se caractérise par des amplitudes thermiques assez importantes entre l’hiver et l’été. La pluviométrie présente une moyenne de 250 mm par an. La piézométrie de la zone étudiée est caractérisée par un écoulement général du sud vers le nord ouest en direction de l’oued Tensift, également principal collecteur des eaux de surface de la région. Une campagne de mesures isotopiques de plus d’une vingtaine d’échantillons prélevés en janvier 2002 au niveau de puits bien répartis dans la zone d’étude, au pu montrer une variation des teneurs en O" avec l’altitude des zones de recharge. En outre, la relation oxygene-18 deutérium (δ2H = 8,9032 δ18O + 14,214 (R2 = 0,7449 traduit un régime atlantique des précipitations, sans évaporation, ce qui implique que la recharge se fait rapidement, probablement a travers les formations miocènes gréseuses largement fissurées a l’affleurement de l’aquifère mío-plioquatemaire. Un gradient altitudinal moyen de -0,26 ‰ par 100 mètres est déterminé pour la plaine du Haouz, très proche des autres valeurs trouvées pour d’autres régions au Maroc, confirmant la validité régionale de celui-ci. Les variations des teneurs en oxygene-18 peuvent être interprétées en termes de différence d’altitude entre les altitudes de recharge et d’émergence

Impact of renal impairment on atrial fibrillation: ESC-EHRA EORP-AF Long-Term General Registry

Background: Atrial fibrillation (AF) and renal impairment share a bidirectional relationship with important pathophysiological interactions. We evaluated the impact of renal impairment in a contemporary cohort of patients with AF. Methods: We utilised the ESC-EHRA EORP-AF Long-Term General Registry. Outcomes were analysed according to renal function by CKD-EPI equation. The primary endpoint was a composite of thromboembolism, major bleeding, acute coronary syndrome and all-cause death. Secondary endpoints were each of these separately including ischaemic stroke, haemorrhagic event, intracranial haemorrhage, cardiovascular death and hospital admission. Results: A total of 9306 patients were included. The distribution of patients with no, mild, moderate and severe renal impairment at baseline were 16.9%, 49.3%, 30% and 3.8%, respectively. AF patients with impaired renal function were older, more likely to be females, had worse cardiac imaging parameters and multiple comorbidities. Among patients with an indication for anticoagulation, prescription of these agents was reduced in those with severe renal impairment, p <.001. Over 24 months, impaired renal function was associated with significantly greater incidence of the primary composite outcome and all secondary outcomes. Multivariable Cox regression analysis demonstrated an inverse relationship between eGFR and the primary outcome (HR 1.07 [95% CI, 1.01–1.14] per 10 ml/min/1.73 m2 decrease), that was most notable in patients with eGFR <30 ml/min/1.73 m2 (HR 2.21 [95% CI, 1.23–3.99] compared to eGFR ≥90 ml/min/1.73 m2). Conclusion: A significant proportion of patients with AF suffer from concomitant renal impairment which impacts their overall management. Furthermore, renal impairment is an independent predictor of major adverse events including thromboembolism, major bleeding, acute coronary syndrome and all-cause death in patients with AF

Clinical complexity and impact of the ABC (Atrial fibrillation Better Care) pathway in patients with atrial fibrillation: a report from the ESC-EHRA EURObservational Research Programme in AF General Long-Term Registry

Background: Clinical complexity is increasingly prevalent among patients with atrial fibrillation (AF). The ‘Atrial fibrillation Better Care’ (ABC) pathway approach has been proposed to streamline a more holistic and integrated approach to AF care; however, there are limited data on its usefulness among clinically complex patients. We aim to determine the impact of ABC pathway in a contemporary cohort of clinically complex AF patients. Methods: From the ESC-EHRA EORP-AF General Long-Term Registry, we analysed clinically complex AF patients, defined as the presence of frailty, multimorbidity and/or polypharmacy. A K-medoids cluster analysis was performed to identify different groups of clinical complexity. The impact of an ABC-adherent approach on major outcomes was analysed through Cox-regression analyses and delay of event (DoE) analyses. Results: Among 9966 AF patients included, 8289 (83.1%) were clinically complex. Adherence to the ABC pathway in the clinically complex group reduced the risk of all-cause death (adjusted HR [aHR]: 0.72, 95%CI 0.58–0.91), major adverse cardiovascular events (MACEs; aHR: 0.68, 95%CI 0.52–0.87) and composite outcome (aHR: 0.70, 95%CI: 0.58–0.85). Adherence to the ABC pathway was associated with a significant reduction in the risk of death (aHR: 0.74, 95%CI 0.56–0.98) and composite outcome (aHR: 0.76, 95%CI 0.60–0.96) also in the high-complexity cluster; similar trends were observed for MACEs. In DoE analyses, an ABC-adherent approach resulted in significant gains in event-free survival for all the outcomes investigated in clinically complex patients. Based on absolute risk reduction at 1 year of follow-up, the number needed to treat for ABC pathway adherence was 24 for all-cause death, 31 for MACEs and 20 for the composite outcome. Conclusions: An ABC-adherent approach reduces the risk of major outcomes in clinically complex AF patients. Ensuring adherence to the ABC pathway is essential to improve clinical outcomes among clinically complex AF patients

Impact of clinical phenotypes on management and outcomes in European atrial fibrillation patients: a report from the ESC-EHRA EURObservational Research Programme in AF (EORP-AF) General Long-Term Registry

Background: Epidemiological studies in atrial fibrillation (AF) illustrate that clinical complexity increase the risk of major adverse outcomes. We aimed to describe European AF patients\u2019 clinical phenotypes and analyse the differential clinical course. Methods: We performed a hierarchical cluster analysis based on Ward\u2019s Method and Squared Euclidean Distance using 22 clinical binary variables, identifying the optimal number of clusters. We investigated differences in clinical management, use of healthcare resources and outcomes in a cohort of European AF patients from a Europe-wide observational registry. Results: A total of 9363 were available for this analysis. We identified three clusters: Cluster 1 (n = 3634; 38.8%) characterized by older patients and prevalent non-cardiac comorbidities; Cluster 2 (n = 2774; 29.6%) characterized by younger patients with low prevalence of comorbidities; Cluster 3 (n = 2955;31.6%) characterized by patients\u2019 prevalent cardiovascular risk factors/comorbidities. Over a mean follow-up of 22.5 months, Cluster 3 had the highest rate of cardiovascular events, all-cause death, and the composite outcome (combining the previous two) compared to Cluster 1 and Cluster 2 (all P <.001). An adjusted Cox regression showed that compared to Cluster 2, Cluster 3 (hazard ratio (HR) 2.87, 95% confidence interval (CI) 2.27\u20133.62; HR 3.42, 95%CI 2.72\u20134.31; HR 2.79, 95%CI 2.32\u20133.35), and Cluster 1 (HR 1.88, 95%CI 1.48\u20132.38; HR 2.50, 95%CI 1.98\u20133.15; HR 2.09, 95%CI 1.74\u20132.51) reported a higher risk for the three outcomes respectively. Conclusions: In European AF patients, three main clusters were identified, differentiated by differential presence of comorbidities. Both non-cardiac and cardiac comorbidities clusters were found to be associated with an increased risk of major adverse outcomes