Le comportement d'un système hydrologique en climat méditerranéen par l'analyse corrélatoire et spectrale des débits et des pluies. Cas de trois sous bassins sud-méditerranéens : (oued Sebdou, Moulah et Isser - Tafna - NW Algérie)

Les analyses corrélatoire et spectrale des chroniques de la pluie (entrée) et de débits (sortie) journaliers enregistrés au niveau des trois bassins sud méditerranéens Sebdou, Mouilah et Isser durant un seul cycle hydrologique nous ont permis d’obtenir des informations sur le fonctionnement de ces systèmes hydrologiques. Bien que la structure du signal « pluie » semble présenter les mêmes caractéristiques pour les trois bassins, le signal de sortie « débit » indique que l’oued Sebdou réagit différemment par rapport aux oueds Mouilah et Isser.The aim of this work was to show that correlation and spectral analyses can be used to understand the functioning of hydrological systems. Accordingly, a study was carried out on three southern Mediterranean basins: Sebdou; Mouilah and Isser; located in the north western of Algeria. (Figure 1). Correlation and spectral analyses of daily rainfall and discharge rates for one hydrological cycle were carried out.Simple analysisSimple analysis of rainfall showed that the correlograms (Figure 2) decreased rapidly for the three basins, reaching a value of 0.2 within 1-2 days. This result indicated that rainfall was a quasi-random phenomenon. The variance density spectrum (Figure 3) showed that the rainfall distribution was not monotonous and presented a “Leigh” signal structure.The simple analysis of discharge rates indicated that the Sebdou system was different. The correlogram (Figure 4a) decreased quickly, characterising independent events without memory and with non-significant amounts of water. However, the Mouilah and Isser correlograms (Figure 4 b,c) decreased slowly. They represent important memory effects with regulation of significant amounts of water. The spectral band (Figure 5) confirmed that the Sebdou system did not modify the input information. The regulation time was about 5 d for Sebdou, 21 and 43 d respectively for Mouilah and Isser.Cross analysisThe correlograms (Figure 6) show that the Mouilah and Isser rivers have a great buffering ability. The Sebdou River was characterised by a composite response of the surface flow and an important groundwater flow. The amplitude function (Figure 7) indicated that the Sebdou system had good inertia. The lag time (Figure 8) was 9, 2 and 5 days respectively for the Sebdou, Mouilah and Isser rivers. The amplification and attenuation of the input signal (Figure 10) show that the Sebdou basin is the most karstified system. The non-linearity of the relationship between rainfall and discharge was expressed by the coherence coefficient (Figure 9), which was lower than 1

Passivity voltage based control of the boost power converter used in photovoltaic system

Introduction. This paper presents a robust nonlinear control of the DC-DC boost converter feeding by a photovoltaic system based on the passivity control. The control law design uses the passivity approach. Novelty. The novelty consists in designing a control law for a photovoltaic system using a passivity approach based on energy shaping and associated with damping injection. Purpose. The purpose consists to develop a tool for design and optimize a control law of the photovoltaic system in order to improve its efficiency under some conditions such as the variations of the temperature, the irradiation and the parameters. Also, the control law design should be simple with a lower overshoot and a shorter settling time. Methods. This work uses the port Hamiltonian mathematical approach with minimization of the energy dissipation in boost converter of the photovoltaic system to illustrate the modification of energy and generate a specify duty cycle applied to the converter. Results. The results with MATLAB/SimPowerToolbox® have proven the robustness against parameter variations and effectiveness of the proposed control. Practical value. The experimental results, carried out using a dSPACE DS1104 system, are presented to show the feasibility and the robustness of the proposed control strategy against parameter variations.Вступ. У статті представлено надійне нелінійне керування живленням перетворювача постійного струму, що підвищує, фотоелектричною системою на основі керування пасивністю. У створенні закону управління використовується пасивний підхід. Новизна. Новизна полягає у розробці закону управління фотоелектричною системою з використанням пасивного підходу, заснованого на формуванні енергії та пов'язаного з упорскуванням демпфування. Мета. Мета полягає в тому, щоб розробити інструмент для проектування та оптимізації закону керування фотогальванічною системою для підвищення її ефективності за деяких умов, таких як зміни температури, опромінення та параметрів. Крім того, будова закону управління має бути простою, з меншим перерегулюванням і коротшим часом встановлення. Методи. У роботі використовується математичний підхід Гамільтона до порту з мінімізацією розсіювання енергії у перетворювачі фотоелектричної системи, що підвищує, щоб проілюструвати зміну енергії і створити заданий робочий цикл, що застосовується до перетворювача. Результати. Результати з використанням MATLAB/SimPowerToolbox® довели стійкість до змін параметрів та ефективність запропонованого керування. Практична цінність. Представлені експериментальні результати, отримані з використанням системи dSPACE DS1104, щоб показати здійсненність та стійкість запропонованої стратегії управління при  зміні параметрів

ESSAI DE LUTTE BIOLOGIQUE CONTRE LA PYRALE DES DATTES Apomyelois ceratoniae ZELLER, 1839 (LEPIDOPTERA : PYRALIDAE) PAR L’UTILISATION DE Phanerotomaflavitestacea FISHER (HYMENOPTERA : BRACONIDAE) ET Bracon hebetor SAY (HYMENOPTERA : BRACONIDAE) DANS LES CO

Notre étude porte sur des tes de lutte biologique à partir du cortège parasitaire autochtone de la pyrale des dattes (Apomyelois =Ectomyelois ceratoniae Zeller, 1839). Nous avons testé deux principaux auxilliares :Phanerotomaflavitestacea Fisher et Bracon hebetor Say.Les résultats obtenus montrent qu’il y a un effet significatif de l’action parasitaire des deux espèces étudiées sur le cycle biologique de la pyrale des dattes. Nous avons mesuré un taux de 58,50 dû au Phanerotoma et  100 % pour Bracon. La technique combinant l’utilisation des deux axillaires semble être une piste permettant de limiter la détérioration de la valeur marchande des dattes

EFFET DE LA THERMO-DESINSECTISATION SUR LES DIFFERENTS STADES LARVAIRES DE LA PYRALE DES DATTES ECTOMYELOIS CERATONIAE DANS LES CONDITIONS CONTROLEES

Notre étude porte sur le testde l’efficacité du traitement thermique comme alternative au traitement chimique pour lutter contre les œufs et des larves de la pyrale de datte dans les lieux du stockage et du conditionnement des dattes. L'emploi des produits chimiques de synthèse, aux conséquences, sans aucun doute, contrariantes pour la santé humaine, l’environnement en général, sur l’entomofaune utile et en particulier lors des exportations vers d’autres pays de l’Europe, de l’Amérique, le Canada et de l’Asie.  Les températures utilisées sont 50, 53, 58 et 60°C,  avec des durées respectives 7mn, 15mn et 30mn. Nos résultats montrent que les œufs et les jeunes larves sont les stades les plus sensibles à la chaleur, on a constaté aussi que la température de 58°C pendant une durée de 15mn est suffisante pour une mortalité de 100% de tous les stades de développement d’Ectomyelois ceratoniae et que la durée d’exposition joue un rôle très important pour tuer le ravageur. Ce résultat prometteur répond aux normes de l’exportation de dattes

Hemodynamic Modeling of the Intrarenal Circulation

Three dimensional, time dependent numerical simulations of healthy and pathological conditions in a model kidney were performed. Blood flow in a kidney is not commonly investigated by computational approach, in contrast for example, to the flow in a heart. The flow in a kidney is characterized by relatively small Reynolds number (100<Re<0.01—laminar regime). The presented results give insight into the structure of such flow, which is hard to measure in vivo. The simulations have suggested that venous thrombosis is more likely than arterial thrombosis—higher shear rate observed. The obtained maximum velocity, as a result of the simulations, agrees with the observed in vivo measurements. The time dependent simulations show separation regimes present in the vicinity of the maximum pressure value. The pathological constriction introduced to the arterial geometry leads to the changes in separation structures. The constriction of a single vessel affects flow in the whole kidney. Pathology results in different flow rate values in healthy and affected branches, as well as, different pulsate cycle characteristic for the whole syste

Thyroid Dysfunction and Anemia: A Prospective Cohort Study and a Systematic Review.

Even though the association between thyroid dysfunction and anemia is commonly described, it is not known whether it is clinically relevant. This study set out to quantify the association of thyroid dysfunction on hemoglobin (Hb) concentration and risk of anemia. A systematic review (MEDLINE and EMBASE, from inception until May 15, 2017) was conducted to interpret the findings in context. Participants from the EPIC-Norfolk cohort with available baseline thyrotropin (TSH), free thyroxine (fT4), and Hb were included. Euthyroidism was defined as TSH 0.45-4.49 mIU/L (reference category), hypothyroidism as TSH ≥4.50 mIU/L (subclinical [SHypo] with normal fT4 or overt [OHypo] with low fT4), and hyperthyroidism as TSH ≤0.44 mIU/L (subclinical [SHyper] with normal fT4 or overt [OHyper] with elevated fT4). Anemia was defined as Hb &lt;12 g/dL in women and Hb &lt;13 g/dL in men. In the cross-sectional analyses, multiple linear regression was used to compare Hb across TSH categories. In the prospective analysis, participants with OHypo/OHyper at baseline were excluded, as it was assumed that they were treated for overt thyroid disease. A covariance model was used to determine change in Hb concentration from baseline to last follow-up, and multivariable Cox regression was used to analyze anemia risk. In the cross-sectional population (n = 12,337), the adjusted Hb was 0.22 g/dL lower [confidence interval (CI) 0.07-0.38] in OHypo compared to euthyroids, and 0.08 g/dL lower [CI -0.23 to 0.38] in OHyper. In the prospective analysis, 460/7031 participants developed anemia over a median follow-up of 4.7 years. The adjusted mean Hb change over time was -0.04 g/dL in SHypo [CI -0.14 to 0.06] and 0.05 g/dL in SHyper [CI -0.10 to 0.20]. The adjusted hazard ratio for anemia was 0.99 [CI 0.67-1.48] in SHypo, and 0.52 [CI 0.23-1.16] in SHyper. The systematic review returned no other prospective studies on this association, but cross-sectional and case-control studies showed comparable results. In this first prospective population-based cohort, subclinical thyroid dysfunction was not associated with a change in Hb concentration during follow-up and was not an independent risk factor for developing anemia; variations in Hb concentration in patients with overt thyroid dysfunction were not clinically relevant

Thyroid dysfunction and anaemia in a large population-based study.

OBJECTIVE AND BACKGROUND: Anaemia and thyroid dysfunction are common and often co-occur. Current guidelines recommend the assessment of thyroid function in the work-up of anaemia, although evidence on this association is scarce. PATIENTS AND METHODS: In the 'European Prospective Investigation of Cancer' (EPIC)-Norfolk population-based cohort, we aimed to examine the prevalence and type of anaemia (defined as haemoglobin &lt;13 g/dl for men and &lt;12 g/dl for women) according to different thyroid function groups. RESULTS: The mean age of the 8791 participants was 59·4 (SD 9·1) years and 55·2% were women. Thyroid dysfunction was present in 437 (5·0%) and anaemia in 517 (5·9%) participants. After excluding 121 participants with three most common causes of anaemia (chronic kidney disease, inflammation, iron deficiency), anaemia was found in 4·7% of euthyroid participants. Compared with the euthyroid group, the prevalence of anaemia was significantly higher in overt hyperthyroidism (14·6%, P &lt; 0·01), higher with borderline significance in overt hypothyroidism (7·7%, P = 0·05) and not increased in subclinical thyroid dysfunction (5·0% in subclinical hypothyroidism, 3·3% in subclinical hyperthyroidism). Anaemia associated with thyroid dysfunction was mainly normocytic (94·0%), and rarely macrocytic (6·0%). CONCLUSION: The prevalence of anaemia was higher in overt hyperthyroidism, but not increased in subclinical thyroid dysfunction. Systematic measurement of thyroid-stimulating hormone in anaemic patients is likely to be useful only after excluding common causes of anaemia

Qui meurt après une néphrectomie pour cancer ? Étude des facteurs de risque de décès, des causes de décès et des réunions de morbi-mortalité (étude UroCCR-33)

BACKGROUND AND METHODS: Nephrectomy is the treatment for renal cell cancer from T1-4 tumors but remains at risk. To determine the thirty-day mortality rate after nephrectomy for cancer and to identify causes and risk factors of death in order to find clinical applications. From 2014 to 2017, we performed a retrospective multicentric analysis of prospectively collected data study involving the French network for research on kidney cancer (UroCCR). All patients who died after nephrectomy for cancer during the first thirty days were identified. Patients\u27 characteristics, causes of death and morbidity and mortality reviews reports were analyzed for each death. RESULTS AND LIMITATIONS: In total, 2578 patients underwent nephrectomy and 35 deaths occurred. The thirty-day mortality rate was 1.4%. In univariate analysis, symptoms at diagnosis (P=0.006, OR=2.56 IC (1.3-5.03)), c stage superior to cT1 (P&lt;0.0001, OR=6.13 IC (2.8-13.2)), cT stage superior to cT2 (P&lt;0.0001, OR=8.8 IC (4.39-17.8)), nodal invasion (P&lt;0.0001, OR=4.6 IC (1.9-10.7)), distant metastasis (P=0.001, OR=4.01 IC (1.7-8.9)), open surgery (P&lt;0.0001, OR=0.272 IC (0.13-0.54)) and radical nephrectomy (P=0.007, OR=2.737 IC (1.3-5.7)) were risk factors of thirty-day mortality. In a multivariable model, only cT stage superior to T2 (P=0.015, OR=3.55 IC (1.27-10.01)) was a risk factor of thirty-day mortality. The main cause of postoperative death was pulmonary (n=15; 43%). The second cause was postoperative digestive sepsis for 7 patients (20%). Only 2 morbidity and mortality reviews had been done for the 35 deaths. Limitations are related to the thirty-day mortality criteria and descriptive study design. CONCLUSIONS: Symptomatic patients, stage cTNM and type and techniques of surgery are determinants of thirty-day mortality after nephrectomy for cancer. The first cause of postoperative death is pulmonary. Morbidity and mortality reviews should be considered to better understand causes of death and to reduce early mortality after nephrectomy for cancer. LEVEL OF EVIDENCE: 4

Promising role of preoperative neutrophil-to-lymphocyte ratio in patients treated with radical nephroureterectomy.

Several retrospective studies with small cohorts reported neutrophil-to-lymphocyte ratio (NLR) as a prognostic marker in upper tract urothelial carcinoma (UTUC) following radical nephroureterectomy (RNU). We aimed at validating the predictive and prognostic role of NLR in a large multi-institutional cohort. Preoperative NLR was assessed in a multi-institutional cohort of 2477 patients with UTUC treated with RNU. Altered NLR was defined by a ratio &gt;2.7. Logistic regression analyses were performed to assess the association between NLR and lymph node metastasis, muscle-invasive and non-organ-confined disease. The association of altered NLR with recurrence-free survival (RFS) and cancer-specific survival (CSS) was evaluated using Cox proportional hazards regression models. Altered NLR was observed in 1428 (62.8 %) patients and associated with more advanced pathological tumor stage, lymph node metastasis, lymphovascular invasion, tumor necrosis and sessile tumor architecture. In a preoperative model that included age, gender, tumor location and architecture, NLR was an independent predictive factor for the presence of lymph node metastasis, muscle-invasive and non-organ-confined disease (p &lt; 0.001). Within a median follow-up of 40 months (IQR 20-76 months), 548 (24.1 %) patients experienced disease recurrence and 453 patients (19.9 %) died from their cancer. Compared to patients with normal NLR, those with altered NLR had worse RFS (0.003) and CSS (p = 0.002). In multivariable analyses that adjusted for the effects of standard clinicopathologic features, altered NLR did not retain an independent value. In the subgroup of patients treated with lymphadenectomy in addition to RNU, NLR was independently associated with CSS (p = 0.03). In UTUC, preoperative NLR is associated with adverse clinicopathologic features and independently predicts features of biologically and clinically aggressive UTUC such as lymph node metastasis, muscle-invasive or non-organ-confined status. NLR may help better risk stratify patients with regard to lymphadenectomy and conservative therapy