Objectives Our main goal is to improve, from theoretical point of view, the mechanistic understanding of bone buckling failure which is known as at the core of important clinical problems such as osteoporosis. Material and methods What is well argued is that in older bone, stability-initiated failure dominates because of the instability of the individual trabeculae which is prone to inelastic buckling at stresses far less than expected for strength-based failure. Taking advantage of our previous work, an improved original Euler’s adaptive-beam buckling equation incorporating density gradient effect is investigated. Results For one, we indicate that resorption can leads to new elastic instabilities that can conduct to bone-buckling mechanism of fracture. For another, we demonstrate that bone density gradient play a key role in the initiation of the bone-column elastic buckling instability. Conclusion As a result, it is clearly stated here that firstly, the number of these elastic instabilities which are potentially implied in the mechanisms of bone fracture, localized at the trabecular element scale, depends strongly upon the material parameter η and secondly; the bone density gradient affect notably the stability of the bone-column deflection.  

Introduction: Chronic lymphocytic leukemia (CLL) is the most frequent leukemia of the adult in Europe and North Africa. It is rare on the Asian and African continents. It affects mainly elderly people over 60 years. The main objective is determining the rate of average annual incidence, and secondly establishing the distribution of this complaint according to the different health regions of the country and precise the epidemiological characteristics. Patients and Methods: It is a national, descriptive, retrospective epidemiological study carried out for a period of 05 years : from January 2009 to December 2013. Information collection is done thanks to the setting up of a technical data sheet sent out to the appropriate services. This technical data sheet is about the geographic data of the patient (place of birth, place of residence, place of taking charge of the disease and the date of the diagnosis), anthropologic data (age at the diagnosis, sex), as well as the clinico-biological data. The working of the responses was done on SPSS 19 .0. In our study, the diagnosis is carried before an hyperlymphocytosis > 5000/ mm3, a cytological examination of the blood smear and an immunophenotyping operation by cytometer operation in flow. Results: 17 hematology departments have participated in this study with 1210 cases listed, of which 68,1% (824 pts) are men. The average annual recruitment is of 242 cases. The average annual incidence rate, calculated according to the data of the national statistics office is estimated at 0,66 / 100.000 inhabitants.This incidence does not increase over the years and stays relatively stable (2009 = 0,67; 2010 = 0,57; 2011 = 0,63; 2012 = 0,67; 2013 = 0,74/100.000 inhts). The geographic distribution of the pts according to their places of residence, shows that the majority among them are from the north of the country particularly the center (0,80/100.000 inhts). Incidence increases over age, going among men from 0,06 for 100.000 inhts between 30 - 39 years to 11,94 / 100.000 inhts at 80 years and over and among women from 0,04 for 100.000 inhts to 6,08 for 100.000 inhts. The average incidence rate is of 0,85/100.000 inhts among men and of 0,42/100.000 inhts among women. The average age at the diagnosis is of 67,5 years (33 - 98 years). 30,1% (365 pts) incident cases are observed among the patients over 75 years and 14,1% (171 pts) among the patients below the age of 55 years. The profession that is most found is farming 12.2% (78/635 precised). The diagnosis is late in Algeria, the first symptome which brings the patient to consultation is the tumoral syndrome (44% (363 / 825 precised)) in an average diagnosis period of time of 07 months (01 - 96 months). The stage C (classification of Binet) is equally predominant, found in 41,1% (492 / 1172 precised). In terms of biology : the average rate of lymphocytes is of 92500/mm3 (5000-900 000/mm3). The morphological study on blood smear finds 88,2% (1066 / 1208 precised) of typical CLL and 50% of Gambrest cells. The cytometer operation in flow done in 746 cases (61,6%) shows a score of matutes > 4 in 92,3% and in 7,7% is equal to 3. the cytogenetic operation (Caryotype and Fish) done in only one hematology department (CAC of Blida) among 102 patients (8.4%). Comments: The rate of incidence in Algeria is weak compared to that of other countries. The rate of incidence standardized to the world population is of 0,52 cases/100.000 inhts and to the European population is of 0,68 cases p 100.000 inhts. The young age of the population may explain this incidence and that some patients at the stage A are not diagnosed. The CLL affects more frequently men. The average age at the diagnosis is of 67,5 year. However, 30,1% of the incident cases are observed among the patients over 75 years in Algeria versus 45 à 50% of incident cases in Europe and this may be explained by the young age of our population. The CLL are placed 5th among the malignant hemopathies: the rate of incidence for the year 2009 : LNH = 1.96; LH = 1.2; MM = 0.96; AML = 0.85; CLL = 0.67; CML = 0.44; ALL = 0.32. Conclusion: the CLL can be diagnosed and differentiated from the other lymphoproliferative syndromes thanks to the morphological examination of the lymphocytes at the blood smear completed by an immunophenotyping operation of the peripheral blood . This study represents only an epidemiological approach of the CLL in Algeria. The incidence is still weak in our country; it affects as in the other countries the elderly people with a masculin predominance. Disclosures No relevant conflicts of interest to declare.

The goal of fertilization is to meet the nutritional needs of plants by completing the supply of soil nutrients in an economically profitable and environmentally friendly. Achieving on-farm optimum economic crop yields of marketable quality with minimum adverse environmental impact requires close attention to fertilization guide. The recommendations seek to do this by ensuring that the available supply of plant nutrients in soil is judiciously supplemented by additions of nutrients in fertilizers. The objective is that crops must have an adequate supply of nutrients, and many crops show large and very profitable increases in yield from the correct use of fertilizers to supply nutrients. The main objective of this work is to establishing a reference guide of fertilization of vegetable crops and cereal in Algeria. To meet this objective, we have processes in two steps: 1) Establishment of theoretical fertilizer recommendation from international guide of crop fertilization; 2) Validation of these developed theoretical fertilizer recommendation by trials in the fields. Sixteen fertilization guides of vegetable crops from the Canadian provinces (5 guides), USA (10 guides) and countries of northern Europe England (1 guide). Generally, the rating of these recommendation is ranging from poor soil to soil exceedingly rich; however, the numbers of fertility classes are very different. Indeed, Quebec Ontario, Minnesota, Wisconsin New England, Maryland and Kentucky and Florida guides are subdivided into 5 fertility classes, ranging from poor soil to soil exceedingly rich. The recommendation of New Brunswick and Manitoba contain six classes. The recommendation of Michigan, Nova Scotia and England contain 10 and 7 fertility classes respectively. The recommendation fertilizer of New York and New Jersey have 3classes. Unlike the systems of fertilization recommendation mentioned above, the recommendation fertilizer of Pennsylvania is based on continuous models of P, K and contains 34 classes for P and 22 classes K. Then we standardized the P soil analysis with conversion equations (Olsen method) and units of measurement (kg/ha, mg/kg…).Following this procedure we transformed discontinued systems of fertility classes in to continuous models to facilitate comparison between the different fertilization recommendation models in one hand, in other hand to obtain critical value (CV).Finally, we used statistics of the conditional expectation in order to generate the theoretical recommendation fertilization guide of fertilization with 7 fertility classes (VL, L, M, MH, OP, H and VH). The next step was calibrating soil tests against yield responses to applied nutrient in field experiments. A database (not published data) from agriculture and agri-food Canada, were used. Production of pumpkin responded positively and significantly to P or K soil fertility levels, increases being observed with P more often than with K. According to the Cate-Nelson methods, the critical value of Olsen-P in the top 20 cm of soil was about 25 mg/kg: at values of greater than or equal to 25 mg/kg, crops achieved about 80% of their maximal yield in the absence of fertilizer application. The CV of K in soil for this crop was about 140 mg/kg. The CV found was very close to this generated by the theoretical method for recommendation of fertilization guide. Finally, we used the procedure of Cope and Rouse in both sides of the CV in order to make subdivisions of different groups of soil fertility. One calibrates the soil-test value against yield response to tile nutrient to predict fertilizer requirement.

Le SASS couvre une superficie d’environ 1000000 km², ilest partagé parl’Algérie, la Libye et la Tunisie. Il est situé dans une zone hyper aride avec unerecharge actuelle minime mais un grand volume stocké, évalué entre 20000 et31000 km3.Depuis 1970 à nos jours, l’exploitation du SASS est passée de 0,6 àplus de2,5milliards m3/an., d’oùdesrisques majeursdesalinisation des eaux,deréduction de l’artésianisme,detarissement des exutoires naturels,debaisse dela piézométrie,d’augmentation des rabattements oud’interférencesdespérimètres de captageentre pays...Ce qui menace à terme la durabilité dudéveloppement socio-économique engagé dans l’ensemble de la zone.Pour parer aumieux à ces risques et surtout pour mieux s’enprémunir, unprocessus de coopération a été initiédepuis 1998sous l’égide de l’observatoiredu Sahara septentrional(OSS)en partenariat avec les institutions en charge desressources en eau dans les 3 pays.L’importance de cet immense réservoir pour le développement de la zone SASSet la nécessité de sa gestion durable et concertée a amené à une entente pour sonétude enplusieurs phases: la caractérisation hydrogéologique du systèmeaquifère et sa modélisation, l’identification des risques environnementaux etl’inclusion de l’aspect socio-économique dans des scénarios de développement.Les ressources en eau du SASS sont très faiblement renouvelables,environ1milliard dem3/an, vis-à-vis des prélèvements actuels estimés à 2,5 milliards dem3/an. La prise en compte de cette donnéea été déterminante pour pousser lesscientifiques à établir la meilleure modélisation conceptuelle possible dusystème qui soit à même de permettre d’envisager différents scénariosd’exploitation de la ressource tout en tenant compte des perspectives de développement socio-économique de chacun des 3 pays.Les données actuelles, quoique rassurantes, ne signifient pas l’inexistence, àcourt ou moyen terme, d’un risque de conflit autour de ces eauxtransfrontalières. En effet, le problème mérite d’être analysé à travers plusieursindicateurs qui ont un impact sur ce risque.L’objectif de cette note est d’évaluer le risque de conflit autour des eaux duSASS à travers un indice global exprimé numériquement sur la base de lacombinaison de poids et de cotes de plusieurs indicateurs qui ont, directementou indirectement, un impact sur le risque de conflit.L’indice global de risque de conflit obtenu pour le cas du SASS semble reflétercorrectement la situation quiyprévaut actuellement.La comparaison de cerésultat avec ceux obtenus pour les eaux transfrontalières du bassin du Jourdain(risque élevé) et ceux du système aquifère du Guarani (risque faible), confortel’échelle des valeurs adoptée dans cette méthode d’indexation numérique.

  In this paper we are concerned with the exit time problem of a dynamic system perturbed by a white noise, in the case where the noiseless dynamics has a global attractor in a given domain. By the use of a singular perturbation technique and recent results on the asymptotic expansion of a class of Laplace-type integrals, new results concerning the problem under investigation will be presented.  

Safety Instrumented Systems (SIS) constitute an indispensable element in the process of risk reduction for almost all of nowadays’ industrial facilities. The main purpose of this paper is to develop a set of generalized and simplified analytical expressions for two commonly employed metrics to assess the performance of SIS in terms of safety integrity, namely: the Average Probability of Failure on Demand (PFDavg) and the Probability of Dangerous Failure per Hour (PFH). In addition to the capability to treat any K-out-of-N architecture, the proposed formulas can smoothly take into account the contributions of Partial Stroke Testing (PST) and Common Cause Failures (CCF). The validity of the suggested analytical expressions is ensured through various comparisons that are carried out at different stages of their construction.