Influence of EBR on the structural resistance of RC slabs under quasi-static and blast loading: Experimental testing and numerical analysis

Flexural strengthening of reinforced concrete (RC) structures with externally bonded reinforcement (EBR) using carbon fibre-reinforced polymers (CFRP) has in recent years received increased interest from specialists, particularly when dealing with protective structures against terrorist or accidental blast loading. Although a significant number of studies have been conducted on the failure modes of the bonded interface for quasi -static conditions, there is still limited published research on the effects of blast loading. In this paper, RC slabs externally strengthened with CFRP are tested in three-point bending as well as subjected to blast loading. The behaviour of the tested specimens under both loading regimes is evaluated with special focus on the mechanisms that lead to the disruption of the CFRP. It was found that the debonding of the CFRP was caused, in both cases, by the fracture and separation of a thin layer of concrete in the near vicinity of the bonded interface. However, the mechanisms that lead to this failure differ. A numerical model was developed and simulations performed using the finite element (FE) code LS-DYNA to investigate the validity of commonly used simplifications on the modelling of the interface in both cases. It was found that although the modelling technique used to represent the disruption of CFRP under quasi-static conditions provide accurate results, it does not return accurate predictions of the debonding of CFRP under blast loading

Genetic, serological and biochemical characterization of Leishmania tropica from foci in northern Palestine and discovery of zymodeme MON-307

Background Many cases of cutaneous leishmaniasis (CL) have been recorded in the Jenin District based on their clinical appearance. Here, their parasites have been characterized in depth. Methods Leishmanial parasites isolated from 12 human cases of CL from the Jenin District were cultured as promastigotes, whose DNA was extracted. The ITS1 sequence and the 7SL RNA gene were analysed as was the kinetoplast minicircle DNA (kDNA) sequence. Excreted factor (EF) serotyping and multilocus enzyme electrophoresis (MLEE) were also applied. Results This extensive characterization identified the strains as Leishmania tropica of two very distinct sub-types that parallel the two sub-groups discerned by multilocus microsatellite typing (MLMT) done previously. A high degree of congruity was displayed among the results generated by the different analytical methods that had examined various cellular components and exposed intra-specific heterogeneity among the 12 strains. Three of the ten strains subjected to MLEE constituted a new zymodeme, zymodeme MON-307, and seven belonged to the known zymodeme MON-137. Ten of the 15 enzymes in the profile of zymodeme MON-307 displayed different electrophoretic mobilities compared with the enzyme profile of the zymodeme MON-137. The closest profile to that of zymodeme MON-307 was that of the zymodeme MON-76 known from Syria. Strains of the zymodeme MON-307 were EF sub-serotype A2 and those of the zymodeme MON-137 were either A9 or A9B4. The sub-serotype B4 component appears, so far, to be unique to some strains of L. tropica of zymodeme MON-137. Strains of the zymodeme MON-137 displayed a distinctive fragment of 417 bp that was absent in those of zymodeme MON-307 when their kDNA was digested with the endonuclease RsaI. kDNA-RFLP after digestion with the endonuclease MboI facilitated a further level of differentiation that partially coincided with the geographical distribution of the human cases from which the strains came. Conclusions The Palestinian strains that were assigned to different genetic groups differed in their MLEE profiles and their EF types. A new zymodeme, zymodeme MON-307 was discovered that seems to be unique to the northern part of the Palestinian West Bank. What seemed to be a straight forward classical situation of L. tropica causing anthroponotic CL in the Jenin District might be a more complex situation, owing to the presence of two separate sub-types of L. tropica that, possibly, indicates two separate transmission cycles involving two separate types of phlebotomine sand fly vector

The Regulation of Ion Homeostasis, Growth, and Biomass Allocation in Date Palm Ex Vitro Plants Depends on the Level of Water Salinity

The date palm, a central plant in the fragile oasis ecosystem, is considered one of the fruit species most tolerant to salt stress. However, the tolerance mechanisms involved are yet to be addressed and their evaluation until now was mainly based on heterogenous plant material such as seedlings or limited to in vitro experiment conditions. For these reasons, we propose to deepen our knowledge of the morphological and physiological responses to salt stress using acclimated ex vitro plants resulting from the propagation of a single genotype. The plants were irrigated with 0, 150, 300, or 450 mM NaCl solutions for four months. Our results showed that the influence of water salinity on growth and ion-homeostasis regulation was very dependent on stress levels. The 150 mM NaCl concentration was found to improve dry biomass by about 35%, but at higher salt concentrations (300 and 450 mM) it decreased by 40–65%. The shoot:root dry mass ratio decreased significantly at the 150 mM NaCl water concentration and then increased with increasing water salt concentration. The leaf:root ratio for Na+ and Cl− decreased significantly with increasing water salinity up to a concentration of 300 mM NaCl, and then stabilized with similar values for 300 mM and 450 mM NaCl. In contrast to Na+ and Cl−, leaf K+ content was significantly higher in the leaf than in the root for all salt treatments. Unlike Na+ and K+, Cl− was expelled to the surface of leaves in response to increased water salinity. Overall, date palm plants appear to be more capable of excluding Cl− than Na+ and of changing biomass allocation according to salt-stress level, and their leaves and roots both appear to play an important role in this tolerance strategy.All authors are funded through the Small Research group project from the Deanship of Scientific Research at King Khalid University under research grant number (R.G.P.1/295/43).Peer reviewe

Giant primary adrenal hydatid cyst presenting with arterial hypertension: a case report and review of the literature

<p>Abstract</p> <p>Introduction</p> <p>A primary hydatid cyst of the adrenal gland is still an exceptional localization. The adrenal gland is an uncommon site even in Morocco, where echinococcal disease is endemic.</p> <p>Case presentation</p> <p>We report the case of a 64-year-old Moroccan man who presented with the unusual symptom of arterial hypertension associated with left flank pain. Computed tomography showed a cystic mass of his left adrenal gland with daughter cysts filing the lesion (Type III). Despite his negative serology tests, the diagnosis of a hydatid cyst was confirmed on surgical examination. Our patient underwent surgical excision of his left adrenal gland with normalization of blood pressure. No recurrence has occurred after 36 months of follow-up.</p> <p>Conclusion</p> <p>There are two remarkable characteristics of this case report; the first is the unusual location of the cyst, the second is the association of an adrenal hydatid cyst with arterial hypertension, which has rarely been reported in the literature.</p

Un nouveau variant enzymatique de

Pour la première fois, l’agent pathogène de la leishmaniose cutanée du Nord de l’Algérie est rapporté à Leishmania infantum s.l. Il s’agit d’un variant enzymatique original (zymodème 24) différant pour deux électromorphes du variant isolé en France (zymodème 11), dans le même type de lésion. Jusqu’à ce jour, les zymodèmes dermotropes d’Algérie et de France n’ont pas été observés dans la leishmaniose viscérale méditerranéenne

Load-Displacement Assessment of One-Way Reinforced Concrete (RC) Slabs Externally Strengthened Using CFRP Strips under Blast Loads

Dynamic behaviour of Reinforced Concrete (RC) structures can be assessed using a Single-Degree-of-Freedom (SDOF) approach. Such a method is highly dependent on the resistance curve of the structure which is generally represented by a bilinear elasto-perfectly-plastic approximation. This approximation might lead to erroneous results when it refers to the use of externally bonded Fibre Reinforced composites for flexural capacity upgrade of Reinforced Concrete (RC), mainly when the concrete-to-FRP interface failure is to be included. One-way slabs are experimentally and numerically investigated in this study in a 3-point flexural configuration. Assessment on the load-displacement behaviour of a reference specimen and its retrofitted counterpart is performed. Special attention is given to the behaviour of the structure after the concrete-to-FRP failure. Comparison is made between experimental and numerical results and a good agreement is obtained. A complementary analytical study based on the SDOF method is conducted to understand the influence of several resistance curves on the overall displacement of the same structure when subjected to different pressure-impulse combinations

Signification du polymorphisme enzymatique chez les leishmanies

L’analyse isoenzymatique de 49 souches de Leishmanies [35 Leishmania infantum Nicolle, 1908, 10 Leishmania cf. tarentolae Wenyon, 1921, 2 Leishmania tropica (Wright, 1903) et 2 Leishmania æthiopica Bray, Ashford et Bray, 1973] a révélé l’existence de structures hétérozygotes pour trois d’entre elles. Sur huit systèmes enzymatiques éprouvés : (PGM, PGI, G-6-PDH, 6-PGDH, IDH, MDH, ME et GOT), trois d’entre eux se sont exprimés par deux (PGM) ou trois (PGI et 6-PGDH) taches sur les gels d’électrophorèse. Une souche de L. infantum (Chien, Cévennes) et une souche de L. cf. tarentolae [Sergentomyia minuta (Rondani, 1843)] étaient hétérozygotes pour la PGI. Une souche de L. æthiopica (Homme, Ethiopie) était hétérozygote pour la PGI, la PGM et la 6-PGDH. Les images observées, comparables à celles obtenues avec les organismes eucaryotes à reproduction sexuée, permettent de suspecter, chez les Leishmanies, l’existence de structures diploïdes et de processus d’échanges génétiques

Application de la méthode numérique à la taxonomie du genre

Les auteurs utilisent les caractères enzymatiques, obtenus par électrophorèse en gel d’amidon, pour tenter une application de la taxonomie numérique à l’analyse systématique du genre Leishmania Ross, 1903. Pour ce faire, huit systèmes enzymatiques (PGI, ME, PGM, GOT, G-6-PDH, 6-PGDH, MDH et IDH) sont éprouvés sur 146 souches originaires de l’Ancien Monde. 35 électromorphes, correspondant à autant d’isoenzymes, permettent d’individualiser 14 zymodèmes. Ces zymodèmes sont assimilés à des Unités Taxonomiques Opérationnelles (UTO) et comparés deux à deux, à l’aide de l’indice de similarité de Jaccard. L’établissement de ces indices permet de bâtir une matrice d’association à partir de laquelle est élaboré le système taxonomique proprement dit. Le phénogramme, réalisé selon la méthode agglomérative, constitue l’expression finale de l’opération. Sa construction utilise la technique dite à liens complets. L’objectivité du découpage en phénons est confirmée par l’analyse des correspondances. En définitive, les souches se répartissent en cinq groupes correspondant aux complexes Leishmania donovani, Leishmania tropica, Leishmania major, Leishmania æthiopica et cf. Leishmania tarentolae. Les phénons individualisés par la taxonomie numérique s’identifient donc aux taxons de la systématique traditionnelle. La signification phylétique des unités individualisées est ensuite apportée par l’approche génétique. Il est en effet possible d’appliquer l’indice de distance de Nei, à condition de ramener les fréquences allozymiques à 0, 0,5 et 1. Le dendrogramme ainsi obtenu est identique au phénogramme : Leishmania major constitue un taxon homogène, individualisé depuis longtemps des autres groupes. Les complexes Leishmania donovani et Leishmania tropica ont conservé des liens non négligeables, témoignant d’une origine commune et d’une divergence évolutive plus récente

Écologie des Leishmanioses dans le sud de la France

Poursuivant l’analyse structurale du foyer cévenol de leishmaniose viscérale, les auteurs procèdent à l’étude enzymatique de 47 souches isolées de cas humains (7 enfants, 7 adultes) et canins (33). Huit systèmes, liés au cycle respiratoire, sont éprouvés selon la technique de l’électrophorèse en gel d’amidon : PGM (E.C.2.7.5.1) ; PGI (E.C.5.3.1.9) ; G-6-PDH (E.C.1.1.1.49) ; 6-PGDH (E.C.1.1.1,44) ; IDH (E,C, 1.1.1.42) ; MDH (E.C.1.1.1.37) ; ME (E.C.1.1.1.40) ; GOT (E.C.2.6,1.1), Les zymogrammes obtenus sont semblables pour la totalité des échantillons. Une souche, isolée d’un cas de leishmaniose cutanéo-muqueuse, entre également dans ce groupe. En outre, aucune différence n’est constatée entre les échantillons cévenols et ceux provenant de souches viscérales canines d’origine niçoise, corse et tunisienne. De même, s’avère identique le zymogramme d’une souche isolée d’une leishmaniose viscérale du Honduras (Leishmania chagasi Cunha et Chagas, 1937). Par contre, une divergence est notée avec les zymodèmes correspondant aux formes viscérales indiennes et irakiennes (2 systèmes/8). Les arguments en faveur de l’individualité et de l’homogénéité du « macrofoyer » zoonotique méditerranéen se trouvent ainsi renforcés. Dès lors, pour ce foyer, le binôme Leishmania infantum Nicolle, 1908 est recommandé à la place de Leishmania donovani (Laveran et Mesnil, 1903), pour nommer le parasite responsable des formes viscérales, tant humaines que canines, et de certaines formes muqueuses humaines. Par voie de conséquence, Leishmania chagasi deviendrait synonyme de Leishmania infantum