Identification and Quantification of the Most Abondant Hemocytes in the Pine Processionary Caterpillar; ThaumetopoeaPityocampa (Notodontidae)

Abstract Thaumetopoeapityocampa is an important pine pest in the Mediterranean basin and central Europe. The insecte is a butterfly, whose larvae are called pine processionary caterpillars. To understand the resistance mechanism of the insect in order to proceed of its control and to diminuate their effect in nature, it was necessary to study of the immune system and reactions of the larva in different stages. The aim of our work is to identify the hemocytes formula of the caterpillar during the larval stages L2, L3, and L4, as well as the quantification of the different cells during each stage. After extraction of the hemolymph by centrifugation, the cells were placed in culture medium and then incubated. Microscopic observation has shown that prohemocytes population appear early in hemolymph, they differentiate into plasmatocytes and granulocytes during the advanced stages. However, the quantification process (THC), carried out in a Malassez counting chamber has shown that granulocytes are the most abundant cell population in the hemolymph of the insect larvae. To investigate the role of hemocytes in immune responses, we have co-incubate T. pityocampa cells with bacteria, entomopathogenic nematodes, and synthetic beads. Both humoral and cellular encapsulation processes have been observed early in larval stages, all hemocytes seem to be involved in the formation of nodules and capsules against bacteria and microbeads. At the opposite, entomopathogenic nematodes (Steinernemafeltiae) were not recognized and encapsulated, but their presence can strongly damage host hemocytes

Effect of Cu and Sn promotion on the catalytic deoxygenation of model and algal lipids to fuel-like hydrocarbons over supported Ni catalysts

The ability of Cu and Sn to promote the performance of a 20% Ni/Al2O3 catalyst in the deoxygenation of lipids to fuel-like hydrocarbons was investigated using model triglyceride and fatty acid feeds, as well as algal lipids. In the semi-batch deoxygenation of tristearin at 260 °C a pronounced promotional effect was observed, a 20% Ni-5% Cu/Al2O3 catalyst affording both higher conversion (97%) and selectivity to C10-C17 alkanes (99%) in comparison with unpromoted 20% Ni/Al2O3 (27% conversion and 87% selectivity to C10-C17). In the same reaction at 350 °C, a 20% Ni-1% Sn/Al2O3 catalyst afforded the best results, giving yields of C10-C17 and C17 of 97% and 55%, respectively, which contrasts with the corresponding values of 87 and 21% obtained over 20% Ni/Al2O3. Equally encouraging results were obtained in the semi-batch deoxygenation of stearic acid at 300 °C, in which the 20% Ni-5% Cu/Al2O3 catalyst afforded the highest yields of C10-C17 and C17. Experiments were also conducted at 260 °C in a fixed bed reactor using triolein − a model unsaturated triglyceride − as the feed. While both 20% Ni/Al2O3 and 20% Ni-5% Cu/Al2O3 achieved quantitative yields of diesel-like hydrocarbons at all reaction times sampled, the Cu-promoted catalyst exhibited higher selectivity to longer chain hydrocarbons, a phenomenon which was also observed in experiments involving algal lipids as the feed. Characterization of fresh and spent catalysts indicates that Cu enhances the reducibility of Ni and suppresses both cracking reactions and coke-induced deactivation

Nanoparticules de nickel supportées sur silice préparées en milieu aqueux (Mécanismes de formation. Caractérisation. Propriétés de surface)

Le travail de A. Boudjahem porte sur des catalyseurs au nickel supportés sur silice, préparés par réduction d'acétate de nickel par l'hydrazine aqueuse. La cinétique et les mécanismes de formation des nanoparticules formées ont été étudiées. Les particules métalliques préparées ont été caractérisées par DRX, MET, XPS, BAM, BET, Chimisorption et TPD d'hydrogène. Leurs performances catalytiques ont été testées dans les réactions d'hydrogénation du benzène et de l'acétylène. Effet spillover de H2, cinétique et mécanismes en hydrogénation du benzène ont été examinés. Les résultats obtenus montrent que les propriétés de surface des nanoparticules supportées sont fortement déterminées par leur taille et morphologie, lesquelles dépendent à leur tour des pré- traitements thermiques, de la nature et de la texture du support, du mode de réduction du précurseur.The work of A. Boudjahem deals with nickel catalysts supported on silica prepared by nickel acetate reduction by aqueous hydrazine. The kinetics and mechanisms of the metal particles formed have been studied. The obtained particles have been characterized by XRD, TEM, XPS, BAM, BET, H2 Chemisorption and TPD techniques. Their catalytic performances have been tested in benzene and acetylene hydrogenation reactions. H2 spillover, kinetics and mechanisms in benzene hydrogenation have been studied. The obtained results showed that the supported nanoparticle surface properties strongly depended on their size and shape, which, in turn, depended on thermal pretreatments, nature and texture of the support, the mode of the precursor reduction.NANCY1-SCD Sciences & Techniques (545782101) / SudocSudocFranceF

Quantification of the pine processionary caterpillar Thaumetopoea pityocampa (Notodontidae) haemocytes

Thaumetopoea pityocampa is an important pine pest in the Mediterranean basin and central Europe and larvae are called pine processionary caterpillars. To understand the resistance mehcanism for management, a study on the immune system and reactions of the larva in different stage was conduced. The aim of our work is to identify the hemocytes of the caterpillar during the larval stages L 2 , L 3 and L 4 , as well as the quantification of the different cells during each stage. After extraction of the hemolymph by centrifugation, the cells were placed in culture medium and then incubated. Microscopic observation has shown that prohemocytes population appear early in hemolymph, they differentiate into plasmatocytes and granulocytes during the advanced stages. The quantification process has shown that granulocytes are the most abundant cell population in the hemolymph of the insect larvae. To investigate the role of hemocytes in immune responses, cells of T. pityocampa were co-incubated with bacteria, entomopathogenic nematodes and synthetic beads. Both humoral and cellular encapsulation processes was observed early in larval stages, all hemocytes seem to be involved in the formation of nodules and capsules against bacteria and microbeads. The entomopathogenic nematodes(Steinemema feltiae) were not recognized and encapsulated, but their presence can strongly damages host hemocytes