University of Bejaia

Sex allocation theory predicts that parasitoid wasps adjust offspring sex ratio in response to local mate competition (LMC), host quality, and intraspecific competition, with higher female density expected to produce less female-biased broods. Anisopteromalus calandrae is a solitary idiobiont ectoparasitoid of stored-product beetles and a promising agent for augmentative biological control, but how closely its sex allocation follows theory under rearing and release conditions is unclear. We examined how exploitative and interference competition influence parasitism and progeny sex ratio using laboratory and mesocosm assays with Callosobruchus maculatus as host. First, females were offered unparasitized vs. previously parasitized hosts to test whether superparasitism shifts allocation; sex ratios remained strongly female-biased regardless of host status or egg age, suggesting little effect of exploitative competition. Second, we varied foundress number while keeping the host-to-female ratio constant. Parasitism and per-female progeny changed only weakly with density, and sex ratios followed LMC expectations at low - intermediate densities (1-8 females) but became even more female-biased at high densities (25-50), deviating from Hamilton's model. In mesocosms mimicking storage, A. calandrae suppressed C. maculatus by >97% at all densities, while sex ratios stayed stable and female-biased. Parasitoid-induced mortality was high and did not vary with density, indicating limited interference costs at this scale. Overall, A. calandrae exhibited strongly female-biased sex allocation with very little density-dependent plasticity. This result supports its applied potential while emphasizing divergence from classical.

Bone tissue engineering (BTE) aims to address the complex challenge of regenerating critical-size bone defects, where conventional healing is insufficient. This work compares the morphological characteristics of FHA-based scaffolds fabricated via three different methods: solvent casting with particle leaching, freeze-drying, and 3D printing. Each technique demonstrated unique advantages: solvent casting with salt leaching produced interconnected microporous scaffolds (0.5-2 mu m), suitable for cell migration and nutrient diffusion, but with limited control over global geometry. Freeze-drying generated slightly larger pores (2-4 mu m) through ice crystal sublimation, offering improved porosity and surface area while preserving the material's composition. In contrast, 3D printing enabled precise architectural control, yielding scaffolds with dual-scale porosity-micropores (similar to 35 mu m) and macropores (similar to 2000 mu m)-that enhance cell infiltration, vascularization, and osteointegration. The experimental results confirmed initial hypotheses regarding each fabrication method's influence on scaffold morphology. While traditional methods like salt leaching and freeze-drying effectively generate functional porosity, 3D printing stands out for its reproducibility, design versatility, and potential for drug incorporation and controlled release. Therefore, 3D printing was selected as the most suitable platform for the continuation of this study, particularly for advanced applications in tissue engineering and bone regeneration.

Introduction Inflammatory bowel disease (IBD) is a chronic intestinal disorder that affects many individuals worldwide. Moringa oleifera is a valued plant offering significant therapeutic and nutritional benefits. It has emerged as a promising source of bioactive compounds. Among its phytochemicals, alkaloids are known for their notable antioxidant and anti-inflammatory activities. This study aims to investigate the potential antioxidant and anti-inflammatory effects of a total alkaloid extract from Moringa oleifera leaves (AMO) in a DNBS-induced colitis model in BALB/c mice.Methods Three doses of total alkaloid extract from Moringa oleifera (AMO) (25, 50, and 100 mg/kg) were administered orally after the induction of colitis via rectal administration of DNBS. The inflammation was recorded daily using the disease activity index (DAI), biochemical analysis, and histological assessment. In this context, colon tissue samples were used to assess microscopic scores and to determine the dosage of biochemical markers, including myeloperoxidase (MPO) and catalase (CAT) activities, and reduced glutathione (GSH), malondialdehyde (MDA), and nitric oxide (NO) levels.Results It was determined that AMO treatment significantly reduced the severity of colitis, evidenced by reduced DAI and lower histological damage scores. Antioxidant markers were elevated in the treated groups, whereas NO, MDA, and MPO levels were elevated in untreated colitic mice.Discussion The results highlight the therapeutic potential of Moringa oleifera alkaloid extract; the anti-inflammatory effect may be mediated by reductions in MDA, MPO, and NO levels and by increases in CAT and GSH levels.Conclusion These findings suggest that Moringa oleifera alkaloid extract may offer a promising natural adjunct for IBD management through modulation of oxidative and inflammatory pathways.

Proteomics has become an important tool in domestic animal science over the last decade, with applications ranging from meat to dairy production. Research in livestock proteomics has primarily focused on conventional species such as cattle, pigs, and poultry, while less attention has been given to non-conventional species like the dromedary (Camelus dromedarius). This study evaluated the effect of two production systems (extensive vs. intensive) on the longissimus lumborum muscle proteome of male Sahraoui dromedary camels using a label-free proteomics approach. A total of 1405 proteins were identified, of which 40 were differentially abundant between production systems. The camel muscle proteome showed similarities with that of domestic ruminants. Differentially accumulated proteins were mainly associated with catalytic activity (40%) and binding functions (36%). Animals raised in extensive systems exhibited higher abundance of proteins related to energy metabolism and contractile apparatus, likely reflecting the increased locomotion required for grazing across large rangelands. In contrast, the intensive group showed higher levels of proteins involved in amino acid and lipid metabolism, consistent with the higher protein supply from concentrate feed and the greater growth rates observed in this system. These findings contribute to understanding camel muscle metabolism and provide insights relevant for distinguishing production systems, with potential applications in traceability.

Research in electric discharge and industrial applications led to the requirement of advanced engineering materials that can withstand various temperatures without significantly affecting their properties. This paper aims to analyse the behaviour of electric discharge in wire-to-plane electrostatic precipitators as a function of temperature. In wire-to-plane electrostatic precipitators at varying temperatures, the physical parameters, including the current-voltage characteristic, onset voltage, corona conductance, electric field, and current density distributions of the discharge DC corona, were experimentally examined, with the corona discharge serving as the ionization source. This project involved the design and construction of an experimental cell to regulate its internal temperature. The current density and electric field were ascertained using the Tassicker model and a statistical analysis with the regression model validated the current-voltage characteristics. The increase in temperature correlated with a rise in the corona current at the collector plate, while the onset voltage diminished. The applied voltage and temperature significantly influenced the properties of corona current density and the electric field. The temperature for a given atmospheric condition strongly affected the discharge current, according to the experimental results. Changing the values of temperature not only changed the property of the gas but also affected the corona onset conditions and ion mobility.