Cyclopharma (France)

Abstract This paper analyzes the performance of the Fractal Decomposition Algorithm (FDA) metaheuristic applied to low-dimensional continuous optimization problems. This algorithm was originally developed specifically to deal efficiently with high-dimensional continuous optimization problems by building a fractal-based search tree with a branching factor linearly proportional to the number of dimensions. Here, we aim to answer the question of whether FDA could be equally effective for low-dimensional problems. For this purpose, we evaluate the performance of FDA on the Black Box Optimization Benchmark (BBOB) for dimensions 2, 3, 5, 10, 20, and 40. The experimental results show that overall the FDA in its current form does not perform well enough. Among different function groups, FDA shows its best performance on Misc. moderate and Weak structure functions.KeywordsContinuous optimizationMetaheuristicsFractal decompositionBlack Box Optimization Benchmark

The Enterobacter cloacae complex (ECC) is a group of diverse environmental and clinically relevant bacterial species associated with a variety of infections in humans. ECC have emerged as one of the leading causes of nosocomial infections worldwide. The purpose of this paper is to evaluate the activity of NOSO-502 and colistin (CST) against a panel of ECC clinical isolates, including different Hoffmann's clusters strains, and to investigate the associated resistance mechanisms. NOSO-502 is the first preclinical candidate of a novel antibiotic class, the odilorhabdins (ODLs). MIC50 and MIC90 of NOSO-502 against ECC are 1 μg/mL and 2 μg/mL, respectively, with a MIC range from 0.5 μg/mL to 32 μg/mL. Only strains belonging to clusters XI and XII showed decreased susceptibility to both NOSO-502 and CST while isolates from clusters I, II, IV, and IX were only resistant to CST. To understand this phenomenon, E. cloacae ATCC 13047 from cluster XI was chosen for further study. Results revealed that the two-component system ECL_01761-ECL_01762 (ortholog of CrrAB from Klebsiella pneumoniae) induces NOSO-502 hetero-resistance by expression regulation of the ECL_01758 efflux pump component (ortholog of KexD from K. pneumoniae) which could compete with AcrB to work with the multidrug efflux pump proteins AcrA and TolC. In E. cloacae ATCC 13047, CST-hetero-resistance is conferred via modification of the lipid A by addition of 4-amino-4-deoxy-l-arabinose controlled by PhoPQ. We identified that the response regulator ECL_01761 is also involved in this resistance pathway by regulating the expression of the ECL_01760 membrane transporter.

Abstract Developing activities or tasks in the oil industry, demands great knowledge and experience for their execution. However, contracting local non-specialized workforce has become a challenge in terms of risk prevention and control for those who are exposed and do not have experience and knowledge in workover and well service operations (WO/WS operations). Accidents have caused injuries, property damages and operative incidents. WO/WS operations accident rate represents 39% of the field's total, i.e., there is greater risk exposure thus activities are more critical. A worker, who has been properly trained, is aware of the risks and knows what must be done in such regard. Research has shown that training is one of the most important factors in successful safety programs. The above confirms the relevance and importance of such training practices, which emphasize on the initial instruction and follow-up of workplace safety procedures. The analysis in this paper is based on the need to have competent workers able to perform their activities, for which they must have specific knowledge, behaviors and skills related to their assignments. Achieving the above requires a systematic training, considered under a planned set-up process so that they can do their job in a safe manner, as well as the transfer of techniques that not only develop awareness, information and knowledge, but also how-to related skills through a "commitment that implies getting one's hands dirty, learning by doing and a guided practice". The decision to look for alternatives aiming at strengthening knowledge and work best practices was made jointly with WO/WS contractor companies, betting on the optimization of the operations in terms of safety that would subsequently reduce the accident rate. The skill strengthening strategy was first implemented in the last month of 2017 and was exclusively directed for key personnel of WO/WS operations. This paper intends to analyze risk reduction in a population exposed to work accidents in the WO/WS operations for the following positions: supervisor, rig operator, derrick man and roughneck, for the period between 2014 and 2019, showing a considerable drop in occupational accident rate for the last year.

Adsorption characteristics of 2,4-dichlorophenoxyacetic acid (2,4-D) (herbicide) and flumequine (bactericide) on synthetic goethite are presented here. The nature of interactions between adsorbate and adsorbent has been investigated by solution depletion, electrophoretic mobility, and infrared spectroscopic methods. The adsorption has been found to be due to the interactions between the surface charge of goethite and the ionized acids as pH plays an important role. In the case of flumequine, which adsorbs more strongly than 2,4-D, the possibility of adsorption of neutral molecules also exists. While the results of all the methods complement each other in the case of flumequine, there seems to be some discrepancy in the case of 2,4-D. Solution depletion results indicate weak interactions whereas infrared and electrophoretic mobility measurements show the possibility of specific interactions for 2,4-D. The results are discussed to arrive at a possible mechanism of adsorption.

Alors que Le Parisien perd de l’argent depuis vingt-cinq ans et que L’équipe décline doucement, la patronne du groupe Amaury demande à un industriel de s’attaquer à l’ordre établi et à la culture traditionnelle afin de désormais faire vivre son entreprise dans le nouvel écosystème digital. Six ans plus tard, les titres du Groupe ont renoué avec les bénéfices et les journalistes se sont ouverts à la maîtrise des outils numériques ainsi qu’à de nouveaux modes d’expression.

Cell surface-exposed and secreted proteins are attractive targets for vaccination against pathogenic gram-positive bacteria. To obtain sufficient amounts of such antigens, efficient protein production platforms are needed. In this study, a pipeline for the production and purification of surface-exposed and secreted antigens of the gram-positive bacterial pathogen Staphylococcus aureus is presented. Cytoplasmic or extracellular production of S. aureus antigens was achieved using the Lactococcus lactis strain PA1001, which lacks the major extracellular protease HtrA and the autolysin AcmA to minimize proteolysis and cell lysis, respectively. For most tested S. aureus antigens, secretory production directed by the signal peptide of the major secreted protein Usp45 of L. lactis resulted in higher yields than intracellular production without a signal peptide. Additionally, secretory production of His-tagged antigens allowed their facile one-step purification from the growth medium by metal affinity chromatography. For three of the purified antigens, biological activity was confirmed through enzyme activity assays. We, furthermore, show that the present pipeline can be used to produce staphylococcal antigens with an N-terminal AVI-tag for site-specific labeling with biotin or a C-terminal cell wall-binding domain for cell surface display. We conclude that our L. lactis-based pipeline allows the efficient production of S. aureus antigens and their subsequent purification in one step.