Epidemiological models and Lyapunov functions

International audienceWe give a survey of results on global stability for deterministic compartmental epidemiological models. Using Lyapunov techniques we revisit a classical result, and give a simple proof. By the same methods we also give a new result on differential susceptibility and infectivity models with mass action and an arbitrary number of compartments. These models encompass the so-called differential infectivity and staged progression models. In the two cases we prove that if the basic reproduction ratio R0 \leq 1, then the disease free equilibrium is globally asymptotically stable. If R0 > 1, there exists an unique endemic equilibrium which is asymptotically stable on the positive orthant

Intelligent Detection of MAC Spoofing Attack in 802.11 Network

In 802.11, all devices are uniquely identified by a Media Access Control (MAC) address. However, legitimate MAC addresses can be easily spoofed to launch various forms of attacks, such as Denial of Service attacks. Impersonating the MAC address of a legitimate user poses a big challenge for cyber crime investigators. Indeed, MAC spoofing makes the task of identifying the source of the attack very diffi- cult. Sequence number analysis is a common technique used to detect MAC spoofing attack. Existing solutions relying on sequence number analysis, adopt a threshold-based approach where the gap between consecutive sequence numbers is compared to a threshold to decide the presence of a MAC spoofing attack. Nevertheless, threshold-based approach may lead to a high rate of false alerts due to lost or duplicated frames. To overcome the limitations of threshold-based approach, this paper proposes a detection method that relies on a machine learning approach, namely Artificial Neural Network (ANN). ANNs provide the potential to identify and classify network behavior from limited, noisy, incomplete and nonlinear data sources. The experimentation results showed the effectiveness of the proposed detection technique. Moreover, we proposed a user-friendly graphical representation of information to support the interpretation of quantitative results

Préparation du fromage frais à partir du lait recombiné

Le but de cette étude a été d'évaluer les possibilités de préparation du fromage frais à partir du lait recombiné qui a été pasteurisé puis conservé pendant une nuit à 6°C pour faciliter la réhydratation. Le lait a été ensuite inoculé avec le levain constitué à parts égales de L. lactis subsp. lactis, L. lactis subsp. lactis var. diacetylactis et L. casei subsp casei à raison de 3% puis maintenu entre 30 et 37°C pour activer la fermentation. À pH 5,0 à 5,5, la présure a été ajoutée puis le moulage a été réalisé à température ambiante lorsque le pH a atteint une valeur comprise entre 4,3 .. 5,0. L'adoption de cette procédure normalisée de préparation du fromage frais a donné lieu à des produits de composition physico-chimique régulière et de qualité microbiologique satisfaisante. L'analyse sensorielle du fromage frais a montré que les produits élaborés à partir du lait recombiné uniquement (100%), ont été moins appréciés que ceux préparés à partir du lait recombiné additionné de 25 ou 50% de lait frais.Manufacture of fresh cheese from recombined milkThis study was carried out to evaluate the possibility of making fresh cheese from recombined milk. For this preparation, recombined milk was pasteurized and cooled overnight at 6°C to improve the powder rehydration. Then, milk was inoculated with 3% of a lactic starter composed of L.lactis subsp. lactis, L. lactis subsp.lactis var. diacetylactis and L. ca sei subsp. casei, and kept at 30 - 3TC to activate fermentation. At pH 5,0 - 5,5, the rennet was added and moulding was realized at ambient temperature when the pH reached a value of 4,3 to 5,0. Standardization of the processing gave fresh cheese with a regular chemical composition and a satisfactory microbiological quality. The sensory evaluation of fresh cheese showed that the products made with 100% recombined milk were less appreciated than those prepared from recombined milk added up with 20 to 25% fresh milk

Préparation du fromage frais à partir du lait recombiné

Le but de cette étude a été d'évaluer les possibilités de préparation du fromage frais à partir du lait recombiné qui a été pasteurisé puis conservé pendant une nuit à 6°C pour faciliter la réhydratation. Le lait a été ensuite inoculé avec le levain constitué à parts égales de L. lactis subsp. lactis, L. lactis subsp. lactis var. diacetylactis et L. casei subsp casei à raison de 3% puis maintenu entre 30 et 37°C pour activer la fermentation. À pH 5,0 à 5,5, la présure a été ajoutée puis le moulage a été réalisé à température ambiante lorsque le pH a atteint une valeur comprise entre 4,3 .. 5,0. L'adoption de cette procédure normalisée de préparation du fromage frais a donné lieu à des produits de composition physico-chimique régulière et de qualité microbiologique satisfaisante. L'analyse sensorielle du fromage frais a montré que les produits élaborés à partir du lait recombiné uniquement (100%), ont été moins appréciés que ceux préparés à partir du lait recombiné additionné de 25 ou 50% de lait frais.Manufacture of fresh cheese from recombined milkThis study was carried out to evaluate the possibility of making fresh cheese from recombined milk. For this preparation, recombined milk was pasteurized and cooled overnight at 6°C to improve the powder rehydration. Then, milk was inoculated with 3% of a lactic starter composed of L.lactis subsp. lactis, L. lactis subsp.lactis var. diacetylactis and L. ca sei subsp. casei, and kept at 30 - 3TC to activate fermentation. At pH 5,0 - 5,5, the rennet was added and moulding was realized at ambient temperature when the pH reached a value of 4,3 to 5,0. Standardization of the processing gave fresh cheese with a regular chemical composition and a satisfactory microbiological quality. The sensory evaluation of fresh cheese showed that the products made with 100% recombined milk were less appreciated than those prepared from recombined milk added up with 20 to 25% fresh milk

Richesse et diversité floristique de la suberaie de la Mamora (Maroc).

RÉSUMÉ. Richesse et diversité floristique de la suberaie de la Mamora (Maroc). L’étude vise la quantification de la richesse et de la diversité floristique de l’écosystème à chêne - liège de la forêt de la Mamora sur la base de transects et relevés floristiques répartis selon un échantillonnage stratifié et systématique dans différentes formations végétales préalablement distinguées. Les résultats montrent que l’écosystème renferme 62 familles, 261 genres, 408 espèces, sous-espèces et variétés. 35 taxons sont très rares et 29 rares. 18 taxons sont endémiques, 1 très rare et endémique et 4 rares et endémiques. L’étude a, par ailleurs, permis de révéler la disparition totale de Erica arborea et E. scoparia de cet écosystème et de définir le spectre biologique de la région d’étude qui se caractérise par une nette dominance des thérophytes (50.5%).Mots clés. Quercus suber, richesse, diversité, Mamora, Maroc.ABSTRACT. Floristic richeness and diversity of the Mamora’s Cork Oak forest (Morocco.) The survey aims to quantify the floristic richeness and diversity of the Mamora’s forest oak-cork ecosystem on the basis of transects and floristic samples distributed according to a stratified and systematic sampling in the different plant formations previously distinguished. The results show that the ecosystem contains 62 families, 261 genders, 408 species, subspecies and varieties : 35 very rare taxa , 29 rare taxa ; 18 endemic taxa, 1 very rare and endemic taxa and 4 rare and endemic taxa. The survey has, otherwise, permitted to reveal the total disappearance of Erica arborea and E. scoparia from this ecosystem and to define the biological spectrum of the studied region, wich is characterized with a clear dominance of therophytes (50.5%).Keys words. Quercus suber, richeness, diversity, Mamora, Morocco

Effects of Exercise Training on Bone Health Parameters in Individuals With Obesity:A Systematic Review and Meta-Analysis

International audienceBackground: Osteoporosis causes bone fragility, increasing the risk of fractures. Evidence suggests a strong correlation between obesity and fracture risk. Physical training is known to enhance bone resistance and protect from fracture; however, its osteogenic effect in the presence of obesity remains unknown.and nbsp;Objective: We sought to evaluate the influence of exercise training on bone health indices in individuals with obesity.and nbsp;Methods: This systematic literature search was conducted using common electronic databases from inception - December 2019. The following key terms (and synonyms searched for by the MeSH database) were included and combined using the operators "AND, " "OR, " "NOT ": [( "body mass index " OR obesity OR obese OR overweight OR fat mass) AND ( "bone mineral density " OR "bone mineral content " OR "peak bone mass " OR "mechanical loading " OR "Osteoporosis " OR "bone geometry " OR "bone resistance ") AND ( "exercise training " OR "physical training " OR "strength training, " OR "resistance training " OR "aerobic training " OR "combined training ")].and nbsp;Results: After screening, 10 studies (889 initial records) were included in the final analysis (8 different countries, 263 participants). Two studies investigated males, six females, and two, both sexes. The training duration was at least eight weeks with 2-3 sessions/week. Physical training displayed a significant trivial impact on the whole body (WB) BMD (0.13 SMD; 95% CI [0.00, 0.26], p = 0.046). Subgroup analyses indicated a significant small increase in the WB BMD (0.27 SMD; 95% CI [0.00, 0.53], p = 0.048) in the endurance training group, a non-significant trivial increase in the WB BMD (0.11 SMD; 95% CI [-0.06, 0.29], p = 0.203) in the resistance group, and a non-significant trivial increase in the WB BMD (0.03 SMD; 95% CI [-0.26, 0.32], p = 0.86) in the combined training group. In addition, a significant small decrease was found in the weight of trained subjects (-0.24 SMD; 95% CI [-0.42, -0.05], p = 0.011).and nbsp;Conclusion: Physical training has little to no effect on the WB BMD in subjects with overweight/obesity. Currently, insufficient evidence to advocate for any specific type of exercise for enhancing bone health exists for overweight/obese individuals. Investigations examining the impact of varying types of physical exercise on WB BMD of obese individuals are needed

The Pseudomonas aeruginosa T6SS Delivers a Periplasmic Toxin that Disrupts Bacterial Cell Morphology.

The type VI secretion system (T6SS) is crucial in interbacterial competition and is a virulence determinant of many Gram-negative bacteria. Several T6SS effectors are covalently fused to secreted T6SS structural components such as the VgrG spike for delivery into target cells. In Pseudomonas aeruginosa, the VgrG2b effector was previously proposed to mediate bacterial internalization into eukaryotic cells. In this work, we find that the VgrG2b C-terminal domain (VgrG2bC-ter) elicits toxicity in the bacterial periplasm, counteracted by a cognate immunity protein. We resolve the structure of VgrG2bC-ter and confirm it is a member of the zinc-metallopeptidase family of enzymes. We show that this effector causes membrane blebbing at midcell, which suggests a distinct type of T6SS-mediated growth inhibition through interference with cell division, mimicking the impact of β-lactam antibiotics. Our study introduces a further effector family to the T6SS arsenal and demonstrates that VgrG2b can target both prokaryotic and eukaryotic cells

Enhancing the control of doubly fed induction generators using artificial neural networks in the presence of real wind profiles

This study tackles the complex task of integrating wind energy systems into the electric grid, facing challenges such as power oscillations and unreliable energy generation due to fluctuating wind speeds. Focused on wind energy conversion systems, particularly those utilizing double-fed induction generators (DFIGs), the research introduces a novel approach to enhance Direct Power Control (DPC) effectiveness. Traditional DPC, while simple, encounters issues like torque ripples and reduced power quality due to a hysteresis controller. In response, the study proposes an innovative DPC method for DFIGs using artificial neural networks (ANNs). Experimental verification shows ANNs effectively addressing issues with the hysteresis controller and switching table. Additionally, the study addresses wind speed variability by employing an artificial neural network to directly control reactive and active power of DFIG, aiming to minimize challenges with varying wind speeds. Results highlight the effectiveness and reliability of the developed intelligent strategy, outperforming traditional methods by reducing current harmonics and improving dynamic response. This research contributes valuable insights into enhancing the performance and reliability of renewable energy systems, advancing solutions for wind energy integration complexities

The application of artificial intelligence in diabetic retinopathy screening: a Saudi Arabian perspective

IntroductionDiabetic retinopathy (DR) is the leading cause of preventable blindness in Saudi Arabia. With a prevalence of up to 40% of patients with diabetes, DR constitutes a significant public health burden on the country. Saudi Arabia has not yet established a national screening program for DR. Mounting evidence shows that Artificial intelligence (AI)-based DR screening programs are slowly becoming superior to traditional screening, with the COVID-19 pandemic accelerating research into this topic as well as changing the outlook of the public toward it. The main objective of this study is to evaluate the perception and acceptance of AI in DR screening among eye care professionals in Saudi Arabia.MethodsA cross-sectional study using a self-administered online-based questionnaire was distributed by email through the registry of the Saudi Commission For Health Specialties (SCFHS). 309 ophthalmologists and physicians involved in diabetic eye care in Saudi Arabia participated in the study. Data analysis was done by SPSS, and a value of p < 0.05 was considered significant for statistical purposes.Results54% of participants rated their level of AI knowledge as above average and 63% believed that AI and telemedicine are interchangeable. 66% believed that AI would decrease the workforce of physicians. 79% expected clinical efficiency to increase with AI. Around 50% of participants expected AI to be implemented in the next 5 years.DiscussionMost participants reported good knowledge about AI. Physicians with more clinical experience and those who used e-health apps in clinical practice regarded their AI knowledge as higher than their peers. Perceived knowledge was strongly related to acceptance of the benefits of AI-based DR screening. In general, there was a positive attitude toward AI-based DR screening. However, concerns related to the labor market and data confidentiality were evident. There should be further education and awareness about the topic

Gene content evolution in the arthropods

Arthropods comprise the largest and most diverse phylum on Earth and play vital roles in nearly every ecosystem. Their diversity stems in part from variations on a conserved body plan, resulting from and recorded in adaptive changes in the genome. Dissection of the genomic record of sequence change enables broad questions regarding genome evolution to be addressed, even across hyper-diverse taxa within arthropods. Using 76 whole genome sequences representing 21 orders spanning more than 500 million years of arthropod evolution, we document changes in gene and protein domain content and provide temporal and phylogenetic context for interpreting these innovations. We identify many novel gene families that arose early in the evolution of arthropods and during the diversification of insects into modern orders. We reveal unexpected variation in patterns of DNA methylation across arthropods and examples of gene family and protein domain evolution coincident with the appearance of notable phenotypic and physiological adaptations such as flight, metamorphosis, sociality, and chemoperception. These analyses demonstrate how large-scale comparative genomics can provide broad new insights into the genotype to phenotype map and generate testable hypotheses about the evolution of animal diversity