The antimicrobial effect of hydrastis canadensis mother tincture and herbal extract on staphylococcus aureus and escherichia coli in-vitro

Abstract: Antibiotic resistance has become one of the largest threats to the health of human beings worldwide. The combination of large amounts of antibiotics prescribed over many decades has resulted in the rapid development of bacterial resistance. The spread of multiple antibiotic resistant organisms are becoming more prevalent, traditional antibiotics are no longer effective and the rate at which new antibiotics are developed has significantly dropped in the last decades. There is an urgent need for new therapeutic approaches for the treatment of illnesses caused by bacteria. The aim of this study was to determine the antimicrobial effect of Hydrastis canadensis herbal extract and Hydrastis canadensis mother tincture on Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) reference strains. These organisms where chosen since infections caused by them are commonly treated with a wide variety of antibiotics that produces undesirable side effects. S. aureus and E. coli have developed resistance to many classes of antibiotics which makes formerly treatable conditions increasingly difficult to treat. This study was done by means of the Kirby-Bauer Disk Diffusion Method and Microdilution method to determine the Minimum Inhibitory Concentration (MIC) of the Hydrastis canadensis herbal extract and Hydrastis canadensis mother tincture. Cultures on agar plates (for use with the Kirby-Bauer Disk Diffusion test) or in liquid cultures (for use with broth dilution cultures) were grown overnight at 35°C for 16-18 hours. Sterile disks were impregnated with the Hydrastis canadensis herbal extract and Hydrastis canadensis mother tincture. Following incubation the plates were examined for a zone of inhibition of bacterial growth and the zone measured in millimetres. To determine the Minimum Inhibitory Concentration (MIC) of the compounds, the serial dilution method in 96 well plates were tested, labeled and into each well 100 µl Mueller-Hinton broth was added. The compound to be tested (50 µl) was added to the first V well, mixed and 50 µl removed, added to the next well and repeated for the next four wells. The 50 µl removed from the sixth well and discarded. After the incubation period 50 µl Iodonitrotetrazolium chloride (INT) dye was added to the wells, incubated at 35°C for up to 30 min, to produce a pink to dark purple color. The results demonstrated that Hydrastis canadensis herbal extract and Hydrastis canadensis mother tincture inhibited the growth of S. aureus which was confirmed by the Kirby-Bauer Disk Diffusion and Microdilution methods. The Hydrastis canadensis herbal extract and Hydrastis canadensis mother tincture inhibited the growth of E. coli but was only confirmed by the adaptation of the 96 well microdilution methods by increasing the concentration of the Hydrastis canadensis herbal extract and Hydrastis canadensis mother tincture as well as forcing the E. coli into contact with the substances. The Hydrastis canadensis herbal extract and Hydrastis canadensis mother tincture showed no antimicrobial effects when tested with the Kirby-Bauer Disk Diffusion method as bacterial swarming, minimum dosing or decreased concentration of the active compounds could have been a factor. Further investigation into why the Microdilution method yielded positive results rather than the Kirby-Bauer Disk Diffusion method for E. coli found that E. coli’s flagella driven motility allowed the bacteria to swim away and protect itself from the compound resulting in a false negative. When E. coli was forced into contact with the compound, inhibition of growth was observed. Overall it was found that the herbal extract had a greater antimicrobial effect than the mother tincture. In conclusion, Hydrastis canadensis did work against S. aureus and to an extent against E. coli when forced into contact with the Hydrastis canadensis but we need a better understanding of whether it is bactericidal or bacteriostatic. It needs to be ensured that when using this, it is the correct method and that we test and expand the number of strains to determine if there is no interchange and how it relates to antibiotic resistance.M.Tech. (Homoeopathy

An original differentiation tool for identification on continuous structures

International audienceThe present contribution is dedicated to the identification of mechanical parameters, especially distributed parameters for continuous structures. In the following, the continuous time identification method is adapted and improved. Firstly an original expansion method using Gauss-points is presented. A novel differentiation method is then developed and compared to a classical one. These improvements are tested numerically and experimentally. This general method can be applied to system identification, structure identification, damage detection, etc. The main advantage of it is its high order differentiation capability. Therefore, this method is applied to structure monitoring on a cantilever beam in flexural motion (which involves a fourth derivative). In the treated example, the parameter ρS/EI and the fourth derivative ∂4v/∂x4 are computed. The parameter ρS/EI is accurately reconstructed for the whole beam, using different sensor patch lengths and the identification method is shown to be a precise tool for damage location. The computed fourth derivative emphasizes the discontinuity due to the crack. Using only the discontinuity property of a crack, no assumption is needed about crack behaviour. This novel differentiation technique makes it possible to compute changes and is of great interest for damage location

Food allergy enhances allergic asthma in mice

BackgroundAtopic march refers to the typical transition from a food allergy in early childhood to allergic asthma in older children and adults. However the precise interplay of events involving gut, skin and pulmonary inflammation in this process is not completely understood.ObjectivesTo develop a mouse model of mixed food and respiratory allergy mimicking the atopic march and better understand the impact of food allergies on asthma.MethodsFood allergy to ovalbumin (OVA) was induced through intra-peritoneal sensitization and intra-gastric challenge, and/or a respiratory allergy to house dust mite (HDM) was obtained through percutaneous sensitization and intra-nasal challenges with dermatophagoides farinae (Der f) extract. Digestive, respiratory and systemic parameters were analyzed.ResultsOVA-mediated gut allergy was associated with an increase in jejunum permeability, and a worsening of Der f-induced asthma with stronger airway hyperresponsiveness and pulmonary cell infiltration, notably eosinophils. There was overproduction of the pro-eosinophil chemokine RANTES in broncho-alveolar lavages associated with an enhanced Th2 cytokine secretion and increased total and Der f-specific IgE when the two allergies were present. Both AHR and lung inflammation increased after a second pulmonary challenge.ConclusionGut sensitization to OVA amplifies Der f-induced asthma in mice

The goliath project: Towards an internationally harmonised approach for testing metabolism disrupting compounds

Copyright © 2020 by the authors. The purpose of this project report is to introduce the European “GOLIATH” project, a new research project which addresses one of the most urgent regulatory needs in the testing of endocrine-disrupting chemicals (EDCs), namely the lack of methods for testing EDCs that disrupt metabolism and metabolic functions. These chemicals collectively referred to as “metabolism disrupting compounds” (MDCs) are natural and anthropogenic chemicals that can promote metabolic changes that can ultimately result in obesity, diabetes, and/or fatty liver in humans. This project report introduces the main approaches of the project and provides a focused review of the evidence of metabolic disruption for selected EDCs. GOLIATH will generate the world’s first integrated approach to testing and assessment (IATA) specifically tailored to MDCs. GOLIATH will focus on the main cellular targets of metabolic disruption—hepatocytes, pancreatic endocrine cells, myocytes and adipocytes—and using an adverse outcome pathway (AOP) framework will provide key information on MDC-related mode of action by incorporating multi-omic analyses and translating results from in silico, in vitro, and in vivo models and assays to adverse metabolic health outcomes in humans at real-life exposures. Given the importance of international acceptance of the developed test methods for regulatory use, GOLIATH will link with ongoing initiatives of the Organisation for Economic Development (OECD) for test method (pre-)validation, IATA, and AOP development

Vers une nouvelle méthodologie de conception des bâtiments, basée sur leurs performances bioclimatiques

With the current issues concerning the potential savings in the building sector, reducing building energy consumption is a key point. Up to now, efforts have been focused on insulation to separate the inner ambiance from the fluctuation of the outside air temperature. However, insulating a building from its environment deprives it from the renewable free energy sources which exchange with the envelope, either they are heating or cooling sources. Using the building envelope to exploit these resources is the very principle of the bioclimatic architecture. But bioclimatic systems have never been evaluated regarding the amount of available energy they could use, partly because the energy exchanges between the resources and the building have never been really qualified regarding to the building needs, neither quantified in terms of available energy capacity to meet these needs. The aim of this thesis is thus to propose a method to assess both: - the capacity of the environmental resources to cover the building needs, - the ability of the building to exploit the available energy resources. The method is mainly based on energy simulation and the basic data is a comparison of the behaviour of a building with and without a given environmental resource. The building energy needs without the resource can be compared to the resource potential and this comparison give the useful potential of the resource. Moreover, by comparing the building energy needs in the simulation with and without resource, we can get the amount of energy actually used by the building. From these two quantities, the useful and the exploited potential, a set of indicators can be defined and adapted to thermal comfort (heating and cooling needs) and three resources (sun, sky and air). The indicators are then applied to a study case and the results are analysed not only at the scale of the building, but also at the scale of each part of the envelope. A first analysis of the global results over the year is performed to get a first understanding of the state of the resources and the building performances. In a second step, the values are analysed at each time step, to characterize the behaviour of the building towards the environment. Finally, the indicators can be used to design buildings, in several ways. We performed a parametric analysis of the insulation level over the potential and performance indicators. Then, we used them to assess the bioclimatic performances of existing solar technologies. In a final step, the indicators have been used as criteria to optimize the building envelope parameters. Thus, the envelope parameters are optimized according to the minimization of the energy need, but also according to the maximization of the exploited potential.Les règles et usages actuels de conception des bâtiments sont essentiellement basés sur la minimisation des déperditions thermiques, ce qui se traduit par la prédominance de l’isolation thermique comme solution d’enveloppe. Or cette logique n'est pas nécessairement la plus pertinente car des ressources énergétiques existent dans l'environnement, et leur apport mériterait d'être pris en considération. Certaines technologies bioclimatiques, et surtout solaires, existent déjà mais leur utilisation n'est pas du tout généralisée à cause d'un manque de repère sur leurs performances. Pour considérer la démarche bioclimatique, il est nécessaire de pouvoir évaluer à la fois la "qualité énergétique" de l'environnement, et l'aptitude des bâtiments à exploiter cet environnement. La méthodologie présentée dans cette thèse est basée sur le calcul d'indicateurs de performance bioclimatique issus de simulations numériques de bâtiments dans diverses conditions climatiques. La simulation permet de supprimer facilement une ressource pour pouvoir obtenir les besoins d'un bâtiment non impacté par la ressource. Ces besoins peuvent alors être comparés à chaque instant au potentiel de la ressource afin de déterminer un potentiel utile, valorisable par le bâtiment. Il est également possible de comparer les besoins du bâtiment dans la simulation sans et avec la ressource et d'en déduire la quantité d'énergie provenant de la ressource réellement utilisée par le bâtiment pour couvrir ses besoins. Un jeu d'indicateurs est ainsi défini pour toutes les ressources et tous les besoins d'un bâtiment, et adapté plus particulièrement aux besoins de confort thermique (chauffage et rafraîchissement) et à trois ressources de l'environnement (le soleil, la voûte céleste et l'air extérieur). Un cas d'étude est alors choisi pour appliquer cette méthode et les résultats sont analysés à l'échelle du bâtiment tout entier ainsi qu'à l'échelle de chaque paroi. Une première analyse globale, sur toute l'année, permet de fixer des points de repères sur l'état des ressources et l'exploitation qui en est faite par les bâtiments. Dans un second temps, les résultats instantanés sont analysés de manière dynamique, et montrent que ces nouveaux indicateurs permettent de bien caractériser le comportement d'un bâtiment dans son environnement. Enfin, les indicateurs sont utilisés dans une approche de conception des bâtiments, et plusieurs pistes sont explorées. Une étude paramétrique est tout d'abord menée et permet d'observer l'influence du niveau d'isolation sur les indicateurs de potentiel et de performance. Puis ces indicateurs sont utilisés pour évaluer la performance bioclimatique de solutions d'enveloppe solaires. Dans un troisième temps, une optimisation de l'enveloppe est menée selon deux critères : un critère classique de minimisation du besoin, mais également un critère bioclimatique de maximisation de l'exploitation du potentiel solaire

Indirect boundary force measurements in beam-like structures using a derivative estimator

International audienceThis paper proposes a new method for the identification of boundary forces (shear force or bending moment) in a beam, based on displacement measurements. The problem is considered in terms of the determination of the boundary spatial derivatives of transverse displacements. By assuming the displacement fields to be approximated by Taylor expansions in a domain close to the boundaries, the spatial derivatives can be estimated using specific point-wise derivative estimators. This approach makes it possible to extract the derivatives using a weighted spatial integration of the displacement field. Following the theoretical description, numerical simulations made with exact and noisy data are used to determine the relationship between the size of the integration domain and the wavelength of the vibrations. The simulations also highlight the self-regularization of the technique. Experimental measurements demonstrate the feasibility and accuracy of the proposed method

Hybrid skyhook mass damper

The objective of this study is to increase the efficiency of an initial passive Tuned Mass Damper (TMD) by adding an active control unit. A critical issue in many engineering domains is the design of fail-safe active systems. The proposed hybrid system aims to address this issue and realizes the said objective. It emulates the behavior of a skyhook damper parallel to a passive TMD. Skyhook dampers acts like viscous dampers connected to the ground, reducing the vibration amplitudes without any overshoot. It can be difficult to design a specific control law to obtain a desired dynamical behavior. The paper presents two ways to understand and design the hyperstable control law for Hybrid Mass Damper (HMD) (also called Active TMD), using the power flow formulation or the mechanical impedance analysis. These approaches are illustrated through the synthesis of this hybrid device and the emulation of the Skyhook damper. It is shown that a well-designed control law for this kind of system may result in high damping performance, ensuring stability and a fail-safe behavior. In addition, the amplitude of the primary system’s response is reduced over the entire frequency range which is not the case for the usual active or hybrid systems. Robustness is analyzed and compared to that of the classical active mass damper, and an experimental set up validates the proposed hybrid system

Toward a new method of buidling design, based on bioclimatic performances

Les règles et usages actuels de conception des bâtiments sont essentiellement basés sur la minimisation des déperditions thermiques, ce qui se traduit par la prédominance de l’isolation thermique comme solution d’enveloppe. Or cette logique n'est pas nécessairement la plus pertinente car des ressources énergétiques existent dans l'environnement, et leur apport mériterait d'être pris en considération. Certaines technologies bioclimatiques, et surtout solaires, existent déjà mais leur utilisation n'est pas du tout généralisée à cause d'un manque de repère sur leurs performances. Pour considérer la démarche bioclimatique, il est nécessaire de pouvoir évaluer à la fois la "qualité énergétique" de l'environnement, et l'aptitude des bâtiments à exploiter cet environnement. La méthodologie présentée dans cette thèse est basée sur le calcul d'indicateurs de performance bioclimatique issus de simulations numériques de bâtiments dans diverses conditions climatiques. La simulation permet de supprimer facilement une ressource pour pouvoir obtenir les besoins d'un bâtiment non impacté par la ressource. Ces besoins peuvent alors être comparés à chaque instant au potentiel de la ressource afin de déterminer un potentiel utile, valorisable par le bâtiment. Il est également possible de comparer les besoins du bâtiment dans la simulation sans et avec la ressource et d'en déduire la quantité d'énergie provenant de la ressource réellement utilisée par le bâtiment pour couvrir ses besoins. Un jeu d'indicateurs est ainsi défini pour toutes les ressources et tous les besoins d'un bâtiment, et adapté plus particulièrement aux besoins de confort thermique (chauffage et rafraîchissement) et à trois ressources de l'environnement (le soleil, la voûte céleste et l'air extérieur). Un cas d'étude est alors choisi pour appliquer cette méthode et les résultats sont analysés à l'échelle du bâtiment tout entier ainsi qu'à l'échelle de chaque paroi. Une première analyse globale, sur toute l'année, permet de fixer des points de repères sur l'état des ressources et l'exploitation qui en est faite par les bâtiments. Dans un second temps, les résultats instantanés sont analysés de manière dynamique, et montrent que ces nouveaux indicateurs permettent de bien caractériser le comportement d'un bâtiment dans son environnement. Enfin, les indicateurs sont utilisés dans une approche de conception des bâtiments, et plusieurs pistes sont explorées. Une étude paramétrique est tout d'abord menée et permet d'observer l'influence du niveau d'isolation sur les indicateurs de potentiel et de performance. Puis ces indicateurs sont utilisés pour évaluer la performance bioclimatique de solutions d'enveloppe solaires. Dans un troisième temps, une optimisation de l'enveloppe est menée selon deux critères : un critère classique de minimisation du besoin, mais également un critère bioclimatique de maximisation de l'exploitation du potentiel solaire.With the current issues concerning the potential savings in the building sector, reducing building energy consumption is a key point. Up to now, efforts have been focused on insulation to separate the inner ambiance from the fluctuation of the outside air temperature. However, insulating a building from its environment deprives it from the renewable free energy sources which exchange with the envelope, either they are heating or cooling sources. Using the building envelope to exploit these resources is the very principle of the bioclimatic architecture. But bioclimatic systems have never been evaluated regarding the amount of available energy they could use, partly because the energy exchanges between the resources and the building have never been really qualified regarding to the building needs, neither quantified in terms of available energy capacity to meet these needs. The aim of this thesis is thus to propose a method to assess both: - the capacity of the environmental resources to cover the building needs, - the ability of the building to exploit the available energy resources. The method is mainly based on energy simulation and the basic data is a comparison of the behaviour of a building with and without a given environmental resource. The building energy needs without the resource can be compared to the resource potential and this comparison give the useful potential of the resource. Moreover, by comparing the building energy needs in the simulation with and without resource, we can get the amount of energy actually used by the building. From these two quantities, the useful and the exploited potential, a set of indicators can be defined and adapted to thermal comfort (heating and cooling needs) and three resources (sun, sky and air). The indicators are then applied to a study case and the results are analysed not only at the scale of the building, but also at the scale of each part of the envelope. A first analysis of the global results over the year is performed to get a first understanding of the state of the resources and the building performances. In a second step, the values are analysed at each time step, to characterize the behaviour of the building towards the environment. Finally, the indicators can be used to design buildings, in several ways. We performed a parametric analysis of the insulation level over the potential and performance indicators. Then, we used them to assess the bioclimatic performances of existing solar technologies. In a final step, the indicators have been used as criteria to optimize the building envelope parameters. Thus, the envelope parameters are optimized according to the minimization of the energy need, but also according to the maximization of the exploited potential

D’une évaluation à l’autre : des acquis des élèves sur les nombres en sixième à l’élaboration et à l’analyse d’une formation d’enseignants centrée sur le calcul mental.

For 25 years, national assessments show recurring findings on what students have acquired or not in mathematics at the end of French primary school. One may wonder about the contributions of these outcomes for teaching, and their potential impact on the practices of teachers in grade 6. This led us to formulate hypotheses on the origin of these findings and develop an experimental teacher training scheme called "PACEM" in which standardized assessments have dual status as information carriers as well as training tools. Then we set up a special training scheme which explicitly aims to improve the acquired skills of students whose teachers have been trained in the field of numbers and arithmetic at the outset of lower secondary school.This thesis aims to describe and analyze the whole process from the perspective of the researcher. After questioning what standardized national assessments can provide in the studied area, we use the theory of activity and didactical tools in mathematics education that we adapt (Robert & Rogalski, 2002) to make a number of assumptions about teacher training and mental calculation to develop with grade 6 students. In a third step, we explore how the experimental design was implemented in distancing ourselves from our activity as designer and trainer. Finally, through a specific assessment protocol, we analyze the results of the experiment, positive in many ways, by comparing the results of the students involved and student control groups.Depuis 25 ans, des évaluations nationales font apparaître des constats récurrents sur ce qu’ont acquis ou non les élèves en mathématiques en fin d’école primaire en France. On peut s’interroger sur les apports de ces résultats pour l’enseignement, et sur leurs impacts éventuels sur les pratiques des enseignants de sixième. Cela nous a conduit à formuler des hypothèses sur l’origine de ces constats et à concevoir un dispositif expérimental de formation d’enseignants de collège appelé « PACEM » dans lequel les évaluations standardisées ont un double statut, à la fois porteuses d’informations et outils de formation. Puis nous avons mis en place ce dispositif dont la visée explicite est l’amélioration des acquis des élèves des enseignants formés, dans le domaine des nombres et du calcul au début du collège.Cette thèse a pour objectif de décrire et d’analyser l’ensemble du dispositif du point de vue du chercheur. Après avoir questionné ce que peuvent apporter les évaluations standardisées nationales dans le domaine étudié, nous utilisons la théorie de l’activité et des outils de didactique des mathématiques que nous adaptons (Robert & Rogalski, 2002) pour formuler un certain nombre d’hypothèses de formation, sur le calcul mental, à développer avec les élèves en sixième. Dans un troisième temps, nous explorons comment le dispositif a été mis en œuvre, en nous distanciant de notre activité de concepteur et de formateur. Enfin, grâce à un protocole spécifique d’évaluation, nous analysons les résultats de l’expérimentation, positive à bien des égards, en comparant les résultats des élèves impliqués et des élèves de groupes témoins