56 research outputs found
Cultivation and genetics of Artemisia annua L. for increased production of the antimalarial artemisinin
Malaria has been treated for over 350 years with quinine and quinine-derived drugs. However, in several areas of the world, some strains of the malarial parasite Plasmodium falciparum have developed resistance against these drugs. Recently, the World Health Organization (WHO) recommended the use of artemisinin-combination treatments (ACT) as the first-line treatment for multidrug-resistant falciparum malaria. The WHO estimates that current supplies of artemisinin are sufficient for only 30 million ACT, and is foreseeing the need for 130-220 million ACT in 2005 (WHO, 2004). Current research on the production of synthetic artemisinin-like compounds by the Roll Back Malaria project, pharmaceutical companies and academia resulted in a promising synthetic artemisinin-like compound (OZ277) which is currently undergoing phase I clinical trials. In about 5 years this drug is expected to be approved and made available to the public, however, meeting current global demands for ACT depends on the immediate availability of affordable artemisinin-derived drugs. This will involve expansion of the area under cultivation of Artemisia annua and improved methods of cultivation and processing of raw material, associated with more efficient methods for extraction and purification of artemisinin from plant material. This review addresses the agricultural, environmental and genetic aspects that may be useful in the successful large-scale cultivation of A. annua and for producing the antimalarial artemisinin in areas where it is urgently needed today. It also includes geographic aspects (latitude and altitude), which will help make decisions about crop establishment in tropical countries, and includes a list of Good Agricultural and Collection Practices for A. annu
Influence de couverts végétaux sut la qualité des raisins et des vins de Chasselas
Un essai de comparaison de couvertures végétales permanentes des inter-rangs a été mené de 2019 à 2021 au domaine expérimental d’Agroscope à Changins-Nyon (Vaud). Ont été comparés, à un témoin en non culture (sol nu), des couverts herbacés naturels ou semés, afin d’étudier leurs effets sur le comportement agronomique de la vigne et la qualité des raisins et des vins de Chasselas. En l’absence de contrainte hydrique, l’enherbement naturel ou semé de l’interligne n’a pas exercé d’influence prépondérante sur les composantes du rendement comme la fertilité des bourgeons, le poids des grappes et des baies, ni sur la vigueur des sarments par rapport au désherbage chimique du sol. La composition des baies (teneur en sucres, pH, acidité totale, acide tartrique et malique) à la vendange a été identique quel que soit l’entretien du sol. L’enherbement naturel et l’engazonnement de l’interligne avec des semis de couverts végétaux a entrainé une diminution de la teneur en azote assimilable des raisins par rapport à la non culture (sol nu). La teneur en NH 3 et en acides aminés primaires (a-aminés) des baies a été plus faible dans les variantes enherbées. A la dégustation, les vins issus des variantes enherbées ont présenté un bouquet plus discret et des notes d’amertume légèrement plus élevées que les vins issus de vignes conduites en non culture au sol. Les différences se sont essentiellement manifestées en 2 e et 3 e année d’expérimentation
Finite-element-method (FEM) model generation of time-resolved 3D echocardiographic geometry data for mitral-valve volumetry
INTRODUCTION: Mitral Valve (MV) 3D structural data can be easily obtained using standard transesophageal echocardiography (TEE) devices but quantitative pre- and intraoperative volume analysis of the MV is presently not feasible in the cardiac operation room (OR). Finite element method (FEM) modelling is necessary to carry out precise and individual volume analysis and in the future will form the basis for simulation of cardiac interventions. METHOD: With the present retrospective pilot study we describe a method to transfer MV geometric data to 3D Slicer 2 software, an open-source medical visualization and analysis software package. A newly developed software program (ROIExtract) allowed selection of a region-of-interest (ROI) from the TEE data and data transformation for use in 3D Slicer. FEM models for quantitative volumetric studies were generated. RESULTS: ROI selection permitted the visualization and calculations required to create a sequence of volume rendered models of the MV allowing time-based visualization of regional deformation. Quantitation of tissue volume, especially important in myxomatous degeneration can be carried out. Rendered volumes are shown in 3D as well as in time-resolved 4D animations. CONCLUSION: The visualization of the segmented MV may significantly enhance clinical interpretation. This method provides an infrastructure for the study of image guided assessment of clinical findings and surgical planning. For complete pre- and intraoperative 3D MV FEM analysis, three input elements are necessary: 1. time-gated, reality-based structural information, 2. continuous MV pressure and 3. instantaneous tissue elastance. The present process makes the first of these elements available. Volume defect analysis is essential to fully understand functional and geometrical dysfunction of but not limited to the valve. 3D Slicer was used for semi-automatic valve border detection and volume-rendering of clinical 3D echocardiographic data. FEM based models were also calculated. METHOD: A Philips/HP Sonos 5500 ultrasound device stores volume data as time-resolved 4D volume data sets. Data sets for three subjects were used. Since 3D Slicer does not process time-resolved data sets, we employed a standard movie maker to animate the individual time-based models and visualizations. Calculation time and model size were minimized. Pressures were also easily available. We speculate that calculation of instantaneous elastance may be possible using instantaneous pressure values and tissue deformation data derived from the animated FEM
Beneficial insects in agricultural landscapes: faunal, ecological and functional contributions of recent studies in the canton of Geneva (Switzerland)
Description of the subject. In the context of biodiversity maintenance in agricultural environments and of risk reduction related to the use of phytosanitary products, it seems essential to improve our knowledge of the beneficial insects that develop in these ecosystems.Objectives. This article reviews the state of knowledge regarding insect auxiliaries and highlights the main faunal, ecological and functional contributions from recent studies carried out in an agricultural context in Geneva.Method. Data were collected from 2014 to 2019 on several families of predatory and pollinating auxiliaries in various agricultural contexts (extensive grasslands, vineyards, orchards, rapeseed crops, vegetable crops) using Barber, Malaise and emergence traps.Results. 48,921 individual records were collected belonging to 477 species of the main families of auxiliaries. Of these, four species were observed for the first time in Switzerland and 50 in the canton of Geneva. 357 (+/- 75%) of the species had a predatory stage and 103 (+/- 22%) could be regarded as valuable crop auxiliaries. The use of emergence traps made it possible to attest that at least a third of the species, including some rare or threatened species, are able to successfully carry out their life cycles within agricultural environments or to use them as overwintering sites.Conclusions. This review increases our understanding of the composition of the biodiversity of agricultural environments, which constitutes a significant component of biodiversity in Switzerland and in neighboring countries. It also highlights the role of semi-natural habitats as extensive grasslands or inter-rows of vineyards in supporting the development of many rare and sometimes threatened species
Influence de l'enherbement viticole sur les Carabidae (Coleoptera) et intérêt potentiel pour le contrôle de certains ravageurs de la vigne
Ground cover influence on Carabidae (Coleoptera) populations and potential interest for bio-control of some vineyards pests. Description of the subject. This paper deals with carabid populations within vineyards. Objectives. The objectives were to evaluate the effects of ground cover management on carabid populations and to understand the potential of these beetles as predators of some grapevine pests. Method. Two vineyards, located in Geneva (Switzerland), were sampled with 60 pitfall traps. Observations were carried out from March to October 2014 and a botanical survey was carried out in June. Results. In total, 951 carabids belonging to 36 species were captured in the two vineyards. Bare ground and poor plant species treated with herbicides reduced the abundance of the ground beetles. On the other hand, ground covered with spontaneous vegetation, rather than a mixture of seeds, seemed to favor ground beetles throughout the sampling period. Conclusions. The peak activity of the potential predatory beetles corresponded to the occurrence of some vine pests. However, the most common carabid species captured had an omnivorous diet and a low potential for pest predation on viticulture
Ischémie : quand l’ECG ne nous dit pas tout [Ischemia : when the ECG do not tell us everything]
The electrocardiogram recording, when an acute coronary syndrome is suspected, is of paramount importance as the modifications of the ST segment confirms the diagnosis of STEMI (ST-elevation myocardial infarction) which needs immediate treatment, or NSTEMI (Non-ST elevation myocardial infarction). In case of NSTEMI, the invasive procedure is generally performed in the first 24 to 72 hours. However, one patient in four present an acute occluded artery at the time of the coronary angiography and this is associated with a worse outcome. In this article, we describe an emblematic case, discuss the worse outcome of these patients and explore some ways to prevent this problem
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