Search results for "Pollen"
showing 10 items of 302 documents
Archäobotanik ˗ Pollenkörner und Makroreste. Von der Grabung ins Labor: Untersuchungsmethoden und Arbeitsweise
2019
Catalogue de l'exposition au parc archéologique de Belginum, du 12 mai au 3 novembre 2019; International audience
Efficacy of sublingual immunotherapy with grass allergens for seasonal allergic rhinitis: A systematic review and meta-analysis
2010
Background The benefit of sublingual immunotherapy (SLIT) with grass allergens for seasonal allergic rhinitis has been extensively studied, but data on efficacy are still equivocal. Objective To assess the effectiveness of SLIT with grass allergens in the reduction of symptoms and medication in patients with seasonal allergic rhinitis to grass pollen. Methods Computerized bibliographic searches of MEDLINE (1995-2010) were supplemented by hand searches of reference lists. Studies were included if they were double-blind randomized controlled trials (RCTs) comparing SLIT to placebo and if they included patients with history of allergy to grass pollen treated with natural grass pollen extracts.…
Potentiel bioarchéologique de l’analyse des micro‐fossiles non‐polliniques : résultats préliminaires issus de deux opérations d’archéologie préventive
2019
International audience; Les micro‐fossiles non polliniques (MNP) constituent un vaste groupe de bioindicateurs (propagules ou forme de résistance, entre autres) issus de différents organismes (champignons, algues, plancton, bactérie, animaux, végétaux etc.). Si leur analyse est désormais fréquente dans les études palynologiques menées dans les milieux naturels (lacs ou zones humides), les MNP sont encore peu exploités en contexte archéologique. Leur potentiel bioarchéologique reste à évaluer mais l’enjeu est grand tant les informations qu’ils peuvent apporter sont nombreuses aussi bien sur le plan paléoenvironnemental que paléoécologique, géoarchéologique ou taphonomique. L’éventail de site…
Ambrosia trifida L. in France: current distribution and ecological knowledge. Towards an eradication of the species?
2014
National audience; Giant ragweed (Ambrosia trifida L.) is an annual plant belonging to Asteraceae, originating from North America. It was introduced in France in the early twentieth century. Originally described as a ruderal plant, Ambrosia trifida was recently reported in agricultural areas (maize and soybean) in the region Midi-Pyrénées. Beyond the potential public health issue, this species is a major invasive weed in North America, its native area. That is why a question arises about the future trend of the species in France. Can we expect a low ability of the species to adapt the French habitats and land-uses, with a low probability of naturalization? Viceversa, should we consider lead…
Sensory analysis integrated by palynological and physicochemical determinations plays a key role in differentiating unifloral honeys of similar botan…
2015
Summary Myrtaceae honeys produced in Sierra Morena (southern Spain, Andalusia) are obtained from both Eucalyptus camaldulensis and Myrtus communis, and honeys can be easily confused when classified as they come from the same botanical family. The characterisation was intended on the basis of their physicochemical, sensory and palynological properties. Cluster analysis (CA) and principal component analysis (PCA) allowed us to make a distinction between two honey profiles. The first one corresponds to the European sensory profile described for Eucalyptus unifloral honeys. The second profile, which sensory characteristics are absolutely different, has not been previously described. Classificat…
Prolonged stigma and flower lifespan in females of the gynodioecious plant Geranium sylvaticum
2017
In gynodioecious plants females need a reproductive advantage over hermaphrodites to be maintained in the same population. Generally, three main proximate causes for a female advantage are considered: inbreeding avoidance, different resource allocation patterns, and differences in ecological interactions. A mechanism potentially causing a female advantage that is rarely discussed is a difference in floral longevity between the genders. Females may have a longer stigma lifespan than hermaphrodites, which can affect pollination. Stigma and flower lifespan are rarely documented in gynodioecious species, although it is a common observation in dioecious species that female plants flower longer t…
Alder pollen in Finland ripens after a short exposure to warm days in early spring, showing biennial variation in the onset of pollen ripening
2017
We developed a temperature sum model to predict the daily pollen release of alder, based on pollen data collected with pollen traps at seven locations in Finland over the years 2000–2014. We estimated the model parameters by minimizing the sum of squared errors (SSE) of the model, with weights that put more weight on binary recognition of daily presence or absence of pollen. The model results suggest that alder pollen ripens after a couple of warm days in February, while the whole pollen release period typically takes up to 4 weeks. We tested the model residuals against air humidity, precipitation and wind speed, but adding these meteorological features did not improve the model prediction …
Application of an immunoproteomic approach to detect anti-profilin antibodies in sera of paritaria judaica allergic patients
2011
Pollen from grasses, weeds, and trees constitutes one of the main sources of inhalant allergens frequently associated with seasonal patterns of allergic diseases. Pollen allergens show some analogies in the amino acids sequence which determine immunological similarity and cross reactivity. Parietaria judaica (P.j) pollen represents one of the main sources of allergens in the Mediterranean area and its major allergens have already been identified (Par j 1 and Par j 2). Recently, has been also described a minor allergen, profilin (Par j 3), an allergen present in pollen of trees, grasses and weeds. Allergenic plant profilins constitute a highly conserved family with sequence identities of 70%…
Estimation of the pollen and seed production of common ragweed in Europe
2007
International audience; Common ragweed (Ambrosia artemisiifolia L.) is an invasive weed of fieldcrops and human-disturbed habitats in Europe. As well as in its natural range (NorthAmerica), common ragweed is a threat to human health due to its abundant allergenicpollen release. Most studies have been focused on airborne pollen monitoring, but todate, no data have been available on precise individual plant pollen and seed productionrelated to plant traits growing in natural environment and on their corresponding sourceof variation. The aim of this study was to evaluate pollen and seed production of commonragweed plants in several populations in France. Seasonal pollen production per plantran…