Search results for "medium"
showing 10 items of 3746 documents
The flight feather moult pattern of the bearded vulture (Gypaetus barbatus)
2015
Moult is an extremely time-consuming and energy-demanding task for large birds. In addition, there is a trade-off between the time devoted to moulting and that invested in other activities such as breeding and/or territory exploration. Moreover, it takes a long time to grow a long feather in large birds, and large birds that need to fly while moulting cannot tolerate large gaps in the wing, but only one or two simultaneously growing feathers. As a consequence, large birds take several years to complete a full moult cycle, and they resume the moult process during suboptimal conditions. A clear example of this pattern is the Bearded Vulture (Gypaetus barbatus), which needs 2-3 years for chang…
The effect of abrasive pretreatment on the drying kinetics and phenolic compounds in goji berries ( Lycium barbarum L.)
2020
The paper investigated the effect of a physical surface abrasion of goji berries on drying kinetics and the evolution of phenolic compounds at 323, 333, and 343 K. A diffusion model was developed to describe the drying process. The effective diffusion coefficient estimated by the model ranged from 7.5 × 10–9 to 4.2 × 10–8 m2/s for cylinder and 2.0 × 10–9 to 1.15 × 10–8 m2/s for sphere for untreated samples (UTR). Higher values were found for treated samples (TR) (from 2.50 × 10–8 to 1.20 × 10–7 m2/s for cylinder and 8.0 × 10–9 to 2.70 × 10–8 m2/s for sphere). For the UTR samples, the values of activation energy were found to be 79.5 and 80.8 kJ/mol, respectively, in the cylinder and sphere …
Towards understanding isotope variability in elephant ivory to establish isotopic profiling and source-area determination
2016
Abstract We present here new isotopic data (δ 13 C, δ 15 N, δ 18 O, δ 2 H, and δ 34 S) from pulverised ivory powder, measured by continuous flow isotope ratio mass spectrometry from an unprecedented large dataset of 507 ivory samples, derived from twenty-eight African and six Asian elephant range states. The aim of this study is to assess the accuracy of isotopic fingerprinting and to evaluate its forensic potential and limitations to predict the provenance of ivory of unknown origin. We constructed a nominal assignment framework for the African reference samples, consisting of 208 different sites and applied the weighted k -Nearest Neighbor Classifier with reference site as classifier and …
Melanism is related to behavioural lateralization in nestling barn owls.
2017
5 pages; International audience; Behavioural laterality is a commonly observed phenomenon in many species suggesting there might be an advantage of using dominantly one side over the other for certain tasks. Indeed, lateralized individuals were often shown to be more successful in cognitive tasks compared to non-lateralized conspecifics. However, stressed individuals are also often, but not always, more strongly lateralized. Because barn owl (Tyto alba) females displaying larger black spots on the tip of their ventral feathers produce offspring that are more resistant to a variety of environmental stressful factors, we examined whether laterality is associated with melanin-based coloration.…
Use of biochar as peat substitute for growing substrates of Euphorbia × lomi potted plants
2016
Biochar from conifers wood was used in soilless culture as growing substrate alternative to peat for ornamental crops. Potted plants of Euphorbia × lomi Rauh cv. ‘Ilaria’ were grown with different mixtures (v:v) of brown peat and biochar in order to evaluate main physical and chemical characteristics of this biomaterial as well as its effect on plant growth, ornamental characteristics and nutrients uptake. Biochar addition to peat increased pH, EC and K content of the growing substrates, as well as air content and bulk density. Biochar content of substrates significantly affected plant growth and biomass partitioning: higher number of shoots and leaves, leaf area and leaf dry weight were re…
Vegetation of feather grass steppes in the western Pamir Alai Mountains (Tajikistan, Middle Asia)
2016
Aims: To propose the first syntaxonomical scheme for the graminoid steppe vegetation of the montane and alpine zones in the Pamir-Alai Mts. in Tajikistan with some remarks on its environmental gradients. Location: Tajikistan. Methods: A total of 155 relevés were sampled in 2015 using the seven-degree cover-abundance scale of Braun-Blanquet and subsequently 148 of these relevés were selected and classified by the modified TWINSPAN method using the four step interval scale with cutoff levels of 0%, 5%, 10% and 25% and total inertia as a measure of cluster heterogeneity. Diagnostic species were identified using the phi coefficient as a fidelity measure. The detrended correspondance analysis wa…
Sucrose amendment enhances phytoaccumulation of the herbicide atrazine in Arabidopsis thaliana.
2006
International audience; Growth in the presence of sucrose was shown to confer to Arabidopsis thaliana (thale cress or mustard weed) seedlings, under conditions of in vitro culture, a high level of tolerance to the herbicide atrazine and to other photosynthesis inhibitors. This tolerance was associated with root-to-shoot transfer and accumulation of atrazine in shoots, which resulted in significant decrease of herbicide levels in the growth medium. In soil microcosms, application of exogenous sucrose was found to confer tolerance and capacity to accumulate atrazine in Arabidopsis thaliana plants grown on atrazine-contaminated soil, and resulted in enhanced decontamination of the soil. Applic…
Satellite survey of seasonal trophic status and occasional anoxic 'malaigue' crises in the Thau lagoon using MERIS images
2011
International audience; The Thau lagoon, located in southern France, suffers episodically from anoxic crises locally known as 'malaigue'. Such crises mostly occur under warm conditions, low winds leading to a strong eutrophication of the lagoon. The development of a sulphur bacterium sometimes gives locally to the waters a 'milky turquoise' appearance and leads to shellfish mortality. One of the indicators of the eutrophication status of the lagoon can be surveyed by the chlorophyll product provided by remote sensing images such as Medium Resolution Imaging Spectrometer (MERIS). In this paper we compare chl2 (or algal2) estimations provided by MERIS level 2 products and the ground measureme…
Stipa dickorei sp. nov. (Poaceae), three new records and a checklist of feather grasses of China
2016
Stipa dickorei sp. nov. from the Western Tibetan Plateau (China) is described. The new species is morphologically similar to S. regeliana, but they differ from each other in the length of ligules of vegetative shoots. Stipa dickorei is also similar to S. aliena, however they differ in the shape of panicle, which is contracted with straight branches in S. dickorei, and lax with flexuous branches in S. aliena. Images of macromorphological and micromorphological structures of the new taxon are provided. Additionally, new records of S. borysthenica, S. richteriana, and S. zalesskii, species not listed in the recent Flora of China, as well as a checklist of Chinese feather grasses are also prese…
Triterpene saponins of the root bark of Olax obtusifolia De Wild
2018
Abstract Four undescribed triterpenoid saponins together with five known and oleanolic acid were isolated from root bark of Olax obtusifolia De Wild. Their structures were elucidated by spectroscopic methods including 1D and 2D NMR experiments, in combination with mass spectrometry as 3-O-α- l -rhamnopyranosyl-(1→4)-α- l -rhamnopyranosyl-(1→3)-β- d -glucuronopyranosyloleanolic acid, 3-O-α- l -rhamnopyranosyl-(1→4)-α- l -rhamnopyranosyl-(1→3)-β- d -glucuronopyranosyloleanolic acid 28-O-β- d -glucopyranosyl ester, 3-O-α- l -rhamnopyranosyl-(1→3)-β- d -glucopyranosyl-(1→2)-[β- d -glucopyranosyl-(1→3)]-β- d -glucuronopyranosyloleanolic acid and 3-O-α- l -rhamnopyranosyl-(1→3)-β- d -glucopyranos…