Search results for "init"
showing 10 items of 6629 documents
Multiple-stressor effects of warming and acidification on the embryonic development of an estuarine fiddler crab
2021
Made available in DSpace on 2021-06-25T10:56:04Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-06-05 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Predicted effects of anthropogenic climate change on estuarine and coastal organisms are complex, and early life history stages of calcified ectotherms are amongst the most sensitive groups. Despite the importance of understanding their vulnerability, we lack information on the effects of multiple stressors on the embryonic development of estuarine and burrowing organisms, mainly mangrove-associated species. Here, we determined the combined effects of elevated temperature and decreased pH on the embryonic development of th…
Effect of NaCl road salt on the ionic composition of soils and Aesculus hippocastanum L. foliage and leaf damage intensity.
2021
AbstractWe investigated the accumulation of sodium chloride in roadside soils and common horse chestnut Aesculus hippocastanum L. under urban conditions to evaluate changes in soil and leaf ionic content and their relationship with foliar damage, considering the visual assessment of trees of the same health status. A total of 15 field sites were assessed in late June 2016. The analysis included soil granulometric composition, pH, electrical conductivity, and the content of Cl−, Na+, K+, Ca2+, and Mg2+ ions in soil and foliage samples. The results showed increased salinity and alkalization of roadside soils together with the decreased magnesium content. Foliage samples manifested significant…
Responses of a native plant species from invaded and uninvaded areas to allelopathic effects of an invader
2019
Invaders exert new selection pressures on the resident species, for example, through competition for resources or by using novel weapons. It has been shown that novel weapons aid invasion but it is unclear whether native species co‐occurring with in‐ vaders have adapted to tolerate these novel weapons. Those resident species which are able to adapt to new selective agents can co‐occur with an invader while others face a risk of local extinction. We ran a factorial common garden experiment to study whether a native plant species, Anthriscus sylvestris, has been able to evolve a greater tolerance to the allelochemicals exerted by the invader, Lupinus polyphyllus. Lupinus polyphyllus produces …
Reproductive strategy as a piece of the biogeographic puzzle: a case study using Antarctic sea stars (Echinodermata, Asteroidea)
2017
13 pages; International audience; AimTo describe and analyse asteroid biogeographic patterns in the Southern Ocean (SO) and test whether reproductive strategy (brooder versus broadcaster) can explain distribution patterns at the scale of the entire class. We hypothesize that brooding and broadcasting species display different biogeographic patterns.LocationSouthern Ocean, south of 45 °S.MethodsOver 14,000 asteroid occurrences are analysed using bootstrapped spanning network (BSN), non-metrical multidimensional scaling (nMDS) and clustering to uncover the spatial structure of faunal similarities among 25 bioregions.ResultsMain biogeographic patterns are congruent with previous works based on…
Different responses of coexisting Chara species to foreseeable Mediterranean temperature and salinity increases
2017
Abstract An increase in temperature of approximately 4 °C is expected to occur in the Mediterranean by the end of the century. Concomitant to this warming, a foreseeable rise in salinity will affect aquatic species. We addressed the effects of warming and salinity, and their interaction on three coexisting characean species (Chara aspera, C. hispida and C. vulgaris) from a Spanish Mediterranean interdunal pond (spring water temperature 20–23 °C, when charophytes re-grew; salinity 1.3–1.8 PSU). A laboratory experiment was designed with two levels of water temperature treatment (23 and 27 °C), plus two levels of salinity treatment (0.4 and 4.0 PSU). The variables considered were total length,…
Plant-Based Protein Hydrolysate Improves Salinity Tolerance in Hemp: Agronomical and Physiological Aspects
2021
Hemp (Cannabis sativa L.) is a multipurpose plant attracting increasing interest as a source for the production of natural fibers, paper, bio-building material and food. In this research we studied the agronomical performance of Cannabis sativa cv. Eletta Campana irrigated with saline water. Under those conditions, we tested the effect of protein hydrolysate (PH) biostimulant application in overcoming and/or balancing deleterious salinity effects. The results of the diverse treatments were also investigated at the physiological level, focusing on photosynthesis by means of a chlorophyll a fluorescence technique, which give an insight into the plant primary photochemical reactions. Four sali…
Random Forest model and TRIX used in combination to assess and diagnose the trophic status of Bizerte Lagoon, southern Mediterranean
2016
International audience; A combined multimetric trophic index (TRIX) and the Random Forest (RF) model were used to characterize the trophic status of Bizerte Lagoon. The RF model was used to build a predictive model of chlorophyll a using physicochemical variables (nitrite, nitrate, ammonium, phosphate, oxygen, temperature and salinity) as predictors. The approach is based on physicochemical and biological parameters measured in samples collected twice weekly from January to December 2012 at one representative sampling station located at the lagoon center.The observed TRIX values vary from 5.18 to 6.12, reflecting waters ranging from moderate to poor quality with a high trophic level. The re…
Ocean Acidification and the Loss of Phenolic Substances in Marine Plants
2012
Rising atmospheric CO(2) often triggers the production of plant phenolics, including many that serve as herbivore deterrents, digestion reducers, antimicrobials, or ultraviolet sunscreens. Such responses are predicted by popular models of plant defense, especially resource availability models which link carbon availability to phenolic biosynthesis. CO(2) availability is also increasing in the oceans, where anthropogenic emissions cause ocean acidification, decreasing seawater pH and shifting the carbonate system towards further CO(2) enrichment. Such conditions tend to increase seagrass productivity but may also increase rates of grazing on these marine plants. Here we show that high CO(2) …
Seed oils as additives: penetration of triolein, methyloleate and diclofop-methyl in maize leaves
1992
Summary: Resume: Zusammenfassung Methyl ester derivatives of seed oils have a greater effect on graminicide efficacy than the parent oils. To explain this difference, we investigated the penetration of the radiolabelled oils, triolein (TRI) and methyl oleate (MEO), in maize leaves, and their influence on diclofop-methyl penetration. Over a period of 3 h 30% of applied TRI penetrated maize leaves, but no further penetration was observed. In contrast, MEO entry proceeded regularly to 72% over a period of 27 h. The amount of oil found in epicuticular wax (chloroform wash) was generally less than 4% of the recovered label, and was even lower (<1%) in ‘glossy 1’ hybrids which have no crystalline…
Toward reconstructing the evolution of advanced moths and butterflies (Lepidoptera: Ditrysia): an initial molecular study
2009
AbstractBackgroundIn the mega-diverse insect order Lepidoptera (butterflies and moths; 165,000 described species), deeper relationships are little understood within the clade Ditrysia, to which 98% of the species belong. To begin addressing this problem, we tested the ability of five protein-coding nuclear genes (6.7 kb total), and character subsets therein, to resolve relationships among 123 species representing 27 (of 33) superfamilies and 55 (of 100) families of Ditrysia under maximum likelihood analysis.ResultsOur trees show broad concordance with previous morphological hypotheses of ditrysian phylogeny, although most relationships among superfamilies are weakly supported. There are als…