Search results for "fishe"
showing 10 items of 2001 documents
Optimizing Hough transform for fertilizer spreading optical control
2006
International audience; In Europe, centrifugal spreading is a widely used method for agricultural soil fertilization. In this broadcasting method, fertilizer particles fall onto a spinning disk, are accelerated by a vane, and afterward are ejected into the field. To predict and control the spread pattern, a low-cost, embeddable technology adapted to farm implements must be developed. We focus on obtaining the velocity and the direction of fertilizer granules when they begin their flight by means of a simple imaging system. We first show that the outlet angle of the vane is a bounded value and that its measurement provides the outlet velocity of the particle. Consequently, a simple camera un…
[div]Long-term dynamics of the atrazine mineralization potential in surface and subsurface soil in an agricultural field as a response to atrazine ap…
2012
Abstract The dynamics of the atrazine mineralization potential in agricultural soil was studied in two soil layers (topsoil and at 35–45 cm depth) in a 3 years field trial to examine the long term response of atrazine mineralizing soil populations to atrazine application and intermittent periods without atrazine and the effect of manure treatment on those processes. In topsoil samples, 14 C-atrazine mineralization lag times decreased after atrazine application and increased with increasing time after atrazine application, suggesting that atrazine application resulted into the proliferation of atrazine mineralizing microbial populations which decayed when atrazine application stopped. Decay …
Microalgae community structure analysis based on 18S rDNA amplification from DNA extracted directly from soil as a potential soil bioindicator
2005
International audience; Soil algae are photosynthetically active microorganisms showing changeable community structure, depending on the soil type, the agricultural practices and the application of pesticides. To characterise algal community structure, molecular approaches complementary to classical microbiological approaches based on the isolation and the culture of soil algae are required. Our study describes a polymerase chain reaction (PCR) approach targeting algal 18S rDNA sequences of desoxyribonucleic acid (DNA) samples extracted either from unialgal eukaryotic microalgae culture, complex assemblages of microalgae populations or natural soil communities. Our first results showed that…
Enhanced isoproturon mineralisation in a clay silt loam agricultural soil
2005
International audience; 14C-ring-labelled isoproturon mineralisation was investigated in a French agricultural soil previously exposed to isoproturon. 50 different soil samples collected every 2 m along a transect of 100 m in length were treated one or two times with isoproturon under laboratory conditions and analysed by radiorespirometry. 94% of the soil samples showed a high ability to mineralise isoproturon with a relatively low variability in the cumulative percentage of mineralisation ranging from 30 to 51% of the initially added radioactivity for the samples treated once with the herbicide. About 45 to 67% of the initially added radioactivity was transformed into 14CO2 in soil sample…
Soil DNA evidence for altered microbial diversity after long-term application of municipal wastewater
2010
International audience; Water resources constitute a social, agricultural and economic problem in most countries of the southern Mediterranean Basin. Alternative strategies have been developed such as the reuse of municipal wastewater for irrigation in agriculture. Despite numerous advantages for soil fertility and crop productivity, recycling wastewater in soils also has several ecotoxicological and sanitary problems. Few investigations have assessed the risk by evaluating the impact of wastewater irrigation on soil microbes. Here, we report for the first time the short- and long-term effects of treated municipal wastewater irrigation on the density and genetic structure of bacterial and f…
Copper binding capacity of root exudates of cultivated plants and associated weeds
2001
International audience; Cu binding to root exudates of two cultivated plants, wheat (Triticum aestivum) and rape (Brassica napus), and two weeds associated with wheat, dog daisy (Matricaria inodora) and cornflower (Centaurea cyanus), was studied in vitro under hydroponic and sterile conditions. Nutrient solutions were prepared with or without P. A MetPLATE microbiological test was used to assess the metal complexing capacity of root exudates. In the P-deficient solutions, no exudation was observed for any of the four plants; consequently, no Cu binding occurred. When P was present in the nutrient solutions, the plant exudates displayed differing abilities to complex Cu. No difference was de…
Le théorème fondamental de la sélection naturelle de R. A. Fisher : une approche historique
1988
National audience
Performances of neural networks for deriving LAI estimates from existing CYCLOPES and MODIS products
2008
International audience; This paper evaluates the performances of a neural network approach to estimate LAI from CYCLOPES and MODIS nadir normalized reflectance and LAI products. A data base was generated from these products over the BELMANIP sites during the 2001-2003 period. Data were aggregated at 3 km x 3 km, resampled at 1/16 days temporal frequency and filtered to reject outliers. VEGETATION and MODIS reflectances show very consistent values in the red, near infrared and short wave infrared bands. Neural networks were trained over part of this data base for each of the 6 MODIS biome classes to retrieve both MODIS and CYCLOPES LAI products. Results show very good performances of neural …
Data from: Size-selective harvesting fosters adaptations in mating behavior and reproductive allocation, affecting sexual selection in fish
2019
1. The role of sexual selection in the context of harvest-induced evolution is poorly understood. However, elevated and trait-selective harvesting of wild populations may change sexually-selected traits, which in turn can affect mate choice and reproduction. 2. We experimentally evaluated the potential for fisheries-induced evolution of mating behavior and reproductive allocation in fish. 3. We used a unique experimental system of zebrafish (Danio rerio) lines exposed to large, small, or random (i.e. control) size-selective mortality. The large-harvested line represented a treatment simulating the typical case in fisheries where the largest individuals are preferentially harvested. We used …
Biostimulant Potential of Humic Acids Extracted From an Amendment Obtained via Combination of Olive Mill Wastewaters (OMW) and a Pre-treated Organic …
2018
Olive mill wastewaters (OMW) detain contain significant levels of phenolic compounds with antimicrobial/phytotoxic activity and high amounts of undecomposed organic matter that may a high pollutant load that exerts negative effects on soil biology because of significant levels in phenolic compounds with antimicrobial/phytotoxic activity and limited biodegradability, and high amounts of undecomposed organic matter. Among OMW detoxification techniques, those focusing on oxidative degradation of phenolic compounds are relevant those focusing on oxidative degradation of phenolic compounds to reduce their toxicity. The composting (bio-oxidation) process in particular, exploits exothermic oxidati…