References of "Hoffmann, L"
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See detailContribution of violaxanthin, neoxanthin, phytoene and phytofluene to total carotenoid intake: Assessment in Luxembourg
Biehler, E; Hoffmann, L; Krause, E et al

in Journal of Food Composition and Analysis (2012), 25

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See detailStatistical Analysis of the night weather conditions favouring the epidemic of the brown rust in the Grand-Duchy of Luxemburg.
El Jarroudi, Moussa ULg; Tychon, Bernard ULg; Maraite, H. et al

in Italian Journal of Agronomy [=IJA] = Rivista di Agronomia (2008), 3(3), 611-612

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See detailMorphological and molecular characterization of planktonic cyanobacteria from Belgium and Luxembourg
Willame, R.; Boutte, C.; Grubisic, Stana ULg et al

in Journal of Phycology (2006), 42(6), 1312-1332

For the first time in Belgium and Luxembourg, the diversity and taxonomy of 95 cyanobacterial strains isolated from freshwater blooms were assessed by the comparison of phenotypes and partial 16S rRNA ... [more ▼]

For the first time in Belgium and Luxembourg, the diversity and taxonomy of 95 cyanobacterial strains isolated from freshwater blooms were assessed by the comparison of phenotypes and partial 16S rRNA gene sequences. The results showed the high diversity of nanoplanktonic, picoplanktonic, and benthic-periphytic cyanobacteria accompanying the main bloom-forming taxa. Indeed, besides 15 morphotypes of bloom-forming taxa, seven non-bloom-forming planktonic morphotypes and 11 morphotypes from benthic-periphytic taxa were isolated in culture from the plankton samples of 35 water bodies. The bloom-forming strains belonged to the genera Microcystis, Woronichinia, Planktothrix, Anabaena, and Aphanizomenon, whereas the other strains isolated from the same samples were assigned to the nanoplanktonic Aphanocapsa, Aphanothece, Snowella, and Pseudanabaena; to the picoplanktonic Cyanobium; and to the benthic periphytic Geitlerinema, Komvophoron, Leptolyngbya, Lyngbya, Phormidium, Calothrix, Nostoc, and Trichormus. The results supported both the polyphyletism of genera such as Aphanocapsa, Aphanothece, Leptolyngbya, Geitlerinema, Anabaena, and Aphanizomenon as well as the validity of genera such as Microcystis, Planktothrix, and Pseudanabaena with gas vesicles and cells constricted at the cross wall. The results obtained showed the close relationship between Snowella and Woronichinia for which very few sequences exist. The first sequence of Komvophoron appeared poorly related to other available cyanobacterial sequences. Although in a few cases a good agreement existed between phenotypic and genotypic features, there was generally a discrepancy. Strains with identical morphotypes show small differences in the 16S rRNA sequences, which might be related to the different chemical properties of their habitats. The results showed the importance of the polyphasic approach in order to improve the taxonomy of cyanobacteria. [less ▲]

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See detailRelationship between the progress of the foliar pathogens caused by Septoria tritici and the reduction of the photosynthetic vitality of plants in Grand-Duchy of Luxembourg in 2004.
El Jarroudi, Moussa ULg; Crumière, F.; Hausman, J.-F. et al

in Bibliotheca fragmenta agronomica - Book of proceedings (2006), 11(2), 643-644

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See detailForecasting Septoria tritici on winter wheat in the Grand-Duchy of Luxembourg from 2000 to 2005.
El Jarroudi, Moussa ULg; Tychon, Bernard ULg; Maraite, H. et al

in Bibliotheca Fragmenta Agronomica - Book of Proceedings (2006), 11(2), 751-752

This papers presents the results of a wheat diseases model called PROCULTURE for the prediction of septoriosis in the Grand Duchy of Luxembourg

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See detailInfluence of zooplankton stoichiometry on nutrient sedimentation in a lake system
Darchambeau, François ULg; Thys, I.; Leporcq, B. et al

in Limnology & Oceanography (2005), 50(3), 905-913

We explored rates and stoichiometry (C: N: P ratios) of sinking particles in a temperate reservoir during a 2-yr period. Plankton was sampled weekly, and a sediment trap placed below the metalimnion ... [more ▼]

We explored rates and stoichiometry (C: N: P ratios) of sinking particles in a temperate reservoir during a 2-yr period. Plankton was sampled weekly, and a sediment trap placed below the metalimnion collected sinking particles. There were no significant relationships between the stoichiometry of entrapped material and seston or zooplankton stoichiometry. However the differences in the entrapped C: P and N: P ratios between consecutive trap samplings were negatively correlated with the time variations of the zooplankton C: P and N: P ratios. Zooplankton C: P and N: P ratios were positively correlated with the percentage of copepod biomass in total zooplankton biomass > 250 mu m and negatively correlated with the percentage of cladocerans. Zooplankton biomass > 250 mu m reduced the fraction of N and P primary production lost to sinking (export ratio). The residuals of the N export ratio versus zooplankton biomass relationship were negatively correlated with the zooplankton N: P ratio, whereas there was a positive relationship with the residuals of the P export ratio relationship. These observations support the hypothesis that the regulation of elemental homeostasis in the herbivorous zooplankton consumers occurs at least partly at the assimilation/egestion level. Elements ingested in excess-P for the herbivorous copepods and N for many cladocerans-are concentrated into sinking feces, whereas the deficient elements are captured into biomass. [less ▲]

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See detailPotential of using Daphnia magna (crustacea) developing in an aerated waste stabilisation pond as a commercial source of chitin
Cauchie, Henry-Michel ULg; Versali, Marie-France ULg; Hoffmann, L. et al

in Aquaculture (2002), 205(1-2), 103-117

The potential of using the planktonic crustacean Daphnia magna as a commercial source of chitin was studied on the basis of the estimation of the amount of chitin produced annually by this species and the ... [more ▼]

The potential of using the planktonic crustacean Daphnia magna as a commercial source of chitin was studied on the basis of the estimation of the amount of chitin produced annually by this species and the specifications of this kind of chitin. D. magna was found to have a significant chitin content, ranging from 3% to 7% of the body dry weight. During three consecutive years, chitin biomass (B) and daily somatic chitin production (daily P-SOM) were monitored in a 59,000-m(2) aerated waste stabilisation pond located in the Grand-Duchy of Luxembourg (Western Europe). These variables were found to vary a lot seasonally. Maximum values were observed in summer (B > 40 kg chitin; daily P-SOM > 20 kg chitin day(-1)). Annual somatic chitin production reached on average 1200 kg chitin year(-1). The amount of chitin generated by the moulting of the daphnids (i.e. chitin contained in the exuviae) can also constitute a significant source of chitin, reaching about 1220 kg chitin year(-1). Chitin was isolated from D. magna, following three different processing routes. The specifications of the isolated and purified chitin were similar to those of commercial chitin extracted from crabs and shrimps. The average molecular weight varied from 600,000 to 2,600,000 depending on the processing route, The isolated chitin had a low N content indicating a high degree of acetylation. (C) 2002 Elsevier Science B.V. All rights reserved. [less ▲]

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See detailEffects of liming on forest soil algal communities
Kostinov, I.; Carnol, Monique ULg; Dulière, J.-F. et al

in Algological Studies (2001), 102

The effects of the application of dolomite lime (5 t ha-1) on soil algal communities were investigated in sessile oak (Quercus petraea (MATT.) LIEB.) and Norway spruce (Picea abies (L.) KARST.) plots ... [more ▼]

The effects of the application of dolomite lime (5 t ha-1) on soil algal communities were investigated in sessile oak (Quercus petraea (MATT.) LIEB.) and Norway spruce (Picea abies (L.) KARST.) plots situated in the Belgian Ardenne. Chlorophyta (60 taxa) were by far the most diverse group, followed by Xanthophyceae (10 taxa), Bacillariophyceae (3 taxa), Cyanophyceae (2 taxa) and Euglenophyceae (1 taxon). In both forest types, liming lead to a significant increase in soil pH, exchangeable magnesium and calcium. In the limed Quercus plots available phosphorus and soil solution nitrate concentrations were also increased. The soil algal diversity was similar in oak and spruce control plots and in limed spruce plots. However, in the limed oak plots a significantly higher algal diversity was observed. On the basis of a CCA analysis, three clusters of plots could be distinguished: a) Picea control plots, b) limed Picea and control Quercus plots, c) limed Quercus plots. Both soil pH and nutrient availability seem to be important in determining algal species composition in these forest soils. [less ▲]

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See detailChemical profiles of Amblystegium riparium, Fontinalis antipyretica and Rhynchostegium riparioides in the Grand-Duchy of Luxembourg
Vanderpoorten, Alain ULg; Ector, L.; Hoffmann, L.

in Nova Hedwigia (2000), 71(1-2), 209-221

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See detailMadangolide and Laingolide A, Two Novel Macrolides from Lyngbya bouillonii (Cyanobacteria)
Klein, D.; Daloze, D.; Hoffmann, L. et al

in Journal of Natural Products (1999)

Two new macrolide derivatives, madangolide (2) and laingolide A (3), have been isolated from the cyanobacterium Lyngbya bouillonii, collected in Papua New Guinea. Their structures (without stereochemistry ... [more ▼]

Two new macrolide derivatives, madangolide (2) and laingolide A (3), have been isolated from the cyanobacterium Lyngbya bouillonii, collected in Papua New Guinea. Their structures (without stereochemistry) have been established by detailed high-field 1D and 2D NMR studies and, in the case of 3, by comparison with the spectroscopic data of laingolide (1), previously isolated from the same organism. [less ▲]

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