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showing 10 items of 22191 documents
Litter quality, land-use history, and nitrogen deposition effects on topsoil conditions across European temperate deciduous forests
2019
Topsoil conditions in temperate forests are influenced by several soil-forming factors, such as canopy composition (e.g. through litter quality), land-use history, atmospheric deposition, and the parent material. Many studies have evaluated the effects of single factors on physicochemical topsoil conditions, but few have assessed the simultaneous effects of multiple drivers. Here, we evaluate the combined effects of litter quality, land-use history (past land cover as well as past forest management), and atmospheric deposition on several physicochemical topsoil conditions of European temperate deciduous forest soils: bulk density, proportion of exchangeable base cations, carbon/nitrogen-rat…
Effects of Bacillus thuringiensis δ-Endotoxins on the Pea Aphid ( Acyrthosiphon pisum )
2009
ABSTRACT Four Bacillus thuringiensis δ-endotoxins, Cry3A, Cry4Aa, Cry11Aa, and Cyt1Aa, were found to exhibit low to moderate toxicity on the pea aphid, Acyrthosiphon pisum , in terms both of mortality and growth rate. Cry1Ab was essentially nontoxic except at high rates. To demonstrate these effects, we had to use exhaustive buffer-based controls.
Preface: Emerging trends in aquatic ecology II
2017
You are now consulting the celebratory volume 750 of Hydrobiologia, the international journal of aquatic sciences. The journal has, since its first volume in March 1948, now exactly 67 years ago, covered a lot of ground and has seen a lot of change in the landscape of scientific publishing in general, and in that of aquatic biodiversity in particular. It has evolved from a fairly locally managed journal, to an international journal with ever increasing impact and ranking. With an ISI 2013 Impact Factor of 2.212, it now ranks 32 out of 103 journals in ‘‘Marine and Freshwater Biology’’. But in the ‘‘Marine Sciences and Fisheries’’ Category of Google Scholar, Hydrobiologia ranks proudly at a 9…
Spatial heterogeneity and seasonal succession of phytoplankton functional groups along the vertical gradient in a mesotrophic reservoir
2017
Çelik, Kemal (Balikesir Author)
Energetic costs of size and sexual signalling in a wolf spider
1998
A prerequisite for honest handicaps is that there are significant condition–dependent costs in the expression of sexual traits. In the wolf spider Hygrolycosa rubrofasciata (Ohlert), sexual signalling (drumming) is costly in terms of increased mortality. Here we investigated whether this mortality may be caused by increased energy expenditure. During sexual signalling, metabolic rate was 22 times higher than at rest and four times higher than when males were actively moving. Metabolic rate per unit mass was positively related to absolute body mass during sexual signalling but not during other activities. This positive relationship is novel to any studies of metabolic rates. Indeed, it seems…
A morphological and mitochondrial assessment of Apis mellifera from Palermo, Italy
1998
A characterization of the honey bees from western Sicily (Palermo, Italy) is presented. Mor- phological comparisons to A. m. ligustica were made using data taken from honey bee populations from southeastern (Bari) and central (Emilia Romagna) Italy. The honey bees of the Palermo area have distinct morphological differences compared to the mainland honey bees. The mtDNA haplotype common in subspecies within the African lineage of A. mellifera predominated in the Sicilian honey bee samples (13 out of 16). These results suggest both the potential and the desirability to expend efforts to conserve A. m. sicula. © Inra/DIB/AGIB/Elsevier, Paris
The combined action of 9 lipoxygenase and galactolipase is sufficient to bring about programmed cell death during tobacco hypersensitive response
2005
International audience; Oxylipins, derived from fatty acid hydroperoxides (FAHs), are thought to play different roles during plant pathogen interactions. During hypersensitive response (HR) some of them serve as signals necessary for defence gene activation whereas others could contribute to pathogen killing or could participate in the execution of plant programmed cell death (PCD) associated with this resistance. In order to address the role of these compounds in the latter process, we have closely observed lipid peroxidation, the first step of this metabolic pathway, under different situations which led either to accelerated or inhibited HR cell death. The oxidative process has been studi…
Performance of a membrane-coupled high-rate algal pond for urban wastewater treatment at demonstration scale
2020
[EN] The objective of this study was to evaluate the performance of an outdoor membrane-coupled high-rate algal pond equipped with industrial-scale membranes for treating urban wastewater. Decoupling biomass retention time (BRT) and hydraulic retention time (HRT) by membrane filtration resulted in improved process efficiencies, with higher biomass productivities and nutrient removal rates when operating at low HRTs. At 6 days of BRT, biomass productivity increased from 30 to 66 and to 95 g.m(-3).d(-1) when operating at HRTs of 6, 4 and 2.5 days, respectively. The corresponding nitrogen removal rates were 4, 8 and 11 g N.m(-3).d(-1) and the phosphorous removal rates were 0.5, 1.3 and 1.6 g P…
From Metaphor to Practice: Operationalizing the Analysis of Resilience Using System Dynamics Modelling
2017
This paper operationalizes an analysis of resilience for social-ecological systems using system dynamics (SD) modelling. Resilience is a versatile concept that continues to gain popularity among researchers who study ways to reduce the vulnerability of social-ecological systems to a wide range of disturbances. However, its application in the policymaking domain still remains underdeveloped because it is difficult to understand the mechanisms that might enhance resilience and to measure the impact of potential policies. This paper proposes to use SD modelling as a tool to analyse resilience using simulations to quantify system response to disturbances and a causal analysis to identify ways t…
Priming: getting ready for battle
2006
International audience; Infection of plants by necrotizing pathogens or colonization of plant roots with certain beneficial microbes causes the induction of a unique physiological state called “priming.” The primed state can also be induced by treatment of plants with various natural and synthetic compounds. Primed plants display either faster, stronger, or both activation of the various cellular defense responses that are induced following attack by either pathogens or insects or in response to abiotic stress. Although the phenomenon has been known for decades, most progress in our understanding of priming has been made over the past few years. Here, we summarize the current knowledge of p…