Intraguild predation between lady beetles and lacewings: outcomes and consequences vary with focal prey and arena of interaction

Citation: Noppe, Christophe, J. P. Michaud, and Patrick De Clercq. 2012. “Intraguild Predation Between Lady Beetles and Lacewings: Outcomes and Consequences Vary With Focal Prey and Arena of Interaction.” Annals of the Entomological Society of America 105 (4): 562–71. https://doi.org/10.1603/AN11165.We examined reciprocal intraguild predation (IGP) and cannibalism among various combinations of Coleomegilla maculata DeGeer and Chrysoperla carnea Stephens larvae as they developed feeding on greenbugs, Schizaphis graminum Rondani, on sorghum plants in microcosms. Pairs of C. maculata larvae suppressed aphids better than pairs of C. carnea larvae or heterospecific larval pairs and yielded the highest rate of plant survival. IGP by C. carnea larvae occurred mostly in the first instar, whereas C. maculata larvae were more aggressive in later instars. Although C. carnea was the superior intraguild predator, winning 62.7% of contests in microcosms, this value increased to 88.9% when the experiment was repeated in petri dishes without plant material, regardless of whether greenbugs or eggs of Ephestia kuehniella Zeller were offered as focal prey. Provision in petri dishes of the sessile, higher quality prey (Ephestia) as opposed to greenbugs, improved the survival of solitary larvae and delayed cannibalism and IGP until later developmental stages in both species. Larvae of C. maculata that cannibalized took longer to develop and weighed less at pupation, independent of the arena or prey offered. Although larvae of C. carnea did not pay a cost for cannibalism or IGP in microcosms, there were some negative developmental effects of IGP in petri dishes, particularly on the Ephestia diet. These results illustrate how the plant, as a substrate, can mediate the strength of IGP interactions and how the relative suitability of the focal prey can influence both the timing and consequences of cannibalism and IGP

Sediment reworking by marine benthic species from the Gullmar Fjord (Western Sweden): Importance of faunal biovolume

In order to compare and quantify sediment reworking activities by different species/functional groups of macrofauna, a laboratory experiment was carried out with species from the Gullmarsfjord (Western Sweden). Monospecific communities of Amphiura filiformis, Echinocardium cordatum, Scalibregma inflatum and Abra nitida were introduced in experimental mesocosms, with identical densities (795 ind. m−2), for 10 days. Sediment reworking was studied by quantifying downward and upward movements of fluorescent inert tracers (luminophores). Luminophores with different colour were initially deposited both at the sediment surface and within the sediments. Population biomass and biovolume were also determined. Surface tracers reworking coefficients ranged from 0.6 to 2.2 cm2 y−1 and 0.9 to 4.1 y−1, respectively for the biodiffusive-like and non-local transports. Calculated biodiffusive-like coefficient was between 1.0 and 2.3 cm2 y−1 for the deep tracers. For both tracers, the E. cordatum population presented the highest reworking coefficients. Among the morphological and/or ethological parameters that could determine overall patterns of reworking and differences between species, results have shown a direct relationship between the apparent biodiffusive mixing and the biovolume of the individuals (Db=0.35 ⁎ Biovolume). This suggests that the biovolume of macrofauna may allow a rough estimate of the biodiffusive-like reworking intensity of particles deposited on the sediment surface

DUNE: The Dark Universe Explorer

Understanding the nature of Dark Matter and Dark Energy is one of the most pressing issues in cosmology and fundamental physics. The purpose of the DUNE (Dark UNiverse Explorer) mission is to study these two cosmological components with high precision, using a space-based weak lensing survey as its primary science driver. Weak lensing provides a measure of the distribution of dark matter in the universe and of the impact of dark energy on the growth of structures. DUNE will also include a complementary supernovae survey to measure the expansion history of the universe, thus giving independent additional constraints on dark energy. The baseline concept consists of a 1.2m telescope with a 0.5 square degree optical CCD camera. It is designed to be fast with reduced risks and costs, and to take advantage of the synergy between ground-based and space observations. Stringent requirements for weak lensing systematics were shown to be achievable with the baseline concept. This will allow DUNE to place strong constraints on cosmological parameters, including the equation of state parameter of the dark energy and its evolution from redshift 0 to 1. DUNE is the subject of an ongoing study led by the French Space Agency (CNES), and is being proposed for ESA's Cosmic Vision programme

Metaheuristic methods applied to the environmentally conscious optimization of wood-plastic composite

This paper addresses the optimization of the quality of wood plastic composites(WPC) designed for outdoor uses such as decking, taking into account theenvironmental impact during the life cycle of the product, from production to end oflife. In a context where several conflicting objectives must be satisfied simultaneouslyin the design process, meta-heuristic approaches provide efficient methods foroptimization. Particle swarm optimization (PSO) has been chosen here to solve acomplex problem in which physical properties such as creep and duration of load,water absorption and swelling, need to be improved with a limited impact onenvironment. This requires to get reliable information on material properties as relatedto its composition, environmental impacts through life cycle analysis (LCA), and toimplement this information through analytical or probabilistic models in the PSOalgorithm in order to obtain a set of optimal solutions for the composite. This papershows the feasibility of this approach, which can be generalized in the design of anytype of composite structures, provided objective functions can be specified

Optimisation multi-objectifs de propriétés d'un matériau par essaim particulaire : application aux composites à base de bois

L’optimisation multi-objectifs, appliquée aux propriétés d'un matériau, permet l'exploration de l'espace de recherche et l’obtention d’un ensemble de solutions Pareto-optimales. Un espace de recherche étant défini par des équations algébriques, des connaissances qualitatives et des algorithmes, il peut être modélisé dans un même système d'optimisation par essaim particulaire. Nous présenterons les principes de modélisation que nous illustrerons avec l'écoconception de composite bois-plastique

One Year of Grassland Vegetation Dynamics in Two Sheep-Grazed Agrivoltaic Systems

In agrivoltaic systems with solar fixed panels, the provision of ecosystem services by agricultural productions could be compromised due to very large changes in plant microclimate. But we still do not know properly the changes in grasslands ecosystem services. On two sheep-grazed sites located in lowland (Braize, Br) and upland (Marmanhac, Ma) grasslands of central France, we studied for one year the direct effects of various shading conditions induced by solar fixed panels on abiotic variables (light, water and soil temperature) and on vegetation (daily growth height, forage quantity and quality, number of species). Under exclosure of grazing, three treatments per site were set up, control (without solar-panel influence), inter-rows (variable influence) and panel (full influence). The results showed that light was reduced by 93% on average over the year in the shade of the panels with a cooler soil temperature of 2.6°C on Ma and 3.4°C on Br compared to the control. However, the soil moisture response varied between sites, depending on the different seasonal rainfall events and on soil texture. This resulted in 2.6 (Ma) to 3.2 (Br) times faster daily height growth and better forage quality. However, annual biomass production and species number showed no difference between the control and the panel. Only the inter-row treatment, which receives variable shading conditions throughout the day and seasons, shows variable biomass responses across sites. Experimental work will continue for several years in order to parameterise models to simulate the ecosystem services of agrivoltaic parks over the long term

Bilan et perspectives sur la gestion des eaux pluviales à la parcelle sur le territoire des Hauts-de-Seine Points forts, réticences et axes d'amélioration

National audienceIn 2005, the département' council of Hauts-de-Seine approved its sewer system master-plan for the next 15 years. In a highly urbanised context, the département conducts a voluntary policy for stormwater control aimed at reducing combined sewer overflow and the flooding risks. To improve the efficiency of its policy in the Hauts-de-Seine county, urban managers and sewer system owners' commitment is needed. Therefore, the département has developed several tools ta promote a consistent policy for sustainable stormwater management. After seven years, the département has wished ta initiate a review of its policy through a series of interviews of its partners: local authorities and developers. These interviews have shown that stormwater regulation rules are now included in most municipalities' sewer system regulation documents and land use plans. Although many new buildings and developments were exemplary, it seems that some reticence sometime remains about stormwater source control and also access in private estates for checking the stormwater collecting system. Continuing a strong and long-lasting policy as well as mproving stormwater source control will contribute to update our sewer system master-plan.En 2005, le conseil général des Hauts-de-Seine approuvait son schéma départemental d'assainissement (SDA) pour les 15 années suivantes. Dans un contexte fortement urbanisé, ce document définit une politique en matière de maîtrise des eaux pluviales ayant pour objectif la protection des milieux naturels et la réduction des inondations par débordement de réseaux. Conscient de la nécessité d'impliquer l'ensemble des acteurs de l'urbanisme et de l'assainissement pour garantir l'efficacité de sa politique sur le territoire des Hauts-de-Seine, le département a développé un panel d'outils pour promouvoir la cohérence des politiques relatives à la gestion durable des eaux pluviales. Aujourd'hui, à mi-parcours de la mise en oeuvre du SDA 2005-2020, le département a souhaité engager une démarche d'évaluation de sa politique en menant une série d'entretiens auprès de ses partenaires: collectivités et aménageurs. Ces enquêtes ont permis de mettre en évidence des résultats concrets en matière d'intégration par les collectivités des prescriptions de maîtrise des eaux pluviales dans les règlements d'assainissement et les documents d'urbanisme et le développement de plusieurs projets d'aménagement exemplaires, mais ont également souligné l'existence persistante de nombreux freins pour une mise en oeuvre efficace des techniques alternatives et des contrôles des ouvrages de gestion des eaux pluviales dans les parcelles privées. La poursuite d'une politique forte et pérenne ainsi que l'esquisse de plusieurs propositions d'amélioration en matière de gestion des eaux pluviales alimenteront l'actualisation du SD

A Role for the RNA Chaperone Hfq in Controlling Adherent-Invasive Escherichia coli Colonization and Virulence

Adherent-invasive Escherichia coli (AIEC) has been linked with the onset and perpetuation of inflammatory bowel diseases. The AIEC strain LF82 was originally isolated from an ileal biopsy from a patient with Crohn's disease. The pathogenesis of LF82 results from its abnormal adherence to and subsequent invasion of the intestinal epithelium coupled with its ability to survive phagocytosis by macrophages once it has crossed the intestinal barrier. To gain further insight into AIEC pathogenesis we employed the nematode Caenorhabditis elegans as an in vivo infection model. We demonstrate that AIEC strain LF82 forms a persistent infection in C. elegans, thereby reducing the host lifespan significantly. This host killing phenotype was associated with massive bacterial colonization of the nematode intestine and damage to the intestinal epithelial surface. C. elegans killing was independent of known LF82 virulence determinants but was abolished by deletion of the LF82 hfq gene, which encodes an RNA chaperone involved in mediating posttranscriptional gene regulation by small non-coding RNAs. This finding reveals that important aspects of LF82 pathogenesis are controlled at the posttranscriptional level by riboregulation. The role of Hfq in LF82 virulence was independent of its function in regulating RpoS and RpoE activity. Further, LF82Δhfq mutants were non-motile, impaired in cell invasion and highly sensitive to various chemical stress conditions, reinforcing the multifaceted function of Hfq in mediating bacterial adaptation. This study highlights the usefulness of simple non-mammalian infection systems for the identification and analysis of bacterial virulence factors

Uncovering atrophy progression pattern and mechanisms in individuals at risk of Alzheimer's disease

Alzheimer's disease is associated with pre-symptomatic changes in brain morphometry and accumulation of abnormal tau and amyloid-beta pathology. Studying the development of brain changes prior to symptoms onset may lead to early diagnostic biomarkers and a better understanding of Alzheimer's disease pathophysiology. Alzheimer's disease pathology is thought to arise from a combination of protein accumulation and spreading via neural connections, but how these processes influence brain atrophy progression in the pre-symptomatic phases remains unclear. Individuals with a family history of Alzheimer's disease (FHAD) have an elevated risk of Alzheimer's disease, providing an opportunity to study the pre-symptomatic phase. Here, we used structural MRI from three databases (Alzheimer's Disease Neuroimaging Initiative, Pre-symptomatic Evaluation of Experimental or Novel Treatments for Alzheimer Disease and Montreal Adult Lifespan Study) to map atrophy progression in FHAD and Alzheimer's disease and assess the constraining effects of structural connectivity on atrophy progression. Cross-sectional and longitudinal data up to 4 years were used to perform atrophy progression analysis in FHAD and Alzheimer's disease compared with controls. PET radiotracers were also used to quantify the distribution of abnormal tau and amyloid-beta protein isoforms at baseline. We first derived cortical atrophy progression maps using deformation-based morphometry from 153 FHAD, 156 Alzheimer's disease and 116 controls with similar age, education and sex at baseline. We next examined the spatial relationship between atrophy progression and spatial patterns of tau aggregates and amyloid-beta plaques deposition, structural connectivity and neurotransmitter receptor and transporter distributions. Our results show that there were similar patterns of atrophy progression in FHAD and Alzheimer's disease, notably in the cingulate, temporal and parietal cortices, with more widespread and severe atrophy in Alzheimer's disease. Both tau and amyloid-beta pathology tended to accumulate in regions that were structurally connected in FHAD and Alzheimer's disease. The pattern of atrophy and its progression also aligned with existing structural connectivity in FHAD. In Alzheimer's disease, our findings suggest that atrophy progression results from pathology propagation that occurred earlier, on a previously intact connectome. Moreover, a relationship was found between serotonin receptor spatial distribution and atrophy progression in Alzheimer's disease. The current study demonstrates that regions showing atrophy progression in FHAD and Alzheimer's disease present with specific connectivity and cellular characteristics, uncovering some of the mechanisms involved in pre-clinical and clinical neurodegeneration

Towards the development of ecosystem-based indicators of mangroves functioning state in the context of the EU water framework directive

European Water Framework Directive is enforced in five tropical French Oversea Territories where mangroves are present. Developing bioindication tools to support the ecosystem-based management approach of the Directive is needed. A series of expert workshops was organized and led to the proposal of a strategy and of an applied research program to develop bioindication tools. The proceedings of the workshops are presented as a case study, as this is the first time such an integrative ecosystem-based approach is proposed in mangroves, combining structural and functional aspects, from forest structure to benthic community functioning