Evaluating Potential for Water Quality Decline in Maine Lakes

Understanding lake vulnerability with respect to eutrophication and loss of water quality is important for sustainability of aquatic ecosystems. This project aims at identifying and quantifying the effects of relevant physiochemical, climate, and watershed characteristics on lake vulnerability in order to develop management decision tools for the Maine Department of Environmental Protection (MEDEP). In a changing chemical and physical environment, using independent variables from each of these categories and then relating them to the summer lake epilimnetic phosphorus (P) concentrations allows for development of models to inform stakeholders of lake vulnerability to eutrophication problems. We studied 24 lakes covering a range of trophic states (oligotrophic to mesotrophic) in Maine, USA. The lakes are classified as either dimictic or polymictic and may develop anoxic hypolimnia during stratification. Lake water samples were collected twice in June and August 2015, and analyzed for a variety of elements, with a primary focus on P. August epilimnetic P ranged from 1.9 to 21.0 µg/L (henceforth ppb). Sediment samples from the deepest point were collected in June 2015, and were sequentially extracted and analyzed for P, aluminum (Al), and iron (Fe). The results show that lakes with sediment having a NaOH-extractable Al to dithionite-reducible Fe ratio (AlNaOH:FeBD) \u3e 3 and a NaOH-extractable Al to dithionite-reducible P ratio (AlNaOH:PBD) \u3e 25 are less susceptible to internal P release, and have lower epilimnetic P concentrations. Ratios can thereby be used as sediment indicators for hypolimnetic P release under anoxic conditions. Three types of regression models (regression tree analysis, multiple linear regression (MLR), and quantile regression (QR)) were developed in order to broaden understanding of different aspects impacting lake eutrophication using data from the 24 study lakes that represented relevant lake physiochemical, climate, and watershed characteristics. A larger database of lakes from the Maine Department of Environmental Protection (96), and the Lake Environment Association (23) were then used to validate the models by analyzing the goodness of fit. The regression tree analysis was performed to detect dominant drivers in relation to the August epilimnetic P concentrations, revealing that to best predict the lake epilimnetic P, parameters representing physiochemical, climate and watershed characteristics are necessary independent variables. Of the approaches tested for MLR, the best fits to the observed data were obtained by one or more physiochemical variables and one watershed variable (R2 \u3e 0.78). Regression quantiles were used to estimate changes in epilimnetic P as a function of the agriculture area: watershed area (Ag:WA) ratio ranked by sediment AlNaOH:PBD and area depth (Zavg), all parameters that were shown to be important predictors in the MLR models. The structure of QR is robust for developing nutrient reduction targets for lake management. Using this approach, we determined that the reduction in Ag:WA to meet a specific epilimnetic P target (15 ppb) should be the first priority to mitigate eutrophication in Maine lakes. Using multiple regression models to identify and quantify factors that influence lake eutrophication allows us to classify susceptible lakes and inform stakeholders about appropriate practices for lake stewardship

Conditional Preference Nets and Possibilistic Logic

International audienceCP-nets (Conditional preference networks) are a well-known compact graphical representation of preferences in Artificial Intelligence, that can be viewed as a qualitative counterpart to Bayesian nets. In case of binary attributes it captures specific partial orderings over Boolean interpretations where strict preference statements are defined between interpretations which differ by a single flip of an attribute value. It respects preferential independence encoded by the ceteris paribus property. The popularity of this approach has motivated some comparison with other preference representation setting such as possibilistic logic. In this paper, we focus our discussion on the possibilistic representation of CP-nets, and the question whether it is possible to capture the CP-net partial order over interpretations by means of a possibilistic knowledge base and a suitable semantics. We show that several results in the literature on the alleged faithful representation of CP-nets by possibilistic bases are questionable. To this aim we discuss some canonical examples of CP-net topologies where the considered possibilistic approach fails to exactly capture the partial order induced by CP-nets, thus shedding light on the difficulties encountered when trying to reconcile the two frameworks

Influenza A virus surveillance, infection and antibody persistence in snow geese (Anser caerulescens)

Some snow geese (Anser caerulescens) migrate between Eurasia and North America and exhibit high seroprevalence for influenza A viruses (IAVs). Hence, these birds might be expected to play a role in intercontinental dispersal of IAVs. Our objective in this manuscript was to characterize basic incidence and infection characteristics for snow geese to assess whether these birds are likely to significantly contribute to circulation of IAVs. Thus, we 1) estimated snow goose infection prevalence by summarizing \u3e 5,000 snow goose surveillance records, 2) experimentally infected snow geese with a low pathogenic IAV (H4N6) to assess susceptibility and infection dynamics and 3) characterized long-term antibody kinetics. Infection prevalence based on surveillance data for snow geese was 7.88%, higher than the infection rates found in other common North American goose species. In the experimental infection study, only 4 of 7 snow geese shed viral RNA. Shedding in infected birds peaked at moderate levels (mean peak 102.62 EID50 equivalents/mL) and was exclusively associated with the oral cavity. Serological testing across a year post-exposure showed all inoculated birds seroconverted regardless of detectable shedding. Antibody levels peaked at 10 days post-exposure and then waned to undetectable levels by 6 months. In sum, while broad-scale surveillance results showed comparatively high infection prevalence, the experimental infection study showed only moderate susceptibility and shedding. Consequently, additional work is needed to assess whether snow geese might exhibit higher levels of susceptibility and shedding rates when exposed to other IAV strains

Intercropping Promotes the Ability of Legume and Cereal to Facilitate Phosphorus and Nitrogen Acquisition through Root- Induced Processes

Intercropping of cereal and legume can improve the use of resources for crop growth compared to cropping system. An increase in soil phosphorus (P) and nitrogen (N) acquisition by root-induced biochemical changes of intercropped species has been reported as key processes of facilitation and complementarily between both intercropping legumes and cereals. Indeed, the functional facilitation prevails over interspecific competition under nutrients limiting for crop growth. Results showed that P availability significantly increased in the rhizosphere of both species, especially in intercropping under the P-deficient soil conditions. This increase was associated with high efficiency efficiency in use of rhizobial, plant growth and resource use efficiency as indicated by higher land equivalent ratio (LER) and N nutrition index. In addition, the rhizosphere P availability and nodule biomass were positively correlated (r2 = 0.71**, and r2 = 0.62**) in the intercropped common bean grown at P-deficient soil. The increased P availability presumably improved biomass and yield in intercropping, although it mainly enhanced intercropped maize grain yield. Exploiting belowground parameters in a legume-cereal intercropping is likely necessary to maximize rhizosphere-interspecific interactions as a strategy to improve the symbiotic rhizobial efficiency and microbial activities, as a result of root-induced pH and N availability changes under low P soils

Effect of an amino acid additive on bovine milk production

En vue d’une évaluation de l’influence d’un additif alimentaire sur les performances de production chez la vache laitière, deux lots (témoin et expérimental) homogènes, sur base du stade de lactation et de l’état sanitaire, ont été constitués pour une période de deux mois. Le lot témoin recevait une ration alimentaire standard alors que la ration du lot expérimental était supplémentée à l’aide d’un additif alimentaire comportant des acides aminés et quelques oligoéléments. Les niveaux de production et la qualité du lait des deux groupes ont été comparés. Les résultats du contrôle laitier ont révélé une amélioration de la production laitière (18,0 kg du lait dans le lot expérimental vs 17.5 kg dans le lot témoin), et des paramètres physico-chimiques du lait: taux protéique (taux butyreux, lactose, densité et extrait sec dégraissé). Seuls les taux protéique et de lactose ont présenté des différences significatives. Cet additif a permis d’améliorer la production quantitative et qualitative du lait. Mots clés: additifs alimentaires, production laitière, qualité du lait, quantité du lait, vache laitièreIn order to evaluate the influence of a feed additive on the production performance of dairy cows, two homogenous lots (control and experimental) on the basis of lactation number and sanitary state were compared for two-month. The control group received a standard ration while the experimental group was supplemented with an additive containing amino acids and some trace-element. The production levels and the quality of milk of the two groups were compared. The experimental group had higher milk production (18.0 vs 17.5 kg for the control group), and physicochimical parameters (protein level, butyrous level, lactose, density and fat free dry extract). However only protein level and lactose showed significant differences. This additive had improved the quantitative and qualitative production of milk. Key words: milk production, dairy cows, food additive, quantity of milk, quality of milk

Cell Migration in the Immune System: the Evolving Inter-Related Roles of Adhesion Molecules and Proteinases

Leukocyte extravasation into perivascular tissue during inflammation and lymphocyte homing to lymphoid organs involve transient adhesion to the vessel endothelium, followed by transmigration through the endothelial cell (EC) layer and establishment of residency at the tissue site for a period of time. In these processes, leukocytes undergo multiple attachments to, and detachments from, the vessel-lining endothelial cells, prior to transendothelial cell migration. Transmigrating leukocytes must traverse a subendothelial basement membrane en route to perivascular tissues and utilize enzymes known as matrix metalloproteinases to make selective clips in the extracellular matrix components of the basement membrane. This review will focus on the evidence for a link between adhesion of leukocytes to endothelial cells, the induction of matrix metalloproteinases mediated by engagement of adhesion receptors on leukocytes, and the ability to utilize these matrix metalloproteinases to facilitate leukocyte invasion of tissues. Leukocytes with invasive phenotypes express high levels of MMPs, and expression of MMPs enhances the migratory and invasive properties of these cells. Furthermore, MMPs may be used by lymphocytes to proteolytically cleave molecules such as adhesion receptors and membrane bound cytokines, increasing their efficiency in the immune response. Engagement of leukocyte adhesion receptors may modulate adhesive (modulation of integrin affinities and expression), synthetic (proteinase induction and activation), and surface organization (clustering of proteolyric complexes) behaviors of invasive leukocytes. Elucidation of these pathways will lead to better understanding of controlling mechanisms in order to develop rational therapeutic approaches in the areas of inflammation and autoimmunity

An Axiomatic Approach to Support in Argumentation

International audienceIn the context of bipolar argumentation (argumentation with two kinds of interaction, attacks and supports), we present an axiomatic approach for taking into account a special interpretation of the support relation, the necessary support. We propose constraints that should be imposed to a bipolar argumentation system using this interpretation. Some of these constraints concern the new attack relations, others concern acceptability. We extend basic Dung’s framework in different ways in order to propose frameworks suitable for encoding these constraints. By the way, we propose a formal study of properties of necessary support

Using Comparative Preference Statements in Hypervolume-Based Interactive Multiobjective Optimization

International audienceThe objective functions in multiobjective optimization problems are often non-linear, noisy, or not available in a closed form and evolutionary multiobjective optimization (EMO) algorithms have been shown to be well applicable in this case. Here, our objective is to facilitate interactive decision making by saving function evaluations outside the "interesting" regions of the search space within a hypervolume-based EMO algorithm. We focus on a basic model where the Decision Maker (DM) is always asked to pick the most desirable solution among a set. In addition to the scenario where this solution is chosen directly, we present the alternative to specify preferences via a set of so-called comparative preference statements. Examples on standard test problems show the working principles, the competitiveness, and the drawbacks of the proposed algorithm in comparison with the recent iTDEA algorithm

Modulation of host responses by oral commensal bacteria.

Immunomodulatory commensal bacteria are proposed to be essential for maintaining healthy tissues, having multiple roles including priming immune responses to ensure rapid and efficient defences against pathogens. The default state of oral tissues, like the gut, is one of inflammation which may be balanced by regulatory mechanisms and the activities of anti-inflammatory resident bacteria that modulate Toll-like receptor (TLR) signalling or NF-κB activation, or influence the development and activities of immune cells. However, the widespread ability of normal resident organisms to suppress inflammation could impose an unsustainable burden on the immune system and compromise responses to pathogens. Immunosuppressive resident bacteria have been isolated from the mouth and, for example, may constitute 30% of the resident streptococci in plaque or on the tongue. Their roles in oral health and dysbiosis remain to be determined. A wide range of bacterial components and/or products can mediate immunomodulatory activity, raising the possibility of development of alternative strategies for therapy and health promotion using probiotics, prebiotics, or commensal-derived immunomodulatory molecules

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal