How to enhance crop production and nitrogen fluxes? A result-oriented scheme to evaluate best agri-environmental measures in Veneto Region, Italy

The cost-effectiveness of adopting agri-environmental measures (AEMs) in Europe, which combine agricultural productions with reduced N losses, is debated due to poorly targeted site-specific funding that is allocated regardless of local variability. An integrated DAYCENT model-GIS platform was developed combining pedo-climatic and agricultural systems information. The aim was to evaluate best strategies to improve N fluxes of agro-ecosystems within a perspective of sustainable intensification. Indicators of agronomic efficiency and environmental quality were considered. The results showed that agronomic benefits were observed with a continuous soil cover (conservation agriculture and cover crops), which enhanced nitrogen use efficiency (+17%) and crop yields (+34%), although in some cases these might be overestimated due to modelling limitations. An overall environmental improvement was found with continuous soil cover and long-term change from mineral to organic inputs (NLeach 45 Mg ha 121), which were effective in the sandy soils of western and eastern Veneto with low SOM, improving the soil-water balance and nutrients availability over time. Results suggest that AEM subsidies should be allocated at a site-specific level that includes pedo-climatic variability, following a result-oriented approach

Les réseaux trophiques lacustres: structure, fonctionnement, interactions et variations spatio-temporelles

L'analyse comparative des réseaux trophiques lacustres est d'un grand intérêt pour le développement de la limnologie contemporaine et l'aménagement des lacs. L'analyse des mécanismes écologiques déterminant la structure et le fonctionnement des réseaux trophiques dans les lacs tempérés a permis l'émergence de plusieurs modèles, souvent contradictoires, et suscité d'intenses débats sur le rôle respectif des ressources et des prédateurs. Par contre, dans les lacs tropicaux, les études sont en majorité descriptives et la recherche de principes généraux et de concepts unificateurs y est rare. Cette synthèse présente l'état des connaissances, les approches méthodologiques, les modèles de régulation concernant la structure et le fonctionnement des réseaux trophiques lacustres. Les réseaux trophiques semblent varier selon un gradient de situations intermédiaires entre deux modèles extrêmes : (a) les milieux à cascades trophiques intenses et à effet atténué des ressources (lacs tempérés oligo-mésotrophes) caractérisés par la présence de poissons piscivores et de zooplancton herbivore de grande taille (tels Daphnia spp.) et (b) les milieux à régulation intermédiaire (lacs tempérés méso-eutrophes et la plupart des lacs tropicaux), caractérisés par la présence de poissons filtreurs microphages omnivores et de zooplancton herbivore de petite taille. Notre synthèse souligne aussi l'importance d'allier les approches expérimentales en enceintes ou par biomanipulation à des suivis à long terme et des modélisations pour avoir une bonne compréhension et des prédictions précises du fonctionnement des écosystèmes lacustres à différentes échelles spatiales et temporelles et pour différentes conditions climatiques, géographiques ou trophiques.Comparative analysis of lake food webs is a focal point of research in contemporary limnology and lake management. The study of ecological processes determining foodweb structure and function lead to the emergence of constrasting hypotheses and intense debates on the relative role of nutrients and food web structure in regulating temperate lake ecosystems. In contrast, studies in tropical lakes are in general descriptive and the search for integrate concepts and models is yet in development. This review paper presents an overview and a critical analysis of actual knowledge, methodological approaches, regulation models and controversies on foodweb structure and function in temperate and tropical lakes. Our synthesis suggests that the apparent diversity in models of lake foodwebs could reflect a gradient (or contiuum) of intermediate foodweb situations, regulated by various environmental factors. The differences among lakes could be related to three main biotic factors, independently of the climatic, geographical and trophic conditions: 1. the important cascading effect of strictly piscivorous fish in temperate lakes compared to the weak cascades induced by opportunistic omnivorous fish in tropical lakes, 2. the primacy of omnivory and opportunistic feeding behaviour of tropical fish, 3. the key role of herbivorous macrozooplankton (cladocerans, mostly Daphnia spp.) in temperate lakes where they are both selective preys of planktivorous fish and efficient grazers of nanophytoplankton, and 4. the synchronous reproduction of fish with seasonal plankton succession in temperate lakes, compared to continuous reproduction of fish and lack of seasonal coupling in tropical lakes. Consequently, food webs regulation ranges along a gradient of situations with two extreme models: 1. a model with intense cascading (top-down) regulation and attenuation of bottom-up effects typical of oligo-mesotrophic temperate lakes, characterized by the dominance of piscivorous fish and large herbivorous zooplankton (Daphnia spp.), and 2. a model with intermediate regulation encountered in eutrophic temperate lakes and most of tropical lakes, characterized par the dominance of filter omnivorous fish and small size zooplankton. Our synthesis also emphasizes the importance of coupling experimental approches in mesocosms or whole-lake biomanipulation with long-term monitoring and modelisation to fully understand and predict the functionning of lake ecosystems over different spatial and temporal scale

Mitigation of 42^{42}Ar/42^{42}K background for the GERDA Phase II experiment

Background coming from the $^{42}$Ar decay chain is considered to be one of the most relevant for the GERDA experiment, which aims to search of the neutrinoless double beta decay of $^{76}$Ge. The sensitivity strongly relies on the absence of background around the Q-value of the decay. Background coming from $^{42}$K, a progeny of $^{42}$Ar, can contribute to that background via electrons from the continuous spectrum with an endpoint of 3.5 MeV. Research and development on the suppression methods targeting this source of background were performed at the low-background test facility LArGe. It was demonstrated that by reducing $^{42}$K ion collection on the surfaces of the broad energy germanium detectors in combination with pulse shape discrimination techniques and an argon scintillation veto, it is possible to suppress the $^{42}$K background by three orders of magnitude. This is sufficient for Phase II of the GERDA experiment

Interplay between CCN1 and Wnt5a in endothelial cells and pericytes determines the angiogenic outcome in a model of ischemic retinopathy

CYR61-CTGF-NOV (CCN)1 is a dynamically expressed extracellular matrix (ECM) protein with critical functions in cardiovascular development and tissue repair. Angiogenic endothelial cells (ECs) are a major cellular source of CCN1 which, once secreted, associates with the ECM and the cell surface and tightly controls the bidirectional flow of information between cells and the surrounding matrix. Endothelium-specific CCN1 deletion in mice using a cre/lox strategy induces EC hyperplasia and causes blood vessels to coalesce into large flat hyperplastic sinuses with no distinctive hierarchical organization. This is consistent with the role of CCN1 as a negative feedback regulator of vascular endothelial growth factor (VEGF) receptor activation. In the mouse model of oxygen-induced retinopathy (OIR), pericytes become the predominant CCN1 producing cells. Pericyte-specific deletion of CCN1 significantly decreases pathological retinal neovascularization following OIR. CCN1 induces the expression of the non-canonical Wnt5a in pericyte but not in EC cultures. In turn, exogenous Wnt5a inhibits CCN1 gene expression, induces EC proliferation and increases hypersprouting. Concordantly, treatment of mice with TNP470, a non-canonical Wnt5a inhibitor, reestablishes endothelial expression of CCN1 and significantly decreases pathological neovascular growth in OIR. Our data highlight the significance of CCN1-EC and CCN1-pericyte communication signals in driving physiological and pathological angiogenesis

Single and Compound Knock-outs of MicroRNA (miRNA)-155 and Its Angiogenic Gene Target CCN1 in Mice Alter Vascular and Neovascular Growth in the Retina via Resident Microglia

The response of the retina to ischemic insult typically leads to aberrant retinal neovascularization, a major cause of blindness. The epigenetic regulation of angiogenic gene expression by miRNAs provides new prospects for their therapeutic utility in retinal neovascularization. Here, we focus on miR-155, a microRNA functionally important in inflammation, which is of paramount importance in the pathogenesis of retinal neovascularization. Whereas constitutive miR-155-deficiency in mice results in mild vascular defects, forced expression of miR-155 causes endothelial hyperplasia and increases microglia count and activation. The mouse model of oxygen-induced retinopathy, which recapitulates ischemia-induced aberrant neovessel growth, is characterized by increased expression of miR-155 and localized areas of microglia activation. Interestingly, miR-155 deficiency in mice reduces microglial activation, curtails abnormal vessel growth, and allows for rapid normalization of the retinal vasculature following ischemic insult. miR-155 binds to the 3'-UTR and represses the expression of the CCN1 gene, which encodes an extracellular matrix-associated integrin-binding protein that both promotes physiological angiogenesis and harnesses growth factor-induced abnormal angiogenic responses. Single CCN1 deficiency or double CCN1 and miR-155 knock-out in mice causes retinal vascular malformations typical of faulty maturation, mimicking the vascular alterations of miR-155 gain of function. During development, the miR-155/CCN1 regulatory axis balances the proangiogenic and proinflammatory activities of microglia to allow for their function as guideposts for sprout fusion and anastomosis. Under ischemic conditions, dysregulated miR-155 and CCN1 expression increases the inflammatory load and microglial activation, prompting aberrant angiogenic responses. Thus, miR-155 functions in tandem with CCN1 to modulate inflammation-induced vascular homeostasis and repair

The incidence of alien species on the taxonomic, phylogenetic, and functional diversity of lentic and lotic communities dominated by Phragmites australis (Cav.) Steud

This study aims to investigate, for the first time, the multiple diversity harbored in plant communities dominated by P. australis, discriminating between lentic and lotic habitats. We focused on the incidence of alien species on taxonomical, phylogenetic and functional diversity. Although it was hypothesized that ecological differences between habitats (lentic vs. lotic) could lead to plant adaptive trade-offs, results showed that the P. australis dominance affected overall plant diversity in the same way in both target habitats. Similarly, the two compared habitats hosted a similar alien species richness and relative abundance. Different results were observed based on whether the alien species richness or their relative abundance were considered regarding the incidence of alien species. Increasing alien species richness in lentic habitats resulted in increased taxonomic, phylogenetic and functional diversity. Instead, in lotic habitats, it promoted a decrease in taxonomic and functional diversity. In contrast, the increase in the relative abundance of alien species resulted in increased taxonomic, phylogenetic and functional diversity in both habitats. Choosing relative abundance vs richness of aliens in lotic stands can have a different impact in evaluating the effect of aliens on various components of diversity

Ideology, Grandstanding, and Strategic Party Disloyalty in British Parliament

Strong party discipline is a core feature of Westminster parliamentary systems. Parties typically compel Members of Parliament (MPs) to support the party position regardless of MPs' individual preferences. Rebellion, however, does occur. Using an original dataset of MP votes and speeches in the British House of Commons from 1992 to 2015, coupled with new estimations of MPs' ideological positions within their party, we find evidence that MPs use rebellion to strategically differentiate themselves from their party. The strategy that MPs employ is contingent upon an interaction of ideological extremity with party control of government. Extremists are loyal when their party is in the opposition, but these same extremists become more likely to rebel when their party controls government. Additionally, they emphasize their rebellion through speeches. Existing models of rebellion and party discipline do not account for government agenda control and do not explain these patterns