2,056 research outputs found

    When Europe encounters urban governance: Policy Types, Actor Games and Mechanisms of cites Europeanization

    Get PDF
    This paper examines European Union (EU) causal mechanisms and policy instruments affecting the urban domain throughout the lenses of the Europeanization approach. Instead of looking at EU instruments that are formally/legally consecrated to cities, we use theoretical public policy analysis to explore the arenas and the causal mechanisms that structure the encounters between the EU and urban systems of governance. Policy instruments are related to policy arenas and in turn to different mechanisms of transmission thus originating a typology of European Policy Modes. The paper focuses on four different EU instruments in the in the macro-area of sustainable development and proposes potential game-theoretical models for each of them. In the conclusions we highlight the differences between this approach and the traditional analysis of EU urban policy, and suggest avenues for future empirical research based on typologies of policy instruments and modes of Europeanization

    Ovarian development and analysis of mating effects on ovary maturation of Diaphorina citri Kuwayama (Hemiptera: Psyllidae)

    Get PDF
    As many other insects with a restricted diet, the citrus psyllid Diaphorina citri Kuwayama, which vector the causing agent of the Huanglongbing, the bacteria Candidatus Liberibacter spp., is intimately associated with symbiotic microorganisms. These mutualist symbionts play a key role on their host nutritional ecology, and are vertically transmitted to the progeny. However, despite the role symbionts play on host development and reproduction, and the growing opportunities of exploitation of the association insect-symbiont to control insect vectored-pathogens, there are very few studies on the host reproductive biology and on the symbiont transovarial transmission. Therefore, we aimed at analyzing the ovary development during D. citri adulthood, and at verifying for the mating requirement as a trigger to initiate ovary development. Newly-emerged D. citri females were grouped as virgin or mated and ovary development was observed during adulthood. Newly-emerged females have immature ovaries, and ovaries remain without any mature eggs until females mate. Once female mates, the vitellogenesis synthesis and uptake are estimulated, and oocytes are quickly developed. Oocytes maturation in ovarioles is metachronic, with only one oocyte developing at a time in each oogenic cycle. Morphological observations of the reproductive system including the ovaries and spermatheca, after the first cluster of eggs is laid, indicated D. citri is polyandrous, and may require multiple mating to develop additional oogenic maturation cycles.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

    Novel modulatory effects of neurosteroids and benzodiazepines on excitatory and inhibitory neurons excitability: a multi-electrode array (MEA) recording study.

    Get PDF
    The dynamic equilibrium between glutamate- and GABA-mediated synaptic neurotransmission in the brain is fundamental to the control of nervous system function. Such a balance is regulated by the \u2018tonic\u2019 release of a variety of neurotransmitters and endogenous factors that influence synaptic function. One such important group of modulatory molecules are the neurosteroids (NSs) which, similarly to benzodiazepines (BDZs), enhance GABAergic neurotransmission. The purpose of our work was to investigate, at in-vivo physiologically relevant concentrations, the effects of these two classes of GABA modulators on dissociated neocortical neuron networks grown in long-term culture. We used a multi-electrode array (MEA) recording technique and a novel method of analysis that was able to both identify the action potentials of engaged excitatory and inhibitory neurons and to detect novel drug-induced network up-states (burst). We found that the NSs tetrahydrodeoxycorticosterone (THDOC) and allopregnanolone (ALLO) applied at low nanomolar concentrations, produced different modulatory effects on the two neuronal clusters. Conversely, at high concentrations (1 \ub5M), both NSs, decreased excitatory and inhibitory neuron cluster excitability; however, even several hours after washout, the excitability of inhibitory neurons continued to be depressed, leading to a network long term depression (LTD). The BDZs clonazepam (CLZ) and midazolam (MDZ) also decreased the network excitability, but only MDZ caused LTD of inhibitory neuron cluster. To investigate the origin of the LTD after MDZ application, we tested finasteride (FIN), an inhibitor of endogenous NSs synthesis. FIN did not prevent the LTD induced by MDZ, but surprisingly induced it after application of CLZ. The significance and possible mechanisms underlying these LTD effects of NSs and BDZs are discussed. Taken together, our results not only demonstrate that ex-vivo neuronal networks show a sensitivity to drugs comparable to that expressed in vivo, but also provide a new global in-vitro description of the physiological mode of action of NSs and BDZs that can help in understanding their activity in more complex systems

    Scintillation efficiency of liquid xenon for nuclear recoils with the energy down to 5 keV

    Full text link
    The scintillation efficiency of liquid xenon for nuclear recoils has been measured to be nearly constant in the recoil energy range from 140 keV down to 5 keV. The average ratio of the efficiency for recoils to that for gamma-rays is found to be 0.19+-0.02.Comment: 13 pages, 5 figure

    Role of Pressure and Aluminum Size in Solid Propellant CCP Generation

    Get PDF
    Aluminum combustion in solid propellants generates condensed products leaving the burning surface. The population of this particles is quite wide, spanning from smoke-oxide to molten metal drops. Their properties depend upon both intrinsic propellant features and combustion conditions (e.g. composition, microstructure, combustion pressure, and propellant burning rate). In propellants, aluminum is typically used in the shape of a micrometric powder. This class of energetic materials produces spherical agglomerates having the size between some tens to few hundreds of micrometers. When the metal fuel turns to nanometric, flake-kind aggregates emerge from the burning surface. Some macroscopic properties, such as the burning rate, are affected. This paper presents some results obtained from a set of aluminized propellants based on inert binder (hydroxylterminated polybutadiene) and ammonium perchlorate. The effect of both powder size and pressure is explored in terms of ballistics and condensed combustion residues. A nonstraightforward trend with pressure emerges when the condensed combustion products of propellants containing micro-aluminum and nano-aluminum are compared

    Contaminanti nello zooplancton

    Get PDF
    Not availableIndagini su DDT e sostanze pericolose nell\u27ecosistema del Lago Maggiore. Programma 2013-2015. Rapporto annuale 2014 - Contaminanti nello zooplancto

    Characterization of novel clonal murine endothelial cell lines with an extended life span

    Get PDF
    Summary: A murine endothelial cell line was recently established from microvessels that had invaded a subcutaneous sponge implant (Dong, Q. G.; Bernasconi, S.; Lostaglio, S., et al. Arterioscl. Thromb. Vasc. Biol. 17:1599-1604; 1997). From these sponge-induced endothelial (SIE) cells, we have isolated two subpopulations endowed with different phenotypic properties. Clone SIE-F consists of large, highly spread cells that have a relatively slow growth rate, form contact-inhibited monolayers, do not grow under anchorage-independent conditions, express elevated levels of thrombospondin-1 (TSP-1) and are not tumorigenic in vivo. In contrast, clone SIE-S2 consists of small, spindle-shaped cells that have a high proliferation rate, do not show contact-inhibition, grow under anchorage-independent conditions, express very low levels of TSP-1 and are tumorigenic in vivo. Both clones express the endothelial markers vascular endothelial-cadherin and vascular intercellular adhesion molecule-1, but do not express CD31 and E-selectin. In addition, SIE-S2 cells, but not SIE-F cells, express the α-smooth muscle actin isoform. SIE-S2 cells, but not SIE-F cells, are able to form branching tubes in fibrin gels. The SIE-F and SIE-S2 clones, which have properties of nontransformed and transformed cells, respectively, should provide useful tools to investigate physiological and pathological processes involving vascular endotheliu

    Analysis of building vulnerability and firebrand exposure to mitigate wildfire damage

    Get PDF
    Wildfire intensity and resulting damage to communities and infrastructure is increasing worldwide; this thesis investigates the vulnerability of wildland-urban interface (WUI) buildings to wildfires, focusing on firebrand exposure. The research objective is to improve understanding of wildfire damage mechanisms to aid effective risk reduction practices. A comprehensive literature review establishes the need for quantitative building vulnerability assessments and advanced understanding of firebrand deposition and accumulation around solid obstacles. To address these needs, a statistical analysis on two large wildfire damage databases from Portugal and California is conducted to investigate the relationship between building design and damage extent. The results contribute to the development of a preliminary building resistance index (WRI) to assess building vulnerability to wildfire damage. The thesis progresses to characterise the feasibility of using the Fire Dynamics Simulator (FDS) to simulate firebrand creep movement and accumulation around solid obstacles. A sensitivity analysis quantifies the impact of input parameters on final particle position, revealing a relationship between sensitivity and the Tachikawa number, which describes the aerodynamic properties of simulated particles. A comparison between two FDS Lagrangian Particle model modalities assesses their efficacy in simulating firebrand accumulation based on previously published experimental results. The analysis explain the connection between particulate transport physical mechanisms and the effective operational FDS use for simulating wildfire firebrand exposure. FDS simulations are subsequently conducted to identify regions of firebrand contact exposure, connected to firebrand ignition hazard, around three different obstacles mimicking common building components. Results characterize the combined influence of wind speed and obstacle geometry on firebrand contact exposure. Finally, the applicability of established sand protection measures to protect infrastructure from firebrands is explored by reviewing literature and conducting exploratory FDS simulations. The effectiveness of a trench protection measure to inhibit firebrand accumulation on an infrastructure component is investigated, indicating its potential when combined with contextual information on infrastructure design and ambient conditions.Open Acces
    corecore