3,100 research outputs found
Breaking Consensus, Transforming Metabolisms : Notes on direct-action against fossil fuels through Urban Political Ecology
This article discusses the politics of âdirect- actionâ against fossil fuels put forward by climate justice movements, focusing in particular on the tactic of the blockade. Drawing on the conceptual toolkit of Urban Political Ecology, the argument moves from a critique of the consensual regime of climate change governance to highlight conflict and dissent as central forces for the transformation of the socio-ecological metabolisms structuring the capitalist urbanization of natureâof which fossil fuels constitute the lifeblood. This approach shifts the debate around climate change politics from an issue of technological transition to one of metabolic transformation. On this basis, the article proposes a characterization of direct-action against fossil fuels as expressions of metabolic activism: instances of grassroots eco-political engagement that aim to break consensus by disrupting capitalist-driven metabolic relations while also experimenting with alternative values, knowledges, spaces, and socio-material relations. To ground these reflections, the article offers an account of the Swedish climate justice coalition FossilgasfĂ€llan and of its successful three-year campaign, culminated in a blockade, to halt the expansion of the gas terminal of Gothenburg port
Leaf and stem anatomy in eight Hypericum species (Clusiaceae)
Foliar micromorphology, epicuticular wax morphology and anatomical featuresof leaves and stem, particularly secondary xylem, were examined with light microscopy,general and histochemical staining and scanning electron microscopy in eightHypericum species. Outer tegument tissue and type of secondary xylem are determiningcharacteristics. Secondary xylem is ring-porous in H. perforatum, H. perfoliatum, H. tetrapterum, H. triquetrifolium, H. androsaemum and H. hircinum. In H. aegypticum and H. pubescens xylem is diffuse-porous, which is considered to be a more primitive type.These characteristics may be considered an additional criterion for species identification
Social Economy as Antidote to Criminal Economy: How Social Cooperation is Reclaiming Commons in the Context of Campaniaâs Environmental Conflicts
This article contributes to ongoing debates on how bottom-up social cooperation can halt and reverse processes of environmental and human degradation, dispossession and impoverishment, by proposing a synchronization of resistance and of commoning practices. The article moves from the empirical case of social and ecological conflicts currently unfolding in the so-called Land of Fires, an area in Southern Italy infamous for the socio-environmental impacts of two decades of waste disposal, mismanagement and contamination. Within this context, a coalition of grassroots movements is struggling to resist livelihoods degradation through an alliance with anti-Mafia social cooperatives. We provide an in-depth analysis of emerging social and economic networks that connect the strategies of grassroots movements for environmental justice with the work of social cooperatives that reclaim lands and assets confiscated to Mafia. The interests of environmental activists meet the interests of social cooperatives at the crossroad of territory reclamation with the spheres of social and economic production and reproduction. Framing the case as a cultural and physical re-appropriation of territory, we provide an analysis of strategies and limits for a symbolic and practical project of social re-appropriation of the commons
Towards weighing the condensation energy to ascertain the Archimedes force of vacuum
The force exerted by the gravitational field on a Casimir cavity in terms of
Archimedes force of vacuum is discussed, the force that can be tested against
observation is identified, and it is shown that the present technology makes it
possible to perform the first experimental tests. The use of suitable high-Tc
superconductors as modulators of Archimedes force is motivated. The possibility
is analyzed of using gravitational wave interferometers as detectors of the
force, transported through an optical spring from the Archimedes vacuum force
apparatus to the gravitational interferometer test masses to maintain the two
systems well separated. The use of balances to actuate and detect the force is
also analyzed, the different solutions are compared, and the most important
experimental issues are discussed.Comment: Revtex, 33 pages, 8 figures. In the final version, the title has been
changed, and all sections have been improved, while 2 appendices have been
adde
Protein clustering in chemically stressed HeLa cells studied by infrared nanospectroscopy
Photo-Thermal Induced Resonance (PTIR) nanospectroscopy, tuned towards amide-I absorption, was used to study the distribution of proteic material in 34 different HeLa cells, of which 18 were chemically stressed by oxidative stress with Na3AsO3. The cell nucleus was found to provide a weaker amide-I signal than the surrounding cytoplasm, while the strongest PTIR signal comes from the perinuclear region. AFM topography shows that the cells exposed to oxidative stress undergo a volume reduction with respect to the control cells, through an accumulation of the proteic material around and above the nucleus. This is confirmed by the PTIR maps of the cytoplasm, where the pixels providing a high amide-I signal were identified with a space resolution of âŒ300 Ă 300 nm. By analyzing their distribution with two different statistical procedures we found that the probability to find protein clusters smaller than 0.6 ÎŒm in the cytoplasm of stressed HeLa cells is higher by 35% than in the control cells. These results indicate that it is possible to study proteic clustering within single cells by label-free optical nanospectroscopy
Using Resources as Synchronizers to Manage Mobile Process Adaptation
Process management in Mobile Ad-hoc NETworks (MANETs) has to deal with different types of tasks and resources. Teams can be formed with specific goals, such as recognition of a damaged area for disaster assessment, where each member of a team is assigned some task to be performed according to some policy. However, in real situations, it is possible that task assignments and policies have to be revised due to different causes. In addition to typical causes for dynamic changes in adaptive workflows, mobility introduces some specific problems, e.g. the need for new connectivity-maintaining tasks, or reassignment of tasks originally for members who have become unreachable, or who have no sufficient resources to complete the original plan. As these modifications occur dynamically, it is difficult to manage them through hard-coded programs. Rather, we propose the use of a rule-based formalism, expressed in terms of multi-set rewriting. This supports a resource-centered view, in which both data-dependencies between tasks and plan-dependent ordering of tasks are expressed as production and consumption of resources of different types. In turn, rules are themselves seen as resources, so that they are prone to the same rewriting process, in order to redefine process schemas. The paper illustrates these notions and formalisms, and shows some cases of their application
A comparison of CMB Angular Power Spectrum Estimators at Large Scales: the TT case
In the context of cosmic microwave background (CMB) data analysis, we compare
the efficiency at large scale of two angular power spectrum algorithms,
implementing, respectively, the quadratic maximum likelihood (QML) estimator
and the pseudo spectrum (pseudo-Cl) estimator. By exploiting 1000 realistic
Monte Carlo (MC) simulations, we find that the QML approach is markedly
superior in the range l=[2-100]. At the largest angular scales, e.g. l < 10,
the variance of the QML is almost 1/3 (1/2) that of the pseudo-Cl, when we
consider the WMAP kq85 (kq85 enlarged by 8 degrees) mask, making the pseudo
spectrum estimator a very poor option. Even at multipoles l=[20-60], where
pseudo-Cl methods are traditionally used to feed the CMB likelihood algorithms,
we find an efficiency loss of about 20%, when we considered the WMAP kq85 mask,
and of about 15% for the kq85 mask enlarged by 8 degrees. This should be taken
into account when claiming accurate results based on pseudo-Cl methods. Some
examples concerning typical large scale estimators are provided.Comment: 9 pages, 7 figures. Accepted for publication in MNRA
Applying Algebraic Approaches for Modeling Workflows and their Transformations in Mobile Networks
In emergency scenarios we can obtain a more effective coordination among team members, each of them equipped with hand-held devices, through the use of workflow management software. Team members constitute a Mobile Ad-hoc NETwork (MANET), whose topology both influences and is influenced by the workflow. In this paper we propose an algebraic approach for modeling workflow progress as well as its modifications as required by topology transformations. The approach is based on Algebraic Higher-Order Nets and sees both workflows and topologies as tokens, allowing their concurrent modification
Optimal Regulation Criteria for Building Heating System by Using Lumped Dynamic Models
Abstract Energy efficiency of buildings has gained an important role with respect to possible energy saving policy measures, mainly for space heating demand which represents the dominant energy end-use. The present contribution addresses the problem of estimating building heating energy consumptions by using numerical models able to simulate the dynamic interaction between the building and the heating system. A dynamic numerical code in the Engineering Equation Solver (EES) is developed to simulate both building and heating system and the influence of heating system regulation criteria on different parameters (mainly energy saving and internal comfort) is investigated in an optimization perspective
ThreMA: Ontology-based Automated Threat Modelling for ICT Infrastructures
Threat Modelling allows defenders to identify threats to which the target system is exposed. Such a process requires a detailed infrastructure analysis to map threats to assets and to identify possible flaws. Unfortunately, the process is still mostly done manually and without the support of formally sound approaches. Moreover, Threat Modelling often involves teams with different levels of security knowledge, leading to different possible interpretation in the system under analysis representation. Threat modelling automation comes with two main challenges: (i) the need for a standard representation of models and data used in various stages of the process, establishing a formal vocabulary for all involved parties, and (ii) the requirement for a well-defined inference rule set enabling reasoning process automation for threat identification. The paper presents the ThreMA approach to automating threat modelling for ICT infrastructures, aiming at addressing the key automation issues through the use of ontologies. Specifically, a formal vocabulary for modelling an ICT infrastructure, a threat catalog and a set of inference rules needed to support the reasoning process for threat identification are provided. The proposed approach has been validated against actual significant case studies provided by different Stakeholders of the Italian Public Sector
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