766 research outputs found

    Counteracting cocaine production. An analysis based on a novel dataset

    Get PDF
    he debate about the effectiveness of the counteracting policies against the supply of drugs, in particular of cocaine, is very lively and intense. Indeed, since many opinions are based on certain measures rather than others, the construction of reliable indicators is one of the preconditions for a correct and concerted assessment of drug supply. The lack of reliable data on drug provision derives, on the one side, from the objective difficulties encountered in assessing the quantitative elements of drug production and drug trafficking due to its illegal nature, and, on the other side, from the lack of a standard methodological approach to the issue. This paper tries to contribute to the topic by proposing a new dataset, based on a completely new approach to the problem of measuring drug supply. We put forward a unique dataset covering cocaine related seizures in Colombia for the whole of year 2008. Data have been collected on a daily basis from the websites of the main organizations fighting against drug traffickers (Army, Air Force, National Police, Departamento Administrativo de Seguridad, Armada Nacional, Fiscalia), detailing each single seizure of laboratories for the production of both basic paste and cocaine hydrochloride. By means of this dataset, we offer some accounts of the main numbers on drug supply and on drug seizures, suggesting some policy options, and arriving to an estimate of cocaine production.

    Fractional Fourier detection of L\'evy Flights: application to Hamiltonian chaotic trajectories

    Full text link
    A signal processing method designed for the detection of linear (coherent) behaviors among random fluctuations is presented. It is dedicated to the study of data recorded from nonlinear physical systems. More precisely the method is suited for signals having chaotic variations and sporadically appearing regular linear patterns, possibly impaired by noise. We use time-frequency techniques and the Fractional Fourier transform in order to make it robust and easily implementable. The method is illustrated with an example of application: the analysis of chaotic trajectories of advected passive particles. The signal has a chaotic behavior and encounter L\'evy flights (straight lines). The method is able to detect and quantify these ballistic transport regions, even in noisy situations

    Emergence of a non trivial fluctuating phase in the XY model on regular networks

    Full text link
    We study an XY-rotor model on regular one dimensional lattices by varying the number of neighbours. The parameter 2γ12\ge\gamma\ge1 is defined. γ=2\gamma=2 corresponds to mean field and γ=1\gamma=1 to nearest neighbours coupling. We find that for γ<1.5\gamma<1.5 the system does not exhibit a phase transition, while for γ>1.5\gamma > 1.5 the mean field second order transition is recovered. For the critical value γ=γc=1.5\gamma=\gamma_c=1.5, the systems can be in a non trivial fluctuating phase for whichthe magnetisation shows important fluctuations in a given temperature range, implying an infinite susceptibility. For all values of γ\gamma the magnetisation is computed analytically in the low temperatures range and the magnetised versus non-magnetised state which depends on the value of γ\gamma is recovered, confirming the critical value γc=1.5\gamma_{c}=1.5

    Sticky islands in stochastic webs and anomalous chaotic cross-field particle transport by ExB electron drift instability

    Full text link
    The ExB electron drift instability, present in many plasma devices, is an important agent in cross-field particle transport. In presence of a resulting low frequency electrostatic wave, the motion of a charged particle becomes chaotic and generates a stochastic web in phase space. We define a scaling exponent to characterise transport in phase space and we show that the transport is anomalous, of super-diffusive type. Given the values of the model parameters, the trajectories stick to different kinds of islands in phase space, and their different sticking time power-law statistics generate successive regimes of the super-diffusive transport.Comment: This manuscript contains 13 Pages and 21 figure

    Unveiling the nature of out-of-equilibrium phase transitions in a system with long-range interactions

    Full text link
    Recently, there has been some vigorous interest in the out-of-equilibrium quasistationary states (QSSs), with lifetimes diverging with the number N of degrees of freedom, emerging from numerical simulations of the ferromagnetic XY Hamiltonian Mean Field (HMF) starting from some special initial conditions. Phase transitions have been reported between low-energy magnetized QSSs and large-energy unexpected, antiferromagnetic-like, QSSs with low magnetization. This issue is addressed here in the Vlasov N \rightarrow \infty limit. It is argued that the time-asymptotic states emerging in the Vlasov limit can be related to simple generic time-asymptotic forms for the force field. The proposed picture unveils the nature of the out-of-equilibrium phase transitions reported for the ferromagnetic HMF: this is a bifurcation point connecting an effective integrable Vlasov one-particle time-asymptotic dynamics to a partly ergodic one which means a brutal open-up of the Vlasov one-particle phase space. Illustration is given by investigating the time-asymptotic value of the magnetization at the phase transition, under the assumption of a sufficiently rapid time-asymptotic decay of the transient force field

    HUWE1 controls MCL1 stability to unleash AMBRA1-induced mitophagy

    Get PDF
    Receptor-mediated mitophagy is a crucial process involved in mitochondria quality control. AMBRA1 is a mitophagy receptor for the selective removal of damaged mitochondria in mammalian cells. A critical unresolved issue is how AMBRA1-mediated mitophagy is controlled in response to cellular stress. Here, we investigated the role of BCL2-family proteins on AMBRA1-dependent mitophagy and showed that MCL1 delays AMBRA1-dependent mitophagy. Indeed, MCL1 overexpression is sufficient to inhibit recruitment to mitochondria of the E3 Ubiquitin ligase HUWE1, a crucial dynamic partner of AMBRA1, upon AMBRA1-mediated mitophagy induction. In addition, we found that during mitophagy induced by AMBRA1, MCL1 levels decreased but were sustained by inhibition of the GSK-3β kinase, which delayed AMBRA1-mediated mitophagy. Also, we showed that MCL1 was phosphorylated by GSK-3β at a conserved GSK-3 phosphorylation site (S159) during AMBRA1-mediated mitophagy and that this event was accompanied by HUWE1-dependent MCL1 degradation. Altogether, our results demonstrate that MCL1 stability is regulated by the kinase GSK-3β and the E3 ubiquitin ligase HUWE1 in regulating AMBRA1-mediated mitophagy. Our work thus defines MCL1 as an upstream stress-sensitive protein, functional in AMBRA1-mediated mitophagy

    Correction to: HUWE1 controls MCL1 stability to unleash AMBRA1-induced mitophagy

    Get PDF
    An amendment to this paper has been published and can be accessed via a link at the top of the paper

    Syphilis with HIV in Florence, 2003-2009: a 7-year epidemiological study.

    Get PDF
    SUMMARYThe aims of this study were to describe the trend of acquired syphilis in the city of Florence and its province over a 7-year period, to investigate sexual behaviours in the syphilis-infected population and to analyse syphilis/HIV co-infection. A total of 259 patients were classified according to age, sex and HIV infection. We estimated that from 2004 to 2008 cases increased by 248%. Most patients with concurrent HIV infection were male (31–45 years), but 40- to 60-year-old men who had sex with men predominated in both male and HIV-positive patients. Oral sex was identified as the most significant route of transmission, although most patients did not consider it so. Late-presenters with HIV accounted for 33% of HIV-positive patients: they were unaware of their HIV status and showed syphilis lesions only. In these cases, syphilis heralded the presence of HIV infection and allowed earlier diagnosis

    Cardiovascular and renal effects of hyperuricaemia and gout.

    Get PDF
    A number of epidemiological studies have reported an association between serum uric acid levels and a wide variety of high-risk conditions including hypertension, insulin resistance, and kidney and cerebro-cardiovascular disease. All things considered, serum uric acid may induce cardiovascular and kidney events both directly and indirectly by promoting other well-known mechanisms of damage. While asymptomatic hyperuricemia is currently not considered to be an indication for urate lowering therapy, there is growing evidence indicating a linear relationship between pharmacological reduction in serum uric acid and incidence of cardiovascular and renal events
    corecore