172 research outputs found

    Price vs quantity in a duopoly supergame with nash punishments

    Get PDF
    We examine the endogenous choice between price and quantity behaviour in a duopoly supergame with product differentiation. We find that (i) if cartel profits are evenly split between firms, then only symmetric equilibria obtains; (i) if instead the additional profits available through collusion are split according to the Nash bargaining solution, there are parameter regions where all subgame perfect equilibria are asymmetric, with firms colluding in price-quantity supergames

    Frustrated extended Bose-Hubbard model and deconfined quantum critical points with optical lattices at the anti-magic wavelength

    Full text link
    The study of geometrically frustrated many-body quantum systems is of central importance to uncover novel quantum mechanical effects. We design a scheme where ultracold bosons trapped in a one-dimensional state-dependent optical lattice are modeled by a frustrated Bose-Hubbard Hamiltonian. A derivation of the Hamiltonian parameters based on Cesium atoms, further show large tunability of contact and nearest-neighbour interactions. For pure contact repulsion, we discover the presence of two phases peculiar to frustrated quantum magnets: the bond-order-wave insulator with broken inversion symmetry and a chiral superfluid. When the nearest-neighbour repulsion becomes sizeable, a further density-wave insulator with broken translational symmetry can appear. We show that the phase transition between the two spontaneously-symmetry-broken phases is continuous, thus representing a one-dimensional deconfined quantum critical point not captured by the Landau-Ginzburg-Wilson symmetry-breaking paradigm. Our results provide a solid ground to unveil the novel quantum physics induced by the interplay of non-local interactions, geometrical frustration, and quantum fluctuations.Comment: 7+3 pages, 3+3 figure

    Nightmare disorder and REM sleep behavior disorder in inflammatory arthritis: Possibility beyond neurodegeneration.

    Get PDF
    OBJECTIVES:To investigate the prevalence of REM sleep behavior disorder (RBD) in patients with inflammatory arthritis (IA) to ascertain if RBD could be an internal red flag signaling a fluctuating state of inflammation based on the theory of "protoconsciousness". MATERIALS & METHODS:One hundred and three patients with a confirmed diagnosis of IA were consecutively recruited. The patients underwent general (IA activity, functional status, laboratory tests) and neurological evaluations. A neurologist investigated RBD and REM sleep parasomnias in a semi-structured interview. Sleep quality was assessed with the Pittsburgh Sleep Quality Index, while the risk of obstructive sleep apnea syndrome (OSAS) was evaluated with the Berlin questionnaire. Beck Depression Inventory II and State-Trait Anxiety Inventory investigated depression and anxiety. RESULTS:Patients had a mean age of 53.7 ± 14.6 years, 65% were women; 57.3% were in a clinically active phase of IA. Two women fulfilled ICSD-3 criteria for RBD appearing 11 years after and 20 years before IA onset respectively. 31 patients scored positive for nightmare disorder (ND), 8 for recurrent isolated sleep paralysis. 65 (63.1%) patients reported poor sleep quality and 25 (24.3%) resulted at high risk for OSAS. 32 (31.0%) patients scored positively for depression or anxiety. CONCLUSIONS:The prevalence of RBD in patients with IA did not differ from that in the general population, whereas ND presented a 2-fold increased prevalence. Whether RBD can be considered a red flag signaling an internal danger remains an open question, while ND may be a new player in this intriguing relation

    Evaluation of the Catalytic Activity of Metal Phosphates and Related Oxides in the Ketonization of Propionic Acid

    Get PDF
    In recent years, the upgrading of lignocellulose bio-oils from fast-pyrolysis by means of ketonization has emerged as a frontier research domain to produce a new generation of biofuels. Propionic acid (PA) ketonization is extensively investigated as a model reaction over metal oxides, but the activity of other materials, such as metal phosphates, is mostly unknown. Therefore, PA ketonization was preliminarily investigated in the gas phase over both phosphates and oxides of Al, Zr, and La. Their catalytic activity was correlated to the physicochemical properties of the materials characterized by means of XRD, XRF, BET N2 porosimetry, and CO2- and NH3-TPD. Noteworthy, monoclinic ZrO2 proved to be the most promising candidate for the target reaction, leading to a 3-pentanone productivity as high as 5.6 h 121 in the optimized conditions. This value is higher than most of those reported for the same reaction in both the academic and patent literature

    Validation of a high-density microelectrode array for acute brain slice recordings

    Get PDF
    Microelectrode arrays (MEAs) are employed to study extracellular electrical activity in neuronal tissues. Nevertheless, commercially available MEAs provide a limited number of recording sites and do not allow a precise identification of the spatio-temporal characterization of the recorded signal. To overcome this limitation, high density MEAs (HDMEA), based on CMOS technology, were recently developed and validated on dissociated preparations. The platform enables extracellular electrophysiological recordings from 4096 electrodes arranged in a squared area of 2.7 mm x 2.7 mm with inter-electrode distance of 21 ÎĽm at a sampling rate of 7.7 kHz/electrode. Here, we demonstrate the performances of this HDMEA platform for the acquisition of electrophysiological activity from acute brain slices. The unique recording performances and the large recording area of the chip permit the observation of fast propagating activities involving multiple areas. In our experimental paradigm, epileptic-like discharges were induced by treating hippocampal slices with 4-aminopyridine and/ or bicuculline. The HDMEA allowed us to clearly identify epileptic foci and to describe the involvement of cortical and hippocampal circuitries in the generation of the epileptiform activity. Furthermore, the HDMEA can be coupled with conventional extracellular electrodes for both stimulation and recording, giving the opportunity to perform standard short- and long-term plasticity protocols. We also show that HDMEA can be used in combination with fluorescence live imaging techniques such as Voltage Sensitive Dye recordings. The combination of complementary methodologies supports the HDMEA platform validation and paves the way to detailed electrophysiological studies

    Large-scale, high-resolution electrophysiological imaging of field potentials in brain slices with microelectronic multielectrode arrays

    Get PDF
    Multielectrode arrays (MEAs) are extensively used for electrophysiological studies on brain slices, but the spatial resolution and field of recording of conventional arrays are limited by the low number of electrodes available. Here, we present a large-scale array recording simultaneously from 4096 electrodes used to study propagating spontaneous and evoked network activity in acute murine cortico-hippocampal brain slices at unprecedented spatial and temporal resolution. We demonstrate that multiple chemically induced epileptiform episodes in the mouse cortex and hippocampus can be classified according to their spatio-temporal dynamics. Additionally, the large-scale and high-density features of our recording system enable the topological localization and quantification of the effects of antiepileptic drugs in local neuronal microcircuits, based on the distinct field potential propagation patterns. This novel high-resolution approach paves the way to detailed electrophysiological studies in brain circuits spanning spatial scales from single neurons up to the entire slice network

    Metronomic Oral Vinorelbine: An Alternative Schedule in Elderly and Patients PS2 With Local/Advanced and Metastatic NSCLC Not Oncogene-addicted

    Get PDF
    The MILES and ELVIS studies showed that vinorelbine is one of the best options for elderly patients with advanced non-small-cell-lung cancer (NSCLC). Oral vinorelbine at standard schedule (60-80 mg/m2/weekly) has good activity in terms of response rates and progression-free survival. In recent years, a metronomic schedule of oral vinorelbine (40-50 mg/m2 three times a week, continuously) has been studied in phase II trials, especially in unfit and elderly patients. In the MOVE trial metronomic oral vinorelbine had a clinical benefit [partial response (PR)+stable disease (SD) >12 weeks] in 58.1% of patients with mild toxicity. On this basis, in 2017 we started a phase II study with metronomic oral vinorelbine in elderly (over 70 years) or unfit [Eastern Cooperative Oncology Group performance score (ECOG-PS) of 2] patients with locally/advanced and metastatic NSCLC. Primary aims were clinical benefit (PR+SD ≥6 months) and toxicity; secondary aims were progression-free survival and overall survival

    Clinical and dopaminergic imaging characteristics of the FARPRESTO cohort of trial-ready idiopathic rapid eye movement sleep behavior patients

    Get PDF
    Introduction: Idiopathic/isolated rapid eye movement (REM) sleep behavior disorder (iRBD) is considered the prodromal stage of alpha-synucleinopathies. Thus, iRBD patients are the ideal target for disease-modifying therapy. The risk FActoRs PREdictive of phenoconversion in iRBD Italian STudy (FARPRESTO) is an ongoing Italian database aimed at identifying risk factors of phenoconversion, and eventually to ease clinical trial enrollment of well-characterized subjects.Methods: Polysomnography-confirmed iRBD patients were retrospectively and prospectively enrolled. Baseline harmonized clinical and nigrostriatal functioning data were collected at baseline. Nigrostriatal functioning was evaluated by dopamine transporter-single-photon emission computed tomography (DaT-SPECT) and categorized with visual semi-quantification. Longitudinal data were evaluated to assess phenoconversion. Cox regressions were applied to calculate hazard ratios.Results: 365 patients were enrolled, and 289 patients with follow-up (age 67.7 & PLUSMN; 7.3 years, 237 males, mean follow-up 40 & PLUSMN; 37 months) were included in this study. At follow-up, 97 iRBD patients (33.6%) phenoconverted to an overt synucleinopathy. Older age, motor and cognitive impairment, constipation, urinary and sexual dysfunction, depression, and visual semi-quantification of nigrostriatal functioning predicted phenoconversion. The remaining 268 patients are in follow-up within the FARPRESTO project.Conclusions: Clinical data (older age, motor and cognitive impairment, constipation, urinary and sexual dysfunction, depression) predicted phenoconversion in this multicenter, longitudinal, observational study. A standardized visual approach for semi-quantification of DaT-SPECT is proposed as a practical risk factor for phenoconversion in iRBD patients. Of note, non-converted and newly diagnosed iRBD patients, who represent a trial-ready cohort for upcoming disease-modification trials, are currently being enrolled and followed in the FARPRESTO study. New data are expected to allow better risk characterization

    Heterogeneity of prodromal Parkinson symptoms in siblings of Parkinson disease patients.

    Get PDF
    A prodromal phase of Parkinson's disease (PD) may precede motor manifestations by decades. PD patients' siblings are at higher risk for PD, but the prevalence and distribution of prodromal symptoms are unknown. The study objectives were (1) to assess motor and non-motor features estimating prodromal PD probability in PD siblings recruited within the European PROPAG-AGEING project; (2) to compare motor and non-motor symptoms to the well-established DeNoPa cohort. 340 PD siblings from three sites (Bologna, Seville, Kassel/Goettingen) underwent clinical and neurological evaluations of PD markers. The German part of the cohort was compared with German de novo PD patients (dnPDs) and healthy controls (CTRs) from DeNoPa. Fifteen (4.4%) siblings presented with subtle signs of motor impairment, with MDS-UPDRS-III scores not clinically different from CTRs. Symptoms of orthostatic hypotension were present in 47 siblings (13.8%), no different to CTRs (p = 0.072). No differences were found for olfaction and overall cognition; German-siblings performed worse than CTRs in visuospatial-executive and language tasks. 3/147 siblings had video-polysomnography-confirmed REM sleep behavior disorder (RBD), none was positive on the RBD Screening Questionnaire. 173/300 siblings had <1% probability of having prodromal PD; 100 between 1 and 10%, 26 siblings between 10 and 80%, one fulfilled the criteria for prodromal PD. According to the current analysis, we cannot confirm the increased risk of PD siblings for prodromal PD. Siblings showed a heterogeneous distribution of prodromal PD markers and probability. Additional parameters, including strong disease markers, should be investigated to verify if these results depend on validity and sensitivity of prodromal PD criteria, or if siblings' risk is not elevated
    • …
    corecore