2,772 research outputs found

    Shock structure in extended thermodynamics with second-order maximum entropy principle closure

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    An investigation on the features of the shock structure solution of the 13-moment system of extended thermodynamics with a second-order closure based on the maximum entropy principle is presented. The results are compared to those obtained by means of the traditional first-order closure and to those obtained in the framework of kinetic theory by solving the Boltzmann equation with a BGK model for the collision term. It is seen that when adopting a second-order closure, the strength of the subshock that appears in the shock structure profile for large enough Mach numbers is remarkably reduced with respect to what is found with the first-order closure, and the overall profile of the shock structure solution is in better agreement with the results obtained with the kinetic theory approach. The analysis is extended to the case of the 14-moment system of a polyatomic gas, and some preliminary results are presented also for this case

    Counterbalancing, Spatial Dependence, and Peer Group Effects

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    Previous studies identified several domestic factors that may influence a country?s level of structural coup-proofing, i.e., counterbalancing strategies that shall prevent internal groups from seizing power via a coup d?�tat. We suggest that a country?s level of counterbalancing is also affected by such policies in what we term countries? ?peer groups.? When deciding the appropriate level of counterbalancing, rulers may be affected by external information flows from a ?peer group? with similar structural coup-risk characteristics (institutions) or a similar coup-risk experience (coup history). Using maximum likelihood spatial lag models and data in 1976?2005, we find that leaders learn from and emulate counterbalancing in other states, but rather only through an ?experiential peer group.

    When and how children use explanations to guide generalizations

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    How to help young children ask better questions?

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    First-line erlotinib and fixed dose-rate gemcitabine for advanced pancreatic cancer

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    AIM: To investigate activity, toxicity, and prognostic factors for survival of erlotinib and fixed dose-rate gemcitabine (FDR-Gem) in advanced pancreatic cancer. METHODS: We designed a single-arm prospective, multicentre, open-label phase II study to evaluate the combination of erlotinib (100 mg/d, orally) and weekly FDR-Gem (1000 mg/m2, infused at 10 mg/m2per minute) in a population of previously untreated patients with locally advanced, inoperable, or metastatic pancreatic cancer. Primary endpoint was the rate of progression-free survival at 6 mo (PFS-6); secondary endpoints were overall response rate (ORR), response duration, tolerability, overall survival (OS), and clinical benefit. Treatment was not considered to be of further interest if the PFS-6 was < 20% (p0 = 20%), while a PFS-6 > 40% would be of considerable interest (p1 = 40%); with a 5% rejection error (α = 5%) and a power of 80%, 35 fully evaluable patients with metastatic disease were required to be enrolled in order to complete the study. Analysis of prognostic factors for survival was also carried out. RESULTS: From May 2007 to September 2009, 46 patients were enrolled (male/female: 25/21; median age: 64 years; median baseline carbohydrate antigen 19-9 (CA 19-9): 897 U/mL; locally advanced/metastatic disease: 5/41). PFS-6 and median PFS were 30.4% and 14 wk (95%CI: 10-19), respectively; 1-year and median OS were 20.2% and 26 wk (95%CI: 8-43). Five patients achieved an objective response (ORR: 10.9%, 95%CI: 1.9-19.9); disease control rate was 56.5% (95%CI: 42.2-70.8); clinical benefit rate was 43.5% (95%CI: 29.1-57.8). CA 19-9 serum levels were decreased by > 25% as compared to baseline in 14/23 evaluable patients (63.6%). Treatment was well-tolerated, with skin rash being the most powerful predictor of both longer PFS (P < 0.0001) and OS (P = 0.01) at multivariate analysis (median OS for patients with or without rash: 42 wk vs 15 wk, respectively, Log-rank P = 0.03). Additional predictors of better outcome were: CA 19-9 reduction, female sex (for PFS), and good performance status (for OS). CONCLUSION: Primary study endpoint was not met. However, skin rash strongly predicted erlotinib efficacy, suggesting that a pharmacodynamic-based strategy for patient selection deserves further investigation

    Langmuir-Schaefer films of a polyaniline-gold nanoparticle composite material for applications in organic memristive devices

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    Langmuir-Shaefer films of a polyaniline-gold nanoparticle composite were fabricated and characterized. The thickness of each deposited monolayer, determined with AFM, was found to be about 0.8 nm. The film morphology was studied by SEM, revealing the presence of embedded spherical-shaped gold nanoparticles of about 5-10 nm in diameter. The fabricated films were used as the active channel of the organic memristor. Its electric characterisation has revealed new phenomena, such as an increased working voltage range and sigmoidal voltage current characteristics that were connected to the charge trappin

    Linking the hydrodynamic and kinetic description of a dissipative relativistic conformal theory

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    We use the entropy production variational method to associate a one particle distribution function to the assumed known energy-momentum and entropy currents describing a relativistic conformal fluid. Assuming a simple form for the collision operator we find this one particle distribution function explicitly, and show that this method of linking the hydro and kinetic description is a non trivial generalization of Grad's ansatz. The resulting constitutive relations are the same as in the conformal dissipative type theories discussed in J. Peralta-Ramos and E. Calzetta, Phys. Rev. D {\bfseries 80}, 126002 (2009). Our results may prove useful in the description of freeze-out in ultrarelativistic heavy-ion collisions.Comment: v2: 23 pages, no figures, accepted in Phys. Rev.

    Exploring gender impact on collaborative care planning: insights from a community mental health service study in Italy

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    INTRODUCTION: Personal recovery is associated with socio-demographic and clinical factors, and gender seems to influence the recovery process. This study aimed to investigate: i) differences in the recovery goals of men and women users of a community mental health service in Italy; ii) any differences by gender in recovery over six months using the Mental Health Recovery Star (MHRS). METHODS: Service users and staff completed the MHRS together at recruitment and six months later to agree the recovery goals they wished to focus on. Socio-demographic and clinical characteristics and ratings of symptoms (BPRS), needs (CAN), functioning (FPS), and functional autonomy (MPR) were collected at recruitment and six months follow-up. Comparisons between men and women were made using t-tests. RESULTS: Ten women and 15 men completed the MHRS with 19 mental health professionals. Other than gender, men and women had similar socio-demographic, and clinical characteristics at recruitment. Women tended to choose recovery goals that focused on relationships whereas men tended to focus on work related goals. At follow-up, both men and women showed improvement in their recovery (MHRS) and women were less likely to focus on relationship related goals, perhaps because some had found romantic partners. There were also gains for both men and women in engagement with work related activities. Ratings of functional autonomy (MPR) improved for both men and women, and men also showed improvement in symptoms (BPRS) and functioning (FPS). CONCLUSIONS: Our findings suggest that collaborative care planning tools such as the MHRS can assist in identifying individualized recovery goals for men and women with severe mental health problems as part of their rehabilitation

    Optimization of an organic memristor as an adaptive memory element

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    The combination of memory and signal handling characteristics of a memristor makes it a promising candidate for adaptive bioinspired information processing systems. This poses stringent requirements on the basic device, such as stability and reproducibility over a large number of training/learning cycles, and a large anisotropy in the fundamental control material parameter, in our case the electrical conductivity. In this work we report results on the improved performance of electrochemically controlled polymeric memristors, where optimization of a conducting polymer polyaniline in the active channel and better environmental control of fabrication methods led to a large increase both in the absolute values of the conductivity in the partially oxydized state of polyaniline and of the on-off conductivity ratio. These improvements are crucial for the application of the organic memristor to adaptive complex signal handling networks

    Abiraterone acetate in metastatic castration-resistant prostate cancer after chemotherapy. A retrospective “Real Life” analysis of activity and safety

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    Abiraterone acetate (AA) is a potent, selective androge (CYP17) biosynthesis inhibitor, which showed to improve overall survival (HR = 0.646) in mCRPC patients progressing after docetaxel. In this retrospective analysis we assessed the safety and efficacy of AA in patients affected with mCRPC progressing after chemotherapy, treated in the normal clinical practice, in several Italian Oncologic Units, after the approval of the drug from the Italian Drug Agency (AIFA)
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