125 research outputs found

    Cointegration Rank Test and Long Run Specification: A Note on the Robustness of Structural Demand Systems

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    Private demand systems provide a practical application for analyzing identification issues in cointegration analysis. The paper conducts Montecarlo simulation experiments of cointegrated demand systems by assuming non-separability of government consumption. This framework enables further to test the robustness of models under alternative empirical specifications in which the homogeneity restriction is assumed to hold. The results highlight that separability of utility function with respect to government spending and the over-inclusion of lagged dependent variables introduce important bias in identifying the long run demand system, while the model specification with homogeneity restriction perform better when the theoretical hypothesis is contained in the data.Length: 34 pagesNon-separable structural models, Demand systems, Homogeneity.

    University and inter-firm R&D collaborations: propensity and intensity of cooperation in Europe

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    This paper investigates the determinants of firms’ decision to cooperate in R&D with universities and the intensity of the cooperation effort, in relation to the engagement in inter-firm R&D collaborations. Using novel survey data for seven EU countries between 2007 and 2009, our analysis accounts for unobservable factors influencing R&D cooperation forms and addresses the main endogeneity issues. We find that internal knowledge, appropriability conditions and incoming spillovers explain large variation in the probability and in the intensity of R&D collaborations of European firms with universities (and comparably with unaffiliated companies)

    Firms’ exporting and importing activities: is there a two-way relationship?

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    The literature on firm heterogeneity and trade has highlighted that most trading firms tend to engage in both importing and exporting activities. This paper provides some evidence that helps understanding to what extent this is the result of a two-way relationship. Using firm-level data for a group of 27 Eastern European and Central Asian countries from the World Bank Business Environment and Enterprise Performance Survey (BEEPS) over the period 2002–2008, we estimate a bivariate probit model of exporting and importing. After controlling for size (and other firm-level characteristics) we find that firms’ exporting activity does not increase the probability of importing, while the latter has a positive effect on foreign sales. This effect is mainly channeled through an increase in firm productivity and product innovation

    Toxicity after moderately hypofractionated versus conventionally fractionated prostate radiotherapy: A systematic review and meta-analysis of the current literature

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    Background: Moderately hypofractionated radiotherapy (RT) currently represents the standard RT approach for all prostate cancer (PCa) risk categories. We performed a systematic review and meta-analysis of available literature, focusing on acute and late genitourinary (GU) and gastrointestinal (GI) adverse events (AEs) of moderate hypofractionation for localized PCa. Materials and methods: Literature search was performed and two independent reviewers selected the records according to the following Population (P) Intervention (I) Comparator (C) and Outcomes (O) (PICO) question: “In patients affected by localized PCa (P), moderately hypofractionated RT (defined as a treatment schedule providing a single dose per fraction of 3–4.5 Gy) (I) can be considered equivalent to conventionally fractionated RT (C) in terms of G > 2 GI and GU acute and late adverse events (O)?”. Bias assessment was performed using Cochrane Cochrane Collaboration's Tool for Assessing Risk of Bias. Results: Thirteen records were identified and a meta-analysis was performed. Risk of acute GI and GU > 2 adverse events in the moderately hypofractionated arm was increased by 9.8 % (95 %CI 4.8 %–14.7 %; I2 = 57 %) and 1.5 % (95 % CI -1.5 %-4.4 %; I2 = 0%), respectively. Discussion: Overall, majority of trials included in our meta-analysis suggested that moderately hypofractionated RT is equivalent, in terms of GI and GU adverse events, to conventional fractionation. Pooled analysis showed a trend to increased GI toxicity after hypofractionated treatment, but this might be related to dose escalation rather than hypofractionation

    The assisi think tank meeting breast large database for standardized data collection in breast cancer\u2014attm.Blade

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    Background: During the 2016 Assisi Think Tank Meeting (ATTM) on breast cancer, the panel of experts proposed developing a validated system, based on rapid learning health care (RLHC) principles, to standardize inter-center data collection and promote personalized treatments for breast cancer. Material and Methods: The seven-step Breast LArge DatabasE (BLADE) project included data collection, analysis, application, and evaluation on a data-sharing platform. The multidisciplinary team developed a consensus-based ontology of validated variables with over 80% agreement. This English-language ontology constituted a breast cancer library with seven knowledge domains: baseline, primary systemic therapy, surgery, adjuvant systemic therapies, radiation therapy, followup, and toxicity. The library was uploaded to the BLADE domain. The safety of data encryption and preservation was tested according to General Data Protection Regulation (GDPR) guidelines on data from 15 clinical charts. The system was validated on 64 patients who had undergone post-mastectomy radiation therapy. In October 2018, the BLADE system was approved by the Ethical Committee of Fondazione Policlinico Gemelli IRCCS, Rome, Italy (Protocol No. 0043996/18). Results: From June 2016 to July 2019, the multidisciplinary team completed the work plan. An ontology of 218 validated variables was uploaded to the BLADE domain. The GDPR safety test confirmed encryption and data preservation (on 5000 random cases). All validation benchmarks were met. Conclusion: BLADE is a support system for follow-up and assessment of breast cancer care. To successfully develop and validate it as the first standardized data collection system, multidisciplinary collaboration was crucial in selecting its ontology and knowledge domains. BLADE is suitable for multi-center uploading of retrospective and prospective clinical data, as it ensures anonymity and data privacy

    Gustavson, Marguerite May

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    Background: Recent studies have reported improvement of outcomes (progression-free survival, overall survival, and prolongation of androgen deprivation treatment-free survival) with stereotactic body radiotherapy (SBRT) in non-small cell lung cancer and prostate cancer. The aim of this retrospective, multicenter study (MITO RT-01) was to define activity and safety of SBRT in a very large, real-world data set of patients with metastatic, persistent, and recurrent ovarian cancer (MPR-OC). Materials and Methods: The endpoints of the study were the rate of complete response (CR) to SBRT and the 24-month actuarial local control (LC) rate on \u201cper-lesion\u201d basis. The secondary endpoints were acute and late toxicities and the 24-month actuarial late toxicity-free survival. Objective response rate (ORR) included CR and partial response (PR). Clinical benefit (CB) included ORR and stable disease (SD). Toxicity was evaluated by the Radiation Therapy Oncology Group (RTOG) and the European Organization for Research and Treatment of Cancer (EORTC) and Common Terminology Criteria for Adverse Events (CTCAE) scales, according to center policy. Logistic and Cox regression were used for the uni- and multivariate analysis of factors predicting clinical CR and actuarial outcomes. Results: CR, PR, and SD were observed in 291 (65.2%), 106 (23.8%), and 33 (7.4%) lesions, giving a rate of CB of 96.4%. Patient aged 6460 years, planning target volume (PTV) 6418 cm3, lymph node disease, and biologically effective dose \u3b1/\u3b210 > 70 Gy were associated with higher chance of CR in the multivariate analysis. With a median follow-up of 22 months (range, 3\u2013120), the 24-month actuarial LC rate was 81.9%. Achievement of CR and total dose >25 Gy were associated with better LC rate in the multivariate analysis. Mild toxicity was experienced in 54 (20.7%) patients; of 63 side effects, 48 were grade 1, and 15 were grade 2. The 24-month late toxicity-free survival rate was 95.1%. Conclusions: This study confirms the activity and safety of SBRT in patients with MPR-OC and identifies clinical and treatment parameters able to predict CR and LC rate. Implications for Practice: This study aimed to define activity and safety of stereotactic body radiotherapy (SBRT) in a very large, real life data set of patients with metastatic, persistent, recurrent ovarian cancer (MPR-OC). Patient age <60 years, PTV <18 cm3, lymph node disease, and biologically effective dose \u3b1/\u3b210 >70 Gy were associated with higher chance of complete response (CR). Achievement of CR and total dose >25 Gy were associated with better local control (LC) rate. Mild toxicity was experienced in 20.7% of patients. In conclusion, this study confirms the activity and safety of SBRT in MPR-OC patients and identifies clinical and treatment parameters able to predict CR and LC rate
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