734 research outputs found

    Atomic Cournotian Traders May Be Walrasian

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    In a bilateral oligopoly, with large traders, represented as atoms, and small traders, represented by an atomless part, when is there a nonempty intersection between the sets of Walras and Cournot–Nash allocations? Using a two-commodity version of the Shapley window model, we show that a necessary and sufficient condition for a Cournot–Nash allocation to be a Walras allocation is that all atoms demand a null amount of one of the two commodities. We provide four examples which show that this characterization holds non-vacuously. When our condition fails to hold, we also confirm, through some examples, the result obtained by Okuno et al. (1980): small traders always have a negligible influence on prices, while the large traders keep their strategic power even when their behavior turns out to be Walrasian in the cooperative framework considered by Gabszewicz and Mertens (1971) and Shitovitz (1973)

    Kalai and Muller's Possibility Theorem: A Simplified Integer Programming Version

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    We provide a respecification of an integer programming characterization of Arrovian social welfare functions introduced by Sethuraman et al. (Math Oper Res 28:309–326, 2003). By exploiting this respecification, we give a new and simpler proof of Theorem 2 in Kalai and Muller (J Econ Theory 16:457–469, 1977)

    How many manuscripts should I peer review per year?

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    Peer review provides the foundation for the scholarly publishing system. The conventional peer review system consists of using authors of articles as reviewers for other colleagues' manuscripts in a collaborative-basis system. However, authors complain about a theoretical overwhelming number of invitations to peer review. It seems that authors feel that they are invited to review many more manuscripts than they should when taking into account their participation in the scholarly publishing system. The high number of scientific journals and the existence of predatory journals were reported as potential causes of this excessive number of reviews required. In this editorial, we demonstrate that the number of reviewers required to publish a given number of articles depends exclusively on the journals' rejection rate and the number of reviewers intended per manuscript. Several initiatives to overcome the peer review crises are suggested

    Limitations and perceived delays for diagnosis and staging of lung cancer in Portugal: A nationwide survey analysis

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    Background We aimed to identify the perception of physicians on the limitations and delays for diagnosing, staging and treatment of lung cancer in Portugal. Methods Portuguese physicians were invited to participate an electronic survey (Feb-Apr-2020). Descriptive statistical analyses were performed, with categorical variables reported as absolute and relative frequencies, and continuous variables with non-normal distribution as median and interquartile range (IQR). The association between categorical variables was assessed through Pearson’s chi-square test. Mann-Whitney test was used to compare categorical and continuous variables (Stata v.15.0). Results Sixty-one physicians participated in the study (45 pulmonologists, 16 oncologists), with n = 26 exclusively assisting lung cancer patients. Most experts work in public hospitals (90.16%) in Lisbon (36.07%). During the last semester of 2019, responders performed a median of 85 (IQR 55–140) diagnoses of lung cancer. Factors preventing faster referral to the specialty included poor articulation between services (60.0%) and patients low economic/cultural level (44.26%). Obtaining National Drugs Authority authorization was one of the main reasons (75.41%) for delaying the begin of treatment. The cumulative lag-time from patients’ admission until treatment ranged from 42–61 days. Experts believe that the time to diagnosis could be optimized in around 11.05 days [IQR 9.61–12.50]. Most physicians (88.52%) started treatment before biomarkers results motivated by performance status deterioration (65.57%) or high tumor burden (52.46%). Clinicians exclusively assisting lung cancer cases reported fewer delays for obtaining authorization for biomarkers analysis (p = 0.023). Higher waiting times for surgery (p = 0.001), radiotherapy (p = 0.004), immunotherapy (p = 0.003) were reported by professionals from public hospitals. Conclusions Physicians believe that is possible to reduce delays in all stages of lung cancer diagnosis with further efforts from multidisciplinary teams and hospital administration.This work was supported by AstraZeneca. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

    Limitations and perceived delays for diagnosis and staging of lung cancer in Portugal: A nationwide survey analysis

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    Background: We aimed to identify the perception of physicians on the limitations and delays for diagnosing, staging and treatment of lung cancer in Portugal. Methods: Portuguese physicians were invited to participate an electronic survey (Feb-Apr-2020). Descriptive statistical analyses were performed, with categorical variables reported as absolute and relative frequencies, and continuous variables with non-normal distribution as median and interquartile range (IQR). The association between categorical variables was assessed through Pearson's chi-square test. Mann-Whitney test was used to compare categorical and continuous variables (Stata v.15.0). Results: Sixty-one physicians participated in the study (45 pulmonologists, 16 oncologists), with n = 26 exclusively assisting lung cancer patients. Most experts work in public hospitals (90.16%) in Lisbon (36.07%). During the last semester of 2019, responders performed a median of 85 (IQR 55-140) diagnoses of lung cancer. Factors preventing faster referral to the specialty included poor articulation between services (60.0%) and patients low economic/cultural level (44.26%). Obtaining National Drugs Authority authorization was one of the main reasons (75.41%) for delaying the begin of treatment. The cumulative lag-time from patients' admission until treatment ranged from 42-61 days. Experts believe that the time to diagnosis could be optimized in around 11.05 days [IQR 9.61-12.50]. Most physicians (88.52%) started treatment before biomarkers results motivated by performance status deterioration (65.57%) or high tumor burden (52.46%). Clinicians exclusively assisting lung cancer cases reported fewer delays for obtaining authorization for biomarkers analysis (p = 0.023). Higher waiting times for surgery (p = 0.001), radiotherapy (p = 0.004), immunotherapy (p = 0.003) were reported by professionals from public hospitals. Conclusions: Physicians believe that is possible to reduce delays in all stages of lung cancer diagnosis with further efforts from multidisciplinary teams and hospital administration.his work was supported by AstraZeneca. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscripinfo:eu-repo/semantics/publishedVersio

    Use of electrical bioimpedance analysis to evaluate the quality of bovine raw milk

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    The objective of the present study was to use electrical bioimpedance analysis (BIA) as an alternative method of evaluating the quality of bovine raw milk. Fourteen lactating purebred Dutch cows were used. For the analyses of milk quality and electrical bioimpedance, 140 ml milk per mammary quarter and a homogeneous sample of each animal were collected, totalling 70 samples. The criteria used to evaluate milk quality consisted of somatic cell count (CCS), total bacterial count (CBT), fat, protein, lactose, total solids (ST) and non-greasy solids (SNG) as required by IN No 62/2011. A monofrequential 50 kHz and 800 μA alternating current generator was used for electrical BIAs. The temperature of the raw milk was 5 °C for all samples. Primary resistance and reactance readings were obtained. From these values, the values of impedance, conductance and phase angle were obtained. Correlation analyses were performed to determine the variables used by the regression analyses. The regression analysis was performed using raw milk components as dependent variables and BIA measurements as independent variables. Lactose, ST and SNG were the components of milk that correlated best and presented moderate prediction equations in relation to BIA variables. The prediction equations using resistance showed R2 of 0.42 and 0.45 for ST and SNG, respectively. In the prediction equation for ST and SNG, the conductance resulted in R2 of 0.45, and 0.45, respectively. Regarding impedance, the R2 of 0.42 and 0.45 were obtained for the predicted equations ST and SNG, respectively. Thus, it can be concluded that BIA has the potential to estimate the composition and quality of bovine raw milk.Keywords: conductance, impedance, milk compositio

    Safety of biologics approved for the treatment of rheumatoid arthritis and other autoimmune diseases: a disproportionality analysis from the FDA Adverse Event Reporting System (FAERS)

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    Introduction: The molecular and pharmacological complexity of biologic disease-modifying antirheumatic drugs used for the management of rheumatoid arthritis (RA) favors the occurrence of adverse drug reactions (ADRs), which should be constantly monitored in post-marketing safety studies. Objective: The aim of this study was to identify signals of disproportionate reporting (SDR) of clinical relevance related to the use of biologic drugs approved for RA and other autoimmune diseases. Methods: All suspected ADRs registered in the FDA Adverse Event Reporting System between January 2003 and June 2016 were collected. The reporting odds ratio was used as a measure of disproportionality to identify possible SDRs related to biologics. Those involving important medical events and designated medical events (DME) were prioritized. Results: In total, 2602 SDRs were prioritized. The most commonly reported were ‘Infections and infestations’ (32.2%) and ‘Neoplasms benign, malignant, and unspecified’ (20.4%), and were mainly related to use of infliximab (25.3%, p < 0.001, and 28.8%, p = 0.002, respectively). Sixty-three signals involving DMEs were identified, most of which were related to rituximab (n = 27), and were mainly due to ‘blood disorders’. Amongst the DMEs detected for more than one biologic, ‘intestinal perforation’ and ‘pulmonary fibrosis’ were related to most of them. Conclusions: The results of this study highlight possible safety issues associated with biologics, whose relationship should be more thoroughly investigated. Our results contribute to future research on the identification of clinically relevant risks associated with these drugs, and may help contribute to their rational and safe use

    UNDERSTANDING RISK DISSEMINATION: AN OVERVIEW IN SOYBEAN AND CORN MARKETS

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    This paper provides an overview of the research literature on risk transmission for the corn and soybean markets. The systematic review includes research, structure and synthesis of empirical studies using terms such as contagion, transmission and spillover to assess the spread of risk across markets. The featured topics include the review of the main analytical perspectives of agricultural market interaction with other markets and theoretical developments in price risk analyses. Exogenous changes to the agricultural market, such as the financial crisis, rise of biofuels and financialization of commodities, are pointed out in the literature as vectors of risk transmission to the corn and soybean markets. The results show the increase of studies that evaluate spillover, with the predominant use of the multivariate GARCH approach, focused mainly on interrelations between the food and energy markets
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