The Debate on Influencing Doctors’ Decisions: Are Drug Characteristics the Missing Link?

Decision-making by physicians on patients’ treatment has come under increased public scrutiny. In fact, there is a fair amount of debate on the effects of marketing actions of pharmaceutical firms toward physicians and their impact on physician prescription behavior. While some scholars find a strong and positive influence of marketing actions, some find only moderate effects, and others even find negative effects. Debate is also mounting on the role of other influencers (such as patient requests) in physician decision-making, both on prescriptions and sample-dispensing. The authors argue that one factor that may tip the balance in this debate is the role of drug characteristics, such as a drug’s effectiveness and a drug’s side effects. Using a unique data set, they show that marketing efforts – operationalized as detailing and symposium meetings of firms to physicians – and patient requests do affect physician decision-making differentially across brands. Moreover they find that the responsiveness of physicians’ decision-making to marketing efforts and patient requests depends upon the drug’s effectiveness and side effects. The paper presents clear guidelines for public policy and managerial practice and envisions that the study of the role of drug characteristics – such as effectiveness and side effects – may lead to valuable insights in this surging public debate.public policy;side effects;sampling;Physician decision-making;drug effectiveness;drug prescription;marketing efforts;patient requests;pharmaceuticals;sample-dispensing

An empirical study of the transition from paid work to self-employment

We explore the relationship between the probability of a transition from paid work to self-employment and three explanatory variables: paid income, predicted income, and income for ability. We use panel data for heads of households from the PSID SRC sample for eight pairs of years. Our results show that therelationship between paid income and self-employment is not linear. We then break up paid income into two components: a)predicted income based on human capital, demographic, and locational variables, and b) income for ability. Again, we find nolinear relationship between self-employment and either predicted income or income for ability. We then test for curvilinear relationships between these three variables (i.e., paid income, predicted income, and income for ability) and the transition to self-employment. We find that individuals with low incomes are more likely to take up self-employment. Further, income for ability is a stronger predictor of the transition to self-employment than predicted income. We show that the relationship between ability and self-employment is U shaped: very low ability and very high ability individuals are more likely to take up self-employment than medium ability individuals. We use prospect theory to explain this result.Entrepreneurship; self-employment; opportunity costs; value creation;

Expert systems for security trend analysis of transient-voltage-limited power systems

In this dissertation, we apply expert system techniques and Transient Energy Function (TEF) method results for dynamic system security assessment (DSSA). The concept of power system vulnerability combines the effect of contingencies on the security level and its rate of change with the changing system conditions and/or parameters. Vulnerability of a power system can be computed using the results of the sensitivity analysis program of the TEF method. The computation of vulnerability requires a large amount of data obtained from the results of stability analysis programs and this data needs to be organized into a structured knowledge base for DSSA. Further, the power system operators combine the above stability results with their experience and understanding of the power system in deciding the necessary corrective actions. This decision making process, which is based on heuristic rules, can be better solved using expert system techniques than algorithmic techniques;This dissertation describes an implementation of an expert system for DSSA which uses data from the Northern States Power Company (NSP) in Minnesota under certain operating conditions. The NSP system is transient-voltage-limited, and the security index used by NSP is the Twin City Export Margin (TCEM). The TCEM is the difference in MW between the actual export of power from Twin Cities and its allowable limit computed from stability results. This security index is correlated to the normalized energy margin [delta] V of the TEF method. The expert system finds the NSP loading trend and uses this trend to predict the trend of the security index, TCEM. The expert system also adjusts the trend of the controlling parameters so that the security index can be kept at a predefined safe and economic level. The expert system primarily uses a supervised learning scheme and has an interactive user interface with graphic output. The TEF method is used for calculating stability information and the sensitivities of the control parameters on the security index. The knowledge base of the expert system is updated using the results of the TEF method

An Empirical Study of the Transition from Paid Work to Self-Employment

We explore the transition from paid work to self-employment using three explanatory variables: paid income, predicted income, and income for ability. We find no linear relationship between the three variables and the self-employment transition. We then test for curvilinear relationships. We find that individuals with low incomes are more likely to take up self-employment. Further, income for ability is the strongest predictor of the transition to self-employment. The relationship between ability and self-employment is U-shaped: very low ability and very high ability individuals are more likely to take up self-employment

Doxorubicin resistant choriocarcinoma cell line derived spheroidal cells exhibit stem cell markers but reduced invasion

Cell cycle-specifc cancer chemotherapy is based on the ability of a drug to halt, minimise or destroy rapidly dividing cells. However, their efcacy is limited by the emergence of a self-renewing cell pool called “cancer stem cells” (CSC). Choriocarcinoma is a tumour of trophoblastic tissue. We, in this study, analysed whether spheroids generated from doxorubicintreated and non-treated choriocarcinoma cell lines exhibit markers of stem cells. Two choriocarcinoma cell lines, namely JEG-3 and BeWo, were used in this study. Spheroids were generated from doxorubicin-treated cells and the non-treated cells under non-adherent condition, followed by analysis of stem-cell markers’ expression, namely NANOG, OCT4 and SOX2. Immunofuorescence analysis suggested a general increase in the markers’ concentration in spheroids relative to the parental cells. RT-qPCR and immunoblots showed an increase in the stem-cell marker expression in spheroids generated from doxorubicin-treated when compared to non-treated cells. In spheroids, Sox2 was signifcantly upregulated in doxorubicintreated spheroids, whereas Nanog and Oct4 were generally downregulated when compared to non-treated spheroids. Both 2D and 3D invasion assays showed that the spheroids treated with doxorubicin exhibited reduced invasion. Our data suggest that choriocarcinoma cell lines may have the potential to produce spheroidal cells, yet the drug-treatment afected the invasion potential of spheroids

Elliptic Curves with Complex Multiplication and a Character Sum

AbstractLetf(x)∈Q[X] be a cubic such thaty2=f(x) is an elliptic curve with complex multiplication by[formula],[formula],[formula]or[formula]. We want to calculate the character sum[formula]where (·/p) is the Legendre symbol. We show that it is enough to calculate the sum for a finite number of primes and this has been done