Framing as Path-Dependence

A “framing” effect occurs when an agent’s choices are not invariant under changes in the way a choice problem is formulated, e.g. changes in the way the options are described (violation of description invariance) or in the way preferences are elicited (violation of procedure invariance). In this paper we examine precisely which classical conditions of rationality it is whose non-satisfaction may lead to framing effects. We show that (under certain conditions), if (and only if) an agent's initial dispositions on a set of propositions are “implicitly inconsistent”, her decisions may be “path-dependent”, i.e. dependent on the order in which the propositions are considered. We suggest that different ways of framing a choice problem may induce the order in which relevant propositions are considered and hence affect the decision made. This theoretical explanation suggests some observations about human psychology which are consistent with those made by psychologists and provides a unified framework for explaining violations of description and procedure invariance.framing, preference reversal, path-dependence, rationality, deductive closure

Using Google Analytics to evaluate an email information literacy program for medical and dental students

Également publié dans : Journal of the Medical Library Association, 2013, vol. 101, no 1, E1-E19Objectives: An email information literacy program has been effective for over a decade at Université de Montréal’s Health Library. Students periodically receive messages highlighting the content of guides on the library’s website. We wish to evaluate, using Google Analytics, the effects of the program on specific webpage statistics. Using the data collected, we may pinpoint popular guides as well as others that need improvement. Methods: In the program, first and second-year medical (MD) or dental (DMD) students receive eight bi-monthly email messages. The DMD mailing list also includes graduate students and professors. Enrollment to the program is optional for MDs, but mandatory for DMDs. Google Analytics (GA) profiles have been configured for the libraries websites to collect visitor statistics since June 2009. The GA Links Builder was used to design unique links specifically associated with the originating emails. This approach allowed us to gather information on guide usage, such as the visitor’s program of study, duration of page viewing, number of pages viewed per visit, as well as browsing data. We also followed the evolution of clicks on GA unique links over time, as we believed that users may keep the library's emails and refer to them to access specific information. Results: The proportion of students who actually clicked the email links was, on average, less than 5%. MD and DMD students behaved differently regarding guide views, number of pages visited and length of time on the site. The CINAHL guide was the most visited for DMD students whereas MD students consulted the Pharmaceutical information guide most often. We noted that some students visited referred guides several weeks after receiving messages, thus keeping them for future reference; browsing to additional pages on the library website was also frequent. Conclusion: The mitigated success of the program prompted us to directly survey students on the format, frequency and usefulness of messages. The information gathered from GA links as well as from the survey will allow us to redesign our web content and modify our email information literacy program so that messages are more attractive, timely and useful for students

Pension and Intergenerational Balance - a case study of Norway, Poland and Germany using Generational Accounting

In this paper we apply the method of Generational Accounting to analyse whether today’s government policy burdens future generations with a heavier load than current generations. We analyse pay-as-you-go pension systems and their reforms in Norway, Poland and Germany. Our results show that, through these reforms, pension systems in all three countries became more intergenerationally balanced as the implicit debt to be paid by future generations was reduced. However, the burden is shared differently: in Norway current pensioners have to contribute to enhancing the financial sustainability of the pension system while Poland and Germany seem to protect current pensioners at the expense of younger generations

Carbon allocation and competition maintain variation in plant root mutualisms

Plants engage in multiple root symbioses that offer varying degrees of benefit. We asked how variation in partner quality persists using a resource-ratio model of population growth. We considered the plant’s ability to preferentially allocate carbon to mutualists and competition for plant carbon between mutualist and nonmutualist symbionts. We treated carbon as two nutritionally interchangeable, but temporally separated, resources—carbon allocated indiscriminately for the construction of the symbiosis, and carbon preferentially allocated to the mutualist after symbiosis establishment and assessment. This approach demonstrated that coexistence of mutualists and nonmutualists is possible when fidelity of the plant to the mutualist and the cost of mutualism mediate resource competition. Furthermore, it allowed us to trace symbiont population dynamics given varying degrees of carbon allocation. Specifically, coexistence occurs at intermediate levels of preferential allocation. Our findings are consistent with previous empirical studies as well the application of biological market theory to plantroot symbioses.This work was supported by DEB-1556664 (J.D.B). N.C. was supported by a National Science Foundation Graduate Research Fellowshi

Fungal Endophytes Interact with Endophytic Yeast Isolated from Soybean Leaves

Endophytes (endo = inside and phyte=plant) are microscopic fungi that live inside of the leaves of all species of plants and can have beneficial effects on their hosts. Previous work in our lab has shown a significant decrease of Sporobolomyces sp., an endophytic yeast, within soybean hosts exposed to elevated levels of CO₂. Sporobolomyces sp. has certain properties to enable them to act as natural biocontrol agents. This pink yeast may have untapped potential to protect crops from pathogenic organisms. If Sporobolomyces sp. interacts with fungal pathogens, it may have strong effects on other fungal endophytes in the community. The aim of this experiment was to examine how Sporobolomyces sp. interacts with endophytes isolated from soy leaves both in terms of fungal growth and phenotypic changes

The Drivers of Entrepreneurial Intentions - An Empirical Study among Information Systems and Computer Science Students

The last decade has seen an enormous increase in research on entrepreneurship education. However, there is so far only little research on entrepreneurship education in the field of information technology. To address this research gap, we conducted an empirical study based on an extended model of the Theory of Planned Behavior among Information Systems and Computer Science students. We found Attitude being the main driver for Information Systems students, and having discovered a Business Idea being the most influential factor for Computer Science students. In a more detailed analysis, the perception that being an entrepreneur does not come with a high risk to fail, the opportunity for self-fulfillment, and the chance of a high monetary reward could be identified as the crucial drivers regarding Information Systems students. Based on our findings, we discuss the implications for developing more entrepreneurially-oriented courses tailored to both groups of students

Implications for the Formation of Blue Straggler Stars from HST Ultraviolet Observations of NGC 188

We present results of a Hubble Space Telescope far-ultraviolet (FUV) survey searching for white dwarf (WD) companions to blue straggler stars (BSSs) in open cluster NGC 188. The majority of NGC 188 BSSs (15 of 21) are single-lined binaries with properties suggestive of mass-transfer formation via Roche lobe overflow, specifically through an asymptotic giant branch star transferring mass to a main sequence secondary, yielding a BSS binary with a WD companion. In NGC 188, a BSS formed by this mechanism within the past 400 Myr will have a WD companion hot and luminous enough to be directly detected as a FUV photometric excess with HST. Comparing expected BSS FUV emission to observed photometry reveals four BSSs with WD companions above 12,000 K (younger than 250 Myr) and three WD companions with temperatures between 11,000-12,000 K. These BSS+WD binaries all formed through recent mass transfer. The location of the young BSSs in an optical color-magnitude diagram (CMD) indicates that distance from the zero-age main sequence does not necessarily correlate with BSS age. There is no clear CMD separation between mass transfer-formed BSSs and those likely formed through other mechanisms, such as collisions. The seven detected WD companions place a lower limit on the mass-transfer formation frequency of 33%. We consider other possible formation mechanisms by comparing properties of the BSS population to theoretical predictions. We conclude that 14 BSS binaries likely formed from mass transfer, resulting in an inferred mass-transfer formation frequency of approximately 67%.Comment: 13 pages, 6 figures, accepted to the Astrophysical Journa

How Does Climate Change Affect Endophytic Fungi?

Plant-associated microorganisms can have major effects on plant health, but climate change can affect plant microbiomes. While it is unknown how climate change will affect aboveground plant-associated microorganisms, such as foliar endophytic fungi, we hypothesize that increased CO2 concentrations will increase species richness and diversity in endophytic fungal communities, because increased plant photosynthesis under elevated CO2 will increase the resources available to the fungi