220 research outputs found

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    Contains fulltext : 4215.pdf (publisher's version ) (Open Access

    Ambiguity Attitudes about Investments: Evidence from the Field

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    Using an incentivized survey and a representative sample of investors, we elicit ambiguity attitudes toward a familiar company stock, a local stock index, a foreign stock index, and a crypto currency. We separately estimate ambiguity aversion (ambiguity preferences) and perceived ambiguity levels (perceptions about ambiguity), while controlling for unknown likelihood beliefs. We show that ambiguity aversion is highly correlated across different assets and can be summarized by a single underlying factor. By contrast, individuals’ perceived ambiguity levels differ depending on the type of asset and cannot be summarized by a single underlying factor. Perceived ambiguity is mitigated by financial literacy and education, while the preference component is correlated with risk aversion. Perceived ambiguity proves to be related to actual investment choices, validating our measure. Finally, our results imply that policies enhancing financial literacy and knowledge of financial markets can help stimulate equity market participation and reduce inequality, as these reduce peoples’ perceived levels of ambiguity about financial assets

    Household Portfolio Underdiversification and Probability Weighting: Evidence from the Field

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    We test whether probability weighting affects household portfolio choice in a representative survey. On average, people display inverse-S shaped probability weighting, overweighting low probability events. As theory predicts, probability weighting is positively associated with portfolio underdiversification and significant Sharpe ratio losses. Analyzing respondents’ individual stock holdings, we find higher probability weighting is associated with owning lottery-type stocks and positively-skewed equity portfolios. People with higher probability weighting are less likely to own mutual funds and more likely to either avoid equities or hold individual stocks. We are the first to empirically link individuals’ elicited probability weighting and real-world decisions under risk

    Impact of ultraviolet radiation on marine crustacean zooplankton and ichthyoplankton: a synthesis of results from the estuary and Gulf of St. Lawrence, Canada

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    The objectives of the research program reported upon here were (1) to measure ambient levels of UV radiation and determine whichvariables most strongly affected its attenuation in the waters of the estuary and Gulf of St. Lawrence, Canada; and (2) to investigate the potential direct impacts of W radiation on species of crustacean zooplankton and fish whose early life stages are planktonic. In this geographic region, productivity-determining biophysical interactions occur in the upper 0 to 30 m of the water column. Measurements of the diffuse attenuation coefficients for ultraviolet-B radiation (W-B, 280 to 320 nm) at various locations in this region indicated maximum 10% depths (the depth to which 10% of the surface energy penetrates at a given wavelength) of 3 to 4 m at a wavelength of 310 nm. Organisms residing in this layer-including the eggs and larvae of Calanus finmarchicus and Atlantic cod Gadus morhua-are exposed to biologically damaging levels of W radiation. As a result of these physical and biological characteristics, this system offered a relevant opportunity to assess the impacts of UV on subarctic marine ecosystems. Eggs of C. finmarchicus were incubated under the sun, with and without the W-B and/or UV-A (320 to 400 nm) wavebands. W-exposed eggs exhibited low percent hatchmg compared to those protected from W : W radiation had a strong negative impact on C. finmarchicus eggs. Further, percent hatching in W-B-exposed eggs was not significantly lower than that in eggs exposed to UV-A only: under natural sunlight, UV-A radiation appeared to be more detrimental to C. finmarchicus embryos than was UV-B. In analogous experiments with Atlantic cod eggs, exposure to UV-B produced a significant negative effect. However, UV-A had no negative effect on cod eggs. Additional experiments using a solar simulator (SS) revealed high wavelength-dependent mortality in both C. finmarchicus and cod embryos exposed to UV. The strongest effects occurred under exposures to wavelengths below 312 nm. At the shorter wavelengths (<305 nm) UV-B-induced mortality was strongly dose-dependent, but (for both C. finmarchicus and cod) not significantly influenced by dose-rate. Thus, at least within the limits of the exposures under which the biological weighting functions (BWFs) were generated, reciprocity held. The BWFs derived for UV-B-induced mortality in C. finmarchicus and cod eggs were similar in shape to the action spectrum for UV-B effects on naked DNA. Further, the wavelengthdependence of DNA damage was similar to that for the mortality effect. These observations suggest that W-induced mortality in C. finmarchicus and cod eggs is a direct result of DNA damage. There was no evidence of a detrimental effect of UV-A radiation in these SS-derived results. A mathematical model that includes the BWFs, vertical mixing of eggs, meteorological and hydrographic conditions, and ozone depletion, indicates that W-induced mortality in the C. finmarchicus egg population could be as high as 32.5 %, while the impact on the cod egg population was no more than 1.2%. Variability in cloud cover, water transparency (and the variables that affect it), and vertical distribution and displacement of planktonic organisms within the mixed layer can all have a greater effect on the flux of UV-B radiation to which they are exposed than will ozone layer depletion at these latitudes. Our observations indicate that C, finmarchicus and cod eggs present in the first meter of the water column (likely only a small percentage of the total egg populations) are susceptible to W radiation. However, although exposure to UV can negatively impact crustacean zooplankton and ichthyoplankton populations, these direct effects are likely minimal within the context of all the other environmental factors that produce the very high levels of mortality typically observed in their planktonic early life stages. The impact of indnect effects-which may well be of much greater import-has yet to be evaluated

    Long-Term Health-Related Quality of Life after Four Common Surgical Treatment Options for Breast Cancer and the Effect of Complications: A Retrospective Patient-Reported Survey among 1871 Patients

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    Background: Differences in quality-of-life outcomes after different surgical breast cancer treatment options, including breast reconstruction, are relevant for counseling individual patients in clinical decision-making, and for (societal) evaluations such as cost-effectiveness analyses. However, current literature shows contradictory results, because of use of different patient-reported outcome measures and study designs with limited patient numbers. The authors set out to improve this evidence using patient-reported outcome measures in a large, cross-sectional study for different surgical breast cancer treatment options. Methods: Quality of life was assessed through the EQ-5D-5L, European Organization for Research and Treatment of Cancer Quality of Life Questionnaires C30 and BR23, and the BREAST-Q. Patients with different treatments were compared after propensity-weighted adjustment of pretreatment differences. The EQ-5D was used to value the effect of surgical complications. Results: A total of 1871 breast cancer patients participated (breast-conserving surgery, n = 615; mastectomy, n = 507; autologous reconstruction, n = 330; and implant-based reconstruction, n = 419). Mastectomy patients reported the lowest EQ-5D score (mastectomy, 0.805, breast-conserving surgery, 0.844; autologous reconstruction, 0.849; and implant-based reconstruction, 0.850) and functioning scores of the C30 questionnaire. On the BREAST-Q, autologous reconstruction patients had higher mean Satisfaction with Outcome, Satisfaction with Breasts, and Sexual Well-being scores than implant-based reconstruction patients. Complications in autologous reconstruction patients resulted in a substantially lower quality of life than in implant-based reconstruction patients. Conclusions: This study shows the added value of breast conservation and reconstruction compared with mastectomy; however, differences among breastconserving surgery, implant-based reconstruction, and autologous breast reconstruction were subtle. Complications resulted in poorer health-related quality of life. (Plast. Reconstr. Surg. 146: 1, 2020.

    Nijmegen paediatric CDG rating scale: a novel tool to assess disease progression

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    Congenital disorders of glycosylation (CDG) are a group of clinically heterogeneous inborn errors of metabolism. At present, treatment is available for only one CDG, but potential treatments for the other CDG are on the horizon. It will be vitally important in clinical trials of such agents to have a clear understanding of both the natural history of CDG and the corresponding burden of disability suffered by patients. To date, no multicentre studies have attempted to document the natural history of CDG. This is in part due to the lack of a reliable assessment tool to score CDG’s diverse clinical spectrum. Based on our earlier experience evaluating disease progression in disorders of oxidative phosphorylation, we developed a practical and semi-quantitative rating scale for children with CDG. The Nijmegen Paediatric CDG Rating Scale (NPCRS) has been validated in 12 children, offering a tool to objectively monitor disease progression. We undertook a successful trial of the NPCRS with a collaboration of nine experienced physicians, using video records of physical and neurological examination of patients. The use of NPCRS can facilitate both longitudinal and natural history studies that will be essential for future interventions

    Wild chacma baboons (Papio ursinus) remember single foraging episodes

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    This study was supported by grants from Zürcher Hochschulverein, Schweizerische Akademie für Naturwissenschaften, Stiftung Thyll-Dürr, and Stiftung Annemarie Schindler, to R.N.Understanding animal episodic-like memory is important for tracing the evolution of the human mind. However, our knowledge about the existence and nature of episodic-like memory in non-human primates is minimal. We observed the behaviour of a wild male chacma baboon faced with a trade-off between protecting his stationary group from aggressive extra-group males and foraging among five out-of-sight platforms. These contained high-priority food at a time of natural food shortage. In 10 morning and eight evening trials, the male spontaneously visited the platforms in five and four different sequences, respectively. In addition, he interrupted foraging sequences at virtually any point on eight occasions, returning to the group for up to 2 h. He then visited some or all of the remaining platforms and prevented revisits to already depleted ones, apparently based on his memory for the previous foraging episode about food value, location, and time. Efficient use of memory allowed him to keep minimal time absent from his group while keeping food intake high. These findings support the idea that episodic-like memory offers an all-purpose solution to a wide variety of problems that require flexible, quick, yet precise decisions in situations arising from competition for food and mates in wild primates.PostprintPeer reviewe
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