906 research outputs found

    Locating Decision Rights: Evidence from the Mutual Fund Industry

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    Mutual fund advisors make portfolio decisions for their funds on a daily basis. We examine the location of these portfolio decision rights on two dimensions. First, we consider the geographic location of the decision rights. Second, we consider whether the decision rights remain with an advisor or are allocated to an independent sub-advisor. We argue that the allocation of portfolio decision rights involves a tradeoff between the opportunity cost of not matching decision rights with specific knowledge, and the agency costs associated with moving the decision rights to the specific knowledge. The patterns in the location of decision rights are consistent with the tradeoff being a meaningful determinant of the allocation of decision rights in the mutual fund industry. We also find that funds that are predicted to be sub-advised and are sub-advised outperform those that are predicted to be sub-advised but are not

    Investor Behavior in the Mutual Fund Industry: Evidence from Gross Flows

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    Using a large sample of monthly gross flows from 1997 to 2003, we uncover several previously undocumented regularities in investor behavior. First, investor purchases and sales produce fund-level gross flows that are highly persistent. Persistence in fund flows dominates performance as a predictor of future fund flows. More importantly, failing to account for flow persistence leads to incorrect inferences with respect to the relation between performance and flows. Second, we document that investors react differently to performance depending on the type of fund, and that investor trading activity produces meaningful differences in the persistence of fund flows across mutual fund types. Third, at least some investors appear to evaluate and respond to mutual fund performance over much shorter time spans than previously assessed. Additionally, we document differences in the speed and magnitude of investors’ purchase and sales responses to performance

    Investors Do Respond to Poor Mutual Fund Performance: Evidence from Inflows and Outflows

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    Abstract We examine the relation between mutual fund performance and gross flows for a large sample of actively managed U.S. mutual funds. Unlike previous studies that have only examined periods of generally increasing net flows, our sample includes periods of both increasing and decreasing net flows. We find that outflows are related to performance, with investors withdrawing money from poor performers. We also find that outflows and inflows respond asymmetrically to performance, outflows increase more aggressively following poor performance, and inflows increase more aggressively following good performance. Additionally, we find a symmetric performance net flow relation

    Is Creutzfeldt-Jakob disease transmitted in blood?

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    Creutzfeldt-Jakob disease (CJD) has been considered infectious since the mid-1960s, but its transmissibility through the transfusion of blood or blood products is controversial. The causative agent's novel undefined nature and resistance to standard decontamination, the absence of a screening test, and the recognition that even rare cases of transmission may be unacceptable have led to the revision of policies and procedures worldwide affecting all facets of blood product manufacturing from blood collection to transfusion. We reviewed current evidence that CJD is transmitted through blood

    Frequency Dependent Rheology of Vesicular Rhyolite

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    Frequency dependent rheology of magmas may result from the presence of inclusions (bubbles, crystals) in the melt and/or from viscoelastic behavior of the melt itself. With the addition of deformable inclusions to a melt possessing viscoelastic properties one might expect changes in the relaxation spectrum of the shear stresses of the material (e.g., broadening of the relaxation spectrum) resulting from the viscously deformable geometry of the second phase. We have begun to investigate the effect of bubbles on the frequency dependent rheology of rhyolite melt. The present study deals with the rheology of bubble-free and vesicular rhyolite melts containing spherical voids of 10 and 30 vol %. We used a sinusoidal torsion deformation device. Vesicular rhyolite melts were generated by the melting (at 1 bar) of an Armenian obsidian (Dry Fountain, Erevan, Armenia) and Little Glass Mountain obsidian (California). The real and imaginary parts of shear viscosity and shear modulus have been determined in a frequency range of 0.005–10 Hz and temperature range of 600°–900°C. The relaxed shear viscosities of samples obtained at low frequencies and high temperatures compare well with data previously obtained by parallel plate viscometry. The relaxed shear viscosity of vesicular rhyolites decreases progressively with increasing bubble content. The relaxation spectrum for rhyolite melt without bubbles has an asymmetric form and fits an extended exponent relaxation. The presence of deformable bubbles results in an imaginary component of the shear modulus that becomes more symmetrical and extends into the low-frequency/high-temperature range. The internal friction Q −1 is unaffected in the high-frequency/low-temperature range by the presence of bubbles and depends on the bubble content in the high-temperature/low-frequency range. The present work, in combination with the previous study of Stein and Spera (1992), illustrates that magma viscosity can either increase or decrease with bubble content, depending upon the rate of style of strain during magmatic flow

    Cross sectional survey of human-bat interaction in Australia: public health implications

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    Background Flying foxes (megachiroptera) and insectivorous microbats (microchiroptera) are the known reservoirs for a range of recently emerged, highly pathogenic viruses. In Australia there is public health concern relating to bats\u27 role as reservoirs of Australian Bat Lyssavirus (ABLV), which has clinical features identical to classical rabies. Three deaths from ABLV have occurred in Australia. A survey was conducted to determine the frequency of bat exposures amongst adults in Australia\u27s most populous state, New South Wales; explore reasons for handling bats; examine reported practices upon encountering injured or trapped bats or experiencing bat bites or scratches; and investigate knowledge of bat handling warnings. Methods A representative sample of 821 New South Wales adults aged 16 years and older were interviewed during May and June 2011, using a computer assisted telephone interview (CATI) method. Frequencies, proportions and statistical differences in proportion were performed. Using an alpha-value of 0.05 and power of 80%, it was calculated that a sample size of 800 was required to provide statistical significance of +/- 5% for dichotomous variables. Results One-hundred-and-twenty-seven (15.5%) respondents indicated that they had previously handled a bat, being 22% (48/218) rural and 13% (78/597) urban respondents (chi2 = 9.8, p = 0.0018). Twenty one percent of males (63/304) had handled bats compared with 12% (64/517) of females (chi2 = 10.2, p = 0.0014). Overall, 42.0% (n = 345) of respondents reported having seen or heard a warning about handling bats. If faced with an injured or trapped bat, 25% (206/821) indicated that they would handle the bat, with 17% (36/206) saying that they would use their bare hands. For minor scratches, 14% (117/821) indicated that they would ignore the injury while four respondents would ignore major scratches or bites. Conclusions Previous human-bat interactions were relatively common. Bat exposures most frequently occurred with sick or injured bats, which have the highest risk of ABLV. On encountering an injured or sick bat, potentially high risk practices were commonly reported, particularly among rural males. It is important to understand why people still handle bats despite public health warnings to inform future communication strategies

    Closing the gap in Australian Aboriginal infant immunisation rates - the development and review of a pre-call strategy

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    Background: Improving timely immunisation is key to closing the inequitable gap in immunisation rates between Aboriginal children and non-Indigenous children. Aboriginal Immunisation Officers were employed in Hunter New England Local Health District (HNELHD), New South Wales (NSW), Australia, to telephone the families of all Aboriginal infants prior to the due date for their first scheduled vaccination. Methods: Aboriginal Immunisation Officers contacted the families of Aboriginal children born in the Hunter New England Local Health District (HNELHD) by telephone before their due immunisation date (pre-call) to provide the rationale for timely immunisation, and to facilitate contact with culturally safe local immunisation services if this was required. The impact of this strategy on immunisation coverage rates is reviewed. Results: For the period March 2010 to September 2014 there was a significant increase in immunisation coverage rate for Aboriginal children at 12 months of age in HNELHD (p < 0.0001). The coverage in the rest of NSW Aboriginal children also increased but not significantly (p = 0.218). Over the full study period there was a significant decrease in the immunisation coverage gap between Aboriginal children and non-Indigenous children in HNELHD (p < 0.0001) and the rest of NSW (p = 0.004). The immunisation coverage gap between Aboriginal and non-Indigenous infants decreased at a significantly faster rate in HNELHD than the rest of NSW (p = 0.0001). By the end of the study period in 2014, immunisation coverage in HNELHD Aboriginal infants had surpassed that of non-Indigenous infants by 0.8 %. Conclusions: The employment of Aboriginal immunisation officers may be associated with closing of the gap between Aboriginal and non-Indigenous infants' immunisation coverage in HNELHD and NSW. The pre-call telephone strategy provided accelerated benefit in closing this gap in HNELHD

    The significance of plagioclase textures in mid-ocean ridge basalt (Gakkel Ridge, Arctic Ocean)

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    Textures and compositions of minerals can be used to infer the physiochemical conditions present within magmatic systems. Given that plagioclase is an abundant phase in many magmatic systems, understanding the link between texture and process is vital. Here, we present a database of textural and compositional data for > 1800 plagioclase crystals in mid-ocean ridge basalt from the Gakkel Ridge (Arctic Ocean) to investigate the physiochemical conditions and processes that govern the formation of plagioclase textures and compositions. The Gakkel basalts have high modal crystal contents (up to 50%). The crystal cargo is complex, with both individual plagioclase and glomerocrysts showing large variations in crystal habit, zoning and resorption. The most common types of zoning are reverse and patchy; we attribute patchy zoning to infilling following either skeletal growth or resorption. Resorption is abundant, with multiple resorption events commonly present in a single crystal, and results from both magmatic recharge and decompression. Periods of strong undercooling, distinct to quench crystallisation, are indicated by matured skeletal crystals and thin normally zoned melt inclusion-rich bands following resorption. Individual samples often contain diverse textural and compositional plagioclase groups. Furthermore, most plagioclase is not in equilibrium with its host melt. Finally, the porous open structures of some glomerocrysts suggest that they represent pieces of entrained disaggregated mush. We interpret this to indicate that the crystal cargo is not generally phenocrystic in origin. Instead, plagioclase crystals that formed in different parts of a mush-dominated plumbing system were entrained into ascending melts. The textures of individual crystals are a function of their respective histories of (under)cooling, magma mixing and decompression. The morphologies of melt inclusion trapped in the plagioclase crystals are associated with specific host crystal textures, suggesting a link between plagioclase crystallisation processes and melt inclusion entrapment. The database of plagioclase presented herein may serve as a template for the interpretation of plagioclase textures in magmatic systems elsewhere

    Pre-clinical medical student reflections on implicit bias: Implications for learning and teaching

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    CONTEXT: Implicit bias affects health professionals\u27 clinical decision-making; nevertheless, published reports of medical education curricula exploring this concept have been limited. This research documents a recent approach to teaching implicit bias. METHODS: Medical students matriculating during 2014 and 2015 participated in a determinants of health course including instruction about implicit bias. Each submitted a reflective essay discussing implicit bias, the experience of taking the Implicit Association Test (IAT), and other course content. Using grounded theory methodology, student essays that discussed reactions to the IAT were analyzed for content themes based on specific statements mapping to each theme. Twenty-five percent of essays underwent a second review to calculate agreement between raters regarding identification of statements mapping to themes. OUTCOME: Of 250 essays, three-quarters discussed students\u27 results on the IAT. Theme comments related to: a) experience taking the IAT, b) bias in medicine, and c) prescriptive comments. Most of the comments (84%) related to students\u27 acknowledging the importance of recognizing implicit bias. More than one-half (60%) noted that bias affects clinical decision-making, and one-fifth (19%) stated that they believe it is the physician\u27s responsibility to advocate for dismantling bias. CONCLUSIONS: Through taking the IAT and developing an understanding of implicit bias, medical students can gain insight into the effect it may have on clinical decision-making. Having pre-clinical medical students explore implicit bias through the IAT can lay a foundation for discussing this very human tendency

    Reasons for and consequences of missed appointments in general practice in the UK: questionnaire survey and prospective review of medical records

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    Background Missed appointments are a common occurrence in primary care in the UK, yet little is known about the reasons for them, or the consequences of missing an appointment. This paper aims to determine the reasons for missed appointments and whether patients who miss an appointment subsequently consult their general practitioner (GP). Secondary aims are to compare psychological morbidity, and the previous appointments with GPs between subjects and a comparison group. Methods Postal questionnaire survey and prospective medical notes review of adult patients missing an appointment and the comparison group who attended appointments over a three week period in seven general practices in West Yorkshire. Results Of the 386 who missed appointments 122 (32%) responded. Of the 386 in the comparison group 223 (58%) responded, resulting in 23 case-control matched pairs with complete data collection. Over 40% of individuals who missed an appointment and participated said that they forgot the appointment and a quarter said that they tried very hard to cancel the appointment or that it was at an inconvenient time. A fifth reported family commitments or being too ill to attend. Over 90% of the patients who missed an appointment subsequently consulted within three months and of these nearly 60% consulted for the stated problem that was going to be presented in the missed consultation. The odds of missing an appointment decreased with increasing age and were greater among those who had missed at least one appointment in the previous 12 months. However, estimates for comparisons between those who missed appointments and the comparison group were imprecise due to the low response rate. Conclusion Patients who miss appointments tend to cite practice factors and their own forgetfulness as the main reasons for doing so, and most attend within three months of a missed appointment. This study highlights a number of implications for future research. More work needs to be done to engage people who miss appointments into research in a meaningful way
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