441 research outputs found
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The flow-performance relationship around the world
We use a new dataset to study how mutual fund flows depend on past performance across 28 countries. We show that there are marked differences in the flow-performance relationship across countries, suggesting that US findings concerning its shape do not apply universally. We find that mutual fund investors sell losers more and buy winners less in more developed countries. This is because investors in more developed countries are more sophisticated and face lower costs of participating in the mutual fund industry. Higher country-level convexity is positively associated with higher levels of risk taking by fund managers
Tuberculosis of the Gallbladder
Analysis of 5 patients with gallbladder tuberculosis
who had open cholecystectomy and review of
literature have shown that, although still rare it presents
as a part of systemic miliary tuberculosis,
abdominal tuberculosis, isolated gallbladder tuberculosis
and as acalculus cholecystitis in anergic
patients. There are no pathognomonic signs, the
diagnosis depends on suspicion of tuberculosis, peroperative
findings and histological examination
Effect of chemical structure on the sonochemical degradation of perfluoroalkyl and polyfluoroalkyl substances (PFASs)
Perfluoroalkyl surfactants include chemicals characterized by a fully fluorinated carbon chain (hydrophobic and oleophobic tail) bound to a hydrophilic head (a carboxyl or sulfonic group). These compounds are toxic and highly resistant to chemical/biological attack, and some are known to be bio-accumulative. This study investigates the sonochemical degradation at 500 kHz of different carboxylic and sulfonic perfluoroalkyl and polyfluoroalkyl substances (PFASs, 1.7 mM total organic fluorine) to assess the effect of chain length, functional head group, and substituents (–CH2–CH2– moiety and ether group) on the degradation rate. Under these conditions, the rates of defluorination determined for two widely used perfluoroalkyl substances, perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA), were 3.5 to 3.7 μM F− min−1, respectively. The degradation rate of perfluoroalkyl sulfonates decreased with the perfluorocarbon chain length as indicated by the 1.3 and 1.9-fold lower defluorination rates for perfluorohexane- and perfluorobutane sulfonate than that of PFOS. A similar trend was observed during the sonolysis of perfluoroalkyl carboxylate analogs with 6, 5 or 3 carbon atoms which had 1.1-, 1.8-, and 2.3-fold lower defluorination rates, respectively, than that of PFOA. Furthermore, perfluoroalkyl compounds appeared more amenable to sonolysis than the polyfluoroalkyl analogues with the same number of C atoms (defluorination rate of PFOS/6 : 2 fluorotelomer sulfonate ≈ 2.3). The results demonstrate that sonolysis is a promising approach to treat PFASs in aqueous streams. Furthermore, they underscore that the chemical structure of PFASs has a marked effect on the rate at which they undergo sonochemical degradation
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Uncertainty Avoidance and Mutual Funds
We study how culture influences mutual funds around the world. Uncertainty Avoidance (UA), which is related to ambiguity aversion, is negatively associated with flow-performance sensitivity, deviation from the fund benchmark, fund alpha, and the fraction of active management across the 25 countries in our sample. This is true even when controlling for an exhaustive set of fund- and country-level characteristics. We also find that a fund’s deviation from its benchmark is not only affected by the UA of its domicile country but also by the UA of its fund family’s country of origin. Our results highlight the importance of considering cultural characteristics, and UA in particular, when studying mutual funds across countries
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The equal-weight tilt in managed portfolios
Active portfolios can be more concentrated or more diversified than the market portfolio. In the latter case, the result is likely to be a tilt toward equal weights, which has been shown to have a systematic impact on portfolio returns. To capture this tilt, we use the difference between returns on equal-weighted and value-weighted portfolios for the relevant universe; we call this difference Equal-Minus-Value, or EMV. Despite EMV’s simplicity, its ability to explain mutual fund returns compares very favorably with that of the most popular performance evaluation factors. We therefore argue that EMV should be used in performance evaluation of broad market equity portfolios
A spatially-VSL gravity model with 1-PN limit of GRT
A scalar gravity model is developed according the 'geometric conventionalist'
approach introduced by Poincare (Einstein 1921, Poincare 1905, Reichenbach
1957, Gruenbaum1973). In principle this approach allows an alternative
interpretation and formulation of General Relativity Theory (GRT), with
distinct i) physical congruence standard, and ii) gravitation dynamics
according Hamilton-Lagrange mechanics, while iii) retaining empirical
indistinguishability with GRT. In this scalar model the congruence standards
have been expressed as gravitationally modified Lorentz Transformations
(Broekaert 2002). The first type of these transformations relate quantities
observed by gravitationally 'affected' (natural geometry) and 'unaffected'
(coordinate geometry) observers and explicitly reveal a spatially variable
speed of light (VSL). The second type shunts the unaffected perspective and
relates affected observers, recovering i) the invariance of the locally
observed velocity of light, and ii) the local Minkowski metric (Broekaert
2003). In the case of a static gravitation field the model retrieves the
phenomenology implied by the Schwarzschild metric. The case with proper source
kinematics is now described by introduction of a 'sweep velocity' field w: The
model then provides a hamiltonian description for particles and photons in full
accordance with the first Post-Newtonian approximation of GRT (Weinberg 1972,
Will 1993).Comment: v1: 11 pages, GR17 conf. paper, Dublin 2004, v2: WEP issue solved,
section on acceleration transformation added, text improved, more references,
same results, v3: typos removed, footnotes, added and references updated, v4:
appendix added, improved tex
Calibration and performance assessment of an innovative high-temperature cavitometer
This paper describes a series of systematic experimental studies to evaluate the performance of a high-temperature cavitometer under well-controlled conditions. The cavitometer was specifically designed for measurements in liquid metals: it operates through a long tungsten waveguide (probe), providing thermal protection to the piezo sensing elements placed outside the hot area, and with sufficient bandwidth to enable the monitoring of broadband acoustic emissions associated with cavitation activity. It was calibrated electrically, and acoustically, at kHz and MHz frequencies, and so can be used to estimate acoustic pressures (in Pa), providing physical, and consequently practical, meaning to cavitation measurements within liquid metals. Results obtained from ultrasonic sources in a cylindrical vessel using water showed that the cavitometer is a reliable and robust device for characterizing direct field acoustic pressures and broadband emissions from the resulting cavitation. Additionally, preliminary characterization of the real-time acoustic pressures during ultrasonic processing of liquid aluminium (Al) in a standard clay-graphite crucible were performed for the first time. The use of the calibrated cavitometer will establish a more generalized approach for measuring the actual acoustic pressures over a broad range of liquid temperatures within a sonicated medium, demonstrating its potential use as a tool for optimizing, controlling, and scaling-up processes
Erythropoietin overrides the triggering effect of DNA platination products in a mouse model of Cisplatin-induced neuropathy
<p>Abstract</p> <p>Background</p> <p>Cisplatin mediates its antineoplastic activity by formation of distinct DNA intrastrand cross links. The clinical efficacy and desirable dose escalations of cisplatin are restricted by the accumulation of DNA lesions in dorsal root ganglion (DRG) cells leading to sensory polyneuropathy (PNP). We investigated in a mouse model by which mechanism recombinant erythropoietin (rhEPO) protects the peripheral nervous system from structural and functional damage caused by cisplatin treatment with special emphasis on DNA damage burden.</p> <p>Results</p> <p>A cumulative dose of 16 mg cisplatin/kg resulted in clear electrophysiological signs of neuropathy, which were significantly attenuated by concomitant erythropoietin (cisplatin 32,48 m/s ± 1,68 m/s; cisplatin + rhEPO 49,66 m/s ± 1,26 m/s; control 55,01 m/s ± 1,88 m/s; p < 0,001). The co-application of rhEPO, however, did not alter the level of unrepaired cisplatin-DNA lesions accumulating in DRG target cells. Micro-morphological analyses of the sciatic nerve from cisplatin-exposed mice showed damaged myelin sheaths and mitochondria. Co-administered rhEPO inhibited myelin sheaths from structural injuries and resulted in an increased number of intact mitochondria.</p> <p>Conclusion</p> <p>The protective effect of recombinant erythropoietin is not mediated by reducing the burden of DNA platination in the target cells, but it is likely to be due to a higher resistance of the target cells to the adverse effect of DNA damage. The increased frequency of intact mitochondria might also contribute to this protective role.</p
High success rate of repeat colonoscopy with standard endoscopes in patients referred for prior incomplete colonoscopy
Clinical outcomes of EUS-guided drainage of debris-containing pancreatic pseudocysts: a large multicenter study
Background and study aims Data on clinical outcomes of endoscopic drainage of debris-free pseudocysts (PDF) versus pseudocysts containing solid debris (PSD) are very limited. The aims of this study were to compare treatment outcomes between patients with PDF vs. PSD undergoing endoscopic ultrasound (EUS)-guided drainage via transmural stents. Patients and methods Retrospective review of 142 consecutive patients with pseudocysts who underwent EUS-guided transmural drainage (TM) from 2008 to 2014 at 15 academic centers in the United States. Main outcome measures included TM technical success, treatment outcomes (symptomatic and radiologic resolution), need for endoscopic re-intervention at follow-up, and adverse events (AEs). Results TM was performed in 90 patients with PDF and 52 with PSD. Technical success: PDF 87 (96.7 %) vs. PSD 51 (98.1 %). There was no difference in the rates for endoscopic re-intervention (5.5 % in PDF vs. 11.5 % in PSD; P = 0.33) or AEs (12.2 % in PDF vs. 19.2 % in PSD; P = 0.33). Median long-term follow-up after stent removal was 297 days (interquartile range [IQR]: 59 - 424 days) for PDF and 326 days (IQR: 180 - 448 days) for PSD (P = 0.88). There was a higher rate of short-term radiologic resolution of PDF (45; 66.2 %) vs. PSD (21; 51.2 %) (OR = 0.30; 95 % CI: 0.13 - 0.72; P = 0.009). There was no difference in long-term symptomatic resolution (PDF: 70.4 % vs. PSD: 66.7 %; P = 0.72) or radiologic resolution (PDF: 68.9 % vs. PSD: 78.6 %; P = 0.72) Conclusions There was no difference in need for endoscopic re-intervention, AEs or long-term treatment outcomes in patients with PDF vs. PSD undergoing EUS-guided drainage with transmural stents. Based on these results, the presence of solid debris in pancreatic fluid collections does not appear to be associated with a poorer outcome
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