461 research outputs found
Mutual funds, fee transparency, and competition
Mutual funds enable small, less experienced investors to hold diversified portfolios of stocks and bonds at relatively low costs. Though the mutual fund market is competitive in many ways, fees can vary substantially for what are essentially identical products. This may be due to bundling of services, but it may also reflect some confusion on the part of less experienced investors, which inhibits comparative shopping among funds. Suggested reforms for improved fee disclosure seek to make fees more transparent for less informed investors and should improve competitive discipline among funds.Mutual funds
Evaluation of the Minimum Effective Concentration of Foam Sclerosant in an Ex-vivo Study
AbstractBackgroundFoam sclerosants are widely used in sclerotherapy and have been accepted as more effective than the liquid form; however, there is no consensus about the most applicable and effective concentration.ObjectiveThe aim of this study was to investigate the histopathological changes caused by various widely used concentrations of foam sclerosant.MethodsFifty-six varicose vein segments of 5–10 mm diameter were gently resected and exposed to various concentrations of foam sclerosant (0.5%, 1%, 2%, 3%) for 5 min, and were then prepared for routine histopathological examination. A total damage scoring system, including the presence of endothelial swelling, intimal thickening, cellular vacuolization in the muscle layer, edema in the tunica media and extent of necrosis, was established.ResultsThe total damage score of the foam sclerosant groups was significantly higher than that of the control group (median 2.75 vs 1, p = 0.007). The highest damage score was achieved by 1% and 2% foam sclerosants (3.5 and 2.5). No significant difference was found among the different concentrations of sclerosant, although the 1% group caused more severe damage at a near significant level (p = 0.074).ConclusionSignificant pathological damage can be caused by even the lowest doses of foam sclerosant. The most injurious concentrations were found to be 1% and 2%, morphologically. A working concentration of 1% could thus be preferable to 0.5%, especially in larger veins. Further in-vivo studies are needed in order to validate these findings
Password-conditioned Anonymization and Deanonymization with Face Identity Transformers
Cameras are prevalent in our daily lives, and enable many useful systems
built upon computer vision technologies such as smart cameras and home robots
for service applications. However, there is also an increasing societal concern
as the captured images/videos may contain privacy-sensitive information (e.g.,
face identity). We propose a novel face identity transformer which enables
automated photo-realistic password-based anonymization as well as
deanonymization of human faces appearing in visual data. Our face identity
transformer is trained to (1) remove face identity information after
anonymization, (2) make the recovery of the original face possible when given
the correct password, and (3) return a wrong--but photo-realistic--face given a
wrong password. Extensive experiments show that our approach enables multimodal
password-conditioned face anonymizations and deanonymizations, without
sacrificing privacy compared to existing anonymization approaches.Comment: ECCV 202
X-ray magnetic circular dichroism in (Ge,Mn) compounds: experiments and modeling
X-ray absorption (XAS) and x-ray magnetic circular dichroism (XMCD) spectra
at the L edges of Mn in (Ge,Mn) compounds have been measured and are
compared to the results of first principles calculation. Early \textit{ab
initio} studies show that the Density Functional Theory (DFT) can very well
describe the valence band electronic properties but fails to reproduce a
characteristic change of sign in the L XMCD spectrum of Mn in
GeMn, which is observed in experiments. In this work we demonstrate
that this disagreement is partially related to an underestimation of the
exchange splitting of Mn 2 core states within the local density
approximation. It is shown that the change in sign experimentally observed is
reproduced if the exchange splitting is accurately calculated within the
Hartree-Fock approximation, while the final states can be still described by
the DFT. This approach is further used to calculate the XMCD in different
(Ge,Mn) compounds. It demonstrates that the agreement between experimental and
theoretical spectra can be improved by combining state of the art calculations
for the core and valence states respectively.Comment: 8 page
A Scale-out Blockchain for Value Transfer with Spontaneous Sharding
Bitcoin, as well as many of its successors, require the whole transaction
record to be reliably acquired by all nodes to prevent double-spending.
Recently, many blockchains have been proposed to achieve scale-out throughput
by letting nodes only acquire a fraction of the whole transaction set. However,
these schemes, e.g., sharding and off-chain techniques, suffer from a
degradation in decentralization or the capacity of fault tolerance.
In this paper, we show that the complete set of transactions is not a
necessity for the prevention of double-spending if the properties of value
transfers is fully explored. In other words, we show that a value-transfer
ledger like Bitcoin has the potential to scale-out by its nature without
sacrificing security or decentralization. Firstly, we give a formal definition
for the value-transfer ledger and its distinct features from a generic
database. Then, we introduce an off-chain based scheme with a shared main chain
for consensus and an individual chain for each node for recording transactions.
A locally executable validation scheme is proposed with uncompromising validity
and consistency. A beneficial consequence of our design is that nodes will
spontaneously try to reduce their transmission cost by only providing the
transactions needed to show that their transactions are double-spending-proof.
As a result, the network is sharded as each node only acquires part of the
transaction record and a scale-out throughput could be achieved, which we call
"spontaneous sharding".Comment: Accepted by Crypto Valley Conference for Blockchain Technology 201
Security and Efficiency Analysis of the Hamming Distance Computation Protocol Based on Oblivious Transfer
open access articleBringer et al. proposed two cryptographic protocols for the computation of Hamming distance. Their first scheme uses Oblivious Transfer and provides security in the semi-honest model. The other scheme uses Committed Oblivious Transfer and is claimed to provide full security in the malicious case. The proposed protocols have direct implications to biometric authentication schemes between a prover and a verifier where the verifier has biometric data of the users in plain form.
In this paper, we show that their protocol is not actually fully secure against malicious adversaries. More precisely, our attack breaks the soundness property of their protocol where a malicious user can compute a Hamming distance which is different from the actual value. For biometric authentication systems, this attack allows a malicious adversary to pass the authentication without knowledge of the honest user's input with at most complexity instead of , where is the input length. We propose an enhanced version of their protocol where this attack is eliminated. The security of our modified protocol is proven using the simulation-based paradigm. Furthermore, as for efficiency concerns, the modified protocol utilizes Verifiable Oblivious Transfer which does not require the commitments to outputs which improves its efficiency significantly
The Propagation of Thermoelastic Waves in Anisotropic Media of Orthorhombic, Hexagonal, and Tetragonal Syngonies
The investigation of wave propagation in elastic medium with thermomechanical effects is bound to have important economic implications in the field of composite materials, seismology, geophysics, and so on. In this article, thermoelastic wave propagation in anisotropic mediums of orthorhombic and hexagonal syngony having heterogeneity along z-axis is studied. Such medium has second-order axis symmetry. By using analytical matriciant method, a set of equations of motions in thermoelastic medium are reduced to an equivalent set of the first-order differential equations. In the general case, for the given set of equations, structures of fundamental solutions are made and dispersion relations are obtained
Uroflowmetric Monitoring and its Role in Evaluating the Results of Surgical Treatment in Children with Urethral Valves
This paper presents the results of research and treatments in 41 children (from two months to 15 years of age) with urethral valves. In all, 16 patients were treated using the endoscopic method, 7 patients by employing the polyethylene urethrotome and 18 patients treated by the proposed method, using a metallic urethrotome. Diagnosis of the urethral valves was done using ultrasonography, voiding cystourethrogram, urethrocystoscopy, uroflowmetry and cystomanometry. Mathematical modeling was applied to assess the treatment methods. The proposed method, using the metallic urethrotome, was preferable to the endoscopic method
An association between TRP64ARG polymorphism of the B3 adrenoreceptor gene and some metabolic disturbances
<p>Abstract</p> <p>Backgrounds</p> <p>B3 adrenoreceptors (ADRB3) are abundant in adipose tissue and play the role in its metabolism and lipolysis. Some variants of the ADRB3 gene may predispose subjects for the development obesity and metabolic abnormalities in the setting of modern sedentary lifestyle. ADRB3 gene polymorphism association with metabolic disturbances has never been studied before in the ethnic Kyrgyz population.</p> <p>Aim</p> <p>To study an association between Trp64Arg polymorphism of the ADRB3 and metabolic syndrome (MS) components in an ethnic Kyrgyz group.</p> <p>Materials and methods</p> <p>213 Ethnic Kyrgyz volunteers over the age of 30 were enrolled in the study. The assessment plan for each individual comprised of general physical and anthropometric exams as well as laboratory tests (glucose, lipid panel, insulin) and genotyping by Trp64Arg polymorphism of the ADRB3. MS diagnosis was consistent with modified ATP III criteria (2005). Logistic regression analysis was performed to test the potential independent association between Arg64 allele with obesity, abdominal obesity (AO) and arterial hypertension (AH).</p> <p>Results</p> <p>Trp64Arg polymorphism of the ADRB3 was assessed in 213 individuals (145 men, 68 women) aged 30-73 (mean age 50.7 ± 7.6). Arg64 allele frequency was 0.239; ADRB3 genotype distribution among participants was: Trp64 homozygotes 54.5%, Trp64Arg 43.2% and Arg64 homozygotes 2.3%. There was an association between Trp64Arg и Arg64Arg genotypes and higher BMI, WC and obesity frequency (p < 0.00009), AO (p < 0.01), type 2 diabetes mellitus (DM) (p < 0.005) and lower high density cholesterol (HDL-C) level (p < 0.03). The logistic regression analysis showed the correlation of the Arg64 allele with obesity (OR 3.159; 95% CI 1.789-5.577) and AO (OR 1.973; 95% CI 1.118-3.481). The association between Arg64 allele and AH lost its significance after adjustment for obesity.</p> <p>Conclusion</p> <p>Arg64 allele of the ADRB3 gene in the studied group has an association with MS components such as obesity, AO and decreased HDL-C level.</p
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