2,773 research outputs found
ESTIMATION OF FURAN LEVELS IN SOME CANNED FOODS IN EGYPT AND HOW TO REDUCE IT
Furan is naturally occurring compound found at low levels in many foods. Furan has been formed in a wide range of thermally treated foods especially heated foods sealed in cans and jars. The primary source of furan in food is thermal degradation and rearrangement of organic compounds. Furan is a five-membered ring which can induce tumors and liver toxicity in experimental animals and is classified as ‘possibly carcinogenic to humans’ by the International Agency for Research on Cancer. In this study furan levels in several kinds of canned and jarred foods from Egyptian markets have been estimated. Also, several heat treatments have been applied for some food samples aiming to reduce furan content in these samples. Noticed levels of furan have been shown in tested samples. Coffee samples had higher content of furan in comparison to other products. After thermal treatments the obtained results show that, furan content reduced to about 38-50% of the original content for 50o C at 5 min and the loss percent raised to about 55-71% at 20 min. At 60o C, furan content reduced to about 47-56% of the original content at 5 min and the loss percent raised to about 62-78% at 20 min. And at 70o C, furan content reduced to about 53-59% at 5 min and the loss percent raised to about 70-89% at 20 min
Advanced Electrodes for Solid Acid Fuel Cells by Platinum Deposition on CsH_(2)PO_4
We demonstrate cathodes for solid acid fuel cells fabricated by vapor deposition of platinum from the metalorganic precursor Pt(acac)_2 on the solid acid
CsH_(2)PO_4 at 210 °C. A network of platinum nanoparticles with diameters of 2−4 nm serves as both the oxygen reduction catalyst and the electronic conductor in the electrode. Electrodes with a platinum content of 1.75 mg/cm^2 are more active for oxygen reduction than previously reported electrodes with a platinum content of 7.5 mg/cm^2. Electrodes containing <1.75 mg/cm^2 of platinum show significantly reduced catalytic activity and increased ohmic resistance indicative of a highly discontinuous catalytic-electronic platinum network
Search for the production of dark fermion candidates in association with heavy neutral gauge boson decaying to dimuon in proton-proton collisions at TeV using the CMS open data
This analysis shows a search for dark fermion particles produced in
association with a heavy neutral gauge boson (Z). The studied events
topology are dimuon and a large missing transverse momentum. %We considered the
muonic decay of Z. The analyzed data were the Open Data collected by
the CMS detector in proton-proton collisions at the LHC in 2012 and correspond
to an integrated luminosity of 11.6 fb at 8 TeV. One
benchmark scenario the light vector was used for interpreting the data, based
on a simplified model so called the mono-Z model. No evidence of
dark fermion candidates was found, 95 confidence level limits have been set
on both Z and dark fermion masses.Comment: 10 pages. arXiv admin note: substantial text overlap with
arXiv:2103.04326, arXiv:2109.1127
Experience with impacted upper ureteral Stones; should we abandon using semirigid ureteroscopes and pneumatic lithoclast?
<p>Abstract</p> <p>Introduction</p> <p>The AUA/EAU Ureteral Stones Guideline Panel reported that the stone free rate for the proximal ureteral stones is around 81% when treated by either SWL or ureteroscopy (URS).</p> <p>Complication rates, most notably ureteral perforation and long-term complications of URS such as stricture formation rates, have been reduced to < 5%. Moreover, impacted ureteral calculi are more difficult to fragment with SWL because of the lack of natural expansion space for stones, this result in a situation that is better managed by ureteroscopy. The aim of this study is to assess the efficacy, safety, and complications of impacted upper ureteral stone disintegration using semirigid ureteroscopes and pneumatic lithotripsy.</p> <p>Methods</p> <p>We retrospectively analyzed the records of 267 consecutive patients with impacted upper ureteral stones (9–20 mm) who were treated by semirigid ureteroscopes and pneumatic disintegration. The efficacy of treatment was estimated using the stone-free rate and all treatment related complications were analyzed.</p> <p>Results</p> <p>Except for 24 cases where the stone migrated to the kidney, the stone was successfully treated ureteroscopically, with a low rate of minimal complications such as mild hematuria (18.4%), short term low grade fever (13.5%). Only 3 patients (1.1%) had high grade fever and none had post operative stricture.</p> <p>Conclusion</p> <p>The use of semirigid URS and pneumatic lithotripsy in impacted upper ureteral stones in experienced hands has very satisfactory results with minimal complications. When Holmium laser and flexible URS are not available, semirigid URS and pneumatic lithotripsy is a good alternative that shouldn't, yet, be abandoned.</p
On landmark selection and sampling in high-dimensional data analysis
In recent years, the spectral analysis of appropriately defined kernel
matrices has emerged as a principled way to extract the low-dimensional
structure often prevalent in high-dimensional data. Here we provide an
introduction to spectral methods for linear and nonlinear dimension reduction,
emphasizing ways to overcome the computational limitations currently faced by
practitioners with massive datasets. In particular, a data subsampling or
landmark selection process is often employed to construct a kernel based on
partial information, followed by an approximate spectral analysis termed the
Nystrom extension. We provide a quantitative framework to analyse this
procedure, and use it to demonstrate algorithmic performance bounds on a range
of practical approaches designed to optimize the landmark selection process. We
compare the practical implications of these bounds by way of real-world
examples drawn from the field of computer vision, whereby low-dimensional
manifold structure is shown to emerge from high-dimensional video data streams.Comment: 18 pages, 6 figures, submitted for publicatio
Credit risk in Islamic microfinance institutions: The role of women, groups, and rural borrowers
Using international data, we find that Islamic MFIs experience reduced credit risk by offering more groups loans, serving more women, and serving more borrowers in rural locations. Conventional MFIs benefit from fewer group loans, less loans to rural borrowers, and a greater focus on female borrowers. Our results contribute to microfinance and financial inclusion literature by highlighting the potential of tapping into the social dynamics within Muslim communities. We present encouraging insights for Islamic MFIs donors and managers on the possibility of promoting the financial inclusion of women and rural borrowers without compromising the quality of the credit portfolio
Homocysteine, folic acid and vitamin B12 levels in serum of epileptic children
AbstractThe relationship between increased homocysteine (Hcy) level and epileptic seizure remains controversial in human, despite a growing evidence of the pro-convulsive effect of the hyperhomocysteinemia (HHcy) observed in the animal studies. The mechanism of this association with epileptogenesis has not been clearly understood, although there is emerging evidence to support the unfavorable effects of some anti-epileptic drugs (AEDs) on the plasma homocysteine (Hcy) concentrations. The aim of this study was to uncover the relationship between the levels of homocysteine (Hcy), the cofactors involved in its metabolism as folic acid and vitamin B12 and anti-epileptic drugs (AEDs) in epileptic patients. Serum level of homocysteine (Hcy), folic acid and vitamin B12 was measured in 60 patients with idiopathic epilepsy; and its level was compared to 30 healthy children serving as control group. No significant difference was found regarding the plasma homocysteine (Hcy) levels between patients (both receiving anti-epileptics and non anti-epileptic drug users) and controls. Epileptic patients on polytherapy showed higher mean serum levels of homocysteine (Hcy) and lower mean serum levels of folic acid compared to those on monotherapy. However, the mean serum levels of homocysteine (Hcy), vitamin B12 and folic acid showed non significant differences between patients using valproic acid (VPA) or carbamazepine (CBZ). Duration of AED therapy showed a significant positive correlation with mean serum levels of homocysteine (Hcy) and a significant negative correlation with mean serum levels of folic acid. To conclude; AEDs upset the homeostatic balance of homocysteine (Hcy) and its cofactors and cause abnormalities in their serum levels
Rational functions: an alternative approach to asset pricing
This paper shows that asset prices are linear polynomials of various underlying explanatory factors and asset returns being ratios of these polynomials, are rational functions that do not add linearly when averaging. Hence, average returns should be modeled based on stock prices. However, continuous returns may be treated as approximately linear across time and modeled directly. Our new Rational Function (RF) models, empirically outperform the traditional asset pricing models like the Capital Asset Pricing Model (CAPM) and the Fama–French three and five-factor models for both average and continuous returns. Moreover, the RF theory also provides a model to estimate the asset volumes. The average change in asset volumes together with average returns provide the estimates for average change in market values of assets. Thus, the RF model approach can be used to select assets that provide either highest returns for profit maximization or highest change in market values for wealth maximization for given levels of risk
Study of one class boundary method classifiers for application in a video-based fall detection system
In this paper, we introduce a video-based robust fall detection system for monitoring an elderly person in a smart room environment. Video features, namely the centroid and orientation of a voxel person, are extracted. The boundary method, which is an example one class classification technique, is then used to determine whether the incoming features lie in the ‘fall region’ of the feature space, and thereby effectively distinguishing a fall from other activities, such as walking, sitting, standing, crouching or lying. Four different types of boundary methods, k-center, k-th nearest neighbor, one class support vector machine and single class minimax probability machine are assessed on representative test datasets. The comparison is made on the following three aspects: 1). True positive rate, false positive rate and geometric means in detection 2). Robustness to noise in the training dataset 3). The computational time for the test phase. From the comparison results, we show that the single class minimax probability machine achieves the best overall performance. By applying one class classification techniques with 3-d features, we can obtain a more efficient fall detection system with acceptable performance, as shown in the experimental part; besides, it can avoid the drawbacks of other traditional fall detection methods
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