1,230 research outputs found
Currency Substitution: New Evidence from Emerging Economies
Cataloged from PDF version of article.This paper provides new empirical evidence for currency substitution in different emerging market economies. Estimation results from a money-in-the-utility-function framework indicate that foreign currencies are strong substitutes for domestic currency in producing liquidity services. (C) 2002 Elsevier Science B.V. All rights reserved
Overnight Borrowing, Interest Rates and Extreme Value Theory
Cataloged from PDF version of article.We examine the dynamics of extreme values of overnight borrowing rates in an inter-bank money market before a financial crisis during which overnight borrowing rates rocketed up to (simple annual) 4000 percent. It is shown that the generalized Pareto distribution fits well to the extreme values of the interest rate distribution. We also provide predictions of extreme overnight borrowing rates using pre-crisis data. The examination of tails (extreme values) provides answers to such issues as to what are the extreme movements to be expected in financial markets; is there a possibility for even larger movements and, are there theoretical processes that can model the type of fat-tails in the observed data? The answers to such questions are essential for proper management of financial exposures and laying ground for regulations. (c) 2005 Elsevier B.V. All rights reserved
Extreme value theory and Value-at-Risk: Relative performance im emerging markets
Cataloged from PDF version of article.In this paper, we investigate the relative performance of Value-at-Risk (VaR) models with the daily stock market returns of nine different emerging markets. In addition to well-known modeling approaches, such as variance-covariance method and historical simulation, we study the extreme value theory (EVT) to generate VaR estimates and provide the tail forecasts of daily returns at the 0.999 percentile along with 95% confidence intervals for stress testing purposes. The results indicate that EVT-based VaR estimates are more accurate at higher quantiles. According to estimated Generalized Pareto Distribution parameters, certain moments of the return distributions do not exist in some countries. In addition, the daily return distributions have different moment properties at their right and left tails. Therefore, risk and reward are not equally likely in these economies. (C) 2004 International Institute of Forecasters. Published by Elsevier B.V. All rights reserved
Multiscale Systematic Risk
Cataloged from PDF version of article.In this paper we propose a new approach to estimating systematic risk (the beta of an asset). The proposed method is based on a wavelet multiscaling approach that decomposes a given time series on a scale-by-scale basis. The empirical results from different economies show that the relationship between the return of a portfolio and its beta becomes stronger as the wavelet scale increases. Therefore, the predictions of the CAPM model should be investigated considering the multiscale nature of risk and return. (C) 2004 Elsevier Ltd. All rights reserved
Effects of stress produced by adrenocorticotropin (ACTH) on lipid peroxidation and some antioxidants in vitamin C treated and nontreated chickens
The aim of this study was to examine the effects of vitamin C on malonaldehyde (MDA) and glutathione (GSH) concentrations, and superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity in chickens stressed by adrenocorticotropin (ACTH). Sixty Leghorn chickens (20 weeks old) were randomly allotted to a control and a vitamin C treated group. An isotonic sodium chloride solution was administrated intramuscularly for a period of five days to the control group at a dose of 2.5 mL per chicken per day, and the treatment group received a vitamin C solution (containing 250 mg vitamin C/2.5 mL) intramuscularly for five days. On the fifth day of the experiment the chickens in both groups received 50 IU ACTH intramuscularly. Three hours after ACTH application blood samples were collected to determine the concentrations of MDA and GSH, and activities of SOD and GSH-Px in the blood. The concentration of MDA in the control group increased compared to that in the vitamin C treated group. After the ACTH application the activity of SOD increased in both groups, thought significantly so in the vitamin C treated group. The GSH-Px activity did not differ significantly between the treatments after ACTH application. It was concluded that intramuscularly administrated vitamin C facilitated an adaptation against stress and decreased negative effects of stress in chickens.
Keywords: ACTH, glutathione (GSH), Glutathione peroxidase (GSH-Px), Malonaldehyde (MDA), Superoxide dismutase (SOD), Vitamin C
South African Journal of Animal Science Vol.33(3) 2003: 201-20
Dissolution kinetics and mechanism of pandermite in acetic acid solutions
In this study, the dissolution kinetics and mechanism of pandermite mineral was investigated using a batch reactor employing the parameters of particle size, acid concentration, solid/liquid ratio, stirring speed and reaction temperature. From experimental data, it was determined that the conversion rate of pandermite to boric acid was increased with decreasing particle size, solid/ liquid ratio and increasing reaction temperature. Conversion rate increased up to 3 M, acid concentration then decreased with increasing acid concentration.It was observed that there was no important effect of stirring speed on the dissolution rate. Furthermore, it was observed that the dissolution mechanism was dependent on acid concentration due to restriction of dissolution in acetic acid solutions. The dissolution rate of pandermite mineral in acetic acid solution was examined according to homogeneous and heterogeneous chemical reaction model. It was determined from graphical and statistical methods that the reaction kinetics fitted to model in the form of first order pseudo homogeneous model [- ln (1 - X)] = kt and activation energy for the dissolution process was found to be 28.496 kj/mol. A mathematicalmodel, which indicated the dissolution process was established
Beyond Images: An Integrative Multi-modal Approach to Chest X-Ray Report Generation
Image-to-text radiology report generation aims to automatically produce
radiology reports that describe the findings in medical images. Most existing
methods focus solely on the image data, disregarding the other patient
information accessible to radiologists. In this paper, we present a novel
multi-modal deep neural network framework for generating chest X-rays reports
by integrating structured patient data, such as vital signs and symptoms,
alongside unstructured clinical notes.We introduce a conditioned
cross-multi-head attention module to fuse these heterogeneous data modalities,
bridging the semantic gap between visual and textual data. Experiments
demonstrate substantial improvements from using additional modalities compared
to relying on images alone. Notably, our model achieves the highest reported
performance on the ROUGE-L metric compared to relevant state-of-the-art models
in the literature. Furthermore, we employed both human evaluation and clinical
semantic similarity measurement alongside word-overlap metrics to improve the
depth of quantitative analysis. A human evaluation, conducted by a
board-certified radiologist, confirms the model's accuracy in identifying
high-level findings, however, it also highlights that more improvement is
needed to capture nuanced details and clinical context
DIVERSITY OF MICROFUNGI ON FAGACEAE IN ULUDAG FORESTS
WOS: 000363091600042Forests ecosystems are sources of oxygen and wood products, also they prevent soil erosion, improve water and air quality, serve as homes for wildlife; and therefore, they preserve and increase biodiversity. Forests can host a diverse community of fungal species with various effects on their host trees. In this research, trees of Fagaceae family of Uludag forests of Bursa province were investigated between the years of 2002 and 2008. By microscopic examination we identified 38 microfungi species in 27 genera belongs to Ascomycota and 1 microfungus species in 1 genus belongs to Basidiomycota. The taxa belong to 15 families: Botryosphaeriaceae, Diaporthaceae, Diatrypaceae, Dothioraceae, Erysiphaceae, Gnomoniaceae, Incertae sedis, Melanconidaceae, Microstromataceae, Nectriaceae, Pseudovalsaceae, Rhytismataceae, Trichosphaeriaceae, Valsaceae and Xylariaceae. The distribution of species by trophic groups revealed a dominance of xylotrophic species. With this study, fungal diversity of Fagaceae family in Uludag forests was identified and included in the mycobiota of Turkey
Organophilic, Superparamagnetic, and Reversibly Thermoresponsive Silica-Polypeptide Core-Shell Particles
Particles with a superparamagnetic cobalt inner core, silica outer core, and covalently bound homopolypeptide shell were investigated under thermal and magnetic stimuli. The homopolypeptide was poly(ϵ-carbobenzyloxy-l-lysine), PCBL, which is known to exhibit a thermoreversible coil → helix transition when dissolved as a pure polymer in m-cresol. Tethering to a core particle did not prevent PCBL from undergoing this conformational transition, as confirmed by dynamic light scattering and optical rotation, but the transition was broadened compared to that of the untethered polymer. The Co@SiO2-PCBL hybrid particles retained the superparamagnetic properties of the cobalt inner nougat. Indeed, some response remains even after aging for \u3e5 years. The aged PCBL shell also preserved its responsiveness to temperature, although differences in the shape of the size vs temperature transition curve were observed compared to the freshly made particles. A reversible coil → helix transition for a particle-bound polypeptide in a pure organic solvent is rare. In addition to providing a convenient tool for characterizing coil → helix transitions for surface-bound polypeptides without interference from pH or the strong ionic forces that dominate behavior in aqueous systems, the Co@SiO2-PCBL/m-cresol system may prove useful in studies of the effect of shell polymer conformation on colloid interactions. The stability of the magnetic core and polypeptide shell suggest a long shelf life for Co@SiO2-PCBL, which can, in principle, be deprotected to yield positively charged Co@SiO2-poly(l-lysine) particles for possible transfection or antimicrobial applications or chained magnetically to produce responsive poly(colloids)
Effects of stock density on texture-colour quality and chemical composition of rainbow trout (Oncorhynchus mykiss)
This study describes the effects of different stocking densities on texture/colour characteristics, protein content/amino acid and lipid content/fatty acid composition of rainbow trout fillet. Stocking density was selected 5 (Group A), 15 (Group B), 25 (Group C) kg fish m^−3. Tukey’s Multiple Comparison Test showed insignificant differences between measured size/weight measurement and condition factors. No significant differences were found between A and C groups for colour analysis (L* and a* value) and texture profile analysis (hardness, adhesiveness, cohesiveness and gumminess values) of rainbow trout fillets. The proximate composition analysis showed rainbow trout fillets from the A and C groups to exhibit higher values of moisture than the B group. Fish from the A and B groups had a lower of ash and protein in comparison to C group samples. The highest fat values of rainbow trout were measured in B group samples. The content essential amino acid and non-essential amino acid was lower in A and B groups than in C groups. Fish from the C group had higher content of polyunsaturated fatty acids, especially n-3, docosahexanoic acid (DHA) and eicosapentaenoic acid (EPA) in comparison to A and C group. As a result, 25 kg fish m^−3 is recommended stock density in terms of product texture/color and composition quality
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