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Análise da modulação autonômica do coração em repouso e atividade eletromiográfica relacionada à variabilidade da frequência cardíaca durante o exercício dinâmico em cicloergômetro ; Analysis of the autonomic modulation of the heart in rest and activity electromyographic related the heart rate variability during dynamic exercise in cicle ergometer

Silva, Cristiano Sales da
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 22/11/2002 PT
Relevância na Pesquisa
35.91%
A variabilidade da freqüência cardíaca (VFC) tem sido utilizada como um marcador fisiológico do controle autonômico do coração, enquanto a eletromiografia de superfície (EMGs) tem mostrado ser uma ferramenta útil de análise para avaliar a resposta muscular frente ao exercício físico. Assim os objetivos do presente estudo foram: avaliar o controle autonômico do coração a partir das respostas da freqüência cardíaca e de sua variabilidade nas condições de repouso, nas posições supina e sentada, e durante teste de esforço físico dinâmico contínuo do tipo rampa (TEFDC-R). Avaliar a atividade eletromiográfica durante o TEFDC-R e ainda verificar a correlação entre a atividade eletromiográfica e a variabilidade da freqüência cardíaca durante o TEFDC-R. Metodologia: estudou se 10 homens, ativos, saudáveis, jovens (23,7 ± 3,02 anos) em repouso, nas posições supina e sentada, e durante TEFDC-R, com incrementos de 20 Watts (W) por minuto. Os dados de freqüência cardíaca e dos intervalos R-R (ms) foram coletados em tempo real, batimento a batimento, durante o repouso e o exercício. A EMGs integrada foi coletada do músculo vasto lateral (VL) nos 20 segundos finais de cada minuto durante o TEFDC-R. Análise dos dados: foram calculados os valores médios da freqüência cardíaca (FC) em bpm e dos intervalos R-R (iR-R) em ms em repouso durante os 15 minutos e o índice temporal RMSSD dos iR-R (ms) e da FC (bpm) nessas condições. Durante o TEFDC-R...

Effects of timing of induced luteolysis in embryo donor mares on reproductive performance and pregnancy rate in recipient mares

Goretti, R. G.; Araujo, R. R.; Rocha Filho, A. N.; Araujo, G. H. M.; Lopes, E. P.; Guimaraes, J. D.
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 1170-1174
ENG
Relevância na Pesquisa
35.95%
The objective was to evaluate the effects of giving prostaglandin F(2 alpha) (PGF) to donor mares 48 h prior to embryo collection. Non-lactating donor mares (n = 20 estrous cycles in 10 mares), ranging from 2.5 to 10 y of age and 400 to 500 kg of body weight were used from September 2004 to February 2005 in the southern hemisphere (Brazil). Donor mares were randomly assigned in a cross-over design study. During a Treated cycle, 7.5 mg PGF was given 48 h prior to embryo collection, whereas in the Control cycle, 7.5 mg PGF was given at embryo collection. In Treated Cycles, serum progesterone concentrations decreased between the day of PGF treatment and the day of embryo collection (13.9 +/- 5.4 and 0.5 +/- 0.3 ng/mL, respectively; P < 0.05). In Treated versus Control cycles, the interovulatory interval was shorter (14.9 +/- 0.9 vs 17.5 +/- 1.1 d, P < 0.05). However, there was no significant difference between these groups for the interval from PGF to ovulation (average, 9.8 d), embryo recovery rate (average, 75%), embryo quality, uterine protein concentration, and pregnancy rate in recipient mares (average, 87% at 15 d after ovulation, with no pregnancy loss detected by 60 d). In conclusion, giving donor mares PGF 48 h prior to embryo collection reduced the average interovulatory interval by approximately 2.5 d...

One-dimensional viscoelastic fluid model where viscosity and normal stress coeffients depend on the shear rate

Carapau, Fernando
Fonte: F. Carapau, "One-dimensional viscoelastic fluid model where viscosity and normal stress coeffients depend on the shear rate",Nonlinear Analysis:Real World Applications, Volume 11, Issue 5, pp. 4342-4354, 2010. Publicador: F. Carapau, "One-dimensional viscoelastic fluid model where viscosity and normal stress coeffients depend on the shear rate",Nonlinear Analysis:Real World Applications, Volume 11, Issue 5, pp. 4342-4354, 2010.
Tipo: Artigo de Revista Científica
POR
Relevância na Pesquisa
45.89%
Westudy the unsteady motion of a viscoelastic fluid modeled by a second-order fluid where normal stress coefficients and viscosity depend on the shear rate by using a power-law model. To study this problem, we use the one-dimensional nine-director Cosserat theory approach which reduces the exact three-dimensional equations to a system depending only on time and on a single spatial variable. Integrating the equation of conservation of linear momentum over the tube cross-section, with the velocity field approximated by the Cosserat theory, we obtain a one-dimensional system. The velocity field approximation satisfies both the incompressibility condition and the kinematic boundary condition exactly. From this one-dimensional system we obtain the relationship between average pressure and volume flow rate over a finite section of the tube with constant and variable radius. Also, we obtain the correspondent equation for the wall shear stress which enters directly in the formulation as a dependent variable. Attention is focused on some numerical simulation of unsteady/steady flows for average pressure, wall shear stress and on the analysis of perturbed flows.

The Spontaneous-Rate Histogram of the Auditory Nerve Can Be Explained by Only Two or Three Spontaneous Rates and Long-Range Dependence

Jackson, B. Scott; Carney, Laurel H.
Fonte: Springer-Verlag Publicador: Springer-Verlag
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
35.91%
Estimates of the spontaneous discharge rate (SR) of auditory-nerve (AN) fibers are often based on measurements of the average rate over a long (e.g., 30 s) interval. These measurements are important because SR is apparently correlated with other AN properties, such as threshold to acoustic stimuli, shape of rate-level function, recovery from prior stimulation, and certain anatomical characteristics. Furthermore, histograms of SR estimates from large numbers of fibers suggest that they can be divided into two (i.e., low and high) or three (i.e., low, medium, and high) SR classes. Yet, even “simple” statistical estimates, such as average rate, can behave surprisingly poorly for processes with long-range dependence (LRD), which has been found in the spontaneous activity of AN fibers. In particular, LRD greatly increases the variability of estimates of mean discharge rate. We investigated the implications of this effect of LRD for our understanding of the SRs of AN fibers. The fractional-Gaussian-noise-driven Poisson process (fGnDP) was originally developed to model the LRD action-potential trains of AN fibers. Using rate estimates computed from this model, we were able to reproduce the shape of published histograms of SR using only three fixed SR values. Moreover...

The Social Discount Rate : Estimates for Nine Latin American Countries

Lopez, Humberto
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
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35.96%
The social discount rate measures the rate at which a society would be willing to trade present for future consumption. As such it is one of the most critical inputs needed for cost-benefit analysis. This paper presents estimates of the social discount rates for nine Latin American countries. It is argued that if the recent track record in terms of growth in the region is indicative of future performance, estimates of the social discount rate would be in the 3-4 percent range. However, to the extent that the region improves on its past performance, the social discount rate to be used in the evaluation of projects would increase to the 5-7 percent range. The paper also argues that if the social planner gives a similar chance to the low and high growth scenario, the discount rate should be dependent on the horizon of the project, declining from 4.4 percent for a 25-year horizon to less than 4 percent for a 100-year horizon.

Can We Discern the Effect of Globalization on Income Distribution? Evidence from Household Surveys

Milanovic, Branko
Fonte: Published by Oxford University Press on behalf of the World Bank Publicador: Published by Oxford University Press on behalf of the World Bank
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
36.01%
New data derived directly from household surveys are used to examine the effects of globalization on income distribution in poor and rich countries. The article looks at the impact of openness and of direct foreign investment on relative income shares across the entire income distribution. It finds strong evidence that at low average income levels, the income share of the poor is smaller in countries that are more open to trade. As national income levels rise, the incomes of the poor and the middle class rise relative to the income of the rich. The article explains why using the trade to gross domestic product (GDP) ratio in purchasing power parity terms, as favored by some analysts, is inappropriate in studies of the effect of trade on income distribution.

Climate Change and Sea Level Rise : A Review of the Scientific Evidence

Dasgupta, Susmita; Meisner, Craig
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
EN_US
Relevância na Pesquisa
35.92%
Sea-level rise (SLR) due to climate change is a serious global threat: the scientific evidence is now overwhelming. The rate of global sea level rise was faster from 1993 to 2003, about 3.1 mm per year, as compared to the average rate of 1.8 mm per year from 1961 to 2003 (IPCC, 2007); and significantly higher than the average rate of 0.1 to 0.2 mm/yr increase recorded by geological data over the last 3,000 years. Anthropogenic warming and SLR will continue for centuries due to the time scales associated with climate processes and feedbacks, even if greenhouse gas concentrations were to be stabilized. This paper reviews the scientific literature to date on climate change and sea level rise. There appears to be a consensus across studies that global sea level is projected to rise during the 21st century at a greater rate than during the period 1961 to 2003 and unanimous agreement that SLR will not be geographically uniform. Ocean thermal expansion is projected to contribute significantly, and land ice will increasingly lose mass at an accelerated rate. But most controversial are the mass balance loss estimates of the Greenland and Antarctic Ice Sheets and what the yet un-quantified dynamic processes will imply in terms of SLR. Recent evidence on the vulnerability of Greenland and west Antarctic ice sheets to climate warming raises the alarming possibility of SLR by one meter or more by the end of the 21st century.

Economic Growth, Inequality, and Poverty : Findings from a New Data Set

Adams, Richard H., Jr.
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
EN_US
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The author uses new data from 50 developing countries and 101 intervals to examine the impact of economic growth on poverty and inequality. He finds that growth represents an important means for reducing poverty in the developing world. When economic growth is measured by survey mean income (consumption), there is a strong, statistical link between growth and poverty reduction. When economic growth is measured by GDP per capita, the statistical relationship between growth and poverty reduction is still present, albeit not quite as strong. Economic growth reduces poverty because growth has little impact on income inequality. In the data set income inequality rises on average less than 1.0 percent a year. Since income distributions are relatively stable over time, economic growth tends to raise incomes for all members of society, including the poor. When growth is measured by survey mean income (consumption), the elasticity of poverty with respect to growth is -2.59. In other words, on average, a 10 percentage point increase in economic growth (measured by survey mean income) will produce a 25.9 percent decrease in the proportion of people living in poverty ($1 a person a day).

Aid Is Good for the Poor

Hirano, Yumeka; Otsubo, Shigeru
Fonte: World Bank Group, Washington, DC Publicador: World Bank Group, Washington, DC
EN_US
Relevância na Pesquisa
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Aid is good for the poor. This paper uses detailed aid data spanning 60 developing countries over the past two decades to show that social aid significantly and directly benefits the poorest in society, while economic aid increases the income of the poor through growth. This new and unequivocal finding distinguishes the current study from past studies that only utilized aggregate aid data and returned ambiguous results. The paper also confirms that none of the elements of globalization (trade, foreign direct investment, remittances), policies (government expenditure, inflation management), institutional quality, nor other plausibly pro-poor factors have systematic effects on the poor or any other income group, beyond their effects on average incomes. The paper finds that trade and foreign direct investment tend to benefit the richest segments of society more than other income groups. Therefore, the presented evidence suggests that aid can play a crucial role in enabling the poor to benefit more from globalization. These discoveries underscore the need to assist developing countries to find the mix of economic and social aid that jointly promotes the participation of the poor in the development process under globalization. In this manner...

Interest Rate Caps around the World : Still Popular, but a Blunt Instrument

Maimbo, Samuel Munzele; Henriquez Gallegos, Claudia Alejandra
Fonte: World Bank Group, Washington, DC Publicador: World Bank Group, Washington, DC
EN_US
Relevância na Pesquisa
35.96%
Among other common forms of government financial control, caps on interest rates have been declining over the past several decades as most industrialized countries and a rising number of developing countries continue liberalizing their financial policies. However, in several countries the last financial crisis reopened the debate on interest rate controls as a tool for consumer protection. This paper undertakes a stock-taking exercise to determine the number of countries currently capping interest rates on loans. The paper looks at the main characteristics of the regimes countries have used, including the source of rate-setting authority, the methodology, and the criteria for establishing the cap. The paper finds at least 76 countries around the world currently use some form of interest rate caps on loans -- all with varying degrees of effects, including the withdrawal of financial institutions from the poor or from specific segments of the market, an increase in the total cost of the loan through additional fees and commissions...

Accuracy of Hotel Feasibility Study Projections

Tarras, John M.
Fonte: FIU Digital Commons Publicador: FIU Digital Commons
Tipo: Artigo de Revista Científica Formato: application/pdf
Relevância na Pesquisa
45.73%
Hotel feasibility studies are critical in the determination of hotel construction, sales and refinancing. Discrepancies have been reported between forecasted results and actual operating results. The author, with funding provided by the Hilton corporation, examines whether such studies under- state or overstate occupancy, average rate, and net income.

Improved Method to Select the Lagrange Multiplier for Rate-Distortion Based Motion Estimation in Video Coding

González de Suso, José Luis; Jiménez-Moreno, Amaya; Martínez Enríquez, Eduardo; Díaz-de-María, Fernando
Fonte: IEEE Publicador: IEEE
Tipo: info:eu-repo/semantics/acceptedVersion; info:eu-repo/semantics/article
Publicado em /03/2014 ENG
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45.72%
The motion estimation (ME) process used in the H.264/AVC reference software is based on minimizing a cost function that involves two terms (distortion and rate) that are properly balanced through a Lagrangian parameter, usually denoted as lambda(motion). In this paper we propose an algorithm to improve the conventional way of estimating lambda(motion) and, consequently, the ME process. First, we show that the conventional estimation of lambda(motion) turns out to be significantly less accurate when ME-compromising events, which make the ME process to perform poorly, happen. Second, with the aim of improving the coding efficiency in these cases, an efficient algorithm is proposed that allows the encoder to choose between three different values of lambda(motion) for the Inter 16x16 partition size. To be more precise, for this partition size, the proposed algorithm allows the encoder to additionally test lambda(motion) = 0 and lambda(motion) arbitrarily large, which corresponds to minimum distortion and minimum rate solutions, respectively. By testing these two extreme values, the algorithm avoids making large ME errors. The experimental results on video segments exhibiting this type of ME-compromising events reveal an average rate reduction of 2.20% for the same coding quality with respect to the JM15.1 reference software of H.264/AVC. The algorithm has been also tested in comparison with a state-of-the-art algorithm called context adaptive Lagrange multiplier. Additionally...

Benchmarking Global Poverty Reduction

Ravallion, Martin
Fonte: Banco Mundial Publicador: Banco Mundial
Tipo: Publications & Research :: Policy Research Working Paper; Publications & Research
ENGLISH; EN_US
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35.97%
Against what standards should we judge the developing world's overall performance against poverty going forward? The paper proposes two measures, each with both "optimistic" and "ambitious" targets for 2022, 10 years from the time of writing. The first measure is absolute consumption poverty, as judged by what "poverty" means in the poorest countries. The second is a new measure of global poverty combining absolute poverty with country-specific social inclusion needs, consistently with national poverty lines. The optimistic benchmark would entail an absolute poverty rate of 9 percent in 2022, and a combined poverty rate of 40 percent, including the allowance for social inclusion. The more ambitious targets would bring the absolute rate down to 3 percent and the combined rate to 33 percent. The optimistic target would maintain the (impressive) progress against poverty of the last 20 years, without global crises to stall that progress. The ambitious target would require about a 1 percentage point higher growth rate for the gross domestic product of the developing world...

Shared Prosperity : Links to Growth, Inequality and Inequality of Ppportunity

Narayan, Ambar; Saavedra-Chanduvi, Jaime; Tiwari, Sailesh
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Tipo: Publications & Research :: Policy Research Working Paper; Publications & Research
ENGLISH; EN_US
Relevância na Pesquisa
35.98%
Focusing on the welfare of the less well off as a measure of real societal progress is the fundamental principle underlying the WBG indicator of "shared prosperity", namely income growth of the bottom 40 percent in every country. This paper uses a database assembled by the World Bank Group to investigate some basic characteristics of shared prosperity, particularly its relationship with overall economic growth and inequality. Initial estimates using this dataset of 79 countries show that median income growth of the bottom 40 percent (circa 2005-2010) was 4.2 percent, a high number in comparison to the 3.1 percent per capita income growth of the overall population. In addition, the low and lower-middle income countries appear to be trailing the upper middle and high income countries in boosting shared prosperity. Establishing conceptual links between income growth of the bottom 40 percent, the overall growth rate and reviewing existing evidence on how these relate to inequality, the paper discusses two main ideas. First...

On the average rate of return in a continuous time stochastic model

Gajek, Leslaw; Kaluszka, Marek
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 15/01/2015
Relevância na Pesquisa
45.91%
In a discrete time stochastic model of a pension investment funds market Gajek and Kaluszka(2000a) have provided a definition of the average rate of return which satis?es a set of economic correctnes postulates. In this paper the average rate of return is defined for a continuous time stochastic model of the market. The prices of assets are modeled by the multidimensional geometrical Brownian motion. A martingale property of the average rate of return is proven.; Comment: 12 pages

Utility-Based Wireless Resource Allocation for Variable Rate Transmission

Zhang, Xiaolu; Tao, Meixia; Ng, Chun Sum
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 18/10/2007
Relevância na Pesquisa
36%
For most wireless services with variable rate transmission, both average rate and rate oscillation are important performance metrics. The traditional performance criterion, utility of average transmission rate, boosts the average rate but also results in high rate oscillations. We introduce a utility function of instantaneous transmission rates. It is capable of facilitating the resource allocation with flexible combinations of average rate and rate oscillation. Based on the new utility, we consider the time and power allocation in a time-shared wireless network. Two adaptation policies are developed, namely, time sharing (TS) and joint time sharing and power control (JTPC). An extension to quantized time sharing with limited channel feedback (QTSL) for practical systems is also discussed. Simulation results show that by controlling the concavity of the utility function, a tradeoff between the average rate and rate oscillation can be easily made.; Comment: 6 pages, 5 figures, to appear in IEEE Trans. on Wireless Communications

Estimate the Occurrence Rate of the DNA Palindromes

Tu, I-Ping; Huang, Yuan-Fu; Wang, Shao-Hsuan
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 26/04/2011
Relevância na Pesquisa
35.92%
A DNA palindrome is a segment of double-stranded DNA sequence with inver- sion symmetry which may form secondary structures conferring significant biolog- ical functions ranging from RNA transcription to DNA replication. To test if the clusters of DNA palindromes distribute randomly is an interesting bioinformatic problem, where the occurrence rate of the DNA palindromes is a key estimator for setting up a test. The most commonly used statistics for estimating the occur- rence rate for scan statistics is the average rate. However, in our simulation, the average rate may double the null occurrence rate of DNA palindromes due to hot spot regions of 3000 bp's in a herpes virus genome. Here, we propose a formula to estimate the occurrence rate through an analytic derivation under a Markov assumption on DNA sequence. Our simulation study shows that the performance of this method has improved the accuracy and robustness against hot spots, as compared to the commonly used average rate. In addition, we derived analytical formula for the moment-generating functions of various statistics under a Markov model, enabling further calculations of p-values.; Comment: 16 pages, 1 figure

Average Rate of Downlink Heterogeneous Cellular Networks over Generalized Fading Channels - A Stochastic Geometry Approach

Di Renzo, Marco; Guidotti, Alessandro; Corazza, Giovanni E.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
45.84%
In this paper, we introduce an analytical framework to compute the average rate of downlink heterogeneous cellular networks. The framework leverages recent application of stochastic geometry to other-cell interference modeling and analysis. The heterogeneous cellular network is modeled as the superposition of many tiers of Base Stations (BSs) having different transmit power, density, path-loss exponent, fading parameters and distribution, and unequal biasing for flexible tier association. A long-term averaged maximum biased-received-power tier association is considered. The positions of the BSs in each tier are modeled as points of an independent Poisson Point Process (PPP). Under these assumptions, we introduce a new analytical methodology to evaluate the average rate, which avoids the computation of the Coverage Probability (Pcov) and needs only the Moment Generating Function (MGF) of the aggregate interference at the probe mobile terminal. The distinguishable characteristic of our analytical methodology consists in providing a tractable and numerically efficient framework that is applicable to general fading distributions, including composite fading channels with small- and mid-scale fluctuations. In addition, our method can efficiently handle correlated Log-Normal shadowing with little increase of the computational complexity. The proposed MGF-based approach needs the computation of either a single or a two-fold numerical integral...

Recent and Long-Term Behavior of the Brawley Fault Zone, Imperial Valley, California: An Escalation in Slip Rate?

Meltzner, Aron J.; Rockwell, Thomas K.; Owen, Lewis A.
Fonte: Seismological Society of America Publicador: Seismological Society of America
Tipo: Article; PeerReviewed Formato: application/pdf
Publicado em /12/2006
Relevância na Pesquisa
36.02%
The Brawley fault zone (bfz) and the Brawley Seismic Zone constitute the principal transfer zone accommodating strain between the San Andreas and Imperial faults in southernmost California. The bfz ruptured along with the Imperial fault in the 1940 M_w 6.9 and the 1979 M_w 6.4 earthquakes, although in each case only minor slip apparently occurred on the bfz; several other episodes of slip and creep have been documented on the bfz historically. Until this study, it has been unclear whether the past few decades reflect average behavior of the fault. Two trenches were opened and a series of auger holes were bored across three strands of the bfz at Harris Road to compare the amount of slip observed historically with the displacements observed in the paleoseismic record. Evidence is presented, across the westernmost strand of the bfz and across the entire bfz at Harris Road, to show that both the average vertical slip rate observed in modern times (since 1970) and the vertical creep rate (excluding coseismic slip) observed during the 1970s are significantly higher than the long-term average. Across the westernmost strand, the long- term vertical rate is 1.2 (+1.5/−0.5) mm/yr, and the average rate since about a.d. 1710 is determined to be no greater than 2.0 mm/yr; in contrast...

Essays on Exchange Rate Risk

Rafferty, Barry John
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Dissertação
Publicado em //2012
Relevância na Pesquisa
35.92%

This dissertation is a collection of papers with the unifying objective being to better understand crash risk in foreign exchange markets. I investigate how exposure to the risk of currency crashes is able to provide a unified rationalization of the returns of various sorted currency portfolios.

In the first chapter, I identify an aggregate global currency skewness risk factor, which I denote SKEW. Currency portfolios that have higher average excess returns covary more positively with this risk factor. They suffer losses in times when high interest rate investment currencies have a greater tendency to depreciate sharply as a group relative to low interest rate funding currencies. Consequently, they earn higher average excess returns as reward for exposure to this risk. I create three sets of sorted currency portfolios reflecting three distinct sources of variation in average excess currency returns. The first set sorts currencies based on interest rate differentials. The second set sorts currencies based on currency momentum. The third set sorts currencies based on currency undervaluedness relative to purchasing power power parity (PPP) implied exchange rates. I find that differences in exposure to the global currency skewness risk factor can explain the systematic variation in average excess currency returns within all three groups of portfolios much better than existing foreign exchange risk factors in the literature.

In the second chapter...