Miracle-dz/UniFAR-FTUs huggingface dataset:
Portfolio selection with commodities under conditional asymmetric dependence and skew preferences ∗

This article solves the portfolio selection problem for an investor with three-moment preferences, when returns follow a conditional asymmetric t copula with skewed and fat-tailed marginal distributions. The model can capture the impact on optimal portfolios of: time-varying investment opportunities, state dependence in the returns’ correlations, and tail dependence. In the empirical test with oil and gold futures and equity from 1990 to 2010, the portfolios achieve better performance measures than they would under conventional alternatives. The factors explaining the significant differences among methods are the univariate process specification, the dynamic dependence, and the presence of tail and asymmetric dependence.
Aldehyde Measurements in Indoor and Outdoor Environments in Central-Southern Spain

Aldehydes are indoor and outdoor chemical pollutants of particular interest due to their potential adverse health effects on humans and to their important role in atmospheric chemistry. In fact, carbonyls are of critical importance since they are the most stable inter‐ mediate species in the oxidation of volatile organic compounds. Even in the indoor environ‐ ments, aldehydes can be released from ozone reactions with unsaturated VOCs [1]. The most important global source of formaldehyde and acetaldehyde in the atmosphere is of secondary origin, and it is the oxidation of natural and anthropogenic hydrocarbons. However, motor vehicle exhausts represent the primary emission source of these pollutants in urban areas [2].
Monetary Transmission Mechanism in Nigeria: A Causality Test

For decades the major focus of the Central Bank of Nigeria (CBN) has been the formulation and implementation of monetary policies on how to achieve the macroeconomic goals of low inflation, interest rate and exchange rate regulation, and sustained economic growth. But the real sector of the Nigerian economy has performed poorly in terms of sustainable economic growth, low inflation and stable interest and exchange rates. This has resulted in a erratically stable economy; monetary policy-shocks debarred sectors and highly vulnerable macroeconomic aggregates. This study examines the channels of monetary transmission mechanism in Nigeria. The main objective of the study is to identify and validate the existence of some channels of monetary transmission mechanism in the Nigerian context. The study reviewed both the theoretical, empirical and methodological literatures. The Granger causality test was adopted in the estimation of the relationship between the various channels and selected macroeconomic aggregates. Based on the results of our analysis, the study concludes that three channels are functional in Nigeria-the interest rate, exchange rate and the credit channels. We recommend that the exchange rate and interest rate channels should form a fundamental basis for inflation targeting in Nigeria. DOI: 10.5901/mjss.2013. v4n13p377
Lifetimes for Radiative Charge Recombination in Donor-Acceptor Molecules

In this paper we demonstrate that the marked solvent dependence of the rates kmd for radiative recombination in some donor (D)-bridge (B)-acceptor (A) molecules, which increase with decreasing solvent polarity (i.e., with increasing peak energy ( v ) for charge-transfer fluorescence), can be quantitatively accounted for in terms of a dominating contribution of (DBA)*-D+BAmixing, involving intensity borrowing from local (DBA)* electronic excitations. In these DBA molecules, the traditional two-level D+BA--DBA coupling scheme is inapplicable. The analysis of the ( v ) dependence of krad for a certain DBA in a series of solvents results in the (DBA)*-D+BAcouplings V , which are in good agreement with the V parameters extracted from oscillator strengths for charge-transfer absorption. The V parameters, which obey the relation V' 0: exp(-aN) (where N is the number of bonds in the bridge), determine the rates for nonradiative (DBA)* D+BAcharge separation and recombination from electronically excited states. The (DBA) *-D+BAmixing is maximized for the isolated, solvent-free DBA molecule. For the isolated molecules analyzed herein, the fraction of (DBA)* admixture within the charge-transfer state is -0.02, being even smaller for the solvated molecules.
Effects of pool formation and flash flooding on relative abundance of young-of-year flannelmouth suckers in the Paria River, Arizona

Flannelmouth sucker, Catostomus latipinnis, a fish endemic to the Colorado River basin in the western United States, appears to experience poor recruitment to adult size in the Colorado River, downstream of Glen Canyon Dam. Lack or impermanence of rearing areas for young-of-year (YOY) fish is hypothesized to be the problem. Knowing the importance of tributary mouths as rearing areas in other river systems, we studied use of the mouth of the Paria River, a tributary of the Colorado River, by YOY flannelmouth suckers, and the availability of rearing area in the mouth at different flow levels in the Colorado River in 1996 and 1997. We also examined the relationship between flash floods in the Paria River and catch-per-unit-effort (CPUE) of YOY in the Paria River between 1991 and 1996. Maximum mean daily discharge in the Paria River was inversely correlated with CPUE of YOY flannelmouth suckers (Spearman Rho=−0.9856, p=0.0003) during their critical rearing period (15 March–30 June). Thus, it appears that YOY flannelmouth suckers rear longer in the Paria River in years when flash flooding is minimal. Recruitment of YOY flannelmouth suckers at the Paria River may also be improved by enhancing pool formation during spring and summer rearing seasons. YOY flannelmouth sucker was captured in a pool created by high Colorado River flows (≥336 m3/s) that inundated the mouth of the Paria River during spring and summer, 1996. In 1997, high flows (about 550–750 m3/s) in the Colorado River during winter and spring initially inundated the Paria River and formed a pool in the mouth. However, these high flows eventually caused 0.5–1.0 m of suspended sediment from the incoming Paria River to deposit in the mouth. Thus, despite higher flows than 1996, the slackwater area formed only occasionally in 1997. Differences in pool formation between 1996 and 1997 demonstrate that pool formation cannot be inferred solely from Colorado River flows. Copyright © 2001 John Wiley & Sons, Ltd.
Inflammation-associated risk factors for Alzheimer s disease and dementia

Inflammation-Associated Risk Factors for Alzheimer’s Disease and Dementia Ulrika K. Eriksson has a Master in Medical Science with a Major in Biomedicine from the Karolinska Institutet, Stockholm, Sweden. Her doctoral thesis consists of epidemiological studies of inflammation‐associated risk factors for Alzheimer’s disease and dementia using data from the Swedish Twin registry.
Assessment of Atmospheric and Meteorological Parameters for Control of Blasting Dust at an Indian Large Surface Coal Mine

The aim of the study was to assess the atmospheric and meteorological parameters for the control of blasting dust. Dust generated due to blasting at large surface coal mines causes air pollution in and around the mining area. The dispersion of blasting dust depends on prevailing atmospheric and meteorological conditions. A Sound Detection and Ranging (SODAR) was installed at the mine site to monitor atmospheric conditions in four seasons. Over 2000 sodar echograms were examined and classified into six categories as rising layers, thermal plume (free), ground based layer (spiky top), spiky top layer (clear weather), flat top layer (calm cold), and ground based stratified and multiple layers. Dot echo structures in the echograms were also observed during rainfall. From sodar echograms, unstable and stable periods were identified. Pasquill stability classes were evaluated by echograms and mixing heights. An automatic weather station was also installed at the site to monitor meteorological parameters as wind speed, wind direction, temperature, humidity, solar radiation and rainfall. Simple correlations as well as multiple regression analysis of meteorological parameters with mixing height show that solar radiation has strong influence on mixing height. The nearby villages that are likely to be affected by blasting dust can be protected by planting trees perpendicular to the wind direction as indicated by windrose diagrams. Dispersion factors, the product of mixing height and wind speed, were calculated for all the seasons. It was suggested that blasting should be conducted during the period when the dispersion factor is maximum so that the impacts of blasting dust on the environment can be minimised.
Assimilation of Synthetic SWOT River Depths in a Regional Hydrometeorological Model

The SWOT (Surface Water and Ocean Topography) mission, to be launched in 2021, will provide water surface elevations, slopes, and river width measurements for rivers wider than 100 m. In this study, synthetic SWOT data are assimilated in a regional hydrometeorological model in order to improve the dynamics of continental waters over the Garonne catchment, one of the major French catchments. The aim of this paper is to demonstrate that the sequential assimilation of SWOT-like river depths allows the correction of river bed roughness coefficients and thus simulated river depths. An extended Kalman filter is implemented and the data assimilation strategy was applied to four experiments of gradually increasing complexity regarding observation and model error over the 1995–2000 period. With respect to a “true” river state, assimilating river depths allows the proper retrieval of constant and spatially distributed roughness coefficients with a root mean square error of 1 m1/3 s−1, and the estimation of associated river depths. It was also shown that river depth differences can be assimilated, resulting in a higher root mean square error for roughness coefficients with respect to the true river state. Finally, the last experiment shows how one can take into account more realistic sources of SWOT error measurements, in particular the importance of the estimation of the tropospheric water content in the process.
0−π quantum transition in a carbon nanotube Josephson junction: Universal phase dependence and orbital degeneracy

Abstract In a quantum dot hybrid superconducting junction, the behavior of the supercurrent is dominated by Coulomb blockade physics, which determines the magnetic state of the dot. In particular, in a single level quantum dot singly occupied, the sign of the supercurrent can be reversed, giving rise to a π -junction. This 0 − π transition, corresponding to a singlet-doublet transition, is then driven by the gate voltage or by the superconducting phase in the case of strong competition between the superconducting proximity effect and Kondo correlations. In a two-level quantum dot, such as a clean carbon nanotube, 0– π transitions exist as well but, because more cotunneling processes are allowed, are not necessarily associated to a magnetic state transition of the dot. In this proceeding, after a review of 0– π transitions in Josephson junctions, we present measurements of current-phase relation in a clean carbon nanotube quantum dot, in the single and two-level regimes. In the single level regime, close to orbital degeneracy and in a regime of strong competition between local electronic correlations and superconducting proximity effect, we find that the phase diagram of the phase-dependent transition is a universal characteristic of a discontinuous level-crossing quantum transition at zero temperature. In the case where the two levels are involved, the nanotube Josephson current exhibits a continuous 0 − π transition, independent of the superconducting phase, revealing a different physical mechanism of the transition.
Numerical simulation of BSDEs with drivers of quadratic growth

This article deals with the numerical resolution of Markovian backward stochastic differential equations (BSDEs) with drivers of quadratic growth with respect to $z$ and bounded terminal conditions. We first show some bound estimates on the process $Z$ and we specify the Zhang's path regularity theorem. Then we give a new time discretization scheme with a non uniform time net for such BSDEs and we obtain an explicit convergence rate for this scheme.
Evaluating sulfur dynamics during storm events for three watersheds in the northeastern USA: a combined hydrological, chemical and isotopic approach

Concerns related to climate change have resulted in an increasing interest in the importance of hydrological events such as droughts in affecting biogeochemical responses of watersheds. The effects of an unusually dry summer in 2002 had a marked impact on the biogeochemistry of three watersheds in the north‐eastern USA. Chemical, isotopic and hydrological responses with particular emphasis on S dynamics were evaluated for Archer Creek (New York), Sleepers River (Vermont) and Cone Pond (New Hampshire) watersheds. From 1 August to 14 September 2002, all three watersheds had very low precipitation (48 to 69 mm) resulting in either very low or no discharge (mean 0·015, 0·15 and 0·000 mm day−1 for Archer Creek, Sleepers River and Cone Pond, respectively). From 15 September to 31 October 2002, there was a substantial increase in precipitation totals (212, 246 and 198 mm, respectively) with increased discharge. Archer Creek was characterized by a large range of SO42− concentrations (152 to 389 µeq L−1, mean = 273 µeq L−1) and also exhibited the greatest range in δ34S values of SO42− (−1·4 to 8·8 ‰ ). Sleepers River's SO42− concentrations ranged from 136 to 243 µeq L−1 (mean = 167 µeq L−1) and δ34S values of SO42− ranged from 4·0 to 9·0 ‰ . Cone Pond's SO42− concentrations (126–187 µeq L−1, mean = 154 µeq L−1) and δ34S values (2·4 to 4·3 ‰ ) had the smallest ranges of the three watersheds. The range and mean of δ18O‐SO42− values for Archer Creek and Cone Pond were similar (3·0 to 8·9 ‰ , mean = 4·5 ‰ ; 3·9 to 6·3 ‰ , mean = 4·9 ‰ ; respectively) while δ18O‐SO42− values for Sleepers River covered a larger range with a lower mean (1·2 to 10·0 ‰ , mean = 2·5). The difference in Sleepers River chemical and isotopic responses was attributed to weathering reactions contributing SO42−. For Archer Creek wetland areas containing previously reduced S compounds that were reoxidized to SO42− probably provided a substantial source of S. Cone Pond had limited internal S sources and less chemical or isotopic response to storms. Differences among the three watersheds in S biogeochemical responses during these storm events were attributed to differences in S mineral weathering contributions, hydrological pathways and landscape features. Further evaluations of differences and similarities in biogeochemical and hydrological responses among watersheds are needed to predict the impacts of climate change. Copyright © 2008 John Wiley & Sons, Ltd.
Photocatalysis on TiO2 Surfaces: Principles, Mechanisms, and Selected Results

In 1972, Fujishima and Honda discovered the photocatalytic splitting of water on TiO{sub 2} electrodes. This event marked the beginning of a new era in heterogeneous photocatalysis. Since then, research efforts in understanding the fundamental processes and in enhancing the photocatalytic efficiency of TiO{sub 2} have come from extensive research performed by chemists, physicists, and chemical engineers. Such studies are often related to energy renewal and energy storage. In recent years, applications to environmental cleanup have been one of the most active areas in heterogeneous photocatalysis. This is inspired by the potential application of TiO{sub 2}-based photocatalysts for the total destruction of organic compounds in polluted air and wastewaters. There exists a vast body of literature dealing with the electron transfer and energy transfer processes in photocatalytic reactions. A detailed description of these processes is beyond the scope of this review. Here, the authors tend to focus on interfacial processes and to summarize some of the operating principles of heterogeneous photocatalysis. In section 2, the authors first look at the electronic excitation processes in a molecule and in a semiconductor substrate. The electronic interaction between the adsorbate molecule and the catalyst substrate is discussed in terms of the catalyzed ormore » sensitized photoreactions. In section 3, thermal and photocatalytic studies on TiO{sub 2} are summarized with emphasis on the common characteristics and fundamental principles of the TiO{sub 2}-based photocatalysis systems. In section 4, they address the research effort in the electronic modification of the semiconductor catalysts and its effect on the photocatalytic efficiency. Several representative examples will be presented including the Schottky barrier formation and modification at metal-semiconductor interfaces. Some concluding remarks and future research directions will be given in the final section. 160 refs.« less
What Type of Feedback Do Student Teachers Expect from Their School Mentors during Practicum Experience? The Case of Spanish EFL Student Teachers.

Mentorship represents a vital component in all teacher education programmes since mentors’ feedback plays an essential role in shaping candidate teachers’ professional identity. The quality of feedback provided by school mentors during the practicum experience constitutes the main focus of this study. This research paper aimed at investigating Spanish EFL student teachers’ needs and expectations from their school mentors’ feedback in the practicum setting, drawing particular attention to what areas or aspects related to mentor feedback needed improvement. Both quantitative and qualitative research methodologies were used in the study. The resulting data revealed a high degree of satisfaction among the surveyed student teachers concerning the quality of mentor feedback, meeting their needs and expectations in a very substantial manner. Specifically, the main strength of mentors’ feedback lies in its supportive and affective nature while the main weakness highlighted was the need for a more detailed and continued input or feedback from school mentors. Thus, this research paper highlights the gap between the quality of feedback provided by school mentors and mentees’ expectations and satisfactions during their professional school experiences.
Effect of Operating Parameters on Extraction of Oil from Bitter Gourd Seeds: A Kinetic and Thermodynamic Study

Bitter gourd (Momordicacharantia) is a very nutritious vegetable having high therapeutic value due to the presence of αEleostearic acid and exhibits anti carcinogenic properties. Present study involves extraction of oil from bitter gourd seeds using soxhlet apparatus with n-hexane as a solvent. The effect of extraction time, volume of solvent and particle size of bitter guard on oil yield was estimated and observed that, the oil yield has increased with increase in time and volume of solvent but decreased with increase in particle size. It was also observed that, a maximum oil yield of 51% was obtained at 100oC for an extraction time of 150 minutes using 15g of dried Bitter Gourd seed and 50 ml of n-hexane. Apart from these, the kinetics and thermodynamics of oil extraction from bitter gourd seeds was also studied. The kinetic studies have shown that the extraction process has fourth order kinetics and the thermodynamic studies reveal that the process is endothermic and requires energy.
Measuring the Thickness of the Liquid-like Layer on Ice Surfaces with Atomic Force Microscopy

Atomic force microscopy was used to study the surface melting of ice in a temperature range above −35 °C. The thickness of the liquid-like layer (d) on ice was determined from the jump-in distance of force-versus-distance curves. The layer thickness of ice formed from distilled water was roughly 32 nm at −1 °C and 11 nm at −10 °C. The temperature dependence of d could best be described by d ∝ −log ΔT, where ΔT is the difference between the melting temperature and the actual temperature. The addition of salt increased the thickness of the liquid-like layer, and the temperature dependency agreed with predictions by Wettlaufer (Phys. Rev. Lett. 1999, 82, 2516).
The base rate fallacy reconsidered: Descriptive, normative, and methodological challenges

Abstract We have been oversold on the base rate fallacy in probabilistic judgment from an empirical, normative, and methodological standpoint. At the empirical level, a thorough examination of the base rate literature (including the famous lawyer–engineer problem) does not support the conventional wisdom that people routinely ignore base rates. Quite the contrary, the literature shows that base rates are almost always used and that their degree of use depends on task structure and representation. Specifically, base rates play a relatively larger role in tasks where base rates are implicitly learned or can be represented in frequentist terms. Base rates are also used more when they are reliable and relatively more diagnostic than available individuating information. At the normative level, the base rate fallacy should be rejected because few tasks map unambiguously into the narrow framework that is held up as the standard of good decision making. Mechanical applications of Bayes's theorem to identify performance errors are inappropriate when (1) key assumptions of the model are either unchecked or grossly violated, and (2) no attempt is made to identify the decision maker's goals, values, and task assumptions. Methodologically, the current approach is criticized for its failure to consider how the ambiguous, unreliable, and unstable base rates of the real world are and should be used. Where decision makers' assumptions and goals vary, and where performance criteria are complex, the traditional Bayesian standard is insufficient. Even where predictive accuracy is the goal in commonly defined problems, there may be situations (e.g., informationally redundant environments) in which base rates can be ignored with impunity. A more ecologically valid research program is called for. This program should emphasize the development of prescriptive theory in rich, realistic decision environments.
Why Is Cash (Still) So Entrenched? Insights from the Bank of Canada’s 2009 Methods-of-Payment Survey

The authors present key insights from the Bank of Canada’s 2009 Methods-of-Payment survey. In the survey, about 6,800 participants completed a questionnaire with detailed information regarding their personal finances, as well as their use and perceptions of different payment methods. In addition, about 3,500 participants completed a 3-day diary recording information on each transaction, including the value and the payment instrument chosen. One of the main findings from the diaries is that, even though debit and credit cards account for close to 80 per cent of all transactions in terms of total value, cash is still the predominant payment method in terms of volume, accounting for 54 per cent of all transactions. Using the payment records from the diaries, the authors estimate a simple model of choice between cash and other payment methods. The results suggest that the main reasons why cash is still a popular payment instrument in Canada, especially for small-value transactions, are its wide acceptance among merchants, high ease of use or speed, low handling costs, simplicity as a tool to control spending, and anonymity.