Miracle-dz/UniFAR-FTUs huggingface dataset:
The Art of Heart Rate Variability

A substantial percentage of accidents are caused by drivers falling asleep at wheel. Among the different ways of detecting sleepiness at wheel, physiological measurements start changing at an earlier stage of fatigue what is crucial for accident avoidance. This motivated to study how heart rate and its variability (HRV) relate to drivers sleepiness. The study was conducted on a population of around 80 drivers that drove 3 times (morning, afternoon, night) for about 90 minutes, with subjective sleepiness evaluations every 5 minutes, leading to over 3500 epochs to analyse. In order to derive HRV indices, outlier detection and spectral transformation need to be applied to the data. Different technics are available for these purposes with no consensus about their suitability. In this thesis, the most relevant HRV indices were derived using the main technics for outliers detection and spectral transformation. Two methods were used for outliers detection, one based on a heart beat interval differing in more than 30% the average of the 4 beats before and the other consisting in an interval deviating 5 std from mean. Regarding spectral transformation, DFT, AR-model and LS Periodogram were considered. The agreement between methods was evaluated using Bland-Altman plots and Student T-Tests. The number of samples classified as outliers and removed is, in average, 0.278% for the percentage methods and 0.0648% for the standard deviation method. Outlier detection methods showed to have a low influence on the value of the HRV indices calculated. Spectral transformation methods showed, instead, to have much higher consequences on the HRV indices. The outlier detection method does not have an influence on the capability of different HRV indices of discriminating between morning, afternoon and night. The spectral transformation method does not show a significant influence either. However LS-periodogram performed slightly worst in this regards.
Foreign Aid, Foreign Direct Investment and Economic Growth in Sub-Saharan Africa: Evidence from Pooled Mean Group Estimator (PMG)

In this paper we investigate the long-run relationship between foreign aid, foreign direct investment and economic growth in 36 Sub-Saharan Africa countries over the period 1980-2007. Following the recent dynamic panel data of mean group (MG), pooled mean group estimator (PMG), and dynamic fixed effect (DFE) proposed by Pesaran et al. (1999), we found strong evidence of a positive impact of foreign aid and foreign direct investment on economic growth. However, the effect of foreign aid on growth in SSA is low. For example, an increase in 1% of foreign aid induces only an increase in 0.05% of economic growth for PMG and 0.13% for DFE, while it’s ten times greater for an increase of employment in PMG and approximately six times greater in DFE. Thus, as implication of policy growth, it’s much better to focus on internal factors than external factors to boost economic growth in SSA.
Temperature structures in Galactic Center clouds - Direct evidence for gas heating via turbulence

The Central Molecular Zone (CMZ) at the center of our Galaxy is the best template to study star formation processes under extreme conditions, similar to those in high-redshift galaxies. We observed on-the-fly maps of para-H$_{2}$CO transitions at 218 GHz and 291 GHz towards seven Galactic Center clouds. From the temperature-sensitive integrated intensity line ratios of H$_{2}$CO(3$_{2,1}-$2$_{2,0}$)/H$_{2}$CO(3$_{0,3}-$2$_{0,2}$) and H$_{2}$CO(4$_{2,2}-$3$_{2,1}$)/H$_{2}$CO(4$_{0,4}-$3$_{0,3}$) in combination with radiative transfer models, we produce gas temperature maps of our targets. These transitions are sensitive to gas with densities of $\sim$10$^{5}$ cm$^{-3}$ and temperatures 40 K) than their dust temperatures ($\sim$25 K). Our targets have a complex velocity structure that requires a careful disentanglement of the different components. We produce temperature maps for each of the velocity components and show that the temperatures of the components differ, revealing temperature gradients in the clouds. Combining the temperature measurements with the integrated intensity line ratio of H$_{2}$CO(4$_{0,4}-$3$_{0,3}$)/H$_{2}$CO(3$_{0,3}-$2$_{0,2}$), we constrain the density of this warm gas to 10$^{4}-$10$^{6}$ cm$^{-3}$. We find a positive correlation of the line width of the main H$_{2}$CO lines with the temperature of the gas, direct evidence for gas heating via turbulence. Our data is consistent with a turbulence heating model with a density of n = 10$^5$ cm$^{-3}$.
Groups Acting Freely on Calabi-Yau Threefolds Embedded in a Product of del Pezzo Surfaces

In this paper, we investigate quotients of Calabi-Yau manifolds Y embedded in Fano varieties X which are products of two del Pezzo surfaces - with respect to groups G that act freely on Y. In particular, we revisit some known examples and we obtain some new Calabi-Yau varieties with small Hodge numbers. The groups G are subgroups of the automorphism group of X, which is described in terms of the automorphism group of the two del Pezzo surfaces.
Reciprocal Teaching, Metacognitive Awareness, and Academic Performance in Taiwanese Junior College Students

This study was conducted to discover the effects of reciprocal teaching (RT) on metacognitive awareness and reading comprehension in junior college students. The Metacognitive Awareness Inventory (MAI) was used to identify metacognitive awareness, and the General English Proficiency Test (GEPT) was used to evaluate reading comprehension. Two reading courses with 77 students taught using RT were treated as the experimental group, and 30 students from a non-RT reading course constituted the control group. The results showed statistically significant differences in MAI scores (conditional knowledge and debugging strategy) and reading comprehension between the 2 groups. Although RT had a significant impact on only 2 out of 8 MAI scales, the experimental group had higher overall mean scores on the 8 MAI components than the control group. However, unlike RT, the MAI failed to have a statistically significant impact on enhancing students? reading scores. Thus, metacognitive awareness might affect text comprehension, but metacognitive awareness did not influence the levels of reading comprehension students achieved in this study.
Methods to Estimate Above-Ground Biomass and Carbon Stock in Natural Forests - A Review

Carbon exists as carbon dioxide in the atmosphere and constitutes about 0.04% of the atmosphere. In the recent past, it has gained a lot of attention as a greenhouse gas, as it has potential to influence the climate pattern of the world. Anthropogenic activities like industrialisation, deforestation, forest degradation and burning of fossil fuel, has caused an increase in the level of carbon in the atmosphere and disrupted the global carbon cycle. However, nature has its own mechanism of sequestering and storing the carbon in its “reservoirs” or “sinks’’. Forest plays an important role in the global carbon cycle as carbon sinks of the terrestrial ecosystem. The carbon sequestered or stored on the forest trees are mostly referred to as the biomass of the tree or forest. The Intergovernmental Panel on Climate Change identified five carbon pools of the terrestrial ecosystem involving biomass, namely the aboveground biomass, below-ground biomass, litter, woody debris and soil organic matter. Among all the carbon pools, the above-ground biomass constitutes the major portion of the carbon pool. Estimating the amount of forest biomass is very crucial for monitoring and estimating the amount of carbon that is lost or emitted during deforestation, and it will also give us an idea of the forest’s potential to sequester and store carbon in the forest ecosystem. Estimations of forest carbon stocks are based upon the estimation of forest biomass. Forest’s carbon stocks are generally not measured directly; however, many authors assume the carbon concentration of tree parts to be 50% or 45% of the dry biomass. This paper, aims to review and summarise the various methods and studies that were carried out to estimate the above-ground biomass of the forest.
Community structure of benthic macroinvertebrates inhabiting a highly stratified Mediterranean estuary

SUMMARY: The community composition and spatial distribution of benthic macroinvertebrates were studied along the Ebro estuary, a highly stratified estuary located in the NE Iberian Peninsula. During the last decade the oligotrophication process occurring in the lower Ebro River and its estuary has allowed a complex benthic macroinvertebrate community to become established; these results contrast with the poor community found there in the early nineties. A total of 214 taxa were identified, and polychaetes dominated the community both in abundance and species richness. The results showed spatial differences in the structure and composition of macroinvertebrates, which suggests that there are two distinct communities along the estuary. Each community was found in a specific stretch (upper and lower estuary) in function of the presence of the salt wedge. The macrobenthos of the upper estuary was dominated by freshwater taxa, but some euryhaline species were also found. The lower estuary showed a marine community typical of shallow Mediterranean environments. The transition between these two communities fits an ecotone model. The highest abundances, richness and diversities were recorded at the lower estuarine stations, especially those closer to the river mouth, whereas the lowest values corresponded to the stations adjacent to the tip of the salt wedge.
Malondialdehyde level and some enzymatic activities in subclinical mastitis milk

The purpose of this study was to evaluate the changes occurring in milk malondialdehyde (MDA) level and some enzymatic activities as a result of subclinical mastitis (SCM) in dairy cows. A total of 124 milk samples were collected from 124 lactating cows from the same herd in the period between the 2nd week after calving and the 10th week postpartum. They were classified by bacterial culture and the California mastitis test (CMT) as positive were deemed to have glands with SCM, and the periodic incidence rate of SCM was 26.6%. The most common bacterial isolates from SCM cases were Staphylococcus aureus (47%) and coagulase negative Staphylococci (CNS) (27%). The mean level of MDA and activities of lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) were significantly higher in SCM milk than in normal milk, while the mean activity of glutathione peroxidase (GPx) was significantly lower in SCM milk than in normal milk. There were no differences in the activities of superoxide dismutase (SOD) and aspartate aminotransferase (AST) between normal milk and SCM milk. Therefore, the measurement of milk MDA level and GPx, LDH and ALP activities, appears to be a suitable diagnostic method for identifying SCM in dairy cows.
The role of intratidal oscillations in sediment resuspension in a diurnal, partially mixed estuary

[1] Using detailed observations of the mean and turbulent properties of flow, salinity and turbidity that spanned 2001/02, we examined the physical mechanisms underpinning sediment resuspension in the low-energy Swan River estuary, Western Australia. In this diurnal tidally-dominated estuary, the presence of intratidal oscillations, a tidal inequality lasting 2 to 3 hours on the flood tide, generated by interactions of the four main diurnal and semidiurnal astronomical constituents, K1, O1, M2, and S2, played a major role in modifying vertical stratification and mixing. These intratidal oscillations are controlled by phase differences between the tropic and synodic months rather than being temporally-fixed by bed friction, as occurs in semidiurnal estuaries. Intratidal oscillations are largest, at around 0.1 m, near to the Austral solstice when the lunar and solar declination are in-phase. Despite the seemingly small change in water level, shear-induced interfacial mixing caused destratification of the water column with the top-to-bottom salinity (ΔS) difference of 3.5 present early in the flood tide eroded to less than 0.3 by the end of the intratidal oscillation. High turbidity peaks, of 250 nephelometric turbidity units, coincided with these intratidal oscillations and could not be explained by bed friction since shear stress from mean flow did not exceed threshold criteria. High Reynolds stresses of ∼1 Nm−2 did, however, exceed τcr and together with negative Reynolds fluxes indicate a net downward transport of material. Destratification of the water column induced by shear instabilities resulted in large overturns capable of moving in situ material towards the bed during intratidal oscillations and these turbidities were ∼10 times greater than those from bed-generated resuspension observed later during the flood tide.
H.E.S.S. discovery of VHE γ-rays from the quasar PKS 1510−089

The quasar PKS 1510−089 (z = 0.361) was observed with the H.E. S.S. array of imaging atmospheric Cherenkov telescopes during high states in the optical and GeV bands, to search for very high energy (VHE, defined as E ≥ 0.1 TeV) emission. VHE γ-rays were detected with a statistical significance of 9.2 standard deviations in 15.8 h of H.E. S.S. data taken during March and April 2009. A VHE integral flux of I(0.15 TeV < E < 1. 0T eV)= (1.0 ± 0.2stat ± 0.2sys) × 10 −11 cm −2 s −1 is measured. The best-fit power law to the VHE data has a photon index of Γ= 5.4 ± 0.7stat ± 0.3sys. The GeV and optical light curves show pronounced variability during the period of H.E. S.S. observations. However, there is insufficient evidence to claim statistically significant variability in the VHE data. Because of its relatively high redshift, the VHE flux from PKS 1510−089 should suffer considerable attenuation in the intergalactic space due to the extragalactic background light (EBL). Hence, the measured γ-ray spectrum is used to derive upper limits on the opacity due to EBL, which are found to be comparable with the previously derived limits from relatively-nearby BL Lac objects. Unlike typical VHE-detected blazars where the broadband spectrum is dominated by nonthermal radiation at all wavelengths, the quasar PKS 1510−089 has a bright thermal component in the optical to UV frequency band. Among all VHE detected blazars, PKS 1510−089 has the most luminous broad line region. The detection of VHE emission from this quasar indicates a low level of γ − γ absorption on the internal optical to UV photon field.
The Relative Profitability of Analysts’ Stock Recommendations: What Role Does Investor Sentiment Play?

This study investigates whether analysts who respond to investor sentiment issue more or less profitable stock recommendations than their peers. We find that analysts, on average, issue more favorable stock recommendations when investor sentiment is more bullish. However, analysts whose stock recommendations are positively correlated with recent or future investor sentiment tend to issue less profitable recommendations than other analysts who follow the same firm and may focus solely on fundamentals such as earnings, cash flows, and discount rates. Our results suggest that some analysts recommend stocks based, in part, on signals that may affect price but that are not theoretically related to firms’ underlying intrinsic value. Thus, our results may help explain the findings of prior studies which document the failure of some analysts to fully incorporate their earnings forecasts into their stock recommendations. We thank Larry Brown, Yonca Ertimur, Ross Jennings, Kevin Kobelsky, Bill Mayew, Philip Shane, Senyo Tse, Jenny Tucker, Richard Willis, Yong Yu, workshop participants at Baylor University and Purdue University, and conference participants at the 2009 American Accounting Association annual meeting for helpful comments.
Occupation times of refracted L evy processes with jumps having rational Laplace transform

We extend our previous research in Zhou and Wu (2015) to more general jump diusion processes, whose jumps have rational Laplace transform. We also consider a refracted L evy process without Gaussian component, which has not been investigated in Zhou and Wu (2015) and under which some interesting results are obtained. We remark that this extension is non-trivial. Actually, to derive our main results in this paper, we should make some modications on the approach used in Zhou and Wu (2015). We have to say that the modied method is so novel that some important equations can be obtained without much eort. In addition to deriving formulas that can be used to compute the expectation of the total time of deducting fees as in Zhou and Wu (2015), we also obtain a very interesting identity. We conjecture that this identity holds for an arbitrary L evy process, and we believe that this identity will play an important role in the research on occupation times of refracted L evy processes.
Trends in the extreme daily rainfall amount and the frequency of rainy days in Sokoto, Sudano-Sahelian ecological zone of Nigeria

The study examined the trends in both the frequency and magnitude of extreme daily rainfall amount and the frequency of rainy days in Sokoto, Sudano-Sahelian ecological zone of Nigeria between 1951 and 2010. Its specific objectives include: determining the trends in the frequencies of the light and heavy daily rainfall, largest daily annual rainfall magnitude, rainy days and total annual rainfall in Sokoto over time; examining the relationship between the frequencies of the light and heavy daily rainfall, largest daily annual rainfall magnitude and rainy days and total annual rainfall in the study area; and comparing the intra-annual rainfall distribution of 2010 with that of a long time mean over Sokoto. Results indicated that between1951and 1984 the total annual rainfall, frequency of heavy rainfall and rainy days experienced significant declining trends but thereafter, all the parameters except the frequency of heavy daily rainfall, experienced statistically significant upward trends. In aggregate (1951-2010) it resulted into a statistically significant declining trend for the frequencies of the heavy daily rainfall but an increase for the light rainfall and stationary time series of other rainfall parameters between 1951and 2010. There is significant positive relationship between the frequency of heavy daily rainfall, largest daily annual rainfall magnitude and rainy days, and the total annual rainfall in Sokoto, with the heavy daily rainfall contributing most to the inter-annual variability in the total annual rainfall. The results also show that the rainfall of all the months of the rainy season are higher in 2010 than the 1951-2009 average except September which was even slightly lower. The increase in the annual total was overwhelmingly contributed to by the rainfall of the months of July and August. The total annual rainfall recorded in 2010 is unprecedented since 1951. This is a major factor of the flooding reported over the region in 2010. As global warming intensifies therefore, it is anticipated that the hydrological cycle does the same and consequently increases the frequencies as well as the magnitudes of the various rainfall parameters investigated. The Sokoto region should therefore prepare for a wetter condition rather than a drier one.
The Frequency and Significance of Iron-Deficiency Anemia in Patients with Selected Concurrent Illness

Approximately 30% of the world’s population is anemic, of which 50% is iron deficiency anemia (IDA). The extent to which IDA affects patients with concomitant illness has not been described.A systematic review was conducted on the prevalence of IDA and its relationship to clinical outcomes in selected concurrent illness. After pooling the results of eligible studies, we found considerable disparities in the prevalence for IDA, which varied by the diagnostic tools employed. When bone marrow aspirates were used, the prevalence of IDA was: 52% for rheumatoid arthritis, 53% for inflammatory bowel disease, 54% for HIV, and 73% for heart failure. However, when serum ferritin was used, the estimates were: 39%, 22%, 38%, and 32%, respectively. Decreased survival and peak VO2 were also reported in heart failure patients with IDA.IDA is prevalent in concomitant illness and can be underestimated. It may also be an important indicator of adverse prognosis.
Modelling Non-coaxiality and Strain Localisation in Sand: the Role of Fabric and Its Evolution

We present a critical state sand plasticity model accounting for the effect of fabric and its evolution, and apply it to modelling the non-coaxial behaviour and shear localisation phenomenon in sand. The model is developed within the framework of Anisotropic Critical State Theory. A novel fabric evolution law is further proposed to guide the fabric anisotropy evolving towards a unique critical state under continuous shear. The yield surface, hardening law and dilatancy relation of the model feature an explicit dependence on the fabric anisotropy, and are hence affected by its evolution during the deformation of sand. The model formulation leads naturally to a non-coaxial flow rule which enables it to capture the non-coaxial behaviour in sand with ease.We have further applied the model to the prediction of shear localisation in sand.We identify two competing mechanisms dictating the occurrence and further development of shear band in sand, one attributable to the evolution of fabric and the other imposed by the boundary constraints. The study helps to shed light on the fundamental understanding of sand behaviour such as non-coaxility and the phenomenon of strain localisation.