Miracle-dz/UniFAR-FTUs huggingface dataset:
Steganography using the minimax eigenvalue decomposition

This paper presents result of applying the minimax eigenvalue decomposition (MED), a morphology type transform, that hides data within digital images as part of a flexible, computationally robust algorithm. This new algorithm presents a general method for hiding information within an image, although the strength of this algorithm lies in authentication. Authentication is the establishment of ownership of digital information, and is a type of watermarking. While no self-authenticating techniques are currently known, the algorithm presented here provides a certain level of self-authentication regardless of the particular information embedded in the data. The algorithm is applied to ten different images acquired over the internet, three of which are included in this document. Information in the form of a binary bit stream is inserted into each image data. A measure is created to determine how close an image containing message data is to its original image. A visual comparison is also performed. Keys, or information separate from the message data that is generated by the embedding techniques, are used to establish authenticity of the image data. This is different from most current steganography techniques that rely on embedded data integrity to establish authenticity. An analysis of the results is presented.
M2M modelling of the Galactic disc via primal: fitting to Gaia error added data

We have adapted our made-to-measure (M2M) algorithm PRIMAL to use mock Milky Way like data constructed from an N-body barred galaxy with a boxy bulge in a known dark matter potential, using M0 giant stars as tracers, with the expected error of the ESA space astrometry mission Gaia. We demonstrate the process of constructing mock Gaia data from an N-body model, including the conversion of a galactocentric Cartesian coordinate N-body model into equatorial coordinates and how to add error to it for a single stellar type. We then describe the modifications made to PRIMAL to work with observational error. This paper demonstrates that PRIMAL can recover the radial profiles of the surface density, radial velocity dispersion, vertical velocity dispersion and mean rotational velocity of the target disc, along with the pattern speed of the bar, to a reasonable degree of accuracy despite the uncertainty in the target data. In other words, the expected errors in the Gaia data are small enough for PRIMAL to recover these global properties of the disc, at least in a simplified condition, as used in this paper.
Allergen Sensitization Patterns in Atopic Children in Mersin Province of Turkey

Objective: The spectrum of allergen sensitization differs widely between countries and also regions within the same country. The aim of this study was to investigate the allergen sensitization patterns of atopic children who presented to our allergy clinic. Materials and Methods: The study retrospectively reviewed all children who presented to our clinic with a suspicion of allergic diseases and had at least one allergen sensitization between January 2014 and January 2017. Clinical diagnosis and atopy markers such as total IgE, serum eosinophil counts, skin prick test (SPT), food and inhalant specific IgE results were evaluated. Results: A total of 1307 patients were evaluated. The mean age of the children was 9.0±4.4 years and 61.9% were male. Allergic rhinitis was the most common diagnosis with a frequency of 38.9%, followed by asthma (32.9%), urticaria (15.9%) and atopic dermatitis (5.4%). Food mix specific IgE (fx5) positivity was present in 27.6% of patients. The rate of SPT positivity for food allergens was 8.3%. Eggs (4.4%), cow’s milk (2.3%) and peanut (1.7%) were found to be the most common food allergens in SPT. Inhalant specific IgE (phadiatop) positivity was present in 83.0% of the patients. The most common aeroallergens in SPT were Dermatophagoides pteronyssinus (67.9%), Dermatophagoides farinae (67.2%), Alternaria alternata (19.4%) and grass mix (17.7%). Polysensitization was found in 39.5% of the patients. One hundred and eighty seven (14.3%) patients had a negative phadiatop but positive SPT to inhalants. Among them, the most frequent allergens detected in SPT were mites (20.8%), Alternaria alternata (20.3%) and cockroach (11.8%). Among those with Alternaria monosensitization, the serum phadiatop test was negative in 50.8%. Conclusion: The distribution of allergen sensitizations in atopic children in Mersin province is reported for the first time. Alternaria alternata has emerged as a very important allergen that may be often missed in phadiatop testing.
Implications of Long-Run Risk for Asset Allocation Decisions

This paper proposes a structural approach to long-horizon asset allocation. In particular, the investor draws inferences about asset returns from a vector autoregression (VAR) with economic restrictions on the intercept, slope, and covariance matrix implied by the long-run risk model of Bansal and Yaron (2004). Comparing the optimal allocations of investors using the longrun risk VAR versus an unrestricted reduced-form VAR reveals stark differences in portfolio strategies. Long-run risk investors are quite conservative relative to reduced-form investors due to intertemporal hedging concerns. Despite the differing strategies, both investors achieve success in timing the market. The gains of the long-run risk investor appear to arise from his ability to avoid exposure to large negative events, while the reduced-form investor better capitalizes on periods of high average returns.
A Simple Free Energy for the Isotropic-Nematic Phase Transition of Rods

A free energy expression is proposed that describes the isotropic-nematic binodal concentrations of hard rods. A simple analytical form for this free energy was yet only available using a Gaussian trial function for the orientation distribution function (ODF), leading, however, to a significant deviation of the predicted binodals. The new free energy proposed here is based upon a rationalized correction to the orientational and packing entropies when using the Gaussian ODF. In combination with Parsons-Lee theory or scaled particle theory, it enables describing the isotropic-nematic phase coexistence concentrations of rods accurately using the simple Gaussian ODF for a wide range of aspect ratios.
Phylogenetic relationships of the enigmatic Carlastyanax aurocaudatus (Eigenmann) with remarks on the phylogeny of the Stevardiinae (Teleostei: Characidae)

The monotypic genus Carlastyanax Gery was defined to include Astyanax aurocaudatus, a morphologically odd species having, among other features, four teeth in the posterior premaxillary row and eight branched dorsal-fin rays. Later on, the characters used to define Carlastyanax were considered as invalid and this genus was synonymized with Astyanax. In this paper, we include Astyanax aurocaudatus in a phylogeny of the Characidae and obtain a sister-group relationship between this species and Creagrutus, within the Stevardiinae. The resurrection of Carlastyanax as a valid genus is therefore proposed. The analysis presented is the largest phylogeny of the Stevardiinae so far published. Relationships of this subfamily are also discussed.
Growth Expectations, Undue Optimism, and Short-Run Fluctuations

Abstract This paper proposes a two-step procedure in order to identify belief shocks—shocks to expectations about the current state of the economy. First, we use the Survey of Professional Forecasters to measure nowcast errors about contemporaneous output growth. Second, we extract belief shocks from nowcast errors, once by regressing them on existing measures of structural shocks and once by imposing sign restrictions on a VAR model. Using both approaches, we find that belief shocks trigger similar adjustment dynamics and a high degree of co-movement across macroeconomic variables. Belief shocks account for about onethird of short-run output fluctuations.
Microbial Communities and Associated Mineral Fabrics in Altamira Cave, Spain

Evidences of microbial colonizations were observed in Altamira Cave, Spain. These consisted of distinct small coloured colonies, both on walls and ceiling, mainly located in the area near the cave entrance, which progressed until reaching the Polychromes Hall. The colonizations were characterized by a high morphological and microstructural variability and related to biomineralization processes. Two main types of CaCO3 deposits were related to the colonies: rosetteor nest-like aggregates of rhombohedral calcite crystals, and spheroid to hemispheroid CaCO3 elements. Colonies distribution seems to be controlled by microenvironmental conditions inside the cavity. The areas of the cave showing higher temperature, relative humidity, and CO2 biomineralization capability.
Comparative study of the motivation of professionals in instructing rooms and dental chairs

Background: The objective of this study was to compare the motivation and oral hygiene instruction conducted in the dental chair compared with that in the instructing room. Materials and Methods: Initially, we selected 34 patients that were divided into two groups of equal numbers. The patients were selected from a specialization course in periodontics and were required to be suffering from gingivitis. Initially, after diagnosis and treatment planning, the patients were treated with periodontal scaling and root planning. At the time of motivation and oral hygiene instruction, the patients were randomly selected. They were taken to the instructing room for oral hygiene or received the same procedures in the dental chair itself. The indicators of periodontal health were visible plaque and gingival bleeding index. There were two tests: An initial test and a second test 1 week later. Data from the two indicators were transformed into percentages and then into arc cosines and were compared (ANOVA, Tukey’s test – P 0.05). Conclusion: In conclusion, motivation and oral hygiene instruction conducted in the dental chair and the instructing room appeared to be similar based on the tests used in this study.
Sphagnum modifies climate-change impacts on subarctic vascular bog plants.

Summary 1. Vascular plant growth forms in northern peatlands differ in their strategies to cope with the harsh climate, low nutrient availability and progressively increasing height of the Sphagnum carpet in which they grow. Climate change may therefore affect growth forms differentially, both directly and through changes in the length growth of Sphagnum mosses. However, the role of mosses as modifiers of climate-change effects on vascular plants has been largely overlooked so far. We investigated the direct and Sphagnum mediated effects of experimental changes in summer, winter and spring climate on four species of contrasting growth forms (evergreen and deciduous shrubs, graminoid, forb) in a subarctic bog, by studying their biomass and nitrogen losses through leaf litter, and the length growth of the two shrubs. 2. Direct and indirect effects of summer warming differed among the growth forms. Enhanced Sphagnum overgrowth of leaves due to summer warming initially stimulated leaf litter losses of the evergreen shrub Empetrum nigrum . However, changes in its shoot morphology, related to an apparent small increase in its length growth, prevented further effects. A stronger increase in stem growth of the deciduous shrub Betula nana in response to summer warming directly reduced its leaf litter mass, N concentration and N losses. The changed allocation prevented indirect, Sphagnum -mediated effects on its leaf and N dynamics through overgrowth of buds. In contrast, leaf litter mass, N concentrations or N losses of the forb Rubus chamaemorus and the graminoid Calamagrostis lapponica were not affected by summer warming or enhanced Sphagnum growth. 3. Increases in winter snow cover, with or without spring warming, did not affect shrub growth, nor the total shoot leaf litter mass or N dynamics of any of the growth forms. 4. Altogether, summer warming is likely to enhance Sphagnum overgrowth of small shrubs with a limited growth response such as Empetrum . Moreover, increased vertical growth may allow Sphagnum to keep pace with inclined growing, responsive shrubs such as Betula . This might prevent net longer-term positive effects of summer warming on the vascular plant canopy height. However, leaf litter and N losses are more likely to be affected by direct warming effects on shoot morphology and allocation than by Sphagnum growth. The different responses of the growth forms to summer warming suggest that both direct and Sphagnum -mediated climate effects have the potential to change the vascular plant community and N dynamics in peatlands.
Lightning activity, rainfall and flash flooding – occasional or interrelated events? A case study in the island of Crete

Abstract. The majority of cyclones passing over Crete in late autumn to early winter originate from southwest, west and northwest and are of varying size and intensity. A number of these cyclones cause flash floods. The present study reports the possible relationships between lighting activity and high precipitation related to flash flood events. In this study an attempt was made to correlate the lightning number and location, recorded by the ZEUS lightning detection system, with the rainfall characteristics for sixteen rain events (4 flood and 12 non-flood events) on the island of Crete, during the period 2008–2009. Spatiotemporal analysis of rain and rain rate with flash count was performed with respect to distance (radius) of flashes from raingauge location at various temporal scales, in order to examine the correlation of accumulated rainfall and lightning activity. The maximum attained statistical significant correlation was obtained within a circular area of an average radius of 15 km around the raingauge, and an average time lag of flash count prior precipitation accumulation of 15 min. The maximum correlation between the lightning and rainfall data is obtained for shorter time lags for the flood events (15 min) than the non-flood events (25 min), that could reflect the faster propagation of flood triggering storms due to high convective activity. Results show increased lightning activity occurring during flood triggering storms, by an average of four times higher. Furthermore, there is evidence that the number of flashes that occur during a precipitation event is related to precipitation depth when the latter is adequate to produce a flood event. Differences between flood and non-flood producing storms need to be further assessed by analyzing more independent parameters, including the synoptic conditions and dominant flash flood hydrological generating processes.
Magmatic cristobalite and quartz in the NWA 856 Martian meteorite

Abstract— Silica‐rich late‐stage crystallization pockets in the Martian meteorite Northwest Africa (NWA) 856 were investigated by transmission electron microscopy (TEM). The pockets occur as wedges between maskelynite laths or between maskelynite and pyroxene. They consist of elongated grains of cristobalite and quartz embedded in a silica‐rich glass. Interstitial to the amorphous phase and silica minerals, a number of small accessory minerals have been identified, typical for late‐stage crystallization products. They are ilmenite, tranquillityite, fayalite, troilite, baddeleyite, apatite, and chloroapatite. Cristobalite and quartz are shocked, as revealed by the occurrence of numerous amorphous lamellae. This assemblage suggests metastable dendritic crystallization under hydrous conditions. Cristobalite crystallization was probably facilitated by the presence of impurities such as Na or H2O. Our observations show that silica minerals can be formed under magmatic conditions on Mars.
Parental Socio-Economic Status as a Determinant Factor of Academic Performance of Students in Regional Examination: A Case of Dessie Town, Ethiopia.

Parental socioeconomic status is among the widely cited factors that has strong association with academic performance of students. Explanatory research design was employed to assess the effects of parents’ socioeconomic status on the academic achievement of students in regional examination. To that end, regional examination result of 538 randomly selected students from thirteen junior secondary schools has been analysed using percentage, independent samples t-tests, Spearman’s rho correlation and one way ANOVA. The results of the analysis revealed that socioeconomic status of parents (particularly educational level and occupational status of parents) has strong association with the academic performance of students. Students from educated and better off families have scored higher result in their regional examination than their counterparts. Being a single parent student and whether parents are living together or not have also a significant impact on the academic performance of students. Parents’ age did not have a significant association with the performance of students.
The Effect of Distortions on Managerial Incentives and Competition in a Global Market

This thesis examines the impact of competition and international trade on managerial in- centives when there exist contractual distortions. The manager can decide to exert e¤ort on a cost-reducing or a non-contributory task, where the owner does not observe the total level of e¤ort and the distribution of e¤ort among both tasks. I show that when managerial e¤ort is imperfectly veri able, the likelihood that trade-openness increases the degree of market competition, and consequently total consumer welfare, is higher than in the rst-best situ- ation. When the degree of contractual distortions for a given industry is allowed to di¤er across countries, countries that experience the least amount of distortions are the most likely to bene t from trade. Secondly, at the rst-best level of e¤ort, over-incentivized managers cause the degree of market competition to decrease over time, which reduces the amount of available varieties in equilibrium. When rms experience contractual distortions, this e¤ect is reduced. Less e¢ cient rms are then able to survive in the market, which increases the degree of market competition and as a result the amount of available varieties and aggregate consumer welfare.
Excitation of transverse magnetic tube waves in stellar convection zones. III. Effects of metallicity on wave energy spectra and fluxes

In the previous two papers of this series, we developed an analytical method describing the generation of transverse tube waves in stellar convection zones and used it to compute the wave energy spectra and fluxes for late-type stars with the solar metal abundance (population I stars). We now extend these calculations to population II stars with effective temperatures ranging from T e f f = 2500 K to 10000 K, gravities log g = 3-5, and with three different metal abundances: 1/10, 1/100 and 1/1000 of solar metallicity. The obtained results are valid only for a single magnetic flux tube and they show that the effects of metallicity are important only for cool stars with T e f f < 6000 K and that the amount of the generated wave energy decreases roughly by an order of magnitude for every decrease of the metallicity by an order of magnitude. The maximum wave energy flux generated in population II stars is 3 x 10 9 erg cm - 2 s - 1 and it is practically the same for stars of different gravities and metallicities.
Foraging efficiencies of competing rodents: why do gerbils exhibit shared-preference habitat selection?

Two coexisting gerbil species, Gerbillus allenbyi (26 g) andG. pyramidum (40 g), exhibit shared-preference optimal habitat selection. In a mosaic of stabilized sands and semistabilized dunes, both species primarily prefer the semistabilized-dune habitat. We hypothesized that foraging benefit, due to the lower amount of loess in the semistabilized dunes, is the underlying cause for this preference. We tested this by measuring foraging efficiencies (giving-up density of seeds) in both manipulated foraging substrates (sand and loess) and natural habitats (semistabilized dunes, stabilized sands, and loess plateau). We also compared harvest rates on sand and loess. We used the loess substrate and loess plateau habitat to exaggerate the effect of loess on the gerbils' foraging behavior. Regarding foraging substrate, gerbils had significantly higher foraging efficiencies on sand in the field. They also had significantly higher harvest rates on sand in the laboratory. Regarding habitats, both species were more efficient in semistabilized dunes than in stabilized sands or loess plateau. Additional results suggested that the area surrounding a foraging patch had an important role in predator avoidance. We concluded that the semistabilized-dune habitat allowed gerbils to forage more efficiently in a patch, because it is easier to dig for seeds in the sandy substrate found there, and because gerbils enjoyed lower predatory risk traveling to and from the seed patch. The results supported the hypothesis that foraging benefit is the basis of the shared-preference habitat selection of the gerbil species
Characterizing stone tools by rock‐magnetic methods

Of the many petrophysical properties such as acoustic velocity, dielectric constant, electrical resistivity, etc., the widest variation is shown by magnetic responses. Susceptibilities commonly range over 4 orders of magnitude between different lithic samples. Thus, magnetic properties show great potential for the characterization, provenancedetermination, thermal history, and treatment of stone tools and masonry. In order of increasing complexity and decreasing value to the archaeologist, we recommend lowfield susceptibility, saturation remanence, hysteresis ratios, isothermal remanence acquisition, and alternating field demagnetization of a saturation remanence. The natural remanence (NRM) is rarely of any value in characterizing artifacts. The physical basis for this discrimination is the nature of the magnetic minerals, their abundance and distribution through the sample, and, for remanence-bearing minerals, their domain structure, crystallographic perfection, and grain-size. These characteristics may be changed in distinctive ways by cultural effects such as percussion or fire, and surface conditions such as frost action, forest fires, or subsequent weathering. © 1998 John
Price and Yield As Sources of Variability of Farm Revenues in Transition Economies: The Case of Armenia

In transition economies, the shift to a market system has been accompanied by relevant evolutions of farm income level. Sustainability of farming depends not only on the level but also on the variability of economic results over time. Climatic changes and increasing market uncertainty make small-scale farmers particularly vulnerable to this. This paper analyses revenue variability of the five main crops in Armenia and, by using variance decomposition, it assesses what portion of it is associated with prices and yields and whether a natural hedge exists. The analysis accounts for presence of trends in yield, price and revenue - a situation commonly encountered in transition economies. Variability of revenues of single crops is high. While in some crops the variance associated with price exceeds that of yield, in other cases the opposite occurs. Policy and methodological insights regarding how to manage and to study revenue risk in transition economies are discussed.