Miracle-dz/UniFAR-FTUs huggingface dataset:
On the modeling of sound propagation over multi-impedance discontinuities using a semiempirical diffraction formulation

Several approximate extensions of the semi-empirical De Jong model [De Jong et al., J. Sound and Vib. 86, 23–46 (1983)] are considered for the prediction of sound propagation over multiple impedance discontinuities. A limitation in the original formulation of the De Jong model is highlighted and a modified form that overcomes this limitation is derived based on reciprocity. This leads to the development of a model for multiple impedance discontinuities that can be used for the investigation of sound-wave propagation above a mixed, striped soft ground that is created by either porous absorbent strips, embedded grooves, or wells with different depths. The accuracy of the model is validated against the boundary element method. It is then used to evaluate the importance of the imaginary part of the admittance of the ground strips on sound attenuation along welled surface. It is shown that the attenuation performance of a surface with multiple impedance discontinuities is high when the imaginary part of the av.
Genetic correlations between female fertility and production traits in South African Holstein cattle

Female fertility is increasingly gaining importance in national dairy cattle breeding objectives worldwide. In South Africa, there is no routine prediction of breeding values for reproductive performance in dairy cattle and selection is mainly focused on production traits. The objective of this study was to estimate genetic parameters among female fertility traits (age at first calving and calving interval) and first, second and third lactation production traits in South African Holstein cattle to determine the effect that selection on production per se may have on female fertility. Performance records on 40 437 South African Holstein cows in 766 herds were used. (Co)variance estimates were obtained by multitrait analysis, using the REML procedure. Heritability estimates were moderate for age at first calving (0.24 ± 0.02) and low for calving interval (0.03 ± 0.01). Genetic correlations between age at first calving and yield traits were low to moderately negative, ranging from -0.17 ± 0.07 with second lactation butterfat percentage to -0.50 ± 0.05 with first lactation butterfat yield. Calving interval had moderate to highly positive genetic correlations with yield traits, ranging from 0.37 ± 0.10 with second lactation milk yield to 0.69 ± 0.06 with first lactation milk yield. Correlations between female fertility and butterfat and protein percentages across all lactations, were close to zero. The observed antagonistic relationship between calving interval and production traits highlights the need to include calving interval in breeding objectives for South African Holstein cattle. Keywords : Age at first calving; calving interval; milk yield South African Journal of Animal Science Vol. 37 (3) 2007: pp.180-188
Temporal Analysis of Political Instability through Descriptive Subgroup Discovery

This paper analyzes the Political Instability Task Force (PITF) data set using a new methodology based on machine learning tools for subgroup discovery. While the PITF used static data, this study employs both static and dynamic descriptors covering the 5-year period before onset. The methodology provides several descriptive models of countries especially prone to political instability. For the most part, these models corroborate the PITF's findings and support earlier theoretical works. The paper also shows the value of subgroup discovery as a tool for developing a unified concept of political instability as well as for similar research designs.
Coronene and pyrene (5, 7)-member ring defects: Infrared spectra, energetics and alternative formation pathways

PAHs are known to be one of the carriers of the ubiquitous aromatic IR bands. The IR spectra of many objects show IR emission features derived from PAH molecules of different size. Still some of the characteristics of the emitting population remain unclear. The emission bands show details which cannot be explained so far. These unidentified IR features require further laboratory and observational investigations. We present a theoretical study of the IR spectra of PAHs containing (5,7)-member ring defects, focusing on pyrene and coronene. Using density functional theory, we investigate the effects of such defects on the IR spectra of pyrene and coronene and their cations and anions. In addition, we explore parts of the potential energy surface of the neutral species and discuss alternative formation pathways. The addition of (5,7)-membered ring defects in pyrene and coronene results in a change of the IR spectra, both molecules lose their typical spectroscopic signature. We find shifts in the positions of the band as well as different intensities and a rise in the number of features. The boundaries in terms of the size of the PAHs exhibiting a (5,7)-membered ring defect are studied and shown. Investigation of the minimal energy pathway leads to a result of 8.21 eV for pyrene and 8.41 eV for coronene as minimum activation barriers for the transformation from ground state to defected state. Whereas pyrene retains some of its symmetry due to the symmetry exhibited by the Stone-Wales defect itself, coronene loses much more of its symmetry. The formation of these (5,7)-ring defects in PAHs may be well supported in AGB stars or PNe. Those environments strongly enable the transition from the ground state to the defect state. Therefore the knowledge of the IR spectra of these molecules will support future investigations aiming for a thorough understanding of the unidentified IR emission bands.
Re-integration of institutionalised children into society: a case study of Zimbabwe

The study examined the successes and challenges that Zimbabwe has experienced in process of reintegration of institutionalized children into society. The study was informed by the mixed methods research design. The sample comprised of nine randomly selected children’s homes out of a total of seventy two registered children‘s homes in the country. Considerable progress has been made towards achieving the goal of reintegration. The study established that a National child Care Standards document has been drafted by the Ministry of Labour and Social services to facilitate the process of reintegration ,while most institutions have built family type structures to replace the dormitory set up that existed before. Support systems to enhance the process of reintegration have been put in place as evidenced by organs such the National Action Plan housed under the Ministry of Labour and Social Services. The main challenges identified by the study were inadequate financial resources to carry a full scale reintegration process and the difficulties experienced in identifying institutionalized children’s familial origins. The study recommends that government avails more funds through the department of social services to enhance the reintegration process.
Early Miocene sequence development across the New Jersey margin

Sequence stratigraphy provides an understanding of the interplay between eustasy, sediment supply and accommodation in the sedimentary construction of passive margins. We used this approach to follow the early to middle Miocene growth of the New Jersey margin and analyse the connection between relative changes of sea level and variable sediment supply. Eleven candidate sequence boundaries were traced in high‐resolution multi‐channel seismic profiles across the inner margin and matched to geophysical log signatures and lithologic changes in ODP Leg 150X onshore coreholes. Chronologies at these drill sites were then used to assign ages to the intervening seismic sequences. We conclude that the regional and global correlation of early Miocene sequences suggests a dominant role of global sea‐level change but margin progradation was controlled by localized sediment contribution and that local conditions played a large role in sequence formation and preservation. Lowstand deposits were regionally restricted and their locations point to both single and multiple sediment sources. The distribution of highstand deposits, by contrast, documents redistribution by along shelf currents. We find no evidence that sea level fell below the elevation of the clinoform rollover, and the existence of extensive lowstand deposits seaward of this inflection point indicates efficient cross‐shelf sediment transport mechanisms despite the apparent lack of well‐developed fluvial drainage.
Corruption and the Curse: The Dictator's Choice

We develop a dynamic discrete choice model of a self-interested and unchecked ruler making decisions regarding the exploitation of a resource-rich country. This dictator makes the recursive choice between either investing domestically to live off the productivity of the country while facing the risk of being ousted, or looting the country’s riches by liquefying the resources and departing. We demonstrate that important parameters determining this choice include the level of resources, liquidity and indebtedness. We find that the dictator’s choice regarding the timing of departure is significantly related to external lending, investment and debt. We then argue that this looting phenomenon provides an explanation for the generation of corrupt economies in resource-rich countries. An empirical analysis of available corruption indices suggests that instability-led looting provides a more fundamental explanation of perceived corruption than do various social and cultural indicators or the economic theory of internal political competition.
Safety from predators or competitors? Interference competition leads to apparent predation risk

Abstract Prey often react to predation risk by foraging preferentially in the safety of cover rather than in more risky open patches. Yet this pattern of patch use also can be caused by dominant interspecific competitors. We develop a simple theory of this form of apparent predation risk that describes the patch use of an optimal forager confronted with dominant individuals. The theory predicts that subordinate animals should increase their use of safe foraging patches as the density of nearby dominants increases. We tested the theory with meadow voles (Microtus pennsylvanicus) and southern red-backed voles (Myodes gapperi). We used dyadic encounters to confirm that meadow voles are dominant over red-backed voles. We then evaluated their respective foraging patterns in pairs of covered and open patches in 4 adjacent subgrids in an old-field enclosure. Subordinate red-backed voles foraged indifferently between covered and open patches when few meadow voles were present. Red-backed voles increased their use of both patches as the number of nearby meadow voles increased. Giving-up densities were lowest, and harvesting efficiency highest, in covered patches when the number of nearby meadow voles was high. These results document competition between the 2 species and suggest that vigilance toward dominant meadow voles magnifies the risk experienced by red-backed voles in open patches. Investigators assessing foraging behavior between “safe” and “risky” patches might misinterpret the competitive effect as predation risk unless they 1st account for competition among foraging individuals.
Dispersion-dissipation analysis of 3-D continuous and discontinuous spectral element methods for the elastodynamics equation

In this paper we present a three dimensional dispersion and dissipation analysis for both the semi-discrete and the fully discrete approximation of the elastodynamics equation based on the plane wave method. For space discretization we compare different approximation strategies, namely the continuous and discontinuous spectral element method on both tetrahedral and hexahedral elements. The fully discrete scheme is then obtained exploiting a leap-frog time integration scheme. Several numerical results are presented and discussed.
Effects of fluoride exposure on some enzymatic and histopathological changes in the liver of Heteropneustes fossilis (Bloch)

Present study in fresh water fish Heteropneustes fossilis (Bloch) were exposed to sub lethal concentrations (35 mg/L and 70 mg/L) of fluoride, for 45 days & 90 days. After fluoride exposure aspartate transaminase (AST) and alanine transaminase (ALT) increased (P <0.01) after 45 & 90 days of low and high dose exposure. There were decreases of protein P > 0.05 after 90 days exposure to both low and high dose exposure. After 45days exposure p<0.01 decreases high concentration of fluoride. The lipid accumulation could have contributed to the increase of liver weight. After 45 & 90 days’ exposure of fluoride histopathological observations of liver at low & high dose concentration. As a result foci of necrosis fibrosis, pyknotic nuclei, disruptions and rupture as well as hypertrophy & hyperplasia of hepatocytes were found. The changes included swollen cells, vacuoles filled with cellular debris, focal necrosis, and dilatation of sinusoids.
Preliminary in vitro assessment of the potential toxicity and antioxidant activity of Ceiba speciosa (A. St.-Hill) Ravenna (Paineira)

The bark tea of Ceiba speciosa, a tropical tree of the Malvaceae family, is used in the Northwestern Region of Rio Grande do Sul state, Brazil, to reduce blood cholesterol levels. However, there are no scientific data on the efficacy and safety of this plant. The aim of the present study was to evaluate the in vitro antioxidant and toxic potential of bark extracts of C. speciosa. We performed a preliminary phytochemical analysis by high-performance liquid chromatography-diode array detection (HPLC-DAD) and evaluated the oxidative damage to proteins and lipids, the radical scavenging effect, and genotoxicity of the lyophilized aqueous extract (LAECs) and the precipitate obtained from the raw ethanol extract (Cs1). The phytochemical proﬁle demonstrated the presence of phenolic and ﬂavonoid compounds. The LAECs and Cs1 prevented damage to lipids and proteins at concentrations of 50 and 10 µg/mL. They also showed a scavenging effect on 2,2-diphenyl-1-pricril-hydrazyl (DPPH) radicals in a concentration-dependent manner. Furthermore, no genotoxic effect was observed at concentrations of 10, 5 and 2 µg/mL in the Comet assay. The present study is the first evaluation regarding the characterization of C. speciosa and its safety, and the results demonstrate its antioxidant potential and suggest that its therapeutic use may be relatively safe.
FDI and Taxation: A Meta-Study

Despite the continuing political interest in the usefulness of tax competition and tax coordination as well as the wealth of theoretical analyses, it still remains open whether or when tax competition is harmful. Moreover, the influence of tax differentials on multinationals' decisions is still insufficiently analyzed. Thus, economists have increasingly resorted to empirical analysis in order to gain insights on the elasticity of FDI with respect to company taxation. As a result, the empirical literature on taxation and international capital flows has grown to a similar abundance during the last 25 years as the respective theoretical literature. Its heterogeneity leads to a rising need for concise reviews on the existing empirical evidence. In this paper we extend former meta-analyses on FDI and taxation in three ways. First, we add the most recent publications unconsidered in meta-analyses up-to-date. Second, we apply a different methodology by using a broad set of meta-regression estimators and explicitly discuss which one is most suitable for application to our meta-data. Third, we address some important issues in research on FDI and taxation to the clarification of which meta-analysis can make valuable contributions. These issues are mainly: The influence of variables which might moderate effects of tax differentials (e.g. public spending), the implications of using aggregate FDI data as opposed to firm-level information on measured tax effects, the implications of bilateral effective tax rates, and the possible presence of publication bias in primary research.
Study on laminar hydathodes of Ficus formosana (moraceae) III. Salt injury of guttation on hydathodes

The salt concentrations of gutted solution of laminar hydathodes on leaf usually increase after the repetition of guttation and eva-transpiration, and thus situation may lead to injure the hydathodes. The aim of this study is to investigate the salt injury of gutted solution on hydathodes of Ficus formosana Maxim. by using electron microscopy. Ultrastructural studies show that the hypertonic stress of gutted solution caused by evaporation could lead the injury of hydathodes. The major symptoms of salt injury caused by hypertonic stress are as the follows: many electron dense particles are spread in the nucleus and other organelles; the nucleolus is condensed and then disappeared; the endomembrane system is collapsed and then entirely become osmiophilic materials in the cytoplasm. Upon dehydration, the collapsed membranes become myelin-like structures are also observed. According to different degrees of salt injury within hydathodes, the abilities of tissue's salt-tolerance are diversified and tolerance ability of the epithem is better than other tissues. These results imply that epithem possesses some special mechanisms that have been evolved to adapt the damage stress. In addition to physiological regulation, we suggest that some morphological changes such as the sinuous cell wall, proliferation of peroxisomes and the abundant endomembrane systems, and the conspicuous fluid-phase endocytosis. Epithem promotes the tolerant efficiency of vacuoles by increasing the contact surface with environment to accelerate salt tolerance.
Could statin reduce fracture risk ? Evidence from a systematic review and meta-analysis

Some studies determined that statins could reduce the risk of fractures. However, the other studies did not confirm this result. This study aims to determine whether statins was significantly associated with reduced fracture risk. The Pubmed, Cochrane library, and Embase databases were searched independently by 2 investigators to retrieve relevant studies published to Mar 21, 2015. The strength of the association between statins and fractures risk was calculated with the OR and respective 95% CIs. The significance of the pooled OR was determined by the Z test, and P-values of less than 0.05 were considered significant. A total of 17 articles of more than 1800000 individuals were included in the meta-analysis. We observed a statistically significant association between statins and fractures risk. The data showed that statins could decrease the risk of fractures (OR=0.80; 95% CI, 0.730.88; P<0.00001) in a random-effect model. When only considered the old population (more than 50 years old), our results found that statins was significantly associated with decreased fractures risk (OR=0.72; 95% CI, 0.590.87; P=0.0006). When only considered the females, we also found that statins was significantly associated with decreased fractures risk (OR=0.76; 95% CI, 0.63-0.92; P=0.005). This meta-analysis suggested that statins might decrease fracture risk in the old population and the females.
The effects of grassland management on plant performance and demography in the perennial herb Primula veris

Summary 1. Because of changing land-use practices and abandonment, many European calcareous grasslands are under increasing threat. In order to protect those grasslands that remain, better insights into how plant populations respond to different management scenarios are needed. 2. Using transition matrix models and life-table response experiment (LTRE) analysis, the effects of different management strategies (grazing, summer and autumn mowing, and no management) on plant performance and population dynamics of the perennial herb Primula veris (Primulaceae) were experimentally studied. Data were collected between 1999 and 2003 in a species-rich calcareous grassland. 3. Early grazing (May) resulted in low population growth rates ( λ 1). 4. Mowing in autumn (October) was the most favourable management scenario (mean λ = 1·213), resulting in high proportions of flowering individuals and a large seed output. Furthermore, this management yielded optimal conditions for recruitment and seedling establishment during the next growing season. 5. Summer mowing (mid-July) resulted in a similar increase of flowering and overall seed shed to autumn mowing, but recruitment rates were lower because of a dense and tall vegetation structure at the time of germination. Consequently, population growth rates (mean λ = 1·045) were lower compared with the autumn mowing regime. 6. No management of the grassland resulted in low growth rates ( λ < 0·843) and a mean annual population decline of 35%, because of high mortality rates of each life stage and a lack of recruitment. Recruitment rates were strongly reduced by lowered flowering probabilities and limited germination possibilities. 7. Synthesis and applications . This study may enable conservation managers to understand better the effects of time and type of management on population dynamics of P. v eris . In order to preserve the remaining populations of this long-lived species, management interventions can promote flowering and seed shed and reduce productivity of the vegetation by mowing in autumn. Finally, this study has clearly shown that the lack of any management, which is the fate of many abandoned calcareous grassland relicts, will seriously restrict the long-term survival of P. veris .
Epidemiological and Clinical Study of Bacterial Meningitis in Menoufia Governorate

Objectives and Background: Bacterial meningitis in children is associated with substantial excess risk of intellectual, cognitive, and auditory impairment that persists into adolescence. Continuing developmental problems of higher order language, organisation, problem solving, and central auditory function may increase learning and behavioral difficulties. The aim of this study was to evaluate clinical, laboratory and epidemiology of bacterial meningitis in Menoufia Governorate Fever Hospitals. Patients and Methods: we prospectively studied the data of 279 pediatric cases suspected to have meningitis and admitted to Menoufia Governorate fever hospitals (13 0 infants up to one year, 64 preschool age children and 85 school age children). We constructed a standardized data collection questionnaire to collect basic data, then we collected samples from blood, ceprospinal fluid (CSF) from all 279 cases to culture and isolate the organism causing meningitis after gram staining of the CSF. Results: The study showed that the prevalence of Pneumococci is significantly higher among school aged group than other groups 30/85 (35.3%), while H. influenzae was the leading cause below one year age 14/130 (10.8%). Conclusion: We found that the three major pathogens accounting for (95.7%) of bacterial meningitis in Menoufia Governorate were Streptococcal pneumonia (S. pneumonia). In infants less than 1 year, H. influenzae was the most common etiologic agent.
Loss Aversion and Lying Behavior: Theory, Estimation and Empirical Evidence

We theoretically show that loss-averse agents are more likely to lie to avoid receiving a low payoff after a random draw, the lower the ex-ante probability of this bad outcome. The ex-ante expected payoff increases as the bad outcome becomes less likely, and hence the greater is the loss avoided by lying. We demonstrate robust support for this theory by reanalyzing the results from the extant literature and with two new experiments that vary the outcome probabilities and are run doubleanonymous to remove reputation effects. To measure lying, we develop an empirical method that estimates the full distribution of dishonesty