Miracle-dz/UniFAR-FTUs huggingface dataset:
Personal Bankruptcy Law and Entrepreneurship A Quantitative Assessment ∗

Every year 400,000 entrepreneurs fail and 20% of them file for bankruptcy. Thus the personal bankruptcy law has important implications for entrepreneurship. The option to declare bankruptcy encourages entrepreneurship through providing insurance since entrepreneurs may default in bad times. However, perfectly competitive financial intermediaries take the possibility of default into account and they charge higher interest rates which reflect these default probabilities. Thus personal bankruptcy provides insurance at the cost of worsening credit conditions. We develop a quantitative general equilibrium model of occupational choice that examines the effects of the US personal bankruptcy law on entrepreneurship. The model explicitly incorporates the US legislative framework and replicates empirical features of the US economy regarding entrepreneurship, wealth distribution and bankruptcy filings by entrepreneurs. Our quantitative evaluation shows that the current US bankruptcy law is too lenient. It provides too much insurance at the expense of worsened credit conditions. According to our simulations, halving the wealth exemption level from the current one would increase entrepreneurship, the median firm size, welfare and social mobility without increasing inequality. However, eliminating the possibility of bankruptcy completely would reduce welfare and entrepreneurship. ∗We thank Alex Michaelides for his continuous support and valuable comments, and Francesco Caselli and Maitreesh Ghatak for helpful comments at various stages of this research. We are also grateful to Daniel Becker, Wouter Den Haan, Emmanuel Frot, Alberto Galasso, Bernardo Guimaraes, Christian Julliard, Rachel Ngai, Alwyn Young and participants at the LSE macro and development seminars. †Email address: j.mankart@lse.ac. uk ‡Email address: g.rodano@lse.ac. uk
Experimental investigation of BAW propagation in lithium tantalate oxide single crystals under the influence of uniaxial pressure

The features of bulk acoustic wave (BAW) propagation in crystals of symmetry 3m under uniaxial pressure at room temperature were examined. Acoustic modes, cuts, and stresses directions which would be used to determine the third-order elastic constants (TOEC), have been defined. BAW phase velocities as well as their pressure dependences in basic and rotated cuts of LiTaO3 crystal have been investigated experimentally.
A Study of Composite or Hybrid Classifiers for Knowledge Discovery

There are several well-known techniques for knowledge discovery such as neural networks, discriminant analysis, etc. This article compares the forecasting accuracy of five models (two parametric and three nonparametric) and proposes composite (or hybrid) methods based on combining the individual methods. Basically, a composite classifier makes use of "trained" models whose "expertise" is combined to obtain an optimal classifier. All the methods are illustrated and evaluated using marketing data related to the problem of deciding whether a supermarket should carry a new product. All methods except one performed considerably better on predicting the reject decision accurately than the accept decision. However, when hybrid methods were devised and tested, the performance on "accept" decisions improved dramatically, while the overall performance was almost the same as before. Moreover, no pure method dominated any of the four hybrid methods. We also performed a cost analysis to show that, depending upon the ratio of the costs of Type 1 and Type 2 errors, the hybrid methods could outperform all the pure methods in terms of total profit for the supermarket.
Temperature Map of the Virgo Cluster of Galaxies Observed with ASCA

The temperature distribution of the intracluster medium (ICM) in the Virgo Cluster of galaxies has been derived from extensive mapping observations with ASCA covering an area of 19 deg2. In the spectral analysis, the inner region within a radius of ~60' from M87 is characterized by an ICM temperature of kT ~ 2.5 keV with little variation. On the other hand, the outer regions indicate significant variation of the temperature with an amplitude of about 1 keV. The temperature map was produced from the hardness ratio (HR) values with a resolution of about 5'. Besides the previously reported hot region with kT > 4 keV between M87 and M49, several hot regions with kT = 3-4 keV are detected in the cluster outskirts. The autocorrelation function for the HR variation shows that the temperature variation is correlated within a size of about 300 kpc, suggesting that gas blobs falling in the Virgo Cluster have a typical size of groups of galaxies. A correlation with the velocity dispersion of member galaxies shows that only the northwest region indicates an unusually large βspec value of 2-4. The upper limit for extended nonthermal emission in the Virgo Cluster is obtained to be LX ~ 9 × 1041 ergs s-1 in the 2-10 keV band. We discuss that these features consistently indicate that the Virgo Cluster is in a relatively early stage of the cluster evolution.
Factors that contribute to the emotional wellbeing, educational success and social connectedness of those arriving in one local authority as unaccompanied asylum seeking children

Building on research with unaccompanied asylum-seeking children and young people (UASC) from a resilience perspective, this study investigates the protective mechanisms that support UASC in adapting to life in the UK. ‘Positive adaptation’ is framed as: emotional wellbeing, educational success and social connectedness. Two strands of research are carried out: 1) focus groups that investigate views of key adults (foster carers and social care staff) working with UASC, in order to understand how they frame UASC’s positive adaptation; the protective mechanisms they have experienced to promote emotional wellbeing; and approaches they have found successful in addressing mental health difficulties; and 2) individual interviews, using an Interpretative Phenomenological Analytical approach, with five UASC who were considered resilient. Interviews investigated how individual UASC felt that they had coped with their experiences. I relate findings to resilience frameworks that recognise a complex matrix of risk factors, vulnerability and protective mechanisms operating for each individual at the individual, the family and community/societal level. Findings provide a strong argument for a psycho-social approach to mental health with UASC, establishing stability, whilst building on personal coping strategies, personal strengths and sense of autonomy and competence. Implications for services and interventions are discussed.
Time-to-Fatigue During Incline Treadmill Running: Implications for Individualized Training Prescription

Abstract Ferley, DD and Vukovich, MD. Time-to-fatigue during incline treadmill running: Implications for individualized training prescription. J Strength Cond Res 29(7): 1855–1862, 2015—Uphill running has been touted as a key interval training tactic for distance runners despite few scientifically derived recommendations for individualized training prescription. To date, a majority of uphill training research has focused on shorter, faster training bouts; however, longer, slower bouts based on an individual's velocity at maximum oxygen consumption (Vmax) may prove more effective. One potential longer bout length may be associated with the time Vmax can be maintained (Tmax), an approach proven effective in level-grade interval training. Therefore, the purpose of this investigation included examining the Tmax, heart rate, and test-retest reliability of incline treadmill running (INC) on a 10% grade at 65, 70, 75, 80, and 85%Vmax compared with level-grade running at Vmax. Twelve moderately trained distance runners (age, 26.4 ± 4.8; body mass, 64.3 ± 12.9 kg; height, 171.2 ± 9.3 cm; and V[Combining Dot Above]O2max, 56.6 ± 7.6 ml·min−1·kg−1) completed 2 Tmax INC trials at each submaximal Vmax and a level-grade Tmax at Vmax. The dependent variables were Tmax, heart rate plateau (HRPlateau), and half-time to heart rate plateau (½HRPlateau) of each condition. Statistical significance was set to p ⩽ 0.05. Student's t-test revealed no significant differences in Tmax, HRPlateau, and ½HRPlateau between trials 1 and 2 at any INC condition. One-way analysis of variance revealed significant differences in (a) Tmax during INC at 75, 80, and 85%Vmax and level-grade at Vmax and (b) ½HRPlateau during INC at 80 and 85%Vmax and all other conditions. In conclusion, Tmax and heart rate dynamics during INC proved reliable, and simple regression analysis revealed ∼68%Vmax during INC yields the same level-grade Tmax at Vmax.
Genetic Characterization of Russian Honey Bee Stock Selected for Improved Resistance to Varroa destructor

ABSTRACT Maintenance of genetic diversity among breeding lines is important in selective breeding and stock management. The Russian Honey Bee Breeding Program has strived to maintain high levels of heterozygosity among its breeding lines since its inception in 1997. After numerous rounds of selection for resistance to tracheal and varroa mites and improved honey production, 18 lines were selected as the core of the program. These lines were grouped into three breeding blocks that were crossbred to improve overall heterozygosity levels of the population. Microsatellite DNA data demonstrated that the program has been successful. Heterozygosity and allelic richness values are high and there are no indications of inbreeding among the three blocks. There were significant levels of genetic structure measured among the three blocks. Block C was genetically distinct from both blocks A and B (FST = 0.0238), whereas blocks A and B did not differ from each other (FST = 0.0074). The same pattern was seen for genic (based on numbers of alleles) differentiation. Genetic distance, as measured by chord distance, indicates that all of the 18 lines are equally distant, with minimal clustering. The data indicate that the overall design of the breeding program has been successful in maintaining high levels of diversity and avoiding problems associated with inbreeding.
Quantitative comparison of different-shaped wavefront sensors and preliminary results for defocus aberrations on a mechanical eye.

PURPOSE There is a general acceptance among the scientific community of Cartesian symmetry wavefront sensors (such as the Hartmann-Shack (HS) sensor) as a standard in the field of optics and vision science. In this study it is shown that sensors of different symmetries and/or configurations should also be tested and analyzed in order to quantify and compare their effectiveness when applied to visual optics. Three types of wave-aberration sensors were developed and tested here. Each sensor has a very different configuration and/or symmetry (dodecagonal (DOD), cylindrical (CYL) and conventional Hartmann-Shack (HS)). METHODS All sensors were designed and developed in the Physics Department of the Universidade de São Paulo--São Carlos. Each sensor was mounted on a laboratory optical bench used in a previous study. A commercial mechanical eye was used as control. This mechanical eye has a rotating mechanism that allows the retinal plane to be positioned at different axial distances. Ten different defocus aberrations were generated: 5 cases of myopia from -1D to -5D and 5 cases of hyperopia, from +1D to +5D, in steps of 1D following the scale printed on the mechanical eye. For each wavefront sensor a specific image-processing and fitting algorithm was implemented. For all three cases, the wavefront information was fit using the first 36 VSIA standard Zernike polynomials. Results for the mechanical eye were also compared to the absolute Zernike surface generated from coefficients associated with the theoretical sphere-cylinder aberration value. RESULTS Precision was analyzed using two different methods: first, a theoretical approach was used by generating synthetic Zernike coefficients from the known sphere-cylinder aberrations, simply by applying sphere-cylinder equations in the backward direction. Then comparisons were made of these coefficients with the ones obtained in practice. Results for DOD, HS and CYL sensors were, respectively, as follows: mean of root mean square (RMSE) for all aberrations, when theoretical Zernike coefficients were used as control, was 0.22, 0.66 and 0.26 microns; RMSE of sphere-cylinder values when compared to autorefractor measurements was 0.18D, 0.22D and 0.35D for sphere, 0.14D, 0.24D and 0.17D for cylinder, 34.36 degrees, 35.16 degrees and 26.36 degrees for axis; RMSE of sphere-cylinder values when theoretical values were used as control was 0.11D, 0.29D and 0.46D for sphere, 0.15D, 0.28D and 0.17D for cylinder, 19.71 degrees, 25.56 degrees and 18.56 degrees for axis. CONCLUSION The main conclusion is that the symmetry of an optical sensor is not an important consideration when measuring typical eye aberrations such as defocus (myopic and hyperopic), but there are differences. In this sense, the polar symmetry sensors render results that are equivalent to the traditional Cartesian Hartmann-Shack sensor, but furnish an easier method for determining the optical center.
The Effects of Astigmatism on Sensitivity to Sinusoidal and Square Wave Gratings

Abstract Contrast thresholds for different spatial frequencies were measured for four individuals with optimum optical correction and with 2 D of astigmatismm induced at various meridians. Sensitivity for sine waves of low spatial frequencies was unaffected by the astigmatism; however, gross changes were found at high spatial frequencies when the astigmatism was induced with the power meridian perpendicular to the orientation of the stripes. For square waves, the results were comparable at high spatial frequencies, but astimgatism also produced a decrement at 0.2 cycles/degree. This latter effect can be predicted by assuming that astigmatism results in a loss of higher order harmonics in the response to square waves.
Arrhythmic Rats after SCN Lesions and Constant Light Differ in Short Time Scale Regulation of Locomotor Activity

Circadian rhythm disruption (i.e., arrhythmicity) in motor activity is an abnormal behavioral pattern. In rats, it can be caused by the lesion of the hypothalamic suprachiasmatic nucleus (SCN) and by prolonged exposure to constant light (LL). We carried out a comparative study of these arrhythmic phenotypes to assess the role of the SCN in the regulation of the motor output beyond circadian rhythmicity. Motor activity series were studied in rats that had become arrhythmic as a result of 1) LL exposure at 2 light intensities: 300 lux (LL300) and 1.3 lux (LL1.3), and 2) SCN lesion (SCNx). The Fourier spectra, the fractal Hurst coefficient (H) from the autocorrelation function, and the β slope from the power spectral density were calculated in data sections at baseline, when the rats were still rhythmic, and later at stages with undetectable circadian rhythms. In the LL300 group, high power content was detected at frequencies of 8 to 4 h (i.e., ultradian). Lower power content for these harmonics was found in the LL1.3 group, whereas no dominant harmonics appeared in the SCNx group. Independently of the manifestation of circadian rhythm, H values were higher and more sustained in time in rats exposed to LL 300 but gradually decreased in rats exposed to LL1.3. Fractal correlation was found in control DD group but was absent in the SCNx group. We conclude that scale-invariant regulation of the motor pattern by SCN activity is dependent on light intensity but independent of the circadian rhythm output. Adjusting the light intensity by modifying the coupling degree between the population of oscillations could affect the dynamics of each individual oscillator in the SCN, making it less predictable.
Oral Vaccination of Free-Living Badgers (Meles meles) with Bacille Calmette Guérin (BCG) Vaccine Confers Protection against Tuberculosis

A field trial was conducted to investigate the impact of oral vaccination of free-living badgers against natural-transmitted Mycobacterium bovis infection. For a period of three years badgers were captured over seven sweeps in three zones and assigned for oral vaccination with a lipid-encapsulated BCG vaccine (Liporale-BCG) or with placebo. Badgers enrolled in Zone A were administered placebo while all badgers enrolled in Zone C were vaccinated with BCG. Badgers enrolled in the middle area, Zone B, were randomly assigned 50:50 for treatment with vaccine or placebo. Treatment in each zone remained blinded until the end of the study period. The outcome of interest was incident cases of tuberculosis measured as time to seroconversion events using the BrockTB Stat-Pak lateral flow serology test, supplemented with post-mortem examination. Among the vaccinated badgers that seroconverted, the median time to seroconversion (413 days) was significantly longer (p = 0.04) when compared with non-vaccinated animals (230 days). Survival analysis (modelling time to seroconversion) revealed that there was a significant difference in the rate of seroconversion between vaccinated and non-vaccinated badgers in Zones A and C throughout the trial period (p = 0.015). For badgers enrolled during sweeps 1–2 the Vaccine Efficacy (VE) determined from hazard rate ratios was 36% (95% CI: -62%– 75%). For badgers enrolled in these zones during sweeps 3–6, the VE was 84% (95% CI: 29%– 97%). This indicated that VE increased with the level of vaccine coverage. Post-mortem examination of badgers at the end of the trial also revealed a significant difference in the proportion of animals presenting with M. bovis culture confirmed lesions in vaccinated Zone C (9%) compared with non-vaccinated Zone A (26%). These results demonstrate that oral BCG vaccination confers protection to badgers and could be used to reduce incident rates in tuberculosis-infected populations of badgers.
Planar MESFET grid oscillators using gate feedback

A method for quasi-optically combining the output power of MESFETs in which drain and source leads couple directly to the radiated field is introduced. The design consists of a planar grid of devices placed in a Fabry-Perot cavity. Capacitive feedback is provided to the gate, allowing oscillation at much higher frequencies than previous grids. The oscillation frequency is dependent on the device characteristics, the resonator cavity, and the symmetries of the grid. A transmission-line model for the grid is discussed and used to design two oscillator arrays. A 16-element grid has produced 335 mW of power at 11.6 GHz with a DC-to-RF conversion efficiency of 20%. This design was scaled to produce a 36-element grid oscillator with output power of 235 mW at 17 GHz. These results represent a significant improvement in the performance of planar grid oscillators. The planar configuration of the grid is very convenient for monolithic integration and is easily scalable to millimeter-wave frequencies. >
Osmotically induced volume and turbidity changes of Escherichia coli due to salts, sucrose and glycerol, with particular reference to the rapid permeation of glycerol into the cell.

SUMMARY Increases in turbidity of Escherichia coli strain K12 due to added non-permeant salts (NaCl and MgCl2) and sucrose are strictly dependent on medium osmotic pressure, when correction is made for changes in medium refractive index. The volume of the whole cell and the fraction of the intact cell bounded by the cyto-plasmic membrane have been measured by dextran and [14C]sucrose exclusion spaces. Increases in medium osmotic pressure due to non-penetrant medium solutes cause outflow of water across the cytoplasmic membrane and contraction away from the cell wall (plasmolysis), corresponding to the increases in turbidity. In addition salts (NaCl and MgCl2) cause appreciable contraction in volume of the whole cell, presumably due to ionic interaction with the wall; sucrose causes only marginal decreases in whole cell volume. Electron micrographs of cells plasmo-lysed by NaCl or MgCl2, but not by sucrose, show numerous adhesion points between the wall and the cytoplasmic membrane. Glycerol penetrates the cell to the same extent as water, but because of its slower rate of penetration, transient decreases in volume occur which can be measured in a stopped-flow spectrophotometer due to concomitant increases in turbidity. In cells grown on glucose-containing medium the rate of glycerol penetration is non-saturating. In cells grown on glycerol an additional saturating-facilitated diffusion system is induced. Mutants deleted in the facilitator (F-) are available and do not show facilitated diffusion when grown on glycerol. Water exit and glycerol penetration in glucose-grown cells show transition points in Arrhenius plots corresponding to phase changes of the membrane lipids.
Semi-dense Visual Odometry for a Monocular Camera

We propose a fundamentally novel approach to real-time visual odometry for a monocular camera. It allows to benefit from the simplicity and accuracy of dense tracking - which does not depend on visual features - while running in real-time on a CPU. The key idea is to continuously estimate a semi-dense inverse depth map for the current frame, which in turn is used to track the motion of the camera using dense image alignment. More specifically, we estimate the depth of all pixels which have a non-negligible image gradient. Each estimate is represented as a Gaussian probability distribution over the inverse depth. We propagate this information over time, and update it with new measurements as new images arrive. In terms of tracking accuracy and computational speed, the proposed method compares favorably to both state-of-the-art dense and feature-based visual odometry and SLAM algorithms. As our method runs in real-time on a CPU, it is of large practical value for robotics and augmented reality applications.
HIGHER ORDER ASYMPTOTIC THEORY WHEN A PARAMETER IS ON A BOUNDARY WITH AN APPLICATION TO GARCH MODELS

Andrews (1999, Econometrica 67, 1341–1383) derived the first-order asymptotic theory for a very general class of estimators when a parameter is on a boundary. We derive the second-order asymptotic theory in this setting in some special cases. We focus on the behavior of the quasi maximum likelihood estimator (QMLE) in stationary and nonstationary generalized autoregressive conditionally heteroskedastic (GARCH) models when constraints are imposed in the maximization procedure. We show how in this case both a first- and a second-order bias appear in the estimator and how the bias can be quite large. We provide two types of bias correction mechanisms for the researcher to choose in practice: either to bias correct only for a first-order bias or for a first- and second-order bias. We show that when some constraints are imposed, it is advisable to bias correct not only for the first-order bias but also for the second-order bias.We thank Bruce Hansen and two referees for helpful comments. The first author gratefully acknowledges financial support from the MSU Intramural Research Grants Program. The second author gratefully acknowledges financial support from the ESRC.