Skewness, Individual Investor Preference, and the Cross-section of Stock Returns

We find a robust negative relation between skewness/lottery-like features, proxied by maximum return (MAX) over the last month, and future returns for stocks preferred by individual investors. This negative relation is nonexistent for the rest of stocks. We identify stocks preferred by individual investors through bundling ten stock characteristics associated with their stock preferences. The negative relation between MAX and future return is produced by the stocks preferred by individuals that account for less than 5% of the overall market capitalization. Our results are robust to alternative definitions of MAX and lottery-like features such as total, idiosyncratic, and expected skewness

Clinical and genetic profile of catecholaminergic polymorphic ventricular tachycardia in Hong Kong Chinese children

published_or_final_versio

Efficacious symmetry-adapted atomic displacement method for lattice dynamical studies

Small displacement methods have been successfully used to calculate the lattice dynamical properties of crystals. It involves displacing atoms by a small amount in order to calculate the induced forces on all atoms in a supercell for the computation of force constants. Even though these methods are widely in use, to our knowledge, there is no systematic discussion of optimal displacement directions from the crystal's symmetry point of view nor a rigorous error analysis of such methods. Based on the group theory and point group symmetry of a crystal, we propose displacement directions, with an equivalent concept of the group of $k$, deduced directly in the Cartesian coordinates rather than the usual fractional coordinates, that maintain the theoretical maximum for the triple product $V$ spanned by the three displacements to avoid possible severe roundoff errors. The proposed displacement directions are generated from a minimal set of irreducible atomic displacements that keep the required independent force calculations to a minimum. We find the error in the calculated force constant explicitly depends on the inverse of $V$ and inaccuracy of the forces. Test systems such as Si, graphene, and orthorhombic Sb2S3 are used to illustrate the method. Our displacement method is shown to be very robust in treating low-symmetry cells with a large `aspect ratio' due to huge differences in lattice parameters, use of a large vacuum height, or a very oblique unit cell due to unconventional choice of primitive lattice vectors. It is expected that our displacement strategy can be used to address higher-order interatomic interactions to achieve good accuracy and efficiency

Boosting alternating decision trees modeling of disease trait information

We applied the alternating decision trees (ADTrees) method to the last 3 replicates from the Aipotu, Danacca, Karangar, and NYC populations in the Problem 2 simulated Genetic Analysis Workshop dataset. Using information from the 12 binary phenotypes and sex as input and Kofendrerd Personality Disorder disease status as the outcome of ADTrees-based classifiers, we obtained a new quantitative trait based on average prediction scores, which was then used for genome-wide quantitative trait linkage (QTL) analysis. ADTrees are machine learning methods that combine boosting and decision trees algorithms to generate smaller and easier-to-interpret classification rules. In this application, we compared four modeling strategies from the combinations of two boosting iterations (log or exponential loss functions) coupled with two choices of tree generation types (a full alternating decision tree or a classic boosting decision tree). These four different strategies were applied to the founders in each population to construct four classifiers, which were then applied to each study participant. To compute average prediction score for each subject with a specific trait profile, such a process was repeated with 10 runs of 10-fold cross validation, and standardized prediction scores obtained from the 10 runs were averaged and used in subsequent expectation-maximization Haseman-Elston QTL analyses (implemented in GENEHUNTER) with the approximate 900 SNPs in Hardy-Weinberg equilibrium provided for each population. Our QTL analyses on the basis of four models (a full alternating decision tree and a classic boosting decision tree paired with either log or exponential loss function) detected evidence for linkage (Z ≥ 1.96, p < 0.01) on chromosomes 1, 3, 5, and 9. Moreover, using average iteration and abundance scores for the 12 phenotypes and sex as their relevancy measurements, we found all relevant phenotypes for all four populations except phenotype b for the Karangar population, with suggested subgroup structure consistent with latent traits used in the model. In conclusion, our findings suggest that the ADTrees method may offer a more accurate representation of the disease status that allows for better detection of linkage evidence

Effects of short-term detraining on measures of obesity and glucose tolerance in elite athletes

[[abstract]]Athletes frequently adjust their training volume in line with their athletic competition schedule, onset of sport injury, and retirement. Whether maintenance of partial training activity during the detraining period can preserve optimal body composition and insulin sensitivity is currently unknown. Sixteen elite kayak athletes (mean (V) over dotO(2)max: 58.5 ml kg(-1) min(-1), s=1.77) were randomly assigned to a totally detrained group (age: 20.8 years, s=0.7; body mass index: 23.74, s=0.54) or partially detrained group (age: 21.8 years, s=0.7; body mass index: 23.20, s=1.02), whereby totally detrained participants terminated their training routine completely and the partially detrained participants preserved 50% of their previous training duration with equivalent intensity for one month. Body mass, waist circumference, oral glucose tolerance test, insulin, leptin, cortisol, and testosterone were measured during the trained state and after detraining. Waist circumferences for both the partially detrained and totally detrained groups were significantly elevated after detraining, with no group difference. However, body mass was reduced in both groups. Significant elevations in the area under the curve for insulin and fasted leptin with detraining were observed. These changes were greater in the totally detrained participants. In conclusion, the present results show that maintaining partial training activity cannot prevent an increase in waist circumference. During the detraining period, the magnitude of increase in plasma insulin and leptin concentrations was regulated in an activity-dependent manner

Three-Dimensional Magnetic Reconnection With a Spatially Confined X-Line Extent: Implications for Dipolarizing Flux Bundles and the Dawn-Dusk Asymmetry

Using 3‐D particle‐in‐cell simulations, we study magnetic reconnection with the X‐line being spatially confined in the current direction. We include thick current layers to prevent reconnection at two ends of a thin current sheet that has a thickness on an ion inertial (di) scale. The reconnection rate and outflow speed drop significantly when the extent of the thin current sheet in the current direction is urn:x-wiley:jgra:media:jgra54890:jgra54890-math-0001. When the thin current sheet extent is long enough, we find that it consists of two distinct regions; a suppressed reconnecting region (on the ion‐drifting side) exists adjacent to the active region where reconnection proceeds normally as in a 2‐D case with a typical fast rate value ≃0.1. The extent of this suppression region is ≃O(10di), and it suppresses reconnection when the thin current sheet extent is comparable or shorter. The time scale of current sheet thinning toward fast reconnection can be translated into the spatial scale of this suppression region, because electron drifts inside the ion diffusion region transport the reconnected magnetic flux, which drives outflows and furthers the current sheet thinning, away from this region. This is a consequence of the Hall effect in 3‐D. While the existence of this suppression region may explain the shortest possible azimuthal extent of dipolarizing flux bundles at Earth, it may also explain the dawn‐dusk asymmetry observed at the magnetotail of Mercury, which has a global dawn‐dusk extent much shorter than that of Earth.publishedVersio

A new method to assess spatial variations of outdoor thermal comfort: Onsite monitoring results and implications for precinct planning

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3D cell nuclei segmentation based on gradient flow tracking

<p>Abstract</p> <p>Background</p> <p>Reliable segmentation of cell nuclei from three dimensional (3D) microscopic images is an important task in many biological studies. We present a novel, fully automated method for the segmentation of cell nuclei from 3D microscopic images. It was designed specifically to segment nuclei in images where the nuclei are closely juxtaposed or touching each other. The segmentation approach has three stages: 1) a gradient diffusion procedure, 2) gradient flow tracking and grouping, and 3) local adaptive thresholding.</p> <p>Results</p> <p>Both qualitative and quantitative results on synthesized and original 3D images are provided to demonstrate the performance and generality of the proposed method. Both the over-segmentation and under-segmentation percentages of the proposed method are around 5%. The volume overlap, compared to expert manual segmentation, is consistently over 90%.</p> <p>Conclusion</p> <p>The proposed algorithm is able to segment closely juxtaposed or touching cell nuclei obtained from 3D microscopy imaging with reasonable accuracy.</p