870 research outputs found
Profitability of contrarian strategies in the Chinese stock market
This paper reexamines the profitability of loser, winner and contrarian
portfolios in the Chinese stock market using monthly data of all stocks traded
on the Shanghai Stock Exchange and Shenzhen Stock Exchange covering the period
from January 1997 to December 2012. We find evidence of short-term and
long-term contrarian profitability in the whole sample period when the
estimation and holding horizons are 1 month or longer than 12 months and the
annualized returns of contrarian portfolios increases with the estimation and
holding horizons. We perform subperiod analysis and find that the long-term
contrarian effect is significant in both bullish and bearish states while the
short-term contrarian effect disappears in bullish states. We compare the
performance of contrarian portfolios based on different grouping manners in the
estimation period and unveil that decile grouping outperforms quintile grouping
and tertile grouping, which is more evident and robust in the long run.
Generally, loser portfolios and winner portfolios have positive returns and
loser portfolios perform much better than winner portfolios. Both loser and
winner portfolios in bullish states perform better than those in the whole
sample period. In contrast, loser and winner portfolios have smaller returns in
bearish states in which loser portfolio returns are significant only in the
long term and winner portfolio returns become insignificant. These results are
robust to the one-month skipping between the estimation and holding periods and
for the two stock exchanges. Our findings show that the Chinese stock market is
not efficient in the weak form. These findings also have obvious practical
implications for financial practitioners.Comment: 24 pages (including 4 figures and 9 tables) + 5 supplementary figures
+ 10 supplementary table
Time-varying return predictability in the Chinese stock market
China's stock market is the largest emerging market all over the world. It is
widely accepted that the Chinese stock market is far from efficiency and it
possesses possible linear and nonlinear dependence. We study the predictability
of returns in the Chinese stock market by employing the wild bootstrap
automatic variance ratio test and the generalized spectral test. We find that
the return predictability vary over time and significant return predictability
is observed around market turmoils. Our findings are consistent with the
Adaptive Markets Hypothesis and have practical implications for market
participants.Comment: 11 Latex pages including 2 figures and 1 tabl
N′-Diphenylmethylene-2-hydroxybenzohydrazide
The title compound, C20H16N2O2, was synthesized by the reaction of 2-hydroxybenzohydrazide with diphenylmethanone. The dihedral angle between the phenyl rings is 76.28 (11)°. The amino H atom is involved in an intramolecular N—H⋯O hydrogen bond. In the crystal structure, the hydroxy groups and carbonyl O atoms form intermolecular O—H⋯O hydrogen bonds, which link the molecules into chains running along the b axis
Phylogenomic reconstruction of lactic acid bacteria: an update
<p>Abstract</p> <p>Background</p> <p>Lactic acid bacteria (LAB) are important in the food industry for the production of fermented food products and in human health as commensals in the gut. However, the phylogenetic relationships among LAB species remain under intensive debate owing to disagreements among different data sets.</p> <p>Results</p> <p>We performed a phylogenetic analysis of LAB species based on 232 genes from 28 LAB genome sequences. Regardless of the tree-building methods used, combined analyses yielded an identical, well-resolved tree topology with strong supports for all nodes. The LAB species examined were divided into two groups. Group 1 included families Enterococcaceae and Streptococcaceae. Group 2 included families Lactobacillaceae and Leuconostocaceae. Within Group 2, the LAB species were divided into two clades. One clade comprised of the acidophilus complex of genus <it>Lactobacillus </it>and two other species, <it>Lb. sakei </it>and <it>Lb. casei</it>. In the acidophilus complex, <it>Lb. delbrueckii </it>separated first, while <it>Lb. acidophilus</it>/<it>Lb. helveticus </it>and <it>Lb. gasseri</it>/<it>Lb. johnsonii </it>were clustered into a sister group. The other clade within Group 2 consisted of the salivarius subgroup, including five species, <it>Lb. salivarius</it>, <it>Lb. plantarum</it>, <it>Lb. brevis</it>, <it>Lb. reuteri</it>, <it>Lb. fermentum</it>, and the genera <it>Pediococcus, Oenococcus</it>, and <it>Leuconostoc</it>. In this clade, <it>Lb. salivarius </it>was positioned most basally, followed by two clusters, one corresponding to <it>Lb. plantarum</it>/<it>Lb. brevis </it>pair and <it>Pediococcus</it>, and the other including <it>Oenococcus</it>/<it>Leuconostoc </it>pair and <it>Lb. reuteri</it>/<it>Lb. fermentum </it>pair. In addition, phylogenetic utility of the 232 genes was analyzed to identify those that may be more useful than others. The genes identified as useful were related to translation and ribosomal structure and biogenesis (TRSB), and a three-gene set comprising genes encoding ultra-violet resistance protein B (<it>uvrB</it>), DNA polymerase III (<it>polC</it>) and penicillin binding protein 2B (<it>pbpB</it>).</p> <p>Conclusions</p> <p>Our phylogenomic analyses provide important insights into the evolution and diversification of LAB species, and also revealed the phylogenetic utility of several genes. We infer that the occurrence of multiple, independent adaptation events in LAB species, have resulted in their occupation of various habitats. Further analyses of more genes from additional, representative LAB species are needed to reveal the molecular mechanisms underlying adaptation of LAB species to various environmental niches.</p
2-(1H-1,2,3-Benzotriazol-1-yl)-N′-(2-chlorobenzylidene)acetohydrazide
In the title compound, C15H12ClN5O, the mean planes of the benzotriazole and chlorophenyl fragments form a dihedral angle of 70.8 (1)°. In the crystal, molecules are linked into infinite chains along the a axis by N—H⋯O hydrogen bonds. Weak intermolecular C—H⋯N hydrogen bonds further link these chains into layers parallel to the ab plane. The crystal studied was a racemic twin
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