432 research outputs found
Structural Change in the Stock Market Efficiency after the Millennium: The MACD Approach
This paper studies the profitability of the Moving Average Convergence-Divergence (MACD) trading rule under three different crossing rules: the MACD zero line, the 9-day and 14-day signal lines. It is found that the trading rules perform well in the stock markets of Germany and Hong Kong. Our research also shows that generally the major stock markets around the world have become more efficient after the millennium.
On the exactness of soft theorems
Soft behaviours of S-matrix for massless theories reflect the underlying
symmetry principle that enforces its masslessness. As an expansion in soft
momenta, sub-leading soft theorems can arise either due to (I) unique structure
of the fundamental vertex or (II) presence of enhanced broken-symmetries. While
the former is expected to be modified by infrared or ultraviolet divergences,
the latter should remain exact to all orders in perturbation theory. Using
current algebra, we clarify such distinction for spontaneously broken (super)
Poincar\'e and (super) conformal symmetry. We compute the UV divergences of
DBI, conformal DBI, and A-V theory to verify the exactness of type (II) soft
theorems, while type (I) are shown to be broken and the soft-modifying
higher-dimensional operators are identified. As further evidence for the
exactness of type (II) soft theorems, we consider the alpha' expansion of both
super and bosonic open strings amplitudes, and verify the validity of the
translation symmetry breaking soft-theorems up to O(alpha'^6). Thus the
massless S-matrix of string theory "knows" about the presence of D-branes.Comment: 35 pages. Additional mathematica note book with the UV-divergenece of
the 6-point amplitude in AV/KS theor
Bulk locality from the celestial amplitude
In this paper, we study the implications of bulk locality on the celestial
amplitude. In the context of the four-point amplitude, the fact that the bulk
S-matrix factorizes locally in poles of Mandelstam variables is reflected in
the imaginary part of the celestial amplitude. In particular, on the real axis
in the complex plane of the boost weight, the imaginary part of the celestial
amplitude can be given as a positive expansion on the Poincar\'e partial waves,
which are nothing but the projection of flat-space spinning polynomials onto
the celestial sphere. Furthermore, we derive the celestial dispersion relation,
which relates the imaginary part to the residue of the celestial amplitude for
negative even integer boost weight. The latter is precisely the projection of
low energy EFT coefficients onto the celestial sphere. We demonstrate these
properties explicitly on the open and closed string celestial amplitudes.
Finally, we give an explicit expansion of the Poincar\'e partial waves in terms
of 2D conformal partial waves.Comment: 43 pages, 10 figures. v2: typos corrected, minor clarifications
added, SciPost published versio
5-ALA mediated photodynamic therapy induces autophagic cell death via AMP-activated protein kinase
Photodynamic therapy (PDT) has been developed as an anticancer treatment, which is based on the tumor-specific accumulation of a photosensitizer that induces cell death after irradiation of light with a specific wavelength. Depending on the subcellular localization of the photosensitizer, PDT could trigger various signal transduction cascades and induce cell death such as apoptosis, autophagy, and necrosis. In this study, we report that both AMP-activated protein kinase (AMPK) and mitogen-activated protein kinase (MAPK) signaling cascades are activated following 5-aminolevulinic acid (ALA)-mediated PDT in both PC12 and CL1-0 cells. Although the activities of caspase-9 and -3 are elevated, the caspase inhibitor zVAD-fmk did not protect cells against ALA-PDT-induced cell death. Instead, autophagic cell death was found in PC12 and CL1-0 cells treated with ALA-PDT. Most importantly, we report here for the first time that it is the activation of AMPK, but not MAPKs that plays a crucial role in mediating autophagic cell death induced by ALA-PDT. This novel observation indicates that the AMPK pathway play an important role in ALA-PDT-induced autophagy
PAH–DNA Adducts in Cord Blood and Fetal and Child Development in a Chinese Cohort
Polycyclic aromatic hydrocarbons (PAHs) are an important class of toxic pollutants released by fossil fuel combustion. Other pollutants include metals and particulate matter. PAH–DNA adducts, or benzo[a]pyrene (BaP) adducts as their proxy, provide a chemical-specific measure of individual biologically effective doses that have been associated with increased risk of cancer and adverse birth outcomes. In the present study we examined the relationship between prenatal PAH exposure and fetal and child growth and development in Tongliang, China, where a seasonally operated coal-fired power plant was the major pollution source. In a cohort of 150 nonsmoking women and their newborns enrolled between 4 March 2002 and 19 June 2002, BaP–DNA adducts were measured in maternal and umbilical cord blood obtained at delivery. The number of gestational months occurring during the period of power plant operation provided a second, more general measure of exposure to plant emissions, in terms of duration. High PAH–DNA adduct levels (above the median of detectable adduct level) were associated with decreased birth head circumference (p = 0.057) and reduced children’s weight at 18 months, 24 months, and 30 months of age (p < 0.05), after controlling for potential confounders. In addition, in separate models, longer duration of prenatal exposure was associated with reduced birth length (p = 0.033) and reduced children’s height at 18 (p = 0.001), 24 (p < 0.001), and 30 months of age (p < 0.001). The findings suggest that exposure to elevated levels of PAHs, with the Tongliang power plant being a significant source, is associated with reduced fetal and child growth in this population
Genome-Wide association Study of Serum Metabolites in the african american Study of Kidney Disease and Hypertension
The genome-wide association study (GWAS) is a powerful means to study genetic determinants of disease traits and generate insights into disease pathophysiology. to date, few GWAS of circulating metabolite levels have been performed in African Americans with chronic kidney disease. Hypothesizing that novel genetic-metabolite associations may be identified in a unique population of African Americans with a lower glomerular filtration rate (GFR), we conducted a GWAS of 652 serum metabolites in 619 participants (mean measured glomerular filtration rate 45 mL/min/1.73
Intermittent Hypoxia Exposure Helps to Restore the Reduced Hemoglobin Concentration During Intense Exercise Training in Trained Swimmers
In prolonged intense exercise training, the training load of athletes may be reduced once their hemoglobin concentrations ([Hb]s) are decreased dramatically. We previously reported that intermittent hypoxia exposure (IHE) could be used to alleviate the decrease of [Hb] and help to maintain the training load in rats. To further explore the feasibility of applying IHE intervention to athletes during prolonged intense exercise training, 6 trained swimmers were recruited to conduct a 4-week IHE intervention at the intervals after their [Hb] dropped for 10% or more during their training season. IHE intervention lasted 1 h and took place once a day and five times a week. Hematological and hormonal parameters, including [Hb], red blood cells (RBC), hematocrit (Hct), reticulocytes, serum erythropoietin (EPO), testosterone (T) and cortisol (C) were examined. After the IHE intervention was launched, [Hb], RBC and Hct of the subjects were increased progressively with their maximum levels (P < 0.01) showing at the third or fourth week, respectively. An increase in reticulocyte count (P < 0.01) suggests that IHE intervention promotes erythropoiesis to increase [Hb]. Besides, serum level of EPO, the hormone known to stimulate erythropoiesis, was overall higher than that before the IHE intervention, although it was statistically insignificant. Furthermore, the serum level of T, another hormone known to stimulate erythropoiesis, was increased progressively with the maximum level showing at the fourth week. Collectively, this study further confirms that IHE intervention may be used as a new strategy to prevent intense exercise training-induced reductions in [Hb]
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