3,949 research outputs found
K*{\Lambda}(1116) photoproduction and nucleon resonances
In this presentation, we report our recent studies on the
photoproduction off the proton target, using the tree-level Born approximation,
via the effective Lagrangian approach. In addition, we include the nine (three-
or four-star confirmed) nucleon resonances below the threshold
MeV, to interpret the discrepancy between the
experiment and previous theoretical studies, in the vicinity of the threshold
region. From the numerical studies, we observe that the and
play an important role for the cross-section enhancement near
the . It also turns out that, in order to reproduce the
data, we have the vector coupling constants
and
.Comment: 2 pages, 2 figures, talk given at International Conference on the
structure of baryons, BARYONS'10, Dec. 7-11, 2010, Osaka, Japa
Developmental trajectories of tobacco use and risk factors from adolescence to emerging young adulthood: a population-based panel study
Abstract
Background
Adolescence to young adulthood is a critical developmental period that determines lifelong patterns of tobacco use. We examined the longitudinal trajectories of tobacco use, and risk factors for its use, and explored the association between the trajectories of mobile phone dependency and smoking throughout the life-course among adolescents and young adults.
Methods
Data of 1,723 subjects (853 boys and 870 girls) were obtained from six waves of the Korean Children and Youth Panel Survey (mean age = 13.9–19.9years). To identify trajectories of smoking and mobile phone dependency, group-based trajectory modelling (GBTM) was conducted. A multinomial logistic regression analysis was performed to identify the characteristics of the trajectory groups.
Results
GBTM identified four distinct smoking trajectories: never smokers (69.1%), persistent light smokers (8.7%), early established smokers (12.0%), and late escalators (10.3%). Successful school adjustment decreased the risk of being an early established smoker (odds ratio [OR] 0.46, 95% confidence interval [CI] 0.27–0.78). The number of days not supervised by a guardian after school was positively associated with the risk of being an early established smoker (OR 1.96, 95% CI 1.23–3.13). Dependency on mobile phones throughout the life-course was positively associated with the risk of being a persistent light smoker (OR 4.04, 95% CI 1.32–12.34) or early established smoker (OR 8.18, 95% CI 4.04–16.56).
Conclusions
Based on the group-based modeling approach, we identified four distinctive smoking trajectories and highlight the long-term effects of mobile phone dependency, from early adolescence to young adulthood, on smoking patterns
β-catenin activation down-regulates cell-cell junction-related genes and induces epithelial-to-mesenchymal transition in colorectal cancers
WNT signaling activation in colorectal cancers (CRCs) occurs through APC inactivation or β-catenin mutations. Both processes promote β-catenin nuclear accumulation, which up-regulates epithelial-to-mesenchymal transition (EMT). We investigated β-catenin localization, transcriptome, and phenotypic differences of HCT116 cells containing a wild-type (HCT116-WT) or mutant β-catenin allele (HCT116-MT), or parental cells with both WT and mutant alleles (HCT116-P). We then analyzed β-catenin expression and associated phenotypes in CRC tissues. Wild-type β-catenin showed membranous localization, whereas mutant showed nuclear localization; both nuclear and non-nuclear localization were observed in HCT116-P. Microarray analysis revealed down-regulation of Claudin-7 and E-cadherin in HCT116-MT vs. HCT116-WT. Claudin-7 was also down-regulated in HCT116-P vs. HCT116-WT without E-cadherin dysregulation. We found that ZEB1 is a critical EMT factor for mutant β-catenin-mediated loss of E-cadherin and Claudin-7 in HCT116-P and HCT116-MT cells. We also demonstrated that E-cadherin binds to both WT and mutant β-catenin, and loss of E-cadherin releases β-catenin from the cell membrane and leads to its degradation. Alteration of Claudin-7, as well as both Claudin-7 and E-cadherin respectively caused tight junction (TJ) impairment in HCT116-P, and dual loss of TJs and adherens junctions (AJs) in HCT116-MT. TJ loss increased cell motility, and subsequent AJ loss further up-regulated that. Immunohistochemistry analysis of 101 CRCs revealed high (14.9%), low (52.5%), and undetectable (32.6%) β-catenin nuclear expression, and high β-catenin nuclear expression was significantly correlated with overall survival of CRC patients (P = 0.009). Our findings suggest that β-catenin activation induces EMT progression by modifying cell-cell junctions, and thereby contributes to CRC aggressiveness
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Validation of Submaximal Step Tests and the 6-Min Walk Test for Predicting Maximal Oxygen Consumption in Young and Healthy Participants.
Background: This study aimed to test the validity of three different submaximal tests (i.e., 3-min step test with 20.3-cm step box height (3MST20), 3-min step test with 30-cm step box height (3MST30), and 6-min walk test (6MWT)) in estimating maximal oxygen consumption (VO2max) in young and healthy individuals. Methods: The 3MST20, 3MST30, 6MWT, as well as the cardiopulmonary exercise test (CPET) were performed in 73 participants (37 men and 36 women; mean age: 30.8 ± 9.3 years). All participants visited the clinic three times in a random order for anthropometric measurements, three submaximal tests, and the VO2max test. Multiple linear regression analyses were conducted to construct the VO2max prediction equations for each submaximal test. Results: The prediction equations developed based on multiple regression analyses for each submaximal tests were as follows: 3MST20: VO2max = 86.0 - 10.9 × sex (male = 1, female = 2) - 0.4 × age - 0.1 × weight - 0.1 × heart rate recovery at 30 s (HRR30s); 3MST30: VO2max = 84.5 - 10.2 × sex (male = 1, female = 2) - 0.4 × age - 0.1 × weight - 0.1 × HRR30s; and 6MWT: VO2max = 61.1 - 11.1 × sex (male = 1, female = 2) - 0.4 × age - 0.2 × weight - 0.2 × (distance walked·10-1). The estimated VO2max values based on formulated equations were 37.0 ± 7.9, 37.3 ± 7.6, and 36.9 ± 7.9 mL∙kg-1∙min-1 derived from the 3MST20, 3MST30, and 6MWT, respectively. These estimated VO2max values were not significantly different from the measured VO2max value, 37.3 mL∙kg-1∙min-1. The estimated VO2max based on the 3MST20, 3MST30, and 6MWT results explained 73.4%, 72.2%, and 74.4% of the variances in the measured VO2max (p < 0.001), respectively. Conclusions: The 3MST20, 3MST30, and 6MWT were valid in estimating VO2max in relatively young and healthy Asian individuals
30 inch Roll-Based Production of High-Quality Graphene Films for Flexible Transparent Electrodes
We report that 30-inch scale multiple roll-to-roll transfer and wet chemical
doping considerably enhance the electrical properties of the graphene films
grown on roll-type Cu substrates by chemical vapor deposition. The resulting
graphene films shows a sheet resistance as low as ~30 Ohm/sq at ~90 %
transparency which is superior to commercial transparent electrodes such as
indium tin oxides (ITO). The monolayer of graphene shows sheet resistances as
low as ~125 Ohm/sq with 97.4% optical transmittance and half-integer quantum
Hall effect, indicating the high-quality of these graphene films. As a
practical application, we also fabricated a touch screen panel device based on
the graphene transparent electrodes, showing extraordinary mechanical and
electrical performances
Capillary force lithography with impermeable molds
Capillary force lithography (CFL) with impermeable mold is presented. For the CFL to be operative over large area, either the mold or the substrate has to be flexible. With a silicon wafer mold and a flexible substrate, a repeated line and space pattern with a spacing of 30 nm is shown to be well patterned. With a flexible mold and a hard substrate, a similar pattern with a spacing of 60 nm is demonstrated by CFL. The flexibility is needed for the intimate contact that is required between the mold and the substrate for the capillarity to take hold over large area. The forte of CFL with impermeable mold lies in the fact that the driving force for the patterning, which is capillary force, increases with decreasing pattern size.This work was supported by the Korea Foundation Grant funded by MOEHRD (KRF-2005-041-D00250)
Round Cell Variant of Myxoid Liposarcoma in a Japanese Macaque (Macaca fuscata)
A 5-year-old, female, Japanese Macaque (Macaca fuscata) was diagnosed with round cell variant of myxoid liposarcoma. At necropsy, multifocal to coalescing, reddish tan to white nodules, ranging from 0.5 to 1 cm in diameter, were noted throughout the omentum and retroperitoneum. Similar neoplastic nodules were also present in diaphragm, abdominal wall, and on hepatic capsule. Microscopically, neoplastic masses consisted of round to polyhedral cells, which had round, often eccentric nuclei and abundant eosinophilic granular and microvacuolated cytoplasm; Oil red O staining demonstrated large numbers of lipid droplets in the cytoplasm. Ultrastructurally, the cytoplasm of the tumor cells was packed with occasional lipid vacuoles and numerous enlarged mitochondria. Immunohistochemistry revealed tumor cells were positive for vimentin, while negative to cytokeratin, actin, and Factor VIII–related antigen. To the authors' knowledge, this is the first report of round-cell variant of myxoid liposarcoma in nonhuman primate.This study was supported through Brain Korea 21
Program for Veterinary Science
Fractal Profit Landscape of the Stock Market
We investigate the structure of the profit landscape obtained from the most
basic, fluctuation based, trading strategy applied for the daily stock price
data. The strategy is parameterized by only two variables, p and q. Stocks are
sold and bought if the log return is bigger than p and less than -q,
respectively. Repetition of this simple strategy for a long time gives the
profit defined in the underlying two-dimensional parameter space of p and q. It
is revealed that the local maxima in the profit landscape are spread in the
form of a fractal structure. The fractal structure implies that successful
strategies are not localized to any region of the profit landscape and are
neither spaced evenly throughout the profit landscape, which makes the
optimization notoriously hard and hypersensitive for partial or limited
information. The concrete implication of this property is demonstrated by
showing that optimization of one stock for future values or other stocks
renders worse profit than a strategy that ignores fluctuations, i.e., a
long-term buy-and-hold strategy.Comment: 12 pages, 4 figure
Proposal to produce long-lived mesoscopic superpositions through an atom-driven field interaction
We present a proposal for the production of longer-lived mesoscopic
superpositions which relies on two requirements: parametric amplification and
squeezed vacuum reservoir for cavity-field states. Our proposal involves the
interaction of a two-level atom with a cavity field which is simultaneously
subjected to amplification processes.Comment: 12 pages, title changed, text improved and refences adde
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