1,087 research outputs found
XeCl laser pumped iodine laser using t-C4F9I
An iodine photodissociation laser using t-C4F9I as the active material was pumped by an XeCl laser. An iodine laser output energy of 3 mJ with pulse duration of 25 ns was obtained when the pumping pulse energy was 80 mJ, the iodide pressure was 70 torr, and the reflectance of the output mirror was 85 percent. The high pumping efficiency and low threshold pump power achieved in this experiment are attributable to the high absorption cross section at the pump laser wavelength (308 nm) of the iodide used
Direct solar-pumped iodine laser amplifier
The optimum conditions of a solar pumped iodine laser are found in this research for the case of a continuous wave operation and a pulsed operation. The optimum product of the pressure(p) inside the laser tube and the tube diameter(d) was pd=40 approx. 50 torr-cm on the contrary to the case of a high intensity flashlamp pumped iodine laser where the optimum value of the product is known to be pd=150 torr-cm. The pressure-diameter product is less than 1/3 of that of the high power iodine laser. During the research period, various laser materials were also studied for solar pumping. Among the laser materials, Nd:YAG is found to have the lowest laser threshold pumping intensity of about 200 solar constant. The Rhodamine 6G was also tested as the solar pumped laser material. The threshold pumping power was measured to be about 20,000 solar constant. The amplification experiment for a continuously pumped iodine laser amplifier was performed using Vortek solar simulator and the amplification factors were measured for single pass amplification and triple pass amplification of the 15 cm long amplifier tube. The amplification of 5 was obtained for the triple pass amplification
2D Bayesian automated tilted-ring fitting of disk galaxies in large HI galaxy surveys: 2DBAT
We present a novel algorithm based on a Bayesian method for 2D tilted-ring
analysis of disk galaxy velocity fields. Compared to the conventional
algorithms based on a chi-squared minimisation procedure, this new
Bayesian-based algorithm suffers less from local minima of the model parameters
even with highly multi-modal posterior distributions. Moreover, the Bayesian
analysis, implemented via Markov Chain Monte Carlo (MCMC) sampling, only
requires broad ranges of posterior distributions of the parameters, which makes
the fitting procedure fully automated. This feature will be essential when
performing kinematic analysis on the large number of resolved galaxies expected
to be detected in neutral hydrogen (HI) surveys with the Square Kilometre Array
(SKA) and its pathfinders. The so-called '2D Bayesian Automated Tilted-ring
fitter' (2DBAT) implements Bayesian fits of 2D tilted-ring models in order to
derive rotation curves of galaxies. We explore 2DBAT performance on (a)
artificial HI data cubes built based on representative rotation curves of
intermediate-mass and massive spiral galaxies, and (b) Australia Telescope
Compact Array (ATCA) HI data from the Local Volume HI Survey (LVHIS). We find
that 2DBAT works best for well-resolved galaxies with intermediate inclinations
(20 deg < i < 70 deg), complementing three-dimensional techniques better suited
to modelling inclined galaxies.Comment: Accepted for publication in MNRAS; 46 pages, 33 figure
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Histamine and Histamine H4 Receptor Promotes Osteoclastogenesis in Rheumatoid Arthritis.
Histamine H4 receptor (H4R) has immune-modulatory and chemotaxic effects in various immune cells. This study aimed to determine the osteoclastogenic role of H4R in rheumatoid arthritis (RA). The concentration of histamine in synovial fluid (SF) and sera in patients with RA was measured using ELISA. After RA SF and peripheral blood (PB) CD14+ monocytes were treated with histamine, IL-17, IL-21 and IL-22, and a H4R antagonist (JNJ7777120), the gene expression H4R and RANKL was determined by real-time PCR. Osteoclastogenesis was assessed by counting TRAP-positive multinucleated cells in PB CD14+ monocytes cultured with histamine, Th17 cytokines and JNJ7777120. SF and serum concentration of histamine was higher in RA, compared with osteoarthritis and healthy controls. The expression of H4R was increased in PB monocytes in RA patients. Histamine, IL-6, IL-17, IL-21 and IL-22 induced the expression of H4R in monocytes. Histamine, IL-17, and IL-22 stimulated RANKL expression in RA monocytes and JNJ7777120 reduced the RANKL expression. Histamine and Th17 cytokines induced the osteoclast differentiation from monocytes and JNJ7777120 decreased the osteoclastogenesis. H4R mediates RANKL expression and osteoclast differentiation induced by histamine and Th17 cytokines. The blockage of H4R could be a new therapeutic modality for prevention of bone destruction in RA
An HI study of the collisional ring galaxy NGC 922
We present new atomic hydrogen (HI) observations of the collisional ring
galaxy NGC 922 obtained using the Australia Telescope Compact Array. Our
observations reveal for the first time the vast extent of the HI disc of this
galaxy. The HI morphology and kinematics of NGC 922 show that this galaxy is
not the product of a simple drop-through interaction, but has a more complex
interaction history. The integrated HI flux density of NGC 922 from our
observations is 24.7 Jy km s, which is within the error of the flux
value obtained using the -m Parkes radio telescope. This flux density
translates to a total HI mass of M and corresponds to
an HI to total mass fraction (M/M) of approximately . The
gaseous structures of NGC 922 are more extended to the north and include an HI
tail that has a projected physical length of kpc. Gas warps are also
evident in the velocity field of NGC 922 and are more prominent on the
approaching and the western side of the disc. In comparison with a large sample
of star-forming galaxies in the local Universe, NGC 922 possesses a high gas
fraction relative to galaxies with a similar stellar mass of ~
M, and exhibits a high specific star formation rate.Comment: 11 pages, 8 figures, published in MNRA
Latent transforming growth factor β-binding protein-3 and fibulin-1C interact with the extracellular domain of the heparin-binding EGF-like growth factor precursor
BACKGROUND: The membrane-bound cell-surface precursor and soluble forms of heparin-binding epidermal growth factor-like growth factor (HB-EGF) contribute to many cellular developmental processes. The widespread occurrence of HB-EGF in cell and tissue types has led to observations of its role in such cellular and tissue events as tumor formation, cell migration, extracellular matrix formation, wound healing, and cell adherence. Several studies have reported the involvement of such extracellular matrix proteins as latent transforming growth factor β-binding protein, TGF-β, and fibulin-1 in some of these processes. To determine whether HB-EGF interacts with extracellular matrix proteins we used the extracellular domain of proHB-EGF in a yeast two-hybrid system to screen a monkey kidney cDNA library. cDNA clones containing nucleotide sequences encoding domains of two proteins were obtained and their derived amino acid sequences were evaluated. RESULTS: From ≈ 3 × 10(6) screened monkey cDNA clones, cDNA clones were recovered that contained nucleotide sequences encoding domains of the monkey latent transforming growth factor-β binding protein-3 (MkLTBP-3) and fibulin-1C protein. The amino acid sequence derived from the MkLTBP-3 gene shared 98.6% identity with human LTBP-3 and 86.7% identity with mouse LTBP-3 amino acid sequences. The amino acid sequence derived from the monkey fibulin-1C gene shared 97.2% identity with human fibulin-1C. Yeast two-hybrid screens indicate that LTBP-3 and fibulin-1C interact with proHB-EGF through their calcium-binding EGF-like modules. CONCLUSIONS: The interactions of the extracellular domain of proHB-EGF with LTBP-3 and fibulin-1C suggest novel functions for HB-EGF between cell and tissue surfaces
Measuring and Controlling Social Desirability Bias: Applications in Information Systems Research
Despite the potential risks that social desirability (SD) bias poses to the validity of information systems (IS) research, little is known about the extent of such bias. This study examines the extent of SD bias in the IS domain and compares alternative techniques for measuring it. Our findings suggest that despite the popularity of the Marlowe-Crowne scale in IS research, the impression management scale functions better in assessing the extent of SD bias. We also found that under certain circumstances, SD bias can threaten the validity of IS research. This study contributes to the IS literature by showing the difference in SD bias across IS contexts and suggesting an effective way to test for the presence of SD bias
How to Achieve Goals in Digital Games: An Empirical Test of a Goal-Oriented Model in Pokemon GO
To effectively design digital games and gamified systems, it is important to properly understand the psychological and behavioral processes that players use to reach goals. Although numerous prior studies have examined individual adoption, use, and continued use of digital games, few attempts have been made to understand how people desire and strive to achieve goals. The objective of this study is to develop and test a model of individual achievement of goals in digital gaming. Drawing upon theories of goal-directed behavior, we propose a conceptual model describing goal setting, goal striving, goal attainment, and feedback evaluations in the context of mobile gaming. To empirically test the proposed model, we collected two sets of (cross-sectional and longitudinal) data from 407 users of Pokemon GO. The results generally indicate that goal-directed effort plays an important role in translating goal desire into goal attainment. In addition, we found prior game points and goal desire have interaction effects on goal-directed effort and the subsequent acquisition of game points. Finally, this study shows that action strategies such as in-game payment and deliberate planning have differential effects on goal-directed effort and satisfying experiences. Overall, our findings provide empirical support for the efficacy of our goal-oriented model as a theoretical tool for explaining the process of goal striving to obtain game points. Our findings not only have important implications for digital gaming but also contribute to emerging research on gamified systems
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