2,541 research outputs found
Dependence of GCRs influx on the Solar North-South Asymmetry
We investigate the dependence of the amount of the observed galactic cosmic
ray (GCR) influx on the solar North-South asymmetry using the neutron count
rates obtained from four stations and sunspot data in archives spanning six
solar cycles from 1953 to 2008. We find that the observed GCR influxes at
Moscow, Kiel, Climax and Huancayo stations are more suppressed when the solar
activity in the southern hemisphere is dominant compared with when the solar
activity in the northern hemisphere is dominant. Its reduction rates at four
stations are all larger than those of the suppression due to other factors
including the solar polarity effect on the GCR influx. We perform the student's
t-test to see how significant these suppressions are. It is found that
suppressions due to the solar North-South asymmetry as well as the solar
polarity are significant and yet the suppressions associated with the former
are larger and more significant.Comment: 17 pages, 3figures, accepted to JAST
Detecting Leadership in Peer-moderated Online Collaborative Learning:Text Mining and Social Network Analysis for Learning Analytics
Effects of a video education program for patients with benign uterine tumors receiving high-intensity focused ultrasound treatment
Purpose The purpose of this study was to examine the effects of a video education program in women receiving high-intensity focused ultrasound (HIFU) treatment. Methods This was a quasi-experimental study with a nonequivalent control group non-synchronized design. The participants were 54 patients who had benign uterine tumors and adenomyosis. The data were collected from June to August 2018. A 10-minute video education program on HIFU and post-procedural care was developed based on the literature. The experimental group was provided the video education program with a question-and-answer session for 10 minutes after viewing the video. The control group received usual care (i.e., verbal instructions on post-procedural self-care). The questionnaire survey was conducted twice: before the educational program and before being discharged from the hospital. Differences in uncertainty, emotions, and self-efficacy among patients were analyzed. Data were analyzed using the chi-square test, Shapiro-Wilk test, paired t-test, and t-test with SPSS version 23.0. Results The participants in the experimental group showed a decrease in uncertainty(t=4.33, p<.001), improvements in anxiety(t=ā4.07, p<.001) and depression (t=ā3.55,p<.001), and an enhancement ofself-efficacy (t=ā4.39,p<.001) compared to the control group. Conclusion This nursing intervention was effective at reducing uncertainty, improving emotions, and enhancing self-efficacy. This intervention is feasible for use in nursing practice as an aid for patients when considering treatment methods
Development of a high yield purification process for the production of influenza virus vaccines
Production of influenza virus in animal cells has emerged as an alternative to conventional platforms such as egg-based production system. Animal cells, especially MDCK and VERO cell lines, are widely used as the primary production cell for influenza virus vaccine because of their high susceptibility to infection with various influenza viruses. Recently, a robust and reliable purification process was successfully developed for the production of quadri-valent HA proteins (from two strains of the type A virus and two strains of the type B virus) by using animal cell-based production system in Green Cross Corp., Korea. The UF/DF process, Benzonase treatment at high temperature as well as column chromatography strategy was optimized to maximize the final HA production yields. Benzonase treatment was conducted to reduce in hcDNA (host cell DNA) because hcDNA was main impurity for cell-based influenza virus vaccine. A simple and stable UF/DF process has been tested with membrane molecular weight cutoffs of 100 and 300 kDa as well as 0.2 and 0.45 um microfiltration membrane. Anion exchange chromatography (AEC) and size exclusion chromatography (SEC) were selected for acceptable reduction in hcDNA and HCP. AEC was used to separate hcDNA from virus at a salt concentration of 0.5 M sodium chloride. The HA yield through AEC & SEC combination process was sufficiently achieved under specific purification process condition. Overall, the amount of residual hcDNA was reduced to an acceptable level (10ng/dose) and the increased HA yield was maintained throughout the whole process. The performance, productivity and scalability of the purification process were successfully demonstrated in over 30 GMP batches using 4 different influenza virus strains
Real-Time Monitoring of Neural Differentiation of Human Mesenchymal Stem Cells by Electric Cell-Substrate Impedance Sensing
Stem cells are useful for cell replacement therapy. Stem cell differentiation must be monitored thoroughly and precisely prior to transplantation. In this study we evaluated the usefulness of electric cell-substrate impedance sensing (ECIS) for in vitro real-time monitoring of neural differentiation of human mesenchymal stem cells (hMSCs). We cultured hMSCs in neural
differentiation media (NDM) for 6 days and examined the time-course of impedance changes with an ECIS array. We also
monitored the expression of markers for neural differentiation, total cell count, and cell cycle profiles. Cellular expression of
neuron and oligodendrocyte markers increased. The resistance value of cells cultured in NDM was automatically measured in real-time
and found to increase much more slowly over time compared to cells cultured in non-differentiation media. The relatively slow
resistance changes observed in differentiating MSCs were determined to be due to their lower growth capacity achieved by
induction of cell cycle arrest in G0/G1. Overall results suggest that the relatively slow change in resistance values measured by
ECIS method can be used as a parameter for slowly growing neural-differentiating cells. However, to enhance the competence
of ECIS for in vitro real-time monitoring of neural differentiation of MSCs, more elaborate studies are needed
On the root cause of the host `mass-step' in the Hubble residuals of type Ia supernovae
It is well established that the Hubble residuals of type Ia supernovae (SNe
Ia) show the luminosity step with respect to their host galaxy stellar masses.
This `mass-step' is taken as an additional correction factor for the SN Ia
luminosity standardization. Here we investigate the root cause of the mass-step
and propose that the bimodal nature of the host distribution is
responsible for the step. In particular, by using the empirical
mass-to-age relation of local galaxies, we convert the mass function of SN Ia
hosts to their age distribution. We find that the age distribution shows clear
bimodality: a younger ( 6 Gyr) group with lower mass () and an older ( 6 Gyr) group with higher mass (). On the Hubble residual versus host mass plane,
the two groups create the mass-step at . This
leads us to conclude that the host galaxy mass-step can be attributed to the
bimodal age distribution in relation to a nonlinear relation between galaxy
mass and age. We suggest that the mass-step is another manifestation of the old
`red sequence' and the young `blue cloud' observed in the galactic
color--magnitude diagram.Comment: Accepted for publication in ApJ, 10 pages, 5 figures, 1 tabl
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