FORMULATION AND CONSTRAINTS ON LATE DECAYING DARK MATTER

LAN, NGUYEN Q.,VINH, NGUYEN A.,MATHEWS, GRANT J. The Korean Astronomical Society 2015 天文學論叢 Vol.30 No.2

We consider a late decaying dark matter model in which cold dark matter begins to decay into relativistic particles at a recent epoch ($z{\leqslant}1$). A complete set of Boltzmann equations for dark matter and other relevant particles particles is derived, which is necessary to calculate the evolution of the energy density and density perturbations. We show that the large entropy production and associated bulk viscosity from such decays leads to a recently accelerating cosmology consistent with observations. We determine the constraints on the decaying dark matter model with bulk viscosity by using a MCMC method combined with observational data of the CMB and type Ia supernovae.

Effect of Process Parameters on Mechanical Strength of Fabricated Parts using the Fused Deposition Modelling Method

Lan P. T. Huynh,Huy A. Nguyen,Huy Q. Nguyen,Loc K. H. Phan,Thanh T. Tran 한국정밀공학회 2019 한국정밀공학회지 Vol.36 No.8

This study investigated the effects of process parameters on mechanical properties of fabricated parts of the Polylactic acid (PLA) materials using fused deposition modeling (FDM) in 3D printing Technology. First, Taguchi method in the design of experiment (DOE) approach was applied to generate a design matrix of three process parameters namely; printing speed, extrusion temperature and layer thickness. A L9 array with 9 specimens was used for fabrication under various process parameters by the Builder 3D printer. Tensile test was implemented and recorded in accordance with ASTM D368 standard. Achieved data were analyzed using the Minitab software to show the effect of each process parameter on mechanical properties. Secondly, a regression model was developed to predict the trend of response in case of change in setting of parameters and estimating the optimal set of process parameters which creates the strongest FDM parts. The achieved optimum parameters were used to validate the fabricated samples for tensile testing. According to the results, the best mechanical strength of fabricated parts was achieved with printing speed of 48 mm/s, extrusion temperature of 220 degree of celsius (C) and the layer thickness of 0.15 mm. Also, the extrusion temperature was the most influencing factor on ultimate tensile stress.

Association Analyses with Carcass Traits in the Porcine KIAA1717 and HUMMLC2B Genes

Xu, D.Q.,Xiong, Y.Z.,Liu, M.,Lan, J.,Ling, X.F.,Deng, C.Y.,Jiang, S.W. Asian Australasian Association of Animal Productio 2005 Animal Bioscience Vol.18 No.11

By screening a subtracted cDNA library constructed with mRNA obtained from the longissimus dorsi muscles of F1 hybrids Landrace${\times}$Yorkshire and their Yorkshire female parents, we isolated two partial sequences coding for the H3-K4-specific methyltransferase (KIAA1717) and skeletal muscle myosin regulatory light chain (HUMMLC2B) genes. In the present work we investigated two SNPs, one (C1354T) at the 3' untranslated region (UTR) of KIAA1717 and one (A345G) at the SINE (PRE-1) element of HUMMLC2B, in a resource population derived from crossing Chinese Meishan and Large White pig. The selected pigs were genotyped by means of a PCR-RFLP protocol. Significant associations were observed for the KIAA1717 C1354T polymorphic site with thorax-waist backfat thickness (p<0.05), buttock backfat thickness (p<0.05), average backfat thickness (p<0.05), loin eye height (p<0.05), loin eye area (p<0.05), carcass length to 1$^{st}$ spondyle (p<0.01) and carcass length to 1st rib (p<0.01). HUMMLC2B A345G were significantly associated with loin eye width (p<0.05), loin eye area (p<0.05). Further studies are needed to confirm these preliminary results.

Effects of CSN1S2 Genotypes on Economic Traits in Chinese Dairy Goats

Yue, X.P.,Fang, Q.,Zhang, X.,Mao, C.C.,Lan, X.Y.,Chen, H.,Lei, Chuzhao Asian Australasian Association of Animal Productio 2013 Animal Bioscience Vol.26 No.7

The aim of this study was to investigate allele frequencies at the CSN1S2 locus in two Chinese dairy goat breeds and the effects of its variation on dairy goat economic traits. Seven hundred and eight goats from Xinong Saanen (XS, n = 268) and Guanzhong (GZ, N = 440) breeds were selected. The milk samples of 268 XS goats were collected during the middle of lactation, body size parameters (708 goats) and daily milk yield (202 goats) were registered. The RFLP (restriction fragment length polymorphism) and SSCP (single strand conformation polymorphism) were used to detect the polymorphisms in CSN1S2. The Hardy-Weinberg (HW) equilibrium and the associations between body size, milk yield and composition and the genotypes were calculated. The results revealed that only A and F CSN1S2 alleles were found in the two Chinese dairy goat breeds. Allelic frequencies of A and F were 0.795, 0.205 and 0.739, 0.261 in Xinong Saanen and Guanzhong population respectively. Xinong Saanen breed was in Hardy-Weinberg equilibrium, while Guanzhong breed deviated from Hardy-Weinberg equilibrium (p<0.05). The association of polymorphism with economic traits indicated that the goats with FF genotype have higher milk fat and total solid concentration than those with AA and AF genotypes (p<0.05).

432-μm Laser’s Beam-waist Measurement for the Polarimeter/Interferometer on the EAST Tokamak

Z. X. Wang,H. Q. Liu,Y. X. Jie,M. Q. Wu,T. Lan,X. Zhu,Z. Y. Zou,Y. Yang,X. C. Wei,L. Zeng,G. S. Li,X. Gao 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.65 No.8

A far-infrared (FIR) polarimeter/interferometer (PI) system is under development for measurementsof the current-density and the electron-density profiles in the EAST tokamak. The systemwill utilize three identical 432-μm CHCOOH lasers pumped by a CO2 laser. Measurements of thelaser beam’s waist size and position are basic works. This paper will introduce three methods witha beam profiler and several focusing optical elements. The beam profiler can be used to show thespatial energy distribution of the laser beam. The active area of the profiler is 12.4 × 12.4 mm2. Some focusing optical elements are needed to focus the beam in order for the beam profiler toreceive the entire laser beam. Two principles and three methods are used in the measurement. Thefirst and the third methods are based on the same principle, and the second method adopts an otherprinciple. Due to the fast and convenient measurement, although the first method is a special formof the third and it can only give the size of beam waist, it is essential to the development of theexperiment and it can provide guidance for the choices of the sizes of the optical elements in the nextstep. A concave mirror, a high-density polyethylene (HDPE) lens and a polymethylpentene (TPX)lens are each used in the measurement process. The results of these methods are close enough forthe design of PI system’s optical path.

CONSTRAINTS ON PRE-INFLATION COSMOLOGY AND DARK FLOW

MATHEWS, GRANT J.,LAN, N.Q.,KAJINO, T. The Korean Astronomical Society 2015 天文學論叢 Vol.30 No.2

If the present universe is slightly open then pre-inflation curvature would appear as a cosmic dark-flow component of the CMB dipole moment. We summarize current cosmological constraints on this cosmic dark flow and analyze the possible constraints on parameters characterizing the pre-inflating universe in an inflation model with a present-day very slightly open ${\Lambda}CDM$ cosmology. We employ an analytic model to show that for a broad class of inflation-generating effective potentials, the simple requirement that the observed dipole moment represents the pre-inflation curvature as it enters the horizon allows one to set upper and lower limits on the magnitude and wavelength scale of pre-inflation fluctuations in the inflaton field and the curvature parameter of the pre-inflation universe, as a function of the fraction of the total initial energy density in the inflaton field. We estimate that if the current CMB dipole is a universal dark flow (or if it is near the upper limit set by the Planck Collaboration) then the present constraints on ${\Lambda}CDM$ cosmological parameters imply rather small curvature ${\Omega}_k{\sim}0.1$ for the pre-inflating universe for a broad range of the fraction of the total energy in the inflaton field at the onset of inflation. Such small pre-inflation curvature might be indicative of open-inflation models in which there are two epochs of inflation.

Adiponectin Regulates Bone Marrow Mesenchymal Stem Cell Niche Through a Unique Signal Transduction Pathway: An Approach for Treating Bone Disease in Diabetes : Adiponectin Regulates BMSC Niche

Yu, Liming,Tu, Qisheng,Han, Qianqian,Zhang, Lan,Sui, Lei,Zheng, Leilei,Meng, Shu,Tang, Yin,Xuan, Dongying,Zhang, Jin,Murray, Dana,Shen, Qingping,Cheng, Jessica,Kim, Sung-Hoon,Dong, Lily Q.,Valverde, P Wiley (John WileySons) 2015 Stem Cells Vol.33 No.1

<P>Adiponectin (APN) is an adipocyte-secreted adipokine that exerts well-characterized antidiabetic properties. Patients with type 2 diabetes (T2D) are characterized by reduced APN levels in circulation and impaired stem cell and progenitor cell mobilization from the bone marrow for tissue repair and remodeling. In this study, we found that APN regulates the mobilization and recruitment of bone marrow-derived mesenchymal stem cells (BMSCs) to participate in tissue repair and regeneration. APN facilitated BMSCs migrating from the bone marrow into the circulation to regenerate bone by regulating stromal cell-derived factor (SDF)-1 in a mouse bone defect model. More importantly, we found that systemic APN infusion ameliorated diabetic mobilopathy of BMSCs, lowered glucose concentration, and promoted bone regeneration in diet-induced obesity mice. In vitro studies allowed us to identify Smad1/5/8 as a novel signaling mediator of APN receptor (AdipoR)-1 in BMSCs and osteoblasts. APN stimulation of MC3T3-E1 osteoblastic cells led to Smad1/5/8 phosphorylation and nuclear localization and increased SDF1 mRNA expression. Although APN-mediated phosphorylation of Smad1/5/8 occurred independently from adaptor protein, phosphotyrosine interaction, pleckstrin homology domain, and leucine zipper containing 1, it correlated with the disassembly of protein kinase casein kinase 2 and AdipoR1 in immunoprecipitation experiments. Taken together, this study identified APN as a regulator of BMSCs migration in response to bone injury. Therefore, our findings suggest APN signaling could be a potential therapeutic target to improve bone regeneration and homeostasis, especially in obese and T2D patients.</P>

Prevalence and genetic characterization of respiratory syncytial virus (RSV) in hospitalized children in Korea.

Baek, Yun Hee,Choi, Eun Hye,Song, Min-Suk,Pascua, Philippe Noriel Q,Kwon, Hyeok-il,Park, Su-Jin,Lee, Jun Han,Woo, Sung-Il,Ahn, Byung-Hoon,Han, Heon-Seok,Hahn, Yoon-Soo,Shin, Kyeong-Seob,Jang, Hae-Lan Springer-Verlag 2012 Archives of virology Vol.157 No.6

<P>Human respiratory syncytial virus (HRSV) is the most common respiratory pathogen among infants and young children. To investigate the prevalence and genetic characteristics of HRSVs circulating in South Korea, we analyzed medical records of patients and performed molecular analysis of the G-protein gene of viruses detected from nasopharyngeal aspirates (NPA) of admitted patients at the Pediatrics Department of Chungbuk National University Hospital from April 2008 to April 2010. Epidemiological data revealed that the prevalence of HRSV infection was high during both winter seasons (October 2008 to February 2009 and November 2009 to February 2010). Of the 297 positive NPA specimens from infants or children tested, 67% were identified as HRSV-A while 33% were HRSV-B. The HRSV subgroup B was the most dominant in December 2008, but its dominance was dramatically replaced by HRSV subgroup A strains by February 2009. Phylogenetic analysis of the G protein sequences of HRSVs revealed novel genotypes within the HRSV-A (genotype CB-A) and B (genotypes BA11 and CB-B) subgroups in South Korea in addition to other strains identified in other countries. Molecular analysis also revealed genetic variability at the C-terminal end of the G proteins of the two HRSV subgroups, suggesting selection pressure in this region, which may potentially impact immune recognition. This is the first report of these HRSV variants in South Korea, indicating active genetic evolution of HRSV strains. Therefore, this study provides information on the molecular epidemiology of current HRSVs in the country and presents data for comparative analysis with other HRSV strains circulating worldwide.</P>

Measurement of the Secondary Neutron Emission Differential and Double-Differential Cross Sections between 20 and 30 MeV

X. C. Ruan,G. C. Chen,H. X. Huang,X. Li,Y. B. Nie,B. Zhou,Z. Y. Ma,J. Bao,Q. P. Zhong,Z. Y. Zhou,H. Q. Tang,J. S. Zhang,C. L. Lan,Y. L. Zhang,Y. M. Li 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.59 No.23

More and more interests have been paid to the differential and double-differential neutron emission cross sections (DX and DDX) at above 20 MeV region in recent years. At the China Institute of Atomic Energy (CIAE), a program to measure the DX and DDX between 20 and 30 MeV neutron energy region has been carried out. The d-T reaction neutron source was used to produce the 20 - 30 MeV neutrons with a tritium gas target at the HI-13 tandem accelerator at CIAE. The time-of-flight(TOF) technique was used to measure the neutron energy from about 1 MeV to 30 MeV with 3 BC501A liquid scintillators (with a size of Φ180 ×100 mm). A preliminary measurement has been carried out for ^9Be at 22 MeV. The measured data were analyzed by detailed Monte-Carlo simulation to perform the multiple scattering, flux attenuation and finite geometry corrections. The experimental details, the data analysis, the progress, the results and the future plan will be presented in this report.