CANDELS Sheds Light on the Environmental Quenching of Low-mass Galaxies

Guo, Yicheng,Bell, Eric F.,Lu, Yu,Koo, David C.,Faber, S. M.,Koekemoer, Anton M.,Kurczynski, Peter,Lee, Seong-Kook,Papovich, Casey,Chen, Zhu,Dekel, Avishai,Ferguson, Henry C.,Fontana, Adriano,Giavalis American Astronomical Society 2017 ASTROPHYSICAL JOURNAL LETTERS - Vol.841 No.2

<P>We investigate the environmental quenching of galaxies, especially those with stellar masses (M-*) < 10(9.5) Me-circle dot, beyond the local universe. Essentially all local low-mass quenched galaxies (QGs) are believed to live close to massive central galaxies, which is a demonstration of environmental quenching. We use CANDELS data to test whether or not such a dwarf QG-massive central galaxy connection exists beyond the local universe. For this purpose, we only need a statistically representative, rather than complete, sample of low-mass galaxies, which enables our study to z greater than or similar to 1.5. For each low-mass galaxy, we measure the projected distance (d(proj)) to its nearest massive neighbor (M-* > 10(10.5) M-circle dot) within a redshift range. At a given z and M-*, the environmental quenching effect is considered to be observed if the d(proj) distribution of QGs (d(proj)(Q)) is significantly skewed toward lower values than that of star-forming galaxies (d(proj)(SF)). For galaxies with 10(8) M-circle dot < M-* < 10(10) M-circle dot, such a difference between d(proj)(Q) and d(proj)(SF) is detected up to z similar to 1. Also, about 10% of the quenched galaxies in our sample are located between two and four virial radii (R-Vir) of the massive halos. The median projected distance from low-mass QGs to their massive neighbors, d(proj)(Q)/R-Vir, decreases with satellite M-* at M-* less than or similar to 10(9.5) M-circle dot, but increases with satellite M-* at M-* greater than or similar to 10(9.5) M-circle dot. This trend suggests a smooth, if any, transition of the quenching timescale around M-* similar to 10(9.5) M-circle dot at 0.5 < z < 1.0.</P>

Tracking the monthly changes of dissolved organic matter composition in a newly constructed reservoir and its tributaries during the initial impounding period

Chen, M.,He, W.,Choi, I.,Hur, J. ECOMED PUBLISHERS 2016 Environmental science and pollution research inter Vol.23 No.2

<P>Understanding the roles of inland reservoirs becomes increasingly important with respect to global carbon cycling as well as water resource management due to the unprecedented demand for construction in recent decades. In this study, the dissolved organic matter (DOM) quantity and quality in a newly constructed dam reservoir and its tributaries were monitored monthly during the initial impounding period (July to November 2014) using a size exclusion chromatography (SEC) with online organic carbon detector (OCD). The highest values were observed in the month of August with the highest precipitation for the bulk dissolved organic carbon (DOC), specific UV absorbance (SUVA), and most of the assigned size fractions (except for biopolymers) in the tributaries, indicating that allochthonous sources of DOM were dominant in the feeding stream waters of the reservoir. The bulk DOC and high molecular weight humic substance fraction (similar to 1 kDa) were generally co-varied with the monthly precipitation in the tributaries, while building blocks (350-500 Da), and low molecular weight (LMW) acids and neutrals showed different trends. In a dam site, the smaller molecular fractions became more abundant during the dry season (September to November), presumably due to the in-reservoir processes such as photo- and bio-degradation. Our results also revealed that storms mobilized a large amount of highly aromatic soil-derived DOM to the reservoir. A depth profile at the dam site showed the water is well mixed up to a depth of similar to 20 m. The SEC-OCD data coupled with non-metric multidimensional scaling provided a clear visualization of the spatiotemporal variations in DOM composition, which shed new light on the DOM composition formed in a newly constructed dam reservoir and also on the strategies for future water treatment options.</P>

Mössbauer and MCD spectroscopy of the Fe3S4 nanoparticles synthesized by the thermal decomposition method with two different surfactants

Ivantsov Ruslan D.,Lin Chun-Rong,Ivanova Oxana S.,Altunin Roman R.,Knyazev Yuriy V.,Molokeev Maxim S.,Zharkov Sergey M.,Chen Ying-Zhen,Lin En-Szu,Chen Bing-Yi,Shestakov Nikolai P.,Edelman Irina S. 한국물리학회 2021 Current Applied Physics Vol.25 No.-

Greigite (Fe3S4) nanoparticles (NPs) were fabricated by the thermal decomposition method using two different surfactants: oleylamine (OLA) and 1-hexadecylamine (HDA). In both cases, the synthesized NPs were characterized as the Fe3S4 nanocrystals with minor inclusions of Fe9S11 phase. FT-IR spectroscopy and thermogravimetric analysis allow concluding about OLA or HDA shells covering magnetic core of NPs. M¨ossbauer spectra has revealed deviations of iron ions distribution among crystal positions from that presented in literature for pure greigite. In accordance with these deviations, the pronounce changes are observed in the magnetic circular dichroism (MCD) spectra which manifest themselves as the spectrum shift to higher energies of electromagnetic waves and redistribution of the MCD maximum intensities. These effects are associated with a change in the density of electronic states in the samples due to the redistribution of iron ions between octahedral and tetrahedral positions in nanocrystals under the influence of surfactants.

New Evidence of Alleles (V199I and G52S) at the PRKAG3 (RN) Locus Affecting Pork Meat Quality

Chen, J.F.,Dai, L.H.,Peng, J.,Li, J.L.,Zheng, R.,Zuo, B.,Li, F.E.,Liu, M.,Yue, K.,Lei, M.G.,Xiong, Y.Z.,Deng, C.Y.,Jiang, S.W. Asian Australasian Association of Animal Productio 2008 Animal Bioscience Vol.21 No.4

The porcine PRKAG3 (RN) gene encodes the regulatory gamma subunit of adenosine monophosphate-activated protein kinase (AMPK), which is a good candidate gene affecting meat quality. In this study, the effects of two missense mutations A595G (Ile199Val) and G154A (Gly52Ser) in porcine PRKAG3 gene on meat quality traits were studied in M. Longissimus dorsi (LD), M. Semispinalis capitis (SC) and M. Biceps femoris (BF) from different populations of 326 pigs. The PRKAG3 alleles 199I, 199IV, 52S and 52G were identified with PCR-RFLPs and all genotypes - 199I/199I, 199I/199V, 199V/199V, 52S/52S, 52S/52G and 52G/52G - were found. The frequency of V allele was larger than that of I allele in all populations. I allele frequency was zero in Chinese Meishan pigs (population D) especially. G allele frequency was larger than that of S allele in all populations except Large White (population A). Both variations at the PRKAG3 locus significantly affected these meat quality traits. The pork meat quality has not previously been established in Meishan or crosses thereof. The results suggested that generally pH of LD, SC and BF was higher in Meishan pigs than that in other populations. Moreover, Meishan pigs showed higher water-holding capacity and intramuscular fat (IMF), lower water content and water loss percentage compared to other populations in terms of the two variations. The results present here supply new evidence that alleles V199I and G52S at the PRKAG3 locus affect pork meat quality and provide useful information on pork production.

Osmotically driven membrane processes: Exploring the potential of branched polyethyleneimine as draw solute using porous FO membranes with NF separation layers

Cho, M.,Lee, S.H.,Lee, D.,Chen, D.P.,Kim, I.C.,Diallo, M.S. Elsevier Scientific Pub. Co 2016 Journal of membrane science Vol.511 No.-

Forward osmosis (FO) is a promising membrane process with the potential to offer more efficient separation technologies for various environmental and industrial applications including (i) water reuse, (ii) desalination, and (iii) resource recovery. However, a major and unresolved challenge in FO remains the availability of efficient draw solutions that could be (i) implemented using porous and high flux FO membranes and (ii) reconstituted using a low-energy separation process. This study investigates the potential use of a branched polyethyleneimine (PEI) macromolecule (M<SUB>w</SUB> of 25,000Da) as osmotic agent to formulate new draw solutions that could be deployed using porous FO membranes with nanofiltration (NF) selective layers. To asses the potential of PEI-based draw solutions, we combine (i) osmotic pressure measurements, (ii) membrane preparation and characterization, (iii) water flux and reverse solute permeation measurements and (iv) draw solution concentration experiments using NF. The overall results of this study suggest that branched PEI macromolecules (M<SUB>w</SUB> of 25,000Da) are promising building blocks for the development of draw solutions for osmotically-driven membrane processes using a nanofibrous composite (NFC) polyacrylonitrile (PAN) membrane with an NF selective layer and no polyethylene terephthalate (PET) microporous support.

간호대생과 비보건계열 여대생의 미세먼지 위험에 대한 인식과 지식, 건강 관리행위 비교 연구

김선미,김슬기,김진선,박주형,배다희,유수빈,유영주,임지향,최유진,Chen Mengyao,양숙자,손지희 이화여자대학교 간호과학대학 2019 이화간호학회지 Vol.- No.53

Purpose: This study aimed to know whether there is a comparison of perception, knowledge and health promoting behaviors about particular matter between nursing students and non-health departments college students. Methods: A quantitative research is used. Data were collected from August 1 to 19. The study sample was nursing students and non-health departments students. For the similar condition of samples, this study excluded whose first language is not Korean. Independent T-test and pearson’s correlation was used for this study. Results: A significant positive correlation did not existed between difference of major and perception(t=0.017, p=0.986), knwledge(t=0.652, p=.516) and health promoting behaviors(t=-0.114, p=.910) about particular matters. Conclusion: Based on the study results, there is no significant correlation of perception and actions about particular matters between nursing students and non-health department college students.

<tex> $1.3~\mu $</tex> m Optical Interconnect on Silicon: A Monolithic III-Nitride Nanowire Photonic Integrated Circuit

Hazari, Arnab,Fu Chen Hsiao,Lifan Yan,Junseok Heo,Millunchick, Joanna Mirecki,Dallesasse, John M.,Bhattacharya, Pallab IEEE 2017 IEEE journal of quantum electronics Vol.53 No.4

<P>A feasible optical interconnect on a silicon complementary metal-oxide-semiconductor chip demands epitaxial growth and monolithic integration of diode lasers and optical detectors with guided wave components on a (001) Si wafer, with all the components preferably operating in the wavelength range of 1.3-1.55 μm at room temperature. It is also desirable for the fabrication technique to be relatively simple and reproducible. Techniques demonstrated in the past for having optically and electrically pumped GaAs and InP-based lasers on silicon include wafer bonding, selective area epitaxy, epitaxy on tilted substrates, and use of quantum dot or planar buffer layers. Here, we present a novel monolithic optical interconnect on a (001) Si substrate consisting of a III-nitride dot-in-nanowire array edge emitting diode laser and guided wave photodiode, with a planar SiO<SUB>2</SUB>/Si<SUB>3</SUB>N<SUB>4</SUB> dielectric waveguide in between. The active devices are realized with the same nanowire heterostructure by one-step epitaxy. The electronic properties of the InN dot-like nanostructures and mode confinement and propagation in the nanowire waveguides have been modeled. The laser, emitting at the desired wavelength of 1.3 μm, with threshold current ~350 mA for a device of dimension 50 μm × 2 mm, has been characterized in detail. The detector exhibits a responsivity ~0.1 A/W at 1.3 μm. Operation of the entire optical interconnect via the dielectric waveguide is demonstrated.</P>

Seismogenic structures of the 1999 M_w 7.6 Chi-Chi, Taiwan, earthquake and its aftershocks

Kim, K.H.,Chen, K.C.,Wang, J.H.,Chiu, J.M. Elsevier Scientific Publishing Co 2010 Tectonophysics Vol.489 No.1

High-resolution 3-D V<SUB>P</SUB> and V<SUB>S</SUB> velocity models around the source region of the M<SUB>w</SUB>7.6 Chi-Chi, Taiwan, earthquake show significant lateral and vertical variations. The mainshock occurred within a narrow low velocity zone along the Chelungpu fault. A sudden increase of velocity and seismicity took place across the Shuilikeng fault to the east. Most aftershocks were located in areas of high V<SUB>P</SUB> and V<SUB>S</SUB>. A sharp east-dipping zone extending from the Shuilikeng fault on the surface to a depth of about 15km separates the low velocity region in the west from the high velocity region in the east. An apparent high-angle west-dipping seismic zone lies at depths of 15-30km beneath the western Central Range. Numerous aftershocks with normal faulting were located west of the middle segment of the Chelungpu fault.

Nitrate Reduction and Pigment Formation of Chinese-Style Sausage Mixes Caused by Micrococcaceae

Guo, H.L.,Chen, M.T.,Liu, D.C. Asian Australasian Association of Animal Productio 2000 Animal Bioscience Vol.13 No.8

This study investigated the nitrate reduction ability of Micrococcaceae on pigment formation in Chinese- style sausage. One hundred ppm sodium nitrite and 150 ppm sodium nitrate was added asepticly to ground pork which was then inoculated with $10^7CFU/g$ of either Micrococcus varians, Staphylococcus carnosus or Staphylococcus xylosus. All samples were cured at $20{^{\circ}C}$ or $30{^{\circ}C}$ for 3 days and then color, residue nitrite, nitrosyl pigment and residue nitrate were determined. The results indicated that samples inoculated with S. xylosus had higher a- and b- values due to nitrate reduction and pigment production after 3 days curing and these values were higher at the higher curing temperature. The nitrosyl pigment of the samples with S. xylosus had highest values after 3 days curing at both $20{^{\circ}C}$ and $30{^{\circ}C}$. However, sample inoculated with S. carnosus and S. xylosus had lower nitrate contents than the sample inoculated with M. varians. At $30{^{\circ}C}$ as well as S. carnosus and M. varians had a stronger decreasing in nitrate concentration during curing at $20{^{\circ}C}$. Moreover, samples inoculated with S. xylosus and S. carnosus had a higher residual nitrite content during curing at $20{^{\circ}C}$ or $30{^{\circ}C}$. In conclusion, two Staphylococci strains tested were most optimum starter cultures for improving pigment formation during Chinese-style sausage curing.

Studies on Cryopreservation of D-shaped and Umbo Larvae of Arkshel1(Scapharca broughtonii)

K.H. Kang,K. H. Kho,Z.T. Chen,Kim Y.H.,Kim J.M. 한국발생생물학회 2003 한국발생생물학회 학술발표대회 Vol.2003 No.1

The present study examined the possibility of cryopreservation of the D-shaped and umbo larvae of arkshell (Scapharca broughtonii), in terms of the survival rates after freezing and thawing. D-shaped and umbo larvae of arkshells were obtained from a shellfish farming on Yosu city. The average shell lengths were m and , respectively. Five cryoprotectants (CPAs), dimethyl sulfoxide (DMSO), glycerol, ethylene glycol (EG), propylene glycol (PG), and methanol, were tested at the concentrations of 1.5, 2.0 and 2.5 M. After larvae suspended in CPAs, cryoprotectants were loaded in 0.5 ml straws at a larval density of 50-100 larvae per straw, and epuilibrated for 10 and 20 minute at room temperature (), repectively. Straws were cooled at a rate of /min from to , held for 5 min at , and then cooled at /min to and equilibrated for 5 min followed by plunging in liquid nitrogen. After storage in liquid nitrogen for 1 day, straws were thawed in a water. As soon as straws were observed to melt, larvae were diluted with an equal volume of ASW and then washed twice with a large volume of ASW at an interval of 2 min to unload the CPAs. The results showed that after equilibration for 10 and 20 minute at room temperature, no larvae survived using methanol as CPAs, and it was observed that larval shells all open slightly, and larval flesh broke down and slopped over the shells. The highest survival rates (D-shaped larvae: 77.6%, umbo larvae: 59.3%) were obtained with 2M DMSO, and 1.5M glycerol yielded survival rates of 53.8% for D-shaped larvae and 37.5% for umbo larvae. The surviving D-shaped larvae showed active rotary motion and perfect membrane integrity and cytoplasmic normality, and the vigorous movement of veliger cilia was observed inside the closed shells. The breakdown of tissue occurred in the abnormal larvae, and the isolated cell often run out of shells.