Chandra Observation of the Edge-on Spiral NGC 5775: Probing the Hot Galactic Disk/Halo Connection

We study the edge-on galaxy NGC 5775, utilizing a 58.2 ks {\sl Chandra} ACIS-S observation together with complementary {\sl HST} ACS, {\sl Spitzer} IRAC and other multi-wavelength data sets. This edge-on galaxy, with its disk-wide active star formation, is particularly well-suited for studying the disk/halo interaction on sub-galactic scales. We detect 27 discrete X-ray sources within the $D_{25}$ region of the galaxy, including an ultra-luminous source with a 0.3-7 keV luminosity of $\sim7\times10^{40}\rm ergs s^{-1}$. The source-removed diffuse X-ray emission shows several prominent extraplanar features, including a $\sim10\rm kpc$ diameter ``shell-like'' feature and a ``blob'' reaching a projected distance of $\sim25\rm kpc$ from the galactic disk. The bulk of the X-ray emission in the halo has a scale height of $\sim$1.5 kpc and can be characterized by a two-temperature optically thin thermal plasma with temperatures of $\sim$ 0.2 and 0.6 keV and a total 0.3-2 keV luminosity of $\sim3.5\times10^{39}\rm ergs s^{-1}$. The high-resolution, multi-wavelength data reveal the presence of several extraplanar features around the disk, which appear to be associated with the in-disk star formation. We suggest that hot gas produced with different levels of mass loading can have different temperatures, which may explain the characteristic temperatures of hot gas in the halo. We have obtained a sub-galactic scale X-ray-intensity-star formation relation, which is consistent with the integrated version in other star forming galaxies.Comment: 25 pages, 10 figures, 4 tables, accepted for publication in MNRA

Design possibilities for the e-Schoolbag: addressing the 1:1 challenge within China

There is widespread enthusiasm for 1:1 computing in education. Recognizing that secure innovation of educational practice should be built upon contextual sensitivity, this article reported two case studies anticipating the potential development of 1:1 classes in the particular cultural context of China. The first case described how the new technology of e-Textbooks could align with a tradition where the textbook is central to teaching practice. A science teacher used the e-Textbook to design his pedagogy to accommodate the contextual learning needs of the classroom. Students reported a positive reaction. They understood that new learning possibilities were crafted through this engagement with diversified media formats that content fitted their class, and this gave them increased confidence in relation to both student–computer and interpersonal interaction. The second case study described how a social app could align with the local tradition of practice whereby a student’s performance in front of class is an important part of instructional practice. In this case, students who were learning native Chinese were offered the opportunity for performing within a novel “digital stage”: revealing high levels of engagement and a strengthening confidence with language performance

Dynamic S0 Galaxies: a Case Study of NGC 5866

S0 galaxies are often thought to be passively evolved from spirals after star formation is quenched. To explore what is occurring in S0s, we present a multi-wavelength study of NGC5866--an isolated nearby edge-on S0. This study shows strong evidence for dynamic activities in the interstellar medium, which are most likely driven by supernova explosions in the galactic disk and bulge. We utilize Chandra, HST, and Spitzer data as well as ground-based observations to characterize the content, structure, and physical state of the medium and its interplay with stars in NGC5866. A cold gas disk is detected with an exponential scale height of 100pc. Numerous off-disk dusty spurs are clearly present: prominent ones can extend as far as 300pc from the galactic plane and are probably produced by individual SNe, whereas faint filaments can have ~ kpc scale and are likely produced by SNe collectively in disk/bulge. We also detect substantial amounts of diffuse Ha- and Pa-emitting gas with a comparable scale height as the cold gas. We find that the heating of the dust and warm ionized gas cannot be explained by the radiation from evolved stars alone, strongly indicating the presence of young stars in the disk at a low formation rate of ~ 0.05Msun/yr. We reveal the presence of diffuse X-ray-emitting hot gas, which extends as far as 3.5kpc from the disk and can be heated easily by Type Ia SNe in the bulge. However, the temperature of this gas is ~ 0.2keV, substantially lower than what might be expected from the mass-loss of evolved stars and Type Ia SNe heating alone, indicating mass loading from cool gas is important. The total masses of the cold, warm and hot gases are ~ 5*10^8, 10^4 and 3*10^7Msun. The relative richness of the gases, undergoing circulations between disk/halo, is perhaps a result of its relative isolation.Comment: 27 pages, 6 figures, 3 tables, ApJ in press, comments are welcom

Streptomyces sparsus, sp. nov., a novel member of the genus Streptomyces from saline and alkaline soil in China

Salt and alkaline-tolerant actinomycete strain, YIM 90018T, was isolated from a saline and alkaline soil sample collected from Qinghai, China, and was then subjected to polyphasic taxonomy. Aerial hyphae of strain YIM 90018T were not produced on almost tested media except YIM 82# agar. Vegetative hyphae were abundant, developed well, and not fragmented. Straight or flexuous (Rectiflexibiles) spore chains. The strain grew well at 25% of MgCl2.6H2O and pH 10. All of these characters consistently assign the strain YIM 90018T to known species of the genus Streptomyces. Based on phylogenetic analysis of 16S rDNA, DNA-DNA hybridization, phenotypic characters and comparison with known species of the genus, strain YIM 90018T can be differentiated from all the validly described Streptomyces species. A novel species, Streptomyces sparsus sp. nov. is proposed. The type strain of the new species is YIM 90018T (CCTCC AA204019= DSM 41858T)

Streptomyces hainanensis sp nov., a novel member of the genus Streptomyces

A novel isolate belonging to the genus Streptomyces, strain YIM 47672(T), was obtained from soil from Hainan, an island in China. The characterization of this isolate was performed by using a polyphasic approach. The strain formed long spore chains in the aerial mycelia. The cell wall contained L-diaminopimelic acid, traces of meso-diaminopimelic acid and glycine. Whole-cell hydrolysates contained galactose and xylose. The phospholipid was of type II. The 16S rRNA gene sequence similarities for YIM 47672(T) with respect to the most closely related type strains of species of the genus Streptomyces were less than 96.3%. Therefore strain YIM 47672(T) represents a novel member of the genus Streptomyces, for which the name Streptomyces hainanensis sp. nov. is proposed. The type strain is YIM 47672 (T) (=CCTCC AA 205017(T) = DSM 41 900(T))

Characterization of RNase MRP RNA and novel snoRNAs from Giardia intestinalis and Trichomonas vaginalis

<p>Abstract</p> <p>Background</p> <p>Eukaryotic cells possess a complex network of RNA machineries which function in RNA-processing and cellular regulation which includes transcription, translation, silencing, editing and epigenetic control. Studies of model organisms have shown that many ncRNAs of the RNA-infrastructure are highly conserved, but little is known from non-model protists. In this study we have conducted a genome-scale survey of medium-length ncRNAs from the protozoan parasites <it>Giardia intestinalis </it>and <it>Trichomonas vaginalis</it>.</p> <p>Results</p> <p>We have identified the previously 'missing' <it>Giardia </it>RNase MRP RNA, which is a key ribozyme involved in pre-rRNA processing. We have also uncovered 18 new H/ACA box snoRNAs, expanding our knowledge of the H/ACA family of snoRNAs.</p> <p>Conclusions</p> <p>Results indicate that <it>Giardia intestinalis </it>and <it>Trichomonas vaginalis</it>, like their distant multicellular relatives, contain a rich infrastructure of RNA-based processing. From here we can investigate the evolution of RNA processing networks in eukaryotes.</p

Rotation Symmetry Spontaneous Breaking of Edge States in Zigzag Carbon Nanotubes

Analytical solutions of the edge states were obtained for the (N, 0) type carbon nanotubes with distorted ending bonds. It was found that the edge states are mixed via the distortion. The total energies for N=5 and N>=7 are lower in the asymmetric configurations of ending bonds than those having axial rotation symmetry. Thereby the symmetry is breaking spontaneously. The results imply that the symmetry of electronic states at the apex depends on the occupation; the electron density pattern at the apex could change dramatically and could be controlled by applying an external field.Comment: 19 pages, 3 figure

Comparison of regime‐sorted tropical cloud profiles observed by CloudSat with GEOS5 analyses and two general circulation model simulations

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94863/1/jgrd16832.pd

A New Measurement of the π0\pi^0 Radiative Decay Width

High precision measurements of the differential cross sections for $\pi^0$ photoproduction at forward angles for two nuclei, $^{12}$C and $^{208}$Pb, have been performed for incident photon energies of 4.9 - 5.5 GeV to extract the ${\pi^0 \to \gamma\gamma}$ decay width. The experiment was done at Jefferson Lab using the Hall B photon tagger and a high-resolution multichannel calorimeter. The ${\pi^0 \to \gamma\gamma}$ decay width was extracted by fitting the measured cross sections using recently updated theoretical models for the process. The resulting value for the decay width is $\Gamma{(\pi^0 \to \gamma\gamma)} = 7.82 \pm 0.14 ~({\rm stat.}) \pm 0.17 ~({\rm syst.}) ~{\rm eV}$. With the 2.8% total uncertainty, this result is a factor of 2.5 more precise than the current PDG average of this fundamental quantity and it is consistent with current theoretical predictions.Comment: 4 pages, 5 figure

Cas9 gRNA engineering for genome editing, activation and repression

We demonstrate that by altering the length of Cas9-associated guide RNA(gRNA) we were able to control Cas9 nuclease activity and simultaneously perform genome editing and transcriptional regulation with a single Cas9 protein. We exploited these principles to engineer mammalian synthetic circuits with combined transcriptional regulation and kill functions governed by a single multifunctional Cas9 protein.National Human Genome Research Institute (U.S.) (P50 HG005550)United States. Department of Energy (DE-FG02-02ER63445)Wyss Institute for Biologically Inspired EngineeringUnited States. Army Research Office (DARPA W911NF-11-2-0054)National Science Foundation (U.S.)United States. National Institutes of Health (5R01CA155320-04)United States. National Institutes of Health (P50 GM098792)National Cancer Institute (U.S.) (5T32CA009216-34)Massachusetts Institute of Technology. Department of Biological EngineeringHarvard Medical School. Department of GeneticsDefense Threat Reduction Agency (DTRA) (HDTRA1-14-1-0006