Dense Molecular Filaments Feeding a Starburst: ALMA Maps of CO(3-2) in Henize 2-10

We present ALMA CO(3-2) observations at 0.3 arcsec resolution of He2-10, a starburst dwarf galaxy and possible high-z galaxy analogue. The warm dense gas traced by CO(3--2) is found in clumpy filaments that are kinematically and spatially distinct. The filaments have no preferred orientation or direction; this may indicate that the galaxy is not evolving into a disk galaxy. Filaments appear to be feeding the active starburst; the velocity field in one filament suggests acceleration onto an embedded star cluster. The relative strengths of CO(3-2) and radio continuum vary strongly on decaparsec scales in the starburst. There is no CO(3--2) clump coincident with the non-thermal radio source that has been suggested to be an AGN, nor unusual kinematics. The kinematics of the molecular gas show significant activity apparently unrelated to the current starburst. The longest filament, east of the starburst, has a pronounced shear of FWHM $\sim40$~\kms\ across its $\sim$50~pc width over its entire $\approx 0.5$ kpc length. The cause of the shear is not clear. This filament is close in projection to a `dynamically distinct' CO feature previously seen in CO(1--0). The most complex region and the most highly disturbed gas velocities are in a region 200~pc south of the starburst. The CO(3--2) emission there reveals a molecular outflow, of linewidth FWZI $\sim$ 120-140 \kms, requiring an energy $\gtrsim 10^{53} \rm~ erg/s$. There is at present {\it no} candidate for the driving source of this outflow.Comment: This was revised 31 October to correct some typos and to replace Figure

Introduction of interactive learning into French university physics classrooms

We report on a project to introduce interactive learning strategies (ILS) to physics classes at the Universit\'e Pierre et Marie Curie (UPMC), one of the leading science universities in France. In Spring 2012, instructors in two large introductory classes, first-year, second-semester mechanics, and second-year introductory E&M, enrolling approximately 500 and 250 students respectively, introduced ILS into some sections of each class. The specific ILS utilized were Think-Pair-Share questions and Peer Instruction in the main lecture classrooms, and UW Tutorials for Introductory Physics in recitation sections. Pre- and post-instruction assessments (FCI and CSEM respectively) were given, along with a series of demographics questions. We were able to compare the results of the FCI and CSEM between interactive and non-interactive classes taught simultaneously with the same curriculum. We also analyzed final exam results, as well as the results of student and instructor attitude surveys between classes. In our analysis, we argue that Multiple Linear Regression modeling is superior to other common analysis tools, including normalized gain. Our results show that ILS are effective at improving student learning by all measures used: research-validated concept inventories and final exam scores, on both conceptual and traditional problem-solving questions. Multiple Linear Regression analysis reveals that interactivity in the classroom is a significant predictor of student learning, showing a similar or stronger relationship with student learning than such ascribed characteristics as parents' education, and achieved characteristics such as GPA and hours studied per week. Analysis of student and instructors attitudes shows that both groups believe that ILS improve student learning in the physics classroom, and increases student engagement and motivation

Ionized Gas Motions and the Structure of Feedback Near a Forming Globular Cluster in NGC 5253

We observed Brackett $\alpha$ 4.05$\mu$m emission towards the supernebula in NGC 5253 with NIRSPEC on Keck II in adaptive optics mode, NIRSPAO, to probe feedback from its exciting embedded super star cluster (SSC). NIRSPEC's Slit-Viewing Camera was simultaneously used to image the K-band continuum at $\sim$$0.1''$ resolution. We register the IR continuum with HST imaging, and find that the visible clusters are offset from the K-band peak, which coincides with the Br $\alpha$ peak of the supernebula and its associated molecular cloud. The spectra of the supernebula exhibit Br $\alpha$ emission with a strong, narrow core. The linewidths are 65-76 km s$^{-1}$, FWHM, comparable to those around individual ultra-compact HII regions within our Galaxy. A weak, broad (FWHM$\simeq$150-175 km s$^{-1}$) component is detected on the base of the line, which could trace a population of sources with high-velocity winds. The core velocity of Br $\alpha$ emission shifts by +13 km s$^{-1}$ from NE to SW across the supernebula, possibly indicating a bipolar outflow from an embedded object, or linked to a foreground redshifted gas filament. The results can be explained if the supernebula comprises thousands of ionized wind regions around individual massive stars, stalled in their expansion due to critical radiative cooling and unable to merge to drive a coherent cluster wind. Based on the absence of an outflow with large mass loss, we conclude that feedback is currently ineffective at dispersing gas, and the SSC retains enriched material out of which it may continue to form stars.Comment: 24 pages, 9 figure

ALMA CO(3-2) Observations of Star-Forming Filaments in a Gas-Poor Dwarf Spheroidal Galaxy

We report ALMA observations of $^{12}$CO(3-2) and $^{13}$CO(3-2) in the gas-poor dwarf galaxy NGC 5253. These 0.3"(5.5 pc) resolution images reveal small, dense molecular gas clouds that are located in kinematically distinct, extended filaments. Some of the filaments appear to be falling into the galaxy and may be fueling its current star formation. The most intense CO(3-2) emission comes from the central $\sim$100 pc region centered on the luminous radio-infrared HII region known as the supernebula. The CO(3-2) clumps within the starburst region are anti-correlated with H$\alpha$ on $\sim$5 pc scales, but are well-correlated with radio free-free emission. Cloud D1, which enshrouds the supernebula, has a high $^{12}$CO/$^{13}$CO ratio, as does another cloud within the central 100 pc starburst region, possibly because the clouds are hot. CO(3-2) emission alone does not allow determination of cloud masses as molecular gas temperature and column density are degenerate at the observed brightness, unless combined with other lines such as $^{13}$CO.Comment: 7 pages, 5 figures, Accepted to Ap

Monte Carlo Analysis of Airport Throughput and Traffic Delays Using Self Separation Procedures

This paper presents the results of three simulation studies of throughput and delay times of arrival and departure operations performed at non-towered, non-radar airports using self-separation procedures. The studies were conducted as part of the validation process of the Small Aircraft Transportation Systems Higher Volume Operations (SATS HVO) concept and include an analysis of the predicted airport capacity using with different traffic conditions and system constraints under increasing levels of demand. Results show that SATS HVO procedures can dramatically increase capacity at non-towered, non-radar airports and that the concept offers the potential for increasing capacity of the overall air transportation system

Highlights of meiotic genes in Arabidopsis thaliana

Meiosis is a fascinating and complex phenomenon and, despite its central role in sexual plant reproduction, little is known on the molecular mechanisms involved in this process. We review the progress made in recent years using Arabidopsis thaliana mutants for isolating meiotic genes. In particular, emphasis is given on the description of mutants affecting either the regular commitment to meiosis, or the mechanisms of synapsis, recombination, and cytokinesis. We believe that the isolation of genes affecting some crucial meiotic events may represent the first step towards the practical use of meiotic genes in plant breeding. The introduction of deviations in the meiotic pathway into sexual crops will have important implications for the exploitation of apomixis and sexual polyploidization. Key words: Arabidopsis, meiosis, mutants, fertility. African Journal of Biotechnology Vol. 2 (12), pp.516-520, December 200