10,450 research outputs found
Filaments in Galactic Winds Driven by Young Stellar Clusters
The starburst galaxy M82 shows a system of H-emitting filaments which
extend to each side of the galactic disk. We model these filaments as the
result of the interaction between the winds from a distribution of Super
Stellar Clusters (SSCs). We first derive the condition necessary for producing
a radiative interaction between the cluster winds (a condition which is met by
the SSC distribution of M82). We then compute 3D simulations for SSC wind
distributions which satisfy the condition for a radiative interaction, and also
for distributions which do not satisfy this condition. We find that the highly
radiative models, that result from the interaction of high metallicity cluster
winds, produce a structure of H emitting filaments, which qualitatively
agrees with the observations of the M82, while the non-radiative SSC wind
interaction models do not produce filamentary structures. Therefore, our
criterion for radiative interactions (which depends on the mass loss rate and
the terminal velocity of the SSC winds, and the mean separation between SSCs)
can be used to predict whether or not an observed galaxy should have associated
H emitting filaments.Comment: 10 pages, 6 Figures. ApJ Accepted, August 7, 200
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Gabapentin for pain management after osmotic dilator insertion and prior to dilation and evacuation: A randomized controlled trial.
ObjectiveTo evaluate if gabapentin 600âŻmg reduces pain after osmotic dilator placement the day before a dilation and evacuation (D&E) procedure.Study designWe conducted a double-blind, placebo-controlled, randomized (stratified by vaginal parity) trial among women undergoing osmotic dilator placement before D&E at 15-23 5/7 weeks gestation. Subjects received gabapentin 600âŻmg or placebo 30âŻmin before dilator placement, with re-dosing 8âŻh later. We assessed pain after dilator placement using a numeric rating scale (NRS; scale 0-10) at 5âŻmin, 2, 4, and 8âŻh, and at presentation for D&E. The primary outcome was median NRS pain score change from baseline to 8âŻh after dilator placement. Secondary outcomes included gabapentin-related side effects and analgesic use.ResultsOf 121 randomized women, we excluded three subjects (allergic reaction [placebo], randomization error, no NRS data), leaving 60 gabapentin and 58 placebo subjects. Of 110 (93%) women who provided 8-hour data, median pain score changes from baseline did not differ between gabapentin and placebo groups overall (2 vs. 2.5, pâŻ=âŻ0.52), in vaginally nulliparous women (2 vs. 4, pâŻ=âŻ0.10) or in parous women (2 vs. 1.5, pâŻ=âŻ0.37). We found no statistically significant differences in median pain score change from baseline to any timepoint overall or when stratified by parity. Beginning at 2âŻh after dilator placement, more gabapentin than placebo users experienced dizziness (29/53[55%] vs. 11/53[21%], pâŻ=âŻ0.001) and tiredness (34/54[63%] vs. 17/54[31%], pâŻ=âŻ0.002). The proportion of women using narcotics did not differ between gabapentin (35/60[58%]) or placebo (40/58[69%]) users (pâŻ=âŻ0.26).ConclusionsGabapentin does not reduce pain with overnight osmotic dilator placement prior to D&E and causes drug-related side effects.Implications statementWomen experience pain, mostly mild to moderate, with overnight cervical dilator placement at 15-23 5/7 weeks gestation. About 2/3 of women will use a limited quantity of narcotics if provided. Gabapentin does not decrease the pain with or following dilator placement and does not decrease narcotic use
Ultracold heteronuclear molecules and ferroelectric superfluids
We analyze the possibility of a ferroelectric transition in heteronuclear
molecules consisting of Bose-Bose, Bose-Fermi or Fermi-Fermi atom pairs. This
transition is characterized by the appearance of a spontaneous electric
polarization below a critical temperature. We discuss the existence of a
ferroelectric Fermi liquid phase for Fermi molecules and the existence of a
ferroelectric superfluid phase for Bose molecules characterized by the
coexistence of ferroelectric and superfluid orders. Lastly, we propose an
experiment to detect ferroelectric correlations through the observation of
coherent dipole radiation pulses during time of flight.Comment: 4 pages and 3 figure
Life history of white stumpnose Rhabdosargus globiceps (Pisces: Sparidae) off South Africa
Fishery-dependent and fishery-independent distribution analyses together reveal four discrete areas of white stumpnose Rhabdosargus globiceps abundance between Port Nolloth and the Kei River off the Cape Province of South Africa: the Western Cape (Saldanha Bay), the South-Western Cape, the Southern Cape and the South-Eastern Cape. On the basis of migratory patterns determined from tagging and catch data, and on differences in growth rate and size-at-maturity, it is concluded that these areas of abundance represent four separate stocks. Each stock apparently disperses offshore in winter (to c. 130 m depth) and concentrates inshore
DNA plasmidial de isolados patogĂȘnicos de Xanthomonas campestris pv. viticola.
Poucos sĂŁo os estudos a respeito da presença de plasmĂdeos neste patĂłgeno. Nos animais, bactĂ©rias patogĂȘnicas sĂŁo conhecidas por albergar plasmĂdeos com diferentes funçÔes entre elas a resistĂȘncia, metabolismo de produtos tĂłxicos e transferĂȘncia de material genĂ©tico (Sherley et al., 2004). Nosso estudo teve por objetivo caracterizar o conteĂșdo de plasmĂdeos de isolados de X. campestris pv viticola isoladas de casos clĂnicos
Young Super Star Clusters in the Starburst of M82: The Catalogue
Recent results from Hubble Space Telescope (HST) have resolved starbursts as
collections of compact young stellar clusters. Here we present a photometric
catalogue of the young stellar clusters in the nuclear starburst of M82,
observed with the HST WFPC2 in Halpha (F656N) and in four optical broad-band
filters. We identify 197 young super stellar clusters. The compactness and high
density of the sources led us to develop specific techniques to measure their
sizes. Strong extinction lanes divide the starburst into five different zones
and we provide a catalogue of young super star clusters for each of these. In
the catalogue we include relative coordinates, radii, fluxes, luminosities,
masses, equivalent widths, extinctions, and other parameters. Extinction values
have been derived from the broad-band images. The radii range between 3 and 9
pc, with a mean value of 5.7 +/- 1.4pc, and a stellar mass between 10e4 and
10e6 Mo. The inferred masses and mean separation, comparable to the size of
super star clusters, together with their high volume density, provides strong
evidence for the key ingredients postulated by Tenorio et al. (2003) as
required for the development of a supergalactic wind.Comment: 45 pages, 5 figures, 12 tables. Accepted for publication in ApJ.
Added Erratu
Herman's Theory Revisited
We prove that a -smooth orientation-preserving circle
diffeomorphism with rotation number in Diophantine class ,
, is -smoothly conjugate to a rigid
rotation. We also derive the most precise version of Denjoy's inequality for
such diffeomorphisms.Comment: 10 page
Resposta do umbuzeiro Ă adubação fosfatada e Ă inoculação com fungos micorrĂzicos arbusculares.
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