618 research outputs found
Molecular line and continuum study of the W40 cloud
The dense cloud associated with W40, one of the nearby H II regions, has been
studied in millimeter-wave molecular lines and in 1.2 mm continuum. Besides,
1280 MHz and 610 MHz interferometric observations have been done. The cloud has
complex morphological and kinematical structure, including a clumpy dust ring
and an extended dense core. The ring is probably formed by the "collect and
collapse" process due to the expansion of neighboring H II region. Nine dust
clumps in the ring have been deconvolved. Their sizes, masses and peak hydrogen
column densities are: pc, and cm, respectively. Molecular lines are observed
at two different velocities and have different spatial distributions implying
strong chemical differentiation over the region. The CS abundance is enhanced
towards the eastern dust clump 2, while the NH, NH, and
HCO abundances are enhanced towards the western clumps. HCN and
HCO do not correlate with the dust probably tracing the surrounding gas.
Number densities derived towards selected positions are: cm. Two western clumps have kinetic temperatures 21 K and 16 K and
are close to virial equilibrium. The eastern clumps 2 and 3 are more massive,
have higher extent of turbulence and are probably more evolved than the western
ones. They show asymmetric CS(2--1) line profiles due to infalling motions
which is confirmed by model calculations. An interaction between ionized and
neutral material is taking place in the vicinity of the eastern branch of the
ring and probably trigger star formation.Comment: 16 pages, 6 figure
Multi-frequency Studies of Massive Cores with Complex Spatial and Kinematic Structures
Five regions of massive star formation have been observed in various
molecular lines in the frequency range GHz. The studied regions
possess dense cores, which host young stellar objects. The physical parameters
of the cores are estimated, including kinetic temperatures ( K),
sizes of the emitting regions ( pc), and virial masses (). Column densities and abundances of various molecules are
calculated in the local thermodynamical equilibrium approximation. The core in
99.982+4.17, associated with the weakest IRAS source, is characterized by
reduced molecular abundances. Molecular line widths decrease with increasing
distance from the core centers (). For b\ga 0.1~pc, the dependences
are close to power laws (), where varies from
to , depending on the object. In four cores, the
asymmetries of the optically thick HCN(1--0) and HCO(1--0) lines indicate
systematic motions along the line of sight: collapse in two cores and expansion
in two others. Approximate estimates of the accretion rates in the collapsing
cores indicate that the forming stars have masses exceeding the solar mass.Comment: 18 pages, 7 figures, 6 table
Cortical interstitial cell interactions induce sensitivity of hydronephrotic kidney to bradykinin
Cortical interstitial cell interactions induce sensitivity of hydronephrotic kidney to bradykinin. The mechanism of the increased prostaglandin production and induction of sensitivity to bradykinin by the cortex of the hydronephrotic rabbit kidney was investigated using tissue culture techniques. Cortical interstitial cells from normal, unilaterally hydronephrotic and contralateral kidneys were grown in tissue culture. Cells derived from hydronephrotic kidneys, but not normal or contralateral, increased PGE2 production when incubated with bradykinin. Of the two cell types, fibroblasts and macrophages, grown from hydronephrotic expiants, neither increased prostaglandin production when grown alone in tissue culture. Recombining the two cell types restored bradykinin responsiveness. Bradykinin responsiveness could be induced in either normal or contralateral cell cultures when macrophages from the hydronephrotic kidney were added to cultures of cells from normal or contralateral cortex. The data indicate unique characteristics of hydronephrotic macrophages are involved in the induction of bradykinin responsiveness in the cortex of the ureter-ligated kidney
Extended Star Formation and Molecular Gas in the Tidal Arms near NGC3077
We report the detection of ongoing star formation in the prominent tidal arms
near NGC 3077 (member of the M 81 triplet). In total, 36 faint compact HII
regions were identified, covering an area of ~4x6 kpc^2. Most of the HII
regions are found at HI column densities above 1x10^21 cm^-2 (on scales of 200
pc), well within the range of threshold columns measured in normal galaxies.
The HII luminosity function resembles the ones derived for other low-mass dwarf
galaxies in the same group; we derive a total star formation rate of 2.6x10^-3
M_sun/yr in the tidal feature. We also present new high-resolution imaging of
the molecular gas distribution in the tidal arm using CO observations obtained
with the OVRO interferometer. We recover about one sixth of the CO flux (or
M_H2~2x10^6 M_sun, assuming a Galactic conversion factor) originally detected
in the IRAM 30m single dish observations, indicating the presence of a diffuse
molecular gas component in the tidal arm. The brightest CO peak in the
interferometer map (comprising half of the detected CO flux) is coincident with
one of the brightest HII regions in the feature. Assuming a constant star
formation rate since the creation of the tidal feature (presumably ~3x10^8
years ago), a total mass of ~7x10^5 M_sun has been transformed from gas into
stars. Over this period, the star formation in the tidal arm has resulted in an
additional enrichment of Delta(Z)>0.002. The reservoir of atomic and molecular
gas in the tidal arm is ~3x10^8 M_sun, allowing star formation to continue at
its present rate for a Hubble time. Such wide-spread, low-level star formation
would be difficult to image around more distant galaxies but may be detectable
through intervening absorption in quasar spectra.Comment: Accepted for publication in the Astronomical Journa
The benefits of reducing anxiety in a Podiatric Surgical Unit in the UK with Midazolam
La sedación se ha utilizado con frecuencia junto a muchas de las intervenciones quirúrgicas realizadas bajo anestésicos locales (AL) . En la cirugía podológica, hay una escasez de literatura sobre los efectos de la sedación ante las señales fisiológicas de los pacientes. La anestesia general se practica con mayor frecuencia que la sedación con anestésico local en podología . El objetivo de esta estudioa fue analizar la presión arterial ( PA) y frecuencia cardiaca (FC ) en contra de la administración de midazolam. Se realizó una evaluación retrospectiva de las registros de sedación antes de los procedimientos de podología llevadas a cabo durante los años 2008/2009 . La PA ( sistólica / diastólica mm de Hg ) y la FC ( latidos / min ) se registraron antes de la administración de midazolam y durante los primeros 30 minutos después de la administración . Noventa y cuatro pacientes ( 74 mujeres, 20 hombres) fueron ingresados para cirugía podológica . Se realizaron Noventa y nueve intervenciones , con cinco de los sujetos sometidos a dos procedimientos. La edad media fue de 59 ± 13,5 años ( 21-87 ) y la dosis media de midazolam administrado fue 2,8 ± 1,3 mg ( 0,5-8 ) . La media de la PA antes de administrar midazolam fue de 148 /85 mmHg y la FC 80. A los 30 minutos la PA era de 136 /80 y la FC 71 . La PA y la FC fueron significativamente diferentes con una p < 0,001 para la lectura antes de la administración. Los resultados presentados indican el uso de este fármaco junto con el anestesico local en un contexto de sedación tiene resultados favorables.Sedation has been frequently used alongside many surgical interventions under local anaesthetics (LA). In podiatric surgery, there is a paucity of literature on the effects of sedation drugs on surrogate measures of patients’ physiological signs. General anaesthetic is practised more frequently than sedation assisted local anaesthetic in podiatry. The aim of this audit was to analyse blood pressure (BP) and heart rate (HR) against the administration of midazolam. A retrospective assessment of sedation notes prior to podiatric procedures undertaken during the years 2008/2009 was performed. BP (systolic/diastolic mm Hg) and heart rate (beats/min) were recorded prior to the administration of midazolam and for the first 30 minutes following administration. Ninety-four consecutive patients (74 women, 20 men) were admitted for podiatric surgery. Ninety-nine interventions were performed, with five of the subjects undergoing two procedures. The mean age was 59±13.5 years (21-87) and average midazolam administered 2.8±1.3 mg (0.5-8). Average BP prior to midazolam was 148/85 mm Hg and HR 80. At 30 minutes assessment BP was 136/80 and HR 71. BP and HR differences were significantly different at p<0.001 to the reading prior to administration. The results presented indicate the use of such a drug as an adjunct to LA in a sedation context has favourable results
VLA Observations of H I in the Helix Nebula (NGC 7293)
We report the detection of 21-cm line emission from H I in the planetary
nebula NGC 7293 (the Helix). The observations, made with the Very Large Array,
show the presence of a ring of atomic hydrogen that is associated with the
outer portion of the ionized nebula. This ring is most probably gas ejected in
the AGB phase that has been subsequently photodissociated by radiation from the
central star. The H I emission spreads over about 50 km/s in radial velocity.
The mass in H I is approximately 0.07 solar masses, about three times larger
than the mass in molecular hydrogen and comparable with the mass in ionized
hydrogen.Comment: 19 pages, 9 figure
Extended Recurrence Plot Analysis and its Application to ERP Data
We present new measures of complexity and their application to event related
potential data. The new measures base on structures of recurrence plots and
makes the identification of chaos-chaos transitions possible. The application
of these measures to data from single-trials of the Oddball experiment can
identify laminar states therein. This offers a new way of analyzing
event-related activity on a single-trial basis.Comment: 21 pages, 8 figures; article for the workshop ''Analyzing and
Modelling Event-Related Brain Potentials: Cognitive and Neural Approaches``
at November 29 - December 01, 2001 in Potsdam, German
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Management of dry flue gas desulfurization by-products in underground mines. The development and testing of collapsible intermodal containers for the handling and transport of coal combustion residues
SEEC, Incorporated, is developing a collapsible intermodal container (CIC{trademark}) designed for containment and transport of fly ash and other dry-flowable bulk commodities. The CIC is specially configured to ride in open top rail cars, but as an intermodal container, it also rides in barges and on flat bed trailers. This allows SEEC to use unit coal train back haul capacity to transport fly ash to markets at and near coal mines. SEEC`s goals for this project were to design a CIC for handling and transporting dry fly ash, and then demonstrate the CIC technology. During this project, SEEC has performed extensive initial design work, leading to the manufacture of three prototype CICs for demonstration. Preliminary tests to examine safety issues included finite element analyses and an overload test in which the CIC was lifted while carrying weight in excess of its rated capacity. In both cases, the CIC met all safety requirements. With the above information satisfying possible safety concerns in hand, SEEC worked with SIU and other cooperators to plan and carry out field demonstration and testing of three CICs. This demonstration/testing including filling the CICs with fly ash, transporting them in a coal hopper car, handling with standard intermodal equipment, and emptying by inverting (two CICs) and by vacuuming (one CIC). Results were very positive. Filling with fly ash, transporting, and intermodal handling went very well, as did emptying by vacuum. Emptying by inverting was less successful, but most of the problems were predicted ahead of time, and were mostly due to lack of fly ash fluidizing equipment as much as anything. Throughout the testing, valuable information was gathered that will greatly accelerate refinement of both the CIC and the system of CIC handling
Star formation around the H II region Sh2-235
We present a picture of star formation around the H ii region Sh2-235 (S235) based upon data on the spatial distribution of young stellar clusters and the distribution and kinematics of molecular gas around S235. We observed 13CO (1-0) and CS (2-1) emission toward S235 with the Onsala Space Observatory 20-m telescope and analysed the star density distribution with archival data from the Two Micron All-Sky Survey (2MASS). Dense molecular gas forms a shell-like structure at the southeastern part of S235. The young clusters found with 2MASS data are embedded in this shell. The positional relationship of the clusters, the molecular shell and the H ii region indicates that expansion of S235 is responsible for the formation of the clusters. The gas distribution in the S235 molecular complex is clumpy, which hampers interpretation exclusively on the basis of the morphology of the star-forming region. We use data on kinematics of molecular gas to support the hypothesis of induced star formation, and distinguish three basic types of molecular gas components. The first type is primordial undisturbed gas of the giant molecular cloud, the second type is gas entrained in motion by expansion of the H ii region (this is where the embedded clusters were formed) and the third type is a fast-moving gas, which might have been accelerated by winds from the newly formed clusters. The clumpy distribution of molecular gas and its kinematics around the H ii region implies that the picture of triggered star formation around S235 can be a mixture of at least two possibilities: the 'collect-and-collapse' scenario and the compression of pre-existing dense clumps by the shock wave. Journal compilation © 2008 RAS
Anomalous radio emission from dust in the Helix
A byproduct of experiments designed to map the CMB is the recent detection of
a new component of foreground Galactic emission. The anomalous foreground at ~
10--30 GHz, unexplained by traditional emission mechanisms, correlates with
100um dust emission. We report that in the Helix the emission at 31 GHz and
100um are well correlated, and exhibit similar features on sky images, which
are absent in H\beta. Upper limits on the 250 GHz continuum emission in the
Helix rule out cold grains as candidates for the 31 GHz emission, and provide
spectroscopic evidence for an excess at 31 GHz over bremsstrahlung. We estimate
that the 100um-correlated radio emission, presumably due to dust, accounts for
at least 20% of the 31 GHz emission in the Helix. This result strengthens
previous tentative interpretations of diffuse ISM spectra involving a new dust
emission mechanism at radio frequencies. Very small grains have not been
detected in the Helix, which hampers interpreting the new component in terms of
spinning dust. The observed iron depletion in the Helix favors considering the
identity of this new component to be magnetic dipole emission from hot
ferromagnetic grains. The reduced level of free-free continuum we report also
implies an electronic temperature of Te=4600\pm1200K for the free-free emitting
material, which is significantly lower than the temperature of 9500\pm500K
inferred from collisionally-excited lines (abridged).Comment: Accepted for publication in Ap
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