387 research outputs found
NANTEN 12CO (J=1-0) observations around the star WR 55
Context: A complete study of the molecular and ionized gas in the environs of
the nebula RCW 78 around WR 55 is presented. Aims: The aim of this work is to
investigate the spatial distribution, physical characteristics, and kinematical
properties of the molecular gas linked to the galactic nebula RCW 78 to achieve
a better understanding of its interaction with the star and with the ionized
gas. Methods: This study was based on 12CO(1-0) fully sampled observations of a
region of ~0.45{\deg} in size around the star WR 55 and the nebula RCW 78
obtained with the 4-m NANTEN telescope, radio continuum archival data at 1.4
and 4.85 GHz, obtained from SGPS and PMNRAO Southern Radio Survey,
respectively, and available infrared MIPSGAL images at 24 microns. Results: A
molecular gas component in the velocity range from ~ -58 to -45 km s-1,
compatible with the velocity of the ionized gas, was found to be associated
with the optical nebula. Adopting a distance of ~ 5 kpc, the mass of this
molecular component is about 3.4 x 10^4 Msun. The analysis of the molecular
data revealed the presence of a velocity gradient, in agreement with the Halpha
line. New radiocontinuum flux density determinations confirm the thermal nature
of RCW 78. This indicates that the ionized gas in RCW 78 arises from
photoionization of the molecular gas component in the velocity range from -58
km s-1 to -45 km s-1. A molecular concentration at a velocity of -56.1 km s-1
(identified as C1) is very likely associated with the star HD 117797 and with a
collection of candidate YSOs, lying at a distance of 3.9 kpc, while the rest of
the molecular gas at velocities between -56 and -46 km s-1 constitute an
incomplete ring-like structure which expands around WR 55 at a velocity of
about ~ 5 km s-1. Mechanical energy and time requirements indicate that WR 55
is very capable of sustaining the expansion of the nebula.Comment: 14 pages, 10 figures.Accepted for publication in A&
The embedded clusters DBS 77, 78, 102, and 160-161 and their link with the interstellar medium
Aims. We report a study of the global properties of some embedded clusters
placed in the fourth quadrant of the Milky Way to clarify some issues related
with their location into the Galaxy and their stellar formation processes.
Methods. We performed BVI photometric observations in the region of DBS 77, 78,
102, 160, and 161 clusters and infrared spectroscopy in DBS 77 region. They
were complemented with JHK data from VVV survey combined with 2MASS catalogue,
and used mid-infrared information from GLIMPSE catalogue. We also searched for
HI data from SGPS and PMN radio surveys, and previous spectroscopic stellar
classification. The spectroscopic and photometric information allowed us to
estimate the spectral classification of the brightest stars of each studied
region. On the other hand, we used the radio data to investigate the
interstellar material parameters and the continuum sources probably associated
with the respective stellar components. Results. We estimated the basic
physical parameters of the clusters (reddening, distance, age, and initial mass
function). We searched for HII regions located near to the studied clusters and
we analyzed the possible link between them. In the particular case of DBS
160-161 clusters, we identified the HI bubble B332.5-0.1-42 located around
them. We found that the mechanical energy injected to the interstellar medium
by the more massive stars of this couple of clusters was enough to generate the
bubble.Comment: 15 pages, 14 figures, 6 tables, accepted for publication in A&
A radio continuum survey of the southern sky at 1420 MHz. Observations and data reduction
We describe the equipment, observational method and reduction procedure of an
absolutely calibrated radio continuum survey of the South Celestial Hemisphere
at a frequency of 1420 MHz. These observations cover the area 0h < R.A. < 24h
for declinations less than -10 degree. The sensitivity is about 50 mK T_B (full
beam brightness) and the angular resolution (HPBW) is 35.4', which matches the
existing northern sky survey at the same frequency.Comment: 9 pages with 9 figures, A&A, in pres
Immediate Nonocclusal Versus Early Loading of Dental Implants in Partially Edentulous Patients – —15-year Follow-up of a Multicentre Randomised Controlled Trial
PURPOSE. To compare peri-implant bone and soft-tissue levels at immediately non-oc-clusally loaded versus non-submerged early-loaded implants in partially edentulous patients 15 years after loading. MATERIALS AND METHODS. Fifty-two patients from five Italian private practices were randomised, 25 to immediate loading and 27 to early loading. To be immediately loaded, single full Osseotite implants had to be inserted with a torque of at least 30 Ncm, and splinted implants with a torque of at least 20 Ncm. Immediately loaded implants were provided with non-occluding temporary restorations within 48 hours, which were brought into full occlusion after 2 months. In the early loading group, implants were loaded after 2 months. Definitive restorations were provided 8 months after implant placement in both groups. Outcome measures were prosthesis failures, implant failures and complica-tions, recorded by non-blinded assessors, and peri-implant bone and soft-tissue levels, as evaluated by blinded assessors. RESULTS. Fifty implants were loaded immediately and 54 early. Twelve patients with 24 implants dropped out from the immediate group versus 11 patients with 22 implants from the early loaded group, but all remaining patients were followed up for at least 15 years after loading. One single implant with its provisional crowns and one definitive prothesis failed in the immediate loading group. Seven patients with immediately loaded and two with early loaded implants reported complications. There were no statistically significant differences between groups in terms of implant failures (Fisher’s exact test P = 0.481; diff. =-0.04, 95% CI:-0.16 to 0.08), prosthesis failures (Fisher’s exact test P = 0.226; diff. =-0.08, 95% CI:-0.21 to 0.06), or complications (Fisher’s exact test P = 0.066; diff. =-0.22, 95% CI:-0.41 to 0.01). There were also no statistically significant differences in peri-implant bone (diff. = 0.28 mm, 95%CI:-0.35 to 0.91; P = 0.368) or soft-tissue level changes (diff. = 0.34 mm, 95%CI:-0.32 to 1.00; P = 0.292) between the two groups. Specifically, after 15 years immediately loaded patients had lost an average of 1.75 mm, and early loaded patients an average of 1.44 mm of peri-implant marginal bone. CONCLUSIONS. The long-term prognosis of prostheses supported by both immediately and early-loaded implants seems favourable
High Galactic latitude polarized emission at 1.4 GHz and implications for cosmic microwave background observations
We analyse the polarized emission at 1.4 GHz in a 3x3 deg^2 area at high
Galactic latitude (b ~ -40deg). The region, centred in (RA=5h, Dec=-49deg), was
observed with the Australia Telescope Compact Array radio-interferometer, whose
3-30 arcmin angular sensitivity range allows the study of scales appropriate
for CMB Polarization (CMBP) investigations. The angular behavior of the diffuse
emission is analysed through the E- and B-mode power spectra. These follow a
power law with slopes \beta_E = -1.97 \pm 0.08 and
\beta_B = -1.98 \pm 0.07. The emission is found to be about a factor 25 fainter
than in Galactic plane regions. The comparison of the power spectra with other
surveys indicates that this area is intermediate between strong and negligible
Faraday rotation effects. A similar conclusion can be reached by analysing both
the frequency and Galactic latitude behaviors of the diffuse Galactic emission
of the 408-1411 MHz Leiden survey data. We present an analysis of the Faraday
rotation effects on the polarized power spectra, and find that the observed
power spectra can be enhanced by a transfer of power from large to small
angular scales. The extrapolation of the spectra to 32 and 90GHz of the CMB
window suggests that Galactic synchrotron emission leaves the CMBP E-mode
uncontaminated at 32GHz. The level of the contamination at 90GHz is expected to
be more than 4 orders of magnitude below the CMBP spectrum. Extrapolating to
the relevant angular scales, this region also appears adequate for
investigation of the CMBP B-modes for models with tensor/scalar fluctuation
power ratio T/S>0.01. We also identify polarized point sources in the field,
providing a 9 object list which is complete down to the polarized flux limit of
S^p_lim = 2 mJy.Comment: 13 pages, 11 figures, accepted for publication in MNRA
The embedded clusters DBS 77, 78, 102, and 160-161, and their link with the interstellar medium
Aims. We report on a study of the global properties of some embedded clusters that are found in the fourth quadrant of the Milky Way. We aim to clarify some issues that relate to their location in the Galaxy and their stellar formation processes. Methods. We performed BVI photometric observations in the region of DBS 77, 78, 102, 160, and 161 clusters, and infrared spectroscopy in the DBS 77 region. These were complemented with JHK data from the VVV survey combined with the 2MASS catalogue, and used mid-infrared information from the GLIMPSE catalogue. We also searched for HI data from the SGPS and PMN radio surveys, and previous spectroscopic stellar classifications. The spectroscopic and photometric information enabled us to estimate the spectral classification of the brightest stars for each of the studied regions. On the other hand, we used radio data to investigate the interstellar material parameters and the continuum sources that are probably associated with the respective stellar components. Results. We estimated the basic physical parameters of the clusters (reddening, distance, age, and initial mass function). We searched for HII regions located near to the studied clusters and we analyzed the possible links between them. In the particular case of the DBS 160-161 clusters, we identified the HI bubble B332.5-0.1-42 that is located around them. We found that the mechanical energy injected in to the interstellar medium by the more massive stars of this couple of clusters was enough to generate the bubble.Facultad de Ciencias Astronómicas y GeofísicasInstituto de Astrofísica de La PlataInstituto Argentino de Radioastronomí
Enhancement of electroporation facilitated immunogene therapy via T-reg depletion
Regulatory T cells (T-regs) can negatively impact tumor antigen-specific immune responses after infiltration into tumor tissue. However, depletion of T-regs can facilitate enhanced anti-tumor responses, thus augmenting the potential for immunotherapies. Here we focus on treating a highly aggressive form of cancer using a murine melanoma model with a poor prognosis. We utilize a combination of T-reg depletion and immunotherapy plasmid DNA delivered into the B16F10 melanoma tumor model via electroporation. Plasmids encoding murine granulocyte macrophage colony-stimulating factor and human B71 were transfected with electroporation into the tumor and transient elimination of T-regs was achieved with CD25-depleting antibodies (PC61). The combinational treatment effectively depleted T-regs compared to the untreated tumor and significantly reduced lung metastases. The combination treatment was not effective in increasing the survival, but only effective in suppression of metastases. These results indicate the potential for combining T-reg depletion with immunotherapy-based gene electrotransfer to decrease systemic metastasis and potentially enhance survival
GS100-02-41: a new large HI shell in the outer part of the Galaxy
Massive stars have a profound effect on the surrounding interstellar medium.
They ionize and heat the neutral gas, and due to their strong winds, they swept
the gas up forming large HI shells. In this way, they generate a dense shell
where the physical conditions for the formation of new stars are given. The aim
of this study is to analyze the origin and evolution of the large HI shell
GS100-02-41 and its role in triggering star forming processes.To characterize
the shell and its environs, we carry out a multi-wavelength study. We analyze
he HI 21 cm line, the radio continuum, and infrared emission distributions. The
analysis of the HI data shows an expanding shell structure centred at (l, b) =
(100.6 deg, -2.04 deg) in the velocity range from -29 to -51.7 km/s.
We infer for GS100-02-41, a kinematical distance of 2.8 +/- 0.6 kpc. Several
massive stars belonging to Cep OB1 are located in projection within the large
HI, shell boundaries. The analysis of the radio continuum and infrared data
reveal that there is no continuum counterpart of the HI shell. On the other
hand, three slightly extended radio continuum sources are observed in
projection onto the dense HI shell. From their flux density determinations we
infer that they are thermal in nature. An analysis of the HI emission
distribution in the environs of these sources shows, for each of them, a region
of low emissivity having a good morphological correlation with the ionized gas
in a velocity range similar to the one where GS100-02-41 is detected. The
origin of GS100-02-41 could have been mainly due to the action of the Cep OB1
massive stars located inside the HI shell. The obtained age difference between
the HI shell and the HII regions, together with their relative location, led us
to conclude that the ionizing stars could have been created as a consequence of
the shell evolution.Comment: Accepted for publication in A&
Constraining the regular Galactic Magnetic Field with the 5-year WMAP polarization measurements at 22 GHz
[ABRIDGED] The knowledge of the regular component of the Galactic magnetic
field gives important information about the structure and dynamics of the Milky
Way, as well as constitutes a basic tool to determine cosmic rays trajectories.
It can also provide clear windows where primordial magnetic fields could be
detected. We want to obtain the regular (large scale) pattern of the magnetic
field distribution of the Milky Way that better fits the polarized synchrotron
emission as seen by the 5-year WMAP data at 22 GHz. We have done a systematic
study of a number of Galactic magnetic field models: axisymmetric, bisymmetric,
logarithmic spiral arms, concentric circular rings with reversals and
bi-toroidal. We have explored the parameter space defining each of these models
using a grid-based approach. In total, more than one million models are
computed. The model selection is done using a Bayesian approach. For each
model, the posterior distributions are obtained and marginalised over the
unwanted parameters to obtain the marginal 1-D probability distribution
functions. In general, axisymmetric models provide a better description of the
halo component, although attending to their goodness-of-fit, the rest of the
models cannot be rejected. In the case of disk component, the analysis is not
very sensitive for obtaining the disk large scale structure, because of the
effective available area (less than 8% of the whole map and less than 40% of
the disk). Nevertheless, within a given family of models, the best-fit
parameters are compatible with those found in the literature. The family of
models that better describes the polarized synchrotron halo emission is the
axisymmetric one, with magnetic spiral arms with a pitch angle of ~24 degrees,
and a strong vertical field of 1 microG at z ~ 1 kpc. When a radial variation
is fitted, models require fast variations.Comment: 14 pages, 9 figures. Accepted for publication in A&
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