886 research outputs found
The option to specialize in implantology in Brazil for Chilean dentists.
Curiosity and the continuous advancement of dentistry forces many dentists to specialize, with oral implantology being one of the most indemand programs. Although in Chile there are 12 dental schools that offer this specialty, some of its graduates point out two weaknesses: too many theoretical class hours and too few complex cases
International Congress of Oral Implantologists.: June 2017, Krakow, Poland
Last June, the tenth European International Congress of Oral Implantologists (ICOI Europe Congress) was held in the beautiful city of Krakow, Poland, from June 8-11. This conference brought together more than 330 participants from all over the world, 18 lecturers, 23 scientific works, and 26 workshops in implantology
An adaptive sampling sequential quadratic programming method for nonsmooth stochastic optimization with upper- objective
We propose an optimization algorithm that incorporates adaptive sampling for
stochastic nonsmooth nonconvex optimization problems with upper-
objective functions. Upper- is a weakly concave property that
exists naturally in many applications, particularly certain classes of
solutions to parametric optimization problems, e.g., recourse of stochastic
programming and projection into closed sets. Our algorithm is a stochastic
sequential quadratic programming (SQP) method extended to nonsmooth problems
with upper objectives and is globally convergent in expectation
with bounded algorithmic parameters. The capabilities of our algorithm are
demonstrated by solving a joint production, pricing and shipment problem, as
well as a realistic optimal power flow problem as used in current power grid
industry practice.Comment: arXiv admin note: text overlap with arXiv:2204.0963
COLDz: Karl G. Jansky Very Large Array discovery of a gas-rich galaxy in COSMOS
The broad spectral bandwidth at mm and cm-wavelengths provided by the recent upgrades to the Karl G. Jansky Very Large Array (VLA) has made it possible to conduct unbiased searches for molecular CO line emission at redshifts, z > 1.31. We present the discovery of a gas-rich, star-forming galaxy at z = 2.48, through the detection of CO(1-0) line emission in the COLDz survey, through a sensitive, Ka-band (31 to 39 GHz) VLA survey of a 6.5 square arcminute region of the COSMOS field. We argue that the broad line (FWHM ~570 +/- 80 km/s) is most likely to be CO(1-0) at z=2.48, as the integrated emission is spatially coincident with an infrared-detected galaxy with a photometric redshift estimate of z = 3.2 +/- 0.4. The CO(1-0) line luminosity is L'_CO = (2.2 +/- 0.3) x 10^{10} K km/s pc^2, suggesting a cold molecular gas mass of M_gas ~ (2 - 8)x10^{10}M_solar depending on the assumed value of the molecular gas mass to CO luminosity ratio alpha_CO. The estimated infrared luminosity from the (rest-frame) far-infrared spectral energy distribution (SED) is L_IR = 2.5x10^{12} L_solar and the star-formation rate is ~250 M_solar/yr, with the SED shape indicating substantial dust obscuration of the stellar light. The infrared to CO line luminosity ratio is ~114+/-19 L_solar/(K km/s pc^2), similar to galaxies with similar SFRs selected at UV/optical to radio wavelengths. This discovery confirms the potential for molecular emission line surveys as a route to study populations of gas-rich galaxies in the future
CO(1-0) line imaging of massive star-forming disc galaxies at z=1.5-2.2
We present detections of the CO(J= 1-0) emission line in a sample of four massive star-forming galaxies at z~1.5-2.2 obtained with the Karl G. Jansky Very Large Array (VLA). Combining these observations with previous CO(2-1) and CO(3-2) detections of these galaxies, we study the excitation properties of the molecular gas in our sample sources. We find an average line brightness temperature ratios of R_{21}=0.70+\-0.16 and R_{31}=0.50+\-0.29, based on measurements for three and two galaxies, respectively. These results provide additional support to previous indications of sub-thermal gas excitation for the CO(3-2) line with a typically assumed line ratio R_{31}~0.5. For one of our targets, BzK-21000, we present spatially resolved CO line maps. At the resolution of 0.18'' (1.5 kpc), most of the emission is resolved out except for some clumpy structure. From this, we attempt to identify molecular gas clumps in the data cube, finding 4 possible candidates. We estimate that <40 % of the molecular gas is confined to giant clumps (~1.5 kpc in size), and thus most of the gas could be distributed in small fainter clouds or in fairly diffuse extended regions of lower brightness temperatures than our sensitivity limit
ALLSMOG: an APEX Low-redshift Legacy Survey for MOlecular Gas. I - molecular gas scaling relations, and the effect of the CO/H2 conversion factor
We present ALLSMOG, the APEX Low-redshift Legacy Survey for MOlecular Gas.
ALLSMOG is a survey designed to observe the CO(2-1) emission line with the APEX
telescope, in a sample of local galaxies (0.01 < z < 0.03), with stellar masses
in the range 8.5 < log(M*/Msun) < 10. This paper is a data release and initial
analysis of the first two semesters of observations, consisting of 42 galaxies
observed in CO(2-1). By combining these new CO(2-1) emission line data with
archival HI data and SDSS optical spectroscopy, we compile a sample of low-mass
galaxies with well defined molecular gas masses, atomic gas masses, and
gas-phase metallicities. We explore scaling relations of gas fraction and gas
consumption timescale, and test the extent to which our findings are dependent
on a varying CO/H2 conversion factor. We find an increase in the H2/HI mass
ratio with stellar mass which closely matches semi-analytic predictions. We
find a mean molecular gas fraction for ALLSMOG galaxies of MH2/M* = (0.09 -
0.13), which decreases with stellar mass. We measure a mean molecular gas
consumption timescale for ALLSMOG galaxies of 0.4 - 0.7 Gyr. We also confirm
the non-universality of the molecular gas consumption timescale, which varies
(with stellar mass) from ~100 Myr to ~2 Gyr. Importantly, we find that the
trends in the H2/HI mass ratio, gas fraction, and the non-universal molecular
gas consumption timescale are all robust to a range of recent
metallicity-dependent CO/H2 conversion factors.Comment: 25 pages, 15 figures. Accepted for publication in MNRA
Imaging the molecular gas in a submm galaxy at z = 4.05: cold mode accretion or a major merger?
We present a high resolution (down to 0.18"), multi-transition imaging study
of the molecular gas in the z = 4.05 submillimeter galaxy GN20. GN20 is one of
the most luminous starburst galaxy known at z > 4, and is a member of a rich
proto-cluster of galaxies at z = 4.05 in GOODS-North. We have observed the CO
1-0 and 2-1 emission with the VLA, the CO 6-5 emission with the PdBI
Interferometer, and the 5-4 emission with CARMA. The H_2 mass derived from the
CO 1-0 emission is 1.3 \times 10^{11} (\alpha/0.8) Mo. High resolution imaging
of CO 2-1 shows emission distributed over a large area, appearing as partial
ring, or disk, of ~ 10kpc diameter. The integrated CO excitation is higher than
found in the inner disk of the Milky Way, but lower than that seen in high
redshift quasar host galaxies and low redshift starburst nuclei. The VLA CO 2-1
image at 0.2" resolution shows resolved, clumpy structure, with a few brighter
clumps with intrinsic sizes ~ 2 kpc. The velocity field determined from the CO
6-5 emission is consistent with a rotating disk with a rotation velocity of ~
570 km s^{-1} (using an inclination angle of 45^o), from which we derive a
dynamical mass of 3 \times 10^{11} \msun within about 4 kpc radius. The star
formation distribution, as derived from imaging of the radio synchrotron and
dust continuum, is on a similar scale as the molecular gas distribution. The
molecular gas and star formation are offset by ~ 1" from the HST I-band
emission, implying that the regions of most intense star formation are highly
dust-obscured on a scale of ~ 10 kpc. The large spatial extent and ordered
rotation of this object suggests that this is not a major merger, but rather a
clumpy disk accreting gas rapidly in minor mergers or smoothly from the
proto-intracluster medium. ABSTRACT TRUNCATEDComment: 33 pages, 8 figures, submitted to the ApJ, aas latex forma
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