We have analysed 18 ALMA continuum maps in Bands 6 and 7, with rms down to 7.8 µJy, to derive differential number counts down to 60 µJy and 100 µJy at λ = 1.3 mm and λ = 1.1 mm, respectively. Furthermore, the non-detection of faint sources in the deepest ALMA field enabled us to set tight upper limits on the number counts down to 30 µJy. This is a factor of four deeper than the currently most stringent upper limit. The area covered by the combined fields is 9.5 × 10 −4 deg 2 at 1.1 mm and 6.6 × 10 −4 deg 2 at 1.3 mm. With respect to previous works, we improved the source extraction method by requiring that the dimension of the detected sources be consistent with the beam size. This method enabled us to remove spurious detections that have plagued the purity of the catalogues in previous studies. We detected 50 faint sources (at fluxes <1 mJy) with signal-to-noise (S/N) >3.5 down to 60 µJy, hence improving the statistics by a factor of four relative to previous studies. The inferred differential number counts are dN/d(Log 10 S ) = 1 × 10 5 deg 2 at a 1.1 mm flux S λ = 1.1 mm = 130 µJy, and dN/d(Log 10 S ) = 1.1×10 5 deg 2 at a 1.3 mm flux S λ = 1.3 mm = 60 µJy. At the faintest flux limits probed by our data, i.e. 30 µJy and 40 µJy, we obtain upper limits on the differential number counts of dN/d(Log 10 S ) < 7 × 10 5 deg 2 and dN/d(Log 10 S ) < 3×10 5 deg 2 , respectively. Determining the fraction of cosmic infrared background (CIB) resolved by the ALMA observations was hampered by the large uncertainties plaguing the CIB measurements (a factor of four in flux). However, our results provide a new lower limit to CIB intensity of 17.2 Jy deg −2 at 1.1 mm and of 12.9 Jy deg −2 at 1.3 mm. Moreover, the flattening of the integrated number counts at faint fluxes strongly suggests that we are probably close to the CIB intensity. Our data imply that galaxies with star formation rate (SFR) < 40 M /yr certainly contribute less than 50% to the CIB (and probably a much lower percentage) while more than 50% of the CIB must be produced by galaxies with SFR > 40 M /yr. The differential number counts are in nice agreement with recent semi-analytical models of galaxy formation even as low as our faint fluxes. Consequently, this supports the galaxy evolutionary scenarios and assumptions made in these models.

We present spatially resolved Atacama Large Millimeter/submillimeter Array (ALMA) [Cii] observations of the z = 4.7555 submillimetre galaxy, ALESS 73.1. Our 0. 5 FWHM map resolves the [Cii] emitting gas which is centred close to the active galactic nucleus (AGN). The gas kinematics are dominated by rotation but with high turbulence, v rot /σ int ∼ 3.1, and a Toomre Q parameter <1 throughout the disk. By fitting three independent thin rotating disk models to our data, we derive a total dynamical mass of 3 ± 2 × 10 10 M . This is close to the molecular gas mass derived from previous CO(2-1) observations, and implies a CO to H 2 conversion factor α CO < 2.3 M (K km s −1 pc 2 ) −1 . The mass budget also constrains the stellar mass to <3.1 × 10 10 M , and entails a gas fraction of f gas 0.4. The diameter of the dust continuum emission is <2 kpc, while the star-formation rate is as high as 1000 M yr −1 . Combined with our stellar mass constraint, this implies an extreme specific star formation rate >80 Gyr −1 , especially since there are no clear indications of recent merger activity. Finally, our high signal-to-noise [Cii] measurement revises the observed [Nii]/[Cii] ratio, which suggests a close to solar metallicity, unless the [Cii] flux contains significant contributions from Hii regions. Our observations suggest that ALESS73.1 is a nascent galaxy undergoing its first major burst of star formation, embedded within an unstable but metal-rich gas disk.

We present near-infrared observations of 42 gravitationally lensed galaxies obtained in the framework of the KMOS Lensed Emission Lines and VElocity Review (KLEVER) Survey, a programme aimed at investigating the spatially resolved properties of the ionized gas in 1.2 &lt; z &lt; 2.5 galaxies by means of a full coverage of the YJ, H, and K near-infrared bands. Detailed metallicity maps and gradients are derived for a subsample of 28 galaxies from reconstructed source-plane emission-line maps, exploiting the variety of different emission-line diagnostics provided by the broad wavelength coverage of the survey. About $85 {{\, per\ cent}}$ of these galaxies are characterized by metallicity gradients shallower than $0.05\ \rm dex\, kpc^{-1}$ and $89{{\ \rm per\ cent}}$ are consistent with a flat slope within 3σ ($67{{\ \rm per\ cent}}$ within 1σ), suggesting a mild evolution with cosmic time. In the context of cosmological simulations and chemical evolution models, the presence of efficient feedback mechanisms and/or extended star formation profiles on top of the classical ‘inside-out’ scenario of mass assembly is generally required to reproduce the observed flatness of the metallicity gradients beyond z ∼ 1. Three galaxies with significantly (&gt;3σ) ‘inverted’ gradients are also found, showing an anticorrelation between metallicity and star formation rate density on local scales, possibly suggesting recent episodes of pristine gas accretion or strong radial flows in place. Nevertheless, the individual metallicity maps are characterized by a variety of different morphologies, with flat radial gradients sometimes hiding non-axisymmetric variations on kpc scales, which are washed out by azimuthal averages, especially in interacting systems or in those undergoing local episodes of recent star formation.

Lower back pain (LBP) occurs in 80% of adults in their lifetime; resulting in LBP being one of the biggest causes of disability worldwide. Chronic LBP has been linked to the degeneration of the intervertebral disc (IVD). The current treatments for chronic back pain only provide alleviation of symptoms through pain relief, tissue removal, or spinal fusion; none of which target regenerating the degenerate IVD. As nucleus pulposus (NP) degeneration is thought to represent a key initiation site of IVD degeneration, cell therapy that specifically targets the restoration of the NP has been reviewed here. A literature search to quantitatively assess all cell types used in NP regeneration was undertaken. With key cell sources: NP cells; annulus fibrosus cells; notochordal cells; chondrocytes; bone marrow mesenchymal stromal cells; adiposederived stromal cells; and induced pluripotent stem cells extensively analyzed for their regenerative potential of the NP. This review highlights: accessibility; expansion capability in vitro; cell survival in an IVD environment; regenerative potential; and safety for these key potential cell sources. In conclusion, while several potential cell sources have been proposed, iPSC may provide the most promising regenerative potential.

No abstract