190 research outputs found
A Dynamic Composition and Stubless Invocation Approach for Information-Providing Services
The automated specification and execution of composite services are important capabilities of service-oriented systems. In practice, service invocation is performed by client components (stubs) that are generated from service descriptions at design time. Several researchers have proposed mechanisms for late binding. They all require an object representation (e.g., Java classes) of the XML data types specified in service descriptions to be generated and meaningfully integrated in the client code at design time. However, the potential of dynamic composition can only be fully exploited if supported in the invocation phase by the capability of dynamically binding to services with previously unknown interfaces. In this work, we address this limitation by proposing a way of specifying and executing composite services, without resorting to previously compiled classes that represent XML data types. Semantic and structural properties encoded in service descriptions are exploited to implement a mechanism, based on the Graphplan algorithm, for the run-time specification of composite service plans. Composite services are then executed through the stubless invocation of constituent services. Stubless invocation is achieved by exploiting structural properties of service descriptions for the run-time generation of messages
3D-fluorescence spectroscopic analysis of HPLC fractionated estuarine fulvic and humic acids
Normothermic and hypothermic oxygenated perfusion for donation after circulatory death in kidney transplantation: Do we pay higher risk of severe infection after transplantation?: A case report
Background: Normothermic and hypothermic oxygenated perfusion for donation after circulatory death in kidney transplantation are becoming popular in Italy, with the purpose of reducing the risk of primary non function and delayed graft function due to the prolonged warm ischemia time. Potential complications related to these procedures are currently under investigation and are continuously emerging with the increasing experience. Post-operative infections - in particular graft arteritis - are a rare complication but determine high risk of mortality and of graft loss. The acute onset of the arterial complications makes it very difficult to find an effective treatment, and early diagnosis is crucial for saving both patient and graft. Prevention of such infections in this particular setting are advisable. Case presentation: We present a patient with an acute arterial rupture after transplantation of a DCD graft treated in-vivo hypothermic oxygenated perfusion. The cause was a severe arteritis of the renal artery caused by Candida krusei and Pseudomonas aeruginosa. We discussed our treatment and we compared it to the other reported series. Conclusion: Fungal infections in DCD transplant may be treacherous and strategies to prevent them should be advocated
Ultrasound Stimulation of Piezoelectric Nanocomposite Hydrogels Boosts Chondrogenic Differentiation in Vitro, in Both a Normal and Inflammatory Milieu
The use of piezoelectric nanomaterials combined with ultrasound stimulation is emerging as a promising approach for wirelessly triggering the regeneration of different tissue types. However, it has never been explored for boosting chondrogenesis. Furthermore, the ultrasound stimulation parameters used are often not adequately controlled. In this study, we show that adipose-tissue-derived mesenchymal stromal cells embedded in a nanocomposite hydrogel containing piezoelectric barium titanate nanoparticles and graphene oxide nanoflakes and stimulated with ultrasound waves with precisely controlled parameters (1 MHz and 250 mW/cm2, for 5 min once every 2 days for 10 days) dramatically boost chondrogenic cell commitment in vitro. Moreover, fibrotic and catabolic factors are strongly down-modulated: proteomic analyses reveal that such stimulation influences biological processes involved in cytoskeleton and extracellular matrix organization, collagen fibril organization, and metabolic processes. The optimal stimulation regimen also has a considerable anti-inflammatory effect and keeps its ability to boost chondrogenesis in vitro, even in an inflammatory milieu. An analytical model to predict the voltage generated by piezoelectric nanoparticles invested by ultrasound waves is proposed, together with a computational tool that takes into consideration nanoparticle clustering within the cell vacuoles and predicts the electric field streamline distribution in the cell cytoplasm. The proposed nanocomposite hydrogel shows good injectability and adhesion to the cartilage tissue ex vivo, as well as excellent biocompatibility in vivo, according to ISO 10993. Future perspectives will involve preclinical testing of this paradigm for cartilage regeneration
To High Redshift and Low Mass : Exploring the Emergence of Quenched Galaxies and Their Environments at 3 < z < 6 in the Ultra-deep JADES MIRI F770W Parallel
We present the robust selection of quiescent (QG) and post-starburst (PSB) galaxies using ultra-deep NIRCam and MIRI imaging from the JWST Advanced Deep Extragalactic Survey (JADES). Key to this is MIRI 7.7 mu m imaging which breaks the degeneracy between old stellar populations and dust attenuation at 3 < z < 6 by providing rest-frame J-band. Using this, we identify 23 passively evolving galaxies in UVJ color space in a mass-limited (log M-star/M-circle dot >= 8.5) sample over 8.8 arcmin2. Evaluation of this selection with and without 7.7 mu m shows that dense wavelength coverage with NIRCam (8-11 bands including 1-4 medium-bands) can compensate for lacking the J-band anchor, meaning that robust selection of high-redshift QGs is possible with NIRCam alone. Our sample is characterized by rapid quenching timescales (similar to 100-600 Myr) with formation redshifts z(f )less than or similar to 8.5 and includes a potential record-holding massive QG at z(phot)=5.33(-0.17)(+0.16) and two QGs with evidence for significant residual dust content (A(V)similar to 1-2). In addition, we present a large sample of 12 log M-star/M-circle dot=8.5-9.5 PSBs, demonstrating that UVJ selection can be extended to low mass. Analysis of the environment of our sample reveals that the group known as the Cosmic Rose contains a massive QG and a dust-obscured star-forming galaxy (a so-called Jekyll and Hyde pair) plus three additional QGs within similar to 20 kpc. Moreover, the Cosmic Rose is part of a larger overdensity at z similar to 3.7 which contains 7/12 of our low-mass PSBs. Another 4 low-mass PSBs are members of an overdensity at z similar to 3.4; this result strongly indicates low-mass PSBs are preferentially associated with overdense environments at z>3
JADES : the emergence and evolution of Ly α emission and constraints on the intergalactic medium neutral fraction
The rest-frame UV recombination emission line Lyα can be powered by ionising photons from young massive stars in star-forming galaxies, but the fact that it can be resonantly scattered by neutral gas complicates its interpretation. For reionisation-era galaxies, a neutral intergalactic medium will scatter Lyα from the line of sight, making Lyα a useful probe of the neutral fraction evolution. Here, we explore Lyα in JWST/NIRSpec spectra from the ongoing JADES programme, which targets hundreds of galaxies in the well-studied GOODS-S and GOODS-N fields. These sources are UV-faint (-20.4 < MUV <-16.4) and thus represent a poorly explored class of galaxy. We fitted the low spectral resolution spectra (R ∼ 100) of a subset of 84 galaxies in GOODS-S with zspec > 5.6 (as derived with optical lines) with line and continuum models to search for significant line emission. Through exploration of the R100 data, we find evidence for Lyα in 17 sources. This sample allowed us to place observational constraints on the fraction of galaxies with Lyα emission in the redshift range 5.6 < z < 7.5, with a decrease from z = 6 to z = 7. We also find a positive correlation between the Lyα equivalent width and MUV, as seen in other samples. We used these results to estimate the neutral gas fraction at z ∼ 7, and our estimates are in agreement with previous results (XHI ∼ 0.5-0.9)
JADES Data Release 3: NIRSpec/Microshutter Assembly Spectroscopy for 4000 Galaxies in the GOODS Fields
We present the third data release of the JWST Advanced Deep Extragalactic Survey (JADES), providing both imaging and spectroscopy in the two GOODS fields. Spectroscopy consists of medium-depth and deep NIRSpec/microshutter assembly spectra of 4000 targets, covering the spectral range 0.6–5.3 μm and observed with both the low-dispersion prism (R = 30–300) and all three medium-resolution gratings (R = 500–1500). We describe the observations, data reduction, sample selection, and target allocation. We measured 2375 redshifts (2053 from multiple emission lines); our targets span the range from z = 0.5 up to z = 13, including 404 at z > 5. The data release includes 2D and 1D fully reduced spectra, with slit-loss corrections and background subtraction optimized for point sources. We also provide redshifts and signal-to-noise ratio > 5 emission-line flux catalogs for the prism and grating spectra, and concise guidelines on how to use these data products. Alongside spectroscopy, we are also publishing fully calibrated NIRCam imaging, which enables studying the JADES sample with the combined power of imaging and spectroscopy. Together, these data provide the largest statistical sample to date to characterize the properties of galaxy populations in the first billion years after the Big Bang
Ionised gas kinematics and dynamical masses of z & 6 galaxies from JADES/NIRSpec high-resolution spectroscopy
We explore the kinematic gas properties of six 5.5 < z < 7.4 galaxies in the JWST Advanced Deep Extragalactic Survey (JADES), using high-resolution JWST/NIRSpec multi-object spectroscopy of the rest-frame optical emission lines [Oiii] and Hα. The objects are small and of low stellar mass (∼1 kpc; M∗ ∼ 107−9 M ), less massive than any galaxy studied kinematically at z > 1 thus far. The cold gas masses implied by the observed star formation rates are about ten times higher than the stellar masses. We find that their ionised gas is spatially resolved by JWST, with evidence for broadened lines and spatial velocity gradients. Using a simple thin-disc model, we fit these data with a novel forward-modelling software that accounts for the complex geometry, point spread function, and pixellation of the NIRSpec instrument. We find the sample to include both rotation- and dispersion-dominated structures, as we detect velocity gradients of v(re) ∼ 100−150 km s−1, and we find velocity dispersions of σ0 ∼ 30−70 km s−1 that are comparable to those at cosmic noon. The dynamical masses implied by these models (Mdyn ∼ 109−10 M ) are higher than the stellar masses by up to a factor 40, and they are higher than the total baryonic mass (gas + stars) by a factor of ∼3. Qualitatively, this result is robust even if the observed velocity gradients reflect ongoing mergers rather than rotating discs. Unless the observed emission line kinematics is dominated by outflows, this implies that the centres of these galaxies are dominated by dark matter or that star formation is three times less efficient, leading to higher inferred gas masses
To High Redshift and Low Mass: Exploring the Emergence of Quenched Galaxies and Their Environments at 3 < z < 6 in the Ultra-deep JADES MIRI F770W Parallel
© 2024. The Author(s). Published by the American Astronomical Society. This is an open access article distributed under the Creative Commons Attribution License, to view a copy of the license, see: https://creativecommons.org/licenses/by/4.0/We present the robust selection of high-redshift quiescent galaxies (QG) and poststarburst (PSB) galaxies using ultra-deep NIRCam and MIRI imaging from the JWST Advanced Deep Extragalactic Survey (JADES). At 3 3.Peer reviewe
To high redshift and low mass: exploring the emergence of quenched galaxies and their environments at in the ultra-deep JADES MIRI F770W parallel
We present the robust selection of quiescent (QG) and post-starburst (PSB)
galaxies using ultra-deep NIRCam and MIRI imaging from the JWST Advanced Deep
Extragalactic Survey (JADES). Key to this is MIRI 7.7m imaging which
breaks the degeneracy between old stellar populations and dust attenuation at
by providing rest-frame -band. Using this, we identify 23 passively
evolving galaxies in UVJ color space in a mass-limited (log
) sample over 8.8 arcmin. Evaluation of this
selection with and without 7.7m shows that dense wavelength coverage
with NIRCam ( bands including medium-bands) can compensate for
lacking the band anchor, meaning that robust selection of high-redshift QGs
is possible with NIRCam alone. Our sample is characterized by rapid quenching
timescales ( Myr) with formation redshifts
and includes a potential record-holding massive QG at and two QGs with evidence for significant residual
dust content (). In addition, we present a large sample of 12
log PSBs, demonstrating that UVJ selection can be
extended to low mass. Analysis of the environment of our sample reveals that
the group known as the Cosmic Rose contains a massive QG and a dust-obscured
star-forming galaxy (a so-called Jekyll and Hyde pair) plus three additional
QGs within kpc. Moreover, the Cosmic Rose is part of a larger
overdensity at which contains 7/12 of our low-mass PSBs. Another 4
low-mass PSBs are members of an overdensity at ; this result strongly
indicates low-mass PSBs are preferentially associated with overdense
environments at .Comment: 27 pages, 10 figures, 2 tables (not including appendices or
references). Submitted to ApJ. Comments welcome
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