205 research outputs found

    An Hybrid, Qos-Aware Discovery of Semantic Web Services Using Constraint Programming

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    Most Semantic Web Services discovery approaches are not well suited when using complex relational, arithmetic and logical expressions, because they are usually based on Description Logics. Moreover, these kind of expressions usually appear when discovery is performed including Quality-of-Service conditions. In this work, we present an hybrid discovery process for Semantic Web Services that takes care of QoS conditions. Our approach splits discovery into stages, using different engines in each one, depending on its search nature. This architecture is extensible and loosely coupled, allowing the addition of discovery engines at will. In order to perform QoS-aware discovery, we propose a stage that uses Constraint Programming, that allows to use complex QoS conditions within discovery queries. Furthermore, it is possible to obtain the optimal offer that fulfills a given demand using this approach.Comisión Interministerial de Ciencia y Tecnología TIN2006-0047

    Effect of Inhibition of the Lysophosphatidic Acid Receptor 1 on Metastasis and Metastatic Dormancy in Breast Cancer

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    Background Previous studies identified the human nonmetastatic gene 23 (NME1, hereafter Nm23-H1) as the first metastasis suppressor gene. An inverse relationship between Nm23-H1 and expression of lysophosphatidic acid receptor 1 gene (LPAR1, also known as EDG2 or hereafter LPA1) has also been reported. However, the effects of LPA1 inhibition on primary tumor size, metastasis, and metastatic dormancy have not been investigated. Methods The LPA1 inhibitor Debio-0719 or LPA1 short hairpinned RNA (shRNA) was used. Primary tumor size and metastasis were investigated using the 4T1 spontaneous metastasis mouse model and the MDA-MB-231T experimental metastasis mouse model (n = 13 mice per group). Proliferation and p38 intracellular signaling in tumors and cell lines were determined by immunohistochemistry and western blot to investigate the effects of LPA1 inhibition on metastatic dormancy. An analysis of variance-based two-tailed t test was used to determine a statistically significant difference between treatment groups. Results In the 4T1 spontaneous metastasis mouse model, Debio-0719 inhibited the metastasis of 4T1 cells to the liver (mean = 25.2 liver metastases per histologic section for vehicle-treated mice vs 6.8 for Debio-0719-treated mice, 73.0% reduction, P < .001) and lungs (mean = 6.37 lesions per histologic section for vehicle-treated mice vs 0.73 for Debio-0719-treated mice, 88.5% reduction, P < .001), with no effect on primary tumor size. Similar results were observed using the MDA-MB-231T experimental pulmonary metastasis mouse model. LPA1 shRNA also inhibited metastasis but did not affect primary tumor size. In 4T1 metastases, but not primary tumors, expression of the proliferative markers Ki67 and pErk was reduced by Debio-0719, and phosphorylation of the p38 stress kinase was increased, indicative of metastatic dormancy. Conclusion The data identify Debio-0719 as a drug candidate with metastasis suppressor activity, inducing dormancy at secondary tumor site

    COSMOS2020: Exploring the dawn of quenching for massive galaxies at 3 < z < 5 with a new colour selection method

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    We select and characterise a sample of massive (log(M/_{*}/M)>10.6_{\odot})>10.6) quiescent galaxies (QGs) at 3<z<53<z<5 in the latest COSMOS2020 catalogue. QGs are selected using a new rest-frame colour selection method, based on their probability of belonging to the quiescent group defined by a Gaussian Mixture Model (GMM) trained on rest-frame colours (NUVU,UV,VJNUV-U, U-V, V-J) of similarly massive galaxies at 2<z<32<z<3. We calculate the quiescent probability threshold above which a galaxy is classified as quiescent using simulated galaxies from the SHARK semi-analytical model. We find that at z3z\geq3 in SHARK, the GMM/NUVUVJNUVU-VJ method out-performs classical rest-frame UVJUVJ selection and is a viable alternative. We select galaxies as quiescent based on their probability in COSMOS2020 at 3<z<53<z<5, and compare the selected sample to both UVJUVJ and NUVrJNUVrJ selected samples. We find that although the new selection matches UVJUVJ and NUVrJNUVrJ in number, the overlap between colour selections is only 5080%\sim50-80\%, implying that rest-frame colour commonly used at lower redshifts selections cannot be equivalently used at z>3z>3. We compute median rest-frame SEDs for our sample and find the median quiescent galaxy at 3<z<53<z<5 has a strong Balmer/4000 Angstrom break, and residual NUVNUV flux indicating recent quenching. We find the number densities of the entire quiescent population (including post-starbursts) more than doubles from 3.5±2.2×1063.5\pm2.2\times10^{-6} Mpc3^{-3} at 4<z<54<z<5 to 1.4±0.4×1051.4\pm0.4\times10^{-5} Mpc3^{-3} at 3<z<43<z<4, confirming that the onset of massive galaxy quenching occurs as early as 3<z<53<z<5.Comment: 19 pages, 10 figures + appendix. Accepted for publication in AJ. Both the GMM model and code to calculate quiescent probabilities from rest frame flux densities are made available online at https://github.com/kmlgould/GMM-quiescen

    A digitally-augmented ground space with timed visual cues for facilitating forearm crutches’ mobility

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    Persuasive technologies for physical rehabilitation have been pro posed in a number of different health interventions such as post-stroke gait rehabilitation. We propose a new persuasive system, called Augmented Crut ches, aimed at helping people to walk with crutches. People with injuries, or with any sort of mobility problem typically use assistive devices such as crut ches, walkers or canes in order to be able to walk more independently. However, walking with crutches is a learning skill that needs continuous repetition and constant attention to detail in order to walk correctly with them and without suffering negative consequences, such as falls or injuries. In close collaboration with therapists, we identify the main issues that patients face when walking with crutches. These vary from person to person, but the most common and hardest challenges are the position and coordination of the crutches. Augmented Crut ches studies human behavior aspects in these situations and augments the ground space around the user with digital visual cues where timing is the most important factor, without the need for a constant therapist providing manual help. This is performed through a mini-projector connected to a smartphone, worn by the user in a portable, lightweight manner. Our system helps people to learn how to walk using crutches with increased self-confidence and motivation. Additionally, our work identifies timing, controllability and awareness as the key design dimensions for the successful creation of persuasive, interactive experiences for learning how to walk with crutches.info:eu-repo/semantics/publishedVersio

    JWST and ALMA discern the assembly of structural and obscured components in a high-redshift starburst galaxy

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    We present observations and analysis of the starburst, PACS-819, at z=1.45 (M=1010.7M_*=10^{10.7} M_{ \odot}), using high-resolution (0.10^{\prime \prime}.1; 0.8 kpc) ALMA and multi-wavelength JWST images from the COSMOS-Web program. Dissimilar to HST/ACS images in the rest-frame UV, the redder NIRCam and MIRI images reveal a smooth central mass concentration and spiral-like features, atypical for such an intense starburst. Through dynamical modeling of the CO J=5--4 emission with ALMA, PACS-819 is rotation-dominated thus has a disk-like nature. However, kinematic anomalies in CO and asymmetric features in the bluer JWST bands (e.g., F150W) support a more disturbed nature likely due to interactions. The JWST imaging further enables us to map the distribution of stellar mass and dust attenuation, thus clarifying the relationships between different structural components, not discernable in the previous HST images. The CO J = 5 -- 4 and FIR dust continuum emission are co-spatial with a heavily-obscured starbursting core (<1 kpc) which is partially surrounded by much less obscured star-forming structures including a prominent arc, possibly a tidally-distorted dwarf galaxy, and a clump, either a sign of an ongoing violent disk instability or a recently accreted low-mass satellite. With spatially-resolved maps, we find a high molecular gas fraction in the central area reaching 3\sim3 (MgasM_{\text{gas}}/MM_*) and short depletion times (Mgas/SFRM_{\text{gas}}/SFR\sim 120 Myrs) across the entire system. These observations provide insights into the complex nature of starbursts in the distant universe and underscore the wealth of complementary information from high-resolution observations with both ALMA and JWST.Comment: 18 pages, 12 figures, Submitted to Ap

    The Web Epoch of Reionization Lyman-α\alpha Survey (WERLS) I. MOSFIRE Spectroscopy of z78\mathbf{z \sim 7-8} Lyman-α\alpha Emitters

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    We present the first results from the Web Epoch of Reionization Lyman-α\alpha Survey (WERLS), a spectroscopic survey of Lyman-α\alpha emission using Keck I/MOSFIRE and LRIS. WERLS targets bright (J<26J<26) galaxy candidates with photometric redshifts of 5.5z85.5\lesssim z \lesssim 8 selected from pre-JWST imaging embedded in the Epoch of Reionization (EoR) within three JWST deep fields: CEERS, PRIMER, and COSMOS-Web. Here, we report 11 z78z\sim7-8 Lyman-α\alpha emitters (LAEs; 3 secure and 8 tentative candidates) detected in the first five nights of WERLS MOSFIRE data. We estimate our observed LAE yield is 13\sim13%, broadly consistent with expectations assuming some loss from redshift uncertainty, contamination from sky OH lines, and that the Universe is approximately half-ionized at this epoch, whereby observable Lyman-α\alpha emission is unlikely for galaxies embedded in a neutral intergalactic medium. Our targets are selected to be UV-bright, and span a range of absolute UV magnitudes with 23.1<MUV<19.8-23.1 < M_{\text{UV}} < -19.8. With two LAEs detected at z=7.68z=7.68, we also consider the possibility of an ionized bubble at this redshift. Future synergistic Keck+JWST efforts will provide a powerful tool for pinpointing beacons of reionization and mapping the large scale distribution of mass relative to the ionization state of the Universe.Comment: 27 pages, 8 figures; ApJ submitte

    COSMOS-Web: Intrinsically Luminous z\gtrsim10 Galaxy Candidates Test Early Stellar Mass Assembly

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    We report the discovery of 15 exceptionally luminous 10z1410\lesssim z\lesssim14 candidate galaxies discovered in the first 0.28 deg2^2 of JWST/NIRCam imaging from the COSMOS-Web Survey. These sources span rest-frame UV magnitudes of 20.5>MUV>22-20.5>M_{\rm UV}>-22, and thus constitute the most intrinsically luminous z10z\gtrsim10 candidates identified by JWST to-date. Selected via NIRCam imaging with Hubble ACS/F814W, deep ground-based observations corroborate their detection and help significantly constrain their photometric redshifts. We analyze their spectral energy distributions using multiple open-source codes and evaluate the probability of low-redshift solutions; we conclude that 12/15 (80%) are likely genuine z10z\gtrsim10 sources and 3/15 (20%) likely low-redshift contaminants. Three of our z12z\sim12 candidates push the limits of early stellar mass assembly: they have estimated stellar masses 5×109M\sim5\times10^{9}\,M_\odot, implying an effective stellar baryon fraction of ϵ0.20.5\epsilon_{\star}\sim0.2-0.5, where ϵM/(fbMhalo)\epsilon_{\star}\equiv M_{\star}/(f_{b}M_{halo}). The assembly of such stellar reservoirs is made possible due to rapid, burst-driven star formation on timescales <<100\,Myr where the star-formation rate may far outpace the growth of the underlying dark matter halos. This is supported by the similar volume densities inferred for M1010MM_\star\sim10^{10}\,M_\odot galaxies relative to M109MM_\star\sim10^{9}\,M_\odot -- both about 10610^{-6} Mpc3^{-3} -- implying they live in halos of comparable mass. At such high redshifts, the duty cycle for starbursts would be of order unity, which could cause the observed change in the shape of the UVLF from a double powerlaw to Schechter at z8z\approx8. Spectroscopic redshift confirmation and ensuing constraints of their masses will be critical to understanding how, and if, such early massive galaxies push the limits of galaxy formation in Λ\LambdaCDM.Comment: 30 pages, 9 figures; ApJ submitte

    CEERS Spectroscopic Confirmation of NIRCam-Selected z > 8 Galaxy Candidates with JWST/NIRSpec: Initial Characterization of their Properties

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    We present JWST NIRSpec spectroscopy for 11 galaxy candidates with photometric redshifts of z913z\simeq9-13 and MUV[21,18]M_{\rm\,UV} \in[-21,-18] newly identified in NIRCam images in the Cosmic Evolution Early Release Science (CEERS) Survey. We confirm emission line redshifts for 7 galaxies at z=7.7628.998z=7.762-8.998 using spectra at 15μ\sim1-5\mum either with the NIRSpec prism or its three medium resolution gratings. For z9z\simeq9 photometric candidates, we achieve a high confirmation rate of \simeq90\%, which validates the classical dropout selection from NIRCam photometry. No robust emission lines are identified in three galaxy candidates at z>10z>10, where the strong [OIII] and Hβ\beta lines would be redshifted beyond the wavelength range observed by NIRSpec, and the Lyman-α\alpha continuum break is not detected with the current sensitivity. Compared with HST-selected bright galaxies (MUV22M_{\rm\,UV}\simeq-22) that are similarly spectroscopically confirmed at z8z\gtrsim8, these NIRCam-selected galaxies are characterized by lower star formation rates (SFR4M\simeq4\,M_{\odot}~yr1^{-1}) and lower stellar masses (108M\simeq10^{8}\,M_{\odot}), but with higher [OIII]+Hβ\beta equivalent widths (\simeq1100A˚\r{A}), and elevated production efficiency of ionizing photons (log(ξion/Hzerg1)25.8\log(\xi_{\rm\,ion}/{\rm\,Hz\,erg}^{-1})\simeq25.8) induced by young stellar populations (<10<10~Myrs) accounting for 20%\simeq20\% of the galaxy mass, highlighting the key contribution of faint galaxies to cosmic reionization. Taking advantage of the homogeneous selection and sensitivity, we also investigate metallicity and ISM conditions with empirical calibrations using the [OIII]/Hβ\beta ratio. We find that galaxies at z89z\sim8-9 have higher SFRs and lower metallicities than galaxies at similar stellar masses at z26z\sim2-6, which is generally consistent with the current galaxy formation and evolution models.Comment: 21 pages, 11 figures, 2 tables. Submitted to ApJL Focus Issu
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