182 research outputs found
Galaxy Evolution in the Cluster Abell 85: New Insights from the Dwarf Population
We present the first results of a new spectroscopic survey of the cluster
Abell 85 targeting 1466 candidate cluster members within the central 1
deg of the cluster and having magnitudes using VIMOS/VLT and
HYDRA/WIYN. A total of 520 galaxies are confirmed as either relaxed cluster
members or part of an infalling population. A significant fraction are low
mass; the median stellar mass of the sample is , and 25%
have stellar masses below (i.e. 133 dwarf galaxies). We also
identify seven active galactic nuclei (AGN), four of which reside in dwarf host
galaxies. We probe the evolution of star formation rates, based on H
emission and continuum modeling, as a function of both mass and environment. We
find that more star forming galaxies are observed at larger clustercentric
distances, while infalling galaxies show evidence for recently enhanced star
forming activity. Main sequence galaxies, defined by their continuum star
formation rates, show different evolutionary behavior based on their mass. At
the low mass end, the galaxies have had their star formation recently quenched,
while more massive galaxies show no significant change. The timescales probed
here favor fast quenching mechanisms, such as ram-pressure stripping. Galaxies
within the green valley, defined similarly, do not show evidence of quenching.
Instead, the low mass galaxies maintain their levels of star forming activity,
while the more massive galaxies have experienced a recent burst.Comment: 15 pages, 10 figures, accepted for publication in MNRA
Starburst Galaxies in Cluster-feeding Filaments Unveiled by Spitzer
We report the first direct detection with Spitzer of galaxy filaments. Using Spitzer and ancillary optical data, we have discovered two filamentary structures in the outskirts of the cluster Abell 1763. Both filaments point toward Abell 1770, which lies at the same redshift as Abell 1763 (z = 0.23), at a projected distance of ~13 Mpc. The X-ray cluster emission is elongated along the same direction. Most of the far-infrared emission is powered by star formation. According to the optical spectra, only one of the cluster members is classified as an active galactic nucleus. Star formation is clearly enhanced in galaxies along the filaments: the fraction of starburst galaxies in the filaments is more than twice than that in other cluster regions. We speculate that these filaments are feeding the cluster Abell 1763 by the infall of galaxies and galaxy groups. Evidence for one of these groups is provided by the analysis of galaxy kinematics in the central cluster region
Spitzer observations of Abell 1763 - I: infrared and optical photometry
We present a photometric analysis of the galaxy cluster Abell 1763 at visible
and infrared wavelengths. Included are fully reduced images in r', J, H, and Ks
obtained using the Palomar 200in telescope, as well as the IRAC and MIPS images
from Spitzer. The cluster is covered out to approximately 3 virial radii with
deep 24um imaging (a 5? depth of 0.2 mJy). This same field of 40' by 40' is
covered in all four IRAC bands as well as the longer wavelength MIPS bands (70
and 160um). The r' imaging covers 0.8 deg2 down to 25.5 magnitudes, and
overlaps with most of the MIPS field of view. The J, H, Ks images cover the
cluster core and roughly half of the filament galaxies, which extend towards
the neighboring cluster, Abell 1770. This first, in a series of papers on Abell
1763, discusses the data reduction methods and source extraction techniques
used for each dataset. We present catalogs of infrared (IR) sources (with 24
and/or 70um emission) and their corresponding emission in the optical (u', g',
r', i', z'), and Near- to Far-IR (J, H, Ks, IRAC, and MIPS 160um). We provide
the catalogs and reduced images to the community through the NASA/IPAC Infrared
Science Archive (IRSA).Comment: 25 pages, 16 figure
Surgical management of the acromegalic face: Could the aesthetic improvement of the face influence the patient's QoL? Combined surgical approach
Acromegaly is a chronic and progressive disease related to a disorder of growth hormone production. It may present with a variety of clinical signs and a dento-facial deformity and this results in a loss of self-esteem and a reduction of Quality of Life. Presentation of case: A 38-yearsâold male patient, affected by acromegaly with class III malocclusion, noticeable nose deformity and macroglossia was treated. Bi-maxillary orthognathic surgery and partial glossectomy have been performed in one-step surgey. Open rhinoplasty was done in a second step. Both dento-skeletal class III and restoration of the facial appearance have been solved. Dento-skeletal class III was completly solved together with the restoration of the facial appearance and the patient satisfaction has been achieved. Conclusions: This case report describes the successful and stable treatment of an adult patient affected by acromegaly
Cardiac Autonomic Control and Neural Arousal as Indexes of Fatigue in Professional Bus Drivers
Background: Bus driving is a mentally demanding activity that requires prolonged attention to ensure safety. The aim of the study was to assess mental fatigue caused by driving a public bus and to find a profile of workers at higher risk. Methods: We evaluated changes of critical flicker fusion (CFF) (index of central arousal) and heart rate variability (HRV) (index of autonomic balance) in a 6-hour driving shift on a real route, in 31 professional bus drivers, and we tested the influence of personal factors such as sleep quality, BMI, and age. Paired t test was used to test differences of CFF and HRV between both initial and final phase of driving, while multiple linear regression tested the influence of personal variables on the indexes of mental fatigue. Results: Results showed that CFF significantly decreased after 6 hours of bus driving (41.91 Hz, sd 3.31 vs. 41.15 Hz, sd 3.15; p = 0.041), and heart rate significantly decreased in the final phase of driving, with respect to the initial phase (85 vs. 78 bpm, p = 0.027). Increasing age (beta =-0.729, p = 0.022), risk of obstructive sleep apnea syndrome (beta =-0.530, p = 0.04), and diurnal sleepiness (beta =-0.406, p = 0.017) showed a significant effect on influencing mental fatigue. Conclusion: Elderly drivers at higher risk of sleep disorders are more prone to mental fatigue, when exposed to driving activity. Monitoring indexes of central arousal and autonomic balance, coupled with the use of structured questionnaires can represent a useful strategy to detect profile of workers at higher risk of mental fatigue in such duty
Explosive activity of the summit cone of Piton de la Fournaise volcano (La RĂ©union island): A historical and geological review
International audienceSummit explosive activity and collapses that form pit craters and calderas represent major volcanic hazards on a dominantly effusive, frequently active volcano like Piton de la Fournaise. Only three summit collapse events (1986, 2002, 2007) have been recorded since the foundation of the Piton de la Fournaise volcano observatory (OVPF) in 1979, and two of them (1986 and 2007) were associated with weak phreatic activity. At Piton de la Fournaise, the normal explosive activity consists of short-lived and mild (< 20 m-high) lava fountains, which quickly evolve into strombolian activity during the eruptions. Based on comprehensive literature review and high-resolution image analysis of surface outcrops and summit caldera walls, we reconstructed the time distribution of recent explosive events (phreatomagmatic; phreatic) and their link with summit collapses and lateral (flank) effusive eruptions. In historical time (post-1640 CE), we recognise two main clusters of explosive events. Frequent and violent phreatomagmatic to phreatic explosions occurred during the oldest cluster (1708â1878) and alternated with long-lasting periods (years to decades) of summit effusive activity. In contrast, scarce, and on average, weak explosions occurred during the youngest cluster (1897â2012), when discrete and short-lived (< 6 months) effusive eruptions represent the main eruptive dynamics. Historical summit collapses (pit craters and caldera), all localised at the top of the summit cone, were related to voluminous lateral eruptions and were followed by a significant decrease in eruptive rate. However, magma draining during lateral eruptions was not systematically associated with summit collapses or explosions. The long-lasting occurrence of magma at very shallow depth below the volcano summit, followed by a rapid lateral drainage, apparently represents a critical condition favouring magmaâgroundwater interaction to produce explosive activity. The prehistoric growth of the Piton de la Fournaise summit cone results chiefly from long-lasting to continuous activity, centred below its western side (Bory crater containing lava lakes). High lava fountains, long-lasting effusive activity, lava lakes, ash plumes and block ejections were common types of eruptive dynamics in the historical past, between 1640 and 1878. In this perspective, short-lived, small volume eruptions and long pauses, up to six years, during the last century of activity of Piton de la Fournaise can be considered as a lull, despite the high frequency of eruption (1 eruption/9 months on average). Temporal and spatial variations in recurrence rate and eruptive dynamics of basaltic volcanism, such as those recognised at Piton de la Fournaise, should be considered in the formulation of hazard assessments and in the interpretation of precursory patterns
Multiparametric Analysis of Factors Associated With Eosinophilic Chronic Rhinosinusitis With Nasal Polyps.
Introduction: Previous studies have reported a diverse range of threshold values for blood eosinophilia. In addition, a single predictive biomarker for eosinophilic chronic rhinosinusitis (CRS) with nasal polyps (ECRSwNP) has not yet been identified. Objectives: The aim of this study is to compare the clinical characteristics of ECRSwNP and non-ECRSwNP to evaluate the preoperative risk of tissue eosinophilia of chronic rhinosinusitis with nasal polyps (CRSwNP) through a multiparametric statistical analysis. Methods: One hundred ten patients with evidence of chronic polypoid rhinosinusitis were included in this study and clinical records were retrospectively reviewed. Eosinophilic CRSwNP was diagnosed based on the presence of at least 10 eosinophils per high-power field. The demographic and clinical features of ECRSwNP and non-ECRSwNP are described. The values of blood eosinophilia as predictors of tissue eosinophilia have been identified using receiver operating characteristic curves. As the predictive value of the identified cutoff through regression analysis was low, we evaluated whether other risk factors could be statistically associated with ECRSwNP, and from this, a new predictive model was proposed for the identification of eosinophilic nasal polyps before surgery. Results: We found that the best method for predicting ECRSwNP is based on a model having asthma, blood eosinophil percentage, posterior ethmoid value in Lund-Mackay score, and modified Lund-Kennedy score as explanatory variables. Conclusions: This study provides new data for a better understanding of the polypoid CRS endotypes, and the proposed model allows the endotype to be identified preoperatively
Efficacy and use of benralizumab in patients with eosinophilic chronic rhinosinusitis
Abstract Chronic rhinosinusitis has a multifactorial etiology resulting from a dysfunctional interaction between various environmental factors and the host immune system. The patient of case report is affected by chronic rhinosinusitis with nasal polyps and a type 2 molecular pattern, has comorbid asthma and symptoms resistant to adequate medical and surgical therapy. The patient was treated with benralizumab, a mAb that binds IL-5Rα. The therapy resulted in a reduction in blood and tissue eosinophilia, but this was not associated with an improvement in the clinical and objective rhinological picture. Instead, at the lung level, there was a marked improvement in the control of severe asthma. Therefore, the patient was undergoing revision Full FESS in association with biological drug therapy. The patient showed an immediately improvement in the clinical and objective rhinological picture and this association allowed for control of the disease almost one year after surgery
Co-design of human-centered, explainable AI for clinical decision support
eXplainable AI (XAI) involves two intertwined but separate challenges: the development of techniques to extract explanations from black-box AI models, and the way such explanations are presented to users, i.e., the explanation user interface. Despite its importance, the second aspect has received limited attention so far in the literature. Effective AI explanation interfaces are fundamental for allowing human decision-makers to take advantage and oversee high-risk AI systems effectively. Following an iterative design approach, we present the first cycle of prototyping-testing-redesigning of an explainable AI technique, and its explanation user interface for clinical Decision Support Systems (DSS). We first present an XAI technique that meets the technical requirements of the healthcare domain: sequential, ontology-linked patient data, and multi-label classification tasks. We demonstrate its applicability to explain a clinical DSS, and we design a first prototype of an explanation user interface. Next, we test such a prototype with healthcare providers and collect their feedback, with a two-fold outcome: first, we obtain evidence that explanations increase usersâ trust in the XAI system, and second, we obtain useful insights on the perceived deficiencies of their interaction with the system, so that we can re-design a better, more human-centered explanation interface
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