1,035 research outputs found

    Outflows of very ionized gas in the center of Seyfert galaxies: kinematics and physical conditions

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    Mid-resolution spectra are used to deduce the size and kinematics of the coronal gas in a sample of Seyfert galaxies by means of observations of the [FeXI], [FeX], [FeVII], [SiVI] and [SiVII] lines. These coronal lines (CL) extend from the unresolved nucleus up to a few tens to a few hundreds of parsecs. The region of the highest ionized ions studied, [FeXI] and [FeX], is the least spatially extended, and concentrates at the center; intermediate ionization lines extend from the nucleus up to a few tens to a few hundred parsecs; lower [OIII]-like ions are known to extendin the kpc range. All together indicates a stratification in the ionized gas, usually interpreted in terms of nuclear photoionization as the driving ionization mechanism. However, CL profiles show various peculiarities: they are broader by a factor of two than lower ionization lines, the broadening being in terms of asymmetric blue wings, and their centroid position at the nucleus is blueshifted by a few hundreds of km/s. Moreover, in NGC1386 and NGC1068, a double peak [FeVII] line is detected in the nuclear and extended coronal region, this being the first report in of such type of profile in CL in active galactic nuclei. If interpreted as outflow signatures, the total broadening of the lines at zero intensity levels implies gas velocities up to 2000 km/s. Although the stratification of ions across the coronal region means that photoionization is the main power mechanism, the high velocities deduced from the profiles, the relatively large spatial extension of the emission, and the results from photoionization models indicate that an additional mechanism is at work. We suggest that shocks generated by the outflow could provide the additional required power for line formation.Comment: Accepted for publication in the Astrophysical Journal. 40 pages, 15 figures. Minor changes made on the affiliation of one co-autho

    The VMC survey - XIV. First results on the look-back time star formation rate tomography of the Small Magellanic Cloud

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    We analyse deep images from the VISTA survey of the Magellanic Clouds in the YJK(s) filters, covering 14 deg(2) (10 tiles), split into 120 subregions, and comprising the main body and Wing of the Small Magellanic Cloud (SMC). We apply a colour-magnitude diagram reconstruction method that returns their best-fitting star formation rate SFR(t), age-metallicity relation (AMR), distance and mean reddening, together with 68 per cent confidence intervals. The distance data can be approximated by a plane tilted in the East-West direction with a mean inclination of 39 degrees, although deviations of up to +/- 3 kpc suggest a distorted and warped disc. After assigning to every observed star a probability of belonging to a given age-metallicity interval, we build high-resolution population maps. These dramatically reveal the flocculent nature of the young star-forming regions and the nearly smooth features traced by older stellar generations. They document the formation of the SMC Wing at ages <0.2 Gyr and the peak of star formation in the SMC Bar at similar to 40 Myr. We clearly detect periods of enhanced star formation at 1.5 and 5 Gyr. The former is possibly related to a new feature found in the AMR, which suggests ingestion of metal-poor gas at ages slightly larger than 1 Gyr. The latter constitutes a major period of stellar mass formation. We confirm that the SFR(t) was moderately low at even older ages

    Influenza della sterilizzazione su strumenti fabbricati con leghe trattate termicamente

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    RiassuntoObiettiviDi recente sono stati proposti in endodonzia innovativi processi di produzione di leghe con trattamenti termici. Scopo di questo studio Ăš stato di valutare l'effetto di vari cicli di sterilizzazione in autoclave sulla resistenza alla fatica ciclica di strumenti endodontici rotanti realizzati con leghe nichel-titanio (Ni-Ti) trattate termicamente.Materiali e metodiSono stati selezionati tre gruppi (n=24) di strumenti in Ni-Ti di taglia 04.40 K3, in lega Ni-Ti tradizionale, Vortex, in lega M-Wire e K3 XT prototipi in lega TF. Ogni gruppo Ăš stato poi suddiviso in due sottogruppi (A e B) composti rispettivamente da strumenti non sterilizzati e strumenti sterilizzati in autoclave per 10 cicli a 134°. Tutti i 72 strumenti sono infine stati testati per fatica, valutando il numero di cicli a frattura (NCF). I dati sono stati raccolti e analizzati statisticamente (ANOVA).RisultatiGli strumenti K3 XT hanno mostrato una resistenza alla fatica ciclica significativamente maggiore (p<0,05) rispetto a tutti gli altri strumenti. Inoltre, sono state notate differenze statisticamente significative tra i file K3 XT sterilizzati e non sterilizzati (762 vs 651 NCF), mentre gli altri due tipi di strumento non hanno mostrato differenze rilevanti in seguito ai cicli di sterilizzazione (524 vs 539 K3, 454 vs 480 Vortex).ConclusioniPoichĂ© i K3 e i K3 XT sono identici nel disegno e si differenziano solo per il trattamento termico, si puĂČ ipotizzare un'influenza positiva dell'apporto termico, come quello derivante da sterilizzazione in autoclave, in alcune leghe trattate termicamente.SummaryObjectivesRecently, innovative processes of production of alloys with thermal treatment have been proposed in endodontics. The aim of this study was to evaluate the effect of various cycles of autoclave sterilization on cyclic fatigue resistance of rotary endodontic instruments, made of heat-treated nickel-titanium (Ni-Ti) alloys.Materials and methodsThree groups (n=24) of Ni-Ti instruments with the same size (04.40) were selected: K3 (traditional Ni-Ti alloy), Vortex (M-Wire alloy) and K3 XT prototype (TF alloy). Each group was then divided into two subgroups comprising respectively non-sterilized instruments and instruments sterilized in an autoclave for 10 cycles at 134°. All 72 instruments were finally tested for fatigue, considering the number of cycles to fracture (NCF). Data were collected and analyzed statistically (ANOVA).ResultsThe instruments K3 XT showed significantly higher resistance to cyclic fatigue than all other instruments. Statistically significant differences (p<0.05) were also noted among the files K3 XT sterilized and unsterilized (762 vs 651 NCF), while the other two types of instrument did not show significant differences as a result of sterilization cycles (524 vs 539 K3, 454 vs 480 Vortex).ConclusionsGiven that K3 and K3 XT are identical in design and differ only in the heat treatment, a positive influence of heat treatment, such as the one caused by autoclaving, can be hypothesized

    Ultrafast, Zero-Bias, Graphene Photodetectors with Polymeric Gate Dielectric on Passive Photonic Waveguides.

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    We report compact, scalable, high-performance, waveguide integrated graphene-based photodetectors (GPDs) for telecom and datacom applications, not affected by dark current. To exploit the photothermoelectric (PTE) effect, our devices rely on a graphene/polymer/graphene stack with static top split gates. The polymeric dielectric, poly(vinyl alcohol) (PVA), allows us to preserve graphene quality and to generate a controllable p-n junction. Both graphene layers are fabricated using aligned single-crystal graphene arrays grown by chemical vapor deposition. The use of PVA yields a low charge inhomogeneity ∌8 × 1010 cm-2 at the charge neutrality point, and a large Seebeck coefficient ∌140 ÎŒV K-1, enhancing the PTE effect. Our devices are the fastest GPDs operating with zero dark current, showing a flat frequency response up to 67 GHz without roll-off. This performance is achieved on a passive, low-cost, photonic platform, and does not rely on nanoscale plasmonic structures. This, combined with scalability and ease of integration, makes our GPDs a promising building block for next-generation optical communication devices

    Comparison of hormonal receptor and HER-2 status between breast primary tumours and relapsing tumours: clinical implications of progesterone receptor loss

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    Differences in hormone receptor and HER-2 status between primary tumour and corresponding relapse could have a substantial impact on clinical management of patients. The aim of this study was to evaluate change in expression of hormone receptors and HER-2 status between primary tumour and corresponding local recurrence or distant metastasis. We analysed 140 primary tumours and related recurrent or metastatic samples. Hormone receptors status was evaluated by immunohistochemistry, while HER-2 status by immunohistochemistry and silver in situ hybridisation. A change in HER-2 was rare; 3.7% of cases by immunohistochemistry and only 0.7% by silver in situ hybridisation analysis. A change in estrogen and progesterone receptors was seen in 6.4% and 21.4% of cases, respectively. Estrogen receptor change was not affected by adjuvant therapy, whereas progesterone receptor was influenced by adjuvant chemotherapy associated to hormone therapy (P = 0.0005). A change in progesterone receptor was more frequent in distant metastases than in local recurrences (P = 0.03). In the setting of estrogen receptor positive tumours, patients with progesterone receptor loss in local recurrence had a statistically significant lower median metastasis free survival compared to others patients; progesterone receptor positive, 112 months; progesterone receptor negative, 24 months (P = 0.005). A change between primary tumour and corresponding relapse is frequent for progesterone receptor, infrequent for estrogen receptor and rare for HER-2. In cases with changes in HER-2, it is worthwhile reassessing HER-2 status with both immunohistochemistry and in situ hybridisation analysis. Progesterone receptor loss seems to be influenced by therapy and to correlate with a worse prognosis

    A conservation roadmap for the subterranean biome

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    The 15th UN Convention on Biological Diversity (CBD) (COP15) will be held in Kunming, China in October 2021. Historically, CBDs and other multilateral treaties have either alluded to or entirely overlooked the subterranean biome. A multilateral effort to robustly examine, monitor, and incorporate the subterranean biome into future conservation targets will enable the CBD to further improve the ecological effectiveness of protected areas by including groundwater resources, subterranean ecosystem services, and the profoundly endemic subsurface biodiversity. To this end, we proffer a conservation roadmap that embodies five conceptual areas: (1) science gaps and data management needs; (2) anthropogenic stressors; (3) socioeconomic analysis and conflict resolution; (4) environmental education; and (5) national policies and multilateral agreements.Peer reviewe

    Massive black hole science with eLISA

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    The evolving Laser Interferometer Space Antenna (eLISA) will revolutionize our understanding of the formation and evolution of massive black holes (MBHs) along cosmic history, by probing massive black hole binaries (MBHBs) in the 10(3) - 10(7) M-circle dot range out to redshift z greater than or similar to 10. High signal-to-noise ratio detections of similar to 10 - 100 MBHB coalescences per year will allow accurate measurements of the parameters of individual MBHBs (such as their masses, spins and luminosity distance), and a deep understanding of the underlying cosmic MBH parent population. This wealth of unprecedented information can lead to breakthroughs in many areas of physics, including astrophysics, cosmology and fundamental physics. We review the current status of the field, recent progress and future challenges

    Disease-specific and general health-related quality of life in newly diagnosed prostate cancer patients: The Pros-IT CNR study

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    Background: The National Research Council (CNR) prostate cancer monitoring project in Italy (Pros-IT CNR) is an observational, prospective, ongoing, multicentre study aiming to monitor a sample of Italian males diagnosed as new cases of prostate cancer. The present study aims to present data on the quality of life at time prostate cancer is diagnosed. Methods: One thousand seven hundred five patients were enrolled. Quality of life is evaluated at the time cancer was diagnosed and at subsequent assessments via the Italian version of the University of California Los Angeles-Prostate Cancer Index (UCLA-PCI) and the Short Form Health Survey (SF-12). Results: At diagnosis, lower scores on the physical component of the SF-12 were associated to older ages, obesity and the presence of 3+ moderate/severe comorbidities. Lower scores on the mental component were associated to younger ages, the presence of 3+ moderate/severe comorbidities and a T-score higher than one. Urinary and bowel functions according to UCLA-PCI were generally good. Almost 5% of the sample reported using at least one safety pad daily to control urinary loss; less than 3% reported moderate/severe problems attributable to bowel functions, and sexual function was a moderate/severe problem for 26.7%. Diabetes, 3+ moderate/severe comorbidities, T2 or T3-T4 categories and a Gleason score of eight or more were significantly associated with lower sexual function scores at diagnosis. Conclusions: Data collected by the Pros-IT CNR study have clarified the baseline status of newly diagnosed prostate cancer patients. A comprehensive assessment of quality of life will allow to objectively evaluate outcomes of different profile of care

    Observation of (tt)over-barH Production

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    The observation of Higgs boson production in association with a top quark-antiquark pair is reported, based on a combined analysis of proton-proton collision data at center-of-mass energies of root s = 7, 8, and 13 TeV, corresponding to integrated luminosities of up to 5.1, 19.7, and 35.9 fb(-1), respectively. The data were collected with the CMS detector at the CERN LHC. The results of statistically independent searches for Higgs bosons produced in conjunction with a top quark-antiquark pair and decaying to pairs of W bosons, Z bosons, photons, tau leptons, or bottom quark jets are combined to maximize sensitivity. An excess of events is observed, with a significance of 5.2 standard deviations, over the expectation from the background-only hypothesis. The corresponding expected significance from the standard model for a Higgs boson mass of 125.09 GeV is 4.2 standard deviations. The combined best fit signal strength normalized to the standard model prediction is 1.26(-0.26)(+0.31).Peer reviewe

    Study of Z boson production in pPb collisions at √sNN=5.02 TeV

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    The production of Z bosons in pPb collisions at root S-NN = 5.02 TeV is studied by the CMS experiment via the electron and muon decay channels. The inclusive cross section is compared to pp collision predictions, and found to scale with the number of elementary nucleon-nucleon collisions. The differential cross sections as a function of the Z boson rapidity and transverse momentum are measured. Though they are found to be consistent within uncertainty with theoretical predictions both with and without nuclear effects, the forward-backward asymmetry suggests the presence of nuclear effects at large rapidities. These results provide new data for constraining nuclear parton distribution functions
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