169,826 research outputs found
Deep spectroscopic luminosity function of Abell 85 : no evidence for a steep upturn of the faint-end slope
Full text linkIA, AD and ALS acknowledge partial support from the INFN grant InDark and from the grant Progetti di Ateneo TO Call 2012 0011 ‘Marco Polo’ of the University of Torino.We present a new deep determination of the spectroscopic luminosity function (LF) within the virial radius of the nearby and massive Abell 85 (A85) cluster down to the dwarf regime (M* + 6) using Very Large Telescope/Visible Multi-Object Spectrograph (VLT/VIMOS) spectra for ∼2000 galaxies with mr ≤ 21 mag and 〈μe,r〉 ≤ 24 mag arcsec−2. The resulting LF from 438 cluster members is best modelled by a double Schechter function due to the presence of a statistically significant upturn at the faint end. The amplitude of this upturn (αf ~ -1.58+0.19-0.15), however, is much smaller than that of the Sloan Digital Sky Survey (SDSS) composite photometric cluster LF by Popesso et al., αf ∼ −2. The faint-end slope of the LF in A85 is consistent, within the uncertainties, with that of the field. The red galaxy population dominates the LF at low luminosities, and is the main factor responsible for the upturn. The fact that the slopes of the spectroscopic LFs in the field and in a cluster as massive as A85 are similar suggests that the cluster environment does not play a major role in determining the abundance of low-mass galaxies.Peer reviewe
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Coastal flooding risk scenario for the city of Grado, northern Adriatic Sea
No full textSea level rise, along with fast urbanization, has significantly raised flood hazards in coastal areas due to both increased population and the frequent urgent situations encountered in the urban context (Neumann, 2015). Rigid defensive systems along shorelines, backshore, and perimeter embankments at the lagoon border must therefore undergo structural verification and accurate elevation control, adapted to the expected sea level rise over which extreme events emerge. In this regard, a thorough investigation was conducted on the city of Grado, located in the North Adriatic Sea and representing one of the most important coastline and heritage sites in Friuli Venezia Giulia. The city is located on a barrier island and is prone to flooding from both the sea and from the back lagoon. The examination of the historical dataset of mean sea level and maximum levels recorded between 1991 and 2022 allowed us to first obtain local elevation estimates while also including subsidence. The study then looked at the duration of annual exceedance of the minimal threshold level of 110 cm, which marks Grado’s first significant marine ingression. Annual extremes were then processed using the Gumbel-type distribution law (Gumbel, 1958; Coles, 2001), which modulated the level thresholds with their respective return times for the location. Finally, the reconnaissance includes a downscaling examination of the impacts on the urban fabric, which is divided into regions of different vulnerability. Inundated areas were compared from high resolution DEMs using a GIS-based technique and a modeling approach utilizing MIKE software, analyzing both the magnitude and exposure of the urban setting to flood risk estimated for 2050 and 2100. As of today, approximately 56% of Grado’s inhabited area is inundated with a sea level threshold value of 151 cm, which occurs during surge episodes with a 30-year return period. By 2100, with an optimistic forecast (SSP1-2.6) of local sea level rise of around +50 cm, the same threshold will be met with events with a 30 times shorter return time. As a result, by 2100, 56% of the land area will be submerged at least once a year due to 101 cm surges. Extreme levels linked with more catastrophic events with secular recurrence times will be achieved on a multiyear basis, flooding more than 70% of the urbanized area. This makes it more important than ever to develop proper adaptation measures from the outset. The simulations developed are thus essential for medium to longterm urban planning, with the goal of securing the city, which, like Venice, is indicative of the processes that may affect other coastal realities and historical cities of great national worth
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
The great observatories origins deep survey - VLT/VIMOS spectroscopy in the GOODS-south field: Part II
No full textContext. We present the full data set of the VIsible Multi-Object Spectrograph (VIMOS)
spectroscopic campaign of the ESO/GOODS program in the Chandra Deep Field South (CDFS),
which complements the FORS2 ESO/GOODS spectroscopic campaign.
Aims. The ESO/GOODS spectroscopic programs are aimed at reaching
signal-to-noise ratios adequate to measure redshifts for galaxies with
AB magnitudes in the range ~24-25 in the B and R band using VIMOS,
and in the z band using FORS2.
Methods. The GOODS/VIMOS spectroscopic campaign is structured in two separate surveys using two
different VIMOS grisms. The VIMOS Low Resolution Blue (LR-Blue) and Medium Resolution
(MR) orange grisms have been used to cover
different redshift ranges. The LR-Blue campaign is aimed at observing
galaxies mainly at 1.8 < z < 3.5, while the MR campaign mainly aims at galaxies at z < 1
and Lyman Break Galaxies (LBGs) at z > 3.5.
Results. The full GOODS/VIMOS spectroscopic campaign consists of 20 VIMOS masks.
This release adds 8 new masks to the previous release (12 masks, Popesso et al. 2009, A&A, 494, 443).
In total we obtained 5052 spectra, 3634 from the 10 LR-Blue masks and
1418 from the 10 MR masks. A significant fraction of the extracted spectra
comes from serendipitously observed sources: ~21% in the LR-Blue and
~16% in the MR masks. We obtained 2242 redshifts in the LR-Blue campaign
and 976 in the MR campaign for a total success rate of 62% and 69%
respectively, which increases to 66% and 73% if only primary targets
are considered. The typical redshift uncertainty is estimated to be
0.00084 (~255 km s-1) for the LR-Blue grism
and 0.00040 (~120 km s-1) for
the MR grism. By complementing our VIMOS spectroscopic catalog with all existing
spectroscopic redshifts publicly available in the CDFS, we compiled a redshift
master catalog with 7332 entries, which we used
to investigate large scale structures out to z 3.7. We produced stacked spectra
of LBGs in a few bins of equivalent width (EW) of the Ly-α and found evidence for
a lack of bright LBGs with high EW of the Ly-α.
Finally, we obtained new redshifts for 12 X-ray sources of the CDFS and extended-CDFS.
Conclusions. After the completion of the two complementary ESO/GOODS spectroscopic campaigns
with VIMOS and FORS2 at VLT, the number of spectroscopic redshifts in
CDFS/GOODS field increased dramatically, in particular at z \ga 2. These data
provide the redshift information indispensable to achieve the scientific goals
of GOODS, such as tracing the evolution of galaxy masses, morphologies, clustering,
and star formation
A Multi-Language Comparison of Influences on Author Verification using Character N-Grams
No full textWe create a new multi-language corpus for author verification based on Wikipedia talkpages, and evaluate the influence that differences in topic and time have on character n-gram author profiles. Topic alignment between two texts is found to increase author verification precision, and an authors writing style is found to change over time, but not more significantly after 3 years than after 1 year.Information ArchitectureWISElectrical Engineering, Mathematics and Computer Scienc
A 0.12mm<sup>2</sup> Wien-Bridge Temperature Sensor with 0.1°C (3σ) Inaccuracy from -40°C to 180°C
No full text Resistor-based temperature sensors can achieve much higher resolution and energy efficiency than conventional BJT-based sensors [1], but they typically occupy more area (> 0.25 mm 2 ) and have lower operating temperatures (le 125 {circ} {C}) [2]-[4]. This work describes a 0.12mm 2 resistor-based sensor that uses a Wien-bridge (WB) filter to achieve 0.1 {circ} {C} (3 sigma) inaccuracy from - 40 {circ} {C} to 180 {circ} {C}. Compared to a state-of-the-art WB sensor [4], it occupies 6 × less area and achieves comparable relative accuracy over a 76% wider operating range. Session 10.3 Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
A ±25A Versatile Shunt-Based Current Sensor with 10kHz Bandwidth and ±0.25% Gain Error from -40°C to 85°C Using 2-Current Calibration
No full textAccurate current sensing is critical in many industrial applications, such as battery management and motor control. Precise shunt-based current sensors have been reported with gain errors of less than 1% over the industrial temperature range (-40°C to 85°C) [1]–[4]. However, since they are intended for coulomb counting, their bandwidth is limited to a few tens of Hz, making them unsuitable for battery impedance or motor-current sensing. This paper presents a current sensor with a wide (10kHz) bandwidth and a tunable temperature compensation scheme (TCS), which allows it to be flexibly used with different types of shunts while maintaining high accuracy. A low-cost room-temperature calibration scheme is proposed to optimize gain flatness over temperature by exploiting the shunt's self-heating at large currents. Over the industrial temperature range and a ±25A current range, it achieves state-of-the-art gain error (±0.25%) with both low-cost PCB and stable metal-alloy shunts.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Electronic InstrumentationMicroelectronic
COASTAL VULNERABILITY ASSESSMENT OF VENETO BEACHES AND BARRIER ISLANDS, NORTHERN ADRIATIC, ITALY
No full textThe assessment of coastal vulnerability to sea storms is critical in coastal management since sea level rise and human pressure affect both the morphological and sedimentary constraints, thus increasing coastal risks. In this work we present an assessment of sea storm vulnerability for the 170 km of coastline of the Veneto area (Northern Adriatic, Italy), using an adaptation of the Coastal Vulnerability Index. The methodology relies on a comprehensive coastal geodatabase and includes the estimate of the Intrinsic Vulnerability (Vi): several variables were analysed and weighted to define the physical and evolutionary conditions of the coast, under the assumption that there is no defence against sea storms. Subsequently, the classification and evaluation of coastal defences (hard and soft) allows the shift from intrinsic to Real vulnerability (Vr). Owing to a methodological adjustment made for the various coastal types (barrier islands or beaches), the results show varying grades of Vi depending on distinct morpho evolutive conditions. Low values of Vi are typical of coastal tracts acting as sedimentary traps in proximity to jettied or unjettied tidal inlets. At the same time, along the Po delta, some barrier islands have dissipative characteristics and positive sedimentary budget due to the sandy load from river branches. In many cases, beaches with moderate Vi benefit from the widespread distribution of hard coastal defences and the presence of coastal dunes, which mitigate vulnerability. Finally, littoral sections with high Vi are mostly afflicted by a persistent sedimentary deficit, resulting in absent or narrow beaches with steep shoreface. Overall, the massive use of hard defence works ensures safety, although impeding any resilience of the morpho sedimentary system
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