170,085 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
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
No full textWe 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
Diversity of colletotrichum species associated with olive anthracnose worldwide
No full textOlive anthracnose caused by Colletotrichum species causes dramatic losses of fruit yield and oil quality worldwide. A total of 185 Colletotrichum isolates obtained from olives and other hosts showing anthracnose symptoms in Spain and other olive-growing countries over the world were characterized. Colony and conidial morphology, benomyl-sensitive, and casein-hydrolysis activity were recorded. Multilocus alignments of ITS, TUB2, ACT, CHS-1, HIS3, and/or GAPDH were conducted for their molecular identification. The pathogenicity of the most representative Colletotrichum species was tested to olive fruits and to other hosts, such as almonds, apples, oleander, sweet oranges, and strawberries. In general, the phenotypic characters recorded were not useful to identify all species, although they allowed the separation of some species or species complexes. ITS and TUB2 were enough to infer Colletotrichum species within C. acutatum and C. boninense complexes, whereas ITS, TUB2, ACT, CHS-1, HIS-3, and GADPH regions were necessary to discriminate within the C. gloesporioides complex. Twelve Colletotrichum species belonging to C. acutatum, C. boninense, and C. gloeosporioides complexes were identified, with C. godetiae being dominant in Spain, Italy, Greece, and Tunisia, C. nymphaeae in Portugal, and C. fioriniae in California. The highest diversity with eight Colletotrichum spp. was found in Australia. Significant differences in virulence to olives were observed between isolates depending on the Colletotrichum species and host origin. When other hosts were inoculated, most of the Colletotrichum isolates tested were pathogenic in all the hosts evaluated, except for C. siamense to apple and sweet orange fruits, and C. godetiae to oleander leaves
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
A User-Centric Service Creation Approach for Next Generation Networks
No full textThe architecture and technologies for the Next Generation Networks are well known. The service provision approach is not so clear though. While the Telecommunications killer application still remains to be found, new competitors in the new all-IP world threaten the traditional business models of telcos by providing their services directly to the operators' customers. An innovative paradigm has recently come about in the Internet which allows users to create and share their own services from the composition of other services. User-centric service creation environments improve the service offering with profitable, value-added services faster and cheaper than ever before. This paper presents the initial results of a research project that applies the user-centric approach to the creative combination of Web and network services over Next Generation Networks
The race between retrotransposons and tandem repeats for shaping genome structure. The case of Olea.
No full textGenome size evolution is a process mainly determined by processes as polyploidization and
amplification/loss of transposons, with a minor role played by other repeated sequences such as
tandem repeats.
In the cultivated olive, available data suggest a singular model of genome evolution, in which
a massive expansion of tandem repeated sequences accompanied changes in nuclear architecture.
Focusing on Olea genus evolution, NGS technologies, bioinformatics and in situ hybridization were
applied to study the genome structure of 5 related Olea taxa originated at different times from the
last common ancestor.
On average, repetitive DNA in Olea taxa ranged from ~59% to ~73%, showing remarkable
differences in terms of composition and abundance. We identified 11 major families of tandem
repeats, 5 of which for the first time. Overall, tandem repeat abundance was inversely correlated to
that of retrotransposons, with the exception of O. paniculata which has very few tandem-repeated
sequences being, on the contrary, especially rich in long terminal repeat-retrotransposons,
suggesting that the amplification of tandem repeats occurred after its divergence from the Olea
common ancestor. Furthermore, cytological analyses underlined differences in genome size and
chromatin organization of O. paniculata, whose genome is about 50% larger of that of cultivated
olive compared to O. europaea subsp. europaea. Our results, supported by retrotransposon timing
data and by in situ hybridization, indicates that the genome expansion of O. paniculata may be
derived from massive amplification of major individual retrotransposon families in the last 20 MY.
Our research identified the temporal dynamics shaping Olea genome structure, which
represent a very peculiar model of evolution in higher plants characterized by a preminent role of
tandem repeats in fostering genome structure variation, also suggesting a possible role of
transposons in tandem repeats evolution and mobility
Not only transposons: the peculiar evolution of olive genome structure.
No full textThe current view of plant genome evolution proposes that genome size is determined by
processes such as polyploidization and amplification and/or loss of transposable elements. Other
types of repeated sequences, including tandem repeats, usually have a minor role in shaping plant
genome structure and size, accounting for a small portion of the genomes sequenced so far.
In the cultivated olive (Olea europaea L. subsp. europaea var. europaea), available data
suggest the occurrence of a singular model of genome evolution, in which polyploidization and
amplification/loss of transposons were accompanied by a massive expansion of the tandem repeated
fraction. This fraction is composed by six major families of satellites, that make almost one third of
the genome. This peculiarity highlights the necessity of further studies about the evolution of the
Olea genus, to shed light on mechanisms of genome expansion and the possible function of the
different types of repeated sequences.
Massively parallel sequencing technologies, advanced bioinformatic analyses and in situ
hybridization, were applied to study in detail the genome structure of cultivated olive and other 4
related species or subspecies (O. europaea subsp. cuspidata, O. europaea subsp. guanchica, O.
exasperata, and O. paniculata). They originated at different times from the common ancestor from
which the cultivated form derived.
Our analysis led to a complete characterization of the repeated fraction of the genomes of the
selected Olea species, with emphasis on the tandem repeats. On average, repetitive DNA in Olea
species ranges from 42% in O. paniculata to 66% in O. europaea subsp. cuspidata, showing
remarkable differences in terms of composition. In fact, the 11 major families of tandem repeats
identified across the analyzed species presented different redundancy levels. Thus, some families
were barely represented in one species and highly redundant in another. A large number of longterminal-repeat (LTR) retrotransposons (of different lineages) were also found in every Olea
species. Interestingly, overall tandem repeat redundancy was inversely correlated to that of
retrotransposons. This trend might implicate a competition in the proliferation of these two classes
of repeats. As a matter of fact, O. paniculata, the closer species to the Olea common ancestor,
presents very few tandemly-repeated sequences (as most plant species) while it is rich in LTRretrotransposons, suggesting that the amplification of tandem repeats occurred after its speciation
from the common ancestor of the other four species (which include the cultivated olive tree).
In conclusion, our research identified the temporal dynamics shaping the genome structure
during the evolution of the genus Olea. This genus represents a very peculiar model of genome
evolution in higher plants. Studies are in progress to estimate the intraspecifc variation of the repeat
component, in order to decipher the possible role that tandem repeats played during the evolution of
the olive genome
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