170,129 research outputs found
Intercage dynamics of C-60 in doped crystals
No full textThe low-frequency regions of the Inelastic Neutron Scattering spectra of K3C60, Rb3C60, and Rb6C60 are modelled by atomistic Molecular Dynamics simulations followed by Fourier Transform. The use of a standard force field for the interatomic interactions, together with the simple hypothesis that the charges are homogeneously distributed over the cage, obtains a reasonable agreement with the experiments for the spectra of K3C60 and Rb6C60, but systematically underestimates the location of some bands, especially for Rb3C60. Analysis of the results suggests that the inaccuracy is caused by the atom-atom van der Waals interactions
A Woodward-Hoffmann approach to the C-60 cluster opening leading to homo[6]1fullerenes
No full textThe electrocyclic valence isomerization interconverting bismethano[60]fullerenes 1 and 2 with 1,2,3,6-(type I) and 1,2,3,4-addition patterns (type II) into the corresponding cluster-opened bismethanohomo[60]fullerenes was investigated computationally with respect to the energy profile and to the retention of molecular orbital symmetry. Whereas for 1 the closed form is unstable and spontaneously isomerizes to the cluster-open adduct, the energy difference between the open and closed isomers of 2 is comparatively small. The B3LYP/6-31G* energy of open 2 is only 1.2 kcal mol(-1) higher than that of the closed form. Analysis of the frontier orbital symmetries of 1, 2, and the [5,6]-bridged methano-homo[60]fullerene 3 showed that during these electrocylic valence isomerizations the orbital symmetry is retained and, as a consequence, a Woodward-Hoffmann-type selection principle is valid
Coptotermes kalshoveni Kemner Larger 1934
No full text<i>Coptotermes kalshoveni</i> Kemner, 1934 <p>(Figures 5A–E, 13C)</p> <p> <i>Coptotermes kalshoveni</i> Kemner, 1934: 61.</p> <p> <i>Material examined</i></p> <p> THAILAND: <b>Trang</b>: Ka Chong, 3 March 1962, M. Ahmad coll. [NHML]; <b>Narathiwat</b>: two series, Hara Bara Wildlife Sanctuary, 300 m alt., 29 May 1997, Y. Takematsu coll.; Phu To Daeng, 31 May 1997, Y. Takematsu coll.</p> <p> <i>Diagnosis</i></p> <p> <i>Soldier.</i> Head and pronotum sparsely hairy; postmentum with several long hairs. Head subcircular, considerably narrowed anteriorly, bHW <i>/</i> mHW 0.50–0.55 (0.52); mandibles weakly incurved, LML <i>/</i> HL 0.57–0.63 (0.59). Antennae with 13–14 segments. Narrowest part of postmentum located about one-third of the distance from the posterior margin to the widest point.</p> <p> <i>Measurements (mm)</i></p> <p>Eleven soldiers from three series: HL, 1.04–1.20 (1.10); mHW, 0.94–1.01 (0.97); LML, 0.61–0.74 (0.65); PL, 0.35–0.40 (0.37); PW, 0.60–0.73 (0.65); PosL, 0.61–0.70 (0.65); PosW, 0.29–0.34 (0.31).</p> <p> <i>Distribution</i></p> <p>Thailand (South), Peninsular Malaysia, Sumatra, Borneo, Java.</p> <p> <i>Remarks</i></p> <p> This species has only been recorded south of the Kra Isthmus (Figure 13C). This small species can be distinguished from the smaller individuals of <i>C. gestroi</i> by having a more rounded head that is strongly narrowed anteriorly, and the postmentum narrowest near the posterior end.</p>Published as part of <i>Takematsu, Yoko & Vongkaluang, Charunee, 2012, A taxonomic review of the Rhinotermitidae (Isoptera) of Thailand, pp. 1079-1109 in Journal of Natural History 46 (17 - 18)</i> on pages 1088-1089, DOI: 10.1080/00222933.2011.651653, <a href="http://zenodo.org/record/5199813">http://zenodo.org/record/5199813</a>
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
The Interplay between Gaze Following, Emotion Recognition, and Empathy across Adolescence; a Pubertal Dip in Performance?
No full textDuring puberty a dip in face recognition is often observed, possibly caused by heightened levels of gonadal hormones which in turn affects the re-organization of relevant cortical circuitry. In the current study we investigated whether a pubertal dip could be observed in three other abilities related to social information processing: gaze following, emotion recognition from the eyes, and empathizing abilities. Across these abilities we further explored whether these measurements revealed sex differences as another way to understand how gonadal hormones affect processing of social information. Results show that across adolescence, there are improvements in emotion recognition from the eyes and in empathizing abilities. These improvements did not show a dip, but are more plateau-like. The gaze cueing effect did not change over adolescence. We only observed sex differences in empathizing abilities, with girls showing higher scores than boys. Based on these results it appears that gonadal hormones are not exerting a unified influence on higher levels of social information processing. Further research should also explore changes in (visual) information processing around puberty onset to find a more fitted explanation for changes in social behavior across adolescence
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
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