170,408 research outputs found
'We always come here': investigating the social in social learning
No full textThis paper investigates student choices around the 'Third Space' for learning; that which is not either a teaching space or a private space. In mapping the use of such spaces around the University of Northampton's campuses and through the use of semi-structured interviews with students as they use the spaces it constructs a model to help understand why students choose a particular space to work in and influence decisions in the deliberate creation of such spaces in future.
The research shows four, often overlapping, influences on student choice of space; resources, environment, social and emotional. That resource rich spaces that allow social interaction and learning to take place in attractive environments are popular should not be surprising but it is the emotional response to space that is of particular interest. Space attachment theory has usually centred on home or places with religious or national symbolism. This paper identifies an element of emotional resonance to areas of the university campus, especially the library, that will warrant further research
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
Exosome release by crustacean hyaline haemocytes in vitro
No full textExosomes are small microvesicles (40–100 nm) that are formed from the endosome to
generate multi-vesicular bodies (MBVs). In mammals, exosomes play a significant role in
cellular communication. Exosomes have also been reported for salmon and fruit fly but
have not previously been studied in crustaceans. Therefore we undertook to study them
in decapods. We chose the hyaline haemocytes of brachyuran crabs, Carcinus maenas and Hyas araneus, because these cells are abundant in haemolymph, are phagocytic and can be
cultured on glass or plastic surfaces. Furthermore these cells have been observed to
contain MVB-like structures that bear some resemblance to those in mammals that
produce exosomes. Preliminary results show that highly enriched hyaline cells of both C.
maenas and H. araneus, express actin and haemocyanin during 24 h in vitro. The presence of
haemocyanin subunits is interesting because haemocyanin is a multifunctional protein
that participates in immunity in crustaceans. As far as we are aware, the present study is
the first to show that hyaline cells from a crustacean secrete this biologically important
protein. Other proteins were found but we were unable to identify them by mass
spectroscopy. Treatment of the hyaline cells in vitro with LPS at sub-lethal concentrations
failed to reveal a change in the flow cytometric scatter plots or in the protein profiles on
SDS-PAGE
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
The role of HLA-B27 in inflammatory arthritis
No full textRedacted electronic version excludes material for which permission has not been granted by the rights holderThe MHC class I allele, HLA-B27, is strongly associated with a group of inflammatory arthritic conditions collectively known as spondyloarthropathies (SpA). Ankylosing spondylitis (AS) shows the strongest association with 90-95 % of patients being HLA-B27 positive. The relationship between HLA-B27 and SpA has been known for over 30 years, however despite ongoing research, the reason for this association has not yet been elucidated. In more recent years, research has focused on intrinsic properties of the HLA-B27 allele, in particular its propensity to misfold, forming homodimers. It has been proposed that these homodimers could be associated with the disease process through the activation of an ER stress response known as the unfolded protein response (UPR), or through aberrant recognition at the cell surface.
We have investigated whether the expression of HLA-B27 is associated with the activation of the UPR. We have studied the expression of BiP, and the cleavage of XBP1 and ATF6 using stable and transiently expressing cell lines. We have also investigated the formation of non-B27 homodimers using a human cell line stably expressing HLA-B8, and finally we have studied the expression of homodimers in exosomes, small immunomodulatory vesicles released from numerous cell types. The results presented here lead us to conclude that in vitro studies of the UPR are complicated, prone to a number of technical issues, and may therefore not be appropriate for gaining information that would be of significant use when comparing to the real disease scenario. Our data suggest that non-B27 dimers may be strongly influenced by both the overexpression of MHC class I heavy chains and also the redox environment within the cell.
We have isolated a novel fully folded, beta-2m-associated, MHC class I homodimer in exosomes and have detected a novel HLA-A and HLA-B mixed heavy chain dimer. Our results suggest that these dimers form through interactions between the cysteine residues in the cytoplasmic tail and that these dimers form in exosomes because they contain lower levels of the important antioxidant glutathione when compared to whole cells. Together, these results define a new MHC class I structure present on exosomes at significant levels, which could potentially influence immune recognition by both antigen-specific T cell receptors and NK family receptors. The data also poses questions about whether these novel structures, when they involve HLA-B27, could influence the pathogenesis of spondyloarthropathies
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