170,120 research outputs found
[16] Thiamine transport in Escherichia coli crookes
No full textThis chapter describes the measurement technique of thiamine transport in Escherichia coli crookes. E. coli Crookes ATCC 8739 are grown in M-9 minimal medium supplemented with 0.2% glucose on a New Brunswick R-10 reciprocating shaker at 37 ° C. Appropriate samples of the cell suspension, in log growth unless otherwise specified, are filtered onto Gelman Metrical GA-6 filters and washed with 5 ml of 50 mM Tris, pH 8.0. Little uptake of thiamine occurs at 4% and both the initial rate and the capacity (amount taken up when uptake no longer increases with additional incubation) are approximately doubled by increasing the temperature from 25 ° C to 37 ° C. Glucose is the most effective energy source; the relative rates of uptake with 10 mM glucose, 20 mM DL-lactate, and 10 mM pyruvate are 1:0.78:0.58, respectively. The chapter describes the effects of proteolytic enzymes on thiamine transport
Perceptual Oscillations in Gender Classification of Faces, Contingent on Stimulus History
No full textPerception is a proactive ‘‘predictive’’ process, in which the brain takes advantage of past experience to make informed guesses about the world to test against sensory data. Here we demonstrate that in the judgment of the gender of faces, beta rhythms play an important role in communicating perceptual experience. Observers classified in forced choice as male or female, a sequence of face stimuli, which were physically constructed to be male or female or androgynous (equal morph). Classification of the androgynous stimuli oscillated rhythmically between male and female, following a complex waveform comprising 13.5 and 17 Hz. Parsing the trials based on the preceding stimulus showed that responses to androgynous stimuli preceded by male stimuli oscillated reliably at 17 Hz, whereas those preceded by female stimuli oscillated at 13.5 Hz. These results suggest that perceptual priors for face perception from recent perceptual memory are communicated through frequency-coded beta rhythms
The potential of di-methyl ether (DME) as an alternative fuel for compression-ignition engines: A review
No full textThis paper reviews the properties and application of di-methyl ether (DME) as a candidate fuel for compression-ignition engines. DME is produced by the conversion of various feedstock such as natural gas, coal, oil residues and bio-mass. To determine the technical feasibility of DME, the review compares its key properties with those of diesel fuel that are relevant to this application. DME’s diesel engine-compatible properties are its high cetane number and low auto-ignition temperature. In addition, its simple chemical structure and high oxygen content result in soot-free combustion in engines. Fuel injection of DME can be achieved through both conventional mechanical and current common-rail systems but requires slight modification of the standard system to prevent corrosion and overcome low lubricity. The spray characteristics of DME enable its application to compression-ignition engines despite some differences in its properties such as easier evaporation and lower density. Overall, the low particulate matter production of DME provides adequate justification for its consideration as a candidate fuel in compression-ignition engines. Recent research and development shows comparable output performance to a diesel fuel led engine but with lower particulate emissions. NOx emissions from DME-fuelled engines can meet future regulations with high exhaust gas recirculation in combination with a lean NOx trap. Although more development work has focused on medium or heavy-duty engines, this paper provides a comprehensive review of the technical feasibility of DME as a candidate fuel for environmentally-friendly compression-ignition engines independent of size or application
FIGURE 10 in New Oppiidae (Acari: Oribatida) from Vernon Crookes Nature Reserve, South Africa
No full textFIGURE 10. Brachioppiella (Gressittoppia) ricknuttalli sp. nov. (legs removed) A. Dorsal view; B. ventral view; C. lateral view (ventral setae not shown).Published as part of Hugo-Coetzee, Elizabeth A., 2017, New Oppiidae (Acari: Oribatida) from Vernon Crookes Nature Reserve, South Africa, pp. 211-232 in Zootaxa 4311 (2) on page 228, DOI: 10.11646/zootaxa.4311.2.3, http://zenodo.org/record/84749
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
FIGURE 6. Setoppia karinae Mahunka, 1974 in New Oppiidae (Acari: Oribatida) from Vernon Crookes Nature Reserve, South Africa
No full textFIGURE 6. Setoppia karinae Mahunka, 1974 (legs removed) A. Dorsal view; B. ventral view; C. lateral view (seta 3a not shown).Published as part of Hugo-Coetzee, Elizabeth A., 2017, New Oppiidae (Acari: Oribatida) from Vernon Crookes Nature Reserve, South Africa, pp. 211-232 in Zootaxa 4311 (2) on page 221, DOI: 10.11646/zootaxa.4311.2.3, http://zenodo.org/record/84749
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
sj-docx-1-mpp-10.1177_23814683231163189 – Supplemental material for Involvement in Chemotherapy Decision Making among Patients with Stage II and III Colon Cancer
No full textSupplemental material, sj-docx-1-mpp-10.1177_23814683231163189 for Involvement in Chemotherapy Decision Making among Patients with Stage II and III Colon Cancer by Jessica D. Austin, Elizabeth Shelton, Danielle M. Crookes, Alfred I. Neugut and Rachel C. Shelton in MDM Policy & Practice</p
The dynamic mechanism of a moving Crookes radiometer
No full textThe dynamics of a 2D rotating Crookes radiometer is studied using a moving mesh unified gas kinetic scheme. The whole evolution process of a fan from an initial unsteady start-up to a final steady state rotational movement in a rarefied gas environment is simulated numerically. Through the numerical study, the unsteady force distribution along a vane which dynamically drives the fan movement is captured. And a quantitative connection between total torque and rotational speed of the fan in the Knudsen number regime of 10(-3) < Kn < 10(2) is obtained. Based on the dimensional analysis, the total radiometric torque can be decomposed into a net radiometric driving torque and a rotational resistance. Based on the numerical data, the analytical functions of the torque and angular velocity of a rotating fan in terms of Knudsen number are quantitatively constructed. This relationship is used to explain the experimental observation of the Knudsen number shift for the appearance of the maximum torque and the maximum rotational speed in the transitional flow regime. (C) 2012 American Institute of Physics. [http://dx.doi.orgt10.1063/1.4765353]MechanicsPhysics, Fluids & PlasmasSCI(E)EI6ARTICLE11null2
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
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