11 research outputs found
Electron impact fragmentation of cytosine: partial ionization cross sections for positive fragments
We have measured mass spectra for positive ions produced by low-energy electron impact on cytosine using a reflectron time-of-flight mass spectrometer. The electron impact energy has been varied from 0 to 100 eV in steps of 0.5 eV. Ion yield curves of most of the fragment ions have been determined by fitting groups of adjacent peaks in the mass spectra with sequences of normalized Gaussians. The ion yield curves have been normalized by comparing the sum of the ion yields to the average of calculated total ionization cross sections. Appearance energies of the fragment ions have been determined, showing that the fragments 68 u–84 u have appearance energies between 10 and 11 eV, whereas fragments of 55 u and lower mass all have appearance energies above 12 eV. Most of the ion yields of 55 u and smaller show multiple onsets. Several groups of fragments have ion yield curves with nearly the same shape, clearly indicating the relevance of tautomerization in the fragmentation of cytosine
Similar Sensitivity to Ladder Contours in Macular Degeneration Patients and Controls - Table 1
<p><b>AMD</b>: Age-related Macular Degeneration; <b>SG</b>: Stargardt's; <b>c&r</b>: cone and rod dystrophy; <b>NC</b>: North Carolina dystrophy. <b>PRL ecc</b> indicates estimated PRL eccentricity or, in normals, distance of the fixation target from the center of the contour display. <b>loc</b> indicates the location of the target in the visual field, relative to the fovea. <b>MAR</b>–minimum angle of resolution in arcminutes. The last four columns are d' values for performance in completed blocks of the experiment, the same data plotted in <b><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0128119#pone.0128119.g002" target="_blank">Fig 2</a></b> x’s indicate inability to complete a block of trials for a given condition.</p><p>Similar Sensitivity to Ladder Contours in Macular Degeneration Patients and Controls - Table 1 </p
Correlations with subjects' PSF.
<p>Upper row: Correlations of the averaged Positive or Negative PSFs with the subject's PSF a) for the highest ranked only and b) for all PSFs. Lower row: Correlations of the individual Positive or Negative PSFs with the subject's PSF c) for the highest ranked PSFs only and d) for all PSFs. The red crosses show the average of all the individual correlations of the 100 PSFs with the subject's natural PSF of the eye under test. Significant differences between Positive and Negative PSFs were found in all cases; * stands for significance at p<0.05; ** p<0.005 (t-test). Dashed lines and symbols correspond to the simulated ideal responses, based on correlations with the subject's PSF. Positive responses in blue, and negative responses in yellow.</p
Multiple Modernities of Same-Sex Sexuality in Nigeria
The workshop gathered 26 scholars from 9 ESF member states, Nigeria and the U.S.A. to engage in interdisciplinary dialogue about the social crises to which sexual politics have been linked in Nigeria. While a wide range of topics were discussed in different panels that extended across the three-day duration of the event, questions about the definition, translation and circulation of same-sex vocabularies recurred with specific attention to what exists and takes place outside the purview of the state. A central concern of the participants was to find ways of recognizing and representing same-sex desire and practice in Nigeria and in other parts of the so-called developing world without, at the same time, condoning the unilateral dissemination of Western gender/sexual codes through universal human rights instruments. Some of the workshop participants prioritized the histories of “real people” for exploring the multiplicities of cultures and bodily capacities. Others preferred to make recourse to queer theoretical models as a means of undoing the mechanisms which hinder our ability to perceive human multiplicity. On the whole, it was agreed that African populations have tended to resist the idea that sexuality defines the whole person and that contemporary international LGBT discourses have not sufficiently addressed the complexities of African cultural responses to the sexual question. Other sets of relations that may elude gender/sexual categorization may need to be established in order to promote and protect sexual freedoms in globalizing contexts. A qualified emphasis was placed on “the customary” in Africa as a potential archive of “other ways of doing things”
Classification Orientation Plots from simulated responses.
<p>Ideal Positive (green, upper row) and Negative (red, mid row) Classification Orientation Plots computed from the simulated responses for each subject. The axis of the fitting ellipses and their corresponding angles φ are also shown (lower row, green for positive and dashed-red for negative). The subject's natural PSF Orientation Plot (blue) and axis are shown for reference.</p
Subject's natural PSF and Positive and Negative averaged PSFs.
<p>Subject's natural PSF (first row), averaged PSFs of the 10 best positive (middle row) and of the 10 best negative (last row) for each subject. The corresponding coefficients of correlation (r) between Subject's natural PSF and the Averaged Positive and Negative PSFs are shown in each panel.</p
Subject's PSF and Classification Maps.
<p>(1) Subjects' natural PSF; (2) Subject's Sampled PSF in angular sectors; (3) Corresponding PSF Orientation Plot (along with the axis of the fitted ellipses and eccentricities) and (4) the Classification Maps obtained from the subject's responses and all the 100 PSFs. Correlations between the Classification Map and the subject's Sampled PSF are shown in insets.</p
Classification Orientation Plots from subjects' responses.
<p>Positive (green) and Negative (red) Classification Orientation Plots, along with subject's natural PSF Orientation Plot (blue) for all subjects and the representation of the orientation of the fitting ellipses for the subject's PSF (blue), the positive internally coded PSF (green) and the negative internally coded PSF (dashed-red). The angle (φ) for each fitted ellipse is depicted in the corresponding graph.</p
Illustration of the Classification Maps orientation analysis.
<p>(1) Construction of the Positive and Negative Classification Maps from the total Classification Map, (2) considering absolute values, (3) Polar plot representation of Positive and Negative Orientation Classification Plots, (4) main axis of the fitting ellipse and eccentricities (e = 0.88 for positive and 0.98 for negative). Example is shown for subject S4.</p
Illustration of the PSF orientation analysis.
<p>(a) Subject's PSF; (b) Sampled PSF Map in 72 angular sectors. The integrated intensity values are normalized to 1; (c) Corresponding polar plot of the Sampled PSF Map (Orientation Plot); (d) The orientation of the PSF is given by the axis of the fitting ellipse (where the angle represents the main axis of the ellipse and the line length the eccentricity e of the ellipse (e = 0.98). Data are for S4).</p