5,081 research outputs found

    Oscillations in D-region absorption at periods of one to two months

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    One to two month oscillations in D-region absorption are found in seven years of daily f-min data from low latitude stations at Singapore (1N, 104E) and Rarotonga (21S, 160W). Coherency (cross-spectral) analyses reveal that solar flux variations account for much of the f-min variance at these periods. Over the range of periods from 10 to 200 days, statistically significant linear correlation is found between the f-min time series and contemporaneous 10.7 cm solar flux mearurements at periods of 16 to 19 days, the 26 to 29 day solar rotation band, and a broad band covering 43 to 80 day periods

    Introducing a new themed collection on emerging technologies for research models of human neuronal disorders in vivo and in vitro

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    This themed collection of articles was prompted by a collaboration between Neuronal Signaling and the British Neuroscience Association. The Biochemical Society and Portland Press organised a symposium at the BNA Festival of Neuroscience in 2021, focused on the development and use of experimental models of human neuronal disorders. One aspect dealt with how new technologies are being (or could be) used both as a substitute for, or to complement, research that uses whole animal models. Another aspect discussed factors that need to be considered when appraising the validity of animal models of complex, multifactorial neuronal disorders. Given its relevance to the scope of Neuronal Signaling, the journal’s Editorial Board developed a themed collection of content around this symposium entitled Emerging technologies for research models of human neuronal disorders in vivo and in vitro. We were delighted that speakers from the symposium and other experts working in this field agreed to submit reviews for the collection, which offers an invaluable resource both for researchers who are already experts in this field and those who need merely to learn about its scope and potential

    The Black Student Movement at the Ohio State University

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    Black/African American alumni from Ohio State University in Columbus, OH are collective subjects in this research. The study has sought to discern and explicate the behaviors, experiences and attitudes of former Black students, now alumni, to effectively privilege their voices and viewpoints, which were previously not included in the scholarship and literature of African American Studies or Higher Education about the historic 1960s and 1970s. Determining how alumni experienced the Black Student Movement at Ohio State during the 1960s and 1970s has been the principal objective. Black students’ experiences and motivations were very different than popular Black Student Movement discourse suggests. Findings indicate Black students’ organized social activist behavior persisted effectively and sufficiently to be considered an example of modern social movements, worthy of respect like other social movements which have helped improve human conditions not only for themselves, but also for others including non-Black students at traditionally white institutions

    Distant galaxy clusters in the COSMOS field found by HIROCS

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    We present the first high-redshift galaxy cluster candidate sample from the HIROCS survey found in the COSMOS field. It results from a combination of public COSMOS with proprietary H-band data on a 0.66 square degree part of the COSMOS field and comprises 12 candidates in the redshift range 1.23 < z < 1.55. We find an increasing fraction of blue cluster members with increasing redshift. Many of the blue and even some of the reddest member galaxies exhibit disturbed morphologies as well as signs of interaction.Comment: 5 pages, 5 figures, in print format, accepted for publication by A&A Letter

    Characteristics of the Menstrual Cycle After Discontinuation of Oral Contraceptives

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    Background: Menstrual cycle function may continue to be altered after discontinuation of oral contraceptives (OC). Few studies have been published on the effects of recent OC use on menstrual cycle parameters; none have examined characteristics of the menstrual flow or the quality of cervical mucus. The purpose of this retrospective matched cohort study is to assess biomarkers of the menstrual cycle after discontinuation of OCs. Methods: Among a sample of women who daily recorded observations of menstrual cycle biomarkers, 70 women who had recently discontinued OCs were randomly matched by age and parity with 70 women who had not used OCs for at least 1 year. Outcomes investigated included overall cycle length, length of the luteal phase, estimated day of ovulation, duration of menstrual flow, menstrual intensity, and mucus score. Differences between recent OC users and controls were assessed using random effects modeling. Results: Recent OC users had statistically significantly lower scores for mucus quality for cycles 1 and 2. Additionally, OC users had a later estimated day of ovulation that was statistically significant in cycle 2 and a decreased intensity of menstrual flow that was significant in the first four cycles (difference = −0.48 days). In random effects modeling, all these parameters were significantly different for the first six cycles combined. Conclusions: Menstrual cycle biomarkers are altered for at least two cycles after discontinuation of OCs, and this may help explain the temporary decrease in fecundity associated with recent OC use

    Apoptosis and Clearance of the Secretory Mammary Epithelium

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    VLT Spectroscopy of the z=4.11 Radio Galaxy TN J1338-1942

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    We present optical, infrared and radio data of the z=4.11 radio galaxy TN J1338-1942, including an intermediate resolution spectrum obtained with FORS1on the VLT Antu telescope. TN J1338-1942 was the first z>4 radio galaxy to be discovered in the southern hemisphere and is one of the most luminous Ly-alpha objects in its class. The Ly-alpha and rest-frame optical emission appear co-spatial with the brightest radio hotspot of this very asymmetric radio source, suggesting extremely strong interaction with dense ambient clouds. The VLT observations are sufficiently sensitive to detect the continuum flux both blue-ward and red-ward of the Ly-alpha emission, allowing us to measure the Ly-alpha forest continuum break (Ly-alpha 'discontinuity', D_A) and the Lyman limit. We measure a D_A=0.37+-0.1, which is ~0.2 lower than the values found for quasars at this redshift. We interpret this difference as possibly due to a bias towards large D_A introduced in high--redshift quasar samples that are selected on the basis of specific optical colors. If such a bias would exist in optically selected quasars, - and even in samples of Lyman break galaxies -, then the space density of both classes of object will be underestimated. Furthermore, the average HI column density along cosmological lines of sight as determined using quasar absorption lines would be overestimated. Because of their radio-based selection, we argue that z>4 radio galaxies are excellent objects for investigating D_A statistics. [abridged]Comment: 6 Pages, including 4 PostScript figures. Accepted for publication in the Astronomy & Astrophysics Letter

    Friction and Wear Characteristics of a Modified Composite Solid Lubricant Plasma Spray Coating

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    LCR304 is a solid lubricant coating composed of Ni-10Cr, Cr2O3, BaF2-CaF2 and Ag and developed for dimensional stability in high temperature air. This coating is a modification of PS304, which differs in that the Ni-Cr constituent contains 20wt% Cr. The tribological characteristics of LCR304 were evaluated by pin-on-disk and foil air bearing rig testing from 25 to 650 C and compared to previous test results with PS304. For both tests, the friction coefficient decreased as temperature increased from 25 to 650 C. Wear generally decreased with increasing temperature for all pin-on-disk tests. LCR304 coated components produced the least wear of Inconel X-750 counterface materials at 427 and 650 C. These results indicate that the LCR304 coating has potential as a replacement for PS304 in, for example, low cycle (minimum wear) applications where dimensional stability is imperative
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