2,869 research outputs found

    Temporal–spectral signaling of sensory information and expectations in the cerebral processing of pain

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    The perception of pain is shaped by somatosensory information about threat. However, pain is also influenced by an individual's expectations. Such expectations can result in clinically relevant modulations and abnormalities of pain. In the brain, sensory information, expectations (predictions), and discrepancies thereof (prediction errors) are signaled by an extended network of brain areas which generate evoked potentials and oscillatory responses at different latencies and frequencies. However, a comprehensive picture of how evoked and oscillatory brain responses signal sensory information, predictions, and prediction errors in the processing of pain is lacking so far. Here, we therefore applied brief painful stimuli to 48 healthy human participants and independently modulated sensory information (stimulus intensity) and expectations of pain intensity while measuring brain activity using electroencephalography (EEG). Pain ratings confirmed that pain intensity was shaped by both sensory information and expectations. In contrast, Bayesian analyses revealed that stimulus-induced EEG responses at different latencies (the N1, N2, and P2 components) and frequencies (alpha, beta, and gamma oscillations) were shaped by sensory information but not by expectations. Expectations, however, shaped alpha and beta oscillations before the painful stimuli. These findings indicate that commonly analyzed EEG responses to painful stimuli are more involved in signaling sensory information than in signaling expectations or mismatches of sensory information and expectations. Moreover, they indicate that the effects of expectations on pain are served by brain mechanisms which differ from those conveying effects of sensory information on pain

    Observations from a prospective small cohort study suggest that CGRP genes contribute to acute posttraumatic headache burden after concussion

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    Introduction: Post-traumatic headache (PTH) is commonly reported after concussion. Calcitonin gene-related peptide (CGRP) is implicated in the pathogenesis of migraine. We explored how single nucleotide polymorphisms (SNPs) from CGRP-alpha (CALCA) and the receptor activity modifying protein-1 (RAMP1) related to headache burden during the first week after concussion. Methods: A prospective study was performed in 34 collegiate athletes who sustained a concussion. Participants completed the symptom evaluation checklist from the SCAT3 within 48 h of injury (V1), and again 4 (V2) and 7 (V3) days after injury. For each visit, the self-reported score (0–6) for headache, pressure in head, blurred vision, and sensitivity to light/noise were reported and summed to calculate the headache burden. A saliva sample was obtained and genotyped for CALCA (rs3781719) and RAMP1 (rs10185142). RAMP1 (TT, TC, CC) and CALCA (AA, AG, GG) were dichotomized (A+, A- and T+, T-, respectively), and concatenated (T+A+, T+A-, T-A+, T-A-) for analyses. Results: Headache Burden at Visit 1 was greatest in T+A+ compared to T-A+, and trended toward a significant difference with T+A-. Repeated-measures ANOVA revealed the presence of significant visit main effects (p < 0.001, η2 = 0.404), but the group (p = 0.055) and interaction effects only trended (p = 0.094). Pearson's χ2-tests revealed that 88% of those with return-to play (RTP) exclusions ≥15 days had PTH with multi-sensory symptoms (PTH+SENS) as compared to 35% in those with RTP < 14 day. Conclusion: Knowledge of RAMP1 and CALCA genotypes appear to improve an understanding the presenting features and magnitude of headache burden after concussion injury

    The detection of lubricating oil viscosity changes in gearbox transmission systems driven by sensorless variable speed drives using electrical supply parameters

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    Lubrication oil plays a decisive role to maintain a reliable and efficient operation of gear transmissions. Many offline methods have been developed to monitor the quality of lubricating oils. This work focus on developing a novel online method to diagnose oil degradation based on the measurements from power supply system to the gearbox. Experimental studies based on an 10kW industrial gearbox fed by a sensorless variable speed drive (VSD) shows that measurable changes in both static power and dynamic behaviour are different with lube oils tested. Therefore, it is feasible to use the static power feature to indicate viscosity changes at low and moderate operating speeds. In the meantime, the dynamic feature can separate viscosity changes for all different tested cases

    The Ursinus Weekly, June 5, 1961

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    198 diplomas sum up 4 Ursinus years: Prizes bestowed on outstanding Ursinus students • Sandberg \u2761 valedictorian; Graduates summa cum laude • Four honorary degrees awarded this morning: Robert N. Hilkert delivers address to Ursinus\u27 198 senior graduates • Roadside billboard inspiration for Hilkert\u27s speech • Cash prize given four cited for teaching merit • Barbara Pine wins scholarship; Her blindness no obstacle • Biology instructor leaves to tie up loose ends • Amigo to retire; Students\u27 friend for eleven years • Dr. Paisley\u27s death saddens commencement; Board President served Ursinus for 51 years • Newspaperman elected new trustee board head • September may bring 280 freshmen; U.C. Admissions Department reports • New Weekly ad manager wins Wayne Brown prize • Editorial: Sharpened incisors; Good luck • Ursinus in the past • Art of understanding • Seniors submit post-graduation plans; Many teach, work for further degrees • Lacrosse players undefeated again; Trample Drexel • Snell softballers post 3-2 log; Ask more games • Intramural corner • Wait\u27ll next year when nine starters return to diamond • Lynne Crosley lacrosse all-American first team • Netmen competent despite 3-5 log; Famous is MVP • Sport page outlet for creativity, magazine writes • Track team tallies 5-5 \u2761 record; Wise made captain • Morgan finally defeated; Moran wins in AAU run • Mrs. Shryock to retire; Mrs. Bugelholl plans move • Ursinus professor to attend nuclear session • Organizations list late election results • Ursinus College gets 92,000inLehighestateLatetracknews:Morganruns4:04.2inBoardwalkMileDr.Creagerreporteddoingwell;NeedsrestUrsinusawarded92,000 in Lehigh estate • Late track news: Morgan runs 4:04.2 in Boardwalk Mile • Dr. Creager reported doing well; Needs rest • Ursinus awarded 12,000 F. J. Clamer memorial fundhttps://digitalcommons.ursinus.edu/weekly/1344/thumbnail.jp

    100 kV Schottky electron gun

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    We present a comparison between experimental results and computer calculations on a high current, high resolution single lens electrostatic 100 kV Schottky electron gun. One promising application for such an electron gun is for direct electron‐beam patterning of x‐ray masks. The high energy helps provide precise patterning of the thick resist, maintains vertical resist profiles, and minimizes the proximity effect. The gun was designed to operate from 25 to 100 kV, capable of focus at a distance of 145–245 mm with a magnification of 1.15. The emitter, of apex radius ∼0.6 μm operated at 1800 K in the extended Schottky regime, provides an angular intensity of 0.5 mA/sr for an extraction voltage of 5000 V and with a beam limiting aperture of 2.2 mrad, the gun delivers 7 nA of probe current. The gun consists of a replaceable high voltage optic module mounted on a precision insulator with the main acceleration occurring between the exit of the optic module and the grounded anode. A provision is made for alignment of the emitter with respect to the central optical axis of the optic module in a special alignment chamber eliminating the need for high voltage emitter alignment. Final gun alignment is achieved by X–Y motion of the grounded anodeaperture. The gun is constructed to allow ease of replacement of the emitter, the beam defining aperture, and the differential pumping aperture. The beam supply has 10 ppm of ripple while lens supplies have supply, cabling, connectors,insulator, and optic module draw 1 μA of ground leakage current. Pressured SF6 chambers are used for high voltage connector interfaces within the power supply and on the gun

    Assigning stranded bottlenose dolphins to source stocks using stable isotope ratios following the Deepwater Horizon oil spill

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    The potential for stranded dolphins to serve as a tool for monitoring free-ranging populations would be enhanced if their stocks of origin were known. We used stable isotopes of carbon, nitrogen, and sulfur from skin to assign stranded bottlenose dolphins Tursiops truncatus to different habitats, as a proxy for stocks (demographically independent populations), following the Deepwater Horizon oil spill. Model results from biopsy samples collected from dolphins from known habitats (n = 205) resulted in an 80.5% probability of correct assignment. These results were applied to data from stranded dolphins (n = 217), resulting in predicted assignment probabilities of 0.473, 0.172, and 0.355 to Estuarine, Barrier Island (BI), and Coastal stocks, respectively. Differences were found west and east of the Mississippi River, with more Coastal dolphins stranding in western Louisiana and more Estuarine dolphins stranding in Mississippi. Within the Estuarine East Stock, 2 groups were identified, one predominantly associated with Mississippi and Alabama estuaries and another with western Florida. δ15N values were higher in stranded samples for both Estuarine and BI stocks, potentially indicating nutritional stress. High probabilities of correct assignment of the biopsy samples indicate predictable variation in stable isotopes and fidelity to habitat. The power of δ34S to discriminate habitats relative to salinity was essential. Stable isotopes may provide guidance regarding where additional testing is warranted to confirm demographic independence and aid in determining the source habitat of stranded dolphins, thus increasing the value of biological data collected from stranded individuals.Publisher PDFPeer reviewe

    Superconducting fluctuations and the Nernst effect: A diagrammatic approach

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    We calculate the contribution of superconducting fluctuations above the critical temperature TcT_c to the transverse thermoelectric response αxy\alpha_{xy}, the quantity central to the analysis of the Nernst effect. The calculation is carried out within the microscopic picture of BCS, and to linear order in magnetic field. We find that as TTcT \to T_c, the dominant contribution to αxy\alpha_{xy} arises from the Aslamazov-Larkin diagrams, and is equal to the result previously obtained from a stochastic time-dependent Ginzburg-Landau equation [Ussishkin, Sondhi, and Huse, arXiv:cond-mat/0204484]. We present an argument which establishes this correspondence for the heat current. Other microscopic contributions, which generalize the Maki-Thompson and density of states terms for the conductivity, are less divergent as TTcT \to T_c.Comment: 11 pages, 5 figure
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