2,748 research outputs found
Observations from a prospective small cohort study suggest that CGRP genes contribute to acute posttraumatic headache burden after concussion
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 (0â6) 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 Ï2-tests revealed that 88% of those with return-to play (RTP) exclusions â„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
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
Imaging stress and magnetism at high pressures using a nanoscale quantum sensor
Pressure alters the physical, chemical and electronic properties of matter.
The development of the diamond anvil cell (DAC) enables tabletop experiments to
investigate a diverse landscape of high-pressure phenomena ranging from the
properties of planetary interiors to transitions between quantum mechanical
phases. In this work, we introduce and utilize a novel nanoscale sensing
platform, which integrates nitrogen-vacancy (NV) color centers directly into
the culet (tip) of diamond anvils. We demonstrate the versatility of this
platform by performing diffraction-limited imaging (~600 nm) of both stress
fields and magnetism, up to pressures ~30 GPa and for temperatures ranging from
25-340 K. For the former, we quantify all six (normal and shear) stress
components with accuracy GPa, offering unique new capabilities for
characterizing the strength and effective viscosity of solids and fluids under
pressure. For the latter, we demonstrate vector magnetic field imaging with
dipole accuracy emu, enabling us to measure the pressure-driven
phase transition in iron as well as the complex
pressure-temperature phase diagram of gadolinium. In addition to DC vector
magnetometry, we highlight a complementary NV-sensing modality using T1 noise
spectroscopy; crucially, this demonstrates our ability to characterize phase
transitions even in the absence of static magnetic signatures. By integrating
an atomic-scale sensor directly into DACs, our platform enables the in situ
imaging of elastic, electric and magnetic phenomena at high pressures.Comment: 18 + 50 pages, 4 + 19 figure
100 kV Schottky electron gun
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 electronâbeam patterning of xâray 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 145â245 mm with a magnification of 1.15. The emitter, of apex radius âŒ0.6 ÎŒm 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 XâY 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 ÎŒA 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
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. ÎŽ15N 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 ÎŽ34S 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
We calculate the contribution of superconducting fluctuations above the
critical temperature to the transverse thermoelectric response
, 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 , the dominant contribution
to 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 .Comment: 11 pages, 5 figure
Circulating adrenomedullin estimates survival and reversibility of organ failure in sepsis: the prospective observational multinational Adrenomedullin and Outcome in Sepsis and Septic Shock-1 (AdrenOSS-1) study
Background: Adrenomedullin (ADM) regulates vascular tone and endothelial permeability during sepsis. Levels of circulating biologically active ADM (bio-ADM) show an inverse relationship with blood pressure and a direct relationship with vasopressor requirement. In the present prospective observational multinational Adrenomedullin and Outcome in Sepsis and Septic Shock 1 (, AdrenOSS-1) study, we assessed relationships between circulating bio-ADM during the initial intensive care unit (ICU) stay and short-term outcome in order to eventually design a biomarker-guided randomized controlled trial. Methods: AdrenOSS-1 was a prospective observational multinational study. The primary outcome was 28-day mortality. Secondary outcomes included organ failure as defined by Sequential Organ Failure Assessment (SOFA) score, organ support with focus on vasopressor/inotropic use, and need for renal replacement therapy. AdrenOSS-1 included 583 patients admitted to the ICU with sepsis or septic shock. Results: Circulating bio-ADM levels were measured upon admission and at day 2. Median bio-ADM concentration upon admission was 80.5 pg/ml [IQR 41.5-148.1 pg/ml]. Initial SOFA score was 7 [IQR 5-10], and 28-day mortality was 22%. We found marked associations between bio-ADM upon admission and 28-day mortality (unadjusted standardized HR 2.3 [CI 1.9-2.9]; adjusted HR 1.6 [CI 1.1-2.5]) and between bio-ADM levels and SOFA score (p < 0.0001). Need of vasopressor/inotrope, renal replacement therapy, and positive fluid balance were more prevalent in patients with a bio-ADM > 70 pg/ml upon admission than in those with bio-ADM †70 pg/ml. In patients with bio-ADM > 70 pg/ml upon admission, decrease in bio-ADM below 70 pg/ml at day 2 was associated with recovery of organ function at day 7 and better 28-day outcome (9.5% mortality). By contrast, persistently elevated bio-ADM at day 2 was associated with prolonged organ dysfunction and high 28-day mortality (38.1% mortality, HR 4.9, 95% CI 2.5-9.8). Conclusions: AdrenOSS-1 shows that early levels and rapid changes in bio-ADM estimate short-term outcome in sepsis and septic shock. These data are the backbone of the design of the biomarker-guided AdrenOSS-2 trial. Trial registration: ClinicalTrials.gov, NCT02393781. Registered on March 19, 2015
Measurement of the cross-section and charge asymmetry of bosons produced in proton-proton collisions at TeV with the ATLAS detector
This paper presents measurements of the and cross-sections and the associated charge asymmetry as a
function of the absolute pseudorapidity of the decay muon. The data were
collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with
the ATLAS experiment at the LHC and correspond to a total integrated luminosity
of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements
varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the
1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured
with an uncertainty between 0.002 and 0.003. The results are compared with
predictions based on next-to-next-to-leading-order calculations with various
parton distribution functions and have the sensitivity to discriminate between
them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables,
submitted to EPJC. All figures including auxiliary figures are available at
https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13
Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in âs=13âTeV pp collisions with the ATLAS detector
A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of âs=13ââTeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139ââfbâ1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015â2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV
Detection of a gammaretrovirus, XMRV, in the human population: Open questions and implications for xenotransplantation
XMRV (xenotropic murine leukaemia virus-related virus) is a gammaretrovirus that has been detected in human patients with prostate carcinoma, chronic fatigue syndrome (CFS) and also in a small percentage of clinically healthy individuals. It is not yet clear whether the distribution of this virus is primarily limited to the USA or whether it is causally associated with human disease. If future investigations confirm a broad distribution of XMRV and its association with disease, this would have an impact on xenotransplantation of porcine tissues and organs. Xenotransplantation is currently being developed to compensate for the increasing shortage of human material for the treatment of tissue and organ failure but could result in the transmission of porcine pathogens. Maintenance of pathogen-free donor animals will dramatically reduce this risk, but some of the porcine endogenous retroviruses (PERVs) found in the genome of all pigs, can produce infectious virus and infect cultured human cells. PERVs are closely related to XMRV so it is critical to develop tests that discriminate between them. Since recombination can occur between viruses, and recombinants can exhibit synergism, recipients should be tested for XMRV before xenotransplantation
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