Precision Measurement of the Boron to Carbon Flux Ratio in Cosmic Rays from 1.9 GV to 2.6 TV with the Alpha Magnetic Spectrometer on the International Space Station

Knowledge of the rigidity dependence of the boron to carbon flux ratio (B/C) is important in understanding the propagation of cosmic rays. The precise measurement of the B/C ratio from 1.9 GV to 2.6 TV, based on 2.3 million boron and 8.3 million carbon nuclei collected by AMS during the first 5 years of operation, is presented. The detailed variation with rigidity of the B/C spectral index is reported for the first time. The B/C ratio does not show any significant structures in contrast to many cosmic ray models that require such structures at high rigidities. Remarkably, above 65 GV, the B/C ratio is well described by a single power law R[superscript Δ] with index Δ=-0.333±0.014(fit)±0.005(syst), in good agreement with the Kolmogorov theory of turbulence which predicts Δ=-1/3 asymptotically.National Science Foundation (U.S.) (Grants 1455202 and 1551980)Wyle Research (Firm) (Grant 2014/T72497)United States. National Aeronautics and Space Administration (NASA Earth and Space Science Fellowship Grant HELIO15F-0005

Antiproton Flux, Antiproton-to-Proton Flux Ratio, and Properties of Elementary Particle Fluxes in Primary Cosmic Rays Measured with the Alpha Magnetic Spectrometer on the International Space Station

International audienceA precision measurement by AMS of the antiproton flux and the antiproton-to-proton flux ratio inprimary cosmic rays in the absolute rigidity range from 1 to 450 GV is presented based on 3.49 × 105antiproton events and 2.42 × 109 proton events. The fluxes and flux ratios of charged elementary particlesin cosmic rays are also presented. In the absolute rigidity range ∼60 to ∼500 GV, the antiproton ¯p, protonp, and positron eþ fluxes are found to have nearly identical rigidity dependence and the electron e− fluxexhibits a different rigidity dependence. Below 60 GV, the ( ¯ p=p), ( ¯ p=eþ), and (p=eþ) flux ratios eachreaches a maximum. From ∼60 to ∼500 GV, the ( ¯ p=p), ( ¯ p=eþ), and (p=eþ) flux ratios show no rigiditydependence. These are new observations of the properties of elementary particles in the cosmos

Precision Measurement of the Boron to Carbon Flux Ratio in Cosmic Rays from 1.9 GV to 2.6 TV with the Alpha Magnetic Spectrometer on the International Space Station

Knowledge of the rigidity dependence of the boron to carbon flux ratio (B/C) is important in understanding the propagation of cosmic rays. The precise measurement of the B/C ratio from 1.9 GV to 2.6 TV, based on 2.3 million boron and 8.3 million carbon nuclei collected by AMS during the first 5 years of operation, is presented. The detailed variation with rigidity of the B/C spectral index is reported for the first time. The B/C ratio does not show any significant structures in contrast to many cosmic ray models that require such structures at high rigidities. Remarkably, above 65 GV, the B/C ratio is well described by a single power law RΔ with index Δ = −0.333 +/- 0.014(fit) +/- 0.005(syst), in good agreement with the Kolmogorov theory of turbulence which predicts Δ = −1/3 asymptotically.</p

Observation of Fine Time Structures in the Cosmic Proton and Helium Fluxes with the Alpha Magnetic Spectrometer on the International Space Station

International audienceWe present the precision measurement from May 2011 to May 2017 (79 Bartels rotations) of the proton fluxes at rigidities from 1 to 60 GV and the helium fluxes from 1.9 to 60 GV based on a total of $1 \times 10^9$ events collected with the Alpha Magnetic Spectrometer aboard the International Space Station. This measurement is in solar cycle 24, which has the solar maximum in April 2014. We observed that, below 40 GV, the proton flux and the helium flux show nearly identical fine structures in both time and relative amplitude. The amplitudes of the flux structures decrease with increasing rigidity and vanish above 40 GV. The amplitudes of the structures are reduced during the time period, which started one year after solar maximum, when the proton and helium fluxes steadily increase. Above $\sim 3$  GV the p/He flux ratio is time independent. We observed that below $\sim 3$  GV the ratio has a long-term decrease coinciding with the period during which the fluxes start to rise

Nurses' perceptions of aids and obstacles to the provision of optimal end of life care in ICU

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Comparison of the effects of epidural levobupivacaine with tramadol or morphine addition on postoperative analgesia following major abdominal surgery [Majör abdominal cerrahilerde postoperatif analjezi İçin epidural levobupivakaine İlave edilen tramadol İle morfin’in etkilerinin Karşılaştırılması]

Objective: The study was designed to compare the postoperative analgesic efficacy of epidural tramadol or epidural morphine as adjuvant to levobupivacaine in major abdominal surgery. Methods: Patients in ASA I-II group aged between 18 and 65 years were included in study. Epidural catheter was introduced. Patients were randomised into three groups to receive levobupivacaine (Group L), levobupivacaine+morphine (Group LM) and levobupivacaine+tramadol (Group LT). General anaesthesia was administered to all patients. The solution intended for Group L contained 25 mg 0.5% levobupivacaine+15 mL saline, that for Group LM contained 25 mg 0.5% levobupivacaine+14.5 mL salin+100 µg morphine and that for Group LT contained 25 mg 0.5% levobupivacaine+13 mL salin+100 mg tramadol, which was administered via epidural catheter as loading dose 30 min before the end of the operation. Patient-controlled analgesia device was connected to the epidural catheter for evaluating postoperative analgesia. Bolus dose was adjusted to 12 mg levobupivacaine in Group L, 12 mg levobupivacaine +1.2 mg morphine in Group LM and 12 mg levobupivacaine+12 mg tramadol in Group LT. Lock-out period was adjusted to 15 min in three groups. Quality of analgesia was evaluated using Visual Analogue Scale; administered and demand doses of levobupivacaine, morphine and tramadol were compared at 30 min, 1, 2, 6, 12 and 24 h postoperatively. Results: Visual Analogue Scale scores were significantly higher in Group L than Groups LM and LT. Nausea and vomiting observed in Group L were lesser than those in Groups LM and LT. Conclusion: Continuous epidural analgesia using levobupivacaine combined with morphine or tramadol is an effective method for managing postoperative analgesia in major abdominal surgery. © 2019 by Turkish Anaesthesiology and Intensive Care Society