997 research outputs found

    One-neutron knockout from 57^{57}Ni

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    The single-particle structure of 57^{57}Ni and level structure of 56^{56}Ni were investigated with the \mbox{9^{9}Be (57^{57} Ni,56^{56}Ni+γ\gamma)X\it{X}} reaction at 73 MeV/nucleon. An inclusive cross section of 41.4(12) mb was obtained for the reaction, compared to a theoretical prediction of 85.4 mb, hence only 48(2)% of the theoretical cross section is exhausted. This reduction in the observed spectroscopic strength is consistent with that found for lighter well-bound nuclei. One-neutron removal spectroscopic factors of 0.58(11) to the ground state and 3.7(2) to all excited states of 56^{56}Ni were deduced.Comment: Phys. Rev. C, accepte

    A spontaneous increase in intracellular Ca2+ in metaphase II human oocytes in vitro can be prevented by drugs targeting ATP-sensitive K+ channels

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    STUDY QUESTION: Could drugs targeting ATP-sensitive K+ (KATP) channels prevent any spontaneous increase in intracellular Ca2+ that may occur in human metaphase II (MII) oocytes under in vitro conditions? SUMMARY ANSWER: Pinacidil, a KATP channel opener, and glibenclamide, a KATP channel blocker, prevent a spontaneous increase in intracellular Ca2+ in human MII oocytes. WHAT IS KNOWN ALREADY: The quality of the oocyte and maintenance of this quality during in vitro processing in the assisted reproductive technology (ART) laboratory is of critical importance to successful embryo development and a healthy live birth. Maintenance of Ca2+ homeostasis is crucial for cell wellbeing and increased intracellular Ca2+ levels is a well-established indicator of cell stress. STUDY DESIGN, SIZE, DURATION: Supernumerary human oocytes (n = 102) collected during IVF/ICSI treatment that failed to fertilize were used from October 2013 to July 2015. All experiments were performed on mature (MII) oocytes. Dynamics of intracellular Ca2+ levels were monitored in oocytes in the following experimental groups: (i) Control, (ii) Dimethyl sulfoxide (DMSO; used to dissolve pinacidil, glibenclamide and 2,4-Dinitrophenol (DNP)), (iii) Pinacidil, (iv) Glibenclamide, (v) DNP: an inhibitor of oxidative phosphorylation, (vi) Pinacidil and DNP and (vii) Glibenclamide and DNP. PARTICIPANTS/MATERIALS/SETTINGS/METHODS: Oocytes were collected under sedation as part of routine treatment at an assisted conception unit from healthy women (mean ± SD) age 34.1 ± 0.6 years, n = 41. Those surplus to clinical use were donated for research. Oocytes were loaded with Fluo-3 Ca2+-sensitive dye, and monitored by laser confocal microscopy for 2 h at 10 min intervals. Time between oocyte collection and start of Ca2+ monitoring was 80.4 ± 2.1 h. MAIN RESULTS AND THE ROLE OF CHANCE: Intracellular levels of Ca2+ increased under in vitro conditions with no deliberate challenge, as shown by Fluo-3 fluorescence increasing from 61.0 ± 11.8 AU (AU = arbitrary units; n = 23) to 91.8 ± 14.0 AU (n = 19; P <0.001) after 2 h of monitoring. Pinacidil (100 µM) inhibited this increase in Ca2+ (85.3 ± 12.3 AU at the beginning of the experiment, 81.7 ± 11.0 AU at the end of the experiment; n = 13; P = 0.616). Glibenclamide (100 µM) also inhibited the increase in Ca2+ (74.7 ± 10.6 AU at the beginning and 71.8 ± 10.9 AU at the end of the experiment; n = 13; P = 0.851. DNP (100 mM) induced an increase in intracellular Ca2+ that was inhibited by glibenclamide (100 µM; n = 9) but not by pinacidil (100 µM; n = 5). LIMITATIONS, REASONS FOR CAUTION: Owing to clinical and ethical considerations, it was not possible to monitor Ca2+ in MII oocytes immediately after retrieval. MII oocytes were available for our experimentation only after unsuccessful IVF or ICSI, which was, on average, 80.4 ± 2.1 h (n = 102 oocytes) after the moment of retrieval. As the MII oocytes used here were those that were not successfully fertilized, it is possible that they may have been abnormal with impaired Ca2+ homeostasis and, furthermore, the altered Ca2+ homeostasis might have been associated solely with the protracted incubation. WIDER IMPLICATIONS OF THE FINDINGS: These results show that maintenance of oocytes under in vitro conditions is associated with intracellular increase in Ca2+, which can be counteracted by drugs targeting KATP channels. As Ca2+ homeostasis is crucial for contributing to a successful outcome of ART, these results suggest that KATP channel openers and blockers should be tested as drugs for improving success rates of ART

    Multiple-spin coherence transfer in linear Ising spin chains and beyond: numerically-optimized pulses and experiments

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    We study multiple-spin coherence transfers in linear Ising spin chains with nearest neighbor couplings. These constitute a model for efficient information transfers in future quantum computing devices and for many multi-dimensional experiments for the assignment of complex spectra in nuclear magnetic resonance spectroscopy. We complement prior analytic techniques for multiple-spin coherence transfers with a systematic numerical study where we obtain strong evidence that a certain analytically-motivated family of restricted controls is sufficient for time-optimality. In the case of a linear three-spin system, additional evidence suggests that prior analytic pulse sequences using this family of restricted controls are time-optimal even for arbitrary local controls. In addition, we compare the pulse sequences for linear Ising spin chains to pulse sequences for more realistic spin systems with additional long-range couplings between non-adjacent spins. We experimentally implement the derived pulse sequences in three and four spin systems and demonstrate that they are applicable in realistic settings under relaxation and experimental imperfections-in particular-by deriving broadband pulse sequences which are robust with respect to frequency offsets.Comment: 11 page

    Sight Distance Standards Based On Observational Data Risk Evaluation Of Passing

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    The paper presents an application of a reliability analysis for evaluating the risk associated with passing sight distance (PSD) standards in terms of the expected probability of noncompliance. Calculation of PSD is required to determine where drivers can safely execute passing maneuvers. Traditional PSD standards are based on deterministic, theoretical models, which are calibrated with conservative percentile values for uncertain design inputs to account for uncertainty. The PSD standards do not provide information about the risk of deviation from them. Reliability analysis is a technique that is based on limit state design and that accounts for the propagation of variability from input random parameters to the design outputs. A total of 1,098 passing maneuvers were observed on several two-lane highways in Spain; two data collection methodologies were used: external observations and an instrumented vehicle. The most significant factors affecting PSD were impeding-vehicle speed, passing-vehicle acceleration, and head-ways between impeding and passing vehicles. A uniform acceleration model described the passing-vehicle trajectory. The characterized input parameters and the passing model were used to perform a reliability analysis. The results showed the probability of noncompliance in different scenarios, defined as the proportion of cases in which the required PSD would exceed the available sight distance. American and Spanish PSD standards were evaluated. Geometric design standards presented a probability of noncompliance of about 0.15, whereas some marking standards had a probability of noncompliance exceeding 0.85. These standards may be associated with higher risk levels if they are followed by drivers. As well, PSD risk levels were not consistent for different design speeds, since they underestimated operating speed at some locationsThis paper was developed as a result of a mobility study at the University of British Columbia funded by the Erasmus Mundus Program of the European Commission under the Transatlantic Partnership for Excellence in Engineering project. The authors thank the Spanish Ministry of Economy and Competitiveness, which subsidized the research project, and the Spanish Directorate General of Traffic, Spanish Ministry of Public Works, Valencia Regional Department of Transport, and Valencia province road department for their collaboration during the field study.Llorca Garcia, C.; Moreno Chou, AT.; Sayed, T.; García García, A. (2014). Sight Distance Standards Based On Observational Data Risk Evaluation Of Passing. Transportation research record. 2404:18-26. doi:10.3141/2404-03S18262404Ismail, K., & Sayed, T. (2009). Risk-based framework for accommodating uncertainty in highway geometric design. Canadian Journal of Civil Engineering, 36(5), 743-753. doi:10.1139/l08-146Ismail, K., & Sayed, T. (2010). Risk-Based Highway Design. Transportation Research Record: Journal of the Transportation Research Board, 2195(1), 3-13. doi:10.3141/2195-01Richl, L., & Sayed, T. (2006). Evaluating the Safety Risk of Narrow Medians Using Reliability Analysis. Journal of Transportation Engineering, 132(5), 366-375. doi:10.1061/(asce)0733-947x(2006)132:5(366)Harwood, D. W., Gilmore, D. K., & Richard, K. R. (2010). Criteria for Passing Sight Distance for Roadway Design and Marking. Transportation Research Record: Journal of the Transportation Research Board, 2195(1), 36-46. doi:10.3141/2195-05Wang, Y., & Cartmell, M. P. (1998). New Model for Passing Sight Distance on Two-Lane Highways. Journal of Transportation Engineering, 124(6), 536-545. doi:10.1061/(asce)0733-947x(1998)124:6(536)Polus, A., Livneh, M., & Frischer, B. (2000). Evaluation of the Passing Process on Two-Lane Rural Highways. Transportation Research Record: Journal of the Transportation Research Board, 1701(1), 53-60. doi:10.3141/1701-07Llorca, C., & García, A. (2011). Evaluation of Passing Process on Two-Lane Rural Highways in Spain with New Methodology Based on Video Data. Transportation Research Record: Journal of the Transportation Research Board, 2262(1), 42-51. doi:10.3141/2262-05Carlson, P., Miles, J., & Johnson, P. (2006). Daytime High-Speed Passing Maneuvers Observed on Rural Two-Lane, Two-Way Highway: Findings and Implications. Transportation Research Record: Journal of the Transportation Research Board, 1961, 9-15. doi:10.3141/1961-02Llorca, C., Moreno, A. T., García, A., & Pérez-Zuriaga, A. M. (2013). Daytime and Nighttime Passing Maneuvers on a Two-Lane Rural Road in Spain. Transportation Research Record: Journal of the Transportation Research Board, 2358(1), 3-11. doi:10.3141/2358-01Easa, S. M. (1993). Reliability‐Based Design of Intergreen Interval at Traffic Signals. Journal of Transportation Engineering, 119(2), 255-271. doi:10.1061/(asce)0733-947x(1993)119:2(255)Selvanathan, E. A., & Selvanathan, S. (1994). The demand for transport and communication in the United Kingdom and Australia. Transportation Research Part B: Methodological, 28(1), 1-9. doi:10.1016/0191-2615(94)90027-2Easa, S. M. (2000). Reliability Approach to Intersection Sight Distance Design. Transportation Research Record: Journal of the Transportation Research Board, 1701(1), 42-52. doi:10.3141/1701-06Ibrahim, S. E.-B., & Sayed, T. (2011). Developing safety performance functions incorporating reliability-based risk measures. Accident Analysis & Prevention, 43(6), 2153-2159. doi:10.1016/j.aap.2011.06.006Khoury, J. E., & Hobeika, A. G. (2007). Assessing the Risk in the Design of Passing Sight Distances. Journal of Transportation Engineering, 133(6), 370-377. doi:10.1061/(asce)0733-947x(2007)133:6(370)Khoury, J. E., & Hobeika, A. G. (2012). Integrated Stochastic Approach for Risk and Service Estimation: Passing Sight Distance Application. Journal of Transportation Engineering, 138(5), 571-579. doi:10.1061/(asce)te.1943-5436.0000366Kim, S., & Choi, J. (2013). Effects of preceding geometric conditions on operating speed consistency of multilane highways. Canadian Journal of Civil Engineering, 40(6), 528-536. doi:10.1139/cjce-2012-005

    Effect of pioglitazone treatment in a patient with secondary multiple sclerosis

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    BACKGROUND: Ligands of the peroxisome proliferator-activated receptor-gamma (PPARγ) induce apoptosis in activated T-lymphocytes and exert anti-inflammatory effects in glial cells. Preclinical studies have shown that the thiazolidinedione pioglitazone, an FDA-approved PPARγ agonist used to treat type 2 diabetes, delays the onset and reduces the severity of clinical symptoms in experimental autoimmune encephalomyelitis, an animal model of multiple sclerosis (MS). We therefore tested the safety and therapeutic potential of oral pioglitazone in a patient with secondary MS. CASE PRESENTATION: The rationale and risks of taking pioglitazone were carefully explained to the patient, consent was obtained, and treatment was initiated at 15 mg per day p.o. and then increased by 15 mg biweekly to 45 mg per day p.o. for the duration of the treatment. Safety was assessed by measurements of metabolic profiles, blood pressure, and edema; effects on clinical symptoms were assessed by measurement of cognition, motor function and strength, and MRI. Within 4 weeks the patient exhibited increased appetite, cognition and attention span. After 12 months treatment, body weight increased from 27.3 to 35.9 kg (32%) and maintained throughout the duration of the study. Upper extremity strength and coordination improved, and increased fine coordination was noted unilaterally after 8 months and bilaterally after 15 months. After 8 months therapy, the patient demonstrated improvement in orientation, short-term memory, and attention span. MRIs carried out after 10 and 18 months of treatment showed no perceptible change in overall brain atrophy, extent of demyelination, or in Gd-enhancement. After 3.0 years on pioglitazone, the patient continues to be clinically stable, with no adverse events. CONCLUSIONS: In a patient with secondary progressive MS, daily treatment with 45 mg p.o. pioglitazone for 3 years induced apparent clinical improvement without adverse events. Pioglitazone should therefore be considered for further testing of therapeutic potential in MS patients

    Islands in the landscape

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    The string theory landscape consists of many metastable de Sitter vacua, populated by eternal inflation. Tunneling between these vacua gives rise to a dynamical system, which asymptotically settles down to an equilibrium state. We investigate the effects of sinks to anti-de Sitter space, and show how their existence can change probabilities in the landscape. Sinks can disturb the thermal occupation numbers that would otherwise exist in the landscape and may cause regions that were previously in thermal contact to be divided into separate, thermally isolated islands.Comment: 31 pages, 8 figure

    New pathway to bypass the 15O waiting point

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    We propose the sequential reaction process 15^{15}O(pp,γ)(β+\gamma)(\beta^{+})16^{16}O as a new pathway to bypass of the 15^{15}O waiting point. This exotic reaction is found to have a surprisingly high cross section, approximately 1010^{10} times higher than the 15^{15}O(pp,β+\beta^{+})16^{16}O. These cross sections were calculated after precise measurements of energies and widths of the proton-unbound 16^{16}F low lying states, obtained using the H(15^{15}O,p)15^{15}O reaction. The large (p,γ)(β+)(p,\gamma)(\beta^{+}) cross section can be understood to arise from the more efficient feeding of the low energy wing of the ground state resonance by the gamma decay. The implications of the new reaction in novae explosions and X-ray bursts are discussed.Comment: submitte

    Relationship between body mass index, cardiovascular biomarkers and incident heart failure

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    BACKGROUND: There are limited data examining whether body-mass index (BMI) influences the association between cardiovascular biomarkers and incident heart failure (HF). METHODS AND RESULTS: Thirteen biomarkers representing key HF domains were measured: N-terminal-pro-B-type natriuretic peptide (NT-proBNP), mid-regional-pro-A-type natriuretic peptide (MR-proANP), cardiac troponin-T (cTnT), C-reactive protein, procalcitonin, galectin-3, C-terminal pro-endothelin-1 (CT-pro-ET-1), mid-regional pro-adrenomedullin, plasminogen activator inhibitor-1, copeptin, renin, aldosterone and cystatin-C. Associations of biomarkers with BMI were examined using linear regression models, and with incident HF using Cox regression models. We selected biomarkers significantly associated with incident HF, and evaluated whether BMI modified these associations. RESULTS: Among 8202 individuals, 41% were overweight (BMI 25-30kg/m2 ), and 16% were obese (BMI≥30kg/m2 ). Mean age of the cohort was 49 years (range 28-75), and 50% were women. All biomarkers except renin were associated with BMI: inverse associations were observed with NT-proBNP, MR-proANP, CT-pro-ET-1 and aldosterone whereas positive associations were observed with the remaining biomarkers (Pall ≤0.001). During 11.3±3.1 years follow-up, 357 HF events were recorded. Only NT-proBNP, MR-proANP and cTnT remained associated with incident HF (P0.1). Combined NT-proBNP and cTnT measurements modestly improved performance metrics of the clinical HF model in overweight (ΔC-statistic=0.024; LHRχ2 =38; P<0.001) and in obese (ΔC-statistic=0.020; LHRχ2 =32; P<0.001) individuals. CONCLUSIONS: Plasma concentrations of several cardiovascular biomarkers are influenced by obesity. Only NT-proBNP, MR-proANP and cTnT were associated with incident HF, and BMI did not modify these associations. A combination of NT-proBNP and cTnT improves HF risk prediction in overweight and in obese individuals. This article is protected by copyright. All rights reserved

    Egalitarian justice and expected value

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    According to all-luck egalitarianism, the differential distributive effects of both brute luck, which defines the outcome of risks which are not deliberately taken, and option luck, which defines the outcome of deliberate gambles, are unjust. Exactly how to correct the effects of option luck is, however, a complex issue. This article argues that (a) option luck should be neutralized not just by correcting luck among gamblers, but among the community as a whole, because it would be unfair for gamblers as a group to be disadvantaged relative to non-gamblers by bad option luck; (b) individuals should receive the warranted expected results of their gambles, except insofar as individuals blamelessly lacked the ability to ascertain which expectations were warranted; and (c) where societal resources are insufficient to deliver expected results to gamblers, gamblers should receive a lesser distributive share which is in proportion to the expected results. Where all-luck egalitarianism is understood in this way, it allows risk-takers to impose externalities on non-risk-takers, which seems counterintuitive. This may, however, be an advantage as it provides a luck egalitarian rationale for assisting ‘negligent victims’
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