1,226 research outputs found

    Blue emitting gold nanoclusters templated by poly-cytosine DNA at low pH and poly-adenine DNA at neutral pH

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    Blue fluorescent gold nanoclusters were prepared in the presence of poly-cytosine DNAs at low pH and poly-adenine at neutral pH using citrate as the reducing agent; various buffer conditions affecting the synthesis have been explored.University of Waterloo || Canadian Foundation for Innovation || Natural Sciences and Engineering Research Council || Ontario Ministry of Research and Innovation |

    The Rotating Quantum Thermal Distribution

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    We show that the rigidly rotating quantum thermal distribution on flat space-time suffers from a global pathology which can be cured by introducing a cylindrical mirror if and only if it has a radius smaller than that of the speed-of-light cylinder. When this condition is met, we demonstrate numerically that the renormalized expectation value of the energy-momentum stress tensor corresponds to a rigidly rotating thermal bath up to a finite correction except on the mirror where there are the usual Casimir divergences.Comment: 8 pages, 2 PostScript figure

    The relationship between early pregnancy dietary intakes and subsequent birthweight and neonatal adiposity

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    Background: Maternal nutrition intakes may influence neonatal birthweight and adiposity; however, inconsistencies within the literature exist. The relationships between maternal dietary intakes in early pregnancy and both birthweight and neonatal adiposity requires elucidation. This study examined the relationship between early pregnancy dietary intakes and subsequent birthweight and neonatal adiposity. Methods: Women were recruited at their convenience after sonographic confirmation of a singleton pregnancy. Women completed a Willet food frequency questionnaire evaluating habitual food and nutrient intakes at their first antenatal visit. Neonatal body composition was measured using air-displacement plethysmography. Results: Of the 385 mother-neonate dyads, mean maternal age was 30.8 ± 5.3 years, mean Body Mass Index (BMI) was 24.5 ± 4.8 kg/m2 and 41.8% (n = 161) were nulliparous. There were no relationships between maternal food intakes and birthweight (P \u3e 0.05) (n = 385). On multivariable analysis there was a positive relationship between polyunsaturated fat and neonatal fat mass index (FMI) (beta = 0.015, 95% CI = 0.002-0.028, P = 0.04) (n = 80). Conclusion: Dietary intakes of polyunsaturated fat in early pregnancy are positively associated with neonatal FMI at birth on multivariable analysis. Further longitudinal studies need to explore this association and the long-term implications for the neonate

    The Kentucky Noisy Monte Carlo Algorithm for Wilson Dynamical Fermions

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    We develop an implementation for a recently proposed Noisy Monte Carlo approach to the simulation of lattice QCD with dynamical fermions by incorporating the full fermion determinant directly. Our algorithm uses a quenched gauge field update with a shifted gauge coupling to minimize fluctuations in the trace log of the Wilson Dirac matrix. The details of tuning the gauge coupling shift as well as results for the distribution of noisy estimators in our implementation are given. We present data for some basic observables from the noisy method, as well as acceptance rate information and discuss potential autocorrelation and sign violation effects. Both the results and the efficiency of the algorithm are compared against those of Hybrid Monte Carlo. PACS Numbers: 12.38.Gc, 11.15.Ha, 02.70.Uu Keywords: Noisy Monte Carlo, Lattice QCD, Determinant, Finite Density, QCDSPComment: 30 pages, 6 figure

    No Evidence Supporting Flare Driven High-Frequency Global Oscillations

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    The underlying physics that generates the excitations in the global low-frequency, < 5.3 mHz, solar acoustic power spectrum is a well known process that is attributed to solar convection; However, a definitive explanation as to what causes excitations in the high-frequency regime, > 5.3 mHz, has yet to be found. Karoff and Kjeldsen (Astrophys. J. 678, 73-76, 2008) concluded that there is a correlation between solar flares and the global high-frequency solar acoustic waves. We have used the Global Oscillations Network Group (GONG) helioseismic data in an attempt to verify Karoff and Kjeldsen (2008) results as well as compare the post-flare acoustic power spectrum to the pre-flare acoustic power spectrum for 31 solar flares. Among the 31 flares analyzed, we observe that a decrease in acoustic power after the solar flare is just as likely as an increase. Furthermore, while we do observe variations in acoustic power that are most likely associated with the usual p-modes associated with solar convection, these variations do not show any significant temporal association with flares. We find no evidence that consistently supports flare driven high-frequency waves.Comment: 20 pages, 9 figures, Accepted for publication in Solar Physic

    Cavity QED and quantum information processing with "hot" trapped atoms

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    We propose a method to implement cavity QED and quantum information processing in high-Q cavities with a single trapped but non-localized atom. The system is beyond the Lamb-Dick limit due to the atomic thermal motion. Our method is based on adiabatic passages, which make the relevant dynamics insensitive to the randomness of the atom position with an appropriate interaction configuration. The validity of this method is demonstrated from both approximate analytical calculations and exact numerical simulations. We also discuss various applications of this method based on the current experimental technology.Comment: 14 pages, 8 figures, Revte

    Cosmological Solutions of Supergravity in Singular Spaces

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    We study brane-world solutions of five-dimensional supergravity in singular spaces. We exhibit a self-tuned four-dimensional cosmological constant when five-dimensional supergravity is broken by an arbitrary tension on the brane-world. The brane-world metric is of the FRW type corresponding to a cosmological constant ΩΛ=5/7\Omega_{\Lambda}={5/7} and an equation of state ω=5/7\omega=-{5/7} which are consistent with experiment.Comment: 11 pages, Late

    Breast feeding in Australia: A comparative study of Aboriginal and non Aboriginal women

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    The superiority of breast feeding over bottle feeding is universally acknowledged, and its crucial contribution to infant health is accepted by health authorities. Australia in recognition of the importance of breast feeding to infant health, aims to increase the prevalence of breast feeding. Breast feeding provides benefits for all children, however the health advantage that is gained by breast feeding in comparison to artificial feeding is more apparent among disadvantaged groups. Aboriginal Australians are identified as one such disadvantaged group. This study compares the available literature regarding the prevalence of breast feeding in Aboriginal and non Aboriginal women. It is apparent that breast feeding prevalence differs, between population groups within Australia. Aboriginal children are less likely to have been breast fed than non Aboriginal children. The comparison, indicates that there are deficiencies in the research regarding breast feeding prevalence in both population groups. Many factors affect a woman's decision to breast feed, and the duration of her breast feeding. These factors include, socioeconomic status, age, marital status, educational attainment, occupation and smoking status. These factors are clearly associated with breast feeding in non Aboriginal women. For Aboriginal women, the factors influencing breast feeding are more complex. It is recommended therefore, that it is essential for future research to examine the attitudinal and socialdeterminants of infant feeding practices in Aboriginal women. This is necessary, if educational or interventional strategies are to be effective for this population
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