12,811 research outputs found

    Quantum Seismology

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    We propose a quantum mechanical method of detecting weak vibrational disturbances inspired by the protocol of entanglement farming. We consider a setup where pairs of atoms in their ground state are successively sent through an optical cavity. It is known that in this way it is possible to drive that cavity toward a stable fixed-point state. Here we study how that fixed-point state depends on the time interval between pairs of atoms and on the distance between the cavity's mirrors. Taking advantage of an extremely precise resonance effect, we find that there are special values of these parameters where the fixed-point state is highly sensitive to perturbations, even harmonic vibrations with frequencies several orders of magnitude below the cavity's natural frequency. We propose that this sensitivity may be useful for high precision metrology.Comment: 10 pages, 5 figures. RevTeX 4.

    Milk whey protein concentration and mRNA associated with β-lactoglobulin phenotype

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    Two common genetic variants of β-lactoglobulin (β-lg), A and B, exist as co- dominant alleles in dairy cattle (Aschaffenburg, 1968). Numerous studies have shown that cows homozygous for β-lg A have more β-lg and less α-lactalbumin (α-la) and casein in their milk than cows expressing only the B variant of β-lg (Ng-Kwai-Hang et al. 1987; Graml et al. 1989; Hill, 1993; Hill et al. 1995, 1997). These differences have a significant impact on the processing characteristics of the milk. For instance, the moisture-adjusted yield of Cheddar cheese is up to 10% higher using milk from cows of the β-lg BB phenotype compared with milk from cows expressing only the A variant (Hill et al. 1997). All these studies, however, describe compositional differences associated with β-lg phenotype in established lactation only. No information is available on the first few weeks of lactation, when there are marked changes in the concentrations of β-lg and α-la (Pérez et al. 1990)

    Investigating the medium range order in amorphous Ta<sub>2</sub>O<sub>5</sub> coatings

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    Ion-beam sputtered amorphous heavy metal oxides, such as Ta2O5, are widely used as the high refractive index layer of highly reflective dielectric coatings. Such coatings are used in the ground based Laser Interferometer Gravitational-wave Observatory (LIGO), in which mechanical loss, directly related to Brownian thermal noise, from the coatings forms an important limit to the sensitivity of the LIGO detector. It has previously been shown that heat-treatment and TiO2 doping of amorphous Ta2O5 coatings causes significant changes to the levels of mechanical loss measured and is thought to result from changes in the atomic structure. This work aims to find ways to reduce the levels of mechanical loss in the coatings by understanding the atomic structure properties that are responsible for it, and thus helping to increase the LIGO detector sensitivity. Using a combination of Reduced Density Functions (RDFs) from electron diffraction and Fluctuation Electron Microscopy (FEM), we probe the medium range order (in the 2-3 nm range) of these amorphous coatings

    Thermally Activated Magnetization and Resistance Decay during Near Ambient Temperature Aging of Co Nanoflakes in a Confining Semi-metallic Environment

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    We report the observation of magnetic and resistive aging in a self assembled nanoparticle system produced in a multilayer Co/Sb sandwich. The aging decays are characterized by an initial slow decay followed by a more rapid decay in both the magnetization and resistance. The decays are large accounting for almost 70% of the magnetization and almost 40% of the resistance for samples deposited at 35 oC^oC. For samples deposited at 50 oC^oC the magnetization decay accounts for 50\sim 50% of the magnetization and 50% of the resistance. During the more rapid part of the decay, the concavity of the slope of the decay changes sign and this inflection point can be used to provide a characteristic time. The characteristic time is strongly and systematically temperature dependent, ranging from 1\sim1x102s10^2 s at 400K to 3\sim3x105s10^5 s at 320K in samples deposited at 35oC35 ^oC. Samples deposited at 50 oC^oC displayed a 7-8 fold increase in the characteristic time (compared to the 35oC35 ^oC samples) for a given aging temperature, indicating that this timescale may be tunable. Both the temperature scale and time scales are in potentially useful regimes. Pre-Aging, Scanning Tunneling Microscopy (STM) reveals that the Co forms in nanoscale flakes. During aging the nanoflakes melt and migrate into each other in an anisotropic fashion forming elongated Co nanowires. This aging behavior occurs within a confined environment of the enveloping Sb layers. The relationship between the characteristic time and aging temperature fits an Arrhenius law indicating activated dynamics

    Trends in Pediatric Patient-Ventilator Asynchrony During Invasive Mechanical Ventilation

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    OBJECTIVES: To explore the level and time course of patient-ventilator asynchrony in mechanically ventilated children and the effects on duration of mechanical ventilation, PICU stay, and Comfort Behavior Score as indicator for patient comfort.DESIGN: Secondary analysis of physiology data from mechanically ventilated children.SETTING: Mixed medical-surgical tertiary PICU in a university hospital.PATIENTS: Mechanically ventilated children 0-18 years old were eligible for inclusion. Excluded were patients who were unable to initiate and maintain spontaneous breathing from any cause.MEASUREMENTS AND MAIN RESULTS: Twenty-nine patients were studied with a total duration of 109 days. Twenty-two study days (20%) were excluded because patients were on neuromuscular blockade or high-frequency oscillatory ventilation, yielding 87 days (80%) for analysis. Patient-ventilator asynchrony was detected through analysis of daily recorded ventilator airway pressure, flow, and volume versus time scalars. Approximately one of every three breaths was asynchronous. The percentage of asynchronous breaths significantly increased over time, with the highest prevalence on the day of extubation. There was no correlation with the Comfort Behavior score. The percentage of asynchronous breaths during the first 24 hours was inversely correlated with the duration of mechanical ventilation. Patients with severe patient-ventilator asynchrony (asynchrony index &gt; 10% or &gt; 75th percentile of the calculated asynchrony index) did not have a prolonged duration of ventilation.CONCLUSIONS: The level of patient-ventilator asynchrony increased over time was not related to patient discomfort and inversely related to the duration of mechanical ventilation.</p

    Hepatic Arterial Therapy with Drug-Eluting Beads in the Management of Metastatic Bronchogenic Carcinoma to the Liver: A Multi-Institutional Registry

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    Introduction. There has been limited information reported on the use of hepatic arterial therapy in liver dominant hepatic metastases arising from lung cancer. The aim of this study was to evaluate the safety and efficacy of hepatic arterial therapy in the treatment of liver dominant hepatic metastases arising from lung cancer. Methods. Thirteen patients underwent a total of 30 treatment sessions with Drug-Eluting Beads. Eight of the thirteen received only doxorubicin DEB (17 of the total treatments), and four patients received Irinotecan DEB (7 of the total treatments). Results. The planned preprocedural dosage was a median of 75 mg (range 19–200), with total hepatic dose exposure being a median of 150 mg (range 0–458), with a technical success rate of 97% in all 29 treatments. There were 4 adverse events related to treatment, but no evidence of hepatic insufficiency. Overall 6-month and 12-month response rates were 50%. After a median followup of 24 months, the median overall survival in this cohort was 14 months (range 7–48 months). Conclusion. Drug-eluting beads loaded with doxorubicin (DEBDOX) or irinotecan (DEBIRI) can be safely and effectively used in treatment of patients with liver predominant metastatic disease from lung cancer
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