1,430 research outputs found

    Cavity QED with optically transported atoms

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    Ultracold 87^{87}Rb atoms are delivered into a high-finesse optical micro-cavity using a translating optical lattice trap and detected via the cavity field. The atoms are loaded into an optical lattice from a magneto-optic trap (MOT) and transported 1.5 cm into the cavity. Our cavity satisfies the strong-coupling requirements for a single intracavity atom, thus permitting real-time observation of single atoms transported into the cavity. This transport scheme enables us to vary the number of intracavity atoms from 1 to >>100 corresponding to a maximum atomic cooperativity parameter of 5400, the highest value ever achieved in an atom--cavity system. When many atoms are loaded into the cavity, optical bistability is directly measured in real-time cavity transmission.Comment: 4 figures, 4 page

    Sub-femtosecond absolute timing precision with a 10 GHz hybrid photonic-microwave oscillator

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    We present an optical-electronic approach to generating microwave signals with high spectral purity. By circumventing shot noise and operating near fundamental thermal limits, we demonstrate 10 GHz signals with an absolute timing jitter for a single hybrid oscillator of 420 attoseconds (1Hz - 5 GHz)

    Observation and absolute frequency measurements of the 1S0 - 3P0 optical clock transition in ytterbium

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    We report the direct excitation of the highly forbidden (6s^2) 1S0 - (6s6p) 3P0 optical transition in two odd isotopes of ytterbium. As the excitation laser frequency is scanned, absorption is detected by monitoring the depletion from an atomic cloud at ~70 uK in a magneto-optical trap. The measured frequency in 171Yb (F=1/2) is 518,295,836,593.2 +/- 4.4 kHz. The measured frequency in 173Yb (F=5/2) is 518,294,576,850.0 +/- 4.4 kHz. Measurements are made with a femtosecond-laser frequency comb calibrated by the NIST cesium fountain clock and represent nearly a million-fold reduction in uncertainty. The natural linewidth of these J=0 to J=0 transitions is calculated to be ~10 mHz, making them well-suited to support a new generation of optical atomic clocks based on confinement in an optical lattice.Comment: 4 pages, 3 figure

    Hyperpolarizability and operational magic wavelength in an optical lattice clock

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    Optical clocks benefit from tight atomic confinement enabling extended interrogation times as well as Doppler- and recoil-free operation. However, these benefits come at the cost of frequency shifts that, if not properly controlled, may degrade clock accuracy. Numerous theoretical studies have predicted optical lattice clock frequency shifts that scale nonlinearly with trap depth. To experimentally observe and constrain these shifts in an 171^{171}Yb optical lattice clock, we construct a lattice enhancement cavity that exaggerates the light shifts. We observe an atomic temperature that is proportional to the optical trap depth, fundamentally altering the scaling of trap-induced light shifts and simplifying their parametrization. We identify an "operational" magic wavelength where frequency shifts are insensitive to changes in trap depth. These measurements and scaling analysis constitute an essential systematic characterization for clock operation at the 101810^{-18} level and beyond.Comment: 5 + 2 pages, 3 figures, added supplementa

    Emotion Regulation and Positive Affect in the Context of Salivary Alpha-Amylase Response to Pain in Children with Cancer: Physiology, Self-Report, and Behavior

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    Children with cancer are repeatedly exposed to aversive stimuli including painful procedures. Therefore, emotional regulation techniques may prove useful during such experiences and contribute to pain resilience. This study aimed to determine whether three different emotional regulation strategies (distraction, reappraisal and reassurance) impacted physiological, self- reported and behavioral pain responses in pediatric patients with cancer ages 6 to 18 years (N = 73). The cold pressor task (CPT), an experimental task in which pain is induced by having participants place their hand in cold water, was used to examine pain responses. Patients placed their hand in 7 degree Celsius water for up to 4 minutes. Saliva samples were collected 15 minutes before, immediately after, and then 15 minutes after the CPT. Saliva samples were assayed for alpha amylase, a proxy for sympathetic nervous system activation. Self-reported pain severity was measured upon hand removal. Pain tolerance was assessed by length of time participants kept their hand in the water. Children in the reassurance condition exhibited salivary alpha amylase levels that continued to rise post completion of the CPT as compared to children in the distraction (Beta = -1.68, SE = 0.73, z = -2.30, p = .021, 95% CI [-3.10, -0.25]) and reappraisal (Beta = -1.24, SE = 0.72, z = -1.73, p = .084, 95% CI [-2.65, 0.17]) conditions. However, when self-reported pain and behavior were examined, no differences in pain severity (Wald Chi-squared (2) = 2.47, p = .292), or pain tolerance (Wald Chi-squared (2) = 1.38, p = 0.502) among the emotional regulation strategies were observed. Thus, significant findings were present for physiological markers of distress, but not for self-reported and behavioral measures. These findings suggest that in terms of physiological measures, specific emotional regulation strategies, such as distraction and reappraisal, may be more beneficial in reducing stress responses to painful medical procedures in pediatric patients with cancer as compared to reassurance. These results also demonstrate the importance of examining physiological outcomes in addition to self-report and behavioral outcomes

    Demographic Predictors of Adult Behaviors in the Pediatric Postoperative Environment

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    Over 85% of children experience postoperative pain. If poorly treated, pediatric postoperative pain may lead to various negative health outcomes. Adult behaviors may be associated with child experiences in the postoperative environment. For example, adult behaviors such as distraction, humor, and coping advice divert a child’s attention away from their pain and thus, may significantly reduce child postoperative distress. In contrast, adult behaviors such as empathy, reassurance, and apology direct a child’s attention towards their pain which may increase a child’s overall postoperative distress. Moreover, patient demographic factors, like child ethnicity, may significantly alter the frequency of use of these adult behaviors. Therefore, this study aimed to determine which participant demographic factors are associated with the use of certain adult behaviors in response to child postoperative distress. This study included children ages 2 to 10 years old (N=112) undergoing elective surgery at the Children’s Hospital of Orange County. Participant demographics including ethnicity and race were collected prior to surgery. Nurse, parent, and child postoperative behavioral interactions were video recorded in the Post Anesthesia Care Unit (PACU). From these video recordings, adult behaviors were coded for their frequency of use. Multiple regressions analyses showed that adults were more likely to use humor with Non-Hispanic White children compared to Hispanic children (b = 0.393, p = 0.049). Moreover, fathers were marginally more likely to use empathy, reassurance, and apology with Hispanic children compared to Non-Hispanic White children (b = 0.249, p = 0.05). These results suggest that Hispanic and Non-Hispanic White children may receive different behavioral treatment in response to their postoperative distress. Implications for these findings suggest that child ethnicity may be predictive of different adult PACU behaviors which may illustrate how cultural differences can influence the child postoperative experience

    Observation of the 1S0 - 3P0 clock transition in 27Al+

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    We report for the first time, laser spectroscopy of the 1S0 - 3P0 clock transition in 27Al+. A single aluminum ion and a single beryllium ion are simultaneously confined in a linear Paul trap, coupled by their mutual Coulomb repulsion. This coupling allows the beryllium ion to sympathetically cool the aluminum ion, and also enables transfer of the aluminum's electronic state to the beryllium's hyperfine state, which can be measured with high fidelity. These techniques are applied to a measurement of the clock transition frequency, \nu = 1 121 015 393 207 851(8) Hz. They are also used to measure the lifetime of the metastable clock state, \tau = 20.6 +/- 1.4 s, the ground state 1S0 g-factor, g_S = -0.00079248(14), and the excited state 3P0 g-factor, g_P = -0.00197686(21), in units of the Bohr magneton.Comment: 4 pages, 2 figures; updated author lis

    Revisiting a Common Measure of Child Postoperative Recovery: Development of the Post Hospitalization Behavior Questionnaire for Ambulatory Surgery (PHBQ-AS)

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    Background The Post Hospitalization Behavior Questionnaire (PHBQ) was designed for assessing children\u27s posthospitalization and postoperative new‐onset behavioral changes. However, the psychometric properties of the scale have not been re‐evaluated in the past five decades despite substantial changes in the practice of surgery and anesthesia. In this investigation, we examined the psychometric properties of the PHBQ to potentially increase the efficacy and relevance of the instrument in current perioperative settings. Method This study used principal components analysis, a panel of experts, Cronbach\u27s alpha, and correlations to examine the current subscale structure of the PHBQ and eliminate items to create the Post Hospitalization Behavior Questionnaire for Ambulatory Surgery (PHBQ‐AS). Data from previous investigations (N = 1064, Mage = 5.88) which utilized the PHBQ were combined for the purposes of this paper. Results A principal components analysis revealed that the original subscale structure of the PHBQ could not be replicated. Subsequently, a battery reduction, which utilized principal components analysis and a panel of experts, was used to eliminate the subscale structure of the scale and reduce the number of items from 27 to 11, creating the PHBQ‐AS. The PHBQ‐AS demonstrated good internal consistency reliability and concurrent validity with another measure of children\u27s psychosocial and physical functioning. Conclusion Revising the former subscale structure and reducing the number of items in the PHBQ to create the PHBQ‐AS may provide a means for reducing the burden of postoperative behavioral assessment through decreasing time of administration and eliminating redundancy of items and allow for more accurate measurement of child postoperative behavioral changes

    TESS and CHEOPS discover two warm sub-Neptunes transiting the bright K-dwarf HD 15906

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    We report the discovery of two warm sub-Neptunes transiting the bright (G = 9.5 mag) K-dwarf HD 15906 (TOI 461, TIC 4646810). This star was observed by the Transiting Exoplanet Survey Satellite (TESS) in sectors 4 and 31, revealing two small transiting planets. The inner planet, HD 15906 b, was detected with an unambiguous period but the outer planet, HD 15906 c, showed only two transits separated by ∼ 734 d, leading to 36 possible values of its period. We performed follow-up observations with the CHaracterising ExOPlanet Satellite (CHEOPS) to confirm the true period of HD 15906 c and improve the radius precision of the two planets. From TESS, CHEOPS, and additional ground-based photometry, we find that HD 15906 b has a radius of 2.24 ± 0.08 R⊕ and a period of 10.924709 ± 0.000032 d, whilst HD 15906 c has a radius of 2.93+0.07−0.06 R⊕ and a period of 21.583298+0.000052−0.000055 d. Assuming zero bond albedo and full day-night heat redistribution, the inner and outer planet have equilibrium temperatures of 668 ± 13 K and 532 ± 10 K, respectively. The HD 15906 system has become one of only six multiplanet systems with two warm (≲ 700 K) sub-Neptune sized planets transiting a bright star (G ≤ 10 mag). It is an excellent target for detailed characterization studies to constrain the composition of sub-Neptune planets and test theories of planet formation and evolution
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