2,485 research outputs found

    Frequency stabilization of an external-cavity diode laser

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    Using a hybrid optical/electronic technique, an external-cavity diode laser was frequency stabilized with respect to the sub-Doppler spectrum of cesium vapor. Laser linewidths of 65 kHz and frequency stabilities of ±10 kHz were obtained

    Shot Noise Suppression in Avalanche Photodiodes

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    We identify a new shot noise suppression mechanism in a thin (~100 nm) heterostructure avalanche photodiode. In the low-gain regime the shot noise is suppressed due to temporal correlations within amplified current pulses. We demonstrate in a Monte Carlo simulation that the effective excess noise factors can be <1, and reconcile the apparent conflict between theory and experiments. This shot noise suppression mechanism is independent of known mechanisms such as Coulomb interaction, or reflection at heterojunction interfaces.Comment: Phys. Rev. Lett., accepted for publicatio

    Comparison of supplemented free choice corn silage rations with other forage rations for wintering dairy heifers

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    This publication is a report on Department of Dairy Husbandry research project 55, Diet and Growth--P. [2].Digitized 2007 AES.Includes bibliographical references (page 8)

    Association of Over-The-Counter Pharmaceutical Sales with Influenza-Like-Illnesses to Patient Volume in an Urgent Care Setting

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    We studied the association between OTC pharmaceutical sales and volume of patients with influenza-like-illnesses (ILI) at an urgent care center over one year. OTC pharmaceutical sales explain 36% of the variance in the patient volume, and each standard deviation increase is associated with 4.7 more patient visits to the urgent care center (p<0.0001). Cross-correlation function analysis demonstrated that OTC pharmaceutical sales are significantly associated with patient volume during non-flu season (p<0.0001), but only the sales of cough and cold (p<0.0001) and thermometer (p<0.0001) categories were significant during flu season with a lag of two and one days, respectively. Our study is the first study to demonstrate and measure the relationship between OTC pharmaceutical sales and urgent care center patient volume, and presents strong evidence that OTC sales predict urgent care center patient volume year round. © 2013 Liu et al

    What’s Sex (Composition) Got to Do with It? The Importance of Sex Composition of Gangs for Female and Male Members’ Offending and Victimization

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    Sex composition of groups has been theorized in organizational sociology and found in prior work to structure female and male members’ behaviors and experiences. Peer group and gang literature similarly finds that the sex gap in offending varies across groups of differing sex ratios. Drawing on this and other research linking gang membership, offending, and victimization, we examine whether sex composition of gangs is linked to sex differences in offending in this sample, further assess whether sex composition similarly structures females’ and males’ victimization experiences, and if so, why. Self-report data from gang members in a multi-site, longitudinal study of 3,820 youths are employed. Results support previous findings about variations in member delinquency by both sex and sex composition of the gang and also indicate parallel variations in members’ victimization. These results are further considered within the context of facilitating effects such as gender dynamics, gang characteristics, and normative orientation

    Rise in carriage of group W meningococci in university students in United Kingdom

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    MenACWY conjugate vaccination was recently introduced in the UK for adolescents and 24 young adults to reduce disease due to Neisseria meningitidis group W (MenW). We 25 conducted a cross-sectional carriage study in first year university students. Despite 71% 26 MenACWY vaccine coverage, carriage of MenW, but not MenY, rose significantly in 27 students
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