734 research outputs found
Comparison of Howland and General Impedance Converter (GIC) circuit based current sources for bio-impedance measurements
The current source is a key component in bio-impedance measurement systems. The accuracy of the current source can be measured in terms of its output impedance together with other parameters, with certain applications demanding extremely high output impedance. This paper presents an investigation and comparison of different current source designs based on the Enhanced Howland circuit combined with a General Impedance Converter (GIC) circuit using both ideal and non-ideal operational amplifiers. Under differing load conditions two different settings of the GIC are evaluated and the results are compared to show its performance settings. Whilst the study has shown that over a wide bandwidth (i.e. 100Hz-100MHz) the output impedance is limited, operation over a more limited range offers output impedance in the Giga-ohm range, which can be considered as being infinite
Product rule for gauge invariant Weyl symbols and its application to the semiclassical description of guiding center motion
We derive a product rule for gauge invariant Weyl symbols which provides a
generalization of the well-known Moyal formula to the case of non-vanishing
electromagnetic fields. Applying our result to the guiding center problem we
expand the guiding center Hamiltonian into an asymptotic power series with
respect to both Planck's constant and an adiabaticity parameter already
present in the classical theory. This expansion is used to determine the
influence of quantum mechanical effects on guiding center motion.Comment: 24 pages, RevTeX, no figures; shortened version will be published in
J.Phys.
The large-scale energetic ion layer in the high latitude Jovian magnetosphere as revealed by Ulysses/HI-SCALE cross-field intensity-gradient measurements
Ulysses investigated the high latitude Jovian magnetosphere for a second time
after Pioneer 11 mission and gave us the opportunity to search the structure
and the dynamics of this giant magnetosphere above the magnetodisc.
Kivelson(1976) and Kennel & Coroniti(1979) reported that Pioneer 11 observed
energetic particle intensities at high latitudes at the same level with those
measured in the plasma sheet and inferred that they were not consistent with
the magnetodisc model. Ulysses observations supported the idea about a
large-scale layer of energetic ions and electrons in the outer high latitude
Jovian magnetosphere (Cowley et al.1996; Anagnostopoulos et al. 2001). This
study perform a number of further tests for the existence of the large scale
layer of energetic ions in the outer high latitude Jovian magnetosphere by
studying appropriate cross-B field anisotropies in order to monitor the ion
northward/southward intensity gradients. In particular, we examined
Ulysses/HI-SCALE observations of energetic ions with large gyro-radius
(0.5-1.6MeV protons and >2.5MeV heavy(Z>5) ions) in order to compare instant
intensity changes with remote sensing intensity gradients. Our analysis
confirms the existence of an energetic particle layer in the north hemisphere,
during the inbound trajectory of Ulysses traveling at moderate latitudes, and
in the south high-latitude duskside magnetosphere, during the outbound segment
of the spacecraft trajectory. Our Ulysses/HI-SCALE data analysis also provides
evidence for the detection of an energetic proton magnetopause boundary layer
during the outbound trajectory of the spacecraft. During Ulysses flyby of
Jupiter the almost permanent appearance of alternative northward and southward
intensity gradients suggests that the high latitude layer appeared to be a
third major area of energetic particles, which coexisted with the radiation
belts and the magnetodisc.Comment: 37 pages, 11 figures, 1 tabl
Expression of Interest: The Atmospheric Neutrino Neutron Interaction Experiment (ANNIE)
Submitted for the January 2014 Fermilab Physics Advisory Committee meetingSubmitted for the January 2014 Fermilab Physics Advisory Committee meetingSubmitted for the January 2014 Fermilab Physics Advisory Committee meetingSubmitted for the January 2014 Fermilab Physics Advisory Committee meetingNeutron tagging in Gadolinium-doped water may play a significant role in reducing backgrounds from atmospheric neutrinos in next generation proton-decay searches using megaton-scale Water Cherenkov detectors. Similar techniques might also be useful in the detection of supernova neutrinos. Accurate determination of neutron tagging efficiencies will require a detailed understanding of the number of neutrons produced by neutrino interactions in water as a function of momentum transferred. We propose the Atmospheric Neutrino Neutron Interaction Experiment (ANNIE), designed to measure the neutron yield of atmospheric neutrino interactions in gadolinium-doped water. An innovative aspect of the ANNIE design is the use of precision timing to localize interaction vertices in the small fiducial volume of the detector. We propose to achieve this by using early production of LAPPDs (Large Area Picosecond Photodetectors). This experiment will be a first application of these devices demonstrating their feasibility for Water Cherenkov neutrino detectors
Expression of Interest: The Atmospheric Neutrino Neutron Interaction Experiment (ANNIE)
Neutron tagging in Gadolinium-doped water may play a significant role in
reducing backgrounds from atmospheric neutrinos in next generation proton-decay
searches using megaton-scale Water Cherenkov detectors. Similar techniques
might also be useful in the detection of supernova neutrinos. Accurate
determination of neutron tagging efficiencies will require a detailed
understanding of the number of neutrons produced by neutrino interactions in
water as a function of momentum transferred. We propose the Atmospheric
Neutrino Neutron Interaction Experiment (ANNIE), designed to measure the
neutron yield of atmospheric neutrino interactions in gadolinium-doped water.
An innovative aspect of the ANNIE design is the use of precision timing to
localize interaction vertices in the small fiducial volume of the detector. We
propose to achieve this by using early production of LAPPDs (Large Area
Picosecond Photodetectors). This experiment will be a first application of
these devices demonstrating their feasibility for Water Cherenkov neutrino
detectors.Comment: Submitted for the January 2014 Fermilab Physics Advisory Committee
meetin
Bacteremia After Prophylaxis II
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141639/1/jper0371.pd
"Author! Author!" : Shakespeare and biography
Original article can be found at: http://www.informaworld.com/smpp/title~content=t714579626~db=all Copyright Informa / Taylor & Francis Group. DOI: 10.1080/17450910902764454Since 1996, not a year has passed without the publication of at least one Shakespeare biography. Yet for many years the place of the author in the practice of understanding literary works has been problematized, and even on occasions eliminated. Criticism reads the âworksâ, and may or may not refer to an author whose âlifeâ contributed to their meaning. Biography seeks the author in the works, the personality that precedes the works and gives them their characteristic shape and meaning. But the form of literary biography addresses the unusual kind of âlifeâ that puts itself into âworksâ, and this is particularly challenging where the âworksâ predominate massively over the salient facts of the âlifeâ. This essay surveys the current terrain of Shakespeare biography, and considers the key questions raised by the medium: can we know anything of Shakespeare's âpersonalityâ from the facts of his life and the survival of his works? What is the status of the kind of speculation that inevitably plays a part in biographical reconstruction? Are biographers in the end telling us as much about themselves as they tell us about Shakespeare?Peer reviewe
Adjusting plasma ferritin concentrations to remove the effects of subclinical inflammation in the assessment of iron deficiency: a meta-analysis
Background: The World Health Organization recommends serum ferritin concentrations as the best indicator of iron deficiency (ID). Unfortunately, ferritin increases with infections; hence, the prevalence of ID is underestimated. Objective: The objective was to estimate the increase in ferritin in 32 studies of apparently healthy persons by using 2 acute-phase proteins (APPs). C-reactive protein (CRP) and alpha(1)-acid glycoprotein (AGP), individually and in combination, and to calculate factors to remove the influence of inflammation from ferritin concentrations. Design: We estimated the increase in ferritin associated with inflammation (ie, CRP >5 mg/L and/or AGP >1 g/L). The 32 studies comprised infants (5 studies), children (7 studies), men (4 studies), and women (16 studies) (n = 8796 subjects). In 2-group analyses (either CRP or AGP), we compared the ratios of log ferritin with or without inflammation in 30 studies. In addition, in 22 studies, the data allowed a comparison of ratios of log ferritin between 4 subgroups: reference (no elevated APP), incubation (elevated CRP only), early convalescence (both APP and CRP elevated), and late convalescence (elevated AGP only). Results: In the 2-group analysis, inflammation increased ferritin by 49.6% (CRP) or 38.2% (AGP; both P <0.001). Elevated AGP was more common than CRP in young persons than in adults. In the 4-group analysis, ferritin was 30%, 90%, and 36% (all P < 0.001) higher in the incubation, early convalescence, and late convalescence subgroups, respectively, with corresponding correction factors of 0.77, 0.53, and 0.75. Overall, inflammation increased ferritin by approximate to 30% and was associated with a 14% (CI: 7%, 21%) underestimation of ID. Conclusions: Measures of both APP and CRP are needed to estimate the full effect of inflammation and can be used to correct ferritin concentrations. Few differences were observed between age and sex subgroups. Am J Clin Nutr 2010;92:546-55
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