7,342 research outputs found
Home nebulizer therapy in children
Drug administration in children is never easy especially in those under five years of age. This is even more so in the case of prophylactic inhalational treatment of asthma in children. The role of home nebulizer therapy is reviewed. Its impact on the need for hospital admission because of acute asthma is discussed.peer-reviewe
Observing the Berry phase in diffusive conductors: Necessary conditions for adiabaticity
In a recent preprint (cond-mat/9803170), van~Langen, Knops, Paasschens and
Beenakker attempt to re-analyze the proposal of Loss, Schoeller and Goldbart
(LSG) [Phys. Rev. B~48, 15218 (1993)] concerning Berry phase effects in the
magnetoconductance of diffusive systems. Van Langen et al. claim that the
adiabatic approximation for the Cooperon previously derived by LSG is not valid
in the adiabatic regime identified by LSG. It is shown that the claim of
van~Langen et al. is not correct, and that, on the contrary, the
magnetoconductance does exhibit the Berry phase effect within the LSG regime of
adiabaticity. The conclusion reached by van~Langen et al. is based on a
misinterpretation of field-induced dephasing effects, which can mask the Berry
phase (and any other phase coherent phenomena) for certain parameter values.Comment: 25 pages, 9 figure
Homology and Robustness of Level and Interlevel Sets
Given a function f: \Xspace \to \Rspace on a topological space, we consider
the preimages of intervals and their homology groups and show how to read the
ranks of these groups from the extended persistence diagram of . In
addition, we quantify the robustness of the homology classes under
perturbations of using well groups, and we show how to read the ranks of
these groups from the same extended persistence diagram. The special case
\Xspace = \Rspace^3 has ramifications in the fields of medical imaging and
scientific visualization
Method and apparatus for measuring distance
The invention employs a continuous wave radar technique and apparatus which can be used as a distance measuring system in the presence of background clutter by utilizing small passive transponders. A first continuous electromagnetic wave signal S sub 1 at a first frequency f sub 1 is transmitted from a first location. A transponder carried by a target object positioned at a second (remote) location receives the transmitted signal, phase-coherently divides the f sub 1 frequency and its phase, and re-transmits the transmitted signal as a second continuous electromagnetic wave signal S sub 2 at a lower frequency f sub 2 which is a subharmonic of f sub 1. The re-transmitted signal is received at the first location where a measurement of the phase difference is made between the signals S sub 1 and S sub 2, such measuremnt being indicative of the distance between the first and second locations
Effects of Nitrogen Fertilization on Monoterpenes of Jack Pine Seedlings and Weight Gain of Jack Pine Budworm (Lepidoptera: Tortricidae)
Nine-month old jack pine (Pinus banksiana) seedlings were grown in a greenhouse under four nitrogen fertilization regimes. Levels of total nitrogen and five monoterpenes in new foliage were measured. Fertilization resulted in four significantly different levels of foliar nitrogen; means ranged from 1.8-4.5 percent dry weight. Contrary to predictions of resource availability theory, seedlings grown under the highest fertilization regime had higher foliar monoterpene levels than seedlings in the other treatments. Newly molted, sixth-instar female jack pine budworm (Choristoneura pinus pinus [Lepidoptera: Tortricidae]) larvae were allowed to feed for four days on new foliage of the seedlings. Larvae that fed on low-nitrogen seedling gained less weight and process more vegetation than did larvae on high- nitrogen seedlings. Larval weight gain was positively related to foliar nitrogen
Doppler radar with multiphase modulation of transmitted and reflected signal
A microwave radar signal is generated and split by a circulator. A phase shifter introduces a series of phase shifts into a first part of the split signal which is then transmitted by antenna. A like number of phase shifts is introduced by the phase shifter into the return signal from the target. The circulator delivers the phase shifted return signal and the leakage signal from the circulator to a mixer which generates an IF signal output at the Doppler frequency. The IF signal is amplified, filtered, counted per unit of time, and the result displayed to provide indications of target sense and range rate. An oscillator controls rate of phase shift in the transmitted and received radar signals and provides a time base for the counter. The phase shift magnitude increases may be continuous and linear or discrete functions of time
Elusiveness of bishomoaromaticity in anionic systems: the bicyclo[3.2.1]octa-3,6-dien-2-yl anion
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The influence of organic anions on the replacement of fixed phosphates at various pH levels.
Thesis (M.S.
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