1,930 research outputs found
Phase and group velocity tracing analysis of projected wave packet motion along oblique radar beams ? qualitative analysis of QP echoes
International audienceThe wave packets of atmospheric gravity waves were numerically generated, with a given characteristic wave period, horizontal wave length and projection mean wind along the horizontal wave vector. Their projection phase and group velocities along the oblique radar beam (vpr and vgr), with different zenith angle ? and azimuth angle ?, were analyzed by the method of phase- and group-velocity tracing. The results were consistent with the theoretical calculations derived by the dispersion relation, reconfirming the accuracy of the method of analysis. The RTI plot of the numerical wave packets were similar to the striation patterns of the QP echoes from the FAI irregularity region. We propose that the striation range rate of the QP echo is equal to the radial phase velocity vpr, and the slope of the energy line across the neighboring striations is equal to the radial group velocity vgr of the wave packet; the horizontal distance between two neighboring striations is equal to the characteristic wave period ?. Then, one can inversely calculate all the properties of the gravity wave responsible for the appearance of the QP echoes. We found that the possibility of some QP echoes being generated by the gravity waves originated from lower altitudes cannot be ruled out
New hydrogen-like potentials
Using the modified factorization method introduced by Mielnik, we construct a
new class of radial potentials whose spectrum for l=0 coincides exactly with
that of the hydrogen atom. A limiting case of our family coincides with the
potentials previously derived by Abraham and MosesComment: 6 pages, latex, 2 Postscript figure
Interpretation of knockout experiments: the congenic footprint
In gene targeting experiments, the importance of genetic background is now widely appreciated, and knockout alleles are routinely backcrossed onto a standard inbred background. This produces a congenic strain with a substantial segment of embryonic stem (ES)-cell-derived chromosome still flanking the knockout allele, a phenomenon often neglected in knockout studies. In cholecystokynin 2 (Cckbr) knockout mice backcrossed with C57BL/6, we have found a clear ‘congenic footprint’ of expression differences in at least 10 genes across 40 Mb sequence flanking the Cckbr locus, each of which is potentially responsible for aspects of the ‘knockout’ phenotype. The expression differences are overwhelmingly in the knockout-low direction, which may point to a general phenomenon of background dependence. This finding emphasizes the need for caution in using gene knockouts to attribute phenotypic effects to genes. This is especially the case when the gene is of unknown function or the phenotype is unexpected, and is a particular concern for large-scale knockout and phenotypic screening programmes. However, the impact of genetic background should not be simply viewed as a potential confound, but as a unique opportunity to study the broader responses of a system to a specific (genetic) perturbation
Nurses\u27 Alumnae Association Bulletin - Volume 2 Number 3
The Jefferson Nurse
Letter from the President
Delegates to Biennial Convention
Attention
Blood Transfusion - Plasma Unit
Life in the Army Nurse Corps
Secretary\u27s Report
Elected to New Office
1892-1942
Progress or Alumnae Association 1892-1942
Report of the School of Nursing
Staff News
Please Change My Address
Air Cooled
Red Cross Report
Fingerprinting
Graduates in the U.S. Army and Navy
Degrees Received
Promotions
Jubilee Report
Engagements
Marriages
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New Positions - 1941-1942
New Positions on the Nursing Staff of the Hospita
Taking advantage from phenotype variability in a local animal genetic resource: identification of genomic regions associated with the hairless phenotype in Casertana pigs
Casertana is an endangered autochthonous pig breed (raised in south-central Italy) that is considered to be the descendant of the influential Neapolitan pig population that was used to improve British breeds in the 19th century. Casertana pigs are characterized by a typical, almost complete, hairless phenotype, even though a few Casertana pigs are normal haired. In this work, using Illumina PorcineSNP60 BeadChip data, we carried out a genome-wide association study and an FST analysis with this breed by comparing animals showing the classical hairless phenotype (n\ua0=\ua081) versus pigs classified as haired (n\ua0=\ua015). Combining the results obtained with the two approaches, we identified two significant regions: one on porcine chromosome (SSC) 7 and one on SSC15. The SSC7 region contains the forkhead box N3 (FOXN3) gene, the most plausible candidate gene of this region, considering that mutations in another gene of the same family (forkhead box N1; Foxn1 or FOXN1) are responsible for the nude locus in rodents and alopecia in humans. Another potential candidate gene, rho guanine nucleotide exchange factor 10 (ARHGEF10), is located in the SSC15 region. FOXN3 and ARHGEF10 have been detected as differentially expressed in androgenetic and senescent alopecia respectively. This study on an autochthonous pig breed contributes to shed some light on novel genes potentially involved in hair development and growth and demonstrates that local animal breeds can be valuable genetic resources for disclosing genetic factors affecting unique traits, taking advantage of phenotype variability segregating in small populations
Geometric Phases and Mielnik's Evolution Loops
The cyclic evolutions and associated geometric phases induced by
time-independent Hamiltonians are studied for the case when the evolution
operator becomes the identity (those processes are called {\it evolution
loops}). We make a detailed treatment of systems having equally-spaced energy
levels. Special emphasis is made on the potentials which have the same spectrum
as the harmonic oscillator potential (the generalized oscillator potentials)
and on their recently found coherent states.Comment: 11 pages, harvmac, 2 figures available upon request; CINVESTAV-FIS
GFMR 11/9
DRAFT 03
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