3,603 research outputs found
Spaceability in Banach and quasi-Banach sequence spaces
Let be a Banach space. We prove that, for a large class of Banach or
quasi-Banach spaces of -valued sequences, the sets , where is any subset of , and
contain closed infinite-dimensional subspaces of (if
non-empty, of course). This result is applied in several particular cases and
it is also shown that the same technique can be used to improve a result on the
existence of spaces formed by norm-attaining linear operators.Comment: 9 page
Triple seesaw mechanism
On fitting the type II seesaw mechanism into the type I seesaw mechanism, we
obtain a formula to the neutrino masses which get suppressed by high-scale
in its denominator. As a result, light neutrinos are naturally obtained
with new physics at TeV scale. As interesting consequence, the mechanism may be
directly probed at the LHC by directly producing the TeV states intrinsic of
the mechanism. We show that the 3-3-1 model with right-handed neutrinos
realizes naturally such seesaw mechanism.Comment: About 13 pages, no figure
Lineability of the set of bounded linear non-absolutely summing operators
In this note we solve, except for extremely pathological cases, a question
posed by Puglisi and Seoane-Sepulveda on the lineability of the set of bounded
non-absolutely summing linear operators. We also show how the idea of the proof
can be adapted to several related situations.Comment: 7 page
Storage and Retrieval of a Microwave Field in a Spin Ensemble
We report the storage and retrieval of a small microwave field from a
superconducting resonator into collective excitations of a spin ensemble. The
spins are nitrogen-vacancy centers in a diamond crystal. The storage time of
the order of 30 ns is limited by inhomogeneous broadening of the spin ensemble.Comment: 4 pages + supplementary material. Submitted to PR
The Potential Of High-Resolution BAC-FISH In Banana Breeding
Abstract The genetic complexity in the genus Musa has been subject of study in many breeding programs worldwide. Parthenocarpy, female sterility, polyploidy in different cultivars and limited amount of genetic and genomic information make the production of new banana cultivars difficult and time consuming. In addition, it is known that part of the cultivars and related wild species in the genus contain numerous chromosomal rearrangements. In order to produce new cultivars more effectively breeders must better understand the genetic differences of the potential crossing parents for introgression hybridization, but extensive genetic information is lacking. As an alternative to achieve information on genetic collinearity we make use of modern chromosome map technology known as high-resolution fluorescent in situ hybridization (FISH). This article presents the technical aspects and applications of such a technology in Musa species. The technique deals with BAC clone positioning on pachytene chromosomes of Calcutta 4 (Musa acuminata ssp. burmanicoides, A genome group, section Eumusa) and M. velutina (section Rodochlamys). Pollen mother cells digestion with pectolytic enzymes and maceration with acetic acid were optimized for making cell spread preparations appropriate for FISH. As an example of this approach we chose BAC clones that contain markers to known resistance genes and hybridize them for establishing their relative positions on the two species. Technical challenges for adapting existing protocols to the banana cells are presented. We also discuss how this technique can be instrumental for validating collinearity between potential crossing parents and how the method can be helpful in future mapping initiatives, and how this method allows identification of chromosomal rearrangements between related Musa species and cultivar
Microglia and neurons in the hippocampus of migratory sandpipers.
The semipalmated sandpiper Calidris pusilla and the spotted sandpiper Actitis macularia are long- and short-distance migrants, respectively. C. pusilla breeds in the sub-arctic and mid-arctic tundra of Canada and Alaska and winters on the north and east coasts of South America. A. macularia breeds in a broad distribution across most of North America from the treeline to the southern United States. It winters in the southern United States, and Central and South America. The autumn migration route of C. pusilla includes a non-stop flight over the Atlantic Ocean, whereas autumn route of A. macularia is largely over land. Because of this difference in their migratory paths and the visuo-spatial recognition tasks involved, we hypothesized that hippocampal volume and neuronal and glial numbers would differ between these two species. A. macularia did not differ from C. pusilla in the total number of hippocampal neurons, but the species had a larger hippocampal formation and more hippocampal microglia. It remains to be investigated whether these differences indicate interspecies differences or neural specializations associated with different strategies of orientation and navigation
The Small-World Effect for Interferometer Networks
Complex network theory has focused on properties of networks with real-valued
edge weights. However, in signal transfer networks, such as those representing
the transfer of light across an interferometer, complex-valued edge weights are
needed to represent the manipulation of the signal in both magnitude and phase.
These complex-valued edge weights introduce interference into the signal
transfer, but it is unknown how such interference affects network properties
such as small-worldness. To address this gap, we have introduced a small-world
interferometer network model with complex-valued edge weights and generalized
existing network measures to define the interferometric clustering coefficient,
the apparent path length, and the interferometric small-world coefficient.
Using high-performance computing resources, we generated a large set of
small-world interferometers over a wide range of parameters in system size,
nearest-neighbor count, and edge-weight phase and computed their
interferometric network measures. We found that the interferometric small-world
coefficient depends significantly on the amount of phase on complex-valued edge
weights: for small edge-weight phases, constructive interference led to a
higher interferometric small-world coefficient; while larger edge-weight phases
induced destructive interference which led to a lower interferometric
small-world coefficient. Thus, for the small-world interferometer model,
interferometric measures are necessary to capture the effect of interference on
signal transfer. This model is an example of the type of problem that
necessitates interferometric measures, and applies to any wave-based network
including quantum networks
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