6,018 research outputs found
Factorization properties of genus-two bosonic and fermionic string partition functions
The genus-two bosonic and fermionic string partition functions factorize, in the separating pinching limit, into genus-one partition functions after integrating out the supermoduli with super-Beltrami support on the puncture points in the fermionic and heterotic case
Reconstruction of protein structures from a vectorial representation
We show that the contact map of the native structure of globular proteins can
be reconstructed starting from the sole knowledge of the contact map's
principal eigenvector, and present an exact algorithm for this purpose. Our
algorithm yields a unique contact map for all 221 globular structures of
PDBselect25 of length . We also show that the reconstructed contact
maps allow in turn for the accurate reconstruction of the three-dimensional
structure. These results indicate that the reduced vectorial representation
provided by the principal eigenvector of the contact map is equivalent to the
protein structure itself. This representation is expected to provide a useful
tool in bioinformatics algorithms for protein structure comparison and
alignment, as well as a promising intermediate step towards protein structure
prediction.Comment: 4 pages, 1 figur
A Wave Function Describing Superfluidity in a Perfect Crystal
We propose a many-body wave function that exhibits both diagonal and
off-diagonal long-range order. Incorporating short-range correlations due to
interatomic repulsion, this wave function is shown to allow condensation of
zero-point lattice vibrations and phase rigidity. In the presence of an
external velocity field, such a perfect crystal will develop non-classical
rotational inertia, exhibiting the supersolid behavior. In a sample calculation
we show that the superfluid fraction in this state can be as large as of order
0.01 in a reasonable range of microscopic parameters. The relevance to the
recent experimental evidence of a supersolid state by Chan and Kim is
discussed.Comment: final version to be published in Journal of Statistical Mechanics:
Theory and Experimen
Janus and Multifaced Supersymmetric Theories
We investigate the various properties Janus supersymmetric Yang-Mills
theories. A novel vacuum structure is found and BPS monopoles and dyons are
studied. Less supersymmetric Janus theories found before are derived by a
simpler method. In addition, we find the supersymmetric theories when the
coupling constant depends on two and three spatial coordinates.Comment: 20 pages, no figures, typos, equations corrected. Additional comment
Nedd4-2 haploinsufficiency causes hyperactivity and increased sensitivity to inflammatory stimuli
Nedd4-2 (NEDD4L in humans) is a ubiquitin protein ligase best known for its role in regulating ion channel internalization and turnover. Nedd4-2 deletion in mice causes perinatal lethality associated with increased epithelial sodium channel (ENaC) expression in lung and kidney. Abundant data suggest that Nedd4-2 plays a role in neuronal functions and may be linked to epilepsy and dyslexia in humans. We used a mouse model of Nedd4-2 haploinsufficiency to investigate whether an alteration in Nedd4-2 levels of expression affects general nervous system functions. We found that Nedd4-2 heterozygous mice are hyperactive, have increased basal synaptic transmission and have enhanced sensitivity to inflammatory pain. Thus, Nedd4-2 heterozygous mice provide a new genetic model to study inflammatory pain. These data also suggest that in human, SNPs affecting NEDD4L levels may be involved in the development of neuropsychological deficits and peripheral neuropathies and may help unveil the genetic basis of comorbidities
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