1,501 research outputs found
Fuzzy Authentication using Rank Distance
Fuzzy authentication allows authentication based on the fuzzy matching of two
objects, for example based on the similarity of two strings in the Hamming
metric, or on the similiarity of two sets in the set difference metric. Aim of
this paper is to show other models and algorithms of secure fuzzy
authentication, which can be performed using the rank metric. A few schemes are
presented which can then be applied in different scenarios and applications.Comment: to appear in Cryptography and Physical Layer Security, Lecture Notes
in Electrical Engineering, Springe
Functional characterization of the human myosin-7a motor domain
Myosin-7a participates in auditory and visual processes. Defects in MYO7A, the gene encoding the myosin-7a heavy chain, are causative for Usher syndrome 1B, the most frequent cause of deaf-blindness in humans. In the present study, we performed a detailed kinetic and functional characterization of the isolated human myosin-7a motor domain to elucidate the details of chemomechanical coupling and the regulation of motor function. A rate-limiting, slow ADP release step causes long lifetimes of strong actin-binding intermediates and results in a high duty ratio. Moreover, our results reveal a Mg2+-sensitive regulatory mechanism tuning the kinetic and mechanical properties of the myosin-7a motor domain. We obtained direct evidence that changes in the concentration of free Mg2+ ions affect the motor properties of human myosin-7a using an in vitro motility assay system. Our results suggest that in a cellular environment, compartment-specific fluctuations in free Mg2+ ions can mediate the conditional switching of myosin-7a between cargo moving and tension bearing modes
Single-crosslink microscopy in a biopolymer network dissects local elasticity from molecular fluctuations
Polymer networks are fundamental from cellular biology to plastics technology but their intrinsic inhomogeneity is masked by the usual ensemble-averaged measurements. Here, we construct direct maps of crosslinks-symbolic depiction of spatially-distributed elements highlighting their physical features and the relationships between them-in an actin network. We selectively label crosslinks with fluorescent markers, track their thermal fluctuations, and characterize the local elasticity and cross-correlations between crosslinks. Such maps display massive heterogeneity, reveal abundant anticorrelations, and may contribute to address how local responses scale up to produce macroscopic elasticity. Single-crosslink microscopy offers a general, microscopic framework to better understand crosslinked molecular networks in undeformed or strained states
Adaptive Evolution of the Myo6 Gene in Old World Fruit Bats (Family: Pteropodidae)
PMCID: PMC3631194This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
β-Actin and γ-Actin Are Each Dispensable for Auditory Hair Cell Development But Required for Stereocilia Maintenance
Hair cell stereocilia structure depends on actin filaments composed of cytoplasmic β-actin and Îł-actin isoforms. Mutations in either gene can lead to progressive hearing loss in humans. Since β-actin and Îł-actin isoforms are 99% identical at the protein level, it is unclear whether each isoform has distinct cellular roles. Here, we compared the functions of β-actin and Îł-actin in stereocilia formation and maintenance by generating mice conditionally knocked out for Actb or Actg1 in hair cells. We found that, although cytoplasmic actin is necessary, neither β-actin nor Îł-actin is required for normal stereocilia development or auditory function in young animals. However, aging mice with β-actinâ or Îł-actinâdeficient hair cells develop different patterns of progressive hearing loss and distinct pathogenic changes in stereocilia morphology, despite colocalization of the actin isoforms. These results demonstrate overlapping developmental roles but unique post-developmental functions for β-actin and Îł-actin in maintaining hair cell stereocilia
Error-Prone ZW Pairing and No Evidence for Meiotic Sex Chromosome Inactivation in the Chicken Germ Line
In the male mouse the X and Y chromosomes pair and recombine within the small pseudoautosomal region. Genes located on the unsynapsed segments of the X and Y are transcriptionally silenced at pachytene by Meiotic Sex Chromosome Inactivation (MSCI). The degree to which MSCI is conserved in other vertebrates is currently unclear. In the female chicken the ZW bivalent is thought to undergo a transient phase of full synapsis at pachytene, starting from the homologous ends and spreading through the heterologous regions. It has been proposed that the repair of the ZW DNA double-strand breaks (DSBs) is postponed until diplotene and that the ZW bivalent is subject to MSCI, which is independent of its synaptic status. Here we present a distinct model of meiotic pairing and silencing of the ZW pair during chicken oogenesis. We show that, in most oocytes, DNA DSB foci on the ZW are resolved by the end of pachytene and that the ZW desynapses in broad synchrony with the autosomes. We unexpectedly find that ZW pairing is highly error prone, with many oocytes failing to engage in ZW synapsis and crossover formation. Oocytes with unsynapsed Z and W chromosomes nevertheless progress to the diplotene stage, suggesting that a checkpoint does not operate during pachytene in the chicken germ line. Using a combination of epigenetic profiling and RNAâFISH analysis, we find no evidence for MSCI, associated with neither the asynaptic ZW, as described in mammals, nor the synaptic ZW. The lack of conservation of MSCI in the chicken reopens the debate about the evolution of MSCI and its driving forces
Early feeding patterns among Mexican babies: findings from the 2012 National Health and Nutrition Survey and implications for health and obesity prevention
Compressed representation of a partially defined integer function over multiple arguments
In OLAP (OnLine Analitical Processing) data are analysed in an n-dimensional cube. The cube may be represented as a partially defined function over n arguments. Considering that often the function is not defined everywhere, we ask: is there a known way of representing the function or the points in which it is defined, in a more compact manner than the trivial one
Azimuthal anisotropy of charged particles at high transverse momenta in PbPb collisions at sqrt(s[NN]) = 2.76 TeV
The azimuthal anisotropy of charged particles in PbPb collisions at
nucleon-nucleon center-of-mass energy of 2.76 TeV is measured with the CMS
detector at the LHC over an extended transverse momentum (pt) range up to
approximately 60 GeV. The data cover both the low-pt region associated with
hydrodynamic flow phenomena and the high-pt region where the anisotropies may
reflect the path-length dependence of parton energy loss in the created medium.
The anisotropy parameter (v2) of the particles is extracted by correlating
charged tracks with respect to the event-plane reconstructed by using the
energy deposited in forward-angle calorimeters. For the six bins of collision
centrality studied, spanning the range of 0-60% most-central events, the
observed v2 values are found to first increase with pt, reaching a maximum
around pt = 3 GeV, and then to gradually decrease to almost zero, with the
decline persisting up to at least pt = 40 GeV over the full centrality range
measured.Comment: Replaced with published version. Added journal reference and DO
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