Quantum cryptography with a predetermined key, using continuous variable Einstein-Podolsky-Rosen correlations

Correlations of the type discussed by EPR in their original 1935 paradox for continuous variables exist for the quadrature phase amplitudes of two spatially separated fields. These correlations were experimentally reported in 1992. We propose to use such EPR beams in quantum cryptography, to transmit with high efficiency messages in such a way that the receiver and sender may later determine whether eavesdropping has occurred. The merit of the new proposal is in the possibility of transmitting a reasonably secure yet predetermined key. This would allow relay of a cryptographic key over long distances in the presence of lossy channels.Comment: 11 pages,3 figures, changes are important,presented at QELS(May,2000) San Francisc

In vivo substrates of the lens molecular chaperones αA-crystallin and αB-crystallin

αA-crystallin and αB-crystallin are members of the small heat shock protein family and function as molecular chaperones and major lens structural proteins. Although numerous studies have examined their chaperone-like activities in vitro, little is known about the proteins they protect in vivo. To elucidate the relationships between chaperone function, substrate binding, and human cataract formation, we used proteomic and mass spectrometric methods to analyze the effect of mutations associated with hereditary human cataract formation on protein abundance in αA-R49C and αB-R120G knock-in mutant lenses. Compared with age-matched wild type lenses, 2-day-old αA-R49C heterozygous lenses demonstrated the following: increased crosslinking (15-fold) and degradation (2.6-fold) of αA-crystallin; increased association between αA-crystallin and filensin, actin, or creatine kinase B; increased acidification of βB1-crystallin; increased levels of grifin; and an association between βA3/A1-crystallin and αA-crystallin. Homozygous αA-R49C mutant lenses exhibited increased associations between αA-crystallin and βB3-, βA4-, βA2-crystallins, and grifin, whereas levels of βB1-crystallin, gelsolin, and calpain 3 decreased. The amount of degraded glutamate dehydrogenase, α-enolase, and cytochrome c increased more than 50-fold in homozygous αA-R49C mutant lenses. In αB-R120G mouse lenses, our analyses identified decreased abundance of phosphoglycerate mutase, several β- and γ-crystallins, and degradation of αA- and αB-crystallin early in cataract development. Changes in the abundance of hemoglobin and histones with the loss of normal α-crystallin chaperone function suggest that these proteins also play important roles in the biochemical mechanisms of hereditary cataracts. Together, these studies offer a novel insight into the putative in vivo substrates of αA- and αB-crystallin

Type IV pili are a critical virulence factor in clinical isolates of Paenibacillus thiaminolyticus

Hydrocephalus, the leading indication for childhood neurosurgery worldwide, is particularly prevalent in low- and middle-income countries. Hydrocephalus preceded by an infection, or postinfectious hydrocephalus, accounts for up to 60% of hydrocephalus in these areas. Since many children with hydrocephalus suffer poor long-term outcomes despite surgical intervention, prevention of hydrocephalus remains paramount. Our previous studies implicated a novel bacterial pathogen, Paenibacillus thiaminolyticus, as a causal agent of neonatal sepsis and postinfectious hydrocephalus in Uganda. Here, we report the isolation of thre

The Haemophilus influenzae HMW1C protein is a glycosyltransferase that transfers hexose residues to asparagine sites in the HMW1 adhesin

The Haemophilus influenzae HMW1 adhesin is a high-molecular weight protein that is secreted by the bacterial two-partner secretion pathway and mediates adherence to respiratory epithelium, an essential early step in the pathogenesis of H. influenzae disease. In recent work, we discovered that HMW1 is a glycoprotein and undergoes N-linked glycosylation at multiple asparagine residues with simple hexose units rather than N-acetylated hexose units, revealing an unusual N-glycosidic linkage and suggesting a new glycosyltransferase activity. Glycosylation protects HMW1 against premature degradation during the process of secretion and facilitates HMW1 tethering to the bacterial surface, a prerequisite for HMW1-mediated adherence. In the current study, we establish that the enzyme responsible for glycosylation of HMW1 is a protein called HMW1C, which is encoded by the hmw1 gene cluster and shares homology with a group of bacterial proteins that are generally associated with two-partner secretion systems. In addition, we demonstrate that HMW1C is capable of transferring glucose and galactose to HMW1 and is also able to generate hexose-hexose bonds. Our results define a new family of bacterial glycosyltransferases

Emission-line stars discovered in the UKST H-alpha survey of the Large Magellanic Cloud; Part 1: Hot stars

We present new, accurate positions, spectral classifications, radial and rotational velocities, H-alpha fluxes, equivalent widths and B,V,I,R magnitudes for 579 hot emission-line stars (classes B0 - F9) in the Large Magellanic Cloud which include 469 new discoveries. Candidate emission line stars were discovered using a deep, high resolution H-alpha map of the central 25 deg2 of the LMC obtained by median stacking a dozen 2 hour H-alpha exposures taken with the UK Schmidt Telescope. Spectroscopic follow-up observations on the AAT, UKST, VLT, the SAAO 1.9m and the MSSSO 2.3m telescope have established the identity of these faint sources down to magnitude R~23 for H-alpha (4.5 x 10^-17 ergs cm^2 s^-1 Ang). Confirmed emission-line stars have been assigned an underlying spectral classification through cross-correlation against 131 absorption line template spectra covering the range O1 to F8. We confirm 111 previously identified emission line stars and 64 previously known variable stars with spectral types hotter than F8. The majority of hot stars identified (518 stars or 89%) are class B. Of all the hot emission-line stars in classes B-F, 130 or 22% are type B[e], characterised by the presence of forbidden emission lines such as [SII], [NII] and [OII]. We report on the physical location of these stars with reference to possible contamination from ambient HII emission. Along with flux calibration of the H-alpha emission we provide the first H-alpha luminosity function for selected sub-samples after correction for any possible nebula or ambient contamination. We find a moderate correlation between the intensity of H-alpha emission and the V magnitude of the central star based on SuperCOSMOS magnitudes and OGLE-II photometry where possible. Cool stars from classes G-S, with and without strong H-alpha emission, will be the focus of part 2 in this series.Comment: 24 pages (main paper) 36 figures, 6 tables; Appendix Tables: 22 pages, MNRAS, 201

C-terminal phosphorylation of NaV1.5 impairs FGF13-dependent regulation of channel inactivation

International audienceVoltage-gated Na(+) (NaV) channels are key regulators of myocardial excitability, and Ca(2+)/calmodulin-dependent protein kinase II (CaMKII)-dependent alterations in NaV1.5 channel inactivation are emerging as a critical determinant of arrhythmias in heart failure. However, the global native phosphorylation pattern of NaV1.5 subunits associated with these arrhythmogenic disorders and the associated channel regulatory defects remain unknown. Here, we undertook phosphoproteomic analyses to identify and quantify in situ the phosphorylation sites in the NaV1.5 proteins purified from adult WT and failing CaMKIIδc-overexpressing (CaMKIIδc-Tg) mouse ventricles. Of 19 native NaV1.5 phosphorylation sites identified, two C-terminal phosphoserines at positions 1938 and 1989 showed increased phosphorylation in the CaMKIIδc-Tg compared with the WT ventricles. We then tested the hypothesis that phosphorylation at these two sites impairs fibroblast growth factor 13 (FGF13)-dependent regulation of NaV1.5 channel inactivation. Whole-cell voltage-clamp analyses in HEK293 cells demonstrated that FGF13 increases NaV1.5 channel availability and decreases late Na(+) current, two effects that were abrogated with NaV1.5 mutants mimicking phosphorylation at both sites. Additional co-immunoprecipitation experiments revealed that FGF13 potentiates the binding of calmodulin to NaV1.5 and that phosphomimetic mutations at both sites decrease the interaction of FGF13 and, consequently, of calmodulin with NaV1.5. Together, we have identified two novel native phosphorylation sites in the C terminus of NaV1.5 that impair FGF13-dependent regulation of channel inactivation and may contribute to CaMKIIδc-dependent arrhythmogenic disorders in failing hearts

Proteomic analyses of native brain KV4.2 channel complexes

Somatodendritic A-type (I(A)) voltage-gated K(+) (K(V)) channels are key regulators of neuronal excitability, functioning to control action potential waveforms, repetitive firing and the responses to synaptic inputs. Rapidly activating and inactivating somatodendritic I(A) channels are encoded by K(V)4 α subunits and accumulating evidence suggests that these channels function as components of macromolecular protein complexes. Mass spectrometry (MS)-based proteomic approaches were developed and exploited here to identify potential components and regulators of native brain K(V)4.2-encoded I(A) channel complexes. Using anti-K(V)4.2 specific antibodies, K(V)4.2 channel complexes were immunoprecipitated from adult wild type mouse brain. Parallel control experiments were performed on brain samples isolated from (K(V)4.2(−/−)) mice harboring a targeted disruption of the KCND2 (K(V)4.2) locus. Three proteomic strategies were employed: an in-gel approach, coupled to one-dimensional liquid chromatography-tandem MS (1D-LC-MS/MS), and two in-solution approaches, followed by 1D-or 2D-LC-MS/MS. The targeted in-gel 1D-LC-MS/MS analyses demonstrated the presence of the K(V)4 α subunits (K(V)4.2, K(V)4.3 and K(V)4.1) and the K(V)4 accessory, KChIP (KChIPI-4) and DPP (DPP6 and 10), proteins in native brain K(V)4.2 channel complexes. The more comprehensive, in-solution approach, coupled to 2D-LC-MS/MS, also called Multidimensional Protein Identification Technology (MudPIT), revealed that additional regulatory proteins, including the K(V) channel accessory subunit K(V)β1, are also components of native brain K(V)4.2 channel complexes. Additional biochemical and functional approaches will be required to elucidate the physiological roles of these newly identified K(V)4 interacting proteins