bluuebunny/crossref_metadata_2025 huggingface dataset:
Recovery of a Recombinant Salmonid Alphavirus Fully Attenuated and Protective for Rainbow Trout
Authors: Moriette Coralie , LeBerre Monique , Lamoureux Annie , Lai Thanh-Lan , Brémont Michel
Published: March 2006

Sleeping disease virus
(SDV) is a member of the new
Salmonid alphavirus
genus within the
Togaviridae
family. The single-stranded RNA genome of SDV is 11,894 nucleotides long, excluding the 3′ poly(A) tail. A full-length cDNA has been generated; the cDNA was fused to a hammerhead ribozyme sequence at the 5′ end and inserted into a transcription plasmid (pcDNA3) backbone, yielding pSDV. By transfection of pSDV into fish cells, recombinant SDV (rSDV) was successfully recovered. Demonstration of the recovery of rSDV was provided by immunofluorescence assay on rSDV-infected cells and by the presence of a genetic tag, a BlpI restriction enzyme site, introduced into the rSDV RNA genome. SDV infectious cDNA was used for two kinds of experiments (i) to evaluate the impact of various targeted mutations in nsP2 on viral replication and (ii) to study the virulence of rSDV in trout. For the latter aspect, when juvenile trout were infected by immersion in a water bath with the wild-type virus-like rSDV, no deaths or signs of disease appeared in fish, although they were readily infected. In contrast, cumulative mortality reached 80% in fish infected with the wild-type SDV (wtSDV). When rSDV-infected fish were challenged with wtSDV 3 and 5 months postinfection, a long-lasting protection was demonstrated. Interestingly, a variant rSDV (rSDV
14
) adapted to grow at a higher temperature, 14°C instead of 10°C, was shown to become pathogenic for trout. Comparison of the nucleotide sequences of wtSDV, rSDV, and rSDV
14
genomes evidenced several amino acid changes, and some changes may be linked to the pathogenicity of SDV in trout.
Apoptosis of Liver-Derived Cells Induced by Parvovirus B19 Nonstructural Protein
Authors: Poole Brian D. , Zhou Jing , Grote Amy , Schiffenbauer Adam , Naides Stanley J.
Published: March 2006

Parvovirus B19 has been implicated in some cases of acute fulminant non-A, non-B, non-C, non-G liver failure. Our laboratory previously demonstrated that B19 infection of hepatocytes induces apoptosis and that the B19 viral nonstructural protein, NS1, may play a critical role. To study the involvement of NS1 in apoptosis of liver cells, we generated a fusion protein of NS1 with enhanced green fluorescent protein (eGFP) in a system allowing for inducible gene expression. Transfection of the liver-derived cell line HepG2 with the eGFP/NS1 vector allowed expression of the fusion protein, which was visualized by fluorescence microscopy and demonstrated by immunoblotting. The fusion protein localized to discrete domains in the nucleus. Transfection of HepG2 cells with the eGFP/NS1 vector led to apoptosis of 35% of transfected cells, a sevenfold increase over cells transfected with the parent eGFP expression vector. Mutation of the eGFP/NS1 vector to eliminate the nucleoside triphosphate-binding site of NS1 significantly decreased apoptosis, as did treatment of transfected cells with inhibitors of caspase 3 or 9. Neutralization of tumor necrosis factor alpha or Fas ligand had no effect on apoptosis. These results demonstrate that NS1 is sufficient to induce apoptosis in liver-derived cells and that it does so through the initiation of an intrinsic caspase pathway.
Formation of nsP3-Specific Protein Complexes during Sindbis Virus Replication
Authors: Frolova Elena , Gorchakov Rodion , Garmashova Natalia , Atasheva Svetlana , Vergara Leoncio A. , Frolov Ilya
Published: March 2006

Alphaviruses are arthropod-borne viruses (arboviruses) that include a number of important human and animal pathogens. Their replication proceeds in the cytoplasm of infected cells and does not directly depend on nuclei. Alphaviruses encode only four nonstructural proteins that are required for the replication of viral genome and transcription of the subgenomic RNA. However, the replicative enzyme complexes (RCs) appear to include cellular proteins and assemble on cellular organelles. We have developed a set of recombinant Sindbis (SIN) viruses with green fluorescent protein (GFP) insertions in one of the nonstructural proteins, nsP3, to further understand the RCs' genesis and structure. We studied the assembly of nsP3/GFP-containing protein complexes at different stages of infection and isolated a combination of cellular proteins that are associated with SIN nsP3. We demonstrated the following. (i) SIN nsP3 can tolerate the insertion of GFP into different fragments of the coding sequence; the designed recombinant viruses are viable, and their replication leads to the assembly of nsP3/GFP chimeric proteins into gradually developing, higher-order structures differently organized at early and late times postinfection. (ii) At late times postinfection, nsP3 is assembled into complexes of similar sizes, which appear to be bound to cytoskeleton filaments and can aggregate into larger structures. (iii) Protein complexes that are associated with nsP3/GFP contain a high concentration of cytoskeleton proteins, chaperones, elongation factor 1A, heterogeneous nuclear ribonucleoproteins, 14-3-3 proteins, and some of the ribosomal proteins. These proteins are proposed to be essential for SIN RC formation and/or functioning.
Baculovirus-Mediated Gene Delivery into Mammalian Cells Does Not Alter Their Transcriptional and Differentiating Potential but Is Accompanied by Early Viral Gene Expression
Authors: Kenoutis Christos , Efrose Rodica C. , Swevers Luc , Lavdas Alexandros A. , Gaitanou Maria , Matsas Rebecca , Iatrou Kostas
Published: March 2006

Gene delivery to neural cells is central to the development of transplantation therapies for neurological diseases. In this study, we used a baculovirus derived from the domesticated silk moth,
Bombyx mori
, as vector for transducing a human cell line (HEK293) and primary cultures of rat Schwann cells. Under optimal conditions of infection with a recombinant baculovirus containing the reporter green fluorescent protein gene under mammalian promoter control, the infected cells express the transgene with high efficiency. Toxicity assays and transcriptome analyses suggest that baculovirus infection is not cytotoxic and does not induce differential transcriptional responses in HEK293 cells. Infected Schwann cells retain their characteristic morphological and molecular phenotype as determined by immunocytochemistry for the marker proteins S-100, glial fibrillary acidic protein, and p75 nerve growth factor receptor. Moreover, baculovirus-infected Schwann cells are capable of differentiating in vitro and express the P0 myelination marker. However, transcripts for several immediate-early viral genes also accumulate in readily detectable levels in the transduced cells. This transcriptional activity raises concerns regarding the long-term safety of baculovirus vectors for gene therapy applications. Potential approaches for overcoming the identified problem are discussed.
Cell Cycle Perturbations Induced by Infection with the Coronavirus Infectious Bronchitis Virus and Their Effect on Virus Replication
Authors: Dove Brian , Brooks Gavin , Bicknell Katrina , Wurm Torsten , Hiscox Julian A.
Published: March 2006

In eukaryotic cells, cell growth and division occur in a stepwise, orderly fashion described by a process known as the cell cycle. The relationship between positive-strand RNA viruses and the cell cycle and the concomitant effects on virus replication are not clearly understood. We have shown that infection of asynchronously replicating and synchronized replicating cells with the avian coronavirus infectious bronchitis virus (IBV), a positive-strand RNA virus, resulted in the accumulation of infected cells in the G
2
/M phase of the cell cycle. Analysis of various cell cycle-regulatory proteins and cellular morphology indicated that there was a down-regulation of cyclins D1 and D2 (G
1
regulatory cyclins) and that a proportion of virus-infected cells underwent aberrant cytokinesis, in which the cells underwent nuclear, but not cytoplasmic, division. We assessed the impact of the perturbations on the cell cycle for virus-infected cells and found that IBV-infected G
2
/M-phase-synchronized cells exhibited increased viral protein production when released from the block when compared to cells synchronized in the G
0
phase or asynchronously replicating cells. Our data suggested that IBV induces a G
2
/M phase arrest in infected cells to promote favorable conditions for viral replication.
Characterization of a Torovirus Main Proteinase
Authors: Smits Saskia L. , Snijder Eric J. , de Groot Raoul J.
Published: March 2006

Viruses
of the order
Nidovirales
encode huge replicase polyproteins.
These are processed primarily by the chymotrypsin-like main proteinases
(M
pro
s). So far, M
pro
s have been studied only for
corona-, arteri-, and roniviruses. Here, we report the characterization
of the M
pro
of toroviruses, the fourth main Nidovirus
branch. Comparative sequence analysis of polyprotein 1a of equine
torovirus (EToV) strain Berne, identified a serine proteinase domain,
flanked by hydrophobic regions. Heterologous expression of this domain
resulted in autoprocessing at flanking cleavage sites. N-terminal
sequence analysis of cleavage products tentatively identified
FxxQ↓(S, A) as the substrate consensus sequence. EToV
M
pro
combines several traits of its closest relatives. It
has a predicted three-domain structure, with two catalyticβ
-barrel domains and an additional C-terminal domain of unknown
function. With respect to substrate specificity, the EToV
M
pro
resembles its coronavirus homologue in its preference
for P1-Gln, but its substrate-binding subsite, S1, more closely
resembles that of arteri- and ronivirus M
pro
s, which prefer
P1-Glu. Surprisingly, in contrast to the M
pro
s of corona-
and roniviruses, but like that of arterivirus, the torovirus
M
pro
uses serine instead of cysteine as its principal
nucleophile. Under the premise that the M
pro
s of corona- and
toroviruses are more closely related to each other than to those of
arteri- and roniviruses, the transition from serine- to cysteine-based
proteolytic catalysis (or vice versa) must have happened more than once
in the course of nidovirus evolution. In this respect, it is of
interest that a mutant EToV M
pro
with a
Ser
165
→Cys substitution retained partial enzymatic
activity.
Role of Endosomal Cathepsins in Entry Mediated by the Ebola Virus Glycoprotein
Authors: Schornberg Kathryn , Matsuyama Shutoku , Kabsch Kirsten , Delos Sue , Bouton Amy , White Judith
Published: March 2006

Using chemical inhibitors and small interfering RNA (siRNA), we have confirmed roles for cathepsin B (CatB) and cathepsin L (CatL) in Ebola virus glycoprotein (GP)-mediated infection. Treatment of Ebola virus GP pseudovirions with CatB and CatL converts GP1 from a 130-kDa to a 19-kDa species. Virus with 19-kDa GP1 displays significantly enhanced infection and is largely resistant to the effects of the CatB inhibitor and siRNA, but it still requires a low-pH-dependent endosomal/lysosomal function. These and other results support a model in which CatB and CatL prime GP by generating a 19-kDa intermediate that can be acted upon by an as yet unidentified endosomal/lysosomal enzyme to trigger fusion.
Hepatitis C Virus Protease Gene Diversity in Patients Coinfected with Human Immunodeficiency Virus
Authors: Winters Mark A. , Welles Seth L. , Holodniy Mark
Published: March 2006

The clonal variability of the hepatitis C virus (HCV) protease gene in 24 individuals with HCV genotypes 1a, 1b, 2b, and 3a who were coinfected with the human immunodeficiency virus was evaluated. Within-genotype variability at the nucleotide and amino acid levels ranged from 6.5 to 8.6% and 2.2 to 3.8%, respectively. After adjustments were made for correlation of intrapatient clonal variation, mixed-model analysis indicated that nucleotide and amino acid variability among patients with different genotypes did not differ significantly. However, within individual patients, clonal variability differed by up to 5.3% and 5.8% at the nucleotide and amino acid levels, respectively, and genotype 1a had significantly greater nucleotide variability than other genotypes (
P
= 0.01). Significant variability exists within HCV protease gene variants at the patient level and could affect the effectiveness of HCV protease inhibitors.
Murine Cytomegalovirus Interference with Antigen Presentation Contributes to the Inability of CD8 T Cells To Control Virus in the Salivary Gland
Authors: Lu Xiuju , Pinto Amelia K. , Kelly Ann M. , Cho Kathy S. , Hill Ann B.
Published: March 2006

Compared to other organs, murine cytomegalovirus (MCMV) replication in the salivary gland is uniquely resistant to CD8 T-cell control. The contribution of viral genes that interfere with antigen presentation (VIPRs) to this resistance was assessed using a mutant lacking MCMV's known VIPRs. Salivary gland titers of the VIPR-deficient virus were at least 10-fold lower than those of the wild type during the persistent phase of infection; the defect was reversed by depleting CD8 T cells. Thus, VIPRs contribute to CD8 T cells' inability to control virus in the salivary gland.
Torsion of the testicular appendix: importance of associated acute inflammation
Authors: Rakha E , Puls F , Saidul I , Furness P
Published: March 2006

Background:Torsion of the testicular appendix is the commonest cause of acute scrotum in children. The histological picture of these cases is variable and many show a heavy acute inflammatory cell infiltrate, unlike the response to pure ischaemic necrosis in other organs. The clinical implications and consequences of this associated inflammation are not clear.

Methods:A retrospective review of all cases presenting with torsion of the testicular appendix between 1987 and 2005 was carried out. In all, 79 cases were reviewed and the degree of acute inflammatory cell infiltrate and other morphological parameters were assessed and compared with the patients’ clinical, operative and postoperative findings. Stains for bacteria and fungi were examined.

Results:A positive correlation was found between the severity of acute inflammatory cell infiltrates and the longer duration of symptoms and presence of clinical evidence of torsion of the testicular appendages. No other association was detected between the pattern or degree of acute inflammatory cell infiltrate and any other clinicopathological variable that may indicate pyogenic infection. No bacteria or fungal elements were identified. Marked lymphatic dilation may be the only histological finding to indicate the presence of early torsion in cases of scrotal pain secondary to torsion of the appendix testis.

Conclusion:Heavy acute inflammatory cell infiltrates in the torted testicular appendix can be regarded as marker of progression of this condition. Investigation for infection is therefore not necessary in such cases.
SOME NON-PERTURBATIVE PATH INTEGRALS STUDIES IN STATISTICAL BURGER TURBULENCE: STRINGS AND STOCHASTIC INSTANTONS CONFIGURATIONS
Authors: BOTELHO LUIZ C. L.
Published: March 2006

In this paper, we study Burger turbulence and the appearance of spatial coherent string dynamics structures for the statistical averaged vortex phase factor in a path integral framework. This result gives a strong mathematical method support to the unsolved long-standing Landau 1941's conjecture that in a turbulent field the flow vorticity should be confined to a limited region.

Additionally, we present the exact instanton path-integral solubility — from a stochastic point of view — of a fluid flow bounded by a moving string (random) boundary together with a study of another exact path-integral solubility of a weakly stirred complete Navier–Stokes flow.
COOLING RATE EFFECTS ON DYNAMICS IN SUPERCOOLED Al2O3
Authors: HOANG VO VAN , OH SUHK KUN
Published: March 2006

The cooling rate effects in supercooled Al 2 O 3 have been investigated by Molecular Dynamics (MD) method. Simulations were done in the basic cube under periodic boundary conditions containing 3000 ions with Born–Mayer type pair potentials. The temperature of the system was decreased linearly in time as T(t)=T0–γt, where γ is the cooling rate. The cooling rate dependence of density, thermal expansion coefficient and enthalpy of the system was found. Structure of amorphous Al 2 O 3 model at the temperature of 0 K was in good agreement with Lamparter's experimental data. The cooling rate dependence of the dynamical heterogeneities in supercooled states has been studied through the comparison of the partial radial distribution functions (PRDFs) for the 10% most mobile or immobile particles with the corresponding mean PRDFs in the models. Also, cooling rate effects on the cluster size distributions of the most mobile or immobile particles have been obtained. Calculations show that the cooling rate effects on the dynamical heterogeneities are pronounced. Finally, the evolution of structural defects and cluster size distributions of the most mobile or immobile particles in the system upon cooling has been studied and presented.
ASYNCHRONOUS RANDOM BOOLEAN NETWORK MODEL WITH VARIABLE NUMBER OF PARENTS BASED ON ELEMENTARY CELLULAR AUTOMATA RULE 126
Authors: MATACHE MIHAELA T.
Published: March 2006

A Boolean network with N nodes, each node's state at time t being determined by a certain number of parent nodes, which can vary from one node to another, is considered. This is a generalization of previous results obtained for a constant number of parent nodes, by Matache and Heidel in "Asynchronous Random Boolean Network Model Based on Elementary Cellular Automata Rule 126", Phys. Rev. E71, 026 232, 2005. The nodes, with randomly assigned neighborhoods, are updated based on various asynchronous schemes. The Boolean rule is a generalization of rule 126 of elementary cellular automata, and is assumed to be the same for all the nodes. We provide a model for the probability of finding a node in state 1 at a time t for the class of generalized asynchronous random Boolean networks (GARBN) in which a random number of nodes can be updated at each time point. We generate consecutive states of the network for both the real system and the models under the various schemes, and use simulation algorithms to show that the results match well. We use the model to study the dynamics of the system through sensitivity of the orbits to initial values, bifurcation diagrams, and fixed point analysis. We show that the GARBN's dynamics range from order to chaos, depending on the type of random variable generating the asynchrony and the parameter combinations.
DYNAMIC SPIN TRANSPORT IN NONMAGNETIC SEMICONDUCTOR SYSTEMS
Authors: TANG CHI-SHUNG
Published: March 2006

We present a brief review to our recent study concerning dynamic spin transport induced by AC-biased gate in low-dimensional semiconductor systems, in which dynamic spin-orbit interaction plays a crucial role. We construct a Boltzmann spin-transport model and a spin-drift-diffusion model to describe the time-dependent spin transport starting with the framework of Keldysh formalism. Methods for the generation and direct detection of spin current are proposed without optical and magnetic mediators.
TERAHERTZ RADIATION IN SUPERLATTICES IN MODERATE ELECTRIC FIELD
Authors: HAN PENG , JIN KUI-JUAN , ZHOU YUE-LIANG , ZHOU QING-LI , HIRAKAWA K.
Published: March 2006

We have studied the terahertz (THz) radiation in superlattices (SLs) in moderate electric field region (between 12 kV/cm and 25 kV/cm) from both theoretical and experimental aspects in this work. The THz emission intensity has been calculated for three samples of GaAs/Al 0.3 Ga 0.7 As SLs by using Kane model. The theoretical results show that the radiation intensity increases until the electric field F achieves a certain value between 14 kV/cm and 16 kV/cm for various samples, and then starts to roll off. The agreement of the calculated results with the experimental data demonstrates that the rolling of THz radiation intensity is due to the competition of field induced localization of wave functions and the increasing of the photon energy in THz radiation with increased electric fields. Furthermore, it is also shown that THz radiation intensity can be affected by the scattering of the randomly distributed Al atoms in the barriers.
GLOBAL BIFURCATIONS IN DUOPOLY WHEN THE COURNOT POINT IS DESTABILIZED VIA A SUBCRITICAL NEIMARK BIFURCATION
Authors: AGLIARI ANNA , GARDINI LAURA , PUU TONU
Published: March 2006

An adaptive oligopoly model, where the demand function is isoelastic and the competitors operate under constant marginal costs, is considered. The Cournot equilibrium point then loses stability through a subcritical Neimark bifurcation. The present paper focuses some global bifurcations, which precede the Neimark bifurcation, and produce other attractors which coexist with the still attractive Cournot fixed point.
HERDING WITH COSTLY INFORMATION
Authors: KULTTI KLAUS , MIETTINEN PAAVO
Published: March 2006

We consider a standard sequential decision to adopt/buy a good in a herding environment. The setup is same as in Sgroi (2002). Contrary to the basic herding case we introduce a cost that the agents have to pay for the information about their predecessors' actions. All agents receive informative signals as in the standard herding models but do not view the actions taken by their predecessors unless they pay the observation costs. In this set up the first and the second agents rely on their own signals when they make the decision to adopt/buy the good. Only the third agent is willing to buy the information on all of the preceding agents' actions. All agents following the third agent buy information on only one agent's action and decide to adopt/buy the good after updating their beliefs. What follows is that the two first agents' actions determine whether the rest of the agents will adopt/buy the good or not when information about the predecessors' actions is cheap enough. If the cost of the information about the predecessors' actions is very expensive then all the agents will act according to their own signals. If observing is free one gets the standard results. In essence we identify a discontinuity in the basic herding model since the herding arises deterministically when a small observation cost is introduced.
(∊,k) EQUILIBRIA AND WELL-POSEDNESS
Authors: MARGIOCCO MARCO , PUSILLO LUCIA
Published: March 2006

The aim of this paper is to discuss a new concept of well-posedness for non cooperative games. Starting from the definition of (∊,k) equilibrium as the point where every player either guarantees at least k or he (she) does not lose more than ∊, we introduce an original definition of well-posedness. We study characterizations of this well-posedness and its relations with the more known Tikhonov well-posedness. We prove that this well-posedness is an ordinal property if the payoff functions are bounded from below.
A GENERALIZED MODEL OF BEST RESPONSE ADAPTATION
Authors: BERGER ULRICH
Published: March 2006

We present a generalized model of myopic best response adaptation in large populations. In asymmetric conflicts, individuals can be in the role of the row player or the column player. The idea that an individual's role need not be fixed is introduced explicitly in our model by a process of role switching. The best response dynamics, the symmetrized best response dynamics, and the continuous time fictitious play process are included as special cases. We show that the set of Nash equilibria is attracting for zero-sum games. Moreover, for any base game, convergence to a Nash equilibrium implies convergence to a Nash equilibrium on the Wright manifold in the role game.
RATIONALIZATION IN SIGNALING GAMES: THEORY AND APPLICATIONS
Authors: BATTIGALLI PIERPAOLO
Published: March 2006

Focusing on signaling games, I illustrate the relevance of the rationalizability approach for the analysis multistage games with incomplete information. I define a class of iterative solution procedures, featuring a notion of "forward induction": the Receiver tries to explain the Sender's message in a way which is consistent with the Sender's strategic sophistication and certain given restrictions on beliefs. The approach is applied to some numerical examples and economic models. In a standard model with verifiable messages a full disclosure result is obtained. In a model of job market signaling the best separating equilibrium emerges as the unique rationalizable outcome only when the high and low types are sufficiently different. Otherwise, rationalizability only puts bounds on the education choices of different types.
GENERALIZED CORES AND STABLE SETS FOR FUZZY GAMES
Authors: MUTO S. , ISHIHARA S. , FUKUDA E. , TIJS S. H. , BRÂNZEI R.
Published: March 2006

Core elements (a la Aubin) of a fuzzy game can be associated with additive separable supporting functions of fuzzy games. Generalized cores whose elements consist of more general separable supporting functions of the game are introduced and studied. While the Aubin core of unanimity games can be empty, the generalized core of unanimity games is nonempty. Properties of the generalized cores and their relations to stable sets are studied. For convex fuzzy games interesting properties are found such as the fact that the generalized core is a unique generalized stable set.
COALITION FORMATION IN GAMES WITHOUT SYNERGIES
Authors: CURRARINI SERGIO , MARINI MARCO A.
Published: March 2006

This paper establishes sufficient conditions for the existence of a stable coalition structure in the "coalition unanimity" game of coalition formation, first defined by Hart and Kurz (1983) and more recently studied by Yi (1997, 2003). Our conditions are defined on the strategic form game used to derive the payoffs of the game of coalition formation. We show that if no synergies are generated by the formation of coalitions, a stable coalition structure always exists provided that players are symmetric and either the game exhibits strategic complementarity or, if strategies are substitutes, the best reply functions are contractions.
CLASSICAL TELEPORTATION OF CLASSICAL STATES
Authors: COHEN OLIVER
Published: March 2006

The standard quantum teleportation scheme is deconstructed, and those aspects of it that appear remarkable and "non-classical" are identified. An alternative teleportation scheme, involving only classical states and classical information, is then formulated, and it is shown that the classical scheme reproduces all of these remarkable aspects, despite the fact that they had seemed non-classical. This leads to a re-examination of quantum teleportation, which suggests that its significance depends on the interpretation of quantum states.
ALIGNING SPATIAL FRAMES THROUGH QUANTUM CHANNELS
Authors: BAGAN E. , MUÑOZ-TAPIA R.
Published: March 2006

We review the optimal protocols for aligning spatial frames using quantum systems. The communication problem addressed here concerns a type of information that cannot be digitalized. Asher Peres referred to it as "unspeakable information." We comment on his contribution to this subject and give a brief account of his scientific interaction with the authors.
DIALOGUE CONCERNING TWO VIEWS ON QUANTUM COHERENCE: FACTIST AND FICTIONIST
Authors: BARTLETT STEPHEN D. , RUDOLPH TERRY , SPEKKENS ROBERT W.
Published: March 2006

A controversy that has arisen many times over in disparate contexts is whether quantum coherences between eigenstates of certain quantities are fact or fiction. We present a pedagogical introduction to the debate in the form of a hypothetical dialogue between proponents from each of the two camps: a factist and a fictionist. A resolution of the debate can be achieved, we argue, by recognizing that quantum states do not only contain information about the intrinsic properties of a system but about its extrinsic properties as well, that is, about its relation to other systems external to it. Specifically, the coherent quantum state of the factist is the appropriate description of the relation of the system to one reference frame, while the incoherent quantum state of the fictionist is the appropriate description of the relation of the system to another, uncorrelated, reference frame. The two views, we conclude, are alternative but equally valid paradigms of description.
CAN QUANTUM-MECHANICAL DESCRIPTION OF PHYSICAL REALITY BE CONSIDERED INCOMPLETE?
Authors: BRASSARD GILLES , MÉTHOT ANDRÉ ALLAN
Published: March 2006

In loving memory of Asher Peres, we discuss a most important and influential paper written in 1935 by his thesis supervisor and mentor Nathan Rosen, together with Albert Einstein and Boris Podolsky. In that paper, the trio known as EPR questioned the completeness of quantum mechanics. The authors argued that the then-new theory should not be considered final because they believed it incapable of describing physical reality. The epic battle between Einstein and Bohr intensified following the latter's response later the same year. Three decades elapsed before John S. Bell gave a devastating proof that the EPR argument was fatally flawed. The modest purpose of our paper is to give a critical analysis of the original EPR paper and point out its logical shortcomings in a way that could have been done 70 years ago, with no need to wait for Bell's theorem. We also present an overview of Bohr's response in the interest of showing how it failed to address the gist of the EPR argument.
TWO-WAY QUANTUM COMMUNICATION CHANNELS
Authors: CHILDS ANDREW M. , LEUNG DEBBIE W. , LO HOI-KWONG
Published: March 2006

We consider communication between two parties using a bipartite quantum operation, which constitutes the most general quantum mechanical model of two-party communication. We primarily focus on the simultaneous forward and backward communication of classical messages. For the case in which the two parties share unlimited prior entanglement, we give inner and outer bounds on the achievable rate region that generalize classical results due to Shannon. In particular, using a protocol of Bennett, Harrow, Leung, and Smolin, we give a one-shot expression in terms of the Holevo information for the entanglement-assisted one-way capacity of a two-way quantum channel. As applications, we rederive two known additivity results for one-way channel capacities: the entanglement-assisted capacity of a general one-way channel, and the unassisted capacity of an entanglement-breaking one-way channel.
ON THE EXACT IDENTITY BETWEEN THERMODYNAMIC AND INFORMATIC ENTROPIES IN A UNITARY MODEL OF FRICTION
Authors: DIÓSI LAJOS , FELDMANN TOVA , KOSLOFF RONNIE
Published: March 2006

We consider an elementary collision model of a molecular reservoir upon which an external field is applied and the work is dissipated into heat. To realize macroscopic irreversibility at the microscopic level, we introduce a "graceful" irreversible map which randomly mixes the identities of the molecules. This map is expected to generate informatic entropy exactly equal to the independently calculable irreversible thermodynamic entropy.
QUANTUM ESTIMATION OF RELATIVE INFORMATION
Authors: LINDNER NETANEL H. , SCUDO PETRA F. , BRUß DAGMAR
Published: March 2006

We derive optimal schemes for preparation and estimation of relational degrees of freedom between two quantum systems. We specifically analyze the case of rotation parameters representing relative angles between elements of the SU(2) symmetry group. Our estimation procedure does not assume prior knowledge of the absolute spatial orientation of the systems and as such does not require information on the underlying classical reference frame in which the states are prepared.
REMOTE GENERALIZED MEASUREMENTS USING PARTIALLY ENTANGLED STATES
Authors: REZNIK B.
Published: March 2006

We propose a method for implementing remotely a generalized measurement (POVM). We show that remote generalized measurements consume less entanglement compared with remote projective measurements, and can be optimally performed using non-maximally entangled states. We derive the entanglement cost of such measurements.
THOUGHTS ON NON-LOCALITY AND QUANTUM MECHANICS
Authors: UNRUH W.
Published: March 2006

The debate about the non-locality of quantum mechanics is old, but still lively. Numerous people use non-locality as (bad) shorthand for quantum entanglement. But some have a long-standing commitment to the validity of this characterization. This paper examines two separate streams in this debate. The first is the arguments of Stapp, and especially his recent paper where he simplifies his contractual argument in the Hardy situation to argue for the non-locality of quantum mechanics. He has maintained his contention that an analysis of a Hardy-type correlation between two spatially separated observers proves that quantum mechanics itself is non-local, without any additional assumption of realism or hidden variables. In the second section, I try to carefully examine the Bell argument in the CHSH variant to see where the difference between the quantum and classical situations differ.

Asher Peres was one of the great physicists of the late 20th century, especially for his intense concern with the fundamental nature of quantum mechanics. His courage in devoting his life to an area many considered "philosophical" (i.e. non-physical) paved the way for the rest of us to reveal our interests and confusions about this area. I am not sure that he would agree with everything in this paper, but I offer it as a tribute to him.
RELATIVISTIC QUANTUM INFORMATION PROCESSING WITH BOSONIC AND FERMIONIC INTERFEROMETERS
Authors: KOK PIETER , BRAUNSTEIN SAMUEL L.
Published: March 2006

We derive the relativistic transformation laws for the annihilation operators of the scalar field, the massive spin-1 vector field, the electromagnetic field and the spinor field. The technique developed here involves straightforward mathematical techniques based on fundamental quantum field theory, and is applicable to the study of entanglement in arbitrary coordinate transformations. In particular, it predicts particle creation for non-inertial motion. Furthermore, we present a unified description of relativistic transformations and multi-particle interferometry with bosons and fermions, which encompasses linear optical quantum computing.
QUANTUMNESS OF ENSEMBLE FROM NO-BROADCASTING PRINCIPLE
Authors: HORODECKI MICHAł , HORODECKI PAWEł , HORODECKI RYSZARD , PIANI MARCO
Published: March 2006

Quantum information, though not precisely defined, is a fundamental concept of quantum information theory which predicts many fascinating phenomena and provides new physical resources. A basic problem is to recognize the features of quantum systems responsible for those phenomena. One of these important features is that non-commuting quantum states cannot be broadcast: two copies cannot be obtained out of a single copy, not even reproduced marginally on separate systems. We focus on the difference in information content between one copy and two copies, which is a basic manifestation of the gap between quantum and classical information. We show that if the chosen information measure is the Holevo quantity, the difference between the information content of one copy and two copies is zero if and only if the states can be broadcast. We propose a new approach in defining measures of quantumness of ensembles based on the difference in information content between the original ensemble and the ensemble of duplicated states. We comment on the permanence property of quantum states and the recently introduced superbroadcasting operation. We also provide an appendix where we discuss the status of quantum information in quantum physics, based on the so-called isomorphism principle.
ON CLASSICAL TELEPORTATION AND CLASSICAL NON-LOCALITY
Authors: MOR TAL
Published: March 2006

An interesting protocol for classical teleportation of an unknown classical state was recently suggested by Cohen, and by Gour and Meyer. In that protocol, Bob can sample from a probability distribution [Formula: see text] that is given to Alice, even if Alice has absolutely no knowledge about [Formula: see text]. Pursuing a similar line of thought, we suggest here a limited form of non-locality — "classical non-locality." Our non-locality is the (somewhat limited) classical analogue of the Hughston–Jozsa–Wootters (HJW) quantum non-locality. The HJW non-locality (also known as "quantum remote steering") tells us how, for a given density matrix ρ, Alice can generate any ρ-ensemble on the North Star. This is done using surprisingly few resources — one shared entangled state (prepared in advance), one generalized quantum measurement, and no communication. Similarly, our classical non-locality (which we call "classical remote steering") presents how, for a given probability distribution [Formula: see text], Alice can generate any [Formula: see text]-ensemble on the North Star, using only one correlated state (prepared in advance), one (generalized) classical measurement, and no communication. It is important to clarify that while the classical teleportation and the classical non-locality protocols are probably rather insignificant from a classical information processing point of view, they significantly contribute to our understanding of what exactly is quantum in their well established and highly famous quantum analogues.
Decreased nutrient-stimulated insulin secretion in chronically hypoglycemic late-gestation fetal sheep is due to an intrinsic islet defect
Authors: Rozance Paul J. , Limesand Sean W. , Hay William W.
Published: March 2006

We measured in vivo and in vitro nutrient-stimulated insulin secretion in late gestation fetal sheep to determine whether an intrinsic islet defect is responsible for decreased glucose-stimulated insulin secretion (GSIS) in response to chronic hypoglycemia. Control fetuses responded to both leucine and lysine infusions with increased arterial plasma insulin concentrations (average increase: 0.13 ± 0.05 ng/ml leucine; 0.99 ± 0.26 ng/ml lysine). In vivo lysine-stimulated insulin secretion was decreased by chronic (0.37 ± 0.18 ng/ml) and acute (0.27 ± 0.19 ng/ml) hypoglycemia. Leucine did not stimulate insulin secretion following acute hypoglycemia but was preserved with chronic hypoglycemia (0.12 ± 0.09 ng/ml). Isolated pancreatic islets from chronically hypoglycemic fetuses had normal insulin and DNA content but decreased fractional insulin release when stimulated with glucose, leucine, arginine, or lysine. Isolated islets from control fetuses responded to all nutrients. Therefore, chronic late gestation hypoglycemia causes defective in vitro nutrient-regulated insulin secretion that is at least partly responsible for diminished in vivo GSIS. Chronic hypoglycemia is a feature of human intrauterine growth restriction (IUGR) and might lead to an islet defect that is responsible for the decreased insulin secretion patterns seen in human IUGR fetuses and low-birth-weight human infants.
Interhemispheric Integration at Different Spatial Scales: The Evidence From EEG Coherence and fMRI
Authors: Knyazeva Maria G. , Fornari Eleonora , Meuli Reto , Maeder Philippe
Published: March 2006

The early visual system processes different spatial frequencies (SFs) separately. To examine where in the brain the scale-specific information is integrated, we mapped the neural assemblies engaged in interhemispheric coupling with electroencephalographic (EEG) coherence and blood-oxygen-level dependent (BOLD) signal. During similar EEG and functional magnetic resonance imaging (fMRI) experiments, our subjects viewed centrally presented bilateral gratings of different SF (0.25–8.0 cpd), which either obeyed Gestalt grouping rules (iso-oriented, IG) or violated them (orthogonally oriented, OG). The IG stimuli (0.5–4.0 cpd) synchronized EEG at discrete beta frequencies (beta1, beta2) and increased BOLD (0.5 and 2.0 cpd tested) in ventral (around collateral sulcus) and dorsal (parieto-occipital fissure) regions compared with OG. At both SF, the beta1 coherence correlated with the ventral activations, whereas the beta2 coherence correlated with the dorsal ones. Thus distributed neural substrates mediated interhemispheric integration at single SF. The relative impact of the ventral versus dorsal networks was modulated by the SF of the stimulus.
Roll Rotation Cues Influence Roll Tilt Perception Assayed Using a Somatosensory Technique
Authors: Park Sukyung , Gianna-Poulin Claire , Black F. Owen , Wood Scott , Merfeld Daniel M.
Published: March 2006

We investigated how the nervous system processes ambiguous cues from the otolith organs by measuring roll tilt perception elicited by two motion paradigms. In one paradigm (tilt), eight subjects were sinusoidally tilted in roll with the axis of rotation near ear level. Stimulus frequencies ranged from 0.005 to 0.7 Hz, and the peak amplitude of tilt was 20°. During this paradigm, subjects experienced a sinusoidal variation of interaural gravitational force with a peak of 0.34 g. The second motion paradigm (translation) was designed to yield the same sinusoidal variation in interaural force but did not include a roll canal cue. This was achieved by sinusoidally translating the subjects along their interaural axis. For the 0.7-Hz translation trial, the subjects were simply translated from side to side. A centrifuge was used for the 0.005- to 0.5-Hz translation trials; the subjects were rotated in yaw at 250°/s for 5 min before initiating sinusoidal translations yielding an interaural otolith stimulus composed of both centrifugal and radial acceleration. Using a somatosensory task to measure roll tilt perception, we found substantial differences in tilt perception during the two motion paradigms. Because the primary difference between the two motion paradigms was the presence of roll canal cues during roll tilt trials, these perceptual differences suggest that canal cues influence tilt perception. Specifically, rotational cues provided by the semicircular canals help the CNS resolve ambiguous otolith cues during head tilt, yielding more accurate tilt perception.
Behavioral Reference Frames for Planning Human Reaching Movements
Authors: Beurze Sabine M. , Van Pelt Stan , Medendorp W. Pieter
Published: March 2006

At some stage in the process of a sensorimotor transformation for a reaching movement, information about the current position of the hand and information about the location of the target must be encoded in the same frame of reference to compute the hand-to-target difference vector. Two main hypotheses have been proposed regarding this reference frame: an eye-centered and a body-centered frame. Here we evaluated these hypotheses using the pointing errors that subjects made when planning and executing arm movements to memorized targets starting from various initial hand positions while keeping gaze fixed in various directions. One group of subjects ( n = 10) was tested without visual information about hand position during movement planning (unseen-hand condition); another group ( n = 8) was tested with hand and target position simultaneously visible before movement onset (seen-hand condition). We found that both initial hand position and gaze fixation direction had a significant effect on the magnitude and direction of the pointing error. Errors were significantly smaller in the seen-hand condition. For both conditions, though, a reference frame analysis showed that the errors arose at an eye- or hand-centered stage or both, but not at a body-centered stage. As a common reference frame is required to specify a movement vector, these results suggest that an eye-centered mechanism is involved in integrating target and hand position in programming reaching movements. We discuss how simple gain elements modulating the eye-centered target and hand-position signals can account for these results.
Gene expression profiling of target genes in ventilator-induced lung injury
Authors: Dolinay Tamás , Kaminski Naftali , Felgendreher Martina , Kim Hong P. , Reynolds Paul , Watkins Simon C. , Karp Dörte , Uhlig Stefan , Choi Augustine M. K.
Published: March 2006

In the lungs, high-pressure mechanical ventilation induces an inflammatory response similar to that observed in acute respiratory distress syndrome. To further characterize these responses and to compare them with classical inflammatory pathways, we performed gene expression profiling analysis of 20,000 mouse genes in isolated blood-free (to exclude genes from sequestered leukocytes) perfused mouse lungs exposed to low-pressure ventilation (10 cmH2O), high-pressure ventilation (25 cmH2O, overventilation), and LPS treatment. A large number of inflammatory and apoptotic genes were increased by both overventilation and LPS. However, certain growth factor-related genes, as well as genes related to development, cellular communication, and the cytoskeleton, were only regulated by overventilation. We validated and confirmed increased mRNA expression pattern of five genes (amphiregulin, gravin, Nur77, Cyr61, interleukin-11) by real-time PCR; furthermore, we confirmed increased protein expression of amphiregulin by immunohistochemistry and immunoblotting assays. These genes represent novel candidate genes in ventilator-induced lung injury.
Genomic imprinting in plants and mammals: how life history constrains convergence
Authors: Scott R.J. , Spielman M.
Published: March 2006

In both flowering plants and mammals, DNA methylation is involved in silencing alleles of imprinted genes, but surprising differences in imprinting control are emerging between the two taxa which may be traced to differences in their life cycles. Imprinted gene expression in plants occurs in the endosperm, a separate fertilisation product which transmits nutrients to the embryo and does not contribute a genome to the next generation. Regulation of expression of the known imprinted genes in Arabidopsis involves a cascade of gene expression beginning in the gametophyte, a haploid life phase interposed between the meiotic products and the gametes, which evolved from free-living organisms that constitute the dominant life phase of lower plants. Although the gametophytes of flowering plants are highly reduced they still express large numbers of genes, perhaps reflecting their evolutionary legacy, and which may now be recruited for control of imprinting. Strikingly, the genes at the top of the expression cascade appear to be specifically activated by demethylation, rather than targeted for silencing. Unlike in mammals, there is no evidence for global resetting of methylation in plants, and although imprinting involves the activity of a maintenance methyltransferase, de novo methyltransferases do not appear to be required. Plants do not set aside a germline; instead the cells that undergo meiosis to produce gametophytes differentiate in the adult plant during flower development. Both the late differentiation of the lineage producing germ cells, and the extent of gene expression during the haploid phase, may be incompatible with global resetting of methylation. Resetting may be unnecessary in any case because the adult plant expresses imprinted loci either biallelically or not at all, suggesting there is no chromosomal memory of parent-of-origin in the lineage that produces the gametophytes. Thus several features of the plant life cycle may account for the different strategies used by plants and animals to regulate parent-specific gene expression.
Imprinting control within the compact Gnas locus
Authors: Peters J. , Holmes R. , Monk D. , Beechey C.V. , Moore G.E. , Williamson C.M.
Published: March 2006

Mouse distal chromosome 2 was one of the earliest described imprinting regions. Maternal and paternal inheritance of the region is associated with opposite phenotypes affecting growth, development and behaviour. Mis-expression of proteins determined by the imprinted Gnas locus can account for the phenotypes. The imprinting domain in mouse distal chromosome 2 is small, comprising the Gnas locus. This locus is unusually complex, containing biallelic, maternally and paternally expressed transcripts that share exons. It also contains two germline differentially methylated regions that have the characteristics of imprinting control regions. One of these specifically controls the tissue-specific imprinting of the Gnas exon 1 transcript but does not affect the imprinting of other transcripts. Imprinting of other transcripts may be controlled by the other germline differentially methylated region by a mechanism involving antisense RNA.