Scalable Cold-Atom Quantum Simulator for Two-Dimensional QED.

We propose a scalable analog quantum simulator for quantum electrodynamics in two spatial dimensions. The setup for the U(1) lattice gauge field theory employs interspecies spin-changing collisions in an ultracold atomic mixture trapped in an optical lattice. We engineer spatial plaquette terms for magnetic fields, thus solving a major obstacle toward experimental realizations of realistic gauge theories in higher dimensions. We apply our approach to the pure gauge theory of compact QED and discuss how the phenomenon of confinement of electric charges can be described by the quantum simulator.

Dynamical Topological Transitions in the Massive Schwinger Model with a θ Term.

Aiming at a better understanding of anomalous and topological effects in gauge theories out of equilibrium, we study the real-time dynamics of a prototype model for CP violation, the massive Schwinger model with a θ term. We identify dynamical quantum phase transitions between different topological sectors that appear after sufficiently strong quenches of the θ parameter. Moreover, we establish a general dynamical topological order parameter, which can be accessed through fermion two-point correlators and, importantly, which can be applied for interacting theories. Enabled by this result, we show that the topological transitions persist beyond the weak-coupling regime. Finally, these effects can be observed with tabletop experiments based on existing cold-atom, superconducting-qubit, and trapped-ion technology. Our Letter thus presents a significant step towards quantum simulating topological and anomalous real-time phenomena relevant to nuclear and high-energy physics.

Electronic structure of single layer 1T-NbSe2: interplay of lattice distortions, non-local exchange, and Mott-Hubbard correlations.

Using ab initio calculations we reveal the nature of the insulating phase recently found experimentally in monolayer 1T-NbSe2. We find soft phonon modes in a large part of the Brillouin zone indicating the strong-coupling nature of a charge-density-wave instability. Structural relaxation of a [Formula: see text] supercell reveals a Star-of-David reconstruction with an energy gain of 60 meV per primitive unit cell. The band structure of the distorted phase exhibits a half-filled flat band which is associated with orbitals that are delocalized over several atoms in each Star of David. By including many-body corrections through a combined GW, hybrid-functional, and DMFT treatment, we find the flat band to split into narrow Hubbard bands. The lowest energy excitation across the gap turns out to be between itinerant Se-p states and the upper Hubbard band, determining the system to be a charge-transfer insulator. Combined hybrid-functional and GW calculations show that long-range interactions shift the Se-p states to lower energies. Thus, a delicate interplay of local and long-range correlations determines the gap nature and its size in this distorted phase of the monolayer 1T-NbSe2.

Relaxation of an Isolated Dipolar-Interacting Rydberg Quantum Spin System.

How do isolated quantum systems approach an equilibrium state? We experimentally and theoretically address this question for a prototypical spin system formed by ultracold atoms prepared in two Rydberg states with different orbital angular momenta. By coupling these states with a resonant microwave driving, we realize a dipolar XY spin-1/2 model in an external field. Starting from a spin-polarized state, we suddenly switch on the external field and monitor the subsequent many-body dynamics. Our key observation is density dependent relaxation of the total magnetization much faster than typical decoherence rates. To determine the processes governing this relaxation, we employ different theoretical approaches that treat quantum effects on initial conditions and dynamical laws separately. This allows us to identify an intrinsically quantum component to the relaxation attributed to primordial quantum fluctuations.

Universal Self-Similar Scaling of Spatial Wilson Loops Out of Equilibrium.

We investigate strongly correlated non-Abelian plasmas out of equilibrium. Based on numerical simulations, we establish a self-similar scaling property for the time evolution of spatial Wilson loops that characterizes a universal state of matter far from equilibrium. Most remarkably, it exhibits a generalized area law which holds for a sufficiently large ratio of spatial area and fractional power of time. Performing calculations also for the perturbative regime at higher momenta, we are able to characterize the full nonthermal scaling properties of SU(2) and SU(3) symmetric plasmas from short to large distance scales in terms of two independent universal exponents and associated scaling functions.

Anomaly-Induced Dynamical Refringence in Strong-Field QED.

We investigate the impact of the Adler-Bell-Jackiw anomaly on the nonequilibrium evolution of strong-field quantum electrodynamics (QED) using real-time lattice gauge theory techniques. For field strengths exceeding the Schwinger limit for pair production, we encounter a highly absorptive medium with anomaly induced dynamical refractive properties. In contrast to earlier expectations based on equilibrium properties, where net anomalous effects vanish because of the trivial vacuum structure, we find that out-of-equilibrium conditions can have dramatic consequences for the presence of quantum currents with distinctive macroscopic signatures. We observe an intriguing tracking behavior, where the system spends longest times near collinear field configurations with maximum anomalous current. Apart from the potential relevance of our findings for future laser experiments, similar phenomena related to the chiral magnetic effect are expected to play an important role for strong QED fields during initial stages of heavy-ion collision experiments.

Universality far from equilibrium: from superfluid Bose gases to heavy-ion collisions.

Isolated quantum systems in extreme conditions can exhibit unusually large occupancies per mode. This overpopulation gives rise to new universality classes of many-body systems far from equilibrium. We present theoretical evidence that important aspects of non-Abelian plasmas in the ultrarelativistic limit admit a dual description in terms of a Bose condensed scalar field theory.

Real-time dynamics of string breaking.

We study the real-time dynamics of string breaking in quantum electrodynamics in one spatial dimension. A two-stage process with a clear separation of time and energy scales for the fermion-antifermion pair creation and subsequent charge separation leading to the screening of external charges is found. Going away from the traditional setup of external static charges, we establish the phenomenon of multiple string breaking by considering dynamical charges flying apart.

New types of metacaspases in phytoplankton reveal diverse origins of cell death proteases.

Metacaspases are evolutionarily distant homologs of caspases that are found outside the metazoan and are known to have key roles in programmed cell death (PCD). Two types of metacaspases (types I and II) have been defined in plants based on their domain structures; these have similarities to metazoan 'initiator' and 'executioner' caspases. However, we know little about metacaspases in unicellular organisms and even less about their roles in cell death. We identified a novel group of metacaspases in sequenced phytoplanktonic protists that show domain architectures distinct from either type I or II enzymes; we designate them as type III. Type III metacaspases exhibit a rearrangement of domain structures between N- and C-terminus. In addition, we found a group of metacaspase-like proteases in phytoplankton that show sequence homology with other metacaspases, but defy classification in conventional schemes. These metacaspase-like proteases exist in bacteria alongside a variant of type I metacaspases and we propose these bacterial metacaspases are the origins of eukaryotic metacaspases. Type II and III metacaspases were not detected in bacteria and they might be variants of bacterial type I metacaspases that evolved in plants and phytoplanktonic protists, respectively, during the establishment of plastids through the primary and secondary endosymbiotic events. A complete absence of metacaspases in protists that lost plastids, such as oömycetes and ciliates indicates the gene loss during the plastid-to-nucleus gene transfer. Taken together, our findings suggest endosymbiotic gene transfer (EGT) is a key mechanism resulting in the evolutionary diversity of cell death proteases.

[Community-acquired urinary tract infections in 15 to 65 years old female patients in France. Susceptibility of E. coli according to history: AFORCOPI-BIO network 2003]. / Infections urinaires communautaires de la femme de 15 à 65 ans: sensibilité aux antibiotiques de E. coli en fonction des antécédents: étude AFORCOPI-BIO 2003.

OBJECTIVES: A multicenter study was implemented in order to determine the distribution and antibiotic susceptibility patterns of strains isolated from 15 to 65 year old female patients with community-acquired urinary tract infections. PATIENTS AND METHODS: From October to December 2003, 11 French private laboratories consecutively collected 420 clinical strains with medical data. Minimal inhibitory concentrations of antibiotics on E. coli were determined using the agar dilution method in a coordinating center and interpretation followed the recommendations of the Comité de l'antibiogramme de la Société française de microbiologie. RESULTS: Escherichia coli was the most prevalent pathogen (80%) followed by Proteus mirabilis (4%), Klebsiella spp (2%), other Enterobacteriaceae (4%), Enterococcus spp (3%), Staphylococcus aureus (2%), Staphylococcus saprophyticus (2%), and Streptococcus agalactiae (2%). The susceptibility of E. coli strains was 61% for amoxicillin (AMX), 93% for nalidixic acid (NAL), 97% for norfloxacin (NOR) and ciprofloxacin (CIP), 77% for cotrimoxazole (SXT), 99% for fosfomycin, gentamicin and cefotaxime. The susceptibility of E. coli was lower in case of previous treatment with beta-lactam antibiotics for AMX (84 vs 95% p=0.02) and SXT (62 vs 81% p=0.02). In the same way, previous treatment with quinolones was associated with decreased susceptibility for NAL (84 vs 95% p=0.02) and SXT (62 vs 81% p=0.02). CONCLUSIONS: In 2003, fluoroquinolones, third generation cephalosporins, aminoglycosides, and fosfomycin kept a good activity on E. coli collected from community-acquired urinary tract infections in 15 to 65 years old female patients in France.

Simulating nonequilibrium quantum fields with stochastic quantization techniques.

We present lattice simulations of nonequilibrium quantum fields in Minkowskian space-time. Starting from a nonthermal initial state, the real-time quantum ensemble in (3 + 1) dimensions is constructed by a stochastic process in an additional (5th) "Langevin-time." For the example of a self-interacting scalar field, we show how to resolve apparent unstable Langevin dynamics and compare our quantum results with those obtained in classical field theory. Such a direct simulation method is crucial for our understanding of collision experiments of heavy nuclei or other nonequilibrium phenomena in strongly coupled quantum many-body systems.

[Alpha 2 macroglobulin immunoturbidimetric assays (DakoCytomation reagents) on Roche Diagnostic analysers (Modular P, Cobas Integra). Application to FibroTest-Actic-Test]. / Dosage immunoturbidimétrique de l'alpha 2 macroglobuline (réactifs DakoCytomation) sur les automates Roche Diagnostics (Modular P, Cobas Intégra). Application au FibroTest-ActiTest).

BACKGROUND: Alpha2Macroglobulin (A2M) measure showed a revival since it was introduced into FibroTest-ActiTest-Fibro (FT-AT-Fibro) algorithm. More often than not, this assay is performed in immunonephelemetry. Progresses in the comprehension of fibrosis dynamics and better treatment efficacy follow-up will increase FT-AT-Fibro prescriptions. Despite efforts to standardize methods of enzymatic activity measure and proteins measure, we still observe important interlaboratory and intersystem variability. AIM: The primary aim of the study is to validate immunoturbidimetric measure of A2M on Modular P and Cobas Integra analysers (Roche Diagnostics) in utility channel using DakoCytomation reagents in order to extend the analytical system range allowed to measure A2M. The secondary aim of the study is to verify transferability of the six FT-AT composants (A2M, haptoglobin, apolipoprotein A1, total bilirubin, GGT and ALT) to Roche Diagnostics equipment by comparing with results measured on the reference system. RESULTS: A2M measures (n = 146) showed linearity, repetitiveness and were reproducible. Readjustments to adapt A2M measures were required. A corrector factor of 0.84 for Modular P and of 0.87 for Cobas Integra was introduced in order to readjust the immunoturbidimetric method to the immunonephelemetric method. The rationale of proposed corrector factors is based on the use of Dade Behring and DakoCytomation reagents (antisera and calibrant). Biologist vigilance is required to point out modifications or variations in reagents that could be done by the company. The six parameters results transferability from the reference system to Roche Diagnostics was demonstrated by statistic analysis. FT-AT showed excellent correlations to the reference system for Modular P and Cobas Integra analysers. In this study no difference more than 0.11 was recorded and only few subjects had differences between 0.05 and 0.10. Therefore this very low inter-analysers variability has no significant clinical impact. CONCLUSION: This study showed that the analytical system made of Modular P, Cobas Integra, Roche Diagnostics and DakoCytomation reagents can be used for FibroTest-ActiTest-Fibro parameters assessment. Their statistical and clinical variability were acceptable compared to the reference system.

[Genital infections in women, in community practice. Comparison of two studies, 1987 and 2002]. / Les infections génitales chez la femme en pratique de ville Enquêtes Aforcopi-BIO. Comparaison des résultats 1987 et 2002.

One thousand eight hundred and thirty-six clinical and biological cervico-vaginal flora samples from genital infections in women observed in community practice in 1987 were compared to 368 samples collected in 2001. The diagnosis of sexually transmitted infection (STI) was rarely made. Nonetheless, examining these samples made it possible either to prescribe a specific treatment for a confirmed infection (chlamydia, trichonomiasis, candidiasis, gonococci, vaginosis), or to modify a long-term treatment that was often ineffective and sometimes badly tolerated. Not all vulvar itching, associated or not with pelvic pain, is caused by mycosis. Treatment based on a syndromic approach was often ineffective, because clinical symptoms, whether isolated or associated, even when they were suggestive of an etiology, presented only a minor positive predictive value (the PPV for the association ichting + pelvic pain was only 10% for chlamydia, but 45% for candidiasis). The diagnosis of vaginosis, suggested for the past 10 years as an improvement in the diagnosis of vulvo-vaginitis, was made in only 13% of the cases. The only significant difference in our two studies was a lower number of cases of gonococci, chlamydiae, and ureaplasms in 2001, the settings having remained identical, except for a lower number of patients in 2001.

Prethermalization.

Prethermalization of the equation of state and the kinetic temperature to their equilibrium values occurs on time scales dramatically shorter than the thermal equilibration time. This is a crucial ingredient for the understanding of collisions of heavy nuclei or other nonequilibrium phenomena in complex quantum and classical many body systems. We also compare the chemical equilibration time with other characteristic time scales.

Determining parameters of the numerical response.

The numerical response, the change in specific growth rate with food concentration, is a fundamental component of many aquatic microbial studies. Accurately and precisely determining the parameters of this response is essential to obtain useful data for both aut- and synec-ological studies. In this work we emphasize four points that are often ignored in designing numerical response experiments: (1) the inclusion of subthreshold concentrations (i.e., where growth rate is negative) in the experimental design; (2) an appropriate allocation of effort, i.e., the superiority of choosing more individual prey concentrations rather than replicating fewer; (3) the potential superiority of replicating experiments rather than simply replicating treatment in a single experiment; and (4) the placement of most measurements near the lower end of the concentration gradient, well below the asymptote, possibly following a geometric progression. We illustrate the first point by examining a small subset of published data on planktonic oligotrich ciliates and then, using a Monte Carlo simulation, rigorously evaluate the experimental design, supporting the remaining points.

Gapless color superconductivity

We present the dispersion relations for quasiparticle excitations about the color-flavor locked ground state of QCD at high baryon density. In the presence of condensates which pair light and strange quarks there need not be an energy gap in the quasiparticle spectrum. This raises the possibility of gapless color superconductivity, with a Meissner effect but no minimum excitation energy. Analysis within a toy model suggests that gapless color superconductivity may occur only as a metastable phase.

O-H small middle dot small middle dot small middle dotPt(II): Hydrogen Bond with a Strong Dispersion Component.

An MP2 ab initio study of the interaction between a H(2)O molecule and trans-[Pt(OH)(2)(NH(3))(2)] revealed a HO-H small middle dot small middle dot small middle dotPt(II) hydrogen bond (see picture) with a strong dispersion component (ca. 4 kcal mol(-1)). This dispersion interaction is independent of the charge on the complex and is likely to be ubiquitous in aqueous solutions of Pt(II) complexes.

[Urinary tract infection in an urban population: etiology and antibiotic sensitivity as a function of patient history]. / Infections urinaires en pratique de ville: étiologies et sensibilité aux antibiotiques en fonction des antécédents. l'AFORCOPI-BIO. Association pour la Formation Continue en Pathologie Infectieuse des Biologistes.

OBJECTIVE: The aim of this study was to explore the relationship between etiological factors, bacterial isolates and Escherichia coli susceptibility to antibiotics in ambulatory patients with urinary tract infection. PATIENTS AND METHODS: A prospective study was conducted in 13 private medical laboratories in France in March 1998. Data were collected on 658 cases involving 679 strains in ambulatory patients with urinary tract infections. Data on age, gender, catheter insertion within the 7 preceding days, and history of hospitalization, urinary infection and antibiotic treatment during the 6 preceding months were recorded. The distribution of the bacterial isolates and Eschericha coli sensitivity to ciprofloxacin, cotrimoxazole, and gentamycin were studied. RESULTS: E. coli was most frequently isolated in women, in patients with no catheter or without a history of antibiotic treatment, hospitalization or urinary infection. There was no difference in E. coli sensitivity according to sex and age in women. In patients with prior antibiotic treatment, all the tested antibiotics except gentamycin were significantly less active. In case of prior hospitalization, the E. coli isolates were more resistant to amoxicillin, quinolones, cotrimoxazole and gentamycin. The level of E. coli suceptibility rose as the delay since hospitalization or urinary infection increased. CONCLUSION: Ambulatory patients comprise a heterogeneous population requiring particular attention to correctly adapt therapeutic strategies.

Anchorage-dependent transcription of the cyclin A gene.

NIH 3T3 cells cultured in suspension fail to express cyclin A and hence cannot enter S phase and divide. We show that loss of cell adhesion to substratum abrogates cyclin A gene expression by blocking its promoter activity through the E2F site that mediates its cell cycle regulation in adherent cells. In suspended cells, G0-specific E2F complexes remain bound to the cyclin A promoter. Overexpression of cyclin D1 restores cyclin A transcription in suspended cells and rescues them from cell cycle arrest. In suspended cells, cyclin D1 and cyclin E accumulate normally upon serum stimulation, but their associated kinases remain inactive; their substrates, pRb and p107, are not hyperphosphorylated. Concomitantly, the cyclin-dependent kinase inhibitor, p27KIP1, is stabilized. Ectopic expression of p27KIP1 blocks cyclin A promoter activity through its EN binding site. These data suggest that the block to cyclin A transcription in nonadherent NIH 3T3 cells results from stabilization of p27KIP1 and subsequent inactivation of the specific E2F moiety required for its induction.