Domain wall structure in magnetic bilayers with perpendicular anisotropy

We study the magnetic domain wall structure in magnetic bilayers (two ultrathin ferromagnetic layers separated by a non magnetic spacer) with perpendicular magnetization. Combining magnetic force and ballistic electron emission microscopies, we are able to reveal the details of the magnetic structure of the wall with a high spatial accuracy. In these layers, we show that the classical Bloch wall observed in single layers transforms into superposed N\'eel walls due to the magnetic coupling between the ferromagnetic layers. Quantitative agreement with micromagnetic calculations is achieved.Comment: Author adresses AB, SR, JM and AT: Laboratoire de Physique des Solides, CNRS, Universit\'e Paris Sud, UMR 8502, 91405 Orsay Cedex, France ML : Laboratoire PMTM, Institut Galil\'ee, CNRS, Universit\'e Paris-13, UPR 9001, 93430 Villetaneuse, Franc

The essential role of surface pinning in the dynamics of charge density waves submitted to external dc fields

A Charge Density Wave (CDW) submitted to an electric field displays a strong shear deformation because of pinning at the lateral surfaces of the sample. This CDW transverse pinning was recently observed but has received little attention from a theoretical point of view until now despite important consequences on electrical conductivity properties. Here, we provide a description of this phenomenon by considering a CDW submitted to an external dc electric field and constrained by boundary conditions including both longitudinal pinning due to electrical contacts and transverse surface pinning. A simple formula for the CDW phase is obtained in 3D by using the Green function and image charges method. In addition, an analytical expression of the threshold field dependence on both length and sample cross section is obtained by considering the phase slip process. We show that the experimental data are well reproduced with this model and that bulk pinning can be neglected. This study shows that the dynamical properties of CDW systems could be mainly driven by boundary effects, despite the comparatively huge sample volumes.Comment: 7 pages of main text, 7 pages of appendices 15 figure

First isolation of a rhabdovirus from perch Perca fluviatilis in Switzerland

Perca fluviatilis is a fish species of increasing interest to the Swiss fish farming industry. In recent years, recirculation systems have been specifically set up to increase production. In one of these farms, abnormal spiral swimming associated with elevated mortalities occurred in repeated batches of imported perch shortly after stocking on several occasions. No bacterial or parasitic etiology was detected, but a virus grown in bluegill fry (BF-2) cells was identified as perch rhabdovirus. Subsequent investigations of other samples suggested a viral tropism for the central nervous system (CNS). Phylogenetic analysis of the partial N and entire G gene sequences positioned this isolate in genogroup C of the species Perch rhabdovirus, with high nucleotide and amino acid (aa) sequence identities with the DK5533 strain isolated in Denmark in 1989. Comparative studies using other closely related isolates allowed the distinction of 2 serological Patterns among perch rhabdoviruses and the identification of a proline substitution by a serine in Position 147 of the glycoprotein potentially involved in antigenic differentiation. Even if perch imported onto the farm tested negative by virus isolation prior to transport, they may have been the origin of this outbreak since CNS tissue was not included in the samples that were analyzed. Another possibility might be a sub-clinical infection with a viral load in resident fish too low to be detected. This study reports the first isolation of a perch rhabdovirus in Switzerland, and emphasizes the necessity of optimizing diagnostic tools that facilitate better control of the risks associated with fish translocation

Component-based programming for higher-order attribute grammars

This paper presents techniques for a component-based style of programming in the context of higher-oder attribute grammars (HAG). Attribute grammar components are "plugged in" into larger attribute grammar systems through higher-order attribute grammars. Higher-order attributes are used as (intermediate) "gluing" data structures.This paper also presents two attribute grammar components that can be re-used across different language-based tool specifications: a visualizer and animator of programs and a graphical user interface AG component. Both components are reused in the definition of a simple language processor. The techniques presented in this paper are implemented in LRC: a purely functional, higher-order attribute grammar-based system that generates language-based tools.(undefined

Charge-Density-Waves Tuned by Crystal Symmetry

The electronic orders appearing in condensed matter systems are originating from the precise arrangement of atoms constituting the crystal as well as their nature. This teneous relationship can lead to highly different phases in condensed matter, and drive electronic phase transitions. Here, we show that a very slight deformation of the crystal structure of TbTe$_3$ can have a dramatic influence on the electronic order that is stabilized. In particular, we show that the Charge Density Wave (CDW) developping along the $\vec{c}$ axis in the pristine state, switches to an orientation along $\vec{a}$ when the naturally orthorhombic system is turned into a tetragonal system. This is achieved by performing true biaxial mechanical deformation of a TbTe$_3$ sample from 250K to 375K, and by measuring both structural and electronic parameters with x-ray diffraction and transport measurements. We show that this switching transition is driven by the tetragonality parameter $a/c$, and that the transition occurs for $a=c$, with a coexistence region for $0.9985< a/c < 1.002$. The CDW transition temperature $T_c$ is found to have a linear dependence with $a/c$, with no saturation in the deformed states investigated here, while the gap saturates out of the coexistence region. The linear dependence of $T_c$ is accounted for within a tight-binding model. Our results question the relationship between the gap and $T_c$ in RTe$_3$ systems. More generally, our method of applying true biaxial deformation at cryogenic temperatures can be applied to many systems displaying electronic phase transitions, and opens a new route towards the study of coexisting or competing electronic orders in condensed matter

Childhood leukaemia and population movements in France, 1990–2003

In a national study, we investigated the incidence of childhood leukaemia (CL) over a 14-year period in France in relation to several measures based on the proportion of individuals who changed address between the last two national censuses. A positive association was found with the proportion of migrants who came from a distant place. The further the migrants came, the higher was the incidence of leukaemia, particularly among children aged 0–4 years in ‘isolated' communes at the time of diagnosis (RR=1.4, 95% CI: 1.1,1.8 in the highest category of migration distance). Although the role of the population density was less obvious, a more marked association was found above a certain threshold. No association with the proportion of commuters was observed

Artificial graphene as a tunable Dirac material

Artificial honeycomb lattices offer a tunable platform to study massless Dirac quasiparticles and their topological and correlated phases. Here we review recent progress in the design and fabrication of such synthetic structures focusing on nanopatterning of two-dimensional electron gases in semiconductors, molecule-by-molecule assembly by scanning probe methods, and optical trapping of ultracold atoms in crystals of light. We also discuss photonic crystals with Dirac cone dispersion and topologically protected edge states. We emphasize how the interplay between single-particle band structure engineering and cooperative effects leads to spectacular manifestations in tunneling and optical spectroscopies.Comment: Review article, 14 pages, 5 figures, 112 Reference

Sleep and its association with aggression among prisoners: Quantity or quality?

Objective: The current paper aims to examine the association between self-reported sleep quality and quantity and how these relate to aggression motivation and hostile cognition in a male prisoner sample. The cognitive component of sleep, namely perception, is consequently a variable of particular interest and one neglected by previous research. Methods: Two independent studies are presented. The first comprised 95 adult male prisoners who completed a sleep quality index along with measures of implicit and explicit aggression. The second study extended this to consider aggression motivation and hostile attribution biases using a sample of 141 young male adult prisoners. Results: In study one, sleep quantity and indicators of sleep quality were found not to associate with aggression whereas the perception of poor sleep did; those perceiving poor sleep quality were more likely than those perceiving good sleep to report they had perpetrated aggression in the previous week and to report higher levels of implicit aggression. Study two found that while increased indicators of poor sleep quality were associated with lower prosocial attribution tendencies and higher levels of reactive and proactive aggression, sleep quantity was not associated. The perception of poor quality sleep was important; those perceiving poor sleep were more likely to report higher levels of reactive and proactive aggression than those reporting good sleep. Conclusions: Collectively the studies highlight the importance of accounting for the perception of sleep quality as an important cognitive component in understanding the association between sleep and aggression

New Trends in Beverage Packaging Systems: A Review

New trends in beverage packaging are focusing on the structure modification of packaging materials and the development of new active and/or intelligent systems, which can interact with the product or its environment, improving the conservation of beverages, such as wine, juice or beer, customer acceptability, and food security. In this paper, the main nutritional and organoleptic degradation processes of beverages, such as oxidative degradation or changes in the aromatic profiles, which influence their color and volatile composition are summarized. Finally, the description of the current situation of beverage packaging materials and new possible, emerging strategies to overcome some of the pending issues are discussed

Enteral versus parenteral early nutrition in ventilated adults with shock: a randomised, controlled, multicentre, open-label, parallel-group study (NUTRIREA-2)

BACKGROUND: Whether the route of early feeding affects outcomes of patients with severe critical illnesses is controversial. We hypothesised that outcomes were better with early first-line enteral nutrition than with early first-line parenteral nutrition. METHODS: In this randomised, controlled, multicentre, open-label, parallel-group study (NUTRIREA-2 trial) done at 44 French intensive-care units (ICUs), adults (18 years or older) receiving invasive mechanical ventilation and vasopressor support for shock were randomly assigned (1:1) to either parenteral nutrition or enteral nutrition, both targeting normocaloric goals (20-25 kcal/kg per day), within 24 h after intubation. Randomisation was stratified by centre using permutation blocks of variable sizes. Given that route of nutrition cannot be masked, blinding of the physicians and nurses was not feasible. Patients receiving parenteral nutrition could be switched to enteral nutrition after at least 72 h in the event of shock resolution (no vasopressor support for 24 consecutive hours and arterial lactate &lt;2 mmol/L). The primary endpoint was mortality on day 28 after randomisation in the intention-to-treat-population. This study is registered with ClinicalTrials.gov, number NCT01802099. FINDINGS: After the second interim analysis, the independent Data Safety and Monitoring Board deemed that completing patient enrolment was unlikely to significantly change the results of the trial and recommended stopping patient recruitment. Between March 22, 2013, and June 30, 2015, 2410 patients were enrolled and randomly assigned; 1202 to the enteral group and 1208 to the parenteral group. By day 28, 443 (37%) of 1202 patients in the enteral group and 422 (35%) of 1208 patients in the parenteral group had died (absolute difference estimate 2·0%; [95% CI -1·9 to 5·8]; p=0·33). Cumulative incidence of patients with ICU-acquired infections did not differ between the enteral group (173 [14%]) and the parenteral group (194 [16%]; hazard ratio [HR] 0·89 [95% CI 0·72-1·09]; p=0·25). Compared with the parenteral group, the enteral group had higher cumulative incidences of patients with vomiting (406 [34%] vs 246 [20%]; HR 1·89 [1·62-2·20]; p&lt;0·0001), diarrhoea (432 [36%] vs 393 [33%]; 1·20 [1·05-1·37]; p=0·009), bowel ischaemia (19 [2%] vs five [&lt;1%]; 3·84 [1·43-10·3]; p=0·007), and acute colonic pseudo-obstruction (11 [1%] vs three [&lt;1%]; 3·7 [1·03-13·2; p=0·04). INTERPRETATION: In critically ill adults with shock, early isocaloric enteral nutrition did not reduce mortality or the risk of secondary infections but was associated with a greater risk of digestive complications compared with early isocaloric parenteral nutrition. FUNDING: La Roche-sur-Yon Departmental Hospital and French Ministry of Health