On perturbations of Dirac operators with variable magnetic field of constant direction

We carry out the spectral analysis of matrix valued perturbations of 3-dimensional Dirac operators with variable magnetic field of constant direction. Under suitable assumptions on the magnetic field and on the pertubations, we obtain a limiting absorption principle, we prove the absence of singular continuous spectrum in certain intervals and state properties of the point spectrum. Various situations, for example when the magnetic field is constant, periodic or diverging at infinity, are covered. The importance of an internal-type operator (a 2-dimensional Dirac operator) is also revealed in our study. The proofs rely on commutator methods.Comment: 12 page

Dupuytren contracture recurrence project: reaching consensus on a definition of recurrence

The aim of this study was to determine a definition of recurrence of Dupuytren disease that could be utilized for the comparison of the results independently from the treatment used. 24 hand surgeons from 17 countries met in an international consensus conference. The participants used the Delphi method to evaluate a series of statements: (1) the need for defining recurrence, (2) the concept of recurrence applied to the Tubiana staging system, (3) the concept of recurrence applied to each single treated joint, and (4) the concept of recurrence applied to the finger ray. For each item, the possible answer was given on a scale of 1-5: 1=maximum disagreement; 2=disagreement; 3=agreement; 4=strong agreement; 5=absolute agreement. There was consensus on disagreement if 1 and 2 comprised at least 66% of the recorded answers and consensus on agreement if 3, 4 and 5 comprised at least 66% of the recorded answers. If a threshold of 66% was not reached, the related statement was considered not defined. A need for a definition of recurrence was established. The presence of nodules or cords without finger contracture was not considered an indication of recurrence. The Tubiana staging system was considered inappropriate for reporting recurrence. Recurrence was best determined by the measurement of a specific joint, rather than a total ray. Time 0 occurred between 6 weeks and 3 months. Recurrence was defined as a PED of more than 20\ub0 for at least one of treated joint, in the presence of a palpable cord, compared to the result obtained at time 0. This study determined the need for a standard definition of recurrence and reached consensus on that definition, which we should become the standard for the reporting of recurrence. If utilized in subsequent publications, this will allow surgeons to compare different techniques and make is easier to help patients make an informed choice.usammenfassung Ziel der Konsensuskonferenz in Rom war es, eine Definition des Rezidivs bei Morbus Dupuytren festzulegen, die fur einen Vergleich der Ergebnisse unabhangig von der gewahlten Behandlung einsetzbar ist. 24 Handchirurgen aus 17 Landern kamen im Rahmen einer internationalen Konsensuskonferenz zusammen. Die Teilnehmer wendeten die Delphi-Methode an, um folgende Thesen zu bewerten: (1) die Notwendigkeit einer Definition des Rezidivs bei Morbus Dupuytren, das Rezidiv soll (2) auf die Stadieneinteilung nach Tubiana, (3) fur jedes einzelne behandelte Gelenk, oder (4) auf den Fingerstrahl angewandt werden. Jede These konnte auf einer Skala von 1 bis 5 bewertet werden: 1=stimme gar nicht zu; 2=stimme nicht zu; 3=stimme zu; 4=stimme sehr zu; 5=stimme vollstandig zu. Keine Zustimmung lag vor, wenn mindestens 66% der erfassten Antworten auf 1 und 2 entfielen und Zustimmung lag vor, falls mindestens 66 % der erfassten Antworten auf 3, 4 und 5 entfielen. Falls der Schwellenwert von 66% nicht erreicht wurde, wurde die jeweilige Aussage als "nicht definiert betrachtet. Die Notwendigkeit einer Definition des Rezidivs bei Morbus Dupuytren wurde mit dieser Methode festgestellt. Das Vorliegen von Knoten oder Sehnen ohne Kontraktur der Finger wurde nicht als Anzeichen eines Rezidivs gewertet. Die Stadieneinteilung nach Tubiana stellte sich als ungeeignet zur Beschreibung eines Rezidivs heraus. Ein Rezidiv bei Morbus Dupuytren ist besser durch die Messung eines spezifischen Gelenks als durch eine Messung der Beugekontraktur des gesamten Fingerstrahls bestimmt. Der Ausgangspunkt Null wurde definiert als Zeitraum zwischen 6 Wochen und 3 Monaten nach der primaren Behandlung. Ein Rezidiv wird dann definiert als eine passive Beugekontraktur von mehr als 20 degrees fur jedes behandelte Gelenk bei Vorliegen eines tastbaren Stranges, verglichen mit dem Ergebnis zum Zeitpunkt Null. Die Konferenz zeigte die Notwendigkeit einer Definition des Rezidivs bei Morbus Dupuytren und fuhrte zu einem Konsens in Bezug auf diese Definition. Bei Verwendung in nachfolgenden Publikationen wird sie es ermoglichen, verschiedene Techniken zu vergleichen und die Patienten beim Treffen einer informierten Entscheidung zu unterstutzen

Essential spectra of difference operators on \sZ^n-periodic graphs

Let (\cX, \rho) be a discrete metric space. We suppose that the group \sZ^n acts freely on $X$ and that the number of orbits of $X$ with respect to this action is finite. Then we call $X$ a \sZ^n-periodic discrete metric space. We examine the Fredholm property and essential spectra of band-dominated operators on $l^p(X)$ where $X$ is a \sZ^n-periodic discrete metric space. Our approach is based on the theory of band-dominated operators on \sZ^n and their limit operators. In case $X$ is the set of vertices of a combinatorial graph, the graph structure defines a Schr\"{o}dinger operator on $l^p(X)$ in a natural way. We illustrate our approach by determining the essential spectra of Schr\"{o}dinger operators with slowly oscillating potential both on zig-zag and on hexagonal graphs, the latter being related to nano-structures

Measuring multipartite entanglement via dynamic susceptibilities

Entanglement plays a central role in our understanding of quantum many body physics, and is fundamental in characterising quantum phases and quantum phase transitions. Developing protocols to detect and quantify entanglement of many-particle quantum states is thus a key challenge for present experiments. Here, we show that the quantum Fisher information, representing a witness for genuinely multipartite entanglement, becomes measurable for thermal ensembles via the dynamic susceptibility, i.e., with resources readily available in present cold atomic gas and condensed-matter experiments. This moreover establishes a fundamental connection between multipartite entanglement and many-body correlations contained in response functions, with profound implications close to quantum phase transitions. There, the quantum Fisher information becomes universal, allowing us to identify strongly entangled phase transitions with a divergent multipartiteness of entanglement. We illustrate our framework using paradigmatic quantum Ising models, and point out potential signatures in optical-lattice experiments.Comment: 5+5 pages, 3+2 figure

Recombination between Polioviruses and Co-Circulating Coxsackie A Viruses: Role in the Emergence of Pathogenic Vaccine-Derived Polioviruses

Ten outbreaks of poliomyelitis caused by pathogenic circulating vaccine-derived polioviruses (cVDPVs) have recently been reported in different regions of the world. Two of these outbreaks occurred in Madagascar. Most cVDPVs were recombinants of mutated poliovaccine strains and other unidentified enteroviruses of species C. We previously reported that a type 2 cVDPV isolated during an outbreak in Madagascar was co-circulating with coxsackieviruses A17 (CA17) and that sequences in the 3′ half of the cVDPV and CA17 genomes were related. The goal of this study was to investigate whether these CA17 isolates can act as recombination partners of poliovirus and subsequently to evaluate the major effects of recombination events on the phenotype of the recombinants. We first cloned the infectious cDNA of a Madagascar CA17 isolate. We then generated recombinant constructs combining the genetic material of this CA17 isolate with that of the type 2 vaccine strain and that of the type 2 cVDPV. Our results showed that poliovirus/CA17 recombinants are viable. The recombinant in which the 3′ half of the vaccine strain genome had been replaced by that of the CA17 genome yielded larger plaques and was less temperature sensitive than its parental strains. The virus in which the 3′ portion of the cVDPV genome was replaced by the 3′ half of the CA17 genome was almost as neurovirulent as the cVDPV in transgenic mice expressing the poliovirus cellular receptor gene. The co-circulation in children and genetic recombination of viruses, differing in their pathogenicity for humans and in certain other biological properties such as receptor usage, can lead to the generation of pathogenic recombinants, thus constituting an interesting model of viral evolution and emergence

The deindustrialisation/tertiarisation hypothesis reconsidered: a subsystem application to the OECD7

The diffusion of outsourcing, both national and international, and vertical FDIs among manufacturing firms, along with the higher integra- tion of business services in manufacturing, has recently led to question the empirical evidence supporting the Deindustrialisation/Tertiarisation (DT) hypothesis. Rather than a \real" phenomenon, it has been argued, DT would be an \apparent" one, mainly due to the reorganization of production across national and sectoral boundaries. The empirical studies that have dealt with the topic so far have not been able to effectively rule out such possibility, because of two main limitations: the sectoral level of the analysis and/or the national focus. In order to overcome them, the paper carries out an appreciative investigation of the actual extent of the DT occurred in the OECD area over the '80s and the '90s by moving from a sector to a subsystem perspective, thus retaining both direct and indirect relations, and by referring to a \pseudo-World" of 7 OECD countries, thus taking into account the \global" dimension of the phenomenon. The results strongly support the DT hypothesis: although the weight of business sector services in the manufacturing subsystem increased, acting as a counterbalancing tendency to the manufacturing decline, subsystem shares significantly decreased, thus confirming DT as a more fundamental trend of modern economies

A inserção do Brasil no mercado mundial de alumínio: incorporando contribuições da Ecologia Política para a Saúde Coletiva

O presente artigo discute a inserção do Brasil no mercado mundial de alumínio a partir dos referenciais teóricos da ecologia política, da economia política do território e da saúde coletiva. A conjuntura contemporânea da economia mundial tem sido pautada pela desregulamentação e liberalização, característicos do ideário neoliberal propalado pelas nações centrais. A maior participação do Brasil nesse mercado tem sido realizada a partir do aumento da produção e exportação de commodities agrárias e metálicas, como o alumínio. Nesse sentido, a partir dos paradigmas da ecologia política, o texto propõe uma análise das consequências socioambientais, assim como sobre novas territorialidades que se produzem e reproduzem dentro de uma lógica econômica que privilegia as nações centrais. Do mesmo modo, procura-se compreender os dilemas da saúde coletiva sob uma perspectiva holística e integradora na qual se articula aos modelos de desenvolvimento econômico. Percebe-se que a produção e exportação de alumínio primário, apesar de apresentar um valor agregado maior, esconde um conjunto difuso de impactos que afetam o ambiente e a saúde coletiva

Effect of Systemic Hypertension With Versus Without Left Ventricular Hypertrophy on the Progression of Atrial Fibrillation (from the Euro Heart Survey).

Hypertension is a risk factor for both progression of atrial fibrillation (AF) and development of AF-related complications, that is major adverse cardiac and cerebrovascular events (MACCE). It is unknown whether left ventricular hypertrophy (LVH) as a consequence of hypertension is also a risk factor for both these end points. We aimed to assess this in low-risk AF patients, also assessing gender-related differences. We included 799 patients from the Euro Heart Survey with nonvalvular AF and a baseline echocardiogram. Patients with and without hypertension were included. End points after 1 year were occurrence of AF progression, that is paroxysmal AF becoming persistent and/or permanent AF, and MACCE. Echocardiographic LVH was present in 33% of 379 hypertensive patients. AF progression after 1 year occurred in 10.2% of 373 patients with rhythm follow-up. In hypertensive patients with LVH, AF progression occurred more frequently as compared with hypertensive patients without LVH (23.3% vs 8.8%, p = 0.011). In hypertensive AF patients, LVH was the most important multivariably adjusted determinant of AF progression on multivariable logistic regression (odds ratio 4.84, 95% confidence interval 1.70 to 13.78, p = 0.003). This effect was only seen in male patients (27.5% vs 5.8%, p = 0.002), while in female hypertensive patients, no differences were found in AF progression rates regarding the presence or absence of LVH (15.2% vs 15.0%, p = 0.999). No differences were seen in MACCE for hypertensive patients with and without LVH. In conclusion, in men with hypertension, LVH is associated with AF progression. This association seems to be absent in hypertensive women