D\cal D pseudo-bosons in quantum models

We show how some recent models of PT-quantum mechanics perfectly fit into the settings of $\cal D$ pseudo-bosons, as introduced by one of us. Among the others, we also consider a model of non-commutative quantum mechanics, and we show that this model too can be described in terms of $\cal D$ pseudo-bosons.Comment: In press in Physics Letters

Van der Waals and resonance interactions between accelerated atoms in vacuum and the Unruh effect

We discuss different physical effects related to the uniform acceleration of atoms in vacuum, in the framework of quantum electrodynamics. We first investigate the van der Waals/Casimir-Polder dispersion and resonance interactions between two uniformly accelerated atoms in vacuum. We show that the atomic acceleration significantly affects the van der Waals force, yielding a different scaling of the interaction with the interatomic distance and an explicit time dependence of the interaction energy. We argue how these results could allow for an indirect detection of the Unruh effect through dispersion interactions between atoms. We then consider the resonance interaction between two accelerated atoms, prepared in a correlated Bell-type state, and interacting with the electromagnetic field in the vacuum state, separating vacuum fluctuations and radiation reaction contributions, both in the free-space and in the presence of a perfectly reflecting plate. We show that nonthermal effects of acceleration manifest in the resonance interaction, yielding a change of the distance dependence of the resonance interaction energy. This suggests that the equivalence between temperature and acceleration does not apply to all radiative properties of accelerated atoms. To further explore this aspect, we evaluate the resonance interaction between two atoms in non inertial motion in the coaccelerated (Rindler) frame and show that in this case the assumption of an Unruh temperature for the field is not required for a complete equivalence of locally inertial and coaccelerated points of views.Comment: 8 pages, Proceedings of the Eighth International Workshop DICE 2016 Spacetime - Matter - Quantum Mechanic

Detection of vitellogenin in a subpopulation of sea urchin coelomocytes

Sea urchin vitellogenin is a high molecular weight glycoprotein, which is the precursor of the major yolk protein present in the unfertilized egg. Vitellogenin processing into the major yolk protein and its further enzymatic cleavage during sea urchin embryonic development, has been extensively described, and the adhesive properties of the processed molecule have been studied. The function of vitellogenin in the adult, where it has been found in the coelomic fluid of both male and female individuals, is still unknown, although its role on promoting the adhesion of embryonic cells has been shown. In this report we describe the detection of vitellogenin in lysates of whole circulating coelomocytes of both male and female sea urchins of the species Paracentrotus lividus. By metrizoic acid gradients we purified total coelomocytes into six subpopulations that were tested for the occurrence of the molecule using vitellogenin-specific polyclonal antibodies. We detected vitellogenin only in the coelomocyte subpopulation called colorless spherule cells, packed in kidney-shaped granules located around the nucleus. We also showed that coelomocytes respond to stress conditions by discharging vitellogenin into the medium. This result together with previous observations on the adhesive properties of the molecule suggest a role for vitellogenin in the clotting phenomenon occurring after host invasion

Bracket base remnants after orthodontic debonding

Objective: To evaluate whether the debonding procedure leads to restitutio ad integrum of the enamel surface by investigating the presence of enamel within the bracket base remnants after debonding. Materials and Methods: Sixty patients who completed orthodontic treatment with fixed appliances were included. A total of 1068 brackets were microphotographed; the brackets presenting some remnants on the base (n \u200a=\u200a 818) were selected and analyzed with ImageJ software to measure the remnant area. From this population a statistically significant sample (n \u200a=\u200a 100) was observed under a scanning electron microscope to check for the presence of enamel within the remnants. Energy dispersive x-ray spectrometry was also performed to obtain quantitative data. Results: Statistically significant differences in the remnant percentage between arches were observed for incisor and canine brackets (P < .0001 and P \u200a=\u200a .022, respectively). From a morphologic analysis of the scanning electron micrographs the bracket bases were categorized in 3 groups: group A, bases presenting a thin enamel coat (83%); group B, bases showing sizable enamel fragments (7%); group C, bases with no morphologic evidence of enamel presence (10%). Calcium presence was noted on all evaluated brackets under energy dispersive x-ray spectrometry. No significant difference was observed in the Ca/Si ratio between group A (16.21%) and group B (18.77%), whereas the Ca/Si ratio in group C (5.40%) was significantly lower than that of the other groups (P < .323 and P \u200a=\u200a .0001, respectively). Conclusion: The objective of an atraumatic debonding is not achieved yet; in some cases the damage could be clinically relevant

A transparent distributed ledger-based certificate revocation scheme for VANETs

The widespread adoption of Cooperative, Connected, and Automated Mobility (CCAM) applications requires the implementation of stringent security mechanisms to minimize the surface of cyber attacks. Authentication is an effective process for validating user identity in vehicular networks. However, authentication alone is not enough to prevent dangerous attack situations. Existing security mechanisms are not able to promptly revoke the credentials of misbehaving vehicles, thus tolerate malicious actors to remain trusted in the system for a long time. The resulting vulnerability window allows the implementation of complex attacks, thus posing a substantial impairment to the security of the vehicular ecosystem. In this paper we propose a Distributed Ledger-based Vehicular Revocation Scheme that improves the state of the art by providing a vulnerability window lower than 1 s, reducing well-behaved vehicles exposure to sophisticated and potentially dangerous attacks. The proposed scheme harnesses the advantages of the underlying Distributed Ledger Technology (DLT) to implement a privacy-aware revocation process while being fully transparent to all participating entities. Furthermore, it meets the critical message processing times defined by EU and US standards, thus closing a critical gap in the current international standards. Theoretical analysis and experimental validation demonstrate the effectiveness and efficiency of the proposed scheme, where DLT streamlines the revocation operation overhead and delivers an economically viable yet scalable solution against cyber attacks on vehicular systems

SUBCLINICAL RENAL DAMAGE IS ASSOCIATED WITH A REDUCED CHOROIDAL THICKNESS IN PATIENTS WITH PRIMARY HYPERTENSION

Objective: The retina is considered the easiest accessible window to study the state of the systemic microcirculation, even if the choroid is the most important vascular layer of the eye. Our understanding of the choroid has been greatly increased in last years since the introduction of advanced techniques of optical coherence tomography (OCT). Our study was aimed to assess choroidal thickness by using Swept-Source OCT (SS-OCT) in essential hypertensive patients (EHs) with and without subclinical renal damage (SRD). Design and method: We enrolled 100 EHs of which 65 without kidney damage and 35 with SRD. In all the participants SS-OCT and a routine biochemical work-up were performed. Glomerular filtration rate (GFR) was estimated by the CKD-EPI equation (eGFR). SRD was defined, by the presence of microalbuminuria or eGFR between 30 and 60\u200amL/min/1.73 m2. OCT measurements were performed according to the Early Treatment Diabetic Retinopathy Study (ETDRS) protocol, that divides the macula into 9 subfields. The circular grid consists of 3 concentric rings. The inner and outer rings are further divided into quadrants: temporal, nasal, superior, and inferior. Design and method: Furthermore, we calculated the average of the individuals values of the four quadrants separately for the inner and the outer ring. The average of all the 9 regions of the ETRDS grid (including the inner, the outer and the central rings) was also calculated. Results: EHs with SRD showed thinner choroidal thicknesses than those without kidney damage (all p\u200a<\u200a0.05), even after adjustment for age (figure). Overall choroidal thickness correlated significantly and directly with eGFR (r\u200a=\u200a0.36) and negatively with urinary albumin excretion (r\u200a=\u200a- 0.39). The association of choroidal thickness with SRD was confirmed in multiple logistic regression analyses once the effect of age, anti-hypertensive therapy and triglycerides was accounted for. The odds ratio of having SRD associated with a standard deviation increase of overall choroidal thickness was 0.43 (0.24\u20130.75, 95% confidence interval; p\u200a=\u200a0.007). Conclusions: Our study confirms the close relationships between changes in ocular microcirculation and renal dysfunction

Strength in diversity: enhancing learning in vocationally-orientated, master's level courses

Postgraduate education in geography, especially at the Master’s level, is undergoing significant changes in the developed world. There is an expansion of vocationally-oriented degree programmes, increasing recruitment of international students, integration of work place skills, and the engagement of non-traditional postgraduate students as departments respond to policies for a more ‘inclusive’ higher education. This paper sets the context by outlining some programmatic changes in selected countries (Australia, the UK, and the USA). We briefly reflect on how postgraduate ‘bars’ or ‘levels’ are defined and explore in detail what ‘diversity’ or ‘heterogeneity’ means in these new postgraduate settings. The paper then explores some examples of practice drawn from our own experiences, whilst recognising that relevance will vary in other contexts. Finally we consider how diversity can be harnessed as a strength that has potential to enhance taught elements of contemporary postgraduate education in and beyond the discipline

Cuando la ciencia sale a la comunidad: ofrece sus saberes y construye conocimientos para modificar realidades cotidianas

Cuando la ciencia sale a la comunidad: ofrece sus saberes y construye conocimientos para modificar realidades cotidianasFil: Ferreras, Laura. Universidad Nacional de Rosario. Facultad de Ciencias Agrarias; Argentin

Multi-particle azimuthal correlations in p-Pb and Pb-Pb collisions at the CERN Large Hadron Collider

Measurements of multi-particle azimuthal correlations (cumulants) for charged particles in p-Pb and Pb-Pb collisions are presented. They help address the question of whether there is evidence for global, flow-like, azimuthal correlations in the p-Pb system. Comparisons are made to measurements from the larger Pb-Pb system, where such evidence is established. In particular, the second harmonic two-particle cumulants are found to decrease with multiplicity, characteristic of a dominance of few-particle correlations in p-Pb collisions. However, when a $|\Delta \eta|$ gap is placed to suppress such correlations, the two-particle cumulants begin to rise at high-multiplicity, indicating the presence of global azimuthal correlations. The Pb-Pb values are higher than the p-Pb values at similar multiplicities. In both systems, the second harmonic four-particle cumulants exhibit a transition from positive to negative values when the multiplicity increases. The negative values allow for a measurement of $v_{2}\{4\}$ to be made, which is found to be higher in Pb-Pb collisions at similar multiplicities. The second harmonic six-particle cumulants are also found to be higher in Pb-Pb collisions. In Pb-Pb collisions, we generally find $v_{2}\{4\} \simeq v_{2}\{6\}\neq 0$ which is indicative of a Bessel-Gaussian function for the $v_{2}$ distribution. For very high-multiplicity Pb-Pb collisions, we observe that the four- and six-particle cumulants become consistent with 0. Finally, third harmonic two-particle cumulants in p-Pb and Pb-Pb are measured. These are found to be similar for overlapping multiplicities, when a $|\Delta\eta| > 1.4$ gap is placed.Comment: 25 pages, 11 captioned figures, 3 tables, authors from page 20, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/87