Dual actions for massless, partially-massless and massive gravitons in (A)dS

We provide a unified treatment of electric-magnetic duality, at the action level and with manifest Lorentz invariance, for massive, massless as well as partially-massless gravitons propagating in maximally symmetric spacetimes of any dimension n>3. For massive and massless fields, we complete previous analyses that use parent-action techniques by giving dual descriptions that enable direct counting of physical degrees of freedom in the flat and massless limit. The same treatment is extended to the partially-massless case, where the duality has been previously discussed in covariant form only at the level of the equations of motion. The nature of the dual graviton is therefore clarified for all values of the mass and of the cosmological constant.Comment: 6 pages. A reference adde

Spin-2 twisted duality in (A)dS

Starting from the dual Lagrangians recently obtained for (partially) massless spin-2 fields in the Stueckelberg formulation, we write the equations of motion for (partially) massless gravitons in (A)dS in the form of twisted-duality relations. In both cases, the latter admit a smooth flat limit. In the massless case, this limit reproduces the gravitational twisted-duality relations previously known for Minkowski spacetime. In the partially-massless case, our twisted-duality relations preserve the number of degrees of freedom in the flat limit, in the sense that they split into a decoupled pair of dualities for spin-1 and spin-2 fields. Our results apply to spacetimes of any dimension greater than three. In four dimensions, the twisted-duality relations for partially massless fields that appeared in the literature are recovered by gauging away the Stueckelberg field.Comment: 15 pages. Introductory remarks, clarifications and references adde

calibration and prediction assessment of different ductile damage models on ti6al4v and 17 4ph additive manufactured alloys

Abstract Nowadays, metal additive manufacturing is becoming always more popular, being able to deliver complex shaped high quality products. Though many studies have been conducted on the high cycle fatigue behavior of these materials, yet ductile failure has still not been completely investigated, to identify the failure limits under static complex stress states. In the present study, the calibration of three ductile damage models on two popular additive manufactured alloys was carried out. The selected alloys were Ti6Al4V, processed via Electron Beam Melting, and 17-4PH fabricated with Selective Laser Melting technology; both broadly used in actual industrial applications. For each material a set of samples, was fabricated to perform a thorough static mechanical characterization, involving tensile tests on round smooth bars, notched bars, tests under plane strain conditions and torsion tests. The stress state in the critical points was retrieved relying on FEM simulations, and the data collected via the hybrid experimental-numerical procedure subsequently used to tune the damage models. Specifically, the selected models are the Rice and Tracey, the Modified Mohr-Coulomb by Wierzbicki and the one proposed by Coppola and Cortese. While the former does not take into account the effect of Lode parameter, the latter two consider its influence on fracture onset. A minimization algorithm was used for their calibration, and different optimization strategies were adopted to check the robustness of identified parameters. The resulting strains to fracture as a function of damage parameters were plotted for each formulation. The failure prediction accuracy of all models was assessed and compared to the others

analysis of the micro voids fraction in structural steels and its evolution during plastic deformation until failure

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Pharmacological and non-pharmacological interventions for adults with ADHD: protocol for a systematic review and network meta-analysis.

INTRODUCTION It is unclear how pharmacological and non-pharmacological interventions compare with each other in terms of efficacy and tolerability for core symptoms and additional problems in adults with attention-deficit/hyperactivity disorder (ADHD). We aim to conduct the first network meta-analysis (NMA) comparing pharmacological and non-pharmacological interventions (or their combinations) in adults with ADHD. METHODS AND ANALYSIS We will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement for NMAs. We will search a broad set of electronic databases/registries and contact drug companies and experts in the field to retrieve published and unpublished randomised controlled trials (RCTs) (parallel or cross-over) of medications (either licensed or unlicensed) and any non-pharmacological intervention in adults (≥18 years) with ADHD. Primary outcomes will be: (1) change in severity of ADHD core symptoms, and (2) acceptability (all-cause discontinuation). Secondary outcomes will include tolerability (drop-out due to side effects) and change in the severity of emotional dysregulation, executive dysfunctions and quality of life. The risk of bias in each individual RCT included in the NMA will be assessed using the Cochrane Risk of Bias tool-version 2. We will evaluate the transitivity assumption comparing the distribution of possible effect modifiers across treatment comparisons. We will perform Bayesian NMA for each outcome with random-effects model in OpenBUGS. Pooled estimates of NMA will be obtained using the Markov Chains Monte Carlo method. We will judge the credibility in the evidence derived from the NMA using the CINeMA tool (which includes assessment of publication bias). We will conduct a series of sensitivity analyses to assess the robustness of the findings. ETHICS AND DISSEMINATION As this is the protocol for an aggregate-data level NMA, ethical approval will not be required. Results will be disseminated at national/international conferences and in peer-reviewed journals. PROSPERO REGISTRATION NUMBER CRD42021265576

Coronary tortuosity: normal variant or pathological condition?

HighlightsCoronary tortuosity is a common coronary angiography finding. The aetiology and the clinical significant are not well defined, generally considered a normal variant. We showed a case of marked tortuosity of all coronary arteries associated with myocardial ischemia. </p

Site-specific integration in mammalian cells mediated by a new hybrid baculovirus-adeno-associated virus vector

Baculovirus can transiently transduce primary human and rat hepatocytes, as well as a subset of stable celllines. To prolong transgene expression, we have developed new hybrid vectors which associate key elementsfrom adeno-associated virus (AAV) with the elevated transducing capacity of baculovirus. The hybrid vectorscontain a transgene cassette composed of the !-galactosidase (!-Gal) reporter gene and the hygromycin resistance(Hygr) gene flanked by the AAV inverted terminal repeats (ITRs), which are necessary for AAV replicationand integration in the host genome. Constructs were derived both with and without the AAV rep geneunder the p5 and p19 promoters cloned in different positions with respect to the baculovirus polyheidrinpromoter. A high-titer preparation of baculovirus-AAV (Bac-AAV) chimeric virus containing the ITR–Hygr–!-Gal sequence was obtained with insect cells only when the rep gene was placed in an antisense orientationto the polyheidrin promoter. Infection of 293 cells with Bac-AAV virus expressing the rep gene results in a 10-to 50-fold increase in the number of Hygr stable cell clones. Additionally, rep expression determined the localizationof the transgene cassette in the aavs1 site in approximately 41% of cases as detected by bothSouthern blotting and fluorescent in situ hybridization analysis. Moreover, site-specific integration of the ITRflankedDNA was also detected by PCR amplification of the ITR-aavs1 junction in transduced human fibroblasts.These data indicate that Bac-AAV hybrid vectors can allow permanent, nontoxic gene delivery of DNAconstructs for ex vivo treatment of primary human cells