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

Seguimiento del tratamiento restaurador de primeros molares permanentes con y sin Hipomineralización Molar

La selección y estabilidad a largo plazo de los materiales de restauración en piezas afectadas por Hipomineralización Molar (HM) es en la actualidad un tema de controversia. El objetivo de este estudio fue comparar las necesidades de tratamiento y el estado de las restauraciones realizadas en primeros molares permanentes en pacientes con y sin HM. Diseño retrospectivo sobre las historias clínicas de 153 pacientes que habían recibido atención integral en 2014, en la Clínica de la Cátedra de Odontología Integral Niños (Facultad de Odontología de la Universidad de Buenos Aires) por 3 odontopediatras (Kappa HM 0,94) y que asistieron a las recitaciones periódicas durante un mínimo de 24 meses. Se registraron las necesidades de tratamiento, tipo y longevidad de los mismos en primeros molares (criterios Ryge modificados /USPHS, Kappa 0,78). Se compararon los resultados entre los pacientes con y sin HM. Se utilizó test de Kruskal Wallis para comparar tiempos de seguimiento, test asintótico de comparación de proporciones y se calculó riesgo relativo (RR) para comparar la necesidad de tratamiento. Los tiempos medios de seguimiento de las 595 piezas analizadas resultaron de 61.7±20.1 y 57.5±23.9 meses en los grupos sin HM y con HM respectivamente (p=0.0504). Los porcentajes de piezas que requirieron al menos un tratamiento fueron 7.2% en el grupo sin HM y 27.5% en el grupo con HM. (RR = 3.80, p < 0.001) De las piezas con HM tratadas, el 23.1% requirieron retratamiento, mientras que en el grupo sin HM ninguna pieza lo necesitó. La necesidad de tratamiento fue aproximadamente 4 veces mayor en los molares afectados con HM con más probabilidad de retratamiento.The selection and long-term stability of restorative materials for teeth affected by MolarHypomineralization (MH) are controversial. The aim of this study was to compare need for treatmentand status of restorations performed on first permanent molars in patients with and without MH.Retrospective design based on the clinical records of 153 patients who had received comprehensive carein 2014 at the Clinic of the Children’s Comprehensive Dentistry Department (FOUBA) by 3 pediatricdentists (Kappa MH 0.94), and who attended periodical follow-up visits for at least 24 months. Needfor treatment in first molars, and type and longevity of treatment were recorded (modified Ryge criteria/USPHS, Kappa 0.78). Results were compared between patients with MH and without MH. TheKruskal Wallis test was used to compare follow-up time, the asymptotic test was performed to compareproportions, and relative risk (RR) was calculated to compare need for treatment.Mean follow-up times for the 595 teeth analyzed were 61.7±20.1 months for Group without MH, and57.5±23.9 months for Group with MH (p=0.0504). The percentages of teeth requiring at least onetreatment were 7.2% in Group without MH and 27.5% in Group with MH (RR = 3.80, p < 0.001). Of theteeth treated in Group with MH 23.1% required retreatment, while none of the teeth in Group withoutMH did. The need for treatment was approximately 4 times higher in molars affected with MH, withgreater probability of retreatment.Fil: Biondi, Ana. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Cortese, Silvina Gabriela. Universidad de Buenos Aires. Facultad de Odontología; ArgentinaFil: Babino, Lucía. Universidad de Buenos Aires. Facultad de Odontología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Ortolani, Andrea. Universidad de Buenos Aires. Facultad de Odontología; Argentin

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

n/

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