The natural evolution of endoscopic approaches in skull base surgery: robotic-assisted surgery?

The current surgical trend is to expand the variety of minimally invasive approaches and, in particular, the possible applications of robotic systems in head and neck surgery. This is particularly intriguing in skull base regions. In this paper, we review the current literature and propose personal considerations on the role of robotic techniques in this field. A brief description of our personal preclinical experience on skull base robotic dissection represents the basis for further considerations. We are convinced that the advantages of robotic surgery applied to the posterior cranial fossa are similar to those already clinically experienced in other areas (oropharynx, tongue base), in terms of tremor-free, bimanual, precise dissection: the implementation of instruments for bony work and resolving current drawbacks will definitely increase the applicability of such a system in forthcoming years

Nonparametric Bayesian Mixed-effect Model: a Sparse Gaussian Process Approach

Multi-task learning models using Gaussian processes (GP) have been developed and successfully applied in various applications. The main difficulty with this approach is the computational cost of inference using the union of examples from all tasks. Therefore sparse solutions, that avoid using the entire data directly and instead use a set of informative "representatives" are desirable. The paper investigates this problem for the grouped mixed-effect GP model where each individual response is given by a fixed-effect, taken from one of a set of unknown groups, plus a random individual effect function that captures variations among individuals. Such models have been widely used in previous work but no sparse solutions have been developed. The paper presents the first sparse solution for such problems, showing how the sparse approximation can be obtained by maximizing a variational lower bound on the marginal likelihood, generalizing ideas from single-task Gaussian processes to handle the mixed-effect model as well as grouping. Experiments using artificial and real data validate the approach showing that it can recover the performance of inference with the full sample, that it outperforms baseline methods, and that it outperforms state of the art sparse solutions for other multi-task GP formulations.Comment: Preliminary version appeared in ECML201

NNLO QCD×EW corrections to Z production in the q q channel

We present the first results for the O(ααs) corrections to the total partonic cross section of the process qq→Z+X, with the complete set of contributions, that include photonic and massive weak gauge boson effects. The results are relevant for the precise determination of the hadronic Z boson production cross section. Virtual and real corrections are calculated analytically using the reduction to the master integrals and their evaluation through differential equations. Real corrections are dealt with using the reverse-unitarity method. They require the evaluation of a new set of two-loop master integrals, with up to three internal massive lines. In particular, three of them are expressed in terms of elliptic integrals. We verify the absence, at this perturbative order, of initial-state mass singularities proportional to a weak massive virtual correction to the quark-gluon splitting

Noncommutative Electrodynamics

In this paper we define a causal Lorentz covariant noncommutative (NC) classical Electrodynamics. We obtain an explicit realization of the NC theory by solving perturbatively the Seiberg-Witten map. The action is polynomial in the field strenght $F$, allowing to preserve both causality and Lorentz covariance. The general structure of the Lagrangian is studied, to all orders in the perturbative expansion in the NC parameter $\theta$. We show that monochromatic plane waves are solutions of the equations of motion to all orders. An iterative method has been developed to solve the equations of motion and has been applied to the study of the corrections to the superposition law and to the Coulomb law.Comment: 13 pages, 2 figures, one reference adde

Risk factors for obstructive sleep apnea syndrome in children: state of the art

The obstructive sleep apnea syndrome (OSAS) represents only part of a large group of pathologies of variable entity called respiratory sleep disorders (RSD) which include simple snoring and increased upper airway resistance syndrome (UARS). Although the etiopathogenesis of adult OSAS is well known, many aspects of this syndrome in children are still debated. Its prevalence is about 2% in children from 2 to 8 years of age, mostly related to the size of the upper airways adenoid tissue. Several risk factors linked to the development of OSAS are typical of the pediatric age. The object of this paper is to analyze the state of the art on this specific topic, discussing its implications in terms of diagnosis and management

GPU-based Real-time Triggering in the NA62 Experiment

Over the last few years the GPGPU (General-Purpose computing on Graphics Processing Units) paradigm represented a remarkable development in the world of computing. Computing for High-Energy Physics is no exception: several works have demonstrated the effectiveness of the integration of GPU-based systems in high level trigger of different experiments. On the other hand the use of GPUs in the low level trigger systems, characterized by stringent real-time constraints, such as tight time budget and high throughput, poses several challenges. In this paper we focus on the low level trigger in the CERN NA62 experiment, investigating the use of real-time computing on GPUs in this synchronous system. Our approach aimed at harvesting the GPU computing power to build in real-time refined physics-related trigger primitives for the RICH detector, as the the knowledge of Cerenkov rings parameters allows to build stringent conditions for data selection at trigger level. Latencies of all components of the trigger chain have been analyzed, pointing out that networking is the most critical one. To keep the latency of data transfer task under control, we devised NaNet, an FPGA-based PCIe Network Interface Card (NIC) with GPUDirect capabilities. For the processing task, we developed specific multiple ring trigger algorithms to leverage the parallel architecture of GPUs and increase the processing throughput to keep up with the high event rate. Results obtained during the first months of 2016 NA62 run are presented and discussed

Facial nerve dehiscence and cholesteatoma: a comparison between decades

OBJECTIVES: To evaluate the incidence of facial canal dehiscence (FCD) and other intraoperative findings over the last 20 years as well as correlation with the Japanese Otological Society/European Academy of Otology and Neurotology classification in patients with cholesteatoma. MATERIALS and METHODS: A total of 469 patients operated from 1998 to 2018 were selected and divided into 2 groups of 10 years each. RESULTS: Dehiscence was significantly higher in patients with a history of pathology longer than 5 years (22.7%). Higher values were observed in revision surgery, 44.4% in the first period and 41.7% in the second. The tympanic segment was the one most frequently involved, affecting 92% of patients in the first period and 97% of patients in the second. Dehiscence occurred significantly more often in patients with a semicircular canal fistula, 14.8% in the first decade and 8.8% in the second. The incidence of FCD was significantly higher in patients with primary cholesteatoma (especially in those with combined pars tensa-flaccida) than in those with a secondary acquired one, 31.5% vs 7.4% in the first period, 21.1% vs 7.4% in the second, and in those with a stage III disease, 42% in the first period, 33.3% in the second. CONCLUSION: Patients with a shorter history of cholesteatoma as well as those not previously operated had a lower incidence of FCD. The tym-panic tract of the facial nerve remains the most frequent site of dehiscence, while the association between dehiscence and fistula of the semicircular canal remains strong. Patients with combined pars tensa-pars flaccida and stage III cholesteatoma have a higher incidence of FCD

Analytic Results for Virtual QCD Corrections to Higgs Production and Decay

We consider the production of a Higgs boson via gluon-fusion and its decay into two photons. We compute the NLO virtual QCD corrections to these processes in a general framework in which the coupling of the Higgs boson to the external particles is mediated by a colored fermion and a colored scalar. We present compact analytic results for these two-loop corrections that are expressed in terms of Harmonic Polylogarithms. The expansion of these corrections in the low and high Higgs mass regimes, as well as the expression of the new Master Integrals which appear in the reduction of the two-loop amplitudes, are also provided. For the fermionic contribution, we provide an independent check of the results already present in the literature concerning the Higgs boson and the production and decay of a pseudoscalar particle.Comment: 19 pages, 3 figures, version accepted by JHE

Scalar Particle Contribution to Higgs Production via Gluon Fusion at NLO

We consider the gluon fusion production cross section of a scalar Higgs boson in models where fermion and scalar massive colored particles are present. We report analytic expressions for the matrix elements of $gg\to Hg$, $q\bar{q}\to Hg$, and $qg\to Hq$ processes completing the calculation of the NLO QCD corrections in these extended scenarios. The formulas are written in a complete general case, allowing a flexible use for different theoretical models. Applications of our results to two different models are presented: i) a model in which the SM Higgs sector is augmented by a weak doublet scalar in the $SU(N_c)$ adjoint representation. ii) The MSSM, in the limit of neglecting the gluino contribution to the cross section.Comment: 20 pages, 5 figures. Minor changes. Refs. adde

Radiographers and COVID-19 pneumonia: diagnostic performance using CO-RADS

Introduction: A more structured role of radiographers is advisable to speed up the management of patients with suspected COVID-19. The purpose of our study was to evaluate the diagnostic performance of radiographers in the detection of COVID-19 pneumonia on chest CT using CO-RADS descriptors. Methods: CT images of patients who underwent RT-PCR and chest CT due to COVID-19 suspicion between March and July 2020 were analysed retrospectively. Six readers, including two radiologists, two highly experienced radiographers and two less experienced radiographers, independently scored each CT using the CO-RADS lexicon. ROC curves were used to investigate diagnostic accuracy, and Fleiss’κ statistics to evaluate inter-rater agreement. Results: 714 patients (419 men; 295 women; mean age: 64 years ±19SD) were evaluated. CO-RADS> 3 was identified as optimal diagnostic threshold. Highly experienced radiographers achieved an average sensitivity of 58.7% (95%CI: 52.5–64.7), an average specificity of 81.8% (95%CI: 77.9–85.2), and a mean AUC of 0.72 (95%CI: 0.68–0.75). Among less experienced radiographers, an average sensitivity of 56.3% (95%CI: 50.1–62.2) and an average specificity of 81.5% (95%CI: 77.6–84.9) were observed, with a mean AUC of 0.71 (95%CI: 0.68–0.74). Consultant radiologists achieved an average sensitivity of 60.0% (95%CI: 53.7–65.8), an average specificity of 81.7% (95%CI: 77.8–85.1), and a mean AUC of 0.73 (95%CI: 0.70–0.77). Conclusion: Radiographers can adequately recognise the classic appearances of COVID-19 on CT, as described by the CO-RADS assessment scheme, in a way comparable to expert radiologists. Implications for practice: Radiographers, as the first healthcare professionals to evaluate CT images in patients with suspected SARS-CoV-2 infection, could diagnose COVID-19 pneumonia by means of a categorical reporting scheme at CT in a reliable way, hence playing a primary role in the early management of these patients