On the generalized logistic random differential equation: Theoretical analysis and numerical simulations with real-world data

[EN] Based on the previous literature about the random logistic and Gompertz models, the aim of this paper is to extend the investigations to the generalized logistic differential equation in the random setting. First, this is done by rigorously constructing its solution in two different ways, namely, the sample-path approach and the mean-square calculus. Secondly, the probability density function at each time instant is derived in two ways: by applying the random variable transformation technique and by solving the associated Liouville's partial differential equation. It is also proved that both the stochastic solution and its density function converge, under specific conditions, to the corresponding solution and density function of the logistic and Gompertz models, respectively. The investigation finishes showing some examples, where a number of computational techniques are combined to construct reliable approximations of the probability density of the stochastic solution. In particular, we show, step-by-step, how our findings can be applied to a real-world problem. (c) 2022 The Author(s). Published by Elsevier B.V.This work has been supported by the Spanish Agencia Estatal de Investigacion grant PID2020-115270GB-I00. Vicente Bevia acknowledges the doctorate scholarship granted by Programa de Ayudas de Investigacion y Desarrollo (PAID), Universitat Politecnica de Valencia.Bevia, V.; Calatayud-Gregori, J.; Cortés, J.; Jornet-Sanz, M. (2023). On the generalized logistic random differential equation: Theoretical analysis and numerical simulations with real-world data. Communications in Nonlinear Science and Numerical Simulation. 116. https://doi.org/10.1016/j.cnsns.2022.10683211

Nanoantennas Design for THz Communication: Material Selection and Performance Enhancement

In the development of terahertz (THz) communication systems, the nanoantenna is the most significant component. Especially, the focus is to design highly directive antennas, because it enhances the performance of the overall system by compensating the large path loss at THz and thus improves the signal-to-noise ratio. This paper presents suitable material for nanoantenna design and the advancement in their performance for THz communications. Copper, Graphene, and carbon nanotube materials are used as promising candidates for nanoantenna design. The performance of nanoantennas is carried out by analyzing the properties and behavior of the material at THz. Results show that the Graphene nanoantenna provides better performance in terms of miniaturization, directivity, and radiation efficiency. Further, the performance enhancement of the nanoantenna at THz is studied by dynamically adjusting the surface conductivity via the chemical potential of Graphene using the electric field effect. The performance of the nanoantenna is enhanced in terms of high miniaturization, high directivity, low reflection, frequency reconfiguration, and stable impedance. The THz nanoantennas using Graphene have the potential to be used for THz communication systems. In view of the smart THz wireless environment; this paper finally presents a THz Hypersurface using Graphene meta-atoms. The user-side Graphene nanoantennas and environment-side Graphene Hypersurface can build a promising smart THz wireless environment

IAEA methodology for on-site end-to-end IMRT/VMAT audits : an international pilot study

The IAEA has developed and tested an on-site, end-to-end IMRT/VMAT dosimetry audit methodology for head and neck cases using an anthropomorphic phantom. The audit methodology is described, and the results of the international pilot testing are presented. The audit utilizes a specially designed, commercially available anthropomorphic phantom capable of accommodating a small volume ion chamber (IC) in four locations (three in planning target volumes (PTVs) and one in an organ at risk (OAR)) and a Gafchromic film in a coronal plane for the absorbed dose to water and two-dimensional dose distribution measurements, respectively. The audit consists of a pre-visit and on-site phases. The pre-visit phase is carried out remotely and includes a treatment planning task and a set of computational exercises. The on-site phase aims at comparing the treatment planning system (TPS) calculations with measurements in the anthropomorphic phantom following an end-to-end approach. Two main aspects were tested in the pilot study: feasibility of the planning constraints and the accuracy of IC and film results in comparison with TPS calculations. Treatment plan quality was scored from 0 to 100. Results: Forty-two treatment plans were submitted by 14 institutions from 10 countries, with 79% of them having a plan quality score over 90. Seventeen sets of IC measurement results were collected, and the average measured to calculated dose ratio was 0.988 ± 0.016 for PTVs and 1.020 ± 0.029 for OAR. For 13 film measurement results, the average gamma passing rate was 94.1% using criteria of 3%/3 mm, 20% threshold and global gamma. The audit methodology was proved to be feasible and ready to be adopted by national dosimetry audit networks for local implementation

Analysis of the safety culture in a Cardiology Unit managed by processes

La cultura sobre seguridad se perfila como uno de los requisitos para evitar la aparición de efectos adversos, sin embargo no se ha estudiado en el ámbito de la cardiología. El objetivo es evaluar la cultura de seguridad en una unidad de cardiología que tiene implantado y certificado un sistema integrado de gestión de calidad y riesgos para la seguridad del paciente. Método: Se realizó un estudio observacional trasversal en 2 años consecutivos utilizando la encuesta Hospital Survey on Patient Safety Culture de la «Agency for Healthcare Research and Quality» en su versión española (42 ítems agrupados en 12 dimensiones) sobre todo el personal. Se comparó el porcentaje de respuestas positivas de cada dimensión en 2014 y 2015, así como con los datos a nivel nacional y en EE. UU., siguiendo las recomendaciones establecidas. Resultados: La valoración global, sobre un máximo de 5, fue de 4.5 en 2014 y de 4.7 en 2015. Identificamos 7 dimensiones como fortaleza. Las peor valoradas fueron: Dotación de personal, Apoyo de la gerencia y Trabajo en equipo entre unidades. La comparación mostró superioridad en todas las dimensiones a nivel nacional, y en 8 respecto a los datos del registro americano. Conclusiones: La cultura de seguridad en una unidad de cardiología con un sistema integrado de gestión de calidad y riesgos y seguridad del paciente es elevada, superior a la nacional en todas sus dimensiones y en la mayoría de ellas respecto al registro de EE. UU.The safety culture is one of the requirements to prevent the occurrence of adverse effects, however has not been studied in the field of cardiology. The objective is to evaluate the safety culture in a cardiology unit has implemented and certified an integrated quality and risk management for patient safety system. Methods: A transversal observational study was made in 2 consecutive years using the survey “Hospital Survey on Patient Safety Culture” of the “Agency for Healthcare Research and Quality” in its Spanish version (42 items grouped into 12 dimensions) in all staff. The percentage of positive responses in each dimension in 2014 and 2015 were compared, as well as national data and United States data, following the established rules. Results: The overall assessment of a possible 5, was 4.5 in 2014 and 4.7 in 2015. We identified seven dimensions as a fortress. The worst rated were: staffing, management support and teamwork between units. The comparison showed superiority in all dimensions respect to national data, and 8 respect to American data. Conclusions: The safety culture in a Cardiology Unit with an integrated quality and risk management and patient safety system is high, higher than the national in all its dimensions and in most of them respect to the United States

What is plan quality in radiotherapy? The importance of evaluating dose metrics, complexity, and robustness of treatment plans

Plan evaluation is a key step in the radiotherapy treatment workflow. Central to this step is the assessment of treatment plan quality. Hence, it is important to agree on what we mean by plan quality and to be fully aware of which parameters it depends on. We understand plan quality in radiotherapy as the clinical suitability of the delivered dose distribution that can be realistically expected from a treatment plan. Plan quality is commonly assessed by evaluating the dose distribution calculated by the treatment planning system (TPS). Evaluating the 3D dose distribution is not easy, however; it is hard to fully evaluate its spatial characteristics and we still lack the knowledge for personalising the prediction of the clinical outcome based on individual patient characteristics. This advocates for standardisation and systematic collection of clinical data and outcomes after radiotherapy. Additionally, the calculated dose distribution is not exactly the dose delivered to the patient due to uncertainties in the dose calculation and the treatment delivery, including variations in the patient set-up and anatomy. Consequently, plan quality also depends on the robustness and complexity of the treatment plan. We believe that future work and consensus on the best metrics for quality indices are required. Better tools are needed in TPSs for the evaluation of dose distributions, for the robust evaluation and optimisation of treatment plans, and for controlling and reporting plan complexity. Implementation of such tools and a better understanding of these concepts will facilitate the handling of these characteristics in clinical practice and be helpful to increase the overall quality of treatment plans in radiotherapy

Patients’ experience of recurrent/metastatic head and neck squamous cell carcinoma and their perspective on the EORTC QLQC30 and QLQ-H&N35 questionnaires: a qualitative study

Abstract Background Head and neck squamous cell carcinoma (HNSCC) and its associated treatments may affect all aspects of patients’ health-related quality of life (HRQoL). Although the EORTC QLQ-H&N35 is regularly administered to patients with HNSCC, there is a paucity of studies re-assessing the conceptual relevance of this patient-reported outcome (PRO) measure from a patient perspective. Furthermore, the content validity of the EORTC QLQ-C30 has not been widely documented in patients with recurrent and/or metastatic HNSCC. The objectives of this study were to understand patients’ experiences of recurrent/metastatic HNSCC and its treatments, and to evaluate the conceptual relevance and acceptability of the EORTC QLQ-C30 and QLQ-H&N35 from a patient perspective for use in clinical trials. Methods A literature review and clinician interviews were conducted to inform in-depth semi-structured telephone interviews with US patients who had received treatment for recurrent and/or metastatic HNSCC in the preceding 12 months. Interview transcripts were analysed thematically using ATLAS.ti v7; patient quotes were coded to identify concepts and themes to develop a conceptual model of HNSCC experience. Results Fourteen patients were interviewed (71% male, aged 35–84 years). Patients reported few symptoms pre-diagnosis including neck lump/swelling (n = 7/14, 50%) and/or difficulty swallowing (n = 3/14, 21%). Treatments generally comprised surgery and chemotherapy and/or radiotherapy. A number of side effects from all treatments were reported. Numbness, difficulty speaking and pain were the most reported side effects of surgery (n = 4/8, 50%); weight loss and fatigue were the most reported side effects of chemotherapy and/or radiotherapy (n = 8/13, 61%). All side effects negatively impacted patients’ HRQoL. Patients generally found the QLQ-C30 and QLQ H&N35 content to be understandable and conceptually relevant; excessive mucous production and neuropathic symptoms were among the suggested additions. Conclusions HNSCC and its diverse symptoms and treatments have a negative impact on many aspects of patients’ lives. A number of reported symptoms including difficulty speaking and swallowing, localised pain and fatigue may be important for treatment benefit evaluation in clinical trials from a patient perspective. The QLQ-C30 and QLQ-H&N35 are generally relevant and suitable for use in clinical trials. However, some items could be amended/added to ensure conceptual comprehensiveness of these measures

An Ontological Approach to Inform HMI Designs for Minimizing Driver Distractions with ADAS

ADAS (Advanced Driver Assistance Systems) are in-vehicle systems designed to enhance driving safety and efficiency as well as comfort for drivers in the driving process. Recent studies have noticed that when Human Machine Interface (HMI) is not designed properly, an ADAS can cause distraction which would affect its usage and even lead to safety issues. Current understanding of these issues is limited to the context-dependent nature of such systems. This paper reports the development of a holistic conceptualisation of how drivers interact with ADAS and how such interaction could lead to potential distraction. This is done taking an ontological approach to contextualise the potential distraction, driving tasks and user interactions centred on the use of ADAS. Example scenarios are also given to demonstrate how the developed ontology can be used to deduce rules for identifying distraction from ADAS and informing future designs