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Base stations equipped with large multi-antenna systems and associated beamforming schemes provide large capacity and coverage. Massive multiple-input-multiple-output (MIMO) with beamforming was introduced as one of the enablers of 5G system performance, and this technology is evolving with the introduction of more advanced algorithms for spatial multiplexing. One of the most relevant conditions to support deployment of 5G base stations with massive MIMO is to assess realistic RF electromagnetic field exposure compliance distances leveraging the actual maximum approach introduced in IEC 62232:2022. This evaluation method takes into account the variability of traffic load and beam patterns used by the beamforming algorithm. This work investigates the impact of various beamforming schemes, like grid-of-beams, eigen-beamforming and zero-forcing, as well as various array antenna configurations on the evaluation of the power reduction factor used when implementing the actual maximum approach for RF electromagnetic field compliance assessment of massive MIMO base stations. The modelling results show that lower power reduction factors can be considered for eigen-beamforming and zero-forcing beamforming algorithms compared to grid-of-beam. The power reduction factor drop can be up to −4 dB when 8 user equipment’s are connected simultaneously.

This article introduces this special issue by addressing the types of assessment practices that are possible within STEM inquiry classrooms, where the focus is on noticing, developing, and improving inquiry competencies. Three domains are explored: informal formative assessment occurring in classroom interactions; structured formative assessment when teachers or peers collect information at a planned time; ongoing evolution of teachers' knowledge and practices. We analyse how classroom formative assessment practices develop alongside and support inquiry learning. We report on how STEM teachers might be supported in transforming their teaching practices and assessment methods in tandem. We focus on the role of classroom discussion to challenge students' ideas and make explicit their reasoning. We highlight how interactions between teachers and students support students in being more active in the assessment process. Combining inquiry learning with adapted assessment practices requires teachers to make significant changes to their practices. They need to be aware of how students develop their learning. Such professional moves are complex because implementing formative and summative assessments in a complementary manner remains a challenge for teachers and researchers. We emphasise how the collaboration between researchers and teachers support teachers in making changes to their professional knowledge, beliefs, and classroom practices.

Discursive formative assessment (FA) practices during instruction have grown in importance in the education literature as a way of improving teaching and learning. This study involves three years of design-based research as part of an educational project. We examine lower secondary school teachers' qualitative Informal Formative assessment (IFA) practices during inquiry-based Science, Mathematics and Technology-Engineering (STEM) lessons. In-service teachers (N = 9) were filmed during a whole-classroom discussion session with respect to students' alternative solutions or predictions in the context of problem-solving or investigating a natural phenomenon. The analysed discussions in the project's third year lasted 15-30 minutes. The ESRU (Eliciting, Student response, Recognising and Using phases) model is adapted to analyse IFA practices, while also considering the role played by students. Inquiry dimensions (e.g. conceptual and epistemic) were used to examine the inquiries given priority in these discussions. The results show frequent (>30%) ESRU complete-cycle implementations by most teachers, which is associated with effective IFA practices. Frequent complete-cycle implementation led to teachers eliciting the same students at different moments of the session with longer consecutive cycles. The dimensions the teachers implement are more epistemic than conceptual. Moreover, students took charge of several ESRU phases.

The International Electrotechnical Commission (IEC) develops and validates methods for assessing radio frequency electromagnetic field (RF EMF) exposure due to base stations (BS). When the assessment is performed in- situ, it is recommended to extrapolate the maximum level of exposure from measurement of stable signals, such as broadcast signal with BS of the 5th generation (5G) of mobile communication systems (gNodeB). A comparative statistical analysis of extrapolation methods based on nominal antenna pattern (as measured in an anechoic chamber) and effective antenna pattern (as measured in scattering environment) of gNodeB is presented in this paper. This theoretical analysis shows that extrapolation with nominal antenna pattern may lead to significant overestimation of the maximum RF EMF exposure (up to 5.4 dB) in case of scattering environment or non-line-of-sight (NLOS) conditions. This overestimation is expected to be reduced by using effective antenna pattern in order to better represent the actual propagation conditions, such as those found in urban or dense urban areas. Therefore, it is recommended to perform extrapolation of the maximum exposure based on joint modeling of antenna beam pattern and representative value of the angular spread (AS) for the targeted deployment conditions. This conclusion was obtained from the observed consistence between two different approaches for determination of effective antenna gain. The first approach assumes statistical simulations with full three-dimensional (3D) channel model, especially distribution function of AS. The second approach enables simpler calculation of the effective antenna gain in scattering environment or NLOS conditions by considering only representative values from the full range of AS distribution function. The proposed simple method, if used with representative realistic values of AS, could reduce overestimation of RF EMF exposure resulting from an extrapolation factor based on nominal antenna gains of broadcast and traffic beams.

The development of a capnometry wristband is of great interest for monitoring patients at home. We consider a new architecture in which a non-dispersive infrared (NDIR) optical measurement is located close to the skin surface and is combined with an open chamber principle with a continuous circulation of air flow in the collection cell. We propose a model for the temporal dynamics of the carbon dioxide exchange between the blood and the gas channel inside the device. The transport of carbon dioxide is modeled by convection–diffusion equations. We consider four compartments: blood, skin, the measurement cell and the collection cell. We introduce the state-space equations and the associated transition matrix associated with a Markovian model. We define an augmented system by combining a first-order autoregressive model describing the supply of carbon dioxide concentration in the blood compartment and its inertial resistance to change. We propose to use a Kalman filter to estimate the carbon dioxide concentration in the blood vessels recursively over time and thus monitor arterial carbon dioxide blood pressure in real time. Four performance factors with respect to the dynamic quantification of the CO2 blood concentration are considered, and a simulation is carried out based on data from a previous clinical study. These demonstrate the feasibility of such a technological concept.

Degeneration of the intervertebral disc is one of the most frequent causes of lumbar pain, and it puts an extreme strain on worldwide healthcare systems. Finding a solution for this disease is an important challenge as current surgical and conservative treatments fail to bring a short-term or long-term solution to the problem. Medical ozone has yielded excellent results in intervertebral disc pathology. When it comes to extruded disc herniation, ozone is the only etiological treatment because it stimulates the immune system to absorb the herniated portion of the nucleus pulposus, thus resolving discal extrusion. This work aims to examine the biomolecular mechanisms that lead to intervertebral disc degeneration while highlighting the significance of oxidative stress and chronic inflammation. Considering that ozone is a regulator of oxidative stress and, therefore, of inflammation, we assert that medical ozone could modulate this process and obtain inflammatory stage macrophages (M1) to switch to the repair phase (M2). Consequently, the ozone would be a therapeutic resource that would work on the etiology of the disease as an epigenetic regulator that would help repair the intervertebral space.

Developing inquiry-based science teaching (I.B.S.T.) methods in lower secondary schools challenges many schools and educational bodies. The paper addresses the influence of teacher collaboration on science teachers' approaches and practices regarding I.B.S.T. The research emphasises three case studies: two science teachers, one expert and one new teacher, attending programmes based on teacher collaboration; one experienced teacher without any specific training on I.B.S.T.. Each of the three teachers was videotaped during one classroom session and interviewed about the video directly after the lesson. Their practices were portrayed in terms of the six crucial dimensions and indicators of I.B.S.T. Differences were seen among the three teachers. The two teachers attending programmes based on teacher collaboration employ teaching approaches and practices with greater emphasis on learning and learners. The isolated teacher's approaches and practices are more content- and teacher-centred. These findings concurred with quantitative results from the broader sample from which the case study was drawn. Outcomes concerning teacher training are discussed.

Developing inquiry-based science teaching (I.B.S.T.) methods in lower secondary schools challenges many schools and educational bodies. The paper addresses the influence of teacher collaboration on science teachers’ approaches and practices regarding I.B.S.T. The research emphasises three case studies: two science teachers, one expert and one new teacher, attending programmes based on teacher collaboration; one experienced teacher without any specific training on I.B.S.T.. Each of the three teachers was videotaped during one classroom session and interviewed about the video directly after the lesson. Their practices were portrayed in terms of the six crucial dimensions and indicators of I.B.S.T. Differences were seen among the three teachers. The two teachers attending programmes based on teacher collaboration employ teaching approaches and practices with greater emphasis on learning and learners. The isolated teacher’s approaches and practices are more content- and teacher-centred. These findings concurred with quantitative results from the broader sample from which the case study was drawn. Outcomes concerning teacher training are discussed.

Abstract Background Thanks to a reasonable cost and simple sample preparation procedure, linear MALDI-ToF spectrometry is a growing technology for clinical microbiology. With appropriate spectrum databases, this technology can be used for early identification of pathogens in body fluids. However, due to the low resolution of linear MALDI-ToF instruments, robust and accurate peak picking remains a challenging task. In this context we propose a new peak extraction algorithm from raw spectrum. With this method the spectrum baseline and spectrum peaks are processed jointly. The approach relies on an additive model constituted by a smooth baseline part plus a sparse peak list convolved with a known peak shape. The model is then fitted under a Gaussian noise model. The proposed method is well suited to process low resolution spectra with important baseline and unresolved peaks. Results We developed a new peak deconvolution procedure. The paper describes the method derivation and discusses some of its interpretations. The algorithm is then described in a pseudo-code form where the required optimization procedure is detailed. For synthetic data the method is compared to a more conventional approach. The new method reduces artifacts caused by the usual two-steps procedure, baseline removal then peak extraction. Finally some results on real linear MALDI-ToF spectra are provided. Conclusions We introduced a new method for peak picking, where peak deconvolution and baseline computation are performed jointly. On simulated data we showed that this global approach performs better than a classical one where baseline and peaks are processed sequentially. A dedicated experiment has been conducted on real spectra. In this study a collection of spectra of spiked proteins were acquired and then analyzed. Better performances of the proposed method, in term of accuracy and reproductibility, have been observed and validated by an extended statistical analysis.

Abstract Background In the field of biomarker validation with mass spectrometry, controlling the technical variability is a critical issue. In selected reaction monitoring (SRM) measurements, this issue provides the opportunity of using variance component analysis to distinguish various sources of variability. However, in case of unbalanced data (unequal number of observations in all factor combinations), the classical methods cannot correctly estimate the various sources of variability, particularly in presence of interaction. The present paper proposes an extension of the variance component analysis to estimate the various components of the variance, including an interaction component in case of unbalanced data. Results We applied an experimental design that uses a serial dilution to generate known relative protein concentrations and estimated these concentrations by two processing algorithms, a classical and a more recent one. The extended method allowed estimating the variances explained by the dilution and the technical process by each algorithm in an experiment with 9 proteins: L-FABP, 14.3.3 sigma, Calgi, Def.A6, Villin, Calmo, I-FABP, Peroxi-5, and S100A14. Whereas, the recent algorithm gave a higher dilution variance and a lower technical variance than the classical one in two proteins with three peptides (L-FABP and Villin), there were no significant difference between the two algorithms on all proteins. Conclusions The extension of the variance component analysis was able to estimate correctly the variance components of protein concentration measurement in case of unbalanced design.

Ozone therapy has been used to treat disc herniation for more than four decades. There are several papers describing results and mechanism of action. However, it is very important to define the characteristics of extruded disc herniation. Although ozone therapy showed excellent results in the majority of spinal diseases, it is not yet fully accepted within the medical community. Perhaps it is partly due to the fact that, sometimes, indications are not appropriately made. The objective of our work is to explain the mechanisms of action of ozone therapy on the extruded disc herniation. Indeed, these mechanisms are quite different from those exerted by ozone on the protruded disc herniation and on the degenerative disc disease because the inflammatory response is very different between the various cases. Extruded disc herniation occurs when the nucleus squeezes through a weakness or tear in the annulus. Host immune system considers the nucleus material to be a foreign invader, which triggers an immune response and inflammation. We think ozone therapy modulates this immune response, activating macrophages, which produce phagocytosis of extruded nucleus pulposus. Ozone would also facilitate the passage from the M1 to M2 phase of macrophages, going from an inflammatory phase to a reparative phase. Further studies are needed to verify the switch of macrophages.

Inquiry-based science teaching (IBST) is promoted without any clear definition of the teaching strategies that are expected. The paper portrays the variety of the nature and development of teacher professional knowledge and practice regarding inquiry-based science teaching. It proposes and tests a model built upon six dimensions that represent the crucial characteristics of IBST: the origin of questioning, the nature of the problem, students' responsibility in conducting the inquiry, the management of student diversity, the role of argumentation, and the explanation of the teacher's goals. Each dimension consists of a continuum of four modalities that describe the variety of teaching strategies and range from teacher- to student-centred ways of performing IBST. This model is tested through an analysis of observations and interviews with 18 secondary science teachers who differ regarding their involvement in teacher collaboration and the length of their teaching experience. The model is capable of distinguishing three types of teachers in a way that is coherent with previous results: teachers engaged in collective settings perform more student-centred teaching strategies than experienced teachers who are isolated. This six-dimensional model of IBST might be of value to researchers and teacher educators who are confronted with the complexity of inquiry-based science teaching.

La gestion patrimoniale des infrastructures s’intéresse à la connaissance et à l’évaluation de l’état d’un patrimoine et de sa capacité à fournir un service, tout en améliorant sa fiabilité. À partir de la caractérisation des services rendus par deux types d'infrastructures, les ouvrages de protection et les réeaux urbains, cet article analyse les notions de risque, vulnérabilité et résilience afin de faire émerger un nouveau référentiel pour une gestion patrimoniale des infrastructures durable.

La recherche concerne l’étude des effets de différentes modalités d’évaluation formative sur l’autorégulation des apprentissages des élèves, dans le cadre de l’enseignement scientifique fondé sur l’investigation. Des indicateurs nous permettant d’analyser les processus in situ sont construits et deux situations d’enseignement sont comparées. La première porte sur l’évaluation formative que les enseignants mettent en oeuvre dans leur pratique quotidienne. La seconde concerne l’évaluation formative mise en oeuvre par les mêmes enseignants l’année suivante, à la suite d’un travail réflexif avec des chercheurs. Après avoir confirmé, par le biais d’une analyse statistique, que les enseignants mettent en oeuvre différentes modalités d’évaluation formative d’une année à l’autre, nous décrivons les pratiques évaluatives des enseignants et leurs effets sur les élèves. Nous observons un meilleur équilibre dans l’usage des différentes modalités d’évaluation formative par les enseignants dans la seconde situation ainsi qu’une autorégulation plus efficace des comportements des élèves dans la tâche proposée.

The cells in an organism emit different amounts of proteins according to their clinical state (healthy/pathological, for instance). The resulting proteomic profile can be used for early detection, diagnosis, and therapy planning. In this paper, we study the classification of a proteomic sample from the point of view of an inverse problem with a joint Bayesian solution, called inversion-classification. We propose a hierarchical physical forward model and present encouraging results from both simulation and clinical data.

This article investigates teaching as collective work. The goals, functions and forms of teachers' collective work and changes in the professional representations or repertoire of actions through collective activity are identified. A synthetic framework is outlined and shown to be useful in addressing the data, by revealing the importance of interactions in professional competence acquisition. The article relates this framework to data collected from new teachers in the induction year in Scottish secondary schools (age range of pupils 11-18 years) and discusses the relationship of collective work to competence standards. Some issues for teacher educators and further research questions are identified. (Contains 2 endnotes and 1 figure.)

This article aims to increase understanding and knowledge concerning teachers' competence enhancement. Models used in industrial contexts are analysed in order to elaborate a framework relevant to understand teachers' learning. This specifies components of the work environment that are mobilised by teachers in order to achieve their goals. It is used to identify ways in which teachers in France manage to improve their practice despite being involved in complex and difficult situations. The data come from 60 interviews. The results highlight the effects of the organisation of the collective work situations: spurring exchanges amongst teachers and school partners appears to be a main factor for improving teachers' conceptions about teaching. Some ideas are outlined for constructing new continuing professional development programmes and studying their effects. (Contains 2 figures and 2 tables.)

La gestion patrimoniale des infrastructures s'intéresse à la connaissance et à l'évaluation de l'état d'un patrimoine et de sa capacité à fournir un service, tout en améliorant sa fiabilité. À partir de la caractérisation des services rendus par deux types d'infrastructures, les ouvrages de protection et les réeaux urbains, cet article analyse les notions de risque, vulnérabilité et résilience afin de faire émerger un nouveau référentiel pour une gestion patrimoniale des infrastructures durable.

The aim of our work is to quantify two gases (acetone and ethanol) diluted in an air buffer using only a single metal oxide (MOX) sensor. We took advantage of the low selectivity of the MOX sensor, exploiting a dual-temperature mode. Working at two temperatures of the MOX sensitive layer allowed us to obtain diversity in the measures. Two virtual sensors were created to characterize our gas mixture. We presented a linear-quadratic mixture sensing model which was closer to the experimental data. To validate this model and the experimental protocol, we inverted the system of quadratic equations to quantify a mixture of the two gases. The linear-quadratic model was compared to the bilinear model proposed in the literature. We presented an experimental evaluation on mixtures made of a few ppm of acetone and ethanol, and we obtained a precision close to the ppm. This is an important step towards medical applications, particularly in terms of diabetes, to deliver a non-invasive measure with a low-cost device.

L’étude porte sur les conceptualisations des enseignants qui sous-tendent leur travail collectif. Le cadre d’analyse intègre les composants du contexte (situation et acteurs) et l’espace professionnel considéré par les acteurs pour réguler leur activité liée au travail collectif. L’étendue et l’organisation de cet espace professionnel caractérisent les conceptualisations du travail collectif (CC). L’étude est fondée sur 96 entretiens. Les variables de contexte sont la situation d’exercice (primaire ou secondaire; secteur défavorisé ou ordinaire), la durée d’expérience, le niveau d’implication dans des rencontres régulières avec divers partenaires. Les résultats montrent que le niveau d’implication a un effet positif marqué sur CC, quelle que soit la durée de l’expérience ou la situation.

In this work, we study the theoretical conditions on a X-ray computed tomography (CT) acquisition protocol to get high temporal and spatial resolution reconstructions of the slices of an object, under the hypothesis that the object has a cyclic evolution. We first show how the rotation time setting influences the theoretically reachable temporal resolution and how this setting should be optimized. Then for the discrete acquisitions, we propose efficient sampling schemes based on the generalization of the sampling conditions in helical CT. Both approaches, adjustment of rotation speed and sampling conditions, are then combined to propose optimal acquisition protocols in order to reduce the amount of measured data and improve the quality of the reconstruction of an image sequence. These results could be applied to cardiac imaging, when the periodicity hypothesis is acceptable during the short acquisition time. Index Terms--Acquisition protocol, cardiac CT, periodic CT, sampling conditions.

The present study aims at understanding the observed gap between routine medical practice of some French physicians working in a psychiatric hospital and the available clinical guidelines Based on the theoretical field of didactic including conceptualisation, semi directed interviews were conducted with 12 physicians working in the same psychiatric hospital, chosen depending on their seniority and expertise levels. The results allow building the referential for their clinical activity and outlining what is needed regarding the training of these physicians.

De nombreux pays de l’Union européenne sont en train de mettre au point des programmes visant l’intégration des TIC (technologies de l’information et de la communication) dans le curriculum et le quotidien de l’école. Les auteurs travaillent sur la méthodologie de l’évaluation de cette intégration, tout en participant à son implantation par l’intermédiaire du Programme Nónio-XXIe siècle. Il s’agit d’une initiative du ministère de l’Éducation portugais qui associe les écoles et l’Université du Minho. Le texte dégage un projet d’évaluation qui intègre les acteurs, les moments, les objets et les instruments. Il insiste sur le fait que les procédures d’évaluation doivent être le résultat d’une réflexion sur sa logique elle-même ; qu’il est pertinent d’évaluer non seulement le produit mais aussi le processus ; que l’évaluation doit surtout contribuer à une meilleure gestion de l’action ou des actions qui se développent. L’évaluation apparaît alors comme un processus de recueil des données utiles à la prise de décisions qui jalonnent le fonctionnement du curriculum.

L’étude cherche à définir des conditions sous lesquelles un processus d’évaluation des dispositifs d’enseignement peut être formatrice pour ses acteurs. Ces dispositifs définissent la qualité du curriculum réel, construit par chaque établissement de façon plus ou moins réfléchie. L’étude porte sur l’analyse d’une formation d’enseignants centrée sur la construction d’outils d’évaluation de leurs propres dispositifs. L’investigation, menée ici par questionnaires, montre que l’engagement des enseignants dans la construction des référentiels bouscule leurs certitudes et que le travail d’élaboration se poursuit après le stage, que la dynamique d’adaptation des dispositifs d’enseignement aux élèves est renforcée et que l’attention se porte sur l’efficacité des actions en fonction des particularités du public. Une telle formation semble donc participer à l’amélioration de la qualité du curriculum.

A method is presented for estimating the geometrical parameters of cone beam systems with multiple heads, each head having its own orientation, In tomography, for each head, the relative position of the rotation axis and of the collimator do not change during the data acquisition. We thus can separate the parameters into intrinsic parameters and extrinsic parameters. The intrinsic parameters describe the detection system geometry and the extrinsic parameters the position of the detection system with respect to the rotation axis. Intrinsic parameters are measured directly, once for each collimator. Extrinsic parameters must be estimated each time the acquisition geometry is modified. Extrinsic parameters are estimated by minimizing the distances between the measured position of a point source projection and the computed position obtained using the estimated extrinsic parameters. The main advantage of this method is that the extrinsic parameters are only weakly correlated when the intrinsic parameters are known. Thus we can use any simple least square error minimization method to perform the estimation of the extrinsic parameters. Giving a fixed value to the distance between the point source and the rotation axis in the estimation process, ensures the coherence of the extrinsic parameters between each head. We show that with this calibration method, the full width at half maximum measured with point sources is very close to the theoretical one, and remains almost unchanged when more than one head is used. Simulation results and reconstructions on a Jaszczak phantom are presented that show the capabilities of this method.

We propose a new circular multifocal collimator which has multiple axial focal points distributed on a transverse circle. This distribution provides a strong focusing at the center of the detector like a cone-beam collimator, with a good sensitivity, and a weak transverse focusing at the periphery, to ensure acquisition of sufficient data, in order to prevent truncation artifacts. For a circular acquisition trajectory, each projection set of the multifocal geometry is equivalent to a virtual cone-beam projection set with a larger detector. Due to this equivalence, we derive a first solution for an analytical multifocal reconstruction algorithm: to rebin the projection set from multifocal to cone-beam geometry, then to use a 3D cone-beam reconstruction algorithm. We propose to use the Grangeat algorithm in order to deal with a large cone-beam aperture. Finally, we present results on simulated data for heart phantom, for a Defrise phantom and for a MTF study. The conclusion is that, from a multifocal projection set, objects are reconstructed without truncation artifacts, with a good precision at their center and with a loss of resolution at the periphery. In addition, the 3D cone-beam artifacts are reduced with the use of the Grangeat algorithm for the reconstruction step.