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Teleoperation provides an innovative approach for completing tasks in environments where humans cannot be physically present, such as hazardous or difficult-to-reach areas. Augmented Reality (AR) enhances this process by overlaying critical information directly into the user’s field of view, streamlining task execution and spatial awareness. This paper presents a comprehensive topical review of recent trends in both teleoperation and AR, highlighting their integration to improve remote human-machine interaction. We analyze advancements in both technologies, identify practical applications, and offer insights into their convergence in fields such as aerospace, medical robotics, and industrial automation. By examining academic publications and statistical trends from major databases, we project the future trajectory of AR-teleoperation and discuss potential challenges in implementing these systems, particularly regarding latency, cognitive overload, and security. This topical review aims to provide a detailed analysis of the state of the art and offers insights for future research in this rapidly evolving field.

Several reports in the literature concern the thermal properties of porous silicon samples considering the porous layer plus the silicon substrate, but not so of the porous layer in particular. This work uses the frequency domain photoacoustic technique in a heat transmission configuration together with an analysis based on a composite two-layer model of thermal resistances on n-type porous silicon and the porosity concept to develop a non-separative (and hence non-destructive) methodology for determining the thermal properties of the porous layer of n-type porous silicon and provide analytical models to obtain such properties as a function of its porosity. The porous silicon samples were elaborated by anodization, with anodization times from 10 to 100 min on (100)-oriented n-type crystalline silicon wafers and using a 48% hydrofluoric acid water solution. These wafers were non-degenerated, phosphorous doped, 500 μm roughly thick, and had 1.72 Ω cm electrical resistivity. In each sample, gravimetry determined porosity ranging from 0.279 to 0.702, and the porous layer's thickness was determined by electron microscopy. An analytical expression was obtained for the effective thermal diffusivity of the n-type porous silicon as a whole. After fitting it to the data obtained by the photoacoustic measurements, a value around 0.076 cm2/s, independent of porosity, was obtained for the thermal diffusivity of the porous layer. In addition, analytical expressions were obtained for the porous layer's thermal conductivity, volumetric heat capacity, and thermal effusivity, all showed a decreasing linear dependence on the porosity. [ABSTRACT FROM AUTHOR]

JAIRO MORENO. Sounding Latin Music, Hearing the Americas. Chicago: University of Chicago Press, 2023. 376 pp. ISBN: 9780226825687. Jairo Moreno's Sounding Latin Music, Hearing the Americas explores how music making [...]

This article deals with the design and implementation of a characterization system for thermoelectric modules in thermal energy collection systems in solar concentration systems. The design procedure involves the development of a modular system that includes a robotic manipulator for the solar tracking in the concentration task, an instrumentation system that considers the thermal conditions to avoid leakages or incorrect measurements, and a central processing system connected to a user interface. Each system was designed and validated computationally and the system integration was performed according to the concurrent engineering concepts. Finally, the system was tested in different modules providing adequate working conditions (collecting appropriate differentials of temperature) for five different thermoelectric modules in controlled conditions and in solar collector applications.

This article deals with modelling and a flatness-based robust trajectory tracking scheme for a two degrees of freedom helicopter, which is subject to four types of tail rotor disturbances to validate the control scheme robustness. A mathematical model of the system, its differential flatness and a differential parametrization are obtained. The flat filtering control is designed for the system control with a partially known model, assuming the non-modelled dynamics and the external disturbances (specially the tail rotor ones) to be rejected by means of an extended state model (ultra-local model). Numerical and experimental assessments are carried out on a characterized prototype whose yaw angle (ψ), given by the z axis, is in free form, while the pitch angle (θ), which results from rotation about the y axis, is mechanically restricted. The proposed controller performance is tested through a set of experiments in trajectory tracking tasks with different disturbances in the tail rotor, showing robust behaviour for the different disturbances. Besides, a comparison study against a widely used controller of LQR type is carried out, in which the proposed controller achieves better results, as illustrated by a performance index.

In the last decade, quadrotors have gained popularity among industry and academia due to their capabilities and the various applications in which they can be found. In addition to the above, because this is an underactuated system, researchers have found it a great challenge to control. Despite this, there is a wide variety of methodologies in the literature to control this type of system. Based on the above, this work proposed an alternative to trajectory tracking control for quadrotor unmanned aerial vehicles (UAV). The problem was divided into two main control loops: an outer control loop for the position coordinates, tackled through linear active disturbance rejection controllers (ADRC), and an inner control loop related to the orientation variables, addressed via robust proportional-integral-differential (PID) controllers. Furthermore, a generalized proportional integral observer (GPIO) was implemented to estimate the velocity and internal and external disturbances; therefore, the control strategy only depended on the attitude (position and orientation) quadrotor measurements. Then, the control performance was tested through numerical simulations and experimental tests, including wind disturbance inputs.

BackgroundCOVID-19-related acute hypoxic respiratory failure patients often use high-flow nasal cannula (HFNO) oxygen therapy. COVID-19 HFNO intubation and mortality risk factors are understudied in the Mexican population, so the aim was to study them.MethodsThis retrospective study searched electronic medical records from March 2020 to June 2022 for patients with COVID-19 who required hospitalization and HFNO. Descriptive statistics, a survival curve analysis, and Cox proportional hazard models were used to determine predictor factors for intubation and mortality in patients with HFNO and COVID-19, respectively.ResultsA total of 134 patients received HFNO treatment. Ninety-one (67.9%) were men with a mean (SD) age of 54.5 (17.9) years. Common medical history included obesity (n = 89, 66.4%) with a Body Mass Index (BMI) mean (SD) of 31.8 (5.9), hypertension (n = 67, 50.0%), type 2 diabetes (n = 55, 41.0%), and dyslipidemias (n = 43, 32.1%). The variables associated with a greater risk of requiring intubation after high-flow therapy were age (HR = 1.018, 95% CI 1.003-1.034, p = 0.022) and BMI (HR = 1.071, 95% CI 1.024-1.120, p = 0.003). No variables were associated with lower risk. Increased mortality was associated with increasing age (HR = 1.151, 95% CI 1.102-1.201, p = ConclusionsA higher age and BMI were associated with an increased risk of intubation in patients with HFNO and COVID-19. Hypertension and dyslipidemias were associated with a higher risk of mortality.

In the present work, based on an approximate modelling of a rover-type robot and a proportional control law, a simplified trajectory tracking strategy for a passive suspension rover-type mobile robot was developed. This strategy achieves trajectory tracking and the autonomous displacement of a rover, of which its configuration involves complex kinematics and dynamics. All these lineaments reduce the complexity of the analysis, the number of electronic components to implement, the computational requirements and the energy consumption. The robotic system used is based on the Shrimp rover, which is a robot with a passive suspension that is capable of carrying out displacements over rough terrain. The tests were performed using numerical simulations with different desired trajectories, and also using experimental tests using a passive suspension rover-type mobile robot.

Background: The temperature upshift has been widely used as an induction system to produce recombinant proteins (RPs). However, thermoinduction could affect bacterial metabolism, RP production, and RP aggregation. Understanding the structure and functionality of those aggregates, known as inclusion bodies (IBs), is a research area of interest in bioprocesses being scarcely studied under thermoinduction. Here, we describe the effect of the thermoinduction (39°C or 42°C) on the production of the recombinant human granulocyte–macrophage colony-stimulating factor (rHuGM-CSF) using Escherichia coli W3110 under the system λpL/cI857. Results: Results indicated that at 39°C, the production of biomass was almost doubled as well as the acetate accumulation compared to 42°C. Cultures thermoinduced at 42°C improved 1.5-fold the total protein over biomass yield and 1.25-fold the RP over total protein yield. Furthermore, 42°C accelerated the onset of IB formation, changing its architecture. Additionally, IBs formed at 42°C were less soluble and presented higher disorderly structures compared with IBs formed at 39°C, enriched in α-helix and amyloidal-like structures. Conclusions: This study highlights the observation that IBs attain different architecture in response to small changes in environmental conditions, such as the induction temperature, being this helpful information to improve thermoinduced bioprocesses.How to cite: Restrepo-Pineda S, Rosiles-Becerril D, Vargas-Castillo AB, et al. Induction temperature impacts the structure of recombinant HuGM-CSF inclusion bodies in thermoinducible E. coli. Electron J Biotechnol 2022;59. https://doi.org/10.1016/j.ejbt.2022.08.004.

In this work, six analytical solutions are given to estimate the energy exchange by transient conduction in pipes with convection conditions. The developed models were adjusted for an interval RI/RE ${R}_{I}/{R}_{E}$ from 0.2 to 0.8, dimensionless Fourier (Fo) and Biot (Bi) numbers, from 0.05 to 50 and 0.005 to 50, respectively. In each case, 616 tests of temperature distributions were computed using the Heisler approximate method (HAM) and the exact models proposed, for different combinations of RI/RE,Bi,and Fo ${R}_{I}/{R}_{E},{Bi},\mathrm{and}\unicode{x02007}{Fo}$. For the comparison made between the analytical solutions and the HAM, 3696 tests were used, detecting that the HAM correlates with the analytical method with an average deviation of ±10% $\pm 10 \% $ and ±20% $\pm 20 \% $ for 71.2%, and 90.4% of the different values of RI/RE,Fo,and Bi ${R}_{I}/{R}_{E},{Fo},\text{and}\unicode{x02007}{Bi}$ combinations evaluated. The best fit was found for Case 5, with a mean deviation of ±10% $\pm 10 \% $ and ±20% $\pm 20 \% $ for 81.1% and 92.3% of the data used, respectively, while the weaker fit was detected for Case 2, with a mean deviation of ±10% $\pm 10 \% $ and ±20% $\pm 20 \% $ for 67.9% and 88.2% of the available tests. [ABSTRACT FROM AUTHOR]

This study presents the design and evaluation of a prototype snake-like robot that possesses an actuation system based on shape memory alloys (SMAs). The device is constructed based on a modular structure of links connected by two degrees of freedom links utilizing Cardan joints, where each degree of freedom is actuated by an agonist–antagonist mechanism using the SMA spring-shaped actuators to generate motion, which can be easily replaced once they reach a degradation point. The methodology for programming the spring shape into the SMA material is described in this work, as well as the instrumentation required for the monitoring and control of the actuators. A simplified design is presented to describe the way in which the motion is performed and the technical difficulties faced in manufacturing. Based on this information, the way in which the design is adapted to generate a feasible robotic system is described, and a mathematical model for the robot is developed to implement an independent joint controller. The feasibility of the implementation of the SMA actuators regarding the motion of the links is verified for the case of a joint, and the change in the shape of the snake robot is verified through the implementation of a set of tracking references based on a central pattern generator. The generated tracking results confirm the feasibility of the proposed mechanism in terms of performing snake gaits, as well as highlighting some of the drawbacks that should be considered in further studies.

Lean Manufacturing has become, in recent years, one of the most important philosophies for improving production and organizational systems. The literature shows that Hesitant Fuzzy Linguistic Terms Sets (HFLTSs) are highly capable of manipulating the uncertainty that the judgments made by evaluators carry and that they are subject to their perception, especially when used in combination with multicriteria decision making (MCDM) for the measurement of indicators in this type of system, as well as their general performance. However, it is still of interest to researchers to develop techniques and instruments that facilitate the measurement of the results obtained after applying this philosophy in organizations. This article proposes a model for the evaluation of the Lean Manufacturing performance through the Analytic Hierarchy Process (AHP) and Dimensional Analysis (DA) using HFLTSs. The results obtained show that the proposed model is a solid tool for the evaluation of Lean Manufacturing systems from a different perspective and that it can be integrated into the issuance of evaluations in a better way by considering human subjectivity. At the same time, it offers a strategy to create priorities in the action plans that Lean system managers propose after evaluating. However, it is important to apply the proposed model to multiple organizations and analyze the results obtained to maximize its benefits.

Abstract We present a series of experiments with droplets of aqueous cyclodextrin-surfactant solutions, in which the volume is reduced after the equilibrium spherical shape is reached. The final shape of the drop after this perturbation is found to be dependent on the concentration of inclusion complexes in the bulk of the solution. These inclusion complexes are formed by two cyclodextrin molecules and one surfactat molecule. We propose a model to describe these dynamical processes. Dipole–dipole interactions on the surface of the drop trigger a competition between water surface tension and dipole–dipole interaction energies. The results of the model reproduce the spherical and rod-like shapes found in the experiments.

BackgroundThe values of viral load in COVID-19 disease have gained relevance, seeking to understand its prognostic value and its behavior in the course of the disease, although there have been no conclusive results. In this study we sought to analyze serum viral load as a predictor of clinical outcome of the disease, as well as its association with inflammatory markers.MethodsAn observational and retrospective study in a private hospital in North Mexico, patients with SARS-COV-2 infection confirmed by reverse transcriptase polymerase chain reaction (RT-PCR) were followed through clinical outcome, viral load measurement, quantification of inflammatory markers and lymphocyte subpopulations. For the analysis, multiple regression models were performed. Results: We studied 105 patients [47 (SD 1.46) years old, 68.6% men]. After analysis with multiple regression models, there was an association between viral load at admission and vaccination schedule (β-value=-0.279, p= 0.007), age (β-value= 0.010, p = 0.050), mechanical ventilation (β-value= 0.872, p = 0.007), lactate dehydrogenase (β-value= 1.712, p= 0.004), D-dimer values at admission (β-value= 0.847, p= 0.013) and subpopulation of B lymphocytes at admission (β-value= -0.527, p= 0.042). There was no association with days of hospitalization, use of nasal prongs or high flux mask. Peak viral load (10 days after symptoms onset) was associated with peak IL-6 (β-value= 0.470, p= 0.011). Peak viral load matched with peak procalcitonin and minimal lymphocyte values. C-reactive protein peak was before the peak of viral load. The minimum value viral load was documented on day 12 after symptom onset; it matched with the minimum values of IL-6 and ferritin, and the peak of D-dimer.ConclusionsSARS-COV-2 admission viral load is associated with vaccination status, mechanical ventilation, and different inflammatory markers.

Abstract Background 5-Methylcytosine (5mC) is an important epigenetic mark in eukaryotes. Little information about its role exists for invertebrates. To investigate the contribution of 5mC to phenotypic variation in invertebrates, alteration of methylation patterns needs to be produced. Here, we apply new non-nucleoside DNA methyltransferase inhibitors (DNMTi) to introduce aleatory changes into the methylome of mollusk species. Results Flavanone inhibitor Flv1 was efficient in reducing 5mC in the freshwater snails Biomphalaria glabrata and Physa acuta, and to a lesser degree, probably due to lower stability in sea water, in the oyster Crassostrea gigas. Flv1 has no toxic effects and significantly decreased the 5mC level in the treated B. glabrata and in its offspring. Drug treatment triggers significant variation in the shell height in both generations. A reduced representation bisulfite-sequencing method called epiGBS corroborates hypomethylation effect of Flv1 in both B. glabrata generations and identifies seven Differential Methylated Regions (DMR) out of 32 found both in Flv1-exposed snails and its progeny, from which 5 were hypomethylated, demonstrating a multigenerational effect. By targeted bisulfite sequencing, we confirmed hypomethylation in a locus and show that it is associated with reduced gene expression. Conclusions Flv1 is a new and efficient DNMTi that can be used to induce transient and heritable modifications of the epigenetic landscape and phenotypic traits in mollusks, a phylum of the invertebrates in which epigenetics is understudied.

The global impact of the SARS-CoV-2 infection has been substantial, affecting millions of people. Long COVID, characterized by persistent or recurrent symptoms after acute infection, has been reported in over 40% of patients. Risk factors include age and female gender, and various mechanisms, including chronic inflammation and viral persistence, have been implicated in long COVID’s pathogenesis. However, there are scarce studies in which multiple inflammatory markers and viral load are analyzed simultaneously in acute infection to determine how they predict for long COVID at long-term follow-up. This study explores the association between long COVID and inflammatory markers, viral load, and lymphocyte subpopulation during acute infection in hospitalized patients to better understand the risk factors of this disease. This longitudinal retrospective study was conducted in patients hospitalized with COVID-19 in northern Mexico. Inflammatory parameters, viral load, and lymphocyte subpopulation during the acute infection phase were analyzed, and long COVID symptoms were followed up depending on severity and persistence (weekly or monthly) and assessed 1.5 years after the acute infection. This study analyzed 79 patients, among them, 41.8% presented long COVID symptoms, with fatigue being the most common (45.5%). Patients with long COVID had higher lymphocyte levels during hospitalization, and NK cell subpopulation levels were also associated with long COVID. ICU admission during acute COVID-19 was also linked to the development of long COVID symptoms.

Animal monitoring systems often rely on expensive and challenging GPS-based systems to obtain accurate trajectories. However, an alternative approach is to generate synthetic trajectories that exhibit similar statistical properties to real trajectories. These synthetic trajectories can be used effectively in the design of surveillance systems such as wireless sensor networks and drone-based techniques, which aid in data collection and the delineation of areas for animal conservation and reintroduction efforts. In this study, we propose a data generation method that utilizes simple phase-type distributions to produce synthetic animal trajectories. By employing probability distribution functions based on the exponential distribution, we achieve highly accurate approximations of the movement patterns of four distinct animal species. This approach significantly reduces processing time and complexity. The research primarily focuses on generating animal trajectories for four endangered species, comprising two terrestrial and two flying species, in order to demonstrate the efficacy of the proposed method.

In this article, an Extended State Observer (ESO) based Active Disturbance Rejection Control (ADRC) scheme is applied to the Pendubot system for a trajectory tracking tasks. The tangent linearization of the system allows to implement the control scheme taking advantage of the differential flatness property, while including a cascade configuration. The proposed method assumes a limited knowledge of the underactuated system where the control input gain and the order of the system are the only needed data. The scheme is experimentally tested leading to accurate tracking results.

The new product development process (NPDP) is crucial for maintaining business up and running in manufacturing corporations worldwide. NPDP helps firms improve their profits, where stakeholder attention is mostly focused. NPDP Risk Assessment (NPDP-RA) is a vital activity to achieve a successful new product launch. However, managing different kinds of risks over the process presents enormous challenges; thus, risk assessment over NPDP still shows gaps, even when different tools are employed to identify, mitigate, and eliminate risks throughout the process. The identified gaps are mainly produced because the uncertainty added by the individuals assessing the risks, and the currently used tools are generally focused on a single phase of the NPDP, disregarding the stakeholders’ project objectives. This paper presents the main NPDP risks for stakeholders through the NPDP phases; likewise, the integration of Pythagorean fuzzy dimensional analysis – failure mode and effect analysis and value stream mapping (PFDA-FMEA-VSM). This novel integrated method is intended to improve the manner to perform the NPDP-RA for stakeholders. A practical example is presented to demonstrate the proposed integration of PFDA-FMEA-VSM for stakeholders at NPDP of electronic devices project.