Early Phases Of Development Research Articles

Learnings from developing a custom virtual assembly environment for mountability issues of cooling cabinets

AbstractVarious industries use computer simulation for verifying product properties in early phases of development. Traditionally, such properties include the stability of mechanical structures or the efficiency of aircraft turbines. More recently, research also focuses on the mountability of industrial products using virtual assembly. While research on virtual assembly already started in the mid-1990s, the applicability in different industries remains largely unclear today. To advance the state-of-the-art, in this paper we present learnings from developing a virtual assembly environment for cooling cabinets.

Enabling the design for circularity through circularity measures: breaking down the R-strategies into useful design measures

AbstractImplementing a product design that incorporates circular economy aspects is a highly intricate task. Its complexity stems from various aspects, such as the interdependent solution space and the challenge to evaluate the impact of circular design in early development phases. To facilitate informed decision-making, a support system is necessary that integrates product-oriented circular measures, and derives their effect on the product's design and its circularity. We present an approach for such a support system, including its evaluation on the design of an automotive center console.

A conceptual MCDA-based framework for machine learning algorithm selection in the early phase of product development

AbstractDespite the potential to enhance efficiency and improve quality, AI methods are not widely adopted in the context of product development due to the need for specialized applications. The necessary identification of a suitable machine learning (ML) algorithm requires expert knowledge, often lacking in companies. Therefore, a concept based on a multi-criteria decision analysis is applied, enabling the identification of a suitable ML algorithm for tasks in the early phase of product development. The application and resulting advantages of the concept are presented through a practical example.

A Novel Mouse Model of Physical Inactivity to Study the Role of Mitochondria in Chronic Kidney Disease

Chronic kidney disease (CKD) is a progressive disorder marked by a decline in kidney function. It is thought that a decline in mitochondrial function likely contributes to the pathogenesis of CKD, but the detailed mechanisms remain unclear. This gap in knowledge is contributed by a lack of a murine CKD model that does not rely on injury, toxin, or gene deletion to induce reduced kidney function. In humans, obesity and sedentary behavior strongly contribute to the development of CKD. The aim of the study was to employ small mouse cage (SMC) housing, a novel mouse physical inactivity model that was recently developed in our lab, and test whether it can be used to reliably induce CKD in mice. Wildtype C57BL6J mice were given standard chow or Western high-fat diet (HFD) with or without SMC intervention for 24 weeks to examine the effects of HFD and SMC on glomerular filtration rate (GFR) and respiration on isolated mitochondria from kidney cortex. Although the GFR values of the HFD+SMC group trended higher than other groups, the kidney function was still considered to be normal. Neither HFD nor HFD+SMC group had developed CKD, but mitochondrial respiration of SMC+HFD (1512.64 ± 77.86 pmol·sec−1·mgprotein−1) was significantly greater than that of the HFD-only group (1307.82 ± 79.08 pmol·sec−1·mgprotein−1, p = 0.0017) or the standard chow group (1104.69 ±143.12 pmol·sec−1·mgprotein−1, p = 0.0314. One-way ANOVA followed by Tukey’s test for multiple comparisons). Increased mitochondrial respiration may suggest a hyperfiltration-induced stress response, as commonly observed in the early stages of CKD in humans, and/or an increase in respiration to compensate for reduced effciency of oxidative phosphorylation. We interpret these data to mean that HFD and HFD+SMC are beginning to show adaptations that are in an early phase of CKD development. However, this model requires further optimization to yield the CKD phenotype. Therefore, we intend to further adapt the intervention to induce symptomatic CKD. We envision that developing preclinical models of CKD will help better elucidate its molecular mechanism and identify therapeutic targets for treating CKD in human patients. DK107397, DK127979. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Specificity of early motor unit adaptations with resistive exercise training.

After exposure of the human body to resistive exercise, the force-generation capacity of the trained muscles increases significantly. Despite decades of research, the neural and muscular stimuli that initiate these changes in muscle force are not yet fully understood. The study of these adaptations is further complicated by the fact that the changes may be partly specific to the training task. For example, short-term strength training does not always influence the neural drive to muscles during the early phase (<100ms) of force development in rapid isometric contractions. Here we discuss some of the studies that have investigated neuromuscular adaptations underlying changes in maximal force and rate of force development produced by different strength training interventions, with a focus on changes observed at the level of spinal motor neurons. We discuss the different motor unit adjustments needed to increase force or speed, and the specificity of some of the adaptations elicited by differences in the training tasks.

Paralympic Versus Olympic Canoe Sprint: Comprehension of the Development Trajectory of the Kayak 200 Meters.

Improvements in race times for male and female Para canoe athletes across different sports classes have led to a reduction in relative differences between classes over time. However, there is a lack of research examining the comparative developmental trajectories between high-performance Paralympic (PCS) and Olympic (OCS) canoe sprint. In this study, we compared the developmental trajectories of 200-meter kayak performances among PCS and OCS athletes. In total, we analyzed 628 race results obtained from public online databases, for nine competitions between 2015 and 2023. Race times were reduced over the years except in specific sports classes (KL3-M, K1-M, and K1-F; KL: Kayak Level, M: male, F: female), with a poor positive correlation (r = 0.17 to 0.33) between time and the years. For the remaining sports classes, these correlations ranged from poor to fair (r = -0.58 to -0.13). OCS K1 athletes outperformed their Paralympic counterparts. Among Paralympic classes, KL1 had slower times than KL2 and KL3 (p ≤ .05), with KL2 times significantly lower than KL3 in the female category. OCS athletes exhibited less variability in race times compared to PCS athletes. In the male category, there were no significant differences in the coefficients of variation (CV) and amplitude of race times between sport classes, except for KL1-M, which had a larger CV than K1 (p ≤ .05). In the female category, the CV and amplitude of race times were significantly higher in KL1-F compared to KL3-F and K1-F. OCS times remained stable from 2015, with KL3-M following a similar trend. PCS displayed greater race time variability, particularly in higher impairment classes, notably KL1. This underscores the existence of distinct developmental stages within the canoe sprint modality, particularly emphasizing the early developmental phase of KL1. It also provides valuable insights for coaches and sports selection, especially concerning athletes with more severe impairments, including those in Rehabilitation Centers and during athlete recruitment.

Assessment of an auto-routing method for topology generation of aircraft power supply systems

During early phases of aircraft development, overall systems design is performed to estimate relevant system design parameters such as mass, power consumption, and compliance with architectural requirements (redundancy). The GeneSys software framework has been developed for parametric modeling of aircraft on-board systems for overall systems design. To this end, model-based architecture definition, topology generation (components positioning and connections routing), and system sizing are conducted. The topology generation is currently performed using design templates containing knowledge-based heuristics derived from systems topologies of existing aircraft. However, using such design templates limits their generic application to novel aircraft models because exceptions for geometric differences between these models need to be implemented. This especially applies to the topology generation of power supply systems (electric, hydraulic) due to their high number of interfaces to consumer systems. To overcome these limitations, an automated routing method is presented in this paper as a generic approach for topology generation. With this method, the system topology is generated based on a defined routing network, which comprises areas of the aircraft for allowed components positioning and connections routing. Using Dijkstra’s algorithm, the shortest path connections are found within the established routing network. Furthermore, boundary conditions for routing, for instance adding a cost function for power segregation, can be defined. An assessment of the automated routing method applied on the electric power supply system is performed using qualitative parameters such as the capability to adapt the routing network. Quantitative parameters like cable length and system mass are assessed as well.

A rationale for the Right-to-Development climate policy stance?

We present a formal model that analyzes the trade-offs between environmental policy and economic growth in a developing economy. The adoption of restrictive environmental policies limits the use of abundant fossil energy resources, which may slow down economic development and thus violate the Right-to-Development. If faster economic growth allows a country to grow out of pollution sooner, less stringent policies are good for growth and even for the environment, having adopted a long-term horizon. Accounting for a ceiling on cumulative emissions can reinforce the argument by providing an additional rationale to phase out pollution. One assumption is crucial for the argument to hold: polluting fossil energy is an essential input over the early phase of economic development, but not in the later phases. Such a discontinuity could result from structural change. We provide empirical evidence for the plausibility of a discontinuity in the elasticity of carbon dioxide emissions with respect to aggregate output, using cross country data, even if it does not appear to be as strong as assumed in the model economy.

Correlation between autistic traits and brain functional connectivity in preschoolers with autism spectrum disorder: a resting state MEG study.

Neurophysiological studies recognized that Autism Spectrum Disorder (ASD) is associated with altered patterns of over- and under-connectivity. However, little is known about network organization in children with ASD in the early phases of development and its correlation with the severity of core autistic features. The present study aimed at investigating the association between brain connectivity derived from MEG signals and severity of ASD traits measured with different diagnostic clinical scales, in a sample of 16 children with ASD aged 2 to 6years. A significant correlation emerged between connectivity strength in cortical brain areas implicated in several resting state networks (Default mode, Central executive, Salience, Visual and Sensorimotor) and the severity of communication anomalies, social interaction problems, social affect problems, and repetitive behaviors. Seed analysis revealed that this pattern of correlation was mainly caused by global rather than local effects. The present evidence suggests that altered connectivity strength in several resting state networks is related to clinical features and may contribute to neurofunctional correlates of ASD. Future studies implementing the same method on a wider and stratified sample may further support functional connectivity as a possible biomarker of the condition.

Reprogramming fibroblast into human iBlastoids.

The study of early human embryogenesis has relied on the use of blastocysts donated to research or simple stem cell culture systems such as pluripotent and trophoblast stem cells, which have been seminal in shedding light on many key developmental processes. However, simple culture systems lack the necessary complexity to adequately model the spatiotemporal, cellular and molecular dynamics occurring during the early phases of embryonic development. As such, an in vitro model of the human blastocyst is advantageous in many aspects to decipher human embryogenesis. Here we describe a step-by-step protocol for the generation of induced blastoids (iBlastoids), an in vitro integrated model of the human blastocyst derived via somatic reprogramming. This protocol details the workflow for reprogramming of human dermal fibroblasts and subsequent generation of iBlastoids using the reprogramming intermediates, which together takes ~27 days (21 days for reprogramming and 6 days for iBlastoid generation). We also discuss several characterization/functional assays that can be used on the iBlastoids. We believe that a person trained in cell culture with ~1 year of experience with human somatic cell and reprogramming/cell differentiation assays would be able to perform this protocol. In short, the iBlastoids present an alternative tool as a model to the blastocyst to facilitate the scientific community in the exploration of early human development.

Evaluation of the Indoor Efficacy of Various Foliar-Applied Herbicides on Sicyos angulatus Seedlings

Sicyos angulatus is an increasingly pervasive alien species, has been identified as a significant contributor to the deterioration of biodiversity within the northern quadrant of the china. The objective of this investigation was to assess the efficacy of seven herbicides in suppressing the growth of S. angulatus seedlings, specifically targeting the early developmental phase. The application of the herbicides took place during the trileaf stage, a critical growth period. The herbicides under scrutiny included Prometryn, Thifensulfuron methyl, Nicosulfuron, Mesotrione, Bentazone, Imazethapyr, and a composite of Dicamba-Glyphosate-Triclopyr, with water serving as the control. To ensure consistent application and growth conditions, calibrated sprayers and standardized soil conditions were utilized. Data collection encompassed observations of toxicity, measurements of fresh weight, assessment of fresh weight effect, and the implementation of ANOVA to discern treatment variances, facilitating graphical comparison. The results indicated that all evaluated agents exhibited inhibitory effects on the seedlings. The Bentazone treatment exhibited an excellent control effect, with a fresh weight inhibition rate exceeding 95% on S. angulatus seedlings. Similarly, the Mesotrione and Dicamba-Glyphosate-Triclopy treatments demonstrated a good control effect, resulting in a fresh weight inhibition rate of over 85%. When treated with Prometryn, the S. angulatus seedlings displayed a moderate control effect, as indicated by a fresh weightinhibition rate exceeding 55%. However, Thifensulfuron methyl, Nicosulfuron, andImazethapyr showed poor control effects with a fresh weight inhibition rate below 55%. In light of these findings, it is posited that Mesotrione, Bentazone, and the Dicamba-Glyphosate-Triclopyr blend manifest as viable candidates for the prophylaxis and remediation of the early-stage growth of S. angulatus. Paramount to the study's conclusions is the lack of statistically significant disparity in the suppression outcomes across the concentration spectrum of the aforementioned efficacious agents. Hence, when juxtaposing ecotoxicological ramifications and economic considerations, the adoption of a concentration commensurate with the standard unitary dosage is proposed.

A non-canonical BZR/BES transcription factor regulates the development of haploid reproductive organs in Marchantia polymorpha.

Gametogenesis, which is essential to the sexual reproductive system, has drastically changed during plant evolution. Bryophytes, lycophytes and ferns develop reproductive organs called gametangia-antheridia and archegonia for sperm and egg production, respectively. However, the molecular mechanism of early gametangium development remains unclear. Here we identified a 'non-canonical' type of BZR/BES transcription factor, MpBZR3, as a regulator of gametangium development in a model bryophyte, Marchantia polymorpha. Interestingly, overexpression of MpBZR3 induced ectopic gametangia. Genetic analysis revealed that MpBZR3 promotes the early phase of antheridium development in male plants. By contrast, MpBZR3 is required for the late phase of archegonium development in female plants. We demonstrate that MpBZR3 is necessary for the successful development of both antheridia and archegonia but functions in a different manner between the two sexes. Together, the functional specialization of this 'non-canonical' type of BZR/BES member may have contributed to the evolution of reproductive systems.

The evolution of larvae in temnospondyls and the stepwise origin of amphibian metamorphosis.

The question of what the ancient life cycle of tetrapods was like forms a key component in understanding the origin of land vertebrates. The existence of distinct larval forms, as exemplified by many lissamphibians, and their transformation into adults is an important aspect in this field. The temnospondyls, the largest clade of Palaeozoic-Mesozoic non-amniote tetrapods, covered a wide ecomorphological range from fully aquatic to terrestrial taxa. In various species, rich ontogenetic data have accumulated over the past 130 years, permitting the study of early phases of temnospondyl development. In temnospondyls, eight ontogenetic phases have been identified in which the skeleton formed. In branchiosaurids and the eryopiform Sclerocephalus, large parts of the ossification sequence are now known. Most taxa in which small specimens are preserved had aquatic larvae with external gills that superficially resemble larval salamanders. In the edopoids, dvinosaurs, and eryopiforms, the larvae developed slowly, with incompletely ossified axial and appendicular skeletons, but possessed a fast-developing dermal skull with strong teeth. Irrespective of adult terrestriality or a fully aquatic life, there was no drastic transformation during later ontogeny, but a slow and steady acquisition of adult features. In dissorophoids, the limbs developed at a much faster pace, whereas skull formation was slowed down, especially in the amphibamiforms, and culminating in the neotenic Branchiosauridae. In the zatracheid Acanthostomatops, slow but profound transformation led to a fully terrestrial adult. The basal dissorophoid Stegops retained rapid development of dermal skull bones and established a fully dentigerous, strongly ossified palate early. In Micromelerpeton, formation of the last skull bones was slightly delayed and metamorphosis remained a long and steady phase of morphological transformations. In amphibamiforms, metamorphosis became more drastic, with an increasing number of events packed into a short phase of ontogeny. This is exemplified by Apateon, Platyrhinops, and Amphibamus in which this condensation was maximised. We distinguish three different types of metamorphosis (morphological, ecological and drastic) that evolved cumulatively in early tetrapods and within temnospondyls.

Prognostic model and failure mechanisms of steam generators in Sodium-Cooled fast reactors

This paper presents a prognostic model for sodium-cooled fast reactor (SFR) steam generators (SGs). The purpose of the model is to estimate the remaining useful life of SFR SGs and thus to support the decision-making of autonomous control. SFR SGs are of great interest for plant integrity due to their harsh operation environment. They operate at higher temperatures and higher coolant-to-steam pressure differences than those of current light water reactors (LWR). The severity of the SFR SG failure consequences, which include water-sodium contact, is another reason. Understanding its failure mechanisms is important for the development of its prognostic model. Based on our literature review and physics-based analysis, we concluded that creep would be a dominant degradation mode of SFR SGs due to SFR’s high-temperature and high-pressure environment. Thus, creep is the focus of the prognostic model. Various other failure modes were also investigated in this study. The mechanical fatigue due to flow-induced vibration is usually observed in early developmental phases and would not be an important issue during normal operation. The thermal fatigue due to thermal stripping is occasionally observed in other components in SFRs but does not affect SG integrity. Pure water stress corrosive crack, fretting, and so on are commonly observed in LWR SGs but are significantly less important in SFR SGs because of the high temperatures, high pressure differences, and chemical properties of liquid sodium. Based on these investigations, a prognostic model focusing on creep failures was developed. It estimates the failure probability profile by sampling the Larson-Miller parameter (LMP) and temperature and associated uncertainties through Monte Carlo methods. Two case studies were presented. The first one demonstrated the model’s capability to calculate the failure probability for a new specimen within a given time. If the tube is working under temperatures of 500C ± 3 and pressures of 15.2 MPa, which leads to LMP of 20,100 ± 50, the failure probabilities within 50, 70, and 90 years are approximately 0.1 %, 3.2 %, and 17.5 %. The second demonstrated how adjusting the workload can help to protect the integrity of the component. For an old tube reaching 99 % of its lifespan, continuing to run at temperatures of 500C ± 3 and LMP of 20,100 ± 50 leads to a failure probability of about 29.0 % within a year. If the temperature is reduced by 5C, the failure probability can be reduced to 2.5 %, and, if the pressure is also reduced such that the LMP is increased by 100, the failure probability can further be reduced to 0.12 %.

Associations between resilience to weaning stress and startle response in nursery age gilts

Resilience is the capacity of animals to return quickly to their pre-stress status following a disturbance, including social, physical, and/or disease challenges. In modern farming, where there are many stressors, resilience is crucial for pigs because it affects their welfare and production. The goal of the study was to assess whether behavioral response to an auditory stimulus during a startle test (acute stress) differed between pigs designated at weaning (27 +/- 2d of age) as stress-resilient (SR) or stress-vulnerable (SV). Blood samples were collected from female piglets (n = 170) from 26 litters surrounding weaning at multiple time points. Using serum cortisol levels from these samples, two female pigs from each litter (n = 52) were classified as either SR (n = 26) or SV (n = 26) and used for the startle test. The startle test was conducted when pigs were 7wk-of-age while they were housed in the nursery room and recordings were captured utilizing cameras positioned on the ceiling. We assessed startle magnitude score (SM) and time to resume home pen behavior as indicators of the pigs’ behavioral responses. In addition to stress resilience designation, pigs’ relaxed-tense score (RT), orientation to stimulus (OS), and pen position were also observed which may affect startle response. Our data suggest no relationship between behavioral response to an auditory startle test and resilience or vulnerability to weaning stress. The difference in the type of stressors needs to be considered as an acute, simple auditory stimulus was used for the startle test and a longer-lasting, multi-modal weaning stress was used for initial resilience designation. However, the startle test could be a relatively easy way to assess the fearfulness of pigs on farms, as it requires no training of pigs and can be conducted in the home pen, but further methodological improvement is required. Though our results did not support a clear connection between a behavioral fear response and physiological stress resilience, examining the resilience of pigs during their early developmental phases using behavioral markers is worthwhile. Early detection of non-resilient animals could offer the opportunity to implement more effective management strategies beginning earlier in life when pigs might be more vulnerable to stressors or the effects more long-lasting, thereby improving the welfare of pigs. Furthermore, it facilitates the selection of robust animals for future breeding. Further research is required to identify behavioral traits clearly indicative of stress resilience.

Reactive Oxygen Species Modulation in the Current Landscape of Anticancer Therapies.

Significance: Reactive oxygen species (ROS) are generated during mitochondrial oxidative metabolism, and are tightly controlled through homeostatic mechanisms to maintain intracellular redox, regulating growth and proliferation in healthy cells. However, ROS production is perturbed in cancers where abnormal accumulation of ROS leads to oxidative stress and genomic instability, triggering oncogenic signaling pathways on one hand, while increasing oxidative damage and triggering ROS-dependent death signaling on the other. Recent Advances: Our review illuminates how critical interactions between ROS and oncogenic signaling, the tumor microenvironment, and DNA damage response (DDR) pathways have led to interest in ROS modulation as a means of enhancing existing anticancer strategies and developing new therapeutic opportunities. Critical Issues: ROS equilibrium exists via a delicate balance of pro-oxidant and antioxidant species within cells. "Antioxidant" approaches have been explored mainly in the form of chemoprevention, but there is insufficient evidence to advocate its routine application. More progress has been made via the "pro-oxidant" approach of targeting cancer vulnerabilities and inducing oxidative stress. Various therapeutic modalities have employed this approach, including direct ROS-inducing agents, chemotherapy, targeted therapies, DDR therapies, radiotherapy, and immunotherapy. Finally, emerging delivery systems such as "nanosensitizers" as radiotherapy enhancers are currently in development. Future Directions: While approaches designed to induce ROS have shown considerable promise in selectively targeting cancer cells and dealing with resistance to conventional therapies, most are still in early phases of development and challenges remain. Further research should endeavor to refine treatment strategies, optimize drug combinations, and identify predictive biomarkers of ROS-based cancer therapies.

Online Health Navigation: Study Case of @leonavictoria_ahligizi’s Instagram's Impact on Information Fulfilment for Stunting Prevention

This study investigates the impact of Instagram content on maternal attitudes and practices pertaining to child nutrition and the prevention of stunting. The study utilizes case study approach to analyze the Instagram account @leonavictoria_ahligizi on Milhinhos's theoretical framework. The research assesses the content of the account in terms of its relevance, accuracy, value, understandability, discoverability, and consistency. The analysis is contingent upon Instagram's capacity to address a variety of informational requirements, including cognitive, affective, personal integration, social integration, and tension release. The findings illustrate a statistically significant influence of Instagram in improving the dietary practices of mothers of preventing stunting in children. The findings analysis, utilizing SmartPLS 4. 0, revealed a significant association between Instagram content and users' understanding and dietary habits, as evidenced by a path coefficient of 0. 729 This suggests a substantial impact on the satisfaction of information needs. The demographic data indicates that the majority of the participants are well-educated mothers between the ages of 25 and 34, who are actively involved in consuming the content with the aim of enhancing their children's dietary habits. The material presented on @leonavictoria_ahligizi not only serves to increase knowledge and understanding but also facilitates the practical application of nutritional regimens essential for the early developmental phases of children. This highlights the significant importance of customized, trustworthy, and practical social media material in addressing child stunting and advancing public health by promoting informed dietary habits. The incorporation of social media platforms into health education initiatives signifies a substantial advancement in efforts to combat worldwide malnutrition and improve the health outcomes of communities.

The Conventional and Breakthrough Tool for the Study of L-Glutamate Transporters.

In our recent report, we clarified the direct interaction between the excitatory amino acid transporter (EAAT) 1/2 and polyunsaturated fatty acids (PUFAs) by applying electrophysiological and molecular biological techniques to Xenopus oocytes. Xenopus oocytes have a long history of use in the scientific field, but they are still attractive experimental systems for neuropharmacological studies. We will therefore summarize the pharmacological significance, advantages (especially in the study of EAAT2), and experimental techniques that can be applied to Xenopus oocytes; our new findings concerning L-glutamate (L-Glu) transporters and PUFAs; and the significant outcomes of our data. The data obtained from electrophysiological and molecular biological studies of Xenopus oocytes have provided us with further important questions, such as whether or not some PUFAs can modulate EAATs as allosteric modulators and to what extent docosahexaenoic acid (DHA) affects neurotransmission and thereby affects brain functions. Xenopus oocytes have great advantages in the studies about the interactions between molecules and functional proteins, especially in the case when the expression levels of the proteins are small in cell culture systems without transfections. These are also proper to study the mechanisms underlying the interactions. Based on the data collected in Xenopus oocyte experiments, we can proceed to the next step, i.e., the physiological roles of the compounds and their significances. In the case of EAAT2, the effects on the neurotransmission should be examined by electrophysiological approach using acute brain slices. For new drug development, pharmacokinetics pharmacodynamics (PKPD) data and blood brain barrier (BBB) penetration data are also necessary. In order not to miss the promising candidate compounds at the primary stages of drug development, we should reconsider using Xenopus oocytes in the early phase of drug development.

Early Validation and Verification of System Behaviour in Model-based Systems Engineering: A Systematic Literature Review

In the Systems Engineering (SE) domain there has been a paradigm shift from document-based to model-based system development artefacts; in fact, new methodologies are emerging to meet the increasing complexity of current systems and the corresponding growing need of digital workflows. In this regard, Model-Based Systems Engineering (MBSE) is considered as a key enabler by many central players of the SE community. MBSE has reached an adequate level of maturity, and there exist documented success stories in its adoption in industry. In particular, one significant benefit of utilising MBSE when compared to the traditional manual and document-centric workflows is that models are available from early phases of systems development; these enable a multitude of analyses prior any implementation effort together with other relevant capabilities, like the automation of development tasks. Nonetheless, it is noticeable there is a lack of a common understanding for how formal analyses for the verification and validation (V&amp;V) of systems behaviour, specifically in the early phases of development, could be placed in an MBSE setting. In this article, we report on the planning, execution, and results of a systematic literature review regarding the early V&amp;V of systems behaviour in the context of model-based systems engineering. The review aims to provide a structured representation of the state of the art with respect to motivations, proposed solutions, and limitations. From an initial set of potentially relevant 701 peer-reviewed publications we selected 149 primary studies, which we analysed according to a rigorous data extraction, analysis, and synthesis process. Based on our results, early V&amp;V has usually the goal of checking the quality of a system design to avoid discovering flaws when parts are being concretely realised; SysML is a de facto standard for describing the system under study, while the solutions for the analyses tend to be varied; also V&amp;V analyses tend to target varied properties with a slight predominance of functional concerns, and following the variation mentioned so far the proposed solutions are largely context specific; the proposed approaches are usually presented without explicit limitations, while when limitations are discussed, readiness of the solutions, handling of analyses simplifications/assumptions, and languages/tools integration are among the most frequently mentioned issues. Based on the survey results and the standard SE practices, we discuss how the current state-of-the-art MBSE supports early V&amp;V of systems behaviour with a special focus on industrial adoption and identify relevant challenges to be researched further.

Analysis of human errors in human-autonomy collaboration in autonomous ships operations through shore control experimental data

Human-autonomy collaboration plays a pivotal role in the development of Maritime autonomous surface ships (MASS), as Shore control center (SCC) operators may engage in the control loop by directly operating the MASS, or, in the supervisory loop, monitoring the MASS and taking over control when needed. Thus, effective human performance during takeover control and operation is crucial for the safety of MASS operations. However, since the MASS is still in the early phase of development, the mechanism of human errors is unknown, and the data on human-autonomy collaborative operation is scarce. Human reliability analysis (HRA) aims to assess human errors qualitatively and quantitatively, and is widely used in various complex systems to help safety analysis. This study is dedicated to incorporating advanced HRA methods elements to identify and quantify human errors during taking over control and operation of a MASS in collision avoidance scenarios. It presents virtual experimental results, combined with theoretical human error identification and assessment methods. At first, we apply the Human-System Interaction in Autonomy (H-SIA) method to identify potential human errors; secondly, we identify relevant Performance Shaping Factors (PSFs) including Experience, Boredom, Task complexity, Available time and Pre-warning, and performance measures of the human errors, and implement them in the virtual experiment based on a full-scale autonomous ferry research vessel called milliAmpere2. Finally, we build a Bayesian Network (BN) to present causal and probabilistic relationships between PSFs and human errors through experimental data. The results show that available time has the highest impact on takeover performance of operators, followed by task complexity and pre-warning. Boredom does not present a significant sole impact unless combined with available time. Experience does not show a significant impact on human performance. In addition to the relevance of the human errors analysis to the safe development and operational design of MASS, the developed method benefits other human-autonomy collaborative systems. The developed BN model shows adaptability to assess human error probabilities, and the practical significance of integrating experimental data into the existing HRA methodologies for complex systems.