Theoretical and experimental study of a stable state adjustable nonlinear energy sink

Due to high sensitivity to the changes in external excitation intensity, the implementation of nonlinear energy sinks (NESs) have been greatly limited in practical applications. This study presents a stable state adjustable NES (SA-NES) structure. By adjusting the structural geometric relationship, the SA-NES structure can easily switch its stable state among monostable, bistable, and tristable. The governing equation of the coupled system is obtained by Hamilton's principle. The approximate analytical solution is obtained by the harmonic balance method, and the slow invariant manifold is obtained complexification-averaging method, which are validated through numerical analysis. Through theoretical analysis and experimental validation, the dynamic response of the SA-NES and vibration reduction performance are studied under different levels of excitations. The obtained results show that the designed SA-NES can effectively suppress the vibration under different level excitation intensities. It is also shown that the SA-NES structure can be adjusted to the monostable state, and the vibration of the linear oscillator can be effectively suppressed by the strong modulation response under a certain excitation intensity. When the excitation intensity is weak or strong, the SA-NES can be adjusted to the bistable state and the tristable state, respectively, thus effectively suppressing the vibration through chaotic inter-well oscillation. This study reveals the vibration suppression mechanism of the SA-NES, and introduces a new NES configuration to suppress different levels of engineering excitations

Topology optimization for additive manufacturing of CFRP structures

Combining design optimization and additive manufacturing (AM) enables the full exploitation of the potential for heightening the performance of carbon fiber reinforced plastic (CFRP) structures. This study simultaneously conducts topology optimization and fiber path design by employing the radial basis function (RBF) based level set function (LSF). Fiber paths are determined instinctively for the inherent advantages of the LSF, and fiber orientations are parameterized accordingly. Manufacturing drawbacks such as gaps and overlaps can be avoided by introducing a fast-marching method. To verify the effectiveness of the optimization method, three groups of optimized and empirical designs are fabricated by the AM technique, respectively, and the experimental tests are further carried out. Finite element (FE) models are also reconstructed based on the printing schemes, and then the FE simulation is validated by the experimental tests. With the proposed optimization method, stiffnesses for all three groups of the optimal samples are significantly improved compared with the empirical counterparts. The FE modeling technique is capable of reproducing the experimental results. This study paves a new way to develop an integrated framework of optimization, additive manufacturing, experimentation, and validation to deliver high-performance CFRP structures

Molecular mechanism of androgen receptor mutation in multigenerational mild androgen insensitivity syndrome.

OBJECTIVE: Androgen insensitivity syndrome (AIS) due to androgen receptor (AR) mutations creates a spectrum of clinical presentations based on residual AR function with the mildest impairment creating mild AIS (MAIS) whose undefined molecular mechanism and subtle clinical features leave it less understood and underdiagnosed. DESIGN: In silico modeling and in vitro androgen bioassay of the mutated AR are used to identify its structural and physiological mechanism. Clinical features and responses to high-dose testosterone treatment of three cases of MAIS across a six-generation family pedigree are described. METHODS: Structural and dynamic in silico molecular modeling and in vitro yeast-based androgen bioassays of the mutant AR are employed. Three cases of MAIS with consistent (gynecomastia and micropenis) and variable (infertility) clinical features across generations are reported, and the effects of high-dose testosterone treatment are studied. RESULTS: The missense AR exon 8 mutation (nucleotide aga → gga, p.R872G arginine to glycine), known to cause an increased ligand dissociation rate in mutant AR in binding assays, was analyzed. Modeling shows that the mutation weakens the closure energy of the 'lid' of the ligand-binding pocket, allowing easier ligand dissociation from the binding site but with unimpaired in vitro androgen bioactivity. High-dose testosterone treatment for 3 years in one young man caused increased virilization and height growth but was ineffective for treating micropenis. Genetic counseling allowed effective prediction of MAIS risks in progeny for carrier and noncarrier sisters. CONCLUSIONS: The differential diagnosis and clinical management of MAIS is reviewed. The novel molecular mechanism of an AR ligand-binding domain mutation in MAIS may be present in other cases of MAIS

India

The demand-supply gap in infrastructure became evident with the initiation of economic reforms in 1990. There are complex political arrangements around infrastructure in India's 29 states and seven union territories. Growth in the provision of infrastructure has grown markedly in the past 30 or so years. Two cases are considered. The first case concerns solid municipal waste management. In the mid-1990s, "Diamond City? (pseudonym) faced a health crisis because of poor management of municipal solid waste. Since then, municipal solid waste management became a focus area of improvement for the urban local body of Diamond City (ULB-CD). ULB-CD started using an "unbundling? approach for MSW management. By contrast, "BEATLE City? (pseudonym) is the capital of a north-eastern state in India, which has witnessed a rapid increase in population since 2005 and has become the largest metropolis in the northeast of the country. Urbanization has been the increased generation of municipal solid waste. The municipal corporation of BEATLE (ULB-BEATLE) is an urban local body responsible for municipal solid waste management. Deficiencies across all components of the municipal solid waste supply chain were evident: primary collection and transportation, secondary transportation, processing, and disposal. There were limited door-to-door collections of municipal solid waste, lack of secondary collection points and processing facilities, and unscientific dumping of municipal solid waste in low-lying areas. ULB-BEATLE used a public-private partnership that did little to improve the situation

Enhancing Minority Sentiment Classification in Gastronomy Tourism: A Hybrid Sentiment Analysis Framework With Data Augmentation, Feature Engineering and Business Intelligence

The gastronomy tourism industry plays an important role in boosting local economies, enhancing the travel experience, and preserving culinary traditions unique to specific places. In this context, comprehending customer sentiments is of paramount importance for business decision-making, menu choice offerings, marketing strategies, and customer service improvements. Traditional sentiment analysis methods in gastronomy tourism tend to be time-consuming, prone to human error, and influenced by subjectivity. Furthermore, the absence of an effective visualization strategy hampers the reliability of sentiment analysis efforts. Compounding this, the data collected also often lacked balance across sentiment classes, making it challenging to predict minority sentiments accurately. To address these challenges, our research introduces a hybrid approach, combining various lexicon-based sentiment and emotional analysis algorithms, thereby enhancing the reliability of customer review analysis in the gastronomy tourism sector. Subsequently, we optimize machine learning sentiment classification by employing data augmentation in conjunction with feature engineering strategies, to improve the recognition of minority sentiment classes. Additionally, we present a comprehensive business intelligence and visualization solution that is personalized for the gastronomy tourism industry in Sarawak and offers real-time sentiment visualization. The optimization of sentiment classification, achieved through the integration of synonym augmentation and n-gram feature engineering in conjunction with kNN classifiers, has yielded impressive results. This approach attains optimal classification performance, boasting an accuracy rate of 0.98, a F1-score and a ROC-AUC score of 0.99. Notably, this methodology significantly enhances the recognition of minority sentiment classes within the dataset, addressing the main challenges in this research

Activity-related pain and sensitization predict within- and between-person pain experience in people with knee osteoarthritis: An ecological momentary assessment study.

BACKGROUND AND OBJECTIVES: Knee Osteoarthritis (OA) is a prevalent musculoskeletal condition that often results in pain and disability. Determining factors predicting variability in pain experience is critical to improving clinical outcomes. Underlying pain sensitization and its clinical manifestations, such as activity-related pain, may better predict the knee OA pain experience. This study aimed to determine whether Quantitative Sensory Testing (QST) derived sensitization measures and activity-related pain predict knee OA pain experiences collected via smartphone ecological momentary assessment (EMA). DESIGN: Individuals with knee OA were recruited from an urban community in New Zealand. Those eligible to participate underwent baseline QST with clinical measures of activity-related pain also being collected. The knee OA pain experience was collected via smartphone EMA three times daily for two weeks. Mixed effects location scale models were developed using a multilevel modelling approach. RESULTS: Eighty-six participants with knee OA participated in the study. Mean age was 67.3 years, with most of the participants being female (64%) and New Zealand European (90.6%). Activity-related pain predicted worse and more variable pain intensity, pain interference, and bothersomeness outcomes within and between individuals with knee OA. Widespread cold hyperalgesia and local mechanical hyperalgesia were shown to predict higher within-person variability in pain intensity and pain interference respectively, while mechanical temporal summation predicted less within-person variability in pain intensity and interference. DISCUSSION: Those demonstrating activity-related pain and sensitization could be at risk of experiencing worse and more variable knee OA pain in the subsequent weeks. Testing for sensitization in clinical practice could therefore identify those at greatest risk of higher and more variable knee OA pain experiences and in greatest need of treatment. Larger validation studies are required, which include individuals with more severe knee OA

Benefit–Risk Assessment in Sport and Recreation: Historical Development and Review of AS ISO 4980:2023

Risk management involves thinking about what could happen if someone is exposed to a hazard and the likelihood of this event. The vast majority of standards relating to risk management were written in the context of Occupational Health and Safety, as well as Work Health and Safety with the aim of eliminating all risks. In 2023 Standards, Australia published AS ISO 4980:2023: `Benefit-risk assessment for sport and recreational facilities, activities and equipment’. This standard provides a tool for applying risk management in the context of sport and recreation. AS ISO 4980:2023 is a departure from the traditional view of risk management standards in that it presents a view of risk that is not limited to viewing risk only as negative, but rather balances positive benefits with negative risks within the sport and recreation industry. This standard is also different in that it is based specifically on risk to sport and recreational users and not to employees and employers. The benefit that risk provides in the context of sports and recreational activities is placed on an equal footing with the traditional method of assessing risk. There is an expectation in sports and recreational activities that the user is making an implicit trade-off between the benefits and the inherent risks of the activity, including the potential for harm. This implied expectation is that exposure to risk can be positive. Positive risk and learning from making mistakes are not restricted to childhood development where graduated challenges are used but extend throughout our entire life. The goal of this paper is to draw public attention to the new and different perspective of risk on which AS ISO 4980:2023 is based and to provide an understanding of the concept of benefit–risk assessment. The implications of viewing non-workplace risk in a balanced way are discussed.</jats:p

Uncertainty in Automated Ontology Matching: Lessons from an Empirical Evaluation

Data integration is considered a classic research field and a pressing need within the information science community. Ontologies play a critical role in such processes by providing well-consolidated support to link and semantically integrate datasets via interoperability. This paper approaches data integration from an application perspective by looking at ontology matching techniques. As the manual matching of different sources of information becomes unrealistic once the system scales up, the automation of the matching process becomes a compelling need. Therefore, we have conducted experiments on actual non-semantically enriched relational data with the support of existing tools (pre-LLM technology) for automatic ontology matching from the scientific community. Even considering a relatively simple case study—i.e., the spatio–temporal alignment of macro indicators—outcomes clearly show significant uncertainty resulting from errors and inaccuracies along the automated matching process. More concretely, this paper aims to test on real-world data a bottom-up knowledge-building approach, discuss the lessons learned from the experimental results of the case study, and draw conclusions about uncertainty and uncertainty management in an automated ontology matching process. While the most common evaluation metrics clearly demonstrate the unreliability of fully automated matching solutions, properly designed semi-supervised approaches seem to be mature for more generalized application

Revolutionizing pediatric neuroblastoma treatment: unraveling new molecular targets for precision interventions.

Neuroblastoma (NB) is the most frequent solid tumor in pediatric cases, contributing to around 15% of childhood cancer-related deaths. The wide-ranging genetic, morphological, and clinical diversity within NB complicates the success of current treatment methods. Acquiring an in-depth understanding of genetic alterations implicated in the development of NB is essential for creating safer and more efficient therapies for this severe condition. Several molecular signatures are being studied as potential targets for developing new treatments for NB patients. In this article, we have examined the molecular factors and genetic irregularities, including those within insulin gene enhancer binding protein 1 (ISL1), dihydropyrimidinase-like 3 (DPYSL3), receptor tyrosine kinase-like orphan receptor 1 (ROR1) and murine double minute 2-tumor protein 53 (MDM2-P53) that play an essential role in the development of NB. A thorough summary of the molecular targeted treatments currently being studied in pre-clinical and clinical trials has been described. Recent studies of immunotherapeutic agents used in NB are also studied in this article. Moreover, we explore potential future directions to discover new targets and treatments to enhance existing therapies and ultimately improve treatment outcomes and survival rates for NB patients