Case Study Research Articles

Percutaneous self-expandable valve implantation in patients with stented pulmonary arteries: case examples.

CHDs affecting the right ventricular outflow tract often require repeated surgical or transcatheter interventions due to pulmonary insufficiency or stenosis. This study presents percutaneous implantation of large self-expanding valves in patients with complex right ventricular outflow tract anatomy after prior pulmonary branch stenting.

Assessing the subarachnoid space anatomy on clinical imaging: utilizing normal and pathology to understand compartmentalization of the subarachnoid space

BackgroundThe goal of the study is to use CT imaging in patients with aSAH to evaluate the anatomic distribution of hemorrhage and compartmentalization of subarachnoid space to investigate potential in vivo visualization of recently discovered layer named subarachnoid lymphatic-like membrane (SLYM).MethodsWe conducted a retrospective cohort study of cases with aneurysmal SAH (aSAH) at our institution between January 2015 and June 2022. Subarachnoid hemorrhage distribution into superficial and deep subarachnoid spaces was classified based on proximity to the dural or pial surfaces, respectively, as seen on multiplanar CT head.ResultsA total of 97 patients with aSAH were included. Patients with lower modified Fisher score (MFS) of 1-2 were more likely to have SAH compartmentalizing in the “deep” pial-adjacent subarachnoid space. Patients with higher MFS of 3-4 were more likely to have SAH in both “superficial” and “deep” compartments along the brainstem. There is a significant association between the severity of aSAH - quantified by the MFS - and the distribution of the blood. Patients with higher MFS scores were roughly 7.6 times (p-value = 0.049) more likely to have hemorrhage at the “Superficial” juxta-dural subarachnoid compartment when compared to those with lower MFS scores.ConclusionThis study suggests an imaging correlate to the recently discovered “SLYM”, potentially influencing aSAH compartmentalization, particularly in low-grade bleeds. While compartmentalization is limited in high grade cases, these findings warrant further investigation with advanced imaging techniques to validate this membrane’s role and potential impact on CSF flow and aSAH pathophysiology.

India’s Post-Independence Strategic Culture: A Case Study of India’s Cooperation With the United States and Russia in Military Modernization

India’s Post-Independence Strategic Culture: A Case Study of India’s Cooperation With the United States and Russia in Military Modernization

High-resolution synthetic seismic modelling: elucidating facies heterogeneity in carbonate ramp systems

Carbonate ramp systems present significant seismic interpretation challenges due to their pronounced facies heterogeneity, which frequently results in chaotic seismic outputs that obscure the underlying geological structures. The Porto Badisco Calcarenite in Salento, southern Italy, an Oligocene carbonate ramp, serves as the case study for this research, offering an analogue for understanding similar geological systems. By integrating fieldwork, laboratory analysis and MATLAB modelling, this study pioneers the use of detailed petrophysical data to construct innovative velocity models based on the velocity ranges of the different lithofacies analysed. These models distinctly illustrate the impact of facies heterogeneity on seismic velocities, providing fresh insights into acoustic impedance and variable propagation velocities across different facies constituting the carbonate ramp. Through advanced high-resolution synthetic seismic modelling conducted on carefully fine-tuned unmigrated stack sections, the research demonstrates how variations in petrophysical characteristics within measured ranges reflecting carbonate textures can dramatically alter seismic imaging. The innovative models, based on propagation velocity ranges, not only deepen the understanding of the seismic representation of lithofacies but also act as a potent tool for probing the subsurface architecture of complex carbonate systems, providing an interpretative key for the analysis of seismic images. This approach signifies a substantial advancement in seismic modelling that is aimed at refining interpretations and enhancing exploration strategies in carbonate ramp environments globally.

Load-Shifting Strategies for Cost-Effective Emission Reductions at Wastewater Facilities.

Significant hourly variation in the carbon intensity of electricity supplied to wastewater facilities introduces an opportunity to lower emissions by shifting the timing of their energy demand. This shift could be accomplished by storing wastewater, biogas from sludge digestion, or electricity from on-site biogas generation. However, the life cycle emissions and cost implications of these options are not clear. We present a multiobjective optimization framework for comparing cost- and emission-minimizing load-shifting strategies at a California case study facility with a relatively low carbon intensity grid and high spread in peak and off-peak electricity prices. We evaluate cost and emission trade-offs from the optimal flexible operation of both existing infrastructure and optimally sized energy flexibility upgrades. We estimate energy-related emission reductions of up to 9.0% with flexible operation of existing infrastructure and up to 16.8% with optimally sized storage upgrades. Only a fraction of these potential savings are realized under actual industrial energy tariffs and the EPA's recommended social cost of carbon. Energy flexibility may hold promise as a short-term emission-saving solution for the wastewater sector, but the extent of savings is heavily dependent on the cost of carbon, electricity tariffs, and emission intensity of the regional electricity grid.

Parents’ initiative in community-based support for children with intellectual and developmental disabilities: The Ahada non-profit model

ABSTRACT Background The birth of a child with an intellectual or developmental disability inherently presents challenges to parents regarding the child’s long-term future. This qualitative study examined the perceptions of parents who are kibbutz members, focusing on the non-profit organisation they established and the socioeconomic model they developed to ensure the future wellbeing of their children with intellectual and developmental disabilities. Method In-depth interviews were conducted with 12 participants and used a thematic analysis based on case study methodology. Results The socioeconomic model developed by kibbutz parents helps alleviate their concerns, but also gave rise to challenges related to kibbutz privatisation and the requirement for programs to be tailored to individual needs. The study highlighted how cooperation among families, the community, and government institutions can contribute to individual and collective solutions for people with disabilities. Conclusion These insights expand our understanding of parental social entrepreneurship within intentional communities and other contexts.

Modulating the Selective Enrichment and Depletion of Ions Using Electrorheological Fluids in Variable-Area Microchannels.

Electrorheological fluids are suspensions that are characterized by a strong functional dependence of their constitutive behavior on the local electric field. While such fluids are known to be promising in different applications of microfluidics including electrokinetic flows, their capabilities of controlling ion transport and preferential solute segregation in confined fluidic systems remain to be explored. In this work, we bring out the unique role of electrorheological fluids in orchestrating the selective enrichment and depletion of charged species in variable area microfluidic channels. Our reported phenomenon is fundamentally distinctive from other types of nonlinear electrokinetic effects previously reported, in a sense that here the dependence of the flow rheology on the electric field turns out to be the central mechanism toward orchestrating the observed nonlinear ion transport. Our results indicate exclusive features of the resulting ion concentration polarization, such as more pronounced ion concentration polarization, controlled largely by the influence of the variations in the channel cross section on the driving electrokinetic forces and the resistive viscous interactions. The underlying physical mechanism is captured aptly by a simple one-dimensional area-averaged model, and validated by full-scale three-dimensional simulations. Our illustrative case study for a converging-diverging microchannel with cross-sectionally uniform solute concentrations reveals that electrorheological effect with greater contrast between the deep and shallow region depths, greater solute concentration, and larger applied axial electric field, all acting in tandem, magnifies the solute enrichment and depletion in the respective segregation zones, bearing significant implications in analytical chemistry, bioanalysis, and beyond.

Simultaneous Optimization of Hydrogen Network with Pressure Swing Absorption Based on Evolutionary Response Surface Method

The simultaneous optimization of complex process units and hydrogen networks is a significant challenge in refinery hydrogen network integration. To address this, an evolutionary response surface-based collaborative optimization method is proposed, enabling the concurrent optimization of pressure swing adsorption (PSA) and the hydrogen network. This method develops a mechanistic model for PSA and alternates between random sampling and evolutionary response surface-based hydrogen network optimization to obtain diverse sampling points and potential optimal solutions. The PSA mechanistic model is then used to compute the accurate output parameters for the sampled points, and these parameters are incorporated into the hydrogen network optimization to obtain precise objective function values. An efficient optimization framework is presented to streamline the process. The proposed method is applied to a refinery hydrogen network integration case study, comprehensively considering both PSA costs and hydrogen utility costs. The results demonstrate that the method is computationally efficient and effectively reduces the refinery’s total annual costs. The accuracy of the optimization results is significantly improved compared to traditional methods, providing an effective solution for the collaborative optimization of the refinery hydrogen network and PSA.

Hierarchical Membrane Computing Algorithms for Optimizing Customer-to-Green-Manufacturer Decision-Making in Industrial Internet Platforms

This paper proposes a dynamic membrane algorithm (DMA)-oriented computing framework designed to optimize decision-making in Customer-to-Green-Manufacturer (C2GM) operations on industrial internet platforms. Unlike traditional methods that focus solely on economic metrics, the DMA integrates membrane computing principles with evolutionary optimization techniques and incorporates green manufacturing objectives (e.g., energy efficiency, waste reduction, carbon footprint). By doing so, it dynamically aligns customer demands with manufacturing capabilities in real time, ensuring both operational efficiency and environmental stewardship. The DMA facilitates parallel and hierarchical processing of complex decision tasks, mapping evolutionary rules and manufacturing operations into a structured membrane system that accelerates convergence and improves scalability. Experimental evaluations—both in controlled simulations and a real-world case study of C2GM operations in Yiwu—demonstrate that the DMA not only achieves faster and more stable convergence than genetic algorithms but also supports greener production processes. This integrated approach thus enhances strategic decision-making, offering a sustainable pathway for advancing industrial internet ecosystems and global supply chains.

Chinese Business Ethics: Global Perspectives and Local Reconfiguration

This review examines the book "Chinese Business Ethics: Global Perspectives and Local Reconfiguration" (in Chinese 中国商业伦理学：全球视野与本土重构), edited by Lü Li, Huang Haixiao, et al., which offers a pioneering exploration of business ethics through the lens of Chinese philosophical traditions and global frameworks. The book addresses the dominance of Western theories in Chinese business ethics education and proposes a localized perspective by integrating Confucian, Daoist, and other indigenous ethical principles. Through seven thematic chapters, the authors analyze topics such as marketing, human resource management, accounting, sustainability, and entrepreneurship, providing theoretical insights and practical applications. Enriched with vivid case studies, this work bridges the gap between historical traditions and contemporary business challenges, offering a model of ethical decision-making that is both culturally rooted and globally resonant. This review highlights the contributions of the book to the field of business ethics and its potential to inspire future scholarship and practice.

Impact of climate change on land use and relationship with land surface temperature: representative case study in Iraq

Impact of climate change on land use and relationship with land surface temperature: representative case study in Iraq

Case Study of US 75: Assessment of Full Depth Repair Effectiveness

Full depth repair (FDR) is a widely used repair method for repairing distresses in concrete pavement. FDR typically includes restoring load transfer to the adjacent, unrepaired slab and once it is placed is expected to perform similarly to the original pavement. However, current standard methods of FDR have only limited effect and often yield insufficient long term performance since they fail to address the deterioration ongoing in the adjacent slabs. It seems that standard plans uniformly recommend replacing weakened base or subgrade material with better material however, they only treat the area under the patched section, while the condition of adjacent sections continue to suffer because of the effects of infiltrated water and weakened base and subgrade. Moreover, details rarely call for resealing of the joint after placement of the repair which is a basic preventative strategy to reduce distresses in the adjacent concrete pavement as well as the patch. A major test of FDR for jointed concrete pavement on US 75 in Sherman, Texas is studied to evaluate FDR effectiveness and recommend possible improvements. Sample sections were classified by visual inspection into good and poor areas containing old and newly placed patches. Each section was tested to ascertain the repaired patched and existing adjacent pavement conditions using non destructive test (NDT).

The Influence of Small-Scale Businesses in Employment Generation and Economic Growth in Nigeria: A Case Study of Selected Business in Suburban Lagos

This research examines the roles of small-scale business (SSBs) in employment generation and financial growth, with a focus on businesses within the Ikorodu Local Government Area. The study employs a systematic methodology to address the research objectives, including hypotheses testing, population and sample selection, data collection, and analysis. A sample of fifty (50) respondents, drawn using simple random and stratified sampling techniques, provides a fair representation of the study population. Primary data were collected through questionnaires, ensuring cost-effective, time-efficient, and accurate data acquisition. The collected data were analyzed using frequency distribution tables and the chi-square test to assess whether observed proportions align with expected values. The findings reveal insights into the demographic and business characteristics of the sample, including gender distribution, age range, business duration, and educational qualifications of the respondents. The chi-square analysis tested two hypotheses: the significant role of SSBs in employment generation and financial growth. Results indicate that small-scale business significantly contribute to employment generation and the financial growth of the economy. This research offers valuable insights into the potential of small-scale businesses as drivers of economic development, with implications for policy and practice in promoting sustainable entrepreneurship.

Which is the more effective management strategy for irritability and challenging behaviour in autism, medication or psychosocial interventions?

Purpose The purpose of this study is to critically analyse the current research around the impact of management strategies on challenging behaviour in autism. Design/methodology/approach Mixed method analysis. Findings Seven studies were included for discussion. The author found significant heterogeneity in the outcome measures of all the studies and was unable to provide a meta-analysis. The results showed that psychosocial interventions offer the most promise in terms of safety and efficacy. The author was unable to explain what part of their intervention had the most significant effect. Antipsychotic interventions demonstrated the most robust methodologies and therefore, the results are more reliable. Research limitations/implications These studies provide valuable evidence for UK guidelines and suggest that lower doses of medication do not have a therapeutic effect on patients. Furthermore, these studies do not use psychosocial interventions alongside medication reduction, which may have proven valuable to help the author’s understanding of the different management strategies for treating challenging behaviour in autism. Thus, this literature review recommends further studies in the reduction of medication alongside psychosocial interventions with a larger number of participants recruited from a diverse range of backgrounds. Practical implications Gerrard et al. (2019) hope that positive behavioural support will become standard practice for specialist teams following the results of their findings and conclude that in the absence of effective management strategies, there is a greater likelihood of the re-introduction of medication. Admittedly, they do not understand what components of their intervention had the greatest significance on the results and identify this as a limitation of the study. In the single case study by Lee, Rhodes and Gerrard (2019), they claim that medication reduction and discontinuation can be successful if the rate of titration reduction is slowed down. This may offer some insight into the success of the strategy by Gerrard et al. (2019). Social implications Bishop-Fitzpatrick et al. (2013) state that the researchers in their systematic reviews used “creative techniques” to address the core deficits of autism (p. 7). It can be argued that psychosocial interventions are highly individualized, making them difficult to implement in practice and are ungeneralizable. For this purpose, the reduction of medication cannot be implemented consistently as it is not clear what strategies are effective. Originality/value This is the author’s own work, and to the best of the author’s knowledge, it does not infringe upon anyone’s copyright and that any ideas, techniques or any other material are fully acknowledged in accordance with the Harvard referencing guidelines.

Study on the Application of Service-Learning Theory to Social Practice in Chinese Universities

This study discusses the application of service-learning theory in social practice in Chinese universities. By analyzing two typical case studies from Nankai University and Sichuan University, it reveals the ways of applying service-learning theory in Chinese university social practice, the implementation path and its positive effects on college students, universities and communities. The results show that the application of service-learning theory in Chinese social practice not only significantly improves college students' academic understanding and sense of civic responsibility, but also demonstrates positive results in cultivating college students' practical skills, interpersonal skills, and teamwork spirit and so on. At the same time, the university and the community have achieved two-way reciprocity. This study further points out that the application of service-learning theory to social practice can make up for the current problems of single content, weak reflection, and unsatisfactory results of social practice programs in Chinese universities. Based on this, the study proposes specific recommendations to promote the integration of service-learning theory and social practice, including emphasizing the education of civic responsibility, increasing social support, and strengthening the effective application of reflection mechanisms, which provide a new theoretical basis and practical strategy for improving the quality of social practice education in Chinese universities.

Global analysis of the proposed benefits from REDD+ projects: influencing factors and discrepancies

Abstract Reducing emissions from deforestation and forest degradation in developing countries (REDD+) was initially envisioned to incentivize forest protection through payments for ecosystem services (PES). Nevertheless, our global understanding of REDD+ project benefits proposed by proponents to local communities is limited. To address this gap, we ask: Globally, how do REDD+ projects propose to provide local community benefits? 
We use and update the international database on REDD+ projects (ID-RECCO) to analyze the REDD+ benefits proposed by 347 REDD+ projects in 55 countries. Logistic regression and chi-square tests explore relationships between the probability of a benefit type being proposed and influencing factors. Our global-level analysis can serve as a useful benchmark for empirical case studies.
Our findings show the diversity of benefits REDD+ projects propose Most REDD+ projects (89%) proposed a mix of monetary and non-monetary benefits; employment was proposed in > ¾ of project, while forest restrictions were proposed by 52% of REDD+ projects. Many projects proposed infrastructure (107) or services (181). Factors that influence the probability a benefit type was proposed by a project include carbon certification standards, de facto forest user types, and country. 
PES-style conditional payments are no longer emblematic of benefits from REDD+ projects to local communities. Instead, REDD+ projects typically propose employment, livelihood activities, tenure clarification, and public goods and services. Further empirical research is needed to understand how meaningful these benefits are to local people, and their contribution in producing effective and equitable project outcomes. National policy and legal frameworks on benefit sharing, more explicit standards on benefit sharing among carbon standards, and better risk management related to community expectations from REDD+ projects are important avenues to ensure REDD+ benefits are aligned with the needs and realities of local communities.

Elaborate numerical analysis and new fibre Bragg grating monitoring methods for the ground pressure in shallow large-diameter shield tunnels: a case study of the yellow crane tower tunnel project

Elaborate numerical analysis and new fibre Bragg grating monitoring methods for the ground pressure in shallow large-diameter shield tunnels: a case study of the yellow crane tower tunnel project

A parallel bioreactor strategy to rapidly determine growth-coupling relationships for bioproduction: a mevalonate case study

BackgroundThe climate crisis and depleting fossil fuel reserves have led to a drive for ‘green’ alternatives to the way we manufacture chemicals, and the formation of a bioeconomy that reduces our reliance on petrochemical-based feedstocks. Advances in Synthetic biology have provided the opportunity to engineer micro-organisms to produce compounds from renewable feedstocks, which could play a role in replacing traditional, petrochemical based, manufacturing routes. However, there are few examples of bio-manufactured products achieving commercialisation. This may be partially due to a disparity between academic and industrial focus, and a greater emphasis needs to be placed on economic feasibility at an earlier stage. Terpenoids are a class of compounds with diverse use across fuel, materials and pharmaceutical industries and can be manufactured biologically from the key intermediate mevalonate.ResultsHere, we report on a method of utilising parallel bioreactors to rapidly map the growth-coupling relationship between the specific product formation rate, specific substrate utilisation rate and specific growth rate. Using mevalonate as an example product, a maximum product yield coefficient of 0.18 gp/gs was achieved at a growth rate (μ) of 0.34 h−1. However, this process also led to the formation of the toxic byproduct acetate, which can slow growth and cause problems during downstream processing. By using gene editing to knock out the ackA-pta operon and poxB from E. coli BW25113, we were able to achieve the same optimum production rate, without the formation of acetate.ConclusionsWe demonstrated the power of using parallel bioreactors to assess productivity and the growth-coupling relationship between growth rate and product yield coefficient of mevalonate production. Using genetic engineering, our resultant strain demonstrated rapid mevalonate formation without the unwanted byproduct acetate. Mevalonate production is quantified and reported in industrially relevant units, including key parameters like conversion efficiency that are often omitted in early-stage publications reporting only titre in g/L.

Model-based definition-assisted asset administration shell as enabler for smart production line

ABSTRACT The smart production line needs to adapt continuously to satisfy the growing demand for customized products. However, the inability of equipment to interoperate effectively hampers the quick reconfiguration of smart production lines. The Reference Architecture Model for Industry 4.0 (RAMI4.0) introduces the Asset Administration Shell (AAS) as a novel method to enhance interoperability in Industry 4.0 (I4.0). AAS creates a digital representation of assets. To further enhance the efficiency of AAS configuration, this paper presents the Model-Based Definition (MBD)-assisted AAS (MBD-AAS) specifically for designing smart production lines. MBD-AAS streamlines AAS configuration and facilitates plug-and-play (PnP) capabilities for equipment in smart production lines. This study validates the practicality and advantages of MBD-AAS through a case study focused on an unmanned aerial vehicle (UAV) production line design. The experimental findings indicate that MBD-AAS enhances the interoperability of AAS and decreases the design time for UAV production lines.

Standardization for Data Generation and Collection in the Dairy Industry: Addressing Challenges and Charting a Path Forward

Standards for data generation and collection are important for integration and for achieving data-driven actionable insights in dairy farming. Data integration and analysis are critical for advancing the dairy industry, enabling better decision-making, and improving operational efficiencies. This commentary paper discusses the challenges of and proposes pathways for standardizing data generation and collection based on insights from a multidisciplinary group of stakeholders. Drawing from a series of meetings of industry experts, academics, and farmers organized under the Dairy Brain Project’s Coordinated Innovation Network (CIN), we explore the benefits of creating uniform data generation and collection protocols to ensure compatibility and reliability across different data sources. Key insights include the importance of defining standardization at both farm and industry levels, the role of education and incentives, and the potential for using existing frameworks such as the International Committee for Animal Recording. Additionally, we highlight industry-specific case studies, including successful examples from Brazil such as GERAR, which focuses on reproductive performance data, and Labor Rural, which integrates data from multiple farms to provide valuable insights to farmers and milk processors. The paper concludes with recommendations for implementing these protocols and highlights the need to foster collaboration among stakeholders for the successful implementation and adoption of standardized data generation and collection protocols in the dairy industry.