27 research outputs found

    Enabling Complex Fibre Geometries Using 3D Printed Axon-Mimetic Phantoms

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    Purpose: To introduce a method to create 3D-printed axon-mimetic phantoms with complex fibre orientations to characterise the performance of diffusion magnetic resonance imaging (MRI) models and representations in the presence of orientation dispersion. Methods: An extension to an open-source 3D printing package was created to produce a set of five 3D-printed axon-mimetic (3AM) phantoms with various combinations of bending and crossing fibre orientations. A two-shell diffusion MRI scan of the five phantoms in water was performed at 9.4T. Diffusion tensor imaging (DTI), diffusion kurtosis imaging (DKI), the ball and stick model, neurite orientation density and dispersion imaging (NODDI), and Bingham-NODDI were all fit to the resulting diffusion MRI data. A ground truth map of that phantom’s crossing angles and/or arc radius was registered to the diffusion-weighted images. Metrics from each model and representation were compared to the ground-truth maps, and a quadratic regression model was fit to each combination of output metric and ground-truth metric. Results: The mean diffusivity (MD) metric defined by DTI was insensitive to crossing angle but increased with fibre curvature. Axial diffusivity (AD) decreased with increasing crossing angle. DKI’s diffusivity metrics replicated the trends seen in DTI, and its mean kurtosis (MK) metric decreased with fibre curvature, except in regions with high crossing angles. The estimated stick volume fraction in the ball and stick model decreased with increasing fibre curvature and crossing angle. NODDI’s intra-neurite volume fraction was insensitive to crossing angle, and its orientation dispersion index (ODI) was correlated to crossing angle. Bingham-NODDI’s intra-neurite volume fraction was also insensitive to crossing angle, while its primary ODI (ODIP) was also correlated to crossing angle and its secondary ODI (ODIS) was insensitive to crossing angle. For both NODDI models, the volume fractions of the extra-neurite and CSF compartments had low reliability with no clear relationship to crossing angle. Conclusion: Inexpensive 3D-printed axon-mimetic phantoms can be used to investigate the effect of fibre curvature and crossings on diffusion MRI representations and models of diffusion signal. The dependence of several representations and models on fibre dispersion/crossing was investigated. As expected, Bingham-NODDI was best able to characterise planar fibre dispersion in the phantoms

    Assessing the Moderating Effect of Innovation on the Relationship between Information Technology and Supply Chain Management: An Empirical Examination

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    This study examines how innovation (INN) influences the relationship between supply chain management and information technology in Jordan. 211 employees of Jordanian industrial enterprises who work in the Operations Department provided information for the study, which examines this subject. The findings indicate a close connection between information technology and supply chain management. Innovation also dramatically modifies the interaction between supply chain management and information technology. Management help may be the subject of future research

    A statistical analysis of life cycle assessment for buildings and buildings’ refurbishment research

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    This study aims to examine the literature related to environmental Life Cycle Assessment (LCA) for buildings and buildings' refurbishment from 1994 to 2022 by implementing a statistical analysis based on 'Web of Science' databases. LCA is viewed as a consolidated process that measures the environmental performance of buildings and their services, aiming to address the potential environmental impacts over the life cycle of buildings. A total of 1336 retrieved journal publications for LCA for buildings and 169 journal publications for LCA in building refurbishment. The articles' patterns were investigated in terms of subject categories, journals, countries, and the most highly cited articles. The findings reveal that LCA publications for buildings and building refurbishment have increased over the period 1994–2022, with China being the leading country contributing to the largest number of articles and possessing the most significant influence, followed by the USA for LCA in buildings. While Portugal is the leading country, followed by Italy, for LCA Buildings' Refurbishments. 97.08% of the publications were written in English, 2.04% in German, and 0.68% in Spanish. French and Japanese were the remaining languages, each with one publication, accounting for 0.2% of the 1336 building LCA publications. In contrast to refurbishment, LCA publications were written in only two languages, English (98.7%) and German (1.3%). Results show that the subject area differs depending on the type of LCA publication, with building LCA focusing on construction engineering while refurbishment focused on environmental topics. According to the IF, the most influential journal was renewable & sustainable energy for buildings and refurbishment LCA. However, journal distribution within LCA is still limited, and assessment methods and theme analysis still need to catch up with a clear gap in LCA in environmental impact mitigation and analysis methodologies, which will be a prominent direction of future building LCA research

    Variations in the financial impact of the COVID-19 pandemic across 5 continents: A cross-sectional, individual level analysis.

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    BACKGROUND: COVID-19 has caused profound socio-economic changes worldwide. However, internationally comparative data regarding the financial impact on individuals is sparse. Therefore, we conducted a survey of the financial impact of the pandemic on individuals, using an international cohort that has been well-characterized prior to the pandemic. METHODS: Between August 2020 and September 2021, we surveyed 24,506 community-dwelling participants from the Prospective Urban-Rural Epidemiology (PURE) study across high (HIC), upper middle (UMIC)-and lower middle (LMIC)-income countries. We collected information regarding the impact of the pandemic on their self-reported personal finances and sources of income. FINDINGS: Overall, 32.4% of participants had suffered an adverse financial impact, defined as job loss, inability to meet financial obligations or essential needs, or using savings to meet financial obligations. 8.4% of participants had lost a job (temporarily or permanently); 14.6% of participants were unable to meet financial obligations or essential needs at the time of the survey and 16.3% were using their savings to meet financial obligations. Participants with a post-secondary education were least likely to be adversely impacted (19.6%), compared with 33.4% of those with secondary education and 33.5% of those with pre-secondary education. Similarly, those in the highest wealth tertile were least likely to be financially impacted (26.7%), compared with 32.5% in the middle tertile and 30.4% in the bottom tertile participants. Compared with HICs, financial impact was greater in UMIC [odds ratio of 2.09 (1.88-2.33)] and greatest in LMIC [odds ratio of 16.88 (14.69-19.39)]. HIC participants with the lowest educational attainment suffered less financial impact (15.1% of participants affected) than those with the highest education in UMIC (22.0% of participants affected). Similarly, participants with the lowest education in UMIC experienced less financial impact (28.3%) than those with the highest education in LMIC (45.9%). A similar gradient was seen across country income categories when compared by pre-pandemic wealth status. INTERPRETATION: The financial impact of the pandemic differs more between HIC, UMIC, and LMIC than between socio-economic categories within a country income level. The most disadvantaged socio-economic subgroups in HIC had a lower financial impact from the pandemic than the most advantaged subgroup in UMIC, with a similar disparity seen between UMIC and LMIC. Continued high levels of infection will exacerbate financial inequity between countries and hinder progress towards the sustainable development goals, emphasising the importance of effective measures to control COVID-19 and, especially, ensuring high vaccine coverage in all countries. FUNDING: Funding for this study was provided by the Canadian Institutes of Health Research and the International Development Research Centre

    Household, community, sub-national and country-level predictors of primary cooking fuel switching in nine countries from the PURE study

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    Introduction. Switchingfrom polluting (e.g. wood, crop waste, coal)to clean (e.g. gas, electricity) cooking fuels can reduce household air pollution exposures and climate-forcing emissions.While studies have evaluated specific interventions and assessed fuel-switching in repeated cross-sectional surveys, the role of different multilevel factors in household fuel switching, outside of interventions and across diverse community settings, is not well understood. Methods.We examined longitudinal survey data from 24 172 households in 177 rural communities across nine countries within the Prospective Urban and Rural Epidemiology study.We assessed household-level primary cooking fuel switching during a median of 10 years offollow up (∼2005–2015).We used hierarchical logistic regression models to examine the relative importance of household, community, sub-national and national-level factors contributing to primary fuel switching. Results. One-half of study households(12 369)reported changing their primary cookingfuels between baseline andfollow up surveys. Of these, 61% (7582) switchedfrom polluting (wood, dung, agricultural waste, charcoal, coal, kerosene)to clean (gas, electricity)fuels, 26% (3109)switched between different polluting fuels, 10% (1164)switched from clean to polluting fuels and 3% (522)switched between different clean fuels

    Household, community, sub-national and country-level predictors of primary cooking fuel switching in nine countries from the PURE study

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    Evaluating Mobile E-Learning Systems Acceptance: An Integrated Model

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    Previous studies have confirmed that managers need to develop influencing strategies to encourage employees to accept mobile information systems. Despite the recognition in past research that external variables can influence employee’s perceptions, the explanation of how their approval of the framework is affected by these external variables’ pathways or procedures remains limited. Participants were selected from Malaysian institutions that have previously rolled out mobile e-learning technologies into their operations. Empirical findings disclose that source credibility is positively associated with playfulness, perceived ease of use, and perceived usefulness. Similarly, organizational support and task equivocality are significantly related to perceived ease of use and perceived usefulness. Additionally, perceived ease of use positively affects playfulness, perceived usefulness, and employee attitude. Finally, an employee’s attitude is positively and significantly related to behavioral intentions (BI). The findings of this study provide insight for firms considering implementing a mobile information system at all levels of their institutions. Furthermore, it offers employees valuable information about the system, its value, benefits, and advantages
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