ABSTRACT
Mitochondria surrounding lipid droplets (Peri-Droplet Mitochondria;PDM) maintain a unique proteome which is not equilibrated with the rest of the mitochondrial population. We find that PDM remain stationary and elongated on lipid droplets, fuel lipid droplet expansion, and do not fuse with cytosolic mitochondria. Compared to cytosolic mitochondria, PDM have higher capacity to metabolize pyruvate but reduced capacity to oxidize fatty acids. We reveal for the first time the mechanism by which the elongated mitochondrial shape of PDM differentiate their fuel preference from that of cytosolic mitochondria. We find that mitochondrial elongation reduces fatty acid utilization by inhibiting CPT1 activity. On the other hand, we find that mitochondrial fragmentation, such as observed in NASH, increases mitochondrial lipid utilization and may act as a compensatory mechanism to reduce lipotoxicity. Indeed, inhibition of fission in a model of NASH exacerbated NASH phenotype. We developed a cell-based imaging for the quantification of mitochondria-lipid droplet association and identified a set of small molecules that detach mitochondria from lipid droplets (PDM-Detachers). New unpublished data demonstrate PDM detachers induce lipolysis and lipid droplet shrinkage. Using these tools we assessed the role of lipid droplets in SARS-CoV2 expansion. We find that proliferation of various coronaviruses can be strongly inhibited by PDM-detachers and enhanced by attaching mitochondria to lipid droplets. We demonstrate that PDM can be found in humans. We studied adipose tissue from pheochromocytoma patients, a model of white adipose browning characterized by enhanced capacity for energy expenditure. Remarkably, bioenergetic changes associated with browning were primarily localized to PDM. Similar changes were found in a mouse model of re-browning, where PDM increased in whitened brown adipose tissue upon reducing housing temperature. Copyright © 2022
ABSTRACT
Purpose - This study carried out an empirical study of the impact of sustainability - which has been gaining attention as challenges are arising in supply chains based on existing trade networks due to the impact of the COVID-19 pandemic - on SCM performance and financial performance of Korean SMEs. The study seeks to propose a measurement model to enhance the SCM performance and financial performance of Korean SMEs and to identify the relationship between sustainability, SCM performance and financial performance to suggest implications to SMEs, governments, and relevant organizations. Design/methodology - Our Analysis established hypotheses that economic sustainability, environmental sustainability, and other factors related to sustainability have a positive impact on SCM performance and financial performance as well as SCM performance has a positive impact on financial performance, making empirical validations by utilizing Structural Equation Modeling based on data collected through survey from Korean SMEs. Findings - According to an empirical study, although environmental sustainability and economic sustainability among factors of sustainability had a positive influence on SCM performance, social sustainability did not have a statistically significant influence. Furthermore, it was learned that only economic sustainability had a positive influence on financial performance while SCM performance has a positive influence on financial performance. Originality/value - This empirical study explored the relationship between SCM performance and financial performance of Korean SMEs with a high tendency to depend on specific supply chains when the international trade network is in confusion and/or the global supply chain has collapsed. If Korean SMEs allocate management resources to the factors deducted from this study, they would be able to build more efficient supply chains and improve financial performance to improve sustainability.
ABSTRACT
Purpose - This study aims to analyze the characteristics of network construction by Norwegian Air and AirAsia X, which are recognized as leading airlines in the long-haul LCC market. Based on this analysis, this study intends to provide implications for networking strategies for Korean LCCs that seek to enter the long-haul market when the aviation market stabilizes again upon the end of the COVID-19 pandemic. Design/methodology - To conduct the network analysis on long-haul low-cost airlines, the Official Airline Guide (OAG) Schedule Analyzer was used to extract long-haul data of Norwegian Air and AirAsia X. To analyze the trend of the long-haul route network, we obtained the data from 3 separate years between 2011 and 2019. The network was analyzed using UCINET 6.0 in order to examine the network structure of long-haul low-cost airlines and the growth trend of each stage. Findings - Analyzing the network of long-haul routes by visualizing the network structure of low-cost carriers showed the following results. In its early years, Norwegian Air's long-haul route network, centering on regional airports in Spain and Sweden, connected European regions, the Middle East, and Africa. As time passed, however, the network expanded and became steadily strong as the airline connected airports in other European countries to North America and Asia. In addition, in 2011, AirAsia X showed links to parts of Europe, such as London and Paris, the Middle East and India, and Australia and Northeast Asia, centering on the Kuala Lumpur Airport. Although the routes in Europe were suspended, the network continued to expand while concentrating on routes of less than approximately 7,000 km. It was found that instead of giving up on ultra-long-haul routes such as Europe, the network was further expanded in Northeast Asia, such as the routes in Korea and Japan centering on China. Originality/value - Until the COVID-19 pandemic broke out, Norwegian Air actively expanded long-haul routes, resulting in the number of long-haul routes quintupling since 2011. The unfortunate circumstance, wherein the world aviation market was rendered stagnant due to the outbreak of COVID-19, hit Norwegian Air harder than any other low-cost carriers. However, in the case of AirAsia X, it was found that it did not suffer as much damage as Norwegian Air because it initially withdrew from unprofitable routes over 7,000 km and grew by gradually increasing profitable destinations over shorter distances. When the COVID-19 pandemic ends and the aviation market stabilizes, low-cost carriers around the world, including Korea, that enter the long-haul route market will need to employ strategies to analyze the marketability of potential routes and to launch the routes that yield the highest profits without being bound by distance. For stable growth, it is necessary to take a conservative stance;first, by reviewing the business feasibility of the operating a small number of highly profitable routes, and second, by gradually expanding these routes.