Frontline Science: Rapid adipose tissue expansion triggers unique proliferation and lipid accumulation profiles in adipose tissue macrophages

Obesityâ related changes in adipose tissue leukocytes, in particular adipose tissue macrophages (ATMs) and dendritic cells (ATDCs), are implicated in metabolic inflammation, insulin resistance, and altered regulation of adipocyte function. We evaluated stromal cell and white adipose tissue (WAT) expansion dynamics with high fat diet (HFD) feeding for 3â 56 days, quantifying ATMs, ATDCs, endothelial cells (ECs), and preadipocytes (PAs) in visceral epididymal WAT and subcutaneous inguinal WAT. To better understand mechanisms of the early response to obesity, we evaluated ATM proliferation and lipid accumulation. ATMs, ATDCs, and ECs increased with rapid WAT expansion, with ATMs derived primarily from a CCR2â independent resident population. WAT expansion stimulated proliferation in resident ATMs and ECs, but not CD11c+ ATMs or ATDCs. ATM proliferation was unperturbed in Csf2â and Rag1â deficient mice with WAT expansion. Additionally, ATM apoptosis decreased with WAT expansion, and proliferation and apoptosis reverted to baseline with weight loss. Adipocytes reached maximal hypertrophy at 28 days of HFD, coinciding with a plateau in resident ATM accumulation and the appearance of lipidâ laden CD11c+ ATMs in visceral epididymal WAT. ATM increases were proportional to tissue expansion and adipocyte hypertrophy, supporting adipocyteâ mediated regulation of resident ATMs. The appearance of lipidâ laden CD11c+ ATMs at peak adipocyte size supports a role in responding to ectopic lipid accumulation within adipose tissue. In contrast, ATDCs increase independently of proliferation and may be derived from circulating precursors. These changes precede and establish the setting in which largeâ scale adipose tissue infiltration of CD11c+ ATMs, inflammation, and adipose tissue dysfunction contributes to insulin resistance.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142947/1/jlb10097_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142947/2/jlb10097.pd

Exergy analysis of incremental sheet forming

Research in the last 15 years has led to die-less incremental forming processes that are close to realization in an industrial setup. Whereas many studies have been carried out with the intention of investigating technical abilities and economic consequences, the ecological impact of incremental sheet forming (ISF) has not been studied so far. Using the concept of exergy analysis, two ISF technologies, namely single sided and double sided incremental forming, are investigated and compared to conventional forming and hydroforming. A second exergy analysis is carried out with the purpose of examining the environmental impact of different forming technologies from a supply chain perspective. Therefore, related upstream activities (die set production, aluminum sheet production and energy conversion and supply) are included into the exergy analysis. The entire supply chain is modeled with Matlab/Simulink. The results of both analyses suggest that ISF is environmentally advantageous for prototyping and small production runs.United States. Dept. of Energy (Award DE-EE0003460

Beyond constructs and linkages : a grounded model of the manufacturing strategy formation process

The existing models of manufacturing strategy (MS) process are presented in such aggregated forms that they render little support towards advancing the process understanding beyond identifying categories, concepts, broad constructs, and their macro level linkages. This paper presents an alternative process model of MS developed based on the “grounded theory” approach. The study captured the consistent patterns of organizational decision-making in order to reconstruct the MS process as a “developmental event sequence”. The goal was to determine how strategic manufacturing decisions are made and why they are made in such a manner. “Within-case” patterns of strategy formation in all five cases suggested that the MS process takes rather a non-linear path, but progresses across four distinct phases, namely initiation-consolidation-commitment-realization. Further, within each phase, multiple modes of progression were discerned. The three modes of strategy initiation: forced, opportunistic, evolutionary, and the likely routes they follow are largely determined by the stimuli of initiation and the influence of contextual factors. The distinctions between the formal top-down planning approach and the alternative approaches to strategy formation as well as the effects of contextual factors on the MS process can be plausibly explained using this model. Further, it was found to be useful in better understanding a number of MS process related phenomena that had not been adequately explained in previous research. From the practitioners’ point of view, the process model developed through the study will help organizations to identify and better manage the alternative forms of strategy formation, including deploying appropriate communication and strategy dissemination mechanisms, performance measures etc. On the scholarly front, deeper understanding of the MS process gained through this study will certainly help advance theory building in the area with the added significance that this study has successfully shifted the level of analysis across analytical boundaries