Primary and secondary market strategies for regulatory compliance and profit

Incorporating sustainability into operational strategies has gained tremendous momentum among firms. An important driver is the need to comply with environmental legislation that grows in both coverage and stringency. Moreover, many firms also come to recognize the value of establishing sustainable operations to enhance profitability, especially with its potential to be scaled up by the rapidly increasing volume of production and end-of-life products. In this dissertation, I study firms' sustainable operational strategies either for complying with legislation or for improving profitability. In the first essay (Chapter II), I point out that, although largely overlooked by the literature, increasing product durability can be utilized, in addition to recyclability, as a design lever when a durable product producer is imposed with the responsibility of end-of-life product management. The analysis reveals that when trade-off between the two design options exists, legislation can lead to surprising design outcomes. The second essay (Chapter III) studies the strategies of Testing and Remanufacturing as instruments for a durable product manufacturer to tackle the lemons problem. The lemons problem arises in secondary markets as the sellers, being the original owners of the used products, take advantage of the superior quality information to strategically sell the low-quality items to the secondary markets while keeping the high-quality ones. This study reveals the unexplored functionalities of conducting testing and remanufacturing in resolving the lemons problem, which take effects through enabling the manufacturer a stronger control over the secondary markets. The third essay (Chapter IV) builds upon these insights and proposes a framework to empirically study the effectiveness of the Testing and Remanufacturing strategies in dealing with the lemons problem in the used automobile markets.Ph.D

Predicting 1-, 3-, 5-, and 8-year all-cause mortality in a community-dwelling older adult cohort: relevance for predictive, preventive, and personalized medicine

Background: Population aging is a global public health issue involving increased prevalence of age-related diseases, and concomitant burden on medical resources and the economy. Ninety-two diseases have been identified as age-related, accounting for 51.3% of the global adult disease burden. The economic cost per capita for older people over 60 years is 10 times that of the younger population. From the aspects of predictive, preventive, and personalized medicine (PPPM), developing a risk-prediction model can help identify individuals at high risk for all-cause mortality and provide an opportunity for targeted prevention through personalized intervention at an early stage. However, there is still a lack of predictive models to help community-dwelling older adults do well in healthcare. Objectives: This study aims to develop an accurate 1-, 3-, 5-, and 8-year all-cause mortality risk-prediction model by using clinical multidimensional variables, and investigate risk factors for 1-, 3-, 5-, and 8-year all-cause mortality in community-dwelling older adults to guide primary prevention. Methods: This is a two-center cohort study. Inclusion criteria: (1) community-dwelling adult, (2) resided in the districts of Chaonan or Haojiang for more than 6 months in the past 12 months, and (3) completed a health examination. Exclusion criteria: (1) age less than 60 years, (2) more than 30 incomplete variables, (3) no signed informed consent. The primary outcome of the study was all-cause mortality obtained from face-to-face interviews, telephone interviews, and the medical death database from 2012 to 2021. Finally, we enrolled 5085 community-dwelling adults, 60 years and older, who underwent routine health screening in the Chaonan and Haojiang districts, southern China, from 2012 to 2021. Of them, 3091 participants from Chaonan were recruited as the primary training and internal validation study cohort, while 1994 participants from Haojiang were recruited as the external validation cohort. A total of 95 clinical multidimensional variables, including demographics, lifestyle behaviors, symptoms, medical history, family history, physical examination, laboratory tests, and electrocardiogram (ECG) data were collected to identify candidate risk factors and characteristics. Risk factors were identified using least absolute shrinkage and selection operator (LASSO) models and multivariable Cox proportional hazards regression analysis. A nomogram predictive model for 1-, 3-, 5- and 8-year all-cause mortality was constructed. The accuracy and calibration of the nomogram prediction model were assessed using the concordance index (C-index), integrated Brier score (IBS), receiver operating characteristic (ROC), and calibration curves. The clinical validity of the model was assessed using decision curve analysis (DCA). Results: Nine independent risk factors for 1-, 3-, 5-, and 8-year all-cause mortality were identified, including increased age, male, alcohol status, higher daily liquor consumption, history of cancer, elevated fasting glucose, lower hemoglobin, higher heart rate, and the occurrence of heart block. The acquisition of risk factor criteria is low cost, easily obtained, convenient for clinical application, and provides new insights and targets for the development of personalized prevention and interventions for high-risk individuals. The areas under the curve (AUC) of the nomogram model were 0.767, 0.776, and 0.806, and the C-indexes were 0.765, 0.775, and 0.797, in the training, internal validation, and external validation sets, respectively. The IBS was less than 0.25, which indicates good calibration. Calibration and decision curves showed that the predicted probabilities were in good agreement with the actual probabilities and had good clinical predictive value for PPPM. Conclusion: The personalized risk prediction model can identify individuals at high risk of all-cause mortality, help offer primary care to prevent all-cause mortality, and provide personalized medical treatment for these high-risk individuals from the PPPM perspective. Strict control of daily liquor consumption, lowering fasting glucose, raising hemoglobin, controlling heart rate, and treatment of heart block could be beneficial for improving survival in elderly populations

Buyang Huanwu Decoction Attenuates Infiltration of Natural Killer Cells and Protects Against Ischemic Brain Injury

Background/Aims: Natural killer (NK) cells are among the first immune cells that respond to an ischemic insult in human brains. The infiltrated NK cells damage blood-brain barrier (BBB) and exacerbate brain infarction. Buyang Huanwu Decoction (BHD), a classic Chinese traditional herbal prescription, has long been used for the treatment of ischemic stroke. The present study investigated whether BHD can prevent brain infiltration of NK cells, attenuate BBB disruption and improve ischemic outcomes. Methods: Transient focal cerebral ischemia was induced in rats by a 60-minute middle cerebral artery occlusion, and BHD was orally administrated at the onset of reperfusion, 12 hours later, then twice daily. Assessed parameters on Day 3 after ischemia were: neurological and motor functional deficits through neurological deficit score and rotarod test, respectively; brain infarction through TTC staining; BBB integrity through Evans blue extravasation; matrix metalloproteinase-2/9 activities through gelatin zymography; tight junction protein, nuclear factor-kB (NF-kB) p65 and phospho-p65 levels through Western blotting; NK cell brain infiltration and CXCR3 levels on NK cells through flow cytometry; interferon-γ production through ELISA; CXCL10 mRNA levels through real-time PCR; CXCL10 expression and p65 nuclear translocation through immunofluorescence staining. Results: BHD markedly reduced brain infarction, improved rotarod performance, and attenuated BBB breakdown. Concurrently, BHD attenuated the upregulation of matrix metalloproteinase-2/9 activities and the degradation of tight junction proteins in the ischemic brain. Infiltration of NK cells was observed in the ischemic hemisphere, and this infiltration was blunted by treatment with BHD. BHD suppressed brain ischemia-induced interferon-γ and chemokine CXCL10 production. Furthermore, BHD significantly reduced the expression of CXCR3 on brain-infiltrated NK cells. Strikingly, BHD did not affect NK cell levels or its CXCR3 expression in the spleen or peripheral blood after brain ischemia. The nuclear translocation of NF-kB p65 and phospho-p65 in the ischemic brain was inhibited by BHD. Conclusion: Our findings suggest that BHD prevents brain infiltration of NK cells, preserves BBB integrity and eventually improves ischemic outcomes. The inhibitory effects of BHD on NK cell brain invasion may involve its ability of suppressing NF-kB-associated CXCL10-CXCR3-mediated chemotaxis. Notably, BHD only suppresses NK cells and their CXCR3 expression in the ischemic brain, but not those in periphery

Mathematical models for coordination in supply chain management

published_or_final_versionMathematicsMasterMaster of Philosoph

Corrosion Behavior of Pressure Infiltration Diamond/Cu Composites in Neutral Salt Spray

Diamond particle-reinforced copper matrix composites (Diamond/Cu) are recognized as promising electronic packaging materials due to their excellent thermophysical properties. It is necessary to investigate the reliability of Diamond/Cu composites under extreme environmental conditions. The corrosion behavior of Diamond/Cu composites was studied in a 5 wt% NaCl neutral salt spray. Surface morphology, thermal conductivity, bending strength, corrosion rate, and corrosion depth resulting from corrosion were researched in this paper. The results showed that the corrosion phenomenon mainly occurs on the copper matrix, and the diamond and interface products do not corrode. The corrosion mechanism of Diamond/Cu composites was micro-galvanic corrosion. The corrosion product formed was Cu2Cl(OH)3. The salt spray environment had a great influence on the composite surface, but the composite properties were not significantly degenerated. After a 168-h test, the bending strength was unaltered and the thermal conductivity of gold-plated composites showed a slight decrease of 1–2%. Surface gold plating can effectively improve the surface state and thermal conductivity of Diamond/Cu composites in a salt spray environment

Carbon leakage: the impact of asymmetric regulation on carbon-emitting production

Regions with carbon emission regulations bear the risk of "carbon leakage'' if local producers shift production capacity to an unregulated region. We investigate the problem for a producer subject to geographically asymmetric emission regulation with uncertain future emission price. The producer has two ex-ante options to lower its compliance cost: investing in clean production technology in the regulated region and building production capacity in the unregulated region. The producer determines its production quantities ex-post, after emission price uncertainty is resolved. We study two anti-leakage policies, Border Tax (BT) and Output-Based Allocation (OB), where the former adopts a "stick'' approach that penalizes offshore production and the latter adopts a "carrot'' approach that grants free emission allowances for production in the regulated region. First, we show that the emission price uncertainty can exert opposing effects in the absence of an anti-leakage policy: When the expected emission price is low (high), a higher uncertainty aggravates (mitigates) carbon leakage. Second, through a comprehensive comparison, we highlight that while both BT and OB are able to reduce carbon leakage, BT has a stronger effect in both the regulated and unregulated regions in multiple dimensions, especially when the carbon leakage risk is high. Third, we find that a higher emission price uncertainty weakens the effect of both BT and OB. We therefore suggest that emission price uncertainty should be accounted for when formulating anti-leakage policies. Finally, we extend our analysis to a competitive case and find that the superiority of BT relative to OB is enhanced