Essays on Risk Mitigation Methods in Global Supply Chain Management

In this dissertation, we study risk mitigation methods in the area of global supply chain management. Recent economic uncertainties such as the U.S. credit and the Greek debt crises, and natural disasters such as the Japanese tsunami create a greater amount of uncertainty and risk for global supply chain operations. The goal of the dissertation is to develop new prescriptive policies for multinational corporations and global relief organizations in order to assist them in mitigating the risks present in their operating environment in an effective manner. The first essay of the dissertation investigates how a multinational corporation can effectively hedge against the exchange-rate risk by structuring and managing a supply chain in a global setting. Economic uncertainties such as the U.S. credit crises and the debt concerns in southern European countries (e.g., Greece, Italy, Portugal and Spain) call for new policies in order to operate under an increased level of uncertainty. For example, even though the Japanese Yen and the US Dollar are considered to be more stable currencies, they have exhibit significant fluctuations in recent times, putting the US Dollar at its record low against the Yen on October 24, 2011, since the Great Depression. Naturally, such exchange rate fluctuations increase the need to develop new risk mitigation policies that would assist global corporations in managing the fluctuations in their global revenues and profits. This essay provides multinational corporations with prescriptions for ways to cope with the increased amount of global economic uncertainty. It demonstrates that production hedging, defined as producing and supplying less than the firm\u27s total global demand, can be an effective policy in minimizing the negative implications of the exchange-rate risk while maximizing global profits. The second essay of the dissertation examines how a global relief organization can effectively hedge against the risk of demand uncertainty in its distribution of essential products to the areas of urgent needs. It is commonly observed that deficiencies in information infrastructure or economic instability contribute to the adversity of forecasting the need for essential supplies. This study stems from recognizing the ineffectiveness in the distribution of humanitarian aid supply in countries of need. Such distribution inefficiencies can lead to harmful consequences for many people. United Nations Children\u27s Fund (UNICEF) reports that in 2007 alone, 9.2 million children worldwide under the age of five died from largely preventable causes. It is important to recognize that many of the well-developed theories are hard to apply in these countries because of inferior infrastructure and the unstable nature of the economy and political environment. Thus, it is critical to develop new policies and insights for the managers of humanitarian organizations in order to increase the efficiency of distribution operations under uncertainty. Specifically, the second essay of this dissertation demonstrates that a relief organization can minimize the risk of shortages by strategically utilizing its limited budget on procurement and the transportation of essential supplies

Dual-Organ Transcriptomic Analysis of Rainbow Trout Infected With Ichthyophthirius multifiliis Through Co-Expression and Machine Learning

Ichthyophthirius multifiliis is a major pathogen that causes a high mortality rate in trout farms. However, systemic responses to the pathogen and its interactions with multiple organs during the course of infection have not been well described. In this study, dual-organ transcriptomic responses in the liver and head kidney and hemato-serological indexes were profiled under I. multifiliis infection and recovery to investigate systemic immuno-physiological characteristics. Several strategies for massive transcriptomic interpretation, such as differentially expressed genes (DEGs), Poisson linear discriminant (PLDA), and weighted gene co-expression network analysis (WGCNA) models were used to investigate the featured genes/pathways while minimizing the disadvantages of individual methods. During the course of infection, 6,097 and 2,931 DEGs were identified in the head kidney and liver, respectively. Markers of protein processing in the endoplasmic reticulum, oxidative phosphorylation, and the proteasome were highly expressed. Likewise, simultaneous ferroptosis and cellular reconstruction was observed, which is strongly linked to multiple organ dysfunction. In contrast, pathways relevant to cellular replication were up-regulated in only the head kidney, while endocytosis- and phagosome-related pathways were notably expressed in the liver. Moreover, interestingly, most immune-relevant pathways (e.g., leukocyte trans-endothelial migration, Fc gamma R-mediated phagocytosis) were highly activated in the liver, but the same pathways in the head kidney were down-regulated. These conflicting results from different organs suggest that interpretation of co-expression among organs is crucial for profiling of systemic responses during infection. The dual-organ transcriptomics approaches presented in this study will greatly contribute to our understanding of multi-organ interactions under I. multifiliis infection from a broader perspective.publishedVersio

LINE FUSION GENES: a database of LINE expression in human genes

BACKGROUND: Long Interspersed Nuclear Elements (LINEs) are the most abundant retrotransposons in humans. About 79% of human genes are estimated to contain at least one segment of LINE per transcription unit. Recent studies have shown that LINE elements can affect protein sequences, splicing patterns and expression of human genes. DESCRIPTION: We have developed a database, LINE FUSION GENES, for elucidating LINE expression throughout the human gene database. We searched the 28,171 genes listed in the NCBI database for LINE elements and analyzed their structures and expression patterns. The results show that the mRNA sequences of 1,329 genes were affected by LINE expression. The LINE expression types were classified on the basis of LINEs in the 5' UTR, exon or 3' UTR sequences of the mRNAs. Our database provides further information, such as the tissue distribution and chromosomal location of the genes, and the domain structure that is changed by LINE integration. We have linked all the accession numbers to the NCBI data bank to provide mRNA sequences for subsequent users. CONCLUSION: We believe that our work will interest genome scientists and might help them to gain insight into the implications of LINE expression for human evolution and disease. AVAILABILITY

The Feasibility of Endoscopy-Assisted Breast Conservation Surgery for Patients with Early Breast Cancer

PURPOSE: Breast conservation surgery (BCS) has become a standard treatment method for patients with early breast cancer. Endoscopy-assisted BCS (EABCS) can be performed through an inconspicuous periareolar and a small axillary incision for sentinel node biopsy, which may give better cosmetic outcomes than conventional BCS skin incisions. This study was designed to evaluate the feasibility of EABCS for patients with early breast cancer. METHODS: Forty-three patients were candidates for EABCS, and EABCS was performed in 40 patients with breast cancer between January 2008 and July 2010. Their clinicopathological features were retrospectively analyzed. Operative time, margin status, complications, and relapse-free survival were compared with those of patients treated by conventional BCS and who were treated at the same institute during the same period. RESULTS: The most common lesion site of the EABCS and conventional BCS groups was the upper area of the breast. Tumor size in all patients was less than 4 cm (range, 0.4-3.7 cm), and nodal involvement was found in eight (20%) patients in the BCS group. The mean operative time was 110 minutes for the EABCS group and 107 minutes for the conventional BCS group, and those were not significantly different. No significant difference in frozen or final margin status was observed between the EABCS and conventional BCS groups. Relapse-free survival was statistically equivalent between the groups with a median follow-up of 12 months. Postoperative complications occurred in five cases in four patients with EABCS, which was not significantly different from conventional BCS. CONCLUSION: Performing EABCS in patients with early breast cancer seems to be feasible and safe. Further study with a longer-term follow-up may be needed to confirm the clinical value of EABCS.ope

Histologic confirmation of huge pancreatic lipoma: a case report and review of literatures

Pancreatic lipomas are commonly diagnosed based on radiologic images, although the prevalence of lipomas has not been established. Histologic confirmation of pancreatic lipomas is extremely rare because surgical treatment is unnecessary in most cases. Endoscopic ultrasound-guided fine-needle aspiration cytology has been suggested to avoid unnecessary surgery to distinguish between a lipoma and a well-differentiated liposarcoma; however, surgery would be needed when the tumor is associated with symptoms or difficult to distinguish from a liposarcoma. We present a case of a pancreatic lipoma in a 54-year-old male patient that was histologically-confirmed by subtotal pancreatectomy

Effect of light-curing units on the thermal expansion of resin nanocomposites

Purpose—To examine the thermal expansion of resin nanocomposites after light-curing using different light-curing units. Methods—Four different resin nanocomposites and four different light-curing units [quartztungsten- halogen (QTH), light emitting diode (LED), laser, and plasma arc] were chosen. Metal dies were filled with resin to make specimens and light-cured. The light intensity and light-curing time of the QTH and LED light-curing units were 1000 mW/cm2 and 40 seconds, 700 mW/cm2 and 40 seconds for the laser, and 1600 mW/cm2 and 3 seconds for the plasma arc. The coefficient of thermal expansion (CTE) was evaluated using a thermomechanical analyzer (TMA) at temperatures ranging from 30–80°C. Results—The CTE of the resin nanocomposites tested ranged from 28.5 to 65.8 (×10−6/°C), depending on the product and type of light-curing unit used. Among the specimens Grandio showed the lowest CTE. The specimens cured using the plasma arc unit (Apollo 95E) showed the highest CTE. There was a linear correlation between the CTE and filler content (vol%) (R: −0.94~ −0.99 depending on the light-curing unit). The results may suggest a careful selection of the lightcuring unit because there was more expansion in the specimens cured using the plasma arc unit than those cured by the other units. (Am J Dent 2010;23:331–334)