An Optimization of the Hub-and-Spoke Distribution Network in United States European Command

The development of Expeditionary Aerospace Force (EAF) operations requires rethinking of many Air Force functions. A Logistics Transformation Team, comprising Air Force and KPMG Consulting Incorporation personnel, is leading much of this transformation work. The very first step of the transformation initiatives is demand planning, which is the process of translating the war fighter\u27s needs into executable logistics support plans and schedules. One important area that the demand planning focuses on is engine maintenance. This sub-mission is assigned to the F101 Engine Pathfinder Team, which is responsible for increasing the availability of the F101 engine. As part of the F101 Engine Pathfinder Team\u27s effort, the focus of this thesis is to apply Modeling and Simulation (M&S), Response Surface Methodology (RSM), and Linear Programming (LP) to examine ways to reduce repair cycle time and work in process (WIP) investment for the F101 Low Pressure Turbine (LPT) rotor. We specifically evaluate a variety of job scheduling policies and spare levels

Toward the Understanding of Organizational Flexibility

Contingency planning is widely touted as a method of preparing for and confronting disruptions to organizational activity; its attributes are proposed to promote organizational flexibility. This study examines the relationship between information sharing, internal and external collaboration, and information technology use and organizational flexibility and develops a model that will provide both academicians and practitioners with a means of determining the attributes with the highest relationship to organizational flexibility. This knowledge will allow for prioritization of resources in the planning process. A survey of 50 professionals from various sectors of the government is used to test the hypotheses developed

Facilitating Flexibility in Supply Chain Organizations: The Confounding Effect of Information

As globalization continues to create interdependencies, organizations find themselves exposed to multiple vulnerabilities that may result in disruption of organizational activity. Contingency planning is widely touted as a method of dealing with and preparing for such interruptions. This risk management technique has many attributes that promote organizational flexibility; however, the effect of information technology on those attributes is not well understood. Accordingly, this study examines the effect of information technology on inter-organizational collaboration, intra-organizational collaboration, and information sharing and their respective relationships with organizational flexibility

Multi-study analysis of learning culture, human capital and operational performance in supply chain management: The moderating role of workforce level

Purpose – The purpose of this study is to empirically evaluate the relationship between learning culture, workforce level, human capital and operational performance in two diverse supply chain populations, aircraft maintenance and logistics readiness. Design/methodology/approach – Drawing upon competence-based view of the firm and human capital theory, this paper analyzes data from two studies. Findings – The results provide support for the hypothesized model. Workforce level moderates the relationship between learning culture and human capital, and human capital partially mediates the relationship between learning culture and operational performance. Research limitations/implications – The findings have implications for behavioral supply chain management research and implications for educating and training the supply chain management workforce. While the populations represent a diverse set of logistics functions and responsibilities, the participants are all military members, which may limit generalizability. Practical implications – This study should help leaders understand the importance of learning culture and the perceived differences in its effect on human capital based upon workforce level. Originality/value – This research is among the first to investigate the role of workforce level and answers a multitude of calls for research into the human side of supply chain management

Forward positioning and consolidation of strategic inventories

The forward positioning of strategic inventory in the supply chain has an impact on transportation times and is important for sensitive demand profiles. Consolidation of stocks creates pooling effects and minimizes costs. This study analyzes a current military case where forward consolidation of equipment is considered using optimization, and payback periods are calculated for the cost of consolidating inventory at one of six locations. Results indicate that forward positioning and consolidation reduces time and cost, and also creates savings in reverse logistics flows. The study has implications for geographically diverse supply chains such as humanitarian aid and emergency response operations

Analytical techniques and the Air Force logistics readiness officer

The accelerated globalization of logistics activities over the last several decades has spurred a rapid expansion of port facilities all cross the world. However, the recent slowdown of international trade, coupled with a global financial crisis, has created an on-going glut of international port facilities throughout the world. Although the abundance of port facilities provides more transshipment options for carriers and shippers, it makes the port selection decision more complex and difficult. To cope with this new set of challenges, this paper proposes a hybrid data envelopment analysis (DEA)/ analytic hierarchy process (AHP) model that is designed to identify factors specifically influencing transshipment port selection, evaluates the extent of influence of those factors on a transshipment port selection decision, and then determines the most critical ones among various factors. To illustrate the usefulness of the proposed hybrid DEA/AHP model, major container hub ports in Far-East Asia were analyzed

Baseline Cytomegalovirus Viremia at Cryptococcal Meningitis Diagnosis Is Associated With Long-term Increased Incident TB Disease and Mortality in a Prospective Cohort of Ugandan Adults With HIV.

BACKGROUND: Adults with HIV-associated cryptococcal meningitis have overlapping burdens of cytomegalovirus (CMV) and tuberculosis (TB) coinfections. CMV infection/reactivation is strongly associated with CMV-specific memory T-cell activation and upregulation of type 1 interferons, which may lead to increased risk of TB disease and poor outcomes. METHODS: We conducted a cohort study of 2-week survivors of cryptococcal meningitis during 2010-2021 to determine TB incidence and all-cause mortality over time stratified by baseline CMV status. RESULTS: We followed 497 Ugandans with HIV-associated cryptococcal meningitis for a median (interquartile range) of 4.6 (2.6-53.9) months. Overall, 42% (210/497) developed incident TB disease or died. One-fifth (98/497, 19.7%) developed incident TB disease, and 29% (142/497) of participants died during follow-up. Of 259 participants with CMV viral load measured at baseline, 37% (96/259) had concurrent CMV viremia (defined as anyone with detectable CMV DNA in plasma/serum by qualitative polymerase chain reaction [PCR] detection). Of 59 with measured CMV immunoglobulin G (IgG), 100% had positive CMV IgG antibody serology (≥10 enzyme-linked immunosorbent assay units/mL). CMV viremia was positively associated with higher HIV viral load (196 667 vs 73 295 copies/mL; P = .002) and higher cerebrospinal fluid fungal burden (68 500 vs 14 000 cfu/mL; P = .002) compared with those without. Participants with high-level CMV viremia (defined as CMV viral load ≥1000 IU/mL) had twice the risk of incident TB (subdistribution adjusted hazard ratio [aHR], 2.18; 95% CI, 1.11-4.27) and death (aHR, 1.99; 95% CI, 1.14-3.49) compared with participants with no or low-level CMV viremia. There was no association between the CMV IgG index and the incidence of TB/death (P = .75). CONCLUSIONS: CMV viremia >1000 IU/mL at meningitis diagnosis was associated with increased incident TB disease and mortality during long-term follow-up. Future studies to determine the causal relationship and potential for therapeutic intervention are warranted

Large-Scale Pathway-Based Analysis of Bladder Cancer Genome-Wide Association Data from Five Studies of European Background

Pathway analysis of genome-wide association studies (GWAS) offer a unique opportunity to collectively evaluate genetic variants with effects that are too small to be detected individually. We applied a pathway analysis to a bladder cancer GWAS containing data from 3,532 cases and 5,120 controls of European background (n = 5 studies). Thirteen hundred and ninety-nine pathways were drawn from five publicly available resources (Biocarta, Kegg, NCI-PID, HumanCyc, and Reactome), and we constructed 22 additional candidate pathways previously hypothesized to be related to bladder cancer. In total, 1421 pathways, 5647 genes and ∼90,000 SNPs were included in our study. Logistic regression model adjusting for age, sex, study, DNA source, and smoking status was used to assess the marginal trend effect of SNPs on bladder cancer risk. Two complementary pathway-based methods (gene-set enrichment analysis [GSEA], and adapted rank-truncated product [ARTP]) were used to assess the enrichment of association signals within each pathway. Eighteen pathways were detected by either GSEA or ARTP at P≤0.01. To minimize false positives, we used the I2 statistic to identify SNPs displaying heterogeneous effects across the five studies. After removing these SNPs, seven pathways (‘Aromatic amine metabolism’ [PGSEA = 0.0100, PARTP = 0.0020], ‘NAD biosynthesis’ [PGSEA = 0.0018, PARTP = 0.0086], ‘NAD salvage’ [PARTP = 0.0068], ‘Clathrin derived vesicle budding’ [PARTP = 0.0018], ‘Lysosome vesicle biogenesis’ [PGSEA = 0.0023, PARTP<0.00012], ’Retrograde neurotrophin signaling’ [PGSEA = 0.00840], and ‘Mitotic metaphase/anaphase transition’ [PGSEA = 0.0040]) remained. These pathways seem to belong to three fundamental cellular processes (metabolic detoxification, mitosis, and clathrin-mediated vesicles). Identification of the aromatic amine metabolism pathway provides support for the ability of this approach to identify pathways with established relevance to bladder carcinogenesis

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

Background: The EMPA KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population. Methods: EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110. Findings: Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5–2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62–0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16–1·59), representing a 50% (42–58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all &gt;0·1). Interpretation: In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease. Funding: Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council

The Science Performance of JWST as Characterized in Commissioning

This paper characterizes the actual science performance of the James Webb Space Telescope (JWST), as determined from the six month commissioning period. We summarize the performance of the spacecraft, telescope, science instruments, and ground system, with an emphasis on differences from pre-launch expectations. Commissioning has made clear that JWST is fully capable of achieving the discoveries for which it was built. Moreover, almost across the board, the science performance of JWST is better than expected; in most cases, JWST will go deeper faster than expected. The telescope and instrument suite have demonstrated the sensitivity, stability, image quality, and spectral range that are necessary to transform our understanding of the cosmos through observations spanning from near-earth asteroids to the most distant galaxies.Comment: 5th version as accepted to PASP; 31 pages, 18 figures; https://iopscience.iop.org/article/10.1088/1538-3873/acb29