OMAE2006-92201 OPTIMIZING SHIP MACHINERY MAINTENANCE SCHEDULING THROUGH RISK ANALYSIS AND LIFE CYCLE COST ANALYSIS

ABSTRACT Ship maintenance scheduling management integrated with risk evaluation and Life Cycle Cost (LCC) assessment approach is developed in this research. It improves upon existing practices in arranging an optimal maintenance schedule by modeling operational and economical risks. This paper researches maintenance scheduling algorithm with explicitly consider risks associated with some operation problems such as operating schedule, routes, ship position, resources availability, and achievement of reliability-availability-maintainability (RAM) of system. Modeling of components RAM with their failures consequences results risk evaluation. Time value of maintenance cost, replacement cost, earning rate, and penalty cost are also simulated. When the system reaches the lowest level of lower limit reliability, one or more components should be maintained or replaced. Since maintenance task may interrupt the operation, to minimize time-to-maintain all possible events of maintaining other components at the same time will be evaluated together with resources availability. By researching those possibilities, constraining the risk, and based on LCC calculation result, an optimal maintenance scheduling can be then well established

Socio-Emotional Resilience Among Older Adults During the COVID-19 Pandemic

The detrimental impact of social isolation on health and well-being has been reported in older adults (Prohaska, et al., 2020). Yet findings also demonstrate that older adults have a motivational shift to prioritize emotionally meaningful goals and experiences (Carstensen, 1993; Sakaki, et al., 2019), prioritize emotional meaning in situations, focus on positive emotions and stimuli over negative feelings and live in the present rather than focus on future preparedness. Socioemotional selectivity theory (SST) (Carstensen, 1993; Carstensen, Fung & Charles, 2003) suggests that older adults have a limited sense of time left in life and shift their focus to meaningful and positive experiences. Due to the COVID-19 pandemic most individuals became physically separated from family, friends and social activities that are so important to overall well-being. To explore the contradicting evidence in the literature about detrimental effects of social isolation and the SST theory, we conducted semi-structured interviews with 21 older adults ranging in age from 62 to 86 years old to explore their experiences during the pandemic and specifically to address emotional well-being, social experiences and coping mechanisms. Qualitative analyses revealed themes of problem-solving and emotion-focused coping, social support, and meaning making with ample evidence of the positivity effect. These findings support the SST theory as many participants expressed great resilience as they discussed how they engaged in emotionally meaningful activities and experiences and even made the best of adverse experiences during the pandemic

Intestinal Subepithelial Myofibroblasts Support in vitro and in vivo Growth of Human Small Intestinal Epithelium

The intestinal crypt-niche interaction is thought to be essential to the function, maintenance, and proliferation of progenitor stem cells found at the bases of intestinal crypts. These stem cells are constantly renewing the intestinal epithelium by sending differentiated cells from the base of the crypts of Lieberkühn to the villus tips where they slough off into the intestinal lumen. The intestinal niche consists of various cell types, extracellular matrix, and growth factors and surrounds the intestinal progenitor cells. There have recently been advances in the understanding of the interactions that regulate the behavior of the intestinal epithelium and there is great interest in methods for isolating and expanding viable intestinal epithelium. However, there is no method to maintain primary human small intestinal epithelium in culture over a prolonged period of time. Similarly no method has been published that describes isolation and support of human intestinal epithelium in an in vivo model. We describe a technique to isolate and maintain human small intestinal epithelium in vitro from surgical specimens. We also describe a novel method to maintain human intestinal epithelium subcutaneously in a mouse model for a prolonged period of time. Our methods require various growth factors and the intimate interaction between intestinal sub-epithelial myofibroblasts (ISEMFs) and the intestinal epithelial cells to support the epithelial in vitro and in vivo growth. Absence of these myofibroblasts precluded successful maintenance of epithelial cell formation and proliferation beyond just a few days, even in the presence of supportive growth factors. We believe that the methods described here can be used to explore the molecular basis of human intestinal stem cell support, maintenance, and growth

A randomized trial of memantine as treatment for spasticity in multiple sclerosis

Abstract We report the results of a single center randomized, double-blind, placebo-controlled, parallel group trial of memantine in adults with multiple sclerosis and spasticity conducted over 12 weeks. Eligible MS patients had to have an Ashworth spasticity rating of 2 or higher in at least one lower extremity muscle group. Subjects were randomized to receive either placebo or memantine 10 mg twice a day. The primary outcome measure for efficacy was the change in Ashworth Spasticity Scale Score. Although well tolerated, memantine treatment did not demonstrate efficacy in treatment of spasticity in this 12-week small exploratory study