Developing Flexible Discrete Event Simulation Models in an Uncertain Policy Environment

On February 1st, 2010 U.S. President Barack Obama submitted to Congress his proposed budget request for Fiscal Year 2011. This budget included significant changes to the National Aeronautics and Space Administration (NASA), including the proposed cancellation of the Constellation Program. This change proved to be controversial and Congressional approval of the program's official cancellation would take many months to complete. During this same period an end-to-end discrete event simulation (DES) model of Constellation operations was being built through the joint efforts of Productivity Apex Inc. (PAl) and Science Applications International Corporation (SAIC) teams under the guidance of NASA. The uncertainty in regards to the Constellation program presented a major challenge to the DES team, as to: continue the development of this program-of-record simulation, while at the same time remain prepared for possible changes to the program. This required the team to rethink how it would develop it's model and make it flexible enough to support possible future vehicles while at the same time be specific enough to support the program-of-record. This challenge was compounded by the fact that this model was being developed through the traditional DES process-orientation which lacked the flexibility of object-oriented approaches. The team met this challenge through significant pre-planning that led to the "modularization" of the model's structure by identifying what was generic, finding natural logic break points, and the standardization of interlogic numbering system. The outcome of this work resulted in a model that not only was ready to be easily modified to support any future rocket programs, but also a model that was extremely structured and organized in a way that facilitated rapid verification. This paper discusses in detail the process the team followed to build this model and the many advantages this method provides builders of traditional process-oriented discrete event simulations

Exploration of an on-site pharmacist intervention within Australian residential aged care facilities using normalisation process theory: A mixed-methods study

Residents living in residential aged care facilities (RACFs) continue to experience medication-related harm. There is ongoing interest in expanding the role of pharmacists, including on-site pharmacists (OSPs), to help improve medication management in RACFs. The objectives of this mixed-methods study were to explore the extent and ways in which on-site pharmacists (OSPs) were normalised within RACFs as part of a complex intervention seeking to improve medication management. This study consisted of semistructured interviews informed by normalisation process theory (NPT) and a quantitative survey adapted from the normalisation measure development questionnaire (NoMAD) instrument which is underpinned by NPT. Semistructured interviews with prescribers, RACF managers, RACF nursing staff, OSPs, residents, and family members (n = 47) indicated that most participants supported OSPs within RACFs that having OSPs in RACFs made sense and was perceived as beneficial and that participants were invested in working with OSPs who often became part of routine practice, i.e., “normalised.” Prescribers, RACF managers, and nursing staff (health care team members) completed the adapted survey, and their responses (n = 16) strongly complemented the positive qualitative findings. Overall, OSPs were positively appraised by health care team members as well as residents and family members and were generally considered to be normalised within their respective RACFs. This study explored the normalisation of OSPs within RACFs. From the perspective of residents, family members, health care team members, and OSPs, OSPs could become part of routine practice within Australian RACFs. The findings of this study also highlighted the value of using theory to guide the evaluation of a pharmacist intervention in RACFs and the utility of applying NPT in a new setting, Australian RACFs. Importantly, the findings of this study could help inform the future role of OSPs working and the rollout of OSPs within Australian RACFs

Ybp1 and Gpx3 signaling in Candida albicans govern hydrogen peroxide-induced oxidation of the Cap1 transcription factor and macrophage escape

Peer reviewedPublisher PD

Magnetic Shape Memory Micro-Pump for Intra-Cranial Drug Delivery

Magnetic shape-memory alloys exhibit strong magneto-structural coupling enabling large magnetic-field-induced deformation. Local control of twinning via variable inhomogeneous magnetic fields initiates local reversible deformation. Previous work produced a valve-less micropump consisting of a Ni-Mn-Ga single crystal, a casing, and a rod magnet. The micropump successfully pumped fluid in opposite directions when the magnet was turned clockwise and counter clockwise. Our current work modifies this micropump for application in rat a head stage, which would simultaneously monitor electroencephalograph data and deliver 0.5-5.0 μl of a drug solution at 100-500 nl/min directly to the rat’s brain. These improvements and the application of the magnetic-shape-memory-alloy technology will foster further improvements in the technology, as well as stimulate further development of MSMA based actuation and sensor devices

The Toxicity of Silver Nanoparticles (AgNPs) to Three Freshwater Invertebrates With Different Life Strategies: Hydra vulgaris, Daphnia carinata, and Paratya australiensis

The toxicity of manufactured nanoparticles varies greatly depending on the test species in consideration and estimates of toxicity may also be confounded by test media in which the organisms are cultured. For a more comprehensive toxicity evaluation, species at different trophic levels or with life strategies, tested in different media should be included. In this study, we examined the toxicity of tyrosine-coated silver nanonparticles (tyr-AgNP) to three Australian freshwater invertebrates: Hydra vulgaris, Daphnia carinata, and Paratya australiensis. Tyr-AgNPs were synthesized, characterized and their behavior was examined in different media used for acute toxicity tests. Additionally, the sensitivity of tested organisms to tyr-AgNPs was compared to ionic silver (Ag+). Based on the LC50 values of both tyr-AgNPs and Ag+ ions at different time points, D. carinata was found to be the most sensitive species followed by P. australiensis and H. vulgaris. NP stability studies revealed that tyr-AgNPs were least stable in hydra medium followed by daphnid and shrimp media. This study demonstrates that significant differences in NP toxicity to aquatic organisms exist and the test media and the life strategy of the species play a key role in these differences. Therefore, it is recommended that a multispecies approach is used in predictive risk assessment of NPs and to ensure protection of native species from possible toxic effects from NPs released into aquatic systems. Also recommended is to carefully investigate the fate and behavior of NPs in different media in assessing NP toxicity and emphasize the need to use native species in developing relevant regulatory frameworks

The toxicity of silver nanoparticles (AgNPs) to three freshwater invertebrates with different life strategies: Hydra vulgaris, Daphnia carinata, and Paratya australiensis

The toxicity of manufactured nanoparticles varies greatly depending on the test species in consideration and estimates of toxicity may also be confounded by test media in which the organisms are cultured. For a more comprehensive toxicity evaluation, species at different trophic levels or with life strategies, tested in different media should be included. In this study, we examined the toxicity of tyrosine-coated silver nanonparticles (tyr-AgNP) to three Australian freshwater invertebrates: Hydra vulgaris, Daphnia carinata, and Paratya australiensis. Tyr-AgNPs were synthesized, characterized and their behavior was examined in different media used for acute toxicity tests. Additionally, the sensitivity of tested organisms to tyr-AgNPs was compared to ionic silver (Ag+). Based on the LC50 values of both tyr-AgNPs and Ag+ions at different time points, D. carinata was found to be the most sensitive species followed by P. australiensis and H. vulgaris. NP stability studies revealed that tyr-AgNPs were least stable in hydra medium followed by daphnid and shrimp media. This study demonstrates that significant differences in NP toxicity to aquatic organisms exist and the test media and the life strategy of the species play a key role in these differences. Therefore, it is recommended that a multispecies approach is used in predictive risk assessment of NPs and to ensure protection of native species from possible toxic effects from NPs released into aquatic systems. Also recommended is to carefully investigate the fate and behavior of NPs in different media in assessing NP toxicity and emphasize the need to use native species in developing relevant regulatory frameworks

Physical investigation into the significance of ground conditions on dynamic leakage behaviour

Effective leakage models are crucial for leakage assessment and control strategies to improve the sustainability of vital water distribution, and other pipeline, infrastructure. This paper evaluates the interdependence of leak hydraulics, structural dynamics and soil hydraulics, particularly considering the significance of the soil conditions external to longitudinal slits in viscoelastic pipe. Initial numerical exploration and unique physical experimental results are presented exploring this complex physical phenomenon. The existence of an idealised fully restrained porous medium was shown to significantly increase the pressure- and time-dependent leak opening area whilst reducing the leak flow-rate, compared to a leak into water only. The research highlights the limitation of existing dynamic leakage modelling approaches which greatly simplify or neglect the influence of the soil conditions. Incorporation of this understanding into leakage modelling will enable more accurate estimation of leakage rates and hence the effects of management and control strategies

North Hermiston Local Circulation Plan

55 pagesThe City of Hermiston is a growing town located in the northeast part of Oregon. In the early 2000s, Hermiston had a population of about 13,000 people. With more homes and schools under construction, the town expects to reach a population of 20,000 in the next decade. Hermiston is a small town, and with a growing population, traffic will increase, causing large amounts of congestion. The congestion will primarily be an issue during peak hours in the morning and afternoon. Most of the congestion occurs on Highway 395. Portland State University capstone students are responsible for designing different alternatives that the team will present to the city of Hermiston. The report will include CAD drawings, a cost estimate, and a construction schedule. The alternative designs will focus on easing congestion, providing better access for residents and commercial establishments, pedestrian and driver safety, and total construction time. During a site visit, the team looked for areas along Highway 395 where drivers could make an earlier turn that would ease up the turning lanes on W Theater Lane and Highway 207. Highway 207 had an issue with an existing business, so the team decided not to evaluate the street for a potential redesign. ODOT had already purchased as much right- of-way as possible in the intersection, but the existing business showed no interest in relocating. No more can be done unless the property is bought and demolished. At an early design stage, the City of Hermiston decided that designing bike lanes was not preferred due to the popularity of using automobiles to get around town. The team ultimately produced three designs that the City could look into, not including a no-build option. The alternatives include a new street layout from Highway 395 to W Theater Lane, a new street layout from Highway 395 to NE 4th Street, and an intersection redesign from W Theater Lane to Highway 395. The team met with stakeholders around the area, and all alternative designs were disclosed. The stakeholders approved of each one. Stakeholders described that congestion was noticeably becoming an issue and wanted a solution. Some stated it was nearly impossible to make a left turn onto Highway 395. Another issue was the safety of employees, as drivers would speed and cut through the parking lots to get around traffic. With stakeholders understanding that redevelopment will occur throughout the city, these problems will worsen if no initiative is taken. After a thorough analysis, the recommended solution to solve the central issue of congestion and safety is to create a new street layout. The new street layout will cut through the privately-owned property to connect Highway 395 to NE 4th Street. The new street layout connecting Highway 395 to NE 4th Street is the best alternative as it will provide the best solution to ease congestion on Highway 395. The new road would also provide better street access to nearby residential areas and discourage the public from entering businesses using their rear entrance. This design will not affect traffic flow but will require right-of-way acquisition from private parties. The City of Hermiston officials approved this design as it would better impact congestion while having a slightly better cost than other design alternatives. In addition to adding a new roadway, swales will be added for drainage, and sidewalks will be constructed for pedestrians. This layout will allow the City to incorporate a new signal at Highway 395