Asynchronous CDMA Systems with Random Spreading-Part I: Fundamental Limits

Spectral efficiency for asynchronous code division multiple access (CDMA) with random spreading is calculated in the large system limit allowing for arbitrary chip waveforms and frequency-flat fading. Signal to interference and noise ratios (SINRs) for suboptimal receivers, such as the linear minimum mean square error (MMSE) detectors, are derived. The approach is general and optionally allows even for statistics obtained by under-sampling the received signal. All performance measures are given as a function of the chip waveform and the delay distribution of the users in the large system limit. It turns out that synchronizing users on a chip level impairs performance for all chip waveforms with bandwidth greater than the Nyquist bandwidth, e.g., positive roll-off factors. For example, with the pulse shaping demanded in the UMTS standard, user synchronization reduces spectral efficiency up to 12% at 10 dB normalized signal-to-noise ratio. The benefits of asynchronism stem from the finding that the excess bandwidth of chip waveforms actually spans additional dimensions in signal space, if the users are de-synchronized on the chip-level. The analysis of linear MMSE detectors shows that the limiting interference effects can be decoupled both in the user domain and in the frequency domain such that the concept of the effective interference spectral density arises. This generalizes and refines Tse and Hanly's concept of effective interference. In Part II, the analysis is extended to any linear detector that admits a representation as multistage detector and guidelines for the design of low complexity multistage detectors with universal weights are provided

Asynchronous CDMA Systems with Random Spreading-Part II: Design Criteria

Totally asynchronous code-division multiple-access (CDMA) systems are addressed. In Part I, the fundamental limits of asynchronous CDMA systems are analyzed in terms of spectral efficiency and SINR at the output of the optimum linear detector. The focus of Part II is the design of low-complexity implementations of linear multiuser detectors in systems with many users that admit a multistage representation, e.g. reduced rank multistage Wiener filters, polynomial expansion detectors, weighted linear parallel interference cancellers. The effects of excess bandwidth, chip-pulse shaping, and time delay distribution on CDMA with suboptimum linear receiver structures are investigated. Recursive expressions for universal weight design are given. The performance in terms of SINR is derived in the large-system limit and the performance improvement over synchronous systems is quantified. The considerations distinguish between two ways of forming discrete-time statistics: chip-matched filtering and oversampling

Rating College Debt: A Case Study of Union College

On Friday March 3rd President Stephen Ainlay made an announcement of \u27the largest most expensive most complex project in Union\u27s history.\u27 President Ainlay is referencing the massive rebirth of one of Union\u27s most central academic buildings Science and Engineering. The three-phrase building project will take an estimated three years and cost a total of $100 million. About$50 million of this project will be financed through debt. This comes at a time when Moody\u27s a top rating agency changed the methodology for rating higher education debt. My thesis explores the impact of the new methodology on Union\u27s rating. While the elimination of some criteria like matriculation and selectivity may help Union\u27s rating the addition of other criteria like total wealth negatively impact Union\u27s standing. I find that even after including $50 million of new debt Union should retain its A1 rating. To strengthen Union\u27s case for an A1 rating I conduct a peer comparison to help Union navigate Moody\u27s new rating methodology. I also explore potential ways to structure the additional debt and discuss the pros and cons of each option

Clinical Effects of Daily Rotary Electric Toothbrushing on the Presence of Gingivitis and Supragingival Dental Plaque

The purpose of this investigation was to determine if statistically significant differences existed in the gingival health of subjects who brushed with a rotary electric toothbrush (Rota-dentR when compared to a conventional toothbrush (Oral B-35R). A randomized, two group research design was employed using forty subjects. At baseline and at two week intervals for six weeks, gingivitis and supragingival dental plaque were measured by the Loe and Silness Gingival Index and the O\u27Leary Plaque Index, respectively. Multivariate analysis revealed that the Rota-dentR was superior to the conventional toothbrush in reducing dental plaque accumulation and equally effective at reducing gingival inflammation. When area specific multivariate analysis was performed, superiority of the Rota-dentR at reducing gingival inflammation in the anterior region was found. Results suggest that the Rota-dentR is a safe and effective home care device when utilized properly

The Impact of a Community based Exercise Program on Somali Immigrants Residing in Subsidized Housing in Minnesota

Purpose: The Somali immigrant population is a growing demographic in Minnesota. Although immigrants to the United States tend to be healthier upon arrival than the general population, their health deteriorates the longer they reside in the United States, with changes in diet and physical activity as contributing factors. This study explored the effects of a physical therapy student-led exercise program on Somali immigrants residing in Minnesota. Methods: Qualitative data were gathered using audiotaped focus group interviews. Eight female and five male Somali individuals were recruited from an existing exercise program within a subsidized housing complex in Minneapolis, Minnesota. A Somali interpreter provided translation services. Audiotapes were transcribed and data were coded using an inductive approach, with no predefined coding criteria or hypotheses, to generate categories from the raw interview data. Results: Six major themes were identified from the data. These include: physical effects; emotional effects; integration of cultures; barriers and facilitators of participation; differences in physical activity between Somalia and the United States; and transferability of the exercise program. Emotional effects and cultural integration, rather than physical effects of the exercise program were found to be the primary benefit in participants’ responses. Conclusion: The effects of participation in this student-led exercise program are consistent with findings from existing literature of programs designed for immigrant populations. This study adds to the existing literature by demonstrating the importance of connectedness between participants and group facilitators. Results and recommendations from this study can be utilized for future exercise programming initiatives with the immigrant Somali community in the United States

Improving Restraint Feasibility through Ambulance Layout Redesign

This study examined the duties performed by emergency medical service workers with the goal of increasing the time EMS workers are restrained while providing patient care during transport. An optimal layout of equipment and materials in the rear patient cabin of an ambulance was created increase seatbelt restraint feasibility for working medics. Over 13,000 EMS agency call logs were evaluated to identify medical procedures frequently performed during patient transports, which were then filmed and analyzed using Pareto and link analysis to measure restraint feasibility. An alternative ambulance layout was developed following focus group meetings, and the adjusted tasks restraint feasibilities were calculated for the alternative layout. Restraint feasibility was significantly increased for the 5th percentile female, 50th percentile male, and 95th percentile male anthropometric populations. The proposed patient compartment design increased overall restraint feasibility from 47 percent to 90 percent. The proposed design would increase safety for medics and patients during patient transports by increasing the number of tasks that could be performed from a belted and seated position

Building Climate Resilience at NASA Ames

NASA Ames Research Center, located at the southern end of the San Francisco Bay (SFB) estuary has identified three primary vulnerabilities to changes in climate. The Ames Climate Adaptation Science Investigator (CASI) workgroup has studied each of these challenges to operations and the potential exposure of infrastructure and employees to an increased frequency of hazards. Sea level rise inundation scenarios for the SFB Area generally refer to projected scenarios in mean sea level rather than changes in extreme tides that could occur during future storm conditions. In the Summer of 2014, high resolution 3-D mapping of the low lying portion of Ames was performed. Those data are integrated with improved sea level inundation scenarios to identify the buildings, basements and drainage systems potentially affected. We will also identify the impacts of sea level and storm surge effects on transportation to and from the Center. This information will help Center Management develop future Master Plans. Climate change will also lead to changes in temperature, storm frequency and intensity. These changes have potential impacts on localized floods and ecosystems, as well as on electricity and water availability. Over the coming decades, these changes are going to be imposed on top of ongoing land use and land cover changes, especially those deriving from continued urbanization and increase in impervious surface areas. These coupled changes have the potential to create a series of cascading impacts on ecosystems, including changes in primary productivity and disturbance of hydrological properties and increased flood risk.The majority of the electricity used at Ames is supplied by hydroelectric dams, which will be influenced by reductions in precipitation or changes in the timing or phase of precipitation which reduces snow pack. Coupled with increased demand for summertime air conditioning and other cooling needs, NASA Ames is at risk for electricity shortfalls. To assess the anticipated energy usage as climate changes, the Ames CASI team is collecting historical energy usage data from Ames facilities, historical weather data, and projected future weather parameters from the CASI Climate subgroup. This data will be incorporated into the RETScreen model to predict how energy usage at Ames will change over the coming century

Hospital Community Benefits After the ACA: The Emerging Federal Framework

Outlines the federal framework on requirements for hospitals to provide community benefit activities in exchange for tax-exempt status under the 2010 healthcare reform, including community health needs assessments; state policy options; and challenges

The Continuing Impacts of the COVID-19 Pandemic in the United States: Findings from the 2021 Guttmacher Survey of Reproductive Health Experiences

The COVID-19 pandemic is a public health crisis with major ramifications for people's personal lives, including their sexual and reproductive health. In early May 2020, we surveyed a national sample of cisgender women in the 2020 Guttmacher Survey of Reproductive Health Experiences (GSRHE). We found that just a few months into the COVID-19 pandemic, there were profound changes to respondents' sexual and reproductive health goals and behaviors and their access to care.1 Other early studies validated these findings.2,3 Since May 2020, the course and impact of the pandemic have shifted, due to vaccination rates, new variants and relaxed restrictions. To provide an updated look at the ongoing impact of the pandemic on sexual and reproductive health, we fielded another national survey during July and August of 2021. The 2021 GSRHE had a substantially larger sample size than the previous one and was designed to include individuals with a broader range of gender identities. The expanded sample allows us to examine variations in several new, key areas, including gender identity, Asian and Pacific Islander racial identity, and the intersection of race and income.In this report, we analyze the 2021 data, focusing on how respondents feel the COVID-19 pandemic has influenced their sexual and reproductive health in two core areas: fertility preferences and access to care, including use of telehealth. We note disparities according to individuals' race and ethnicity, sexual orientation, gender identity, income level and economic well-being. To assess the ongoing scope and magnitude of the impacts of the pandemic, we also examine findings on comparable measures from the 2020 and 2021 GSRHE studies

Webbing clothes moth, Tineola bisselliella (Hummel) sex pheromone transfer from monitoring lures to textiles: Poster

The use of synthesized sex pheromone lures for the purpose of monitoring populations of webbing clothes moth, Tineola bisselliella (Hummel) in museum storage environments is typical in many museums. Questions about whether the pheromone incorporated in the dispensing lures could possibly transfer over to textiles that are in close proximity to the lures have been posed by museum conservators. Although some textiles may be naturally attractive to clothes moths, the concerns are that the textiles themselves may become even more attractive to insects due to exposure to the pheromone and that this could ultimately cause further damage to the collections. The focus of this study was to determine the degree to which textiles that have been exposed to pheromone lures absorb the pheromone and become attractive themselves. Based on the results of this study, the textiles observed here have little to no additional attraction to insect pests after focused exposure to synthetic pheromone lures over a two-week period.The use of synthesized sex pheromone lures for the purpose of monitoring populations of webbing clothes moth, Tineola bisselliella (Hummel) in museum storage environments is typical in many museums. Questions about whether the pheromone incorporated in the dispensing lures could possibly transfer over to textiles that are in close proximity to the lures have been posed by museum conservators. Although some textiles may be naturally attractive to clothes moths, the concerns are that the textiles themselves may become even more attractive to insects due to exposure to the pheromone and that this could ultimately cause further damage to the collections. The focus of this study was to determine the degree to which textiles that have been exposed to pheromone lures absorb the pheromone and become attractive themselves. Based on the results of this study, the textiles observed here have little to no additional attraction to insect pests after focused exposure to synthetic pheromone lures over a two-week period