A Paper-Based Elisa Device for the Rapid Detection of Ischemic Stroke

Diagnosing an ischemic stroke quickly and accurately is essential for appropriate treatment and results in more effective management of the stroke, leading to better patient outcomes. Specifically, the determination of ischemic versus hemorrhagic stroke leads to critically different treatment paths, which would be potentially fatal if administered incorrectly. Currently, ischemic strokes are diagnosed through a series of tests, including a physical examination, CT scans, and a panel of blood tests to exclude hemorrhagic stroke or other similarly presenting conditions, in order to administer tPA (the main treatment) within the three hour window. The discovery of biomarkers, molecules which are upregulated during the onset of a specific condition or disease, can be used to diagnose patients when integrated with an appropriate platform. The objective of this thesis was to further develop a paper-based microfluidic device for the rapid detection of ischemic stroke using biomarkers that can be detected in the blood. This device uses HRP-based enzyme linked immunosorbent assay (ELISA) technology on a cellulose paper surface to yield a sensitive (11.8 pM) assay targeting S100B, a protein released by glial cells in the brain during stroke. Wax printing allows for creation of precise hydrophilic pathways in which sample fluid can travel within the 3D microfluidic device to react with a variety of proteins and reagents. This technology has the potential to be implemented globally as a point-of-care device for use in developing countries without consistent or reliable access to advanced diagnostic technology. The device is cheap to produce, portable, and results can be determined quickly and qualitatively analyzed using cell phone images, making it an accessible technology for patients around the globe

SensibleSleep: A Bayesian Model for Learning Sleep Patterns from Smartphone Events

We propose a Bayesian model for extracting sleep patterns from smartphone events. Our method is able to identify individuals' daily sleep periods and their evolution over time, and provides an estimation of the probability of sleep and wake transitions. The model is fitted to more than 400 participants from two different datasets, and we verify the results against ground truth from dedicated armband sleep trackers. We show that the model is able to produce reliable sleep estimates with an accuracy of 0.89, both at the individual and at the collective level. Moreover the Bayesian model is able to quantify uncertainty and encode prior knowledge about sleep patterns. Compared with existing smartphone-based systems, our method requires only screen on/off events, and is therefore much less intrusive in terms of privacy and more battery-efficient

Melatonin as Treatment and Prophylaxis for Alzheimer\u27s Disease

Alzheimer’s is a very prevalent disease that has no true dependable and effective treatment. Through research and trials melatonin has been seen as a potential therapeutic option for both structural and behavioral changes in Alzheimer’s. Studies have shown low levels of natural melatonin in CSF are a strong indicator of Alzheimer\u27s Disease. This suggests melatonin could be used as a prophylactic measure as well as a treatment for slowing the disease’s neuropathological changes. Results showed that melatonin improves circadian rhythm and sleep quality leading to more effective glymphatic clearing of free radicals, improving cognition, and decreasing behavioral disturbances

Determination of convergence rates across the Ventura Basin, Southern California, using GPS and historical triangulation

Comparison of angles from historical triangulation observations dating as far back as 1932 with Global Positions System (GPS) measurements taken in 1987 indicates that rapid convergence may be taking place on decade timescales in the central and eastern part of the Ventura basin, an east-west trending trough bounded by thrust faults. Changes in angles over this time were analyzed using Prescott's modified Frank's method and in terms of a model which assumes that the regions to the north and south of the basin are rigid blocks undergoing relative motion. For the two block model, inversion of the observed angle changes over the last 28 years for the relative motion vector leads to north-south convergence across the basin of 30 + or - 5 mm/yr, with a left lateral component of 10 + or - 1 mm/yr in the Fillmore-Santa Paula area in the central part of the basin. The modified Frank's method yields strain rates of approximately 2 microrad/yr in both the east and central parts of the basin for measurements spanning the 1971 San Fernando earthquake. Assuming no east-west strain yeilds north-south compression of approximately 3.5 + or - .2 cm/yr. Comparison of triangulation data prior to the earthquake shows no strain outside the margin of error. The convergence rates determined by geodetic techniques are consistent with geologic observations in the area. Such large geodetic deformation rates, with no apparent near-surface creep on the major thrust, can be understood if these faults become subhorizontal at relatively shallow depths and if the subhorizontal portions of the faults are creeping. An alternative explanation of the large displacement rates might be that the pumping of oil in the vicinity of the benchmarks caused large horizontal motions, although it is unlikely that meter scale horizontal motions are due to oil withdrawal. These and other hypotheses are evaluated to better constrain the tectonics of this active region

Where can they play? Outdoor spaces and physical activity among adolescents in U.S. urbanized areas

Objective—To estimate behavior-specific effects of several objectively-measured outdoor spaces on different types of moderate to vigorous physical activity (MVPA) in a large, diverse sample of U.S. adolescents. Methods—Using data from Wave I (1994–95) of the National Longitudinal Study of Adolescent Health (U.S., n=10,359) and a linked geographic information system, we calculated percent greenspace coverage and distance to the nearest neighborhood and major parks. Using sex-stratified multivariable logistic regression, we modeled reported participation in wheel-based activities, active sports, exercise, and ≥5 MVPA bouts/week as a function of each outdoor space variable, controlling for individual- and neighborhood-level sociodemographics. Results—Availability of major or neighborhood parks was associated with higher participation in active sports and, in females, wheel-based activity and reporting ≥5 MVPA bouts/week [OR (95% CI): up to 1.71 (1.29. 2.27)]. Greater greenspace coverage was associated with reporting ≥5 MVPA bouts/week in males and females [OR (95% CI): up to 1.62 (1.10, 2.39) for 10.1 to 20% versus ≤10% greenspace] and exercise participation in females [OR (95% CI): up to 1.73 (1.21, 2.49)]. Conclusions—Provision of outdoor spaces may promote different types of physical activities, with potentially greater benefits in female adolescents, who have particularly low physical activity levels

Experiences of Physical Therapists who Participate in Disaster Relief Work in Haiti

Purpose/Hypothesis: Opportunities are now available for physical therapists to move onto the global scene as they become involved in disaster relief work in Haiti. There has been a great deal written in the literature on the experiences and roles of health care providers who participate in disaster relief work. There has been less written about the role of physical therapists who engage in international disaster relief work. Not everyone may understand the challenges faced when participating in disaster relief work in Haiti. The purpose of the study is to describe the experience of physical therapists who have engaged in disaster relief work in Haiti. Materials/Methods: Descriptive phenomenological methods were used to analyze interviews of 11 physical therapists on their experiences of engaging in disaster relief work in Haiti after the earthquake of 2010. Data were collected from two interviews with each participant in order to create the general structure of the experience of not-knowing. The interview transcripts were analyzed using the descriptive approach described by Giorgi (1975, 1997) and Dahlberg, Drew, and Nyström (2002). Descriptive phenomenology was used to describe the experience of participating in disaster relief physical therapy work in Haiti. Results: The essence of the experience of physical therapists engaged in international physical therapy disaster relief work was signified by five constituents that included (a) dealing with emotions: uncertainty and fear (b) facing challenges; (c) education as the key to sustainability; (d) lessons learned (e) being able to articulate the meaning of social responsibility. Conclusions: The structure of participating in disaster relief work as a physical therapist was described as a shocking but rewarding experience which challenges participants to reevaluate their lives and practice of physical therapy. The ability to participate in this type of work seems to enhance the practice of physical therapy back home. By better understanding the physical therapists‟ experience we can better anticipate the kinds of support needed for those who engage in international disaster physical therapy work. We may also better understand the challenge of returning home for those who serve abroad

Corporate social responsibility in the global value chain: a bargaining perspective

Breaches of corporate social responsibility (CSR) in global value chains (GVCs) pose a managerial challenge for multinational enterprises (MNEs) and threaten both their reputations and global sustainability. While an MNE-centric perspective on these issues has dominated existing international business research, we show that a dynamic view of bargaining among actors in the GVC can yield novel insights. We draw on coalitional game theory and develop a model where an MNE collaborates, monitors, and negotiates prices with a supplier whose CSR breaches may be revealed by the MNE, external agents, or remain hidden. Our model illustrates how MNEs may face a hold-up problem when irresponsible actions by suppliers are made public, and the suppliers have the power to engage in opportunistic renegotiation. Interestingly, we show that greater monitoring by MNEs, if not combined with specific strategies, can have negative consequences by weakening the MNE's bargaining position and, in some cases, even prompting more irresponsible actions by the suppliers. Our model advances international business research on GVC sustainability and has important implications for managers and researchers alike