Minimum aberration designs for discrete choice experiments

A discrete choice experiment (DCE) is a survey method that givesinsight into individual preferences for particular attributes.Traditionally, methods for constructing DCEs focus on identifyingthe individual effect of each attribute (a main effect). However, aninteraction effect between two attributes (a two-factor interaction)better represents real-life trade-offs, and provides us a better understandingof subjects’ competing preferences. In practice it is oftenunknown which two-factor interactions are significant. To address theuncertainty, we propose the use of minimum aberration blockeddesigns to construct DCEs. Such designs maximize the number ofmodels with estimable two-factor interactions in a DCE with two-levelattributes. We further extend the minimum aberration criteria toDCEs with mixed-level attributes and develop some general theoreticalresults

Effects of sugar-amendment on bacterial & fungal abundance in native vs. nonnative-dominated soils of a Puget lowland prairie

Scotch broom is a nonnative plant that has invaded the plant communities of the Pacific Northwest in the United States. It associates with bacteria in the soil to fix nitrogen from the atmosphere, thereby elevating soil nitrogen levels and encouraging the invasion of the community by other nonnative plants like itself. Researchers have used sugar-amendment to decrease soil nitrogen and restore native plant growth. Our study took place in Glacial Heritage Preserve, a Puget lowland prairie that has been invaded by broom in several areas. We aimed to investigate whether sugar-amendment increased or decreased bacterial and fungal abundance in native versus broom-dominated soils of the prairie. We plan on using quantitative PCR (qPCR) to measure abundance and have currently optimized fungal primers for this purpose. During this study, we also collected data on soil nitrate to later compare with abundance data. Optimization of bacterial primers and further abundance data collection is forthcoming. Through this work, we hope to elucidate more about plant-microbial interactions and understand the effectiveness of sugar-amendment as a means of native plant restoration

Exploring the effects of C-amendment on the soil microbial community in a Puget lowland prairie

Scotch broom is a non-native plant that has invaded plant communities worldwide. Able to grow on a variety of soil conditions, Scotch broom associates with soil bacteria to fix nitrogen (N) from the atmosphere, elevating soil N and crowding out native plant species by encouraging the growth of non-natives like itself. Adding carbon (C) has been used in previous studies to lower soil N and restore native plant growth. However, little is known about C-amendment’s effects on the soil microbial community that correspond to changes in soil N and plant community composition. Recent studies have shown that C-amendment increases microbial populations in soil. Researchers propose that C-amendment affects certain species of soil bacteria at different times after treatment. Given this model of C-amendment’s effects, we hypothesize that there should be a detectable change in the dominance of certain species within the total soil microbial community. Soil samples were collected from sugar-treated and untreated plots at Glacial Heritage Preserve, a Puget lowland prairie site in Olympia, WA. Our study investigates how C-amendment affects the functionality of the soil microbial community in a Puget lowland prairie invaded by Scotch broom using BIOLOG ecoplates

Implications for Old-field Restoration: Diversity and abundance of Arbuscular Mycorrhizal Fungi in Soils of Restored York Gum (Eucalyptus loxophleba subsp. loxophleba) Sites vs. Remnants.

Arbuscular mycorrhizal fungi (AMF) may be critical to the restoration of ecosystem function in old-fields. Whether the diversity of the plant community is promoted by the AMF community or is the driving force of AMF diversity is unknown. We investigated two questions in the context of old-field restoration in southwestern Australia: 1) Does restoration of the plant community achieve the restoration of AMF and 2) Is AMF species diversity and abundance influenced by the plant species composition? Our study sites were located in the Ridgefield Experiment in the University of Western Australia’s “Future Farm”. Soil samples were collected from beneath York gum trees (Eucalyptus loxophleba subsp. loxophleba) in restored sites of varying plant species diversity and York gums in adjacent remnants. A total of 36 samples (nine per experimental treatment) were collected. AMF spores were extracted from each sample via centrifugation-sugar flotation method and examined under a dissecting microscope. Mean spore abundance of bare plot soils (331 spores/100 g soil ± 100 spores (S.E)) differed significantly from the abundances of the other three treatment soils (ANOVA, p=0.04). AMF species richness and Shannon-Wiener diversity indices did not differ significantly among treatments. Differences in mean percent abundance of individual species were observed. We conclude that AMF species can be found in restored plant communities of old-fields and that the restoration of the AMF community in old-fields will likely depend on the restoration of the plant community in conjunction with the restoration of other abiotic factors

Risk-Management Approaches in the Post 9/11 Era: A Case Study of Security Provisions within the Context of the US

In the aftermath of 9/11, a heightened development of security provisions within the United States of America (US) has been observed. This thesis seeks to study how these security provisions have influenced the process of a securitization of migration and the conceptualization of migrants within the US. This research paper applies Foucault’s notion of biopower to study this issue by examining risk-management approaches consisting of enhanced border security, public surveillance and the use of biometrics. A content analysis on post 9/11 security measures include the Homeland Security Act of 2002 and the United States Visitor and Immigrant Status Indicator Technology program in order to study the immense power these security provisions hold. Results show that these policies and programs have subsequently framed certain bodies, specifically individuals from Arab and Muslim states as a threatening Other. This is further highlighted after examining migration trends of nonimmigrant students and temporary visitors entering the US from Southeast Asia, South America and the Middle East. After 9/11 an observable decrease in admissibility is most notable in the Middle East in contrast to Southeast Asia and South America. This holds various ethical implications as it can lead to a cultural polarization within the society

Caídas en pacientes ingresados en el Servicio de Atención Médica Integral (saMI)

[ES] •Antecedentes: Las caídas en personas de edad avanzada son muy frecuentes, con gran impacto en la autonomía y calidad de vida del paciente. Producen un aumento de la morbi-mortalidad. Su etiología es multifactorial, con factores modificables y no factores modificables. •Objetivos: Conocer los diferentes factores que influyen en la probabilidad de sufrir una caída en el anciano mediante una revisión bibliográfica, y compararlos con los datos de pacientes ingresados en el Servicio de Atención Médica Integral (sa-MI). •Métodos: Se realizó una meta-revisión o revisión paraguas sobre los factores de riesgo o predictores de caída en la población anciana y una evaluación de los datos de 247 pacientes hospitalizados en el Servicio de Atención Médica Integral (saMI) ubicado en el edificio Santiago del Servicio de Medicina del Hospital Universitario de Álava. •Resultados: La búsqueda bibliográfica dio como resultado la identificación de 7127 artículos, de los cuales se incluyó 13 revisiones sistemáticas. De los 247 pacientes evaluados, 55 pacientes ingresaron por caídas. La edad media fue de 85.73 (± 5.99) y el 39.5% vivían solos. De la revisión bibliográfica, los factores que se asociaron con mayor riesgo de caída fueron: el ‘antecedente previo de caídas’, determinados fármacos (psicotrópicos, diuréticos, antidepresivos, …), ‘depresión’, ‘ansiedad’, ‘dolor’, ‘pérdida de audición y visión’, ‘deterioro cognitivo’, ‘deterioro de la función ejecutiva’, determinadas enfermedades crónicas (Parkinson, enfermedad reumática, diabetes, …), y ‘limitación física’. Del estudio descriptivo, el factor que se asociación a más riesgo de caída fue ‘tener menor capacidad física’, y con menor riesgo fueron ‘no tomar antiagregantes’, ‘no vivir solo’, y ‘no tomar hipolipemiantes’. •Conclusiones: Las caídas en personas de edad avanzada se deben a diversos factores de riesgo. Todo ello justifica la necesidad de intervenciones multi-disciplinares y multi-estratégicas, como es la mejora de la capacidad funcional fomentando el ejercicio, plantear la necesidad de recursos sociales en ancianos que vivan solos, y revisar la medicación mediante los criterios STOPP/START