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Multidisciplinary Approach to Address Water Scarcity in Informal Settlements in Lima, Peru: Fog Water Collection, The Fog Resource and the Health Context
No full textThesis (Ph.D.)--University of Washington, 2014Many arid regions of the world have very limited and shrinking water availability, which puts vulnerable populations such as informal settlement (slum) dwellers at risk for having the least access to clean drinking water. This is particularly a concern in coastal Peru, where many informal settlements already experience water scarcity that will be exacerbated by both shrinking water supply and a continuously growing population. In Lima, the capital city, rapid growth of the population has resulted in large informal settlements forming up the hillsides surrounding the city. Given the projected growth of Lima, the public water supply has already been found to be inadequate to supply the current water needs of Lima. In order to address this complex problem of inadequate water resources in the informal settlements in Lima, Peru, this dissertation focused on relevant technological, social and environmental factors. The first study demonstrated the improved effectiveness of a nonwoven three-dimensional turf mesh in a passive fog collection system that captures the abundant wind-blown fog that surrounds the city. The material increased yields over traditional fog collection materials by 50% to 150% in field testing. The second focus was on the impact on health and social factors that could be affected by improved water access, as well as have an influence on the ability to develop and sustain any water resource system. Therefore, the second study evaluated demographic, physical and mental health, and social relationship factors of individuals in the community that would be benefit from the fog water collection. We found nearly half of the participants in the community were overweight or obese, yet the prevalence of non-communicable disease was low, and the mental health and social relationship surveys did not indicate significant impacts for the well-being of the community, which may positively contribute to the likelihood of a fog collection system's success. Finally, the fog resource can be assessed by the coastal low cloud conditions. Knowledge about the availability and predictability of these conditions along coastal Peru was explored as the third component of this dissertation. Reduced quantities of stratus clouds were observed with increased temperatures in the El Niño 3.4 region, the El Niño 1+2 region and along coastal Peru. While annually greater quantities of stratocumulus clouds were generally observed with increased El Niño 3.4 temperatures, we observed a negative correlation between seasonal stratocumulus in many coastal Peruvian stations and SST in the El Niño index regions and along coastal Peru. With projected increases in equatorial sea surface temperatures, and warming coastal Peruvian currents, we could see reductions in low cloud cover. In conclusion, by testing efficiency improvements to a method to acquire atmospheric water, exploring individual and social conditions within the type of community where this system could be used, and evaluating conditions that would affect the availability of water throughout the year, this dissertation has contributed to our understanding of many aspects of the problem of water resources in this under-served community. Furthermore, this series of studies has provided direction to the development of community-based water solutions in Lima, Peru
DIFFERENTIAL EFFECTS OF FATTY ACIDS ON AN IN VITRO MODEL OF HEPATOCYTE STEATOSIS
No full textThesis (Master's)--University of Washington, 2014Differential Effects of Fatty Acids on an In Vitro Model of Hepatocyte Steatosis Introduction: Non-alcoholic fatty liver disease (NAFLD) is characterized by excess hepatic fat accumulation in the setting of metabolic syndrome. It ranges from simple hepatic fat accumulation (steatosis), to steatosis with inflammation and fibrosis (steatohepatitis), to end-stage liver disease. Progression of NAFLD has been modeled by a 2 hit hypothesis. The first hit, characterized by triglyceride accumulation, sensitizes the hepatocyte to second hits such as inflammation. Dietary fats are an important contributor to the development of NAFLD. While saturated fatty acids (SFA) tend to promote NAFLD, poly-unsaturated fatty acids (PUFA) and ruminant trans-fatty acids (TFA), such as conjugated linoleic acid (CLA) may be protective. This study aims to investigate the effects of various fatty acids (FA) on hepatocyte triglyceride accumulation, inflammation and insulin sensitivity using an in vitro model. Methods: AML12 hepatocytes were chronically exposed to FAs including Palmitic acid (PA), Oleic acid (OA), Docosahexanoic Acid (DHA) and CLA t10, c12 (CLA 10,12). Hepatic triglyceride content, inflammatory, lipogenic, oxidative stress and ER stress gene expression and insulin signaling proteins were measured. Results: AML12 cells chronically exposed to FA visibly accumulated lipid droplets. Among the various FA treatments, CLA (10,12) induced the greatest triglyceride accumulation. DHA significantly decreased the expression of the lipogenic, inflammatory, oxidative and ER stress genes independent of effects on insulin sensitivity. Interestingly, CLA (10,12) had protective effects on gene expression similar to DHA. Conclusion: Chronic exposure of dietary FA promotes triglyceride accumulation in this in vitro hepatocyte model. DHA and CLA (10,12) have beneficial effects on lipogenesis and inflammatory, oxidative stress and ER stress gene expression despite increasing triglyceride accumulation, indicating that different FA have varying effects on steatotic hepatocyte
Behavioral and neural activity during magnetic stimulation of Tritonia tetraquetra imply conditional magnetotactic response
No full textA variety of species are known to sense and respond to the geomagnetic field for
navigation. The sea slug Tritonia tetraquetra (a.k.a. Tritonia diomedea) has been shown
to respond to the magnetic field through both behavior and electrophysiological
experiments. However, it remains unclear by which mechanism this sensory information
is integrated into motor commands. Additionally, the purpose for a response to magnetic
stimuli has yet to be determined. While it is hypothesized that the sea slug sometimes
uses a cue-switching mechanism to navigate, ultimately relying on the magnetic field for
orientation, laboratory experiments thus far have failed to demonstrate this behavior. The
experiments here sought to test this cue-switching hypothesis by demonstrating a
response to a local distortion in the geomagnetic field. However, the behavioral response
observed was an increased turning frequency upon loss of an initial attractive odor,
independent of magnetic distortion, which is inconsistent with the hypothesized straight,
geomagnetic-guided crawling. Additionally, in electrophysiological experiments ciliary
motor neurons Pd5 and Pd6, as well as sensory nerve CeN1, failed to demonstrate a
response to rotations of the magnetic field, despite previous evidence that these units are
involved in T. tetraquetra’s magnetic response. These results, when compared with
previously demonstrated responses, may imply conditional parameters under which
detection and use of the magnetic field are employed, or may be due to population
differences
Regulation and Endogenous Activators of the Cell-Intrinsic Antiviral Response
No full textThesis (Ph.D.)--University of Washington, 2014The primary objective of immune sensors is to differentiate self from non-self. Detection of viral genomes leads to activation of the antiviral response, accompanied by the production of type I interferons. However, these viral nucleic acids are very similar to host produced RNA and DNA. We investigate how human variants in SKIV2L, an RNA metabolism enzyme, can lead to erroneous interferon production by allowing an accumulation of self-RNA. While studying sources of the endogenous ligands that can accumulate, we considered the role of RNase L in the antiviral response. While the OAS/2-5A system and RNase L have been studied for many years, our findings suggest a new model for their function. We reveal that RNase L acts as a negative regulator of the antiviral response by eliciting global translational inhibition through cleavage of ribosomal RNA. We go on to show that the different 2-5A species synthesized by OAS proteins are endogenous immunostimulatory ligands, and that the OAS/2-5A system generates ligands for crosstalk between the RNA and DNA sensing and signaling networks within every cell. These studies have far-reaching implications for the detection of endogenous RNA ligands, their metabolism, and their association with autoimmune disorders. Furthermore, the reappraisal of RNase L and the new role for 2-5A species as endogenous activators of the antiviral response come with their own clinical implications, and allow for a more complete understanding of the early cellular response to viral pathogens
Antibacterial effectors of the type VI secretion system
No full textThesis (Ph.D.)--University of Washington, 2014With the advent of high-throughput culture-independent sequencing it has become increasingly apparent that bacteria often live in complex communities, both in the environment and in association with the human body. Moreover, in polymicrobial settings there is often fierce competition for both space and resources, the results of which can have drastic effects on community composition. The evolutionary pressure exerted by competition is reflected by the significant portion of the coding capacity of many bacterial genomes dedicated to the production and regulation of antagonistic pathways. One such pathway, the type VI secretion system (T6SS), has emerged as a mechanism mediating the delivery of potent antibacterial effectors between contacting Gram-negative bacteria, granting the attacking organism a fitness benefit over sensitive neighbors. Initial studies of interbacterial T6S provided evidence that this system plays an important role in antagonism, however its mechanism of action on recipient cells remained elusive. This thesis describes the first biochemical characterization of antibacterial T6SS effector proteins, finding that they compromise basal features of bacterial physiology such as cell envelope integrity. By targeting highly conserved processes the T6SS has the capacity to mediate antagonism between highly disparate organisms. The cost of such versatility is that bacteria are susceptible to their own T6SS effectors. In order to overcome this hurdle antibacterial effectors are invariably associated with cognate immunity proteins that prevent their toxicity, protecting the producing cell. Beyond initial biochemical characterization of antibacterial effector proteins, this work describes informatic efforts to identify substrates secreted by the interbacterial T6SS throughout sequenced bacterial genomes. This strategy uncovered highly divergent effector sequences comprising distinct families within superfamilies defined by a common enzymatic target. These divergent effectors not only exhibit distinct substrate specificities, but also vary in their capacity to be neutralized by different sets of immunity proteins. Lastly, our informatic efforts led to the discovery of antibacterial effector proteins in a phylum of Gram-negative bacteria not predicted to encode a T6SS, the Bacteroidetes. My work on this abundant environmental and human-associated phylum of bacteria has found that they possess a highly divergent T6S-like pathway, one that, like its Proteobacterial homolog, takes part in interbacterial antagonism. Together, these findings represent a significant advancement in the field of interbacterial T6S, and serve as a platform for further work defining the in situ benefit of this antagonistic pathway
Rotating Torsion Balance Tests of the Weak Equivalence Principle
No full textThesis (Ph.D.)--University of Washington, 2014We used a rotating torsion balance to make the most precise laboratory search for equivalence-principle violation. We used a beryllium-aluminum composition dipole to complement our previous measurement with a beryllium-titanium composition dipole. We improved the tilt stability of the apparatus and reduced the temperature gradient feed-through to improve the uncertainty by 30% compared to our beryllium-titanium result. Using the beryllium-aluminum test bodies, we found . The combined limits using both test bodies pairs generally limit any new equivalence-principle-violating force that couples to ordinary neutral matter. We also measured test-bodies with compositions that mimic the difference in composition between the earth and moon to provide a model-independent weak equivalence principle limit of for comparison with lunar laser ranging strong equivalence principle measurements. The combined lunar laser ranging and weak equivalence principle measurements limit equivalence-principle violation for gravitational binding energy to at 1-
The Effects of Perceived Body Weight on Dieting Behaviors and Physical Activity in Overweight and Obese American Indian and Alaska Native Adolescents
No full textThesis (Master's)--University of Washington, 2014Background: Self-perception of body weight is an important issue among adolescents, a group at risk for body dissatisfaction and negative diet-related behaviors related to weight perception. The aim of our study was to evaluate weight perception among American Indian and Alaska Native (AI/AN) overweight and obese adolescents and examine the associations between the accuracy of perceived body weight and dieting and physical activity behaviors. Methods: Using American Indian Alaska Native data from the national Youth Risk Behavior Surveillance System (2007-2011), we performed a cross sectional analysis of weight perception and dieting and physical activity among overweight and obese youth. Respondents' self-described weight status was matched with their body mass index (BMI) percentile using self-reported weight and height. Youth were classified as accurate perceivers if self-perception and BMI percentile coincided or misperceivers if the two were discordant. We evaluated the association between accurate perception versus misperception of weight and diet and physical activity outcomes using logistic regression to estimate prevalence odds ratios (aPOR) and 95% confidence intervals (CI), adjusting for sex. Results: Misperceivers were more likely to be male and 15-16 years old than accurate perceivers. Misperceivers were 80 % (95% CI: 0.13-0.31) less likely to be trying to lose weight and 36% (95% CI: 0.40-1.03) less likely to be fasting to lose weight than accurate perceivers. Misperceivers were 48% (95% CI: 1.00-2.17) more likely to engage in ≥60 minutes of physical activity on ≥5 days per week 69% (95% CI: 1.15-2.48) more likely to attend physical education classes ≥3 days per week, and 95% (95% CI: 1.34-2.85) more likely to have played on ≥1 sports teams during the previous year than accurate perceivers. Misperceivers were also 64% (95% CI: 1.11-2.43) more likely to consume the recommended daily servings of fruit than accurate perceivers. Conclusion: The finding that misperceivers were more likely than accurate perceivers to engage in physical activity and less likely to engage in unhealthy fasting behavior suggests that adolescents' self-perceived weight status should be considered when designing weight-related interventions in this population and warrants further investigation in future studies
The Bittersweet Taste of the Past: Reading Food in Armenian Literature in Turkish
No full textThesis (Ph.D.)--University of Washington, 2014This dissertation investigates Armenian literature in Turkish through the two authors Takuhi Tovmasyan and Migirdic Margosyan by analyzing their literary works with an emphasis on food. By putting the traumatic experiences and the memories of 1915 in the cultural contexts of daily lives such as through music, food, and art, Armenians in Turkey found alternative ways to speak about their silenced past and create spaces in which to be heard. These spaces in Tovmasyan and Margosyan's case are the kitchen, the table and the market place. Reading food in literary works written by Tovmasyan and Margosyan enables us to understand and articulate the Armenian experience in Turkey since the 1990s. Food might be considered one of the "safest" topics to talk about the "other", especially when the other is integrated into the dominant culture and safely visible to the dominant gaze by stripping off its traumatic past. However, food items with their sensual properties trigger the memories of the past through smell, taste and hearing and they become important tools to remember and reconstruct the past in present conditions. This dissertation tries to answer questions such as: when a group of people continuously endure erasure and become voiceless in the face of mainstream culture, how does this group speak back in order to become visible? What are the cultural and literary tools that an ethnic community uses to reconcile with the past and get recognition in the mainstream culture? In order to find an answer to these questions, Margosyan and Tovmasyan's self narratives which are written in different literary genres are investigated. This dissertation project suggests developing an interdisciplinary approach to literature and food studies in contemporary Armenian literature in Turkish. In short, by analyzing the representation of their daily lives and its relation to the past through food performances I show how Margosyan and Tovmasyan speak back to the dominant culture in Turkey