Does Context Matter for the Relationship between Deprivation and All-Cause Mortality? The West vs. the Rest of Scotland

Background A growing body of research emphasizes the importance of contextual factors on health outcomes. Using postcode data for Scotland (UK), this study tests the hypothesis of spatial heterogeneity in the relationship between area-level deprivation and mortality to determine if contextual differences in the West vs. the rest of Scotland influence this relationship. Research into health inequalities frequently fails to recognise spatial heterogeneity in the deprivation-health relationship, assuming that global relationships apply uniformly across geographical areas. In this study, exploratory spatial data analysis methods are used to assess local patterns in deprivation and mortality. Spatial regression models are then implemented to examine the relationship between deprivation and mortality more formally. Results The initial exploratory spatial data analysis reveals concentrations of high SMR and deprivation values (hotspots) in the West of Scotland and concentrations of low values (coldspots) for both variables in the rest of the country. The main spatial regression result is that deprivation is the only variable that is highly significantly correlated with all-cause mortality in all models. However, in contrast to the expected spatial heterogeneity in the deprivation-mortality relationship, this relation does not vary between regions in any of the models. This result is robust to a number of specifications, including weighing for population size, controlling for spatial autocorrelation and heteroskedasticity, assuming a non-linear relationship between mortality and deprivation, breaking the dependent variable into male and female SMRs, and distinguishing between West, North and Southeast regions. The rejection of the hypothesis of spatial heterogeneity in the relationship between deprivation and mortality complements prior research on the stability of the deprivation-mortality relationship over time. Conclusions The obtained homogeneity in the deprivation-mortality relationship across the regions of Scotland and the absence of a contextualized effect of region highlights the importance of taking a broader strategic policy that can combat the toxic impacts of deprivation on health. Focusing on a few specific places (e.g. 15% of the poorest areas) to concentrate resources might be a good start but the impacts of deprivation on mortality is not restricted to a few places. A comprehensive strategy that can be sustained over time might be needed to interrupt the linkages between poverty and mortality.

Analysis Of Micromixers To Minimize Scaling Effects On Reverse Osmosis Membranes

ABSTRACT ANALYSIS OF MICROMIXERS TO MINIMIZE SCALING EFFECTS ON REVERSE OSMOSIS MEMBRANES by Jeremy Walker December 2018 Advisor: Dr. Shawn McElmurry Major: Civil Engineering Degree: Doctor of Philosophy Structural elements, typically mesh spacers, are required between membrane leaves in spiral wound elements to ensure flow through reverse osmosis (RO) modules. The standard diamond-shaped mesh spacer results in non-ideal hydrodynamics that can lead to fouling, which ultimately reduces the flux of water through the membrane and the operational life of the unit. Additionally, traditional mesh feed spacers do not allow for reverse flow cleaning due to obstructed flow paths and, once fouled, the entrapment of scale. To address this shortcoming, a novel method for separating RO membrane leaves in spiral wound elements is developed and evaluated. Three-dimensional (3-D) printing was utilized to manufacture micromixers directly on membrane swatches. To enhance performance, a two-dimensional computational fluid dynamic model was used to select the optimal geometry and pattern of 3-D printed micromixers. The optimal geometry selected created unhindered flow between 0.2 m/s and 0.3m/s, using an inlet flow velocity of 0.104 m/s, across 40% of the membrane surface. Laboratory experiments were conducted to evaluate the performance of micromixers and compared to unmodified membranes with a standard 20 mil (0.508 mm) mesh feed spacer. Pure water flux and salt rejection were found to be similar to standard membranes, indicating the 3-D printing process did not damage intrinsic membrane properties. Calcium sulfate scaling experiments were conducted. Scale initially began to form within 2 hours of treatment resulting in a flux decline of approximately 10% for both modified and unmodified membranes. Over 14 hours, an average flux decrease of 24% was observed for modified membranes compared to an average flux decrease of 78% for the unmodified membranes. This demonstrated the improved resistance to fouling created by the open channel design with optimal flow conditions. Based on the open-channel flow paths created using 3-D printed micromixers, improved scale removal by reverse flow cleaning procedures was evaluated. The modified membranes showed 5-10% more removal for calcium sulfate compared to the unmodified membrane utilizing a 20 mil (0.508 mm) mesh feed spacer. Following cleaning, all three unmodified membranes and feed spacers had significant remaining scale, while all three modified membranes showed minimal scale. Micromixers printed directly to the membrane surface offers the ability to optimize feed channel hydrodynamics, reduce scale formation, minimize flux decline, and allow for reverse flow cleaning of fouled membranes, representing a significant advancement in membrane technology

The Effects of a Season-Long Relaxation Program on Anxiety and Performance in Female High School Track & Field Throwers

The purpose of this study was to examine the effects of a season-long relaxation breathing program on anxiety and performance in track and field throwers. It was hypothesized that the relaxation breathing technique would help to reduce anxiety and increase overall performance. Use of a single-subject research design was used to allow ongoing monitoring of each athlete’s anxiety levels and performance. Results indicated that 2 of the 3 participants had improved performance and reduced trait anxiety over the course of the season. Additional results indicated that there was no significant difference in performance between participants and non-participants and that the changes in anxiety were not statistically significant. Suggestions for future research include increasing the sample size and using an outside administrator to conduct the study

Does Context Matter for the Relationship between Deprivation and All-Cause Mortality? The West vs. the Rest of Scotland

One of the assumptions that is often made in modeling the relationship between deprivation and mortality is that this relationship will remain the same across space. There is little justification presented in the literature as to why the deprivation-mortality relationship will be homogenous across space. The homogeneity of this relationship over space is an empirical question and most of the published literature does not formally test this relationship. Using postcode data for Scotland (UK), this study addresses this research gap and tests the hypothesis of spatial heterogeneity in the relationship between area-level deprivation and mortality. Research into health inequalities frequently fails to recognise spatial heterogeneity in the deprivation-health relationship, assuming that global relationships apply uniformly across geographical areas. In this study, exploratory spatial data analysis methods are used to assess local patterns in deprivation and mortality. A variety of spatial regression models are then implemented to examine the relationship between deprivation and mortality. The hypothesis of spatial heterogeneity in the relationship between deprivation and mortality is rejected. Implications of the homogeneity of the deprivation-mortality relationships for addressing health inequities are discussed in light of the inverse care law.

The ecology of constructed ponds on the lower Waikato River floodplain: implications for waterfowl management

Numerous ponds have been constructed in recent years on the lower Waikato River floodplain yet many waterfowl populations are in decline. Overseas research highlights the importance of constructed ponds for waterfowl populations; however, no comprehensive research has been carried out in New Zealand. The overarching aim of this research was to investigate how the ecology of constructed ponds on the lower Waikato River floodplain influences waterfowl densities, community composition and juvenile productivity. The study involved 34 constructed ponds which were predominantly found around Lakes Waikare and Whangape, and the internationally significant Whangamarino wetland. Data were collected on the physicochemical, landscape and vegetation characteristics of the ponds, as well as macroinvertebrate and fish assemblages to determine relationships between and within abiotic and biotic pond factors. Waterfowl communities were observed four times between September and December 2013 to determine mean densities of waterfowl per hectare and the mean community composition of each pond. The waterfowl data were used to explore key relationships with abiotic and biotic factors. Site hydrology was found to have a significant influence on macroinvertebrate and fish community composition. The relative abundance of macroinvertebrates was predominantly lower in degraded ponds which were characterised by water supplied by swamps that frequently flood. Benthic macroinvertebrate abundance was lower in temporary ponds, indicating pond permanence was important. Fish communities of frequently flooded ponds were characteristic of pest fish as a result of increased connectivity. Ponds with high pest fish biomass, especially koi carp (Cyprinus carpio), tended to be more turbid with relatively low macroinvertebrate abundance. The percentage of pond margin fenced had consistently high explanatory power for differences in community composition of macroinvertebrate and fish communities. Food availability and physical pond characteristics were important for waterfowl. Higher waterfowl abundances were found on ponds with high food availability, larger areas, and high pond complexity. Waterfowl densities were higher on ponds with lower fish biomass which is likely a result of decreased competition for macroinvertebrates as food. The suitability of a pond for waterfowl appeared to be species-specific. Broods were often encountered on ponds with large areas, high complexities, and increased marginal fencing. This study has allowed for the development of a conceptual model of the relationships between pond attributes and waterfowl communities. The findings of this study indicate habitat heterogeneity at the landscape scale is important for waterfowl. Providing a network of heterogeneous ponds across the landscape will provide enough varied habitat to support diverse and abundant waterfowl communities, and should include ponds of varying sizes, shapes, depths, vegetation and hydrology. It is also important to construct permanent ponds with limited flood frequency. Excluding pest fish and livestock from ponds will likely increase waterfowl use, and brood occupancy, of ponds as a result of improved water quality and reduced competition for food with fish

Segmented waveguides in thin silicon-on-insulator

We have developed new silicon-on-insulator waveguide designs for simultaneously achieving both low-loss optical confinement and electrical contacts, and we present a design methodology based on calculating the Bloch modes of such segmented waveguides. With this formalism, waveguides are designed in a single thin layer of silicon-on-insulator to achieve both optical confinement and minimal insertion loss. Waveguides were also fabricated and tested, and the measured data were found to closely agree with theoretical predictions, demonstrating input insertion loss and propagation loss better than 0.1 dB and -16 dB/cm, respectively