Preparing for the Onset of Hemlock Mortality in Great Smoky Mountains National Park: An Assessment of Potential Impacts to Riparian Ecosystems

Currently the Hemlock Woolly Adelgid (Adelges tsuga) is spreading across forests in eastern North America, causing the decline and mortality of the eastern hemlock and the Carolina hemlock. Investigation into the impact of hemlock mortality on ecosystem processes has only recently begun and is not yet fully understood. The loss of hemlock from riparian forests in Great Smoky Mountains National Park (GSMNP) could reasonably be expected to result in significant alterations to stream environments. The goal of this study was to assess the influence of riparian hemlock stands on stream conditions and estimate possible impacts from hemlock loss in GSMNP. I paired hardwood- and hemlock-dominated streams that were similar in topography, geology, land use, and disturbance history using Geographic Information Systems (GIS) analysis and statistical techniques. I then monitored each stream pair for water temperature, nitrate concentrations, pH, and discharge over eleven months. I found that differences between hemlock- and hardwood-dominated streams could not be explained by dominant forest type alone; the presence of hemlock or hardwood riparian forest does not appear to exert a consistently dominant signal on measured conditions of headwater streams in GSMNP. The variability in the results suggests that other landscape variables, such as the influence of understory Rhododendron species, may exert more control on stream conditions than differences between hemlock and hardwood canopies. For example, Rhododendron was found to reduce light levels reaching the forest floor and streambeds in both hemlock- and hardwood- dominated forest stands. Evidence from recent peer-reviewed literature suggests that short-term stream condition impacts from forest disturbances can be severe. However, research also indicates that conditions can return to pre-disturbance levels within five to ten years. In GSMNP, the return to long-term stability of stream conditions after hemlock mortality will depend on the type of replacement species and how quickly the replacement species can establish in disturbed sites. There is evidence that deciduous hardwood species are most likely to replace hemlock. The results of this study suggest that hemlock and hardwood stream conditions are similar in GSMNP. Therefore, if hardwood species are able to replace hemlock in GSMNP and streams are able to recover from short term impacts, the long term impacts from hemlock mortality on stream conditions will be minimal. However, the presence of Rhododendron in riparian hemlock forests in GSMNP may prevent hardwood species from effectively replacing hemlock, which could hinder the return to long-term stability

Complexive Ordering of Reading Experience Through Grapheme-Phoneme Relative Frequency Control

This dissertation develops a word bank based on a series of well defined filters. The basis of this system is grapheme-phoneme relative frequency control. The word bank is designed to be used in developing reading materials at varied degrees of difficulty. Four short stories were edited as to their grapheme-phoneme relationships. Reading speed and reading comprehension were measured for each student on these stories. All students read a story in the original form and a story in the filtered version. No difference in reading comprehension were found, but reading speed was significantly higher on three of four stories

Utilization of Phoneme-Grapheme Relative Frequency Data as an Effective Method of Developing Reading Materials for Navajo Students

This thesis suggests a new method of developing reading materials for Navajo students. The core of this method is based on phoneme- grapheme relative frequency correspondence data. A short story was phonetically edited and rewritten using the phoneme-grapheme relative frequency method. This short story was one of the major products of the thesis. This short story and three other short stories previously phonically rewritten, were presented in both this form and in original text to 38 Navajo students for reading. Reading speed and reading comprehension were measured for each student on the short stories. The students performed with superior reading speed and with superior reading comprehension on two stories and equal comprehension on two stories. The difference on reading speed was significant at the .01 level. On the two stories with reading comprehension differences, the difference was significant at the .05 level

Recent trends in the climate of Namaqualand, a megadiverse arid region of South Africa

Abstract Namaqualand is especially vulnerable to future climate change impacts. Using a high-resolution (0.5°x0.5°) gridded data set (CRU TS 3.1) and individual weather station data, we demonstrated that temperatures as well as frequency of hot extremes have increased across this region. Specifically, minimum temperatures have increased by 1.4 °C and maximum temperatures by 1.1 °C over the last century. Of the five weather stations analysed, two showed evidence of a significant increase in the duration of warm spells of up to 5 days per decade and a reduction in the number of cool days (TX10P) by up to 3 days per decade. In terms of rainfall, we found no clear evidence for a significant change in annual totals or the frequency or intensity of rainfall events. Seasonal trends in rainfall did, however, demonstrate some spatial variability across the region. Spatial trends in evapotranspiration obtained from the 8-day MOD16 ET product were characterised by a steepening inland-coastal gradient where areas along the coastline showed a significant increase in evapotranspiration of up to 30 mm per decade, most notably in spring and summer. The increase in temperature linked with the increases in evapotranspiration pose significant challenges for water availability in the region, but further research into changes in coastal fog is required in order for a more reliable assessment to be made. Overall, the results presented in this study provide evidence-based information for the management of climate change impacts as well as the development of appropriate adaptation responses at a local scale

Superintendent Transitioning: When is the Right Time to Make a Move?

Leadership preparation programs prepare superintendents every year to enter the profession. One aspect that needs to be incorporated into this learning is the understanding of when it\u27s the right time to leave as many superintendents leave their current position every year for one reason or another. These reasons can range from being fired to career advancements to leaving the profession. Leaving at the right time is crucial for your career and the district. Lashway (2002) posited that almost a quarter of the superintendents serve less than three years, there are many superintendents leaving positions

Sensitivity of Vertebrate Embryos to Heavy Metals as a Criterion of Water Quality, Phase II: Bioassay Procedures Using Developmental Stages as Test Organisms

Chick, amphibian, and fish embryos were evaluated as bioassay and bioindicator organisms. Test procedures were developed by which embryonic stages may be used 1) in bioassay systems to evaluate the toxicity of particular metallic or metal-containing trace contaminants, and 20 as bioindicators to monitor the quality of natural water resources. A bioassay technique was devised in which metallic toxicants were administered to chick embryos by needle tract injection into the yolk sac. This provided more uniform distribution of test metals throughout the yolk mass than can be obtained by conventional yolk sac injection methods, and gave more sensitivity and uniformity of test results. Metals such as arsenic, cadmium, mercury, lead and zinc are easily detectable at a level of 1 ppb. An in vitroculture technique was developed by which embryos of aquatic vertebrates may be maintained for bioassay and bioindicator purposes. Five test species were identified, suitable synthetic culture water was formulated, and culture monitoring procedures were determined. Most toxic metals (e.g., mercury) may be detected at 1ppb or less with the use of more sensitive embryonic species (e.g., trout). Early cleavage stages of the leopard frog (Rana pipiens) proved more sensitive to cadmium than older embryos, similar to results obtained in Phase I with mercury treatment of frog embryos. Early developmental stages, therefore, have proven especially important for use in bioassay and bioindicator systems

Proxy reconstruction of ultraviolet-B irradiance at the Earth’s surface, and its relationship with solar activity and ozone thickness

Solar ultraviolet-B (UV-B) irradiance that reaches the Earth’s surface acts as a biotic stressor and has the potential to modify ecological and environmental functioning. The challenges of reconstructing ultraviolent (UV) irradiance prior to the satellite era mean that there is uncertainty over long-term surface UV-B patterns, especially in relation to variations in solar activity over centennial and millennial timescales. Here, we reconstruct surface UV-B irradiance over the last 650 years using a novel UV-B proxy based on the chemical signature of pollen grains. We demonstrate a statistically significant positive relationship between the abundance of UV-B absorbing compounds in Pinus pollen and modelled solar UV-B irradiance. These results show that trends in surface UV-B follow the overall solar activity pattern over centennial timescales, and that variations in solar output are the dominant control on surface level UV-B flux, rather than solar modulated changes in ozone thickness. The Pinus biochemical response demonstrated here confirms the potential for solar activity driven surface UV-B variations to impact upon terrestrial biotas and environments over long timescales

Characterization of electrospun nanocomposite scaffolds and biocompatibility with adipose-derived human mesenchymal stem cells

Electrospun nanocomposite scaffolds were fabricated by encapsulating multi-walled carbon nanotubes (MWNT) in poly (lactic acid) (PLA) nanofibers. Scanning electron microscopy (SEM) confirmed the fabrication of nanofibers, and transmission electron microscopy identified the alignment and dispersion of MWNT along the axis of the fibers. Tensile testing showed an increase in the tensile modulus for a MWNT loading of 0.25 wt% compared with electrospun nanofibrous mats without MWNT reinforcement. Conductivity measurements indicated that the confined geometry of the fibrous system requires only minute doping to obtain significant enhancements at 0.32 wt%. Adipose-derived human mesenchymal stem cells (hMSCs) were seeded on electrospun scaffolds containing 1 wt% MWNT and 0 wt% MWNT, to determine the efficacy of the scaffolds for cell growth, and the effect of MWNT on hMSC viability and proliferation over two weeks in culture. Staining for live and dead cells and DNA quantification indicated that the hMSCs were alive and proliferating through day 14. SEM images of hMSCs at 14 days showed morphological differences, with hMSCs on PLA well spread and hMSCs on PLA with 1% MWNT closely packed and longitudinally aligned

The Route to Water Security for Texas: The 2015–2016 Texas Water Roadmap Forums

Three forums were held between February 2015 and November 2016, bringing together Texas water experts from business, industry, government, academia, research, and the investment community in impartially facilitated sessions to deter-mine ways to secure Texas’ water future through accelerating growth of infrastructure, technologies, research, education, and sustainable use. Consensus emerged after the first forum that Texas is approaching a water crisis reflecting matters of supply, allocation, and quality that demands immediate action to ensure water security and equitable access to this vital resource. Participant focus rested on new technology acceleration and investment, workforce education, research underway and desired by segments of the water sector, the water-energy-food nexus, outreach and public education, data management and access, water valuation, water security, and legal and regulatory frameworks. Participants also examined funding and partnership options for development of water treatment and supply infrastructure, water rights and allocation methods, aging infrastructure, and conservation, as well as the nearly ubiquitous fragmenting and compartmentalizing of just about everything having to do with water throughout the entire water sector. The forums generated and summarized a wealth of information that can be used by any party to make progress toward the goal of building a Texas water roadmap. This report summarizes the discussions and the path forward for securing Texas’ water resources

Replication and Meta-Analysis of 13,000 Cases Defines the Risk for Interleukin-23 Receptor and Autophagy-Related 16-Like 1 Variants in Crohn’s Disease

BACKGROUND/OBJECTIVE: Variants in the interleukin-23 receptor (IL23R) and the autophagy-related 16-like 1 (ATG16L1) genes have been associated with an increased risk of Crohn’s disease (CD). Both genes were identified through genome-wide association scans and subsequent studies have validated these associations. To assess the effect size of these variants, an independent case-control association study and meta-analysis were performed. METHODS: British Caucasian subjects with inflammatory bowel disease (n=500) and 877 ethnically matched controls were genotyped for the disease-associated variants in IL23R and ATG16L1. In addition, meta-analyses of 12,991 patients and 14,598 controls, and 11,909 patients and 15,798 controls, were conducted on independently published data for the associations between IL23R and ATG16L1 variants and CD, respectively. RESULTS: In the present cohort, both susceptibility variants showed highly significant associations, including IL23R (rs11209026, P=0.0006; OR 0.37; 95% CI 0.21 to 0.67) and ATG16L1 (rs2241880, P=0.0017; OR 1.36; 95% CI 1.12 to 1.66). The meta-analysis based on the random effects model showed similar combined effects for rs11209026 (n=26, OR 0.41; 95% CI 0.37 to 0.46) and rs2241880 (n=25, OR 1.33; 95% CI 1.28 to 1.39). There was no statistically significant gene-gene interaction between caspase recruitment domain (CARD15) variants and the IL23R or ATG16L1 polymorphisms (P=0.44 and P=0.24, respectively). CONCLUSION: The present cohort and meta-analysis provides strong evidence that, in addition to CARD15, polymorphisms in both IL23R and ATG16L1 alter susceptibility to CD and that these effects are consistent across all populations of European ancestry; however, only ATG16L1 is relevant to inflammatory bowel disease in the Asian population