Assessing Responses of \u3ci\u3eBetula papyrifera\u3c/i\u3e (Paper Birch) to Climate Variability in a Remnant Population Along the Niobrara River in Nebraska Through Dendroecological and Remote Sensing Techniques

Remnant populations of the boreal species Betula papyrifera, found along north-facing canyons and river banks of the Niobrara River Valley in north-central Nebraska, represent one of the southernmost distributions of the species in North America. Although, the species has persisted in the Great Plains after the Wisconsin Glaciation due to the local topography and microclimatic conditions, canopy dieback has been reported in recent years, which is believed to be attributed to temperature change. Therefore, the goals of this research are to: 1) use dendroecological techniques, or the study of tree rings to assess the responses B. papyrifera to intra- and inter-annual micro-environmental variability between 1950 and 2014, and identify the abiotic factor(s) which best describe the observed growth trends in this species; and 2) determine whether the use of satellite imagery from Landsat 5 TM (1985-2011) and MODIS (2000-2014) can serve as a proxy for assessing tree health by relating indices like the Normalized Difference Vegetation Index (NDVI) to tree rings characteristics. Results showed that growing-season streamflow and precipitation were positively and significantly correlated with raw tree ring widths, basal area increment increase, and standardized ring widths (p \u3c 0.05), while high late fall and spring precipitation and streamflow seemed to have a negative effects. The strongest predictor for standardized tree ring growth was the Palmer’s Drought Severity Index (PDSI), suggesting that B. papyrifera is highly responsive to a combination of temperature and water availability. GLMMs and Pearson R2 correlations indicated that increasing winter and spring temperatures were unfavorable for tree growth while increasing summer temperatures were favorable in the absence of drought. Maximum and accumumlated NDVI derived from satellite imagery showed potential of these techniques to be used as a proxy for ex-situ monitoring B. papyrifera performance through high Pearson’s R2 values (≥0.76) at the pixel level. Landsat 5 TM derived max-value NDVI correlations identified adjacent rangeland of moderate bison grazing on rough landscape - similar to those occupied by B. papyrifera – as a likely reliable proxy for predicting seasonal growth and performance the species. Results from this study have significant management implications and are critical to the development of biogeographical and ecophysiological predictive models aimed at forecasting the dynamics and performance of this species in the face of future climate variability, extremes, and change in both remnant populations and across its current habitat range in more northern latitudes. Advisor: Tala Awad

Assessing Responses of \u3ci\u3eBetula papyrifera\u3c/i\u3e to Climate Variability in a Remnant Population along the Niobrara River Valley in Nebraska U.S. through Dendroecological and Remote Sensing Techniques

Remnant populations of Betula papyrifera have persisted in the Great Plains after the Wisconsin Glaciation along the Niobrara River Valley, Nebraska. Population health has declined in recent years, and has been hypothesized to be due to climate change. We used dendrochronological techniques to assess the response of B. papyrifera to microclimate (1950-2014), and satellite imagery [Landsat 5 TM (1985-2011) and MODIS (2000-2014)] derived NDVI as a proxy for population health. Growing-season streamflow and precipitation were positively correlated with raw and standardized tree-ring widths and basal area increment increase. Increasing winter and spring temperatures were unfavorable for tree growth while increasing summer temperatures were favorable in the absence of drought. The strongest predictor for standardized tree-rings was the Palmer Drought Severity Index, suggesting that B. papyrifera is highly responsive to a combination of temperature and water availability. The NDVI from vegetation community was positively correlated with standardized tree-ring growth, indicating the potential of these techniques to be used as a proxy for ex-situ monitoring of B. papyrifera. These results aid in forecasting the dynamics of the species in the face of climate variability and change in both remnant populations and across its current distribution in northern latitudes of North America

Assessing Responses of \u3ci\u3eBetula papyrifera\u3c/i\u3e (Paper Birch) to Climate Variability in a Remnant Population Along the Niobrara River in Nebraska Through Dendroecological and Remote Sensing Techniques

Remnant populations of the boreal species Betula papyrifera, found along north-facing canyons and river banks of the Niobrara River Valley in north-central Nebraska, represent one of the southernmost distributions of the species in North America. Although, the species has persisted in the Great Plains after the Wisconsin Glaciation due to the local topography and microclimatic conditions, canopy dieback has been reported in recent years, which is believed to be attributed to temperature change. Therefore, the goals of this research are to: 1) use dendroecological techniques, or the study of tree rings to assess the responses B. papyrifera to intra- and inter-annual micro-environmental variability between 1950 and 2014, and identify the abiotic factor(s) which best describe the observed growth trends in this species; and 2) determine whether the use of satellite imagery from Landsat 5 TM (1985-2011) and MODIS (2000-2014) can serve as a proxy for assessing tree health by relating indices like the Normalized Difference Vegetation Index (NDVI) to tree rings characteristics. Results showed that growing-season streamflow and precipitation were positively and significantly correlated with raw tree ring widths, basal area increment increase, and standardized ring widths (p \u3c 0.05), while high late fall and spring precipitation and streamflow seemed to have a negative effects. The strongest predictor for standardized tree ring growth was the Palmer’s Drought Severity Index (PDSI), suggesting that B. papyrifera is highly responsive to a combination of temperature and water availability. GLMMs and Pearson R2 correlations indicated that increasing winter and spring temperatures were unfavorable for tree growth while increasing summer temperatures were favorable in the absence of drought. Maximum and accumumlated NDVI derived from satellite imagery showed potential of these techniques to be used as a proxy for ex-situ monitoring B. papyrifera performance through high Pearson’s R2 values (≥0.76) at the pixel level. Landsat 5 TM derived max-value NDVI correlations identified adjacent rangeland of moderate bison grazing on rough landscape - similar to those occupied by B. papyrifera – as a likely reliable proxy for predicting seasonal growth and performance the species. Results from this study have significant management implications and are critical to the development of biogeographical and ecophysiological predictive models aimed at forecasting the dynamics and performance of this species in the face of future climate variability, extremes, and change in both remnant populations and across its current habitat range in more northern latitudes. Advisor: Tala Awad

Proprietary research to determine feasibility of commercializing the Pink Oyster Mushroom

This project serves as a feasibility experiment to bring the Pink Oyster mushroom(Pleurotus flabellatus) into constant domestic cultivation for the purposes of commercialization. Important data acquired from growth trials were growth timelines and yields. This information was used to generate interactive spreadsheets with which one can determine possible cost and profit in a variety of scenarios. The first portion of the experiment involved constructing a growth chamber, which can achieve and maintain stable environmental conditions. This portion was successful. Secondly, the numbers obtained from the experimental growth trials were used to determine future projections from the perspective of a small business start up. According to the data, investment in production is expected to be highly lucrative, with a projected net profit margin range of 300-2000

Assessing Responses of \u3ci\u3eBetula papyrifera\u3c/i\u3e to Climate Variability in a Remnant Population along the Niobrara River Valley in Nebraska U.S. through Dendroecological and Remote Sensing Techniques

Remnant populations of Betula papyrifera have persisted in the Great Plains after the Wisconsin Glaciation along the Niobrara River Valley, Nebraska. Population health has declined in recent years, and has been hypothesized to be due to climate change. We used dendrochronological techniques to assess the response of B. papyrifera to microclimate (1950-2014), and satellite imagery [Landsat 5 TM (1985-2011) and MODIS (2000-2014)] derived NDVI as a proxy for population health. Growing-season streamflow and precipitation were positively correlated with raw and standardized tree-ring widths and basal area increment increase. Increasing winter and spring temperatures were unfavorable for tree growth while increasing summer temperatures were favorable in the absence of drought. The strongest predictor for standardized tree-rings was the Palmer Drought Severity Index, suggesting that B. papyrifera is highly responsive to a combination of temperature and water availability. The NDVI from vegetation community was positively correlated with standardized tree-ring growth, indicating the potential of these techniques to be used as a proxy for ex-situ monitoring of B. papyrifera. These results aid in forecasting the dynamics of the species in the face of climate variability and change in both remnant populations and across its current distribution in northern latitudes of North America

Assessing Responses of Betula papyrifera to Climate Variability in a Remnant Population along the Niobrara River Valley in Nebraska through Dendroecological and Remote Sensing Techniques

Remnant populations of Betula papyrifera have persisted in the Great Plains after the Wisconsin Glaciation along the Niobrara River Valley, Nebraska. Population health has declined in recent years, and has been hypothesized to be due to climate change. We used dendrochronological techniques to assess the response of B. papyrifera to microclimate (1950-2014), and satellite imagery [Landsat 5 TM (1985-2011) and MODIS (2000-2014)] derived NDVI as a proxy for population health. Growing-season streamflow and precipitation were positively correlated with raw and standardized tree-ring widths and basal area increment increase. Increasing winter and spring temperatures were unfavorable for tree growth while increasing summer temperatures were favorable in the absence of drought. The strongest predictor for standardized tree-rings was the Palmer Drought Severity Index, suggesting that B. papyrifera is highly responsive to a combination of temperature and water availability. The NDVI from vegetation community was positively correlated with standardized tree-ring growth, indicating the potential of these techniques to be used as a proxy for ex-situ monitoring of B. papyrifera. These results can aid in forecasting the dynamics of this species in the face of climate variability and change in both remnant populations and across its current distribution in northern latitudes of North America.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Human polymeric IgA is superior to IgG and single-chain Fv of the same monoclonal specificity to inhibit urease activity associated with Helicobacter pylori.

Helicobacter-induced gastritis is considered nowadays an epidemic, the prevalence of which is one of the highest world-wide (70%), with as much as 40% of the population in industrialized countries. Helicobacter pylori (H. pylori) antigens (Ag) capable to elicit a protective immune response in animal models have been identified, but these antigens have not been shown to be strongly immunogenic when administered to humans. Due to their stability in the gastric environment and avidity, passive administration of secretory immunoglobulin A (SIgA) antibodies (Ab) targeting protective Ag might be particularly relevant as a substitute or complement to current therapies. To this aim, we have designed expression vectors to convert a scFv polypeptide specific for H. pylori urease subunit A into human IgG, polymeric IgA (IgAp/d) and SIgA. Purified proteins show proper binding characteristics toward both the native and denatured forms of H. pylori urease. The direct comparison between different isotype and molecular forms, but of unique specificity, demonstrates that SIgA and IgAp/d are more efficient in blocking free and H. pylori-associated urease than IgG and scFv. We conclude that the expression system reported herein will represent a valuable tool to produce human SIgA Ab of multiple specificities against H. pylori antigens involved in colonization and persistence

Data from: Nutrient distribution and absorption in the colonial hydroid Podocoryna carnea is sequentially diffusive and directional

The distribution and absorption of ingested protein was characterized within a colony of Podocoryna carnea when a single polyp was fed. Observations were conducted at multiple spatial and temporal scales at three different stages of colony ontogeny with an artificial food item containing Texas Red conjugated albumin. Food pellets were digested and all tracer absorbed by digestive cells within the first 2–3 hours post-feeding. The preponderance of the label was located in the fed polyp and in a transport-induced diffusion pattern surrounding the fed polyp. After 6 hours post-feeding particulates re-appeared in the gastrovascular system and their absorption increased the area over which the nutrients were distributed, albeit still in a pattern that was centered on the fed polyp. At later intervals, tracer became concentrated in some stolon tips, but not in others, despite the proximity of these stolons either to the fed polyp or to adjacent stolons receiving nutrients. Distribution and absorption of nutrients is sequentially diffusive and directional

Clonal analysis of Salmonella-specific effector T cells reveals serovar-specific and cross-reactive T cell responses

To tackle the complexity of cross-reactive and pathogen-specific T cell responses against related Salmonella serovars, we used mass cytometry, unbiased single-cell cloning, live fluorescence barcoding, and T cell–receptor sequencing to reconstruct the Salmonella-specific repertoire of circulating effector CD4+ T cells, isolated from volunteers challenged with Salmonella enterica serovar Typhi (S. Typhi) or Salmonella Paratyphi A (S. Paratyphi). We describe the expansion of cross-reactive responses against distantly related Salmonella serovars and of clonotypes recognizing immunodominant antigens uniquely expressed by S. Typhi or S. Paratyphi A. In addition, single–amino acid variations in two immunodominant proteins, CdtB and PhoN, lead to the accumulation of T cells that do not cross-react against the different serovars, thus demonstrating how minor sequence variations in a complex microorganism shape the pathogen-specific T cell repertoire. Our results identify immune-dominant, serovar-specific, and cross-reactive T cell antigens, which should aid in the design of T cell–vaccination strategies against Salmonella