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Using eDNA to assess the effects of Sierra Nevada meadow restoration on invasive species and sensitive amphibians

Using eDNA to assess the effects of Sierra Nevada meadow restoration on invasive species and sensitive amphibians

Primary author: Nicolette Nelson
Faculty sponsor: Jonah Piovia-Scott

Primary college/unit: Arts and Sciences
Campus: Vancouver

Abstract:

Managers in the Sierra Nevada are increasingly restoring degraded wet meadows in order to recover essential ecosystem services (e.g. water storage and filtration) and to benefit native wildlife. These projects may increase available habitat for federally-listed amphibians, but some projects have unintentionally prompted the spread of invasive species that negatively impact native amphibians through predation, competition, and disease. In order to assess the effects of meadow restoration on invasive species and sensitive amphibians, we used a backpack sampler to collect environmental DNA (eDNA) samples at 23 restored and 23 paired unrestored Sierra Nevada meadows during the summers of 2018 and 2019. Quantitative PCR was used to detect the presence of American bullfrogs (Lithobates catesbeianus), Amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd), and Sierra Nevada yellow-legged frogs (Rana sierrae). R. sierrae were detected at only one site, which may be explained by the relatively low elevation of study sites and the degraded condition of unrestored meadows. Preliminary analysis suggested that L. catesbeianus were associated with pond-and-plug restoration sites, which result in the creation of novel permanent ponds, and Bd was slightly associated with bullfrogs. Our results indicate that wet meadow restoration in the Sierra Nevada may not be directly benefiting sensitive amphibians. Additionally, pond-and-plug restoration may facilitate the spread of some invasive species more than other restoration methods such as beaver dam analogues that aim to mimic natural meadow formation processes.

A Comparative Study of the Memorial Museum of Dominican Resistance and the Museum of Memory and Human Rights (Santiago, Chile)

A Comparative Study of the Memorial Museum of Dominican Resistance and the Museum of Memory and Human Rights (Santiago, Chile)

Primary author: Vilma Navarro-Daniels
Co-author(s): Maria Serenella Previto

Primary college/unit: Arts and Sciences
Campus: Pullman

Abstract:

The Memorial Museum of Dominican Resistance houses a huge collection of documents, pictures, videos, and artifacts related to the resistance against Trujillo. It is visited by hundreds of Dominicans from all over the country as well as schoolers and their teachers. Dominicans do not doubt about the dictatorial nature of Trujillo’s rule (1930-1961). Although in Chile there is a Museum of Memory and Human Rights, Chilean people do not share a common memory about the Pinochet Era (1973-1990). My research focuses on the role and impact that the aforementioned museums and the way they were implemented, promoted, advertised, and interpreted from hegemonic centers of political power may have had on nowadays Chilean historical denial of the political genocide that took place under Augusto Pinochet’s dictatorship in opposition to the well consolidated and shared memory about the atrocities committed during the Trujillo Era that can be observed in Dominican Republic. Thus, my research studies and analyzes these museums in connection to the politics of memory or – conversely— oblivion, the latter also named Historical Alzheimer, and makes progress in the theoretical understanding of museums as components of urban spaces, which are protected and managed in order to achieve very precise goals: Museums are texts, meaning they are narrations that shape nations (Homi Bhabha) and, by doing so, they create a “usable past” (Henry Steele Commager), which, in turn, will form and set up future citizens as either anchored in a shared past or, on the contrary, detached from their own history.

Defining Microbial Soil Health in the Inland Pacific Northwest

Defining Microbial Soil Health in the Inland Pacific Northwest

Primary author: Katherine Naasko
Co-author(s): Haiying Tao
Faculty sponsor: Dr. Haiying Tao

Primary college/unit: Agricultural, Human and Natural Resource Sciences
Campus: Pullman

Abstract:

Phospholipid fatty acid (PLFA) biomarker identification is commonly included in microbial soil health assessments. PLFAs comprise the bilayer cellular membranes of macro and microorganisms that live within soil. Previous literature has shown that PLFA biomarkers and beta-glucosidase enzyme activity are strongly correlated to SOM stocks and associated biochemical nutrient cycling, focused primarily on the surface 20 cm of soil. Many researchers have reported a significant decrease in PLFAs with increasing soil depth, correlated with less SOM to house microbial activity. In dryland cropping systems of the Palouse, winter wheat (WW) roots grow several feet deep, along with microbial communities naturally drawn to the root also, to take advantage of water and nutrients. The objectives of this study include (i) assess how winter wheat-associated microbial communities identified through PLFA and b-glucosidase activity correlate with soil organic matter stocks to 1 meter deep; and (ii) examine relationships across different dynamic soil factors (i.e. tillage intensity) and inherent properties (i.e., precipitation and temperature) of Palouse silt loam. Agricultural sites had lower PLFA biomass compared to the grass site, however the relationships between carbon stocks and enzyme activities are not as straightforward. All sites had lower indicators deeper in the soil, which positively correlates to relative availability of carbon sources for food and energy. When comparing soils from ag sites along the precipitation and temperature gradient, significant linear correlations were found.

This is supported in part through the ARCS Fellowship and the PNNL-WSU Distinguished Graduate Researcher Program.

Falling and Depression among Older Adults: Explanations, Conditions and Implications

Falling and Depression among Older Adults: Explanations, Conditions and Implications

Primary author: Kyle Murphy
Co-author(s): Shane McFarland; Myah Houghten; Marie Gray; Garrett Jenkins
Faculty sponsor: Brittany Cooper

Primary college/unit: Agricultural, Human and Natural Resource Sciences
Campus: Pullman

Abstract:
Introduction: The present study, presented at the Society for Prevention Research (SPR) 2019 conference as part of the SPR Cup, an academic competition for early-career prevention scientists, is an award-winning study, making WSU the winner of this competition for two consecutive years. With SPR-intentions to broaden prevention science in older adults (a critically understudied population with growing needs), all teams worked with the Medicare Health Outcomes Survey Data, a longitudinal, population-level dataset 1.5 months prior to presenting. Using Anderson’s Behavioral Health Model, the goal of the present study was to assess the relationships of needs-based, enabling and environmental mechanisms/processes by which falling predicts depression in older adults. Experiencing a fall increases risk for depression, which increases risk for suicidality and nursing home admission, and is related to mobility, physical health, physical activity, and health policy.

Sample: N>50,000 adults aged 65+, cohorts 2007-2014.

Method: We employed multiple group structural equation modeling to evaluate the following: 1. Mediation of falling predicting depression through mobility and general physical health; 2. Moderated-mediation by physical activity promotion; 3. Moderated-mediation by implementation of the affordable care act (ACA; designed to enhance Medicare).

Findings/conclusions: Reduced mobility and physical health explained the relationship between falling and increased depression. This relationship was consistent, however, the associative magnitude changed by condition; individuals who reported physical activity promotion with medical professionals, and individuals post-ACA implementation, were at significantly less risk. Implications for older adults, include continued prevention research and medical practices that promote physical activity. Furthermore, ACA evaluation is warranted.

Small RNA-mediated gene regulation on both sides of the wheat stripe rust interaction

Small RNA-mediated gene regulation on both sides of the wheat stripe rust interaction

Primary author: Nicholas Mueth

Primary college/unit: Agricultural, Human and Natural Resource Sciences
Campus: Pullman

Abstract:

Wheat stripe rust is a global disease that burdens farmers with yield loss and increased fungicide expenses. The causative agent, the fungus Puccinia striiformis f. sp. tritici, develops infection structures inside living plant cells, suppressing the defense response in order to steal nutrients for further growth and reproduction. While many fungal virulence-promoting factors are proteins, it was recently discovered that small RNA molecules also function in this manner by silencing complementary host genes. Meanwhile, wheat-derived small RNAs are induced or repressed during infection, yet their targets are mostly unknown. In this work, small RNA, degraded RNA, and gene expression data were combined to investigate post-transcriptional gene regulation on both sides of the host-parasite interaction. Our goal was to identify target transcripts by the observation of high transcript slicing frequency at the precise position of small RNA binding sites. Targets among fungal transcripts indicated native regulation of fungal development; wheat target transcripts indicated cross-kingdom gene silencing. Some wheat targets, but not all, showed reduced expression during infection with stripe rust, suggesting a complex pattern of gene induction and repression. Analysis of wheat microRNA loci revealed novel candidate genes in each of the three wheat subgenomes. Resistant and susceptible wheat varieties showed differential expression of microRNAs involved in the regulation of disease resistance and phosphate uptake. This work highlights the small RNA repertoire of an important plant pathogen, as well as the responses of its host. The newly-identified target genes will provide prospects for the development of pathogen control biotechnology.

A multiplicity of barriers: The self-employment of immigrant Hispanic women in the United States

A multiplicity of barriers: The self-employment of immigrant Hispanic women in the United States

Primary author: Samuel Mindes

Primary college/unit: Arts and Sciences
Campus: Pullman

Abstract:

A range of factors influences the economic opportunities for Hispanic women. These barriers include family construction, such as marital status, children at home, and living arrangements. Economic opportunities also hinge on educational and employment history, the status of the local economy, the composition of the local community, and a range of other individual characteristics. Indeed, these critical barriers overlap and interact with cultural expectations. Chiefly to this is immigration status, which is a crucial backdrop to these barriers due to cultural tensions and family expectations. These barriers are particularly central to shaping involvement in the self-employment sector, which is more contingent on these dynamics than wage work. Furthermore, self-employed business incorporation also hinges on these and other factors. We investigate how personal, familial, and social factors influence self-employment propensity and business incorporation for Hispanic women at the intersection of Hispanic group membership and immigrant status. While incorporation offers essential benefits, such as protection of assets, credibility, access to capital, and tax advantages, it also requires more capital and thus has additional barriers. For Hispanic women, barriers to economic success are numerous. However, self-employment can be both an opportunity to find success or a last-ditch effort to have some source of income. Through statistical modeling of American Community Survey data, we explain the impact of individual and social characteristics on the self-employment of Hispanic women in the United States. Our results find that one’s immigrant generation and Hispanic group is central to shaping the impact of individual, family, and social characteristics.

Genomic Prediction of Quantitative Adult Plant Resistance to Stripe Rust in a Winter Wheat Breeding Program

Genomic Prediction of Quantitative Adult Plant Resistance to Stripe Rust in a Winter Wheat Breeding Program

Primary author: Lance Merrick
Co-author(s): Arron Carter; Xianming Chen; Brian Ward
Faculty sponsor: Arron Carter

Primary college/unit: Agricultural, Human and Natural Resource Sciences
Campus: Pullman

Abstract:

Stripe rust (Puccinia striiformis f. sp. tritici) is one of the most damaging diseases of wheat and has resulted in massive reduction in yield and economic losses globally. Quantitative adult plant resistance (APR) is detected in mature plants, associated with non-specific resistance, and considered to be a durable form of resistance. Quantitative APR is controlled by varying numbers of additive resistance alleles and thus is a good candidate for genomic prediction. The goal of this research was to create a genomic prediction model of quantitative stripe rust resistance for advancing early-generation lines to advanced yield trials in a winter wheat breeding program. We created prediction models using breeding lines from four years (2016-2019) and two breeding populations consisting of doubled-haploid and F5 derived lines. The prediction models used genotype-by-sequencing single-nucleotide polymorphism markers for random effects and KASP markers for known resistance genes for fixed effect covariates. Prediction models used were optimized for training population size, marker density, and statistical model to find the most efficient and accurate method to integrate genomic prediction into a breeding program. Genomic prediction will aid the breeding program for the evaluation and selection of stripe rust resistance in years and environments with limited disease incidence and reduce the need for replicated phenotyping. In doing this, genomic prediction will increase the genetic gain for quantitative stripe rust resistance within wheat breeding populations.

Adaptive evolution in extreme environments

Adaptive evolution in extreme environments

Primary author: Kerry McGowan
Faculty sponsor: Joanna L. Kelley

Primary college/unit: Arts and Sciences
Campus: Pullman

Abstract:

Hydrogen sulfide (H2S) is a lethal gas for most organisms because it inhibits aerobic respiration. However, the fish Poecilia mexicana successfully colonized several springs with high H2S after migrating from nearby freshwater springs. There are known H2S-related changes in gene expression in P. mexicana, but the underlying regulatory changes that control them are unknown. We hypothesized the following: (1)Transcription factors (TFs), which bind to DNA and regulate gene expression, would vary in their expression in P. mexicana based on the presence/absence of H2S. (2)TFs would co-vary with the expression of genes involved in aerobic metabolism and H2S detoxification. We performed network analyses on gene expression data from wild-caught P. mexicana from freshwater and H2S springs and lab-reared individuals exposed to H2S. The network analyses clustered genes into modules based on their expression levels across different treatments, allowing us to draw conclusions regarding the connectivity of these biological networks. Several TFs clustered in one module that significantly correlated with habitat (freshwater versus H2S) in wild-caught P. mexicana. Several aerobic respiration-related genes significantly correlated with different springs, indicating P. mexicana may have evolved different strategies to adapt to H2S. These results indicate that H2S affects the regulation of genes involved in aerobic respiration. As aerobic respiration includes some of the most evolutionarily conserved metabolic pathways in animals, this testifies to the potential of H2S to drive adaptive evolution. Understanding H2S metabolism in these fish will help inform the use of H2S as a therapeutic to treat human conditions.

The Nefarious Sin in Colonial America and Spain

The Nefarious Sin in Colonial America and Spain

Primary author: Francisco Manzo-Robledo

Primary college/unit: Agricultural, Human and Natural Resource Sciences
Campus: Pullman

Abstract:

In this manuscript (500+ pages), a set of colonial documents, obtained from the archives in Spain, dealing with historical events and court proceedings, are analyzed from a literary point of view. A simple model is proposed to bridge the distance from the time the documents were produced, to the present. This is accomplished by considering the existence of a social act—space, a virtual space that contains all acts accepted / not-accepted by society, and the existence of different relative—realities. This project deals with morality and legal proceedings; paleography, transcription and interpretation. The book will be in Spanish.

Dissecting the genetic architecture of Aphanomyces root rot resistance in lentil by QTL mapping and genome-wide association study

Dissecting the genetic architecture of Aphanomyces root rot resistance in lentil by QTL mapping and genome-wide association study

Primary author: Yu Ma
Co-author(s): Afef Marzougui; Clarice Coyne; Sindhuja Sankaran; Dorrie Main; Lyndon Porter; Deus Mugabe; Jamin Smitchger
Faculty sponsor: Dorrie Main

Primary college/unit: Agricultural, Human and Natural Resource Sciences
Campus: Pullman

Abstract:

Lentil (Lens culinaris Medikus) is an important source of protein for people in developing countries. Aphanomyces root rot (ARR) has emerged as one of most devastating diseases affecting lentil production. In this study, we applied two complementary QTL analysis approaches to unravel the genetic architecture underlying this complex trait. A recombinant inbred line (RIL) population and an association mapping population were genotyped using genotyping by sequencing (GBS) to discover novel SNPs. QTL mapping identified 19 QTL associated with ARR resistance, while association mapping detected 38 QTL and highlighted accumulation of favorable haplotypes in most of the resistant accessions. Seven QTL clusters were discovered on six chromosomes and five putative genes involved in plant disease response were detected. Expression analysis revealed four of them, encoding an ABC transporter A family protein, a cytochrome P450 family 71 protein, a chalcone-flavanone isomerase family protein, and pectin esterase, were differentially expressed between resistant and susceptible accessions. This indicates genes involved in secondary metabolism and cell wall modification are potentially associated with ARR. Our findings provide valuable insight into the genetic control of ARR and genetic and genomic resources developed here can be used to accelerate development of lentil cultivars with high levels of partial resistance to ARR.