The Evolution and Development of Awns in the Grass Subfamily Pooideae

This research focuses on a specific example of replicated evolution: the grass awn. Awns are typically extensions of the lemma, but may also appear on glumes or paleas. The lemma is a leaf-like organ on the exterior of the grass flower, the glumes are a pair of bracts subtending the basic unit of grass inflorescences, the spikelet, and the palea is the floral organ opposite the lemma. Awns are often described as hair- or bristle- like, but appear in many different shapes. Many awns are “twisted & geniculate , in which the awn has two sections, a lower twisted column, and an upper straight section (the subule ). These sections are separated by a bend, or knee , which gives rise to the term geniculate . Awns may also be attached, or inserted, to the lemma at different points: either at the tip, apically, or at a point on the back of the lemma, abaxially. Awns are critical for several functions in grasses, and likely contribute to grass dispersal, seedling establishment, and reproductive success. Some awns, like those in barley and wheat, photosynthesize and increase grain weight. Awns are part of a suite of characters that have likely played a key role in the spread of grasses to thrive in almost all terrestrial biomes. I performed a series of experiments aimed at understanding the replicated evolution of awns. I hypothesized that the awned lemma shares homology with the grass leaf, and that conserved leaf genes have been recruited for awn development. To determine the evolutionary history of awns in the Pooideae (the largest grass sub-family), and to select focal species for further study, I performed several ancestral state reconstructions for awn traits in the Pooideae. I discovered that awns have been independently derived at least 30 times in the Pooideae. To test the hypothesis that lemmas and leaves are homologous, I examined the anatomy and micromorphology of several awns from Pooideae species, and found that leaf traits are shared between awns and leaves. Similarly, I examined awn development in three species with independently derived awns and found that they all shared underlying ontogeny with grass leaves. To determine whether the function of straight awns in photosynthesis and contributing to grain weight is conserved in Brachypodium distachyon, I performed an awn removal experiment, and found that awns in B. distachyon do not have a significant role in contributing to grain weight. Finally, I characterized and cloned an awnless mutant in B. distachyon, and showed that a gene with conserved functions in leaf development is responsible for the awnless trait. Further, I find that the ortholog of this gene is also necessary for awn development in Alopecurus myosuroides, a species with independently derived awns. These experiments all support the main hypothesis that lemmas are homologous to leaves, and share the same genetic pathways for development. I find that these instances of replicated evolution are likely supported by developmental constraints, and that heterochrony has a key role in shaping awn development in different species

Beneficial Insects: Mantids

Mantids refer to an entire predatory group of insects in the order Mantodea. The term “mantis” or “praying mantis” actually refers to a particular genus of mantids. Therefore, only some mantids belong to the genus Mantis. There are about 2,000 species of mantids worldwide and at least 20 species in the U.S. Two mantid species dominate Utah gardens: European mantid and Chinese mantid

Beneficial Insects: True Bugs

True bugs have piercing-sucking mouthparts and belong to the order Hemiptera and suborder Heteroptera. There are more than 38,000 species of true bugs, and are most closely related to aphids, cicadas, and leaf hoppers. Although some true bugs are considered pests, about one-third are predaceous. True bugs have forewings, or hemelytra, that cross over the back at rest, but sometimes the wings are reduced

Beneficial Insects: Beetles

There are many beneficial beetles in Utah besides lady beetles or ladybugs. Beetles can significantly reduce common insect and weed problems and in some cases eliminate the need for chemical control. Examples of beneficial beetles include: ground beetles, rove beetles, tiger beetles and tortoise beetles. Many of these beetles are native to Utah, while others have been purposely introduced to help control damage from exotic insect and weed pests

03. Skeletal variation in Didelphis virginiana (Runner up - Best Overall Presentation)

Assessing sexual dimorphism is one method for understanding how species determine mating rights. In this study, we measured the skeletons of Didelphis virginiana (Virginia opossum) to determine the degree of sexual dimorphism present in our sample (N=68). Each specimen is collected as roadkill from northern Georgia, sexed, given an identification number, and skeletonized using a dermestid beetle colony on the UNG Dahlonega campus. When possible based on skeletal damage, we collected 11 cranial and 8 post-cranial measurements from each skeleton. This dataset will be compared to a large dataset from central Georgia to determine potential differences across habitat scales in Georgia. In addition, our study investigates size relationships within the skeleton of Dideliphis virginiana. Understanding this correlation can help infer the overall size of an individual when only some bones are present, which will prove valuable for understanding body size estimates in fossil marsupials. These analyses will provide an interpretive framework for elucidating the neo- and paleoecology of this important taxon

Student Characteristics Associated With Girls' Success in a Single-Sex School

This is the author's accepted manuscript. The original publication is available at: http://dx.doi.org/10.1007/s11199-010-9904-1Given the mixed results of previous studies on the benefits of single-sex schooling, scholars have called for research on differences in the effects of single-sex schooling based on student and school characteristics. We sought to examine the associations of a range of student characteristics with attitudes and achievement among students attending an all-girls public middle school in the southwestern United States. Predictor variables included demographic factors (i.e., race, family income), prior academic achievement, gender stereotyping, and gender identity (i.e., gender typicality, peer preferences). Prior academic achievement predicted later achievement and persistence in the single-sex school. School-related stereotyping was associated with success in and connection to the single-sex school; school connection was also a significant moderator of the relation between stereotyping and academic performance. Gender-typed peer preferences were associated with school connection and persistence. Overall, results indicate that student characteristics, as well as issues of “fit” with the specific school, are associated with students’ connection to and success in single-sex educational environments

Human Pathogen Shown to Cause Disease in the Threatened Elkhorn Coral Acropora palmata

Coral reefs are in severe decline. Infections by the human pathogen Serratia marcescens have contributed to precipitous losses in the common Caribbean elkhorn coral, Acropora palmata, culminating in its listing under the United States Endangered Species Act. During a 2003 outbreak of this coral disease, called acroporid serratiosis (APS), a unique strain of the pathogen, Serratia marcescens strain PDR60, was identified from diseased A. palmata, human wastewater, the non-host coral Siderastrea siderea and the corallivorous snail Coralliophila abbreviata. In order to examine humans as a source and other marine invertebrates as vectors and/or reservoirs of the APS pathogen, challenge experiments were conducted with A. palmata maintained in closed aquaria to determine infectivity of strain PDR60 from reef and wastewater sources. Strain PDR60 from wastewater and diseased A. palmata caused disease signs in elkhorn coral in as little as four and five days, respectively, demonstrating that wastewater is a definitive source of APS and identifying human strain PDR60 as a coral pathogen through fulfillment of Koch\u27s postulates. A. palmata inoculated with strain PDR60 from C. abbreviata showed limited virulence, with one of three inoculated fragments developing APS signs within 13 days. Strain PDR60 from non-host coral S. siderea showed a delayed pathogenic effect, with disease signs developing within an average of 20 days. These results suggest that C. abbreviata and non-host corals may function as reservoirs or vectors of the APS pathogen. Our results provide the first example of a marine \u27\u27reverse zoonosis\u27\u27 involving the transmission of a human pathogen (S. marcescens) to a marine invertebrate (A. palmata). These findings underscore the interaction between public health practices and environmental health indices such as coral reef survival

Exploring the Relationship Between COVID-19 Unit Designation and Nurse Burnout Syndrome

Background: The COVID-19 pandemic impacted healthcare due to surges in infected patient and respiratory failure. Nursing burnout syndrome (NBS) results from occupational factors leading to mental health problems. Nurses working in intensive care units (ICUs) dedicated to caring for COVID-19infected individuals may be even more susceptible to NBS due to increased burdens of futile care delivery and high mortality rates within overstretched healthcare systems. Identifying socio-demographic, work-related, and psychological predictors of NBS may help organizations mitigate, or at least minimize, the negative psychological impact on ICU nurses working during future pandemics. Purpose/Aims: The aim of this study was to compare burnout levels in ICU nurses providing direct care to COVID infected patients with nurses caring for non-COVID infected patients. Methods: An observational descriptive study was conducted using 1) a case-controlled prospective quantitative comparative design to compare neonatal and pediatric ICU to cardiac and medical ICU survey scores measuring nurse burnout, work-related, and psychological predictors of NBS and 2) across-sectional longitudinal quantitative causal and comparative study design comparing NBS scores for nurses working in a cardiac and medical ICU captured in 2019 prior to the COVID-19 pandemic to scores captured in the same units after conversion to dedicated COVID-19 ICUs in 2020. This study will explore the relationship between three subscales(Emotional Exhaustion, Depersonalization, and Personal Accomplishment) of the Maslach Burnout Inventory (MBI) as outcome variables and exposure to COVID-19 infected patients during 12-hour shifts worked as explanatory variables in a subset regression model. The study will also measure four subscales (Vocation, Finances, Health, and Social Relationships) associated with post-traumatic stress disorder using the Well Being Instrument(WBI) as control variables. A convenience sample of direct care registered nurses working in four ICUs in a large tertiary care hospital will be recruited to participate in the study. Female nurses working day shifts were surveyed in February and March 2019in two ICUs. In November 2020, four ICUs were used for sampling of both male and female nurses working either day or night 12-hour shifts based on designation as COVID-19 ICUs. Results: Researchers hypothesize burnout scores among nurses working in neonatal and pediatric ICUs will be less than burnout scores for nurses working in designated COVID ICUs. Additionally, investigators hypothesize nurse burnout measured in cardiac and medical ICUs in 2019 will be less than measurements obtained in 2020 after the same ICUs converted into COVID ICUs. This study will also analyze participant socio-demographic and work-related data for psychological predictors of NBS. Conclusion: NBS has been identified as a global problem facing ICU clinicians. Pinpointing associations betweenCOVID-19 infection and nurse burnout may lead to innovative strategies to mitigate burnout in those caring for the most critically ill individuals during future pandemics. Implications for practice: Further research is required to establish relationships between socio-demographic and work-related psychological predictors of NBS. Understanding relationships between these variables may guide development of strategies to build nurse resilience and decrease NBS in ICU settings impacted during pandemics.https://digitalcommons.psjhealth.org/prov_rn_conf_all/1009/thumbnail.jp

Activation of the IκB Kinase Complex and Nuclear Factor-κB Contributes to Mutant Huntingtin Neurotoxicity

Transcriptional dysregulation by mutant huntingtin (Htt) protein has been implicated in the pathogenesis of Huntington's disease (HD). We find that cultured cells expressing mutant Htt and striatal cells from HD transgenic mice have elevated nuclear factor-κB (NF-κB) activity. Furthermore, NF-κB is concentrated in the nucleus of neurons in the brains of HD transgenic mice. In inducible PC12 cells and in HD transgenic mice, mutant Htt activates the IκB kinase complex (IKK), a key regulator of NF-κB. Activation of IKK is likely mediated by direct interaction with mutant Htt, because the expanded polyglutamine stretch and adjacent proline-rich motifs in mutant Htt interact with IKKγ, a regulatory subunit of IKK. Activation of IKK may also influence the toxicity of mutant Htt, because expression of IKKγ promotes aggregation and nuclear localization of mutant Htt exon-1. Moreover, in acute striatal slice cultures, inhibition of IKK activity with an N-terminally truncated form of IKKγ blocks mutant Htt-induced toxicity in medium-sized spiny neurons (MSNs). In addition, blocking degradation of NF-κB inhibitors with a dominant-negative ubiquitin ligase β-transducin repeat-containing protein also reduces the toxicity of mutant Htt in MSNs. Therefore, aberrant NF-κB activation may contribute to the neurodegeneration induced by mutant Htt