A partnership-based, whole-watershed approach to climate adaptation in Acadia National Park

Changes in climate and associated changes in seasonality, invasive plants and insects, and visitation are stressing ecosystems and infrastructure in Acadia National Park. Over the past five years, park staff and partners have begun taking an interdisciplinary, partnership-based approach to assessing baseline conditions, identifying stresses, developing climate change scenarios, and restoring the ecological and cultural integrity and resilience of whole watersheds. The approach contrasts with past resource management in which managers frequently tackled problems with minimal coordination between disciplines (e.g., water, wildlife, cultural resources, and maintenance) and locations. The result has been a series of projects that have begun to measurably improve the health of one of the park’s most visited and iconic watersheds: the Cromwell Brook watershed, which includes Sieur de Monts (Acadia began in 1916 as Sieur de Monts National Monument) and the Great Meadow, and whose namesake waterway flows through the gateway town of Bar Harbor. Projects (inside and out of the park) have included rehabilitating a historic spring pool, replacing undersized culverts with open-bottom bridges, removing a poorly sited septic system, removing invasive plants, restoring native wetland, establishing monitoring to assess changes in watershed health, and working with the town and other stakeholders to plan future projects that would further improve the health of Great Meadow and downstream areas in Bar Harbor. The combination of planning; monitoring; restoring healthy, functioning ecological communities; and minimizing stresses from human infrastructure and visitation offer the best chance of main- taining Acadia National Park for the enjoyment of future generations

Neurocardiovascular Instability (NCVI) Risk as a Predictor of Cognitive Function in the Long Life Family Study

In aging populations, the abnormal neural control of the cardiovascular system has been examined within the construct of neurocardiovascular instability (NCVI). The main research aim addressed whether baseline features of NCVI could predict cognitive function (i.e., decline) at follow-up within long-lived families. Across 941 subjects, baseline NCVI risk was indexed by two features: (1) self-reported syncopal or fall events and (2) average seated BP. The Low NCVI risk group included those who were normotensive (e.g., within normal BP range) and reported no NCVI features (n=379). The Moderate NCVI risk group included those who elicited pre-hypertensive (elevated BP) or hypertensive (high BP) readings, indicating secondary NCVI risk (n=354). The High NCVI risk group included those who presented NCVI features (n=208). Generalized Estimating Equation models were run to compare baseline and follow-up cognitive performance (using global and multi-domain tests) by NCVI risk group. While NCVI exists in prodromal stages (as elicited by Moderate and High NCVI risk groups), its impacts on cognition seem to vary based on model type (e.g., cross-sectional, longitudinal). Subjects within the High NCVI risk group were found to elicit poorer processing speed cross-sectionally whilst semantic fluency remained intact at the longitudinal timepoint. In order to better understand NCVI etiology and progression towards cognitive impairment, we encourage future research models to incorporate both individuals at prodromal (e.g., elicit occasional NCVI features) and advanced stages (e.g., elicit pre-existing, chronic autonomic and/or neurodegenerative conditions) concurrently

Predicting Students’ College Drop Out and Departure Decisions by Analyzing their Campus-Based Social Network Text Messages

Undergraduate student retention is a key concern in the US higher education system. Having a scientific method for predicting undergraduate student departure would enable institutions to deploy targeted interventions with the goal of retaining a particular student who is at risk of dropping out. We explore the use of Latent Dirichlet Allocation (LDA), Systemic Functional Linguistics (SFL), and new techniques for Social Network Analytics addressing student communications within a novel campus-based closed social networking platform. Our research results indicate that students who were ultimately retained sent three times as many messages than those who were not, and analyzing the patterns of use of the closed social network in an academic setting reliably predicts undergraduate student dropouts and leads to a more effective deployment of retention resources over time

The Dominance Concept Inventory: A Tool for Assessing Undergraduate Student Alternative Conceptions about Dominance in Mendelian and Population Genetics

Despite the impact of genetics on daily life, biology undergraduates understand some key genetics concepts poorly. One concept requiring attention is dominance, which many students understand as a fixed property of an allele or trait and regularly conflate with frequency in a population or selective advantage. We present the Dominance Concept Inventory (DCI), an instrument to gather data on selected alternative conceptions about dominance. During development of the 16-item test, we used expert surveys (n = 12), student interviews (n = 42), and field tests (n = 1763) from introductory and advanced biology undergraduates at public and private, majority- and minority-serving, 2- and 4-yr institutions in the United States. In the final field test across all subject populations (n = 709), item difficulty ranged from 0.08 to 0.84 (0.51 ± 0.049 SEM), while item discrimination ranged from 0.11 to 0.82 (0.50 ± 0.048 SEM). Internal reliability (Cronbach\u27s alpha) was 0.77, while test–retest reliability values were 0.74 (product moment correlation) and 0.77 (intraclass correlation). The prevalence of alternative conceptions in the field tests shows that introductory and advanced students retain confusion about dominance after instruction. All measures support the DCI as a useful instrument for measuring undergraduate biology student understanding and alternative conceptions about dominance

Repurposing of robenidine and characterization of novel analogues for treatment of infectious diseases

Infectious diseases are one of the leading causes of morbidity and mortality worldwide. Diseases caused by single-celled organisms, such as bacteria and protista, cause billions of infections per year. One of the leading weapons in the fight against infectious diseases are antimicrobials. However, the efficacy of antimicrobials is decreasing as the development of antimicrobial resistance increases. At the same time as increasing levels of resistance are observed there is a lack of new antimicrobial agents entering the market and many big pharmaceutical companies have suspended antimicrobial drug discovery programs as financial return is small. Due to the lack of novel treatments for infectious diseases and increasing treatment failures it is essential that new chemical entities are explored to fill this gap. In this thesis a novel library of compounds based on the structure of robenidine, an approved antimicrobial used to prevent coccidiosis in chickens and rabbits, was investigated as potential antimicrobial agents. Initial experiments focussed on the antibacterial activity of the library against representative pathogenic bacteria. Activity was assessed according to CLSI guidelines. The spectrum of activity of the majority of analogues investigated was limited to Gram-positive bacteria, with promising MICs as low as 1.3 μM. However, through the use of outer-membrane permeabilising agents and spheroplast induction, it was discovered that the target site of robenidine and some of the related analogues was also present in Gram-negative organisms. This led to the development of a small subset of analogues which demonstrated intrinsic activity against the Gram-negative pathogens Escherichia coli and Pseudomonas aeruginosa with MICs as low as 52 μM. Furthermore, kill kinetic studies revealed that robenidine and related analogues had a bactericidal mechanism of action. The next series of experiments focussed on the characterisation of the antiparasitic activity of the library against the protists Trypanosoma brucei, Leishmania donovani and Giardia duodenalis. Several of the analogues demonstrated activity against these parasites with some promising results against Leishmania donovani including a small number of analogues with selectivity indices (SI) for the parasite above 20 (an SI of >10 is considered selective). In addition, activity against G. duodenalis was also promising (IC50 <1 μM). In total 121 analogues were tested against G. duodenalis with 13 being selective for Giardia with no antibacterial activity and limited, if any, toxicity towards mammalian cells. MICs for the most promising analogues were ≤ 2.8 μM. Electron microscopy studies to elucidate the mechanism or site of action of this class of antimicrobials against G. duodenalis demonstrated that the two most promising compounds both caused rapid disintegration of the cell membrane and the development of cyst-like structures, while one analogue also appeared to interfere with cell division. Finally, in order to test in vivo efficacy an animal model was effectively established in neonatal mice. In conclusion this thesis demonstrated for the first time the potential for this library of compounds to become therapeutic agents for a range of infectious diseases. In particular, the selective activity of several analogues for Giardia over other microorganisms and mammalian cells was demonstrated for the first time, highlighting the potential for this library of analogues. In addition, insight into the unique mechanism of action of a select group of compounds against G. duodenalis was demonstrated.Thesis (Ph.D.) -- University of Adelaide, School of Animal and Veterinary Sciences, 201

Comparative evaluation of a novel solar powered low-cost ophthalmoscope (Arclight) by eye healthcare workers in Malawi

This study compared a novel low-cost solar powered direct ophthalmoscope called the Arclight with a traditional direct ophthalmoscope (TDO). After appropriate training, 25 Malawian eye healthcare workers were asked to examine 12 retinal images placed in a teaching manikin head with both the Arclight ophthalmoscope and a traditional direct ophthalmoscope (Keeler Professional V.2.8). Participants were scored on their ability to identify clinical signs, to make a diagnosis and how long they took to make a diagnosis. They were also asked to score each ophthalmoscope for ‘ease of use’. Statistically significant differences were found in favour of the Arclight in the number of clinical signs identified, correct diagnoses made and ease of use. The ophthalmoscopes were equally effective as a screening tool for diabetic retinopathy, and there was no statistically difference in time to diagnosis. The authors conclude that the Arclight offers an easy to use, low cost alternative to the traditional direct ophthalmoscope to meet the demands for screening and diagnosis of visually impairing eye disorders in low-income and middle-income countries.Publisher PDFPeer reviewe

Neighborhood Racial Discrimination and the Development of Major Depression

This study examined the impact of neighborhood racial discrimination on the development of major depressive disorder (MDD) in a sample of African American women. Participants were 499 women from Georgia and Iowa with no history of MDD who were followed for 9 to 11 years. Several neighborhood characteristics (community social disorder, community cohesion, and community racism) and individual characteristics (negative life events, financial strain, personal outlook, religious involvement, relationship quality, negative affectivity, and individual experiences of racism) were employed as predictors of whether or not the women met criteria for MDD during this period of time. In a multilevel logistic regression analysis, neighborhood-level discrimination as well as individual-level variables including the number of negative life events, financial strain, and negative affectivity were found to be significant predictors of developing MDD. Analyses of cross-level interactions indicated that the effects of neighborhood-level discrimination were moderated by the quality of individuals’ relationships, such that better relationships with others served to lessen the effect of neighborhood discrimination on depression. Implications of these findings for understanding the negative effects of racial discrimination are discussed