Powdery mildew in wine grapes in Western Australia

Powdery mildew is caused by the fungal pathogen Uncinula necator. It is the most persistent fungal problem of grapes in WA and one of the most widespread fungal diseases of grapevines in the world. It is characterised by ash-grey to white powdery growth on green tissue of the vine. If uncontrolled it can cause serious crop losses and impair wine quality.https://researchlibrary.agric.wa.gov.au/bulletins/1076/thumbnail.jp

Rich Learning Activities: Engaging Students in Postsecondary Classrooms

Keeping with the conference theme of “Doing More with Less”, the author of Guide to Classroom Engagement, reviews the principles of engaging teaching, and presents a rich menu of simple, practical, user-friendly learning activities that have been demonstrated to enhance student learning, retention, and success. Dr. Fisher’s highly interactive workshop invites audience participation in addressing both the benefits and the challenges of engaging students in post-secondary science classrooms

The entry knowledge of Australian pre-service teachers in the area of phonological awareness and phonics

The link between research and practice has never been more significant as global awareness about literacy pushes us to question the success of programs in schools. National reports on literacy were challenged during the conference. Grounded evidence was given of literacy programs that work to make a difference for groups with diverse needs. The collection of ideas in the conference represents a broad concept of literacy that includes the ability to communicate in multimodal, digital texts and values creativity alongside testing for skills. Classroom based research from the sum of these perspectives presents significant reason for change to practice and policy.To make a difference to future generations of students, we need to take the research out of the classroom and make it the centre of informed debate. This publication is a step towards achieving that goal. [From publisher\u27s website

An empirical examination of echo chambers in US climate policy networks

Diverse methods have been applied to understand why science continues to be debated within the climate policy domain. A number of studies have presented the notion of the ‘echo chamber’ to model and explain information flows across an array of social settings, finding disproportionate connections among ideologically similar political communicators. This paper builds on these findings to provide a more formal operationalization of the components of echo chambers. We then empirically test their utility using survey data collected from the community of political elites engaged in the contentious issue of climate politics in the United States. Our survey period coincides with the most active and contentious period in the history of US climate policy, when legislation regulating carbon dioxide emissions had passed through the House of Representatives and was being considered in the Senate. We use exponential random graph (ERG) modelling to demonstrate that both the homogeneity of information (the echo) and multi-path information transmission (the chamber) play significant roles in policy communication. We demonstrate that the intersection of these components creates echo chambers in the climate policy network. These results lead to some important conclusions about climate politics, as well as the relationship between science communication and policymaking at the elite level more generally.US National Science FoundationNational Socio-Environmental Synthesis Center (SESYNC

Investigating the neuroprotective effect of exercise; the role of redox homeostasis

The balance between oxidant production and the antioxidant defence system is essential to brain health. First-episode psychosis (FEP) and schizophrenia (SZ) are psychiatric disorders that affect the patients’ contact with reality, with unique presentation of symptoms and experiences. Both FEP and SZ can be characterised by perturbed redox status, notably via antioxidant depletion. Previous research, undertaken in healthy populations, has highlighted the ability of exercise training to regulate redox balance. One particular biomarker of redox status is the antioxidant glutathione (GSH), which has a principal role of removing toxic substances from the cell, especially in the brain. This thesis presents novel data investigating the drawbacks of exercise study design in youth mental health, the efficacy of a training intervention in ‘normalising’ measures of antioxidant capacity, oxidative stress, inflammation and functionality in FEP. Studies presented go on to interrogate some of the redox-related mechanisms of the neurodevelopmental aspect of psychosis pathophysiology. Assessment of GSH in the brain, blood and in patient-derived cell models offers significant gateways into elucidating the pathological mechanisms of mental ill-health. In order to address some of the principle weaknesses in previous study design which have aimed to provide exercise to a FEP cohort, chapter 2 of this thesis used personalised heart rate zones (50-70% VO2max) to standardise bouts of activity across a range of exercise modalities, in a healthy but sedentary group of young people. The study was successful in provoking a redox response 2 during each acute bout, which typically initiates the stimulation of adaptive processes. This study achieved 100% retention, which also demonstrated that engagement in an exercise intervention is possible in a sedentary group, when choice of activity and variety of exercise mode are offered to the participant. Chapters 3 and 4 highlight the therapeutic benefits of regular exercise training (12 weeks, 3-4 times/week, 40-60 minutes) for FEP patients in a randomised trial. The study highlighted the positive impact of increased physical activity on peripheral and brain indices of GSH, markers of oxidative stress, and patient- centred measures of psychotic symptomology and daily function. In a more in- depth assessment of the GSH cycle and indices of cell damage, chapter 5 describes the characterisation and generation of mature astrocytes and neurons from SZ patient-derived induced pluripotent stem cells (iPSCs), as a model of the neurodevelopmental aspect of disease pathogenesis. It was found that the de-toxifying ability of GSH is impaired in SZ cerebral cells, offering a cogent target for further investigation in this novel approach to assessing the mechanisms of mental ill-health, in the brain

Shifting echo chambers in US climate policy networks

This is the final version. Available on open access from Public Library of Science via the DOI in this recordData Availability: Data are available from the Climate Constituencies study at http://drfisher.umd.edu/CCP_REVISED.html.Although substantial attention has focused on efforts by the new Administration to block environmental policies, climate politics have been contentious in the US since well before the election of Donald Trump. In this paper, we extend previous work on empirical examinations of echo chambers in US climate politics using new data collected on the federal climate policy network in summer 2016. We test for the similarity and differences at two points in time in homophily and echo chambers using Exponential Random Graph Models (ERGM) to compare new findings from 2016 to previous work on data from 2010. We show that echo chambers continue to play a significant role in the network of information exchange among policy elites working on the issue of climate change. In contrast to previous findings where echo chambers centered on a binding international commitment to emission reductions, we find that the pre-existing echo chambers have almost completely disappeared and new structures have formed around one of the main components of the Obama Administration’s national climate policy: the Clean Power Plan. These results provide empirical evidence that science communication and policymaking at the elite level shift in relation to the policy instruments under consideration.MacArthur Foundatio

Polarization of coalitions in an agent-based model of political discourse

Political discourse is the verbal interaction between political actors in a policy domain. This article explains the formation of polarized advocacy or discourse coalitions in this complex phenomenon by presenting a dynamic, stochastic, and discrete agent-based model based on graph theory and local optimization. In a series of thought experiments, actors compute their utility of contributing a specific statement to the discourse by following ideological criteria, preferential attachment, agenda-setting strategies, governmental coherence, or other mechanisms. The evolving macro-level discourse is represented as a dynamic network and evaluated against arguments from the literature on the policy process. A simple combination of four theoretical mechanisms is already able to produce artificial policy debates with theoretically plausible properties. Any sufficiently realistic configuration must entail innovative and path-dependent elements as well as a blend of exogenous preferences and endogenous opinion formation mechanisms

A frequentist framework of inductive reasoning

Reacting against the limitation of statistics to decision procedures, R. A. Fisher proposed for inductive reasoning the use of the fiducial distribution, a parameter-space distribution of epistemological probability transferred directly from limiting relative frequencies rather than computed according to the Bayes update rule. The proposal is developed as follows using the confidence measure of a scalar parameter of interest. (With the restriction to one-dimensional parameter space, a confidence measure is essentially a fiducial probability distribution free of complications involving ancillary statistics.) A betting game establishes a sense in which confidence measures are the only reliable inferential probability distributions. The equality between the probabilities encoded in a confidence measure and the coverage rates of the corresponding confidence intervals ensures that the measure's rule for assigning confidence levels to hypotheses is uniquely minimax in the game. Although a confidence measure can be computed without any prior distribution, previous knowledge can be incorporated into confidence-based reasoning. To adjust a p-value or confidence interval for prior information, the confidence measure from the observed data can be combined with one or more independent confidence measures representing previous agent opinion. (The former confidence measure may correspond to a posterior distribution with frequentist matching of coverage probabilities.) The representation of subjective knowledge in terms of confidence measures rather than prior probability distributions preserves approximate frequentist validity.Comment: major revisio

Light curves and spectra from a thermonuclear explosion of a white dwarf merger

This is the final version of the article. Available from the publisher via the DOI in this record.Double-degenerate (DD) mergers of carbon-oxygen white dwarfs have recently emerged as a leading candidate for normal Type Ia supernovae (SNe Ia). However, many outstanding questions surround DD mergers, including the characteristics of their light curves and spectra. We have recently identified a spiral instability in the post-merger phase of DD mergers and demonstrated that this instability self-consistently leads to detonation in some cases. We call this the spiral merger SN Ia model. Here, we utilize the SuperNu radiative transfer software to calculate three-dimensional synthetic light curves and spectra of the spiral merger simulation with a system mass of 2.1 from Kashyap et al. Because of their large system masses, both violent and spiral merger light curves are slowly declining. The spiral merger resembles very slowly declining SNe Ia, including SN 2001ay, and provides a more natural explanation for its observed properties than other SN Ia explosion models. Previous synthetic light curves and spectra of violent DD mergers demonstrate a strong dependence on viewing angle, which is in conflict with observations. Here, we demonstrate that the light curves and spectra of the spiral merger are less sensitive to the viewing angle than violent mergers, in closer agreement with observation. We find that the spatial distribution of 56Ni and IMEs follows a characteristic hourglass shape. We discuss the implications of the asymmetric distribution of 56Ni for the early-time gamma-ray observations of 56Ni from SN 2014J. We suggest that DD mergers that agree with the light curves and spectra of normal SNe Ia will likely require a lower system mass.This work is supported in part at the University of Chicago by the National Science Foundation under grants AST-0909132, PHY-0822648 (JINA, Joint Institute for Nuclear Astrophysics), and PHY–1430152 (JINA-CEE, Joint Institute for Nuclear Astrophysics). This work used the Extreme Science and Engineering Discovery Environment (XSEDE), which is supported by National Science Foundation grant number ACI-1053575. Simulations at UMass Dartmouth were performed on a computer cluster supported by NSF grant CNS-0959382 and AFOSR DURIP grant FA9550-10-1-0354. The work of E.G.-B., G.A.-S., and P. L.-A. was partially funded by the MINECO AYA2014-59084- P grant and by the AGAUR. This research has made use of NASA’s Astrophysics Data System and the yt astrophysics analysis software suit

An assessment of the potential impacts of climate change on the freshwater habitats of Indiana, U.S.A.

Recent climate-driven, physico-chemical changes documented in aquatic systems throughout the world are expected to intensify in the future. Specifically, changes in key environmental attributes of aquatic systems, such as water quantity, clarity, temperatures, ice cover, seasonal flow regimes, external loading, and oxygen content, will undoubtedly have a broad set of direct and indirect ecological consequences. Some anticipated impacts may be similar across different aquatic ecosystems, while others may be system-specific. Here, we review the potential effects of climatic changes for different freshwater habitats within the state of Indiana, USA, a Midwestern state with diverse land and water features. Given this heterogeneity and that the state is among the southernmost states of the US Midwest, evaluation of freshwater habitats of Indiana provides a useful perspective on potential impacts of climate change. In our study, we first review expected or anticipated changes to physico-chemical and habitat conditions in wetlands, lotic systems, small glacial lakes and Lake Michigan. We then highlight anticipated responses of select aquatic biota to these changes. We describe how climatic changes may interact with other anthropogenic stressors affecting freshwater habitats and consider the potential for evolutionary adaptation of freshwater aquatic organisms to mediate any responses. Given anticipated changes, we suggest aquatic ecosystem managers take a precautionary approach broadly applicable in temperate regions to (a) conserve a diversity of aquatic habitats, (b) enhance species diversity and both inter- and intra-population genetic variation, and (c) limit stressors which may exacerbate the risk of decline for aquatic biota