My Foot is a Desert

My work is inspired by experiences I have had while hiking in the deserts of the American West and northern Mexico. While these desert regions are sparse, they are surprisingly rich in biodiversity. This arid abundance creates beautifully stark wilderness. It is the wild plant forms in these landscapes – the chalky yet silky saguaro rib, the fine fibers that feather and spin off a yucca blade – that inspire this body of prints. These are plants that I touch, taste, admire, and am fascinated with

Amphetamine Exposure During Embryogenesis Leads To Long-Term And Transgenerational Increase In Behavioral Response And Decrease In Dopamine Uptake

Amphetamine (AMPH) is widely prescribed for the treatment of ADHD and a highly abused substance in society, yet little is known about the long-term effects of the drug. Here, we used Caenorhabditis elegans (C. elegans) to establish a model for the long-term and transgenerational effects of AMPH exposure on behavior. Furthermore, experiments were conducted to explore the molecular mechanisms of AMPH that were altered by embryonic AMPH exposure. C. elegans have a well characterized behavioral response to AMPH known as Swimming Induced Paralysis (SWIP). For the SWIP test, animals are placed in fluid, which normally induces a thrashing behavior. However, in the presence AMPH, the animals display a time- and dose-dependent paralysis. AMPH increases the levels of dopamine in the synapse by causing reverse transport through the protein known as the dopamine transporter (DAT), and the SWIP behavior has been shown to be dependent on dopaminergic transmission. We exposed embryos to either control solution alone (M9 solution) or 500μM AMPH dissolved in control solution for 15 hours. 4 days later the SWIP test was performed on young adult animals, revealing that animals previously exposed to AMPH as embryos displayed a higher response to AMPH. The progeny of both groups were tested for SWIP as well. Interestingly, the progeny of the animals exposed to AMPH as embryos showed a higher SWIP response with respect to the progeny of control animals, demonstrating that AMPH had both a long-term and transgenerational effect on the animals. Because the SWIP behavior was previously shown to be dependent on dopaminergic transmission, we performed DA uptake assays using primary cell cultures made from F1 generation animals to investigate alterations in DATs ability to uptake dopamine. Results from the uptake assays showed that primary cultures made from the progeny of animals exposed to AMPH as embryos had reduced ability to uptake DA with respect to control cultures. To further investigate the reduced uptake ability following AMPH exposure, a human neuroblastoma cell line (SH-SY5Y) was exposed to 15 hour of AMPH, and 5 days later, a DA uptake assay using a concentration response of DA was carried out. Results showed that the cells had a reduced Vmax with no change to Km, suggesting a reduced amount of DAT in the cells. We investigated changes in histone methylation as a mechanism for the long-term and transgenerational effect observed. Histones are proteins, which DNA wraps around to form the nucleosome, and methylation changes on histones can modify the binding of DNA to histones leading to a change in gene expression. Western blots of whole animal protein revealed a decreased level of histone 3 lysine 4 trimethylation (H3K4me3) in the F1 generation of AMPH exposed animals. Additionally, a reduction in the enzymes responsible for H3K4me2 methylation and H3K4me3 demethylation was observed in F1 progeny of AMPH exposed animals. Suggesting that AMPH exposure during embryogenesis alters methylation of specific histone markers. Taken together, these experiments show that in C. elegans, AMPH exposure causes a long-term and transgenerational alteration in behavioral response to AMPH, which correlates to alterations in DAT uptake ability

VII. On the solitary wave

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Expansion of the Distance Modality in Brazilian Higher Education: Implications for Quality and Equity

With globalization and the knowledge society, the expansion of higher education has become an ‘object of desire’ among governments to bolster both economic growth and social development. In recent decades, just as in other countries, Brazil has expanded the system and become the fourth largest in the world in enrollment numbers, significantly increasing distance education at for-profit private institutions. However, massification without the necessary attention to quality and equity may present undesired consequences. Thus, considering Brazil has created one of the largest information databases that allow for studies with huge samples, we statistically analyzed performance in a wide scale national examination (Enade) with approximately 222,000 students, disaggregated by background and education modalities. The results back the argument that learning possibilities and performance in distance education are inferior in relation to in-person modalities and that the expansion based on distance education at for-profit private institutions may be reproducing inequalities within the higher education system in one of the most unequal nations in the world

Random Diffusion Model with Structure Corrections

The random diffusion model is a continuum model for a conserved scalar density field driven by diffusive dynamics where the bare diffusion coefficient is density dependent. We generalize the model from one with a sharp wavenumber cutoff to one with a more natural large-wavenumber cutoff. We investigate whether the features seen previously -- namely a slowing down of the system and the development of a prepeak in the dynamic structure factor at a wavenumber below the first structure peak -- survive in this model. A method for extracting information about a hidden prepeak in experimental data is presented.Comment: 13 pages, 8 figure

ePortfolios: Mediating the minefield of inherent risks and tensions

The ePortfolio Project at the Queensland University of Technology (QUT) exemplifies an innovative and flexible harnessing of current portfolio thinking and design that has achieved substantial buy-in across the institution with over 23000 active portfolios. Robust infrastructure support, curriculum integration and training have facilitated widespread take-up, while QUT’s early adoption of ePortfolio technology has enabled the concomitant development of a strong policy and systems approach to deal explicitly with legal and design responsibilities. In the light of that experience, this paper will highlight the risks and tensions inherent in ePortfolio policy, design and implementation. In many ways, both the strengths and weaknesses of ePortfolios lie in their ability to be accessed by a wider, less secure audience – either internally (e.g. other students and staff) or externally (e.g. potential employees and referees). How do we balance the obvious requirement to safeguard students from the potential for institutionally-facilitated cyber-harm and privacy breaches, with this generation’s instinctive personal and professional desires for reflections, private details, information and intellectual property to be available freely and with minimal restriction? How can we promote collaboration and freeform expression in the blog and wiki world but also manage the institutional risk that unauthorised use of student information and work so palpably carries with it? For ePortfolios to flourish and to develop and for students to remain engaged in current reflective processes, holistic guidelines and sensible boundaries are required to help safeguard personal details and journaling without overly restricting students’ emotional, collaborative and creative engagement with the ePortfolio experience. This paper will discuss such issues and suggest possible ways forward

Long-term safety and efficacy of lowering low-density lipoprotein cholesterol with statin therapy : 20-year follow-up of West of Scotland Coronary Prevention Study

The study was supported by a grant from Merck, Sharp & Dohme, Kenilworth, NJ, as part of an Investigator Initiated Program.BACKGROUND Extended follow-up of statin-based low-density lipoprotein cholesterol lowering trials improves the understanding of statin safety and efficacy. Examining cumulative cardiovascular events (total burden of disease) gives a better appreciation of the clinical value of statins. This article evaluates the long-term impact of therapy on mortality and cumulative morbidity in a high-risk cohort of men. METHODS AND RESULTS The West of Scotland Coronary Prevention Study was a primary prevention trial in 45- to 64-year-old men with high low-density lipoprotein cholesterol. A total of 6595 men were randomized to receive pravastatin 40 mg once daily or placebo for an average of 4.9 years. Subsequent linkage to electronic health records permitted analysis of major incident events over 20 years. Post trial statin use was recorded for 5 years after the trial but not for the last 10 years. Men allocated to pravastatin had reduced all-cause mortality (hazard ratio, 0.87; 95% confidence interval, 0.80-0.94; P=0.0007), attributable mainly to a 21% decrease in cardiovascular death (hazard ratio, 0.79; 95% confidence interval, 0.69-0.90; P=0.0004). There was no difference in noncardiovascular or cancer death rates between groups. Cumulative hospitalization event rates were lower in the statin-treated arm: by 18% for any coronary event (P=0.002), by 24% for myocardial infarction (P=0.01), and by 35% for heart failure (P=0.002). There were no significant differences between groups in hospitalization for noncardiovascular causes. CONCLUSION Statin treatment for 5 years was associated with a legacy benefit, with improved survival and a substantial reduction in cardiovascular disease outcomes over a 20-year period, supporting the wider adoption of primary prevention strategies.Publisher PDFPeer reviewe

Decoupling social status and status certainty effects on health in macaques: a network approach.

BackgroundAlthough a wealth of literature points to the importance of social factors on health, a detailed understanding of the complex interplay between social and biological systems is lacking. Social status is one aspect of social life that is made up of multiple structural (humans: income, education; animals: mating system, dominance rank) and relational components (perceived social status, dominance interactions). In a nonhuman primate model we use novel network techniques to decouple two components of social status, dominance rank (a commonly used measure of social status in animal models) and dominance certainty (the relative certainty vs. ambiguity of an individual's status), allowing for a more complex examination of how social status impacts health.MethodsBehavioral observations were conducted on three outdoor captive groups of rhesus macaques (N = 252 subjects). Subjects' general physical health (diarrhea) was assessed twice weekly, and blood was drawn once to assess biomarkers of inflammation (interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and C-reactive protein (CRP)).ResultsDominance rank alone did not fully account for the complex way that social status exerted its effect on health. Instead, dominance certainty modified the impact of rank on biomarkers of inflammation. Specifically, high-ranked animals with more ambiguous status relationships had higher levels of inflammation than low-ranked animals, whereas little effect of rank was seen for animals with more certain status relationships. The impact of status on physical health was more straightforward: individuals with more ambiguous status relationships had more frequent diarrhea; there was marginal evidence that high-ranked animals had less frequent diarrhea.DiscussionSocial status has a complex and multi-faceted impact on individual health. Our work suggests an important role of uncertainty in one's social status in status-health research. This work also suggests that in order to fully explore the mechanisms for how social life influences health, more complex metrics of social systems and their dynamics are needed

Functional Brain Imaging with Multi-Objective Multi-Modal Evolutionary Optimization

Functional brain imaging is a source of spatio-temporal data mining problems. A new framework hybridizing multi-objective and multi-modal optimization is proposed to formalize these data mining problems, and addressed through Evolutionary Computation (EC). The merits of EC for spatio-temporal data mining are demonstrated as the approach facilitates the modelling of the experts' requirements, and flexibly accommodates their changing goals

Exploration and confirmation of factors associated with uncomplicated pregnancy in nulliparous women: prospective cohort study

Objective: To identify factors at 15 and 20 weeks’ gestation associated with a subsequent uncomplicated pregnancy. Design: Prospective international multicentre observational cohort study. Setting: Auckland, New Zealand and Adelaide, Australia (exploration and local replication dataset) and Manchester, Leeds, and London, United Kingdom, and Cork, Republic of Ireland (external confirmation dataset). Participants: 5628 healthy nulliparous women with a singleton pregnancy. Main outcome measure: Uncomplicated pregnancy, defined as a normotensive pregnancy delivered at >37 weeks’ gestation, resulting in a liveborn baby not small for gestational age, and the absence of any other significant pregnancy complications. In a stepwise logistic regression the comparison group was women with a complicated pregnancy. Results: Of the 5628 women, 3452 (61.3%) had an uncomplicated pregnancy. Factors that reduced the likelihood of an uncomplicated pregnancy included increased body mass index (relative risk 0.74, 95% confidence intervals 0.65 to 0.84), misuse of drugs in the first trimester (0.90, 0.84 to 0.97), mean diastolic blood pressure (for each 5 mm Hg increase 0.92, 0.91 to 0.94), and mean systolic blood pressure (for each 5 mm Hg increase 0.95, 0.94 to 0.96). Beneficial factors were prepregnancy fruit intake at least three times daily (1.09, 1.01 to 1.18) and being in paid employment (per eight hours’ increase 1.02, 1.01 to 1.04). Detrimental factors not amenable to alteration were a history of hypertension while using oral contraception, socioeconomic index, family history of any hypertensive complications in pregnancy, vaginal bleeding during pregnancy, and increasing uterine artery resistance index. Smoking in pregnancy was noted to be a detrimental factor in the initial two datasets but did not remain in the final model. Conclusions: This study identified factors associated with normal pregnancy through adoption of a novel hypothesis generating approach, which has shifted the emphasis away from adverse outcomes towards uncomplicated pregnancies. Although confirmation in other cohorts is necessary, this study implies that individually targeted lifestyle interventions (normalising maternal weight, increasing prepregnancy fruit intake, reducing blood pressure, stopping misuse of drugs) may increase the likelihood of normal pregnancy outcomes.Lucy C Chappell, Paul T Seed, Jenny Myers, Rennae S Taylor, Louise C Kenny, Gustaaf A Dekker, James J Walker, Lesley M E McCowan, Robyn A North, Lucilla Posto