Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2019 ( 7 )

2018 ( 12 )

2017 ( 24 )

2016 ( 19 )

Custom range...

Search Results: 1 - 10 of 4397 matches for " Ken Dawson-Scully "
All listed articles are free for downloading (OA Articles)
Page 1 /4397
Display every page Item
Combination of Sulindac and Dichloroacetate Kills Cancer Cells via Oxidative Damage
Kasirajan Ayyanathan, Shailaja Kesaraju, Ken Dawson-Scully, Herbert Weissbach
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0039949
Abstract: Sulindac is an FDA-approved non-steroidal anti-inflammatory drug with documented anticancer activities. Our recent studies showed that sulindac selectively enhanced the killing of cancer cells exposed to oxidizing agents via production of reactive oxygen species (ROS) resulting in mitochondrial dysfunction. This effect of sulindac and oxidative stress on cancer cells could be related to the defect in respiration in cancer cells, first described by Warburg 50 years ago, known as the Warburg effect. We postulated that sulindac might enhance the selective killing of cancer cells when combined with any compound that alters mitochondrial respiration. To test this hypothesis we have used dichloroacetate (DCA), which is known to shift pyruvate metabolism away from lactic acid formation to respiration. One might expect that DCA, since it stimulates aerobic metabolism, could stress mitochondrial respiration in cancer cells, which would result in enhanced killing in the presence of sulindac. In this study, we have shown that the combination of sulindac and DCA enhances the selective killing of A549 and SCC25 cancer cells under the conditions used. As predicted, the mechanism of killing involves ROS production, mitochondrial dysfunction, JNK signaling and death by apoptosis. Our results suggest that the sulindac-DCA drug combination may provide an effective cancer therapy.
Natural Variation in the Thermotolerance of Neural Function and Behavior due to a cGMP-Dependent Protein Kinase
Ken Dawson-Scully, Gary A. B. Armstrong, Clement Kent, R. Meldrum Robertson, Marla B. Sokolowski
PLOS ONE , 2007, DOI: 10.1371/journal.pone.0000773
Abstract: Although it is acknowledged that genetic variation contributes to individual differences in thermotolerance, the specific genes and pathways involved and how they are modulated by the environment remain poorly understood. We link natural variation in the thermotolerance of neural function and behavior in Drosophila melanogaster to the foraging gene (for, which encodes a cGMP-dependent protein kinase (PKG)) as well as to its downstream target, protein phosphatase 2A (PP2A). Genetic and pharmacological manipulations revealed that reduced PKG (or PP2A) activity caused increased thermotolerance of synaptic transmission at the larval neuromuscular junction. Like synaptic transmission, feeding movements were preserved at higher temperatures in larvae with lower PKG levels. In a comparative assay, pharmacological manipulations altering thermotolerance in a central circuit of Locusta migratoria demonstrated conservation of this neuroprotective pathway. In this circuit, either the inhibition of PKG or PP2A induced robust thermotolerance of neural function. We suggest that PKG and therefore the polymorphism associated with the allelic variation in for may provide populations with natural variation in heat stress tolerance. for's function in behavior is conserved across most organisms, including ants, bees, nematodes, and mammals. PKG's role in thermotolerance may also apply to these and other species. Natural variation in thermotolerance arising from genes involved in the PKG pathway could impact the evolution of thermotolerance in natural populations.
Glial Hsp70 Protects K+ Homeostasis in the Drosophila Brain during Repetitive Anoxic Depolarization
Gary A. B. Armstrong, Chengfeng Xiao, Jennifer L. Krill, Laurent Seroude, Ken Dawson-Scully, R. Meldrum Robertson
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0028994
Abstract: Neural tissue is particularly vulnerable to metabolic stress and loss of ion homeostasis. Repetitive stress generally leads to more permanent dysfunction but the mechanisms underlying this progression are poorly understood. We investigated the effects of energetic compromise in Drosophila by targeting the Na+/K+-ATPase. Acute ouabain treatment of intact flies resulted in subsequent repetitive comas that led to death and were associated with transient loss of K+ homeostasis in the brain. Heat shock pre-conditioned flies were resistant to ouabain treatment. To control the timing of repeated loss of ion homeostasis we subjected flies to repetitive anoxia while recording extracellular [K+] in the brain. We show that targeted expression of the chaperone protein Hsp70 in glial cells delays a permanent loss of ion homeostasis associated with repetitive anoxic stress and suggest that this is a useful model for investigating molecular mechanisms of neuroprotection.
RanBP9 Plays a Critical Role in Neonatal Brain Development in Mice
Juan Pablo Palavicini, Brandon Noel Lloyd, Crystal D. Hayes, Elisabetta Bianchi, David E. Kang, Ken Dawson-Scully, Madepalli K. Lakshmana
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0066908
Abstract: RanBP9 is known to act as a scaffolding protein bringing together a variety of cell surface receptors and intracellular targets thereby regulating functions as diverse as neurite and axonal outgrowth, cell morphology, cell proliferation, myelination, gonad development, myofibrillogenesis and migration of neuronal precursors. Though RanBP9 is ubiquitously expressed in all tissues, brain is one of the organs with the highest expression levels of RanBP9. In the neurons, RanBP9 is localized mostly in the cytoplasm but also in the neurites and dendritic processes. We recently demonstrated that RanBP9 plays pathogenic role in Alzheimer’s disease. To understand the role of RanBP9 in the brain, here we generated RanBP9 null mice by gene-trap based strategy. Most of Ran?/? mice die neonatally due to defects in the brain growth and development. The major defects include smaller cortical plate (CP), robustly enlarged lateral ventricles (LV) and reduced volume of hippocampus (HI). The lethal phenotype is due to a suckling defect as evidenced by lack of milk in the stomachs even several hours after parturition. The complex somatosensory system which is required for a behavior such as suckling appears to be compromised in Ran?/? mice due to under developed CP. Most importantly, RanBP9 phenotype is similar to ERK1/2 double knockout and the neural cell adhesion receptor, L1CAM knockout mice. Both ERK1 and L1CAM interact with RanBP9. Thus, RanBP9 appears to control brain growth and development through signaling mechanisms involving ERK1 and L1CAM receptor.
The Effect of Performance Feedback on Student Help-Seeking and Learning Strategy Use: Do Clickers Make a Difference?
Debra L. Dawson,Ken N. Meadows,Tom Haffie
Canadian Journal for the Scholarship of Teaching and Learning , 2010,
Abstract: Two studies were performed to investigate the impact of students’ clicker performance feedback on their help-seeking behaviour and use of other learning strategies. In study 1, we investigated the relationship between students’ clicker performance, self-efficacy, help-seeking behavior, and academic achievement. We found that there was a significant positive correlation between their clicker performance and their course grades, and help-seeking behavior was negatively and significantly related to clicker and course performance but only for participants with high self-efficacy. In study 2, we expanded our focus to determine if participants modified a number of learning strategies as a result of receiving clicker performance feedback as well as attempting to replicate the clicker-course performance relationship found in study 1. Although participants reported an increase in their use of various learning strategies as a result of using the clickers, changes in learning strategy use was not significantly related to clicker or term test performance. The relationship between clicker and course performance was replicated. The results suggest that clicker-based feedback alone may not be sufficient to lead to a successful change in learning strategy use and that students may need more specific instruction on self-regulation and effective learning strategy use in order to improve their learning.Deux études ont évalué l’impact de la rétroaction sur la performance des étudiants indiquée par télévoteur sur leur comportement de recherche d’aide et sur les autres stratégies d’apprentissage utilisées. Dans la première étude, les chercheurs se sont penchés sur la relation entre la performance indiquée par télévoteur, le sentiment d’auto-efficacité, la recherche d’aide et la réussite scolaire. Nous avons trouvé une corrélation positive significative entre la performance indiquée par télévoteur et les notes de cours. De plus, nous avons également découvert un lien négatif significatif entre le comportement en matière de recherche d’aide, le télévoteur et la performance dans le cours, mais uniquement chez les participants ayant un sentiment d’auto-efficacité élevé. Dans la deuxième étude, nous avons élargi notre approche pour déterminer si les participants avaient modifié plusieurs stratégies d’apprentissage après avoir obtenu une rétroaction sur leur performance par télévoteur. Nous avons de plus tenté de répliquer la relation entre le télévoteur et la performance dans cours découverte lors de la première étude. Bien que les participants aient déclaré avoir utilisé davanta
Clinical EFT as an Evidence-Based Practice for the Treatment of Psychological and Physiological Conditions  [PDF]
Dawson Church
Psychology (PSYCH) , 2013, DOI: 10.4236/psych.2013.48092

Emotional Freedom Techniques (EFT) has moved in the past two decades from a fringe therapy to widespread professional acceptance. This paper defines Clinical EFT, the method validated in many research studies, and shows it to be an “evidence-based” practice. It describes standards by which therapies may be evaluated, such as those of the American Psychological Association (APA) Division 12 Task Force, and reviews the studies showing that Clinical EFT meets these criteria. Several research domains are discussed, summarizing studies of: 1) psychological conditions such as anxiety, depression, phobias, and posttraumatic stress disorder (PTSD); 2) physiological problems such as pain and autoimmune conditions; 3) professional and sports performance; and 4) the physiological mechanisms of action of Clinical EFT. The paper lists the conclusions that may be drawn from this body of evidence, which includes 23 randomized controlled trials and 17 within-subjects studies. The three essential ingredients of Clinical EFT are described: exposure, cognitive shift, and acupressure. The latter is shown to be an essential ingredient in EFT’s efficacy, and not merely a placebo. New evidence from emerging fields such as epigenetics, neural plasticity, psychoneuroimmunology, and evolutionary biology confirms the central link between emotion and physiology, and points to somatic stimulation as the element common to emerging psychotherapeutic methods. The paper outlines the next steps in EFT research, such as smartphone-based data gathering, large-scale group therapy, and the use of biomarkers. It concludes that Clinical EFT is a stable and mature method with an extensive evidence base. These characteristics have led to growing acceptance in primary care settings as a safe, rapid, reliable, and effective treatment for both psychological and medical diagnoses.

Why Marx Was a Bad Driver: Alienation to Sensuality in the Anthropology of Automobility  [PDF]
Andrew Dawson
Advances in Anthropology (AA) , 2017, DOI: 10.4236/aa.2017.71001
Abstract: Contemporary automobilities research is characterised by a fundamental paradox-recognition of driving as a sensate experience alongside a tendency to emphasise the driver’s sensory disengagement from, rather than engagement with the bodily, social and environmental contexts with which s/he interacts. In this article, which builds on previous empirical work I have published, only now in a more theoretical and comparative directions, I undertake three tasks. I locate automobilities researches’ concern with the senses in its broader contexts of substantive enquiry-namely, the “Mobilities Paradigm” and the social scientific study of the “Senses”. I posit the theoretical basis of the representation of sensory disengagement in driving in automobilities research, specifically in post-war Marxian thought and its critique of Capitalist Modernity and concern with alienation. Lastly, I review three anthropological case studies that represent sensory engagement in driving, one from Palestine, one from Turkey and my own from Bosnia and Herzegovina. I go on to suggest that the approach they share, which is indicative of a growing trend towards the anthropological study of automobilities, is valuable in two ways. It is a corrective to the inappropriate representation of sensory disengagement that is a characteristic of most automobilities research. Also, through its ability to convey sensory engagement in driving, I argue that it provides important insights on the contemporary nature of enduring, but now increasingly mobile social phenomena such as, as in these particular cases sectarian enclosure, class segregation, and ethnic-national transition.
Mobile Meat Puppetry? Ruined Infrastructures, Embodiment and Agency in Driving  [PDF]
Andrew Dawson
Advances in Anthropology (AA) , 2018, DOI: 10.4236/aa.2018.81001
Abstract: Contemporary automobilities research is replete with representation of a docile driver body or,as it is sometimes humorously described,a ‘mobile meat puppet’. This emerges, largely from research on automobilitiesin ‘Developed-World’ contexts. Contrastingly, in this article, through ethnography of driving experiences in post-Socialist and post-war Bosnia I explore material grounds for an agential driver. In particular, I consider how the enduring and decaying road infrastructure of Socialist Yugoslavia provides a basis for senses of empowerment in relation to new ethnic-nationalist states that are often experienced as oppressive and controlling.
Youthquake: Neoliberalism and the Ethnicization of Generation  [PDF]
Andrew Dawson
Advances in Anthropology (AA) , 2018, DOI: 10.4236/aa.2018.81002
Abstract: Through an ethnographic case-study of a former coalmining town in England this article explores relationships between neoliberal restructuring and changes in inter-generational relations. I argue that neoliberalism has produced significant inter-generational structural schisms that, in turn have formed the basis of significant inter-generational cultural schisms. Furthermore, I argue that in several ways these bear the qualities of ethnic divisions.
On -manifolds and -surfaces for analysis of the convergence of mesh-based approximation
Kevin Scully
International Journal of Mathematics and Mathematical Sciences , 2005, DOI: 10.1155/ijmms.2005.3291
Abstract: To categorize the convergence properties of mesh-based approximations to manifolds and surfaces, this paper defines these approximations as “Wk,p-manifolds” and “Wk,p-surfaces.” In particular, this paper examines the importance of these classifications in the convergence in L1-norm of interpolants, built on the approximate manifold or surface, of functions defined on the approximated manifold or surface. To provide context, the applicability of an interpolation framework established by Nédélec involving the convergence of metric determinants is examined. An extension of Nédélec's framework to Wk,p-surfaces is presented.
Page 1 /4397
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.