Creative high school dropouts\u27 experiences of learning : a phenomenological study

This study examined descriptions of learning experiences and the meaning that learning has for 11 creative high school dropouts who had just completed a one-on-one computer assisted multi-media learning experience. For these individuals learning is an active experience full of challenge and rich complexity which is grounded in resilient self reliance. Personal experience is regarded as the most desired and effective way of learning by these individuals.The 11 creative high school dropouts were selected from a population of120 high school dropouts who were enrolled in GED or similar classes at five research sites in 3 East Tennessee counties. For selection purposes assessments of creativity and perceptual modality learning style were administered to ail 120 high school dropouts, and from these, 11 were chosen for participation in a computer assisted multi-media learning experience and in depth,phenomenological interviews based on 3 criteria. The 3 criteria were that the individual had: (a) Scored at the 84th National Percentile or above on the Torrance Tests of Creative Thinking. Figural Form A., (b) exhibited strengths in perceptual modality learning styles not rewarded in traditional school settings,based on scores obtained from the Multi-Modal Paired Associates LearningTest - Revised, and (c) volunteered to be interviewed.The rich interview protocols were analyzed for meaning units and emergent themes by the researcher and a phenomenological research group.Themes are presented in three categories using the actual wording of the 11co-participants. Categories are: (a) “How I learn”, (b) “Why I learn”, and(c). “What learning is to me”.The “How I learn” category includes descriptions of conditions and processes present during optimal learning; desired personal, social, and environmental resources; and feelings during learning. The “Why I learn”category describes the creative individual’s motivation for learning and includes learning in order to understand yourself and your place in the world; todo, make, or survive; and to care for, or understand, others. “What learning is to me” describes the meaning that learning has for these co-participants and was described succinctly by one co-participant, “ Learning is making the best of use of my instincts and experiences to understand myself and others, and to succeed in the world.

Bridging the gap between theory and practice in climate change vulnerability assessments for remote Indigenous communities in northern Australia

This paper considers the Australian federal government’s approach to climate adaptation policy for remote northern Indigenous communities through the close examination of a seminal Scoping Study. This approach is taken to illustrate the lag between adaptation theory and practice, and to highlight important considerations to enable the development of a just and effective policy. The analysis suggests that policy in this area would benefit from the further consideration of three factors, namely the role of uncertainty in climate policy, the need for meaningful consultation with communities, and the benefit of integrating contextual and bottom-up assessment of vulnerability with decision-making in an iterative manner. The paper concludes by suggesting that the current approach to vulnerability assessment is insufficiently nuanced to allow an adequate appreciation of factors that influence social vulnerability in remote communities, and consequently, policy developed from it is likely to be ineffective

Origin and stability of the dipolar response in a family of tetragonal tungsten bronze relaxors

A new family of relaxor dielectrics with the tetragonal tungsten bronze structure (nominal composition Ba6M3+Nb9O30, M3+ = Ga, Sc or In) were studied using dielectric spectroscopy to probe the dynamic dipole response and correlate this with the crystal structure as determined from powder neutron diffraction. Independent analyses of real and imaginary parts of the complex dielectric function were used to determine characteristic temperature parameters, TVF, and TUDR, respectively. In each composition both these temperatures correlated with the temperature of maximum crystallographic strain, Tc/a determined from diffraction data. The overall behaviour is consistent with dipole freezing and the data indicate that the dipole stability increases with increasing M3+ cation size as a result of increased tetragonality of the unit cell. Crystallographic data suggests that these materials are uniaxial relaxors with the dipole moment predominantly restricted to the B1 cation site in the structure. Possible origins of the relaxor behaviour are discussed.Comment: Main article 32 pages, 8 figures; Supplementary data 24 pages, 4 figure

Towards novel multiferroic and magnetoelectric materials: dipole stability in tetragonal tungsten bronzes

authors thank the Engineering and Physical Science Research Council for funding (grant no. EP/F004133/1).We discuss the strategy for development of novel functional materials with the tetragonal tungsten bronze structure. From the starting composition Ba6GaNb9O30, the effect of A- and B-site substitutions on the dielectric properties is used to develop an understanding of the origin and stability of the dipolar response in these compounds. Both tetragonal strain induced by large B-site cations and local strain variations created by isovalent A-site substitutions enhance dipole stability but result in a dilute, weakly correlated dipolar response and canonical relaxor behaviour. Decreasing cation size at the perovskite A2-site increases the dipolar displacements in the surrounding octahedra, but insufficiently to result in dipole ordering. Mechanisms introducing small A-site lanthanide cations and incorporation of A-site vacancies to induce ferroelectricity and magnetism are presented.PostprintPeer reviewe

The reduced genome of the parasitic microsporidian Enterocytozoon bieneusi lacks genes for core carbon metabolism

© The Authors, 2010. This article is distributed under the terms of the Creative Commons Attribution-Noncommercial 2.5 License. The definitive version was published in Genome Biology and Evolution 2 (2010): 304, doi:10.1093/gbe/evq022.Reduction of various biological processes is a hallmark of the parasitic lifestyle. Generally, the more intimate the association between parasites and hosts the stronger the parasite relies on its host's physiology for survival and reproduction. However, some systems have been held to be indispensable, for example, the core pathways of carbon metabolism that produce energy from sugars. Even the most hardened anaerobes that lack oxidative phosphorylation and the tricarboxylic acid cycle have retained glycolysis and some downstream means to generate ATP. Here we describe the deep-coverage genome resequencing of the pathogenic microsporidiian, Enterocytozoon bieneusi, which shows that this parasite has crossed this line and abandoned complete pathways for the most basic carbon metabolism. Comparing two genome sequence surveys of E. bieneusi to genomic data from four other microsporidia reveals a normal complement of 353 genes representing 30 functional pathways in E. bieneusi, except that only 2 out of 21 genes collectively involved in glycolysis, pentose phosphate, and trehalose metabolism are present. Similarly, no genes encoding proteins involved in the processing of spliceosomal introns were found. Altogether, E. bieneusi appears to have no fully functional pathway to generate ATP from glucose. Therefore, this intracellular parasite relies on transporters to import ATP from its host.This work was supported by grants from the Canadian Institutes for Health Research (MOP-84265), the National Institutes of Health (NIH AI31788, R21 AI52792, and R21 AI064118), and the National Science Foundation (MCB- 0135272). N.C. is a Scholar of the Canadian Institute for Advanced Research and is supported by a fellowship from the Swiss National Science Foundation (NSF) (PA00P3- 124166). D.E. is supported by the Swiss NSF. P.J.K. is a Fellow of the Canadian Institute for Advanced Research and a Senior Scholar of the Michael Smith Foundation for Health Research

Development of a Novel Echocardiography Ramp Test for Speed Optimization and Diagnosis of Device Thrombosis in Continuous-Flow Left Ventricular Assist Devices The Columbia Ramp Study

ObjectivesThis study sought to develop a novel approach to optimizing continuous-flow left ventricular assist device (CF-LVAD) function and diagnosing device malfunctions.BackgroundIn CF-LVAD patients, the dynamic interaction of device speed, left and right ventricular decompression, and valve function can be assessed during an echocardiography-monitored speed ramp test.MethodsWe devised a unique ramp test protocol to be routinely used at the time of discharge for speed optimization and/or if device malfunction was suspected. The patient's left ventricular end-diastolic dimension, frequency of aortic valve opening, valvular insufficiency, blood pressure, and CF-LVAD parameters were recorded in increments of 400 rpm from 8,000 rpm to 12,000 rpm. The results of the speed designations were plotted, and linear function slopes for left ventricular end-diastolic dimension, pulsatility index, and power were calculated.ResultsFifty-two ramp tests for 39 patients were prospectively collected and analyzed. Twenty-eight ramp tests were performed for speed optimization, and speed was changed in 17 (61%) with a mean absolute value adjustment of 424 ± 211 rpm. Seventeen patients had ramp tests performed for suspected device thrombosis, and 10 tests were suspicious for device thrombosis; these patients were then treated with intensified anticoagulation and/or device exchange/emergent transplantation. Device thrombosis was confirmed in 8 of 10 cases at the time of emergent device exchange or transplantation. All patients with device thrombosis, but none of the remaining patients had a left ventricular end-diastolic dimension slope >−0.16.ConclusionsRamp tests facilitate optimal speed changes and device malfunction detection and may be used to monitor the effects of therapeutic interventions and need for surgical intervention in CF-LVAD patients

DHODH modulates transcriptional elongation in the neural crest and melanoma

Melanoma is a tumour of transformed melanocytes, which are originally derived from the embryonic neural crest. It is unknown to what extent the programs that regulate neural crest development interact with mutations in the BRAF oncogene, which is the most commonly mutated gene in human melanoma1. We have used zebrafish embryos to identify the initiating transcriptional events that occur on activation of human BRAF(V600E) (which encodes an amino acid substitution mutant of BRAF) in the neural crest lineage. Zebrafish embryos that are transgenic for mitfa:BRAF(V600E) and lack p53 (also known as tp53) have a gene signature that is enriched for markers of multipotent neural crest cells, and neural crest progenitors from these embryos fail to terminally differentiate. To determine whether these early transcriptional events are important for melanoma pathogenesis, we performed a chemical genetic screen to identify small-molecule suppressors of the neural crest lineage, which were then tested for their effects on melanoma. One class of compound, inhibitors of dihydroorotate dehydrogenase (DHODH), for example leflunomide, led to an almost complete abrogation of neural crest development in zebrafish and to a reduction in the self-renewal of mammalian neural crest stem cells. Leflunomide exerts these effects by inhibiting the transcriptional elongation of genes that are required for neural crest development and melanoma growth. When used alone or in combination with a specific inhibitor of the BRAF(V600E) oncogene, DHODH inhibition led to a marked decrease in melanoma growth both in vitro and in mouse xenograft studies. Taken together, these studies highlight developmental pathways in neural crest cells that have a direct bearing on melanoma formation