1,328 research outputs found

    Implementation of UAVs in Wilderness Search and Rescue

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    Undergraduate Textual or Investigativ

    Transport properties of thulium single crystals

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    How Principals Learn to Be Technology Leaders: A Critical Incident Qualitative Study

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    The purpose of this study is to investigate how principals learn to be technology leaders by examining the different ways principals learn and exploring the skills principals perceive are needed. The study also examines what principals do differently to develop a successful technology integration (or not). Using the critical incident method, 18 principals were interviewed from across the state. The in-depth interviews were transcribed for all participants interviewed and then analyzed using coding and theming with the aid of memos. From this, three predominant categories emerged: learning, skills, and challenges. The findings from the study reveal that principals learn primarily through three different methods, with the most important one being professional development. Professional development is through face-to-face or online learning using their professional learning networks to guide them in developing the needed knowledge. The principals also learn by talking with others and learning on their own. The three areas the principals use to learn are their experiences, initiative, and reflection, which align with the common areas found in adult learning. The skills principals use to be technology leaders were found to be consistent with the skills described in the ISTE framework for educational leaders. Furthermore, principals face certain challenges while trying to be technology leaders and to integrate technology. Lastly, principals distinguished what they did differently for a technology integration to be successful (or not). The study concludes that principals can learn to be technology leaders, by using the right tools and by developing the necessary skills to be successful. The findings revealed the need for professional development on technological tools to be purposeful and fit the different needs of principals and teachers. For a technology integration to be successful, the professional development should not be a one-time meeting, but ongoing in order to provide continuous support and guidance for principals and teachers. Also, districts should make principals aware of the skills listed by ISTE for principals to be technology leaders. For some, knowing the skills needed will help them transform into technology leaders, allowing them to guide teachers to understand what they need to do in the classroom to be successful

    Disturbing Pasts: Memories, Controversies and Creativity

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    This themed issue of the Open Arts Journal, ‘Disturbing pasts: Memories, controversies and creativity’, brings together a range of artists, curators, policy-makers and academics from around the world, who explore creative engagements with controversial and traumatic pasts in art practice, curating and museums. The material is presented in three parts: ‘Difficult Pasts and Public Space’ (writings on historical issues and museums), ‘Visual Investigations’ (artists’ statements and criticism), and ‘Collaborations’ (visual analysis and artist-scholar pairings of writings and original artworks). This collection was developed through a two-year international research project led by Leon Wainwright, which involved three consortia of researchers from universities throughout Europe, and focused on a major public event at the Museum of Ethnology Vienna/Weltmuseum, Wien (November 2011). The project is funded by HERA (Humanities in the European Research Area, the European Science Foundation)

    Chapter Plant Name Resources

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    Plant names are the key to communicating and managing information about plants. This paper considers how providers of high quality technical plant name information can better meet the requirements non-botanical audiences who also rely on plant names for elements of their work. The International Plant Name Index, World Checklist of Selected Plant Families and The Plant List are used as examples to illustrate the strengths and weaknesses of plant name resources from a non-expert user’s perspective. The above resources can be thought of as botanists pushing data at audiences. Without closer engagement with users, however, there is a limit to their relevance and impact. The need to cover common names is a frequent criticism of existing resources. The Medicinal Plant Names Services (MPNS, www.kew.org/mpns) is an example of how plant name resources can be adapted to better address the needs of a non-botanical audience. Some of the major challenges are outlined and solutions suggested

    Transcatheter Aortic Valve Implantation in Dialysis Patients

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    Background/Aims: Transcatheter aortic valve implantation (TAVI) has emerged as a new therapeutic option for high-risk patients. However, dialysis patients were excluded from all previous studies. The aim of this study is to compare the outcomes of TAVI for dialysis patients with those for patients with chronic kidney disease (CKD) stages 3 and 4 and to compare TAVI with open surgery in dialysis patients. Methods: Part I: comparison of 10 patients on chronic hemodialysis with 116 patients with non-dialysis-dependent CKD undergoing TAVI. Part II: comparison of transcatheter (n = 15) with open surgical (n = 24) aortic valve replacement in dialysis patients. Results: Part I: dialysis patients were significantly younger (72.3 vs. 82.0 years; p < 0.01). Hospital stay was significantly longer in dialysis patients (21.8 vs. 12.1 days; p = 0.01). Overall 30-day mortality was 3.17%, with no deaths among dialysis patients. Six-month survival rates were similar (log-rank p = 0.935). Part II: patient age was comparable (66.5 vs. 69.5 years; p = 0.42). Patients in the surgical group tended to stay longer in hospital than TAVI patients (29.5 vs. 22.5 days; p = 0.35). Conclusion: TAVI is a safe procedure in patients on chronic hemodialysis. Until new data become available, we find no compelling reason to refuse these patients TAVI. Copyright (C) 2012 S. Karger AG, Base

    His/Met heme ligation in the PioA outer membrane cytochrome enabling light-driven extracellular electron transfer by Rhodopseudomonas palustris TIE-1

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    A growing number of bacterial species are known to move electrons across their cell envelopes. Naturally this occurs in support of energy conservation and carbon-fixation. For biotechnology it allows electron exchange between bacteria and electrodes in microbial fuel cells and during microbial electrosynthesis. In this context Rhodopseudomonas palustris TIE-1 is of much interest. These bacteria respond to light by taking electrons from their external environment, including electrodes, to drive CO2-fixation. The PioA cytochrome, that spans the bacterial outer membrane, is essential for this electron transfer and yet little is known about its structure and electron transfer properties. Here we reveal the ten c-type hemes of PioA are redox active across the window +250 to -400 mV versus Standard Hydrogen Electrode and that the hemes with most positive reduction potentials have His/Met and His/H2O ligation. These chemical and redox properties distinguish PioA from the more widely studied family of MtrA outer membrane decaheme cytochromes with ten His/His ligated hemes. We predict a structure for PioA in which the hemes form a chain spanning the longest dimension of the protein, from Heme 1 to Heme 10. Hemes 2, 3 and 7 are identified as those most likely to have His/Met and/or His/H2O ligation. Sequence analysis suggests His/Met ligation of Heme 2 and/or 7 is a defining feature of decaheme PioA homologs from over 30 different bacterial genera. His/Met ligation of Heme 3 appears to be less common and primarily associated with PioA homologs from purple non-sulphur bacteria belonging to the alphaproteobacteria class

    Rural to Urban Migration and Changes in Cardiovascular risk Factors in Tanzania: A Prospective Cohort Study.

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    High levels of rural to urban migration are a feature of most African countries. Our aim was to investigate changes, and their determinants, in cardiovascular risk factors on rural to urban migration in Tanzania. Men and women (15 to 59 years) intending to migrate from Morogoro rural region to Dar es Salaam for at least 6 months were identified. Measurements were made at least one week but no more than one month prior to migration, and 1 to 3 monthly after migration. Outcome measures included body mass index, blood pressure, fasting lipids, and self reported physical activity and diet. One hundred and three men, 106 women, mean age 29 years, were recruited and 132 (63.2%) followed to 12 months. All the figures presented here refer to the difference between baseline and 12 months in these 132 individuals. Vigorous physical activity declined (79.4% to 26.5% in men, 37.8% to 15.6% in women, p < 0.001), and weight increased (2.30 kg men, 2.35 kg women, p < 0.001). Intake of red meat increased, but so did the intake of fresh fruit and vegetables. HDL cholesterol increased in men and women (0.24, 0.25 mmoll-1 respectively, p < 0.001); and in men, not women, total cholesterol increased (0.42 mmoll-1, p = 0.01), and triglycerides fell (0.31 mmoll-1, p = 0.034). Blood pressure appeared to fall in both men and women. For example, in men systolic blood pressure fell by 5.4 mmHg, p = 0.007, and in women by 8.6 mmHg, p = 0.001. The lower level of physical activity and increasing weight will increase the risk of diabetes and cardiovascular disease. However, changes in diet were mixed, and may have contributed to mixed changes in lipid profiles and a lack of rise in blood pressure. A better understanding of the changes occurring on rural to urban migration is needed to guide preventive measures

    HDAC-mediated control of ERK- and PI3K-dependent TGF-β-induced extracellular matrix-regulating genes

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    Histone deacetylases (HDACs) regulate the acetylation of histones in the control of gene expression. Many non-histone proteins are also targeted for acetylation, including TGF-ß signalling pathway components such as Smad2, Smad3 and Smad7. Our studies in mouse C3H10T1/2 fibroblasts suggested that a number of TGF-ß-induced genes that regulate matrix turnover are selectively regulated by HDACs. Blockade of HDAC activity with trichostatin A (TSA) abrogated the induction of a disintegrin and metalloproteinase 12 (Adam12) and tissue inhibitor of metalloproteinases-1 (Timp-1) genes by TGF-ß, whereas plasminogen activator inhibitor-1 (Pai-1) expression was unaffected. Analysis of the activation of cell signalling pathways demonstrated that TGF-ß induced robust ERK and PI3K activation with delayed kinetics compared to the phosphorylation of Smads. The TGF-ß induction of Adam12 and Timp-1 was dependent on such non-Smad signalling pathways and, importantly, HDAC inhibitors completely blocked their activation without affecting Smad signalling. Analysis of TGF-ß-induced Adam12 and Timp-1 expression and ERK/PI3K signalling in the presence of semi-selective HDAC inhibitors valproic acid, MS-275 and apicidin implicated a role for class I HDACs. Furthermore, depletion of HDAC3 by RNA interference significantly down-regulated TGF-ß-induced Adam12 and Timp-1 expression without modulating Pai-1 expression. Correlating with the effect of HDAC inhibitors, depletion of HDAC3 also blocked the activation of ERK and PI3K by TGF-ß. Collectively, these data confirm that HDACs, and in particular HDAC3, are required for activation of the ERK and PI3K signalling pathways by TGF-ß and for the subsequent gene induction dependent on these signalling pathways
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