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Search Results: 1 - 10 of 198118 matches for " N. Ellefson "
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Inquiry-based training improves teaching effectiveness of biology teaching assistants
P. William Hughes, Michelle R. Ellefson
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0078540
Abstract: Graduate teaching assistants (GTAs) are used extensively as undergraduate science lab instructors at universities, yet they often have having minimal instructional training and little is known about effective training methods. This blind randomized control trial study assessed the impact of two training regimens on GTA teaching effectiveness. GTAs teaching undergraduate biology labs (n = 52) completed five hours of training in either inquiry-based learning pedagogy or general instructional “best practices”. GTA teaching effectiveness was evaluated using: (1) a nine-factor student evaluation of educational quality; (2) a six-factor questionnaire for student learning; and (3) course grades. Ratings from both GTAs and undergraduates indicated that indicated that the inquiry-based learning pedagogy training has a positive effect on GTA teaching effectiveness.
Behavioral Comparisons of Cloned and Non-cloned Pigs
F.C. Gwazdauskas,A.H. Walters,M.L. McGilliard,S.F. Ball,N. Ellefson,S.S. Flesher,L.L. Keyes,W.F. Nicholson,K.S. Rosoff,K.A. Strahsmeier,M.R. Wheeler,I.A. Polejaeva,D.L. Ayares
Journal of Animal and Veterinary Advances , 2012,
Abstract: The goal of this study was to evaluate whether there were differences in behaviors of cloned and non-cloned pigs. The objectives were 1) to evaluate maintenance behaviors; 2) to determine the establishment of dominance; 3) to assess learning; and 4) to appraise farrowing and mothering abilities of cloned and non-cloned gilts. Maintenance behaviors recorded at 15-min intervals over a 12-h period were not different in terms of the frequencies of lying, standing, feeding and rooting between groups (clone vs. non-clone). There was a group by time interaction (P < 0.05) for aggressive encounters, with cloned gilts more active in late morning. With short term paired feeding tests there were no significant effects of group on attempts to eat. Learning ability was evaluated using a problem-solving maze with a feed reward. There were no differences between groups finding the reward. Total litter weight was not affected by numbers of piglets born alive, farrowing score, mothering score, dominance score, or learning score. Average piglet birth weight was affected (P < 0.05) by the number of piglets born, but not by the other independent variables. In general, the behavior of cloned gilts was not different from that of non-cloned gilts.
Conceptual and Empirical Themes regarding the Design of Technology Transfer Programs: A Review of Wood Utilization Research in the United States
Paul V. Ellefson,Michael A. Kilgore,Kenneth E. Skog,Christopher D. Risbrudt
International Journal of Forestry Research , 2011, DOI: 10.1155/2011/516135
Abstract: Transfer of technologies produced by research is critical to innovation within all organizations. The intent of this paper is to take stock of the conceptual underpinnings of technology transfer processes as they relate to wood utilization research and to identify conditions that promote the successful transfer of research results. Conceptually, research utilization can be viewed from multiple perspectives, including the haphazard diffusion of knowledge in response to vague and imprecise demands for information, scanning of multiple information sources by individuals and organizations searching for useful scientific knowledge, engagement of third parties to organize research results and communicate them to potential users, and ongoing and active collaboration between researchers and potential users of research. Empirical evidence suggests that various types of programs can promote technology transfer (venture capital, angel investors, business incubators, extension services, tax incentives, and in-house entities), the fundamental effectiveness of which depends on research results that are scientifically valid and consistent with the information needs of potential users. Furthermore, evidence suggests preference toward programs that are appropriately organized and governed, suitably led and creatively administered, and periodically evaluated in accordance with clear standards of success. 1. Introduction Research programs focused on wood utilization and product development are an important source of innovation required for sustaining the worldwide competitive position of wood-based industries. In 2008, an estimated 400 to 500 wood utilization research projects were implemented by 150 to 200 federal, state, and private organizations in the United States (US). Total investments in publically sponsored projects ranged from $110 to $120 million, while, by some estimates, investments in projects sponsored by private concerns exceeded $2.5 billion in the same year [1]. A subject for more and more conjecture is the extent to which information generated by such investments promotes increases in the productivity and efficiency of manufacturing processes and product development. In all likelihood, such conjecture arises from the ever-growing scarcity of financial and human resources that are available to public and private research organizations generally [2]. The intent of this paper was to take stock of the conceptual underpinnings of technology transfer initiatives generally and (with aid of experienced research program administrators) to identify programmatic
HemaMax?, a Recombinant Human Interleukin-12, Is a Potent Mitigator of Acute Radiation Injury in Mice and Non-Human Primates
Lena A. Basile, Dolph Ellefson, Zoya Gluzman-Poltorak, Katiana Junes-Gill, Vernon Mar, Sarita Mendonca, Joseph D. Miller, Jamie Tom, Alice Trinh, Timothy K. Gallaher
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0030434
Abstract: HemaMax, a recombinant human interleukin-12 (IL-12), is under development to address an unmet medical need for effective treatments against acute radiation syndrome due to radiological terrorism or accident when administered at least 24 hours after radiation exposure. This study investigated pharmacokinetics, pharmacodynamics, and efficacy of m-HemaMax (recombinant murine IL-12), and HemaMax to increase survival after total body irradiation (TBI) in mice and rhesus monkeys, respectively, with no supportive care. In mice, m-HemaMax at an optimal 20 ng/mouse dose significantly increased percent survival and survival time when administered 24 hours after TBI between 8–9 Gy (p<0.05 Pearson's chi-square test). This survival benefit was accompanied by increases in plasma interferon-γ (IFN-γ) and erythropoietin levels, recovery of femoral bone hematopoiesis characterized with the presence of IL-12 receptor β2 subunit–expressing myeloid progenitors, megakaryocytes, and osteoblasts. Mitigation of jejunal radiation damage was also examined. At allometrically equivalent doses, HemaMax showed similar pharmacokinetics in rhesus monkeys compared to m-HemaMax in mice, but more robustly increased plasma IFN-γ levels. HemaMax also increased plasma erythropoietin, IL-15, IL-18, and neopterin levels. At non-human primate doses pharmacologically equivalent to murine doses, HemaMax (100 ng/Kg and 250 ng/Kg) administered at 24 hours after TBI (6.7 Gy/LD50/30) significantly increased percent survival of HemaMax groups compared to vehicle (p<0.05 Pearson's chi-square test). This survival benefit was accompanied by a significantly higher leukocyte (neutrophils and lymphocytes), thrombocyte, and reticulocyte counts during nadir (days 12–14) and significantly less weight loss at day 12 compared to vehicle. These findings indicate successful interspecies dose conversion and provide proof of concept that HemaMax increases survival in irradiated rhesus monkeys by promoting hematopoiesis and recovery of immune functions and possibly gastrointestinal functions, likely through a network of interactions involving dendritic cells, osteoblasts, and soluble factors such as IL-12, IFN-γ, and cytoprotectant erythropoietin.
Neonatal Androgenization Exacerbates Alcohol-Induced Liver Injury in Adult Rats, an Effect Abrogated by Estrogen
Whitney M. Ellefson, Ashley M. Lakner, Alicia Hamilton, Iain H. McKillop, Herbert L. Bonkovsky, Nury M. Steuerwald, Yvette M. Huet, Laura W. Schrum
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0029463
Abstract: Alcoholic liver disease (ALD) affects millions of people worldwide and is a major cause of morbidity and mortality. However, fewer than 10% of heavy drinkers progress to later stages of injury, suggesting other factors in ALD development, including environmental exposures and genetics. Females display greater susceptibility to the early damaging effects of ethanol. Estrogen (E2) and ethanol metabolizing enzymes (cytochrome P450, CYP450) are implicated in sex differences of ALD. Sex steroid hormones are developmentally regulated by the hypothalamic-pituitary-gonadal (HPG) axis, which controls sex-specific cycling of gonadal steroid production and expression of hepatic enzymes. The aim of this study was to determine if early postnatal inhibition of adult cyclic E2 alters ethanol metabolizing enzyme expression contributing to the development of ALD in adulthood. An androgenized rat model was used to inhibit cyclic E2 production. Control females (Ctrl), androgenized females (Andro) and Andro females with E2 implants were administered either an ethanol or isocalorically-matched control Lieber-DeCarli diet for four weeks and liver injury and CYP450 expression assessed. Androgenization exacerbated the deleterious effects of ethanol demonstrated by increased steatosis, lipid peroxidation, profibrotic gene expression and decreased antioxidant defenses compared to Ctrl. Additionally, CYP2E1 expression was down-regulated in Andro animals on both diets. No change was observed in CYP1A2 protein expression. Further, continuous exogenous administration of E2 to Andro in adulthood attenuated these effects, suggesting that E2 has protective effects in the androgenized animal. Therefore, early postnatal inhibition of cyclic E2 modulates development and progression of ALD in adulthood.
High-frequency ultrasound for intraoperative margin assessments in breast conservation surgery: a feasibility study
Timothy E Doyle, Rachel E Factor, Christina L Ellefson, Kristina M Sorensen, Brady J Ambrose, Jeffrey B Goodrich, Vern P Hart, Scott C Jensen, Hemang Patel, Leigh A Neumayer
BMC Cancer , 2011, DOI: 10.1186/1471-2407-11-444
Abstract: Ultrasonic tests were performed on resected margins and other tissues obtained from 17 patients, resulting in 34 specimens that were classified into 15 pathology categories. Pulse-echo and through-transmission measurements were acquired from a total of 57 sites on the specimens using two single-element 50-MHz transducers. Ultrasonic attenuation and sound speed were obtained from time-domain waveforms. The waveforms were further processed with fast Fourier transforms to provide ultrasonic spectra and cepstra. The ultrasonic measurements and pathology types were analyzed for correlations. The specimens were additionally re-classified into five pathology types to determine specificity and sensitivity values.The density of peaks in the ultrasonic spectra, a measure of spectral structure, showed significantly higher values for carcinomas and precancerous pathologies such as atypical ductal hyperplasia than for normal tissue. The slopes of the cepstra for non-malignant pathologies displayed significantly greater values that differentiated them from the normal and malignant tissues. The attenuation coefficients were sensitive to fat necrosis, fibroadenoma, and invasive lobular carcinoma. Specificities and sensitivities for differentiating pathologies from normal tissue were 100% and 86% for lobular carcinomas, 100% and 74% for ductal carcinomas, 80% and 82% for benign pathologies, and 80% and 100% for fat necrosis and adenomas. Specificities and sensitivities were also determined for differentiating each pathology type from the other four using a multivariate analysis. The results yielded specificities and sensitivities of 85% and 86% for lobular carcinomas, 85% and 74% for ductal carcinomas, 100% and 61% for benign pathologies, 84% and 100% for fat necrosis and adenomas, and 98% and 80% for normal tissue.Results from high-frequency ultrasonic measurements of human breast tissue specimens indicate that characteristics in the ultrasonic attenuation, spectra, and cepstra can
Implementation of a Higher Quality dc Power Converter  [PDF]
N. N. Barsoum
Journal of Electromagnetic Analysis and Applications (JEMAA) , 2010, DOI: 10.4236/jemaa.2010.22012
Abstract: Many single and three-phase converters are well developed, and covered up in most of electric markets. It is used in many applications in power systems and machine drives. However, an exact definite output signal from the dc side still not recognized. The waveforms of output voltage and current demonstrate an imperfect dc signal and constitute losses, harmonic distortion, low power factor, and observed some ripples. An approximately perfect rectifier bridge is the aim of this research. Perhaps it gives the ability to identify the parameters of the converter to obtain, as much as possible, a perfect dc signal with less ripple, high power factor and high efficiency. Design is implemented by simulation on Power Simulator PSIM, and practically, a series regulator LM723 is applied to provide regulating output voltage. Comparisons of both simulation and hardware results are made to observe differences and similarities.
Estimation of Sensitivity of the DS/AHP Method While Solving Foresight Problems with Incomplete Data  [PDF]
N. Pankratova, N. Nedashkovskaya
Intelligent Control and Automation (ICA) , 2013, DOI: 10.4236/ica.2013.41011
Abstract:

The paper provides mathematical analysis of sensitivity of different combination rules in the DS/AHP method when an alternative is added to the set of decision alternatives while solving foresight problems. Different cases of rank reversals are defined and two sets of conditions for these cases using the method DS/AHP are considered. Rank reversals are illustrated when the DS/AHP method is used to solve practical problem of critical technologies of energy conservation and power efficiency evaluation in Ukraine. It is shown that the DS/AHP method is not sensitive to exclusion (or addition) of an irrelevant decision alternative from (or to) the set of decision alternatives.

Computation of the Genetic Code: Full Version  [PDF]
N. N. Kozlov
Journal of Computer and Communications (JCC) , 2017, DOI: 10.4236/jcc.2017.510008
Abstract: One of the problems in the development of mathematical theory of the genetic code (summary is presented in [1], the detailed—to [2]) is the problem of the calculation of the genetic code. Similar problem in the world is unknown and could be delivered only in the 21st century. One approach to solving this problem is devoted to this work. For the first time a detailed description of the method of calculation of the genetic code was provided, the idea of which was first published earlier [3]), and the choice of one of the most important sets for the calculation was based on an article [4]. Such a set of amino acid corresponds to a complete set of representation of the plurality of overlapping triple gene belonging to the same DNA strand. A separate issue was the initial point, triggering an iterative search process all codes submitted by the initial data. Mathematical analysis has shown that the said set contains some ambiguities, which have been founded because of our proposed compressed representation of the set. As a result, the developed method of calculation was reduced to two main stages of research, where at the first stage only single-valued domains were used in the calculations. The proposed approach made it possible to significantly reduce the amount of computation at each step in this complex discrete structure.
The Study of the Secrets of the Genetic Code  [PDF]
N. N Kozlov
Journal of Computer and Communications (JCC) , 2018, DOI: 10.4236/jcc.2018.67007
Abstract: The disclosure of many secrets of the genetic code was facilitated by the fact that it was carried out on the basis of mathematical analysis of experimental data: the diversity of genes, their structures and genetic codes. New properties of the genetic code are presented and its most important integral characteristics are established. Two groups of such characteristics were distinguished. The first group refers to the integral characteristics for the areas of DNA, where genes are broken down in pairs and all 5 cases of overlap, allowed by the structure of DNA, were investigated. The second group of characteristics refers to the most extended areas of DNA in which there is no genetic overlap. The interrelation of the established integral characteristics in these groups is shown. As a result, a number of previously unknown effects were discovered. It was possible to establish two functions in which all the over-understood codons in mitochondrial genetic codes (human and other organizations) participate, as well as a significant difference in the integral characteristics of such codes compared to the standard code. Other properties of the structure of the genetic code following from the obtained results are also established. The obtained results allowed us to set and solve one of the new breakthrough problems—the calculation of the genetic code. The full version of the solution to this problem was published in this journal in August 2017.
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