2,412 research outputs found

    Preparing Tomorrow\u27s Classroom Leaders: Challenges for Christian Higher Education

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    Christian college teacher education program faculties face the challenge of employing a Christian epistemology that includes a pedagogy that embraces today’s learners. The authors seek to communicate the foundations of modernism and postmodernism and their impact on the epistemology and pedagogies employed in university classrooms. How the postmodern thinking claims have influenced the lives of Christian students will also be examined. The paper concludes with a discussion of the challenges for Christian teacher education faculties

    Formation of magnetic minerals at hydrocarbon-generation conditions

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    In this paper, we report the pyrolysis and formation of magnetic minerals in three source rock samples from the Wessex Basin in Dorset, southern England. The experimental conditions in the laboratory recreated the catagenesis environment of oil source rocks. Magnetic analysis of both the heated and the unheated samples at room temperature and at very low-temperatures (5 K), coupled with transmission electron-microscopy imaging and X-ray analysis, revealed the formation of nanometre-sized (<10 nm), magnetic particles that varied across the rock samples analysed, but more importantly across the pyrolysis temperature range. Magnetic measurements demonstrated the formation of these magnetic minerals peaked at 250 °C for all rock samples and then decreased at 300 °C before rising again at 320 °C. The newly formed magnetic minerals are suggested to be primarily pyrrhotite, though magnetite and greigite are also thought to be present. The sizes of the magnetic minerals formed suggest a propensity to migrate together with oil potentially explaining the magnetic anomalies observed above and within oil fields

    More on the Narrowing of Impact Broadened Radio Recombination Lines at High Principal Quantum Number

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    Recently Alexander and Gulyaev have suggested that the apparent decrease in impact broadening of radio recombination lines seen at high principal quantum number n may be a product of the data reduction process, possibly resulting from the presence of noise on the telescope spectra that is not present on the calculated comparison spectra. This is an interesting proposal. However, there are serious problems with their analysis that need to be pointed out. Perhaps the most important of these is the fact that for principal quantum numbers below n = 200, where the widths are not in question, their processed generated profile widths do not fit the widths of the processed lines obtained at the telescope. After processing, the halfwidths of the generated and telescope profiles must agree below n = 200 if we are to believe that the processed generated linewidths above n = 200 are meaningful. Theirs do not. Furthermore, we find that after applying the linewidth reduction factors found by Alexander and Gulyaev for their noise added profiles to our generated profiles to simulate their noise adding effect, the processed widths we obtain still do not come close to explaining the narrowing seen in the telescope lines for n values in the range 200 < n < 250. It is concluded that what is needed to solve this mystery is a completely new approach using a different observing technique instead of simply a further manipulation of the frequency-switched data.Comment: Six pages with 4 figures. Accepted for publication in Astrophysics and Space Scienc

    Sensing Subjective Well-being from Social Media

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    Subjective Well-being(SWB), which refers to how people experience the quality of their lives, is of great use to public policy-makers as well as economic, sociological research, etc. Traditionally, the measurement of SWB relies on time-consuming and costly self-report questionnaires. Nowadays, people are motivated to share their experiences and feelings on social media, so we propose to sense SWB from the vast user generated data on social media. By utilizing 1785 users' social media data with SWB labels, we train machine learning models that are able to "sense" individual SWB from users' social media. Our model, which attains the state-by-art prediction accuracy, can then be used to identify SWB of large population of social media users in time with very low cost.Comment: 12 pages, 1 figures, 2 tables, 10th International Conference, AMT 2014, Warsaw, Poland, August 11-14, 2014. Proceeding

    Efficacy of pimobendan in the prevention of congestive heart failure or sudden death in doberman pinschers with preclinical dilated cardiomyopathy (the PROTECT study)

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    &lt;p&gt;Background: The benefit of pimobendan in delaying the progression of preclinical dilated cardiomyopathy (DCM) in Dobermans is not reported.&lt;/p&gt; &lt;p&gt;Hypothesis: That chronic oral administration of pimobendan to Dobermans with preclinical DCM will delay the onset of CHF or sudden death and improve survival.&lt;/p&gt; &lt;p&gt;Animals: Seventy-six client-owned Dobermans recruited at 10 centers in the UK and North America.&lt;/p&gt; &lt;p&gt;Methods: The trial was a randomized, blinded, placebo-controlled, parallel group multicenter study. Dogs were allocated in a 1:1 ratio to receive pimobendan (Vetmedin capsules) or visually identical placebo.&lt;/p&gt; &lt;p&gt;The composite primary endpoint was prospectively defined as either onset of CHF or sudden death. Time to death from all causes was a secondary endpoint.&lt;/p&gt; &lt;p&gt;Results: The proportion of dogs reaching the primary endpoint was not significantly different between groups (P = .1). The median time to the primary endpoint (onset of CHF or sudden death) was significantly longer in the pimobendan (718 days, IQR 441–1152 days) versus the placebo group (441 days, IQR 151–641 days) (log-rank P = 0.0088). The median survival time was significantly longer in the pimobendan (623 days, IQR 491–1531 days) versus the placebo group (466 days, IQR 236–710 days) (log-rank P = .034).&lt;/p&gt; &lt;p&gt;Conclusion and Clinical Importance: The administration of pimobendan to Dobermans with preclinical DCM prolongs the time to the onset of clinical signs and extends survival. Treatment of dogs in the preclinical phase of this common cardiovascular disorder with pimobendan can lead to improved outcome.&lt;/p&gt

    Transfinite thin plate spline interpolation

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    Duchon's method of thin plate splines defines a polyharmonic interpolant to scattered data values as the minimizer of a certain integral functional. For transfinite interpolation, i.e. interpolation of continuous data prescribed on curves or hypersurfaces, Kounchev has developed the method of polysplines, which are piecewise polyharmonic functions of fixed smoothness across the given hypersurfaces and satisfy some boundary conditions. Recently, Bejancu has introduced boundary conditions of Beppo Levi type to construct a semi-cardinal model for polyspline interpolation to data on an infinite set of parallel hyperplanes. The present paper proves that, for periodic data on a finite set of parallel hyperplanes, the polyspline interpolant satisfying Beppo Levi boundary conditions is in fact a thin plate spline, i.e. it minimizes a Duchon type functional

    Determination of heat flows inside turbochargers by means of a one dimensional lumped model

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    In the present paper, a methodology to calculate the heat fluxes inside a turbocharger from diesel passenger car is presented. The heat transfer phenomenon is solved by using a one dimensional lumped model that takes into account both the heat fluxes between the different turbocharger elements, as well as the heat fluxes between the working fluids and the turbocharger elements. This heat transfer study is supported by the high temperature differences between the working fluids passing through a typical diesel turbocharger. These flows are the hot exhaust gases coming from the diesel engine exhaust passing through the turbine, the fresh air taken by the compressor, and the lubrication oil passing through the housing. The model has been updated to be used with a new generation of passenger car turbochargers using an extra element in the heat transfer phenomenon that is the water cooling circuit. This procedure allows separating the aerodynamic from the heat transfer effects, permitting to study the behavior of compressor and turbine in a separated way. (C) 2011 Elsevier Ltd. All rights reserved.Olmeda González, PC.; Dolz Ruiz, V.; Arnau Martínez, FJ.; Reyes Belmonte, MA. (2013). Determination of heat flows inside turbochargers by means of a one dimensional lumped model. Mathematical and Computer Modelling. 57(7-8):1847-1852. doi:10.1016/j.mcm.2011.11.078S18471852577-

    Synchronously pumped mid-infrared CdSe optical parametric oscillator

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    Synchronously pumped optical parametric oscillators (SPOPOs) are efficient sources of tunable ultrashort pulses, with low threshold average power requirements, since gain is defined by peak power. An attractive material for such devices is cadmium selenide (CdSe) due to its high nonlinearity (d(31) = 18 pm/V), wide transparency range (0.75-25 µm) and high optical quality. Previous efforts involving CdSe in OPOs have been restricted to angle-tuning, and using Q-switched pump sources. We present here the first continuous-wave, mode-locked SPOPO based on non-critically phase-matched (NCPM) CdSe, with agile tuning of the idler over the range 9.1-9.7 µm, the longest wavelength achieved using a SPOPO to date. Pump-wavelength-tuning over a wide range (necessary for the NCPM arrangement) was provided by the signal output of a periodically poled lithium niobate (PPLN) SPOPO, operating close to degeneracy using a single PPLN grating period. The use of a diffraction grating to tune the signal of the PPLN SPOPO was a key factor in obtaining clean, single-frequency pump conditions, with tuning achieved by simple grating rotation

    Biofumigation for the management of Fusarium graminearum in a wheat-maize rotation

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    Fusarium graminearum is the most important causal agent of head blight in wheat, and stalk and ear rot in maize. A field experiment was conducted to investigate the effect of incorporation of Brassicaceae cover crops on Fusarium graminearum in a wheat-maize rotation. Five species belonging to Brassicaceae (Brassica juncea, Eruca sativa, Raphanus sativus, B. carinata, B. oleracea var. caulorapa L.) were used in the field experiment to investigate their potential to suppress F. graminearum inoculum in soil, disease incidence in maize and to reduce subsequent mycotoxin contamination in maize. Brassica juncea was found to contain the highest glucosinolate concentration in shoots (31 µmol g−1). Severity of ear rot and stalk rot in maize was not significantly reduced in the amended plots. Incorporation of R. sativus ‘Terranova’ significantly decreased the amount of F. graminearum DNA by 58% compared with the cultivated fallow treatment, however the DNA concentration was not significantly different to fallow uncultivated. Fusarium graminearum DNA and deoxynivalenol in maize was 50% lower after incorporation of B. oleracea var. caulorapa L. compared to after fallow treatment but the difference was not significant. The brassica crops used in the present field experiment were not effective in suppressing F. graminearum, therefore further studies to optimise the current approach are recommended
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