3,114 research outputs found

    Advising From a Constructive Developmental Perspective

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    Advisors can enhance development by, first, identifying student\u27s meaning-making assumptions and, second, challenging those assumptions while offering support as students struggle to increase the complexity of meaning making. Constructive developmental theory is offered as a useful framework from which to encourage greater student ownership of the educational planning process. Methods of assessing and enhancing development are suggested. Two cases that depict advising from the constructive developmental perspective are offered

    Double precision trajectory program /DPTRAJ 2.2C/

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    Four part program computes trajectory of space probe moving in solar system and subject to variety of forces

    Multi-scale integrated evaluation of the sustainability of large-scale use of alternative feeds in salmon aquaculture

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    The steady increase in production volume of salmon aquaculture has sharpened concerns about its sustainability. In particular the production of salmon feed is a reason for concern given its reliance on scarce natural resources, such as wild fish captures. Multi-scale integrated analysis is put forward as a tool to anticipate the environmental and socio-economic impacts of large-scale implementation of alternative salmon feeds, considering both plant and insect sources as potential replacements of fish meal and fish oil. The proposed accounting framework, based on relational analysis across hierarchical levels, describes the patterns of required inputs using biophysical and economic variables. It also considers the inputs used by external systems for the production of imported feed, thus providing a coherent assessment of the sustainability of the production system in terms of feasibility, viability, and desirability. The analytical tool-kit is illustrated in conceptual terms and then applied to the Norwegian salmon aquaculture, both in diagnostic (describing the actual situation) and anticipatory mode (examining feed scenarios). Results are used in an exercise of quantitative story-telling to check the quality of the narratives currently shaping policy discussions on aquaculture. Quantitative story-telling is a heuristic approach aimed at checking the robustness of knowledge claims in face of uncertainty. It is concluded that rearing insects in the salmon feed production chain enlarges the option space of feed sources by opening up the possibility of using locally-produced seaweed and organic waste, but also raises the level of uncertainty with regard to the possible insurgence of negative side effects.publishedVersio

    Changing of flight phenology and ecotype expansion of the European corn borer (Ostrinia nubilalis Hbn.) in Hungary Part

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    The studies aimed to acquire the widest possible information on the annual flight in Hungary of the European corn borer (ECB), Ostrinia nubilalis Hübner (Lepidoptera: Pyralidae). The investigations used biomathematical (Part 1) and graphical (Part 2) evaluation to document changes in the individual population number.The study was conducted in Hungary using ECB moth capture records from the Plant Protection Information System black light trap system (1991–2004). We have drawn conclusions on the appearance of annual flights and the tendency of alterations in flight direction by means of light trap results in four different areas in Hungary. We calculated the flight peak quotients, the individual population numbers of the second flight peak, the distinctions of individual numbers of two flight peaks in this part.As previously published, alterations in flight direction of ECB flights began at different times in Hungary. In the current study, a gradual disappearance of the univoltine ecotype and gradual appearance of the bivoltine ecotype ECB in Hungary is confirmed by the data obtained between 1991–2004. Flight peak quotients and data concerning the second flight peak have confirmed change this process, too: the appearance of a second flight peak in Northwestern Hungary from 1995–1996 (FP = 1.27), the more significant appearance of flights in August in Western Hungary (FP = 1.05) and Northeastern Hungary (FP = 1.45), and a three and four times more individual number of the second flight peak in Southeastern Hungary (FP = 3.44). Flight peak quotients, individual population numbers of the second flight peak, the tendency towards a difference in population number of the two peaks, and size of increase of these values demonstrates the southeastern-northwestern presence of the bivoltine ecotype in Hungary

    Pain in patients with dementia: A review of pain assessment and treatment challenges

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    Pain represents a major treatment challenge in older people with dementia. The majority of healthy older people experience regular pain and around 50% take regular analgesics. Pain is likely to be equally prevalent in people with dementia, yet only a small minority are prescribed regular analgesics. This is a key issue since recent work has provided evidence that untreated pain may be a major contributor to reduced quality of life and increases the likelihood of emergence of behavioural and psychological symptoms such as agitation. Better assessment and treatment of pain may therefore substantially improve outcomes for people with dementia. In this context, we reviewed the literature and summarised the best available evidence regarding the frequency of pain and pain diagnosis in patients with dementia based on pain assessment and treatment recommendations for these individuals. Hardly any randomized, controlled studies of pain treatment efficacy in patients with dementia are available, with the consequence that most pain treatment recommendations are not based on the highest level of evidence

    The Initial Mass Function of Low-Mass Stars and Brown Dwarfs in Young Clusters

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    We have obtained images of the Trapezium Cluster (140" x 140"; 0.3 pc x 0.3 pc) with the Hubble Space Telescope Near-Infrared Camera and Multi-Object Spectrometer (NICMOS). Combining these data with new ground-based K-band spectra (R=800) and existing spectral types and photometry and the models of D'Antona & Mazzitelli, we find that the distributions of ages of comparable samples of stars in the Trapezium, rho Oph, and IC 348 indicate median ages of \~0.4 Myr for the first two regions and ~1-2 Myr for the latter. The low-mass IMFs in these sites of clustered star formation are similar over a wide range of stellar densities and other environmental conditions. With current data, we cannot rule out modest variations in the substellar mass functions among these clusters. We then make the best estimate of the true form of the IMF in the Trapezium by using the evolutionary models of Baraffe et al. and an empirically adjusted temperature scale and compare this mass function to recent results for the Pleiades and the field. All of these data are consistent with an IMF that is flat or rises slowly from the substellar regime to about 0.6 Msun, and then rolls over into a power law that continues from about 1 Msun to higher masses with a slope similar to or somewhat larger than the Salpeter value of 1.35. For the Trapezium, this behavior holds from our completeness limit of ~0.02 Msun and probably, after a modest completeness correction, even from 0.01-0.02 Msun. These data include ~50 likely brown dwarfs. We test the predictions of theories of the IMF against various properties of the observed IMF.Comment: 34 pages, 13 figures, for color image see http://cfa-www.harvard.edu/~kluhman/trap/colorimage.jp

    Electron Spin Dynamics and Hyperfine Interactions in Fe/Al_0.1Ga_0.9As/GaAs Spin Injection Heterostructures

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    We have studied hyperfine interactions between spin-polarized electrons and lattice nuclei in Al_0.1Ga_0.9As/GaAs quantum well (QW) heterostructures. The spin-polarized electrons are electrically injected into the semiconductor heterostructure from a metallic ferromagnet across a Schottky tunnel barrier. The spin-polarized electron current dynamically polarizes the nuclei in the QW, and the polarized nuclei in turn alter the electron spin dynamics. The steady-state electron spin is detected via the circular polarization of the emitted electroluminescence. The nuclear polarization and electron spin dynamics are accurately modeled using the formalism of optical orientation in GaAs. The nuclear spin polarization in the QW is found to depend strongly on the electron spin polarization in the QW, but only weakly on the electron density in the QW. We are able to observe nuclear magnetic resonance (NMR) at low applied magnetic fields on the order of a few hundred Oe by electrically modulating the spin injected into the QW. The electrically driven NMR demonstrates explicitly the existence of a Knight field felt by the nuclei due to the electron spin.Comment: 19 Figures - submitted to PR

    Particle transport in density gradient driven TE mode turbulence

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    The turbulent transport of main ion and trace impurities in a tokamak device in the presence of steep electron density gradients has been studied. The parameters are chosen for trapped electron (TE) mode turbulence, driven primarily by steep electron density gradients relevant to H-mode physics, but with a transition to temperature gradient driven turbulence as the density gradient flattens. Results obtained through non-linear (NL) and quasilinear (QL) gyrokinetic simulations using the GENE code are compared with results obtained from a fluid model. Main ion and impurity transport is studied by examining the balance of convective and diffusive transport, as quantified by the density gradient corresponding to zero particle flux (peaking factor). Scalings are obtained for the impurity peaking with the background electron density gradient and the impurity charge number. It is shown that the impurity peaking factor is weakly dependent on impurity charge and significantly smaller than the driving electron density gradient.Comment: 11 pages, 6 figures. Submitted to Nuclear Fusion SP
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