155 research outputs found

    Teaching Information Literacy to Undergraduate Students: Reflecting on the Past, Present and Future of Library Instruction

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    The need to teach information literacy skills to undergraduate students is often framed as a 21st century concern, but debate over the value and practice of teaching this set of skills can be found as far back as the early 1900’s. This article reviews the history of information literacy instruction in academic libraries from its origins to the present, examines the current state of information literacy instruction in academic libraries, and explores possible future directions that this instruction may take. Looking to the past, present and future shows that while library instruction has evolved, many central concerns remain unanswered

    Two Approaches to Collaborative Information Literacy Instruction at a Small Engineering School

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    Two librarians at a small STEM academic library have partnered with professors to develop and teach chemistry and writing courses. These librarians have successfully worked with professors to serve as an active presence within the classroom. This article describes the challenges of navigating the typical obstacles librarians face when attempting to integrate information literacy into the curriculum, reflects on the benefits of these collaborations, and touches on strategies for implementing similar programs at other institutions. It outlines two distinct approaches to collaborating with professors on credit-bearing information literacy courses, along with the key steps involved in planning and implementing these courses, including generating institutional buy-in, identifying potential collaborators, negotiating workload and responsibilities with collaborators, and planning to sustain courses beyond a single academic year. Suggestions for overcoming obstacles, supplemented by experience-based recommendations, are discussed

    Supersymmetric Singlet Majorons and Cosmology

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    We examine cosmological constraints on the lepton number breaking scale in supersymmetric singlet majoron models. Special attention is drawn to the model dependence arising from the particular choice of a certain majoron extension and a cosmological scenario. We find that the bounds on the symmetry breaking scale can vary substantially. Large values of this scale can be allowed if the decoupling temperature of smajoron and majorino exceeds the reheating temperature of inflation. In the opposite case an upper bound depending on the majoron model can be obtained which, however, is unlikely to be much larger than 101010^{10} GeV.Comment: 14 pages, 2 figures, IC/94/40, SNUTP 94-15, TUM - TH - 164/9

    Post Inflationary Behaviour of String Moduli

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    We analyze the behaviour of moduli fields in string effective models between the end of inflation and reheating. The effective moduli potential during this era is derived for a class of simple models. We argue that this potential significantly stabilizes the modulus at its high energy minimum, if some restrictions on modular weights are met. Two mechanisms to further stabilize the moduli to their low energy minima are discussed explicitly: coinciding minima at a point of enhanced symmetry, and the smooth transition from high to low energy minimum by an effective mass term C^2 H^2. For both cases we present explicit examples, and C^2 is found to be O(10) at most. In addition, we show that during a smooth transition the reduction of the modulus amplitude strongly depends on the shape of the low energy potential.Comment: 22 pages LaTeX with 6 postscript figures included (epsf

    Scale-dependent bias induced by local non-Gaussianity: A comparison to N-body simulations

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    We investigate the effect of primordial non-Gaussianity of the local f_NL type on the auto- and cross-power spectrum of dark matter haloes using simulations of the LCDM cosmology. We perform a series of large N-body simulations of both positive and negative f_NL, spanning the range between 10 and 100. Theoretical models predict a scale-dependent bias correction \Delta b(k,f_NL) that depends on the linear halo bias b(M). We measure the power spectra for a range of halo mass and redshifts covering the relevant range of existing galaxy and quasar populations. We show that auto and cross-correlation analyses of bias are consistent with each other. We find that for low wavenumbers with k<0.03 h/Mpc the theory and the simulations agree well with each other for biased haloes with b(M)>1.5. We show that a scale-independent bias correction improves the comparison between theory and simulations on smaller scales, where the scale-dependent effect rapidly becomes negligible. The current limits on f_NL from Slosar et al. (2008) come mostly from very large scales k<0.01 h/Mpc and, therefore, remain valid. For the halo samples with b(M)<1.5-2 we find that the scale- dependent bias from non-Gaussianity actually exceeds the theoretical predictions. Our results are consistent with the bias correction scaling linearly with f_NL.Comment: 13 pages, 10 figures. (v2): substantial changes. added a physically motivated scale-independent bias correction which improves significantly the agreement with the simulations (v3): matches published versio

    Supersymmetric Dark Matter

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    There is almost universal agreement among astronomers that most of the mass in the Universe and most of the mass in the Galactic halo is dark. Many lines of reasoning suggest that the dark matter consists of some new, as yet undiscovered, weakly-interacting massive particle (WIMP). There is now a vast experimental effort being surmounted to detect WIMPS in the halo. The most promising techniques involve direct detection in low-background laboratory detectors and indirect detection through observation of energetic neutrinos from annihilation of WIMPs that have accumulated in the Sun and/or the Earth. Of the many WIMP candidates, perhaps the best motivated and certainly the most theoretically developed is the neutralino, the lightest superpartner in many supersymmetric theories. We review the minimal supersymmetric extension of the Standard Model and discuss prospects for detection of neutralino dark matter. We review in detail how to calculate the cosmological abundance of the neutralino and the event rates for both direct- and indirect-detection schemes, and we discuss astrophysical and laboratory constraints on supersymmetric models. We isolate and clarify the uncertainties from particle physics, nuclear physics, and astrophysics that enter at each step in the calculation. We briefly review other related dark-matter candidates and detection techniques.Comment: The complete postscript file is available at ftp://ftp.npac.syr.edu/pub/users/jungman/susyreview/susyreview.ps.Z The TeX source and figures (plain TeX; macros included) are at ftp://ftp.npac.syr.edu/pub/users/jungman/susyreview/susyreview.tar.Z Full paper NOT submitted to lanl archive: table of contents only. To appear in Physics Report

    Biological activity of faba beans proanthocyanidins

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    The objective of the experiment was to determine whether small amounts of proanthocyanidins (0.1 and 0.3%) may increase the antioxidative properties of the rat diet without exerting an antinutritional effect. Proanthocyanidins of faba bean seed coats were extracted with a mixture of acetone and water (70:30) and lyophilized. The amount of proanthocyanidins was two- or fourfold higher in the experimental diets as compared to the control diet. The addition of proanthocyanidin extract had no significant effect on the coefficients of digestibility of crude protein, daily nitrogen retention and the coefficient of biological value of diet protein. In the blood serum of rats fed diets supplemented with proanthocyanidin extract, there was a slightly higher content of vitamin E and alanine aminotransferase activity, while the content of vitamin A and aspartate aminotransferase activity were similar to those of the control group. In the contents of the rat gut (caecum), a lower activity of â -glucuronidase was found as compared to the control group, whereas â -galactosidase was unaffected. The addition of proanthocyanidin extract to diet caused a decrease in the malondialdehyde content in the heart, kidneys, erythrocytes and blood plasma of rats. The results obtained indicate that the amount of proanthocyanidins used did not exert any antinutritional effects, but extended the pool of diet antioxidants and beneficially affected the activity of the large bowel microflora
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