6,312 research outputs found

    Albedo climatology analysis and the determination of fractional cloud cover

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    Monthly and zonally averaged surface cover climatology data are presented which are used to construct monthly and zonally averaged surface albedos. The albedo transformations are then applied to the surface albedos, using solar zenith angles characteristic of the Nimbus 6 satellite local sampling times, to obtain albedos at the top of clear and totally cloud covered atmospheres. These albedos are then combined with measured albedo data to solve for the monthly and zonally averaged fractional cloud cover. The measured albedo data were obtained from the wide field of view channels of the Nimbus 6 Earth Radiation Budget experiment, and consequently the fractional cloud cover results are representative of the local sampling times. These fractional cloud cover results are compared with recent studies. The cloud cover results not only show peaks near the intertropical convergence zone, but the monthly migration of the position of these peaks follows general predictions of atmospheric circulation studies

    Directives and Academics: educational developers, technology and the right support

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    There can be ‘an army of people involved in the development of academics as teachers’ (Ling & CADAC, 2009) and the role of Educational Developers with technological expertise is vital to the uptake and creative use of educational technologies in learning contexts (Oliver, 2005). Even so, technology plays only a part in the teaching and learning experience and must be underpinned with pedagogical wherewithal. At Victoria University (VU) in Melbourne, a new VU Agenda expects the university to be known for educational programmes ‘that maximise opportunities for blended and eLearning’. This discussion examines the support available to staff using technologies for teaching. The discussion covers two examples from different faculties where teaching staff have needed to comply with Faculty or School directives to use particular university-supported technologies (Lectopia and GradeMark). The comments about staff uptake of technologies draw on general themes from evaluations administered in each faculty to gauge the effectiveness of the technologies for teaching and to identify further professional development needs. Unsurprisingly, the findings show that, without intensive and timely support tailored to the specific requirements of academics, without academics having both an understanding of the reason for the mandating of a technology as well as an ability to influence that uptake, academics are likely to find ways to resist authoritarian directives. The danger of encouraging academics’ uptake of educational technologies without broader educational development support to encourage good teaching practices that integrate technology and good curriculum design became clear from the dat

    A partnership approach to developing student capacity to engage and staff capacity to be engaging: opportunities for academic developers

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    Many higher education institutions are adopting learning and teaching approaches that embrace 'students as partners'. This can be met with trepidation by academic staff and students. The purpose of this paper is to demonstrate, through two UK-based institutional case studies, that a partnership approach provides an opportunity for staff and students - where each appreciate the others' perspective and the barriers to learning are reduced. We propose five learning points upon which academic developers might reflect and act in order to get to the very heart of how we might achieve and sustain partnership work. © 2015 Taylor & Francis

    Omega-3 Fatty Acids Improve Recovery, whereas Omega-6 Fatty Acids Worsen Outcome, after Spinal Cord Injury in the Adult Rat

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    Spinal cord injury (SCI) is a cause of major neurological disability, and no satisfactory treatment is currently available. Evidence suggests that polyunsaturated fatty acids (PUFAs) could target some of the pathological mechanisms that underlie damage after SCI. We examined the effects of treatment with PUFAs after lateral spinal cord hemisection in the rat. The ω-3 PUFAs α-linolenic acid and docosahexaenoic acid (DHA) injected 30 min after injury induced significantly improved locomotor performance and neuroprotection, including decreased lesion size and apoptosis and increased neuronal and oligodendrocyte survival. Evidence showing a decrease in RNA/DNA oxidation suggests that the neuroprotective effect of ω-3 PUFAs involved a significant antioxidant function. In contrast, animals treated with arachidonic acid, an ω-6 PUFA, had a significantly worse outcome than controls. We confirmed the neuroprotective effect of ω-3 PUFAs by examining the effects of DHA treatment after spinal cord compression injury. Results indicated that DHA administered 30 min after spinal cord compression not only greatly increased survival of neurons but also resulted in significantly better locomotor performance for up to 6 weeks after injury. This report shows a striking difference in efficacy between the effects of treatment with ω-3 and ω-6 PUFAs on the outcome of SCI, with ω-3 PUFAs being neuroprotective and ω-6 PUFAs having a damaging effect. Given the proven clinical safety of ω-3 PUFAs, our observations show that these PUFAs have significant therapeutic potential in SCI. In contrast, the use of preparations enriched in ω-6 PUFAs after injury could worsen outcome after SCI

    The hidden X-ray breaks in afterglow light curves

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    Gamma-Ray Burst (GRB) afterglow observations in the Swift era have a perceived lack of achromatic jet breaks compared to the BeppoSAX, or pre-Swift era. Specifically, relatively few breaks, consistent with jet breaks, are observed in the X-ray light curves of these bursts. If these breaks are truly missing, it has serious consequences for the interpretation of GRB jet collimation and energy requirements, and the use of GRBs as standard candles. Here we address the issue of X-ray breaks which are possibly 'hidden' and hence the light curves are misinterpreted as being single power-laws. We show how a number of precedents, including GRB 990510 & GRB 060206, exist for such hidden breaks and how, even with the well sampled light curves of the Swift era, these breaks may be left misidentified. We do so by synthesising X-ray light curves and finding general trends via Monte Carlo analysis. Furthermore, in light of these simulations, we discuss how to best identify achromatic breaks in afterglow light curves via multi-wavelength analysis.Comment: 4 pages, contributed talk, submitted to the proceedings of Gamma Ray Bursts 2007, Santa Fe, New Mexico, November 5-9 200

    Energy transfer analysis of Fos-Jun dimerization and DNA binding.

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    Timescale Correlation between Marine Atmospheric Exposure and Accelerated Corrosion Testing - Part 2

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    Evaluation of metals to predict service life of metal-based structures in corrosive environments has long relied on atmospheric exposure test sites. Traditional accelerated corrosion testing relies on mimicking the exposure conditions, often incorporating salt spray and ultraviolet (UV) radiation, and exposing the metal to continuous or cyclic conditions similar to those of the corrosive environment. Their reliability to correlate to atmospheric exposure test results is often a concern when determining the timescale to which the accelerated tests can be related. Accelerated corrosion testing has yet to be universally accepted as a useful tool in predicting the long-term service life of a metal, despite its ability to rapidly induce corrosion. Although visual and mass loss methods of evaluating corrosion are the standard, and their use is crucial, a method that correlates timescales from accelerated testing to atmospheric exposure would be very valuable. This paper presents work that began with the characterization of the atmospheric environment at the Kennedy Space Center (KSC) Beachside Corrosion Test Site. The chemical changes that occur on low carbon steel, during atmospheric and accelerated corrosion conditions, were investigated using surface chemistry analytical methods. The corrosion rates and behaviors of panels subjected to long-term and accelerated corrosion conditions, involving neutral salt fog and alternating seawater spray, were compared to identify possible timescale correlations between accelerated and long-term corrosion performance. The results, as well as preliminary findings on the correlation investigation, are presented

    Electrophysiological correlates of high-level perception during spatial navigation

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    We studied the electrophysiological basis of object recognition by recording scalp\ud electroencephalograms while participants played a virtual-reality taxi driver game.\ud Participants searched for passengers and stores during virtual navigation in simulated\ud towns. We compared oscillatory brain activity in response to store views that were targets or\ud nontargets (during store search) or neutral (during passenger search). Even though store\ud category was solely defined by task context (rather than by sensory cues), frontal ...\ud \u
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