7,529 research outputs found

    Creating Quality Undergraduate Research Programs in Economics: How, when, where (and why)

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    While undergraduate research (UR) has been growing across the academy for decades, economics has been relatively slow to adopt it as pedagogy. We argue for the development of comprehensive UR programs that not only require capstone research experiences, but integrate the development of foundational research skills throughout the curriculum. Fundamentally, there is a hierarchy whereby students learn basic research skills in lower-level courses, develop ability integrating content knowledge and research skills in upper-levels, and produce independent or collaborative research projects in later semesters. Successful UR programs depend on understanding this developmental model, integrating it into the curriculum, and taking advantage of resources to support it. To facilitate such improvements, we make six recommendations for departments to consider when building or strengthening their UR environment.undergraduate research, senior thesis, honors thesis, service learning, active learningQuality UGR

    Production rates of neon xenon isotopes by energetic neutrons

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    As a first step in an experimental program to study the behavior of noble gases produced in situ in minerals, a suite of minerals and pure chemicals were irradiated with 14.5 MeV neutrons at LLNL's Rotating Target Neutron Source (RTNS-II) and production rates for noble gases were determined. While neutron effects in meteorites and lunar samples are dominated by low-energy neutron capture, more energetic cosmic-ray secondary neutrons can provide significant depth-dependent contributions to production of cosmogenic nuclides through endothermic reactions such as (n,2n), (n,np), (n,d) and (n,alpha). Production rates for nuclides produced by cosmic-ray secondary neutrons are therefore useful in interpreting shielding histories from the relative abundances of cosmogenic nuclides. Absolute production cross sections were calculated from isotope dilution analyses of NaCl, Mg, CsCl, and Ba(NO3)2 samples, assuming purity, stoichiometry, and quantitative noble gas retention and extraction. Relative production cross sections determined from neon isotopic ratios in the mineral samples were also considered in evaluating the neon production cross sections. Results are presented

    Endocrine disrupting effects on the nesting behaviour of male three-spined stickleback Gasterosteus aculeatus L

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    The analysis of patterns of temporal variability in the nesting behaviour of male threespined stickleback (Gasterosteus aculeatus) exposed to the synthetic oestrogen, 17β-ethinylestradiol, revealed immediate, but transient, treatment-related effects. Gluing frequency and time spent near nest were significantly reduced in exposed fish at the beginning of the experiment. The expression of these behaviours subsequently recovered and there was no effect of treatment on nest building success. The potential causes and implications of these findings are discussed

    Mean first passage time analysis reveals rate-limiting steps, parallel pathways and dead ends in a simple model of protein folding

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    We have analyzed dynamics on the complex free energy landscape of protein folding in the FOLD-X model, by calculating for each state of the system the mean first passage time to the folded state. The resulting kinetic map of the folding process shows that it proceeds in jumps between well-defined, local free energy minima. Closer analysis of the different local minima allows us to reveal secondary, parallel pathways as well as dead ends.Comment: 7 page

    Lifelong learning and schools as community learning centres : key aspects of a national curriculum draft policy framework for Malta

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    The island of Malta has been engaged in policy document formulations for curriculum renewal in the country’s educational system (4-16 years of age) since 1988 when the first National Minimum Curriculum (henceforth NMC) was launched (Wain, 1991; Borg et al, 1995). In 1999 a revamped NMC (Ministry of Education, 1999) was developed following a long process of consultation involving various stages and stakeholders. It was a compromise document (Borg & Mayo, 2006) which emerged as a result of reactions to a more radical and coherent draft document produced in 1988. Both curricular documents were subject to debates and critiques (Wain, 1991; Darmanin, 1993; Borg et al, 1995; Giordmaina, 2000; Borg and Mayo, 2006). More recently a series of volumes providing guidelines, key principles and aims for a national curriculum framework (henceforth NCF) have been produced (MEEF, 2011a,b,c,d) and are currently the target of debate and the focus of reactions by various stakeholders in education including teachers who were asked to read the volumes and provide reactions in the form of answers to a set questionnaire. In this paper, I will focus on one aspect of the documents, the first of its three aims: ‘Learners who are capable of successfully developing their full potential as lifelong learners.’ It is that aspect of the framework documents that falls within the purview of the title for this special issue. The use of this notion attests to the influence of the EU’s policy communications on member states, Malta having joined the Union in 2004 (Mayo, 2007).peer-reviewe

    Can perceptual indices estimate physiological strain across a range of environments and metabolic workloads when wearing explosive ordnance disposal and chemical protective clothing?

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    Objective Explosive ordnance disposal (EOD) often requires technicians to wear multiple protective garments in challenging environmental conditions. The accumulative effect of increased metabolic cost coupled with decreased heat dissipation associated with these garments predisposes technicians to high levels of physiological strain. It has been proposed that a perceptual strain index (PeSI) using subjective ratings of thermal sensation and perceived exertion as surrogate measures of core body temperature and heart rate, may provide an accurate estimation of physiological strain. Therefore, this study aimed to determine if the PeSI could estimate the physiological strain index (PSI) across a range of metabolic workloads and environments while wearing heavy EOD and chemical protective clothing. Methods Eleven healthy males wore an EOD and chemical protective ensemble while walking on a treadmill at 2.5, 4 and 5.5 km·h− 1 at 1% grade in environmental conditions equivalent to wet bulb globe temperature (WBGT) 21, 30 and 37 °C. WBGT conditions were randomly presented and a maximum of three randomised treadmill walking trials were completed in a single testing day. Trials were ceased at a maximum of 60-min or until the attainment of termination criteria. A Pearson's correlation coefficient, mixed linear model, absolute agreement and receiver operating characteristic (ROC) curves were used to determine the relationship between the PeSI and PSI. Results A significant moderate relationship between the PeSI and the PSI was observed [r = 0.77; p < 0.001; mean difference = 0.8 ± 1.1 a.u. (modified 95% limits of agreement − 1.3 to 3.0)]. The ROC curves indicated that the PeSI had a good predictive power when used with two, single-threshold cut-offs to differentiate between low and high levels of physiological strain (area under curve: PSI three cut-off = 0.936 and seven cut-off = 0.841). Conclusions These findings support the use of the PeSI for monitoring physiological strain while wearing EOD and chemical protective clothing. However, future research is needed to confirm the validity of the PeSI for active EOD technicians operating in the field

    Barley Diets for Growing-Finishing Pigs

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    Barley is an important feed ingredient that may be used as an alternative for corn in swine diets. It is higher in protein and the amino acid lysine than is corn. But, it also contains less energy than corn and thus diets based on barley as the grain source are less efficient than corn based diets. It has also been suggested that hogs fed barley diets do not yield ~s well as those fed corn diets. The objectives of this experiment were to determine the effect of lysine and fat supplementation to barley based diets and to compare these diets with corn based diets. A further objective was to determine the effect of barley diets on carcass characteristics and dressing percentage

    Lysine Supplementation of Barley-Soybean Meal Diets for Growing Pigs

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    The lysine requirement of pigs as suggested by the National Research Council (NRC) was determined using corn-soybean meal based diets. More recent research has indicated that differences exist in the availability of lysine in different ingredients. It has been suggested that lysine in barley is less available than lysine in corn. Thus, it is possible that diets formulated with barley and soybean meal to meet the NRC\u27s suggested lysine requirement, might actually be deficient in this amino acid. This study was conducted to determine the lysine needs of pigs fed barley-soybean meal diets from approximately 45 to 75 lb
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