2,182 research outputs found

    Experience applying language processing techniques to develop educational software that allow active learning methodologies by advising students

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    This paper is focused on those systems that allow students to build their own knowledge by providing them with feedback regarding their actions while performing a problem based learning activity or while making changes to problem statements, so that a higher order thinking skill can be achieved. This feedback is the consequence of an automatic assessment. Particularly, we propose a method that makes use of Language Processor techniques for developing these kinds of systems. This method could be applied in subjects in which problem statements and solutions can be formalized by mean of a formal language and the problems can be solved in an algorithmic way. The method has been used to develop a number of tools that are partially described in this paper. Thus, we show that our approach is applicable in addressing the development of the aforementioned systems. One of these tools (a virtual laboratory for language processing) has been in use for several years in order to support home assignments. The data collected for these years are presented and analyzed in this paper. The results of the analysis confirm that this tool is effective in facilitating the achievement of learning outcomes

    Comparison of four strategies of ram management in a semen collection centre

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    Thirty Merino rams were used to determine the effect of four management systems of rams on semen quality during the anoestrous season. Animals were divided into four groups: Artificial-Photoperiod group (AP; n = 8), which were isolated from females and exposed to artificial long days (16 hr/d) from 1 Feb to 15 Mar; Natural-Photoperiod (NP; n = 8), isolated from females and exposed to the natural photoperiod throughout the experiment; Oestrous-Ewe group (EE; n = 7), housed in a pen adjacent to another pen that housed three ewes in oestrus, and Anestric-Ewe group (AE; n = 7), housed adjacent to another pen that housed three ovariectomized ewes. From 20 Mar to the end of May (10 weeks), semen samples were collected weekly, and blood samples were collected to determine plasma testosterone concentrations. Mean plasma testosterone concentrations, ejaculate volume and reaction time were not affected either by treatment or week. There was a significant effect (p < .01) of ram treatment on sperm concentration, and both TM y PM, and their interaction, were significantly affected by group and week (p < .001). Rams exposed to ewes in oestrus presented the largest sperm concentration (p < .05) compared with the other three groups, although they had the lowest total and progressive motilities (p < .01). In conclusion, management strategy in spring affects semen quality of rams, with the presence of ewes in oestrus being the best plan to increase sperm concentration

    Understanding the indirect DNA read-out specificity of I-CreI Meganuclease

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    The high DNA specificity of homing endonucleases makes them a powerful protein scaffold to engineer enzymes for genome manipulation. Understanding their molecular recognition of DNA is an important prerequisite to generate engineered enzymes able to cleave DNA in specific desired genome sites. Protein-DNA recognition studies have been mostly focused on specific direct contacts between amino acid side chains and bases to redesign the binding interface. However, the important role of indirect readout in the central region of the target DNA of the homing endonuclease I-CreI suggested that indirect readout may play a key role in the redesign of protein-DNA interactions. The sequences of the I-CreI central substrate region, 2NN, along with the adjacent 5NNN, are key for substrate cleavage. Here, we analyse the mechanism of target discrimination at the 5NNN region by the I-CreI protein, revealing its critical role in the location and occupancy of the catalytic metal ions, which is crucial for cleavage. Our data highlight the importance of indirect readout for target DNA cleavage, thus aiding I-CreI engineering when targeting new DNA sequences.e thank the Swiss Light Source (SLS) and ALBA beamline staff for their support. This work was supported by the Spanish MINECO (JCI-2011-09308 to R.M and CTQ2017-83810-R to F.J.B.), the Severo Ochoa Excellence Accreditation (SEV-2016-0644) and the Novo Nordisk Foundation (Grant NNF14CC0001 to G.M.),S

    Attitudes of Germans towards distributive issues in the German health system

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    Social health care systems are inevitably confronted with the scarcity of resources and the resulting distributional challenges. Since prioritization implies distributional effects, decisions on respective rules should take citizens’ preferences into account. Thus, knowledge about citizens’ attitudes and preferences regarding different distributional issues implied by the type of financing health care is necessary to judge the public acceptance of a health system. In this study we concentrate on two distributive issues in the German health system: First, we analyse the acceptance of prioritizing decisions concerning the treatment of certain patient groups, in this case patients who all need a heart operation. Here we focus on the fact that a patient is strong smoker or a non-smoker, the criteria of age or the fact that a patient has or does not have young children. Second, we investigate Germans’ opinions towards income dependent health services. The results reveal strong effects of individuals’ attitudes regarding general aspects of the health system on priorities, e.g. that individuals behaving health demanding should not be preferred. In addition, experiences of limited access to health services are found to have a strong influence on citizens’ attitudes, too. Finally, decisions about different prioritization criteria are found to be not independent.

    Weighing the Solar Axion

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    Axion helioscopes search for solar axions and axion-like particles via inverse Primakoff conversion in strong laboratory magnets pointed at the Sun. While helioscopes can always measure the axion coupling to photons, the conversion signal is independent of the mass for axions lighter than around 0.02 eV. Masses above this value on the other hand have suppressed signals due to axion-photon oscillations which destroy the coherence of the conversion along the magnet. However, the spectral oscillations present in the axion conversion signal between these two regimes are highly dependent on the axion mass. We show that these oscillations are observable given realistic energy resolutions and can be used to determine the axion mass to within percent level accuracies. Using projections for the upcoming helioscope IAXO, we demonstrate that >3σ>3\sigma sensitivity to a non-zero axion mass is possible between 3×1033 \times 10^{-3} and 10110^{-1} eV for both the Primakoff and axion-electron solar fluxes.Comment: 13 pages, 7 figures, matches published version, code available at http://cajohare.github.io/IAXOmas

    Magnetization reversal and exchange bias effects in hard/soft ferromagnetic bilayers with orthogonal anisotropies

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    The magnetization reversal processes are discussed for exchange-coupled ferromagnetic hard/soft bilayers made from Co[subscript 0.66]Cr[subscript 0.22]Pt[subscript 0.12] (10 and 20 nm)/Ni (from 0 to 40 nm) films with out-of-plane and in-plane magnetic easy axes respectively, based on room temperature hysteresis loops and first-order reversal curve analysis. On increasing the Ni layer thicknesses, the easy axis of the bilayer reorients from out-of-plane to in-plane. An exchange bias effect, consisting of a shift of the in-plane minor hysteresis loops along the field axis, was observed at room temperature after in-plane saturation. This effect was associated with specific ferromagnetic domain configurations experimentally determined by polarized neutron reflectivity. On the other hand, perpendicular exchange bias effect was revealed from the out-of-plane hysteresis loops and it was attributed to residual domains in the magnetically hard layer.National Science Foundation (U.S.)MIT-Spain/La Cambra de Barcelona Seed Fun

    Phisically based modelling of induction lamps: aplication to the improvement of energy efficiency in the lighting system of a University building. Poster

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    To manage efforts in energy efficiency, the Polytechnic University of Cartagena (UPCT) decided in 2003 to develop an ambitious project to reduce energy use intensity and costs during the period 2003-2008. To accomplish this objective in lighting end-use demand -one of the two main electrical uses together with space cooling/heating-, the UPCT joins, in July 2002, the U.E. GreenLight program as a partner. This paper describes the University experience in the second year (2003/04) of partnership in this UE initiative. The objectives were: to manage the demand, to improve the quality of lighting, working and environmental conditions, and reduce significantly energy and O&M expenses. Basically, the work developed in this year is focused in the change of conventional High Intensity Discharge (HID) lighting systems in classrooms (2000 m2) through the evaluation of advantages and drawbacks of different alternatives. The most promising one, the change to a new technology -165W induction lamps-, will be analyzed in detail in the paper
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