A machine learning approach to reading level assessment

Reading proficiency is a fundamental component of language competency. However, finding topical texts at an appropriate reading level for foreign and second language learners is a challenge for teachers. Existing measures of reading level are not well suited to this task, where students may know some difficult topic-related vocabulary items but not have the same level of sophistication in understanding complex sentence constructions. Recent work in this area has shown the benefit of using statistical language processing techniques. In this paper, we use support vector machines to combine features from n-gram language models, parses, and traditional reading level measures to produce a better method of assessing reading level. We explore the use of negative training data to handle the problem of rejecting data from classes not seen in training, and compare the use of detection vs. regression models on this task. As in many language processing problems, we find substantial variability in human annotation of reading level, and explore ways that multiple human annotations can be used in comparative assessments of system performance.     

Sorption characteristics of heavy metal ions by a natural zeolite

Zeolites have been shown to be effective adsorbents for the removal of heavy metals from aqueous solutions. A natural material from Cuba, containing zeolite, has been used for the removal of several metal ions, namely Cu²⁺, Zn²⁺, and Ni²⁺, to evaluate its potential use as a low‐cost adsorbent. Batch experiments have been conducted to evaluate the process kinetics and the removal equilibrium at different pH values, metal and zeolite concentrations. Pseudo‐second order kinetics and Freundlich equilibrium parameters have been obtained. Results suggested that this natural zeolite has a high potential for heavy metal retention. The selectivity of the studied metals was determined as Cu²⁺ ? Zn²⁺ > Ni²⁺, related to the first hydrolysis equilibrium constant. The metal removal efficacy was strongly dependent on pH, and to a lesser extent on metal/zeolite ratio. Copyright © 2005 Society of Chemical Industry     

Statistical Justification of Hillside Farm Dam Distribution in Eastern Australia

Understanding farm dams, including their distribution and reasoning, is important in Australia. While most researches have aimed at the impact of farm dams, quantifying their spatial distribution is highly desired from management perspective. However, it is a difficult task due to the large uncertainty in farm dam construction and its variation in size and usage. In this paper statistical relationships were established to estimate the number of farm dams and volumes from climate factors and geophysical characteristics. As the large farm dams are easy to be mapped and difficult to be modelled by statistics, the current research is concentrated on the small and medium farm dams. The following results are found: (1) The area with more precipitation tends to have more farm dams; (2) Winter precipitation tends to result in more farm dams; (3) the volumes of farm dams are small in flat areas and tend to increase as the slope increases till around 3° and then decrease; (4) higher fraction of absorbed Photosynthetically Active Radiation (fPAR), which is used to represent vegetation cover, tends to result in more farm dams with a linear relationship with recurrent fPAR and nonlinear relationship with persistent fPAR. Our models can also be used to predict the volumes of small and medium farm dams by these climate factors and catchment characteristics for mapping purposes.     

Quality assessment of Spanish universities’ web sites focused on the European Research Area

Summary This work has analyzed and evaluated the dissemination of research done at Spanish universities through the World Wide Web (WWW) in order to obtain a map of the visibility of the information available on this research and to propose measures for improving the quality of this diffusion, all within the social and institutional context of the European Area for Higher Education. The methodology applied in the study has used both qualitative and quantitative research methods to obtain some quality indicators on the dissemination of university research. The object of study consists of a sample of 19 Spanish universities, chosen according to their representativeness by Autonomous Community and their administrative and scientific weight. The process of defining indicators, both qualitative and quantitative, as well as the collection and analysis of data, are explained. The results give us a detailed panorama of the state of the art of the visibility of information on research in the web pages of selected universities. This has allowed us to make certain proposals for improvement that can contribute to the excellence of its dissemination.     

Advancing educational research on collaboration through the use of gStudy computer-supported collaborative learning (CSCL) tools: Introduction to special issue

This is an introduction to a special issue on computer-supported collaborative learning.     

Aldicarb Transport in Subsurface Environment: Comparison of Models

In this paper, two different pesticide transport simulation models are presented and compared to carry out preliminary analysis on the applicability of those models in determining ground-water vulnerability to aldicarb contamination. The first model is a physically based analytical model that simulates 1D pesticide movement in soils, based on the concept of complete mixing and 2D advective-dispersive transport in the aquifer. The second model is a numerical simulation model that links the existing numerical codes PRZM2, MODFLOW, and MT3D to simulate pesticide transport in the subsurface. The concentrations of aldicarb residues in soil and in the aquifer calculated by the two models are found to be in good agreement. However, the analytical model tends to produce an earlier arrival of the peak concentration in each year due to the assumption of complete mixing. It is also found that the infiltrating water following aldicarb application plays a significant role on the leaching potential of aldicarb, which is also affected by various meteorological and hydrological factors as well as by agricultural practices.     

Effect of instant controlled pressure drop on the oligosaccharides, inositol phosphates, trypsin inhibitors and lectins contents of different legumes

Well-controlled technologies for seed treatment have become a necessity for the food industry. Instant controlled pressure drop treatment (DIC®) is a new and highly controlled process that combines steam pressure (up to 8 bar) with heat (up to 170 °C) for a short time (up to 3 min). The end-product is a whole seed with a porous texture. The aim of this work was to evaluate the effect of this new (DIC) process on the contents of nutritionally active factors (NAF_s) in soybean, lupin, lentil, chickpea and roasted peanut. Unprocessed (control) and processed (DIC treatment under different pressure and time conditions) ground samples were analysed for oligosaccharides, inositol phosphates, trypsin inhibitors and lectins. The effect of DIC treatment on NAF_s in legume seeds has shown that this process considerably reduces most of these components; the optimum condition for DIC treatment in all the seeds was DIC-3 (6 bar, 1 min). The main advantages of DIC are its short processing time and the possibility of treating whole seeds for industrial applications.     

Shelf-Life Extension of Fresh Tuber aestivum and Tuber melanosporum Truffles by Modified Atmosphere Packaging with Microperforated Films

ABSTRACT: The aim of this study was to design a modified atmosphere packaging suitable for Tuber melanosporum and Tuber aestivum truffles that extend their shelf life and their availability as a fresh product. Their respiration rates were determined by O₂ depletion and CO₂ formation in closed systems performed at different temperatures: 4, 10, and 23 °C. The results were fitted by exponential equations and derivatives of these equations were used to obtain the experimental respiration rates. Our results revealed high respiration rates in both species of truffles and respiratory quotients (RQ) higher than 1 in all the cases studied. A linear dependence of respiration rate, both R_O2 and R_CO2, on O₂ concentration was revealed. A mathematical model was used to predict the evolution of the gaseous composition at 4 °C in the interior of polypropylene trays (250 mL) heat sealed with 4 microperforated films of different transmission rates. A microperforated film with 2 holes (90 × 50 μm) was selected to produce an internal atmosphere of 15%CO₂/7%O₂ at 4 °C. The predicted atmosphere composition was confirmed by the experimental results. The quality and microbiological characteristics of fresh truffles, packaged in these conditions, revealed that the microbial counts of pseudomonads and Enterobacteriaceae were decreased, the weight loss was reduced, the typical hard texture was maintained, and the development of mycelium growth was delayed, enabling good scores for aroma and flavor, and therefore prolonging the shelf life of T. melanosporum and T. aestivum truffles to 28 and 21 d, respectively. Practical Application: This study describes the benefits of using MAP with microperforated films in the postharvest storage of Tuber melanosporum and Tuber aestivum fresh truffles. The shelf life of T. aestivum is prolonged to 21 d and of T. melanosporum to beyond 28 d increasing the possibilities for a foreign market.     

Development and validation of an attributional style questionnaire for adolescents.

We describe the development and psychometric characteristics of a new version of the Attributional Style Questionnaire (ASQ; Seligman, Abramson, Semmell, & Von Baeyer, 1979)—a version called the Attributional Style Questionnaire for Adolescents (ASQ-A)—using 3 samples (Ns = 547, 438, and 240) of Spanish secondary school students. In Study 1, the initial pool of 87 items was reduced to 54. Study 2 further analyzed the 54 scale items and revealed that the Internality, Stability, and Globality subscale scores had good reliability, good factorial construct validity, and satisfactory associations with maladaptive mood ratings. In Study 3, the regression analyses showed good and specific predictive validities of ASQ-A subscales for the attributions that the adolescents made about a particular real-life stressful situation. Study 4 showed that over an 8-month period the changes in the Stability and Globality subscales depended on the intensity of stressful life events experienced in this period. Overall, the studies revealed that the new ASQ-A served as an appropriate instrument to assess attributional style in adolescents. (PsycINFO Database Record (c) 2010 APA, all rights reserved)