1,000 research outputs found
Surface charging of thick porous water ice layers relevant for ion sputtering experiments
We use a laboratory facility to study the sputtering properties of
centimeter-thick porous water ice subjected to the bombardment of ions and
electrons to better understand the formation of exospheres of the icy moons of
Jupiter. Our ice samples are as similar as possible to the expected moon
surfaces but surface charging of the samples during ion irradiation may distort
the experimental results. We therefore monitor the time scales for charging and
dis- charging of the samples when subjected to a beam of ions. These
experiments allow us to derive an electric conductivity of deep porous ice
layers. The results imply that electron irradiation and sputtering play a
non-negligible role for certain plasma conditions at the icy moons of Jupiter.
The observed ion sputtering yields from our ice samples are similar to previous
experiments where compact ice films were sputtered off a micro-balance.Comment: arXiv admin note: text overlap with arXiv:1509.0400
An Exploration of Alternative Scoring Methods Using Curriculum-Based Measurement in Early Writing
This manuscript describes two empirical studies of alternative scoring procedures used with curriculum-based measurement in writing (CBM-W). Study 1 explored the technical adequacy of a trait-based rubric in first grade. Study 2 explored the technical adequacy of a trait-based rubric, production-dependent, and production-independent scores in third grade. Results of Study 1 suggest that the rubric holds promise as a valid measure of sentence writing ability in first grade and has utility as a supplemental scoring procedure when using CBM-W as a screening tool. Results of Study 2 show that correct word sequences maintained the highest correlation coefficients across time with the trait-based rubric, but the other scoring procedures might offer promise as reliable alternative scoring methods. However, high internal correlations among the text features of the rubric along with highly variable interrater reliability suggest that caution must be taken in interpreting results
Scoring measures of word dictation curriculum-based measurement in writing: Effects of incremental administration
Spelling has been identified as a key transcription skill that emerges during the elementary years as students learn how to write and subsequently develop fluency with writing, making the assessment of spelling a critical component of evaluation systems within schools. This includes the use of curriculum-based measures of writing (CBM-W). This study examined the extent to which word dictation CBM-W administered during the Fall, Winter, and Spring of an academic year maintained technical adequacy across 1-min time intervals in grades 1–3. Results revealed moderate predictive and concurrent validity estimates with the Spelling subtest of the Weschler Individual Achievement Test-III. Statistically significant differences existed between and within grade levels across each minute of administration and across Fall, Winter, and Spring time points for all scoring procedures
Chapter 11: Teaching mathematics to students with disabilities from diverse backgrounds
According to the Organization for Economic Cooperation and Development (OECD), the literacy and numeracy skills that are distributed across a population will have significant impact on economic and social outcomes. In particular, the “higher the levels of inequality in literacy and numeracy skills … the greater the inequality of distribution of income” (OECD, 2013, p. 26). However, although literacy skills are important, it has been suggested that poor mathematical skills may be more of a handicap than poor literacy skills, especially in the workplace (Butterworth, 2005; McCloskey, 2007). As McCloskey (2007) notes, “… quantitative concepts and information are involved in many facets of home, work and community life …” (p. 421). Poor quantitative skills are likely to pose significant problems in everyday life, even into adulthood (Dougherty, 2003; McCloskey, 2007)
Metaphoric mapping and argument structure in semantic change: A case study
It is a well-known fact that abstract meanings usually have their origin in concrete domains, which are extended due to a process of metaphoric transfer. Meanings are thus extended in a motivated way. The study of the historical development of groups of verbs ofmental activity, for example, shows that many of them derive from verbs originally referring to physical activity. Whereas cognitively-based inter-domain metaphorical connections are crucial in semantic change, the close links between syntax and semantics cannot be ignored either. This paper approaches the syntax-semantics interface by bringing together the study of metaphoric mapping and verb complementation. Its aim is to investigate the risp of new subcategorization frames connected to the extension of verb senses from the concrete to the abstract domain. Thus, we explore how the rise of the abstract senses in a verb of mental activity —ponder—conforms, interacts with and is reflected in the argument structure of this verb
An integrated knowledge-based and optimization tool for the sustainable selection of wastewater treatment process concepts
Genesis and stability of textural pedofeatures along a soil transect in the siliceous Iberian Chain (NE Spain)
Textural features are widespread in many soils, provide pedogenetic evidence, and are fundamental in soil classification systems. The presence of these features and their conservation over time require certain processes and soil forming factors. This study investigates the genesis of textural pedofeatures, especially clay coatings, and the stressful conditions that can eventually lead to their disappearance. To achieve this goal, four profiles with clay-enriched horizons have been studied (macro- and micromorphology, physical, chemical and mineralogical properties and classification) along a transect in the siliceous Iberian Chain (NE-Spain).
The profiles, which have unmistakable illuvial accumulations in various horizons (Bhs, Bt, Btk), are classified (ST/WRB) as: a Spodosol/Podzol in the headslope, two Alfisol/Luvisols in the backslope and an Alfisol/Calcisol in the footslope. For the latter soil, the apparently strong difference in their classification to the first hierarchical level is due to the weight that the WRB places on the presence of an argic recarbonated horizon on a calcic horizon.
Clay illuviation was identified in all the soils, with coatings and infillings of microlaminated clay. These clayey pedofeatures are mostly mechanically fragmented or deformed, which is micromorphologically evidenced by an undulating, wavy extinction that does not run completely parallel to the surfaces they cover. Different destructive processes are identified along the soil transect; so, cryoturbation is the dominant process in the Podzol located at the highest elevation (Moncayo Massif). Instead, the clay coatings in the Btk horizon of the footslope (Calcisol) are covered and deformed by the growth of secondary calcite. The textural pedofeatures in this soil, which is very clayey, can also undergo argilloturbation processes, like in the backslope soils (Luvisols). In conclusion, several ongoing stress processes, that sometimes require different environmental conditions (polygenetic), affect most textural pedofeatures and lead to their progressive alteration and disappearance.Different projects of the Research Results Transfer Office of the University of Zaragoza (Ref. 2017/0535, ref. 2018/0416; ref. UZ2020-TEC-01) provided financial support for this research
Using Data-Based Instruction to Support Struggling Elementary Writers
Writing is a critical academic and life skill, but many school-age children struggle with the complexity of written expression. Given the importance of writing, there is a clear need for a systematic approach to identifying and supporting struggling writers, including writers with learning and emotional disabilities. One such approach is known as data-based instruction (DBI). This article presents an overview of DBI and guidance on how educators can use the DBI steps with assessment data to inform their classroom writing instruction. Additional resources are shared to support teachers in using DBI with their struggling writers and writers with learning and emotional disabilities
Assessment of microbial community structure changes by amplified ribosomal DNA restriction analysis (ARDRA)
Amplified ribosomal DNA restriction analysis (ARDRA) is a simple method based on restriction endonuclease digestion of the amplified bacterial 16S rDNA. In this study we have evaluated the suitability of this method to detect differences in activated sludge bacterial communities fed on domestic or industrial wastewater, and subject to different operational conditions. The ability of ARDRA to detect these differences has been tested in modified Ludzack-Ettinger (MLE) configurations. Samples from three activated sludge wastewater treatment plants (WWTPs) with the MLE configuration were collected for both oxic and anoxic reactors, and ARDRA patterns using double enzyme digestions AluI+MspI were obtained. A matrix of Dice similarity coefficients was calculated and used to compare these restriction patterns. Differences in the community structure due to influent characteristics and temperature could be observed, but not between the oxic and anoxic reactors of each of the three MLE configurations. Other possible applications of ARDRA for detecting and monitoring changes in activated sludge systems are also discussed
Additional data on Trypanosoma cruzi isozymic strains encountered in Bolivian domestic transmission cycles
- …