Complex anisotropy beneath the Peruvian flat slab from frequency-dependent, multiple-phase shear wave splitting analysis

Flat or shallow subduction is a relatively widespread global occurrence, but the dynamics remain poorly understood. In particular, the interaction between flat slabs and the surrounding mantle flow has yet to be studied in detail. Here we present measurements of seismic anisotropy to investigate mantle flow beneath the Peruvian flat-slab segment, the largest present-day region of flat subduction. We conduct a detailed shear wave splitting analysis at a long-running seismic station (NNA) located near Lima, Peru. We present measurements of apparent splitting parameters (fast direction ? and delay time ?t) for SKS, ScS, and local S phases from 80 events. We observe well-defined frequency dependence and backazimuthal variability, indicating the likely presence of complex anisotropy. Forward modeling the observations with two or three layers of anisotropy reveals a likely layer with a trench-normal fast direction underlying a layer with a more trench-oblique (to trench-subparallel) fast direction. In order to further constrain the anisotropic geometry, we analyzed the source-side splitting from events originating within the slab measured at distant stations. Beneath the flat-slab segment, we found trench-normal fast splitting directions in the subslab mantle, while within the dipping portion of the slab further to the east, likely trench-subparallel anisotropy within the slab itself. This subslab pattern contradicts observations from elsewhere in South America for “normal” (i.e., more steeply dipping) slab conditions. It is similar, however, to inferences from other shallowly dipping subduction zones around the world. While there is an apparent link between slab dip and the surrounding mantle flow, at least beneath Peru, the precise nature of the relationship remains to be clarified

A small-scale investigation into teachers' access to the regulating principles underlying the "new mathematics" curriculum in the Junior Primary phase

Bibliography: p. 101-107.This research project focuses on the "new primary mathematics" curriculum that has been implemented in the schools in the Western Cape over the past six years. The specific question I addressed was, 'What access do teachers have to the regulating principles underpinning the 'new primary mathematics' curriculum". The term "regulating principles" is drawn from the work of Paul Dowling (1993;98). In terms of this research, the regulating principles are the theoretical underpinnings to the new curriculum, which include substantially a theory of learning. I explore access to the regulating principles through semi-structured interviews with six teachers, who have implemented this new approach with different degrees of success, as measured in their own terms. I also investigate the official Teachers' Guide for Mathematics (Cape Education Department, 1993) for explicitness of theoretical underpinnings. An analysis of the teachers' guide indicated that the regulatory principles were not made explicit and the research indicates that the teachers in my sample have restricted access to these principles. I conclude that teachers who have little access to the regulating principles are constructed as a subordinate voice in relation to teacher educators, and must of necessity rely on procedure for their practice and be subject to external validation. This raises questions as to the successful implementation of the curriculum, in that it limits access by teachers to the educational debates surrounding theories of knowledge and theories of learning, and so inhibits teacher involvement in curriculum implementation. It also limits the ability of teachers to interrogate their own practice

Mathematical, cognitive and didactic elements of the multiplicative conceptual field investigated within a Rasch assessment and measurement framework

How may the essential elements of a framework including mathematical, cognitive, and didactic elements, and applied in the multiplicative conceptual field, address the challenges in mathematics education, and inform the curriculum and the validity of assessment processes

Stepping Stones to Information Literacy: a PebblePad case study

Aston University has recently made PebblePad, an e-portfolio or personal learning system, available to all students within the University. The customisable Profiles within PebblePad allow students to self-declare their skills in particular areas, attaching evidence of their skills or an action plan for improvement to each statement. Formal Information Literacy (IL) teaching within Aston University is currently limited to Library & Information Services (LIS) Information Specialists delivering a maximum of one session to each student during each level of their degree. However, many of the skills are continually developed by students during the course of their academic studies. For this project, an IL skills profile was created within PebblePad, which was then promoted to groups of staff and students to complete during the academic session 2009-10. Functionality within PebblePad allowed students to share their IL skills profile, evidence, action plans or any other items they felt were appropriate with an LIS Information Specialist who was able to add comments and offer suggestions for activities to help the student to develop further. Activities were closely related to students’ coursework where possible: suggesting a student kept a short reflective log of their information searching and evaluating process for an upcoming essay, for example. Feedback on the usefulness of the IL Profile will be sought from students through focus groups and the communication tools in PebblePad. In this way, we hope to make students more aware of their IL skills and to offer IL skills support over a longer period of time than a single session can provide. We will present preliminary conclusions about the practicalities and benefits of a self-declaration approach to developing IL skills in students at Aston University

Metabolic effects of a high-fat diet post-weaning after low maternal dietary folate during pregnancy and lactation

Scope Investigate the influence of low-folate supply during pregnancy and lactation on obesity and markers of the metabolic syndrome in offspring, and how provision of a high-fat diet post weaning may exacerbate the resultant phenotype. Methods and results Female C57Bl/6 mice were randomized to low or normal folate diets (0.4 or 2 mg folic acid/kg diet) prior to and during pregnancy and lactation. At 4 wk of age, offspring were randomized to high- or low-fat diets, weighed weekly and food intake assessed at 9 and 18 wk old. Adiposity was measured at 3 and 6 months. Plasma glucose and triacylglycerol (TAG) concentrations were measured at 6 months. Maternal folate supply did not influence adult offspring body weight or adiposity. High-fat feeding post weaning increased body weight and adiposity at 3 and 6 months (p > 0.001). Maternal low folate lowered plasma glucose (p = 0.010) but increased plasma TAG (p = 0.048). High-fat feeding post weaning increased plasma glucose and TAG (p = 0.023, p = 0.049 respectively). Offspring from folate-depleted (but not folate-adequate) dams had 30% higher TAG concentration when fed the high-fat diet from weaning (p = 0.005 for interaction). Conclusion Inadequate maternal folate intake has long-term effects on offspring metabolism, manifested as increased circulating TAG, particularly in offspring with high-fat intake post weaning

Assessing the energy justice implications of bioenergy development in Nepal

Background :  The emerging concept of energy justice has focused on the justice implications of conventional energy systems (oil, gas, coal, etc.). Instead, we focus on the meaning of energy justice in the context of unconventional energy systems, by investigating small-scale bioenergy development in Nepal. We approach energy justice as a conceptual framework that focuses on social justice implications of energy systems, with an emphasis on burden/benefit distributions and procedural or post-distributive justice, and consider its applicability beyond conventional energy systems. Methods:   Research was carried out in two parallel phases: (1) a quantitative phase, based on spatial analysis of secondary data, explores bioenergy distribution in Nepal, in relation to social-demographic characteristics, to investigate processes of distributive justice, and (2) a qualitative phase, based on thematic analysis of primary interview data, looks at post-distributive aspects of the energy reality in Nepal, to critically discuss the meaning of energy justice in this context. Results :  1) Biogas development is unevenly distributed, following patterns of social connectedness, which suggests significant spatial variation in capabilities or capability deprivations regarding individual agency in relation to (bio)energy. 2) There is a surprising inconsistency in the relationship between socially marginalised populations and attainment of biogas across the country, which needs further research. 3) Individual agency, supported or facilitated by enabling actors—particularly local biogas companies—is a key characteristic of local biogas development. 4) Decentralised, small-scale energy development gives rise to power dynamics differing fundamentally from those of conventional centralised energy systems, through radically different processes of procedural justice. Conclusions: Processes of energy justice are shown to exhibit strong spatial variability and are associated with social connectedness. Analysis focusing on processes of agency and empowerment leads to the conclusion that energy justice, to encourage unconventional energy development, should emphasise the necessary interconnection of individual rights, empowerment and responsibility.Publisher PDFPeer reviewe

A comparison of text difficulty in systemic assessment using Lexile theory

Abstract: In South Africa, the use of systemic assessments is controversial, raising issues of fairness. However, an argument can be made that they yield valuable insights into the current levels of literacy and education in the country. National systemic assessments are used to gauge scholastic progress across schools and provinces, while international tests provide some measure of comparability across countries. This article investigates the Lexile framework as an educational tool for gauging the reading difficulty of texts used in national and international assessments conducted in South Africa. The results of the Lexile analyses showed that the reading difficulty of the Annual National Assessments (ANA), conducted in 2014, varied between grades and did not match the same grade level in the Progress in International Reading Literacy Study (PIRLS). We argue that by using the Lexile framework during the designing phase of assessment, and selecting texts that are level appropriate for the learners, the assessment process may be enhanced

Towards validation of a rational number instrument : an application of Rasch measurement theory

Abstract: The rational number knowledge of student teachers, in particular the equivalence of fractions, decimals, and percentages, and their comparison and ordering, is the focus of this article. An instrument comprising multiple choice, short answer and constructed response formats was designed to test conceptual and procedural understanding. Application of the Rasch model enables verification of whether the test content was consistent with the construct under investigation. The validation process was enabled by making explicit the expected responses according to the model versus actual responses by the students. The article shows where the Rasch model highlighted items that were consistent with the model and those that were not. Insights into both the construct and the instrument were gained. The test items showed good fit to the model; however, response dependency and high residual correlation within sets of items was detected. Strategies for resolving these issues are discussed in this article. We sought to answer the research question: to what extent does this test instrument provide valid information that can be used to inform teaching and learning of fractions? We were able to conclude that a refined instrument applied to first-year students at university provides useful information that can inform the teaching and learning of rational number concepts, a concept that runs through mathematics curricula from primary to university. Previously, most research on rational number concept has been conducted on young learners at school

\u3cem\u3eNature and the Environment in Amish Life\u3c/em\u3e—David McConnell and Marilyn Loveless

In this symposium review, three agricultural and environmental researchers discuss the book Nature and the Environment in Amish Life by David McConnell and Marilyn Loveless, both of the College of Wooster in Wooster, Ohio. McConnell is an anthropology professor and co-author of Amish Paradox (2010, Johns Hopkins University Press) and has published his research in Human Organization, Anthropology and Education Quarterly, and the Journal of Amish and Plain Anabaptist Studies (JAPAS) (Moledina, et al. 2014). Loveless is a biology emeritus professor; this is her first academic publication about the Amish. Our reviewers offer a variety of reactions to this book. The first reviewer, historian Steven Reschly, is a founding board member of the Journal of Amish and Plain Anabaptist Studies and is currently assistant editor. He has written on Amish agricultural history in The Amish on the Iowa Prairie (2000, Johns Hopkins University Press) and in articles in Agricultural History, Mennonite Quarterly Review, JAPAS, and others. Scot Long completed his Ph.D. in anthropology at Ohio State University, having conducted extensive research on Amish farm households in southeastern Holmes County, OH. He has also published in JAPAS (Long and Moore 2014) about the impact of the environmental landscape on Amish church districts. Caroline Brock completed her Ph.D. in envirnoment and resources at the University of Wisconsin-Madison. Her research focuses on theoretical models for understanding Amish responses to agriculture and the environment, including organic dairy adoption and water quality conservation practices. Her research has appeared in Environmental Management, Society & Natural Resources, Journal of Rural Studies, Sustainability, JAPAS, and other outlets. She recently worked as a senior research associate at the Ohio Agricultural Research and Development Center in Wooster, OH. This book will certainly generate many conversations and hopefully inspire further research into the Amish relationships with agriculture and the environment. [Abstract by editor

Pretreatment of Spores as a Factor in Dimensional Analysis of Two Species of Histozoic Myxosporida

Spores of Henneguya exilis, taken during the summer of 1968 from the gills of Ictalurus punctatus caught in the Des Moines River near Knoxville, Iowa, and of a species of Myxosoma apparently closely related to Myxosoma ovalis, taken from the gills of Carpiodes velifer from the same locality, were subjected to storage at room temperatures, 4° C, and deep freezing. Repeated measurements of spores under different pretreatment showed that the dimensions of the spores and polar capsules remained remarkably stable, as did ratios of the dimensions of spore parts. Abnormalities in the details of spore architecture were seen under conditions under which dimensions remained stable. It is recommended that, wherever possible, unfixed spores be used for measurements, and preserved spores be used for other observations on which species descriptions are to be based