Factors Underlying Students' Conceptions of Deep Time: An Exploratory Study

ABSTRACT Geologic or “deep time” is important for understanding many geologic processes. There are two aspects to deep time. First, events in Earth’s history can be placed in temporal order on an immense time scale (succession). Second, rates of geologic processes vary significantly. Thus, some events and processes require time periods (durations) that are outside a human lifetime by many orders of magnitude. Previous research has demonstrated that learners of all ages and many teachers have poor conceptions of succession and duration in deep time. The question is why. This exploratory, qualitative study investigates the viability of a model (a deep time stool) to capture the underlying factors necessary for a concept of deep time. The model posits that a concept of deep time rests upon: an understanding of succession and duration in conventional time; a robust understanding of large numbers and the proportional relationships among numbers of various magnitudes; and a learner’s geoscience content knowledge. While all three factors may not exist to the same degree in any one individual, all must be present to support a conception of deep time. Thirty-five students in the United States participated in individual task-based interviews: 12 eighth and 11 eleventh graders from a public charter school in the U.S. and 12 university students from two institutions enrolled in an introductory geoscience course. Tasks and questions probed students’ understandings of the three factors within and outside a deep time context, and the study is unique for that reason. Results indicate all three factors play an important role in how students understand deep time. While succession in conventional time proved non-problematic, duration was more difficult for participants. Some students were confused about the relationships among numbers in the thousands and millions, and others appeared to have little understanding of time periods up to 100 years. Participants had just as much difficulty dealing with the duration for events in conventional time as they did for those in deep time if the events were unfamiliar to them. Time and number share a similar spatial mapping strategy while knowledge of large numbers and geoscience content knowledge appear to provide reference points that can be used to judge the temporal order or duration of geoscience events. Implications for future research and classroom practice are discussed

Culturally Responsive Teaching: Teacher Candidates Identify What’s Important

Honorable Mention Winner Teacher preparation programs prepare teacher candidates (TC) with clinically rich field experiences. These programs prepare teachers to teach groups of students that are culturally, racially, and linguistically diverse. The TCs that participated in this study were in the first semester of the elementary program and were concerned with an experience that would be remote. COVID-19 impacted the experiences of the TCs by removing the field component during the Fall 2020 semester. The candidates were not provided access in the elementary schools to complete the practical experiences due to the districts’ pandemic guidelines. Due to the lack of exposure to diverse elementary students, the researchers wondered what the TCs would be interested in learning during a remote semester. This study was framed around culturally responsive teaching (CRT) and Geneva Gay’s five CRT essential elements. The TCs completed a survey in which they identified five items from the Culturally Responsive Teaching Self-Efficacy Scale (CRTSE) that they were most interested in learning during a pandemic semester. There was inconsistency in what culturally responsive teaching items the TCs were most interested to learn. Implications for the study were discussed

Research on Elementary, Middle, and Secondary Earth and Space Sciences Teacher Education

In order to fully engage with the vision of the Framework for K-12 Science Education and the NGSS, our nation needs a diverse and well prepared K-12 science teacher workforce. And in order for ESS to gain equal status with other sciences, the geoscience community must ensure that the K-12 science teacher workforce is adequately prepared to teach ESS core knowledge and practices. This is a challenging endeavor and complicated by the fact that the K-12 teacher education landscape is highly variable across institutions in terms of how much ESS content is included, how programs are structured, and how ESS fits into the larger institutional context. Teacher education exists in a complex landscape that involve many domains of research. This theme chapter focuses on teacher education research that most directly aligns to the undergraduate teaching and learning experience. Three grand challenges emerged from discussion and reflections on the existing literature and are poised to guide future research on undergraduate K-12 teacher education

Invasion of Europe by the western corn rootworm, Diabrotica virgifera virgifera: multiple transatlantic introductions with various reductions of genetic diversity

The early stages of invasion involve demographic bottlenecks that may result in lower genetic variation in introduced populations as compared to source population/s. Low genetic variability may decrease the adaptive potential of such populations in their new environments. Previous population genetic studies of invasive species have reported varying levels of losses of genetic variability in comparisons of source and invasive populations. However, intraspecific comparisons are required to assess more thoroughly the repeatability of genetic consequences of colonization events. Descriptions of invasive species for which multiple introductions from a single source population have been demonstrated may be particularly informative. The western corn rootworm (WCR), Diabrotica virgifera virgifera, native to North America and invasive in Europe, offers us an opportunity to analyse multiple introduction events within a single species. We investigated within- and between-population variation at eight microsatellite markers in WCR in North America and Europe to investigate the routes by which WCR was introduced into Europe, and to assess the effect of introduction events on genetic variation. We detected five independent introduction events from the northern USA into Europe. The diversity loss following these introductions differed considerably between events, suggesting substantial variation in introduction, foundation and/or establishment conditions. Genetic variability at evolutionarily neutral loci does not seem to underlie the invasive success of WCR in Europe. We also showed that the introduction of WCR into Europe resulted in the redistribution of genetic variance from the intra- to the interpopulational level contrary to most examples of multiple introductions

Lead zirconate titanate on base metal foils: An approach for embedded high-K passive components

An approach for embedding high-K dielectric thin films into polymer packages has been developed. Pb{sub 0.85}La{sub 0.15}(Zr{sub 0.52}Ti{sub 0.48}){sub 0.96}O{sub 3} thin films were prepared by chemical solution deposition on 50 {micro}m thick Ni-coated Cu foils. Sputter deposited Ni top electrodes completed the all base-metal capacitor stack. After high temperature N{sub 2} crystallization anneals, the PLZT composition showed reduction resistance while the base-metal foils remained flexible. Capacitance density and Loss tangent values range between 300 and 400 nF/cm{sup 2} and 0.01 and 0.02 from 1 to 1,000 kHz respectively. These properties represent a 2 to 3 order of magnitude improvement over available embedded capacitor technologies for polymeric packages

A case of pseudohypoaldosteronism type 1 with a mutation in the mineralocorticoid receptor gene

Pseudohypoaldosteronism type 1 (PHA1) is a rare form of mineralocorticoid resistance characterized in newborns by salt wasting with dehydration, hyperkalemia and failure to thrive. This disease is heterogeneous in etiology and includes autosomal dominant PHA1 owing to mutations of the NR3C2 gene encoding the mineralocorticoid receptor, autosomal recessive PHA1 due to mutations of the epithelial sodium channel (ENaC) gene, and secondary PHA1 associated with urinary tract diseases. Amongst these diseases, autosomal dominant PHA1 shows has manifestations restricted to renal tubules including a mild salt loss during infancy and that shows a gradual improvement with advancing age. Here, we report a neonatal case of PHA1 with a NR3C2 gene mutation (a heterozygous c.2146_2147insG in exon 5), in which the patient showed failure to thrive, hyponatremia, hyperkalemia, and elevated plasma renin and aldosterone levels. This is the first case of pseudohypoaldosteronism type 1 confirmed by genetic analysis in Korea

Accuracy of PECARN, CATCH, and CHALICE head injury decision rules in children: a prospective cohort study

© 2017 Elsevier Ltd Background Clinical decision rules can help to determine the need for CT imaging in children with head injuries. We aimed to validate three clinical decision rules (PECARN, CATCH, and CHALICE) in a large sample of children. Methods In this prospective observational study, we included children and adolescents (age

A framework for protein structure classification and identification of novel protein structures

BACKGROUND: Protein structure classification plays a central role in understanding the function of a protein molecule with respect to all known proteins in a structure database. With the rapid increase in the number of new protein structures, the need for automated and accurate methods for protein classification is increasingly important. RESULTS: In this paper we present a unified framework for protein structure classification and identification of novel protein structures. The framework consists of a set of components for comparing, classifying, and clustering protein structures. These components allow us to accurately classify proteins into known folds, to detect new protein folds, and to provide a way of clustering the new folds. In our evaluation with SCOP 1.69, our method correctly classifies 86.0%, 87.7%, and 90.5% of new domains at family, superfamily, and fold levels. Furthermore, for protein domains that belong to new domain families, our method is able to produce clusters that closely correspond to the new families in SCOP 1.69. As a result, our method can also be used to suggest new classification groups that contain novel folds. CONCLUSION: We have developed a method called proCC for automatically classifying and clustering domains. The method is effective in classifying new domains and suggesting new domain families, and it is also very efficient. A web site offering access to proCC is freely available a

Vaccine Effectiveness Estimates, 2004–2005 Mumps Outbreak, England

As vaccinated children approach adolescence, immunity wanes, which may contribute to outbreaks