A Student-Centered Project for Earth System History

This article presents an idea for a classroom activity that is intended to replace some of the lectures that would ordinarily be necessary in a survey of Earth history over geologic time. Students take the lecturer's place in front of the class and present some of the material to their colleagues. They work in groups on a single era or period. Each student plays the role of an expert (such as an oceanographer) and works with teammates playing other sorts of experts (a biologist, a geologist, an atmospheric scientist). Their presentations will require them to do research and to construct resource lists to keep track of how they learned what they are presenting. They will also write brief summaries of the findings within their area of expertise. While the students are researching and preparing their presentations, the instructor will give lectures on the earliest time units, modeling the kind of presentation that the students will be doing. Eventually, students will take the stage, presenting their time units in order. Rubrics for assessing the presentation and the resource list are included. Educational levels: Graduate or professional

Asymmetric Vegetation Responses to Mid-Holocene Aridity at the Prairie-forest Ecotone in South-central Minnesota

The mid-Holocene (ca. 8000–4000 cal yr BP) was a time of marked aridity throughout much of Minnesota, and the changes due to midHolocene aridity are seen as an analog for future responses to global warming. In this study, we compare the transition into (ca. 9000–7000 yr ago) and out of (ca. 5000–2500 yr ago) the mid-Holocene (MH) period at Kimble Pond and Sharkey Lake, located along the prairie forest ecotone in south-central Minnesota, using high resolution (∼5–36 yr) sampling of pollen, charcoal, sediment magnetic and loss-on-ignition properties. Changes in vegetation were asymmetrical with increasing aridity being marked by a pronounced shift from woodland/forest-dominated landscape to a more open mix of grassland and woodland/savanna. In contrast, at the end of the MH, grassland remained an important component of the landscape despite increasing effective moisture, and high charcoal influxes (median 2.7–4.0 vs. 0.6–1.7mm2 cm−2 yr−1 at start of MH) suggest the role of fire in limiting woodland expansion. Asymmetric vegetation responses, variation among and within proxies, and the near-absence of fire today suggest caution in using changes associated with mid-Holocene aridity at the prairie forest boundary as an analog for future responses to global warmin

Outcomes of the “BRCA Quality Improvement Dissemination Program”: An Initiative to Improve Patient Receipt of Cancer Genetics Services at Five Health Systems

OBJECTIVE: A quality improvement initiative (QII) was conducted with five community-based health systems\u27 oncology care centers (sites A-E). The QII aimed to increase referrals, genetic counseling (GC), and germline genetic testing (GT) for patients with ovarian cancer (OC) and triple-negative breast cancer (TNBC). METHODS: QII activities occurred at sites over several years, all concluding by December 2020. Medical records of patients with OC and TNBC were reviewed, and rates of referral, GC, and GT of patients diagnosed during the 2 years before the QII were compared to those diagnosed during the QII. Outcomes were analyzed using descriptive statistics, two-sample t-test, chi-squared/Fisher\u27s exact test, and logistic regression. RESULTS: For patients with OC, improvement was observed in the rate of referral (from 70% to 79%), GC (from 44% to 61%), GT (from 54% to 62%) and decreased time from diagnosis to GC and GT. For patients with TNBC, increased rates of referral (from 90% to 92%), GC (from 68% to 72%) and GT (81% to 86%) were observed. Effective interventions streamlined GC scheduling and standardized referral processes. CONCLUSION: A multi-year QII increased patient referral and uptake of recommended genetics services across five unique community-based oncology care settings

A \u3e130,000-Year-Long Pollen Record from Pittsburg Basin, Illinois

Pittsburg Basin, in south-central Illinois, contains a sediment record extending from the present back to the end of the late Illinoian glaciation, when central Illinois was covered with Picea/Pinus forest. During the last interglaciation, a temperate deciduous forest more diverse than Holocene Quercus/Carya forest replaced the Illinoian late-glacial boreal forest. Prairie pollen types and the charcoal/pollen ratio, indicating fire frequency, temporarily increased. Then forest, with high Juniperus percentages, became dominant once more, as the charcoal/pollen ratio dropped. After the last interglaciation, the charcoal/pollen ratio increased again and prairie and wetland surrounded Pittsburg Basin through the entire Wisconsinan glacial age. The area was still prairie in late Wisconsinan time, but with some Picea and Pinus. During the Holocene, the region has been a mixture of prairie and Quercus/Carya forest. During the last interglaciation, Pittsburg Basin was surrounded by vegetation different from that surrounding it during the present interglaciation. Rather than indicating substantial differences in climate between analogous phases of different glacial/interglacial cycles, this variation may be due to changes in fire frequency, which could be caused by small changes in climate, human activity, or differences in soil

The End-Permian Mass Extinction and the Siberian Traps Eruptions

This handout focuses on the evidence for the theory that a series of flood-basalt eruptions in Siberia caused the mass extinction at the end of the Permian Period. This is the worst mass extinction known to geologists, and 90% or more of all species on Earth were wiped out. It is part of a set of four articles on possible causes of the Permian and Cretaceous mass extinctions that can be used to organize classroom debates or to have students compare and contrast the events and their causes

The End-Cretaceous Mass Extinction and the Chicxulub Impact

This handout focuses on the evidence for the theory that a massive meteor impact off the coast of Mexico caused the mass extinction at the end of the Cretaceous Period. The dinosaurs and about 75% of all marine invertebrate species and many other organisms died abruptly at this time. It is part of a set of four articles on possible causes of the Permian and Cretaceous mass extinctions that can be used to organize classroom debates or to have students compare and contrast the events and their causes

A Student-Centered Project for Earth System History

This project is intended to replace some of the lectures that would ordinarily be necessary in a survey of Earth history over geologic time. The students will be taking the lecturer\u27s place in front of the class, presenting some of the material to their colleagues. Students will work in groups on a single era or period. Each student role-plays an expert (such as an oceanographer) and works with teammates playing other sorts of experts (a biologist, a geologist, an atmospheric scientist). Their presentation will require them to do research. They will be constructing resource lists to keep track of how they learned what they are presenting and beginning a critical analysis of resources found on the World Wide Web. They will also write brief individual summaries of the findings within their area of expertise. While the students are researching and preparing their presentations, the instructor will start giving lectures on the earliest time units, modeling the kind of presentation that the students will be doing. Eventually, students will take the stage, presenting their time units in order. Rubrics for assessing the presentation and the resource list are included

Starting Out With Earth History

This activity asks students to place 6-10 events in Earth history on a timeline, first working in small groups and then as a class. Then, through questions, important points such as how certain events are dated, where humanity fits in, and so forth, can be brought up. The Starting Point website builds a context for the exercise by detailing the learning goals, teaching notes and materials (downloadable), and additional resources. Educational levels: Graduate or professional, Undergraduate lower division

Using the Geoscience Concept Inventory to Understand How Students Learn about Geologic Time

108 pre-service teachers completed a standardized multiple-choice test at the beginning and at the end of a ten-week introductory survey course on geology. Four of the fifteen questions dealt explicitly with geologic time. Correct student answers that the age of the Earth is known from uranium-series dating increased significantly, but only from ~0% to about 20%. However, answers that included U-series dating with other (irrelevant) sources of evidence increased from ~10% to ~70%. On the pre-test, students avoided the U-series dating in favor of incorrect, but probably more familiar, dating techniques or combinations of dating techniques. They seem to have gained familiarity with, if not an understanding of U-series dating in the class. There was no real change in students’ conceptions of what the newly-formed Earth would have looked like. Most (70% on pre-test, 65% on post-test) chose an image that looked like the modern Earth with a single continent (which they may have believed to be Pangea). Interestingly, 78% of those who chose that image on the pre-test chose it on the post-test, so they were not guessing. This is a powerful misconception and remained intact in most cases despite the work the students did in the geology class. On the other hand, most students appeared to be guessing when they answered how long Pangea took to break up. There were no significant changes in the totals for any response, but about half students changed their answers between the pre- and post-test with no significant pattern in the changes. Responses to a choice of timelines which all included the formation of the Earth, the appearances of life, dinosaurs, and humans, and the disappearance of dinosaurs, were more complex. There was an increase in the number of students who chose the correct timeline (from 20% to 42%), and a decrease in the number who chose a timeline in which all life appears at once (from 14% to 10%). In this case some misconceptions (based on incorrect answers on the pre-test) were more likely than others to grow into a correct understanding. For example, students who chose “C”, an incorrect timeline with events in the correct order but incorrectly scaled, on the pretest, were more likely to choose correctly on the post-test than students who gave other incorrect answers on the pre-test

The end-Permian mass extinction and a possible massive impact

This handout examines the evidence for the theory that a massive meteor impact caused the mass extinction at the end of the Permian Period. This is the worst mass extinction known to geologists, and 90% or more of all species on Earth were wiped out.It is part of a set of four articles on possible causes of the Permian and Cretaceous mass extinctions can be used to organize classroom debates or to have students compare and contrast the events and their causes