Using Primary Sources in STEM Education: An Example

Primary sources are original artifacts from the past that can used to understand an event or time period. They are customarily only thought of in the realm of historical thinking. That is unfortunate because they can also be considered in terms of scientific, economic, cultural, and mathematical thinking. While primary sources are increasingly taking more prominent roles in the social studies and history classrooms, they are still very rare in other disciplines. This paper describes how primary sources gathered from the Library of Congress were situated in a larger STEM lesson focusing on the challenges faced by WWI veteran amputees. Lesson reflection found that with sufficient scaffolding and other support, primary sources make an excellent resource for STEM teachers. Further, STEM and primary sources make natural partners in teaching and learning because they both have an interdisciplinary nature and tend be applied to real world situations

Life cycle and sexuality of the freshwater raphydophyte Gonyostomum semen (Raphydophyceae)

Previously unknown aspects in the life cycle of the freshwater flagellate Gonyostomum semen (Ehrenb.) (Raphidophyceae) are described here. This species forms intense blooms in many northern temperate lakes, and has increased in abundance and frequency in northern Europe during the past decades. The proposed life cycle is based on observations of life cycle stages and transitions in cultures. Viable stages of the life cycle were individually isolated and monitored by time-lapse photography. The most common processes undertaken by the isolated cells were: division, fusion followed by division, asexual cyst formation, and sexual cyst formation. Motile cells divided by two different processes. One lasted between 6 and 24 h and formed two cells with vegetative cell size and with or without the same shape. The second division process lasted between 10 and 20 min and formed two identical cells, half the size of the mother cell. Planozygotes formed by the fusion of hologametes subsequently underwent division into two cells. Asexual cyst-like stages were spherical, devoid of a thick wall and red spot, and germinated in 24–48 h. Heterogamete pairs were isogamous, and formed an angle of 0–90° between each other. Planozygote and sexual cyst formation were identified within strains established from one vegetative cell. The identity of these strains, which was studied by an amplified fragment length polymorphism analysis, was correlated with the viability of the planozygote. Resting cyst germination was described using cysts collected in the field. The size and morphology of these cysts were comparable with those formed sexually in culture. The excystment rate was higher at 24°C than at 19 or 16°C, although the cell liberated during germination (germling) was only viable at 16°C. The placement of G. semen within the Raphidophyceae family was confirmed by sequence analysis of a segment of the 18S ribosomal DNA.Postprin

Place-Free and Place-Based Educational Preferences Among Rural High School Principals

Rural schooling and rural communities are interdependent to a degree not seen in suburban and urban contexts. Thus, the threat to the sustainability of one inevitably affects the other. One of the variables in their sustainability may be educational practices (Haas & Nachtigal, 1998; White & Reid, 2008) that influence the likelihood of rural high school graduate outmigration (Corbett, 2007; Huang, Cohen, Weng, & Zhang, 1996). Considering the body of literature that testifies to the strong influence school administrators have in schools (Hallinger & Heck, 1996; Leithwood & Jantzi, 2000; Prestine & Nelson, 2005), understanding the preferences in educational practices by rural school administrators is worthy of study. This study sought to understand the relationship between preferences in educational practices and length of tenure in the context of American historical and political streams among nine rural high school principals in a Rocky Mountain state. The maximum variation sampling strategy created three Administrative Roots Groups (shallow, moderate, and deep). Data was analyzed inductively using the constant comparative analysis method. A moderately strong positive relationship between tenure and preferences for place-based education (PBE) was found. This suggests that strategies need to be implemented to decrease rural high school principal turnover. Additionally, the twin findings that principals felt that their communities were often too small or too homogenous for PBE and that state standards did not allow for PBE suggests that the orientation needs to be incorporated into educational leadership programs (especially in light that none of the principals recalled being exposed to PBE in their educator programs). Also, it appears that better dialogue is needed from state and federal education agencies about acceptable instructional practices in our present standards-based environment

Construction and Characterization of Varicella-zoster virus DNA Encapsidation Protein Expressing Cell Lines

Mutant viruses containing deletions in DNA encapsidation genes have been characterized in detail for Herpes simplex type I, and to some extent for Pseudorabies virus, and Human cytomegalovirus. However, similar mutants for Varicella-zoster virus do not exist. It is expected that the deletion of each putative DNA encapsidation gene will yield a phenotype consistent with a defect in DNA cleavage and/or packaging. These mutant viruses will be isolated by site directed homologous recombination in complementing cell lines expressing the respective DNA encapsidation proteins

Instructional Learning Teams: A Case Study

Changing teacher practices to improve student learning is a challenge. For teachers’ practices to change, faculties within schools must build communities of practice. However, supporting teachers’ collaborative learning within a Professional Learning Team can be an elusive challenge. We found through the Instructional Learning Team (ILT) model of professional development that teachers have a focused model to make effective changes to their practice. ILTs promote school improvement by providing a process through which teachers collaboratively focus on sustained reflection about student learning tasks, instruction, and student work using the Japanese Lesson Study and critiquing their work using Newmann’s (1996) Intellectual Quality framework. We followed two teams of teachers over a semester and qualitatively examined changes in four elements of professional learning: shared ideas and values, focus on student learning, reflective dialogue, and deprivatization of practice. Through the ILT process all four elements of professional learning communities increased. This process of changing practice through examining instructional tasks, practices and student work has a direct impact on helping teachers move toward implementing the Common Core State Standards (CCSS)

Connecting Science with Engineering: Using Inquiry and Design in a Teacher Professional Development Course

The engineering design process has evolved over time to be the central and effective framework that engineers use to conduct their work. Logically, K-12 STEM professional development efforts have then attempted to incorporate the design process into their work. There has been little in the STEM literature, though, of the explicit measurement of the growth in design process knowledge. Our study presents findings of significant improvements in knowledge of the design process that resulted over the course of a recent summer STEM institute and professional development program among K-5 teachers. As more emphasis is placed on integrating STEM into the curriculum 1 there is a need to enhance the capacity for K-12 teachers. Responding to this call the Colleges of Engineering and Education at Boise State University collaborated to offer an intensive three-day summer institute to address the preparation of elementary school teachers (grades K-5) to teach STEM curriculum. The focus of our institute was on the use of both inquiry and design as approaches for integrating STEM content. In particular we explicitly stressed the link between science and inquiry and engineering and design, how these processes differ, how they can complement each other and how they can be used instructionally to teach a wide range of STEM content. The instructional materials used in the workshop included Lego®-like bricks called PCS BrickLab® (supplied by PCS Edventures! an educational products company) and other common classroom items such as paper, tape, string, and cardboard.. Each participant received a classroom set of the materials at the close of the workshop. The BrickLab® kit contains over 5,000 bricks which is sufficient to simultaneously engage up to about 30 students in hands-on activities, which makes these instructional materials particularly suitable to facilitate classroom instruction using inquiry and design. We engaged the participants in a series of hands-on activities focused on the inquiry process of manipulating variables to gather data to explain phenomena or design processes that focus on creating and refining the best solution given constraints. To determine the effectiveness of our workshop we gathered pre and post data to assess our 58 participants\u27 comfort for teaching STEM, their STEM pedagogical discontentment, their implementation of inquiry curriculum, and their knowledge of the design process. Our initial results indicate significant increases in comfort teaching STEM (t = 12.761, p \u3c .01), decreases in STEM pedagogical discontentment (t = 7.281, p \u3c .01), and increases in design process knowledge (t = 6.072, p \u3c .01). Delayed post data collection for the implementation of inquiry took place in Fall 2010, which allowed time for the participating teachers to apply their learned knowledge and develop a post conference context for their instructional practice with students. All instruments used for data collection were extant and had established reliability and validity. Our results indicate that our three-day summer institute and follow-up support increased our participants\u27 knowledge of design along with comfort for teaching STEM. Also, the institute decreased the teachers’ pedagogical discontentment for teaching STEM

Sexual reproduction and two different encystment strategies of Lingulodinium polyedrum (Dinophyceae) in culture

Unreported aspects in the sexual cycle of the marine dinoflagellate Lingulodinium polyedrum (Stein) Dodge were described. Our observations included the description of two types of hypnozygote formation, because culture planozygotes were observed to encyst in two different ways: an ecdysal sexual stage or a spiny resting cyst. Phosphate deficiency was the main nutritional condition required for fusing gamete pairs to form resting cysts, whereas replete conditions prevented their appearance and favored the formation of ecdysal sexual forms. Mating experiments revealed the existence of two sexual types (+/−), which were enough to explain resting cyst appearance (simple heterothallism). Morphological aspects and timing of gamete mating, fusion, and the efficiency of encystment under different external levels of nitrate and phosphate were analyzed after isolating and monitoring individual pairs of fusing gametes. The staining of sexual stages showed that nuclear fusion was completed at the same time as the cytoplasmic fusion. After 1 to 2 h, the planozygotes presented one quadrolobulated nucleus. Germination of ecdysal sexual stages occurred after <24–72 h, whereas excystment of resting cysts was dependent on the studied parental cross and took place after 2–4 months. Newly germinated cells from both types of cysts had a similar, big, U-shaped nucleus. Twenty-four to 48 h after excystment, the germlings divided by desmoschisis, a process before which enlargement of the nucleus was observed.Postprin

The Hidden Sexuality of Alexandrium Minutum: An Example of Overlooked Sex in Dinoflagellates

Dinoflagellates are haploid eukaryotic microalgae in which rapid proliferation causes dense blooms, with harmful health and economic effects to humans. The proliferation mode is mainly asexual, as the sexual cycle is believed to be rare and restricted to stressful environmental conditions. However, sexuality is key to explaining the recurrence of many dinoflagellate blooms because in many species the fate of the planktonic zygotes (planozygotes) is the formation of resistant cysts in the seabed (encystment). Nevertheless, recent research has shown that individually isolated planozygotes in the lab can enter other routes besides encystment, a behavior of which the relevance has not been explored at the population level. In this study, using imaging flow cytometry, cell sorting, and Fluorescence In Situ Hybridization (FISH), we followed DNA content and nuclear changes in a population of the toxic dinoflagellate Alexandrium minutum that was induced to encystment. Our results first show that planozygotes behave like a population with an “encystment-independent” division cycle, which is light-controlled and follows the same Light:Dark (L:D) pattern as the cycle governing the haploid mitosis. Resting cyst formation was the fate of just a small fraction of the planozygotes formed and was restricted to a period of strongly limited nutrient conditions. The diploid-haploid turnover between L:D cycles was consistent with two-step meiosis. However, the diel and morphological division pattern of the planozygote division also suggests mitosis, which would imply that this species is not haplontic, as previously considered, but biphasic, because individuals could undergo mitotic divisions in both the sexual (diploid) and the asexual (haploid) phases. We also report incomplete genome duplication processes. Our work calls for a reconsideration of the dogma of rare sex in dinoflagellates.Versión del edito

Costs and underuse of insulin and diabetes supplies: Findings from the 2020 T1 International cross-sectional web-based survey

Aims: To investigate self-reported out-of-pocket expenses (OoPE) associated with insulin and diabetes supplies for people living with type 1 diabetes (T1D) worldwide. Methods: A web-based, cross-sectional survey was conducted from August to December 2020. The analysis included comparisons between responses from countries with no, partial, and full healthcare coverage. Results: 1,066 participants from 64 countries took part in the study. ~25% of respondents reported having underused insulin at least once within the last year due to perceived cost. A significant correlation was observed between OoPEs and reported household income for respondents with partial healthcare coverage. 63.2% of participants reported disruption of insulin supplies and 25.3% reported an increase of prices related to the COVID-19 pandemic. Conclusions: This study confirms previous reports of ~25% of people in the United States with T1D using less insulin and/or fewer supplies at least once in the last year due to cost, a trend associated with the extent of healthcare coverage. Similar trends were observed in some middle/low income countries. Moreover, patients reported an increase in insulin prices and disruption of supplies during the COVID-19 pandemic. This study highlights the importance of self-reported OoPEs and its association with underuse/rationing of insulin.Arnold VenturesCenter for Translational Science and Trainin