Integrating Writing in the Middle-Level Mathematics Classroom: An Action Research Study

Discourse in mathematics refers to the written and oral communication that occurs in the mathematics classroom. Yet, in many classrooms in the United States, writing is often taught remotely in the classroom of a language arts teacher. In this action research project, our focus was on improving students’ written expressions and explanations in the middle-level mathematics classroom. The purpose of this action research was to examine and evaluate the effect writing has on students’ mathematical thinking processes and skills. Over the course of eight weeks, students were presented with various writing assignments in mathematics. Students were given approximately 20 minutes to brainstorm, reflect, and complete their journal prompts each day. Math journaling during the mathematical workshop appeared to have a positive effect on student motivation as well as to increase conceptual understanding. Based on the results of this study implications are provided for future research and classroom practice

Drivers of plant community biodiversity: understory dynamics in longleaf pine savannas of North Carolina

When properly managed, the longleaf pine (LLP) savanna ecosystem is one of the most biologically diverse habitats in the world due to the high density of understory plant species. The ecosystem has played a vital role in building the economy and culture of the U.S. southeast over centuries, but anthropogenic influences (e.g. land conversion, logging, fire suppression, etc.) have decimated this ecosystem and the biodiversity it holds, making restoration a necessity. This study investigated the drivers of biodiversity in LLP-wiregrass (Pinus palustris Mill. – Aristida stricta Michx.) savannas at small (1m2) and local (25m2) spatial scales in order to provide crucial information and focus for restoration strategies, improving the management and health of LLP savanna. I collected species composition data along with various site and stand level characteristics at 15 study plots across North Carolina. Various regression analysis techniques were then used to identify potential drivers of biodiversity. This study found considerable variation in biodiversity and community composition across study plots, with small scale richness ranging from 2 to 11.8, and a regional richness of 143 species. Additionally, A. stricta was found to be a significant driver of biodiversity at both spatial scales, and a unimodal relationship between productivity and richness was found, which agrees with results found in other LLP-A. stricta savanna communities. The presence of this dominant grass species has a positive effect on biodiversity, but with increasing abundance, there is a decrease in every biodiversity metric, with the ideal relative cover of wiregrass being 16% for enhancing and maintaining biodiversity at small scales. If LLP savanna land owners and managers can implement this ideal relative cover of wiregrass in their restoration strategies, the health and function can be restored to this ecosystem, as well as the biodiversity. Unfortunately, in today’s society, restoring the economically important tree in the LLP ecosystem is often all that people focus on as it has direct monetary benefits. However, the understory provides numerous other provisioning services such as carbon sequestration and erosion and flood control, habitat for endangered species, and biodiversity itself. LLP savannas are so much more than the LLP tree that dominates the skyline, and understanding the drivers of the understory biodiversity will aid in the restoration of an essential component of this critically threatened ecosystem

Neuropathogenic Forms of Huntingtin and Androgen Receptor Inhibit Fast Axonal Transport

AbstractHuntington's and Kennedy's disease are autosomal dominant neurodegenerative diseases caused by pathogenic expansion of polyglutamine tracts. Expansion of glutamine repeats must in some way confer a gain of pathological function that disrupts an essential cellular process and leads to loss of affected neurons. Association of huntingtin with vesicular structures raised the possibility that axonal transport might be altered. Here we show that polypeptides containing expanded polyglutamine tracts, but not normal N-terminal huntingtin or androgen receptor, directly inhibit both fast axonal transport in isolated axoplasm and elongation of neuritic processes in intact cells. Effects were greater with truncated polypeptides and occurred without detectable morphological aggregates

Electrical and material properties of hydrothermally grown single crystal (111) UO2

The semiconductor and optical properties of UO2 are investigated. The very long drift carrier lifetimes, obtained from current-voltage I(V) and capacitance-voltage C(V) measurements, along with the well-defined optical properties provide little evidence of an abundance of material defects away from the surface region. Schottky barrier formation may be possible, but very much dependent on the choice of contact and surface stoichiometry and we find that Ohmic contacts are in fact favored. Depth resolved photoemission provided evidence of a chemical shift at the surface. Density functional theory, with the Heyd-Scuseria-Ernzerhof (HSE) functional, indicates a band gap of a 2.19 eV and an anti-ferromagnetic ground state. Ellipsometry measurements indicates at UO2 is relatively isotropic with a band gap of approximately 2.0 eV band gap, consistent with theoretical expectations

The Total Syntheses of JBIR-94 and Two Synthetic Analogs and Their Cytotoxicities Against A549 (CCL-185) Human Small Lung Cancer Cells

We here disclose the total syntheses of the natural polyphenol JBIR-94 and two nonnatural analogs, whose structures are of interest for their bioactivity potential as radical scavengers. Although we initially attempted this by dually acylating both of putrecine’s amine nitrogens in a single pot, our endeavors with this method (which has been successfully reported by other groups) proved ineffectual. We accordingly opted for the lengthier approach of acylating each amine individually, which gratuitously prevailed and also aligns with separate literature precedent. Moreover, we here share our analysis of these target compounds’ cytotoxicities and IC50 values against A549 (CCL-185) human small lung cancer cells

The Total Syntheses of JBIR-94 and Two Synthetic Analogs and Their Cytotoxicities Against A549 (CCL-185) Human Small Lung Cancer Cells

We here disclose the total syntheses of the natural polyphenol JBIR-94 and two nonnatural analogs, whose structures are of interest for their bioactivity potential as radical scavengers. Although we initially attempted this by dually acylating both of putrecine’s amine nitrogens in a single pot, our endeavors with this method (which has been successfully reported by other groups) proved ineffectual. We accordingly opted for the lengthier approach of acylating each amine individually, which gratuitously prevailed and also aligns with separate literature precedent. Moreover, we here share our analysis of these target compounds’ cytotoxicities and IC50 values against A549 (CCL-185) human small lung cancer cells

Heatwave implications for the future of longleaf pine savanna understory restoration

The longleaf pine (LLP) savanna ecosystem once covered ~ 92 million acres of the Southeast USA,but due to anthropogenic activities such as logging and fire suppression, only 3% of its oncewidespread historic range remains. While many restoration efforts are underway to conserve thisbiodiverse ecosystem, restoration must be done in the context of climate change. In the last fewdecades, heatwaves have increased in frequency and intensity across the Southeastern USA withfurther increases predicted. To expand our understanding of LLP savanna restoration in light ofthese changes, we ran a series of three simulated heatwave greenhouse experiments through aCourse-based Undergraduate Research Experience (CURE) incorporating ~ 150 undergraduateresearchers per experiment. We measured plant growth metrics for four understory grassescommonly used in LLP savanna restoration efforts. We found that while most grass plugindividuals survived heatwave conditions, aboveground production was reduced due to heatwaves.This productivity decrease could result in less biomass available for the essential vegetation fire feedback loop, where fire increases grass biomass, and in turn, more grass provides more fuel for fire. These results imply that land managers can proactively compensate for biomass loss due toheatwaves by planting more grass plugs during initial restoration. © 2021, The Author(s), underexclusive licence to Springer Nature B.V

Nothing lasts forever: Dominant species decline under rapid environmental change in global grasslands

Dominance often indicates one or a few species being best suited for resource capture and retention in a given environment. Press perturbations that change availability of limiting resources can restructure competitive hierarchies, allowing new species to capture or retain resources and leaving once dominant species fated to decline. However, dominant species may maintain high abundances even when their new environments no longer favour them due to stochastic processes associated with their high abundance, impeding deterministic processes that would otherwise diminish them. Here, we quantify the persistence of dominance by tracking the rate of decline in dominant species at 90 globally distributed grassland sites under experimentally elevated soil nutrient supply and reduced vertebrate consumer pressure. We found that chronic experimental nutrient addition and vertebrate exclusion caused certain subsets of species to lose dominance more quickly than in control plots. In control plots, perennial species and species with high initial cover maintained dominance for longer than annual species and those with low initial cover respectively. In fertilized plots, species with high initial cover maintained dominance at similar rates to control plots, while those with lower initial cover lost dominance even faster than similar species in controls. High initial cover increased the estimated time to dominance loss more strongly in plots with vertebrate exclosures than in controls. Vertebrate exclosures caused a slight decrease in the persistence of dominance for perennials, while fertilization brought perennials' rate of dominance loss in line with those of annuals. Annual species lost dominance at similar rates regardless of treatments. Synthesis. Collectively, these results point to a strong role of a species' historical abundance in maintaining dominance following environmental perturbations. Because dominant species play an outsized role in driving ecosystem processes, their ability to remain dominant—regardless of environmental conditions—is critical to anticipating expected rates of change in the structure and function of grasslands. Species that maintain dominance while no longer competitively favoured following press perturbations due to their historical abundances may result in community compositions that do not maximize resource capture, a key process of system responses to global change.Fil: Wilfahrt, Peter A.. University of Minnesota; Estados UnidosFil: Seabloom, Eric. University of Minnesota; Estados UnidosFil: Bakker, Jonathan. University of Washington; Estados UnidosFil: Biederman, Lori. Iowa State University; Estados UnidosFil: Bugalho, Miguel N.. Universidade Nova de Lisboa; PortugalFil: Cadotte, Marc W.. University of Toronto–Scarborough; Estados UnidosFil: Caldeira, Maria C.. Universidade Nova de Lisboa; PortugalFil: Catford, Jane A.. University of Melbourne; AustraliaFil: Chen, Qingqing. Peking University; China. German Centre for Integrative Biodiversity Research; AlemaniaFil: Donohue, Ian. Trinity College Dublin; IrlandaFil: Ebeling, Anne. University of Jena; AlemaniaFil: Eisenhauer, Nico. German Centre for Integrative Biodiversity Research; Alemania. Leipzig University; AlemaniaFil: Haider, Sylvia. Martin Luther University Halle-Wittenberg; Alemania. Leuphana University of Lüneburg; AlemaniaFil: Heckman, Robert W.. University of Texas; Estados Unidos. United States Forest Service; Estados UnidosFil: Jentsch, Anke. University of Bayreuth; AlemaniaFil: Koerner, Sally E.. University of North Carolina Greensboro; Estados UnidosFil: Komatsu, Kimberly J.. University of North Carolina Greensboro; Estados UnidosFil: Laungani, Ramesh. Poly Prep Country Day School; Estados UnidosFil: MacDougall, Andrew. University of Guelph; CanadáFil: Smith, Nicholas G.. Texas Tech University; Estados UnidosFil: Stevens, Carly J.. Lancaster University; Reino UnidoFil: Sullivan, Lauren L.. Michigan State University; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Tedder, Michelle. University of KwaZulu-Natal; SudáfricaFil: Peri, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Santa Cruz. Universidad Tecnológica Nacional. Facultad Regional Santa Cruz. Centro de Investigaciones y Transferencia de Santa Cruz. Universidad Nacional de la Patagonia Austral. Centro de Investigaciones y Transferencia de Santa Cruz; ArgentinaFil: Tognetti, Pedro Maximiliano. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Veen, Ciska. Netherlands Institute of Ecology; Países BajosFil: Wheeler, George. University of Nebraska-Lincoln; Estados UnidosFil: Young, Alyssa L.. University of North Carolina Greensboro; Estados UnidosFil: Young, Hillary. University of California; Estados UnidosFil: Borer, Elizabeth. University of Minnesota; Estados Unido