On Teaching Palindromes

Webster\u27s Third New International Dictionary defines palindrome as a word, verse, or sentence that reads the same backward as forward . As is often the case with limericks, sonnets, and other highly-structured but nowadays seldom-pursued literary creations, the few frequently-anthologized examples have come to be the only examples we know. This is certainly the case with the palindrome

For Some Reason Cheese

I don\u27t propose to explain it. Cheese is as unlikely as it is likely: a seemingly ordinary food product. Why, then, do we find it treated more thoroughly in palindromes than any other substance? This enigma functions as a perfect metaphor for the whole subject of palindromes, full of eerie truths (Tessa\u27s in Italy: Latin is asset) and bizarre images (Satan, oscillate my metallic sonatas)

Student Discourse and Problem Solving in a High School Mathematics Classroom

The purpose of this study was to explore the problem-solving process and discourse in three high school Algebra 2 classes and analyze how discourse might be used to facilitate the problem-solving process. High school Algebra 2 students in this study were asked to engage in discourse with their peers in order to reach conclusions in open-ended problem-solving tasks. The teacher acted as the facilitator and encouraged students to act as the mathematical authorities. On two different days, students were given two different real-life problem-solving tasks and asked to reach possible conclusions to those tasks. Three research questions guided the study: the role of discourse in the problem-solving process, the role of the teacher in discourse, and students’ perceptions of discourse. The study found that students who were engaged in the discourse had the opportunity to use discourse as a part of the problem-solving process. The teacher had a role in creating a classroom environment focused on discourse, creating appropriate tasks, and facilitating student discourse. While some students did not engage in the discourse process or think the discourse process was helpful for their understanding, many students stated their learning was enhanced because they were able to hear from a variety of perspectives

Intense field stabilization in circular polarization: 3D time-dependent dynamics

We investigate the stabilization of a hydrogen atom in circularly polarized laser fields. We use a time-dependent, fully three dimensional approach to study the quantum dynamics of the hydrogen atom subject to high intensity, short wavelength laser pulses. We find enhanced survival probability as the field is increased under fixed envelope conditions. We also confirm wavepacket dynamics seen in prior time-dependent computations restricted to two dimensions.Comment: 4 pages, 3 figures, submitte

Seed production of barnyardgrass (Echinochloa crus-galli) in response to time of emergence in cotton and rice

The spread of herbicide resistance in barnyardgrass (Echinochloa crus-galli (L.) Beauv.) poses a serious threat to crop production in the southern United States. A thorough knowledge of the biology of barnyardgrass is fundamental for designing effective resistance-management programmes. In the present study, seed production of barnyardgrass in response to time of emergence was investigated in cotton and rice, respectively, in Fayetteville and Rohwer, Arkansas, over a 2-year period (2008–09). Barnyardgrass seed production was greater when seedlings emerged with the crop, but some seed production was observed even if seedlings emerged several weeks after crop emergence. Moreover, barnyardgrass seed production was highly variable across environments. When emerging with the crop (0 weeks after crop emergence (WAE)), barnyardgrass produced c. 35 500 and 16 500 seeds/plant in cotton, and c. 39 000 and 2900 seeds/plant in rice, in 2008 and 2009, respectively. Seed production was observed when seedlings emerged up to 5 WAE (2008) or 7 WAE (2009) in cotton and up to 5 WAE (2008, 2009) in rice; corresponding seed production was c. 2500 and 1500 seeds/plant in cotton, and c. 14 700 and 110 seeds/plant in rice, in 2008 and 2009, respectively. The results suggest that cultural approaches that delay the emergence of barnyardgrass or approaches that make the associated crop more competitive will be useful in integrated management programmes. In the context of herbicide resistance management, it may be valuable to prevent seed return to the seedbank, irrespective of cohorts. The findings are vital for parameterizing herbicide resistance simulation models for barnyardgrass

The Great Debate Between John W. Ring and J. W. Chism

https://digitalcommons.acu.edu/crs_books/1094/thumbnail.jp

Using Cover Crops to Suppress Weeds and Improve Soil Health

Herbicide-resistant weeds are creating challenges for producers to control weeds in crop fields. This study explores the potential of cover crops to reduce weed pressure and im­prove soil health. Cover crops were planted after corn harvest in tilled and no-till fields, and included Graza radish, winter wheat, annual ryegrass, spring oats, winter oats, and forage collards. The control was fallow with herbicide application but no cover crop. Soil health was determined prior to cover crop termination. Graza radish and forage collards did not grow consistently in all plots due to poor germination and winter kill. Significant weed biomass was produced in the fallow plot or in plots with poor cover crop stands. Microbial biomass was much greater in the no-till field than in the tilled fields

Using Cover Crops as an Effective Weed Control Method in Southeast Kansas

Weed control is important to optimize crop production. This study was conducted to compare the effectiveness of different methods of fall-implemented weed control strategies. These strategies included different cover crop mixes, chemical control, and mechanical control. The cover crop mixes included four different commonly-planted winter cover crops. The chemical control was a fall-applied burndown, and the me­chanical control was vertical tillage. We found cover crop mixes that contained cereal rye provided the most weed control, with the chemical control being a close second. Spring oats die during the winter because of the low temperatures. The three cover crop mixes containing spring oats still provided 50% reduction in weed biomass the follow­ing spring. However, the fall tillage increased the amount of weed biomass

Quantitative single cell determination of ERK phosphorylation and regulation in relapsed and refractory primary acute myeloid leukemia

: We investigated the constitutive activation of the MEK/ERK pathway in acute myelogenous leukemia (AML) via a flow cytometric technique to quantitate expression of phosphorylated ERK (p-ERK). A total of 42 AML samples (16 newly diagnosed, 26 relapsed/refractory) were analyzed. Normal bone marrow CD34+ cells (n = 10) had little or no expression of p-ERK, while G-CSF-mobilized CD34+ cells exhibited enhanced p-ERK levels. Markedly elevated p-ERK levels were found in 83.3% of the AML samples, with no differences observed between the newly diagnosed and relapsed/refractory samples. Treatment with a MEK inhibitor resulted in significantly decreased p-ERK levels in both the newly diagnosed and relapsed/refractory samples, which was associated with growth arrest, but not apoptosis induction. In summary, we defined conditions for the analysis of MAPK signaling in primary AML samples. Normal CD34+ cells expressed very low levels of p-ERK, and increased p-ERK levels were found in normal G-CSF-stimulated circulating CD34+ cells. Constitutively high p-ERK levels observed in the majority of AML samples suggest deregulation of this pathway that appears to be independent of disease status. The ability of ERK inhibition to promote growth arrest rather than apoptosis suggests that clinical trials of MEK/ERK inhibitors may be more effective when combined with chemotherapy