Towards a constructivist grammar curriculum for the United States

The author argues that educators must forge an alternative method to teaching grammar: the explicit, constructivist teaching of grammar within the meaningful context of a writing curriculum

The additive group of a Lie nilpotent associative ring

Let Z be the free unitary associative ring freely generated by an infinite countable set X = {x_1, x_2,...}. Define a left-normed commutator [x_1, x_2, ..., x_n] by [a,b] = ab - ba, [a,b,c] = [[a,b],c]. For n \ge 2, let T^(n) be the ideal in Z generated by all commutators [a_1,a_2,..., a_n] (a_i \in Z). It can be easily seen that the additive group of the quotient ring Z /T^(2) is a free abelian group. Recently Bhupatiraju, Etingof, Jordan, Kuszmaul and Li have noted that the additive group of Z /T^(3) is free abelian as well. In the present note we show that this is not the case for Z /T^(4). More precisely, let T^(3,2) be the ideal in Z generated by T^(4) together with all elements [a_1, a_2, a_3][a_4, a_5] (a_i \in Z). We prove that T^(3,2)/T^(4) is a non-trivial elementary abelian 3-group and the additive group of Z /T^(3,2) is free abelian.Comment: 13 pages. Proposition 1.5, Remarks 1.6 and 2.3 and some references adde

Hybrid Vigor: Securing Venture Capital by Spanning Categories in Nanotechnology

This study develops and tests a set of novel theoretical predictions about the conditions under which category spanning is rewarded by external audiences. To do this, we revisit the assumption that comprehensible organizational identities are associated with individual categories. Drawing on insights from cognitive psychology, we suggest that category spanning does not necessarily lead to confusion, but, rather, to interpretations that rely on a “header–modifier” structure where one category anchors cognition but is modified by features of the other. Audiences may have clear understandings about how categories fit together and cognate schema for evaluating firms that hybridize by spanning between them. An empirical examination of venture capital in the carbon nanotechnology industry supports our approach: start-ups were rewarded or punished for hybridization contingent on how they mixed “science” and “technology” in their patents, top management team, and collaborations. As such, we show that the category a firm starts in, how it hybridizes, and the degree to which this affects core versus peripheral identity markers may all affect how it is perceived

Primary total knee arthroplasty in a patient with a chronic extensor mechanism deficiency

AbstractA 44-year-old female presented with a chief complaint of left knee pain and dysfunction. The patient had a complex surgical history including patellar fracture repair, subsequent patellar ligament repair, and ultimately allograft reconstruction which was complicated by septic arthritis requiring graft resection. On presentation to our clinic, she was noted to have significant degenerative disease in addition to chronic extensor mechanism deficiency. She underwent primary total knee arthroplasty with concomitant tibial tubercle osteotomy and advancement. The patient has had an excellent result postoperatively including return of full range of motion without residual extensor lag

Timely Linkage of Individuals to Substance Use Disorder Treatment: Development, Implementation, and Evaluation of FindHelpNowKY.org

Background: Substance use disorders (SUD) have steadily increased over the last two decades. Seeking SUD treatment involves searching SUD treatment facility types (inpatient, outpatient and intensive outpatient, residential and family residential, and detoxification facilities) that offer specialized SUD treatment depending on individual needs and preferences. Referrals to SUD treatment require innovative strategies that rapidly link individuals to SUD treatment when they are at the critical stage of readiness. The aim of this study was to develop, implement, and evaluate a user-friendly SUD treatment facility opening availability website called FindHelpNowKY.org. The objectives of the study were to 1) recruit SUD treatment facility and partner participation; 2) develop platform, content, and analytics for the FindHelpNowKY.org website intervention with an information repository; 3) assess barriers and facilitators to implementation; and 4) evaluate the development and implementation of FindHelpNowKY.org. Methods: Website development stakeholders were identified and the website concept was developed. The logic model for FindHelpNowKY.org outlined resources, activities, and outputs as well as the associated short-term, medium-term, and long-term objectives, along with a website evaluation plan. Website usability and focus group testing was conducted. Information repository resource documents were compiled and categorized. An inventory of Kentucky-based SUD treatment facilities was compiled using various state and federal resources. Results: Development/implementation barriers were addressed, facilitators were identified, and the website was implemented; 83% of SUD treatment facilities were indexed on the website, and average website user time was 7 min. From February to October 2018, there were 29,000 visitors, and 30,000 unique searches. The most common website query was a friend or family member seeking long-term residential or outpatient treatment facilities accepting Medicaid or Medicare. Conclusions: FindHelpNowKY.org has the potential to fill a critical need for timely access to available SUD treatment in the state. The website may be a valuable resource for health professionals that can enhance clinical workflow and reduce staff time conducting phone and website searches for available SUD treatment. The website is a promising tool for assessing current SUD treatment capacity vs. SUD treatment need. The FindHelpNow model can be used by other states to increase timely access to SUD treatment

Regularized Maximum Likelihood Image Synthesis and Validation for ALMA Continuum Observations of Protoplanetary Disks

Regularized Maximum Likelihood (RML) techniques are a class of image synthesis methods that achieve better angular resolution and image fidelity than traditional methods like CLEAN for sub-mm interferometric observations. To identify best practices for RML imaging, we used the GPU-accelerated open source Python package MPoL, a machine learning-based RML approach, to explore the influence of common RML regularizers (maximum entropy, sparsity, total variation, and total squared variation) on images reconstructed from real and synthetic ALMA continuum observations of protoplanetary disks. We tested two different cross-validation (CV) procedures to characterize their performance and determine optimal prior strengths, and found that CV over a coarse grid of regularization strengths easily identifies a range of models with comparably strong predictive power. To evaluate the performance of RML techniques against a ground truth image, we used MPoL on a synthetic protoplanetary disk dataset and found that RML methods successfully resolve structures at fine spatial scales present in the original simulation. We used ALMA DSHARP observations of the protoplanetary disk around HD 143006 to compare the performance of MPoL and CLEAN, finding that RML imaging improved the spatial resolution of the image by up to a factor of 3 without sacrificing sensitivity. We provide general recommendations for building an RML workflow for image synthesis of ALMA protoplanetary disk observations, including effective use of CV. Using these techniques to improve the imaging resolution of protoplanetary disk observations will enable new science, including the detection of protoplanets embedded in disks.Comment: 27 pages, 12 figures, accepted for publication in PAS

Basin-scale inputs of cobalt, iron, and manganese from the Benguela-Angola front to the South Atlantic Ocean

Author Posting. © Association for the Sciences of Limnology and Oceanography, 2012. This article is posted here by permission of Association for the Sciences of Limnology and Oceanography for personal use, not for redistribution. The definitive version was published in Limnology and Oceanography 57 (2012): 989-1010, doi:10.4319/lo.2012.57.4.0989.We present full-depth zonal sections of total dissolved cobalt, iron, manganese, and labile cobalt from the South Atlantic Ocean. A basin-scale plume from the African coast appeared to be a major source of dissolved metals to this region, with high cobalt concentrations in the oxygen minimum zone of the Angola Dome and extending 2500 km into the subtropical gyre. Metal concentrations were elevated along the coastal shelf, likely due to reductive dissolution and resuspension of particulate matter. Linear relationships between cobalt, N2O, and O2, as well as low surface aluminum supported a coastal rather than atmospheric cobalt source. Lateral advection coupled with upwelling, biological uptake, and remineralization delivered these metals to the basin, as evident in two zonal transects with distinct physical processes that exhibited different metal distributions. Scavenging rates within the coastal plume differed for the three metals; iron was removed fastest, manganese removal was 2.5 times slower, and cobalt scavenging could not be discerned from water mass mixing. Because scavenging, biological utilization, and export constantly deplete the oceanic inventories of these three hybrid-type metals, point sources of the scale observed here likely serve as vital drivers of their oceanic cycles. Manganese concentrations were elevated in surface waters across the basin, likely due to coupled redox processes acting to concentrate the dissolved species there. These observations of basin-scale hybrid metal plumes combined with the recent projections of expanding oxygen minimum zones suggest a potential mechanism for effects on ocean primary production and nitrogen fixation via increases in trace metal source inputs.This research was supported US National Science Foundation Chemical Oceanography (Division of Ocean Sciences OCE-0452883, OCE-0752291, OCE-0928414, OCE-1031271), the Center for Microbial Research and Education, the Gordon and Betty Moore Foundation, the WHOI Coastal Ocean Institute, and the WHOI Ocean Life Institute

Preliminary Research on a COVID-19 Test Strategy to Guide Quarantine Interval in University Students

Following COVID-19 exposure, the Centers for Disease Control (CDC) recommends a 10–14-day quarantine for asymptomatic individuals and more recently a 7-day quarantine with a negative PCR test. A university-based prospective cohort study to determine if early polymerase chain reaction (PCR) negativity predicts day 14 negativity was performed. A total of 741 asymptomatic students in quarantine was screened and 101 enrolled. Nasopharyngeal swabs were tested on days 3 or 4, 5, 7, 10, and 14, and the proportion of concordant negative results for each day versus day 14 with a two-sided 95% exact binomial confidence interval was determined. Rates of concordant negative test results were as follows: day 5 vs. day 14 = 45/50 (90%, 95% CI: 78–97%); day 7 vs. day 14 = 47/52 (90%, 95% CI: 79–97%); day 10 vs. day 14 = 48/53 (91%, 95% CI:79–97%), with no evidence of different negative rates between earlier days and day 14 by McNemar’s test, p \u3e 0.05. Overall, 14 of 90 (16%, 95% CI: 9–25%) tested positive while in quarantine, with seven initial positive tests on day 3 or 4, 5 on day 5, 2 on day 7, and none on day 10 or 14. Based on concordance rates between day 7 and 14, we anticipate that 90% (range: 79–97%) of individuals who are negative on day 7 will remain negative on day 14, providing the first direct evidence that exposed asymptomatic students ages 18–44 years in a university setting are at low risk if released from quarantine at 7 days if they have a negative PCR test prior to release. In addition, the 16% positive rate supports the ongoing need to quarantine close contacts of COVID-19 cases

The Structure of Episodic Memory: Ganeri's ‘Mental Time Travel and Attention’

We offer a framework for assessing what the structure of episodic memory might be, if one accepts the Buddhist denial of persisting selves. This paper is a response to Jonardon Ganeri's paper "Mental time travel and attention", which explores Buddhaghosa's ideas about memory. (It will eventually be published with a reply by Ganeri)