Studying engaged learning in online communities

Workshop paper presented at the International Conference of the Learning Sciences, ICLS '06, Bloomington, IN. Retrieved July 18, 2007 from http://www.cis.drexel.edu/faculty/gerry/pub/icls2006eloc.pdf.In this interactive session, participants will think together about “live” issues in the study of online communities as environments in which engaged learning can take place. Specifically, (a) What can we learn from contrasting cases of engaged learning in online communities? (b) Given differing methods, questions, timescales, grain sizes, philosophical orientations, and site contexts, how might generalizability of findings be ensured? (c) What do researchers need in order to develop a coherent theory of learning

An Approach for Assessing the Signature Quality of Various Chemical Assays when Predicting the Culture Media Used to Grow Microorganisms

We demonstrate an approach for assessing the quality of a signature system designed to predict the culture medium used to grow a microorganism. The system was comprised of four chemical assays designed to identify various ingredients that could be used to produce the culture medium. The analytical measurements resulting from any combination of these four assays can be used in a Bayesian network to predict the probabilities that the microorganism was grown using one of eleven culture media. We evaluated combinations of the signature system by removing one or more of the assays from the Bayes network. We measured and compared the quality of the various Bayes nets in terms of fidelity, cost, risk, and utility, a method we refer to as Signature Quality Metric

Methods of negotiation in online collaborative mathematics problem-solving

The Virtual Math Teams (VMT) project is an NSF-funded research program through which researchers at the College of Information Science and Technology (IST) and the Math Forum investigate the innovative use of online collaborative environments to support effective K-12 mathematics learning. Negotiation is an indispensable element in collaboration, especially in the resolution of situations whose complexity is such that understanding them is enhanced by multiple perspectives made possible through collaboration. Some mathematics problems which are described as ‘ill-structured’ because they admit of several possible interpretations and multiple solutions, are candidates for collaborative problem-solving. Negotiation is necessary to make this collaborative approach possible, inasmuch as sense- and meaning-making associated with this particular approach to problem-solving has for its distinctive characteristic, the dynamics of a group rather than the jig-saw style of cooperating individuals. A research methodology based on conversation analysis is used to identify how negotiation is conducted in online mathematics problem-solving by locating its methods as negotiation is initiated, processed and concluded. Initial findings show: - how changes in the tempo of turn-taking indicate shifts in the conduct of problem-solving, - how repetition and ‘forced conclusions’ are used to negotiate a choice among several problems at hand, - how intervals and transitions are used by participants to indicate preferred responses and responders, - how referencing tools impact negotiation. Findings from this research can assist in the design of CSCL environments, especially in the transformation of generic communication applications to collaborative technology

Virtual math teams (VMT): Continuity and sustainability of collaborative knowledge building

How can we support online groups to better sustain their collaborative learning activity over time? In this poster, we present a qualitative case study of group creativity online in the domain of mathematics. We define collaborative learning work broadly, ranging from the micro-level co-construction of novel resources for collective problem solving to the innovative reuse and expansion of ideas across multiple virtual teams. Based on our analysis of the collaborative interactions of five virtual math teams we characterize the relationship between "synchronic" aspects of collaborative knowledge building (i.e. single episode interactions) and their "diachronic" evolution across time and across collectivities. Our analysis indicates that the synergy between these two types of interactions and the resulting creative engagement of the teams relies on three fundamental processes: (1) referencing and the “configuration of indexicals”, (2) collective remembering, and (3) bridging across discontinuities. In addition we also reflect on the aspects of the online environment used by these virtual teams which promote, support or hinder diachronic and synchronic interactions leading to successful knowledge building

Imaging features and safety and efficacy of endovascular stroke treatment: a meta-analysis of individual patient-level data

Background: Evidence regarding whether imaging can be used effectively to select patients for endovascular thrombectomy (EVT) is scarce. We aimed to investigate the association between baseline imaging features and safety and efficacy of EVT in acute ischaemic stroke caused by anterior large-vessel occlusion. Methods: In this meta-analysis of individual patient-level data, the HERMES collaboration identified in PubMed seven randomised trials in endovascular stroke that compared EVT with standard medical therapy, published between Jan 1, 2010, and Oct 31, 2017. Only trials that required vessel imaging to identify patients with proximal anterior circulation ischaemic stroke and that used predominantly stent retrievers or second-generation neurothrombectomy devices in the EVT group were included. Risk of bias was assessed with the Cochrane handbook methodology. Central investigators, masked to clinical information other than stroke side, categorised baseline imaging features of ischaemic change with the Alberta Stroke Program Early CT Score (ASPECTS) or according to involvement of more than 33% of middle cerebral artery territory, and by thrombus volume, hyperdensity, and collateral status. The primary endpoint was neurological functional disability scored on the modified Rankin Scale (mRS) score at 90 days after randomisation. Safety outcomes included symptomatic intracranial haemorrhage, parenchymal haematoma type 2 within 5 days of randomisation, and mortality within 90 days. For the primary analysis, we used mixed-methods ordinal logistic regression adjusted for age, sex, National Institutes of Health Stroke Scale score at admission, intravenous alteplase, and time from onset to randomisation, and we used interaction terms to test whether imaging categorisation at baseline modifies the association between treatment and outcome. This meta-analysis was prospectively designed by the HERMES executive committee but has not been registered. Findings: Among 1764 pooled patients, 871 were allocated to the EVT group and 893 to the control group. Risk of bias was low except in the THRACE study, which used unblinded assessment of outcomes 90 days after randomisation and MRI predominantly as the primary baseline imaging tool. The overall treatment effect favoured EVT (adjusted common odds ratio [cOR] for a shift towards better outcome on the mRS 2·00, 95% CI 1·69–2·38; p<0·0001). EVT achieved better outcomes at 90 days than standard medical therapy alone across a broad range of baseline imaging categories. Mortality at 90 days (14·7% vs 17·3%, p=0·15), symptomatic intracranial haemorrhage (3·8% vs 3·5%, p=0·90), and parenchymal haematoma type 2 (5·6% vs 4·8%, p=0·52) did not differ between the EVT and control groups. No treatment effect modification by baseline imaging features was noted for mortality at 90 days and parenchymal haematoma type 2. Among patients with ASPECTS 0–4, symptomatic intracranial haemorrhage was seen in ten (19%) of 52 patients in the EVT group versus three (5%) of 66 patients in the control group (adjusted cOR 3·94, 95% CI 0·94–16·49; pinteraction=0·025), and among patients with more than 33% involvement of middle cerebral artery territory, symptomatic intracranial haemorrhage was observed in 15 (14%) of 108 patients in the EVT group versus four (4%) of 113 patients in the control group (4·17, 1·30–13·44, pinteraction=0·012). Interpretation: EVT achieves better outcomes at 90 days than standard medical therapy across a broad range of baseline imaging categories, including infarcts affecting more than 33% of middle cerebral artery territory or ASPECTS less than 6, although in these patients the risk of symptomatic intracranial haemorrhage was higher in the EVT group than the control group. This analysis provides preliminary evidence for potential use of EVT in patients with large infarcts at baseline. Funding: Medtronic

The Changing Landscape for Stroke\ua0Prevention in AF: Findings From the GLORIA-AF Registry Phase 2

Background GLORIA-AF (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation) is a prospective, global registry program describing antithrombotic treatment patterns in patients with newly diagnosed nonvalvular atrial fibrillation at risk of stroke. Phase 2 began when dabigatran, the first non\u2013vitamin K antagonist oral anticoagulant (NOAC), became available. Objectives This study sought to describe phase 2 baseline data and compare these with the pre-NOAC era collected during phase 1. Methods During phase 2, 15,641 consenting patients were enrolled (November 2011 to December 2014); 15,092 were eligible. This pre-specified cross-sectional analysis describes eligible patients\u2019 baseline characteristics. Atrial fibrillation disease characteristics, medical outcomes, and concomitant diseases and medications were collected. Data were analyzed using descriptive statistics. Results Of the total patients, 45.5% were female; median age was 71 (interquartile range: 64, 78) years. Patients were from Europe (47.1%), North America (22.5%), Asia (20.3%), Latin America (6.0%), and the Middle East/Africa (4.0%). Most had high stroke risk (CHA2DS2-VASc [Congestive heart failure, Hypertension, Age  6575 years, Diabetes mellitus, previous Stroke, Vascular disease, Age 65 to 74 years, Sex category] score  652; 86.1%); 13.9% had moderate risk (CHA2DS2-VASc = 1). Overall, 79.9% received oral anticoagulants, of whom 47.6% received NOAC and 32.3% vitamin K antagonists (VKA); 12.1% received antiplatelet agents; 7.8% received no antithrombotic treatment. For comparison, the proportion of phase 1 patients (of N = 1,063 all eligible) prescribed VKA was 32.8%, acetylsalicylic acid 41.7%, and no therapy 20.2%. In Europe in phase 2, treatment with NOAC was more common than VKA (52.3% and 37.8%, respectively); 6.0% of patients received antiplatelet treatment; and 3.8% received no antithrombotic treatment. In North America, 52.1%, 26.2%, and 14.0% of patients received NOAC, VKA, and antiplatelet drugs, respectively; 7.5% received no antithrombotic treatment. NOAC use was less common in Asia (27.7%), where 27.5% of patients received VKA, 25.0% antiplatelet drugs, and 19.8% no antithrombotic treatment. Conclusions The baseline data from GLORIA-AF phase 2 demonstrate that in newly diagnosed nonvalvular atrial fibrillation patients, NOAC have been highly adopted into practice, becoming more frequently prescribed than VKA in Europe and North America. Worldwide, however, a large proportion of patients remain undertreated, particularly in Asia and North America. (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients With Atrial Fibrillation [GLORIA-AF]; NCT01468701

Literary studies and the academy

In 1885 the University of Oxford invited applications for the newly created Merton Professorship of English Language and Literature. The holder of the chair was, according to the statutes, to ‘lecture and give instruction on the broad history and criticism of English Language and Literature, and on the works of approved English authors’. This was not in itself a particularly innovatory move, as the study of English vernacular literature had played some part in higher education in Britain for over a century. Oxford University had put English as a subject into its pass degree in 1873, had been participating since 1878 in extension teaching, of which literary study formed a significant part, and had since 1881 been setting special examinations in the subject for its non-graduating women students. What was new was the fact that this ancient university appeared to be on the verge of granting the solid academic legitimacy of an established chair to an institutionally marginal and often contentious intellectual pursuit, acknowledging the study of literary texts in English to be a fit subject not just for women and the educationally disadvantaged but also for university men

Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTIC‐HF: baseline characteristics and comparison with contemporary clinical trials

Aims: The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTIC‐HF) trial. Here we describe the baseline characteristics of participants in GALACTIC‐HF and how these compare with other contemporary trials. Methods and Results: Adults with established HFrEF, New York Heart Association functional class (NYHA) ≥ II, EF ≤35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokinetic‐guided dosing: 25, 37.5 or 50 mg bid). 8256 patients [male (79%), non‐white (22%), mean age 65 years] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NT‐proBNP 1971 pg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTIC‐HF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressure < 100 mmHg (n = 1127), estimated glomerular filtration rate < 30 mL/min/1.73 m2 (n = 528), and treated with sacubitril‐valsartan at baseline (n = 1594). Conclusions: GALACTIC‐HF enrolled a well‐treated, high‐risk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation

Diversity in Virtual Math Teams

Abstract: We are investigating how digital libraries can be used collaboratively by teams of students to engage in problem solving of school mathematics. We are experimenting with procedures for matching students who come to the mathforum.org digital library site to form effective collaborative learning online teams. Our hypothesis is that group learning will be greatest in groups that carefully combine diverse perspectives and backgrounds. We are investigating how to design curriculum, community practices and groupware support to foster deep learning of math. In the first half year of this fiveyear research project, we have generated the following pilot studies: 14 videotaped sessions in middle school and university classrooms and 33 online chat sessions among researchers, college students or K-12 students. In analyzing these studies, we will embrace a diversity of learning science methodologies within a design research paradigm