55 research outputs found
Representational decisions when learning population dynamics with an instructional simulation
DEMIST is a multi-representational simulation environment that supports understanding of the representations and concepts of population dynamics. We report on a study with 18 subjects with little prior knowledge that explored if DEMIST could support their learning and asked what decisions learners would make about how to use the many representations that DEMIST provides. Analysis revealed that using DEMIST for one hour significantly improved learners' understanding of population dynamics though their knowledge of the relation between representations remained weak. It showed that learners used many of DEMIST's features. For example, they investigated the majority of the representational space, used dynalinking to explore the relation between representations and had preferences for representations with different computational properties. It also revealed that decisions made by designers impacted upon what is intended to be a free discovery environment
Coexisting high-grade glandular and squamous cervical lesions and human papillomavirus infections
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144469.pdf (publisher's version ) (Closed access)The frequency of high-risk human papillomavirus (hr-HPV) genotypes in patients with adenocarcinoma in situ (ACIS) with coexisting cervical intraepithelial neoplasia (CIN), ACIS without coexisting CIN, and high-grade CIN (CIN II/III) was studied, in order to gain more insight into the relation between hr-HPV infections and the development of coexisting squamous and glandular lesions. The SPF(10) LiPA PCR was used to detect simultaneously 25 different HPV genotypes in biopsies obtained from 90 patients with CIN II/III, 47 patients with ACIS without coexisting CIN, and 49 patients with ACIS and coexisting CIN. hr-HPV was detected in 84 patients (93%) with CIN II/III, 38 patients (81%) with ACIS without CIN, and in 47 patients (96%) with ACIS and coexisting CIN. A total of 13 different hr-HPV genotypes were detected in patients with CIN II/III, and only five in patients with ACIS with/without coexisting CIN. HPV 31, multiple hr-HPV genotypes, and HPV genotypes other than 16, 18, and 45 were significantly more often detected in patients with CIN II/III, while HPV 18 was significantly more often detected in patients with ACIS with/without CIN. There were no significant differences in the frequency of specific hr-HPV genotypes between patients with ACIS with or without coexisting CIN. In conclusion, the frequency of specific hr-HPV genotypes is similar for patients with ACIS without CIN and patients with ACIS and coexisting CIN, but is significantly different for patients with CIN II/III without ACIS. These findings suggest that squamous lesions, coexisting with high-grade glandular lesions, are aetiologically different from squamous lesions without coexisting glandular lesions
Alveolar macrophage-derived type I interferons orchestrate innate immunity to RSV through recruitment of antiviral monocytes
Type I interferons (IFNs) are important for host defense from viral infections, acting to restrict viral production in infected cells and to promote antiviral immune responses. However, the type I IFN system has also been associated with severe lung inflammatory disease in response to respiratory syncytial virus (RSV). Which cells produce type I IFNs upon RSV infection and how this directs immune responses to the virus, and potentially results in pathological inflammation, is unclear. Here, we show that alveolar macrophages (AMs) are the major source of type I IFNs upon RSV infection in mice. AMs detect RSV via mitochondrial antiviral signaling protein (MAVS)–coupled retinoic acid–inducible gene 1 (RIG-I)–like receptors (RLRs), and loss of MAVS greatly compromises innate immune restriction of RSV. This is largely attributable to loss of type I IFN–dependent induction of monocyte chemoattractants and subsequent reduced recruitment of inflammatory monocytes (infMo) to the lungs. Notably, the latter have potent antiviral activity and are essential to control infection and lessen disease severity. Thus, infMo recruitment constitutes an important and hitherto underappreciated, cell-extrinsic mechanism of type I IFN–mediated antiviral activity. Dysregulation of this system of host antiviral defense may underlie the development of RSV-induced severe lung inflammation
The effects of representational format on learning combinatorics from an interactive computer simulation
Mixed Acylals - Synthesis of Alkylidene Carboxylate Formates
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27543.pdf (publisher's version ) (Open Access
Somewhere Between CAAD-past and -future. is this where practise is?
Computers are commonplace in architecture: as CAD for drawing production, special text databases for specification writing and software for construction budget calculation. Far less common is their application in the earlier stages of design. This article discusses the options available to the architect and facility planner. The bottomline is that there are many lowkeyed tools around that can serve any practice very weel
Strategies for CAAD Education - the Singapore Way
For over one year (1985/86) the author was as senior lecturer instrumental in developing and initiating a CAAD-curriculum at the Singapore School of Architecture. The paper describes the circumstances surrounding the acquisition of the Schools'large CAD-system, the CAAD-curriculum proposals, and the first pilot courses. On the basis of this preliminary experience some observations for CAAD-teaching are made, which are related to more universal strategies for CAAD-education
International Implementation of a CAAD Project in Schools of Architecture
With funding from the European Cultural Committee, work is in hand to develop a modular course structure which will promote CAAD education in Schools of Architecture throughout Europe. The paper identifies the need for the course structure and describes the pilot work jointly carried out by the University of Strathclyde and the Technical University of Delft. The course structure proposed in the paper will be the focus of discussion and elaboration at the meeting of European Schools of Architectur
Stability Constants for Mono- and Dioxalato-complexes of Y and the REE, Potentially Important Species in Groundwaters and Surface Freshwaters
We present the first measured set of stability constants for mono- and dioxalato-complexes of yttrium and all rare earths except Pm (Y+REE), Oxβn = [MOxn3−2n] [M3+]−1 [Ox2−]−n(where [ ] ≡ concentrations, M ≡ Y+REE, and Ox2− ≡ C2O42−). Aqueous solutions of Y+REE were titrated with oxalic acid in the presence of a cation-exchange resin, and Y+REE concentrations in the solution phase were measured by ICP-MS. This method allows investigation of all Y+REE simultaneously under identical conditions and is thus very sensitive to subtle inter-element variations in log Oxβn. Experiments were performed at a single ionic strength (I = 0.05 M), but at two values of pH. Patterns of log Oxβ1 and log Oxβ2, determined from our experiments, are similar in shape and reminiscent of those for carbonato-complexes. The average ratio of stepwise stability constants K2/K1 = Oxβ2/(Oxβ1)2 is 0.05 ± 0.02 for Y+REE excluding La and Ce.
Literature values of Oxβ1(Eu) for 0.03 mol/L ≤ I ≤ 1 mol/L were used to derive the relation log Oxβ1(Eu) = log Oxβ10(Eu) − 6.132√I/(1 + 1.47√I) + 0.902I, where log Oxβ10(Eu) is the stability constant at infinite dilution. Applying this relation to all Y+REE, the following values of log Oxβ10 (at zero ionic strength) were found: 6.66 (Y), 5.87 (La), 5.97 (Ce), 6.25 (Pr), 6.31 (Nd), 6.43 (Sm), 6.52 (Eu), 6.53 (Gd), 6.63 (Tb), 6.74 (Dy), 6.77 (Ho), 6.83 (Er), 6.89 (Tm), 6.95 (Yb), 6.96 (Lu). These values, which are based on direct measurements for each individual Y+REE, agree quite well with published extrapolations that are mostly based on linear free-energy relationships.
Total oxalate concentrations of 10−5−10−3 M have been reported for soil solutions. Free oxalate ions persist at much lower pH than free carbonate ions and a simple speciation model demonstrates that oxalato-complexes can dominate Y+REE speciation in mildly acidic groundwaters of low-to-moderate alkalinity
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