4,387 research outputs found

    Pictorial Socratic dialogue and conceptual change

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    Counter-examples used in a Socratic dialogue aim to provoke reflection to effect conceptual changes. However, natural language forms of Socratic dialogues have their limitations. To address this problem, we propose an alternative form of Socratic dialogue called the pictorial Socratic dialogue. A Spring Balance System has been designed to provide a platform for the investigation of the effects of this pedagogy on conceptual changes. This system allows learners to run and observe an experiment. Qualitative Cartesian graphs are employed for learners to represent their solutions. Indirect and intelligent feedback is prescribed through two approaches in the pictorial Socratic dialogue which aim to provoke learners probe through the perceptual structural features of the problem and solution, into the deeper level of the simulation where Archimedes’ Principle governs

    Cross-Boundary Stewardship for Wetland Integrity and Resilience in the Greater Rocky Mountain National Park Ecosystem

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    Approximately half of the wetlands in Rocky Mountain National Park (RMNP) are degraded due to human disturbances that often occur beyond park boundaries. Like most protected areas, RMNP is part of a larger ecosystem with critical connections to surrounding lands. Therefore, more effective stewardship of wetlands within RMNP is likely to be achieved through cross-boundary cooperative efforts. Through interviews with wetland stewardship agencies and organizations and an analysis of their wetland plans and policies, barriers and opportunities for cross-boundary stewardship were identified, as well as common structures used to facilitate work across boundaries. Wetlands outside of RMNP are experiencing similar impact across boundaries as those within the park. Though participants recognize that working cooperatively with neighboring entities can benefit wetlands, they also reported that the most significant cross-boundary challenge is working with others. Despite these challenges, many entities in the greater RMNP ecosystem have found ways to work together. We defined three types of cooperative interactions - communication, coordination, and collaboration - and developed a framework that describes elements of each type. Based on these findings and the framework presented, we provide recommendations on how to address cooperative management challenges, while taking advantage of opportunities to facilitate cross-boundary stewardship for wetland integrity at the ecosystem-scale

    Methods for local gravity field approximation

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    The most widely known modern method for estimating gravity field values from observed data is least-squares collocation. Its advantages are that it can make estimates at arbitrary locations based on irregularly spaced observations, and that it makes use of statistical information about errors in the input data while providing corresponding information about the quality of the output estimates. Disadvantages of collocation include the necessity of inverting square matrices of dimension equal to the number of data values and the need to assume covariance models for the gravity field and the data errors. Fourier methods are an important alternative to collocation; having the advantage of greater computational efficiency, but requiring data estimates to be on a regular grid and not using or providing statistical accuracy information. The GEOFAST algorithm is an implementation of collocation that achieves high computational efficiency by transforming the estimation equations into the frequency domain where an accurate approximation may be made to reduce the workload. The forward and inverse Fast Fourier Transforms (FFTs) are utilized. The accuracy and computational efficiency of the GEOFAST algorithm is demonstrated using two sets of synthetic gravity data: marine gravity for an ocean trench region including wavelengths longer than 200 km; and local land gravity containing wavelengths as short as 5 km. These results are discussed along with issues such as the advantages of first removing reference field models before carrying out the estimation algorithm

    Investigating a possible role for the bacterial signal molecules N-acylhomoserine lactones in Balanus improvisus cyprid settlement

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    Increased settlement on bacterial biofilms has been demonstrated for a number of marine invertebrate larvae, but the nature of the cue(s) responsible is not well understood. We tested the hypothesis that the bay barnacle Balanus improvisus utilizes the bacterial signal molecules N‐acylhomoserine lactones (AHLs) as a cue for the selection of sites for permanent attachment. Single species biofilms of the AHL‐producing bacteria Vibrio anguillarum, Aeromonas hydrophila and Sulfitobacter sp. BR1 were attractive to settling cypris larvae of B. improvisus. However, when AHL production was inactivated, either by mutation of the AHL synthetic genes or by expression of an AHL‐degrading gene (aiiA), the ability of the bacteria to attract cyprids was abolished. In addition, cyprids actively explored biofilms of E. coli expressing the recombinant AHL synthase genes luxI from Vibrio fischeri (3‐oxo‐C6‐HSL), rhlI from Pseudomonas aeruginosa (C4‐HSL/C6‐HSL), vanI from V. anguillarum (3‐oxo‐C10‐HSL) and sulI from Sulfitobacter sp. BR1 (C4‐HSL, 3‐hydroxy‐C6‐HSL, C8‐HSL and 3‐hydroxy‐C10‐HSL), but not E. coli that did not produce AHLs. Finally, synthetic AHLs (C8‐HSL, 3‐oxo‐C10‐HSL and C12‐HSL) at concentrations similar to those found within natural biofilms (5 ÎŒm) resulted in increased cyprid settlement. Thus, B. improvisus cypris exploration of and settlement on biofilms appears to be mediated by AHL‐signalling bacteria in the laboratory. This adds to our understanding of how quorum sensing inhibition may be used as for biofouling control. Nonetheless, the significance of our results for larvae settling naturally in the field, and the mechanisms that underlay the observed responses to AHLs, is as yet unknown

    SIMPle Dark Matter: Self-Interactions and keV Lines

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    We consider a simple supersymmetric hidden sector: pure SU(N) gauge theory. Dark matter is made up of hidden glueballinos with mass mXm_X and hidden glueballs with mass near the confinement scale Λ\Lambda. For mX∌1 TeVm_X \sim 1\,\text{TeV} and Λ∌100 MeV\Lambda \sim 100\,\text{MeV}, the glueballinos freeze out with the correct relic density and self-interact through glueball exchange to resolve small-scale structure puzzles. An immediate consequence is that the glueballino spectrum has a hyperfine splitting of order Λ2/mX∌10 keV\Lambda^2 / m_X \sim 10\,\text{keV}. We show that the radiative decays of the excited state can explain the observed 3.5 keV X-ray line signal from clusters of galaxies, Andromeda, and the Milky Way.Comment: v1: 6 pages, 2 figures; v2: added references, published version; v3: note adde

    Practical ideas to increase student motivation in the classroom

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    Motivation is a complex and multi-faceted psychological phenomenon that can hinder or enhance student performance both in and out of the classroom. However, despite its impact on learning, motivation is not often explicitly addressed in the teaching materials and resources that we use. This session then will begin with a brief explanation of some of the key concepts in L2 learner 
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    Phosphorylation of U24 from Human Herpes Virus type 6 (HHV-6) and its potential role in mimicking myelin basic protein (MBP) in multiple sclerosis

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    AbstractMyelin basic protein (MBP) from multiple sclerosis (MS) patients contains lower levels of phosphorylation at Thr97 than normal individuals. The significance of phosphorylation at this site is not fully understood, but it is proposed to play a role in the normal functioning of MBP. Human Herpesvirus Type 6 encodes the protein U24, which has tentatively been implicated in the pathology of MS. U24 shares a 7 amino acid stretch encompassing the Thr97 phosphorylation site of MBP: PRTPPPS. We demonstrate using a combination of mass spectrometry, thin layer chromatography and autoradiography, that U24 can be phosphorylated at the equivalent threonine. Phospho-U24 may confound signalling or other pathways in which phosphorylated MBP may participate, precipitating a pathological process.Structured summaryMINT-6613181:MAPK (uniprotkb:P28482) phosphorylates (MI:0217) MBP (uniprotkb:P02687) by protein kinase assay (MI:0424)MINT-6613171, MINT-6613190:MAPK (uniprotkb:P28482) phosphorylates (MI:0217) U24 (uniprotkb:Q69559) by protein kinase assay (MI:0424

    Raising young children with autism spectrum disorders in Hong Kong: the impact of cultural values and stigma on Chinese parents' coping strategies

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    Autism Spectrum Disorder (ASD) is a life-long disability. The long term care of children with ASD has effects on families that teachers and support service providers strive to quantify. Observing 'filial piety' towards one's parents is a traditional Chinese virtue and moral standard. Yet despite the acknowledged importance of the family, relatively little is known about the functioning of Chinese families with children with ASD in Hong Kong (HK). Data was gathered from 100 parents of children with ASD to understand how traditional Chinese beliefs, community values, and the day to day experience of raising a child with ASD in HK, influences the coping strategies that parents employ. It is hoped that the results of this study will raise awareness for the need of further public awareness, educational and support services for families who are currently trying to adjust their parenting skills to cater for a family member with ASD

    Silsesquioxane polymer as a potential scaffold for laryngeal reconstruction

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    Cancer, disease and trauma to the larynx and their treatment can lead to permanent loss of structures critical to voice, breathing and swallowing. Engineered partial or total laryngeal replacements would need to match the ambitious specifications of replicating functionality, outer biocompatibility, and permissiveness for an inner mucosal lining. Here we present porous polyhedral oligomeric silsesquioxane-poly(carbonate urea) urethane (POSS-PCUU) as a potential scaffold for engineering laryngeal tissue. Specifically, we employ a precipitation and porogen leaching technique for manufacturing the polymer. The polymer is chemically consistent across all sample types and produces a foam-like scaffold with two distinct topographies and an internal structure composed of nano- and micro-pores. Whilst the highly porous internal structure of the scaffold contributes to the complex tensile behaviour of the polymer, the surface of the scaffold remains largely non-porous. The low number of pores minimise access for cells, although primary fibroblasts and epithelial cells do attach and proliferate on the polymer surface. Our data show that with a change in manufacturing protocol to produce porous polymer surfaces, POSS-PCUU may be a potential candidate for overcoming some of the limitations associated with laryngeal reconstruction and regeneration
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