749 research outputs found
Motive-demand dynamics creating a social context for studentsâ learning experiences in a making and design environment
Making and design environments, often referred to as makerspaces, have aroused recent educational interest. These environments typically consist of spaces that support interest-driven engagement in hands-on creative activities with a range of digital artefacts. Although a variety of benefits from participating in making and design activities have been proposed, we currently have limited understanding of studentsâ learning experiences in makerspaces situated in schools. Following Hedegaardsâ conceptualisations, we investigate motive-demand dynamics in studentsâ social activity in a school-based digital making and design environment, âThe FUSE Studioâ. We highlight our findings via vignettes selected from 65 h of video recordings of 94 students (aged between 9 and 12 years old) carrying out activities; the recordings were collected intermittently from an elective course over one semester. Our study illustrates how the studentsâ learning experiences were shaped through tension-laden interplay between the motives and demands of their activity situated across personal, relational and institutional contexts. The findings make visible how established ways of working and being at school interacted and came into tension with the studentsâ motive orientations, thereby limiting and at times transforming the social context of their learning. Our work also demonstrates how the analysis of motive-demand dynamics offers one useful conceptual tool to unpack studentsâ learning experiences in novel learning environments.Peer reviewe
Spatially resolved spectroscopic differentiation of hydrophilic and hydrophobic domains on individual insulin amyloid fibrils
The formation of insoluble β-sheet-rich protein structures known as amyloid fibrils is associated with numerous neurodegenerative diseases, such as Alzheimerâs and Parkinsonâs disease. A detailed understanding of the molecular structure of the fibril surface is of interest as the first contact with the physiological environment in vivo and plays a decisive role in biological activity and associated toxicity. Recent studies reveal that the inherent sensitivity and specificity of tip-enhanced Raman scattering (TERS) renders this technique a compelling method for fibril surface analysis at the single-particle level. Here, the reproducibility of TERS is demonstrated, indicating its relevance for detecting molecular variations. Consequently, individual fibrils are systematically investigated at nanometer spatial resolution. Spectral parameters were obtained by band-fitting, particularly focusing on the identification of the secondary structure via the amide III band and the differentiation of hydrophobic and hydrophilic domains on the surface. In addition multivariate data analysis, specifically the N-FINDR procedure, was employed to generate structure-specific maps. The ability of TERS to localize specific structural domains on fibril surfaces shows promise to the development of new fibril dissection strategies and can be generally applied to any (bio)chemical surface when structural variations at the nanometer level are of interest
Unsupervised hyperspectral data mining and bioimaging by information entropy and self-modeling curve resolution
Unsupervised estimation of the dimensionality of hyperspectral
microspectroscopy datasets containing pure and mixed spectral features, and
extraction of their representative endmember spectra, remains a challenge in
biochemical data mining. We report a new versatile algorithm building on
semi-nonnegativity constrained self-modeling curve resolution and information
entropy, to estimate the quantity of separable biochemical species from
hyperspectral microspectroscopy, and extraction of their representative
spectra. The algorithm is benchmarked with established methods from satellite
remote sensing, spectral unmixing, and clustering. To demonstrate the
widespread applicability of the developed algorithm, we collected hyperspectral
datasets using spontaneous Raman, Coherent Anti-stokes Raman Scattering and
Fourier Transform IR, of seven reference compounds, an oil-in-water emulsion,
and tissue-engineered extracellular matrices on poly-L-lactic acid and porcine
jejunum-derived small intestine submucosa scaffolds seeded with bovine
chondrocytes. We show the potential of the developed algorithm by consolidating
hyperspectral molecular information with sample microstructure, pertinent to
fields ranging from gastrophysics to regenerative medicine
Variation in NOD2 Augments Th2- and Th17 Responses to Myelin Basic Protein in Multiple Sclerosis
Variations in the gene for the nucleotide-binding oligomerisation domain (NOD) 2 have been associated with Crohn's disease but not multiple sclerosis (MS). Here we investigate the effect of three polymorphisms in the NOD2 gene (rs5743277, rs2066842 and rs5743291) on cytokine production and CD4+ T cell proliferation elicited by human myelin basic protein (MBP) in blood mononuclear cell (MNC) cultures from 29 patients with MS. No polymorphism was observed at rs5743277. No associations with the rs2066842 polymorphism were found. Concerning rs5743291, none were homozygous for the minor allele. Seven of 29 (24%) patients were heterozygous, and five of these (71%) exhibited increased MBP-induced CD4+ T cell proliferation versus four of 22 (18%), who were homozygous for the major allele (p<0.04). Interleukin (IL)-5 was induced by MBP in MNC from the same five carriers versus two (9%) homozygotes (p<0.004); four carriers (57%) versus three non-carriers (14%) exhibited IL-17 responses to MBP (p<0.04). By contrast, we found no association between the polymorphisms investigated and interferon-gamma-, tumor necrosis factor-alpha-, IL-2, -4- or IL-10 responses to MBP. These results indicate that the rs5743291 polymorphism influences T helper (Th) cell 2- and Th17 cell responses in MNC from MS patients
A self-assembly based supramolecular bioink with hierarchical control As a new bioprinting tool
Tissue engineering aims to capture details of the extracellular matrix (ECM) that stimulate cell growth and tissue regeneration. Molecularly complex materials or advanced additive fabrication techniques are often used to capture aspects of the ECM. Promising biofabrication techniques often lack nano and molecular scale control, as well as materials that can recreate the natural ECM or selectively guide cell behaviour. On the other hand, complex biomaterials based on molecular self-assembly tend to lack reproducibility and order beyond the nanoscale. We propose a new material fabrication platform that integrates the benefits of bioprinting and molecular self-assembly to overcome the current major limitations. Our approach relies on the co-assembly of peptide amphiphiles (PAs) with biomolecules and/or proteins found in the ECM, whilst exploiting the droplet-on-demand (DoD) printing process. Taking advantage of the interfacial fluid forces during printing, it is possible to guide the self-assembly into aligned or disordered nanofibers, hydrogel structures of different geometries and sizes, surface topographies and higher-ordered structures made from multiple hydrogels. The co-assembly process can be performed during printing and in cell-friendly conditions, whilst exhibiting high cell viability (\u3e 88 %). Moreover, multiple cell types can be spatially distributed on the outside or embedded within the tuneable biomimetic scaffolds. The combination of self-assembly with 3D-bioprinting, provides a basis for a new biofabrication platform to create hydrogels of complex geometry, structural hierarchy and tuneable chemical composition.
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COVID-19 did not result in increased hospitalization for stroke and transient ischemic attack:A nationwide study
BACKGROUND: The risk of thrombosis increases in infectious diseases, yet observational studies from single centers have shown a decrease in admission of acute ischemic stroke patients during the COVIDâ19 pandemic. To investigate unselected stroke admission rates we performed a nationwide study in Denmark. METHODS: We extracted information from Danish national health registries. The following mutually exclusive time periods were compared to the year before the lockdown: (1) first national lockdown, (2) gradual reopening, (3) few restrictions, (4) regional lockdown, and (5) second national lockdown. RESULTS: Generally, admission rates were unchanged during the pandemic. In the unadjusted data, we observed a small decrease in the admission rate for all strokes under the first lockdown (incidence rate ratio: 0.93, confidence interval [CI]: 0.87â0.99) and a slight increase during the periods with gradual reopening, few restrictions, and the regional lockdown driven by ischemic strokes. We found no change in the rate of severe strokes, mild strokes, or 30âday mortality. An exception was the higher mortality for all strokes during the first lockdown (risk ratio: crude 1.30 [CI: 1.03â1.59]; adjusted 1.17 [CI: 0.93â1.47]). The quality of care remained unchanged. CONCLUSION: Stroke admission rates remained largely unchanged during the pandemic, while an increased shortâterm mortality rate in patients admitted with stroke observed during the first lockdown was seen, probably reflecting that the more frail patients constituted a higher proportion of admitted patients at the beginning of the pandemic
The Association of State Opioid Misuse Prevention Policies With Patientâ and ProviderâRelated Outcomes: A Scoping Review
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154648/1/milq12436.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/154648/2/milq12436_am.pd
Methods for interpreting lists of affected genes obstained in a DNA microarray experiment
Background - The aim of this paper was to describe and compare the methods used and the results obtained by the participants in a joint EADGENE (European Animal Disease Genomic Network of Excellence) and SABRE (Cutting Edge Genomics for Sustainable Animal Breeding) workshop focusing on post analysis of microarray data. The participating groups were provided with identical lists of microarray probes, including test statistics for three different contrasts, and the normalised log-ratios for each array, to be used as the starting point for interpreting the affected probes. The data originated from a microarray experiment conducted to study the host reactions in broilers occurring shortly after a secondary challenge with either a homologous or heterologous species of Eimeria. Results - Several conceptually different analytical approaches, using both commercial and public available software, were applied by the participating groups. The following tools were used: Ingenuity Pathway Analysis, MAPPFinder, LIMMA, GOstats, GOEAST, GOTM, Globaltest, TopGO, ArrayUnlock, Pathway Studio, GIST and AnnotationDbi. The main focus of the approaches was to utilise the relation between probes/genes and their gene ontology and pathways to interpret the affected probes/genes. The lack of a well-annotated chicken genome did though limit the possibilities to fully explore the tools. The main results from these analyses showed that the biological interpretation is highly dependent on the statistical method used but that some common biological conclusions could be reached. Conclusion - It is highly recommended to test different analytical methods on the same data set and compare the results to obtain a reliable biological interpretation of the affected genes in a DNA microarray experimen
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