3,014 research outputs found

    Technology use in everyday life: Implications for designing for older users

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    This study examines the experience and attitudes of older adults towards technology and how they compare with younger age groups. Two hundred and thirty seven participants completed an extensive questionnaire exploring their daily lifestyle, use of technology, attitudes towards technology, and perceived difficulty of household devices. The main findings from the study were; (1) there was a strong motivation to learn or to continue learning to use computers by the older group; (2) social connectedness influenced how the older group used or would like to use technology and also why some preferred not to use it; and finally (3) there was an age-related increase in perceived difficulty for many household devices, however some devices maintained intergenerational usability. These finding can be used to inform the design of future intergenerational household technologies

    Engineering ambient visual sensors

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    Visual sensors are an indispensable prerequisite for those AmI environments that require a surveillance component. One practical issue concerns maximizing the operational longevity of such sensors as the operational lifetime of an AmI environment itself is dependent on that of its constituent components. In this paper, the intelligent agent paradigm is considered as a basis for managing a camera collective such that the conflicting demands of power usage optimization and system performance are reconciled

    Identification of misconceptions in the teaching of biology

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    peer-reviewedTo date research into how young people acquire accurate higher-order scientific knowledge, and gain an understanding of abstract and challenging concepts in science, has occupied much of the science education literature across countries and across continents. In previous studies, we identified that biology teaching that involves the diagnosis, reduction and elimination of misconceptions can be one effective pedagogic approach, particularly if positioned within a “good enough” model of pedagogic practice1 . In this study, we investigate the use of one diagnostic testing approach to the identification of misconceptions in the teaching of respiration and photosynthesis in a small sample of secondary school students (n=139) and pre-service teachers (n=43) in the Republic of Ireland. Photosynthesis and respiration were chosen as they are prevalent biology topics that students find conceptually challenging. The study used test items to elicit the extent of misconceptions among this cohort – a paper-and-pencil test for students and a survey instrument for pre-service teachers. The findings show unacceptably high level of misconceptions among all pre-service teachers and students and suggest that diagnostic tests of this type can be a useful entry point to a pedagogical cycle for the recognition, reduction and removal of misconceptions. The findings have wider implications than this small scale study and are primarily directed toward new understandings in relation to more effective models of biology teaching and teacher education.PUBLISHEDpeer-reviewe

    Integral constraints on the monodromy group of the hyperkahler resolution of a symmetric product of a K3 surface

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    Let M be a 2n-dimensional Kahler manifold deformation equivalent to the Hilbert scheme of length n subschemes of a K3 surface S. Let Mon be the group of automorphisms of the cohomology ring of M, which are induced by monodromy operators. The second integral cohomology of M is endowed with the Beauville-Bogomolov bilinear form. We prove that the restriction homomorphism from Mon to the isometry group O[H^2(M)] is injective, for infinitely many n, and its kernel has order at most 2, in the remaining cases. For all n, the image of Mon in O[H^2(M)] is the subgroup generated by reflections with respect to +2 and -2 classes. As a consequence, we get counter examples to a version of the weight 2 Torelli question, when n-1 is not a prime power.Comment: Version 3: Latex, 54 pages. Expository change

    The origin of centennial- to millennial-scale chronological gaps in storm emplaced beach ridge plains

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    Recent studies of tropical cyclone surge and wave emplaced beach ridge plains have shown that these sequences often contain centennial to millennial scale gaps in their chronologies. Two explanations for the gaps exist — they are due to erosion, or alternatively a cessation or substantial slowing of depositional processes suggestive of a quieter phase in intense storm activity. Differentiating between the two is important for uncovering reliable long-term storm histories from these sequences. We use landform morphology, sediment texture and luminescence chronology to determine the origin of substantial chronological gaps in a plain containing more than 100 shore-parallel ridges composed of fine-grained sand located in northeast Australia. We identify and describe the characteristics associated with both erosional and non-erosional gaps. The erosional gaps are associated with changes in orientation between ridge sets and often a high ridge with hummocky topography that appears to have been disturbed by aeolian activity. River floods likely caused the partial erosion of ridge sets. Non-erosional gaps do not display these morphological characteristics and are likely associated with quiescence in severe tropical cyclone activity. These geomorphic and chronological signatures can be used to identify different sorts of gaps in other ridge plains and are an important tool in the reconstruction of long-term storm histories from these coastal landforms. The data also suggests that fine-grained ridges can, like their coarse-grained counterparts, be predominantly deposited by storm waves and surge and their texture need not necessarily be indicative of the processes responsible for ridge development

    New skeletal tuberculosis cases in past populations from Western Hungary (Transdanubia)

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    The distribution, antiquity and epidemiology of tuberculosis (TB) have previously been studied in osteoarchaeological material in the eastern part of Hungary, mainly on the Great Plain. The purpose of this study is to map the occurrence of skeletal TB in different centuries in the western part of Hungary, Transdanubia, and to present new cases we have found. Palaeopathological analysis was carried out using macroscopic observation supported by radiographic and molecular methods. A large human osteoarchaeological sample (n = 5684) from Transdanubian archaeological sites ranging from the 2nd to the 18th centuries served as a source of material. Spinal TB was observed in seven individuals (in three specimens with Pott's disease two of which also had cold abscess) and hip TB was assumed in one case. The results of DNA for Mycobacterium tuberculosis were positive in seven of the eight cases identified by paleopathology, and negative in the assumed case of hip TB. However, the molecular results are consistent with highly fragmented DNA, which limited further analysis. Based on the present study and previously published cases, osteotuberculosis was found in Transdanubia mainly during the 9th–13th centuries. However, there are no signs of TB in many other 9th–13th century sites, even in those that lie geographically close to those where osteotuberculous cases were found. This may be due to a true absence of TB caused by the different living conditions, way of life, or origin of these populations. An alternative explanation is that TB was present in some individuals with no typical paleopathology, but that death occurred before skeletal morphological features could develop

    High Sensitivity DNA Detection Using Gold Nanoparticle Functionalised Polyaniline Nanofibres

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    Polyaniline (PANI) nanofibres (PANI-NF) have been modified with chemically grown gold nanoparticles to give a nanocomposite material (PANI-NF–AuNP) and deposited on gold electrodes. Single stranded capture DNA was then bound to the gold nanoparticles and the underlying gold electrode and allowed to hybridise with a complementary target strand that is uniquely associated with the pathogen, Staphylococcus aureus (S. aureus), that causes mastitis. Significantly, cyclic voltammetry demonstrates that deposition of the gold nanoparticles increases the area available for DNA immobilisation by a factor of approximately 4. EPR reveals that the addition of the Au nanoparticles efficiently decreases the interactions between adjacent PANI chains and/or motional broadening. Finally, a second horseradish peroxidase (HRP) labelled DNA strand hybridises with the target allowing the concentration of the target DNA to be detected by monitoring the reduction of a hydroquinone mediator in solution. The sensors have a wide dynamic range, excellent ability to discriminate DNA mismatches and a high sensitivity. Semi-log plots of the pathogen DNA concentration vs. faradaic current were linear from 150 × 10−12 to 1 × 10−6 mol L−1 and pM concentrations could be detected without the need for molecular, e.g., PCR or NASBA, amplification

    The geometry of antisymplectic involutions, I

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    We study fixed loci of antisymplectic involutions on projective hyperkahler manifolds of K3([n])-type. When the involution is induced by an ample class of square 2 in the Beauville-Bogomolov-Fujiki lattice, we show that the number of connected components of the fixed locus is equal to the divisibility of the class, which is either 1 or 2

    Altered expression of caspases-4 and -5 during inflammatory bowel disease and colorectal cancer : diagnostic and therapeutic potential

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    Caspases are a group of proteolytic enzymes involved in the co-ordination of cellular processes, including cellular homeostasis, inflammation and apoptosis. Altered activity of caspases, particularly caspase-1, has been implicated in the development of intestinal diseases, such as inflammatory bowel disease (IBD) and colorectal cancer (CRC). However, the involvement of two related inflammatory caspase members, caspases-4 and -5, during intestinal homeostasis and disease has not yet been established. This study demonstrates that caspases-4 and -5 are involved in IBD-associated intestinal inflammation. Furthermore, we found a clear correlation between stromal caspase-4 and -5 expression levels, inflammation and disease activity in ulcerative colitis patients. Deregulated intestinal inflammation in IBD patients is associated with an increased risk of developing CRC. We found robust expression of caspases-4 and -5 within intestinal epithelial cells, exclusively within neoplastic tissue, of colorectal tumours. An examination of adjacent normal, inflamed and tumour tissue from patients with colitis-associated CRC confirmed that stromal expression of caspases-4 and -5 is increased in inflamed and dysplastic tissue, while epithelial expression is restricted to neoplastic tissue. In addition to identifying caspases-4 and -5 as potential targets for limiting intestinal inflammation, this study has identified epithelial-expressed caspases-4 and -5 as biomarkers with diagnostic and therapeutic potential in CRC
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