1,789 research outputs found

    Inclusive or exclusive? Investigating how retail technology can reduce old consumers’ barriers to shopping

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    This paper investigates older consumers in-store shopping experiences and the barriers that they face. The aim is to understand how new retail technologies (e.g., interactive in-store displays, self-service tills, robots etc.) can help seniors access satisfying, autonomous retail experiences, helping them to achieve a sense of inclusion in physical retail settings. Drawing upon the social inclusion/exclusion theory and information overload theory, the research employs a qualitative approach based on an inductive design, including face-to-face semi structured interviews with 36 consumers aged 75+. The findings highlight (i) old consumers have scarce interactions with in-store technologies (adding knowledge to motivations literature), (ii) the need to develop new technologies to support these consumers, and (iii) the extent to which these technologies are excluding rather than including old consumers (adding knowledge to the drivers of the field of exclusion). Results provide guidelines for retailers to enhance the sense of inclusion for old consumers through a better usage of new technologies

    Characterization of preclones by matrix collections

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    Preclones are described as the closed classes of the Galois connection induced by a preservation relation between operations and matrix collections. The Galois closed classes of matrix collections are also described by explicit closure conditions.Comment: 11 page

    Plaque quantitiation through protein measurement

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    PKThis study was undertaken to establish whether the quantitation of dental plaque protein by a dye-binding method (Coomassie G-250) may be used as an index of the amount of dental plaque sampled. Ten sites were sampled in 34 children on 5 occasions at 4 month intervals. The mean protein concentration in 1391 plaque samples was 6.9 +/- 4.1 micrograms (micrograms) (mean +/- standard deviation). A three-way analysis of variance showed that the plaque protein concentration was similar at the different sampling sites in the same child (p = 0.14), but statistically significant differences were observed with respect to time of sampling (F = 36.24; p = 0.0001) and individual sampled (F = 5.69; p = 0.0001). These observations indicate that plaque bacterial counts may be expressed as units of protein concentration and this method may be useful to relate the number of viable bacteria to an estimate of the amount of plaque collected. This ratio allows standardisation for any variation in the amount of plaque collected

    Gyrotropic impact upon negatively refracting surfaces

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    Surface wave propagation at the interface between different types of gyrotropic materials and an isotropic negatively refracting medium, in which the relative permittivity and relative permeability are, simultaneously, negative is investigated. A general approach is taken that embraces both gyroelectric and gyromagnetic materials, permitting the possibility of operating in either the low GHz, THz or the optical frequency regimes. The classical transverse Voigt configuration is adopted and a complete analysis of non-reciprocal surface wave dispersion is presented. The impact of the surface polariton modes upon the reflection of both plane waves and beams is discussed in terms of resonances and an example of the influence upon the Goos–HĂ€nchen shift is given

    Open-closed homotopy algebra in mathematical physics

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    In this paper we discuss various aspects of open-closed homotopy algebras (OCHAs) presented in our previous paper, inspired by Zwiebach's open-closed string field theory, but that first paper concentrated on the mathematical aspects. Here we show how an OCHA is obtained by extracting the tree part of Zwiebach's quantum open-closed string field theory. We clarify the explicit relation of an OCHA with Kontsevich's deformation quantization and with the B-models of homological mirror symmetry. An explicit form of the minimal model for an OCHA is given as well as its relation to the perturbative expansion of open-closed string field theory. We show that our open-closed homotopy algebra gives us a general scheme for deformation of open string structures (A∞A_\infty-algebras) by closed strings (L∞L_\infty-algebras).Comment: 38 pages, 4 figures; v2: published versio

    RNA-Sequencing Reveals Direct Targets of Tumor Suppressor miR-203 in Human Mammary Epithelial Cells

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    Background: Breast cancer is the leading cause of cancer-related mortality in women worldwide. Since a significant portion of cases present with or progress to metastatic disease, furthering our understanding of metastasis is critical to develop better treatments. Epithelial cells maintain contact with the extracellular matrix (ECM) predominantly via integrin engagement, a process required for tissue integrity and barrier function. In non-transformed cells, loss of ECM adhesion promotes a specialized form of programmed cell death, anoikis. In order for efficient metastasis to occur, breast tumor cells must evade anoikis. miR-203, known to be down-regulated in several cancers, was found by our lab to be induced ten-fold 24 hours following detachment in breast epithelial cells, but not invasive triple negative breast cancer (TNBC) cells, suggesting that miR-203 may participate in promoting anoikis. Interestingly, more invasive breast cancer cell lines have been shown to express miR-203 at significantly lower levels than those of less invasive lines. Objectives: Since restoration of miR-203 expression ectopically is not feasible in a clinical setting, we sought to identify and characterize miR-203 target genes in order to provide a pharmaceutical platform for restoration of anoikis sensitivity in metastatic breast cancer. Methods: We performed traditional RNA-sequencing (RNA-Seq) coupled with immunoprecipitation of the RNA-induced silencing complex (RISC; Ago2 RIP-Seq) in MCF-10A, an immortalized, but non-transformed breast epithelial cell line, overexpressing precursor miR-203 or an empty vector control. MDA-MB-231, triple negative ductal carcinoma cells, were used as our invasive comparison cell line. Results: Here we show that miR-203 induction in detached MCF-10A cells is due to loss of integrin signaling. Our coupled RNA-Seq and Ago2 RIP-Seq approach revealed 72 potential candidates, 42 of which were predicted miR-203 targets based on the TargetScan algorithm. We subjected the candidates to stringent characterization and found 9 bona-fide miR-203 targets that promote cell death when inhibited. Among these, WDR69, PRKAB1, PRPS2, and HBEGF were significantly elevated in TNBC tumor samples, as determined by RNA-Seq analysis in The Cancer Genome Atlas (TCGA). Conclusion: Understanding the mechanisms by which cells evade anoikis during tumor dissemination is crucial to developing more effective therapies in breast cancer. miR-203, which is expressed at very low levels in more invasive breast cancers, is a positive regulator of anoikis that is upregulated in response to loss of contact with the ECM. Our combined RNA-sequencing screen revealed 42 direct miR-203 targets. Inhibition of 9 bona-fide targets promoted cell death, suggesting that they are negative regulators of anoikis. WDR69, PRKAB1, PRPS2, and HBEGF were all significantly elevated in TNBC tumor samples relative to less invasive samples, likely a consequence of low miR-203 expression. The identified genes represent potential pharmaceutical targets for novel breast cancer therapies

    Biostratigraphy of Middle and Late Pennsylvanian (Desmoinesian-Virgilian) ammonoids

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    New stratigraphic ranges for genera of Desmoinesian-Virgilian ammonoids are presented, based on analysis of 40,000 specimens collected from over 70 ammonoid-bearing horizons that represent at least 40 successive stratigraphic levels in the North American midcontinent. These range revisions indicate that current generic-level ammonoid zonations are inadequate, especially for correlation of Pennsylvanian series and stage boundaries. Six high-confidence, largely generic-level first-occurrence zones are proposed for the Desmoinesian through Virgilian stages: Wellerites Zone, Eothalassoceras Zone, Pennoceras Zone, Preshumardites Zone, Pseudaktubites Zone, and Shumardites Zone. Fifteen zones of lesser confidence for correlation are also suggested. The Shumarditidae Plummer & Scott, 1937, is emended to include Preshumardites Plummer & Scott, 1937, Pseudaktubites gen. nov. (type species, Preshumardites stainbrooki Plummer & Scott, 1937), and Shumardites Smith, 1903. Early Permian (Sakmarian) species previously assigned to Preshumardites are reassigned to Andrianovia gen. nov. (type species ?Preshumardites sakmarae Ruzhencev, 1938). Aktubites Ruzhencev, 1955, Eoshumardites Popov, 1960, and Parashumardites Ruzhencev, 1939, previously included in the Shumarditidae, are assigned to the new family Parashumarditidae. Eovidrioceras inexpectans gen. nov., sp. nov. is included and is interpreted as the ancestor of the cyclobacean family Vidrioceratidae Plummer & Scott, 1937. The base of the revised Wellerites Zone, defined by the first occurrence of the nominate genus, approximates but does not coincide with the Atokan-Desmoinesian boundary. Recorrelation of the stratigraphic level of the Collinsville, Oklahoma, ammonoid locality from the "Seminole Formation" (basal Missourian) to the Holdenville Formation (upper Desmoinesian), based on lithostratigraphic evidence, effectively places the first occurrence of Eothalassoceras in the upper Desmoinesian. Because Wellerites apparently became extinct before the end of the Desmoinesian, the revised Eothalassoceras Zone is used to represent the upper Desmoinesian. The Middle-Upper Pennsylvanian boundary (Desmoinesian-Missourian boundary) can be recognized by the appearance of Pennoceras, which defines the base of the new Pennoceras Zone. The Pennoceras Zone is an excellent indicator of lower Missourian strata in the northern midcontinent, north-central Texas, the Marathon Uplift, and the Appalachian Basin. The new Preshumardites Zone occupies most of the upper part of the Missourian Stage. The appearance of the ancestral shumarditid Pseudaktubites, which defines the base of the new Pseudaktubites Zone, occurs one cycle below the Missourian-Virgilian boundary, which is currently recognized at the top of the South Bend Limestone Member in eastern Kansas. No recognizable biostratigraphic event coincides with the South Bend Member, thereby resulting in an uncorrelatable chronostratigraphic boundary. The largest changeover in ammonoid faunas takes place at the base of strata containing the upper part of the Pseudaktubites Zone (Pseudaktubites stainbrooki Subzone). The base of the Pseudaktubites stainbrooki Subzone is stratigraphically near the original Missourian-Virgilian boundary. It is recommended that the stratigraphic level containing the base of the Pseudaktubites stainbrooki Subzone be adopted as the official base of the Virgilian Stage. Recognition of the upper subzone of the Pseudaktubites Zone (Pseudaktubites stainbrooki Subzone) within the Colony Creek Shale Member in north-central Texas places the base of the Virgilian within the upper part of the Canyon Group and substantially below the current position at the Canyon-Cisco group boundary. Shumardites, a taxon previously used to mark the base of the Virgilian Stage, appears in early middle Virgilian strata; consequently, the revised Shumardites Zone represents the middle-upper Virgilian interval

    Biostratigraphy of Middle and Late Pennsylvanian (Desmoinesian-Virgilian) ammonoids

    Get PDF
    New stratigraphic ranges for genera of Desmoinesian-Virgilian ammonoids are presented, based on analysis of 40,000 specimens collected from over 70 ammonoid-bearing horizons that represent at least 40 successive stratigraphic levels in the North American midcontinent. These range revisions indicate that current generic-level ammonoid zonations are inadequate, especially for correlation of Pennsylvanian series and stage boundaries. Six high-confidence, largely generic-level first-occurrence zones are proposed for the Desmoinesian through Virgilian stages: Wellerites Zone, Eothalassoceras Zone, Pennoceras Zone, Preshumardites Zone, Pseudaktubites Zone, and Shumardites Zone. Fifteen zones of lesser confidence for correlation are also suggested. The Shumarditidae Plummer & Scott, 1937, is emended to include Preshumardites Plummer & Scott, 1937, Pseudaktubites gen. nov. (type species, Preshumardites stainbrooki Plummer & Scott, 1937), and Shumardites Smith, 1903. Early Permian (Sakmarian) species previously assigned to Preshumardites are reassigned to Andrianovia gen. nov. (type species ?Preshumardites sakmarae Ruzhencev, 1938). Aktubites Ruzhencev, 1955, Eoshumardites Popov, 1960, and Parashumardites Ruzhencev, 1939, previously included in the Shumarditidae, are assigned to the new family Parashumarditidae. Eovidrioceras inexpectans gen. nov., sp. nov. is included and is interpreted as the ancestor of the cyclobacean family Vidrioceratidae Plummer & Scott, 1937. The base of the revised Wellerites Zone, defined by the first occurrence of the nominate genus, approximates but does not coincide with the Atokan-Desmoinesian boundary. Recorrelation of the stratigraphic level of the Collinsville, Oklahoma, ammonoid locality from the "Seminole Formation" (basal Missourian) to the Holdenville Formation (upper Desmoinesian), based on lithostratigraphic evidence, effectively places the first occurrence of Eothalassoceras in the upper Desmoinesian. Because Wellerites apparently became extinct before the end of the Desmoinesian, the revised Eothalassoceras Zone is used to represent the upper Desmoinesian. The Middle-Upper Pennsylvanian boundary (Desmoinesian-Missourian boundary) can be recognized by the appearance of Pennoceras, which defines the base of the new Pennoceras Zone. The Pennoceras Zone is an excellent indicator of lower Missourian strata in the northern midcontinent, north-central Texas, the Marathon Uplift, and the Appalachian Basin. The new Preshumardites Zone occupies most of the upper part of the Missourian Stage. The appearance of the ancestral shumarditid Pseudaktubites, which defines the base of the new Pseudaktubites Zone, occurs one cycle below the Missourian-Virgilian boundary, which is currently recognized at the top of the South Bend Limestone Member in eastern Kansas. No recognizable biostratigraphic event coincides with the South Bend Member, thereby resulting in an uncorrelatable chronostratigraphic boundary. The largest changeover in ammonoid faunas takes place at the base of strata containing the upper part of the Pseudaktubites Zone (Pseudaktubites stainbrooki Subzone). The base of the Pseudaktubites stainbrooki Subzone is stratigraphically near the original Missourian-Virgilian boundary. It is recommended that the stratigraphic level containing the base of the Pseudaktubites stainbrooki Subzone be adopted as the official base of the Virgilian Stage. Recognition of the upper subzone of the Pseudaktubites Zone (Pseudaktubites stainbrooki Subzone) within the Colony Creek Shale Member in north-central Texas places the base of the Virgilian within the upper part of the Canyon Group and substantially below the current position at the Canyon-Cisco group boundary. Shumardites, a taxon previously used to mark the base of the Virgilian Stage, appears in early middle Virgilian strata; consequently, the revised Shumardites Zone represents the middle-upper Virgilian interval

    Nonlinear interfaces: intrinsically nonparaxial regimes and effects

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    The behaviour of optical solitons at planar nonlinear boundaries is a problem rich in intrinsically nonparaxial regimes that cannot be fully addressed by theories based on the nonlinear Schrödinger equation. For instance, large propagation angles are typically involved in external refraction at interfaces. Using a recently proposed generalized Snell's law for Helmholtz solitons, we analyse two such effects: nonlinear external refraction and total internal reflection at interfaces where internal and external refraction, respectively, would be found in the absence of nonlinearity. The solutions obtained from the full numerical integration of the nonlinear Helmholtz equation show excellent agreement with the theoretical predictions
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