195 research outputs found

    A Story About Digitalization and Those Left Out : A quantitative study exploring the effect of digitalization on web accessibility.

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    This thesis examines the influence of digitalization on web accessibility for people with disabilities (PwD). The central research question addressed is: "How does digitalization affect web accessibility for people with disabilities?" The hypothesis proposed in this study is that web accessibility decreases as digitalization advances, irrespective of legislation and awareness regarding the accessibility gap. The hypothesis is grounded in the observation that visual aspects are prioritized during web development, potentially overlooking the importance of web accessibility. This is an important topic of research since nearly 20% of the world's population (World Health Organization 2023), have a disability and almost everyone will experience disability at some point in their life (World Health Organization n.d.). Utilizing quantitative methods to conduct an empirical test this research evaluated the web accessibility of 49 Canadian Universities over a 15-year time period, from 2008 to 2022. Data collection utilized online sources such as the Wayback Machine. The research findings reveal that during periods of web advancements, there is an initial increase in web accessibility issues, validating the negative impact of digitalization on web accessibility. However, over time, there is a noticeable reduction in these issues, indicating an overall improvement in web accessibility. One significant factor negatively impacting web accessibility identified in this study is, the visual advancements brought about by digitalization. The effectiveness of legislation in enhancing web accessibility was investigated, focusing on compliance deadlines. The study demonstrates that compliance deadlines do not lead to increased accessibility on the web, meaning legislation fails to effectively improve web accessibility. Overall, this research highlights the immediate inaccessibility of the web resulting from digitalization. These findings emphasize the ongoing need to prioritize web accessibility amidst digital advancements. From these findings, stakeholders can work towards a more inclusive and accessible web environment for PwD.nhhma

    Field quantization in inhomogeneous anisotropic dielectrics with spatio-temporal dispersion

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    A quantum damped-polariton model is constructed for an inhomogeneous anisotropic linear dielectric with arbitrary dispersion in space and time. The model Hamiltonian is completely diagonalized by determining the creation and annihilation operators for the fundamental polariton modes as specific linear combinations of the basic dynamical variables. Explicit expressions are derived for the time-dependent operators describing the electromagnetic field, the dielectric polarization and the noise term in the latter. It is shown how to identify bath variables that generate the dissipative dynamics of the medium.Comment: 24 page

    Correlation structure in nondipole photoionization

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    The nondipole parameters that characterize the angular disribution of the photoelectrons from the 3d subshell of Cs are found to be altered qualitatively by the inclusion of correlation in the form of interchannel coupling between the 3d3/23d_{3/2} and 3d5/23d_{5/2} photoionization channels. A prominent characteristic maximum is predicted only in the parameters for 3d5/23d_{5/2} photoionization, while the effect for 3d3/23d_{3/2} is rather weak. The results are obtained within the framework of the Generalized Random Phase Approximation with Exchange (GRPAE), which in addition to the RPAE effects takes into account the rearrangement of all atomic electrons due to the creation of a 3d vacancy

    Nano-Imprinted Thin Films of Reactive, Azlactone-Containing Polymers: Combining Methods for the Topographic Patterning of Cell Substrates with Opportunities for Facile Post-Fabrication Chemical Functionalization

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    Laser scanning confocal microscopy (LSCM) and atomic force microscopy (AFM) were used to characterize changes in nanoscale structure that occur when ultrathin polyelectrolyte multilayers (PEMs) are incubated in aqueous media. The PEMs investigated here were fabricated by the deposition of alternating layers of plasmid DNA and a hydrolytically degradable polyamine onto a precursor film composed of alternating layers of linear poly(ethylene imine) (LPEI) and sodium poly(styrene sulfonate) (SPS). Past studies of these materials in the context of gene delivery revealed transformations from a morphology that is smooth and uniform to one characterized by the formation of nanometer-scale particulate structures. We demonstrate that in-plane registration of LSCM and AFM images acquired from the same locations of films fabricated using fluorescently labeled polyelectrolytes allows the spatial distribution of individual polyelectrolyte species to be determined relative to the locations of topographic features that form during this transformation. Our results suggest that this physical transformation leads to a morphology consisting of a relatively less disturbed portion of film composed of polyamine and DNA juxtaposed over an array of particulate structures composed predominantly of LPEI and SPS. Characterization by scanning electron microscopy and energy-dispersive X-ray microanalysis provides additional support for this interpretation. The combination of these different microscopy techniques provides insight into the structures and dynamics of these multicomponent thin films that cannot be achieved using any one method alone, and could prove useful for the further development of these assemblies as platforms for the surface-mediated delivery of DNA

    Electric-octupole and pure-electric-quadrupole effects in soft-x-ray photoemission

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    Second-order [O(k^2), k=omega/c] nondipole effects in soft-x-ray photoemission are demonstrated via an experimental and theoretical study of angular distributions of neon valence photoelectrons in the 100--1200 eV photon-energy range. A newly derived theoretical expression for nondipolar angular distributions characterizes the second-order effects using four new parameters with primary contributions from pure-quadrupole and octupole-dipole interference terms. Independent-particle calculations of these parameters account for a significant portion of the existing discrepancy between experiment and theory for Ne 2p first-order nondipole parameters.Comment: 4 pages, 3 figure

    On the photoionization of the outer electrons in noble gas endohedral atoms

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    We demonstrate the prominent modification of the outer shell photoionization cross-section in noble gas (NG) endohedral atoms NG@F under the action of the fullerene F electron shell. This shell leads to two important effects, namely to strong enhancement of the cross-section due to fullerenes shell polarization under the action of the incoming electromagnetic wave and to prominent oscillation of this cross-section due to the reflection of the photoelectron from NG by the F shell. All but He noble gas atoms are considered. The polarization of the fullerene shell is expressed via the total photoabsorption cross-section of F. The reflection of the photoelectron is taken into account in the frame of the so-called bubble potential that is a spherical zero --thickness potential. It is assumed in the derivations that NG is centrally located in the fullerene. It is assumed also, in accord with the existing experimental data, that the fullerenes radius R is much bigger than the atomic radius and the thickness of the fullerenes shell . These assumptions permit, as it was demonstrated recently, to present the NG@F photoionization cross-section as a product of the NG cross-section and two well defined calculated factors.Comment: 19 pages, 9 figure

    Selective PDE4 subtype inhibition provides new opportunities to intervene in neuroinflammatory versus myelin damaging hallmarks of multiple sclerosis

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    Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system (CNS) characterized by focal inflammatory lesions and prominent demyelination. Even though the currently available therapies are effective in treating the initial stages of disease, they are unable to halt or reverse disease progression into the chronic progressive stage. Thus far, no repair-inducing treatments are available for progressive MS patients. Hence, there is an urgent need for the development of new therapeutic strategies either targeting the destructive immunological demyelination or boosting endogenous repair mechanisms. Using in vitro, ex vivo, and in vivo models, we demonstrate that selective inhibition of phosphodiesterase 4 (PDE4), a family of enzymes that hydrolyzes and inactivates cyclic adenosine monophosphate (cAMP), reduces inflammation and promotes myelin repair. More specifically, we segregated the myelination-promoting and anti-inflammatory effects into a PDE4D- and PDE4B-dependent process respectively. We show that inhibition of PDE4D boosts oligodendrocyte progenitor cells (OPC) differentiation and enhances (re)myelination of both murine OPCs and human iPSC-derived OPCs. In addition, PDE4D inhibition promotes in vivo remyelination in the cuprizone model, which is accompanied by improved spatial memory and reduced visual evoked potential latency times. We further identified that PDE4B-specific inhibition exerts anti-inflammatory effects since it lowers in vitro monocytic nitric oxide (NO) production and improves in vivo neurological scores during the early phase of experimental autoimmune encephalomyelitis (EAE). In contrast to the pan PDE4 inhibitor roflumilast, the therapeutic dose of both the PDE4B-specific inhibitor A33 and the PDE4D-specific inhibitor Gebr32a did not trigger emesis-like side effects in rodents. Finally, we report distinct PDE4D isoform expression patterns in human area postrema neurons and human oligodendroglia lineage cells. Using the CRISPR-Cas9 system, we confirmed that pde4d1/2 and pde4d6 are the key targets to induce OPC differentiation. Collectively, these data demonstrate that gene specific PDE4 inhibitors have potential as novel therapeutic agents for targeting the distinct disease processes of MS

    The emergence of altruism as a social norm

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    Expectations, exerting influence through social norms, are a very strong candidate to explain how complex societies function. In the Dictator game (DG), people expect generous behavior from others even when they cannot enforce any sharing of the pie. Here we assume that people donate following their expectations, and that they update their expectation after playing a DG by reinforcement learning to construct a model that explains the main experimental results in the DG. Full agreement with the experimental results is reached when some degree of mismatch between expectations and donations is added into the model. These results are robust against the presence of envious agents, but affected if we introduce selfish agents that do not update their expectations. Our results point to social norms being on the basis of the generous behavior observed in the DG and also to the wide applicability of reinforcement learning to explain many strategic interactions
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