Beyond user experience: What constitutes algorithmic experiences?

© 2019 Elsevier Ltd Algorithms are progressively transforming human experience, especially, the interaction with businesses, governments, education, and entertainment. As a result, people are growingly seeing the outside world, in a sense, through the lens of algorithms. Despite the importance of algorithmic experience (AX), few studies had been devoted to investigating the nature and processes through which users perceive and actualize the potential for algorithm affordance. This study proposes the Algorithm Acceptance Model to conceptualize the notion of AX as part of the analytic framework for human-algorithm interaction. It then tests how AX shapes the satisfaction with and acceptance of algorithm services. The results show that AX is inherently related to human understanding of fairness, transparency, and other conventional components of user-experience, indicating the heuristic roles of transparency and fairness regarding their underlying relations of user experience and trust. AX can influence the user perception of algorithmic systems in the context of algorithm ecology, offering useful insights into the design of human-centered algorithm systems. The findings provide initial and robust support for the proposed Algorithm Acceptance Model

Cognitive Modeling of Video Game Player User Experience

This paper argues for the use of cognitive modeling to gain a detailed and dynamic look into user experience during game play. Applying cognitive models to game play data can help researchers understand a player's attentional focus, memory status, learning state, and decision strategies (among other things) as these cognitive processes occurred throughout game play. This is a stark contrast to the common approach of trying to assess the long-term impact of games on cognitive functioning after game play has ended. We describe what cognitive models are, what they can be used for and how game researchers could benefit by adopting these methods. We also provide details of a single model - based on decision field theory - that has been successfUlly applied to data sets from memory, perception, and decision making experiments, and has recently found application in real world scenarios. We examine possibilities for applying this model to game-play data

Intracellular targeting and functional analysis of single-chain Fv fragments in mammalian cells

In the past decade, intracellular antibodies have proven to be a useful tool in obtaining the phenotypic knock-out of selected gene function in different animal and plant systems. This strategy is based on the ectopic expression of recombinant forms of antibodies targeted towards different intracellular compartments, exploiting specific targeting signals to confer the new intracellular location. The functional basis of this technology is closely linked to the ability of intracellular antibodies to interact with their target antigens in vivo. This interaction allows either a direct neutralising effect or the dislodgement of the target protein from its normal intracellular location and, by this mechanism, the inactivation of its function. By using this approach, the function of several antigens has been inhibited in the cytoplasm, the nucleus, and the secretory compartments. In this article, we shall describe all the steps required for expressing single-chain Fv fragments in different subcellular compartments of mammalian cells and their subsequent use in knock-out experiments, starting from a cloned single-chain Fv fragment. This will include the analysis of the solubility properties of the new scFv fragment in transfected mammalian cells, the intracellular distribution of the antigen-antibody complex, and the resulting phenotype

Prediction of weld line location for injection molded thermoplastic components

Weld lines in polymeric injection molded parts occur wherever two or more melt fronts meet. They cause reduced mechanical properties and visual defects due to the poor intermolecular entanglement, molecular orientation induced by the fountain flow and the stress concentration effect of surface V-notch. A challenge related to these defects is that they are hard to detect and monitor because they’re usually not visible to the naked eye. Through this paper a numerical model for mold filling simulations has been developed aiming to predict the location of this defect and the initial meeting angle between the colliding flow fronts. A hybrid interface tracking technique was implemented in conjunction with a fix topology pseudo-quadratic mesh. Navier-Stokes equations were reduced to Hele-Shaw equations for thin plates. For validating purposes polypropylene plates injection moldings with weld lines were produced using a two-gated mold in a laboratory scale injector machine. Location of the defect was measure using an optical polariscope and then contrasted with simulation results. In order to establish the differences between 3D and Hele-Shaw models, predictions of weld line location were compared with the results provided by commercial injection molding simulation package Moldex3D.Publicado en: Mecánica Computacional vol. XXXV, no. 6Facultad de Ingenierí

Prediction of weld line location for injection molded thermoplastic components

Weld lines in polymeric injection molded parts occur wherever two or more melt fronts meet. They cause reduced mechanical properties and visual defects due to the poor intermolecular entanglement, molecular orientation induced by the fountain flow and the stress concentration effect of surface V-notch. A challenge related to these defects is that they are hard to detect and monitor because they’re usually not visible to the naked eye. Through this paper a numerical model for mold filling simulations has been developed aiming to predict the location of this defect and the initial meeting angle between the colliding flow fronts. A hybrid interface tracking technique was implemented in conjunction with a fix topology pseudo-quadratic mesh. Navier-Stokes equations were reduced to Hele-Shaw equations for thin plates. For validating purposes polypropylene plates injection moldings with weld lines were produced using a two-gated mold in a laboratory scale injector machine. Location of the defect was measure using an optical polariscope and then contrasted with simulation results. In order to establish the differences between 3D and Hele-Shaw models, predictions of weld line location were compared with the results provided by commercial injection molding simulation package Moldex3D.Publicado en: Mecánica Computacional vol. XXXV, no. 6Facultad de Ingenierí

Folate-Functionalization Enhances Cytotoxicity of Multivalent DNA Nanocages on Triple-Negative Breast Cancer Cells

DNA is an excellent programmable polymer for the generation of self-assembled multivalent nanostructures useful for biomedical applications. Herein, we developed (i) folate-functionalized nanocages (Fol-NC), very efficiently internalized by tumor cells overexpressing the alpha isoform of the folate receptor; (ii) AS1411-linked nanocages (Apt-NC), internalized through nucleolin, a protein overexpressed in the cell surface of many types of cancers; and (iii) nanostructures that harbor both folate and AS1411 aptamer functionalization (Fol-Apt-NC). We analyzed the specific miRNA silencing activity of all types of nanostructures harboring miRNA sequestering sequences complementary to miR-21 and the cytotoxic effect when loaded with doxorubicin in a drug-resistant triple-negative breast cancer cell line. We demonstrate that the presence of folate as a targeting ligand increases the efficiency in miR-21 silencing compared to nanocages functionalized with AS1411. Double-functionalized nanocages (Fol-Apt-NC), loaded with doxorubicin, resulted in an increase of over 51% of the cytotoxic effect on MDA-MB-231 cells compared to free doxorubicin, demonstrating, besides selectivity, the ability of nanocages to overcome Dox chemoresistance. The higher efficiency of the folate-functionalized nanocages is due to the way of entrance, which induces more than four times higher intracellular stability and indicates that the folate-mediated route of cell entry is more efficient than the nucleolin-mediated one when both folate and AS1411 modifications are present

Orbit stability of the ALS storage ring

The Advanced Light Source (ALS) storage ring, a synchrotron light source of the third generation, is specified to maintain its electron orbit stable within one tenth of the rms beam size. In the absence of a dedicated orbit feed-back system, several orbit-distorting effects were investigated, aided by a new interactive simulation tool, the code TRACY V. The effort has led to a better understanding of the behavior of a variety of accelerator subsystems and in consequence produced a substantial improvement in day-to-day orbit stability

Intestinal Taxa Abundance and Diversity in Inflammatory Bowel Disease Patients: An Analysis including Covariates and Confounders

Intestinal dysbiosis has been widely documented in inflammatory bowel diseases (IBDs) and is thought to influence the onset and perpetuation of gut inflammation. However, it remains unclear whether such bacterial changes rely in part on the modification of an IBD-associated lifestyle (e.g., smoking and physical activity) and diet (e.g., rich in dairy products, cereals, meat and vegetables). In this study, we investigated the impact of these habits, which we defined as confounders and covariates, on the modulation of intestinal taxa abundance and diversity in IBD patients. 16S rRNA gene sequence analysis was performed using genomic DNA extracted from the faecal samples of 52 patients with Crohn's disease (CD) and 58 with ulcerative colitis (UC), which are the two main types of IBD, as well as 42 healthy controls (HC). A reduced microbial diversity was documented in the IBD patients compared with the HC. Moreover, we identified specific confounders and covariates that influenced the association between some bacterial taxa and disease extent (in UC patients) or behaviour (in CD patients) compared with the HC. In particular, a PERMANOVA stepwise regression identified the variables "age", "eat yogurt at least four days per week" and "eat dairy products at least 4 days per week" as covariates when comparing the HC and patients affected by ulcerative proctitis (E1), left-sided UC (distal UC) (E2) and extensive UC (pancolitis) (E3). Instead, the variables "age", "gender", "eat meat at least four days per week" and "eat bread at least 4 days per week" were considered as covariates when comparing the HC with the CD patients affected by non-stricturing, non-penetrating (B1), stricturing (B2) and penetrating (B3) diseases. Considering such variables, our analysis indicated that the UC extent differentially modulated the abundance of the Bifidobacteriaceae, Rikenellaceae, Christensenellaceae, Marinifilaceae, Desulfovibrionaceae, Lactobacillaceae, Streptococcaceae and Peptostreptococcaceae families, while the CD behaviour influenced the abundance of Christensenellaceae, Marinifilaceae, Rikenellaceae, Ruminococcaceae, Barnesiellaceae and Coriobacteriaceae families. In conclusion, our study indicated that some covariates and confounders related to an IBD-associated lifestyle and dietary habits influenced the intestinal taxa diversity and relative abundance in the CD and UC patients compared with the HC. Indeed, such variables should be identified and excluded from the analysis to characterize the bacterial families whose abundance is directly modulated by IBD status, as well as disease extent or behaviour

Designing multiplayer games to facilitate emergent social behaviours online

This paper discusses an exploratory case study of the design of games that facilitate spontaneous social interaction and group behaviours among distributed individuals, based largely on symbolic presence 'state' changes. We present the principles guiding the design of our game environment: presence as a symbolic phenomenon, the importance of good visualization and the potential for spontaneous self-organization among groups of people. Our game environment, comprising a family of multiplayer 'bumper-car' style games, is described, followed by a discussion of lessons learned from observing users of the environment. Finally, we reconsider and extend our design principles in light of our observations

Design of a novel LOX-1 receptor antagonist mimicking the natural substrate

The lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1), the major receptor for oxidized low-density lipoprotein (ox-LDL) in endothelial cells, is overexpressed in atherosclerotic lesions. LOX-1 specific inhibitors, urgently necessary to reduce the rate of atherosclerotic and inflammation processes, are not yet available. We have designed and synthesized a new modified oxidized phospholipid, named PLAzPC, which plays to small scale the ligand-receptor recognition scheme. Molecular docking simulations confirm that PLAzPC disables the hydrophobic component of the ox-LDL recognition domain and allows the interaction of the l-lysine backbone charged groups with the solvent and with the charged/polar residues located around the edges of the LOX-1 hydrophobic tunnel. Binding assays, in a cell model system expressing human LOX-1 receptors, confirm that PLAzPC markedly inhibits ox-LDL binding to LOX-1 with higher efficacy compared to previously identified inhibitors