538 research outputs found
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Standardized maximim D-optimal designs for enzyme kineticinhibition models
Locally optimal designs for nonlinear models require a single set of nominal values for the unknown parameters.An alternative is the maximin approach that allows the user to specify a range of values for each parameter ofinterest. However, the maximin approach is difficult because we first have to determine the locally optimal designfor each set of nominal values before maximin types of optimal designs can be found via a nested optimizationprocess. We show that particle swarm optimization (PSO) techniques can solve such complex optimizationproblems effectively. We demonstrate numerical results from PSO can help find, for the first time, formulae forstandardized maximin D-optimal designs for nonlinear model with 3 or 4 parameters on the compact andnonnegative design space. Additionally, we show locally and standardized maximin D-optimal designs for inhibitionmodels are not necessarily supported at a minimum number of points. To facilitate use of such designs, wecreate a web-based tool for practitioners to find tailor-made locally and standardized maximin optimal designs
Silver Conducting Lines of Dye-sensitized Solar Cells Printed onto Commercial Building Tiles
AbstractWe report a novel design and experimental results of dye-sensitized solar cell (DSSC) modules using commercial building tiles as one bottom substrate. In the study, the low-cost tiles as being one common part of the present buildings were employed for solar energy conversion unit here. Silver conducting lines consisting of nano-size particles were directly inkjet-printed onto their non-uniform surfaces of the tiles, thereby forming a grid-type pattern of counter electrodes. After sintering at elevated temperatures, the silver-printed tile was bonded together with a TiO2-coated ITO (indium tin oxide) glass substrate immersed in N719 dye solution. The bonded substrates were injected with electrolyte and sealed by thin Polydimethysiloxane (PDMS) film to generate a DSSC device. This DSSC built on the tile basis showed an electric voltage of 0.51V in the experiment. It is expected to be further developed for the building application for solar energy in the future
Analytical Studies on a Modified Nagel-Schreckenberg Model with the Fukui-Ishibashi Acceleration Rule
We propose and study a one-dimensional traffic flow cellular automaton model
of high-speed vehicles with the Fukui-Ishibashi-type (FI) acceleration rule for
all cars, and the Nagel-Schreckenberg-type (NS) stochastic delay mechanism. By
using the car-oriented mean field theory, we obtain analytically the
fundamental diagrams of the average speed and vehicle flux depending on the
vehicle density and stochastic delay probability. Our theoretical results,
which may contribute to the exact analytical theory of the NS model, are in
excellent agreement with numerical simulations.Comment: 3 pages previous; now 4 pages 2 eps figure
RESISTANT CAPITAL, ACTIVISM, AND THE MENTAL HEALTH AND WELL-BEING OF ADOLESCENTS
The extant literature on mental health and psychological well-being of adolescents in the United States has provided considerable insight into the factors that contribute to their overall functioning as well as how these resources and supports can be conceptualized and organized. One understudied theoretical orientation and its related constructs is Community Cultural Wealth (CCW) and its subconstructs of cultural capital. Cultural capital is particularly useful in helping conceptualize the supports and resources of minority, at-risk, and marginalized groups who may not possess or value the same types of tools or assets as their peers who belong to majority groups. Within CCW, resistant capital is understudied compared to other forms such as family or social capital despite how it is conceptualized to include ways in which individuals and groups are socialized, an individual’s attachment and perceptions of belonging, resisting subordination, and advocating for social justice and equality. Resistant capital and its subconstructs are also relatively understudied in their individual and collective contribution to adolescent mental health and well-being. Utilizing the National Longitudinal Study of Adolescent to Adult Health (Add-health) Wave I dataset, four variables of cultural capital were constructed (family, social, aspirational, and resistant) and subjected to three analytical procedures to understand their relationship to mental health and well-being. Preliminary results showed significant relationships of resistant capital to mental health and well-being. These findings included a significant correlation between resistant capital and variables of mental health and well-being. In addition, resistant capital as an independent variable was shown to have a significant association with mental health and well-being while also having some significant associations to mental health and well-being as a covariate with biological sex, race/ethnicity, and immigrant status. Finally, significant differences in mental health and well-being outcomes were observed between sociodemographic groups when resistant capital is a covariate; these comparison groups consisted of male versus female, white versus non-white, and immigrant versus non-immigrant. The implications of these findings are discussed in relation to understanding mental health and well-being in adolescents and future directions for interventions and inquiry.Doctor of Philosoph
Global Optimization of Minority Game by Smart Agents
We propose a new model of minority game with so-called smart agents such that
the standard deviation and the total loss in this model reach the theoretical
minimum values in the limit of long time. The smart agents use trail and error
method to make a choice but bring global optimization to the system, which
suggests that the economic systems may have the ability to self-organize into a
highly optimized state by agents who are forced to make decisions based on
inductive thinking for their limited knowledge and capabilities. When other
kinds of agents are also present, the experimental results and analyses show
that the smart agent can gain profits from producers and are much more
competent than the noise traders and conventional agents in original minority
game.Comment: 5 pages, 5 figure
14-3-3Ï„ Regulates Beclin 1 and Is Required for Autophagy
Beclin 1 plays an essential role in autophagy; however, the regulation of Beclin 1 expression remains largely unexplored. An earlier ChIP-on-chip study suggested Beclin 1 could be an E2F target. Previously, we also reported that 14-3-3tau regulates E2F1 stability, and is required for the expression of several E2F1 target genes. 14-3-3 proteins mediate many cellular signaling processes, but its role in autophagy has not been investigated. We hypothesize that 14-3-3tau could regulate Beclin 1 expression through E2F1 and thus regulate autophagy.Using the RNAi technique we demonstrate a novel role for one of 14-3-3 isoforms, 14-3-3tau, in the regulation of Beclin 1 expression and autophagy. Depletion of 14-3-3tau inhibits the expression of Beclin 1 in many different cell lines; whereas, upregulation of 14-3-3tau induces Beclin 1. The regulation is physiologically relevant as an extracellular matrix protein tenascin-C, a known 14-3-3tau inducer, can induce Beclin 1 through 14-3-3tau. Moreover, rapamycin-induced, serum free-induced and amino acid starvation-induced autophagy depends on 14-3-3tau. We also show the expression of Beclin 1 depends on E2F, and E2F can transactivate the Beclin 1 promoter in a promoter reporter assay. Upregulation of Beclin 1 by 14-3-3tau requires E2F1. Depletion of E2F1, like 14-3-3tau, also inhibits autophagy.Taken together, this study uncovers a role for 14-3-3tau in Beclin 1 and autophagy regulation probably through regulation of E2F1
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