2,370 research outputs found
Adaptive targeting in online advertisement: models based on relative influence of factors
We consider the problem of adaptive targeting for real-time bidding for internet advertisement. This problem involves making fast decisions on whether to show a given ad to a particular user. For demand partners, these decisions are based on information extracted from big data sets containing records of previous impressions, clicks and subsequent purchases. We discuss several criteria which allow us to assess the significance of different factors on probabilities of clicks and conversions. We then devise simple strategies that are based on the use of the most influential factors and compare their performance with strategies that are much more computationally demanding. To make the numerical comparison, we use real data collected by Crimtan in the process of running several recent ad campaigns
Toxic intracellular anabolite levels of tenofovir and didanosine causing a steep CD4-cell decline
Mechanism of life-long maintenance of neuron identity despite molecular fluctuations.
Cell fate is maintained over long timescales, yet molecular fluctuations can lead to spontaneous loss of this differentiated state. Our simulations identified a possible mechanism that explains life-long maintenance of ASE neuron fate in Caenorhabditis elegans by the terminal selector transcription factor CHE-1. Here, fluctuations in CHE-1 level are buffered by the reservoir of CHE-1 bound at its target promoters, which ensures continued che-1 expression by preferentially binding the che-1 promoter. We provide experimental evidence for this mechanism by showing that che-1 expression was resilient to induced transient CHE-1 depletion, while both expression of CHE-1 targets and ASE function were lost. We identified a 130 bp che-1 promoter fragment responsible for this resilience, with deletion of a homeodomain binding site in this fragment causing stochastic loss of ASE identity long after its determination. Because network architectures that support this mechanism are highly conserved in cell differentiation, it may explain stable cell fate maintenance in many systems
In vivo knock-down of multidrug resistance transporters ABCC1 and ABCC2 by AAV-delivered shRNAs and by artificial miRNAs
ABC transporters export clinically-relevant drugs and their over-expression causes multidrug resistance. In order to knock-down ABC transporters, ABCC1 and ABCC2, 13 shRNAs were developed. Four shRNA candidates were tested in vivo using self-complementary adeno-associated virus serotype 8. A strong, specific knock-down of Abbc2 was observed in mice liver, but at the cost of toxicity caused by oversaturation of the RNAi machinery due to high shRNA expression. Subsequent generation of artificial miRNAs showed better efficacy profile. These results demonstrate the feasibility of knocking down Abbc2 via AAV-delivered shRNAs to the liver, and encourage the use of miRNA in further therapeutics development
DC-STAMP knock-down deregulates cytokine production and T-cell stimulatory capacity of LPS-matured dendritic cells
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96778.pdf (publisher's version ) (Open Access)ABSTRACT: BACKGROUND: Dendritic cells (DCs) are the highly specialized antigen presenting cells of the immune system that play a key role in regulating immune responses. DCs can efficiently initiate immune responses or induce tolerance. Due to this dual function, DCs are studied in the context of immunotherapy for both cancer and autoimmune diseases. Characterization of DC-specific genes, leading to better understanding of DC immunobiology, will help to guide their use in clinical settings. We previously identified DC-STAMP, a multi-membrane spanning protein preferentially expressed by DCs. DC-STAMP resides in the endoplasmic reticulum (ER) of immature DCs and translocates towards the Golgi compartment upon maturation. In this study we knocked down DC-STAMP in mouse bone marrow-derived DCs (mBMDCs) to determine its function. RESULTS: We demonstrate that DC-STAMP knock-down mBMDCs secrete less IL-6, IL-12, TNF-alpha and IL-10 while IL-1 production is enhanced. Moreover, LPS-matured DC-STAMP knock-down mBMDCs show impaired T cell activation potential and induction of Th1 responses in an alloreaction. CONCLUSIONS: We show that DC-STAMP plays an important role in cytokine production by mBMDCs following LPS exposure. Our results reveal a novel function of DC-STAMP in regulating DC-initiated immune responses
Trans-eQTLs Reveal That Independent Genetic Variants Associated with a Complex Phenotype Converge on Intermediate Genes, with a Major Role for the HLA
This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
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