47 research outputs found

    fMRI Evidence for a Dual Process Account of the Speed-Accuracy Tradeoff in Decision-Making

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    Background: The speed and accuracy of decision-making have a well-known trading relationship: hasty decisions are more prone to errors while careful, accurate judgments take more time. Despite the pervasiveness of this speed-accuracy tradeoff (SAT) in decision-making, its neural basis is still unknown. Methodology/Principal Findings: Using functional magnetic resonance imaging (fMRI) we show that emphasizing the speed of a perceptual decision at the expense of its accuracy lowers the amount of evidence-related activity in lateral prefrontal cortex. Moreover, this speed-accuracy difference in lateral prefrontal cortex activity correlates with the speedaccuracy difference in the decision criterion metric of signal detection theory. We also show that the same instructions increase baseline activity in a dorso-medial cortical area involved in the internal generation of actions. Conclusions/Significance: These findings suggest that the SAT is neurally implemented by modulating not only the amount of externally-derived sensory evidence used to make a decision, but also the internal urge to make a response. We propose that these processes combine to control the temporal dynamics of the speed-accuracy trade-off in decisionmaking

    The role of sialomucin CD164 (MGC-24v or endolyn) in prostate cancer metastasis

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    BACKGROUND: The chemokine stromal derived factor-1 (SDF-1 or CXCL12) and its receptor CXCR4 have been demonstrated to be crucial for the homing of stem cells and prostate cancers to the marrow. While screening prostate cancers for CXCL12-responsive adhesion molecules, we identified CD164 (MGC-24) as a potential regulator of homing. CD164 is known to function as a receptor that regulates stem cell localization to the bone marrow. RESULTS: Using prostate cancer cell lines, it was demonstrated that CXCL12 induced both the expression of CD164 mRNA and protein. Functional studies demonstrated that blocking CD164 on prostate cancer cell lines reduced the ability of these cells to adhere to human bone marrow endothelial cells, and invade into extracellular matrices. Human tissue microarrays stained for CD164 demonstrated a positive correlation with prostate-specific antigen levels, while its expression was negatively correlated with the expression of androgen receptor. CONCLUSION: Our findings suggest that CD164 may participate in the localization of prostate cancer cells to the marrow and is further evidence that tumor metastasis and hematopoietic stem cell trafficking may involve similar processes

    Theiler's Murine Encephalomyelitis Virus as a Vaccine Candidate for Immunotherapy

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    The induction of sterilizing T-cell responses to tumors is a major goal in the development of T-cell vaccines for treating cancer. Although specific components of anti-viral CD8+ immunity are well characterized, we still lack the ability to mimic viral CD8+ T-cell responses in therapeutic settings for treating cancers. Infection with the picornavirus Theiler's murine encephalomyelitis virus (TMEV) induces a strong sterilizing CD8+ T-cell response. In the absence of sterilizing immunity, the virus causes a persistent infection. We capitalized on the ability of TMEV to induce strong cellular immunity even under conditions of immune deficiency by modifying the virus to evaluate its potential as a T-cell vaccine. The introduction of defined CD8+ T-cell epitopes into the leader sequence of the TMEV genome generates an attenuated vaccine strain that can efficiently drive CD8+ T-cell responses to the targeted antigen. This virus activates T-cells in a manner that is capable of inducing targeted tissue damage and glucose dysregulation in an adoptive T-cell transfer model of diabetes mellitus. As a therapeutic vaccine for the treatment of established melanoma, epitope-modified TMEV can induce strong cytotoxic T-cell responses and promote infiltration of the T-cells into established tumors, ultimately leading to a delay in tumor growth and improved survival of vaccinated animals. We propose that epitope-modified TMEV is an excellent candidate for further development as a human T-cell vaccine for use in immunotherapy

    Novel Functions of Renin Precursors in Homeostasis and Disease

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    Controlling Soil and Water Acidity in Acid Sulfate Soil Terrains Using Permeable Reactive Barriers

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    © 2019, Springer Nature Singapore Pte Ltd. There are about 12–14 million ha of acid sulfate soils (ASSs) found throughout the length and breadth of the earth. Bridge and building foundations, pipelines, culverts, and other buried infrastructure in such acidic environments are deteriorated when they are exposed to higher acidity, which is generated due to leaching of sulfuric acid from ASS. Thus, acidic groundwater should be properly treated to avoid detrimental effects on natural environment and strenuous efforts on repairing damaged manmade structures. Since the early 90s, permeable reactive barriers (PRBs) were implemented in several places worldwide and it was proven that PRBs are capable of competently treating poor-quality groundwater with various contaminants. While the acidic groundwater flows through a PRB, contaminants (toxic cations) are removed by mineral precipitation and due to the chemical reactions occur, a near-neutral pH is maintained in the effluent. Nevertheless, longevity of the PRB is alleviated due to coupled clogging in porous media. Physical, chemical, and biological clogging mechanisms and the existing PRB design criteria have been critically reviewed in this paper, including precursory numerical models. It is imperative to extend existing equations and models combining all possible clogging mechanisms, to assure the maximum acid removal capacity of a PRB. Hence, water and soil quality would be enhanced to make the land safe for transport and other infrastructure developments
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