1,445 research outputs found

    Urban construction and safety project

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    Technology utilization projects in the area of urban construction and safety included the following: development of undercarpet and baseboard flat conductor cables, flood insurance studies, tornado safety engineering, the Project TECH house at the Langley Research Center, assistance to the City of Atlanta in their environmental habitability and resource allocation program, and market assessment of a solid state diesel engine controller. The flat conductor cable and the flood insurance studies are given particular attention

    Selective attention to conditioned stimuli in human discrimination learning: Untangling the effect of outcome prediction, valence, arousal and uncertainty

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    What are the neural mechanisms underlying this ability? Are they the same in humans as in other animals? And what are the consequences of damage to this attentional system? These are the questions that this book aims to answer.The preparation of this manuscript was supported by a MRC new investigator award to Lee Hogarth (G0701456)

    Drug cue reactivity involves hierarchical instrumental learning: evidence from a biconditional Pavlovian to instrumental transfer task

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    This is the final version of the article. Available from Springer Verlag via the DOI in this record.RATIONALE: Drug cue reactivity plays a crucial role in addiction, yet the underlying mechanisms are poorly understood. According to the binary associative account, drug stimuli retrieve an expectation of the drug outcome, which, in turn, elicits the associated drug-seeking response (S-O-R). By contrast, according to the hierarchical account, drug stimuli retrieve an expectation that the contingency between the drug-seeking response and the drug outcome is currently more effective, promoting performance of the drug-seeking response (S:R-O). METHODS: The current study discriminated between these two accounts using a biconditional Pavlovian-to-instrumental transfer (PIT) task with 128 alcohol drinkers. A biconditional discrimination was first trained in which two responses produced alcohol and food outcomes, respectively, and these response-outcome contingencies were reversed across two discriminative stimuli (SDs). In the PIT test, alcohol and food cues were compounded with the two SDs to examine their impact on percent alcohol choice in extinction. RESULTS: It was found that alcohol and food cues selectively primed choice of the response that earned that outcome in each SD (p < .001), and this effect was associated with participants' belief that cues signalled greater effectiveness of that response (p < .0001). CONCLUSIONS: The alcohol stimulus could not have selectively primed the alcohol-seeking response through binary S-O-R associations because the drug outcome was equally associated with both responses. Rather, the alcohol stimulus must have retrieved an expectation that the response-alcohol contingency available in the current context was more likely to be effective (S:R-O), which primed performance of the alcohol-seeking response.The work was supported by an ESRC PhD scholarship to Lorna Hardy

    Evidence of a Goal-Directed Process in Human Pavlovian-Instrumental Transfer

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    © 2017 APA, all rights reserved). Cues that signal rewards can motivate reward-seeking behaviors, even for outcomes that are not currently desired. Three experiments examined this phenomenon, using an outcome-selective Pavlovian-instrumental transfer (PIT) design and an outcome devaluation procedure. In Experiment 1, participants learned to perform one response to earn crisps points and another response to earn popcorn points. One outcome was then devalued by adulterating it to make it taste unpleasant. On test, overall response choice was biased toward the outcome that had not been devalued, indicating goal-directed control. Stimuli that signaled crisps and popcorn also biased instrumental response choice toward their respective outcomes (a PIT effect). Most importantly, the strength of this bias was not influenced by the devaluation manipulation. In contrast, Experiment 2 demonstrated that when stimuli signaled equal probability of the two outcomes, cue-elicited response choice was sensitive to the devaluation manipulation. Experiment 3 confirmed this conclusion by demonstrating a selective avoidance of the cued, devalued outcome. Together, these data support a goal-directed model of PIT in which expected outcome probability and value make independent contributions to response choice. (PsycINFO Database Recor

    Activation of Tri(2-Furyl)Phosphine at a Dirhenium Centre: Formation of Phosphido-Bridged Dirhenium Complexes

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    Reaction of tri(2-furyl)phosphine (PFu3) with [Re2(CO)10−n(NCMe)n] (n = 1, 2) at 40 °C gave the substituted complexes [Re2(CO)10−n(PFu3)n] (1 and 2), the phosphines occupying axial position in all cases. Heating [Re2(CO)10] and PFu3 in refluxing xylene also gives 1 and 2 together with four phosphido-bridged complexes; [Re2(CO)8−n(PFu3)n(μ-PFu2)(μ-H)] (n = 0, 1, 2) (3–5) and [Re2(CO)6(PFu3)2(μ-PFu2)(μ-Cl)] (6) resulting from phosphorus–carbon bond cleavage. A series of separate thermolysis experiments has allowed a detailed reaction pathway to be unambiguously established. A similar reaction between [Re2(CO)10] and PFu3 in refluxing chlorobenzene furnishes four complexes which include 1, 2, 6 and the new binuclear complex [Re2(CO)6(η1-C4H3O)2(μ-PFu2)2] (7). All new complexes have been characterized by a combination of spectroscopic data and single crystal X-ray diffraction studies

    Double Carbon−Hydrogen Activation of 2-Vinylpyridine: Synthesis of Tri- and Pentanuclear Clusters Containing the μ-NC\u3csub\u3e5\u3c/sub\u3eH\u3csub\u3e4\u3c/sub\u3eCH═C Ligand

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    Reactions of 2-vinylpyridine with the triruthenium complexes [Ru3(CO)12] and [Ru3(CO)10(μ-dppm)] leads to a previously unknown double carbon−hydrogen bond activation of the β-carbon of the vinyl group to afford the pentaruthenium and triruthenium complexes [Ru5(CO)14(μ4-C5H4CH═C)(μ-H)2] (1) and [Ru3Cl(CO)5(μ-CO)(μ-dppm)(μ3-NC5H4CH═C)(μ-H)] (2), respectively. Crystal structures reveal two different forms of bridging of the dimetalated 2-vinylpyridyl ligand, capping a square face in 1 and a triangular face in 2
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