Large N lattice QCD and its extended strong-weak connection to the hypersphere

We calculate an effective Polyakov line action of QCD at large Nc and large Nf from a combined lattice strong coupling and hopping expansion working to second order in both, where the order is defined by the number of windings in the Polyakov line. We compare with the action, truncated at the same order, of continuum QCD on S^1 x S^d at weak coupling from one loop perturbation theory, and find that a large Nc correspondence of equations of motion found in \cite{Hollowood:2012nr} at leading order, can be extended to the next order. Throughout the paper, we review the background necessary for computing higher order corrections to the lattice effective action, in order to make higher order comparisons more straightforward.Comment: 33 pages, 7 figure

Autoshaping Infant Vocalizations

A series of five experiments was conducted to determine whether operant or respondent factors controlled the emission of a particular vocalization ( Q ) by human infants 16 to 18 months old. Experiment 1 consisted of a pilot investigation of the effects of an autoshaping procedure on three infants\u27 vocal behavior. All three subjects demonstrated increased emission of the target sound during the CR period. Experiments 2 through 4 attempted to replicate the findings of Experiment 1 under controlled conditions, and failed to do so. Experiment 5a presented infant subjects with a discrete-trial operant procedure (having the identical temporal parameters as the autoshaping procedure used in Experiments 1 through 4) , during which subjects received rewards only after emitting the target sound. All three experimentally naive subjects in this condition emitted the target sounds, and each met an acquisition criterion of 15 successive trials with at least one target response (CR) per trial. Subjects in Experiment 5b were exposed to the autoshaping procedure employed in Experiments 1 through 4; in addition, they were rewarded verbally for emitting the target sound at any time during the session. One of these three subjects increased her rate of target sound emission, but never met the acquisition criterion. The results suggest that vocalizations of subjects in this age range are susceptible to response-reinforcer (operant) manipulations and not to stimulus-stimulus (Pavlovian) associations. This conclusion differs from the findings of previous investigations that used younger infant subjects, suggesting that subject age may be important when conditioning vocalizations. Further research is also recommended to determine the utility of employing autoshaping procedures with humans

Factors Affecting the Conditioned Reinforcing Strength of Stimuli in Differential Reinforcement of Other Behavior and Fixed-Time Schedules

Two experiments were conducted in an attempt to provide a direct, response-independent test of the delay-reduction hypothesis of conditioned reinforcement. In both experiments, pigeons made observing responses, by pressing a treadle, for stimuli associated with the schedule component in effect . The consequences of an observing response were varied; an observing response produced: a) either the stimulus associated with the shorter component or the stimulus associated with the longer component depending on the schedule component in effect; b) the stimulus associated with the short component only; c) the stimulus associated with the long component only; or, d) neigher stimulus (no consequence). In Experiment I, naive pigeons were initially exposed to a mixed schedule with two differential reinforcement of other (ORO) behavior components; 10 seconds and 30 seconds (Phase One). In the second phase the same birds were exposed to an identical schedule, but the components were fixed time (FT) components (Phase Two). Reinforcement in both phases was six seconds access to food. In Experiment II, naive pigeons were exposed to both phases of Experiment I., but reinforcement density was altered. Each 10 second component was followed by 3 seconds of food and each 30 second component was followed by 9 seconds of food. In both experiments, differential observing behavior was maintained during the FT (Phase Two) procedure but not during the ORO (Phase One) procedure. In addition, equalizing reinforcement density (Experiment II) had the effect of altering the pattern of observing behavior but did not reverse or eliminate the preference shown for the stimulus associated with the shorter delay to reinforcement over the stimulus associated with the longer delay to reinforcement. It is suggested that some characteristic of the DRO procedure may have been responsible for the lack of differential observing. While the delay-reduction hypothesis of conditioned reinforcement was supported by the results of theFT procedure of both experiments, some amendments are required to account for the lack of differential observing during theDRO procedure. Reinforcement density appeared to have little effect upon observing behavior, but further research is advised concerning its effect upon observing response patterns

Calculating the chiral condensate diagrammatically at strong coupling

We calculate the chiral condensate of QCD at infinite coupling as a function of the number of fundamental fermion flavours using a lattice diagrammatic approach inspired by recent work of Tomboulis, and other work from the 80's. We outline the approach where the diagrams are formed by combining a truncated number of sub-diagram types in all possible ways. Our results show evidence of convergence and agreement with simulation results at small Nf. However, contrary to recent simulation results, we do not observe a transition at a critical value of Nf. We further present preliminary results for the chiral condensate of QCD with symmetric or adjoint representation fermions at infinite coupling as a function of Nf for Nc = 3. In general, there are sources of error in this approach associated with miscounting of overlapping diagrams, and over-counting of diagrams due to symmetries. These are further elaborated upon in a longer paper.Comment: presented at the 32nd International Symposium on Lattice Field Theory (Lattice 2014), 23-28 June 2014, New York, NY, US

Synthesis and reactivity of low-valent uranium and neptunium complexes

Chapter 1 reports the synthesis and characterization of U(IV) and Np(IV) selenium bis(phenolate) complexes. The reaction of the U(IV) complex with half an equivalent of p-benzoquinone results in the formation of a U(V)--U(V) species with a bridging reduced quinone. This represents a rare example of high-valent uranium chemistry as well as a rare example of a neptunium aryloxide complex. In Chapters 2 and 3 the synthesis and characterization of a rare U(III) hydrocarbyl complex, U[[eta]4-Me2NC(H)C6H5]3, and the first structurally characterized transuranic hydrocarbyl complex, Np[[eta]4-Me2NC(H)C6H5]3, complex, has been generated with four equivalents of the K[Me2NC(H)C6H5] ligand. In the analogous Th(IV) reaction, C-H bond activation of a methyl group of one dimethylamine was observed yielding Th[[eta]4-Me2NC(H)C6H5]2[[eta]5-(CH2)MeNC(H)C6H5] with a dianionic DMBA ligand. The utility of these complexes as starting materials has been analyzed using a bulky dithiocarboxylate ligand to yield tetravalent actinide species for U and Th but Np maintains the trivalent oxidation state. Chapter 4 describes the on-going synthesis and reactivity of Np(OAr)3 (Ar = 2,6-di-tert-butylphenoxide) utilizing Np[[eta]4-Me2NC(H)C6H5]3 as a Np(III) starting material. The coordination and oxidation chemistry is explored with [nBu4N]N3, (C6H5CO)2O2 and Ph2S2 resulting in a bridged Np(III)/Np(III) azide complex with an outer sphere nBu4N and Np(IV) species, respectively.Includes bibliographical reference

Zuckerbergs or Luddites? The Use of Social Media by Senior Executives in the Banking Industry

Many organisations are starting to use social media for business purposes, although some industries are more advanced than others. This paper looks at the banking industry, and focuses specifically on how senior executives in this industry perceive social media and its value. Hence this paper is an exploratory interpretive study of the attitudes of senior banking executives to social media. Assuming that senior executives have a significant influence on the adoption of social media within their organization, this study throws some light on its potential uptake within the banking industry