205 research outputs found

    SUNYATA IN THE WEST

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    I argue that sunyata, or something like it, manifested itself in early Western thought. While Plato and Aristotle resisted emptiness or nothingness, they nevertheless felt themselves obliged to venture close to its edge in order to ground their explanations of changing reality to unchanging principles. These principles (Plato’s receptacle and Aristotle’s prime matter) embody much of the indeterminancy long associated with the Mahayana understanding of sunyata. Although their function was to enable lasting (static) explanations of reality by putting change out of play, they themselves shade off toward a featureless being evocative of non-being. Moving along a somewhat different track, Greek atomists embraced emptiness (or void) so as to permit self-existent, fully self-contained atoms to move about. In their system, non-being, a foundational principle of reality, paradoxically coexists with being. Interestingly, modern science has undone the self-containment of atoms—emptied them of properties once thought to be innate—and thereby removed yet another Western safeguard against change. It seems that change cannot be put out of play, though it does slope off toward sunyata-like emptiness

    Competitive advantage as a legitimacy-creating process

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    Purpose – The purpose of this paper is to explore how small firms in the tattooing industry actively shape institutional expectations of value for consumers in a changing industry. Design/methodology/approach – The paper draws upon interviews with key actors in the firms under study to explore their experiences with consumers and other constituents in determining how competitive advantage is constructed in this environment. These data are complemented data with interviews with governmental representatives and material from secondary sources. Findings – The results reveal efforts of firms to construct and increase organizational legitimacy through the prominence of discourses of professionalism based on artistry and medicine/public health. These bases of competitive differentiation are not the clear result of exogenous pressure, rather they arise through the active efforts of the firm to construct value guidelines for consumers and other constituents. Practical implications – Strategic management in small firms is a complex and dynamic process that does not necessarily mirror that of large organizations. Constructing competitive advantage is an interacting process between key actors of small firms and various constituents. Originality/value – The paper extends the application of institutional theory in strategic management by illuminating the active role that firms play in creating industry norms, especially in industries where norms are not well established or no longer entrenched. Moreover, exploring an alternative site of study offers a means through which to see well-studied issues in new ways

    Quantum Uncertainty, Quantum Play, Quantum Sorrow

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    I argue that intrinsic (as opposed to epistemic or Einsteinian) quantum uncertainty informs the elemental life experiences of random play and compassionate sorrow. These experiences, like Niels Bohr's quantum ontology, point toward unscripted novelty, fresh variation, and far-flung sympathetic interconnections. And in doing this, they allow the inner and outer feeling experiences to grow back together. As we feel the world sensibly”that is, touch it with our sense organs”it touches back in a way that engenders feeling-laden or sympathetic understanding

    Conceptual Nonlocality

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    Nonlocality is a puzzling issue in modern physics. I propose that, aside from the experimental determination of nonlocality, the concept of atomistic lightmdash;discrete, self-bounded photonsmdash;breaks down toward something like nonlocality when subjected to philosophical scrutiny. Louis de Broglie made a similar argument regarding the material atom: the concept of the classical atom, when interrogated, collapses upon itself to offer a glimpse of wave-particle duality. Light atoms or photons, I argue, similarly collapse toward the contradictory possibility of nonlocality

    Meson Form-factors and Wave-functions with Wilson fermions

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    Results for semi-leptonic form-factors for processes like D→KlÎœD \to K l \nu and the Bethe-Salpeter amplitudes (BSA) for pion and rho mesons are presented. The form-factor data is consistent with previous calculations. We find that the long distance fall-off of BSA for both π\pi and ρ\rho is very well fit by an exponential, but surprisingly the effective mass governing this fall-off is lighter than the pion's. Lastly, by studying the dependence of ρ\rho polarization on separation direction we show that there is a measureable l=2l=2 state in addition to l=0l=0 in the BSA for the rho. (Talk presented by R. Gupta at LATTICE92. Latex needs macro package espcrc2.sty)Comment: 4 pages including 4 PS figure

    Dopamine D(2 )receptors mediate two-odor discrimination and reversal learning in C57BL/6 mice

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    BACKGROUND: Dopamine modulation of neuronal signaling in the frontal cortex, midbrain, and striatum is essential for processing and integrating diverse external sensory stimuli and attaching salience to environmental cues that signal causal relationships, thereby guiding goal-directed, adaptable behaviors. At the cellular level, dopamine signaling is mediated through D(1)-like or D(2)-like receptors. Although a role for D(1)-like receptors in a variety of goal-directed behaviors has been identified, an explicit involvement of D(2 )receptors has not been clearly established. To determine whether dopamine D(2 )receptor-mediated signaling contributes to associative and reversal learning, we compared C57Bl/6J mice that completely lack functional dopamine D(2 )receptors to wild-type mice with respect to their ability to attach appropriate salience to external stimuli (stimulus discrimination) and disengage from inappropriate behavioral strategies when reinforcement contingencies change (e.g. reversal learning). RESULTS: Mildly food-deprived female wild-type and dopamine D(2 )receptor deficient mice rapidly learned to retrieve and consume visible food reinforcers from a small plastic dish. Furthermore, both genotypes readily learned to dig through the same dish filled with sterile sand in order to locate a buried food pellet. However, the dopamine D(2 )receptor deficient mice required significantly more trials than wild-type mice to discriminate between two dishes, each filled with a different scented sand, and to associate one of the two odors with the presence of a reinforcer (food). In addition, the dopamine D(2 )receptor deficient mice repeatedly fail to alter their response patterns during reversal trials where the reinforcement rules were inverted. CONCLUSIONS: Inbred C57Bl/6J mice that develop in the complete absence of functional dopamine D(2 )receptors are capable of olfaction but display an impaired ability to acquire odor-driven reinforcement contingencies. Furthermore, the ability of dopamine D(2 )receptor deficient mice to adjust their responding to a previously reinforced stimulus when unexpected outcomes are encountered is significantly impaired. These findings suggest that signaling mediated by the dopamine D(2 )receptor is important for regulating associative and reversal learning and may have implications for the treatment of human attention disorders

    The Science and Sociology of Hunting: Shifting Practices and Perceptions in the United States and Great Britain

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    Between the late nineteenth and early twenty-first centuries, both the rationale for and perception of hunting shifted in the United States, coinciding with demographic changes in the U.S. population (Duda 1993). Similar changes in attitude, though largely undocumented, probably occurred in the United Kingdom. (For example, foxhunting did not emerge as a substantial sport until the second half of the eighteenth century; before that, foxes were widely perceived as pests and killed whenever the opportunity arose [Marvin 2000]). Our purpose in this chapter is to compare these two countries in order to reveal some of the science and the sociology relevant to hunting (the latter just one of many interacting environmental issues about which human society faces complicated judgments within rapidly shifting political and cultural areas)

    Failure of Intravenous Morphine to Serve as an Effective Instrumental Reinforcer in Dopamine D2 Receptor Knock-Out Mice

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    The rewarding effects of opiates are thought to be mediated through dopaminergic mechanisms in the ventral tegmental area, dopamine-independent mechanisms in the nucleus accumbens, or both. The purpose of the present study was to explore the contribution of dopamine to opiate-reinforced behavior using D2 receptor knock-out mice. Wild-type, heterozygous, and D2 knock-out mice were first trained to lever press for water reinforcement and then implanted with intravenous catheters. The ability of intravenously delivered morphine to maintain lever pressing in these mice was studied under two schedules of reinforcement: a fixed ratio 4 (FR4) schedule (saline, 0.1, 0.3, or 1.0 mg/kg, per injection) and a progressive ratio (PR) schedule (1.0 mg/kg, per injection). In the wild-type and heterozygous mice, FR4 behavior maintained by morphine injections was significantly greater than behavior maintained by vehicle injections. Response rate was inversely related to injection dose and increased significantly in the wild-type and heterozygous mice when the animals were placed on the PR schedule. In contrast, the knock-out mice did not respond more for morphine than for saline and did not respond more when increased ratios were required by the PR schedule. Thus, morphine served as a positive reinforcer in the wild-type and heterozygous mice but failed to do so in the knock-out mice. Under this range of doses and response requirements, the rewarding effects of morphine appear to depend critically on an intact D2 receptor systemFil: Elmer, Greg I.. University of Maryland; Estados UnidosFil: Pieper, Jeanne O.. National Institutes of Health; Estados UnidosFil: Rubinstein, Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Low, Malcolm J.. Oregon Health and Sciences University; Estados UnidosFil: Grandy, David K.. Oregon Health and Sciences University; Estados UnidosFil: Wise, Roy A.. National Institutes of Health; Estados Unido

    Dysfunctional Light-Evoked Regulation of cAMP in Photoreceptors and Abnormal Retinal Adaptation in Mice Lacking Dopamine D4 Receptors

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    Dopamine is a retinal neuromodulator that has been implicated in many aspects of retinal physiology. Photoreceptor cells express dopamine D4 receptors that regulate cAMP metabolism. To assess the effects of dopamine on photoreceptor physiology, we examined the morphology, electrophysiology, and regulation of cAMP metabolism in mice with targeted disruption of the dopamine D4 receptor gene. Photoreceptor morphology and outer segment disc shedding after light onset were normal in D4 knock-out (D4KO) mice. Quinpirole, a dopamine D2/ D3/D4 receptor agonist, decreased cAMP synthesis in retinas of wild-type (WT) mice but not in retinas of D4KO mice. In WT retinas, the photoreceptors of which were functionally isolated by incubation in the presence of exogenous glutamate, light also suppressed cAMP synthesis. Despite the similar inhibition of cAMP synthesis, the effect of light is directly on the photoreceptors and independent of dopamine modulation, because it was unaffected by application of the D4 receptor antagonist L-745,870. Nevertheless, compared with WT retinas, basal cAMP formation was reduced in the photoreceptors of D4KO retinas, and light had no additional inhibitory effect. The results suggest that dopamine, via D4 receptors, normally modulates the cascade that couples light responses to adenylyl cyclase activity in photoreceptor cells, and the absence of this modulation results in dysfunction of the cascade. Dark-adapted electroretinogram (ERG) responses were normal in D4KO mice. However, ERG b-wave responses were greatly suppressed during both light adaptation and early stages of dark adaptation. Thus, the absence of D4 receptors affects adaptation, altering transmission of light responses from photoreceptors to inner retinal neurons. These findings indicate that dopamine D4 receptors normally play a major role in regulating photoreceptor cAMP metabolism and adaptive retinal responses to changing environmental illumination.Fil: Nir, Izhak. The University of Texas Health Science Center; Estados UnidosFil: Harrison, Joseph M.. The University of Texas Health Science Center; Estados UnidosFil: Haque, Rashidul. Emory University School of Medicine; Estados UnidosFil: Low, Malcolm J.. Oregon Health and Science University; Estados UnidosFil: Grandy, David K.. Oregon Health and Science University; Estados UnidosFil: Rubinstein, Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Iuvone, P. Michael. Emory University School of Medicine; Estados Unido

    Conditioned place preference and locomotor activity in response to methylphenidate, amphetamine and cocaine in mice lacking dopamine D4 receptors

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    Methylphenidate (MP) and amphetamine (AMPH) are the most frequently prescribed medications for the treatment of attention-deficit/hyperactivity disorder (ADHD). Both drugs are believed to derive their therapeutic benefit by virtue of their dopamine (DA)-enhancing effects, yet an explanation for the observation that some patients with ADHD respond well to one medication but not to the other remains elusive. The dopaminergic effects of MP and AMPH are also thought to underlie their reinforcing properties and ultimately their abuse. Polymorphisms in the human gene that codes for the DA D4 receptor (D4R) have been repeatedly associated with ADHD and may correlate with the therapeutic as well as the reinforcing effects of responses to these psychostimulant medications. Conditioned place preference (CPP) for MP, AMPH and cocaine were evaluated in wild-type (WT) mice and their genetically engineered littermates, congenic on the C57Bl/6J background, that completely lack D4Rs (knockout or KO). In addition, the locomotor activity in these mice during the conditioning phase of CPP was tested in the CPP chambers. D4 receptor KO and WT mice showed CPP and increased locomotor activity in response to each of the three psychostimulants tested. D4R differentially modulates the CPP responses to MP, AMPH and cocaine. While the D4R genotype affected CPP responses to MP (high dose only) and AMPH (low dose only) it had no effects on cocaine. Inasmuch as CPP is considered an indicator of sensitivity to reinforcing responses to drugs these data suggest a significant but limited role of D4Rs in modulating conditioning responses to MP and AMPH. In the locomotor test, D4 receptor KO mice displayed attenuated increases in AMPH-induced locomotor activity whereas responses to cocaine and MP did not differ. These results suggest distinct mechanisms for D4 receptor modulation of the reinforcing (perhaps via attenuating dopaminergic signalling) and locomotor properties of these stimulant drugs. Thus, individuals with D4 receptor polymorphisms might show enhanced reinforcing responses to MP and AMPH and attenuated locomotor response to AMPH.Fil: Thanos, P. K.. NIAAA Intramural Program; Estados Unidos. Brookhaven National Laboratory; Estados Unidos. Universidad de Buenos Aires; ArgentinaFil: Bermeo, C.. Brookhaven National Laboratory; Estados UnidosFil: Rubinstein, Marcelo. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; Argentina. Universidad de Buenos Aires; ArgentinaFil: Suchland, K. L.. Oregon Health & Science University; Estados UnidosFil: Wang, G. J.. Brookhaven National Laboratory; Estados UnidosFil: Grandy, David K.. Oregon Health & Science University; Estados UnidosFil: Volkow, N. D.. NIAAA Intramural Program; Estados Unido
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