17,294 research outputs found
Review of 'Education in Parapsychology: Student and Instructor Perspectives' by Harvey Irwin
Book review of Education in Parapsychology: Student and Instructor Perspectives by Harvey Irwin. Foreword by Nancy Zingrone. Gladesville, NSW, Australia: AIPR Mongraphs, 2013. Pp xv + 106. (paperback). ISBN 9780987077219
Psychophysical evidence for competition between real and illusory contour processing
Luminance defined and illusory contours provide vital information about object borders. However, real and illusory contour cues tend to be used under different contexts and can interfere with one another. Although some cells in visual cortex process both real and illusory contours equivalently, recent studies (Ramsden et al 2001) suggest competitive interactions between real (feedforward) and illusory (feedback) contour processing in primate V1 and V2. To test this hypothesis psychophysically, we designed stimuli in which illusory contours are presented with and without the presence of real line components. If real and illusory contour cues are processed by the same mechanism, then the presence of both cues should enhance the percept. If the illusory percept is degraded by the presence of real lines, then independent real and illusory mechanisms are suggested. The perception of a Kanisza-triangle, presented for 250 msec, was measured under three conditions: 1) virtual contour alone, 2) with a short parallel real line superimposed on the virtual contour or 3) with a short orthogonal real line abutting the virtual contour. The real lines were varied from sub- to supra-threshold contrasts. In a 2AFC paradigm three subjects fixated on a spot in the triangle center and indicated whether the side of the triangle was bent outwards or inwards. We found that real lines degraded the percept of the illusory contour (i.e. increased angular thresholds). Such interference occurred even at subthreshold real line contrasts and, in some subjects, was greater for the parallel than orthogonal real line. Our results support the presence of separate mechanisms for the processing of real and illusory contours and suggest that, under some circumstances, real cues can interfere with the processing of illusory cues. We suggest that such interferences occurs by the feedforward influences of the lines which interfere with the feedback influences prominent during illusory contour processing
Two meta-analyses of noncontact healing studies
Reviews of empirical work on the efficacy of noncontact healing have found that interceding on behalf of patients through prayer or by adopting various practices that incorporate an intention to heal can have some positive effect upon their wellbeing. However, reviewers have also raised concerns about study quality and the diversity of healing approaches adopted, which makes the findings difficult to interpret. Some of these concerns can be addressed by adopting a standardised approach based on the double-blind randomised controlled clinical trial, and a recent review restricted to such studies has reported a combined effect size of .40 (p < .001). However, the studies in this review involve human participants for whom there can be no guarantee that control patients are not beneficiaries of healing intentions from friends, family or their own religious groups. We proposed to address this by reviewing healing studies that involved biological systems other than âwholeâ humans (i.e. to include animal and plant work but also work involving human biological matter such as blood samples or cell cultures), which are less susceptible to placebo and expectancy effects and also allow for more circumscribed outcome measures. Secondly, doubts have been cast concerning the legitimacy of some of the work included in previous reviews so we planned to conduct an updated review that excluded that work. For phase 1, 49 non-whole human studies from 34 papers were eligible for review. The combined effect size weighted by sample size yielded a highly significant r of .258. However the effect sizes in the database were heterogeneous, and outcomes correlated with blind ratings of study quality. When restricted to studies that met minimum quality thresholds, the remaining 22 studies gave a reduced but still significant weighted r of .115. For phase 2, 57 whole human studies across 56 papers were eligible for review. When combined, these studies yielded a small effect size of r = .203 that was also significant. This database was also heterogeneous, and outcomes were correlated with methodological quality ratings. However, when restricted to studies that met threshold quality levels the weighted effect size for the 27 surviving studies increased to r = .224. Taken together these results suggest that subjects in the active condition exhibit a significant improvement in wellbeing relative to control subjects under circumstances that do not seem to be susceptible to placebo and expectancy effects. Findings with the whole human database gave a smaller mean effect size but this was still significant and suggests that the effect is not dependent upon the previous inclusion of suspect studies and is robust enough to accommodate some high profile failures to replicate. Both databases show problems with heterogeneity and with study quality and recommendations are made for necessary standards for future replication attempts
Perspectives on time and the chronometric study of what happens in organizations
An often made distinction in the study of time in organizations is that between objective,linear, homogeneous, linear, measurable, Newtonian time, also called Chronos, andsubjective, non-linear, heterogeneous, experienced, event time, also designated as Kairos.These conceptions of time are associated with the positivistic and the interpretativeapproaches to organizational research. Are these conceptions of time incompatible? Andare there two mutually exclusive ways of gaining scholarly knowledge about time inorganizations? This paper proposes that the two notions of time can be meaningfullycombined by accepting the possibility of mutual âreflectionâ, that is, the interpretation ofmeasured time, and the measurement of interpreted time. By adding the postulate ofârecursivityâ, which entails reflection at successive (higher order) levels, a broad range ofoptions for inquiry into the temporality of organizational phenomena unfolds, that allowsfor the use of chronometric as well as interpretative methods. It is noted that prevailingpositivistic and interpretative approaches have both lead to a dramatic neglect ofmeasured time in organizational research. Therefore, the remainder of this paper focuseson the chronometric study of organizations. It proposes a research agenda which coverstemporal phenomena at multiple analytical levels, including those of the individual, thegroup and the organization as a whole. Since objective as well as subjective definitions ofphenomena are considered, the scope of this chronometric approach and its descriptiveand explanatory potential appear to be substantial.Economics ;
Response of MarineâTerminating Glaciers to Forcing: Time Scales, Sensitivities, Instabilities, and Stochastic Dynamics
Recent observations indicate that many marineâterminating glaciers in Greenland and Antarctica are currently retreating and thinning, potentially due to longâterm trends in climate forcing. In this study, we describe a simple twoâstage model that accurately emulates the response to external forcing of marineâterminating glaciers simulated in a spatially extended model. The simplicity of the model permits derivation of analytical expressions describing the marineâterminating glacier response to forcing. We find that there are two time scales that characterize the stable glacier response to external forcing, a fast time scale of decades to centuries, and a slow time scale of millennia. These two time scales become unstable at different thresholds of bed slope, indicating that there are distinct slow and fast forms of the marine ice sheet instability. We derive simple expressions for the approximate magnitude and transient evolution of the stable glacier response to external forcing, which depend on the equilibrium glacier state and the strength of nonlinearity in forcing processes. The slow response rate of marineâterminating glaciers indicates that current changes at some glaciers are set to continue and accelerate in coming centuries in response to past climate forcing and that the current extent of change at these glaciers is likely a small fraction of the future committed change caused by past climate forcing. Finally, we find that changing the amplitude of natural fluctuations in some nonlinear forcing processes, such as ice shelf calving, changes the equilibrium glacier state
An Open Economy Model of Political Influence and Competition Among Rent Seeking Groups
The paper develops a formal model of government's economic decisions as influenced by private agents within the context of neoclassical political economy. The government is assumed to form preferences over interest groups in the economy; in turn these preferences are influenced by the rent seeking behavior of these groups. An open, two-household, two-sector general equilibrium model is constructed to depict an environment in which preference-maximizing (rational) individuals allocate otherwise productive labor to directly unproductive rent seeking activities in order to exert political pressure on the government's choice of policy instruments. With the aid of five comparative-static experiments, the game-theoretic component and the second-best nature of the rent seeking environment is discussed. Insights are also provided on the influence of technological change, and changes in lobbying efficiency on resources allocated to rent seeking by interest groups. Key words: Rent Seeking, Political Economy, General Equilibrium.Political Economy,
Minimal kernels of Dirac operators along maps
Let be a closed spin manifold and let be a closed manifold. For maps
and Riemannian metrics on and on , we consider
the Dirac operator of the twisted Dirac bundle . To this Dirac operator one can associate an index
in . If is -dimensional, one gets a lower bound for
the dimension of the kernel of out of this index. We investigate
the question whether this lower bound is obtained for generic tupels
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