An Analysis of the Effects of Delay of Reinforcement and Momentary Probabilities of Reinforcement on Interval Schedule Performance

In two experiments pigeons were exposed to VI and FI schedules and viii schedules approximating both VI and FI schedules. In experiment I, the probabilities of the VI and FI components in a Mixed FI VI schedule were manipulated to create schedule contingencies approximating simple VI or FI. In experiment II, the minimum and maximum inter-reinforcement intervals were manipulated to create schedule contingencies approximating simple VI or FI. The major finding of both of these experiments was that maximal control by the dimension of time occurred as FI contingencies were approximated. Control by any one temporal value in experiment I depended on its temporal separation from 100 seconds and the probability of reinforcement associated with 100 seconds. Control by any one temporal value in experiment II depended on its temporal separation from the minimum inter-reinforcement interval and 100 seconds. The results were discussed in terms of interval schedule control as a form of stimulus control. A third experiment was performed to examine possible relationships between the pause in FI performance and the subsequent scallop. The baseline condition was contaminated by a procedure which may have produced effects which overrode experimental manipulations. Finally, an experiment was suggested to demonstrate behavioral contrast along a temporal dimension. The argument that interval schedule control is a form of stimulus control rested on analogy and inference. A demonstration of behavioral contrast along a temporal dimension would demonstrate more directly that time is similar to other dimensions. Hence, the same principles could be used to explain schedule control as are used to explain stimulus control

The Post-Reinforcement Pause and Terminal Rate In Fixed-Interval Schedules

California Quail were exposed to fixed-interval schedules whose values ranged from FI 90 to FI 180. Post-reinforcement pause lengths and terminal rates were recorded and grouped into relative frequency distributions. The relative post-reinforcement pause length was found to be an increasing function of FI value such that at larger FI values a proportionally greater period of time was taken up by the post-reinforcement pause. Terminal rate (rate during the final 20% of the interval) was a decreasing function of FI value. The large amounts of variability in terminal rates observed indicated that terminal rate in fixed-interval schedules is not constant from interval to interval as is often reported in the literature. For a given subject, when overall rate of response for a session was plotted as a function of mean pause length for that session, no consistent relationship was found. Among the subjects there were two to three-fold differences in overall rate on FI 90, the only value to which all subjects were exposed. Differences among subjects in mean overall rates were correlated with differences in mean pause lengths, however. Thus, a subject\u27s performance on a fixed-interval schedule could be characterized in terms of pause length and overall rate although rate in any given session was not necessarily correlated with mean pause length for that session, Differences between subjects in mean overall rates were also correlated with differences in mean terminal rates

The Representation of Form, Field and Transformation in Psychotherapy

The material reported in this paper has grown out of an ongoing dialogue between a psychiatrist and a computer scientist. The former is concerned with the development of meaningful communication between an expert practitioner in psychotherapy and trainees especially within the context of supervision, and the latter with the characterisation of complex domains of knowledge in relation to the possible development of computer-based support systems. The challenge of the ongoing study reported here has been to analyse some of the key concepts in the psychiatrist’s domain of expertise with the result of developing a visual metaphor for helping to integrate and clarify these concepts

Eclipsing binaries in the open cluster Ruprecht 147. II: EPIC 219568666

We report our spectroscopic monitoring of the detached, grazing, and slightly eccentric 12 day double-lined eclipsing binary EPIC 219568666 in the old nearby open cluster Ruprecht 147. This is the second eclipsing system to be analyzed in this cluster, following our earlier study of EPIC 219394517. Our analysis of the radial velocities combined with the light curve from the K2 mission yields absolute masses and radii for EPIC 219568666 of M₁ = 1.121 ± 0.013 M☉ and R₁ = 1.1779 ± 0.0070 R☉ for the F8 primary and M₂ = 0.7334 ± 0.0050 M☉ and R₂ = 0.640 ± 0.017 R☉ for the faint secondary. Comparison with current stellar evolution models calculated for the known metallicity of the cluster points to a primary star that is oversized, as is often seen in active M dwarfs, but this seems rather unlikely for a star of its mass and with a low level of activity. Instead, we suspect a subtle bias in the radius ratio inferred from the photometry, despite our best efforts to avoid it, which may be related to the presence of spots on one or both stars. The radius sum for the binary, which bypasses this possible problem, indicates an age of 2.76 ± 0.61 Gyr, which is in good agreement with a similar estimate from the binary in our earlier study

GRS 1915+105: The first three months with INTEGRAL

GRS 1915+105 is being observed as part of an Open Time monitoring program with INTEGRAL. Three out of six observations from the monitoring program are presented here, in addition to data obtained through an exchange with other observers. We also present simultaneous RXTE observations of GRS 1915+105. During INTEGRAL Revolution 48 (2003 March 6) the source was observed to be in a highly variable state, characterized by 5-minute quasi-periodic oscillations. During these oscillations, the rise is faster than the decline, and is harder. This particular type of variability has never been observed before. During subsequent INTEGRAL revolutions (2003 March-May), the source was in a steady or ''plateau'' state (also known as class $\chi$ according to Belloni et al. 2000). Here we discuss both the temporal and spectral characteristics of the source during the first three months of observations. The source was clearly detected with all three gamma-ray and X-ray instruments onboard INTEGRAL.Comment: 7 pages, 12 figures. Proceedings of the 5th INTEGRAL Workshop, Munich 16-20 February 2004. ESA SP-552. High resolution version of Fig. 6 can be obtained from http://www.astro.helsinki.fi/~diana/Figure6.p

An action principle for the quantization of parametric theories and nonlinear quantum cosmology

By parametrizing the action integral for the standard Schrodinger equation we present a derivation of the recently proposed method for quantizing a parametrized theory. The reformulation suggests a natural extension from conventional to nonlinear quantum mechanics. This generalization enables a unitary description of the quantum evolution for a broad class of constrained Hamiltonian systems with a nonlinear kinematic structure. In particular, the new theory is applicable to the quantization of cosmological models where a chosen gravitational degree of freedom acts as geometric time. This is demonstrated explicitly using three cosmological models: the Friedmann universe with a massless scalar field and Bianchi type I and IX models. Based on these investigations, the prospect of further developing the proposed quantization scheme in the context of quantum gravity is discussed.Comment: 14 page

SITC cancer immunotherapy resource document: a compass in the land of biomarker discovery.

Since the publication of the Society for Immunotherapy of Cancer\u27s (SITC) original cancer immunotherapy biomarkers resource document, there have been remarkable breakthroughs in cancer immunotherapy, in particular the development and approval of immune checkpoint inhibitors, engineered cellular therapies, and tumor vaccines to unleash antitumor immune activity. The most notable feature of these breakthroughs is the achievement of durable clinical responses in some patients, enabling long-term survival. These durable responses have been noted in tumor types that were not previously considered immunotherapy-sensitive, suggesting that all patients with cancer may have the potential to benefit from immunotherapy. However, a persistent challenge in the field is the fact that only a minority of patients respond to immunotherapy, especially those therapies that rely on endogenous immune activation such as checkpoint inhibitors and vaccination due to the complex and heterogeneous immune escape mechanisms which can develop in each patient. Therefore, the development of robust biomarkers for each immunotherapy strategy, enabling rational patient selection and the design of precise combination therapies, is key for the continued success and improvement of immunotherapy. In this document, we summarize and update established biomarkers, guidelines, and regulatory considerations for clinical immune biomarker development, discuss well-known and novel technologies for biomarker discovery and validation, and provide tools and resources that can be used by the biomarker research community to facilitate the continued development of immuno-oncology and aid in the goal of durable responses in all patients

Measurement of the quasi-elastic axial vector mass in neutrino-oxygen interactions

The weak nucleon axial-vector form factor for quasi-elastic interactions is determined using neutrino interaction data from the K2K Scintillating Fiber detector in the neutrino beam at KEK. More than 12,000 events are analyzed, of which half are charged-current quasi-elastic interactions nu-mu n to mu- p occurring primarily in oxygen nuclei. We use a relativistic Fermi gas model for oxygen and assume the form factor is approximately a dipole with one parameter, the axial vector mass M_A, and fit to the shape of the distribution of the square of the momentum transfer from the nucleon to the nucleus. Our best fit result for M_A = 1.20 \pm 0.12 GeV. Furthermore, this analysis includes updated vector form factors from recent electron scattering experiments and a discussion of the effects of the nucleon momentum on the shape of the fitted distributions.Comment: 14 pages, 10 figures, 6 table

Evidence for the η_b(1S) Meson in Radiative Υ(2S) Decay

We have performed a search for the η_b(1S) meson in the radiative decay of the Υ(2S) resonance using a sample of 91.6 × 10^6 Υ(2S) events recorded with the BABAR detector at the PEP-II B factory at the SLAC National Accelerator Laboratory. We observe a peak in the photon energy spectrum at E_γ = 609.3^(+4.6)_(-4.5)(stat)±1.9(syst) MeV, corresponding to an η_b(1S) mass of 9394.2^(+4.8)_(-4.9)(stat) ± 2.0(syst) MeV/c^2. The branching fraction for the decay Υ(2S) → γη_b(1S) is determined to be [3.9 ± 1.1(stat)^(+1.1)_(-0.9)(syst)] × 10^(-4). We find the ratio of branching fractions B[Υ(2S) → γη_b(1S)]/B[Υ(3S) → γη_b(1S)]= 0.82 ± 0.24(stat)^(+0.20)_(-0.19)(syst)