The main object of this article is to give two novel proofs of the admissibility of Ackermann’s rule (γ) for the propositional relevant logic R. The results are established as corollaries of cut elimination for systems of tableaux for R. Cut elimination, in turn, is established both nonconstructively (as a corollary of completeness) and constructively (using Gentzen-like methods). The extensibility of the techniques is demonstrated by showing that (γ) is admissible for RQ* (R with constant domain quantifiers). The status of the admissibility of (γ) for RQ* was, to the best of the author’s knowledge, an open problem. Further extensions of these results will be explored in the sequel(s).

Despite the critical role of working memory (WM) in neuropsychiatric conditions, there remains a dearth of available WM-targeted interventions. Gamma and theta oscillations as measured with electroencephalography (EEG) or magnetoencephalography (MEG) reflect the neural underpinnings of WM. The WM processes that fluctuate in conjunction with WM demands are closely correlated with WM test performance, and their EEG signatures are abnormal in several clinical populations. Novel interventions such as transcranial magnetic stimulation (TMS) have been shown to modulate these oscillations and subsequently improve WM performance and clinical symptoms. Systematically identifying pathological WM-related gamma/theta oscillatory patterns with EEG/MEG and developing ways to target them with interventions such as TMS is an active area of clinical research. Results hold promise for enhancing the outcomes of our patients with WM deficits and for moving the field of clinical neuropsychology towards a mechanism-based approach.

The gamma-ray exposure build-up factors of raw materialsof bricks (soils and fly-ashes) in the state of Punjab were investigatedfor the photon energy range 0.015 to 15 MeV up to 40 mfp penetrationdepth by the geometrical progression (GP) method. Appreciable variationsin the exposure build-up factor (EBF) are noted for the raw materials.The EBFs of the raw materials of bricks change depending on thephoton energy, penetration depth and chemical composition. The build-up factorsare low at low and high photon energies, whereas they are very highin the medium-energy region. The peak energy of the EBF for soilsis 0.3 MeV and 0.2 MeV for fly ashes. The EBFs of the raw materialsof bricks are also compared with those of bricks of red mud andcommon brick materials. Common bricks were found to have the lowestgamma-ray EBF. This study should be useful for emergency preparednessplanning and emergency dose estimation for future planned nuclearpower plants in the state of Punjab.

Gamma-ray energy absorption buildup factors of gaseousmixtures; neon (95%) + argon (5%), argon (95%) + acetylene (5%),argon (95%) + methane (5%), argon (95%) + carbon dioxide (5%), methane(70%) + pentane (30%) and argon (90%) + methane (10%) were studiedby Geometrical Progression (G-P) fitting for the photon energy range0.015-15 MeV. It was found that the equivalent atomic number, Zeq ofthe gaseous mixtures sharply reduces after 1 MeV photon energy. TheZeq for the mixture of methane (70%) + pentane (30%)is the minimum, whereas the maximum is for argon (95%) + carbondioxide (5%) for the photon energies under investigation. The EnergyAbsorption Buildup Factor (EABF) for methane (70%) + pentane (30%)was found to be the highest among all the selected gaseous mixtures.The chemical composition of the gaseous mixtures has an impact onthe EABF values for photon energy and penetration depth. The investigationof the EABF is useful for selection of gaseous mixtures in designconsideration of gaseous radiation detectors for gamma radiation.

In order to study the vertical migration of anthropogenic 137Cs, soil inventories ofthis radionuclide were measured in two regions selected on the basisof a previous comprehensive survey in the northern Iranian provinceof Guilan located in the South Caspian region. Ten sampling stations were randomly chosen in these regions and split-level samplingwas carried out to a depth of 30 cm. Sample analysis was performedusing a HPGe detector system. In situ gamma measurementsin both regions were als o carried out with the aid of a portable germanium spectrometer.The experimental data were then compared with the solution of theconvection-dispersion equation (CDE) with the proper initial and boundary conditions to evaluate initialdeposition as well as transport parameter values. The solution,including the effects of both considered sources, i.e. global falloutand Chernobyl releases, fits the measured data well. The effectiveconvection velocity and dispersion coefficients of 137Cslie in the range of 0-0.25 cm·y-1 and 0.32-0.75 cm2·y-1, respectively, indicating a very slow migration rate in the area. Most of the deposited 137Cs still remainedin the top 10-cm layer. Moreover, the fitted depth profiles werethen employed to correct the surface activities of 137Csestimated by in situ measurements.

As established in early studies, the basalo-cortical system serves as an extra-thalamic relay from the brainstem reticular activating system to the cerebral cortex. As Mircea Steriade documented, activating impulses are transmitted through either the nonspecific thalamo-cortical projection system or the basalo-cortical projection system to stimulate widespread, fast, cortical activity that is characteristic of the activation that occurs naturally during waking (W) and paradoxical sleep (PS) states. However, basal forebrain (BF) neurons are different from thalamic neurons in several ways. First, many cortically projecting BF neurons utilize acetylcholine (ACh), which has a crucial role in stimulating fast cortical activity. Second, ACh-releasing neurons discharge selectively during W and PS and cease firing during slow-wave sleep (SWS). Third, ACh-releasing neurons discharge rhythmically in bursts during cortical activation and can, thus, modulate the cortex in a slow rhythmic manner to facilitate coherent activity across broad cortical networks. Fourth, the rhythmic discharge by BF neurons that release ACh, GABA or glutamate and project to the cortex occurs at respiratory or theta frequencies of the olfactory and limbic cortices, which reveals the particular importance of these inputs as well as outputs within basalo-cortico-basalo circuits. Fifth, other noncholinergic BF neurons, including GABA-releasing neurons, are active selectively during sleep: some of these potentially promote slow-wave activity during SWS through cortical projections; and others might promote behavioral quiescence during SWS and PS through descending projections. Finally, BF neurons also project to the thalamus and might, thus, either recruit or join thalamic neurons in modulating cortical activity across the sleep–waking cycle.

Abnormal thalamocortical dynamics have been proposed as the underlying mechanism for a subset of neurological and psychiatric disorders that include centrally generated pain. Spectral analysis and independent component-based localization of neuromagnetic signals reveal ongoing theta-range activity localized to physiologically significant cortical regions in a group of subjects with well-characterized central and peripheral lesions. In addition, recordings from subjects who failed to obtain relief from spinal cord stimulation (SCS) and from those in whom SCS was successful further delineate thalamocortical dysrhythmias as a mechanism that underlies chronic pain.

The paper investigates stochastic processes directed by a randomized time process. A new family of directing processes called Hougaard processes is introduced. Monotonicity properties preserved under subordination, and dependence among processes directed by a common randomized time are studied. Results for processes subordinated to Poisson and stable processes are presented. Potential applications to shock models and threshold models are also discussed. Only Markov processes are considered.

Discrete time extremal processes with a continuous underlying c.d.f. are random measures which can be viewed as two-dimensional Poisson processes and this representation is used to obtain the conditional law of the sequence of states the process passes through (upper record values) given the sequence of holding times in states (inter-record times). In addition the Gamma processes (which lead to the Ferguson Dirichlet processes) and a random measure that arises in sampling from a biological population are discussed as two-dimensional Poisson processes.