Electronic properties of CuO2 planes

We study a 3-band model of CuO₂ with “bare bones” interactions: hopping from copper ions to nearest-neighbor oxygenst _pd only, a two-body interaction on the copper ionsU _dd only, and an overlap copper-oxygen parameter λ_pd. In the limitt _pd ∝U _dd ^1/2→∞, t^*=t _pd ²/2U _dd is the unit of energy with 8λ_pd ² as the only parameter of significance. If the two-body interaction is invariant under particle-hole interchange, the low-lying states (energy O(t^*)) can be described by conserved particles and can all be classified. They are quite distinct from the high-lying states (energies O(U _dd)). The dynamics of the conserved fermion-like elementary particles are well described by a modifiedt-J model with extended hopping and nearest-neighbor superexchange attraction. This is a scenario known to be favorable to high-temperature superconductivity, but it must be noted that both the hopping range and the exchange are functions of 8λ_pd ². Moreover, if the Hamiltonian isnot invariant under particle-hole interchange the dynamics becomes much more complex and possibly more inimical to high-temperature superconductivity. This may provide an explanation for the deleterious effect on superconductivity of very small concentrations of certain impurities.     

The course of geriatric depression with "reversible dementia": a controlled study

OBJECTIVE: The goals of this longitudinal investigation were 1) to study the rate of development of irreversible dementia in elderly depressed patients with a dementia syndrome that subsided after improvement of depression and 2) to compare it with that of depressed, never-demented patients. METHOD: The subjects were 57 elderly patients consecutively hospitalized for major depression. At entry into the study, 23 subjects also met criteria for "reversible dementia," while 34 were without dementia. After a systematic clinical evaluation, the subjects were followed up at approximately yearly intervals for an average of 33.8 months. RESULTS: Irreversible dementia developed significantly more frequently in the depressed group with reversible dementia (43%) than in the group with depression alone (12%). Survival analysis showed that the group with reversible dementia had a 4.69-times higher chance of having developed dementia at follow-up than the patients with depression alone. No clinical characteristics at entry into the study were found to discriminate the subjects who developed irreversible dementia during the follow-up period from those who remained nondemented. CONCLUSIONS: These findings suggest that geriatric depression with reversible dementia is a clinical entity that includes a group of patients with early-stage dementing disorders. Therefore, identification of a reversible dementia syndrome is an indication for a thorough diagnostic workup and frequent follow-ups in order to identify treatable neurological disorders.     

Energy content of the nonexplosive excavation of rock by excavators with a dynamic scoop

Conclusions  

Long-term effects of behavior therapy: A 12-month follow-up.

19 female undergraduates who underwent various behavioral treatments designed to reduce a specific fear were paid to return for follow-up 1 yr. later. In general, treated Ss' rat fears were less intense 1 yr. after treatment than they had been prior to treatment, with those treated by systematic desensitization slightly less fearful than those treated with "rational therapy." Subsequently, the desensitized Ss eliminated a snake fear by themselves, but the effects of this self-administered desensitization were not maintained. Additionally, 6 children treated by operant conditioning techniques for various problems were reevaluated 1 yr. later. All behavior change was maintained, but only those who had graduated to social reinforcement showed additional improvement. No evidence for symptom substitution was obtained from either group of Ss. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Nature-oriented open coal mining technologies using mined-out space in an open pit. Part I: Analysis of the current mineral mining methods

An analysis is performed into the currently applied coal mining methods using mined-out space in an open pit, with describing their basic advantages and disadvantages. The urgency of further development and wider application of the gritwise-and-capwise methods that involve differently directed advance of a mining front and mined-out space utilized to the limit for overburden storage is pointed out. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 6, pp. 111–118, November–December, 2006.     

Wrapping of Web Sources with restricted Query Interfaces by Query Tunneling

Information sources in the World Wide Web usually offer two different schemes to their users, an Interface Schema which the user can query and a Result Schema which the user can browse. Often the Interface Schema is more restricted than the Result Schema, moreover many sources offer keyword-search interfaces only. Thus query capabilities of such sources are very small and a useful integration into a mediator-based information system using query capabilities is almost impossible. We propose the Query Tunnelling architecture for the wrapping of these restricted web sources. Wrapping of sources by Query Tunneling hides restrictive query interfaces and makes such sources fully queryable based on their result schema. The process of Query Tunneling is divided into two main steps, Query Relaxation to make a higher order query suitable to a restricted interface and Result Restriction in order to filter the results using the original query.