Imagined empathy and attributions concerning activity preferences of physically disabled college students.

Investigated 89 college students' attributions about the activity preferences of able-bodied vs physically disabled peers and evaluated the effects of imagined empathy on attributional patterns and attitudes toward disabled people. Ss were asked to predict the responses of either a male or a female able-bodied or wheelchair-user college student to items on a 20-item questionnaire offering choices between gregarious–nongregarious activities and between active–passive activities. Results indicate that there was considerable variability in able-bodied students' attributions about disabled peers' activity preferences. Previous contact with disabled people was unrelated either to attitudes toward disabled people or to activity preference attributions. Asking students to imagine empathy for a disabled peer was not an effective technique to change either attributional patterns or attitudes toward disabled people. (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Principles and applications of ion beam techniques for the analysis of solids and thin films

This paper reviews in principle and by examples how a collimated mono-energetic and mono-atomic beam incident on a target provides information on its structure and composition when the energy of the back-scattered beam atoms, or of the particles generated by nuclear reactions, is analyzed. Examples are selected with particular emphasis on thin films and Si technology. For convenience, we define three different energy ranges of the incident beam (low energies from 1 to 6 keV, medium energies from 100 to 500 keV and high energies from 1 to 2 MeV) and discuss each range separately, according to the following table of contents.     

Review of Constructive evolution: Origins and development of Piaget's thought.

Reviews the book, Constructive evolution: Origins and development of Piaget's thought by Michael Chapman (see record 1988-97990-000). Canadian developmental psychologists have been among the harshest critics, most articulate supporters, and most creative extenders of Piaget's theory. Michael Chapman's book is in this reflective and interpretive tradition. Chapman's primary goal in the book is neither to criticize, support, nor extend Piaget's theory (although he does some of each), but to clarify the meaning of the theory, and to specify its domain of application. Chapman does this by tracing the growth of Piaget's thinking using Piaget's autobiographical papers as a map. The first six chapters comprise Chapman's historical analysis, which begins with Piaget's adolescence, a point in life where Piaget was later to say that cognitive development ends (although he was to retract the claim still later in his career). In the last two chapters of the book, Chapman uses his historical analysis to clarify the philosophical and psychological significance of Piaget's theory. Chapman's book is an excellent integration of Piaget's theory in that it places the theory in the context of the questions that motivated it. But for all the clarity that Chapman's historical analysis brings to Piaget's thought, the analysis opens a number of new questions. What Chapman has done successfully is to provide a view of the nature, limits, and future of Piagetian theory by examining its origins and evolution. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sparing of patterned alternation but not partial reinforcement extinction effect after prenatal chronic exposure to ethanol in infant rats.

The effects of in utero administration of ethanol on single patterned alternation (PA) and the partial reinforcement extinction effect (PREE) were studied in 15-day-old rat pups. This fetal-alcohol treatment had no effect on PA but eliminated the PREE by reducing persistence in extinction after partial reinforcement (PRF) training to its level after continuous reinforcement (CRF) training, which was not affected by the treatment. The results are discussed in terms of prenatal damage to the hippocampus and in relation to an earlier experiment (Lobaugh, Bootin, & Amsel, 1985), which found no effect of infant hippocampal lesions on PA but an elimination of the PREE, which, unlike the fetal-alcohol case, resulted from PRF-like persistence in extinction following CRF training. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evidence for a transitional period for development of persistence in infant rats.

Conducted 4 experiments with a total of 188 rat pups to test the hypothesis that rat pups can learn persistence at age 11 days but cannot express this learning in their behavior until they are a few days older. Exp I used a space-trial procedure to investigate the relative reinforcing effects of milk suckling, dry suckling, and contact without suckling at ages 11 and 14 days. Exp II used the Exp I procedure, manipulating schedule of reward at 2 ages and under 2 of the reward conditions. Exp III manipulated the dry suckling reward schedule in 11- and 14-day-old pups. Exp IV manipulated partial and continuous reinforcement on Day 11 but tested for persistence on Day 14. Results suggest the existence of a traditional period in neonatal rats for the learning of persistence. Partial reinforcement training with suckling on an anesthetized dam as reward induced greater persistence in extinction of the approach response than did continuous reinforcement in rat pups 14 days old but not in 11-day-old pups. Other aspects of this period of development are discussed. (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The NMDA antagonist MK-801 affects nonspatial learning in preweanling rats.

The N-methyl-{d}-aspartate (NMDA) subtype of the excitatory amino acid receptor has been implicated in several kinds of learning and memory, as well as in long-term potentiation (LTP), a putative cellular mechanism for learning and memory. This experiment examined the role of the NMDA receptor in patterned single-alternation (PSA) learning in preweanling rats following intraperitoneal injections of 0.05 mg/kg MK-801, a selective NMDA antagonist. MK-801 significantly inhibited PSA at both 60-sec and 30-sec intervals (ITIs). and attenuated, but did not block Iearning at 8-sec . These results are compared with effects on PSA, a form of nonspatial, memory-based learning, observed; after early postnatal exposure to alcohol, infant hippocampal lesions, and infant exposure to X-irradiation, and they add strongly to these earlier demonstrartions of the role of the hippocampus in learning and memory that is clearly nonspatial and non-cognitive-map-related. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Regulation of proliferation and production of prostate-specific antigen in androgen-sensitive prostatic cancer cells, LNCaP, by dihydrotestosterone

LNCaP is an androgen-sensitive human prostatic cancer cell line. The effect of androgen on these cells is characterized by a bell-shaped growth response and a dose-dependent induction of prostate-specific antigen (PSA) production. The present study was carried out to gain further insight into the effect of androgen on LNCaP. Cells were cultured in phenol red-free RPMI-1640 supplemented with 10% charcoal-stripped fetal bovine serum, with concentrations of dihydrotestosterone (DHT) ranging from 0-10(-7) M, in a 4-day culture system. A bell-shaped growth response was reproduced with a peak level of cell count at 10(-10) M DHT. PSA secretion from these cells did not increase significantly until the DHT level in the medium reached 10(-9) M. A progressive increase in PSA secretion was observed at higher DHT concentrations accompanied with a progressive decline in cellular proliferation. The results of immunocytochemical analysis of PSA localization indicated that the proportion of cells with positive staining for PSA also increased with increasing concentrations of DHT. Analysis of androgen receptors, as determined by both immunocytochemistry and Western blot analysis, showed a decline in nuclear androgen receptor at low concentrations of DHT and an increase in the amount of receptor protein at high concentrations. These results indicated that the androgen-induced bell-shaped growth response in LNCaP cells represented the manifestation of two different cellular events in dose-related manner: cellular proliferation at low DHT concentrations and increased production of PSA at high DHT concentrations.     

Age-dependent effects of hippocampal muscarinic receptor blockade on memory-based learning in the developing rat

In the male rat, testosterone has been shown to regulate gonadotrophin synthesis and secretion under experimental conditions such as castration or gonadotrophin-releasing hormone (GnRH) antagonist with or without testosterone. The present study aims at clarifying the effects of non-steroidal antiandrogens, Casodex and flutamide, and ethane dimethane sulphonate (EDS) on the regulation of gonadotropin synthesis and secretion. To enable a direct comparison within this study to expected effects of testosterone, a GnRH antagonist-treated group and a castrated group were included. The gene expression of the subunits was correlated with changes in the pituitary and plasma content of immunoreactive luteinizing hormone (LH) and follicle-stimulating hormone (FSH), free subunits and pituitary content of in vitro bioactive LH and FSH. Groups of ten male rats each received the following treatments for 7 days: (1) vehicle; (2) castration; (3) EDS (75 mg/kg); (4) GnRH antagonist (Cetrorelix 250 micrograms/kg/day), (5) Casodex (20 mg/kg/day) or (6) flutamide (20 mg/kg/day). The effectiveness of testosterone deprivation was demonstrated by the reduction of weight in androgen-dependent organs such as epididymides and seminal vesicles in the treated groups. Treatment with flutamide, EDS or castration significantly increased (p < 0.05) serum levels of LH, FSH and alpha-subunit, whereas serum gonadotrophin levels were decreased in the GnRH antagonist-treated group. alpha-Subunit mRNA levels were elevated in the castrated, EDS and flutamide group and LH-beta mRNA levels were increased in the castrated and EDS group. FSH-beta mRNA levels were increased in the castrated group and decreased in the GnRH antagonist group, but remained unchanged in the flutamide and EDS group.(ABSTRACT TRUNCATED AT 250 WORDS)     

Processing of Detector Signals at Very High Counting Rates for Precision Pulse-Height Analysis

Systems with naxiwum pulse flow capacity are discussed. It is shown that the upper limit of the permissible counting rates is set by pile up induced phenomriena, which are analyzed here. The best pulse stretching mode miinimizing pile up is peak value extraction. The basic statistical properties of such a device are investigated. These principles are applied to the design of an electronic system which comprises a fast amplifier, a high speed linear gate and a biased pulse stretcher. The noise properties of the anmplifier were studied using the autocorrelation function mreasured experimrentally. The system allows one to detect a particles with satisfactory pile up performances and negligible spectrum distortion in the presence of back-scattered protons up to 108 counts/sec. Applications to pulsed high energy accelerators are described.     

Extinction after regular and irregular reward schedules in the infant rat: influence of age and training duration

In many mammalian cells, ClC-3 volume-regulated chloride channels maintain a variety of normal cellular functions during osmotic perturbation. The molecular mechanisms of channel regulation by cell volume, however, are unknown. Since a number of recent studies point to the involvement of protein phosphorylation/dephosphorylation in the control of volume-regulated ionic transport systems, we studied the relationship between channel phosphorylation and volume regulation of ClC-3 channels using site-directed mutagenesis and patch-clamp techniques. In native cardiac cells and when overexpressed in NIH/3T3 cells, ClC-3 channels were opened by cell swelling or inhibition of endogenous PKC, but closed by PKC activation, phosphatase inhibition, or elevation of intracellular Ca2+. Site-specific mutational studies indicate that a serine residue (serine51) within a consensus PKC-phosphorylation site in the intracellular amino terminus of the ClC-3 channel protein represents an important volume sensor of the channel. These results provide direct molecular and pharmacological evidence indicating that channel phosphorylation/dephosphorylation plays a crucial role in the regulation of volume sensitivity of recombinant ClC-3 channels and their native counterpart, ICl.vol.