Differential effects of hippocampectomy on classically conditioned rabbit nictitating membrane response related to interstimulus interval.

The effects of hippocampal ablation on acquisition rates and temporal characteristics of classically conditioned nictitating membrane responses were examined in 54 New Zealand albino rabbits trained with a 150-, 300-, or 600-msec interstimulus interval. Acquisition rates were accelerated in the 150- and 600-msec groups. No effect was present in the 300-msec group. Response onset latencies were also affected in the 150-msec group. Results indicate that damage to the hippocampus influences the acquisition of classically conditioned responses only when temporal parameters are relatively complex. Findings also support the notion that the hippocampus modulates learned motor behavior by a neural model of the response to be executed. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The science and practice of empirically supported treatments.

The impact on Canadian professional psychological treatment practices of the American Psychological Association""s Division 12 (Clinical Psychology) Task Force""s development of criteria and listings for empirically supported psychological treatments, along with other industrial efforts to standardize the identification of treatments with established efficacy is described in the article by J. Hunsley et al (see record 1999-01869-001). Here Hunsley et al extend their previous discussion and reply to other commentaries (see records 1999-01869-002, 1999-01869-003, 1999-01869-004, 1999-01869-005, 1999-01869-006) by viewing the current emphases in the Canadian health care system on accountability and empirically supported treatment (ESTs) as an unparalleled opportunity for professional psychology to deliver on its birthright. The generalizability of US experiences to Canadian contexts is discussed. Clinical practice guidelines should and will become the norm for providing evidence-based services in psychology, yet it would be impossible to develop such a guideline without empirical evidence proving that there are "best" interventions for a given problem. Canadian research issues in this light are discussed along with future challenges to professional psychology in Canada. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Yellow–green organic light-emitting diode based on tris(2-methyl-8-quinolinolate) scandium

Efficient yellow–green electroluminescence emission at λ_max = 530 nm with CIE coordinates x = 0.3913, y = 0.4947 was obtained with organic light-emitting devices based on tris(2-methyl-8-quinolinolate) scandium (1). The device with the configuration of indium tin oxide/N,N′-bis(3-methylphenyl)-N,N′-diphenylbenzidine/1/Yb exhibits current efficiency of 3.1 cd/A and power efficiency of 1.8 lm/W at a luminance of 100 cd/m². The DFT calculations demonstrate that structural changes of the scandium complex 1 influence the electroluminescence spectrum, the better agreement with experimental data being achieved when monodentate ligands are taken into consideration.     

The first ribbed functionalized tris-dioximate clathrochelates with inherent hydroxyl substituents: Synthesis, spectra and X-ray structure

The controlled hydrolysis of the dichlorine-containing iron(II) clathrochelate FeBd₂(Cl₂Gm)(BF)₂ precursor (where Bd²⁻ and Cl₂Gm²⁻ are α-benzyldioxime and dichloroglyoxime dianions, respectively) afforded the hydroxy-containing clathrochelate derivatives with the hydroxyl substituent inherently bound to the ribbed chelate fragment of the macrobicyclic ligand. The triethylammonium and tetra-n-butylammonium salts of the clathrochelate [FeBd₂(OClGm)(BF)₂]⁻ anion have been characterized using elemental analysis, MALDI-TOF mass spectrometry, IR, UV–Vis, ⁵⁷Fe Mössbauer and ¹H, ¹³C{¹H}, ¹¹B and ¹⁹F NMR spectroscopies, and X-ray crystallography. The X-ray structural data for this deprotonated anion showed strong delocalization of its negative charge into the clathrochelate framework.     

Non-linear analysis of FRP chimneys under thermal and wind loads

Due to their high corrosion and chemical attack resistance, Fiber Reinforced Plastic materials (FRP) are increasingly being used in the construction of industrial chimneys. To the best of the authors' knowledge, the current study represents the first analytical investigation aimed at describing the behavior of FRP chimneys under the effect of both thermal and wind loads. The study is conducted numerically using a consistent shell element model which includes the effect of large deformations. A simple material non-linearity model that accounts for cracks occurring in the resin is added to the shell element model. The finite element model is used to describe the typical structural behavior of FRP chimneys, assess the effect of cracking and determine the critical through-thickness temperature profile.     

Failure of hippocampectomy to facilitate classical conditioning at an optimal interstimulus interval is not due to a "ceiling effect."

Examined the effects of amphetamine injection (2 mg/kg), hippocampal lesions, and cortical lesions in 30 naive New Zealand albino rabbits during classical conditioning of the rabbit nictitating membrane response. An optimal interstimulus interval (ISI) was employed. Whereas neocortical and hippocampal damage had no significant effect on the rate of acquisition, amphetamine treatment produced a marked facilitation. A control group of amphetamine-treated Ss receiving explicitly unpaired presentations of the conditioned stimulus/stimuli (CS) and unconditioned stimulus/stimuli (UCS) failed to exceed spontaneous response rates throughout training. The failure of hippocampectomy to accelerate conditioning under an optimal ISI does not appear to be due to a ceiling effect. Rather, it is suggested that the response system is predisposed to conditioned responses of a given latency. Optimal ISIs may fall within this range. Thus, in short or long intervals, temporal aspects of the motor response must be adjusted to conform to the stimulus configuration. It appears that the hippocampus is a likely source of response modulation. Thus, loss of hippocampal input accelerates conditioning under nonoptimal intervals at the expense of proper timing. Conditioning under an optimal interval would occur at normal rates because no modulation is required. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Oxidative dehydrogenation of propane over monoliths at short contact times

A specially designed tubular microreactor with independent control of feed preheat as well as catalyst temperature and allowing to rapidly quench reaction products was used to test performance of supported Pt-based monolithic catalysts in the reaction of propane oxidative dehydrogenation at short contact times. To minimize the impact of undesired homogeneous reactions capable of decreasing propylene selectivity, proprietary straight-channel thin-wall high cell density corundum micromonoliths were chosen as supports. Catalytic properties of supported platinum were modified by using promoters known as dehydrogenation catalysts (tin, zinc aluminate spinel, transition metal pyrophosphates) as well as by tuning reaction mixture composition (propane/oxygen ratio, water and hydrogen content). In the operation temperature range up to 900°C with contact times 0.03–0.1 s, ethylene/propylene selectivities were found to strongly depend upon the chemical composition of the active component and type of feed. The results thus obtained demonstrate that for Pt-based catalysts, propylene yield can be substantially improved by suppressing secondary reactions of deep oxidation and cracking.