Opposite effects of lateral septal LTP and lateral septal lesions on contextual fear conditioning in mice.

The effect of fimbrial high-frequency stimulation (HFS)-induced long-term potentiation (LTP) in the lateral septum (LS) on contextual fear conditioning was studied in mice. Mice were conditioned for fear toward a novel context through the use of footshocks. The 1st experiment showed that pretraining HFS reduced significantly conditional freezing to contextual stimuli. The 2nd experiment was designed to determine whether the reduction of freezing produced by fimbrial HFS resulted from LTP in the LS rather than from LTP in other brain structures. Accordingly, mice with lesions of the LS were used and submitted to the same protocol as in the 1st experiment. Results showed that LS lesions completely abolished the impairing effect of fimbrial HFS and, as a whole, potentiated the freezing response. These data suggest that contextual fear conditioning is strongly modulated by the level of hippocampal–LS synaptic neurotransmission. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Metacognitive awareness and prevention of relapse in depression: Empirical evidence.

Metacognitive awareness is a cognitive set in which negative thoughts/feelings are experienced as mental events, rather than as the self. The authors hypothesized that (1) reduced metacognitive awareness would be associated with vulnerability to depression and (2) cognitive therapy (CT) and mindfulness-based CT (MBCT) would reduce depressive relapse by increasing metacognitive awareness. They found (1) accessibility of metacognitive sets to depressive cues was less in a vulnerable group (residually depressed patients) than in nondepressed controls; (2) accessibility of metacognitive sets predicted relapse in residually depressed patients; (3) where CT reduced relapse in residually depressed patients, it increased accessibility of metacognitive sets; and (4) where MBCT reduced relapse in recovered depressed patients, it increased accessibility of metacognitive sets. CT and MBCT may reduce relapse by changing relationships to negative thoughts rather than by changing belief in thought content. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of dietary protein on the fatty acid composition and Δ6 desaturase activity of rat hepatic microsomes

Recently, significant differences between rats fed a casein diet and rats fed a soybean protein diet have been observed in hepatic phospholipid fatty acid patterns (Sjöblom, L., and Eklund, A.,Biochim. Biophys. Acta 1004, 187–192, 1990). The influence of these two diets on the Δ6 desaturase activity was investigated in the present study because the hepatic desaturase system is a source of unsaturated fatty acids. The rats fed a casein diet showed higher desaturase activity than those fed soybean protein when using either linoleic acid (P<0.005) or oleic acid (P<0.05) as substrates. The phosphatidylcholine fraction of hepatic microsomes showed increases in oleic acid (P<0.005) and 20∶3ω9 (P<0.001) levels as well as decreases in stearic acid (P<0.001), linoleic acid (P<0.005) and arachidonic acid (P<0.005) levels in rats which were fed casein rather than soybean protein. Similar differences between the two groups were also observed in the phosphatidylethanolamine and phosphatidylinositol fractions. These data indicate that the qualitative properties of the dietary protein source may influence the fatty acid pattern of rat hepatic microsomes by interfering with Δ6 desaturase activity.     

Vers les 20 kbit/s en transmission décamétrique ionosphérique : une application du traitement d’antenne sur des capteurs colocalisés

This paper presents an operational system of digital transmission within the h.f. frequency range, aiming at a significant increase of the data transfer rate compared with the current standard (4800 bit/s). Therefore, an array processing algorithm performs with a set of collocated sensors, the spatial responses of which are different one from each other. The dependence of the incoming polarization relatively to the direction of arrival induces a significant decorrelation of the received signals though no geometrical phase exists. Signal processing techniques run at the output of the spatial filter resorting for the synchronisation and the filtering (lms algorithm) to classical and well-tested techniques involving training sequences. An experimental radio link with a 250 km range has been set up to test the sensibility of the performances in reception regarding the choice of waveforms. The operational results reach the expected goal as the data transfer rate increases up to 20 kbit/s in a bandwidth of 6 kHz.     

Effects of double-bond configuration on interaction between a moth sex pheromone component and its receptor

The dependence of the electrophysiological activity on the change of double-bond configuration of (Z)-5-decenyl acetate, a pheromone component of the turnip moth,Agrotis segetum, and a dienic analog, (E)-2,(Z)-5-decadienyl acetate, have been investigated by single-cell measurements and molecular mechanics calculations (MM2). A previously reported model for the interaction between a moth sex pheromone component and its receptor has been refined. This new model gives an essentially quantitative correlation between the measured activities and the calculated conformational energies for a biologically active conformation defined by the model. Previously obtained structure-activity results for chain-elongated analogs of (Z)-5-decenyl acetate are significantly improved by the refined model. The effect of a change of the double-bond configuration on the substrate-receptor interaction is not additive but depends on the conformational properties of the entire molecule.     

Psychophysiological reactivity to mental arithmetic stress in Black and White normotensive men.

34 Black and 42 White male normotensives 34–55 yrs old performed a mental arithmetic task while blood pressure, heart rate, and skin conductance were recorded. Compared with Whites, Blacks had significantly higher baseline diastolic blood pressure and lower skin conductance levels. These effects persisted during performance of the mental arithmetic task. When baseline differences were covaried, there were no significant physiological effects associated with the task. There were no significant race or family history effects, and task performance did not influence the outcome. Failure to demonstrate greater cardiovascular reactivity in Blacks and all men with a positive family history of hypertension is discussed with regard to possible survivor effects and methodologic limitations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Measurement of CHn group abundances in fossil fuel materials using DEPT 13C n.m.r.

¹³C n.m.r. subspectra assigned to CH, CH₂ and CH₃ groups can be obtained in reasonably quantitative conditions by using the distortionless enhancement by polarization transfer (DEPT). The method has been applied to light and heavy petroleum materials.     

Microprocessor Control in Metallurgical Furnaces

The two microprocessor based controllers featured in this paper were developed with the philosophy of the distributed computing concept. The analog signals were digitized very close to the source, as well as the real-time functions. The following data demonstrate the continued trend towards taking the computational capability to the process instead of bringing the process to the computer. As the digital hardware continues to become more economical, it is expected that greater utilization of these types of systems will be seen in controlling and optimizing existing processes.     

Effects of sex and lesion locus on measures of intelligence.

Previous reports of the cognitive effects of lateralized brain damage in men and women have been conflicting, some suggesting significant differences in the pattern of intellectual deficits and others failing to do so. This article reports Wechsler Adult Intelligence Scale (WAIS) IQ data from 64 patients with cortical neoplasms confined to one of four brain quadrants. Analyses indicated a significant main effect for lesion laterality for verbal IQ scores (but not for performance IQ scores) as well as for verbal IQ–performance IQ difference scores. There were no significant main effects for sex or lesion site (in the anterior–posterior dimension) and no significant interactions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Recent changes in riparian vegetation: possible consequences on dead wood processing along rivers

Little is known about changes in the composition of dead wood jams along rivers and the possible consequences of any such changes on the river ecosystem. Although tree zonation along the upstream‐to‐downstream continuum is weak and highly variable from a system to another, a clear transition appears in the piedmont zone, which is reflected by transitions in dead wood sources as well as for dead wood transport, storage and decomposition processes. In this paper, we focus on large lowland rivers of southwestern France, where riparian vegetation is increasingly fragmented, reduced in area and/or is entirely replaced by planted forests (poplar plantations). The amount and the potential role of dead wood is practically unknown in these rivers. One reason is that French legislation obliges landowners and public service managers to remove all material from the stream in order to maintain unobstructed river flows. The other reason is that unlike pristine streams in northern regions, these rivers have been regulated for several decades (Adour River) or even for several centuries (Garonne River). The vegetation component of the managed riparian landscape has changed in particular as a result of i) a decrease in stream dynamics, ii) the replacement of natural forests by planted ones, and iii) the invasion of natural communities by introduced woody species. The possible consequences of biological invasions on the role of dead wood jams are discussed in light of: i) a local study of wood jams along a moderately modified system; ii) changes observed in the composition of trees along the Adour River over the past 10 years; iii) a regional case study involving two chosen species. Whereas white willow populations are declining along streams in southwestern France, the box‐elder, introduced from the United States, has spread extensively in the last two decades. Statistical models would suggest that competitive pressures are limited between these two species, boxelder is expected to replace white willow in the near future as a consequence of an increase in river regulation and global warming. This can be expected to have important consequences on dead wood dynamics, and on the management of woody debris, especially since trends indicate a replacement of softwood species by hardwood species. Copyright © 2003 John Wiley & Sons, Ltd.