Functional Dysregulations in CA1 Hippocampal Networks of a 3-Hit Mouse Model of Schizophrenia

For a better translation from treatment designs of schizophrenia to clinical efficiency, there is a crucial need to refine preclinical animal models. In order to consider the multifactorial nature of the disorder, a new mouse model associating three factors (genetic susceptibility—partial deletion of the MAP6 gene, early-life stress—maternal separation, and pharmacological treatment—chronic Δ-9-tetrahydrocannabinol during adolescence) has recently been described. While this model depicts a schizophrenia-like phenotype, the neurobiological correlates remain unknown. Synaptic transmission and functional plasticity of the CA1 hippocampal region of male and female 3-hit mice were therefore investigated using electrophysiological recordings on the hippocampus slice. While basal excitatory transmission remained unaffected, NMDA receptor (NMDAr)-mediated long-term potentiation (LTP) triggered by theta-burst (TBS) but not by high-frequency (HFS) stimulation was impaired in 3-hit mice. Isolated NMDAr activation was not affected or even increased in female 3-hit mice, revealing a sexual dimorphism. Considering that the regulation of LTP is more prone to inhibitory tone if triggered by TBS than by HFS, the weaker potentiation in 3-hit mice suggests a deficiency of intrinsic GABA regulatory mechanisms. Indeed, NMDAr activation was increased by GABA_A receptor blockade in wild-type but not in 3-hit mice. This electrophysiological study highlights dysregulations of functional properties and plasticity in hippocampal networks of 3-hit mice, one of the mechanisms suspected to contribute to the pathophysiology of schizophrenia. It also shows differences between males and females, supporting the sexual dimorphism observed in the disorder. Combined with the previously reported study, the present data reinforce the face validity of the 3-hit model that will help to consider new therapeutic strategies for psychosis.     

Influence of the Temperature on Coccolith-Containing Systems from Emiliania huxleyi Cultivations

Thermogravimetric analysis of a coccolith-containing biogenic broth showed a three-step degradation process. According to this system behavior, the biogenic broth was heated to specific temperatures and characterized in terms of its morphology, surface chemistry, and crystallinity. The elemental and organic composition of the treated samples was also evaluated and compared to the reference material. The presented results were acquired in an effort to exploit pretreatment scenarios for such a biogenic system that would improve and support a separation process.     

Motor fluency deficits in the sequencing of actions in schizophrenia.

Many everyday activities depend on the capacity to organize and smoothly execute motor sequences. The authors tested the hypothesis that a sequencing deficit is associated with schizophrenia. They used a new method to distinguish between lower and higher order mechanisms for the impairment. The 1st task involved triggered sequences in which sensory information from 1 movement was the cue for initiation of the following movement. Results showed that the motor sequences were performed as fluently in patients as in controls. The 2nd and 3rd tasks involved sequences in which the entire movement sequence could be preplanned. Patients executed the sequences less fluently than controls but only under the condition where action sequences were required. Furthermore, the patients' fluency deficit increased with sequence complexity. The high discrimination power of Task 3 gave the authors a means to control for a potential psychometric confound involving differential discriminating power and to argue in favor of a specific higher order motor fluency deficit in patients with schizophrenia. It is suggested that basic lower order mechanisms that integrate sensory information with outgoing motor commands are preserved in schizophrenia, whereas higher order integrative mechanisms that are required for the smooth coordination of motor sequences are impaired. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On the Undecidability of Implications between Embedded Multivalued Database Dependencies

The implication and finite implication problems for embedded multivalued database dependencies are both shown to be algorithmically undecidable. The proof is by an interpretation of semigroup word problems via systems of permuting equivalence relations into database dependencies. In contrast, it is shown that for each fixed premise H one has a decision procedure for implications H F.     

CMOS on FZ-high resistivity substrate for monolithic integration ofSiGe-RF-circuitry and readout electronics

The choice of a highly resistive substrate for silicon millimeter-wave integrated circuits (SIMMWIC) imposed by the requirement of low RF-substrate losses requires the adaptation of a CMOS process on float zone silicon (FZ). A comparison of n- and p-channel devices realized on high resistivity substrate (p-type, 5000 Ω·cm) and standard CMOS substrates (CZ, n-type, 4-6 Ω·cm) is given. Using careful process design, we obtained device characteristics on FZ-substrates that are closely similar to those on standard material, thus allowing direct transfer of existing circuit designs     

Erfolgsfaktoren bei der Einführung von Wissensmanagementsystemen in die Praxis

Neben der Gestaltung technischer Systeme zur Unterstützung des Wissensmanagements ist die Ausgestaltung organisatorischer Ma?nahmen gleichbedeutend wichtig.     

Pressure infiltration of boron nitride preforms with molten aluminum

The infiltration of compacted cubic BN (cBN) with molten aluminum has been investigated as a potential route for a cheap and easy method of manufacturing cBN/metal composites. CBN compacts have been infiltrated with molten Al at a temperature between 670 and 800 °C and pressure of 15 MPa in vacuum. At these temperatures no pronounced interactions between hexagonal and cubic BN with Al was observed, allowing the complete infiltration of cBN with 12 μm mean grain size. After infiltration at 800 °C, the temperature was increased without pressure to convert aluminum into borides and AlN. The hardness of the resulting materials depends on the content of hexagonal, cubic BN and the rate of conversion of Al into borides and AlN. The infiltration height of less than 1 mm obtained from infiltrating the 3 μm cBN powder green compacts gave a hardness of 22.0 ± 0.6 GPa after heat treatment.     

Validity of Three Measures of Communication for Predicting Relationship Adjustment and Stability Among a Sample of Young Couples.

The goal of this study was to examine whether data from 3 different measures of communication (i.e., self-report, quasi-observational, and observational) can predict relationship adjustment and stability 1 year later when used conjointly in a sample of 62 young couples. The 3 measures of communication were the Communication Skills Test-Revised (CST-R), the Communication Box (CB), and the Demand/Withdraw Pattern Questionnaire (DWPQ). Through hierarchical multiple regression analyses, results revealed that the CST-R and the DWPQ predict both genders' relationship adjustment 1 year later when used conjointly. Logistic regression analyses revealed that none of the measures of communication significantly predicted relationship stability. In conclusion, the combination of the CST-R and the DWPQ appears to be useful for longitudinally predicting relationship adjustment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)