Forebrain afferents to the rat dorsal raphe nucleus demonstrated by retrograde and anterograde tracing methods

The dorsal raphe nucleus through its extensive efferents has been implicated in a great variety of physiological and behavioural functions. However, little is know about its afferents. Therefore, to identify the systems likely to influence the activity of serotonergic neurons of the dorsal raphe nucleus, we re-examined the forebrain afferents to the dorsal raphe nucleus using cholera toxin b subunit and Phaseolus vulgaris-leucoagglutinin as retrograde or anterograde tracers. With small cholera toxin b subunit injection sites, we further determined the specific afferents to the ventral and dorsal parts of the central dorsal raphe nucleus, the rostral dorsal raphe nucleus and the lateral wings. In agreement with previous studies, we observed a large number of retrogradely-labelled cells in the lateral habenula following injections in all subdivisions of the dorsal raphe nucleus. In addition, depending on the subdivision of the dorsal raphe nucleus injected, we observed a small to large number of retrogradely-labelled cells in the orbital, cingulate, infralimbic, dorsal peduncular, and insular cortice, a moderate or substantial number in the ventral pallidum and a small to substantial number in the claustrum. In addition, we observed a substantial to large number of cells in the medial and lateral preoptic areas and the medial preoptic nucleus after cholera toxin b subunit injections in the dorsal raphe nucleus excepting for those located in the ventral part of the central dorsal raphe nucleus, after which we found a moderate number of retrogradely-labelled cells. Following cholera toxin b subunit injections in the dorsal part of the central dorsal raphe nucleus, a large number of retrogradely-labelled cells was seen in the lateral, ventral and medial parts of the bed nucleus of the stria terminalis whereas only a small to moderate number was visualized after injections in the other dorsal raphe nucleus subdivisions. In addition, respectively, a substantial and a moderate number of retrogradely-labelled cells was distributed in the zona incerta and the subincertal nucleus following all tracer injections in the dorsal raphe nucleus. A large number of retrogradely-labelled cells was also visualized in the lateral, dorsal and posterior hypothalamic areas and the perifornical nucleus after cholera toxin b subunit injections in the dorsal part of the central raphe nucleus and to a lesser extent following injections in the other subdivisions. We further observed a substantial to large number of retrogradely-labelled cells in the tuber cinereum and the medial tuberal nucleus following cholera toxin b subunit injections in the dorsal part of the central dorsal raphe nucleus or the lateral wings and a small to moderate number after injections in the two other dorsal raphe nucleus subdivisions. A moderate or substantial number of labelled cells was also seen in the ventromedial hypothalamic area and the arcuate nucleus following cholera toxin injections in the dorsal part of the central dorsal raphe nucleus and the lateral wings and an occasional or small number with injection sites located in the other subdivisions. Finally, we observed, respectively, a moderate and a substantial number of retrogradely-labelled cells in the central nucleus of the amygdala following tracer injections in the ventral or dorsal parts of the central dorsal raphe nucleus and a small number after injections in the other subnuclei. In agreement with these retrograde data, we visualized anterogradely-labelled fibres heterogeneously distributed in the dorsal raphe nucleus following Phaseolus vulgaris-leucoagglutinin injections in the lateral orbital or infralimbic cortice, the lateral preoptic area, the perifornical nucleus, the lateral or posterior hypothalamic areas, the zona incerta, the subincertal nucleus or the medial tuberal nucleus. (ABSTRACT TRUNCATED)     

Algorithm-based fault tolerance applied to high performance computing

We present a new approach to fault tolerance for High Performance Computing system. Our approach is based on a careful adaptation of the Algorithm-Based Fault Tolerance technique [K. Huang, J. Abraham, Algorithm-based fault tolerance for matrix operations, IEEE Transactions on Computers (Spec. Issue Reliable & Fault-Tolerant Comp.) 33 (1984) 518–528] to the need of parallel distributed computation. We obtain a strongly scalable mechanism for fault tolerance. We can also detect and correct errors (bit-flip) on the fly of a computation. To assess the viability of our approach, we have developed a fault-tolerant matrix–matrix multiplication subroutine and we propose some models to predict its running time. Our parallel fault-tolerant matrix–matrix multiplication scores 1.4 TFLOPS on 484 processors (cluster jacquard.nersc.gov) and returns a correct result while one process failure has happened. This represents 65% of the machine peak efficiency and less than 12% overhead with respect to the fastest failure-free implementation. We predict (and have observed) that, as we increase the processor count, the overhead of the fault tolerance drops significantly.     

Variable temperature characterization of N,N′-Bis(n-pentyl)terrylene-3,4:11,12-tetracarboxylic diimide thin film transistor

Organic thin film transistors (OTFT) based on N,N′-Bis(n-pentyl)terrylene-3,4:11,12-tetracarboxylic diimide (TTCDI-5C) with Al or Au top-contact electrodes were deposited on SiO₂ (200 nm)/p-Si (0 0 1) substrates. Carrier mobility was examined as a function of temperature in the range from 50 to 310 K. Two distinct carrier transfer behaviours were observed: temperature independent behaviour below 150 K and thermally activated behaviour above 150 K. Activation energies presented values of 85–130 meV depending on the metal electrodes (Au, Al), which can be attributed to the carrier traps at the interface and the energy-level offset between the lowest unoccupied molecular orbital (LUMO) and the work functions of the respective metals.     

Electrochemical ozone production: influence of the supporting electrolyte on kinetics and current efficiency

The nature of the electrolyte strongly influences the electrode kinetics of the oxygen evolution reaction (OER) and electrochemical ozone production (EOP) mainly by affecting the degree of coverage by the intermediates of both processes. The anomalous behaviour of the Tafel coefficient, b, as a function of temperature was attributed to surface adsorption of the electrolyte species, and the competition between them, as well as gas bubble adherence. Comparison of the current efficiencies of the EOP, Φ_EOP, determined for different temperatures and supporting electrolyte compositions, showed the presence of fluorinated anions increases Φ_EOP. The influence of the anion nature on Φ_EOP, when analysed in the light of the proposed electrode mechanism, reveals introduction into the electrolyte of anions having a high electronegativity changes the double layer structure resulting in an increase of surface concentration of the active centres leading to EOP. The inhibition of the OER in the high overpotential domain during EOP provoked by fluoro-anion adsorption is supported by the activation energy data. In situ surface characterisation before and after EOP investigation revealed that even under drastic conditions (high current density, low interfacial pH) β-PbO₂ can be considered an inert electrode material.     

Factor impact and indexing in bibliographic databases: comparison of these quality criteria for the assessment of pharmaceutical journals

In spite of limits, the impact factor (IF) of Journal Citation Reports (JCR) of Science Citation Index (SCI) edited by the Institute for Scientific Information (ISI) is the most currently used bibliometric factor by scientists. Otherwise, bibliographic systems select and index scientific journals with their own quality criterion. In order to bring scientists and information professionals some new journal evaluation developments, we studied and compared pharmaceutical journal IF and the number of bibliographic systems in which they were indexed. We firstly have given our definition of pharmaceutical journal and then evaluated these journals by giving one point each time they were indexed in one of the five following bibliographic systems: Index Medicus/Medline, Excerpta Medica/Embase, International Pharmaceutical Abstracts, Chemical Abstracts, Current Contents. We then compared their results with IF. We selected 292 journals: 14.4% scored 5 points, 22.3% scored 4 points, 27.7% scored 3 points, 18.8% scored 2 points, 16.8% scored 1 point. We also showed that the more journals scored highly, the more they had chances of being taken by JCR. We studied the first hundred journals indexed by JCR and having the highly IF: 31, 40, 21, 6 and 2 journals were respectively indexed by 5, 4, 3, 2 and 1 bibliographic systems. We showed that there was a significant difference between the two classifications. So, we can say that people who take IF as the one and only journal quality criterion have in fact a very partial representation of the edition of scientific papers.     

Accelerated pavement testing and modeling of reflective cracking in pavements

In the field of reflective cracking initiation and propagation in pavement structures, an Accelerated Pavement Testing (APT) has been developed. The numerical method is also supported. Numerical results obtained by calculations made with the finite element CESAR-LCPC software are then compared with the experimental data. The reflective cracking APT experience is the first step in the development of a new laboratory equipment to evaluate the design of bituminous layers to repair pavements. The experiment was performed on a 30 m track where eight discontinuities were established by cutting-off the sub-bases in order to ensure a crack development in the bituminous layer. The conditions that promote crack propagation were reproduced by the application of heavy periodic loads using the Fabac ALT-APT test rig. The width of the bituminous layer was decreased to facilitate the observation of the crack propagation, while avoiding creep of the material. The structure has a large number of sensors that measure longitudinal and transverse deformations at the bottom and at the surface of the bituminous layer. The deflections and the displacements are measured at several levels of the structure, as well as the temperature and the lateral edge cracking which is monitored by cracking sensors on both sides of the track. Preliminary results on two joints were used to determine the mechanisms of rupture of the structure. Four more tests with improved sensors have completed the information. Experimental and numerical results are compared in order to validate the analysis of the fatigue process (debonding, damage and cracking) in full scale pavement.     

Dendrite growth directions and morphology in the directional solidification of anisotropic materials

This study has experimentally determined the growth direction and the morphology of dendrites in a thin sample of succinonitrile alloy in configurations where the heat flow direction differs from the preferred crystalline orientations. A large data set has been obtained over a range of growth velocity, dendrite spacing, and misorientation angle between the two directions. Data analysis has provided evidence of an internal symmetry from which the expression of the orientational response of dendrites to the growth conditions has been identified. This has been complemented by the identification of a new dendrite scale, more relevant than the dendrite spacing to the present issue. Altogether, these results provide new insights on the growth direction and the morphology of dendrites that could be applied to more practical configurations.     

Morphological responses and molecular modifications in tomato plants after mechanical stimulation

Study of the growth responses of Lycopersicon esculentum (Mill. cv. VFN8) to mechanical stimulation applied to a single young internode showed a rapid and sharp decrease in stem elongation and an inhibition of elongation of several internodes, indicative of information transmission in the plant. A new tomato cDNA partial clone encoding calmodulin was isolated and used to study the time course of the gene induction in response to the rubbing treatment. Northern blot analysis showed a maximum accumulation of calmodulin mRNA 2 h after mechanical stimulation, not only in the rubbed internode, but also in upper and lower internodes and in young leaves. Treatment of the plant with calcium and EGTA showed the involvement of calcium and, in particular, intracellular calcium in calmodulin gene expression and cellular response.