A direct-conversion receiver for the 3G WCDMA standard

A highly integrated direct-conversion receiver that satisfies requirements of the third-generation wide-band code-division multiple-access mobile phone standard is described. The receiver integrated circuit includes the front-end low-noise amplifier, downconversion mixers, baseband variable-gain amplifiers, channel-select filters, and the frequency synthesizer. External components are limited to matching elements required for the low-noise amplifier and the mixers and two passive band-select filters. The receiver is implemented in a SiGe BiCMOS process and consumes a total current of 46 mA from a 2.7-V supply.     

Design and characteristics of high pulse repetition rate and highaverage power excimer laser systems

The authors describe the design and the performance characteristics of an X-ray preionized discharge pumped XeCl laser system operated at very high repetition rate frequency and high average power (200 W). The laser system is mainly composed of a fast flow subsonic closed cycle wind tunnel, a laser head, a high average power electrical excitation system, and an X-ray preionization source. The laser head design and the damping of acoustic waves induced by fast electrical energy deposition of 50 J/L bar allows this device to be operated at repetition rate frequencies of up to ≈1700 Hz     

Learning a new bimanual coordination pattern: Reciprocal influences of intrinsic and to-be-learned patterns.

Examined the following questions: (1) How do previously learned coordination patterns affect new learning (Exp 1)? and (2) How does new learning affect the performance of intrinsic coordination patterns (Exp 2)? In Exp 1, 12 20–24 yr olds practiced either a 45° or a 135° relative phase pattern for 4 days; in Exp 2, 7 21–24 yr olds practiced a 90° relative phase pattern over 6 days. Retention tests were conducted 4 wks after the last practice session in both experiments. Performance on both the in-phase (0°) and anti-phase (180°) patterns was also measured on each day. Results reveal that reciprocal effects between the intrinsic patterns and the new pattern were only temporary, and did not affect learning in any permanent way. Learning a new pattern was not differentially affected by its relation to an intrinsic pattern. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Quantitative analysis of some mechanisms affecting the yield of oxidative phosphorylation: dependence upon both fluxes and forces

The purpose of this work was to show how the quantitative definition of the different parameters involved in mitochondrial oxidative phosphorylation makes it possible to characterize the mechanisms by which the yield of ATP synthesis is affected. Three different factors have to be considered: (i) the size of the different forces involved (free energy of redox reactions and ATP synthesis, proton electrochemical difference); (ii) the physical properties of the inner mitochondrial membrane in terms of leaks (H+ and cations); and finally (iii) the properties of the different proton pumps involved in this system (kinetic properties, regulation, modification of intrinsic stoichiometry). The data presented different situations where one or more of these parameters are affected, leading to a different yield of oxidative phosphorylation. (1) By manipulating the actual flux through each of the respiratory chain units at constant protonmotive force in yeast mitochondria, we show that the ATP/O ratio decreases when the flux increases. Moreover, the highest efficiency was obtained when the respiratory rate was low and almost entirely controlled by the electron supply. (2) By using almitrine in different kinds of mitochondria, we show that this drug leads to a decrease in ATP synthesis efficiency by increasing the H+/ATP stoichiometry ofATP synthase (Rigoulet M et al. Biochim Biophys Acta 1018: 91-97, 1990). Since this enzyme is reversible, it was possible to test the effect of this drug on the reverse reaction of the enzyme i.e. extrusion of protons catalyzed by ATP hydrolysis. Hence, we are able to prove that, in this case, the decrease in efficiency of oxidative phosphorylation is due to a change in the mechanistic stoichiometry of this proton pump. To our knowledge, this is the first example of a modification in oxidative phosphorylation yield by a change in mechanistic stoichiometry of one of the proton pumps involved. (3) In a model of polyunsaturated fatty acid deficiency in rat, it was found that non-ohmic proton leak was increased, while ohmic leak was unchanged. Moreover, an increase in redox slipping was also involved, leading to a complex picture. However, the respective role of these two mechanisms may be deduced from their intrinsic properties. For each steady state condition, the quantitative effect of these two mechanisms in the decrease of oxidative phosphorylation efficiency depends on the values of different fluxes or forces involved. (4) Finally the comparison of the thermokinetic data in view of the three dimensional-structure of some pumps (X-ray diffraction) also gives some information concerning the putative mechanism of coupling (i.e. redox loop or proton pump) and their kinetic control versus regulation of mitochondrial oxidative phosphorylation.     

Scenario recognition for temporal reasoning in medical domains

The recognition of high level clinical scenes is fundamental in patient monitoring. In this paper, we propose a technique for recognizing a session, i.e. the clinical process evolution, by comparison against a predetermined set of scenarios, i.e. the possible behaviors for this process. We use temporal constraint networks to represent both scenario and session. Specific operations on networks are then applied to perform the recognition task. An index of temporal proximity is introduced to quantify the degree of matching between two temporal networks in order to select the best scenario fitting a session. We explore the application of our technique, implemented in the Déjà Vu system, to the recognition of typical medical scenarios with both precise and imprecise temporal information.     

Analysis of diffraction gratings by using an edge element method

Typically the grating problem is formulated for TE and TM polarizations by using, respectively, the electric and magnetic fields aligned with the grating wall and perpendicular to the plane of incidence, and this leads to a one-field-component problem. For some grating profiles such as metallic gratings with a triangular profile, the prediction of TM polarization by using a standard finite-element method experiences a slower convergence rate, and this reduces the accuracy of the computed results and also introduces a numerical polarization effect. This discrepancy cannot be seen as a simple numerical issue, since it has been observed for different types of numerical methods based on the classical formulation. Hence an alternative formulation is proposed, where the grating problem is modeled by taking the electric field as unknown for TM polarization. The application of this idea to both TE and TM polarizations leads to a two-field-component problem. The purpose of the paper is to propose an edge finite-element method to solve this wave problem. A comparison of the results of the proposed formulation and the classical formulation shows improvement and robustness in the new approach.     

Functional analysis of depressive states: integration of cognitive and behavioral contributions (author's transl)

The article provides a review of the main contributions both of behaviorally--and cognitively--oriented litterature on depressive states and depressive behaviors. These various data are organised so as to form into a tool for the functional analysis of depression: symptoms--structures--releasing factors--mechanisms--maintaining and aggravating factors. Synthetic tables at the end of the article constitute a first attempt at a clinical report allowing the pratician to evaluate the contributions--as well as the limits--of a behavioral approach of the depression phenomenom.     

Resting energy expenditure and food-induced thermogenesis in obese children

Nineteen overweight girls 14.54 +/- 0.38 years of age were studied. Results were compared with those obtained in eight age-matched (14.07 +/- 0.51 years) and sex-matched normal weight controls. Energy expenditure (EE) was determined using open-circuit indirect calorimetry at rest, both after a 12-h fast and after an oral sucrose load of 3 g/kg ideal body weight. Food-induced thermogenesis (FIT) was evaluated by computing the area under the curve of the EE response above resting energy expenditure (REE) during the first 3 h after the sucrose load, REE (kcal/day) was higher in the overweight patients (1,818 +/- 46 vs. 1,527 +/- 67; p = 0.002); REE standardized by fat-free mass (FFM) (kcal/kg FFM/day) was lower in obese children than in controls (35.2 +/- 1.0 vs. 44.9 +/- 1.9; p = 0.0001). A linear correlation between REE and FFM was evidenced in both controls and overweight subjects (r = 0.78 and 0.68, respectively; p = 0.05 and p < 0.001, respectively). Actual REE in the obese children was significantly lower than the value predicted by applying the regression equation of REE on FFM in controls to the actual FFM in obese children (paired t test; p = 0.003). FIT was identical in overweight and normal weight subjects, regardless of whether it was expressed in absolute value, as the percentage calorie intake, or standardized by FFM.(ABSTRACT TRUNCATED AT 250 WORDS)