Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Interprétation des tests sérologiques : ne pas oublier le transfert passif des immunoglobulines ! [Beware of immunoglobulin's passive transfer when interpreting serological analyses!].

National audienceDue to their extended indications, intravenous immunoglobulins (IVIg) are increasingly used in hospital setting. After injection, classical IVIg half-life reaches more than 3weeks. IVIg result from the pooling of many blood donations and contain all natural antibodies usually found in the general population. Administered antibodies are known to interfere with many diagnostic assays, particularly those used for infectious serology. It is not recommended to perform serological determination after IVIg infusion. It is recommended to keep a delay of at least 4months after IVIg infusion before doing any serological assay; failure to do so will result in misinterpretation of biological findings. Interpretation of any serological test after IVIg administration should be particularly cautious

Customized measuring station for Peltier modules

Peltier modules control temperatures in niche products such as wine coolers and camping fridges or are used to precisely temper processes as for example the duplication of DNA sections. Accurate characterization and long term stability of the modules is crucial in order to meet the high reliability requirements especially in critical applications such as in space or medical technology markets. While most of the measurement stations are designed for thermoelectric generators, especially in regard to long term testing, the measurement of peltier modules is rarely described. In this contribution, we show a customized measuring station specifically for the combination of the characterization of peltier modules and their long term stability. With this measurement station, it is possible to determine temperature dependent properties such as the maximum current Imax, the maximum cooling power Image 1, the maximum temperature difference Image 2 and the coefficient of performance (COP) while performing cycling tests in between the characterization measurements. In this setup, both sides consist of water driven heat exchangers with a range of Image 3 to Image 4. The heat flow through the module is measured via two graphite heat flux meters.Thereby, it is possible to completely characterize a peltier module within this measuring system. An error analysis for the measured properties is given as well. In addition to the characterization of the modules, the long-term stability of the modules can be measured not only with static current and temperature but also at cyclical stimulation of temperature or current changes meaning that application-oriented long-term tests are possible

Characterization of open woodwind toneholes by the tube reversed method

Woodwind tonehole’s linear behavior is characterized by two complex quantities: the series and shunt acoustic impedances. A method to determine experimentally these two quantities is presented. It is based on two input impedance measurements. The method can be applied to clarinet-like instruments.The robustness of the method proposed is explored numerically through the simulation of the experiment when considering geometrical and measurement uncertainties. Experimental results confirm the relevance of the method proposed to estimate the shunt impedance. Even the effect of small changes in the hole's geometry, such as those induced by undercutting, are characterized experimentally. The main effect of undercutting is shown to be a decrease of the tonehole’s acoustic mass, in agreement with theoretical considerations based on the shape of the tonehole. Experimental results also reveal that losses in toneholes are significantly higher than those predicted by the theory. Therefore the method is suitable for the experimental determination of the shunt impedance, but it is not convenient for the characterization of the series impedance

Comparison between methods to characterize the acoustical properties of musical toneholes

International audienceIn woodwind instruments, lateral holes or toneholes, are used to reduce the effective length of the instrument in order to increase the number of notes that can be played. Over the time, instrument makers have noticed that details of the tonehole's geometry play a major role in the musical quality of woodwind instruments, a change in geometry impacts parameters such as: tuning, volume, and timbre. From the scientific point of view, it is of interest to link the tonehole's geometry to the acoustical properties of the produced sound. A single tonehole can be represented by a lumped T circuit comprised of a shunt and series impedance. In order to determine the values of these impedances, several methods have been developped, [Keefe 1982, Nederveen 1998, Dubos et al. 1999, Dalmont et al. 2002, Dickens 2007, Lefebvre and Scavone 2012], these include theoretical, experimental, and numerical approaches. In this study a new method is proposed and compared to the method developed by Dalmont et al. (2002). The new approach is based on two measurements of the input impedance instead of the measurement of the input and transfer impedances of the methodology proposed by Dalmont et al. Also the tonehole position does not need to be at the middle of the main tube. Simulations of the experiments of both methologies were performed to compare the effect of the uncertainty over the accuracy of the results. These results can be used for the design, and improvement of woodwind instruments

Flat-Plate PHP with Gravity-Independent Performance and High Maximum Thermal Load

In many energy-related applications, components with high heat loads, such as power electronics, play an important role. Pulsating heat pipes (PHPs) are an effective solution to deal with the increasing heat load of these components. In many real-life applications, the PHP must work against gravity and still be able to operate efficiently. However, the majority of present flat-plate PHP designs do not perform well under this condition. Therefore, this paper presents a flat-plate PHP with a conventional channel design optimized for gravity-independent operation. The PHP was capable of transmitting a heat output of 754 watts in all orientations, while the testing heater in use never exceeded a temperature of 100 °C. No indications of dryout were observed, implying that the maximum thermal load the PHP can handle is even higher. Additionally, three different condenser zone sizes were tested with the PHP. Previously published results indicated that there is a specific range of suitable condenser zone sizes, and performance problems will occur if the condenser zone size falls outside of this range. The findings from this work point in the same direction

Small-Sized Pulsating Heat Pipes/Oscillating Heat Pipes with Low Thermal Resistance and High Heat Transport Capability

Electronics (particularly power electronics) are the core element in many energy-related applications. Due to the increasing power density of electronic parts, the demands on thermal management solutions have risen considerably. As a novel passive and highly efficient cooling technology, pulsating heat pipes (PHPs) can transfer heat away from critical hotspots. In this work, we present two types of small and compact PHPs with footprints of 50 × 100 mm2, thicknesses of 2 and 2.5 mm and with high fluid channel density, optimized for cooling electronic parts with high power densities. The characterization of these PHPs was carried out with a strong relation to practical applications, revealing excellent thermal properties. The thermal resistance was found to be up to 90% lower than that of a comparable solid copper plate. Thus, a hot part with defined heating power would remain at a much lower temperature level and, for the same heater temperature, a much larger heating power could be applied. Moreover, the dependence of PHP operation and thermal properties on water and air cooling, condenser area size and orientation is examined. Under some test configurations, dryout conditions are observed which could be avoided by choosing an appropriate size for the fluid channels, heater and condenser

Recherches et musiques au LMA

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