The fundamental and medical impacts of recent progress in research on hereditary hearing loss

What would define real progress in the field of deafness research in fundamental and medical terms? In fundamental terms, progress would be measured by an improvement in our knowledge of the development and physiology of the ear. In medical terms, progress would lead to the division of the broad category of hearing defects into distinct clinical entities or subclasses, the collection of epidemiological data, the creation of molecular diagnostic tests, the improvement of genetic counselling services and the development of new therapeutics. In this review, we will introduce some general considerations on hereditary hearing loss and on the structure and function of the ear, present the rapidly emerging data on the molecular basis of syndromic and non-syndromic forms of hearing loss and comment on relevant recent progress in this field of research. Generally speaking, the isolation of genes underlying hereditary hearing loss has, as yet, had little impact on our understanding of the biology of the ear, whereas it has made major contributions to the medical field, in particular due to the recognition of two genes, Cx26 and mitochondrial 12S rRNA , as frequently underlying cases of non-syndromic hearing impairment.     

RACFP: a training tool to work with floating-point representation, algorithms, and circuits in undergraduate courses

The design of pedagogical tools to train students is an interesting challenge for academic instructors in any educational area. Some approaches have appeared focusing on computer arithmetic, both integer and floating point. Floating-point arithmetic involves much more complexity; nevertheless, little time is usually devoted to this topic in computer engineering undergraduate courses. In this paper, RACFP is proposed as a pedagogical tool to work with floating-point in undergraduate courses. The tool has been designed with three abstraction levels according to the following learning outcomes: representation, arithmetic operation algorithms, and manufactured hardware circuits. The abstraction levels work independently, allowing for the use of RAC/sub FP/ in other courses, such as discrete mathematics or numerical methods, in which floating representation and related issues are also learning topics. RACFP design pursues two main goals: to minimize the complexity of the learning process and to encourage students when working with floating point. The first goal is achieved as a result of the multilevel design of the tool, while the second goal is achieved as RAC/sub FP/ shows how manufactured hardware implements generic algorithms.     

Infrared spectroscopy of NH4-bearing and saturated clay minerals: A review of the study of layer charge

Infrared (IR) spectroscopy study of the layer charge of clay minerals demonstrates that the υ₄ NH₄⁺ band, assigned to the deformation vibrations of the NH₄⁺ ion can be used to evaluate the charge characteristics of NH₄⁺-bearing clay minerals. Total accessible charge, equivalent to cation exchange capacity (CEC), as well as tetrahedral and octahedral charge distribution in both dioctahedral and trioctahedral smectites are determined by quantifying the υ₄ NH₄⁺ band before and after lithium treatment. When using the KBr pressed pellets technique, the position and the shape of the υ₄ NH₄⁺ bands can distinguish exchangeable and fixed NH₄⁺ in clay minerals.     

Analysis of microporosity and setting of reactive powder concrete by proton nuclear relaxation

The proton spin-lattice relaxation measured at several frequencies leads to a resolved distribution of four Tli for reactive powder concrete (RPC). The typical Tli frequency dependences are quantitatively interpreted by a biphasic fast exchange model and a proton nuclear relaxation of hydrated paramagnetic ions at the surface of the pores. This leads to an estimation of the pore sizes. We present the first application of this nuclear relaxation method to follow in situ the kinetics of the hydration and setting of such material.     

Role of mouse cryptochrome blue-light photoreceptor in circadian photoresponses

Cryptochromes are photoactive pigments in the eye that have been proposed to function as circadian photopigments. Mice lacking the cryptochrome 2 blue-light photoreceptor gene (mCry2) were tested for circadian clock-related functions. The mutant mice had a lower sensitivity to acute light induction of mPer1 in the suprachiasmatic nucleus (SCN) but exhibited normal circadian oscillations of mPer1 and mCry1 messenger RNA in the SCN. Behaviorally, the mutants had an intrinsic circadian period about 1 hour longer than normal and exhibited high-amplitude phase shifts in response to light pulses administered at circadian time 17. These data are consistent with the hypothesis that CRY2 protein modulates circadian responses in mice and suggest that cryptochromes have a role in circadian photoreception in mammals.     

Semantic sampling of existing databases through informative Armstrong databases

Functional dependencies (FDs) and inclusion dependencies (INDs) convey most of data semantics in relational databases and are very useful in practice since they generalize keys and foreign keys. Nevertheless, FDs and INDs are often not available, obsolete or lost in real-life databases. Several algorithms have been proposed for mining these dependencies, but the output is always in the same format: a simple list of dependencies, hard to understand for the user. In this paper, we define informative Armstrong databases (IADBs) from databases as being small subsets of an existing database, satisfying exactly the same FDs and INDs. They are an extension of the classical notion of Armstrong databases, but more suitable for the understanding of dependencies, since tuples are real-world tuples. The main result of this paper is to bound the size of an IADB in the case of non-circular INDs. A constructive proof of this result is given, from which an algorithm has been devised. An implementation and experiments against a real-life database were performed; the obtained database contains 0.6% of the initial database tuples only. More importantly, such semantic sampling of databases appear to be a key feature for the understanding of existing databases at the logical level.     

Polymer nanocomposites for microactuation and magneto-electric transduction

In the last decade, electroactive polymers have attracted much attention especially because of their very actuating capabilities. Large strain is experimentally observed, but under quite high electrical field, which can be a severe drawback for actuating applications. First part of the present paper is concerned with the reduction of applied field onto electroactive polymer films to get a given strain level. Polyurethane (PU) films filled with carbon black (CB) nanoparticles exhibit relatively high strain level under a field of only 12.5 kV/mm. The simple easy-tomake method solution cast method was applied. Even though the generated stress level is still quite low, the present work shows high strain level under quite low field appliance by easy manufacturing, lightweight, and flexible polymer film. Besides, another interest of the present paper is in magneto-elasto-electric effect of a polymer film filled with some magnetic nano particles. Films filled with nonpiezoelectric but with magnetite particles has still short history. With the use of magneto materials, a large magnetic DC bias field is generally required, and it causes big problem on application. The films filled with some magnetite nanoparticles (Fe3O4 and Nickel) are fabricated then examined. It is clearly demonstrated that our films do not require any DC bias. Although linear polarization value is relatively small, the first step of the studies on magnetite nano-filled film is presented.     

Boundary control for an industrial under-actuated tubular chemical reactor

Several control strategies are presented and studied for an industrial under-actuated tubular chemical reactor. This work presents a case-study of the performance of a decentralized versus centralized control strategy. The tubular reactor under consideration is characterized by nonlinear kinetic laws, and it has some structural constraints on the location of the heat exchangers and of the sensors. For this system, a set of PI controllers is considered and a multivariable LQR controller is constructed to optimally choose the gains. The performance of these control strategies is studied. Finally, a direct numerical treatment of optimal control of the partial differential equations is presented. Industrial results are given for the linear controllers. Simulations emphasize the possible relevance of a direct numerical treatment of the nonlinear partial differential equations.