Adapting groupware systems to changes in the collaborator’s context of use

Owing to the dynamic nature of collaborative environments, the software intended to support collaborative work should adapt itself to the different situations that may occur. This requirement is related to the concept of “context of use”, which has been considered as an important aspect in the design of interactive systems. Nevertheless, two main problems about this concept have been identified by current research in context-aware computing: (1) most of the studies have mainly focused on the context of a single user, so the context of multiple users involved in a common endeavor remains little explored, and (2) adaptability in context-aware systems generally takes into account a reduced number of contextual variables (mainly the user’s location and platform). In this paper, we firstly re-conceptualize the notion of “context of use”, in order to consider the main characteristics of collaborative environments. Based on this new notion, we then design and implement a framework that allows application developers to specify the adaptability of groupware systems in terms of the state of activities, roles, collaborators’ location, available resources, and other typical variables of working groups. This framework has been generalized from scenarios that highlight dynamic situations presented in real collaborative settings. Finally, we validate our proposal by a set of applications that are able to adapt their user interface and functionality, when significant changes are produced in the environment, the working group, and/or the used devices.     

Crystallization and melting properties of extra virgin olive oil studied by synchrotron XRD and DSC

Crystallization and melting properties of triacylglycerols in extra virgin olive oil were studied by using synchrotron X‐ray diffraction (XRD) and differential scanning calorimetry (DSC). The phase transitions were monitored by cooling and heating the samples at 2°C/min from 60 to ?60°C and vice versa. Upon cooling, a first DSC endothermic peak was recorded at ?9.6°C followed by one at ?33.5°C. These thermal events were associated to the formation of two different structures: a triple‐chain length (3L) having a c parameter of about 58.38 Å and a quadruple chain length structure (4L) with a c parameter of about 89.99 Å, respectively. Both structures evidenced a cell packing arrangement ascribable to a β′ form. During heating, part of the metastable β′ crystals rearranged into the more thermodynamically stable β form. Then, upon further heating, the sequential melting of the two crystal structures was observed. The melting was completed at 10.7°C. Beside this interpretation of XRD data, a model considering a cell with a c parameter of about 170 Å and a hexagonal crystal system was proposed. Even if more research is needed to validate this approach, it allowed all XRD events recorded during the experiments to be described. See commentary by Chiavaro [p. 267–269], http://dx.doi.org/10.1002/ejlt.201200415     

Le codeur mpeg-2 AAC expliqué aux traiteurs de signaux

The MPEG- 2 Advanced Audio Coder is the latest issue of the MPEG audio encoders/decoders family, whose most popular version is known as MP3. It gathers many of the latest highly efficient sound compression techniques in a quite classically structured coder. The main part is based on a Discrete Cosine Transform with variable resolution. The output from this filterbank is compressed by the combination of an adaptive bit allocation module, according to frequency subbands, and a set of noiseless Huffman codebooks. Bit allocation is controlled by a psychoa-coustic model which determines an audibility threshold for signal distortion in the frequency domain. This article intends to explain the ISO standard without replacing it, and also to be a general introduction to perceptual audio coding.     

High-Stable Mesoporous Ni-Ce/Clay Catalysts for Syngas Production

Abstract  

A mesoporous-type catalytic support was synthesized through the modification of a smectite with polyvinyl alcohol (PVA) and microwaves. Texture and micro-morphology of the support was determined. Several techniques were employed in order to describe the chemical environment of active species on the surface. Ni⁰ particle sizes were dependent on the structural site of reducible species. High stable Ni-Ce catalysts (calcined at 800 °C) were evaluated in the CO₂ reforming of methane reaction at 700 °C (WHSV = 96 L g⁻¹ h⁻¹, without dilution gas and pre-reduction). The catalysts have presented CH₄ conversions between 40 and 65%, CO₂ conversion between 35 and 65% and H₂/CO ratios between 0.2 and 0.4.     

Therapies Targeted at Non-Coding RNAs in Prevention and Limitation of Myocardial Infarction and Subsequent Cardiac Remodeling—Current Experience and Perspectives

Myocardial infarction is one of the major causes of mortality worldwide and is a main cause of heart failure. This disease appears as a final point of atherosclerotic plaque progression, destabilization, and rupture. As a consequence of cardiomyocytes death during the infarction, the heart undergoes unfavorable cardiac remodeling, which results in its failure. Therefore, therapies aimed to limit the processes of atherosclerotic plaque progression, cardiac damage during the infarction, and subsequent remodeling are urgently warranted. A hopeful therapeutic option for the future medicine is targeting and regulating non-coding RNA (ncRNA), like microRNA, circular RNA (circRNA), or long non-coding RNA (lncRNA). In this review, the approaches targeted at ncRNAs participating in the aforementioned pathophysiological processes involved in myocardial infarction and their outcomes in preclinical studies have been concisely presented.     

Hydrogen separation and stability study of ceramic membranes based on the system Nd5LnWO12

This contribution presents the preparation, permeation and stability study of mixed protonic-electronic conducting membranes based on the system Nd₅LnWO₁₂. The tungstates Ln₆WO₁₂ are proton conducting crystalline materials, which show sufficient protonic and electronic mixed conductivity and stability in moist CO₂ environments to consider them as potential candidates for the separation of hydrogen at high temperatures. Hydrogen separation properties of A-substoichiometric Nd₆WO₁₂ and Nd₅LaWO₁₂ were systematically analyzed, i.e. the influence of the H₂ concentration in feed stream, humidification degree and operating temperature on the hydrogen separation was studied. Finally, the stability of these materials at different temperatures and CO₂-rich and sulfur-containing environments was evaluated.