Green synthesis of vanillin: Pervaporation and dialysis for process intensification in a membrane reactor

In the present work, two different membrane processes (pervaporation and dialysis) are compared in view of their utilization in a membrane reactor, where vanillin, which is probably the most important aroma of the food industry, is synthesized in a green and sustainable way. The utilized precursor (ferulic acid, which is possibly a natural product from agricultural wastes) is partially oxidized (photocatalytically or biologically) and the product is continuously recovered from the reacting solution by the membrane process to avoid its degradation. It is observed that pervaporation is much more selective towards vanillin than dialysis, but the permeate flux of dialysis is much higher. Furthermore, dialysis can work also at lower temperatures and can be used to continuously restore the consumed substrate into the reacting mixture. A mathematical model of the integrated process (reaction combined with membrane separation) reproduces quite satisfactorily the experimental results and can be used for the analysis and the design of the process

Combinatorial optimization based recommender systems.

Recommender systems exploit a set of established user preferences to predict topics or products that a new user might like [2]. Recommender systems have become an important research area in the field of information retrieval. Many approaches have been developed in recent years and the interest is very high. However, despite all the efforts, recommender systems are still in need of further development and more advanced recommendation modelling methods, as these systems must take into account additional requirements on user preferences, such as geographic search and social networking. This fact, in particular, implies that the recommendation must be much more “personalized” than it used to be. In this paper, we describe the recommender system used in the “DisMoiOu”(“TellMeWhere” in French) on-line service (http://dismoiou.fr), which provides the user with advice on places that may be of interest to him/her; the definition of “interest” in this context is personalized taking into account the geographical position of the user (for example when the service is used with portable phones such as the Apple iPhone), his/her past ratings, and the ratings of his/her neighbourhood in a known social network. Using the accepted terminology [6], DisMoiOu is mainly a Collaborative Filtering System (CFS): it employs opinions collected from similar users to suggest likely places. By contrast with existing recommender systems, ours puts together the use of a graph theoretical model [4] and that of combinatorial optimization methods [1]. Broadly speaking, we encode known relations between users and places and users and other users by means of weighted graphs. We then define essential components of the system by means of combinatorial optimization problems on a reformulation of these graphs, which are finally used to derive a ranking on the recommendations associated to pairs (user,place). Preliminary computational results on the three classical evaluation parameters for recommender systems (accuracy, recall, precision [3]) show that our system performs well with respect to accuracy and recall, but precision results need to be improved

Sharing of hand kinematic synergies across subjects in daily living activities

The motor system is hypothesised to use kinematic synergies to simplify hand control. Recent studies suggest that there is a large set of synergies, sparse in degrees of freedom, shared across subjects, so that each subject performs each action with a sparse combination of synergies. Identifying how synergies are shared across subjects can help in prostheses design, in clinical decision-making or in rehabilitation. Subject-specific synergies of healthy subjects performing a wide number of representative daily living activities were obtained through principal component analysis. To make synergies comparable between subjects and tasks, the hand kinematics data were scaled using normative range of motion data. To obtain synergies sparse in degrees of freedom a rotation method that maximizes the sum of the variances of the squared loadings was applied. Resulting synergies were clustered and each cluster was characterized by a core synergy and different indexes (prevalence, relevance for function and within-cluster synergy similarity), substantiating the sparsity of synergies. The first two core synergies represent finger flexion and were present in all subjects. The remaining core synergies represent coordination of the thumb joints, thumb-index joints, palmar arching or fingers adduction, and were employed by subjects in different combinations, thus revealing different subject-specific strategies

Application of Neurochemical Markers for Assessing Health Effects after Developmental Methylmercury and PCB Coexposure

Cholinergic muscarinic receptors (MRs) and monoamine oxidase activity (MAO-B), expressed both in brain and blood cells, were investigated in animals and exposed subjects to assess (i) MeHg (0.5–1 mg/kg/day GD7-PD7) and/or PCB153 (20 mg/kg/day GD10–GD16) effects on cerebellar MAO-B and MRs, and lymphocyte MRs, in dams and offspring 21 days postpartum; (ii) MAO-B in platelets and MRs in lymphocytes of a Faroese 7-year-old children cohort, prenatally exposed to MeHg/PCBs. Animal Data. MAO-B was altered in male cerebellum by MeHg, PCB153, and their combination (35%, 45%, and 25% decrease, resp.). Cerebellar MRs were enhanced by MeHg alone in dams (87%) and male pups (27%). PCB153 alone and in mixture did not modify cerebellar MRs. Similarly to brain, lymphocyte MRs were enhanced in both dams and offspring by MeHg alone. All changes were caused by 1 MeHg mg/kg/day, the lower dose was ineffective. Human Data. Both biomarkers showed homogeneous distributions within the cohort (MRs, range 0.1–36.78 fmol/million cells; MAO-B, 0.95–14.95 nmol/mg protein/h). No correlation was found between the two biomarkers and neurotoxicant concentrations in blood (pre- and postnatally)

Contact-Induced Emigration of Potato Leafhopper (Homoptera: Cicadellidae) from Alfalfa-Forage Grass Mixtures

Studies were conducted to evaluate the mechanisms leading to increased potato leafhopper, Empoasca fabae (Harris), emigration from alfalfa-forage grass mixtures. A laboratory behavioral bioassay was used to measure daily emigration rates of adult leafhoppers from alfalfa, Medicago sativa L.; smooth bromegrass, Bromus inermis Leyss.; orchardgrass, Dactylis glomerata L.; and timothy, Phleum pratense L., alone and in 1:1 mixtures of each grass with alfalfa. Emigration was ≍9-fold greater from pure bromegrass and orchardgrass treatments versus alfalfa alone, and ≍5-fold greater than from mixtures of alfalfa and each grass species. In a 2nd experiment, alfalfa and forage grasses were separated by a barrier permeable to plant volatiles. Only 31% of the potato leafhoppers placed on alfalfa adjacent to either alfalfa or grass emigrated. However, when introduced to the side containing a forage grass, <85% of the leafhoppers emigrated, regardless of adjacent plant. Thus, stimuli obtained from physical contact with the grass versus grass volatiles alone were required to elicit emigration. Observations of potato leafhoppers on single plants of smooth bromegrass, orchardgrass, and alfalfa revealed that individuals fed on all 3 species; however, the frequency and duration of probing differed as did mean residency time (10.7 h alfalfa, 7.5 h bromegrass, 5.9 h orchardgrass). These experiments suggested that physical contact is necessary to elicit emigration from grasses. By increasing emigration, alfalfa-forage grass mixtures may reduce potato leafhopper damage to alfalfa. Additionally, intercropping with forage grasses may lower the number of feeding bouts on alfalfa and reduce subsequent hopperbur

Evaluating a Kinematic Data Glove with Pressure Sensors to Automatically Differentiate Free Motion from Product Manipulation

When studying hand kinematics, it is key to differentiate between free motion and manipulation. This differentiation can be achieved using pressure sensors or through visual analysis in the absence of sensors. Certain data gloves, such as the CyberGlove II, allow recording hand kinematics with good accuracy when properly calibrated. Other gloves, such as the Virtual Motion Glove 30 (VMG30), are also equipped with pressure sensors to detect object contact. The aim of this study is to perform a technical validation to evaluate the feasibility of using virtual reality gloves with pressure sensors such as the VMG30 for hand kinematics characterization during product manipulation, testing its accuracy for motion recording when compared with CyberGlove as well as its ability to differentiate between free motion and manipulation using its pressure sensors in comparison to visual analysis. Firstly, both data gloves were calibrated using a specific protocol developed by the research group. Then, the active ranges of motion of 16 hand joints angles were recorded in three participants using both gloves and compared using repeated measures ANOVAs. The detection capability of pressure sensors was compared to visual analysis in two participants while performing six tasks involving product manipulation. The results revealed that kinematic data recordings from the VMG30 were less accurate than those from the CyberGlove. Furthermore, the pressure sensors did not provide additional precision with respect to the visual analysis technique. In fact, several pressure sensors were rarely activated, and the distribution of pressure sensors within the glove was questioned. Current available gloves such as the VMG30 would require design improvements to fit the requirements for kinematics characterization during product manipulation. The pressure sensors should have higher sensitivity, the pressure sensor’s location should comprise the palm, glove fit should be improved, and its overall stiffness should be reduced

Kinetic and kinematic analysis of midfoot joints of healthy subjects during walking: Clinical considerations

Introducción: No existe todavía suficiente evidencia en estudios clínicos respecto al comportamiento del mediopié en situaciones dinámicas como la marcha o la carrera. El presente estudio pretende analizar el comportamiento mecánico de las articulaciones del mediopié mediante un modelo multisegmental del pie, con especial atención a los momentos articulares y sus repercusiones clínicas. Sujetos y métodos: Se realizó un estudio computarizado de la marcha sobre 30 sujetos adultos sanos (27,13 ± 3,82 a˜nos) con un índice de postura del pie (FPI) neutro (entre 0 y +5). Se estimaron los ángulos y momentos articulares externos en 3 dimensiones mediante un modelo que considera 3 segmentos (antepié, retropié y hallux) y se analizó la evolución de dichas variables durante la marcha sobre la articulación del mediopié (articulación que conecta antepié y retropié) del pie derecho de todos los sujetos. Resultados: Los mayores momentos articulares observados se dieron en el plano sagital en flexión dorsal produciendo una tendencia al colapso o aplanamiento del pie durante la fase de apoyo de la marcha. Los momentos articulares registrados en los planos frontal y transverso fueron de una magnitud mucho menor que la observada en el plano sagital y de menor relevancia clínica. Discusión: El presente estudio aporta datos sobre el comportamiento mecánico de las articulaciones del mediopié en una muestra de 30 sujetos sanos con un FPI neutro. Este estudio muestra la importancia del estrés tensional al que se encuentran sometidas las estructuras blandas plantares durante la fase de apoyo de la marcha.Introduction: There is not enough evidence in form of clinical studies regarding the behavior of the midfoot joints in dynamic situations such us walking or running. The present work aims to study the mechanical behavior of midfoot joints with a multisegmented foot model with special interest in joint moments and their clinical significance. Subjects and methods: A computerized 3-dimensional gait study was performed on 30 healthy male adult subjects (27.13 ± 3.82 years) with a neutral Foot Posture Index (FPI) (from 0 to +5) during walking. Joint angle and external moments were estimated with a multisegment foot model that considers three separate segments (forefoot, rearfoot and hallux) and graphs and values of midfoot joint (joint connecting forefoot to rearfoot) were analyzed for the right foot of all participants. Results: Highest external moments were observed in the sagittal plane in dorsiflexion direction which tend to collapse the longitudinal arch during the stance phase. Moments registered in frontal and transverse planes were much lower than those observed in the sagittal plane and seemed to have lower clinical relevance. Discussion: The present study provides data about the mechanical behavior of midfoot joints in a healthy adult population with a neutral FPI. This work shows that plantar soft tissues are subjected to important tensional stress during the stance phase of walking