Selection of native Tunisian microalgae for simultaneous wastewater treatment and biofuel production

This paper focuses on the selection of native microalgae strains suitable for wastewater treatment and biofuel production. Four Chlorophyceae strains were isolated from North-eastern Tunisia. Their performances were compared in continuous mode at a 0.3 1/day dilution rate. The biomass productivity and nutrient removal capacity of each microalgae strain were studied. The most efficient strain was identified as Scenedesmus sp. and experiments at different dilution rates from 0.2 to 0.8 1/day were carried out. Maximal biomass productivity of 0.92 g/L·day was obtained at 0.6 1/day. The removal of chemical oxygen demand (COD), ammonium and phosphorus was in the range of 92-94%, 61-99% and 93-99%, respectively. Carbohydrates were the major biomass fraction followed by lipids and then proteins. The saponifiable fatty acid content was in the 4.9-13.2% dry biomass range, with more than 50% of total fatty acids being composed of saturated and monosaturated fatty acids

Detecting optic disc on Asians by multiscale Gaussian filtering

2012-2013 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

A serious games platform for cognitive rehabilitation with preliminary evaluation

In recent years Serious Games have evolved substantially, solving problems in diverse areas. In particular, in Cognitive Rehabilitation, Serious Games assume a relevant role. Traditional cognitive therapies are often considered repetitive and discouraging for patients and Serious Games can be used to create more dynamic rehabilitation processes, holding patients' attention throughout the process and motivating them during their road to recovery. This paper reviews Serious Games and user interfaces in rehabilitation area and details a Serious Games platform for Cognitive Rehabilitation that includes a set of features such as: natural and multimodal user interfaces and social features (competition, collaboration, and handicapping) which can contribute to augment the motivation of patients during the rehabilitation process. The web platform was tested with healthy subjects. Results of this preliminary evaluation show the motivation and the interest of the participants by playing the games.- This work has been supported by FCT - Fundacao para a Ciencia e Tecnologia in the scope of the projects: PEst-UID/CEC/00319/2015 and PEst-UID/CEC/00027/2015. The authors would like to thank also all the volunteers that participated in the study

Application of Surface wave methods for seismic site characterization

Surface-wave dispersion analysis is widely used in geophysics to infer a shear wave velocity model of the subsoil for a wide variety of applications. A shear-wave velocity model is obtained from the solution of an inverse problem based on the surface wave dispersive propagation in vertically heterogeneous media. The analysis can be based either on active source measurements or on seismic noise recordings. This paper discusses the most typical choices for collection and interpretation of experimental data, providing a state of the art on the different steps involved in surface wave surveys. In particular, the different strategies for processing experimental data and to solve the inverse problem are presented, along with their advantages and disadvantages. Also, some issues related to the characteristics of passive surface wave data and their use in H/V spectral ratio technique are discussed as additional information to be used independently or in conjunction with dispersion analysis. Finally, some recommendations for the use of surface wave methods are presented, while also outlining future trends in the research of this topic

STUDY OF THE SPACE CHARGE RELAXATION IN POLY ETHER ETHER KETONE (PEEK)

Abstract The relaxation of space charge is studied by the dielectric modulus formalism in poly(ether ether ketone) (PEEK). The obtained data suggest a prevailing ohmic conduction in one specimen and interfacial polarization effect, known as the Maxwell-Wagner-Sillars polarization. The interfacial relaxation taking place at the interface between the crystalline inclusions and the amorphous matrix. It's attributed to the trapping of ionic charges at the interface between crystalline lamellae and the amorphous matrix. The conductivity must be attributed to the increasing mobility of the carriers

Microaneurysm (MA) Detection via Sparse Representation Classifier with MA and Non-MA Dictionary Learning

Diabetic retinopathy (DR) is a common complication of diabetes that damages the retina and leads to sight loss if treated late. In its earliest stage, DR can be diagnosed by micro aneurysm (MA). Although some algorithms have been developed, the accurate detection of MA in color retinal images is still a challenging problem. In this paper we propose a new method to detect MA based on Sparse Representation Classifier (SRC). We first roughly locate MA candidates by using multi-scale Gaussian correlation filtering, and then classify these candidates with SRC. Particularly, two dictionaries, one for MA and one for non-MA, are learned from example MA and non-MA structures, and are used in the SRC process. Experimental results on the ROC database show that the proposed method can well distinguish MA from non-MA objects.Department of ComputingRefereed conference pape

Evaluation of native microalgae from Tunisia using the pulse-amplitude-modulation measurement of chlorophyll fluorescence and a performance study in semi-continuous mode for biofuel production

Background: Microalgae are attracting much attention as a promising feedstock for renewable energy production, while simultaneously providing environmental benefits. So far, comparison studies for microalgae selection for this purpose were mainly based on data obtained from batch cultures, where the lipid content and the growth rate were the main selection parameters. The present study evaluates the performance of native microalgae strains in semi-continuous mode, considering the suitability of the algal-derived fatty acid composition and the saponifiable lipid productivity as selection criteria for microalgal fuel production. Evaluation of the photosynthetic performance and the robustness of the selected strain under outdoor conditions was conducted to assess its capability to grow and tolerate harsh environmental growth conditions. Results: In this study, five native microalgae strains from Tunisia (one freshwater and four marine strains) were isolated and evaluated as potential raw material to produce biofuel. Firstly, molecular identification of the strains was performed. Then, experiments in semi-continuous mode at different dilution rates were carried out. The local microalgae strains were characterized in terms of biomass and lipid productivity, in addition to protein content, and fatty acid profile, content and productivity. The marine strain Chlorella sp. showed, at 0.20 1/day dilution rate, lipid and biomass productivities of 35.10 mg/L day and 0.2 g/L day, respectively. Moreover, data from chlorophyll fluorescence measurements demonstrated the robustness of this strain as it tolerated extreme outdoor conditions including high (38 ° C) and low (10 ° C) temperature, and high irradiance (1600 µmol/m2 s). Conclusions: Selection of native microalgae allows identifying potential strains suitable for use in the production of biofuels. The selected strain Chlorella sp. demonstrated adequate performance to be scaled up to outdoor conditions. Although experiments were performed at laboratory conditions, the methodology used in this paper allows a robust evaluation of microalgae strains for potential market applications.This study was supported by the Marine Microalgae Biotechnology Group at the University of Almer'a (BIO 173) and the Campus de Excelencia Internacional Agroalimentario (ceiA3) within the joint framework of supervised theses between the University of Almeria, Spain and the University of Sfax, Tunisia.Scopu

An Ontological Approach to Inform HMI Designs for Minimizing Driver Distractions with ADAS

ADAS (Advanced Driver Assistance Systems) are in-vehicle systems designed to enhance driving safety and efficiency as well as comfort for drivers in the driving process. Recent studies have noticed that when Human Machine Interface (HMI) is not designed properly, an ADAS can cause distraction which would affect its usage and even lead to safety issues. Current understanding of these issues is limited to the context-dependent nature of such systems. This paper reports the development of a holistic conceptualisation of how drivers interact with ADAS and how such interaction could lead to potential distraction. This is done taking an ontological approach to contextualise the potential distraction, driving tasks and user interactions centred on the use of ADAS. Example scenarios are also given to demonstrate how the developed ontology can be used to deduce rules for identifying distraction from ADAS and informing future designs

Cross-Reactive Human IgM-Derived Monoclonal Antibodies that Bind to HIV-1 Envelope Glycoproteins

Elicitation of antibodies with potent and broad neutralizing activity against HIV by immunization remains a challenge. Several monoclonal antibodies (mAbs) isolated from humans with HIV-1 infection exhibit such activity but vaccine immunogens based on structures containing their epitopes have not been successful for their elicitation. All known broadly neutralizing mAbs (bnmAbs) are immunoglobulin (Ig) Gs (IgGs) and highly somatically hypermutated which could impede their elicitation. Ig Ms (IgMs) are on average significantly less divergent from germline antibodies and are relevant for the development of vaccine immunogens but are underexplored compared to IgGs. Here we describe the identification and characterization of several human IgM-derived mAbs against HIV-1 which were selected from a large phage-displayed naive human antibody library constructed from blood, lymph nodes and spleens of 59 healthy donors. These antibodies bound with high affinity to recombinant envelope glycoproteins (gp140s, Envs) of HIV-1 isolates from different clades. They enhanced or did not neutralize infection by some of the HIV-1 primary isolates using CCR5 as a coreceptor but neutralized all CXCR4 isolates tested although weakly. One of these antibodies with relatively low degree of somatic hypermutation was more extensively characterized. It bound to a highly conserved region partially overlapping with the coreceptor binding site and close to but not overlapping with the CD4 binding site. These results suggest the existence of conserved structures that could direct the immune response to non-neutralizing or even enhancing antibodies which may represent a strategy used by the virus to escape neutralizing immune responses. Further studies will show whether such a strategy plays a role in HIV infection of humans, how important that role could be, and what the mechanisms of infection enhancement are. The newly identified mAbs could be used as reagents to further characterize conserved non-neutralizing, weakly neutralizing or enhancing epitopes and modify or remove them from candidate vaccine immunogens

Interaction Modalities Used on Serious Games for Upper Limb Rehabilitation: A Systematic Review

This systematic review aims to analyze the state-of-the-art regarding interaction modalities used on serious games for upper limb rehabilitation. A systematic search was performed in IEEE Xplore and Web of Science databases. PRISMA and QualSyst protocols were used to filter and assess the articles. Articles must meet the following inclusion criteria: they must be written in English; be at least four pages in length; use or develop serious games; focus on upper limb rehabilitation; and be published between 2007 and 2017. Of 121 articles initially retrieved, 33 articles met the inclusion criteria. Three interaction modalities were found: vision systems (42.4%), complementary vision systems (30.3%), and no-vision systems (27.2%). Vision systems and no-vision systems obtained a similar mean QualSyst (86%) followed by complementary vision systems (85.7%). Almost half of the studies used vision systems as the interaction modality (42.4%) and used the Kinect sensor to collect the body movements (48.48%). The shoulder was the most treated body part in the studies (19%). A key limitation of vision systems and complementary vision systems is that their device performances might be affected by lighting conditions. A main limitation of the no-vision systems is that the range-of-motion in angles of the body movement might not be measured accurately. Due to a limited number of studies, fruitful areas for further research could be the following: serious games focused on finger rehabilitation and trauma injuries, game difficulty adaptation based on user's muscle strength and posture, and multisensor data fusion on interaction modalities