Alumina Membranes for Desalination and Water Treatment

In recent years, there has been a growing interest in utilizing inorganic membranes, particularly alumina (Al2O3) ceramic membranes (CMs), and to address a variety of separation problems in miscellaneous industry. Al2O3 membranes are commercially predominant in CMs market. Al2O3 material is generally used either as membrane support and/or as membrane layer due to advantages provided by this material and its derivatives such as availability in tonnage quantities, chemical inertness, good hardness, and thermal stability of the porous texture during elaboration steps. In this chapter, we comprehensibly look at the recent studies related to desalination and water treatment by ultrafiltration (UF), nanofiltration (NF) Al2O3 membrane, and highlight the separation properties of the membrane in specific environmental pollution. The influences of membrane operating conditions and water quality on the rejection of pollutant by Al2O3 membrane are reported through a series of bench-level experiments

Function of FMRP by analyzing its interactors

Le Syndrome de l'X fragile (FXS) est la forme la plus fréquente de retard mental héréditaire. Il est causé par l’inactivation du gène FMR1 codant une RNA Binding Protein (FMRP) impliquée dans le contrôle de la traduction. Afin de mieux comprendre la fonction de FMRP, nous nous somme intéressé à ses interacteurs et mon travail s’est organisé en deux parties: la caractérisation de l'interaction FMRP/ARNm GRK4 et la caractérisation de la fonction neuronale de CYFIP1/2, deux protéines interacteurs de FMRP. Nous avons confirmé l'interaction FMRP/ARNm GRK4 et identifié une portion contenant deux motifs ACUK / WGGA, connu pour être de nouvelles cibles pour FMRP. FMRP se lie à GRK4 via son domaine RGG-box et régule négativement sa traduction. Dans les cellules granulaires du cervelet, GRK4 se lie au récepteur GABABR(GBR), induisant sa désensibilisation. Sachant l’importance de la signalisation GBR du cervelet dans la coordination motrice, un niveau élevé de GRK4 peut contribuer au déficit de l'apprentissage moteur et la coordination des mouvements dans FXS. Nous avons également caractérisé la fonction neuronale de CYFIP1/2 en induisant leur knockdown (KD). Ces protéines appartiennent au complexe WAVE (WRC) qui est impliqué dans la régulation de l’établissement de la polarité axonale et dendritique. Nous avons identifié un mécanisme de co-régulation de la transcription des ARNm codant les membres du WRC lors de l’altération de l'expression de CYFIP1/2. Le KD CYFIP1/2 modifie également neuronale ramification et connectivités. L'interaction de FMRP/CYFIP1/2 permettrait de comprendre les mécanismes impliqués dans le développement des anomalies des épines dendritiques dans FXS.Fragile X syndrome (FXS) is the most common form of inherited mental retardation. It is caused by the silencing of the FMR1 gene, which encodes for an RNA-binding protein (FMRP) involved in translational control. To better understand the function of FMRP, we are interested in its interactors and so my work was organized into two main parts: the characterization of the interaction between FMRP and GRK4 mRNA and the characterization of the neuronal function of CYFIP1/2, two FMRP interacting proteins. We confirmed in vivo and in vitro the FMRP/ GRK4 mRNA interaction and identified a portion containing two ACUK/WGGA motifs, known to be a novel targets for FMRP. FMRP binds this target via its RGG box domain and negatively modulates the expression of GRK4 at the translational level only in cerebellum. In cerebellar granule cells, GRK4 interacts directly with the GABAB receptor (GBR), promoting its desensitization. Since in cerebellum GBR signaling has a relevant role in motor coordination, an elevated level of GRK4 can contribute to deficits of motor learning and movement coordination in FXS. Next, we characterized the function of CYFIP1/2 in neurons by inducing their knockdown (KD). CYFIP1/2 are components of the canonical WAVE regulatory complex (WRC), important in the spatiotemporal regulation of actin dynamics to get correct axonal and dendrites polarity and branching. We identified a co-regulation of transcription of mRNA coding the WRC members when the expression of CYFIP1/2 is disturbed. KD CYFIP1/2 also alters neuronal branching. The FMRP/CYFIP1/2 interaction would allow us to understand the mechanisms involved in the development of dendritic spines abnormalities in FXS

Εφαρμογή βιομιμητικών αρχών σε αειφόρα οικιστικά σύνολα: ο σχεδιασμός του οικοδομικού συνεταιρισμού στο Αμμούδι, Ηράκλειο

Μη διαθέσιμη περίληψηNot available summarizatio

Βιομιμητικές εφαρμογές στα οικιστικά σύνολα: οι προοπτικές συμβολής της φυσικής τεχνογνωσίας στην επίτευξη αειφόρου αστικού περιβάλλοντος

Περίληψη: Η φύση αποτελεί ένα εκτεταμένο «εγχειρίδιο» βιολογικών μηχανισμών, που με το παράδειγμά τους, μπορούν να δώσουν διεξόδους σε πολλά σύγχρονα προβλήματα που οι ζωντανοί οργανισμοί έχουν ήδη καταφέρει να λύσουν μέσω της εξελικτικής διαδικασίας. Σκοπός της παρούσας ερευνητικής εργασίας είναι η παρουσίαση ενός εναλλακτικού τρόπου διαχείρισης της σχέσης δομημένου και φυσικού περιβάλλοντος υπό το πρίσμα της βιομίμησης. Με έμφαση στα οικιστικά σύνολα, γίνεται διερεύνηση τόσο των δυνατοτήτων, όσο και των ορίων αυτής της πρακτικής, καταλήγοντας σε συμπεράσματα ως προς το μέγεθος της χρησιμότητας αλλά και της εφαρμοσιμότητας της.Presented on

Nitrate removal from aqueous solutions by γ-Al2O3 ultrafiltration membranes

In the framework of understanding the transport mechanism that governs the filtration of NO3− solution through a γ-Al2O3 membrane with a nominal pore size of 5 nm at low ultrafiltration, a series of various types of nitrate solutions and operating conditions were investigated. The effect of filtration parameters such as pH, applied pressure and NO3− concentration on the selectivity and permeability of the membrane were studied using binary solutions (KNO3, NaNO3, Ca(NO3)2 and Mg(NO3)2) and ternary solutions ((NaNO3 + KNO3), (NaNO3 + Ca(NO3)2) and (Mg(NO3)2 + Ca(NO3)2). The experimental filtration results showed that high NO3− rejection was observed when pH was close to the point of zero charge of the membrane for both binary and ternary solutions. NO3− rejection increased with an increase of applied pressure. The rejection gradually decreased when the initial NO3− concentration increased. It appeared that the valency and hydrated radius of associated cation had a dramatic effect on NO3− rejection, with the divalent cations being more rejected than monovalent cations. In order to get to natural water complexity, three different samples of mineral water doped with NO3− from two different sources were studied at optimized operating conditions (25 ppm of NO3− and 6 bar). Experimental results demonstrated that NO3− rejection strongly depended upon the total mineralization and the presence of divalent anions in solution. In addition, the obtained results showed the potential use of γ-Al2O3 ultrafiltration membrane for denitrificatoin of contaminated water especially in Moroccan agricultural areas