Effect of periodic backwash in the submerged membrane adsorption hybrid system

The submerged membrane adsorption hybrid system (SMAHS) is an attractive solution in treating wastewater; however it faces membrane fouling although to a less extent. In this study, different adsorbents and resins were investigated in order to find a substitute to the powdered activated carbon (PAC); The effect of new backflush was also studied in further reducing the membrane fouling. The SMAHS led to 72–86% dissolved organic carbon (DOC) removal. A detailed study on the transmembrane pressure development led to a conclusion that there is a critical flux and this value is around 16 l/h.m2 for the wastewater studied

The Effect of Social Anxiety and Approachability on Motivation in Online Classrooms

A Research Methods Project supervised by Dr. Hilary Stebbins (Spring 2021)

An investigation into the structure and localisation of the bacterial twin arginine translocase (Tat) complexes by electron microscopy

The twin arginine translocase (Tat) pathway is expressed in the inner membrane of both Gram-negative and Gram-positive bacteria. The model organism for each of these bacteria is Escherichia coli and Bacillus subtilis, respectively. In B. subtilis the Tat machinery is comprised of only TatA and TatC subunits. Namely, TatAdCd and TatAyCy translocases, which act in parallel, yet possess different substrate specificities. Little structural information is known about these multimeric integral membrane protein complexes owing to the difficulty in their purifications, small size and compositional heterogeneity. A primary structural investigation was performed on TatAyCy to gauge the true molecular weight and heterogeneity of this complex, providing fundamental insight into the effect that detergent solubilisation can have on a detergent-solubilised protein. Therefore, I circumvented the use of detergent and analysed Tat machinery in its native cellular environment. To achieve this, I developed a novel combinatorial approach of immunogold labelling with the volumetric microscopy technique- array tomography. The E. coli Tat system is comprised of three proteins: TatA, TatB and TatC. TatA is believed to constitute the protein-conducting element of the translocase machinery. However recent structural data has cast doubt on the biological significance of the properties of this protein, and consequently its role in the translocation process. Therefore, by using array tomography, I endeavoured to directly visualise TatA in its native cellular environment to gain insight into the localisation and distribution of this protein in E. coli. TatA was shown to cluster along the inner membrane in a TatBC-dependent manner. This is the first time that any Tat component has been visualised in 3D space, in situ. Additionally, the detailed insight into the exploitation of Tat machinery for the export of high value, biotechnologically-relevant protein was investigated; with a potential for this translocase to be used in cell surface display technologies revealed

Couplage de procédés physico-chimiques et séparation par membranes pour la rétention de matières organiques dans les eaux.

Les eaux naturelles comme les effluents secondaires produits par les stations d’épuration contiennent des matières organiques qui constituent actuellement l’une des cibles prioritaires des filières de production d’eau potable ou de réutilisation des eaux usées. Les membranes de Microfiltration et d’Ultrafiltration ne retiennent que très partiellement ces composés organiques de faible masse moléculaire qui sont par ailleurs responsables de phénomènes importants de colmatage. Un réacteur à membranes immergées analogue dans son principe aux bio réacteurs à membrane semble constituer un outil adapté pour réaliser simultanément dans le même équipement la réaction physico-chimique et la séparation membranaire. Les résultats présentés concernent les deux aspects : ils ont été obtenus sur des effluents secondaires ou des solutions de matières humiques : · Recherche d’un adsorbant ou d’une résine échangeuse d’ions susceptible de constituer une alternative au charbon actif en poudre utilisé jusqu’ici, en permettant notamment une régénération plus facile. · Essais à l’échelle pilote sur un réacteur à membranes immergées

Seasonal regulation of petal number

International audienceFour petals characterize the flowers of most species in the Brassicaceae family, and this phenotype is generally robust to genetic and environmental variation. A variable petal number distinguishes the flowers of Cardamine hirsuta from those of its close relative Arabidopsis (Arabidopsis thaliana), and allelic variation at many loci contribute to this trait. However, it is less clear whether C. hirsuta petal number varies in response to seasonal changes in environment. To address this question, we assessed whether petal number responds to a suite of environmental and endogenous cues that regulate flowering time in C. hirsuta. We found that petal number showed seasonal variation in C. hirsuta, such that spring flowering plants developed more petals than those flowering in summer. Conditions associated with spring flowering, including cool ambient temperature, short photoperiod, and vernalization, all increased petal number in C. hirsuta. Cool temperature caused the strongest increase in petal number and lengthened the time interval over which floral meristems matured. We performed live imaging of early flower development and showed that floral buds developed more slowly at 15°C versus 20°C. This extended phase of floral meristem formation, coupled with slower growth of sepals at 15°C, produced larger intersepal regions with more space available for petal initiation. In summary, the growth and maturation of floral buds is associated with variable petal number in C. hirsuta and responds to seasonal changes in ambient temperature

Reflecting on Pupil Learning to Promote Social Justice: A Catholic University’s Approach to Assessment

In contrast to current education policies that conceptualize pupil learning largely in terms of standardized exam scores, we offer an alternative view, one that conceives of pupil learning as a source of insight for pupils and teachers alike. Drawing on survey data and a qualitative study of the teacher candidate experience, we explore the following questions: In a teacher education program committed to promoting social justice, embracing an inquiry-into-practice stance, and affirming diversity by meeting the needs of diverse learners, how do teacher candidates assess pupil learning, in particular, how are their assessments influenced by these program themes? Further, how do they respond when dilemmas linked to pupil learning arise? Specifically, we focused on dilemmas two teacher candidates encountered that engendered a sense of “disequilibrium,” a feeling something was not quite right with their teaching. In turn, we consider how they responded”typically taking ownership of dilemmas and modifying their teaching, while occasionally distancing themselves from responsibility for pupil performance. To conclude, we discuss implications for teacher educators, and specifically for Catholic institutions of higher education that prepare teachers for both public and Catholic schools

Reflecting on Pupil Learning to Promote Social Justice: A Catholic University\u27s Approach to Assessment

In contrast to current education policies that conceptualize pupil learning largely in terms of standardized exam scores, we offer an alternative view, one that conceives of pupil learning as a source of insight for pupils and teachers alike. Drawing on survey data and a qualitative study of the teacher candidate experience, we explore the allowing questions: In a teacher education program committed to promoting social justice, embracing an inquiry-into-practice stance, and affirming diversity by meeting the needs of diverse learners, how do teacher candidates assess pupil learning, in particular, how are their assessments influenced by these program themes? Further, how do they respond when dilemmas linked to pupil learning arise? Specifically, we focused on dilemmas two teacher candidates encountered that engendered a sense of disequilibrium,” a feeling something was not quite right with their leaching. In turn; we consider how they responded-typically taking ownership of dilemmas and modifying their teaching, while occasionally distancing themselves from responsibility for pupil performance. To conclude, we discuss implications for teacher educators, and specifically for Catholic institutions of higher education that prepare teachers for both public and Catholic schools

Reflecting on Pupil Learning to Promote Social Justice: A Catholic University\u27s Approach to Assessment

In contrast to current education policies that conceptualize pupil learning largely in terms of standardized exam scores, we offer an alternative view, one that conceives of pupil learning as a source of insight for pupils and teachers alike. Drawing on survey data and a qualitative study of the teacher candidate experience, we explore the following questions: In a teacher education program committed to promoting social justice, embracing an inquiry-into-practice stance, and affirming diversity by meeting the needs of diverse learners, how do teacher candidates assess pupil learning, in particular, how are their assessments influenced by these program themes? Further, how do they respond when dilemmas linked to pupil learning arise? Specifically. we focused on dilemmas two teacher candidates encountered that engendered a sense of disequilibrium, a.feeling something was not quite right with their teaching. In turn, we consider how they responded - typically taking ownership of dilemmas and modifying their teaching, while occasionally distancing themselves from responsibility for pupil performance. To conclude, we discuss implications for teacher educators, and specifically for Catholic institutions of higher education that prepare teachers for both public and Catholic schools