Tailoring properties and functionalities of TiO2 and Ag nanoparticles involved in surfaces engineering processes

The functionalization of substrates through the application of nanostructured coatings allows to create new materials, with enhanced properties. In this work, the development of self-cleaning and antibacterial textiles, through the application of TiO2 and Ag based nanostructured coatings was carried out. The production of TiO2 and Ag functionalized materials was achieved both by the classical dip-padding-curing method and by the innovative electrospinning process to obtain nanofibers doped with nano-TiO2 and nano-Ag. In order to optimize the production of functionalized textiles, the study focused on the comprehension of mechanisms involved in the photocatalytic and antibacterial processes and on the real applicability of the products. In particular, a deep investigation on the relationship between nanosol physicochemical characteristics, nanocoating properties and their performances was accomplished. Self-cleaning textiles with optimized properties were obtained by properly purifying and applying commercial TiO2 nanosol while the studies on the photocatalytic mechanism operating in self-cleaning application demonstrated the strong influence of hydrophilic properties and of interaction surface/radicals on final performance. Moreover, a study about the safety in handling of nano-TiO2 was carried out and risk remediation strategies, based on “safety by design” approach, were developed. In particular, the coating of TiO2 nanoparticles by a SiO2 shell was demonstrated to be the best risk remediation strategy in term of biological response and preserving of photoreactivity. The obtained results were confirmed determining the reactive oxygen species production by a multiple approach. Antibacterial textiles for biotechnological applications were also studied and Ag-coated cotton materials, with significant anti-bacterial properties, were produced. Finally, composite nanofibers were obtained merging biopolymer processing and sol-gel techniques. Indeed, electrospun nanofibers embedded with TiO2 and Ag NPs, starting from aqueous keratin based formulation were produced and the photocatalytic and antibacterial properties were assessed. The results confirmed the capability of electrospun keratin nanofibers matrix to preserve nanoparticle properties.

Early and late urodynamic assessment of ileal orthotopic bladder substitutes combined with an afferent tubular segment

PURPOSE: Limited information is available concerning changes in the urodynamic characteristics of orthotopic bladder substitutes with time. Therefore, we compared early and late urodynamic results in patients with an ileal orthotopic bladder substitute combined with an afferent tubular segment. MATERIALS AND METHODS: Of 139 patients surviving at least 5 years after cystoprostatectomy and ileal orthotopic bladder substitution with an afferent tubular segment 119 underwent urodynamic assessment, including 66 at a median of 9 months (early) and 77 at a median of 62 months (late). Of these patients 24 were assessed at each time point. Simultaneously all patients were asked to complete a bladder diary and questionnaire regarding continence for at least 3 days in the week preceding the urodynamic study. RESULTS: Urodynamic parameters were comparable in patients who were evaluated early and late postoperatively. In addition, median values at early and late urodynamic evaluation in the 24 patients with the 2 examinations showed no statistically significant differences for volume at first desire to void (300 vs 333 ml, p = 0.85), pressure at first desire to void (12 vs 13 cm H2O, p = 0.57), maximum cystometric capacity (450 vs 453 ml, p = 0.84), end filling pressure (19 vs 20 cm H2O, p = 0.17), reservoir compliance (25 vs 28 ml/cm H2O, p = 0.58) or post-void residual urine volume (5 vs 15 ml, p = 0.27). CONCLUSIONS: Urodynamic results after 5 years of living with an ileal orthotopic bladder substitute with an afferent tubular segment show grossly unchanged urodynamic characteristics. Patients maintain a reservoir capacity and micturition pattern consistent with a normal life-style. Reservoir pressure remained low, thereby protecting and preserving upper tract function. To achieve these results patients must be regularly followed, and the causes of bacteriuria, increased post-void residual urine and bladder outlet obstruction must be recognized and dealt with accordingly.

Common noncoding UMOD gene variants induce salt-sensitive hypertension and kidney damage by increasing uromodulin expression

Hypertension and chronic kidney disease (CKD) are complex traits representing major global health problems1,2. Multiple genome-wide association studies have identified common variants in the promoter of the UMOD gene3–9, which encodes uromodulin, the major protein secreted in normal urine, that cause independent susceptibility to CKD and hypertension. Despite compelling genetic evidence for the association between UMOD risk variants and disease susceptibility in the general population, the underlying biological mechanism is not understood. Here, we demonstrate that UMOD risk variants increased UMOD expression in vitro and in vivo. Uromodulin overexpression in transgenic mice led to salt-sensitive hypertension and to the presence of age-dependent renal lesions similar to those observed in elderly individuals homozygous for UMOD promoter risk variants. The link between uromodulin and hypertension is due to activation of the renal sodium cotransporter NKCC2. We demonstrated the relevance of this mechanism in humans by showing that pharmacological inhibition of NKCC2 was more effective in lowering blood pressure in hypertensive patients who are homozygous for UMOD promoter risk variants than in other hypertensive patients. Our findings link genetic susceptibility to hypertension and CKD to the level of uromodulin expression and uromodulin’s effect on salt reabsorption in the kidney. These findings point to uromodulin as a therapeutic target for lowering blood pressure and preserving renal function.

Pulmonary neuroendocrine (carcinoid) tumors: European Neuroendocrine Tumor Society expert consensus and recommendations for best practice for typical and atypical pulmonary carcinoids.

BACKGROUND Pulmonary carcinoids (PCs) are rare tumors. As there is a paucity of randomized studies, this expert consensus document represents an initiative by the European Neuroendocrine Tumor Society to provide guidance on their management. PATIENTS AND METHODS Bibliographical searches were carried out in PubMed for the terms 'pulmonary neuroendocrine tumors', 'bronchial neuroendocrine tumors', 'bronchial carcinoid tumors', 'pulmonary carcinoid', 'pulmonary typical/atypical carcinoid', and 'pulmonary carcinoid and diagnosis/treatment/epidemiology/prognosis'. A systematic review of the relevant literature was carried out, followed by expert review. RESULTS PCs are well-differentiated neuroendocrine tumors and include low- and intermediate-grade malignant tumors, i.e. typical (TC) and atypical carcinoid (AC), respectively. Contrast CT scan is the diagnostic gold standard for PCs, but pathology examination is mandatory for their correct classification. Somatostatin receptor imaging may visualize nearly 80% of the primary tumors and is most sensitive for metastatic disease. Plasma chromogranin A can be increased in PCs. Surgery is the treatment of choice for PCs with the aim of removing the tumor and preserving as much lung tissue as possible. Resection of metastases should be considered whenever possible with curative intent. Somatostatin analogs are the first-line treatment of carcinoid syndrome and may be considered as first-line systemic antiproliferative treatment in unresectable PCs, particularly of low-grade TC and AC. Locoregional or radiotargeted therapies should be considered for metastatic disease. Systemic chemotherapy is used for progressive PCs, although cytotoxic regimens have demonstrated limited effects with etoposide and platinum combination the most commonly used, however, temozolomide has shown most clinical benefit. CONCLUSIONS PCs are complex tumors which require a multidisciplinary approach and long-term follow-up.

Memory performance of and-parallel prolog on shared-memory architectures

The goal of the RAP-WAM AND-parallel Prolog abstract architecture is to provide inference speeds significantly beyond those of sequential systems, while supporting Prolog semantics and preserving sequential performance and storage efficiency. This paper presents simulation results supporting these claims with special emphasis on memory performance on a two-level sharedmemory multiprocessor organization. Several solutions to the cache coherency problem are analyzed. It is shown that RAP-WAM offers good locality and storage efficiency and that it can effectively take advantage of broadcast caches. It is argued that speeds in excess of 2 ML IPS on real applications exhibiting medium parallelism can be attained with current technology.

Control of a solar dryer through using a fuzzy logic and low-cost model-based sensor

Solar drying is one of the important processes used for extending the shelf life of agricultural products. Regarding consumer requirements, solar drying should be more suitable in terms of curtailing total drying time and preserving product quality. Therefore, the objective of this study was to develop a fuzzy logic-based control system, which performs a ?human-operator-like? control approach through using the previously developed low-cost model-based sensors. Fuzzy logic toolbox of MatLab and Borland C++ Builder tool were utilized to develop a required control system. An experimental solar dryer, constructed by CONA SOLAR (Austria) was used during the development of the control system. Sensirion sensors were used to characterize the drying air at different positions in the dryer, and also the smart sensor SMART-1 was applied to be able to include the rate of wood water extraction into the control system (the difference of absolute humidity of the air between the outlet and the inlet of solar dryer is considered by SMART-1 to be the extracted water). A comprehensive test over a 3 week period for different fuzzy control models has been performed, and data, obtained from these experiments, were analyzed. Findings from this study would suggest that the developed fuzzy logic-based control system is able to tackle difficulties, related to the control of solar dryer process.

Functional and environmental design of detached, low crest level breakwaters

In this article we research the design of detached breakwaters, a type of coastal defence work designed to combat erosion on beaches in a stable, sustainable fashion. Our aim is to formulate a functional and environmental (nonstructural) method of design that defines the fundamental characteristics of a detached breakwater as a function of the desired effect on the coast whilst meeting social demands and preserving or improving the quality of the littoral environment. We aim to make this method generally applicable by considering relations between variables of different natures (climatic, geomorphologic, and geometric) influencing the changes experienced on the coast after the detached breakwater has been built. We carried out the study of the relations between the different variables on the data from 19 actual, existing detached breakwaters on the Spanish Mediterranean coastline, and we followed a methodology based on the implementation of nondimensional monomials and on a search for relations of dependency between them. Finally, we discussed the results obtained and came up with a proposal for a design method that uses some of the graphic relations found between the variables studied and that achieves the main objective. For example, a case of a detached breakwater’s geometric presizing is solved as a practical demonstration of how the method is applied. La investigación que se presenta en este artículo aborda el diseño de los diques exentos, por constituir estos un tipo de obras de defensa costera con el que poder luchar de una forma estable y sostenible contra muchos de los problemas de erosión que existen en las playas. El objetivo principal de este trabajo es la formulación de un método de diseño funcional y ambiental (no estructural) que permita definir las características fundamentales de un dique exento en función del efecto que se quiera inducir en la costa, satisfaciendo las demandas sociales y preservando o mejorando la calidad del medio ambiente litoral. Además, se busca la aplicabilidad general del método mediante la consideración de relaciones entre variables de distinta naturaleza (climáticas, geomorfológicas y geométricas) que tienen influencia en los cambios que se experimentan en la costa tras la construcción del dique exento. El estudio de las relaciones entre las distintas variables se realiza sobre los datos de una base de diecinueve diques exentos reales, existentes en el litoral mediterráneo español, y sigue una metodología basada en el planteamiento de monomios adimensionales y en la búsqueda de relaciones de dependencia entre ellos. Finalmente, la discusión de los resultados obtenidos conduce a la propuesta de un método de diseño que utiliza algunas de las relaciones graficas encontradas entre las variables estudiadas y con el que se consigue el objetivo principal anteriormente expuesto. Para demostrar la aplicación práctica del método se resuelve un caso de predimensionamiento geométrico de un dique exento a modo de ejemplo.

THE DESIGN AND SYNTHESIS OF SILOXANE PRECURSORS FOR CHIRAL PERIODIC MESOPOROUS ORGANOSILICA MATERIALS

The development of cost-effective and reliable methods for the synthesis and separation of asymmetric compounds is paramount in helping to meet society’s ever-growing demand for chiral small molecules. Of these methods, chiral heterogeneous supports are particularly appealing as they allow for the reuse of the chiral source. One such support, based on the synergy between chiral organic units and structurally stable inorganic silicon scaffolds are periodic mesoporous organosilicas (PMOs). In the work described herein, I examine some of the factors governing the transmission of chirality between chiral dopants and prochiral bulk phases in chiral PMO materials. In particular, the exploration of 1,1’-binaphthalene-bridged chiral dopants with a focus on the point of attachment into the materials. Moreover, the effects of ordering in the materials are examined and reveal that chirality transfer is more facile in materials with molecular-scale order then those containing amorphous walls. Secondly, the issues surrounding the synthesis and purification of aryl-triethoxysilanes as siloxane precursors are addressed. Both the introduction of a two-carbon linker and the direct attachment of allyl and mixed allyldiethoxysilane species are explored. This work demonstrates that allyldiethoxysilanes are ideal, in that they are stable enough to permit facile synthesis, while still being able to hydrolyze completely to produce well-ordered materials. Lastly, the production of new bulk phases for chiral PMO materials is examined by introducing new prochiral nitrogen-containing siloxane precursors. Biphenyldiamine and bipyridine-bridged siloxane precursors are readily synthesized on reasonable scales. Their use as the bulk siloxane precursor in the production of PMO materials however, is precluded by insufficient gelation and additional siloxane precursors are necessary for the production of ordered materials. In addition to the research detailed above that forms the body of this thesis, two short works are appended. The first details the production of polythiophene assemblies mediated through coordination nanospaces, while the second explores the production of N-heterocyclic carbene functionalized gold nanoparticles through ligand exchange.

SOCIAL, EMOTIONAL, COGNITIVE, AND PHYSIOLOGICAL CORRELATES OF ELECTRONIC SOCIAL BEHAVIOR

There has been very little research that has studied the capacities that can be fostered to mitigate the risk for involvement in electronic bullying or victimization and almost no research examining positive electronic behavior. The primary goal of this dissertation was to use the General Aggression Model and Anxious Apprehension Model of Trauma to explore the underlying cognitive, emotional, and self-regulation processes that are related to electronic bullying, victimization, and prosocial behavior. In Study 1, we explored several potential interpretations of the General Aggression Model that would accurately describe the relationship that electronic self-conscious appraisal, cognitive reappraisal, and activational control may have with electronic bullying and victimization. In Study 2, we used the Anxious Apprehension Model of Trauma to explore rejection cognitions as the mediator of the relationships among emotionality (emotionality, shame, state emotion responses, and physiological arousal) and electronic bullying and victimization using structural equation modelling. In addition, we explored the role of rejection cognitions in mediating the relationship of moral disengagement with electronic bullying. In Study 3, we examined predictors of electronic prosocial behavior, such as bullying, victimization, time online, electronic proficiency, electronic self-conscious appraisals, emotionality, and self-regulation. All three studies supported the General Aggression Model as a framework to guide the study of electronic behavior, and suggest the importance of cognitive, emotional, and behavioral means of regulation in shaping electronic behavior. In addition, each study has implications for the development of high quality electronic bullying prevention and intervention research.

Identification of YAP as sperm-PAWP’s predominant binding partner in MII-arrested oocytes and the relevance of this WWI domain modular interaction to oocyte activation

PAWP, a candidate sperm-borne oocyte activating factor, induces oocyte activation and acts upstream of the calcium signalling pathway, however, PAWP’s downstream signalling pathway in oocyte cytoplasm remains to be uncovered. Data from our lab suggested that the interacting partner of PAWP, at least in the frog (Xenopus laevis) model may be YAP, a highly expressed protein in amphibian and mammalian oocytes. Therefore, the objectives of this study were to confirm that PAWP’s predominant binding partner in Xenopus laevis oocyte is YAP; to determine if mammalian oocyte activation is also dependent on PAWP-YAP interaction; and to verify that the PAWP-YAP interaction during oocyte activation is dependent on the WWI domain module. By immunohistochemistry, YAP was localized predominantly in the cytosol of metaphase II-arrested Xenopus laevis oocytes, where presumably the PAWP-YAP interaction occurs. Utilizing Far Western blotting, YAP was identified as the predominant binding partner of PAWP, in metaphase II-arrested frog (Xenopus laevis), swine (Sus scrofa) and mouse (mus musculus) oocytes. The specificity of this interaction was then tested on Far Western blotting of mouse ovarian and oocyte cytosolic extracts, by competition with both wild-type and point-mutated recombinant WWI domains derived from YAP. The removal of GST from the wild-type WWI-GST fusion protein was a requirement for effective blockage of WWI module interaction between PAWP and YAP. As expected, the mutated WWI domain was ineffective in inhibiting the PAWP-YAP interaction. To conclude, this study identified YAP as the predominant binding partner of PAWP in both amphibian and mammalian oocytes, and showed this interaction is dependent on the WWI modular interaction. The results allow us to test the functional relevance of this WWI modular interaction during oocyte activation in vivo, in the future.

The Modelling of Photovoltaic, Solar Thermal, and Photovoltaic/Thermal Domestic Hot Water Systems

Solar heating of potable water has traditionally been accomplished through the use of solar thermal (ST) collectors. With the recent increases in availability and lower cost of photovoltaic (PV) panels, the potential of coupling PV solar arrays to electrically heated domestic hot water (DHW) tanks has been considered. Additionally, innovations in the SDHW industry have led to the creation of photovoltaic/thermal (PV/T) collectors, which heat water using both electrical and thermal energy. The current work compared the performance and cost-effectiveness of a traditional solar thermal (ST) DHW system to PV-solar-electric DHW systems and a PV/T DHW system. To accomplish this, a detailed TRNSYS model of the solar hot water systems was created and annual simulations were performed for 250 L/day and 325 L/day loads in Toronto, Vancouver, Montreal, Halifax, and Calgary. It was shown that when considering thermal performance, PV-DHW systems were not competitive when compared to ST-DHW and PVT-DHW systems. As an example, for Toronto the simulated annual solar fractions of PV-DHW systems were approximately 30%, while the ST-DHW and PVT-DHW systems achieved 65% and 71% respectively. With current manufacturing and system costs, the PV-DHW system was the most cost-effective system for domestic purposes. The capital cost of the PV-DHW systems were approximately $1,923-$2,178 depending on the system configuration, and the ST-DHW and PVT system were estimated to have a capital cost of $2,288 and $2,373 respectively. Although the capital cost of the PVT-DHW system was higher than the other systems, a Present Worth analysis for a 20-year period showed that for a 250 L/day load in Toronto the Present Worth of the PV/T system was approximately $4,597, with PV-DHW systems costing approximately $7,683-$7,816 and the ST-DHW system costing $5,238.

Performing Pedagogies and Exploring Embodied Knowledge as Curatorial Investigation

Performing Pedagogies was a week-long performance and exhibition series I organized that took place in Kingston, Ontario between March 15th - March 20th 2016. The motivation for this project came from a desire to explore performative modes of experiencing critical, embodied knowledge. The series featured five performances, a long distance collaboration between thirty-one Queen’s undergraduate students and a Vancouver artist-run free school (The School for Eventual Vacancy), a subsequent exhibition, a panel discussion, and a radical performance pedagogy workshop led by co-artistic director of the international performance art troupe, La Pocha Nostra. Artists featured included Golboo Amani, Basil AlZeri, Caitlin Chaisson, Justin Langlois, Saul Garcia-Lopez, Francisco-Fernando Granados, and Andrew Rabyniuk. By curating examples of performance art that variously incorporated embodied pedagogical interventions, I examined the processes of performance as pedagogy. Performing Pedagogies explored interventions into contemporary contours of neoliberal education paradigms through embodied encounters—fostering conversations about the meanings and limitations of knowledge dissemination and education today and posing questions about possibilities for radical pedagogies, embodied knowledge, and counter curricula.

Countermanding in rats as a practical model for investigation of adaptive control of behaviour, lifespan changes in behavioural control and neurotransmitter function

The countermanding paradigm was designed to investigate the ability to cancel a prepotent response when a stop signal is presented and allows estimation of the stop signal response time (SSRT), an otherwise unobservable behaviour. Humans exhibit adaptive control of behaviour in the countermanding task, proactively lengthening response time (RT) in expectation of stopping and reactively lengthening RT following stop trials or errors. Human performance changes throughout the lifespan, with longer RT, SSRT and greater emphasis on post-error slowing reported for older compared to younger adults. Inhibition in the task has generally been improved by drugs that increase extracellular norepinephrine. The current thesis examined a novel choice response countermanding task in rats to explore whether rodent countermanding performance is a suitable model for the study of adaptive control of behaviour, lifespan changes in behavioural control and the role of neurotransmitters in these behaviours. Rats reactively adjusted RT in the countermanding task, shortening RT after consecutive correct go trials and lengthening RT following non-cancelled, but not cancelled stop trials, in sessions with a 10 s, but not a 1 s post-error timeout interval. Rats proactively lengthened RT in countermanding task sessions compared to go trial-only sessions. Together, these findings suggest that rats strategically lengthened RT in the countermanding task to improve accuracy and avoid longer, unrewarded timeout intervals. Next, rats exhibited longer RT and relatively conserved post-error slowing, but no significant change in SSRT when tested at 12, compared to 7 months of age, suggesting that rats exhibit changes in countermanding task performance with aging similar to those observed in humans. Finally, acute administration of yohimbine (1.25, 2.5 mg/kg) and d-amphetamine (0.25, 0.5 mg/kg), which putatively increase extracellular norepinephrine and dopamine respectively, resulted in RT shortening, baseline-dependent effects on SSRT, and attenuated adaptive RT adjustments in rats in the case of d-amphetamine. These findings suggest that dopamine and norepinephrine encouraged motivated, reward-seeking behaviour and supported inhibitory control in an inverted-U-like fashion. Taken together, these observations validate the rat countermanding task for further study of the neural correlates and neurotransmitters mediating adaptive control of behaviour and lifespan changes in behavioural control.

Surveillance Studies and the Surveilled Subject

Surveillance studies has been somewhat inattentive to the perspective of the surveilled subject. It is the functioning of the surveillance apparatus, not the relatively inconsequential subject, which has tended to frame the focus of surveillance inquiries; leaving understandings of surveilled subjects’ experiences relatively limited. This research addresses this gap in the literature, exploring ways in which surveillance studies might understand the surveilled subject with greater consistency. Participants (N=47) shared their encounters with and perceptions of surveillance in a specific (Pearson International Airport) and general (everyday life) context through semi-structured interviews. The findings suggest that surveilled subjects’ encounters can be understood with some consistency – characterized by consistent criteria across subjects and contexts, and through a consistent theoretical framework across subjects in a specific context. However, consistency should not be confused with uniformity; encounters with surveillance must also be recognized for the extent to which they are nuanced and situated. For example, as this study also highlights, participants’ perceptions of encounters with surveillance at Pearson International Airport were differentially distributed in relation to identity characteristics (particularly minority status).

BEYOND WORDS: HOW LEARNING TO READ AND MENTAL HEALTH ARE RELATED FOR STRUGGLING READERS

The overarching purpose of this research program was to describe how intervening for academic deficits may be accompanied by changes in mental health. This multi-dimensional, multi-perspective, and iterative research program was developed to report on two distinct but related studies that addressed the same issue: in what ways does the mental health of students change as they transition from being struggling readers to more able readers? To describe the changes, these studies used a number of qualitative research methodologies—focus groups, individual interviews, and ethnographic case studies. Themes that emerged from the focus group and interview data in the first study were used to create a model that guided observations and interview questions in the second study. The first study described what parents, classroom teachers, and two reading instructors of nine previously struggling readers reported as the outcomes of becoming a more proficient reader. Data from this study indicated three broad domains in which change, as perceived by participants, occurred―cognitive/learning, behavioural/social, and psychological/emotional. Within these three domains, six dimensions were identified as having changed as reading improved: (a) academic achievement, (b) attitude, (c) attention, (d) behaviour, (e) mental health, and (f) empowerment. These domains, dimensions, and 15 constituent elements were used to create the model to guide the subsequent study. The purpose of the second study was to validate and refine this model by using an ethnographic case study approach to explore the ways in which the model accounted for the changes in reading and mental health seen in three boys over the months they participated in the intervention. By investigating the relationship between learning to read and mental health, this research aimed to enhance our understanding of how gains in reading may also improve the mental health of struggling readers. The model was found to be robust and a convenient conceptual framework to further our understanding of this relationship. Importantly, gains made in the cognitive/learning domain through an effective reading intervention, offered in a supportive learning environment, were shown to be accompanied by concomitant gains in both the behavioural/social and psychological/emotional domains—all of which enhance student thriving.