Jeffrey Moore’s The Memory Artists: Synaesthesia, Science, and the Art of Memory

Jeffrey Moore’s The Memory Artists (2004) represents a recent turn in contemporary Canadian literature involving texts that investigate the implications, ethics, histories, and epistemological power structures of science, scientific theories, and the linguistic and philosophical interplay between literature and science. Attending to the philosophical tradition of Henri Bergson, Silvan Tomkins, and Jean-Paul Sartre highlights the ways in which the representation of biological conditions such as synaesthesia and hypermnesia, as well as Alzheimer’s and amnesia, inform The Memory Artists – how the chemical makeup of individuals produces different ways of knowing the world and forces us to question what separates human knowledge from the material body in which it arises. In doing so, the novel reconstitutes the traditional boundaries between memory and matter, science and art, and the fictional and factual into a sliding scale of degrees of difference

Recovery of noble metal elements from effluents of the semiconductor industry as nanoparticles, by dielectric barrier discharge (DBD) plasma treatment

The fabrication of semiconductor products for the microelectronic industry requires the deposition of thin noble metal layers (e.g. Au-Sn and Pd) by means of processes involving fluid baths that contain metal ions (e.g. electrowinning and electroless plating). After several cycles, the plating solutions are used up and must be replaced, generating large volumes of discarded solutions containing precious metals. The metals (Au and Pd) are recovered either by electrowinning, a slow batch process, or by the use of toxic molecules (e.g. cyanides). This study demonstrates the possibility of using an atmospheric plasma technology to recover Au and Pd from these solutions, which provides a faster and greener process. Plasma discharges are generated at the surface of the solutions, causing ions to precipitate as nanoparticles. The treatment (few minutes only) allows the recovery of >95% gold, and >60% palladium. The process separates Au (NPs) from Sn ions (remaining in solution), as confirmed by elemental analysis and XPS. Particle size distributions of the nanoparticles recovered through the process suggests that as- synthesized nanoparticles could integrate value-added products (e.g. catalyst industry). Overall, the use of plasma technology could open several possibilities for the recycling of metals contained in solutions discarded from the semiconductor industry

Les fins d’emploi de carrière et les emplois de transition vers la retraite selon la profession au Canada, 2002 à 2007

Le vieillissement de la main-d’œuvre canadienne entraîne diverses conséquences sur le marché du travail et sur les parcours de fin de vie active. C’est pourquoi cette recherche s’intéresse à la problématique des fins d’emploi de carrière et du passage vers un emploi de transition vers la retraite. À l’aide des données longitudinales de l’Enquête sur la dynamique du travail et du revenu de 2002 à 2007, l’objectif est de mener une analyse descriptive de cette trajectoire selon la profession, ce qui ne semble jamais avoir été fait dans la littérature canadienne. Les résultats montrent que certaines professions ont enregistré proportionnellement plus de fins d’emploi de carrière durant cette période, dont les enseignants et les occupants d’un poste de direction. Des analyses supplémentaires ont calculé la part des travailleurs ayant effectué leur transition dans une profession différente.In Canada, the ongoing aging of the labour force has direct effects on the labour market and the way workers live their transition to retirement. Thus many believe in the importance of studying the lifecourse of older workers. Using longitudinal data from the Survey of Labour and Income Dynamics, this study analyzes the older workers who left a career job between 2002 and 2007, and looks at their subsequent labour market activity in order to know if some of them entered a bridge job. This research focuses on occupational differences for the first time in the Canadian literature. In proportion, the results show higher than average rates of leaving their career job in some specific occupations, especially teachers and managers. Moreover this study aims to measure the proportion of older workers who found a bridge job in a different occupation

Rapid, one-pot procedure to synthesise 103Pd:Pd@Au nanoparticles en route for radiosensitisation and radiotherapeutic applications

The radioisotope palladium (103Pd), encapsulated in millimetre-size seed implants, is widely used in prostate cancer brachytherapy. Gold nanoparticles (Au NPs) distributed in the vicinity of 103Pd radioactive implants, strongly enhance the therapeutic dose of radioactive implants (radiosensitisation effect). A new strategy under development to replace millimetre-size implants, consist in injecting radioactive NPs in the affected tissues. The development of 103Pd@Au NPs distributed in the diseased tissue, could increase the uniformity of treatment (compared with massive seeds), while enhancing the radiotherapeutic dose to the cancer cells (through Au-mediated radiosensitisation effect). To achieve this goal, it is necessary to develop a rapid, efficient, one-pot and easy-to-automatise procedure, allowing the synthesis of coreshell Pd@Au NPs. The novel synthesis route proposed here enables the production of Pd@Au NPs in not more than 4h, in aqueous media, with minimal manipulations, and relying on biocompatible and non-toxic molecules. This rapid multi-step process consists of the preparation of ultra-small Pd NPs by chemical reduction of an aqueous solution of H2PdCl4 supplemented with ascorbic acid (AA) as reducing agent and 2, 3-meso-dimercaptosuccinic acid (DMSA) as a capping agent. Pd conversion yields close to 87% were found, indicating the efficiency of the reaction process. Then Pd NPs were used as seeds for the growth of a gold shell (Pd@Au), followed by grafting with polyethylene glycol (PEG) to ensure colloidal stability. Pd@Au-PEG (TEM: 20.2 ± 12.1 nm) formed very stable colloids in saline solution as well as in cell culture medium. The physico-chemical properties of the particles were characterised by FTIR, XPS, and UV-vis. spectroscopies. The viability of PC3 human prostate cancer cells was not affected after a 24-h incubation cycle with Pd@Au-PEG NPs to concentrations up to 4.22 mM Au. Finally, suspensions of Pd@Au-PEG NPs measured in computed tomography (CT) are found to attenuate X-rays more efficiently than commercial Au NPs CT contrast media. A proof-of-concept was performed to demonstrate the possibility synthesise radioactive 103Pd:Pd@Au-PEG NPs. This study reveals the possibility to synthesise Pd@Au NPs rapidly (including radioactive 103Pd:Pd@Au-PEG NPs), and following a methodology that respects all the strict requirements underlying the production of NPs for radiotherapeutic use (rapidity, reaction yield, colloidal stability, NPs concentration, purification)

Magnetic resonance imaging of human tissue-engineered adipose substitutes

Adipose tissue (AT) substitutes are being developed to answer the strong demand in reconstructive surgery. To facilitate the validation of their functional performance in vivo, and to avoid resorting to excessive number of animals, it is crucial at this stage to develop biomedical imaging methodologies, enabling the follow-up of reconstructed AT substitutes. Until now, biomedical imaging of AT substitutes has scarcely been reported in the literature. Therefore, the optimal parameters enabling good resolution, appropriate contrast, and graft delineation, as well as blood perfusion validation, must be studied and reported. In this study, human adipose substitutes produced from adipose-derived stem/stromal cells using the self-assembly approach of tissue engineering were implanted into athymic mice. The fate of the reconstructed AT substitutes implanted in vivo was successfully followed by magnetic resonance imaging (MRI), which is the imaging modality of choice for visualizing soft ATs. T1-weighted images allowed clear delineation of the grafts, followed by volume integration. The magnetic resonance (MR) signal of reconstructed AT was studied in vitro by proton nuclear magnetic resonance (1H-NMR). This confirmed the presence of a strong triglyceride peak of short longitudinal proton relaxation time (T1) values (200±53 ms) in reconstructed AT substitutes (total T1=813±76 ms), which establishes a clear signal difference between adjacent muscle, connective tissue, and native fat (total T1 ∼300 ms). Graft volume retention was followed up to 6 weeks after implantation, revealing a gradual resorption rate averaging at 44% of initial substitute's volume. In addition, vascular perfusion measured by dynamic contrast-enhanced-MRI confirmed the graft's vascularization postimplantation (14 and 21 days after grafting). Histological analysis of the grafted tissues revealed the persistence of numerous adipocytes without evidence of cysts or tissue necrosis. This study describes the in vivo grafting of human adipose substitutes devoid of exogenous matrix components, and for the first time, the optimal parameters necessary to achieve efficient MRI visualization of grafted tissue-engineered adipose substitutes

A nanoparticle ink allowing the high precision visualization of tissue engineered scaffolds by MRI

Hydrogels are widely used as cell scaffolds in several biomedical applications. Once implanted in vivo, cell scaffolds must often be visualized, and monitored overtime. However, cell scaffolds appear poorly contrasted in most biomedical imaging modalities such as magnetic resonance imaging (MRI). MRI is the imaging technique of choice for high-resolution visualization of low-density, water-rich tissues. Attempts to enhance hydrogel contrast in MRI are performed with “negative” contrast agents that produce several image artifacts impeding the delineation of the implant’s contours. In this study, a magnetic ink based on ultra-small iron oxide nanoparticles (USPIONs; <5 nm diameter cores) is developed and integrated into biocompatible alginate hydrogel used in cell scaffolding applications. Relaxometric properties of the magnetic hydrogel are measured, as well as biocompatibility and MR-visibility (T1-weighted mode; in vitro and in vivo). A 2-week MR follow-up study is performed in the mouse model, demonstrating no image artifacts, and the retention of “positive” contrast overtime, which allows very precise delineation of tissue grafts with MRI. Finally, a 3D-contouring procedure developed to facilitate graft delineation and geometrical conformity assessment is applied on an inverted template alginate pore network. This proof-of-concept establishes the possibility to reveal precisely engineered hydrogel structures using this USPIONs ink high-visibility approach

Life After AREDS 2: What Should We Recommend to Patients With or at Risk of AMD?

Purpose: To establish a consensus on clinical recommendation of oral supplementation for patients with or at risk of developing age-related macular degeneration (AmD), from the perspective of the Age-Related eye Disease Study 2 (AReDS 2) and other studies. Methods:&nbsp;Panel discussion based on a literature review of pertinent articles related to the prevention of AmD with oral supplementation. Results:&nbsp;on the basis of the findings, patients must first be encouraged to modify their diet and to eliminate modifiable risk factors before being recommended any type of oral supplementation. Then, recommendations must be customized on the basis of a patient’s individual risk profile (i.e., age, gender, heredity, etc.) and severity of disease (i.e., category 1 to 4). essential fatty acids (omega-3s) and vitamins may play a role, in a given clinical population, to prevent the occurrence or the progression of AmD disease. However, there is no single formula that can be applied to all patients with or at risk of AmD. Conclusions:&nbsp;This group concluded that the full body of literature must be taken into consideration in order to justify clinical recommendations for patients. A single study such as AReDS 2 cannot, by itself, guide clinical practice. In all cases, recommendations must be individualized and patients should be monitored regularly

High sensitivity detection of nanoparticles permeation through polymer membranes: A physico-chemical and nuclear imaging measurement approach

Diffusion cells are devices made of donor and acceptor compartments (DC and AC), separated by a membrane. They are widely used in pharmaceutical, cosmetic, toxicology, and protective equipment tests (e.g., gloves) to measure the kinetics of permeants (molecules and nanoparticles) across biological membranes as the skin. However, rarely is the concentration of permeants in the AC measured in continuous or in real-time, and this limitation leads to significant discrepancies in the calculations of kinetic parameters that define the permeation mechanisms. In this study, a diffusion cell compatible with positron emission tomography was used to measure the permeation kinetics of nanoparticles across glove membranes. The technology allows for the measurement of nanoparticle concentration in real-time in the two compartments (DC and AC) and at a detection sensitivity several orders of magnitude higher compared with conventional spectroscopies, thus allowing a much more precise extraction of kinetic parameters. Ultra-small (<10 nm) gold nanoparticles were used as a model nanoparticle contaminant. They were radiolabeled, and their diffusion kinetics was measured in continuous through latex and nitrile polymer membranes. Permeation profiles were recorded at sub-nanomolar sensitivity and in real-time, thus allowing the high precision extraction of kinetic permeation parameters. The technology, methodology, and data extraction process developed in this work could be applied to measure in real-time the kinetics of diffusion of a whole range of potentially toxic molecules and nanoparticles across polymer membranes, including glove membranes

Enjeux théoriques et pratiques du développement régional : 30 Ans de recherche au GRIR

Le trentième anniversaire du GRIR a été souligné au printemps 2013 par un colloque regroupant plusieurs chercheurs dans le domaine du développement local et régional. Cet ouvrage est le produit de leurs réflexions tant sur le plan théorique que pratique. Ce livre est articulé autour de trois axes : 1) la présentation des divers courants en développement régional, 2) des réflexions sur le passé et le présent des Premières Nations et 3) la présentation de cas concrets sur la prise en main du développement par les différents acteurs du territoire. Cet ouvrage est un outil permettant de constater le travail accompli en développement local et régional et de dégager des pistes de réflexion sur les avenues possibles de développement

The measurement of ancestral roots with genealogical data

This study presents a new method to measure the depth of ancestral roots in a population. This method sheds light on the migratory movements which led to present-day population distribution across space. The method was applied to a dataset of 5,100 ascending genealogies from seventeen regions of the province of Quebec (Canada). Dates of marriage of the earliest ancestors married in the same region as their descendants were used to measure the age of individual ancestral roots. The average regional ages vary between 16 and 157 years, while some individual roots reach as far back as 300 years in the same region. The proposed method can be useful for assessing how deeply rooted a contemporary population is at a local, regional or other geographical level