Response to somatic cell count-based selection for mastitis resistance in a divergent selection experiment in sheep

A divergent selection experiment in sheep was implemented to study the consequences of log-transformed somatic cell score (SCS)-based selection on resistance to natural intramammary infections. Using dams and progeny-tested rams selected for extreme breeding values for SCS, we created 2 groups of ewes with a strong divergence in SCS of approximately 3 genetic standard deviations. A survey of 84 first-lactation ewes of both the High and Low SCS lines indicated favorable responses to SCS-based selection on resistance to both clinical and subclinical mastitis. All clinical cases (n = 5) occurred in the High SCS line. Additionally, the frequency of chronic clinical mastitis,as detected by the presence of parenchymal abscesses, was much greater in the High SCS line (n = 21) than in the Low SCS line (n = 1). According to monthly milk bacterio-logical examinations of udder halves, the prevalence of infection was significantly greater (odds ratio = 3.1) in the High SCS line than in the Low SCS line, with predicted probabilities of 37 and 16%, respectively. The most frequently isolated bacteria responsible for mastitis were staphylococci: Staphylococcus auricularis(42.6% of positive samples), Staphylococcus simulans, Staphylococcus haemoliticus, Staphylococcus xylosus, Staphylococcus chromogenes, Staphylococcus lentus, Staphylococcus warneri, and Staphylococcus aureus. The incidence of positive bacteriology was greater in the High SCS line (39%) than in the Low SCS line (12%)at lambing, indicating that High SCS line ewes were especially susceptible to postpartum subclinical mastitis. Negativation of bacteriological results from one sampling time point to the next was markedly different between lines after weaning (e.g., 41 and 84% in the High and Low SCS lines, respectively). This result was consistent with differences in the duration of infection, which was much greater in the High SCS line compared with the Low SCS line. Finally, ewes from the High SCS line consistently had greater SCS in positive milk samples than did ewes from the Low SCS line (+2.04 SCS, on average), with an especially large difference between lines during the suckling period (+3.42 SCS). Altogether, the preliminary results suggest that the better resistance of Low SCS line ewes, compared with High SCS line ewes, was principally characterized by a better ability to limit infections during the peripartum period, to eliminate infections during lactation, and quantitatively to limit the inflammation process and its clinical consequences

La fonte cornéenne post-kératoprothèse de Boston type I : épidémiologie, pathophysiologie et approche novatrice pour sa prévention

La fonte cornéenne post-kératoprothèse de Boston (B-KPro) est une complication sévère pouvant nuire à la rétention de la prothèse et pouvant mener à la perte du globe oculaire. Quoique multifactoriel, le mécanisme final menant à une fonte cornénne est médiée par des métalloprotéinases matricielles (MMP). L’activité de ces enzymes peut être induite par des cytokines inflammatoires dont le facteur de nécrose tumorale alpha. Les objectifs de cette thèse sont de 1) relever les données épidémiologiques de la fonte cornéenne post-B-KPro, 2) de caractériser la teneur et l’activité des MMP, de la myeloperoxidase (MPO) et de l’inhibiteur tissulaire de la metalloproteinase 1 (TIMP-1) des larmes de patients ayant une B-KPro et de différencier ces profils selon le diagnostic sous-jacent et 3) de développer une goutte ophtalmique d’infliximab et d’évaluer ses caractéristiques in vitro. Une revue de la litérature et des cas de B-KPro implantés au CHUM a permis de déterminer les facteurs de risque de la fonte cornéenne, les plus importants étant l’apport nutritif au stroma cornéen et la présence d’inflammation. Le profil enzymatique a été déterminé à l’aide d’ELISA multiplex. L’élévation des MMP-8, MMP-9 et MPO des larmes est corrélée avec le type de pathologie cornéenne mais non pas avec la présence de fonte cliniquement significative. L’infliximab topique 10 mg/mL reste stérile, stable et non toxique pour l’épithélium de la surface oculaire. En conclusion, l’inflammation de la surface oculaire est un facteur de risque important de la fonte cornéenne et diverses stratégies thérapeutiques menant à l’inhibition des MMP devront être explorées dans le cadre d’études cliniques futures.Corneal melting after implantation of a Boston keratoprosthesis (B-KPro) is a severe sight- and globe-threatening complication. While multifactorial, the final mechanism leading to corneal melting is mediated by matrix metaloproteinases (MMP). The activity of these enzymes is induced by inflammatory cytokines, mostly tumor necrosis factor alpha. The objectives of this thesis is to 1) report the epidemiologic data surrounding post-B-KPro corneal melting, 2) caracterize the content and activity of MMP, myeloperoxidase (MPO) and tissue inhibitor of metalloproteinase 1 (TIMP-1) in the tears of patients with a B-KPro and to distinguish these enzymatic profiles in accordance to the underlying ocular diagnosis and 3) to develop an ophthalmic drop of infliximab and to evaluate its in vitro characteristics. A literature review and a review of all B-KPros implanted at the CHUM allowed identification of the risk factors of corneal melting, the most important being corneal stromal nutrition and the presence of inflammation. The enzymatic profile at the ocular surface was determined through bead-based multiplex ELISA. Significant elevations of MMP-8, MMP-9 and MPO in the tears of B-KPro eyes were correlated with the type of underlying corneal pathology but not with the presence of clinically significant corneal melting. Topical infliximab 10 mg/mL remained sterile, stable and non toxic to ocular surface epithelium when prepared and used in accordance with United States Pharmacopeia recommendations. In conclusion, ocular surface inflammation is an important risk factor for corneal melting with B-KPro and therapeutic strategies to inhibit MMP should be explored in future clinical studies

Difficultés parentales liées aux caractéristiques du haut potentiel intellectuel chez l’enfant : une étude exploratoire

La douance, ou haut potentiel intellectuel (HPI), a longtemps été associée à l’élitisme dans le milieu de l’éducation québécois (Massé, 2000). Cette position a mené à des choix de société ayant pour conséquences un retard important des connaissances et des services offerts aux enfants HPI et à leurs parents (Bélanger, 2017; Brault-Labbé et al., sous presse). Dans la documentation, les recherches empiriques portant sur le vécu des parents d’enfants HPI sont rares et celles réalisées jusqu’à présent offrent des résultats qui ne sont pas généralisables au vécu des parents québécois, en raison du contexte sociopolitique particulier dans lequel ceux-ci évoluent (Clelland, 2009; Freeman, 2005). En effet, alors que plusieurs caractéristiques associées au HPI sont vécues difficilement par les parents (Clelland, 2009), une seule étude s’est intéressée directement au vécu parental lié à de telles caractéristiques et elle ne couvre que deux particularités ayant été associées au HPI (hypersensibilité et intensité manifestée par l’enfant) (Guthrie, 2019). Le présent mémoire tente de pallier cette lacune à l’aide d’une étude exploratoire et descriptive à devis mixte, laquelle s’inscrit dans le cadre d’une étude plus large qui avait pour but de documenter divers aspects du vécu des parents d’enfants HPI au Québec. L’objectif général du mémoire est de mieux comprendre les difficultés des parents concernant les caractéristiques que ceux-ci associent au HPI de leurs enfants. Deux objectifs spécifiques sont poursuivis. Le premier vise, au moyen de statistiques descriptives (volet quantitatif), à évaluer l’intensité des difficultés ressenties par les parents concernant des caractéristiques fréquemment associées au HPI, afin de dégager celles qui semblent être vécues plus difficilement. Le deuxième vise, au moyen d’une analyse thématique (volet qualitatif), à décrire la nature des difficultés rencontrées. Les données ont été recueillies auprès de 260 parents dans le cadre de l’étude source, au moyen d’un questionnaire en ligne conçu spécifiquement aux fins de cette recherche. Les résultats du volet quantitatif indiquent qu’en moyenne les parents rencontrent des difficultés d’intensité variable en lien avec de nombreuses particularités de leurs enfants HPI (niveau de difficulté allant de légèrement difficile à difficile). Ils indiquent aussi que les particularités vécues le plus difficilement par les parents sont les particularités émotionnelles de leurs enfants, alors que les particularités cognitives sont celles vécues le moins difficilement. Les résultats du volet qualitatif permettent de décrire de nombreuses caractéristiques des enfants HPI vécues difficilement par les parents (axe 1), de détailler le vécu subjectif des parents au regard de ces caractéristiques (axe 2) et d’exposer des stratégies qu'ils mettent en place pour composer avec les difficultés qu’ils vivent (axe 3). Les résultats sont discutés en termes de piste de recherches futures, de retombées possibles pour le développement de ressources plus adaptées aux besoins des parents d’enfants HPI et de retombées possibles pour une sensibilisation accrue de la société québécoise aux enjeux que vit cette population

La fonte cornéenne post-kératoprothèse de Boston type I : épidémiologie, pathophysiologie et approche novatrice pour sa prévention

La fonte cornéenne post-kératoprothèse de Boston (B-KPro) est une complication sévère pouvant nuire à la rétention de la prothèse et pouvant mener à la perte du globe oculaire. Quoique multifactoriel, le mécanisme final menant à une fonte cornénne est médiée par des métalloprotéinases matricielles (MMP). L’activité de ces enzymes peut être induite par des cytokines inflammatoires dont le facteur de nécrose tumorale alpha. Les objectifs de cette thèse sont de 1) relever les données épidémiologiques de la fonte cornéenne post-B-KPro, 2) de caractériser la teneur et l’activité des MMP, de la myeloperoxidase (MPO) et de l’inhibiteur tissulaire de la metalloproteinase 1 (TIMP-1) des larmes de patients ayant une B-KPro et de différencier ces profils selon le diagnostic sous-jacent et 3) de développer une goutte ophtalmique d’infliximab et d’évaluer ses caractéristiques in vitro. Une revue de la litérature et des cas de B-KPro implantés au CHUM a permis de déterminer les facteurs de risque de la fonte cornéenne, les plus importants étant l’apport nutritif au stroma cornéen et la présence d’inflammation. Le profil enzymatique a été déterminé à l’aide d’ELISA multiplex. L’élévation des MMP-8, MMP-9 et MPO des larmes est corrélée avec le type de pathologie cornéenne mais non pas avec la présence de fonte cliniquement significative. L’infliximab topique 10 mg/mL reste stérile, stable et non toxique pour l’épithélium de la surface oculaire. En conclusion, l’inflammation de la surface oculaire est un facteur de risque important de la fonte cornéenne et diverses stratégies thérapeutiques menant à l’inhibition des MMP devront être explorées dans le cadre d’études cliniques futures.Corneal melting after implantation of a Boston keratoprosthesis (B-KPro) is a severe sight- and globe-threatening complication. While multifactorial, the final mechanism leading to corneal melting is mediated by matrix metaloproteinases (MMP). The activity of these enzymes is induced by inflammatory cytokines, mostly tumor necrosis factor alpha. The objectives of this thesis is to 1) report the epidemiologic data surrounding post-B-KPro corneal melting, 2) caracterize the content and activity of MMP, myeloperoxidase (MPO) and tissue inhibitor of metalloproteinase 1 (TIMP-1) in the tears of patients with a B-KPro and to distinguish these enzymatic profiles in accordance to the underlying ocular diagnosis and 3) to develop an ophthalmic drop of infliximab and to evaluate its in vitro characteristics. A literature review and a review of all B-KPros implanted at the CHUM allowed identification of the risk factors of corneal melting, the most important being corneal stromal nutrition and the presence of inflammation. The enzymatic profile at the ocular surface was determined through bead-based multiplex ELISA. Significant elevations of MMP-8, MMP-9 and MPO in the tears of B-KPro eyes were correlated with the type of underlying corneal pathology but not with the presence of clinically significant corneal melting. Topical infliximab 10 mg/mL remained sterile, stable and non toxic to ocular surface epithelium when prepared and used in accordance with United States Pharmacopeia recommendations. In conclusion, ocular surface inflammation is an important risk factor for corneal melting with B-KPro and therapeutic strategies to inhibit MMP should be explored in future clinical studies

How to make the IS discipline relevant to non-IS stakeholders?

A recent survey of IS academic leaders revealed that a prominent concern of many IS academic leaders relates to making the IS discipline relevant to non-IS stakeholders within their university. Some examples of this challenge include: • MIS/IS is not well understood as a flagship area to strategically develop and improve by the university administrators; • Understanding of IS by those outside of the discipline and how to market the IS discipline to a larger audience, including students; • Managing the collaboration with other departments on emerging technologies initiatives (such as analytics, AI) and programs; • Rewarding cross-disciplinary research and navigating tenure when publishing in other fields; • Student and faculty recruitment and retention. This professional development symposium (PDS) is meant to leverage the vast experience of Senior Scholars who have dealt with this issue and to hear their guidance and recommendations as to how to address this. This PDS is sponsored by the AIS College of Academic Leadership and the College of Senior Scholars

Ultrasonication of spray- and freeze-dried cellulose nanocrystals in water

The structural and rheological properties of aqueous suspensions of spray-dried cellulose nanocrystals (CNCs) were investigated and compared to those of freeze-dried. The cellulose nanocrystals were obtained from sulfuric acid hydrolysis of wood pulp. Ultrasonication was used to disperse cellulose nanocrystals in Milli-Q water and the power applied during ultrasonication was shown to be the controlling parameter for their dispersion, more than total energy. Dynamic light scattering measurements showed a decrease of the average hydrodynamic diameter down to the same limiting value, i.e. ∼75 nm, for both spray and freeze-dried cellulose nanocrystals. Since the same maximum dispersion state was reached for both CNC types, it indicated that the spray drying process did not limit dispersion, provided that sufficient ultrasonication was provided. Moreover, no desulfation occurred during ultrasonication at ambient temperature. Strong ultrasonication also caused a decrease of intrinsic viscosity, along with an increase in maximum packing concentration. These properties were correlated to agglomerates break-up, which released both ions and water in suspension. The ionic strength increase may lead to a thinner electrostatic double layer surrounding the cellulose nanocrystals, reducing their apparent concentration

The structural amphiphilicity of cellulose nanocrystals characterized from their cohesion parameters

Cellulose nanocrystals (CNCs), usually considered as isotropically polar nanoparticles, are sheet-like crystalline assemblies of cellulose chains. Here, we link the anisotropy of the CNC structure to an amphiphilic behavior in suspension. The Hansen solubility parameters (HSP: δD; δP; δH) of woodbased H2SO4-hydrolyzed CNCs were measured from sedimentation tests in a wide set of 59 solvents and binary mixtures. Two sets of cohesion parameters corresponding to a polar surface (18.1; 20.4; 15.3) ± (0.5; 0.5; 0.4) MPa1/2 and to a mildly non-polar one (17.4; 4.8; 6.5) ± (0.3; 0.5; 0.6) MPa1/2 were determined, with respective solubility radii of 7.8 and 2.1MPa1/2. The polar sphere is thought to correspond to the (110)&(110) surfaces of cellulose Iβ nanocrystals, while the smaller non-polar sphere is coherent with the exposure of (200) surfaces. The HSP graph provides new insights on the amphiphilic nature of CNCs and a mapping of their chemical affnity for solvents and polymer matrices

fMRI assessment of upper extremity related brain activation with an MRI-compatible manipulandum

Purpose: Longitudinal studies to evaluate the effect of rehabilitative therapies require an objective, reproducible and quantitative means for testing function in vivo. An fMRI assessment tool for upper extremity related brain activation using an MRI-compatible manipulandum was developed and tested for use in neurorehabilitation research. Methods: Fifteen healthy, right-handed subjects participated in two fMRI sessions, which were three to four weeks apart. A block design paradigm, composed of three conditions of subject-passive movement, subject-active movement and rest, was employed for the fMRI recordings. During the rest condition, subjects simply held the device handle without applying any force or movement. The same type of auditory and visual instructions were given in all the three conditions, guiding the subjects to perform the motor tasks interactively with the MRI-compatible arm manipulandum. The tasks were controlled across the fMRI sessions. The subjects' brain activation was recorded by fMRI, and their behavioral performance was recorded by the manipulandum. The brain network activated by the subjects' interaction with the manipulandum was identified, and the reproducibility and reliability of the obtained activation were determined. Results: All subjects completed the trial protocol. Two subjects were excluded from analysis due to head motion artifacts. All passive movements were performed well. Four out of the total 780 active movements were missed by two subjects. Brain activation was found in the contralateral sensorimotor cortex, secondary somatosensory cortex and non-primary motor cortex as well as in subcortical areas in the thalamus, basal ganglia and the cerebellum. These activations were consistent across the two fMRI sessions. Conclusion: The MRI-compatible manipulandum elicited robust and reproducible brain activations in healthy subjects during the subject-active and subject-passive upper extremity motor tasks with a block design paradigm. This system is promising for many applications in neurorehabilitation research and may be useful for longitudinal studie

The apparent structural hydrophobicity of cellulose nanocrystals

The Teas graph of wood-based sulfuric acid-hydrolyzed cellulose nanocrystals (CNCs) was plotted based on sedimentation tests in a set of 25 common solvents. Comparisons with those of sucrose and dextran, taken as equivalents for cellobiose (cellulose repeating unit) and amorphous cellulose, respectively, highlighted the amphiphilic nature of CNCs. In the absence of any chemical arguments, the hydrophobic behavior displayed is thought to be caused by the exposition of (200) lattice planes at the CNC surface. This apparent structural hydrophobicity may be exploited to achieve the dispersion of CNCs in some mildly-non polar matrices such as poly(ethylene glycol) and poly(lactic acid). The Teas graph is a useful tool to predict the dispersibility potential of CNCs and to select a proper solvent for nanocomposite preparatio