Sebastian Ruzycki, Guitar

Diferncias Sobre Guardame Las Vaca ; Canción del Emperador / Luys De Narváez; Lute Suite, BWV 997 / Johann Sebastian Bach; Variations on a theme by Mozart, Opus 9 / Fernando Sor; Étude No. 7; Étude No. 11 / Heitor Villa-Lobos; Junto al Generalife; En los Trigales / Joaquin Rodrig

Deciphering mechanisms governing the development of the rod epigenome

Precisely coordinated expression of distinct sets of genes is essential for cellular development and function, especially in complex multicellular organisms. This regulation is achieved by the action of transcription factors (TF), proteins that bind specific genomic locations and alter the activity state and packaging of the DNA to promote or repress gene expression. However, while tremendous effort has defined networks of transcription factors that work together to drive specific phenotypes, little is known about their differential activity at the hundreds or thousands of sites where they bind. There are also many questions regarding the basic principles of the packaging of DNA within the nucleus, its influence on gene expression, and how transcription factors regulate this process. To address these questions, I have investigated gene regulatory mechanisms that control the development of rod and cone photoreceptors. Photoreceptors are the neurons of the retina responsible for the initial conversion of a visual stimulus into an electrical signal. Photoreceptors are a complex, accessible, and highly disease relevant neuronal cell population, the lessons from which are relevant for many other cell types across the body. A primary TF in photoreceptor development is CRX. This TF when mutated in humans can cause severe vision loss, and its deletion in mice leads to a severe condition with no functional photoreceptors. First, I determined the functional consequences of human disease-causing variants when modelled in mice. I functionally classified a new model as causing a previously un-determined dominant disease, and discovered that all CRX diseases are the result of graded differences in gene expression of the same core set of genes. Second, I examined the dependency of all genomic binding sites on CRX activity and identified a core set of regulatory elements that require CRX for activation of the target genes. Third, I interrogated the broader organization of the rod photoreceptor epigenome and demonstrated that the rod packages its DNA according to epigenomic activity state. Perturbations to this state can override this organization, resulting in functional consequences on gene expression beyond the local sequence. In summary, my in-depth investigation has uncovered new insights into the molecular mechanisms controlling development and maintenance of the rod epigenome and its organization in the nucleus. This new knowledge will provide 1) a new understanding of where and how mutations in a key photoreceptor TF cause gene mis-regulation, and 2) guidance for future human genetic studies to identify new disease-causing mutations affecting photoreceptor integrity, not only in the protein coding sequences but also in specific non-coding regulatory regions

"Control Your Dreams", By Jayne I. Gackenbach and Jane Bosveld, New York: Harper and Row, 1989.

Over the past ten to fifteen years a staggering number of popular books have been written about dreams. Despite this fact --or perhaps because of it --new titles continue to sell well. People seem especially interested in a phenomenon of which they have first hand experience. They are curious about what goes on "in the mind" or "in the brain" when we dream

Salmonine Consumption and Competition for Endemic Prey Fishes in Bear Lake, Utah-Idaho

Two principal sport fish—the indigenous Bonneville cutthroat trout Oncorhynchus clarki utah and the introduced lake trout Salvelinus namaycush—are the dominant piscivores in Bear Lake, a 282-km^2 oligotrophic system. These piscivores rely predominantly on four endemic prey fish species that make up a major portion of the unique Bear Lake fish assemblage. We estimated the annual biomass of pelagic and benthic prey fish by using hydroacoustic and trawling techniques. We also estimated the lakewide abundance of piscivores with a multiple mark–recapture survey and used a bioenergetics model to compare the population-level consumption of prey fish with prey fish production. Prey fish biomass declined to a minimum during 1991 and 1992 but subsequently recovered to reach maximum levels during 1994 and 1995. The proportion of maximum ration estimates from model simulations indicated that the piscivores were consuming well below maximum rations during a period when predation exceeded prey fish production, thereby providing the potential for a predator–prey imbalance. Predation impacts by lake trout cohorts were prolonged because of high survivorship and long life expectancy. Although cutthroat trout outnumbered lake trout, the larger, more piscivorous size-classes of cutthroat trout accounted for only 12.5% of their population. This information, combined with overlapping diets and declining condition factors at increased piscivore biomass, also indicates that lake trout may be competing with cutthroat trout during periods of low prey fish resources. Lake trout predation on juvenile cutthroat trout, combined with competition with other age-classes, also contributes to the poor survival of cutthroat trout. Although prey fish abundance appears to be largely influenced by bottom-up factors related to water elevation, lake trout exert a decoupled predatory threat to the endemic prey fish populations and have the potential to suppress endemic fishes during unpredictable periods of poor prey fish production

Les moments équité, diversité, inclusion pour améliorer les connaissances des médecins leaders en matière d’équité, diversité, inclusion

Implication Statement Previous research in our department on equity-deserving groups revealed that physician leaders could improve their understanding of barriers faced by physicians from these groups. We developed EDI Moments, a brief, recurring educational intervention, to raise the EDI literacy of physician leaders in our Department of Medicine. In addition to being considered a good use of time by attendees, EDI Moments have led to new processes and policies to improve EDI in our department. Teams that implement EDI Moments should leverage local EDI expertise and select topics suited for their audience’s baseline knowledge.Énoncé des implications de la recherche Des recherches antérieures menées dans notre département sur les groupes visés par l’équité ont révélé que les médecins leaders avaient une compréhension insuffisante des obstacles auxquels sont confrontés les médecins appartenant à ces groupes. Nous avons créé les Moments EDI, une brève intervention éducative périodique visant à améliorer les connaissances des médecins leaders de notre département en matière d’EDI. Ceux qui y ont assisté estiment que cela a été un bon investissement de leur temps, mais les Moments EDI ont avant tout déclenché l’élaboration de processus et de politiques pour renforcer l’EDI dans le département. Les équipes qui organisent les Moments EDI devraient tirer parti de l’expertise locale en matière d’EDI et choisir des sujets adaptés aux connaissances de base de leur public

Ontogenetic Habitat Shift of Juvenile Bear Lake Sculpin (Cottus extensus)

Bear Lake sculpin (Cottus extensus) exhibited an ontogenetic habitat shift during their first year of life. Soon after hatching in the littoral zone, the fry swam to the surface where they dispersed throughout the lake. Most juveniles that initially settled in the profundal zone returned to the littoral zone during their first summer. Patterns in the daily growth increments of otoliths confirmed the history of habitat residence and the individual size at the habitat switch. We used this habitat shift to test a μ/g model incorporating a growth rate-mortality risk trade-off. A trade-off occurred in the littoral zone because both growth rate and mortality risk were greater in this habitat. Given initial profundal residence, the directed movement of juveniles to the more profitable littoral zone was consistent with model predictions. Contrary to model predictions, juvenile sculpin initially occupied both habitats and switched habitats at a wide range of sizes. lack of a discrete switch size may have resulted, in part, from the lack of a strong trade-off or from an inability of fish to respond facultatively to environmental variables at the large spatial scale of this system

Essential functions of MLL1 and MLL2 in retinal development and cone cell maintenance

MLL1 (KMT2A) and MLL2 (KMT2B) are homologous members of the mixed-lineage leukemia (MLL) family of histone methyltransferases involved in epigenomic transcriptional regulation. Their sequence variants have been associated with neurological and psychological disorders, but little is known about their roles and mechanism of action in CNS development. Using mouse retina as a model, we previously reported MLL1\u27s role in retinal neurogenesis and horizontal cell maintenance. Here we determine roles of MLL2 and MLL1/MLL2 together in retinal development using conditional knockout (CKO) mice. Deletin

The Canada-Guyana medical education partnership: using videoconferencing to supplement post-graduate medical education among internal medicine trainees

Background: A Guyana-based, internal medicine (IM) post-graduate medical education program was established in 2013. However, lack of formal teaching sessions are barriers to the program’s success.Objective: To describe the partnership between the University of Calgary and the University of Guyana’s internal medicine residency programs (IMRP). This partnership was created to support the Guyana’s IM academic half-day and is characterized by mutually beneficial, resident-led videoconference teaching sessions.Methods: Calgary medical residents volunteered to create and present weekly teaching presentations to Guyanese residents via videoconference. Questionnaires were completed by Guyanese residents and provided to Calgary residents as feedback on their teaching and presentation skills. A similar survey was completed by Calgary residents.Lessons learned: Twenty-four videoconference teaching sessions were conducted over eight months with a total of 191 and 16 surveys completed by Guyana and Calgary residents, respectively. Over 92% of both Guyana and Calgary residents agreed that the sessions enhanced their learning and over 93% reported increased interest in becoming more involved in international collaborations. 88% of Calgary residents felt the sessions improved their teaching skills.Conclusion: The formation of a resident-led, videoconference teaching series is a mutually beneficial partnership for Canadian and Guyanese medical residents and fosters international collaboration in medical education.