University of Saskatchewan

About: University of Saskatchewan is a education organization based out in Saskatoon, Saskatchewan, Canada. It is known for research contribution in the topics: Population & Health care. The organization has 25021 authors who have published 52579 publications receiving 1483049 citations. The organization is also known as: USask.

Hierarchical habitat selection by woodland caribou: its relationship to limiting factors

Abstract: Habitat selection is a hierarchical process that may yield various patterns depending on the scales of investigation. We employed satellite radio-telemetry to examine patterns of habitat selection by female woodland caribou in central Saskatchewan at both coarse (seasonal range) and fine (daily area) scales. At each scale, we converted spatial data describing compositions of available and used habitat to standardised resource selection indices and examined them with multivariate analyses of variance. Seasonal ranges generally showed preferential inclusion of peatlands and black spruce dominated stands relative to recently disturbed stands and early seral stage forests. In all populations, caribou preferred peatlands and black spruce forests to all other habitat types at the daily area scale. In general, these patterns may reveal the effective avoidance of wolves, the primary factor limiting caribou throughout the boreal forest. In three populations where seasonal ranges showed the selective inclusion of either young jack pine stands or clearcuts along with peatlands and black spruce forests, we found a relative avoidance of the clearcuts and young jack pine stands at the daily area scale. As all caribou populations in the area are thought to be relics of a once more continuous distribution, the seasonal range selection by animals in disturbed areas may better describe historic rather than current habitat selection. We found inter-annual variation in selection at the coarser spatial scale in one population, and inter-seasonal variation in selection at the finer spatial scale in three populations, indicating that the relative grains of the spatial and temporal scales coincide. We were better able to explain the seasonal variations in finer scale selection by considering available forage, a factor less likely than predation to limit woodland caribou populations. The data agree with the theory that the spatial and temporal hierarchy of habitat selection reflects the hierarchy of factors potentially limiting individual fitness.

Bcl10 activates the NF-κB pathway through ubiquitination of NEMO

Abstract: The NF-κB family of transcription factors is activated in response to many stimuli, including pro-inflammatory cytokines, environmental stresses and, in the case of B and T lymphocytes, by antigenic stimulation1,2. Bcl10 is essential for NF-κB activation by T- and B-cell receptors. T and B lymphocytes from Bcl10-deficient mice fail to activate NF-κB in response to antigen-receptor stimulation and, as a consequence, are unable to proliferate3. Bcl10 overexpression is sufficient to activate NF-κB, a process that requires the NF-κB essential modulator NEMO (also known as IKK-γ), which is the regulatory subunit of the IκB kinase complex4. However, the cellular mechanism by which Bcl10 activates the NF-κB pathway remains unclear. Here we show that Bcl10 targets NEMO for lysine-63-linked ubiquitination. Notably, a mutant form of NEMO that cannot be ubiquitinated inhibited Bcl10-induced NF-κB activation. Paracaspase and a ubiquitin-conjugating enzyme (UBC13) were both required for Bcl10-induced NEMO ubiquitination and subsequent NF-κB activation. Furthermore, short interfering RNAs that reduced the expression of paracaspase and UBC13 abrogated the effects of Bcl10. Thus, the adaptor protein Bcl10 promotes activation of NF-κB transcription factors through paracaspase- and UBC13-dependent ubiquitination of NEMO.

Mechanisms of action of adjuvants.

Abstract: Adjuvants are used in many vaccines, but their mechanisms of action are not fully understood. Studies from the past decade on adjuvant mechanisms are slowly revealing the secrets of adjuvant activity. In this review, we have summarized the recent progress in our understanding of the mechanisms of action of adjuvants. Adjuvants may act by a combination of various mechanisms including formation of depot, induction of cytokines and chemokines, recruitment of immune cells, enhancement of antigen uptake and presentation, and promoting antigen transport to draining lymph nodes. It appears that adjuvants activate innate immune responses to create a local immuno-competent environment at the injection site. Depending on the type of innate responses activated, adjuvants can alter the quality and quantity of adaptive immune responses. Understanding the mechanisms of action of adjuvants will provide critical information on how innate immunity influences the development of adaptive immunity, help in rational design of vaccines against various diseases, and can inform on adjuvant safety.

Production, formulation and application of the entomopathogenic fungus Beauveria bassiana for insect control: current status.

Abstract: This review summarizes the progress and achievements made in the last decade in mass production formulation and application technology of the entomopathogenic fungus Beauveria bassiana. Reports published on relevant research from Belgium, Canada, China, Cuba, Czechoslovakia (former), France, Germany, Great Britain, Philippines, Poland, Switzerland, USA and USSR (former) regarding this topic have been covered. Much of the non‐English language literature, particularly that from Eastern European and Chinese sources, has not been translated and is inaccessible to most English or other western language readers. We have done this translation and through this review provide technological details about mass production of B. bassiana in China. Various aspects of B. bassiana growth, substrate use, production of mycelia, conidiospore and blastospores, process technologies associated with separation, drying and milling, formulation, storage and ‘shelf‐life’, and field efficacy are reviewed. Data are presented on: a m...