Publications by authors named "Muirhead S"

The ectoparasitic mite Varroa destructor remains a great threat for the beekeeping industry, for example contributing to excessive winter colony loss in Canada. For decades, beekeepers have sequentially used the registered synthetic varroacides tau-fluvalinate, coumaphos, amitraz, and flumethrin, leading to the risk of resistance evolution in the mites. In addition to the widespread resistance to coumaphos and pyrethroids, a decline in amitraz efficacy has recently been reported in numerous beekeeping regions in Canada.

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The use of plant growth-promoting rhizobacteria presents a promising addition to conventional mineral fertilizer use and an alternative strategy for sustainable agricultural crop production. However, genotypic variations in the plant host may result in variability of the beneficial effects from these plant-microbe interactions. This study examined growth promotion effects of commercial vegetable crop cultivars of tomato, cucumber and broccoli following application with five rhizosphere bacteria.

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Lameness is an important veterinary and welfare concern for giraffes in human care. To date, there is limited information on the objective weight-bearing characteristics of the foot in giraffes, making evidence-based decisions for foot care and lameness treatment subjective. Eleven young-adult reticulated giraffes (; median age, 3.

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Introduction: In March 2020, a pandemic state was declared due to SARS-COV-2 (COVID-19). Patients with kidney disease, especially those on replacement therapies, proved more susceptible to severe infection. This rapid literature review aims to help understand how the pandemic impacted patient experience of kidney care.

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Background: Varroa mite, Varroa destructor, is a major threat for honey bee, Apis mellifera, colonies. Beekeepers have used synthetic Varroacides against Varroa mite for decades, but resistance to organophosphates, pyrethroids and formamidine has been reported in many locations worldwide. The goals of this study were to develop a reliable bioassay to assess efficacy and phenotypic resistance to commercial Varroacides.

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Nosema ceranae Fries, 1996, causes contagious fungal nosemosis disease in managed honey bees, Apis mellifera L. It is associated around the world with winter losses and colony collapse disorder. We used a laboratory in vivo screening assay to test curcumin, fenbendazole, nitrofurazone and ornidazole against N.

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Background: The Varroa mite (Varroa destructor) is an ectoparasite that can affect the health of honey bees (Apis mellifera) and contributes to the loss of colony productivity. The limited availability of Varroacides with different modes of action in Canada has resulted in the development of chemical resistance in mite populations. Therefore, an urgent need to evaluate new potential miticides that are safe for bees and exhibit high efficacy against Varroa exists.

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Varroa destructor Anderson and Trueman, is an ectoparasitic mite of honey bees, Apis mellifera L., that has been considered a major cause of colony losses. Synthetic miticides have been developed and registered to manage this ectoparasite, however, resistance to registered pyrethroid and organophosphate Varroacides have already been reported in Canada.

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The honey bee, Apis mellifera L., is the world's most important managed pollinator of agricultural crops, however, Varroa mite, Varroa destructor Anderson and Trueman, infestation has threatened honey bee survivorship. Low efficacy and development of Varroa mite resistance to currently used Varroacides has increased the demand for innovative, effective treatment tool options that exhibit high efficacy, while minimizing adverse effects on honey bee fitness.

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Purpose: To evaluate the IOP values obtained from normal canine eyes, by means of the TonoVet Plus (TVP) and TonoPen Avia (TPA), and compare them to an established tonometer, the TonoVet (TV).

Methods: Tonometry was performed bilaterally in 50 healthy dogs, age 1-11 years. The rebound tonometers (TV and TVP) were used first (in a random order), and then, one drop of tetracaine hydrochloride was applied to each eye, and approximately one minute later the IOP was estimated using the TPA.

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The survival rate for childhood cancer, including brain tumors, is increasing. As a result, long-term sequelae of chemotherapy and radiotherapy are also increasing. The purpose of this study was to determine the frequency of endocrine complications of therapy for brain tumors in pediatric patients.

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Objective: To investigate trends and geographic variation in diabetic ketoacidosis (DKA) hospitalization rates among children in Ontario from 1991 to 1999.

Research Design And Methods: Canadian Institute for Health Information (CIHI) data were used to identify 15,872 diabetes-related hospital admissions in children younger than 19 years in Ontario from 1991 to 1999. Of these, 5,008 admissions were because of DKA and 10,864 admissions were because of conditions other than DKA (non-DKA).

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Objective: To obtain objective information on the relationship between adult height (AH), glucocorticoid (GC) dose, and degree of hormonal suppression in a population of patients with 21-hydroxylase deficiency congenital adrenal hyperplasia (21-OHD CAH) to optimize treatment regimes.

Study Design: Multicenter retrospective chart review of patients with salt wasting 21-OHD CAH diagnosed in the first 6 months of life, and who had reached AH (n = 54). The data were compiled into a single database.

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Thyroid disease is a common paediatric disorder that affects up to 3.7% of school-aged children, and it usually presents with a goitre. By far, the most frequent cause of a goitre is autoimmune thyroid disease, although a benign colloid goitre is also a common cause.

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Activating somatic mutations in the thyrotropin (TSH) receptor have been identified as a cause of hyperfunctioning thyroid adenomas, and germline mutations have been found in familial nonautoimmune hyperthyroidism and sporadic congenital hyperthyroidism. All mutations reported to date have been located in the transmembrane domain. We now report an example of an activating mutation in the extracellular, TSH-binding domain, found in a male infant with congenital hyperthyroidism due to a toxic adenoma.

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Investigations of human autoimmune diseases have largely involved study of circulating T cells. The development of T-cell cloning technology has made possible the study of the small numbers of T cells found at sites of pathological involvement in autoimmune diseases. In this initial communication, the feasibility of in vitro propagation of synovial fluid T cells from patients with arthritis is demonstrated.

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The investigation of cell-mediated events in man has been largely limited to the study of the cells in the peripheral circulation. The study of T cells from localized anatomic compartments has been difficult due to the small numbers of cells usually obtainable from these sites. Investigation of such compartmentalized responses theoretically may yield information relating to both normal immunoregulation and autoimmune diseases--information that may not be obtainable through the investigation of the circulating cellular immune system.

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Human alpha 1-antitrypsin ( alpha-1-AT;Pi) production was analyzed in 11 primary mouse hepatoma-human lymphoid cell hybrids and in 14 secondary rat hepatoma-human fetal liver fibroblast hybrids. The presence of human alpha-1-AT was determined by Laurell immunoelectrophoresis of concentrated and isotopically labeled supernatant medium. Human alpha-1-AT production segregated in the mouse-human hybrids concordantly with human purine nucleoside phosphorylase and with chromosome 14.

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